WorldWideScience

Sample records for worldwide distributed epidemic

  1. Retinopathy of prematurity blindness worldwide: phenotypes in the third epidemic

    Directory of Open Access Journals (Sweden)

    Quinn GE

    2016-05-01

    Full Text Available Graham E Quinn Division of Ophthalmology, The Children’s Hospital of Philadelphia, Wood Center, Philadelphia, PA, USA Abstract: Blindness due to retinopathy of prematurity (ROP is an increasing problem worldwide as improved levels of neonatal care are provided in countries with developing neonatal intensive care units. The occurrence of ROP blindness varies dramatically with the socioeconomic development of a country. In regions with high levels of neonatal care and adequate resources, ROP blindness is largely restricted to premature infants with very low birth weight and low gestational age while in middle- and low-income countries with regional variation in technology and capacity, limited health resources may well limit the care of the premature newborn. Keywords: ROP, international, blindness

  2. Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages

    DEFF Research Database (Denmark)

    Ali, Sajid; Rodriguez Algaba, Julian; Thach, Tine

    2017-01-01

    We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s) or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed...

  3. Worldwide distribution of subaquatic gas hydrates

    Science.gov (United States)

    Kvenvolden, K.A.; Ginsburg, G.D.; Soloviev, V.A.

    1993-01-01

    Sediments containing natural gas hydrates occur worldwide on continental and insular slopes and rises of active and passive margins, on continental shelves of polar regions, and in deep-water (> 300 m) environments of inland lakes and seas. The potential amount of methane in natural gas hydrates is enormous, with current estimates at about 1019 g of methane carbon. Subaquatic gas hydrates have been recovered in 14 different areas of the world, and geophysical and geochemical evidence for them has been found in 33 other areas. The worldwide distribution of natural gas hydrates is updated here; their global importance to the chemical and physical properties of near-surface subaquatic sediments is affirmed. ?? 1993 Springer-Verlag.

  4. Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages

    Science.gov (United States)

    Ali, Sajid; Rodriguez-Algaba, Julian; Thach, Tine; Sørensen, Chris K.; Hansen, Jens G.; Lassen, Poul; Nazari, Kumarse; Hodson, David P.; Justesen, Annemarie F.; Hovmøller, Mogens S.

    2017-01-01

    We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s) or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed that these epidemics were often driven by races from few but highly divergent genetic lineages. PstS1 was predominant in North America; PstS2 in West Asia and North Africa; and both PstS1 and PstS2 in East Africa. PstS4 was prevalent in Northern Europe on triticale; PstS5 and PstS9 were prevalent in Central Asia; whereas PstS6 was prevalent in epidemics in East Africa. PstS7, PstS8 and PstS10 represented three genetic lineages prevalent in Europe. Races from other lineages were in low frequencies. Virulence to Yr9 and Yr27 was common in epidemics in Africa and Asia, while virulence to Yr17 and Yr32 were prevalent in Europe, corresponding to widely deployed resistance genes. The highest diversity was observed in South Asian populations, where frequent recombination has been reported, and no particular race was predominant in this area. The results are discussed in light of the role of invasions in shaping pathogen population across geographical regions. The results emphasized the lack of predictability of emergence of new races with high epidemic potential, which stresses the need for additional investments in population biology and surveillance activities of pathogens on global food crops, and assessments of disease vulnerability of host varieties prior to their deployment at larger scales. PMID:28676811

  5. Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages

    Directory of Open Access Journals (Sweden)

    Sajid Ali

    2017-06-01

    Full Text Available We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed that these epidemics were often driven by races from few but highly divergent genetic lineages. PstS1 was predominant in North America; PstS2 in West Asia and North Africa; and both PstS1 and PstS2 in East Africa. PstS4 was prevalent in Northern Europe on triticale; PstS5 and PstS9 were prevalent in Central Asia; whereas PstS6 was prevalent in epidemics in East Africa. PstS7, PstS8 and PstS10 represented three genetic lineages prevalent in Europe. Races from other lineages were in low frequencies. Virulence to Yr9 and Yr27 was common in epidemics in Africa and Asia, while virulence to Yr17 and Yr32 were prevalent in Europe, corresponding to widely deployed resistance genes. The highest diversity was observed in South Asian populations, where frequent recombination has been reported, and no particular race was predominant in this area. The results are discussed in light of the role of invasions in shaping pathogen population across geographical regions. The results emphasized the lack of predictability of emergence of new races with high epidemic potential, which stresses the need for additional investments in population biology and surveillance activities of pathogens on global food crops, and assessments of disease vulnerability of host varieties prior to their deployment at larger scales.

  6. Evidence that dirty electricity is causing the worldwide epidemics of obesity and diabetes.

    Science.gov (United States)

    Milham, Samuel

    2014-01-01

    The epidemics of obesity and diabetes most apparent in recent years had their origins with Thomas Edison's development of distributed electricity in New York City in 1882. His original direct current (DC) generators suffered serious commutator brush arcing which is a major source of high-frequency voltage transients (dirty electricity). From the onset of the electrical grid, electrified populations have been exposed to dirty electricity. Diesel generator sets are a major source of dirty electricity today and are used almost universally to electrify small islands and places unreachable by the conventional electric grid. This accounts for the fact that diabetes prevalence, fasting plasma glucose and obesity are highest on small islands and other places electrified by generator sets and lowest in places with low levels of electrification like sub-Saharan Africa and east and Southeast Asia.

  7. Histologic distribution of borderline ovarian tumors worldwide: a systematic review

    OpenAIRE

    Song, Taejong; Lee, Yoo-Young; Choi, Chel Hun; Kim, Tae-Joong; Lee, Jeong-Won; Bae, Duk-Soo; Kim, Byoung-Gie

    2013-01-01

    Objective The histologic types of borderline ovarian tumors (BOTs) exhibit striking differences in clinical behavior and prognosis. Yet, there is no information available on the histologic distribution of BOTs according to geographic region. The purpose of this study was to systematically review this issue worldwide. Methods A comprehensive search of the literature was conducted using electronic databases. Studies were eligible if BOTs were investigated and the histologic distribution of the ...

  8. Histologic distribution of borderline ovarian tumors worldwide: a systematic review.

    Science.gov (United States)

    Song, Taejong; Lee, Yoo-Young; Choi, Chel Hun; Kim, Tae-Joong; Lee, Jeong-Won; Bae, Duk-Soo; Kim, Byoung-Gie

    2013-01-01

    The histologic types of borderline ovarian tumors (BOTs) exhibit striking differences in clinical behavior and prognosis. Yet, there is no information available on the histologic distribution of BOTs according to geographic region. The purpose of this study was to systematically review this issue worldwide. A comprehensive search of the literature was conducted using electronic databases. Studies were eligible if BOTs were investigated and the histologic distribution of the data was shown. The studies were grouped by geographic region and totaled by country. Of 487 potentially relevant studies, 51 met our inclusion criteria, as follows: 8 studies from North America (2 countries); 26 studies from Europe (14 countries); 7 studies from the Middle East (3 countries); and 10 studies from East Asia (5 countries). The histologic distribution of BOTs was considerably different in different parts of the world, but follows specific patterns. In general, serous-type BOTs were the predominantly identified histology in North America, the Middle East, and Europe, while mucinous-type BOTs predominated in East Asia. Significant geographic variation is evident among BOT histology in different parts of the world. More research is needed to understand this phenomenon.

  9. Worldwide Phylogenetic Distributions and Population Dynamics of the Genus Histoplasma.

    Science.gov (United States)

    Teixeira, Marcus de M; Patané, José S L; Taylor, Maria L; Gómez, Beatriz L; Theodoro, Raquel C; de Hoog, Sybren; Engelthaler, David M; Zancopé-Oliveira, Rosely M; Felipe, Maria S S; Barker, Bridget M

    2016-06-01

    Histoplasma capsulatum comprises a worldwide complex of saprobiotic fungi mainly found in nitrogen/phosphate (often bird guano) enriched soils. The microconidia of Histoplasma species may be inhaled by mammalian hosts, and is followed by a rapid conversion to yeast that can persist in host tissues causing histoplasmosis, a deep pulmonary/systemic mycosis. Histoplasma capsulatum sensu lato is a complex of at least eight clades geographically distributed as follows: Australia, Netherlands, Eurasia, North American classes 1 and 2 (NAm 1 and NAm 2), Latin American groups A and B (LAm A and LAm B) and Africa. With the exception of the Eurasian cluster, those clades are considered phylogenetic species. Increased Histoplasma sampling (n = 234) resulted in the revision of the phylogenetic distribution and population structure using 1,563 aligned nucleotides from four protein-coding regions. The LAm B clade appears to be divided into at least two highly supported clades, which are geographically restricted to either Colombia/Argentina or Brazil respectively. Moreover, a complex population genetic structure was identified within LAm A clade supporting multiple monophylogenetic species, which could be driven by rapid host or environmental adaptation (~0.5 MYA). We found two divergent clades, which include Latin American isolates (newly named as LAm A1 and LAm A2), harboring a cryptic cluster in association with bats. At least six new phylogenetic species are proposed in the Histoplasma species complex supported by different phylogenetic and population genetics methods, comprising LAm A1, LAm A2, LAm B1, LAm B2, RJ and BAC-1 phylogenetic species. The genetic isolation of Histoplasma could be a result of differential dispersion potential of naturally infected bats and other mammals. In addition, the present study guides isolate selection for future population genomics and genome wide association studies in this important pathogen complex.

  10. Molecular epidemiology and emergence of worldwide epidemic clones of Neisseria meningitidis in Taiwan

    Directory of Open Access Journals (Sweden)

    Chang Hsiu-Li

    2006-02-01

    Full Text Available Abstract Background Meningococcal disease is infrequently found in Taiwan, a country with 23 million people. Between 1996 and 2002, 17 to 81 clinical cases of the disease were reported annually. Reported cases dramatically increased in 2001–2002. Our record shows that only serogroup B and W135 meningococci have been isolated from patients with meningococcal disease until 2000. However, serogroup A, C and Y meningococci were detected for the first time in 2001 and continued to cause disease through 2002. Most of serogroup Y meningococcus infections localized in Central Taiwan in 2001, indicating that a small-scale outbreak of meningococcal disease had occurred. The occurrence of a meningococcal disease outbreak and the emergence of new meningococcal strains are of public health concern. Methods Neisseria meningitidis isolates from patients with meningococcal disease from 1996 to 2002 were collected and characterized by serogrouping, pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. The genetic relatedness and clonal relationship between the isolates were analyzed by using the PFGE patterns and the allelic profiles of the sequence types (STs. Results Serogroups A, B, C, W135, Y, and non-serogroupable Neisseria meningitidis were, respectively, responsible for 2%, 50%, 2%, 35%, 9%, and 2% of 158 culture-confirmed cases of meningococcal disease in 1996–2002. Among 100 N. meningitidis isolates available for PFGE and MLST analyses, 51 different PFGE patterns and 30 STs were identified with discriminatory indices of 0.95 and 0.87, respectively. Of the 30 STs, 21 were newly identified and of which 19 were found in serogroup B isolates. A total of 40 PFGE patterns were identified in 52 serogroup B isolates with the patterns distributed over several distinct clusters. In contrast, the isolates within each of the serogroups A, C, W135, and Y shared high levels of PFGE pattern similarity. Analysis of the allelic profile of the

  11. Object Distribution Networks for World-wide Document Circulation

    NARCIS (Netherlands)

    Lijding, M.E.M.; Righetti, Claudio E.; Moldes, Leandro Navarro

    1997-01-01

    This paper presents an Object Distribution System (ODS), a distributed system inspired by the ultra-large scale distribution models used in everyday life (e.g. food or newspapers distribution chains). Beyond traditional mechanisms of approaching information to readers (e.g. caching and mirroring),

  12. Distributive justice and the harm to medical professionals fighting epidemics

    DEFF Research Database (Denmark)

    Albertsen, Andreas Brøgger; Thaysen, Jens Damgaard

    2017-01-01

    , cure and care for the vulnerable, luck egalitarianism seems to imply that their claim of justice to medical attention in case of infection is weak or non-existent. The article demonstrates how a recent interpretation of luck egalitarianism offers a solution to this problem. Redefining luck......The exposure of doctors, nurses and other medical professionals to risks in the context of epidemics is significant. While traditional medical ethics offers the thought that these dangers may limit the extent to which a duty to care is applicable in such situations, it has less to say about what we...... might owe to medical professionals who are disadvantaged in these contexts. Luck egalitarianism, a responsibility-sensitive theory of distributive justice, appears to fare particularly badly in that regard. If we want to maintain that medical professionals are responsible for their decisions to help...

  13. Distribution and dynamics of epidemic and pandemic Vibrio parahaemolyticus virulence factors

    Directory of Open Access Journals (Sweden)

    Daniela eCeccarelli

    2013-12-01

    Full Text Available Vibrio parahaemolyticus, autochthonous to estuarine, marine, and coastal environments throughout the world, is the causative agent of food-borne gastroenteritis. More than 80 serotypes have been described worldwide, based on antigenic properties of the somatic (O and capsular (K antigens. Serovar O3:K6 emerged in India in 1996 and subsequently was isolated worldwide, leading to the conclusion that the first V. parahaemolyticus pandemic had taken place. Most strains of V. parahaemolyticus isolated from the environment or seafood, in contrast to clinical strains, do not produce a thermostable direct hemolysin (TDH and/or a TDH-related hemolysin (TRH. Type 3 secretion systems (T3SSs, needle-like apparatuses able to deliver bacterial effectors into host cytoplasm, were identified as triggering cytotoxicity and enterotoxicity. Type 6 secretion systems (T6SS predicted to be involved in intracellular trafficking and vesicular transport appear to play a role in V. parahaemolyticus virulence. Recent advances in V. parahaemolyticus genomics identified several pathogenicity islands (VpaIs located on either chromosome in both epidemic and pandemic strains and comprising additional colonization factors, such as restriction-modification complexes, chemotaxis proteins, classical bacterial surface virulence factors, and putative colicins. Furthermore, studies indicate strains lacking toxins and genomic regions associated with pathogenicity may also be pathogenic, suggesting other important virulence factors remain to be identified. The unique repertoire of virulence factors identified to date, their occurrence and distribution in both epidemic and pandemic strains worldwide are described, with the aim of highlighting the complexity of V. parahaemolyticus pathogenicity as well as its dynamic genome.

  14. Global Analysis for a Delay-Distributed SIR Epidemic Model

    Directory of Open Access Journals (Sweden)

    Kaddar Abdelilah

    2013-05-01

    Full Text Available One of the most tools for describing the incubation period in the epidemiological dynamic models is the distributed delays. In this paper, we propose a delay-distributed SIR epidemic model with a nonlinear incidence rate. Using the Lyapunov theory and LaSalle’s principle, we show the global asymptotic stability of the disease-free and the endemic equilibria. This analysis extends and performs existing results. En épidémiologie le retard joue un rôle très important dans la représentation de la période d’incubation. Dans ce travail, nous étudions un modèle SIR à retard distribué, avec une fonction d’incidence non linéaire. Pour analyser la stabilité globale du point d’équilibre sans maladie et du point d’équilibre endémique, nous utilisons la théorie de Lyapunov et le principe d’invariance de LaSalle.

  15. The leading digit distribution of the worldwide Illicit Financial Flows

    OpenAIRE

    Tariq Ahmad Mir

    2012-01-01

    Benford's law states that in data sets from different phenomena leading digits tend to be distributed logarithmically such that the numbers beginning with smaller digits occur more often than those with larger ones. Particularly, the law is known to hold for different types of financial data. The Illicit Financial Flows (IFFs) exiting the developing countries are frequently discussed as hidden resources which could have been otherwise properly utilized for their development. We investigate he...

  16. Distributed Monitoring Infrastructure for Worldwide LHC Computing Grid

    CERN Document Server

    Andrade, Pedro; Bhatt, Kislay; Chand, Phool; Collados, David; Duggal, Vibhuti; Fuente, Paloma; Hayashi, Soichi; Imamagic, Emir; Joshi, Pradyumna; Kalmady, Rajesh; Karnani, Urvashi; Kumar, Vaibhav; Lapka, Wojciech; Quick, Robert; Tarragon, Jacobo; Teige, Scott; Triantafyllidis, Christos

    2012-01-01

    The journey of a monitoring probe from its development phase to the moment its execution result is presented in an availability report is a complex process. It goes through multiple phases such as development, testing, integration, release, deployment, execution, data aggregation, computation, and reporting. Further, it involves people with different roles (developers, site managers, VO managers, service managers, management), from different middleware providers (ARC, dCache, gLite, UNICORE and VDT), consortiums (WLCG, EMI, EGI, OSG), and operational teams (GOC, OMB, OTAG, CSIRT). The seamless harmonization of these distributed actors is in daily use for monitoring of the WLCG infrastructure. In this paper we describe the monitoring of the WLCG infrastructure from the operational perspective. We explain the complexity of the journey of a monitoring probe from its execution on a grid node to the visualization on the MyWLCG portal where it is exposed to other clients. This monitoring workflow profits from the i...

  17. Distributive justice and the harm to medical professionals fighting epidemics

    DEFF Research Database (Denmark)

    Albertsen, Andreas; Thaysen, Jens Damgaard

    2017-01-01

    The exposure of doctors, nurses and other medical professionals to risks in the context of epidemics is significant. While traditional medical ethics offers the thought that these dangers may limit the extent to which a duty to care is applicable in such situations, it has less to say about what ...

  18. Dynamic Medical Material Distribution Model Based on Epidemic Diffusion Rule and Clustering Approach

    Directory of Open Access Journals (Sweden)

    Wu Guangmin

    2015-01-01

    Full Text Available Due to the fact that the dynamic medical material distribution is vital to the quick response to urgent demand when the Ebola virus occurs, the optimal distribution approach is explored according to the Ebola virus diffusion rule and different severity of the epidemic. First, we choose the more serious epidemic state of Sierra Leone in West Africa as the research object and the SIQR (susceptible, infected, quarantined, required epidemic model with pulse vaccination is introduced to describe the Ebola diffusion rule and obtain the demanded vaccine and drug in each pulse. Based on the SIQR model, thirteen areas in Sierra Leone are classified into three emergency levels by clustering analysis. Then a dynamic medical material distribution model is formulated, with goals of both reducing the transportation cost and shortages. The results indicate that the proposed approach can make an outstanding contribution to fight against the Ebola virus.

  19. Equal Distribution Model of Epidemic Drugs Based on a Cellular Automata Model

    Directory of Open Access Journals (Sweden)

    Huang Xinyi

    2015-01-01

    Full Text Available The epidemic spreading of infectious disease is a process of evolution over time. Based on the cellular automata model[1], this paper analyzes the epidemic spreading rules, and establishes an efficient equal distribution model of drugs in a broad sense. For multiple regions, in case of demand of drugs exceeding supply, the drugs shall be distributed according to the proportion of a total number of people in each region, the number of patients, the number of the isolated, and the number of deaths. It is necessary to simulate based on these four schemes to obtain simulation results. The results show that, when the drugs are distributed by the proportion of the number of deaths, it is optimal for controlling over epidemic situations.

  20. Impact of the Infection Period Distribution on the Epidemic Spread in a Metapopulation Model

    Science.gov (United States)

    Vergu, Elisabeta; Busson, Henri; Ezanno, Pauline

    2010-01-01

    Epidemic models usually rely on the assumption of exponentially distributed sojourn times in infectious states. This is sometimes an acceptable approximation, but it is generally not realistic and it may influence the epidemic dynamics as it has already been shown in one population. Here, we explore the consequences of choosing constant or gamma-distributed infectious periods in a metapopulation context. For two coupled populations, we show that the probability of generating no secondary infections is the largest for most parameter values if the infectious period follows an exponential distribution, and we identify special cases where, inversely, the infection is more prone to extinction in early phases for constant infection durations. The impact of the infection duration distribution on the epidemic dynamics of many connected populations is studied by simulation and sensitivity analysis, taking into account the potential interactions with other factors. The analysis based on the average nonextinct epidemic trajectories shows that their sensitivity to the assumption on the infectious period distribution mostly depends on , the mean infection duration and the network structure. This study shows that the effect of assuming exponential distribution for infection periods instead of more realistic distributions varies with respect to the output of interest and to other factors. Ultimately it highlights the risk of misleading recommendations based on modelling results when models including exponential infection durations are used for practical purposes. PMID:20195473

  1. Discrete epidemic models with arbitrary stage distributions and applications to disease control.

    Science.gov (United States)

    Hernandez-Ceron, Nancy; Feng, Zhilan; Castillo-Chavez, Carlos

    2013-10-01

    W.O. Kermack and A.G. McKendrick introduced in their fundamental paper, A Contribution to the Mathematical Theory of Epidemics, published in 1927, a deterministic model that captured the qualitative dynamic behavior of single infectious disease outbreaks. A Kermack–McKendrick discrete-time general framework, motivated by the emergence of a multitude of models used to forecast the dynamics of epidemics, is introduced in this manuscript. Results that allow us to measure quantitatively the role of classical and general distributions on disease dynamics are presented. The case of the geometric distribution is used to evaluate the impact of waiting-time distributions on epidemiological processes or public health interventions. In short, the geometric distribution is used to set up the baseline or null epidemiological model used to test the relevance of realistic stage-period distribution on the dynamics of single epidemic outbreaks. A final size relationship involving the control reproduction number, a function of transmission parameters and the means of distributions used to model disease or intervention control measures, is computed. Model results and simulations highlight the inconsistencies in forecasting that emerge from the use of specific parametric distributions. Examples, using the geometric, Poisson and binomial distributions, are used to highlight the impact of the choices made in quantifying the risk posed by single outbreaks and the relative importance of various control measures.

  2. Persistence and distribution of a stochastic susceptible-infected-removed epidemic model with varying population size

    Science.gov (United States)

    Chen, Lihong; Wei, Fengying

    2017-10-01

    In this paper, the dynamics of a stochastic susceptible-infected-removed model in a population with varying size is investigated. We firstly show that the stochastic epidemic model has a unique global positive solution with any positive initial value. Then we verify that random perturbations lead to extinction when some conditions are being valid. Moreover, we prove that the solution of the stochastic epidemic model is persistent in the mean by building up a suitable Lyapunov function and using generalized Itô's formula. Further, the stochastic epidemic model admits a stationary distribution around the endemic equilibrium when parameters satisfy some sufficient conditions. To end this contribution and to check the validity of the main results, numerical simulations are separately carried out to illustrate these results.

  3. Epidemic threshold determined by the first moments of network with alternating degree distributions

    Science.gov (United States)

    Li, Kezan; Zhang, Haifeng; Fu, Xinchu; Ding, Yong; Small, Michael

    2015-02-01

    During the alternating day-night cycle, people have differing behavior and hence different connection patterns-such as going to work or home, shopping and so on. Hence, the true topological structure of human contact networks are not only time-varying but also exhibit certain distribution regularity. In this paper, we will investigate epidemic spreading on time-varying human contact networks, which follow one degree distribution during daytime, but another at night. Based on SIS (susceptible/infected/susceptible) propagation mechanism, we study the epidemic threshold of this network with alternating distributions. A surprising result is that for the discrete-time case the epidemic threshold is determined only by the first moments of the two alternating degree distributions, if the degree of each node is constant for all nights. A similar result is valid for the continuous-time case if the duration is sufficiently small. This work shows that the spreading dynamics of time-varying networks with alternating distributions is completely different from the widely studied case of static spreading networks.

  4. The histology of ovarian cancer: worldwide distribution and implications for international survival comparisons (CONCORD-2).

    Science.gov (United States)

    Matz, Melissa; Coleman, Michel P; Sant, Milena; Chirlaque, Maria Dolores; Visser, Otto; Gore, Martin; Allemani, Claudia

    2017-02-01

    Ovarian cancers comprise several histologically distinct tumour groups with widely different prognosis. We aimed to describe the worldwide distribution of ovarian cancer histology and to understand what role this may play in international variation in survival. The CONCORD programme is the largest population-based study of global trends in cancer survival. Data on 681,759 women diagnosed during 1995-2009 with cancer of the ovary, fallopian tube, peritoneum and retroperitonum in 51 countries were included. We categorised ovarian tumours into six histological groups, and explored the worldwide distribution of histology. During 2005-2009, type II epithelial tumours were the most common. The proportion was much higher in Oceania (73.1%), North America (73.0%) and Europe (72.6%) than in Central and South America (65.7%) and Asia (56.1%). By contrast, type I epithelial tumours were more common in Asia (32.5%), compared with only 19.4% in North America. From 1995 to 2009, the proportion of type II epithelial tumours increased from 68.6% to 71.1%, while the proportion of type I epithelial tumours fell from 23.8% to 21.2%. The proportions of germ cell tumours, sex cord-stromal tumours, other specific non-epithelial tumours and tumours of non-specific morphology all remained stable over time. The distribution of ovarian cancer histology varies widely worldwide. Type I epithelial, germ cell and sex cord-stromal tumours are generally associated with higher survival than type II tumours, so the proportion of these tumours may influence survival estimates for all ovarian cancers combined. The distribution of histological groups should be considered when comparing survival between countries and regions. Copyright © 2016. Published by Elsevier Inc.

  5. Effects of epidemic diseases on the distribution of bonobos.

    Science.gov (United States)

    Inogwabini, Bila-Isia; Leader-Williams, Nigel

    2012-01-01

    This study examined how outbreaks and the occurrence of Anthrax, Ebola, Monkeypox and Trypanosomiasis may differentially affect the distribution of bonobos (Pan paniscus). Using a combination of mapping, Jaccard overlapping coefficients and binary regressions, the study determined how each disease correlated with the extent of occurrence of, and the areas occupied by, bonobos. Anthrax has only been reported to occur outside the range of bonobos and so was not considered further. Ebola, Monkeypox and Trypanosomiasis were each reported within the area of occupancy of bonobos. Their respective overlap coefficients were: J = 0.10; Q(α = 0.05) = 2.00 (odds ratios = 0.0001, 95% CI = 0.0057; Z = -19.41, significant) for Ebola; J = 1.00; Q(α = 0.05) = 24.0 (odds ratios = 1.504, 95% CI = 0.5066-2.6122) for Monkeypox; and, J = 0.33; Q(α = 0.05) = 11.5 (Z = 1.14, significant) for Trypanosomiasis. There were significant relationships for the presence and absence of Monkeypox and Trypanosomiasis and the known extent of occurrence of bonobos, based on the equations y = 0.2368Ln(x)+0.8006 (R(2) = 0.9772) and y = -0.2942Ln(x)+0.7155 (R(2) = 0.698), respectively. The positive relationship suggested that bonobos tolerated the presence of Monkeypox. In contrast, the significant negative coefficient suggested that bonobos were absent in areas where Trypanosomiasis is endemic. Our results suggest that large rivers may have prevented Ebola from spreading into the range of bonobos. Meanwhile, Trypanosomiasis has been recorded among humans within the area of occurrence of bonobos, and appears the most important disease in shaping the area of occupancy of bonobos within their overall extent of occupancy.

  6. Effects of epidemic diseases on the distribution of bonobos.

    Directory of Open Access Journals (Sweden)

    Bila-Isia Inogwabini

    Full Text Available This study examined how outbreaks and the occurrence of Anthrax, Ebola, Monkeypox and Trypanosomiasis may differentially affect the distribution of bonobos (Pan paniscus. Using a combination of mapping, Jaccard overlapping coefficients and binary regressions, the study determined how each disease correlated with the extent of occurrence of, and the areas occupied by, bonobos. Anthrax has only been reported to occur outside the range of bonobos and so was not considered further. Ebola, Monkeypox and Trypanosomiasis were each reported within the area of occupancy of bonobos. Their respective overlap coefficients were: J = 0.10; Q(α = 0.05 = 2.00 (odds ratios = 0.0001, 95% CI = 0.0057; Z = -19.41, significant for Ebola; J = 1.00; Q(α = 0.05 = 24.0 (odds ratios = 1.504, 95% CI = 0.5066-2.6122 for Monkeypox; and, J = 0.33; Q(α = 0.05 = 11.5 (Z = 1.14, significant for Trypanosomiasis. There were significant relationships for the presence and absence of Monkeypox and Trypanosomiasis and the known extent of occurrence of bonobos, based on the equations y = 0.2368Ln(x+0.8006 (R(2 = 0.9772 and y = -0.2942Ln(x+0.7155 (R(2 = 0.698, respectively. The positive relationship suggested that bonobos tolerated the presence of Monkeypox. In contrast, the significant negative coefficient suggested that bonobos were absent in areas where Trypanosomiasis is endemic. Our results suggest that large rivers may have prevented Ebola from spreading into the range of bonobos. Meanwhile, Trypanosomiasis has been recorded among humans within the area of occurrence of bonobos, and appears the most important disease in shaping the area of occupancy of bonobos within their overall extent of occupancy.

  7. Discrete epidemic models with arbitrary stage distributions and applications to disease control

    Science.gov (United States)

    Hernandez-Ceron, Nancy; Feng, Zhilan; Castillo-Chavez, Carlos

    2014-01-01

    W. O. Kermack and A. G. McKendrick introduced in their fundamental paper, A Contribution to the Mathematical Theory of Epidemics, published in 1927, a simple deterministic model that captured the qualitative dynamic behavior of single infectious disease outbreaks. A Kermack-McKendrick discrete-time general framework, motivated by the emergence of a multitude of models used to forecast the dynamics of SARS and influenza outbreaks, is introduced in this manuscript. Results that allow us to measure quantitatively the role of classical and general distributions on disease dynamics are presented. The case of the geometric distribution is used to evaluate the impact of waiting-time distributions on epidemiological processes or public health interventions. In short, the geometric distribution is used to set up the baseline or null epidemiological model used to test the relevance of realistic stage-period distribution on the dynamics of single epidemic outbreaks. A final size relationship involving the control reproduction number, a function of transmission parameters and the means of distributions used to model disease or intervention control measures, is computed. Model results and simulations highlight the inconsistencies in forecasting that emerge from the use of specific parametric distributions. Examples, using the geometric, Poisson and binomial distributions, are used to highlight the impact of the choices made in quantifying the risk posed by single outbreaks and the relative importance of various control measures. PMID:23797790

  8. Periodic solution and stationary distribution of stochastic SIR epidemic models with higher order perturbation

    Science.gov (United States)

    Liu, Qun; Jiang, Daqing; Hayat, Tasawar; Ahmad, Bashir

    2017-09-01

    In this paper, we investigate two stochastic SIR epidemic models with higher order perturbation. For the nonautonomous periodic case of the model, by using Has'minskii's theory of periodic solution, we show that the system has at least one nontrivial positive T-periodic solution. For the system disturbed by both the white noise and telephone noise, we establish sufficient conditions for positive recurrence and the existence of ergodic stationary distribution of the positive solution.

  9. Worldwide distribution of NAT2 diversity: Implications for NAT2 evolutionary history

    Directory of Open Access Journals (Sweden)

    Gérard Nathalie

    2008-02-01

    Full Text Available Abstract Background The N-acetyltransferase 2 (NAT2 gene plays a crucial role in the metabolism of many drugs and xenobiotics. As it represents a likely target of population-specific selection pressures, we fully sequenced the NAT2 coding region in 97 Mandenka individuals from Senegal, and compared these sequences to extant data on other African populations. The Mandenka data were further included in a worldwide dataset composed of 41 published population samples (6,727 individuals from four continental regions that were adequately genotyped for all common NAT2 variants so as to provide further insights into the worldwide haplotype diversity and population structure at NAT2. Results The sequencing analysis of the NAT2 gene in the Mandenka sample revealed twelve polymorphic sites in the coding exon (two of which are newly identified mutations, C345T and C638T, defining 16 haplotypes. High diversity and no molecular signal of departure from neutrality were observed in this West African sample. On the basis of the worldwide genotyping survey dataset, we found a strong genetic structure differentiating East Asians from both Europeans and sub-Saharan Africans. This pattern could result from region- or population-specific selective pressures acting at this locus, as further suggested in the HapMap data by extremely high values of FST for a few SNPs positions in the NAT2 coding exon (T341C, C481T and A803G in comparison to the empirical distribution of FST values accross the whole 400-kb region of the NAT gene family. Conclusion Patterns of sequence variation at NAT2 are consistent with selective neutrality in all sub-Saharan African populations investigated, whereas the high level of population differentiation between Europeans and East Asians inferred from SNPs could suggest population-specific selective pressures acting at this locus, probably caused by differences in diet or exposure to other environmental signals.

  10. Addressing population heterogeneity and distribution in epidemics models using a cellular automata approach.

    Science.gov (United States)

    López, Leonardo; Burguerner, Germán; Giovanini, Leonardo

    2014-04-12

    The spread of an infectious disease is determined by biological and social factors. Models based on cellular automata are adequate to describe such natural systems consisting of a massive collection of simple interacting objects. They characterize the time evolution of the global system as the emergent behaviour resulting from the interaction of the objects, whose behaviour is defined through a set of simple rules that encode the individual behaviour and the transmission dynamic. An epidemic is characterized trough an individual-based-model built upon cellular automata. In the proposed model, each individual of the population is represented by a cell of the automata. This way of modeling an epidemic situation allows to individually define the characteristic of each individual, establish different scenarios and implement control strategies. A cellular automata model to study the time evolution of a heterogeneous populations through the various stages of disease was proposed, allowing the inclusion of individual heterogeneity, geographical characteristics and social factors that determine the dynamic of the desease. Different assumptions made to built the classical model were evaluated, leading to following results: i) for low contact rate (like in quarantine process or low density population areas) the number of infective individuals is lower than other areas where the contact rate is higher, and ii) for different initial spacial distributions of infected individuals different epidemic dynamics are obtained due to its influence on the transition rate and the reproductive ratio of disease. The contact rate and spatial distributions have a central role in the spread of a disease. For low density populations the spread is very low and the number of infected individuals is lower than in highly populated areas. The spacial distribution of the population and the disease focus as well as the geographical characteristic of the area play a central role in the dynamics of the

  11. Origin and evolution of the worldwide distributed pathogenic amoeboflagellate Naegleria fowleri.

    Science.gov (United States)

    De Jonckheere, Johan F

    2011-10-01

    Naegleria fowleri, a worldwide distributed pathogen, is the causative agent of primary amoebic meningoencephalitis. Because it is such a fulminant disease, most patients do not survive the infection. This pathogen is a free-living amoeboflagellate present in warm water. To date, it is well established that there are several types of N. fowleri, which can be distinguished based on the length of the internal transcribed spacer 1 and a one bp transition in the 5.8S rDNA. Seven of the eight known types have been detected in Europe. Three types are present in the USA, of which one is unique to this country. Only one of the eight types occurs in Oceania (Australia and New Zealand) and Japan. In mainland Asia (India, China and Thailand) the two most common types are found, which are also present in Europe and the USA. There is strong indication that the pathogenic N. fowleri evolved from the nonpathogenic Naegleria lovaniensis on the American continent. There is no evidence of virulence differences between the types of N. fowleri. Two other Naegleria spp. are pathogenic for mice, but human infections due to these two other Naegleria spp. are not known. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. World-wide species distributions in the family Kyphosidae (Teleostei: Perciformes).

    Science.gov (United States)

    Knudsen, Steen Wilhelm; Clements, Kendall D

    2016-08-01

    Sea chubs of the family Kyphosidae are major consumers of macroalgae on both temperate and tropical reefs, where they can comprise a significant proportion of fish biomass. However, the relationships and taxonomic status of sea chubs (including the junior synonyms Hermosilla, Kyphosus, Neoscorpis and Sectator) worldwide have long been problematical due to perceived lack of character differentiation, complicating ecological assessment. More recently, the situation has been further complicated by publication of conflicting taxonomic treatments. Here, we resolve the relationships, taxonomy and distribution of all known species of sea chubs through a combined analysis of partial fragments from mitochondrial markers (12s, 16s, cytb, tRNA -Pro, -Phe, -Thr and -Val) and three nuclear markers (rag1, rag2, tmo4c4). These new results provide independent evidence for the presence of several junior synonyms among Atlantic and Indo-Pacific taxa, demonstrating that several sea chub species are more widespread than previously thought. In particular, our results can reject the hypothesis of endemic species in the Atlantic Ocean. At a higher taxonomic level, our results shed light on the relationships between Girellidae, Kuhliidae, Kyphosidae, Microcanthidae, Oplegnathidae and Scorpididae, with Scorpididae resolved as the sister group to Kyphosidae. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Distribution, characteristics, and worldwide inventory of dioxins in kaolin ball clays.

    Science.gov (United States)

    Horii, Yuichi; Ohtsuka, Nobutoshi; Minomo, Kotaro; Nojiri, Kiyoshi; Kannan, Kurunthachalam; Lam, Paul K S; Yamashita, Nobuyoshi

    2011-09-01

    Distribution, characteristics, and global inventory of dioxins (polychlorinated dibenzo-p-dioxins [PCDDs] and dibenzofurans [PCDFs] and dioxin like polychlorinated biphenyls) in kaolin clays collected from 10 countries were investigated. Dioxins were found in all kaolin clay samples analyzed, at total concentrations ranging from 1.2 pg/g (Brazil) to 520,000 pg/g (USA). Dioxin concentrations in kaolin clays from a few countries (e.g., Brazil and UK) were lower than those reported for background soils in Japan. Dioxin profiles in kaolin clays were characterized by the domination of the congener octachlorodibenzo-p-dioxin (OCDD), and the concentrations of other congeners decreased in the order of reduction in the levels of chlorination. Furthermore, specific distribution of congeners, with predominant proportions of 1,4,6,9-substituted PCDDs within each homologue group, was found in most clay samples. The ratios of concentrations of PCDD to PCDF and 1,2,3,7,8,9-HxCDD to 1,2,3,6,7,8-HxCDD indicated differences in the profiles found for anthropogenic sources (including pentachlorophenol) and kaolin clays. Concentrations of PCDD/Fs in kaolin clays, except for American ball clays, did not exceed the environmental criteria set by the Law Concerning Special Measures against Dioxins in Japan. Based on the average concentrations measured in our study, inventories of PCDD/Fs from the production/usage of ball clays on a global scale were estimated to be 650 kg/yr; the corresponding value on a TEQ basis is 2400 g-TEQ/yr. More than 480 kg of OCDD is estimated to be released annually from the production of kaolin clays worldwide, suggesting that kaolin clays can be a major contributor for additional source of dioxins, especially OCDD, in the environment.

  14. Worldwide distribution of non–native Amazon parrots and temporal trends of their global trade

    Directory of Open Access Journals (Sweden)

    Mori, E.

    2017-01-01

    Full Text Available Alien species are the second leading cause of the global biodiversity crisis, after habitat loss and fragmentation. Popular pet species, such as parrots and parakeets (Aves, Psittaciformes, are often introduced outside their native range as a result of the pet trade. On escape from captivity, some such species, such as the ring–necked parakeet and the monk parakeet, are highly invasive and successfully compete with native species. Populations of Amazon parrots (Amazona spp. can be found throughout the world, but data on their status, distribution and impact are incomplete. We gathered and reviewed the available information concerning global trade, distribution, abundance and ecology of Amazon parrots outside their native range. Our review shows that at least nine species of Amazon parrots have established populations outside their original range of occurrence throughout the world (in Europe, South Africa, the Caribbean islands, Hawaii, and North and South America. Their elusive behaviour and small population size suggest that the number of alien nuclei could be underestimated or at undetected. Despite international trade bans, the large trade of wild–caught Amazon parrots in past decades appears to have contributed to the establishment of alien populations worldwide. Establishment success seems to differ geographically. While European populations are still small and growing slowly, USA populations are large and expanding geographically. This difference is not related to large propagule pressure (trade but possibly to a better niche match between native and introduced ranges. Amazona aestiva is the most frequently encountered Amazona parrot, with at least eight alien populations reported to date. All these populations, with the exception of those in the USA where the climate is more suitable for their establishment, are composed of a low number of individuals even though they have been established for a long period of time. Further research

  15. Space Weather Monitors -- Preparing to Distribute Scientific Devices and Classroom Materials Worldwide for the IHY 2007

    Science.gov (United States)

    Scherrer, D. K.; Burress, B.

    2006-05-01

    Stanford's Solar Center, in conjunction with the Space, Telecommunications and Radioscience Laboratory and local educators, have developed inexpensive Space Weather Monitors that students around the world can use to track solar-induced changes to the Earth's ionosphere. Through the United Nations Basic Space Science Initiative (UNBSSI) and the IHY Education and Public Outreach Program, our Monitors have been designated for deployment to 191 countries for the International Heliophysical Year, 2007. In partnership with Chabot Space and Science Center, we are designing and developing classroom and educator support materials to accompany distribution of the monitors worldwide. Earth's ionosphere reacts strongly to the intense x-ray and ultraviolet radiation released by the Sun during solar events and by lightning during thunderstorms. Students anywhere in the world can directly monitor and track these sudden ionospheric disturbances (SIDs) by using a VLF radio receiver to monitor the signal strength from distant VLF transmitters and noting unusual changes as the waves bounce off the ionosphere. High school students "buy in" to the project by building their own antenna, a simple structure costing little and taking a couple hours to assemble. Data collection and analysis are handled by a local PC. Stanford is providing a centralized data repository where students and researchers can exchange and discuss data. Chabot Space & Science Center is an innovative teaching and learning center focusing on astronomy and the space sciences. Formed as a Joint Powers Agency with the City of Oakland (California), the Oakland Unified School District, the East Bay Regional Park District, and in collaboration with the Eastbay Astronomical Society, Chabot addresses the critical issue of broad access to the specialized information and facilities needed to improve K-12 science education and public science literacy. Up to 2,000 K-12 teachers annually take part in Chabot's professional

  16. A distribution benefits model for improved information on worldwide crop production. Volume 2: Application to various crops

    Science.gov (United States)

    Andrews, J.

    1976-01-01

    ECON's distribution benefits model has been applied to worldwide distribution of corn, rye, oats, barley, soybeans, and sugar, and to domestic distribution of potatoes. The results indicate that a LANDSAT system with thematic mapper might produce benefits to the United States of about $119 million per year, due to more efficient distribution of these commodities. The benefits to the rest of the world have also been calculated, with a breakdown between trade benefits and those associated with internal use patterns. By far the greatest part of the estimated benefits are assigned to corn, with smaller benefits assigned to soybeans and the small grains (rye, oats, and barley).

  17. Estimation and prediction of the HIV-AIDS-epidemic under conditions of HAART using mixtures of incubation time distributions

    NARCIS (Netherlands)

    Heisterkamp, S. H.; de Vries, R.; Sprenger, H. G.; Hubben, G. A. A.; Postma, M. J.

    2008-01-01

    The estimation of the HIV-AIDS epidemic by means of back-calculation (BC) has been difficult since the introduction of highly active anti-retroviral therapy (HAART) because the incubation time distributions needed for BC were poorly known. Moreover, it has been assumed that if the general public is

  18. Analysis of Impact of Geographical Environment and Socio-economic Factors on the Spatial Distribution of Kaohsiung Dengue Fever Epidemic

    Science.gov (United States)

    Hsu, Wei-Yin; Wen, Tzai-Hung; Yu, Hwa-Lung

    2013-04-01

    Taiwan is located in subtropical and tropical regions with high temperature and high humidity in the summer. This kind of climatic condition is the hotbed for the propagation and spread of the dengue vector mosquito. Kaohsiung City has been the worst dengue fever epidemic city in Taiwan. During the study period, from January 1998 to December 2011, Taiwan CDC recorded 7071 locally dengue epidemic cases in Kaohsiung City, and the number of imported case is 118. Our research uses Quantile Regression, a spatial infection disease distribution, to analyze the correlation between dengue epidemic and geographic environmental factors and human society factors in Kaohsiung. According to our experiment statistics, agriculture and natural forest have a positive relation to dengue fever(5.5~34.39 and 3.91~15.52). The epidemic will rise when the ratio for agriculture and natural forest increases. Residential ratio has a negative relation for quantile 0.1 to 0.4(-0.005~-0.78), and a positive relation for quantile 0.5 to0.9(0.01~18.0) . The mean income is also a significant factor in social economy field, and it has a negative relation to dengue fever(-0.01~-0.04). Conclusion from our research is that the main factor affecting the degree of dengue fever in predilection area is the residential proportion and the ratio of agriculture and natural forest plays an important role affecting the degree of dengue fever in non predilection area. Moreover, the serious epidemic area located by regression model is the same as the actual condition in Kaohsiung. This model can be used to predict the serious epidemic area of dengue fever and provide some references for the Health Agencies

  19. Distribution trend of high-rise buildings worldwide and factor exploration

    Science.gov (United States)

    Yu, Shao-Qiao

    2017-08-01

    This paper elaborates the development phenomenon of high-rise buildings nowadays. The development trend of super high-rise buildings worldwide is analyzed based on data from the Council on Tall Buildings and Urban Habitat, taking the top 100 high-rise buildings in different continents and with the time development and building type as the objects. Through analysis, the trend of flourishing of UAE super high-rise buildings and stable development of European and American high-rise buildings is obtained. The reasons for different development degrees of the regions are demonstrated from the aspects of social development, economy, culture and consciousness. This paper also presents unavoidable issues of super high-rise buildings and calls for rational treatment to these buildings.

  20. A distribution benefits model for improved information on worldwide crop production. Volume 1: Model structure and application to wheat

    Science.gov (United States)

    Andrews, J.

    1976-01-01

    The improved model is suitable for the study of benefits of worldwide information on a variety of crops. Application to the previously studied case of worldwide wheat production shows that about $108 million per year of distribution benefits to the United States would be achieved by a satellite-based wheat information system meeting the goals of LACIE. The model also indicates that improved information alone will not change world stock levels unless production itself is stabilized. The United States benefits mentioned above are associated with the reduction of price fluctuations within the year and the more effective use of international trade to balance supply and demand. Price fluctuations from year to year would be reduced only if production variability were itself reduced.

  1. The global avian invasions atlas, a database of alien bird distributions worldwide.

    Science.gov (United States)

    Dyer, Ellie E; Redding, David W; Blackburn, Tim M

    2017-03-28

    The introduction of species to locations where they do not naturally occur (termed aliens) can have far-reaching and unpredictable environmental and economic consequences. Therefore there is a strong incentive to stem the tide of alien species introduction and spread. In order to identify broad patterns and processes of alien invasions, a spatially referenced, global dataset on the historical introductions and alien distributions of a complete taxonomic group is required. Here we present the Global Avian Invasions Atlas (GAVIA)-a new spatial and temporal dataset comprising 27,723 distribution records for 971 alien bird species introduced to 230 countries and administrative areas spanning the period 6000BCE-AD2014. GAVIA was initiated to provide a unified database of records on alien bird introductions, incorporating records from all stages of invasion, including introductions that have failed as well as those that have succeeded. GAVIA represents the most comprehensive resource on the global distribution of alien species in any major taxon, allowing the spatial and temporal dynamics of alien bird distributions to be examined.

  2. The Global Inventor Gap: Distribution and Equality of World-Wide Inventive Effort, 1990–2010

    Science.gov (United States)

    Toivanen, Hannes; Suominen, Arho

    2015-01-01

    Applying distance-to-frontier analysis, we have used 2.9 million patents and population data to assess whether the relative capacity of world countries and major regions to create new knowledge and technology has become globally more equal or less equal between 1990 and 2010. We show with the Gini coefficient that the global distribution of inventors has become more equal between major countries and regions. However, this trend has been largely due to the improved performance of only two major countries, China and India. The worst performing regions, totalling a population of almost 2 billion, are actually falling behind. Our results suggest that substantial parts of the global population have fallen further behind countries at the global frontier in their ability to create new knowledge and inventions, and that the catch-up among the least developed and middle-income countries is highly uneven, prompting questions about the nature and future of the global knowledge economy. PMID:25849202

  3. The global inventor gap: distribution and equality of world-wide inventive effort, 1990-2010.

    Directory of Open Access Journals (Sweden)

    Hannes Toivanen

    Full Text Available Applying distance-to-frontier analysis, we have used 2.9 million patents and population data to assess whether the relative capacity of world countries and major regions to create new knowledge and technology has become globally more equal or less equal between 1990 and 2010. We show with the Gini coefficient that the global distribution of inventors has become more equal between major countries and regions. However, this trend has been largely due to the improved performance of only two major countries, China and India. The worst performing regions, totalling a population of almost 2 billion, are actually falling behind. Our results suggest that substantial parts of the global population have fallen further behind countries at the global frontier in their ability to create new knowledge and inventions, and that the catch-up among the least developed and middle-income countries is highly uneven, prompting questions about the nature and future of the global knowledge economy.

  4. The global inventor gap: distribution and equality of world-wide inventive effort, 1990-2010.

    Science.gov (United States)

    Toivanen, Hannes; Suominen, Arho

    2015-01-01

    Applying distance-to-frontier analysis, we have used 2.9 million patents and population data to assess whether the relative capacity of world countries and major regions to create new knowledge and technology has become globally more equal or less equal between 1990 and 2010. We show with the Gini coefficient that the global distribution of inventors has become more equal between major countries and regions. However, this trend has been largely due to the improved performance of only two major countries, China and India. The worst performing regions, totalling a population of almost 2 billion, are actually falling behind. Our results suggest that substantial parts of the global population have fallen further behind countries at the global frontier in their ability to create new knowledge and inventions, and that the catch-up among the least developed and middle-income countries is highly uneven, prompting questions about the nature and future of the global knowledge economy.

  5. Worldwide genealogy of Entamoeba histolytica: an overview to understand haplotype distribution and infection outcome.

    Science.gov (United States)

    Zermeño, Valeria; Ximénez, Cecilia; Morán, Patricia; Valadez, Alicia; Valenzuela, Olivia; Rascón, Edgar; Diaz, Daniel; Cerritos, René

    2013-07-01

    Although Entamoeba histolytica is one of the most prevalent intestinal parasites, how the different strains of this species are distributed all over the world and how different genotypes are associated with the infection outcome are yet to be fully understood. Recently, the use of a number of molecular markers has made the characterization of several genotypes in those regions with high incidence of amoebiasis possible. This work proposes the first genealogy of E. histolytica, with an haplotype network based on two tRNA gene-linked array of Short Tandem Repeats (STRs) reported until today, and 47 sequences from 39 new isolates of Mexican Amoebic Liver Abscesses (ALA) samples. One hundred and three sequences were obtained from D-A locus, their information about the geographic region of isolation as well as clinical diagnosis were also collected. One hundred and five sequences from N-K2 locus were also obtained as well as the region of isolation, but the information about clinical diagnosis was not available in all cases. The most abundant and widely distributed haplotype in the world is the one of E. histolytica HM1:IMSS strain. This was found in Mexico, Bangladesh, Japan, China and USA and is associated to symptomatic patients as well as asymptomatic cyst passers. Many other haplotypes were found only in a single country. Both genealogies suggest that there are no lineages within the networks that may be related to a particular geographic region or infection outcome. A concatenated analysis of the two molecular markers revealed 12 different combinations, which suggests the possibility of genetic recombination events. The present study is the first to propose a global genealogy of this species and suggests that there are still many genotypes to be discovered. The genotyping of new isolates will help to understand the great diversity and genetic structure of this parasite. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Temperature profile data from MBT casts from NAUKA and other platforms in a World-wide distribution from 12 January 1968 to 17 June 1990 (NODC Accession 0000230)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using MBT casts in a World-wide distribution from the SKIF, MARLIN, NAUKA, and other platforms from 12 January 1968 to 17...

  7. Depth, chlorophyll, and total pigment data were collected using bottle casts in a world-wide distribution from 16 March 1997 to 30 January 1998 (NODC Accession 0000292)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Depth, chlorophyll, and total pigment data were collected using bottle casts from TIOGA and other platforms in a world-wide distribution from March 16, 1997 to...

  8. Temperature profile data from MBT casts from NAUKA and other platforms in a World-wide distribution from 18 June 1970 to 05 May 1989 (NODC Accession 0000229)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using MBT casts in a World-wide distribution from the NAUKA, AELITA, LESNOYE, and other platforms from 18 June 1970 to 05 May...

  9. Temperature profile data from MBT casts in a world-wide distribution from 23 December 1964 to 19 December 1991 (NODC Accession 0000216)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using MBT casts from multiple platforms in a world-wide distribution from December 23, 1964 to December 19, 1991. Additonal...

  10. Temperature profiles from XBT casts from a World-Wide distribution from MULTIPLE PLATFORMS from 1979-06-03 to 1988-05-27 (NODC Accession 8800182)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profiles were collected from XBT casts from a World-Wide distribution. Data were collected from MULTIPLE PLATFORMS from 03 June 1979 to 27 May 1988. Data...

  11. Temperature profile data from XBT casts from a World-Wide Distribution 31 March 1985 to 24 November 1990 (NODC Accession 9700191)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical data were collected from XBT casts from from a World-Wide Distribution from 31 March 1985 to 24 November 1990. Physical parameters include temperature...

  12. Temperature and other data from XBT and MBT casts in a world-wide distribution from 06 March 1958 to 01 April 1958 (NODC Accession 0000336)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and other data were collected using XBT and MBT casts in a world-wide distribution from March 6, 1958 to April 1, 1958. Data were submitted by Duetsches...

  13. Chemical, temperature, and other data from bottle casts in a world-wide distribution from 04 October 1961 to 24 August 1990 (NODC Accession 0000231)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, temperature, and other data were collected using bottle casts in a world-wide distribution from multiple ships from October 4, 1961 to August 24, 1990....

  14. Temperature profiles from MBT casts from a World-Wide distribution from the ALASKA and other platforms from 02 February 1943 to 10 October 1964 (NODC Accession 9200027)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected from MBT casts from a a World-Wide distribution. Data were collected from the ALASKA and other platforms from 02 February...

  15. Stochastic persistence and stationary distribution in an SIS epidemic model with media coverage

    Science.gov (United States)

    Guo, Wenjuan; Cai, Yongli; Zhang, Qimin; Wang, Weiming

    2018-02-01

    This paper aims to study an SIS epidemic model with media coverage from a general deterministic model to a stochastic differential equation with environment fluctuation. Mathematically, we use the Markov semigroup theory to prove that the basic reproduction number R0s can be used to control the dynamics of stochastic system. Epidemiologically, we show that environment fluctuation can inhibit the occurrence of the disease, namely, in the case of disease persistence for the deterministic model, the disease still dies out with probability one for the stochastic model. So to a great extent the stochastic perturbation under media coverage affects the outbreak of the disease.

  16. Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence.

    Directory of Open Access Journals (Sweden)

    Renan Macedo

    Full Text Available Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen's optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen's density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%. Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070 was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans.

  17. Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence

    Science.gov (United States)

    Macedo, Renan; Sales, Lilian Patrícia; Yoshida, Fernanda; Silva-Abud, Lidianne Lemes

    2017-01-01

    Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen’s optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen’s density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans. PMID:29107985

  18. Insularity and the evolution of melanism, sexual dichromatism and body size in the worldwide-distributed barn owl.

    Science.gov (United States)

    Roulin, A; Salamin, N

    2010-05-01

    Island biogeography has provided fundamental hypotheses in population genetics, ecology and evolutionary biology. Insular populations usually face different feeding conditions, predation pressure, intraspecific and interspecific competition than continental populations. This so-called island syndrome can promote the evolution of specific phenotypes like a small (or large) body size and a light (or dark) colouration as well as influence the evolution of sexual dimorphism. To examine whether insularity leads to phenotypic differentiation in a consistent way in a worldwide-distributed nonmigratory species, we compared body size, body shape and colouration between insular and continental barn owl (Tyto alba) populations by controlling indirectly for phylogeny. This species is suitable because it varies in pheomelanin-based colouration from reddish-brown to white, and it displays eumelanic black spots for which the number and size vary between individuals, populations and species. Females are on average darker pheomelanic and display more and larger eumelanic spots than males. Our results show that on islands barn owls exhibited smaller and fewer eumelanic spots and lighter pheomelanic colouration, and shorter wings than on continents. Sexual dimorphism in pheomelanin-based colouration was less pronounced on islands than continents (i.e. on islands males tended to be as pheomelanic as females), and on small islands owls were redder pheomelanic and smaller in size than owls living on larger islands. Sexual dimorphism in the size of eumelanic spots was more pronounced (i.e. females displayed much larger spots than males) in barn owls living on islands located further away from a continent. Our study indicates that insular conditions drive the evolution towards a lower degree of eumelanism, smaller body size and affects the evolution of sexual dichromatism in melanin-based colour traits. The effect of insularity was more pronounced on body size and shape than on melanic

  19. Species distribution models: A comparison of statistical approaches for livestock and disease epidemics.

    Science.gov (United States)

    Hollings, Tracey; Robinson, Andrew; van Andel, Mary; Jewell, Chris; Burgman, Mark

    2017-01-01

    In livestock industries, reliable up-to-date spatial distribution and abundance records for animals and farms are critical for governments to manage and respond to risks. Yet few, if any, countries can afford to maintain comprehensive, up-to-date agricultural census data. Statistical modelling can be used as a proxy for such data but comparative modelling studies have rarely been undertaken for livestock populations. Widespread species, including livestock, can be difficult to model effectively due to complex spatial distributions that do not respond predictably to environmental gradients. We assessed three machine learning species distribution models (SDM) for their capacity to estimate national-level farm animal population numbers within property boundaries: boosted regression trees (BRT), random forests (RF) and K-nearest neighbour (K-NN). The models were built from a commercial livestock database and environmental and socio-economic predictor data for New Zealand. We used two spatial data stratifications to test (i) support for decision making in an emergency response situation, and (ii) the ability for the models to predict to new geographic regions. The performance of the three model types varied substantially, but the best performing models showed very high accuracy. BRTs had the best performance overall, but RF performed equally well or better in many simulations; RFs were superior at predicting livestock numbers for all but very large commercial farms. K-NN performed poorly relative to both RF and BRT in all simulations. The predictions of both multi species and single species models for farms and within hypothetical quarantine zones were very close to observed data. These models are generally applicable for livestock estimation with broad applications in disease risk modelling, biosecurity, policy and planning.

  20. Estimating the probability distribution of the incubation period for rabies using data from the 1948-1954 rabies epidemic in Tokyo.

    Science.gov (United States)

    Tojinbara, Kageaki; Sugiura, K; Yamada, A; Kakitani, I; Kwan, N C L; Sugiura, K

    2016-01-01

    Data of 98 rabies cases in dogs and cats from the 1948-1954 rabies epidemic in Tokyo were used to estimate the probability distribution of the incubation period. Lognormal, gamma and Weibull distributions were used to model the incubation period. The maximum likelihood estimates of the mean incubation period ranged from 27.30 to 28.56 days according to different distributions. The mean incubation period was shortest with the lognormal distribution (27.30 days), and longest with the Weibull distribution (28.56 days). The best distribution in terms of AIC value was the lognormal distribution with mean value of 27.30 (95% CI: 23.46-31.55) days and standard deviation of 20.20 (15.27-26.31) days. There were no significant differences between the incubation periods for dogs and cats, or between those for male and female dogs. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Pan-antimicrobial failure of alexidine as a contact lens disinfectant when heated in Bausch & Lomb plastic containers: implications for the worldwide Fusarium keratitis epidemic of 2004 to 2006.

    Science.gov (United States)

    Elder, B Laurel; Bullock, John D; Warwar, Ronald E; Khamis, Harry J; Khalaf, Shaden Z

    2012-07-01

    ReNu with MoistureLoc (ReNuML), containing the antimicrobial agent alexidine 0.00045%, was associated with the Fusarium keratitis epidemic of 2004 to 2006. Although a single-point source contamination was ruled out, only Fusarium organisms were reported during the outbreak. This study investigated whether the reported loss of antimicrobial effectiveness toward Fusarium of ReNuML after exposure to heat in high-density polyethylene (HDPE) plastic containers could also be demonstrated with other common fungal and bacterial agents of keratitis. A buffered solution of alexidine 0.00045% was incubated in glass and ReNu HDPE plastic containers at room temperature (RT) and 56°C for 4 weeks, serially diluted, and tested for its ability to inhibit the growth of 20 bacterial isolates, 12 non-Fusarium fungal isolates, and 7 Fusarium isolates originally involved in the keratitis epidemic. A statistically significant loss of antimicrobial capability was seen with all fungi, all gram-positive bacteria, and all isolates of Klebsiella when alexidine 0.00045% was incubated at 56°C in ReNu HDPE containers compared with RT or glass incubation (P≤0.0001). Heating of an alexidine solution in ReNu HDPE plastic (but not glass) containers results in the same loss of anti-Fusarium activity as reported when testing the original ReNuML solution. This loss of inhibitory activity is not specific to Fusarium and occurs with other fungi and bacteria that cause keratitis. The reasons for the lack of reports of bacterial and/or non-Fusarium fungal keratitis during the original Fusarium keratitis epidemic remain unclear at this time.

  2. Development of a multiplex serological assay reveals a worldwide distribution of murine astrovirus infections in laboratory mice.

    Directory of Open Access Journals (Sweden)

    Katja Schmidt

    Full Text Available Laboratory mice play a tremendous role in biomedical research in studies on immunology, infection, cancer and therapy. In the course of standardization of mice used in animal experiments, health monitoring constitutes an important instrument towards microbiological standardization. Infections with murine astroviruses (MuAstV were only recently discovered and are, therefore, still relatively unknown in laboratory animal science. In rodent health monitoring viral infections within a population are commonly assessed in terms of specific antibodies by serological testing, as active infection and excretion of virus is often temporary and can easily be missed. So far only ongoing infections with astroviruses can be detected by PCR. The objective of this work was the development of a sensitive and specific MuAstV multiplex serological assay with a high-throughput capability to be used in routine testing of laboratory mice. Four different MuAstV proteins were recombinantly expressed and used as antigens. The best reacting antigen, the capsid spike protein VP27, was selected and tested with a panel of 400 sera of mice from units with a known MuAstV status. Assay sensitivity and specificity resulted in 98.5% and 100%, respectively, compared to RT-PCR results. Eventually this assay was used to test 5529 serum samples in total, during routine diagnostics at the German Cancer Research Center (DKFZ in Heidelberg between 2015 and 2017. High sero-prevalence rates of up to 98% were detected in units with open cages indicating that the virus is highly infectious and circulates within these populations virtually infecting all animals regardless of the mouse strain. In addition, data collected from 312 mice purchased from commercial breeders and from 661 mice from 58 research institutes in 15 countries worldwide allowed the conclusion that MuAstV is widespread in contemporary laboratory mouse populations.

  3. Development of a multiplex serological assay reveals a worldwide distribution of murine astrovirus infections in laboratory mice.

    Science.gov (United States)

    Schmidt, Katja; Butt, Julia; Mauter, Petra; Vogel, Klaus; Erles-Kemna, Andrea; Pawlita, Michael; Nicklas, Werner

    2017-01-01

    Laboratory mice play a tremendous role in biomedical research in studies on immunology, infection, cancer and therapy. In the course of standardization of mice used in animal experiments, health monitoring constitutes an important instrument towards microbiological standardization. Infections with murine astroviruses (MuAstV) were only recently discovered and are, therefore, still relatively unknown in laboratory animal science. In rodent health monitoring viral infections within a population are commonly assessed in terms of specific antibodies by serological testing, as active infection and excretion of virus is often temporary and can easily be missed. So far only ongoing infections with astroviruses can be detected by PCR. The objective of this work was the development of a sensitive and specific MuAstV multiplex serological assay with a high-throughput capability to be used in routine testing of laboratory mice. Four different MuAstV proteins were recombinantly expressed and used as antigens. The best reacting antigen, the capsid spike protein VP27, was selected and tested with a panel of 400 sera of mice from units with a known MuAstV status. Assay sensitivity and specificity resulted in 98.5% and 100%, respectively, compared to RT-PCR results. Eventually this assay was used to test 5529 serum samples in total, during routine diagnostics at the German Cancer Research Center (DKFZ) in Heidelberg between 2015 and 2017. High sero-prevalence rates of up to 98% were detected in units with open cages indicating that the virus is highly infectious and circulates within these populations virtually infecting all animals regardless of the mouse strain. In addition, data collected from 312 mice purchased from commercial breeders and from 661 mice from 58 research institutes in 15 countries worldwide allowed the conclusion that MuAstV is widespread in contemporary laboratory mouse populations.

  4. Distributing space weather monitoring instruments and educational materials worldwide for IHY 2007: The AWESOME and SID project

    Science.gov (United States)

    Scherrer, Deborah; Cohen, Morris; Hoeksema, Todd; Inan, Umran; Mitchell, Ray; Scherrer, Philip

    2008-12-01

    The International Heliophysical Year (IHY) aims to advance our understanding of the fundamental processes that govern the Sun, Earth, and heliosphere. The IHY Education and Outreach Program is dedicated to inspiring the next generation of space and Earth scientists as well as spreading the knowledge, beauty, and relevance of our solar system to the people of the world. In our Space Weather Monitor project we deploy a global network of sensors to high schools and universities to provide quantitative diagnostics of solar-induced ionospheric disturbances, thunderstorm intensity, and magnetospheric activity. We bring real scientific instruments and data in a cost-effective way to students throughout the world. Instruments meet the objectives of being sensitive enough to produce research-quality data, yet inexpensive enough for placement in high schools and universities. The instruments and data have been shown to be appropriate to, and usable by, high school age and early university students. Data contributed to the Stanford data center is openly shared and partnerships between groups in different nations develop naturally. Students and teachers have direct access to scientific expertise. The result is a world-wide collaboration of scientists, teachers, and students to investigate the variability of the ionosphere. The research-quality AWESOME (Atmospheric Weather Electromagnetic System of Observation, Modeling, and Education) instruments have been selected as a participating program by the United Nations Basic Space Science Initiative (UNBSSI). The IHY Committee for International Education and Public Outreach has designated the simpler SID (Sudden Ionospheric Disturbance) monitors to be provided to teacher/student teams in each of the 192 countries of the world.

  5. How Far Could the Alien Boatman Trichocorixa verticalis verticalis Spread? Worldwide Estimation of Its Current and Future Potential Distribution

    OpenAIRE

    Simone Guareschi; Cristina Coccia; David Sánchez-Fernández; José Antonio Carbonell; Josefa Velasco; Luz Boyero; Green, Andy J; Andrés Millán

    2013-01-01

    Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv) is a corixid (Hemiptera) originally distributed in North Ame...

  6. How far could the alien boatman Trichocorixa verticalis verticalis spread? Worldwide estimation of its current and future potential distribution.

    Science.gov (United States)

    Guareschi, Simone; Coccia, Cristina; Sánchez-Fernández, David; Carbonell, José Antonio; Velasco, Josefa; Boyero, Luz; Green, Andy J; Millán, Andrés

    2013-01-01

    Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv) is a corixid (Hemiptera) originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i) to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii) to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of spread, focusing on

  7. How far could the alien boatman Trichocorixa verticalis verticalis spread? Worldwide estimation of its current and future potential distribution.

    Directory of Open Access Journals (Sweden)

    Simone Guareschi

    Full Text Available Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv is a corixid (Hemiptera originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of

  8. Economic Benefits of Improved Information on Worldwide Crop Production: An Optimal Decision Model of Production and Distribution with Application to Wheat, Corn, and Soybeans

    Science.gov (United States)

    Andrews, J.

    1977-01-01

    An optimal decision model of crop production, trade, and storage was developed for use in estimating the economic consequences of improved forecasts and estimates of worldwide crop production. The model extends earlier distribution benefits models to include production effects as well. Application to improved information systems meeting the goals set in the large area crop inventory experiment (LACIE) indicates annual benefits to the United States of $200 to $250 million for wheat, $50 to $100 million for corn, and $6 to $11 million for soybeans, using conservative assumptions on expected LANDSAT system performance.

  9. Worldwide distribution and diversity of seabird ticks: implications for the ecology and epidemiology of tick-borne pathogens.

    Science.gov (United States)

    Dietrich, Muriel; Gómez-Díaz, Elena; McCoy, Karen D

    2011-05-01

    The ubiquity of ticks and their importance in the transmission of pathogens involved in human and livestock diseases are reflected by the growing number of studies focusing on tick ecology and the epidemiology of tick-borne pathogens. Likewise, the involvement of wild birds in dispersing pathogens and their role as reservoir hosts are now well established. However, studies on tick-bird systems have mainly focused on land birds, and the role of seabirds in the ecology and epidemiology of tick-borne pathogens is rarely considered. Seabirds typically have large population sizes, wide geographic distributions, and high mobility, which make them significant potential players in the maintenance and dispersal of disease agents at large spatial scales. They are parasitized by at least 29 tick species found across all biogeographical regions of the world. We know that these seabird-tick systems can harbor a large diversity of pathogens, although detailed studies of this diversity remain scarce. In this article, we review current knowledge on the diversity and global distribution of ticks and tick-borne pathogens associated with seabirds. We discuss the relationship between seabirds, ticks, and their pathogens and examine the interesting characteristics of these relationships from ecological and epidemiological points of view. We also highlight some future research directions required to better understand the evolution of these systems and to assess the potential role of seabirds in the epidemiology of tick-borne pathogens.

  10. Worldwide distribution of the MYH9 kidney disease susceptibility alleles and haplotypes: evidence of historical selection in Africa.

    Directory of Open Access Journals (Sweden)

    Taras K Oleksyk

    2010-07-01

    Full Text Available MYH9 was recently identified as renal susceptibility gene (OR 3-8, p or = 60% than in European Americans (< 4%, revealing a genetic basis for a major health disparity. The population distributions of MYH9 risk alleles and the E-1 risk haplotype and the demographic and selective forces acting on the MYH9 region are not well explored. We reconstructed MYH9 haplotypes from 4 tagging single nucleotide polymorphisms (SNPs spanning introns 12-23 using available data from HapMap Phase II, and by genotyping 938 DNAs from the Human Genome Diversity Panel (HGDP. The E-1 risk haplotype followed a cline, being most frequent within sub-Saharan African populations (range 50-80%, less frequent in populations from the Middle East (9-27% and Europe (0-9%, and rare or absent in Asia, the Americas, and Oceania. The fixation indexes (F(ST for pairwise comparisons between the risk haplotypes for continental populations were calculated for MYH9 haplotypes; F(ST ranged from 0.27-0.40 for Africa compared to other continental populations, possibly due to selection. Uniquely in Africa, the Yoruba population showed high frequency extended haplotype length around the core risk allele (C compared to the alternative allele (T at the same locus (rs4821481, iHs = 2.67, as well as high population differentiation (F(ST(CEU vs. YRI = 0.51 in HapMap Phase II data, also observable only in the Yoruba population from HGDP (F(ST = 0.49, pointing to an instance of recent selection in the genomic region. The population-specific divergence in MYH9 risk allele frequencies among the world's populations may prove important in risk assessment and public health policies to mitigate the burden of kidney disease in vulnerable populations.

  11. Temperature profile data collected using BT and XBT casts in a World-wide distribution from NOAA Ship MALCOLM BALDRIGE and other platforms from 1990-06-22 to 1991-08-29 (NODC Accession 9100184)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship MALCOLM BALDRIGE and other platforms in a World-wide distribution from 22 June 1990 to...

  12. Temperature profile and chemical data collected using XBT and CTD casts from NOAA Ship MALCOLM BALDRIGE and other platforms in a World-wide distribution from 1991-09-17 to 1995-03-23 (NCEI Accession 9500074)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and chemical data were collected using XBT and CTD casts in a World-wide distribution from NOAA Ship MALCOLM BALDRIGE and other platforms from 17...

  13. Air/delta/sea surface temperature, pressure, and other data from MISS GAIL in a world-wide distribution from 21 October 1957 to 18 April 1961 (NODC Accession 0000366)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Air/delta/sea surface temperature, pressure, and other data were collected from the MISS GAIL in a world-wide distribution from October 21, 1957 to April 18, 1961....

  14. Temperature profile data from XBT casts from a world-wide distribution from the SEA-LAND HAWAII and other platforms as part of NOAA's Volunteer Observing Ships Program from 05 January 2000 to 26 February 2002 (NODC Accession 0000679)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profiles were collected by using XBT casts from the SEA-LAND HAWAII and other platforms from a world-wide distribution from 05 January 2000 to 26...

  15. Temperature profile data collected using BT and XBT casts in a World-wide distribution from NOAA Ship MALCOLM BALDRIGE and other platforms from 1988-02-03 to 1990-03-31 (NODC Accession 9000094)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship MALCOLM BALDRIGE in a World-wide distribution from 03 February 1988 to 31 March 1990....

  16. Temperature profile data collected using BT and XBT casts in a World-wide distribution from NOAA Ship MALCOLM BALDRIGE and other platforms from 1989-03-10 to 1990-08-01 (NODC Accession 9000239)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship MALCOLM BALDRDIGE and other platforms in a World-wide distribution from 10 March 1989...

  17. Physical and chemical data collected using bottle casts in a World-wide distribution from NOAA Ship RESEARCHER and other platforms from 1911-11-11 to 1990-03-18 (NODC Accession 9600072)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and chemical data were collected using bottle casts in a World-wide distribution from NOAA Ship RESEARCHER and other platforms from 11 November 1911 to 18...

  18. Physical, chemical, meteorological, and nutrients data from bottle casts from a world-wide distribution from the YERMAK and other platforms from 15 January 1873 to 15 June 1967 (NODC Accession 0000505)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, meteorological, and nutrients data were collected from bottle casts from the YERMAK and other platforms from a world-wide distribution from 15 January 1873...

  19. Temperature profile data collected using XBT and BT casts in a World-wide distribution from NOAA Ship RESEARCHER and other platforms from 1970-09-30 to 1979-08-05 (NCEI Accession 8300089)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship RESEARCHER and other platforms in a World-wide distribution from 30 September 1970 to...

  20. Temperature data from XBT casts in a world-wide distribution as part of the Gulf of Mexico NOAA/NMFS Ship of Opportunity (SOOP) project from 07 July 2002 to 17 September 2002 (NODC Accession 0000790)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature data were collected using XBT casts in a world-wide distribution from 07 July 2002 to 17 September 2002. Data were submitted by Atlantic Oceanographic...

  1. Temperature profile data collected using XBT and BT casts in a world-wide distribution from NOAA Ship RESEARCHER and other platforms from 1982-08-18 to 1982-12-21 (NCEI Accession 8300007)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship RESEARCHER and other platforms in a world-wide distribution from 18 August 1982 to 21...

  2. Temperature profile data from XBT casts from a world-wide distribution from the SKOGAFOSS and other vessels as part of NOAA's Volunteer Observing Ships Program from 06 February 2002 to 10 April 2002 (NODC Accession 0000718)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profiles were collected from XBT casts from the SKOGAFOSS and other platforms from a world-wide distribution from 06 February 2002 to 10 April 2002. Data...

  3. Temperature profile data from XBT casts from a world-wide distribution from the SEA-LAND NAVIGATOR and other platforms from 21 September 2000 to 18 March 2002 (NODC Accession 0000696)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profiles were collected by deploying XBT casts from the SEA-LAND NAVIGATOR and other platforms over a world-wide distribution from 21 September 2000 to...

  4. Temperature profile data from XBT casts in a World-wide distribution from NOAA Ship RESEARCHER and other platforms from 1982-05-24 to 1996-03-21 (NODC Accession 9600116)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT casts in a World-wide distribution from NOAA Ship RESEARCHER and other platforms from 24 May 1982 to 21 March 1996....

  5. Temperature profile data collected using BT and XBT casts in a World-wide distribution from NOAA Ship MALCOLM BALDRIGE and other platforms from 1990-09-07 to 1994-05-29 (NCEI Accession 9400049)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship MALCOLM BALDRIGE and other platforms in a World-wide distribution from 07 September...

  6. Temperature, salinity, and nutrients data from CTD and bottle casts from a world-wide distribution from the CORNIDE DE SAAVEDRA and other platforms from 01 January 1914 to 12 December 1999 (NODC Accession 0000207)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD, bottle, and other data were collected from the CORNIDE DE SAAVEDRA and other platforms from a world-wide distribution from 01 January 1914 to 31 December 1999....

  7. Temperature profiles from XBT casts from a world-wide distribution from the TAI-HE and other platforms from 05 August 2000 to 21 March 2001 (NODC Accession 0000427)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT and other data were collected from a world-wide distribution from the TAI-HE and other cooperating platforms from 05 August 2000 to 21 March 2001. Data were...

  8. Temperature, salinity, and nutrients data from CTD and bottle casts from a world-wide distribution from the ANDROMEDA and other platforms from 01 January 1923 to 31 December 1999 (NODC Accession 0000208)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD and bottle data were collected from the ANDROMEDA and other platforms from a world-wide distribution from 01 January 1923 to 31 December 1999. Data were...

  9. Temperature profiles from XBT casts from a world-wide distribution from the EMERALD INDAH and other platforms from 28 November 2000 to 29 May 2001 (NODC Accession 0000465)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT and other data were collected from a world-wide distribution from the EMERALD INDAH and other platforms from 28 November 2000 to 29 May 2001. Data were submitted...

  10. Temperature and nutrients data collected using bottle casts from the SKIF and other platforms in a World-wide distribution from 06 July 1962 to 08 January 1990 (NODC Accession 0000856)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and nutrients data were collected using bottle casts in a World-wide distribution from SKIF and other platforms. Data were collected from 06 July 1962 to...

  11. Physical, biological, and chemical data from radiometer, profiling reflectance radiometer, and CTD casts in a world-wide distribution as part of the SeaWiFS/SIMBIOS project from 13 September 1981 to 16 December 1999 (NODC Accession 0000632)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, biological, and chemical data were collected using radiometer, profiling reflectance radiometer, and CTD casts in a world-wide distribution from 13...

  12. Identification of Distribution Characteristics and Epidemic Trends of Hepatitis E in Zhejiang Province, China from 2007 to 2012

    Science.gov (United States)

    Liu, Kui; Cai, Jian; Wang, Shan; Wu, Zhaofan; Li, Li; Jiang, Tao; Chen, Bin; Cai, Gaofeng; Jiang, Zhenggang; Chen, Yongdi; Wang, Zhengting; Zhu, Xuhui; Hu, Liuru; Gu, Hua; Jiang, Jianmin

    2016-01-01

    Hepatitis E virus is a common hepatotropic virus that causes serious gastrointestinal symptoms. Data of reported HEV cases in Zhejiang Province was collected between 2007 and 2012. Descriptive epidemiological methods and spatial-temporal epidemiological methods were used to investigate the epidemiological trends and identify high-risk regions of hepatitis E infection. In this study, the average morbidity of hepatitis E infection was 4.03 per 100,000 in Zhejiang Province, peaking in winter and spring. The ratio between the male and the female was 2.39:1, and the high-risk population was found to be aged between 40 and 60. Trend surface analysis and IDW maps revealed higher incidences in the northwestern counties. The spatial-temporal analysis showed comparable incidences in the counties at the basins of three rivers, mostly under administration of Hangzhou Municipality. Besides, the seasonal exponential smoothing method was determined as the better model for the retrieved data. The epidemiological characteristics of HEV suggested the need of strengthened supervision and surveillance of sanitary water, sewage treatment and food in high-risk areas especially around the Spring Festival. Additionally, time series model could be useful for forecasting the epidemics of HEV in future. All these findings may contribute to the prevention and control of HEV epidemics. PMID:27146250

  13. Hepatitis B and hepatitis C viruses: a review of viral genomes, viral induced host immune responses, genotypic distributions and worldwide epidemiology

    Directory of Open Access Journals (Sweden)

    Umar Saeed

    2014-04-01

    Full Text Available Hepatitis B and hepatitis C viruses (HCV are frequently propagating blood borne pathogens in global community. Viral hepatitis is primarily associated with severe health complications, such as liver cirrhosis, hepatocellular carcinoma, hepatic fibrosis and steatosis. A literature review was conducted on hepatitis B virus (HBV, HBV genome, genotypic distribution and global epidemiology of HBV, HCV, HCV genome, HCV and host immune responses, HCV genotypic distribution and global epidemiology. The valued information was subjected for review. HBV has strict tissue tropism to liver. The virus infecting hepatocytes produces large amount of hepatitis B surface antigen particles which lack the DNA. It has capability to integrate into host genome. It has been found that genotype C is most emerging genotype associated with more severe liver diseases (cirrhosis. The approximate prevalence rate of genotype C is 27.7% which represents a major threat to future generations. Approximately 8% of population is chronic carrier of HBV in developing countries. The chronic carrier rate of HBV is 2%-7% in Middle East, Eastern and Southern Europe, South America and Japan. Among HCV infected individuals, 15% usually have natural tendency to overcome acute viral infection, where as 85% of individuals were unable to control HCV infection. The internal ribosomal entry site contains highly conserved structures important for binding and appropriate positioning of viral genome inside the host cell. HCV infects only in 1%-10% of hepatocytes, but production of tumor necrosis factor alpha (from CD8+ cells and interferon-gamma cause destruction of both infected cells and non-infected surrounding cells. Almost 11 genotypes and above 100 subtypes of HCV exists worldwide with different geographical distribution. Many efforts are still needed to minimize global burden of these infections. For the complete eradication of HBV (just like small pox and polio via vaccination strategies

  14. Distribution of HIV-1 and HSV-2 epidemics in Chad revealing HSV-2 hot-spot in regions of high-risk HIV spread.

    Science.gov (United States)

    Charpentier, Charlotte; Koyalta, Donato; Ndinaromtan, Montana; Tchobkréo, Bagamla; Jenabian, Mohammad-Ali; Day, Nesrine; Si-Mohamed, Ali; Weiss, Helen; Bélec, Laurent

    2011-02-01

    Herpes Simplex Virus-2 (HSV-2) is known to be a potent co-factor of Human Immunodeficiency type 1 virus (HIV-1) heterosexual transmission. We were interested in assessing the distribution of HIV-1 and HSV-2 epidemics at the national level in Chad. In 2007, a population-based anonymous serosurvey for HIV-1 and HSV-2 infections, using dried blood spots, was conducted. The study included 548 adults living in 15 regions of Chad. After specimen elution, serological testing for HIV and HSV-2 infections was performed. Countrywide, the HIV-1 and HSV-2 seroprevalences were 11.1% and 15.7%, respectively. A positive correlation was observed with the highest HIV-1 prevalence seen in regions of the highest HSV-2 prevalence, especially in two conflict-affected eastern provinces of Darfur. Urgent public health interventions are needed in regions of Chad where high HSV-2 prevalence may be increasing the risk of HIV propagation.

  15. Streptococcus suis, an important pig pathogen and emerging zoonotic agent—an update on the worldwide distribution based on serotyping and sequence typing

    Science.gov (United States)

    Goyette-Desjardins, Guillaume; Auger, Jean-Philippe; Xu, Jianguo; Segura, Mariela; Gottschalk, Marcelo

    2014-01-01

    Streptococcus suis is an important pathogen causing economic problems in the pig industry. Moreover, it is a zoonotic agent causing severe infections to people in close contact with infected pigs or pork-derived products. Although considered sporadic in the past, human S. suis infections have been reported during the last 45 years, with two large outbreaks recorded in China. In fact, the number of reported human cases has significantly increased in recent years. In this review, we present the worldwide distribution of serotypes and sequence types (STs), as determined by multilocus sequence typing, for pigs (between 2002 and 2013) and humans (between 1968 and 2013). The methods employed for S. suis identification and typing, the current epidemiological knowledge regarding serotypes and STs and the zoonotic potential of S. suis are discussed. Increased awareness of S. suis in both human and veterinary diagnostic laboratories and further establishment of typing methods will contribute to our knowledge of this pathogen, especially in regions where complete and/or recent data is lacking. More research is required to understand differences in virulence that occur among S. suis strains and if these differences can be associated with specific serotypes or STs. PMID:26038745

  16. Selection on a eumelanic ornament is stronger in the tropics than in temperate zones in the worldwide-distributed barn owl.

    Science.gov (United States)

    Roulin, A; Wink, M; Salamin, N

    2009-02-01

    Spatial variation in the pattern of natural selection can promote local adaptation and genetic differentiation between populations. Because heritable melanin-based ornaments can signal resistance to environmentally mediated elevation in glucocorticoids, to oxidative stress and parasites, populations may vary in the mean degree of melanic coloration if selection on these phenotypic aspects varies geographically. Within a population of Swiss barn owls (Tyto alba), the size of eumelanic spots is positively associated with survival, immunity and resistance to stress, but it is yet unknown whether Tyto species that face stressful environments evolved towards a darker eumelanic plumage. Because selection regimes vary along environmental gradients, we examined whether melanin-based traits vary clinally and are expressed to a larger extent in the tropics where parasites are more abundant than in temperate zones. To this end, we considered 39 barn owl species distributed worldwide. Barn owl species living in the tropics displayed larger eumelanic spots than those found in temperate zones. This was, however, verified in the northern hemisphere only. Parasites being particularly abundant in the tropics, they may promote the evolution of darker eumelanic ornaments.

  17. Rubella Epidemics and Genotypic Distribution of the Rubella Virus in Shandong Province, China, in 1999–2010

    Science.gov (United States)

    Xu, Qing; Xu, Aiqiang; Fang, Xueqiang; Song, Lizhi; Li, Weixiu; Xiong, Ping; Xu, Wenbo

    2012-01-01

    Background The rubella vaccine was introduced into the immunization program in 1995 in the Shandong province, China. A series of different rubella vaccination strategies were implemented at different stages of measles control in Shandong province. Methodology/Principal Findings The average reported incidence rate of rubella cases remained at a low level in Shandong province after 1999. However, rubella epidemics occurred repeatedly in 2001/2002, 2006, and 2008/2009. The age of the onset of rubella cases gradually increased during 1999–2010, which showed that most cases were found among the 10 years old in 1999 and among the 17 years old in 2010. Phylogenetic analysis was performed and a phylogenetic tree was constructed based on the World Health Organization standard sequence window for rubella virus isolates. All rubella viruses isolated in Shandong province were divided into 4 genotypes: 1E, 1F, 2A, and 2B. Genotype 1E viruses accounted for the majority (79%) of all these viruses. The similarity of nucleotide and amino acid sequences among genotype 1E viruses was 98.2–100% and 99.1–100%, respectively. All Shandong genotype 1E strains, differed from international genotype 1E strains, belonged to cluster 1 and interdigitated with the viruses from other provinces in mainland China. The effective number of infections indicated by a Bayesian skyline plot remained constant from 2001 to 2009. Conclusions/Significance The gradual shift of disease burden to an older age group occurred after a rubella-containing vaccine was introduced into the childhood immunization schedule in 1995 in Shandong province. Four genotypes, including 1E, 1F, 2A, and 2B, were found in Shandong province during 2000–2009. Genotype 1E, rather than genotype 1F, became the predominant genotype circulating in Shandong province from 2001. All Shandong genotype 1E viruses belong to the genotype 1E/cluster 1; they have constantly circulated, and co-evolved and co-circulated, with those from

  18. Worldwide regulations for mycotoxins.

    Science.gov (United States)

    van Egmond, Hans P

    2002-01-01

    Since the discovery of the aflatoxins in the 1960s, regulations have been established in many countries to protect the consumer from the harmful effects of mycotoxins that may contaminate foodstuffs. Various factors play a role in the decision-making process of setting limits for mycotoxins. These include scientific factors such as the availability of toxicological data, survey data, knowledge about the distribution of mycotoxins in commodities, and analytical methodology. Economical and political factors such as commercial interests and sufficiency of food supply have their impact as well. International enquiry's on existing mycotoxin legislation in foodstuffs and animal feedstuffs have been carried out several times in the 1980s and 1990s and details about tolerances, legal basis, responsible authorities, official protocols of analysis and sampling have been published. Recently a comprehensive update on worldwide regulations was published as FAO Food and Nutrition Paper 64. It appeared that at least 77 countries now have specific regulations for mycotoxins, 13 countries are known to have no specific regulations, whereas no data are available for about 50 countries, many of them in Africa. Over the years, a large diversity in tolerance levels for mycotoxins has remained. Some free trade zones (EU, MERCOSUR) are in the process of harmonizing the limits and regulations for mycotoxins in their respective member states, but it is not likely that worldwide harmonized limits for mycotoxins will soon be within reach.

  19. Epidemic cholera spreads like wildfire

    Science.gov (United States)

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

    2014-01-01

    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.

  20. Obesity, insulin resistance and diabetes--a worldwide epidemic

    NARCIS (Netherlands)

    Seidell, J C

    Obesity is now commonly defined in adults as a BMI > 30 kg/m2. The prevalence of obesity in established market economies (Europe, USA, Canada, Australia, etc.) varies greatly, but a weighed estimate suggests an average prevalence in the order of 15-20%. The prevalence in these countries generally

  1. Mineralogical Distribution of Germanium, Gallium and Indium at the Mt Carlton High-Sulfidation Epithermal Deposit, NE Australia, and Comparison with Similar Deposits Worldwide

    Directory of Open Access Journals (Sweden)

    Fredrik Sahlström

    2017-11-01

    Full Text Available Germanium, gallium and indium are in high demand due to their growing usage in high-tech and green-tech applications. However, the mineralogy and the mechanisms of concentration of these critical elements in different types of hydrothermal ore deposits remain poorly constrained. We investigated the mineralogical distribution of Ge, Ga and In at the Mt Carlton high-sulfidation epithermal deposit in NE Australia, using electron probe microanalysis and laser ablation inductively-coupled plasma mass spectrometry. Parageneses from which selected minerals were analyzed include: Stage 1 acid sulfate alteration (alunite, Stage 2A high-sulfidation enargite mineralization (enargite, argyrodite, sphalerite, pyrite, barite, Stage 2B intermediate-sulfidation sphalerite mineralization (sphalerite, pyrite, galena and Stage 3 hydrothermal void fill (dickite. Moderate to locally high concentrations of Ga were measured in Stage 1 alunite (up to 339 ppm and in Stage 3 dickite (up to 150 ppm. The Stage 2A ores show enrichment in Ge, which is primarily associated with argyrodite (up to 6.95 wt % Ge and Ge-bearing enargite (up to 2189 ppm Ge. Co-existing sphalerite has comparatively low Ge content (up to 143 ppm, while Ga (up to 1181 ppm and In (up to 571 ppm are higher. Sphalerite in Stage 2B contains up to 611 ppm Ge, 2829 ppm Ga and 2169 ppm In, and locally exhibits fine colloform bands of an uncharacterized Zn-In mineral with compositions close to CuZn2(In,GaS4. Barite, pyrite and galena which occur in association with Stage 2 mineralization were found to play negligible roles as carriers of Ge, Ga and In at Mt Carlton. Analyzed reference samples of enargite from seven similar deposits worldwide have average Ge concentrations ranging from 12 to 717 ppm (maximum 2679 ppm. The deposits from which samples showed high enrichment in critical elements in this study are all hosted in stratigraphic sequences that locally contain carbonaceous sedimentary rocks. In

  2. AIDS epidemic.

    African Journals Online (AJOL)

    the rationalistic ethics of Immanuel. Kant, has popularised the 4 so-called principles of beneficence (do good), non-maleficence (do not harm), per- sonal autonomy (deliberate self rule) and distributive justice (fair adjudica- tion between competing claims). In an increasingly secular, pleuralistic socie- ty, the Western medical ...

  3. Toward Robust Climate Baselining: Objective Assessment of Climate Change Using Widely Distributed Miniaturized Sensors for Accurate World-Wide Geophysical Measurements

    Science.gov (United States)

    Teller, E.; Leith, C.; Canavan, G.; Marion, J.; Wood, L.

    2001-11-13

    A gap-free, world-wide, ocean-, atmosphere-, and land surface-spanning geophysical data-set of three decades time-duration containing the full set of geophysical parameters characterizing global weather is the scientific perquisite for defining the climate; the generally-accepted definition in the meteorological community is that climate is the 30-year running-average of weather. Until such a tridecadal climate baseline exists, climate change discussions inevitably will have a semi-speculative, vs. a purely scientific, character, as the baseline against which changes are referenced will at least somewhat uncertain.

  4. Worldwide Airfield Summary

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Worldwide Airfield Summary contains a selection of climatological data produced by the U.S. Air Force, Air Weather Service. The reports were compiled from dozens...

  5. Predicting extinction rates in stochastic epidemic models

    Science.gov (United States)

    Schwartz, Ira B.; Billings, Lora; Dykman, Mark; Landsman, Alexandra

    2009-01-01

    We investigate the stochastic extinction processes in a class of epidemic models. Motivated by the process of natural disease extinction in epidemics, we examine the rate of extinction as a function of disease spread. We show that the effective entropic barrier for extinction in a susceptible-infected-susceptible epidemic model displays scaling with the distance to the bifurcation point, with an unusual critical exponent. We make a direct comparison between predictions and numerical simulations. We also consider the effect of non-Gaussian vaccine schedules, and show numerically how the extinction process may be enhanced when the vaccine schedules are Poisson distributed.

  6. Toward Robust Climate Baselining: Objective Assessment of Climate Change Using Widely Distributed Miniaturized Sensors for Accurate World-Wide Geophysical Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Teller, E; Leith, C; Canavan, G; Marion, J; Wood, L

    2001-11-13

    A gap-free, world-wide, ocean-, atmosphere-, and land surface-spanning geophysical data-set of three decades time-duration containing the full set of geophysical parameters characterizing global weather is the scientific perquisite for defining the climate; the generally-accepted definition in the meteorological community is that climate is the 30-year running-average of weather. Until such a tridecadal climate base line exists, climate change discussions inevitably will have a semi-speculative, vs. a purely scientific, character, as the baseline against which changes are referenced will be at least somewhat uncertain. The contemporary technology base provides ways-and-means for commencing the development of such a meteorological measurement-intensive climate baseline, moreover with a program budget far less than the {approx}$2.5 B/year which the US. currently spends on ''global change'' studies. In particular, the recent advent of satellite-based global telephony enables real-time control of, and data-return from, instrument packages of very modest scale, and Silicon Revolution-based sensor, data-processing and -storage advances permit 'intelligent' data-gathering payloads to be created with 10 gram-scale mass budgets. A geophysical measurement system implemented in such modern technology is a populous constellation 03 long-lived, highly-miniaturized robotic weather stations deployed throughout the weather-generating portions of the Earths atmosphere, throughout its oceans and across its land surfaces. Leveraging the technological advances of the OS, the filly-developed atmospheric weather station of this system has a projected weight of the order of 1 ounce, and contains a satellite telephone, a GPS receiver, a full set of atmospheric sensing instruments and a control computer - and has an operational life of the order of 1 year and a mass-production cost of the order of $20. Such stations are effectively &apos

  7. Heterogeneous Epidemic Model for Assessing Data Dissemination in Opportunistic Networks

    DEFF Research Database (Denmark)

    Rozanova, Liudmila; Alekseev, Vadim; Temerev, Alexander

    2014-01-01

    that amount of data transferred between network nodes possesses a Pareto distribution, implying scale-free properties. In this context, more heterogeneity in susceptibility means the less severe epidemic progression, and, on the contrary, more heterogeneity in infectivity leads to more severe epidemics...... — assuming that the other parameter (either heterogeneity or susceptibility) stays fixed. The results are general enough to be useful for estimating the epidemic progression with no significant acquired immunity — in the cases where Pareto distribution holds....

  8. Sharka epidemiology and worldwide management strategies: learning lessons to optimize disease control in perennial plants

    Science.gov (United States)

    Many plant epidemics that cause major economic losses cannot be controlled with pesticides. Among them, sharka epidemics severely affect prunus trees worldwide. Its causal agent, Plum pox virus (PPV;, genus Potyvirus), has been classified as a quarantine pathogen in numerous countries. As a result, ...

  9. Recent invasion of world-wide wheat growing areas by two aggressive strains of Puccinia striiformis

    DEFF Research Database (Denmark)

    Walter, Stephanie; Ali, Sajid; Justesen, Annemarie Fejer

    2012-01-01

    The ever more frequent and severe large-scale epidemics of wheat yellow/stripe rust disease (caused by Puccinia striiformis) pose a severe threat to the world’s wheat production (Hovmøller et al. 2010). The onset of a new series of world-wide wheat yellow rust epidemics in 2000 has been linked...

  10. Worldwide Report, Epidemiology, No. 327

    National Research Council Canada - National Science Library

    1983-01-01

    Partial Contents: Epidemiology, Human Diseases, Health, Malaria, AIDS, Homosexual Male, Medical Administration, Rabies, Tuberculosis, Encephalitis Statistics, Gastroenteritie, Mystery Diseases, Children, Epidemics...

  11. Aspects on the history of transmission and favor of distribution of viruses by iatrogenic action: perhaps an example of a paradigm of the worldwide spread of HIV.

    Science.gov (United States)

    Gürtler, Lutz G; Eberle, Josef

    2017-08-01

    Transmission of infectious agents might be associated with iatrogenic actions of charitable help in health care. An example is the vaccination against yellow fever in USA that transmitted hepatitis B virus. Another example is injections of praziquantel for treatment and cure of schistosomiasis in Central and Northern Africa, with a focus in Egypt that has spread hepatitis C virus. There is no indication that human T-lymphotropic virus type 1 was spread by injection treatment for African trypanosomiasis, syphilis and treponematosis, but these treatments might have contributed to the early spread of human immunodeficiency virus type 1 (HIV-1) in Central Africa. Slave trade contributed as well to the spread of viruses from Africa to the Americas; it was stopped in 1850. Until that date HIV-1 was not transported to the Americas. By analysis of nucleic acid sequence data it can be concluded that the continental spread of HCV and HIV-1 might have started around 1920 with an exponential phase from 1940 to 1970. Further iatrogenic actions that promoted the spread of HCV and HIV-1 might be vaccinations to prevent deadly diseases. The successful vaccination was followed by diminution of the infectious agent in the population such as small pox, yellow fever and measles. Measurements to reduce the spread of plague and cholera were further benefits increasing survival of diseased subjects in a population. Thus, the reduction of exposure to deadly infectious agents might have given a chance to HIV-1 infected subjects to survive and for HIV-1 to be distributed around the world starting from Central Africa in the 1950s.

  12. Epidemic spread on weighted networks.

    Directory of Open Access Journals (Sweden)

    Christel Kamp

    Full Text Available 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 (r0 and the basic reproductive ratio (R0, 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.

  13. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...

  14. Epidemic thresholds for bipartite networks

    Science.gov (United States)

    Hernández, D. G.; Risau-Gusman, S.

    2013-11-01

    It is well known that sexually transmitted diseases (STD) spread across a network of human sexual contacts. This network is most often bipartite, as most STD are transmitted between men and women. Even though network models in epidemiology have quite a long history now, there are few general results about bipartite networks. One of them is the simple dependence, predicted using the mean field approximation, between the epidemic threshold and the average and variance of the degree distribution of the network. Here we show that going beyond this approximation can lead to qualitatively different results that are supported by numerical simulations. One of the new features, that can be relevant for applications, is the existence of a critical value for the infectivity of each population, below which no epidemics can arise, regardless of the value of the infectivity of the other population.

  15. Competing activation mechanisms in epidemics on networks

    Science.gov (United States)

    Castellano, Claudio; Pastor-Satorras, Romualdo

    2012-04-01

    In contrast to previous common wisdom that epidemic activity in heterogeneous networks is dominated by the hubs with the largest number of connections, recent research has pointed out the role that the innermost, dense core of the network plays in sustaining epidemic processes. Here we show that the mechanism responsible of spreading depends on the nature of the process. Epidemics with a transient state are boosted by the innermost core. Contrarily, epidemics allowing a steady state present a dual scenario, where either the hub independently sustains activity and propagates it to the rest of the system, or, alternatively, the innermost network core collectively turns into the active state, maintaining it globally. In uncorrelated networks the former mechanism dominates if the degree distribution decays with an exponent larger than 5/2, and the latter otherwise. Topological correlations, rife in real networks, may perturb this picture, mixing the role of both mechanisms.

  16. Epidemic spreading on weighted complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ye [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Liu, Chuang, E-mail: liuchuang@hznu.edu.cn [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Chu-Xu [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Zi-Ke, E-mail: zhangzike@gmail.com [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China)

    2014-01-31

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  17. Temperature profile and other data collected using bottle and CTD casts from the A. AGASSIZ and other platforms from a world-wide distribution during the California Cooperative Fisheries Investigation (CALCOFI) project, 06 January 1969 to 27 July 1977 (NODC Accession 8000006)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data, temperature, and other data were collected using CTD and bottle casts from A. AGASSIZ and other platforms in a world-wide distribution...

  18. Temperature profile and other data collected using bottle and CTD casts from the HMAS DERWENT and other platforms from a world-wide distribution during the California Cooperative Fisheries Investigation (CALCOFI) project, 03 August 1904 to 31 December 1964 (NODC Accession 6400000)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data, temperature, and other data were collected using CTD and bottle casts from HMAS DERWENT and other platforms in a world-wide distribution...

  19. Temperature profile data from STD/CTD casts from the KNORR from a world-wide distribution during the International Decade of Ocean Exploration / Geochemical Ocean Section Study (IDOE/GEOSECS) project, 24 July 1972 - 09 June 1974 (NODC Accession 8200010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data were collected using STD/CTD casts from KNORR in a world-wide distribution from July 24, 1972 to June 9, 1974. Data were...

  20. Temperature profile and other data collected using bottle and CTD casts from the PARRAMATTA and other platforms in a world-wide distribution during the California Cooperative Fisheries Investigation (CALCOFI) project, 04 October 1903 to 19 December 1963 (NODC Accession 6300000)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data, temperature, and other data were collected using CTD and bottle casts from PARRAMATTA and other platforms in a world-wide distribution...

  1. Compilation of ocean circulation and other data from ADCP current meters, CTD casts, tidal gauges, and other instruments from a World-Wide distribution by Oregon State University and other institutions as part of World Ocean Circulation Experiment (WOCE) and other projects from 24 November 1985 to 30 December 2000 (NODC Accession 0000649)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Compilation of ocean circulation and other data were collected from a World-Wide distribution by Oregon State University (OSU) and other institutions as part of...

  2. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes

    OpenAIRE

    Hui Yang; Ming Tang; Thilo Gross

    2015-01-01

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that network heterogeneity, i.e. a broad degree distribution, can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. Howeve...

  3. Understanding the Opioid Epidemic

    Science.gov (United States)

    ... Search Form Controls Cancel Submit Search The CDC Opioid Overdose Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Opioid Overdose Opioid Basics Understanding the Epidemic Commonly Used ...

  4. Dynamics of beneficial epidemics

    CERN Document Server

    Berdahl, Andrew; De Bacco, Caterina; Dumas, Marion; Ferdinand, Vanessa; Grochow, Joshua A; Hébert-Dufresne, Laurent; Kallus, Yoav; Kempes, Christopher P; Kolchinsky, Artemy; Larremore, Daniel B; Libby, Eric; Power, Eleanor A; Stern, Caitlin A; Tracey, Brendan

    2016-01-01

    Pathogens can spread epidemically through populations. Beneficial contagions, such as viruses that enhance host survival or technological innovations that improve quality of life, also have the potential to spread epidemically. How do the dynamics of beneficial biological and social epidemics differ from those of detrimental epidemics? We investigate this question using three theoretical approaches as well as an empirical analysis of concept propagation. First, in evolutionary models, we show that a beneficial horizontally-transmissible element, such as viral DNA, spreads super-exponentially through a population, substantially more quickly than a beneficial mutation. Second, in an epidemiological social network approach, we show that infections that cause increased connectivity lead to faster-than-exponential fixation in the population. Third, in a sociological model with strategic rewiring, we find that preferences for increased global infection accelerate spread and produce super-exponential fixation rates,...

  5. Modularity promotes epidemic recurrence

    CERN Document Server

    Jesan, T; Sinha, Sitabhra

    2016-01-01

    The long-term evolution of epidemic processes depends crucially on the structure of contact networks. As empirical evidence indicates that human populations exhibit strong community organization, we investigate here how such mesoscopic configurations affect the likelihood of epidemic recurrence. Through numerical simulations on real social networks and theoretical arguments using spectral methods, we demonstrate that highly contagious diseases that would have otherwise died out rapidly can persist indefinitely for an optimal range of modularity in contact networks.

  6. Worldwide molecular epidemiology of HIV

    Directory of Open Access Journals (Sweden)

    Henry I Z Requejo

    2006-04-01

    Full Text Available Human immunodeficiency virus (HIV is the worldwide disseminated causative agent of acquired immunodeficiency syndrome (AIDS. HIV is a member of the Lentivirus genus of Retroviridae family and is grouped in two types named HIV-1 and HIV-2. These viruses have a notable ability to mutate and adapt to the new conditions of human environment. A large incidence of errors at the transcriptional level results in changes on the genetic bases during the reproductive cycle. The elevated genomic variability of HIV has carried important implications for the diagnosis, treatment and prevention as well as epidemiologic investigations. The present review describes important definitions and geographical distribution of subtypes, circulating recombinant forms and other genomic variations of HIV. The present study aimed at leading students of Biomedical Sciences and public health laboratory staff guidance to general and specific knowledge about the genomic variability of the HIV.

  7. An epidemic outbreak of cryptosporidiosis

    DEFF Research Database (Denmark)

    Mølbak, Kåre; Højlyng, Niels; Ingholt, Liselotte

    1990-01-01

    In the first year of a prospective community study of childhood diarrhea conducted in a semiurban area in the capital of Guinea Bissau, Cryptosporidium sp. was found in 73 (6.0%) of 1216 episodes of diarrhea. The parasite was the second most prevalent intestinal parasite, and the only one...... significantly associated with diarrhea (OR = 2.79, P = 0.0006). The seasonal distribution was striking, with a peak prevalence in the beginning of the rainy season (May 17.6%) when an epidemic outbreak of diarrhea started. The prevalence was highest in children younger than 18 months, an age at which...

  8. FISH PRODUCTION WORLDWIDE

    Directory of Open Access Journals (Sweden)

    Georgiana Melania COSTAICHE

    2014-12-01

    Full Text Available Fishing is one of the oldest occupations, which over the years has gone through several stages. In the economic terms the increase in intensive industrial system of the fish is advantageous because the specific energy consumption is low, given that they not need to maintain body temperature at high temperatures. Having regard to demographic trends in continue increasing, and the tendency of decrease fisheries leads to increased the production of aquaculture fish by order to ensure enough quantity and quality. The purpose of this paper is to highlight the evolution of fish production worldwide and in particular to show the evolution of production of fish from fisheries and aquaculture. To highlight the evolution global fish production given two ways to get fish respectively from aquaculture and fisheries, that have used data from FAOSTAT for 2007-2012. Also we can see that approximately 90% of the fish production is fished in the sea and only 10% in the territorial waters. The fish production in Africa had an ascending trend in the period under review. Analyzing fish production the share of total world continents is noted that Asia has a share of 68% in 2007 and increase to 73% in 2012.

  9. New worldwide lipid guidelines.

    Science.gov (United States)

    Saraf, Smriti; Ray, Kausik K

    2015-07-01

    Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of morbidity and mortality in most countries. Modification of common risk factors such as dyslipidaemia can result in significant reduction of ASCVD incidence in the population and improve clinical outcomes. The purpose of this review is to discuss and compare the latest worldwide lipid guidelines, and to demonstrate the variation in practice in different parts of the world. The lipid guidelines have recently been updated in different countries. The National Institute for Health and Care Excellence (NICE) guidelines in the United Kingdom were issued in July 2014, are risk based and are broadly similar to the American College of Cardiology/American Heart Association task force guidelines that were published in November 2013. Both these guidelines are in variance with both the Canadian Guidelines and the European Society of Cardiology/European Atherosclerosis Society guidelines 2011, which are target based and have different risk scoring systems, which results in significant variation in practice and increased healthcare costs in certain countries. The difference in guidelines in different countries makes it difficult for the clinician to standardize the treatment provided to individuals. The variance in risk scoring systems makes it difficult to compare risk prediction tools across countries and hence the optimum treatment available for a given population. Standardization of guidelines based on randomized controlled trial data and validation and calibration of various risk scoring systems could help improve clinical outcomes in this high-risk group of individuals at risk of ASCVD within individual countries.

  10. Influence of Media on Seasonal Influenza Epidemic Curves.

    Science.gov (United States)

    Saito, Satoshi; Saito, Norihiro; Itoga, Masamichi; Ozaki, Hiromi; Kimura, Toshiyuki; Okamura, Yuji; Murakami, Hiroshi; Kayaba, Hiroyuki

    2016-09-01

    Theoretical investigations predicting the epidemic curves of seasonal influenza have been demonstrated so far; however, there is little empirical research using ever accumulated epidemic curves. The effects of vaccine coverage and information distribution on influenza epidemics were evaluated. Four indices for epidemics (i.e., onset-peak duration, onset-end duration, ratio of the onset-peak duration to onset-end duration and steepness of epidemic curves) were defined, and the correlations between these indices and anti-flu drug prescription dose, vaccine coverage, the volume of media and search trend on influenza through internet were analyzed. Epidemiological data on seasonal influenza epidemics from 2002/2003 to 2013/2014 excluding 2009/2010 season were collected from National Institute of Infectious Diseases of Japan. The onset-peak duration and its ratio to onset-end duration correlated inversely with the volume of anti-flu drug prescription. Onset-peak duration correlated positively with media information volume on influenza. The steepness of the epidemic curve, and anti-flu drug prescription dose inversely correlated with the volume of media information. Pre-epidemic search trend and media volume on influenza correlated with the vaccine coverage in the season. Vaccine coverage had no strong effect on epidemic curve. Education through media has an effect on the epidemic curve of seasonal influenza. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  11. Epidemic Spreading in Random Rectangular Networks

    CERN Document Server

    Estrada, Ernesto; Moreno, Yamir

    2015-01-01

    Recently, Estrada and Sheerin (Phys. Rev. E 91, 042805 (2015)) developed the random rectangular graph (RRG) model to account for the spatial distribution of nodes in a network allowing the variation of the shape of the unit square commonly used in random geometric graphs (RGGs). Here, we consider an epidemics dynamics taking place on the nodes and edges of an RRG and we derive analytically a lower bound for the epidemic threshold for a Susceptible-Infected-Susceptible (SIS) or Susceptible-Infected-Recovered (SIR) model on these networks. Using extensive numerical simulations of the SIS dynamics we show that the lower bound found is very tight. We conclude that the elongation of the area in which the nodes are distributed makes the network more resilient to the propagation of an epidemics due to the fact that the epidemic threshold increases with the elongation of the rectangle. On the other hand, using the "classical" RGG for modeling epidemics on non-squared cities generates a larger error due to the effects...

  12. Worldwide prevalence of hypospadias.

    Science.gov (United States)

    Springer, A; van den Heijkant, M; Baumann, S

    2016-06-01

    Hypospadias is a common congenital malformation. Surgical repair and management of the long-term consequences require a substantial amount of socioeconomic resources. It is generally accepted that genetic and environmental factors play a major role in the etiology of hypospadias. There have been contradictory reports on rising hypospadias rates, and regional and ethnical differences. The exact prevalence of hypospadias is of major interest for healthcare providers, clinical medicine, and research. To review the literature regarding the worldwide prevalence of hypospadias. Pubmed, EMBASE and Google were systematically screened for: hypospadias, congenital malformation, anomaly, incidence, prevalence, and epidemiology. Exclusion criteria were surgical and risk-factor studies. To give an additional comprehensive overview, prevalence data were harvested from the Annual Report of the International Clearinghouse Centre for Birth Defects Surveillance and Research. Prevalence was reported as per 10,000 live births. Data were available from 1910 to 2013. The median study period was 9 years (range: 1-36 years). Approximately 90,255,200 births have been screened in all studies. The mean prevalence were: Europe 19.9 (range: 1-464), North America 34.2 (6-129.8), South America 5.2 (2.8-110), Asia 0.6-69, Africa 5.9 (1.9-110), and Australia 17.1-34.8. There were major geographical, regional, and ethnical differences, with an extreme heterogeneity of published studies. Numerous studies showed an increasing prevalence; on the other hand, there were a lot of contradictory data on the prevalence of hypospadias. The summary table shows contradictory data from the five largest international studies available. There was huge literature available on the prevalence of hypospadias. Most data derived from Europe and North America. Many methodological factors influenced the calculation of an accurate prevalence, and even more of the true changes in prevalence over time (no generally accepted

  13. Forecast and control of epidemics in a globalized world.

    Science.gov (United States)

    Hufnagel, L; Brockmann, D; Geisel, T

    2004-10-19

    The rapid worldwide spread of severe acute respiratory syndrome demonstrated the potential threat an infectious disease poses in a closely interconnected and interdependent world. Here we introduce a probabilistic model that describes the worldwide spread of infectious diseases and demonstrate that a forecast of the geographical spread of epidemics is indeed possible. This model combines a stochastic local infection dynamics among individuals with stochastic transport in a worldwide network, taking into account national and international civil aviation traffic. Our simulations of the severe acute respiratory syndrome outbreak are in surprisingly good agreement with published case reports. We show that the high degree of predictability is caused by the strong heterogeneity of the network. Our model can be used to predict the worldwide spread of future infectious diseases and to identify endangered regions in advance. The performance of different control strategies is analyzed, and our simulations show that a quick and focused reaction is essential to inhibiting the global spread of epidemics.

  14. Configuring the autism epidemic

    DEFF Research Database (Denmark)

    Seeberg, Jens; Christensen, Fie Lund Lindegaard

    2017-01-01

    Autism has been described as an epidemic, but this claim is contested and may point to an awareness epidemic, i.e. changes in the definition of what autism is and more attention being invested in diagnosis leading to a rise in registered cases. The sex ratio of children diagnosed with autism...... is skewed in favour of boys, and girls with autism tend to be diagnosed much later than boys. Building and further developing the notion of ‘configuration’ of epidemics, this article explores the configuration of autism in Denmark, with a particular focus on the health system and social support to families...... with children diagnosed with autism, seen from a parental perspective. The article points to diagnostic dynamics that contribute to explaining why girls with autism are not diagnosed as easily as boys. We unfold these dynamics through the analysis of a case of a Danish family with autism....

  15. Configuring the autism epidemic

    DEFF Research Database (Denmark)

    Christensen, Fie Lund Lindegaard; Seeberg, Jens

    2017-01-01

    is skewed in favour of boys, and girls with autism tend to be diagnosed much later than boys. Building and further developing the notion of ‘configuration’ of epidemics, this article explores the configuration of autism in Denmark, with a particular focus on the health system and social support to families...... with children diagnosed with autism, seen from a parental perspective. The article points to diagnostic dynamics that contribute to explaining why girls with autism are not diagnosed as easily as boys. We unfold these dynamics through the analysis of a case of a Danish family with autism.......Autism has been described as an epidemic, but this claim is contested and may point to an awareness epidemic, i.e. changes in the definition of what autism is and more attention being invested in diagnosis leading to a rise in registered cases. The sex ratio of children diagnosed with autism...

  16. Equipment and services for worldwide applications

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The report presents a digest of geothermal energy technology. The worldwide distribution of geothermal resources is described, and the degree to which various countries are exploiting their resources estimated. Detailed information about US technologies is presented, from exploration through applications to cost factors. (ACR)

  17. Discrete epidemic models.

    Science.gov (United States)

    Brauer, Fred; Feng, Zhilan; Castillo-Chavez, Carlos

    2010-01-01

    The mathematical theory of single outbreak epidemic models really began with the work of Kermack and Mackendrick about decades ago. This gave a simple answer to the long-standing question of why epidemics woould appear suddenly and then disappear just as suddenly without having infected an entire population. Therefore it seemed natural to expect that theoreticians would immediately proceed to expand this mathematical framework both because the need to handle recurrent single infectious disease outbreaks has always been a priority for public health officials and because theoreticians often try to push the limits of exiting theories. However, the expansion of the theory via the inclusion of refined epidemiological classifications or through the incorporation of categories that are essential for the evaluation of intervention strategies, in the context of ongoing epidemic outbreaks, did not materialize. It was the global threat posed by SARS in that caused theoreticians to expand the Kermack-McKendrick single-outbreak framework. Most recently, efforts to connect theoretical work to data have exploded as attempts to deal with the threat of emergent and re-emergent diseases including the most recent H1N1 influenza pandemic, have marched to the forefront of our global priorities. Since data are collected and/or reported over discrete units of time, developing single outbreak models that fit collected data naturally is relevant. In this note, we introduce a discrete-epidemic framework and highlight, through our analyses, the similarities between single-outbreak comparable classical continuous-time epidemic models and the discrete-time models introduced in this note. The emphasis is on comparisons driven by expressions for the final epidemic size.

  18. Long-term follow-up of acute Q fever patients after a large epidemic

    NARCIS (Netherlands)

    Wielders, CCH

    2014-01-01

    Between 2007 and 2009, one of the largest Q fever epidemics documented worldwide occurred in the Netherlands. This epidemic originated from dairy goat farms and resulted in over 3,500 notified human acute Q fever cases. After an episode of acute Q fever, the causative bacterium Coxiella burnetii may

  19. Evaluation of the spatial and temporal distribution of and risk factors for Bluetongue serotype 1 epidemics in sheep Extremadura (Spain), 2007-2011.

    Science.gov (United States)

    Pascual-Linaza, Ana V; Martínez-López, Beatriz; Pfeiffer, Dirk U; Moreno, José Carlos; Sanz, Cristina; Sánchez-Vizcaíno, José Manuel

    2014-10-01

    Extremadura has been one of the regions in Spain most severely affected by Bluetongue (BT) epidemics. The first incursion of BTV, which was successfully eradicated one year later, occurred in 2004, involving the BTV-serotype 4. However, a second incursion occurred in September 2007, this time involving serotype 1. Since then, the implementation of intensive vaccination programs have significantly reduced BTV-1 occurrence, but the disease has not been completely eradicated yet. This study aimed to provide, for the first time, a complete description of the spatial and temporal patterns of BTV-1 occurrence in sheep in Extremadura from 2007 to 2011 and to identify the risk factors that contributed to the seasonal occurrence of BTV-1 in this region. The results showed that risk factors contributing to BTV-1 occurrence in sheep changed between 2007 and 2011. Initially, when the population was still immunologically naïve, the main risk factors for BTV-1 occurrence were extensive management practices, large sheep farms and Culicoides abundance on farms. However, after the implementation of vaccination, other factors became more relevant for BTV-1 occurrence, mostly related to BTV reservoirs, such as the proximity of cattle farms or the introduction of cattle into farms. The Talaverana sheep breed also seemed to be associated with a significantly higher risk of BTV-1 occurrence, although it may be due to confounding factors, such as the geographical concentration of where this breed is kept and/or management practises used for this breed. The results of this study suggest that preventive and control strategies, including vaccination and active surveillance strategies, should be primarily focused on cattle farms kept in close vicinity to sheep flocks as well as in high-risk sheep farms (i.e. farms with a large farm size keeping both cattle and sheep and with a high number of animal introductions). Methods and results presented here may be used to guide decisions for the

  20. Epidemic extinction paths in complex networks

    Science.gov (United States)

    Hindes, Jason; Schwartz, Ira B.

    2017-05-01

    We study the extinction of long-lived epidemics on finite complex networks induced by intrinsic noise. Applying analytical techniques to the stochastic susceptible-infected-susceptible model, we predict the distribution of large fluctuations, the most probable or optimal path through a network that leads to a disease-free state from an endemic state, and the average extinction time in general configurations. Our predictions agree with Monte Carlo simulations on several networks, including synthetic weighted and degree-distributed networks with degree correlations, and an empirical high school contact network. In addition, our approach quantifies characteristic scaling patterns for the optimal path and distribution of large fluctuations, both near and away from the epidemic threshold, in networks with heterogeneous eigenvector centrality and degree distributions.

  1. Epidemic and Cascading Survivability of Complex Networks

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2014-01-01

    Our society nowadays is governed by complex networks, examples being the power grids, telecommunication networks, biological networks, and social networks. It has become of paramount importance to understand and characterize the dynamic events (e.g. failures) that might happen in these complex...... networks. For this reason, in this paper, we propose two measures to evaluate the vulnerability of complex networks in two different dynamic multiple failure scenarios: epidemic-like and cascading failures. Firstly, we present epidemic survivability ( ES ), a new network measure that describes...... the vulnerability of each node of a network under a specific epidemic intensity. Secondly, we propose cascading survivability ( CS ), which characterizes how potentially injurious a node is according to a cascading failure scenario. Then, we show that by using the distribution of values obtained from ES and CS...

  2. Epidemic and Cascading Survivability of Complex Networks

    CERN Document Server

    Manzano, Marc; Ripoll, Jordi; Fagertun, Anna Manolova; Torres-Padrosa, Victor; Pahwa, Sakshi; Scoglio, Caterina

    2014-01-01

    Our society nowadays is governed by complex networks, examples being the power grids, telecommunication networks, biological networks, and social networks. It has become of paramount importance to understand and characterize the dynamic events (e.g. failures) that might happen in these complex networks. For this reason, in this paper, we propose two measures to evaluate the vulnerability of complex networks in two different dynamic multiple failure scenarios: epidemic-like and cascading failures. Firstly, we present \\emph{epidemic survivability} ($ES$), a new network measure that describes the vulnerability of each node of a network under a specific epidemic intensity. Secondly, we propose \\emph{cascading survivability} ($CS$), which characterizes how potentially injurious a node is according to a cascading failure scenario. Then, we show that by using the distribution of values obtained from $ES$ and $CS$ it is possible to describe the vulnerability of a given network. We consider a set of 17 different compl...

  3. Obesity and kidney disease: hidden consequences of the epidemic ...

    African Journals Online (AJOL)

    Obesity has become a worldwide epidemic, and its prevalence has been projected to grow by 40% in the next decade. This increasing prevalence has implications for the risk of diabetes, cardiovascular disease and also for Chronic Kidney Disease. A high body mass index is one of the strongest risk factors for new-onset ...

  4. Obesity and kidney disease: hidden consequences of the epidemic ...

    African Journals Online (AJOL)

    Obesity has become a worldwide epidemic, and its prevalence has been projected to grow by 40% in the next decade. This increasing prevalence has implications for the risk of diabetes, cardiovascular disease and also for chronic kidney disease. A high body mass index is one of the strongest risk factors for new-onset ...

  5. Obesity and kidney disease: hidden consequences of the epidemic

    African Journals Online (AJOL)

    Obesity has become a worldwide epidemic, and its prevalence has been projected to grow by 40% in the next decade. This increasing prevalence has implications for the risk of diabetes, cardiovascular disease and also for chronic kidney disease. A high body mass index is one of the strongest risk factors for new-onset ...

  6. Antiretroviral Medication Adherence During The Ebola Epidemic In ...

    African Journals Online (AJOL)

    The 2014 Ebola outbreak is the largest in history and the first in West Africa. The outbreak affected multiple countries in West Africa. Worldwide, there have been 28,639 cases of Ebola virus disease and 11,316 deaths at 13 March 2016 in the world's worst recorded Ebola epidemic in Guinea, Liberia, and Sierra Leone.

  7. Using a Human Ecosystems Approach to the Obesity Epidemic

    Science.gov (United States)

    Painter, James E.; Painter, Rosemary; Wang, Xinyue; Schuster, Margaret

    2017-01-01

    Obesity has been increasing in all age groups worldwide for the past several decades. Yet for hundreds of years before the last quarter of the 20th century, obesity was not an issue. The etiology and the cure for the obesity epidemic have been elusive. Weight reduction diets and behavior therapy have not produced the desired results. Perhaps…

  8. Combating cholera epidemics by targeting reservoirs of infection ...

    African Journals Online (AJOL)

    Data synthesis: Information on cholera epidemics worldwide and in Kenya is synchronized under the headings; Introduction, History and predisposing factors, Current situation, Bioecology and transmission patterns, and, Use of molecular epidemiological and geographic information system (GIS) techniques in mapping out ...

  9. Socio-Demographic Variables Associated With Aids Epidemic ...

    African Journals Online (AJOL)

    Socio-Demographic Variables Associated With Aids Epidemic: Evidence From The Organization For Economic Cooperation And Development And The African Countries. ... The Human Immunodeficiency Virus (HIV) has been spreading rapidly worldwide for the past two decades, causing a variety of symptoms known as ...

  10. Kanpur epidemic: Time course

    Indian Academy of Sciences (India)

    The first peak was related to water contamination which began in December 1990. The second peak was related to failure of municipal authorities to chlorinate water during the 2nd week of February 1991. The epidemic came under control quickly after water contamination was controlled, providing confirmation for role of ...

  11. The Obesity Epidemic

    Centers for Disease Control (CDC) Podcasts

    2011-07-18

    Learn about obesity and the community initiatives taking place to prevent and reduce this epidemic.  Created: 7/18/2011 by National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition, Physical Activity and Obesity.   Date Released: 7/18/2011.

  12. Global HIV/AIDS Epidemic

    Science.gov (United States)

    ... Policy The Global HIV/AIDS Epidemic The Global HIV/AIDS Epidemic Published: Nov 29, 2017 Facebook Twitter ... 2001-FY 2018 Request The Global Response to HIV/AIDS International efforts to combat HIV began in ...

  13. The worldwide ionospheric data base

    Science.gov (United States)

    Bilitza, Dieter

    1989-01-01

    The worldwide ionospheric data base is scattered over the entire globe. Different data sets are held at different institutions in the U.S., U.S.S.R., Australia, Europe, and Asia. The World Data Centers on the different continents archive and distribute part of the huge data base; the scope and cross section of the individual data holdings depend on the regional and special interest of the center. An attempt is made to pull together all the strings that point toward different ionospheric data holdings. Requesters are provided with the information about what is available and where to get it. An attempt is also made to evaluate the reliability and compatibility of the different data sets based on the consensus in the ionospheric research community. The status and accuracy of the standard ionospheric models are also discussed because they may facilitate first order assessment of ionospheric effects. This is a first step toward an ionospheric data directory within the framework of NSSDC's master directory.

  14. Epidemics on interconnected networks

    Science.gov (United States)

    Dickison, Mark; Havlin, S.; Stanley, H. E.

    2012-06-01

    Populations are seldom completely isolated from their environment. Individuals in a particular geographic or social region may be considered a distinct network due to strong local ties but will also interact with individuals in other networks. We study the susceptible-infected-recovered process on interconnected network systems and find two distinct regimes. In strongly coupled network systems, epidemics occur simultaneously across the entire system at a critical infection strength βc, below which the disease does not spread. In contrast, in weakly coupled network systems, a mixed phase exists below βc of the coupled network system, where an epidemic occurs in one network but does not spread to the coupled network. We derive an expression for the network and disease parameters that allow this mixed phase and verify it numerically. Public health implications of communities comprising these two classes of network systems are also mentioned.

  15. Temperature profiles from XBT casts from a world-wide distribution from the TAI HE and other platforms from 08 November 2000 to 18 April 2001 (NODC Accession 0000442)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT and other data were collected world-wide from the TAI HE and other platforms from 08 November 2000 to 18 April 2001. Data include temperature profiles. Data are...

  16. Resilience of epidemics on networks

    CERN Document Server

    Lu, Dan; Zhang, Jiaquan; Wang, Huijuan; Li, Daqing

    2016-01-01

    Epidemic propagation on complex networks has been widely investigated, mostly with invariant parameters. However, the process of epidemic propagation is not always constant. Epidemics can be affected by various perturbations, and may bounce back to its original state, which is considered resilient. Here, we study the resilience of epidemics on networks, by introducing a different infection rate ${\\lambda_{2}}$ during SIS (susceptible-infected-susceptible) epidemic propagation to model perturbations (control state), whereas the infection rate is ${\\lambda_{1}}$ in the rest of time. Through simulations and theoretical analysis, we find that even for ${\\lambda_{2}<\\lambda_{c}}$, epidemics eventually could bounce back if control duration is below a threshold. This critical control time for epidemic resilience, i.e., ${cd_{max}}$ can be predicted by the diameter (${d}$) of the underlying network, with the quantitative relation ${cd_{max}\\sim d^{\\alpha}}$. Our findings can help to design a better mitigation stra...

  17. Connecting the obesity and the narcissism epidemics.

    Science.gov (United States)

    Lemaitre, Bruno

    2016-10-01

    Obesity and metabolic syndromes are major threats to health in both developed and developing countries. This opinion article is a holistic attempt to understand the obesity epidemic, by connecting it to the widespread narcissism in society. The narcissism epidemic refers to an increased prevalence of status-striving individualism and a decreased sense of community, observed in Westerns populations and spreading worldwide. Based on social personality and evolutionary psychology approaches, I speculate that this rise of narcissism underlies a steep social hierarchy resulting in increase of social stress. This social stress markedly affects individuals who are sensitive to social hierarchy dominance due to their personality, yet are relegated at a lower social position. I speculate that over-eating is one major mechanism for coping with this stress, and discuss the possibility that visceral fat may constitute an adaptive behaviour to the lower social hierarchy position, which is perceived as unjust. Connecting the prevalence of obesity to the narcissism epidemic allows for a more thorough examination of factors, which contribute to obesity, which includes early difficult childhood experience, lower rank, and the overall competitive framework of the society. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  18. Worldwide survey of absorption fluids data

    Energy Technology Data Exchange (ETDEWEB)

    Macriss, R.A.; Zawacki, T.S.

    1988-01-01

    The overall objective of this study is to develop improved data for the thermodynamic, transport and physical properties of absorption fluids. A specific objective of this phase of the study is to compile, catalog and coarse-screen the available worldwide data of known absorption fluid systems and publish it as a reference document to be distributed to manufacturers, researchers and others active in absorption heat pump activities. 3 refs., 3 figs., 1 tab.

  19. Epidemic mechanisms of type A influenza.

    Science.gov (United States)

    Hope-Simpson, R E

    1979-08-01

    The antigenic varieties of influenza A virus isolated from 1968 to 1976 in a surveillance of a small, rather remote population were similar to those from England and Wales as a whole, despite frequent antigenic changes during the period. Household studies in the first two H3N2 influenza A epidemics found low attack rates within households, a high proportion (70%) of affected households with only one case of influenza, similar distributions of affected households in the two epidemics by the number of cases of influenza and similar distributions of the influenza cases by the day of their onset in the household outbreak. No serial interval could be demonstrated by cumulating household outbreaks. More than one minor variant was causing influenza contemporaneously in the same villages in several seasons, and different variants were on one occasion found on successive days in bedfellows. The regular occurrence of epidemics in winter was often accompanied by the disappearance of the epidemic variants and their replacement, after a virus-free interval, by new variants. These epidemiological findings seem best interpreted on the following tentative hypothesis. Influenza A sufferers do not transmit the virus during their illness; instead it rapidly becomes latent in their tissues so that they become symptomless carrier-hosts and develop specific immunity. Next season an extraneous seasonally mediated stimulus reactivates the latent virus residues so that the carrier-host becomes briefly infectious, though symptomless. Antigenic drift occurs because particles reconstituted to be identical with the progenitor virus cannot escape the specific immunity it has provoked in the carrier host. He can shed only mutants also determined by the progenitor virus. From the assortment of mutants shed by the carrier-host, his non-immune companions select that (those) which is best fitted to survive, and it rapidly causes influenzal illness. Epidemics consist largely or entirely of such

  20. The epidemic of methylisothiazolinone

    DEFF Research Database (Denmark)

    Schwensen, Jakob F; Uter, Wolfgang; Bruze, Magnus

    2017-01-01

    BACKGROUND: The use of methylisothiazolinone (MI) in cosmetic products has caused an unprecedented epidemic of MI contact allergy. Current data concerning exposures at a European level are required. OBJECTIVES: To describe demographics and MI exposures for European patients with MI contact allerg....... Fifteen patients (7.3%) had previously experienced allergic reactions when they were in newly painted rooms. CONCLUSION: Clinically relevant MI contact allergy remains prevalent across European countries, mainly because of exposure to rinse-off and leave-on cosmetic products....

  1. [A manufacture method of schistosomiasis epidemic maps based on Google Earth].

    Science.gov (United States)

    Wang, Wei-Chun; Zhan, Ti; Zhu, Ying-Fu

    2014-02-01

    To make various schistosomiasis epidemic maps based on Google Earth. The various elements for schistosomiasis epidemic maps were marked in the Google Earth platform by adding the place mark, path, polygon, overlay and so on. Various schistosomiasis epidemic maps were produced and saved, such as the schistosomiasis epidemic area map of the city, the map of Oncomelania hupensis snail distribution in the town, and the schematic map of snail environments. The schistosomiasis epidemic maps based on Google Earth are clear and visual. The production process is very simple and easy to learn. It is suitable for the use in the grass-root schistosomiasis control stations.

  2. Aging Education: A Worldwide Imperative

    Science.gov (United States)

    McGuire, Sandra L.

    2017-01-01

    Life expectancy is increasing worldwide. Unfortunately, people are generally not prepared for this long life ahead and have ageist attitudes that inhibit maximizing the "longevity dividend" they have been given. Aging education can prepare people for life's later years and combat ageism. It can reimage aging as a time of continued…

  3. Hepatitis E epidemics in India

    Indian Academy of Sciences (India)

    We compiled this slide in 1992. It shows dates, locations and number of cases for various epidemics reported from different parts of India till that time. The first well recorded epidemic was in 1955-56 here in Delhi with nearly 30000 cases. Large outbreaks occurred in 1978 in Kashmir. My interest in this disease began in ...

  4. Epidemics after Natural Disasters

    Science.gov (United States)

    Gayer, Michelle; Connolly, Maire A.

    2007-01-01

    The relationship between natural disasters and communicable diseases is frequently misconstrued. The risk for outbreaks is often presumed to be very high in the chaos that follows natural disasters, a fear likely derived from a perceived association between dead bodies and epidemics. However, the risk factors for outbreaks after disasters are associated primarily with population displacement. The availability of safe water and sanitation facilities, the degree of crowding, the underlying health status of the population, and the availability of healthcare services all interact within the context of the local disease ecology to influence the risk for communicable diseases and death in the affected population. We outline the risk factors for outbreaks after a disaster, review the communicable diseases likely to be important, and establish priorities to address communicable diseases in disaster settings. PMID:17370508

  5. The relationship between human behavior and the process of epidemic spreading in a real social network

    Science.gov (United States)

    Grabowski, A.; Rosińska, M.

    2012-07-01

    On the basis of experimental data on interactions between humans we have investigated the process of epidemic spreading in a social network. We found that the distribution of the number of contacts maintained in one day is exponential. Data on frequency and duration of interpersonal interactions are presented. They allow us to simulate the spread of droplet-/-air-borne infections and to investigate the influence of human dynamics on the epidemic spread. Specifically, we investigated the influence of the distribution of frequency and duration of those contacts on magnitude, epidemic threshold and peak timing of epidemics propagating in respective networks. It turns out that a large increase in the magnitude of an epidemic and a decrease in epidemic threshold are visible if and only if both are taken into account. We have found that correlation between contact frequency and duration strongly influences the effectiveness of control measures like mass immunization campaigns.

  6. Diabesity: an overview of a rising epidemic.

    Science.gov (United States)

    Farag, Youssef M K; Gaballa, Mahmoud R

    2011-01-01

    'Diabesity' is the term for diabetes occurring in the context of obesity. In this review, we will overview the latest epidemiological data available describing the rising prevalence, health impact and economic impact of diabesity. We will also outline the measures required to slowdown this newly evolving epidemic. The global prevalence of diabetes in 2010 was 284 million people worldwide constituting around 6.4% of the world population, which is higher than was projected in earlier studies. Furthermore, the projections for 2030 show the prevalence to reach 439 million individuals comprising ~7.7% of the world population. The burden of diabetes on the world economy has been rising steadily in the last decade to reach $376 billion in 2010 and is expected to reach $490 billion in 2030. Diabesity represents a substantial economic burden as reflected by diabetes and obesity consuming 14 and 5.7% of the USA's total health expenditure, respectively, representing the highest known expenditure on diabesity worldwide. When costs associated with being overweight were also included, the upper limit of obesity expenditure rises to 9.1% of the USA's total healthcare expenditure. The highest recorded expenditure on diabetes alone was in Saudi Arabia consuming 21% of the country's total health expenditure, with no data available about the health expenditure on obesity. The health impact of diabesity is substantial to include long-term diabetic complications, reduction in health-related functioning, reduction of quality of life and reduced overall life expectancy. Long-term complications include myocardial infarction, cerebrovascular stroke and end-stage renal disease. Also recent advances have found that there is an association between chronic stress, depression and sleeping troubles to both diabetes and obesity. This century is the unprecedented diabetogenic era in human history. It is thus urgent to take steps including screening, prevention and early management in an attempt to

  7. The epidemic of distraction.

    Science.gov (United States)

    Weksler, Marc E; Weksler, Babette B

    2012-01-01

    Multitasking is a rapidly growing phenomenon affecting all segments of the population but is rarely as successful as its proponents believe. The use of mobile electronic devices contributes importantly to multitasking and cognitive overload. Although personal electronic devices provide many benefits, their adverse effects are frequently overlooked. Personal observation and a review of the scientific literature supports the view that overuse or misuse of personal electronic devices promotes cognitive overload, impairs multitasking and lowers performance at all ages but particularly in the elderly. This phenomenon appears to be rapidly increasing and threatens to become a tsunami as spreading electronic waves cause an 'epidemic of distraction'. Mobile electronic devices often bring benefits to their users in terms of rapid access to information. However, there is a dark side to the increasing addiction to these devices that challenges the health and well-being of the entire population, targeting, in particular, the aged and infirm. New approaches to information gathering can foster creativity if cognitive overload is avoided. Copyright © 2012 S. Karger AG, Basel.

  8. Wood-burning stoves worldwide

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo

    More than any time in our history, the wood-burning stove continues to be the most popular technology used for cooking and heating worldwide. According to the World Health Organization and recent scientific studies, the inefficient use of solid-fuels in traditional stoves constitutes the major...... systems, improved efficient retrofits and advanced stove innovations. In chapter 3, four popular wood-burning practices found in five countries were singled-out to be examined closely in four case studies: “cooking in Brazil”, “cooking and heating in Peru”, “heating in Portugal” and “recreational heat...

  9. Epidemic of neurolathyrism in Ethiopia.

    Science.gov (United States)

    Getahun, H; Mekonnen, A; TekleHaimanot, R; Lambein, F

    1999-07-24

    After a drought and famine, overconsumption of the drought-tolerant grasspea triggered an epidemic of neurodegenerative neurolathyrism in Northeast Ethiopia. Environmental, nutritional, and medical factors seem to affect the susceptibility.

  10. Temperature profile, oxygen, phosphate and other data collected using bottle from multiple platforms in a World-wide distribution from 24 June 1934 to 24 August 1984 (NODC Accession 0002144)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and other data were collected using bottle casts from multiple platforms in a world wide distribution. Data were collected from 24 June 1934 to...

  11. Space Research Fortifies Nutrition Worldwide

    Science.gov (United States)

    2008-01-01

    NASA's Controlled Ecological Life Support Systems program attempted to address basic needs of crews, meet stringent payload and power usage restrictions, and minimize space occupancy, by developing living, regenerative ecosystems that would take care of themselves and their inhabitants. An experiment from this program evolved into one of the most widespread NASA spinoffs of all time-a method for manufacturing an algae-based food supplement that provides the nutrients previously only available in breast milk. Martek Biosciences Corporation, in Columbia, Maryland, now manufactures this supplement, and it can be found in over 90 percent of the infant formulas sold in the United States, as well as those sold in over 65 other countries. With such widespread use, the company estimates that over 24 million babies worldwide have consumed its nutritional additives.

  12. Stationary power fuel cell commercialization status worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M.C. [Dept. of Energy, Morgantown, WV (United States)

    1996-12-31

    Fuel cell technologies for stationary power are set to play a role in power generation applications worldwide. The worldwide fuel cell vision is to provide powerplants for the emerging distributed generation and on-site markets. Progress towards commercialization has occurred in all fuel cell development areas. Around 100 ONSI phosphoric acid fuel cell (PAFC) units have been sold, with significant foreign sales in Europe and Japan. Fuji has apparently overcome its PAFC decay problems. Industry-driven molten carbonate fuel cell (MCFC) programs in Japan and the U.S. are conducting megawatt (MW)-class demonstrations, which are bringing the MCFC to the verge of commercialization. Westinghouse Electric, the acknowledged world leader in tubular solid oxide fuel cell (SOFC) technology, continues to set performance records and has completed construction of a 4-MW/year manufacturing facility in the U.S. Fuel cells have also taken a major step forward with the conceptual development of ultra-high efficiency fuel cell/gas turbine plants. Many SOFC developers in Japan, Europe, and North America continue to make significant advances.

  13. CMS Centres Worldwide a New Collaborative Infrastructure

    CERN Document Server

    Taylor, Lucas

    2009-01-01

    The CMS Experiment at the LHC is establishing a global network of inter-connected "CMS Centres" for controls, operations and monitoring. These support: (1) CMS data quality monitoring, detector calibrations, and analysis; and (2) computing operations for the processing, storage and distribution of CMS data. We describe the infrastructure, computing, software, and communications systems required to create an effective and affordable CMS Centre. We present our highly successful operations experiences with the major CMS Centres at CERN, Fermilab, and DESY during the LHC first beam data-taking and cosmic ray commissioning work. The status of the various centres already operating or under construction in Asia, Europe, Russia, South America, and the USA is also described. We emphasise the collaborative communications aspects. For example, virtual co-location of experts in CMS Centres Worldwide is achieved using high-quality permanently-running "telepresence" video links. Generic Web-based tools have been developed ...

  14. A simple SIS epidemic model with a backward bifurcation.

    Science.gov (United States)

    van den Driessche, P; Watmough, J

    2000-06-01

    It is shown that an SIS epidemic model with a non-constant contact rate may have multiple stable equilibria, a backward bifurcation and hysteresis. The consequences for disease control are discussed. The model is based on a Volterra integral equation and allows for a distributed infective period. The analysis includes both local and global stability of equilibria.

  15. Understanding the epidemic of HIV in South Africa

    African Journals Online (AJOL)

    the epidemic. The age-dependent force of infection indicates how the risk of infection varies across age groups. ... distributions, which are especially important when the numbers are small. Estimating the asymptotic ..... (US Bureau of Census, Population Division, International. Programmes Center, HIVlAIDS Surveillance ...

  16. Euthanasia and related practices worldwide.

    Science.gov (United States)

    Kelleher, M J; Chambers, D; Corcoran, P; Keeley, H S; Williamson, E

    1998-01-01

    The present paper examines the occurrence of matters relating to the ending of life, including active euthanasia, which is, technically speaking, illegal worldwide. Interest in this most controversial area is drawn from many varied sources, from legal and medical practitioners to religious and moral ethicists. In some countries, public interest has been mobilized into organizations that attempt to influence legislation relating to euthanasia. Despite the obvious international importance of euthanasia, very little is known about the extent of its practice, whether passive or active, voluntary or involuntary. This examination is based on questionnaires completed by 49 national representatives of the International Association for Suicide Prevention (IASP), dealing with legal and religious aspects of euthanasia and physician-assisted suicide, as well as suicide. A dichotomy between the law and medical practices relating to the end of life was uncovered by the results of the survey. In 12 of the 49 countries active euthanasia is said to occur while a general acceptance of passive euthanasia was reported to be widespread. Clearly, definition is crucial in making the distinction between active and passive euthanasia; otherwise, the entire concept may become distorted, and legal acceptance may become more widespread with the effect of broadening the category of individuals to whom euthanasia becomes an available option. The "slippery slope" argument is briefly considered.

  17. Application of electron accelerator worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo [Japan Atomic Industrial Forum, Inc., Tokyo (Japan)

    2003-02-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  18. Networked SIS Epidemics With Awareness

    KAUST Repository

    Paarporn, Keith

    2017-07-20

    We study a susceptible-infected-susceptible epidemic process over a static contact network where the nodes have partial information about the epidemic state. They react by limiting their interactions with their neighbors when they believe the epidemic is currently prevalent. A node\\'s awareness is weighted by the fraction of infected neighbors in their social network, and a global broadcast of the fraction of infected nodes in the entire network. The dynamics of the benchmark (no awareness) and awareness models are described by discrete-time Markov chains, from which mean-field approximations (MFAs) are derived. The states of the MFA are interpreted as the nodes\\' probabilities of being infected. We show a sufficient condition for the existence of a

  19. Environmental Factors Influencing Epidemic Cholera

    Science.gov (United States)

    Jutla, Antarpreet; Whitcombe, Elizabeth; Hasan, Nur; Haley, Bradd; Akanda, Ali; Huq, Anwar; Alam, Munir; Sack, R. Bradley; Colwell, Rita

    2013-01-01

    Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks. PMID:23897993

  20. Epidemic Network Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Katsikas, Dimitrios; Fagertun, Anna Manolova

    2013-01-01

    This paper presents a failure propagation model for transport networks which are affected by epidemic failures. The network is controlled using the GMPLS protocol suite. The Susceptible Infected Disabled (SID) epidemic model is investigated and new signaling functionality of GMPLS to support epid...... epidemic failure resolution is proposed. The results provide important input to service recovery mechanisms under epidemic failures.......This paper presents a failure propagation model for transport networks which are affected by epidemic failures. The network is controlled using the GMPLS protocol suite. The Susceptible Infected Disabled (SID) epidemic model is investigated and new signaling functionality of GMPLS to support...

  1. HIV epidemic in South Africa: A comparison of HIV epidemic ...

    African Journals Online (AJOL)

    2014-08-26

    Aug 26, 2014 ... 2Department of Statistics,. University of South Africa,. Pretoria, South ... antenatal care surveillance (ANC) surveys, we explored trends and patterns in HIV prevalence in KwaZulu-Natal and Western ... HIV infection in this age group is associated with recent infection, thus indicating an increasing epidemic in ...

  2. HIV epidemic in South Africa: A comparison of HIV epidemic ...

    African Journals Online (AJOL)

    2014-08-26

    Aug 26, 2014 ... and population-based surveys conducted in different years show a decline in HIV prevalence amongst youth in KwaZulu-Natal compared with an increase in the same age group in the Western Cape. HIV infection in this age group is associated with recent infection, thus indicating an increasing epidemic in ...

  3. The narcissism epidemic is dead : Long live the narcissism epidemic

    NARCIS (Netherlands)

    Wetzel, Eunike; Brown, Anna; Hill, Patrick; Chung, J.M.H.; Robins, R.W.; Roberts, B.W.

    2017-01-01

    Are recent cohorts of college students more narcissistic than their predecessors? To address debates about the so-called “narcissism epidemic,” we used data from three cohorts of students (N1990s = 1,166; N2000s = 33,647; N2010s = 25,412) to test whether narcissism levels (overall and specific

  4. Random migration processes between two stochastic epidemic centers.

    Science.gov (United States)

    Sazonov, Igor; Kelbert, Mark; Gravenor, Michael B

    2016-04-01

    We consider the epidemic dynamics in stochastic interacting population centers coupled by random migration. Both the epidemic and the migration processes are modeled by Markov chains. We derive explicit formulae for the probability distribution of the migration process, and explore the dependence of outbreak patterns on initial parameters, population sizes and coupling parameters, using analytical and numerical methods. We show the importance of considering the movement of resident and visitor individuals separately. The mean field approximation for a general migration process is derived and an approximate method that allows the computation of statistical moments for networks with highly populated centers is proposed and tested numerically. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Porcine Epidemic Diarrhea Virus Induces Autophagy to Benefit Its Replication

    Directory of Open Access Journals (Sweden)

    Xiaozhen Guo

    2017-03-01

    Full Text Available The new porcine epidemic diarrhea (PED has caused devastating economic losses to the swine industry worldwide. Despite extensive research on the relationship between autophagy and virus infection, the concrete role of autophagy in porcine epidemic diarrhea virus (PEDV infection has not been reported. In this study, autophagy was demonstrated to be triggered by the effective replication of PEDV through transmission electron microscopy, confocal microscopy, and Western blot analysis. Moreover, autophagy was confirmed to benefit PEDV replication by using autophagy regulators and RNA interference. Furthermore, autophagy might be associated with the expression of inflammatory cytokines and have a positive feedback loop with the NF-κB signaling pathway during PEDV infection. This work is the first attempt to explore the complex interplay between autophagy and PEDV infection. Our findings might accelerate our understanding of the pathogenesis of PEDV infection and provide new insights into the development of effective therapeutic strategies.

  6. On the use of human mobility proxies for modeling epidemics.

    Directory of Open Access Journals (Sweden)

    Michele Tizzoni

    2014-07-01

    Full Text Available Human mobility is a key component of large-scale spatial-transmission models of infectious diseases. Correctly modeling and quantifying human mobility is critical for improving epidemic control, but may be hindered by data incompleteness or unavailability. Here we explore the opportunity of using proxies for individual mobility to describe commuting flows and predict the diffusion of an influenza-like-illness epidemic. We consider three European countries and the corresponding commuting networks at different resolution scales, obtained from (i official census surveys, (ii proxy mobility data extracted from mobile phone call records, and (iii the radiation model calibrated with census data. Metapopulation models defined on these countries and integrating the different mobility layers are compared in terms of epidemic observables. We show that commuting networks from mobile phone data capture the empirical commuting patterns well, accounting for more than 87% of the total fluxes. The distributions of commuting fluxes per link from mobile phones and census sources are similar and highly correlated, however a systematic overestimation of commuting traffic in the mobile phone data is observed. This leads to epidemics that spread faster than on census commuting networks, once the mobile phone commuting network is considered in the epidemic model, however preserving to a high degree the order of infection of newly affected locations. Proxies' calibration affects the arrival times' agreement across different models, and the observed topological and traffic discrepancies among mobility sources alter the resulting epidemic invasion patterns. Results also suggest that proxies perform differently in approximating commuting patterns for disease spread at different resolution scales, with the radiation model showing higher accuracy than mobile phone data when the seed is central in the network, the opposite being observed for peripheral locations. Proxies

  7. Is the New Heroin Epidemic Really New? Racializing Heroin.

    Science.gov (United States)

    Bowser, Benjamin; Fullilove, Robert; Word, Carl

    2017-01-01

    Heroin abuse as an outcome of the prior use of painkillers increased rapidly over the past decade. This "new epidemic" is unique because the new heroin users are primarily young White Americans in rural areas of virtually every state. This commentary argues that the painkiller-to-heroin transition could not be the only cause of heroin use on such a scale and that the new and old heroin epidemics are linked. The social marketing that so successfully drove the old heroin epidemic has innovated and expanded due to the use of cell-phones, text messaging and the "dark web" which requires a Tor browser, and software that allows one to communicate with encrypted sites without detection. Central city gentrification has forced traffickers to take advantage of larger and more lucrative markets. A second outcome is that urban black and Latino communities are no longer needed as heroin stages areas for suburban and exurban illicit drug distribution. Drug dealing can be done directly in predominantly white suburbs and rural areas without the accompanying violence associated with the old epidemic. Denial of the link between the new and old heroin epidemics racially segregates heroin users and more proactive prevention and treatment in the new epidemic than in the old. It also cuts off a half-century of knowledge about the supply-side of heroin drug dealing and the inevitable public policy measures that will have to be implemented to effectively slow and stop both the old and new epidemic. Copyright © 2016 National Medical Association. Published by Elsevier Inc. All rights reserved.

  8. On the use of human mobility proxies for modeling epidemics.

    Science.gov (United States)

    Tizzoni, Michele; Bajardi, Paolo; Decuyper, Adeline; Kon Kam King, Guillaume; Schneider, Christian M; Blondel, Vincent; Smoreda, Zbigniew; González, Marta C; Colizza, Vittoria

    2014-07-01

    Human mobility is a key component of large-scale spatial-transmission models of infectious diseases. Correctly modeling and quantifying human mobility is critical for improving epidemic control, but may be hindered by data incompleteness or unavailability. Here we explore the opportunity of using proxies for individual mobility to describe commuting flows and predict the diffusion of an influenza-like-illness epidemic. We consider three European countries and the corresponding commuting networks at different resolution scales, obtained from (i) official census surveys, (ii) proxy mobility data extracted from mobile phone call records, and (iii) the radiation model calibrated with census data. Metapopulation models defined on these countries and integrating the different mobility layers are compared in terms of epidemic observables. We show that commuting networks from mobile phone data capture the empirical commuting patterns well, accounting for more than 87% of the total fluxes. The distributions of commuting fluxes per link from mobile phones and census sources are similar and highly correlated, however a systematic overestimation of commuting traffic in the mobile phone data is observed. This leads to epidemics that spread faster than on census commuting networks, once the mobile phone commuting network is considered in the epidemic model, however preserving to a high degree the order of infection of newly affected locations. Proxies' calibration affects the arrival times' agreement across different models, and the observed topological and traffic discrepancies among mobility sources alter the resulting epidemic invasion patterns. Results also suggest that proxies perform differently in approximating commuting patterns for disease spread at different resolution scales, with the radiation model showing higher accuracy than mobile phone data when the seed is central in the network, the opposite being observed for peripheral locations. Proxies should therefore be

  9. Worldwide Status of EUV Astronomy

    Science.gov (United States)

    Kowalski, Michael P.; Wood, K. S.; Barstow, M. A.

    2013-01-01

    The bulk of radiation from million-degree plasmas is emitted at EUV wavelengths, which include critical spectral features containing diagnostic information often not available at other wavelengths (e.g., He II Ly series 228-304 Å). Thus, EUV astrophysics (Barstow & Holberg 2003) presents opportunities for intriguing results obtainable with sensitive high-resolution spectroscopy and particularly applicable to hot plasmas in stellar coronae, white dwarfs and the interstellar medium. The US-built J-PEX spectrometer has flown twice on sounding rockets, observing and publishing results on two white dwarf targets (Cruddace et al. 2002, Barstow et al. 2005, Kowalski et al. 2011). Using multilayer-grating technology, J-PEX delivers both high effective area and the world's highest resolution in EUV, greater than Chandra at adjacent energies, but in a waveband Chandra cannot reach. However, the US program has been stalled by inability to obtain further NASA sounding rocket flights. A high level of technology readiness, plus important questions answerable solely with that technology, does not seem sufficient to win support. Nor is the substantial amount of resources invested into technology development over two decades, supported by NASA, DoD, and European partners. Proposals to turn the instrument or its technology into small satellite-based surveys have been made (results to be described) in the US and Europe, but the overall situation is precarious. The entire EUV astrophysics field is losing out on an opportunity, and is at risk of fading away, with forced discard of established assets. Only mobilization of the international EUV community -- unifying European, US, and perhaps others -- can reverse this situation. Our poster summarizes science quests within reach of proven technology, gives a current snapshot of that technology, and provides a summary of worldwide efforts to obtain necessary space access in NASA, ESA, and elsewhere. A process for building and maintaining

  10. Obesity and diabetes epidemics: cancer repercussions.

    Science.gov (United States)

    Hjartåker, Anette; Langseth, Hilde; Weiderpass, Elisabete

    2008-01-01

    The prevalence of overweight (body mass index, BMI, between 25 and 30 kg/m2) and obesity (BMI of 30 kg/m2 or higher) is increasing rapidly worldwide, especially in developing countries and countries undergoing economic transition to a market economy. One consequence of obesity is an increased risk of developing type II diabetes. Overall, there is considerable evidence that overweight and obesity are associated with risk for some of the most common cancers. There is convincing evidence of a positive association between overweight/obesity and risk for adenocarcinoma of the oesophagus and the gastric cardia, colorectal cancer, postmenopausal breast cancer, endometrial cancer and kidney cancer (renal-cell). Premenopausal breast cancer seems to be inversely related to obesity. For all other cancer sites the evidence of an association between overweight/obesity and cancer is inadequate, although there are studies suggesting an increased risk of cancers of the liver, gallbladder, pancreas, thyroid gland and in lymphoid and haematopoietic tissue. Far less is known about the association between diabetes mellitus type I (also called insulin dependent diabetes mellitus or juvenile diabetes), type II diabetes (called non-insulin dependent diabetes mellitus or adult onset diabetes mellitus) and cancer risk. The most common type of diabetes mellitus, type II, seems to be associated with liver and pancreas cancer and probably with colorectal cancer. Some studies suggest an association with endometrial and postmenopausal breast cancer. Studies reporting on the association between type I diabetes mellitus, which is relatively rare in most populations and cancer risk are scanty, but suggest a possible association with endometrial cancer. Overweight and obesity, as well as type II diabetes mellitus are largely preventable through changes in lifestyle. The fundamental causes of the obesity epidemic-and consequently the diabetes type II epidemic-are societal, resulting from an

  11. Bronchiolitis: Analysis of 10 consecutive epidemic seasons.

    Science.gov (United States)

    Cangiano, Giulia; Nenna, Raffaella; Frassanito, Antonella; Evangelisti, Melania; Nicolai, Ambra; Scagnolari, Carolina; Pierangeli, Alessandra; Antonelli, Guido; Papoff, Paola; Petrarca, Laura; Capocaccia, Paolo; Moretti, Corrado; Midulla, Fabio

    2016-12-01

    Bronchiolitis is the leading cause of hospitalization in infants under 12 months. Our aims were to analyze epidemiological characteristics of infants with bronchiolitis over 10 consecutive seasons and to evaluate whether there are any clinical differences between infants hospitalized for bronchiolitis during epidemic peak months and infants in non-peak months. We enrolled consecutive enrolled 723 previously healthy term infants hospitalized at the Paediatric Emergency Department, "Sapienza" University of Rome over the period 2004-2014. Fourteen respiratory viruses were detected from nasopharyngeal aspirates by molecular methods. Clinical and demographic data were extracted from clinical charts. Viruses were detected in 351 infants (48.5%): RSV in 234 (32.4%), RV in 44 (6.1%), hBoV in 11 (1.5%), hMPV in 12 (1.6%), co-infections in 39 (5.4%), and other viruses in 11 (1.5%). Analyzing the 10 epidemic seasons, we found higher incidence for bronchiolitis every 4 years with a peak during the months December-January. Infants hospitalized during peak months had lower family history for asthma (P = 0.003), more smoking mothers during pregnancy (P = 0.036), were slightly higher breastfed (0.056), had lower number of blood eosinophils (P = 0.015) and had a higher clinical severity score (P = 0.017). RSV was detected mostly during peak months, while RV was equally distributed during the seasons. We found some variations in bronchiolitis incidence during epidemics, and discriminative characteristics in infants hospitalized for bronchiolitis during peak months and in non-peak months, that might reflect two different populations of children. Pediatr Pulmonol. 2016;51:1330-1335. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination wit...

  13. A Framework for Epidemic Models

    NARCIS (Netherlands)

    Gielen, J.L.W.

    2003-01-01

    A framework is developed that enables the modeling of the various mechanisms of epidemic processes. A model within the framework is completely characterized by a set of transmission functions. These functions support the modeling of the infectivity of a new infective as a function of its

  14. Visual Mining of Epidemic Networks

    CERN Document Server

    Clémençon, Stéphan; Rossi, Fabrice; Tran, Viet Chi; 10.1007/978-3-642-21498-1_35

    2012-01-01

    We show how an interactive graph visualization method based on maximal modularity clustering can be used to explore a large epidemic network. The visual representation is used to display statistical tests results that expose the relations between the propagation of HIV in a sexual contact network and the sexual orientation of the patients.

  15. Stochastic Processes in Epidemic Theory

    CERN Document Server

    Lefèvre, Claude; Picard, Philippe

    1990-01-01

    This collection of papers gives a representative cross-selectional view of recent developments in the field. After a survey paper by C. Lefèvre, 17 other research papers look at stochastic modeling of epidemics, both from a theoretical and a statistical point of view. Some look more specifically at a particular disease such as AIDS, malaria, schistosomiasis and diabetes.

  16. Opioids: The Prescription Drug & Heroin Overdose Epidemic

    Science.gov (United States)

    ... About the Epidemic Help, Resources and Information National Opioids Crisis Search Search National Helpline SAMHSA’s National Helpline ... 1-800-622-4357 Visit Helpline Website THE OPIOID EPIDEMIC IN NUMBERS 80% Nearly 80% of heroin ...

  17. The Cappadocia mesothelioma epidemic: its influence in Turkey and abroad.

    Science.gov (United States)

    Emri, Salih A

    2017-06-01

    The epidemic of mesothelioma in Cappadocia, Turkey, is unprecedented in medical history. In three Cappadocian villages, Karain, Tuzkoy and "old" Sarihidir, about 50% of all deaths (including neonatal deaths and traffic fatalities) have been caused by mesothelioma. No other epidemic in medical history has caused such a high incidence of death. This is even more unusual when considering that (I) epidemics are caused by infectious agents, not cancer, and (II) mesothelioma is a rare cancer. World-wide mesothelioma incidence varies between 1/10 6 in areas with no asbestos industry to about 10-30/10 6 in areas with asbestos industry. This article reviews how the mesothelioma epidemic was discovered in Cappadocia by Dr. Baris (my mentor), how we initially linked the epidemic to erionite exposure, and later (with Dr. Carbone) to the interaction between genetic predisposition and environmental exposure. Our team's work had an important positive impact on the lives of those living in Cappadocia and also in many genetically predisposed families living around the world. I will discuss how the work that started in three remote Cappadocian villages led to the award of a NCI P01 grant to support our studies. Our studies proved that genetics modulates mineral fiber carcinogenesis and led to the discovery that carriers of germline BAP1 mutations have a very high risk of developing mesothelioma and other malignancies. A new, very active field of research developed following our discoveries to elucidate the mechanism by which BAP1 modulates mineral fiber carcinogenesis as well as to identify additional genes that when mutated increase the risk of mesothelioma and other environmentally related cancers. I am the only surviving member of this research team who saw all the phases of this research and I believe it is important to provide an accurate report, which hopefully will inspire others.

  18. Searching for the corner seismic moment in worldwide data

    Energy Technology Data Exchange (ETDEWEB)

    Felgueiras, Miguel; Santos, Rui; Martins, João Paulo [CEAUL Lisbon and ESTG, Polytechnic Institute of Leiria (Portugal)

    2015-12-31

    In this paper the existence of the corner frequency value for the seismic moment distribution is investigated, analysing worldwide data. Pareto based distributions, usually considered as the most suitable to this type of data, are fitted to the most recent data, available in a global earthquake catalog. Despite the undeniable finite nature of the seismic moment data, we conclude that no corner frequency can be established considering the available data set.

  19. Structured Modeling and Analysis of Stochastic Epidemics with Immigration and Demographic Effects.

    Science.gov (United States)

    Baumann, Hendrik; Sandmann, Werner

    2016-01-01

    Stochastic epidemics with open populations of variable population sizes are considered where due to immigration and demographic effects the epidemic does not eventually die out forever. The underlying stochastic processes are ergodic multi-dimensional continuous-time Markov chains that possess unique equilibrium probability distributions. Modeling these epidemics as level-dependent quasi-birth-and-death processes enables efficient computations of the equilibrium distributions by matrix-analytic methods. Numerical examples for specific parameter sets are provided, which demonstrates that this approach is particularly well-suited for studying the impact of varying rates for immigration, births, deaths, infection, recovery from infection, and loss of immunity.

  20. The Characteristics of TB Epidemic and TB/HIV Co-Infection Epidemic: A 2007-2013 Retrospective Study in Urumqi, Xinjiang Province, China.

    Science.gov (United States)

    Wei, Wang; Wei-Sheng, Zhang; Ahan, Alayi; Ci, Yan; Wei-Wen, Zhang; Ming-Qin, Cao

    2016-01-01

    This study was aimed to find out epidemiologic characteristic of tuberculosis (TB) cases, and Human Immunodeficiency Virus (HIV) positive cases among TB patients (TB/HIV co-infection) through demographic, temporal, and spatial study in Urumqi. Descriptive statistics and multivariate logistic regression were applied to identify the epidemiologic characteristics and risk factors of TB epidemic and TB/HIV co-infection epidemic. All addresses of each TB case, TB/HIV co-infection case, and administrative street were transformed into geographical coordinate. Subsequently, the geocoded address for 82 streets was transformed into a dot map used as the basis of spatial datasets. In addition, the paper also used quantile map and the spatial scan statistic in order to identify the spatial distribution and spatial clusters of TB epidemic and TB/HIV co-infection epidemic. There was a declining trend of the notification rates of TB epidemic from 2007 to 2009, as well as a rising trend from 2010 to 2013. However, the notification rates of TB/HIV co-infection epidemic showed a rising trend from 2007 to 2010, and a declining trend from 2011 to 2013. Moreover, a significant share of TB epidemic and TB/HIV co-infection epidemic happened between the age of 15 to 45 years old, indicating an increase in risk of TB and TB/HIV infection. It is worth noting that the risk of HIV infection for male TB patients was 2.947 times (95% CI [2.178, 3.988]) than that of female patients. Han ethnicity and Uygur ethnicity in urban region accounted for a large proportion of total TB and TB/HIV co-infection cases. Most of the TB cases of minorities in Urumqi showed a statistically significant increase in risk of HIV infection than Han ethnicity in Urumqi. In addition, the spatial distribution of TB epidemic and TB/HIV co-infection epidemic was highly skewed. Most of the local clusters were located in urban area and rural-urban continuum where showed an increase in risk of TB and TB/HIV infection. The

  1. The Characteristics of TB Epidemic and TB/HIV Co-Infection Epidemic: A 2007-2013 Retrospective Study in Urumqi, Xinjiang Province, China.

    Directory of Open Access Journals (Sweden)

    Wang Wei

    Full Text Available This study was aimed to find out epidemiologic characteristic of tuberculosis (TB cases, and Human Immunodeficiency Virus (HIV positive cases among TB patients (TB/HIV co-infection through demographic, temporal, and spatial study in Urumqi.Descriptive statistics and multivariate logistic regression were applied to identify the epidemiologic characteristics and risk factors of TB epidemic and TB/HIV co-infection epidemic. All addresses of each TB case, TB/HIV co-infection case, and administrative street were transformed into geographical coordinate. Subsequently, the geocoded address for 82 streets was transformed into a dot map used as the basis of spatial datasets. In addition, the paper also used quantile map and the spatial scan statistic in order to identify the spatial distribution and spatial clusters of TB epidemic and TB/HIV co-infection epidemic.There was a declining trend of the notification rates of TB epidemic from 2007 to 2009, as well as a rising trend from 2010 to 2013. However, the notification rates of TB/HIV co-infection epidemic showed a rising trend from 2007 to 2010, and a declining trend from 2011 to 2013. Moreover, a significant share of TB epidemic and TB/HIV co-infection epidemic happened between the age of 15 to 45 years old, indicating an increase in risk of TB and TB/HIV infection. It is worth noting that the risk of HIV infection for male TB patients was 2.947 times (95% CI [2.178, 3.988] than that of female patients. Han ethnicity and Uygur ethnicity in urban region accounted for a large proportion of total TB and TB/HIV co-infection cases. Most of the TB cases of minorities in Urumqi showed a statistically significant increase in risk of HIV infection than Han ethnicity in Urumqi. In addition, the spatial distribution of TB epidemic and TB/HIV co-infection epidemic was highly skewed. Most of the local clusters were located in urban area and rural-urban continuum where showed an increase in risk of TB and TB

  2. Dengue and dengue hemorrhagic fever epidemics in Brazil: what research is needed based on trends, surveillance, and control experiences?

    Directory of Open Access Journals (Sweden)

    Teixeira Maria da Glória

    2005-01-01

    Full Text Available Dengue epidemics account annually for several million cases and deaths worldwide. The high endemic level of dengue fever and its hemorrhagic form correlates to extensive domiciliary infestation by Aedes aegypti and multiple viral serotype human infection. This study analyzed serial case reports registered in Brazil since 1981, describing incidence evolutionary patterns and spatial distribution. Epidemic waves followed the introduction of every serotype (DEN 1 to 3, and reduction in susceptible individuals possibly accounted for decreasing case frequency. An incremental expansion of affected areas and increasing occurrence of dengue fever and its hemorrhagic form with high case fatality were noted in recent years. In contrast, efforts based solely on chemical vector control have been insufficient. Moreover, some evidence demonstrates that educational measures do not permanently modify population habits. Thus, as long as a vaccine is not available, further dengue control depends on potential results from basic interdisciplinary research and intervention evaluation studies, integrating environmental changes, community participation and education, epidemiological and virological surveillance, and strategic technological innovations aimed to stop transmission.

  3. [Mycoplasma pneumoniae epidemic as zoonosis].

    Science.gov (United States)

    Mikola, I; Balogh, G; Nagy, A; Mátyás, M; Glávits, R; Stipkovits, L

    1997-11-16

    At a secondary school in Budapest, in the first class, 30 students became sick with fever and upper respiratory catarrhal symptoms between September 19 and October 31, 1995. Two children were hospitalized with a diagnosis of pneumonia, in case of the two children treated at the Szent László Hospital, suspect of Mycoplasma infection raised which was also confirmed by cold agglutination test. During the epizootiological examination on the spot they found a terrarium in the classroom where the students raised a Syrian gold hamster family. Mycoplasmas were isolated from the lung samples of the hamsters during the pathological examination which proved to be Mycoplasma pneumoniae. Owing to the close etiologic relationships between epidemiological anamnesis, characteristics of the epidemic, as well as findings of patients and pathological or histological findings in the hamsters together with the results of bacteriological examinations, the epidemic should be considered as a zoonosis.

  4. Multiple routes transmitted epidemics on multiplex networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dawei [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Shandong Provincial Key Laboratory of Computer Network, Shandong Computer Science Center, Jinan 250014 (China); Li, Lixiang [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng, E-mail: penghaipeng@bupt.edu.cn [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Luo, Qun; Yang, Yixian [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2014-02-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  5. Quasi-neutral theory of epidemic outbreaks.

    Directory of Open Access Journals (Sweden)

    Oscar A Pinto

    Full Text Available Some epidemics have been empirically observed to exhibit outbreaks of all possible sizes, i.e., to be scale-free or scale-invariant. Different explanations for this finding have been put forward; among them there is a model for "accidental pathogens" which leads to power-law distributed outbreaks without apparent need of parameter fine tuning. This model has been claimed to be related to self-organized criticality, and its critical properties have been conjectured to be related to directed percolation. Instead, we show that this is a (quasi neutral model, analogous to those used in Population Genetics and Ecology, with the same critical behavior as the voter-model, i.e. the theory of accidental pathogens is a (quasi-neutral theory. This analogy allows us to explain all the system phenomenology, including generic scale invariance and the associated scaling exponents, in a parsimonious and simple way.

  6. Leptospirosis: A Silent Epidemic Disease

    Directory of Open Access Journals (Sweden)

    Maria Cristina Schneider

    2013-12-01

    Full Text Available This special issue of International Journal of Environmental Research and Public Health is dedicated to leptospirosis, an endemic zoonotic disease that is a cause of many acute undifferentiated fevers, especially in tropical countries [1,2]. While it can be debated whether leptospirosis is an emerging disease, it is evident that it is becoming an emerging public health problem. It is recognized as a disease of epidemic potential that has a significant health impact in many parts of the world.

  7. SIS Epidemic Spreading with Heterogeneous Infection Rates

    CERN Document Server

    Qu, Bo

    2015-01-01

    In this work, we aim to understand the influence of the heterogeneity of infection rates on the Susceptible-Infected-Susceptible (SIS) epidemic spreading. Specifically, we keep the recovery rates the same for all nodes and study the influence of the moments of the independently identically distributed (i.i.d.) infection rates on the average fraction $y_\\infty$ of infected nodes in the meta-stable state, which indicates the severity of the overall infection. Motivated by real-world datasets, we consider the log-normal and gamma distributions for the infection rates and we design as well a symmetric distribution so that we have a systematic view of the influence of various distributions. By continuous-time simulations on several types of networks, theoretical proofs and physical interpretations, we conclude that: 1) the heterogeneity of infection rates on average retards the virus spread, and 2) a larger even-order moment of the infection rates leads to a smaller average fraction of infected nodes, but the odd-...

  8. Advances in apple culture worldwide

    Directory of Open Access Journals (Sweden)

    Terence Robinson

    2011-10-01

    Full Text Available Over the last 60 years, planting densities for apple have increased as improved management systems have been developed. Dwarfing rootstocks have been the key to the dramatic changes in tree size, spacing and early production. The Malling series of dwarfing rootstocks (M.9 and M.26 have been the most important dwarfing rootstocks in the world but are poorly adapted in some areas of the world and they are susceptible to the bacterial disease fire blight and the soil disease complex, apple replant disease which limits their uses in some areas. Rootstock breeding programs in several parts of the world are developing improved rootstocks with resistance to fire blight, and replant disease, and improved cold hardiness and yield efficiency. A second important trend has been the increasing importance of new cultivars. New cultivars have provided opportunities for higher prices until they are over-produced. A new trend is the "variety club" in which variety owners manage the production and marketing of a new unique cultivar to bring higher prices to the growers and variety owners. This has led to many fruit growers being unable to plant or grow some new cultivars. Important rootstock and cultivar genes have been mapped and can be used in marker assisted selection of future rootstock and cultivar selections. Other important improvements in apple culture include the development of pre-formed trees, the development of minimal pruning strategies and limb angle bending which have also contributed to the dramatic changes in early production in the 2nd-5th years after planting. Studies on light interception and distribution have led to improved tree forms with better fruit quality. Simple pruning strategies and labor positioning platform machines have resulted in partial mechanization of pruning which has reduced management costs. Improved plant growth regulators for thinning and the development of a thinning prediction model based on tree carbohydrate balance

  9. Optimal Control Strategy for Traffic Driven Epidemic Spreading Based on Community Structure

    Directory of Open Access Journals (Sweden)

    Fei Shao

    2013-01-01

    Full Text Available It is shown that community structure has a great impact on traffic transportation and epidemic spreading. The density of infected nodes and the epidemic threshold have been proven to have significant relationship with the node betweenness in traffic driven epidemic spreading method. In this paper, considering the impact of community structure on traffic driven epidemic spreading, an effective and novel strategy to control epidemic spreading in scale-free networks is proposed. Theoretical analysis shows that the new control strategy will obviously increase the ratio between the first and the second moments of the node betweenness distribution in scale-free networks. It is also found that the more accurate the community is identified, the stronger community structure the network has and the more efficient the control strategy is. Simulations on both computer-generated and real-world networks have confirmed the theoretical results.

  10. Spectral clustering with epidemic diffusion

    Science.gov (United States)

    Smith, Laura M.; Lerman, Kristina; Garcia-Cardona, Cristina; Percus, Allon G.; Ghosh, Rumi

    2013-10-01

    Spectral clustering is widely used to partition graphs into distinct modules or communities. Existing methods for spectral clustering use the eigenvalues and eigenvectors of the graph Laplacian, an operator that is closely associated with random walks on graphs. We propose a spectral partitioning method that exploits the properties of epidemic diffusion. An epidemic is a dynamic process that, unlike the random walk, simultaneously transitions to all the neighbors of a given node. We show that the replicator, an operator describing epidemic diffusion, is equivalent to the symmetric normalized Laplacian of a reweighted graph with edges reweighted by the eigenvector centralities of their incident nodes. Thus, more weight is given to edges connecting more central nodes. We describe a method that partitions the nodes based on the componentwise ratio of the replicator's second eigenvector to the first and compare its performance to traditional spectral clustering techniques on synthetic graphs with known community structure. We demonstrate that the replicator gives preference to dense, clique-like structures, enabling it to more effectively discover communities that may be obscured by dense intercommunity linking.

  11. Understanding the Cholera Epidemic, Haiti

    Science.gov (United States)

    Barrais, Robert; Faucher, Benoît; Haus, Rachel; Piarroux, Martine; Gaudart, Jean; Magloire, Roc; Raoult, Didier

    2011-01-01

    After onset of a cholera epidemic in Haiti in mid-October 2010, a team of researchers from France and Haiti implemented field investigations and built a database of daily cases to facilitate identification of communes most affected. Several models were used to identify spatiotemporal clusters, assess relative risk associated with the epidemic’s spread, and investigate causes of its rapid expansion in Artibonite Department. Spatiotemporal analyses highlighted 5 significant clusters (p<0.001): 1 near Mirebalais (October 16–19) next to a United Nations camp with deficient sanitation, 1 along the Artibonite River (October 20–28), and 3 caused by the centrifugal epidemic spread during November. The regression model indicated that cholera more severely affected communes in the coastal plain (risk ratio 4.91) along the Artibonite River downstream of Mirebalais (risk ratio 4.60). Our findings strongly suggest that contamination of the Artibonite and 1 of its tributaries downstream from a military camp triggered the epidemic. PMID:21762567

  12. CMS centres worldwide: A new collaborative infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Lucas; /Northeastern U.; Gottschalk, Erik; /Fermilab

    2010-01-01

    The CMS Experiment at the LHC is establishing a global network of inter-connected 'CMS Centres' for controls, operations and monitoring. These support: (1) CMS data quality monitoring, detector calibrations, and analysis; and (2) computing operations for the processing, storage and distribution of CMS data. We describe the infrastructure, computing, software, and communications systems required to create an effective and affordable CMS Centre. We present our highly successful operations experiences with the major CMS Centres at CERN, Fermilab, and DESY during the LHC first beam data-taking and cosmic ray commissioning work. The status of the various centres already operating or under construction in Asia, Europe, Russia, South America, and the USA is also described. We emphasise the collaborative communications aspects. For example, virtual co-location of experts in CMS Centres Worldwide is achieved using high-quality permanently-running 'telepresence' video links. Generic Web-based tools have been developed and deployed for monitoring, control, display management and outreach.

  13. Identifying Potential Norovirus Epidemics in China via Internet Surveillance.

    Science.gov (United States)

    Liu, Kui; Huang, Sichao; Miao, Zi-Ping; Chen, Bin; Jiang, Tao; Cai, Gaofeng; Jiang, Zhenggang; Chen, Yongdi; Wang, Zhengting; Gu, Hua; Chai, Chengliang; Jiang, Jianmin

    2017-08-08

    Norovirus is a common virus that causes acute gastroenteritis worldwide, but a monitoring system for norovirus is unavailable in China. We aimed to identify norovirus epidemics through Internet surveillance and construct an appropriate model to predict potential norovirus infections. The norovirus-related data of a selected outbreak in Jiaxing Municipality, Zhejiang Province of China, in 2014 were collected from immediate epidemiological investigation, and the Internet search volume, as indicated by the Baidu Index, was acquired from the Baidu search engine. All correlated search keywords in relation to norovirus were captured, screened, and composited to establish the composite Baidu Index at different time lags by Spearman rank correlation. The optimal model was chosen and possibly predicted maps in Zhejiang Province were presented by ArcGIS software. The combination of two vital keywords at a time lag of 1 day was ultimately identified as optimal (ρ=.924, Pnorovirus infections by 2.15 times during the outbreak. In addition to Jiaxing Municipality, Hangzhou Municipality might have had some potential epidemics in the study time from the predicted model. Although there are limitations with early warning and unavoidable biases, Internet surveillance may be still useful for the monitoring of norovirus epidemics when a monitoring system is unavailable.

  14. Malaria hotspot areas in a highland Kenya site are consistent in epidemic and non-epidemic years and are associated with ecological factors

    Directory of Open Access Journals (Sweden)

    Ernst Kacey C

    2006-09-01

    Full Text Available Abstract Background Malaria epidemics in highland areas of East Africa have caused considerable morbidity and mortality in the past two decades. Knowledge of "hotspot" areas of high malaria incidence would allow for focused preventive interventions in resource-poor areas, particularly if the hotspot areas can be discerned during non-epidemic periods and predicted by ecological factors. Methods To address this issue, spatial distribution of malaria incidence and the relationship of ecological factors to malaria incidence were assessed in the highland area of Kipsamoite, Kenya, from 2001–2004. Results Clustering of disease in a single geographic "hotspot" area occurred in epidemic and non-epidemic years, with a 2.6 to 3.2-fold increased risk of malaria inside the hotspot, as compared to outside the area (P Conclusion In this highland area, areas of high malaria risk are consistent in epidemic and non-epidemic years and are associated with specific ecological risk factors. Ongoing interventions in areas of ecological risk factors could be a cost-effective method of significantly reducing malaria incidence and blunting or preventing epidemics, even in the absence of malaria early warning systems. Further studies should be conducted to see if these findings hold true in varied highland settings.

  15. Worldwide distribution of soil dielectric and thermal properties

    NARCIS (Netherlands)

    Hendrickx, J.M.H.; Dam, R.L. van; Borchers, B.; Curtis, J.; Lensen, H.A.; Harmon, R.

    2003-01-01

    Ground penetrating radar and thermal sensors hold much promise for the detection of non-metallic land mines. In previous work we have shown that the performance of ground penetrating radar strongly depends on field soil conditions such as texture, water content, and soil-water salinity since these

  16. Prevalence and distribution of principal periodontal pathogens worldwide

    DEFF Research Database (Denmark)

    Rylev, Mette; Kilian, Mogens

    2008-01-01

    to particular ethnic groups. AIM: This review analyzes to what extent observed differences in periodontal disease prevalence among ethnically or geographically distinct populations may be explained by restricted host adaptation of clones of principal periodontal pathogens. RESULTS: Carriage rates of several...... putative periodontal pathogens and particular subsets of these species vary between ethnic groups. Few of these differences can, with the limited information available, be directly related to differences in periodontal disease prevalence. Asian populations are regularly colonized with Actinobacillus...... are likely to give better insight into the aetiology of periodontal diseases....

  17. Innovation in Science Education - World-Wide.

    Science.gov (United States)

    Baez, Albert V.

    The purpose of this book is to promote improvements in science education, world-wide, but particularly in developing countries. It is addressed to those in positions to make effective contributions to the improvement of science education. The world-wide role of science education, the goals of innovative activities, past experience in efforts to…

  18. Emergence and global spread of epidemic healthcare-associated Clostridium difficile

    OpenAIRE

    He, Miao; Miyajima, Fabio; Roberts, Paul; Ellison, Louise; Pickard, Derek J.; Martin, Melissa J.; Connor, Thomas R.; Harris, Simon R.; Fairley, Derek; Bamford, Kathleen B.; D?Arc, Stephanie; Brazier, Jon; Brown, Derek; Coia, John E.; Douce, Gill

    2012-01-01

    Epidemic C. difficile (027/BI/NAP1) has rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key events in evolutionary history leading to its emergence and the subsequent patterns of global spread remain unknown. Here, we define the global population structure of C. difficile 027/BI/NAP1 using whole-genome sequencing and phylogenetic analysis. We show that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought...

  19. Spatial Big Data Analytics of Influenza Epidemic in Vellore, India.

    Science.gov (United States)

    Lopez, Daphne; Gunasekaran, M; Murugan, B Senthil; Kaur, Harpreet; Abbas, Kaja M

    2014-10-01

    The study objective is to develop a big spatial data model to predict the epidemiological impact of influenza in Vellore, India. Large repositories of geospatial and health data provide vital statistics on surveillance and epidemiological metrics, and valuable insight into the spatiotemporal determinants of disease and health. The integration of these big data sources and analytics to assess risk factors and geospatial vulnerability can assist to develop effective prevention and control strategies for influenza epidemics and optimize allocation of limited public health resources. We used the spatial epidemiology data of the HIN1 epidemic collected at the National Informatics Center during 2009-2010 in Vellore. We developed an ecological niche model based on geographically weighted regression for predicting influenza epidemics in Vellore, India during 2013-2014. Data on rainfall, temperature, wind speed, humidity and population are included in the geographically weighted regression analysis. We inferred positive correlations for H1N1 influenza prevalence with rainfall and wind speed, and negative correlations for H1N1 influenza prevalence with temperature and humidity. We evaluated the results of the geographically weighted regression model in predicting the spatial distribution of the influenza epidemic during 2013-2014.

  20. The effect of awareness on networked SIS epidemics

    KAUST Repository

    Paarporn, Keith

    2017-01-05

    We study an SIS epidemic model over an arbitrary fixed network topology where the n agents, or nodes of the network, have partial information about the epidemic state. The agents react by distancing themselves from their neighbors when they believe the epidemic is currently prevalent. An agent\\'s awareness is weighted from three sources of information: the fraction of infected neighbors in their contact network, their social network, and a global broadcast of the fraction of infected nodes in the entire network. The dynamics of the benchmark (no awareness) and awareness models are described by discrete-time 2-state Markov chains. Through a coupling technique, we establish monotonicity properties between the benchmark and awareness models. Particularly, we show that the expectation of any increasing random variable on the space of sample paths, e.g. eradication time or total infections, is lower for the awareness model. In addition, we give a characterization for this difference of expectations in terms of the coupling distribution. In simulations, we evaluate how different sources of information affect the spread of an epidemic.

  1. The cancer, a silent epidemic.

    Directory of Open Access Journals (Sweden)

    Edith María Beltrán Molina

    2014-03-01

    Full Text Available This article deals with some very interesting aspects related to cancer the first cause of death in many countries with a high prevalence in Cuba so it is necessary to increase prevention and education to reduce risk factors and prevalence of malignancy. Taking into account the importance of cancer awareness as well as the social therapeutic and technological resources available to Cuba for its treatment it is propose with this work to exemplify the Cuban scientific treatment of cancer as a silent epidemic of the XXI century.

  2. Contact allergy epidemics and their controls

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Johansen, Jeanne Duus; Menné, Torkil

    2007-01-01

    Contact dermatitis can be severe and lead to sick leave as well as significant healthcare expenses. The aim of this review is to present the published knowledge on 6 historical epidemics of contact allergy to apply this knowledge on the prevention and control of future contact allergy epidemics. ...... to prevent contact allergy epidemics. It is essential that dermatologist, scientists, administrators, and consumers organize and structure known methods to accelerate the control of emerging contact allergens....

  3. Worldwide trend of atmospheric mercury since 1995

    Directory of Open Access Journals (Sweden)

    F. Slemr

    2011-05-01

    Full Text Available Concern about the adverse effects of mercury on human health and ecosystems has led to tightening emission controls since the mid 1980s. But the resulting mercury emissions reductions in many parts of the world are believed to be offset or even surpassed by the increasing emissions in rapidly industrializing countries. Consequently, concentrations of atmospheric mercury are expected to remain roughly constant. Here we show that the worldwide atmospheric mercury concentrations have decreased by about 20 to 38 % since 1996 as indicated by long-term monitoring at stations in the Southern and Northern Hemispheres combined with intermittent measurements of latitudinal distribution over the Atlantic Ocean. The total reduction of the atmospheric mercury burden of this magnitude within 14 years is unusually large among most atmospheric trace gases and is at odds with the current mercury emission inventories with nearly constant anthropogenic emissions over this period. This suggests a major shift in the biogeochemical cycle of mercury including oceans and soil reservoirs. Decreasing reemissions from the legacy of historical mercury emissions are the most likely explanation for this decline since the hypothesis of an accelerated oxidation rate of elemental mercury in the atmosphere is not supported by the observed trends of other trace gases. Acidification of oceans, climate change, excess nutrient input and pollution may also contribute by their impact on the biogeochemistry of ocean and soils. Consequently, models of the atmospheric mercury cycle have to include soil and ocean mercury pools and their dynamics to be able to make projections of future trends.

  4. Middle East respiratory syndrome coronavirus: quantification of the extent of the epidemic, surveillance biases, and transmissibility.

    Science.gov (United States)

    Cauchemez, Simon; Fraser, Christophe; Van Kerkhove, Maria D; Donnelly, Christl A; Riley, Steven; Rambaut, Andrew; Enouf, Vincent; van der Werf, Sylvie; Ferguson, Neil M

    2014-01-01

    The novel Middle East respiratory syndrome coronavirus (MERS-CoV) had, as of Aug 8, 2013, caused 111 virologically confirmed or probable human cases of infection worldwide. We analysed epidemiological and genetic data to assess the extent of human infection, the performance of case detection, and the transmission potential of MERS-CoV with and without control measures. We assembled a comprehensive database of all confirmed and probable cases from public sources and estimated the incubation period and generation time from case cluster data. Using data of numbers of visitors to the Middle East and their duration of stay, we estimated the number of symptomatic cases in the Middle East. We did independent analyses, looking at the growth in incident clusters, the growth in viral population, the reproduction number of cluster index cases, and cluster sizes to characterise the dynamical properties of the epidemic and the transmission scenario. The estimated number of symptomatic cases up to Aug 8, 2013, is 940 (95% CI 290-2200), indicating that at least 62% of human symptomatic cases have not been detected. We find that the case-fatality ratio of primary cases detected via routine surveillance (74%; 95% CI 49-91) is biased upwards because of detection bias; the case-fatality ratio of secondary cases was 20% (7-42). Detection of milder cases (or clinical management) seemed to have improved in recent months. Analysis of human clusters indicated that chains of transmission were not self-sustaining when infection control was implemented, but that R in the absence of controls was in the range 0·8-1·3. Three independent data sources provide evidence that R cannot be much above 1, with an upper bound of 1·2-1·5. By showing that a slowly growing epidemic is underway either in human beings or in an animal reservoir, quantification of uncertainty in transmissibility estimates, and provision of the first estimates of the scale of the epidemic and extent of case detection biases

  5. Epidemic Survivability: Characterizing Networks Under Epidemic-like Failure Propagation Scenarios

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2013-01-01

    in telecommunication networks has not been extensively considered, nowadays, with the increasing computation capacity and complexity of operating systems of modern network devices (routers, switches, etc.), the study of possible epidemic-like failure scenarios must be taken into account. When epidemics occur......, such as in other multiple failure scenarios, identifying the level of vulnerability offered by a network is one of the main challenges. In this paper, we present epidemic survivability, a new network measure that describes the vulnerability of each node of a network under a specific epidemic intensity. Moreover......, this metric is able to identify the set of nodes which are more vulnerable under an epidemic attack. In addition, two applications of epidemic survivability are provided. First, we introduce epidemic criticality, a novel robustness metric for epidemic failure scenarios. A case study shows the utility...

  6. Heart Disease the No. 1 Killer Worldwide

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_165667.html Heart Disease the No. 1 Killer Worldwide Low-cost, effective ... deaths around the world are the result of heart disease and stroke, making cardiovascular disease the number one ...

  7. Climate-based models for understanding and forecasting dengue epidemics.

    Directory of Open Access Journals (Sweden)

    Elodie Descloux

    Full Text Available BACKGROUND: Dengue dynamics are driven by complex interactions between human-hosts, mosquito-vectors and viruses that are influenced by environmental and climatic factors. The objectives of this study were to analyze and model the relationships between climate, Aedes aegypti vectors and dengue outbreaks in Noumea (New Caledonia, and to provide an early warning system. METHODOLOGY/PRINCIPAL FINDINGS: Epidemiological and meteorological data were analyzed from 1971 to 2010 in Noumea. Entomological surveillance indices were available from March 2000 to December 2009. During epidemic years, the distribution of dengue cases was highly seasonal. The epidemic peak (March-April lagged the warmest temperature by 1-2 months and was in phase with maximum precipitations, relative humidity and entomological indices. Significant inter-annual correlations were observed between the risk of outbreak and summertime temperature, precipitations or relative humidity but not ENSO. Climate-based multivariate non-linear models were developed to estimate the yearly risk of dengue outbreak in Noumea. The best explicative meteorological variables were the number of days with maximal temperature exceeding 32°C during January-February-March and the number of days with maximal relative humidity exceeding 95% during January. The best predictive variables were the maximal temperature in December and maximal relative humidity during October-November-December of the previous year. For a probability of dengue outbreak above 65% in leave-one-out cross validation, the explicative model predicted 94% of the epidemic years and 79% of the non epidemic years, and the predictive model 79% and 65%, respectively. CONCLUSIONS/SIGNIFICANCE: The epidemic dynamics of dengue in Noumea were essentially driven by climate during the last forty years. Specific conditions based on maximal temperature and relative humidity thresholds were determinant in outbreaks occurrence. Their persistence was

  8. Yellow fever in the Americas: the growing concern about new epidemics [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Yeimer Ortiz-Martínez

    2017-04-01

    Full Text Available Yellow fever (YF is a haemorrhagic viral disease with a high case fatality rate. It is considered a reemerging infectious disease of remarkable importance. During the last outbreaks in Brazil (2016-2017, many cases of YF emerged despite high YF vaccination coverage in some areas. However, there are many areas and populations worldwide where vaccination coverage has been low for years (e.g. Nigeria, which increases the risk of major epidemics in such areas, as would be the case in many of the American territories. Several factors, including the vast border and migratory status of Brazil, the widespread distribution of Aedes mosquitoes and the lack of efficient health policies and surveillance systems, favor this complex epidemiological scenario of reemergence. Therefore, mass vaccination of the population at risk, public health awareness and preparedness are urgently needed in this region. This opinion article describes the current global epidemiological situation of YF, focusing especially on the Americas, as well the risk and vulnerabilities in the region that would be of concern for major expansion to other countries apart from Brazil. Also, imported risk from endemic area outside of Americas (i.e. Africa are of current concern.

  9. Real time bayesian estimation of the epidemic potential of emerging infectious diseases.

    Directory of Open Access Journals (Sweden)

    Luís M A Bettencourt

    Full Text Available BACKGROUND: Fast changes in human demographics worldwide, coupled with increased mobility, and modified land uses make the threat of emerging infectious diseases increasingly important. Currently there is worldwide alert for H5N1 avian influenza becoming as transmissible in humans as seasonal influenza, and potentially causing a pandemic of unprecedented proportions. Here we show how epidemiological surveillance data for emerging infectious diseases can be interpreted in real time to assess changes in transmissibility with quantified uncertainty, and to perform running time predictions of new cases and guide logistics allocations. METHODOLOGY/PRINCIPAL FINDINGS: We develop an extension of standard epidemiological models, appropriate for emerging infectious diseases, that describes the probabilistic progression of case numbers due to the concurrent effects of (incipient human transmission and multiple introductions from a reservoir. The model is cast in terms of surveillance observables and immediately suggests a simple graphical estimation procedure for the effective reproductive number R (mean number of cases generated by an infectious individual of standard epidemics. For emerging infectious diseases, which typically show large relative case number fluctuations over time, we develop a bayesian scheme for real time estimation of the probability distribution of the effective reproduction number and show how to use such inferences to formulate significance tests on future epidemiological observations. CONCLUSIONS/SIGNIFICANCE: Violations of these significance tests define statistical anomalies that may signal changes in the epidemiology of emerging diseases and should trigger further field investigation. We apply the methodology to case data from World Health Organization reports to place bounds on the current transmissibility of H5N1 influenza in humans and establish a statistical basis for monitoring its evolution in real time.

  10. A large temperature fluctuation may trigger an epidemic erythromelalgia outbreak in China

    Science.gov (United States)

    Liu, Tao; Zhang, Yonghui; Lin, Hualiang; Lv, Xiaojuan; Xiao, Jianpeng; Zeng, Weilin; Gu, Yuzhou; Rutherford, Shannon; Tong, Shilu; Ma, Wenjun

    2015-03-01

    Although erythromelalgia (EM) has been documented in the literature for almost 150 years, it is still poorly understood. To overcome this limitation, we examined the spatial distribution of epidemic EM, and explored the association between temperature fluctuation and epidemic EM outbreaks in China. We searched all peer-reviewed literature on primary epidemic EM outbreaks in China. A two-stage model was used to characterize the relationship between temperature fluctuation and epidemic EM outbreaks. We observed that epidemic EM outbreaks were reported from 13 provinces during 1960-2014 and they mainly occurred between February and March in southern China. The majority of EM cases were middle school students, with a higher incidence rate in female and resident students. The major clinical characteristics of EM cases included burning, sharp, tingling and/or stinging pain in toes, soles and/or dorsum of feet, fever, erythema and swelling. A large ``V''-shaped fluctuation of daily average temperature (TM) observed during the epidemic EM outbreaks was significantly associated with the number of daily EM cases (β = 1.22, 95%CI: 0.66 ~ 1.79), which indicated that this ``V''-shaped fluctuation of TM probably triggered the epidemic EM outbreaks.

  11. The epidemic of Athens, 430 - 426 BC

    African Journals Online (AJOL)

    1998-01-01

    Jan 1, 1998 ... mus, the generally accepted word for 'mouse')." The epidemic of Constantinople in 542 AD probably represents the first recorded plague epidemic - a disease which later created havoc as the 'Black Death' in medieval Europe".22. Plague classically manifests itself in either bubonic or septicaemic forms, but ...

  12. Reemerging threat of epidemic typhus in Algeria.

    Science.gov (United States)

    Mokrani, K; Fournier, P E; Dalichaouche, M; Tebbal, S; Aouati, A; Raoult, D

    2004-08-01

    We report a case of epidemic typhus in a patient from the Batna region of Algeria, who presented with generalized febrile exanthema. The clinical diagnosis was confirmed by serological cross-adsorption followed by Western blotting. Our report emphasizes the threat of epidemic typhus in the highlands of Algeria.

  13. A break in the obesity epidemic?

    DEFF Research Database (Denmark)

    Visscher, T L S; Heitmann, B L; Rissanen, A

    2015-01-01

    epidemic. However, follow-ups of short duration may, in part, explain the apparent break or decrease in the obesity epidemic. On the other hand, a single focus on body mass index (BMI) ⩾25 or ⩾30 kg m(-)(2) is likely to mask a real increase in the obesity epidemic. And, in both children and adults, trends......Recent epidemiologic papers are presenting prevalence data suggesting breaks and decreases in obesity rates. However, before concluding that the obesity epidemic is not increasing anymore, the validity of the presented data should be discussed more thoroughly. We had a closer look...... into the literature presented in recent reviews to address the major potential biases and distortions, and to develop insights about how to interpret the presented suggestions for a potential break in the obesity epidemic. Decreasing participation rates, the use of reported rather than measured data and small sample...

  14. Inferring epidemic contact structure from phylogenetic trees.

    Directory of Open Access Journals (Sweden)

    Gabriel E Leventhal

    Full Text Available Contact structure is believed to have a large impact on epidemic spreading and consequently using networks to model such contact structure continues to gain interest in epidemiology. However, detailed knowledge of the exact contact structure underlying real epidemics is limited. Here we address the question whether the structure of the contact network leaves a detectable genetic fingerprint in the pathogen population. To this end we compare phylogenies generated by disease outbreaks in simulated populations with different types of contact networks. We find that the shape of these phylogenies strongly depends on contact structure. In particular, measures of tree imbalance allow us to quantify to what extent the contact structure underlying an epidemic deviates from a null model contact network and illustrate this in the case of random mixing. Using a phylogeny from the Swiss HIV epidemic, we show that this epidemic has a significantly more unbalanced tree than would be expected from random mixing.

  15. Epidemic waves of cholera in the last two decades in Mozambique.

    Science.gov (United States)

    Langa, José Paulo; Sema, Cynthia; De Deus, Nilsa; Colombo, Mauro Maria; Taviani, Elisa

    2015-07-04

    Africa is increasingly affected by cholera. In Mozambique, cholera appeared in the early 1970s when the seventh pandemic entered Africa from the Indian subcontinent. In the following decades, several epidemics were registered in the country, the 1997-1999 epidemic being the most extended. Since then, Mozambique has been considered an endemic area for cholera, characterized by yearly outbreaks occurring with a seasonal pattern. At least three pandemic variants are thought to have originated in the Indian subcontinent and spread worldwide at different times. To understand the epidemiology of cholera in Mozambique, whether the disease re-emerges periodically or is imported by different routes of transmission, we investigated clinical V. cholerae O1 isolated during 1997-1999 and 2012-2014 epidemics. By detecting and characterizing seven genetic elements, the mobilome profile of each isolate was obtained. By comparing it to known seventh pandemic reference strains, it was possible to discern among different V. cholerae O1 variants active in the country. During 1997-1999, epidemic strains showed two different genetic profiles, both related to a pandemic clone that originated from India and was reported in other African countries in the 1990s. Isolates from 2012-2014 outbreaks showed a genetic background related to the pandemic strains currently active as the prevalent causative agent of cholera worldwide. Despite cholera being endemic in Mozambique, the epidemiology of the disease in the past 20 years has been strongly influenced by the cholera seventh pandemic waves that originated in the Indian subcontinent.

  16. La epidemia por violencia del compañero íntimo contra las mujeres en España: evolución temporal y edad de las víctimas Epidemic of intimate partner violence against women in Spain: temporal distribution and victim age

    Directory of Open Access Journals (Sweden)

    Carlos Álvarez-Dardet

    2007-08-01

    Full Text Available Objetivo: Explorar la distribución temporal y por edad de las muertes y denuncias de mujeres por violencia del compañero íntimo (VCI para ilustrar una aproximación a los resultados de las medidas desarrolladas en España en torno a este problema. Métodos: Estudio epidemiológico descriptivo basado en los datos de la Federación de Mujeres Separadas y Divorciadas, Centro Reina Sofía para el estudio de la Violencia y Anuarios Estadísticos del Ministerio del Interior (1998-2005. Cálculo de tasas de mortalidad y denuncias de VCI por edad ( 50 años y año. Razón entre casos (denuncias y muertes dados en un mes determinado y mediana de los producidos en el mismo mes en los 5 años anteriores (índice epidémico. Resultados: Desde finales de 2004 se observa una tendencia decreciente en las puntuaciones del índice epidémico de mortalidad y denuncias por VCI. Las mujeres de 21-50 años de edad son las que mayores tasas y puntuaciones del índice epidémico de mortalidad y denuncias presentan en el período de estudio, excepto en 2004, en que las tasas de mortalidad en mujeres menores de 21 años fueron las más elevadas, y en 2005, en que se incrementan las tasas de denuncias en las mujeres mayores de 50 años. Conclusiones: En 2005, la epidemia por VCI parece remitir. El hecho de que se trata de un problema que afecta fundamentalmente a mujeres en edades fértiles y laboralmente activas muestra el carácter instrumental de la VCI para retroalimentar una situación de subordinación femenina.Objective: To explore temporal distribution and victim age in deaths and women's reports of intimate partner violence (IPV to illustrate an approach to the results of the measures developed in Spain to combat this problem. Methods: We performed a descriptive epidemiological study based on statistics from the Federation of Divorced and Separated Women, the Queen Sofía Centre for the study of Violence, and the Home Affairs databases (1998-2005. Rates of

  17. Increasing genetic variance of body mass index during the Swedish obesity epidemic

    DEFF Research Database (Denmark)

    Rokholm, Benjamin; Silventoinen, Karri; Tynelius, Per

    2011-01-01

    There is no doubt that the dramatic worldwide increase in obesity prevalence is due to changes in environmental factors. However, twin and family studies suggest that genetic differences are responsible for the major part of the variation in adiposity within populations. Recent studies show...... that the genetic effects on body mass index (BMI) may be stronger when combined with presumed risk factors for obesity. We tested the hypothesis that the genetic variance of BMI has increased during the obesity epidemic....

  18. The Emerging Chronic Obstructive Pulmonary Disease Epidemic: Clinical Impact, Economic Burden, and Opportunities for Disease Management

    OpenAIRE

    Rick Carter; Brian L. Tiep; Rebecca E. Tiep

    2008-01-01

    The incidence and economic impact of chronic obstructive pulmonary disease (COPD) is escalating worldwide and is projected to remain on a positive trajectory for many years to come. At some point in this escalation, COPD may be regarded as a true epidemic. Unfortunately, the incidence among women is escalating more rapidly than in men, reflecting the social anthropology of changing smoking habits. This knowledge, coupled with the fact that the true disease prevalence is under-reported, sugges...

  19. Endemic and epidemic Acinetobacter baumannii clones: a twelve-year study in a tertiary care hospital

    OpenAIRE

    Villal?n, Pilar; Valdezate, Sylvia; Cabezas, Teresa; Ortega, Montserrat; Garrido, Noelia; Vindel, Ana; Medina-Pascual, Mar?a J; Saez-Nieto, Juan A.

    2015-01-01

    Background Nosocomial outbreaks of multidrug-resistant Acinetobacter baumannii are of worldwide concern. Using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and multiple locus variable number tandem repeat sequence (VNTR) analysis (MLVA), the present work examines the genetic diversity of the endemic and epidemic A. baumannii clones isolated in a single hospital over a twelve-year period. Results PFGE analysis of 405 A. baumannii-calcoaceticus complex isolates de...

  20. NPP Tropical Forest: Consistent Worldwide Site Estimates, 1967-1999, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains documented field measurements of NPP components for 39 old-growth tropical forests distributed worldwide between latitudes 23.58 N and 23.58...

  1. Multiple phase transitions of the susceptible-infected-susceptible epidemic model on complex networks

    CERN Document Server

    Mata, Angélica S

    2014-01-01

    We show that the susceptible-infected-susceptible (SIS) epidemic dynamics running on the top of networks with a power law degree distribution can exhibit multiple phase transitions. Three main transitions involving different mechanisms responsible by sustaining the epidemics are identified: A short-term epidemics concentrated around the most connected vertex; a long-term (asymptotically stable) localized epidemics with a vanishing threshold; and an endemic phase occurring at a finite threshold. The different transitions are suited through different mean-field approaches. We finally show that the multiple transitions are due to the activations of different domains of the network that are observed in rapid (singular) variations of both stationary density of infected vertices and the participation ratio against the infection rate.

  2. The Narcissism Epidemic Is Dead; Long Live the Narcissism Epidemic.

    Science.gov (United States)

    Wetzel, Eunike; Brown, Anna; Hill, Patrick L; Chung, Joanne M; Robins, Richard W; Roberts, Brent W

    2017-12-01

    Are recent cohorts of college students more narcissistic than their predecessors? To address debates about the so-called "narcissism epidemic," we used data from three cohorts of students (1990s: N = 1,166; 2000s: N = 33,647; 2010s: N = 25,412) to test whether narcissism levels (overall and specific facets) have increased across generations. We also tested whether our measure, the Narcissistic Personality Inventory (NPI), showed measurement equivalence across the three cohorts, a critical analysis that had been overlooked in prior research. We found that several NPI items were not equivalent across cohorts. Models accounting for nonequivalence of these items indicated a small decline in overall narcissism levels from the 1990s to the 2010s ( d = -0.27). At the facet level, leadership ( d = -0.20), vanity ( d = -0.16), and entitlement ( d = -0.28) all showed decreases. Our results contradict the claim that recent cohorts of college students are more narcissistic than earlier generations of college students.

  3. Leveraging social networks for understanding the evolution of epidemics.

    Science.gov (United States)

    Martín, Gonzalo; Marinescu, Maria-Cristina; Singh, David E; Carretero, Jesús

    2011-01-01

    To understand how infectious agents disseminate throughout a population it is essential to capture the social model in a realistic manner. This paper presents a novel approach to modeling the propagation of the influenza virus throughout a realistic interconnection network based on actual individual interactions which we extract from online social networks. The advantage is that these networks can be extracted from existing sources which faithfully record interactions between people in their natural environment. We additionally allow modeling the characteristics of each individual as well as customizing his daily interaction patterns by making them time-dependent. Our purpose is to understand how the infection spreads depending on the structure of the contact network and the individuals who introduce the infection in the population. This would help public health authorities to respond more efficiently to epidemics. We implement a scalable, fully distributed simulator and validate the epidemic model by comparing the simulation results against the data in the 2004-2005 New York State Department of Health Report (NYSDOH), with similar temporal distribution results for the number of infected individuals. We analyze the impact of different types of connection models on the virus propagation. Lastly, we analyze and compare the effects of adopting several different vaccination policies, some of them based on individual characteristics -such as age- while others targeting the super-connectors in the social model. This paper presents an approach to modeling the propagation of the influenza virus via a realistic social model based on actual individual interactions extracted from online social networks. We implemented a scalable, fully distributed simulator and we analyzed both the dissemination of the infection and the effect of different vaccination policies on the progress of the epidemics. The epidemic values predicted by our simulator match real data from NYSDOH. Our

  4. Leveraging social networks for understanding the evolution of epidemics

    Directory of Open Access Journals (Sweden)

    Martín Gonzalo

    2011-12-01

    Full Text Available Abstract Background To understand how infectious agents disseminate throughout a population it is essential to capture the social model in a realistic manner. This paper presents a novel approach to modeling the propagation of the influenza virus throughout a realistic interconnection network based on actual individual interactions which we extract from online social networks. The advantage is that these networks can be extracted from existing sources which faithfully record interactions between people in their natural environment. We additionally allow modeling the characteristics of each individual as well as customizing his daily interaction patterns by making them time-dependent. Our purpose is to understand how the infection spreads depending on the structure of the contact network and the individuals who introduce the infection in the population. This would help public health authorities to respond more efficiently to epidemics. Results We implement a scalable, fully distributed simulator and validate the epidemic model by comparing the simulation results against the data in the 2004-2005 New York State Department of Health Report (NYSDOH, with similar temporal distribution results for the number of infected individuals. We analyze the impact of different types of connection models on the virus propagation. Lastly, we analyze and compare the effects of adopting several different vaccination policies, some of them based on individual characteristics -such as age- while others targeting the super-connectors in the social model. Conclusions This paper presents an approach to modeling the propagation of the influenza virus via a realistic social model based on actual individual interactions extracted from online social networks. We implemented a scalable, fully distributed simulator and we analyzed both the dissemination of the infection and the effect of different vaccination policies on the progress of the epidemics. The epidemic values

  5. Youth Purpose Worldwide: A Tapestry of Possibilities

    Science.gov (United States)

    Moran, Seana

    2017-01-01

    Interest in youth purpose is growing among scholars around the world. With globalization, better understanding of life purposes in different countries becomes more important as this generation's youth are influenced by ideas and events anywhere. This special issue contributes to this inclusive, worldwide frame of mind by showcasing work done…

  6. Basic definitions for discrete modeling of computer worms epidemics

    Directory of Open Access Journals (Sweden)

    Pedro Guevara López

    2015-01-01

    Full Text Available The information technologies have evolved in such a way that communication between computers or hosts has become common, so much that the worldwide organization (governments and corporations depends on it; what could happen if these computers stop working for a long time is catastrophic. Unfortunately, networks are attacked by malware such as viruses and worms that could collapse the system. This has served as motivation for the formal study of computer worms and epidemics to develop strategies for prevention and protection; this is why in this paper, before analyzing epidemiological models, a set of formal definitions based on set theory and functions is proposed for describing 21 concepts used in the study of worms. These definitions provide a basis for future qualitative research on the behavior of computer worms, and quantitative for the study of their epidemiological models.

  7. Modeling the impact of twitter on influenza epidemics.

    Science.gov (United States)

    Pawelek, Kasia A; Oeldorf-Hirsch, Anne; Rong, Libin

    2014-12-01

    Influenza remains a serious public-health problem worldwide. The rising popularity and scale of social networking sites such as Twitter may play an important role in detecting, affecting, and predicting influenza epidemics. In this paper, we develop a simple mathematical model including the dynamics of ``tweets'' --- short, 140-character Twitter messages that may enhance the awareness of disease, change individual's behavior, and reduce the transmission of disease among a population during an influenza season. We analyze the model by deriving the basic reproductive number and proving the stability of the steady states. A Hopf bifurcation occurs when a threshold curve is crossed, which suggests the possibility of multiple outbreaks of influenza. We also perform numerical simulations, conduct sensitivity test on a few parameters related to tweets, and compare modeling predictions with surveillance data of influenza-like illness reported cases and the percentage of tweets self-reporting flu during the 2009 H1N1 flu outbreak in England and Wales. These results show that social media programs like Twitter may serve as a good indicator of seasonal influenza epidemics and influence the emergence and spread of the disease.

  8. Higher-order structure and epidemic dynamics in clustered networks.

    Science.gov (United States)

    Ritchie, Martin; Berthouze, Luc; House, Thomas; Kiss, Istvan Z

    2014-05-07

    Clustering is typically measured by the ratio of triangles to all triples regardless of whether open or closed. Generating clustered networks, and how clustering affects dynamics on networks, is reasonably well understood for certain classes of networks (Volz et al., 2011; Karrer and Newman, 2010), e.g. networks composed of lines and non-overlapping triangles. In this paper we show that it is possible to generate networks which, despite having the same degree distribution and equal clustering, exhibit different higher-order structure, specifically, overlapping triangles and other order-four (a closed network motif composed of four nodes) structures. To distinguish and quantify these additional structural features, we develop a new network metric capable of measuring order-four structure which, when used alongside traditional network metrics, allows us to more accurately describe a network׳s topology. Three network generation algorithms are considered: a modified configuration model and two rewiring algorithms. By generating homogeneous networks with equal clustering we study and quantify their structural differences, and using SIS (Susceptible-Infected-Susceptible) and SIR (Susceptible-Infected-Recovered) dynamics we investigate computationally how differences in higher-order structure impact on epidemic threshold, final epidemic or prevalence levels and time evolution of epidemics. Our results suggest that characterising and measuring higher-order network structure is needed to advance our understanding of the impact of network topology on dynamics unfolding on the networks. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Inference of causality in epidemics on temporal contact networks

    Science.gov (United States)

    Braunstein, Alfredo; Ingrosso, Alessandro

    2016-06-01

    Investigating into the past history of an epidemic outbreak is a paramount problem in epidemiology. Based on observations about the state of individuals, on the knowledge of the network of contacts and on a mathematical model for the epidemic process, the problem consists in describing some features of the posterior distribution of unobserved past events, such as the source, potential transmissions, and undetected positive cases. Several methods have been proposed for the study of these inference problems on discrete-time, synchronous epidemic models on networks, including naive Bayes, centrality measures, accelerated Monte-Carlo approaches and Belief Propagation. However, most traced real networks consist of short-time contacts on continuous time. A possibility that has been adopted is to discretize time line into identical intervals, a method that becomes more and more precise as the length of the intervals vanishes. Unfortunately, the computational time of the inference methods increase with the number of intervals, turning a sufficiently precise inference procedure often impractical. We show here an extension of the Belief Propagation method that is able to deal with a model of continuous-time events, without resorting to time discretization. We also investigate the effect of time discretization on the quality of the inference.

  10. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes.

    Science.gov (United States)

    Yang, Hui; Tang, Ming; Gross, Thilo

    2015-08-21

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that network heterogeneity, i.e. a broad degree distribution, can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. However, it has been pointed out that networks in which the properties of nodes are intrinsically heterogeneous can be very resilient to disease spreading. Heterogeneity in structure can enhance or diminish the resilience of networks with heterogeneous nodes, depending on the correlations between the topological and intrinsic properties. Here, we consider a plausible scenario where people have intrinsic differences in susceptibility and adapt their social network structure to the presence of the disease. We show that the resilience of networks with heterogeneous connectivity can surpass those of networks with homogeneous connectivity. For epidemiology, this implies that network heterogeneity should not be studied in isolation, it is instead the heterogeneity of infection risk that determines the likelihood of outbreaks.

  11. Dynamics of Ebola epidemics in West Africa 2014 [v2; ref status: indexed, http://f1000r.es/5fh

    Directory of Open Access Journals (Sweden)

    Robin J. Evans

    2015-05-01

    Full Text Available This paper investigates the dynamics of Ebola virus transmission in West Africa during 2014. The reproduction numbers for the total period of epidemic and for different consequent time intervals are estimated based on a simple linear model. It contains one major parameter - the average infectious period that defines the dynamics of epidemics. Numerical implementations are carried out on data collected from three countries Guinea, Sierra Leone and Liberia as well as the total data collected worldwide. Predictions are provided by considering different scenarios involving the average times of infectiousness for the next few months and the end of the current epidemic is estimated according to each scenario.

  12. Sensitivity analysis of an individual-based model for simulation of influenza epidemics.

    Directory of Open Access Journals (Sweden)

    Elaine O Nsoesie

    Full Text Available Individual-based epidemiology models are increasingly used in the study of influenza epidemics. Several studies on influenza dynamics and evaluation of intervention measures have used the same incubation and infectious period distribution parameters based on the natural history of influenza. A sensitivity analysis evaluating the influence of slight changes to these parameters (in addition to the transmissibility would be useful for future studies and real-time modeling during an influenza pandemic.In this study, we examined individual and joint effects of parameters and ranked parameters based on their influence on the dynamics of simulated epidemics. We also compared the sensitivity of the model across synthetic social networks for Montgomery County in Virginia and New York City (and surrounding metropolitan regions with demographic and rural-urban differences. In addition, we studied the effects of changing the mean infectious period on age-specific epidemics. The research was performed from a public health standpoint using three relevant measures: time to peak, peak infected proportion and total attack rate. We also used statistical methods in the design and analysis of the experiments. The results showed that: (i minute changes in the transmissibility and mean infectious period significantly influenced the attack rate; (ii the mean of the incubation period distribution appeared to be sufficient for determining its effects on the dynamics of epidemics; (iii the infectious period distribution had the strongest influence on the structure of the epidemic curves; (iv the sensitivity of the individual-based model was consistent across social networks investigated in this study and (v age-specific epidemics were sensitive to changes in the mean infectious period irrespective of the susceptibility of the other age groups. These findings suggest that small changes in some of the disease model parameters can significantly influence the uncertainty

  13. Spatiotemporal Dynamics of Dengue Epidemics, Southern Vietnam

    Science.gov (United States)

    Cuong, Hoang Quoc; Vu, Nguyen Thanh; Cazelles, Bernard; Boni, Maciej F.; Thai, Khoa T.D.; Rabaa, Maia A.; Quang, Luong Chan; Simmons, Cameron P.; Huu, Tran Ngoc

    2013-01-01

    An improved understanding of heterogeneities in dengue virus transmission might provide insights into biological and ecologic drivers and facilitate predictions of the magnitude, timing, and location of future dengue epidemics. To investigate dengue dynamics in urban Ho Chi Minh City and neighboring rural provinces in Vietnam, we analyzed a 10-year monthly time series of dengue surveillance data from southern Vietnam. The per capita incidence of dengue was lower in Ho Chi Minh City than in most rural provinces; annual epidemics occurred 1–3 months later in Ho Chi Minh City than elsewhere. The timing and the magnitude of annual epidemics were significantly more correlated in nearby districts than in remote districts, suggesting that local biological and ecologic drivers operate at a scale of 50–100 km. Dengue incidence during the dry season accounted for 63% of variability in epidemic magnitude. These findings can aid the targeting of vector-control interventions and the planning for dengue vaccine implementation. PMID:23735713

  14. The system of the epidemic process.

    Science.gov (United States)

    Cherkasskii, B L

    1988-01-01

    An original social-ecological concept of the epidemic process has been constructed on the basis of using social ecology, systemic approach and the basic principles of cybernetics. According to this concept, the epidemic process is regarded as a biosocial, hierarchic, integral system providing for the reproduction of the species of human parasites. At a higher level of organization, the epidemic process is an epidemiological social-ecological system consisting of two interacting subsystems: the biological (epidemiological ecosystem) and the social (social and economic conditions of life of the society) subsystems where the biological subsystem plays the role of the governed object and the social acts as the internal regulator of these interactions. On the basis of this concept a rational structure of the system of epidemiological surveillance over infectious diseases has been proposed according to which each level of the structure of the epidemic process should be subject to adequate monitoring.

  15. Modeling Epidemics Spreading on Social Contact Networks.

    Science.gov (United States)

    Zhang, Zhaoyang; Wang, Honggang; Wang, Chonggang; Fang, Hua

    2015-09-01

    Social contact networks and the way people interact with each other are the key factors that impact on epidemics spreading. However, it is challenging to model the behavior of epidemics based on social contact networks due to their high dynamics. Traditional models such as susceptible-infected-recovered (SIR) model ignore the crowding or protection effect and thus has some unrealistic assumption. In this paper, we consider the crowding or protection effect and develop a novel model called improved SIR model. Then, we use both deterministic and stochastic models to characterize the dynamics of epidemics on social contact networks. The results from both simulations and real data set conclude that the epidemics are more likely to outbreak on social contact networks with higher average degree. We also present some potential immunization strategies, such as random set immunization, dominating set immunization, and high degree set immunization to further prove the conclusion.

  16. Detecting nonlinearity and chaos in epidemic data

    Energy Technology Data Exchange (ETDEWEB)

    Ellner, S.; Gallant, A.R. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Statistics; Theiler, J. [Santa Fe Inst., NM (United States)]|[Los Alamos National Lab., NM (United States)

    1993-08-01

    Historical data on recurrent epidemics have been central to the debate about the prevalence of chaos in biological population dynamics. Schaffer and Kot who first recognized that the abundance and accuracy of disease incidence data opened the door to applying a range of methods for detecting chaos that had been devised in the early 1980`s. Using attractor reconstruction, estimates of dynamical invariants, and comparisons between data and simulation of SEIR models, the ``case for chaos in childhood epidemics`` was made through a series of influential papers beginning in the mid 1980`s. The proposition that the precise timing and magnitude of epidemic outbreaks are deterministic but chaotic is appealing, since it raises the hope of finding determinism and simplicity beneath the apparently stochastic and complicated surface of the data. The initial enthusiasm for methods of detecting chaos in data has been followed by critical re-evaluations of their limitations. Early hopes of a ``one size fits all`` algorithm to diagnose chaos vs. noise in any data set have given way to a recognition that a variety of methods must be used, and interpretation of results must take into account the limitations of each method and the imperfections of the data. Our goals here are to outline some newer methods for detecting nonlinearity and chaos that have a solid statistical basis and are suited to epidemic data, and to begin a re-evaluation of the claims for nonlinear dynamics and chaos in epidemics using these newer methods. We also identify features of epidemic data that create problems for the older, better known methods of detecting chaos. When we ask ``are epidemics nonlinear?``, we are not questioning the existence of global nonlinearities in epidemic dynamics, such as nonlinear transmission rates. Our question is whether the data`s deviations from an annual cyclic trend (which would reflect global nonlinearities) are described by a linear, noise-driven stochastic process.

  17. Epidemics and rumours in complex networks

    CERN Document Server

    Draief, Moez

    2009-01-01

    Information propagation through peer-to-peer systems, online social systems, wireless mobile ad hoc networks and other modern structures can be modelled as an epidemic on a network of contacts. Understanding how epidemic processes interact with network topology allows us to predict ultimate course, understand phase transitions and develop strategies to control and optimise dissemination. This book is a concise introduction for applied mathematicians and computer scientists to basic models, analytical tools and mathematical and algorithmic results. Mathematical tools introduced include coupling

  18. Exploring the Universe with the Worldwide Telescope

    Science.gov (United States)

    Fay, J. E.

    2014-12-01

    Microsoft Research WorldWide Telescope is a software platform for exploring the universe. Whether you are a researcher, student or just a casual explorer WorldWide Telescope uses cutting edge technology to take you anywhere in the universe and visualize data collected by science programs from across the globe, including NASA great observatories and planetary probes. WWT leverages technologies such as Virtual reality headsets, multi-channel full dome projection and HTML5/WebGL to bring the WWT experience to any device and any scale. We will discuss how to use WWT to browse previously curated data, as well as how to process and visualize your own data, using examples from NASA Mars missions.

  19. CMS Centres Worldwide - a New Collaborative Infrastructure

    CERN Document Server

    Taylor, Lucas

    2011-01-01

    Webcasts, and generic Web tools such as CMS-TV for broadcasting live monitoring and outreach information. Being Web-based and experiment-independent, these systems could easily be extended to other organizations. We describe the experiences of using CMS Centres Worldwide in the CMS data-taking operations as well as for major media events with several hundred TV channels, radio stations, and many more press journalists simultaneously around the world.

  20. Worldwide variability in deceased organ donation registries

    OpenAIRE

    Rosenblum, Amanda M.; Li, Alvin Ho-ting; Roels, Leo; Stewart, Bryan; Prakash, Versha; Beitel, Janice; Young, Kimberly; Shemie, Sam; Nickerson, Peter; Garg, Amit X.

    2012-01-01

    The variability in deceased organ donation registries worldwide has received little attention. We considered all operating registries, where individual wishes about organ donation were recorded in a computerized database. We included registries which recorded an individual's decision to be a donor (donor registry), and registries which only recorded an individual's objection (non-donor registry). We collected information on 15 characteristics including history, design, use and number of regis...

  1. Reference worldwide model for antineutrinos from reactors

    OpenAIRE

    Baldoncini, Marica; Callegari, Ivan; Fiorentini, Giovanni; Mantovani, Fabio; Ricci, Barbara; Strati, Virginia; Xhixha, Gerti

    2014-01-01

    Antineutrinos produced at nuclear reactors constitute a severe source of background for the detection of geoneutrinos, which bring to the Earth's surface information about natural radioactivity in the whole planet. In this framework we provide a reference worldwide model for antineutrinos from reactors, in view of reactors operational records yearly published by the International Atomic Energy Agency (IAEA). We evaluate the expected signal from commercial reactors for ongoing (KamLAND and Bor...

  2. Worldwide Carsharing Growth: An International Comparison

    OpenAIRE

    Shaheen, Susan A; Cohen, Adam P.

    2008-01-01

    Carsharing (or short-term auto use) provides a flexible alternative that meets diverse transportation needs across the globe while reducing the negative impacts of private vehicle ownership. Although carsharing appeared in Europe between the 1940s and 1980s, the concept did not become popularized until the early 1990s. For nearly 20 years, worldwide participation in carsharing has been growing. Today, carsharing operates in approximately 600 cities around the world, in 18 nations and on 4 con...

  3. [The history of cholera epidemics in Israel].

    Science.gov (United States)

    Schwartz, Eli; Bar-El, Dan; Schur, Natan

    2005-05-01

    During the years 1831-1918 Israel (Palestine at that time) suffered from repeated cholera epidemics. The cholera epidemics were the major cause of severe health crisis among the population. The epidemics were transmitted by returening pilgrims returning from Mecca and, during the first world War, by the Turkish soldiers crossing the country. The disease caused panic amongst the population due to its high mortality rate. Quarantine which was the major measure taken by the government at that time was repeatedly broken by people trying to escape from the affected area. During the epidemic of 1902, patients were even reluctant to be treated by physicians as they were blamed for causing death. On the other hand, cholera was a major trigger for maintaining a better sanitation and establishing social relief systems within the communities. Most of the epidemics occurred in the old cities such as Jerusalem, Tiberia and Jaffa where infrastructure was inadequate. Cholera outbreaks were the trigger to build outside the old cities as in case of Jerusalem in which after the 1865 outbreak the city was expanded outside the walls. Since the end of the Ottoman period in Israel, cholera epidemics ceased, and except for very small occeasional small outbreaks, cholera is not seen here more.

  4. Phylodynamic analysis of HIV sub-epidemics in Mochudi, Botswana

    Directory of Open Access Journals (Sweden)

    Vlad Novitsky

    2015-12-01

    Real-time HIV genotyping and breaking down local HIV epidemics into phylogenetically distinct sub-epidemics may help to reveal the structure and dynamics of HIV transmission networks in communities, and aid in the design of targeted interventions for members of the acute sub-epidemics that likely fuel local HIV/AIDS epidemics.

  5. Suppressing epidemic spreading by risk-averse migration in dynamical networks

    Science.gov (United States)

    Yang, Han-Xin; Tang, Ming; Wang, Zhen

    2018-01-01

    In this paper, we study the interplay between individual behaviors and epidemic spreading in a dynamical network. We distribute agents on a square-shaped region with periodic boundary conditions. Every agent is regarded as a node of the network and a wireless link is established between two agents if their geographical distance is less than a certain radius. At each time, every agent assesses the epidemic situation and make decisions on whether it should stay in or leave its current place. An agent will leave its current place with a speed if the number of infected neighbors reaches or exceeds a critical value E. Owing to the movement of agents, the network's structure is dynamical. Interestingly, we find that there exists an optimal value of E leading to the maximum epidemic threshold. This means that epidemic spreading can be effectively controlled by risk-averse migration. Besides, we find that the epidemic threshold increases as the recovering rate increases, decreases as the contact radius increases, and is maximized by an optimal moving speed. Our findings offer a deeper understanding of epidemic spreading in dynamical networks.

  6. The malignant epidemic-changing patterns of trauma | Bowley ...

    African Journals Online (AJOL)

    Objectives and Setting. The worldwide burden of trauma is increasing, but is unequally distributed between nations. Trauma in South Africa targets the young and productive in society and imposes a major burden on the health infrastructure. We undertook a review of injury trends among patients attending the ...

  7. Epidemic spreading on activity-driven networks with attractiveness

    Science.gov (United States)

    Pozzana, Iacopo; Sun, Kaiyuan; Perra, Nicola

    2017-10-01

    We study SIS epidemic spreading processes unfolding on a recent generalization of the activity-driven modeling framework. In this model of time-varying networks, each node is described by two variables: activity and attractiveness. The first describes the propensity to form connections, while the second defines the propensity to attract them. We derive analytically the epidemic threshold considering the time scale driving the evolution of contacts and the contagion as comparable. The solutions are general and hold for any joint distribution of activity and attractiveness. The theoretical picture is confirmed via large-scale numerical simulations performed considering heterogeneous distributions and different correlations between the two variables. We find that heterogeneous distributions of attractiveness alter the contagion process. In particular, in the case of uncorrelated and positive correlations between the two variables, heterogeneous attractiveness facilitates the spreading. On the contrary, negative correlations between activity and attractiveness hamper the spreading. The results presented contribute to the understanding of the dynamical properties of time-varying networks and their effects on contagion phenomena unfolding on their fabric.

  8. Exact mean field dynamics for epidemic-like processes on heterogeneous networks

    CERN Document Server

    Lucas, Andrew

    2012-01-01

    We show that the mean field equations for the SIR epidemic can be exactly solved for a network with arbitrary degree distribution. Our exact solution consists of reducing the dynamics to a lone first order differential equation, which has a solution in terms of an integral over functions dependent on the degree distribution of the network, and reconstructing all mean field functions of interest from this integral. Irreversibility of the SIR epidemic is crucial for the solution. We also find exact solutions to the sexually transmitted disease SI epidemic on bipartite graphs, to a simplified rumor spreading model, and to a new model for recommendation spreading, via similar techniques. Numerical simulations of these processes on scale free networks demonstrate the qualitative validity of mean field theory in most regimes.

  9. Temperature profile and other data collected using bottle and CTD casts from the GASCOYNE and other platforms from a world-wide distribution during the California Cooperative Fisheries Investigation (CALCOFI) project, 14 November 1916 to 27 December 1961 (NODC Accession 6100000)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data and temperature, depth, and other data were collected using CTD and bottle casts from GASCOYNE and other platforms in a world-wide...

  10. Recent results on the spatiotemporal modelling and comparative analysis of Black Death and bubonic plague epidemics

    Science.gov (United States)

    Christakos, G.; Olea, R.A.; Yu, H.-L.

    2007-01-01

    Background: This work demonstrates the importance of spatiotemporal stochastic modelling in constructing maps of major epidemics from fragmentary information, assessing population impacts, searching for possible etiologies, and performing comparative analysis of epidemics. Methods: Based on the theory previously published by the authors and incorporating new knowledge bases, informative maps of the composite space-time distributions were generated for important characteristics of two major epidemics: Black Death (14th century Western Europe) and bubonic plague (19th-20th century Indian subcontinent). Results: The comparative spatiotemporal analysis of the epidemics led to a number of interesting findings: (1) the two epidemics exhibited certain differences in their spatiotemporal characteristics (correlation structures, trends, occurrence patterns and propagation speeds) that need to be explained by means of an interdisciplinary effort; (2) geographical epidemic indicators confirmed in a rigorous quantitative manner the partial findings of isolated reports and time series that Black Death mortality was two orders of magnitude higher than that of bubonic plague; (3) modern bubonic plague is a rural disease hitting harder the small villages in the countryside whereas Black Death was a devastating epidemic that indiscriminately attacked large urban centres and the countryside, and while the epidemic in India lasted uninterruptedly for five decades, in Western Europe it lasted three and a half years; (4) the epidemics had reverse areal extension features in response to annual seasonal variations. Temperature increase at the end of winter led to an expansion of infected geographical area for Black Death and a reduction for bubonic plague, reaching a climax at the end of spring when the infected area in Western Europe was always larger than in India. Conversely, without exception, the infected area during winter was larger for the Indian bubonic plague; (5) during the

  11. Recent results on the spatiotemporal modelling and comparative analysis of Black Death and bubonic plague epidemics.

    Science.gov (United States)

    Christakos, G; Olea, R A; Yu, H-L

    2007-09-01

    This work demonstrates the importance of spatiotemporal stochastic modelling in constructing maps of major epidemics from fragmentary information, assessing population impacts, searching for possible etiologies, and performing comparative analysis of epidemics. Based on the theory previously published by the authors and incorporating new knowledge bases, informative maps of the composite space-time distributions were generated for important characteristics of two major epidemics: Black Death (14th century Western Europe) and bubonic plague (19th-20th century Indian subcontinent). The comparative spatiotemporal analysis of the epidemics led to a number of interesting findings: (1) the two epidemics exhibited certain differences in their spatiotemporal characteristics (correlation structures, trends, occurrence patterns and propagation speeds) that need to be explained by means of an interdisciplinary effort; (2) geographical epidemic indicators confirmed in a rigorous quantitative manner the partial findings of isolated reports and time series that Black Death mortality was two orders of magnitude higher than that of bubonic plague; (3) modern bubonic plague is a rural disease hitting harder the small villages in the countryside whereas Black Death was a devastating epidemic that indiscriminately attacked large urban centres and the countryside, and while the epidemic in India lasted uninterruptedly for five decades, in Western Europe it lasted three and a half years; (4) the epidemics had reverse areal extension features in response to annual seasonal variations. Temperature increase at the end of winter led to an expansion of infected geographical area for Black Death and a reduction for bubonic plague, reaching a climax at the end of spring when the infected area in Western Europe was always larger than in India. Conversely, without exception, the infected area during winter was larger for the Indian bubonic plague; (5) during the Indian epidemic, the disease

  12. Predictability and epidemic pathways in global outbreaks of infectious diseases: the SARS case study

    Directory of Open Access Journals (Sweden)

    Barthélemy Marc

    2007-11-01

    Full Text Available Abstract Background The global spread of the severe acute respiratory syndrome (SARS epidemic has clearly shown the importance of considering the long-range transportation networks in the understanding of emerging diseases outbreaks. The introduction of extensive transportation data sets is therefore an important step in order to develop epidemic models endowed with realism. Methods We develop a general stochastic meta-population model that incorporates actual travel and census data among 3 100 urban areas in 220 countries. The model allows probabilistic predictions on the likelihood of country outbreaks and their magnitude. The level of predictability offered by the model can be quantitatively analyzed and related to the appearance of robust epidemic pathways that represent the most probable routes for the spread of the disease. Results In order to assess the predictive power of the model, the case study of the global spread of SARS is considered. The disease parameter values and initial conditions used in the model are evaluated from empirical data for Hong Kong. The outbreak likelihood for specific countries is evaluated along with the emerging epidemic pathways. Simulation results are in agreement with the empirical data of the SARS worldwide epidemic. Conclusion The presented computational approach shows that the integration of long-range mobility and demographic data provides epidemic models with a predictive power that can be consistently tested and theoretically motivated. This computational strategy can be therefore considered as a general tool in the analysis and forecast of the global spreading of emerging diseases and in the definition of containment policies aimed at reducing the effects of potentially catastrophic outbreaks.

  13. Estimating epidemic arrival times using linear spreading theory

    Science.gov (United States)

    Chen, Lawrence M.; Holzer, Matt; Shapiro, Anne

    2018-01-01

    We study the dynamics of a spatially structured model of worldwide epidemics and formulate predictions for arrival times of the disease at any city in the network. The model is composed of a system of ordinary differential equations describing a meta-population susceptible-infected-recovered compartmental model defined on a network where each node represents a city and the edges represent the flight paths connecting cities. Making use of the linear determinacy of the system, we consider spreading speeds and arrival times in the system linearized about the unstable disease free state and compare these to arrival times in the nonlinear system. Two predictions are presented. The first is based upon expansion of the heat kernel for the linearized system. The second assumes that the dominant transmission pathway between any two cities can be approximated by a one dimensional lattice or a homogeneous tree and gives a uniform prediction for arrival times independent of the specific network features. We test these predictions on a real network describing worldwide airline traffic.

  14. FluBreaks: early epidemic detection from Google flu trends.

    Science.gov (United States)

    Pervaiz, Fahad; Pervaiz, Mansoor; Abdur Rehman, Nabeel; Saif, Umar

    2012-10-04

    The Google Flu Trends service was launched in 2008 to track changes in the volume of online search queries related to flu-like symptoms. Over the last few years, the trend data produced by this service has shown a consistent relationship with the actual number of flu reports collected by the US Centers for Disease Control and Prevention (CDC), often identifying increases in flu cases weeks in advance of CDC records. However, contrary to popular belief, Google Flu Trends is not an early epidemic detection system. Instead, it is designed as a baseline indicator of the trend, or changes, in the number of disease cases. To evaluate whether these trends can be used as a basis for an early warning system for epidemics. We present the first detailed algorithmic analysis of how Google Flu Trends can be used as a basis for building a fully automated system for early warning of epidemics in advance of methods used by the CDC. Based on our work, we present a novel early epidemic detection system, called FluBreaks (dritte.org/flubreaks), based on Google Flu Trends data. We compared the accuracy and practicality of three types of algorithms: normal distribution algorithms, Poisson distribution algorithms, and negative binomial distribution algorithms. We explored the relative merits of these methods, and related our findings to changes in Internet penetration and population size for the regions in Google Flu Trends providing data. Across our performance metrics of percentage true-positives (RTP), percentage false-positives (RFP), percentage overlap (OT), and percentage early alarms (EA), Poisson- and negative binomial-based algorithms performed better in all except RFP. Poisson-based algorithms had average values of 99%, 28%, 71%, and 76% for RTP, RFP, OT, and EA, respectively, whereas negative binomial-based algorithms had average values of 97.8%, 17.8%, 60%, and 55% for RTP, RFP, OT, and EA, respectively. Moreover, the EA was also affected by the region's population size

  15. A network-based meta-population approach to model Rift Valley fever epidemics.

    Science.gov (United States)

    Xue, Ling; Scott, H Morgan; Cohnstaedt, Lee W; Scoglio, Caterina

    2012-08-07

    Rift Valley fever virus (RVFV) has been expanding its geographical distribution with important implications for both human and animal health. The emergence of Rift Valley fever (RVF) in the Middle East, and its continuing presence in many areas of Africa, has negatively impacted both medical and veterinary infrastructures and human morbidity, mortality, and economic endpoints. Furthermore, worldwide attention should be directed towards the broader infection dynamics of RVFV, because suitable host, vector and environmental conditions for additional epidemics likely exist on other continents; including Asia, Europe and the Americas. We propose a new compartmentalized model of RVF and the related ordinary differential equations to assess disease spread in both time and space; with the latter driven as a function of contact networks. Humans and livestock hosts and two species of vector mosquitoes are included in the model. The model is based on weighted contact networks, where nodes of the networks represent geographical regions and the weights represent the level of contact between regional pairings for each set of species. The inclusion of human, animal, and vector movements among regions is new to RVF modeling. The movement of the infected individuals is not only treated as a possibility, but also an actuality that can be incorporated into the model. We have tested, calibrated, and evaluated the model using data from the recent 2010 RVF outbreak in South Africa as a case study; mapping the epidemic spread within and among three South African provinces. An extensive set of simulation results shows the potential of the proposed approach for accurately modeling the RVF spreading process in additional regions of the world. The benefits of the proposed model are twofold: not only can the model differentiate the maximum number of infected individuals among different provinces, but also it can reproduce the different starting times of the outbreak in multiple locations

  16. Epidemics in networks with nodal self-infection and the epidemic threshold

    NARCIS (Netherlands)

    Van Mieghem, P.F.A.; Cator, E.

    2012-01-01

    Since the Susceptible-Infected-Susceptible (SIS) epidemic threshold is not precisely defined in spite of its practical importance, the classical SIS epidemic process has been generalized to the ??SIS model, where a node possesses a self-infection rate ?, in addition to a link infection rate ? and a

  17. Epidemic cycling in a multi-strain SIRS epidemic network model.

    Science.gov (United States)

    Zhang, Xu-Sheng

    2016-04-18

    One common observation in infectious diseases caused by multi-strain pathogens is that both the incidence of all infections and the relative fraction of infection with each strain oscillate with time (i.e., so-called Epidemic cycling). Many different mechanisms have been proposed for the pervasive nature of epidemic cycling. Nevertheless, the two facts that people contact each other through a network rather than following a simple mass-action law and most infectious diseases involve multiple strains have not been considered together for their influence on the epidemic cycling. To demonstrate how the structural contacts among people influences the dynamical patterns of multi-strain pathogens, we investigate a two strain epidemic model in a network where every individual randomly contacts with a fixed number of other individuals. The standard pair approximation is applied to describe the changing numbers of individuals in different infection states and contact pairs. We show that spatial correlation due to contact network and interactions between strains through both ecological interference and immune response interact to generate epidemic cycling. Compared to one strain epidemic model, the two strain model presented here can generate epidemic cycling within a much wider parameter range that covers many infectious diseases. Our results suggest that co-circulation of multiple strains within a contact network provides an explanation for epidemic cycling.

  18. Reviss to market Russian isotopes worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Latham, I.A. (Reviss services, Aylesbury (United Kingdom))

    1992-12-01

    The culmination of two years of detailed negotiations saw the formation of Reviss Services in April 1992. This joint venture company is a collaboration between Amersham International (Health Science Group), the Mayak Production Association (manufacturer of radioisotopes) and AO Techsnabexport (the Russian export agency). It is set up to enable a variety of Russian-manufactured radioisotopes to be marketed worldwide. Formation of the joint venture company was made possible by the recent political changes in the former Soviet Union, allowing the three parties to extend their long-standing commercial trading relationship into a full working partnership. (Author).

  19. Health warnings on tobacco products - worldwide, 2007.

    Science.gov (United States)

    2009-05-22

    Many countries require that tobacco product packaging includes health warnings about the risks associated with tobacco use. Health warnings on tobacco product packages are effective in highlighting the perception of health risk, supporting the intention to quit tobacco use, discouraging the intention to begin tobacco use, and increasing cessation rates. Prominent displays of health warnings increase their effectiveness; larger warnings, with pictures, are more likely to be noticed, better communicate health risks, provoke greater emotional response, and further motivate tobacco users to quit. This report assesses the current status of tobacco packaging health warning requirements worldwide. Governments could further discourage tobacco use by requiring prominent health warnings on tobacco packaging.

  20. El Nino-southern Oscillation and Lathyrism Epidemics

    Directory of Open Access Journals (Sweden)

    Olusegun Steven Ayodele Oluwole

    2015-09-01

    Full Text Available Epidemics of lathyrism, a neurological syndrome of spastic paraparesis, have occurredduring severe droughts in Europe, Asia, and Africa for millenia. Causation is linked toexposure to β-N-oxalyl-L-α,β-diaminopropionic acid (β-L-ODAP, a neurotoxin in Lathyrussativus. Lathyrism shares neurological features with konzo, a syndrome of predominantlyspastic paraparesis which occurs during droughts in East and Central Africa and is linked to El Nino activity. This study was done to determine the relationship of lathyrism epidemics to phases of El Nino-southern oscillation (ENSO and Pacific decadal oscillation (PDO, and to propose a model to explain why the geospatial distributions of lathyrism and konzo are non-overlapping. Contingency table of phases of ENSO and occurrence of lathyrism epidemics in Central Provinces, India from 1833–1902 was created and odds ratio was calculated. Wavelet spectra of time series of annual occurrence of lathyrism in Rewah district, India, and its coherence with ENSO and PDO from 1894–1920 were performed. Lathyrism epidemic was associated with El Nino phase of ENSO, odds ratio 378 (95 % 32–4475. Global spectra showed peaks at periodicity of 2.5 and 4.6 years for lathyrism; 2.7 and 5.0 years for PDO; and 2.5, 4.6, 7.0 years for ENSO. Spectrograms showed time-varying periodicities of 2.5–3.5 and 4.5–5.5 years for lathyrism; 2.0–3.0 and 6.5–9.0 years for ENSO; and 3.5 and 5.0 years for PDO, p < 0.0001. Spectral coherence were at 2.0–3.5 and 4.5–5.0 years for ENSO and lathyrism p < 0.0001, and 5.0 years for PDO and lathyrism p < 0.05. The droughts of El Ninos initiate dependence on Lathyrus sativus, which exposes the population to neurotoxic β-L-ODAP. Public health control of lathyrism epidemics should include development of models to forecast El Ninos and initiate food programmes in susceptible areas.

  1. Origins of food crops connect countries worldwide

    Science.gov (United States)

    Achicanoy, Harold A.; Bjorkman, Anne D.; Navarro-Racines, Carlos; Guarino, Luigi; Flores-Palacios, Ximena; Engels, Johannes M. M.; Wiersema, John H.; Dempewolf, Hannes; Sotelo, Steven; Ramírez-Villegas, Julian; Castañeda-Álvarez, Nora P.; Fowler, Cary; Jarvis, Andy; Rieseberg, Loren H.; Struik, Paul C.

    2016-01-01

    Research into the origins of food plants has led to the recognition that specific geographical regions around the world have been of particular importance to the development of agricultural crops. Yet the relative contributions of these different regions in the context of current food systems have not been quantified. Here we determine the origins (‘primary regions of diversity’) of the crops comprising the food supplies and agricultural production of countries worldwide. We estimate the degree to which countries use crops from regions of diversity other than their own (‘foreign crops’), and quantify changes in this usage over the past 50 years. Countries are highly interconnected with regard to primary regions of diversity of the crops they cultivate and/or consume. Foreign crops are extensively used in food supplies (68.7% of national food supplies as a global mean are derived from foreign crops) and production systems (69.3% of crops grown are foreign). Foreign crop usage has increased significantly over the past 50 years, including in countries with high indigenous crop diversity. The results provide a novel perspective on the ongoing globalization of food systems worldwide, and bolster evidence for the importance of international collaboration on genetic resource conservation and exchange.

  2. Worldwide variability in deceased organ donation registries.

    Science.gov (United States)

    Rosenblum, Amanda M; Li, Alvin Ho-Ting; Roels, Leo; Stewart, Bryan; Prakash, Versha; Beitel, Janice; Young, Kimberly; Shemie, Sam; Nickerson, Peter; Garg, Amit X

    2012-08-01

    The variability in deceased organ donation registries worldwide has received little attention. We considered all operating registries, where individual wishes about organ donation were recorded in a computerized database. We included registries which recorded an individual's decision to be a donor (donor registry), and registries which only recorded an individual's objection (non-donor registry). We collected information on 15 characteristics including history, design, use and number of registrants for 27 registries (68%). Most registries are nationally operated and government-owned. Registrations in five nations expire and require renewal. Some registries provide the option to make specific organ selections in the donation decision. Just over half of donor registries provide legally binding authorization to donation. In all national donor registries, except one, the proportion of adults (15+) registered is modest (donation decision mandatory to obtain a driver's license. Registered objections in non-donor registries are rare (organ donor registries worldwide necessitates public discourse and quality improvement initiatives, to identify and support leading practices in registry use. © 2012 The Authors. Transplant International © 2012 European Society for Organ Transplantation.

  3. Norovirus contamination found in oysters worldwide.

    Science.gov (United States)

    Cheng, Peter K C; Wong, Derek K K; Chung, Thomas W H; Lim, Wilina W L

    2005-08-01

    Noroviruses (Norwalk-like viruses) are recognized as major causes of acute gastroenteritis worldwide. Outbreaks of norovirus gastroenteritis are often associated with consumption of oysters. In this study, oysters imported into Hong Kong from 11 countries over a 3-year period were screened by RT-PCR. Overall, 53 out of 507 (10.5%) samples were positive for norovirus-RNA, and a wide variety of strains were found. Two novel genetic clusters were detected, which could indicate novel human or animal norovirus strains. However, whether these two new clusters are of human or animal origin is not known. Thirteen outbreaks, in which oysters were implicated as the source of infection were investigated: Norovirus RNA sequences could be detected in oysters from six outbreaks, but only in one outbreak the strains isolated from patients and oysters matched (>98% homology). Therefore, RT-PCR was of use in detecting norovirus contamination of oysters implicated in an outbreak, but was less useful in demonstrating an actual molecular epidemiological link with human cases. It was shown that contamination by noroviruses could be demonstrated in oysters worldwide, and therefore oysters may serve as an important vehicle for introducing novel norovirus strains. (c) 2005 Wiley-Liss, Inc.

  4. The nursing shortage: a worldwide problem

    Directory of Open Access Journals (Sweden)

    Rachel Z. Booth

    Full Text Available A worldwide shortage of nurses has been acknowledged by the multidisciplinary Global Advisory Group of the World Health Organization. The shortage is caused by an increased demand for nurses, while fewer people are choosing nursing as a profession and the current nurses worldwide are aging. The shortage applies to nurses in practice as well as the nurse faculty who teach students. The inter-country recruitment and migration of nurses from developing countries to developed countries exacerbates the problem. Although public opinion polls identifies the nurse as the person who makes the health care system work for them, the conditions of the work environment in which the nurse functions is unsatisfactory and must change. Numerous studies have shown the positive effects on the nurse of a healthy work environment and the positive relationships between nursing care and patient outcomes. It is important that government officials, insurance companies, and administrators and leaders of health care systems acknowledge and operationalize the value of nurses to the health care system in order to establish and maintain the integrity and viability of that system.

  5. The nursing shortage: a worldwide problem

    Directory of Open Access Journals (Sweden)

    Booth Rachel Z.

    2002-01-01

    Full Text Available A worldwide shortage of nurses has been acknowledged by the multidisciplinary Global Advisory Group of the World Health Organization. The shortage is caused by an increased demand for nurses, while fewer people are choosing nursing as a profession and the current nurses worldwide are aging. The shortage applies to nurses in practice as well as the nurse faculty who teach students. The inter-country recruitment and migration of nurses from developing countries to developed countries exacerbates the problem. Although public opinion polls identifies the nurse as the person who makes the health care system work for them, the conditions of the work environment in which the nurse functions is unsatisfactory and must change. Numerous studies have shown the positive effects on the nurse of a healthy work environment and the positive relationships between nursing care and patient outcomes. It is important that government officials, insurance companies, and administrators and leaders of health care systems acknowledge and operationalize the value of nurses to the health care system in order to establish and maintain the integrity and viability of that system.

  6. COURSE FEATURES EPIDEMIC PROCESS HIV INFECTION IN KHARKIV REGION

    Directory of Open Access Journals (Sweden)

    Nikolaeva LG

    2016-03-01

    Full Text Available Introduction. In the context of the transformation of the spheres of human living epidemic HIV-infection continues. According to the intensity of the epidemic process of HIV-infection, Ukraine takes one of the first places among the European countries. The epidemic process of the infection is concentrated mainly on the high-risk groups, and there is uneven prevalence. Besides in most cases this distribution can not be explained by the social and economic characteristics of certain territories. Kharkiv region belongs to the territory of Ukraine with the lowest prevalence level of HIV-infection. Though in terms of the social and economic crisis due to hostilities in the east of the country, which the region borders, the epidemic situation may significantly become worse. Work objective: to study the peculiarities of the course of the epidemic process of HIV-infection for the period from 1987 till 2015 in Kharkiv region that will improve the epidemiological surveillance of the infection and develop appropriate preventive measures in modern conditions. Material & methods. The studies were conducted in Kharkiv region, which is a big industrial and administrative center. The city of Kharkiv is located at the crossroads of drug trafficking from Asia and Russia. The reportings and analytics of the Kharkiv regional center for prevention and control of AIDS and the Ministry of Health of Ukraine for the period of 1987 – 2015 were used in the research. The analysis of incidence of HIV prevalence, structure of transmission routes and sex-age groups were carried out using descriptive and evaluative and analytical ways of epidemiological research method. Results & discussion. During 1987 – 2015 in Kharkiv region there were officially registered 7868 cases of HIV-infection what was equal to 4.0 % of the registered cases in Ukraine. Since 1996 a marked upward tendency of the incidence of HIV infection in Kharkiv region (growth rate – +7.0 %, and on the

  7. Emergence and global spread of epidemic healthcare-associated Clostridium difficile.

    Science.gov (United States)

    He, Miao; Miyajima, Fabio; Roberts, Paul; Ellison, Louise; Pickard, Derek J; Martin, Melissa J; Connor, Thomas R; Harris, Simon R; Fairley, Derek; Bamford, Kathleen B; D'Arc, Stephanie; Brazier, Jon; Brown, Derek; Coia, John E; Douce, Gill; Gerding, Dale; Kim, Hee Jung; Koh, Tse Hsien; Kato, Haru; Senoh, Mitsutoshi; Louie, Tom; Michell, Stephen; Butt, Emma; Peacock, Sharon J; Brown, Nick M; Riley, Tom; Songer, Glen; Wilcox, Mark; Pirmohamed, Munir; Kuijper, Ed; Hawkey, Peter; Wren, Brendan W; Dougan, Gordon; Parkhill, Julian; Lawley, Trevor D

    2013-01-01

    Epidemic C. difficile (027/BI/NAP1) has rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key events in evolutionary history leading to its emergence and the subsequent patterns of global spread remain unknown. Here, we define the global population structure of C. difficile 027/BI/NAP1 using whole-genome sequencing and phylogenetic analysis. We show that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought, emerged in North America within a relatively short period after acquiring the same fluoroquinolone resistance-conferring mutation and a highly related conjugative transposon. The two epidemic lineages showed distinct patterns of global spread, and the FQR2 lineage spread more widely, leading to healthcare-associated outbreaks in the UK, continental Europe and Australia. Our analysis identifies key genetic changes linked to the rapid transcontinental dissemination of epidemic C. difficile 027/BI/NAP1 and highlights the routes by which it spreads through the global healthcare system.

  8. Epidemic spreading with information-driven vaccination

    Science.gov (United States)

    Ruan, Zhongyuan; Tang, Ming; Liu, Zonghua

    2012-09-01

    Epidemic spreading has been well studied in the past decade, where the main concentration is focused on the influence of network topology but little attention is paid to the individual's crisis awareness. We here study how the crisis awareness, i.e., personal self-protection, influences the epidemic spreading by presenting a susceptible-infected-recovered model with information-driven vaccination. We introduce two parameters to quantitatively characterize the crisis awareness. One is the information creation rate λ and the other is the information sensitivity η. We find that the epidemic spreading can be significantly suppressed in both the homogeneous and heterogeneous networks when both λ and η are relatively large. More interesting is that the needed vaccine will be significantly reduced when the information is well spread, which is a good news for the poor countries and regions with limited resources.

  9. The epidemic of Tuberculosis on vaccinated population

    Science.gov (United States)

    Syahrini, Intan; Sriwahyuni; Halfiani, Vera; Meurah Yuni, Syarifah; Iskandar, Taufiq; Rasudin; Ramli, Marwan

    2017-09-01

    Tuberculosis is an infectious disease which has caused a large number of mortality in Indonesia. This disease is caused by Mycrobacterium tuberculosis. Besides affecting lung, this disease also affects other organs such as lymph gland, intestine, kidneys, uterus, bone, and brain. This article discusses the epidemic of tuberculosis through employing the SEIR model. Here, the population is divided into four compartments which are susceptible, exposed, infected and recovered. The susceptible population is further grouped into two which are vaccinated group and unvaccinated group. The behavior of the epidemic is investigated through analysing the equilibrium of the model. The result shows that administering vaccine to the susceptible population contributes to the reduction of the tuberculosis epidemic rate.

  10. Urgent epidemic control mechanism for aviation networks

    KAUST Repository

    Peng, Chengbin

    2011-01-01

    In the current century, the highly developed transportation system can not only boost the economy, but also greatly accelerate the spreading of epidemics. While some epidemic diseases may infect quite a number of people ahead of our awareness, the health care resources such as vaccines and the medical staff are usually locally or even globally insufficient. In this research, with the network of major aviation routes as an example, we present a method to determine the optimal locations to allocate the medical service in order to minimize the impact of the infectious disease with limited resources. Specifically, we demonstrate that when the medical resources are insufficient, we should concentrate our efforts on the travelers with the objective of effectively controlling the spreading rate of the epidemic diseases. © 2011 Springer-Verlag Berlin Heidelberg.

  11. Hysteroscopic sterilization: 10-year retrospective analysis of worldwide pregnancy reports.

    Science.gov (United States)

    Munro, M G; Nichols, J E; Levy, B; Vleugels, M P H; Veersema, S

    2014-01-01

    To identify factors that might contribute to pregnancies reported after hysteroscopic sterilization worldwide. Retrospective review of commercial data compiled from the MAUDE database, medical literature, and manufacturer reports received during commercial distribution of hysteroscopic sterilization micro-inserts from 2001 through 2010 (Canadian Taskforce classification III descriptive study). From 2001 through 2010, 497 305 hysteroscopic sterilization kits were distributed worldwide, and 748 pregnancies were reported, i.e., 0.15% of the estimated user population based on the number of distributed kits. The data were sufficient to enable analysis of 508 pregnancies for potential contributing factors and showed most to be associated with patient or physician noncompliance (n = 264) or misinterpreted confirmation tests (n = 212). Conceptions deemed to have occurred within 2 weeks of the procedure and therefore too early for detection were identified in 32 cases. Although there are limitations to the dataset and the study design is retrospective, it represents the largest body of cumulative hysteroscopic sterilization data available to date. Of the 748 pregnancies reported, it is apparent that some might have been prevented with greater patient and clinician attention to interim contraceptive use and counseling and with more rigorous evaluation and informed interpretation of the procedure confirmation tests. Although the estimated pregnancy rate based on such a dataset is likely an underestimation, it does suggest that the evaluable field performance of hysteroscopic sterilization micro-inserts is consistent with the labeled age-adjusted effectiveness of 99.74% at 5 years. Copyright © 2014 AAGL. Published by Elsevier Inc. All rights reserved.

  12. Seasonal Influenza Epidemics and El Ninos

    Directory of Open Access Journals (Sweden)

    Olusegun Steven Ayodele Oluwole

    2015-11-01

    Full Text Available Seasonal influenza epidemics occur annually during the winter in the north and south hemispheres, but timing of peaks and severity vary seasonally. Low humidity, which enhances survival and transmission of influenza virus, is the major risk factor. Both El Nino and La Nina phases of El Nino-southern oscillation (ENSO, which determine inter-annual variation of precipitation, are putative risk factors. This study was done to determine if seasonality, timing of peak, and severity of influenza epidemics are coupled to phases of ENSO. Monthly time series of positive specimens for influenza viruses and of multivariate El Nino-Southern Oscillation Index from January 2000 to August 2015 were analyzed. Seasonality, wavelet spectra, and cross wavelet spectra analyses were performed. Of 31 countries in the dataset, 21 were in north hemisphere and 10 in south hemisphere. Highest number of influenza occurred in January in the north hemisphere, but in July in the south hemisphere, p < 0.0001. Seasonal influenza epidemic was coupled to El Nino, while low occurrence was coupled to La Nina. The moderate La Nina of 2010–2011 was followed by weak seasonal influenza epidemic. The influenza pandemic of 2009–2010 followed the moderate El Nino of 2009–2010, which had three peaks. Spectrograms showed time varying periodicities of 6–48 months for ENSO, 6–24 months for north hemisphere influenza, and 6–12 months for south hemisphere influenza. Cross spectrograms showed time varying periodicities at 6–36 months for ENSO and influenza in both hemispheres, p < 0.0001. Phase plots showed that influenza time series lagged ENSO in both hemispheres. Severity of seasonal influenza increases during El Nino, but decreases during La Nina. Coupling of seasonality, timing, and severity of influenza epidemics to the strength and waveform of ENSO indicate that forecast models of El Nino should be integrated into surveillance programmes for influenza epidemics.

  13. Deriving a model for influenza epidemics from historical data.

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Jaideep; Lefantzi, Sophia

    2011-09-01

    In this report we describe how we create a model for influenza epidemics from historical data collected from both civilian and military societies. We derive the model when the population of the society is unknown but the size of the epidemic is known. Our interest lies in estimating a time-dependent infection rate to within a multiplicative constant. The model form fitted is chosen for its similarity to published models for HIV and plague, enabling application of Bayesian techniques to discriminate among infectious agents during an emerging epidemic. We have developed models for the progression of influenza in human populations. The model is framed as a integral, and predicts the number of people who exhibit symptoms and seek care over a given time-period. The start and end of the time period form the limits of integration. The disease progression model, in turn, contains parameterized models for the incubation period and a time-dependent infection rate. The incubation period model is obtained from literature, and the parameters of the infection rate are fitted from historical data including both military and civilian populations. The calibrated infection rate models display a marked difference in which the 1918 Spanish Influenza pandemic differed from the influenza seasons in the US between 2001-2008 and the progression of H1N1 in Catalunya, Spain. The data for the 1918 pandemic was obtained from military populations, while the rest are country-wide or province-wide data from the twenty-first century. We see that the initial growth of infection in all cases were about the same; however, military populations were able to control the epidemic much faster i.e., the decay of the infection-rate curve is much higher. It is not clear whether this was because of the much higher level of organization present in a military society or the seriousness with which the 1918 pandemic was addressed. Each outbreak to which the influenza model was fitted yields a separate set of

  14. Prediction of meningococcal meningitis epidemics in western Africa by using climate information

    Science.gov (United States)

    YAKA, D. P.; Sultan, B.; Tarbangdo, F.; Thiaw, W. M.

    2013-12-01

    The variations of certain climatic parameters and the degradation of ecosystems, can affect human's health by influencing the transmission, the spatiotemporal repartition and the intensity of infectious diseases. It is mainly the case of meningococcal meningitis (MCM) whose epidemics occur particularly in Sahelo-Soudanian climatic area of Western Africa under quite particular climatic conditions. Meningococcal Meningitis (MCM) is a contagious infection disease due to the bacteria Neisseria meningitis. MCM epidemics occur worldwide but the highest incidence is observed in the "meningitis belt" of sub-Saharan Africa, stretching from Senegal to Ethiopia. In spite of standards, strategies of prevention and control of MCS epidemic from World Health Organization (WHO) and States, African Sahelo-Soudanian countries remain frequently afflicted by disastrous epidemics. In fact, each year, during the dry season (February-April), 25 to 250 thousands of cases are observed. Children under 15 are particularly affected. Among favourable conditions for the resurgence and dispersion of the disease, climatic conditions may be important inducing seasonal fluctuations in disease incidence and contributing to explain the spatial pattern of the disease roughly circumscribed to the ecological Sahelo-Sudanian band. In this study, we tried to analyse the relationships between climatic factors, ecosystems degradation and MCM for a better understanding of MCM epidemic dynamic and their prediction. We have shown that MCM epidemics, whether at the regional, national or local level, occur in a specific period of the year, mainly from January to May characterised by a dry, hot and sandy weather. We have identified both in situ (meteorological synoptic stations) and satellitales climatic variables (NCEP reanalysis dataset) whose seasonal variability is dominating in MCM seasonal transmission. Statistical analysis have measured the links between seasonal variation of certain climatic parameters

  15. Climate Change Impacts on Worldwide Coffee Production

    Science.gov (United States)

    Foreman, T.; Rising, J. A.

    2015-12-01

    Coffee (Coffea arabica and Coffea canephora) plays a vital role in many countries' economies, providing necessary income to 25 million members of tropical countries, and supporting a $81 billion industry, making it one of the most valuable commodities in the world. At the same time, coffee is at the center of many issues of sustainability. It is vulnerable to climate change, with disease outbreaks becoming more common and suitable regions beginning to shift. We develop a statistical production model for coffee which incorporates temperature, precipitation, frost, and humidity effects using a new database of worldwide coffee production. We then use this model to project coffee yields and production into the future based on a variety of climate forecasts. This model can then be used together with a market model to forecast the locations of future coffee production as well as future prices, supply, and demand.

  16. Worldwide trends in diabetes since 1980

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Andersen, Lars Bo; Bugge, Anna

    2016-01-01

    prevalence-defined as fasting plasma glucose of 7.0 mmol/L or higher, or history of diagnosis with diabetes, or use of insulin or oral hypoglycaemic drugs-in 200 countries and territories in 21 regions, by sex and from 1980 to 2014. We also calculated the posterior probability of meeting the global diabetes......BACKGROUND: One of the global targets for non-communicable diseases is to halt, by 2025, the rise in the age-standardised adult prevalence of diabetes at its 2010 levels. We aimed to estimate worldwide trends in diabetes, how likely it is for countries to achieve the global target, and how changes...... in prevalence, together with population growth and ageing, are affecting the number of adults with diabetes. METHODS: We pooled data from population-based studies that had collected data on diabetes through measurement of its biomarkers. We used a Bayesian hierarchical model to estimate trends in diabetes...

  17. Cell therapy worldwide: an incipient revolution.

    Science.gov (United States)

    Rao, Mahendra; Mason, Chris; Solomon, Susan

    2015-01-01

    The regenerative medicine field is large, diverse and active worldwide. A variety of different organizational and product models have been successful, and pioneering entrepreneurs have shown both what can work and, critically, what does not. Evolving regulations, novel funding mechanisms combined with new technological breakthroughs are keeping the field in a state of flux. The field struggles to cope with the lack of infrastructure and investment, it nevertheless has evolved from its roots in human stem cell therapy and tissue and organ transplants to a field composed of a variety of products from multiple cell sources with approval for use in numerous countries. Currently, tens of thousands of patients have been treated with some kind of cell therapy.

  18. World-Wide Web the information universe

    CERN Document Server

    Berners-Lee, Tim; Groff, Jean-Francois; Pollermann, Bernd

    1992-01-01

    Purpose - The World-Wide Web (W-3) initiative is a practical project designed to bring a global information universe into existence using available technology. This paper seeks to describe the aims, data model, and protocols needed to implement the "web" and to compare them with various contemporary systems. Design/methodology/approach - Since Vannevar Bush's article, men have dreamed of extending their intellect by making their collective knowledge available to each individual by using machines. Computers provide us two practical techniques for human-knowledge interface. One is hypertext, in which links between pieces of text (or other media) mimic human association of ideas. The other is text retrieval, which allows associations to be deduced from the content of text. The W-3 ideal world allows both operations and provides access from any browsing platform. Findings - Various server gateways to other information systems have been produced, and the total amount of information available on the web is...

  19. Epidemic spreading with immunization on bipartite networks

    CERN Document Server

    Tanimoto, Shinji

    2011-01-01

    Bipartite networks are composed of two types of nodes and there are no links between nodes of the same type. Thus the study of epidemic spread and control on such networks is relevant to sexually transmitted diseases (STDs). When entire populations of two types cannot be immunized and the effect of immunization is not perfect, we have to consider the targeted immunization with immunization rates. We derive the epidemic thresholds of SIR and SIS models with immunization and illustrate the results with STDs on heterosexual contact networks.

  20. Worldwide Survey of Nutritional Practices in PICUs.

    Science.gov (United States)

    Kerklaan, Dorian; Fivez, Tom; Mehta, Nilesh M; Mesotten, Dieter; van Rosmalen, Joost; Hulst, Jessie M; Van den Berghe, Greet; Joosten, Koen F M; Verbruggen, Sascha C A T

    2016-01-01

    To assess current nutritional practices in critically ill children worldwide. A two-part online, international survey. The first part, "the survey", was composed of 59 questions regarding nutritional strategies and protocols (July-November 2013). The second part surveyed the "point prevalence" of nutritional data of patients present in a subgroup of the responding PICUs (May-September 2014). Members of the World Federation of Pediatric Intensive and Critical Care Societies were asked to complete the survey. Pediatric critical care providers. Survey. We analyzed 189 responses from 156 PICUs in 52 countries (survey). We received nutritional data on 295 patients from 41 of these 156 responding PICUs in 27 countries (point prevalence). According to the "survey", nutritional protocols and support teams were available in 52% and 57% of the PICUs, respectively. Various equations were in use to estimate energy requirements; only in 14% of PICUs, indirect calorimetry was used. Nutritional targets for macronutrients, corrected for age/weight, varied widely. Enteral nutrition would be started early (within 24 hr of admission) in 60% of PICUs, preferably by the gastric route (88%). In patients intolerant to enteral nutrition, parenteral nutrition would be started within 48 hours in 55% of PICUs. Overall, in 72% of PICUs supplemental parenteral nutrition would be used if enteral nutrition failed to meet at least 50% of energy delivery goal. Several differences between the intended (survey) and the actual (point prevalence) nutritional practices were found in the responding PICUs, predominantly overestimating the ability to adequately feed patients. Nutritional practices vary widely between PICUs worldwide. There are significant differences in macronutrient goals, estimating energy requirements, timing of nutrient delivery, and threshold for supplemental parenteral nutrition. Uniform consensus-based nutrition practices, preferably guided by evidence, are desirable in the PICU.

  1. DEVELOPMENT OF WOOD-BASED PRODUCTS WORLDWIDE

    Directory of Open Access Journals (Sweden)

    Marius C. BARBU

    2015-12-01

    Full Text Available The tendency in recent decades for manufacturing plants of semi-finished products such as composite panels, has been to invest in order to achieve high production capacities (>2,000 m³/day for panels and >3,000 t/day for paper with one line. The trend of concentrating the primary processing capacities and manufacturing wood-based panels will continue for the next few years not only in Europe but in North and South America as well. The ten largest panel manufacturers had a combined manufacturing capacity that exceeded a third of the worldwide production capacity. The financial crisis that started in 2008 has caused the closure of a large number of factories especially in North America and Central Europe. Small- and medium-sized producers will only survive if they will continue to specialize in the manufacture of panel types and sizes (niche products that are “unprofitable” for mega-groups. The installed production capacity worldwide of all wood-based composite panels combined (includes PY, PB, MDF, OSB rose by more than 2.5 times between 1980 and 2005 (225 mil.m³, and continues to increase despite the crises reaching approx. 300 mil.m³ in 2013. The forecast for the coming years varies greatly from continent to continent. In North America and Central Europe, both a consolidation of the available production capacities and the closure of less efficient older lines are expected. The lowest point of the effect of the financial crisis on the building industry seems to have been overcome. The furniture production companies will continue to move from one continent and region to another.

  2. The threshold of a stochastic avian-human influenza epidemic model with psychological effect

    Science.gov (United States)

    Zhang, Fengrong; Zhang, Xinhong

    2018-02-01

    In this paper, a stochastic avian-human influenza epidemic model with psychological effect in human population and saturation effect within avian population is investigated. This model describes the transmission of avian influenza among avian population and human population in random environments. For stochastic avian-only system, persistence in the mean and extinction of the infected avian population are studied. For the avian-human influenza epidemic system, sufficient conditions for the existence of an ergodic stationary distribution are obtained. Furthermore, a threshold of this stochastic model which determines the outcome of the disease is obtained. Finally, numerical simulations are given to support the theoretical results.

  3. Lessons Learned from Microgrid Demonstrations Worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Marnay, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Qu, Min [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Romankiewicz, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-01-31

    The survey leads to policy recommendations for starting a microgrid demonstration program and overall development of microgrid and distributed energy. Additionally, specific recommendations have been made for China specifically.

  4. The worldwide costs of dementia 2015 and comparisons with 2010.

    Science.gov (United States)

    Wimo, Anders; Guerchet, Maëlenn; Ali, Gemma-Claire; Wu, Yu-Tzu; Prina, A Matthew; Winblad, Bengt; Jönsson, Linus; Liu, Zhaorui; Prince, Martin

    2017-01-01

    In 2010, Alzheimer's Disease International presented estimates of the global cost of illness (COI) of dementia. Since then, new studies have been conducted, and the number of people with dementia has increased. Here, we present an update of the global cost estimates. This is a societal, prevalence-based global COI study. The worldwide costs of dementia were estimated at United States (US) $818 billion in 2015, an increase of 35% since 2010; 86% of the costs occur in high-income countries. Costs of informal care and the direct costs of social care still contribute similar proportions of total costs, whereas the costs in the medical sector are much lower. The threshold of US $1 trillion will be crossed by 2018. Worldwide costs of dementia are enormous and still inequitably distributed. The increase in costs arises from increases in numbers of people with dementia and in increases in per person costs. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. An insight into the epidemiology of dolphin morbillivirus worldwide.

    Science.gov (United States)

    Van Bressem, M; Waerebeek, K V; Jepson, P D; Raga, J A; Duignan, P J; Nielsen, O; Di Beneditto, A P; Siciliano, S; Ramos, R; Kant, W; Peddemors, V; Kinoshita, R; Ross, P S; López-Fernandez, A; Evans, K; Crespo, E; Barrett, T

    2001-08-20

    Serum samples from 288 cetaceans representing 25 species and originating from 11 different countries were collected between 1995 and 1999 and examined for the presence of dolphin morbillivirus (DMV)-specific antibodies by an indirect ELISA (iELISA) (N = 267) or a plaque reduction assay (N = 21). A total of 35 odontocetes were seropositive: three harbour porpoises (Phocoena phocoena) and a common dolphin (Delphinus delphis) from the Northeastern (NE) Atlantic, a bottlenose dolphin (Tursiops truncatus) from Kent (England), three striped dolphins (Stenella coeruleoalba), two Risso's dolphins (Grampus griseus) and a bottlenose dolphin from the Mediterranean Sea, one common dolphin from the Southwest (SW) Indian Ocean, three Fraser's dolphins (Lagenodelphis hosei) from the SW Atlantic, 18 long-finned pilot whales (Globicephala melas) and a bottlenose dolphin from the SW Pacific as well as a captive bottlenose dolphin (Tursiops aduncus) originally from Taiwan. The presence of morbillivirus antibodies in 17 of these animals was further examined in other iELISAs and virus neutralization tests. Our results indicate that DMV infects cetaceans worldwide. This is the first report of DMV-seropositive animals from the SW Indian, SW Atlantic and West Pacific Oceans. Prevalence of DMV-seropositives was 85.7% in 21 pilot whales from the SW Pacific and both sexually mature and immature individuals were infected. This indicates that DMV is endemic in these animals. The same situation may occur among Fraser's dolphins from the SW Atlantic. The prevalence of DMV-seropositives was 5.26% and 5.36% in 19 common dolphins and 56 harbour porpoise from the NE Atlantic, respectively, and 18.75% in 16 striped dolphins from the Mediterranean. Prevalence varied significantly with sexual maturity in harbour porpoises and striped dolphins; all DMV-seropositives being mature animals. The prevalence of seropositive harbour porpoise and striped dolphins appeared to have decreased since previous

  6. iTRAQ-based comparative proteomic analysis of Vero cells infected with virulent and CV777 vaccine strain-like strains of porcine epidemic diarrhea virus.

    Science.gov (United States)

    Guo, Xiaozhen; Hu, Han; Chen, Fangzhou; Li, Zhonghua; Ye, Shiyi; Cheng, Shuang; Zhang, Mengjia; He, Qigai

    2016-01-01

    The re-emerging porcine epidemic diarrhea virus (PEDV) variant related diarrhea has been documented in China since late 2010 and now with global distribution. Currently, a virulent PEDV CH/YNKM-8/2013 and a CV777 vaccine strain-like AH-M have been successfully isolated from the clinical samples. To dissect out the underlying pathogenic mechanism of virulent PEDV and clarify the differences between virulent and CV777 vaccine strain-like PEDV infections, we performed an iTRAQ-based comparative quantitative proteomic study of Vero cells infected with both PEDV strains. A total of 661 and 474 differentially expressed proteins were identified upon virulent and CV777 vaccine strain-like isolates infection, respectively. Ingenuity Pathway Analysis was employed to investigate the canonical pathways and functional networks involved in both PEDV infections. Comprehensive studies have revealed that the PEDV virulent strain suppressed protein synthesis of Vero cells through down-regulating mTOR as well as its downstream targets 4EBP1 and p70S6K activities, which were validated by immunoblotting. In addition, the virulent strain could activate NF-κB pathway more intensively than the CV777 vaccine strain-like isolate, and elicit stronger inflammatory cascades as well. These data might provide new insights for elucidating the specific pathogenesis of PEDV infection, and pave the way for the development of effective therapeutic strategies. Porcine epidemic diarrhea is now worldwide distributed and causing huge economic losses to swine industry. The immunomodulation and pathogenesis between PEDV and host, as well as the difference between virulent and attenuated strains of PEDV infections are still largely unknown. In this study, we presented for the first application of proteomic analysis to compare whole cellular protein alterations induced by virulent and CV777 vaccine strain-like PEDV infections, which might contribute to understand the pathogenesis of PEDV and anti

  7. Identification of specific gene sequences conserved in contemporary epidemic strains of Salmonella enterica.

    Science.gov (United States)

    Kang, Min-Su; Besser, Thomas E; Hancock, Dale D; Porwollik, Steffen; McClelland, Michael; Call, Douglas R

    2006-11-01

    Genetic elements specific to recent and contemporary epidemic strains of Salmonella enterica were identified using comparative genomic analysis. Two epidemic multidrug-resistant (MDR) strains, MDR Salmonella enterica serovar Typhimurium definitive phage type 104 (DT104) and cephalosporin-resistant MDR Salmonella enterica serovar Newport, and an epidemic pansusceptible strain, Salmonella serovar Typhimurium DT160, were subjected to Salmonella gene microarray and suppression subtractive hybridization analyses. Their genome contents were compared with those of coexisting sporadic strains matched by serotype, geographic and temporal distribution, and host species origin. These paired comparisons revealed that epidemic strains of S. enterica had specific genes and gene regions that were shared by isolates of the same subtype. Most of these gene sequences are related to mobile genetic elements, including phages, plasmids, and plasmid-like and transposable elements, and some genes may encode proteins conferring growth or survival advantages. The emergence of epidemic MDR strains may therefore be associated with the presence of fitness-associated genetic factors in addition to their antimicrobial resistance genes.

  8. Modeling the worldwide spread of pandemic influenza: baseline case and containment interventions.

    Directory of Open Access Journals (Sweden)

    Vittoria Colizza

    2007-01-01

    Full Text Available BACKGROUND: The highly pathogenic H5N1 avian influenza virus, which is now widespread in Southeast Asia and which diffused recently in some areas of the Balkans region and Western Europe, has raised a public alert toward the potential occurrence of a new severe influenza pandemic. Here we study the worldwide spread of a pandemic and its possible containment at a global level taking into account all available information on air travel. METHODS AND FINDINGS: We studied a metapopulation stochastic epidemic model on a global scale that considers airline travel flow data among urban areas. We provided a temporal and spatial evolution of the pandemic with a sensitivity analysis of different levels of infectiousness of the virus and initial outbreak conditions (both geographical and seasonal. For each spreading scenario we provided the timeline and the geographical impact of the pandemic in 3,100 urban areas, located in 220 different countries. We compared the baseline cases with different containment strategies, including travel restrictions and the therapeutic use of antiviral (AV drugs. We investigated the effect of the use of AV drugs in the event that therapeutic protocols can be carried out with maximal coverage for the populations in all countries. In view of the wide diversity of AV stockpiles in different regions of the world, we also studied scenarios in which only a limited number of countries are prepared (i.e., have considerable AV supplies. In particular, we compared different plans in which, on the one hand, only prepared and wealthy countries benefit from large AV resources, with, on the other hand, cooperative containment scenarios in which countries with large AV stockpiles make a small portion of their supplies available worldwide. CONCLUSIONS: We show that the inclusion of air transportation is crucial in the assessment of the occurrence probability of global outbreaks. The large-scale therapeutic usage of AV drugs in all hit

  9. Complementarity of statstical treatments to reconstruct worldwide routes of invasion

    DEFF Research Database (Denmark)

    Lombaert, Eric; Guillemaud, Thomas; Lundgren, Jonathan

    2014-01-01

    area, necessitating the use of alternative methods and an intense sampling design. In this study, we made inferences about the worldwide invasion history of the ladybird Harmonia axyridis by various population genetics statistical methods, using a large set of sampling sites distributed over most......Inferences about introduction histories of invasive species remain challenging because of the stochastic demographic processes involved. Approximate Bayesian computation (ABC) can help to overcome these problems, but such method requires a prior understanding of population structure over the study...... of the species’ native and invaded areas. We evaluated the complementarity of the statistical methods and the consequences of using different sets of site samples for ABC inferences. We found that the H. axyridis invasion has involved two bridgehead invasive populations in North America, which have served...

  10. Ethical pharmaceutical promotion and communications worldwide: codes and regulations

    Science.gov (United States)

    2014-01-01

    The international pharmaceutical industry has made significant efforts towards ensuring compliant and ethical communication and interaction with physicians and patients. This article presents the current status of the worldwide governance of communication practices by pharmaceutical companies, concentrating on prescription-only medicines. It analyzes legislative, regulatory, and code-based compliance control mechanisms and highlights significant developments, including the 2006 and 2012 revisions of the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) Code of Practice. Developments in international controls, largely built upon long-established rules relating to the quality of advertising material, have contributed to clarifying the scope of acceptable company interactions with healthcare professionals. This article aims to provide policy makers, particularly in developing countries, with an overview of the evolution of mechanisms governing the communication practices, such as the distribution of promotional or scientific material and interactions with healthcare stakeholders, relating to prescription-only medicines. PMID:24679064

  11. Ethical pharmaceutical promotion and communications worldwide: codes and regulations.

    Science.gov (United States)

    Francer, Jeffrey; Izquierdo, Jose Zamarriego; Music, Tamara; Narsai, Kirti; Nikidis, Chrisoula; Simmonds, Heather; Woods, Paul

    2014-03-29

    The international pharmaceutical industry has made significant efforts towards ensuring compliant and ethical communication and interaction with physicians and patients. This article presents the current status of the worldwide governance of communication practices by pharmaceutical companies, concentrating on prescription-only medicines. It analyzes legislative, regulatory, and code-based compliance control mechanisms and highlights significant developments, including the 2006 and 2012 revisions of the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) Code of Practice.Developments in international controls, largely built upon long-established rules relating to the quality of advertising material, have contributed to clarifying the scope of acceptable company interactions with healthcare professionals. This article aims to provide policy makers, particularly in developing countries, with an overview of the evolution of mechanisms governing the communication practices, such as the distribution of promotional or scientific material and interactions with healthcare stakeholders, relating to prescription-only medicines.

  12. Histoplasmosis infections worldwide: thinking outside of the Ohio River valley.

    Science.gov (United States)

    Bahr, Nathan C; Antinori, Spinello; Wheat, L Joseph; Sarosi, George A

    2015-06-01

    In the United States, histoplasmosis is generally thought to occur mainly in the Ohio and Mississippi River Valleys, and the classic map of histoplasmosis distribution reflecting this is second nature to many U.S. physicians. With the advent of the HIV pandemic reports of patients with progressive disseminated histoplasmosis and AIDS came from regions of known endemicity, as well as from regions not thought to be endemic for histoplasmosis throughout the world. In addition, our expanding armamentarium of immunosuppressive medications and biologics has increased the diagnosis of histoplasmosis worldwide. While our knowledge of areas in which histoplasmosis is endemic has improved, it is still incomplete. Our contention is that physicians should consider histoplasmosis with the right constellations of symptoms in any febrile patient with immune suppression, regardless of geographic location or travel history.

  13. Fighting the Epidemic of Nuclear Plant Leaks.

    Science.gov (United States)

    Udell, Richard A.

    1983-01-01

    The current epidemic of steam generator tube leaks alone should put to rest the rosy future once envisioned for nuclear power. It is impossible to regulate quality into a nuclear plant; it must be built and designed that way. The economic impact of the leaks is discussed. (RM)

  14. Can epidemics be non-communicable?

    DEFF Research Database (Denmark)

    Seeberg, Jens; Meinert, Lotte

    2015-01-01

    This article argues that the concept of communicability that is central to the distinction between communicable diseases (CDs) and noncommunicable diseases (NCDs) is poorly conceptualized. The epidemic spread of NCDs such as diabetes, depression, and eating disorders demonstrates that they are co...

  15. Respiratory Protection against Pandemic and Epidemic Diseases.

    Science.gov (United States)

    Rubino, Ilaria; Choi, Hyo-Jick

    2017-10-01

    Respiratory protection against airborne pathogens is crucial for pandemic/epidemic preparedness in the context of personal protection, healthcare systems, and governance. We expect that the development of technologies that overcome the existing challenges in current respiratory protective devices will lead to a timely and effective response to the next outbreak. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The epidemic of Athens, 430 - 426 BC

    African Journals Online (AJOL)

    1998-01-01

    Jan 1, 1998 ... It began with violent sensations of heat in the head, and redness and ... sufferer with a violence greater than human nature can bear, in the following point ... dwelling with men, gave a better opportunity of observing the effect on animals. Thucydides gives further information relevant to the epidemic:,,15. 1.

  17. A Simple Model for a SARS Epidemic

    Science.gov (United States)

    Ang, Keng Cheng

    2004-01-01

    In this paper, we examine the use of an ordinary differential equation in modelling the SARS outbreak in Singapore. The model provides an excellent example of using mathematics in a real life situation. The mathematical concepts involved are accessible to students with A level Mathematics backgrounds. Data for the SARS epidemic in Singapore are…

  18. Epidemic Models for SARS and Measles

    Science.gov (United States)

    Rozema, Edward

    2007-01-01

    Recent events have led to an increased interest in emerging infectious diseases. This article applies various deterministic models to the SARS epidemic of 2003 and a measles outbreak in the Netherlands in 1999-2000. We take a historical approach beginning with the well-known logistic curve and a lesser-known extension popularized by Pearl and Reed…

  19. School Violence, the Media's Phanton Epidemic.

    Science.gov (United States)

    Best, Joel

    2002-01-01

    Argues that public perceptions of an epidemic of school violence are media-induced; asserts that violence in schools declined during the 1990s; supports assertion with evidence from the National School Safety Center; states the estimates of bullying in school are exaggerated. (PKP)

  20. Cholera Epidemic Control | Zachariah | Malawi Medical Journal

    African Journals Online (AJOL)

    Journal Home > Vol 13, No 1 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Cholera Epidemic Control. R Zachariah. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals ...

  1. Epidemic and power in imperial Recife

    Directory of Open Access Journals (Sweden)

    Rosilene Gomes Farias

    2016-06-01

    Full Text Available In 1856, during the cholera epidemic that hit Recife, actions were implemented to prevent the disease, which presupposed the social control of the poorest sections of the population. The article discusses how these actions demonstrate the power relations involving public and medical authorities in Recife of the Nineteenth Century.

  2. A Simulation Optimization Approach to Epidemic Forecasting.

    Science.gov (United States)

    Nsoesie, Elaine O; Beckman, Richard J; Shashaani, Sara; Nagaraj, Kalyani S; Marathe, Madhav V

    2013-01-01

    Reliable forecasts of influenza can aid in the control of both seasonal and pandemic outbreaks. We introduce a simulation optimization (SIMOP) approach for forecasting the influenza epidemic curve. This study represents the final step of a project aimed at using a combination of simulation, classification, statistical and optimization techniques to forecast the epidemic curve and infer underlying model parameters during an influenza outbreak. The SIMOP procedure combines an individual-based model and the Nelder-Mead simplex optimization method. The method is used to forecast epidemics simulated over synthetic social networks representing Montgomery County in Virginia, Miami, Seattle and surrounding metropolitan regions. The results are presented for the first four weeks. Depending on the synthetic network, the peak time could be predicted within a 95% CI as early as seven weeks before the actual peak. The peak infected and total infected were also accurately forecasted for Montgomery County in Virginia within the forecasting period. Forecasting of the epidemic curve for both seasonal and pandemic influenza outbreaks is a complex problem, however this is a preliminary step and the results suggest that more can be achieved in this area.

  3. The Prescription Opioid Pain Medication Overdose Epidemic

    Centers for Disease Control (CDC) Podcasts

    2016-04-19

    Overdose related to prescription opioids has become an epidemic. This podcast discusses the risks of this type of drug sometimes used to treat pain, and how to protect yourself. .  Created: 4/19/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/19/2016.

  4. Cholera Epidemic Control | Zachariah | Malawi Medical Journal

    African Journals Online (AJOL)

    Malawi Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Cholera Epidemic Control. R Zachariah. Full Text: EMAIL FREE ...

  5. Phylogenetics of the Danish HIV epidemic

    DEFF Research Database (Denmark)

    Audelin, Anne Margrethe; Cowan, Susan A; Obel, Niels

    2013-01-01

    BACKGROUND:: In Denmark 300 new individuals are diagnosed with HIV every year, despite decades of public health campaigns aimed to raise awareness of potential risk behaviour for HIV transmission. It is important to identify the driving forces of the epidemic, to enable more targeted campaigns...

  6. Social epidemics in the aftermath of disasters.

    NARCIS (Netherlands)

    IJzermans, C.J.

    2002-01-01

    Issue/problem: After disasters, terrorist attacks and wars social epidemics of medically unexplained physical symptoms/syndromes (ups) are often seen. In modern times people feel more vulnerable and especially under pressure of those incidents, everyday symptoms are interpreted as disease and

  7. WATER REALITY IN UKRAINE AND WORLDWIDE

    Directory of Open Access Journals (Sweden)

    L. F. Dolina

    2017-10-01

    Full Text Available Purpose. The paper analyzes the state of water management in Ukraine and worldwide, as well as the best practices in this area. Methodology. The study was carried out based on the analysis of literature sources and reporting data on the state of water management in Ukraine, European countries, the USA (2010-2016. Findings. The water state analysis in the regions of Ukraine showed that the quality in most cases is close to or meets the requirements for drinking water. Drinking tap water requires post-treatment in all regions of the country. The main issue for today is the production of the necessary equipment for treatment plants. Unfortunately, not all equipment is produced in Ukraine. The condition of rural water pipelines is of particular concern. Among the tested pipelines 7.3% do not comply with the rules and regulations. At the same time, only 25% of villages in Ukraine are provided with centralized water supply. Originality. The authors presented the results of a comprehensive review of the world's issues on disinfection of drinking and waste water, where various methods are used, partly in combination with each other in Ukraine and the worldwide. The main unresolved issue today is the issue of the residual quantity of drugs in the drinking water. The main environmental threat of the world scale is the presence of medicines in drinking water. The treatment facilities are not suitable for the decomposition or trapping of medicinal products. Nowhere in the world there is protection from these substances. One of the key issues in the solution of drinking water production is seawater desalination. To reduce the cost of desalination of sea water the SWRO-membrane technology is used. Practical value. Water problems are number one problems all over the world and in Ukraine as well. It is necessary to provide for additional financing to solve problems in the preparation and purification of waters, not with whatever funds remain, taking into

  8. The Zika Virus Epidemic in Brazil: From Discovery to Future Implications

    Directory of Open Access Journals (Sweden)

    Rachel Lowe

    2018-01-01

    Full Text Available The first confirmed case of Zika virus infection in the Americas was reported in Northeast Brazil in May 2015, although phylogenetic studies indicate virus introduction as early as 2013. Zika rapidly spread across Brazil and to more than 50 other countries and territories on the American continent. The Aedes aegypti mosquito is thought to be the principal vector responsible for the widespread transmission of the virus. However, sexual transmission has also been reported. The explosively emerging epidemic has had diverse impacts on population health, coinciding with cases of Guillain–Barré Syndrome and an unexpected epidemic of newborns with microcephaly and other neurological impairments. This led to Brazil declaring a national public health emergency in November 2015, followed by a similar decision by the World Health Organization three months later. While dengue virus serotypes took several decades to spread across Brazil, the Zika virus epidemic diffused within months, extending beyond the area of permanent dengue transmission, which is bound by a climatic barrier in the south and low population density areas in the north. This rapid spread was probably due to a combination of factors, including a massive susceptible population, climatic conditions conducive for the mosquito vector, alternative non-vector transmission, and a highly mobile population. The epidemic has since subsided, but many unanswered questions remain. In this article, we provide an overview of the discovery of Zika virus in Brazil, including its emergence and spread, epidemiological surveillance, vector and non-vector transmission routes, clinical complications, and socio-economic impacts. We discuss gaps in the knowledge and the challenges ahead to anticipate, prevent, and control emerging and re-emerging epidemics of arboviruses in Brazil and worldwide.

  9. Worldwide Engagement for Sustainable Energy Strategies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-01

    Almost 40 years after the Agency’s founding, the IEA responsibility for ensuring access to global oil supplies is still a core mandate. Yet over the course of its history, the IEA’s responsibilities have expanded along with both the international energy economy and conceptions of energy security itself. Our mission to promote secure and sustainable energy provision spans the energy mix. At the same time, a changing global energy map means that the industrialised nations of the world no longer dominate energy consumption. The IEA must work in close co-operation with partner countries and organisations worldwide to achieve its three core objectives: energy security, economic prosperity, and environmental sustainability. Working toward international commitments to reduce greenhouse gas emissions that cause global climate change; facilitating energy technology exchange, innovation and deployment; improving modern energy access to the billions of people who are without it; bolstering both cleanliness and security through energy efficiency; and promoting flexible and functioning energy markets – these efforts complement our traditional core responsibilities of mitigating the effects of supply disruptions and improving statistical transparency.

  10. Worldwide phylogenetic relationship of avian poxviruses

    Science.gov (United States)

    Gyuranecz, Miklós; Foster, Jeffrey T.; Dán, Ádám; Ip, Hon S.; Egstad, Kristina F.; Parker, Patricia G.; Higashiguchi, Jenni M.; Skinner, Michael A.; Höfle, Ursula; Kreizinger, Zsuzsa; Dorrestein, Gerry M.; Solt, Szabolcs; Sós, Endre; Kim, Young Jun; Uhart, Marcela; Pereda, Ariel; González-Hein, Gisela; Hidalgo, Hector; Blanco, Juan-Manuel; Erdélyi, Károly

    2013-01-01

    Poxvirus infections have been found in 230 species of wild and domestic birds worldwide in both terrestrial and marine environments. This ubiquity raises the question of how infection has been transmitted and globally dispersed. We present a comprehensive global phylogeny of 111 novel poxvirus isolates in addition to all available sequences from GenBank. Phylogenetic analysis of Avipoxvirus genus has traditionally relied on one gene region (4b core protein). In this study we have expanded the analyses to include a second locus (DNA polymerase gene), allowing for a more robust phylogenetic framework, finer genetic resolution within specific groups and the detection of potential recombination. Our phylogenetic results reveal several major features of avipoxvirus evolution and ecology and propose an updated avipoxvirus taxonomy, including three novel subclades. The characterization of poxviruses from 57 species of birds in this study extends the current knowledge of their host range and provides the first evidence of the phylogenetic effect of genetic recombination of avipoxviruses. The repeated occurrence of avian family or order-specific grouping within certain clades (e.g. starling poxvirus, falcon poxvirus, raptor poxvirus, etc.) indicates a marked role of host adaptation, while the sharing of poxvirus species within prey-predator systems emphasizes the capacity for cross-species infection and limited host adaptation. Our study provides a broad and comprehensive phylogenetic analysis of the Avipoxvirus genus, an ecologically and environmentally important viral group, to formulate a genome sequencing strategy that will clarify avipoxvirus taxonomy.

  11. Comparing alcohol affordability in 65 cities worldwide.

    Science.gov (United States)

    Kan, Ming-Yue; Lau, Maggie

    2013-01-01

    To develop a measure of alcohol affordability (AA) and compare the AA of 65 cities worldwide. In this paper, AA is defined as the proportion of median daily income needed to buy a certain quantity of certain alcoholic beverages. The income data and the price of alcoholic beverages were drawn from the Union Bank of Switzerland survey and the Economist Intelligence Unit respectively. A large majority of cities (87.7%, n = 57) had a high level of AA. The top 20 ranking was occupied by European and American cities with Tokyo in the Western Pacific region being the exception. All cities belonging to high-income countries had high levels of AA. However, two cities with low-level AA came from low-middle-income countries instead of low-income countries. The findings have shown that alcohol consumption is highly affordable in many cities. If price policy is being considered as policy instrument of alcohol control, it is in urgent need of price adjustments. More specifically, the new emerging economies play a significant role in the world alcohol control movement because of their bright economic performance with huge population size. Further studies on AA, especially periodical monitoring and its impacts on alcohol consumption and alcohol related health problems, should be conducted so as to facilitate the formulation and evaluation price measure of alcohol control. © 2012 Australasian Professional Society on Alcohol and other Drugs.

  12. Worldwide trends in diabetes since 1980

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Andersen, Lars Bo; Bugge, Anna

    2016-01-01

    5.0% (2.9-7.9) to 7.9% (6.4-9.7) in women. The number of adults with diabetes in the world increased from 108 million in 1980 to 422 million in 2014 (28.5% due to the rise in prevalence, 39.7% due to population growth and ageing, and 31.8% due to interaction of these two factors). Age...... in prevalence, together with population growth and ageing, are affecting the number of adults with diabetes. METHODS: We pooled data from population-based studies that had collected data on diabetes through measurement of its biomarkers. We used a Bayesian hierarchical model to estimate trends in diabetes...... with population growth and ageing, this rise has led to a near quadrupling of the number of adults with diabetes worldwide. The burden of diabetes, both in terms of prevalence and number of adults affected, has increased faster in low-income and middle-income countries than in high-income countries. FUNDING...

  13. A Worldwide Glacier Information System to go

    Science.gov (United States)

    Mölg, N.; Steinmann, M.; Zemp, M.

    2016-12-01

    In the forefront of the Paris Climate Conference COP21 in December 2015, the WGMS and UNESCO jointly launched a glacier application for mobile devices. This new information system aims at bringing scientifically sound facts and figures on worldwide glacier changes to decision makers at governmental and intergovernmental levels as well as reaching out to the interested public. The wgms Glacier App provides a map interface based on satellite images that display all the observed glaciers in the user's proximity. Basic information is provided for each glacier, including photographs and general information on size and elevation. Graphs with observation data illustrate the glacier's development, along with information on latest principal investigators and their sponsoring agencies as well as detailed explanations of the measurement types. A text search allows the user to filter the glacier by name, country, region, measurement type and the current "health" status, i.e. if the glacier has gained or lost ice over the past decade. A compass shows the closest observed glaciers in all directions from the user's current position. Finally, the card game allows the user to compete against the computer on the best monitored glaciers in the world. Our poster provides a visual entrance point to the wgms Glacier App and, hence, provides access to fluctuation series of more than 3'700 glaciers around the world.

  14. The Worldwide Hospice Palliative Care Alliance.

    Science.gov (United States)

    Connor, Stephen R; Gwyther, Elizabeth

    2018-02-01

    The Worldwide Hospice Palliative Care Alliance (WHPCA) is an international non-governmental organization registered as a charity in England and Wales that was established in 2008 following a series of international gatherings that highlighted the important need for palliative care to be included in global policy and health planning. The vision of the WHPCA is a world with universal access to hospice and palliative care. Its mission is to foster, promote and influence the delivery of affordable, quality palliative care. This article describes the evolution of the WHPCA and what it has been able to accomplish in the eight years since its formation. These accomplishments include effective advocacy with United Nations bodies, acceptance as a non-governmental organization in official relations with the World Health Organization and the UN Economic and Social Council, publication of many position papers on critical aspects of palliative care, publication of the Global Atlas of Palliative Care at the End of Life, development of toolkits for palliative care development, publication of the international edition of ehospice, and management of World Hospice and Palliative Care Day each year. Some of the many challenges to the growth and development of palliative care globally are described along with future plans. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  15. Bitcoin – the World-Wide Currency

    Directory of Open Access Journals (Sweden)

    Shuba Olena А.

    2017-11-01

    Full Text Available The article is aimed at researching bitcoin, the digital currency. It has been found that Bitcoin is a cryptocurrency, that is, the virtual money, which has no material equivalent. The history of creation and development of cryptocurrency was reviewed. There is a reduction in volatility, which guarantees the security of currency, as well as the increase in currency volume and the inability to estimate the profitability of bitcoins. The dynamics of the value of digital currency in US dollars over recent years has been analyzed. Improvement of attitude of many countries to the considered cryptocurrency, in particular the USA, Germany, Spain, Canada, Australia, Israel and Scandinavian countries has been identified. The reasons of Ukraine’s interest in Bitcoin have been considered. Possibilities of creation of cryptocurrency on the territory of Ukraine have been analyzed, i.e. cost of electricity for mining, the legal status of mining firms, and the attitude of the National Bank of Ukraine to the digital currency. It has been concluded that the recognition of Bitcoin by the world countries in the future will allow it to be granted the status of world-wide currency.

  16. Reference worldwide model for antineutrinos from reactors

    Science.gov (United States)

    Baldoncini, Marica; Callegari, Ivan; Fiorentini, Giovanni; Mantovani, Fabio; Ricci, Barbara; Strati, Virginia; Xhixha, Gerti

    2015-03-01

    Antineutrinos produced at nuclear reactors constitute a severe source of background for the detection of geoneutrinos, which bring to the Earth's surface information about natural radioactivity in the whole planet. In this framework, we provide a reference worldwide model for antineutrinos from reactors, in view of reactors operational records yearly published by the International Atomic Energy Agency. We evaluate the expected signal from commercial reactors for ongoing (KamLAND and Borexino), planned (SNO +), and proposed (Juno, RENO-50, LENA, and Hanohano) experimental sites. Uncertainties related to reactor antineutrino production, propagation, and detection processes are estimated using a Monte Carlo-based approach, which provides an overall site-dependent uncertainty on the signal in the geoneutrino energy window on the order of 3%. We also implement the off-equilibrium correction to the reference reactor spectra associated with the long-lived isotopes, and we estimate a 2.4% increase of the unoscillated event rate in the geoneutrino energy window due to the storage of spent nuclear fuels in the cooling pools. We predict that the research reactors contribute to less than 0.2% to the commercial reactor signal in the investigated 14 sites. We perform a multitemporal analysis of the expected reactor signal over a time lapse of ten years using reactor operational records collected in a comprehensive database published at www.fe.infn.it/antineutrino.

  17. Evolution of Toilets Worldwide through the Millennia

    Directory of Open Access Journals (Sweden)

    Georgios P. Antoniou

    2016-08-01

    Full Text Available Throughout history, various civilizations developed methodologies for the collection and disposal of human waste. The methodologies throughout the centuries have been characterized by technological peaks on the one hand, and by the disappearance of the technologies and their reappearance on the other. The purpose of this article is to trace the development of sewage collection and transport with an emphasis on toilets in ancient civilizations. Evolution of the major achievements in the scientific fields of sanitation with emphasis on the lavatory (or toilets technologies through the centuries up to the present are presented. Valuable insights into ancient wastewater technologies and management with their apparent characteristics of durability, adaptability to the environment, and sustainability are provided. Gradual steps improved the engineering results until the establishment of the contemporary toilet system, which provides a combined solution for flushing, odor control, and the sanitation of sewerage. Even though the lack of proper toilet facilities for a great percentage of the present day global population is an embarrassing fact, the worldwide efforts through millennia for the acquisition of a well-engineered toilet were connected to the cultural level of each period.

  18. Welcome to the World-Wide Web.

    Science.gov (United States)

    Davis, Philip

    1995-01-01

    World Wide Web (WWW) is a multimedia, globally distributed, client/server information system based on hypertext. WWW browser software (Mosaic, Cello, and Samba) allows users to navigate hypertext documents via the Internet. Libraries are taking advantage of the fact that hypertext linked documents can be easily and inexpensively shared. (JMV)

  19. Parameter Scaling for Epidemic Size in a Spatial Epidemic Model with Mobile Individuals.

    Directory of Open Access Journals (Sweden)

    Chiyori T Urabe

    Full Text Available In recent years, serious infectious diseases tend to transcend national borders and widely spread in a global scale. The incidence and prevalence of epidemics are highly influenced not only by pathogen-dependent disease characteristics such as the force of infection, the latent period, and the infectious period, but also by human mobility and contact patterns. However, the effect of heterogeneous mobility of individuals on epidemic outcomes is not fully understood. Here, we aim to elucidate how spatial mobility of individuals contributes to the final epidemic size in a spatial susceptible-exposed-infectious-recovered (SEIR model with mobile individuals in a square lattice. After illustrating the interplay between the mobility parameters and the other parameters on the spatial epidemic spreading, we propose an index as a function of system parameters, which largely governs the final epidemic size. The main contribution of this study is to show that the proposed index is useful for estimating how parameter scaling affects the final epidemic size. To demonstrate the effectiveness of the proposed index, we show that there is a positive correlation between the proposed index computed with the real data of human airline travels and the actual number of positive incident cases of influenza B in the entire world, implying that the growing incidence of influenza B is attributed to increased human mobility.

  20. Worldwide seismicity in view of non-extensive statistical physics

    Science.gov (United States)

    Chochlaki, Kaliopi; Vallianatos, Filippos; Michas, George

    2014-05-01

    In the present work we study the distribution of worldwide shallow seismic events occurred from 1981 to 2011 extracted from the CMT catalog, with magnitude equal or greater than Mw 5.0. Our analysis based on the subdivision of the Earth surface into seismic zones that are homogeneous with regards to seismic activity and orientation of the predominant stress field. To this direction we use the Flinn-Engdahl regionalization (Flinn and Engdahl, 1965), which consists of 50 seismic zones as modified by Lombardi and Marzocchi (2007), where grouped the 50 FE zones into larger tectonically homogeneous ones, utilizing the cumulative moment tensor method. As a result Lombardi and Marzocchi (2007), limit the initial 50 regions to 39 ones, in which we apply the non- extensive statistical physics approach. The non-extensive statistical physics seems to be the most adequate and promising methodological tool for analyzing complex systems, such as the Earth's interior. In this frame, we introduce the q-exponential formulation as the expression of probability distribution function that maximizes the Sq entropy as defined by Tsallis, (1988). In the present work we analyze the interevent time distribution between successive earthquakes by a q-exponential function in each of the seismic zones defined by Lombardi and Marzocchi (2007).confirming the importance of long-range interactions and the existence of a power-law approximation in the distribution of the interevent times. Our findings supports the ideas of universality within the Tsallis approach to describe Earth's seismicity and present strong evidence on temporal clustering of seismic activity in each of the tectonic zones analyzed. Our analysis as applied in worldwide seismicity with magnitude equal or greater than Mw 5.5 and 6.) is presented and the dependence of our result on the cut-off magnitude is discussed. This research has been funded by the European Union (European Social Fund) and Greek national resources under the

  1. Transferring the Malaria Epidemic Prediction Model to Users in East ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Download PDF. Journal articles. Development and validation of climate and ecosystem-based early malaria epidemic prediction models in East Africa. Download PDF. Journal articles. Identification of malaria transmission and epidemic hotspots in the western Kenya highlands : its application to malaria epidemic prediction.

  2. Nonalcoholic fatty liver disease: A comprehensive review of a growing epidemic

    Science.gov (United States)

    Hassan, Kareem; Bhalla, Varun; Ezz El Regal, Mohammed; A-Kader, H Hesham

    2014-01-01

    Nonalcoholic fatty liver disease (NAFLD) is quickly becoming one of the most prominent causes of liver disease worldwide. The increasing incidence of NAFLD is tied to the obesity epidemic and the subsequent metabolic derangements brought along with it. Current efforts to elucidate the mechanism and causes of the disease have answered some questions, but much remains unknown about NAFLD. The aim of this article is to discuss the current knowledge regarding the pathogenesis of the disease, as well as the current and future diagnostic, preventative, and therapeutic options available to clinicians for the management of NAFLD. PMID:25232245

  3. On the relative role of different age groups in influenza epidemics.

    Science.gov (United States)

    Worby, Colin J; Chaves, Sandra S; Wallinga, Jacco; Lipsitch, Marc; Finelli, Lyn; Goldstein, Edward

    2015-12-01

    The identification of key "driver" groups in influenza epidemics is of much interest for the implementation of effective public health response strategies, including vaccination programs. However, the relative importance of different age groups in propagating epidemics is uncertain. During a communicable disease outbreak, some groups may be disproportionately represented during the outbreak's ascent due to increased susceptibility and/or contact rates. Such groups or subpopulations can be identified by considering the proportion of cases within the subpopulation occurring before (Bp) and after the epidemic peak (Ap) to calculate the subpopulation's relative risk, RR=Bp/Ap. We estimated RR for several subpopulations (age groups) using data on laboratory-confirmed US influenza hospitalizations during epidemics between 2009-2014. Additionally, we simulated various influenza outbreaks in an age-stratified population, relating the RR to the impact of vaccination in each subpopulation on the epidemic's initial effective reproductive number R_e(0). We found that children aged 5-17 had the highest estimates of RR during the five largest influenza A outbreaks, though the relative magnitude of RR in this age group compared to other age groups varied, being highest for the 2009 A/H1N1 pandemic. For the 2010-2011 and 2012-2013 influenza B epidemics, adults aged 18-49, and 0-4 year-olds had the highest estimates of RR respectively. For 83% of simulated epidemics, the group with the highest RR was also the group for which initial distribution of a given quantity of vaccine would result in the largest reduction of R_e(0). In the largest 40% of simulated outbreaks, the group with the highest RR and the largest vaccination impact was children 5-17. While the relative importance of different age groups in propagating influenza outbreaks varies, children aged 5-17 play the leading role during the largest influenza A epidemics. Extra vaccination efforts for this group may contribute

  4. Worldwide Differences in Regulations of Clozapine Use.

    Science.gov (United States)

    Nielsen, Jimmi; Young, Corina; Ifteni, Petru; Kishimoto, Taishiro; Xiang, Yu-Tao; Schulte, Peter F J; Correll, Christoph U; Taylor, David

    2016-02-01

    Clozapine remains the drug of choice for treatment-resistant schizophrenia. As a consequence of its long history and complex pharmacology, we suspected wide variation in the regulations of clozapine use across different countries. The summaries of product characteristics (SPCs) from clozapine manufacturers, as well as local and national guidelines in the following selected countries, were reviewed: China, Denmark, Ireland, Japan, The Netherlands, New Zealand, Romania, the UK and the US. Clozapine is available as tablets in all countries, as an oral suspension in all included countries, with the exception of Japan and Romania, as orally disintegrating tablets in the US and China, and as an injectable in The Netherlands. General practitioner prescribing is only available in The Netherlands, New Zealand, the UK and the US, although with some restrictions in some of the countries. In Ireland and China, clozapine is only dispensed through hospital pharmacies. Hematological monitoring is mandatory in all countries but varies substantially in frequency, e.g. in Denmark hematologic monitoring is mandatory weekly for 18 weeks, followed by monthly monitoring, compared with Japan where blood work is required weekly for 26 weeks, followed by biweekly hematologic monitoring thereafter. In most included countries, with the exception of Denmark, Romania and The Netherlands, the manufacturer provides a mandatory hematological monitoring database, and dispensing of clozapine is not permissible without acceptable white blood count and absolute neutrophil count results. Local guidelines in New Zealand recommend echocardiography and routine troponin during the initial phases of treatment with clozapine. Regulations of clozapine vary widely with regard to rules of prescribing and monitoring. A worldwide update and harmonization of these regulations is recommended.

  5. Conservation Kickstart- Catalyzing Conservation Initiatives Worldwide

    Science.gov (United States)

    Treinish, G.

    2014-12-01

    Adventurers and Scientists for Conservation (ASC) is a nonprofit organization that collects environmental data to catalyze conservation initiatives worldwide. Adventure athletes have the skills and motivation to reach the most remote corners of the world. ASC utilizes those skills to provide the scientific community with data while providing the outdoor community with purpose beyond the personal high of reaching a summit or rowing across an ocean. We carefully select projects, choosing partnerships that will maximize the impact of ASC volunteers. Each project must have a clear path to a tangible conservation outcome and demonstrate a clear need for our brand of volunteers. We partner with government agencies, universities, and independant reseachers to kickstart data collection efforts around the world. Last year, through a partnership with the Olympic National Forest, 20 volunteers from the Seattle area set up and monitored camera traps in an effort to survey for costal Pacific marten. Our work led to the species' listing as "critically imperiled" with NatureServe. A partnership with the inaugural Great Pacific Race, engaging trans-Pacific rowing teams, searched for microplastics in the Pacific Ocean as part of our ongoing microplastics campaign. In a multi-year partnership with the American Prairie Reserve (APR), ASC volunteer crews live and work on the Reserve collecting wildlife data year round. The data we obtain directly informs the Reserve's wildlife management decisions. On this project, our crews have safely and effectively navigated temperature extremes from -30 degrees to 100+ degrees while traveling in a remote location. We are currently scouting projects in the Okavango Delta of Botswana and the rainforest of Suriname where we will be able to cover large amounts of area in a short periord of time. ASC is at the crossroads of the adventure and coservation science communities. Our approach of answering specific questions by using highly skilled and

  6. USE OF MALE METHODS OF CONTRACEPTION WORLDWIDE.

    Science.gov (United States)

    Ross, John; Hardee, Karen

    2017-09-01

    This article analyses male contraceptive use, both globally and for developing countries. Shares of all contraceptive use due to males are examined, in the context of female use and all use. Patterns according to wealth quintiles are analysed, as well as time trends and geographic variations. Data are drawn primarily from compilations by the UN Population Division and from the Demographic and Health Series and subjected to relatively simple statistical methods including correlation/regression applications. Contraceptive methods that men use directly, or that require their co-operation to use, including condoms, withdrawal, rhythm and male sterilization, account for one-quarter of all contraceptive use worldwide. This represents 13% of married/in-union women. Both the share and the prevalence of male methods vary widely by geography and by the four methods, as well as by quintile wealth groups. With greater wealth there is an unbroken rise for total use; among the male methods, the shares of condom use and rhythm rise by wealth quintiles, while the share of withdrawal drops. The share for male sterilization is highest in the lowest and highest wealth quintiles and dips for the middle quintiles. The overall time trend since the 1980s has been steady at one-quarter of all use involving men; moreover, the share is about the same at all levels of total use. The female-only methods continue to dominate: female sterilization, IUD, pill, injectable and implant, again with great diversity geographically. In surveys men report less total use but more condom use, while females report more injectable use. For the future the male share of one-quarter of use seems secure, with little prospect of an increase unless concerted programmatic efforts are made to expand access to male methods and promote their use as part of a broadened contraceptive method mix.

  7. Population genetic analysis of Bartonella bacilliformis isolates from areas of peru where Carrion's disease is endemic and epidemic.

    Science.gov (United States)

    Hambuch, Tina M; Handley, Scott A; Ellis, Barbara; Chamberlin, Judith; Romero, Sofia; Regnery, Russell

    2004-08-01

    Carrion's disease is caused by infection with the alpha-proteobacterium Bartonella bacilliformis. Distribution of the disease is considered coincident with the distribution of its known vector, the sand fly Lutzomyia verrucarum. Recent epidemics of B. bacilliformis infections associated with atypical symptomatology in nonendemic regions have raised questions regarding the historic and present distribution of this bacterium and the scope of disease that infection causes. Phylogenetic relationships and genomic diversity of 18 B. bacilliformis isolates (10 isolates from a region where Carrion's disease is epidemic, Cuzco, Peru, and 8 isolates from a region where Carrion's disease is endemic, Caraz, Peru) were assessed using genomic data generated by infrequent restriction site PCR and gene sequence analysis of the flagellin gltA and ialB genes. A population genetic analysis of the genomic diversity suggests that what was once considered an epidemic region of Peru did not result from the recent introduction of B. bacilliformis.

  8. Sequential detection of influenza epidemics by the Kolmogorov-Smirnov test

    Directory of Open Access Journals (Sweden)

    Closas Pau

    2012-10-01

    Full Text Available Abstract Background Influenza is a well known and common human respiratory infection, causing significant morbidity and mortality every year. Despite Influenza variability, fast and reliable outbreak detection is required for health resource planning. Clinical health records, as published by the Diagnosticat database in Catalonia, host useful data for probabilistic detection of influenza outbreaks. Methods This paper proposes a statistical method to detect influenza epidemic activity. Non-epidemic incidence rates are modeled against the exponential distribution, and the maximum likelihood estimate for the decaying factor λ is calculated. The sequential detection algorithm updates the parameter as new data becomes available. Binary epidemic detection of weekly incidence rates is assessed by Kolmogorov-Smirnov test on the absolute difference between the empirical and the cumulative density function of the estimated exponential distribution with significance level 0 ≤ α ≤ 1. Results The main advantage with respect to other approaches is the adoption of a statistically meaningful test, which provides an indicator of epidemic activity with an associated probability. The detection algorithm was initiated with parameter λ0 = 3.8617 estimated from the training sequence (corresponding to non-epidemic incidence rates of the 2008-2009 influenza season and sequentially updated. Kolmogorov-Smirnov test detected the following weeks as epidemic for each influenza season: 50−10 (2008-2009 season, 38−50 (2009-2010 season, weeks 50−9 (2010-2011 season and weeks 3 to 12 for the current 2011-2012 season. Conclusions Real medical data was used to assess the validity of the approach, as well as to construct a realistic statistical model of weekly influenza incidence rates in non-epidemic periods. For the tested data, the results confirmed the ability of the algorithm to detect the start and the end of epidemic periods. In general, the proposed test could

  9. Toward a generalized theory of epidemic awareness in social networks

    Science.gov (United States)

    Wu, Qingchu; Zhu, Wenfang

    We discuss the dynamics of a susceptible-infected-susceptible (SIS) model with local awareness in networks. Individual awareness to the infectious disease is characterized by a general function of epidemic information in its neighborhood. We build a high-accuracy approximate equation governing the spreading dynamics and derive an approximate epidemic threshold above which the epidemic spreads over the whole network. Our results extend the previous work and show that the epidemic threshold is dependent on the awareness function in terms of one infectious neighbor. Interestingly, when a pow-law awareness function is chosen, the epidemic threshold can emerge in infinite networks.

  10. Obesity and Kidney Disease: Hidden Consequences of the Epidemic.

    Science.gov (United States)

    Kovesdy, Csaba P; Furth, Susan; Zoccali, Carmine

    2017-03-01

    Obesity has become a worldwide epidemic, and its prevalence has been projected to grow by 40% in the next decade. This increasing prevalence has implications for the risk of diabetes mellitus, cardiovascular disease, and also for chronic kidney disease. A high body mass index is one of the strongest risk factors for new-onset chronic kidney disease. In individuals affected by obesity, a compensatory hyperfiltration occurs to meet the heightened metabolic demands of the increased body weight. The increase in intraglomerular pressure can damage the kidneys and raise the risk of developing chronic kidney disease in the long-term. The incidence of obesity-related glomerulopathy has increased 10-fold in recent years. Obesity has also been shown to be a risk factor for nephrolithiasis, and for a number of malignancies including kidney cancer. This year, the World Kidney Day promotes education on the harmful consequences of obesity and its association with kidney disease, advocating healthy lifestyle and health policy measures that make preventive behaviors an affordable option.

  11. Canine parvovirus: the worldwide occurrence of antigenic variants.

    Science.gov (United States)

    Miranda, Carla; Thompson, Gertrude

    2016-09-01

    The most important enteric virus infecting canids is canine parvovirus type 2 (CPV-2). CPV is the aetiologic agent of a contagious disease, mainly characterized by clinical gastroenteritis signs in younger dogs. CPV-2 emerged as a new virus in the late 1970s, which could infect domestic dogs, and became distributed in the global dog population within 2 years. A few years later, the virus's original type was replaced by a new genetic and antigenic variant, called CPV-2a. Around 1984 and 2000, virus variants with the single change to Asp or Glu in the VP2 residue 426 were detected (sometimes termed CPV-2b and -2c). The genetic and antigenic changes in the variants have also been correlated with changes in their host range; in particular, in the ability to replicate in cats and also host range differences in canine and other tissue culture cells. CPV-2 variants have been circulating among wild carnivores and have been well-documented in several countries around the world. Here, we have reviewed and summarized the current information about the worldwide distribution and evolution of CPV-2 variants since they emerged, as well as the host ranges they are associated with.

  12. Spread of epidemic disease on networks

    Science.gov (United States)

    Newman, M. E.

    2002-07-01

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

  13. Extinction times of epidemic outbreaks in networks.

    Directory of Open Access Journals (Sweden)

    Petter Holme

    Full Text Available In the Susceptible-Infectious-Recovered (SIR model of disease spreading, the time to extinction of the epidemics happens at an intermediate value of the per-contact transmission probability. Too contagious infections burn out fast in the population. Infections that are not contagious enough die out before they spread to a large fraction of people. We characterize how the maximal extinction time in SIR simulations on networks depend on the network structure. For example we find that the average distances in isolated components, weighted by the component size, is a good predictor of the maximal time to extinction. Furthermore, the transmission probability giving the longest outbreaks is larger than, but otherwise seemingly independent of, the epidemic threshold.

  14. [The depression epidemic does not exist].

    Science.gov (United States)

    van der Feltz-Cornelis, Christina M

    2009-01-01

    There has been much discussion in the media about the question of the existence of a depression epidemic. This leads on to the questions of whether the social and economic approaches are adequate, and what the alternatives are. The concept of the disease 'depression' can be defined using a medical model, or from a patient's or a societal perspective. From a medical perspective, indeed a depression epidemic has ensued from the increased prosperity and the associated decompression of the mortality rate. Society responded with preventative measures and policies aimed at improving functioning in the workplace. However, patients with a major depressive disorder (MDD) who are eligible for treatment are often not motivated to take it up, or are undertreated. Research is necessary in order to explore what patients think about the identification and treatment of depression. The confusion regarding the concept of depression found in the media, needs to be cleared.

  15. New Approaches to the Methamphetamine Epidemic

    OpenAIRE

    Zusman, Mara B.

    2004-01-01

    Methamphetamine abuse has become an epidemic in the United States. As methamphetamine becomes increasingly available, more and more people are trying – and becoming addicted to – this potent drug. But although methamphetamine is made using over-the-counter (OTC) drugs containing pseudoephedrine, shifting OTC drugs containing pseudoephedrine to prescription status is not the solution to the methamphetamine crisis. Rather, society must adopt a comprehensive...

  16. Travelling waves in the lattice epidemic model

    Directory of Open Access Journals (Sweden)

    Zhixian Yu

    2010-07-01

    Full Text Available In this article, we establish the existence and nonexistence of travelling waves for a lattice non-monotone integral equation which is an epidemic model. Moreover, the wave is either convergent to the positive equilibrium or oscillating on the positive equilibrium at positive infinity, and has the exponential asymptotic behavior at negative infinity. For the non-monotone case, the asymptotic speed of propagation also coincides with the minimal wave speed.

  17. A computer simulation of employee vaccination to mitigate an influenza epidemic.

    Science.gov (United States)

    Lee, Bruce Y; Brown, Shawn T; Cooley, Philip C; Zimmerman, Richard K; Wheaton, William D; Zimmer, Shanta M; Grefenstette, John J; Assi, Tina-Marie; Furphy, Timothy J; Wagener, Diane K; Burke, Donald S

    2010-03-01

    Better understanding the possible effects of vaccinating employees is important and can help policymakers and businesses plan vaccine distribution and administration logistics, especially with the current H1N1 influenza vaccine in short supply. This article aims to determine the effects of varying vaccine coverage, compliance, administration rates, prioritization, and timing among employees during an influenza pandemic. As part of the H1N1 influenza planning efforts of the Models of Infectious Disease Agent Study network, an agent-based computer simulation model was developed for the Washington DC metropolitan region, encompassing five metropolitan statistical areas. Each simulation run involved introducing 100 infectious individuals to initiate a 1.3 reproductive-rate (R(0)) epidemic, consistent with H1N1 parameters to date. Another set of scenarios represented a R(0)=1.6 epidemic. An unmitigated epidemic resulted in substantial productivity losses (a mean of $112.6 million for a serologic 15% attack rate and $193.8 million for a serologic 25% attack rate), even with the relatively low estimated mortality impact of H1N1. Although vaccinating Advisory Committee on Immunization Practices-defined priority groups resulted in the largest savings, vaccinating all remaining workers captured additional savings and, in fact, reduced healthcare workers' and critical infrastructure workers' chances of infection. Moreover, although employee vaccination compliance affected the epidemic, once 20% compliance was achieved, additional increases in compliance provided less incremental benefit. Even though a vast majority of the workplaces in the DC metropolitan region had fewer than 100 employees, focusing on vaccinating only those in larger firms (> or =100 employees) was just as effective in mitigating the epidemic as trying to vaccinate employees in all workplaces. Timely vaccination of at least 20% of the large-company workforce can play an important role in epidemic mitigation

  18. The glue ear 'epidemic': a historical perspective.

    Science.gov (United States)

    Alderson, David

    2011-12-01

    This paper explores the historical context of the dramatic rise in surgery for glue ear in the mid-20th century, and questions the published assertion that this represented a manufactured 'epidemic'. In examining historical sources, the reader's theoretical viewpoint greatly influences their conclusions: the sustained rise in treatment for glue ear may be seen as the advance of science in a golden age or the resistance of insular professionals to reason in the light of new scientific study methods. Current views on the practice of medicine, consumerism, science and standardisation, rationing and the nature of 'truth' all affect the way that we see this period. Technological advances clearly allowed better diagnosis and more effective treatment, but these did not appear to drive an 'epidemic', rather they were developed to meet the pre-existing challenges of otological practice. The proposition that an 'epidemic' was created does not appear to have any solid grounding. Society's perception of what constitutes disease and what needs treatment may have evolved, but the prevalence of other important diseases changed dramatically over this time period, and a real change in the epidemiology of glue ear cannot be dismissed. In defining the case for and against surgical treatment, a solely positivist, quantitative worldview cannot give us a complete picture of benefit and risk to individuals, families and society at large.

  19. Cyanobacteria facilitate parasite epidemics in Daphnia.

    Science.gov (United States)

    Tellenbach, C; Tardent, N; Pomati, F; Keller, B; Hairston, N G; Wolinska, J; Spaak, P

    2016-12-01

    The seasonal dominance of cyanobacteria in the phytoplankton community of lake ecosystems can have severe implications for higher trophic levels. For herbivorous zooplankton such as Daphnia, cyanobacteria have poor nutritional value and some species can produce toxins affecting zooplankton survival and reproduction. Here we present another, hitherto largely unexplored aspect of cyanobacteria, namely that they can increase Daphnia susceptibility to parasites. In a 12-yr monthly time-series analysis of the Daphnia community in Greifensee (Switzerland), we observed that cyanobacteria density correlated significantly with the epidemics of a common gut parasite of Daphnia, Caullerya mesnili, regardless of what cyanobacteria species was present or whether it was colonial or filamentous. The temperature from the previous month also affected the occurrence of Caullerya epidemics, either directly or indirectly by the promotion of cyanobacterial growth. A laboratory experiment confirmed that cyanobacteria increase the susceptibility of Daphnia to Caullerya, and suggested a possible involvement of cyanotoxins or other chemical traits of cyanobacteria in this process. These findings expand our understanding of the consequences of toxic cyanobacterial blooms for lake ecosystems and might be relevant for epidemics experienced by other aquatic species. © 2016 by the Ecological Society of America.

  20. Memory effects on epidemic evolution: The susceptible-infected-recovered epidemic model

    Science.gov (United States)

    Saeedian, M.; Khalighi, M.; Azimi-Tafreshi, N.; Jafari, G. R.; Ausloos, M.

    2017-02-01

    Memory has a great impact on the evolution of every process related to human societies. Among them, the evolution of an epidemic is directly related to the individuals' experiences. Indeed, any real epidemic process is clearly sustained by a non-Markovian dynamics: memory effects play an essential role in the spreading of diseases. Including memory effects in the susceptible-infected-recovered (SIR) epidemic model seems very appropriate for such an investigation. Thus, the memory prone SIR model dynamics is investigated using fractional derivatives. The decay of long-range memory, taken as a power-law function, is directly controlled by the order of the fractional derivatives in the corresponding nonlinear fractional differential evolution equations. Here we assume "fully mixed" approximation and show that the epidemic threshold is shifted to higher values than those for the memoryless system, depending on this memory "length" decay exponent. We also consider the SIR model on structured networks and study the effect of topology on threshold points in a non-Markovian dynamics. Furthermore, the lack of access to the precise information about the initial conditions or the past events plays a very relevant role in the correct estimation or prediction of the epidemic evolution. Such a "constraint" is analyzed and discussed.

  1. Lecture 7: Worldwide LHC Computing Grid Overview

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    This presentation will introduce in an informal, but technically correct way the challenges that are linked to the needs of massively distributed computing architectures in the context of the LHC offline computing. The topics include technological and organizational aspects touching many aspects of LHC computing, from data access, to maintenance of large databases and huge collections of files, to the organization of computing farms and monitoring. Fabrizio Furano holds a Ph.D in Computer Science and has worked in the field of Computing for High Energy Physics for many years. Some of his preferred topics include application architectures, system design and project management, with focus on performance and scalability of data access. Fabrizio has experience in a wide variety of environments, from private companies to academic research in particular in object oriented methodologies, mainly using C++. He has also teaching experience at university level in Software Engineering and C++ Programming.

  2. Human adenovirus type 8: the major agent of epidemic keratoconjunctivitis (EKC).

    Science.gov (United States)

    Adhikary, Arun Kumar; Banik, Urmila

    2014-12-01

    Human adenovirus type 8 (HAdV-8) is the most common causative agent of a highly contagious eye disease known as epidemic keratoconjunctivitis (EKC). HAdV-8 strains have been classified into genome types HAdV-8A to 8K and HAdV/D1 to D12 according to restriction endonuclease analysis. This review focuses on the significance of HAdV-8 as an agent of EKC. Molecular analysis of HAdV-8 genome types HAdV-53 and HAdV-54 was performed to reveal potential genetic variation in the hexon and fiber, which might affect the antigenicity and tropism of the virus, respectively. On the basis of the published data, three patterns of HAdV-8 genome type distribution were observed worldwide: (1) genome types restricted to a microenvironment, (2) genome types distributed within a country, and (3) globally dispersed genome types. Simplot and zPicture showed that the HAdV-8 genome types were nearly identical to each other. HAdV-54 is very close to the HAdV-8P, B and E genomes, except in the hexon. In a restriction map, HAdV-8P, B, and E share a very high percentage of restriction sites with each other. Hypervariable regions (HVRs) of the hexon were conserved and were 100% identical among the genome types. The fiber knob of HAdV-8P, A, E, J and HAdV-53 were 100% identical. In phylogeny, HVRs of the hexon and fiber knob of the HAdV-8 genome types segregated into monophyletic clusters. Neutralizing antibodies against one genome type will provide protection against other genome types, and the selection of future vaccine strains would be simple due to the stable HVRs. Molecular analysis of whole genomes, particularly of the capsid proteins of the remaining genome types, would be useful to substantiate our observations. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Inferring epidemiological parameters from phylogenetic information for the HIV-1 epidemic among MSM

    Science.gov (United States)

    Quax, Rick; van de Vijver, David A. M. C.; Frentz, Dineke; Sloot, Peter M. A.

    2013-09-01

    The HIV-1 epidemic in Europe is primarily sustained by a dynamic topology of sexual interactions among MSM who have individual immune systems and behavior. This epidemiological process shapes the phylogeny of the virus population. Both fields of epidemic modeling and phylogenetics have a long history, however it remains difficult to use phylogenetic data to infer epidemiological parameters such as the structure of the sexual network and the per-act infectiousness. This is because phylogenetic data is necessarily incomplete and ambiguous. Here we show that the cluster-size distribution indeed contains information about epidemiological parameters using detailed numberical experiments. We simulate the HIV epidemic among MSM many times using the Monte Carlo method with all parameter values and their ranges taken from literature. For each simulation and the corresponding set of parameter values we calculate the likelihood of reproducing an observed cluster-size distribution. The result is an estimated likelihood distribution of all parameters from the phylogenetic data, in particular the structure of the sexual network, the per-act infectiousness, and the risk behavior reduction upon diagnosis. These likelihood distributions encode the knowledge provided by the observed cluster-size distrbution, which we quantify using information theory. Our work suggests that the growing body of genetic data of patients can be exploited to understand the underlying epidemiological process.

  4. Climate Influence on Emerging Risk Areas for Rift Valley Fever Epidemics in Tanzania.

    Science.gov (United States)

    Mweya, Clement N; Mboera, Leonard E G; Kimera, Sharadhuli I

    2017-07-01

    Rift Valley Fever (RVF) is a climate-related arboviral infection of animals and humans. Climate is thought to represent a threat toward emerging risk areas for RVF epidemics globally. The objective of this study was to evaluate influence of climate on distribution of suitable breeding habitats for Culex pipiens complex, potential mosquito vector responsible for transmission and distribution of disease epidemics risk areas in Tanzania. We used ecological niche models to estimate potential distribution of disease risk areas based on vectors and disease co-occurrence data approach. Climatic variables for the current and future scenarios were used as model inputs. Changes in mosquito vectors' habitat suitability in relation to disease risk areas were estimated. We used partial receiver operating characteristic and the area under the curves approach to evaluate model predictive performance and significance. Habitat suitability for Cx. pipiens complex indicated broad-scale potential for change and shift in the distribution of the vectors and disease for both 2020 and 2050 climatic scenarios. Risk areas indicated more intensification in the areas surrounding Lake Victoria and northeastern part of the country through 2050 climate scenario. Models show higher probability of emerging risk areas spreading toward the western parts of Tanzania from northeastern areas and decrease in the southern part of the country. Results presented here identified sites for consideration to guide surveillance and control interventions to reduce risk of RVF disease epidemics in Tanzania. A collaborative approach is recommended to develop and adapt climate-related disease control and prevention strategies.

  5. Overview of glyphosate-resistant weeds worldwide.

    Science.gov (United States)

    Heap, Ian; Duke, Stephen O

    2017-10-10

    Glyphosate is the most widely used and successful herbicide discovered to date, but its utility is now threatened by the occurrence of several glyphosate-resistant weed species. Glyphosate resistance first appeared in Lolium rigidum in an apple orchard in Australia in 1996, ironically the year that the first glyphosate-resistant crop (soybean) was introduced in the USA. Thirty-eight weed species have now evolved resistance to glyphosate, distributed across 37 countries and in 34 different crops and six non-crop situations. Although glyphosate-resistant weeds have been identified in orchards, vineyards, plantations, cereals, fallow and non-crop situations, it is the glyphosate-resistant weeds in glyphosate-resistant crop systems that dominate the area infested and growing economic impact. Glyphosate-resistant weeds present the greatest threat to sustained weed control in major agronomic crops because this herbicide is used to control weeds with resistance to herbicides with other sites of action, and no new herbicide sites of action have been introduced for over 30 years. Industry has responded by developing herbicide resistance traits in major crops that allow existing herbicides to be used in a new way. However, over reliance on these traits will result in multiple-resistance in weeds. Weed control in major crops is at a precarious point, where we must maintain the utility of the herbicides we have until we can transition to new weed management technologies. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. [The epidemic process as a system. I. The structure of the epidemic process].

    Science.gov (United States)

    Cherkasskiĭ, B L

    1985-03-01

    A new epidemiological concept (socio-ecological) has been formulated on the basis of the principles of the theory of systems and the theory of information. In accordance with this concept, the epidemic process is organized on the same principle as living matter, and the stability of this process at all levels of its organization is ensured by the processes of self-regulation. The conditions of the life of human society have been shown to be organically incorporated into the structure of the epidemic process as a regulating subsystem on the socio-ecological level.

  7. A Bayesian method for inferring transmission chains in a partially observed epidemic.

    Energy Technology Data Exchange (ETDEWEB)

    Marzouk, Youssef M.; Ray, Jaideep

    2008-10-01

    We present a Bayesian approach for estimating transmission chains and rates in the Abakaliki smallpox epidemic of 1967. The epidemic affected 30 individuals in a community of 74; only the dates of appearance of symptoms were recorded. Our model assumes stochastic transmission of the infections over a social network. Distinct binomial random graphs model intra- and inter-compound social connections, while disease transmission over each link is treated as a Poisson process. Link probabilities and rate parameters are objects of inference. Dates of infection and recovery comprise the remaining unknowns. Distributions for smallpox incubation and recovery periods are obtained from historical data. Using Markov chain Monte Carlo, we explore the joint posterior distribution of the scalar parameters and provide an expected connectivity pattern for the social graph and infection pathway.

  8. Coevolution of Epidemics, Social Networks, and Individual Behavior: A Case Study

    Science.gov (United States)

    Chen, Jiangzhuo; Marathe, Achla; Marathe, Madhav

    This research shows how a limited supply of antivirals can be distributed optimally between the hospitals and the market so that the attack rate is minimized and enough revenue is generated to recover the cost of the antivirals. Results using an individual based model find that prevalence elastic demand behavior delays the epidemic and change in the social contact network induced by isolation reduces the peak of the epidemic significantly. A microeconomic analysis methodology combining behavioral economics and agent-based simulation is a major contribution of this work. In this paper we apply this methodology to analyze the fairness of the stockpile distribution, and the response of human behavior to disease prevalence level and its interaction with the market.

  9. Simulated epidemics in an empirical spatiotemporal network of 50,185 sexual contacts

    CERN Document Server

    Rocha, Luis Enrique Correa; Holme, Petter

    2010-01-01

    We study implications of the dynamical and spatial contact structure between Brazilian escorts and sex-buyers for the spreading of sexually transmitted infections (STI). Despite a highly skewed degree distribution diseases spreading in this contact structure have rather well-defined epidemic thresholds. Temporal effects create a broad distribution of outbreak sizes even if the transmission probability is taken to the hypothetical value of 100%. Temporal correlations speed up outbreaks, especially in the early phase, compared to randomized contact structures. The time-ordering and the network topology, on the other hand, slow down the epidemics. Studying compartmental models we show that the contact structure can probably not support the spread of HIV, not even if individuals were sexually active during the acute infection. We investigate hypothetical means of containing an outbreak and find that travel restrictions are about as efficient as removal of the vertices of highest degree. In general, the type of co...

  10. Unusual Dengue Virus 3 Epidemic in Nicaragua, 2009

    Science.gov (United States)

    Gutierrez, Gamaliel; Standish, Katherine; Narvaez, Federico; Perez, Maria Angeles; Saborio, Saira; Elizondo, Douglas; Ortega, Oscar; Nuñez, Andrea; Kuan, Guillermina; Balmaseda, Angel; Harris, Eva

    2011-01-01

    The four dengue virus serotypes (DENV1–4) cause the most prevalent mosquito-borne viral disease affecting humans worldwide. In 2009, Nicaragua experienced the largest dengue epidemic in over a decade, marked by unusual clinical presentation, as observed in two prospective studies of pediatric dengue in Managua. From August 2009–January 2010, 212 dengue cases were confirmed among 396 study participants at the National Pediatric Reference Hospital. In our parallel community-based cohort study, 170 dengue cases were recorded in 2009–10, compared to 13–65 cases in 2004–9. In both studies, significantly more patients experienced “compensated shock” (poor capillary refill plus cold extremities, tachycardia, tachypnea, and/or weak pulse) in 2009–10 than in previous years (42.5% [90/212] vs. 24.7% [82/332] in the hospital study (p<0.001) and 17% [29/170] vs. 2.2% [4/181] in the cohort study (p<0.001). Signs of poor peripheral perfusion presented significantly earlier (1–2 days) in 2009–10 than in previous years according to Kaplan-Meier survival analysis. In the hospital study, 19.8% of subjects were transferred to intensive care, compared to 7.1% in previous years – similar to the cohort study. DENV-3 predominated in 2008–9, 2009–10, and 2010–11, and full-length sequencing revealed no major genetic changes from 2008–9 to 2010–11. In 2008–9 and 2010–11, typical dengue was observed; only in 2009–10 was unusual presentation noted. Multivariate analysis revealed only “2009–10” as a significant risk factor for Dengue Fever with Compensated Shock. Interestingly, circulation of pandemic influenza A-H1N1 2009 in Managua was shifted such that it overlapped with the dengue epidemic. We hypothesize that prior influenza A H1N1 2009 infection may have modulated subsequent DENV infection, and initial results of an ongoing study suggest increased risk of shock among children with anti-H1N1-2009 antibodies. This study demonstrates that

  11. Unusual dengue virus 3 epidemic in Nicaragua, 2009.

    Directory of Open Access Journals (Sweden)

    Gamaliel Gutierrez

    2011-11-01

    Full Text Available The four dengue virus serotypes (DENV1-4 cause the most prevalent mosquito-borne viral disease affecting humans worldwide. In 2009, Nicaragua experienced the largest dengue epidemic in over a decade, marked by unusual clinical presentation, as observed in two prospective studies of pediatric dengue in Managua. From August 2009-January 2010, 212 dengue cases were confirmed among 396 study participants at the National Pediatric Reference Hospital. In our parallel community-based cohort study, 170 dengue cases were recorded in 2009-10, compared to 13-65 cases in 2004-9. In both studies, significantly more patients experienced "compensated shock" (poor capillary refill plus cold extremities, tachycardia, tachypnea, and/or weak pulse in 2009-10 than in previous years (42.5% [90/212] vs. 24.7% [82/332] in the hospital study (p<0.001 and 17% [29/170] vs. 2.2% [4/181] in the cohort study (p<0.001. Signs of poor peripheral perfusion presented significantly earlier (1-2 days in 2009-10 than in previous years according to Kaplan-Meier survival analysis. In the hospital study, 19.8% of subjects were transferred to intensive care, compared to 7.1% in previous years - similar to the cohort study. DENV-3 predominated in 2008-9, 2009-10, and 2010-11, and full-length sequencing revealed no major genetic changes from 2008-9 to 2010-11. In 2008-9 and 2010-11, typical dengue was observed; only in 2009-10 was unusual presentation noted. Multivariate analysis revealed only "2009-10" as a significant risk factor for Dengue Fever with Compensated Shock. Interestingly, circulation of pandemic influenza A-H1N1 2009 in Managua was shifted such that it overlapped with the dengue epidemic. We hypothesize that prior influenza A H1N1 2009 infection may have modulated subsequent DENV infection, and initial results of an ongoing study suggest increased risk of shock among children with anti-H1N1-2009 antibodies. This study demonstrates that parameters other than serotype, viral

  12. Molecular Epidemiological Study of Mumps Epidemics of 2015 in Okinawa, Japan.

    Science.gov (United States)

    Kuba, Yumani; Kyan, Hisako; Arakaki, Eri; Takara, Taketoshi; Kato, Takashi; Okano, Sho; Oshiro, Yuko; Kudaka, Jun; Kidokoro, Minoru

    2017-05-24

    Although major mumps epidemics occurred every 4-5 years in Okinawa Prefecture in Japan, no laboratory diagnoses were conducted. A mumps epidemic started in Okinawa in October 2014, and we collected clinical samples from 31 patients in 4 areas (Hokubu, Nanbu, Miyako, and Yaeyama) from July to December 2015, for virus isolation and RT-PCR, whose positive ratios were 52% and 87%, respectively. Phylogenetic analyses showed that all isolates were classified into genotype G, and with one exception, consisted of 2 subgenotypes, Ge (55.6%) and Gw (40.7%), which have been prominent in Japan recently. One isolate was classified in another lineage, which was detected in Japan for the first time, and was similar to a Hong Kong isolate from 2014. Remarkably, the geographic distributions of the 2 major lineages were separated. The Ge viruses were isolated from the main island of Okinawa and the Yaeyama Islands, whereas the Gw isolates were mainly detected from the Miyako Islands. These results suggest that the Ge and Gw mumps viruses mainly caused the mumps epidemics of 2015 in Okinawa, and that they spread independently in separate regions. This is the first report describing the molecular epidemiology of mumps epidemics in Okinawa Prefecture.

  13. Modeling workplace contact networks: The effects of organizational structure, architecture, and reporting errors on epidemic predictions.

    Science.gov (United States)

    Potter, Gail E; Smieszek, Timo; Sailer, Kerstin

    2015-09-01

    Face-to-face social contacts are potentially important transmission routes for acute respiratory infections, and understanding the contact network can improve our ability to predict, contain, and control epidemics. Although workplaces are important settings for infectious disease transmission, few studies have collected workplace contact data and estimated workplace contact networks. We use contact diaries, architectural distance measures, and institutional structures to estimate social contact networks within a Swiss research institute. Some contact reports were inconsistent, indicating reporting errors. We adjust for this with a latent variable model, jointly estimating the true (unobserved) network of contacts and duration-specific reporting probabilities. We find that contact probability decreases with distance, and that research group membership, role, and shared projects are strongly predictive of contact patterns. Estimated reporting probabilities were low only for 0-5 min contacts. Adjusting for reporting error changed the estimate of the duration distribution, but did not change the estimates of covariate effects and had little effect on epidemic predictions. Our epidemic simulation study indicates that inclusion of network structure based on architectural and organizational structure data can improve the accuracy of epidemic forecasting models.

  14. Social and economic influences on human behavioural response in an emerging epidemic

    Science.gov (United States)

    Phang, P.; Wiwatanapataphee, B.; Wu, Y. H.

    2017-10-01

    The human behavioural changes have been recognized as an important key in shaping the disease spreading and determining the success of control measures in the course of epidemic outbreaks. However, apart from cost-benefit considerations, in reality, people are heterogeneous in their preferences towards adopting certain protective actions to reduce their risk of infection, and social norms have a function in individuals’ decision making. Here, we studied the interplay between the epidemic dynamics, imitation dynamics and the heterogeneity of individual protective behavioural response under the considerations of both economic and social factors, with a simple mathematical compartmental model and multi-population game dynamical replicator equations. We assume that susceptibles in different subpopulations have different preferences in adopting either normal or altered behaviour. By incorporating both intra- and inter-group social pressure, the outcome of the strategy distribution depends on the initial proportion of susceptible with normal and altered strategies in both subpopulations. The increase of additional cost to susceptible with altered behaviour will discourage people to take up protective actions and hence results in higher epidemic final size. For a specific cost of altered behaviour, the social group pressure could be a “double edge sword”, though. We conclude that the interplays between individual protective behaviour adoption, imitation and epidemic dynamics are necessarily complex if both economic and social factors act on populations with existing preferences.

  15. Characterization of dengue epidemics in mainland China over the past decade.

    Science.gov (United States)

    Ren, Hongyan; Ning, Wenyan; Lu, Liang; Zhuang, Dafang; Liu, Qiyong

    2015-09-27

    Dengue is an important public health concern in developing countries. As it is increasingly serious in mainland China, its spatiotemporal variations in this region must be further understood. On the basis of the data on dengue cases in 2004-2013 collected from the China Information System for Disease Control and Prevention, examinations of spatiotemporal variations of local, imported, and total dengue cases were conducted to characterize this epidemic at the city scale in China. Local cases in September and October accounted for more than half of the total cases in each year. The cities with more than 50 accumulative local cases were mainly distributed along the southeast coastal areas and southwest border regions of China. In 2004-2013, local dengue transmission (indicated by the number of local cases and the locally infected cities) increased yearly and was closely associated with epidemics (represented by the amount of imported cases and the cities with imported cases). At the city level, local transmission tended to be spatially clustered in the Zhejiang-Fujian coastal area, the Pearl River Delta, and Yunnan-Burma border region, especially in 2005, 2010, 2012, and 2013. The results showed that China's local dengue transmission is spatially and temporally featured, and that the prevalence of this epidemic is mostly related to imported cases from overseas epidemic areas. This study provides useful support for hygiene authorities of central and local governments to take effective measures to prevent and control this disease.

  16. Spatiotemporal modelling and mapping of the bubonic plague epidemic in India

    Directory of Open Access Journals (Sweden)

    Christakos George

    2006-03-01

    Full Text Available Abstract Background This work studies the spatiotemporal evolution of bubonic plague in India during 1896–1906 using stochastic concepts and geographical information science techniques. In the past, most investigations focused on selected cities to conduct different kinds of studies, such as the ecology of rats. No detailed maps existed incorporating the space-time dependence structure and uncertainty sources of the epidemic system and providing a composite space-time picture of the disease propagation characteristics. Results Informative spatiotemporal maps were generated that represented mortality rates and geographical spread of the disease, and epidemic indicator plots were derived that offered meaningful characterizations of the spatiotemporal disease distribution. The bubonic plague in India exhibited strong seasonal and geographical features. During its entire duration, the plague continued to invade new geographical areas, while it followed a re-emergence pattern at many localities; its rate changed significantly during each year and the mortality distribution exhibited space-time heterogeneous patterns; prevalence usually occurred in the autumn and spring, whereas the plague stopped moving towards new locations during the summers. Conclusion Modern stochastic modelling and geographical information science provide powerful means to study the spatiotemporal distribution of the bubonic plague epidemic under conditions of uncertainty and multi-sourced databases; to account for various forms of interdisciplinary knowledge; and to generate informative space-time maps of mortality rates and propagation patterns. To the best of our knowledge, this kind of plague maps and plots become available for the first time, thus providing novel perspectives concerning the distribution and space-time propagation of the deadly epidemic. Furthermore, systematic maps and indicator plots make possible the comparison of the spatial-temporal propagation

  17. Spatiotemporal modelling and mapping of the bubonic plague epidemic in India.

    Science.gov (United States)

    Yu, Hwa-Lung; Christakos, George

    2006-03-17

    This work studies the spatiotemporal evolution of bubonic plague in India during 1896-1906 using stochastic concepts and geographical information science techniques. In the past, most investigations focused on selected cities to conduct different kinds of studies, such as the ecology of rats. No detailed maps existed incorporating the space-time dependence structure and uncertainty sources of the epidemic system and providing a composite space-time picture of the disease propagation characteristics. Informative spatiotemporal maps were generated that represented mortality rates and geographical spread of the disease, and epidemic indicator plots were derived that offered meaningful characterizations of the spatiotemporal disease distribution. The bubonic plague in India exhibited strong seasonal and geographical features. During its entire duration, the plague continued to invade new geographical areas, while it followed a re-emergence pattern at many localities; its rate changed significantly during each year and the mortality distribution exhibited space-time heterogeneous patterns; prevalence usually occurred in the autumn and spring, whereas the plague stopped moving towards new locations during the summers. Modern stochastic modelling and geographical information science provide powerful means to study the spatiotemporal distribution of the bubonic plague epidemic under conditions of uncertainty and multi-sourced databases; to account for various forms of interdisciplinary knowledge; and to generate informative space-time maps of mortality rates and propagation patterns. To the best of our knowledge, this kind of plague maps and plots become available for the first time, thus providing novel perspectives concerning the distribution and space-time propagation of the deadly epidemic. Furthermore, systematic maps and indicator plots make possible the comparison of the spatial-temporal propagation patterns of different diseases.

  18. Event history analysis of dengue fever epidemic and inter-epidemic spells in Barbados, Brazil, and Thailand.

    Science.gov (United States)

    Parker, Daniel; Holman, Darryl

    2012-11-01

    This study investigated meteorological and demographic factors affecting the length of dengue fever epidemics and the length of time between epidemics in Barbados, Brazil, and Thailand. Region-specific meteorological and demographic data were collected for 104 sites from public sources. Fixed effects piecewise logistic event history analysis was used to quantify the effects of time-varying covariates on the duration of inter-epidemic spells and for the duration of epidemics. Mean monthly temperature was the most important factor affecting the duration of both inter-epidemic spells (β=0.543; confidence interval (CI) 0.4954, 0.5906) and epidemic spells (β=-0.648; CI -0.7553, -0.5405). Drought conditions increased the time between epidemics. Increased temperature hastened the onset of an epidemic, and during an epidemic, higher mean temperature increased the duration of the epidemic. By using a duration analysis, this study offers a novel approach for investigating the dynamics of dengue fever epidemiology. Furthermore, these results offer new insights into prior findings of a correlation between temperature and the geographic range and vector efficiency of dengue fever. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  19. Castor bean organelle genome sequencing and worldwide genetic diversity analysis.

    Directory of Open Access Journals (Sweden)

    Maximo Rivarola

    Full Text Available Castor bean is an important oil-producing plant in the Euphorbiaceae family. Its high-quality oil contains up to 90% of the unusual fatty acid ricinoleate, which has many industrial and medical applications. Castor bean seeds also contain ricin, a highly toxic Type 2 ribosome-inactivating protein, which has gained relevance in recent years due to biosafety concerns. In order to gain knowledge on global genetic diversity in castor bean and to ultimately help the development of breeding and forensic tools, we carried out an extensive chloroplast sequence diversity analysis. Taking advantage of the recently published genome sequence of castor bean, we assembled the chloroplast and mitochondrion genomes extracting selected reads from the available whole genome shotgun reads. Using the chloroplast reference genome we used the methylation filtration technique to readily obtain draft genome sequences of 7 geographically and genetically diverse castor bean accessions. These sequence data were used to identify single nucleotide polymorphism markers and phylogenetic analysis resulted in the identification of two major clades that were not apparent in previous population genetic studies using genetic markers derived from nuclear DNA. Two distinct sub-clades could be defined within each major clade and large-scale genotyping of castor bean populations worldwide confirmed previously observed low levels of genetic diversity and showed a broad geographic distribution of each sub-clade.

  20. Two approaches to forecast Ebola synthetic epidemics.

    Science.gov (United States)

    Champredon, David; Li, Michael; Bolker, Benjamin M; Dushoff, Jonathan

    2017-02-24

    We use two modelling approaches to forecast synthetic Ebola epidemics in the context of the RAPIDD Ebola Forecasting Challenge. The first approach is a standard stochastic compartmental model that aims to forecast incidence, hospitalization and deaths among both the general population and health care workers. The second is a model based on the renewal equation with latent variables that forecasts incidence in the whole population only. We describe fitting and forecasting procedures for each model and discuss their advantages and drawbacks. We did not find that one model was consistently better in forecasting than the other. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  1. Patterns of selectivity in introductions of mammal species worldwide

    Directory of Open Access Journals (Sweden)

    Tim M. Blackburn

    2017-01-01

    Full Text Available Humans have an extremely long history of transporting and introducing mammal species outside their native geographic ranges. The characteristics of the species introduced (taxonomy, life-history, ecology, environment can all influence which traits are available (and selected for establishment, and subsequent invasive spread. Understanding the non-randomness in species introductions is therefore key to understanding invasions by alien species. Here, we test for selectivity in the identities and traits of mammal species introduced worldwide. We compiled and analysed a comprehensive database of introduced mammal species, including information on a broad range of life history, ecological, distributional and environmental variables that we predicted to differ between introduced and non-introduced mammal species. Certain mammal taxa are much more likely to have been introduced than expected, such as Artiodactyls in the families Bovidae and Cervidae. Rodents and bats were much less likely to have been introduced than expected. Introduced mammal species have significantly larger body masses, longer lifespans and larger litter sizes than a random sample of all mammal species. They also have much larger native geographic ranges than expected, originate from significantly further north, from cooler areas, and from areas with higher human population densities, than mammal species with no recorded introductions. The traits and distributions of species help determine which have been introduced, and reflect how the evolutionary history of mammals has resulted in certain species with certain traits being located in the way of human histories of movement and demands for goods and services. The large amount of unexplained variation is likely to relate to the intrinsically stochastic nature of this human-driven process.

  2. Monitoring and prediction of an epidemic outbreak using syndromic observations

    OpenAIRE

    Skvortsov, Alex; Ristic, Branko

    2011-01-01

    The paper presents an algorithm for syndromic surveillance of an epidemic outbreak formulated in the context of stochastic nonlinear filtering. The dynamics of the epidemic is modeled using a generalized compartmental epidemiological model with inhomogeneous mixing. The syndromic (typically non-medical) observations of the number of infected people (e.g. visits to pharmacies, sale of certain products, absenteeism from work/study etc.) are used for estimation. The state of the epidemic, includ...

  3. Spatio-temporal variation in prevalence of Rift Valley fever: a post-epidemic serum survey in cattle and wildlife in Kenya

    Directory of Open Access Journals (Sweden)

    Olivia Wesula Lwande

    2015-12-01

    Full Text Available Background: Rift Valley fever (RVF is a fatal arthropod-borne zoonotic disease of livestock and humans. Since the identification of RVF in Kenya in the 1930s, repeated epizootics and epidemics coinciding with El Niño events have occurred in several locations in Africa and Saudi Arabia, causing mass deaths of livestock and humans. RVF is of great interest worldwide because of its negative effect on international livestock trade and its potential to spread globally. The latter is due to the increasing incidence of extreme climatic phenomena caused by global warming, as well as to the increase in global trade and international travel. How RVF is maintained and sustained between epidemics and epizootics is not clearly understood, but it has been speculated that wildlife reservoirs and trans-ovarian transmission in the vector may be important. Several studies have examined the role of wildlife and livestock in isolation or in a limited geographical location within the one country over a short time (usually less than a year. In this study, we examined the seroprevalence of anti-RVF antibodies in cattle and several wildlife species from several locations in Kenya over an inter-epidemic period spanning up to 7 years. Methods: A serological survey of immunoglobulin G (IgG antibodies to RVF using competitive ELISA was undertaken on 297 serum samples from different wildlife species at various locations in Kenya. The samples were collected between 2008 and 2015. Serum was also collected in 2014 from 177 cattle from Ol Pejeta Conservancy; 113 of the cattle were in close contact with wildlife and the other 64 were kept separate from buffalo and large game by an electric fence. Results: The seroprevalence of RVF virus (RVFV antibody was 11.6% in wildlife species during the study period. Cattle that could come in contact with wildlife and large game were all negative for RVFV. The seroprevalence was relatively high in elephants, rhinoceros, and buffalo, but

  4. A generalized cholera model and epidemic-endemic analysis

    National Research Council Canada - National Science Library

    Wang, Jin; Liao, Shu

    2012-01-01

    .... Particularly, this work unifies many existing cholera models proposed by different authors. We conduct equilibrium analysis to carefully study the complex epidemic and endemic behaviour of the disease...

  5. Behavioral synchronization induced by epidemic spread in complex networks

    Science.gov (United States)

    Sun, Mengfeng; Lou, Yijun; Duan, Jinqiao; Fu, Xinchu

    2017-06-01

    During the spread of an epidemic, individuals in realistic networks may exhibit collective behaviors. In order to characterize this kind of phenomenon and explore the correlation between collective behaviors and epidemic spread, in this paper, we construct several mathematical models (including without delay, with a coupling delay, and with double delays) of epidemic synchronization by applying the adaptive feedback motivated by real observations. By using Lyapunov function methods, we obtain the conditions for local and global stability of these epidemic synchronization models. Then, we illustrate that quenched mean-field theory is more accurate than heterogeneous mean-field theory in the prediction of epidemic synchronization. Finally, some numerical simulations are performed to complement our theoretical results, which also reveal some unexpected phenomena, for example, the coupling delay and epidemic delay influence the speed of epidemic synchronization. This work makes further exploration on the relationship between epidemic dynamics and synchronization dynamics, in the hope of being helpful to the study of other dynamical phenomena in the process of epidemic spread.

  6. Kuru: the old epidemic in a new mirror.

    Science.gov (United States)

    Goldfarb, Lev G

    2002-07-01

    The kuru epidemic lasted almost a century; it started in 1901-1902, reached epidemic proportions in the mid-1950s, and disappeared in the 1990s. Kuru is the prototype member of a group of disorders known as transmissible spongiform encephalopathies (TSEs) or prion diseases. Recent data on the genetics and pathogenesis of TSEs contribute to a better understanding of the documented kuru phenomena, and vice versa, observations made during the kuru epidemic are immensely helpful in understanding the epidemic of variant Creutzfeldt-Jakob disease that is currently developing in Europe. The major goal of this review is to identify and illustrate these points.

  7. Epidemics: Lessons from the past and current patterns of response

    Science.gov (United States)

    Martin, Paul

    2008-09-01

    Hippocrates gave the term 'epidemic' its medical meaning. From antiquity to modern times, the meaning of the word epidemic has continued to evolve. Over the centuries, researchers have reached an understanding of the varying aspects of epidemics and have tried to combat them. The role played by travel, trade, and human exchanges in the propagation of epidemic infectious diseases has been understood. In 1948, the World Health Organization was created and given the task of advancing ways of combating epidemics. An early warning system to combat epidemics has been implemented by the WHO. The Global Outbreak Alert and Response Network (GOARN) is collaboration between existing institutions and networks that pool their human and technical resources to fight outbreaks. Avian influenza constitutes currently the most deadly epidemic threat, with fears that it could rapidly reach pandemic proportions and put several thousands of lives in jeopardy. Thanks to the WHO's support, most of the world's countries have mobilised and implemented an 'Action Plan for Pandemic Influenza'. As a result, most outbreaks of the H5N1 avian flu virus have so far been speedily contained. Cases of dengue virus introduction in countries possessing every circumstance required for its epidemic spread provide another example pertinent to the prevention of epidemics caused by vector-borne pathogens.

  8. Colliding Epidemics and the Rise of Cryptococcosis

    Directory of Open Access Journals (Sweden)

    Christina C. Chang

    2015-12-01

    Full Text Available Discovered more than 100 years ago as a human pathogen, the Cryptococcus neoformans–Cryptococcus gattii (C. neoformans–C. gattii complex has seen a large global resurgence in its association with clinical disease in the last 30 years. First isolated in fermenting peach juice, and identified as a human pathogen in 1894 in a patient with bone lesions, this environmental pathogen has now found niches in soil, trees, birds, and domestic pets. Cryptococcosis is well recognized as an opportunistic infection and was first noted to be associated with reticuloendothelial cancers in the 1950s. Since then, advances in transplant immunology, medical science and surgical techniques have led to increasing numbers of solid organ transplantations (SOT and hematological stem cell transplantations being performed, and the use of biological immunotherapeutics in increasingly high-risk and older individuals, have contributed to the further rise in cryptococcosis. Globally, however, the major driver for revivification of cryptococcosis is undoubtedly the HIV epidemic, particularly in Sub-Saharan Africa where access to care and antiretroviral therapy remains limited and advanced immunodeficiency, poverty and malnutrition remains the norm. As a zoonotic disease, environmental outbreaks of both human and animal cryptococcosis have been reported, possibly driven by climate change. This is best exemplified by the resurgence of C. gattii infection in Vancouver Island, Canada, and the Pacific Northwest of the United States since 1999. Here we describe how the colliding epidemics of HIV, transplantation and immunologics, climate change and migration have contributed to the rise of cryptococcosis.

  9. The opioid overdose epidemic: opportunities for pharmacists

    Directory of Open Access Journals (Sweden)

    Wu LT

    2017-07-01

    Full Text Available Li-Tzy Wu,1–4 Udi E Ghitza,5 Anne L Burns,6 Paolo Mannelli,1 1Department of Psychiatry and Behavioral Sciences, 2Department of Medicine, 3Duke Clinical Research Institute, Duke University School of Medicine, 4Center for Child and Family Policy, Sanford School of Public Policy, Duke University, Durham, NC, 5Center for Clinical Trials Network, National Institute on Drug Abuse, Bethesda, MD, 6American Pharmacists Association, Washington, DC, USA The USA is experiencing an opioid overdose epidemic. It has been driven largely by prescription opioids and intensified by a surge of illicit opioids (e.g., heroin and fentanyl.1,2 Drug-involved overdose, mainly opioids (e.g., prescription opioids and heroin, is a leading cause of accidental death in the USA. The opioid overdose epidemic has been escalating consistently for over a decade.2 Every day, an estimated 91 Americans die from opioid-related overdose.3 Opioid overdose appears to have disproportionally affected men, adults aged 25–64 years, and non-Hispanic whites.2

  10. [Epidemic process of gonorrhea in modern world].

    Science.gov (United States)

    Kostiukova, N N; Bekhalo, V A

    2009-01-01

    Gonorrhea in spite of its fully elucidated etiopathogenesis and available drugs for etiotropic therapy belongs to infections which are not controlled by vaccination due to absence of immunity formation. Analysis of scientific publication, statistical materials and WHO's data showed that epidemic process of gonorrhea infection depends mainly from people's behaviour, first of all, sexual. Modern epidemic process of gonorrhea infection consists from irregular increases and decreases of incidence due to various reasons. Reasons for increases of incidence appear to be simultaneous action of a range of biologic and anthropogenic factors. First reason--rapid increase of resistance of gonococci to widely used antibacterial preparations as well as synergy of pathogenic effects between HIV and gonococci; anthropogenic--wars, increase of high-risk groups due to urbanization, use of oral contraceptives, rise of prostitution, migration, inadequate access to medical care, poverty, intensification of intercourses (including hetero- and homosexual) between people, as well as demographic changes--increase of proportion of young people in population structure. Same but reciprocal factors lead to decrease of morbidity. Of them, the following were considered as most important: mass implementation of new effective antimicrobial drug as well as intensification of sanitary education, availability of early diagnostics and treatment, increase of material and cultural standards of life, decrease in number of persons belonging to high risk groups. Yet, capabilities of modern science expressed only in continuous development of new antibacterial drugs active against circulating population of gonococci, which is resistant to previously used drug.

  11. Epidemic contact tracing via communication traces.

    Directory of Open Access Journals (Sweden)

    Katayoun Farrahi

    Full Text Available Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  12. Nepalese origin of cholera epidemic in Haiti.

    Science.gov (United States)

    Frerichs, R R; Keim, P S; Barrais, R; Piarroux, R

    2012-06-01

    Cholera appeared in Haiti in October 2010 for the first time in recorded history. The causative agent was quickly identified by the Haitian National Public Health Laboratory and the United States Centers for Disease Control and Prevention as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Since then, >500 000 government-acknowledged cholera cases and >7000 deaths have occurred, the largest cholera epidemic in the world, with the real death toll probably much higher. Questions of origin have been widely debated with some attributing the onset of the epidemic to climatic factors and others to human transmission. None of the evidence on origin supports climatic factors. Instead, recent epidemiological and molecular-genetic evidence point to the United Nations peacekeeping troops from Nepal as the source of cholera to Haiti, following their troop rotation in early October 2010. Such findings have important policy implications for shaping future international relief efforts. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

  13. Absolute Humidity and Pandemic Versus Epidemic Influenza

    Science.gov (United States)

    Shaman, Jeffrey; Goldstein, Edward; Lipsitch, Marc

    2011-01-01

    Experimental and epidemiologic evidence indicates that variations of absolute humidity account for the onset and seasonal cycle of epidemic influenza in temperate regions. A role for absolute humidity in the transmission of pandemic influenza, such as 2009 A/H1N1, has yet to be demonstrated and, indeed, outbreaks of pandemic influenza during more humid spring, summer, and autumn months might appear to constitute evidence against an effect of humidity. However, here the authors show that variations of the basic and effective reproductive numbers for influenza, caused by seasonal changes in absolute humidity, are consistent with the general timing of pandemic influenza outbreaks observed for 2009 A/H1N1 in temperate regions, as well as wintertime transmission of epidemic influenza. Indeed, absolute humidity conditions correctly identify the region of the United States vulnerable to a third, wintertime wave of pandemic influenza. These findings suggest that the timing of pandemic influenza outbreaks is controlled by a combination of absolute humidity conditions, levels of susceptibility, and changes in population-mixing and contact rates. PMID:21081646

  14. Resource allocation for epidemic control in metapopulations.

    Directory of Open Access Journals (Sweden)

    Martial L Ndeffo Mbah

    Full Text Available Deployment of limited resources is an issue of major importance for decision-making in crisis events. This is especially true for large-scale outbreaks of infectious diseases. Little is known when it comes to identifying the most efficient way of deploying scarce resources for control when disease outbreaks occur in different but interconnected regions. The policy maker is frequently faced with the challenge of optimizing efficiency (e.g. minimizing the burden of infection while accounting for social equity (e.g. equal opportunity for infected individuals to access treatment. For a large range of diseases described by a simple SIRS model, we consider strategies that should be used to minimize the discounted number of infected individuals during the course of an epidemic. We show that when faced with the dilemma of choosing between socially equitable and purely efficient strategies, the choice of the control strategy should be informed by key measurable epidemiological factors such as the basic reproductive number and the efficiency of the treatment measure. Our model provides new insights for policy makers in the optimal deployment of limited resources for control in the event of epidemic outbreaks at the landscape scale.

  15. Global Impressions: Inside UNESCO's First Worldwide Arts Education Conference

    Science.gov (United States)

    Booth, Eric

    2006-01-01

    The many worlds of arts education began to grow into one worldwide community in March 2006. Twelve hundred arts education leaders, in delegations from 97 countries, attended the United Nation's Education, Scientific and Cultural Organization's (UNESCO's) first-ever worldwide arts education conference, held for four days in Lisbon, Portugal. The…

  16. Genetic and phylogenetic evolution of HIV-1 in a low subtype heterogeneity epidemic: the Italian example

    Directory of Open Access Journals (Sweden)

    Tornesello Maria

    2007-05-01

    Full Text Available Abstract The Human Immunodeficiency Virus type 1 (HIV-1 is classified into genetic groups, subtypes and sub-subtypes which show a specific geographic distribution pattern. The HIV-1 epidemic in Italy, as in most of the Western Countries, has traditionally affected the Intra-venous drug user (IDU and Homosexual (Homo risk groups and has been sustained by the genetic B subtype. In the last years, however, the HIV-1 transmission rate among heterosexuals has dramatically increased, becoming the prevalent transmission route. In fact, while the traditional risk groups have high levels of knowledge and avoid high-risk practices, the heterosexuals do not sufficiently perceive the risk of HIV-1 infection. This misperception, linked to the growing number of immigrants from non-Western Countries, where non-B clades and circulating recombinant forms (CRFs are prevalent, is progressively introducing HIV-1 variants of non-B subtype in the Italian epidemic. This is in agreement with reports from other Western European Countries. In this context, the Italian HIV-1 epidemic is still characterized by low subtype heterogeneity and represents a paradigmatic example of the European situation. The continuous molecular evolution of the B subtype HIV-1 isolates, characteristic of a long-lasting epidemic, together with the introduction of new subtypes as well as recombinant forms may have significant implications for diagnostic, treatment, and vaccine development. The study and monitoring of the genetic evolution of the HIV-1 represent, therefore, an essential strategy for controlling the local as well as global HIV-1 epidemic and for developing efficient preventive and therapeutic strategies.

  17. Mutually cooperative epidemics on power-law networks

    Science.gov (United States)

    Cui, Peng-Bi; Colaiori, Francesca; Castellano, Claudio

    2017-08-01

    The spread of an infectious disease can, in some cases, promote the propagation of other pathogens favoring violent outbreaks, which cause a discontinuous transition to an endemic state. The topology of the contact network plays a crucial role in these cooperative dynamics. We consider a susceptible-infected-removed-type model with two mutually cooperative pathogens: An individual already infected with one disease has an increased probability of getting infected by the other. We present a heterogeneous mean-field theoretical approach to the coinfection dynamics on generic uncorrelated power-law degree-distributed networks and validate its results by means of numerical simulations. We show that, when the second moment of the degree distribution is finite, the epidemic transition is continuous for low cooperativity, while it is discontinuous when cooperativity is sufficiently high. For scale-free networks, i.e., topologies with diverging second moment, the transition is instead always continuous. In this way we clarify the effect of heterogeneity and system size on the nature of the transition, and we validate the physical interpretation about the origin of the discontinuity.

  18. Mutually cooperative epidemics on power-law networks.

    Science.gov (United States)

    Cui, Peng-Bi; Colaiori, Francesca; Castellano, Claudio

    2017-08-01

    The spread of an infectious disease can, in some cases, promote the propagation of other pathogens favoring violent outbreaks, which cause a discontinuous transition to an endemic state. The topology of the contact network plays a crucial role in these cooperative dynamics. We consider a susceptible-infected-removed-type model with two mutually cooperative pathogens: An individual already infected with one disease has an increased probability of getting infected by the other. We present a heterogeneous mean-field theoretical approach to the coinfection dynamics on generic uncorrelated power-law degree-distributed networks and validate its results by means of numerical simulations. We show that, when the second moment of the degree distribution is finite, the epidemic transition is continuous for low cooperativity, while it is discontinuous when cooperativity is sufficiently high. For scale-free networks, i.e., topologies with diverging second moment, the transition is instead always continuous. In this way we clarify the effect of heterogeneity and system size on the nature of the transition, and we validate the physical interpretation about the origin of the discontinuity.

  19. Statistics of Epidemics in Networks by Passing Messages

    Science.gov (United States)

    Shrestha, Munik Kumar

    Epidemic processes are common out-of-equilibrium phenomena of broad interdisciplinary interest. In this thesis, we show how message-passing approach can be a helpful tool for simulating epidemic models in disordered medium like networks, and in particular for estimating the probability that a given node will become infectious at a particular time. The sort of dynamics we consider are stochastic, where randomness can arise from the stochastic events or from the randomness of network structures. As in belief propagation, variables or messages in message-passing approach are defined on the directed edges of a network. However, unlike belief propagation, where the posterior distributions are updated according to Bayes' rule, in message-passing approach we write differential equations for the messages over time. It takes correlations between neighboring nodes into account while preventing causal signals from backtracking to their immediate source, and thus avoids "echo chamber effects" where a pair of adjacent nodes each amplify the probability that the other is infectious. In our first results, we develop a message-passing approach to threshold models of behavior popular in sociology. These are models, first proposed by Granovetter, where individuals have to hear about a trend or behavior from some number of neighbors before adopting it themselves. In thermodynamic limit of large random networks, we provide an exact analytic scheme while calculating the time dependence of the probabilities and thus learning about the whole dynamics of bootstrap percolation, which is a simple model known in statistical physics for exhibiting discontinuous phase transition. As an application, we apply a similar model to financial networks, studying when bankruptcies spread due to the sudden devaluation of shared assets in overlapping portfolios. We predict that although diversification may be good for individual institutions, it can create dangerous systemic effects, and as a result

  20. Residential surface soil guidance values applied worldwide to the original 2001 Stockholm Convention POP pesticides.

    Science.gov (United States)

    Jennings, Aaron A; Li, Zijian

    2015-09-01

    Surface soil contamination is a worldwide problem. Many regulatory jurisdictions attempt to control human exposures with regulatory guidance values (RGVs) that specify a soil's maximum allowable concentration. Pesticides are important soil contaminants because of their intentional toxicity and widespread surface soil application. Worldwide, at least 174 regulatory jurisdictions from 54 United Nations member states have published more than 19,400 pesticide RGVs for at least 739 chemically unique pesticides. This manuscript examines the variability of the guidance values that are applied worldwide to the original 2001 Stockholm Convention persistent organic pollutants (POP) pesticides (Aldrin, Chlordane, DDT, Dieldrin, Endrin, Heptachlor, Mirex, and Toxaphene) for which at least 1667 RGVs have been promulgated. Results indicate that the spans of the RGVs applied to each of these pesticides vary from 6.1 orders of magnitude for Toxaphene to 10.0 orders of magnitude for Mirex. The distribution of values across these value spans resembles the distribution of lognormal random variables, but also contain non-random value clusters. Approximately 40% of all the POP RGVs fall within uncertainty bounds computed from the U.S. Environmental Protection Agency (USEPA) RGV cancer risk model. Another 22% of the values fall within uncertainty bounds computed from the USEPA's non-cancer risk model, but the cancer risk calculations yield the binding (lowest) value for all POP pesticides except Endrin. The results presented emphasize the continued need to rationalize the RGVs applied worldwide to important soil contaminants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Worldwide complete spherical Bouguer and isostatic anomaly maps

    Science.gov (United States)

    Bonvalot, S.; Balmino, G.; Briais, A.; Peyrefitte, A.; Vales, N.; Biancale, R.; Gabalda, G.; Reinquin, F.

    2011-12-01

    We present here a set of digital maps of the Earth's gravity anomalies (surface "free air", Bouguer and isostatic), computed at Bureau Gravimetric International (BGI) as a contribution to the Global Geodetic Observing Systems (GGOS) and to the global geophysical maps published by the Commission for the Geological Map of the World (CGMW). The free air and Bouguer anomaly concept is extensively used in geophysical interpretation to investigate the density distributions in the Earth's interior. Complete Bouguer anomalies (including terrain effects) are usually computed at regional scales by integrating the gravity attraction of topography elements over and beyond a given area (under planar or spherical approximations). Here, we developed and applied a worldwide spherical approach aimed to provide a set of homogeneous and high resolution gravity anomaly maps and grids computed at the Earth's surface, taking into account a realistic Earth model and reconciling geophysical and geodetic definitions of gravity anomalies. This first version (1.0) has been computed by spherical harmonics analysis / synthesis of the Earth's topography-bathymetry up to degree 10800. The detailed theory of the spherical harmonics approach is given in Balmino et al., (Journal of Geodesy, submitted). The Bouguer and terrain corrections have thus been computed in spherical geometry at 1'x1' resolution using the ETOPO1 topography/bathymetry, ice surface and bedrock models from the NOAA (National Oceanic and Atmospheric Administration) and taking into account precise characteristics (boundaries and densities) of major lakes, inner seas, polar caps and of land areas below sea level. Isostatic corrections have been computed according to the Airy Heiskanen model in spherical geometry for a constant depth of compensation of 30km. The gravity information given here is provided by the Earth Geopotential Model (EGM2008), developed at degree 2160 by the National Geospatial Intelligence Agency (NGA) (Pavlis

  2. Smoking epidemic eradication in a eco-epidemiological dynamical model

    NARCIS (Netherlands)

    Voorn, van G.A.K.; Kooi, B.W.

    2013-01-01

    Smoking is perceived as a major epidemic with regard to mortality. Modelling is a major tool used to obtain insight in the dynamics and possible solutions to decrease or even eradicate this epidemic. Most models on smoking consider the epidemiological context explicitly, in which smoking is regarded

  3. Gendered Epidemics and Systems of Power in Africa: A Feminist ...

    African Journals Online (AJOL)

    The article uses case studies, extracted from published epidemic stories and interprets these cases from a feminist and power analytical framework. The results suggest that while a disease or an epidemic affect a group of individuals, systemic factors regarding responsible governance and the role of national politics and ...

  4. Forests in transition: Post-epidemic vegetation conditions [Chapter 4

    Science.gov (United States)

    Rob Hubbard; Michael Battaglia; Chuck Rhoades; Jim Thinnes; Tom Martin; Jeff Underhill; Mark Westfahl

    2014-01-01

    More than 23 million acres of lodgepole pine forests across the western U.S. have experienced overstory mortality following the recent mountain pine beetle (MPB) epidemic (USDA Forest Service 2013). Unknowns regarding the immediate and long-term consequences of the epidemic challenge the ability of managers to make informed decisions aimed at sustaining forest health...

  5. The origin and emergence of an HIV-1 epidemic:

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne; Audelin, Anne M.; Helleberg, Marie

    2014-01-01

    To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic.......To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic....

  6. Monitoring epidemic alert levels by analyzing Internet search volume.

    Science.gov (United States)

    Zhou, Xichuan; Li, Qin; Zhu, Zhenglin; Zhao, Han; Tang, Hao; Feng, Yujie

    2013-02-01

    The prevention of infectious diseases is a global health priority area. The early detection of possible epidemics is the first and important defense line against infectious diseases. However, conventional surveillance systems, e.g., the Centers for Disease Control and Prevention (CDC), rely on clinical data. The CDC publishes the surveillance results weeks after epidemic outbreaks. To improve the early detection of epidemic outbreaks, we designed a syndromic surveillance system to predict the epidemic trends based on disease-related Google search volume. Specifically, we first represented the epidemic trend with multiple alert levels to reduce the noise level. Then, we predicted the epidemic alert levels using a continuous density HMM, which incorporated the intrinsic characteristic of the disease transmission for alert level estimation. Respective models are built to monitor both national and regional epidemic alert levels of the U.S. The proposed system can provide real-time surveillance results, which are weeks before the CDC's reports. This paper focusses on monitoring the infectious disease in the U.S., however, we believe similar approach may be used to monitor epidemics for the developing countries as well.

  7. An information strategy for the epidemic control chain

    NARCIS (Netherlands)

    Visser, T.; Dijkman, J.J.; Grijpink, J.H.A.M.|info:eu-repo/dai/nl/095130861; Plomp, M.G.A.|info:eu-repo/dai/nl/313946809; Seignette, P.

    2011-01-01

    This article presents the results of the chain analysis of the epidemic control chain according to the method of chain-computerisation. The goal of the epidemic control chain is to prevent the disruption of society that is caused by disease or excess of preventive measures. The current

  8. The South African HIV epidemic, reflected by nine provincial ...

    African Journals Online (AJOL)

    A major deflection from the exponential growth patterns seen hitherto can be anticipated only once all or most of the highly populated provinces have traversed their respective points of inflection. The exponential model significantly explains the HIV epidemics in the provinces. The combination of these provincial epidemics ...

  9. Epidemic cerebrospinal meningitis in children at Federal Medical ...

    African Journals Online (AJOL)

    Epidemic meningococcal meningitis is a major public health problem still affecting tropical countries, particularly in Sub-Saharan Africa, which lies within African meningitis belt. Repeated large scale epidemics of CSM have been reported in northern Nigeria for the past four decades. It is one of the important causes of ...

  10. The cholera epidemic in South Africa, 1980 - 1987 Epidemiological ...

    African Journals Online (AJOL)

    During the cholera epidemic in South Africa, 1980-1987, 25251 cases of cholera were bacteriologically proven. The case-fatality rate was 1,4%. Outbreaks occurred in the summer rainfall season. Age-specific aUack rates followed the pattern typically found during the 'epidemic phase' of the disease in most years. The vast ...

  11. The cholera epidemic in South Africa, 1980 - 1987

    African Journals Online (AJOL)

    1991-05-04

    May 4, 1991 ... During the cholera epidemic in South Africa, 1980-1987,. 25251 cases of cholera were bacteriologically proven. The case-fatality rate was 1,4%. Outbreaks occurred in the summer rainfall season. Age-specific aUack rates followed the pattern typically found during the 'epidemic phase' of the disease in.

  12. The chemical bases of the various AIDS epidemics: recreational ...

    Indian Academy of Sciences (India)

    Why is there no vaccine against AIDS? Why is AIDS in the US and Europe not random like other viral epidemics? Why did AIDS not rise and then decline exponentially owing to antiviral immunity like all other viral epidemics? Why is AIDS not contagious? Why would only HIV carriers get AIDS who use either recreational or ...

  13. Evolutionary pathway to increased virulence and epidemic group A Streptococcus disease derived from 3,615 genome sequences

    Science.gov (United States)

    Nasser, Waleed; Beres, Stephen B.; Olsen, Randall J.; Dean, Melissa A.; Rice, Kelsey A.; Long, S. Wesley; Kristinsson, Karl G.; Gottfredsson, Magnus; Vuopio, Jaana; Raisanen, Kati; Caugant, Dominique A.; Steinbakk, Martin; Low, Donald E.; McGeer, Allison; Darenberg, Jessica; Henriques-Normark, Birgitta; Van Beneden, Chris A.; Hoffmann, Steen; Musser, James M.

    2014-01-01

    We sequenced the genomes of 3,615 strains of serotype Emm protein 1 (M1) group A Streptococcus to unravel the nature and timing of molecular events contributing to the emergence, dissemination, and genetic diversification of an unusually virulent clone that now causes epidemic human infections worldwide. We discovered that the contemporary epidemic clone emerged in stepwise fashion from a precursor cell that first contained the phage encoding an extracellular DNase virulence factor (streptococcal DNase D2, SdaD2) and subsequently acquired the phage encoding the SpeA1 variant of the streptococcal pyrogenic exotoxin A superantigen. The SpeA2 toxin variant evolved from SpeA1 by a single-nucleotide change in the M1 progenitor strain before acquisition by horizontal gene transfer of a large chromosomal region encoding secreted toxins NAD+-glycohydrolase and streptolysin O. Acquisition of this 36-kb region in the early 1980s into just one cell containing the phage-encoded sdaD2 and speA2 genes was the final major molecular event preceding the emergence and rapid intercontinental spread of the contemporary epidemic clone. Thus, we resolve a decades-old controversy about the type and sequence of genomic alterations that produced this explosive epidemic. Analysis of comprehensive, population-based contemporary invasive strains from seven countries identified strong patterns of temporal population structure. Compared with a preepidemic reference strain, the contemporary clone is significantly more virulent in nonhuman primate models of pharyngitis and necrotizing fasciitis. A key finding is that the molecular evolutionary events transpiring in just one bacterial cell ultimately have produced millions of human infections worldwide. PMID:24733896

  14. Disease Occurrence - Worldwide, July - December 1983. Compilation of Unclasssified Articles.

    Science.gov (United States)

    1983-12-01

    soldiers patroling border areas, and the indigenous Orang Asli (many of whom are asymtomatic carriers). In the 10-year period prior to 1982, government...from Tokyo this year, all imported. MALAYSIA July - Cholera, previously reported from Sabah and Perak Provinces (DST-1810S-001-83 RPT 6) has occurred...The cholera epidemic continues in Malaysia . By 5 September 1983, 443 confirmed and 651 suspected cases had been recorded. December - The Trengganu

  15. Predicting life history parameters for all fishes worldwide.

    Science.gov (United States)

    Thorson, James T; Munch, Stephan B; Cope, Jason M; Gao, Jin

    2017-12-01

    Scientists and resource managers need to know life history parameters (e.g., average mortality rate, individual growth rate, maximum length or mass, and timing of maturity) to understand and respond to risks to natural populations and ecosystems. For over 100 years, scientists have identified "life history invariants" (LHI) representing pairs of parameters whose ratio is theorized to be constant across species. LHI then promise to allow prediction of many parameters from field measurements of a few important traits. Using LHI in this way, however, neglects any residual patterns in parameters when making predictions. We therefore apply a multivariate model for eight variables (seven parameters and temperature) in over 32,000 fishes, and include taxonomic structure for residuals (with levels for class, order, family, genus, and species). We illustrate that this approach predicts variables probabilistically for taxa with many or few data. We then use this model to resolve three questions regarding life history parameters in fishes. Specifically we show that (1) on average there is a 1.24% decrease in the Brody growth coefficient for every 1% increase in maximum size; (2) the ratio of natural mortality rate and growth coefficient is not an LHI but instead varies systematically based on the timing of maturation, where movement along this life history axis is predictably correlated with species taxonomy; and (3) three variables must be known per species to precisely predict remaining life history variables. We distribute our predictive model as an R package, FishLife, to allow future life history predictions for fishes to be conditioned on taxonomy and life history data for fishes worldwide. This package also contains predictions (and predictive intervals) for mortality, maturity, size, and growth parameters for all described fishes. © 2017 by the Ecological Society of America.

  16. Risks from Worldwide Terrorism: Mortality and Morbidity Patterns and Trends

    Energy Technology Data Exchange (ETDEWEB)

    Bogen, K T; Jones, E D

    2005-01-25

    Worldwide data on terrorist incidents between 1968 and 2004 gathered by the RAND corporation and the Oklahoma City National Memorial Institute for the Prevention of Terrorism (MIPT) were assessed for patterns and trends in morbidity/mortality. The data involve a total of 19,828 events, 7,401 ''adverse'' events (each causing {ge}1 victim), 91,346 cases of casualty (either injury or death) and 25,408 deaths. Analyses revealed a number of interesting patterns and apparently significant trends. Most terror-related adverse events, casualties and deaths involved bombs and guns. Weapon-specific patterns and terror-related risk levels in Israel (ISR) have differed markedly from those of all other regions combined (AOR). ISR had a fatal fraction of casualties about half that of AOR, but has experienced relatively constant lifetime terror-related casualty risks on the order of 0.5%--a level 2 to 3 orders of magnitude more than those experienced in AOR, which have increased {approx}100-fold over the same period. Individual event fatality has increased steadily, the median increasing from 14 to 50%. Lorenz curves obtained indicate substantial dispersion among victim/event rates: about half of all victims were caused by the top 2% (10%) of harm-ranked events in OAR (ISR). Extreme values of victim/event rates were found to be well modeled by classic or generalized Pareto distributions, indicating that these rates have been as predictable as similarly extreme phenomena such as rainfall, sea levels, earthquakes, etc. This observation suggests that these extreme-value patterns may be used to improve strategies to prevent and manage risks associated with terror-related consequences.

  17. Historical Epidemics Cartography Generated by Spatial Analysis: Mapping the Heterogeneity of Three Medieval "Plagues" in Dijon.

    Science.gov (United States)

    Galanaud, Pierre; Galanaud, Anne; Giraudoux, Patrick

    2015-01-01

    This work was designed to adapt Geographical Information System-based spatial analysis to the study of historical epidemics. We mapped "plague" deaths during three epidemics of the early 15th century, analyzed spatial distributions by applying the Kulldorff's method, and determined their relationships with the distribution of socio-professional categories in the city of Dijon. Our study was based on a database including 50 annual tax registers (established from 1376 to 1447) indicating deaths and survivors among the heads of households, their home location, tax level and profession. The households of the deceased and survivors during 6 years with excess mortality were individually located on a georeferenced medieval map, established by taking advantage of the preserved geography of the historical center of Dijon. We searched for clusters of heads of households characterized by shared tax levels (high-tax payers, the upper decile; low-tax payers, the half charged at the minimum level) or professional activities and for clusters of differential mortality. High-tax payers were preferentially in the northern intramural part, as well as most wealthy or specialized professionals, whereas low-tax payers were preferentially in the southern part. During two epidemics, in 1400-1401 and 1428, areas of higher mortality were found in the northern part whereas areas of lower mortality were in the southern one. A high concentration of housing and the proximity to food stocks were common features of the most affected areas, creating suitable conditions for rats to pullulate. A third epidemic, lasting from 1438 to 1440 had a different and evolving geography: cases were initially concentrated around the southern gate, at the confluence of three rivers, they were then diffuse, and ended with residual foci of deaths in the northern suburb. Using a selected historical source, we designed an approach allowing spatial analysis of urban medieval epidemics. Our results fit with the view

  18. Historical Epidemics Cartography Generated by Spatial Analysis: Mapping the Heterogeneity of Three Medieval "Plagues" in Dijon.

    Directory of Open Access Journals (Sweden)

    Pierre Galanaud

    Full Text Available This work was designed to adapt Geographical Information System-based spatial analysis to the study of historical epidemics. We mapped "plague" deaths during three epidemics of the early 15th century, analyzed spatial distributions by applying the Kulldorff's method, and determined their relationships with the distribution of socio-professional categories in the city of Dijon.Our study was based on a database including 50 annual tax registers (established from 1376 to 1447 indicating deaths and survivors among the heads of households, their home location, tax level and profession. The households of the deceased and survivors during 6 years with excess mortality were individually located on a georeferenced medieval map, established by taking advantage of the preserved geography of the historical center of Dijon. We searched for clusters of heads of households characterized by shared tax levels (high-tax payers, the upper decile; low-tax payers, the half charged at the minimum level or professional activities and for clusters of differential mortality.High-tax payers were preferentially in the northern intramural part, as well as most wealthy or specialized professionals, whereas low-tax payers were preferentially in the southern part. During two epidemics, in 1400-1401 and 1428, areas of higher mortality were found in the northern part whereas areas of lower mortality were in the southern one. A high concentration of housing and the proximity to food stocks were common features of the most affected areas, creating suitable conditions for rats to pullulate. A third epidemic, lasting from 1438 to 1440 had a different and evolving geography: cases were initially concentrated around the southern gate, at the confluence of three rivers, they were then diffuse, and ended with residual foci of deaths in the northern suburb.Using a selected historical source, we designed an approach allowing spatial analysis of urban medieval epidemics. Our results fit

  19. Florida's tuberculosis epidemic. Public health response.

    Science.gov (United States)

    Witte, J J; Bigler, W J

    1994-03-01

    Florida ranked fourth in the nation with 1,707 tuberculosis cases reported in 1992 for a rate of 12.7 per 100,000 population. Thirteen percent of these patients had AIDS. Recent cases in prisons, shelters, hospitals and schools have stimulated interest and media coverage. Resurgence of strains of multiple-drug resistant tuberculosis is a serious concern. The Florida Department of Health and Rehabilitative Services, in collaboration with allied agencies, has utilized several initiatives in response. The most significant, Tuberculosis Epidemic Containment Plan, details intervention strategies needed to eliminate TB in the state by the year 2010. Successful implementation depends upon local TB prevention and control coalitions that include private and public sector providers.

  20. Epidemics of Liquidity Shortages in Interbank Markets

    CERN Document Server

    Brandi, Giuseppe; Cimini, Giulio

    2016-01-01

    Financial contagion from liquidity shocks has being recently ascribed as a prominent driver of systemic risk in interbank lending markets. Building on standard compartment models used in epidemics, here we develop an EDB (Exposed-Distressed-Bankrupted) model for the dynamics of liquidity shocks reverberation between banks, and validate it on electronic market for interbank deposits data. We show that the interbank network was highly susceptible to liquidity contagion at the beginning of the 2007/2008 global financial crisis, and that the subsequent micro-prudential and liquidity hoarding policies adopted by banks increased the network resilience to systemic risk, yet with the undesired side effect of drying out liquidity from the market. We finally show that the individual riskiness of a bank is better captured by its network centrality than by its participation to the market, along with the currently debated concept of "too interconnected to fail".

  1. A new epidemic model of computer viruses

    Science.gov (United States)

    Yang, Lu-Xing; Yang, Xiaofan

    2014-06-01

    This paper addresses the epidemiological modeling of computer viruses. By incorporating the effect of removable storage media, considering the possibility of connecting infected computers to the Internet, and removing the conservative restriction on the total number of computers connected to the Internet, a new epidemic model is proposed. Unlike most previous models, the proposed model has no virus-free equilibrium and has a unique endemic equilibrium. With the aid of the theory of asymptotically autonomous systems as well as the generalized Poincare-Bendixson theorem, the endemic equilibrium is shown to be globally asymptotically stable. By analyzing the influence of different system parameters on the steady number of infected computers, a collection of policies is recommended to prohibit the virus prevalence.

  2. Epidemics scenarios in the "Romantic network"

    CERN Document Server

    Carvalho, Alexsandro M

    2012-01-01

    The structure of sexual contacts, its contacts network and its temporal interactions, play an important role in the spread of sexually transmitted infections. Unfortunately, that kind of data is very hard to obtain. One of the few exceptions is the "Romantic network" which is a complete structure of a real sexual network of a high school. In terms of topology, unlike other sexual networks classified as scale-free network. Regarding the temporal structure, several studies indicate that relationship timing can have effects on diffusion through networks, as relationship order determines transmission routes.With the aim to check if the particular structure, static and dynamic, of the Romantic network is determinant for the propagation of an STI in it, we perform simulations in two scenarios: the static network where all contacts are available and the dynamic case where contacts evolve in time. In the static case, we compare the epidemic results in the Romantic network with some paradigmatic topologies. We further...

  3. Epidemic Dynamics in Open Quantum Spin Systems

    Science.gov (United States)

    Pérez-Espigares, Carlos; Marcuzzi, Matteo; Gutiérrez, Ricardo; Lesanovsky, Igor

    2017-10-01

    We explore the nonequilibrium evolution and stationary states of an open many-body system that displays epidemic spreading dynamics in a classical and a quantum regime. Our study is motivated by recent experiments conducted in strongly interacting gases of highly excited Rydberg atoms where the facilitated excitation of Rydberg states competes with radiative decay. These systems approximately implement open quantum versions of models for population dynamics or disease spreading where species can be in a healthy, infected or immune state. We show that in a two-dimensional lattice, depending on the dominance of either classical or quantum effects, the system may display a different kind of nonequilibrium phase transition. We moreover discuss the observability of our findings in laser driven Rydberg gases with particular focus on the role of long-range interactions.

  4. Epidemic spreading on evolving signed networks

    CERN Document Server

    Saeedian, M; Jafari, G R; Kertesz, J

    2016-01-01

    Most studies of disease spreading consider the underlying social network as obtained without the contagion, though epidemic influences peoples willingness to contact others: A friendly contact may be turned to unfriendly to avoid infection. We study the susceptible-infected (SI) disease spreading model on signed networks, in which each edge is associated with a positive or negative sign representing the friendly or unfriendly relation between its end nodes. In a signed network, according to Heiders theory, edge signs evolve such that finally a state of structural balance is achieved, corresponding to no frustration in physics terms. However, the danger of infection affects the evolution of its edge signs. To describe the coupled problem of the sign evolution and disease spreading, we generalize the notion of structural balance by taking into account the state of the nodes. We introduce an energy function and carry out Monte-Carlo simulations on complete networks to test the energy landscape, where we find loc...

  5. Mutual Feedback Between Epidemic Spreading and Information Diffusion

    CERN Document Server

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

    2015-01-01

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

  6. Estimating the epidemic threshold on networks by deterministic connections

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kezan, E-mail: lkzzr@sohu.com; Zhu, Guanghu [School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004 (China); Fu, Xinchu [Department of Mathematics, Shanghai University, Shanghai 200444 (China); Small, Michael [School of Mathematics and Statistics, The University of Western Australia, Crawley, Western Australia 6009 (Australia)

    2014-12-15

    For many epidemic networks some connections between nodes are treated as deterministic, while the remainder are random and have different connection probabilities. By applying spectral analysis to several constructed models, we find that one can estimate the epidemic thresholds of these networks by investigating information from only the deterministic connections. Nonetheless, in these models, generic nonuniform stochastic connections and heterogeneous community structure are also considered. The estimation of epidemic thresholds is achieved via inequalities with upper and lower bounds, which are found to be in very good agreement with numerical simulations. Since these deterministic connections are easier to detect than those stochastic connections, this work provides a feasible and effective method to estimate the epidemic thresholds in real epidemic networks.

  7. Concurrency-Induced Transitions in Epidemic Dynamics on Temporal Networks

    Science.gov (United States)

    Onaga, Tomokatsu; Gleeson, James P.; Masuda, Naoki

    2017-09-01

    Social contact networks underlying epidemic processes in humans and animals are highly dynamic. The spreading of infections on such temporal networks can differ dramatically from spreading on static networks. We theoretically investigate the effects of concurrency, the number of neighbors that a node has at a given time point, on the epidemic threshold in the stochastic susceptible-infected-susceptible dynamics on temporal network models. We show that network dynamics can suppress epidemics (i.e., yield a higher epidemic threshold) when the node's concurrency is low, but can also enhance epidemics when the concurrency is high. We analytically determine different phases of this concurrency-induced transition, and confirm our results with numerical simulations.

  8. Front dynamics in fractional-order epidemic models.

    Science.gov (United States)

    Hanert, Emmanuel; Schumacher, Eva; Deleersnijder, Eric

    2011-06-21

    A number of recent studies suggest that human and animal mobility patterns exhibit scale-free, Lévy-flight dynamics. However, current reaction-diffusion epidemics models do not account for the superdiffusive spread of modern epidemics due to Lévy flights. We have developed a SIR model to simulate the spatial spread of a hypothetical epidemic driven by long-range displacements in the infective and susceptible populations. The model has been obtained by replacing the second-order diffusion operator by a fractional-order operator. Theoretical developments and numerical simulations show that fractional-order diffusion leads to an exponential acceleration of the epidemic's front and a power-law decay of the front's leading tail. Our results indicate the potential of fractional-order reaction-diffusion models to represent modern epidemics. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Human mobility and time spent at destination: Impact on spatial epidemic spreading

    CERN Document Server

    Poletto, Chiara; Colizza, Vittoria

    2013-01-01

    Host mobility plays a fundamental role in the spatial spread of infectious diseases. Previous theoretical works based on the integration of network theory into the metapopulation framework have shown that the heterogeneities that characterize real mobility networks favor the propagation of epidemics. Nevertheless, the studies conducted so far assumed the mobility process to be either Markovian or non-Markovian with a fixed traveling time scale. Available statistics however show that the time spent by travelers at destination is characterized by wide fluctuations, ranging between a single day up to several months. Such varying length of stay crucially affects the chance and duration of mixing events among hosts and may therefore have a strong impact on the spread of an emerging disease. Here, we present an analytical and computational study of epidemic processes on a complex subpopulation network where travelers have memory of their origin and spend a heterogeneously distributed time interval at their destinat...

  10. Growth patterns and scaling laws governing AIDS epidemic in Brazilian cities

    CERN Document Server

    Antonio, F J; Teixeira, J J V; Mendes, R S

    2014-01-01

    Brazil holds approximately 1/3 of population living infected with AIDS (acquired immunodeficiency syndrome) in Central and South Americas, and it was also the first developing country to implement a large-scale control and intervention program against AIDS epidemic. In this scenario, we investigate the temporal evolution and current status of the AIDS epidemic in Brazil. Specifically, we analyze records of annual absolute frequency of cases for more than 5000 cities for the first 33 years of the infection in Brazil. We found that (i) the annual absolute frequencies exhibit a logistic-type growth with an exponential regime in the first few years of the AIDS spreading; (ii) the actual reproduction number decaying as a power law; (iii) the distribution of the annual absolute frequencies among cities decays with a power law behavior; (iv) the annual absolute frequencies and the number of inhabitants have an allometric relationship; (v) the temporal evolution of the annual absolute frequencies have different profi...

  11. Epidemic modeling in metapopulation systems with heterogeneous coupling pattern: theory and simulations

    CERN Document Server

    Colizza, Vittoria

    2007-01-01

    The spatial structure of populations is a key element in the understanding of the large scale spreading of epidemics. Motivated by the recent empirical evidence on the heterogeneous properties of transportation and commuting patterns among urban areas, we present a thorough analysis of the behavior of infectious diseases in metapopulation models characterized by heterogeneous connectivity and mobility patterns. We derive the basic reaction-diffusion equation describing the metapopulation system at the mechanistic level and derive an early stage dynamics approximation for the subpopulation invasion dynamics. The analytical description uses degree block variables that allows us to take into account arbitrary degree distribution of the metapopulation network. We show that along with the usual single population epidemic threshold the metapopulation network exhibits a global threshold for the subpopulation invasion. We find an explicit analytic expression for the invasion threshold that determines the minimum numb...

  12. Simulation of the influence of Danish cattle markets on a Foot-and-Mouth epidemic

    DEFF Research Database (Denmark)

    Boklund, Anette; Lastein, D. B.; Hisham Beshara Halasa, Tariq

    During the epidemic of Foot-and-Mouth disease (FMD) in the United Kingdom in 2001, live animal markets had large influence on the spread of the disease. The culture of and behavior around markets are expected to be different between countries. During the last decade, the number of animals traded...... through markets in Denmark has decreased and only few cattle markets are left. The purpose of this study was to investigate, whether cattle markets would influence the duration, size and economic consequences of a potential FMD epidemic in Denmark. The spread of FMD was simulated using the stochastic...... as a normal distribution with a mean of 0.415 and a standard deviation of 0.06. This probability was a combination of the risk from purchase of animals from markets and the indirect contact from visitors on markets. Danish markets would be closed as soon as FMD is detected. Therefore, markets were only active...

  13. [Effect of major epidemics on cultural awareness].

    Science.gov (United States)

    Spitzy, K H

    1995-01-01

    Mankind has been stricken with "major" epidemic diseases throughout its history. The most serious among them immediately threaten man's life e.g. plague, cholera, smallpox, typhus, and dysentery, besides, there are others which take a slower course e.g. lues, leprosy, leishmaniasis, tuberculosis, and malaria. Yet, the "lesser" epidemic diseases like diphtheria, scarlet fever, mumps, pneumococcosis, influenza, and most recently AIDS may also turn into "major" ones. Originally, man exclusively depended on his genetic makeup for protection, and being particularly prone to attacks of disease he was subject to natural selection. Thus, only one human species survived, the homo sapiens. Interbreeding achieved biologic adaptation and created a balanced genetic polymorphism. Advancing in his degree of civilization, man formed groups, developed clothing, fire, houses, and tools, and his increasing cultural awareness allowed him to migrate from the tropical climates to more temperate, and less disease-infested zones. Immigration and wars, and the accompanying infections jeopardized and diminished entire populations and eradicated highly developed cultures like that of the American Indians. The plague, coming from Asia, and lues, from America, as well as cholera, influenza, and smallpox spread around the whole globe. Fear and terror led to irrational conclusions and triggered persecutions. The attitude of accepting disease as a God-sent fate (Hiob), or a God-sent punishment suppressed reasonable measures against disease. The necessary official measures have increasingly restricted liberty, and this patronizing treatment needs to be opposed with a higher sense of responsibility. Medical art has developed from more healing towards prophylactic and predictive medicine, which prognosticates the individual susceptibility to particular infections, and other risk factors.

  14. Genetic susceptibility, evolution and the kuru epidemic.

    Science.gov (United States)

    Mead, Simon; Whitfield, Jerome; Poulter, Mark; Shah, Paresh; Uphill, James; Beck, Jonathan; Campbell, Tracy; Al-Dujaily, Huda; Hummerich, Holger; Alpers, Michael P; Collinge, John

    2008-11-27

    The acquired prion disease kuru was restricted to the Fore and neighbouring linguistic groups of the Papua New Guinea highlands and largely affected children and adult women. Oral history documents the onset of the epidemic in the early twentieth century, followed by a peak in the mid-twentieth century and subsequently a well-documented decline in frequency. In the context of these strong associations (gender, region and time), we have considered the genetic factors associated with susceptibility and resistance to kuru. Heterozygosity at codon 129 of the human prion protein gene (PRNP) is known to confer relative resistance to both sporadic and acquired prion diseases. In kuru, heterozygosity is associated with older patients and longer incubation times. Elderly survivors of the kuru epidemic, who had multiple exposures at mortuary feasts, are predominantly PRNP codon 129 heterozygotes and this group show marked Hardy-Weinberg disequilibrium. The deviation from Hardy-Weinberg equilibrium is most marked in elderly women, but is also significant in a slightly younger cohort of men, consistent with their exposure to kuru as boys. Young Fore and the elderly from populations with no history of kuru show Hardy-Weinberg equilibrium. An increasing cline in 129V allele frequency centres on the kuru region, consistent with the effect of selection in elevating the frequency of resistant genotypes in the exposed population. The genetic data are thus strikingly correlated with exposure. Considering the strong coding sequence conservation of primate prion protein genes, the number of global coding polymorphisms in man is surprising. By intronic resequencing in a European population, we have shown that haplotype diversity at PRNP comprises two major and divergent clades associated with 129M and 129V. Kuru may have imposed the strongest episode of recent human balancing selection, which may not have been an isolated episode in human history.

  15. Coastal Staphylinidae (Coleoptera): A worldwide checklist, biogeography and natural history

    Science.gov (United States)

    Frank, J. H.; Ahn, Kee-Jeong

    2011-01-01

    Abstract We provide a list of the 392 described species of Staphylinidae confined to coastal habitats worldwide. The list is in taxonomic sequence by subfamily, tribe, and genus and includes 91 genera. We provide the page reference of the original description of every species and genus listed and of many synonyms. We note the existence of recent reviews, phylogenies and keys of each of the tribes and genera included. Coastal Staphylinidae contain eight subfamilies: Microsilphinae, Omaliinae, Pselaphinae, Aleocharinae, Oxytelinae, Scydmaeninae, Paederinae, and Staphylininae. By ‘coastal habitats’ we mean habitats existing on the sea coast and subject to inundation or at least splashing by the very highest tides. This includes rocky, boulder, coral, sandy, and muddy seashores, and at least portions of salt-marshes, estuaries, and mangrove swamps. We exclude the sand dune habitat and higher parts of sea-cliffs. The list notes distribution of all the species, first according to the ocean or sea on whose shores it has been recorded, and second by country (and for the larger countries by province or state). Although this distribution is undoubtedly incomplete, it provides a basis for future development of a dedicated database. The ‘Habitats, Habits, and Classificatory Notes’ section is designed to provide ecologists with further taxonomic and ecological information. It includes references to descriptions of the immature stages, behavior of adults and immatures, their food, natural enemies, and habitat. We would have preferred to separate these entities, but current knowledge of ecology is developed in few instances beyond natural history. The Pacific Ocean basin was the origin and contributed to the dispersal of the majority of specialist coastal Staphylinidae at the level of genus. However, at the level of species, species belonging to non-coastal-specialist genera are about as likely to occur on the shores of other oceans as on the shores of the Pacific. This

  16. Coastal Staphylinidae (Coleoptera: A worldwide checklist, biogeography and natural history

    Directory of Open Access Journals (Sweden)

    Kee-Jeong Ahn

    2011-06-01

    Full Text Available We provide a list of the 392 described species of Staphylinidae confined to coastal habitats worldwide. The list is in taxonomic sequence by subfamily, tribe, and genus and includes 91 genera. We provide the page reference of the original description of every species and genus listed and of many synonyms. We note the existence of recent reviews, phylogenies and keys of each of the tribes and genera included. Coastal Staphylinidae contain eight subfamilies: Microsilphinae, Omaliinae, Pselaphinae, Aleocharinae, Oxytelinae, Scydmaeninae, Paederinae, and Staphylininae. By ‘coastal habitats’ we mean habitats existing on the sea coast and subject to inundation or at least splashing by the very highest tides. This includes rocky, boulder, coral, sandy, and muddy seashores, and at least portions of salt-marshes, estuaries, and mangrove swamps. We exclude the sand dune habitat and higher parts of sea-cliffs. The list notes distribution of all the species, first according to the ocean or sea on whose shores it has been recorded, and second by country (and for the larger countries by province or state. Although this distribution is undoubtedly incomplete, it provides a basis for future development of a dedicated database. The ‘Habitats, Habits, and Classificatory Notes’ section is designed to provide ecologists with further taxonomic and ecological information. It includes references to descriptions of the immature stages, behavior of adults and immatures, their food, natural enemies, and habitat. We would have preferred to separate these entities, but current knowledge of ecology is developed in few instances beyond natural history. The Pacific Ocean basin was the origin and contributed to the dispersal of the majority of specialist coastal Staphylinidae at the level of genus. However, at the level of species, species belonging to non-coastal-specialist genera are about as likely to occur on the shores of other oceans as on the shores of the

  17. The control of vector-borne disease epidemics.

    Science.gov (United States)

    Hosack, Geoffrey R; Rossignol, Philippe A; van den Driessche, P

    2008-11-07

    The theoretical underpinning of our struggle with vector-borne disease, and still our strongest tool, remains the basic reproduction number, R(0), the measure of long term endemicity. Despite its widespread application, R(0) does not address the dynamics of epidemics in a model that has an endemic equilibrium. We use the concept of reactivity to derive a threshold index for epidemicity, E(0), which gives the maximum number of new infections produced by an infective individual at a disease free equilibrium. This index describes the transitory behavior of disease following a temporary perturbation in prevalence. We demonstrate that if the threshold for epidemicity is surpassed, then an epidemic peak can occur, that is, prevalence can increase further, even when the disease is not endemic and so dies out. The relative influence of parameters on E(0) and R(0) may differ and lead to different strategies for control. We apply this new threshold index for epidemicity to models of vector-borne disease because these models have a long history of mathematical analysis and application. We find that both the transmission efficiency from hosts to vectors and the vector-host ratio may have a stronger effect on epidemicity than endemicity. The duration of the extrinsic incubation period required by the pathogen to transform an infected vector to an infectious vector, however, may have a stronger effect on endemicity than epidemicity. We use the index E(0) to examine how vector behavior affects epidemicity. We find that parasite modified behavior, feeding bias by vectors for infected hosts, and heterogeneous host attractiveness contribute significantly to transitory epidemics. We anticipate that the epidemicity index will lead to a reevaluation of control strategies for vector-borne disease and be applicable to other disease transmission models.

  18. Real-time characterization of partially observed epidemics using surrogate models.

    Energy Technology Data Exchange (ETDEWEB)

    Safta, Cosmin; Ray, Jaideep; Lefantzi, Sophia; Crary, David (Applied Research Associates, Arlington, VA); Sargsyan, Khachik; Cheng, Karen (Applied Research Associates, Arlington, VA)

    2011-09-01

    We present a statistical method, predicated on the use of surrogate models, for the 'real-time' characterization of partially observed epidemics. Observations consist of counts of symptomatic patients, diagnosed with the disease, that may be available in the early epoch of an ongoing outbreak. Characterization, in this context, refers to estimation of epidemiological parameters that can be used to provide short-term forecasts of the ongoing epidemic, as well as to provide gross information on the dynamics of the etiologic agent in the affected population e.g., the time-dependent infection rate. The characterization problem is formulated as a Bayesian inverse problem, and epidemiological parameters are estimated as distributions using a Markov chain Monte Carlo (MCMC) method, thus quantifying the uncertainty in the estimates. In some cases, the inverse problem can be computationally expensive, primarily due to the epidemic simulator used inside the inversion algorithm. We present a method, based on replacing the epidemiological model with computationally inexpensive surrogates, that can reduce the computational time to minutes, without a significant loss of accuracy. The surrogates are created by projecting the output of an epidemiological model on a set of polynomial chaos bases; thereafter, computations involving the surrogate model reduce to evaluations of a polynomial. We find that the epidemic characterizations obtained with the surrogate models is very close to that obtained with the original model. We also find that the number of projections required to construct a surrogate model is O(10)-O(10{sup 2}) less than the number of samples required by the MCMC to construct a stationary posterior distribution; thus, depending upon the epidemiological models in question, it may be possible to omit the offline creation and caching of surrogate models, prior to their use in an inverse problem. The technique is demonstrated on synthetic data as well as

  19. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008

    National Research Council Canada - National Science Library

    Ferlay, Jacques; Shin, Hai-Rim; Bray, Freddie; Forman, David; Mathers, Colin; Parkin, Donald Maxwell

    2010-01-01

    Estimates of the worldwide incidence and mortality from 27 cancers in 2008 have been prepared for 182 countries as part of the GLOBOCAN series published by the International Agency for Research on Cancer...

  20. Worldwide research productivity on tramadol: a bibliometric analysis

    OpenAIRE

    Sweileh, Waleed M; Shraim, Naser Y.; Zyoud, Sa?ed H; Al-Jabi, Samah W.

    2016-01-01

    Background Pain management and safe use of analgesics is an important medical issue. Tramadol is an old analgesic with controversial properties. Evaluation of worldwide scientific output on tramadol has not been explored. Therefore, the main objective of this study was to give a bibliometric overview of global research productivity on tramadol. Methods SciVerse Scopus was used to retrieve and quantitatively and qualitatively analyze worldwide publications on tramadol. Results A total of 2059 ...

  1. Epidemic dengue hemorrhagic fever in rural Indonesia. II. Clinical studies.

    Science.gov (United States)

    Eram, S; Setyabudi, Y; Sadono, T I; Sutrisno, D S; Gubler, D J; Sulianti Saroso, J

    1979-07-01

    Clinical observations were made on 95 serologically or virologically confirmed dengue fever cases during an epidemic in a rural area of Indonesia in December 1976. The age distribution was similar to that observed in patients with dengue hemorrhagic fever in Jakarta, a highly endemic urban area. The observed disease ranged in severity from undifferentiated fever to shock and death. The majority of patients had acute onset of fever with nausea, vomiting, headache, and abdominal pain. Hepatomegaly was observed in only 19% of the patients. A positive tourniquet test was the most frequently observed hemorrhagic manifestation, but epistaxis was observed in 20% and hematemesis in 6% of the patients. Dengue shock syndrome was observed in 37% of the patients. There were four deaths, three of which were confirmed as due to dengue infection by virus isolation. The data suggest that one, and possibly two, of the fatal cases with virus isolation were primary infections, based on the results of hemagglutination-inhibition test using all four dengue antigens.

  2. Epidemic polyarthritis (Ross River) virus infection in the Cook Islands.

    Science.gov (United States)

    Rosen, L; Gubler, D J; Bennett, P H

    1981-11-01

    An epidemic of Ross River virus infection occurred in the Cook Islands early in 1980 and affected the majority of the inhabitants of Rarotonga, the most populated island in the group. This represents the easternmost extension of the virus which, until 1979, was believed limited to Australia, New Guinea, and the Solomon Islands. The clinical manifestations of Ross River disease, predominantly polyarthritis, did not differ significantly from those observed previously in Australia. However, unlike the experience in Australia, where Ross River virus has never been isolated from a patient with polyarthritis, the agent was recovered from the serum of one-half of approximately 100 such patients with serologically proven infections. It is not known if this latter observation is the result of a change in the virus, the different virus isolation technique employed, or other factors. It was found that the incubation period of the disease could be as short as 3 days--much less than previously suspected. Ross River virus was isolated from six pools of Aedes polynesiensis mosquitoes collected in nature and it appeared that this species was the most probable vector on Rarotonga. In view of the widespread distribution of Ae. polynesiensis on islands, in the eastern Pacific it would not be surprising if Ross River virus occurs in other previously unaffected areas in the future.

  3. Can influenza epidemics be prevented by voluntary vaccination?

    Directory of Open Access Journals (Sweden)

    Raffaele Vardavas

    2007-05-01

    Full Text Available Previous modeling studies have identified the vaccination coverage level necessary for preventing influenza epidemics, but have not shown whether this critical coverage can be reached. Here we use computational modeling to determine, for the first time, whether the critical coverage for influenza can be achieved by voluntary vaccination. We construct a novel individual-level model of human cognition and behavior; individuals are characterized by two biological attributes (memory and adaptability that they use when making vaccination decisions. We couple this model with a population-level model of influenza that includes vaccination dynamics. The coupled models allow individual-level decisions to influence influenza epidemiology and, conversely, influenza epidemiology to influence individual-level decisions. By including the effects of adaptive decision-making within an epidemic model, we can reproduce two essential characteristics of influenza epidemiology: annual variation in epidemic severity and sporadic occurrence of severe epidemics. We suggest that individual-level adaptive decision-making may be an important (previously overlooked causal factor in driving influenza epidemiology. We find that severe epidemics cannot be prevented unless vaccination programs offer incentives. Frequency of severe epidemics could be reduced if programs provide, as an incentive to be vaccinated, several years of free vaccines to individuals who pay for one year of vaccination. Magnitude of epidemic amelioration will be determined by the number of years of free vaccination, an individuals' adaptability in decision-making, and their memory. This type of incentive program could control epidemics if individuals are very adaptable and have long-term memories. However, incentive-based programs that provide free vaccination for families could increase the frequency of severe epidemics. We conclude that incentive-based vaccination programs are necessary to control

  4. Epidemiology of Thyroid Cancer in an Area of Epidemic Thyroid Goiter

    Directory of Open Access Journals (Sweden)

    Antonio Cossu

    2013-01-01

    Full Text Available The aim of this study was to analyze and describe the epidemiological characteristics and trends of thyroid cancer in the province of Sassari (Sardinia, Italy, an area with epidemic thyroid goiter, in the period 1992–2010. Data were obtained from the local tumor registry which makes part of a wider registry web, coordinated today by the Italian Association for Tumor Registries. An increasing trend in the incidence of thyroid cancer in the province of Sassari was evidenced. This trend seems to follow the general worldwide trend and does not seem to be related to the high incidence of thyroid goiter in the area. The frequencies of the different histological subtypes were similar to those reported in numerous national and international reports. Women are affected earlier than men and, therefore, suffer greater professional, economic, and social impacts. Overall mortality is low and a relative 5-year survival is excellent, especially in comparison to other malignancies.

  5. Carbapenemase-producing Gram-negative bacteria: current epidemics, antimicrobial susceptibility and treatment options.

    Science.gov (United States)

    Jean, Shio-Shin; Lee, Wen-Sen; Lam, Carlos; Hsu, Chin-Wang; Chen, Ray-Jade; Hsueh, Po-Ren

    2015-01-01

    Carbapenemases, with versatile hydrolytic capacity against β-lactams, are now an important cause of resistance of Gram-negative bacteria. The genes encoding for the acquired carbapenemases are associated with a high potential for dissemination. In addition, infections due to Gram-negative bacteria with acquired carbapenemase production would lead to high clinical mortality rates. Of the acquired carbapenemases, Klebsiella pneumoniae carbapenemase (Ambler class A), Verona integron-encoded metallo-β-lactamase (Ambler class B), New Delhi metallo-β-lactamase (Ambler class B) and many OXA enzymes (OXA-23-like, OXA-24-like, OXA-48-like, OXA-58-like, class D) are considered to be responsible for the worldwide resistance epidemics. As compared with monotherapy with colistin or tigecycline, combination therapy has been shown to effectively lower case-fatality rates. However, development of new antibiotics is crucial in the present pandrug-resistant era.

  6. A clonal strain of Trichomonas gallinae is the aetiologic agent of an emerging avian epidemic disease.

    Science.gov (United States)

    Lawson, Becki; Cunningham, Andrew A; Chantrey, Julian; Hughes, Laura A; John, Shinto K; Bunbury, Nancy; Bell, Diana J; Tyler, Kevin M

    2011-10-01

    Trichomonas gallinae is a protozoan parasite that is well characterised as a cause of trichomonosis in columbid and raptor species world-wide. The parasite emerged as a novel infection of British passerines in 2005, leading to epidemic mortality associated with significant declines of breeding populations of greenfinches (Carduelis chloris) and chaffinches (Fringilla coelebs). We characterised the extent of T. gallinae genotypic heterogeneity within the affected wild British avifauna by analysing individual isolates from 17 of the species affected. To do so, we employed improved platform-based multilocus typing tools as well as the hydrogenosomal Fe-hydrogenase gene as a single marker locus for fine-typing. We found no evidence of heterogeneity amongst the parasites infecting British passerines, indicating that a clonal strain of T. gallinae is the causative agent of this emerging infectious disease. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Alzheimer Disease and Its Growing Epidemic: Risk Factors, Biomarkers, and the Urgent Need for Therapeutics.

    Science.gov (United States)

    Hickman, Richard A; Faustin, Arline; Wisniewski, Thomas

    2016-11-01

    Alzheimer disease (AD) represents one of the greatest medical challenges of this century; the condition is becoming increasingly prevalent worldwide and no effective treatments have been developed for this terminal disease. Because the disease manifests at a late stage after a long period of clinically silent neurodegeneration, knowledge of the modifiable risk factors and the implementation of biomarkers is crucial in the primary prevention of the disease and presymptomatic detection of AD, respectively. This article discusses the growing epidemic of AD and antecedent risk factors in the disease process. Disease biomarkers are discussed, and the implications that this may have for the treatment of this currently incurable disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The gin epidemic: much ado about what?

    Science.gov (United States)

    Abel, E L

    2001-01-01

    While there is no doubt that the era of the 'gin epidemic' was associated with poverty and social unrest, the surge in gin drinking was localized to London and was a concomitant, not the cause, of these problems. The two main underlying social problems were widespread overcrowding and poverty. The former was related to an unprecedented migration of people from the country to London. The latter stemmed from an economic ideology called 'poverty theory', whose basic premise was that, by keeping the 'inferior order' in poverty, English goods would be competitive and would remain that way since workers would be completely dependent on their employers. Widespread overcrowding and poverty led to societal unrest which manifested itself in increased drunkenness when cheap gin became available after Parliament did away with former distilling monopolies that had kept prices high. Reformers ignored the social causes of this unrest and, instead, focused on gin drinking by the poor which they feared was endangering England's wealth and security by enfeebling its labour force, and reducing its manpower by decreasing its population. Part of this hostility was also related to gin itself. While drunkenness was often spoken of affectionately when it was induced by beer, England's national drink, gin was considered a foreign drink, and therefore less acceptable. These concerns were voiced less often after the passage of the Tippling Act of 1751, which resulted in an increase in gin prices and decreased consumption. However, the second half of the century was also a period in which England's military victory over the French gave it new wealth and power, which dispelled upper-class fears about an enfeebled and dissolute working class. It was also an era when new public health measures, such as mass inoculation against smallpox, and a decrease in the marrying age, led to a population increase that dispelled reformist fears about manpower shortages. The conclusion is that, while the lower

  9. The epidemic of HIV/AIDS in developing countries; the current scenario in Pakistan.

    Science.gov (United States)

    Yousaf, Muhammad Z; Zia, Sadia; Babar, Masroor E; Ashfaq, Usman A

    2011-08-12

    HIV (Human Immunodeficiency virus) causes (acquired immunodeficiency syndrome) AIDS, in which the immune system of body totally fails to develop any defense against the foreign invaders. Infection with HIV occurs by transfer of blood, semen, and breast milk. HIV/AIDS is a global problem and it results nearly 25 million deaths worldwide. Developing countries like Pakistan have issues regarding Public Health. Currently, epidemic of HIV/AIDS is established in Pakistan and there is a threat of an expanded HIV/AIDS outbreak in the country. The major reason is that population is engaging in high-risk practices, low awareness about HIV/AIDS, and treacherous blood transfusion practices. A supplementary threat to Pakistan is India because both sharing a border and India is facing a rapidly growing HIV/AIDS epidemic. Local NGOs, National and International organizations are warning that in near future Pakistan may experiences bad situation regarding HIV/AIDS.In the present article we focused current situation of surveillance of HIV/AIDS, its virology, genotype, diagnostics, high-risk groups, reasons of vulnerability in Pakistani population, and the role of different national and international organizations in this situation.

  10. The epidemic of HIV/AIDS in developing countries; the current scenario in Pakistan

    Directory of Open Access Journals (Sweden)

    Babar Masroor E

    2011-08-01

    Full Text Available Abstract HIV (Human Immunodeficiency virus causes (acquired immunodeficiency syndrome AIDS, in which the immune system of body totally fails to develop any defense against the foreign invaders. Infection with HIV occurs by transfer of blood, semen, and breast milk. HIV/AIDS is a global problem and it results nearly 25 million deaths worldwide. Developing countries like Pakistan have issues regarding Public Health. Currently, epidemic of HIV/AIDS is established in Pakistan and there is a threat of an expanded HIV/AIDS outbreak in the country. The major reason is that population is engaging in high-risk practices, low awareness about HIV/AIDS, and treacherous blood transfusion practices. A supplementary threat to Pakistan is India because both sharing a border and India is facing a rapidly growing HIV/AIDS epidemic. Local NGOs, National and International organizations are warning that in near future Pakistan may experiences bad situation regarding HIV/AIDS. In the present article we focused current situation of surveillance of HIV/AIDS, its virology, genotype, diagnostics, high-risk groups, reasons of vulnerability in Pakistani population, and the role of different national and international organizations in this situation.

  11. [Molecular subtyping of Salmonella enterica serotype Enteritidis in a post epidemic period].

    Science.gov (United States)

    Ríos R, Mayerling; Araya R, Pamela; Fernández R, Alda; Tognarelli, Javier; Hormazábal, Juan Carlos; Fernández O, Jorge

    2009-01-01

    In the last two decades, Salmonella enterica serotype Enteritidis has become one of the main agents causing food borne diseases worldwide. This agent is transmitted mainly by contaminated meat and poultry. To determine the genetic subtypes of Salmonella enterica serotype Enteritidis, circulating in Chile between 2001 and 2003, a post epidemic period. One hundred ninety three isolates coming from human samples, prepared foods and animal products for human consumption, were analyzed by pulsed field electrophoresis, using PulseNet standardized protocol. Thirteen subtypes of Salmonella enterica serotype Enteritidis were identified, that had between 0 and 13 bands. A predominant subtype was identified in 172 strains (88%) that came from human isolates, prepared foods and animal products for human consumption. Other four subtypes, found in prepared foods and animal products for human consumption, were also found in human isolates. Most subtypes were tightly interrelated Subtypes II, VIII and XI were also found in the 1994 epidemic. Subtyping of bacterial strains by pulsed field electrophoresis is useful for the surveillance of food borne diseases.

  12. Epidemiological and virological features of epidemic keratoconjunctivitis due to new human adenovirus type 54 in Japan.

    Science.gov (United States)

    Kaneko, Hisatoshi; Suzutani, Tatsuo; Aoki, Koki; Kitaichi, Nobuyoshi; Ishida, Susumu; Ishiko, Hiroaki; Ohashi, Tsutomu; Okamoto, Shigeki; Nakagawa, Hisashi; Hinokuma, Rikutaro; Asato, Yoshimori; Oniki, Shinobu; Hashimoto, Teiko; Iida, Tomohiro; Ohno, Shigeaki

    2011-01-01

    New human adenovirus (HAdV)-54 causes epidemic keratoconjunctivitis (EKC) and is virologically close to and has occasionally been detected as HAdV-8. Taking HAdV-54 into account, we re-determined HAdV type in EKC samples to determine its epidemiology in Japan, and examined the virological features of HAdV-54. HAdV type was re-determined in 776 conjunctival swabs from Japan and 174 from six other countries, obtained between 2000 and 2009. Using 115 HAdV strains obtained before 1999, trends regarding HAdV-8 and HAdV-54 were also determined. In addition, immunochromatography (IC) kit features, DNA copy numbers and viral isolation of HAdV-54 in samples were evaluated. Recently, HAdV-37 and HAdV-54 have been the major causative types of EKC in Japan. HAdV-54 has been isolated each year since 1995, whereas HAdV-8 has become less common since 1997, although it remains the most common cause of EKC in the six other countries investigated where HAdV-54 is yet to be detected. HAdV-54 is comparable to other EKC-related HAdV types in terms of IC kit sensitivity and DNA copy numbers, although HAdV-54 grows more slowly on viral isolation. EKC due to HAdV-54 can result in epidemics; therefore, it should be accurately diagnosed and monitored as an emerging infection worldwide.

  13. Worldwide geographical distribution of Black Sigatoka for banana: predictions based on climate change models Distribuição geográfica da Sigatoka Negra da bananeira estimada por modelos de mudanças climáticas globais

    Directory of Open Access Journals (Sweden)

    Waldir Cintra de Jesus Júnior

    2008-12-01

    Full Text Available As mudanças climáticas poderão alterar as doenças de plantas e afetar a eficácia das medidas de manejo. Um dos prováveis impactos será na distribuição geográfica das doenças. A Sigatoka Negra é considerada a principal doença da cultura da banana em decorrência dos danos causados e aumento do custo de manejo. O impacto sócio-econômico da doença continua aumentando, uma vez que a doença tem atingido novas áreas de plantio, tornando o manejo mais difícil. Este trabalho tem por objetivos comparar a distribuição geográfica da doença por meio da elaboração de mapas nas seguintes situações: a clima atual e futuro (2020, 2050 e 2080, b cenários A2 e B2 do Painel Intergovernamental de Mudanças Climáticas, c predito por seis diferentes modelos de mudanças climáticas e pela média dos mesmos e, d entre meses. Haverá redução das áreas favoráveis à doença no futuro, sendo que tal redução será mais acentuada no cenário A2 do que no B2 e gradativa para as décadas de 2020, 2050 e 2080. Predições efetuadas com o uso da média dos dados estimados pelos modelos permitiram redução na variabilidade da simulação em comparação com a predição gerada por cada modelo individualmente. Alterações na distribuição geográfica da doença ocorrerão entre meses, de modo que áreas consideradas desfavoráveis tornar-se-ão favoráveis e vice-versa. Apesar disso, extensas áreas continuarão favoráveis ao desenvolvimento da Sigatoka Negra.Global climatic changes will potentially influence plant diseases and the efficacy of their management options. One of the most likely impacts of climate change will be felt by the geographical distribution of plant diseases. Black Sigatoka is considered the most damaging and costly disease of banana. The socio-economic impact of this disease has continued to increase as the pathogen reaches new areas and the disease becomes more difficult to be controled. The objectives of this

  14. Control of African swine fever epidemics in industrialized swine populations

    DEFF Research Database (Denmark)

    Hisham Beshara Halasa, Tariq; Bøtner, Anette; Mortensen, Sten

    2016-01-01

    and national strategy (Basic), the basic strategy plus pre-emptive depopulation of neighboring swine herds, and intensive surveillance of herds in the control zones, including testing live or dead animals. Virus spread via wild boar was not modelled. Under the basic control strategy, the median epidemic...... resulted in marginal improvements to the control of the epidemics. However, adding testing of dead animals in the protection and surveillance zones was predicted to be the optimal control scenario for an ASF epidemic in industrialized swine populations without contact to wild boar. This optimal scenario...

  15. Effect of worldwide oil price fluctuations on biomass fuel use and child respiratory health: evidence from Guatemala.

    Science.gov (United States)

    Venkataramani, Atheendar S; Fried, Brian J

    2011-09-01

    We examined the effect of worldwide oil price fluctuations on household fuel use and child respiratory health in Guatemala. We regressed measures of household fuel use and child respiratory health on the average worldwide oil price and a rich set of covariates. We leveraged variation in oil prices over the 6-month period of the survey to identify associations between fuel prices, fuel choice, and child respiratory outcomes. A $1 (3.4% point) increase in worldwide fuel prices was associated with a 2.8% point decrease in liquid propane gasoline use (P oil prices and the fuel choice indicators was largest for households in the middle of the income distribution. Fluctuations in worldwide fuel prices affected household fuel use and, consequently, child health. Policies to help households tide over fuel price shocks or reduce pollution from biomass sources would confer positive health benefits. Such policies would be most effective if they targeted both poor and middle-income households.

  16. Heterogeneous network epidemics: real-time growth, variance and extinction of infection.

    Science.gov (United States)

    Ball, Frank; House, Thomas

    2017-09-01

    Recent years have seen a large amount of interest in epidemics on networks as a way of representing the complex structure of contacts capable of spreading infections through the modern human population. The configuration model is a popular choice in theoretical studies since it combines the ability to specify the distribution of the number of contacts (degree) with analytical tractability. Here we consider the early real-time behaviour of the Markovian SIR epidemic model on a configuration model network using a multitype branching process. We find closed-form analytic expressions for the mean and variance of the number of infectious individuals as a function of time and the degree of the initially infected individual(s), and write down a system of differential equations for the probability of extinction by time t that are numerically fast compared to Monte Carlo simulation. We show that these quantities are all sensitive to the degree distribution-in particular we confirm that the mean prevalence of infection depends on the first two moments of the degree distribution and the variance in prevalence depends on the first three moments of the degree distribution. In contrast to most existing analytic approaches, the accuracy of these results does not depend on having a large number of infectious individuals, meaning that in the large population limit they would be asymptotically exact even for one initial infectious individual.

  17. Epidemic Clones” of Listeria monocytogenes Are Widespread and Ancient Clonal Groups

    Science.gov (United States)

    Cantinelli, Thomas; Chenal-Francisque, Viviane; Diancourt, Laure; Frezal, Lise; Leclercq, Alexandre; Wirth, Thierry

    2013-01-01

    The food-borne pathogen Listeria monocytogenes is genetically heterogeneous. Although some clonal groups have been implicated in multiple outbreaks, there is currently no consensus on how “epidemic clones” should be defined. The objectives of this work were to compare the patterns of sequence diversity on two sets of genes that have been widely used to define L. monocytogenes clonal groups: multilocus sequence typing (MLST) and multi-virulence-locus sequence typing (MvLST). Further, we evaluated the diversity within clonal groups by pulsed-field gel electrophoresis (PFGE). Based on 125 isolates of diverse temporal, geographical, and source origins, MLST and MvLST genes (i) had similar patterns of sequence polymorphisms, recombination, and selection, (ii) provided concordant phylogenetic clustering, and (iii) had similar discriminatory power, which was not improved when we combined both data sets. Inclusion of representative strains of previous outbreaks demonstrated the correspondence of epidemic clones with previously recognized MLST clonal complexes. PFGE analysis demonstrated heterogeneity within major clones, most of which were isolated decades before their involvement in outbreaks. We conclude that the “epidemic clone” denominations represent a redundant but largely incomplete nomenclature system for MLST-defined clones, which must be regarded as successful genetic groups that are widely distributed across time and space. PMID:24006010

  18. Growth patterns and scaling laws governing AIDS epidemic in Brazilian cities.

    Science.gov (United States)

    Antonio, Fernando Jose; de Picoli, Sergio; Teixeira, Jorge Juarez Vieira; Mendes, Renio dos Santos

    2014-01-01

    Brazil holds approximately 1/3 of population living infected with AIDS (acquired immunodeficiency syndrome) in Central and South Americas, and it was also the first developing country to implement a large-scale control and intervention program against AIDS epidemic. In this scenario, we investigate the temporal evolution and current status of the AIDS epidemic in Brazil. Specifically, we analyze records of annual absolute frequency of cases for more than 5000 cities for the first 33 years of the infection in Brazil. We found that (i) the annual absolute frequencies exhibit a logistic-type growth with an exponential regime in the first few years of the AIDS spreading; (ii) the actual reproduction number decaying as a power law; (iii) the distribution of the annual absolute frequencies among cities decays with a power law behavior; (iv) the annual absolute frequencies and the number of inhabitants have an allometric relationship; (v) the temporal evolution of the annual absolute frequencies have different profile depending on the average annual absolute frequencies in the cities. These findings yield a general quantitative description of the AIDS infection dynamics in Brazil since the beginning. They also provide clues about the effectiveness of treatment and control programs against the infection, that has had a different impact depending on the number of inhabitants of cities. In this framework, our results give insights into the overall dynamics of AIDS epidemic, which may contribute to select empirically accurate models.

  19. A climate-based spatiotemporal prediction for dengue fever epidemics: a case study in southern Taiwan

    Science.gov (United States)

    Yu, H.-L.; Yang, S.-J.; Lin, Y.-C.

    2012-04-01

    Dengue Fever (DF) has been identified by the World Health organization (WHO) as one of the most serious vector-borne infectious diseases in tropical and sub-tropical areas. DF has been one of the most important epidemics in Taiwan which occur annually especially in southern Taiwan during summer and autumn. Most DF studies have focused mainly on temporal DF patterns and its close association with climatic covariates, whereas few studies have investigated the spatial DF patterns (spatial dependence and clustering) and composite space-time effects of the DF epidemics. The present study proposes a spatio-temporal DF prediction approach based on stochastic Bayesian Maximum Entropy (BME) analysis. Core and site-specific knowledge bases are considered, including climate and health datasets under conditions of uncertainty, space-time dependence functions, and a Poisson regression model of climatic variables contributing to DF occurrences in southern Taiwan during 2007, when the highest number of DF cases was recorded in the history of Taiwan epidemics (over 2000). The obtained results show that the DF outbreaks in the study area are highly influenced by climatic conditions. Furthermore, the analysis can provide the required "one-week-ahead" outbreak warnings based on spatio-temporal predictions of DF distributions. Therefore, the proposed analysis can provide the Taiwan Disease Control Agency with a valuable tool to timely identify, control, and even efficiently prevent DF spreading across space-time.

  20. Impact of the obesity epidemic on cancer.

    Science.gov (United States)

    Goodwin, Pamela J; Stambolic, Vuk

    2015-01-01

    There is growing appreciation that the current obesity epidemic is associated with increases in cancer incidence at a population level and may lead to poor cancer outcomes; concurrent decreases in cancer mortality at a population level may represent a paradox, i.e., they may also reflect improvements in the diagnosis and treatment of cancer that mask obesity effects. An association of obesity with cancer is biologically plausible because adipose tissue is biologically active, secreting estrogens, adipokines, and cytokines. In obesity, adipose tissue reprogramming may lead to insulin resistance, with or without diabetes, and it may contribute to cancer growth and progression locally or through systemic effects. Obesity-associated changes impact cancer in a complex fashion, potentially acting directly on cells through pathways, such as the phosphoinositide 3-kinase (PI3K) and Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathways, or indirectly via changes in the tumor microenvironment. Approaches to obesity management are discussed, and the potential for pharmacologic interventions that target the obesity-cancer link is addressed.

  1. Environmental signatures associated with cholera epidemics.

    Science.gov (United States)

    Constantin de Magny, Guillaume; Murtugudde, Raghu; Sapiano, Mathew R P; Nizam, Azhar; Brown, Christopher W; Busalacchi, Antonio J; Yunus, Mohammad; Nair, G Balakrish; Gil, Ana I; Lanata, Claudio F; Calkins, John; Manna, Byomkesh; Rajendran, Krishnan; Bhattacharya, Mihir Kumar; Huq, Anwar; Sack, R Bradley; Colwell, Rita R

    2008-11-18

    The causative agent of cholera, Vibrio cholerae, has been shown to be autochthonous to riverine, estuarine, and coastal waters along with its host, the copepod, a significant member of the zooplankton community. Temperature, salinity, rainfall and plankton have proven to be important factors in the ecology of V. cholerae, influencing the transmission of the disease in those regions of the world where the human population relies on untreated water as a source of drinking water. In this study, the pattern of cholera outbreaks during 1998-2006 in Kolkata, India, and Matlab, Bangladesh, and the earth observation data were analyzed with the objective of developing a prediction model for cholera. Satellite sensors were used to measure chlorophyll a concentration (CHL) and sea surface temperature (SST). In addition, rainfall data were obtained from both satellite and in situ gauge measurements. From the analyses, a statistically significant relationship between the time series for cholera in Kolkata, India, and CHL and rainfall anomalies was determined. A statistically significant one month lag was observed between CHL anomaly and number of cholera cases in Matlab, Bangladesh. From the results of the study, it is concluded that ocean and climate patterns are useful predictors of cholera epidemics, with the dynamics of endemic cholera being related to climate and/or changes in the aquatic ecosystem. When the ecology of V. cholerae is considered in predictive models, a robust early warning system for cholera in endemic regions of the world can be developed for public health planning and decision making.

  2. Systemic calicivirus epidemic in captive exotic felids.

    Science.gov (United States)

    Harrison, Tara M; Sikarskie, James; Kruger, John; Wise, Annabel; Mullaney, Thomas P; Kiupel, Matti; Maes, Roger K

    2007-06-01

    A 5-day-old, mother-raised, Amur tiger cub (Panthera tigris altaica) presented with tongue ulcerations. Identical lesions appeared and progressed to sloughing of the tongue in the three littermates of this cub the following day. The lesions progressed in all cubs to include sloughing of the carpal, tarsal, metacarpal, and metatarsal foot pad epithelium. Oral ulcerations were also noted in adult African lions (Panthera leo) and Amur tigers (Panthera tigris altaica), but not in two adult snow leopards (Panthera uncia) housed in the same building. All adult cats had been previously vaccinated for common feline diseases including feline calicivirus (FCV). Detection of FCV RNA in oral secretions by a real-time reverse transcription polymerase chain reaction assay (RRT-PCR) confirmed FCV infection in the tiger cubs and one lion. A male lion and a male tiger cub died during the disease outbreak. RRT-PCR confirmed FCV in multiple tissues in both of these animals. A stray cat live-trapped outside the feline building during the epidemic was found to be positive for FCV by virus isolation and was thought to be the source of infection.

  3. Chronic kidney disease epidemic: myth and reality.

    Science.gov (United States)

    Mangione, Filippo; Dal Canton, Antonio

    2011-10-01

    In recent years, an epidemic of chronic kidney disease (CKD) has emerged as one of the major public health problem. The prevalence of CKD is largely sustained by the inclusion of a substantial proportion of the elderly population within stage 3 CKD, according to the Kidney Disease Outcomes Quality Initiative staging system. However, some clarifications are necessary when interpreting these data. In fact, renal function "normally" declines with age, without bearing any unfavourable outcome; in addition, the Modification of Diet in Renal Disease formula used to calculate glomerular filtration rate (GFR) underestimates kidney function in the elderly and in women. Considerable interest in CKD has been generated by the evidence that predialysis CKD is associated with the increased risk of cardiovascular disease (CVD). Again, potential confounding factors must be ruled out. Age is thought to play a major role in this context. The most common causes of CKD, hypertension and diabetes mellitus, are also known to affect cardiovascular outcomes directly, thus preventing the recognition of an independent effect of kidney dysfunction on mortality by CVD. Taken together, these considerations point for a better definition of CKD. Early identification of patients at risk for accelerated decline in renal function is mandatory to plan strategies for screening and preventing CKD and its complications. At present, detection of CKD in the general population requires a multi-dimensional approach that should include the evaluation of clinical risk conditions, evaluation of albuminuria and sequential monitoring of GFR.

  4. Spatially explicit modelling of cholera epidemics

    Science.gov (United States)

    Finger, F.; Bertuzzo, E.; Mari, L.; Knox, A. C.; Gatto, M.; Rinaldo, A.

    2013-12-01

    Epidemiological models can provide crucial understanding about the dynamics of infectious diseases. Possible applications range from real-time forecasting and allocation of health care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. We apply a spatially explicit model to the cholera epidemic that struck Haiti in October 2010 and is still ongoing. The dynamics of susceptibles as well as symptomatic and asymptomatic infectives are modelled at the scale of local human communities. Dissemination of Vibrio cholerae through hydrological transport and human mobility along the road network is explicitly taken into account, as well as the effect of rainfall as a driver of increasing disease incidence. The model is calibrated using a dataset of reported cholera cases. We further model the long term impact of several types of interventions on the disease dynamics by varying parameters appropriately. Key epidemiological mechanisms and parameters which affect the efficiency of treatments such as antibiotics are identified. Our results lead to conclusions about the influence of different intervention strategies on the overall epidemiological dynamics.

  5. The heart failure epidemic: a UK perspective

    Directory of Open Access Journals (Sweden)

    Martin R Cowie

    2017-03-01

    Full Text Available Heart failure is appropriately described as an epidemic, with 1–2% of health care expenditure being directed at its management. In England, the National Institute for Health and Care Excellence (NICE has issued guidance on the best practice for the diagnosis and treatment of acute and chronic heart failure. Echocardiography is key to the diagnosis of the underlying cardiac abnormalities, and access to this (with our without biochemical testing using natriuretic peptides is key to high-quality and speedy diagnosis. New models of care aim to speed up access to echocardiography, but a shortage of technically trained staff remains a limiting factor in improving standards of care. The NHS audits the quality of care and outcome for patients admitted to hospital with heart failure, and this continues to show wide variation in practice, particularly, where patients are not reviewed by the local heart failure multidisciplinary team. Recently, the All Party Parliamentary Group on Cardiac Disease issued 10 suggestions for improvement in care for patients with heart failure – access to echocardiography being one of the key suggestions. Time will tell as to whether this support from law makers will assist in the implementation of NICE-recommended standards of care consistently across the country.

  6. Diabetes mellitus: The epidemic of the century

    Science.gov (United States)

    Kharroubi, Akram T; Darwish, Hisham M

    2015-01-01

    The epidemic nature of diabetes mellitus in different regions is reviewed. The Middle East and North Africa region has the highest prevalence of diabetes in adults (10.9%) whereas, the Western Pacific region has the highest number of adults diagnosed with diabetes and has countries with the highest prevalence of diabetes (37.5%). Different classes of diabetes mellitus, type 1, type 2, gestational diabetes and other types of diabetes mellitus are compared in terms of diagnostic criteria, etiology and genetics. The molecular genetics of diabetes received extensive attention in recent years by many prominent investigators and research groups in the biomedical field. A large array of mutations and single nucleotide polymorphisms in genes that play a role in the various steps and pathways involved in glucose metabolism and the development, control and function of pancreatic cells at various levels are reviewed. The major advances in the molecular understanding of diabetes in relation to the different types of diabetes in comparison to the previous understanding in this field are briefly reviewed here. Despite the accumulation of extensive data at the molecular and cellular levels, the mechanism of diabetes development and complications are still not fully understood. Definitely, more extensive research is needed in this field that will eventually reflect on the ultimate objective to improve diagnoses, therapy and minimize the chance of chronic complications development. PMID:26131326

  7. Epidemic spreading on evolving signed networks

    Science.gov (United States)

    Saeedian, M.; Azimi-Tafreshi, N.; Jafari, G. R.; Kertesz, J.

    2017-02-01

    Most studies of disease spreading consider the underlying social network as obtained without the contagion, though epidemic influences people's willingness to contact others: A "friendly" contact may be turned to "unfriendly" to avoid infection. We study the susceptible-infected disease-spreading model on signed networks, in which each edge is associated with a positive or negative sign representing the friendly or unfriendly relation between its end nodes. In a signed network, according to Heider's theory, edge signs evolve such that finally a state of structural balance is achieved, corresponding to no frustration in physics terms. However, the danger of infection affects the evolution of its edge signs. To describe the coupled problem of the sign evolution and disease spreading, we generalize the notion of structural balance by taking into account the state of the nodes. We introduce an energy function and carry out Monte Carlo simulations on complete networks to test the energy landscape, where we find local minima corresponding to the so-called jammed states. We study the effect of the ratio of initial friendly to unfriendly connections on the propagation of disease. The steady state can be balanced or a jammed state such that a coexistence occurs between susceptible and infected nodes in the system.

  8. The obesity epidemic and its cardiovascular consequences.

    Science.gov (United States)

    Behn, Agnieszka; Ur, Ehud

    2006-07-01

    Obesity has reached global epidemic proportions because of an increasingly obesogenic environment. This review examines the association between obesity, and in particular visceral fat, as a risk factor for cardiovascular disease and mortality. The World Health Organization defines obesity based on the body mass index. Recently the waist-to-hip ratio has been shown to be a significantly stronger predictor of cardiovascular events than body mass index. The metabolic syndrome and its evolving definition represent a cluster of metabolic risk factors which help predict cardiovascular disease and mortality. Although insulin resistance plays a central role in the pathophysiology of the metabolic syndrome, there is limited support for therapy with insulin sensitizers, thiazolidinediones, in patients with coronary artery disease. The current anti-obesity drugs, orlistat and sibutramine, have only a modest effect on weight loss. The blockade of the endocannabinoid system with rimonabant, however, may be a promising new strategy. Obesity is associated with significant increase in cardiovascular risk. Lifestyle modification remains the cornerstone of management although anti-obesity medications may be indicated in high risk individuals with comorbid disease.

  9. Epidemic Impacts of a Community Empowerment Intervention for HIV Prevention among Female Sex Workers in Generalized and Concentrated Epidemics

    Science.gov (United States)

    Wirtz, Andrea L.; Pretorius, Carel; Beyrer, Chris; Baral, Stefan; Decker, Michele R.; Sherman, Susan G.; Sweat, Michael; Poteat, Tonia; Butler, Jennifer; Oelrichs, Robert; Semini, Iris; Kerrigan, Deanna

    2014-01-01

    Introduction Sex workers have endured a high burden of HIV infection in and across HIV epidemics. A comprehensive, community empowerment-based HIV prevention intervention emphasizes sex worker organization and mobilization to address HIV risk and often includes community-led peer education, condom distribution, and other activities. Meta-analysis of such interventions suggests a potential 51% reduction in inconsistent condom use. Mathematical modeling exercises provide theoretical insight into potential impacts of the intervention on HIV incidence and burden in settings where interventions have not yet been implemented. Methods We used a deterministic model, Goals, to project the impact on HIV infections when the community empowerment interventions were scaled up among female sex workers in Kenya, Thailand, Brazil, and Ukraine. Modeling scenarios included expansion of the comprehensive community empowerment-based HIV prevention intervention from baseline coverage over a 5-year period (5–65% in Kenya and Ukraine; 10–70% in Thailand and Brazil), while other interventions were held at baseline levels. A second exercise increased the intervention coverage simultaneously with equitable access to ART for sex workers. Impacts on HIV outcomes among sex workers and adults are observed from 2012–2016 and, compared to status quo when all interventions are held constant. Results Optimistic but feasible coverage (65%–70%) of the intervention demonstrated a range of impacts on HIV: 220 infections averted over 5 yrs. among sex workers in Thailand, 1,830 in Brazil, 2,220 in Ukraine, and 10,800 infections in Kenya. Impacts of the intervention for female sex workers extend to the adult population, cumulatively averting 730 infections in Thailand to 20,700 adult infections in Kenya. Impacts vary by country, influenced by HIV prevalence in risk groups, risk behaviors, intervention use, and population size. Discussion A community empowerment approach to HIV prevention and

  10. Vector Transmission Alone Fails to Explain the Potato Yellow Vein Virus Epidemic among Potato Crops in Colombia.

    Science.gov (United States)

    Cuadros, Diego F; Hernandez, Anngie; Torres, Maria F; Torres, Diana M; Branscum, Adam J; Rincon, Diego F

    2017-01-01

    The potato yellow vein disease, caused by the potato yellow vein virus (PYVV), is a limiting potato disease in northern South America. The virus can be transmitted either by the greenhouse whitefly (GWF), Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), or through vegetative propagules, such as infected tubers. Recently, GWF populations have been spotlighted as one of the main drivers of PYVV re-emergence, and consequently, PYVV management has been predominantly directed toward vector control, which is heavily based on insecticide use. However, the drivers of the PYVV outbreaks as well as the contribution of GWF populations on the spread of PYVV among potato crops are still not completely understood. This study aims to assess the role of the GWF as a driver of the PYVV epidemic in the potato-producing areas in Colombia, one of the countries more severely affected by the PYVV epidemic, and whose geography allows the study of the spatial association between the vector and the disease epidemic across a wide altitude range. The geographical clusters where the PYVV epidemic is concentrated, as well as those of farms affected by the GWF were identified using a novel spatial epidemiology approach. The influence of altitude range on the association between PYVV and T. vaporarioum was also assessed. We found a relatively poor spatial association between PYVV epidemic and the presence of the GWF, especially at altitudes above 3,000 m above mean sea level. Furthermore, GWF populations could only explain a small fraction of the extent of the PYVV epidemic in Colombia. Movement of infected seed tubers might be the main mechanism of dispersion, and could be a key driver for the PYVV infection among potato crops. Agricultural policies focused on improving quality of seed tubers and their appropriate distribution could be the most efficient control intervention against PYVV dispersion.

  11. On Spatially Explicit Models of Cholera Epidemics: Hydrologic controls, environmental drivers, human-mediated transmissions (Invited)

    Science.gov (United States)

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

    2010-12-01

    A recently proposed model for cholera epidemics is examined. The model accounts for local communities of susceptibles and infectives in a spatially explicit arrangement of nodes linked by networks having different topologies. The vehicle of infection (Vibrio cholerae) is transported through the network links which are thought of as hydrological connections among susceptible communities. The mathematical tools used are borrowed from general schemes of reactive transport on river networks acting as the environmental matrix for the circulation and mixing of water-borne pathogens. The results of a large-scale application to the Kwa Zulu (Natal) epidemics of 2001-2002 will be discussed. Useful theoretical results derived in the spatially-explicit context will also be reviewed (like e.g. the exact derivation of the speed of propagation for traveling fronts of epidemics on regular lattices endowed with uniform population density). Network effects will be discussed. The analysis of the limit case of uniformly distributed population density proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. To that extent, it is shown that the ratio between spreading and disease outbreak timescales proves the crucial parameter. The relevance of our results lies in the major differences potentially arising between the predictions of spatially explicit models and traditional compartmental models of the SIR-like type. 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 compartmental models. Finally, a view on further developments includes: hydrologically improved aquatic reservoir models for pathogens; human mobility patterns affecting disease propagation; double-peak emergence and seasonality in the spatially explicit epidemic context.

  12. Stochastic population and epidemic models persistence and extinction

    CERN Document Server

    Allen, Linda J S

    2015-01-01

    This monograph provides a summary of the basic theory of branching processes for single-type and multi-type processes. Classic examples of population and epidemic models illustrate the probability of population or epidemic extinction obtained from the theory of branching processes. The first chapter develops the branching process theory, while in the second chapter two applications to population and epidemic processes of single-type branching process theory are explored. The last two chapters present multi-type branching process applications to epidemic models, and then continuous-time and continuous-state branching processes with applications. In addition, several MATLAB programs for simulating stochastic sample paths  are provided in an Appendix. These notes originated as part of a lecture series on Stochastics in Biological Systems at the Mathematical Biosciences Institute in Ohio, USA. Professor Linda Allen is a Paul Whitfield Horn Professor of Mathematics in the Department of Mathematics and Statistics ...

  13. Ending U.S. Opioid Abuse Epidemic Will Take Years

    Science.gov (United States)

    ... fullstory_167176.html Ending U.S. Opioid Abuse Epidemic Will Take Years: Report Expert panel calls for tighter ... this page, please enable JavaScript. (*this news item will not be available after 10/11/2017) By ...

  14. Epidemic cholera in Latin America: spread and routes of transmission.

    Science.gov (United States)

    Guthmann, J P

    1995-12-01

    In the most recent epidemic of cholera in Latin America, nearly a million cases were reported and almost 9000 people died between January 1991 and December 1993. The epidemic spread rapidly from country to country, affecting in three years all the countries of Latin America except Uruguay and the Caribbean. Case-control studies carried out in Peru showed a significant association between drinking water and risk of disease. Cholera was associated with the consumption of unwashed fruit and vegetables, with eating food from street vendors and with contaminated crabmeat transported in travellers' luggage. This article documents the spread of the epidemic and its routes of transmission and discusses whether the introduction of the epidemic to Peru and its subsequent spread throughout the continent could have been prevented.

  15. Unification of theoretical approaches for epidemic spreading on complex networks.

    Science.gov (United States)

    Wang, Wei; Tang, Ming; Eugene Stanley, H; Braunstein, Lidia A

    2017-03-01

    Models of epidemic spreading on complex networks have attracted great attention among researchers in physics, mathematics, and epidemiology due to their success in predicting and controlling scenarios of epidemic spreading in real-world scenarios. To understand the interplay between epidemic spreading and the topology of a contact network, several outstanding theoretical approaches have been developed. An accurate theoretical approach describing the spreading dynamics must take both the network topology and dynamical correlations into consideration at the expense of increasing the complexity of the equations. In this short survey we unify the most widely used theoretical approaches for epidemic spreading on complex networks in terms of increasing complexity, including the mean-field, the heterogeneous mean-field, the quench mean-field, dynamical message-passing, link percolation, and pairwise approximation. We build connections among these approaches to provide new insights into developing an accurate theoretical approach to spreading dynamics on complex networks.

  16. Epidemic spread in bipartite network by considering risk awareness

    Science.gov (United States)

    Han, She; Sun, Mei; Ampimah, Benjamin Chris; Han, Dun

    2018-02-01

    Human awareness plays an important role in the spread of infectious diseases and the control of propagation patterns. Exploring the interplay between human awareness and epidemic spreading is a topic that has been receiving increasing attention. Considering the fact, some well-known diseases only spread between different species we propose a theoretical analysis of the Susceptible-Infected-Susceptible (SIS) epidemic spread from the perspective of bipartite network and risk aversion. Using mean field theory, the epidemic threshold is calculated theoretically. Simulation results are consistent with the proposed analytic model. The results show that, the final infection density is negative linear with the value of individuals' risk awareness. Therefore, the epidemic spread could be effectively suppressed by improving individuals' risk awareness.

  17. [Epidemics and disease during the Revolution Period in Mexico].

    Science.gov (United States)

    Sanfilippo-Borrás, José

    2010-01-01

    The health condition in Mexico was bad around de beginning of the revolutionary period. The movement of troops led the development of epidemics like yellow fever, typhus, smallpox, and influenza that were enhance with natural disasters and hunger in whole country, from cost to cost and in the north big cities like Monterrey, Guadalajara and Saltillo. Doctor Liceaga conducted a well planned campaign against yellow fever eradicating water stagnant deposits in order to combat the vector transmission, the Aedes aegypti, mosquito with satisfactory results. The first smallpox epidemic in the XX Century in Mexico was in 1916. The Mexican physicians used the smallpox vaccine against this epidemic. An American physician named Howard Taylor Ricketts arrived to Mexico for studying the typhus transmission. Accidentally he had been infected and finally, he died from typhus. Definitively, the epidemics predominate along de revolutionary period in Mexico.

  18. 'Loneliness Epidemic' Called a Major Public Health Threat

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_167643.html 'Loneliness Epidemic' Called a Major Public Health Threat Social ... 7, 2017 MONDAY, Aug. 7, 2017 (HealthDay News) -- Loneliness may be more hazardous to your health than ...

  19. Epidemic spreading in time-varying community networks

    Energy Technology Data Exchange (ETDEWEB)

    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); 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)

    2014-06-15

    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 < q{sub c}. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

  20. Hybrid epidemics--a case study on computer worm conficker.

    Science.gov (United States)

    Zhang, Changwang; Zhou, Shi; Chain, Benjamin M

    2015-01-01

    Conficker is a computer worm that erupted on the Internet in 2008. It is unique in combining three different spreading strategies: local probing, neighbourhood probing, and global probing. We propose a mathematical model that combines three modes of spreading: local, neighbourhood, and global, to capture the worm's spreading behaviour. The parameters of the model are inferred directly from network data obtained during the first day of the Conficker epidemic. The model is then used to explore the tradeoff between spreading modes in determining the worm's effectiveness. Our results show that the Conficker epidemic is an example of a critically hybrid epidemic, in which the different modes of spreading in isolation do not lead to successful epidemics. Such hybrid spreading strategies may be used beneficially to provide the most effective strategies for promulgating information across a large population. When used maliciously, however, they can present a dangerous challenge to current internet security protocols.

  1. Hybrid epidemics--a case study on computer worm conficker.

    Directory of Open Access Journals (Sweden)

    Changwang Zhang

    Full Text Available Conficker is a computer worm that erupted on the Internet in 2008. It is unique in combining three different spreading strategies: local probing, neighbourhood probing, and global probing. We propose a mathematical model that combines three modes of spreading: local, neighbourhood, and global, to capture the worm's spreading behaviour. The parameters of the model are inferred directly from network data obtained during the first day of the Conficker epidemic. The model is then used to explore the tradeoff between spreading modes in determining the worm's effectiveness. Our results show that the Conficker epidemic is an example of a critically hybrid epidemic, in which the different modes of spreading in isolation do not lead to successful epidemics. Such hybrid spreading strategies may be used beneficially to provide the most effective strategies for promulgating information across a large population. When used maliciously, however, they can present a dangerous challenge to current internet security protocols.

  2. Underrecognition of Dengue during 2013 Epidemic in Luanda, Angola.

    Science.gov (United States)

    Sharp, Tyler M; Moreira, Rosa; Soares, Maria José; Miguel da Costa, Lúis; Mann, Jennifer; DeLorey, Mark; Hunsperger, Elizabeth; Muñoz-Jordán, Jorge L; Colón, Candimar; Margolis, Harold S; de Caravalho, Adelaide; Tomashek, Kay M

    2015-08-01

    During the 2013 dengue epidemic in Luanda, Angola, 811 dengue rapid diagnostic test-positive cases were reported to the Ministry of Health. To better understand the magnitude of the epidemic and identify risk factors for dengue virus (DENV) infection, we conducted cluster surveys around households of case-patients and randomly selected households 6 weeks after the peak of the epidemic. Of 173 case cluster participants, 16 (9%) exhibited evidence of recent DENV infection. Of 247 random cluster participants, 25 (10%) had evidence of recent DENV infection. Of 13 recently infected participants who had a recent febrile illness, 7 (54%) had sought medical care, and 1 (14%) was hospitalized with symptoms consistent with severe dengue; however, none received a diagnosis of dengue. Behavior associated with protection from DENV infection included recent use of mosquito repellent or a bed net. These findings suggest that the 2013 dengue epidemic was larger than indicated by passive surveillance data.

  3. Interplay between epidemic spread and information propagation on metapopulation networks.

    Science.gov (United States)

    Wang, Bing; Han, Yuexing; Tanaka, Gouhei

    2017-05-07

    The spread of an infectious disease has been widely found to evolve with the propagation of information. Many seminal works have demonstrated the impact of information propagation on the epidemic spreading, assuming that individuals are static and no mobility is involved. Inspired by the recent observation of diverse mobility patterns, we incorporate the information propagation into a metapopulation model based on the mobility patterns and contagion process, which significantly alters the epidemic threshold. In more details, we find that both the information efficiency and the mobility patterns have essential impacts on the epidemic spread. We obtain different scenarios leading to the mitigation of the outbreak by appropriately integrating the mobility patterns and the information efficiency as well. The inclusion of the impacts of the information propagation into the epidemiological model is expected to provide an support to public health implications for the suppression of epidemics. Copyright © 2017. Published by Elsevier Ltd.

  4. Effects of active links on epidemic transmission over social networks

    Science.gov (United States)

    Zhu, Guanghu; Chen, Guanrong; Fu, Xinchu

    2017-02-01

    A new epidemic model with two infection periods is developed to account for the human behavior in social network, where newly infected individuals gradually restrict most of future contacts or are quarantined, causing infectivity change from a degree-dependent form to a constant. The corresponding dynamics are formulated by a set of ordinary differential equations (ODEs) via mean-field approximation. The effects of diverse infectivity on the epidemic dynamics ​are examined, with a behavioral interpretation of the basic reproduction number. Results show that such simple adaptive reactions largely determine the impact of network structure on epidemics. Particularly, a theorem proposed by Lajmanovich and Yorke in 1976 is generalized, so that it can be applied for the analysis of the epidemic models with multi-compartments especially network-coupled ODE systems.

  5. The changing epidemiology of the bronchiolitis epidemic in Tallaght Hospital

    National Research Council Canada - National Science Library

    O'Connor, G; Tariq, M; Greally, P; Elnazir, B

    2013-01-01

    Bronchiolitis affects one third of babies in their first year of life. We investigated all bronchiolitis admissions to Tallaght Hospital in the last five years, with the hope of providing an insight into the epidemic in an Irish population...

  6. Spatial spread of the West Africa Ebola epidemic.

    Science.gov (United States)

    Kramer, Andrew M; Pulliam, J Tomlin; Alexander, Laura W; Park, Andrew W; Rohani, Pejman; Drake, John M

    2016-08-01

    Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013-2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia and Sierra Leone and neighbouring countries. This model out-performed alternative models based on diffusive spread, the force of infection, mobility estimated from cell phone records and other hypothesized patterns of spread. These findings highlight the importance of integrated geography to epidemic expansion and may contribute to identifying both the most vulnerable unaffected areas and locations of maximum intervention value.

  7. Type 2 diabetes: the emerging epidemic | Rheeder | South African ...

    African Journals Online (AJOL)

    Abstract. This article reports on the prevalence of diabetes in South Africa and gives projections for the epidemic proportions that this disease may take by the year 2030. South African Family Practice Vol. 48 (10) 2006: pp. 20 ...

  8. The Topological Weighted Centroid (TWC): A topological approach to the time-space structure of epidemic and pseudo-epidemic processes

    Science.gov (United States)

    Buscema, Massimo; Massini, Giulia; Sacco, Pier Luigi

    2018-02-01

    This paper offers the first systematic presentation of the topological approach to the analysis of epidemic and pseudo-epidemic spatial processes. We introduce the basic concepts and proofs, at test the approach on a diverse collection of case studies of historically documented epidemic and pseudo-epidemic processes. The approach is found to consistently provide reliable estimates of the structural features of epidemic processes, and to provide useful analytical insights and interpretations of fragmentary pseudo-epidemic processes. Although this analysis has to be regarded as preliminary, we find that the approach's basic tenets are strongly corroborated by this first test and warrant future research in this vein.

  9. Elecnuc. Nuclear power plants worldwide; Elecnuc. Les centrales nucleaires dans le monde

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    This small folder presents a digest of some useful information concerning the nuclear power plants worldwide and the situation of nuclear industry at the end of 1997: power production of nuclear origin, distribution of reactor types, number of installed units, evolution and prediction of reactor orders, connections to the grid and decommissioning, worldwide development of nuclear power, evolution of power production of nuclear origin, the installed power per reactor type, market shares and exports of the main nuclear engineering companies, power plants constructions and orders situation, evolution of reactors performances during the last 10 years, know-how and development of nuclear safety, the remarkable facts of 1997, the future of nuclear power and the energy policy trends. (J.S.)

  10. Multilocus sequence analysis of Aspergillus Sect. Nigri in dried vine fruits of worldwide origin.

    Science.gov (United States)

    Susca, Antonia; Perrone, Giancarlo; Cozzi, Giuseppe; Stea, Gaetano; Logrieco, Antonio F; Mulè, Giuseppina

    2013-07-15

    Dried vine fruits may be heavily colonized by Aspergillus species. The molecular biodiversity of an Aspergillus population (234 strains) isolated from dried vine fruit samples of worldwide origin were analyzed by investigating four housekeeping gene loci (calmodulin, β-tubulin, elongation factor 1-α, RPB2). Aspergillus Sect. Nigri was dominant and the strains were identified as A. tubingensis (138), A. awamori (38), A. carbonarius (27), A. uvarum (16) and A. niger (11). Four Aspergillus flavus strains were also identified from Chilean raisins. Two clusters closely related to the A. tubingensis species with a significant bootstrap (60% and 99%) were identified as distinct populations. Among the four loci, RPB2 showed the highest genetic variability. This is the first complete study on the worldwide distribution of black Aspergilli occurring on dried vine fruits identified by a molecular approach. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Molecular characterization of Cryptosporidium parvum and Cryptosporidium hominis GP60 subtypes worldwide

    Directory of Open Access Journals (Sweden)

    Catalina Avendaño V

    2017-09-01

    Full Text Available Cryptosporidium is a zoonotic parasite very important in animal health as well as in public health. It is because this is one of the main causes of diarrhea in children, calves, lambs and other variety of youth mammalians in a lot of countries. The globalization has enabled the exchange of biological material in different regions worldwide, encouraging the spread of diseases and exposure to these biological agents to different environmental conditions, inducing adaptation through genetic changes. Based in the polymorphism of the gene for GP60, this review intended to present the distribution of Cryptosporidium parvum and Cryptosporidium hominis in humans and calves worldwide. The subtype that affects cattle more frequently corresponds to IIaA15G2R; while the subtype most frequently isolated from human samples is IaA19G2.

  12. EVALUATION AND PREDICTIVE METHODS OF EPIDEMICAL SITUATION IN THE AREA OF ACUTE ENTERIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    Malysh N.G.

    2017-06-01

    Full Text Available Introduction. Despite the fact, that nowadays acute intestinal infections (AII sick rate is decreasing, the aggravation of the epidemical situation is always there. Increased attention to AII caused by unpredictable epidemical rises of the AII diseases, which cannot be prevented without assessing the epidemical situation of these infections and forecasting of the levels of sick rate. However, developed mathematical methods of forecasting in most cases do not take into account the risk factors, also they are time-consuming and it is difficult to calculate them; and developed special computer programs, which predict infectious sick rates, are often in the lack in the institutions of sanitary-epidemiological service. An urgent problem for today is establishing of the most influential social and environmental factors, which can make a contribution to the spread of AII. The aim of this work was to improve the method of assessment and prediction of epidemic situation of AII by identifying the influence of climatic and demographic factors. Materials and methods. In order to determine the influence of meteorological and demographic factors on the epidemic process of acute intestinal infections the official reports of the State Sanitary and Epidemiological Service of Ukraine in Sumy region, the Department of Statistics, Sumy Regional Center for Hydrometeorology and Environmental Monitoring have been studied. Results and discussion. The work on the evaluation of the epidemiological situation of the AII begins from collecting data, according to the AII sick rate. The main source of this information is the logbook of infectious diseases, which recorded all sick people that were found in the area. It is necessary to gather the initial information, calculate the sick rate and monthly distribution of AII cases on investigated area and evaluate the tendency. At the same time with accounting of AII cases on investigated territory, takes place a monitoring of air

  13. A simple model for behaviour change in epidemics

    Directory of Open Access Journals (Sweden)

    Brauer Fred

    2011-02-01

    Full Text Available Abstract Background People change their behaviour during an epidemic. Infectious members of a population may reduce the number of contacts they make with other people because of the physical effects of their illness and possibly because of public health announcements asking them to do so in order to decrease the number of new infections, while susceptible members of the population may reduce the number of contacts they make in order to try to avoid becoming infected. Methods We consider a simple epidemic model in which susceptible and infectious members respond to a disease outbreak by reducing contacts by different fractions and analyze the effect of such contact reductions on the size of the epidemic. We assume constant fractional reductions, without attempting to consider the way in which susceptible members might respond to information about the epidemic. Results We are able to derive upper and lower bounds for the final size of an epidemic, both for simple and staged progression models. Conclusions The responses of uninfected and infected individuals in a disease outbreak are different, and this difference affects estimates of epidemic size.

  14. Predictive analysis effectiveness in determining the epidemic disease infected area

    Science.gov (United States)

    Ibrahim, Najihah; Akhir, Nur Shazwani Md.; Hassan, Fadratul Hafinaz

    2017-10-01

    Epidemic disease outbreak had caused nowadays community to raise their great concern over the infectious disease controlling, preventing and handling methods to diminish the disease dissemination percentage and infected area. Backpropagation method was used for the counter measure and prediction analysis of the epidemic disease. The predictive analysis based on the backpropagation method can be determine via machine learning process that promotes the artificial intelligent in pattern recognition, statistics and features selection. This computational learning process will be integrated with data mining by measuring the score output as the classifier to the given set of input features through classification technique. The classification technique is the features selection of the disease dissemination factors that likely have strong interconnection between each other in causing infectious disease outbreaks. The predictive analysis of epidemic disease in determining the infected area was introduced in this preliminary study by using the backpropagation method in observation of other's findings. This study will classify the epidemic disease dissemination factors as the features for weight adjustment on the prediction of epidemic disease outbreaks. Through this preliminary study, the predictive analysis is proven to be effective method in determining the epidemic disease infected area by minimizing the error value through the features classification.

  15. The impact of vaccine success and awareness on epidemic dynamics

    Science.gov (United States)

    Juang, Jonq; Liang, Yu-Hao

    2016-11-01

    The role of vaccine success is introduced into an epidemic spreading model consisting of three states: susceptible, infectious, and vaccinated. Moreover, the effect of three types, namely, contact, local, and global, of infection awareness and immunization awareness is also taken into consideration. The model generalizes those considered in Pastor-Satorras and Vespignani [Phys. Rev. E 63, 066117 (2001)], Pastor-Satorras and Vespignani [Phys. Rev. E 65, 036104 (2002)], Moreno et al. [Eur. Phys. J. B 26, 521-529 (2002)], Wu et al. [Chaos 22, 013101 (2012)], and Wu et al. [Chaos 24, 023108 (2014)]. Our main results contain the following. First, the epidemic threshold is explicitly obtained. In particular, we show that, for any initial conditions, the epidemic eventually dies out regardless of what other factors are whenever some type of immunization awareness is considered, and vaccination has a perfect success. Moreover, the threshold is independent of the global type of awareness. Second, we compare the effect of contact and local types of awareness on the epidemic thresholds between heterogeneous networks and homogeneous networks. Specifically, we find that the epidemic threshold for the homogeneous network can be lower than that of the heterogeneous network in an intermediate regime for intensity of contact infection awareness while it is higher otherwise. In summary, our results highlight the important and crucial roles of both vaccine success and contact infection awareness on epidemic dynamics.

  16. Parasite transmission in social interacting hosts: Monogenean epidemics in guppies

    Science.gov (United States)

    Johnson, Mirelle B.; Lafferty, Kevin D.; van Oosterhout, Cock; Cable, Joanne

    2011-01-01

    Background Infection incidence increases with the average number of contacts between susceptible and infected individuals. Contact rates are normally assumed to increase linearly with host density. However, social species seek out each other at low density and saturate their contact rates at high densities. Although predicting epidemic behaviour requires knowing how contact rates scale with host density, few empirical studies have investigated the effect of host density. Also, most theory assumes each host has an equal probability of transmitting parasites, even though individual parasite load and infection duration can vary. To our knowledge, the relative importance of characteristics of the primary infected host vs. the susceptible population has never been tested experimentally. Methodology/Principal Findings Here, we examine epidemics using a common ectoparasite, Gyrodactylus turnbulli infecting its guppy host (Poecilia reticulata). Hosts were maintained at different densities (3, 6, 12 and 24 fish in 40 L aquaria), and we monitored gyrodactylids both at a population and individual host level. Although parasite population size increased with host density, the probability of an epidemic did not. Epidemics were more likely when the primary infected fish had a high mean intensity and duration of infection. Epidemics only occurred if the primary infected host experienced more than 23 worm days. Female guppies contracted infections sooner than males, probably because females have a higher propensity for shoaling. Conclusions/Significance These findings suggest that in social hosts like guppies, the frequency of social contact largely governs disease epidemics independent of host density.

  17. Parasite transmission in social interacting hosts: monogenean epidemics in guppies.

    Directory of Open Access Journals (Sweden)

    Mirelle B Johnson

    Full Text Available BACKGROUND: Infection incidence increases with the average number of contacts between susceptible and infected individuals. Contact rates are normally assumed to increase linearly with host density. However, social species seek out each other at low density and saturate their contact rates at high densities. Although predicting epidemic behaviour requires knowing how contact rates scale with host density, few empirical studies have investigated the effect of host density. Also, most theory assumes each host has an equal probability of transmitting parasites, even though individual parasite load and infection duration can vary. To our knowledge, the relative importance of characteristics of the primary infected host vs. the susceptible population has never been tested experimentally. METHODOLOGY/PRINCIPAL FINDINGS: Here, we examine epidemics using a common ectoparasite, Gyrodactylus turnbulli infecting its guppy host (Poecilia reticulata. Hosts were maintained at different densities (3, 6, 12 and 24 fish in 40 L aquaria, and we monitored gyrodactylids both at a population and individual host level. Although parasite population size increased with host density, the probability of an epidemic did not. Epidemics were more likely when the primary infected fish had a high mean intensity and duration of infection. Epidemics only occurred if the primary infected host experienced more than 23 worm days. Female guppies contracted infections sooner than males, probably because females have a higher propensity for shoaling. CONCLUSIONS/SIGNIFICANCE: These findings suggest that in social hosts like guppies, the frequency of social contact largely governs disease epidemics independent of host density.

  18. Association of Drought with Typhus Epidemics in Central Mexico

    Science.gov (United States)

    Acuna-Soto, R.; Stahle, D.; Villanueva Diaz, J.; Therrell, M.

    2007-05-01

    Typhus is an acute infectious disease caused by the bacteria Rickettsia prowazekii, which is transmitted among humans by the body lice (Pediculus humanus corporis). The disease is highly contagious and transmission is favored in populations living in crowded conditions. Under these circumstances, typhus transmission is facilitated by factors that favor the colonization and proliferation of body lice such as absence of personal hygiene and wearing the same clothes for long periods of time. Historically, periods of war and famine were associated with devastating epidemics with high mortality rates in many parts of the world. Central Mexico has a long record of typhus epidemics. In this region, at > 2000 meters above sea level, the disease was endemic and occurred with a seasonal pattern in winter, with occasional large epidemics. Recently, we completed a chronology of epidemics in Mexico. A total of 22 well-defined major typhus epidemics were identified between 1650 and 1920. All of them caused periods of increased mortality that lasted 2 - 4 years (more than one standard deviation from the previous ten year period). The record of typhus epidemics was evaluated against the tree-ring record of Cuauhtmoc La Fragua, Puebla. This chronology, based on Douglas fir, has demonstrated to be a faithful record of precipitation in central Mexico. The results indicate that a statistically significant drought (t test, p war. This indicates that drought alone was capable of inducing the social conditions for increased transmission of typhus in pre-industrial central Mexico.

  19. Mathematical models to characterize early epidemic growth: A review

    Science.gov (United States)

    Chowell, Gerardo; Sattenspiel, Lisa; Bansal, Shweta; Viboud, Cécile

    2016-09-01

    There is a long tradition of using mathematical models to generate insights into the transmission dynamics of infectious diseases and assess the potential impact of different intervention strategies. The increasing use of mathematical models for epidemic forecasting has highlighted the importance of designing reliable models that capture the baseline transmission characteristics of specific pathogens and social contexts. More refined models are needed however, in particular to account for variation in the early growth dynamics of real epidemics and to gain a better understanding of the mechanisms at play. Here, we review recent progress on modeling and characterizing early epidemic growth patterns from infectious disease outbreak data, and survey the types of mathematical formulations that are most useful for capturing a diversity of early epidemic growth profiles, ranging from sub-exponential to exponential growth dynamics. Specifically, we review mathematical models that incorporate spatial details or realistic population mixing structures, including meta-population models, individual-based network models, and simple SIR-type models that incorporate the effects of reactive behavior changes or inhomogeneous mixing. In this process, we also analyze simulation data stemming from detailed large-scale agent-based models previously designed and calibrated to study how realistic social networks and disease transmission characteristics shape early epidemic growth patterns, general transmission dynamics, and control of international disease emergencies such as the 2009 A/H1N1 influenza pandemic and the 2014-2015 Ebola epidemic in West Africa.

  20. Comparing large-scale computational approaches to epidemic modeling: Agent-based versus structured metapopulation models

    Directory of Open Access Journals (Sweden)

    Merler Stefano

    2010-06-01

    Full Text Available Abstract Background In recent years large-scale computational models for the realistic simulation of epidemic outbreaks have been used with increased frequency. Methodologies adapt to the scale of interest and range from very detailed agent-based models to spatially-structured metapopulation models. One major issue thus concerns to what extent the geotemporal spreading pattern found by different modeling approaches may differ and depend on the different approximations and assumptions used. Methods We provide for the first time a side-by-side comparison of the results obtained with a stochastic agent-based model and a structured metapopulation stochastic model for the progression of a baseline pandemic event in Italy, a large and geographically heterogeneous European country. The agent-based model is based on the explicit representation of the Italian population through highly detailed data on the socio-demographic structure. The metapopulation simulations use the GLobal Epidemic and Mobility (GLEaM model, based on high-resolution census data worldwide, and integrating airline travel flow data with short-range human mobility patterns at the global scale. The model also considers age structure data for Italy. GLEaM and the agent-based models are synchronized in their initial conditions by using the same disease parameterization, and by defining the same importation of infected cases from international travels. Results The results obtained show that both models provide epidemic patterns that are in very good agreement at the granularity levels accessible by both approaches, with differences in peak timing on the order of a few days. The relative difference of the epidemic size depends on the basic reproductive ratio, R0, and on the fact that the metapopulation model consistently yields a larger incidence than the agent-based model, as expected due to the differences in the structure in the intra-population contact pattern of the approaches. The age