The effect of electromagnetic field of different intensities on Pseudomonas aeruginosa (as gram-negative
bacteria) and Bacillus subtilis (as gram-positive bacteria) was investigated to find out the effective magnetic field strength that alters the running physiological processes of every microorganism. Equal volumes of P. aeruginosa and B. subtilis suspensions were exposed for one hour at their maximum rate of active growth to the electromagnetic field (2 - 10 mT, 50 Hz). The results indicated that no remarkable differences were found in the growth of exposed P. aeruginosa. Moreover, a remarkable inhibition in the growth of exposed relative to unexposed B. subtilis cells was achieved at (4 mT) as compared with other intensities which may indicate that this magnetic field induction had a great effect on the biological activity of the cells, so more investigations were made at this magnetic field induction. Remarkable changes in the growth characteristics could be easily detected as the absorbance decreased which indicate a decrease in the cells number and consequently an
inhibition case for the bacteria. Also, the antibiotic sensitivity test of B. subtilis cells indicated either inhibition or stimulation case for the bacteria depending on the drug mode of action
Control of metabolic activities of E.coli and S. aureus bacteria by Electric ...inventy
Low electric currents generated using conductive electrodes have been used to increase the efficacy of antibiotics against bacterial biofilms, a phenomenon termed “the bioelectric effect” that formed metal ions and free radicals which can inhibit the growth of planktonic Staphylococcus aureus (S.aureus) and Escherichia Coli (E.Coli) the effect is amplitude and frequency dependent, the aim of present study to define the parameters that are most effective against bacterial growth also to investigate the comparative study through inactivation of metabolic activities, growth rate, morphology, bacterial conductivity and antibiotic sensitivity between gram negative E.Coli and gram positive S.aureus bacteria by extremely low frequency electric field (ELF-EF). In this work, the frequency of electric impulses that interfere with the bioelectric signals generated during E.Coli and S.aureus cellular division is investigated in order to compare cell viability, number of colony forming units (CFU) and growth rate (optical density at 600nm) bacterial conductivity and antibiotic susceptibility. Also morphological cellular structure was investigated by transmission electron microscope (TEM). The results revealed that a highly significant inhibition effect occurred when S.aureus and E.Coli was exposed to resonance of 0.8, 0.5 Hz square amplitude modulated waves (QAMW) respectively for 2hours exposure .Moreover, exposed cells became more sensitive to the tested antibiotics compared to control. Significant ultra-structural changes occurred as observed by TEM which indicated morphological changes. It will be concluded that, the use of 0.8, 0.5 Hz QAMW in controlling the biological activity of S.aureus and E.coli respectively seems to be a new and promising medical activity.
James J. Collins
Howard Hughes Medical Institute
Dept of Biomedical Engineering & Center of Synthetic Biology
Boston University
Wyss Institute for Biologically Inspired Engineering
Harvard University
American Journal of Bioterrorism, Biosecurity and Biodefense is an international scholarly peer reviewed Open Access journal, aims to promote the research in all the related fields of Bioterrorism, Biosecurity and Biodefence.
American Journal of Bioterrorism, Biosecurity and Biodefense is a comprehensive Open Access peer reviewed scientific Journal that covers multidisciplinary fields. We provide limitless access towards accessing our literature hub with colossal range of articles. The journal aims to publish high quality varied article types such as Research, Review, Short Communications, Case Reports, Perspectives (Editorials), Clinical Images.
American Journal of Bioterrorism, Biosecurity and Biodefense support the scientific modernization and enrichment in Bioterrorism, Biosecurity and Biodefense research community by magnifying access to peer reviewed scientific literary works. Austin also brings universally peer reviewed member journals under one roof thereby promoting knowledge sharing, collaborative and promotion of multidisciplinary science.
Research topic was come from successful inactivation of some plant viruses by gamma irradiation like Citrus tristeza virus, Necrotic ring spot virus and Prune dwarf virus. Gamma irradiation has been also used to sterilize agricultural products in order to increase their conservation time or to reduce pathogen when being traded from a country to another. Gamma radiation is high-energy radiation emitted from certain radioactive isotopes as cobalt 60, these isotopes are potential sources of gamma radiation. Therefore, this research was conducted to find out the inactivation possibility of Hibiscus witches' broom (HibWB)-phytoplasma using gamma irradiation through tissue culture technique with clarify their effect on in vitro growth and survival rate.
Biotechnology has the potential to provide benefits like increased food production and life-saving medical treatments, but also raises safety, environmental, and ethical concerns. The document discusses the history and modern applications of biotechnology, including recombinant DNA techniques. It outlines both the promises of biotechnology in areas like agriculture, medicine, and the environment, as well as concerns about risks like developing antibiotic resistance or potential human abuse. Different countries have varying approaches and regulations regarding biotechnology.
This study investigated the effectiveness of pulsed UV (PUV) light irradiation in damaging Bacillus cereus and Bacillus megaterium, two bacteria relevant to food safety issues. PUV treatment was found to inflict four types of cellular damage that prevented DNA replication. Total reduction of both bacteria was seen at 120P and 160P of PUV treatment. Bacillus megaterium was more sensitive, experiencing total reduction at 80P as well. Increased concentrations of leaked intracellular proteins also demonstrated the damaging effects of PUV. However, protein leakage did not correlate to reductions in viable bacterial counts. Further research is needed to determine the relationship between protein damage and DNA damage from PUV and its effects on pathogenic toxins produced by these bacteria
Control of metabolic activities of E.coli and S. aureus bacteria by Electric ...inventy
Low electric currents generated using conductive electrodes have been used to increase the efficacy of antibiotics against bacterial biofilms, a phenomenon termed “the bioelectric effect” that formed metal ions and free radicals which can inhibit the growth of planktonic Staphylococcus aureus (S.aureus) and Escherichia Coli (E.Coli) the effect is amplitude and frequency dependent, the aim of present study to define the parameters that are most effective against bacterial growth also to investigate the comparative study through inactivation of metabolic activities, growth rate, morphology, bacterial conductivity and antibiotic sensitivity between gram negative E.Coli and gram positive S.aureus bacteria by extremely low frequency electric field (ELF-EF). In this work, the frequency of electric impulses that interfere with the bioelectric signals generated during E.Coli and S.aureus cellular division is investigated in order to compare cell viability, number of colony forming units (CFU) and growth rate (optical density at 600nm) bacterial conductivity and antibiotic susceptibility. Also morphological cellular structure was investigated by transmission electron microscope (TEM). The results revealed that a highly significant inhibition effect occurred when S.aureus and E.Coli was exposed to resonance of 0.8, 0.5 Hz square amplitude modulated waves (QAMW) respectively for 2hours exposure .Moreover, exposed cells became more sensitive to the tested antibiotics compared to control. Significant ultra-structural changes occurred as observed by TEM which indicated morphological changes. It will be concluded that, the use of 0.8, 0.5 Hz QAMW in controlling the biological activity of S.aureus and E.coli respectively seems to be a new and promising medical activity.
James J. Collins
Howard Hughes Medical Institute
Dept of Biomedical Engineering & Center of Synthetic Biology
Boston University
Wyss Institute for Biologically Inspired Engineering
Harvard University
American Journal of Bioterrorism, Biosecurity and Biodefense is an international scholarly peer reviewed Open Access journal, aims to promote the research in all the related fields of Bioterrorism, Biosecurity and Biodefence.
American Journal of Bioterrorism, Biosecurity and Biodefense is a comprehensive Open Access peer reviewed scientific Journal that covers multidisciplinary fields. We provide limitless access towards accessing our literature hub with colossal range of articles. The journal aims to publish high quality varied article types such as Research, Review, Short Communications, Case Reports, Perspectives (Editorials), Clinical Images.
American Journal of Bioterrorism, Biosecurity and Biodefense support the scientific modernization and enrichment in Bioterrorism, Biosecurity and Biodefense research community by magnifying access to peer reviewed scientific literary works. Austin also brings universally peer reviewed member journals under one roof thereby promoting knowledge sharing, collaborative and promotion of multidisciplinary science.
Research topic was come from successful inactivation of some plant viruses by gamma irradiation like Citrus tristeza virus, Necrotic ring spot virus and Prune dwarf virus. Gamma irradiation has been also used to sterilize agricultural products in order to increase their conservation time or to reduce pathogen when being traded from a country to another. Gamma radiation is high-energy radiation emitted from certain radioactive isotopes as cobalt 60, these isotopes are potential sources of gamma radiation. Therefore, this research was conducted to find out the inactivation possibility of Hibiscus witches' broom (HibWB)-phytoplasma using gamma irradiation through tissue culture technique with clarify their effect on in vitro growth and survival rate.
Biotechnology has the potential to provide benefits like increased food production and life-saving medical treatments, but also raises safety, environmental, and ethical concerns. The document discusses the history and modern applications of biotechnology, including recombinant DNA techniques. It outlines both the promises of biotechnology in areas like agriculture, medicine, and the environment, as well as concerns about risks like developing antibiotic resistance or potential human abuse. Different countries have varying approaches and regulations regarding biotechnology.
This study investigated the effectiveness of pulsed UV (PUV) light irradiation in damaging Bacillus cereus and Bacillus megaterium, two bacteria relevant to food safety issues. PUV treatment was found to inflict four types of cellular damage that prevented DNA replication. Total reduction of both bacteria was seen at 120P and 160P of PUV treatment. Bacillus megaterium was more sensitive, experiencing total reduction at 80P as well. Increased concentrations of leaked intracellular proteins also demonstrated the damaging effects of PUV. However, protein leakage did not correlate to reductions in viable bacterial counts. Further research is needed to determine the relationship between protein damage and DNA damage from PUV and its effects on pathogenic toxins produced by these bacteria
The document discusses a lecture on biotechnology given by Dr. Srinivasreddy Patil. It covers topics like the introduction and tools of genetic engineering, including vectors, enzymes, and host cells. Recombinant DNA technology and its applications are explained, using the example of insulin synthesis. Other topics covered include DNA fingerprinting, gene therapy, the human genome project, and monoclonal antibodies. The document also addresses the hazards and safeguards of genetic engineering.
Biotechnology uses genes from different organisms to modify biological functions and create products to benefit society. It has applications in gene therapy, cancer treatment, vaccines, and more. Techniques include adding genes to crops to increase vitamin levels or tolerance to environmental stresses. DNA is delivered using organisms like Agrobacterium. Medical biotechnology aims to prolong life through monoclonal antibodies, bioprocessing insulin from bacteria, stem cell therapies, and tissue engineering to replace damaged tissues.
This document discusses biotechnology and genetic engineering. It provides examples of how biotechnology is used in forensics, agriculture, and genetic engineering. Genetic engineering involves transferring genes between organisms, such as placing human genes in bacteria. The document also discusses applications of genetic engineering like creating pest-resistant and herbicide-resistant crops through biotechnology techniques.
This document presents information on quorum sensing in archaea. It defines quorum sensing as a mechanism by which microbes regulate gene expression in response to population density through the production and detection of signaling molecules called autoinducers. The document discusses the history of quorum sensing, mechanisms, types of signaling, and examples of quorum sensing in certain archaeal species such as Natronococcus occultus and Methanosaeta harundinacea. It also outlines potential applications and future research directions regarding quorum sensing in archaea.
Genetic engineering alters the genes of organisms to produce beneficial effects for humans. It has improved crop yields and introduced traits like disease resistance. Scientists have genetically engineered microorganisms to help clean pollution from soil and water. While genetic engineering provides benefits, there are also risks like unintentionally creating allergenic foods or plants becoming invasive "superweeds". However, regulations aim to minimize these risks and the technology could help nutrition and public health when used carefully.
Pseudomonas alcaligenes, potential antagonist against fusarium oxysporum f.s...Alexander Decker
This document summarizes a study on isolating and characterizing the potential of Pseudomonas alcaligenes as a biocontrol agent against Fusarium wilt disease in tomatoes. Three Pseudomonas isolates (KtS1, TrN2, TmA1) were obtained from plant rhizospheres. Biochemical and 16S rRNA gene analysis identified the isolates as P. alcaligenes. In laboratory tests, the P. alcaligenes isolates strongly inhibited the growth of Fusarium oxysporum f.sp. lycopersici, the causal agent of Fusarium wilt, by over 80%. When applied to tomato plants under greenhouse conditions, the P. alcaligen
This document discusses various applications of biotechnology including therapeutics, diagnostics, food production, environmental applications, agriculture, and chemical production. It also describes techniques such as genetic engineering, DNA probes, DNA sequencing, PCR, gene therapy, biosensors, biochips, nanoparticles, assisted reproductive technologies, vaccine development, hybridoma technology, stem cell technology, and fermentation technology. The key applications and components of these techniques are summarized.
This document discusses the topic of pathogenomics in plant pathology. It begins with an introduction to key terms and techniques used in pathogenomics such as marker genes, effectors, and high throughput gene sequencing. It then discusses the role of effectors in pathogenesis and host-pathogen interactions. It provides examples of pathogenomic studies on various pathogens such as Puccinia graminis f. sp. tritici (wheat rust) and Xanthomonas axonopodis pv. manihotis (cassava bacterial blight). It discusses how pathogenomics can help develop diagnostic tools, provide durable resistance to plants, and uncover plant processes through analysis of pathogen genomes and effectors.
Functional Genomics of Plant Pathogen interactions in Wheat Rust PathosystemSenthil Natesan
Cereal rust fungi are pathogens of major importance to agriculture, threatening cereal production worldwide. Targeted breeding for resistance, based on information from fungal surveys and population structure analyses of virulence, has been effective. Nevertheless, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to determine the range of available resistance genes. The development of genomic resources for these fungi and their comparison has released a torrent of new ideas and approaches to use this information to assist pathologists and agriculture in general. The sequencing of gene transcripts and the analysis of proteins from haustoria has yielded candidate virulence factors among which could be defence-triggering avirulence genes. Genome-wide computational analyses, including genetic mapping and transcript analyses by RNA sequencing of many fungal isolates, will predict many more candidates (Bakkeren et al., 2012)
Dissecting the mechanisms of host-pathogen systems like wheat-rust, including pathogen counter-defenses will ensure a step ahead towards understanding current outcomes of interactions from a co-evolutionary point of view, and eventually move a step forward in building more durable strategies for management of diseases caused by fungi (Hadrami et al.,2012)
This power point presentation has described role of biotechnology in management of diseases. This presentation also contains different biotechnological techniques for Treating, Diagnosing, preventing and understanding the disease.
The document provides an overview of biotechnology, including definitions, key concepts, areas of application, and ethical considerations. It defines biotechnology as using living organisms to produce new products or modify existing organisms. Some main points covered include that biotechnology involves genetics, engineering, agriculture, and manipulating DNA. It also discusses early pioneers in the field and how techniques have advanced from classical to modern biotechnology.
Biotechnology is the application of living organisms or their components to industrial processes. It involves techniques like genetic engineering, cell culture, and monoclonal antibody production. Biotechnology has applications in medicine like producing insulin, agriculture like genetically modified crops, and forensics like DNA fingerprinting. While it offers benefits, biotechnology also raises societal issues around ethics, safety, and public awareness that are actively debated.
Genetic engineering involves manipulating genes through processes like isolation, cutting, and transformation to create desired traits. It allows DNA from one organism to be inserted into another. Three key applications are producing human insulin in bacteria, creating vitamin A rice to prevent blindness, and engineering sheep to produce human clotting factors in their milk for hemophiliacs. The overall process generally involves isolation of DNA, cutting and joining DNA, transforming organisms, and expressing the new genes.
1) Agrobacterium tumefaciens is a soil bacterium that was discovered to transfer genes between itself and plants, enabling the development of genetic engineering methods for plants.
2) The most common transgenic traits in crops include herbicide and insect resistance, with field corn often containing Bt genes for insect resistance.
3) Agrobacterium-mediated transformation is the most widely used method for producing transgenic plants. It involves using disarmed Agrobacterium strains to transfer desired gene sequences into plant cells.
This curriculum vitae outlines the educational and professional background of Julio A. Urbina R. He received a Licenciado in Biology from the Central University of Venezuela in 1970 and a Ph.D. in Chemistry from the Massachusetts Institute of Technology in 1975. His positions have included professorships at the University of Cincinnati and Central University of Venezuela. He has also held various research positions at the Venezuelan Institute for Scientific Research since 1991. The CV lists over 40 publications in peer-reviewed journals related to biological chemistry and parasitology research.
An introduction to biotechnology 27.01.2015 tutorial group g1 (sec a&b)Smita Shukla
This document discusses biotechnology, including its history, applications, and future. Biotechnology uses living organisms to benefit humanity and involves fields like microbiology, agriculture, medicine, forensics, and more. It has a long history including fermentation and selective breeding. Modern biotech also includes genetic engineering. The human genome project provided insights into gene functions and diseases. Biotechnology requires interdisciplinary skills and generates jobs in research, manufacturing, and marketing. It faces challenges in applying genomic insights through gene therapy and personalized medicine.
This document discusses mutation breeding to develop disease resistance in crops. It describes how mutations create genetic variability in pathogens, occurring naturally at low rates. Mutation breeding has been used to develop crop varieties with enhanced resistance to various diseases like viruses, bacteria, and some fungi. Examples are given of mutant crop varieties with improved resistance developed through induced mutagenesis, including chickpea and mungbean varieties. The document concludes that mutation breeding and induced mutagenesis are useful tools for improving quantitative and qualitative traits in crops, including developing disease resistance.
This document summarizes research on cloning and expression analysis of rice genes involved in infection with the rice nematode Hirschmaniella oryzae. Key points include:
- Six rice genes were selected based on previous expression data under H. oryzae infection. These genes were cloned from rice roots.
- An infection experiment was conducted where rice seedlings were infected with nematodes at different time points. Gene expression was analyzed using qPCR.
- Preliminary results found three genes - Cupin, Membrane, and B-box - had expression patterns consistent with previous data under H. oryzae infection. Further research is suggested to understand the roles of these genes in rice-
Wireless Sensor Grids Energy Efficiency Enrichment Using Quorum TechniquesIOSR Journals
This document proposes a Quorum-based Medium Access Control (QMAC) protocol to improve energy efficiency in wireless sensor networks. QMAC enables sensor nodes to sleep longer under light traffic loads by only waking up during assigned "quorum time frames". Each node selects one row and column from a grid as its quorum set. This ensures any two nodes' quorums will intersect at some time, allowing communication while keeping individual duty cycles low. Results show QMAC conserves more energy and maintains low latency compared to existing protocols that require nodes to wake up at every time frame regardless of traffic.
IOSR journal of VLSI and Signal Processing (IOSRJVSP) is an open access journal that publishes articles which contribute new results in all areas of VLSI Design & Signal Processing. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced VLSI Design & Signal Processing concepts and establishing new collaborations in these areas.
The document discusses a lecture on biotechnology given by Dr. Srinivasreddy Patil. It covers topics like the introduction and tools of genetic engineering, including vectors, enzymes, and host cells. Recombinant DNA technology and its applications are explained, using the example of insulin synthesis. Other topics covered include DNA fingerprinting, gene therapy, the human genome project, and monoclonal antibodies. The document also addresses the hazards and safeguards of genetic engineering.
Biotechnology uses genes from different organisms to modify biological functions and create products to benefit society. It has applications in gene therapy, cancer treatment, vaccines, and more. Techniques include adding genes to crops to increase vitamin levels or tolerance to environmental stresses. DNA is delivered using organisms like Agrobacterium. Medical biotechnology aims to prolong life through monoclonal antibodies, bioprocessing insulin from bacteria, stem cell therapies, and tissue engineering to replace damaged tissues.
This document discusses biotechnology and genetic engineering. It provides examples of how biotechnology is used in forensics, agriculture, and genetic engineering. Genetic engineering involves transferring genes between organisms, such as placing human genes in bacteria. The document also discusses applications of genetic engineering like creating pest-resistant and herbicide-resistant crops through biotechnology techniques.
This document presents information on quorum sensing in archaea. It defines quorum sensing as a mechanism by which microbes regulate gene expression in response to population density through the production and detection of signaling molecules called autoinducers. The document discusses the history of quorum sensing, mechanisms, types of signaling, and examples of quorum sensing in certain archaeal species such as Natronococcus occultus and Methanosaeta harundinacea. It also outlines potential applications and future research directions regarding quorum sensing in archaea.
Genetic engineering alters the genes of organisms to produce beneficial effects for humans. It has improved crop yields and introduced traits like disease resistance. Scientists have genetically engineered microorganisms to help clean pollution from soil and water. While genetic engineering provides benefits, there are also risks like unintentionally creating allergenic foods or plants becoming invasive "superweeds". However, regulations aim to minimize these risks and the technology could help nutrition and public health when used carefully.
Pseudomonas alcaligenes, potential antagonist against fusarium oxysporum f.s...Alexander Decker
This document summarizes a study on isolating and characterizing the potential of Pseudomonas alcaligenes as a biocontrol agent against Fusarium wilt disease in tomatoes. Three Pseudomonas isolates (KtS1, TrN2, TmA1) were obtained from plant rhizospheres. Biochemical and 16S rRNA gene analysis identified the isolates as P. alcaligenes. In laboratory tests, the P. alcaligenes isolates strongly inhibited the growth of Fusarium oxysporum f.sp. lycopersici, the causal agent of Fusarium wilt, by over 80%. When applied to tomato plants under greenhouse conditions, the P. alcaligen
This document discusses various applications of biotechnology including therapeutics, diagnostics, food production, environmental applications, agriculture, and chemical production. It also describes techniques such as genetic engineering, DNA probes, DNA sequencing, PCR, gene therapy, biosensors, biochips, nanoparticles, assisted reproductive technologies, vaccine development, hybridoma technology, stem cell technology, and fermentation technology. The key applications and components of these techniques are summarized.
This document discusses the topic of pathogenomics in plant pathology. It begins with an introduction to key terms and techniques used in pathogenomics such as marker genes, effectors, and high throughput gene sequencing. It then discusses the role of effectors in pathogenesis and host-pathogen interactions. It provides examples of pathogenomic studies on various pathogens such as Puccinia graminis f. sp. tritici (wheat rust) and Xanthomonas axonopodis pv. manihotis (cassava bacterial blight). It discusses how pathogenomics can help develop diagnostic tools, provide durable resistance to plants, and uncover plant processes through analysis of pathogen genomes and effectors.
Functional Genomics of Plant Pathogen interactions in Wheat Rust PathosystemSenthil Natesan
Cereal rust fungi are pathogens of major importance to agriculture, threatening cereal production worldwide. Targeted breeding for resistance, based on information from fungal surveys and population structure analyses of virulence, has been effective. Nevertheless, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to determine the range of available resistance genes. The development of genomic resources for these fungi and their comparison has released a torrent of new ideas and approaches to use this information to assist pathologists and agriculture in general. The sequencing of gene transcripts and the analysis of proteins from haustoria has yielded candidate virulence factors among which could be defence-triggering avirulence genes. Genome-wide computational analyses, including genetic mapping and transcript analyses by RNA sequencing of many fungal isolates, will predict many more candidates (Bakkeren et al., 2012)
Dissecting the mechanisms of host-pathogen systems like wheat-rust, including pathogen counter-defenses will ensure a step ahead towards understanding current outcomes of interactions from a co-evolutionary point of view, and eventually move a step forward in building more durable strategies for management of diseases caused by fungi (Hadrami et al.,2012)
This power point presentation has described role of biotechnology in management of diseases. This presentation also contains different biotechnological techniques for Treating, Diagnosing, preventing and understanding the disease.
The document provides an overview of biotechnology, including definitions, key concepts, areas of application, and ethical considerations. It defines biotechnology as using living organisms to produce new products or modify existing organisms. Some main points covered include that biotechnology involves genetics, engineering, agriculture, and manipulating DNA. It also discusses early pioneers in the field and how techniques have advanced from classical to modern biotechnology.
Biotechnology is the application of living organisms or their components to industrial processes. It involves techniques like genetic engineering, cell culture, and monoclonal antibody production. Biotechnology has applications in medicine like producing insulin, agriculture like genetically modified crops, and forensics like DNA fingerprinting. While it offers benefits, biotechnology also raises societal issues around ethics, safety, and public awareness that are actively debated.
Genetic engineering involves manipulating genes through processes like isolation, cutting, and transformation to create desired traits. It allows DNA from one organism to be inserted into another. Three key applications are producing human insulin in bacteria, creating vitamin A rice to prevent blindness, and engineering sheep to produce human clotting factors in their milk for hemophiliacs. The overall process generally involves isolation of DNA, cutting and joining DNA, transforming organisms, and expressing the new genes.
1) Agrobacterium tumefaciens is a soil bacterium that was discovered to transfer genes between itself and plants, enabling the development of genetic engineering methods for plants.
2) The most common transgenic traits in crops include herbicide and insect resistance, with field corn often containing Bt genes for insect resistance.
3) Agrobacterium-mediated transformation is the most widely used method for producing transgenic plants. It involves using disarmed Agrobacterium strains to transfer desired gene sequences into plant cells.
This curriculum vitae outlines the educational and professional background of Julio A. Urbina R. He received a Licenciado in Biology from the Central University of Venezuela in 1970 and a Ph.D. in Chemistry from the Massachusetts Institute of Technology in 1975. His positions have included professorships at the University of Cincinnati and Central University of Venezuela. He has also held various research positions at the Venezuelan Institute for Scientific Research since 1991. The CV lists over 40 publications in peer-reviewed journals related to biological chemistry and parasitology research.
An introduction to biotechnology 27.01.2015 tutorial group g1 (sec a&b)Smita Shukla
This document discusses biotechnology, including its history, applications, and future. Biotechnology uses living organisms to benefit humanity and involves fields like microbiology, agriculture, medicine, forensics, and more. It has a long history including fermentation and selective breeding. Modern biotech also includes genetic engineering. The human genome project provided insights into gene functions and diseases. Biotechnology requires interdisciplinary skills and generates jobs in research, manufacturing, and marketing. It faces challenges in applying genomic insights through gene therapy and personalized medicine.
This document discusses mutation breeding to develop disease resistance in crops. It describes how mutations create genetic variability in pathogens, occurring naturally at low rates. Mutation breeding has been used to develop crop varieties with enhanced resistance to various diseases like viruses, bacteria, and some fungi. Examples are given of mutant crop varieties with improved resistance developed through induced mutagenesis, including chickpea and mungbean varieties. The document concludes that mutation breeding and induced mutagenesis are useful tools for improving quantitative and qualitative traits in crops, including developing disease resistance.
This document summarizes research on cloning and expression analysis of rice genes involved in infection with the rice nematode Hirschmaniella oryzae. Key points include:
- Six rice genes were selected based on previous expression data under H. oryzae infection. These genes were cloned from rice roots.
- An infection experiment was conducted where rice seedlings were infected with nematodes at different time points. Gene expression was analyzed using qPCR.
- Preliminary results found three genes - Cupin, Membrane, and B-box - had expression patterns consistent with previous data under H. oryzae infection. Further research is suggested to understand the roles of these genes in rice-
Wireless Sensor Grids Energy Efficiency Enrichment Using Quorum TechniquesIOSR Journals
This document proposes a Quorum-based Medium Access Control (QMAC) protocol to improve energy efficiency in wireless sensor networks. QMAC enables sensor nodes to sleep longer under light traffic loads by only waking up during assigned "quorum time frames". Each node selects one row and column from a grid as its quorum set. This ensures any two nodes' quorums will intersect at some time, allowing communication while keeping individual duty cycles low. Results show QMAC conserves more energy and maintains low latency compared to existing protocols that require nodes to wake up at every time frame regardless of traffic.
IOSR journal of VLSI and Signal Processing (IOSRJVSP) is an open access journal that publishes articles which contribute new results in all areas of VLSI Design & Signal Processing. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced VLSI Design & Signal Processing concepts and establishing new collaborations in these areas.
Design of Gabor Filter for Noise Reduction in Betel Vine leaves Disease Segme...IOSR Journals
This document describes a design of a Gabor filter for noise reduction in images of betel vine leaves to aid in disease segmentation. A Gabor filter is designed using Verilog HDL and implemented on a CADENCE platform. The filter takes pixel inputs from images that have undergone preprocessing like Sobel edge detection and segmentation. It convolves the pixels with stored filter coefficients to reduce noise and segment the diseased areas. The proposed Gabor filter achieves noiseless segmentation with increased speed and reduced delay compared to existing methods. It utilizes fewer resources with minimal warnings. The system could be enhanced further with 2D and 3D image processing and neural network training.
Investigation of Thermal Insulation on Ice CoolersIOSR Journals
This document investigates different materials for thermal insulation in ice coolers. It tests coconut fibre, polystyrene, and polyurethane at various densities using the Lee's Disk method to determine their thermal conductivity. The study finds that polyurethane with a density of 95kg/m3 has the lowest thermal conductivity of 0.0195 W/mK. Numerical analysis confirms that polyurethane of this density and thickness of 64mm maintains the lowest inside temperature for an ice cooler. The experimental data and numerical analysis show that polyurethane of 95kg/m3 density and 64mm thickness provides the best thermal insulation to minimize heat transfer and increase ice melting time in coolers.
Modified Distributive Arithmetic Based DWT-IDWT Processor Design and FPGA Imp...IOSR Journals
1) The document describes a modified distributive arithmetic based discrete wavelet transform (DWT) processor architecture and its FPGA implementation for image compression.
2) The proposed architecture uses four lookup tables to store pre-computed partial products of filter coefficients, achieving a latency of 44 clock cycles and throughput of 4 clock cycles.
3) A software reference model is developed in Matlab to analyze the performance of various wavelets for image compression using the distributive arithmetic based DWT approach. The input image is resized and decomposed into sub-bands using DWT and reconstructed using IDWT.
Modeling Object Oriented Applications by Using Dynamic Information for the I...IOSR Journals
This paper presents an iterative approach to recover collaborations from object-oriented applications using dynamic information. It develops a prototype tool called the Collaboration Browser to demonstrate this approach. The Collaboration Browser allows developers to query runtime information to understand collaborations between classes. It presents dynamic information through panels listing sender classes, receiver classes, invoked methods, and collaboration patterns. Developers can iteratively filter information and focus on specific collaborations. The paper tests the Collaboration Browser on a sample Java application, recovering 19 collaboration patterns by posing 18 queries. It concludes the approach effectively discovers important collaborations and roles classes play within them.
Applying a Model Based Testing for a Controller Design in Fault Detection, I...IOSR Journals
The document describes a model-based testing approach for a fault detection, isolation, and recovery (FDIR) system for an aircraft elevator redundancy control system. It discusses applying model-based design to develop an executable specification of the system to facilitate early verification and validation. The system contains four hydraulic actuators that can each be in one of five modes (active, standby, off, passive, isolated). Requirements for the system are presented and translated into more detailed specifications. A Simulink model is created to embody the desired behavior based on the requirements. The model includes fault detection subsystems to monitor actuator positions and hydraulic pressures and isolate faults. The approach aims to test the model against the requirements to verify compliance and catch
Correlation Study For the Assessment of Water Quality and Its Parameters of G...IOSR Journals
In the present work water samples are collected from six different Ghats of Ganga river in Kanpur city from March 2010 to February 2011 on monthly basis and water quality assessment is carried out. Pearson’s correlation coefficient (r) value is determined using correlation matrix to identify the highly correlated and interrelated water quality parameters. To test the significance of the pair of parameters p-value is carried out and in order to test the joint effects of several independent variables, without frequent or repeated monitoring of water quality in a location. Higher concentration of Chromium (6.7 mg/l) at Siddhnath ghat in June, and its monthly variation showed highly adverse effect on river Ganga due to tanneries effluent. It is found that significant positive correlation holds for Temp vs BOD GH1 (r= 0.99, p<0.01),><0.01),><0.01);><0.01),><0.01),><0.01).><0.01),><0.01),><0.01). Chromium is found that non significant correlation. The mean values of all the measured physico-chemical parameters of Ganga river water are within the highest desirable limit set by WHO except BOD.
Phytochemical, cytotoxic, in-vitro antioxidant and anti-microbial investigati...IOSR Journals
Zizyphus rugosa Lam. (Family: Rhamnaceae), locally known as “Bon Boroi” or as “Jongli Boroi” in Bangladesh generally found as a herb on the hills in bunches on thorny branches of the Zizyphus rugosa trees. Its bark and wood are used medicinally for dysentery in China, India, Laos, Burma, Sri Lanka, Thailand and Vietnam. Phytochemical screening of the Leaf extract of Zizyphus rugosa Lam showed different phytoconstituents including carbohydrates (monosaccharides, reducing and mixed-reducing sugars), alkaloid, glycosides, steroids, tannins and saponin. No flavonoid was detected. In DPPH and NO radical scavenging methods, IC50 was moderately satisfactory. IC50 was found 179.713μg/ml and 769.909μg/ml respectively compare with the reference ascorbic acid (15.707μg/ml and 82.642μg/ml respectively). In LPO (Lipid peroxidation) assay the Leaf fraction extract showed moderate inhibition potentiality (IC50 402.835μg/ml) in comparison to standard drug BHT (IC50 32.94μg/ml). In CUPRAC assays, the fraction was found to possess low Total antioxidant content, good flavonoid, and moderate amounts of phenolics, tannin and alkaloid content. The Leaf fraction extract was found to show good toxicity to Brine Shrimp nauplii, (LC50 212.402μg/ml & LC90 10715.91μg/ml) compare with the reference anticancer drug vincristine sulphate (LC50 2.47μg/ml & LC90 42μg/ml). In the antimicrobial study the fraction showed moderate activity against only one bacterium (Shiggla sonni) while the standard drug Chloramphenicol showed very good zone of inhibition against all five types (Salmonella typhi, Staphylococcus aureus, Shiggla sonni, Salmonella paratyphi, Salmonella grb) of bacteria. These findings provide scientific basis for the use of Zizyphus rugosa Lam. leaf ethanolic extract in traditional medicine in the treatment of aforementioned diseases. The plant also possesses moderate antimicrobial activity, good cytotoxic and good to moderate antioxidant activity.
This document analyzes the stress on helical coil springs made of different materials that are used in two-wheeler vehicles. It discusses the modeling of a spring in CATIA software and analyzing it in ANSYS. Four materials are considered - structural steel, aluminum alloy, titanium alloy, and chrome vanadium. The maximum shear stress and total deformation of each material under load are calculated and chrome vanadium is found to have the lowest stress and deformation, making it the best material out of the four considered for springs.
- The document experimentally investigates and optimizes welding parameters for TIG welding of 7005 aluminium alloy. TIG welding was used to weld 5mm thick 7005 aluminium alloy plates while varying the welding parameters.
- Welding current, gas flow rate, welding speed, and electrode gap were selected as input parameters to study their effect on the tensile strength and hardness of the welded joints, which were selected as output responses.
- An L9 orthogonal array based on Taguchi methods was used to design the welding experiments. The experiments analyzed the effect of parameters on tensile strength and hardness using signal-to-noise ratios. Welding current was found to have the greatest influence on tensile
Flash chromatography guided fractionation and antibacterial activity studies ...IOSR Journals
This document summarizes a study that fractionated extracts of Angelica archangelica roots using flash chromatography and tested the fractions for antibacterial activity. Several fractions showed promising antibacterial activity, with minimum inhibitory concentrations ranging from 125-500 μg/ml against four bacterial strains. The most active fractions were from methanol extracts. All ethyl acetate fractions exhibited activity. Further investigation of these fractions could uncover bioactive compounds responsible for the plant's traditional medicinal uses.
This document summarizes an experiment on enhancing the heat transfer efficiency of a counter flow heat exchanger by using API SN oil and Super Kool Xtra oil. The experimental setup uses a copper tube heat exchanger with the hot fluid passing through the inside of the copper tube and the cold fluid passing over the outside. Temperature readings are taken at the inlet and outlet of both fluids. The results show that API SN oil provides greater heat transfer efficiency than water or Super Kool Xtra oil based on the temperature changes of the fluids. The heat exchanger has applications in industries involving heat transfer like oil/gas, power generation, and industrial processing.
Model for Identifying the Security of a System: A Case Study of Point Of Sale...IOSR Journals
This document presents a model for identifying security requirements of a system during the requirements analysis phase. The model uses use case diagrams along with security questionnaires tables. A use case diagram depicts the functional requirements and interactions between actors and the system. The proposed model adds a security questionnaires table for each use case/process in the diagram to identify related security requirements. The document implements the model on a point of sale system case study, presenting sample security questionnaires tables for the login, add product, and view product processes. The tables contain security-related questions to address during requirements. The model aims to incorporate security early in development to avoid later issues.
The study of semiconductor layer effect on underground cables with Time Domai...IOSR Journals
This document presents a study on how the semiconductor layers in underground cables can affect Time Domain Reflectometry (TDR) measurements. The researchers developed a circuit model that includes the electrical resistance of the semiconductor layers to better simulate TDR signals. Simulations using the proposed model showed good agreement with measurements from a new cable but not an aged cable. The model was updated to represent resistance in the aged cable's semiconductor layers caused by degradation over time. Simulations with this updated model matched experimental TDR results from the aged cable better than the original model. The study demonstrates that changes in semiconductor layer resistance due to aging can impact TDR pulse propagation in cables.
Spectrophotometric Determination of Drugs and Pharmaceuticals by Cerium (IV) ...IOSR Journals
Simple, sensitive, accurate, and precise spectrophotometric methods for quantitative determination of drugs, viz., Darifenacin (DAR), Esmolol Hydrochloride (ESM), Montelukast Sodium (MON), Sildenafil citrate (SIL),Terbinafine (TER) and Tramadol Hydrochloride (TRA) were developed. The method of each drug depends upon oxidation of drugs by Ce (IV) (Excess) and estimating the amount of unreacted Ce (IV) by amaranth dye at 523nm. The calibration curves obeyed Beer’s law over the concentration range of 1.4-7.0 μg ml-1 (DAR), 2-14 μg ml-1 (ESM), 2-10 μg ml-1 (MON), 20-70 μg ml-1 (SIL), 3-21 μg ml-1 (TER) & 2-14 μg ml-1 (TRA). The methods have been validated in terms of guidelines of ICH and applied to analysis of pharmaceuticals.
Design and Implementation of New Encryption algorithm to Enhance Performance...IOSR Journals
This document summarizes a research paper that proposes a new encryption algorithm to improve performance parameters. The algorithm is divided into two phases. Phase 1 involves reversing, swapping, circularly shifting bits of the plaintext and XORing with the key. Phase 2 divides the output into blocks, then recombines the left bits of each block. The paper analyzes avalanche effect and execution time of the proposed algorithm compared to existing algorithms to evaluate its performance. The results show better performance than existing algorithms.
Design Issues for Search Engines and Web Crawlers: A ReviewIOSR Journals
This document provides a review of design issues for search engines and web crawlers. It discusses how search engines use web crawlers to collect web documents for storage and indexing from the growing World Wide Web. The three main parts of a search engine are the crawler, indexer, and query engine. Crawler-based search engines create listings automatically using algorithms while human-powered directories rely on human organization. Designing efficient search engines and crawlers faces challenges from the diversity of web documents and changing user behaviors. Web crawlers prioritize URLs to download pages and extract new links to update search engine databases.
This document summarizes a research paper on synthesizing speech using a small microcontroller. It describes designing a speech synthesis system using a microcontroller to perform various speech commands. The system uses a PIC18F1320 microcontroller and a TTS256 speech synthesizer chip which concatenates recorded speech segments to generate synthesized speech. Software is developed using MPLAB to control the system and synthesize speech. The system is tested to ensure it can interface with the user, control an audio playback device using the microcontroller, and synthesize speech within the microcontroller.
This document describes a microcontroller-based touch switch system using an ATMega8 microcontroller chip. The system allows multiple touch switches to be added digitally and at low cost compared to analog switches. When a touch point is pressed, the microcontroller detects the input signal, turns on the load by controlling a relay, and when pressed again turns off the load. The system provides a safe and reliable switching method that can be used for household applications and to control loads from a distance.
Control of metabolic activities of E.coli and S. aureus bacteria by Electric ...researchinventy
Low electric currents generated using conductive electrodes have been used to increase the efficacy of antibiotics against bacterial biofilms, a phenomenon termed “the bioelectric effect” that formed metal ions and free radicals which can inhibit the growth of planktonic Staphylococcus aureus (S.aureus) and Escherichia Coli (E.Coli) the effect is amplitude and frequency dependent, the aim of present study to define the parameters that are most effective against bacterial growth also to investigate the comparative study through inactivation of metabolic activities, growth rate, morphology, bacterial conductivity and antibiotic sensitivity between gram negative E.Coli and gram positive S.aureus bacteria by extremely low frequency electric field (ELF-EF). In this work, the frequency of electric impulses that interfere with the bioelectric signals generated during E.Coli and S.aureus cellular division is investigated in order to compare cell viability, number of colony forming units (CFU) and growth rate (optical density at 600nm) bacterial conductivity and antibiotic susceptibility. Also morphological cellular structure was investigated by transmission electron microscope (TEM). The results revealed that a highly significant inhibition effect occurred when S.aureus and E.Coli was exposed to resonance of 0.8, 0.5 Hz square amplitude modulated waves (QAMW) respectively for 2hours exposure .Moreover, exposed cells became more sensitive to the tested antibiotics compared to control. Significant ultra-structural changes occurred as observed by TEM which indicated morphological changes. It will be concluded that, the use of 0.8, 0.5 Hz QAMW in controlling the biological activity of S.aureus and E.coli respectively seems to be a new and promising medical activity
Effects of electric field on histopathological study, electrical properties a...inventy
The present work was undertaken in order to investigate the effects of electric field (EF) of strength 50Hz-3KV/m on the histopathology, dielectric properties and liver function tests in albino rats. Fifty male albino rats were equally divided into three groups namely A, B, and C. Animals of group A used as control group which didn't receive any treatment . Animals of group B was divided into two subgroups namely B1 and B2 which were discretely exposed to 50HZ, 3KV/m electric field for a period of 15 day (8 hours/day, 5day/week). Group B2 animals were left to survive and housed at normal environmental conditions similar to control group A for a period of 15 day post exposed. Animals of group C are divided into two subgroups namely C1 and C2 were discretely exposed to the electric field for a period of 30 day (8 hours/day, 5day/week). Group C2 animals were left to survive and housed at normal environmental conditions similar to control group A for a period of 15 day post exposed. At the end of this period, blood and tissues samples were collected from all groups for experimental investigations. The dielectric constant (έ), electrical conductivity (σ) was measured in frequency range 42Hz-5MHz to investigate any changes in liver structure through studding histopathological examination. Also, the liver function was studied through analysis of glutamic oxaloacetic transaminase (GOT), glutamic pyruvie transaminase (GPT) and total protein (TP) after exposure to electric field this biochemical parameters have been evaluated in the blood serum of rats. The obtained results show high significant changes in the value of έ and σ of liver tissues for all groups exposed to EF as compared with control group. The levels of GOT and GPT were increased up to four times their values during the period of exposure to EF. These variations were recovered during two week after stopping exposure but they did not return to its original control values before exposure. On microscopic level; liver histological observations in liver cells which revealed some alterations including hepatic tissue with two portal tracts showing mild florous expansion and a dilated central vein, also ghosts of hepatocytes denoting necrotic changes also shows hepatic tissue with dilated central veins engorged with blood and splitting out to adjacent hepatocytes.
This study examined the effects of exposure to 2.45 GHz Wi-Fi radiation on male reproductive organs in rats over time. Rats were exposed to Wi-Fi radiation for either 1 hour or 7 hours per day for 2 months. Exposure led to decreased sperm parameters and increased apoptosis in the testes in a time-dependent manner. Both exposure groups also showed reduced seminal vesicle weight compared to unexposed controls. The study suggests that long-term exposure to Wi-Fi radiation may have negative impacts on male fertility.
Bio-impedance detector for Staphylococcus aureus exposed to magnetic fieldsجنة الربيع
This document discusses a study that used bioimpedance measurements to analyze the effect of magnetic fields on the growth of Staphylococcus aureus bacteria. The study found that exposure to DC magnetic fields caused impedance to fall, indicating inhibited bacterial growth. In contrast, exposure to AC magnetic fields caused impedance to increase, enhancing bacterial growth. An impedance system was constructed to measure the impedance of bacterial samples over time and under different magnetic field conditions. Statistical analysis found significant differences in impedance between control samples and samples exposed to DC or AC magnetic fields.
Magnetic field to improve fermentation kinetics for ethanol production Iowa State University
Two experiments were conducted to analyze the influence that magnetic fields have on cell growth and ethanol production during fermentation. The first experiment was conducted for 25 hours at a 2% dextrose loading rate with a homogeneous and non-homogeneous static magnetic field of 100 mT and 200 mT, respectively. The second experiment was conducted for 30 hours at a 6% dextrose loading rate with a non-homogeneous static magnetic field of 200 mT. The results indicated that homogeneous magnetic fields did not have a significant effect on the yeast cell growth. However, the non-homogeneous static magnetic field resulted in about 8% more peak ethanol concentration than the control for the 2% dextrose loading rate.
The document discusses a primary screening of actinomycetes isolated from arid zones in Kazakhstan for their potential antitumor activity. 157 actinomycete strains were tested against Staphylococcus aureus 209P and its mutants UF-2 and UF-3 using an agar block technique. 36 strains from sandy soils and 6 from plant rhizospheres showed activity against S. aureus 209P. 22 strains from takyrs and takyr-like soils had at least twice as much activity against the mutants compared to the stock strain, indicating potential to produce antitumor antibiotics. In total, it was estimated that 24.2% of the actinomycete strains may be potential producers of antit
Seminar plantlet response to seismomorphogenic stimuli (mechanical stress med...Daya Singh
Mechanical stress-mediated acclimatization of in vitro regenerated plantlets is probably worth to be more investigated in future research since it serves as a non-chemical and cost-effective approach. Its expediency on potentially improving plants’ quality and reducing mortality percentage of plantlets provides an open field for future research.
This study used an electrotaxis assay to separate Caenorhabditis elegans nematodes into groups based on their crawling speed in response to an electric field. Nematodes that crawled more slowly had shorter lifespans, higher levels of protein damage, and lower heat shock resistance than faster nematodes. Gene expression analysis found that slow nematodes had higher transcript levels of heat shock genes, which correlated with their poorer stress response and shorter lifespan. The results suggest that accumulation of early-life damage leads to faster age-related deterioration and a shorter lifespan.
The effect of the non thermal plasma needle on pseudomonas aeruginosa bacteriaIbrahim Karim
The reduction of the use of antibiotics and dependence on devices and tools that link between physics and modern therapeutic medicine led to a modern leap in the treatment of patients. In this research was designed nonthermal
plasma needle system at the normal atmosphere pressure and working on argon gas, the system was applied to gram positive Staphylococcus aureus bacteria isolated from patients with burns from Yarmouk Teaching Hospital, wounds and Burns Division. The bacteria were exposed to non-thermal plasma generated at different time intervals and at two values of voltages (4.9, 8). The killing percentage depends on the non-thermal plasma needle system operating
conditions such as gas flow, applied voltage on bacteria and distance between tip needle and isolates (Staphylococcus
aureus) bacteria, the perfect and partial killing percentage increase with the applied voltage increasing. The result showed various killing percentage were obtained for the bacteria. A perfect killing percentage of these bacteria was obtained at time (6 min) and the applied voltage were (8 kV) and gas flow (5 l/min).
1) The document reports on research into the endophytic fungus Papulaspora pallidula's ability to biosynthesize silver nanoparticles (AgNPs) and their potential antitumor and antibacterial efficacy.
2) The biosynthesized AgNPs exhibited 52.7% growth inhibition of human larynx carcinoma cells and varying levels of inhibition against 5 pathogenic bacterial strains. Combining the AgNPs with Gentamycin significantly increased antibacterial activity.
3) Characterization of the AgNPs showed they were spherical and ranged from 8-90nm in size. UV-Vis and FTIR analysis confirmed AgNP formation and protein capping, while SEM images visualized particle shape and dispersion.
Space Microbiology: Modern Research and Advantages for Human Colonization on ...AnuragSingh1049
Astromicrobiology or exomicrobiology, is the study of microorganisms in outer space. Microorganisms in outer space are most wide spread form of life on Earth, and are capable of colonising any environment, this article usually focus on microbial life in the field of astrobiology. Microorganisms exhibit high adaptability to extreme environments of outer space via phenotypic and genetic changes. These changes may affect astronauts in the space environment as well as on earth because mutant microbes will inevitably return with the spacecraft. In this article, the advantages and disadvantages of microbes in outer space are discussed. We all know that outer space is extreme and very complex environment, microorganisms readily adapt to changes in environmental variables, such as weightlessness, cosmic radiation, temperature, pressure and nutrient levels, and these microorganisms exhibit a variety of morphological and physiological changes. Space conditions may significantly increase the mutation frequency of certain genes in microorganisms, which could allow the cultivation of the bacterial mutants, followed by screening of the bacteria for large scale production. Also we can extract microbial secondary metabolites as medicine, flavouring and nutritional drugs. This article provides the planetary exploration and also provides the microbial observatory program on ISS. The aim of this article will also help us to determine the benefits of bacteria and other microorganisms in case of “Human colonization on Mars”.
This document summarizes key findings from the genome sequencing of the oomycete plant pathogen Magnaporthe grisea, which causes rice blast disease. Some key points:
- The draft genome sequence was 38.8 megabases in length and contained a large number of genes encoding secreted proteins and carbohydrate-binding domains that help the pathogen infect plants.
- The genome also contained an expanded family of G-protein coupled receptors and many genes involved in secondary metabolism, both of which are important for fungal pathogenesis.
- Expression of several of these genes increased during early infection, suggesting they play a role in M. grisea's ability to infect rice plants and cause disease.
This document summarizes a study that assessed the phototoxicity of various xanthene derivatives against E. coli, S. aureus, and S. cerevisiae. Without light exposure, the compounds showed similar inherent toxicity to each organism, dependent on chemical structure. Upon illumination, the compounds demonstrated phototoxicity, with stronger effects on Gram-positive bacteria and yeast. Compounds with more halogen substituents generated higher levels of reactive oxygen and showed greater phototoxic activity. The results suggest that xanthene derivatives have potential as alternative antimicrobial agents.
wheat article samar final reprint 2014 okSamar Adel
This study investigated biochemical, histological, and molecular changes in susceptible and resistant wheat cultivars inoculated with the stripe rust fungus Puccinia striiformis f. sp. tritici. Disease severity, symptoms, and electrolyte leakage were lower in resistant cultivars, while chlorophyll concentrations were higher. Resistant cultivars over-accumulated the Yr18 resistant gene and had higher reactive oxygen species and lower antioxidant enzyme activities. Susceptible cultivars were colonized extensively by the fungus with many hyphae and haustoria, while resistant cultivars restricted fungal growth and development.
- Experiments tested the effect of extracellular self-DNA (exDNA) and heterologous DNA on the growth of 6 species from different taxonomic groups, including bacteria, fungi, algae, plants, protozoa and insects.
- Treatments with conspecific exDNA produced a concentration-dependent growth inhibition in all species, whereas heterologous DNA did not cause inhibition except in one bacterial species.
- The results suggest exDNA may have a general inhibitory effect on biological systems, providing a potential mechanism for self-inhibition and negative feedback observed in different organisms. Further investigation is needed to understand the molecular mechanisms of this effect.
This study investigated the effects of pulsed electromagnetic fields (PEMF) and sinusoidal electromagnetic fields (SEMF) on rat testes. Twenty-seven rats were exposed to 1.5 mT of 50 Hz PEMF or SEMF for 6 hours per day, 5 days a week for 28 days. Histological analysis found that SEMF exposure decreased seminiferous tubule basement membranes. PEMF and SEMF exposure also decreased expression of E-cadherin and type IV collagen. The results suggest PEMF and SEMF exposure can adversely affect rat testes at the histological and molecular level.
This document summarizes a study that evaluated the antimicrobial activity of crude culture filtrate and methanol extract of the mushroom Stereum ostrea against bacteria. Key findings:
- Crude culture filtrate of S. ostrea showed the highest inhibitory activity against both gram-positive and gram-negative bacteria based on zone of inhibition tests, with the strongest effect against Bacillus subtilis. Methanol extract also inhibited bacterial growth but to a lesser degree.
- The minimum inhibitory concentration of both crude extract and methanol extract was 20μl for B. subtilis and 30μl for other tested bacteria.
- Results indicate S. ostrea contains metabolites with potential broad-spectrum antimicrobial properties that
"Keeping up with the plant destroyers." My talk at The Royal Society, 7 March...Sophien Kamoun
Tackling emerging threats to animal health, food security and ecosystem resilience, The Royal Society, Monday 7 – Tuesday 8 March 2016. https://royalsociety.org/events/2016/03/emerging-fungal-threats/
This document proposes a study on factors of resistance in maize plants against the spotted stem borer, Chilo partellus. The study will assess molecular diversity and biochemical/nutrient levels in maize cultivars to establish correlations with borer infestation levels. It will also examine physical resistance factors like plant architecture, stem diameter, and leaf trichome density. The research will involve growing 26 maize genotypes and quantifying borer damage, molecular profiles, nutrient levels, and physical traits to identify sources of resistance.
A novel biological rote of α l-fucose in mutans group streptococciAlexander Decker
This document summarizes a study on the inhibitory effects of α-L-fucose on the growth of mutans group streptococci bacteria, which are common causes of dental caries and periodontal disease. Samples were collected from 50 patients, and 20 isolates of mutans streptococci were identified, including 10 Streptococcus mutans, 8 Streptococcus salivaris, and 2 Streptococcus oralis. The study found that α-L-fucose inhibited the growth of these bacteria, with the minimum inhibitory concentration being 80mM. The mechanism of inhibition is proposed to involve the fucose metabolism pathway in these bacteria. The findings suggest that α-L-fucose may be useful as an anti-
Similar to 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis Bacteria (20)
This document provides a technical review of secure banking using RSA and AES encryption methodologies. It discusses how RSA and AES are commonly used encryption standards for secure data transmission between ATMs and bank servers. The document first provides background on ATM security measures and risks of attacks. It then reviews related work analyzing encryption techniques. The document proposes using a one-time password in addition to a PIN for ATM authentication. It concludes that implementing encryption standards like RSA and AES can make transactions more secure and build trust in online banking.
This document analyzes the performance of various modulation schemes for achieving energy efficient communication over fading channels in wireless sensor networks. It finds that for long transmission distances, low-order modulations like BPSK are optimal due to their lower SNR requirements. However, as transmission distance decreases, higher-order modulations like 16-QAM and 64-QAM become more optimal since they can transmit more bits per symbol, outweighing their higher SNR needs. Simulations show lifetime extensions up to 550% are possible in short-range networks by using higher-order modulations instead of just BPSK. The optimal modulation depends on transmission distance and balancing the energy used by electronic components versus power amplifiers.
This document provides a review of mobility management techniques in vehicular ad hoc networks (VANETs). It discusses three modes of communication in VANETs: vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and hybrid vehicle (HV) communication. For each communication mode, different mobility management schemes are required due to their unique characteristics. The document also discusses mobility management challenges in VANETs and outlines some open research issues in improving mobility management for seamless communication in these dynamic networks.
This document provides a review of different techniques for segmenting brain MRI images to detect tumors. It compares the K-means and Fuzzy C-means clustering algorithms. K-means is an exclusive clustering algorithm that groups data points into distinct clusters, while Fuzzy C-means is an overlapping clustering algorithm that allows data points to belong to multiple clusters. The document finds that Fuzzy C-means requires more time for brain tumor detection compared to other methods like hierarchical clustering or K-means. It also reviews related work applying these clustering algorithms to segment brain MRI images.
1) The document simulates and compares the performance of AODV and DSDV routing protocols in a mobile ad hoc network under three conditions: when users are fixed, when users move towards the base station, and when users move away from the base station.
2) The results show that both protocols have higher packet delivery and lower packet loss when users are either fixed or moving towards the base station, since signal strength is better in those scenarios. Performance degrades when users move away from the base station due to weaker signals.
3) AODV generally has better performance than DSDV, with higher throughput and packet delivery rates observed across the different user mobility conditions.
This document describes the design and implementation of 4-bit QPSK and 256-bit QAM modulation techniques using MATLAB. It compares the two techniques based on SNR, BER, and efficiency. The key steps of implementing each technique in MATLAB are outlined, including generating random bits, modulation, adding noise, and measuring BER. Simulation results show scatter plots and eye diagrams of the modulated signals. A table compares the results, showing that 256-bit QAM provides better performance than 4-bit QPSK. The document concludes that QAM modulation is more effective for digital transmission systems.
The document proposes a hybrid technique using Anisotropic Scale Invariant Feature Transform (A-SIFT) and Robust Ensemble Support Vector Machine (RESVM) to accurately identify faces in images. A-SIFT improves upon traditional SIFT by applying anisotropic scaling to extract richer directional keypoints. Keypoints are processed with RESVM and hypothesis testing to increase accuracy above 95% by repeatedly reprocessing images until the threshold is met. The technique was tested on similar and different facial images and achieved better results than SIFT in retrieval time and reduced keypoints.
This document studies the effects of dielectric superstrate thickness on microstrip patch antenna parameters. Three types of probes-fed patch antennas (rectangular, circular, and square) were designed to operate at 2.4 GHz using Arlondiclad 880 substrate. The antennas were tested with and without an Arlondiclad 880 superstrate of varying thicknesses. It was found that adding a superstrate slightly degraded performance by lowering the resonant frequency and increasing return loss and VSWR, while decreasing bandwidth and gain. Specifically, increasing the superstrate thickness or dielectric constant resulted in greater changes to the antenna parameters.
This document describes a wireless environment monitoring system that utilizes soil energy as a sustainable power source for wireless sensors. The system uses a microbial fuel cell to generate electricity from the microbial activity in soil. Two microbial fuel cells were created using different soil types and various additives to produce different current and voltage outputs. An electronic circuit was designed on a printed circuit board with components like a microcontroller and ZigBee transceiver. Sensors for temperature and humidity were connected to the circuit to monitor the environment wirelessly. The system provides a low-cost way to power remote sensors without needing battery replacement and avoids the high costs of wiring a power source.
1) The document proposes a model for a frequency tunable inverted-F antenna that uses ferrite material.
2) The resonant frequency of the antenna can be significantly shifted from 2.41GHz to 3.15GHz, a 31% shift, by increasing the static magnetic field placed on the ferrite material.
3) Altering the permeability of the ferrite allows tuning of the antenna's resonant frequency without changing the physical dimensions, providing flexibility to operate over a wide frequency range.
This document summarizes a research paper that presents a speech enhancement method using stationary wavelet transform. The method first classifies speech into voiced, unvoiced, and silence regions based on short-time energy. It then applies different thresholding techniques to the wavelet coefficients of each region - modified hard thresholding for voiced speech, semi-soft thresholding for unvoiced speech, and setting coefficients to zero for silence. Experimental results using speech from the TIMIT database corrupted with white Gaussian noise at various SNR levels show improved performance over other popular denoising methods.
This document reviews the design of an energy-optimized wireless sensor node that encrypts data for transmission. It discusses how sensing schemes that group nodes into clusters and transmit aggregated data can reduce energy consumption compared to individual node transmissions. The proposed node design calculates the minimum transmission power needed based on received signal strength and uses a periodic sleep/wake cycle to optimize energy when not sensing or transmitting. It aims to encrypt data at both the node and network level to further optimize energy usage for wireless communication.
This document discusses group consumption modes. It analyzes factors that impact group consumption, including external environmental factors like technological developments enabling new forms of online and offline interactions, as well as internal motivational factors at both the group and individual level. The document then proposes that group consumption modes can be divided into four types based on two dimensions: vertical (group relationship intensity) and horizontal (consumption action period). These four types are instrument-oriented, information-oriented, enjoyment-oriented, and relationship-oriented consumption modes. Finally, the document notes that consumption modes are dynamic and can evolve over time.
The document summarizes a study of different microstrip patch antenna configurations with slotted ground planes. Three antenna designs were proposed and their performance evaluated through simulation: a conventional square patch, an elliptical patch, and a star-shaped patch. All antennas were mounted on an FR4 substrate. The effects of adding different slot patterns to the ground plane on resonance frequency, bandwidth, gain and efficiency were analyzed parametrically. Key findings were that reshaping the patch and adding slots increased bandwidth and shifted resonance frequency. The elliptical and star patches in particular performed better than the conventional design. Three antenna configurations were selected for fabrication and measurement based on the simulations: a conventional patch with a slot under the patch, an elliptical patch with slots
1) The document describes a study conducted to improve call drop rates in a GSM network through RF optimization.
2) Drive testing was performed before and after optimization using TEMS software to record network parameters like RxLevel, RxQuality, and events.
3) Analysis found call drops were occurring due to issues like handover failures between sectors, interference from adjacent channels, and overshooting due to antenna tilt.
4) Corrective actions taken included defining neighbors between sectors, adjusting frequencies to reduce interference, and lowering the mechanical tilt of an antenna.
5) Post-optimization drive testing showed improvements in RxLevel, RxQuality, and a reduction in dropped calls.
This document describes the design of an intelligent autonomous wheeled robot that uses RF transmission for communication. The robot has two modes - automatic mode where it can make its own decisions, and user control mode where a user can control it remotely. It is designed using a microcontroller and can perform tasks like object recognition using computer vision and color detection in MATLAB, as well as wall painting using pneumatic systems. The robot's movement is controlled by DC motors and it uses sensors like ultrasonic sensors and gas sensors to navigate autonomously. RF transmission allows communication between the robot and a remote control unit. The overall aim is to develop a low-cost robotic system for industrial applications like material handling.
This document reviews cryptography techniques to secure the Ad-hoc On-Demand Distance Vector (AODV) routing protocol in mobile ad-hoc networks. It discusses various types of attacks on AODV like impersonation, denial of service, eavesdropping, black hole attacks, wormhole attacks, and Sybil attacks. It then proposes using the RC6 cryptography algorithm to secure AODV by encrypting data packets and detecting and removing malicious nodes launching black hole attacks. Simulation results show that after applying RC6, the packet delivery ratio and throughput of AODV increase while delay decreases, improving the security and performance of the network under attack.
The document describes a proposed modification to the conventional Booth multiplier that aims to increase its speed by applying concepts from Vedic mathematics. Specifically, it utilizes the Urdhva Tiryakbhyam formula to generate all partial products concurrently rather than sequentially. The proposed 8x8 bit multiplier was coded in VHDL, simulated, and found to have a path delay 44.35% lower than a conventional Booth multiplier, demonstrating its potential for higher speed.
This document discusses image deblurring techniques. It begins by introducing image restoration and focusing on image deblurring. It then discusses challenges with image deblurring being an ill-posed problem. It reviews existing approaches to screen image deconvolution including estimating point spread functions and iteratively estimating blur kernels and sharp images. The document also discusses handling spatially variant blur and summarizes the relationship between the proposed method and previous work for different blur types. It proposes using color filters in the aperture to exploit parallax cues for segmentation and blur estimation. Finally, it proposes moving the image sensor circularly during exposure to prevent high frequency attenuation from motion blur.
This document describes modeling an adaptive controller for an aircraft roll control system using PID, fuzzy-PID, and genetic algorithm. It begins by introducing the aircraft roll control system and motivation for developing an adaptive controller to minimize errors from noisy analog sensor signals. It then provides the mathematical model of aircraft roll dynamics and describes modeling the real-time flight control system in MATLAB/Simulink. The document evaluates PID, fuzzy-PID, and PID-GA (genetic algorithm) controllers for aircraft roll control and finds that the PID-GA controller delivers the best performance.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
BREEDING METHODS FOR DISEASE RESISTANCE.pptxRASHMI M G
Plant breeding for disease resistance is a strategy to reduce crop losses caused by disease. Plants have an innate immune system that allows them to recognize pathogens and provide resistance. However, breeding for long-lasting resistance often involves combining multiple resistance genes
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Nucleophilic Addition of carbonyl compounds.pptxSSR02
Nucleophilic addition is the most important reaction of carbonyls. Not just aldehydes and ketones, but also carboxylic acid derivatives in general.
Carbonyls undergo addition reactions with a large range of nucleophiles.
Comparing the relative basicity of the nucleophile and the product is extremely helpful in determining how reversible the addition reaction is. Reactions with Grignards and hydrides are irreversible. Reactions with weak bases like halides and carboxylates generally don’t happen.
Electronic effects (inductive effects, electron donation) have a large impact on reactivity.
Large groups adjacent to the carbonyl will slow the rate of reaction.
Neutral nucleophiles can also add to carbonyls, although their additions are generally slower and more reversible. Acid catalysis is sometimes employed to increase the rate of addition.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
The debris of the ‘last major merger’ is dynamically young
50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis Bacteria
1. IOSR Journal of Applied Physics (IOSR-JAP)
e-ISSN: 2278-4861.Volume 5, Issue 3 (Nov. - Dec. 2013), PP 49-56
www.iosrjournals.org
www.iosrjournals.org 49 | Page
50 Hz Frequency Magnetic Field Effects On Pseudomonas
Aeruginosa And Bacillus Subtilis Bacteria
Mona H. Ibraheim*, Doaa B. El-Din Darwish **
*Department of Physics, Faculty of Science, Zagazig University, Egypt
** Biology Department,University of Tabuk, ,Saudi Arabia
Abstract: The effect of electromagnetic field of different intensities on Pseudomonas aeruginosa (as gram-negative
bacteria) and Bacillus subtilis (as gram-positive bacteria) was investigated to find out the effective magnetic field strength
that alters the running physiological processes of every microorganism. Equal volumes of P. aeruginosa and B. subtilis
suspensions were exposed for one hour at their maximum rate of active growth to the electromagnetic field (2 - 10 mT, 50
Hz). The results indicated that no remarkable differences were found in the growth of exposed P. aeruginosa. Moreover, a
remarkable inhibition in the growth of exposed relative to unexposed B. subtilis cells was achieved at (4 mT) as compared
with other intensities which may indicate that this magnetic field induction had a great effect on the biological activity of the
cells, so more investigations were made at this magnetic field induction. Remarkable changes in the growth characteristics
could be easily detected as the absorbance decreased which indicate a decrease in the cells number and consequently an
inhibition case for the bacteria. Also, the antibiotic sensitivity test of B. subtilis cells indicated either inhibition or
stimulation case for the bacteria depending on the drug mode of action.
Keywords: electromagnetic field, microorganism, Bacillus subtilis , Pseudomonas aeruginosa .
I. Introduction
Lots of studies have been carried out concerning man-made ELF-EMFs effects on biological systems (Balcavage
et al., 1996; Berg, 1999; Panagopoulos et al., 2002) to state safety limits for exposure to these fields especially with
increasing daily use of electric and electronic devices even though many studies on their effects on health.
During the last decade the effects of electromagnetic fields on “smaller” biological objects started to be
investigated. The objects studied were cells (Scarfi et al., 1997; Monti et al., 1991), tissues (Schimmelpfeng and Dertinger,
1993) and living organisms (Hönes, 1998). Recently, bacteria are good experimental subjects to evaluate how such
prokaryote unicellular microorganisms may respond to electromagnetic fields (Markov et al., 2004; Babushkina et al., 2005).
Because of the nature of microorganisms which makes them suitable for use into areas .
Such as basic molecular and cellular biology. They are simpler than plants and animals, both genetically and
biochemically, they reproduce rapidly so that large numbers of organisms, with the same genetic composition, can be easily
grown (Atlas, 1995).
In this field, Segatore et al., (2012) found that the exposure of E. coli and P. aeruginosa to extremely low-
frequency electromagnetic fields (2mT; 50Hz) at 4, 6, and 8 h of incubation the number of cells was significantly decreased
in bacteria exposed to electromagnetic field when compared with the control. Additionally, at 24 h of incubation, the
percentage of cells increased (P. aeruginosa ∼ 42%; E. coli ∼ 5%) in treated groups with respect to control groups
suggesting a progressive adaptive response. By contrast, no remarkable differences were found in the antibiotic susceptibility
and on the growth rate of both bacteria comparing exposed groups with control groups.
Taqavi et al., (2012) found that the effect of low frequency (10 Hz with an intensity of 700 milli gauss) on E. coli
showed, a significant decrease in the number of exposed cells (CFU / ml). The results of biochemical tests also showed
negative effects of electromagnetic fields on the biochemical properties of E. coli.
Inhan-Garip et al. (2011) investigated the effect of extremely low frequency (<300 Hz) electromagnetic fields
(ELF-EMF) on the growth rate of Gram-positive and Gram-negative bacteria. The results showed a decrease in the growth
rate of exposed samples with respect to control.
Di Campli et al. (2010) investigated the effects of exposure to extremely low-frequency electromagnetic fields
(ELF-EMF) both on biofilm formation and on mature biofilm of Helicobacter pylori. The ELF-EMF acted on the bacterial
population during the biofilm formation displaying significant differences in cell viability. whereas, on mature biofilm, no
significant differences were found when compared to the controls.
In this work we used Pseudomonas aeruginosa (gram-negative bacteria) and Bacillus subtilis (gram-positive
bacteria) as experimental models for our studies. Our choice to these bacterial strains was supported by the fact that these
bacteria are within easy reach, short life cycle (Nakasono and Saiki, 2000) and can grow at 37 ° C. The effect of
electromagnetic field (2 - 10 mT, 50 Hz) was investigated on these strains to find out the effective magnetic field strength
that alters the running physiological processes of every microorganism.
II. Materials and Methods
Samples and tested organisms
Subcultures of P. aeruginosa and B. subtilis originally from cultures maintained at the microbiology laboratory
were used during this investigation. All bacterial strains were cultivated over night on nutrient broth at 37 o
C. Inoculums of
these strains were used to inoculate nutrient agar plates and incubated at 37 o
C till used.
2. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 50 | Page
Preparation of the bacterial cultures for exposure:
Bacterial cells were inoculated to sterilized nutrient broth in screw capped test tubes filled to 2/3 of their total volume
and incubated overnight at 37 o
C.
The bacterial cells were cultivated in 500 ml screw capped flasks containing 150 ml of sterilized nutrient broth.
The cultures were incubated at 37 o
C and allowed to grow.
Each culture obtained was divided under sterile conditions into two groups, one exposed to ELF-EMF and the other
remained as control.
The part of the culture to be exposed is sub-divided into three aliquots. These aliquots will be exposed simultaneously
to the same field characteristics and used as replicates in each experiment.
Magnetic field exposure facility
A homogenous magnetic field generated by a solenoid consisting of 320 turns from electrically insulated 2 mm
cupper wire wound in a homogenous way around a cupper cylinder 2 mm thick, 5 cm diameter and 10 cm length. The
temperature during the exposure period was 37 o
C; it was controlled using air conditioner. The Tubes of the exposed
bacteria were putted in the middle of the coil by using supports to get a homogenous and higher magnetic field strength. The
ends of the solenoid were connected to variac fed from the mains (220 V, 50 Hz), as shown in figure (1a).
The magnetic field intensity was measured by means of hand held Gauss/Tesla meter, as the result proved its
homogeneity among all the volume and was within ± 5% at the ends. The magnetic flux density was varied, as the field
strength was adjusted by changing the current through the coil. The magnetic field exposure system was manufactured
locally, in the faculty of Science Mansoura University.
Equal volumes of the bacterial strains were exposed for an hour at their mid-to-late exponential phase (maximum
rate of active growth) to the magnetic field at different intensities in the range of (2 - 10 mT) to specify the most effective
magnetic field intensity on the organisms. Then, the organisms were exposed for an hour at (2, 4, 6 …24) hr at this magnetic
field intensity, after exposure; part of the sample was used to evaluate the direct effect and the rest was incubated at 37 o
C
for an hour to study the recovery of the magnetic field. The unexposed bacterial cells were put in similar conditions, but
without magnetic field.
Fig. (1a): The electromagnetic field exposure system.
Fig. (1b): A diagram of the solenoid characteristics.
Measurement of the bacterial growth
Count-Absorbance calibration curve (survival curve)
To study the bacterial growth, standard survival curves were plotted between the absorbance of the samples (unexposed
cells) at 600 nm and the concentration of cells (number of cells / ml). Spectro SC LaboMed, Inc. was used for absorbance
measurements. For cell counting the plate count technique was used (Stainer et al., 1986).
3. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 51 | Page
III. Method:
Appropriate dilutions of the bacterial cells were used to inoculate nutrient agar plates.
Inoculated plates then incubated at 37 o
C for 24 hr.
By counting the number of colonies developed after incubation and multiplying it with the dilution factor, the number
of cells in the initial population is determined.
Growth characteristics of exposed and unexposed cells
Equal volumes from every bacterial strain were incubated for 24 hr. These strains exposed at different periods, the
first volume exposed after two hours of incubation, the second volume exposed after four hours, the third volume exposed
after six hours and so on until 24 hr. For each exposure volume there was a corresponding control volume.The absorbance of
each volume was measured.
Growth rate
The growth rates of the selected volumes (direct and late effect) were studied through measuring the absorbance at
wavelength 600 nm of the viable cells after (2, 4 and 6…… 24 hr) and then plotted as a function of time.
Method:
By using a sterilized platinum loop, bacterial cells (either control or exposed) from selected volumes were inoculated
into sterilized 500 ml screw-capped flasks containing 150 ml sterilized nutrient broth.
The cultures are incubated at 37 o
C, but the incubation was interrupted each two hours for about 1 min, as a sample is
taken for absorbance measurements (each reading was taken three times and the average was taken).
The absorbance of the cultures then plotted as a function of the incubation time.
Antibiotic sensitivity test
Selected isolates of pathogenic bacteria were subjected sensitivity testing using 5 different antimicrobial agents,
which represents susceptibility breakpoint for all antimicrobial agents used in the antibacterial sensitivity testing.
Discs as well as zone reading chart were supplied by BBL™. The sensitivity tests were carried twice for each
microorganism, before and after exposure to magnetic fields. Antimicrobial sensitivity tests were carried out and performed
by the procedure outlined by the National Committee for (Clinical Laboratory standards, 1984).
The sensitivity test was done using Iso-Sensitest agar (Oxide), this medium is used primarily for the antimicrobial
disc-agar diffusion procedure, the so-called disc method, which is one of the most useful and widely used tests for
antimicrobial susceptibility of microorganisms.
In this work the antibiotic sensitivity test was made as a comparative study between unexposed bacterial cells and
the exposed ones, and nutrient agar was used as culture medium. The antibiotics used in this study were chosen to be with
different modes of action, and they were: Amikacin, 30 µm, Rifampin, 5 µm, Norfloxacin, 10 µm, Ceftriaxone, 30 µm and
Rifampin, 5 µm.
The method used to measure the sensitivity of the bacterial cells toward different antibiotics was disc method by
Bauru-Kirby technique (Baker et al., 1980). The diameters of the inhibition or stimulation zone were measured after 24 hr.
Method:
Using 150 × 15 mm plates, about 60 ml of sterile molten nutrient agar was poured into each plate. To give a uniform
agar layer of depth 4 mm.
The plates were allowed to dry at 37 o
C for 30 min.
Using sterile cotton-wool swab, the micro-organisms were equally distributed over the agar surface.
As soon as possible and not later than 15 min after the inoculation of plates, the antibiotic disks were applied in order
that diffusion and growth proceed simultaneously. Disks were arranged at least 15 mm from the edge of the plate and
20 mm apart of each other.
The plates were incubated at 37 o
C for 24 hr.
The diameter of each zone of inhibition was then measured to the nearest mm using ruler stick.
Statistical evaluation
The statistical analysis of the biological data was used according to (Harnet, 1994) by calculating arithmetic means and
standard deviations for dielectric measurements. The average readings of 5 runs were used.
IV. Results
P. aeruginosa studies
Survival curve:
Fig. (2) illustrates the variation of the sample absorbance measured at 600 nm as a function of the number of
microorganisms in cfu / ml (N). The plot shows a linear dependence of the absorbance on the number of microorganisms in
count / ml. By using this relation we can calculate the number of microorganisms / ml from the measured value of its
absorbance (A).
The linear dependence can be easily represented by the relation;
N = 5 × 10 12
A (1)
4. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 52 | Page
Fig. (2): Calibration curve between the number of P. aeruginosa cells / ml and absorbance at 600 nm.
Growth curve characteristics for unexposed P. aeruginosa sample
Fig. (3) illustrates the changes in the absorbance of the bacterial suspension as a function of incubation time for 24 hr. It
is clear from the figure that the lag phase ended after two hours followed by exponential growth period ended after 14 hr.
and followed by the stationary phase.
Fig. (3): Growth curve characteristics for unexposed P. aeruginosa.
Effects of ELF electromagnetic field on P. aeruginosa cells
Fig. (4a) shows a histogram for the absorbance at 600 nm of the bacterial samples after being exposed at their
maximum rate of active growth, after (10 hrs) of incubation, to (50 Hz) electromagnetic field of different intensities in the
range of (2 - 10 mT) for one hour relative to their control.
Fig. (4b) shows a histogram for the absorbance at 600 nm of the bacterial samples one hour after being exposed at
their maximum rate of active growth after (10 hrs) of incubation to (50 Hz) electromagnetic field of different intensities in
the range of (2 - 10 mT) for one hour relative to their control.
The results indicated that there were convergent results for both exposed and recovery study as compared with
unexposed. This may indicate that none of the used magnetic field inductions (2 - 10 mT) has an obvious effect on the
growth of P. aeruginosa. Therefore, the experiment had been stopped at this stage of findings.
Fig. (4a): Effect of exposure to electromagnetic field of different intensities on the growth of P. aeruginosa.
0
0.2
0.4
0.6
0.8
1
1.2
0 2 4 6 8 10 12
Absorbanceat600nm
N × 10 -12 (cfu / ml)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10 12 14 16 18 20 22 24
Absorbanceat600
nm
Time (hr)
0
0.1
0.2
0.3
0.4
0.5
2 4 6 8 10
Absorbanceat600nm
Magnetic field intensity (mT)
Unexposed
Exposed
5. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 53 | Page
Fig. (4b): Effect of exposure to electromagnetic field of different intensities on the growth of P. aeruginosa one hour after
exposure.
Effects on the growth characteristics curve of P. aeruginosa bacteria
Fig. (5) illustrates the changes in the absorbance at 600 nm of the bacterial suspensions as a function of the incubation
after being exposed to the electromagnetic field (4 mT - 50 Hz) for one hour relative to their control.
It is clear from the figure that the growth of the microorganism had not been differ broudly from exposed samples,
which indicated that the irradiation of the samples with electromagnetic fields caused very week effect on the growth of P.
aeruginosa bacteria.
Fig. (5): Growth curve characteristics for unexposed P. aeruginosa cell.
Effects on the antimicrobial sensitivity
Table (1) illustrates the antibiotic sensitivity of P. aeruginosa cells after exposure to electromagnetic field as
compared with unexposed at the periods of (14 hr). The antibiotics used have different modes of action on the
microorganism.
It is clear from the table that there was a little decrease in the sensitivity of exposed cells to the antibiotics
Amikacin, Ceftriaxone, Norfloxacin, Rifampin and Ciprofloxacin as revealed in the increase of the zone diameter of the
microorganism. These results indicate that the viability of cells exposed at (14 hr) decreased as compared with the
unexposed cells as an inhibition case.
All these results indicate that there are small effects of the used electromagnetic field to drug mode of action on
bacterial cell.
Table (1)
The antibiotic sensitivity of P. aeruginosa cells after exposure to electromagnetic field as compared with unexposed at the
period of (14 hr).
Antibiotic Disc
content
(µg)
Inhibition zone diameter in (cm)
Mode of action Unexposed Exposed (14 hr)
Amikacin
(AN) 30
Inhibition of protein
synthesis 1.5 1.5
Ceftriaxone (CRO)
30
Inhibition of cell wall
synthesis 2 1.9
Norfloxacin (NOR)
10
Inhibition of DNA
respiration 2.9 2.8
Rifampin
(RA) 5
Inhibition of RNA
transcription 1.1 0.9
Ciprofloxacin
(CIP) 5
Inhibition of DNA
synthesis 1.5 1.4
0
0.5
2 4 6 8 10
Absorbanceat600nm
Magnetic field intensity (mT)
Unexposed
Recovery
study
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10 12 14 16 18 20 22 24
Absorbanceat600nm
Time (hr)
Unexposed
Exposed
Recovery study
6. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 54 | Page
B. subtilis studies
Survival curve
Fig. (6) illustrates the variation of the sample absorbance measured at 600 nm as a function of the number of
microorganisms in cfu / ml (N). The plot shows a linear dependence of the absorbance on the number of microorganisms in
count / ml. By using this relation we can calculate the number of microorganisms / ml from the measured value of its
absorbance (A).
The linear dependence can be easily represented by the relation;
N = 14 × 10 8
A (2)
Fig. (6): Calibration curve between the number of B. subtilis cells / ml and absorbance at 600 nm.
Growth curve characteristics for unexposed B. subtilis sample
Fig. (7) illustrates the changes in the absorbance of the bacterial suspension as a function of incubation time for 24 hr. It
is clear from the figure that the lag phase ended after two hours followed by exponential growth period ended after 14 hr and
followed by the stationary phase.
Fig. (7): Growth curve characteristics for unexposed B. subtilis.
Effects of ELF electromagnetic field on B. subtilis cells
Fig. (8a) shows a histogram for the absorbance at 600 nm of the bacterial samples after being exposed at their
maximum rate of active growth, after (10 hrs) of incubation, to (50 Hz) electromagnetic field of different intensities in the
range of (2 - 10 mT) for one hour relative to their control.
Fig. (8b) shows a histogram for the absorbance at 600 nm of the bacterial samples one hour after being exposed at their
maximum rate of active growth after (10 hrs) of incubation to (50 Hz) electromagnetic field of different intensities in the
range of (2- 10 mT) for one hour relative to their control.
0
0.2
0.4
0.6
0.8
1
0 2 4 6 8 10 12
Absorbanceat600nm
N × 10 -8 (cfu / ml)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 2 4 6 8 10 12 14 16 18 20 22 24
Absorbanceat600
nm
Time (hr)
7. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 55 | Page
Fig. (8a): Effect of exposure to electromagnetic field of different intensities on the growth of B. subtilis.
Fig. (8b): Effect of exposure to electromagnetic field of different intensities on the growth of B. subtilis one hour after
exposure.
The results indicated that the maximum inhibition in growth was for samples exposed at (4 mT) for both exposed and
recovery study as compared with unexposed. Therefore the further studies were concerned only with this magnetic field
induction effects.
Effects on the growth characteristics curve of the B. subtilis bacteria
Fig. (9) illustrates the changes in the absorbance at 600 nm of the bacterial suspensions as a function of the incubation
after being exposed to the electromagnetic field (4 mT - 50 Hz) for one hour relative to their control.
It is clear from the figure and table (2) that the lag phase for the growth of the microorganism had been shifted to
higher values for exposed samples, which indicated that the irradiation of the samples with electromagnetic fields for one
hour caused lately active growth for the microorganism.
Also, the absorbance of the exposed sample decreased and in accordance with equation (2), there is a decrease in the
cells number and consequently an inhibition case for the bacteria.
Moreover, we used the period of 14 hr for investigating the effect of the electromagnetic field (4 mT - 50 Hz) on the
antibiotic sensitivity of B. subtilis cells.
Fig. (9): Growth characteristics curve for B. subtilis after exposure to electromagnetic field as compared with unexposed.
0
0.1
0.2
0.3
0.4
0.5
2 4 6 8 10
Absorbanceat600nm
Magnetic field intensity (mT)
Unexposed
Exposed
0
0.1
0.2
0.3
0.4
0.5
2 4 6 8 10
Absorbanceat600nm
Magnetic field intensity (mT)
Unexposed
Recovery study
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 2 4 6 8 10 12 14 16 18 20 22 24
Absorbanceat600nm
Time (hr)
Unexposed
Exposed
Recovery study
8. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 56 | Page
Table (2)
Growth characteristics of B. subtilis cells before and after
exposure to the electromagnetic field.
Samples Lag
phase
(hrs)
Exponential phase (hrs)
(Active Growth)
Stationary phase (hrs)
(Maximum Growth)
No. of cells / ml at
Stationary phase
Unexposed 1 10 14 10.08 × 10 8
Exposed 4 10 14 7.42 × 10 8
Recovery study 2 4 6 3.43 × 10 8
Effects on the antimicrobial sensitivity
Table (3) illustrates the antibiotic sensitivity of B. subtilis cells after exposure to electromagnetic field as compared with
unexposed at the periods of (14 hr). The antibiotics used have different modes of action on the microorganism.
Table (3)
The antibiotic sensitivity of B. subtilis cells after exposure to electromagnetic field as compared with unexposed at the period
of (14 hr).
Antibiotic Disc
content
(µg)
Inhibition zone diameter in (cm)
Mode of action Unexposed Exposed (14 hr)
Amikacin
(AN) 30
Inhibition of protein
synthesis 2 2.7
Ceftriaxone (CRO)
30
Inhibition of cell wall
synthesis 1.6 1.9
Norfloxacin (NOR)
10
Inhibition of DNA
respiration 2.2 1.8
Rifampin
(RA) 5
Inhibition of RNA
transcription 1.4 1.6
Ciprofloxacin
(CIP) 5
Inhibition of DNA
synthesis 1.5 1.1
It is clear from the table that there was a decrease in the sensitivity of exposed cells to the antibiotics Amikacin,
Ceftriaxone and Rifampin as revealed in the increase of the zone diameter of the microorganism. These results indicate that
the viability of cells exposed at (14 hr) decreased as compared with the unexposed cells as an inhibition case. And, also it
illustrates an increase in the sensitivity of exposed cells to Norfloxacin and Ciprofloxacin as revealed in the decrease of zone
diameter of the microorganism of that volume. These results indicated that the exposed cells at (14 hr) became more resistant
to these antibiotics, as a stimulation case.
All these results indicate that there are effects of the used electromagnetic field to drug mode of action on bacterial cell
through inhibition of protein synthesis, cell wall synthesis, RNA transcription and DNA respiration and synthesis.
V. Discussion
From the data concerning the effects of ELF-EMF on P. aeruginosa convergent results for exposed samples
relative to unexposed as shown in figures (4.1 a &b). This may indicate that none of the used magnetic field inductions (2 -
10 mT) has an obvious effect on the growth of P. aeruginosa. Therefore, the experiments had been stopped at this stage of
findings.
These results could be explained according to the fact that P. aeruginosa known to enter into a dormant state
referred to as the “Viable But Non Culturable state” (VBNC) as well as to form biofilm, constituted of sessile aggregated
cells embedded in a matrix in which cells organize themselves into microbial communities establishing a sort of “free
multicellularity” (Donlan and Costerton, 2002; Oliver, 2005), to adapt themselves against stress induced by the exposure to
ELF-EMF.
It is worthy to mention here that the solenoid available in our laboratory could generate magnetic flux density of
maximum (10 mT) that intensities exceed this value would be accompanied with a large amount of heat that could affect on
our results. Therefore, it was not possible to study the effect of higher intensities on the microorganisms.
From the data concerning the effects of ELF-EMF on B. subtilis a remarkable inhibition in the growth of exposed
relative to unexposed cells was achieved at electromagnetic field of (50 Hz – 4 mT) as compared with other intensities, as
shown in figures (4.2a & b), which may indicate that this magnetic field induction had a great effect on the biological
activity of the cells.
In addition, remarkable changes in the growth characteristics could be easily detected as the absorbance decreased
which indicate a decrease in the cells number and consequently an inhibition case for the bacteria.
Also, the antibiotic sensitivity test of B. subtilis cells indicated that the used electromagnetic field could cause
either a decrease or an increase in the sensitivity of exposed cells resulted in either inhibition or stimulation case for the
bacteria depending on the drug mode of action on the bacterial cell.
All the results of the recovery study indicated that the studied microorganisms could switch on new pathways to adapt
themselves against stress induced by exposure to EMFs aimed at their preservation (Bjedov et al., 2003) as the transposition
which represents an important source of genetic variability can be induced (Lamrani et al., 1999; Del Re et al., 2004). In
9. 50 Hz Frequency Magnetic Field Effects On Pseudomonas Aeruginosa And Bacillus Subtilis
www.iosrjournals.org 57 | Page
this manner, bacteria try to find their adaptation through intra-strains variability as the benefits of heterogeneity among a cell
population enhances the persistence of bacteria (Avery, 2005).
VI. Conclusion
It could be concluded from the present work that:-
The effects of exposure to extremely low frequency electromagnetic fields depend on the magnetic field intensity,
frequency and the period of exposure.
The interference of the applied electromagnetic field with the bioelectrical signals generated during the physiological
processes may affect the biological functions causing either enhancement or inhibition of the running processes.
Each organism responds to the exposure to ELF-EMF in a specific manner depending on the adaptation mechanism of
each organism.
The exposure to ELF-EMFs may have beneficial effects as well as harmful effects, that the safety limits for exposure to
these fields are field strength and frequency dependent.
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