This document describes a statistical model for determining the average rate of HIV replication in blood plasma using a truncated logistic distribution. The model proposes that infected cells undergo a truncated logistic distribution in their replication of HIV. Three simulation approaches are used to implement the model: conditional distribution, truncated population mean, and sample mean. The simulation results provide insights into HIV replication dynamics at the cellular level and how the model can be used for further studies of intracellular HIV replication and transmission dynamics.
This document discusses the evolution of HIV and resistance to treatment over time. It explains that HIV has a high mutation rate which allows it to quickly evolve resistance to individual drugs. While highly active antiretroviral therapy (HAART) was able to suppress viral loads, it did not reduce them to zero, allowing HIV to rebound once treatment is stopped. This ongoing ability of HIV to evolve resistance presents ethical challenges and ensures that a cure will not be easily achieved.
1. The document discusses various studies on HIV and AIDS. It examines how PCR techniques can detect HIV even in asymptomatic patients, and how HIV replicates poorly in macaque models due to species-specific differences in CD4 receptors and co-factors.
2. Accidental needlestick infections and transmission from dentists to patients are discussed as examples of HIV transmission. The depletion of CD4+ T-cells during clinical latency is also summarized, as HIV production outstrips the immune system's ability to replace cells.
3. The latency period allows the immune system to be depleted enough for opportunistic infections to take hold, as HIV remains latent in memory T-cells. Variability in clinical latency depends on viral mutations
This document describes a thesis submitted by Jeffrey Hunter to Oregon Health & Science University examining gene expression variations associated with influenza infection severity in humans and mice. The thesis aims to integrate data from human influenza infection datasets, mouse phenotype ontologies, and gene expression data from the Collaborative Cross mouse model to identify conserved genes and pathways related to infection severity across species. Chapter 1 introduces influenza viruses and symptoms, the Collaborative Cross mouse model, and the use of ontologies. The materials and methods used for human differential expression analysis, mouse phenotype analysis, and cross-species integration are described in Chapter 2. Results are presented in Chapter 3, with discussion following in Chapter 4.
This document summarizes a study that explored immune cellular parameters in subjects co-infected with HIV-1 and Mycobacterium leprae (the bacteria that causes leprosy). The study compared four groups: healthy controls, subjects with HIV-1 and M. leprae co-infection, subjects with HIV-1 mono-infection, and subjects with M. leprae mono-infection. Peripheral blood mononuclear cells were analyzed using flow cytometry to evaluate T cell subsets, dendritic cell phenotypes, and IL-4 expression by T cells. The co-infected group showed lower CD4:CD8 ratios, higher levels of activated CD8+ T cells, increased ratios of Vd1:V
The document discusses microbiology and infectious diseases. It provides an overview of key concepts including the host-agent-environment model of infection, types of host defenses, the hierarchy of microbes from smallest to largest, how microbes are distributed, and the world from a microbe's perspective of surviving and multiplying. It also summarizes common ways of clinically categorizing microbes, stages of infectious disease, criteria for diagnosing infection, bacterial structures, and mechanisms of pathogenesis including virulence factors and toxins.
This review article summarizes changes in the antiviral susceptibility of human and avian influenza viruses over the past decade from 2004-2013. It discusses how widespread adamantane resistance developed in circulating influenza viruses, rendering those drugs ineffective and resulting in reliance on the neuraminidase inhibitor oseltamivir. However, emergence of oseltamivir-resistant seasonal H1N1 viruses in 2008 showed that resistance to these drugs could also emerge and spread globally. The review describes the classes of antiviral drugs that have been available and how susceptibility has changed. It aims to understand how resistant strains may emerge in the future.
The role of treatment and counseling in an HIV/AIDS, Malaria and Tuberculosis...iosrjce
HIV/AIDS remains one of the leading causes of death in the world with its effects most devastating in
Sub Saharan Africa due to its dual infection with opportunistic infections especially malaria and tuberculosis.
This study presents a co infection deterministic model defined by a system of ordinary differential equations for
HIV/AIDS, malaria and tuberculosis. The HIV/AIDS malaria co infection sub model is analyzed to determine
the conditions for the stability of the equilibria points and assess the role of treatment and counseling in
controlling the spread of the infections. This study shows that treatment of malaria a lone even in the absence of
HIV/AIDS, may not eliminate malaria from the community therefore strategies for the reduction of malaria
infections in humans should not only target malaria treatment but also the reduction of mosquito biting rate.
The study showed that counseling is the most sensitive parameter in the spread of HIV/AIDS - malaria co
infections, therefore effective counseling strategy is very useful in controlling the spread of the HIV/AIDS and
malaria co infections. The study further showed that ARV treatment and counseling for HIV/AIDS infectives
have no effect on the spread of malaria. Finally the HIV/AIDS malaria model undergoes backward bifurcation
which is favoured by the occurrence of high mosquito biting rate.
This document discusses HIV-exposed seronegative individuals (HESNs) who remain uninfected despite repeated exposure to HIV-1. It explores both genetic and immunological factors that may contribute to their resistance. Genetically, variants of the CCR5 gene that prevent HIV from binding to immune cells, like CCR5-Δ32 in Caucasians and a G316A substitution in Southeast Asians, are common in HESNs. Immunologically, HESNs exhibit elevated expression of interferon-α which inhibits HIV replication, and their adaptive immune response is characterized by regulatory T cells and low inflammation, limiting HIV target cells. Studying these natural protection mechanisms could help develop new prevention strategies.
This document discusses the evolution of HIV and resistance to treatment over time. It explains that HIV has a high mutation rate which allows it to quickly evolve resistance to individual drugs. While highly active antiretroviral therapy (HAART) was able to suppress viral loads, it did not reduce them to zero, allowing HIV to rebound once treatment is stopped. This ongoing ability of HIV to evolve resistance presents ethical challenges and ensures that a cure will not be easily achieved.
1. The document discusses various studies on HIV and AIDS. It examines how PCR techniques can detect HIV even in asymptomatic patients, and how HIV replicates poorly in macaque models due to species-specific differences in CD4 receptors and co-factors.
2. Accidental needlestick infections and transmission from dentists to patients are discussed as examples of HIV transmission. The depletion of CD4+ T-cells during clinical latency is also summarized, as HIV production outstrips the immune system's ability to replace cells.
3. The latency period allows the immune system to be depleted enough for opportunistic infections to take hold, as HIV remains latent in memory T-cells. Variability in clinical latency depends on viral mutations
This document describes a thesis submitted by Jeffrey Hunter to Oregon Health & Science University examining gene expression variations associated with influenza infection severity in humans and mice. The thesis aims to integrate data from human influenza infection datasets, mouse phenotype ontologies, and gene expression data from the Collaborative Cross mouse model to identify conserved genes and pathways related to infection severity across species. Chapter 1 introduces influenza viruses and symptoms, the Collaborative Cross mouse model, and the use of ontologies. The materials and methods used for human differential expression analysis, mouse phenotype analysis, and cross-species integration are described in Chapter 2. Results are presented in Chapter 3, with discussion following in Chapter 4.
This document summarizes a study that explored immune cellular parameters in subjects co-infected with HIV-1 and Mycobacterium leprae (the bacteria that causes leprosy). The study compared four groups: healthy controls, subjects with HIV-1 and M. leprae co-infection, subjects with HIV-1 mono-infection, and subjects with M. leprae mono-infection. Peripheral blood mononuclear cells were analyzed using flow cytometry to evaluate T cell subsets, dendritic cell phenotypes, and IL-4 expression by T cells. The co-infected group showed lower CD4:CD8 ratios, higher levels of activated CD8+ T cells, increased ratios of Vd1:V
The document discusses microbiology and infectious diseases. It provides an overview of key concepts including the host-agent-environment model of infection, types of host defenses, the hierarchy of microbes from smallest to largest, how microbes are distributed, and the world from a microbe's perspective of surviving and multiplying. It also summarizes common ways of clinically categorizing microbes, stages of infectious disease, criteria for diagnosing infection, bacterial structures, and mechanisms of pathogenesis including virulence factors and toxins.
This review article summarizes changes in the antiviral susceptibility of human and avian influenza viruses over the past decade from 2004-2013. It discusses how widespread adamantane resistance developed in circulating influenza viruses, rendering those drugs ineffective and resulting in reliance on the neuraminidase inhibitor oseltamivir. However, emergence of oseltamivir-resistant seasonal H1N1 viruses in 2008 showed that resistance to these drugs could also emerge and spread globally. The review describes the classes of antiviral drugs that have been available and how susceptibility has changed. It aims to understand how resistant strains may emerge in the future.
The role of treatment and counseling in an HIV/AIDS, Malaria and Tuberculosis...iosrjce
HIV/AIDS remains one of the leading causes of death in the world with its effects most devastating in
Sub Saharan Africa due to its dual infection with opportunistic infections especially malaria and tuberculosis.
This study presents a co infection deterministic model defined by a system of ordinary differential equations for
HIV/AIDS, malaria and tuberculosis. The HIV/AIDS malaria co infection sub model is analyzed to determine
the conditions for the stability of the equilibria points and assess the role of treatment and counseling in
controlling the spread of the infections. This study shows that treatment of malaria a lone even in the absence of
HIV/AIDS, may not eliminate malaria from the community therefore strategies for the reduction of malaria
infections in humans should not only target malaria treatment but also the reduction of mosquito biting rate.
The study showed that counseling is the most sensitive parameter in the spread of HIV/AIDS - malaria co
infections, therefore effective counseling strategy is very useful in controlling the spread of the HIV/AIDS and
malaria co infections. The study further showed that ARV treatment and counseling for HIV/AIDS infectives
have no effect on the spread of malaria. Finally the HIV/AIDS malaria model undergoes backward bifurcation
which is favoured by the occurrence of high mosquito biting rate.
This document discusses HIV-exposed seronegative individuals (HESNs) who remain uninfected despite repeated exposure to HIV-1. It explores both genetic and immunological factors that may contribute to their resistance. Genetically, variants of the CCR5 gene that prevent HIV from binding to immune cells, like CCR5-Δ32 in Caucasians and a G316A substitution in Southeast Asians, are common in HESNs. Immunologically, HESNs exhibit elevated expression of interferon-α which inhibits HIV replication, and their adaptive immune response is characterized by regulatory T cells and low inflammation, limiting HIV target cells. Studying these natural protection mechanisms could help develop new prevention strategies.
This document discusses emerging and re-emerging infectious diseases. It begins with trends in infectious diseases, then defines emerging and re-emerging diseases. Factors that contribute to emergence include changes in the agent, host, and environment. Examples are provided of diseases that have emerged or re-emerged recently, including SARS, avian influenza, hepatitis C, and antibiotic resistance. The response from public health is also mentioned.
The document discusses the threat of pandemic influenza and the need for healthcare systems to prepare for disease outbreaks. It notes that recent outbreaks of avian influenza A(H5N1) are a reminder that a human pandemic could occur at any time, causing major suffering and economic losses. Past pandemics like the 1918 Spanish flu prompted authorities to plan for preparedness, but structured planning is still lacking in many healthcare systems. The ability of influenza viruses to mutate and reassort means a new pandemic strain could emerge.
This document describes a mathematical model of hepatitis B virus (HBV) transmission applied to the New Zealand Tongan population. The model predicts that with current infant vaccination coverage of 53%, chronic HBV prevalence will plateau at 2% over 250 years. However, 73% vaccination coverage is needed to eliminate HBV long-term. Improving coverage to 85% through targeted vaccination could arrest transmission within a generation and eliminate HBV, similar to outcomes in Taiwan and Alaska with similar policies. Screening and disease management may also help reduce the HBV burden, though its precise impact is hard to quantify. Mathematical models can help evaluate different control strategies for high prevalence populations.
1.SANITATION VS VACCINATION- The History of Infectious DiseasesAntonio Bernard
The document discusses the origins of many infectious diseases in humans. It notes that 60% of human infectious diseases originated in animals, and that diseases emerged as early humans increasingly domesticated animals like cows, pigs, chickens, and camels. Close contact between humans and domesticated, disease-carrying animals allowed pathogens to jump species. For example, measles likely emerged from cattle viruses, smallpox from camel viruses, influenza from duck viruses, and whooping cough and typhoid from pig bacteria. It was not until the domestication of these animals that humans were exposed to these diseases.
Man Vs Microbe - Pre-Apocalyptic Phase Failed? in IJAHSPreethi Selvaraj
This document discusses the ongoing battle between humans and microbes. It notes the rise of antibiotic-resistant superbugs like MDR-TB that are difficult to treat. Factors contributing to this include overprescription of antibiotics and patient non-compliance. It also discusses the threat of biological warfare, from small-scale food poisoning to mass attacks. Modern techniques allow biological agents to be easily spread through aerosols, contaminated food/water, and more. Stronger regulations on antibiotic usage and policies to defend against bioterrorism are needed to prevent a potential "apocalypse."
Some quick facts and numbers on Coronavirus (COVID-19) Slide Marvels
We pulled together some quick facts on Coronavirus.
Slide Marvels is a leading Presentation Design Company having experience of many years. We are a professional team of presentation designers who have already worked in major consulting firms like McKinsey & Co., Boston Consulting Group and Deloitte to mentioned some of them.
www.slidemarvels.com
The local and global stability of the disease free equilibrium in a co infect...iosrjce
IOSR Journal of Mathematics(IOSR-JM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mathemetics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mathematics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
120 EXPERT Opinions on Coronavirus (COVID-19)- How the Mass Media Exaggerated...Antonio Bernard
This document provides over 120 expert opinions from scientists, doctors, and other professionals criticizing the handling of the coronavirus pandemic. Many experts argue that the virus poses a relatively low risk and that measures like lockdowns and business closures are an overreaction that will cause more harm than the virus itself. Other opinions expressed include that the infection fatality rate is much lower than estimates from the WHO, that social distancing has not been shown to be effective, and that the media coverage has caused unnecessary panic.
Human Noroviruses (HuNoVs) are important enteric pathogens, which affect the stomach and intestines, leading to
gastroenteritis or more commonly called the "stomach flu" or “winter vomiting bug". HuNoVs are mainly transmitted by the fecal-oral
route, either by directly infected person-to-person contact or directly via contaminated foods, water and surface areas. The virus is highly
contagious as 10-100 virus particles are sufficient to cause diseases. HuNoVs can spread easily and cause prolonged outbreaks. This is
due to their environmental persistence, high infectivity, being resistance to disinfection and difficulty in preventing transmission.
HuNoVs are the most common causative agent leading to acute gastroenteritis among infectious diseases worldwide and poses a serious
public health problem, especially among children being the most susceptible. In developing countries, the highest cost of medical care
after respiratory infections is listed for acute gastroenteritis. In this study, Norovirus outbreaks, precautions, its identification and
struggles were informed and some suggestions were made about this case.
- Developing an effective vaccine against pandemic influenza poses both practical and immunological challenges. While current vaccines aim to induce antibodies that dampen viral replication, influenza viruses can evade the immune response through antigenic drift and shift. Effective vaccines need to induce antibodies throughout the respiratory tract to restrict viral replication at both upper and lower respiratory sites.
Avian influenza virus-infected poultry can release a large amount of virus-contaminated droppings that serve as sources of infection for susceptible birds. Much research so far has focused on virus spread within flocks. However, as fecal material or manure is a major constituent of airborne poultry dust, virus-contaminated particulate matter from infected flocks may be dispersed into the environment.
This study, demonstrates the presence of airborne influenza virus RNA downwind from buildings holding LPAI-infected birds, and the observed correlation between field data on airborne poultry and livestock associated microbial exposure and the OPS-ST model. These findings suggest that geographical estimates of areas at high risk for human and animal exposure to airborne influenza virus can be modeled during an outbreak, although additional field measurements are needed to validate this proposition. In addition, the outdoor detection of influenza virus contaminated airborne dust during outbreaks in poultry suggests that practical measures can assist in the control of future influenza outbreaks.
In general, exposure to airborne influenza virus on commercial poultry farms could be reduced both by minimizing the initial generation of airborne particles and implementing methods for abatement of particles once generated. As an example, emergency mass culling of poultry using a foam blanket over the birds instead of labor-intensive whole-house gassing followed by ventilation reduces both exposure of cullers and dispersion of contaminated dust into the environment, contributing to the control of influenza outbreaks.
Per contact probability of infection by Highly Pathogenic Avian InfluenzaHarm Kiezebrink
Estimates of the per-contact probability of transmission between farms of Highly Pathogenic Avian Influenza virus of H7N7 subtype during the 2003 epidemic in the Netherlands are important for the design of better control and biosecurity strategies.
We used standardized data collected during the epidemic and a model to extract data for untraced contacts based on the daily number of infectious farms within a given distance of a susceptible farm.
With these data, the ‘maximum likelihood estimation’ approach was used to estimate the transmission probabilities by the individual contact types, both traced and untraced.
The outcomes were validated against literature data on virus genetic sequences for outbreak farms. The findings highlight the need to
1) Understand the routes underlying the infections without traced contacts and
2) To review whether the contact-tracing protocol is exhaustive in relation to all the farm’s day-to-day activities and practices.
AI transmission risks: Analysis of biosecurity measures and contact structureHarm Kiezebrink
Contacts between people, equipment and vehicles prior and during outbreak situations are critical to determine the possible source of infection of a farm. Hired laborers are known to play a big role in interconnecting farms. Once a farm is infected, culling entire flock is the only option to prevent further spreading with devastating consequences for the industry.
In this paper, based on the HPAI outbreak in Holland 2003, the researchers found that 32 farms hired external labor of which seven accessed other poultry on the same day.
However, they were not the only ‘connectors’ as some (twelve) farmers also reported themselves helping on other poultry farms.
Furthermore, 27 farms had family members visiting poultry or poultry-related businesses of which nine entered poultry houses during those visits. The other enhancing factor of farm interconnections was the reported ownership of multiple locations for ten of the interviewed farms and the reported on-premises sale of farm products on one pullet and eight layer farms.
Also worth mentioning is the practice of a multiple age system reported on eight of the interviewed farms as this may increase the risk of infecting remaining birds when off-premises poultry movements occur.
AI viruses may be introduced into poultry from reservoirs such as aquatic wild birds but the mechanisms of their subsequent spread are partially unclear. Transmission of the virus through movements of humans (visitors, servicemen and farm personnel), vectors (wild birds, rodents, insects), air- (and dust-) related routes and other fomites (e.g., delivery trucks, visitors’ clothes and farm equipment) have all been hypothesized.
It is therefore hypothesized that the risk of introducing the virus to a farm is determined by the farm’s neighborhood characteristics, contact structure and its biosecurity practices.
On the one hand, neighborhood characteristics include factors such as the presence of water bodies (accessed by wild birds), the density of poultry farms (together with the number and type of birds on these farms) and poultry-related businesses and the road network. The use of manure in the farm’s vicinity is also deemed to be risky.
On the other hand, contact structure risk factors include the nature and frequency of farm visits. Therefore, a detailed analysis of the contact structure, including neighborhood risks, and biosecurity practices across different types of poultry farms and poultry-related businesses helps the improvement of intervention strategies, biosecurity protocols and adherence to these, as well as contact tracing protocols.
Farmers’ perception of visitor- and neighborhood-associated risks of virus spread is also important due to its relevance to adherence with biosecurity protocols, to contact tracing and to communicating advice to them.
This document discusses the use of subtractive genomics to identify potential drug targets for pathogenic organisms. Subtractive genomics involves subtracting the sequences between a host and pathogen's proteome to identify proteins essential to the pathogen but not present in the host. This approach has been applied to identify drug targets for multi-drug resistant pathogens like Salmonella typhi and Listeria monocytogenes, as well as pathogens with no existing effective drugs like Leishmania donovani and Clostridium botulinum. Identifying novel drug targets through subtractive genomics can help develop new defenses against antibiotic-resistant pathogens and treat diseases currently lacking effective treatments.
Human-to-Human transmission of H7H7 in Holland 2003Harm Kiezebrink
The outbreak of highly pathogenic avian influenza A virus subtype H7N7 started at the end of February, 2003, in commercial poultry farms in the Netherlands. In this study, published in The Lancet in 2004, it is noted that an unexpectedly high number of transmissions of avian influenza A virus subtype H7N7 to people directly involved in handling infected poultry, providing evidence for person-to-person transmission.
Although the risk of transmission of these viruses to humans was initially thought to be low, an outbreak investigation was launched to assess the extent of transmission of influenza A virus subtype H7N7 from chickens to humans.
453 people had health complaints—349 reported conjunctivitis, 90 had influenza-like illness, and 67 had other complaints. We detected A/H7 in conjunctival samples from 78 (26·4%) people with conjunctivitis only, in five (9·4%) with influenza-like illness and conjunctivitis, in two (5·4%) with influenza-like illness only, and in four (6%) who reported other symptoms. Most positive samples had been collected within 5 days of symptom onset. A/H7 infection was confirmed in three contacts (of 83 tested), one of whom developed influenza-like illness. Six people had influenza A/H3N2 infection. After 19 people had been diagnosed with the infection, all workers received mandatory influenza virus vaccination and prophylactic treatment with oseltamivir. More than half (56%) of A/H7 infections reported here arose before the vaccination and treatment programme.
This document discusses several emerging and re-emerging infectious diseases including SARS, MERS, Nipah virus, Chikungunya, West Nile virus, Lyme disease, Kyasanur forest disease. It provides details on the causative agents, modes of transmission, symptoms, treatment and prevention measures for each disease. It also discusses definitions of emerging and re-emerging diseases and factors responsible for their emergence or re-emergence such as rapid population growth, international travel, antibiotic resistance.
This paper reviews the evolution of the definition of sepsis and the controversy surrounding the sepsis-3 definition and the sepsis screening tool, qSOFA.
1) In 2011, scientists Kawaoka and Fouchier created a novel, mutated form of the H5N1 bird flu virus that was transmissible between ferrets. This raised concerns as the virus could potentially spread between humans.
2) The NSABB reviewed the research and deemed the papers too dangerous to publish in their original form due to risks of bioterrorism. However, censorship of scientific research poses risks to scientific progress.
3) There was debate around whether the benefits of understanding disease transmission outweighed the risks of potential misuse. Ultimately, a revised version of one paper was approved for publication while excluding certain methods details.
This document summarizes risk factors and response actions related to influenza A H1N1. It outlines background information on influenza strains and pandemics. The 2009 H1N1 strain was a combination of genes from swine, avian, and human influenza viruses. Studies identified higher risk groups as American Indians, younger/older individuals, and those with pre-existing medical conditions. Vaccination timing and strategies were modeled in Canada, showing reduced infection risk with vaccination. Key response actions included isolation, hand washing, and informing healthcare providers.
Gerunds are verb forms ending in "-ing" that function as nouns in sentences. Gerunds can serve as subjects, subject complements, direct objects, objects of prepositions, and appositives. The document provides examples of gerunds fulfilling each of these roles and discusses their use in literature, noting that gerunds give variation and nuance to writing.
This document discusses emerging and re-emerging infectious diseases. It begins with trends in infectious diseases, then defines emerging and re-emerging diseases. Factors that contribute to emergence include changes in the agent, host, and environment. Examples are provided of diseases that have emerged or re-emerged recently, including SARS, avian influenza, hepatitis C, and antibiotic resistance. The response from public health is also mentioned.
The document discusses the threat of pandemic influenza and the need for healthcare systems to prepare for disease outbreaks. It notes that recent outbreaks of avian influenza A(H5N1) are a reminder that a human pandemic could occur at any time, causing major suffering and economic losses. Past pandemics like the 1918 Spanish flu prompted authorities to plan for preparedness, but structured planning is still lacking in many healthcare systems. The ability of influenza viruses to mutate and reassort means a new pandemic strain could emerge.
This document describes a mathematical model of hepatitis B virus (HBV) transmission applied to the New Zealand Tongan population. The model predicts that with current infant vaccination coverage of 53%, chronic HBV prevalence will plateau at 2% over 250 years. However, 73% vaccination coverage is needed to eliminate HBV long-term. Improving coverage to 85% through targeted vaccination could arrest transmission within a generation and eliminate HBV, similar to outcomes in Taiwan and Alaska with similar policies. Screening and disease management may also help reduce the HBV burden, though its precise impact is hard to quantify. Mathematical models can help evaluate different control strategies for high prevalence populations.
1.SANITATION VS VACCINATION- The History of Infectious DiseasesAntonio Bernard
The document discusses the origins of many infectious diseases in humans. It notes that 60% of human infectious diseases originated in animals, and that diseases emerged as early humans increasingly domesticated animals like cows, pigs, chickens, and camels. Close contact between humans and domesticated, disease-carrying animals allowed pathogens to jump species. For example, measles likely emerged from cattle viruses, smallpox from camel viruses, influenza from duck viruses, and whooping cough and typhoid from pig bacteria. It was not until the domestication of these animals that humans were exposed to these diseases.
Man Vs Microbe - Pre-Apocalyptic Phase Failed? in IJAHSPreethi Selvaraj
This document discusses the ongoing battle between humans and microbes. It notes the rise of antibiotic-resistant superbugs like MDR-TB that are difficult to treat. Factors contributing to this include overprescription of antibiotics and patient non-compliance. It also discusses the threat of biological warfare, from small-scale food poisoning to mass attacks. Modern techniques allow biological agents to be easily spread through aerosols, contaminated food/water, and more. Stronger regulations on antibiotic usage and policies to defend against bioterrorism are needed to prevent a potential "apocalypse."
Some quick facts and numbers on Coronavirus (COVID-19) Slide Marvels
We pulled together some quick facts on Coronavirus.
Slide Marvels is a leading Presentation Design Company having experience of many years. We are a professional team of presentation designers who have already worked in major consulting firms like McKinsey & Co., Boston Consulting Group and Deloitte to mentioned some of them.
www.slidemarvels.com
The local and global stability of the disease free equilibrium in a co infect...iosrjce
IOSR Journal of Mathematics(IOSR-JM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mathemetics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mathematics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
120 EXPERT Opinions on Coronavirus (COVID-19)- How the Mass Media Exaggerated...Antonio Bernard
This document provides over 120 expert opinions from scientists, doctors, and other professionals criticizing the handling of the coronavirus pandemic. Many experts argue that the virus poses a relatively low risk and that measures like lockdowns and business closures are an overreaction that will cause more harm than the virus itself. Other opinions expressed include that the infection fatality rate is much lower than estimates from the WHO, that social distancing has not been shown to be effective, and that the media coverage has caused unnecessary panic.
Human Noroviruses (HuNoVs) are important enteric pathogens, which affect the stomach and intestines, leading to
gastroenteritis or more commonly called the "stomach flu" or “winter vomiting bug". HuNoVs are mainly transmitted by the fecal-oral
route, either by directly infected person-to-person contact or directly via contaminated foods, water and surface areas. The virus is highly
contagious as 10-100 virus particles are sufficient to cause diseases. HuNoVs can spread easily and cause prolonged outbreaks. This is
due to their environmental persistence, high infectivity, being resistance to disinfection and difficulty in preventing transmission.
HuNoVs are the most common causative agent leading to acute gastroenteritis among infectious diseases worldwide and poses a serious
public health problem, especially among children being the most susceptible. In developing countries, the highest cost of medical care
after respiratory infections is listed for acute gastroenteritis. In this study, Norovirus outbreaks, precautions, its identification and
struggles were informed and some suggestions were made about this case.
- Developing an effective vaccine against pandemic influenza poses both practical and immunological challenges. While current vaccines aim to induce antibodies that dampen viral replication, influenza viruses can evade the immune response through antigenic drift and shift. Effective vaccines need to induce antibodies throughout the respiratory tract to restrict viral replication at both upper and lower respiratory sites.
Avian influenza virus-infected poultry can release a large amount of virus-contaminated droppings that serve as sources of infection for susceptible birds. Much research so far has focused on virus spread within flocks. However, as fecal material or manure is a major constituent of airborne poultry dust, virus-contaminated particulate matter from infected flocks may be dispersed into the environment.
This study, demonstrates the presence of airborne influenza virus RNA downwind from buildings holding LPAI-infected birds, and the observed correlation between field data on airborne poultry and livestock associated microbial exposure and the OPS-ST model. These findings suggest that geographical estimates of areas at high risk for human and animal exposure to airborne influenza virus can be modeled during an outbreak, although additional field measurements are needed to validate this proposition. In addition, the outdoor detection of influenza virus contaminated airborne dust during outbreaks in poultry suggests that practical measures can assist in the control of future influenza outbreaks.
In general, exposure to airborne influenza virus on commercial poultry farms could be reduced both by minimizing the initial generation of airborne particles and implementing methods for abatement of particles once generated. As an example, emergency mass culling of poultry using a foam blanket over the birds instead of labor-intensive whole-house gassing followed by ventilation reduces both exposure of cullers and dispersion of contaminated dust into the environment, contributing to the control of influenza outbreaks.
Per contact probability of infection by Highly Pathogenic Avian InfluenzaHarm Kiezebrink
Estimates of the per-contact probability of transmission between farms of Highly Pathogenic Avian Influenza virus of H7N7 subtype during the 2003 epidemic in the Netherlands are important for the design of better control and biosecurity strategies.
We used standardized data collected during the epidemic and a model to extract data for untraced contacts based on the daily number of infectious farms within a given distance of a susceptible farm.
With these data, the ‘maximum likelihood estimation’ approach was used to estimate the transmission probabilities by the individual contact types, both traced and untraced.
The outcomes were validated against literature data on virus genetic sequences for outbreak farms. The findings highlight the need to
1) Understand the routes underlying the infections without traced contacts and
2) To review whether the contact-tracing protocol is exhaustive in relation to all the farm’s day-to-day activities and practices.
AI transmission risks: Analysis of biosecurity measures and contact structureHarm Kiezebrink
Contacts between people, equipment and vehicles prior and during outbreak situations are critical to determine the possible source of infection of a farm. Hired laborers are known to play a big role in interconnecting farms. Once a farm is infected, culling entire flock is the only option to prevent further spreading with devastating consequences for the industry.
In this paper, based on the HPAI outbreak in Holland 2003, the researchers found that 32 farms hired external labor of which seven accessed other poultry on the same day.
However, they were not the only ‘connectors’ as some (twelve) farmers also reported themselves helping on other poultry farms.
Furthermore, 27 farms had family members visiting poultry or poultry-related businesses of which nine entered poultry houses during those visits. The other enhancing factor of farm interconnections was the reported ownership of multiple locations for ten of the interviewed farms and the reported on-premises sale of farm products on one pullet and eight layer farms.
Also worth mentioning is the practice of a multiple age system reported on eight of the interviewed farms as this may increase the risk of infecting remaining birds when off-premises poultry movements occur.
AI viruses may be introduced into poultry from reservoirs such as aquatic wild birds but the mechanisms of their subsequent spread are partially unclear. Transmission of the virus through movements of humans (visitors, servicemen and farm personnel), vectors (wild birds, rodents, insects), air- (and dust-) related routes and other fomites (e.g., delivery trucks, visitors’ clothes and farm equipment) have all been hypothesized.
It is therefore hypothesized that the risk of introducing the virus to a farm is determined by the farm’s neighborhood characteristics, contact structure and its biosecurity practices.
On the one hand, neighborhood characteristics include factors such as the presence of water bodies (accessed by wild birds), the density of poultry farms (together with the number and type of birds on these farms) and poultry-related businesses and the road network. The use of manure in the farm’s vicinity is also deemed to be risky.
On the other hand, contact structure risk factors include the nature and frequency of farm visits. Therefore, a detailed analysis of the contact structure, including neighborhood risks, and biosecurity practices across different types of poultry farms and poultry-related businesses helps the improvement of intervention strategies, biosecurity protocols and adherence to these, as well as contact tracing protocols.
Farmers’ perception of visitor- and neighborhood-associated risks of virus spread is also important due to its relevance to adherence with biosecurity protocols, to contact tracing and to communicating advice to them.
This document discusses the use of subtractive genomics to identify potential drug targets for pathogenic organisms. Subtractive genomics involves subtracting the sequences between a host and pathogen's proteome to identify proteins essential to the pathogen but not present in the host. This approach has been applied to identify drug targets for multi-drug resistant pathogens like Salmonella typhi and Listeria monocytogenes, as well as pathogens with no existing effective drugs like Leishmania donovani and Clostridium botulinum. Identifying novel drug targets through subtractive genomics can help develop new defenses against antibiotic-resistant pathogens and treat diseases currently lacking effective treatments.
Human-to-Human transmission of H7H7 in Holland 2003Harm Kiezebrink
The outbreak of highly pathogenic avian influenza A virus subtype H7N7 started at the end of February, 2003, in commercial poultry farms in the Netherlands. In this study, published in The Lancet in 2004, it is noted that an unexpectedly high number of transmissions of avian influenza A virus subtype H7N7 to people directly involved in handling infected poultry, providing evidence for person-to-person transmission.
Although the risk of transmission of these viruses to humans was initially thought to be low, an outbreak investigation was launched to assess the extent of transmission of influenza A virus subtype H7N7 from chickens to humans.
453 people had health complaints—349 reported conjunctivitis, 90 had influenza-like illness, and 67 had other complaints. We detected A/H7 in conjunctival samples from 78 (26·4%) people with conjunctivitis only, in five (9·4%) with influenza-like illness and conjunctivitis, in two (5·4%) with influenza-like illness only, and in four (6%) who reported other symptoms. Most positive samples had been collected within 5 days of symptom onset. A/H7 infection was confirmed in three contacts (of 83 tested), one of whom developed influenza-like illness. Six people had influenza A/H3N2 infection. After 19 people had been diagnosed with the infection, all workers received mandatory influenza virus vaccination and prophylactic treatment with oseltamivir. More than half (56%) of A/H7 infections reported here arose before the vaccination and treatment programme.
This document discusses several emerging and re-emerging infectious diseases including SARS, MERS, Nipah virus, Chikungunya, West Nile virus, Lyme disease, Kyasanur forest disease. It provides details on the causative agents, modes of transmission, symptoms, treatment and prevention measures for each disease. It also discusses definitions of emerging and re-emerging diseases and factors responsible for their emergence or re-emergence such as rapid population growth, international travel, antibiotic resistance.
This paper reviews the evolution of the definition of sepsis and the controversy surrounding the sepsis-3 definition and the sepsis screening tool, qSOFA.
1) In 2011, scientists Kawaoka and Fouchier created a novel, mutated form of the H5N1 bird flu virus that was transmissible between ferrets. This raised concerns as the virus could potentially spread between humans.
2) The NSABB reviewed the research and deemed the papers too dangerous to publish in their original form due to risks of bioterrorism. However, censorship of scientific research poses risks to scientific progress.
3) There was debate around whether the benefits of understanding disease transmission outweighed the risks of potential misuse. Ultimately, a revised version of one paper was approved for publication while excluding certain methods details.
This document summarizes risk factors and response actions related to influenza A H1N1. It outlines background information on influenza strains and pandemics. The 2009 H1N1 strain was a combination of genes from swine, avian, and human influenza viruses. Studies identified higher risk groups as American Indians, younger/older individuals, and those with pre-existing medical conditions. Vaccination timing and strategies were modeled in Canada, showing reduced infection risk with vaccination. Key response actions included isolation, hand washing, and informing healthcare providers.
Gerunds are verb forms ending in "-ing" that function as nouns in sentences. Gerunds can serve as subjects, subject complements, direct objects, objects of prepositions, and appositives. The document provides examples of gerunds fulfilling each of these roles and discusses their use in literature, noting that gerunds give variation and nuance to writing.
Planned Organizational Change Consequent to Advanced Manufacturing Technology...paperpublications3
Abstract: Organizational change consequent to the implementation of advanced manufacturing technology has been mentioned in the production management literature. However, this literature lacks a body of research studies to validate these claims in developing economy. As technology is linked to competitive advantage of many manufacturing firms, the implementation of new technology in the existing resources should be carried out with planned organizational change. This paper highlights the importance of technology-organizational change and the fit between them in the modern manufacturing firms in developing county’s social economic framework in the context of global competition.
Abstract:Savings are necessary if investment, and hence economic growth and development are to be stimulated. The paper looks at the broad set of possible determinants of private savings in Lesotho using annual time series data for the period 1980-2010. The paper estimates the saving rate function and Error-Correction modelling is used to avoid spurious results. The results indicate that public savings are important in explaining changes in private savings, both in the short-run and long-run and that the terms of trade negatively influence private savings in Lesotho in the long-run.
Influence of Human Factors on the Relationship between AMT Adoption and Organ...paperpublications3
Abstract: the study used the contingency theory to study the effects of human factors on the relationship between Advanced Manufacturing Technology (AMT) adoption and organization structure. When empirically tested, the research findings present the interrelationships among the main effects (AMT index and human factors) and the interactions (AMT index*human factor index). The study revealed that there is a linear dependence of organizational index from the interaction index. This implies that changes in human factors positively and significantly affect AMT adoption and organizational structure relationship. The study confirms that it is essential for a company to match their technology investment and its integration with its human factors in order to achieve the intended manufacturing performance. The degree of fit between AMT index and organizational index was found to increase as human index increased. The findings of this study reiterate the importance and the need for proactive planning to facilitate changes in the organizational structure.
Abstract: Discouraged Youth’ is defined as those youth who are not working even though they have expressed a desire to work, but due to the fact that they felt that undertaking a job search would be a futile effort, have not continued with the effort to seek a job . The magnitude of this crisis is a cause for concern for Mauritius; hence this study was conducted with the objective of creating a deeper understanding of discouraged youth. Primary data is used for this study, and the survey covers a sample of 500 unemployed youth across the island. The probit regression model is used to analyse the determinants affecting discouraged youth. The findings of the study found that age, age2, marital status, gender and tertiary education, area of study based on friend’s opinion, length of unemployment less than 12 months and prior experience have an impact on discouraged youth. From the analysis it was noted that education and training systems should be revisited to bridge the skills gap.
A Review on Suppression of Secondary Arc Current Trough Single-Phase Auto-Rec...paperpublications3
Abstract: When single-phase to ground fault occurs in high voltage transmission line, secondary arc current and recovery voltage must be suppressed in order to ensure that single-phase auto-reclosing operates reliably and successfully.
This work adopts the suppression measure of secondary arc current using shunt reactor with neutral small reactor-which is applied widely in India, and then uses MATLAB Simulink software to simulate suppression effect about different fault point locations toward an example of 735kv double-ended sources high-voltage transmission line. According to the simulation results, suppression effects about different locations are distinct. Moreover, this measure can suppress secondary arc current effectively, ensure success of single phase auto-reclosing operation and finally achieve security and stability of power system.
Study of Bio-Nano Composite of Poly-Lactic Acid for Food Packaging- A Reviewpaperpublications3
Abstract: The impact of environment, economic and safety challenges have provoked the need to partially substitute petrochemical based polymer with bio degradable ones. [Poly lactic acid] PLA is the leading biodegradable polymer but its applications are limited by its relatively high cost, poor impact strength and barrier properties, which may be improved by adding reinforcing compounds (fillers), forming composites. Most reinforced materials present poor matrix–filler interactions, which tend to improve with decreasing filler dimensions. The use of fillers with at least one nanoscale dimension (nanoparticles) produces nanocomposites. Nanoparticles have proportionally larger surface area than their microscale counterparts, which favors the filler–matrix interactions and the performance of the resulting material.
Applications of nanomaterials in combination with PLA structures for creating new PLA nanocomposite with greater abilities are also covered. These approaches may modify PLA weakness for some food packaging applications. Nanotechnology approaches are being broadened in food science, especially in packaging material science with high performance and low concentrations and prices, so this category of nano-research is estimated to be revolutionary in food packaging science in the near future. The linkage of the 100% bio originated material and nanomaterial opens new windows for becoming independent, primarily, of petrochemical based polymers and, secondarily, for answering environmental and health concerns will undoubtedly be growing with time.
This study seeks to overcome PLA limitations by reinforcing PLA with nanoparticles and low-cost agricultural residues. The work presented in this thesis focuses on exploration of following relevant aspects:
• Preparation of PLA nanocomposite from LA [lactic acid].
• Reinforcement of various fillers during preparation.
• Testing of the formed nanomaterial to study the enhanced properties for sustainable green food packaging.
• Comparative study of the newly formed nanocomposites with respect to its properties
Nanotechnology has demonstrated a great potential to provide important changes in food packaging sector.
Nanocomposites are promising to expand the use of bio-degradable polymer, since the addition of nanoreinforcement has been related to improvement in overall performance of biopolymers, making them more competitive in a market dominated by non-biodegradable materials.
DESIGN AND DEVELOPMENT OF SMES BASED DVR MODEL IN SIMULINKpaperpublications3
Abstract: In this paper, A SMES based DVR model is presented and Modelled with the help of simulink block. Superconducting magnetic energy storage (SMES) is considered as the future energy storage devices. In this work SMES is used for storing the DC energy and at the time of Requirement provide this energy to the main line with the help of DVR (Dynamic Voltage restorer). Simulation Result shows the compensation ability of this DVR.
Family Attachment to Coffee Farms, a Case of Coffee Farming in Kisii County, ...paperpublications3
Abstract: Coffee farmers are elderly averaging 55 years of age and have a high attachment to coffee farms. Coffee is an important crop to the Kenyan economy as it is the fourth foreign exchange earner. The study was carried out to establish the extent of family attachment to farms and particularly coffee farms. Random sampling procedure was employed to obtain data using structured questionnaires, interviews and focus group discussion on a sample of 227 from a target population of 900 coffee farmers in Kisii County. Research was analyzed at 0.05 level of significance using Pearson Correlation with aid of Statistical Package for Social Science. The research findings showed that 62.1% considered important that farm stayed in family ownership, 70.1% considered farm stays farmed by the family, while 73.8% would wish to continue earning from coffee farms even when they will be old enough to carry out farming. Furthermore 45.4% of the respondents indicated unwillingness of retiring from active farming even at old age. The study found the mean age of farmers to be 57 years while mean acreage of farms being 1.67 acres. The research findings give information on the level of family attachment on coffee farms and how it may direct extension approach in pursuit of improved coffee production.
The Prevalence of Pseudomonas Aeruginosa on Recommended Glasses of Selected V...paperpublications3
Abstract: This study was carried out to assessed the prevalence of Pseudomonas aeruginosa on the recommended glasses of selected volunteers in Olabisi Onabanjo University Teaching Hospital Sagamu Campus. A cross-sectional survey of 100 selected volunteers comprises 43males and 57 females were examined. A total of 30 (30%) were found to have Pseudomonas aeruginosa on their contact lenses, of which 13(43.3%) of the isolates were pigmented and 17(56.7%) were non pigmented isolates of Pseudomonas aeruginosa. Eighty percent (80%) of the isolates were susceptible to ciprofloxacin, 63% to ceftazidime while 50% were susceptible to ofloxacin. The isolates were totally resistant to augmentin and ampicillin, while 97% resistant to gentamicin and 70% resistant ton nitrofurantoin were recorded in this study. Thus, ciprofloxacin and ceftazidime could be recommended for the management of Pseudomonas aeruginosa on contact lenses.
PRELIMINARY STUDY ON NUTRIENT REMOVAL OF DAIRY WASTEWATER BY PILOT SCALE SUBS...paperpublications3
Abstract: This study was conducted to examine the nutrient removal efficiency of pilot scale Constructed Wetland (CW) designed to treat dairy wastewater. Two pilot scale fiber glass wetland units were constructed to function as Subsurface Horizontal Flow (SSHF) CWs. A gravel based medium was layered for inlets and outlets of each unit. Constructed Wetland bed was filled with sand and the upper layer was filled with compost: top soil mixture (1:2). Both units were planted with Schoenoplectus grossus (Giant bulrush).After establishing plants for three months, the treatment unit was saturated with seven Biochemical Oxygen Demand (BOD) loads of diluted and neutralized dairy wastewater ranging from 5g/m2d , 16g/m2d, 20g/m2d, 24g/m2d,33g/m2d, 48g/m2d and 186 g/m2d. Seven days were maintained as effective retention time under each BOD load. Control unit was maintained without the addition of dairy wastewater. Samples were collected from the inlets and outlets of each unit and analyzed for BOD, Chemical Oxygen Demand (COD),Total Nitrogen (TN) and Total Phosphorous (TP).Removal efficiencies of BOD, COD, TN and TP were calculated. The results of this study showed BOD removal efficiencies in the range of 30%-100%, COD removal efficiencies in the range of 75%-92%, TN removal efficiencies in the range of 40%-100% and for TP in the range of 0%-100% with respect to studied loading rates. Based on these results this paper suggests that this type of pilot scale SSHF CWs planted with Scheonoplectus grossus is appropriate for removal of BOD, COD, TN and TP in dairy wastewater arising from small and medium sector dairy industries.
Rainfall Trend Analysis of Mysore District in Karnatakapaperpublications3
Abstract:The daily rainfall data of Mysore district of Karnataka for last 39 years (1971-2009) were analyzed to study its variability. Being a part of the semi-arid region it receives mean annual rainfall of 834.2 mm with 25.8 per cent variability. The contributing from winter, pre-monsoon, monsoon and post monsoon period to the total rainfall was 1.2, 11.0, 43.7 and 28.1 per cent. Each standard meteorological week (SMW) from 16th to 46th receive a rainfall of above 20 mm with less variability (within 150%) indicating the crop growing period from 2nd fortnight of April to 2nd fortnight of November. The monthly mean rainfall was observed to be 75.7, 133.0, 75.5, 79.6, 88.2, 120.9, 159.4 and 60.6 for April, May, June, July, August, September October and November months, respectively. The trend analysis of rainfall indicated that, the mean annual rainfall was changing since 1971with increasing trend in variability in alternative 10 years cycle. Being a semi-arid climate, Mysore district was frequently affected by periodical drought and the study indicated out of past 39 years, one year was slight drought (-19 to -25% D from N) and 6 years were falls under moderate drought (-26 to -50% D from N).
A Descriptive Study to Assess the Quality of Marital Life among the Wives of ...paperpublications3
Abstract: The study was conducted to assess quality of marital life among the wives of alcoholic dependents at selected de addiction center, Puducherry. A non experimental descriptive design was carried out and wives whose husbands meet with diagnostic criteria of alcoholic dependent syndrome as per ICD-10 were selected by using purposive sampling technique. In this study, the level of quality of marital life was assessed by using marital quality scale developed by Shah (1995).The results revealed that the percentage distribution level of quality of marital life among the wives of alcoholic dependents were with moderate quality of about 62%.
Monitoring and Controlling Of Electric Overhead Travelling Crane Using PLC an...paperpublications3
Abstract: PLC and SCADA are the two new approaches used to control the motion of Electric Overhead travelling crane. Ladder logic diagram for EOT Cranes are designed for motion using variable frequency drives and contactor logic and performance of various parameters are analyzed and compared and image of E.O.T crane are designed in SCADA software and communication between PLC and Scada is done with the help of Siemens simulator .There is a provision of hydraulic motor for motion in main hoist if power failure of cranes takes place to avoid the unsafe condition and work under extreme condition.
Internal Audit Independence and Share Performance of Firms Listed In the Nair...paperpublications3
This study examined the relationship between internal audit independence and share performance of firms listed on the Nairobi Stock Exchange. The study found a positive correlation between internal audit independence and share performance. Specifically, the study found that internal audit independence is integral to effective corporate governance and that independent internal audits are well positioned to identify accounting, control, and governance issues that could impact share performance. The study concluded that listed companies should adopt governance practices that ensure audit independence in order to improve returns and attract more investors.
Problems and Prospects of SMES Loan Management: Case of Lesothopaperpublications3
Abstract: Small and medium enterprises play a fundamental role in economic growth and developments. The economies of all market-oriented nations depend on the efficient operation of complex and delicately balanced indispensable element in these systems - systems of money and credit However, historically SMEs financing remains as major challenge to the growth of SME. This paper therefore tries to identify some underlying problems from the banks perspective. This study is based on primary data which is collected through personal interview with structured questionnaire and direct observations. Findings indicate that banks appear to be facing serious challenges of high cost of gathering information and collateral. Both high costs to gather reliable information on SMEs and high administration costs on loans made to SMEs were found to have fundamental impact on SME lending. Though lack of finance appears to be a major challenge hindering SMEs growth, this hindrance may be mostly enhanced by constraints that are within SMEs themselves.
Rainfall Trend Analysis of Hassan District in Karnatakapaperpublications3
Abstract: The daily rainfall data of Hassan district of Karnataka for last 39 years (1971-2009) were analyzed to study its variability. Being a part of the semi-arid region it receives mean annual rainfall of 784.6 mm with 28.2 per cent variability. The contributing from winter, pre-monsoon, monsoon and post monsoon period to the total rainfall was 0.8, 8.3, 56.5 and 23.3 per cent, respectively. Each standard meteorological week (SMW) from 18th to 45th receive a rainfall of above 20 mm with less variability (within 145%) indicating the crop growing period from 1st fortnight of May to 1st fortnight of November. The monthly mean rainfall was observed to be 87.2, 106.6, 126.3, 101.3, 109.0, 127.5 and 46.5 for May, June, July, August, September, October and November months, respectively. The trend analysis of rainfall indicated that, the mean annual rainfall was more or less similar since 1971, however, the variability was showed increasing trend from 1971-1980 to 2001-2009. Being a semi-arid climate, Hassan district was frequently affected by periodical drought and the study indicated out of past 39 years 5years were experienced the slight drought (-19 to -25% D from N), 5 years were falls under moderate drought (-26 to -50% D from N) and one year (1996) was severe drought with -72.3% deviation from Normal.
Application of Weighted Least Squares Regression in Forecastingpaperpublications3
Abstract: This work models the loss of properties from fire outbreak in Ogun State using Simple Weighted Least Square Regression. The study covers (secondary) data on fire outbreak and monetary value of properties loss across the twenty (20) Local Government Areas of Ogun state for the year 2010. Data collected were analyzed electronically using SPSS 21.0. Results from the analysis reveal that there is a very strong positive relationship between the number of fire outbreak and the loss of properties; this relationship is significant. Fire outbreak exerts significant influence on loss of properties and it accounts for approximately 91.2% of the loss of properties in the state.
Juice ImagesSuperStockLearning Objectives1. Compare t.docxpriestmanmable
Juice Images/SuperStock
Learning Objectives
1. Compare the basic biological distinctions of HIV and AIDS
2. Describe how an HIV/AIDS diagnosis affects different individual, familial, and social domains
3. Understand the clinical and social implications of an HIV/AIDS diagnosis during different stages
of the life cycle
4. Demonstrate an understanding of ART regimens and other treatment methods
5. Understand the role of stigma and discrimination in screening, treatment, and prevention
interventions
6. Identify the unique issues of HIV/AIDS management in ambulatory care settings
7. Describe how an understanding of the ecology of HIV/AIDS can improve individual, social,
and policy issues
Blood and Immune System
Disorders: HIV/AIDS
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Tan tan/Imaginechina/Associated Press
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CHAPTER 4Section 4.1 Introduction to HIV/AIDS
4.1 Introduction to HIV/AIDS
In June 1981, the U.S. Centers for Disease Control and Prevention (CDC) published a report on the clinical condition of five young male homosexuals who all presented the same unusual group of symptoms (CDC, 1981b). Although these individuals had previously been healthy,
they were all diagnosed with Pneumocystis carinii pneumonia (PCP), a rare condition associated
with a severely compromised immune system. Three weeks later, another report from the CDC
documented 26 gay men in New York and California with compromised immune systems from
both PCP and the cancer Kaposi sarcoma (CDC, 1981a). Although initially given the acronym GRID
(gay-related immune deficiency, because of the sexuality of the men in these initial cases), this
disease eventually came to be known by the acronym HIV/AIDS.
Clinical Overview
HIV stands for human immunodeficiency virus. This term means several things: (a) It is a condition
that can only infect humans beings (H); (b) it compromises immune systems (I); and (c) it is a
virus (V), an infectious organism that invades living cells. Because HIV is a viral infection (as is the
common cold), it results from exposure to a pathogen. However, HIV is more threatening than a
cold virus because the human body is unable to fight it off. Once infected, people never recover,
even though they may be asymptomatic. And, as with other chronic diseases, they must live with
the condition throughout their lives.
Although our bodies have built-in mechanisms designed to fight disease, HIV attacks CD4-positive
T cells, which in human immunology is a type of white blood cell vital to fighting off infections and
foreign microbes. HIV launches its attack by first invading these cells so it can replicate; afterward,
it destroys the cells. Eventually, when a person’s CD4 cells fall below a specified level, the immune
system has been compromised. This criterion leads to a diagnosis of AIDS, which is an acronym for
acquired immunodeficiency syndrome.
The designation acquired means that the ons ...
The document discusses HIV/AIDS, providing definitions and explaining how HIV infects cells, replicates, and over time destroys the immune system. It notes that HIV targets and infects CD4 cells (T-cells), using them to replicate and eventually killing them. This depletion of CD4 cells leaves the body vulnerable to opportunistic infections defining AIDS. The stages of HIV infection and factors that affect disease progression are also summarized.
There are nearly 100 viruses of the herpes group that infect many different animal species.
Official name of herpesviruses that commonly infect human is Humans herpesvirus (HHV)
herpes simplex virus types 1 (HHV 1)
Herpes simplex virus type 2 (HHV 2)
Varicella-zoster virus (HHV 3)
Epstein-Barr virus, (HHV 4)
Cytomegalovirus (HHV 5)
Human herpesvirus 6 (HHV 6)
Human herpesvirus 7 (HHV 7)
Human herpesvirus 8 (HHV 8) (Kaposi's sarcoma-associated herpesvirus).
Herpes B virus of monkeys can also infect humans
hELMINTHS#corona virus#Aspergillosis#BUGANDO#CUHAS#CUHAS#CUHAS
This document summarizes a student's paper on HIV/AIDS pathogenesis. It begins by outlining the epidemiology of HIV/AIDS, including its origins in 1959 in Congo and transmission routes. It then describes the structure and replication cycle of HIV in detail. The stages of HIV disease progression are explained as acute infection, asymptomatic chronic phase, and symptomatic AIDS. The paper also reviews presentations by HIV experts and fellow student presentations addressing treatment options and the social impacts of HIV/AIDS.
This study examines the prevalence of HIV among women in Gambia through a prospective cohort study of HIV seropositive pregnant women, postpartum women within 6 weeks of delivery, and their infants up to 6 months old. The study population is chosen because Gambia has a higher prevalence of HIV among women (7.6 per 1000) compared to other West African countries (3.1 per 1000). The study will be conducted over three years to understand HIV rates in this high risk population.
The document discusses pathophysiology of HIV/AIDS. It defines HIV as a retrovirus that causes AIDS by infecting CD4+ T cells and suppressing the immune system. This leaves the body susceptible to opportunistic infections. The document summarizes the stages of HIV infection from acute infection to development of AIDS, as well as the clinical manifestations and complications of HIV/AIDS such as wasting syndrome, opportunistic infections, and cancers. Treatment options for HIV/AIDS are also briefly mentioned.
This presentation provides an overview of HIV and AIDS, including:
1. Definitions of HIV as the virus that causes AIDS and weakens the immune system, and AIDS as the final stage of HIV infection.
2. HIV-1 is the most common type worldwide and generally causes AIDS faster than HIV-2, which is mostly found in West Africa.
3. HIV is transmitted through bodily fluids and can be spread through unprotected sex, blood contact, or from mother to child during pregnancy or breastfeeding. Proper precautions can prevent transmission.
The document discusses AIDS and lentiviruses. It covers topics such as the origin of HIV from primate lentiviruses, the classification and properties of lentiviruses, HIV infections in humans including pathogenesis and pathology, virus receptors, and the roles of CD4 T lymphocytes, monocytes, macrophages, and lymphoid organs in HIV infection.
This document provides a summary of mathematical modeling of HIV/AIDS treatment. It discusses the background and history of the HIV epidemic, noting that the number of people living with HIV has increased to 32-38 million globally since 1981. Prevention programs like antiretroviral treatment (ART) have helped reduce prevalence since 1999. The document examines the natural history and transmission of HIV, antiretroviral therapy, socioeconomic risks, and the genetic structure and replication cycle of HIV. It states the problem is determining the optimal timing for ART initiation to increase immunity and decrease mortality and mobility from the disease.
Peer response must add interesting facts and research to.docx4934bk
Human immunodeficiency virus (HIV) is a retrovirus that attacks the body's immune system and progresses through three stages: acute HIV, chronic HIV, and acquired immunodeficiency syndrome (AIDS). It can be transmitted sexually or through contact with infected blood. While there is no cure for HIV, effective treatment can suppress the virus and allow those infected to live long, healthy lives. Common prevention methods include condom use and avoiding needle sharing. HIV continues to be monitored and researched in efforts to control emerging variants.
AIDS is a syndrome in which the body undergoes the loss of cellular immunity which lower the body’s ability to fight against disease. The cause of AIDS is a retrovirus called Human Immunodeficiency Virus HIV . The symptoms of AIDS usually start from 3 6 weeks and are mild symptoms like fever, rash, swollen glands, and body ache which are followed by characteristic AIDS symptoms which may appear within 10 years of infection. In world till 2017 genome sequencing of the virus, sub typing of the virus, recombinant forms of the virus has been deeply discovered and studied which helps in better diagnosis and in choosing the strategies for treatment. The objective of this review is to give a brief history and current picture of HIV prevalence and describe its pathophysiology and modes of transmission. And how it is diagnosed, sign and symptoms, treatment and how it can be prevented. Ch. Teshil Maring | Gaurav Kumar Sharma | Kaushal Kishore Chandrul "A Review: AIDS" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd45188.pdf Paper URL: https://www.ijtsrd.com/other-scientific-research-area/other/45188/a-review-aids/ch-teshil-maring
This document presents a mathematical model analyzing the global stability of the endemic equilibrium of HIV/AIDS with a drug-resistant compartment. The model divides the total population into five compartments: susceptible individuals, infectious individuals not receiving treatment, infectious individuals receiving treatment who are drug resistant, infectious individuals receiving treatment who are not drug resistant, and AIDS individuals. The basic reproduction number is calculated using next generation matrix methods. Analysis using Lasalle's invariant principle finds that the endemic equilibrium of the model is globally asymptotically stable.
HIV causes AIDS by destroying CD4+ T cells, leaving the immune system vulnerable to opportunistic infections. It is a retrovirus that enters cells via CD4 and a coreceptor. It inserts its genetic material into the host cell DNA. New virus particles are assembled and exit to infect other cells. Highly active antiretroviral therapy can slow the virus but has limitations like side effects, cost and drug resistance. HIV originated from cross-species transmission of simian immunodeficiency viruses infecting chimpanzees and mangabeys.
The document discusses HIV and AIDS. It provides information on:
- The structure and life cycle of HIV.
- How HIV infects and destroys CD4+ T cells, leading to immunosuppression and susceptibility to opportunistic infections.
- The typical stages of untreated HIV infection from acute infection to AIDS, defined as a CD4 count below 200 or an AIDS-defining condition.
- Common opportunistic infections and cancers seen in AIDS patients due to severe immune deficiency.
HIV/AIDS is caused by the human immunodeficiency virus (HIV) which attacks CD4 T-cells and weakens the immune system. This leaves individuals vulnerable to opportunistic infections. While there is no cure for AIDS, antiretroviral drug combinations can suppress the virus and allow immune recovery. However, HIV persists in reservoirs and treatment must continue to prevent resurgence. Prevention efforts focus on behavior changes like abstinence and condom use as well as reducing needle sharing. Access to treatment varies globally and developing nations often lack resources for advanced therapies available elsewhere. Education has helped curb transmission in some African countries but challenges remain in combating misinformation and harmful practices.
ABSTRACT- Human immunodeficiency virus (HIV) is a major contributor to the global burden of the disease, opportunistic infections, and tumors follow. HIV also directly attacks the immune system and affects certain body’s system (like Central Nervous System, Respiratory and Cardiovascular Systems, Digestive System etc). HIV transmission is complex and depends on the number of behavioral and biological co-factors. The hallmark of HIV infection is the progressive depletion of CD4 helper T cells because of reduced production and increased destruction. Although the typical HIV infected patient shows a sustained CD4 cell increase, a remarkable number of subjects never achieve normal ranges of CD4. HIV infection is also characterized by a marked increase in immune activation, which includes both the adaptive and innate immune systems and abnormalities in coagulation. Extraordinary efforts in the fields of clinical, pharmacology, and biology care have contributed to progressively turn HIV infection from an unavoidably fatal condition into a chronic manageable disease, at least in the countries where HIV infected people have full access to the potent anti-retroviral (ARV) drug combinations that permit a marked and sustained control of viral replication. Although their pathogenesis is still under discussed, they are likely to originate from immune dysfunction associated with HIV infection and chronic inflammation. The last consideration regards the dis-homogenous pattern of HIV disease worldwide. Key-words- Human immunodeficiency virus (HIV), simian immunodeficiency viruses (SIV), Antiretroviral (ARV) therapy, Acquired immunodeficiency syndrome (AIDS), Cell mediated immunity (CMI), Anti-retroviral agents
NPF: AIDS 2010 Refresher for Vienna JournalistsDaric Snyder
This document provides a summary of a refresher course on HIV/AIDS for journalists. It covers HIV/AIDS from both a medical/scientific perspective and a public health perspective. From a medical perspective, it explains how HIV infects and destroys CD4 cells, eventually overcoming the immune system. From a public health perspective, it discusses populations vulnerable to HIV, modes of transmission, and prevention strategies at both personal and societal levels. It emphasizes that until a vaccine or cure is developed, prevention must be the focus. The document compares the perspectives of medicine and public health and stresses journalists' important role in educating the public about HIV/AIDS.
Modeling and Simulation of Spread and Effect of Malaria EpidemicWaqas Tariq
The purpose of this paper is to consider malaria infection (A) and the control of malaria (B) as the two sets of soldiers engage in a war. The principal objectives are to see if it is possible with time to reduce and eradicate malaria in our environment taking reasonable precaution. The methodology approach is to model a mathematical equation using battling method approach to find the time(t) that control malaria in our environment will conquer the malaria infection i.e. when A(t)=0. The number of provided facilities (n) for the protection of malaria is also considered and varied. The result shows that as the number of malaria control increases the control time is decreasing.
1. HIV/AIDS remains a major global public health issue, with sub-Saharan Africa disproportionately affected.
2. HIV targets CD4 cells and progressively destroys the immune system, leaving the body vulnerable to opportunistic infections.
3. The virus has several stages in its lifecycle within the human body, allowing it to evade detection and establish chronic, long-term infection.
immunobiology of hiv virus human immunodeficeincy virusAkshay Raj
HIV infects and destroys CD4+ T cells, weakening the immune system and leading to AIDS. It is transmitted through sexual contact, blood transfusions, or from mother to child. While some can suppress the virus for many years, treatment aims to control progression, as there is no cure. HIV evades immunity through antigenic mutations and hiding from antibodies, exploiting the immune system it evolved to overcome. Immunotherapy and antiretroviral drugs target different stages of the viral lifecycle, but combination treatment is required to suppress HIV long-term.
Similar to Determination of Average HIV Replication in the Blood Plasma Using Truncated Logistic Distribution (20)
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The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
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Determination of Average HIV Replication in the Blood Plasma Using Truncated Logistic Distribution
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Determination of Average HIV Replication in
the Blood Plasma Using Truncated Logistic
Distribution
1
G. Meenakshi, 2
Habineza Alexis, 3
R. Lakshmajayam
1,2,3
Department of Statistics, Annamalai University, Annamalai Nagar - 608002, Tamil Nadu, India
Abstract: Many statistical and computational models have been developed to investigate the complexity of HIV
dynamics in the immune response. Most of the models described the viral replication as a system of differential
equation, where the solution of parameters is not easy to obtain. A model of HIV replication where infected cells
undergo through a truncated logistic distribution is proposed. An infected cell is modelled as an individual entity
with certain states and properties. Three simulation approaches are used for implementing the model, conditional
distribution, truncated population mean approaches and sample mean. Simulation results give insights about the
details of HIV replication dynamics inside the cell at the protein level. Therefore the model can be used for future
studies of HIV intracellular replication. It will also promote better understanding of the HIV/AIDS transmission
dynamics, the study will also add to the existing body of knowledge on mathematical application in the field of
epidemiology.
Keywords: Conditional distribution, HIV Dynamic Immune Power, Logistic Distribution, Truncated Distribution.
1. INTRODUCTION
For most people, infection with HIV is the start of a progressive illness that results in death due to the increasing
occurrence of opportunistic infections. The ultimate cause is the progressive degradation of the immune system (the
body's natural defence system that guards against foreign invaders and that includes lymphocytes and antibodies) by the
virus resulting in Acquired Immunodeficiency Syndrome (AIDS) if there is no treatment. HIV damages the immune
system by attacking certain white blood cells called lymphocytes (specifically those called helper T cells). Lymphocytes
normally help to protect the body against invading micro organisms.
When these cells are destroyed, the body loses its ability to fight infection and becomes vulnerable to a variety of
infections and rare cancers that are the hallmarks of AIDS. The interaction between HIV and immune system is more
complex compared to most other infections. While immune a response has the potential to fight the virus, HIV infects
- helper cells (A type of lymphocyte that is involved in the immune response and that is the primary target for the
AIDS virus), which is a central component orchestrating (planning) the generation of specific immune response.
Depending on co-receptor usage, HIV can infect other immune cells, such as macrophages and dendrite cells that are also
involved in the generation of antiviral immunity.
Thus the suboptimal immune responses develop early during the cute phase of infection and can contribute to viral
persistence and to the ability of the virus to mutate and evolve. The infection remains asymptomatic for years before the
virus load sufficiently increases and the population helper cell falls to low level leading to the development of
AIDS. Diseases progression is associated with the evolution of specific viral variant that are more virulent and
pathogenic. While most viruses are attacked by immune system leaving the body with the lifelong immunity, the
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retrovirus known as Lent virus (HIV) is only slowly and partially attacked. It is never wholly eliminated from the body.
Lent viruses are known for having long time between initial infection and the beginning of serious symptoms. That is the
reason as to why many people who are unaware of their HIV infection can unfortunately spread the virus to others
Anderson et.al 1991. HIV is found in the blood, sexual and bodily fluids of an infected person. HIV has a long latency
period that is, it takes considerable time before the body’s immune system can no longer generates the immune response
required to suppress HIV, leading to an intensified replication of the virus Putzel, 2003.
HIV has a physiological impact on the immune system. It targets and infects white blood cells known as - cells
which are part of the immune system. - cells are helper cells produced from precursors in bone marrow and
thymus. When a person has chronic HIV infection, it causes gradual depletion of the - cell pools. In a normal
human being the level of - cells in the peripheral blood is regulated at a level between to
when the - cell count falls below , a person becomes vulnerable to opportunistic infections. -
cells are a primary indicator used to measure progression of HIV infection in an HIV infected person.
It is the loss of - cells that devastate and compromise the host immune system, making the body vulnerable to all
sorts of opportunistic infections, leading to full blown Acquired Immunodeficiency Syndrome (The stage of HIV
infection in which the immune system is so damaged that it can no longer fight off disease), AIDS which is the last stage
of HIV infection Putzel 2003.
The opportunistic infections such as pneumonia, meningitis, cancers and tuberculosis (TB) are the cause of illness or
death. Since its discovery, in 1981 to date more than 25 million people worldwide have died of AIDS related diseases.
The HIV infection is one of the most destructive health crises of modern times, ravaging families and communities
throughout the world, particularly in the developing countries. Countries that have been hard hit by the AIDS epidemic
have seen mortality surge and life expectancy drop in the last decade Ashford 2006. HIV/AIDS have effects on population
size of susceptible population, characteristics, and well-being. Noted so far that current mathematical models in
transmission dynamics of HIV do not incorporate the effects of treatment on the aspect of logistic population growth rate
of susceptible.
Therefore, this study intends to develop an HIV/AIDS statistical model with treatment which leads to logistic population
growth of the susceptible.
2. REVIEW OF LITERATURES ABOUT HIV MODELS
It has been more than three decades that the Human Immunodeficiency Virus (HIV) has reached a pandemic state. The
worldwide emergence of this infectious agent coincided with the advent of new modeling techniques in epidemiology,
e.g., the basic reproductive number R.M. Anderson., and R.M may 1979, but also in evolution, e.g., the adaptive
dynamics framework (Hofbauer, J; Sigmund, K. 1990). Arguably, this was the first time that so many mathematical
approaches have been mobilized to decipher the course of an infection.
Although there can be variations from patient to patient, the course of an HIV infection follows a general pattern Levy,
J.A.1988. The viral load increases exponentially in the first three to six weeks following infection. The cellular immune
response kicks in after one to two weeks followed by the humeral response after four to eight weeks upon infection
Richman, D. D. et.al 2003. This early phase of infection is commonly referred to as the primary infection or initial phase
and shares many similarities with acute infections. With the onset of a cellular immune response, the viral load decreases
and settles to a more or less constant value for several years.
This is the second phase, which is known as the chronic (or asymptomatic) phase. Importantly, even though it might
appear as if the virus is resting in this phase, there in fact is a rapid turnover of infected cells and it is the cellular and the
humeral immune response that keep viral loads to a constant level, which is referred to as the set point viral load
Ho. D. David, et.al 1995. Furthermore, during this chronic phase, the virus within-host diversity increases and the number
of host - cells decrease because they are the primary target of the virus. The third phase or AIDS phase is
characterized by a dramatic loss in -cells and a strong increase of viral load Coombs et.al 1998 showed that viral
titers increase in the AIDS phase and O’Brien et.al 1998, Lyle’s et.al 1999, confirmed this trend in longitudinal studies.
Clinically, the onset of AIDS is defined as the time point at which the - cell count in the blood falls below 200 per
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ml. The AIDS phase also often (but not always) coincides with a shift in the virus population and the emergence of virus
strains that are able to use CXCR4 co-receptors (instead of CCR5 co receptors) and thus a wider range of immune cells
become susceptible to the virus. Because of the fragility of their immune system (low T-cell counts), patients suffer from
a variety of opportunistic infections during the AIDS phase. Furthermore, within-host virus genetic diversity tends to
decrease during this phase.
3. TRANSITIONS INTO AND OUT OF SEX WORKER STATE ARE RELEVANT ONLY TO HIGH
RISK FEMALES
The model specifies that HIV prevalence at time t is a function of the number of new infections that have arisen prior to
time t times the probability that individuals infected at past times have survived through time t
( ) ∫ ( ), ( )- … (1)
where P (t) is prevalence at calendar time t, I(s) is incidence at calendar time s, and F(t) is the probability of dying within t
years of infection. Discussion of one set of models used for the incidence curve I(s) and incubation distribution F(t) and a
method for deriving a maximum likelihood estimate and likelihood bounds on the epidemic parameters, possible
alternatives are also discussed briefly. A discrete analog to equation (1) has been specified, and parametric forms for I (·)
and F (·) have been selected to be consistent with the assumptions used in Epimodel. Specifically, a gamma distribution
has been used for incidence and a Weibull distribution for the cumulative progression rate. The gamma distribution used
here is described by two parameters, and , and has the following form
( )
( )
… (2)
The Weibull distribution is described by two parameters, k and and has the following form
( ) ( )
… (3)
The Weibull distribution has been used frequently to describe the AIDS incubation distribution Brookmeyer et.al 1986,
although the strengths and weaknesses of the model, as well as alternative assumptions, have been examined elsewhere
Marion, et.al 1993. Based on this formulation of the model, the analytical objective is to find the set of model parameters
that are most likely to have produced the observed data on prevalence. Each set of parameter values generates a unique set
of incidence, prevalence and mortality curves. A first round of analysis has been undertaken with the assumption that the
(Absolute Neutro Count) ANC data are representative of national prevalence levels in the adult population, but the
validity of this assumption is considered further below.
It would be possible to specify a likelihood function that depends only on the observed data points, and then maximize
this function to identify the parameter values with the highest relative likelihood given these observations. There are
several reasons, however, why it may be useful or even necessary first to address the problem of missing data values.
First, in the simplest models each observation on prevalence in a particular site and particular year is considered to be
independent of every other site-year observation, more sophisticated models that capture the relationships between
observations within the same site or heterogeneities across the sites would require complete time series for some range of
years in every site. Second, given the large number of missing values relative to observed values in many countries in
sub-Saharan Africa, it may simply be impossible to compute maximum likelihood parameter estimates based only on the
limited number of observations. In these cases, observed values in other sites or in other years for the same sites, as well
as other covariates and information gleaned from other countries, could be helpful in predicting a distribution of likely
values for the unobserved data points.
Third, if the probability that a particular value is missing is correlated with the level of the missing value, this would
produce a bias that might be mitigated by filling in the gaps in the data set. Stated in other words, if the observations that
are available in a particular year tend to come from sites with systematically higher or lower than average prevalence 6
rates, then the conclusions drawn from the incomplete data set will be biased upwards or downwards accordingly.
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The study of viral dynamic models A. S. Perelson, et.al (1993) proposed models of viral spread in the blood stream. The
models consist of four components, such as un infected - cells, latently infected - cells, actively infected
- cells and free virus.
The models are considered as
Where T- HIV virions infect target T cells, - productively infected T cells, -infection virions produced before
initiation of the drug, -non infected virions, C -decay rate of non-infectious virus, N -productively infected T cell
assumed to produce N virions in its life time. The parameters of this model are estimated by non-linear least square
regression method. The estimated parameters of this models are biased, because assumption of imperfect drug. The
estimated life time productively infected T-cells, and plasma virions are1.6 days and 0.24 days respectively.
Louied et.al 2003, proposed the random as well as deterministic model and HIV patient data was illustrated. It is crucial
to include target cell dynamics with density dependent growth but that a latent cell component is not needed over this
shorter time scale.
( ) ( ) ( ) ( ) ( )
( ) ( ) ( )
( ) ( ) 4
( ) ( )
5 ( ) ( ) ( ) ( )
Where is the efficacy of the reverse transcriptase (RT) inhibitor mono-therapy N is the average number of virions
produced per productively infected T-cells.
D.M Bortz and P.W.Nelson 2004 illustrated the wide range of C and small range for undergoing protease inhibitor
therapy by sensitivity methodology in which principle component analysis is used.
D.M Bortz and P.W.Nelson 2005, create a statistical model, a hierarchical mixed effects modeling approach is employed
to characterize the inter- and – intra- individual variability mixed in the patient population. Straight forward
characterization, of the inherent within and between patient variability by the mixed effect modeling, for patient, log
transform of the dimensional vector of viral load measurements and time point is modeled by
( )
where the vector value function represents the solution to the differential equation evaluated at time points and is a
vector random variable observation describing the measurement equation in observing viral roads. -viral clearance rate
and - cells, death rates and illustrated sample variances for maximum likelihood best fit values of the parameters
C and ).
J.Guedj et.al (2007) used the fisher information matrix to check and measure the practical identinfiability of parameters
estimated by Maximum Likelihood Estimation and described the following an HIV dynamics model based on five non-
linear differentials
( )
( )
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( )
Where
-Quiescent cells. In this model, the activation process is probability one of the major cause of - cell depletion
during HIV infection Grossman et.al 2000. In the steady state assumption, the treatment effects are initiated with is
introduced Ribero et.al 2002.
The availability of assays able to distinguish infected and non -infected cells Perelson et.al (1998) as well as infectious
and non-infectious viruses Ruset et.al 2004.
May useful to improve the identinfiability of model parameters and thus usefulness of HIV dynamic model to analyze the
real data.
The estimation of the free virions clearance and the number of virus produced by an infected cell are very difficult by
means of rapid dynamics of these components.
4. MODEL FOR HIV REPLICATION USING TRUNCATED LOGISTIC DISTRIBUTION
In statistics, a truncated distribution is a conditional distribution that results from restricting the domain of some
other probability distribution. Truncated distributions arise in practical statistics in cases where the ability to record, or
even to know about, occurrences is limited to values which lie above or below a given threshold or within a specified
range.
Suppose a random variable X that is distributed according to some probability density function ( ) with cumulative
distribution function ( ) both of which have infinite support. The probability density of the random variable after
restricting the support to be between two constants so that the support ( -
Y is the considered as number of replicated virus in the blood plasma of HIV infected persons. It follows truncated
logistic distribution. Once HIV infected the person, it will replicate from the – cells of infected persons.
The number of replicated virus is varying person to person after infection. It will be increasing nature. Therefore it is
considered as random variable of truncated logistic distribution with range of greater than
A truncated distribution as is as (a, b]
( )
( )
( )
A truncated distribution as is as following
( )
( )
( )
The logistic density function for X where ( ) and is ( ) given
( )
( )
2 ( )3
Where √ (is a scale parameter), such that
Let the density function for
( )
( )
2 ( )3
by definition the truncated density function for y when is given by
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( )
( )
( )
, for
The cumulative distribution function is given by
( )
( )
It follows that
( ) ( )
( )
( )
And the conditional logistic density function is given
( ) ∫
( )
2 ( )3
... (1)
where and
It follows that
( ) ∫ ( )
Since
∫ ( )
∫
Finally
( )
( )
( )2 ( )3
... (2)
5. TRUNCATED MEAN
Suppose the expected value of a random variable distributed according to the density ( ) and a cumulative distribution
of ( ) given that the random variable X, is greater than some known value y. The expectation of a truncated random
variable is thus
( )
∫ ( )
( )
Since ( ) ( ) for all and ( ) elsewhere
The derivative of ( ) proceeds as follows
( )
∫ ( )
( )
( ) ∫
( )
2 ( )3
Since then,
( ) ∫ ( ) * +
( ) ∫ * +
( ) ∫ * +
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( ) ∫ * +
( ) ∫ * +
∫ * +
∫
* +
( )
( ) ( )
Consider and go through integration by part
∫ * +
where and * +
,
* +
∫ * +
∫ * +
* + * +
where * +
∫ * +
,
∫ * +
∫ ( )
since
∫
( )
∫ ∫
∫ ∫ ( )
∫ * +
( ) ( )
Where * +
( )
( )
0 ( ) 1
( )
0 1
( )
( )
( | |)
( )
( )
( ) . . // ( ) ( ) ( )
Since, ( )
Let y be a random variable as number of HIV replication per period (in 1 to 10 years) of infected persons. Testing our
truncated ( ) whether it is unbiased or not by using the various sample sizes (viral load per period).The sample
mean and sample size are fitted in the ( ), this prove that sample mean is unbiased estimate of population mean
when the distribution is truncated as it is shown below. Using this truncated distribution to find the posterior distribution
and posterior mean.
The following observations are considered as HIV replications per period of various infected persons
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Table.1
Sample Size Viral load per ml period
25 30 32 50 42
20 28 33 47 50 57 41 60 61 64
15 57 50 67 53 49 54 59 55 32 29 35 38 47 37
40 55 63 37 25 90 55 61 47 46 33 30 22 65 70 22 31 45 76 80
16 79 86 18 34 22 13 33 29 46 18 12 10 11 25 15 24 20 19 21 35 55
49 56 28
Where are different sample sizes of infected persons,
The conditional average number HIV replications is given by
( ) . . // ( ) ( ) ( )
Since, ( )
4 5( )
The following results obtained
( ) ( )
35.8 8.9 0.018 82.13
46.1 14.41 0.037 90.78
45.13 1329 0.031 66.28
49.65 19.62 0.067 66.85
30.96 19.99 0.138 48.94
Figure: 1
0.018
0.037
0.031
0.067
0.138
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
5 10 15 20 25
P(Y/y>0)
(ProbabilityofReplication)
n (number of infected persons)
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Figure: 3
Figure: 4
Where sample mean ̅ is used as and sample ( ̅) as . The above table shows that the sample mean is unbiased
estimate of population mean, within a time period the probability of HIV replication in the absence of treatment or ART is
above 85% this implies that the HIV dynamic replication follows the truncated logistic distribution.
6. CONCLUSION
In the situation of not yet finding medicine to cure the HIV infection, the study of HIV replication and lymphocytes
damages are very important. Lymphocytes damages are very much affect our immune system to increase HIV replication
always in the human body. In this position measuring viral load and damaged -cells for future period is very much
essential to suggest the medicine for further period to prolong the human life time. Therefore this model is very much
useful to prediction of HIV replication for future period. Further this research is useful in various discipline to production
concept.
2.7E-07
3.98E-05
0.000019
0.00049
0.00141
0
0.0002
0.0004
0.0006
0.0008
0.001
0.0012
0.0014
0.0016
5 10 15 20 25
P(y/y>0)
(ProbabilityofReplication)
n (number of infected persons)
958.03
719.74
760.95
574.52
444.21
0
200
400
600
800
1000
1200
5 10 15 20 25
E(y/y>0)
Expectednumberofvirus
n (number of infected persons)
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