Hi there,
This was topic on which I presented a talk in our department. As we know Insecticide such as pyrethroids are being most widely used for controlling insect pest in agriculture because of their safe, cheap, effective and long-lasting nature (Bulter et al. 2011). However, the widespread development of insecticide resistance, especially resistance to pyrethroid and the fact that resistance to an insecticide generally confers cross-resistance to other insecticides has become a serious problem challenging the control of agriculturally, economically, and medically important insect pests and resulting in increase of insect vector-borne diseases in many parts of the world (Zaim 2002; Bulter 2011). Three major mechanisms are involved in insecticide resistance: (1) increased metabolic detoxification of insecticides; (2) decreased sensitivity of the target proteins on which an insecticide acts, known as target site insensitivity; and (3) decreased cuticular penetration/or increased sequestration/storage.
Bacillus thuringiensis(Bt)Cry protein is one of the most effective biopesticides that can act against a large group of insect orders like Lepidoptera, Coleoptera, Diptera etc. But through the course of evolution insects have developed resistance so that they can combat against Bt. Mutation(s) in the target site; reduced protease activity; sequestration of toxin molecules; mutations in the ABCC2 transporter protein are few mechanisms which govern resistance in insects against Cry protein. Therefore, it has become prime importance to understand the molecular basis of insect resistance and what could be the strategies by which the efficacy of the Cry protein can be enhanced. The strategies for improving the efficacy of Cry toxin are (i) Expression of chitinase gene along with Cry toxins; (ii) Expression of hybrid toxin; (iii) Introduction of intramolecular cleavage sites. The insects have developed resistance against different groups of Cry proteins such as Cry2Aa, Cry1Ac, Cry2Ab etc. But the relative fitness (such as larval and pupal weight, pupal duration, and survival rate, etc.) in resistant larvae is much lower than the susceptible larvae because of genetic changes in insects. One of such genes that affects the relative fitness in Helicoverpa armigera is death associated LIM only protein (Ha-DALP) which is basically involved in cell signalling, cell fate determination, transcriptional regulation of gene expression etc.
Here I would like to inform you in host selection process by the parasitiods.I hope It would increase your understanding on the steps involved n the host selection process.............................
Here I would like to inform you in host selection process by the parasitiods.I hope It would increase your understanding on the steps involved n the host selection process.............................
the repeated use of the same chemical which has the same mode of action that leads to the loss of insect sensitivity and also heritable change would occur in the genome nothing but resistance that means the population not able to control with the normal dose need to develop resistant management strategies
Content:
Introduction
Importance of Host Plant Resistance
Historical perspectives
Advantages and Disadvantages of HPR
Mechanisms of Resistance
Adaptation of Resistance in Plant to Insect
Morphological
Anatomical
Biochemical
Assembly of plant species - Gene Pool
Behavior in Relation to Host Plant Factor
the repeated use of the same chemical which has the same mode of action that leads to the loss of insect sensitivity and also heritable change would occur in the genome nothing but resistance that means the population not able to control with the normal dose need to develop resistant management strategies
Content:
Introduction
Importance of Host Plant Resistance
Historical perspectives
Advantages and Disadvantages of HPR
Mechanisms of Resistance
Adaptation of Resistance in Plant to Insect
Morphological
Anatomical
Biochemical
Assembly of plant species - Gene Pool
Behavior in Relation to Host Plant Factor
Dr. Cyril Gay - Overview of Alternatives to Antibiotics in AgricultureJohn Blue
Overview of Alternatives to Antibiotics in Agriculture - Dr. Cyril Gay, USDA, ARS, from the 2012 NIAA One Health Approach to Antimicrobial Resistance and Use Symposium, October 26-27, 2012, Columbus, OH, USA.
More presentations at:
http://www.trufflemedia.com/agmedia/conference/2012-one-health-to-approach-antimicrobial-resistance-and-use
History
Host pathogen interaction
R gene
Molecular techniques for detection of plant pathogens
Role of molecular techniques in resistance breeding Deployment of R genes and linked markers
Transgenic approaches in plant protection
Conclusion
Plant disease resistance genes: current status and future directions.RonikaThakur
Agriculture plays a key role to ensure the food security. But plant diseases hinder the crop production by reducing yield to much extent. To overcome this problem it is crucial to understand plant disease resistance genes which prevent growth of plant pathogens thereby reducing the yield loss.
A transgenic crop plant contains a gene or genes which have been artificially inserted, instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: for example, transgenic Bt corn, which produces its own insecticide, contains a gene from a bacterium. Plants containing transgenes are often called genetically modified or GM crops.
What is the need of transgenic plants?
A plant breeder tries to assemble a combination of genes in a crop plant which will make it as useful and productive as possible. The desirable genes may provide features such as higher yield or improved quality, pest or disease resistance, or tolerance to heat, cold and drought. This powerful tool enables plant breeders to do what they have always done - generate more useful and productive crop varieties containing new combinations of genes - but this approach expands the possibilities beyond the limitations imposed by traditional cross pollination and selection techniques.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
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/
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
PRESENTATION ABOUT PRINCIPLE OF COSMATIC EVALUATION
Molecular basis of insecticides resistance in insects with special reference to Bacillus thuringiensis
1. Molecular basis of insecticide
resistance with special reference to
Bacillus thuringiensis
Presented by-Deba Jit Das
PhD 3rd
year, 1st
semester
2. What does insecticide resistance mean?
Mechanism of development of resistance
Resistance against Bacillus thuringiensis
Strategies to delay resistance development against Bt
Genetic regulation of relative fitness in Cry1Ac resistant Helicoverpa
armigera larvae
Points to be discussed..
3. The decreased susceptibility of a pest population to
a pesticide that was previously effective at controlling
the pest
Or
The genetically acquired ability of an organism to
survive a pesticide application at doses that once
killed most individuals of the same species
What is insecticide resistance??
4. Phase I- Due to selection of variants in the population
according to genetic principle, the resistance which is
initially present in the population is expressed.
Phase II- Acceleration of resistance takes place by
induction of pre-existing detoxifying enzymes towards
enhanced activity, resulting in faster breakdown of the
chemicals.
Two phases of resistance
7. Development of ability to avoid a dose that would prove
lethal.
Stimulus dependent and matter of hypersensitivity or
hyperirritability
Avoid lethal dose or treated surface
Behavioural resistance??
9. Cuticle contains more protein and Lipid.
Increased sclerotization.
Binding protein and lipid reservoir traps
insecticide in the cuticle.
Slight resistance.
What is reduced penetrance??
13. Detoxifying Enzymes
a. Hydrolases –Carboxyl Esterase (CarE)
i. Esterase gene amplification
ii. Esterase mutation
b. Mixed fuction oxidases (MFO’s)
Cytochrome P450 monoxygenases (P450)
c. Glutathion-S-transferases (GST)
What are the different detoxifying enzymes??
16. Bacillus thuringiensis
Bacillus thuringiensis (Bt ) is a common gram positive,
spore-forming, soil bacterium.
In stress condition Bt undergo sporulation and synthesize
insecticidal crystal proteins (ICPs) or Cry proteins.
Benefits of Bt proteins
High specificity and potency,
Reduction in chemical pesticide applications
Increased crop yield.
18. Mechanisms of resistance against Cry protein..
Four major mechanisms of resistance of insects against
Bt toxins are
Alteration in protease activity
Sequestration of the toxin by glycolipid moieties
Alteration in cry toxin receptor
Alteration in ABCC2 transporter
20. How does mutated ABCC2 transporter induce
resistance in insects??
21. How can the toxicity of cry protein be enhanced??
Chitinase improves accessibility of the toxin to the epithelial
membrane.
Serine protease inhibitors reduce degradation of Cry or of
toxin-receptors.
Introduction of intramolecular cleavage sites
Expression of hybrid toxin
Deletion of helix -1 that induces toxin-oligomerization andα
skip cadherin interaction.
24. Genetic regulation of relative
fitness in Cry1Ac resistant
Helicoverpa armigera larvae
25. Up-regulated death associated LIM-only protein
contributes to fitness costs of Bacillus thuringiensis
Cry1Ac resistance in Helicoverpa armigera
Huiming Guo , Guoqing Lu , Xiaofeng Su , Gemei Liang , Chenxi Liu ,
Hongmei Cheng (2014)
26. Enhanced detoxificationBrief overview of the study….
cDNA-AFLP analysis was used to identify differentially
related gene both in susceptible and resistant insects
Ha-DALP gene was differentially expressed in resistant
Helicoverpa larvae
Ha-DALP gene is associated with transcriptioanal
regulation, cell signalling and cell fate determination
27. Enhanced detoxificationObjective of the study….
To analyze the expression pattern of Ha-DALP
gene in both Cry1Ac resistant (BtR) and
susceptible (96S) insects
To compare the fitness-trade off between two
groups of insects
28. Enhanced detoxificationExperimental procedures and findings
Two strains of H.armigera were used for the study
purpose
Cry1Ac resistant Bt strain (BtR)
Cry1Ac susceptible strain (96S)
Resistant insects were selected from the susceptible
strain reared for 75 generations in the presence of
Cry1Ac protoxin
29. Enhanced detoxificationRNA extraction and cDNA cloning
RNA was extracted from different stages (2nd
, 3rd
,4th,
and
5th
instar) and tissues (epidermis, midgut and whole body)
RACE was performed to obtain the full lenth sequence of
HaDALP gene
Sequence comparison with Menduca sexta HaDALP gene
31. Ha-DALP gene expression at
different stage of larval
growth and in different
tissues was checked by qRT-
PCR.
96S and Bt-R Ha-DALP expression analysis
32. FISH was carried out to determine specific expression of Ha-DALP gene in different stages and tissues
of 96s and Bt-R insects.
Analysis of Ha-DALP expression by FISH
FISH analysis of HaDALP transcription levels in the 96S 2nd
instar larvae
FISH analysis of HaDALP transcription levels in the Bt-R 2nd
instar larvae
33. To express Ha-DALP specific dsRNA a recombinant
plasmid (RNAi-DALP) was constructed
Primers were designed to to amplify a 423 bp fragment
from Ha-DALP gene
RNAi-DALP plasmid was transformed into competent
HT115 cells
Bacteria containing Ha-DALP specific dsRNA were
harvested and used for H. armigera feeding bioassay
RNAi analysis in 96S larvae
36. Purified Ha-DALP protein feeding bioassay
Recombinant expression vector pET32a-HaDALP was
constructed using primers designed from Ha-DALP gene
sequence
HaDALP protein was isolated and purified by affinity
purification
Purified HaDALP protein used for feeding the
38. Conclusion of the discussion
To overcome the selection pressure a large group insects has
developed resistance against insecticides as well as Bt
But there is enough score for us to enhance the efficacy of Cry toxin
Genetic change in insects resulting in Bt resistance can also affect
their fitness