Sample records for contagious disease spread

  1. The effect of travel restrictions on the spread of a moderately contagious disease

    PubMed Central

    Camitz, Martin; Liljeros, Fredrik

    2006-01-01

    Background Much research in epidemiology has been focused on evaluating conventional methods of control strategies in the event of an epidemic or pandemic. Travel restrictions are often suggested as an efficient way to reduce the spread of a contagious disease that threatens public health, but few papers have studied in depth the effects of travel restrictions. In this study, we investigated what effect different levels of travel restrictions might have on the speed and geographical spread of an outbreak of a disease similar to severe acute respiratory syndrome (SARS). Methods We used a stochastic simulation model incorporating survey data of travel patterns between municipalities in Sweden collected over 3 years. We tested scenarios of travel restrictions in which travel over distances >50 km and 20 km would be banned, taking into account different levels of compliance. Results We found that a ban on journeys >50 km would drastically reduce the speed and geographical spread of outbreaks, even when compliance is < 100%. The result was found to be robust for different rates of intermunicipality transmission intensities. Conclusion This study supports travel restrictions as an effective way to mitigate the effect of a future disease outbreak. PMID:17166291

  2. [Significant contagious diseases which spread primarily through livestock trade and products of animal origin].

    PubMed

    Bätza, H J

    2001-08-01

    Against the background of the certification system based on trust, an overview is given of the risk potential posed by the introduction of major animal diseases using tables setting out live animals and livestock products moved and/or imported into Germany as well as maps on the global occurrence of selected diseases figuring on List A of O.I.E. PMID:11560115

  3. Childhood Contagious Diseases

    MedlinePLUS

    ... in children. Hand-Foot-and-Mouth Disease Hand-foot-and-mouth disease is a suddenly appearing (acute), self-limited viral disease caused by viruses of the enterovirus group, particularly Coxsackievirus A16. The ...

  4. The role of contagious disease in udder health

    PubMed Central

    Barkema, H. W.; Green, M. J.; Bradley, A. J.; Zadoks, R. N.

    2009-01-01

    Contagious diseases are a threat to animal health and productivity, both nationally and at the farm level. This makes implementation of biosecurity measures to prevent their introduction and spread within countries and farms a necessity. Mastitis is the most common and costly contagious disease affecting dairy farms in the western world. The major mastitis pathogens are endemic in most countries, and biosecurity measures to prevent introduction and transmission must therefore be implemented at farm level. The 40-yr-old mastitis control plan remains a solid foundation to prevent the spread of contagious intramammary infections. Contagious diseases that do not affect the mammary gland directly may have an indirect effect on mastitis. This is true for list A diseases such as foot and mouth disease, for which biosecurity measures may need to be taken at national level, and for other infections with nonmastitis pathogens such as bovine viral diarrhea virus and Mycobacterium avium ssp. paratuberculosis. Maintaining a closed herd decreases the risk of introduction of pathogens that affect udder health directly or indirectly. If animals are purchased, their udder health history should be evaluated and they should be examined and tested for contagious diseases. Transmission of infections by and to humans and nonbovine animals may occur. Contact with visitors and nonbovine animals should therefore be minimized. Because of globalization and heightened consumer awareness, the importance of biosecurity now supersedes individual farms, and increased pressure to control transmission of contagious diseases can be expected at industry or government levels in western countries and elsewhere. PMID:19762787

  5. Invited review: The role of contagious disease in udder health.

    PubMed

    Barkema, H W; Green, M J; Bradley, A J; Zadoks, R N

    2009-10-01

    Contagious diseases are a threat to animal health and productivity, both nationally and at the farm level. This makes implementation of biosecurity measures to prevent their introduction and spread within countries and farms a necessity. Mastitis is the most common and costly contagious disease affecting dairy farms in the western world. The major mastitis pathogens are endemic in most countries, and biosecurity measures to prevent introduction and transmission must therefore be implemented at farm level. The 40-yr-old mastitis control plan remains a solid foundation to prevent the spread of contagious intramammary infections. Contagious diseases that do not affect the mammary gland directly may have an indirect effect on mastitis. This is true for list A diseases such as foot and mouth disease, for which biosecurity measures may need to be taken at national level, and for other infections with nonmastitis pathogens such as bovine viral diarrhea virus and Mycobacterium avium ssp. paratuberculosis. Maintaining a closed herd decreases the risk of introduction of pathogens that affect udder health directly or indirectly. If animals are purchased, their udder health history should be evaluated and they should be examined and tested for contagious diseases. Transmission of infections by and to humans and nonbovine animals may occur. Contact with visitors and nonbovine animals should therefore be minimized. Because of globalization and heightened consumer awareness, the importance of biosecurity now supersedes individual farms, and increased pressure to control transmission of contagious diseases can be expected at industry or government levels in western countries and elsewhere. PMID:19762787

  6. Educating Children and Youth To Prevent Contagious Disease. ERIC Digest.

    ERIC Educational Resources Information Center

    Grosse, Susan J.

    Twenty-first century contagious diseases require more than basic health lessons to prevent transmission. This Digest examines ways to prevent disease transmission in school settings. Section 1 discusses key concepts in contagion education: all people are potentially contagious; germs that cause diseases are present on many parts of the body; hand…

  7. Prevent the Spread of Zoonotic Diseases 

    E-print Network

    Pena, Josefa

    2008-11-10

    , and equipment can reduce the risk of exposing other animals or people to contagious diseases. Wear boots and a set of protective clothing that you wear only when ? handling and caring for animals. Examples are hat ? coveralls ? long-sleeved shirt (cotton.... Wash Your Hands Washing your hands is the single most important thing you can do to prevent contagious diseases from spreading. Follow these basic hand-washing tech- niques to properly remove disease-causing germs. How to wash your hands Use warm...

  8. Interdisciplinary approaches in epidemic studies--II: Four geographic models of the flow of contagious disease.

    PubMed

    Angulo, J J

    1987-01-01

    Straightforward adaptation of geographical and regional-science models to conceptual modeling of the epidemic spread of a contagious disease is achieved by: using analogies and isomorphisms, and using as a real example the observations made during a well studied epidemic of variola minor (the mild form of smallpox), a typical contagious disease. The adaptation of the Wilson model of planning for urban development includes a static view (network) of the structure and activities of the population and of organizations (diffusion agencies such as day schools), and the dynamic view (mechanism of epidemic spread) which includes the changes with time of elements of the network brough by flow of disease. Adaptation of the Brown model of spatial diffusion yields flows of disease occurring between micro-scale units (households) of social interactions but aggregations of these units do not participate explicitly in the flows. The occurrence of successive generations of affected households is specified as well as the occurrence of definite stages of the epidemic progression. Adaptation of the Alves-Morrill model of spatial diffusion yields a network of social groups and interdependencies; a simplified network of the mechanism of spread that shows flows of disease between individuals grouped into generations of infected individuals and generations of infective individuals; and a more realistic view which shows the flows of disease between real epidemiological units such as households and school classes. Adaptation of the Morrill-Manninen model of spatial diffusion concentrates on the mechanism and parameters having the epidemic spread as output. The interdependencies between the parameters and between each parameter and the epidemic spread are represented, including feedback processes. Brown's model seems to be the best for describing the epidemic spread of contagious disease while the Morrill-Manninen model is the most promising for investigating the detailed mechanism of the spread. Since these two models complement each other, their combined use is indicated. PMID:3823998

  9. What To Do When Contagious Disease Strikes Your School.

    ERIC Educational Resources Information Center

    American Bar Association, Chicago, IL.

    This publication presents 10 documents collected to accompany a seminar entitled "What To Do When Contagious Disease Strikes Your School," presented at the 31st annual convention of the National Organization on Legal Problems of Education in 1985. The materials include (1) an agenda of the seminar listing the speakers, their topics, and the time…

  10. 9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...contagious, infectious, or communicable disease, it becomes necessary to...

  11. MHC gene copy number variation in Tasmanian devils: implications for the spread of a contagious cancer

    PubMed Central

    Siddle, Hannah V.; Marzec, Jolanta; Cheng, Yuanyuan; Jones, Menna; Belov, Katherine

    2010-01-01

    Tasmanian devils face extinction owing to the emergence of a contagious cancer. Devil facial tumour disease (DFTD) is a clonal cancer spread owing to a lack of major histocompatibility complex (MHC) barriers in Tasmanian devil populations. We present a comprehensive screen of MHC diversity in devils and identify 25 MHC types and 53 novel sequences, but conclude that overall levels of MHC diversity at the sequence level are low. The majority of MHC Class I variation can be explained by allelic copy number variation with two to seven sequence variants identified per individual. MHC sequences are divided into two distinct groups based on sequence similarity. DFTD cells and most devils have sequences from both groups. Twenty per cent of individuals have a restricted MHC repertoire and contain only group I or only group II sequences. Counterintuitively, we postulate that the immune system of individuals with a restricted MHC repertoire may recognize foreign MHC antigens on the surface of the DFTD cell. The implication of these results for management of DFTD and this endangered species are discussed. PMID:20219742

  12. [Highly contagious diseases with human-to-human transmission].

    PubMed

    Rybka, Aleš; Szanyi, Juraj; Kapla, Jaroslav; Plíšek, Stanislav

    2012-12-01

    Highly contagious diseases are caused by various biological agents that pose a risk to individuals and may have a potential for public health impact. They result in high mortality and morbidity rates, might cause public panic and therefore require special measures. The pathogens that can be easily disseminated or transmitted from person to person are the riskiest for clinicians (Ebola virus, Marburg virus, Lassa virus, Crimean-Congo hemorrhagic fever virus, Variola major, SARS virus and Yersinia pestis). Human-to-human transmission has not been confirmed for the other biological agents and therefore they pose a very low risk for population. PMID:23386507

  13. Epidemiology: Understanding Disease Spread

    NSDL National Science Digital Library

    Marion Fass (Beloit College; Biology)

    2006-05-20

    Factors that influence disease spread throughout populations can be explored with the program Epidemiology. Both population and disease characteristics can be modeled over different time periods. The Susceptible- Infected- Recovered (SIR) model enables us to make predictions based on significant variables such as the flow of new susceptibles in to the population, transmission rates, disease deaths, and the duration of the disease. Ebola is used as a model organism and epidemiology is presented from both a microbiological and social perspective. * build epidemiological models of different diseases, design strategies for disease control, and test the effectiveness of these strategies on virtual populations

  14. [Structural requirements for the management of patients with highly contagious life-threatening infectious diseases: update 2015].

    PubMed

    Grünewald, Thomas

    2015-07-01

    The care of highly contagious life-threatening infectious diseases (HLID) requires specialized treatment facilities that are capable of strict isolation measures and appropriate medical treatment. The German approach to the management of these diseases, which is maintained by the Permanent Working Group of Medical Competence and Treatment Centers for Highly Contagious and Life-Threatening Diseases (STAKOB) is adjusted in the present publication with regards to recent experiences and upcoming needs. Clear synergies in using infrastructures and bundling of resources have led to similar efforts at the European level. The German concept, therefore, has a pioneering role. This update is intended to improve professional patient care and also minimize the risk of disease spread and transmission. PMID:26099224

  15. Contagious caprine pleuropneumonia: new aspects of an old disease.

    PubMed

    Nicholas, R; Churchward, C

    2012-06-01

    Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. capripneumoniae, is a serious OIE-listed disease affecting goats in the Middle East, north and east Africa and Asia. Mortality and morbidity rates can be as high as 60% and 90%, respectively, when the disease first enters a territory, invariably through carrier animals. Recent detections of CCPP in Pakistan and Tajikistan are probably the result of improved diagnosis as the disease has been suspected there for many years, while those in Thrace in 2003 and Mauritius in 2009 represent new outbreaks. CCPP was thought to be highly host specific until recent outbreaks in wildlife species including gazelles and gerenuks show that the causative mycoplasma has broader specificity. Diagnosis was hampered by the fastidiousness of the causative mycoplasma but molecular-based tests like PCR have greatly improved detection. Rapid latex agglutination tests that can be performed at the penside are also available for antibody detection. Clinically affected animals respond to a range of antibiotics although it is unlikely that this results in complete elimination of the mycoplasma. Vaccines consisting of saponized organisms have been shown to be protective but the quality and efficacy may be variable. PMID:21951488

  16. A Framework for Categorization of the Economic Impacts of Outbreaks of Highly Contagious Livestock Diseases.

    PubMed

    Saatkamp, H W; Mourits, M C M; Howe, K S

    2014-11-01

    A framework for categorization of economic impacts of outbreaks of highly contagious livestock diseases (HCLD) is presented. This framework interprets veterinary measures to control HCLD outbreaks with reference to economic definitions of costs and benefits, and the implications for value losses both for different stakeholders affected and society as a whole. Four cost categories are identified, that is virus control-related direct costs (DC), spread prevention and zoning-related direct consequential costs (DCC), market and price disruption-related costs during (indirect consequential costs, ICC) and after the outbreak (aftermath costs, AC). The framework is used to review existing literature on cost estimation for different stakeholders. This review shows considerable differences between studies, making comparison of results difficult and susceptible to misunderstanding. It is concluded that the framework provides a logical basis for all future analyses of the economic impacts of HCLD. PMID:25382248

  17. Finding Evidence for Local Transmission of Contagious Disease in Molecular Epidemiological Datasets

    PubMed Central

    Ypma, Rolf J. F.; Donker, Tjibbe; van Ballegooijen, W. Marijn; Wallinga, Jacco

    2013-01-01

    Surveillance systems of contagious diseases record information on cases to monitor incidence of disease and to evaluate effectiveness of interventions. These systems focus on a well-defined population; a key question is whether observed cases are infected through local transmission within the population or whether cases are the result of importation of infection into the population. Local spread of infection calls for different intervention measures than importation of infection. Besides standardized information on time of symptom onset and location of cases, pathogen genotyping or sequencing offers essential information to address this question. Here we introduce a method that takes full advantage of both the genetic and epidemiological data to distinguish local transmission from importation of infection, by comparing inter-case distances in temporal, spatial and genetic data. Cases that are part of a local transmission chain will have shorter distances between their geographical locations, shorter durations between their times of symptom onset and shorter genetic distances between their pathogen sequences as compared to cases that are due to importation. In contrast to generic clustering algorithms, the proposed method explicitly accounts for the fact that during local transmission of a contagious disease the cases are caused by other cases. No pathogen-specific assumptions are needed due to the use of ordinal distances, which allow for direct comparison between the disparate data types. Using simulations, we test the performance of the method in identifying local transmission of disease in large datasets, and assess how sensitivity and specificity change with varying size of local transmission chains and varying overall disease incidence. PMID:23922835

  18. Contagious Equine Metritis: A Review

    PubMed Central

    Eaglesome, M. D.; Garcia, M. M.

    1979-01-01

    Contagious equine metritis is a highly contagious genital infection of mares, spread venereally, and was first described in 1977. Although most contagious equine metritis outbreaks involved Thoroughbreds, infection in other breeds has also occurred. The disease has been reported in Europe, Australia and the United States. In Canada, contagious equine metritis has been designated a reportable disease under the Animal Disease and Protection Act. Contagious equine metritis is characterized by an endometritis and infertility and infected mares show no signs of systemic infection. Clinical signs have not been observed in stallions. An asymptomatic carrier state exists in both mares and stallions. Infected mares respond clinically to the topical and parenteral administration of antibacterial drugs. However, a proportion of mares remain carriers of the contagious equine metritis organism. Treatment of stallions is successful. Haemophilus equigenitalis has been proposed as the species name of the Gram-negative, microaerophilic coccobacillus. Sample collection and laboratory methods for the diagnosis of contagious equine metritis are described. PMID:389400

  19. [The first Polish animal contagious disease act of 1844].

    PubMed

    Frymus, T; Tropi?o, J

    1991-05-01

    The Veterinary Control Act of 1844 was the first to regulate in entirety the control of infectious diseases in animals and questions of sanitary inspection of animal food products in the Kingdom of Poland. The act listed explicit procedures regarding diagnostics, control and eradication of diseases as well as concerning animal food product inspection. The act required that animal owners become familiar with symptoms of animal diseases, their methods of control and that they prevent their spreading. The obligations of veterinarians, state physicians and administrative control bodies in the control of animal diseases were specified by the act. Besides the main text on the control of diseases and meat inspection the act also contains elements of food law, some norms concerning public law and order (e.g. requirements concerning dogs) and even some regulations on animal protection. PMID:1874138

  20. [Management of highly contagious, life-threatening infectious diseases in Germany].

    PubMed

    Gottschalk, René

    2015-07-01

    Highly contagious, life-threatening infectious diseases are extremely rare in Germany. It was estimated that Germany experiences approximately one such patient per year, but records since the year 2000 demonstrate that this has not been the case (six cases). Even during the current Ebola outbreak in West Africa, Germany is not experiencing patients-apart from those referred to by international organisations. However, it is necessary to establish and maintain specialised treatment centres for patients with highly contagious, life-threatening diseases. Highly contagious, life-threatening diseases are rare and neglected diseases, yet they can have devastating effects on individual patients, societies and entire economies. A dedicated expert group was formed at the German Robert Koch Institute (STAKOB) to network and synthesise the different centres of competence and treatment. This group prepares recommendations that encompass the early detection and treatment of patients to infectious disease management to mitigate the implications on societies and interrupt the chain of infections to safeguard the integrity of public health in Germany. PMID:25963639

  1. Global Spread of Infectious Diseases

    E-print Network

    S. Hsu; A. Zee

    2003-06-25

    We develop simple models for the global spread of infectious diseases, emphasizing human mobility via air travel and the variation of public health infrastructure from region to region. We derive formulas relating the total and peak number of infections in two countries to the rate of travel between them and their respective epidemiological parameters.

  2. Contagious Diseases in Competitive Sport: What Are the Risks?

    ERIC Educational Resources Information Center

    Dorman, John M.

    2000-01-01

    Discusses fungal, bacterial, and viral infections that may strike athletes during competition, highlighting possible risks of hepatitis, herpes, and HIV. Athletes generally are more at risk off the playing field than while competing. Requiring immunizations against measles and hepatitis B prior to college admission would eliminate two diseases.…

  3. The canine contagious respiratory disease complex (kennel cough).

    PubMed

    Appel, M; Bemis, D A

    1978-01-01

    Several infectious agents are involved in the kennel cough complex in dogs. They include canine parainfluenza virus (SV5), canine adenovirus 2, Bordetella bronchiseptica, and possibly several mycoplasma species. The importance of each of these agents in the disease syndrome is discussed as well as possible prevention or treatment. PMID:204455

  4. A generic model of contagious disease and its application to human-to-human transmission of avian influenza.

    SciTech Connect

    Hirsch, Gary B.

    2007-03-01

    Modeling contagious diseases has taken on greater importance over the past several years as diseases such as SARS and avian influenza have raised concern about worldwide pandemics. Most models developed to consider projected outbreaks have been specific to a single disease. This paper describes a generic System Dynamics contagious disease model and its application to human-to-human transmission of a mutant version of avian influenza. The model offers the option of calculating rates of new infections over time based either on a fixed ''reproductive number'' that is traditional in contagious disease models or on contact rates for different sub-populations and likelihood of transmission per contact. The paper reports on results with various types of interventions. These results suggest the potential importance of contact tracing, limited quarantine, and targeted vaccination strategies as methods for controlling outbreaks, especially when vaccine supplies may initially be limited and the efficacy of anti-viral drugs uncertain.

  5. Evolution of a contagious cancer: epigenetic variation in Devil Facial Tumour Disease

    PubMed Central

    Ujvari, Beata; Pearse, Anne-Maree; Peck, Sarah; Harmsen, Collette; Taylor, Robyn; Pyecroft, Stephen; Madsen, Thomas; Papenfuss, Anthony T.; Belov, Katherine

    2013-01-01

    The emergence of Devil Facial Tumour Disease (DFTD), a highly contagious cancer, is driving Tasmanian devils (Sarcophilus harrisii) to extinction. The cancer is a genetically and chromosomally stable clonal cell line which is transmitted by biting during social interactions. In the present study, we explore the Devil Facial Tumour (DFT) epigenome and the genes involved in DNA methylation homeostasis. We show that tumour cells have similar levels of methylation to peripheral nerves, the tissue from which DFTD originated. We did not observe any strain or region-specific epimutations. However, we revealed a significant increase in hypomethylation in DFT samples over time (p < 0.0001). We propose that loss of methylation is not because of a maintenance deficiency, as an upregulation of DNA methyltransferase 1 gene was observed in tumours compared with nerves (p < 0.005). Instead, we believe that loss of methylation is owing to active demethylation, supported by the temporal increase in MBD2 and MBD4 (p < 0.001). The implications of these changes on disease phenotypes need to be explored. Our work shows that DFTD should not be treated as a static entity, but rather as an evolving parasite with epigenetic plasticity. Understanding the role of epimutations in the evolution of this parasitic cancer will provide unique insights into the role of epigenetic plasticity in cancer evolution and progression in traditional cancers that arise and die with their hosts. PMID:23135679

  6. [Epidemiology of Ebola virus disease and of other highly contagious, life-threatening diseases with low incidence in Germany].

    PubMed

    Ehlkes, L; Kreuels, B; Schwarz, N G; May, Jürgen

    2015-07-01

    Apart from sporadic exported cases, the occurrence of Ebola, Marburg and Lassa virus diseases is limited to the African continent. Crimean-Congo Hemorrhagic Fever occurs in Southeastern Europe but, so far, not in Germany. Other hemorrhagic fever disease-viruses occur in distinct regions in South America. Pulmonary plague is the bacterial infectious disease with the most contagious and lethal course and it is endemic to Madagascar and East Africa, but also occurs in other countries (e.g. India, USA). Monkey pox epidemics have occurred in remote areas of the Congo Basin. Such outbreaks could potentially become more common with the discontinuation of the cross-protective smallpox vaccination. The Severe Acute Respiratory Syndrome (SARS) that emerged in 2002/2003 is another pathogen with significant epidemic potential. Typical for these diseases is a natural circulation between reservoir animals in remote areas. Sporadic transmission to humans can occur through contact with an infected animal. Subsequent human-to-human transmission can lead to epidemics, such as the current outbreak of Ebola virus disease in West Africa. PMID:25997608

  7. SIR Model for Spread of Disease

    NSDL National Science Digital Library

    David Smith

    Using Maple, Mathmatica, or MatLab, learner should be able to develop the SIR Model for the spread of an infectious disease, including the concepts of contact number and herd immunity; to develop a version of Eulers Method for solving a system of differential equations.

  8. Do astrocytes collaborate with neurons in spreading the "infectious" a? and Tau drivers of Alzheimer's disease?

    PubMed

    Dal Prŕ, Ilaria; Chiarini, Anna; Gui, Li; Chakravarthy, Balu; Pacchiana, Raffaella; Gardenal, Emanuela; Whitfield, James F; Armato, Ubaldo

    2015-02-01

    Evidence has begun emerging for the "contagious" and destructive A?42 (amyloid-beta42) oligomers and phosphorylated Tau oligomers as drivers of sporadic Alzheimer's disease (AD), which advances along a pathway starting from the brainstem or entorhinal cortex and leading to cognition-related upper cerebral cortex regions. Seemingly, A?42 oligomers trigger the events generating the neurotoxic Tau oligomers, which may even by themselves spread the characteristic AD neuropathology. It has been assumed that only neurons make and spread these toxic drivers, whereas their associated astrocytes are just janitorial bystanders/scavengers. But this view is likely to radically change since normal human astrocytes freshly isolated from adult cerebral cortex can be induced by exogenous A?25-35, an A?42 proxy, to make and secrete increased amounts of endogenous A?42. Thus, it would seem that the steady slow progression of AD neuropathology along specific cognition-relevant brain networks is driven by both A?42 and phosphorylated Tau oligomers that are variously released from increasing numbers of "contagion-stricken" members of tightly coupled neuron-astrocyte teams. Hence, we surmise that stopping the oversecretion and spread of the two kinds of "contagious" oligomers by such team members, perhaps via a specific CaSR (Ca(2+)-sensing receptor) antagonist like NPS 2143, might effectively treat AD. PMID:24740577

  9. Social Distancing Strategies against Disease Spreading

    NASA Astrophysics Data System (ADS)

    Valdez, L. D.; Buono, C.; Macri, P. A.; Braunstein, L. A.

    2013-12-01

    The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, i.e., the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, i.e., the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.

  10. Social distancing strategies against disease spreading

    NASA Astrophysics Data System (ADS)

    Valdez, L. D.; Buono, C.; Macri, P. A.; Braunstein, L. A.

    2014-03-01

    The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, i.e, the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, i.e, the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.

  11. The SIR Model for Spread of Disease

    NSDL National Science Digital Library

    Moore, Lang

    Created by Lang Moore and David Smith for the Connected Curriculum Project, the purpose of this module is to develop the SIR Model for the spread of an infectious disease, including the concepts of contact number and herd immunity; to develop a version of Euler's Method for solving a system of differential equations. This is one lesson within a larger set of learning modules hosted by Duke University.

  12. Disease spreading in real-life networks

    NASA Astrophysics Data System (ADS)

    Gallos, Lazaros; Argyrakis, Panos

    2002-08-01

    In recent years the scientific community has shown a vivid interest in the network structure and dynamics of real-life organized systems. Many such systems, covering an extremely wide range of applications, have been recently shown to exhibit scale-free character in their connectivity distribution, meaning that they obey a power law. Modeling of epidemics on lattices and small-world networks suffers from the presence of a critical infection threshold, above which the entire population is infected. For scale-free networks, the original assumption was that the formation of a giant cluster would lead to an epidemic spreading in the same way as in simpler networks. Here we show that modeling epidemics on a scale-free network can greatly improve the predictions on the rate and efficiency of spreading, as compared to lattice models and small-world networks. We also show that the dynamics of a disease are greatly influenced by the underlying population structure. The exact same model can describe a plethora of networks, such as social networks, virus spreading in the Web, rumor spreading, signal transmission etc.

  13. Spread of epidemic disease on networks

    NASA Astrophysics Data System (ADS)

    Newman, M. E.

    2002-07-01

    The study of social networks, and in particular the spread of disease on networks, has attracted considerable recent attention in the physics community. In this paper, we show that a large class of standard epidemiological models, the so-called susceptible/infective/removed (SIR) models can be solved exactly on a wide variety of networks. In addition to the standard but unrealistic case of fixed infectiveness time and fixed and uncorrelated probability of transmission between all pairs of individuals, we solve cases in which times and probabilities are nonuniform and correlated. We also consider one simple case of an epidemic in a structured population, that of a sexually transmitted disease in a population divided into men and women. We confirm the correctness of our exact solutions with numerical simulations of SIR epidemics on networks.

  14. Spread of infectious disease through clustered populations

    PubMed Central

    Miller, Joel C.

    2009-01-01

    Networks of person-to-person contacts form the substrate along which infectious diseases spread. Most network-based studies of this spread focus on the impact of variations in degree (the number of contacts an individual has). However, other effects such as clustering, variations in infectiousness or susceptibility, or variations in closeness of contacts may play a significant role. We develop analytic techniques to predict how these effects alter the growth rate, probability and size of epidemics, and validate the predictions with a realistic social network. We find that (for a given degree distribution and average transmissibility) clustering is the dominant factor controlling the growth rate, heterogeneity in infectiousness is the dominant factor controlling the probability of an epidemic and heterogeneity in susceptibility is the dominant factor controlling the size of an epidemic. Edge weights (measuring closeness or duration of contacts) have impact only if correlations exist between different edges. Combined, these effects can play a minor role in reinforcing one another, with the impact of clustering the largest when the population is maximally heterogeneous or if the closer contacts are also strongly clustered. Our most significant contribution is a systematic way to address clustering in infectious disease models, and our results have a number of implications for the design of interventions. PMID:19324673

  15. Atmospheric Spread of Foot-and-mouth Disease During The Early Phase of The Uk Epidemic 2001

    NASA Astrophysics Data System (ADS)

    Sřrensen, J. H.; Mikkelsen, T.; Astrup, P.; Alexandersen, S.; Donaldson, A. I.

    Foot-and-mouth disease (FMD) is a highly contagious viral disease in cloven-hoofed domesticated and wild animals. The highly contagious nature of FMD is a reflection of the wide range of species which are susceptible, the enormous quantities of virus liberated by infected animals, the range of excretions and secretions which can be infectious, the stability of the virus in the environment, the multiplicity of routes of infection and the very small doses of virus that can initiate infection in susceptible hosts. One of the routes for the spread of the disease is the atmospheric dispersion of virus exhaled by infected animals. Such spread can be rapid and extensive, and it is known in certain circumstances to have occurred over a distance of several hundred kilometres. For the FMD epidemic in UK in 2001, atmospheric dispersion models were applied in real time in order to describe the atmospheric dispersion of virus for the larger outbreaks of the disease. The operational value of such modelling is first of all to identify risk zones, which is helpful to the emergency management. The paper addresses the modelling techniques and presents results related with the epidemic in UK in 2001.

  16. How Long Is Mono Contagious?

    MedlinePLUS

    ... for Parents for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q&A School & Jobs Drugs & Alcohol Staying Safe Recipes En Espańol ... Guy's Guide to Body Image How Long Is Mono Contagious? KidsHealth > Teens > ...

  17. A Cellular Automaton Framework for Infectious Disease Spread Simulation

    PubMed Central

    Pfeifer, Bernhard; Kugler, Karl; Tejada, Maria M; Baumgartner, Christian; Seger, Michael; Osl, Melanie; Netzer, Michael; Handler, Michael; Dander, Andreas; Wurz, Manfred; Graber, Armin; Tilg, Bernhard

    2008-01-01

    In this paper, a cellular automaton framework for processing the spatiotemporal spread of infectious diseases is presented. The developed environment simulates and visualizes how infectious diseases might spread, and hence provides a powerful instrument for health care organizations to generate disease prevention and contingency plans. In this study, the outbreak of an avian flu like virus was modeled in the state of Tyrol, and various scenarios such as quarantine, effect of different medications on viral spread and changes of social behavior were simulated. The proposed framework is implemented using the programming language Java. The set up of the simulation environment requires specification of the disease parameters and the geographical information using a population density colored map, enriched with demographic data. The results of the numerical simulations and the analysis of the computed parameters will be used to get a deeper understanding of how the disease spreading mechanisms work, and how to protect the population from contracting the disease. Strategies for optimization of medical treatment and vaccination regimens will also be investigated using our cellular automaton framework. In this study, six different scenarios were simulated. It showed that geographical barriers may help to slow down the spread of an infectious disease, however, when an aggressive and deadly communicable disease spreads, only quarantine and controlled medical treatment are able to stop the outbreak, if at all. PMID:19415136

  18. Techniques for Preventing the Spread of Infectious Diseases.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    Specific procedures are outlined for prevention of the spread of infectious diseases with techniques of handwashing, diapering, and handling of known disease carriers. Protocols for classroom cleanliness list essential steps and key points and precautions for maintaining a hygienic environment. This section includes a list of protocols for food…

  19. Global Transport Networks and Infectious Disease Spread

    PubMed Central

    Tatem, A.J.; Rogers, D.J.; Hay, S.I.

    2011-01-01

    Air, sea and land transport networks continue to expand in reach, speed of travel and volume of passengers and goods carried. Pathogens and their vectors can now move further, faster and in greater numbers than ever before. Three important consequences of global transport network expansion are infectious disease pandemics, vector invasion events and vector-borne pathogen importation. This review briefly examines some of the important historical examples of these disease and vector movements, such as the global influenza pandemics, the devastating Anopheles gambiae invasion of Brazil and the recent increases in imported Plasmodium falciparum malaria cases. We then outline potential approaches for future studies of disease movement, focussing on vector invasion and vector-borne disease importation. Such approaches allow us to explore the potential implications of international air travel, shipping routes and other methods of transport on global pathogen and vector traffic. PMID:16647974

  20. Risk of Disease Spread through Bioterrorism

    SciTech Connect

    Weller, Richard E.

    2006-08-01

    Bioterrorism is seen as a clear and present danger, although historically, acts of bioterrorism have been relatively unpredictable, rare and, thus far, small-scale events. The risk of an event is elevated by increasing contact among species and a global connectivity that provides rapid dissemination of infectious diseases regardless of origin. Virtually any pathogenic microbe could be used by bioterrorists. An attack may be difficult to distinguish from a naturally occurring infectious disease outbreak; however, consequences are likely to be similar. The U.S. agricultural sector is extremely vulnerable to bioterrorist attacks because our animals and plants have little or no innate resistance to foreign pathogens and are not vaccinated or otherwise protected against these diseases. It is also important to note that weapons or delivery systems are not an issue because the animals and plants themselves are the primary vector for transferring agents. Most bioterrorism agents are zoonotic in origin, thus an attack on animal populations could pose a health risk to humans. Additionally, disease outbreaks resulting from bioterrorism could jump to wildlife species, persist in the environment, replace locally adapted enzootic strains, expand their range, or emerge as a new zoonotic disease in naďve human and animal populations.

  1. Immunization of Sheep and Goats Against Soremouth (Contagious Ecthyma). 

    E-print Network

    Boughton, I. B. (Ivan Bertrand); Hardy, W. T. (William Tyree)

    1935-01-01

    of Azriculture. tin coaieration with . Texas - _Extension ... Service. . ,, shc by ! of OC( unc hec the 10s nPP lea 1 a sl Mo --- vat exc 1 +ma C II x the sor sev Contagious ecthyma (soremouth) is an infectious disease of ?ep and goats..., 1935 IMMUNIZATION OF SHEEP AND GOATS AGAINST SOREMOUTH (Contagious Ecthyma) Contagious ecthyma is an infectious disease of sheep and goats caused by a filterable virus and characterized by the formation of papules, vesicles, pustules, and scabs...

  2. Soremouth (Contagious Ecthyma) in Sheep and Goats. 

    E-print Network

    Schmidt, H.; Hardy, W. T. (William Tyree)

    1932-01-01

    CONTAGIOUS ECTHYMA) IN.-: SHEEP AND GOATS A AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. 0. WALTON, President STATION STAFF? Administration : Veterinary Science : A. B. Conner. M. S., ulrec~or *M. Francis. D. V. M..... Dairy Husbandry -- - *Dean School of Veterinary Medicine. ?As of April 1, 1932. **In cooperation with U. S. Department of Agriculture. Soremouth (Contagious Ecthyma) in sheep and goats is an infectious disease and occurs especially in young animals...

  3. 21 CFR 1271.145 - Prevention of the introduction, transmission, or spread of communicable diseases.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...transmission, or spread of communicable diseases. 1271.145 Section 1271.145...transmission, or spread of communicable diseases. You must recover, process...transmission, or spread of communicable...

  4. Dealing with American Foulbrood American foulbrood (AFB) is a highly contagious bacterial disease of honey bee larvae. Diseased colonies usually

    E-print Network

    Ferrara, Katherine W.

    of honey bee larvae. Diseased colonies usually die. The unprotected, spore-contaminated nectar, honey inoculum to the next colonies. There is no method by which your bees can be prevented from robbing a dying or dead colony. So, if you are keeping bees in an area known to have a history of American foulbrood

  5. Modelling power-law spread of infectious diseases

    E-print Network

    Meyer, Sebastian

    2013-01-01

    Short-time human travel behaviour can be well described by a power law with respect to distance. We incorporate this information in space-time models for infectious disease surveillance data to better capture the dynamics of disease spread. Two previously established model classes are extended, which both decompose disease risk additively into endemic and epidemic components: a space-time point process model for individual point-referenced data, and a multivariate time series model for aggregated count data. In both frameworks, the power-law spread is embedded into the epidemic component and its decay parameter is estimated simultaneously with all other unknown parameters using (penalised) likelihood inference. The performance of the new approach is investigated by a re-analysis of individual cases of invasive meningococcal disease in Germany (2002-2008), and count data on influenza in 140 administrative districts of Southern Germany (2001-2008). In both applications, the power-law formulations substantially ...

  6. Retrograde spreading of hydrocortisone enema in inflammatory bowel disease

    SciTech Connect

    Jay, M.; Digenis, G.A.; Foster, T.S.; Antonow, D.R.

    1986-02-01

    A hydrocortisone suspension enema was radiolabeled with (/sup 99m/Tc)technetium sulfur colloid and administered to four normal subjects and eight patients with varying degrees of inflammatory bowel disease. The extent of enema spreading was monitored using external scintigraphy for a period of up to 4 hr after administration. Pretreatment of normal subjects with an evacuation enema resulted in spreading of the radiolabeled enema throughout the entire colon. In seven of the eight patients studied, the enema migrated a distance equal to or greater than the extent of disease involvement. An in vivo stability study with an indium-111-labeled enema, using the perturbed angular correlation technique, revealed that the enema retains its stability for up to 90 min after administration. These results indicate that the use of hydrocortisone enemas may not be restricted to distal bowel disease, but may also be effective in inflammatory bowel diseases involving proximal regions of the colon.

  7. Contagious yawning in chimpanzees.

    PubMed Central

    Anderson, James R; Myowa-Yamakoshi, Masako; Matsuzawa, Tetsuro

    2004-01-01

    Six adult female chimpanzees were shown video scenes of chimpanzees repeatedly yawning or of chimpanzees showing open-mouth facial expressions that were not yawns. Two out of the six females showed significantly higher frequencies of yawning in response to yawn videos; no chimpanzees showed the inverse. Three infant chimpanzees that accompanied their mothers did not yawn at all. These data are highly reminiscent of the contagious yawning effects reported for humans. Contagious yawning is thought to be based on the capacity for empathy. Contagious yawning in chimpanzees provides further evidence that these apes may possess advanced self-awareness and empathic abilities. PMID:15801606

  8. Contagious yawning in chimpanzees.

    PubMed

    Anderson, James R; Myowa-Yamakoshi, Masako; Matsuzawa, Tetsuro

    2004-12-01

    Six adult female chimpanzees were shown video scenes of chimpanzees repeatedly yawning or of chimpanzees showing open-mouth facial expressions that were not yawns. Two out of the six females showed significantly higher frequencies of yawning in response to yawn videos; no chimpanzees showed the inverse. Three infant chimpanzees that accompanied their mothers did not yawn at all. These data are highly reminiscent of the contagious yawning effects reported for humans. Contagious yawning is thought to be based on the capacity for empathy. Contagious yawning in chimpanzees provides further evidence that these apes may possess advanced self-awareness and empathic abilities. PMID:15801606

  9. The Committee Studying Contagious Disease Training for Public Safety Personnel. Report of the Committee on Training of the Criminal Justice Services Board to the Governor and the General Assembly of Virginia. House Document No. 15.

    ERIC Educational Resources Information Center

    Virginia State Dept. of Criminal Justice Services, Richmond.

    Through discussion and extensive research, the Committee Studying Contagious Disease Training attempted to address concerns regarding education and training of public safety personnel with regard to human immunodeficiency virus (HIV) and hepatitis B virus (HBV). The committee's findings were based on Occupational Safety and Health Administration…

  10. ? Several foreign animal diseases present a significant threat to the US cattle industry. The status of vaccines for high priority foreign animal diseases of cattle will be presented; including Foot and Mouth Disease, Rift Valley Fever, Rinderpest, Contagious Bovine Pleuropneumonia, and Heartwater

    Microsoft Academic Search

    James A. Roth

    KEY POINTS ? Of the high priority foreign animal diseases of cattle, vaccines are only available in the US for Foot and Mouth Disease. ? Research and development is urgently needed for improved vaccines for FMD, Rift Valley Fever, Contagious Bovine Pleuropneumonia, and Heartwater. OVERVIEW OF THE ISSUE The US has a vaccine bank for Foot and Mouth Disease and

  11. Spreading of diseases through comorbidity networks across life and gender

    NASA Astrophysics Data System (ADS)

    Chmiel, Anna; Klimek, Peter; Thurner, Stefan

    2014-11-01

    The state of health of patients is typically not characterized by a single disease alone but by multiple (comorbid) medical conditions. These comorbidities may depend strongly on age and gender. We propose a specific phenomenological comorbidity network of human diseases that is based on medical claims data of the entire population of Austria. The network is constructed from a two-layer multiplex network, where in one layer the links represent the conditional probability for a comorbidity, and in the other the links contain the respective statistical significance. We show that the network undergoes dramatic structural changes across the lifetime of patients. Disease networks for children consist of a single, strongly interconnected cluster. During adolescence and adulthood further disease clusters emerge that are related to specific classes of diseases, such as circulatory, mental, or genitourinary disorders. For people over 65 these clusters start to merge, and highly connected hubs dominate the network. These hubs are related to hypertension, chronic ischemic heart diseases, and chronic obstructive pulmonary diseases. We introduce a simple diffusion model to understand the spreading of diseases on the disease network at the population level. For the first time we are able to show that patients predominantly develop diseases that are in close network proximity to disorders that they already suffer. The model explains more than 85% of the variance of all disease incidents in the population. The presented methodology could be of importance for anticipating age-dependent disease profiles for entire populations, and for design and validation of prevention strategies.

  12. Spread of Infectious Diseases with a Latent Period

    E-print Network

    Mizuno, Kanako

    2015-01-01

    Infectious diseases spread through human networks. Susceptible-Infected-Removed (SIR) model is one of the epidemic models to describe infection dynamics on a complex network connecting individuals. In the metapopulation SIR model, each node represents a population (group) which has many individuals. In this paper, we propose a modified metapopulation SIR model in which a latent period is taken into account. We call it SIIR model. We divide the infection period into two stages: an infected stage, which is the same as the previous model, and a seriously ill stage, in which individuals are infected and cannot move to the other populations. The two infectious stages in our modified metapopulation SIR model produce a discontinuous final size distribution. Individuals in the infected stage spread the disease like individuals in the seriously ill stage and never recover directly, which makes an effective recovery rate smaller than the given recovery rate.

  13. The landscape genetics of infectious disease emergence and spread

    PubMed Central

    Biek, Roman; Real, Leslie A.

    2011-01-01

    The spread of parasites is inherently a spatial process often embedded in physically complex landscapes. It is therefore not surprising that infectious disease researchers are increasingly taking a landscape genetics perspective to elucidate mechanisms underlying basic ecological processes driving infectious disease dynamics and to understand the linkage between spatially-dependent population processes and the geographic distribution of genetic variation within both hosts and parasites. The increasing availability of genetic information on hosts and parasites when coupled to their ecological interactions can lead to insights for predicting patterns of disease emergence, spread, and control. Here, we review research progress in this area based on four different motivations for the application of landscape genetics approaches: (1) assessing the spatial organization of genetic variation in parasites as a function of environmental variability, (2) using host population genetic structure as a means to parameterize ecological dynamics that indirectly influence parasite populations, e.g. gene flow and movement pathways across heterogeneous landscapes and the concurrent transport of infectious agents, (3) elucidating the temporal and spatial scales of disease processes, and (4) reconstructing and understanding infectious disease invasion. Throughout this review, we emphasise that landscape genetic principles are relevant to infection dynamics across a range of scales from within host dynamics to global geographic patterns and that they can also be applied to unconventional “landscapes” such as heterogeneous contact networks underlying the spread of human and livestock diseases. We conclude by discussing some general considerations and problems for inferring epidemiological processes from genetic data and try to identify possible future directions and applications for this rapidly expanding field. PMID:20618897

  14. In vivo infection biology of contagious bovine pleuropneumonia 

    E-print Network

    Gull, Tamara Brownsey

    2009-05-15

    Contagious Bovine Pleuropneumonia (CBPP), caused by Mycoplasma mycoides mycoides small colony (MmmSC), is a devastating respiratory disease of cattle in Africa, Asia and the Middle East. Little investigation has been done on molecular disease...

  15. Forecasting the Airborne Spread of Foot-and-Mouth Disease and Newcastle Disease

    Microsoft Academic Search

    J. Gloster; L. P. Smith; W. H. G. Rees; J. D. Gillett; A. I. Donaldson; J. G. Loxam; R. F. Sellers; F. B. Smith

    1983-01-01

    The methods used in the United Kingdom to predict the airborne spread of foot-and-mouth disease and Newcastle disease are described in this paper. A brief description of both diseases and of the importance of their control is given first. Developments leading to the present methods of prediction are also described.

  16. Contagious yawning and the brain

    Microsoft Academic Search

    Steven M. Platek; Feroze B. Mohamed; Gordon G. Gallup Jr.

    2005-01-01

    Contagious yawning, the onset of a yawn triggered by seeing, hearing, reading, or thinking about another person yawn is a well-documented phenomenon. The mechanisms that drive contagious yawning are as yet unknown, but there is recent evidence of a link between contagious yawning and self-processing (S.M. Platek, S.R. Critton, T.E. Myers, G.G. Gallup Jr., Contagious yawning: the role of self-awareness

  17. Asymptomatic spread of huanglongbing and implications for disease control

    PubMed Central

    Lee, Jo Ann; Halbert, Susan E.; Dawson, William O.; Robertson, Cecile J.; Keesling, James E.; Singer, Burton H.

    2015-01-01

    Huanglongbing (HLB) is a bacterial infection of citrus trees transmitted by the Asian citrus psyllid Diaphorina citri. Mitigation of HLB has focused on spraying of insecticides to reduce the psyllid population and removal of trees when they first show symptoms of the disease. These interventions have been only marginally effective, because symptoms of HLB do not appear on leaves for months to years after initial infection. Limited knowledge about disease spread during the asymptomatic phase is exemplified by the heretofore unknown length of time from initial infection of newly developing cluster of young leaves, called flush, by adult psyllids until the flush become infectious. We present experimental evidence showing that young flush become infectious within 15 d after receiving an inoculum of Candidatus Liberibacter asiaticus (bacteria). Using this critical fact, we specify a microsimulation model of asymptomatic disease spread and intensity in a grove of citrus trees. We apply a range of psyllid introduction scenarios to show that entire groves can become infected with up to 12,000 psyllids per tree in less than 1 y, before most of the trees show any symptoms. We also show that intervention strategies that reduce the psyllid population by 75% during the flushing periods can delay infection of a full grove, and thereby reduce the amount of insecticide used throughout a year. This result implies that psyllid surveillance and control, using a variety of recently available technologies, should be used from the initial detection of invasion and throughout the asymptomatic period. PMID:26034273

  18. Asymptomatic spread of huanglongbing and implications for disease control.

    PubMed

    Lee, Jo Ann; Halbert, Susan E; Dawson, William O; Robertson, Cecile J; Keesling, James E; Singer, Burton H

    2015-06-16

    Huanglongbing (HLB) is a bacterial infection of citrus trees transmitted by the Asian citrus psyllid Diaphorina citri. Mitigation of HLB has focused on spraying of insecticides to reduce the psyllid population and removal of trees when they first show symptoms of the disease. These interventions have been only marginally effective, because symptoms of HLB do not appear on leaves for months to years after initial infection. Limited knowledge about disease spread during the asymptomatic phase is exemplified by the heretofore unknown length of time from initial infection of newly developing cluster of young leaves, called flush, by adult psyllids until the flush become infectious. We present experimental evidence showing that young flush become infectious within 15 d after receiving an inoculum of Candidatus Liberibacter asiaticus (bacteria). Using this critical fact, we specify a microsimulation model of asymptomatic disease spread and intensity in a grove of citrus trees. We apply a range of psyllid introduction scenarios to show that entire groves can become infected with up to 12,000 psyllids per tree in less than 1 y, before most of the trees show any symptoms. We also show that intervention strategies that reduce the psyllid population by 75% during the flushing periods can delay infection of a full grove, and thereby reduce the amount of insecticide used throughout a year. This result implies that psyllid surveillance and control, using a variety of recently available technologies, should be used from the initial detection of invasion and throughout the asymptomatic period. PMID:26034273

  19. Contagious Acute Gastrointestinal Infections

    Microsoft Academic Search

    Daniel M. Musher; Benjamin L. Musher

    2004-01-01

    n our ever-shrinking world, widespread media coverage of in- fections, ranging from the severe acute respiratory syndrome (also known as SARS) and influenza in Asia to acute gastroenteritis on cruise ships and outbreaks in day-care centers in the United States, has raised public interest in contagious diseas- es to new heights. Our purpose in this article is to examine contagion

  20. Spreading of periodic diseases and synchronization phenomena on networks

    NASA Astrophysics Data System (ADS)

    Ababou, M.; Vandewalle, N.; Moussa, N.; El Bouziani, M.; Ludewig, F.

    2013-05-01

    In this paper, we investigate numerically the Susceptible-Infected-Recovered-Susceptible (SIRS) epidemic model on an exponential network generated by a preferential attachment procedure. The discrete SIRS model considers two main parameters: the duration ?0 of the complete infection-recovery cycle and the duration ?I of infection. A permanent source of infection I0 has also been introduced in order to avoid the vanishing of the disease in the SIRS model. The fraction of infected agents is found to oscillate with a period T??0. Simulations reveal that the average fraction of infected agents depends on I0 and ?I/?0. A maximum of synchronization of infected agents, i.e. a maximum amplitude of periodic spreading oscillations, is found to occur when the ratio ?I/?0 is slightly smaller than 1/2. The model is in agreement with the general observation that an outbreak corresponds to high ?I/?0 values.

  1. The potential role of wildlife in the spread and control of foot and mouth disease in an extensive livestock management system 

    E-print Network

    Highfield, Linda

    2009-05-15

    Foot and mouth disease (FMD) is a highly contagious viral infection that affects all Artiodactyls (cloven-hoofed) species. The United States has been free of FMD since 1929, and the entire population of cloven-hoofed species ...

  2. Key Node Selection for Containing Infectious Disease Spread Using Particle Swarm Optimization

    E-print Network

    Wong, Limsoon

    Key Node Selection for Containing Infectious Disease Spread Using Particle Swarm Optimization Xiuju infectious diseases have grown into global health threats due to high human mobility. It is important to have intervention plans for containing the spread of such infectious diseases. Among various intervention strategies

  3. 9 CFR 147.27 - Procedures recommended to prevent the spread of disease by artificial insemination of turkeys.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...be inseminated. If evidence of active disease is noted after insemination is...

  4. GIS-Based Epidemiological Modeling of an Emerging Forest Disease: Spread of

    E-print Network

    Standiford, Richard B.

    247 GIS-Based Epidemiological Modeling of an Emerging Forest Disease: Spread of Sudden Oak Death applied in a GIS to real-world wildland landscapes. In this paper, we present and evaluate a GIS model was implemented (1990-2005) in a GIS to simulate disease spread across California at a spatial

  5. Genetic bases for Marek's disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek's disease (MD) is a highly contagious lymphoproliferative disease of chickens caused by MD virus (MDV). Therefore, the control of MD is of particular concern to the poultry industry. The poultry industry has been heavily relying on biosecurity and vaccination to control the spread and occurren...

  6. A Branching Model for the Spread of Infectious Animal Diseases in Varying

    E-print Network

    Meester, Ronald

    A Branching Model for the Spread of Infectious Animal Diseases in Varying Environments Pieter with a stochastic model, describing out- breaks of infectious diseases that have potentially great animal or hu- man of infectious diseases of animals (e.g. classical swine fever (CSF), foot and mouth disease (FMD) and Avian

  7. Contagious yawning and the brain.

    PubMed

    Platek, Steven M; Mohamed, Feroze B; Gallup, Gordon G

    2005-05-01

    Contagious yawning, the onset of a yawn triggered by seeing, hearing, reading, or thinking about another person yawn is a well-documented phenomenon. The mechanisms that drive contagious yawning are as yet unknown, but there is recent evidence of a link between contagious yawning and self-processing (S.M. Platek, S.R. Critton, T.E. Myers, G.G. Gallup Jr., Contagious yawning: the role of self-awareness and mental state attribution, Cogn. Brain Res. 17 (2003) 223-227.) that is negatively impacted by schizotypal personality traits. The neural substrates involved in contagious yawning, however, are unknown. Here, using fMRI, we show that viewing someone yawn evokes unique neural activity in the posterior cingulate and precuneus. Because of the role these areas play in self-processing (e.g., self-referential processing, theory of mind, autobiographical memory), our findings provide further support for the hypothesis that contagious yawning may be part of a neural network involved in empathy. PMID:15820652

  8. Modeling spatial spread of infectious diseases with a fixed latent period in a spatially continuous domain

    E-print Network

    Linder, Tamás

    Modeling spatial spread of infectious diseases with a fixed latent period in a spatially continuous, March 2009 Abstract In this paper, with the assumptions that an infectious disease in a population has the dynamics of infectious diseases in population level. Most continuous time models are in the form

  9. Modeling dynamic and network heterogeneities in the spread of sexually transmitted diseases

    Microsoft Academic Search

    Ken T. D. Eames; Matt J. Keeling

    2002-01-01

    A wide range of communicable human diseases can be considered as spreading through a network of possible transmission routes. The implied network structure is vital in determining disease dynamics, especially when the average number of connections per individual is small as is the case for many sexually transmitted diseases (STDs). Here we develop an intuitive mathematical framework to deal with

  10. Modeling social response to the spread of an infectious disease

    E-print Network

    Evans, Jane A. (Jane Amanda)

    2012-01-01

    With the globalization of culture and economic trade, it is increasingly important not only to detect outbreaks of infectious disease early, but also to anticipate the social response to the disease. In this thesis, we use ...

  11. Spreading of infectious diseases on complex networks with non-symmetric transmission probabilities

    E-print Network

    Britta Daudert; Bai-Lian Li

    2006-11-23

    We model the spread of a SIS infection on Small World and random networks using weighted graphs. The entry $w_{ij}$ in the weight matrix W holds information about the transmission probability along the edge joining node $v_i$ and node $v_j$. We use the analogy between the spread of a disease on a network and a random walk performed on this network to derive a master equation describing the dynamics of the process. We find conditions under which an epidemic does not break out and investigate numerically the effect of a non-symmetric weight distribution of the initially infected individual on the dynamics of the disease spread.

  12. DEVELOPMENT OF NOVEL STRATEGIES TO CONTROL FOOT-AND-MOUTH DISEASE: MARKER VACCINES AND ANTIVIRALS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease (FMD) is economically the most important viral-induced livestock disease worldwide. The disease is highly contagious and FMD virus (FMDV) replicates and spreads extremely rapidly. Outbreaks in previously FMD-free countries, including Taiwan, the United Kingdom, and Uruguay, ...

  13. Localization and Spreading of Diseases in Complex Networks

    NASA Astrophysics Data System (ADS)

    Goltsev, A. V.; Dorogovtsev, S. N.; Oliveira, J. G.; Mendes, J. F. F.

    2012-09-01

    Using the susceptible-infected-susceptible model on unweighted and weighted networks, we consider the disease localization phenomenon. In contrast to the well-recognized point of view that diseases infect a finite fraction of vertices right above the epidemic threshold, we show that diseases can be localized on a finite number of vertices, where hubs and edges with large weights are centers of localization. Our results follow from the analysis of standard models of networks and empirical data for real-world networks.

  14. Social networks and the spread of infectious diseases: The AIDS example

    Microsoft Academic Search

    Alden S. Klovdahl

    1985-01-01

    Conceptualizing a population as a set of individuals linked together to form a large social network provides a fruitful perspective for better understanding the spread of some infectious diseases. Data related to AIDS (the acquired immune deficiency syndrome) were used to illustrate the potential usefulness of a network approach in evaluating the infectious agent hypothesis when studying a disease or

  15. The dynamics of sexual contact networks: effects on disease spread and control

    E-print Network

    Cohen, Ted

    are shared between many sexually transmitted infections, the prevalence of these diseases across differentThe dynamics of sexual contact networks: effects on disease spread and control Katy Robinson1, Ted Sexually transmitted pathogens persist in populations despite the availability of biomedical interven tions

  16. Natural Human Mobility Patterns and Spatial Spread of Infectious Diseases

    NASA Astrophysics Data System (ADS)

    Belik, Vitaly; Geisel, Theo; Brockmann, Dirk

    2011-08-01

    We investigate a model for spatial epidemics explicitly taking into account bidirectional movements between base and destination locations on individual mobility networks. We provide a systematic analysis of generic dynamical features of the model on regular and complex metapopulation network topologies and show that significant dynamical differences exist to ordinary reaction-diffusion and effective force of infection models. On a lattice we calculate an expression for the velocity of the propagating epidemic front and find that, in contrast to the diffusive systems, our model predicts a saturation of the velocity with an increasing traveling rate. Furthermore, we show that a fully stochastic system exhibits a novel threshold for the attack ratio of an outbreak that is absent in diffusion and force of infection models. These insights not only capture natural features of human mobility relevant for the geographical epidemic spread, they may serve as a starting point for modeling important dynamical processes in human and animal epidemiology, population ecology, biology, and evolution.

  17. Contagious Yawning in Autistic and Typical Development

    ERIC Educational Resources Information Center

    Helt, Molly S.; Eigsti, Inge-Marie; Snyder, Peter J.; Fein, Deborah A.

    2010-01-01

    The authors tested susceptibility to contagious yawning in 120 children, 1-6 years, to identify the time course of its emergence during development. Results indicated a substantial increase in the frequency of contagious yawning at 4 years. In a second study, the authors examined contagious yawning in 28 children with autism spectrum disorders…

  18. Evaluating the links between climate, disease spread, and amphibian declines.

    PubMed

    Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J

    2008-11-11

    Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines, more convincing evidence is needed of a causal link. PMID:18987318

  19. Evaluating the links between climate, disease spread, and amphibian declines

    PubMed Central

    Rohr, Jason R.; Raffel, Thomas R.; Romansic, John M.; McCallum, Hamish; Hudson, Peter J.

    2008-01-01

    Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines, more convincing evidence is needed of a causal link. PMID:18987318

  20. Endemic models for the spread of infectious diseases with arbitrarily ...

    E-print Network

    SIAM (#1) 1035 1999 Jan 20 12:53:14

    2000-09-19

    The main body of the paper is devoted to analyzing the fundamental properties ...... the fact that the solutions of the system in section 2.2 can be recast as solutions of .... R. M. Anderson and R. M. May (1991), Infectious Diseases of Humans, Oxford ... 101–106. O. Diekmann and S. A. Van Gils (1989), Invariant manifolds for ...

  1. Describing the geographic spread of dengue disease by traveling waves

    Microsoft Academic Search

    Norberto Aníbal Maidana; Hyun Mo Yang

    2008-01-01

    Dengue is a human disease transmitted by the mosquito Aedes aegypti. For this reason geographical regions infested by this mosquito species are under the risk of dengue outbreaks. In this work, we propose a mathematical model to study the spatial dissemination of dengue using a system of partial differential reaction–diffusion equations. With respect to the human and mosquito populations, we

  2. Endemic models for the spread of infectious diseases with arbitrarily ...

    E-print Network

    SIAM (#1) 1035 1999 Jan 20 12:53:14

    2000-10-03

    Key words. many infection stages, arbitrary stage length distributions, stage ... While this shows that most epidemic models are not realistic in modeling the .... found very good agreement for many childhood diseases, but somewhat less ..... thin in so far as they do not contain open sets, and actually the local unstable man-.

  3. Using the Gravity Model to Estimate the Spatial Spread of Vector-Borne Diseases

    PubMed Central

    Barrios, José Miguel; Verstraeten, Willem W.; Maes, Piet; Aerts, Jean-Marie; Farifteh, Jamshid; Coppin, Pol

    2012-01-01

    The gravity models are commonly used spatial interaction models. They have been widely applied in a large set of domains dealing with interactions amongst spatial entities. The spread of vector-borne diseases is also related to the intensity of interaction between spatial entities, namely, the physical habitat of pathogens’ vectors and/or hosts, and urban areas, thus humans. This study implements the concept behind gravity models in the spatial spread of two vector-borne diseases, nephropathia epidemica and Lyme borreliosis, based on current knowledge on the transmission mechanism of these diseases. Two sources of information on vegetated systems were tested: the CORINE land cover map and MODIS NDVI. The size of vegetated areas near urban centers and a local indicator of occupation-related exposure were found significant predictors of disease risk. Both the land cover map and the space-borne dataset were suited yet not equivalent input sources to locate and measure vegetated areas of importance for disease spread. The overall results point at the compatibility of the gravity model concept and the spatial spread of vector-borne diseases. PMID:23202882

  4. Describing the geographic spread of dengue disease by traveling waves.

    PubMed

    Maidana, Norberto Aníbal; Yang, Hyun Mo

    2008-09-01

    Dengue is a human disease transmitted by the mosquito Aedes aegypti. For this reason geographical regions infested by this mosquito species are under the risk of dengue outbreaks. In this work, we propose a mathematical model to study the spatial dissemination of dengue using a system of partial differential reaction-diffusion equations. With respect to the human and mosquito populations, we take into account their respective subclasses of infected and uninfected individuals. The dynamics of the mosquito population considers only two subpopulations: the winged form (mature female mosquitoes), and an aquatic population (comprising eggs, larvae and pupae). We disregard the long-distance movement by transportation facilities, for which reason the diffusion is considered restricted only to the winged form. The human population is considered homogeneously distributed in space, in order to describe localized dengue dissemination during a short period of epidemics. The cross-infection is modeled by the law of mass action. A threshold value as a function of the model's parameters is obtained, which determines the rate of dengue dissemination and the risk of dengue outbreaks. Assuming that an area was previously colonized by the mosquitoes, the rate of disease dissemination is determined as a function of the model's parameters. This rate of dissemination of dengue disease is determined by applying the traveling wave solutions to the corresponding system of partial differential equations. PMID:18590749

  5. Presence and Seeding Activity of Pathological Prion Protein (PrPTSE) in Skeletal Muscles of White-Tailed Deer Infected with Chronic Wasting Disease

    Microsoft Academic Search

    Martin L. Daus; Johanna Breyer; Katja Wagenfuehr; Wiebke M. Wemheuer; Achim Thomzig; Walter J. Schulz-Schaeffer; Michael Beekes

    2011-01-01

    Chronic wasting disease (CWD) is a contagious, rapidly spreading transmissible spongiform encephalopathy (TSE), or prion disease, occurring in cervids such as white tailed-deer (WTD), mule deer or elk in North America. Despite efficient horizontal transmission of CWD among cervids natural transmission of the disease to other species has not yet been observed. Here, we report for the first time a

  6. Generalized Markov Models of Infectious Disease Spread: A Novel Framework for Developing Dynamic Health Policies

    PubMed Central

    Yaesoubi, Reza; Cohen, Ted

    2011-01-01

    We propose a class of mathematical models for the transmission of infectious diseases in large populations. This class of models, which generalizes the existing discrete-time Markov chain models of infectious diseases, is compatible with efficient dynamic optimization techniques to assist real-time selection and modification of public health interventions in response to evolving epidemiological situations and changing availability of information and medical resources. While retaining the strength of existing classes of mathematical models in their ability to represent the within-host natural history of disease and between-host transmission dynamics, the proposed models possess two advantages over previous models: (1) these models can be used to generate optimal dynamic health policies for controlling spreads of infectious diseases, and (2) these models are able to approximate the spread of the disease in relatively large populations with a limited state space size and computation time. PMID:21966083

  7. Chronic Wasting Disease

    USGS Publications Warehouse

    Richards, Bryan

    2007-01-01

    Chronic wasting disease (CWD) is an always-fatal, neurological illness occurring in North American cervids (members of the deer family), including white-tailed deer, mule deer, elk and moose. Since its discovery in 1967, CWD has spread geographically and increased in prevalence locally. CWD is contagious; it can be transmitted freely within and among free-ranging populations. It is likely that diseased animals can transmit CWD to healthy animals long before they become clinically ill. Managing CWD in free-ranging populations is extremely difficult, therefore preventative measures designed to reduce the chance for disease spread are critically important.

  8. Disease Risk in a Dynamic Environment: The Spread of Tick-Borne Pathogens in Minnesota, USA

    PubMed Central

    Robinson, Stacie J.; Neitzel, David F.; Moen, Ronald A.; Craft, Meggan E.; Hamilton, Karin E.; Johnson, Lucinda B.; Mulla, David J.; Munderloh, Ulrike G.; Redig, Patrick T.; Smith, Kirk E.; Turner, Clarence L.; Umber, Jamie K.; Pelican, Katharine M.

    2015-01-01

    As humans and climate change alter the landscape, novel disease risk scenarios emerge. Understanding the complexities of pathogen emergence and subsequent spread as shaped by landscape heterogeneity is crucial to understanding disease emergence, pinpointing high-risk areas, and mitigating emerging disease threats in a dynamic environment. Tick-borne diseases present an important public health concern and incidence of many of these diseases are increasing in the United States. The complex epidemiology of tick-borne diseases includes strong ties with environmental factors that influence host availability, vector abundance, and pathogen transmission. Here, we used 16 years of case data from the Minnesota Department of Health to report spatial and temporal trends in Lyme disease (LD), human anaplasmosis, and babesiosis. We then used a spatial regression framework to evaluate the impact of landscape and climate factors on the spread of LD. Finally, we use the fitted model, and landscape and climate datasets projected under varying climate change scenarios, to predict future changes in tick-borne pathogen risk. Both forested habitat and temperature were important drivers of LD spread in Minnesota. Dramatic changes in future temperature regimes and forest communities predict rising risk of tick-borne disease. PMID:25281302

  9. A Hybrid Model for Disease Spread and an Application to the SARS Pandemic

    E-print Network

    Yoneyama, Teruhiko; Krishnamoorthy, Mukkai

    2010-01-01

    Pandemics can cause immense disruption and damage to communities and societies. Thus far, modeling of pandemics has focused on either large-scale difference equation models like the SIR and the SEIR models, or detailed micro-level simulations, which are harder to apply at a global scale. This paper introduces a hybrid model for pandemics considering both global and local spread of infections. We hypothesize that the spread of an infectious disease between regions is significantly influenced by global traffic patterns and the spread within a region is influenced by local conditions. Thus we model the spread of pandemics considering the connections between regions for the global spread of infection and population density based on the SEIR model for the local spread of infection. We validate our hybrid model by carrying out a simulation study for the spread of SARS pandemic of 2002-2003 using available data on population, population density, and traffic networks between different regions. While it is well-known ...

  10. Studies on the 1967-8 foot-and-mouth disease epidemic. The relation of weather to the spread of disease.

    PubMed

    Hugh-Jones, M E; Wright, P B

    1970-06-01

    An analysis of the 1967-8 foot-and-mouth disease epidemic with reference to the initial spread, the origin of outbreaks more than 60 km. from the main epidemic area, the series of outbreaks near Worcester, a specific case history and the daily rate of spread of the epidemic, strongly suggests that the weather played a major part in the spread of disease. The two main factors involved in this type of spread are wind and precipitation. It is noted that after the epidemic had been checked, following anticyclonic weather, the association between the weather and the spread of disease was less apparent. PMID:5270205

  11. Analysis of sexually transmitted disease spreading in heterosexual and homosexual populations.

    PubMed

    Zhang, Juping; Jin, Zhen; Chen, Yuming

    2013-04-01

    Sexually transmitted diseases can pose major health problems so scientists and health agencies are very concerned about the spread of these diseases. Sexually transmitted diseases spread through a network of contacts created by the formation of sexual partnerships. In the paper, the spreading of sexually transmitted diseases on bipartite scale-free graphs, representing heterosexual and homosexual contact networks, is considered. We propose an SIS model on sexual contact networks. We analytically derive the expression for the epidemic threshold and its dependence with the ratio of female and male in finite populations. It is shown that if the basic reproduction number R0 is less than 1 then the disease-free equilibrium is globally asymptotically stable; if R0>1 then the disease-free equilibrium is unstable and there is a unique endemic equilibrium, which asymptotically attracts all nontrivial solutions. These theoretical results are supported by numerical simulations. We also carry out some sensitivity analysis of the basic reproduction number R0 in terms of various model parameters. PMID:23403371

  12. Porcine type I interferon rapidly protects swine against challenge with multiple serotypes of foot-and-mouth disease virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals that rapidly replicates and spreads within infected animals and into the environment. Vaccines require approximately 7 days to induce protection, but prior to this time vaccinated animals are still suscep...

  13. Developmental and comparative perspectives of contagious yawning.

    PubMed

    Senju, Atsushi

    2010-01-01

    Contagious yawning (i.e. yawning triggered by perceiving others' yawning) is a well-documented phenomenon, but the mechanism underlying it is still unclear. In this chapter, I review the current evidence about: (1) developmental studies with typically and atypically developing populations, and (2) comparative studies in non-human animals. Developmental studies have revealed that contagious yawning is disturbed in individuals with autism spectrum disorders, suggesting that contagious yawning may share a developmental basis with the capacity for theory of mind. Comparative studies have suggested that contagious yawning can be observed in non-primate species, such as domestic dogs. As dogs are known to have exceptional skills in communicating with humans, it has also been suggested that contagious yawning may be related to the capacity for social communication. These results from developmental and comparative studies are consistent with the claim that the mechanism underlying contagious yawning relates to the capacity for empathy. PMID:20357469

  14. Disease properties, geography, and mitigation strategies in a simulation spread of rinderpest across the United States

    PubMed Central

    2011-01-01

    For the past decade, the Food and Agriculture Organization of the United Nations has been working toward eradicating rinderpest through vaccination and intense surveillance by 2012. Because of the potential severity of a rinderpest epidemic, it is prudent to prepare for an unexpected outbreak in animal populations. There is no immunity to the disease among the livestock or wildlife in the United States (US). If rinderpest were to emerge in the US, the loss in livestock could be devastating. We predict the potential spread of rinderpest using a two-stage model for the spread of a multi-host infectious disease among agricultural animals in the US. The model incorporates large-scale interactions among US counties and the small-scale dynamics of disease spread within a county. The model epidemic was seeded in 16 locations and there was a strong dependence of the overall epidemic size on the starting location. The epidemics were classified according to overall size into small epidemics of 100 to 300 animals (failed epidemics), epidemics infecting 3 000 to 30 000 animals (medium epidemics), and the large epidemics infecting around one million beef cattle. The size of the rinderpest epidemics were directly related to the origin of the disease and whether or not the disease moved into certain key counties in high-livestock-density areas of the US. The epidemic size also depended upon response time and effectiveness of movement controls. PMID:21435236

  15. A Manual of Poultry Diseases

    E-print Network

    Bell, R. R.; Flowers, A. I.; Grumbles, L. C.; Meinecke, C. F.; Patterson, C. M.; Wormell, B. C.; Hall, C. F.

    1965-01-01

    diseases, such as coccidiosis, mechanical damage to tissues is an important factor. All contagious diseases are infectious, but all infectious diseases are not contagious. A contagious disease is one that is transmitted readily from one individual... or flock to another. An infectious dis- ease is one produced by living organisms. Most infectious diseases of poultry are contagious; how- ever, a few, such as aspergillosis are not. The ability of an organism to cause disease in the particular host...

  16. Airborne spread of foot-and-mouth disease--model intercomparison.

    PubMed

    Gloster, John; Jones, Andrew; Redington, Alison; Burgin, Laura; Sřrensen, Jens H; Turner, Richard; Dillon, Michael; Hullinger, Pam; Simpson, Matthew; Astrup, Poul; Garner, Graeme; Stewart, Paul; D'Amours, Réal; Sellers, Robert; Paton, David

    2010-03-01

    Foot-and-mouth disease virus (FMDV) spreads by direct contact between animals, by animal products (milk, meat and semen), by mechanical transfer on people or fomites and by the airborne route, with the relative importance of each mechanism depending on the particular outbreak characteristics. Atmospheric dispersion models have been developed to assess airborne spread of FMDV in a number of countries, including the UK, Denmark, Australia, New Zealand, USA and Canada. These models were compared at a Workshop hosted by the Institute for Animal Health/Met Office in 2008. Each modeller was provided with data relating to the 1967 outbreak of FMD in Hampshire, UK, and asked to predict the spread of FMDV by the airborne route. A number of key issues emerged from the Workshop and subsequent modelling work: (1) in general all models predicted similar directions for livestock at risk, with much of the remaining differences strongly related to differences in the meteorological data used; (2) determination of an accurate sequence of events on the infected premises is highly important, especially if the meteorological conditions vary substantially during the virus emission period; (3) differences in assumptions made about virus release, environmental fate and susceptibility to airborne infection can substantially modify the size and location of the downwind risk area. All of the atmospheric dispersion models compared at the Workshop can be used to assess windborne spread of FMDV and provide scientific advice to those responsible for making control and eradication decisions in the event of an outbreak of disease. PMID:19138867

  17. Disinfection of foot-and-mouth disease and African swine fever viruses with citric acid and sodium hypochlorite on birch wood carriers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transboundary animal disease viruses such as foot-and-mouth disease virus (FMDV) and African swine fever virus (ASFV) are highly contagious and cause severe morbidity and mortality in livestock. Proper disinfection during an outbreak can help prevent virus spread and will shorten the time for contam...

  18. A Manual of Poultry Diseases

    E-print Network

    Hall, C. F.; Bell, R. R.; Clifford, R. L., Jr.; Glass, S. E.; Grimes, J. E.; Grumbles, L. C.; Keahey, E. E.; Wormell, B. C.

    1971-01-01

    contagious diseases are infectious, but all infectious diseases are not contagious. A contagious disease is one that is transmitted readily from one individual or flock to another. An infectious dis- ease is one produced by living organisms. Most... infectious diseases of poultry are contagious; how- ever, a few such as aspergillosis are not. The ability of an organism to cause disease in the particular host is known as its virulence or pathogenicity. Many microorganisms that are un- able to cause...

  19. Contagious yawning in autistic and typical development.

    PubMed

    Helt, Molly S; Eigsti, Inge-Marie; Snyder, Peter J; Fein, Deborah A

    2010-01-01

    The authors tested susceptibility to contagious yawning in 120 children, 1-6 years, to identify the time course of its emergence during development. Results indicated a substantial increase in the frequency of contagious yawning at 4 years. In a second study, the authors examined contagious yawning in 28 children with autism spectrum disorders (ASD), 6-15 years. Children with ASD showed diminished susceptibility to contagious yawning compared with 2 control groups matched for mental and chronological age, respectively. In addition, children diagnosed with Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS) a milder variant of autism, were more susceptible to contagious yawning than were children diagnosed with full Autistic Disorder. The authors explore the implications of these findings for theories about the development of mimicry and emotional contagion. PMID:20840244

  20. Modelling the spread of sexually transmitted diseases on scale-free networks

    NASA Astrophysics Data System (ADS)

    Liu, Mao-Xing; Ruan, Jiong

    2009-06-01

    In this paper a new model for the spread of sexually transmitted diseases (STDs) is presented. The dynamic behaviors of the model on a heterogenous scale-free (SF) network are considered, where the absence of a threshold on the SF network is demonstrated, and the stability of the disease-free equilibrium is obtained. Three immunization strategies, uniform immunization, proportional immunization and targeted immunization, are applied in this model. Analytical and simulated results are given to show that the proportional immunization strategy in the model is effective on SF networks.

  1. Host mating system and the spread of a disease-resistant allele in a population

    USGS Publications Warehouse

    DeAngelis, D.L.; Koslow, J.M.; Jiang, J.; Ruan, S.

    2008-01-01

    The model presented here modifies a susceptible-infected (SI) host-pathogen model to determine the influence of mating system on the outcome of a host-pathogen interaction. Both deterministic and stochastic (individual-based) versions of the model were used. This model considers the potential consequences of varying mating systems on the rate of spread of both the pathogen and resistance alleles within the population. We assumed that a single allele for disease resistance was sufficient to confer complete resistance in an individual, and that both homozygote and heterozygote resistant individuals had the same mean birth and death rates. When disease invaded a population with only an initial small fraction of resistant genes, inbreeding (selfing) tended to increase the probability that the disease would soon be eliminated from a small population rather than become endemic, while outcrossing greatly increased the probability that the population would become extinct due to the disease.

  2. Global warming and the potential spread of vector-borne diseases

    SciTech Connect

    Patz, J. [Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (United States). Dept. of Microbiology and Immunology

    1996-12-31

    Climatic factors influence many vector-borne infectious diseases, in addition to demographic, biological, and ecological determinants. The United Nation`s Intergovernmental Panel on Climate Change (IPCC) estimates an unprecedented global rise of 2.0 C by the year 2100. Of major concern is that these changes can affect the spread of many serious infectious diseases, including malaria and dengue fever. Global warming would directly affect disease transmission by shifting the mosquito`s geographic range, increasing reproductive and biting rates, and shortening pathogen incubation period. Human migration and damage to health infrastructures from the projected increase in climate variability and sea level rise could indirectly contribute to disease transmission. A review of this literature, as well as preliminary data from ongoing studies will be presented.

  3. Treatment of contagious caprine pleuropneumonia.

    PubMed

    Rurangirwa, F R; Masiga, W N; Muriu, D N; Muthomi, E; Mulira, G; Kagumba, M; Nandokha, E

    1981-08-01

    A combination of dihydrostreptomycin sulphate (250 mg/ml) and penicillin G procaine (200,000 iu/ml) was used to treat contagious caprine pleuropneumonia caused by F38 strain of mycoplasma. A single dose of either 20, 30, 40 or 50 mg/kg body weight of the dihydrostreptomycin sulphate led to the recovery of the treated goats. The recovered goats did not transmit CCPP to susceptible goats housed with them for 2 months. The goats which recovered were found to be solidly immune to an in-contact challenge in which all the control goats died of CCPP. The treated and recovered goats were found not to be carriers of the organism. PMID:6170140

  4. Spreading of Alzheimer’s disease inflammatory signaling through soluble micro-RNA

    PubMed Central

    Lukiw, Walter J.; Alexandrov, Peter N.; Zhao, Yuhai; Hill, James M.; Bhattacharjee, Surjyadipta

    2015-01-01

    Alzheimer’s disease is a progressive, neurodegenerative disorder that develops within the limbic system, spreading radially into anatomically linked brain association areas as the disease progresses. Analysis of temporal-lobe association of neocortex-derived extracellular fluid and cerebrospinal fluid from Alzheimer’s disease patients shows an abundant presence of micro-RNA (miRNA), including the proinflammatory miRNA-146a and miRNA-155. Using a novel and highly sensitive LED-Northern dot-blot focusing technique, we detected the secretion of potentially pathogenic amounts of miRNA-146a and miRNA-155 from stressed human primary neural cells. A conditioned medium containing miRNA-146a and miRNA-155 was found to induce Alzheimer-type gene expression changes in control brain cells. These included downregulation in the expression of an important repressor of the innate immune response, complement factor H (CFH). These effects were neutralized using anti-miRNA strategies. Anti-miRNA-based therapeutics may provide a novel and efficacious treatment to stem the miRNA-mediated spreading of inflammatory signaling involved in Alzheimer’s disease. PMID:22660168

  5. Phlebotomine sandflies and the spreading of leishmaniases and other diseases of public health concern.

    PubMed

    Maroli, M; Feliciangeli, M D; Bichaud, L; Charrel, R N; Gradoni, L

    2013-06-01

    Phlebotomine sandflies transmit pathogens that affect humans and animals worldwide. We review the roles of phlebotomines in the spreading of leishmaniases, sandfly fever, summer meningitis, vesicular stomatitis, Chandipura virus encephalitis and Carrión's disease. Among over 800 species of sandfly recorded, 98 are proven or suspected vectors of human leishmaniases; these include 42 Phlebotomus species in the Old World and 56 Lutzomyia species in the New World (all: Diptera: Psychodidae). Based on incrimination criteria, we provide an updated list of proven or suspected vector species by endemic country where data are available. Increases in sandfly diffusion and density resulting from increases in breeding sites and blood sources, and the interruption of vector control activities contribute to the spreading of leishmaniasis in the settings of human migration, deforestation, urbanization and conflict. In addition, climatic changes can be expected to affect the density and dispersion of sandflies. Phlebovirus infections and diseases are present in large areas of the Old World, especially in the Mediterranean subregion, in which virus diversity has proven to be higher than initially suspected. Vesiculovirus diseases are important to livestock and humans in the southeastern U.S.A. and Latin America, and represent emerging human threats in parts of India. Carrión's disease, formerly restricted to regions of elevated altitude in Peru, Ecuador and Colombia, has shown recent expansion to non-endemic areas of the Amazon basin. PMID:22924419

  6. Parasite consumption and host interference can inhibit disease spread in dense populations.

    PubMed

    Civitello, David J; Pearsall, Susan; Duffy, Meghan A; Hall, Spencer R

    2013-05-01

    Disease dynamics hinge on parasite transmission among hosts. However, canonical models for transmission often fit data poorly, limiting predictive ability. One solution involves building mechanistic yet general links between host behaviour and disease spread. To illustrate, we focus on the exposure component of transmission for hosts that consume their parasites, combining experiments, models and field data. Models of transmission that incorporate parasite consumption and foraging interference among hosts vastly outperformed alternatives when fit to experimental data using a zooplankton host (Daphnia dentifera) that consumes spores of a fungus (Metschnikowia bicuspidata). Once plugged into a fully dynamic model, both mechanisms inhibited epidemics overall. Foraging interference further depressed parasite invasion and prevalence at high host density, creating unimodal (hump-shaped) relationships between host density and these indices. These novel results qualitatively matched a unimodal density-prevalence relationship in natural epidemics. Ultimately, a mechanistic approach to transmission can reveal new insights into disease outbreaks. PMID:23452184

  7. Enhanced Antiviral Activity Against Foot-and-Mouth Disease Virus by the Combination of Bovine Type 1 and 2 Interferons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease virus (FMDV) is the most contagious pathogen of cloven-hoofed animals including swine and bovines. The emergency control of outbreaks is dependent on rapid protection and prevention of spread of the infection. Human adenovirus type 5 expressing porcine interferon alpha (Ad5-pI...

  8. Enhanced antiviral activity against foot-and-mouth disease virus by the combination of bovine type 1 and 2 interferons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease virus (FMDV) is the most contagious pathogen of cloven-hoofed animals including swine and bovines. In emergency control of outbreaks, it is fundamental to develop rapid protection to prevent spread of the infection. It has been shown that inoculation of 10^10 pfu of human aden...

  9. Risks of spreading foot and mouth disease through milk and dairy products.

    PubMed

    Donaldson, A I

    1997-04-01

    A review of epidemics of foot and mouth disease (FMD) has highlighted the important role which raw (untreated) milk can play in the spread of the disease in a country which is normally free of FMD and whose cattle are not routinely vaccinated. The greatest hazard is likely to be in the early stages of an outbreak, before disease control measures have been implemented. The spread of FMD through milk can be prevented by the effective application of control measures combined with 'codes of practice' for the treatment of potentially infected milk. The author considers the probable mechanisms of transmission of FMD by milk and dairy products. These mechanisms are based on the quantities of virus excreted in milk, the survival of the virus under various management and manufacturing conditions and the minimum doses required to initiate infection in susceptible animals by different routes. The key points for consideration when making a risk assessment of the importation of milk and dairy products are also discussed. PMID:9329112

  10. Catch the wave: prairie dogs assess neighbours’ awareness using contagious displays

    PubMed Central

    Hare, James F.; Campbell, Kevin L.; Senkiw, Robert W.

    2014-01-01

    The jump–yip display of black-tailed prairie dogs (Cynomys ludovicianus) is contagious, spreading through a prairie dog town as ‘the wave’ through a stadium. Because contagious communication in primates serves to assess conspecific social awareness, we investigated whether instigators of jump–yip bouts adjusted their behaviour relative to the response of conspecifics recruited to display bouts. Increased responsiveness of neighbouring town members resulted in bout initiators devoting a significantly greater proportion of time to active foraging. Contagious jump–yips thus function to assess neighbours’ alertness, soliciting social information to assess effective conspecific group size in real time and reveal active probing of conspecific awareness consistent with theory of mind in these group-living rodents. PMID:24403324

  11. Catch the wave: prairie dogs assess neighbours' awareness using contagious displays.

    PubMed

    Hare, James F; Campbell, Kevin L; Senkiw, Robert W

    2014-02-22

    The jump-yip display of black-tailed prairie dogs (Cynomys ludovicianus) is contagious, spreading through a prairie dog town as 'the wave' through a stadium. Because contagious communication in primates serves to assess conspecific social awareness, we investigated whether instigators of jump-yip bouts adjusted their behaviour relative to the response of conspecifics recruited to display bouts. Increased responsiveness of neighbouring town members resulted in bout initiators devoting a significantly greater proportion of time to active foraging. Contagious jump-yips thus function to assess neighbours' alertness, soliciting social information to assess effective conspecific group size in real time and reveal active probing of conspecific awareness consistent with theory of mind in these group-living rodents. PMID:24403324

  12. Molecular drivers and cortical spread of lateral entorhinal cortex dysfunction in preclinical Alzheimer's disease.

    PubMed

    Khan, Usman A; Liu, Li; Provenzano, Frank A; Berman, Diego E; Profaci, Caterina P; Sloan, Richard; Mayeux, Richard; Duff, Karen E; Small, Scott A

    2014-02-01

    The entorhinal cortex has been implicated in the early stages of Alzheimer's disease, which is characterized by changes in the tau protein and in the cleaved fragments of the amyloid precursor protein (APP). We used a high-resolution functional magnetic resonance imaging (fMRI) variant that can map metabolic defects in patients and mouse models to address basic questions about entorhinal cortex pathophysiology. The entorhinal cortex is divided into functionally distinct regions, the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC), and we exploited the high-resolution capabilities of the fMRI variant to ask whether either of them was affected in patients with preclinical Alzheimer's disease. Next, we imaged three mouse models of disease to clarify how tau and APP relate to entorhinal cortex dysfunction and to determine whether the entorhinal cortex can act as a source of dysfunction observed in other cortical areas. We found that the LEC was affected in preclinical disease, that LEC dysfunction could spread to the parietal cortex during preclinical disease and that APP expression potentiated tau toxicity in driving LEC dysfunction, thereby helping to explain regional vulnerability in the disease. PMID:24362760

  13. Developmental and Comparative Perspectives of Contagious Yawning

    Microsoft Academic Search

    Atsushi Senju

    2010-01-01

    Contagious yawning (i.e. yawning triggered by perceiving others’ yawning) is a well-documented phenomenon, but the mechanism underlying it is still unclear. In this chapter, I review the current evidence about: (1) developmental studies with typically and atypically developing populations, and (2) comparative studies in non-human animals. Developmental studies have revealed that contagious yawning is disturbed in individuals with autism spectrum

  14. Do dogs ( Canis familiaris ) show contagious yawning?

    Microsoft Academic Search

    Aimee L. Harr; Valerie R. Gilbert; Kimberley A. Phillips

    2009-01-01

    We report an experimental investigation into whether domesticated dogs display contagious yawning. Fifteen dogs were shown\\u000a video clips of (1) humans and (2) dogs displaying yawns and open-mouth expressions (not yawns) to investigate whether dogs\\u000a showed contagious yawning to either of these social stimuli. Only one dog performed significantly more yawns during or shortly\\u000a after viewing yawning videos than to

  15. A Lagrangian particle model to predict the airborne spread of foot-and-mouth disease virus

    NASA Astrophysics Data System (ADS)

    Mayer, D.; Reiczigel, J.; Rubel, F.

    Airborne spread of bioaerosols in the boundary layer over a complex terrain is simulated using a Lagrangian particle model, and applied to modelling the airborne spread of foot-and-mouth disease (FMD) virus. Two case studies are made with study domains located in a hilly region in the northwest of the Styrian capital Graz, the second largest town in Austria. Mountainous terrain as well as inhomogeneous and time varying meteorological conditions prevent from application of so far used Gaussian dispersion models, while the proposed model can handle these realistically. In the model, trajectories of several thousands of particles are computed and the distribution of virus concentration near the ground is calculated. This allows to assess risk of infection areas with respect to animal species of interest, such as cattle, swine or sheep. Meteorological input data like wind field and other variables necessary to compute turbulence were taken from the new pre-operational version of the non-hydrostatic numerical weather prediction model LMK ( Lokal-Modell-Kürzestfrist) running at the German weather service DWD ( Deutscher Wetterdienst). The LMK model provides meteorological parameters with a spatial resolution of about 2.8 km. To account for the spatial resolution of 400 m used by the Lagrangian particle model, the initial wind field is interpolated upon the finer grid by a mass consistent interpolation method. Case studies depict a significant influence of local wind systems on the spread of virus. Higher virus concentrations at the upwind side of the hills and marginal concentrations in the lee are well observable, as well as canalization effects by valleys. The study demonstrates that the Lagrangian particle model is an appropriate tool for risk assessment of airborne spread of virus by taking into account the realistic orographic and meteorological conditions.

  16. Transmission of chronic wasting disease in Wisconsin white-tailed deer: implications for disease spread and management.

    PubMed

    Jennelle, Christopher S; Henaux, Viviane; Wasserberg, Gideon; Thiagarajan, Bala; Rolley, Robert E; Samuel, Michael D

    2014-01-01

    Few studies have evaluated the rate of infection or mode of transmission for wildlife diseases, and the implications of alternative management strategies. We used hunter harvest data from 2002 to 2013 to investigate chronic wasting disease (CWD) infection rate and transmission modes, and address how alternative management approaches affect disease dynamics in a Wisconsin white-tailed deer population. Uncertainty regarding demographic impacts of CWD on cervid populations, human and domestic animal health concerns, and potential economic consequences underscore the need for strategies to control CWD distribution and prevalence. Using maximum-likelihood methods to evaluate alternative multi-state deterministic models of CWD transmission, harvest data strongly supports a frequency-dependent transmission structure with sex-specific infection rates that are two times higher in males than females. As transmissible spongiform encephalopathies are an important and difficult-to-study class of diseases with major economic and ecological implications, our work supports the hypothesis of frequency-dependent transmission in wild deer at a broad spatial scale and indicates that effective harvest management can be implemented to control CWD prevalence. Specifically, we show that harvest focused on the greater-affected sex (males) can result in stable population dynamics and control of CWD within the next 50 years, given the constraints of the model. We also provide a quantitative estimate of geographic disease spread in southern Wisconsin, validating qualitative assessments that CWD spreads relatively slowly. Given increased discovery and distribution of CWD throughout North America, insights from our study are valuable to management agencies and to the general public concerned about the impacts of CWD on white-tailed deer populations. PMID:24658535

  17. Diagnosis and control of contagious caprine pleuropneumonia.

    PubMed

    Thiaucourt, F; Bölske, G; Leneguersh, B; Smith, D; Wesonga, H

    1996-12-01

    The diagnosis of contagious caprine pleuropneumonia (CCPP) has often been considered difficult. This is because of the confusion that can arise with other mycoplasmoses of small ruminants. Symptoms and lesions can be similar and the isolation of M. capricolum subsp. capripneumoniae (MccF38) requires skilled technicians. Once MccF38 strains are isolated, their identification should not be difficult. New techniques, such as polymerase chain reaction, now offer the possibility of identifying MccF38 directly from dried samples. However, the isolation of MccF38 strains is always required for an official declaration of infection. Until now, the official serological test has been the complement fixation test; the main drawbacks being lack of sensitivity and specificity and also the short persistence of antibodies detected by this technique. The specific competition enzyme-linked immunosorbent assay has now been developed and should enable wide serological enquiries to determine the real prevalence of the disease. Antibiotic treatments are effective but may not prevent persistence in latent carriers. An inactivated vaccine with saponin as an adjuvant has been produced in Kenya, which protects goats for approximately one year. PMID:9190021

  18. INFECTION WITH FOOT-AND-MOUTH DISEASE VIRUS CAUSES LOSS OF CIRCULATING PLASMACYTOID DENDRITIC CELLS AND ABROGATES THE INTERFERON ALPHA RESPONSE TO TLR AGONISTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immune evasion by pathogens is often critical to virulence and spread of the infectious agent. Foot-and-mouth disease virus (FMDV) is considered one of the most contagious infections known yet is very sensitive to both type I and type II interferons (IFN). In many species including swine, plasmacyto...

  19. The dynamics of sexual contact networks: effects on disease spread and control.

    PubMed

    Robinson, Katy; Cohen, Ted; Colijn, Caroline

    2012-03-01

    Sexually transmitted pathogens persist in populations despite the availability of biomedical interventions and knowledge of behavioural changes that would reduce individual-level risk. While behavioural risk factors are shared between many sexually transmitted infections, the prevalence of these diseases across different risk groups varies. Understanding this heterogeneity and identifying better control strategies depends on an improved understanding of the complex social contact networks over which pathogens spread. To date, most efforts to study the impact of sexual network structure on disease dynamics have focused on static networks. However, the interaction between the dynamics of partnership formation and dissolution and the dynamics of transmission plays a role, both in restricting the effective network accessible to the pathogen, and in modulating the transmission dynamics. We present a simple method to simulate dynamical networks of sexual partnerships. We inform the model using survey data on sexual attitudes and lifestyles, and investigate how the duration of infectiousness changes the effective contact network over which disease may spread. We then simulate several control strategies: screening, vaccination and behavioural interventions. Previous theory and research has advanced the importance of core groups for spread and control of STD. Our work is consistent with the importance of core groups, but extends this idea to consider how the duration of infectiousness associated with a particular pathogen interacts with host behaviours to define these high risk subpopulations. Characteristics of the parts of the network accessible to the pathogen, which represent the network structure of sexual contacts from the "point of view" of the pathogen, are substantially different from those of the network as a whole. The pathogen itself plays an important role in determining this effective network structure; specifically, we find that if the pathogen's duration of infectiousness is short, infection is more concentrated in high-activity, high-concurrency individuals even when all other factors are held constant. Widespread screening programmes would be enhanced by follow-up interventions targeting higher-risk individuals, because screening shortens the expected duration of infectiousness and causes a greater relative decrease in prevalence among lower-activity than in higher-activity individuals. Even for pathogens with longer durations of infectiousness, our findings suggest that targeting vaccination and behavioural interventions towards high-activity individuals provides comparable benefits to population-wide interventions. PMID:22248701

  20. The risk of disease to great apes: simulating disease spread in orang-utan (Pongo pygmaeus wurmbii) and chimpanzee (Pan troglodytes schweinfurthii) association networks.

    PubMed

    Carne, Charlotte; Semple, Stuart; Morrogh-Bernard, Helen; Zuberbühler, Klaus; Lehmann, Julia

    2014-01-01

    All great ape species are endangered, and infectious diseases are thought to pose a particular threat to their survival. As great ape species vary substantially in social organisation and gregariousness, there are likely to be differences in susceptibility to disease types and spread. Understanding the relation between social variables and disease is therefore crucial for implementing effective conservation measures. Here, we simulate the transmission of a range of diseases in a population of orang-utans in Sabangau Forest (Central Kalimantan) and a community of chimpanzees in Budongo Forest (Uganda), by systematically varying transmission likelihood and probability of subsequent recovery. Both species have fission-fusion social systems, but differ considerably in their level of gregariousness. We used long-term behavioural data to create networks of association patterns on which the spread of different diseases was simulated. We found that chimpanzees were generally far more susceptible to the spread of diseases than orang-utans. When simulating different diseases that varied widely in their probability of transmission and recovery, it was found that the chimpanzee community was widely and strongly affected, while in orang-utans even highly infectious diseases had limited spread. Furthermore, when comparing the observed association network with a mean-field network (equal contact probability between group members), we found no major difference in simulated disease spread, suggesting that patterns of social bonding in orang-utans are not an important determinant of susceptibility to disease. In chimpanzees, the predicted size of the epidemic was smaller on the actual association network than on the mean-field network, indicating that patterns of social bonding have important effects on susceptibility to disease. We conclude that social networks are a potentially powerful tool to model the risk of disease transmission in great apes, and that chimpanzees are particularly threatened by infectious disease outbreaks as a result of their social structure. PMID:24740263

  1. The Risk of Disease to Great Apes: Simulating Disease Spread in Orang-Utan (Pongo pygmaeus wurmbii) and Chimpanzee (Pan troglodytes schweinfurthii) Association Networks

    PubMed Central

    Carne, Charlotte; Semple, Stuart; Morrogh-Bernard, Helen; Zuberbühler, Klaus; Lehmann, Julia

    2014-01-01

    All great ape species are endangered, and infectious diseases are thought to pose a particular threat to their survival. As great ape species vary substantially in social organisation and gregariousness, there are likely to be differences in susceptibility to disease types and spread. Understanding the relation between social variables and disease is therefore crucial for implementing effective conservation measures. Here, we simulate the transmission of a range of diseases in a population of orang-utans in Sabangau Forest (Central Kalimantan) and a community of chimpanzees in Budongo Forest (Uganda), by systematically varying transmission likelihood and probability of subsequent recovery. Both species have fission-fusion social systems, but differ considerably in their level of gregariousness. We used long-term behavioural data to create networks of association patterns on which the spread of different diseases was simulated. We found that chimpanzees were generally far more susceptible to the spread of diseases than orang-utans. When simulating different diseases that varied widely in their probability of transmission and recovery, it was found that the chimpanzee community was widely and strongly affected, while in orang-utans even highly infectious diseases had limited spread. Furthermore, when comparing the observed association network with a mean-field network (equal contact probability between group members), we found no major difference in simulated disease spread, suggesting that patterns of social bonding in orang-utans are not an important determinant of susceptibility to disease. In chimpanzees, the predicted size of the epidemic was smaller on the actual association network than on the mean-field network, indicating that patterns of social bonding have important effects on susceptibility to disease. We conclude that social networks are a potentially powerful tool to model the risk of disease transmission in great apes, and that chimpanzees are particularly threatened by infectious disease outbreaks as a result of their social structure. PMID:24740263

  2. Analytical methods for quantifying environmental connectivity for the control and surveillance of infectious disease spread

    PubMed Central

    Remais, Justin; Akullian, Adam; Ding, Lu; Seto, Edmund

    2010-01-01

    The sustained transmission and spread of environmentally mediated infectious diseases is governed in part by the dispersal of parasites, disease vectors and intermediate hosts between sites of transmission. Functional geospatial models can be used to quantify and predict the degree to which environmental features facilitate or limit connectivity between target populations, yet typical models are limited in their geographical and analytical approach, providing simplistic, global measures of connectivity and lacking methods to assess the epidemiological implications of fine-scale heterogeneous landscapes. Here, functional spatial models are applied to problems of surveillance and control of the parasitic blood fluke Schistosoma japonicum and its intermediate snail host Oncomelania haupensis in western China. We advance functional connectivity methods by providing an analytical framework to (i) identify nodes of transmission where the degree of connectedness to other villages, and thus the potential for disease spread, is higher than is estimated using Euclidean distance alone and (ii) (re)organize transmission sites into disease surveillance units based on second-order relationships among nodes using non-Euclidean distance measures, termed effective geographical distance (EGD). Functional environmental models are parametrized using ecological information on the target organisms, and pair-wise distributions of inter-node EGD are estimated. A Monte Carlo rank product analysis is presented to identify nearby nodes under alternative distance models. Nodes are then iteratively embedded into EGD space and clustered using a k-means algorithm to group villages into ecologically meaningful surveillance groups. A consensus clustering approach is taken to derive the most stable cluster structure. The results indicate that novel relationships between nodes are revealed when non-Euclidean, ecologically determined distance measures are used to quantify connectivity in heterogeneous landscapes. These connections are not evident when analysing nodes in Euclidean space, and thus surveillance and control activities planned using Euclidean distance measures may be suboptimal. The methods developed here provide a quantitative framework for assessing the effectiveness of ecologically grounded surveillance systems and of control and prevention strategies for environmentally mediated diseases. PMID:20164085

  3. Vaccination against contagious caprine pleuropneumonia caused by F38.

    PubMed

    Rurangirwa, F R; McGuire, T C; Chema, S; Kibor, A

    1987-06-01

    Only F38 isolates of mycoplasma cause classical contagious caprine pleuropneumonia (CCPP). Therefore, research has focused on the development of a vaccine that will prevent serious epidemics of the disease in goats. Goats immunized with two doses of a lyophilized preparation of isolated F38 organisms administered 4 weeks apart were completely immune to experimentally induced CCPP. The minimum immunizing dose was 0.15 mg, and this dose was still effective after storage for 14 months at 4 C and 22 C. The duration of immunity induced by a single dose of lyophilized F38 was at least 12 months. PMID:3312103

  4. A comprehensive review of the retroperitoneal anatomy, neoplasms, and pattern of disease spread.

    PubMed

    Osman, Sherif; Lehnert, Bruce E; Elojeimy, Saeed; Cruite, Irene; Mannelli, Lorenzo; Bhargava, Puneet; Moshiri, Mariam

    2013-01-01

    A clear understanding of the normal anatomy and pattern of disease spread is important in evaluating many retroperitoneal disorders. Primary retroperitoneal tumors are uncommon, accounting for 0.1%-0.2% of all malignancies in the body; 80%-90% of all primary retroperitoneal tumors are malignant. The primary retroperitoneal neoplasms can be divided into solid or cystic masses. The solid neoplasms can be classified according to their tissue of origin into 3 main categories: mesodermal tumors, neurogenic tumors, and extragonadal germ cell tumors. Computed tomography and magnetic resonance imaging play a vital role in the localization, characterization, evaluation of the extent of local invasion, assessment of metastases, and determination of treatment response for these tumors. The diagnosis of a primary retroperitoneal malignancy is often challenging owing to overlap of imaging findings. A definitive diagnosis can be established only at histopathologic analysis. However, knowledge of the important tumor characteristics, growth pattern, and vascularity can assist in narrowing the differential diagnosis. PMID:24070713

  5. Epidemic predictions in an imperfect world: modelling disease spread with partial data

    PubMed Central

    Dawson, Peter M.; Werkman, Marleen; Brooks-Pollock, Ellen; Tildesley, Michael J.

    2015-01-01

    ‘Big-data’ epidemic models are being increasingly used to influence government policy to help with control and eradication of infectious diseases. In the case of livestock, detailed movement records have been used to parametrize realistic transmission models. While livestock movement data are readily available in the UK and other countries in the EU, in many countries around the world, such detailed data are not available. By using a comprehensive database of the UK cattle trade network, we implement various sampling strategies to determine the quantity of network data required to give accurate epidemiological predictions. It is found that by targeting nodes with the highest number of movements, accurate predictions on the size and spatial spread of epidemics can be made. This work has implications for countries such as the USA, where access to data is limited, and developing countries that may lack the resources to collect a full dataset on livestock movements. PMID:25948687

  6. Epidemic predictions in an imperfect world: modelling disease spread with partial data.

    PubMed

    Dawson, Peter M; Werkman, Marleen; Brooks-Pollock, Ellen; Tildesley, Michael J

    2015-06-01

    'Big-data' epidemic models are being increasingly used to influence government policy to help with control and eradication of infectious diseases. In the case of livestock, detailed movement records have been used to parametrize realistic transmission models. While livestock movement data are readily available in the UK and other countries in the EU, in many countries around the world, such detailed data are not available. By using a comprehensive database of the UK cattle trade network, we implement various sampling strategies to determine the quantity of network data required to give accurate epidemiological predictions. It is found that by targeting nodes with the highest number of movements, accurate predictions on the size and spatial spread of epidemics can be made. This work has implications for countries such as the USA, where access to data is limited, and developing countries that may lack the resources to collect a full dataset on livestock movements. PMID:25948687

  7. Avian influenza shedding patterns in waterfowl: implications for surveillance, environmentaltransmission, and disease spread

    USGS Publications Warehouse

    Henaux, V.; Samuel, M.D.

    2011-01-01

    Despite the recognized importance of fecal/oral transmission of low pathogenic avian influenza (LPAI) via contaminated wetlands, little is known about the length, quantity, or route of AI virus shed by wild waterfowl. We used published laboratory challenge studies to evaluate the length and quantity of low pathogenic (LP) and highly pathogenic (HP) virus shed via oral and cloacal routes by AI-infected ducks and geese, and how these factors might influence AI epidemiology and virus detection. We used survival analysis to estimate the duration of infection(from virus inoculation to the last day virus was shed) and nonlinear models to evaluate temporal patterns in virus shedding. We found higher mean virus titer and longer median infectious period for LPAI-infected ducks (1011.5 days in oral and cloacal swabs) than HPAI-infected ducks(5 days) and geese (7.5 days). Based on the median bird infectious dose, we found that environmental contamination is two times higher for LPAI- than HPAI-infectious ducks, which implies that susceptible birds may have a higher probability of infection during LPAI than HP AIoutbreaks. Less environmental contamination during the course of infection and previously documented shorter environmental persistence for HPAI than LPAI suggest that the environment is a less favorable reservoir for HPAI. The longer infectious period, higher virus titers, and subclinical infections with LPAI viruses favor the spread of these viruses by migratory birds in comparison to HPAI. Given the lack of detection of HPAI viruses through worldwide surveillance,we suggest monitoring for AI should aim at improving our understanding of AI dynamics (inparticular, the role of the environment and immunity) using long-term comprehensive live bird, serologic, and environmental sampling at targeted areas. Our findings on LPAI and HPAIshedding patterns over time provide essential information to parameterize environmental transmission and virus spread in predictive epizootio logic models of disease risks. ?? Wildlife Disease Association 2011.

  8. A point pattern model of the spread of foot-and-mouth disease.

    PubMed

    Gerbier, G; Bacro, J N; Pouillot, R; Durand, B; Moutou, F; Chadoeuf, J

    2002-11-29

    The spatial spread of foot-and-mouth disease (FMD) is influenced by several sources of spatial heterogeneity: heterogeneity of the exposure to the virus, heterogeneity of the animal density and heterogeneity of the networks formed by the contacts between farms. A discrete space model assuming that farms can be reduced to points is proposed to handle these different factors. The farm-to-farm process of transmission of the infection is studied using point-pattern methodology. Farm management, commercial exchanges, possible airborne transmission, etc. cannot be explicitly taken into account because of lack of data. These latter factors are introduced via surrogate variables such as herd size and distance between farms. The model is built on the calculation of an infectious potential for each farm. This method has been applied to the study of the 1967-1968 FMD epidemic in UK and allowed us to evaluate the spatial variation of the probability of infection during this epidemic. Maximum likelihood estimation has been conducted conditional on the absence of data concerning the farms which were not infected during the epidemic. Model parameters have then been tested using an approximated conditional-likelihood ratio test. In this case study, results and validation are limited by the lack of data, but this model can easily be extended to include other information such as the effect of wind direction and velocity on airborne spread of the virus or the complex interactions between the locations of farms and the herd size. It can also be applied to other diseases where point approximation is convenient. In the context of an increase of animal density in some areas, the model explicitly incorporates the density and known epidemiological characteristics (e.g. incubation period) in the calculation of the probability of FMD infection. Control measures such as vaccination or slaughter can be simply introduced, respectively, as a reduction of the susceptible population or as a reduction of the source of infection. PMID:12419598

  9. Controlling wildlife fungal disease spread: in vitro efficacy of disinfectants against Batrachochytrium dendrobatidis and Mucor amphibiorum.

    PubMed

    Webb, Rebecca; Philips, Annie; Speare, Rick; Connolly, Joanne; Berger, Lee

    2012-06-13

    Chytridiomycosis in amphibians, and mucormycosis in the platypus Ornithorhynchus anatinus and amphibians, are serious fungal diseases affecting these aquatic taxa. In Tasmania, Australia, the fungi that cause these diseases overlap in range along with Phytophthora cinnamomi (Pc), an invasive fungal plant pathogen. To identify disinfectants that may be useful to reduce anthropogenic spread of these fungi to uninfected wilderness areas, for example by bush walkers and forestry or fire-fighting operations, we tested 3 disinfectants and a fire-fighting foam against Mucor amphibiorum (Ma) and tested 1 disinfectant and the foam against Batrachochytrium dendrobatidis (Bd). Combining the present study with previous work we found Bd was more susceptible to all 4 chemicals than Ma. Phytoclean, a disinfectant used at 2 to 10% for 30 s to control Pc, killed cultures of Bd at 0.075% and Ma at 5%, when also applied for 30 s. The disinfectant F10sc was not effective against Ma at standard exposures, but previous work shows Bd is killed at 0.03% with a 1 min exposure. Path-X is effective against Bd at 0.001% with a 30 s exposure and killed Ma at 1% with a 5 min exposure. Forexpan S, a foam added to water at 0.1 to 1% to control forest fires, killed Bd but not Ma when used at 1% for 2 min. Therefore, Phytoclean and Path-X have broader efficacy, although Path-X has not been trialled against Pc. Interestingly a positive mating strain of Ma (from a platypus) was more resistant to disinfectants than a negative strain (from a frog). Current protocols against Pc that involve high concentrations (10%) of Phytoclean are likely to reduce spread of pathogenic wildlife fungi, which is important for protecting biodiversity. PMID:22691980

  10. Homogenization, sex, and differential motility predict spread of chronic wasting disease in mule deer in southern Utah.

    PubMed

    Garlick, Martha J; Powell, James A; Hooten, Mevin B; MacFarlane, Leslie R

    2014-08-01

    Chronic wasting disease (CWD) is an infectious prion disease that affects mule deer, along with other Cervids. It is a slow-developing, fatal disease which is rare in the free-ranging deer population of Utah. We present a sex-structured, spatial model for the spread of CWD over heterogeneous landscapes, incorporating both horizontal and environmental transmission pathways. To connect the local movement of deer to the regional spread of CWD, we use ecological diffusion with motility coefficients estimated from mule deer movement data. Ecological diffusion allows for aggregation of populations in desirable habitats and therefore allows for an interaction between density dependent disease transmission and landscape structure. The major innovation presented is use of homogenization to accelerate simulations of disease spread in southeastern Utah, from the La Sal Mountains near Moab to the Abajo Mountains near Monticello. The homogenized model provides accuracy while maintaining fidelity to small-scale habitat effects on deer distribution, including differential aggregation in land cover types with high residence times, with errors comparable to the order parameter measuring separation of small and large scales ([Formula: see text] in this case). We use the averaged coefficients from the homogenized model to explore asymptotic invasion speed and the impact of current population size on disease spread in southeastern Utah. PMID:23846241

  11. Do dogs (Canis familiaris) show contagious yawning?

    PubMed

    Harr, Aimee L; Gilbert, Valerie R; Phillips, Kimberley A

    2009-11-01

    We report an experimental investigation into whether domesticated dogs display contagious yawning. Fifteen dogs were shown video clips of (1) humans and (2) dogs displaying yawns and open-mouth expressions (not yawns) to investigate whether dogs showed contagious yawning to either of these social stimuli. Only one dog performed significantly more yawns during or shortly after viewing yawning videos than to the open-mouth videos, and most of these yawns occurred to the human videos. No dogs showed significantly more yawning to the open-mouth videos (human or dog). The percentage of dogs showing contagious yawning was less than chimpanzees and humans showing this behavior, and considerably less than a recently published report investigating this behavior in dogs (Joly-Mascheroni et al. in Biol Lett 4:446-448, 2008). PMID:19452178

  12. Uncertainty in predictions of disease spread and public health responses to bioterrorism and emerging diseases

    PubMed Central

    Elderd, Bret D.; Dukic, Vanja M.; Dwyer, Greg

    2006-01-01

    Concerns over bioterrorism and emerging diseases have led to the widespread use of epidemic models for evaluating public health strategies. Partly because epidemic models often capture the dynamics of prior epidemics remarkably well, little attention has been paid to how uncertainty in parameter estimates might affect model predictions. To understand such effects, we used Bayesian statistics to rigorously estimate the uncertainty in the parameters of an epidemic model, focusing on smallpox bioterrorism. We then used a vaccination model to translate the uncertainty in the model parameters into uncertainty in which of two vaccination strategies would provide a better response to bioterrorism, mass vaccination, or vaccination of social contacts, so-called “trace vaccination.” Our results show that the uncertainty in the model parameters is remarkably high and that this uncertainty has important implications for vaccination strategies. For example, under one plausible scenario, the most likely outcome is that mass vaccination would save ?100,000 more lives than trace vaccination. Because of the high uncertainty in the parameters, however, there is also a substantial probability that mass vaccination would save 200,000 or more lives than trace vaccination. In addition to providing the best response to the most likely outcome, mass vaccination thus has the advantage of preventing outcomes that are only slightly less likely but that are substantially more horrific. Rigorous estimates of uncertainty thus can reveal hidden advantages of public health strategies, suggesting that formal uncertainty estimation should play a key role in planning for epidemics. PMID:17030819

  13. Lymphangitic spread from the appendiceal adenocarcinoma to the ileocecal valve, mimicking Crohn’s disease

    PubMed Central

    Murdock, Tricia; Lim, Nicholas; Zenali, Maryam

    2015-01-01

    Due to the anatomical peculiarity of the appendix, diagnosis of tumors arising from this area can be challenging by clinicoradiologic means. We report a case of a rare primary appendiceal signet ring carcinoma with an uncommon presentation. An 86-year-old woman was admitted to our hospital with subacute epigastric pain. Computed tomography demonstrated bowel wall thickening with fat stranding in the ileocecal region. The leading diagnostic consideration was inflammatory bowel disease. Upon colonoscopy, a swollen, distorted ileocecal valve was identified. The remaining colon was otherwise unremarkable. Extensive biopsy sampling of the ileocecal region and colon was performed. A lymphangitic signet ring carcinoma within the ileocecal region was diagnosed on biopsy; there was no dysplasia or carcinoma of the remaining biopsies. By cytomorphology and immunoprofile, a lymphangitic signet ring carcinoma of appendiceal origin was the primary consideration, further confirmed upon subsequent laparotomy. This case represents an unusual pattern of appendiceal tumor spread with localized, lymphangitic involvement, creating a milieu which closely simulates Crohn’s disease on imaging modalities. PMID:25717258

  14. Birth and death of links control disease spreading in empirical contact networks

    NASA Astrophysics Data System (ADS)

    Holme, Petter; Liljeros, Fredrik

    2014-05-01

    We investigate what structural aspects of a collection of twelve empirical temporal networks of human contacts are important to disease spreading. We scan the entire parameter spaces of the two canonical models of infectious disease epidemiology--the Susceptible-Infectious-Susceptible (SIS) and Susceptible-Infectious-Removed (SIR) models. The results from these simulations are compared to reference data where we eliminate structures in the interevent intervals, the time to the first contact in the data, or the time from the last contact to the end of the sampling. The picture we find is that the birth and death of links, and the total number of contacts over a link, are essential to predict outbreaks. On the other hand, the exact times of contacts between the beginning and end, or the interevent interval distribution, do not matter much. In other words, a simplified picture of these empirical data sets that suffices for epidemiological purposes is that links are born, is active with some intensity, and die.

  15. Hand, Foot and Mouth Disease in China: Patterns of Spread and Transmissibility during 2008-2009

    PubMed Central

    Wang, Yu; Feng, Zijian; Yang, Yang; Self, Steve; Gao, Yongjun; Longini, Ira M.; Wakefield, Jon; Zhang, Jing; Wang, Liping; Chen, Xi; Yao, Lena; Stanaway, Jeffrey D.; Wang, Zijun; Yang, Weizhong

    2011-01-01

    Background Large outbreaks of hand, foot and mouth disease (HFMD) were observed in both 2008 and 2009 in China. Methods Using the national surveillance data since May 2, 2008, epidemiological characteristics of the outbreaks are summarized, and the transmissibility of the disease and the effects of potential risk factors were evaluated via a susceptible-infectious-recovered transmission model. Results Children of 1.0–2.9 years were the most susceptible group to HFMD (odds ratios [OR] > 2.3 as compared to other age groups). Infant cases had the highest incidences of severe disease (ORs > 1.4) and death (ORs > 2.4), as well as the longest delay from symptom onset to diagnosis (2.3 days). Males were more susceptible to HFMD than females (OR=1.56 [95% confidence interval=1.56, 1.57]). An one day delay in diagnosis was associated with increases in the odds of severe disease by 40.3% [38.7%, 41.9%] and in the odds of death by 53.7% [43.6%, 64.5%]. Compared to Coxsackie A16, enterovirus (EV) 71 is more strongly associated with severe disease (OR=15.6 [13.4, 18.1]) and death (OR=40.7 [13.0, 127.3]). The estimated local effective reproductive numbers among prefectures ranged from 1.4 to 1.6 (median=1.4) in spring and stayed below 1.2 in other seasons. A higher risk of transmission was associated with temperatures in the range of 70-80F, higher relative humidity, wind speed, precipitation, population density, and the periods in which schools were open. Conclusion HFMD is a moderately transmittable infectious disease, mainly among pre-school children. EV71 was responsible for most severe cases and fatalities. Mixing of asymptomatically infected children in schools might have contributed to the spread of HFMD. Timely diagnosis may be a key to reducing the high mortality rate in infants. PMID:21968769

  16. Development of loop-mediated isothermal amplification test for the diagnosis of contagious agalactia in goats.

    PubMed

    Rekha, Valsala; Rana, Rajneesh; Thomas, Prasad; Viswas, Konasagara Nagaleekar; Singh, Vijendra Pal; Agarwal, Rajesh Kumar; Arun, Thachappully Remesh; Karthik, Kumaragurubaran; Sophia, Inbaraj

    2015-03-01

    Contagious agalactia is a highly infectious disease affecting sheep and goats, mainly caused by Mycoplasma agalactiae. Although various tests are available for diagnosis of contagious agalactia, none of them is credited with the capacity to provide rapid and cost-effective diagnosis. This article reports the development of loop-mediated isothermal amplification (LAMP) test targeting the p40 gene of M. agalactiae, for the diagnosis of classical contagious agalactia. Optimum amplification was obtained at 58 °C in 70 min. The developed test was found to be 100-fold more sensitive than PCR and detected up to 20-fg level of DNA. The test was also superior to conventional PCR in detecting from artificially contaminated milk, i.e. 10(4)-fold more sensitive. The developed LAMP test could detect up to 10 cfu/ml of artificially contaminated milk, indicating its potential for being developed as a field test for rapid and sensitive diagnosis. PMID:25616985

  17. An estimation of the economic impact of contagious bovine pleuropneumonia in Africa

    Microsoft Academic Search

    N. E. Tambi; W. O. Maina; C. Ndi

    Summary Contagious bovine pleuropneumonia (CBPP) is a disease that causes high morbidity and mortality losses to cattle. The financial implications of these losses are of great significance to cattle owners. Control of CBPP is therefore important as a way to salvage the losses and increase the incomes of cattle owners. This study estimated the economic cost of CBPP and the

  18. Social modulation of contagious yawning in wolves.

    PubMed

    Romero, Teresa; Ito, Marie; Saito, Atsuko; Hasegawa, Toshikazu

    2014-01-01

    On the basis of observational and experimental evidence, several authors have proposed that contagious yawn is linked to our capacity for empathy, thus presenting a powerful tool to explore the root of empathy in animal evolution. The evidence for the occurrence of contagious yawning and its link to empathy, however, is meagre outside primates and only recently domestic dogs have demonstrated this ability when exposed to human yawns. Since dogs are unusually skillful at reading human communicative behaviors, it is unclear whether this phenomenon is deeply rooted in the evolutionary history of mammals or evolved de novo in dogs as a result of domestication. Here we show that wolves are capable of yawn contagion, suggesting that such ability is a common ancestral trait shared by other mammalian taxa. Furthermore, the strength of the social bond between the model and the subject positively affected the frequency of contagious yawning, suggesting that in wolves the susceptibility of yawn contagion correlates with the level of emotional proximity. Moreover, female wolves showed a shorter reaction time than males when observing yawns of close associates, suggesting that females are more responsive to their social stimuli. These results are consistent with the claim that the mechanism underlying contagious yawning relates to the capacity for empathy and suggests that basic building blocks of empathy might be present in a wide range of species. PMID:25162677

  19. Social Modulation of Contagious Yawning in Wolves

    PubMed Central

    Romero, Teresa; Ito, Marie; Saito, Atsuko; Hasegawa, Toshikazu

    2014-01-01

    On the basis of observational and experimental evidence, several authors have proposed that contagious yawn is linked to our capacity for empathy, thus presenting a powerful tool to explore the root of empathy in animal evolution. The evidence for the occurrence of contagious yawning and its link to empathy, however, is meagre outside primates and only recently domestic dogs have demonstrated this ability when exposed to human yawns. Since dogs are unusually skilful at reading human communicative behaviors, it is unclear whether this phenomenon is deeply rooted in the evolutionary history of mammals or evolved de novo in dogs as a result of domestication. Here we show that wolves are capable of yawn contagion, suggesting that such ability is a common ancestral trait shared by other mammalian taxa. Furthermore, the strength of the social bond between the model and the subject positively affected the frequency of contagious yawning, suggesting that in wolves the susceptibility of yawn contagion correlates with the level of emotional proximity. Moreover, female wolves showed a shorter reaction time than males when observing yawns of close associates, suggesting that females are more responsive to their social stimuli. These results are consistent with the claim that the mechanism underlying contagious yawning relates to the capacity for empathy and suggests that basic building blocks of empathy might be present in a wide range of species. PMID:25162677

  20. Contagious Development Neighbor Interactions in Deforestation

    E-print Network

    Pfaff, Alex

    Contagious Development Neighbor Interactions in Deforestation Juan A. Robalino EfD Initiative-CATIE Alexander Pfaff Duke University October 2009 Abstract We estimate neighbor interactions in deforestation instrument for neighbors' deforestation using the slopes of neighbors' and neigh- bors' neighbors' parcels

  1. Annex A -Newly arrived pests and diseases Organism(s) Means of spread Control measures Control approaches

    E-print Network

    of development and population increase in relation to environmental temperatures. Natural controls: parasitesAnnex A - Newly arrived pests and diseases Organism(s) Means of spread Control measures Control to work with others? Who? Impact of research on control Likelihood of developing practical control options

  2. Trichothecene-Genotypes Play a Role in Fusarium Head Blight Disease Spread and Trichothecene Accumulation in Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the current study, we evaluated the impact of the observed North American evolutionary shift in the Fusarium graminearum complex on disease spread, kernel damage, and trichothecene accumulation in resistant and susceptible wheat genotypes. Four inocula were prepared using composites of F. gramin...

  3. Epitope spreading

    Microsoft Academic Search

    Carol J Vanderlugt; Stephen D Miller

    1996-01-01

    Epitope (determinant) spreading is the development of immune responses to endogenous epitopes secondary to the release of self antigens during a chronic autoimmune or inflammatory response. The past year has seen considerable advances in our understanding of the contribution of epitope spreading to the chronic pathogenesis of experimental T-cell-mediated and antibody-mediated autoimmune diseases. Most significantly, conclusive functional evidence for a

  4. Climate Change, Extreme Weather Events, and Fungal Disease Emergence and Spread

    NASA Technical Reports Server (NTRS)

    Tucker, Compton J.; Yager, Karina; Anyamba, Assaf; Linthicum, Kenneth J.

    2011-01-01

    Empirical evidence from multiple sources show the Earth has been warming since the late 19th century. More recently, evidence for this warming trend is strongly supported by satellite data since the late 1970s from the cryosphere, atmosphere, oceans, and land that confirms increasing temperature trends and their consequences (e.g., reduced Arctic sea ice, rising sea level, ice sheet mass loss, etc.). At the same time, satellite observations of the Sun show remarkably stable solar cycles since the late 1970s, when direct observations of the Sun's total solar irradiance began. Numerical simulation models, driven in part by assimilated satellite data, suggest that future-warming trends will lead to not only a warmer planet, but also a wetter and drier climate depending upon location in a fashion consistent with large-scale atmospheric processes. Continued global warming poses new opportunities for the emergence and spread of fungal disease, as climate systems change at regional and global scales, and as animal and plant species move into new niches. Our contribution to this proceedings is organized thus: First, we review empirical evidence for a warming Earth. Second, we show the Sun is not responsible for the observed warming. Third, we review numerical simulation modeling results that project these trends into the future, describing the projected abiotic environment of our planet in the next 40 to 50 years. Fourth, we illustrate how Rift Valley fever outbreaks have been linked to climate, enabling a better understanding of the dynamics of these diseases, and how this has led to the development of an operational predictive outbreak model for this disease in Africa. Fifth, We project how this experience may be applicable to predicting outbreaks of fungal pathogens in a warming world. Lastly, we describe an example of changing species ranges due to climate change, resulting from recent warming in the Andes and associated glacier melt that has enabled amphibians to colonize higher elevation lakes, only to be followed shortly by the emergence of fungal disease in the new habitats.

  5. Aedes albopictus in the United States: rapid spread of a potential disease vector.

    PubMed

    Moore, C G; Francy, D B; Eliason, D A; Monath, T P

    1988-09-01

    Aedes albopictus, the Asian "tiger mosquito," was found in Houston, Texas, in 1985. Aedes albopictus is primarily a forest edge inhabiting species that has readily adapted to the container habitats produced by humans. Although not yet incriminated in the spread of any disease in the Americas, it has been repeatedly implicated in epidemic dengue and dengue hemorrhagic fever transmission in Asia. It is a competent laboratory vector of La Crosse, yellow fever and other viruses, and can transovarially transmit at least 15 viruses. In 1986, Ae. albopictus was found in many other Texas counties, and in Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Louisiana, Mississippi, Missouri, Ohio, and Tennessee. In 1987, infestations were discovered in Delaware, Kentucky, Maryland, and North Carolina. Aedes albopictus and other exotic species were intercepted in shipments of used tires entering the United States from Asia. All such tires must now be free of mosquitoes before entering the country. Control over the movement and storage of tires, a strong source reduction program, and intensive public education can solve the albopictus problem. PMID:3058869

  6. Connectivity of the American Agricultural Landscape: Assessing the National Risk of Crop Pest and Disease Spread

    NSDL National Science Digital Library

    Karen Garrett (Kansas State University; Department of Plant Pathology)

    2009-02-01

    More than two-thirds of cropland in the United States is devoted to the production of just four crop speciesâ??maize, wheat, soybeans, and cottonâ??raising concerns that homogenization of the American agricultural landscape could facilitate widespread disease and pest outbreaks, compromising the national food supply. As a new component in national agricultural risk assessment, we employed a graph-theoretic approach to examine the connectivity of these crops across the United States. We used county crop acreage to evaluate the landscape resistance to transmissionâ??the degree to which host availability limits spread in any given regionâ??for pests or pathogens dependent on each crop. For organisms that can disperse under conditions of lower host availability, maize and soybean are highly connected at a national scale, compared with the more discrete regions of wheat and cotton production. Determining the scales at which connectivity becomes disrupted for organisms with different dispersal abilities may help target rapid-response regions and the development of strategic policies to enhance agricultural landscape heterogeneity.

  7. Preventing the spread of Alzheimer's disease neuropathology: a role for calcilytics?

    PubMed

    Chiarini, Anna; Gardenal, Emanuela; Whitfield, James F; Chakravarthy, Balu; Armato, Ubaldo; Dal Pra, Ilaria

    2015-01-01

    The "amyloid cascade hypothesis" posits that an extracellular build-up of amyloid-? oligomers (A?-os) and polymers (fibrils) subsequently inducing toxic hyperphosphorylated (p)-Tau oligomers (p-Tau-os) and neurofibrillary tangles starts the sporadic late-onset Alzheimer's disease (LOAD) in the aged lateral entorhinal cortex. Conversely, mutated genes cause a diffuse cerebral A?s/A?-os overproduction promoting early-onset familiar AD (EOFAD). Surplus exogenous A?-os exert toxic actions at several levels. They reach the nuclei of human astrocyte-neurons teams (ANTs) to enhance the transcription of A? precursor protein (APP) and ?-secretase/BACE1 genes. The overexpressed APP and BACE1 proteins act in concert with ?-secretase to overproduce endogenous A?s/A?-os, of which a few enter the nuclei to upkeep A?s overproduction, while the rest gather in the cytoplasm, damage mitochondria, and are oversecreted. Simultaneously, extracellular A?-os bind the ANTs' calcium-sensing receptors (CaSRs) activating signalings that hinder the proteolysis and hence favor the surplus hoarding/secretion of A?s/A?-os. Overreleased A?-os spread, reach growing numbers of adjacent ANTs to recruit them to overproduce/oversecrete further A?-os amounts via the just mentioned mechanisms. Alongside, A?•CaSR signalings elicit a noxious overproduction/overrelease of nitric oxide (NO) and vascular endothelial growth factor (VEGF)-A from ANTs' astrocytes. While astrocytes survive the toxic onslaught, neurons die. Thus, AD progression is driven by ceaselessly self-sustaining neurotoxic cycles, which engender first A?-os and later p-Tau-os that cooperatively destroy increasingly wider cognition-related cortical areas. Notably, a highly selective allosteric CaSR antagonist (calcilytic), like NPS 2143, does preserve human cortical postnatal HCN-1A neurons viability notwithstanding the presence of exogenous A?-os by suppressing the otherwise elicited oversecretion and spread of newly synthesized A?-os. Therefore, if given at minimal cognitive impairment or earlier stages, calcilytics could halt AD progression and preserve the patients' cortical neurons, cognitive abilities, and eventually life. PMID:25941885

  8. Predictive Modelling of Contagious Deforestation in the Brazilian Amazon

    PubMed Central

    Rosa, Isabel M. D.; Purves, Drew; Souza, Carlos; Ewers, Robert M.

    2013-01-01

    Tropical forests are diminishing in extent due primarily to the rapid expansion of agriculture, but the future magnitude and geographical distribution of future tropical deforestation is uncertain. Here, we introduce a dynamic and spatially-explicit model of deforestation that predicts the potential magnitude and spatial pattern of Amazon deforestation. Our model differs from previous models in three ways: (1) it is probabilistic and quantifies uncertainty around predictions and parameters; (2) the overall deforestation rate emerges “bottom up”, as the sum of local-scale deforestation driven by local processes; and (3) deforestation is contagious, such that local deforestation rate increases through time if adjacent locations are deforested. For the scenarios evaluated–pre- and post-PPCDAM (“Plano de Açăo para Proteçăo e Controle do Desmatamento na Amazônia”)–the parameter estimates confirmed that forests near roads and already deforested areas are significantly more likely to be deforested in the near future and less likely in protected areas. Validation tests showed that our model correctly predicted the magnitude and spatial pattern of deforestation that accumulates over time, but that there is very high uncertainty surrounding the exact sequence in which pixels are deforested. The model predicts that under pre-PPCDAM (assuming no change in parameter values due to, for example, changes in government policy), annual deforestation rates would halve between 2050 compared to 2002, although this partly reflects reliance on a static map of the road network. Consistent with other models, under the pre-PPCDAM scenario, states in the south and east of the Brazilian Amazon have a high predicted probability of losing nearly all forest outside of protected areas by 2050. This pattern is less strong in the post-PPCDAM scenario. Contagious spread along roads and through areas lacking formal protection could allow deforestation to reach the core, which is currently experiencing low deforestation rates due to its isolation. PMID:24204776

  9. An investigation of auditory contagious yawning

    Microsoft Academic Search

    Stephen R. Arnott; Anthony Singhal; Melvyn A. Goodale

    2009-01-01

    Despite a widespread familiarity with the often compelling urge to yawn after perceiving someone else yawn, an understanding\\u000a of the neural mechanism underlying contagious yawning remains incomplete. In the present auditory fMRI study, listeners used\\u000a a 4-point scale to indicate how much they felt like yawning following the presentation of a yawn, breath, or scrambled yawn\\u000a sound. Not only were

  10. An investigation of auditory contagious yawning.

    PubMed

    Arnott, Stephen R; Singhal, Anthony; Goodale, Melvyn A

    2009-09-01

    Despite a widespread familiarity with the often compelling urge to yawn after perceiving someone else yawn, an understanding of the neural mechanism underlying contagious yawning remains incomplete. In the present auditory fMRI study, listeners used a 4-point scale to indicate how much they felt like yawning following the presentation of a yawn, breath, or scrambled yawn sound. Not only were yawn sounds given significantly higher ratings, a trait positively correlated with each individual's empathy measure, but relative to control stimuli, random effects analyses revealed enhanced hemodynamic activity in the right posterior inferior frontal gyrus (pIFG) in response to hearing yawns. Moreover, pIFG activity was greatest for yawn stimuli associated with high as opposed to low yawn ratings and for control sounds associated with equally high yawn ratings. These results support a relationship between contagious yawning and empathy and provide evidence for pIFG involvement in contagious yawning. A supplemental figure for this study may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental. PMID:19679768

  11. Risk of Foot-and-Mouth Disease spread due to sole occupancy authorities and linked cattle holdings.

    PubMed

    Orton, Richard J; Bessell, Paul R; Birch, Colin P D; O'Hare, Anthony; Kao, Rowland R

    2012-01-01

    Livestock movements in Great Britain are well recorded, have been extensively analysed with respect to their role in disease spread, and have been used in real time to advise governments on the control of infectious diseases. Typically, livestock holdings are treated as distinct entities that must observe movement standstills upon receipt of livestock, and must report livestock movements. However, there are currently two dispensations that can exempt holdings from either observing standstills or reporting movements, namely the Sole Occupancy Authority (SOA) and Cattle Tracing System (CTS) Links, respectively. In this report we have used a combination of data analyses and computational modelling to investigate the usage and potential impact of such linked holdings on the size of a Foot-and-Mouth Disease (FMD) epidemic. Our analyses show that although SOAs are abundant, their dynamics appear relatively stagnant. The number of CTS Links is also abundant, and increasing rapidly. Although most linked holdings are only involved in a single CTS Link, some holdings are involved in numerous links that can be amalgamated to form "CTS Chains" which can be both large and geographically dispersed. Our model predicts that under a worst case scenario of "one infected - all infected", SOAs do pose a risk of increasing the size (in terms of number of infected holdings) of a FMD epidemic, but this increase is mainly due to intra-SOA infection spread events. Furthermore, although SOAs do increase the geographic spread of an epidemic, this increase is predominantly local. Whereas, CTS Chains pose a risk of increasing both the size and the geographical spread of the disease substantially, under a worse case scenario. Our results highlight the need for further investigations into whether CTS Chains are transmission chains, and also investigations into intra-SOA movements and livestock distributions due to the lack of current data. PMID:22532841

  12. Be-CoDiS: An epidemiological model to predict the risk of human diseases spread worldwide. Application to the 2014 Ebola Virus Disease epidemic

    E-print Network

    Benjamin, Ivorra; Dične, Ngom

    2014-01-01

    Ebola virus disease is a lethal human and primate disease that currently requires a particular attention from the national and international health authorities due to important outbreaks concurring in some Western African countries and possible spread to other continents, which has already occurred in the USA and Spain. Regarding the emergency of this situation, there is a need of development of decision tools to help the authorities to focus their efforts in important factors that can help to eradicate Ebola. Mathematical modeling and, more precisely, epidemiological modeling can help to predict the possible evolution of the Ebola outbreaks and to give some recommendations in the region to be prioritized for surveillance. In this work, we present a first formulation of a new spatial-temporal epidemiological model, called Be-CoDiS (Between-COuntries Disease Spread), based on the combination of a deterministic Individual-Based model (modelling the interaction between countries, considered as individual) for be...

  13. Contagious caprine pleuropneumonia and other pulmonary mycoplasmoses of sheep and goats.

    PubMed

    Thiaucourt, F; Bölske, G

    1996-12-01

    Contagious caprine pleuropneumonia (CCPP) is now a well-defined disease that is caused by Mycoplasma capricolum subsp. capripneumoniae. CCPP is infectious, contagious and fulfils the classic Koch postulates that characterise such types of disease. The distribution of the disease is not exactly known, but reports of mycoplasma isolation and official declarations to the Office International des Epizooties (OIE) enable a probable distribution map to be obtained. There are many other mycoplasmas that can infect goat and sheep lungs and induce pleuropneumonia. However, pleuropneumonia is often restricted to young animals and the prominent symptom is mastitis in lactating does. Other symptoms may also occur, contributing to a syndrome that has been tentatively described in this paper as 'MAKePS syndrome' for mastitis, arthritis, keratitis, pneumonia and septicaemia. PMID:9190020

  14. Active surveillance of the aquatic environment for potential prediction, prevention and spread of water borne disease: the cholera paradigm

    NASA Astrophysics Data System (ADS)

    Huq, A.; Colwell, R.

    2011-12-01

    Based on results of ecological and epidemiological studies, occurrence and spread of certain diseases are more fully understood. Cholera is a major waterborne disease, that is relatively easily treatable and clearly preventable, yet tens of thousands die each year worldwide. A dose dependent disease, the infectious dose can vary from 103-106, depending on health status of the victim. Historically, cholera has been shown to spread from person to person. Furthermore, the disease is caused predominantly via ingestion of contaminated water and most of the outbreaks that have been recorded worldwide originated in a coastal region. Using appropriate detection methods, Vibrio cholerae can be isolated from samples collected from ponds, rivers, estuaries, and coastal waters globally. The populations of V. cholerae may vary in numbers during different seasons of the year. It is important to have a clear understanding of the distribution of the causative agent in the environment as such information can assist public health officials in taking action to prevent outbreaks of cholera. Thus an effective monitoring program is critical, particularly in light of climate change with temperature extremes more likely to be occurring. Based on a predictive model and results of ground truth data, temperature has been found to be a factor in the increase of V. cholerae in the environment. Correlation was observed with occurrence of cholera and both temperature and salinity. More recent research indicates additional factors need to be considered in predicting cholera epidemics, including the hydrology and disease dynamics.

  15. Preliminary field test of lyophilised contagious caprine pleuropneumonia vaccine.

    PubMed

    Rurangirwa, F R; McGuire, T C; Mbai, L; Ndung'u, L; Wambugu, A

    1991-03-01

    Fifty goats were immunised in the field against contagious caprine pleuropneumonia (CCPP) using a single dose (0.15 mg) of lyophilised, saponin killed Mycoplasma strain F38. Two months after vaccination, these goats together with 50 unimmunised control goats were challenged by contact with goats experimentally infected with CCPP. Twelve vaccinates and 14 controls died of diarrhoea due to salmonella infection during the first two weeks after challenge. The remaining immunised goats (38) with the exception of two goats which had elevated temperatures were protected from CCPP. Of the remaining 36 control goats, 30 contracted CCPP at a mean of 39 (+/- 14.3 SD) days after challenge and 27 of them died. These results show that the lyophilised killed F38 vaccine conferred 100 per cent protection against mortality and 95 per cent protection against clinical disease caused by Mycoplasma species strain F38. PMID:2034906

  16. Disease spread models to estimate highly uncertain emerging diseases losses for animal agriculture insurance policies: an application to the U.S. farm-raised catfish industry.

    PubMed

    Zagmutt, Francisco J; Sempier, Stephen H; Hanson, Terril R

    2013-10-01

    Emerging diseases (ED) can have devastating effects on agriculture. Consequently, agricultural insurance for ED can develop if basic insurability criteria are met, including the capability to estimate the severity of ED outbreaks with associated uncertainty. The U.S. farm-raised channel catfish (Ictalurus punctatus) industry was used to evaluate the feasibility of using a disease spread simulation modeling framework to estimate the potential losses from new ED for agricultural insurance purposes. Two stochastic models were used to simulate the spread of ED between and within channel catfish ponds in Mississippi (MS) under high, medium, and low disease impact scenarios. The mean (95% prediction interval (PI)) proportion of ponds infected within disease-impacted farms was 7.6% (3.8%, 22.8%), 24.5% (3.8%, 72.0%), and 45.6% (4.0%, 92.3%), and the mean (95% PI) proportion of fish mortalities in ponds affected by the disease was 9.8% (1.4%, 26.7%), 49.2% (4.7%, 60.7%), and 88.3% (85.9%, 90.5%) for the low, medium, and high impact scenarios, respectively. The farm-level mortality losses from an ED were up to 40.3% of the total farm inventory and can be used for insurance premium rate development. Disease spread modeling provides a systematic way to organize the current knowledge on the ED perils and, ultimately, use this information to help develop actuarially sound agricultural insurance policies and premiums. However, the estimates obtained will include a large amount of uncertainty driven by the stochastic nature of disease outbreaks, by the uncertainty in the frequency of future ED occurrences, and by the often sparse data available from past outbreaks. PMID:23560798

  17. Measures of concurrency in networks and the spread of infectious disease

    Microsoft Academic Search

    Martina Morris

    1996-01-01

    An investigation is made into the impact of concurrent partnerships on epidemic spread. Starting from a definition of concurrency on the level of individuals, the authors define ways to quantify concurrency on the population level. An index of concurrency based on graph theoretical considerations is introduced, and the way in which it is related to the degree distribution of the

  18. Individual variation in contagious yawning susceptibility is highly stable and largely unexplained by empathy or other known factors.

    PubMed

    Bartholomew, Alex J; Cirulli, Elizabeth T

    2014-01-01

    The contagious aspect of yawning is a well-known phenomenon that exhibits variation in the human population. Despite the observed variation, few studies have addressed its intra-individual reliability or the factors modulating differences in the susceptibility of healthy volunteers. Due to its obvious biological basis and impairment in diseases like autism and schizophrenia, a better understanding of this trait could lead to novel insights into these conditions and the general biological functioning of humans. We administered 328 participants a 3-minute yawning video stimulus, a cognitive battery, and a comprehensive questionnaire that included measures of empathy, emotional contagion, circadian energy rhythms, and sleepiness. Individual contagious yawning measurements were found to be highly stable across testing sessions, both in a lab setting and if administered remotely online, confirming that certain healthy individuals are less susceptible to contagious yawns than are others. Additionally, most individuals who failed to contagiously yawn in our study were not simply suppressing their reaction, as they reported not even feeling like yawning in response to the stimulus. In contrast to previous studies indicating that empathy, time of day, or intelligence may influence contagious yawning susceptibility, we found no influence of these variables once accounting for the age of the participant. Participants were less likely to show contagious yawning as their age increased, even when restricting to ages of less than 40 years. However, age was only able to explain 8% of the variability in the contagious yawn response. The vast majority of the variability in this extremely stable trait remained unexplained, suggesting that studies of its inheritance are warranted. PMID:24632594

  19. Individual Variation in Contagious Yawning Susceptibility Is Highly Stable and Largely Unexplained by Empathy or Other Known Factors

    PubMed Central

    Bartholomew, Alex J.; Cirulli, Elizabeth T.

    2014-01-01

    The contagious aspect of yawning is a well-known phenomenon that exhibits variation in the human population. Despite the observed variation, few studies have addressed its intra-individual reliability or the factors modulating differences in the susceptibility of healthy volunteers. Due to its obvious biological basis and impairment in diseases like autism and schizophrenia, a better understanding of this trait could lead to novel insights into these conditions and the general biological functioning of humans. We administered 328 participants a 3-minute yawning video stimulus, a cognitive battery, and a comprehensive questionnaire that included measures of empathy, emotional contagion, circadian energy rhythms, and sleepiness. Individual contagious yawning measurements were found to be highly stable across testing sessions, both in a lab setting and if administered remotely online, confirming that certain healthy individuals are less susceptible to contagious yawns than are others. Additionally, most individuals who failed to contagiously yawn in our study were not simply suppressing their reaction, as they reported not even feeling like yawning in response to the stimulus. In contrast to previous studies indicating that empathy, time of day, or intelligence may influence contagious yawning susceptibility, we found no influence of these variables once accounting for the age of the participant. Participants were less likely to show contagious yawning as their age increased, even when restricting to ages of less than 40 years. However, age was only able to explain 8% of the variability in the contagious yawn response. The vast majority of the variability in this extremely stable trait remained unexplained, suggesting that studies of its inheritance are warranted. PMID:24632594

  20. Computer animations stimulate contagious yawning in chimpanzees

    PubMed Central

    Campbell, Matthew W.; Carter, J. Devyn; Proctor, Darby; Eisenberg, Michelle L.; de Waal, Frans B. M.

    2009-01-01

    People empathize with fictional displays of behaviour, including those of cartoons and computer animations, even though the stimuli are obviously artificial. However, the extent to which other animals also may respond empathetically to animations has yet to be determined. Animations provide a potentially useful tool for exploring non-human behaviour, cognition and empathy because computer-generated stimuli offer complete control over variables and the ability to program stimuli that could not be captured on video. Establishing computer animations as a viable tool requires that non-human subjects identify with and respond to animations in a way similar to the way they do to images of actual conspecifics. Contagious yawning has been linked to empathy and poses a good test of involuntary identification and motor mimicry. We presented 24 chimpanzees with three-dimensional computer-animated chimpanzees yawning or displaying control mouth movements. The apes yawned significantly more in response to the yawn animations than to the controls, implying identification with the animations. These results support the phenomenon of contagious yawning in chimpanzees and suggest an empathic response to animations. Understanding how chimpanzees connect with animations, to both empathize and imitate, may help us to understand how humans do the same. PMID:19740888

  1. Computer animations stimulate contagious yawning in chimpanzees.

    PubMed

    Campbell, Matthew W; Carter, J Devyn; Proctor, Darby; Eisenberg, Michelle L; de Waal, Frans B M

    2009-12-01

    People empathize with fictional displays of behaviour, including those of cartoons and computer animations, even though the stimuli are obviously artificial. However, the extent to which other animals also may respond empathetically to animations has yet to be determined. Animations provide a potentially useful tool for exploring non-human behaviour, cognition and empathy because computer-generated stimuli offer complete control over variables and the ability to program stimuli that could not be captured on video. Establishing computer animations as a viable tool requires that non-human subjects identify with and respond to animations in a way similar to the way they do to images of actual conspecifics. Contagious yawning has been linked to empathy and poses a good test of involuntary identification and motor mimicry. We presented 24 chimpanzees with three-dimensional computer-animated chimpanzees yawning or displaying control mouth movements. The apes yawned significantly more in response to the yawn animations than to the controls, implying identification with the animations. These results support the phenomenon of contagious yawning in chimpanzees and suggest an empathic response to animations. Understanding how chimpanzees connect with animations, to both empathize and imitate, may help us to understand how humans do the same. PMID:19740888

  2. Minimal Contagious Sets in Random Regular Graphs

    NASA Astrophysics Data System (ADS)

    Guggiola, Alberto; Semerjian, Guilhem

    2015-01-01

    The bootstrap percolation (or threshold model) is a dynamic process modelling the propagation of an epidemic on a graph, where inactive vertices become active if their number of active neighbours reach some threshold. We study an optimization problem related to it, namely the determination of the minimal number of active sites in an initial configuration that leads to the activation of the whole graph under this dynamics, with and without a constraint on the time needed for the complete activation. This problem encompasses in special cases many extremal characteristics of graphs like their independence, decycling or domination number, and can also be seen as a packing problem of repulsive particles. We use the cavity method (including the effects of replica symmetry breaking), an heuristic technique of statistical mechanics many predictions of which have been confirmed rigorously in the recent years. We have obtained in this way several quantitative conjectures on the size of minimal contagious sets in large random regular graphs, the most striking being that 5-regular random graph with a threshold of activation of 3 (resp. 6-regular with threshold 4) have contagious sets containing a fraction (resp. ) of the total number of vertices. Equivalently these numbers are the minimal fraction of vertices that have to be removed from a 5-regular (resp. 6-regular) random graph to destroy its 3-core. We also investigated Survey Propagation like algorithmic procedures for solving this optimization problem on single instances of random regular graphs.

  3. A study on contagious caprine pleuropneumonia (CCPP) in goats at an export oriented abattoir, Debrezeit, Ethiopia.

    PubMed

    Eshetu, L; Yigezu, L; Asfaw, Y

    2007-08-01

    300 goat serum samples from an export-oriented abattoir were tested for contagious caprine pleuropneumonia antibodies by the complement fixation test. The disease prevalence was 31% with no significant differences (P > 0.05) between the regions "Borena", "Bale", "Afar" and "Jinka" or the age of the goats (P > 0.05). Gross pathology and histopathology of the lung primary lesions were indicative of pleuropneumonia caused by Mycoplasma capricolum subsp. capripneumoniae. PMID:17966273

  4. Modeling the spread and control of foot-and-mouth disease in Pennsylvania following its discovery and options for control

    PubMed Central

    Tildesley, Michael J.; Smith, Gary; Keeling, Matt J.

    2013-01-01

    In this paper, we simulate outbreaks of foot-and-mouth disease in the Commonwealth of Pennsylvania, USA – after the introduction of a state-wide movement ban – as they might unfold in the presence of mitigation strategies. We have adapted a model previously used to investigate FMD control policies in the UK to examine the potential for disease spread given an infection seeded in each county in Pennsylvania. The results are highly dependent upon the county of introduction and the spatial scale of transmission. Should the transmission kernel be identical to that for the UK, the epidemic impact is limited to fewer than 20 premises, regardless of the county of introduction. However, for wider kernels where infection can spread further, outbreaks seeded in or near the county with highest density of premises and animals result in large epidemics (>150 premises). Ring culling and vaccination reduce epidemic size, with the optimal radius of the rings being dependent upon the county of introduction. Should the kernel width exceed a given county-dependent threshold, ring culling is unable to control the epidemic. We find that a vaccinate-to-live policy is generally preferred to ring culling (in terms of reducing the overall number of premises culled), indicating that well-targeted control can dramatically reduce the risk of large scale outbreaks of foot-and-mouth disease occurring in Pennsylvania. PMID:22169708

  5. Genetic diversity and mutation of avian paramyxovirus serotype 1 (Newcastle disease virus) in wild birds and evidence for intercontinental spread

    USGS Publications Warehouse

    Ramey, Andy M.; Reeves, Andrew; Ogawa, Haruko; Ip, Hon S.; Imai, Kunitoshi; Bui, V. N.; Yamaguchi, Emi; Silko, N. Y.; Afonso, C.L.

    2013-01-01

    Avian paramyxovirus serotype 1 (APMV-1), or Newcastle disease virus, is the causative agent of Newcastle disease, one of the most economically important diseases for poultry production worldwide and a cause of periodic epizootics in wild birds in North America. In this study, we examined the genetic diversity of APMV-1 isolated from migratory birds sampled in Alaska, Japan, and Russia and assessed the evidence for intercontinental virus spread using phylogenetic methods. Additionally, we predicted viral virulence using deduced amino acid residues for the fusion protein cleavage site and estimated mutation rates for the fusion gene of class I and class II migratory bird isolates. All 73 isolates sequenced as part of this study were most closely related to virus genotypes previously reported for wild birds; however, five class II genotype I isolates formed a monophyletic clade exhibiting previously unreported genetic diversity, which met criteria for the designation of a new sub-genotype. Phylogenetic analysis of wild-bird isolates provided evidence for intercontinental virus spread, specifically viral lineages of APMV-1 class II genotype I sub-genotypes Ib and Ic. This result supports migratory bird movement as a possible mechanism for the redistribution of APMV-1. None of the predicted deduced amino acid motifs for the fusion protein cleavage site of APMV-1 strains isolated from migratory birds in Alaska, Japan, and Russia were consistent with those of previously identified virulent viruses. These data therefore provide no support for these strains contributing to the emergence of avian pathogens. The estimated mutation rates for fusion genes of class I and class II wild-bird isolates were faster than those reported previously for non-virulent APMV-1 strains. Collectively, these findings provide new insight into the diversity, spread, and evolution of APMV-1 in wild birds.

  6. Spread of disease with transport-related infection and entry screening.

    PubMed

    Liu, Xianning; Takeuchi, Yasuhiro

    2006-09-21

    An SIQS model is proposed to study the effect of transport-related infection and entry screening. If the basic reproduction number is below unity, the disease free equilibrium is locally asymptotically stable. There exists an endemic equilibrium which is locally asymptotically stable if the reproduction number is larger than unity. It is shown that the disease is endemic in the sense of permanence if and only if the endemic equilibrium exists. Entry screening is shown to be helpful for disease eradication since it can always have the possibility to eradicate the disease led by transport-related infection and furthermore have the possibility to eradicate disease even when the disease is endemic in both isolated cities. PMID:16678858

  7. An approach for de-identification of point locations of livestock premises for further use in disease spread modeling.

    PubMed

    Martin, Michael K; Helm, Julie; Patyk, Kelly A

    2015-06-15

    We describe a method for de-identifying point location data used for disease spread modeling to allow data custodians to share data with modeling experts without disclosing individual farm identities. The approach is implemented in an open-source software program that is described and evaluated here. The program allows a data custodian to select a level of de-identification based on the K-anonymity statistic. The program converts a file of true farm locations and attributes into a file appropriate for use in disease spread modeling with the locations randomly modified to prevent re-identification based on location. Important epidemiological relationships such as clustering are preserved to as much as possible to allow modeling similar to those using true identifiable data. The software implementation was verified by visual inspection and basic descriptive spatial analysis of the output. Performance is sufficient to allow de-identification of even large data sets on desktop computers available to any data custodian. PMID:25944175

  8. Occurrence of Stolbur Phytoplasma Disease in Spreading Type Petunia hybrida Cultivars in Korea.

    PubMed

    Chung, Bong Nam; Jeong, Myeong Il; Choi, Seung Kook; Joa, Jae Ho; Choi, Kyeong San; Choi, In Myeong

    2013-12-01

    In January 2012, spreading type petunia cv. Wave Pink plants showing an abnormal growth habit of sprouting unusual multiple plantlets from the lateral buds were collected from a greenhouse in Gwacheon, Gyeonggi Province, Korea. The presence of phytoplasma was investigated using PCR with the primer pairs P1/P6, and R16F1/R1 for nested-PCR. In the nested PCR, 1,096 bp PCR products were obtained, and through sequencing 12 Pet-Stol isolates were identified. Comparison of the nucleotide sequences of 16S rRNA gene of the 12 Pet-Stol isolates with other phytoplasmas belonging to aster yellows or Stolbur showed that Pet-Stol isolates were members of Stolbur. The presence of phytoplasma in petunia was also confirmed by microscopic observation of the pathogens. In this study, Stolbur phytoplasma was identified from spreading type petunia cultivars by sequence analysis of 16S rRNA gene of phytoplasma and microscopic observation of phytoplasma bodies. This is the first report of Stolbur phytoplasma in commercial Petunia hybrida cultivars. PMID:25288978

  9. Occurrence of Stolbur Phytoplasma Disease in Spreading Type Petunia hybrida Cultivars in Korea

    PubMed Central

    Chung, Bong Nam; Jeong, Myeong Il; Choi, Seung Kook; Joa, Jae Ho; Choi, Kyeong San; Choi, In Myeong

    2013-01-01

    In January 2012, spreading type petunia cv. Wave Pink plants showing an abnormal growth habit of sprouting unusual multiple plantlets from the lateral buds were collected from a greenhouse in Gwacheon, Gyeonggi Province, Korea. The presence of phytoplasma was investigated using PCR with the primer pairs P1/P6, and R16F1/R1 for nested-PCR. In the nested PCR, 1,096 bp PCR products were obtained, and through sequencing 12 Pet-Stol isolates were identified. Comparison of the nucleotide sequences of 16S rRNA gene of the 12 Pet-Stol isolates with other phytoplasmas belonging to aster yellows or Stolbur showed that Pet-Stol isolates were members of Stolbur. The presence of phytoplasma in petunia was also confirmed by microscopic observation of the pathogens. In this study, Stolbur phytoplasma was identified from spreading type petunia cultivars by sequence analysis of 16S rRNA gene of phytoplasma and microscopic observation of phytoplasma bodies. This is the first report of Stolbur phytoplasma in commercial Petunia hybrida cultivars. PMID:25288978

  10. Contagious agalactia of small ruminants: current knowledge concerning epidemiology, diagnosis and control.

    PubMed

    Bergonier, D; Berthelot, X; Poumarat, F

    1997-12-01

    Contagious agalactia of small ruminants is a syndrome which principally affects the mammary glands, joints and eyes. The main causal agents are Mycoplasma agalactiae in sheep, and M. agalactiae, M. mycoides subsp. mycoides large colony type and M. capricolum subsp. capricolum in goats. In addition, M. putrefaciens can produce a similar clinical picture, particularly in goats. Contagious agalactia occurs on all five continents and is often enzootic. The evolution of the infection tends to be chronic in affected animals and herds. Symptomless shedding of mycoplasmas, mainly in the milk, may persist for a long time. These insidious infections, associated with carriage in the ears of healthy animals, are difficult to diagnose and to control. The main mode of transmission between flocks is related to the sale of carrier animals and contact during transhumance, whereas transmission within a flock occurs through contact, suckling and milking. This review discusses the clinical features, epidemiology, treatment, prevention and control of the disease. PMID:9567311

  11. [The spread of ecology-dependent diseases of the genitourinary system in bioclimatic zones of the Primorski? region].

    PubMed

    Kiku, P F; Gorborukova, T V; Anan'ev, V Iu

    2013-01-01

    The estimation of the prevalence of a class of diseases of the genitourinary system (ICD-10) of the population in the bioclimatic zones of the Primorsky Krai, with taking into account the environmental situation has been performed. The study of the prevalence of diseases of the genitourinary system was carried out with the use of the classical method of data analysis--descriptive statistics. To determine the impact of water quality correlation and regression analysis of the statistical software package SPP has been applied. The study revealed that the diseases of the genitourinary system occupy in the structure of ecology-dependent morbidity in adults--14.9%, in adolescents--13.1% and in children--5.2%, respectively. During the period of 2000-2011 there is noted a trend of the growth of the level of pathology of the genitourinary system. Over the past 5 years, the number of uronefrological patients doubled. Using the a chi-square test for independence, we found that there is a statistically significant correlation (p < or = 0.001) between the level of diseases of the genitourinary system, the bio-climatic zones and zones of ecological situation in all age groups. The use of regression analysis (multiple regression equation) allowed to determine the main parameters of the water module affecting the rate of spread of diseases of the genitourinary system in different bioclimatic zones. The prevalence level of diseases of the genitourinary system in each age group and bioclimatic zone is affected by a certain combination of parameters of the chemical composition of drinking water. The priority of them are by microbial number, Cl-, Fe sum, NO3-, HCO3-, PH, Mg2+, Ca2+. Ranking of the territory in terms of morbidity permitted to determine the problematic situation in the administrative bodies that was taken into account in the development of the program on the prevention of the ecology-dependent diseases of the genitourinary system. PMID:24340921

  12. Landscape influences on dispersal of white-tailed deer and attendant risk of chronic wasting disease spread as assessed by a landscape genetics approach

    Microsoft Academic Search

    Krista Renee Lang

    2010-01-01

    Understanding factors that influence the spread of wildlife diseases is crucial for designing effective surveillance programs and appropriate management strategies. The potential introduction of chronic wasting disease (CWD) to Iowa is of significant management concern because it is found in free-ranging white-tailed deer (Odocoileus virginianus) populations in several bordering states, including Wisconsin. To address this concern, I used a landscape

  13. LETTER Parasite consumption and host interference can inhibit disease spread in dense populations

    E-print Network

    Hall, Spencer

    David J. Civitello,1 * Susan Pearsall,1,2 Meghan A. Duffy3,4 and Spencer R. Hall1 Abstract Disease- mission for hosts that consume their parasites, combining experiments, models and field data. Models

  14. Intercontinental spread of a genetically distinctive complex of clones of Neisseria meningitidis causing epidemic disease.

    PubMed

    Caugant, D A; Frřholm, L O; Břvre, K; Holten, E; Frasch, C E; Mocca, L F; Zollinger, W D; Selander, R K

    1986-07-01

    Strains of Neisseria meningitidis responsible for an epidemic of meningococcal disease occurring in Norway since the mid-1970s and for recent increases in the incidence of disease in several other parts of Europe have been identified by multilocus enzyme electrophoresis as members of a distinctive group of 22 closely related clones (the ET-5 complex). Clones of this complex have also colonized South Africa, Chile, Cuba, and Florida, where they have been identified as the causative agents of recent outbreaks of meningococcal disease. There is strong circumstantial evidence that outbreaks of disease occurring in Miami in 1981 and 1982 were caused in large part by bacteria that reached Florida via human immigrants from Cuba. PMID:3088568

  15. Model Hierarchies in Edge-Based Compartmental Modeling for Infectious Disease Spread

    PubMed Central

    Miller, Joel C.; Volz, Erik M.

    2012-01-01

    We consider the family of edge-based compartmental models for epidemic spread developed in [11]. These models allow for a range of complex behaviors, and in particular allow us to explicitly incorporate duration of a contact into our mathematical models. Our focus here is to identify conditions under which simpler models may be substituted for more detailed models, and in so doing we define a hierarchy of epidemic models. In particular we provide conditions under which it is appropriate to use the standard mass action SIR model, and we show what happens when these conditions fail. Using our hierarchy, we provide a procedure leading to the choice of the appropriate model for a given population. Our result about the convergence of models to the Mass Action model gives clear, rigorous conditions under which the Mass Action model is accurate. PMID:22911242

  16. Serogroup W meningococcal disease: global spread and current affect on the Southern Cone in Latin America.

    PubMed

    Abad, R; López, E L; Debbag, R; Vázquez, J A

    2014-12-01

    Meningococcal serogroup W strains have been emerging throughout the current century with most of the isolates belonging to the sequence type (ST11)/electrophoretic type (ET37) clonal complex (ST11/E37 CC), particularly since the international outbreak following Hajj 2000. That outbreak appears to have triggered off that trend, contributing to the spread of W ST11/ET37 CC strains globally; however, local strains could be also responsible for increases in the percentage and/or incidence rates of this serogroup in some countries. More recently, unexpected increases in the percentage and incidence rate of W has been noticed in different countries located in the South Cone in Latin America, and W ST11/ET37 CC strains now appear as endemic in the region and an extensive immunization programme with tetravalent conjugate vaccine (covering serogroups A, C, Y and W) has been recently implemented in Chile. It is difficult to ascertain whether we are observing the emergence of W ST11 CC strains in different geographical areas or whether the Hajj 2000 strain is still spreading globally. Several aspects of the evolution of that situation are analysed in this paper, reviewing also the implications in immunization programmes. Closely related with the analysis of this potential evolution, it will be very interesting to monitor the evolution of serogroup W in the African meningitis belt after implementation of the extensive immunization programme with serogroup A conjugate vaccine that is currently underway. More data about carriers, transmission, clonal lineages, etc. are needed for taking decisions (target groups, outbreak control, defining the extent, etc.) to adapt the response strategy with potential interventions with broad coverage vaccines against the emergent serogroup W. PMID:24831052

  17. The French Connection: The First Large Population-Based Contact Survey in France Relevant for the Spread of Infectious Diseases

    PubMed Central

    Béraud, Guillaume; Kazmercziak, Sabine; Beutels, Philippe; Levy-Bruhl, Daniel; Lenne, Xavier; Mielcarek, Nathalie; Yazdanpanah, Yazdan; Boëlle, Pierre-Yves; Hens, Niel; Dervaux, Benoit

    2015-01-01

    Background Empirical social contact patterns are essential to understand the spread of infectious diseases. To date, no such data existed for France. Although infectious diseases are frequently seasonal, the temporal variation of contact patterns has not been documented hitherto. Methods COMES-F is the first French large-scale population survey, carried out over 3 different periods (February-March, April, April-May) with some participants common to the first and the last period. Participants described their contacts for 2 consecutive days, and reported separately on professional contacts when typically over 20 per day. Results 2033 participants reported 38 881 contacts (weighted median [first quartile-third quartile]: 8[5–14] per day), and 54 378 contacts with supplementary professional contacts (9[5–17]). Contrary to age, gender, household size, holidays, weekend and occupation, period of the year had little influence on the number of contacts or the mixing patterns. Contact patterns were highly assortative with age, irrespective of the location of the contact, and gender, with women having 8% more contacts than men. Although most contacts occurred at home and at school, the inclusion of professional contacts modified the structure of the mixing patterns. Holidays and weekends reduced dramatically the number of contacts, and as proxies for school closure, reduced R0 by 33% and 28%, respectively. Thus, school closures could have an important impact on the spread of close contact infections in France. Conclusions Despite no clear evidence for temporal variation, trends suggest that more studies are needed. Age and gender were found important determinants of the mixing patterns. Gender differences in mixing patterns might help explain gender differences in the epidemiology of infectious diseases. PMID:26176549

  18. Effect of Bactericides on Population Sizes and Spread of Clavibacter michiganensis subsp. michiganensis on Tomatoes in the Greenhouse and on Disease Development and Crop Yield in the Field

    Microsoft Academic Search

    M. K. Hausbeck; J. Bell; C. Medina-Mora; R. Podolsky; D. W. Fulbright

    2000-01-01

    Hausbeck, M. K., Bell, J., Medina-Mora, C., Podolsky, R., and Fulbright, D. W. 2000. Effect of bactericides on population sizes and spread of Clavi- bacter michiganensis subsp. michiganensis on tomatoes in the greenhouse and on disease development and crop yield in the field. Phytopathology 90:38-44. Chemical applications, with the exception of mancozeb, reduced popu- lation sizes and spread of Clavibacter

  19. Infectious Disease and Climate Change: Is Climate Change Responsible for the Spread of West Nile Virus?

    NSDL National Science Digital Library

    2013-02-25

    Temperature increases associated with global climate change have led to concerns that infectious diseases common in warmer tropical and subtropical climates may become more common in warming middle altitudes. In this problem-based learning module, learners investigate the connections between disease and climate change. Additional resources and activities are also provided. This module was developed to be used in the Earth System Science Education Alliance (ESSEA) courses for middle and high school teachers and is also available to teachers to adapt for general classroom use.

  20. Personalized ventilation as a control measure for airborne transmissible disease spread

    PubMed Central

    Pantelic, Jovan; Sze-To, Gin Nam; Tham, Kwok Wai; Chao, Christopher Y. H.; Khoo, Yong Chuan Mike

    2009-01-01

    The protective role of personalized ventilation (PV) against plausible airborne transmissible disease was investigated using cough droplets released from a ‘coughing machine’ simulating the human cough at different distances (1, 1.75 and 3 m) from the PV user. Particle image velocimetry was used to characterize and visualize the interaction between the cough-generated multiphase flow and PV-induced flow in the inhalation zone of the thermal breathing manikin. A dose–response model for unsteady imperfectly mixed environment was used to estimate the reduction in infection risk of two common diseases that can be transmitted by airborne mode. PV was able to both reduce the peak aerosol concentration levels and shorten the exposure time at all the examined injection distances. PV could reduce the infection risks of two diseases, influenza A and tuberculosis, by between 27 and 65 per cent. The protection offered by PV is less effective at a distance of 1.75 m than the other distances, as shown in the risk assessment results, as the PV-generated flow was blown off by the cough-generated flow for the longest time. Results of this study demonstrate the ability of desktop PV to mitigate the infection risk of airborne transmissible disease. PMID:19812074

  1. Modelling the initial spread of foot-and-mouth disease through animal movements

    E-print Network

    Kiss, Istvan Zoltan

    . Kiss and R. R. Kao Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK of the industry for both cattle (Christley et al. 2005) and sheep (Kiss et al. in press) allow widespread dissemination of disease, and seasonal trading patterns result in large variation in epidemic risk (Kiss et al

  2. Efficient detection of contagious outbreaks in massive metropolitan encounter networks

    E-print Network

    Sun, Lijun

    Physical contact remains difficult to trace in large metropolitan networks, though it is a key vehicle for the transmission of contagious outbreaks. Co-presence encounters during daily transit use provide us with a city-scale ...

  3. MedyMyst: Orientation at O.R.B. Introduction to the six types of pathogens, Koch's Postulates, disease spread, disease prevention measures, and the immune system.

    NSDL National Science Digital Library

    Center for Technology in Teaching and Learning

    2011-09-28

    This is a problem-based learning adventure game that engages the player in the role of scientist, historian, and detective. Students get an introduction to infectious diseases and pathogens. At the beginning, the student is presented with a problem that must be solved. During the mission, students conduct field and laboratory investigations with the aid of the MedMyst characters. Each mission can be played within one class period (approximately 30 to 45 minutes) and the knowledge gained from each mission will help students understand how infectious diseases are spread. We recommend that Mission One be played first because it covers the basics and serves as an orientation to the concepts and the characters. However, any of the missions may be chosen to follow Mission One. Each mission is a self-contained problem and may be played without reliance on the other missions. Also available in Spanish.

  4. Long-Distance Travel Behaviours Accelerate and Aggravate the Large-Scale Spatial Spreading of Infectious Diseases

    PubMed Central

    Zu, Zhenghu; Zheng, Tao; Zhang, Wendou; Xu, Qing; Liu, Jinjie

    2014-01-01

    The study analyses the role of long-distance travel behaviours on the large-scale spatial spreading of directly transmitted infectious diseases, focusing on two different travel types in terms of the travellers travelling to a specific group or not. For this purpose, we have formulated and analysed a metapopulation model in which the individuals in each subpopulation are organised into a scale-free contact network. The long-distance travellers between the subpopulations will temporarily change the network structure of the destination subpopulation through the “merging effects (MEs),” which indicates that the travellers will be regarded as either connected components or isolated nodes in the contact network. The results show that the presence of the MEs has constantly accelerated the transmission of the diseases and aggravated the outbreaks compared to the scenario in which the diversity of the long-distance travel types is arbitrarily discarded. Sensitivity analyses show that these results are relatively constant regarding a wide range variation of several model parameters. Our study has highlighted several important causes which could significantly affect the spatiotemporal disease dynamics neglected by the present studies. PMID:24511324

  5. Contagious behavior: an alternative approach to mirror-like phenomena.

    PubMed

    Provine, Robert R

    2014-04-01

    Contagious behaviors such as yawning and itching/scratching have mirror-like properties and clearly defined stimulus and motor parameters; they are also relatively easy to study and should be part of the debate about mirror neurons and the neurological mechanisms of social behavior. The broadly tuned, multimodal stimuli of contagious behavior challenge present accounts of mirror mechanisms that focus on specific, mirrored acts. PMID:24775173

  6. Broad and fine-scale genetic analysis of white-tailed deer populations: estimating the relative risk of chronic wasting disease spread.

    PubMed

    Cullingham, Catherine I; Merrill, Evelyn H; Pybus, Margo J; Bollinger, Trent K; Wilson, Gregory A; Coltman, David W

    2011-01-01

    Chronic wasting disease is a transmissible spongiform encephalopathy of cervids, similar to sheep scrapie that has only recently been detected in wild populations of white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus hemionus) in western Canada. Relatively little is known about local transmission dynamics of the disease or the potential for long-distance spread. We analysed the population genetic structure of over 2000 white-tailed deer sampled from Alberta, British Columbia, and Saskatchewan using microsatellite profiles and mtDNA sequencing to assess the relative risk of disease spread. There was very little differentiation among subpopulations and a weak trend of increasing differentiation with geographic distance. This suggests that the potential for long-distance disease spread through the dispersal of infected individuals is possible, yet the risk of spread should gradually diminish with distance from infection foci. Within subpopulations, females were more related than expected by chance (R > 0) within a radius of approximately 500 m. Sex-biased philopatry and social interactions among related females may facilitate local disease transmission within social groups. Local herd reduction may therefore be an effective tool for reducing the disease prevalence when implemented at the appropriate spatial scale. PMID:25567957

  7. Smell facilitates auditory contagious yawning in stranger rats.

    PubMed

    Moyaho, Alejandro; Rivas-Zamudio, Xaman; Ugarte, Araceli; Eguibar, José R; Valencia, Jaime

    2015-01-01

    Most vertebrates yawn in situations ranging from relaxation to tension, but only humans and other primate species that show mental state attribution skills have been convincingly shown to display yawn contagion. Whether complex forms of empathy are necessary for yawn contagion to occur is still unclear. As empathy is a phylogenetically continuous trait, simple forms of empathy, such as emotional contagion, might be sufficient for non-primate species to show contagious yawning. In this study, we exposed pairs of male rats, which were selected for high yawning, with each other through a perforated wall and found that olfactory cues stimulated yawning, whereas visual cues inhibited it. Unexpectedly, cage-mate rats failed to show yawn contagion, although they did show correlated emotional reactivity. In contrast, stranger rats showed auditory contagious yawning and greater rates of smell-facilitated auditory contagious yawning, although they did not show correlated emotional reactivity. Strikingly, they did not show contagious yawning to rats from a low-yawning strain. These findings indicate that contagious yawning may be a widespread trait amongst vertebrates and that mechanisms other than empathy may be involved. We suggest that a communicatory function of yawning may be the mechanism responsible for yawn contagion in rats, as contagiousness was strain-specific and increased with olfactory cues, which are involved in mutual recognition. PMID:25156806

  8. Suboptimal Herd Performance Amplifies the Spread of Infectious Disease in the Cattle Industry

    PubMed Central

    Gates, M. Carolyn; Woolhouse, Mark E. J.

    2014-01-01

    Farms that purchase replacement breeding cattle are at increased risk of introducing many economically important diseases. The objectives of this analysis were to determine whether the total number of replacement breeding cattle purchased by individual farms could be reduced by improving herd performance and to quantify the effects of such reductions on the industry-level transmission dynamics of infectious cattle diseases. Detailed information on the performance and contact patterns of British cattle herds was extracted from the national cattle movement database as a case example. Approximately 69% of beef herds and 59% of dairy herds with an average of at least 20 recorded calvings per year purchased at least one replacement breeding animal. Results from zero-inflated negative binomial regression models revealed that herds with high average ages at first calving, prolonged calving intervals, abnormally high or low culling rates, and high calf mortality rates were generally more likely to be open herds and to purchase greater numbers of replacement breeding cattle. If all herds achieved the same level of performance as the top 20% of herds, the total number of replacement beef and dairy cattle purchased could be reduced by an estimated 34% and 51%, respectively. Although these purchases accounted for only 13% of between-herd contacts in the industry trade network, they were found to have a disproportionately strong influence on disease transmission dynamics. These findings suggest that targeting extension services at herds with suboptimal performance may be an effective strategy for controlling endemic cattle diseases while simultaneously improving industry productivity. PMID:24671129

  9. Suboptimal herd performance amplifies the spread of infectious disease in the cattle industry.

    PubMed

    Gates, M Carolyn; Woolhouse, Mark E J

    2014-01-01

    Farms that purchase replacement breeding cattle are at increased risk of introducing many economically important diseases. The objectives of this analysis were to determine whether the total number of replacement breeding cattle purchased by individual farms could be reduced by improving herd performance and to quantify the effects of such reductions on the industry-level transmission dynamics of infectious cattle diseases. Detailed information on the performance and contact patterns of British cattle herds was extracted from the national cattle movement database as a case example. Approximately 69% of beef herds and 59% of dairy herds with an average of at least 20 recorded calvings per year purchased at least one replacement breeding animal. Results from zero-inflated negative binomial regression models revealed that herds with high average ages at first calving, prolonged calving intervals, abnormally high or low culling rates, and high calf mortality rates were generally more likely to be open herds and to purchase greater numbers of replacement breeding cattle. If all herds achieved the same level of performance as the top 20% of herds, the total number of replacement beef and dairy cattle purchased could be reduced by an estimated 34% and 51%, respectively. Although these purchases accounted for only 13% of between-herd contacts in the industry trade network, they were found to have a disproportionately strong influence on disease transmission dynamics. These findings suggest that targeting extension services at herds with suboptimal performance may be an effective strategy for controlling endemic cattle diseases while simultaneously improving industry productivity. PMID:24671129

  10. Molecular epidemiology of contagious bovine pleuropneumonia by multilocus sequence analysis of Mycoplasma mycoides subspecies mycoides biotype SC strains

    Microsoft Academic Search

    S Lorenzon; I Arzul; A Peyraud; P Hendrikx; F Thiaucourt

    2003-01-01

    Contagious bovine pleuropneumonia is a bacterial disease caused by Mycoplasma mycoides subsp. mycoides SC (MmmSC), and included in list A of the Office International des Epizooties. It is one of the major constraints to cattle raising in sub-Saharan and south-western Africa and also a threat to all countries currently free of the disease. MmmSC strains were considered very homogeneous until

  11. Contagious Yawning and Seasonal Climate Variation

    PubMed Central

    Gallup, Andrew C.; Eldakar, Omar Tonsi

    2011-01-01

    Recent evidence suggests that yawning is a thermoregulatory behavior. To explore this possibility further, the frequency of contagious yawning in humans was measured while outdoors in a desert climate in the United States during two distinct temperature ranges and seasons (winter: 22°C; early summer: 37°C). As predicted, the proportion of pedestrians who yawned in response to seeing pictures of people yawning differed significantly between the two conditions (winter: 45%; summer: 24%). Across conditions yawning occurred at lower ambient temperatures, and the tendency to yawn during each season was associated with the length of time spent outside prior to being tested. Participants were more likely to yawn in the milder climate after spending long periods of time outside, while prolonged exposure to ambient temperatures at or above body temperature was associated with reduced yawning. This is the first report to show that the incidence of yawning in humans is associated with seasonal climate variation, further demonstrating that yawn-induced contagion effects can be mediated by factors unrelated to individual social characteristics or cognitive development. PMID:21960970

  12. Contagious yawning and seasonal climate variation.

    PubMed

    Gallup, Andrew C; Eldakar, Omar Tonsi

    2011-01-01

    Recent evidence suggests that yawning is a thermoregulatory behavior. To explore this possibility further, the frequency of contagious yawning in humans was measured while outdoors in a desert climate in the United States during two distinct temperature ranges and seasons (winter: 22°C; early summer: 37°C). As predicted, the proportion of pedestrians who yawned in response to seeing pictures of people yawning differed significantly between the two conditions (winter: 45%; summer: 24%). Across conditions yawning occurred at lower ambient temperatures, and the tendency to yawn during each season was associated with the length of time spent outside prior to being tested. Participants were more likely to yawn in the milder climate after spending long periods of time outside, while prolonged exposure to ambient temperatures at or above body temperature was associated with reduced yawning. This is the first report to show that the incidence of yawning in humans is associated with seasonal climate variation, further demonstrating that yawn-induced contagion effects can be mediated by factors unrelated to individual social characteristics or cognitive development. PMID:21960970

  13. [Hypotheses on the role of the prehistoric Sahara in the spread of parasitic and hematologic diseases].

    PubMed

    Nozais, J P

    1987-01-01

    15,000 years ago, the Sahara was moist, inhabited by tropical fauna and travelled over by nomadic populations. Later, the dryness incited human migrations to North or West Africa. African bilharziasis (S. mansoni and S. haematobium) could have been carried by nomadic populations infected in the Nile River. Sickle cell disease and alpha-thalassemia are derived from Saudi Arabia (unless in the case of alpha-thalassemia there was an identical mutation in several regions). Echinococcosis was brought with the dromedary in the ptolemaic era whereas ankylostomiasis was brought by the Romans or the Arabs. PMID:3301031

  14. [Health Communication: Preventing the Spread of Ebola Virus Disease in the Portuguese Spoken African Countries - Methodology KISS & KEYWORDS].

    PubMed

    De Santiago, Isabel; Miguel, José Pereira; Antunes, Francisco

    2015-01-01

    In this work, Health Communication is considered as an important discipline in medicine and health sciences for his role as true determinant of health. We highlight their contribution to health promotion and disease prevention. Thus, the Health Communication Plan (PCS): Preventing the spread of Ebola virus disease in the Portuguese Speaking African Countries - KISS & KEYWORDS methodology is a tool that aims to minimize the risk of infection by Ebola virus in the Portuguese Speaking African Countries and also train for a general improvement of health conditions of the local populations. In the PCS design are especially considered the social and cultural contexts of the target populations, especially the customs, traditions and religion. Health Communication is considered as an Essential Function of Public Health and its main is to provide a population-based approach. The target of communication actions are population groups in addition to the individual communication, target-audiences are people without access to the media, in Guinea Bissau, Cape Verde and Sao Tome and Principe. Under the communication plan uses the methodology, models and practices both by media professionals as health. A proximity approach and cultural mediation, previously identified key facts, are defined objectives; outlines to the Plan in concrete and its implementation methodology (target-audience and following intervention, materials to be used and key-messages and partners to mobilize) following the World Health Organisation standards. PMID:26061502

  15. Using friends as sensors to detect global-scale contagious outbreaks.

    PubMed

    Garcia-Herranz, Manuel; Moro, Esteban; Cebrian, Manuel; Christakis, Nicholas A; Fowler, James H

    2014-01-01

    Recent research has focused on the monitoring of global-scale online data for improved detection of epidemics, mood patterns, movements in the stock market political revolutions, box-office revenues, consumer behaviour and many other important phenomena. However, privacy considerations and the sheer scale of data available online are quickly making global monitoring infeasible, and existing methods do not take full advantage of local network structure to identify key nodes for monitoring. Here, we develop a model of the contagious spread of information in a global-scale, publicly-articulated social network and show that a simple method can yield not just early detection, but advance warning of contagious outbreaks. In this method, we randomly choose a small fraction of nodes in the network and then we randomly choose a friend of each node to include in a group for local monitoring. Using six months of data from most of the full Twittersphere, we show that this friend group is more central in the network and it helps us to detect viral outbreaks of the use of novel hashtags about 7 days earlier than we could with an equal-sized randomly chosen group. Moreover, the method actually works better than expected due to network structure alone because highly central actors are both more active and exhibit increased diversity in the information they transmit to others. These results suggest that local monitoring is not just more efficient, but also more effective, and it may be applied to monitor contagious processes in global-scale networks. PMID:24718030

  16. Using Friends as Sensors to Detect Global-Scale Contagious Outbreaks

    PubMed Central

    Garcia-Herranz, Manuel; Moro, Esteban; Cebrian, Manuel; Christakis, Nicholas A.; Fowler, James H.

    2014-01-01

    Recent research has focused on the monitoring of global–scale online data for improved detection of epidemics, mood patterns, movements in the stock market political revolutions, box-office revenues, consumer behaviour and many other important phenomena. However, privacy considerations and the sheer scale of data available online are quickly making global monitoring infeasible, and existing methods do not take full advantage of local network structure to identify key nodes for monitoring. Here, we develop a model of the contagious spread of information in a global-scale, publicly-articulated social network and show that a simple method can yield not just early detection, but advance warning of contagious outbreaks. In this method, we randomly choose a small fraction of nodes in the network and then we randomly choose a friend of each node to include in a group for local monitoring. Using six months of data from most of the full Twittersphere, we show that this friend group is more central in the network and it helps us to detect viral outbreaks of the use of novel hashtags about 7 days earlier than we could with an equal-sized randomly chosen group. Moreover, the method actually works better than expected due to network structure alone because highly central actors are both more active and exhibit increased diversity in the information they transmit to others. These results suggest that local monitoring is not just more efficient, but also more effective, and it may be applied to monitor contagious processes in global–scale networks. PMID:24718030

  17. Emerging infectious diseases and pandemic potential: status quo and reducing risk of global spread.

    PubMed

    McCloskey, Brian; Dar, Osman; Zumla, Alimuddin; Heymann, David L

    2014-10-01

    Emerging infectious diseases are an important public health threat and infections with pandemic potential are a major global risk. Although much has been learned from previous events the evidence for mitigating actions is not definitive and pandemic preparedness remains a political and scientific challenge. A need exists to develop trust and effective meaningful collaboration between countries to help with rapid detection of potential pandemic infections and initiate public health actions. This collaboration should be within the framework of the International Health Regulations. Collaboration between countries should be encouraged in a way that acknowledges the benefits that derive from sharing biological material and establishing equitable collaborative research partnerships. The focus of pandemic preparedness should include upstream prevention through better collaboration between human and animal health sciences to enhance capacity to identify potential pathogens before they become serious human threats, and to prevent their emergence where possible. The one-health approach provides a means to develop this and could potentially enhance alignment of global health and trade priorities. PMID:25189351

  18. Monitoring the spread of rabbit hemorrhagic disease virus as a new biological agent for control of wild European rabbits in Australia.

    PubMed

    Kovaliski, J

    1998-07-01

    Following the escape to the mainland of the rabbit hemorrhagic disease virus (RHDV) from Wardang Island off the coast of South Australia, a monitoring program was implemented over a 13 mo period, between October 1995 and October 1996 to determine the activity and rate of spread of the disease in the wild European rabbit (Oryctolagus cuniculus) population. All reports of dead rabbits were investigated. Whenever possible, liver and spleen tissue samples were collected from fresh carcasses and subsequently analysed for the presence of RHDV. Maximum rates of spread of rabbit hemorrhagic disease (RHD) in Australia ranged from 9 km/mo during summer to 414 km/mo in spring. New cases of RHD were moderate during late autumn and winter and peaked in spring. In summer the disease was rarely reported. PMID:9706550

  19. On the Origin and Spread of the Scab Disease of Apple: Out of Central Asia

    PubMed Central

    Gladieux, Pierre; Zhang, Xiu-Guo; Afoufa-Bastien, Damien; Valdebenito Sanhueza, Rosa-Maria; Sbaghi, Mohamed; Le Cam, Bruno

    2008-01-01

    Background Venturia inaequalis is an ascomycete fungus responsible for apple scab, a disease that has invaded almost all apple growing regions worldwide, with the corresponding adverse effects on apple production. Monitoring and predicting the effectiveness of intervention strategies require knowledge of the origin, introduction pathways, and population biology of pathogen populations. Analysis of the variation of genetic markers using the inferential framework of population genetics offers the potential to retrieve this information. Methodology/Principal Findings Here, we present a population genetic analysis of microsatellite variation in 1,273 strains of V. inaequalis representing 28 orchard samples from seven regions in five continents. Analysis of molecular variance revealed that most of the variation (88%) was distributed within localities, which is consistent with extensive historical migrations of the fungus among and within regions. Despite this shallow population structure, clustering analyses partitioned the data set into separate groups corresponding roughly to geography, indicating that each region hosts a distinct population of the fungus. Comparison of the levels of variability among populations, along with coalescent analyses of migration models and estimates of genetic distances, was consistent with a scenario in which the fungus emerged in Central Asia, where apple was domesticated, before its introduction into Europe and, more recently, into other continents with the expansion of apple growing. Across the novel range, levels of variability pointed to multiple introductions and all populations displayed signatures of significant post-introduction increases in population size. Most populations exhibited high genotypic diversity and random association of alleles across loci, indicating recombination both in native and introduced areas. Conclusions/Significance Venturia inaequalis is a model of invasive phytopathogenic fungus that has now reached the ultimate stage of the invasion process with a broad geographic distribution and well-established populations displaying high genetic variability, regular sexual reproduction, and demographic expansion. PMID:18197265

  20. A Recently Evolved Sublineage of the Mycobacterium tuberculosis Beijing Strain Family Is Associated with an Increased Ability to Spread and Cause Disease

    Microsoft Academic Search

    M. Hanekom; G. D. van der Spuy; E. Streicher; S. L. Ndabambi; C. R. E. McEvoy; M. Kidd; N. Beyers; T. C. Victor; P. D. van Helden; R. M. Warren

    2007-01-01

    This study aimed to reconstruct the evolutionary history of Beijing strains of Mycobacterium tuberculosis and to test the hypothesis that evolution has influenced the ability of the Beijing strains within the different Beijing sublineages to spread and cause disease. A PCR-based method was used to analyze the genome structure of 40 different loci in 325 Beijing isolates collected from new

  1. Optimizing hybrid spreading in metapopulations.

    PubMed

    Zhang, Changwang; Zhou, Shi; Miller, Joel C; Cox, Ingemar J; Chain, Benjamin M

    2015-01-01

    Epidemic spreading phenomena are ubiquitous in nature and society. Examples include the spreading of diseases, information, and computer viruses. Epidemics can spread by local spreading, where infected nodes can only infect a limited set of direct target nodes and global spreading, where an infected node can infect every other node. In reality, many epidemics spread using a hybrid mixture of both types of spreading. In this study we develop a theoretical framework for studying hybrid epidemics, and examine the optimum balance between spreading mechanisms in terms of achieving the maximum outbreak size. We show the existence of critically hybrid epidemics where neither spreading mechanism alone can cause a noticeable spread but a combination of the two spreading mechanisms would produce an enormous outbreak. Our results provide new strategies for maximising beneficial epidemics and estimating the worst outcome of damaging hybrid epidemics. PMID:25923411

  2. Absence of contagious yawning in children with autism spectrum disorder.

    PubMed

    Senju, Atsushi; Maeda, Makiko; Kikuchi, Yukiko; Hasegawa, Toshikazu; Tojo, Yoshikuni; Osanai, Hiroo

    2007-12-22

    This study is the first to report the disturbance of contagious yawning in individuals with autism spectrum disorder (ASD). Twenty-four children with ASD as well as 25 age-matched typically developing (TD) children observed video clips of either yawning or control mouth movements. Yawning video clips elicited more yawns in TD children than in children with ASD, but the frequency of yawns did not differ between groups when they observed control video clips. Moreover, TD children yawned more during or after the yawn video clips than the control video clips, but the type of video clips did not affect the amount of yawning in children with ASD. Current results suggest that contagious yawning is impaired in ASD, which may relate to their impairment in empathy. It supports the claim that contagious yawning is based on the capacity for empathy. PMID:17698452

  3. Contagious caprine pleuropneumonia outbreak in captive wild ungulates at Al Wabra Wildlife Preservation, State of Qatar.

    PubMed

    Arif, Abdi; Schulz, Julia; Thiaucourt, François; Taha, Abid; Hammer, Sven

    2007-03-01

    Contagious caprine pleuropneumonia (CCPP) caused by Mycoplasma capricolum subsp. capripneumoniae is a highly contagious and serious respiratory disease of domestic goats, characterized by coughing, severe respiratory distress, and high mortality rates. The lesions at necropsy are mainly a fibrinous pleuropneumonia with increased straw-colored pleural fluid. An outbreak of CCPP in wild goat (Capra aegagrus), Nubian ibex (Capra ibex nubiana), Laristan mouflon (Ovis orientalis laristanica), and gerenuk (Litocranius walleri) occurred at Al Wabra Wildlife Preservation in the State of Qatar. The disease was suspected because of the clinical symptoms and the necropsy findings and was confirmed by the isolation and identification of the causative organism. This new finding indicates that CCPP should be considered a potential threat to wildlife and the conservation of endangered ruminant species, especially in the Middle East, where it is enzootic because of its presence in chronic carriers. Susceptible imported animals should be quarantined and vaccinated. The preferred samples for diagnosis are the pleural fluid, which contains high numbers of Mycoplasma, and sections of hepatized lung, preferably at the interface of normal and diseased tissues. Samples must be shipped to diagnostic laboratories rapidly, and appropriate cool conditions must be maintained during shipping. PMID:17469281

  4. Brief Report: Does Eye Contact Induce Contagious Yawning in Children with Autism Spectrum Disorder?

    ERIC Educational Resources Information Center

    Senju, Atsushi; Kikuchi, Yukiko; Akechi, Hironori; Hasegawa, Toshikazu; Tojo, Yoshikuni; Osanai, Hiroo

    2009-01-01

    Individuals with autism spectrum disorder (ASD) reportedly fail to show contagious yawning, but the mechanism underlying the lack of contagious yawning is still unclear. The current study examined whether instructed fixation on the eyes modulates contagious yawning in ASD. Thirty-one children with ASD, as well as 31 age-matched typically…

  5. Contagious yawning: the role of self-awareness and mental state attribution

    Microsoft Academic Search

    Steven M Platek; Samuel R Critton; Thomas E Myers; Gordon G Gallup

    2003-01-01

    Contagious yawning is a common, but poorly understood phenomenon. We hypothesized that contagious yawning is part of a more general phenomenon known as mental state attribution (i.e. the ability to inferentially model the mental states of others). To test this hypothesis we compared susceptibility to contagiously yawn with performance on a self-face recognition task, several theory of mind stories, and

  6. Yawn, Yawn, Yawn, Yawn; Yawn, Yawn, Yawn! The Social, Evolutionary and Neuroscientific Facets of Contagious Yawning

    Microsoft Academic Search

    Steven M. Platek

    2010-01-01

    Contagious yawning is a common phenomenon affecting upwards of 60% of healthy humans. It has also been observed, at a lesser rate, in great apes and other primates. Here I summarize the suggestion that contagious yawning is a primitive expression of social cognition, namely empathy. Susceptibility to contagious yawning is correlated with the speed in recognizing one’s own face, theory

  7. Mycoplasma agalactiae, an Etiological Agent of Contagious Agalactia in Small Ruminants: A Review.

    PubMed

    Kumar, Amit; Rahal, Anu; Chakraborty, Sandip; Verma, Amit Kumar; Dhama, Kuldeep

    2014-01-01

    Mycoplasma agalactiae is one of the causal agents of classical contagious agalactia (CA), a serious, economically important but neglected enzootic disease of small ruminants. It occurs in many parts of the world and most notably in the Mediterranean Basin. Following the infection common complications are septicaemia, mastitis, arthritis, pleurisy, pneumonia, and keratoconjunctivitis. Primary or tentative diagnosis of the organism is based upon clinical signs. Various serological tests, namely, growth precipitation, immunofluorescence, complement fixation test, haemagglutination inhibition, agglutination, immunodiffusion, enzyme immunoassays, immunoelectrophoresis, blotting techniques, and others, are available. Molecular tools seem to be much more sensitive, specific, and faster and help to differentiate various strains. The real-time PCR, multiplex PCR, quantitative PCR, PCR-RFLP, MLST, and gene probes, complementary to segments of chromosomal DNA or 16S ribosomal RNA (rRNA), have strengthened the diagnosis of M. agalactiae. Both live attenuated and adjuvant (alum precipitated or saponified) inactivated vaccines are available with greater use of inactivated ones due to lack of side effects. The present review discusses the etiology, epidemiology, pathogenesis, and clinical signs of contagious agalactia in small ruminants along with trends and advances in its diagnosis, treatment, vaccination, prevention, and control strategies that will help in countering this disease. PMID:25097796

  8. Methodological Problems in the Study of Contagious Yawning

    Microsoft Academic Search

    Matthew W. Campbell; Frans B. M. de Waal

    2010-01-01

    The recent interest in contagious yawning has raised several challenges as the varied methods of testing have left some unresolved issues. We do not know how differences in key variables affect the observed rates of yawning, and we highlight these as being in need of direct testing. Different researchers analyze their results differently, and we make some recommendations for more

  9. Absence of contagious yawning in children with autism spectrum disorder

    Microsoft Academic Search

    Atsushi Senju; Makiko Maeda; Yukiko Kikuchi; Toshikazu Hasegawa; Yoshikuni Tojo; Hiroo Osanai

    2007-01-01

    Summary This study is the first to report the disturbance of contagious yawning in individuals with autism spectrum disorder (ASD). Twenty-four children with ASD, as well as 25 age- matched typically developing (TD) children, observed video clips of either yawning or control mouth movements. Yawning video clips elicited more yawns in TD children than in children with ASD, but the

  10. Yearning to yawn: the neural basis of contagious yawning

    Microsoft Academic Search

    Martin Schürmann; Maike D. Hesse; Klaas E. Stephan; Miiamaaria Saarela; Karl Zilles; Riitta Hari; Gereon R. Fink

    2005-01-01

    Yawning is contagious: Watching another person yawn may trigger us to do the same. Here we studied brain activation with functional magnetic resonance imaging (fMRI) while subjects watched videotaped yawns. Significant increases in the blood oxygen level dependent (BOLD) signal, specific to yawn viewing as contrasted to viewing non-nameable mouth movements, were observed in the right posterior superior temporal sulcus

  11. Contagious ecthyma in mountain goat of coastal British Columbia.

    PubMed

    Hebert, D M; Samuel, W M; Smith, G W

    1977-04-01

    Contagious ecthyma has been reported previously from mountain goat (Oreamnos americanus) in one restricted area of eastern British Columbia. A second focus of infection is reported for mountain goat from western British Columbia. Diagnosis was based on appearance of lesions at necropsy, histopathology and demonstration of poxvirus with the electron microscope. The epizootiology of this infection in mountain goat is discussed briefly. PMID:559107

  12. The Spread of a Pathogenic and an Apathogenic Strain of Newcastle Disease Virus in the Chick Embryo as Depending on the Protease Sensitivity of the Virus Glycoproteins

    Microsoft Academic Search

    Y. Nagai; K. Shimokata; T. Yoshida; M. Hamaguchi; M. Iinuma; K. Maeno; T. Matsumoto; H.-D. Klenk; R. Rott

    1979-01-01

    SUMMARY The pathogenic strain Italien and the apathogenic strain Ulster of Newcastle disease virus have been compared with respect to organ tropism and spread of infection in I I-day-old chick embryos. After infection of the endodermal layer of the chorioallantoic membrane by intra-allantoic inoculation with strain Italien, high virus titres are found in all extra-embryonic membranes and fluids and in

  13. Modelling spread of foot-and-mouth disease in wild white-tailed deer and feral pig populations using a geographic-automata model and animal distributions

    Microsoft Academic Search

    Michael P. Ward; Shawn W. Laffan; Linda D. Highfield

    2009-01-01

    We investigated how the size and distribution of wild deer and feral pigs – species that might act as potential foot-and-mouth disease (FMD) virus maintenance hosts – might affect the persistence and spread of FMD. We used a susceptible-latent-infected-recovered geographic-automata model and spatially referenced data from southern Texas, USA. Within this study area, 100 locations were randomly selected and FMD

  14. Rho-ROCK and Rac-PAK signaling pathways have opposing effects on the cell-to-cell spread of Marek's Disease Virus.

    PubMed

    Richerioux, Nicolas; Blondeau, Caroline; Wiedemann, Agnčs; Rémy, Sylvie; Vautherot, Jean-François; Denesvre, Caroline

    2012-01-01

    Marek's Disease Virus (MDV) is an avian alpha-herpesvirus that only spreads from cell-to-cell in cell culture. While its cell-to-cell spread has been shown to be dependent on actin filament dynamics, the mechanisms regulating this spread remain largely unknown. Using a recombinant BAC20 virus expressing an EGFPVP22 tegument protein, we found that the actin cytoskeleton arrangements and cell-cell contacts differ in the center and periphery of MDV infection plaques, with cells in the latter areas showing stress fibers and rare cellular projections. Using specific inhibitors and activators, we determined that Rho-ROCK pathway, known to regulate stress fiber formation, and Rac-PAK, known to promote lamellipodia formation and destabilize stress fibers, had strong contrasting effects on MDV cell-to-cell spread in primary chicken embryo skin cells (CESCs). Inhibition of Rho and its ROCKs effectors led to reduced plaque sizes whereas inhibition of Rac or its group I-PAKs effectors had the adverse effect. Importantly, we observed that the shape of MDV plaques is related to the semi-ordered arrangement of the elongated cells, at the monolayer level in the vicinity of the plaques. Inhibition of Rho-ROCK signaling also resulted in a perturbation of the cell arrangement and a rounding of plaques. These opposing effects of Rho and Rac pathways in MDV cell-to-cell spread were validated for two parental MDV recombinant viruses with different ex vivo spread efficiencies. Finally, we demonstrated that Rho/Rac pathways have opposing effects on the accumulation of N-cadherin at cell-cell contact regions between CESCs, and defined these contacts as adherens junctions. Considering the importance of adherens junctions in HSV-1 cell-to-cell spread in some cell types, this result makes of adherens junctions maintenance one potential and attractive hypothesis to explain the Rho/Rac effects on MDV cell-to-cell spread. Our study provides the first evidence that MDV cell-to-cell spread is regulated by Rho/Rac signaling. PMID:22952878

  15. Emergence of West Nile Virus Lineage 2 in Europe: A Review on the Introduction and Spread of a Mosquito-Borne Disease

    PubMed Central

    Hernández-Triana, Luis M.; Jeffries, Claire L.; Mansfield, Karen L.; Carnell, George; Fooks, Anthony R.; Johnson, Nicholas

    2014-01-01

    West Nile virus (WNV) is transmitted by mosquitoes and causes fever and encephalitis in humans, equines, and occasionally wild birds. The virus was first isolated in sub-Saharan Africa where it is endemic. WNV lineage 1 has been responsible for repeated disease outbreaks in the countries of the Mediterranean basin over the past 50?years. This lineage was also introduced into North America in 1999 causing widespread human, equine, and avian mortality. WNV lineage 2, the first WNV lineage to be isolated, was believed to be restricted to sub-Saharan Africa causing a relatively mild fever in humans. However, in 2004, an investigation in Hungary of a case of encephalitis in a wild goshawk (Accipiter gentiles) resulted in the isolation of WNV lineage 2. During the summer of 2004, and in subsequent years, the virus appeared to spread locally throughout Hungary and into neighboring Austria. Subsequently, WNV lineage 2 emerged in Greece in 2010 and in Italy in 2011, involving outbreaks on the Italian mainland and Sardinia. Further spread through the Balkan countries is also suspected. Whole genome sequencing has confirmed that the virus responsible for the outbreaks in Greece and Italy was almost identical to that isolated in Hungary. However, unlike the outbreaks in Hungary, the burden of disease in Mediterranean countries has fallen upon the human population with numerous cases of West Nile fever and a relatively higher mortality rate than in previous outbreaks. The emergence of WNV lineage 2 in Europe, its over-wintering and subsequent spread over large distances illustrates the repeated threat of emerging mosquito-borne diseases. This article will review the emergence of WNV lineage 2 in Europe; consider the pathways for virus spread and the public health implications for the continent. PMID:25538937

  16. Presence of contagious yawning in children with autism spectrum disorder.

    PubMed

    Usui, Saori; Senju, Atsushi; Kikuchi, Yukiko; Akechi, Hironori; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

    2013-01-01

    Most previous studies suggest diminished susceptibility to contagious yawning in children with autism spectrum disorder (ASD). However, it could be driven by their atypical attention to the face. To test this hypothesis, children with ASD and typically developing (TD) children were shown yawning and control movies. To ensure participants' attention to the face, an eye tracker controlled the onset of the yawning and control stimuli. Results demonstrated that both TD children and children with ASD yawned more frequently when they watched the yawning stimuli than the control stimuli. It is suggested therefore that the absence of contagious yawning in children with ASD, as reported in previous studies, might relate to their weaker tendency to spontaneously attend to others' faces. PMID:23970970

  17. Presence of Contagious Yawning in Children with Autism Spectrum Disorder

    PubMed Central

    Kikuchi, Yukiko; Akechi, Hironori; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

    2013-01-01

    Most previous studies suggest diminished susceptibility to contagious yawning in children with autism spectrum disorder (ASD). However, it could be driven by their atypical attention to the face. To test this hypothesis, children with ASD and typically developing (TD) children were shown yawning and control movies. To ensure participants' attention to the face, an eye tracker controlled the onset of the yawning and control stimuli. Results demonstrated that both TD children and children with ASD yawned more frequently when they watched the yawning stimuli than the control stimuli. It is suggested therefore that the absence of contagious yawning in children with ASD, as reported in previous studies, might relate to their weaker tendency to spontaneously attend to others' faces. PMID:23970970

  18. Methodological problems in the study of contagious yawning.

    PubMed

    Campbell, Matthew W; de Waal, Frans B M

    2010-01-01

    The recent interest in contagious yawning has raised several challenges as the varied methods of testing have left some unresolved issues. We do not know how differences in key variables affect the observed rates of yawning, and we highlight these as being in need of direct testing. Different researchers analyze their results differently, and we make some recommendations for more rigorous, thorough and informative analyses. Ultimately, problems arise when authors compare studies that used different methods and different analyses without acknowledging how these differences may have affected the results. In these cases, authors make inappropriate comparisons, which lead to conclusions that add confusion to the literature. Our goal in raising awareness of these issues is to generate new experiments and improve the discussion of existing research. With its link to empathy, a more standardized study of contagious yawning may be a useful tool for a variety of disciplines. PMID:20357470

  19. [Contagious agalactia of small ruminants: epidemiology, diagnosis and control].

    PubMed

    Bergonier, D; Poumarat, F

    1996-12-01

    Contagious agalactia of small ruminants is a syndrome which affects mainly the mammary glands, joints and eyes. The principal causal agents are Mycoplasma agalactiae in sheep and M. agalactiae, M. mycoides subsp. mycoides large colony type and M. capricolum subsp. capricolum in goats. In addition, M. putrefaciens can produce a similar clinical picture, particularly in goats. Contagious agalactia occurs on all five continents and is often enzootic. These infections are chronic in animals and in flocks. Symptomless shedding of mycoplasmas, mainly in the milk, may persist for a long time. Associated with carriage in the ears of healthy animals, these insidious infections are difficult to diagnose and control. The sale of carrier animals and contact during transhumance are the main modes of transmission between flocks, while transmission within a flock occurs through contact, suckling and milking. This review discusses clinical features, epidemiology, treatment, prevention and control. PMID:9527414

  20. Yearning to yawn: the neural basis of contagious yawning.

    PubMed

    Schürmann, Martin; Hesse, Maike D; Stephan, Klaas E; Saarela, Miiamaaria; Zilles, Karl; Hari, Riitta; Fink, Gereon R

    2005-02-15

    Yawning is contagious: Watching another person yawn may trigger us to do the same. Here we studied brain activation with functional magnetic resonance imaging (fMRI) while subjects watched videotaped yawns. Significant increases in the blood oxygen level dependent (BOLD) signal, specific to yawn viewing as contrasted to viewing non-nameable mouth movements, were observed in the right posterior superior temporal sulcus (STS) and bilaterally in the anterior STS, in agreement with the high affinity of STS to social cues. However, no additional yawn-specific activation was observed in Broca's area, the core region of the human mirror-neuron system (MNS) that matches action observation and execution. Thus, activation associated with viewing another person yawn seems to circumvent the essential parts of the MNS, in line with the nature of contagious yawns as automatically released behavioural acts-rather than truly imitated motor patterns that would require detailed action understanding. The subjects' self-reported tendency to yawn covaried negatively with activation of the left periamygdalar region, suggesting a connection between yawn contagiousness and amygdalar activation. PMID:15670705

  1. 9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...of disease; ascertainment of value and compensation. 71.14...disease; ascertainment of value and compensation. When...is authorized by law and an appropriation is available therefor, the value of the animals,...

  2. 9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...of disease; ascertainment of value and compensation. 71.14...disease; ascertainment of value and compensation. When...is authorized by law and an appropriation is available therefor, the value of the animals,...

  3. 9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...of disease; ascertainment of value and compensation. 71.14...disease; ascertainment of value and compensation. When...is authorized by law and an appropriation is available therefor, the value of the animals,...

  4. 9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...of disease; ascertainment of value and compensation. 71.14...disease; ascertainment of value and compensation. When...is authorized by law and an appropriation is available therefor, the value of the animals,...

  5. Bayesian Biosurveillance of Disease Outbreaks Gregory F. Cooper

    E-print Network

    Wong, Weng-Keen

    Bayesian networks to model spatio-temporal patterns of a non-contagious disease (respiratory anthrax) or bioterrorist- induced (e.g., anthrax and smallpox), is a critically important problem today. We need to detect of people. We concentrate on modeling non-contagious outbreak diseases, such as airborne anthrax or West

  6. Recombinant Newcastle disease vaccines: risk for recombination, reversion to virulence, and spread in non-target species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Newcastle disease (ND), caused by Newcastle disease virus (NDV), is one of the most important diseases of poultry and causes significant economic losses to the poultry industry worldwide. Vaccination is the main form of control of ND and it has been practiced for more than 60 years with billions of...

  7. Genetic diversity and mutation of avian paramyxovirus serotype 1 (Newcastle disease virus) in wild birds and evidence for intercontinental spread

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian paramyxovirus serotype 1 (APMV-1), or Newcastle disease virus, is the causative agent of Newcastle disease (ND), one of the most economically important diseases for poultry production worldwide and a cause of periodic epornitics in wild birds in North America. In this study, we explored the ge...

  8. Ebola virus disease 2013-2014 outbreak in west Africa: an analysis of the epidemic spread and response.

    PubMed

    Cenciarelli, Orlando; Pietropaoli, Stefano; Malizia, Andrea; Carestia, Mariachiara; D'Amico, Fabrizio; Sassolini, Alessandro; Di Giovanni, Daniele; Rea, Silvia; Gabbarini, Valentina; Tamburrini, Annalaura; Palombi, Leonardo; Bellecci, Carlo; Gaudio, Pasquale

    2015-01-01

    The Ebola virus epidemic burst in West Africa in late 2013, started in Guinea, reached in a few months an alarming diffusion, actually involving several countries (Liberia, Sierra Leone, Nigeria, Senegal, and Mali). Guinea and Liberia, the first nations affected by the outbreak, have put in place measures to contain the spread, supported by international organizations; then they were followed by the other nations affected. In the present EVD outbreak, the geographical spread of the virus has followed a new route: the achievement of large urban areas at an early stage of the epidemic has led to an unprecedented diffusion, featuring the largest outbreak of EVD of all time. This has caused significant concerns all over the world: the potential reaching of far countries from endemic areas, mainly through fast transports, induced several countries to issue information documents and health supervision for individuals going to or coming from the areas at risk. In this paper the geographical spread of the epidemic was analyzed, assessing the sequential appearance of cases by geographic area, considering the increase in cases and mortality according to affected nations. The measures implemented by each government and international organizations to contain the outbreak, and their effectiveness, were also evaluated. PMID:25852754

  9. Contagious yawning and the frontal lobe: an fMRI study.

    PubMed

    Nahab, Fatta B; Hattori, Noriaki; Saad, Ziad S; Hallett, Mark

    2009-05-01

    We conducted a slow event-related fMRI experiment with naďve subjects' passively viewing yawn and various other control videos along with correlative behavioral testing. Specifically associated with the viewing of the contagious yawn was an area of activation in the ventromedial prefrontal cortex. These findings suggest a role for the prefrontal cortex in the processing of contagious yawning, while demonstrating a unique automaticity in the processing of contagious motor programs which take place independently of mirror neuron networks. PMID:18937281

  10. Contagious Yawning and the Frontal Lobe: An fMRI Study

    PubMed Central

    Nahab, Fatta B.; Hattori, Noriaki; Saad, Ziad S.; Hallett, Mark

    2014-01-01

    We conducted a slow event-related fMRI experiment with naďve subjects’ passively viewing yawn and various other control videos along with correlative behavioral testing. Specifically associated with the viewing of the contagious yawn was an area of activation in the ventromedial prefrontal cortex. These findings suggest a role for the prefrontal cortex in the processing of contagious yawning, while demonstrating a unique automaticity in the processing of contagious motor programs which take place independently of mirror neuron networks. PMID:20357471

  11. Brief Report: Does Eye Contact Induce Contagious Yawning in Children with Autism Spectrum Disorder?

    Microsoft Academic Search

    Atsushi Senju; Yukiko Kikuchi; Hironori Akechi; Toshikazu Hasegawa; Yoshikuni Tojo; Hiroo Osanai

    2009-01-01

    Individuals with autism spectrum disorder (ASD) reportedly fail to show contagious yawning, but the mechanism underlying the\\u000a lack of contagious yawning is still unclear. The current study examined whether instructed fixation on the eyes modulates\\u000a contagious yawning in ASD. Thirty-one children with ASD, as well as 31 age-matched typically developing (TD) children, observed\\u000a video clips of either yawning or control

  12. Composition of a polysaccharide from mycoplasma (F-38) recognised by antibodies from goats with contagious pleuropneumonia.

    PubMed

    Rurangirwa, F R; McGuire, T C; Magnuson, N S; Kibor, A; Chema, S

    1987-03-01

    A polysaccharide was extracted by warm aqueous phenol from the F-38 strain of mycoplasma which causes contagious caprine pleuropneumonia (CCPP). After acid hydrolysis, the polysaccharide was found to be composed of the neutral sugars glucose, galactose, mannose and fucose and the amino sugars galactosamine and glucosamine. All the sugars were present in approximately equal quantities. Unmodified goat erythrocytes bound the polysaccharide readily and the sensitised cells reacted with antibodies in sera from goats with experimental or natural CCPP. The unique composition of the F-38 polysaccharide and the specific reactivity of polysaccharide-sensitised red cells with antibodies from CCPP infected animals suggests that the polysaccharide should be useful for identification of F-38 organisms and diagnosis of the disease. PMID:3589164

  13. Fatal transmission of contagious caprine pleuropneumonia to an Arabian oryx (Oryx leucoryx).

    PubMed

    Chaber, A L; Lignereux, L; Al Qassimi, M; Saegerman, C; Manso-Silván, L; Dupuy, V; Thiaucourt, F

    2014-09-17

    Contagious caprine pleuropneumonia (CCPP) is an infectious respiratory disease mainly affecting domestic goats. As CCPP has never been documented in grazing antelopes (subfamily hippotraginae), they were not considered susceptible. Mycoplasma capricolum subspecies capripneumoniae (Mccp) was isolated from pleural liquid collected during the necropsy of a severely emaciated Arabian oryx with mild nasal discharge. The Mccp isolate was then genotyped using a multilocus sequence scheme; the sequence type was identical to the Mccp strain previously identified in a sand gazelle from a nearby enclosure. This case shows for the first time that members of the hippotraginae subfamily, here the Arabian oryx, can be affected by CCPP. In addition, genotyping shows that the oryx was most probably infected, at a distance, by sand gazelles. PMID:25069622

  14. Contagious ecthyma in bighorn sheep and mountain goat in western Canada.

    PubMed

    Samuel, W M; Chalmers, G A; Stelfox, J G; Loewen, A; Thomsen, J J

    1975-01-01

    Contagious ecthyma (CE) is reported in bighorn sheep (Ovis c. canadensis) from several national parks in western Canada and in moutain goat (Oreamnos americanus) from Kootenay National Park, British Columbia. (This is the first report of CE in mountain goat.) Diagnosis was based on clinical signs, histopathology, transmission experiments and the demonstration of a proxvirus with the electron microscope. The infection was transmitted from wild to domestic goat, but not to domestic sheep. Most infections, some of them severe, were found in lambs and kids. Clinical signs of disease were similar to those seen in domestic sheep and goats. General body condition was poor and animals had difficulty feeding normally. All infected herds had prolonged contact with areas where salt was provided artificially (i.e., salt blocks, highways and campgrounds). Fewer infected sheep were observed annually when salt blocks were removed from Jasper National Park. PMID:1113436

  15. Yawn, yawn, yawn, yawn; yawn, yawn, yawn! The social, evolutionary and neuroscientific facets of contagious yawning.

    PubMed

    Platek, Steven M

    2010-01-01

    Contagious yawning is a common phenomenon affecting upwards of 60% of healthy humans. It has also been observed, at a lesser rate, in great apes and other primates. Here I summarize the suggestion that contagious yawning is a primitive expression of social cognition, namely empathy. Susceptibility to contagious yawning is correlated with the speed in recognizing one's own face, theory of mind processing, and is also associated with activation in regions of the brain that have been associated with social cognitive processes. This suggests that contagious yawning may be an evolutionarily old process that begot a higher level of social cognition in certain species. PMID:20357468

  16. Investigation of airborne foot-and-mouth disease virus transmission during low-wind conditions in the early phase of the UK 2001 epidemic

    NASA Astrophysics Data System (ADS)

    Mikkelsen, T.; Alexandersen, S.; Astrup, P.; Champion, H. J.; Donaldson, A. I.; Dunkerley, F. N.; Gloster, J.; Sřrensen, J. H.; Thykier-Nielsen, S.

    2003-02-01

    Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed domesticated and wild animals. The highly contagious nature of FMD is a reflection of the wide range of host species, the enormous quantities of virus liberated by infected animals, the range of excretions and secretions which can be infectious, the stability of the virus in the environment, the multiplicity of routes of infection and the very small doses of the virus that can initiate infection. One of the mechanisms of spread is the carriage of droplets and droplet nuclei exhaled in the breath of infected animals. Such spread can be rapid and extensive, and it is known in certain circumstances to have transmitted disease over a distance of several hundred kilometres. During the 2001 FMD epidemic in the United Kingdom (UK), atmospheric dispersion models were applied in real time in order to assess the potential for atmospheric dispersion of the disease. The operational value of such modelling is primarily to identify premises which may have been exposed so that the human resources for surveillance and disease control purposes are employed most effectively. The paper describes the combined modelling techniques and presents the results obtained of detailed analyses performed during the early stages of the UK 2001 epidemic. This paper investigates the potential for disease spread in relation to two outbreaks (Burnside Farm, Heddon-on-the-Wall and Prestwick Hall Farm, Ponteland, Northumberland). A separate paper (Gloster et al., 2002) provides a more detailed analysis of the airborne disease transmission in the vicinity of Burnside Farm. The combined results are consistent with airborne transmission of disease to livestock in the Heddon-on-the Wall area. Local topography may have played a significant role in influencing the pattern of disease spread.

  17. Investigation of airborne foot-and-mouth disease virus transmission during low-wind conditions in the early phase of the UK 2001 epidemic

    NASA Astrophysics Data System (ADS)

    Mikkelsen, T.; Alexandersen, S.; Astrup, P.; Champion, H. J.; Donaldson, A. I.; Dunkerley, F. N.; Gloster, J.; Sřrensen, J. H.; Thykier-Nielsen, S.

    2003-11-01

    Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed domesticated and wild animals. The highly contagious nature of FMD is a reflection of the wide range of host species, the enormous quantities of virus liberated by infected animals, the range of excretions and secretions which can be infectious, the stability of the virus in the environment, the multiplicity of routes of infection and the very small doses of the virus that can initiate infection. One of the mechanisms of spread is the carriage of droplets and droplet nuclei exhaled in the breath of infected animals. Such spread can be rapid and extensive, and it is known in certain circumstances to have transmitted disease over a distance of several hundred kilometres. During the 2001 FMD epidemic in the United Kingdom (UK), atmospheric dispersion models were applied in real time in order to assess the potential for atmospheric dispersion of the disease. The operational value of such modelling is primarily to identify premises which may have been exposed so that the human resources for surveillance and disease control purposes are employed most effectively.

    The paper describes the combined modelling techniques and presents the results obtained of detailed analyses performed during the early stages of the UK 2001 epidemic. This paper investigates the potential for disease spread in relation to two outbreaks (Burnside Farm, Heddon-on-the-Wall and Prestwick Hall Farm, Ponteland, Northumberland). A separate paper (Gloster et al., 2002) provides a more detailed analysis of the airborne disease transmission in the vicinity of Burnside Farm.

    The combined results are consistent with airborne transmission of disease to livestock in the Heddon-on-the-Wall area. Local topography may have played a significant role in influencing the pattern of disease spread.

  18. Spill Spread

    NSDL National Science Digital Library

    Lawrence Hall of Science

    2007-01-01

    In this simulation, learners explore how ocean currents spread all kinds of pollution—including oil spills, sewage, pesticides and factory waste—far beyond where the pollution originates. Learners create an experimental "ocean" (water in a tray) and "continents" (rocks), then add melting ice cubes to create temperature-driven currents in the water. Learners observe how "pollution," represented by food coloring, spreads through the model ocean affected by both "currents" and "continents." This activity can be used with lessons on ocean science or environmental hazards.

  19. Prevalence of Rabies in Various Species in Yemen and Risk Factors Contributing to the Spread of the Disease

    PubMed Central

    Al-Shamahy, Hassan A.; Sunhope, Ameera; Al-Moyed, Khaled A.

    2013-01-01

    Objectives: This study aimed to describe for the first time the prevalence of the passively-reported rabies virus among different domestic and wild animals submitted to the Central Veterinary Laboratory from various areas in Yemen, and to study prevalence proportion ratios (PPR) that contributed to the spread of rabies among animals, and its transmission to humans. Methods: A brain sample was obtained from each of the 180 animals and tested for rabies virus by a direct fluorescent antibody test. Results: Out of the total number of animals involved in attacks on humans, 63.3 % were positive for rabies. Of these, dogs were the main animal involved in attacks with a percentage of 92%, of which 62.7% were positive for rabies. Of animals involved in attacks, 70.6% were males of which 60.6% were positive, and 29.4% were females of which 69.8% were positive. Males comprised 68.9% of the total human individuals attacked, of whom 62.9% were attacked by rabies-positive animals. The significant risk factors that contributed to the spread of rabies in general included the presence of poultry carcasses and other waste in the vicinity of the attacks (PPR = 9.5) with a percentage of 84.8%, followed by the time of year, in particular school vacations (PPR = 3.8) with a percentage of 78%. Conclusion: Rabies is endemic in Yemen with a very high rabies-positive rate for animals involved in attacks, particularly for stray male dogs. Male children were most often involved in attacks by rabies-positive animals. The presence of food waste (particularly poultry carcasses) and school vacation periods were found to correlate significantly with increased risk for human exposure to rabies. PMID:23984026

  20. Ingroup-Outgroup Bias in Contagious Yawning by Chimpanzees Supports Link to Empathy

    Microsoft Academic Search

    Matthew W. Campbell; Frans B. M. de Waal; Georges Chapouthier

    2011-01-01

    Humans favor others seen as similar to themselves (ingroup) over people seen as different (outgroup), even without explicitly stated bias. Ingroup-outgroup bias extends to involuntary responses, such as empathy for pain. However, empathy biases have not been tested in our close primate relatives. Contagious yawning has been theoretically and empirically linked to empathy. If empathy underlies contagious yawning, we predict

  1. Hitting Is Contagious in Baseball: Evidence from Long Hitting Streaks

    PubMed Central

    Bock, Joel R.; Maewal, Akhilesh; Gough, David A.

    2012-01-01

    Data analysis is used to test the hypothesis that “hitting is contagious”. A statistical model is described to study the effect of a hot hitter upon his teammates’ batting during a consecutive game hitting streak. Box score data for entire seasons comprising streaks of length games, including a total observations were compiled. Treatment and control sample groups () were constructed from core lineups of players on the streaking batter’s team. The percentile method bootstrap was used to calculate confidence intervals for statistics representing differences in the mean distributions of two batting statistics between groups. Batters in the treatment group (hot streak active) showed statistically significant improvements in hitting performance, as compared against the control. Mean for the treatment group was found to be to percentage points higher during hot streaks (mean difference increased points), while the batting heat index introduced here was observed to increase by points. For each performance statistic, the null hypothesis was rejected at the significance level. We conclude that the evidence suggests the potential existence of a “statistical contagion effect”. Psychological mechanisms essential to the empirical results are suggested, as several studies from the scientific literature lend credence to contagious phenomena in sports. Causal inference from these results is difficult, but we suggest and discuss several latent variables that may contribute to the observed results, and offer possible directions for future research. PMID:23251507

  2. Spreading volcanoes

    USGS Publications Warehouse

    Borgia, A.; Delaney, P.T.; Denlinger, R.P.

    2000-01-01

    As volcanoes grow, they become ever heavier. Unlike mountains exhumed by erosion of rocks that generally were lithified at depth, volcanoes typically are built of poorly consolidated rocks that may be further weakened by hydrothermal alteration. The substrates upon which volcanoes rest, moreover, are often sediments lithified by no more than the weight of the volcanic overburden. It is not surprising, therefore, that volcanic deformation includes-and in the long term is often dominated by-spreading motions that translate subsidence near volcanic summits to outward horizontal displacements around the flanks and peripheries. We review examples of volcanic spreading and go on to derive approximate expressions for the time volcanoes require to deform by spreading on weak substrates. We also demonstrate that shear stresses that drive low-angle thrust faulting from beneath volcanic constructs have maxima at volcanic peripheries, just where such faults are seen to emerge. Finally, we establish a theoretical basis for experimentally derived scalings that delineate volcanoes that spread from those that do not.

  3. Contagious yawning: the role of self-awareness and mental state attribution.

    PubMed

    Platek, Steven M; Critton, Samuel R; Myers, Thomas E; Gallup, Gordon G

    2003-07-01

    Contagious yawning is a common, but poorly understood phenomenon. We hypothesized that contagious yawning is part of a more general phenomenon known as mental state attribution (i.e. the ability to inferentially model the mental states of others). To test this hypothesis we compared susceptibility to contagiously yawn with performance on a self-face recognition task, several theory of mind stories, and on a measure of schizotypal personality traits. Consistent with the hypothesis, susceptibility to contagiously yawn was positively related to performance on self-face recognition and faux pas theory of mind stories, and negatively related to schizotypal personality traits. These data suggest that contagious yawning may be associated with empathic aspects of mental state attribution and are negatively affected by increases in schizotypal personality traits much like other self-processing related tasks. PMID:12880893

  4. A simulation spatial model of the spread of foot-and-mouth disease through the primary movement of milk.

    PubMed

    Hugh-Jones, M E

    1976-08-01

    A computer model was constructed to mimic the 1967-8 foot-and-mouth epizootic in Shropshire and Cheshire, but the daily spatial distribution of outbreaks was randomized. This pattern of outbreaks was then examined to determine what percentage of outbreaks would fulfil and arbitrary set of criteria for milk-lorry-borne disease, or the primary movement of milk. Some 21% of herds visited subsequent to a 'source farm' were affected, as were 4% of herds visited after any infected herd. The relevance of these results to the true risk of disease through the primary movement of milk off affected farms is discussed. PMID:1068186

  5. The Science, Spread and Therapy of HIV Disease. Everything You Need To Know, but Had No Idea Who To Ask.

    ERIC Educational Resources Information Center

    DiSpezio, Michael A.

    This book uses a question-and-answer format to provide information on the Human Immunodeficiency Virus (HIV) and the disease caused by infection from the virus, Acquired Immune Deficiency Syndrome (AIDS). Topics covered include: (1) "Outbreak," which discusses the history of the AIDS outbreak including early theories about the causes of AIDS and…

  6. Comparative sequence analysis of a highly oncogenic but horizontal spread-defective clone of Marek's disease virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease virus (MDV) is a cell-associated alphaherpesvirus that induces rapid-onset T-cell lymphomas in poultry. MDV isolates vary greatly in pathogenicity. While some of the strains such as CVI988 are non-pathogenic and are used as vaccines, others such as RB1B are highly oncogenic. Compa...

  7. Emergence, spread and strategies for controlling the pandemic of cassava mosaic virus disease in east and central Africa

    Microsoft Academic Search

    J. P Legg

    1999-01-01

    During the 1990s, an epidemic of an unusually severe form of cassava mosaic virus disease (CMD) has expanded to cover virtually all of Uganda, and substantial areas in the neighbouring countries of Kenya, Tanzania, Sudan and the Democratic Republic of Congo. Losses in the generally sensitive local cassava cultivars have been so great that a common farmer response to the

  8. Sinusoidal spread of liver metastases from renal cell carcinoma: simulation of diffuse liver disease on MR imaging

    Microsoft Academic Search

    A. B. Nascimento; D. G. Mitchell; R. Rubin; E. Weaver

    2002-01-01

    Rarely, hepatic metastases can simulate hepatic infiltrative diseases. We present a case of a patient with advanced metastatic\\u000a renal cell carcinoma who developed hepatomegaly and clinical signs of hepatocellular injury. On magnetic resonance imaging,\\u000a the injury simulated a diffuse process, e.g., acute fulminant viral or chemical hepatitis or drug toxicity. Despite its high\\u000a resolution, magnetic resonance imaging might not depict

  9. A specific PCR for the identification of Mycoplasma capricolum subsp. capripneumoniae, the causative agent of contagious caprine pleuropneumonia (CCPP).

    PubMed

    Woubit, S; Lorenzon, S; Peyraud, A; Manso-Silván, L; Thiaucourt, F

    2004-11-30

    Contagious caprine pleuropneumonia is a severe infectious disease of goats in Africa and the Middle East. It is caused by a fastidious mycoplasma, Mycoplasma capricolum subsp. capripneumoniae, a member of the "M. mycoides cluster". Members of this cluster share genomic and antigenic features, which result in common biochemical and serological properties, complicating species identification. Two species of this cluster, M. mycoides subsp. capri and M. mycoides subsp. mycoides large colony biotype, are very often isolated from clinical cases resembling contagious caprine pleuropneumonia. Furthermore, in the laboratory, M. capricolum subsp. capripneumoniae can be easily confused with the closely related capricolum subspecies. Considering these constraints and the scarcity of available methods for identification, a specific polymerase chain reaction was developed. A DNA fragment of 7109 bp containing genes coding for the arginine deiminase pathway (ADI) was chosen as target sequence for the selection of a specific primer pair. The full ADI operon from M. capricolum subsp. capripneumoniae strain GL100 was sequenced. Polymorphism within this locus was analyzed by comparison with the sequence from the closely related IPX strain (M. capricolum subsp. capricolum). It varied from 0.6% to 3.5%. The highest divergence was found in a region coding for arcD. Therefore, this gene was chosen as target for the specific amplification of a 316 bp-long DNA fragment. The specificity of this PCR was validated on 14 M. capricolum subsp. capripneumoniae strains and 27 heterologous strains belonging to the "M. mycoides cluster" and M. putrefaciens. This new PCR will be a valuable tool for the surveillance of contagious caprine pleuropneumonia. PMID:15530747

  10. 9 CFR 93.515 - Appearance of disease among swine in quarantine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Appearance of disease among swine in quarantine. 93.515...CONTAINERS Swine § 93.515 Appearance of disease among swine in quarantine. If any contagious disease appears among swine during the...

  11. 9 CFR 93.416 - Appearance of disease among ruminants in quarantine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Appearance of disease among ruminants in quarantine. 93... Ruminants § 93.416 Appearance of disease among ruminants in quarantine. If any contagious disease appears among ruminants during...

  12. 9 CFR 93.213 - Appearance of disease among poultry in quarantine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Appearance of disease among poultry in quarantine. 93.213... Poultry § 93.213 Appearance of disease among poultry in quarantine. If any contagious disease appears among poultry during the...

  13. Poleward Expansion of the White-Footed Mouse (Peromyscus leucopus) under Climate Change: Implications for the Spread of Lyme Disease

    PubMed Central

    Roy-Dufresne, Emilie; Logan, Travis; Simon, Julie A.; Chmura, Gail L.; Millien, Virginie

    2013-01-01

    The white-footed mouse (Peromyscus leucopus) is an important reservoir host for Borrelia burgdorferi, the pathogen responsible for Lyme disease, and its distribution is expanding northward. We used an Ecological Niche Factor Analysis to identify the climatic factors associated with the distribution shift of the white-footed mouse over the last 30 years at the northern edge of its range, and modeled its current and potential future (2050) distributions using the platform BIOMOD. A mild and shorter winter is favouring the northern expansion of the white-footed mouse in Québec. With more favorable winter conditions projected by 2050, the distribution range of the white-footed mouse is expected to expand further northward by 3° latitude. We also show that today in southern Québec, the occurrence of B. burgdorferi is associated with high probability of presence of the white-footed mouse. Changes in the distribution of the white-footed mouse will likely alter the geographical range of B. burgdorferi and impact the public health in northern regions that have yet to be exposed to Lyme disease. PMID:24260464

  14. Poleward expansion of the white-footed mouse (Peromyscus leucopus) under climate change: implications for the spread of lyme disease.

    PubMed

    Roy-Dufresne, Emilie; Logan, Travis; Simon, Julie A; Chmura, Gail L; Millien, Virginie

    2013-01-01

    The white-footed mouse (Peromyscus leucopus) is an important reservoir host for Borrelia burgdorferi, the pathogen responsible for Lyme disease, and its distribution is expanding northward. We used an Ecological Niche Factor Analysis to identify the climatic factors associated with the distribution shift of the white-footed mouse over the last 30 years at the northern edge of its range, and modeled its current and potential future (2050) distributions using the platform BIOMOD. A mild and shorter winter is favouring the northern expansion of the white-footed mouse in Québec. With more favorable winter conditions projected by 2050, the distribution range of the white-footed mouse is expected to expand further northward by 3° latitude. We also show that today in southern Québec, the occurrence of B. burgdorferi is associated with high probability of presence of the white-footed mouse. Changes in the distribution of the white-footed mouse will likely alter the geographical range of B. burgdorferi and impact the public health in northern regions that have yet to be exposed to Lyme disease. PMID:24260464

  15. BBC News In Depth: Foot and Mouth Disease

    NSDL National Science Digital Library

    2001-01-01

    Foot and mouth disease is a highly contagious but not necessarily fatal viral infection that is transmitted through dust particles in the air, infecting the hooves and mouths of pigs, cattle, sheep, and goats. In recent weeks, a string of cases have been reported in England, sparking fears of another repeat of the epidemic of 1967, in which over 400,000 animals were destroyed. Farmers and government officials have so far followed the standard plan for dealing with such outbreaks: isolate affected farms and destroy infected herds. As part of this effort, local authorities have been empowered to prevent all foot traffic in designated areas and there has even been talk of delaying the impending general election in Britain for fear that politicians and staff on the campaign trail might spread the disease. This site, a special report from the BBC, contains breaking news, analysis, background information, and audio and video selections.

  16. Experimental contagious ecthyma in mule deer, white-tailed deer, pronghorn and wapiti.

    PubMed

    Lance, W R; Hibler, C P; DeMartini, J

    1983-07-01

    Hand-reared mule deer fawns (Odocoileus hemionus), white-tailed deer fawns (Odocoileus virginianus), pronghorn fawns (Antilocapra americana) and wapiti calves (Cervus elaphus nelsoni) were exposed to contagious ecthyma lesion material obtained from Rocky Mountain bighorn sheep (Ovis canadensis canadensis) to determine the susceptibility and pathogenesis in these species. All four species developed mucocutaneous proliferative lesions of the oral cavity, grossly and histologically compatible with contagious ecthyma. The limited clinical responses to the virus indicated that contagious ecthyma would not seriously impact free-ranging individuals. PMID:6685778

  17. Effect of danofloxacin (Advocin A180) on goats affected with contagious caprine pleuropneumonia.

    PubMed

    Ozdemir, U; Loria, G R; Godinho, K S; Samson, R; Rowan, T G; Churchward, C; Ayling, R D; Nicholas, R A J

    2006-01-01

    The efficacy of danofloxacin (Advocin A180) was evaluated for the treatment of contagious caprine pleuropneumonia (CCPP) caused by Mycoplasma capricolum subsp. capripneumoniae. Ten healthy Angora goats, confirmed free of CCPP, were exposed to clinically affected animals from a natural outbreak in Thrace, Turkey. After 14 days exposure, 8 goats showed pyrexia ( > or = 41 degrees C). Shortly after, the Angora goats were divided randomly into two groups. Five of these were injected with danofloxacin (6 mg/kg subcutaneously), which was repeated after 48 h; the five remaining animals received saline. Goats were monitored clinically and blood samples were collected for serology. Animals with severe disease were withdrawn from the trial. Goats completing the study were euthanized at day 42. Lung tissue and bronchial fluid were collected for mycoplasma isolation. All danofloxacin-treated goats showed resolution of clinical disease by the end of the trial. Two saline-treated goats failed to complete the study owing to CCPP. Danofloxacin-treated goats showed fewer lung lesions and had significantly lower combined clinical scores than saline controls (p < 0.001). Danofloxacin was found to be highly effective in the treatment of CCPP in goats. PMID:17265768

  18. Immunoglobulin epitope spreading and autoimmune disease after peptide immunization: Sm B/B'-derived PPPGMRPP and PPPGIRGP induce spliceosome autoimmunity

    PubMed Central

    1995-01-01

    Autoantibodies from many patients with systemic lupus erythematosus bind the Sm autoantigen B/B' polypeptide. The binding of serial serum specimens to the 233 overlapping octapeptides of Sm B/B' have shown that of the B/B'-derived octapeptides, PPPGMRPP and PPPGIRGP are early targets of the autoimmune response in some lupus patients. Rabbits immunized with PPPGMRPP and PPPGIRGP develop antibodies which not only bind these octapeptides, but also subsequently bind many other octapeptides of Sm B/B'. Eventually, the rabbits immunized with one octapeptide develop autoantibodies that bind other spliceosomal proteins including D, 70K, A, and C. Any mechanisms that operate to maintain tolerance or anergy for the spliceosome are thus overcome. Features considered typical of human systemic lupus erythematosus are also found in these peptide-immunized animals, such as antinuclear antibodies, anti-Sm precipitins, anti-double-stranded DNA, thrombocytopenia, seizures, and proteinuria. This disease model provides access to a mechanism for the development of humoral autoimmunity and may provide a basis to explain the immunopathogenesis of lupus in humans. PMID:7530756

  19. Interspecific competition in honeybee intracellular gut parasites is asymmetric and favours the spread of an emerging infectious disease.

    PubMed

    Natsopoulou, Myrsini E; McMahon, Dino P; Doublet, Vincent; Bryden, John; Paxton, Robert J

    2015-01-01

    There is increasing appreciation that hosts in natural populations are subject to infection by multiple parasite species. Yet the epidemiological and ecological processes determining the outcome of mixed infections are poorly understood. Here, we use two intracellular gut parasites (Microsporidia), one exotic and one co-evolved in the western honeybee (Apis mellifera), in an experiment in which either one or both parasites were administered either simultaneously or sequentially. We provide clear evidence of within-host competition; order of infection was an important determinant of the competitive outcome between parasites, with the first parasite significantly inhibiting the growth of the second, regardless of species. However, the strength of this 'priority effect' was highly asymmetric, with the exotic Nosema ceranae exhibiting stronger inhibition of Nosema apis than vice versa. Our results reveal an unusual asymmetry in parasite competition that is dependent on order of infection. When incorporated into a mathematical model of disease prevalence, we find asymmetric competition to be an important predictor of the patterns of parasite prevalence found in nature. Our findings demonstrate the wider significance of complex multi-host-multi-parasite interactions as drivers of host-pathogen community structure. PMID:25429014

  20. Animal Ownership and Touching Enrich the Context of Social Contacts Relevant to the Spread of Human Infectious Diseases

    PubMed Central

    Kifle, Yimer Wasihun; Goeyvaerts, Nele; Van Kerckhove, Kim; Willem, Lander; Faes, Christel; Leirs, Herwig; Hens, Niel; Beutels, Philippe

    2015-01-01

    Many human infectious diseases originate from animals or are transmitted through animal vectors. We aimed to identify factors that are predictive of ownership and touching of animals, assess whether animal ownership influences social contact behavior, and estimate the probability of a major zoonotic outbreak should a transmissible influenza-like pathogen be present in animals, all in the setting of a densely populated European country. A diary-based social contact survey (n = 1768) was conducted in Flanders, Belgium, from September 2010 until February 2011. Many participants touched pets (46%), poultry (2%) or livestock (2%) on a randomly assigned day, and a large proportion of participants owned such animals (51%, 15% and 5%, respectively). Logistic regression models indicated that larger households are more likely to own an animal and, unsurprisingly, that animal owners are more likely to touch animals. We observed a significant effect of age on animal ownership and touching. The total number of social contacts during a randomly assigned day was modeled using weighted-negative binomial regression. Apart from age, household size and day type (weekend versus weekday and regular versus holiday period), animal ownership was positively associated with the total number of social contacts during the weekend. Assuming that animal ownership and/or touching are at-risk events, we demonstrate a method to estimate the outbreak potential of zoonoses. We show that in Belgium animal-human interactions involving young children (0–9 years) and adults (25–54 years) have the highest potential to cause a major zoonotic outbreak. PMID:26193480

  1. Ingroup-outgroup bias in contagious yawning by chimpanzees supports link to empathy.

    PubMed

    Campbell, Matthew W; de Waal, Frans B M

    2011-01-01

    Humans favor others seen as similar to themselves (ingroup) over people seen as different (outgroup), even without explicitly stated bias. Ingroup-outgroup bias extends to involuntary responses, such as empathy for pain. However, empathy biases have not been tested in our close primate relatives. Contagious yawning has been theoretically and empirically linked to empathy. If empathy underlies contagious yawning, we predict that subjects should show an ingroup-outgroup bias by yawning more in response to watching ingroup members yawn than outgroup. Twenty-three chimpanzees (Pan troglodytes) from two separate groups watched videos of familiar and unfamiliar individuals yawning or at rest (control). The chimpanzees yawned more when watching the familiar yawns than the familiar control or the unfamiliar yawns, demonstrating an ingroup-outgroup bias in contagious yawning. These results provide further empirical support that contagious yawning is a measure of empathy, which may be useful for evolutionary biology and mental health. PMID:21494669

  2. Brief report: does eye contact induce contagious yawning in children with autism spectrum disorder?

    PubMed

    Senju, Atsushi; Kikuchi, Yukiko; Akechi, Hironori; Hasegawa, Toshikazu; Tojo, Yoshikuni; Osanai, Hiroo

    2009-11-01

    Individuals with autism spectrum disorder (ASD) reportedly fail to show contagious yawning, but the mechanism underlying the lack of contagious yawning is still unclear. The current study examined whether instructed fixation on the eyes modulates contagious yawning in ASD. Thirty-one children with ASD, as well as 31 age-matched typically developing (TD) children, observed video clips of either yawning or control mouth movements. Participants were instructed to fixate to the eyes of the face stimuli. Following instructed fixation on the eyes, both TD children and children with ASD yawned equally frequently in response to yawning stimuli. Current results suggest that contagious yawning could occur in ASD under an experimental condition in which they are instructed to fixate on the yawning eyes. PMID:19533316

  3. Ingroup-Outgroup Bias in Contagious Yawning by Chimpanzees Supports Link to Empathy

    PubMed Central

    Campbell, Matthew W.; de Waal, Frans B. M.

    2011-01-01

    Humans favor others seen as similar to themselves (ingroup) over people seen as different (outgroup), even without explicitly stated bias. Ingroup-outgroup bias extends to involuntary responses, such as empathy for pain. However, empathy biases have not been tested in our close primate relatives. Contagious yawning has been theoretically and empirically linked to empathy. If empathy underlies contagious yawning, we predict that subjects should show an ingroup-outgroup bias by yawning more in response to watching ingroup members yawn than outgroup. Twenty-three chimpanzees (Pan troglodytes) from two separate groups watched videos of familiar and unfamiliar individuals yawning or at rest (control). The chimpanzees yawned more when watching the familiar yawns than the familiar control or the unfamiliar yawns, demonstrating an ingroup-outgroup bias in contagious yawning. These results provide further empirical support that contagious yawning is a measure of empathy, which may be useful for evolutionary biology and mental health. PMID:21494669

  4. Participatory investigation of Contagious Caprine Pleuropneumonia (CCPP) in goats in the Hammer and Benna-Tsemay districts of southern Ethiopia.

    PubMed

    Mekuria, S; Zerihun, A; Gebre-Egziabher, B; Tibbo, M

    2008-12-01

    The study was conducted in two selected districts of Southern Omo zones of Ethiopia, namely Hammer and Benna-Tsemay, during November 2004 and May 2005 to determine the status of contagious caprine pleuropneumonia (CCPP). Participatory disease investigation was conducted in the goat flocks owned by pastoralists of the districts. Participatory methods such as proportionate piling and matrix scoring of diseases were used to characterise major diseases of goats. Clinical and post-mortem examinations and isolation of the causative agent of CCPP were done. Serological tests were conducted using CFT. CCPP (locally termed Sompo) ranked as the first important disease of goats in the study area. Local perception of causes and signs of CCPP were described. Matrix scoring between groups revealed that disease signs and causes showed weak, moderate and good agreement by Kendall's coefficient concordance (W = 0.21-0.99). The overall sero-prevalence of CCPP was 15.5%. The causative agent was isolated from sick animals in the lab. The characteristic clinical signs, gross lesions, bacteriological isolation of the causative agent supported by participatory epidemiological disease investigation revealed that CCPP is a major disease of goats in the study districts. Participatory epidemiology using indigenous knowledge could efficiently be used to generate sufficient information with minimum cost, local materials and within reasonably short period of time, assisting the designing of feasible disease control programme in developing countries. PMID:18975122

  5. The daily time course of contagious and spontaneous yawning among humans

    Microsoft Academic Search

    Fiorenza Giganti; Iole Zilli

    2011-01-01

    Yawning, besides being a spontaneous behavior, can also be evoked by observing others yawn. However, contagious yawning does\\u000a not always occur, depending possibly on several factors, such as one’s propensity to spontaneously yawn and a heightened level\\u000a of sleepiness. The aim of this study is to investigate in young adults whether contagious yawning frequency varies throughout\\u000a the day, and if

  6. Spread Supersymmetry

    NASA Astrophysics Data System (ADS)

    Hall, Lawrence J.; Nomura, Yasunori

    2012-01-01

    In the multiverse the scale of supersymmetry breaking, widetilde{m} = {F_X}/{M_{ * }} ?, may scan and environmental constraints on the dark matter density may exclude a large range of m from the reheating temperature after inflation down to values that yield a lightest supersymmetric particle (LSP) mass of order a TeV. After selection effects, for example from the cosmological constant, the distribution for widetilde{m} in the region that gives a TeV LSP may prefer larger values. A single environmental constraint from dark matter can then lead to multi-component dark matter, including both axions and the LSP, giving a TeV-scale LSP somewhat lighter than the corresponding value for single-component LSP dark matter. If supersymmetry breaking is mediated to the Standard Model sector at order X † X and higher, only squarks, sleptons and one Higgs doublet acquire masses of order widetilde{m} . The gravitino mass is lighter by a factor of M ? /M Pl and the gaugino masses are suppressed by a further loop factor. This Spread Supersymmetry spectrum has two versions, one with Higgsino masses arising from supergravity effects of order the gravitino mass giving a wino LSP, and another with the Higgsino masses generated radiatively from gaugino masses giving a Higgsino LSP. The environmental restriction on dark matter fixes the LSP mass to the TeV domain, so that the squark and slepton masses are order 103 TeV and 106 TeV in these two schemes. We study the spectrum, dark matter and collider signals of these two versions of Spread Supersymmetry. The Higgs boson is Standard Model-like and predicted to lie in the range 110-145 GeV; monochromatic photons in cosmic rays arise from dark matter annihilations in the halo; exotic short charged tracks occur at the LHC, at least for the wino LSP; and there are the eventual possibilities of direct detection of dark matter and detailed exploration of the TeV-scale states at a future linear collider. Gauge coupling unification is at least as precise as in minimal supersymmetric theories. If supersymmetry breaking is also mediated at order X, a much less hierarchical spectrum results. The spectrum in this case is similar to that of the Minimal Supersymmetric Standard Model, but with the superpartner masses 1-2 orders of magnitude larger than those expected in natural theories.

  7. Late lesions of experimental contagious caprine pleuropneumonia caused by Mycoplasma capricolum ssp. capripneumoniae.

    PubMed

    Wesonga, H O; Lindberg, R; Litamoi, J K; Bölske, G

    1998-03-01

    A clinical, bacteriological, serological and patho-anatomical study was carried out on 12 goats surviving the acute stage of contagious caprine pleuropneumonia (CCPP), experimentally produced with Mycoplasma capricolum ssp. capripneumoniae (M. capripneumoniae), with the major aims of investigating the chronic stage of the disease and elucidating the possibility of a carrier state beyond the acute fulminant phase. The goats were killed 9, 16, 82 or 126 days after the onset of acute clinical signs. On day 9, clinical signs included low grade fever and persistent coughing. Thereafter, only intermittent coughing was recorded. Serum titres of complement-fixing antibodies to M. capripneumoniae were high at the period of fever but dropped thereafter. Post-mortem examination showed acute fibrinous pleuropneumonia on days 9 and 16, and chronic pleuropneumonia on days 82 and 126, including sequester formations in goats killed on day 126. Mycoplasma capripneumoniae was isolated on days 9 and 16 but not on later occasions. The study showed that goats recovered from acute CCPP may have lesions for a long time thereafter but provide no evidence of a carrier state among long-term survivors. PMID:9557132

  8. Detection of contagious caprine pleuropneumonia in East Turkey.

    PubMed

    Cetinkaya, B; Kalin, R; Karahan, M; Atil, E; Manso-Silván, L; Thiaucourt, F

    2009-12-01

    A study was implemented to investigate the presence of contagious caprine pleuropneumonia (CCPP) in East Turkey. This study was based on clinical surveillance in the field, surveillance at regional slaughterhouses and regular submission of suspected lesions to regional laboratories. The results showed that the agent of CCPP, Mycoplasma capricolum subspecies capripneumoniae (Mccp), could be detected by culture and specific polymerase chain reaction from 37.5% (12/32) of lung samples taken from goats of ten different herds. This agent was also isolated from two of 13 sheep samples (one from the lung and the other from a nasal swab). Mycoplasma capricolum subsp. capripneumoniae was isolated in pure culture and characterised at a finer molecular level. The East Turkish isolate was found to be closely related to another strain of Turkish origin, as well as to Mccp strains isolated in Tunisia. The isolation of Mccp from sheep lung lesions brings the strict host-specificity of this pathogen into question. It may also indicate that Mccp presents a risk for wildlife in the region. Such results, the authors believe, demonstrate that adequate risk assessments should be undertaken in Turkey and neighbouring countries. PMID:20462161

  9. Genetic control of contagious asexuality in the pea aphid.

    PubMed

    Jaquiéry, Julie; Stoeckel, Solenn; Larose, Chloé; Nouhaud, Pierre; Rispe, Claude; Mieuzet, Lucie; Bonhomme, Joël; Mahéo, Frédérique; Legeai, Fabrice; Gauthier, Jean-Pierre; Prunier-Leterme, Nathalie; Tagu, Denis; Simon, Jean-Christophe

    2014-12-01

    Although evolutionary transitions from sexual to asexual reproduction are frequent in eukaryotes, the genetic bases of such shifts toward asexuality remain largely unknown. We addressed this issue in an aphid species where both sexual and obligate asexual lineages coexist in natural populations. These sexual and asexual lineages may occasionally interbreed because some asexual lineages maintain a residual production of males potentially able to mate with the females produced by sexual lineages. Hence, this species is an ideal model to study the genetic basis of the loss of sexual reproduction with quantitative genetic and population genomic approaches. Our analysis of the co-segregation of ? 300 molecular markers and reproductive phenotype in experimental crosses pinpointed an X-linked region controlling obligate asexuality, this state of character being recessive. A population genetic analysis (>400-marker genome scan) on wild sexual and asexual genotypes from geographically distant populations under divergent selection for reproductive strategies detected a strong signature of divergent selection in the genomic region identified by the experimental crosses. These population genetic data confirm the implication of the candidate region in the control of reproductive mode in wild populations originating from 700 km apart. Patterns of genetic differentiation along chromosomes suggest bidirectional gene flow between populations with distinct reproductive modes, supporting contagious asexuality as a prevailing route to permanent parthenogenesis in pea aphids. This genetic system provides new insights into the mechanisms of coexistence of sexual and asexual aphid lineages. PMID:25473828

  10. Genetic Control of Contagious Asexuality in the Pea Aphid

    PubMed Central

    Jaquiéry, Julie; Stoeckel, Solenn; Larose, Chloé; Nouhaud, Pierre; Rispe, Claude; Mieuzet, Lucie; Bonhomme, Joël; Mahéo, Frédérique; Legeai, Fabrice; Gauthier, Jean-Pierre; Prunier-Leterme, Nathalie; Tagu, Denis; Simon, Jean-Christophe

    2014-01-01

    Although evolutionary transitions from sexual to asexual reproduction are frequent in eukaryotes, the genetic bases of such shifts toward asexuality remain largely unknown. We addressed this issue in an aphid species where both sexual and obligate asexual lineages coexist in natural populations. These sexual and asexual lineages may occasionally interbreed because some asexual lineages maintain a residual production of males potentially able to mate with the females produced by sexual lineages. Hence, this species is an ideal model to study the genetic basis of the loss of sexual reproduction with quantitative genetic and population genomic approaches. Our analysis of the co-segregation of ?300 molecular markers and reproductive phenotype in experimental crosses pinpointed an X-linked region controlling obligate asexuality, this state of character being recessive. A population genetic analysis (>400-marker genome scan) on wild sexual and asexual genotypes from geographically distant populations under divergent selection for reproductive strategies detected a strong signature of divergent selection in the genomic region identified by the experimental crosses. These population genetic data confirm the implication of the candidate region in the control of reproductive mode in wild populations originating from 700 km apart. Patterns of genetic differentiation along chromosomes suggest bidirectional gene flow between populations with distinct reproductive modes, supporting contagious asexuality as a prevailing route to permanent parthenogenesis in pea aphids. This genetic system provides new insights into the mechanisms of coexistence of sexual and asexual aphid lineages. PMID:25473828

  11. Fifth Disease

    MedlinePLUS

    ... are immune. How is fifth disease spread? Fifth disease is spread by coming into contact with saliva or mucus carrying the virus. For example, it can be spread by coughing, sneezing or sharing items. Frequent hand washing may ... Don’t worry! Fifth disease is caused by parvovirus, but it isn’t ...

  12. 62 FR 8867 - Change in Disease Status of the Netherlands Because of Hog Cholera

    Federal Register 2010, 2011, 2012, 2013, 2014

    1997-02-27

    ...Netherlands. Hog cholera is a contagious viral disease of swine. The impact...of a Potential Hog Cholera Outbreak...forth, from infection of herds in a...DISEASE, AFRICAN SWINE FEVER, HOG CHOLERA, AND...

  13. Role of the Leucine Zipper of Marek's Disease Virus Oncoprotein Meq in Pathogenesis

    E-print Network

    Suchodolski, Paulette F.

    2010-07-14

    Marek's disease virus (MDV), the etiologic agent of Marek's disease, is a potent oncogenic herpesvirus. MDV is highly contagious and elicits a rapid onset of malignant T-cell lymphomas in chickens within several weeks after infection. The MDV genome...

  14. Parallelization: Infectious Disease

    NSDL National Science Digital Library

    Aaron Weeden

    Epidemiology is the study of infectious disease. Infectious diseases are said to be "contagious" among people if they are transmittable from one person to another. Epidemiologists can use models to assist them in predicting the behavior of infectious diseases. This module will develop a simple agent-based infectious disease model, develop a parallel algorithm based on the model, provide a coded implementation for the algorithm, and explore the scaling of the coded implementation on high performance cluster resources.

  15. Familiarity Bias and Physiological Responses in Contagious Yawning by Dogs Support Link to Empathy

    PubMed Central

    Romero, Teresa; Konno, Akitsugu; Hasegawa, Toshikazu

    2013-01-01

    In humans, the susceptibility to yawn contagion has been theoretically and empirically related to our capacity for empathy. Because of its relevance to evolutionary biology, this phenomenon has been the focus of recent investigations in non-human species. In line with the empathic hypothesis, contagious yawning has been shown to correlate with the level of social attachment in several primate species. Domestic dogs (Canis familiaris) have also shown the ability to yawn contagiously. To date, however, the social modulation of dog contagious yawning has received contradictory support and alternative explanations (i.e., yawn as a mild distress response) could explain positive evidence. The present study aims to replicate contagious yawning in dogs and to discriminate between the two possible mediating mechanisms (i.e., empathic vs. distress related response). Twenty-five dogs observed familiar (dog’s owner) and unfamiliar human models (experimenter) acting out a yawn or control mouth movements. Concurrent physiological measures (heart rate) were additionally monitored for twenty-one of the subjects. The occurrence of yawn contagion was significantly higher during the yawning condition than during the control mouth movements. Furthermore, the dogs yawned more frequently when watching the familiar model than the unfamiliar one demonstrating that the contagiousness of yawning in dogs correlated with the level of emotional proximity. Moreover, subjects’ heart rate did not differ among conditions suggesting that the phenomenon of contagious yawning in dogs is unrelated to stressful events. Our findings are consistent with the view that contagious yawning is modulated by affective components of the behavior and may indicate that rudimentary forms of empathy could be present in domesticated dogs. PMID:23951146

  16. Familiarity bias and physiological responses in contagious yawning by dogs support link to empathy.

    PubMed

    Romero, Teresa; Konno, Akitsugu; Hasegawa, Toshikazu

    2013-01-01

    In humans, the susceptibility to yawn contagion has been theoretically and empirically related to our capacity for empathy. Because of its relevance to evolutionary biology, this phenomenon has been the focus of recent investigations in non-human species. In line with the empathic hypothesis, contagious yawning has been shown to correlate with the level of social attachment in several primate species. Domestic dogs (Canis familiaris) have also shown the ability to yawn contagiously. To date, however, the social modulation of dog contagious yawning has received contradictory support and alternative explanations (i.e., yawn as a mild distress response) could explain positive evidence. The present study aims to replicate contagious yawning in dogs and to discriminate between the two possible mediating mechanisms (i.e., empathic vs. distress related response). Twenty-five dogs observed familiar (dog's owner) and unfamiliar human models (experimenter) acting out a yawn or control mouth movements. Concurrent physiological measures (heart rate) were additionally monitored for twenty-one of the subjects. The occurrence of yawn contagion was significantly higher during the yawning condition than during the control mouth movements. Furthermore, the dogs yawned more frequently when watching the familiar model than the unfamiliar one demonstrating that the contagiousness of yawning in dogs correlated with the level of emotional proximity. Moreover, subjects' heart rate did not differ among conditions suggesting that the phenomenon of contagious yawning in dogs is unrelated to stressful events. Our findings are consistent with the view that contagious yawning is modulated by affective components of the behavior and may indicate that rudimentary forms of empathy could be present in domesticated dogs. PMID:23951146

  17. The value of animal movement tracing: a case study simulating the spread and control of foot-and-mouth disease in California.

    PubMed

    Mardones, F O; Zu Donha, H; Thunes, C; Velez, V; Carpenter, T E

    2013-06-01

    The purpose of this study was to estimate the benefits of an electronic animal tracing system and an improved paper-based system in terms of the potential spread of foot-and-mouth disease (FMD) if introduced in California. A spatial, stochastic simulation model and data for California were used to simulate FMD outbreaks originating from a dairy herd as the index case (IC). Descriptive statistics of the simulated FMD outbreak extent and duration were examined to determine the benefit of an electronic system or paper-based tracing systems of varying efficacies. According to the simulations, an electronic tracing system would reduce the median number of infected premises (IPs) by 8-81%, depending on size of the IC herd compared with the results expected from identifying IPs based on clinical signs alone. The benefit also varied by IP herd type, e.g. ? 50% for sheep farms, goat farms and calf and heifer raising operations and ? 20% for swine and beef premises. The electronic system simulated a decrease in the median duration from at least 200d to 42d, if the IC were a small dairy and from 110d to 45d if the IC were a large dairy. The impact of an introduction of FMD in California could be reduced substantially even without an electronic system, if paper-based tracing were more efficient; however, these benefits are far less than those that could be realized from an electronic animal identification system. Results show that substantial benefits, in terms of fewer IPs and infected animals and reduced epidemic duration, may be realized as a result of an efficient electronic animal identification system, compared with a paper-based animal tracing system; however, until then, an improvement in the current system, especially regarding the ability to trace movements the day prior to a premises being diagnosed with FMD, may be highly beneficial. PMID:23260796

  18. Contagious seed dispersal beneath heterospecific fruiting trees and its consequences.

    SciTech Connect

    Kwit, Charles; Levey, Douglas, J.; Greenberg, Cathyrn, H.

    2004-05-03

    Kwit, Charles, D.J. Levey and Cathryn H. Greenberg. 2004. Contagious seed dispersal beneath heterospecific fruiting trees and its consequences. Oikos. 107:303-308 A n hypothesized advantage of seed dispersal is avoidance of high per capita mortality (i.e. density-dependent mortality) associated with dense populations of seeds and seedlings beneath parent trees. This hypothesis, inherent in nearly all seed dispersal studies, assumes that density effects are species-specific. Yet because many tree species exhibit overlapping fruiting phenologies and share dispersers, seeds may be deposited preferentially under synchronously fruiting heterospecific trees, another location where they may be particularly vulnerable to mortality, in this case by generalist seed predators. We demonstrate that frugivores disperse higher densities of Cornus florida seeds under fruiting (female) I lex opaca trees than under non-fruiting (male) I lex trees in temperate hardwood forest settings in South Carolina, U SA . To determine if density of Cornus and/or I lex seeds influences survivorship of dispersed Cornus seeds, we followed the fates of experimentally dispersed Cornus seeds in neighborhoods of differing, manipulated background densities of Cornus and I lex seeds. We found that the probability of predation on dispersed Cornus seeds was a function of both Cornus and I lex background seed densities. H igher densities of I lex seeds negatively affected Cornus seed survivorship, and this was particularly evident as background densities of dispersed Cornus seeds increased. These results illustrate the importance of viewing seed dispersal and predation in a community context, as the pattern and intensity of density-dependent mortality may not be solely a function of conspecific densities.

  19. Reproductive Diseases in Cattle 

    E-print Network

    Sprott, L. R.; Field, Bob

    1998-12-03

    , aborted usually 6-9 percent of herd at 2-4 weeks mine the type of lepto fetuses months before breeding. causing infection. Red nose (IBR) Viral Contagious from 6-9 months Fetus; placenta; Killed or modified Abortion may or may cow to cow blood samples live... vaccine. See not be associated with veterinarian. illness in cows. Virus diarrhea Viral Contagious from Variable, Two blood Killed or modified Calves born with disease (BVD) cow to cow usually early samples, 3 live vaccine. See (loss of hair, brain...

  20. Infectious Diseases in Day Care.

    ERIC Educational Resources Information Center

    Sleator, Esther K.

    Discussed in this publication are infectious illnesses for which children attending day care appear to be at special risk. Also covered are the common cold, some infectious disease problems receiving media attention, and some other annoying but not serious diseases, such as head lice, pinworms, and contagious skin conditions. Causes,…

  1. Contagious yawning in gelada baboons as a possible expression of empathy

    PubMed Central

    Palagi, E.; Leone, A.; Mancini, G.; Ferrari, P. F.

    2009-01-01

    Yawn contagion in humans has been proposed to be related to our capacity for empathy. It is presently unclear whether this capacity is uniquely human or shared with other primates, especially monkeys. Here, we show that in gelada baboons (Theropithecus gelada) yawning is contagious between individuals, especially those that are socially close, i.e., the contagiousness of yawning correlated with the level of grooming contact between individuals. This correlation persisted after controlling for the effect of spatial association. Thus, emotional proximity rather than spatial proximity best predicts yawn contagion. Adult females showed precise matching of different yawning types, which suggests a mirroring mechanism that activates shared representations. The present study also suggests that females have an enhanced sensitivity and emotional tuning toward companions. These findings are consistent with the view that contagious yawning reveals an emotional connection between individuals. This phenomenon, here demonstrated in monkeys, could be a building block for full-blown empathy. PMID:19889980

  2. Contagious yawning in gelada baboons as a possible expression of empathy.

    PubMed

    Palagi, E; Leone, A; Mancini, G; Ferrari, P F

    2009-11-17

    Yawn contagion in humans has been proposed to be related to our capacity for empathy. It is presently unclear whether this capacity is uniquely human or shared with other primates, especially monkeys. Here, we show that in gelada baboons (Theropithecus gelada) yawning is contagious between individuals, especially those that are socially close, i.e., the contagiousness of yawning correlated with the level of grooming contact between individuals. This correlation persisted after controlling for the effect of spatial association. Thus, emotional proximity rather than spatial proximity best predicts yawn contagion. Adult females showed precise matching of different yawning types, which suggests a mirroring mechanism that activates shared representations. The present study also suggests that females have an enhanced sensitivity and emotional tuning toward companions. These findings are consistent with the view that contagious yawning reveals an emotional connection between individuals. This phenomenon, here demonstrated in monkeys, could be a building block for full-blown empathy. PMID:19889980

  3. Feline respiratory disease complex.

    PubMed

    Cohn, Leah A

    2011-11-01

    Feline respiratory disease complex (FRDC) refers to the characteristic acute presentation of a contagious respiratory or ocular disease caused by one or multiple pathogens. Environmental and host factors impact the transmission, clinical presentation, preventive strategy, and treatment of affected cats. The FRDC is especially problematic in settings where large numbers of cats cohabit, including animal shelters, catteries, and semi-feral colonies. Although elimination of FRDC is an unrealistic goal, improved understanding can lead to strategies to minimize disease impact. PMID:22041216

  4. Yawning as a Brain Cooling Mechanism: Nasal Breathing and Forehead Cooling Diminish the Incidence of Contagious Yawning

    Microsoft Academic Search

    Andrew C. Gallup; Gordon G. Gallup Jr

    We conducted two experiments that implicate yawning as a thermoregulatory mechanism. The first experiment demonstrates that different patterns of breathing influence susceptibility to contagious yawning. When participants were not directed how to breathe or were instructed to breathe orally (inhaling and exhaling through their mouth), the incidence of contagious yawning in response to seeing videotapes of people yawning was about

  5. The use of monoclonal antibodies in the diagnosis of contagious caprine pleuropneumonia (CCPP).

    PubMed

    Thiaucourt, F; Bölske, G; Libeau, G; Le Goff, C; Lefčvre, P C

    1994-08-01

    Contagious caprine pleuropneumonia is a severe disease affecting goats in Eastern Africa and the Middle East, caused by Mycoplasma sp. type F38. Its exact geographical distribution is however not exactly known due to the lack of specificity of the available serological tests and the difficulty in cultivating M. sp. F38. A panel of monoclonal antibodies (mAbs) was produced, using crude or membrane proteins antigens from type F38 strains to immunize mice. The reactivity of the mAbs was tested by an immunobinding assay with crude mycoplasma antigens spotted on nitrocellulose filters. One hundred and twelve antigens, standardized at 0.5 mg protein/ml, were used. Mycoplasma strains were chosen among closely related species of the "mycoides cluster", M. capricolum, Group 7 of Leach, M. mycoides mycoides LC, M. mycoides mycoides SC, M. mycoides capri, as well as among species that are isolated from goat lungs, M. arginini, M. ovipneumoniae, M. putrefaciens, M. agalactiae. Out of 60 mAbs, 4 were chosen to build an identification test for mycoplasmas of the "mycoides cluster". Controls showed that accurate identification could be hampered by antigenic heterogeneity within the M. capricolum species. One mAb was used for the direct detection of M. sp. F38 antigen in pleural fluid from goats suspected of CCPP. The sensitivity of the test can be estimated at 0.5 micrograms protein/ml. Comparison with isolation results show a 74% agreement between the two methods. The same mAb was used to build a blocking ELISA. This serological test was strictly specific for CCPP. It detects antibodies in sera of naturally infected or artificially immunized animals while it remained negative with hyperimmune sera to related strains such as PG 50. Direct antigen detection and blocking ELISA are tools that may enable a better assessment of CCPP distribution. PMID:7975145

  6. Camelpox, an emerging orthopox viral disease.

    PubMed

    Balamurugan, Vinayagamurthy; Venkatesan, Gnanavel; Bhanuprakash, Veerakyathappa; Singh, Raj Kumar

    2013-12-01

    Camelpox is considered as emerging public health problem during this decade due to increased reported cases and outbreaks in camels. Camelpox is a contagious, often sporadic, and notifiable skin disease of camelids and is socio-economically significant as it incurs considerable loss in terms of morbidity, mortality, loss of weight and reduction in milk yield and confined to camel-rearing countries. The causative agent, camelpox virus (CMLV) is genetically closely related to variola virus and has gained much attention from researchers due to its recent emergence in human. The virus carrying genes responsible for host immune evasion mechanisms owing to the threat posed by potential bio-warfare agents. Although the disease can be diagnosed based on clinical features, the similar confounding skin lesions necessitate identification, detection and differentiation of the CMLV by molecular techniques. Vaccines are available in some countries and the available live attenuated vaccine provides long-lasting immunity. Further, novel highly sensitive and specific techniques would be useful in the identification of emerging and re-emerging virus, thereby therapeutic, prophylactic, preventive measures would be applied in time to curtail further spread of camelpox like other zoonotic diseases. This review provide overview of the camelpox particularly on its epidemiology, pathogenesis and biology of the disease, diagnostic approaches and control measures. PMID:24426291

  7. Feline parvovirus infection and associated diseases.

    PubMed

    Stuetzer, Bianca; Hartmann, Katrin

    2014-08-01

    Feline panleukopenia, caused by the single-stranded DNA virus feline parvovirus (FPV), is a highly contagious and often lethal disease of cats and other Felidae. FPV, but also canine parvovirus (CPV) can be isolated from both healthy and diseased cats. In Germany, CPV was detected in only approximately 10% of feline samples, but in Southeast Asia, reports estimated that up to approximately 80% of diseased cats were infected with CPV. Infection spreads rapidly, especially in cells with high mitotic activity, such as bone marrow, lymphoid tissue and intestinal crypt cells. Anorexia, vomiting, diarrhoea, neutropenia and lymphopenia are common in clinically affected cases. In utero or neonatal infection can result in cerebellar hypoplasia. Depending on the severity of clinical signs, mortality ranges from 25 to 100%. Effective vaccination and thorough disinfection are of the utmost importance in the prevention of disease transmission in multi-cat households and animal shelters. If clinical signs develop, supportive treatment should be commenced. The efficacy of feline recombinant interferon and FPV antibodies has not been clearly demonstrated. Commercially available vaccines should induce protective immunity when administered according to current guidelines. Recent studies suggest that in some kittens, maternally derived antibodies (MDA) can persist for much longer than has been previously recognised. FPV serum antibody tests are available, but protection status needs to be interpreted with caution in kittens with MDA and a negative titre in adult cats does not necessarily denote lack of protection. PMID:24923754

  8. Pathogenesis of Adamantiades-Behçet's disease

    Microsoft Academic Search

    Christos C. Zouboulis; Tobias May

    2003-01-01

    The aetiology of Adamantiades-Behçet's disease remains unknown and its pathogenesis is not fully understood. Linked intrinsic and extrinsic factors are thought to contribute to the development of the disease, which probably occurs by environmental triggering of a genetically determined disorder. Transmission is solely vertical, indicating that the disease is not contagious. Genetic factors have been investigated and a significant link

  9. 2SI2R rumor spreading model in homogeneous networks

    NASA Astrophysics Data System (ADS)

    Wang, Jiajia; Zhao, Laijun; Huang, Rongbing

    2014-11-01

    Similarities exist between the rumor spreading and the infectious disease transmission. Some researches on the disease spreading involve two or more diseases which are cross-infection propagation. Similarly, two or several kinds of rumors may spread at the same time. In this paper, we study a rumor spreading model called 2SI2R model, in which two types of rumors spread simultaneously among the crowd. Derived from mean-field equations, the dynamics of the 2SI2R rumor spreading model in homogeneous networks is elucidated. Employing the method on infectious diseases, the basic reproduction number, the stability of the disease-free equilibrium, and the final size of rumor are investigated and discussed. In the numerical simulation part, the interaction of two rumors and the impact of different parameters on the rumor spreading are discussed.

  10. [Meleda disease (Mal de Meleda): historical shifts in perception].

    PubMed

    Gjurasi?, Marija

    2010-01-01

    Nowadays, hereditary diseases are viewed through molecular mechanisms, and one of them, which keeps occurring rather frequently in medical publications, has been named after the Island of Mljet. The world first learned about mal de Meleda from a Dubrovnik physician Luka Stulli in 1826. He described it in a number of his island patients as a non-contagious hereditary skin disease, and named it mal de Meleda (a disease of Mljet). After Stulli, numerous scientists continued to investigate its aetiology and distinctive properties, introducing new scientific procedures to research the disease. The article keeps track of the way people and medicine perceived and treated mal de Meleda patients, starting from the early 19th century to the present day. It pays special attention to how the disease was perceived and described in medical literature through history. There are no reports in writing about the disease before the 19th century, but in oral tradition it was perceived as a punishment for the sins of sacrilege, sins of piracy, or even as leftovers of leprosy brought by the crusaders. We investigated if these legends have any support in preserved historical documents and to what extent they are related to real historical events and circumstances. Influenced by the booming research in microbiology, end 19th century physicians believed the disease was an isolated focus of leprosy. However, early 20th century physicians defined it as a hereditary skin disease with changes which distinguish it from other skin conditions. Genetic nature of the disease was later confirmed by molecular science. As for its geographical origin, the most recent medical research has shown that mal de Meleda is not restricted to the island of Mljet, and that it is spread worldwide, particularly in regions that, historically, were the trading routes of the Dubrovnik Republic. This implies that the mutation has spread through migration and persists only because it is not lethal and does not affect reproduction. PMID:21073245

  11. Multi-locus sequence analysis of Mycoplasma capricolum subsp. capripneumoniae for the molecular epidemiology of contagious caprine pleuropneumonia.

    PubMed

    Manso-Silván, Lucía; Dupuy, Virginie; Chu, Yuefeng; Thiaucourt, François

    2011-01-01

    Mycoplasma capricolum subsp. capripneumoniae (Mccp) is the causative agent of contagious caprine pleuropneumonia (CCPP), a devastating disease of domestic goats. The exact distribution of CCPP is not known but it is present in Africa and the Middle East and represents a significant threat to many disease-free areas including Europe. Furthermore, CCPP has been recently identified in Tajikistan and China. A typing method with an improved resolution based on Multi-Locus Sequence Analysis (MLSA) has been developed to trace new epidemics and to elucidate whether the recently identified cases in continental Asia were due to recent importation of Mccp. The H2 locus, a polymorphic region already in use as a molecular marker for Mccp evolution, was complemented with seven new loci selected according to the analysis of polymorphisms observed among the genome sequences of three Mccp strains. A total of 25 strains, including the two new strains from Asia, were analysed by MLSA resulting in the discrimination of 15 sequence types based on 53 polymorphic positions. A distance tree inferred from the concatenated sequences of the eight selected loci revealed two evolutionary lineages comprising five groups, which showed good correlation with geographic origins. The presence of a distinct Asian cluster strongly indicates that CCPP was not recently imported to continental Asia. It is more likely that the disease has been endemic in the area for a long time, as supported by historical clinical descriptions. In conclusion, this MLSA strategy constitutes a highly discriminative tool for the molecular epidemiology of CCPP. PMID:21756321

  12. Outbreaks where food workers have been implicated in the spread of foodborne disease. Part 11. Use of antiseptics and sanitizers in community settings and issues of hand hygiene compliance in health care and food industries.

    PubMed

    Todd, Ewen C D; Greig, Judy D; Michaels, Barry S; Bartleson, Charles A; Smith, Debra; Holah, John

    2010-12-01

    Hand washing with soap is a practice that has long been recognized as a major barrier to the spread of disease in food production, preparation, and service and in health care settings, including hospitals, child care centers, and elder care facilities. Many of these settings present multiple opportunities for spread of pathogens within at-risk populations, and extra vigilance must be applied. Unfortunately, hand hygiene is not always carried out effectively, and both enteric and respiratory diseases are easily spread in these environments. Where water is limited or frequent hand hygiene is required on a daily basis, such as for many patients in hospitals and astronauts in space travel, instant sanitizers or sanitary wipes are thought to be an effective way of preventing contamination and spread of organisms among coworkers and others. Most concerns regarding compliance are associated with the health care field, but the food industry also must be considered. Specific reasons for not washing hands at appropriate times are laziness, time pressure, inadequate facilities and supplies, lack of accountability, and lack of involvement by companies, managers, and workers in supporting proper hand washing. To facilitate improvements in hand hygiene, measurement of compliant and noncompliant actions is necessary before implementing any procedural changes. Training alone is not sufficient for long-lasting improvement. Multiactivity strategies also must include modification of the organization culture to encourage safe hygienic practices, motivation of employees willing to use peer pressure on noncompliant coworkers, a reward and/or penalty system, and an operational design that facilitates regular hand hygiene. PMID:21219754

  13. What is the flu? Influenza, "the flu" is a contagious respiratory infection

    E-print Network

    Virginia Tech

    What is the flu? Influenza, "the flu" is a contagious respiratory infection caused by the influenza "stomach flu" is often used inaccurately; that term refers to gastrointestinal viruses, not influenza with influenza-like illness (ILI) should stay home for at least 24 hours after their fever is gone (without

  14. The role of Mycoplasma strain F38 in contagious caprine pleuropneumonia (CCCP) in Kenya.

    PubMed

    MacOwan, K J; Minette, J E

    1977-11-01

    The results of a serological and cultural study of experimental and field cases of contagious caprine pleuropneumonia were consistent with an aetiological role for mycoplasma strain F38. This mycoplasma was isolated from 57 acute cases in 46 outbreaks of CCPP and from 87 experimental contact cases. Clinical data from experimental contact cases were assessed for comparison with field cases. PMID:595269

  15. Male yawning is more contagious than female yawning among chimpanzees (Pan troglodytes).

    PubMed

    Massen, Jorg J M; Vermunt, Dorith A; Sterck, Elisabeth H M

    2012-01-01

    Yawn contagion is not restricted to humans and has also been reported for several non-human animal species, including chimpanzees (Pan troglodytes). Contagious yawning may lead to synchronisation of behaviour. However, the function of contagious yawning is relatively understudied. In this study, we investigated the function of contagious yawning by focusing on two types of signal providers: close social associates and leaders. We provided a captive chimpanzee colony with videos of all individuals of their own group that were either yawning, or at rest. Consistent with other studies, we demonstrated that yawning is contagious for chimpanzees, yet we did not find any effect of relationship quality on yawn contagion. However, we show that yawn contagion is significantly higher when the video model is a yawning male than when the video model was a yawning female, and that this effect is most apparent among males. As males are dominant in chimpanzee societies, male signals may be more relevant to the rest of the group than female signals. Moreover, since chimpanzees form male-bonded societies, male signals are especially relevant for other males. Therefore, we suggest that the sex-differences of yawning contagion among chimpanzees reflect the function of yawning in the synchronisation of behaviour. PMID:22808234

  16. Evidence for contagious behaviors in budgerigars (Melopsittacus undulatus): an observational study of yawning and stretching.

    PubMed

    Miller, Michael L; Gallup, Andrew C; Vogel, Andrea R; Vicario, Shannon M; Clark, Anne B

    2012-03-01

    Yawning is contagious in humans and some non-human primates. If there are social functions to contagious behaviors, such as yawning, they might occur in other highly social vertebrates. To investigate this possibility, we conducted an observational study of yawning and an associated behavior, stretching, in budgerigars (Melopsittacus undulatus), a social, flock-living parrot. Flock-housed budgerigars were videotaped for 1.5h at three time-blocks during the day (early morning, afternoon and early evening), and the times of all yawns and stretches for each bird were recorded. Both yawning and stretching were temporally clumped within sessions, but were uniformly distributed across the trials of a particular time-block. This suggests that clumping was not a result of circadian patterning and that both behaviors could be contagious. There was additional evidence of contagion in stretching, which occurred in two forms - a posterior-dorsal extension of either one foot or both feet. Birds that could have observed a conspecific stretch, and that then stretched themselves within 20s, replicated the form of the earlier stretch significantly more often than expected by chance. This study provides the first detailed description of temporal patterns of yawning under social conditions in a flock-living species as well as the first support for contagious yawning and stretching in a non-primate species in a natural context. Experimental evidence will be necessary to confirm the extent of contagion in either behavior. PMID:22209955

  17. Male Yawning Is More Contagious than Female Yawning among Chimpanzees (Pan troglodytes)

    PubMed Central

    Massen, Jorg J. M.; Vermunt, Dorith A.; Sterck, Elisabeth H. M.

    2012-01-01

    Yawn contagion is not restricted to humans and has also been reported for several non-human animal species, including chimpanzees (Pan troglodytes). Contagious yawning may lead to synchronisation of behaviour. However, the function of contagious yawning is relatively understudied. In this study, we investigated the function of contagious yawning by focusing on two types of signal providers: close social associates and leaders. We provided a captive chimpanzee colony with videos of all individuals of their own group that were either yawning, or at rest. Consistent with other studies, we demonstrated that yawning is contagious for chimpanzees, yet we did not find any effect of relationship quality on yawn contagion. However, we show that yawn contagion is significantly higher when the video model is a yawning male than when the video model was a yawning female, and that this effect is most apparent among males. As males are dominant in chimpanzee societies, male signals may be more relevant to the rest of the group than female signals. Moreover, since chimpanzees form male-bonded societies, male signals are especially relevant for other males. Therefore, we suggest that the sex-differences of yawning contagion among chimpanzees reflect the function of yawning in the synchronisation of behaviour. PMID:22808234

  18. Contagious itch: what we know and what we would like to know.

    PubMed

    Schut, C; Grossman, S; Gieler, U; Kupfer, J; Yosipovitch, G

    2015-01-01

    All humans experience itch in the course of their life. Even a discussion on the topic of itch or seeing people scratch can evoke the desire to scratch. These events are coined "contagious itch" and are very common. We and others have shown that videos showing people scratching and pictures of affected skin or insects can induce itch in healthy persons and chronic itch patients. In our studies, patients with atopic dermatitis (AD) were more susceptible to visual itch cues than healthy. Also, personality traits like agreeableness and public self-consciousness were associated with induced scratching in skin patients, while neuroticism correlated with induced itch in healthy subjects. The underlying course of contagious itch is not yet fully understood. It is hypothesized that there are human mirror neurons that are active when we imitate actions and/or negative affect. Until now, there has been only limited data on the mechanisms of brain activation in contagious itch though. We have barely begun to understand the underlying physiological reactions and the triggering factors of this phenomenon. We summarize what we currently know about contagious itch and provide some suggestions what future research should focus on. PMID:25717300

  19. Contagious Flow: Antecedents and Consequences of Optimal Experience in the Classroom

    ERIC Educational Resources Information Center

    Culbertson, Satoris S.; Fullagar, Clive J.; Simmons, Mathias J.; Zhu, Mengmeng

    2015-01-01

    The current study examined undergraduate student understanding of, and interest in, course material as potential antecedents to student experiences of flow within a classroom setting. In addition, the social, informative, and contagious nature of flow were examined, as was the influence of being in flow during classroom coverage of material on…

  20. Endogeneity Bias May be Contagious DA Freedman Statistics 215 November 2007

    E-print Network

    Sekhon, Jasjeet S.

    Endogeneity Bias May be Contagious DA Freedman Statistics 215 November 2007 1) Let x and w be fixed n-vectors with mean 0. Let (i, i) be IID pairs of normal random variables, with expectation 0 biased downward by rc2 1 + 2 - r2 . (f) Show that endogeneity bias affects ^a unless r = 0. (g) Can

  1. Experimental parapoxvirus infection (contagious ecthyma) in semi-domesticated reindeer (Rangifer tarandus tarandus).

    PubMed

    Tryland, Morten; Klein, Jörn; Berger, Therese; Josefsen, Terje D; das Neves, Carlos G; Oksanen, Antti; Ĺsbakk, Kjetil

    2013-03-23

    Contagious ecthyma (contagious pustular dermatitis, orf) occurs world-wide in sheep and goats and is caused by orf virus (genus Parapoxvirus, family Poxviridae). Contagious ecthyma outbreaks have been described in semi-domesticated reindeer (Rangifer tarandus tarandus) in Sweden, Finland and Norway, occasionally with high mortality. Fourteen one-year-old reindeer were corralled in mid-April. One week after arrival, two animals received a commercial live orf virus vaccine for sheep (Scabivax(®)) on scarified skin of the medial thigh. Four weeks later, the two vaccinated and six additional animals were inoculated in scarified oral mucosa with parapoxvirus obtained from reindeer with clinical contagious ecthyma. The remaining six reindeer were kept as sentinels, sharing feed and water with the inoculated animals. A small whitish lesion appeared on the inoculation site and the labial skin-mucosa junction of three animals five days post inoculation (p.i.). Twelve days p.i., typical ecthyma lesions were visible on the inoculation site in six of eight animals, including both vaccinees. Four inoculated animals (including both vaccinees) and one sentinel seroconverted 12 days p.i., and five animals (including one sentinel) seroconverted 20 days p.i. No contagious ecthyma-like lesions were detected in the sentinels. All animals were euthanized at 26-29 days p.i. Histological examination of lesions showed proliferative dermatitis with epidermal hyperplasia, hyperkeratosis, intra-epithelial pustules and ulcers. Orf virus DNA was detected in mandibular lymph nodes, tonsils and mucosal lesions of four animals, including one sentinel, which showed that virus transmission took place. The commercial orf virus vaccine may be difficult to administer due to the need for close-cropping and its zoonotic nature, and did not indicate significant protection, although the latter has to be verified with a larger number of animals. PMID:23201244

  2. A STOCHASTIC MODEL FOR THE SPREAD OF A SEXUALLY

    E-print Network

    Reed, W.J.

    A STOCHASTIC MODEL FOR THE SPREAD OF A SEXUALLY TRANSMITTED DISEASE WHICH RESULTS IN A SCALE power-law behaviour. The implications of this for the spread of a sexually transmitted disease (STD transmitted disease (STD) is presented. To reflect varying degrees of promiscuity among individuals

  3. Mutual Feedback Between Epidemic Spreading and Information Diffusion

    E-print Network

    Zhan, Xiu-Xiu; Zhou, Ge; Zhang, Zi-Ke; Sun, Gui-Quan; Zhu, Jonathan J H

    2015-01-01

    The impact that information diffusion has on epidemic spreading has recently attracted much attention. As a disease begins to spread in the population, information about the disease is transmitted to others, which in turn has an effect on the spread of disease. In this paper, using empirical results of the propagation of H7N9 and information about the disease, we clearly show that the spreading dynamics of the two-types of processes influence each other. We build a mathematical model in which both types of spreading dynamics are described using the SIS process in order to illustrate the influence of information diffusion on epidemic spreading. Both the simulation results and the pairwise analysis reveal that information diffusion can increase the threshold of an epidemic outbreak, decrease the final fraction of infected individuals and significantly decrease the rate at which the epidemic propagates. Additionally, we find that the multi-outbreak phenomena of epidemic spreading, along with the impact of inform...

  4. Review Article: Current status of vaccines against infectious bursal disease

    Microsoft Academic Search

    Hermann Müller; Egbert Mundt; Nicolas Eterradossi; M. Rafiqul Islam

    2012-01-01

    Infectious bursal disease virus (IBDV) is the aetiological agent of the acute and highly contagious infectious bursal disease (IBD) or “Gumboro disease”. IBD is one of the economically most important diseases that affects commercially produced chickens worldwide. Along with strict hygiene management of poultry farms, vaccination programs with inactivated and live attenuated viruses have been used to prevent IBD. Live

  5. The Pathology of Fear: Disease and American Dis-ease at the Turn of the Twentieth Century 

    E-print Network

    Jung, Yeonsik

    2013-11-20

    feared” was understood and “felt to be morally, if not literally, contagious,” mirroring the political and cultural dis-ease of a society (Sontag 6). Regarded invariably as judgments on society, plagues were believed to reveal and punish moral laxity... typhus and cholera quarantines justified anti-Semitism, inequitably targeted Eastern European Jews, and the 1916 polio epidemic was, similarly, believed to have originated from Italians (Wald, Contagious 115; Humphrey 852). The strangers? supposed...

  6. Quantum Spread Spectrum Communication

    SciTech Connect

    Humble, Travis S [ORNL

    2011-01-01

    We show that communication of single-photon quantum states in a multi-user environment is improved by using spread spectrum communication techniques. We describe a framework for spreading, transmitting, despreading, and detecting single-photon spectral states that mimics conventional spread spectrum techniques. We show in the cases of inadvertent detection, unintentional interference, and multi-user management, that quantum spread spectrum communications may minimize receiver errors by managing quantum channel access.

  7. Development of an improved vaccine for contagious bovine pleuropneumonia: an African perspective on challenges and proposed actions

    PubMed Central

    2013-01-01

    Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides (Mmm) is an economically very important cattle disease in sub-Saharan Africa. CBPP impacts animal health and poverty of livestock-dependent people through decreased animal productivity, reduced food supply, and the cost of control measures. CBPP is a barrier to trade in many African countries and this reduces the value of livestock and the income of many value chain stakeholders. The presence of CBPP also poses a constant threat to CBPP-free countries and creates costs in terms of the measures necessary to ensure the exclusion of disease. This opinion focuses on the biomedical research needed to foster the development of better control measures for CBPP. We suggest that different vaccine development approaches are followed in parallel. Basic immunology studies and systematic OMICs studies will be necessary in order to identify the protective arms of immunity and to shed more light on the pathogenicity mechanisms in CBPP. Moreover a robust challenge model and a close collaboration with African research units will be crucial to foster and implement a new vaccine for the progressive control of this cattle plague. PMID:24359340

  8. Development of an improved vaccine for contagious bovine pleuropneumonia: an African perspective on challenges and proposed actions.

    PubMed

    Jores, Joerg; Mariner, Jeffrey C; Naessens, Jan

    2013-01-01

    Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides (Mmm) is an economically very important cattle disease in sub-Saharan Africa. CBPP impacts animal health and poverty of livestock-dependent people through decreased animal productivity, reduced food supply, and the cost of control measures. CBPP is a barrier to trade in many African countries and this reduces the value of livestock and the income of many value chain stakeholders. The presence of CBPP also poses a constant threat to CBPP-free countries and creates costs in terms of the measures necessary to ensure the exclusion of disease. This opinion focuses on the biomedical research needed to foster the development of better control measures for CBPP. We suggest that different vaccine development approaches are followed in parallel. Basic immunology studies and systematic OMICs studies will be necessary in order to identify the protective arms of immunity and to shed more light on the pathogenicity mechanisms in CBPP. Moreover a robust challenge model and a close collaboration with African research units will be crucial to foster and implement a new vaccine for the progressive control of this cattle plague. PMID:24359340

  9. Narrowband spread spectrum systems

    Microsoft Academic Search

    K. H. Annecke; M. Ottka

    1984-01-01

    The available military radio frequency bands are covered very densely by the already existing conventional systems and therefore the application of bandwidth widening procedures as antijam measures will be allowed only with small spreading factors within these RF-bands. The problems arising from the random code selection for spread spectrum systems with small spreading factors are discussed. The calculations show the

  10. Pathways of Lateral Spreading

    Microsoft Academic Search

    U. Jacobi; S. Schanzer; H.-J. Weigmann; A. Patzelt; T. Vergou; W. Sterry; J. Lademann

    2011-01-01

    In the case of topically applied substances, usually both lateral spreading and competitive penetration into the skin occur in parallel. In the present study, the pathways of lateral spreading were studied quantitatively and visually. The local distribution and lateral spreading of the UV filter substance butyl methoxydibenzoylmethane applied in an o\\/w emulsion was studied on the forearm and the back.

  11. Sero-prevalence of Contagious Bovine Pleuropneumonia (CBPP) in bulls originated from Borena pastoral area of Southern Ethiopia.

    PubMed

    Alemayehu, Gezahegn; Leta, Samson; Hailu, Berhanu

    2015-06-01

    Contagious Bovine Pleuropneumonia (CBPP) is a highly infectious cattle disease, which is widespread in pastoral areas of Africa, and it imposes a major problem on Ethiopian livestock export market. Cross-sectional study was conducted in 2011 on bulls originated from Borena pastoral area to determine seroprevalence of CBPP. Forty batches of bulls containing 38,187 Borana bulls were tested using c-ELISA. Of the total 40 batches tested for the presence of antibodies, 25 (62.5 %) of them contained at least one seropositive bull. From the total of 38,187 bulls tested, 150 (0.4 %) bulls were positive. The number of seropositive animals increases as the herd size increases (P?1000, and the difference was found statistically significant (P?disease is decreasing progressively in Borena pastoral area, this might be associated with the ongoing mass vaccination campaign against economically important livestock diseases in pastoral areas. The decrease in the prevalence of CBPP offered a great opportunity to livestock producers and live animal and meat exporters by improving the demand of Ethiopian livestock on international market. Regular reintroduction of infected cattle from neighboring countries or herds where the disease remains endemic may change the disease dynamics again. Therefore, mass blanket vaccinations coupled with prompt diagnosis, isolation and stamping out of the outbreaks, intensive surveillance, followed by strict cattle movement control should be implemented by concerned parties. PMID:25863957

  12. Host-induced epidemic spread of the cholera bacterium

    Microsoft Academic Search

    D. Scott Merrell; Susan M. Butler; Firdausi Qadri; Nadia A. Dolganov; Ahsfaqul Alam; Mitchell B. Cohen; Stephen B. Calderwood; Gary K. Schoolnik; Andrew Camilli

    2002-01-01

    The factors that enhance the transmission of pathogens during epidemic spread are ill defined. Water-borne spread of the diarrhoeal disease cholera occurs rapidly in nature, whereas infection of human volunteers with bacteria grown in vitro is difficult in the absence of stomach acid buffering. It is unclear, however, whether stomach acidity is a principal factor contributing to epidemic spread. Here

  13. Differential induction and spread of tau pathology in young PS19 tau transgenic mice following intracerebral injections of pathological tau from Alzheimer’s disease or corticobasal degeneration brains

    PubMed Central

    Boluda, Susana; Iba, Michiyo; Zhang, Bin; Raible, Kevin M.; Lee, Virginia M-Y.; Trojanowski, John Q.

    2015-01-01

    Filamentous tau pathologies are hallmark lesions of several neurodegenerative tauopathies including Alzheimer’s disease (AD) and corticobasal degeneration (CBD) which show cell type-specific and topographically distinct tau inclusions. Growing evidence supports templated transmission of tauopathies through functionally interconnected neuroanatomical pathways suggesting that different self-propagating strains of pathological tau could account for the diverse manifestations of neurodegenerative tauopathies. Here, we describe the rapid and distinct cell type-specific spread of pathological tau following intracerebral injections of CBD or AD brain extracts enriched in pathological tau (designated CBD-Tau and AD-Tau, respectively) in young human mutant P301S tau transgenic (Tg) mice (line PS19) ~6–9 months before they show onset of mutant tau transgene-induced tau pathology. At 1 month post-injection of CBD-Tau, tau inclusions developed predominantly in oligodendrocytes of the fimbria and white matter near the injection sites with infrequent intraneuronal tau aggregates. In contrast, injections of AD-Tau in young PS19 mice induced tau pathology predominantly in neuronal perikarya with little or no oligodendrocyte involvement 1 month post-injection. With longer post-injection survival intervals of up to 6 months, CBD-Tau- and AD-Tau-induced tau pathology spread to different brain regions distant from the injection sites while maintaining the cell type-specific pattern noted above. Finally, CA3 neuron loss was detected 3 months post-injection of AD-Tau but not CBD-Tau. Thus, AD-Tau and CBD-Tau represent specific pathological tau strains that spread differentially and may underlie distinct clinical and pathological features of these two tauopathies. Hence, these strains could become targets to develop disease-modifying therapies for CBD and AD. PMID:25534024

  14. Infectious Disease Modeling of Social Contagion in Networks

    PubMed Central

    Hill, Alison L.; Rand, David G.; Nowak, Martin A.; Christakis, Nicholas A.

    2010-01-01

    Many behavioral phenomena have been found to spread interpersonally through social networks, in a manner similar to infectious diseases. An important difference between social contagion and traditional infectious diseases, however, is that behavioral phenomena can be acquired by non-social mechanisms as well as through social transmission. We introduce a novel theoretical framework for studying these phenomena (the SISa model) by adapting a classic disease model to include the possibility for ‘automatic’ (or ‘spontaneous’) non-social infection. We provide an example of the use of this framework by examining the spread of obesity in the Framingham Heart Study Network. The interaction assumptions of the model are validated using longitudinal network transmission data. We find that the current rate of becoming obese is 2 per year and increases by 0.5 percentage points for each obese social contact. The rate of recovering from obesity is 4 per year, and does not depend on the number of non-obese contacts. The model predicts a long-term obesity prevalence of approximately 42, and can be used to evaluate the effect of different interventions on steady-state obesity. Model predictions quantitatively reproduce the actual historical time course for the prevalence of obesity. We find that since the 1970s, the rate of recovery from obesity has remained relatively constant, while the rates of both spontaneous infection and transmission have steadily increased over time. This suggests that the obesity epidemic may be driven by increasing rates of becoming obese, both spontaneously and transmissively, rather than by decreasing rates of losing weight. A key feature of the SISa model is its ability to characterize the relative importance of social transmission by quantitatively comparing rates of spontaneous versus contagious infection. It provides a theoretical framework for studying the interpersonal spread of any state that may also arise spontaneously, such as emotions, behaviors, health states, ideas or diseases with reservoirs. PMID:21079667

  15. Whole Genome Association Study of Johne's Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine Paratuberculosis, commonly referred to as Johne's disease, is a contagious bacterial disease estimated to be present in over 65% of US dairy herds and results in annual losses in the hundreds of millions of US dollars. Mycobacterium avium subspecies paratuberculosis (MAP) is the bacteria resp...

  16. Transcriptional profiling of bovine Johne's Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Johne's Disease is a chronic, contagious disease prevalent in ruminants. The animal is infected early in life by the bacteria Mycobacterium avium subsp. paratuberculosis (MAP). The characteristic symptoms of rapid weight loss and diarrhea may not appear for years after infection. We investigated t...

  17. RNAi-based strategy for Asian citrus psyllid (Diaphorina citri) Control: A method to reduce the spread of citrus greening disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus greening disease is a serious bacterial disease of citrus worldwide and is vectored by the Asian citrus pysllid (Diaphorina Citri). The only effective control strategy includes vigorous control of the psyllid, primarily through heavy reliance on pesticides. As a more sustainable and environm...

  18. Maximum linkage space-time permutation scan statistics for disease outbreak detection

    PubMed Central

    2014-01-01

    Background In disease surveillance, the prospective space-time permutation scan statistic is commonly used for the early detection of disease outbreaks. The scanning window that defines potential clusters of diseases is cylindrical in shape, which does not allow incorporating into the cluster shape potential factors that can contribute to the spread of the disease, such as information about roads, landscape, among others. Furthermore, the cylinder scanning window assumes that the spatial extent of the cluster does not change in time. Alternatively, a dynamic space-time cluster may indicate the potential spread of the disease through time. For instance, the cluster may decrease over time indicating that the spread of the disease is vanishing. Methods This paper proposes two irregularly shaped space-time permutation scan statistics. The cluster geometry is dynamically created using a graph structure. The graph can be created to include nearest-neighbor structures, geographical adjacency information or any relevant prior information regarding the contagious behavior of the event under surveillance. Results The new methods are illustrated using influenza cases in three New England states, and compared with the cylindrical version. A simulation study is provided to investigate some properties of the proposed arbitrary cluster detection techniques. Conclusion We have successfully developed two new space-time permutation scan statistics methods with irregular shapes and improved computational performance. The results demonstrate the potential of these methods to quickly detect disease outbreaks with irregular geometries. Future work aims at performing intensive simulation studies to evaluate the proposed methods using different scenarios, number of cases, and graph structures. PMID:24916839

  19. [The contagious behavior model on the basis of rat drinking behavior].

    PubMed

    Ivanov, D G; Semenov, A N; Krupina, N A

    2014-01-01

    In work, the attempt of contagious behavior modeling on the basis of rat drinking behavior was made. Rats' behavior was observed in home cage with two bottles. The rat without drinking motivation (viewer) was placed in the cage for adaptation. The rat-demonstrator was placed into the same cage 3 minutes later. If the viewer was tested with drink-motivated demonstrator, it had less latency of approach to bottles, higher frequency of approaches and increased drinking behavior time than the rat tested with unmotivated demonstrator or the rat tested without demonstrator. The intragastric infusion of coffee increased frequency of approaches to demonstrated bottle. Phenazepam intragastric injection decreased frequency of approaches and drinking behavior time at demonstrated bottle. The results suggest that drugs may affect rat contagious behavior based on drinking behavior. PMID:25975147

  20. Cat scratch disease

    MedlinePLUS

    ... scratch disease is caused by Bartonella henselae . The disease is spread through contact with an infected cat (a bite or scratch). It also can be spread through contact with cat saliva on broken skin or mucosal surfaces like those ...

  1. Auditory contagious yawning in domestic dogs (Canis familiaris): first evidence for social modulation.

    PubMed

    Silva, Karine; Bessa, Joana; de Sousa, Liliana

    2012-07-01

    Dogs' capacity to 'catch' human yawns has recently attracted the attention of researchers in the field of animal cognition. Following recent studies suggesting that contagion yawning in humans, and some other primates, is empathy-related, some authors have considered the possibility that the same mechanism may underlie contagious yawning in dogs. To date, however, no positive evidence has been found, and more parsimonious hypotheses have been put forward. The present study explored the 'contagion-only' hypothesis by testing whether the mere sound of a human yawn can be sufficient to elicit yawning in dogs, in a way that is unaffected by social-emotional factors. Unexpectedly, results showed an interesting interplay between contagion and social effects. Not only were dogs found to catch human yawns, but they were also found to yawn more at familiar than unfamiliar yawns. Although not allowing for conclusive inferences about the mechanisms underlying contagious yawning in dogs, this study provides first data that renders plausible empathy-based, emotionally connected, contagious yawning in these animals. PMID:22526686

  2. Diagnosis of contagious caprine pleuropneumonia by detection and identification of Mycoplasma capricolum subsp. capripneumoniae by PCR and restriction enzyme analysis.

    PubMed

    Bölske, G; Mattsson, J G; Bascuńana, C R; Bergström, K; Wesonga, H; Johansson, K E

    1996-04-01

    Contagious caprine pleuropneumonia (CCPP), one of the most serious and dramatic diseases of goats, is caused by Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae). This organism is very difficult to isolate and to correctly identify. In a previous report we described a method for the rapid detection and identification of M. capripneumoniae. This method is based on a PCR system by which a segment of the 16S rRNA gene from all mycoplasmas of the M. mycoides cluster can be amplified. The PCR product is then analyzed by restriction enzyme cleavage for the identification of M. capripneumoniae DNA. This system has now been further evaluated with respect to specificity and diagnostic efficacy for the identification and direct detection of the organism in clinical material. Identification by restriction enzyme analysis of amplified DNA from mycoplasmas of the M. mycoides cluster was verified for 55 strains, among which were 15 strains of M. capripneumoniae. The PCR was applied to clinical samples from the nose, ear, pharynx, pleural fluid, and lung tissue containing M. capripneumoniae or other mycoplasmas. As expected, mycoplasmas belonging to the M. mycoides cluster could be detected by the PCR. Restriction enzyme analysis of the PCR products could then be applied for the identification of M. capripneumoniae. Clinical samples and cultures containing M. capripneumoniae were dried on filter paper, to try an easier sample transport method, and were tested by PCR. M. capripneumoniae DNA could be detected in the dried specimens, but the sensitivity of the PCR test was reduced. PMID:8815084

  3. Spread spectrum goes commercial

    Microsoft Academic Search

    D. L. Schilling; R. L. Pickholtz; L. B. Milstein

    1990-01-01

    The use of spread-spectrum techniques to achieve more efficient utilization of available frequency spectra is examined. The two main spread-spectrum techniques, direct sequence and frequency hopping, are explained. In frequency hopping, the transmitter repeatedly changes (hops) the carrier frequency from one frequency to another. Direct-sequence transmission spreads the spectrum not by periodically changing the frequency but by modulating the original

  4. Novel antiviral therapeutics to control foot-and-mouth disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. Vaccines require approximately 7 days to induce protection, thus prior to this time vaccinated animals are still susceptible to the disease. Our group has previously shown that swine inoculated with 1x10...

  5. Evolutionary History of Contagious Bovine Pleuropneumonia Using Next Generation Sequencing of Mycoplasma mycoides Subsp. mycoides “Small Colony”

    PubMed Central

    Dupuy, Virginie; Manso-Silván, Lucía; Barbe, Valérie; Thebault, Patricia; Dordet-Frisoni, Emilie; Citti, Christine; Poumarat, François; Blanchard, Alain; Breton, Marc; Sirand-Pugnet, Pascal; Thiaucourt, François

    2012-01-01

    Mycoplasma mycoides subsp. mycoides “Small Colony” (MmmSC) is responsible for contagious bovine pleuropneumonia (CBPP) in bovidae, a notifiable disease to the World Organization for Animal Health (OIE). Although its origin is not documented, the disease was known in Europe in 1773. It reached nearly world-wide distribution in the 19th century through the cattle trade and was eradicated from most continents by stamping-out policies. During the 20th century it persisted in Africa, and it reappeared sporadically in Southern Europe. Yet, classical epidemiology studies failed to explain the re-occurrence of the disease in Europe in the 1990s. The objectives of this study were to obtain a precise phylogeny of this pathogen, reconstruct its evolutionary history, estimate the date of its emergence, and determine the origin of the most recent European outbreaks. A large-scale genomic approach based on next-generation sequencing technologies was applied to construct a robust phylogeny of this extremely monomorphic pathogen by using 20 representative strains of various geographical origins. Sixty two polymorphic genes of the MmmSC core genome were selected, representing 83601 bp in total and resulting in 139 SNPs within the 20 strains. A robust phylogeny was obtained that identified a lineage specific to European strains; African strains were scattered in various branches. Bayesian analysis allowed dating the most recent common ancestor for MmmSC around 1700. The strains circulating in Sub-Saharan Africa today, however, were shown to descend from a strain that existed around 1810. MmmSC emerged recently, about 300 years ago, and was most probably exported from Europe to other continents, including Africa, during the 19th century. Its diversity is now greater in Africa, where CBPP is enzootic, than in Europe, where outbreaks occurred sporadically until 1999 and where CBPP may now be considered eradicated unless MmmSC remains undetected. PMID:23071648

  6. The survival of foot-and-mouth disease virus in raw and pasteurized milk and milk products.

    PubMed

    Tomasula, P M; Konstance, R P

    2004-04-01

    The Foot-and-Mouth Disease virus (FMDV) is not a public health threat, but it is highly contagious to cloven-footed animals. The virus is shed into milk up to 33 h before there are apparent signs of the disease in dairy cows, and, in extreme cases, signs of disease may not appear for up to 14 d. During this time, raw milk can serve as a vector for spread of the disease both at the farm and during transport to the processing plant by milk tanker. Raw milk and milk products fed to animals have the potential to cause infection, but the potential for pasteurized milk products to cause infection is largely unknown. Current minimum pasteurization standards may not be adequate to eliminate FMDV in milk completely. The purpose of this paper is to assess the literature on the thermal resistance of FMDV in milk and milk products, to identify the risks associated with ingestion of pasteurized products by animals, and to lay a strategy to prevent the spread of FMDV from contaminated milk. PMID:15259248

  7. Chagas Disease

    MedlinePLUS

    Chagas disease is caused by a parasite. It is common in Latin America but not in the United States. ... nose, the bite wound or a cut. The disease can also spread through contaminated food, a blood ...

  8. Legionnaires' Disease

    MedlinePLUS

    Legionnaires' disease is a type of pneumonia caused by bacteria. You usually get it by breathing in mist from ... spread from person to person. Symptoms of Legionnaires' disease include high fever, chills, a cough, and sometimes ...

  9. Fifth disease

    MedlinePLUS

    Parvovirus B19; Erythema infectiosum; Slapped cheek rash ... Fifth disease is caused by human parvovirus B19. It often affects preschoolers or school-age children during the spring. The disease spreads through the fluids in the nose and ...

  10. Socio-economic factors influencing the spread of drinking water diseases in rural Africa: case study of Bondo sub-county, Kenya.

    PubMed

    Rodrigues, Anthony Joachim; Oyoo, Wandiga Shem; Odundo, Francis O; Wambu, Enos W

    2015-06-01

    Socio-economic and medical information on Bondo sub-county community was studied to help establish the relationship between the water quality challenges, community health and water rights conditions. Health challenges have been linked to water quality and household income. A total of 1,510 households/respondents were studied by means of a questionnaire. About 69% of the households have no access to treated water. Although 92% of the respondents appear to be aware that treatment of water prevents waterborne diseases, the lowest income group and children share a high burden of waterborne diseases requiring hospitalization and causing mortality. Open defecation (12.3%) in these study areas contributes to a high incidence of waterborne diseases. The community's constitutional rights to quality water in adequate quantities are greatly infringed. The source of low-quality water is not a significant determinant of waterborne disease. The differences in poverty level in the sub-county are statistically insignificant and contribute less than other factors. Increased investment in water provision across regions, improved sanitation and availability of affordable point-of-use water purification systems will have major positive impacts on the health and economic well-being of the community. PMID:26042981

  11. Accept pour publication dans Journal of Wildlife Diseases le 2 Juillet 2008 1 IS LEPROSY SPREADING AMONG NINE-BANDED ARMADILLOS IN THE

    E-print Network

    Paris-Sud XI, Université de

    AMONG NINE-BANDED ARMADILLOS IN THE SOUTHEASTERN UNITED STATES? W. J. Loughry1,6 , Richard W. Truman2.---LEPROSY IN ARMADILLOS halsde-00360416,version1-11Feb2009 Author manuscript, published in "Journal of Wildlife Diseases 2008 2 ABSTRACT: In the United States, nine-banded armadillo (Dasypus novemcinctus) populations

  12. Language-Spread Policy.

    ERIC Educational Resources Information Center

    Ammon, Ulrich

    1997-01-01

    Language-spread policy (LSP) is policy promulgated by groups seeking to spread their languages to speakers or communicative domains. LSP can be internal or external, overt or disguised, and related in different ways to national policy. Intent may be to increase native-language advantage in international communication, disseminate ideology, create…

  13. Effect of Bactericides on Population Sizes and Spread of Clavibacter michiganensis subsp. michiganensis on Tomatoes in the Greenhouse and on Disease Development and Crop Yield in the Field.

    PubMed

    Hausbeck, M K; Bell, J; Medina-Mora, C; Podolsky, R; Fulbright, D W

    2000-01-01

    ABSTRACT Chemical applications, with the exception of mancozeb, reduced population sizes and spread of Clavibacter michiganensis subsp. michiganensis among tomato seedlings in the greenhouse and impacted subsequent plant development and yield in the field. While applications of copper hydroxide, copper hydroxide/mancozeb, copper hydroxide/mancozeb (premixed 12 h before spraying), streptomycin, and streptomycin/copper hydroxide to seedlings in the greenhouse did not differ significantly from the inoculated control, the trend was for these treatments to increase the survival of inoculated transplants in the field in comparison to the inoculated control. In the field, inoculated controls produced yields that were 63% (1995) and 51% (1996) of those produced by uninoculated controls. In both years, with the exception of mancozeb in 1995, all treatments resulted in yields similar to those obtained with the uninoculated control. Plant survival and yield in the field were severely affected when transplants had a pathogen population of >/= x 10(8) CFU/g of tissue. All treatments, with the exception of mancozeb, limited C. michiganensis subsp. michiganensis populations to <5.0 x 10(5). None of the treatments significantly reduced the incidence of fruit spotting compared with that of the inoculated control. PMID:18944570

  14. First isolation of Mycoplasma capricolum subsp. capricolum, one of the causal agents of caprine contagious agalactia, on the island of Lanzarote (Spain).

    PubMed

    De la Fe, C; Gutiérrez, A; Poveda, J B; Assunçăo, P; Ramírez, A S; Fabelo, F

    2007-03-01

    During an unusually long period of bad weather, several outbreaks of caprine contagious agalactia (CCA) were reported in a number of flocks on the island of Lanzarote (Canary Islands, Spain). Clinical and subclinical mastitis in lactating goats and some cases of arthritis and pneumonia in kids were observed in the affected flocks. Mycoplasma capricolum subsp. capricolum was isolated as the main causal agent of the outbreaks, associated with M. mycoides subsp. mycoides "large colony type" (Mmm LC) in two flocks. This is the first report of an isolation of M. capricolum subsp. capricolum on the island of Lanzarote. The finding is of epidemiological importance and could complicate plans to control the disease. The significance of this mycoplasma species in association with CCA must now be studied in detail. PMID:16324858

  15. [Wide spread inflammation of the parotid glands (mumps): underestimated disease. I. Epidemiology of the mumps and its medical meaning in Poland].

    PubMed

    Ga?azka, A; Kraigher, A; Robertson, S E

    1998-01-01

    Mumps is commonly considered a "mild" infectious disease in children because death due to mumps is very rare. However, mumps causes a high rate of complications in young adults, and its burden should not be underestimated. Before the introduction of vaccine, mumps was a common infectious disease with high incidence rates which exceeded 100 per 100,000 population in most countries. Poland continues to belong to the group of countries, which do not use mumps vaccine. In Poland, the number of reported mumps cases per year ranges from 40,000 to 220,000, yielding an annual incidence rates of 110 and 570 per 100,000 population. It is estimated that each year in Poland, mumps causes 1000 cases of aseptic meningitis (range 400 to 2,200), 100 cases of encephalitis, 250 to 1375 cases of epidymo-orchitis in post-pubertal men, 50-275 cases of oophoritis in women. The age distribution of mumps cases is characteristic for a country that does not use mumps vaccine. For more that 20 years, the highest mumps incidence has occurred in children aged 5-9 years. In many countries the number of reported cases has declined significantly following the introduction of mumps vaccine, and in several countries the incidence has fallen to less than 1 per 100,000 population. Several countries using mumps vaccine have reported a shift in the age distribution of mumps cases, with an increased incidence in older children and young adults. Countries with high levels of coverage with measles-mumps-rubella (MMR) vaccine have nearly eliminated encephalitis associated with these diseases. A few countries using mumps vaccine have experienced relative resurgence of the disease, either due to incomplete vaccine coverage of certain age groups (USA) or problems with the long-term immunogenicity of mumps vaccine based on the Rubini strain (Portugal, Switzerland). PMID:10321083

  16. The skin ulceration disease in cultivated juveniles of Holothuria scabra (Holothuroidea, Echinodermata)

    Microsoft Academic Search

    P. Becker; D. Gillan; D. Lanterbecq; M. Jangoux; R. Rasolofonirina; J. Rakotovao; I. Eeckhaut

    2004-01-01

    It is frequently reported that cultivated holothuroids can suffer from a disease affecting their integument. We report here on a disease of juvenile Holothuria scabra, the widely marketed edible sea cucumber, reared in the Aqua-Lab hatchery of Toliara, Madagascar. This disease, which has been called skin ulceration disease, is very contagious and results from a severe bacterial infection that causes

  17. Review of Newcastle disease virus with particular references to immunity and vaccination

    Microsoft Academic Search

    S. O. Al-Garib; A. L. J. Gielkens; E. Gruys; G. Koch

    2003-01-01

    Newcastle disease (ND) is a highly contagious disease. The present paper deals with classification of ND virus (NDV), clinical signs and pathology, virus strain classification and molecular backgrounds for the pathogenicity. Major emphasis is reviewing immunity and vaccination. Clinical forms of the disease vary depending on many factors, but mainly on the virulence of Newcastle disease virus (NDV) strains. Virulent

  18. What Is Hodgkin Disease?

    MedlinePLUS

    ... the key statistics about Hodgkin disease? What is Hodgkin disease? Hodgkin disease (Hodgkin lymphoma) is a type of ... also have lymphoid tissue. Start and spread of Hodgkin disease Because lymphoid tissue is in many parts of ...

  19. Sea Floor Spreading I

    NSDL National Science Digital Library

    Activity and Starting Point page by R.M. MacKay. Clark College, Physics and Meteorology.

    In this introductory Excel tutorial (Activity I) students use Excel to explore the geodynamics model equation for ocean depth around a sea-floor spreading center. For students with no prior Excel experience.

  20. Tan F. Wong: Spread Spectrum & CDMA 2. Intro. Spread Spectrum Introduction to Spread Spectrum

    E-print Network

    Wong, Tan F.

    Tan F. Wong: Spread Spectrum & CDMA 2. Intro. Spread Spectrum Chapter 2 Introduction to Spread Spectrum Communications As discussed in Chapter 0, a spread spectrum modulation produces a transmitted spectrum much wider than the minimum bandwidth required. There are many ways to generate spread spectrum

  1. Prevalence, risk factors and vaccination efficacy of contagious ovine ecthyma (orf) in England.

    PubMed

    Onyango, J; Mata, F; McCormick, W; Chapman, S

    2014-10-01

    Orf is a viral disease found in English sheep flocks which can cause economic losses. It is a zoonosis with little epidemiological research available in the UK. In 2012, 3000 questionnaires were sent to English sheep farms in order to investigate the prevalence of orf, determine vaccination efficacy and to identify some of the potential risk factors. The usable response rate was 25.4 per cent. The usable farms (N=762 in the years 2011 and 2012) were used to model the percentage of animals affected on the farm, and the probability of a farm being found with the disease. The disease prevalence (DP) was standardised for the year and calculated as 1.88 per cent for ewes and 19.53 per cent for lambs. The disease risk ratio (RR) for the use of the vaccine was calculated as 2.04 for ewes and 0.75 for lambs, and therefore, the study found that lamb vaccination was beneficial (RR <1). Weed infestation and an increased number of orphan lambs were associated with increased cases of orf. We conclude that the DP in ewes and lambs affect each other, though the impact is higher for lambs in the presence of increasing prevalence in ewes. A short lambing season lowers the probability of a farm experiencing cases of orf. Vaccination was effective in lambs but not in ewes, though lambs benefitted when ewes were vaccinated (reduced orf prevalence in lambs born from vaccinated ewes), probably because any unvaccinated ewes may have been carriers that could spread the virus to the new-born lambs. PMID:24996900

  2. Characterization of Strains of Mycoplasma mycoides subsp. mycoides Small Colony Type Isolated from Recent Outbreaks of Contagious Bovine Pleuropneumonia in Botswana and Tanzania: Evidence for a New Biotype

    PubMed Central

    March, John B.; Clark, Jason; Brodlie, Malcolm

    2000-01-01

    Four strains of Mycoplasma mycoides subsp. mycoides small colony type (MmmSC) isolated from recent outbreaks of contagious bovine pleuropneumonia (CBPP) in Africa have been investigated. One Botswanan strain, M375, displayed numerous and significant phenotypic differences from both contemporary field isolates and older field and vaccine strains (African, Australian, and European strains dating back to 1936). Differences include altered morphology, reduced capsular polysaccharide production, high sensitivity to MmmSC rabbit hyperimmune antisera in vitro, and unique polymorphisms following immunoblotting. While insertion sequence analysis using IS1634 clearly indicates a close evolutionary relationship to west African strains, hybridization with IS1296 shows the absence of a band present in all other strains of MmmSC examined. The data suggest that a deletion has occurred in strain M375, which may explain its altered phenotype, including poor growth in vitro and a relative inability to cause septicemia in mice. These characteristics are also exhibited by Mycoplasma capricolum subsp. capripneumoniae (causal agent of contagious caprine pleuropneumonia [CCPP]), against which M375 antiserum exhibited some activity in vitro (unique among the various MmmSC antisera tested). These findings may have evolutionary implications, since CCPP is believed to be lung specific and without a septicemic phase (unlike CBPP). Since M375 was isolated from a clinical case of CBPP, this novel biotype may be fairly widespread but not normally isolated due to difficulty of culture and/or a potentially altered disease syndrome. Bovine convalescent antisera (obtained from contemporary naturally infected cattle in Botswana) were active against strain M375 in an in vitro growth inhibition test but not against any other strains of MmmSC tested. There exists the possibility therefore, that strain M375 may possess a set of protective antigens different from those of other strains of MmmSC (including vaccine strains). These findings have implications for the control of the current CBPP epidemic in Africa. PMID:10747118

  3. Characterization of strains of Mycoplasma mycoides subsp. mycoides small colony type isolated from recent outbreaks of contagious bovine pleuropneumonia in Botswana and Tanzania: evidence for a new biotype.

    PubMed

    March, J B; Clark, J; Brodlie, M

    2000-04-01

    Four strains of Mycoplasma mycoides subsp. mycoides small colony type (MmmSC) isolated from recent outbreaks of contagious bovine pleuropneumonia (CBPP) in Africa have been investigated. One Botswanan strain, M375, displayed numerous and significant phenotypic differences from both contemporary field isolates and older field and vaccine strains (African, Australian, and European strains dating back to 1936). Differences include altered morphology, reduced capsular polysaccharide production, high sensitivity to MmmSC rabbit hyperimmune antisera in vitro, and unique polymorphisms following immunoblotting. While insertion sequence analysis using IS1634 clearly indicates a close evolutionary relationship to west African strains, hybridization with IS1296 shows the absence of a band present in all other strains of MmmSC examined. The data suggest that a deletion has occurred in strain M375, which may explain its altered phenotype, including poor growth in vitro and a relative inability to cause septicemia in mice. These characteristics are also exhibited by Mycoplasma capricolum subsp. capripneumoniae (causal agent of contagious caprine pleuropneumonia [CCPP]), against which M375 antiserum exhibited some activity in vitro (unique among the various MmmSC antisera tested). These findings may have evolutionary implications, since CCPP is believed to be lung specific and without a septicemic phase (unlike CBPP). Since M375 was isolated from a clinical case of CBPP, this novel biotype may be fairly widespread but not normally isolated due to difficulty of culture and/or a potentially altered disease syndrome. Bovine convalescent antisera (obtained from contemporary naturally infected cattle in Botswana) were active against strain M375 in an in vitro growth inhibition test but not against any other strains of MmmSC tested. There exists the possibility therefore, that strain M375 may possess a set of protective antigens different from those of other strains of MmmSC (including vaccine strains). These findings have implications for the control of the current CBPP epidemic in Africa. PMID:10747118

  4. Contagious Fire? An Empirical Assessment of the Problem of Multi-Shooter, Multi-Shot Deadly Force Incidents in Police Work

    ERIC Educational Resources Information Center

    White, Michael D.; Klinger, David

    2012-01-01

    Recent police shootings in which multiple officers fired numerous rounds at suspects have led some observers to assert that such situations involve "contagious fire," where an initial officer's shots launch a cascade of gunfire from other officers present. Although there is anecdotal recognition of the contagious fire phenomenon among police and…

  5. Mirror neuron activity during contagious yawning--an fMRI study.

    PubMed

    Haker, Helene; Kawohl, Wolfram; Herwig, Uwe; Rössler, Wulf

    2013-03-01

    Yawning is contagious. However, little research has been done to elucidate the neuronal representation of this phenomenon. Our study objective was to test the hypothesis that the human mirror neuron system (MNS) is activated by visually perceived yawning. We used functional magnetic resonance imaging to assess brain activity during contagious yawning (CY). Signal-dependent changes in blood oxygen levels were compared when subjects viewed videotapes of yawning faces as opposed to faces with a neutral expression. In response to yawning, subjects showed unilateral activation of their Brodmann's area 9 (BA 9) portion of the right inferior frontal gyrus, a region of the MNS. In this way, two individuals could share physiological and associated emotional states based on perceived motor patterns. This is one component of empathy (motor empathy) that underlies the development of cognitive empathy. The BA 9 is reportedly active in tasks requiring mentalizing abilities. Our results emphasize the connection between the MNS and higher cognitive empathic functions, including mentalizing. We conclude that CY is based on a functional substrate of empathy. PMID:22772979

  6. Asymmetrically interacting spreading dynamics on complex layered networks

    PubMed Central

    Wang, Wei; Tang, Ming; Yang, Hui; Younghae Do; Lai, Ying-Cheng; Lee, GyuWon

    2014-01-01

    The spread of disease through a physical-contact network and the spread of information about the disease on a communication network are two intimately related dynamical processes. We investigate the asymmetrical interplay between the two types of spreading dynamics, each occurring on its own layer, by focusing on the two fundamental quantities underlying any spreading process: epidemic threshold and the final infection ratio. We find that an epidemic outbreak on the contact layer can induce an outbreak on the communication layer, and information spreading can effectively raise the epidemic threshold. When structural correlation exists between the two layers, the information threshold remains unchanged but the epidemic threshold can be enhanced, making the contact layer more resilient to epidemic outbreak. We develop a physical theory to understand the intricate interplay between the two types of spreading dynamics. PMID:24872257

  7. FREQUENCY HOPPING SPREAD SPECTRUM DIRECT SEQUENCE SPREAD SPECTRUM

    E-print Network

    Westall, James M.

    FREQUENCY HOPPING SPREAD SPECTRUM VS. DIRECT SEQUENCE SPREAD SPECTRUM RAYLINK AND RAYTHEON OF THE PRECEEDING MATERIAL. #12;FREQUENCY HOPPING VS. DIRECT SEQUENCE Frequency Hopping vs. Direct Sequence Spread, the techniques specified in the IEEE 802.11 Wireless LAN standard are frequency hopping spread spectrum (FHSS

  8. Spatiotemporal Phylogenetic Analysis and Molecular Characterisation of Infectious Bursal Disease Viruses Based on the VP2 Hyper-Variable Region

    PubMed Central

    Dolz, Roser; Valle, Rosa; Perera, Carmen L.; Bertran, Kateri; Frías, Maria T.; Majó, Natŕlia; Ganges, Llilianne; Pérez, Lester J.

    2013-01-01

    Background Infectious bursal disease is a highly contagious and acute viral disease caused by the infectious bursal disease virus (IBDV); it affects all major poultry producing areas of the world. The current study was designed to rigorously measure the global phylogeographic dynamics of IBDV strains to gain insight into viral population expansion as well as the emergence, spread and pattern of the geographical structure of very virulent IBDV (vvIBDV) strains. Methodology/Principal Findings Sequences of the hyper-variable region of the VP2 (HVR-VP2) gene from IBDV strains isolated from diverse geographic locations were obtained from the GenBank database; Cuban sequences were obtained in the current work. All sequences were analysed by Bayesian phylogeographic analysis, implemented in the Bayesian Evolutionary Analysis Sampling Trees (BEAST), Bayesian Tip-association Significance testing (BaTS) and Spatial Phylogenetic Reconstruction of Evolutionary Dynamics (SPREAD) software packages. Selection pressure on the HVR-VP2 was also assessed. The phylogeographic association-trait analysis showed that viruses sampled from individual countries tend to cluster together, suggesting a geographic pattern for IBDV strains. Spatial analysis from this study revealed that strains carrying sequences that were linked to increased virulence of IBDV appeared in Iran in 1981 and spread to Western Europe (Belgium) in 1987, Africa (Egypt) around 1990, East Asia (China and Japan) in 1993, the Caribbean Region (Cuba) by 1995 and South America (Brazil) around 2000. Selection pressure analysis showed that several codons in the HVR-VP2 region were under purifying selection. Conclusions/Significance To our knowledge, this work is the first study applying the Bayesian phylogeographic reconstruction approach to analyse the emergence and spread of vvIBDV strains worldwide. PMID:23805195

  9. The talk of the town: modelling the spread of information and changes in behaviour

    E-print Network

    such contacts. For instance, the rate of transmission of a sexually transmitted disease is linked and Vincent Jansen Abstract Changes in host behaviour can influence the course of a disease outbreak of a disease can spread in a population, and influence the spread of the disease itself through protective mea

  10. Emergence of Blind Areas in Information Spreading

    PubMed Central

    Han, Xiao-Pu; Liu, Chuang

    2014-01-01

    Recently, contagion-based (disease, information, etc.) spreading on social networks has been extensively studied. In this paper, other than traditional full interaction, we propose a partial interaction based spreading model, considering that the informed individuals would transmit information to only a certain fraction of their neighbors due to the transmission ability in real-world social networks. Simulation results on three representative networks (BA, ER, WS) indicate that the spreading efficiency is highly correlated with the network heterogeneity. In addition, a special phenomenon, namely Information Blind Areas where the network is separated by several information-unreachable clusters, will emerge from the spreading process. Furthermore, we also find that the size distribution of such information blind areas obeys power-law-like distribution, which has very similar exponent with that of site percolation. Detailed analyses show that the critical value is decreasing along with the network heterogeneity for the spreading process, which is complete the contrary to that of random selection. Moreover, the critical value in the latter process is also larger than that of the former for the same network. Those findings might shed some lights in in-depth understanding the effect of network properties on information spreading. PMID:24763456

  11. [20th century medical debate over venereal disease and prostitution].

    PubMed

    Lundberg, A

    2001-01-01

    In the early twentieth century a wider debate took place about how Swedish society was to fight the spread of contagious venereal diseases and in 1910 a government committee had written a law proposal that would dramatically reform these measures previously, Swedish physicians had been united against any measures against these diseases that did not involve the regulation of prostitutes, but this consensus was slowly withering away in the early parts of the century. Female doctors and a younger generation of venereologists was drawing the conclusion that mandatory checks of only one out of two sexes was insufficient. This article reviews the debate regarding the regulation of prostitution that took place between conservative and liberal members in the Swedish Medical Association in 1911. It depicts a fierce discussion between members that still clung to nineteenth-century ideas of women as being prone to prostitution if left idle and unemployed, and liberal members that believed social injustices such as low wages laid behind women's decisions. The study gives an insight into the complexities of building the Swedish welfare state. PMID:11817395

  12. Analyzing the spread of active worms over VANET

    Microsoft Academic Search

    Syed A. Khayam; Hayder Radha

    2004-01-01

    This paper investigates the parameters governing the spread of active worms over VANET. To this end, we first define the average degree of a VANET node using freeway traffic parameters. The spread of a worm in congested and low-density traffic scenarios is modeled using a stochastic model of infectious disease. Analysis is provided for preemptive and interactive patching scenarios.

  13. Susceptibility of chicken mesenchymal stem cells to infectious bursal disease virus

    Microsoft Academic Search

    Mahesh Khatri; Jagdev M. Sharma

    2009-01-01

    Infectious bursal disease virus (IBDV) is the causative agent of one of the most important viral diseases affecting the poultry industry worldwide. The virus causes an acute, highly contagious and immunosuppressive disease in chickens. Previous studies have demonstrated that in addition to B cells, macrophages can support the replication of IBDV. Since mesenchymal stem cells in bone marrow regulate the

  14. The role of transnational mobility in the local spread of mosquito-borne disease: Measuring the determinants of spatial-temporal lags of imported dengue cases initiating indigenous epidemics in Taiwan

    NASA Astrophysics Data System (ADS)

    Wen, Tzai-Hung

    2014-05-01

    Dengue fever is one of the world's most widely spread mosquito-borne diseases. International travelers who acquire dengue infection are important routes for virus transmission from one country to another one. Previous studies have shown that imported dengue cases are able to initiate indigenous epidemics when appropriate weather conditions are present. However, the spatial-temporal associations between imported cases and indigenous epidemics in areas with different social-economic conditions are still unclear. This study investigated determinants of spatial-temporal lags of imported dengue cases who initiated indigenous epidemics from 2003 to 2012 in Taiwan. The quantile regression is used to explore the associations between spatial-temporal lags of imported cases and social-economic indicators with geographic heterogeneity. Our results indicated that imported cases in April and May have statistically significant contribution to initiate indigenous epidemics. Areas with high population density and low average income have significant risk of being imported virus from other areas. However, the areas with imported cases are not significant transmission risk. The results imply that imported cases reported in early summer may be an early-warning indicator of indigenous epidemics. Local demographic and economic conditions, rather than imported cases, may determine the areas with the risk of indigenous epidemics.

  15. Systems and spread.

    PubMed

    Siriwardena, A Niroshan; Gillam, Steve

    2014-01-01

    This is the fifth in a series of papers about the science of quality improvement. In this paper, we explore the issue of healthcare as a system and how this contributes to our understanding of how to spread improvement. PMID:24589145

  16. Salmon Spread Ingredients

    E-print Network

    Liskiewicz, Maciej

    Salmon Spread Ingredients: 15 ounces salmon, canned 1 small onion 1 tablespoon lemon juice 1 salmon and place in a bowl. Use a fork to mash bones and remove skin. 2. Cut the ends off of the onion, and peel off the brown layers. Cut the onion in half lengthwise, and place the flat side on the cutting

  17. Spread spectrum image steganography

    Microsoft Academic Search

    Lisa M. Marvel; Charles G. Boncelet Jr.; Charles T. Retter

    1999-01-01

    In this paper, we present a new method of digitalsteganography, entitled spread spectrum image steganography(SSIS). Steganography, which means "covered writing" in Greek,is the science of communicating in a hidden manner. Followinga discussion of steganographic communication theory and reviewof existing techniques, the new method, SSIS, is introduced. Thissystem hides and recovers a message of substantial length withindigital imagery while maintaining the

  18. Generalized partial spreads

    Microsoft Academic Search

    Claude Carlet

    1995-01-01

    We exhibit a simple condition under which the sum (modulo 2) of characteristic functions of (n\\/2)-dimensional vector subspaces of (GF(2))n (n even) is a Bent function. The “Fourier” transform of such a Bent function is the sum of the characteristic functions of the duals of these spaces. The class of Bent functions that we obtain contains the whole partial spreads

  19. Foot-and-mouth disease: susceptibility of domestic poultry and free-living birds to infection and to disease--a review of the historical and current literature concerning the role of birds in spread of foot-and-mouth disease viruses.

    PubMed

    Kaleta, E F

    2002-09-01

    Ruminants and pigs are the dominant natural hosts of food-and-mouth disease (FMD) viruses. Approximately 70 additional mammalian species are found to be susceptible under natural or experimental conditions. Reptilia, amphibia, and fish are probably naturally resistant to infection. According to the reviewed literature, domestic birds (chickens, turkeys, guinea fowl, ducks and geese) have been experimentally infected with some strains of FMD viruses and may develop lesions suggestive of FMD such as vesicular lesions on the comb, wattles, eye lids, and feet. Since chickens are to some extent coprophagous, chickens get infected by ingestion of virus under conditions of natural exposure or their plumage gets contaminated in an infectious environment. Thus, domestic birds kept in free-run systems may serve as virus vectors for short distances. Free-living birds, especially starlings (Sturnus vulgaris), sea gulls (Larus canus), house-sparrows (Passer domesticus) have been successfully experimentally infected and developed vesicular lesions on the skin and mucosal membranes of the mouth. During epizootics of FMD the plumage of these free-living birds can be contaminated with FMD viruses and the virus is spread over long distances during migration periods in spring and autumn. Thus migrating birds may assume an active role in long distance dissemination of FMD viruses. PMID:12395578

  20. Immunisation of goats against contagious caprine pleuropneumonia using sonicated antigens of F-38 strain of mycoplasma.

    PubMed

    Rurangirwa, F R; Masiga, W N; Muthomi, E K

    1984-03-01

    Three groups of 15 goats each were immunised against contagious caprine pleuropneumonia (CCPP) using sonicated antigens of the F-38 strain of mycoplasma incorporated in incomplete Freund's adjuvant (IFA), emulsified in aluminium hydroxide and phosphate buffered saline respectively. Three months after immunisation, five goats from each group were challenged by the in-contact method. The goats immunised with the antigen incorporated in IFA were all solidly immune to the challenge whereas only two of five of the goats in the other two groups were protected. When the remaining 10 animals from each group were challenged six months after immunisation, those immunised with the antigen in IFA were still solidly immune while only two goats from each of the other two groups were protected. These results show that effective immunity against CCPP caused by the F-38 strain can be induced by vaccination with sonicated F-38 antigens emulsified in IFA. PMID:6718817

  1. Characterization of Anamnestic T-cell Responses Induced by Conventional Vaccines against Contagious Bovine Pleuropneumonia

    PubMed Central

    Totte, Philippe; Yaya, Aboubakar; Sery, Amadou; Wesonga, Hezron; Wade, Abel; Naessens, Jan; Niang, Mamadou; Thiaucourt, François

    2013-01-01

    A better understanding of how T1 vaccination confers immunity would facilitate the rational design of improved vaccines against contagious bovine pleuropneumonia (CBPP). We show here that mycoplasmas-induced recall proliferation and IFN-? responses are detected in cattle that received multiple shots of T1 vaccines. These anamnestic responses were under the strict control of CD4+ T lymphocytes. Moreover, CD62L expression indicated that both CD4+ effector memory (Tem) and central memory (Tcm) T lymphocytes are elicited in these animals. Comparative analysis with data from cattle that completely recovered from CBPP infection revealed similar anamnestic T-cell responses albeit at a lower magnitude for T1-vaccinated animals, particularly in the Tcm compartment. In conclusion, we discuss how our current understanding of T-cell responses will contribute to ongoing efforts for the improvement of future CBPP vaccines. PMID:23469008

  2. Contagious error sources would need time travel to prevent quantum computation

    E-print Network

    Gil Kalai; Greg Kuperberg

    2015-05-07

    We consider an error model for quantum computing that consists of "contagious quantum germs" that can infect every output qubit when at least one input qubit is infected. Once a germ actively causes error, it continues to cause error indefinitely for every qubit it infects, with arbitrary quantum entanglement and correlation. Although this error model looks much worse than quasi-independent error, we show that it reduces to quasi-independent error with the technique of quantum teleportation. The construction, which was previously described by Knill, is that every quantum circuit can be converted to a mixed circuit with bounded quantum depth. We also consider the restriction of bounded quantum depth from the point of view of quantum complexity classes.

  3. Prevent the Spread of Zoonotic Diseases (Spanish)

    E-print Network

    Pena, Josefa

    2008-11-10

    puede contagiar una enfermedad de animales de manera indirecta (por el medioambiente o a trav?s de moscas, mosquitos, garrapatas o pulgas) o de manera directa (a trav?s de contacto estrecho con animales). Ejemplos de enfermedades zoon?ticas incluyen...

  4. Prevent the Spread of Zoonotic Diseases

    E-print Network

    Pena, Josefa

    2008-11-10

    , and wash your hands afterward.? Place soiled laundry in a separate laundry basket, apart from other ? family clothes. Wash and disinfect clothes separately from your family?s clothes.? Use detergent.? Use household bleach.? Use water that is 130..., disinfect using a diluted household bleach solution or an EPA-? approved disinfectant with registration number on the label (Caution: Do not mix bleach with ammonia). Mix ? cup of household bleach with 1 quart of water for tires, ? vehicle undercarriages...

  5. Prevent the Spread of Zoonotic Diseases (Spanish) 

    E-print Network

    Pena, Josefa

    2008-11-10

    : sombrero ? overoles ? camisa de manga larga (algod?n o mezcla poli?ster algod?n) ? pantalones largos (algod?n o mezcla poli?ster algod?n) ? calcetines largos ? Qu?tese las botas y ropa antes de entrar en el hogar.? Mantenga toda ropa protectora aparte de...

  6. Spread spectrum image steganography.

    PubMed

    Marvel, L M; Boncelet, C R; Retter, C T

    1999-01-01

    In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking. PMID:18267522

  7. Information Spreading in Context

    NASA Astrophysics Data System (ADS)

    Wang, Dashun; Wen, Zhen; Tong, Hanghang; Lin, Ching-Yung; Song, Chaoming; Barabasi, Albert-Laszlo

    2012-02-01

    Information spreading processes are central to human interactions. Despite recent studies in online domains, little is known about factors that could affect the dissemination of a single piece of information. In this paper, we address this challenge by combining two related but distinct datasets, collected from a large scale privacy-preserving distributed social sensor system. We find that the social and organizational context significantly impacts to whom and how fast people forward information. Yet the structures within spreading processes can be well captured by a simple stochastic branching model, indicating surprising independence of context. Our results build the foundation of future predictive models of information flow and provide significant insights towards design of communication platforms.

  8. Dynamics of chromosome spreading

    SciTech Connect

    Spurbeck, J.L.; Meyer, K.J.; Jalal, S.M. [Mayo Clinic and Mayo Foundation, Rochester, MN (United States)] [and others] [Mayo Clinic and Mayo Foundation, Rochester, MN (United States); and others

    1996-02-02

    Consistency of optimum chromosome spreading during harvest of cytogenetic specimens remains a major concern. We have tested the idea that a precise control of the drying rate (the time with which metaphase cells dry), as fixed cell suspension is placed on a slide or an in situ culture in last fixation, may be the answer. Amniocyte and lymphocyte cultures were allowed to dry at defined combinations of relative humidity (RH) and temperature (T) in a modified Thermotron environmental control unit. We were able to demonstrate, based on 2,250 amniocytes and 1,650 lymphocytes, that the metaphase area after drying was a function of RH and T for both in situ and non-in situ culture systems. As the RH and T increase, the metaphase area increases until a threshold is reached. Also, as RH increases, the slide drying time increases. Data obtained using a response surface regression analysis and slide drying time studies are consistent with our model of chromosome spreading. Optimum metaphase areas can be achieved at various combinations of RH and T. We propose that the use of an environmental control unit is a practical way of achieving optimum chromosome spreading routinely and in a highly consistent manner. 11 refs., 9 figs., 4 tabs.

  9. PREDICTING ROOT SPREAD FROM TRUNK DIAMETER AND BRANCH SPREAD

    Microsoft Academic Search

    Edward F. Gilman

    1989-01-01

    Trunk diameter and branch crown spread were linearly correlated with root spread in honey locust (Gleditsia triancamhos var. inermis), green ash (Fraxinus pennsylvanica), poplar (Populus X generosa), red maple (Acer rubrum) and southern magnolia (Magnolia grandiflora) but not in live oak (Quercus virginiana). Maximum root spread (excluding live oak) ranged from 1.68 times the dripline forash to 3.77 for magnolia.

  10. Global spread and persistence of dengue.

    PubMed

    Kyle, Jennifer L; Harris, Eva

    2008-01-01

    Dengue is a spectrum of disease caused by four serotypes of the most prevalent arthropod-borne virus affecting humans today, and its incidence has increased dramatically in the past 50 years. Due in part to population growth and uncontrolled urbanization in tropical and subtropical countries, breeding sites for the mosquitoes that transmit dengue virus have proliferated, and successful vector control has proven problematic. Dengue viruses have evolved rapidly as they have spread worldwide, and genotypes associated with increased virulence have expanded from South and Southeast Asia into the Pacific and the Americas. This review explores the human, mosquito, and viral factors that contribute to the global spread and persistence of dengue, as well as the interaction between the three spheres, in the context of ecological and climate changes. What is known, as well as gaps in knowledge, is emphasized in light of future prospects for control and prevention of this pandemic disease. PMID:18429680

  11. Characterization of Newcastle disease virus isolated from cormorant and gull species in the United States in 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Newcastle disease virus (NDV), a member of the genus Avulavirus of the family Paramyxoviridae, is the causative agent of Newcastle disease (ND) a highly contagious disease that affects many species of birds and which frequently causes significant economic losses to the poultry industry worldwide. V...

  12. 25 CFR 161.206 - What must a permittee do to protect livestock from exposure to disease?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...do to protect livestock from exposure to disease? 161.206 Section 161.206 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

  13. 25 CFR 166.310 - What must a permittee do to protect livestock from exposure to disease?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...do to protect livestock from exposure to disease? 166.310 Section 166.310 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

  14. NOVEL APPROACH FOR IDENTIFICATION OF CLASS I RESTRICTED T CELL EPITOPES OF FOOT-AND-MOUTH DISEASE VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-Mouth disease Virus(FMDV) is the causative agent for a highly contagious and economically important disease affecting cloven hoofed animals including cattle and swine. Neutralizing antibody is the hallmark of protection against this disease, and important target epitopes of neutralizing an...

  15. Hybrid spread spectrum radio system

    DOEpatents

    Smith, Stephen F. (London, TN) [London, TN; Dress, William B. (Camas, WA) [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  16. The epidemiology of foot-and-mouth disease: implications for New Zealand.

    PubMed

    Sanson, R L

    1994-04-01

    Foot-and-mouth disease is an acute, highly communicable disease affecting cloven-hoofed animals, both domesticated and wild. It may well be the most contagious disease known in the animal kingdom. The key features that contribute to this include its ability to gain entry and initiate infection through a variety of sites, the small infective dose, the short incubation period, the release of virus before the onset of clinical signs, the massive quantities of virus excreted from infected animals, its ability to spread large distances due to airborne dispersal, and the persistence of the virus in the environment. These features, plus the ability of the virus to be disseminated through the movements of animals, animal products, people, and plant and equipment makes the disease very difficult to control. New Zealand has never experienced a foot-and-mouth disease epidemic, and the economic consequences of an outbreak would be disastrous, due to the eradication costs, the loss of productivity and the impact on the export of animals and animal products. The smuggling of meat products, embryos or semen into the country are perceived as the most likely ways in which the disease could be introduced. The New Zealand Ministry of Agriculture and Fisheries therefore operates a two-tier system of defense against foot-and-mouth disease. The first tier involves border protection through stringent import controls to prevent the entry of infectious material. If this barrier is breached, an emergency response programme is activated, involving a stamping-out eradication strategy. This paper attempts to draw on overseas historical outbreak experiences and research findings to gain insights into the epidemiology of foot-and-mouth disease as it would relate to New Zealand. PMID:16031745

  17. Spreading rate, spreading obliquity, and melt supply at the ultraslow spreading Southwest Indian Ridge

    Microsoft Academic Search

    Mathilde Cannat; Daniel Sauter; Antoine Bezos; Christine Meyzen; Eric Humler; Marion Le Rigoleur

    2008-01-01

    We use bathymetry, gravimetry, and basalt composition to examine the relationship between spreading rate, spreading obliquity, and the melt supply at the ultraslow spreading Southwest Indian Ridge (SWIR). We find that at regional scales (more than 200 km), melt supply reflects variations in mantle melting that are primarily controlled by large-scale heterogeneities in mantle temperature and\\/or composition. Focusing on adjacent

  18. Familiarity-connected or stress-based contagious yawning in domestic dogs (Canis familiaris)? Some additional data.

    PubMed

    Silva, Karine; Bessa, Joana; de Sousa, Liliana

    2013-11-01

    The present short note aimed at further exploring data from a recent study showing socially modulated auditory contagious yawning in domestic dogs (Canis familiaris). Two independent observers further extended the analysis of all video recordings made in the previous study and coded both the number of yawns performed by the dogs and the frequencies or durations of stress-related behaviors exhibited throughout the presentation of familiar and unfamiliar yawns. By showing no significant difference between conditions in the frequencies or durations of the coded behaviors, nor any association between the number of yawns and the frequencies or durations of stress-related behaviors, results raised doubt on the stress-induced yawn hypothesis, thus supporting social modulation. The exact mechanism underlying contagious yawning, however, needs further research. PMID:23982621

  19. 73 FR 5424 - Change in Disease Status of Surrey County, England, Because of Foot-and-Mouth Disease

    Federal Register 2010, 2011, 2012, 2013, 2014

    2008-01-30

    ...and highly contagious viral infection affecting all cloven-hoofed...cattle, deer, goats, sheep, swine, and other animals. The...communicable and is characterized by fever and blister-like lesions...products of ruminants and swine are subject to additional...NEWCASTLE DISEASE, AFRICAN SWINE FEVER, CLASSICAL SWINE FEVER, AND BOVINE......

  20. 73 FR 78925 - Change in Disease Status of Surrey County, England, Because of Foot-and-Mouth Disease

    Federal Register 2010, 2011, 2012, 2013, 2014

    2008-12-24

    ...and highly contagious viral infection affecting all cloven-hoofed...deer, goats, sheep, swine, and other animals. Section...products of ruminants and swine into the United States is...NEWCASTLE DISEASE, AFRICAN SWINE FEVER, CLASSICAL SWINE FEVER, AND BOVINE SPONGIFORM...

  1. Did vaccination slow the spread of bluetongue in France?

    PubMed

    Pioz, Maryline; Guis, Hélčne; Pleydell, David; Gay, Emilie; Calavas, Didier; Durand, Benoît; Ducrot, Christian; Lancelot, Renaud

    2014-01-01

    Vaccination is one of the most efficient ways to control the spread of infectious diseases. Simulations are now widely used to assess how vaccination can limit disease spread as well as mitigate morbidity or mortality in susceptible populations. However, field studies investigating how much vaccines decrease the velocity of epizootic wave-fronts during outbreaks are rare. This study aimed at investigating the effect of vaccination on the propagation of bluetongue, a vector-borne disease of ruminants. We used data from the 2008 bluetongue virus serotype 1 (BTV-1) epizootic of southwest France. As the virus was newly introduced in this area, natural immunity of livestock was absent. This allowed determination of the role of vaccination in changing the velocity of bluetongue spread while accounting for environmental factors that possibly influenced it. The average estimated velocity across the country despite restriction on animal movements was 5.4 km/day, which is very similar to the velocity of spread of the bluetongue virus serotype 8 epizootic in France also estimated in a context of restrictions on animal movements. Vaccination significantly reduced the propagation velocity of BTV-1. In comparison to municipalities with no vaccine coverage, the velocity of BTV-1 spread decreased by 1.7 km/day in municipalities with immunized animals. For the first time, the effect of vaccination has been quantified using data from a real epizootic whilst accounting for environmental factors known to modify the velocity of bluetongue spread. Our findings emphasize the importance of vaccination in limiting disease spread across natural landscape. Finally, environmental factors, specifically those related to vector abundance and activity, were found to be good predictors of the velocity of BTV-1 spread, indicating that these variables need to be adequately accounted for when evaluating the role of vaccination on bluetongue spread. PMID:24465562

  2. Phylogenetic and pathological characterization of Newcastle disease virus isolates from Pakistan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virulent Newcastle Disease Virus (NDV) is endemic in Pakistan and is a major problem to their poultry industry. Since Newcastle Disease is highly contagious and clinically similar to the highly pathogenic avian influenza, accurate and rapid monitoring of an outbreak is very important. Additionally, ...

  3. Role of fusion protein cleavage site in the virulence of Newcastle disease virus

    Microsoft Academic Search

    Aruna Panda; Zhuhui Huang; Subbiah Elankumaran; Daniel D Rockemann; Siba K Samal

    2004-01-01

    Newcastle disease virus (NDV) causes a highly contagious and economically important disease in poultry. Viral determinants of NDV virulence are not completely understood. The amino acid sequence at the protease cleavage site of the fusion (F) protein has been postulated as a major determinant of NDV virulence. In this study, we have examined the role of F protein cleavage site

  4. Genome-Wide SNP Association Analysis for Loci Conferring Marek's Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease (MD) is a T cell lymphoma of domestic chickens caused by Marek’s disease virus (MDV), a highly oncogenic and contagious cell-associated alpha-herpesvirus. Since the 1970s, MD has been controlled by vaccination. However, due to continuous viral evolution with increasing virulence, and...

  5. Contagious yawning, social cognition, and arousal: an investigation of the processes underlying shelter dogs' responses to human yawns.

    PubMed

    Buttner, Alicia Phillips; Strasser, Rosemary

    2014-01-01

    Studies of contagious yawning have reported inconsistent findings regarding whether dogs exhibit this behavior and whether it is mediated by social-cognitive processes or the result of physiological arousal. We investigated why some dogs yawn in response to human yawns; particularly, whether these dogs are exceptional in their ability to understand human social cues or whether they were more physiologically aroused. Sixty shelter dogs were exposed to yawning and nonyawning control stimuli demonstrated by an unfamiliar human. We took salivary cortisol samples before and after testing to determine the role of arousal in yawn contagion. Dogs were tested on the object-choice task to assess their sensitivity for interpreting human social cues. We found that 12 dogs yawned only in response to human yawns (i.e., appeared to exhibit yawn contagion), though contagious yawning at the population level was not observed. Dogs that exhibited yawn contagion did not perform better on the object-choice task than other dogs, but their cortisol levels remained elevated after exposure to human yawning, whereas other dogs had reduced cortisol levels following yawning stimuli relative to their baseline levels. We interpret these findings as showing that human yawning, when presented in a stressful context, can further influence arousal in dogs, which then causes some to yawn. Although the precise social-cognitive mechanisms that underlie contagious yawning in dogs are still unclear, yawning between humans and dogs may involve some communicative function that is modulated by context and arousal. PMID:23670215

  6. Axonal and Transynaptic Spread of Prions

    PubMed Central

    Shearin, Harold

    2014-01-01

    ABSTRACT Natural transmission of prion diseases depends upon the spread of prions from the nervous system to excretory or secretory tissues, but the mechanism of prion transport in axons and into peripheral tissue is unresolved. Here, we examined the temporal and spatial movement of prions from the brain stem along cranial nerves into skeletal muscle as a model of axonal transport and transynaptic spread. The disease-specific isoform of the prion protein, PrPSc, was observed in nerve fibers of the tongue approximately 2 weeks prior to PrPSc deposition in skeletal muscle. Initially, PrPSc deposits had a small punctate pattern on the edge of muscle cells that colocalized with synaptophysin, a marker for the neuromuscular junction (NMJ), in >50% of the cells. At later time points PrPSc was widely distributed in muscle cells, but <10% of prion-infected cells exhibited PrPSc deposition at the NMJ, suggesting additional prion replication and dissemination within muscle cells. In contrast to the NMJ, PrPSc was not associated with synaptophysin in nerve fibers but was found to colocalize with LAMP-1 and cathepsin D during early stages of axonal spread. We propose that PrPSc-bound endosomes can lead to membrane recycling in which PrPSc is directed to the synapse, where it either moves across the NMJ into the postsynaptic muscle cell or induces PrPSc formation on muscle cells across the NMJ. IMPORTANCE Prion diseases are transmissible and fatal neurodegenerative diseases in which prion dissemination to excretory or secretory tissues is necessary for natural disease transmission. Despite the importance of this pathway, the cellular mechanism of prion transport in axons and into peripheral tissue is unresolved. This study demonstrates anterograde spread of prions within nerve fibers prior to infection of peripheral synapses (i.e., neuromuscular junction) and infection of peripheral tissues (i.e., muscle cells). Within nerve fibers prions were associated with the endosomal-lysosomal pathway prior to entry into muscle cells. Since early prion spread is anterograde and endosome-lysosomal movement within axons is primarily retrograde, these findings suggest that endosome-bound prions may have an alternate fate that directs prions to the peripheral synapse. PMID:24850738

  7. Experimental contagious caprine pleuropneumonia: a long term study on the course of infection and pathology in a flock of goats infected with Mycoplasma capricolum subsp. capripneumoniae.

    PubMed

    Wesonga, H O; Bölske, G; Thiaucourt, F; Wanjohi, C; Lindberg, R

    2004-01-01

    Contagious caprine pleuropneumonia (CCPP) is a major threat to goat farming in parts of Africa and Asia. It classically causes acute high morbidity and mortality early in infection, but little is known of its long term epizootiology and course. In this study, 10 goats were inoculated with Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae) and then mixed with 15 goats for contact transmission. The disease course was monitored in each goat for 56-105 days, whereafter the goats were killed and necropsied. Varying features signifying infection occurred in altogether 17 goats (7 inoculated, 10 in-contact). Clinical signs were severe in 8 goats but no fatalities occurred. Only 6 goats had serum antibody titres against M. capripneumoniae in ELISA. Fourteen goats (5 inoculated, 9 in-contact) had chronic pleuropulmonary lesions compatible with CCPP at necropsy and 7 of those showed M. capripneumoniae antigen in the lung by immunohistochemistry. Neither cultivation nor PCR tests were positive for the agent in any goat. The results indicate that the clinical course of CCPP in a flock may be comparatively mild, M. capripneumoniae-associated lung lesions may be present at a late stage of infection, and chronic infection may occur without a significant serological response. PMID:15663077

  8. Experimental Contagious Caprine Pleuropneumonia: A Long Term Study on the Course of Infection and Pathology in a Flock of Goats Infected with Mycoplasma capricolum subsp. capripneumoniae

    PubMed Central

    Wesonga, HO; Bölske, G; Thiaucourt, F; Wanjohi, C; Lindberg, R

    2004-01-01

    Contagious caprine pleuropneumonia (CCPP) is a major threat to goat farming in parts of Africa and Asia. It classically causes acute high morbidity and mortality early in infection, but little is known of its long term epizootiology and course. In this study, 10 goats were inoculated with Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae) and then mixed with 15 goats for contact transmission. The disease course was monitored in each goat for 56–105 days, whereafter the goats were killed and necropsied. Varying features signifying infection occurred in altogether 17 goats (7 inoculated, 10 in-contact). Clinical signs were severe in 8 goats but no fatalities occurred. Only 6 goats had serum antibody titres against M. capripneumoniae in ELISA. Fourteen goats (5 inoculated, 9 in-contact) had chronic pleuropulmonary lesions compatible with CCPP at necropsy and 7 of those showed M. capripneumoniae antigen in the lung by immunohistochemistry. Neither cultivation nor PCR tests were positive for the agent in any goat. The results indicate that the clinical course of CCPP in a flock may be comparatively mild, M. capripneumoniae-associated lung lesions may be present at a late stage of infection, and chronic infection may occur without a significant serological response. PMID:15663077

  9. [Reclassification of the four China isolated strains of the pathogen for contagious caprine pleuropneumonia].

    PubMed

    Li, Yuan; Zhang, Jian-Hua; Hu, Shou-Ping; Wang, Liang; Xin, Jiu-Qing

    2007-10-01

    Contagious caprine pleuropneumonia (CCPP) is caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp). The aims of this study were to identify 4 Chinese isolated strains employing molecular methods and to determine the appropriate subspecies classification of these strains. Three genome fragments (A, B and C) from each strain were amplified and then transformed into plasmids. The inserted fragments were sequenced and analyzed by comparison with six members of the Mycoplasma mycoides cluster. Cleavage of the PCR products of the 4 strains with PstI yielded three fragments 548, 420 and 128bp in length, just like strain F38. The other M. mycoides cluster members had only 2 fragments of 428 and 128bp. Homology analysis of fragment B indicated that the 4 strains exhibited 99.5% homology with Mccp reference strain F38, 98.9% with M. capricolum subsp. Capricolum (Mcc) strain California Kid, and only 95.4% with Mmc strain ZZ. In fragment C, the 4 strains had 67.4% - 67.6% homology with Mmc PG3, 95.1% -98.6% with Mcc strains 8601-50 and California Kid, 99.6% - 99.8% with Mccp strains 97097ET, Gabes and F38. The analysis revealed that 4 pathogeny strains, 87001, 87002, 367, 1653, isolated from China are more closely related to Mccp than to Mcc. Therefore the pathogeny of CCPP in China should be reclassified as Mccp. PMID:18062246

  10. Prevalence of contagious mastitis pathogens in bulk tank milk in Québec

    PubMed Central

    Francoz, David; Bergeron, Luc; Nadeau, Marie; Beauchamp, Guy

    2012-01-01

    The objective of this study was to estimate the prevalence of mycoplasma, Staphylococcus aureus, and Streptococcus agalactiae in bulk tank milk (BTM) in Québec dairy herds. BTM was sampled 3 times a month in 117 randomly selected dairy herds. Samples were submitted for S. aureus, S. agalactiae, and mycoplasma and for direct mycoplasma detection by polymerase chain reaction (PCR). Mycoplasma spp. was identified at least once in 3 herds (2.6%) by primary culture and/or PCR and in 4 herds (3.4%) by enrichment culture and/or PCR. Staphylococcus aureus was isolated at least once in 99 (84.6%) and 112 (95.7%) herds in primary culture and after enrichment, respectively. Streptococcus agalactiae was isolated at least once in 9 (7.7%) and 10 (8.6%) herds in primary culture and after enrichment, respectively. Herd prevalence of mycoplasma was similar to that previously reported in Canada. Staphylococcus aureus is still by far the most important contagious mastitis pathogen. PMID:23543925

  11. Lesion of the olfactory epithelium accelerates prion neuroinvasion and disease onset when prion replication is restricted to neurons.

    PubMed

    Crowell, Jenna; Wiley, James A; Bessen, Richard A

    2015-01-01

    Natural prion diseases of ruminants are moderately contagious and while the gastrointestinal tract is the primary site of prion agent entry, other mucosae may be entry sites in a subset of infections. In the current study we examined prion neuroinvasion and disease induction following disruption of the olfactory epithelium in the nasal mucosa since this site contains environmentally exposed olfactory sensory neurons that project directly into the central nervous system. Here we provide evidence for accelerated prion neuroinvasion and clinical onset from the olfactory mucosa after disruption and regeneration of the olfactory epithelium and when prion replication is restricted to neurons. In transgenic mice with neuron restricted replication of prions, there was a reduction in survival when the olfactory epithelium was disrupted prior to intranasal inoculation and there was >25% decrease in the prion incubation period. In a second model, the neurotropic DY strain of transmissible mink encephalopathy was not pathogenic in hamsters by the nasal route, but 50% of animals exhibited brain infection and/or disease when the olfactory epithelium was disrupted prior to intranasal inoculation. A time course analysis of prion deposition in the brain following loss of the olfactory epithelium in models of neuron-restricted prion replication suggests that neuroinvasion from the olfactory mucosa is via the olfactory nerve or brain stem associated cranial nerves. We propose that induction of neurogenesis after damage to the olfactory epithelium can lead to prion infection of immature olfactory sensory neurons and accelerate prion spread to the brain. PMID:25822718

  12. Intensity dependent spread theory

    NASA Technical Reports Server (NTRS)

    Holben, Richard

    1990-01-01

    The Intensity Dependent Spread (IDS) procedure is an image-processing technique based on a model of the processing which occurs in the human visual system. IDS processing is relevant to many aspects of machine vision and image processing. For quantum limited images, it produces an ideal trade-off between spatial resolution and noise averaging, performs edge enhancement thus requiring only mean-crossing detection for the subsequent extraction of scene edges, and yields edge responses whose amplitudes are independent of scene illumination, depending only upon the ratio of the reflectance on the two sides of the edge. These properties suggest that the IDS process may provide significant bandwidth reduction while losing only minimal scene information when used as a preprocessor at or near the image plane.

  13. Molecular characterization of partial fusion gene and C-terminus extension length of haemagglutinin-neuraminidase gene of recently isolated Newcastle disease virus isolates in Malaysia

    Microsoft Academic Search

    Ayalew Berhanu; Aini Ideris; Abdul R Omar; Mohd Hair Bejo

    2010-01-01

    BACKGROUND: Newcastle disease (ND), caused by Newcastle disease virus (NDV), is a highly contagious disease of birds and has been one of the major causes of economic losses in the poultry industry. Despite routine vaccination programs, sporadic cases have occasionally occurred in the country and remain a constant threat to commercial poultry. Hence, the present study was aimed to characterize

  14. Vaccine by chicken line interaction alters the protective efficacy against challenge with a very virulent plus strain of Marek's disease virus in white leghorn chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease (MD) is a lymphoproliferative disease of domestic chickens caused by Marek’s disease virus (MDV), an oncogenic and highly contagious a-herpesvirus. MD has been controlled by vaccination but sporadic outbreaks of MD still occur in some parts of the world. Efforts to improve vaccine ef...

  15. A new kinetic model to discuss the control of panic spreading in emergency

    NASA Astrophysics Data System (ADS)

    Chen, Guanghua; Shen, Huizhang; Chen, Guangming; Ye, Teng; Tang, Xiangbin; Kerr, Naphtali

    2015-01-01

    Individual panic behavior during an emergency is contagious. It often leads to collective panic behavior, which can be disruptive and even disastrous if handled incorrectly. In this paper, a novel kinetic model is developed to describe the dynamics of panic spreading in a real emergency. The global dynamics of the proposed model are analyzed by using the method of Lyapunov function and the Poincarč-Bendixson property, and the obtained theoretical results are numerically validated. The Runge-Kutta method is used for numerical simulations, and these simulations are used to investigate the impact of corresponding management strategies on the containment of individual panic behavior. Meanwhile, the implications of these simulation results are discussed with the "2011 Xiangshui chemical explosion rumor" event. Finally, some recommendations for emergency management agencies are put forward by us to reduce individual panic behavior.

  16. Chikungunya: Evolutionary history and recent epidemic spread.

    PubMed

    Weaver, Scott C; Forrester, Naomi L

    2015-08-01

    Chikungunya virus (CHIKV) has a long history of emergence into urban transmission cycles from its ancestral, enzootic, sylvatic foci in Sub-Saharan Africa, most recently spreading to the Americas beginning in 2013. Since 2004, reemergence has resulted in millions of cases of severe, debilitating and often chronic arthralgia on five continents. Here, we review this history based on phylogenetic studies, and discuss probable future spread and disease in the Americas. We also discuss a series of mutations in the recently emerged Indian Ocean Lineage that has adapted the virus for transmission for the first time by the Aedes albopictus urban mosquito vector, and compare CHIKV to other arboviruses with and without similar histories of urbanization. This article forms part of a symposium in Antiviral Research on "Chikungunya discovers the New World." PMID:25979669

  17. Chimpanzees show a developmental increase in susceptibility to contagious yawning: a test of the effect of ontogeny and emotional closeness on yawn contagion.

    PubMed

    Madsen, Elainie Alenkćr; Persson, Tomas; Sayehli, Susan; Lenninger, Sara; Sonesson, Göran

    2013-01-01

    Contagious yawning has been reported for humans, dogs and several non-human primate species, and associated with empathy in humans and other primates. Still, the function, development and underlying mechanisms of contagious yawning remain unclear. Humans and dogs show a developmental increase in susceptibility to yawn contagion, with children showing an increase around the age of four, when also empathy-related behaviours and accurate identification of others' emotions begin to clearly evince. Explicit tests of yawn contagion in non-human apes have only involved adult individuals and examined the existence of conspecific yawn contagion. Here we report the first study of heterospecific contagious yawning in primates, and the ontogeny of susceptibility thereto in chimpanzees, Pan troglodytes verus. We examined whether emotional closeness, defined as attachment history with the yawning model, affected the strength of contagion, and compared the contagiousness of yawning to nose-wiping. Thirty-three orphaned chimpanzees observed an unfamiliar and familiar human (their surrogate human mother) yawn, gape and nose-wipe. Yawning, but not nose-wiping, was contagious for juvenile chimpanzees, while infants were immune to contagion. Like humans and dogs, chimpanzees are subject to a developmental trend in susceptibility to contagious yawning, and respond to heterospecific yawn stimuli. Emotional closeness with the model did not affect contagion. The familiarity-biased social modulatory effect on yawn contagion previously found among some adult primates, seem to only emerge later in development, or be limited to interactions with conspecifics. The influence of the 'chameleon effect', targeted vs. generalised empathy, perspective-taking and visual attention on contagious yawning is discussed. PMID:24146848

  18. Chimpanzees Show a Developmental Increase in Susceptibility to Contagious Yawning: A Test of the Effect of Ontogeny and Emotional Closeness on Yawn Contagion

    PubMed Central

    Madsen, Elainie Alenkćr; Persson, Tomas; Sayehli, Susan; Lenninger, Sara; Sonesson, Göran

    2013-01-01

    Contagious yawning has been reported for humans, dogs and several non-human primate species, and associated with empathy in humans and other primates. Still, the function, development and underlying mechanisms of contagious yawning remain unclear. Humans and dogs show a developmental increase in susceptibility to yawn contagion, with children showing an increase around the age of four, when also empathy-related behaviours and accurate identification of others’ emotions begin to clearly evince. Explicit tests of yawn contagion in non-human apes have only involved adult individuals and examined the existence of conspecific yawn contagion. Here we report the first study of heterospecific contagious yawning in primates, and the ontogeny of susceptibility thereto in chimpanzees, Pan troglodytes verus. We examined whether emotional closeness, defined as attachment history with the yawning model, affected the strength of contagion, and compared the contagiousness of yawning to nose-wiping. Thirty-three orphaned chimpanzees observed an unfamiliar and familiar human (their surrogate human mother) yawn, gape and nose-wipe. Yawning, but not nose-wiping, was contagious for juvenile chimpanzees, while infants were immune to contagion. Like humans and dogs, chimpanzees are subject to a developmental trend in susceptibility to contagious yawning, and respond to heterospecific yawn stimuli. Emotional closeness with the model did not affect contagion. The familiarity-biased social modulatory effect on yawn contagion previously found among some adult primates, seem to only emerge later in development, or be limited to interactions with conspecifics. The influence of the ‘chameleon effect’, targeted vs. generalised empathy, perspective-taking and visual attention on contagious yawning is discussed. PMID:24146848

  19. Spreading of Persistent Infections in Heterogeneous Populations

    E-print Network

    Sanz, J; Moreno, Y

    2010-01-01

    Up to now, the effects of having heterogeneous networks of contacts have been studied mostly for diseases which are not persistent in time, i.e., for diseases where the infectious period can be considered very small compared to the lifetime of an individual. Moreover, all these previous results have been obtained for closed populations, where the number of individuals does not change during the whole duration of the epidemics. Here, we go one step further and analyze, both analytically and numerically, a radically different kind of diseases: those that are persistent and can last for an individual's lifetime. To be more specific, we particularize to the case of Tuberculosis' (TB) infection dynamics, where the infection remains latent for a period of time before showing up and spreading to other individuals. We introduce an epidemiological model for TB-like persistent infections taking into account the heterogeneity inherent to the population structure. This sort of dynamics introduces new analytical and numer...

  20. PREVENTING DISEASES AND INFECTIONS

    NSDL National Science Digital Library

    Mr. Hughes

    2006-02-19

    DESK Standard: Determine how communicable diseases are spread. . DATES: You can begin this activity on January 8. You should complete it by January 12. OBJECTIVE: Everyone wants to feel healthy because being sick is a drag! We have been discussing ways to prevent the spread of infections and diseases during class. There are many ...

  1. Islamic Universities Spread through Africa

    ERIC Educational Resources Information Center

    Lindow, Megan

    2007-01-01

    This article reports on new universities for Muslims, many supported by groups in the Middle East, which are spreading through the sub-Saharan region. The Islamic University in Uganda is a prime example of a new kind of institution that has slowly been spreading its way across the continent. Embracing both conservative Muslim values and modern…

  2. PATHOGENIC CHARACTERISTICS OF THE KOREAN 2002 ISOLATE OF FOOT-AND-MOUTH DISEASE VIRUS SEROTYPE O IN PIGS AND CATTLE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experimental infection of susceptible cattle and pigs with foot-and-mouth disease virus (FMDV) O/SKN/AS/2002 pig strain indicates that this virus causes a disease that is highly virulent and contagious in swine, but causes a very limited infection in bovine. Pigs directly inoculated with, or expose...

  3. POTENTIAL ROLE OF FLIES IN THE PERSISTENCE AND DISPERSAL OF EXOTIC NEWCASTLE DISEASE VIRUS IN SOUTHERN CALIFORNIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic Newcastle Disease (END) is a highly virulent and contagious disease affecting poultry and other birds with the potential of causing 100% mortality in unvaccinated poultry. Transmission of END virus to susceptible birds is primarily thought to occur via direct contact with infected birds or in...

  4. Poly ICLC increases the potency of a replication-defective human adenovirus vectored foot-and-mouth disease vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. We have previously demonstrated that a replication-defective human adenovirus 5 vector carrying the FMDV capsid coding region of serotype A24 Cruzeiro (Ad5-CI-A24-2B) protects swine and cattle against FM...

  5. Cross-sectional study on Contagious Caprine Pleuro Pneumonia in selected districts of sedentary and pastoral production systems in Southern Ethiopia.

    PubMed

    Mekuria, Solomon; Asmare, Kassahun

    2010-01-01

    A study to estimate the seroprevalence of Contagious Caprine Pluropneumonia (CCPP) in southern Ethiopia was conducted from November 2005 to June 2006. Two districts from sedentary (Arbaminch and Boreda) and pastoral (Hammar and Bena-Tsemay) production systems were included in the study. Sera samples were collected from 913 goats (234 from sedentary and 679 from pastoral) to check for CCPP serostatus. The animals were sampled from 155 flocks (44 pastoral and 111 sedentary). Five clinically suspected CCPP cases were also sacrificed and attempt was made to isolate Mycoplasma capricolum capripneumoniae (MccP) from lung tissue, nasal swab and plural exudates. Sera samples were tested for the presence of CCPP antibodies using CFT. The overall seroprevalence recorded in the study was 18.61%. The corresponding seroprevalences for sedentary and pastoral production systems were 27.78% and 15.46% respectively. Regarding districts, the prevalence in Hammar was 15.63% while that of Bena-Tsemay 15.29%. In Arbaminch and Boreda the percent of seroreactors were 23.01 and 32.23% respectively. Out of 44 pastoral and 111 sedentary flocks, 50.45% of pastoral and 65.91% of sedentary flocks had at least one seroreactor goat per flock respectively. Both in the univariable and multivariable logistic regression analysis, seropositivity was found to have strong association with sedentary production system (P < 0.05, OR = 2.24) and adult age (P < 0.05, OR = 1.77). In microbiological study, two broth cultures from thoracic fluid and two broth cultures from lung tissue samples were found to be positive for Mycoplasma capricolum capripneumoniae (MccP). In conclusion, both the serological study and bacteriological isolation confirmed the disease CCPP being an important disease that demands serious attention in both production systems. PMID:19551484

  6. Evolution of Marek’s disease – A paradigm for incessant race between the pathogen and the host

    Microsoft Academic Search

    Venugopal Nair

    2005-01-01

    Marek’s disease (MD) is a highly contagious lymphoproliferative disease of poultry caused by the oncogenic herpesvirus designated Marek’s disease virus (MDV). MD has a worldwide distribution and is thought to cause an annual loss over US$1 bn to the poultry industry. Originally described as a paralytic disease, today MD is mostly manifested as an acute disease with tumours in multiple

  7. The role of veterinary epidemiology in combating infectious animal diseases on a global scale: the impact of training and outreach programs.

    PubMed

    Salman, M D

    2009-12-01

    The effectiveness of detection and control of highly contagious animal diseases is dependent on a solid understanding of their nature and implementation of scientifically sound methods by people who are well trained. The implementation of specific detection methods and tools requires training and application in natural as well as field conditions. The aim of this paper is to present the design and implementation of training in disease investigation and basic veterinary epidemiology in selected countries using the Highly Pathogenic Avian Influenza (HPAI) H5N1 Asia strain as a disease detection model. Indonesia, Egypt, Nigeria, Turkey, and Vietnam were each identified as either a priority country where AI was spreading rapidly or a country at risk for infection. In each of these countries, a training program on epidemiological concepts, field investigation methodology, and detection of H5N1 Asia strain cases was conducted. This report includes the impact of these training sessions on national animal health programs, including follow-up activities of animal health officers who went through these training sessions. PMID:19781798

  8. Economic Impacts of Potential Foot and Mouth Disease Agro-terrorism in the United States: A Computable General Equilibrium Analysis

    SciTech Connect

    Oladosu, Gbadebo A [ORNL] [ORNL; Rose, Adam [University of Southern California, Los Angeles] [University of Southern California, Los Angeles; Bumsoo, Lee [University of Illinois] [University of Illinois

    2013-01-01

    The foot and mouth disease (FMD) virus has high agro-terrorism potential because it is contagious, can be easily transmitted via inanimate objects and can be spread by wind. An outbreak of FMD in developed countries results in massive slaughtering of animals (for disease control) and disruptions in meat supply chains and trade, with potentially large economic losses. Although the United States has been FMD-free since 1929, the potential of FMD as a deliberate terrorist weapon calls for estimates of the physical and economic damage that could result from an outbreak. This paper estimates the economic impacts of three alternative scenarios of potential FMD attacks using a computable general equilibrium (CGE) model of the US economy. The three scenarios range from a small outbreak successfully contained within a state to a large multi-state attack resulting in slaughtering of 30 percent of the national livestock. Overall, the value of total output losses in our simulations range between $37 billion (0.15% of 2006 baseline economic output) and $228 billion (0.92%). Major impacts stem from the supply constraint on livestock due to massive animal slaughtering. As expected, the economic losses are heavily concentrated in agriculture and food manufacturing sectors, with losses ranging from $23 billion to $61 billion in the two industries.

  9. Use of personal digital assistant devices in order to access, consult and apply a corpus of clinical guidelines and decision-based support documentation like the Italian SPREAD Guidelines on stroke disease

    Microsoft Academic Search

    I. Cricelli

    2006-01-01

    During the past few years, personal digital assistants (PDAs) have become widespread commodities, like computers and mobile\\u000a phones. Many health-care providers, particularly physicians, routinely use PDAs in their everyday work. Accessing guidelines\\u000a and clinical decision-based support tools, such as the downloadable version of the Italian SPREAD Guidelines represents one\\u000a of the most important and common clinical applications. The current experience

  10. Antibody inhibition of human cytomegalovirus spread in epithelial cell cultures

    PubMed Central

    Cui, Xiaohong; Lee, Ronzo; Adler, Stuart P.; McVoy, Michael A.

    2013-01-01

    Anti-cytomegalovirus (CMV) antibodies reduce the incidence of CMV transmission and ameliorate the severity of CMV-associated disease. Neutralizing activity, measured as the ability of antibodies to prevent entry of cell-free virus, is an important component of natural immunity. However, in vivo CMV amplification may occur mainly via spread between adjacent cells within tissues. Thus, inhibition of cell-to-cell spread may be important when evaluating therapeutic antibodies or humoral responses to infection or immunization. In vitro CMV cell-to-cell spread is largely resistant to antibodies in fibroblast cultures but sensitive in endothelial cell cultures. In the present study antibodies in CMV hyperimmuneglobulin or seropositive human sera inhibited CMV cell-to-cell spread in epithelial cell cultures. Spread inhibition activity was quantitated with a GFP reporter assay employing GFP-tagged epithelialtropic variants of CMV strains Towne or AD169. Measurement of spread inhibition provides an additional parameter for the evaluation of candidate vaccines or immunotherapeutics and to further characterize the role of antibodies in controlling CMV transmission and disease. PMID:23669101

  11. Virus inactivation by salt (NaCl) and phosphate supplemented salt in a 3D collagen matrix model for natural sausage casings

    Microsoft Academic Search

    Tinka Wieringa-Jelsma; Joris J. Wijnker; Esther M. Zijlstra-Willems; Aldo Dekker; Norbert Stockhofe-Zurwieden; Riks Maas; Henk J. Wisselink

    2011-01-01

    Due to possible presence and spread of contagious animal viruses via natural sausage casings the international trade in these food products is subject to veterinary and public health requirements. In order to manage these restrictions we determined the effect of casing preservation on four highly contagious viruses for livestock: foot-and-mouth-disease virus (FMDV), classical swine fever virus (CSFV), swine vesicular disease

  12. First report on the molecular prevalence of Mycoplasma capricolum subspecies capripneumoniae (Mccp) in goats the cause of contagious caprine pleuropneumonia (CCPP) in Balochistan province of Pakistan.

    PubMed

    Awan, Mohammad Arif; Abbas, Ferhat; Yasinzai, Masoom; Nicholas, Robin A J; Babar, Shakeel; Ayling, Roger D; Attique, Mohammad Adnan; Ahmed, Zafar; Wadood, Abdul; Khan, Faisal Ameer

    2010-10-01

    Contagious caprine pleuropneumonia (CCPP) caused by Mycoplasma capricolum subspecies capripneumoniae (Mccp) is a disease of goats which causes high morbidity and mortality and is reported in many countries of the world. There are probably no reports on the molecular prevalence of Mccp, Mycoplasma capricolum subsp. capricolum (Mcc) and Mycoplasma putrefaciens (Mp) in Balochistan and any other part of Pakistan. Thirty goats (n = 30) with marked respiratory symptoms were selected and procured from forty goat flocks in Pishin district of Balochistan in 2008. The genomic deoxyribonucleic acid (DNA) from the lung samples (n = 30) of the slaughtered goats was purified and subjected to polymerase chain reaction (PCR) assays for the presence of Mycoplasma mycoides cluster members and Mp. The PCR-RFLP (restriction fragment length polymorphism) was also used to further confirm the Mccp. Of the thirty lung samples 17 (56.67%) were positive for the molecular prevalence of Mcc, Mccp and Mp. In total the molecular prevalence was observed as 17.65% for Mccp (n = 3), 70.59% for Mcc (n = 12) and 11.76% for Mp (n = 2). The RFLP profile has also validated the PCR results of Mccp by yielding two bands of 190 and 126 bp. The results of PCR-RFLP coupled with the presence of fibrinous pleuropneumonia and pleurisy during postmortem of goats (n = 3) strongly indicated the prevalence of CCPP in this part of world. Moreover the prevalence of Mcc and Mp is also alarming in the study area. We report for the very first time the molecular prevalence of Mcc, Mccp, and Mp in the lung tissues of goats in the Pishin district of Balochistan, Pakistan. PMID:20091126

  13. A molecular epidemiology of treponemes in beef cattle digital dermatitis lesions and comparative analyses with sheep contagious ovine digital dermatitis and dairy cattle digital dermatitis lesions.

    PubMed

    Sullivan, L E; Evans, N J; Blowey, R W; Grove-White, D H; Clegg, S R; Duncan, J S; Carter, S D

    2015-07-01

    Bovine digital dermatitis (BDD) is an infective foot disease commonly reported in dairy cattle where Treponema are considered as the primary causative infectious agents. There still remains little definitive information on the etiology of BDD in beef cattle suggesting further investigations are warranted. Beef BDD lesions (n=34) and healthy beef foot tissues (n=38) were analysed by PCR for three BDD-associated Treponema phylogroups and also for Dichelobacter nodosus and Fusobacterium necrophorum. Spirochete culture was attempted on all BDD lesion samples. One or more BDD-associated Treponema phylogroups were detected in 100% of beef BDD lesions. "Treponema medium/Treponema vincentii-like", "Treponema phagedenis-like" and Treponema pedis spirochetes were identified in 27/34 (79%), 31/34 (91%) and 24/34 (71%) of BDD lesions, respectively. No BDD-associated treponeme DNA was amplified from beef healthy foot tissues. D. nodosus and F. necrophorum were present in 24/34 (71%) and 15/34 (44%) of lesions and 10/38 (26%) and 12/38 (32%) of healthy foot tissues, respectively. Twenty spirochetes were isolated from beef BDD lesions; 19 were representatives of the three BDD-associated Treponema phylogroups. One spirochete isolate shared less than 97% 16S rRNA gene similarity to the three cultivable BDD-associated Treponema phylogroups and therefore may represent a novel taxa of Treponema. Upon comparison, sheep contagious ovine digital dermatitis (CODD), dairy cattle and beef cattle BDD lesions appear to have extremely similar bacteriological data and therefore provides evidence of a shared etiopathogenesis posing concerns for cross-species transmission. PMID:25937315

  14. Treatment with interferon-alpha delays disease in swine infected with a highly virulent CSFV strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Classical swine fever (CSF) is an economically significant, highly contagious swine disease. The etiological agent, CSF virus (CSFV), is an enveloped virus with a positive-sense, single-stranded RNA genome, classified as a member of the genus Pestivirus within the family Flaviviridae (Becher et al.,...

  15. Worldwide Spread of Dengue Virus Type 1

    PubMed Central

    Villabona-Arenas, Christian Julián; Zanotto, Paolo Marinho de Andrade

    2013-01-01

    Background DENV-1 is one of the four viral serotypes that causes Dengue, the most common mosquito-borne viral disease of humans. The prevalence of these viruses has grown in recent decades and is now present in more than 100 countries. Limited studies document the spread of DENV-1 over the world despite its importance for human health. Methodology/Principal Findings We used representative DENV-1 envelope gene sequences to unravel the dynamics of viral diffusion under a Bayesian phylogeographic approach. Data included strains from 45 distinct geographic locations isolated from 1944 to 2009. The estimated mean rate of nucleotide substitution was 6.56×10?4 substitutions/site/year. The larger genotypes (I, IV and V) had a distinctive phylogenetic structure and since 1990 they experienced effective population size oscillations. Thailand and Indonesia represented the main sources of strains for neighboring countries. Besides, Asia broadcast lineages into the Americas and the Pacific region that diverged in isolation. Also, a transmission network analysis revealed the pivotal role of Indochina in the global diffusion of DENV-1 and of the Caribbean in the diffusion over the Americas. Conclusions/Significance The study summarizes the spatiotemporal DENV-1 worldwide spread that may help disease control. PMID:23675416

  16. Newcastle disease virus (NDV) recombinants expressing infectious laryngotracheitis virus (ILTV) glycoproteins gB and gD protect chickens against ILTV and NDV challenges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infectious laryngotracheitis (ILT) is a highly contagious acute respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is mainly controlled through biosecurity and vaccination with live-attenuated strains of the virus and vectored vaccines based on turkey he...

  17. Synchrony, Waves, and Spatial Hierarchies in the Spread of Influenza

    E-print Network

    Synchrony, Waves, and Spatial Hierarchies in the Spread of Influenza Ce´cile Viboud,1 * Ottar N-range dissemination of infectious diseases is a key issue in their dynamics and control. Here, we use influenza-related mortality data to analyze the between-state progression of interpandemic influenza in the United States over

  18. Fallopian Tube Cancer: Incidence and Role of Lymphatic Spread

    Microsoft Academic Search

    Emanuela di Re; Giuseppe Grosso; Francesco Raspagliesi; Gabriela Baiocchi

    1996-01-01

    Lymphatic spread pattern in 17 cases of adenocarcinoma of fallopian tube is reported. Median age of the patients was 48 years. All patients underwent surgical staging including total abdominal hysterectomy, bilateral salpingo-oopherectomy omentectomy, and appendectomy. Systematic pelvic and para-aortic lymphadenectomy was feasible in 15 cases. Majority of the patients (11 of 17 cases, 64%) had advanced disease and showed serous

  19. Detection of African swine fever, classical swine fever, and foot-and-mouth disease viruses in swine oral fluids by multiplex reverse transcription real-time polymerase chain reaction.

    PubMed

    Grau, Frederic R; Schroeder, Megan E; Mulhern, Erin L; McIntosh, Michael T; Bounpheng, Mangkey A

    2015-03-01

    African swine fever (ASF), classical swine fever (CSF), and foot-and-mouth disease (FMD) are highly contagious animal diseases of significant economic importance. Pigs infected with ASF and CSF viruses (ASFV and CSFV) develop clinical signs that may be indistinguishable from other diseases. Likewise, various causes of vesicular disease can mimic clinical signs caused by the FMD virus (FMDV). Early detection is critical to limiting the impact and spread of these disease outbreaks, and the ability to perform herd-level surveillance for all 3 diseases rapidly and cost effectively using a single diagnostic sample and test is highly desirable. This study assessed the feasibility of simultaneous ASFV, CSFV, and FMDV detection by multiplex reverse transcription real-time polymerase chain reaction (mRT-qPCR) in swine oral fluids collected through the use of chewing ropes. Animal groups were experimentally infected independently with each virus, observed for clinical signs, and oral fluids collected and tested throughout the course of infection. All animal groups chewed on the ropes readily before and after onset of clinical signs and before onset of lameness or serious clinical signs. ASFV was detected as early as 3 days postinoculation (dpi), 2-3 days before onset of clinical disease; CSFV was detected at 5 dpi, coincident with onset of clinical disease; and FMDV was detected as early as 1 dpi, 1 day before the onset of clinical disease. Equivalent results were observed in 4 independent studies and demonstrate the feasibility of oral fluids and mRT-qPCR for surveillance of ASF, CSF, and FMD in swine populations. PMID:25776540

  20. A Review of Exotic Animal Disease in Great Britain and in Scotland Specifically between 1938 and 2007

    Microsoft Academic Search

    Onneile O. Peiso; Barend M. de C. Bronsvoort; Ian G. Handel; Victoriya V. Volkova

    2011-01-01

    BackgroundIncursions of contagious diseases of livestock into disease-free zones are inevitable as long as the diseases persist elsewhere in the world. Knowledge of where, when and how incursions have occurred helps assess the risks, and regionalize preventative and reactive measures.MethodologyBased on reports of British governmental veterinary services, we review occurrence of the former OIE List A diseases, and of Aujeszky's

  1. Distribution of cow-calf producers' beliefs about reporting cattle with clinical signs of foot-and-mouth disease to a veterinarian before or during a hypothetical outbreak.

    PubMed

    Delgado, Amy H; Norby, Bo; Scott, H Morgan; Dean, Wesley; McIntosh, W Alex; Bush, Eric

    2014-12-01

    Understanding the prevalence of cattle producers' beliefs regarding disease reporting can help officials improve surveillance programs with passive data collection. A cross-sectional survey was conducted in Texas in 2008 and 2009 to determine beliefs about reporting cattle with clinical signs consistent with foot-and-mouth disease (FMD) either prior to (scenario 1) or during an on-going outbreak of FMD (scenario 2). Two questionnaires were developed and distributed to Texas cow-calf producers in order to evaluate their behavioral, control, and normative beliefs related to disease reporting. The context for each behavior was provided through the use of scenarios, and belief strength was measured using a 7-point Likert-like scale. Beliefs were compared across scenarios and demographic categories, and the effect of scenario on belief examined using ordinal logistic regression. Respondents agreed that reporting clinically suspect cases would have positive economic and emotional consequences; however, when an outbreak was known to be present, producers were less likely to agree with many of the positive outcomes of reporting. Important barriers to disease reporting indicated by producers included a lack of knowledge related to clinical signs of highly contagious cattle diseases and which cattle are at risk of contracting FMD. In general, beliefs about barriers to reporting did not differ based on scenario. Veterinarians and regulatory authorities were the groups perceived to most strongly expect disease reporting, regardless of the scenario. Risk education for producers related to clinical signs of reportable livestock diseases, post-reporting procedures, and an understanding of FMD introduction and spread may improve the reporting of cattle with clinical signs consistent with FMD. PMID:25449736

  2. Swine vesicular disease, studies on pathogenesis, diagnosis, and epizootiology: A review

    Microsoft Academic Search

    A. Dekker

    2000-01-01

    Swine vesicular disease (SVD) is a contagious viral disease of swine. It causes vesicular lesions indistinguishable from those observed of foot?and?mouth disease. Infection with SVD virus (SVDV) can lead to viraemia within 1 day and can produce clinical signs 2 days after a pig has come into contact with infected pigs or a virus?contaminated environment. Virus can be detected 3.5

  3. Disease Detective

    NSDL National Science Digital Library

    2014-01-28

    This activity (on pages 35-43) lets learners analyze a "herd of elk" to detect the spread of a bacterial disease called brucellosis. The activity simulates how wildilfe veterinarians study elk in the wild by sampling only a subset of the animals. Based on a brucellosis problem with elk in Yellowstone National Park, learners cut out representations for two herds and then pick some at random to "test" for disease (denoted as a plus sign on a diseased animal). The results indicate that elk fed in Wyoming over the winter have more disease than the wild elk that go north to Montana

  4. Infectious Diseases

    NSDL National Science Digital Library

    NBC Learn

    2010-10-07

    With the threat of a warmer, wetter world and a larger global population, scientists are researching how climate change may impact the spread of infectious diseases,ťsuch as cholera and dengue fever, and how outbreaks may be prevented.ť "Changing Planet" is produced in partnership with the National Science Foundation.

  5. First isolation of Mycoplasma capricolum subsp. capricolum, one of the causal agents of caprine contagious agalactia, on the island of Lanzarote (Spain)

    Microsoft Academic Search

    C. De la Fe; A. Gutiérrez; J. B. Poveda; P. Assunçăo; A. S. Ramírez; F. Fabelo

    2007-01-01

    During an unusually long period of bad weather, several outbreaks of caprine contagious agalactia (CCA) were reported in a number of flocks on the island of Lanzarote (Canary Islands, Spain). Clinical and subclinical mastitis in lactating goats and some cases of arthritis and pneumonia in kids were observed in the affected flocks. Mycoplasma capricolum subsp. capricolum was isolated as the

  6. ConcepTest: Spreading Rate of Spreading Center

    NSDL National Science Digital Library

    Scientists collect rock samples of the oceanic crust from a location that is 10 km from a spreading center. (1 km = 1000 m; 1 m = 100 cm; 1 cm = 10 mm.) The sampled rocks were found to be 200,000 years old. What ...

  7. Detonation spreading in fine TATBs

    SciTech Connect

    Kennedy, J.E.; Lee, K.Y.; Spontarelli, T.; Stine, J.R.

    1998-12-31

    A test has been devised that permits rapid evaluation of the detonation-spreading (or corner-turning) properties of detonations in insensitive high explosives. The test utilizes a copper witness plate as the medium to capture performance data. Dent depth and shape in the copper are used as quantitative measures of the detonation output and spreading behavior. The merits of the test are that it is easy to perform with no dynamic instrumentation, and the test requires only a few grams of experimental explosive materials.

  8. Spectral and Spread Spectral Teleportation

    SciTech Connect

    Humble, Travis S [ORNL

    2010-01-01

    We report how quantum information encoded into the spectral degree of freedom of a single-photon state is teleported using a finite spectrally entangled biphoton state. We further demonstrate how the bandwidth of a teleported waveform can be controllably and coherently dilated using a spread spectral variant of teleportation. We present analytical fidelities for spectral and spread spectral teleportation when complex-valued Gaussian states are prepared using a proposed experimental approach, and we discuss the utility of these techniques for integrating broad-bandwidth photonic qubits with narrow-bandwidth receivers in quantum communication systems.

  9. Contagious yawning in domestic dog puppies (Canis lupus familiaris): the effect of ontogeny and emotional closeness on low-level imitation in dogs.

    PubMed

    Madsen, Elainie Alenkćr; Persson, Tomas

    2013-03-01

    Contagious yawning is a well-documented phenomenon in humans and has recently attracted much attention from developmental and comparative sciences. The function, development and underlying mechanisms of the phenomenon, however, remain largely unclear. Contagious yawning has been demonstrated in dogs and several non-human primate species, and theoretically and empirically associated with empathy in humans and non-human primates. Evidence of emotional closeness modulating contagious yawning in dogs has, nonetheless, been contradictory. Humans show a developmental increase in susceptibility to yawn contagion, with typically developing children displaying a substantial increase at the age of four, when a number of cognitive abilities (e.g. accurate identification of others' emotions) begin to clearly manifest. Explicit tests of yawn contagion in non-human animals have, however, thus far only involved adult individuals. Here, we report a study of the ontogeny of domestic dogs' (Canis lupus familiaris) susceptibility to yawn contagion, and whether emotional closeness to the yawning model affects this. Thirty-five dogs, aged 4-14 months, observed a familiar and unfamiliar human repeatedly yawn or gape. The dogs yawned contagiously, but emotional closeness with the model did not affect the strength of contagion, raising questions as to recent evidence of emotionally modulated auditory contagious yawning in dogs. The dogs showed a developmental effect, with only dogs above 7 months evidencing contagion. The results support the notion of a developmental increase in dogs' attention to others and identification of others' emotional states and suggest that yawn contagion is underpinned by developmental processes shared by humans and other animals. PMID:23076724

  10. Contagious Itch in Humans. A Study of Visual “Transmission” of Itch in Atopic Dermatitis and Healthy Subjects

    PubMed Central

    Papoiu, A.D.P.; Wang, H.; Coghill, R.C.; Chan, Y-H.; Yosipovitch, G.

    2011-01-01

    Anecdotal evidence suggests “contagious” itch occurs in daily life when we see other people itch and scratch. This phenomenon has not been systematically studied previously, and factors which can amplify itch perception were unknown. We investigated whether exposure to visual cues of itch can induce or intensify itch in healthy and atopic dermatitis subjects. Participants received histamine or a saline control delivered to the forearm and were asked to watch short video clips of people scratching. Spontaneous scratching induced by visual cues was monitored and analyzed. Atopic dermatitis patients reported a higher itch intensity and scratched more frequently while watching itch videos, even in the presence of mock itch stimuli. Human susceptibility to develop itch when exposed to visual cues is confirmed and it appears amplified in atopic dermatitis sufferers. These findings suggest that interpersonal social cues can dramatically alter the subjective sensory experience of itch. PMID:21410682

  11. Western blot analysis of virus-specific antibody responses for capripox and contagious pustular dermatitis viral infections in sheep.

    PubMed Central

    Chand, P.; Kitching, R. P.; Black, D. N.

    1994-01-01

    This paper reports the development and evaluation of serological tests for the differentiation of antibodies in animals infected with capripox and parapox viruses. Agar-gel immunodiffusion tests using sera from sheep with naturally-acquired infections and from sheep experimentally inoculated with orf or capripox viruses showed cross reactions. Virus-specific antibody responses to structural proteins of the viruses were analysed by Western-blot analysis. This analysis readily differentiated the infections as either capripox or contagious pustular dermatitis. The antibody responses to the 32 kDa and 26 kDa proteins of capripoxvirus provided a firm basis for differentiation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7925674

  12. Threshold Effects for Two Pathogens Spreading on a Network

    NASA Astrophysics Data System (ADS)

    Newman, M. E. J.

    2005-09-01

    Diseases spread through host populations over the networks of contacts between individuals and a number of results about this process have been derived in recent years by exploiting connections between epidemic processes and bond percolation on networks. Here we investigate the case of two pathogens in a single population, which has been the subject of recent interest among epidemiologists. We demonstrate that two pathogens competing for the same hosts can both spread through a population only for intermediate values of the bond occupation probability that lie above the classic epidemic threshold and below a second higher value, which we call the coexistence threshold, corresponding to a distinct topological phase transition in networked systems.

  13. Comparative assessment of two commonly used commercial ELISA tests for the serological diagnosis of contagious agalactia of small ruminants caused by Mycoplasma agalactiae

    PubMed Central

    2012-01-01

    Background Contagious agalactia (CA) of sheep and goats caused by Mycoplasma agalactiae is a widely occurring economically important disease that is difficult to control. The ELISA is commonly used for the serological detection of CA but it has some limitations and the performance of the available tests have not been properly evaluated. Two commercial ELISA kits are widely used, one involving a fusion protein as target antigen and the other a total antigen. The objectives were to compare these tests by evaluating: i. Their diagnostic sensitivity and specificity, the relevance of the recommended cut-off points, the correlation between the two tests, and, the correlation between serology data and the milk shedding of M. agalatiae; ii. The influence of extrinsic factors such as the targeted animal species, geographical origin of the samples, intra-specific variability of M. agalactiae and concurrent mycoplasma infections. A sample of 5900 animals from 211 farms with continuous CA monitoring for 20?years and no prior vaccination history was used. The infection status was known from prior bacteriological, epidemiological and serological monitoring with a complementary immunoblotting test. Results The average diagnostic sensitivity was 56% [51.8–59.8] for the fusion protein ELISA and 84% [81.3–87.2] for the total antigen ELISA, with noteworthy flock-related variations. The average diagnostic specificity for the fusion protein ELISA was 100% [99.9–100], and for the total antigen ELISA differed significantly between goats and sheep: 99.3% [97.4–99.9] and 95.7% [93.8–97.2] respectively. Experimental inoculations with different M. agalactiae strains revealed that the ELISA kits poorly detected the antibody response to certain strains. Furthermore, test performances varied according to the host species or geographical origin of the samples. Finally, the correlation between milk shedding of M. agalactiae and the presence of detectable antibodies in the blood was poor. Conclusions These serological tests are not interchangeable. The choice of a test will depend on the objectives (early detection of infection or disease control program), on the prevalence of infection and the control protocol used. Given the variety of factors that may influence performance, a preliminary assessment of the test in a given situation is recommended prior to widespread use. PMID:22776779

  14. Dynamic basis of volcanic spreading

    Microsoft Academic Search

    Andrea Borgia

    1994-01-01

    The established models of the structure and dynamics of a 'typical' Hawaiian volcano lead inevitably to a paradox: finite element viscoelastic calculations, using TECTON, predict that a compressional stress field should characterize their upper flanks; instead, extension is observed. The paradox is solved by postulating that volcanic evolution is determined by feedback processes of spreading of the geologic literature on

  15. Scaled experiments of volcanic spreading

    Microsoft Academic Search

    Olivier Merle; Andrea Borgia

    1996-01-01

    Experiments were conducted to study the spreading of volcanic constructs. Volcanoes are simulated by a sand cone, and the volcanic substratum is simulated by a sand layer (brittle substratum) overlying a silicone layer (ductile substratum). Similarity conditions between natural volcanoes and experimental prototypes led to the definition of dimensionless Pi numbers. Experiments determine Pi values which predict whether or not

  16. Direct sequence spread spectrum signalling

    Microsoft Academic Search

    A. K. Jain

    1978-01-01

    The problems encountered in the Direct Sequence Spread Spectrum coding for communication systems employing widely distributed radio elements, providing area coverage, using higher order modulation techniques, multiple data rates, and requiring multiple access are addressed. A simple baseband correlation model which is subsequently modified to allow baseband correlation of higher order modulations is presented. Suitable algorithms are developed to generate

  17. Prevent the Spread of Norovirus

    MedlinePLUS

    ... Outbreaks For Food Handlers: Norovirus and Working with Food Norovirus in Healthcare Settings , general information on norovirus and prevention in healthcare facilities Handwashing: Clean Hands Save Lives , hand- and water-related hygiene tips Six Tips to Help Prevent the Spread ...

  18. Communicating About Communicable Disease

    NSDL National Science Digital Library

    IBM& #39; s Teachers Try Science program

    2011-11-23

    In this "tried and true" investigation, students use a commercially available product (Glo-germ) and a blacklight to demonstrate how germs are spread. Glitter can be substituted. Students then write a public service announcement, including statistics, about the preventing the spread of a communicable disease.

  19. How Is Hodgkin Disease Diagnosed?

    MedlinePLUS

    ... Hodgkin disease spreading or coming back after treatment. Bone marrow aspiration and biopsy: These tests are not used ... to see if Hodgkin disease is in the bone marrow. They are described in more detail in the ...

  20. Pathways of lymphatic spread in gynecologic malignancies.

    PubMed

    Pańo, Blanca; Sebastiŕ, Carmen; Ripoll, Enric; Paredes, Pilar; Salvador, Rafael; Buńesch, Laura; Nicolau, Carlos

    2015-01-01

    Precise radiologic evaluation of regional adenopathic involvement in pelvic gynecologic tumors is fundamental to clinical practice because of its prognostic and therapeutic significance. Likewise, the identification of metastatic adenopathies at posttreatment imaging is essential for assessing response and detecting recurrence. Similar to urologic neoplasms, gynecologic neoplasms most often spread regionally to the pelvic and retroperitoneal lymph nodes, following the normal drainage pathways of the pelvic organs. Familiarity with routes of dissemination, treatment options, and means of analyzing lymph node characteristics is crucial to determine the extent of disease. Two staging systems can be used in characterizing gynecologic malignancies: the FIGO (International Federation of Gynecology and Obstetrics) system, which is the most commonly and universally used, and the TNM (tumor, node, metastasis) system, which is based on clinical and/or pathologic classification. Anatomic assessment with multidetector computed tomography (CT) and magnetic resonance (MR) imaging is still the most commonly used technique for the detection of lymph node spread, which is mainly based on morphologic criteria, the most important of which is nodal size. However, size has limited diagnostic specificity. Consequently, functional imaging techniques such as diffusion-weighted MR imaging, positron emission tomography combined with CT, lymphoscintigraphy, and sentinel lymph node mapping, which are based on molecular and physiologic activity and allow more precise evaluation, are often incorporated into diagnostic imaging protocols for staging of gynecologic malignancies. (©)RSNA, 2015. PMID:25969940

  1. This information sheet is for the care and use of Goats Potential Injury & Zoonotic Diseases: Goats are more

    E-print Network

    Wood, Marcelo A.

    of infection. Infected ruminants are usually asymptomatic. The rickettsia are shed in the urine, feces, milk and goats and orf in people. In ruminants, it is evidenced by exudative (draining) lesions found. In ruminants, the disease is highly contagious to humans and other animals. Infected sheep or goats

  2. This information sheet is for the care and use of Sheep Potential Injury and Zoonotic Diseases: Sheep are large domestic

    E-print Network

    Wood, Marcelo A.

    of infection. Infected ruminants are usually asymptomatic. The rickettsia is shed in the urine, feces, milk and goats, and orf in people. In ruminants, it is evidenced by exudative (oozing) lesions found. The disease in ruminants is contagious to humans and other animals. Infected sheep or goats are the source

  3. A model for multiseasonal spread of verticillium wilt of lettuce.

    PubMed

    Wu, B M; Subbarao, K V

    2014-09-01

    Verticillium wilt, caused by Verticillium dahliae, is a destructive disease in lettuce, and the pathogen is seedborne. Even though maximum seed infestation rates of <5% have been detected in commercial lettuce seed lots, it is necessary to establish acceptable contamination thresholds to prevent introduction and establishment of the pathogen in lettuce production fields. However, introduction of inoculum into lettuce fields for experimental purposes to determine its long term effects is undesirable. Therefore, we constructed a simulation model to study the spread of Verticillium wilt following pathogen introduction from seed. The model consists of four components: the first for simulating infection of host plants, the second for simulating reproduction of microsclerotia on diseased plants, the third for simulating the survival of microsclerotia, and the fourth for simulating the dispersal of microsclerotia. The simulation results demonstrated that the inoculum density-disease incidence curve parameters and the dispersal gradients affect disease spread in the field. Although a steep dispersal gradient facilitated the establishment of the disease in a new field with a low inoculum density, a long-tail gradient allowed microsclerotia to be dispersed over greater distances, promoting the disease spread in fields with high inoculum density. The simulation results also revealed the importance of avoiding successive lettuce crops in the same field, reducing survival rate of microsclerotia between crops, and the need for breeding resistance against V. dahliae in lettuce cultivars to lower the number of microsclerotia formed on each diseased plant. The simulation results, however, suggested that, even with a low seed infestation rate, the pathogen would eventually become established if susceptible lettuce cultivars were grown consecutively in the same field for many years. A threshold for seed infestation can be established only when two of the three drivers of the disease-(i) low microsclerotia production per diseased plant, (ii) long-tail dispersal gradient, and (iii) low microsclerotia survival between lettuce crops-are present. PMID:24624952

  4. Effects of internal fluctuations on the spreading of Hantavirus C. Escudero,1

    E-print Network

    Lindenberg, Katja

    Effects of internal fluctuations on the spreading of Hantavirus C. Escudero,1 J. Buceta,1,2, * F. J between out- breaks of the disease and seasonal changes was explored by Buceta et al. [6]. This collection

  5. Agricultural pathogen decontamination technology-reducing the threat of infectious agent spread

    Microsoft Academic Search

    Rita G. Betty; Jill Marie Bieker; Mark David Tucker

    2005-01-01

    Outbreaks of infectious agricultural diseases, whether natural occurring or introduced intentionally, could have catastrophic impacts on the U.S. economy. Examples of such agricultural pathogens include foot and mouth disease (FMD), avian influenza (AI), citrus canker, wheat and soy rust, etc. Current approaches to mitigate the spread of agricultural pathogens include quarantine, development of vaccines for animal diseases, and development of

  6. The Impact of Random Screening and Contact Tracing in Reducing the Spread of HIV

    E-print Network

    Hyman, James "Mac"

    on the spread of HIV and other sexually transmitted diseases by reducing the uncertainty in assessing the impact of the most e#11;ective methods used for controlling treatable sexually transmitted diseases, it is still in an initial highly infectious stage or in the late stages of the disease. In this model contact tracing

  7. The nationalization of a disease: a paradigm?

    PubMed Central

    Soviero, D J

    1986-01-01

    The early history of the Federal involvement in Hansen's Disease reflects the history of the Public Health Service itself. As a young and aggressive institution, the Public Health Service sought out contagious, infectious diseases that threatened the public health. National resources and national coordination were needed to fight the likes of malaria, hookworm, or smallpox. The customary attack would consist of a field study, determination of the etiology, the method of transmission, and, then, perhaps, preventive measures. An eradication campaign would follow. Leprosy fit perfectly into the model--a disease of unknown etiology, an unknown method of transmission, thought to be highly contagious, and no known cure. The United States launched a major investigation in Hawaii, where the disease was prevalent and its victims conveniently segregated. The investigation failed. The Public Health Service then turned toward segregation and isolation as a way to fulfill its public health role. A bureaucracy was established around the idea that victims of leprosy must be incarcerated for the good of the public. The institutionalization of the Public Health Service and the philosophy upon which its treatment of leprosy was based proved difficult to change when researchers in the field made major scientific breakthroughs in the 1940s. The realization that the disease was only feebly contagious, activities of patient organizations, and pressure from the media and the Congress did not achieve as dramatic results as the sulfone drugs did. The Public Health Service moved, but slowly. What are the lessons in all of this?. Images p401-a p402-a p403-a PMID:3090606

  8. Epidemics of emerging animal diseases and food-borne infection problems over the last 5 years in Japan.

    PubMed

    Yamane, Itsuro

    2006-10-01

    There have been several emerging animal diseases and food-borne infection problems occurring in Japan over the last 5 years. We describe brief pictures of these epidemics and our control activities. As acute contagious and/or emerging animal diseases, the foot and mouth disease (FMD) outbreak caused by the Pan-Asian topotype of the type O virus occurred in March 2000 after 92 years of FMD-free status. In 2004, four cases of the highly pathogenic avian influenza (HPAI), which was the first outbreak after 79 years, and caused by the H5N1 subtype, were identified. As part of the responses against these outbreaks, all the animals in the affected farms were destroyed, and movement control areas were established around the infected premises, and a nation-wide intensive survey for FMD and HPAI was performed. As for food-borne or feed-borne infections, the first bovine spongiform encephalopathy (BSE) was identified in September 2001 and 19 more cases have been reported until June 2005. A large outbreak of food-borne infection caused by low-fat milk contaminated with enterotoxin A produced by Staphylococcus aureus, involving more than 13,000 patients, occurred in 2000. In 2003, people who consumed uncooked liver and meat from wild boar and deer developed clinical signs of hepatitis caused by the hepatitis E virus. Pork is also suspected as natural source of virus transmission. Early detection of the first cases and rapid action in preventing and controlling the spread of infections are very important combined with proper risk communication about correct information of the diseases. PMID:17135492

  9. Lyme Disease Transmission

    MedlinePLUS

    ... bite of infected ticks. The blacklegged tick (or deer tick, Ixodes scapularis ) spreads the disease in the ... cook meat thoroughly. Note that hunting and dressing deer or squirrels may bring you into close contact ...

  10. Hydroclimatological And Anthropogenic Drivers For Cholera Spreading

    NASA Astrophysics Data System (ADS)

    Righetto, Lorenzo; Bertuzzo, Enrico; Mari, Lorenzo; Casagrandi, Renato; Gatto, Marino; Rinaldo, Andrea

    2010-05-01

    The nature of waterborne diseases, among which cholera has a prominent importance, calls for a better understanding of the link between epidemic spreading, water and climate. To this end, we have developed a framework which involves a network-based description of a river system, connected with local communities which act as nodes of the network. This has allowed us to produce consistent simulations of real case studies. More recent investigations comprise the evaluation of the spreading velocity of an epidemic wave by means of a reaction-diffusion modeling approach. In particular, we have found that both transport processes and epidemiological quantities, such as the basic reproduction number, have a crucial effect in controlling the spreading of the epidemics. We first developed a description of bacterial movement along the network driven by advection and diffusion; afterward, we have included the movement of human populations. This latter model allowed us to establish the conditions that can trigger epidemic waves that start from the coastal region, where bacteria are autochthonous, and travel inland. In particular, our findings suggest that even relatively low values of human diffusion can have the epidemic propagate upstream. The interaction between climate, hydrology and epidemic events is still much debated, since no clear correlation between climatologic and epidemiological phenomena has emerged so far. However, a spatial assessment of hydrological and epidemiological mechanisms could be crucial to understand the evolution of cholera outbreaks. In particular, a hotly debated topic is the understanding of the mechanisms that can generate patterns of cholera incidence that exhibit an intra-annual double peak, as frequently observed in endemic region such as Bangladesh. One of the possible explanations proposed in the literature is that spring droughts cause bacteria concentration in water to rise dramatically, triggering the first peak. On the other hand similar mechanisms can occur during flood recessions in autumn together with major water sanitation system failures and higher population density. We show here the results of an ecohydrological model that couples the dynamics of the disease to a description of both the local water reservoir and of the local river section. The goal of this modeling exercise is to reproduce and understand the mechanisms behind intra-annual cholera incidence dynamics driven by hydrologic variability.

  11. Molecular cloning, expression and immunological analysis of the capsid precursor polypeptide (P1) from swine vesicular disease virus

    Microsoft Academic Search

    Miguel A Jiménez-Clavero; Estela Escribano-Romero; José M Sánchez-Vizca??no; Victoria Ley

    1998-01-01

    Swine vesicular disease virus (SVDV) is the aetiological agent of a highly contagious viral disease of pigs, whose symptoms are indistinguishable from those caused by foot-and-mouth disease virus (FMDV). The gene coding for the capsid protein precursor of SVDV (P1) from a recent spanish isolate (SPA\\/1\\/'93) was cloned and expressed in bacteria, and the antigenicity and immunogenicity of the recombinant

  12. Quantum spread spectrum multiple access

    E-print Network

    Juan Carlos Garcia-Escartin; Pedro Chamorro-Posada

    2014-11-27

    We describe a quantum multiple access scheme that can take separate single photon channels and combine them in the same path. We propose an add-drop multiplexer that can insert or extract a single photon into an optical fibre carrying the qubits of all the other users. The system follows the principle of code division multiple access, a spread spectrum technique widely used in cellular networks.

  13. Secure Health Data Linkage and Geocoding: Current Approaches and Research Directions

    E-print Network

    Christen, Peter

    , in crime and fraud detection, and in the assembly of terrorism intelligence [18]. Corresponding author #12 dealing with outbreaks of rapidly spreading contagious diseases, or when investigating (bio-) terrorism

  14. Geodynamic environments of ultra-slow spreading

    NASA Astrophysics Data System (ADS)

    Kokhan, Andrey; Dubinin, Evgeny

    2015-04-01

    Ultra-slow spreading is clearly distinguished as an outstanding type of crustal accretion by recent studies. Spreading ridges with ultra-slow velocities of extension are studied rather well. But ultra-slow spreading is characteristic feature of not only spreading ridges, it can be observed also on convergent and transform plate boundaries. Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on divergent plate boundaries: 1. On spreading ridges with ultra-slow spreading, both modern (f.e. Gakkel, South-West Indian, Aden spreading center) and ceased (Labrador spreading center, Aegir ridge); 2. During transition from continental rifting to early stages of oceanic spreading (all spreading ridges during incipient stages of their formation); 3. During incipient stages of formation of spreading ridges on oceanic crust as a result of ridge jumps and reorganization of plate boundaries (f.e. Mathematicians rise and East Pacific rise); 4. During propagation of spreading ridge into the continental crust under influence of hotspot (Aden spreading center and Afar triple junction), under presence of strike-slip faults preceding propagation (possibly, rift zone of California Bay). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on transform plate boundaries: 1. In transit zones between two "typical" spreading ridges (f.e. Knipovich ridge); 2. In semi strike-slip/extension zones on the oceanic crust (f.e. American-Antarctic ridge); 3. In the zones of local extension in regional strike-slip areas in pull-apart basins along transform boundaries (Cayman trough, pull-apart basins of the southern border of Scotia plate). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on convergent plate boundaries: 1. During back-arc rifting on the stage of transition into back-arc spreading (central part of Bransfield rift); 2. During back-arc inter-subduction spreading (Ayu trough, northern Fiji basin), 3. During diffuse back-arc spreading (area on the south-eastern border of Scotia sea), 4. During back-arc spreading under splitting of island arc (northern extremity of Mariana trough). Each of the geodynamic environments is characterized by peculiar topographic, geological and geophysical features forming under the same spreading velocities. Development of ultra-slow spreading in each of these environments results in formation of peculiar extension sedimentary basins.

  15. Possible spread of African horse sickness on the wind.

    PubMed

    Pedgley, D E; Tucker, M R

    1977-10-01

    Analyses of outbreaks of African horse sickness showed that movement of infected Culicoides midges on the wind was most likely responsible for the spread of the disease over the sea from Morocco to Spain in 1966, from Turkey to Cyprus in 1960, and from Senegal to the Cape Verde Islands in 1943. The pattern of spread of the epidemic in the Middle East in 1960 could have been laid down by the infected midges carried on spells of south-east winds, and analyses of outbreaks in Algeria in 1965 and India in 1960 also suggested windborne spread of the disease. Each spread occurred when the presence of virus, host and vector coincided either with a spell of winds unusual for a particular time of year (Spain, Cyprus, Cape Verde Islands and Algeria) or with a series of disturbances usual at that time of the year (Middle East and India). Inferred flight endurance of the midge varied up to at least 20 h and flight range from 40 to 700 km. Flight occurred when temperatures were likely to have been in the range of 15-25 degrees C if it was at night or 20 to about 40 degrees C if it was by day.It is suggested that likely movements of midges on the wind can be estimated from synoptic weather charts, and should be taken into account when planning control of the disease in the face of an outbreak. Such control includes a ban on movement of horses, vaccination and spraying of insecticide.The risk of spread to countries outside the endemic areas should be assessed by reference to possible wind dispersal of infected midges. PMID:269203

  16. Possible spread of African horse sickness on the wind

    PubMed Central

    Sellers, R. F.; Pedgley, D. E.; Tucker, M. R.

    1977-01-01

    Analyses of outbreaks of African horse sickness showed that movement of infected Culicoides midges on the wind was most likely responsible for the spread of the disease over the sea from Morocco to Spain in 1966, from Turkey to Cyprus in 1960, and from Senegal to the Cape Verde Islands in 1943. The pattern of spread of the epidemic in the Middle East in 1960 could have been laid down by the infected midges carried on spells of south-east winds, and analyses of outbreaks in Algeria in 1965 and India in 1960 also suggested windborne spread of the disease. Each spread occurred when the presence of virus, host and vector coincided either with a spell of winds unusual for a particular time of year (Spain, Cyprus, Cape Verde Islands and Algeria) or with a series of disturbances usual at that time of the year (Middle East and India). Inferred flight endurance of the midge varied up to at least 20 h and flight range from 40 to 700 km. Flight occurred when temperatures were likely to have been in the range of 15-25 °C if it was at night or 20 to about 40 °C if it was by day. It is suggested that likely movements of midges on the wind can be estimated from synoptic weather charts, and should be taken into account when planning control of the disease in the face of an outbreak. Such control includes a ban on movement of horses, vaccination and spraying of insecticide. The risk of spread to countries outside the endemic areas should be assessed by reference to possible wind dispersal of infected midges. PMID:269203

  17. Genetic evolution of Mycoplasma capricolum subsp. capripneumoniae strains and molecular epidemiology of contagious caprine pleuropneumonia by sequencing of locus H2.

    PubMed

    Lorenzon, S; Wesonga, H; Ygesu, Laikemariam; Tekleghiorgis, Tesfaalem; Maikano, Y; Angaya, M; Hendrikx, P; Thiaucourt, F

    2002-03-01

    Contagious caprine pleuropneumonia (CCPP) is a major threat to goat farming in developing countries. Its exact distribution is not well known, despite the fact that new diagnostic tools such as PCR and competitive ELISA are now available. The authors developed a study of the molecular epidemiology of the disease, based on the amplification of a 2400 bp long fragment containing two duplicated gene coding for a putative membrane protein. The sequence of this fragment, obtained on 19 Mycoplasma capricolum subsp. capripneumoniae (Mccp) strains from various geographical locations, gave 11 polymorphic positions. The three mutations found on gene H2prim were silent and did not appear to induce any amino acid modifications in the putative translated protein. The second gene may be a pseudogene not translated in vivo, as it bore a deletion of the ATG codon found in the other members of the "Mycoplasma mycoides cluster" and as the six mutations evidenced in the Mccp strains would induce modifications in the translated amino acids. In addition, an Mccp strain isolated in the United Arab Emirates showed a deletion of the whole pseudogene, a further indication that this gene is not compulsory for mycoplasma growth. Four lineages were defined, based on the nucleotide sequence. These correlated relatively well with the geographical origin of the strains: North, Central or East Africa. The strain of Turkish origin had a sequence similar to that found in North African strains, while strains isolated in Oman had sequences similar to those of North or East African strains. The latter is possibly due to the regular import of goats of various origins. Similar molecular epidemiology tools have been developed by sequencing the two operons of the 16S rRNA gene or by AFLP. All these various techniques give complementary results. One (16S rRNA) offers the likelihood of a finer identification of strains circulating in a region, another (H2) of determining the geographical origin of the strains. These tools can make a very useful contribution to understanding the epidemiology of CCPP. PMID:11844618

  18. A stochastic predictive model for the natural spread of bluetongue.

    PubMed

    Ducheyne, Els; Lange, Martin; Van der Stede, Yves; Meroc, Estelle; Durand, Benoit; Hendrickx, Guy

    2011-04-01

    In recent years the vector-borne diseases (VBD) are (re)-emerging and spreading across the world having a profound impact on human and veterinary health, ecology, socio-economics and disease management. Arguably the best-documented example of veterinary importance is the recent twofold invasion of bluetongue (BT) in Europe. Much attention has been devoted to derive presence-absence habitat distribution models and to model transmission through direct contact. Limited research has focused on the dynamic modelling of wind mediated BT spread. This paper shows the results of a stochastic predictive model used to assess the spread of bluetongue by vectors considering both wind-independent and wind-mediated movement of the vectors. The model was parameterised using epidemiological knowledge from the BTV8 epidemic in 2006/2007 and the BTV1 epidemic in 2008 in South-France. The model correctly reflects the total surface of the infected zone (overall accuracy=0.77; sensitivity=0.94; specificity=0.65) whilst slightly overestimating spatial case density. The model was used operationally in spring 2009 to predict further spread of BTV1. This allowed veterinary officers in Belgium to decide whether there was a risk of introduction of BTV1 from France into Belgium and thus, whether there was a need for vaccination. Given the far distance from the predicted infected zone to the Belgian border, it was decided not to vaccinate against BTV1 in 2009 in Belgium. PMID:21300413

  19. Development and Evaluation of an in ovo Plasmid DNA Vaccine Against Infectious Bursal Disease Virus

    Microsoft Academic Search

    L. Moura; M. Liu; V. N. Vakharia

    2007-01-01

    Infectious Bursal Disease Virus (IBDV) is a highly contagious disease of chickens, which is controlled by live and inactivated vaccines. In this study, we evaluated a novel approach to vaccinate chickens against IBDV using DNA vaccinology. Plasmid DNA was administered in ovo to 18-day-old embryos. The DNA vaccine expresses the polyprotein VP2-VP4-VP3 of IBDV. The VP2 gene expresses epitopes of

  20. Developments in diagnostic techniques for differentiating infection from vaccination in foot-and-mouth disease

    Microsoft Academic Search

    Alfonso Clavijo; Peter Wright; Paul Kitching

    2004-01-01

    Foot-and-mouth disease (FMD) is a highly contagious and economically significant disease of cattle, pigs, sheep, goats and wild ruminant species. The FMD virus genome encodes a unique polyprotein from which the different viral polypeptides are cleaved by viral proteases, including eight different non-structural proteins (NSPs). Both structural and non-structural antigens induce the production of antibodies in infected animals. In contrast,

  1. Multicarrier Spread Spectrum for Covert Acoustic Communications

    E-print Network

    Langendoen, Koen

    other modulations, direct-sequence spread spectrum and orthogonal frequency-division multiplexing of the project three candidates have been consid- ered: direct-sequence spread-spectrum (DSSS, [1]), orthogonal

  2. Wet climate and transportation routes accelerate spread of human plague.

    PubMed

    Xu, Lei; Stige, Leif Chr; Kausrud, Kyrre Linné; Ben Ari, Tamara; Wang, Shuchun; Fang, Xiye; Schmid, Boris V; Liu, Qiyong; Stenseth, Nils Chr; Zhang, Zhibin

    2014-04-01

    Currently, large-scale transmissions of infectious diseases are becoming more closely associated with accelerated globalization and climate change, but quantitative analyses are still rare. By using an extensive dataset consisting of date and location of cases for the third plague pandemic from 1772 to 1964 in China and a novel method (nearest neighbour approach) which deals with both short- and long-distance transmissions, we found the presence of major roads, rivers and coastline accelerated the spread of plague and shaped the transmission patterns. We found that plague spread velocity was positively associated with wet conditions (measured by an index of drought and flood events) in China, probably due to flood-driven transmission by people or rodents. Our study provides new insights on transmission patterns and possible mechanisms behind variability in transmission speed, with implications for prevention and control measures. The methodology may also be applicable to studies of disease dynamics or species movement in other systems. PMID:24523275

  3. Dry spreading of polymer solutions M. Boudoussier

    E-print Network

    Boyer, Edmond

    445 Dry spreading of polymer solutions M. Boudoussier Collčge de France, Physique de la Matičre is good and is non-volatile (dry spreading) and b) the polymer does not adsorb on either interface (solid/liquid and liquid/air). The polymer solute has two main effects : a) it modifies the spreading coefficient

  4. Modeling the Spread of Active Worms

    Microsoft Academic Search

    Zesheng Chen; Lixin Gao; Kevin A. Kwiat

    2003-01-01

    Active worms spread in an automated fashion and can flood the Internet in a very short time. Modeling the spread of active worms can help us understand how active worms spread, and how we can monitor and defend against the propagation of worms effectively. In this paper, we present a mathematical model, referred to as the Analytical Active Worm Propagation

  5. Spread Spectrum Watermarking: Malicious Attacks and Counterattacks

    Microsoft Academic Search

    Frank Hartung; Jonathan K. Su

    1999-01-01

    Most watermarking methods for images and video have been proposed are based on ideas from spread spectrumradio communications, namely additive embedding of a (signal adaptive or non-adaptive) pseudo-noise watermarkpattern, and watermark recovery by correlation. Even methods that are not presented as spread spectrum methodsoften build on these principles. Recently, some scepticism about the robustness of spread spectrum watermarks hasarisen, specifically

  6. Eliminating Long-Distance Consonantal Spreading

    Microsoft Academic Search

    Diamandis Gafos

    1998-01-01

    Past theoretical analyses have claimed that some languages employ a special type of phonological spreading of a consonant over a vowel, long-distance consonantal spreading. I argue that this type of spreading can and must be eliminated from the theory, by reducing it to segmental copying as in reduplication. This elimination is first motivated from a number of perspectives, including considerations

  7. Coded Random CDMA with Partitioned Spreading

    Microsoft Academic Search

    Lukasz Krzymien; Dmitri Truhachev; Christian Schlegel

    A Code Division Multiple Access (CDMA) system is considered, where a number of concurrent users, distin- guished by random spreading waveforms, access the common additive white Gaussian noise (AWGN) channel. All users employ a regular low-density parity-check (LDPC) error con- trol code (ECC). Additionally, a method, called Partitioned Spreading (PS) is used. Each user's spreading waveform is divided into M

  8. The prevalence of antibody of antibody to contagious caprine pleuropneumonia (Mycoplasma strain F38) in some wild herbivores and camels in Kenya.

    PubMed

    Paling, R W; Macowan, K J; Karstad, L

    1978-07-01

    Sera of 11 species of wild herbivores were tested for antibody to Mycoplasma strain F38 which causes contagious caprine pleuropneumonia (CCPP) in Kenya. Antibodies were found in buffalo (Syncerus caffer) (32%), impala (Aepyceros melampus) (10%) and camels (Camelus dromedarius) (49%) but not in bushbuck (Tragelaphus scriptus), eland (Taurotragus oryx), Grant's gazelle (Gazella granti), kongoni (Alcelaphus buselaphus cokei), oryx (Oryx beisa), Thomson's gazelle (Gazella thomsonii), waterbuck (Kobus defassa) and wildebeest (Connochaetus taurinus). PMID:691121

  9. An adenovirus vectored mucosal adjuvant augments protection of mice immunized intranasally with an adenovirus-vectored foot-and-mouth disease virus subunit vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen that causes severe morbidity and economic losses to the livestock industry in many countries. The oral and respiratory mucosae are the main ports of entry of FMDV, so the stimulation of local immunity in these tissues may help preve...

  10. The role of veterinary epidemiology in combating infectious animal diseases on a global scale: The impact of training and outreach programs

    Microsoft Academic Search

    M. D. Salman

    2009-01-01

    The effectiveness of detection and control of highly contagious animal diseases is dependent on a solid understanding of their nature and implementation of scientifically sound methods by people who are well trained. The implementation of specific detection methods and tools requires training and application in natural as well as field conditions. The aim of this paper is to present the

  11. The foot and mouth disease network in the southern cone of South America: an example of regional governance.

    PubMed

    Corrales Irrazábal, H A

    2012-08-01

    The fact that foot and mouth disease is highly contagious, easily spread and of major commercial importance makes it a redoubtable challenge for animal health in South American countries and the world over. A number of factors impact directly on the effectiveness of national programmes to eradicate foot and mouth disease. Therefore, in order to meet the challenges posed by today's globalised world, it is of the utmost importance that national level eradication programmes be considered state policies and that they be the subject of broad political agreement at the highest level and consolidated as regional programmes between national Veterinary Services. The programmes, agreements and technical cooperation projects established jointly by Member Countries of the Southern Common Market (MERCOSUR) were a key factor in building management capacity to control foot and mouth disease in the area. Another key factor has been a partnership with one of the most sensitive sectors--the private production sector. Its active and responsible participation in operational functions has done much to strengthen and ensure the competitive development of South American countries and consolidate their role as global beef exporters. However, to prevent further outbreaks it is essential to maintain and reinforce the structure of national programmes and to have strong and highly trained Veterinary Services and sufficient funding to ensure efficient and sustainable plans. These plans must enable Veterinary Services, by means of good governance, to implement effective measures in the areas of animal health and international trade in animals and animal products/by-products, thereby achieving rapid and more equitable social and economic development. PMID:23413740

  12. Bridging a yawning chasm: EEG investigations into the debate concerning the role of the human mirror neuron system in contagious yawning.

    PubMed

    Cooper, Nicholas R; Puzzo, Ignazio; Pawley, Adam D; Bowes-Mulligan, Ruby A; Kirkpatrick, Emma V; Antoniou, Pavlina A; Kennett, Steffan

    2012-06-01

    Ongoing debate in the literature concerns whether there is a link between contagious yawning and the human mirror neuron system (hMNS). One way of examining this issue is with the use of the electroencephalogram (EEG) to measure changes in mu activation during the observation of yawns. Mu oscillations are seen in the alpha bandwidth of the EEG (8-12 Hz) over sensorimotor areas. Previous work has shown that mu suppression is a useful index of hMNS activation and is sensitive to individual differences in empathy. In two experiments, we presented participants with videos of either people yawning or control stimuli. We found greater mu suppression for yawns than for controls over right motor and premotor areas, particularly for those scoring higher on traits of empathy. In a third experiment, auditory recordings of yawns were compared against electronically scrambled versions of the same yawns. We observed greater mu suppression for yawns than for the controls over right lateral premotor areas. Again, these findings were driven by those scoring highly on empathy. The results from these experiments support the notion that the hMNS is involved in contagious yawning, emphasise the link between contagious yawning and empathy, and stress the importance of good control stimuli. PMID:22198677

  13. Using a Bear Put Spread 

    E-print Network

    Bevers, Stan; Amosson, Stephen H.; Waller, Mark L.; Dhuyvetter, Kevin C.

    2008-10-07

    a bear put spread. In this example, assume the current Chicago Board of Trade December Corn contract is trad- ing at $6.00 per bushel. The associated December put option premiums are listed in Table 1. The producer begins the strategy by buying a... put op- tion near the money, in this case a $6.00 put op- tion for $0.90 per bushel ($4,500 per 5,000-bushel contract). At the same time, he also writes (sells) a put option with a strike price below the put option. In our example, he writes a $5...

  14. Hybrid spread spectrum radio system

    DOEpatents

    Smith, Stephen F. (London, TN); Dress, William B. (Camas, WA)

    2010-02-02

    Systems and methods are described for hybrid spread spectrum radio systems. A method includes modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control an amplification circuit that provides a gain to the signal. Another method includes: modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control a fast hopping frequency synthesizer; and fast frequency hopping the signal with the fast hopping frequency synthesizer, wherein multiple frequency hops occur within a single data-bit time.

  15. Modeling the Geographic Spread of Rabies in China

    PubMed Central

    Chen, Jing; Zou, Lan; Jin, Zhen; Ruan, Shigui

    2015-01-01

    In order to investigate how the movement of dogs affects the geographically inter-provincial spread of rabies in Mainland China, we propose a multi-patch model to describe the transmission dynamics of rabies between dogs and humans, in which each province is regarded as a patch. In each patch the submodel consists of susceptible, exposed, infectious, and vaccinated subpopulations of both dogs and humans and describes the spread of rabies among dogs and from infectious dogs to humans. The existence of the disease-free equilibrium is discussed, the basic reproduction number is calculated, and the effect of moving rates of dogs between patches on the basic reproduction number is studied. To investigate the rabies virus clades lineages, the two-patch submodel is used to simulate the human rabies data from Guizhou and Guangxi, Hebei and Fujian, and Sichuan and Shaanxi, respectively. It is found that the basic reproduction number of the two-patch model could be larger than one even if the isolated basic reproduction number of each patch is less than one. This indicates that the immigration of dogs may make the disease endemic even if the disease dies out in each isolated patch when there is no immigration. In order to reduce and prevent geographical spread of rabies in China, our results suggest that the management of dog markets and trades needs to be regulated, and transportation of dogs has to be better monitored and under constant surveillance. PMID:26020234

  16. Tan F. Wong: Spread Spectrum & CDMA CHAPTER 0. OVERVIEW 0.1 What is spread spectrum?

    E-print Network

    Wong, Tan F.

    (direct sequence, frequency hop, and time hop) 3. Introduction to spread spectrum applications 4Tan F. Wong: Spread Spectrum & CDMA CHAPTER 0. OVERVIEW Chapter 0 Overview 0.1 What is spread spectrum? Spread spectrum: A modulation technique that produces a spectrum for the transmitted signal much

  17. Seroprevalence of contagious caprine pleuropneumonia in Kefta Humera, Alamata (Tigray) and Aba-'ala (Afar), Northern Ethiopia.

    PubMed

    Hadush, Birhanu; Eshetu, Lisanework; Mengistu, Wubishet; Hailesilassie, Mekonnen

    2009-06-01

    A cross sectional study was conducted to determine the sero-prevalence of contagious caprine pleuroneumonia in three districts of Tigray and Afar regions of Ethiopia namely; Kefta Humera, Alamata and Aba-'alla. Proportions and chi-square test statistics were used to analyze the data. From a total of 863 goats and 137 sheep tested, 282 (32.68%) and 25 (18.25%) were positive for antibodies of Mycoplasma capricolum subsp. capripneumoniae respectively using complement fixation test (CFT). The seroprevalence of CCPP in goats among the three districts was statistically significant (x(2) = 76.00, p < 0.001). In this study there was no statistical significant variation in the seroprevalence of CCPP in both sexes (x(2) = 3.619, p = 0.0571) and age (x(2) = 0.990, p = 0.095) groups. The finding of high seroprevalence of CCPP in sheep (18.25%) could indicate that sheep are potential carriers of Mccp. PMID:18989743

  18. Structural processes at slow-spreading ridges.

    PubMed

    Mutter, J C; Karson, J A

    1992-07-31

    Slow-spreading (<35 millimeters per year) mid-ocean ridges are dominated by segmented, asymmetric, rifted depressions like continental rifts. Fast-spreading ridges display symmetric, elevated volcanic edifices that vary in shape and size along axis. Deep earthquakes, major normal faults, and exposures of lower crustal rocks are common only along slow-spreading ridges. These contrasting features suggest that mechanical deformation is far more important in crustal formation at slow-spreading ridges than at fast-spreading ridges. New seismic images suggest that the nature and scale of segmentation of slow-spreading ridges is integral to the deformational process and not to magmatic processes that may control segmentation on fast-spreading ridges. PMID:17740729

  19. Effects of internal fluctuations on the spreading of Hantavirus.

    PubMed

    Escudero, C; Buceta, J; de la Rubia, F J; Lindenberg, Katja

    2004-12-01

    We study the spread of Hantavirus over a host population of deer mice using a population dynamics model. We show that taking into account the internal fluctuations in the mouse population due to its discrete character strongly alters the behavior of the system. In addition to the familiar transition present in the deterministic model, the inclusion of internal fluctuations leads to the emergence of an additional deterministically hidden transition. We determine parameter values that lead to maximal propagation of the disease and discuss some implications for disease prevention policies. PMID:15697402

  20. Spreading code protocols for distributed spread-spectrum packet radio networks

    Microsoft Academic Search

    E. S. Sousa; J. A. Silvester

    1988-01-01

    Spreading code protocols for a distributed spread-spectrum packet radio network are presented. A distributed single-hop system (i.e. each terminal can hear all other terminals) with the users approximately synchronized and a set of prespecified spreading codes are presented. The spreading code protocol is a policy for choosing a spreading code to be used, given that a terminal has a packet

  1. A combination of improved differential and global RNA-seq reveals pervasive transcription initiation and events in all stages of the life-cycle of functional RNAs in Propionibacterium acnes, a major contributor to wide-spread human disease

    PubMed Central

    2013-01-01

    Background Sequencing of the genome of Propionibacterium acnes produced a catalogue of genes many of which enable this organism to colonise skin and survive exposure to the elements. Despite this platform, there was little understanding of the gene regulation that gives rise to an organism that has a major impact on human health and wellbeing and causes infections beyond the skin. To address this situation, we have undertaken a genome–wide study of gene regulation using a combination of improved differential and global RNA-sequencing and an analytical approach that takes into account the inherent noise within the data. Results We have produced nucleotide-resolution transcriptome maps that identify and differentiate sites of transcription initiation from sites of stable RNA processing and mRNA cleavage. Moreover, analysis of these maps provides strong evidence for ‘pervasive’ transcription and shows that contrary to initial indications it is not biased towards the production of antisense RNAs. In addition, the maps reveal an extensive array of riboswitches, leaderless mRNAs and small non-protein-coding RNAs alongside vegetative promoters and post-transcriptional events, which includes unusual tRNA processing. The identification of such features will inform models of complex gene regulation, as illustrated here for ribonucleotide reductases and a potential quorum-sensing, two-component system. Conclusions The approach described here, which is transferable to any bacterial species, has produced a step increase in whole-cell knowledge of gene regulation in P. acnes. Continued expansion of our maps to include transcription associated with different growth conditions and genetic backgrounds will provide a new platform from which to computationally model the gene expression that determines the physiology of P. acnes and its role in human disease. PMID:24034785

  2. A spread willingness computing-based information dissemination model.

    PubMed

    Huang, Haojing; Cui, Zhiming; Zhang, Shukui

    2014-01-01

    This paper constructs a kind of spread willingness computing based on information dissemination model for social network. The model takes into account the impact of node degree and dissemination mechanism, combined with the complex network theory and dynamics of infectious diseases, and further establishes the dynamical evolution equations. Equations characterize the evolutionary relationship between different types of nodes with time. The spread willingness computing contains three factors which have impact on user's spread behavior: strength of the relationship between the nodes, views identity, and frequency of contact. Simulation results show that different degrees of nodes show the same trend in the network, and even if the degree of node is very small, there is likelihood of a large area of information dissemination. The weaker the relationship between nodes, the higher probability of views selection and the higher the frequency of contact with information so that information spreads rapidly and leads to a wide range of dissemination. As the dissemination probability and immune probability change, the speed of information dissemination is also changing accordingly. The studies meet social networking features and can help to master the behavior of users and understand and analyze characteristics of information dissemination in social network. PMID:25110738

  3. EpiMap: towards quantifying contact networks and modelling the spread of infections in developing countries

    Microsoft Academic Search

    Eiko Yoneki; Jon Crowcroft

    2011-01-01

    We describe the EpiMap project, in which mobile phones and sensors record the proximity of other devices, to gather information on human interactions within the rural communities of developing countries. Collected information will be used to develop improved mathematical models of the spread of infectious diseases, such as measles, tuberculosis and pneumococcal diseases. Modelling will be complemented by the use

  4. Control of contagious bovine pleuropneumonia: Knowledge, attitudes, perceptions and practices in Narok district of Kenya

    PubMed Central

    Kairu-Wanyoike, S.W.; Kiara, H.; Heffernan, C.; Kaitibie, S.; Gitau, G.K.; McKeever, D.; Taylor, N.M.

    2014-01-01

    CBPP is an important transboundary disease in sub-Saharan Africa whose control is urgent. Participatory data collection involving 52 focus group discussions in 37 village clusters and key informant interviews, a cross-sectional study involving 232 households and a post-vaccination follow up involving 203 households was carried out in 2006–2007 in Narok South district of Kenya. This was to investigate knowledge, attitudes, perceptions and practices (KAPP) associated with control of CBPP as well as the adverse post-vaccination reactions in animals in order to advice the control policy. The community perceived trans-boundary CBPP threat to their cattle. They had traditional disease coping mechanisms and were conversant with CBPP prevention and control with 49.8% (95%CI: 42.8–56.7%) giving priority to CBPP control. However, 12.9% (95%CI: 9.0–18.1%) of pastoralists had no knowledge of any prevention method and 10.0% (95%CI: 6.5–14.7%) would not know what to do or would do nothing in the event of an outbreak. Although 43.5% (95%CI: 37.1–50.2%) of pastoralists were treating CBPP cases with antimicrobials, 62.5% (95%CI: 52.1–71.7%) of them doubted the effectiveness of the treatments. Pastoralists perceived vaccination to be the solution to CBPP but vaccination was irregular due to unavailability of the vaccine. Vaccination was mainly to control outbreaks rather than preventive and exhibited adverse post-vaccination reactions among 70.4% (95%CI: 63.6–76.5%) of herds and 3.8% (95%CI: 3.5–4.2%) of animals. Consequently, nearly 25.2% (95%CI: 18.5–33.2%) of pastoralists may resist subsequent vaccinations against CBPP. Pastoralists preferred CBPP vaccination at certain times of the year and that it is combined with other vaccinations. In conclusion, pastoralists were not fully aware of the preventive measures and interventions and post-vaccination reactions may discourage subsequent CBPP vaccinations. Consequently there is need for monitoring and management of post vaccination reactions and awareness creation on CBPP prevention and interventions and their merits and demerits. CBPP vaccine was largely unavailable to the pastoralists and the preference of the pastoralists was for vaccination at specified times and vaccine combinations which makes it necessary to avail the vaccine in conformity with the pastoralists preferences. In addition, planning vaccinations should involve pastoralists and neighbouring countries. As the results cannot be generalized, further studies on CBPP control methods and their effectiveness are recommended. PMID:24768437

  5. Pharmacological modulation of spreading depolarizations.

    PubMed

    Sánchez-Porras, Renán; Zheng, Zelong; Sakowitz, Oliver W

    2015-01-01

    Spreading depolarization (SD) is a wave of almost complete depolarization of the neuronal and glial cells. Nowadays there is sufficient evidence demonstrating its pathophysiological effect in migraine with aura, transient global amnesia, stroke, subarachnoid hemorrhage, intracerebral hemorrhage, and traumatic brain injury. In these cases, occurrence of SD has been associated with functional neuronal damage, neuronal necrosis, neurological degeneration, and poor clinical outcome. Animal models show that SD can be modulated by drugs that interfere with its initiation and propagation. There are many pharmacological targets that may help to suppress SD occurrence, such as Na?, K?, Cl?, and Ca˛? channels; Na?/K? -ATPase; gap junctions; and ligand-based receptors, for example, adrenergic, serotonin, sigma-1, calcitonin gene-related peptide, GABAA, and glutamate receptors. In this regard, N-methyl-d-aspartate (NMDA) receptor blockers, in particular, ketamine, have shown promising results. Therefore, theoretically pharmacologic modulation of SD could help diminish its pathological effects. PMID:25366616

  6. SAW correlator spread spectrum receiver

    DOEpatents

    Brocato, Robert W

    2014-04-01

    A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n.times.m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.

  7. Spreading of Saturn's Neutral Torus

    NASA Astrophysics Data System (ADS)

    Cassidy, T. A.; Johnson, R. E.; Kuo, C.

    2009-12-01

    The H2O vapor ejected from Enceladus' south pole forms a Saturn-encircling cloud of neutrals and plasma. Two decades of OH cloud modeling and observations suggested that H2O, and its dissociation and ionization products are spread throughout the Saturnian system primarily by magnetospheric plasma/neutral interactions (e.g., Johnson et al., APJ, 2006). In recent years, Cassini UVIS data has shown even broader O and H clouds that are not reproduced by previous models. Using a Direct Simulation Monte Carlo model of the neutral cloud we have found that the neutral-neutral collisions are key to explaining the unexpected breadth of the O cloud (See also: Farmer, Icarus, 2009). We will also discuss the cloud's curious H2O maser emission (Pogrebenko et al., 2009), which, we hypothesize, is a consequence of electron impact excitation.

  8. Passive immunization of guinea pigs with llama single-domain antibody fragments against foot-and-mouth disease

    Microsoft Academic Search

    M. M. Harmsen; C. B. van Solt; H. P. D. Fijten; L. van Keulen; R. A. Rosalia; K. Weerdmeester; A. H. M. Cornelissen; M. G. M. De Bruin; P. L. Eblé; A. Dekker

    2007-01-01

    Foot-and-mouth disease (FMD) is a highly contagious disease that occasionally causes outbreaks in Europe. There is a need for therapies that provide rapid protection against FMD in outbreak situations. We aim to provide such rapid protection by passive immunization with llama single-domain antibody fragments (VHHs). Twenty-four VHHs binding serotype O FMDV in vitro were isolated from immunized llamas by phage

  9. Diagnosis of foot-and mouth disease by real time reverse transcription polymerase chain reaction under field conditions in Brazil

    Microsoft Academic Search

    Tatiane A Paixăo; Alcina V Carvalho Neta; Naimes O Paiva; Jorge R Reis; Meirivan S Barbosa; Claudia V Serra; René R Silva; Tammy R Beckham; Barbara M Martin; Neville P Clarke; L Garry Adams; Renato L Santos

    2008-01-01

    BACKGROUND: Foot-and-mouth disease (FMD) is an economically important and highly contagious viral disease that affects cloven-hoofed domestic and wild animals. Virus isolation and enzyme-linked immunosorbent assay (ELISA) are the gold standard tests for diagnosis of FMD. As these methods are time consuming, assays based on viral nucleic acid amplification have been developed. RESULTS: A previously described real-time reverse transcriptase polymerase

  10. Sero-prevalence and associated risk factors of peste des petits ruminants and contagious caprine pleuro-pneumonia in goats and sheep in the Southern Zone of Tanzania.

    PubMed

    Mbyuzi, Albano O; Komba, Erick V G; Kimera, Sharadhuli I; Kambarage, Dominic M

    2014-09-01

    A retrospective Sero-prevalence analysis was conducted in 2012 in order to find out whether contagious caprine pleuro-pneumonia (CCPP) and peste des petits ruminants (PPR) had already been introduced in Mtwara and Lindi regions of Southern Tanzania by 2007 and 2009. A total of 477 randomly selected sera from a bank of 3500 small ruminant samples that were collected as part of Rift Valley Fever surveillance of 2007 in Mtwara and Lindi regions were used in this study. Seroconversion was also evaluated in the 504 sera that were collected in 2009 as part of disease outbreak investigations in Tandahimba and Newala districts of Mtwara region. Seroconversions to CCPP and PPR were tested using competitive ELISA. In addition, information on different variables available in the existing surveillance forms gathered during sampling was used in the analysis of risk factors associated with seropositivity to the two diseases. The overall seroprevalence of CCPP for the sera of 2007 and 2009 in goats was 52.1% (n=447) and 35.5% (n=434) respectively; while in sheep the seroprevalence was 36.7% (n=30) and 22.9% (n=70) respectively. Seroconversion to PPR in goats and sheep was 28.7% (n=434) and 35.7% (n=70) respectively based on the sera of 2009. However, no antibodies were detected in the 2007 sera. Mixed infections were detected in 7.4% (n=434) of the goat and 12.9% (n=70) of sheep samples. Significant risk factors associated with seropositivity to CCPP in 2007 included introduction of new animals in flocks (OR=3.94; 95% CI 1.86-8.36; p<0.001) and raising animals in government farms (OR=4.92; 95% CI 1.57-15.76; p=0.02); whereas, seropositivity to CCPP in 2009 increased with introduction of new animals in flocks (OR=18.82; 95% CI 8.06-43.96; p<0.001), raising animals in government farms (OR=4.04; 95% CI 2.69-6.42; p<0.001) and raising animals in Newala district (OR=2.35; 95% CI 1.53-3.62; p<0.001). On the other hand, predictors for seropositivity to PPR in 2009 were introduction of new animals in flocks (OR=2.83; 95% CI 1.73-4.62; p<0.001) and communal grazing of animals (OR=7.60; 95% CI 1.77-32.58; p=0.01). Therefore, these results show that CCPP was already circulating in goats in the southern zone by 2007 and that PPR was probably introduced thereafter. Their presence in this emerging animal keeping area in Tanzania calls for improved surveillance and control systems. PMID:25022914

  11. Viral spreading of daily information in online social networks

    NASA Astrophysics Data System (ADS)

    Kawamoto, Tatsuro; Hatano, Naomichi

    2014-07-01

    We explain a possible mechanism of an information spreading on a network which spreads extremely far from a seed node, namely the viral spreading. On the basis of a model of the information spreading in an online social network, in which the dynamics is expressed as a random multiplicative process of the spreading rates, we will show that the correlation between the spreading rates enhances the chance of the viral spreading, shifting the tipping point at which the spreading goes viral.

  12. Modeling the effects of social impact on epidemic spreading in complex networks

    NASA Astrophysics Data System (ADS)

    Ni, Shunjiang; Weng, Wenguo; Zhang, Hui

    2011-11-01

    We investigate by mean-field analysis and extensive simulations the effects of social impact on epidemic spreading in various typical networks with two types of nodes: active nodes and passive nodes, of which the behavior patterns are modeled according to the social impact theory. In this study, nodes are not only the media to spread the virus, but also disseminate their opinions on the virus-whether there is a need for certain self-protection measures to be taken to reduce the risk of being infected. Our results indicate that the interaction between epidemic spreading and opinion dynamics can have significant influences on the spreading of infectious diseases and related applications, such as the implementation of prevention and control measures against the infectious diseases.

  13. The Interplay between Alpha-Synuclein Clearance and Spreading

    PubMed Central

    Lopes da Fonseca, Tomás; Villar-Piqué, Anna; Outeiro, Tiago Fleming

    2015-01-01

    Parkinson’s Disease (PD) is a complex neurodegenerative disorder classically characterized by movement impairment. Pathologically, the most striking features of PD are the loss of dopaminergic neurons and the presence of intraneuronal protein inclusions primarily composed of alpha-synuclein (?-syn) that are known as Lewy bodies and Lewy neurites in surviving neurons. Though the mechanisms underlying the progression of PD pathology are unclear, accumulating evidence suggests a prion-like spreading of ?-syn pathology. The intracellular homeostasis of ?-syn requires the proper degradation of the protein by three mechanisms: chaperone-mediated autophagy, macroautophagy and ubiquitin-proteasome. Impairment of these pathways might drive the system towards an alternative clearance mechanism that could involve its release from the cell. This increased release to the extracellular space could be the basis for ?-syn propagation to different brain areas and, ultimately, for the spreading of pathology and disease progression. Here, we review the interplay between ?-syn degradation pathways and its intercellular spreading. The understanding of this interplay is indispensable for obtaining a better knowledge of the molecular basis of PD and, consequently, for the design of novel avenues for therapeutic intervention. PMID:25874605

  14. Plant viruses alter insect behavior to enhance their spread

    PubMed Central

    Ingwell, Laura L.; Eigenbrode, Sanford D.; Bosque-Pérez, Nilsa A.

    2012-01-01

    Pathogens and parasites can induce changes in host or vector behavior that enhance their transmission. In plant systems, such effects are largely restricted to vectors, because they are mobile and may exhibit preferences dependent upon plant host infection status. Here we report the first evidence that acquisition of a plant virus directly alters host selection behavior by its insect vector. We show that the aphid Rhopalosiphum padi, after acquiring Barley yellow dwarf virus (BYDV) during in vitro feeding, prefers noninfected wheat plants, while noninfective aphids also fed in vitro prefer BYDV-infected plants. This behavioral change should promote pathogen spread since noninfective vector preference for infected plants will promote acquisition, while infective vector preference for noninfected hosts will promote transmission. We propose the “Vector Manipulation Hypothesis” to explain the evolution of strategies in plant pathogens to enhance their spread to new hosts. Our findings have implications for disease and vector management. PMID:22896811

  15. Simulation of spread and control of lesions in brain.

    PubMed

    Thamattoor Raman, Krishna Mohan

    2012-01-01

    A simulation model for the spread and control of lesions in the brain is constructed using a planar network (graph) representation for the central nervous system (CNS). The model is inspired by the lesion structures observed in the case of multiple sclerosis (MS), a chronic disease of the CNS. The initial lesion site is at the center of a unit square and spreads outwards based on the success rate in damaging edges (axons) of the network. The damaged edges send out alarm signals which, at appropriate intensity levels, generate programmed cell death. Depending on the extent and timing of the programmed cell death, the lesion may get controlled or aggravated akin to the control of wild fires by burning of peripheral vegetation. The parameter phase space of the model shows smooth transition from uncontrolled situation to controlled situation. The simulations show that the model is capable of generating a wide variety of lesion growth and arrest scenarios. PMID:22319549

  16. Spread spectrum time domain reflectometry

    NASA Astrophysics Data System (ADS)

    Smith, Paul Samuel

    For many years, wiring has been treated as a system that could be installed and expected to work for the life of the aircraft. As aircraft age far beyond their original expected life span, this attitude is rapidly changing. Wiring problems have recently been identified as the cause of several tragic mishaps and hundreds of thousands of lost mission hours. Intermittent wiring faults have been and continue to be difficult to resolve. Test methods that pinpoint faults on the ground can miss intermittent failures. New test methods involving spread spectrum signals are investigated that could be used in flight to locate intermittent failures, including open circuits, short circuits, and arcs. Spread spectrum time domain reflectometry (SSTDR) and sequence time domain reflectometry (STDR) are analyzed in light of the signals commonly present on aircraft wiring. Pseudo noise codes used for the generation of STDR and SSTDR signals are analyzed for application in a STDR/SSTDR test system in the presence of noise. The effects of Mil-Std 1553 and white noise on the STDR and SSTDR signals are discussed analytically, through simulations, and with the use of test hardware. A test system using STDR and SSTDR is designed, built, and used to collect STDR and SSTDR test data. The data collected with the STDR/SSTDR test hardware is analyzed and compared to the theoretical results. Experimental data for open and short circuits collected using SSTDR and a curve fitting algorithm shows a maximum range estimation error of +/-0.2 ft for 75O coaxial cable up to 100ft, and +/-0.6ft for a sample 32.5ft non-controlled impedance aircraft cable. Mil-Std 1553 is specified to operate reliably with a signal-to-noise ratio of 17.5dB, and the SSTDR test system was able to locate an open circuit on a cable also carrying simulated Mil-Std 1553 data where the SSTDR signal was 50dB below the Mil-Std 1553 signal. STDR and SSTDR are shown to be effective in detecting and locating dry and wet arcs on wires.

  17. Anatomy of ridge discontinuities, transform fault and overlapping spreading centre, at the slow spreading sedimented Andaman Sea Spreading Centre

    NASA Astrophysics Data System (ADS)

    Jourdain, A.; Singh, S. C.; Klinger, Y.

    2013-12-01

    Transform faults are the major discontinuities and define the main segment boundaries along spreading centres but their anatomy is poorly understood because of their complex seafloor morphology, even though they are observed at all types of spreading centres. Here, we present high-resolution seismic reflection images across the sedimented Andaman Sea Transform Fault where the sediments record the faulting and allow studying the evolution of the transform fault both in space and time. Furthermore, sediments allow the imaging of the faults down to the Moho depth that provides insight on the interplay between tectonic and magmatic processes. On the other hand, overlapping spreading centres (OSC) are small-scale discontinuities, possibly transient, and are observed only along fast or intermediate spreading centres. Exceptionally, an overlapping spreading centre is present at the slow spreading Andaman Sea Spreading Centre, which, we suggest, is due to the presence of thick sediments that hamper the efficient hydrothermal circulation allowing magma to stay much longer in the crust at different depths, and up to close to the segment ends, leading to the development of an overlapping spreading. The seismic reflection images across the OSC indicate the presence of large magma bodies in the crust. Seismic images also provide images of active faults allowing to study the link between faulting and magmatism. Interestingly, an earthquake swarm occurred at propagating limb of the OSC in 2006, after the great 2004 Andaman-Sumatra earthquake of Mw=9.3, highlighting the migration of the OSC westward. In this paper, we will show seismic reflection images and interpret these images in the light of bathymetry and earthquake data, and provide the anatomy of the ridge discontinuities along the slow spreading sedimented Andaman Sea Spreading Centre.

  18. Foot-and-mouth disease virus concentrations in products of animal origin.

    PubMed

    Ryan, E; Mackay, D; Donaldson, A

    2008-01-01

    Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals which can have devastating economic consequences. Maintaining an FMD-free status is a priority for non-endemic countries, which restrict importation of animals and animal products from countries in which the disease is present or sporadic, thus presenting a considerable barrier to international trade. This review examines the concentration of FMD virus in animal tissues during the viraemic stage of disease and in animal products derived from infected animals. PMID:18397496

  19. Spread spectrum mobile radio communications

    NASA Astrophysics Data System (ADS)

    Gupta, S. C.

    1982-12-01

    In this report, we analyze the performance of frequency-hopped spread-spectrum systems under mobile radio channel conditions. Because of its good spectrum-efficiency, frequency-hopped systems seen to be natural candidates for mobile telephony in the near future. We analyze mainly the Frequency-Hopped-Multilevel Frequency Shift-Keyed (FH-MFSK) System, the reason being the established superiority of FH-MFSK over the other modulation, namely the Frequency-Hopped Differential Phase Shift Keyed system (FH-DPSK), under identical conditions. Our new results include the spectrum efficiency analysis of FH-MFSK for various bandwidths of interest, the performance analysis of FH-MFSK under the influence of log-normal shadowing and Rayleigh fading, the possible performance improvement with the inclusion of a small number of space-diversity branches to combat the losses due to fading, a preliminary analysis of the occurrence of burst errors in FH systems, the amount of degradation due to the users operating in the adjacent cells and a possible power control scheme to mitigate these effects and finally a result which establishes the near-equivalent performance of the hard-limited and the likelihood receivers under Rayleigh fading and multi-user interference conditions.

  20. Foot-and-Mouth Disease

    PubMed Central

    Grubman, Marvin J.; Baxt, Barry

    2004-01-01

    Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. The disease was initially described in the 16th century and was the first animal pathogen identified as a virus. Recent FMD outbreaks in developed countries and their significant economic impact have increased the concern of governments worldwide. This review describes the reemergence of FMD in developed countries that had been disease free for many years and the effect that this has had on disease control strategies. The etiologic agent, FMD virus (FMDV), a member of the Picornaviridae family, is examined in detail at the genetic, structural, and biochemical levels and in terms of its antigenic diversity. The virus replication cycle, including virus-receptor interactions as well as unique aspects of virus translation and shutoff of host macromolecular synthesis, is discussed. This information has been the basis for the development of improved protocols to rapidly identify disease outbreaks, to differentiate vaccinated from infected animals, and to begin to identify and test novel vaccine candidates. Furthermore, this knowledge, coupled with the ability to manipulate FMDV genomes at the molecular level, has provided the framework for examination of disease pathogenesis and the development of a more complete understanding of the virus and host factors involved. PMID:15084510