These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

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

ERIC Educational Resources Information Center

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…

Grosse, Susan J.

2

Contagious ovine digital dermatitis: an emerging disease.  

PubMed

The novel sheep disease, contagious ovine digital dermatitis (CODD) was first described in the UK in 1997. The disease is characterised by severe lameness associated with initial inflammation at the coronary band, followed by progressive separation of the hoof capsule from the underlying tissue. On microbiological examination, treponeme bacteria have been frequently isolated from cases of CODD, including treponemes phylogenetically identical to those associated with bovine digital dermatitis (BDD). Dichelobacter nodosus and Fusobacterium necrophorum have also been isolated from CODD lesions although their role in the pathogenesis remains uncertain. While epidemiological data indicate that the prevalence of CODD is increasing in the UK, the routes of transmission and associated risk factors have not been clearly elucidated. Evidenced-based treatment trials indicate that parenteral administration of long-acting amoxicillin is an efficacious treatment for CODD, while anecdotal evidence suggests other antibiotics, given locally and/or parenterally, may also be beneficial. Further microbiological and epidemiological research is urgently required to develop sustainable control strategies, including the development of vaccines and appropriate biosecurity and farm management protocols. In this review current knowledge of the clinical, aetiological, and epidemiological aspects of CODD is assessed as well as approaches to its control. PMID:24973004

Duncan, J S; Angell, J W; Carter, S D; Evans, N J; Sullivan, L E; Grove-White, D H

2014-09-01

3

Flu is a serious contagious disease. Each year in the United States, on average, more  

E-print Network

Flu is a serious contagious disease. Each year in the United States, on average, more than 200,000 people are hospitalized and 36,000 people die from seasonal flu complications. This flu season could be worse. There is a new and very different flu virus spreading worldwide among people called novel or new

Ferrara, Katherine W.

4

Should Persons with Contagious Diseases Be Barred from School?  

ERIC Educational Resources Information Center

Reviews recent court decisions regarding whether individuals with contagious diseases may be barred from public schools. Devotes specific attention to the issue of whether certain communicable diseases such as tuberculosis and Acquired Immune Deficiency Syndrome (AIDS) can be classified as handicaps and thereby qualify a person for protection…

Roe, Richard L.

1987-01-01

5

What To Do When Contagious Disease Strikes Your School.  

ERIC Educational Resources Information Center

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…

American Bar Association, Chicago, IL.

6

Risk and economic consequences of contagious animal disease introduction  

Microsoft Academic Search

Introduction<\\/strong>Within the European Union, epidemics of contagious animal diseases such as Classical Swine Fever (CSF) and Foot-and-Mouth Disease (FMD) are to be eradicated according to strict EU- prescriptions including stamping-out of infected herds, establishment of control and surveillance zones with complete standstill of animals and possible export bans on live animals. Epidemics clearly have a serious impact, in particular on

H. S. Horst

1998-01-01

7

Contagious caprine pleuropneumonia: new aspects of an old disease.  

PubMed

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

Nicholas, R; Churchward, C

2012-06-01

8

Radiographic imaging for patients with contagious infectious diseases: how to acquire chest radiographs of patients infected with the ebola virus.  

PubMed

OBJECTIVE. Contagious infectious diseases add a new dimension to radiology and pose many unanswered questions. In particular, what is the safest way to image patients with contagious and potentially lethal infectious diseases? Here, we describe protocols used by Emory University to successfully acquire chest radiographs of patients with Ebola virus disease. CONCLUSION. Radiology departments need to develop new protocols for various modalities used in imaging patients with contagious and potentially lethal infectious diseases. PMID:25402496

Auffermann, William F; Kraft, Colleen S; Vanairsdale, Sharon; Lyon, G Marshall; Tridandapani, Srini

2015-01-01

9

Supreme Court Holds That Contagious Diseases Are Handicaps.  

ERIC Educational Resources Information Center

Describes a complex case involving termination of a third-grade teacher with recurrent tuberculosis. The United States Supreme Court upheld a circuit court's ruling that the teacher's condition satisfied section 504 of the 1973 Rehabilitation Act protecting handicapped persons against discrimination. Since contagiousness was not addressed, the…

Flygare, Thomas J.

1987-01-01

10

Contagious Diseases in Competitive Sport: What Are the Risks?  

ERIC Educational Resources Information Center

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.…

Dorman, John M.

2000-01-01

11

Contagious rhythm: infectious diseases of 20th century musicians.  

PubMed

Infectious diseases have led to illness and death for many famous musicians, from the classical period to the rock 'n' roll era. By the 20th century, as public health improved and orchestral composers began living more settled lives, infections among American and European musicians became less prominent. By mid-century, however, seminal jazz musicians famously pursued lifestyles characterized by drug and alcohol abuse. Among the consequences of this risky lifestyle were tuberculosis, syphilis, and chronic viral hepatitis. More contemporary rock musicians have experienced an epidemic of hepatitis C infection and HIV/AIDS related to intravenous drug use and promiscuity. Musical innovation is thus often accompanied by diseases of neglect and overindulgence, particularly infectious illnesses, although risky behavior and associated infectious illnesses tend to decrease as the style matures. PMID:20660936

Sartin, Jeffrey S

2010-07-01

12

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

SciTech Connect

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.

Hirsch, Gary B.

2007-03-01

13

Global Spread of Infectious Diseases  

E-print Network

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.

S. Hsu; A. Zee

2003-06-25

14

Graphing the Spread of Disease  

NSDL National Science Digital Library

Students simulate disease transmission by collecting data based on their proximity to other students. One option for measuring proximity is by having Bluetooth devices "discover" each other. After data is collected, students apply graph theory to analyze it, and summarize their data and findings in lab report format. Students learn real-world engineering applications of graph theory and see how numerous instances of real-world relationships can be more thoroughly understood by applying graph theory. Also, by applying graph theory the students are able to come up with possible solutions to limit the spread of disease. The activity is intended to be part of a computer science curriculum and knowledge of the Java programming language is required. To complete the activity, a computer with Java installed and appropriate editing software is needed.

IMPART RET Program, College of Information Science & Technology,

15

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

PubMed Central

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

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

2013-01-01

16

CONTAGIOUS DISEASE MODULE FOR THE JOINT EFFECTS MODEL Mr. Jason Rodriguez, Ms. Karen E. Cheng, Dr. Gene E. McClellan, Dr. David J. Crary, and Dr.  

E-print Network

smallpox and plague. Smallpox and plague are contagious diseases that lead to an additional load on medical at risk. In order to properly defend against an attack involving smallpox or plague, medical planners must

Ray, Jaideep

17

Nosocomial Spread of Viral Disease  

PubMed Central

Viruses are important causes of nosocomial infection, but the fact that hospital outbreaks often result from introduction(s) from community-based epidemics, together with the need to initiate specific laboratory testing, means that there are usually insufficient data to allow the monitoring of trends in incidences. The most important defenses against nosocomial transmission of viruses are detailed and continuing education of staff and strict adherence to infection control policies. Protocols must be available to assist in the management of patients with suspected or confirmed viral infection in the health care setting. In this review, we present details on general measures to prevent the spread of viral infection in hospitals and other health care environments. These include principles of accommodation of infected patients and approaches to good hygiene and patient management. They provide detail on individual viral diseases accompanied in each case with specific information on control of the infection and, where appropriate, details of preventive and therapeutic measures. The important areas of nosocomial infection due to blood-borne viruses have been extensively reviewed previously and are summarized here briefly, with citation of selected review articles. Human prion diseases, which present management problems very different from those of viral infection, are not included. PMID:11432812

Aitken, Celia; Jeffries, Donald J.

2001-01-01

18

Nosocomial spread of viral disease.  

PubMed

Viruses are important causes of nosocomial infection, but the fact that hospital outbreaks often result from introduction(s) from community-based epidemics, together with the need to initiate specific laboratory testing, means that there are usually insufficient data to allow the monitoring of trends in incidences. The most important defenses against nosocomial transmission of viruses are detailed and continuing education of staff and strict adherence to infection control policies. Protocols must be available to assist in the management of patients with suspected or confirmed viral infection in the health care setting. In this review, we present details on general measures to prevent the spread of viral infection in hospitals and other health care environments. These include principles of accommodation of infected patients and approaches to good hygiene and patient management. They provide detail on individual viral diseases accompanied in each case with specific information on control of the infection and, where appropriate, details of preventive and therapeutic measures. The important areas of nosocomial infection due to blood-borne viruses have been extensively reviewed previously and are summarized here briefly, with citation of selected review articles. Human prion diseases, which present management problems very different from those of viral infection, are not included. PMID:11432812

Aitken, C; Jeffries, D J

2001-07-01

19

Modeling the spread of infectious disease  

Microsoft Academic Search

The study of disease spread among large populations is a daunting task to perform without the aid of computers. Not only does this require extensive data retrieval and analysis, but it is impossible to test multiple scenarios. Pestilence is a program that allows students to explore the patterns of disease spread. Pestilence was developed using Netlogo, a programmable modeling environment.

Joseph Glessner

2005-01-01

20

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

PubMed

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

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

2015-02-01

21

SIR Model for Spread of Disease  

NSDL National Science Digital Library

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.

Smith, David

2001-01-22

22

Social distancing strategies against disease spreading  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

23

Social Distancing Strategies against Disease Spreading  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

24

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

E-print Network

are alert on the highly contagious disease and make necessary self-protection with masks. The prompt action is shown on evaluating the screening control over train stations in Singapore. The optimization algorithm

Wong, Limsoon

25

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

NASA Astrophysics Data System (ADS)

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.

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

26

Modeling daily flow patterns individuals to characterize disease spread  

SciTech Connect

The effect of an individual's travels throughout a day on the spread of disease is examined using a deterministic SIR model. We determine which spatial and demographic characteristics most contribute to the disease spread and whether the progression of the disease can be slowed by appropriate vaccination of people belonging to a specific location-type.

Smallwood, J. (Jeanine); Hyman, J. M. (James M.); Mirchandani, Pitu B.

2002-11-17

27

Childhood Contagious Diseases  

MedlinePLUS

... this site constitutes acceptance of Skinsight's terms of service and privacy policy. The material on this site is for informational purposes only, and is not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider.

28

Spreading Processes Modeling Infectious Disease Dynamics with Networks  

E-print Network

Spreading Processes Modeling Infectious Disease Dynamics with Networks #12;What is epidemiology-location Network Ref: Meyers et al (2003) Emerging Infectious Diseases 9, 204-210 #12;Office Hours Shweta Bansal control the spread? #12;S I R susceptible infectious recovered Compartmental models I dt dR IIIS dt d

Albert, RĂ©ka

29

Spreading of sexually transmitted diseases in heterosexual populations  

E-print Network

Disease spreading is a topical issue in a variety of fields ranging from computer viruses in the Internet to air-borne (e.g. influenza) diseases in societies. In particular, the description of the spread of sexually transmitted diseases (Chlamydia, Syphilis, Gonorrhea, AIDS) across population constitutes a major concern for scientists and health agencies. In this context, both data collection on sexual contact networks and the modeling of disease spreading are intensively contributing to the search for effective immunization policies. Here, the spread of sexually transmitted diseases on bipartite scale-free graphs, representing heterosexual contact networks, is considered. We analytically derive the expression for the epidemic threshold and its dependence with the system size in finite populations. The results indicate that in finite bipartite populations with degree distribution as those found in national surveys of sexual attitudes, the onset of the epidemic outbreak takes place for larger spreading rates t...

Gómez-Gardenes, J; Moreno, Y; Profumo, E V

2007-01-01

30

Contagious yawning in chimpanzees.  

PubMed Central

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

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

2004-01-01

31

Contagious yawning in chimpanzees.  

PubMed

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

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

2004-12-01

32

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

E-print Network

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

Ferrara, Katherine W.

33

A Cellular Automaton Framework for Infectious Disease Spread Simulation  

PubMed Central

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

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

34

Research in motion: the enigma of Parkinson's disease pathology spread  

Microsoft Academic Search

Neuropathological changes in Parkinson's disease progress slowly and spread according to a characteristic pattern. Recent papers have shed light on this progression of pathology by examining the fate of neurons grafted into the brains of patients with Parkinson's disease. Two of these studies demonstrate that grafted healthy neurons can gradually develop the same pathology as host neurons in the diseased

Patrik Brundin; Jia-Yi Li; Janice L. Holton; Olle Lindvall; Tamas Revesz

2008-01-01

35

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

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…

Virginia State Dept. of Criminal Justice Services, Richmond.

36

Marek’s disease virus pathogenesis and latency   

E-print Network

Marek’s Disease virus (MDV) is a highly contagious, widespread and persistent neoplastic ?-herpesvirus causing extensive lymphoblastic tumours in chickens. The virus is shed in feather dust and spread through inhalation. ...

Hunter, Gillian

2012-11-30

37

Contagious yawning and the brain  

Microsoft Academic Search

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

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

2005-01-01

38

Global Transport Networks and Infectious Disease Spread  

PubMed Central

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

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

2011-01-01

39

Modelling the spread of foot-and-mouth disease virus  

E-print Network

Modelling the spread of foot-and-mouth disease virus F Moutou B Durand CNEVA, Laboratoire Central de Recherches VĂ©tĂ©rinaires, BP 67, F94703 Maisons-Alfort, France Summary ― Foot-and-mouth, to give arguments for the best sanitary decision within the emergency plan. foot-and-mouth disease

Paris-Sud XI, Université de

40

Techniques for Preventing the Spread of Infectious Diseases.  

ERIC Educational Resources Information Center

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…

California State Dept. of Education, Sacramento.

41

A survey of visitors on Swedish livestock farms with reference to the spread of animal diseases  

PubMed Central

Background In addition to livestock movements, other between-farm contacts such as visitors may contribute to the spread of contagious animal diseases. Knowledge about such contacts is essential for contingency planning. Preventive measures, risk-based surveillance and contact tracing may be facilitated if the frequency and type of between-farm contacts can be assessed for different types of farms. The aim of this study was to investigate the frequency and types of visitors on farms with cloven-hoofed animals in Sweden and to analyse whether there were differences in the number of visitors attributable to region, season, and type of herd. Data were collected from Swedish farmers through contact-logs covering two-week periods during four different seasons. Results In total, 482 (32%) farmers filled in the contact log for at least one period and the data represent 18,416 days. The average number of professional and non-professional visitors per day was 0.3 and 0.8, respectively. Whereas the number of professional visitors seemed to increase with increasing herd size, this relation was not seen for non-professional visits. The mean numbers of visitors per day were highest in the summer and in the farm category ‘small mixed farm’. Reports of the visitors’ degree of contact with the animals showed that veterinarians, AI-technicians, animal transporters and neighbours were often in direct contact with the animals or entered the stables and 8.8% of the repairmen were also in direct contact with animals, which was unexpected. In a multivariable analysis, species, herd size and season were significantly associated with the number of professional visitors as well as the number of visitors in direct contact with the animals. Conclusion In conclusion there was a large variation between farms in the number and type of contacts. The number of visitors that may be more likely to spread diseases between farms was associated with animal species and herd size. PMID:24040830

2013-01-01

42

Modelling power-law spread of infectious diseases  

E-print Network

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 ...

Meyer, Sebastian

2013-01-01

43

Spreading of sexually transmitted diseases in heterosexual populations  

PubMed Central

The spread of sexually transmitted diseases (e.g., chlamydia, syphilis, gonorrhea, HIV, etc.) across populations is a major concern for scientists and health agencies. In this context, both the data collection on sexual contact networks and the modeling of disease spreading are intensive contributions to the search for effective immunization policies. Here, the spreading of sexually transmitted diseases on bipartite scale-free graphs, representing heterosexual contact networks, is considered. We analytically derive the expression for the epidemic threshold and its dependence with the system size in finite populations. We show that the epidemic outbreak in bipartite populations, with number of sexual partners distributed as in empirical observations from national sex surveys, takes place for larger spreading rates than for the case in which the bipartite nature of the network is not taken into account. Numerical simulations confirm the validity of the theoretical results. Our findings indicate that the restriction to crossed infections between the two classes of individuals (males and females) has to be taken into account in the design of efficient immunization strategies for sexually transmitted diseases. PMID:18212127

Gómez-Gardeńes, Jesús; Latora, Vito; Moreno, Yamir; Profumo, Elio

2008-01-01

44

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

E-print Network

Evaluating the links between climate, disease spread, and amphibian declines Jason R. Rohra,1 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

Rohr, Jason

45

Landscape modelling spatial bottlenecks: implications for raccoon rabies disease spread  

PubMed Central

A landscape genetic simulation modelling approach is used to understand factors affecting raccoon rabies disease spread in southern Ontario, Canada. Using the Ontario Rabies Model, we test the hypothesis that landscape configuration (shape of available habitat) affects dispersal, as indicated by genetic structuring. We simulated range expansions of raccoons from New York into vacant landscapes in Ontario, in two areas that differed by the presence or absence of a landscape constriction. Our results provide theoretical evidence that landscape constriction acts as a vicariant bottleneck. We discuss implications for raccoon rabies spread. PMID:19324623

Rees, Erin E.; Pond, Bruce A.; Cullingham, Catherine I.; Tinline, Rowland R.; Ball, David; Kyle, Christopher J.; White, Bradley N.

2009-01-01

46

Landscape modelling spatial bottlenecks: implications for raccoon rabies disease spread.  

PubMed

A landscape genetic simulation modelling approach is used to understand factors affecting raccoon rabies disease spread in southern Ontario, Canada. Using the Ontario Rabies Model, we test the hypothesis that landscape configuration (shape of available habitat) affects dispersal, as indicated by genetic structuring. We simulated range expansions of raccoons from New York into vacant landscapes in Ontario, in two areas that differed by the presence or absence of a landscape constriction. Our results provide theoretical evidence that landscape constriction acts as a vicariant bottleneck. We discuss implications for raccoon rabies spread. PMID:19324623

Rees, Erin E; Pond, Bruce A; Cullingham, Catherine I; Tinline, Rowland R; Ball, David; Kyle, Christopher J; White, Bradley N

2009-06-23

47

Protein aggregate spreading in neurodegenerative diseases: Problems and perspectives  

PubMed Central

Progressive accumulation of specific protein aggregates is a defining feature of many major neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, fronto-temporal dementia, Huntington’s disease, and Creutzfeldt–Jakob disease (CJD). Findings from several recent studies have suggested that aggregation-prone proteins, such as tau, ?-synuclein, polyglutamine-containing proteins, and amyloid-?, can spread to other cells and brain regions, a phenomenon considered unique to prion disorders, such as CJD and bovine spongiform encephalopathy. Cell-to-cell propagation of protein aggregates may be the general underlying principle for progressive deterioration of neurodegenerative diseases. This may also have significant implications in cell replacement therapies, as evidenced by the propagation of ?-synuclein aggregates from host to grafted cells in long-term transplants in Parkinson’s patients. Here, we review recent progress in protein aggregate propagation in experimental model systems and discuss outstanding questions and future perspectives. Understanding the mechanisms of this pathological spreading may open the way to unique opportunities for development of diagnostic techniques and novel therapies for protein misfolding-associated neurodegenerative diseases. PMID:21624403

Lee, Seung-Jae; Lim, Hee-Sun; Masliah, Eliezer; Lee, He-Jin

2014-01-01

48

The landscape genetics of infectious disease emergence and spread  

PubMed Central

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

Biek, Roman; Real, Leslie A.

2011-01-01

49

Computational Study of Ventilation and Disease Spread in Poultry Houses  

NASA Astrophysics Data System (ADS)

The air flow in and around poultry houses has been studied numerically with the goal of determining disease spread characteristics and comparing ventilation schemes. A typical manure-belt layer egg production facility is considered. The continuity, momentum, and energy equations are solved for flow both inside and outside poultry houses using the commercial computational fluid dynamics (CFD) code FLUENT. Both simplified two-dimensional and fully three-dimensional geometries are modeled. The spread of virus particles is considered to be analogous to diffusion of a tracer contaminant gas, in this case ammonia. The effect of thermal plumes produced by the hens in the poultry house is also considered. Two ventilation schemes with opposite flow directions are compared. Contours of temperature and ammonia mass fraction for both cases are obtained and compared. The analysis shows that ventilation and air quality characteristics are much better for the case in which the air flow is from bottom to top (enhancing the thermal plume) instead of from top to bottom (fighting the thermal plume) as in most poultry houses. This has implications in air quality control in the event of epidemic outbreaks of avian flu or other infectious diseases.

Cimbala, John; Pawar, Sourabh; Wheeler, Eileen; Lindberg, Darla

2006-11-01

50

Contagious yawning and the brain.  

PubMed

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

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

2005-05-01

51

Spreading of periodic diseases and synchronization phenomena on networks  

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

52

Does genetic diversity limit disease spread in natural host populations?  

PubMed Central

It is a commonly held view that genetically homogenous host populations are more vulnerable to infection than genetically diverse populations. The underlying idea, known as the ‘monoculture effect,' is well documented in agricultural studies. Low genetic diversity in the wild can result from bottlenecks (that is, founder effects), biparental inbreeding or self-fertilization, any of which might increase the risk of epidemics. Host genetic diversity could buffer populations against epidemics in nature, but it is not clear how much diversity is required to prevent disease spread. Recent theoretical and empirical studies, particularly in Daphnia populations, have helped to establish that genetic diversity can reduce parasite transmission. Here, we review the present theoretical work and empirical evidence, and we suggest a new focus on finding ‘diversity thresholds.' PMID:22713998

King, K C; Lively, C M

2012-01-01

53

Using mobile phone call data records for modelling infectious disease spread  

E-print Network

Using mobile phone call data records for modelling infectious disease contacts and using the CDR directly for modelling infectious disease spread between individuals would. This understanding will be leveraged to develop the most appropriate models of infectious disease spread based on CDR

Wright, Francis

54

Key node selection for containing infectious disease spread using particle swarm optimization  

Microsoft Academic Search

In recent years, some emerging and reemerging 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, screening infected people is an efficient way for evaluating the infection scale and controlling the spread of infectious diseases. Considering the

Xiuju Fu; Sonja Lim; Lipo Wang; G. Lee; S. Ma; Limsoon Wong; Gaoxi Xiao

2009-01-01

55

Alpha-synuclein spreading in Parkinson’s disease  

PubMed Central

Formation and accumulation of misfolded protein aggregates are a central hallmark of several neurodegenerative diseases. In Parkinson’s disease (PD), the aggregation-prone protein alpha-synuclein (?-syn) is the culprit. In the past few years, another piece of the puzzle has been added with data suggesting that ?-syn may self-propagate, thereby contributing to the progression and extension of PD. Of particular importance, it was the seminal observation of Lewy bodies (LB), a histopathological signature of PD, in grafted fetal dopaminergic neurons in the striatum of PD patients. Consequently, these findings were a conceptual breakthrough, generating the “host to graft transmission” hypothesis, also called the “prion-like hypothesis.” Several in vitro and in vivo studies suggest that ?-syn can undergo a toxic templated conformational change, spread from cell to cell and from region to region, and initiate the formation of “LB–like aggregates,” contributing to the PD pathogenesis. Here, we will review and discuss the current knowledge for such a putative mechanism on the prion-like nature of ?-syn, and discuss about the proper use of the term prion-like. PMID:25565982

Recasens, Ariadna; Dehay, Benjamin

2014-01-01

56

Edge-Based Compartmental Modeling for Infectious Disease Spread Part III: Disease and Population Structure  

E-print Network

We consider the edge-based compartmental models for infectious disease spread introduced in Part I. These models allow us to consider standard SIR diseases spreading in random populations. In this paper we show how to handle deviations of the disease or population from the simplistic assumptions of Part I. We allow the population to have structure due to effects such as demographic detail or multiple types of risk behavior the disease to have more complicated natural history. We introduce these modifications in the static network context, though it is straightforward to incorporate them into dynamic networks. We also consider serosorting, which requires using the dynamic network models. The basic methods we use to derive these generalizations are widely applicable, and so it is straightforward to introduce many other generalizations not considered here.

Miller, Joel C

2011-01-01

57

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

E-print Network

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

Standiford, Richard B.

58

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

E-print Network

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

Meester, Ronald

59

Miniaturized paper-based gene sensor for rapid and sensitive identification of contagious plant virus.  

PubMed

Plant viruses cause significant production and economic losses in the agricultural industry worldwide. Rapid and early identification of contagious plant viruses is an essential prerequisite for the effective control of further spreading of infection. In this work, we describe a miniaturized paper-based gene sensor for the rapid and sensitive identification of a contagious plant virus. Our approach makes use of hybridization-mediated target capture based on a miniaturized lateral flow platform and gold nanoparticle colorimetric probes. The captured colorimetric probes on the test line and control line of the gene sensor produce characteristic red bands, enabling visual detection of the amplified products within minutes without the need for sophisticated instruments or the multiple incubation and washing steps performed in most other assays. Quantitative analysis is realized by recording the optical intensity of the test line. The sensor was used successfully for the identification of banana bunchy top virus (BBTV). The detection limit was 0.13 aM of gene segment, which is 10 times higher than that of electrophoresis and provides confirmation of the amplified products. We believe that this simple, rapid, and sensitive bioactive platform has great promise for warning against plant diseases in agricultural production. PMID:25412341

Wei, Jitao; Liu, Hongxing; Liu, Fang; Zhu, Minjun; Zhou, Xiaoming; Xing, Da

2014-12-24

60

An alternate delivery system improves vaccine performance against foot-and-mouth disease virus (FMDV)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) causes vesicular disease of cloven-hoofed animals with severe agricultural and economic implications. One of the most highly infectious and contagious livestock pathogens known, the disease spreads rapidly in naďve populations making it critical to have rapidly ac...

61

Developmental and comparative perspectives of contagious yawning.  

PubMed

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

Senju, Atsushi

2010-01-01

62

Some Similarities between the Spread of an Infectious Disease and Population Growth  

NSDL National Science Digital Library

A simple simulation demonstrates how spread of an infectious disease can result in exponential increase in the number of infected individuals. Discussion questions and a graphing activity develop an understanding of exponential and logistic population growth.

Doherty, Jennifer; Waldron, Ingrid

63

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

E-print Network

Modelling the initial spread of foot-and-mouth disease through animal movements D. M. Green*, I. Z, as in the 2001 epidemic of foot-and-mouth disease (FMD) in the UK. Here, the movement data are used to construct of England than elsewhere. Keywords: modelling; epidemiology; foot-and-mouth disease 1. INTRODUCTION Control

Kiss, Istvan Zoltan

64

The role of spatial mixing in the spread of foot-and-mouth disease  

E-print Network

The role of spatial mixing in the spread of foot-and-mouth disease G. Chowell a,b,Ă? , A.L. Rivas on the 2001 Uruguayan foot-and-mouth disease epidemic), was used for testing. Significant differences between. Keywords: Foot-and-mouth disease; Spatial mathematical model; Reproductive number; Uruguay; Movement

Chowell, Gerardo

65

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

E-print Network

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

Linder, Tamás

66

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

E-print Network

Generalized Markov Models of Infectious Disease Spread: A Novel Framework for Developing Dynamic 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

Cohen, Ted

67

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

E-print Network

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.

Britta Daudert; Bai-Lian Li

2006-11-23

68

Control of the deliberate spread of foot-and-mouth disease virus.  

PubMed

Foot-and-mouth disease (FMD) is one of the most feared of transboundary animal diseases. Accidental or deliberate release of the causative agent can have both direct and indirect effects that result in massive economic losses and disruption. The direct effects of an FMD outbreak include immediate losses to agricultural production and disruption of local economies, while the indirect effects are mainly related to disease control measures such as restriction of market access at local and global levels and the high costs of disease control. To improve the capacity of the European Union (EU) to counter animal bioterrorism threats, AniBioThreat was launched with a special focus on threats to living animals, feed, and food of animal origin. As part of this project, several zoonotic or animal pathogenic agents are considered from different perspectives. FMD virus was selected as one agent to be scrutinized because it is highly contagious and an outbreak can have a severe economic impact. Ways to fight a deliberate outbreak can be demonstrated through the example of FMD. In this article, the virology and epidemiology of FMD virus are discussed with special attention to the related law enforcement aspects. PMID:23971796

Farsang, Attila; Frentzel, Hendrik; Kulcsár, Gábor; Soós, Tibor

2013-09-01

69

Disease spreading on fitness-rewired complex networks  

NASA Astrophysics Data System (ADS)

As people travel, human contact networks may change topologically from time to time. In this paper, we study the problem of epidemic spreading on this kind of dynamic network, specifically the one in which the rewiring dynamics of edges are carried out to preserve the degree of each node (called fitness rewiring). We also consider the adaptive rewiring of edges, which encourages disconnections from and discourages connections to infected nodes and eventually leads to the isolation of the infected from the susceptible with only a small number of links between them. We find that while the threshold of epidemic spreading remains unchanged and prevalence increases in the fitness rewiring dynamics, meeting of the epidemic threshold is delayed and prevalence is reduced (if adaptive dynamics are included). To understand these different behaviors, we introduce a new measure called the “mean change of effective links” and find that creation and deletion of pathways for pathogen transmission are the dominant factors in fitness and adaptive rewiring dynamics, respectively.

Yoo, Jaewan; Lee, J. S.; Kahng, B.

2011-11-01

70

Contagious yawning in autistic and typical development.  

PubMed

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

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

2010-01-01

71

Investigating Disease Spread between Two Assessment Dates with Permutation Tests on a Lattice.  

PubMed

ABSTRACT Mapping and analyzing the disease status of individual plants within a study area at successive dates can give insight into the processes involved in the spread of a disease. We propose a permutation method to analyze such spatiotemporal maps of binary data (healthy or diseased plants) in regularly spaced plantings. It requires little prior information on the causes of disease spread and handles missing plants and censored data. A Monte Carlo test is used to assess whether the location of newly diseased plants is independent of the location of previously diseased plants. The test takes account of the significant spatial structures at each date in order to separate nonrandomness caused by the structure at one date from nonrandomness caused by the dependence between newly diseased plants and previously diseased plants. If there is a nonrandom structure at both dates, independent patterns are simulated by randomly shifting the entire pattern observed at the second date. Otherwise, independent patterns are simulated by randomly reallocating the positions of one group of diseased plants. Simulated and observed patterns of disease are then compared through distance-based statistics. The performance of the method and its robustness are evaluated by its ability to accurately identify simulated independent and dependent bivariate point patterns. Additionally, two realworld spatiotemporal maps with contrasting disease progress illustrate how the tests can provide valuable clues about the processes of disease spread. This method can supplement biological investigations and be used as an exploratory step before developing a specific mechanistic model. PMID:18943557

Thébaud, Gaël; Peyrard, Nathalie; Dallot, Sylvie; Calonnec, Agnčs; Labonne, Gérard

2005-12-01

72

Natural Human Mobility Patterns and Spatial Spread of Infectious Diseases  

NASA Astrophysics Data System (ADS)

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.

Belik, Vitaly; Geisel, Theo; Brockmann, Dirk

2011-08-01

73

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

Microsoft Academic Search

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

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

2011-01-01

74

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

Microsoft Academic Search

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

Alden S. Klovdahl

1985-01-01

75

Analytic models for the patchy spread of plant disease  

Microsoft Academic Search

Plant epidemiologists have long been concerned with the patchy nature of plant disease epidemics. This paper presents a new\\u000a analytical model for patchy plant epidemics (and patchy dynamics in general), using a second-order approximation to capture\\u000a the spatial dynamics in terms of the densities and spatial covariances of healthy and infected hosts. Using these spatial\\u000a moment equations helps us to

Benjamin M. Bolker

1999-01-01

76

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

PubMed Central

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

Yaesoubi, Reza; Cohen, Ted

2011-01-01

77

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

E-print Network

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 ...

Yoneyama, Teruhiko; Krishnamoorthy, Mukkai

2010-01-01

78

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

PubMed

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

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

2014-10-01

79

Developmental and Comparative Perspectives of Contagious Yawning  

Microsoft Academic Search

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

Atsushi Senju

2010-01-01

80

Do dogs ( Canis familiaris ) show contagious yawning?  

Microsoft Academic Search

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

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

2009-01-01

81

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

PubMed

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

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

2014-02-22

82

The role of wild animals in the spread of exotic diseases in Australia.  

PubMed

The distributions of the following feral animals are given -- cattle, buffalo, pig, goat, deer, camel, horse, donkey, fox, dog and cat -- and the native dingo. The possible role these and the native rodents, marsupials and monotremes would play should an exotic disease of livestock enter Australia is discussed. It is considered that feral animals would be important in creating foci from which the disease would spread. PMID:1021109

Murray, M D; Snowdon, W A

1976-12-01

83

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...

84

Do dogs (Canis familiaris) show contagious yawning?  

PubMed

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

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

2009-11-01

85

Chronic contamination decreases disease spread: a Daphnia–fungus–copper case study  

PubMed Central

Chemical contamination and disease outbreaks have increased in many ecosystems. However, connecting pollution to disease spread remains difficult, in part, because contaminants can simultaneously exert direct and multi-generational effects on several host and parasite traits. To address these challenges, we parametrized a model using a zooplankton–fungus–copper system. In individual-level assays, we considered three sublethal contamination scenarios: no contamination, single-generation contamination (hosts and parasites exposed only during the assays) and multi-generational contamination (hosts and parasites exposed for several generations prior to and during the assays). Contamination boosted transmission by increasing contact of hosts with parasites. However, it diminished parasite reproduction by reducing the size and lifespan of infected hosts. Multi-generational contamination further reduced parasite reproduction. The parametrized model predicted that a single generation of contamination would enhance disease spread (via enhanced transmission), whereas multi-generational contamination would inhibit epidemics relative to unpolluted conditions (through greatly depressed parasite reproduction). In a population-level experiment, multi-generational contamination reduced the size of experimental epidemics but did not affect Daphnia populations without disease. This result highlights the importance of multi-generational effects for disease dynamics. Such integration of models with experiments can provide predictive power for disease problems in contaminated environments. PMID:22593104

Civitello, David J.; Forys, Philip; Johnson, Adam P.; Hall, Spencer R.

2012-01-01

86

Cellular Changes Induced by Adenovirus Vaccine Vectors Expressing Foot-and-Mouth Disease Virus Structural and Nonstructural Proteins  

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 virus spread. Adenovirus-based FMD subunit vaccines containing the coding region of viral ca...

87

A Comparison between Two Simulation Models for Spread of Foot-and-Mouth Disease  

PubMed Central

Two widely used simulation models of foot-and-mouth disease (FMD) were used in order to compare the models’ predictions in term of disease spread, consequence, and the ranking of the applied control strategies, and to discuss the effect of the way disease spread is modeled on the predicted outcomes of each model. The DTU-DADS (version 0.100), and ISP (version 2.001.11) were used to simulate a hypothetical spread of FMD in Denmark. Actual herd type, movements, and location data in the period 1st October 2006 and 30th September 2007 was used. The models simulated the spread of FMD using 3 different control scenarios: 1) A basic scenario representing EU and Danish control strategies, 2) pre-emptive depopulation of susceptible herds within a 500 meters radius around the detected herds, and 3) suppressive vaccination of susceptible herds within a 1,000 meters radius around the detected herds. Depopulation and vaccination started 14 days following the detection of the first infected herd. Five thousand index herds were selected randomly, of which there were 1,000 cattle herds located in high density cattle areas and 1,000 in low density cattle areas, 1,000 swine herds located in high density swine areas and 1,000 in low density swine areas, and 1,000 sheep herds. Generally, DTU-DADS predicted larger, longer duration and costlier epidemics than ISP, except when epidemics started in cattle herds located in high density cattle areas. ISP supported suppressive vaccination rather than pre-emptive depopulation, while DTU-DADS was indifferent to the alternative control strategies. Nonetheless, the absolute differences between control strategies were small making the choice of control strategy during an outbreak to be most likely based on practical reasons. PMID:24667525

Halasa, Tariq; Boklund, Anette; Stockmarr, Anders; Enře, Claes; Christiansen, Lasse E.

2014-01-01

88

Contagious Development Neighbor Interactions in Deforestation  

E-print Network

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

Pfaff, Alex

89

Social modulation of contagious yawning in wolves.  

PubMed

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

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

2014-01-01

90

Progression of relapsing-remitting demyelinating disease does not require increased TCR affinity or epitope spread.  

PubMed

In this study, we investigate the basis of T cell recognition of myelin that governs the progression from acute symptoms into disease remission, relapse, and chronic progression in a secondary progressive model of demyelinating disease. Until now, the frequency and affinity of myelin-reactive CD4 T cells that elicit relapsing-remitting disease have not been quantified. The micropipette adhesion frequency assay was used to obtain a sensitive and physiologically relevant two-dimensional measurement of frequency and TCR affinity for myelin, as the inherent low affinity does not allow the use of specific peptide:MHC-II tetramers for this purpose. We found the highest affinity and frequency of polyclonal myelin oligodendrocyte glycoprotein-reactive cells infiltrate the CNS during acute disease, whereas affinities during remission, relapse, and chronic disease are not significantly different from each other. Frequency analysis revealed that the vast majority of CNS-infiltrating CD4 T cells are myelin oligodendrocyte glycoprotein reactive at all time points, demonstrating epitope spread is not a predominant factor for disease progression. Furthermore, time points at which mice were symptomatic were characterized by an infiltration of Th17 cells in the CNS, whereas symptom remission showed an enrichment of cells producing IFN-?. Also, the ratio of regulatory T cells to Foxp3(-) CD4 T cells was significantly higher in the CNS at remission than during acute disease. The results of this study indicate that a high frequency of T cells specific for a single myelin Ag, rather than increased TCR affinity or epitope spread, governs the transition from acute symptoms through remission, relapse, and chronic disease states. PMID:25267971

Kersh, Anna E; Edwards, Lindsay J; Evavold, Brian D

2014-11-01

91

Power law approximations of movement network data for modeling infectious disease spread.  

PubMed

Globalization and increased mobility of individuals enable person-to-person transmitted infectious diseases to spread faster to distant places around the world, making good models for the spread increasingly important. We study the spatiotemporal pattern of spread in the remotely located and sparsely populated region of North Norway in various models with fixed, seasonal, and random effects. The models are applied to influenza A counts using data from positive microbiology laboratory tests as proxy for the underlying disease incidence. Human travel patterns with local air, road, and sea traffic data are incorporated as well as power law approximations thereof, both with quasi-Poisson regression and based on the adjacency structure of the relevant municipalities. We investigate model extensions using information about the proportion of positive laboratory tests, data on immigration from outside North Norway and by connecting population to the movement network. Furthermore, we perform two separate analyses for nonadults and adults as children are an important driver for influenza A. Comparisons of one-step-ahead predictions generally yield better or comparable results using power law approximations. PMID:24843881

Geilhufe, Marc; Held, Leonhard; Skrřvseth, Stein Olav; Simonsen, Gunnar S; Godtliebsen, Fred

2014-05-01

92

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

PubMed

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

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

2013-06-01

93

Demodex gatoi -associated contagious pruritic dermatosis in cats - a report from six households in Finland  

Microsoft Academic Search

BACKGROUND: Demodex gatoi is unique among demodectic mites. It possesses a distinct stubby appearance, and, instead of residing in the hair follicles, it dwells in the keratin layer of the epidermis, causing a pruritic and contagious skin disease in cats. Little is known of the occurrence of D. gatoi in Europe or control of D. gatoi infestation. CASE PRESENTATION: We

Seppo AM Saari; Kirsi H Juuti; Joanna H Palojärvi; Kirsi M Väisänen; Riitta-Liisa Rajaniemi; Leena E Saijonmaa-Koulumies

2009-01-01

94

Spread of infectious diseases in a hyperbolic reaction-diffusion susceptible-infected-removed model  

NASA Astrophysics Data System (ADS)

A one-dimensional hyperbolic reaction-diffusion model of epidemics is developed to describe the dynamics of diseases spread occurring in an environment where three kinds of individuals mutually interact: the susceptibles, the infectives, and the removed. It is assumed that the disease is transmitted from the infected population to the susceptible one according to a nonlinear convex incidence rate. The model, based upon the framework of extended thermodynamics, removes the unphysical feature of instantaneous diffusive effects, which is typical of parabolic models. Linear stability analyses are performed to study the nature of the equilibrium states against uniform and nonuniform perturbations. Emphasis is given to the occurrence of Hopf and Turing bifurcations, which break the temporal and the spatial symmetry of the system, respectively. The existence of traveling wave solutions connecting two steady states is also discussed. The governing equations are also integrated numerically to validate the analytical results and to characterize the spatiotemporal evolution of diseases.

Barbera, Elvira; Consolo, Giancarlo; Valenti, Giovanna

2013-11-01

95

Sexually transmitted diseases in Ethiopia. Social factors contributing to their spread and implications for developing countries.  

PubMed

Sexually transmitted diseases in developing countries are causing concern to those responsible for their control and eradication. To gain a better understanding of the problems involved in a country struggling with development, the economic and psychosocial factors influencing the spread of STD in Ethiopia have been studied. Increased migration and urbanisation and the changing role of women have led to a rise in prostitution. Thus changes in the social structure--particularly in relation to the education and employment of women--and improved medical services are essential for the long-term control of STD. PMID:6895708

Plorde, D S

1981-12-01

96

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

NASA Astrophysics Data System (ADS)

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.

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

97

An investigation of auditory contagious yawning  

Microsoft Academic Search

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

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

2009-01-01

98

Spreading of ?-synuclein in the face of axonal transport deficits in Parkinson's disease: A speculative synthesis.  

PubMed

Parkinson's disease (PD) is mainly attributed to degeneration of dopamine neurons in the substantia nigra, but its etiopathogenesis also includes impaired protein clearance and axonal transport dysfunction, among others. The spread of ?-synuclein (?-syn) aggregates from one neuron to another, in a prion-like manner, is hypothesized to contribute to PD progression. Axonal transport is likely to play a crucial role in this movement of ?-syn aggregates between brain regions. At the same time, deficits in axonal transport are suggested to contribute to neuronal failure in PD. In this review, we discuss the apparent contradiction that axonal transport might be essential for disease progression, while dysfunction of axonal transport could simultaneously be a cornerstone of PD pathogenesis. We speculate around models that reconcile how axonal transport can play such a paradoxical role. PMID:25046996

Lamberts, Jennifer T; Hildebrandt, Erin N; Brundin, Patrik

2014-07-15

99

Spread of glomerular to tubulointerstitial disease with a focus on proteinuria.  

PubMed

Chronic kidney disease is characterized by the decline in renal excretory, homeostatic and endocrine functions. In most instances, the primary event is glomerular injury. With ongoing progression and glomerular extracapillary proliferation, tubulointerstitial damage occurs with consequent nephron loss and development of fibrotic lesions, finally resulting in terminal renal failure. Renal tubulointerstitial damage is the final common pathway in all forms of renal disease leading to CKD. Recent research has focused on how glomerular injury spreads to the tubulointerstitium. Presently, four possible mechanisms are being discussed: (1) obstruction of the urinary pole; (2) proteinuria-induced overload of the proximal tubule; (3) chronic hypoxia and (4) inflammation induced by a glomerulotubular feedback loop. Fibrosis is hypothesized to account for further deterioration of renal functions. As to the role of fibrosis, conflicting results have been published and new data question the damaging character of fibrosis. PMID:20400279

Theilig, Franziska

2010-05-20

100

Effects of delayed recovery and nonuniform transmission on the spreading of diseases in complex networks  

NASA Astrophysics Data System (ADS)

We investigate the effects of delaying the time to recovery (delayed recovery) and of nonuniform transmission on the propagation of diseases on structured populations. Through a mean-field approximation and large-scale numerical simulations, we find that postponing the transition from the infectious to the recovered states can largely reduce the epidemic threshold, therefore promoting the outbreak of epidemics. On the other hand, if we consider nonuniform transmission among individuals, the epidemic threshold increases, thus inhibiting the spreading process. When both mechanisms are at work, the latter might prevail, hence resulting in an increase of the epidemic threshold with respect to the standard case, in which both ingredients are absent. Our findings are of interest for a better understanding of how diseases propagate on structured populations and to a further design of efficient immunization strategies.

Xia, Cheng-yi; Wang, Zhen; Sanz, Joaquin; Meloni, Sandro; Moreno, Yamir

2013-04-01

101

An investigation of auditory contagious yawning.  

PubMed

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

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

2009-09-01

102

Transmission of Chronic Wasting Disease in Wisconsin White-Tailed Deer: Implications for Disease Spread and Management  

PubMed Central

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

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

2014-01-01

103

Analytical Modelling of the Spread of Disease in Confined and Crowded Spaces  

NASA Astrophysics Data System (ADS)

Since 1927 and until recently, most models describing the spread of disease have been of compartmental type, based on the assumption that populations are homogeneous and well-mixed. Recent models have utilised agent-based models and complex networks to explicitly study heterogeneous interaction patterns, but this leads to an increasing computational complexity. Compartmental models are appealing because of their simplicity, but their parameters, especially the transmission rate, are complex and depend on a number of factors, which makes it hard to predict how a change of a single environmental, demographic, or epidemiological factor will affect the population. Therefore, in this contribution we propose a middle ground, utilising crowd-behaviour research to improve compartmental models in crowded situations. We show how both the rate of infection as well as the walking speed depend on the local crowd density around an infected individual. The combined effect is that the rate of infection at a population scale has an analytically tractable non-linear dependency on crowd density. We model the spread of a hypothetical disease in a corridor and compare our new model with a typical compartmental model, which highlights the regime in which current models may not produce credible results.

Goscé, Lara; Barton, David A. W.; Johansson, Anders

2014-05-01

104

Predictive Modelling of Contagious Deforestation in the Brazilian Amazon  

PubMed Central

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

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

2013-01-01

105

Weather, host and vector — their interplay in the spread of insect-borne animal virus diseases  

PubMed Central

The spread of insect-borne animal virus diseases is influenced by a number of factors. Hosts migrate, move or are conveyed over long distances: vectors are carried on the wind for varying distances in search of hosts and breeding sites; weather and climate affect hosts and vectors through temperature, moisture and wind. As parasites of host and vector, viruses are carried by animals, birds and insects, and their spread can be correlated with the migration of hosts and the carriage of vectors on winds associated with the movements of the Intertropical Convergence Zone (ITCZ) and warm winds to the north and south of the limits of the ITCZ. The virus is often transmitted from a local cycle to a migratory cycle and back again. Examples of insect-borne virus diseases and their spread are analysed. Japanese, Murray Valley, Western equine, Eastern equine and St Louis encephalitis represent viruses transmitted by mosquito—bird or pig cycles. The areas experiencing infection with these viruses can be divided into a number of zones: A, B, C, D, E and F. In zone A there is a continuous cycle of virus in host and vector throughout the year; in zone B, there is an upsurge in the cycle during the wet season, but the cycle continues during the dry season; there is movement of infected vectors between and within zones A and B on the ITCZ and the virus is introduced to zone C by infected vectors on warm winds; persistence may occur in zone C if conditions are right. In zone D, virus is introduced each year by infected vectors on warm winds and the arrival of the virus coincides with the presence of susceptible nestling birds and susceptible piglets. The disappearance of virus occurs at the time when migrating mosquitoes and birds are returning to warmer climates. The virus is introduced to zone E only on occasions every 5-10 years when conditions are suitable. Infected hosts introduced to zone F do not lead to circulation of virus, since the climate is unsuitable for vectors. Zones A, B and C correspond to endemic and zones D and E to epidemic conditions. Similar zones can be recognized for African horse sickness, bluetongue, Ibaraki disease and bovine ephemeral fever — examples of diseases transmitted in a midge-mammal cycle. In zones A and B viruses are transported by infected midges carried on the wind in association with the movement of ITCZ and undergo cycles in young animals. In these zones and in zone C there is a continual movement of midges on the warm wind between one area and another, colonizing new sites or reinforcing populations of midges already present. Virus is introduced at times into fringe areas (zones D and E) and, as there is little resistance in the host, gives rise to clinical signs of disease. In some areas there is persistence during adverse conditions; in others, the virus is carried back to the endemic zones by infected midges or vectors. Examples of viruses maintained in a mosquito/biting fly—mammal cycle are Venezuelan equine encephalitis and vesicular stomatitis. These viruses enter a migratory cycle from a local cycle and the vectors in the migratory cycle are carried over long distances on the wind. Further examples of virus spread by movement of vectors include West Nile, Rift Valley fever, yellow fever, epizootic haemorrhagic disease of deer and Akabane viruses. In devising means of control it is essential to decide the relationship of host, vector and virus and the nature of the zone in which the area to be controlled lies. Because of the continual risk of reintroduction of infected vectors, it is preferable to protect the host by dipping, spraying or by vaccination rather than attempting to eliminate the local population of insects. PMID:6131919

Sellers, R. F.

1980-01-01

106

Edge-Based Compartmental Modeling for Infectious Disease Spread Part I: An Overview  

E-print Network

The primary tool for predicting infectious disease spread and intervention effectiveness is the mass action Susceptible-Infected-Recovered model of Kermack and McKendrick. Its usefulness derives largely from its conceptual and mathematical simplicity; however, it incorrectly assumes all individuals have the same contact rate and contacts are fleeting. This paper is the first of three investigating edge-based compartmental modeling, a technique eliminating these assumptions. In this paper, we derive simple ordinary differential equation models capturing social heterogeneity (heterogeneous contact rates) while explicitly considering the impact of contact duration. We introduce a graphical interpretation allowing for easy derivation and communication of the model. This paper focuses on the technique and how to apply it in different contexts. The companion papers investigate choosing the appropriate level of complexity for a model and how to apply edge-based compartmental modeling to populations with various sub-...

Miller, Joel C; Volz, Erik M

2011-01-01

107

Epidemic spread of influenza viruses: The impact of transient populations on disease dynamics.  

PubMed

The recent H1N1 ("swine flu") pandemic and recent H5N1 ("avian flu") outbreaks have brought increased attention to the study of the role of animal populations as reservoirs for pathogens that could invade human populations. It is believed that pigs acquired flu strains from birds and humans, acting as a mixing vessel in generating new influenza viruses. Assessing the role of animal reservoirs, particularly reservoirs involving highly mobile populations (like migratory birds), on disease dispersal and persistence is of interests to a wide range of researchers including public health experts and evolutionary biologists. This paper studies the interactions between transient and resident bird populations and their role on dispersal and persistence. A metapopulation framework based on a system of nonlinear ordinary differential equations is used to study the transmission dynamics and control of avian diseases. Simplified versions of mathematical models involving a limited number of migratory and resident bird populations are analyzed. Epidemiological time scales and singular perturbation methods are used to reduce the dimensionality of the model. Our results show that mixing of bird populations (involving residents and migratory birds) play an important role on the patterns of disease spread. PMID:21361408

Ríos-Soto, Karen R; Song, Baojun; Castillo-Chavez, Carlos

2011-01-01

108

Representative contact diaries for modeling the spread of infectious diseases in Taiwan.  

PubMed

Recent studies of infectious diseases have attempted to construct more realistic parameters of interpersonal contact patterns from diary-approach surveys. To ensure that such diary-based contact patterns provide accurate baseline data for policy implementation in densely populated Taiwan, we collected contact diaries from a national sample, using 3-stage systematic probability sampling and rigorous in-person interviews. A representative sample of 1,943 contact diaries recorded a total of 24,265 wide-range, face-to-face interpersonal contacts during a 24-hour period. Nearly 70% of the contacts occurred outside of respondents' households. The most active age group was schoolchildren (ages 5-14), who averaged around 16-18 daily contacts, about 2-3 times as many as the least active age groups. We show how such parameters of contact patterns help modify a sophisticated national simulation system that has been used for years to model the spread of pandemic diseases in Taiwan. Based on such actual and representative data that enable researchers to infer findings to the whole population, our analyses aim to facilitate implementing more appropriate and effective strategies for controlling an emerging or pandemic disease infection. PMID:23056193

Fu, Yang-chih; Wang, Da-Wei; Chuang, Jen-Hsiang

2012-01-01

109

Representative Contact Diaries for Modeling the Spread of Infectious Diseases in Taiwan  

PubMed Central

Recent studies of infectious diseases have attempted to construct more realistic parameters of interpersonal contact patterns from diary-approach surveys. To ensure that such diary-based contact patterns provide accurate baseline data for policy implementation in densely populated Taiwan, we collected contact diaries from a national sample, using 3-stage systematic probability sampling and rigorous in-person interviews. A representative sample of 1,943 contact diaries recorded a total of 24,265 wide-range, face-to-face interpersonal contacts during a 24-hour period. Nearly 70% of the contacts occurred outside of respondents' households. The most active age group was schoolchildren (ages 5–14), who averaged around 16–18 daily contacts, about 2–3 times as many as the least active age groups. We show how such parameters of contact patterns help modify a sophisticated national simulation system that has been used for years to model the spread of pandemic diseases in Taiwan. Based on such actual and representative data that enable researchers to infer findings to the whole population, our analyses aim to facilitate implementing more appropriate and effective strategies for controlling an emerging or pandemic disease infection. PMID:23056193

Fu, Yang-chih; Wang, Da-Wei; Chuang, Jen-Hsiang

2012-01-01

110

Impact of regulatory perturbations to disease spread through cattle movements in Great Britain  

PubMed Central

During the past decade the British livestock industry has suffered from several major pathogen outbreaks, and a variety of regulatory and disease control measures have been applied to the movement of livestock with the express aim of mitigating the spread of infection. The Rapid Analysis and Detection of Animal-related Risks (RADAR) project, which has been collecting data on the movement of cattle since 1998, provides a relatively comprehensive record of how these policies have influenced the movement of cattle between animal holdings, markets, and slaughterhouses in Britain. Many previous studies have focused on the properties of the network that can be derived from these movements – treating farms as nodes and movements as directed (and potentially weighted) edges in the network. However, of far greater importance is how these policy changes have influenced the potential spread of infectious diseases. Here we use a stochastic fully individual-based model of cattle in Britain to assess how the epidemic potential has varied from 2000 to 2009 as the pattern of movements has changed in response to legislation and market forces. Our simulations show that the majority of policy changes lead to significant decreases in the epidemic potential (measured in multiple ways), but that this potential then increases through time as cattle farmers modify their behaviour in response. Our results suggest that the cattle industry is likely to experience boom-bust dynamics, with the actions that farmers take during epidemic-free periods to maximise their profitability likely to increase the potential for large-scale epidemics to occur. PMID:22322159

Vernon, Matthew C.; Keeling, Matt J.

2012-01-01

111

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

PubMed

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

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

2012-06-13

112

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

USGS Publications Warehouse

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.

Henaux, V.; Samuel, M.D.

2011-01-01

113

9 CFR 71.3 - Interstate movement of diseased animals and poultry generally prohibited.  

...with any other disease named in this paragraph...Livestock affected with infectious keratitis or ringworm...with contagious, infectious, or communicable disease to a designated...any contagious, infectious, or communicable disease, or have...

2014-01-01

114

9 CFR 71.3 - Interstate movement of diseased animals and poultry generally prohibited.  

Code of Federal Regulations, 2013 CFR

...with any other disease named in this paragraph...Livestock affected with infectious keratitis or ringworm...with contagious, infectious, or communicable disease to a designated...any contagious, infectious, or communicable disease, or have...

2013-01-01

115

9 CFR 71.3 - Interstate movement of diseased animals and poultry generally prohibited.  

Code of Federal Regulations, 2011 CFR

...with any other disease named in this paragraph...Livestock affected with infectious keratitis or ringworm...with contagious, infectious, or communicable disease to a designated...any contagious, infectious, or communicable disease, or have...

2011-01-01

116

9 CFR 71.3 - Interstate movement of diseased animals and poultry generally prohibited.  

Code of Federal Regulations, 2012 CFR

...with any other disease named in this paragraph...Livestock affected with infectious keratitis or ringworm...with contagious, infectious, or communicable disease to a designated...any contagious, infectious, or communicable disease, or have...

2012-01-01

117

9 CFR 71.3 - Interstate movement of diseased animals and poultry generally prohibited.  

Code of Federal Regulations, 2010 CFR

...with any other disease named in this paragraph...Livestock affected with infectious keratitis or ringworm...with contagious, infectious, or communicable disease to a designated...any contagious, infectious, or communicable disease, or have...

2010-01-01

118

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

PubMed

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

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

2014-01-01

119

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

PubMed

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

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

2014-08-01

120

Computer animations stimulate contagious yawning in chimpanzees  

PubMed Central

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

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

2009-01-01

121

Computer animations stimulate contagious yawning in chimpanzees.  

PubMed

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

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

2009-12-01

122

Minimal Contagious Sets in Random Regular Graphs  

NASA Astrophysics Data System (ADS)

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.

Guggiola, Alberto; Semerjian, Guilhem

2015-01-01

123

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

PubMed Central

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. PMID:24851942

Holme, Petter; Liljeros, Fredrik

2014-01-01

124

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

NASA Astrophysics Data System (ADS)

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.

Holme, Petter; Liljeros, Fredrik

2014-05-01

125

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

PubMed

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. PMID:24851942

Holme, Petter; Liljeros, Fredrik

2014-01-01

126

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

PubMed

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

Bartholomew, Alex J; Cirulli, Elizabeth T

2014-01-01

127

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

PubMed Central

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

Bartholomew, Alex J.; Cirulli, Elizabeth T.

2014-01-01

128

Epitope spreading  

Microsoft Academic Search

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

Carol J Vanderlugt; Stephen D Miller

1996-01-01

129

Commuter Mobility and the Spread of Infectious Diseases: Application to Influenza in France  

PubMed Central

Commuting data is increasingly used to describe population mobility in epidemic models. However, there is little evidence that the spatial spread of observed epidemics agrees with commuting. Here, using data from 25 epidemics for influenza-like illness in France (ILI) as seen by the Sentinelles network, we show that commuting volume is highly correlated with the spread of ILI. Next, we provide a systematic analysis of the spread of epidemics using commuting data in a mathematical model. We extract typical paths in the initial spread, related to the organization of the commuting network. These findings suggest that an alternative geographic distribution of GP accross France to the current one could be proposed. Finally, we show that change in commuting according to age (school or work commuting) impacts epidemic spread, and should be taken into account in realistic models. PMID:24416152

Charaudeau, Segolene; Pakdaman, Khashayar; Boëlle, Pierre-Yves

2014-01-01

130

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

PubMed

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

Provine, Robert R

2014-04-01

131

Smell facilitates auditory contagious yawning in stranger rats.  

PubMed

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

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

2015-01-01

132

Coupling multi-agent model and GIS to simulate pine wood nematode disease spread in ZheJiang Province, China  

NASA Astrophysics Data System (ADS)

A coupled method based on multi-agent model, remote sensing and GIS is described to simulate the forest disease spread. The coupled model focuses on the temporal dynamics of the Bursaphelenchus xylophilus population at the landscape scale. Each individual is modeled as an autonomous agent who behaves according to a set of rules including spreading in the landscape, feeding on Pinus massoniana, sheltering in forest edges and dying, constrained by terrain, land cover and other variables. The model parameters are derived from remote sensing data and field measurements. Ten factors, including damage degree of Pinus Massoniana, altitude and slope, are helped to build the transfer rules. The main outputs are the dynamic disease distribution maps and survived pine population. Our method is applied and validated in DingHai distinct, Zhou Shan city of Zhejiang Province. Three Landsat TM images from the year 1991 to 2006 are used for the pine information extraction. The extracted pine distribution map is used to compare with the simulated surviving pine map. The results show that the coupled model can produce reasonable results and be used as a virtual experiment tool. However, it is difficult to simulate the human activities to help or prevent disease spread and the long fly behavior of insect vectors. Therefore, there still exists some difference between the simulated results and the real data. At the next step, those factors will be considered.

Huang, Huaguo; Wang, Lei; Zhang, XiaoLi; Luo, YouQing; Zhao, Liqiong

2008-10-01

133

Contagious Yawning and Seasonal Climate Variation  

PubMed Central

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

Gallup, Andrew C.; Eldakar, Omar Tonsi

2011-01-01

134

Contagious yawning and seasonal climate variation.  

PubMed

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

Gallup, Andrew C; Eldakar, Omar Tonsi

2011-01-01

135

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

NASA Astrophysics Data System (ADS)

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.

Huq, A.; Colwell, R.

2011-12-01

136

Extracellular matrix constituents interfere with Newcastle disease virus spread in solid tissue and diminish its potential oncolytic activity.  

PubMed

Advanced melanoma cells, characterized by resistance to chemotherapy, have been shown to be highly sensitive to oncolysis by Newcastle disease virus (NDV). In the present study, we investigated the capacity of NDV to specifically infect and spread into solid tissues of human melanoma and lung carcinoma, in vivo and ex vivo. For this purpose a new model of SCID-beige mice implanted with human melanoma was developed. Surprisingly, the replication competent NDV-MTH and the attenuated, single-cycle replication NDV-HUJ strains, demonstrated a similar oncolytic activity in the melanoma-implanted mice. Further, ex vivo analysis, using organ cultures derived from the melanoma tissues indicated a limited spread of the two NDV strains in the tissue. Extracellular matrix (ECM) molecules, notably heparin sulfate and collagen, were found to limit viral spread in the tissue. This observation was validated with yet another solid tumour of human lung carcinoma. Taken together, the results indicate that the ECM acts as a barrier to virus spread within solid tumour tissues and that this restriction must be overcome to achieve effective oncolysis with NDV. PMID:22622327

Yaacov, Barak; Lazar, Itay; Tayeb, Shay; Frank, Sivan; Izhar, Uzi; Lotem, Michal; Perlman, Riki; Ben-Yehuda, Dina; Zakay-Rones, Zichria; Panet, Amos

2012-08-01

137

Measures of concurrency in networks and the spread of infectious disease  

Microsoft Academic Search

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

Martina Morris

1996-01-01

138

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

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

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

2013-10-01

139

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

USGS Publications Warehouse

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.

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

140

Absence of contagious yawning in children with autism spectrum disorder.  

PubMed

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

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

2007-12-22

141

Lognormal Infection Times of Online Information Spread  

PubMed Central

The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual participants. Experimental measurements support the lognormal shape of the individual contributing processes, and have resemblance to previously reported lognormal distributions of human behavior and contagious processes. PMID:23700473

Doerr, Christian; Blenn, Norbert; Van Mieghem, Piet

2013-01-01

142

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

PubMed Central

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

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

2013-01-01

143

The development of pathogen resistance in Daphnia magna: implications for disease spread in age-structured populations.  

PubMed

Immunity in vertebrates is well established to develop with time, but the ontogeny of defence in invertebrates is markedly less studied. Yet, age-specific capacity for defence against pathogens, coupled with age structure in populations, has widespread implications for disease spread. Thus, we sought to determine the susceptibility of hosts of different ages in an experimental invertebrate host-pathogen system. In a series of experiments, we show that the ability of Daphnia magna to resist its natural bacterial pathogen Pasteuria ramosa changes with host age. Clonal differences make it difficult to draw general conclusions, but the majority of observations indicate that resistance increases early in the life of D. magna, consistent with the idea that the defence system develops with time. Immediately following this, at about the time when a daphnid would be most heavily investing in reproduction, resistance tends to decline. Because many ecological factors influence the age structure of Daphnia populations, our results highlight a broad mechanism by which ecological context can affect disease epidemiology. We also show that a previously observed protective effect of restricted maternal food persists throughout the entire juvenile period, and that the protective effect of prior treatment with a small dose of the pathogen ('priming') persists for 7 days, observations that reinforce the idea that immunity in D. magna can change over time. Together, our experiments lead us to conclude that invertebrate defence capabilities have an ontogeny that merits consideration with respect to both their immune systems and the epidemic spread of infection. PMID:25214486

Garbutt, Jennie S; O'Donoghue, Anna J P; McTaggart, Seanna J; Wilson, Philip J; Little, Tom J

2014-11-01

144

Spread of citrus huanglongbing (greening disease) following incursion into Papua New Guinea  

Microsoft Academic Search

Huanglongbing (HLB) was previously known in many countries as greening disease. It is caused by the bacterium ‘Candidates Liberibacter asiaticus’ and is vectored by the Asian citrus psyllid Diaphorina citri (Hemiptera: Psyllidae). A delimiting survey showed that the disease had become established in, and near the border town of,\\u000a Vanimo in the Sandaun Province of Papua New Guinea (PNG) by

R. I. Davis; T. G. Gunua; M. F. Kame; D. Tenakanai; T. K. Ruabete

2005-01-01

145

Contagious mucocutaneous dermatitis of the mountain hare (Lepus timidus): pathology and cause.  

PubMed

Contagious mucocutaneous dermatitis is a frequently encountered disease of mountain hares (Lepidus timidus) in Finland. We describe the histopathologic changes and propose an etiologic cause for this disorder. Fifty-three cases collected during 1982-2000 were examined histologically. Transmission electron microscopy was performed in one case. In fully developed lesions, keratinocytes in epidermis and follicular infundibula were swollen and contained large eosinophilic intracytoplasmic inclusion bodies with marked reticular and ballooning degeneration. In later stages, there was marked necrosis and ulceration with severe pyogranulomatous and suppurative inflammation. At this stage, no viral inclusions were detectable, but secondary Staphylococcus warnerii infection was present in most cases. In late lesions, there was dermal fibrosis with epidermal hyperplasia. No spiral-shaped bacteria suggesting treponematosis were detected at any stage. Ultrastructurally, swollen epidermal and follicle infundibular cells contained round intracytoplasmic inclusion bodies with a myriad of virions typical of poxvirus with a biconcave nucleocapsid core, two lateral bodies, and a clearly discernible outer lipoprotein capsule. The findings suggest that contagious mucocutaneous dermatitis in mountain hares is a viral disease caused by a poxvirus. The disease is often complicated by secondary bacterial infection, most commonly S. warneri. PMID:16456167

Saari, Seppo A M; Rudbäck, Eeva; Niskanen, Mirjami; Syrjälä, Paula; Nylund, Minna; Anttila, Marjukka

2005-10-01

146

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

Microsoft Academic Search

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

Steven M. Platek

2010-01-01

147

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

Microsoft Academic Search

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

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

2003-01-01

148

Yearning to yawn: the neural basis of contagious yawning  

Microsoft Academic Search

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

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

2005-01-01

149

Absence of contagious yawning in children with autism spectrum disorder  

Microsoft Academic Search

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

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

2007-01-01

150

Methodological Problems in the Study of Contagious Yawning  

Microsoft Academic Search

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

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

2010-01-01

151

CONTAGIOUS ECTHYMA IN MOUNTAIN GOAT OF COASTAL BRITISH COLUMBIA11  

Microsoft Academic Search

Contagious ecthyma has been reported previously from mountain goat (Oreamnnos 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

D. M. HEBERT; M. SAMUEL; G. W. SMITH

152

Contagious ecthyma in mountain goat of coastal British Columbia.  

PubMed

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

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

1977-04-01

153

The network of sheep movements within Great Britain: network properties and their implications for infectious disease spread  

PubMed Central

During the 2001 foot and mouth disease epidemic in the UK, initial dissemination of the disease to widespread geographical regions was attributed to livestock movement, especially of sheep. In response, recording schemes to provide accurate data describing the movement of large livestock in Great Britain (GB) were introduced. Using these data, we reconstruct directed contact networks within the sheep industry and identify key epidemiological properties of these networks. There is clear seasonality in sheep movements, with a peak of intense activity in August and September and an associated high risk of a large epidemic. The high correlation between the in and out degree of nodes favours disease transmission. However, the contact networks were largely dissasortative: highly connected nodes mostly connect to nodes with few contacts, effectively slowing the spread of disease. This is a result of bipartite-like network properties, with most links occurring between highly active markets and less active farms. When comparing sheep movement networks (SMNs) to randomly generated networks with the same number of nodes and node degrees, despite structural differences (such as disassortativity and higher frequency of even path lengths in the SMNs), the characteristic path lengths within the SMNs are close to values computed from the corresponding random networks, showing that SMNs have ‘small-world’-like properties. Using the network properties, we show that targeted biosecurity or surveillance at highly connected nodes would be highly effective in preventing a large and widespread epidemic. PMID:16971335

Kiss, Istvan Z; Green, Darren M; Kao, Rowland R

2006-01-01

154

Disease risk mitigation: The equivalence of two selective mixing strategies on aggregate contact patterns and resulting epidemic spread.  

PubMed

The personal choices affecting the transmission of infectious diseases include the number of contacts an individual makes, and the risk-characteristics of those contacts. We consider whether these different choices have distinct implications for the course of an epidemic. We also consider whether choosing contact mitigation (how much to mix) and affinity mitigation (with whom to mix) strategies together has different epidemiological effects than choosing each separately. We use a set of differential equation compartmental models of the spread of disease, coupled with a model of selective mixing. We assess the consequences of varying contact or affinity mitigation as a response to disease risk. We do this by comparing disease incidence and dynamics under varying contact volume, contact type, and both combined across several different disease models. Specifically, we construct a change of variables that allows one to transition from contact mitigation to affinity mitigation, and vice versa. In the absence of asymptomatic infection we find no difference in the epidemiological impacts of the two forms of disease risk mitigation. Furthermore, since models that include both mitigation strategies are underdetermined, varying both results in no outcome that could not be reached by choosing either separately. Which strategy is actually chosen then depends not on their epidemiological consequences, but on the relative cost of reducing contact volume versus altering contact type. Although there is no fundamental epidemiological difference between the two forms of mitigation, the social cost of alternative strategies can be very different. From a social perspective, therefore, whether one strategy should be promoted over another depends on economic not epidemiological factors. PMID:25150459

Morin, Benjamin R; Perrings, Charles; Levin, Simon; Kinzig, Ann

2014-12-21

155

Indirect Genetic Effects and the Spread of Infectious Disease: Are We Capturing the Full Heritable Variation Underlying Disease Prevalence?  

PubMed Central

Reducing disease prevalence through selection for host resistance offers a desirable alternative to chemical treatment. Selection for host resistance has proven difficult, however, due to low heritability estimates. These low estimates may be caused by a failure to capture all the relevant genetic variance in disease resistance, as genetic analysis currently is not taylored to estimate genetic variation in infectivity. Host infectivity is the propensity of transmitting infection upon contact with a susceptible individual, and can be regarded as an indirect effect to disease status. It may be caused by a combination of physiological and behavioural traits. Though genetic variation in infectivity is difficult to measure directly, Indirect Genetic Effect (IGE) models, also referred to as associative effects or social interaction models, allow the estimation of this variance from more readily available binary disease data (infected/non-infected). We therefore generated binary disease data from simulated populations with known amounts of variation in susceptibility and infectivity to test the adequacy of traditional and IGE models. Our results show that a conventional model fails to capture the genetic variation in infectivity inherent in populations with simulated infectivity. An IGE model, on the other hand, does capture some of the variation in infectivity. Comparison with expected genetic variance suggests that there is scope for further methodological improvement, and that potential responses to selection may be greater than values presented here. Nonetheless, selection using an index of estimated direct and indirect breeding values was shown to have a greater genetic selection differential and reduced future disease risk than traditional selection for resistance only. These findings suggest that if genetic variation in infectivity substantially contributes to disease transmission, then breeding designs which explicitly incorporate IGEs might help reduce disease prevalence. PMID:22768088

Lipschutz-Powell, Debby; Woolliams, John A.; Bijma, Piter; Doeschl-Wilson, Andrea B.

2012-01-01

156

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

NSDL National Science Digital Library

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.

157

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

PubMed Central

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

Kumar, Amit; Rahal, Anu; Verma, Amit Kumar

2014-01-01

158

Predicting ectotherm disease vector spread—benefits from multidisciplinary approaches and directions forward  

NASA Astrophysics Data System (ADS)

The occurrence of ectotherm disease vectors outside of their previous distribution area and the emergence of vector-borne diseases can be increasingly observed at a global scale and are accompanied by a growing number of studies which investigate the vast range of determining factors and their causal links. Consequently, a broad span of scientific disciplines is involved in tackling these complex phenomena. First, we evaluate the citation behaviour of relevant scientific literature in order to clarify the question "do scientists consider results of other disciplines to extend their expertise?" We then highlight emerging tools and concepts useful for risk assessment. Correlative models (regression-based, machine-learning and profile techniques), mechanistic models (basic reproduction number R 0) and methods of spatial regression, interaction and interpolation are described. We discuss further steps towards multidisciplinary approaches regarding new tools and emerging concepts to combine existing approaches such as Bayesian geostatistical modelling, mechanistic models which avoid the need for parameter fitting, joined correlative and mechanistic models, multi-criteria decision analysis and geographic profiling. We take the quality of both occurrence data for vector, host and disease cases, and data of the predictor variables into consideration as both determine the accuracy of risk area identification. Finally, we underline the importance of multidisciplinary research approaches. Even if the establishment of communication networks between scientific disciplines and the share of specific methods is time consuming, it promises new insights for the surveillance and control of vector-borne diseases worldwide.

Thomas, Stephanie Margarete; Beierkuhnlein, Carl

2013-05-01

159

Personalized ventilation as a control measure for airborne transmissible disease spread  

PubMed Central

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

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

2009-01-01

160

The SIS Model of Epidemic Spreading in a Hierarchical Social Network  

NASA Astrophysics Data System (ADS)

The phenomenon of epidemic spreading in a population with a hierarchical structure of interpersonal interactions is described and investigated numerically. The SIS model with temporal immunity to a disease and a time of incubation is used. In our model spatial localization of individuals belonging to different social groups, effectiveness of different interpersonal interactions and the mobility of a contemporary community are taken into account. The structure of interpersonal connections is based on a scale-free network. The influence of the structure of the social network on typical relations characterizing the spreading process, like a range of epidemic and epidemic curves, is discussed. The probability that endemic state occurs is also calculated. Surprisingly it occurs, that less contagious diseases has greater chance to survive. The influence of preventive vaccinations on the spreading process is investigated and critical range of vaccinations that is sufficient for the suppression of an epidemic is calculated. Our results of numerical calculations are compared with the solutions of the master equation for the spreading process, and good agreement is found.

Grabowski, A.; Kosinski, R. A.

2005-05-01

161

Spread of Vector-borne Diseases and Neglect of Leishmaniasis, Europe  

PubMed Central

The risk for reintroduction of some exotic vector-borne diseases in Europe has become a hot topic, while the reality of others is neglected at the public health policy level. Leishmaniasis is endemic in all southern countries of Europe, with ?700 autochthonous human cases reported each year (3,950 if Turkey is included). Asymptomatic cases have been estimated at 30–100/1 symptomatic case, and leishmaniasis has up to 25% seroprevalence in domestic dogs. Even though leishmaniasis is essentially associated with Leishmania infantum and visceral leishmaniasis, new species, such as L. donovani and L. tropica, might colonize European sand fly vectors. Drug-resistant L. infantum strains might be exported outside Europe through dogs. Despite this possibility, no coordinated surveillance of the disease exists at the European level. In this review of leishmaniasis importance in Europe, we would like to bridge the gap between research and surveillance and control. PMID:18598618

Campino, Lenea; Cańavate, Carmen; Dedet, Jean-Pierre; Gradoni, Luigi; Soteriadou, Ketty; Mazeris, Apostolos; Ozbel, Yusuf; Boelaert, Marleen

2008-01-01

162

Comparative effects of avoidance and vaccination in disease spread on a dynamic small-world network  

NASA Astrophysics Data System (ADS)

Dynamic small-world contact networks have fixed short range links and time-varying stochastic long range links. They are used to model mobile populations or as minimal models for traditional small-world networks. Here we study the relative effects of vaccinations and avoidance of infected individuals in a susceptible-infected-recovered (SIR) epidemic model on a dynamic small-world network. We derive the critical mobility required for an outbreak to occur as a function of the disease’s infectivity, recovery rate, avoidance rate, and vaccination rate. We also derive an expression that allows us to calculate the amount of vaccination and/or avoidance necessary to prevent an epidemic. Calculated quantities show excellent agreement with simulations.

Stone, Thomas E.; Jones, Matthew M.; McKay, Susan R.

2010-12-01

163

Spreading of pathology in neurodegenerative diseases: a focus on human studies.  

PubMed

The progression of many neurodegenerative diseases is thought to be driven by the template-directed misfolding, seeded aggregation and cell-cell transmission of characteristic disease-related proteins, leading to the sequential dissemination of pathological protein aggregates. Recent evidence strongly suggests that the anatomical connections made by neurons - in addition to the intrinsic characteristics of neurons, such as morphology and gene expression profile - determine whether they are vulnerable to degeneration in these disorders. Notably, this common pathogenic principle opens up opportunities for pursuing novel targets for therapeutic interventions for these neurodegenerative disorders. We review recent evidence that supports the notion of neuron-neuron protein propagation, with a focus on neuropathological and positron emission tomography imaging studies in humans. PMID:25588378

Brettschneider, Johannes; Del Tredici, Kelly; Lee, Virginia M-Y; Trojanowski, John Q

2015-02-01

164

Spreading of pathology in neurodegenerative diseases: a focus on human studies  

PubMed Central

The progression of many neurodegenerative diseases is thought to be driven by the template-directed misfolding, seeded aggregation and cell–cell transmission of characteristic disease-related proteins, leading to the sequential dissemination of pathological protein aggregates. Recent evidence strongly suggests that the anatomical connections made by neurons — in addition to the intrinsic characteristics of neurons, such as morphology and gene expression profile — determine whether they are vulnerable to degeneration in these disorders. Notably, this common pathogenic principle opens up opportunities for pursuing novel targets for therapeutic interventions for these neurodegenerative disorders. We review recent evidence that supports the notion of neuron–neuron protein propagation, with a focus on neuropathological and positron emission tomography imaging studies in humans. PMID:25588378

Brettschneider, Johannes; Del Tredici, Kelly; Lee, Virginia M.-Y.; Trojanowski, John Q.

2015-01-01

165

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

PubMed Central

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

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

2014-01-01

166

Immunizing against Prejudice: Effects of Disease Protection on Attitudes toward out-Groups  

E-print Network

Contemporary interpersonal biases are partially derived from psychological mechanisms that evolved to protect people against the threat of contagious disease. This behavioral immune system effectively promotes disease ...

Ackerman, Joshua

167

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

PubMed Central

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.

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

2011-01-01

168

Spread of ticks and tick-borne diseases in Germany due to global warming.  

PubMed

Tick-transmitted diseases like tick-borne encephalitis and Lyme Borreliosis have been well known in Germany for decades. Global climate changes may influence the emergence and reemergence of diseases. Ongoing research now gives an additional focus on other tick-borne pathogens such as Coxiella burnetii, Rickettsia conorii, Anaplasma phagocytophilum and Babesia spp., the causative agents of Q-fever, Mediterranean spotted fever, Anaplasmosis and Babesiosis, respectively. The epidemiology of these pathogens was investigated on ticks as well as on rodents, the main hosts. Therefore adults of Dermacentor spp. (n = 862) and rodents (n = 119) were collected and examined for the existence of C. burnetii and Rickettsia spp. by polymerase chain reaction (PCR). In none of the ticks and rodents C. burnetii could be detected, in contrast to Rickettsia spp. where the infection rate in ticks was about 20%. Over and above that, nymphs and adults of Ixodes ricinus were also collected and investigated by PCR for A. phagocytophilum (n = 5,424), Rickettsia helvetica (n = 1,187) and Babesia spp. (n = 3,113). Thereby infection rates of 1%, 8.9% and 1%, respectively, could be determined. The prevalence in rodents was 5.3% for A. phagocytophilum and 0.8% for Babesia microti. None of the rodents was R. helvetica positive. PMID:19030892

Hartelt, Kathrin; Pluta, Silvia; Oehme, Rainer; Kimmig, Peter

2008-12-01

169

Molecular evolutionary signatures reveal the role of host ecological dynamics in viral disease emergence and spread  

PubMed Central

RNA viruses account for numerous emerging and perennial infectious diseases, and are characterized by rapid rates of molecular evolution. The ecological dynamics of most emerging RNA viruses are still poorly understood and difficult to ascertain. The availability of genome sequence data for many RNA viruses, in principle, could be used to infer ecological dynamics if changes in population numbers produced a lasting signature within the pattern of genome evolution. As a result, the rapidly emerging phylogeographic structure of a pathogen, shaped by the rise and fall in the number of infections and their spatial distribution, could be used as a surrogate for direct ecological assessments. Based on rabies virus as our example, we use a model combining ecological and evolutionary processes to test whether variation in the rate of host movement results in predictive diagnostic patterns of pathogen genetic structure. We identify several linearizable relationships between host dispersal rate and measures of phylogenetic structure suggesting genetic information can be used to directly infer ecological process. We also find phylogenetic structure may be more revealing than demography for certain ecological processes. Our approach extends the reach of current analytic frameworks for infectious disease dynamics by linking phylogeography back to underlying ecological processes. PMID:23382419

Duke-Sylvester, Scott M.; Biek, Roman; Real, Leslie A.

2013-01-01

170

Methodological problems in the study of contagious yawning.  

PubMed

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

Campbell, Matthew W; de Waal, Frans B M

2010-01-01

171

Presence of contagious yawning in children with autism spectrum disorder.  

PubMed

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

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

2013-01-01

172

Presence of Contagious Yawning in Children with Autism Spectrum Disorder  

PubMed Central

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

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

2013-01-01

173

Alveolar echinococcosis-spreading disease challenging clinicians: a case report and literature review.  

PubMed

Human alveolar echinococcosis (AE) is a potentially deadly disease; recent studies have shown that the endemic area of Echinococcus multilocularis, its causative agent, is larger than previously known. This disease has low prevalence and remains underreported in Europe. Emerging clinical data show that diagnostic difficulties are still common. We report on a 76-year old patient suffering from AE lesions restricted to the left lobe of the liver who underwent a curative extended left hemihepatectomy. Prior to the resection a liver biopsy under the suspicion of an atypical malignancy was performed. After the intervention he developed a pseudoaneurysm of the hepatic artery that was successfully coiled. Surprisingly, during surgery, the macroscopic appearance of the tumour revealed a growth pattern that was rather typical for cystic echinococcosis (CE), i.e., a gross tumour composed of multiple large vesicles with several centimeters in diameter. In addition, there were neither extensive adhesions nor infiltrations of the neighboring pancreas and diaphragm as was expected from previous imaging results. The unexpected diagnosis of AE was confirmed by definite histopathology, specific polymerase chain reaction and serology results. This is a rare case of unusual macroscopic presentation of AE that posed immense diagnostic challenges and had an eventful course. To our knowledge this is the first case of an autochthonous infection in this particular geographic area of Germany, the federal state of Saxony. This report may provide new hints for an expanding area of risk for AE and emphasizes the risk of complications in the scope of diagnostic procedures and the limitations of modern radiological imaging. PMID:23864792

Atanasov, Georgi; Benckert, Christoph; Thelen, Armin; Tappe, Dennis; Frosch, Matthias; Teichmann, Dieter; Barth, Thomas F E; Wittekind, Christian; Schubert, Stefan; Jonas, Sven

2013-07-14

174

Yearning to yawn: the neural basis of contagious yawning.  

PubMed

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

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

2005-02-15

175

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

PubMed

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

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

2014-10-01

176

Changing social contact patterns under tropical weather conditions relevant for the spread of infectious diseases.  

PubMed

SUMMARY Weather conditions and social contact patterns provide some clues to understanding year-round influenza epidemics in the tropics. Recent studies suggest that contact patterns may direct influenza transmission in the tropics as critically as the aerosol channel in temperate regions. To examine this argument, we analysed a representative nationwide survey dataset of contact diaries with comprehensive weather data in Taiwan. Methods we used included model-free estimated relative changes in reproduction number, R 0; relative changes in the number of contacts; and model-based estimated relative changes in mean contacts using zero-inflated negative binomial regression models. Overall, social contact patterns clearly differ by demographics (such as age groups), personal idiosyncrasies (such as personality and happiness), and social institutions (such as the division of weekdays and weekend days). Further, weather conditions also turn out to be closely linked to contact patterns under various circumstances. Fleeting contacts, for example, tend to diminish when it rains hard on weekdays, while physical contacts also decrease during weekend days with heavy rain. Frequent social contacts on weekdays and under good weather conditions, including high temperature and low absolute humidity, all might facilitate the transmission of infectious diseases in tropical regions. PMID:24725605

Chan, T-C; Fu, Y-C; Hwang, J-S

2015-01-01

177

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

PubMed Central

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

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

2008-01-01

178

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

Accepté pour publication dans Journal of Wildlife Diseases le 2 Juillet 2008 1 IS LEPROSY SPREADING: (email: jloughry@valdosta.edu) phone: 229-333-5765, FAX: 229- 245-6585 Running Head: LOUGHRY ET AL.---LEPROSY persistently high levels of leprosy infection, and (2) a small group of animals released from captivity

Paris-Sud XI, Université de

179

POST-HURRICANE ANALYSIS OF CITRUS CANKER II: PREDICTIVE MODEL ESTIMATION OF DISEASE SPREAD AND AREA POTENTIALLY IMPACTED BY VARIOUS ERADICATION PROTOCOLS FOLLOWING CATASTROPHIC WEATHER EVENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The affect of 2005 Hurricane Wilma on the dissemination of Xanthomonas axonopodis pv. citri (Xac), the cause of Asiatic citrus canker (ACC), and subsequent disease development was examined and predictions for the areas into which Xac was likely to have spread from known sources of infection was deve...

180

Demodex gatoi -associated contagious pruritic dermatosis in cats - a report from six households in Finland  

PubMed Central

Background Demodex gatoi is unique among demodectic mites. It possesses a distinct stubby appearance, and, instead of residing in the hair follicles, it dwells in the keratin layer of the epidermis, causing a pruritic and contagious skin disease in cats. Little is known of the occurrence of D. gatoi in Europe or control of D. gatoi infestation. Case presentation We describe D. gatoi in 10 cats, including five Cornish Rex, two Burmese, one Exotic, one Persian and one Siamese, living in six multi-cat households in different locations in Finland containing 21 cats in total. Intense pruritus was the main clinical sign. Scaling, broken hairs, alopecia and self-inflicted excoriations were also observed. Diagnosis was based on finding typical short-bodied demodectic mites in skin scrapings, skin biopsies or on tape strips. Other pruritic skin diseases, such as allergies and dermatophytoses, were ruled out. In one household, despite finding several mites on one cat, all six cats of the household remained symptomless. Amitraz used weekly at a concentration of 125-250 ppm for 2-3 months, proved successful in three households, 2% lime sulphur weekly dips applied for six weeks in one household and peroral ivermectin (1 mg every other day for 10 weeks) in one household. Previous trials in four households with imidacloprid-moxidectin, selamectin or injected ivermectin given once or twice a month appeared ineffective. Conclusion D. gatoi-associated dermatitis is an emerging contagious skin disease in cats in Finland. Although pruritus is common, some cats may harbour the mites without clinical signs. In addition, due to translucency of the mites and fastidious feline grooming habits, the diagnosis may be challenging. An effective and convenient way to treat D. gatoi infestations has yet to emerge. PMID:19843334

Saari, Seppo AM; Juuti, Kirsi H; Palojärvi, Joanna H; Väisänen, Kirsi M; Rajaniemi, Riitta-Liisa; Saijonmaa-Koulumies, Leena E

2009-01-01

181

Contagious yawning and the frontal lobe: an fMRI study.  

PubMed

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

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

2009-05-01

182

Contagious Yawning and the Frontal Lobe: An fMRI Study  

PubMed Central

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

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

2014-01-01

183

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

Microsoft Academic Search

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

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

2009-01-01

184

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

PubMed

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

Platek, Steven M

2010-01-01

185

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

PubMed

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

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

1975-01-01

186

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

PubMed

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

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

2014-09-17

187

Efficient detection of contagious outbreaks in massive metropolitan encounter networks  

NASA Astrophysics Data System (ADS)

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 time-resolved physical contact network, consisting of 1 billion contacts among 3 million transit users. Here, we study the advantage that knowledge of such co-presence structures may provide for early detection of contagious outbreaks. We first examine the ``friend sensor'' scheme - a simple, but universal strategy requiring only local information - and demonstrate that it provides significant early detection of simulated outbreaks. Taking advantage of the full network structure, we then identify advanced ``global sensor sets'', obtaining substantial early warning times savings over the friends sensor scheme. Individuals with highest number of encounters are the most efficient sensors, with performance comparable to individuals with the highest travel frequency, exploratory behavior and structural centrality. An efficiency balance emerges when testing the dependency on sensor size and evaluating sensor reliability; we find that substantial and reliable lead-time could be attained by monitoring only 0.01% of the population with the highest degree.

Sun, Lijun; Axhausen, Kay W.; Lee, Der-Horng; Cebrian, Manuel

2014-06-01

188

Hitting Is Contagious in Baseball: Evidence from Long Hitting Streaks  

PubMed Central

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

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

2012-01-01

189

Efficient detection of contagious outbreaks in massive metropolitan encounter networks  

PubMed Central

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 time-resolved physical contact network, consisting of 1 billion contacts among 3 million transit users. Here, we study the advantage that knowledge of such co-presence structures may provide for early detection of contagious outbreaks. We first examine the “friend sensor” scheme - a simple, but universal strategy requiring only local information - and demonstrate that it provides significant early detection of simulated outbreaks. Taking advantage of the full network structure, we then identify advanced “global sensor sets”, obtaining substantial early warning times savings over the friends sensor scheme. Individuals with highest number of encounters are the most efficient sensors, with performance comparable to individuals with the highest travel frequency, exploratory behavior and structural centrality. An efficiency balance emerges when testing the dependency on sensor size and evaluating sensor reliability; we find that substantial and reliable lead-time could be attained by monitoring only 0.01% of the population with the highest degree. PMID:24903017

Sun, Lijun; Axhausen, Kay W.; Lee, Der-Horng; Cebrian, Manuel

2014-01-01

190

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

Microsoft Academic Search

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

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

2011-01-01

191

Marek’s disease virus and skin interactions  

PubMed Central

Marek’s disease virus (MDV) is a highly contagious herpesvirus which induces T-cell lymphoma in the chicken. This virus is still spreading in flocks despite forty years of vaccination, with important economical losses worldwide. The feather follicles, which anchor feathers into the skin and allow their morphogenesis, are considered as the unique source of MDV excretion, causing environmental contamination and disease transmission. Epithelial cells from the feather follicles are the only known cells in which high levels of infectious mature virions have been observed by transmission electron microscopy and from which cell-free infectious virions have been purified. Finally, feathers harvested on animals and dust are today considered excellent materials to monitor vaccination, spread of pathogenic viruses, and environmental contamination. This article reviews the current knowledge on MDV-skin interactions and discusses new approaches that could solve important issues in the future. PMID:24694064

2014-01-01

192

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

PubMed

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

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

2012-01-01

193

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

PubMed

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

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

2003-07-01

194

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

PubMed Central

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

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

2014-01-01

195

Adjuvants for foot-and-mouth disease virus vaccines: recent progress.  

PubMed

Foot-and-mouth disease (FMD) is a highly contagious and rapidly spreading disease of cloven-hoofed animals. In most countries, animals are immunized with inactivated whole virus vaccines to control the spread of foot-and-mouth disease virus (FMDV); however, there are safety and efficacy (especially, cell-mediated immunity) concerns. Many efforts are currently devoted to the development of effective vaccines by combining the application of protective antigens together with the search for specific and targeting adjuvants that maximizes the immunogenicity with a desired immune response. In this review, we outline previous studies performed with both traditional adjuvants as well as the most promising new generation adjuvants such as ligands for Toll-like receptors (TLRs) or different cytokines, focusing mostly on their efficacy when used with FMD vaccine, and somewhat on mechanisms by which adjuvants mediate their effects. PMID:25234962

Cao, Yimei

2014-11-01

196

Survival of contagious equine metritis bacteria in transport media.  

PubMed

Survival of bacteria that cause contagious equine metritis (CEM) was evaluated in Amies modified transport (AMT) medium, in AMT medium with charcoal, and in Stuart transport medium at 37, 22, 4, and -70 C. The CEM bacteria suspended in transport media survived at 22, 4, and -70 C for longer periods in AMT medium with charcoal than they did in AMT and Stuart transport media. In 1 day, the number of bacteria in exudate stored in the absence of any transport medium decreased 15-fold at 22 C and twofold at 4 C. The CEM bacteria were isolated from exudate on cotton-tipped swabs from all three transport media at 4 and -70 C on day 10, the termination of the experiment. However at 4 C, the survival of CEM bacteria was greater in AMT medium with charcoal than it was in AMT and Stuart transport media. PMID:507491

Sahu, S P; Dardiri, A H; Rommel, F A; Pierson, R E

1979-07-01

197

Hitting is contagious in baseball: evidence from long hitting streaks.  

PubMed

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 [Formula: see text] streaks of length [Formula: see text] games, including a total [Formula: see text] observations were compiled. Treatment and control sample groups ([Formula: see text]) were constructed from core lineups of players on the streaking batter's team. The percentile method bootstrap was used to calculate [Formula: see text] 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 [Formula: see text] for the treatment group was found to be [Formula: see text] to [Formula: see text] percentage points higher during hot streaks (mean difference increased [Formula: see text] points), while the batting heat index [Formula: see text] introduced here was observed to increase by [Formula: see text] points. For each performance statistic, the null hypothesis was rejected at the [Formula: see text] 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

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

2012-01-01

198

Is obesity contagious by way of body image? A study on Japanese female students in the United States.  

PubMed

Although it has been suggested that obesity is 'contagious' within the social network, direct cause of this spread of obesity remains unclear. This study hypothesized that Body Image (BI), the perception of one's own body size, may play a role in this obesity spread, since a high prevalence of obesity could shift people's perception of 'what is normal'. Young Japanese females (n = 53) were interviewed within 1 month after moving to New York City, where the prevalence of obesity is substantially higher than that of their home country, Japan. Each participant was examined for her BI in terms of current body size (CBS) and ideal body size (IBS). They were interviewed again 2 months after the first examination. Between the two interviews, the participants' CBS was decreased (having thinner self-image), while the IBS increased (having fatter ideal-image), leading to less dissatisfaction (smaller CBS-IBS) with their body size. These results suggest that one's BI could change in a period as short as 2 months, possibly because of being surrounded by more obese people. The IBS change was positively associated with BMI change (increased by 0.4 ± 0.6 kg/m˛), warranting further study on the role of BI in the spread of obesity. PMID:23564365

Bagrowicz, Rinako; Watanabe, Chiho; Umezaki, Masahiro

2013-10-01

199

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

PubMed

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

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

1983-07-01

200

Development of a Discrete Spatial-Temporal SEIR Simulator for Modeling Infectious Diseases  

SciTech Connect

Multiple techniques have been developed to model the temporal evolution of infectious diseases. Some of these techniques have also been adapted to model the spatial evolution of the disease. This report examines the application of one such technique, the SEIR model, to the spatial and temporal evolution of disease. Applications of the SEIR model are reviewed briefly and an adaptation to the traditional SEIR model is presented. This adaptation allows for modeling the spatial evolution of the disease stages at the individual level. The transmission of the disease between individuals is modeled explicitly through the use of exposure likelihood functions rather than the global transmission rate applied to populations in the traditional implementation of the SEIR model. These adaptations allow for the consideration of spatially variable (heterogeneous) susceptibility and immunity within the population. The adaptations also allow for modeling both contagious and non-contagious diseases. The results of a number of numerical experiments to explore the effect of model parameters on the spread of an example disease are presented.

McKenna, S.A.

2000-11-01

201

Spill Spread  

NSDL National Science Digital Library

In this simulation, learners explore how ocean currents spread all kinds of pollutionâincluding oil spills, sewage, pesticides and factory wasteâfar 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.

Science, Lawrence H.

2007-01-01

202

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)

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.

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

203

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)

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.

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

204

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...

205

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

PubMed Central

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

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

2011-01-01

206

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

PubMed

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

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

2009-11-01

207

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

E-print Network

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.

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

2011-01-01

208

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

PubMed

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

Campbell, Matthew W; de Waal, Frans B M

2011-01-01

209

Social network analysis of Equidae movements and its application to risk-based surveillance and to control of spread of potential Equidae diseases.  

PubMed

Movements of animals and animal products are one of the most important ways of disease introduction and spread between regions and countries. Maybe one of the most complex animal species in terms of diversity of uses, nature and extent of movements are equidae, for which animal movement records are usually not available. The study presented here is the first characterization of a complete and reliable network of equidae movements in Castile and Leon, which is one of the most important equidae production regions of Spain. Social network analysis and space-time cluster analysis were used to describe the contact patterns of the equidae network and to identify the most important premises, areas and time periods for potential disease introduction or spread into the region. The studied network was complex, with very heterogeneous types of premises and diverse nature and extent of the movements compared with other livestock species, which have important implications for prevention and control of equidae diseases. Centrality measures revealed that production and reproduction farms and centres of livestock competition were the most important type of premises in the studied network. Cluster analyses allowed to identify seventeen significant spatio-temporal clusters of premises at high risk of dispatching or receiving equidae, which formed four interconnected compartments. These clusters were mainly located in the north-west region and in the second part of the year. The results of this study may be useful to design risk-based surveillance and control programmes of equidae diseases and increase the speed of detection and control of potential secondary outbreaks in future epidemics. Consequently, these results will help to minimize the great economic and sanitary impact of equidae diseases. The analytical approach used here may be easily extended to characterize the equidae movement patterns in other countries and regions of the world. PMID:22830597

Sánchez-Matamoros, A; Martínez-López, B; Sánchez-Vizcaíno, F; Sánchez-Vizcaíno, J M

2013-10-01

210

Assessing the potential spread and maintenance of foot-and-mouth disease virus infection in wild ungulates: general principles and application to a specific scenario in Thrace.  

PubMed

Foot-and-mouth disease (FMD), due to infection with serotype O virus, occurred in wild boar and within eleven outbreaks in domestic livestock in the south-east of Bulgaria, Thrace region, in 2011. Hence, the issue of the potential for the spread and maintenance of FMD virus (FMDV) infection in a population of wild ungulates became important. This assessment focused on the spread and maintenance of FMDV infection within a hypothetical wild boar and deer population in an environment, which is characterized by a climate transitional between Mediterranean and continental and variable wildlife population densities. The assessment was based on three aspects: (i) a systematic review of the literature focusing on experimental infection studies to identify the parameters describing the duration of FMDV infection in deer and wild boar, as well as observational studies assessing the occurrence of FMDV infection in wild deer and wild boar populations, (ii) prevalence survey data of wild boar and deer in Bulgaria and Turkey and (iii) an epidemiological model, simulating the host-to-host spread of FMDV infections. It is concluded, based on all three aspects, that the wildlife population in Thrace, and so wildlife populations in similar ecological settings, are probably not able to maintain FMD in the long term in the absence of FMDV infection in the domestic host population. However, limited spread of FMDV infection in time and space in the wildlife populations can occur. If there is a continued cross-over of FMDV between domestic and wildlife populations or a higher population density, virus circulation may be prolonged. PMID:24903641

Dhollander, S; Belsham, G J; Lange, M; Willgert, K; Alexandrov, T; Chondrokouki, E; Depner, K; Khomenko, S; Ozyörük, F; Salman, M; Thulke, H-H; Břtner, A

2014-06-01

211

The daily time course of contagious and spontaneous yawning among humans  

Microsoft Academic Search

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

Fiorenza Giganti; Iole Zilli

2011-01-01

212

Static network analysis of a pork supply chain in Northern Germany-Characterisation of the potential spread of infectious diseases via animal movements.  

PubMed

Transport of live animals is a major risk factor in the spread of infectious diseases between holdings. The present study analysed the pork supply chain of a producer community in Northern Germany. The structure of trade networks can be characterised by carrying out a network analysis. To identify holdings with a central position in this directed network of pig production, several parameters describing these properties were measured (in-degree, out-degree, ingoing and outgoing infection chain, betweenness centrality and ingoing and outgoing closeness centrality). To obtain the importance of the different holding types (multiplier, farrowing farms, finishing farms and farrow-to-finishing farms) within the pyramidal structure of the pork supply chain, centrality parameters were calculated for the entire network as well as for the individual holding types. Using these centrality parameters, two types of holdings could be identified. In the network studied, finishing and farrow-to-finishing farms were more likely to be infected due to the high number of ingoing trade contacts. Due to the high number of outgoing trade contacts multipliers and farrowing farms had an increased risk to spread a disease to other holdings. However, the results of the centrality parameters degree and infection chain were not always consistent, such that the indirect trade contacts should be taken into consideration to understand the real importance of a holding in spreading or contracting an infection. Furthermore, all calculated parameters showed a highly right-skewed distribution. Networks with such a degree distribution are considered to be highly resistant concerning the random removal of nodes. But by strategic removal of the most central holdings, e.g. by trade restrictions or selective vaccination or culling, the network structure can be changed efficiently and thus decompose into fragments. Such a fragmentation of the trade networks is of particular importance from an epidemiological perspective. PMID:23462679

Büttner, Kathrin; Krieter, Joachim; Traulsen, Arne; Traulsen, Imke

2013-07-01

213

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

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

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

2015-02-01

214

Johne's Disease Max Irsik DVM, MAB  

E-print Network

is a contagious chronic and usually fatal infection that affects primarily the small intestine of ruminants. Johne of leprosy and tuberculosis. All ruminants are susceptible to Johne's disease. Clinical signs are rarely

Watson, Craig A.

215

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

PubMed

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

Romero, Teresa; Konno, Akitsugu; Hasegawa, Toshikazu

2013-01-01

216

Contagious parthenogenesis, automixis, and a sex determination meltdown.  

PubMed

Because of the twofold cost of sex, genes conferring asexual reproduction are expected to spread rapidly in sexual populations. However, in reality this simple prediction is often confounded by several complications observed in natural systems. Motivated by recent findings in the Cape honey bee and in the parasitoid wasp Lysiphlebus fabarum, we explore through mathematical models the spread of a recessive, parthenogenesis inducing allele in a haplodiploid population. The focus of these models is on the intricate interactions between the mode of parthenogenesis induction through automixis and complementary sex determination (CSD) systems. These interactions may result in asexual production of diploid male offspring and the spread of the parthenogenesis-inducing allele through these males. We demonstrate that if parthenogenetic females produce a substantial proportion of male offspring, this may prevent the parthenogenesis-inducing allele from spreading. However, this effect is weakened if these diploid males are at least partially fertile. We also predict a degradation of multilocus CSD systems during the spread of parthenogenesis, following which only a single polymorphic CSD locus is maintained. Finally, based on empirical parameter estimates from L. fabarum we predict that male production in parthenogens is unlikely to prevent the eventual loss of sexual reproduction in this system. PMID:21029077

Engelstädter, Jan; Sandrock, Christoph; Vorburger, Christoph

2011-02-01

217

Are you protected against Pertussis? Pertussis, or whooping cough, is a highly contagious respiratory infection caused by the bacterium  

E-print Network

Are you protected against Pertussis? Pertussis, or whooping cough, is a highly contagious respiratory infection caused by the bacterium Bordetella pertussis. It causes severe coughing spells, vomiting

218

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

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…

DiSpezio, Michael A.

219

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

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease virus (MDV) is a cell-associated alphaherpesvirus that induces T-cell lymphomas in poultry. MDV isolates vary greatly in pathogenicity. While some are non-pathogenic and are used as vaccines, others such as RB-1B are highly oncogenic. Comparison of the genome sequences of phenotypica...

220

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

Microsoft Academic Search

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

J. P Legg

1999-01-01

221

BBC News In Depth: Foot and Mouth Disease  

NSDL National Science Digital Library

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.

2001-01-01

222

Elevated temperature and light enhance progression and spread of black band disease on staghorn corals of the Great Barrier Reef  

Microsoft Academic Search

Rates of progression and transmission of black band disease (BBD) on the staghorn coral, Acropora muricata, were compared between months for seasonal in situ studies and between temperature treatments in experimental aquaria manipulations\\u000a at Lizard Island on the Great Barrier Reef (GBR). In situ field experiments demonstrated that BBD progressed along branches\\u000a approximately twice as fast (1.7–2.4 times) during the

Holly V. Boyett; David G. Bourne; Bette L. Willis

2007-01-01

223

Contagious yawning in gelada baboons as a possible expression of empathy  

PubMed Central

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

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

2009-01-01

224

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

PubMed

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

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

2009-11-17

225

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

Microsoft Academic Search

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

Andrew C. Gallup; Gordon G. Gallup Jr

226

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

PubMed

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

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

2015-01-01

227

Characterization of Contact Structures for the Spread of Infectious Diseases in a Pork Supply Chain in Northern Germany by Dynamic Network Analysis of Yearly and Monthly Networks.  

PubMed

A major risk factor in the spread of diseases between holdings is the transport of live animals. This study analysed the animal movements of the pork supply chain of a producer group in Northern Germany. The parameters in-degree and out-degree, ingoing and outgoing infection chain, betweenness and ingoing and outgoing closeness were measured using dynamic network analysis to identify holdings with central positions in the network and to characterize the overall network topology. The potential maximum epidemic size was also estimated. All parameters were calculated for three time periods: the 3-yearly network, the yearly and the monthly networks. The yearly and the monthly networks were more fragmented than the 3-yearly network. On average, one-third of the holdings were isolated in the yearly networks and almost three quarters in the monthly networks. This represented an immense reduction in the number of holdings participating in the trade of the monthly networks. The overall network topology showed right-skewed distributions for all calculated centrality parameters indicating that network resilience was high concerning the random removal of holdings. However, for a targeted removal of holdings according to their centrality, a rapid fragmentation of the trade network could be expected. Furthermore, to capture the real importance of holdings for disease transmission, indirect trade contacts (infection chain) should be considered. In contrast to the parameters regarding direct trade contacts (degree), the infection chain parameter did not underestimate the potential risk of disease transmission. This became more obvious, the longer the observed time period was. For all three time periods, the results for the estimation of the potential maximum epidemic size illustrated that the outgoing infection chain should be chosen. It considers the chronological order and the directed nature of the contacts and has no restrictions such as the strongly connected components of a cyclic network. PMID:23692588

Büttner, K; Krieter, J; Traulsen, I

2013-05-22

228

EXPERIMENTAL CONTAGIOUS ECTHYMA IN MULE DEER, WHITE-TAILED DEER, PRONGHORN AND WAPITI1  

Microsoft Academic Search

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 (Ocis cana- densis canadensis) to determine the susceptibility and pathogenesis in these species. All four species devel- oped mucocutaneous proliferative lesions of the oral cavity, grossly

William R. Lance; Charles P. Hibler; James DeMartini

229

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

E-print Network

What is the flu? Influenza, "the flu" is a contagious respiratory infection caused by the influenza known as "swine flu") in humans causes similar symptoms to the seasonal flu but may also include. What are the symptoms? Flu symptoms start 1-4 days after exposure. Symptoms usually start suddenly

Virginia Tech

230

Catch It If You Can: How Contagious Motivation Improves Group Projects and Course Satisfaction  

ERIC Educational Resources Information Center

This article proposes a theory-based contagious motivation model focusing on enhancing student perceptions of group projects and ultimately course satisfaction. Moreover, drawing from both pedagogical and organizational behavior literatures, a model is presented that ties together intrinsic motivation theory with social contagion and…

Krishen, Anjala S.

2013-01-01

231

Contagious errors: Understanding and avoiding issues with imaging drives containing faulty sectors  

Microsoft Academic Search

When using certain tools to image drives that contain faulty sectors, the tool may fail to acquire a run of sectors even though only one of the sectors is really faulty. This phenomenon, which we have dubbed “contagious errors” was reported by James Lyle and Mark Wozar in a recent paper presented at DFRWS 2007 [Lyle, J., Wozar, M. Issues

David Byers; Nahid Shahmehri

2008-01-01

232

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

PubMed

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

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

2012-03-01

233

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

PubMed

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

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

2012-01-01

234

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

PubMed Central

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

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

2012-01-01

235

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

PubMed

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

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

2013-03-23

236

Contagious agalactia due to Mycoplasma spp. in small dairy ruminants: epidemiology and prospects for diagnosis and control.  

PubMed

Contagious agalactia (CA) is a serious disease of small dairy ruminants that has a substantial economic impact on the goat and sheep milk industries. The main aetiological agent of the disease is Mycoplasma agalactiae, although other species, such as Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens, are pathogenic in goats. There are two clinical-epidemiological states of CA in sheep and goats; herds and flocks may exhibit outbreaks of CA or may be chronically infected, the latter with a high incidence of subclinical mastitis and only occasional clinical cases. The complex epidemiology of CA is related to the genetic characteristics and mechanisms of molecular variation of the Mycoplasma spp. involved, along with presence of CA-mycoplasmas in wild ruminant species. In goats, the situation is particularly complex and asymptomatic carriers have been detected in chronically infected herds. The coexistence of other non-pathogenic mycoplasmas in the herd further complicates the diagnosis of CA and the design of efficient strategies to control the disease. Routes of infection, such as the venereal route, may be involved in the establishment of chronic infection in herds. Current challenges include the need for improved diagnostic methods for detection of chronic and subclinical infections and for the design of more efficient vaccines. PMID:23759248

Gómez-Martín, Angel; Amores, Joaquín; Paterna, Ana; De la Fe, Christian

2013-10-01

237

Mathematical Modelling of the Transmission Dynamics of Contagious Bovine Pleuropneumonia Reveals Minimal Target Profiles for Improved Vaccines and Diagnostic Assays  

PubMed Central

Contagious bovine pleuropneumonia (CBPP) is a cattle disease that has hampered the development of the livestock sector in sub-Saharan Africa. Currently, vaccination with a live vaccine strain is its recommended control measure although unofficial antimicrobial use is widely practiced. Here, modelling techniques are used to assess the potential impact of early elimination of infected cattle via accurate diagnosis on CBPP dynamics. A herd-level stochastic epidemiological model explicitly incorporating test sensitivity and specificity is developed. Interventions by annual vaccination, annual testing and elimination and a combination of both are implemented in a stepwise manner and their effectiveness compared by running 1000 simulations per intervention over ten years. The model predicts that among the simulated interventions, the ones likely to eliminate the disease from an isolated herd all involved annual vaccination of more than 75% of the animals with a vaccine that protects for at least 18 months combined with annual testing (and elimination of positive reactors) of 75% of the animals every six months after vaccination. The highest probability of disease elimination was 97.5% and this could occur within a median of 2.3 years. Generally, our model predicts that regular testing and elimination of positive reactors using improved tests will play a significant role in minimizing CBPP burden especially in the current situation where improved vaccines are yet to be developed. PMID:25668725

Ssematimba, Amos; Jores, Joerg; Mariner, Jeffrey C.

2015-01-01

238

Lesion of the subiculum reduces the spread of amyloid beta pathology to interconnected brain regions in a mouse model of Alzheimer’s disease  

PubMed Central

Background The progressive development of Alzheimer’s disease (AD) pathology follows a spatiotemporal pattern in the human brain. In a transgenic (Tg) mouse model of AD expressing amyloid precursor protein (APP) with the arctic (E693G) mutation, pathology spreads along anatomically connected structures. Amyloid-? (A?) pathology first appears in the subiculum and is later detected in interconnected brain regions, including the retrosplenial cortex. We investigated whether the spatiotemporal pattern of A? pathology in the Tg APP arctic mice to interconnected brain structures can be interrupted by destroying neurons using a neurotoxin and thereby disconnecting the neural circuitry. Results We performed partial unilateral ibotenic acid lesions of the subiculum (first structure affected by A? pathology) in young Tg APParc mice, prior to the onset of pathology. We assessed A?/C99 pathology in mice aged up to 6 months after injecting ibotenate into the subiculum. Compared to the brains of intact Tg APP arctic mice, we observed significantly decreased A?/C99 pathology in the ipsilateral dorsal subiculum, CA1 region of the hippocampus and the retrosplenial cortex; regions connecting to and from the dorsal subiculum. By contrast, A?/C99 pathology was unchanged in the contralateral hippocampus in the mice with lesions. Conclusion These results, obtained in an animal model of AD, support the notion that A?/C99 pathology is transmitted between interconnected neurons in AD. PMID:24517102

2014-01-01

239

Parallelization: Infectious Disease  

NSDL National Science Digital Library

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.

Aaron Weeden

240

Infectious Diseases in Day Care.  

ERIC Educational Resources Information Center

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,…

Sleator, Esther K.

241

Foot-and-mouth disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. An outbreak of FMD can have a significant economic impact because of the restrictions on international trade of susceptible animals and their products with FMD-free countries. In this chapter we discuss vario...

242

Shelf life of wet T 1 broth vaccine for contagious bovine pleuropneumonia  

Microsoft Academic Search

Monthly viable counts and pH monitoring of several batches of wet contagious bovine pleuropneumonia broth vaccine preserved at 4°C were done. The viable counts of all the batches did not drop below 107 cfu\\/ml until after 4 months. The pH of the broth vaccine also stayed at approximately 7.55 for a period of 11 months. The investigation showed that the

Samuel A. Garba

1980-01-01

243

Spatial contagiousness of canopy disturbance in tropical rain forest: An individual - tree-based test  

Microsoft Academic Search

Spatial contagiousness of canopy dynamicsżthe tendency of canopy disturbances to occur nearby existing canopy openings due to an elevated risk of tree fall around gapsżhas been demonstrated in many temperate-zone forests, but only inferentially for tropical forests. Hypothesized mechanisms increasing the risk of tree fall around tropical forest gaps are (1) increased tree exposure to wind around gaps, (2) reduced

Patrick A. Jansen; Meer van der P. J; Frans Bongers

2008-01-01

244

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

PubMed

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

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

2012-07-01

245

Evolutionary history of contagious bovine pleuropneumonia using next generation sequencing of Mycoplasma mycoides Subsp. mycoides "Small Colony".  

PubMed

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 19(th) century through the cattle trade and was eradicated from most continents by stamping-out policies. During the 20(th) 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 19(th) 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

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

246

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

PubMed

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

Gjurasi?, Marija

2010-01-01

247

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

PubMed

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

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

2007-03-01

248

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

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

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

2010-12-01

249

An international collaborative study to determine the prevalence of contagious caprine pleuropneumonia by monoclonal antibody-based cELISA  

PubMed Central

Background Few serological tests are available for detecting antibodies against Mycoplasma capricolum subsp. capripneumoniae, the causal agent of contagious caprine pleuropneumonia (CCPP). The complement fixation test, the test prescribed for international trade purposes, uses a crude antigen that cross-reacts with all the other mycoplasma species of the “mycoides cluster” frequently infecting goat herds. The lack of a more specific test has been a real obstacle to the evaluation of the prevalence and economic impact of CCPP worldwide. A new competitive ELISA kit for CCPP, based on a previous blocking ELISA, was formatted at CIRAD and used to evaluate the prevalence of CCPP in some regions of Kenya, Ethiopia, Mauritius, Tajikistan and Pakistan in an international collaborative study. Results The strict specificity of the test was confirmed in CCPP-free goat herds exposed to other mycoplasma species of the “mycoides cluster”. Prevalence studies were performed across the enzootic range of the disease in Africa and Asia. Seroprevalence was estimated at 14.6% in the Afar region of Ethiopia, whereas all the herds presented for CCPP vaccination in Kenya tested positive (individual seroprevalence varied from 6 to 90% within each herd). In Mauritius, where CCPP emerged in 2009, nine of 62 herds tested positive. In Central Asia, where the disease was confirmed only recently, no positive animals were detected in the Wakhan District of Afghanistan or across the border in neighboring areas of Tajikistan, whereas seroprevalence varied between 2.7% and 44.2% in the other districts investigated and in northern Pakistan. The test was also used to monitor seroconversion in vaccinated animals. Conclusions This newly formatted CCPP cELISA kit has retained the high specificity of the original kit. It can therefore be used to evaluate the prevalence of CCPP in countries or regions without vaccination programs. It could also be used to monitor the efficacy of vaccination campaigns as high-quality vaccines induce high rates of seroconversion. PMID:24565080

2014-01-01

250

Willingness to pay for contagious bovine pleuropneumonia vaccination in Narok South District of Kenya  

PubMed Central

Contagious bovine pleuropneumonia (CBPP) is an economically important trans-boundary cattle disease which affects food security and livelihoods. A conjoint analysis–contingent valuation was carried out on 190 households in Narok South District of Kenya to measure willingness to pay (WTP) and demand for CBPP vaccine and vaccination as well as factors affecting WTP. The mean WTP was calculated at Kenya Shillings (KSh) 212.48 (USD 3.03) for vaccination using a vaccine with the characteristics that were preferred by the farmers (preferred vaccine and vaccination) and KSh ?71.45 (USD ?1.02) for the currently used vaccine and vaccination. The proportion of farmers willing to pay an amount greater than zero was 66.7% and 34.4% for the preferred and current vaccine and vaccination respectively. About one third (33.3%) of farmers would need to be compensated an average amount of KSh 1162.62 (USD 13.68) per animal to allow their cattle to be vaccinated against CBPP using the preferred vaccine and vaccination. About two-thirds (65.6%) of farmers would need to be compensated an average amount of KSh 853.72 (USD 12.20) per animal to allow their cattle to be vaccinated against CBPP using the current vaccine and vaccination. The total amount of compensation would be KSh 61.39 million (USD 0.88 million) for the preferred vaccine and vaccination and KSh 90.15 million (USD 1.29 million) for the current vaccine and vaccination. Demand curves drawn from individual WTP demonstrated that only 59% and 27% of cattle owners with a WTP greater than zero were willing to pay a benchmark cost of KSh 34.60 for the preferred and current vaccine respectively. WTP was negatively influenced by the attitude about household economic situation (p = 0.0078), presence of cross breeds in the herd (p < 0.0001) and years since CBPP had been experienced in the herd (p = 0.0375). It was positively influenced by education (p = 0.0251) and the practice of treating against CBPP (p = 0.0432). The benefit cost ratio (BCR) for CBPP vaccination was 2.9–6.1 depending on the vaccination programme. In conclusion, although a proportion of farmers was willing to pay, participation levels may be lower than those required to interrupt transmission of CBPP. Households with characteristics that influence WTP negatively need persuasion to participate in CBPP vaccination. It is economically worthwhile to vaccinate against CBPP. A benefit cost analysis (BCA) using aggregated WTP as benefits can be used as an alternative method to the traditional BCA which uses avoided production losses (new revenue) and costs saved as benefits. PMID:24774477

Kairu-Wanyoike, Salome W.; Kaitibie, Simeon; Heffernan, Claire; Taylor, Nick M.; Gitau, George K.; Kiara, Henry; McKeever, Declan

2014-01-01

251

Genetic diversity and mutation of avian paramyxovirus serotype 1 (Newcastle disease 2 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...

252

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

PubMed

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

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

2013-03-01

253

Low major histocompatibility complex diversity in the Tasmanian devil predates European settlement and may explain susceptibility to disease epidemics  

PubMed Central

The Tasmanian devil (Sarcophilus harrisii) is at risk of extinction owing to the emergence of a contagious cancer known as devil facial tumour disease (DFTD). The emergence and spread of DFTD has been linked to low genetic diversity in the major histocompatibility complex (MHC). We examined MHC diversity in historical and ancient devils to determine whether loss of diversity is recent or predates European settlement in Australia. Our results reveal no additional diversity in historical Tasmanian samples. Mainland devils had common modern variants plus six new variants that are highly similar to existing alleles. We conclude that low MHC diversity has been a feature of devil populations since at least the Mid-Holocene and could explain their tumultuous history of population crashes. PMID:23221872

Morris, Katrina; Austin, Jeremy J.; Belov, Katherine

2013-01-01

254

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

ERIC Educational Resources Information Center

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…

White, Michael D.; Klinger, David

2012-01-01

255

Host-induced epidemic spread of the cholera bacterium  

Microsoft Academic Search

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

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

256

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

PubMed Central

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

2014-01-01

257

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

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

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

2015-01-01

258

Characteristics of cyprinid herpesvirus 3 in different phases of infection: implications for disease transmission and control.  

PubMed

Koi herpesvirus disease (KHVD) is an emerging and highly contagious viral disease of koi and common carp (Cyprinus carpio), causing mass mortalities and huge economic losses to the carp aquaculture industry. The disease has spread rapidly to 28 countries worldwide. However, mechanisms of koi herpesvirus (species Cyprinid herpesvirus 3; CyHV-3) transmission remain unclear. A potential experimental model of CyHV-3 infection in carp was used to characterise CyHV-3 in different phases of infection and to demonstrate that CyHV-3 persists in survivor fish and has the capacity to reactivate and transmit the disease to healthy fish. During acute infection, which occurred when fish were maintained at 22°C, viral genes were abundantly expressed and infectious virus was produced in association with tissue damage, clinical disease and mortality. In fish maintained at a lower temperature (11°C), viral DNA was present but viral gene expression was absent or greatly restricted, infectious virus was not recovered and there was no evidence of disease. Productive replication was re-initiated following an increase in water temperature to 22°C, resulting in 45% mortality. Shedding of reactivated virus killed 75% of cohabitating naďve fish, suggesting a potential risk for disease transmission. PMID:24704574

Sunarto, Agus; McColl, Kenneth A; Crane, Mark St J; Schat, Karel A; Slobedman, Barry; Barnes, Andrew C; Walker, Peter J

2014-08-01

259

NOVEL TOOLS TO PREVENT AND ERADICATE FOREIGN ANIMAL DISEASES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foreign and emerging animal diseases such as Foot-and-Mouth Disease (FMD) and Classical Swine Fever (CSF) can have devastating social and economical effects and represent important threats to US agriculture and food supply. FMD and CSF are highly contagious viral diseases of livestock. Reemergence ...

260

Foot-and-mouth disease: global status and Indian perspective  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) is a highly contagious and transboundary viral disease of domesticated and wild cloven-hoofed animals. Wide prevalence of the disease in Asia and Africa associated with huge economic loss to the livestock farming and industry has increased the concern worldwide. The di...

261

Immunological Basis for Resistance and Susceptibility to Marek's Disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease (MD) is a contagious lymphoproliferative disease of domestic chickens caused by a highly cell-associated alpha-herpesvirus, Marek’s disease virus (MDV). MDV replicates in chicken lymphocytes and establishes a latent infection within CD4+ T cells. Mechanisms of viral pathogenesis, r...

262

How the contagion at links influences epidemic spreading  

NASA Astrophysics Data System (ADS)

The reaction-diffusion (RD) model of epidemic spreading generally assume that contagion occurs only at the nodes of network, i.e., the links are used only for migration/diffusion of agents. However, in reality, we observe that contagion occurs also among the travelers staying in the same car, train or plane etc., which consist of the links of network. To reflect the contagious effect of links, we here present a traveling-contagion model where contagion occurs not only at nodes but also at links. Considering that the population density in transportation is generally much larger than that in districts, we introduce different infection rates for the nodes and links, respectively, whose two extreme cases correspond to the type-I and type-II reactions in the RD model [V. Colizza, R. Pastor-Satorras, A. Vespignani, Nat. Phys. 3, 276 (2007)]. Through studying three typical diffusion processes, we reveal both numerically and theoretically that the contagion at links can accelerate significantly the epidemic spreading. This finding is helpful in designing the controlling strategies of epidemic spreading.

Ruan, Zhongyuan; Tang, Ming; Liu, Zonghua

2013-04-01

263

A virulent bioluminescent and fluorescent dual-reporter Marek's disease virus unveils an alternative spreading pathway in addition to cell-to-cell contact.  

PubMed

Marek's disease virus (MDV) is a growing threat for the poultry industry. Unfortunately, despite successful vaccination against the disease, MDV remains in circulation within vaccinated flocks, leading to the selection of increasingly virulent pathotypes. Detailed knowledge of the virus biology and the host-virus interaction is required to improve the vaccine efficiency. In the present study, I engineered an original, dual-reporter MDV to track and quantify virus replication in vitro and in vivo. PMID:25031355

Harmache, Abdallah

2014-10-01

264

Characterization of Anamnestic T-cell Responses Induced by Conventional Vaccines against Contagious Bovine Pleuropneumonia  

PubMed Central

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

Totte, Philippe; Yaya, Aboubakar; Sery, Amadou; Wesonga, Hezron; Wade, Abel; Naessens, Jan; Niang, Mamadou; Thiaucourt, François

2013-01-01

265

Characterization of anamnestic T-cell responses induced by conventional vaccines against contagious bovine pleuropneumonia.  

PubMed

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

Totte, Philippe; Yaya, Aboubakar; Sery, Amadou; Wesonga, Hezron; Wade, Abel; Naessens, Jan; Niang, Mamadou; Thiaucourt, François

2013-01-01

266

Contagious error sources would need time travel to prevent quantum computation  

E-print Network

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.

Gil Kalai; Greg Kuperberg

2014-12-05

267

Language-Spread Policy.  

ERIC Educational Resources Information Center

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…

Ammon, Ulrich

1997-01-01

268

Flame spread across liquids  

NASA Technical Reports Server (NTRS)

Recent reviews of our understanding of flame spread across liquids show that there are many unresolved issues regarding the phenomenology and causal mechanisms affecting ignition susceptibility, flame spread characteristics, and flame spread rates. One area of discrepancy is the effect of buoyancy in both the uniform and pulsating spread regimes. The approach we have taken to resolving the importance of buoyancy for these flames is: (1) normal gravity (1g) and microgravity (micro g) experiments; and (2) numerical modeling at different gravitational levels. Of special interest to this work, as discussed at the previous workshop, is the determination of whether, and under what conditions, pulsating spread occurs in micro g. Microgravity offers a unique ability to modify and control the gas-phase flow pattern by utilizing a forced air flow over the pool surface.

Ross, Howard D.; Miller, Fletcher; Schiller, David; Sirignano, William

1995-01-01

269

ISPM, Division of Biostatistics Modelling power-law spread  

E-print Network

ISPM, Division of Biostatistics Modelling power-law spread of infectious diseases Sebastian Meyer 2013 Page 1 #12;ISPM, Division of Biostatistics Epidemic Modelling ­ Prospective surveillance: outbreak-law spread of infectious diseases Page 2 #12;ISPM, Division of Biostatistics Mobility networks determine

Zurich, University of

270

One-Health Simulation Modelling: A Case Study of Influenza Spread between Human and Swine Populations using NAADSM.  

PubMed

The circulation of zoonotic influenza A viruses including pH1N1 2009 and H5N1 continue to present a constant threat to animal and human populations. Recently, an H3N2 variant spread from pigs to humans and between humans in limited numbers. Accordingly, this research investigated a range of scenarios of the transmission dynamics of pH1N1 2009 virus at the swine-human interface while accounting for different percentages of swine workers initially immune. Furthermore, the feasibility of using NAADSM (North American Animal Disease Spread Model) applied as a one-health simulation model was assessed. The study population included 488 swine herds and 29, 707 households of people within a county in Ontario, Canada. Households were categorized as follows: (i) rural households with swine workers, (ii) rural households without swine workers, and (iii) urban households without swine workers. Forty-eight scenarios were investigated, based on the combination of six scenarios around the transmissibility of the virus at the interface and four vaccination coverage levels of swine workers (0-60%), all under two settings of either swine or human origin of the virus. Outcomes were assessed in terms of stochastic 'die-out' fraction, size and time to peak epidemic day, overall size and duration of the outbreaks. The modelled outcomes indicated that minimizing influenza transmissibility at the interface and targeted vaccination of swine workers had significant beneficial effects. Our results indicate that NAADSM can be used as a framework to model the spread and control of contagious zoonotic diseases among animal and human populations, under certain simplifying assumptions. Further evaluation of the model is required. In addition to these specific findings, this study serves as a benchmark that can provide useful input to a future one-health influenza modelling studies. Some pertinent information gaps were also identified. Enhanced surveillance and the collection of high-quality information for more accurate parameterization of such models are encouraged. PMID:24661802

Dorjee, S; Revie, C W; Poljak, Z; McNab, W B; Sanchez, J

2014-03-24

271

Topology dependent epidemic spreading velocity in weighted networks  

NASA Astrophysics Data System (ADS)

Many diffusive processes occur on structured networks with weighted links, such as disease spread by airplane transport or information diffusion in social networks or blogs. Understanding the impact of weight-connectivity correlations on epidemic spreading in weighted networks is crucial to support decision-making on disease control and other diffusive processes. However, a real understanding of epidemic spreading velocity in weighted networks is still lacking. Here we conduct a numerical study of the velocity of a Reed–Frost epidemic spreading process in various weighted network topologies as a function of the correlations between edge weights and node degrees. We find that a positive weight-connectivity correlation leads to a faster epidemic spreading compared to an unweighted network. In contrast, we find that both uncorrelated and negatively correlated weight distributions lead to slower spreading processes. In the case of positive weight-connectivity correlations, the acceleration of spreading velocity is weak when the heterogeneity of weight distribution increases.

Duan, Wei; Quax, Rick; Lees, Michael; Qiu, Xiaogang; Sloot, Peter M. A.

2014-12-01

272

Mutant copper-zinc superoxide dismutase (SOD1) induces protein secretion pathway alterations and exosome release in astrocytes: implications for disease spreading and motor neuron pathology in amyotrophic lateral sclerosis.  

PubMed

Amyotrophic lateral sclerosis is the most common motor neuron disease and is still incurable. The mechanisms leading to the selective motor neuron vulnerability are still not known. The interplay between motor neurons and astrocytes is crucial in the outcome of the disease. We show that mutant copper-zinc superoxide dismutase (SOD1) overexpression in primary astrocyte cultures is associated with decreased levels of proteins involved in secretory pathways. This is linked to a general reduction of total secreted proteins, except for specific enrichment in a number of proteins in the media, such as mutant SOD1 and valosin-containing protein (VCP)/p97. Because there was also an increase in exosome release, we can deduce that astrocytes expressing mutant SOD1 activate unconventional secretory pathways, possibly as a protective mechanism. This may help limit the formation of intracellular aggregates and overcome mutant SOD1 toxicity. We also found that astrocyte-derived exosomes efficiently transfer mutant SOD1 to spinal neurons and induce selective motor neuron death. We conclude that the expression of mutant SOD1 has a substantial impact on astrocyte protein secretion pathways, contributing to motor neuron pathology and disease spread. PMID:23592792

Basso, Manuela; Pozzi, Silvia; Tortarolo, Massimo; Fiordaliso, Fabio; Bisighini, Cinzia; Pasetto, Laura; Spaltro, Gabriella; Lidonnici, Dario; Gensano, Francesco; Battaglia, Elisa; Bendotti, Caterina; Bonetto, Valentina

2013-05-31

273

Kinetics of virus spread and changes in levels of several cytokine mRNAs in the brain after intranasal infection of rats with Borna disease virus.  

PubMed Central

We have used the reverse transcriptase-polymerase chain reaction technique to gain insight into the pathogenesis of encephalitis caused by Borna disease virus (BDV). RNA specific for BDV was first detected in the olfactory bulb of intranasally infected rats at 6 days postinfection (p.i.). At 14 days p.i., high levels of BDV RNA were found in all brain regions, and at 26 days p.i., BDV-specific RNA was also present in the eye, nasal mucosa, and facial skin. In the chronic phase of the disease, BDV RNA was identified in many peripheral organs but not in blood. Analysis of brain tissue for the presence of cytokine mRNAs revealed that the mRNA levels of interleukin-6 (IL-6), tumor necrosis factor alpha, and IL-1 alpha had increased sharply at 14 and 26 days p.i. These cytokine mRNAs reached maximum levels at the peak of inflammatory reactions and decreased drastically in the chronic phase of the disease. Although IL-2 mRNA was also found in normal brain, it was markedly increased in BDV-infected brain at 14 days p.i. Expression of gamma interferon (IFN-gamma) mRNA, which was not observed in normal rat brain, was detected at 14 days p.i. and reached a maximum level at 38 days p.i. IL-2 and IFN-gamma mRNA expression correlated with expression of CD4 and CD8 mRNAs, indicating that both CD4+ and CD8+ T lymphocytes are induced in the early stages of BDV infection. Since IFN-gamma and CD8 mRNA levels were still highly elevated in the chronic phase of Borna disease, it is likely that CD8+ T lymphocytes act to reduce inflammation and to ameliorate neurological signs during the chronic phase of infection. Images PMID:1731117

Shankar, V; Kao, M; Hamir, A N; Sheng, H; Koprowski, H; Dietzschold, B

1992-01-01

274

The Relationship Between Increasing Sea-surface Temperature and the Northward Spread of Perkinsus marinus(Dermo) Disease Epizootics in Oysters  

NASA Astrophysics Data System (ADS)

From its initial discovery in the Gulf of Mexico in the late 1940s until 1990, Perkinsus marinus, the parasite responsible for Dermo disease in the eastern oyster, Crassostrea virginica, was rarely found north of Chesapeake Bay. In 1990-92, an apparent range extension of the parasite led to epizootic outbreaks of the disease over a 500 km range north of Chesapeake Bay. One of the hypotheses for the range extension argues that small, undetected numbers of parasites were already present in northern oysters as the result of repeated historical introductions, and that a sharp warming trend in 1990-92 stimulated the disease outbreak. This argument was based on trends in air temperature. The present study examined this hypothesis by analysing water temperatures, rather than air temperatures, for five stations located in areas affected by the recent epizootics. At all five stations, there was a strong increasing trend in winter sea-surface temperature (SST) between 1986 and 1991. At four of the five stations, there was a smaller increasing trend in winter temperatures after 1960. There were no consistent or obvious trends in summer (August) temperatures. In Delaware Bay, which has a 40 year history of monitoring for oyster diseases, occasional findings of P. marinusin oysters were correlated with warming episodes that were especially notable in the winter (February) record. Empirical orthogonal function (EOF) analysis showed that winter temperatures varied consistently at the stations examined and were associated with variations in P. marinusprevalence. Associations using EOF analysis with August temperatures were much weaker. The SST record is consistent with the hypothesis that increasing winter water temperatures have been important in the recent outbreak of P. marinusepizootics in the north-eastern U.S.A.

Cook, T.; Folli, M.; Klinck, J.; Ford, S.; Miller, J.

1998-04-01

275

Sea Floor Spreading I  

NSDL National Science Digital Library

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.

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

276

High antibody titres against predicted Mycoplasma surface proteins do not prevent sequestration in infected lung tissue in the course of experimental contagious bovine pleuropneumonia.  

PubMed

Contagious bovine pleuropneumonia (CBPP), a severe respiratory disease of cattle caused by Mycoplasma mycoides subsp. mycoides (Mmm) is endemic in many African countries due to fragmented veterinary services and the lack of an efficient vaccine and sensitive diagnostics. More efficient tools to control the disease are needed, but to develop the tools, a better understanding of host-pathogen interactions is necessary. The aim of this study was to characterize the kinetics of the humoral immune response against 65 Mmm surface antigens for an extended period in cattle that survived a primary infection with Mmm. We describe clinical and haematological outcomes, and dissect the humoral immune response over time, to specific antigens and compared the antibody responses between different pathomorphological outcomes. No antigen-specific antibodies correlating with protection were identified. Interestingly we found that animals that developed Mycoplasma-containing sequestra had significantly higher antibody levels against proteins comprising the surface proteome than the animals that cleared Mycoplasma from their lungs. Based on these data we suggest that high antibody titres might play a role in the establishment of pathomorphological changes, such as vasculitis, which should be investigated in future studies. Beneficial antibody specificities and cellular immune responses need to be identified in order to foster the development of an improved vaccine in the future. PMID:24880898

Schieck, Elise; Liljander, Anne; Hamsten, Carl; Gicheru, Nimmo; Scacchia, Massimo; Sacchini, Flavio; Heller, Martin; Schnee, Christiane; Sterner-Kock, Anja; Hlinak, Andreas; Naessens, Jan; Poole, Jane; Persson, Anja; Jores, Joerg

2014-08-01

277

Spreading of Cholera through Surface Water  

NASA Astrophysics Data System (ADS)

Cholera epidemics are still a major public health concern to date in many areas of the world. In order to understand and forecast cholera outbreaks, one of the most important factors is the role played by the environmental matrix in which the disease spreads. We study how river networks, acting as environmental corridors for pathogens, affect the spreading of cholera epidemics. The environmental matrix in which the disease spreads is constituted by different human communities and their hydrologic interconnections. Each community is characterized by its spatial position, population size, water resources availability and hygiene conditions. By implementing a spatially explicit cholera model we seek the effects on epidemic dynamics of: i) the topology and metrics of the pathogens pathways that connect different communities; ii) the spatial distribution of the population size; and iii) the spatial distributions and quality of surface water resources and public health conditions, and how they vary with population size. The model has been applied to study the space-time evolution of a well documented cholera epidemic occurred in the KwaZulu-Natal province of South Africa. The epidemic lasted for two years and involved about 140,000 confirmed cholera cases. The model does well in reproducing the distribution of the cholera cases during the two outbreaks as well as their spatial spreading. We further extend the model by deriving the speed of propagation of traveling fronts in the case of uniformly distributed systems for different topologies: one and two dimensional lattices and river networks. The derivation of the spreading celerity proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. The conditions are sought by comparison between spreading and disease timescales. Consider a cholera epidemic that starts from a point and spreads throughout a finite size system, it is possible to identify two different timescales: i) the spreading timescale, that is the time needed for the disease to spread and involve all the communities in the system; and ii) the epidemic timescale, defined by the duration of the epidemic in a single community. Our results suggest that in many cases of real-life epidemiological interest, timescales of disease dynamics may trigger outbreaks that significantly depart from the predictions of classical space-implicit compartmental models.

Bertuzzo, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

2009-12-01

278

Familiarity-connected or stress-based contagious yawning in domestic dogs (Canis familiaris)? Some additional data.  

PubMed

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

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

2013-11-01

279

Epidemic Spread on Weighted Networks  

PubMed Central

The contact structure between hosts shapes disease spread. Most network-based models used in epidemiology tend to ignore heterogeneity in the weighting of contacts between two individuals. However, this assumption is known to be at odds with the data for many networks (e.g. sexual contact networks) and to have a critical influence on epidemics' behavior. One of the reasons why models usually ignore heterogeneity in transmission is that we currently lack tools to analyze weighted networks, such that most studies rely on numerical simulations. Here, we present a novel framework to estimate key epidemiological variables, such as the rate of early epidemic expansion () and the basic reproductive ratio (), from joint probability distributions of number of partners (contacts) and number of interaction events through which contacts are weighted. These distributions are much easier to infer than the exact shape of the network, which makes the approach widely applicable. The framework also allows for a derivation of the full time course of epidemic prevalence and contact behaviour, which we validate with numerical simulations on networks. Overall, incorporating more realistic contact networks into epidemiological models can improve our understanding of the emergence and spread of infectious diseases. PMID:24348225

Kamp, Christel; Moslonka-Lefebvre, Mathieu; Alizon, Samuel

2013-01-01

280

Genome-wide identification of host genes directly regulated by Marek’s disease virus (MDV) oncoprotein Meq  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek's disease (MD) is a contagious lymphoproliferative and neurotropic disease of poultry caused by Marek's disease virus (MDV), an oncogenic alphaherpesvirus. Despite the use of vaccines, the field strains of MDV continue to evolve, resulting in unpredictable disease outbreaks. Therefore, underst...

281

Contagious yawning, social cognition, and arousal: an investigation of the processes underlying shelter dogs' responses to human yawns.  

PubMed

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

Buttner, Alicia Phillips; Strasser, Rosemary

2014-01-01

282

Contagious Comments: What Was the Online Buzz About the 2011 Quebec Measles Outbreak?  

PubMed Central

Background Although interruption of endemic measles was achieved in the Americas in 2002, Quebec experienced an outbreak in 2011 of 776 reported cases; 80% of these individuals had not been fully vaccinated. We analyzed readers’ online responses to Canadian news articles regarding the outbreak to better understand public perceptions of measles and vaccination. Methods We searched Canadian online English and French news sites for articles posted between April 2011 and March 2012 containing the words “measles” and “Quebec”. We included articles that i) concerned the outbreak or related vaccination strategies; and ii) generated at least ten comments. Two English and two bilingual researchers coded the unedited comments, categorizing codes to allow themes to emerge. Results We analyzed 448 comments from 188 individuals, in response to three French articles and six English articles; 112 individuals expressed positive perceptions of measles vaccination (2.2 comments/person), 38 were negative (4.2 comments/person), 11 had mixed feelings (1.5 comments/person), and 27 expressed no opinion (1.1 comments/person). Vaccine-supportive themes involved the success of vaccination in preventing disease spread, societal responsibility to vaccinate for herd immunity, and refutation of the autism link. Those against measles vaccination felt it was a personal rather than societal choice, and conveyed a distrust of vaccine manufacturers, believing that measles infection is not only safe but safer than vaccination. Commenters with mixed feelings expressed uncertainty of the infection’s severity, and varied in support of all vaccines based on perceived risk/benefit ratios. Conclusion The anti-vaccine minority’s volume of comments translates to a disproportionately high representation on online boards. Public health messages should address concerns by emphasizing that immunization is always a personal choice in Canada, and that the pharmaceutical industry is strictly controlled. Illustrating the dangers of measles through personal stories, rather than scientific data only, may also serve to strengthen messaging. PMID:23691152

Pereira, Jennifer A.; Quach, Susan; Dao, Huy Hao; Kwong, Jeffrey C.; Deeks, Shelley L.; Crowcroft, Natasha S.; Quan, Sherman D.; Guay, Maryse

2013-01-01

283

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

PubMed Central

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

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

2013-01-01

284

Horizontal Gene Transfers Link a Human MRSA Pathogen to Contagious Bovine Mastitis Bacteria  

PubMed Central

Background Acquisition of virulence factors and antibiotic resistance by many clinically important bacteria can be traced to horizontal gene transfer (HGT) between related or evolutionarily distant microflora. Comparative genomic analysis has become an important tool for identifying HGT DNA in emerging pathogens. We have adapted the multi-genome alignment tool EvoPrinter to facilitate discovery of HGT DNA sequences within bacterial genomes and within their mobile genetic elements. Principal Findings EvoPrinter analysis of 13 different Staphylococcus aureus genomes revealed that one of the human isolates, the hospital epidemic methicillin-resistant MRSA252 strain, uniquely shares multiple putative HGT DNA sequences with different causative agents of bovine mastitis that are not found in the other human S. aureus isolates. MRSA252 shares over 14 different DNA sequence blocks with the bovine mastitis ET3 S. aureus strain RF122, and many of the HGT DNAs encode virulence factors. EvoPrinter analysis of the MRSA252 chromosome also uncovered virulence-factor encoding HGT events with the genome of Listeria monocytogenes and a Staphylococcus saprophyticus associated plasmid. Both bacteria are also causal agents of contagious bovine mastitis. Conclusions EvoPrinter analysis reveals that the human MRSA252 strain uniquely shares multiple DNA sequence blocks with different causative agents of bovine mastitis, suggesting that HGT events may be occurring between these pathogens. These findings have important implications with regard to animal husbandry practices that inadvertently enhance the contact of human and livestock bacterial pathogens. PMID:18728754

Brody, Thomas; Yavatkar, Amarendra S.; Lin, Yong; Ross, Jermaine; Kuzin, Alexander; Kundu, Mukta; Fann, Yang; Odenwald, Ward F.

2008-01-01

285

Contagious bovine pleuropneumonia vaccines: the current situation and the need for improvement.  

PubMed

The control of contagious bovine pleuropneumonia (CBPP) has been clearly identified by the Organisation of African Unity/Inter-African Bureau of Animal Resources as a priority. In the first part of this article, the authors introduce the past and present vaccines, based on the two classic strains, T1, and KH3J. They describe the guidelines for vaccine production technology, and the quality control requirements for CBPP vaccines of the Office International des Epizooties. The failure of the currently used T1-SR vaccine to provoke satisfactory immunity in cattle, particularly in the newly infected areas of Africa, is pointed out. Other shortcomings of the current CBPP vaccines are also highlighted. Thus, there is a need to improve CBPP vaccines and the authors propose detailed emergency measures to address this problem. In the second part of the article, a subunit approach using immunostimulating complex technology is outlined. The authors emphasise the importance of current research in cell-mediated immunity and immunopathology, which is aimed at improving the efficacy of CBPP vaccines. PMID:9190019

Tulasne, J J; Litamoi, J K; Morein, B; Dedieu, L; Palya, V J; Yami, M; Abusugra, I; Sylla, D; Bensaid, A

1996-12-01

286

Newcastle Disease: Progress and gaps in the development of vaccines and diagnostic tools  

Technology Transfer Automated Retrieval System (TEKTRAN)

Newcastle disease (ND) is a contagious disease of birds that can have severe economic consequences for any poultry producer, including a serious impact on the international trade of poultry and eggs. Newcastle disease virus (NDV) isolates are also called avian paramyxovirus serotype-1 isolates, but ...

287

Outbreaks where food workers have been implicated in the spread of foodborne disease. Part 1. Description of the problem, methods, and agents involved.  

PubMed

Food workers in many settings have been responsible for foodborne disease outbreaks for decades, and there is no indication that this is diminishing. The Committee on Control of Foodborne Illnesses of the International Association for Food Protection was tasked with collecting and evaluating any data on worker-associated outbreaks. A total of 816 reports with 80,682 cases were collected from events that occurred from 1927 until the first quarter of 2006. Most of the outbreaks reviewed were from the United States, Canada, Europe, and Australia, with relatively few from other parts of the world, indicating the skewed set of data because of availability in the literature or personal contact. Outbreaks were caused by 14 agents: norovirus or probable norovirus (338), Salmonella enterica (151), hepatitis A virus (84), Staphylococcus aureus (53), Shigella spp. (33), Streptococcus Lancefield groups A and G (17), and parasites Cyclospora, Giardia, and Cryptosporidium (23). Streptococcal, staphylococcal, and typhoid outbreaks seem to be diminishing over time; hepatitis A virus remains static, whereas norovirus and maybe nontyphoidal Salmonella are increasing. Multiple foods and multi-ingredient foods were identified most frequently with outbreaks, perhaps because of more frequent hand contact during preparation and serving. PMID:17685355

Greig, Judy D; Todd, Ewen C D; Bartleson, Charles A; Michaels, Barry S

2007-07-01

288

Outbreaks where food workers have been implicated in the spread of foodborne disease. Part 5. Sources of contamination and pathogen excretion from infected persons.  

PubMed

In this article, the fifth in a series reviewing the role of food workers in foodborne outbreaks, background information on the routes of infection for food workers is considered. Contamination most frequently occurs via the fecal-oral route, when pathogens are present in the feces of ill, convalescent, or otherwise colonized persons. It is difficult for managers of food operations to identify food workers who may be excreting pathogens, even when these workers report their illnesses, because workers can shed pathogens during the prodrome phase of illness or can be long-term excretors or asymptomatic carriers. Some convalescing individuals excreted Salmonella for 102 days. Exclusion policies based on stool testing have been evaluated but currently are not considered effective for reducing the risk of enteric disease. A worker may exhibit obvious signs of illness, such as vomiting, but even if the ill worker immediately leaves the work environment, residual vomitus can contaminate food, contact surfaces, and fellow workers unless the clean-up process is meticulous. Skin infections and nasopharyngeal or oropharyngeal staphylococcal or streptococcal secretions also have been linked frequently to worker-associated outbreaks. Dermatitis, rashes, and painful hand lesions may cause workers to reduce or avoid hand washing. Regardless of the origin of the contamination, pathogens are most likely to be transmitted through the hands touching a variety of surfaces, highlighting the need for effective hand hygiene and the use of barriers throughout the work shift. PMID:19244919

Todd, Ewen C D; Greig, Judy D; Bartleson, Charles A; Michaels, Barry S

2008-12-01

289

Design an easy-to-use infection screening system for non-contact monitoring of vital-signs to prevent the spread of pandemic diseases.  

PubMed

The outbreak of infectious diseases such as influenza, dengue fever, and severe acute respiratory syndrome (SARS) are threatening the global health. Especially, developing countries in the South-East Asia region have been at serious risk. Rapid and highly reliable screening of infection is urgently needed during the epidemic season at mass gathering places, such as airport quarantine facilities, public health centers, and hospital outpatients units, etc. To meet this need, our research group is currently developing a multiple vital-signs based infection screening system that can perform human medical inspections within 15 seconds. This system remotely monitors facial temperature, heart and respiration rates using a thermopile array and a 24-GHz microwave radar, respectively. In this work, we redesigned our previous system to make a higher performance with a user-friendly interface. Moreover, the system newly included a multivariable logistic regression model (MLRM) to determine the possibility of infection. We tested the system on 34 seasonal influenza patients and 35 normal control subjects at the Japan Self-Defense Forces Central Hospital. The sensitivity and specificity of the screening system using the MLRM were 85.3% and 88.6%, respectively. PMID:25571068

Guanghao Sun; Nguyen Quang Vinh; Matsuoka, Ayumu; Miyata, Keisuke; Chen, Chris; Ueda, Akiko; Seokjin Kim; Hakozaki, Yukiya; Abe, Shigeto; Takei, Osamu; Matsui, Takemi

2014-08-01

290

Asymmetrically interacting spreading dynamics on complex layered networks  

PubMed Central

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

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

2014-01-01

291

Asymmetrically interacting spreading dynamics on complex layered networks  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

292

9 CFR 319.762 - Ham spread, tongue spread, and similar products.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Ham spread, tongue spread, and similar products...Meat Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and similar products. “Ham Spread,” “Tongue Spread,”...

2012-01-01

293

9 CFR 319.762 - Ham spread, tongue spread, and similar products.  

... 2014-01-01 2014-01-01 false Ham spread, tongue spread, and similar products...Meat Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and similar products. “Ham Spread,” “Tongue Spread,”...

2014-01-01

294

9 CFR 319.762 - Ham spread, tongue spread, and similar products.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Ham spread, tongue spread, and similar products...Meat Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and similar products. “Ham Spread,” “Tongue Spread,”...

2010-01-01

295

9 CFR 319.762 - Ham spread, tongue spread, and similar products.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 2011-01-01 false Ham spread, tongue spread, and similar products...Meat Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and similar products. “Ham Spread,” “Tongue Spread,”...

2011-01-01

296

9 CFR 319.762 - Ham spread, tongue spread, and similar products.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 2013-01-01 false Ham spread, tongue spread, and similar products...Meat Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and similar products. “Ham Spread,” “Tongue Spread,”...

2013-01-01

297

Beam Spreading Devices  

NASA Astrophysics Data System (ADS)

Effective use of a particle beam for radiotherapy necessitates delivery of that beam in such a way that it covers the target volume with a prescribed dose distribution. The particle beam extracted from an accelerator normally has beam dimensions smaller than that of a typical target. Therefore, that beam has to be spread out to match the target volume. This chapter will discuss aspects of the transverse and longitudinal spreading techniques using scattering and scanning techniques and some of the devices used to implement these techniques.

Flanz, Jay

298

Shipping and the Spread of Infectious Salmon Anemia in Scottish Aquaculture  

Microsoft Academic Search

Long-distance transport of pathogens plays a critical role in the emergence of novel diseases. Shipping is a major contributor to such transport, and the role of ships in spreading disease has been recognized for centu- ries. However, statistical confirmation of pathogen spread by shipping is usually impractical. We present evi- dence of invasive spread of infectious salmon anemia in the

Alexander G. Murray; Ronald J. Smith; Ronald M. Stagg

2002-01-01

299

Emergence of blind areas in information spreading.  

PubMed

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

Zhang, Zi-Ke; Zhang, Chu-Xu; Han, Xiao-Pu; Liu, Chuang

2014-01-01

300

Molecular analysis of spring viraemia of carp virus in China: a fatal aquatic viral disease that might spread in East Asian.  

PubMed

Spring viraemia of carp (SVC) is a fatal viral disease for cyprinid fish, which is caused by spring viraemia of carp virus (SVCV). To date, no SVC outbreak has been reported in China. Between 1998 and 2002, outbreaks of SVC were reported in ornamental and wild fish in Europe and America, imported from multiple sources including China. Based on phylogenetic analysis, the viral strain isolated from America was shown to be originated from Asia. These outbreaks not only resulted in huge economic losses, but also raise an interesting question as to whether SVCV really exists in China and if so, is it responsible for SVC outbreaks? From 2002 to 2006, we screened 6700 samples from ornamental fish farms using the cell culture method of the Office International des Epizooties (OIE), and further verified the presence of SVCV by ELISA and real-time quantitative RT-PCR. Two infected samples were found and the complete genome of SVCV was sequenced from one of the isolates, termed SVCV-C1. Several unique hallmarks of SVCV-C1 were identified, including six amino acid (KSLANA) insertion in the viral RNA-dependent RNA polymerase (L) protein and ten nucleotide insertion in the region between glycoprotein (G) and L genes in European SVCV strains. Phylogenetic tree analysis of the full-length G protein of selected SVCV isolates from the United Kingdom and United States revealed that G proteins could be classified into Ia and Id sub genogroups. The Ia sub genogroup can be further divided into newly defined sub genogroups Ia-A and Ia-B. The isolates derived from the United States and China including the SVCV-C1 belongs to in the Ia-A sub genogroup. The SVCV-C1 G protein shares more than 99% homology with the G proteins of the SVCV strains from England and the United States, making it difficult to compare their pathogenicity. Comparison of the predicted three-dimensional structure based on the published G protein sequences from five SVCV strains revealed that the main differences were in the loops of the pleckstrin homology domains. Since SVCV is highly pathogenic, we speculate that SVC may therefore pose a serious threat to farmed cyprinid fish in China. PMID:19623265

Zhang, Nian Zhi; Zhang, Li Feng; Jiang, Yi Nan; Zhang, Ting; Xia, Chun

2009-01-01

301

Salmon Spread Ingredients  

E-print Network

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

Liskiewicz, Maciej

302

Systems and spread.  

PubMed

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

Siriwardena, A Niroshan; Gillam, Steve

2014-01-01

303

Impact of travel on international spread of antimicrobial resistance  

Microsoft Academic Search

Antimicrobial resistance, an escalating problem worldwide, affects a broad range of human diseases. Excessive and inappropriate drug usage is the key driver for the emergence of resistant organisms. Travel, trade and mass migration form an important mode for their spread. The use of molecular biology provides the means of understanding the genesis and spread of the genes for drug resistance.

Ziad A Memish; S Venkatesh; Atef M Shibl

2003-01-01

304

Response Strategies in Deterministic Models of Spread: Vaccination and Firefighting  

E-print Network

38 Chapter 3 Response Strategies in Deterministic Models of Spread: Vaccination and Firefighting 3 are occurring. This is particularly relevant in disease spread processes, where vaccinations and quarantines. The response allowed is only a limited number of vaccinations of non-infected vertices. Specifically, let G

Hartke, Stephen

305

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

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

Madsen, Elainie Alenkćr; Persson, Tomas; Sayehli, Susan; Lenninger, Sara; Sonesson, Göran

2013-01-01

306

Chimpanzees show a developmental increase in susceptibility to contagious yawning: a test of the effect of ontogeny and emotional closeness on yawn contagion.  

PubMed

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

Madsen, Elainie Alenkćr; Persson, Tomas; Sayehli, Susan; Lenninger, Sara; Sonesson, Göran

2013-01-01

307

Contagious Deposition of Seeds in Spider Monkeys' Sleeping Trees Limits Effective Seed Dispersal in Fragmented Landscapes  

PubMed Central

The repeated use of sleeping sites by frugivorous vertebrates promotes the deposition and aggregation of copious amounts of seeds in these sites. This spatially contagious pattern of seed deposition has key implications for seed dispersal, particularly because such patterns can persist through recruitment. Assessing the seed rain patterns in sleeping sites thus represents a fundamental step in understanding the spatial structure and regeneration of plant assemblages. We evaluated the seed rain produced by spider monkeys (Ateles geoffroyi) in latrines located beneath 60 sleeping trees in two continuous forest sites (CFS) and three forest fragments (FF) in the Lacandona rainforest, Mexico. We tested for differences among latrines, among sites, and between forest conditions in the abundance, diversity (?-, ?- and, ?-components) and evenness of seed assemblages. We recorded 45,919 seeds ?5 mm (in length) from 68 species. The abundance of seeds was 1.7 times higher in FF than in CFS, particularly because of the dominance of a few plant species. As a consequence, community evenness tended to be lower within FF. ?-diversity of common and dominant species was two times greater among FF than between CFS. Although mean ?-diversity per latrine did not differ among sites, the greater ?-diversity among latrines in CFS increased ?-diversity in these sites, particularly when considering common and dominant species. Our results support the hypothesis that fruit scarcity in FF can ‘force’ spider monkeys to deplete the available fruit patches more intensively than in CFS. This feeding strategy can limit the effectiveness of spider monkeys as seed dispersers in FF, because (i) it can limit the number of seed dispersers visiting such fruit patches; (ii) it increases seed dispersal limitation; and (iii) it can contribute to the floristic homogenization (i.e., reduced ?-diversity among latrines) in fragmented landscapes. PMID:24586705

González-Zamora, Arturo; Arroyo-Rodríguez, Víctor; Escobar, Federico; Rös, Matthias; Oyama, Ken; Ibarra-Manríquez, Guillermo; Stoner, Kathryn E.; Chapman, Colin A.

2014-01-01

308

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)

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.

Wen, Tzai-Hung

2014-05-01

309

Spread spectrum image steganography.  

PubMed

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

Marvel, L M; Boncelet, C R; Retter, C T

1999-01-01

310

Epidemic spreading in time-varying community networks  

NASA Astrophysics Data System (ADS)

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold qc. The epidemic will survive when q > qc and die when q < qc. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

Ren, Guangming; Wang, Xingyuan

2014-06-01

311

Sea Floor Spreading  

NSDL National Science Digital Library

Sea floor spreading is demonstrated using a model consisting of two classroom desks and an 8-foot strip of paper. Changes in polarity are indicated using a felt marker. The investigation supports material presented in chapter 3, "What Heats the Earth's Interior?" in the textbook Energy flow, part of the Global System Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

312

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...

313

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...

314

PREDICTING ROOT SPREAD FROM TRUNK DIAMETER AND BRANCH SPREAD  

Microsoft Academic Search

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.

Edward F. Gilman

1989-01-01

315

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

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

Kaleta, E F

2002-09-01

316

Prevent the Spread of Zoonotic Diseases  

E-print Network

, including borrowed equipment ? vehicle and trailer tires and undercarriages after returning home ? from another farm First, clean equipment and surfaces with a scrub brush and detergent ? mixed in water to remove all soil, food, and manure. Then..., and under ? jewelry. Wash for at least 15 seconds to remove germs.? When warm water is not available, wash for a longer time.? When soap and water are not available, use an alcohol-based hand ? sanitizer. Practice Food Safety Do not consume unpasteurized...

Pena, Josefa

2008-11-10

317

Prevent the Spread of Zoonotic Diseases (Spanish)  

E-print Network

ropa por separado de la ropa de su familia.? Use detergente.? Use blanqueador de uso casero (lej?a).? Use agua 130 grados F.? Seque la ropa al sol o en una secadora.? Desinfecte para prevenir la transmisi?n de enfermedades Limpie y desinfecte... hacienda Primero, quite toda tierra, alimento y esti?rcol de las superficies con ? agua, un cepillo para fregar y una soluci?n de agua y detergente. Despu?s, desinfecte con una soluci?n de blanqueador (lej?a) de uso ? casero o un desinfectante aprobado...

Pena, Josefa

2008-11-10

318

The Creation of a Contagious H5N1 Influenza Virus: Implications for the Education of Life Scientists  

PubMed Central

The paper contends that the ongoing controversy surrounding the creation of a contagious H5N1 influenza virus has already exposed the severe limitations of the possibility of preventing the hostile misuse of the life sciences by dint of oversight of proposals and publications. It further argues that in order to prevent the potential wholesale militarisation of the life sciences, it is essential that life scientists become aware of their responsibilities within the context of the Biological and Toxin Weapons Convention (BTWC) and actively contribute their expertise to strengthening the biological weapons non-proliferation regime . PMID:22984642

Novossiolova, Tatyana; Minehata, Masamichi; Dando, Malcolm

2012-01-01

319

Differentially Expressed Genes in Bordetella pertussis Strains Belonging to a Lineage Which Recently Spread Globally  

PubMed Central

Pertussis is a highly contagious, acute respiratory disease in humans caused by the Gram-negative pathogen Bordetella pertussis. Pertussis has resurged in the face of intensive vaccination and this has coincided with the emergence of strains carrying a particular allele for the pertussis toxin promoter, ptxP3, which is associated with higher levels of pertussis toxin (Ptx) production. Within 10 to 20 years, ptxP3 strains have nearly completely replaced the previously dominant ptxP1 strains resulting in a worldwide selective sweep. In order to identify B. pertussis genes associated with the selective sweep, we compared the expression of genes in ptxP1 and ptxP3 strains that are under control of the Bordetella master virulence regulatory locus (bvgASR). The BvgAS proteins comprise a two component sensory transduction system which is regulated by temperature, nicotinic acid and sulfate. By increasing the sulfate concentration, it is possible to change the phase of B. pertussis from virulent to avirulent. Until recently, the only distinctive phenotype of ptxP3 strains was a higher Ptx production. Here we identify additional phenotypic differences between ptxP1 and ptxP3 strains which may have contributed to its global spread by comparing global transcriptional responses under sulfate-modulating conditions. We show that ptxP3 strains are less sensitive to sulfate-mediated gene suppression, resulting in an increased production of the vaccine antigens pertactin (Prn) and Ptx and a number of other virulence genes, including a type III secretion toxin, Vag8, a protein involved in complement resistance, and lpxE involved in lipid A modification. Furthermore, enhanced expression of the vaccine antigens Ptx and Prn by ptxP3 strains was confirmed at the protein level. Identification of genes differentially expressed between ptxP1 and ptxP3 strains may elucidate how B. pertussis has adapted to vaccination and allow the improvement of pertussis vaccines by identifying novel vaccine candidates. PMID:24416242

de Gouw, Daan; Hermans, Peter W. M.; Bootsma, Hester J.; Zomer, Aldert; Heuvelman, Kees; Diavatopoulos, Dimitri A.; Mooi, Frits R.

2014-01-01

320

Hybrid spread spectrum radio system  

DOEpatents

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.

Smith, Stephen F. (London, TN) [London, TN; Dress, William B. (Camas, WA) [Camas, WA

2010-02-09

321

Computer simulation to support policy-making in Aujeszky's disease control  

Microsoft Academic Search

Aujeszky's disease is a contagious viral disease that affects the central nervous system of pigs. Several eradication programs or measures are available, each of them providing different results. Determining the preferred strategy is to a large extent a matter of economic consideration.Under the EU rules, countries or regions that are Aujeszky-free can ban imports of breeding animals carrying antibodies of

J. A. A. M. Buijtels

1997-01-01

322

SNP discovery and marker development for disease resistance candidate genes in common carp (Cyprinus carpio)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Single nucleotide polymorphisms (SNPs) in immune response genes have been reported as markers of susceptibility to infectious diseases in human and livestock. A disease caused by cyprinid herpes virus 3 (CyHV-3) is highly contagious and virulent in common carp. With the aim to investigate the gene...

323

The Galapagos Spreading Center  

NSDL National Science Digital Library

In this lesson, with a focus on mid-ocean ridges, students will discover how new ocean floor is formed. They will study the processes involved in creating new seafloor at a mid-ocean ridge, investigate the Galapagos Spreading Center system, and understand the different types of plate motion associated with ridge segments and transform faults. This hands-on activity uses online data resources and includes: focus questions, learning objectives, teaching time, audio/visual materials needed, background information, learning procedures, evaluations, extensions, as well as resources and student handouts.

324

Tumor-activated protein promotes cancer spread  

Cancer.gov

Researchers at the University of California, San Diego School of Medicine and UC San Diego Moores Cancer Center report that cancers physically alter cells in the lymphatic system – a network of vessels that transports and stores immune cells throughout the body – to promote the spread of disease, a process called metastasis. The findings are published in this week’s online Early Edition of the Proceedings of the National Academy of Sciences.

325

Rifts in Spreading Wax Layers  

E-print Network

We report experimental results on the rift formation between two freezing wax plates. The plates were pulled apart with constant velocity, while floating on the melt, in a way akin to the tectonic plates of the earth's crust. At slow spreading rates, a rift, initially perpendicular to the spreading direction, was found to be stable, while above a critical spreading rate a "spiky" rift with fracture zones almost parallel to the spreading direction developed. At yet higher spreading rates a second transition from the spiky rift to a zig-zag pattern occurred. In this regime the rift can be characterized by a single angle which was found to be dependent on the spreading rate. We show that the oblique spreading angles agree with a simple geometrical model. The coarsening of the zig-zag pattern over time and the three-dimensional structure of the solidified crust are also discussed.

Rolf Ragnarsson; J. Lewis Ford; Christian D. Santangelo; Eberhard Bodenschatz

1995-10-19

326

Did ice-age bovids spread tuberculosis?  

PubMed

Pathognomonic metacarpal undermining is a skeletal pathology that has been associated with Mycobacterium tuberculosis in bovids. Postcranial artiodactyl, perissodactyl, and carnivore skeletons were examined in major university and museum collections of North America and Europe for evidence of this and other pathology potentially attributable to tuberculosis. Among nonproboscidean mammals from pre-Holocene North America, bone lesions indicative of tuberculosis were restricted to immigrant bovids from Eurasia. No bone lesions compatible with diagnosis of tuberculosis were found in large samples of other pre-Holocene (164 Oligocene, 397 Miocene, and 1,041 Plio-Pleistocene) North American mammals, including 114 antilocaprids. Given the unchanged frequency of bovid tubercular disease during the Pleistocene, it appears that most did not die from the disease but actually reached an accommodation with it (as did the mastodon) (Rothschild and Laub 2006). Thus, they were sufficiently long-lived to assure greater spread of the disease. The relationships of the proboscidean examples need further study, but present evidence suggests a Holarctic spread of tuberculosis during the Pleistocene, with bovids acting as vectors. While the role of other animals in the transmission of tuberculosis could be considered, the unique accommodation achieved by bovids and mastodons makes them the likely "culprits" in its spread. PMID:16896974

Rothschild, Bruce M; Martin, Larry D

2006-11-01

327

Did ice-age bovids spread tuberculosis?  

NASA Astrophysics Data System (ADS)

Pathognomonic metacarpal undermining is a skeletal pathology that has been associated with Mycobacterium tuberculosis in bovids. Postcranial artiodactyl, perissodactyl, and carnivore skeletons were examined in major university and museum collections of North America and Europe for evidence of this and other pathology potentially attributable to tuberculosis. Among nonproboscidean mammals from pre-Holocene North America, bone lesions indicative of tuberculosis were restricted to immigrant bovids from Eurasia. No bone lesions compatible with diagnosis of tuberculosis were found in large samples of other pre-Holocene (164 Oligocene, 397 Miocene, and 1,041 Plio Pleistocene) North American mammals, including 114 antilocaprids. Given the unchanged frequency of bovid tubercular disease during the Pleistocene, it appears that most did not die from the disease but actually reached an accommodation with it (as did the mastodon) (Rothschild and Laub 2006). Thus, they were sufficiently long-lived to assure greater spread of the disease. The relationships of the proboscidean examples need further study, but present evidence suggests a Holarctic spread of tuberculosis during the Pleistocene, with bovids acting as vectors. While the role of other animals in the transmission of tuberculosis could be considered, the unique accommodation achieved by bovids and mastodons makes them the likely “culprits” in its spread.

Rothschild, Bruce M.; Martin, Larry D.

2006-11-01

328

Diarrhoeal Disease  

MedlinePLUS

... of diarrhoeal disease can be prevented through safe drinking-water and adequate sanitation and hygiene. Globally, there are ... organisms. Infection is spread through contaminated food or drinking-water, or from person-to-person as a result ...

329

A new kinetic model to discuss the control of panic spreading in emergency  

NASA Astrophysics Data System (ADS)

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.

Chen, Guanghua; Shen, Huizhang; Chen, Guangming; Ye, Teng; Tang, Xiangbin; Kerr, Naphtali

2015-01-01

330

Repeated exposure to 5D9, an inhibitor of 3D polymerase, effectively limits the replication of Foot-and-Mouth Disease Virus in host cells.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-Mouth Disease (FMD) is a highly contagious disease of livestock caused by a highly variable RNA virus that has seven serotypes and more than sixty subtypes. Both prophylactic and post-infection means of controlling the disease outbreak, including universally applicable vaccines and emergenc...

331

Prions: Generation and Spread Versus Neurotoxicity  

PubMed Central

Neurodegenerative diseases are characterized by the aggregation of misfolded proteins in the brain. Among these disorders are the prion diseases, which are transmissible, and in which the misfolded proteins (“prions”) are also the infectious agent. Increasingly, it appears that misfolded proteins in Alzheimer and Parkinson diseases and the tauopathies also propagate in a “prion-like” manner. However, the association between prion formation, spread, and neurotoxicity is not clear. Recently, we showed that in prion disease, protein misfolding leads to neurodegeneration through dysregulation of generic proteostatic mechanisms, specifically, the unfolded protein response. Genetic and pharmacological manipulation of the unfolded protein response was neuroprotective despite continuing prion replication, hence dissociating this from neurotoxicity. The data have clear implications for treatment across the spectrum of these disorders, targeting pathogenic processes downstream of protein misfolding. PMID:24860100

Halliday, Mark; Radford, Helois; Mallucci, Giovanna R.

2014-01-01

332

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...

333

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...

334

Homodimerization of Marek's disease virus encoded Meq protein is not sufficient for transformation of lymphocytes in chicken  

Technology Transfer Automated Retrieval System (TEKTRAN)

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. MDV codes for an oncoprotein, Meq, which shares resemblance wit...

335

Chicken Heat Shock Protein 90 Is a Component of the Putative Cellular Receptor Complex of Infectious Bursal Disease Virus  

Microsoft Academic Search

Infectious bursal disease virus (IBDV) causes a highly contagious disease in young chicks and leads to significant economic losses in the poultry industry. The capsid protein VP2 of IBDV plays an important role in virus binding and cell recognition. VP2 forms a subviral particle (SVP) with immunogenicity similar to that of the IBDV capsid. In the present study, we first

Ta-Wei Lin; Chi-Wen Lo; Su-Yuan Lai; Ruey-Jane Fan; Chao-Jung Lo; Yu-mei Chou; Rekha Thiruvengadam; Andrew H.-J. Wang; Min-Ying Wang

2007-01-01

336

The geographical spread of influenza.  

PubMed Central

How infectious diseases spread in space within one cycle of an epidemic is an important question that has received considerable theoretical attention. There are, however, few empirical studies to support theoretical approaches, because data are scarce. Weekly reports obtained since 1984 from a network of general practitioners spanning the entire French territory allows the analysis of the spatio-temporal dynamics of influenza over a fine spatial scale. This analysis indicates that diffusion over long distances, possibly due to global transportation systems, is so quick that homogeneous global mixing occurs before the epidemic builds up within infected patches. A simple model in which the total number of cases is given by the empirical time-series and cases are randomly assigned to patches according to the population weight of the patches exhibits the same spatio-temporal properties as real epidemic cycles: homogeneous mixing models constitute appropriate descriptions, except in the vicinity of the epidemic's peak, where geographic heterogeneities play a role. PMID:9921681

Bonabeau, E; Toubiana, L; Flahault, A

1998-01-01

337

Lattice Model for Influenza Spreading with Spontaneous Behavioral Changes  

PubMed Central

Individual behavioral response to the spreading of an epidemic plays a crucial role in the progression of the epidemic itself. The risk perception induces individuals to adopt a protective behavior, as for instance reducing their social contacts, adopting more restrictive hygienic measures or undergoing prophylaxis procedures. In this paper, starting with a previously developed lattice-gas SIR model, we construct a coupled behavior-disease model for influenza spreading with spontaneous behavioral changes. The focus is on self-initiated behavioral changes that alter the susceptibility to the disease, without altering the contact patterns among individuals. Three different mechanisms of awareness spreading are analyzed: the local spreading due to the presence in the neighborhood of infective individuals; the global spreading due to the news published by the mass media and to educational campaigns implemented at institutional level; the local spreading occurring through the “thought contagion” among aware and unaware individuals. The peculiarity of the present approach is that the awareness spreading model is calibrated on available data on awareness and concern of the population about the risk of contagion. In particular, the model is validated against the A(H1N1) epidemic outbreak in Italy during the season, by making use of the awareness data gathered by the behavioral risk factor surveillance system (PASSI). We find that, increasing the accordance between the simulated awareness spreading and the PASSI data on risk perception, the agreement between simulated and experimental epidemiological data improves as well. Furthermore, we show that, within our model, the primary mechanism to reproduce a realistic evolution of the awareness during an epidemic, is the one due to globally available information. This result highlights how crucial is the role of mass media and educational campaigns in influencing the epidemic spreading of infectious diseases. PMID:24376727

Fierro, Annalisa; Liccardo, Antonella

2013-01-01

338

Contagious Itch in Humans. A Study of Visual “Transmission” of Itch in Atopic Dermatitis and Healthy Subjects  

PubMed Central

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

Papoiu, A.D.P.; Wang, H.; Coghill, R.C.; Chan, Y-H.; Yosipovitch, G.

2011-01-01

339

Disease control during the colonial period in Australia.  

PubMed

The first permanent European settlers of Australia arrived in 1788 to establish a penal colony at Sydney, New South Wales (NSW). As the colony grew and wool production increased, more free settlers and emancipists developed farming in inland Australia. During the 1840s veterinarians commenced arriving in small numbers but they were not closely associated with the development and execution of disease control programs, which was left to lay inspectors of stock. The arrival of William Tyson Kendall and coordinated action with Graham Mitchell led to the establishment of a private veterinary college following the passage of veterinary surgeons legislation in Victoria. From this time, veterinarians came to be appointed to positions formerly occupied by lay inspectors and the veterinary profession was able to take up the role of planning and executing government-led disease control programs. From a colony relying on wool for export to the UK, technical advancements in meat freezing and pasture improvement widened the range and increased the quantity of exported products. Before the advent of veterinary advances, sheep scab was eradicated, a vaccine was developed for anthrax and glanders infection of horses was prevented entry to Australia. Graduates from the Melbourne Veterinary College spread across Australia and in this period a conservative quarantine policy was developed following inaction to control an outbreak of contagious bovine pleuropneumonia (CBPP) and the escape of rabbits to form a plague across the continent. Coordinated control of CBPP had to await the next century and advancement of technology increased our understanding of bacteriology and immunity of infectious diseases. Veterinary services were provided to the militia sent by the colonies to the Boer Wars in South Africa 1987-1901 and the veterinarians from Victoria were led by an Australian trained veterinarian. PMID:21696369

Turner, A J

2011-07-01

340

Agent-based modeling to simulate the dengue spread  

NASA Astrophysics Data System (ADS)

In this paper, we introduce a novel method ABM in simulating the unique process for the dengue spread. Dengue is an acute infectious disease with a long history of over 200 years. Unlike the diseases that can be transmitted directly from person to person, dengue spreads through a must vector of mosquitoes. There is still no any special effective medicine and vaccine for dengue up till now. The best way to prevent dengue spread is to take precautions beforehand. Thus, it is crucial to detect and study the dynamic process of dengue spread that closely relates to human-environment interactions where Agent-Based Modeling (ABM) effectively works. The model attempts to simulate the dengue spread in a more realistic way in the bottom-up way, and to overcome the limitation of ABM, namely overlooking the influence of geographic and environmental factors. Considering the influence of environment, Aedes aegypti ecology and other epidemiological characteristics of dengue spread, ABM can be regarded as a useful way to simulate the whole process so as to disclose the essence of the evolution of dengue spread.

Deng, Chengbin; Tao, Haiyan; Ye, Zhiwei

2008-10-01

341

Contagious yawning in domestic dog puppies (Canis lupus familiaris): the effect of ontogeny and emotional closeness on low-level imitation in dogs.  

PubMed

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

Madsen, Elainie Alenkćr; Persson, Tomas

2013-03-01

342

Islamic Universities Spread through Africa  

ERIC Educational Resources Information Center

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…

Lindow, Megan

2007-01-01

343

Increased Spreading Activation in Depression  

ERIC Educational Resources Information Center

The dopaminergic system is implicated in depressive disorders and research has also shown that dopamine constricts lexical/semantic networks by reducing spreading activation. Hence, depression, which is linked to reductions of dopamine, may be associated with increased spreading activation. However, research has generally found no effects of…

Foster, Paul S.; Yung, Raegan C.; Branch, Kaylei K.; Stringer, Kristi; Ferguson, Brad J.; Sullivan, William; Drago, Valeria

2011-01-01

344

Gasping for truth : tracking the spread of SARS around the world  

NSDL National Science Digital Library

This is a lesson plan in which students investigate global responses to fighting the spread of severe acute respiratory syndrome. Students will read a newspaper article to discover what is being done to curb the spread of the deadly disease. Then, students will use a variety of different media to track the spread and other statistics related to the disease. Students will write news reports advising citizens of what to do in affected areas.

Dekorne, Clayton; Chin, Tanya Y.

2003-01-01

345

The contagious nature of imprisonment: an agent-based model to explain racial disparities in incarceration rates  

PubMed Central

We build an agent-based model of incarceration based on the susceptible–infected–suspectible (SIS) model of infectious disease propagation. Our central hypothesis is that the observed racial disparities in incarceration rates between Black and White Americans can be explained as the result of differential sentencing between the two demographic groups. We demonstrate that if incarceration can be spread through a social influence network, then even relatively small differences in sentencing can result in large disparities in incarceration rates. Controlling for effects of transmissibility, susceptibility and influence network structure, our model reproduces the observed large disparities in incarceration rates given the differences in sentence lengths for White and Black drug offenders in the USA without extensive parameter tuning. We further establish the suitability of the SIS model as applied to incarceration by demonstrating that the observed structural patterns of recidivism are an emergent property of the model. In fact, our model shows a remarkably close correspondence with California incarceration data. This work advances efforts to combine the theories and methods of epidemiology and criminology. PMID:24966237

Lum, Kristian; Swarup, Samarth; Eubank, Stephen; Hawdon, James

2014-01-01

346

Di#erential equation models for Aujeszky's Disease Virus (ADV) in Irish pig herds  

E-print Network

School of Mathematical Sciences, Dublin City University, Dublin 9, Ireland J. A. D. Appleby 2 School of Mathematical Sciences, Dublin City University, Dublin 9, Ireland. A. D. Wood 3 School of Mathematical Sciences, Dublin City University, Dublin 9, Ireland Abstract Aujeszky's Disease virus, (ADV) is a contagious viral

347

DEVELOPMENT OF A MAMMALIAN CELL-FREE SYSTEM TO INVESTIGATE REPLICATION OF F00T-AND-MOUTH DISEASE AND THE ROLE OF HOST FACTORS IN VIRUS SYNTHESIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) has been recognized as one of the most contagious viral disease of cloven-hoofed animals with important socioeconomic implications for animal product market and trade. Although the causative agent FMDV was first described in the 16th century, there are significant gaps ...

348

RECOMBINANT ENGINEERED SAT1 FOOT-AND-MOUTH DISEASE VIRUS AS AN APPROACH TO INVESTIGATE RECEPTOR USAGE AND GROWTH DETERMINANTS OF OUTBREAK STRAINS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth desease (FMD), a highly contagious viral disease of cattle, sheep, pigs and other cloven-hoofed animals has recently caused devastating epidemics world-wide. In the three South African Territories (SAT) types of foot-and-mouth disease virus (FMDV), the aetiological agent display grea...

349

THE LEADER PROTEINASE OF FOOT-AND-MOUTH DISEASE VIRUS INHIBITS THE INDUCTION OF INTERFERON BETA MRNA AND BLOCKS THE HOST INNATE IMMUNE RESPONSE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen of cloven hoofed animals that causes an economically devastating disease. We have previously shown that the virulence of FMDV correlates with the presence of the viral gene product Lpro (leader), a papain-like proteinase responsible...

350

Utilizing qualitative methods in survey design: Examining Texas cattle producers’ intent to participate in foot-and-mouth disease detection and control  

Microsoft Academic Search

The effective control of an outbreak of a highly contagious disease such as foot-and-mouth disease (FMD) in the United States will require a strong partnership between the animal agriculture industry and the government. However, because of the diverse number of economic, social, and psychological influences affecting livestock producers, their complete cooperation during an outbreak may not be assured. We conducted

Amy H. Delgado; Bo Norby; Wesley R. Dean; W. Alex McIntosh; H. Morgan Scott

351

THE CONTAGIOUS NATURE OF IMPRISONMENT: AN AGENT-BASED MODEL TO EXPLAIN RACIAL DISPARITIES IN  

E-print Network

IN INCARCERATION RATES KRISTIAN LUM1 , SAMARTH SWARUP1 , STEPHEN EUBANK1 , JAMES HAWDON2 1 Network Dynamics, Virginia Tech Abstract. We build an agent-based model of incarceration based on the SIS model of infectious disease propagation. Our central hypothesis is that the observed racial disparities in incarceration rates

Swarup, Samarth

352

Prevent the Spread of Norovirus  

MedlinePLUS

... Protect Yourself and Others from Norovirus Practice proper hand hygiene Wash your hands carefully with soap and water, ... in healthcare facilities Handwashing: Clean Hands Save Lives , hand- and water-related hygiene tips Six Tips to Help Prevent the Spread ...

353

Spreading dynamics of polymer nanodroplets.  

PubMed

The spreading of polymer droplets is studied using molecular dynamics simulations. To study the dynamics of both the precursor foot and the bulk droplet, large hemispherical drops of 200 000 monomers are simulated using a bead-spring model for polymers of chain length 10, 20, and 40 monomers per chain. We compare spreading on flat and atomistic surfaces, chain length effects, and different applications of the Langevin and dissipative particle dynamics thermostats. We find diffusive behavior for the precursor foot and good agreement with the molecular kinetic model of droplet spreading using both flat and atomistic surfaces. Despite the large system size and long simulation time relative to previous simulations, we find that even larger systems are required to observe hydrodynamic behavior in the hemispherical spreading droplet. PMID:14754218

Heine, David R; Grest, Gary S; Webb, Edmund B

2003-12-01

354

Epidemic spreading in complex networks  

NASA Astrophysics Data System (ADS)

The study of epidemic spreading in complex networks is currently a hot topic and a large body of results have been achieved. In this paper, we briefly review our contributions to this field, which includes the underlying mechanism of rumor propagation, the epidemic spreading in community networks, the influence of varying topology, and the influence of mobility of agents. Also, some future directions are pointed out.

Zhou, Jie; Liu, Zong-Hua

2008-09-01

355

Epidemic spreading in time-varying community networks  

SciTech Connect

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q?>?q{sub c} and die when q?spreading in complex networks with community structure.

Ren, Guangming, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China) [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xingyuan, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)] [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)

2014-06-15

356

Parity bit selected spreading sequences: a block coding approach to spread spectrum  

Microsoft Academic Search

Parity bits are used to select the spreading sequence from a set of orthogonal spreading sequences, The information bits are then spread by this spreading sequence. At the receiver, the spreading code employed is determined from the outputs of the filters that are matched to each spreading sequence. The information bits are then determined from the output of the specific

C. D'Amours

2005-01-01

357

Bridging a yawning chasm: EEG investigations into the debate concerning the role of the human mirror neuron system in contagious yawning.  

PubMed

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

Cooper, Nicholas R; Puzzo, Ignazio; Pawley, Adam D; Bowes-Mulligan, Ruby A; Kirkpatrick, Emma V; Antoniou, Pavlina A; Kennett, Steffan

2012-06-01

358

The role of hybridization in the origin and spread of asexuality in Daphnia  

PubMed Central

The molecular mechanisms leading to asexuality remain little understood despite their substantial bearing on why sexual reproduction is dominant in nature. Here we examine the role of hybridization in the origin and spread of obligate asexuality in Daphnia pulex, arguably the best-documented case of contagious asexuality. Obligately parthenogenetic (OP) clones of D. pulex have traditionally been separated into “hybrid” (Ldh SF) and “non-hybrid” (Ldh SS) forms because the lactase dehydrogenase (Ldh) locus distinguishes the cyclically parthenogenetic (CP) lake dwelling Daphnia pulicaria (Ldh FF) from its ephemeral pond dwelling sister species D. pulex (Ldh SS). The results of our population genetic analyses based on microsatellite loci suggest that both Ldh SS and SF OP individuals can originate from the crossing of CP female F1 (D. pulex × D. pulicaria) and backcrosses with males from OP lineages carrying genes that suppress meiosis specifically in female offspring. In previous studies, a suite of diagnostic markers was found to be associated with OP in Ldh SS D. pulex lineages. Our association mapping supports a similar genetic mechanism for the spread of obligate parthenogenesis in Ldh SF OP individuals. Interestingly, our study shows that CP D. pulicaria carry many of the diagnostic microsatellite alleles associated with obligate parthenogenesis. We argue that the assemblage of mutations that suppress meiosis and underlie obligate parthenogenesis in D. pulex originated due to a unique historical hybridization and introgression event between D. pulex and D. pulicaria. PMID:23879327

Xu, Sen; Innes, David J.; Lynch, Michael; Cristescu, Melania E.

2014-01-01

359

Interplay of network dynamics and ties heterogeneity on spreading dynamics  

E-print Network

The structure of a network dramatically affects the spreading phenomena unfolding upon it. The contact distribution of the nodes has long been recognized as the key ingredient in influencing the outbreak events. However, limited knowledge is currently available on the role of the weight of the edges on the persistence of a pathogen. At the same time, recent works showed a strong influence of temporal network dynamics on disease spreading. In this work we provide an analytical understanding, corroborated by numerical simulations, about the conditions for infected stable state in weighted networks. In particular, we reveal the role of heterogeneity of edge weights and of the dynamic assignment of weights on the ties in the network in driving the spread of the epidemic. In this context we show that when weights are dynamically assigned to ties in the network an heterogeneous distribution is able to hamper the diffusion of the disease, contrary to what happens when weights are fixed in time.

Ferreri, Luca; Giacobini, Mario; Perazzo, Silvia; Venturino, Ezio

2014-01-01

360

Effects on goat milk quality of the presence of Mycoplasma spp. in herds without symptoms of contagious agalactia.  

PubMed

This study was designed to assess the possible effects of mycoplasmas on the quality of milk produced by goat herds in a contagious agalactia (CA) endemic area with absence of classical symptoms. Several factors related to milk quality (percentages of fat, total protein, lactose and total solids, standard plate counts (SPC) and presence of Staphylococcus aureus) were compared in mycoplasma-infected and non-infected herds. To define the CA status of 26 herds on the island of Lanzarote (Spain), where CA is endemic, 570 individual milk samples and 266 bulk tank milk (BTM) samples were microbiologically analysed for the presence of Mycoplasma spp. A herd was considered infected by mycoplasmas when at least a sample (individual or BTM) was positive. BTM samples were also used to determine milk quality parameters. Mycoplasma infection was confirmed in 13 herds. A total of 31, 10 and 11 strains of Mycoplasma mycoides subsp. mycoides LC (MmmLC), Mp. agalactiae and Mp. capricolum subsp. capricolum were isolated. No significant differences were observed between the least square means of the variables fat, total protein, lactose and total solids or SPC recorded for the infected v. non-infected herds. The Staph. aureus status of a herd was also found to be independent of the presence of Mycoplasma spp. Our findings indicate that neither the presence of mycoplasmas in a goat herd with absence of classical symptoms seem to compromise the quality of the BTM. PMID:18922196

de la Fe, Christian; Sánchez, Antonio; Gutierrez, Aldo; Contreras, Antonio; Carlos Corrales, Juan; Assunçao, Patricia; Poveda, Carlos; Poveda, José B

2009-02-01

361

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

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

Delgado, Amy H; Norby, Bo; Scott, H Morgan; Dean, Wesley; McIntosh, W Alex; Bush, Eric

2014-12-01

362

Aerial dispersal and multiple-scale spread of epidemics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Disease spread has traditionally been described as a traveling wave of constant velocity. However, aerially dispersed pathogens capable of long distance dispersal (LDD) often have dispersal gradients with extended tails that could result in acceleration of the epidemic front over time and space. W...

363

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

364

First outbreak of sleeping disease in Switzerland: disease signs and virus characterization.  

PubMed

Sleeping disease is a contagious disease mainly of freshwater farmed rainbow trout, caused by salmonid alphavirus (SAV) Subtype 2. Here we describe the first case in Switzerland. Pathological changes ranged from acute pancreas necrosis to more chronic lesions with complete loss of exocrine pancreas and simultaneous degenerative, inflammatory and regenerative heart and muscle lesions. The partial sequencing of SAV E2 and nsp3 genes placed the Swiss SAV variant within the Subtype 2 clustering together with freshwater isolates from UK and continental Europe. Although mortality stayed low, growth rates were significantly reduced, making the disease economically relevant. PMID:25266904

Schmidt-Posthaus, Heike; Diserens, Nicolas; Jankowska Hjortaas, Monika; Knüsel, Ralph; Hirschi, Regula; Taksdal, Torunn

2014-09-30

365

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 ...

366

Braze alloy spreading on steel  

NASA Technical Reports Server (NTRS)

Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

Siewert, T. A.; Heine, R. W.; Lagally, M. G.

1978-01-01

367

Control of contagious bovine pleuropneumonia: Knowledge, attitudes, perceptions and practices in Narok district of Kenya  

PubMed Central

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

Kairu-Wanyoike, S.W.; Kiara, H.; Heffernan, C.; Kaitibie, S.; Gitau, G.K.; McKeever, D.; Taylor, N.M.

2014-01-01

368

Control of contagious bovine pleuropneumonia: knowledge, attitudes, perceptions and practices in Narok district of Kenya.  

PubMed

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

Kairu-Wanyoike, S W; Kiara, H; Heffernan, C; Kaitibie, S; Gitau, G K; McKeever, D; Taylor, N M

2014-08-01

369

Efficacy of two vaccine formulations against contagious bovine pleuropneumonia (CBPP) in Kenyan indigenous cattle  

PubMed Central

A live, attenuated vaccine is currently the only viable option to control of CBPP in Africa. It has been suggested that simple modifications to current vaccines and protocols might improve efficacy in the field. In this report we compared the current vaccine formulation with a buffered preparation that maintains Mycoplasma viability at ambient temperature for a longer time. Groups of animals were vaccinated with the two formulations and compared with non vaccinated groups. Half of the animals in each group were challenged 3 months post vaccination, the other half after 16 months. Protection levels were measured using the pathology index, calculated from post mortem scores of lesions from animals killed during the course of clinical disease. In the challenge at 3 months post vaccination, the protection levels were 52% and 77% for the modified and current vaccine preparations, respectively. At 16 months post vaccination, the protection levels were 56% and 62% for the modified and current vaccine preparations, respectively. These findings indicate that there are no differences in protection levels between the two vaccines. Because of its longer half life after reconstitution, the modified vaccine might be preferred in field situations where the reconstituted vaccine is likely not to be administered immediately. PMID:21963291

Nkando, Isabel; Ndinda, Joycelyne; Kuria, Joseph; Naessens, Jan; Mbithi, Flora; Schnier, Christian; Gicheru, Michael; McKeever, Declan; Wesonga, Hezron

2012-01-01

370

3D Fire Spread Animations  

NSDL National Science Digital Library

These excellent animations overlay animations of fire spread on 3D terrain that incorporates satellite imagery. A timeline shows the animation's current time relative to the fire occurrence, and an inset map provides an overhead view of the fire on a map that shows fuels by location. Animations are available for several wildfires that occurred in California.

Harry D. Johson

371

BANKING SPREADS IN LATIN AMERICA  

Microsoft Academic Search

Intermediation spreads in Latin America are high by international standards. This paper examines the determinants of bank interest margins in that region using bank- and country-level data from 85 countries, including 14 Latin American economies. The results suggest that Latin America has higher interest rates, less efficient banks, and larger reserve requirements than other regions and that these factors have

R. GASTON GELOS

2009-01-01

372

Spreading dynamics in complex networks  

NASA Astrophysics Data System (ADS)

Searching for influential spreaders in complex networks is an issue of great significance for applications across various domains, ranging from epidemic control, innovation diffusion, viral marketing, and social movement to idea propagation. In this paper, we first display some of the most important theoretical models that describe spreading processes, and then discuss the problem of locating both the individual and multiple influential spreaders respectively. Recent approaches in these two topics are presented. For the identification of privileged single spreaders, we summarize several widely used centralities, such as degree, betweenness centrality, PageRank, k-shell, etc. We investigate the empirical diffusion data in a large scale online social community—LiveJournal. With this extensive dataset, we find that various measures can convey very distinct information of nodes. Of all the users in the LiveJournal social network, only a small fraction of them are involved in spreading. For the spreading processes in LiveJournal, while degree can locate nodes participating in information diffusion with higher probability, k-shell is more effective in finding nodes with a large influence. Our results should provide useful information for designing efficient spreading strategies in reality.

Pei, Sen; Makse, Hernán A.

2013-12-01

373

Using a Bear Put Spread  

E-print Network

, Steve Amosson, Mark Waller and Kevin Dhuyvetter* 2 of the two options). The spread gain is limited to the difference between the strike price of the put option bought and the strike price of the put option sold, less commissions and the net cost...

Bevers, Stan; Amosson, Stephen H.; Waller, Mark L.; Dhuyvetter, Kevin C.

2008-10-07

374

Mid-Ocean Ridge Spreading  

NSDL National Science Digital Library

In this earth science activity (page 14 of the PDF), learners use layers of closed-cell foam to create their own model of the mid-ocean ridge in order to simulate seafloor spreading. Although this was created as a post-visit activity for a workshop about earth processes, it also makes an excellent stand alone activity.

2012-06-26

375

Using a Bull Call Spread  

E-print Network

The Bull Call Spread can be used to hedge against or to benefit from a rising market. The user buys a call option at a particular strike price and sells a call option at a higher strike price. Margin requirements, advantages and disadvantages...

Bevers, Stan; Amosson, Stephen H.; Waller, Mark L.; Dhuyvetter, Kevin C.

2008-10-07

376

The Telescope Point Spread Function  

Microsoft Academic Search

New observations are used to accurately define the stellar point spread function produced by atmospheric turbulence at the focus of large telescopes and to compare its profile to those computed from wavefronts characterized by various structure functions. Excellent agreement is found with the PSF expected from Kolmogorov statistics, except for the presence of an extended aureole of light which appears

Rene Racine

1996-01-01

377

A lattice model for influenza spreading.  

PubMed

We construct a stochastic SIR model for influenza spreading on a D-dimensional lattice, which represents the dynamic contact network of individuals. An age distributed population is placed on the lattice and moves on it. The displacement from a site to a nearest neighbor empty site, allows individuals to change the number and identities of their contacts. The dynamics on the lattice is governed by an attractive interaction between individuals belonging to the same age-class. The parameters, which regulate the pattern dynamics, are fixed fitting the data on the age-dependent daily contact numbers, furnished by the Polymod survey. A simple SIR transmission model with a nearest neighbors interaction and some very basic adaptive mobility restrictions complete the model. The model is validated against the age-distributed Italian epidemiological data for the influenza A(H1N1) during the [Formula: see text] season, with sensible predictions for the epidemiological parameters. For an appropriate topology of the lattice, we find that, whenever the accordance between the contact patterns of the model and the Polymod data is satisfactory, there is a good agreement between the numerical and the experimental epidemiological data. This result shows how rich is the information encoded in the average contact patterns of individuals, with respect to the analysis of the epidemic spreading of an infectious disease. PMID:23717512

Liccardo, Antonella; Fierro, Annalisa

2013-01-01

378

Epidemics of emerging animal diseases and food-borne infection problems over the last 5 years in Japan.  

PubMed

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

Yamane, Itsuro

2006-10-01

379

A model for multiseasonal spread of verticillium wilt of lettuce.  

PubMed

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

Wu, B M; Subbarao, K V

2014-09-01

380

Tuberculosis: Learn the Signs and Symptoms of TB Disease  

MedlinePLUS

... Compartir Tuberculosis (TB) is a disease caused by bacteria that are spread through the air from person ... TB. Tuberculosis (TB) is a disease caused by bacteria that are spread through the air from person ...

381

Spreading of a granular droplet.  

SciTech Connect

The influence of controlled vibrations on the granular rheology is investigated in a specifically designed experiment in which a granular film spreads under the action of horizontal vibrations. A nonlinear diffusion equation is derived theoretically that describes the evolution of the deposit shape. A self-similar parabolic shape (the granular droplet) and a spreading dynamics are predicted that both agree quantitatively with the experimental results. The theoretical analysis is used to extract effective friction coefficients between the base and the granular layer under sustained and controlled vibrations. A shear thickening regime characteristic of dense granular flows is evidenced at low vibration energy, both for glass beads and natural sand. Conversely, shear thinning is observed at high agitation.

Sanchez, I.; Raynaud, F.; Lanuza, J.; Andreotti, B.; Clement, E.; Aranson, I. S.; Materials Science Division; Univ. Simon; CNRS-ESPCI-Univ.

2007-01-01

382

Epidemic spread in coupled populations with seasonally varying migration rates  

NASA Astrophysics Data System (ADS)

The H5N1 strain of avian influenza has spread worldwide, and this spread may be due to seasonal migration of birds and mixing of birds from different regions in the wintering grounds. We studied a multipatch model for avian influenza with seasonally varying migration rates. The bird population was divided into two spatially distinct patches, or subpopulations. Within each patch, the disease followed the SIR (susceptible-infected-recovered) model for epidemic spread. Migration rates were varied periodically, with a net flux toward the breeding grounds during the spring and towards the wintering grounds during the fall. The case of two symmetric patches reduced to single-patch SIR dynamics. However, asymmetry in the birth and contact rates in the breeding grounds and wintering grounds led to bifurcations to longer period orbits and chaotic dynamics. We studied the bifurcation structure of the model and the phase relationships between outbreaks in the two patches.

Muzyczyn, Adam; Shaw, Leah B.

2009-03-01

383

Infectious Diseases  

NSDL National Science Digital Library

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.

NBC Learn

2010-10-07

384

Hydroclimatological And Anthropogenic Drivers For Cholera Spreading  

NASA Astrophysics Data System (ADS)

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.

Righetto, Lorenzo; Bertuzzo, Enrico; Mari, Lorenzo; Casagrandi, Renato; Gatto, Marino; Rinaldo, Andrea

2010-05-01

385

Assessing the role of spatial correlations during collective cell spreading.  

PubMed

Spreading cell fronts are essential features of development, repair and disease processes. Many mathematical models used to describe the motion of cell fronts, such as Fisher's equation, invoke a mean-field assumption which implies that there is no spatial structure, such as cell clustering, present. Here, we examine the presence of spatial structure using a combination of in vitro circular barrier assays, discrete random walk simulations and pair correlation functions. In particular, we analyse discrete simulation data using pair correlation functions to show that spatial structure can form in a spreading population of cells either through sufficiently strong cell-to-cell adhesion or sufficiently rapid cell proliferation. We analyse images from a circular barrier assay describing the spreading of a population of MM127 melanoma cells using the same pair correlation functions. Our results indicate that the spreading melanoma cell populations remain very close to spatially uniform, suggesting that the strength of cell-to-cell adhesion and the rate of cell proliferation are both sufficiently small so as not to induce any spatial patterning in the spreading populations. PMID:25026987

Treloar, Katrina K; Simpson, Matthew J; Binder, Benjamin J; McElwain, D L Sean; Baker, Ruth E

2014-01-01

386

On the Spatial Spread of Rabies among Foxes  

NASA Astrophysics Data System (ADS)

We present a simple model for the spatial spread of rabies among foxes and use it to quantify its progress in England if rabies were introduced. The model is based on the known ecology of fox behaviour and on the assumption that the main vector for the spread of the disease is the rabid fox. Known data and facts are used to determine real parameter values involved in the model. We calculate the speed of propagation of the epizootic front, the threshold for the existence of an epidemic, the period and distance apart of the subsequent cyclical epidemics which follow the main front, and finally we quantify a means for control of the spatial spread of the disease. By way of illustration we use the model to determine the progress of rabies up through the southern part of England if it were introduced near Southampton. Estimates for the current fox density in England were used in the simulations. These suggest that the disease would reach Manchester within about 3.5 years, moving at speeds as high as 100 km per year in the central region. The model further indicates that although it might seem that the disease had disappeared after the wave had passed it would reappear in the south of England after just over 6 years and at periodic times after that. We consider the possibility of stopping the spread of the disease by creating a rabies `break' ahead of the front through vaccination to reduce the population to a level below the threshold for an epidemic to exist. Based on parameter values relevant to England, we estimate its minimum width to be about 15 km. The model suggests that vaccination has considerable advantages over severe culling.

Murray, J. D.; Stanley, E. A.; Brown, D. L.

1986-11-01

387

Sea-Floor Spreading and Transform Faults  

ERIC Educational Resources Information Center

Presents the Crustal Evolution Education Project (CEEP) instructional module on Sea-Floor Spreading and Transform Faults. The module includes activities and materials required, procedures, summary questions, and extension ideas for teaching Sea-Floor Spreading. (SL)

Armstrong, Ronald E.; And Others

1978-01-01

388

Lexical Ambiguity: Making a Case against Spread  

ERIC Educational Resources Information Center

We argue for decreasing the use of the word "spread" when describing the statistical idea of dispersion or variability in introductory statistics courses. In addition, we argue for increasing the use of the word "variability" as a replacement for "spread."

Kaplan, Jennifer J.; Rogness, Neal T.; Fisher, Diane G.

2012-01-01

389

Possible spread of African horse sickness on the wind  

PubMed Central

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

Sellers, R. F.; Pedgley, D. E.; Tucker, M. R.

1977-01-01

390

Communicating About Communicable Disease  

NSDL National Science Digital Library

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.

IBM& #39; s Teachers Try Science program

2011-11-23

391

Optimization of network protection against virus spread  

E-print Network

Optimization of network protection against virus spread Eric Gourdin Orange Labs, Issy Abstract--The effect of virus spreading in a telecommunication network, where a certain curing strategy in nature, to name a few: the spread of viruses and worms in the Internet, as well as social engineering

Van Mieghem, Piet

392

Dry spreading of polymer solutions M. Boudoussier  

E-print Network

445 Dry spreading of polymer solutions M. Boudoussier Collège de France, Physique de la Matière/liquid and liquid/air). The polymer solute has two main effects : a) it modifies the spreading coefficient) solution film containing polymer and (c) film with no polymer. The droplet cannot spread only above

Boyer, Edmond

393

Modeling the Spread of Active Worms  

Microsoft Academic Search

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

Zesheng Chen; Lixin Gao; Kevin A. Kwiat

2003-01-01

394

Anterograde Spread of Herpes Simplex Virus Type 1 Requires Glycoprotein E and Glycoprotein I but Not Us9?  

PubMed Central

Anterograde neuronal spread (i.e., spread from the neuron cell body toward the axon terminus) is a critical component of the alphaherpesvirus life cycle. Three viral proteins, gE, gI, and Us9, have been implicated in alphaherpesvirus anterograde spread in several animal models and neuron culture systems. We sought to better define the roles of gE, gI, and Us9 in herpes simplex virus type 1 (HSV-1) anterograde spread using a compartmentalized primary neuron culture system. We found that no anterograde spread occurred in the absence of gE or gI, indicating that these proteins are essential for HSV-1 anterograde spread. However, we did detect anterograde spread in the absence of Us9 using two independent Us9-deleted viruses. We confirmed the Us9 finding in different murine models of neuronal spread. We examined viral transport into the optic nerve and spread to the brain after retinal infection; the production of zosteriform disease after flank inoculation; and viral spread to the spinal cord after flank inoculation. In all models, anterograde spread occurred in the absence of Us9, although in some cases at reduced levels. This finding contrasts with gE- and gI-deleted viruses, which displayed no anterograde spread in any animal model. Thus, gE and gI are essential for HSV-1 anterograde spread, while Us9 is dispensable. PMID:19570876

McGraw, Helen M.; Awasthi, Sita; Wojcechowskyj, Jason A.; Friedman, Harvey M.

2009-01-01

395

Epidemic spread in networks: Existing methods and current challenges  

PubMed Central

We consider the spread of infectious disease through contact networks of Configuration Model type. We assume that the disease spreads through contacts and infected individuals recover into an immune state. We discuss a number of existing mathematical models used to investigate this system, and show relations between the underlying assumptions of the models. In the process we offer simplifications of some of the existing models. The distinctions between the underlying assumptions are subtle, and in many if not most cases this subtlety is irrelevant. Indeed, under appropriate conditions the models are equivalent. We compare the benefits and disadvantages of the different models, and discuss their application to other populations (e.g., clustered networks). Finally we discuss ongoing challenges for network-based epidemic modeling.

Miller, Joel C.; Kiss, Istvan Z.

2014-01-01

396

Age, spreading rates, and spreading asymmetry of the world's ocean crust  

E-print Network

are determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading. Ages; seafloor spreading. Index Terms: 3040 Marine Geology and Geophysics: Plate tectonics (8150, 8155, 8157Age, spreading rates, and spreading asymmetry of the world's ocean crust R. Dietmar Mu

MĂĽller, Dietmar

397

Passive immunization of guinea pigs with llama single-domain antibody fragments against foot-and-mouth disease  

Microsoft Academic Search

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

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

398

Effects of internal fluctuations on the spreading of Hantavirus  

NASA Astrophysics Data System (ADS)

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.

Escudero, C.; Buceta, J.; de La Rubia, F. J.; Lindenberg, Katja

2004-12-01

399

SAW correlator spread spectrum receiver  

DOEpatents

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.

Brocato, Robert W

2014-04-01

400

Pharmacological modulation of spreading depolarizations.  

PubMed

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

Sánchez-Porras, Renán; Zheng, Zelong; Sakowitz, Oliver W

2015-01-01

401

Rapid Sequential Spread of Two Wolbachia Variants in Drosophila simulans  

PubMed Central

The maternally inherited intracellular bacteria Wolbachia can manipulate host reproduction in various ways that foster frequency increases within and among host populations. Manipulations involving cytoplasmic incompatibility (CI), where matings between infected males and uninfected females produce non-viable embryos, are common in arthropods and produce a reproductive advantage for infected females. CI was associated with the spread of Wolbachia variant wRi in Californian populations of Drosophila simulans, which was interpreted as a bistable wave, in which local infection frequencies tend to increase only once the infection becomes sufficiently common to offset imperfect maternal transmission and infection costs. However, maternally inherited Wolbachia are expected to evolve towards mutualism, and they are known to increase host fitness by protecting against infectious microbes or increasing fecundity. We describe the sequential spread over approximately 20 years in natural populations of D. simulans on the east coast of Australia of two Wolbachia variants (wAu and wRi), only one of which causes significant CI, with wRi displacing wAu since 2004. Wolbachia and mtDNA frequency data and analyses suggest that these dynamics, as well as the earlier spread in California, are best understood as Fisherian waves of favourable variants, in which local spread tends to occur from arbitrarily low frequencies. We discuss implications for Wolbachia-host dynamics and coevolution and for applications of Wolbachia to disease control. PMID:24068927

Kriesner, Peter; Hoffmann, Ary A.; Lee, Siu F.; Turelli, Michael; Weeks, Andrew R.

2013-01-01

402

Competing spreading processes on multiplex networks: Awareness and epidemics  

NASA Astrophysics Data System (ADS)

Epidemiclike spreading processes on top of multilayered interconnected complex networks reveal a rich phase diagram of intertwined competition effects. A recent study by the authors [C. Granell et al., Phys. Rev. Lett. 111, 128701 (2013)., 10.1103/PhysRevLett.111.128701] presented an analysis of the interrelation between two processes accounting for the spreading of an epidemic, and the spreading of information awareness to prevent infection, on top of multiplex networks. The results in the case in which awareness implies total immunization to the disease revealed the existence of a metacritical point at which the critical onset of the epidemics starts, depending on completion of the awareness process. Here we present a full analysis of these critical properties in the more general scenario where the awareness spreading does not imply total immunization, and where infection does not imply immediate awareness of it. We find the critical relation between the two competing processes for a wide spectrum of parameters representing the interaction between them. We also analyze the consequences of a massive broadcast of awareness (mass media) on the final outcome of the epidemic incidence. Importantly enough, the mass media make the metacritical point disappear. The results reveal that the main finding, i.e., existence of a metacritical point, is rooted in the competition principle and holds for a large set of scenarios.

Granell, Clara; Gómez, Sergio; Arenas, Alex

2014-07-01

403

Epidemic spreading on hierarchical geographical networks with mobile agents  

NASA Astrophysics Data System (ADS)

Hierarchical geographical traffic networks are critical for our understanding of scaling laws in human trajectories. Here, we investigate the susceptible-infected epidemic process evolving on hierarchical networks in which agents randomly walk along the edges and establish contacts in network nodes. We employ a metapopulation modeling framework that allows us to explore the contagion spread patterns in relation to multi-scale mobility behaviors. A series of computer simulations revealed that a shifted power-law-like negative relationship between the peak timing of epidemics ?0 and population density, and a logarithmic positive relationship between ?0 and the network size, can both be explained by the gradual enlargement of fluctuations in the spreading process. We employ a semi-analytical method to better understand the nature of these relationships and the role of pertinent demographic factors. Additionally, we provide a quantitative discussion of the efficiency of a border screening procedure in delaying epidemic outbreaks on hierarchical networks, yielding a rather limited feasibility of this mitigation strategy but also its non-trivial dependence on population density, infector detectability, and the diversity of the susceptible region. Our results suggest that the interplay between the human spatial dynamics, network topology, and demographic factors can have important consequences for the global spreading and control of infectious diseases. These findings provide novel insights into the combined effects of human mobility and the organization of geographical networks on spreading processes, with important implications for both epidemiological research and health policy.

Han, Xiao-Pu; Zhao, Zhi-Dan; Hadzibeganovic, Tarik; Wang, Bing-Hong

2014-05-01

404

A Spread Willingness Computing-Based Information Dissemination Model  

PubMed Central

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

Cui, Zhiming; Zhang, Shukui

2014-01-01

405

Cost-effectiveness of diagnostic strategies using quantitative real-time PCR and bacterial culture to identify contagious mastitis cases in large dairy herds.  

PubMed

Diagnostic strategies to detect contagious mastitis caused by Mycoplasma bovis, Staphylococcus aureus, and Streptococcus agalactiae in dairy herds during an outbreak have been minimally studied with regard to cost and diagnostic sensitivity. The objective of this cross-sectional study was to compare the cost-effectiveness of diagnostic strategies for identification of infected cows in two California dairy herds during contagious mastitis outbreaks. M. bovis was investigated in a subset of a herd (n=1210 cows) with an estimated prevalence of 2.8% (95% CI=1.9, 3.7), whereas Staph. aureus and Strep. agalactiae were studied in a second herd (n=351 cows) with an estimated prevalence of 3.4% (95% CI=1.5, 5.3) and 16.8% (95% CI=12.9, 20.7), respectively. Diagnostic strategies involved a combination of testing stages that utilized bacterial culture, quantitative real-time PCR (qPCR), or both. Strategies were applied to individual or pooled samples of 5, 10, 50 or 100 samples. Culture was considered the gold standard for sensitivity estimation of each strategy. The reference strategy was the strategy with the lowest cost per culture-positive cow which for both M. bovis and Strep. agalactiae consisted of 2 stages, culture of samples in pools of 5 followed by culture of individual samples in positive pools with a sensitivity of 73.5% (95% CI: 55.6, 87.1) and 96.6% (95% CI: 27.7, 84.8), respectively. The reference strategy for Staph. aureus consisted of 3 stages, culture of individual samples in pools of 100 (stage 1), culture constituents of those positive from stage 1 in pools of 5 (stage 2), culture constituents of those positive from stage 2 individually (stage 3) which resulted in a sensitivity of 58.3% (95% CI: 88.3, 99.6). The most cost-effective alternative to the reference strategy was whole herd milk culture for all 3 pathogens. QPCR testing was a component of the second most cost-effective alternative for M. bovis and the third most cost-effective alternatives for the 3 pathogens. A stochastic model was used to assess the effect of prevalence or herd size on the cost-effectiveness of diagnostic strategies. In the current study, increasing the prevalence of mastitis did not alter the ranking of strategies by cost-effectiveness. However, larger herds could benefit from testing larger pools such as 50 or 100 samples to improve cost-effectiveness. Several diagnostic strategy options exist to identify contagious mastitis in herds, decisions should be based on cost and sensitivity of the strategies available. PMID:24485275

Murai, Kiyokazu; Lehenbauer, Terry W; Champagne, John D; Glenn, Kathy; Aly, Sharif S

2014-03-01

406

Viral spreading of daily information in online social networks  

NASA Astrophysics Data System (ADS)

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.

Kawamoto, Tatsuro; Hatano, Naomichi

2014-07-01

407

Spreading synaptonemal complexes from Zea mays  

Microsoft Academic Search

Four different inversion heterozygotes of maize were examined for the occurrence of synaptic adjustment. Three substages of pachytene were identified in synaptonemal complex (SC) spreads using side-by-side comparisons of chromosome squashes with two-dimensional spreads of SCs. In SC spreads, inversion loop frequency did not change substantially from early through late pachytene for any of the four inversion heterozygotes examined. In

Lorinda K. Anderson; Stephen M. Stack; Jamie D. Sherman

1988-01-01

408

String spreading on a black hole horizon  

NASA Astrophysics Data System (ADS)

The phenomenon of string spreading on the black hole horizon, as originally discussed by Susskind, is considered in the exact curved Schwarzschild background. We consider an oscillating macroscopic string encircling the black hole and contracting towards the horizon. We then compute the angular and radial spreading of the string, as seen by a static observer at spatial infinity using fixed finite resolution time. Within our case study we find that there is indeed a spreading of the string in the angular direction, such that the string eventually covers the whole horizon. However, regarding the radial direction, we find that Lorentz-contraction suppresses the radial string spreading.

Larsen, A. L.; Nicolaidis, A.

1999-07-01

409

Wetting and spreading at the molecular scale  

NASA Technical Reports Server (NTRS)

We have studied the microscopic aspects of the spreading of liquid drops on a solid surface by molecular dynamics simulations of coexisting three-phase Lennard-Jones systems of liquid, vapor and solid. We consider both spherically symmetric atoms and chain-like molecules, and a range of interaction strengths. As the attraction between liquid and solid increases we observed a smooth transition in spreading regimes, from partial to complete to terraced wetting. In the terraced case, where distinct monomolecular layers spread with different velocities, the layers are ordered but not solid, with qualitative behavior resembling recent experimental findings, but with interesting differences in the spreading rate.

Koplik, Joel; Banavar, Jayanth R.

1994-01-01

410

Spread spectrum time domain reflectometry  

NASA Astrophysics Data System (ADS)

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.

Smith, Paul Samuel

411

BOSTON COLLEGE BIOLOGISTS BUILD A BETTER MOUSE MODEL Mice yield new finding on role of macrophage cells in cancer's spread  

E-print Network

for cancer lags behind basic research," said Seyfried. "How can you cure a disease when you have no model cells in cancer's spread CHESTNUT HILL, MA (April, 2008) ­ Researchers at Boston College have developed the first laboratory mouse model that mimics cancer's spread through the human body. Using their novel cell

Huang, Jianyu

412

The Determinants of Credit Spread Changes  

Microsoft Academic Search

Using dealer's quotes and transactions prices on straight industrial bonds, we investigate the determinants of credit spread changes. Variables that should in theory determine credit spread changes have rather limited explanatory power. Further, the residuals from this regression are highly cross-correlated, and principal components analysis implies they are mostly driven by a single common factor. Although we consider several macroeconomic

Pierre Collin-Dufresne; Robert S. Goldstein; J. Spencer Martin

2001-01-01

413

IMPROVED ANALYSIS OF SPREADING RESISTANCE MEASUREMENTS  

E-print Network

IMPROVED ANALYSIS OF SPREADING RESISTANCE MEASUREMENTS Scott T. Dunham, Nat Collins 1 and Nanseng In this paper, we describe a system for the analysis of spreading resistance data which includes carrier resistance analysis. Standard analysis techniques assume charge neutrality throughout the sample, which

Dunham, Scott

414

Attentional Spreading in Object-Based Attention  

ERIC Educational Resources Information Center

The authors investigated 2 effects of object-based attention: the spread of attention within an attended object and the prioritization of search across possible target locations within an attended object. Participants performed a flanker task in which the location of the task-relevant target was fixed and known to participants. A spreading

Richard, Ashleigh M.; Lee, Hyunkyu; Vecera, Shaun P.

2008-01-01

415

Physical modeling of slow seafloor spreading  

Microsoft Academic Search

A properly scaled thermo-mechanical experimental model of slow seafloor spreading is developed to investigate the mechanism of lithosphere accretion. The melt of a specially fabricated hydrocarbon compositional system is cooled from above in a tank. The crystallizing upper layer (the lithosphere) possesses semiplastic-semibrittle properties. Horizontal tension of the layer is produced by a paddle drawn at a constant rate. Spreading

Alexander I. Shemenda; Andrey L. Grocholsky

1994-01-01

416

The Landscape Ecology of Invasive Spread  

Microsoft Academic Search

Although habitat loss, fragmentation, and invasive species collectively pose the greatest threats to biodiversity, little theoretical or empirical research has addressed the effects of landscape structure—or spa- tial pattern more generally—on the spread of invasive species. Landscape ecology is the study of how spatial pattern affects ecological process. Thus, a landscape ecology of invasive spread involves understanding how spatial pattern,

2002-01-01

417

Spreading Codes Generator for Wireless CDMA Networks  

Microsoft Academic Search

The prime characteristic of spread spectrum modulated signals is that their bandwidth is greater than the information rate. In this way a redundancy is introduced that allows the severe levels of inteference inherent in the transmission of digital information over radio and satellite links to be overcome. Current spread spectrum applications are primarily in military communications; nevertheless, there is growing

Ernesto J. Cruselles; Miguel Soriano; José Luis Melús

1998-01-01

418

Gradual Spread of Market-Led Industrialization  

E-print Network

Gradual Spread of Market-Led Industrialization Jeffrey D. Sachs and Xiaokai Yang CID Working Paper Paper no. 11 Gradual Spread of Market-Led Industrialization Jeffrey D. Sachs and Xiaokai Yang* Abstract the network effects of industrialization, though this function is not perfect. Hence, market led

419

Environmental performance indicators of organic spreading machines  

E-print Network

1 Environmental performance indicators of organic spreading machines M. Rousselet1 *, J. C. Roux1 of solid and liquid organic product and in measuring performances of commercial spreaders. The indicators spreading), soil impact (compaction, area, and wheel pressure), performance (energy consumption, capacity

Paris-Sud XI, Université de

420

Upward flame spread over corrugated cardboard  

Microsoft Academic Search

As part of a study of the combustion of boxes of commodities, rates of upward flame spread during early-stage burning were observed during experiments on wide samples of corrugated cardboard. The rate of spread of the flame front, defined by the burning pyrolysis region, was determined by visually averaging the pyrolysis front position across the fuel surface. The resulting best

M. J. Gollner; F. A. Williams; A. S. Rangwala

2011-01-01

421

Spreading process of the northern Mariana Trough: Rifting-spreading transition at 22N  

E-print Network

southward from incipient rifting to seafloor spreading within this region. This study aims to clarify of seafloor spreading after the transition. The new data set includes swath bathymetry with side- scan images is proved by seafloor-spreading fabric in the bathymetry, clear magnetic lineations, and the bull

Utrecht, Universiteit

422

The early pathogenesis of foot-and-mouth disease in pigs infected by contact: a quantitative time-course study using TaqMan RT-PCR  

Microsoft Academic Search

Foot-and-mouth disease (FMD) is a highly contagious, economically important virus disease of cloven-hoofed animals. The objective of the present study was to examine the early pathogenesis of FMD in pigs by a quantitative time-course study. Under experimental conditions, recipient pigs were infected by contact with donor pigs affected by FMD. Every 24 h from day 1 to day 4 after

Soren Alexandersen; Martin B. Oleksiewicză; Alex I. Donaldson

423

Spread of white-nose syndrome on a network regulated by geography and climate.  

PubMed

Wildlife and plant diseases can reduce biodiversity, disrupt ecosystem services and threaten human health. Emerging pathogens have displayed a variety of spatial spread patterns due to differences in host ecology, including diffusive spread from an epicentre (West Nile virus), jump dispersal on a network (foot-and-mouth disease), or a combination of these (Sudden oak death). White-nose syndrome is a highly pathogenic infectious disease of bats currently spreading across North America. Understanding how bat ecology influences this spread is crucial to management of infected and vulnerable populations. Here we show that white-nose syndrome spread is not diffusive but rather mediated by patchily distributed habitat and large-scale gradients in winter climate. Simulations predict rapid expansion and infection of most counties with caves in the contiguous United States by winter 2105-2106. Our findings show the unique pattern of white-nose syndrome spread corresponds to ecological traits of the host and suggest hypotheses for transmission mechanisms acting at the local scale. PMID:23250436

Maher, Sean P; Kramer, Andrew M; Pulliam, J Tomlin; Zokan, Marcus A; Bowden, Sarah E; Barton, Heather D; Magori, Krisztian; Drake, John M

2012-01-01

424

Precursory signals in analysis ensemble spread  

NASA Astrophysics Data System (ADS)

Time evolution of the ensemble spread of an experimental ensemble atmospheric reanalysis ALERA is examined in relation to various meteorological phenomena. The analysis ensemble spread increases about two days prior to westerly bursts in the eastern Indian Ocean. Precursory signals are also found in the monsoon onset. The analysis ensemble spread is large at the leading edge of the Somali jet and it grows as the jet extends eastward. Over Vietnam analysis ensemble spread is maximized several weeks before the maximum of the monsoon westerlies. In the stratosphere the analysis ensemble spread takes the maximum value a few days prior to a sudden warming. Our findings indicate that the ensemble analysis contains additional information on atmospheric uncertainty of scientific interest, which may also have practical value.

Enomoto, Takeshi; Hattori, Miki; Miyoshi, Takemasa; Yamane, Shozo

2010-04-01

425

Pharmacological targeting of spreading depression in migraine  

PubMed Central

Migraine, particularly with aura, is a genetically heterogeneous disorder of ion channels, pumps or transporters associated with increased cortical excitability. Spreading depression, as one reflection of hyperexcitability, is the electrophysiological event underlying aura symptoms and a trigger for headache. Endogenous (e.g., genes and hormones) and exogenous factors (e.g., drugs) modulating migraine susceptibility have also been shown to modulate spreading depression susceptibility concordantly, suggesting that spreading depression can be a relevant therapeutic target in migraine. In support of this, several migraine prophylactic drugs used in clinical practice have been shown to suppress spreading depression susceptibility as a probable mechanism of action, despite belonging to widely different pharmacological classes. Hence, susceptibility to spreading depression can be a useful preclinical model with good positive and negative predictive value for drug screening. PMID:22364328

Eikermann-Haerter, Katharina; Can, Anil; Ayata, Cenk

2012-01-01

426

Estimating Seasonal Drivers in Childhood Infectious Diseases with Continuous Time Models  

E-print Network

Many important factors affect the spread of childhood infectious disease. To understand better the fundamental drivers of infectious disease spread, several researchers have estimated seasonal transmission coefficients using discrete-time models...

Abbott, George H.

2010-07-14

427

Experimental infection of duck origin virulent Newcastle disease virus strain in ducks  

PubMed Central

Background Newcastle disease (ND) caused by virulent Newcastle disease virus (NDV) is an acute, highly contagious and fatal viral disease affecting most species of birds. Ducks are generally considered to be natural reservoirs or carriers of NDV while being resistant to NDV strains, even those most virulent for chickens; however, natural ND cases in ducks have been gradually increasing in recent years. In the present study, ducks of different breeds and ages were experimentally infected with duck origin virulent NDV strain duck/Jiangsu/JSD0812/2008 (JSD0812) by various routes to investigate the pathogenicity of NDV in ducks. Results Six breeds (mallard, Gaoyou, Shaoxing, Jinding, Shanma, and Pekin ducks) were infected intramuscularly (IM) with JSD0812 strain at the dose of 5?×?108 ELD50. Susceptibility to NDV infection among breeds varied, per morbidity and mortality. Mallard ducks were the most susceptible, and Pekin ducks the most resistant. Fifteen-, 30-, 45-, 60-, and 110-day-old Gaoyou ducks were infected with JSD0812 strain at the dose of 5?×?108 ELD50 either IM or intranasally (IN) and intraocularly (IO), and their disease development, viral shedding, and virus tissue distribution were determined. The susceptibility of ducks to NDV infection decreased with age. Most deaths occurred in 15- and 30-day-old ducklings infected IM. Ducks infected IN and IO sometimes exhibited clinical signs, but seldom died. Clinical signs were primarily neurologic. Infected ducks could excrete infectious virus from the pharynx and/or cloaca for a short period, which varied with bird age or inoculation route; the longest period was about 7 days. The rate of virus isolation in tissues from infected ducks was generally low, even in those from dead birds, and it appeared to be unrelated to bird age and infection route. Conclusions The results confirmed that some of the naturally occurring NDV virulent strains can cause the disease in ducks, and that ducks play an important role in the epidemiology of ND. The prevention of NDV spread in ducks should receive more attention and research in terms of preventing the occurrence and prevalence of ND. PMID:25030425

2014-01-01

428

Analysis of the spread of tuberculosis in heterogeneous complex metapopulations  

E-print Network

his paper describes and analyzes the spatial spread of tuberculosis (TB) on complex metapopulation, that is, networks of populations connected by migratory flows whose configurations are described in terms of connectivity distribution of nodes (patches) and the conditional probabilities of connections among classes of nodes sharing the same degree. The migration and transmission processes occur simultaneously. For uncorrelated networks under the assumption of standard incidence transmission, we compute the disease-free equilibrium and the basic reproduction number, and show that the disease-free equilibrium is locally asymptotically stable. Moreover, for uncorrelated networks and under assumption of simple mass action transmission, we give a necessary and sufficient conditions for the instability of the disease-free equilibrium. The existence of endemic equilibria is also discussed. Finally, the prevalence of the TB infection across the metapopulation as a function of the path connectivity is studied using nu...

Tsanou, Berge; Tewa, Jean Jules

2011-01-01

429

Adding Taxol to Initial Chemotherapy May Be New Option When Breast Cancer Has Spread to Lymph Nodes  

Cancer.gov

Early findings from a large, multicenter trial suggest that the drug Taxol (paclitaxel), in combination with other standard chemotherapy agents, may have a small but significant benefit for breast cancer patients whose disease has spread to nearby lymph nodes.

430

Global spread of dengue virus types: mapping the 70 year history  

PubMed Central

Since the first isolation of dengue virus (DENV) in 1943, four types have been identified. Global phenomena such as urbanization and international travel are key factors in facilitating the spread of dengue. Documenting the type-specific record of DENV spread has important implications for understanding patterns in dengue hyperendemicity and disease severity as well as vaccine design and deployment strategies. Existing studies have examined the spread of DENV types at regional or local scales, or described phylogeographic relationships within a single type. Here we summarize the global distribution of confirmed instances of each DENV type from 1943 to 2013 in a series of global maps. These show the worldwide expansion of the types, the expansion of disease hyperendemicity, and the establishment of an increasingly important infectious disease of global public health significance. PMID:24468533

Messina, Jane P.; Brady, Oliver J.; Scott, Thomas W.; Zou, Chenting; Pigott, David M.; Duda, Kirsten A.; Bhatt, Samir; Katzelnick, Leah; Howes, Rosalind E.; Battle, Katherine E.; Simmons, Cameron P.; Hay, Simon I.

2014-01-01

431

Disease concerns in energycane  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diseases may be a limiting factor in the production of energycane, a perennial crop, by reducing annual yields and reducing the longevity of the crop cycle. Disease concerns also include the potential that a compatible pathogen could spread between energycane and sugarcane, sorghum, or corn. Widesp...

432

Natural Human Mobility Patterns and Spatial Spread of Infectious Diseases  

E-print Network

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 ...

Belik, Vitaly

433

Evaluating the Links Between Climate, Disease Spread, and Amphibian Declines  

Microsoft Academic Search

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

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

2008-01-01

434

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

Microsoft Academic Search

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

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

2008-01-01

435

Health care segregation and race disparities in infectious disease: the case of nursing homes and seasonal influenza vaccinations.  

PubMed

Examining nursing home segregation and race disparities in influenza vaccinations, this study demonstrates that segregation may increase both susceptibility and exposure to seasonal flu for black Americans. Evidence based on the 2004 U.S. National Nursing Home Survey shows that individuals in nursing homes with high percentages of black residents have less personal immunity to flu because they are less likely to have been vaccinated against the disease; they may also be more likely to be exposed to flu because more of their coresidents are also unvaccinated. This implies that segregation may generate dual disease hazards for contagious conditions. Segregation appears to limit black Americans' access to personal preventive measures against infection, while spatially concentrating those people who are most likely to become contagious. PMID:22144734

Strully, Kate W

2011-12-01

436

Health Care Segregation and Race Disparities in Infectious Disease: The Case of Nursing Homes and Seasonal Influenza Vaccinations*  

PubMed Central

Examining nursing home segregation and race disparities in influenza vaccinations, this article demonstrates that segregation may increase both susceptibility and exposure to seasonal flu for black Americans. Evidence based on the 2004 U.S. National Nursing Home Survey shows that individuals in nursing homes with a high percentage of black residents have less personal immunity to flu since they are less likely to have been vaccinated against the disease; they may also be more likely to be exposed to flu since more of their co-residents are also unvaccinated. This implies that segregation may generate dual disease hazards for contagious conditions. Segregation appears to limit black Americans’ access to personal preventative measures against infection, while also spatially concentrating those people who are most likely to become contagious. PMID:22144734

Strully, Kate W.

2013-01-01

437

Simulating the effect of quarantine on the spread of the 1918–19 flu in Central Canada  

Microsoft Academic Search

Quarantine is often proposed and sometimes used to control the spread of infectious diseases through a human population. Yet\\u000a there is usually little or no information on the effectiveness of attempting to quarantine humans that is not of an anecdotal\\u000a or conjectural nature. This paper describes how a compartmental model for the geographic spread of infectious diseases can\\u000a be used

Lisa Sattenspiel; D. Ann Herring

2003-01-01

438

Flame Spread Across Liquids: Experimental Results  

NASA Technical Reports Server (NTRS)

The goal of our research on flame spread across a pool of liquid fuel is the quantitative identification of the mechanisms that control the rate and nature of flame spread when the initial temperature of the liquid pool is below the fuel's flash point temperature. Besides numerous experiments in drop towers and 1 g laboratories, we have flown five microgravity (mu-g) experiments on sounding rockets. As described in earlier papers, the first three flights examined the effect of forced opposed airflow over a 2.5 cm deep x 2 cm wide x 30 cm long pool of 1-butanol in mu-g. It was found that the flame spread is much slower and steadier than in 1 g where flame spread has a pulsating character. It was speculated that the flame spread in mu-g resembled the character of pseudo-uniform spread in 1 g; Ito et al later confirmed this conclusively in 1 g experiments. Much of the mu-g flame is also farther from the surface, dimmer, and with less soot, when compared to the 1 g flame. Three-dimensional liquid-phase flow patterns that control the liquid preheating were discovered in both 1 g and mu-g. Our numerical model, restricted to two dimensions, had predicted faster, pulsating flame spread in mu-g for opposed airflow. In examining the differences in the dimensionality of the model and experiment, it was noted that the experiment allowed gas expansion in the lateral direction (across the width of the pool), for which the model could not account. Such lateral expansion could reduce the expansion in the forward and upward directions. Because only these latter directions could be modeled, it was decided to artificially reduce the gas thermal expansion in the predictions. When this was done, satisfactory agreement could be obtained between the predicted and observed spread rates and the steadiness of the spread in microgravity. In 1 g, however, the predicted flame spread character also changed to pseudo-uniform, which disagreed with our 1 g experiments where the spread is pulsating. It was then speculated that gas-phase buoyant flow might oppose the lateral gas expansion, so that the 1 g experiments retained their pulsating flame spread character. If this speculation was valid, a difference in lateral gas expansion should be observable when comparing 1 g and mu-g experiments. Specifically, it was anticipated that greater flow divergence caused by lateral expansion would be measured in mu-g in the absence of a buoyant flow directed towards the flame.

Ross, H. D.; Miller, F. J.

1999-01-01

439

Peristomal Pagetoid Spread of Urothelial Carcinoma of the Ureter  

PubMed Central

Patients with ostomy including urinary stoma often develop peristomal complications, especially skin damage. The patient in this case was a 69-year old female with a history of urothelial carcinoma of the bladder and left ureter who underwent transurethral resection of a bladder tumor, nephroureterectomy and cystectomy combined with ureterocutaneostomy. Later, she had recurrence of urothelial carcinoma in the remaining ureter that spread to the peristomal epidermis, with a skin appearance resembling Paget’s disease. We report this case based on its clinical significance since we believe it is the first description of this condition in the literature. PMID:24179661

Ito, Fumio; Kihara, Ken; Shiomi, Koh; Ishizaki, Sumiko; Tanaka, Masaru; Aiba, Motohiko; Fujibayashi, Mariko; Nakazawa, Hayakazu

2013-01-01

440

[Monkeypox: features of spread after cancellation of mandatory pox immunization].  

PubMed

Features of spread of monkeypox after eradication of smallpox and cancellation of mandatory pox immunization are examined. In the condition of cancellation of mandatory pox immunization, a decrease of population immunity to pox in the population, a lack of vigilance in most of the medical specialists to diseases caused by other pathogenic for human orthopoxviruses was noted. This situation complicates the prognosis of the development of possible outbreaks of infection of humans by monkeypox. In such situation only constant vigilance with respect to this zooanthroponosis, use of express diagnostics methods, as well as means of effective protection will allow to stop outbreaks of monkeypox at the early stages of the development. PMID:22693815

borisevich, S V; Marennikova, S S; Makhla?, A A; Terent'ev, A I; Krasnianski?, V P; Bondarev, V P; Rybak, S I

2012-01-01

441

Modelling the spread of American foulbrood in honeybees  

PubMed Central

We investigate the spread of American foulbrood (AFB), a disease caused by the bacterium Paenibacillus larvae, that affects bees and can be extremely damaging to beehives. Our dataset comes from an inspection period carried out during an AFB epidemic of honeybee colonies on the island of Jersey during the summer of 2010. The data include the number of hives of honeybees, location and owner of honeybee apiaries across the island. We use a spatial SIR model with an underlying owner network to simulate the epidemic and characterize the epidemic using a Markov chain Monte Carlo (MCMC) scheme to determine model parameters and infection times (including undetected ‘occult’ infections). Likely methods of infection spread can be inferred from the analysis, with both distance- and owner-based transmissions being found to contribute to the spread of AFB. The results of the MCMC are corroborated by simulating the epidemic using a stochastic SIR model, resulting in aggregate levels of infection that are comparable to the data. We use this stochastic SIR model to simulate the impact of different control strategies on controlling the epidemic. It is found that earlier inspections result in smaller epidemics and a higher likelihood of AFB extinction. PMID:24026473

Datta, Samik; Bull, James C.; Budge, Giles E.; Keeling, Matt J.

2013-01-01

442

Modelling the spread of American foulbrood in honeybees.  

PubMed

We investigate the spread of American foulbrood (AFB), a disease caused by the bacterium Paenibacillus larvae, that affects bees and can be extremely damaging to beehives. Our dataset comes from an inspection period carried out during an AFB epidemic of honeybee colonies on the island of Jersey during the summer of 2010. The data include the number of hives of honeybees, location and owner of honeybee apiaries across the island. We use a spatial SIR model with an underlying owner network to simulate the epidemic and characterize the epidemic using a Markov chain Monte Carlo (MCMC) scheme to determine model parameters and infection times (including undetected 'occult' infections). Likely methods of infection spread can be inferred from the analysis, with both distance- and owner-based transmissions being found to contribute to the spread of AFB. The results of the MCMC are corroborated by simulating the epidemic using a stochastic SIR model, resulting in aggregate levels of infection that are comparable to the data. We use this stochastic SIR model to simulate the impact of different control strategies on controlling the epidemic. It is found that earlier inspections result in smaller epidemics and a higher likelihood of AFB extinction. PMID:24026473

Datta, Samik; Bull, James C; Budge, Giles E; Keeling, Matt J

2013-11-01

443

Immunization strategy for epidemic spreading on multilayer networks  

NASA Astrophysics Data System (ADS)

In many real-world complex systems, individuals have many kinds of interactions among them, suggesting that it is necessary to consider a layered-structure framework to model systems such as social interactions. This structure can be captured by multilayer networks and can have major effects on the spreading of process that occurs over them, such as epidemics. In this letter we study a targeted immunization strategy for epidemic spreading over a multilayer network. We apply the strategy in one of the layers and study its effect in all layers of the network disregarding degree-degree correlation among layers. We found that the targeted strategy is not as efficient as in isolated networks, due to the fact that in order to stop the spreading of the disease it is necessary to immunize more than 80% of the individuals. However, the size of the epidemic is drastically reduced in the layer where the immunization strategy is applied compared to the case with no mitigation strategy. Thus, the immunization strategy has a major effect on the layer were it is applied, but does not efficiently protect the individuals of other layers.

Buono, C.; Braunstein, L. A.

2015-01-01

444

Exposure of Mongolian gazelles (Procapra gutturosa) to foot and mouth disease virus.  

PubMed

Foot and mouth disease is a highly contagious acute viral disease that affects most ruminant and porcine species. During 2001, 33 serum samples were collected from Mongolian gazelles (Procapra gutturosa) in the Eastern Steppe of Mongolia. Samples were tested for antibodies to seven subtypes of foot-and-mouth-disease virus (FMDV). Antibodies were detected in 67% of the animals, and serologic results indicated exposure to FMDV-O. This virus was present in domestic animal populations in Mongolia from 2000 to 2002, and it is likely that the antibodies to FMDV detected in these gazelles resulted from spillover of virus from domestic animal sources. PMID:16699158

Nyamsuren, D; Joly, Damien O; Enkhtuvshin, S; Odonkhuu, D; Olson, Kirk A; Draisma, Matthys; Karesh, William B

2006-01-01

445

Predictive study on the risk of malaria spreading due to global warming  

SciTech Connect

Global warming will bring about a temperature elevation, and the habitat of vectors of infectious diseases, such as malaria and dengue fever, will spread into subtropical or temperate zone. The purpose of this study is to simulate the spreading of these diseases through reexamination of existing data and collection of some additional information by field survey. From these data, the author will establish the relationship between meteorological conditions, vector density and malaria occurrence. And then he will simulate and predict the malaria epidemics in case of temperature elevation in southeast Asia and Japan.

Ono, Masaji [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan)

1996-12-31

446

Epidemic cholera spreads like wildfire.  

PubMed

Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks. PMID:24424273

Roy, Manojit; Zinck, Richard D; Bouma, Menno J; Pascual, Mercedes

2014-01-01