1,087 research outputs found

    Accessible areas in ecological niche comparisons of invasive species: Recognized but still overlooked

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    Understanding biological invasions is crucial for their control and prevention. Specially, establishing whether invasive species operate within the constraint of conservative ecological niches, or if niche shifts occur at all commonly as part of the invasion process, is indispensable to identifying and anticipating potential areas of invasion. Ecological niche modeling (ENM) has been used to address such questions, but improvements and debate in study design, model evaluation, and methods are still needed to mature this field. We reanalyze data for Gray Squirrels (Sciurus carolinensis), native to North America, but invasive in Europe. Our main finding was that, when the analysis extent is established carefully based on analogous sets of environmental conditions, all evidence of niche shifts disappears, suggesting that previous reports of niche shifts for this species are artifacts of methods and interpretation, rather than biological reality. Niche conservatism should be tested only within appropriate, similar, environmental spaces that are accessible to both species or populations being compared, thus avoiding model extrapolation related to model transfers. Testing for environmental similarity between native and invaded areas is critical to identifying niche shifts during species invasion robustly, but also in applications of ENM to understanding temporal dimensions of niche dynamics

    Zika Virus, Elevation, and Transmission Risk

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    Introduction: Zika virus has appeared in the Americas in the form of a major outbreak, and is now known to cause birth defects when pregnant women are infected. As a result, the Centers for Disease Control and Prevention issued travel guidelines, in the form of an elevational risk definition: destinations below 2000m are considered as at-risk. Methods: We explored the distribution of known Zika virus vector mosquito species in relation to climatic conditions, elevation, latitude, and air traffic connections to the United States. Results: In view of the tropical and subtropical nature of the mosquito species that are the primary Zika virus vectors, we point out that climate varies rather dramatically with respect to elevation and latitude, such that a single elevational criterion will be a poor predictor of potential for transmission. Discussion: We suggest an initial adjustment would consider latitude in addition to elevation; a more definitive, quantitative analysis of risk would consider variables of ecology, climate, human condition, and connectivity of areas

    Novel Methods in Disease Biogeography: A Case Study with Heterosporosis

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    Disease biogeography is currently a promising field to complement epidemiology, and ecological niche modeling theory and methods are a key component. Therefore, applying the concepts and tools from ecological niche modeling to disease biogeography and epidemiology will provide biologically sound and analytically robust descriptive and predictive analyses of disease distributions. As a case study, we explored the ecologically important fish disease Heterosporosis, a relatively poorly understood disease caused by the intracellular microsporidian parasite Heterosporis sutherlandae. We explored two novel ecological niche modeling methods, the minimum-volume ellipsoid (MVE) and the Marble algorithm, which were used to reconstruct the fundamental and the realized ecological niche of H. sutherlandae, respectively. Additionally, we assessed how the management of occurrence reports can impact the output of the models. Ecological niche models were able to reconstruct a proxy of the fundamental and realized niche for this aquatic parasite, identifying specific areas suitable for Heterosporosis. We found that the conceptual and methodological advances in ecological niche modeling provide accessible tools to update the current practices of spatial epidemiology. However, careful data curation and a detailed understanding of the algorithm employed are critical for a clear definition of the assumptions implicit in the modeling process and to ensure biologically sound forecasts. In this paper, we show how sensitive MVE is to the input data, while Marble algorithm may provide detailed forecasts with a minimum of parameters. We showed that exploring algorithms of different natures such as environmental clusters, climatic envelopes, and logistic regressions (e.g., Marble, MVE, and Maxent) provide different scenarios of potential distribution. Thus, no single algorithm should be used for disease mapping. Instead, different algorithms should be employed for a more informed and complete understanding of the pathogen or parasite in question

    The Role of Proteasome Inhibition in Nonsmall Cell Lung Cancer

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    Lung cancer therapy with current available chemotherapeutic agents is mainly palliative. For these and other reasons there is now a great interest to find targeted therapies that can be effective not only palliating lung cancer or decreasing treatment-related toxicity, but also giving hope to cure these patients. It is already well known that the ubiquitin-proteasome system like other cellular pathways is critical for the proliferation and survival of cancer cells; thus, proteosome inhibition has become a very attractive anticancer therapy. There are several phase I and phase II clinical trials now in non-small cell lung cancer and small cell lung cancer using this potential target. Most of the trials use bortezomib in combination with chemotherapeutic agents. This paper tends to make a state-of-the-art review based on the available literature regarding the use of bortezomib as a single agent or in combination with chemotherapy in patients with lung cancer

    Semantic Invoice Processing

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    This work highlights how to transform information from invoice documents to semantic models, as an implementation of ontology modeling. The migration from printed paper to digital documents in the Mexican Government Offices in the last few years has brought significant opportunities for the usage of information technologies and applications. However, when changing digital document information into knowledge, there are still many gaps to be filled. This work proposes a solution to some issues regarding ontology modeling, specifically when mapping a document that follows some XML schema to an ontology under the OWL standard. The main contribution of this work is to provide new interpretations of the XML terms in the context of OWL, so that the XML Schema Definition (XSD) structures can be mapped into more complex OWL structures. A software tool developed to test and validate the information extraction strategies proposed is presented here.ITESO, A.C.Consejo Nacional de Ciencia y Tecnologí

    Wildlife veterinarians rabies vaccination in Chile: a survey

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    Indexación: Web of Science; Scielo.Introduction: Rabies is a lethal but preventable disease. Knowing the extent of immunization coverage among at risk populations, may help to guide immunization efforts, as well as increase the effectiveness of rabies control and prevention programs. Aim: To determine the proportion of wildlife veterinarians in Chile, as part of a group at risk of rabies transmission. Methods: An electronic survey was sent to wildlife veterinarians in Chile. Results: We found that veterinarians in Chile work mainly with carnivores and deer compared to other mammals (p < 0.001), rarely works with bats (p = 0.6572). Most of the participants had been bitten by domestic animals, while a lesser proportion (29%) by wild animals. Most of the participants never received rabies vaccination (53%), while within the group that had started a rabies vaccination scheme, a substantial proportion (39%) did not complete it. Discussion and conclusion: Identify the vaccination status of risk groups is important for infectious disease control and prevention programs, as this information helps to identify priority groups during outbreaks or vaccine scarcity. Wildlife veterinarians in Chile are at risk of rabies transmission and should be included in rabies prevention programs, especially considering their vulnerability and lack of biosafety practices. Increasing education in rabies epidemiology and prevention is urgently needed in veterinary faculties in Chile.Introducción: La rabia es una enfermedad infecciosa mortal pero prevenible. Establecer si existe una adecuada inmunización pre-exposición contra la rabia en un grupo de riesgo, puede ayudar a enfocar los esfuerzos de inmunización para hacer efectivos los programas de control y prevención de la enfermedad. Objetivo: Determinar mediante una encuesta la proporción de veterinarios de fauna silvestre como grupo de riesgo que han recibido inmunización contra la rabia. Métodos: Se realizó una encuesta electrónica a veterinarios de fauna de vida silvestre de Chile. Resultados: Los veterinarios encuestados tienden a trabajar con carnívoros y ciervos en comparación con otros mamíferos (p < 0,001), rara vez con murciélagos (p = 0,6572). La mayoría de los encuestados había sido mordido por animales domésticos y una proporción menor (29%) por animales silvestres. La mayoría nunca había sido vacunado contra la rabia (53%), mientras que del grupo que sí había recibido vacunación anti-rábica, una importante proporción (39%) no completó el esquema de vacunación. Sorprendentemente, este grupo de profesionales rara vez trabaja con murciélagos (p = 0,6572), lo que puede reducir su exposición a linajes de rabia transmitida por murciélagos. Discusión y Conclusión: Identificar el estado de inmunización contra la rabia en grupos de riesgo es una información importante para evaluar los programas de prevención y control de enfermedades infecciosas y podría ayudar a identificar grupos prioritarios en situaciones de brote o escasez de vacuna. Los veterinarios de fauna de vida silvestre en Chile constituyen un grupo vulnerable: no mantienen prácticas de bioseguridad necesarias y tienen riesgo de adquirir la encefalitis rábica por lo que deberían ser considerados en los programas de prevención pre-exposición de la enfermedad. La educación sobre la epidemiología y prevención de la rabia es urgente en las facultades de medicina veterinaria en Chile.http://ref.scielo.org/c5d5b

    Carnivore-Livestock Conflicts in Chile: Evidence and Methods for Mitigation

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    Human population growth and habitat loss have exacerbated human–wildlife conflicts worldwide. We explored trends in human–wildlife conflicts (HWCs) in Chile using scientific and official reports to identify areas and species with higher risk of conflicts and tools available for their prevention and mitigation. The puma (Puma concolor) was considered the most frequent predator; however, fox (Lycalopex spp.) and free-ranging or feral dog (Canis lupus familiaris) attacks were also common. Our results suggest that the magnitude of puma conflicts may be overestimated. Domestic sheep (Ovis spp.) and poultry (Galliformes) were the most common species predated. Livestock losses were widespread across Chile but were highest in San Jose de Maipo, located in central Chile, and Cochrane, La Unión, and Lago Verde in south Chile municipalities. Livestock guardian dogs and the livestock insurance, as a part of the Agriculture Insurance of Chile, were identified as the most promising tools to mitigate HWCs, short- and mid-term, respectively. However, longer-term strategies should focus on improving livestock management through extension (i.e., farmer education) programs for local communities. In Chile, HWCs negatively impact small farmers and wild carnivore populations. An interinstitutional and interdisciplinary strategy integrating input from government and nongovernmental organizations, farmers, and academia is needed to achieve effective carnivore conservation in the long-term

    Successful strategies implemented towards the elimination of canine rabies in the Western Hemisphere

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    Almost all cases of human rabies result from dog bites, making the elimination of canine rabies a global priority. During recent decades, many countries in the Western Hemisphere have carried out large-scale dog vaccination campaigns, controlled their free-ranging dog populations and enforced legislation for responsible pet ownership. This article reviews progress in eliminating canine rabies from the Western Hemisphere. After briefly summarizing the history of control efforts and describing the approaches listed above, we note that programs in some countries have been hindered by societal attitudes and severe economic disparities, which underlines the need to discuss measures that will be required to complete the elimination of canine rabies throughout the region. We also note that there is a constant threat for dog-maintained epizootics to re-occur, so as long as dog-maintained rabies "hot spots" are still present, free-roaming dog populations remain large, herd immunity becomes low and dog-derived rabies lyssavirus (RABLV) variants continue to circulate in close proximity to rabies-naïve dog populations. The elimination of dog-maintained rabies will be only feasible if both dog-maintained and dog-derived RABLV lineages and variants are permanently eliminated. This may be possible by keeping dog herd immunity above 70% at all times, fostering sustained laboratory-based surveillance through reliable rabies diagnosis and RABLV genetic typing in dogs, domestic animals and wildlife, as well as continuing to educate the population on the risk of rabies transmission, prevention and responsible pet ownership. Complete elimination of canine rabies requires permanent funding, with governments and people committed to make it a reality. An accompanying article reviews the history and epidemiology of canine rabies in the Western Hemisphere, beginning with its introduction during the period of European colonization, and discusses how spillovers of viruses between dogs and various wild carnivores will affect future eradication efforts (Velasco-Villa et al., 2017)

    Tracking infectious diseases in a warming world.

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    Using infectious diseases sensitive to climate as indicators of climate change helps stimulate andinform public health response

    Epidemiology of dengue fever in Guatemala

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    Dengue fever occurs worldwide and about 1% of cases progress to severe haemorrhage and shock. Dengue is endemic in Guatemala and its surveillance system could document long term trends. We analysed 17 years of country-wide dengue surveillance data in Guatemala to describe epidemiological trends from 2000 to 2016.Data from the national dengue surveillance database were analysed to describe dengue serotype frequency, seasonality, and outbreaks. We used Poisson regression models to compare the number of cases each year with subsequent years and to estimate incidence ratios within serotype adjusted by age and gender. 91,554 samples were tested. Dengue was confirmed by RT-qPCR, culture or NS1-ELISA in 7097 (7.8%) cases and was IgM ELISA-positive in 19,290 (21.1%) cases. DENV1, DENV2, DENV3, and DENV4 were detected in 2218 (39.5%), 2580 (45.9%), 591 (10.5%), and 230 (4.1%) cases. DENV1 and DENV2 were the predominant serotypes, but all serotypes caused epidemics. The largest outbreak occurred in 2010 with 1080 DENV2 cases reported. The incidence was higher among adults during epidemic years, with significant increases in 2005, 2007, and 2013 DENV1 outbreaks, the 2010 DENV2 and 2003 DENV3 outbreaks. Adults had a lower incidence immediately after epidemics, which is likely linked to increased immunity
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