The Education of Population Scientists.
ERIC Educational Resources Information Center
Malcolm, Janet M.; Cargille, Charles M.
Population science, a combination of natural science, social science, and management science, deals with the phenomena associated with the human population size. Subjects include the rates of change of the sizes of the various subsets of the human population, the causes and results of those changes, the societal pressures for control of population…
Hunting as a management tool? Cougar-human conflict is positively related to trophy hunting.
Teichman, Kristine J; Cristescu, Bogdan; Darimont, Chris T
2016-10-11
Overexploitation and persecution of large carnivores resulting from conflict with humans comprise major causes of declines worldwide. Although little is known about the interplay between these mortality types, hunting of predators remains a common management strategy aimed at reducing predator-human conflict. Emerging theory and data, however, caution that such policy can alter the age structure of populations, triggering increased conflict in which conflict-prone juveniles are involved. Using a 30-year dataset on human-caused cougar (Puma concolor) kills in British Columbia (BC), Canada, we examined relationships between hunter-caused and conflict-associated mortality. Individuals that were killed via conflict with humans were younger than hunted cougars. Accounting for human density and habitat productivity, human hunting pressure during or before the year of conflict comprised the most important variables. Both were associated with increased male cougar-human conflict. Moreover, in each of five regions assessed, conflict was higher with increased human hunting pressure for at least one cougar sex. Although only providing correlative evidence, such patterns over large geographic and temporal scales suggest that alternative approaches to conflict mitigation might yield more effective outcomes for humans as well as cougar populations and the individuals within populations.
Newby, Jesse R.; Mills, L. Scott; Ruth, Toni K.; Pletscher, Daniel H.; Mitchell, Michael S.; Quigley, Howard B.; Murphy, Kerry M.; DeSimone, Rich
2013-01-01
An understanding of how stressors affect dispersal attributes and the contribution of local populations to multi-population dynamics are of immediate value to basic and applied ecology. Puma (Puma concolor) populations are expected to be influenced by inter-population movements and susceptible to human-induced source–sink dynamics. Using long-term datasets we quantified the contribution of two puma populations to operationally define them as sources or sinks. The puma population in the Northern Greater Yellowstone Ecosystem (NGYE) was largely insulated from human-induced mortality by Yellowstone National Park. Pumas in the western Montana Garnet Mountain system were exposed to greater human-induced mortality, which changed over the study due to the closure of a 915 km2 area to hunting. The NGYE’s population growth depended on inter-population movements, as did its ability to act as a source to the larger region. The heavily hunted Garnet area was a sink with a declining population until the hunting closure, after which it became a source with positive intrinsic growth and a 16× increase in emigration. We also examined the spatial and temporal characteristics of individual dispersal attributes (emigration, dispersal distance, establishment success) of subadult pumas (N = 126). Human-caused mortality was found to negatively impact all three dispersal components. Our results demonstrate the influence of human-induced mortality on not only within population vital rates, but also inter-population vital rates, affecting the magnitude and mechanisms of local population’s contribution to the larger metapopulation.
Evaluating mortality rates with a novel integrated framework for nonmonogamous species.
Tenan, Simone; Iemma, Aaron; Bragalanti, Natalia; Pedrini, Paolo; De Barba, Marta; Randi, Ettore; Groff, Claudio; Genovart, Meritxell
2016-12-01
The conservation of wildlife requires management based on quantitative evidence, and especially for large carnivores, unraveling cause-specific mortalities and understanding their impact on population dynamics is crucial. Acquiring this knowledge is challenging because it is difficult to obtain robust long-term data sets on endangered populations and, usually, data are collected through diverse sampling strategies. Integrated population models (IPMs) offer a way to integrate data generated through different processes. However, IPMs are female-based models that cannot account for mate availability, and this feature limits their applicability to monogamous species only. We extended classical IPMs to a two-sex framework that allows investigation of population dynamics and quantification of cause-specific mortality rates in nonmonogamous species. We illustrated our approach by simultaneously modeling different types of data from a reintroduced, unhunted brown bear (Ursus arctos) population living in an area with a dense human population. In a population mainly driven by adult survival, we estimated that on average 11% of cubs and 61% of adults died from human-related causes. Although the population is currently not at risk, adult survival and thus population dynamics are driven by anthropogenic mortality. Given the recent increase of human-bear conflicts in the area, removal of individuals for management purposes and through poaching may increase, reversing the positive population growth rate. Our approach can be generalized to other species affected by cause-specific mortality and will be useful to inform conservation decisions for other nonmonogamous species, such as most large carnivores, for which data are scarce and diverse and thus data integration is highly desirable. © 2016 Society for Conservation Biology.
Gude, J.A.; Mitchell, M.S.; Russell, R.E.; Sime, C.A.; Bangs, E.E.; Mech, L.D.; Ream, R.R.
2012-01-01
Reliable analyses can help wildlife managers make good decisions, which are particularly critical for controversial decisions such as wolf (Canis lupus) harvest. Creel and Rotella (2010) recently predicted substantial population declines in Montana wolf populations due to harvest, in contrast to predictions made by Montana Fish, Wildlife and Parks (MFWP). We replicated their analyses considering only those years in which field monitoring was consistent, and we considered the effect of annual variation in recruitment on wolf population growth. Rather than assuming constant rates, we used model selection methods to evaluate and incorporate models of factors driving recruitment and human-caused mortality rates in wolf populations in the Northern Rocky Mountains. Using data from 27 area-years of intensive wolf monitoring, we show that variation in both recruitment and human-caused mortality affect annual wolf population growth rates and that human-caused mortality rates have increased with the sizes of wolf populations. We document that recruitment rates have decreased over time, and we speculate that rates have decreased with increasing population sizes and/or that the ability of current field resources to document recruitment rates has recently become less successful as the number of wolves in the region has increased. Estimates of positive wolf population growth in Montana from our top models are consistent with field observations and estimates previously made by MFWP for 2008-2010, whereas the predictions for declining wolf populations of Creel and Rotella (2010) are not. Familiarity with limitations of raw data, obtained first-hand or through consultation with scientists who collected the data, helps generate more reliable inferences and conclusions in analyses of publicly available datasets. Additionally, development of efficient monitoring methods for wolves is a pressing need, so that analyses such as ours will be possible in future years when fewer resources will be available for monitoring. ?? 2011 The Wildlife Society. Copyright ?? The Wildlife Society, 2011.
AMPHIBIAN DECLINE, ULTRAVIOLET RADIATION AND LOCAL POPULATION ADAPTATION
Amphibian population declines have been noted on both local and global scales. Causes for these declines are unknown although many hypotheses have been offered. In areas adjacent to human development, loss of habitat is a fairly well accepted cause. However in isolated, seemingl...
J. Castro-Prieto; S. Martinuzzi; V.C. Radeloff; D.P. Helmers; M. Quiñones; W.A. Gould
2017-01-01
Increasing residential development around protected areas is a major threat for protected areas worldwide, and human population growth is often the most important cause. However, population is decreasing in many regions as a result of socio-economic changes, and it is unclear how residential development around protected areas is affected in these situations. We...
Green, David S.; Levi, Taal
2018-01-01
Pacific martens (Martes caurina humboldtensis) in coastal forests of Oregon and northern California in the United States are rare and geographically isolated, prompting a petition for listing under the Endangered Species Act. If listed, regulations have the potential to influence land-use decisions on public and private lands, but no estimates of population size, density, or viability of remnant marten populations are available for evaluating their conservation status. We used GPS and VHF telemetry and spatial mark-resight to estimate home ranges, density, and population size of Pacific martens in the Oregon Dunes National Recreation Area, central coast Oregon, USA. We then estimated population viability at differing levels of human-caused mortality (e.g., vehicle mortality). Marten home ranges were small on average (females = 0.8 km2, males 1.5 km2) and density (1.13 martens/1 km2) was the highest reported for North American populations (M. caurina, M. americana). We estimated 71 adult martens (95% CRI [41–87]) across two subpopulations separated by a large barrier (Umpqua River). Using population viability analysis, extinction risk for a subpopulation of 30 martens, approximately the size of the subpopulation south of the Umpqua River, ranged from 32% to 99% with two or three annual human-caused mortalities within 30 years. Absent population expansion, limiting human-caused mortalities will likely have the greatest conservation impact. PMID:29637018
Compensatory mortality in a recovering top carnivore: wolves in Wisconsin, USA (1979-2013).
Stenglein, Jennifer L; Wydeven, Adrian P; Van Deelen, Timothy R
2018-05-01
Populations of large terrestrial carnivores are in various stages of recovery worldwide and the question of whether there is compensation in mortality sources is relevant to conservation. Here, we show variation in Wisconsin wolf survival from 1979 to 2013 by jointly estimating the hazard of wolves' radio-telemetry ending (endpoint) and endpoint cause. In previous analyses, wolves lost to radio-telemetry follow-up (collar loss) were censored from analysis, thereby assuming collar loss was unconfounded with mortality. Our approach allowed us to explicitly estimate hazard due to collar loss and did not require censoring these records from analysis. We found mean annual survival was 76% and mean annual causes of mortality were illegal killing (9.4%), natural and unknown causes (9.5%), and other human-caused mortality such as hunting, vehicle collisions and lethal control (5.1%). Illegal killing and natural mortality were highest during winter, causing wolf survival to decrease relative to summer. Mortality was highest during early recovery and lowest during a period of sustained population growth. Wolves again experienced higher risk of human-caused mortality relative to natural mortality as wolves expanded into areas with more human activity. We detected partial compensation in human- and natural-caused mortality since 2004 as the population saturated more available habitat. Prior to 2004, we detected additivity in mortality sources. Assessments of wolf survival and cause of mortality rates and the finding of partial compensation in mortality sources will inform wolf conservation and management efforts by identifying sources and sinks, finding areas of conservation need, and assessing management zone delineation.
NASA Astrophysics Data System (ADS)
Dewi Siawanta, Shanti; Adi-Kusumo, Fajar; Irwan Endrayanto, Aluicius
2018-03-01
Malaria, which is caused by Plasmodium, is a common disease in tropical areas. There are three types of Plasmodium i.e. Plasmodium Vivax, Plasmodium Malariae, and Plasmodium Falciparum. The most dangerous cases of the Malaria are mainly caused by the Plasmodium Falciparum. One of the important characteristics for the Plasmodium infection is due to the immunity of erythrocyte that contains HbS (Haemoglobin Sickle-cell) genes. The individuals who has the HbS gene has better immunity against the disease. In this paper, we consider a model that shows the spread of malaria involving the interaction between the mosquitos population, the human who has HbS genes population and the human with normal gene population. We do some analytical and numerical simulation to study the basic reproduction ratio and the slow-fast dynamics of the phase-portrait. The slow dynamics in our model represents the response of the human population with HbS gene to the Malaria disease while the fast dynamics show the response of the human population with the normal gene to the disease. The slow and fast dynamics phenomena are due to the fact that the population of the individuals who have HbS gene is much smaller than the individuals who has normal genes.
Predicting Metapopulation Responses to Conservation in Human-Dominated Landscapes
Zachary S. Ladin; Vincent D' Amico; Jan M. Baetens; Roland R. Roth; W. Gregory Shriver
2016-01-01
Loss of habitat to urbanization is a primary cause of population declines as human-dominated landscapes expand at increasing rates. Understanding how the relative effects of different conservation strategies is important to slow population declines for species in urban landscapes. We studied the wood thrush Hylocichla mustelina, a declining forest-...
Human influence on the spatial structure of threatened Pacific salmon metapopulations
Aimee H. Fullerton; Steven T. Lindley; George R. Pess; Blake E. Feist; E. Ashley Steel; Paul McElhany
2011-01-01
To remain viable, populations must be resilient to both natural and human-caused environmental changes. We evaluated anthropogenic effects on spatial connections among populations of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) (designated as threatened under the U.S. Endangered Species Act) in the lower...
Code of Federal Regulations, 2012 CFR
2012-07-01
... this subpart. (f) Balanced indigenous population means an ecological community which: (1) Exhibits... Administrator, that the absence of a balanced indigenous population is caused solely by human perturbations...
Code of Federal Regulations, 2011 CFR
2011-07-01
... this subpart. (f) Balanced indigenous population means an ecological community which: (1) Exhibits... Administrator, that the absence of a balanced indigenous population is caused solely by human perturbations...
Code of Federal Regulations, 2013 CFR
2013-07-01
... this subpart. (f) Balanced indigenous population means an ecological community which: (1) Exhibits... Administrator, that the absence of a balanced indigenous population is caused solely by human perturbations...
Code of Federal Regulations, 2014 CFR
2014-07-01
... this subpart. (f) Balanced indigenous population means an ecological community which: (1) Exhibits... Administrator, that the absence of a balanced indigenous population is caused solely by human perturbations...
Code of Federal Regulations, 2010 CFR
2010-07-01
... this subpart. (f) Balanced indigenous population means an ecological community which: (1) Exhibits... Administrator, that the absence of a balanced indigenous population is caused solely by human perturbations...
Bat–man disease transmission: zoonotic pathogens from wildlife reservoirs to human populations
Allocati, N; Petrucci, A G; Di Giovanni, P; Masulli, M; Di Ilio, C; De Laurenzi, V
2016-01-01
Bats are natural reservoir hosts and sources of infection of several microorganisms, many of which cause severe human diseases. Because of contact between bats and other animals, including humans, the possibility exists for additional interspecies transmissions and resulting disease outbreaks. The purpose of this article is to supply an overview on the main pathogens isolated from bats that have the potential to cause disease in humans. PMID:27551536
Syphard, Alexandra D; Radeloff, Volker C; Hawbaker, Todd J; Stewart, Susan I
2009-06-01
Periodic wildfire is an important natural process in Mediterranean-climate ecosystems, but increasing fire recurrence threatens the fragile ecology of these regions. Because most fires are human-caused, we investigated how human population patterns affect fire frequency. Prior research in California suggests the relationship between population density and fire frequency is not linear. There are few human ignitions in areas with low population density, so fire frequency is low. As population density increases, human ignitions and fire frequency also increase, but beyond a density threshold, the relationship becomes negative as fuels become sparser and fire suppression resources are concentrated. We tested whether this hypothesis also applies to the other Mediterranean-climate ecosystems of the world. We used global satellite databases of population, fire activity, and land cover to evaluate the spatial relationship between humans and fire in the world's five Mediterranean-climate ecosystems. Both the mean and median population densities were consistently and substantially higher in areas with than without fire, but fire again peaked at intermediate population densities, which suggests that the spatial relationship is complex and nonlinear. Some land-cover types burned more frequently than expected, but no systematic differences were observed across the five regions. The consistent association between higher population densities and fire suggests that regardless of differences between land-cover types, natural fire regimes, or overall population, the presence of people in Mediterranean-climate regions strongly affects the frequency of fires; thus, population growth in areas now sparsely settled presents a conservation concern. Considering the sensitivity of plant species to repeated burning and the global conservation significance of Mediterranean-climate ecosystems, conservation planning needs to consider the human influence on fire frequency. Fine-scale spatial analysis of relationships between people and fire may help identify areas where increases in fire frequency will threaten ecologically valuable areas. ©2009 Society for Conservation Biology.
Human related mortality of birds in the United States
Banks, R.C.
1979-01-01
Modern man serves as both a direct and an indirect cause of the death of birds. In the early 1970's, human activity was responsible for the death of approximately 196 million birds per year, or about 1.9% of the wild birds of the continental United States that died each year. Hunting was the largest direct mortality factor and accounted for about 61% of human related bird deaths. Control or prevention of avian depredations took about 1% of the total, and all research and propagation about 0.5%. Collision with man-made objects was the greatest indirect human cause of avian deaths. accounting for about 32% of the human related deaths. Pollution and poisoning caused the death of about 2% of the total. A relatively few species account for most of this mortality but continue to maintain large, harvestable populations, suggesting that the numbers of most bird species are essentially unaffected by the human activities discussed. Other activities of man that do not necessarily result in the death of birds but rather reduce reproductive potential are more likely to have long-term effects on avian populations.
Mamoshina, Polina; Kochetov, Kirill; Putin, Evgeny; Cortese, Franco; Aliper, Alexander; Lee, Won-Suk; Ahn, Sung-Min; Uhn, Lee; Skjodt, Neil; Kovalchuk, Olga; Scheibye-Knudsen, Morten; Zhavoronkov, Alex
2018-01-11
Accurate and physiologically meaningful biomarkers for human aging are key to assessing anti-aging therapies. Given ethnic differences in health, diet, lifestyle, behaviour, environmental exposures and even average rate of biological aging, it stands to reason that aging clocks trained on datasets obtained from specific ethnic populations are more likely to account for these potential confounding factors, resulting in an enhanced capacity to predict chronological age and quantify biological age. Here we present a deep learning-based hematological aging clock modeled using the large combined dataset of Canadian, South Korean and Eastern European population blood samples that show increased predictive accuracy in individual populations compared to population-specific hematologic aging clocks. The performance of models was also evaluated on publicly-available samples of the American population from the National Health and Nutrition Examination Survey (NHANES). In addition, we explored the association between age predicted by both population-specific and combined hematological clocks and all-cause mortality. Overall, this study suggests a) the population-specificity of aging patterns and b) hematologic clocks predicts all-cause mortality. Proposed models added to the freely available Aging.AI system allowing improved ability to assess human aging. © The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America.
Drastic population fluctuations explain the rapid extinction of the passenger pigeon.
Hung, Chih-Ming; Shaner, Pei-Jen L; Zink, Robert M; Liu, Wei-Chung; Chu, Te-Chin; Huang, Wen-San; Li, Shou-Hsien
2014-07-22
To assess the role of human disturbances in species' extinction requires an understanding of the species population history before human impact. The passenger pigeon was once the most abundant bird in the world, with a population size estimated at 3-5 billion in the 1800s; its abrupt extinction in 1914 raises the question of how such an abundant bird could have been driven to extinction in mere decades. Although human exploitation is often blamed, the role of natural population dynamics in the passenger pigeon's extinction remains unexplored. Applying high-throughput sequencing technologies to obtain sequences from most of the genome, we calculated that the passenger pigeon's effective population size throughout the last million years was persistently about 1/10,000 of the 1800's estimated number of individuals, a ratio 1,000-times lower than typically found. This result suggests that the passenger pigeon was not always super abundant but experienced dramatic population fluctuations, resembling those of an "outbreak" species. Ecological niche models supported inference of drastic changes in the extent of its breeding range over the last glacial-interglacial cycle. An estimate of acorn-based carrying capacity during the past 21,000 y showed great year-to-year variations. Based on our results, we hypothesize that ecological conditions that dramatically reduced population size under natural conditions could have interacted with human exploitation in causing the passenger pigeon's rapid demise. Our study illustrates that even species as abundant as the passenger pigeon can be vulnerable to human threats if they are subject to dramatic population fluctuations, and provides a new perspective on the greatest human-caused extinction in recorded history.
Environmental geology and hydrology
NASA Astrophysics Data System (ADS)
Nakić, Zoran; Mileusnić, Marta; Pavlić, Krešimir; Kovač, Zoran
2017-10-01
Environmental geology is scientific discipline dealing with the interactions between humans and the geologic environment. Many natural hazards, which have great impact on humans and their environment, are caused by geological settings. On the other hand, human activities have great impact on the physical environment, especially in the last decades due to dramatic human population growth. Natural disasters often hit densely populated areas causing tremendous death toll and material damage. Demand for resources enhanced remarkably, as well as waste production. Exploitation of mineral resources deteriorate huge areas of land, produce enormous mine waste and pollute soil, water and air. Environmental geology is a broad discipline and only selected themes will be presented in the following subchapters: (1) floods as natural hazard, (2) water as geological resource and (3) the mining and mineral processing as types of human activities dealing with geological materials that affect the environment and human health.
Pickell, Paul D; Coops, Nicholas C; Ferster, Colin J; Bater, Christopher W; Blouin, Karen D; Flannigan, Mike D; Zhang, Jinkai
2017-10-27
Spring represents the peak of human-caused wildfire events in populated boreal forests, resulting in catastrophic loss of property and human life. Human-caused wildfire risk is anticipated to increase in northern forests as fuels become drier, on average, under warming climate scenarios and as population density increases within formerly remote regions. We investigated springtime human-caused wildfire risk derived from satellite-observed vegetation greenness in the early part of the growing season, a period of increased ignition and wildfire spread potential from snow melt to vegetation green-up with the aim of developing an early warning wildfire risk system. The initial system was developed for 392,856 km 2 of forested lands with satellite observations available prior to the start of the official wildfire season and predicted peak human-caused wildfire activity with 10-day accuracy for 76% of wildfire-protected lands by March 22. The early warning system could have significant utility as a cost-effective solution for wildfire managers to prioritize the deployment of wildfire protection resources in wildfire-prone landscapes across boreal-dominated ecosystems of North America, Europe, and Russia using open access Earth observations.
Evaluating the Human Damage of Tsunami at Each Time Frame in Aggregate Units Based on GPS data
NASA Astrophysics Data System (ADS)
Ogawa, Y.; Akiyama, Y.; Kanasugi, H.; Shibasaki, R.; Kaneda, H.
2016-06-01
Assessments of the human damage caused by the tsunami are required in order to consider disaster prevention at such a regional level. Hence, there is an increasing need for the assessments of human damage caused by earthquakes. However, damage assessments in japan currently usually rely on static population distribution data, such as statistical night time population data obtained from national census surveys. Therefore, human damage estimation that take into consideration time frames have not been assessed yet. With these backgrounds, the objectives of this study are: to develop a method for estimating the population distribution of the for each time frame, based on location positioning data observed with mass GPS loggers of mobile phones, to use a evacuation and casualties models for evaluating human damage due to the tsunami, and evaluate each time frame by using the data developed in the first objective, and 3) to discuss the factors which cause the differences in human damage for each time frame. By visualizing the results, we clarified the differences in damage depending on time frame, day and area. As this study enables us to assess damage for any time frame in and high resolution, it will be useful to consider provision for various situations when an earthquake may hit, such as during commuting hours or working hours and week day or holiday.
[The key problems in the population exposure assessment of hazardous chemicals accidents].
Pan, L J; Liu, F P; Zhang, X; Bai, X T; Shi, X M
2016-07-06
Serious accidents of hazardous chemicals can cause a variety of acute or chronic impairment in human health. The effects of hazardous chemicals on human health can be identified by carrying on population exposure assessment. Through analyzing the domestic and overseas population exposure assessment cases related to hazardous chemicals accidents, we summarized that the base and key of the population exposure assessment were to identify the characteristics of the chemicals , delimit the area and the population exposed to the chemicals, and collect the data of the monitored chemicals and the population health in the polluted area.
Frog decline, frog malformations, and a comparison of frog and human health.
Cohen, M M
2001-11-22
The decline in frog populations and the increase in the frequency of frog malformations are discussed. Topics considered for analysis include chytridiomycosis, retinoids, UV-B radiation, chemical contaminants, environmental threats, introduced invasive species and predation, unsustainable use, and enigmatic decline. Care must be taken to distinguish between hypotheses, laboratory experiments, and the findings in feral frog populations. Clearly, the causes of population decline and malformations are heterogeneous. The subject of frogs and humans is addressed under three subheadings: the importance of frogs to human societies, medical implications of frog studies, and a comparison of frog and human disease factors. Copyright 2001 Wiley-Liss, Inc.
Dog ownership and all-cause mortality in a population cohort in Norway: The HUNT study.
Torske, Magnhild Oust; Krokstad, Steinar; Stamatakis, Emmanuel; Bauman, Adrian
2017-01-01
There has been increased interest in human-animal interactions and their possible effects on human health. Some of this research has focused on human physical activity levels, mediated through increased dog walking. Much of the reported research has been cross sectional, and very few epidemiological studies have examined the association between dog ownership and mortality in populations. We used data from the Norwegian county population-based Nord-Trøndelag HUNT Study (HUNT2, 1995-1997). Cox proportional hazards models were fitted to analyse the relationship between dog ownership and all-cause mortality. The median follow-up time was 18.5 years and the maximum follow-up time was 19.7 years. In this population, dog owners were no more physically active than non-dog owners, both groups reporting a total of just over 3 hours/week of light and vigorous activity. Dog owners (n = 25,031, with 1,587 deaths during follow-up; 504,017 person-years of time at risk) had virtually the same hazard of dying as non-dog owners (Hazard ratio 1.00, 95% CI 0.91-1.09). We found no evidence for an association between the presence of a dog in the household and all-cause mortality or physical activity levels in this Norwegian population. Further epidemiological research is needed to clarify this relationship, as methodological limitations and an active Norwegian population sample means that generalizable evidence is not yet clear on dog ownership and mortality.
The common zoonotic protozoal diseases causing abortion.
Shaapan, Raafat Mohamed
2016-12-01
Toxoplasmosis, neosporosis, sarcosporidiosis (sarcocystosis) and trypanosomiasis are the common zoonotic protozoal diseases causing abortion which caused by single-celled protozoan parasites; Toxoplasma gondii, Neospora caninum , Sarcocystis spp and Trypanosoma evansi, respectively. Toxoplasmosis is generally considered the most important disease that causing abortion of both pregnant women and different female animals throughout the world, about third of human being population had antibodies against T. gondii . The infection can pass via placenta, causing encephalitis, chorio-retinitis, mental retardation and loss of vision in congenitally-infected children and stillbirth or mummification of the aborted fetuses of livestock. Neosporosis is recognized as a major cause of serious abortion in varieties of wild and domestic animals around the world particularly cattle, the disease cause serious economic losses among dairy and beef cattle due to decrease in milk and meat production. While unlike toxoplasmosis, neosporosis is not recognized as a human pathogen and evidence to date shows that neosporosis is only detected by serology in the human population. Sarcosporidiosis also can cause abortion in animals particularly cattle, buffaloes and sheep with acute infection through high dose of infection with sarcocysts. On the other hand, humans have been reported as final and intermediate host for sarcosporidiosis but not represent a serious health problem. Trypanosomiasis by T. evansi cause dangerous infection among domestic animals in tropical and subtropical areas. Several cases of abortion had been recorded in cattle and buffaloes infected with T. evansi while, a single case of human infection was reported in India. Trichomoniasis and babesiosis abortion occurs with non-zoonotic Trichomonas and Babesia species while the zoonotic species had not been incriminated in induction of abortion in both animals and man. The current review article concluded that there is still need of wide scope for evaluation of the zoonotic impact and control of these diseases.
Guide to Population Issues for Students and Teachers [and] Curriculum Guide.
ERIC Educational Resources Information Center
Facing the Future, Lopez Island, WA.
As the world grapples with increasing environmental, social, and security problems, population is rarely considered a cause or contributing factor. The relationship of population to the human condition, and to the condition of the Earth, is often subtle and complex. But population growth affects almost every aspect of life from education to…
Analysis of a model of gambiense sleeping sickness in humans and cattle.
Ndondo, A M; Munganga, J M W; Mwambakana, J N; Saad-Roy, C M; van den Driessche, P; Walo, R O
2016-01-01
Human African Trypanosomiasis (HAT) and Nagana in cattle, commonly called sleeping sickness, is caused by trypanosome protozoa transmitted by bites of infected tsetse flies. We present a deterministic model for the transmission of HAT caused by Trypanosoma brucei gambiense between human hosts, cattle hosts and tsetse flies. The model takes into account the growth of the tsetse fly, from its larval stage to the adult stage. Disease in the tsetse fly population is modeled by three compartments, and both the human and cattle populations are modeled by four compartments incorporating the two stages of HAT. We provide a rigorous derivation of the basic reproduction number R0. For R0 < 1, the disease free equilibrium is globally asymptotically stable, thus HAT dies out; whereas (assuming no return to susceptibility) for R0 >1, HAT persists. Elasticity indices for R0 with respect to different parameters are calculated with baseline parameter values appropriate for HAT in West Africa; indicating parameters that are important for control strategies to bring R0 below 1. Numerical simulations with R0 > 1 show values for the infected populations at the endemic equilibrium, and indicate that with certain parameter values, HAT could not persist in the human population in the absence of cattle.
Gray wolf mortality patterns in Wisconsin from 1979 to 2012.
Treves, Adrian; Langenberg, Julia A; López-Bao, José V; Rabenhorst, Mark F
2017-02-08
Starting in the 1970s, many populations of large-bodied mammalian carnivores began to recover from centuries of human-caused eradication and habitat destruction. The recovery of several such populations has since slowed or reversed due to mortality caused by humans. Illegal killing (poaching) is a primary cause of death in many carnivore populations. Law enforcement agencies face difficulties in preventing poaching and scientists face challenges in measuring it. Both challenges are exacerbated when evidence is concealed or ignored. We present data on deaths of 937 Wisconsin gray wolves ( Canis lupus ) from October 1979 to April 2012 during a period in which wolves were recolonizing historic range mainly under federal government protection. We found and partially remedied sampling and measurement biases in the source data by reexamining necropsy reports and reconstructing the numbers and causes of some wolf deaths that were never reported. From 431 deaths and disappearances of radiocollared wolves aged > 7.5 months, we estimated human causes accounted for two-thirds of reported and reconstructed deaths, including poaching in 39-45%, vehicle collisions in 13%, legal killing by state agents in 6%, and nonhuman causes in 36-42%. Our estimate of poaching remained an underestimate because of persistent sources of uncertainty and systematic underreporting. Unreported deaths accounted for over two-thirds of all mortality annually among wolves > 7.5 months old. One-half of all poached wolves went unreported, or > 80% of poached wolves not being monitored by radiotelemetry went unreported. The annual mortality rate averaged 18% ± 10% for monitored wolves but 47% ± 19% for unmonitored wolves. That difference appeared to be due largely to radiocollaring being concentrated in the core areas of wolf range, as well as higher rates of human-caused mortality in the periphery of wolf range. We detected an average 4% decline in wolf population growth in the last 5 years of the study. Because our estimates of poaching risk and overall mortality rate exceeded official estimates after 2012, we present all data for transparency and replication. More recent additions of public hunting quotas after 2012 appear unsustainable without effective curtailment of poaching. Effective antipoaching enforcement will require more accurate estimates of poaching rate, location, and timing than currently available. Independent scientific review of methods and data will improve antipoaching policies for large carnivore conservation, especially for controversial species facing high levels of human-induced mortality.
Reimer, Aleisha; Verghese, Bindhu; Lok, Mei; Ziegler, Jennifer; Farber, Jeffrey; Pagotto, Franco; Graham, Morag; Nadon, Celine A.
2012-01-01
Human listeriosis outbreaks in Canada have been predominantly caused by serotype 1/2a isolates with highly similar pulsed-field gel electrophoresis (PFGE) patterns. Multilocus sequence typing (MLST) and multi-virulence-locus sequence typing (MVLST) each identified a diverse population of Listeria monocytogenes isolates, and within that, both methods had congruent subtypes that substantiated a predominant clone (clonal complex 8; virulence type 59; proposed epidemic clone 5 [ECV]) that has been causing human illness across Canada for more than 2 decades. PMID:22337989
Population Demographic History Can Cause the Appearance of Recombination Hotspots
Johnston, Henry R.; Cutler, David J.
2012-01-01
Although the prevailing view among geneticists suggests that recombination hotspots exist ubiquitously across the human genome, there is only limited experimental evidence from a few genomic regions to support the generality of this claim. A small number of true recombination hotspots are well supported experimentally, but the vast majority of hotspots have been identified on the basis of population genetic inferences from the patterns of linkage disequilibrium (LD) seen in the human population. These inferences are made assuming a particular model of human history, and one of the assumptions of that model is that the effective population size of humans has remained constant throughout our history. Our results show that relaxation of the constant population size assumption can create LD and variation patterns that are qualitatively and quantitatively similar to human populations without any need to invoke localized hotspots of recombination. In other words, apparent recombination hotspots could be an artifact of variable population size over time. Several lines of evidence suggest that the vast majority of hotspots identified on the basis of LD information are unlikely to have elevated recombination rates. PMID:22560089
Population growth and consumption.
Chalkley, K
1997-04-01
The relationship between population growth, resource consumption, and environmental degradation is complex. The rise in "greenhouse gases" that will cause climatic change is clearly due to human activity, and pollutants are often concentrated in densely populated areas. However, even an area with a negative population growth, such as Russia, can experience severe environmental degradation due to poor management. Consumption patterns have the most effect on ozone depletion, while population growth threatens biodiversity of and within species through the destruction of ecosystems. Migration joins population growth and social factors, such as land inequality, as major causes of deforestation, and global demand for water is expected to increase faster than the rate of population growth. Coastal development and over-fishing threaten to deplete the oceans, while soil quality is threatened by inappropriate land use. Estimates of the earth's carrying capacity range from less than 3 billion to more than 44 billion people, indicating how difficult it is to assess this figure. Development efforts throughout the world may lead to human gains that will ultimately be negated by environmental losses. These factors have led to growing support for environmentally sustainable development.
ERIC Educational Resources Information Center
Murphy, Elaine M.; Long, Alison T.
This course outline suggests materials and learning activities on the interrelated causes and consequences of population growth and other population matters. The document describes 15 class sessions which integrate information for sociology, anthropology, psychology, biology, animal behavior, and education. Topics include the history of human…
Concern With Environmental Deterioration and Attitudes Toward Population Limitation
ERIC Educational Resources Information Center
Barnett, Larry D.
1970-01-01
Analysis of Gallup Poll data of Junuary 1969 reveals weak association between concern about environmental deterioration and the recognition of need for eventual limitation of human population. Suggests that to increase favorable attitudes to population control, role of overpopulation in causing environmental deterioration needs to be presented to…
Genetic Variation and Adaptation in Africa: Implications for Human Evolution and Disease
Gomez, Felicia; Hirbo, Jibril; Tishkoff, Sarah A.
2014-01-01
Because modern humans originated in Africa and have adapted to diverse environments, African populations have high levels of genetic and phenotypic diversity. Thus, genomic studies of diverse African ethnic groups are essential for understanding human evolutionary history and how this leads to differential disease risk in all humans. Comparative studies of genetic diversity within and between African ethnic groups creates an opportunity to reconstruct some of the earliest events in human population history and are useful for identifying patterns of genetic variation that have been influenced by recent natural selection. Here we describe what is currently known about genetic variation and evolutionary history of diverse African ethnic groups. We also describe examples of recent natural selection in African genomes and how these data are informative for understanding the frequency of many genetic traits, including those that cause disease susceptibility in African populations and populations of recent African descent. PMID:24984772
Sola schola et sanitate: human capital as the root cause and priority for international development?
Lutz, Wolfgang
2009-01-01
This paper summarizes new scientific evidence supporting the hypothesis that among the many factors contributing to international development, the combination of education and health stands out as a root cause on which other dimensions of development depend. Much of this recent analysis is based on new reconstructions and projections of populations by age, sex and four levels of educational attainment for more than 120 countries using the demographic method of multi-state population dynamics. It also refers to a series of systems analytical population–development–environment case studies that comprehensively assess the role of population and education factors relative to other factors in the struggle for sustainable development. The paper also claims that most concerns about the consequences of population trends are in fact concerns about human capital, and that only by adding the ‘quality’ dimension of education to the traditionally narrow focus on size and age structure can some of the long-standing population controversies be resolved. PMID:19770154
Dog ownership and all-cause mortality in a population cohort in Norway: The HUNT study
Krokstad, Steinar; Stamatakis, Emmanuel; Bauman, Adrian
2017-01-01
Objective There has been increased interest in human-animal interactions and their possible effects on human health. Some of this research has focused on human physical activity levels, mediated through increased dog walking. Much of the reported research has been cross sectional, and very few epidemiological studies have examined the association between dog ownership and mortality in populations. Methods We used data from the Norwegian county population-based Nord-Trøndelag HUNT Study (HUNT2, 1995–1997). Cox proportional hazards models were fitted to analyse the relationship between dog ownership and all-cause mortality. The median follow-up time was 18.5 years and the maximum follow-up time was 19.7 years. Results In this population, dog owners were no more physically active than non-dog owners, both groups reporting a total of just over 3 hours/week of light and vigorous activity. Dog owners (n = 25,031, with 1,587 deaths during follow-up; 504,017 person-years of time at risk) had virtually the same hazard of dying as non-dog owners (Hazard ratio 1.00, 95% CI 0.91–1.09). Conclusions We found no evidence for an association between the presence of a dog in the household and all-cause mortality or physical activity levels in this Norwegian population. Further epidemiological research is needed to clarify this relationship, as methodological limitations and an active Norwegian population sample means that generalizable evidence is not yet clear on dog ownership and mortality. PMID:28662069
Comparative Population Genomics Analysis of the Mammalian Fungal Pathogen Pneumocystis.
Cissé, Ousmane H; Ma, Liang; Wei Huang, Da; Khil, Pavel P; Dekker, John P; Kutty, Geetha; Bishop, Lisa; Liu, Yueqin; Deng, Xilong; Hauser, Philippe M; Pagni, Marco; Hirsch, Vanessa; Lempicki, Richard A; Stajich, Jason E; Cuomo, Christina A; Kovacs, Joseph A
2018-05-08
Pneumocystis species are opportunistic mammalian pathogens that cause severe pneumonia in immunocompromised individuals. These fungi are highly host specific and uncultivable in vitro Human Pneumocystis infections present major challenges because of a limited therapeutic arsenal and the rise of drug resistance. To investigate the diversity and demographic history of natural populations of Pneumocystis infecting humans, rats, and mice, we performed whole-genome and large-scale multilocus sequencing of infected tissues collected in various geographic locations. Here, we detected reduced levels of recombination and variations in historical demography, which shape the global population structures. We report estimates of evolutionary rates, levels of genetic diversity, and population sizes. Molecular clock estimates indicate that Pneumocystis species diverged before their hosts, while the asynchronous timing of population declines suggests host shifts. Our results have uncovered complex patterns of genetic variation influenced by multiple factors that shaped the adaptation of Pneumocystis populations during their spread across mammals. IMPORTANCE Understanding how natural pathogen populations evolve and identifying the determinants of genetic variation are central issues in evolutionary biology. Pneumocystis , a fungal pathogen which infects mammals exclusively, provides opportunities to explore these issues. In humans, Pneumocystis can cause a life-threatening pneumonia in immunosuppressed individuals. In analysis of different Pneumocystis species infecting humans, rats, and mice, we found that there are high infection rates and that natural populations maintain a high level of genetic variation despite low levels of recombination. We found no evidence of population structuring by geography. Our comparisons of the times of divergence of these species to their respective hosts suggest that Pneumocystis may have undergone recent host shifts. The results demonstrate that Pneumocystis strains are widely disseminated geographically and provide a new understanding of the evolution of these pathogens.
Status of Epstein-Barr Virus Coinfection with Helicobacter pylori in Gastric Cancer
Singh, Shyam
2017-01-01
Epstein-Barr virus is a ubiquitous human herpesvirus whose primary infection causes mononucleosis, Burkett's lymphoma, nasopharyngeal carcinoma, autoimmune diseases, and gastric cancer (GC). The persistent infection causes malignancies in lymph and epithelial cells. Helicobacter pylori causes gastritis in human with chronic inflammation. This chronic inflammation is thought to be the cause of genomic instability. About 45%-word population have a probability of having both pathogens, namely, H. pylori and EBV. Approximately 180 per hundred thousand population is developing GC along with many gastric abnormalities. This makes GC the third leading cause of cancer-related death worldwide. Although lots of research are carried out individually for EBV and H. pylori, still there are very few reports available on coinfection of both pathogens. Recent studies suggested that EBV and H. pylori coinfection increases the occurrence of GC as well as the early age of GC detection comparing to individual infection. The aim of this review is to present status on coinfection of both pathogens and their association with GC. PMID:28421114
Møller, Anders Pape; Samia, Diogo S. M.; Weston, Mike A.; Guay, Patrick-Jean; Blumstein, Daniel T.
2014-01-01
Background All organisms may be affected by humans' increasing impact on Earth, but there are many potential drivers of population trends and the relative importance of each remains largely unknown. The causes of spatial patterns in population trends and their relationship with animal responses to human proximity are even less known. Methodology/Principal Finding We investigated the relationship between population trends of 193 species of bird in North America, Australia and Europe and flight initiation distance (FID); the distance at which birds take flight when approached by a human. While there is an expected negative relationship between population trend and FID in Australia and Europe, we found the inverse relationship for North American birds; thus FID cannot be used as a universal predictor of vulnerability of birds. However, the analysis of the joint explanatory ability of multiple drivers (farmland breeding habitat, pole-most breeding latitude, migratory habit, FID) effects on population status replicated previously reported strong effects of farmland breeding habitat (an effect apparently driven mostly by European birds), as well as strong effects of FID, body size, migratory habit and continent. Farmland birds are generally declining. Conclusions/Significance Flight initiation distance is related to population trends in a way that differs among continents opening new research possibilities concerning the causes of geographic differences in patterns of anti-predator behavior. PMID:25226165
Human and Helicobacter pylori coevolution shapes the risk of gastric disease.
Kodaman, Nuri; Pazos, Alvaro; Schneider, Barbara G; Piazuelo, M Blanca; Mera, Robertino; Sobota, Rafal S; Sicinschi, Liviu A; Shaffer, Carrie L; Romero-Gallo, Judith; de Sablet, Thibaut; Harder, Reed H; Bravo, Luis E; Peek, Richard M; Wilson, Keith T; Cover, Timothy L; Williams, Scott M; Correa, Pelayo
2014-01-28
Helicobacter pylori is the principal cause of gastric cancer, the second leading cause of cancer mortality worldwide. However, H. pylori prevalence generally does not predict cancer incidence. To determine whether coevolution between host and pathogen influences disease risk, we examined the association between the severity of gastric lesions and patterns of genomic variation in matched human and H. pylori samples. Patients were recruited from two geographically distinct Colombian populations with significantly different incidences of gastric cancer, but virtually identical prevalence of H. pylori infection. All H. pylori isolates contained the genetic signatures of multiple ancestries, with an ancestral African cluster predominating in a low-risk, coastal population and a European cluster in a high-risk, mountain population. The human ancestry of the biopsied individuals also varied with geography, with mostly African ancestry in the coastal region (58%), and mostly Amerindian ancestry in the mountain region (67%). The interaction between the host and pathogen ancestries completely accounted for the difference in the severity of gastric lesions in the two regions of Colombia. In particular, African H. pylori ancestry was relatively benign in humans of African ancestry but was deleterious in individuals with substantial Amerindian ancestry. Thus, coevolution likely modulated disease risk, and the disruption of coevolved human and H. pylori genomes can explain the high incidence of gastric disease in the mountain population.
Long-Distance Dispersal Shaped Patterns of Human Genetic Diversity in Eurasia
Alves, Isabel; Arenas, Miguel; Currat, Mathias; Sramkova Hanulova, Anna; Sousa, Vitor C.; Ray, Nicolas; Excoffier, Laurent
2016-01-01
Most previous attempts at reconstructing the past history of human populations did not explicitly take geography into account or considered very simple scenarios of migration and ignored environmental information. However, it is likely that the last glacial maximum (LGM) affected the demography and the range of many species, including our own. Moreover, long-distance dispersal (LDD) may have been an important component of human migrations, allowing fast colonization of new territories and preserving high levels of genetic diversity. Here, we use a high-quality microsatellite data set genotyped in 22 populations to estimate the posterior probabilities of several scenarios for the settlement of the Old World by modern humans. We considered models ranging from a simple spatial expansion to others including LDD and a LGM-induced range contraction, as well as Neolithic demographic expansions. We find that scenarios with LDD are much better supported by data than models without LDD. Nevertheless, we show evidence that LDD events to empty habitats were strongly prevented during the settlement of Eurasia. This unexpected absence of LDD ahead of the colonization wave front could have been caused by an Allee effect, either due to intrinsic causes such as an inbreeding depression built during the expansion or due to extrinsic causes such as direct competition with archaic humans. Overall, our results suggest only a relatively limited effect of the LGM contraction on current patterns of human diversity. This is in clear contrast with the major role of LDD migrations, which have potentially contributed to the intermingled genetic structure of Eurasian populations. PMID:26637555
Molecular survey of ITS1 spacer and Rickettsia infection in human flea, Pulex irritans.
Ghavami, Mohammad Bagher; Mirzadeh, Habibeh; Mohammadi, Jamshid; Fazaeli, Asghar
2018-05-01
The human flea is an important ectoparasite causing serious public health problems worldwide. Planning and monitoring the control programs against this vector require the knowledge of population structure and vector competence. This study was carried out to identify molecular structure of internal transcribed spacer 1 (ITS1) of ribosomal gene and its capability in the survey of Pulex irritans populations as well as to investigate Rickettsia infection in these populations. Flea samples were collected via human baits from animal farms in two districts of Zanjan Province, northwest of Iran. The ITS1 region and the partial Rickettsia gltA gene were amplified from the samples of human flea, and 30 amplicons were sequenced. The 1136 collected fleas consisted of 1079 (94.98%) P. irritans, 36 (3.17%) Ctenocephalides canis, and 21 (1.85%) Ctenocephalides felis. Molecular investigation of 182 human fleas detected the infection of Rickettsia sp. in 4.9%. The ITS1 region covered 957 bp and contained three tandem units of 98-99 bp, starting at positions 145, 245, and 331. Multiple alignments of ITS1 sequences showed single-nucleotide polymorphism at position 798, which caused the substitution of cytosine for adenine in the novel haplotype. High frequency of P. irritans and its Rickettsia infection requires the application of vector control measures, and full characterization of Rickettsia sp. and its potential to cause disease in humans. Regarding the consistency of ITS1 region and its ability to differentiate insect communities, further investigations are recommended to identify the role of selective factors in maintenance of this spacer.
Candolin, Ulrika; Nieminen, Anne; Nyman, Johanna
2014-01-01
Human-induced rapid environmental changes often cause behavioural alterations in animals. The consequences that these alterations in turn have for the viability of populations are, however, poorly known. We used a population of threespine sticklebacks Gasterosteus aculeatus in the Baltic Sea to investigate the consequences of behavioural responses to human-induced eutrophication for offspring production. The investigated population has been growing during the last decades, and one cause could be increased offspring production. We combined field-based surveys with laboratory-based experiments, and found that an enhanced growth of macroalgae relaxed agonistic interactions among males. This allowed more males to nest, improved hatching success, and increased the number of reproductive cycles that males completed. Thus, the behavioural responses were adaptive at the individual level and increased offspring production. However, a larger proportion of small males of low competitive ability reproduced in dense vegetation. As male size and dominance are heritable, this could influence the genetic composition of the offspring. Together with a higher number of offspring produced, this could influence natural selection and the rate of adaptation to the changing environment. Thus, behavioural responses to a rapid human-induced environmental change can influence offspring production, with potential consequences for population dynamics and evolutionary processes.
DEMOGRAPHY AND SPATIAL POPULATION STRUCTURE IN CALIFORNIA TIGER SALAMANDER
Although the causes of many amphibian declines remain mysterious, there is general agreement that human habitat alteration represents the greatest threat to amphibian populations. In January 2000 the US Fish and Wildlife Service proposed listing Santa Barbara County California Ti...
RISK ASSESSMENT AND MANAGEMENT OF ENVIRONMENTAL CADMIUM
Cadmium consumed in foods grown on soils contaminated by industrial Cd+Zn discharge has caused renal tubular dysfunction in
exposed humans in discrete situations. However, lack of understanding about environmental Cd has caused wide concern that general
populations may...
[Highly contagious diseases with human-to-human transmission].
Rybka, Aleš; Szanyi, Juraj; Kapla, Jaroslav; Plíšek, Stanislav
2012-12-01
Highly contagious diseases are caused by various biological agents that pose a risk to individuals and may have a potential for public health impact. They result in high mortality and morbidity rates, might cause public panic and therefore require special measures. The pathogens that can be easily disseminated or transmitted from person to person are the riskiest for clinicians (Ebola virus, Marburg virus, Lassa virus, Crimean-Congo hemorrhagic fever virus, Variola major, SARS virus and Yersinia pestis). Human-to-human transmission has not been confirmed for the other biological agents and therefore they pose a very low risk for population.
HexSim Networks: Spatial IBMs are no longer just for the birds
Legally protected animal populations are exposed to pesticides, the type and concentration of which vary extensively across space and time. Individuals from these populations are also simultaneously subjected to multiple other human-caused disturbance regimes such as landscape c...
Behavioural responses to human-induced environmental change.
Tuomainen, Ulla; Candolin, Ulrika
2011-08-01
The initial response of individuals to human-induced environmental change is often behavioural. This can improve the performance of individuals under sudden, large-scale perturbations and maintain viable populations. The response can also give additional time for genetic changes to arise and, hence, facilitate adaptation to new conditions. On the other hand, maladaptive responses, which reduce individual fitness, may occur when individuals encounter conditions that the population has not experienced during its evolutionary history, which can decrease population viability. A growing number of studies find human disturbances to induce behavioural responses, both directly and by altering factors that influence fitness. Common causes of behavioural responses are changes in the transmission of information, the concentration of endocrine disrupters, the availability of resources, the possibility of dispersal, and the abundance of interacting species. Frequent responses are alterations in habitat choice, movements, foraging, social behaviour and reproductive behaviour. Behavioural responses depend on the genetically determined reaction norm of the individuals, which evolves over generations. Populations first respond with individual behavioural plasticity, whereafter changes may arise through innovations and the social transmission of behavioural patterns within and across generations, and, finally, by evolution of the behavioural response over generations. Only a restricted number of species show behavioural adaptations that make them thrive in severely disturbed environments. Hence, rapid human-induced disturbances often decrease the diversity of native species, while facilitating the spread of invasive species with highly plastic behaviours. Consequently, behavioural responses to human-induced environmental change can have profound effects on the distribution, adaptation, speciation and extinction of populations and, hence, on biodiversity. A better understanding of the mechanisms of behavioural responses and their causes and consequences could improve our ability to predict the effects of human-induced environmental change on individual species and on biodiversity. © 2010 The Authors. Biological Reviews © 2010 Cambridge Philosophical Society.
Climatic Change and Human Evolution.
ERIC Educational Resources Information Center
Garratt, John R.
1995-01-01
Traces the history of the Earth over four billion years, and shows how climate has had an important role to play in the evolution of humans. Posits that the world's rapidly growing human population and its increasing use of energy is the cause of present-day changes in the concentrations of greenhouse gases in the atmosphere. (Author/JRH)
Gray wolf mortality patterns in Wisconsin from 1979 to 2012
Langenberg, Julia A.; López-Bao, José V.; Rabenhorst, Mark F.
2017-01-01
Abstract Starting in the 1970s, many populations of large-bodied mammalian carnivores began to recover from centuries of human-caused eradication and habitat destruction. The recovery of several such populations has since slowed or reversed due to mortality caused by humans. Illegal killing (poaching) is a primary cause of death in many carnivore populations. Law enforcement agencies face difficulties in preventing poaching and scientists face challenges in measuring it. Both challenges are exacerbated when evidence is concealed or ignored. We present data on deaths of 937 Wisconsin gray wolves (Canis lupus) from October 1979 to April 2012 during a period in which wolves were recolonizing historic range mainly under federal government protection. We found and partially remedied sampling and measurement biases in the source data by reexamining necropsy reports and reconstructing the numbers and causes of some wolf deaths that were never reported. From 431 deaths and disappearances of radiocollared wolves aged > 7.5 months, we estimated human causes accounted for two-thirds of reported and reconstructed deaths, including poaching in 39–45%, vehicle collisions in 13%, legal killing by state agents in 6%, and nonhuman causes in 36–42%. Our estimate of poaching remained an underestimate because of persistent sources of uncertainty and systematic underreporting. Unreported deaths accounted for over two-thirds of all mortality annually among wolves > 7.5 months old. One-half of all poached wolves went unreported, or > 80% of poached wolves not being monitored by radiotelemetry went unreported. The annual mortality rate averaged 18% ± 10% for monitored wolves but 47% ± 19% for unmonitored wolves. That difference appeared to be due largely to radiocollaring being concentrated in the core areas of wolf range, as well as higher rates of human-caused mortality in the periphery of wolf range. We detected an average 4% decline in wolf population growth in the last 5 years of the study. Because our estimates of poaching risk and overall mortality rate exceeded official estimates after 2012, we present all data for transparency and replication. More recent additions of public hunting quotas after 2012 appear unsustainable without effective curtailment of poaching. Effective antipoaching enforcement will require more accurate estimates of poaching rate, location, and timing than currently available. Independent scientific review of methods and data will improve antipoaching policies for large carnivore conservation, especially for controversial species facing high levels of human-induced mortality. PMID:29674782
A review of the main driving factors of forest fire ignition over Europe.
Ganteaume, Anne; Camia, Andrea; Jappiot, Marielle; San-Miguel-Ayanz, Jesus; Long-Fournel, Marlène; Lampin, Corinne
2013-03-01
Knowledge of the causes of forest fires, and of the main driving factors of ignition, is an indispensable step towards effective fire prevention policies. This study analyses the factors driving forest fire ignition in the Mediterranean region including the most common human and environmental factors used for modelling in the European context. Fire ignition factors are compared to spatial and temporal variations of fire occurrence in the region, then are compared to results obtained in other areas of the world, with a special focus on North America (US and Canada) where a significant number of studies has been carried out on this topic. The causes of forest fires are varied and their distribution differs among countries, but may also differ spatially and temporally within the same country. In Europe, and especially in the Mediterranean basin, fires are mostly human-caused mainly due arson. The distance to transport networks and the distance to urban or recreation areas are among the most frequently used human factors in modelling exercises and the Wildland-Urban Interface is increasingly taken into account in the modelling of fire occurrence. Depending on the socio-economic context of the region concerned, factors such as the unemployment rate or variables linked to agricultural activity can explain the ignition of intentional and unintentional fires. Regarding environmental factors, those related to weather, fuel and topography are the most significant drivers of ignition of forest fires, especially in Mediterranean-type regions. For both human and lightning-caused fires, there is a geographical gradient of fire ignition, mainly due to variations in climate and fuel composition but also to population density for instance. The timing of fires depends on their causes. In populated areas, the timing of human-caused fires is closely linked to human activities and peaks in the afternoon whereas, in remote areas, the timing of lightning-caused fires is more linked to weather conditions and the season, with most such fires occurring in summer.
A Review of the Main Driving Factors of Forest Fire Ignition Over Europe
NASA Astrophysics Data System (ADS)
Ganteaume, Anne; Camia, Andrea; Jappiot, Marielle; San-Miguel-Ayanz, Jesus; Long-Fournel, Marlène; Lampin, Corinne
2013-03-01
Knowledge of the causes of forest fires, and of the main driving factors of ignition, is an indispensable step towards effective fire prevention policies. This study analyses the factors driving forest fire ignition in the Mediterranean region including the most common human and environmental factors used for modelling in the European context. Fire ignition factors are compared to spatial and temporal variations of fire occurrence in the region, then are compared to results obtained in other areas of the world, with a special focus on North America (US and Canada) where a significant number of studies has been carried out on this topic. The causes of forest fires are varied and their distribution differs among countries, but may also differ spatially and temporally within the same country. In Europe, and especially in the Mediterranean basin, fires are mostly human-caused mainly due arson. The distance to transport networks and the distance to urban or recreation areas are among the most frequently used human factors in modelling exercises and the Wildland-Urban Interface is increasingly taken into account in the modelling of fire occurrence. Depending on the socio-economic context of the region concerned, factors such as the unemployment rate or variables linked to agricultural activity can explain the ignition of intentional and unintentional fires. Regarding environmental factors, those related to weather, fuel and topography are the most significant drivers of ignition of forest fires, especially in Mediterranean-type regions. For both human and lightning-caused fires, there is a geographical gradient of fire ignition, mainly due to variations in climate and fuel composition but also to population density for instance. The timing of fires depends on their causes. In populated areas, the timing of human-caused fires is closely linked to human activities and peaks in the afternoon whereas, in remote areas, the timing of lightning-caused fires is more linked to weather conditions and the season, with most such fires occurring in summer.
Human Behavioral Contributions to Climate Change: Psychological and Contextual Drivers
ERIC Educational Resources Information Center
Swim, Janet K.; Clayton, Susan; Howard, George S.
2011-01-01
We are facing rapid changes in the global climate, and these changes are attributable to human behavior. Humans produce this global impact through our use of natural resources, multiplied by the vast increase in population seen in the past 50 to 100 years. Our goal in this article is to examine the underlying psychosocial causes of human impact,…
ERIC Educational Resources Information Center
Murphy, Elaine M.
This course outline suggests materials and learning activities on the interrelated causes and consequences of population growth and other population concerns. Designed to educate general college audiences, it is also intended for use as a preservice course for teachers. In addition, the course can be modified for high school students. The course…
Long-term shifts in the cyclicity of outbreaks of a forest-defoliating insect
Andrew J. Allstadt; Kyle J. Haynes; Andrew M. Liebhold; Derek M. Johnson
2013-01-01
Recent collapses of population cycles in several species highlight the mutable nature of population behavior as well as the potential role of human-induced environmental change in causing population dynamics to shift. We investigate changes in the cyclicity of gypsy moth (Lymantria dispar) outbreaks by applying wavelet analysis to an 86-year time...
Causes of childhood blindness in a developing country and an underdeveloped country.
Santos-Bueso, E; Dorronzoro-Ramírez, E; Gegúndez-Fernández, J A; Vinuesa-Silva, J M; Vinuesa-Silva, I; García-Sánchez, J
2015-05-01
The causes of childhood blindness depend on factors such as geographic location or the human development index of the populations under study. The main causes in developed countries are genetic and hereditary diseases, while infectious and contagious diseases, together with nutritional and vitamin deficiencies, are the main causes in underdeveloped countries (UDCs). Study of the causes of blindness among children admitted to a regional centre in Nador, Morocco, and among children in Mekele, Ethiopia. The study was carried out in collaboration with two non-governmental organizations based in Madrid, Spain. First, we worked with Fudación Adelias in June 2010, and with Proyecto Visión in October 2012. The study comprised a total of 27 children in Morocco and 85 in Ethiopia. The average age of the children was 10.92 and 6.94 years, respectively. The main causes of blindness in Morocco were hereditary pathologies (25.92%) and refractive errors (14.82%), although trauma (7.40%) and corneal disease (7.40%) are relevant. Among the children from Ethiopia, corneal disease (27.05%) and trauma (20%) were the main causes of blindness, while congenital and hereditary diseases had a lower prevalence (4.70%). The causes of blindness depend on the human development index of the populations under study. While corneal disease and trauma are the main causes observed in UDCs like Ethiopia, hereditary pathologies and refractive errors are the main causes within the Moroccan population studied. A mixed form can be observed in this country, as the cause of blindness found in developed countries, such as congenital and hereditary pathologies which are present alongside the causes normally found in LDCs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Eng, Christine L. P.; Tong, Joo Chuan; Tan, Tin Wee
2017-01-01
Influenza A viruses remain a significant health problem, especially when a novel subtype emerges from the avian population to cause severe outbreaks in humans. Zoonotic viruses arise from the animal population as a result of mutations and reassortments, giving rise to novel strains with the capability to evade the host species barrier and cause human infections. Despite progress in understanding interspecies transmission of influenza viruses, we are no closer to predicting zoonotic strains that can lead to an outbreak. We have previously discovered distinct host tropism protein signatures of avian, human and zoonotic influenza strains obtained from host tropism predictions on individual protein sequences. Here, we apply machine learning approaches on the signatures to build a computational model capable of predicting zoonotic strains. The zoonotic strain prediction model can classify avian, human or zoonotic strains with high accuracy, as well as providing an estimated zoonotic risk. This would therefore allow us to quickly determine if an influenza virus strain has the potential to be zoonotic using only protein sequences. The swift identification of potential zoonotic strains in the animal population using the zoonotic strain prediction model could provide us with an early indication of an imminent influenza outbreak. PMID:28587080
Eng, Christine L P; Tong, Joo Chuan; Tan, Tin Wee
2017-05-25
Influenza A viruses remain a significant health problem, especially when a novel subtype emerges from the avian population to cause severe outbreaks in humans. Zoonotic viruses arise from the animal population as a result of mutations and reassortments, giving rise to novel strains with the capability to evade the host species barrier and cause human infections. Despite progress in understanding interspecies transmission of influenza viruses, we are no closer to predicting zoonotic strains that can lead to an outbreak. We have previously discovered distinct host tropism protein signatures of avian, human and zoonotic influenza strains obtained from host tropism predictions on individual protein sequences. Here, we apply machine learning approaches on the signatures to build a computational model capable of predicting zoonotic strains. The zoonotic strain prediction model can classify avian, human or zoonotic strains with high accuracy, as well as providing an estimated zoonotic risk. This would therefore allow us to quickly determine if an influenza virus strain has the potential to be zoonotic using only protein sequences. The swift identification of potential zoonotic strains in the animal population using the zoonotic strain prediction model could provide us with an early indication of an imminent influenza outbreak.
Long-Distance Dispersal Shaped Patterns of Human Genetic Diversity in Eurasia.
Alves, Isabel; Arenas, Miguel; Currat, Mathias; Sramkova Hanulova, Anna; Sousa, Vitor C; Ray, Nicolas; Excoffier, Laurent
2016-04-01
Most previous attempts at reconstructing the past history of human populations did not explicitly take geography into account or considered very simple scenarios of migration and ignored environmental information. However, it is likely that the last glacial maximum (LGM) affected the demography and the range of many species, including our own. Moreover, long-distance dispersal (LDD) may have been an important component of human migrations, allowing fast colonization of new territories and preserving high levels of genetic diversity. Here, we use a high-quality microsatellite data set genotyped in 22 populations to estimate the posterior probabilities of several scenarios for the settlement of the Old World by modern humans. We considered models ranging from a simple spatial expansion to others including LDD and a LGM-induced range contraction, as well as Neolithic demographic expansions. We find that scenarios with LDD are much better supported by data than models without LDD. Nevertheless, we show evidence that LDD events to empty habitats were strongly prevented during the settlement of Eurasia. This unexpected absence of LDD ahead of the colonization wave front could have been caused by an Allee effect, either due to intrinsic causes such as an inbreeding depression built during the expansion or due to extrinsic causes such as direct competition with archaic humans. Overall, our results suggest only a relatively limited effect of the LGM contraction on current patterns of human diversity. This is in clear contrast with the major role of LDD migrations, which have potentially contributed to the intermingled genetic structure of Eurasian populations. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Model-based analysis of an outbreak of bubonic plague in Cairo in 1801
Whittles, Lilith K.; Hall, Ian
2017-01-01
Bubonic plague has caused three deadly pandemics in human history: from the mid-sixth to mid-eighth century, from the mid-fourteenth to the mid-eighteenth century and from the end of the nineteenth until the mid-twentieth century. Between the second and the third pandemics, plague was causing sporadic outbreaks in only a few countries in the Middle East, including Egypt. Little is known about this historical phase of plague, even though it represents the temporal, geographical and phylogenetic transition between the second and third pandemics. Here we analysed in detail an outbreak of plague that took place in Cairo in 1801, and for which epidemiological data are uniquely available thanks to the presence of medical officers accompanying the Napoleonic expedition into Egypt at that time. We propose a new stochastic model describing how bubonic plague outbreaks unfold in both rat and human populations, and perform Bayesian inference under this model using a particle Markov chain Monte Carlo. Rat carcasses were estimated to be infectious for approximately 4 days after death, which is in good agreement with local observations on the survival of infectious rat fleas. The estimated transmission rate between rats implies a basic reproduction number R0 of approximately 3, causing the collapse of the rat population in approximately 100 days. Simultaneously, the force of infection exerted by each infected rat carcass onto the human population increases progressively by more than an order of magnitude. We also considered human-to-human transmission via pneumonic plague or human specific vectors, but found this route to account for only a small fraction of cases and to be significantly below the threshold required to sustain an outbreak. PMID:28637916
Model-based analysis of an outbreak of bubonic plague in Cairo in 1801.
Didelot, Xavier; Whittles, Lilith K; Hall, Ian
2017-06-01
Bubonic plague has caused three deadly pandemics in human history: from the mid-sixth to mid-eighth century, from the mid-fourteenth to the mid-eighteenth century and from the end of the nineteenth until the mid-twentieth century. Between the second and the third pandemics, plague was causing sporadic outbreaks in only a few countries in the Middle East, including Egypt. Little is known about this historical phase of plague, even though it represents the temporal, geographical and phylogenetic transition between the second and third pandemics. Here we analysed in detail an outbreak of plague that took place in Cairo in 1801, and for which epidemiological data are uniquely available thanks to the presence of medical officers accompanying the Napoleonic expedition into Egypt at that time. We propose a new stochastic model describing how bubonic plague outbreaks unfold in both rat and human populations, and perform Bayesian inference under this model using a particle Markov chain Monte Carlo. Rat carcasses were estimated to be infectious for approximately 4 days after death, which is in good agreement with local observations on the survival of infectious rat fleas. The estimated transmission rate between rats implies a basic reproduction number R 0 of approximately 3, causing the collapse of the rat population in approximately 100 days. Simultaneously, the force of infection exerted by each infected rat carcass onto the human population increases progressively by more than an order of magnitude. We also considered human-to-human transmission via pneumonic plague or human specific vectors, but found this route to account for only a small fraction of cases and to be significantly below the threshold required to sustain an outbreak. © 2017 The Author(s).
Wang, Lu; Mariño-Ramírez, Leonardo
2017-01-01
Abstract Transposable element (TE) derived sequences are known to contribute to the regulation of the human genome. The majority of known TE-derived regulatory sequences correspond to relatively ancient insertions, which are fixed across human populations. The extent to which human genetic variation caused by recent TE activity leads to regulatory polymorphisms among populations has yet to be thoroughly explored. In this study, we searched for associations between polymorphic TE (polyTE) loci and human gene expression levels using an expression quantitative trait loci (eQTL) approach. We compared locus-specific polyTE insertion genotypes to B cell gene expression levels among 445 individuals from 5 human populations. Numerous human polyTE loci correspond to both cis and trans eQTL, and their regulatory effects are directly related to cell type-specific function in the immune system. PolyTE loci are associated with differences in expression between European and African population groups, and a single polyTE loci is indirectly associated with the expression of numerous genes via the regulation of the B cell-specific transcription factor PAX5. The polyTE-gene expression associations we found indicate that human TE genetic variation can have important phenotypic consequences. Our results reveal that TE-eQTL are involved in population-specific gene regulation as well as transcriptional network modification. PMID:27998931
Human ectoparasites and the spread of plague in Europe during the Second Pandemic
Krauer, Fabienne; Walløe, Lars; Bramanti, Barbara; Stenseth, Nils Chr.; Schmid, Boris V.
2018-01-01
Plague, caused by the bacterium Yersinia pestis, can spread through human populations by multiple transmission pathways. Today, most human plague cases are bubonic, caused by spillover of infected fleas from rodent epizootics, or pneumonic, caused by inhalation of infectious droplets. However, little is known about the historical spread of plague in Europe during the Second Pandemic (14–19th centuries), including the Black Death, which led to high mortality and recurrent epidemics for hundreds of years. Several studies have suggested that human ectoparasite vectors, such as human fleas (Pulex irritans) or body lice (Pediculus humanus humanus), caused the rapidly spreading epidemics. Here, we describe a compartmental model for plague transmission by a human ectoparasite vector. Using Bayesian inference, we found that this model fits mortality curves from nine outbreaks in Europe better than models for pneumonic or rodent transmission. Our results support that human ectoparasites were primary vectors for plague during the Second Pandemic, including the Black Death (1346–1353), ultimately challenging the assumption that plague in Europe was predominantly spread by rats. PMID:29339508
Human ectoparasites and the spread of plague in Europe during the Second Pandemic.
Dean, Katharine R; Krauer, Fabienne; Walløe, Lars; Lingjærde, Ole Christian; Bramanti, Barbara; Stenseth, Nils Chr; Schmid, Boris V
2018-02-06
Plague, caused by the bacterium Yersinia pestis , can spread through human populations by multiple transmission pathways. Today, most human plague cases are bubonic, caused by spillover of infected fleas from rodent epizootics, or pneumonic, caused by inhalation of infectious droplets. However, little is known about the historical spread of plague in Europe during the Second Pandemic (14-19th centuries), including the Black Death, which led to high mortality and recurrent epidemics for hundreds of years. Several studies have suggested that human ectoparasite vectors, such as human fleas ( Pulex irritans ) or body lice ( Pediculus humanus humanus ), caused the rapidly spreading epidemics. Here, we describe a compartmental model for plague transmission by a human ectoparasite vector. Using Bayesian inference, we found that this model fits mortality curves from nine outbreaks in Europe better than models for pneumonic or rodent transmission. Our results support that human ectoparasites were primary vectors for plague during the Second Pandemic, including the Black Death (1346-1353), ultimately challenging the assumption that plague in Europe was predominantly spread by rats. Copyright © 2018 the Author(s). Published by PNAS.
77 FR 3450 - Guidelines for Assessing Marine Mammal Stocks
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-24
... population trend model are available, such a model can be used to influence the uncertainty projections....) voluntarily submitted by the commenter may be publicly accessible. Do not submit Confidential Business... distribution and abundance of the stock, population growth rates and trends, estimates of annual human-caused...
Humans rather than climate the primary cause of Pleistocene megafaunal extinction in Australia
van der Kaars, Sander; Miller, Gifford H.; Turney, Chris S. M.; Cook, Ellyn J.; Nürnberg, Dirk; Schönfeld, Joachim; Kershaw, A. Peter; Lehman, Scott J.
2017-01-01
Environmental histories that span the last full glacial cycle and are representative of regional change in Australia are scarce, hampering assessment of environmental change preceding and concurrent with human dispersal on the continent ca. 47,000 years ago. Here we present a continuous 150,000-year record offshore south-western Australia and identify the timing of two critical late Pleistocene events: wide-scale ecosystem change and regional megafaunal population collapse. We establish that substantial changes in vegetation and fire regime occurred ∼70,000 years ago under a climate much drier than today. We record high levels of the dung fungus Sporormiella, a proxy for herbivore biomass, from 150,000 to 45,000 years ago, then a marked decline indicating megafaunal population collapse, from 45,000 to 43,100 years ago, placing the extinctions within 4,000 years of human dispersal across Australia. These findings rule out climate change, and implicate humans, as the primary extinction cause. PMID:28106043
Humans rather than climate the primary cause of Pleistocene megafaunal extinction in Australia.
van der Kaars, Sander; Miller, Gifford H; Turney, Chris S M; Cook, Ellyn J; Nürnberg, Dirk; Schönfeld, Joachim; Kershaw, A Peter; Lehman, Scott J
2017-01-20
Environmental histories that span the last full glacial cycle and are representative of regional change in Australia are scarce, hampering assessment of environmental change preceding and concurrent with human dispersal on the continent ca. 47,000 years ago. Here we present a continuous 150,000-year record offshore south-western Australia and identify the timing of two critical late Pleistocene events: wide-scale ecosystem change and regional megafaunal population collapse. We establish that substantial changes in vegetation and fire regime occurred ∼70,000 years ago under a climate much drier than today. We record high levels of the dung fungus Sporormiella, a proxy for herbivore biomass, from 150,000 to 45,000 years ago, then a marked decline indicating megafaunal population collapse, from 45,000 to 43,100 years ago, placing the extinctions within 4,000 years of human dispersal across Australia. These findings rule out climate change, and implicate humans, as the primary extinction cause.
Human Bites in the Classroom: Incidence, Treatment, and Complications
ERIC Educational Resources Information Center
Conlon, Helen Acree
2007-01-01
It has been estimated that at least one half of the population will experience some type of bite in their lifetime. Human bites are the third leading cause of all bites seen in hospital emergency departments after dog and cat bites. Human bites can be the source of exposure to body fluids, transmission of communicable diseases, infections ranging…
Global earthquake fatalities and population
Holzer, Thomas L.; Savage, James C.
2013-01-01
Modern global earthquake fatalities can be separated into two components: (1) fatalities from an approximately constant annual background rate that is independent of world population growth and (2) fatalities caused by earthquakes with large human death tolls, the frequency of which is dependent on world population. Earthquakes with death tolls greater than 100,000 (and 50,000) have increased with world population and obey a nonstationary Poisson distribution with rate proportional to population. We predict that the number of earthquakes with death tolls greater than 100,000 (50,000) will increase in the 21st century to 8.7±3.3 (20.5±4.3) from 4 (7) observed in the 20th century if world population reaches 10.1 billion in 2100. Combining fatalities caused by the background rate with fatalities caused by catastrophic earthquakes (>100,000 fatalities) indicates global fatalities in the 21st century will be 2.57±0.64 million if the average post-1900 death toll for catastrophic earthquakes (193,000) is assumed.
Milleret, Cyril; Wabakken, Petter; Liberg, Olof; Åkesson, Mikael; Flagstad, Øystein; Andreassen, Harry Peter; Sand, Håkan
2017-01-01
For socially monogamous species, breeder bond dissolution has important consequences for population dynamics, but the extent to which extrinsic or intrinsic population factors causes pair dissolution remain poorly understood, especially among carnivores. Using an extensive life-history data set, a survival analysis and competing risks framework, we examined the fate of 153 different wolf (Canis lupus) pairs in the recolonizing Scandinavian wolf population, during 14 winters of snow tracking and DNA monitoring. Wolf pair dissolution was generally linked to a mortality event and was strongly affected by extrinsic (i.e. anthropogenic) causes. No divorce was observed, and among the pair dissolution where causes have been identified, death of one or both wolves was always involved. Median time from pair formation to pair dissolution was three consecutive winters (i.e. approximately 2 years). Pair dissolution was mostly human-related, primarily caused by legal control actions (36·7%), verified poaching (9·2%) and traffic-related causes (2·1%). Intrinsic factors, such as disease and age, accounted for only 7·7% of pair dissolutions. The remaining 44·3% of dissolution events were from unknown causes, but we argue that a large portion could be explained by an additional source of human-caused mortality, cryptic poaching. Extrinsic population factors, such as variables describing the geographical location of the pair, had a stronger effect on risk of pair dissolution compared to anthropogenic landscape characteristics. Population intrinsic factors, such as the inbreeding coefficient of the male pair member, had a negative effect on pair bond duration. The mechanism behind this result remains unknown, but might be explained by lower survival of inbred males or more complex inbreeding effects mediated by behaviour. Our study provides quantitative estimates of breeder bond duration in a social carnivore and highlights the effect of extrinsic (i.e. anthropogenic) and intrinsic factors (i.e. inbreeding) involved in wolf pair bond duration. Unlike the effects of intrinsic and extrinsic factors that are commonly reported on individual survival or population growth, here we provide quantitative estimates of their potential effect on the social unit of the population, the wolf pair. © 2016 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.
Climate variability, human wildlife conflict and population dynamics of lions Panthera leo.
Trinkel, Martina
2013-04-01
Large carnivores are threatened by habitat loss, declining prey populations and direct persecution. Pride dynamics of eight lion prides in the centre of the Etosha National Park, Namibia are described during a 16-year study. Since the beginning of the 1980s, the number of adult and subadult lions declined continuously to two third of its initial population size, and reached a new equilibrium in the 1990s. Pride sizes decreased from 6.3 adult females in 1989 to 2.8 lionesses in 1997. While the number of adult females declined continuously, the number of adult males, subadult females and subadult males remained constant over the years. A severe drought period, lasting for more than 20 years, led to declining prey populations inside the lions' territory. Besides declining prey populations, conflict with humans at the border of Etosha puts substantial pressure onto the lion population: 82% of all known lion mortalities were caused by humans, and most of these consisted of adult females (28%) and subadult males (29%). I postulate that the considerable decline in the lion population is a response to declining prey populations, and although the human predator conflict is severe, it does not seem to limit the size of Etosha's lion population.
Climate variability, human wildlife conflict and population dynamics of lions Panthera leo
NASA Astrophysics Data System (ADS)
Trinkel, Martina
2013-04-01
Large carnivores are threatened by habitat loss, declining prey populations and direct persecution. Pride dynamics of eight lion prides in the centre of the Etosha National Park, Namibia are described during a 16-year study. Since the beginning of the 1980s, the number of adult and subadult lions declined continuously to two third of its initial population size, and reached a new equilibrium in the 1990s. Pride sizes decreased from 6.3 adult females in 1989 to 2.8 lionesses in 1997. While the number of adult females declined continuously, the number of adult males, subadult females and subadult males remained constant over the years. A severe drought period, lasting for more than 20 years, led to declining prey populations inside the lions' territory. Besides declining prey populations, conflict with humans at the border of Etosha puts substantial pressure onto the lion population: 82 % of all known lion mortalities were caused by humans, and most of these consisted of adult females (28 %) and subadult males (29 %). I postulate that the considerable decline in the lion population is a response to declining prey populations, and although the human predator conflict is severe, it does not seem to limit the size of Etosha's lion population.
The impact of mycotoxicoses on human history.
Peraica, Maja; Rašić, Dubravka
2012-12-01
Mycotoxicoses are acute or chronic diseases of humans and animals caused by mycotoxins, toxic compounds produced by moulds. Of about 400 known mycotoxins only a small number are known to cause mycotoxicoses in humans. Organs that are most targeted are those in which mycotoxins are metabolised, that is, the liver and kidneys, but the lesions may affect the neurological, respiratory, digestive, haematological, endocrine, and immune systems as well. The epidemics of mycotoxicoses are often connected with times of famine, when population consumes food that would not be consumed in normal circumstances. Mycotoxicoses have influenced human history, causing demographic changes, migrations, or even influencing the outcomes of wars. Fortunately, epidemics affecting so many persons and with so many fatalities belong to the past. Today they only appear in small communities such as schools and factory canteens. This paper presents epidemics and pandemics of mycotoxicoses that influenced human history.
Wu, Zhiwei; He, Hong S; Yang, Jian; Liu, Zhihua; Liang, Yu
2014-09-15
Fire significantly affects species composition, structure, and ecosystem processes in boreal forests. Our study objective was to identify the relative effects of climate, vegetation, topography, and human activity on fire occurrence in Chinese boreal forest landscapes. We used historical fire ignition for 1966-2005 and the statistical method of Kernel Density Estimation to derive fire-occurrence density (number of fires/km(2)). The Random Forest models were used to quantify the relative effects of climate, vegetation, topography, and human activity on fire-occurrence density. Our results showed that fire-occurrence density tended to be spatially clustered. Human-caused fire occurrence was highly clustered at the southern part of the region, where human population density is high (comprising about 75% of the area's population). In the north-central areas where elevations are the highest in the region and less densely populated, lightning-caused fires were clustered. Climate factors (e.g., fine fuel and duff moisture content) were important at both regional and landscape scales. Human activity factors (e.g., distance to nearest settlement and road) were secondary to climate as the primary fire occurrence factors. Predictions of fire regimes often assume a strong linkage between climate and fire but usually with less emphasis placed on the effects of local factors such as human activity. We therefore suggest that accurate forecasting of fire regime should include human influences such as those measured by forest proximity to roads and human settlements. Copyright © 2014 Elsevier B.V. All rights reserved.
A Culture Of Health And Human Rights.
Mariner, Wendy K; Annas, George J
2016-11-01
A culture of health can be seen as a social norm that values health as the nation's priority or as an appeal to improve the social determinants of health. Better population health will require changing social and economic policies. Effective changes are unlikely unless health advocates can leverage a framework broader than health to mobilize political action in collaboration with non-health sector advocates. We suggest that human rights-the dominant international source of norms for government responsibilities-provides this broader framework. Human rights, as expressed in the Universal Declaration of Human Rights and enforceable treaties, require governments to assure their populations nondiscriminatory access to food, water, education, work, social security, and a standard of living adequate for health and well-being. The policies needed to realize human rights also improve population health, well-being, and equity. Aspirations for human rights are strong enough to endure beyond inevitable setbacks to specific causes. Project HOPE—The People-to-People Health Foundation, Inc.
Cyanobacteria: State Monitoring Programs, Beach Closures, and Potential Human Health Risks
New England is rich in freshwater lakes and ponds, many of which are subject to cyanobacteria (blue-green algae) blooms that can limit recreational use and cause health problems. This study was conducted to better understand the health risks to human and animal populations that a...
Digital forestry in the wildland urban interface
Michael C. Wimberly; Yangjian Zhang; John A. Stanturf
2006-01-01
Growing human populations have led to the expansion of the Wildland-Urban interface (WUI) across the southeastern United States. The juxtaposition of buildings, infrastructure, and forests in the WUI creates challenges for natural resource managers. The presence of flammable vegetation, high rates of human-caused ignitions and high building densities combine to...
Digital forestry in the wildland-urban interface
Michael C. Wimberly; Yangjian Zhang; John A. Stanturf
2006-01-01
Growing human populations have led to the expansion of the Wildland-Urban Interface (WUI) across the southeastern United States. The juxtaposition of buildings, infrastructure. and forests in the WUI creates challenges for natural resource managers. The presence of flammable vegetation. high rates of human-caused ignitions and high building densities combine to...
Michelacci, Valeria; Bondì, Roslen; Gigliucci, Federica; Franz, Eelco; Badouei, Mahdi Askari; Schlager, Sabine; Minelli, Fabio; Tozzoli, Rosangela; Caprioli, Alfredo; Morabito, Stefano
2016-01-01
Verotoxigenic Escherichia coli infections in humans cause disease ranging from uncomplicated intestinal illnesses to bloody diarrhea and systemic sequelae, such as hemolytic uremic syndrome (HUS). Previous research indicated that pigeons may be a reservoir for a population of verotoxigenic E. coli producing the VT2f variant. We used whole-genome sequencing to characterize a set of VT2f-producing E. coli strains from human patients with diarrhea or HUS and from healthy pigeons. We describe a phage conveying the vtx2f genes and provide evidence that the strains causing milder diarrheal disease may be transmitted to humans from pigeons. The strains causing HUS could derive from VT2f phage acquisition by E. coli strains with a virulence genes asset resembling that of typical HUS-associated verotoxigenic E. coli. PMID:27584691
Population growth, human development, and deforestation in biodiversity hotspots.
Jha, S; Bawa, K S
2006-06-01
Human population and development activities affect the rate of deforestation in biodiversity hotspots. We quantified the effect of human population growth and development on rates of deforestation and analyzed the relationship between these causal factors in the 1980s and 1990s. We compared the averages of population growth, human development index (HDI, which measures income, health, and education), and deforestation rate and computed correlations among these variables for countries that contain biodiversity hotspots. When population growth was high and HDI was low there was a high rate of deforestation, but when HDI was high, rate of deforestation was low, despite high population growth. The correlation among variables was significant for the 1990s but not for the 1980s. The relationship between population growth and HDI had a regional pattern that reflected the historical process of development. Based on the changes in HDI and deforestation rate over time, we identified two drivers of deforestation: policy choice and human-development constraints. Policy choices that disregard conservation may cause the loss of forests even in countries that are relatively developed. Lack of development in other countries, on the other hand, may increase the pressure on forests to meet the basic needs of the human population. Deforestation resulting from policy choices may be easier to fix than deforestation arising from human development constraints. To prevent deforestation in the countries that have such constraints, transfer of material and intellectual resources from developed countries may be needed. Popular interest in sustainable development in developed countries can facilitate the transfer of these resources.
Bansal, M; Kaur, S; Deka, D; Singh, R; Gill, J P S
2017-12-01
Hepatitis E virus (HEV) has two discrete epidemiological patterns: waterborne epidemics in developing countries only, caused by HEV genotype I, and sporadic zoonotic outbreaks in developing and developed countries caused by genotypes III and IV. This study was designed to investigate seroprevalence, molecular detection and the characterization of HEV by nested RT-PCR in swine as well as the occupational risk to exposed human population in Punjab state of north-western India. The occupational risk-exposed group comprised of swine farmers (organized - mixed feed feeders and unorganized - swill feeders), slaughterhouse workers, sewage workers and veterinary internes. During the study period, blood and faecal samples were collected from 320 swine and 360 humans with both high and low occupational exposure risks. The overall seroprevalence of swine HEV was 65.00%, with a significantly higher seropositivity in growing pigs (2-8 months of age). The prevalence of HEV RNA in swine faecal samples by nRT-PCR was 8.75% with a significantly higher detection in swill-fed pigs. With humans in the high occupational exposure risk population, significantly higher anti-HEV IgG seropositivity was observed (60.48%) as compared to control population (10.71%). Strong evidence of association between human anti-HEV IgG seropositivity and certain occupational exposure risk groups was observed (p < 0.05). This indicates that unorganized swine farmers, slaughterhouse workers and sewage workers have higher odds of HEV infection in this study region. Percentage of nucleotide similarity between swine and human HEV isolates was less than that found in countries with zoonotic HEV outbreaks. Molecular characterization revealed the circulation of G IV and G I genotypes among swine and human population in Punjab state, respectively. © 2017 Blackwell Verlag GmbH.
The interplay between human population dynamics and flooding in Bangladesh: a spatial analysis
NASA Astrophysics Data System (ADS)
di Baldassarre, G.; Yan, K.; Ferdous, MD. R.; Brandimarte, L.
2014-09-01
In Bangladesh, socio-economic and hydrological processes are both extremely dynamic and inter-related. Human population patterns are often explained as a response, or adaptation strategy, to physical events, e.g. flooding, salt-water intrusion, and erosion. Meanwhile, these physical processes are exacerbated, or mitigated, by diverse human interventions, e.g. river diversion, levees and polders. In this context, this paper describes an attempt to explore the complex interplay between floods and societies in Bangladeshi floodplains. In particular, we performed a spatially-distributed analysis of the interactions between the dynamics of human settlements and flood inundation patterns. To this end, we used flooding simulation results from inundation modelling, LISFLOOD-FP, as well as global datasets of population distribution data, such as the Gridded Population of the World (20 years, from 1990 to 2010) and HYDE datasets (310 years, from 1700 to 2010). The outcomes of this work highlight the behaviour of Bangladeshi floodplains as complex human-water systems and indicate the need to go beyond the traditional narratives based on one-way cause-effects, e.g. climate change leading to migrations.
Controlled fire use in early humans might have triggered the evolutionary emergence of tuberculosis.
Chisholm, Rebecca H; Trauer, James M; Curnoe, Darren; Tanaka, Mark M
2016-08-09
Tuberculosis (TB) is caused by the Mycobacterium tuberculosis complex (MTBC), a wildly successful group of organisms and the leading cause of death resulting from a single bacterial pathogen worldwide. It is generally accepted that MTBC established itself in human populations in Africa and that animal-infecting strains diverged from human strains. However, the precise causal factors of TB emergence remain unknown. Here, we propose that the advent of controlled fire use in early humans created the ideal conditions for the emergence of TB as a transmissible disease. This hypothesis is supported by mathematical modeling together with a synthesis of evidence from epidemiology, evolutionary genetics, and paleoanthropology.
Toward a psychology of human survival: Psychological approaches to contemporary global threats
DOE Office of Scientific and Technical Information (OSTI.GOV)
Walsh, R.
Nuclear weapons, population explosion, resource and food-supply depletion, and environmental deterioration have been posing increasing threats to human survival. Moreover, for the first time in history, all these major global threats are human caused and can, therefore, be traced in large part to psychological origins. After a brief overview of the nature and extent of current threats, this paper suggests criteria for an adequate psychology of human survival. The causes and effects of the threats are examined from various psychological perspectives and the psychological principles underlying effective responses are deduced. The ways in which mental health professionals may contribute tomore » this most crucial task are discussed. 76 references.« less
Rodwell, Timothy C.; Kapasi, Anokhi J.; Moore, Marisa; Milian-Suazo, Feliciano; Harris, Beth; Guerrero, L.P.; Moser, Kathleen; Strathdee, Steffanie A.; Garfein, Richard S.
2010-01-01
Objectives To compare genotypes of Mycobacterium bovis strains from humans in Southern California with genotypes of M. bovis strains in cattle in Mexico and the USA to explore the possible origins of human infections. Methods We conducted a descriptive analysis of M. bovis genotypes from a binational population of humans and cattle using spacer oligonucleotide typing (spoligotyping). Results One hundred six human M. bovis spoligotypes were compared to spoligotypes from 496 Mexican cattle and 219 US cattle. Twelve spoligotype patterns were identified among human cases and 126 spoligotype patterns were detected in cattle. Over 91% (97/106) of the human M. bovis isolates had spoligotypes that were identical to those found in Mexican cattle. Four human cases had spoligotypes that matched both cattle born in Mexico and in the USA. Nine human cases had spoligotypes that did not match cattle born in Mexico or the USA. Conclusions Our data indicate that the population of M. bovis strains causing human TB disease in Southern California is closely related to the M. bovis strain population found in Mexican cattle and supports existing epidemiological evidence that human M. bovis disease in San Diego likely originated from Mexican cattle. PMID:20399697
Dodd, C.K.
1990-01-01
The flattened musk turtle Sternotherus depressus has disappeared from more than half of its former range because of habitat modifications to stream and river channels in the Warrior River Basin, Alabama. Only 6·9% of its probable historic range contains relatively healthy populations, and most populations are fragmented by extensive areas of unsuitable habitat. Turtles in the best remaining habitats continue to be vulnerable to disease and human-related disturbance, collecting and habitat modification. These factors lead to population declines and abnormal population structure. Habitat fragmentation, especially in small populations, increases vulnerability to human-caused catastrophes and demographic accidents, and could lead to eventual extinction. The threats facing fragmented populations of this turtle probably parallel those affecting many other stream-dwelling species throughout the southeastern United States.
Rapid climate change did not cause population collapse at the end of the European Bronze Age
Armit, Ian; Swindles, Graeme T.; Becker, Katharina; Plunkett, Gill; Blaauw, Maarten
2014-01-01
The impact of rapid climate change on contemporary human populations is of global concern. To contextualize our understanding of human responses to rapid climate change it is necessary to examine the archeological record during past climate transitions. One episode of abrupt climate change has been correlated with societal collapse at the end of the northwestern European Bronze Age. We apply new methods to interrogate archeological and paleoclimate data for this transition in Ireland at a higher level of precision than has previously been possible. We analyze archeological 14C dates to demonstrate dramatic population collapse and present high-precision proxy climate data, analyzed through Bayesian methods, to provide evidence for a rapid climatic transition at ca. 750 calibrated years B.C. Our results demonstrate that this climatic downturn did not initiate population collapse and highlight the nondeterministic nature of human responses to past climate change. PMID:25404290
Rapid climate change did not cause population collapse at the end of the European Bronze Age.
Armit, Ian; Swindles, Graeme T; Becker, Katharina; Plunkett, Gill; Blaauw, Maarten
2014-12-02
The impact of rapid climate change on contemporary human populations is of global concern. To contextualize our understanding of human responses to rapid climate change it is necessary to examine the archeological record during past climate transitions. One episode of abrupt climate change has been correlated with societal collapse at the end of the northwestern European Bronze Age. We apply new methods to interrogate archeological and paleoclimate data for this transition in Ireland at a higher level of precision than has previously been possible. We analyze archeological (14)C dates to demonstrate dramatic population collapse and present high-precision proxy climate data, analyzed through Bayesian methods, to provide evidence for a rapid climatic transition at ca. 750 calibrated years B.C. Our results demonstrate that this climatic downturn did not initiate population collapse and highlight the nondeterministic nature of human responses to past climate change.
The Asian Taenia and the possibility of cysticercosis.
Galán-Puchades, M T; Fuentes, M V
2000-03-01
In certain Asian countries, a third form of human Taenia, also known as the Asian Taenia, has been discovered. This Asian Taenia seems to be an intermediate between Taenia solium and T. saginata since in morphological terms it is similar to T. saginata, yet biologically, as it uses the same intermediate host (pigs), it is more akin to T. solium. Taenia solium causes human cysticercosis, while T. saginata does not. It is not known whether the Asian taeniid is able to develop to the larval stage in humans or not. The arguments proposed by those authors who consider it unlikely that the Asian Taenia causes human cysticercosis are: (a) its molecular similarities with T. saginata; (b) the absence of cases of human cysticercosis in populations where the Asian adult is highly prevalent; and (c) the unsupporting results derived from an experimental infestation study. These three arguments are debated, although bearing in mind that at present there is still no clear scientific data to support that human cysticercosis can be caused by the Asian Taenia.
Viral infections associated with oral cancers and diseases in the context of HIV: Workshop 3B
Speicher, David J; Ramirez-Amador, Velia; Dittmer, Dirk P; Webster-Cyriaque, Jennifer; Goodman, Marc T; Moscicki, Anna-Barbara
2017-01-01
Human herpesviruses (HHVs) and Human papillomaviruses (HPV) are common in the general population and, in immunocompetent people, are mostly carried asymptomatically. However, once an individual becomes immunocompromised by age, illness, or HIV infection these dormant viruses can manifest themselves and produce disease. In HIV-positive patients there is an increased risk of disease caused by HHVs and HPV infections and cancers caused by the oncoviruses EBV, HHV-8, and HPV. This workshop examined four questions regarding the viruses associated with oral cancers disease in the HIV-positive and -negative populations, the immune response, and biomarkers useful for accurate diagnostics of these infections and their sequalae. Each presenter identified a number of key areas where further research is required. PMID:27109286
[An overview on swine influenza viruses].
Yang, Shuai; Zhu, Wen-Fei; Shu, Yue-Long
2013-05-01
Swine influenza viruses (SIVs) are respiratory pathogens of pigs. They cause both economic bur den in livestock-dependent industries and serious global public health concerns in humans. Because of their dual susceptibility to human and avian influenza viruses, pigs are recognized as intermediate hosts for genetic reassortment and interspecies transmission. Subtypes H1N1, H1N2, and H3N2 circulate in swine populations around the world, with varied origin and genetic characteristics among different continents and regions. In this review, the role of pigs in evolution of influenza A viruses, the genetic evolution of SIVs and interspecies transmission of SIVs are described. Considering the possibility that pigs might produce novel influenza viruses causing more outbreaks and pandemics, routine epidemiological surveillance of influenza viruses in pig populations is highly recommended.
California condors: status of the recovery effort
Jared Verner
1978-01-01
Disturbance and high mortality related to human activity have apparently caused the decline of the condor population to about 50 birds. Failure to reproduce successfully is now the central problem; inadequate food supply near nest sites, lack of nest sites in new concentration areas, and pesticide accumulation in condor tissues are possible causes. Low reproductive...
Anthropogenic transformation of the terrestrial biosphere.
Ellis, Erle C
2011-03-13
Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.
Climate change, human health, and epidemiological transition
Barrett, Bruce; Charles, Joel W.; Temte, Jonathan L.
2015-01-01
The health of populations depends on the availability of clean air, water, food, and sanitation, exposure to pathogens, toxins and environmental hazards, and numerous genetic, behavioral and social factors. For many thousands of years, human life expectancy was low, and population growth was slow. The development of technology-based civilizations facilitated what Abdel Omran called “epidemiological transition,” with increasing life expectancy and rapid population growth. To a large extent, the spectacular growth of human populations during the past two centuries was made possible by the energy extracted from fossil fuels. We have now learned, however, that greenhouse gases from fossil fuel combustion are warming the planet's surface, causing changes in oceanic and atmospheric systems, and disrupting weather and hydrological patterns. Climate change poses unprecedented threats to human health by impacts on food and water security, heat waves and droughts, violent storms, infectious disease, and rising sea levels. Whether or not humanity can reduce greenhouse gas emissions quickly enough to slow climate change to a rate that will allow societies to successfully adapt is not yet known. This essay reviews the current state of relevant knowledge, and points in a few directions that those interested in human health may wish to consider. PMID:25434735
Mecenero, Silvia; Altwegg, Res; Colville, Jonathan F.; Beale, Colin M.
2015-01-01
Wildlife and humans tend to prefer the same productive environments, yet high human densities often lead to reduced biodiversity. Species richness is often positively correlated with human population density at broad scales, but this correlation could also be caused by unequal sampling effort leading to higher species tallies in areas of dense human activity. We examined the relationships between butterfly species richness and human population density at five spatial resolutions ranging from 2' to 60' across South Africa. We used atlas-type data and spatial interpolation techniques aimed at reducing the effect of unequal spatial sampling. Our results confirm the general positive correlation between total species richness and human population density. Contrary to our expectations, the strength of this positive correlation did not weaken at finer spatial resolutions. The patterns observed using total species richness were driven mostly by common species. The richness of threatened and restricted range species was not correlated to human population density. None of the correlations we examined were particularly strong, with much unexplained variance remaining, suggesting that the overlap between butterflies and humans is not strong compared to other factors not accounted for in our analyses. Special consideration needs to be made regarding conservation goals and variables used when investigating the overlap between species and humans for biodiversity conservation. PMID:25915899
Mecenero, Silvia; Altwegg, Res; Colville, Jonathan F; Beale, Colin M
2015-01-01
Wildlife and humans tend to prefer the same productive environments, yet high human densities often lead to reduced biodiversity. Species richness is often positively correlated with human population density at broad scales, but this correlation could also be caused by unequal sampling effort leading to higher species tallies in areas of dense human activity. We examined the relationships between butterfly species richness and human population density at five spatial resolutions ranging from 2' to 60' across South Africa. We used atlas-type data and spatial interpolation techniques aimed at reducing the effect of unequal spatial sampling. Our results confirm the general positive correlation between total species richness and human population density. Contrary to our expectations, the strength of this positive correlation did not weaken at finer spatial resolutions. The patterns observed using total species richness were driven mostly by common species. The richness of threatened and restricted range species was not correlated to human population density. None of the correlations we examined were particularly strong, with much unexplained variance remaining, suggesting that the overlap between butterflies and humans is not strong compared to other factors not accounted for in our analyses. Special consideration needs to be made regarding conservation goals and variables used when investigating the overlap between species and humans for biodiversity conservation.
Paudyal, Narayan; Pan, Hang; Li, Xiaoliang; Fang, Weihuan; Yue, Min
2018-06-21
Salmonella enterica subspecies enterica serotype Enteritidis (S. Enteritidis) is one of the leading causes for human salmonellosis all over the world. We analyzed the surveillance data of 18 years on antimicrobial resistance profiling of S. Enteritidis collected and isolated by the National Antimicrobial Resistance Monitoring System (NARMS) from humans, chicken, and chicken breasts. Statistical tool based on the unique individual antibiotic minimum inhibitory concentration (MIC) profiling was used to compare antimicrobial resistance in the isolates. A machine-learning algorithm, Random Forest matrix, segregated a collection of 6819 S. Enteritidis into multiple populations. The MIC value of 13 common antibiotics to individual isolate when taken as the best classifier, resulted in two distinct groups represented herein as Population-I and Population-II. Population-I, which spread within a small tight cluster, comprised all the chicken and chicken breasts' isolates as well as about 13.4% of the human isolates, whereas the Population-II consisted of the human isolates only, with a larger spread over wider area away from the Population-I (p < 0.001). Few overlapping, yet diverse clusters between humans and chicken as well as higher level of resistance of chicken breast isolate toward third-generation cephalosporins and tetracyclines compared to those from human isolates, highlight differences in their population structure. These findings indicate a complex driver for enriching antibiotic-resistant Salmonella in the food-chain other than those of chicken origin. This warrants for other strategies in addition to the judicious/restricted use of antibiotics to mitigate the threat of antimicrobial resistance.
Human obesity associated with an intronic SNP in the brain-derived neurotrophic factor locus
USDA-ARS?s Scientific Manuscript database
Brain-derived neurotrophic factor (BDNF) plays a key role in energy balance. In population studies, SNPs of the BDNF locus have been linked to obesity, but the mechanism by which these variants cause weight gain is unknown. Here, we examined human hypothalamic BDNF expression in association with 44 ...
ERIC Educational Resources Information Center
Hughes, Courtney
2013-01-01
Namibia's cheetah population has predominantly been threatened by human conflict related to livestock farming and habitat loss. Cheetahs have been indiscriminately persecuted as a mortal threat to livestock, as well as suffered from human-caused land use change. The Cheetah Conservation Fund (CCF) in Otjiwarongo, Namibia conducts cheetah research…
Richard Guyette; Mavis Dey; Dan Dey
1999-01-01
Missouri's natural communities have been shaped by humans and wildland fires for thousands of years. In many ways, the history of fire in Missouri also is a history of human population, culture and migration. Fires caused by natural ignition, like lightning, are rare. Despite as many as 50 to 70 thunderstorm days per year, Conservation Department studies indicate...
Biodiversity and the exotic species threat
Peter S. White
1998-01-01
Exotic species invasions, called by one conservation biologist the "least reversible" of all human impacts, cause harm to economies (e.g., fisheries, wildlife populations, tourism), the environment (e.g., in the form of broadcast of pesticides and herbicides), human health and wellbeing (e.g., allergic responses and the increase in fire severity in some...
Dissection of Host Susceptibility to Bacterial Infections and Its Toxins.
Nashef, Aysar; Agbaria, Mahmoud; Shusterman, Ariel; Lorè, Nicola Ivan; Bragonzi, Alessandra; Wiess, Ervin; Houri-Haddad, Yael; Iraqi, Fuad A
2017-01-01
Infection is one of the leading causes of human mortality and morbidity. Exposure to microbial agents is obviously required. However, also non-microbial environmental and host factors play a key role in the onset, development and outcome of infectious disease, resulting in large of clinical variability between individuals in a population infected with the same microbe. Controlled and standardized investigations of the genetics of susceptibility to infectious disease are almost impossible to perform in humans whereas mouse models allow application of powerful genomic techniques to identify and validate causative genes underlying human diseases with complex etiologies. Most of current animal models used in complex traits diseases genetic mapping have limited genetic diversity. This limitation impedes the ability to create incorporated network using genetic interactions, epigenetics, environmental factors, microbiota, and other phenotypes. A novel mouse genetic reference population for high-resolution mapping and subsequently identifying genes underlying the QTL, namely the Collaborative Cross (CC) mouse genetic reference population (GRP) was recently developed. In this chapter, we discuss a variety of approaches using CC mice for mapping genes underlying quantitative trait loci (QTL) to dissect the host response to polygenic traits, including infectious disease caused by bacterial agents and its toxins.
Prasetyo, R H
2016-03-01
The purpose of this study was to investigate the prevalence of house rat zoonotic intestinal parasites from Surabaya District, East Java, Indonesia that have the potential to cause opportunistic infection in humans. House rat fecal samples were collected from an area of Surabaya District with a dense rat population during May 2015. Intestinal parasites were detected microscopically using direct smear of feces stained with Lugol's iodine and modified Ziehl-Neelsen stains. The fecal samples were also cultured for Strongyloides stercoralis. Ninety-eight house rat fecal samples were examined. The potential opportunistic infection parasite densities found in those samples were Strongyloides stercoralis in 53%, Hymenolepis nana in 42%, Cryptosporidium spp in 33%, and Blastocystis spp in 6%. This is the first report of this kind in Surabaya District. Measures need to be taken to control the house rat population in the study area to reduce the risk of the public health problem. Keywords: zoonotic intestinal parasites, opportunistic infection, house rat, densely populated area, Indonesia
Timing and causes of mid-Holocene mammoth extinction on St. Paul Island, Alaska
Graham, Russell W.; Belmecheri, Soumaya; Choy, Kyungcheol; Culleton, Brendan J.; Davies, Lauren J.; Hritz, Carrie; Kapp, Joshua D.; Newsom, Lee A.; Rawcliffe, Ruth; Saulnier-Talbot, Émilie; Wang, Yue; Williams, John W.; Wooller, Matthew J.
2016-01-01
Relict woolly mammoth (Mammuthus primigenius) populations survived on several small Beringian islands for thousands of years after mainland populations went extinct. Here we present multiproxy paleoenvironmental records to investigate the timing, causes, and consequences of mammoth disappearance from St. Paul Island, Alaska. Five independent indicators of extinction show that mammoths survived on St. Paul until 5,600 ± 100 y ago. Vegetation composition remained stable during the extinction window, and there is no evidence of human presence on the island before 1787 CE, suggesting that these factors were not extinction drivers. Instead, the extinction coincided with declining freshwater resources and drier climates between 7,850 and 5,600 y ago, as inferred from sedimentary magnetic susceptibility, oxygen isotopes, and diatom and cladoceran assemblages in a sediment core from a freshwater lake on the island, and stable nitrogen isotopes from mammoth remains. Contrary to other extinction models for the St. Paul mammoth population, this evidence indicates that this mammoth population died out because of the synergistic effects of shrinking island area and freshwater scarcity caused by rising sea levels and regional climate change. Degradation of water quality by intensified mammoth activity around the lake likely exacerbated the situation. The St. Paul mammoth demise is now one of the best-dated prehistoric extinctions, highlighting freshwater limitation as an overlooked extinction driver and underscoring the vulnerability of small island populations to environmental change, even in the absence of human influence. PMID:27482085
Productivity, mortality, and population trends of wolves in northeastern Minnesota
Mech, L.D.
1977-01-01
Population parameters, mortality causes, and mechanisms of a population decline were studied in wolves (Canis lupus lycaon) from 1968 to 1976 in the Superior National Forest. The main method was aerial radio-tracking of 129 wolves and their packmates. Due to a decline in white-tailed deer (Odocoileus virginianus), the wolf population decreased during most of the study. Average annual productivity varied from 1.5 to 3.3 pups per litter, and annual mortality rates from 7 to 65 percent. Malnutrition and intraspecific strife accounted equally for 58 percent of the mortality; human causes accounted for the remainder. As wolf numbers began to decline, pup starvation became apparent, followed by lower pup production, and then by increased intraspecific strife. At higher densities, adult pack wolves were the most secure members of the population, but as the population declined, they became the least secure because of intraspecific strife.
Lima, Mauricio; Christie, Duncan A; Santoro, M Calogero; Latorre, Claudio
2016-01-01
Socio-economic and environmental changes are well known causes of demographic collapse of agrarian cultures. The collapse of human societies is a complex phenomenon where historical and cultural dimensions play a key role, and they may interact with the environmental context. However, the importance of the interaction between socio-economic and climatic factors in explaining possible breakdowns in Native American societies has been poorly explored. The aim of this study is to test the role of socio-economic causes and rainfall variability in the collapse suffered by the Aymara people of the semiarid Andean region of Tarapacá during the period 1820-1970. Our motivation is to demonstrate that simple population dynamic models can be helpful in understanding the causes and relative importance of population changes in Andean agro-pastoral societies in responses to socio-environmental variability. Simple logistic models that combine the effects of external socio-economic causes and past rainfall variability (inferred from Gross Domestic Product [GDP] and tree-rings, respectively) were quite accurate in predicting the sustained population decline of the Aymara people. Our results suggest that the depopulation in the semiarid Tarapacá province was caused by the interaction among external socio-economic pressures given by the economic growth of the lowlands and demands for labor coupled with a persistent decline in rainfall. This study constitutes an example of how applied ecological knowledge, in particular the application of the logistic equation and theories pertaining to nonlinear population dynamics and exogenous perturbations, can be used to better understand major demographic changes in human societies.
Lima, Mauricio; Christie, Duncan A.; Santoro, M. Calogero; Latorre, Claudio
2016-01-01
Socio-economic and environmental changes are well known causes of demographic collapse of agrarian cultures. The collapse of human societies is a complex phenomenon where historical and cultural dimensions play a key role, and they may interact with the environmental context. However, the importance of the interaction between socio-economic and climatic factors in explaining possible breakdowns in Native American societies has been poorly explored. The aim of this study is to test the role of socio-economic causes and rainfall variability in the collapse suffered by the Aymara people of the semiarid Andean region of Tarapacá during the period 1820–1970. Our motivation is to demonstrate that simple population dynamic models can be helpful in understanding the causes and relative importance of population changes in Andean agro-pastoral societies in responses to socio-environmental variability. Simple logistic models that combine the effects of external socio-economic causes and past rainfall variability (inferred from Gross Domestic Product [GDP] and tree-rings, respectively) were quite accurate in predicting the sustained population decline of the Aymara people. Our results suggest that the depopulation in the semiarid Tarapacá province was caused by the interaction among external socio-economic pressures given by the economic growth of the lowlands and demands for labor coupled with a persistent decline in rainfall. This study constitutes an example of how applied ecological knowledge, in particular the application of the logistic equation and theories pertaining to nonlinear population dynamics and exogenous perturbations, can be used to better understand major demographic changes in human societies. PMID:27560499
Brucellosis in low-income and middle-income countries
Rubach, Matthew P.; Halliday, Jo E.B.; Cleaveland, Sarah; Crump, John A.
2014-01-01
Purpose of review Human brucellosis is a neglected, underrecognized infection of widespread geographic distribution. It causes acute febrile illness and a potentially debilitating chronic infection in humans, and livestock infection has substantial socioeconomic impact. This review describes new information regarding the epidemiology of brucellosis in the developing world and advances in diagnosis and treatment. Recent findings The highest recorded incidence of human brucellosis occurs in the Middle East and Central Asia. Fever etiology studies demonstrate brucellosis as a cause of undifferentiated febrile illness in the developing world. Brucellosis is a rare cause of fever among returning travelers, but is more common among travelers returning from the Middle East and North Africa. Sensitive and specific rapid diagnostic tests appropriate for resource-limited settings have been validated. Randomized controlled trials demonstrate that optimal treatment for human brucellosis consists of doxycycline and an aminoglycoside. Decreasing the burden of human brucellosis requires control of animal brucellosis, but evidence to inform the design of control programs in the developing world is needed. Summary Brucellosis causes substantial morbidity in human and animal populations. While improvements in diagnostic options for resource-limited settings and stronger evidence for optimal therapy should enhance identification and treatment of human brucellosis, prevention of human disease through control in animals remains paramount. PMID:23963260
USDA-ARS?s Scientific Manuscript database
The legume pod borer, Maruca vitrata, is an endemic insect pest that causes significant yield loss to the cowpea crop in West Africa, and contributes to food shortages and malnutrition in native human populations. The genetic structure of Maruca vitrata was investigated among five sites from Burkin...
Mycobacterium tuberculosis: ecology and evolution of a human bacterium.
Bañuls, Anne-Laure; Sanou, Adama; Anh, Nguyen Thi Van; Godreuil, Sylvain
2015-11-01
Some species of the Mycobacterium tuberculosis complex (MTBC), particularly Mycobacterium tuberculosis, which causes human tuberculosis (TB), are the first cause of death linked to a single pathogen worldwide. In the last decades, evolutionary studies have much improved our knowledge on MTBC history and have highlighted its long co-evolution with humans. Its ability to remain latent in humans, the extraordinary proportion of asymptomatic carriers (one-third of the entire human population), the deadly epidemics and the observed increasing level of resistance to antibiotics are proof of its evolutionary success. Many MTBC molecular signatures show not only that these bacteria are a model of adaptation to humans but also that they have influenced human evolution. Owing to the unbalance between the number of asymptomatic carriers and the number of patients with active TB, some authors suggest that infection by MTBC could have a protective role against active TB disease and also against other pathologies. However, it would be inappropriate to consider these infectious pathogens as commensals or symbionts, given the level of morbidity and mortality caused by TB.
Population dynamics and climate change: what are the links?
Stephenson, Judith; Newman, Karen; Mayhew, Susannah
2010-06-01
Climate change has been described as the biggest global health threat of the 21(st) century. World population is projected to reach 9.1 billion by 2050, with most of this growth in developing countries. While the principal cause of climate change is high consumption in the developed countries, its impact will be greatest on people in the developing world. Climate change and population can be linked through adaptation (reducing vulnerability to the adverse effects of climate change) and, more controversially, through mitigation (reducing the greenhouse gases that cause climate change). The contribution of low-income, high-fertility countries to global carbon emissions has been negligible to date, but is increasing with the economic development that they need to reduce poverty. Rapid population growth endangers human development, provision of basic services and poverty eradication and weakens the capacity of poor communities to adapt to climate change. Significant mass migration is likely to occur in response to climate change and should be regarded as a legitimate response to the effects of climate change. Linking population dynamics with climate change is a sensitive issue, but family planning programmes that respect and protect human rights can bring a remarkable range of benefits. Population dynamics have not been integrated systematically into climate change science. The contribution of population growth, migration, urbanization, ageing and household composition to mitigation and adaptation programmes needs urgent investigation.
Comparative Population Genomics Analysis of the Mammalian Fungal Pathogen Pneumocystis
Ma, Liang; Wei Huang, Da; Khil, Pavel P.; Dekker, John P.; Kutty, Geetha; Bishop, Lisa; Liu, Yueqin; Deng, Xilong; Pagni, Marco; Hirsch, Vanessa; Lempicki, Richard A.
2018-01-01
ABSTRACT Pneumocystis species are opportunistic mammalian pathogens that cause severe pneumonia in immunocompromised individuals. These fungi are highly host specific and uncultivable in vitro. Human Pneumocystis infections present major challenges because of a limited therapeutic arsenal and the rise of drug resistance. To investigate the diversity and demographic history of natural populations of Pneumocystis infecting humans, rats, and mice, we performed whole-genome and large-scale multilocus sequencing of infected tissues collected in various geographic locations. Here, we detected reduced levels of recombination and variations in historical demography, which shape the global population structures. We report estimates of evolutionary rates, levels of genetic diversity, and population sizes. Molecular clock estimates indicate that Pneumocystis species diverged before their hosts, while the asynchronous timing of population declines suggests host shifts. Our results have uncovered complex patterns of genetic variation influenced by multiple factors that shaped the adaptation of Pneumocystis populations during their spread across mammals. PMID:29739910
Grinberg, Alex; Biggs, Patrick J; Zhang, Ji; Ritchie, Stephen; Oneroa, Zachary; O'Neill, Charlotte; Karkaba, Ali; Velathanthiri, Niluka S; Coombs, Geoffrey W
2017-10-01
Staphylococcus aureus skin and soft tissue infection (Sa-SSTI) places a significant burden on healthcare systems. New Zealand has a high incidence of Sa-SSTI, and here most morbidity is caused by a polyclonal methicillin-susceptible (MSSA) bacterial population. However, MSSA also colonise asymptomatically the cornified epithelia of approximately 20% of the population, and their divide between commensalism and pathogenicity is poorly understood. We aimed to see whether MSSA are genetically differentiated across colonisation and SSTI; and given the close interactions between people and pets, whether strains isolated from pets differ from human strains. We compared the genomes of contemporaneous colonisation and clinical MSSA isolates obtained in New Zealand from humans and pets. Core and accessory genome comparisons revealed a homogeneous bacterial population across colonisation, disease, humans, and pets. The rate of MSSA colonisation in dogs was comparatively low (5.4%). In New Zealand, most Sa-SSTI morbidity is caused by a random sample of the colonising MSSA population, consistent with the opportunistic infection model rather than the paradigm distinguishing strains according to their pathogenicity. Thus, studies of the factors determining colonisation and immune-escape may be more beneficial than comparative virulence studies. Contact with house-hold pets may pose low zoonotic risk. Copyright © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.
Modeling the Impacts of Hydromodification (Conference paper)
Hydromodification is caused by anthropogenic activities driven by human population growth and resource consumption that alter watershed hydrologic responses. These activities include urbanization, channel modification, flow regulation by water impoundments, water withdrawal, and...
Characterization of Greater Middle Eastern genetic variation for enhanced disease gene discovery.
Scott, Eric M; Halees, Anason; Itan, Yuval; Spencer, Emily G; He, Yupeng; Azab, Mostafa Abdellateef; Gabriel, Stacey B; Belkadi, Aziz; Boisson, Bertrand; Abel, Laurent; Clark, Andrew G; Alkuraya, Fowzan S; Casanova, Jean-Laurent; Gleeson, Joseph G
2016-09-01
The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia, has resulted in an elevated burden of recessive disease. Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized 'genetic purging'. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics.
Assessing impacts of oil-shale development on the Piceance Basin mule deer herd
DOE Office of Scientific and Technical Information (OSTI.GOV)
White, G.C.; Garrott, R.A.
Development of energy resources on big game ranges generally negatively impacts these important wildlife resources. Although habitat disturbance is generally important, this impact is overshadowed by the negative impacts due to an increasing human population in the area. Increased human activities particularly stress animals during winter periods when inadequate nutrition levels may have already severely impacted the population. Increased road traffic and poaching causes additional deaths, which a decline in survival rates expected, or at least changes in the cause of mortality. This paper describes the experimental design to monitor and mitigate the impact of oil shale development in northwesternmore » Colorado on the Piceance Basin mule deer herd. Biotelemetry techniques are used to measure changes through time in movements, habitat utilization, and survival rates between control and treatment areas. 2 figures.« less
Stochastic dynamics of dengue epidemics.
de Souza, David R; Tomé, Tânia; Pinho, Suani T R; Barreto, Florisneide R; de Oliveira, Mário J
2013-01-01
We use a stochastic Markovian dynamics approach to describe the spreading of vector-transmitted diseases, such as dengue, and the threshold of the disease. The coexistence space is composed of two structures representing the human and mosquito populations. The human population follows a susceptible-infected-recovered (SIR) type dynamics and the mosquito population follows a susceptible-infected-susceptible (SIS) type dynamics. The human infection is caused by infected mosquitoes and vice versa, so that the SIS and SIR dynamics are interconnected. We develop a truncation scheme to solve the evolution equations from which we get the threshold of the disease and the reproductive ratio. The threshold of the disease is also obtained by performing numerical simulations. We found that for certain values of the infection rates the spreading of the disease is impossible, for any death rate of infected mosquitoes.
Rodwell, Timothy C; Kapasi, Anokhi J; Moore, Marisa; Milian-Suazo, Feliciano; Harris, Beth; Guerrero, L P; Moser, Kathleen; Strathdee, Steffanie A; Garfein, Richard S
2010-09-01
To compare genotypes of Mycobacterium bovis strains from humans in Southern California with genotypes of M. bovis strains in cattle in Mexico and the USA to explore the possible origins of human infections. We conducted a descriptive analysis of M. bovis genotypes from a binational population of humans and cattle using spacer oligonucleotide typing (spoligotyping). One hundred six human M. bovis spoligotypes were compared to spoligotypes from 496 Mexican cattle and 219 US cattle. Twelve spoligotype patterns were identified among human cases and 126 spoligotype patterns were detected in cattle. Over 91% (97/106) of the human M. bovis isolates had spoligotypes that were identical to those found in Mexican cattle. Four human cases had spoligotypes that matched both cattle born in Mexico and in the USA. Nine human cases had spoligotypes that did not match cattle born in Mexico or the USA. Our data indicate that the population of M. bovis strains causing human TB disease in Southern California is closely related to the M. bovis strain population found in Mexican cattle and supports existing epidemiological evidence that human M. bovis disease in San Diego likely originated from Mexican cattle. Copyright © 2010 International Society for Infectious Diseases. All rights reserved.
Queen, Rachel A.; Steyn, Jannetta S.; Lord, Phillip
2017-01-01
Mitochondrial DNA (mtDNA) mutations are well recognized as an important cause of inherited disease. Diseases caused by mtDNA mutations exhibit a high degree of clinical heterogeneity with a complex genotype-phenotype relationship, with many such mutations exhibiting incomplete penetrance. There is evidence that the spectrum of mutations causing mitochondrial disease might differ between different mitochondrial lineages (haplogroups) seen in different global populations. This would point to the importance of sequence context in the expression of mutations. To explore this possibility, we looked for mutations which are known to cause disease in humans, in animals of other species unaffected by mtDNA disease. The mt-tRNA genes are the location of many pathogenic mutations, with the m.3243A>G mutation on the mt-tRNA-Leu(UUR) being the most frequently seen mutation in humans. This study looked for the presence of m.3243A>G in 2784 sequences from 33 species, as well as any of the other mutations reported in association with disease located on mt-tRNA-Leu(UUR). We report a number of disease associated variations found on mt-tRNA-Leu(UUR) in other chordates, as the major population variant, with m.3243A>G being seen in 6 species. In these, we also found a number of mutations which appear compensatory and which could prevent the pathogenicity associated with this change in humans. This work has important implications for the discovery and diagnosis of mtDNA mutations in non-European populations. In addition, it might provide a partial explanation for the conflicting results in the literature that examines the role of mtDNA variants in complex traits. PMID:29161289
Klein, Laura D; Breakey, Alicia A; Scelza, Brooke; Valeggia, Claudia; Jasienska, Grazyna; Hinde, Katie
2017-01-01
Human milk contains essential micronutrients for growth and development during early life. Environmental pollutants, such as potentially toxic metals, can also be transferred to the infant through human milk. These elements have been well-studied, but changing diets and environments and advances in laboratory technology require re-examining these elements in a variety of settings. The aim of this study was to characterize the concentrations of essential and toxic metals in human milk from four diverse populations. Human milk samples (n = 70) were collected in Argentina (n = 21), Namibia (n = 6), Poland (n = 23), and the United States (n = 20) using a standardized mid-feed collection procedure. Milk concentrations of calcium, zinc, iron, copper, manganese, lead, arsenic, and cadmium were determined using inductively coupled plasma mass spectrometry (ICP-MS). We used standard multiple linear regression models to evaluate differences among populations, while including infant age, infant sex, and maternal parity status (multiparous or primiparous) as covariates. Concentrations of all elements, except zinc, varied across populations after controlling for infant age, infant sex, and maternal parity. Calcium and magnesium showed more differences across populations than iron or copper. There were no significant differences among population in zinc concentrations. Mean concentrations of lead, but not arsenic, were low compared to recently published values from other populations. The concentrations of trace elements in human milk are variable among populations. Limitations due to small sample sizes and environmental contamination of some samples prevent us from drawing robust conclusions about the causes of these differences.
Breakey, Alicia A.; Scelza, Brooke; Valeggia, Claudia; Jasienska, Grazyna; Hinde, Katie
2017-01-01
Human milk contains essential micronutrients for growth and development during early life. Environmental pollutants, such as potentially toxic metals, can also be transferred to the infant through human milk. These elements have been well-studied, but changing diets and environments and advances in laboratory technology require re-examining these elements in a variety of settings. The aim of this study was to characterize the concentrations of essential and toxic metals in human milk from four diverse populations. Human milk samples (n = 70) were collected in Argentina (n = 21), Namibia (n = 6), Poland (n = 23), and the United States (n = 20) using a standardized mid-feed collection procedure. Milk concentrations of calcium, zinc, iron, copper, manganese, lead, arsenic, and cadmium were determined using inductively coupled plasma mass spectrometry (ICP-MS). We used standard multiple linear regression models to evaluate differences among populations, while including infant age, infant sex, and maternal parity status (multiparous or primiparous) as covariates. Concentrations of all elements, except zinc, varied across populations after controlling for infant age, infant sex, and maternal parity. Calcium and magnesium showed more differences across populations than iron or copper. There were no significant differences among population in zinc concentrations. Mean concentrations of lead, but not arsenic, were low compared to recently published values from other populations. The concentrations of trace elements in human milk are variable among populations. Limitations due to small sample sizes and environmental contamination of some samples prevent us from drawing robust conclusions about the causes of these differences. PMID:28817665
Boufana, B; Lett, W; Lahmar, S; Griffiths, A; Jenkins, D J; Buishi, I; Engliez, S A; Alrefadi, M A; Eljaki, A A; Elmestiri, F M; Reyes, M M; Pointing, S; Al-Hindi, A; Torgerson, P R; Okamoto, M; Craig, P S
2015-11-01
Canids, particularly dogs, constitute the major source of cystic echinococcosis (CE) infection to humans, with the majority of cases being caused by Echinococcus granulosus (G1 genotype). Canine echinococcosis is an asymptomatic disease caused by adult tapeworms of E. granulosus sensu lato (s.l.). Information on the population structure and genetic variation of adult E. granulosus is limited. Using sequenced data of the mitochondrial cytochrome c oxidase subunit 1 (cox1) we examined the genetic diversity and population structure of adult tapeworms of E. granulosus (G1 genotype) from canid definitive hosts originating from various geographical regions and compared it to that reported for the larval metacestode stage from sheep and human hosts. Echinococcus granulosus (s.s) was identified from adult tapeworm isolates from Kenya, Libya, Tunisia, Australia, China, Kazakhstan, United Kingdom and Peru, including the first known molecular confirmation from Gaza and the Falkland Islands. Haplotype analysis showed a star-shaped network with a centrally positioned common haplotype previously described for the metacestode stage from sheep and humans, and the neutrality indices indicated population expansion. Low Fst values suggested that populations of adult E. granulosus were not genetically differentiated. Haplotype and nucleotide diversities for E. granulosus isolates from sheep and human origin were twice as high as those reported from canid hosts. This may be related to self-fertilization of E. granulosus and/or to the longevity of the parasite in the respective intermediate and definitive hosts. Improved nuclear single loci are required to investigate the discrepancies in genetic variation seen in this study.
Campos, Paula F.; Willerslev, Eske; Sher, Andrei; Orlando, Ludovic; Axelsson, Erik; Tikhonov, Alexei; Aaris-Sørensen, Kim; Greenwood, Alex D.; Kahlke, Ralf-Dietrich; Kosintsev, Pavel; Krakhmalnaya, Tatiana; Kuznetsova, Tatyana; Lemey, Philippe; MacPhee, Ross; Norris, Christopher A.; Shepherd, Kieran; Suchard, Marc A.; Zazula, Grant D.; Shapiro, Beth; Gilbert, M. Thomas P.
2010-01-01
The causes of the late Pleistocene megafaunal extinctions are poorly understood. Different lines of evidence point to climate change, the arrival of humans, or a combination of these events as the trigger. Although many species went extinct, others, such as caribou and bison, survived to the present. The musk ox has an intermediate story: relatively abundant during the Pleistocene, it is now restricted to Greenland and the Arctic Archipelago. In this study, we use ancient DNA sequences, temporally unbiased summary statistics, and Bayesian analytical techniques to infer musk ox population dynamics throughout the late Pleistocene and Holocene. Our results reveal that musk ox genetic diversity was much higher during the Pleistocene than at present, and has undergone several expansions and contractions over the past 60,000 years. Northeast Siberia was of key importance, as it was the geographic origin of all samples studied and held a large diverse population until local extinction at ≈45,000 radiocarbon years before present (14C YBP). Subsequently, musk ox genetic diversity reincreased at ca. 30,000 14C YBP, recontracted at ca. 18,000 14C YBP, and finally recovered in the middle Holocene. The arrival of humans into relevant areas of the musk ox range did not affect their mitochondrial diversity, and both musk ox and humans expanded into Greenland concomitantly. Thus, their population dynamics are better explained by a nonanthropogenic cause (for example, environmental change), a hypothesis supported by historic observations on the sensitivity of the species to both climatic warming and fluctuations. PMID:20212118
The Asian Taenia and the possibility of cysticercosis
V. Fuentes, Màrius
2000-01-01
In certain Asian countries, a third form of human Taenia, also known as the Asian Taenia, has been discovered. This Asian Taenia seems to be an intermediate between Taenia solium and T. saginata since in morphological terms it is similar to T. saginata, yet biologically, as it uses the same intermediate host (pigs), it is more akin to T. solium. Taenia solium causes human cysticercosis, while T. saginata does not. It is not known whether the Asian taeniid is able to develop to the larval stage in humans or not. The arguments proposed by those authors who consider it unlikely that the Asian Taenia causes human cysticercosis are: (a) its molecular similarities with T. saginata; (b) the absence of cases of human cysticercosis in populations where the Asian adult is highly prevalent; and (c) the unsupporting results derived from an experimental infestation study. These three arguments are debated, although bearing in mind that at present there is still no clear scientific data to support that human cysticercosis can be caused by the Asian Taenia. PMID:10743352
Pandemic Threat Posed by Avian Influenza A Viruses
Horimoto, Taisuke; Kawaoka, Yoshihiro
2001-01-01
Influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. The last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. In 1997, an H5N1 influenza virus was directly transmitted from birds in live poultry markets in Hong Kong to humans. Eighteen people were infected in this outbreak, six of whom died. This avian virus exhibited high virulence in both avian and mammalian species, causing systemic infection in both chickens and mice. Subsequently, another avian virus with the H9N2 subtype was directly transmitted from birds to humans in Hong Kong. Interestingly, the genes encoding the internal proteins of the H9N2 virus are genetically highly related to those of the H5N1 virus, suggesting a unique property of these gene products. The identification of avian viruses in humans underscores the potential of these and similar strains to produce devastating influenza outbreaks in major population centers. Although highly pathogenic avian influenza viruses had been identified before the 1997 outbreak in Hong Kong, their devastating effects had been confined to poultry. With the Hong Kong outbreak, it became clear that the virulence potential of these viruses extended to humans. PMID:11148006
Ching-Yu Huang; Grizelle Gonzalez; Paul F. Hendrix
2006-01-01
Populations of some native earthworm species are decreasing or disappearing due to human activities like habitat disturbance and introduction of exotic earthworms. Habitat disturbance can cause changes in soil physical structure and nutrient cycling, which may reduce native earthworm populations prior to the invasion of exotic earthworms. Our purpose was 1) to...
ERIC Educational Resources Information Center
Davidson, J.
Uneven economic growth, rapid population increases, and high costs of fossil fuels have caused much of the human race to experience an energy crisis. For the world's poor people the energy requirements consist mainly of firewood. This crisis will be aggravated further as population trends begin to overwhelm natural resources. Future demands for…
Russell, Shirley B.; Smith, Joan C.; Huang, Minjun; Trupin, Joel S.; Williams, Scott M.
2015-01-01
Many diseases are differentially distributed among human populations. Differential selection on genetic variants in ancestral environments that coincidentally predispose to disease can be an underlying cause of these unequal prevalence patterns. Selected genes may be pleiotropic, affecting multiple phenotypes and resulting in more than one disease or trait. Patterns of pleiotropy may be helpful in understanding the underlying causes of an array of conditions in a population. For example, several fibroproliferative diseases are more prevalent and severe in populations of sub-Saharan ancestry. We propose that this disparity is due to selection for an enhanced Th2 response that confers resistance to helminthic infections, and concurrently increases susceptibility to fibrosis due to the profibrotic action of Th2 cytokines. Many studies on selection of Th2-related genes for host resistance to helminths have been reported, but the pleiotropic impact of this selection on the distribution of fibrotic disorders has not been explicitly investigated. We discuss the disproportionate occurrence of fibroproliferative diseases in individuals of African ancestry and provide evidence that adaptation of the immune system has shaped the genetic structure of these human populations in ways that alter the distribution of multiple fibroproliferative diseases. PMID:26540410
Climate change, human health, and epidemiological transition.
Barrett, Bruce; Charles, Joel W; Temte, Jonathan L
2015-01-01
The health of populations depends on the availability of clean air, water, food, and sanitation, exposure to pathogens, toxins and environmental hazards, and numerous genetic, behavioral and social factors. For many thousands of years, human life expectancy was low, and population growth was slow. The development of technology-based civilizations facilitated what Abdel Omran called "epidemiological transition," with increasing life expectancy and rapid population growth. To a large extent, the spectacular growth of human populations during the past two centuries was made possible by the energy extracted from fossil fuels. We have now learned, however, that greenhouse gases from fossil fuel combustion are warming the planet's surface, causing changes in oceanic and atmospheric systems, and disrupting weather and hydrological patterns. Climate change poses unprecedented threats to human health by impacts on food and water security, heat waves and droughts, violent storms, infectious disease, and rising sea levels. Whether or not humanity can reduce greenhouse gas emissions quickly enough to slow climate change to a rate that will allow societies to successfully adapt is not yet known. This essay reviews the current state of relevant knowledge, and points in a few directions that those interested in human health may wish to consider. Copyright © 2014 Elsevier Inc. All rights reserved.
Ruiz-Fons, F
2017-02-01
Many wild swine populations in different parts of the World have experienced an unprecedented demographic explosion that may result in increased exposure of humans to wild swine zoonotic pathogens. Interactions between humans and wild swine leading to pathogen transmission could come from different ways, being hunters and game professionals the most exposed to acquiring infections from wild swine. However, increasing human settlements in semi-natural areas, outdoor activities, socio-economic changes and food habits may increase the rate of exposure to wild swine zoonotic pathogens and to potentially emerging pathogens from wild swine. Frequent and increasing contact rate between humans and wild swine points to an increasing chance of zoonotic pathogens arising from wild swine to be transmitted to humans. Whether this frequent contact could lead to new zoonotic pathogens emerging from wild swine to cause human epidemics or emerging disease outbreaks is difficult to predict, and assessment should be based on thorough epidemiologic surveillance. Additionally, several gaps in knowledge on wild swine global population dynamics trends and wild swine-zoonotic pathogen interactions should be addressed to correctly assess the potential role of wild swine in the emergence of diseases in humans. In this work, viruses such as hepatitis E virus, Japanese encephalitis virus, Influenza virus and Nipah virus, and bacteria such as Salmonella spp., Shiga toxin-producing Escherichia coli, Campylobacter spp. and Leptospira spp. have been identified as the most prone to be transmitted from wild swine to humans on the basis of geographic spread in wild swine populations worldwide, pathogen circulation rates in wild swine populations, wild swine population trends in endemic areas, susceptibility of humans to infection, transmissibility from wild swine to humans and existing evidence of wild swine-human transmission events. © 2015 Blackwell Verlag GmbH.
On avian influenza epidemic models with time delay.
Liu, Sanhong; Ruan, Shigui; Zhang, Xinan
2015-12-01
After the outbreak of the first avian influenza A virus (H5N1) in Hong Kong in 1997, another avian influenza A virus (H7N9) crossed the species barrier in mainland China in 2013 and 2014 and caused more than 400 human cases with a death rate of nearly 40%. In this paper, we take account of the incubation periods of avian influenza A virus and construct a bird-to-human transmission model with different time delays in the avian and human populations combining the survival probability of the infective avian and human populations at the latent time. By analyzing the dynamical behavior of the model, we obtain a threshold value for the prevalence of avian influenza and investigate local and global asymptotical stability of equilibria of the system.
Random genetic drift, natural selection, and noise in human cranial evolution.
Roseman, Charles C
2016-08-01
This study assesses the extent to which relationships among groups complicate comparative studies of adaptation in recent human cranial variation and the extent to which departures from neutral additive models of evolution hinder the reconstruction of population relationships among groups using cranial morphology. Using a maximum likelihood evolutionary model fitting approach and a mixed population genomic and cranial data set, I evaluate the relative fits of several widely used models of human cranial evolution. Moreover, I compare the goodness of fit of models of cranial evolution constrained by genomic variation to test hypotheses about population specific departures from neutrality. Models from population genomics are much better fits to cranial variation than are traditional models from comparative human biology. There is not enough evolutionary information in the cranium to reconstruct much of recent human evolution but the influence of population history on cranial variation is strong enough to cause comparative studies of adaptation serious difficulties. Deviations from a model of random genetic drift along a tree-like population history show the importance of environmental effects, gene flow, and/or natural selection on human cranial variation. Moreover, there is a strong signal of the effect of natural selection or an environmental factor on a group of humans from Siberia. The evolution of the human cranium is complex and no one evolutionary process has prevailed at the expense of all others. A holistic unification of phenome, genome, and environmental context, gives us a strong point of purchase on these problems, which is unavailable to any one traditional approach alone. Am J Phys Anthropol 160:582-592, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Schultsz, Constance; Jansen, Ewout; Keijzers, Wendy; Rothkamp, Anja; Duim, Birgitta; Wagenaar, Jaap A; van der Ende, Arie
2012-01-01
Streptococcus suis serotype 2 is the main cause of zoonotic S. suis infection despite the fact that other serotypes are frequently isolated from diseased pigs. Studies comparing concurrent invasive human and pig isolates from a single geographical location are lacking. We compared the population structures of invasive S. suis strains isolated between 1986 and 2008 from human patients (N = 24) and from pigs with invasive disease (N = 124) in The Netherlands by serotyping and multi locus sequence typing (MLST). Fifty-six percent of pig isolates were of serotype 9 belonging to 15 clonal complexes (CCs) or singleton sequence types (ST). In contrast, all human isolates were of serotype 2 and belonged to two non-overlapping clonal complexes CC1 (58%) and CC20 (42%). The proportion of serotype 2 isolates among S. suis strains isolated from humans was significantly higher than among strains isolated from pigs (24/24 vs. 29/124; P<0.0001). This difference remained significant when only strains within CC1 and CC20 were considered (24/24 vs. 27/37,P = 0.004). The Simpson diversity index of the S. suis population isolated from humans (0.598) was smaller than of the population isolated from pigs (0.765, P = 0.05) indicating that the S. suis population isolated from infected pigs was more diverse than the S. suis population isolated from human patients. S. suis serotype 2 strains of CC20 were all negative in a PCR for detection of genes encoding extracellular protein factor (EF) variants. These data indicate that the polysaccharide capsule is an important correlate of human S. suis infection, irrespective of the ST and EF encoding gene type of S. suis strains.
Martins, Alexandra; Guilhermino, Lúcia
2018-08-01
The environmental contamination by microplastics is a global challenge to ecosystem and human health, and the knowledge on the long-term effects of such particles is limited. Thus, the effects of microplastics and post-exposure recovery were investigated over 4 generations (F 0 , F 1 , F 2 , F 3 ) using Daphnia magna as model. Effect criteria were parental mortality, growth, several reproductive parameters, and population growth rate. Microplastics exposure (0.1mg/l of pristine polymer microspheres 1-5μm diameter) caused parental mortality (10-100%), and significantly (p≤0.05) decreased growth, reproduction, and population growth rate leading to the extinction of the microplastics-exposed model population in the F 1 generation. Females descending from those exposed to microplastics in F 0 and exposed to clean medium presented some recovery but up to the F 3 generation they still had significantly (p≤0.05) reduced growth, reproduction, and population growth rate. Overall, these results indicate that D. magna recovery from chronic exposure to microplastics may take several generations, and that the continuous exposure over generations to microplastics may cause population extinction. These findings have implications to aquatic ecosystem functioning and services, and raise concern on the long-term animal and human exposure to microplastics through diverse routes. Copyright © 2018. Published by Elsevier B.V.
Fine-scale population structure and the era of next-generation sequencing.
Henn, Brenna M; Gravel, Simon; Moreno-Estrada, Andres; Acevedo-Acevedo, Suehelay; Bustamante, Carlos D
2010-10-15
Fine-scale population structure characterizes most continents and is especially pronounced in non-cosmopolitan populations. Roughly half of the world's population remains non-cosmopolitan and even populations within cities often assort along ethnic and linguistic categories. Barriers to random mating can be ecologically extreme, such as the Sahara Desert, or cultural, such as the Indian caste system. In either case, subpopulations accumulate genetic differences if the barrier is maintained over multiple generations. Genome-wide polymorphism data, initially with only a few hundred autosomal microsatellites, have clearly established differences in allele frequency not only among continental regions, but also within continents and within countries. We review recent evidence from the analysis of genome-wide polymorphism data for genetic boundaries delineating human population structure and the main demographic and genomic processes shaping variation, and discuss the implications of population structure for the distribution and discovery of disease-causing genetic variants, in the light of the imminent availability of sequencing data for a multitude of diverse human genomes.
Comparative Demography of an At-Risk African Elephant Population
Wittemyer, George; Daballen, David; Douglas-Hamilton, Iain
2013-01-01
Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human impacts (laying the foundation for modeling approaches), supporting predictions of evolutionary theory regarding demographic responses to ecological processes. PMID:23341984
Comparative demography of an at-risk African elephant population.
Wittemyer, George; Daballen, David; Douglas-Hamilton, Iain
2013-01-01
Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human impacts (laying the foundation for modeling approaches), supporting predictions of evolutionary theory regarding demographic responses to ecological processes.
Köndgen, Sophie; Calvignac-Spencer, Sebastien; Grützmacher, Kim; Keil, Verena; Mätz-Rensing, Kerstin; Nowak, Kathrin; Metzger, Sonja; Kiyang, John; Becker, Antina Lübke; Deschner, Tobias; Wittig, Roman M; Lankester, Felix; Leendertz, Fabian H
2017-11-06
Habituation of wild great apes for tourism and research has had a significant positive effect on the conservation of these species. However, risks associated with such activities have been identified, specifically the transmission of human respiratory viruses to wild great apes, causing high morbidity and, occasionally, mortality. Here, we investigate the source of bacterial-viral co-infections in wild and captive chimpanzee communities in the course of several respiratory disease outbreaks. Molecular analyses showed that human respiratory syncytial viruses (HRSV) and human metapneumoviruses (HMPV) were involved in the etiology of the disease. In addition our analysis provide evidence for coinfection with Streptococcus (S.) pneumoniae. Characterisation of isolates from wild chimpanzees point towards a human origin of these bacteria. Transmission of these bacteria is of concern because - in contrast to HRSV and HMPV - S. pneumoniae can become part of the nasopharyngeal flora, contributing to the severity of respiratory disease progression. Furthermore these bacteria have the potential to spread to other individuals in the community and ultimately into the population. Targeted vaccination programs could be used to vaccinate habituated great apes but also human populations around great ape habitats, bringing health benefits to both humans and wild great apes.
Genetic Mechanisms Involved in the Phenotype of Down Syndrome
ERIC Educational Resources Information Center
Patterson, David
2007-01-01
Down syndrome (DS) is the most common genetic cause of significant intellectual disability in the human population, occurring in roughly 1 in 700 live births. The ultimate cause of DS is trisomy of all or part of the set of genes located on chromosome 21. How this trisomy leads to the phenotype of DS is unclear. The completion of the DNA…
Polednak, Anthony P
2014-08-01
To enhance surveillance of mortality from oral cavity-pharynx cancer (OCPC) by considering inaccuracies in the cancer site coded as the underlying cause of death on death certificates vs. cancer site in a population-based cancer registry (as the gold standard). A database was used for 9 population-based cancer registries of the Surveillance, Epidemiology and End Results (SEER) Program, including deaths in 1999-2010 for patients diagnosed in 1973-2010. Numbers of deaths and death rates for OCPC in the SEER population were modified for apparent inaccuracies in the cancer site coded as the underlying cause of death. For age groups <65 years, deaths from OCPC were underestimated by 22-35% by using unmodified (vs. modified) numbers, but temporal declines in death rates were still evident in the SEER population and were similar to declines using routine mortality data for the entire U.S. population. Deaths were underestimated by about 70-80% using underlying cause for tonsillar cancers, strongly associated with human papillomavirus (HPV) infection, but a lack of decline in death rates was still evident. Routine mortality statistics based on underlying cause of death underestimate OCPC deaths but demonstrate trends in OCPC death rates that require continued surveillance in view of increasing incidence rates for HPV-related OCPC. Copyright © 2014 Elsevier Ltd. All rights reserved.
Shi, Lei; Hu, Enzhi; Wang, Zhenbo; Liu, Jiewei; Li, Jin; Li, Ming; Chen, Hua; Yu, Chunshui; Jiang, Tianzi; Su, Bing
2017-02-01
Human evolution is marked by a continued enlargement of the brain. Previous studies on human brain evolution focused on identifying sequence divergences of brain size regulating genes between humans and nonhuman primates. However, the evolutionary pattern of the brain size regulating genes during recent human evolution is largely unknown. We conducted a comprehensive analysis of the brain size regulating gene CASC5 and found that in recent human evolution, CASC5 has accumulated many modern human specific amino acid changes, including two fixed changes and six polymorphic changes. Among human populations, 4 of the 6 amino acid polymorphic sites have high frequencies of derived alleles in East Asians, but are rare in Europeans and Africans. We proved that this between-population allelic divergence was caused by regional Darwinian positive selection in East Asians. Further analysis of brain image data of Han Chinese showed significant associations of the amino acid polymorphic sites with gray matter volume. Hence, CASC5 may contribute to the morphological and structural changes of the human brain during recent evolution. The observed between-population divergence of CASC5 variants was driven by natural selection that tends to favor a larger gray matter volume in East Asians.
Spatiotemporal dynamics of Puumala hantavirus associated with its rodent host, Myodes glareolus
Weber de Melo, Vanessa; Sheikh Ali, Hanan; Freise, Jona; Kühnert, Denise; Essbauer, Sandra; Mertens, Marc; Wanka, Konrad M; Drewes, Stephan; Ulrich, Rainer G; Heckel, Gerald
2015-01-01
Many viruses significantly impact human and animal health. Understanding the population dynamics of these viruses and their hosts can provide important insights for epidemiology and virus evolution. Puumala virus (PUUV) is a European hantavirus that may cause regional outbreaks of hemorrhagic fever with renal syndrome in humans. Here, we analyzed the spatiotemporal dynamics of PUUV circulating in local populations of its rodent reservoir host, the bank vole (Myodes glareolus) during eight years. Phylogenetic and population genetic analyses of all three genome segments of PUUV showed strong geographical structuring at a very local scale. There was a high temporal turnover of virus strains in the local bank vole populations, but several virus strains persisted through multiple years. Phylodynamic analyses showed no significant changes in the local effective population sizes of PUUV, although vole numbers and virus prevalence fluctuated widely. Microsatellite data demonstrated also a temporally persisting subdivision between local vole populations, but these groups did not correspond to the subdivision in the virus strains. We conclude that restricted transmission between vole populations and genetic drift play important roles in shaping the genetic structure and temporal dynamics of PUUV in its natural host which has several implications for zoonotic risks of the human population. PMID:26136821
ERIC Educational Resources Information Center
Balcombe, Jonathan
Killing animals for classroom dissection causes animal suffering, cheapens the value of life, and depletes wild animal populations, yet it remains commonplace. The Humane Society of the United States (HSUS) addresses the issue in this information packet which includes a fact sheet and three resource lists "on Dissection." The fact sheet discusses…
The Earth Sciences, Human Well-Being, and the Reduction of Global Poverty
NASA Astrophysics Data System (ADS)
Mutter, John C.
2005-04-01
Poverty is not solely a social or political matter, nor is it caused simply by population pressures as Thomas Malthus postulated in 1798. A new understanding of poverty is emerging in which natural and environmental drivers, together with social, political, and demographic causes, underpin livelihoods. The Earth sciences, therefore, play a critical role in identifying the deep causes of human suffering and in identifying solutions. The State of the Planet: Why Are So Many So Poor? For far too many, the state of human well-being is bleak. Around one in six human beings-1 billion people-live in extreme poverty, struggling to survive on less than $1 a day; another one sixth of humanity ekes out existence on $2 per day (U.N. Development Programme (UNDP) Human Development Report, 2004; http://hdr.undp.org/2004/). The extreme poor lack all normal attributes of a decent, dignified life: adequate food, housing, sanitation, health care, education, and employment. Some 800 million people lack sufficient nourishment almost every day. It stunts their mental and physical development and shortens their lives, making them susceptible to common illnesses that attack their hunger-weakened bodies. Poor nutrition in mothers and infants is the leading cause of reduced disability-adjusted life years in poor countries [ Economist, 2004].
NASA Astrophysics Data System (ADS)
Contreras, Christy; McKay, John; Blattman, Joseph; Holechek, Susan
2015-03-01
The lymphocytic choriomenigitis virus (LCMV) is a rodent-spread virus commonly recognized as causing neurological disease that exhibits asymptomatic pathology. The virus is a pathogen normally carried among rodents that can be transmitted to humans by direct or indirect contact with the virus in excretions and secretions from rodents and can cause aseptic meningitis and other conditions in humans. We consider an epidemiological system within rodent populations modeled by a system of ordinary differential equations that captures the dynamics of the diseases transmission and present our findings. The asymptotic nature of the pathogen plays a large role in its spread within a given population, which has motivated us to expand upon an existing SIRC model (Holechek et al in preparation) that accounts for susceptible-, infected-, recovered-, and carrier-mice on the basis of their gender. We are interested in observing and determining the conditions under which the carrier population will reach a disease free equilibrium, and we focus our investigation on the sensitivity of our model to gender, pregnancy related infection, and reproduction rate conditions.
Genetic characterization of an epidemic of Plasmodium falciparum malaria among Yanomami Amerindians.
Laserson, K F; Petralanda, I; Almera, R; Barker, R H; Spielman, A; Maguire, J H; Wirth, D F
1999-12-01
Malaria parasites are genetically diverse at all levels of endemicity. In contrast, the merozoite surface protein (MSP) alleles in samples from 2 isolated populations of Yanomami Amerindians during an epidemic of Plasmodium falciparum were identical. The nonvariable restriction fragment length polymorphism patterns further suggested that the sequential outbreak comprised only a single P. falciparum genotype. By examination of serial samples from single human infections, the MSP characteristics were found to remain constant throughout the course of infection. An apparent clonal population structure of parasites seemed to cause outbreaks in small isolated villages. The use of standard molecular epidemiologic methods to measure genetic diversity in malaria revealed the occurrence of a genetically monomorphic population of P. falciparum within a human community.
Morach, Marina; Stephan, Roger; Schmitt, Sarah; Ewers, Christa; Zschöck, Michael; Reyes-Velez, Julian; Gilli, Urs; Del Pilar Crespo-Ortiz, María; Crumlish, Margaret; Gunturu, Revathi; Daubenberger, Claudia A; Ip, Margaret; Regli, Walter; Johler, Sophia
2018-03-01
Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults, in addition to various animal species worldwide. Still, information on the population structure of S. agalactiae and the geographical distribution of different clones is limited. Further data are urgently needed to identify particularly successful clones and obtain insights into possible routes of transmission within one host species and across species borders. We aimed to determine the population structure and virulence gene profiles of S. agalactiae strains from a diverse set of sources and geographical origins. To this end, 373 S. agalactiae isolates obtained from humans and animals from five different continents were typed by DNA microarray profiling. A total of 242 different S. agalactiae strains were identified and further analyzed. Particularly successful clonal lineages, hybridization patterns, and strains were identified that were spread across different continents and/or were present in more than one host species. In particular, several strains were detected in both humans and cattle, and several canine strains were also detected in samples from human, bovine, and porcine hosts. The findings of our study suggest that although S. agalactiae is well adapted to various hosts including humans, cattle, dogs, rodents, and fish, interspecies transmission is possible and occurs between humans and cows, dogs, and rabbits. The virulence and resistance gene profiles presented enable new insights into interspecies transmission and make a crucial contribution to the identification of suitable targets for therapeutic agents and vaccines.
Human antibody technology and the development of antibodies against cytomegalovirus.
Ohlin, Mats; Söderberg-Nauclér, Cecilia
2015-10-01
Cytomegalovirus (CMV) is a virus that causes chronic infections in a large set of the population. It may cause severe disease in immunocompromised individuals, is linked to immunosenescence and implied to play an important role in the pathogenesis of cardiovascular diseases and cancer. Modulation of the immune system's abilities to manage the virus represent a highly viable therapeutic option and passive immunotherapy with polyclonal antibody preparations is already in clinical use. Defined monoclonal antibodies offer many advantages over polyclonal antibodies purified from serum. Human CMV-specific monoclonal antibodies have consequently been thoroughly investigated with respect to their potential in the treatment of diseases caused by CMV. Recent advances in human antibody technology have substantially expanded the breadth of antibodies for such applications. This review summarizes the fundamental basis for treating CMV disease by use of antibodies, the basic technologies to be used to develop such antibodies, and relevant human antibody specificities available to target this virus. Copyright © 2015 Elsevier Ltd. All rights reserved.
Travel and the emergence of infectious diseases.
Wilson, M. E.
1995-01-01
Travel is a potent force in the emergence of disease. Migration of humans has been the pathway for disseminating infectious diseases throughout recorded history and will continue to shape the emergence, frequency, and spread of infections in geographic areas and populations. The current volume, speed, and reach of travel are unprecedented. The consequences of travel extend beyond the traveler to the population visited and the ecosystem. When they travel, humans carry their genetic makeup, immunologic sequelae of past infections, cultural preferences, customs, and behavioral patterns. Microbes, animals, and other biologic life also accompany them. Today's massive movement of humans and materials sets the stage for mixing diverse genetic pools at rates and in combinations previously unknown. Concomitant changes in the environment, climate, technology, land use, human behavior, and demographics converge to favor the emergence of infectious diseases caused by a broad range of organisms in humans, as well as in plants and animals. PMID:8903157
Mourad W. Gabriel; Leslie W. Woods; Greta M. Wengert; Nicole Stephenson; J. Mark Higley; Craig Thompson; Sean M. Matthews; Rick A. Sweitzer; Kathryn Purcell; Reginald H. Barrett; Stefan M. Keller; Patricia Gaffney; Megan Jones; Robert Poppenga; Janet E. Foley; Richard N. Brown; Deana L. Clifford; Benjamin N. Sacks
2015-01-01
Wildlife populations of conservation concern are limited in distribution, population size and persistence by various factors, including mortality. The fisher (Pekania pennanti), a North American mid-sized carnivore whose range in the western Pacific United States has retracted considerably in the past century, was proposed for threatened status...
The public health impact of avian influenza viruses.
Katz, J M; Veguilla, V; Belser, J A; Maines, T R; Van Hoeven, N; Pappas, C; Hancock, K; Tumpey, T M
2009-04-01
Influenza viruses with novel hemagglutinin and 1 or more accompanying genes derived from avian influenza viruses sporadically emerge in humans and have the potential to result in a pandemic if the virus causes disease and spreads efficiently in a population that lacks immunity to the novel hemagglutinin. Since 1997, multiple avian influenza virus subtypes have been transmitted directly from domestic poultry to humans and have caused a spectrum of human disease, from asymptomatic to severe and fatal. To assess the pandemic risk that avian influenza viruses pose, we have used multiple strategies to better understand the capacity of avian viruses to infect, cause disease, and transmit among mammals, including humans. Seroepidemiologic studies that evaluate the frequency and risk of human infection with avian influenza viruses in populations with exposure to domestic or wild birds can provide a better understanding of the pandemic potential of avian influenza subtypes. Investigations conducted in Hong Kong following the first H5N1 outbreak in humans in 1997 determined that exposure to poultry in live bird markets was a key risk factor for human disease. Among poultry workers, butchering and exposure to sick poultry were risk factors for antibody to H5 virus, which provided evidence for infection. A second risk assessment tool, the ferret, can be used to evaluate the level of virulence and potential for host-to-host transmission of avian influenza viruses in this naturally susceptible host. Avian viruses isolated from humans exhibit a level of virulence and transmissibility in ferrets that generally reflects that seen in humans. The ferret model thus provides a means to monitor emerging avian influenza viruses for pandemic risk, as well as to evaluate laboratory-generated reassortants and mutants to better understand the molecular basis of influenza virus transmissibility. Taken together, such studies provide valuable information with which we can assess the public health risk of avian influenza viruses.
Dog population management for the control of human echinococcosis.
Kachani, Malika; Heath, David
2014-11-01
Cystic and alveolar hydatid disease of humans caused by infection with Echinococcus granulosus or Echinococcus multilocularis are significant zoonoses in developing countries. For human infections, the main definitive host is the dog, and reduction in the population of unwanted dogs, together with anthelmintic treatment of wanted dogs, are recommended control procedures for these zoonoses. Both owned and unowned dogs have been shown to be a major source of Echinococcus spp. infection in developing countries. Unowned dogs are the most challenging category in dog population management for the control of major zoonotic diseases. Unowned dogs are those dogs that do not have an owner, and those dogs whose owner cannot readily be identified. Control of numbers of unowned dogs can be done in various ways if funds are available. Fertility control and humane euthanasia are likely to be the most effective procedures in developing countries. Fertility control requires significant funding, and where resources are scarce humane euthanasia may be the most effective option. Both procedures are ongoing events, with no predictable end point. This paper examines the sociology and technology for the population management of owned and unowned dogs, specifically for the reduction of human hydatid disease. Examples are given for developing and developed countries. Although a "One Health" approach is desirable, the technology for hydatid control is different from that for rabies, and FAO Animal Welfare recommendations for dog population management should be adjusted accordingly. Copyright © 2014 Elsevier B.V. All rights reserved.
Report of two paediatric cases of central line infections caused by species of the genus Kocuria
Hamula, Camille L.; Dingle, Tanis C.
2016-01-01
Introduction: Species of the genus Kocuria are Gram-positive cocci of the family Micrococcacceae that are ubiquitous in the environment and part of the normal skin and oral flora in humans. A paucity of cases have been reported of Kocuria as human pathogens and there are currently no evidence-based guidelines for managing these uncommon infections. Case presentation: We present two paediatric cases of central line infections with species of the genus Kocuria that required line removal despite antimicrobial therapy. Conclusion: Species of the genus Kocuria are uncommon human pathogens that have rarely been reported to cause opportunistic infections in both adult and paediatric populations. The cases presented here add to the growing body of literature documenting the pathogenicity of these organisms and the possible need for line removal to achieve clinical cure in central line-associated bacteraemia caused by species of the genus Kocuria. PMID:28348760
T Cell Inactivation by Poxviral B22 Family Proteins Increases Viral Virulence
Alzhanova, Dina; Hammarlund, Erika; Reed, Jason; Meermeier, Erin; Rawlings, Stephanie; Ray, Caroline A.; Edwards, David M.; Bimber, Ben; Legasse, Alfred; Planer, Shannon; Sprague, Jerald; Axthelm, Michael K.; Pickup, David J.; Lewinsohn, David M.; Gold, Marielle C.; Wong, Scott W.; Sacha, Jonah B.; Slifka, Mark K.; Früh, Klaus
2014-01-01
Infections with monkeypox, cowpox and weaponized variola virus remain a threat to the increasingly unvaccinated human population, but little is known about their mechanisms of virulence and immune evasion. We now demonstrate that B22 proteins, encoded by the largest genes of these viruses, render human T cells unresponsive to stimulation of the T cell receptor by MHC-dependent antigen presentation or by MHC-independent stimulation. In contrast, stimuli that bypass TCR-signaling are not inhibited. In a non-human primate model of monkeypox, virus lacking the B22R homologue (MPXVΔ197) caused only mild disease with lower viremia and cutaneous pox lesions compared to wild type MPXV which caused high viremia, morbidity and mortality. Since MPXVΔ197-infected animals displayed accelerated T cell responses and less T cell dysregulation than MPXV US2003, we conclude that B22 family proteins cause viral virulence by suppressing T cell control of viral dissemination. PMID:24832205
T cell inactivation by poxviral B22 family proteins increases viral virulence.
Alzhanova, Dina; Hammarlund, Erika; Reed, Jason; Meermeier, Erin; Rawlings, Stephanie; Ray, Caroline A; Edwards, David M; Bimber, Ben; Legasse, Alfred; Planer, Shannon; Sprague, Jerald; Axthelm, Michael K; Pickup, David J; Lewinsohn, David M; Gold, Marielle C; Wong, Scott W; Sacha, Jonah B; Slifka, Mark K; Früh, Klaus
2014-05-01
Infections with monkeypox, cowpox and weaponized variola virus remain a threat to the increasingly unvaccinated human population, but little is known about their mechanisms of virulence and immune evasion. We now demonstrate that B22 proteins, encoded by the largest genes of these viruses, render human T cells unresponsive to stimulation of the T cell receptor by MHC-dependent antigen presentation or by MHC-independent stimulation. In contrast, stimuli that bypass TCR-signaling are not inhibited. In a non-human primate model of monkeypox, virus lacking the B22R homologue (MPXVΔ197) caused only mild disease with lower viremia and cutaneous pox lesions compared to wild type MPXV which caused high viremia, morbidity and mortality. Since MPXVΔ197-infected animals displayed accelerated T cell responses and less T cell dysregulation than MPXV US2003, we conclude that B22 family proteins cause viral virulence by suppressing T cell control of viral dissemination.
[Human ecology. Which is the main challenge to Russia?].
Velichkovskiĭ, B T
2002-01-01
The main direction in the study of human ecology in Russia today is to provide evidence for how to maintain environmental balance in the biosphere of the Earth, though the above factor also exerts a constantly growing negative impact on the health and life quality of the population. During the years of the reforms in the country, all the principal medical and demographic indices have undergone negative changes. To overcome the medicodemographic crisis should be now a priority problem to be solved in human ecology in Russia. The crisis was mainly caused by the "shock" strategy of the reforms. To eliminate the negative medicodemographic consequences, a strong working motivation should be firstly created for the population, that is to create such conditions that allow people to earn well-deserved living by honest work. All this requires the development of small business, democratization of private property forms of private property, and changes in the Government's policy concerning work payment. Medical scientists should clarify how biological mechanisms, that is negative social, economic and psychological factors, cause a drastic increase in mortality, particularly in the able-bodied population. This process is likely to involve three regulation levels; the central nervous system (dynamic stereotype break, as called by I. P. Pavlov), the neuroendocrine system (great stress, as described by G. Selye), molecular-cellular free radical processes (phenoptosis, as outlined by V. P. Skulachev). Five factors that most negatively affect human health and demographic processes were identified.
Nature and Nurture: the complex genetics of myopia and refractive error
Wojciechowski, Robert
2010-01-01
The refractive errors, myopia and hyperopia, are optical defects of the visual system that can cause blurred vision. Uncorrected refractive errors are the most common causes of visual impairment worldwide. It is estimated that 2.5 billion people will be affected by myopia alone with in the next decade. Experimental, epidemiological and clinical research has shown that refractive development is influenced by both environmental and genetic factors. Animal models have demonstrated that eye growth and refractive maturation during infancy are tightly regulated by visually-guided mechanisms. Observational data in human populations provide compelling evidence that environmental influences and individual behavioral factors play crucial roles in myopia susceptibility. Nevertheless, the majority of the variance of refractive error within populations is thought to be due to hereditary factors. Genetic linkage studies have mapped two dozen loci, while association studies have implicated more than 25 different genes in refractive variation. Many of these genes are involved in common biological pathways known to mediate extracellular matrix composition and regulate connective tissue remodeling. Other associated genomic regions suggest novel mechanisms in the etiology of human myopia, such as mitochondrial-mediated cell death or photoreceptor-mediated visual signal transmission. Taken together, observational and experimental studies have revealed the complex nature of human refractive variation, which likely involves variants in several genes and functional pathways. Multiway interactions between genes and/or environmental factors may also be important in determining individual risks of myopia, and may help explain the complex pattern of refractive error in human populations. PMID:21155761
INDIVIDUAL AND POPULATION RESPONSES TO ABIOTIC STRESSES IN ITALIAN RYEGRASS
Expected changes in environmental factors will alter productivity of agroecosystems and influence the distribution of agricultural pests. In addition to the natural factors that cause stress, humans introduce chemical pesticides into the agricultural environment. Weeds persist in...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-10
... ecology, population distribution and status, and actual and potential causes of decline was included in.... 764). Human activities that can impact the hyporheic zone include water diversions, sedimentation from...
Harnessing mosquito-Wolbachia symbiosis for vector and disease control.
Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Hervé C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L
2014-04-01
Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.
Curtis, Sarah W; Conneely, Karen N; Marder, Mary E; Terrell, Metrecia L; Marcus, Michele; Smith, Alicia K
2018-06-11
Endocrine-disrupting compounds (EDCs) are a broad class of chemicals present in many residential products that can disrupt hormone signaling and cause health problems in humans. Multigenerational cohorts, like the Michigan polybrominated biphenyl registry, are ideal for studying the effects of intergenerational exposure. Registry participants report hormone-related health problems, particularly in those exposed before puberty or those in the second generation exposed through placental transfer or breastfeeding. However, more research is needed to determine how EDCs cause health problems and the mechanisms underlying intergenerational exposure. Utilizing existing data in this registry, along with genetic and epigenetic approaches, could provide insight to how EDCs cause human disease and help to determine the risk to exposed populations and future generations.
Prusty, Bhupesh K.; Böhme, Linda; Bergmann, Birgit; Siegl, Christine; Krause, Eva; Mehlitz, Adrian; Rudel, Thomas
2012-01-01
Both human herpes viruses and Chlamydia are highly prevalent in the human population and are detected together in different human disorders. Here, we demonstrate that co-infection with human herpes virus 6 (HHV6) interferes with the developmental cycle of C. trachomatis and induces persistence. Induction of chlamydial persistence by HHV6 is independent of productive virus infection, but requires the interaction and uptake of the virus by the host cell. On the other hand, viral uptake is strongly promoted under co-infection conditions. Host cell glutathione reductase activity was suppressed by HHV6 causing NADPH accumulation, decreased formation of reduced glutathione and increased oxidative stress. Prevention of oxidative stress restored infectivity of Chlamydia after HHV6-induced persistence. We show that co-infection with Herpes simplex virus 1 or human Cytomegalovirus also induces chlamydial persistence by a similar mechanism suggesting that Chlamydia -human herpes virus co-infections are evolutionary shaped interactions with a thus far unrecognized broad significance. PMID:23077614
Genetic Diversity of Ascaris in China Assessed Using Simple Sequence Repeat Markers.
Zhou, Chunhua; Jian, Shaoqing; Peng, Weidong; Li, Min
2018-04-01
The giant roundworm Ascaris infects pigs and people worldwide and causes serious diseases. The taxonomic relationship between Ascaris suum and Ascaris lumbricoides is still unclear. The purpose of the present study was to investigate the genetic diversity and population genetic structure of 258 Ascaris specimens from humans and pigs from 6 sympatric regions in Ascaris -endemic regions of China using existing simple sequence repeat data. The microsatellite markers showed a high level of allelic richness and genetic diversity in the samples. Each of the populations demonstrated excess homozygosity (Ho
The Strength of Selection against Neanderthal Introgression
Juric, Ivan
2016-01-01
Hybridization between humans and Neanderthals has resulted in a low level of Neanderthal ancestry scattered across the genomes of many modern-day humans. After hybridization, on average, selection appears to have removed Neanderthal alleles from the human population. Quantifying the strength and causes of this selection against Neanderthal ancestry is key to understanding our relationship to Neanderthals and, more broadly, how populations remain distinct after secondary contact. Here, we develop a novel method for estimating the genome-wide average strength of selection and the density of selected sites using estimates of Neanderthal allele frequency along the genomes of modern-day humans. We confirm that East Asians had somewhat higher initial levels of Neanderthal ancestry than Europeans even after accounting for selection. We find that the bulk of purifying selection against Neanderthal ancestry is best understood as acting on many weakly deleterious alleles. We propose that the majority of these alleles were effectively neutral—and segregating at high frequency—in Neanderthals, but became selected against after entering human populations of much larger effective size. While individually of small effect, these alleles potentially imposed a heavy genetic load on the early-generation human–Neanderthal hybrids. This work suggests that differences in effective population size may play a far more important role in shaping levels of introgression than previously thought. PMID:27824859
Detecting and characterizing genomic signatures of positive selection in global populations.
Liu, Xuanyao; Ong, Rick Twee-Hee; Pillai, Esakimuthu Nisha; Elzein, Abier M; Small, Kerrin S; Clark, Taane G; Kwiatkowski, Dominic P; Teo, Yik-Ying
2013-06-06
Natural selection is a significant force that shapes the architecture of the human genome and introduces diversity across global populations. The question of whether advantageous mutations have arisen in the human genome as a result of single or multiple mutation events remains unanswered except for the fact that there exist a handful of genes such as those that confer lactase persistence, affect skin pigmentation, or cause sickle cell anemia. We have developed a long-range-haplotype method for identifying genomic signatures of positive selection to complement existing methods, such as the integrated haplotype score (iHS) or cross-population extended haplotype homozygosity (XP-EHH), for locating signals across the entire allele frequency spectrum. Our method also locates the founder haplotypes that carry the advantageous variants and infers their corresponding population frequencies. This presents an opportunity to systematically interrogate the whole human genome whether a selection signal shared across different populations is the consequence of a single mutation process followed subsequently by gene flow between populations or of convergent evolution due to the occurrence of multiple independent mutation events either at the same variant or within the same gene. The application of our method to data from 14 populations across the world revealed that positive-selection events tend to cluster in populations of the same ancestry. Comparing the founder haplotypes for events that are present across different populations revealed that convergent evolution is a rare occurrence and that the majority of shared signals stem from the same evolutionary event. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Denkinger, Judith; Gordillo, Luis; Montero-Serra, Ignasi; Murillo, Juan Carlos; Guevara, Nataly; Hirschfeld, Maximilian; Fietz, Katharina; Rubianes, Francisco; Dan, Michael
2015-11-01
Worldwide, pristine environments are influenced by human societies. In the Galapagos Islands, the endangered, endemic Galapagos sea lion (Zalophus wollebaeki) has formed one of the biggest colonies within the town center of Puerto Baquerizo Moreno. About 8,000 people live there and human wildlife interactions occur daily. With colony counts and direct observations from 2008 to 2012, we analyze cause of death, injuries and disease of urban sea lion colonies at Wreck Bay. Population increase since 2008 can be attributed to an immigration of adult sea lions in 2010, resulting in an increase in the pup and juvenile production in 2011 and 2012. Pup mortality increased drastically to 2009 and again in 2011 and 2012. Besides pup mortality, most of the deaths are caused by increased disease incidences and human activity. Our observations suggest that overall 65% of the injuries observed are produced by human interaction. The increase in threats leading to death, injuries or disease can have long-term effects on the population. Although threats that cause physical injuries can be managed locally, sea lions range movements contributes to the spread of infectious pathogens, which may affect neighbor colonies and potentially have an impact on the survival of the species. Our study reveals the need of stronger efforts towards a more complete understanding of threats and especially disease spread among Galapagos Sea lions in urban environments and the establishment of more effective management measures.
Roger B. Hammer; Susan I. Stewart; Richelle L. Winkler; Volker C. Radeloff; Paul R. Voss
2004-01-01
The spatial deconcentration of population during the 20th century and the resulting expansion of human settlements has been a significant cause of anthropogenic landscape change in the United States and many other countries. In the seven-state North Central Region, as in other regions of the US, changing human settlement patterns are most prominent at the outlying...
Johnson, Eric S; Ndetan, Harrison
2011-02-01
The role of the biological environment in the occurrence of many chronic human diseases has been little studied. Humans are commonly exposed to transmissible agents that infect and cause a wide variety of subacute and chronic diseases in chickens and turkeys. The objective of this study is to investigate whether these agents cause similar diseases in humans, by studying workers in poultry slaughtering and processing plants who have one of the highest human exposures to these agents. Mortality in poultry workers was compared with that in the United States general population through the estimation of standardized mortality ratios. Excess mortality from infectious and parasitic diseases was observed in the poultry workers. In addition, excess occurrences of deaths involving several sites of the cardiovascular, neurological, endocrine, gastrointestinal and reproductive systems, were observed, although the numbers involved were few in some instances. The results indicate that poultry workers are at increased risk of dying from certain causes of death, including infections. This is consistent with other reports. Although it is possible that occupational exposure to transmissible agents present in poultry may be one of the causes of the excess occurrence of some of these diseases, other factors that were not considered because of the nature of the study design, could be equally important. Also, the small number of deaths involved in some instances calls for caution in interpreting the results. However, the study is important, as it has succeeded in newly identified areas that need further research, and which may have implications not only for workers, but also for the general population. Copyright © 2010 Elsevier Ltd. All rights reserved.
Recent advances in understanding the role of nutrition in human genome evolution.
Ye, Kaixiong; Gu, Zhenglong
2011-11-01
Dietary transitions in human history have been suggested to play important roles in the evolution of mankind. Genetic variations caused by adaptation to diet during human evolution could have important health consequences in current society. The advance of sequencing technologies and the rapid accumulation of genome information provide an unprecedented opportunity to comprehensively characterize genetic variations in human populations and unravel the genetic basis of human evolution. Series of selection detection methods, based on various theoretical models and exploiting different aspects of selection signatures, have been developed. Their applications at the species and population levels have respectively led to the identification of human specific selection events that distinguish human from nonhuman primates and local adaptation events that contribute to human diversity. Scrutiny of candidate genes has revealed paradigms of adaptations to specific nutritional components and genome-wide selection scans have verified the prevalence of diet-related selection events and provided many more candidates awaiting further investigation. Understanding the role of diet in human evolution is fundamental for the development of evidence-based, genome-informed nutritional practices in the era of personal genomics.
Epidemiology of the Ebola Virus: Facts and Hypotheses.
Portela Câmara F
1998-12-01
Marburg and Ebola viruses are emerging pathogens recognized since 1967, and in 1976, when they were first identified. These viruses are the only members of the Filoviridae family. They cause severe, frequently fatal, hemorrhagic fever. Each genus includes some serotypes with the distinctive characteristics to cause high mortality rate during outbreaks. The Ebola-Zaire subtype is the most lethal variant. The epidemiology of human pathogenic filovirus is reviewed in this paper considering the most relevant facts. Primary human cases arise probably through close contact with infected primates. This point may be the key to preventing the introduction of these viruses in human populations. Once introduced in humans, the infection may spread through close contact with infected individuals or their body fluids, particularly in hospital environments. A main feature of filovirus outbreaks is the occurrence of cycles of secondary infection.
Human health implications of avian influenza viruses and paramyxoviruses.
Capua, I; Alexander, D J
2004-01-01
Among avian influenza viruses and avian paramyxoviruses are the aetiological agents of two of the most devastating diseases of the animal kingdom: (i). the highly pathogenic form of avian influenza, caused by some viruses of the H5 and H7 subtypes, and (ii). Newcastle disease, caused by virulent strains of APMV type 1. Mortality rates due to these agents can exceed 50% in naïve bird populations, and, for some strains of AI, nearly 100%. These viruses may also be responsible for clinical conditions in humans. The virus responsible for Newcastle disease has been known to cause conjunctivitis in humans since the 1940s. The conjunctivitis is self-limiting and does not have any permanent consequences. Until 1997, reports of human infection with avian influenza viruses were sporadic and frequently associated with conjunctivitis. Recently, however, avian influenza virus infections have been associated with fatalities in human beings. These casualties have highlighted the potential risk that this type of infection poses to public health. In particular, the pathogenetic mechanisms of highly pathogenic avian influenza viruses in birds and the possibility of reassortment between avian and human viruses in the human host represent serious threats to human health. For this reason, any suspected case should be investigated thoroughly.
Adolphe Quetelet: Prophet of the New Statistics,
1980-05-01
study human societies. He ended by insisting that a complete census of the population was necessary. Such a census was decreed in 1828 to take place in...What a sorry state for the human race. The parts played by the prisons, the fetters, the death penalty, seem fixed with as much probability as the...book on probability theory that "frequency regularities" imply "constant causes" in the world of the social side of humanity , and had hinted that a
DOT National Transportation Integrated Search
2015-07-21
Carnivores are particularly sensitive to reductions in population connectivity caused by human disturbance and habitat fragmentation. Permeability of transportation corridors to carnivore movements is central to species conservation given the large s...
Possible mechanisms of mammalian immunocontraception.
Barber, M R; Fayrer-Hosken, R A
2000-03-01
Ecological and conservation programs in ecosystems around the world have experienced varied success in population management. One of the greatest problems is that human expansion has led to the shrinking of wildlife habitat and, as a result, the overpopulation of many different species has occurred. The pressures exerted by the increased number of animals has caused environmental damage. The humane and practical control of these populations has solicited the scientific community to arrive at a safe, effective, and cost-efficient means of population control. Immunocontraception using zona pellucida antigens, specifically porcine zona pellucida (pZP), has become one of the most promising population control tools in the world today, with notable successes in horses and elephants. A conundrum has risen where pZP, a single vaccine, successfully induces an immunocontraceptive effect in multiple species of mammals. This review describes the most current data pertaining to the mammalian zona pellucida and immunocontraception, and from these studies, we suggest several potential mechanisms of immunocontraception.
Winslow, Ksenia; Ho, Andrew; Fortney, Kristen; Morgen, Eric
2017-01-01
Biomarkers of all-cause mortality are of tremendous clinical and research interest. Because of the long potential duration of prospective human lifespan studies, such biomarkers can play a key role in quantifying human aging and quickly evaluating any potential therapies. Decades of research into mortality biomarkers have resulted in numerous associations documented across hundreds of publications. Here, we present MortalityPredictors.org, a manually-curated, publicly accessible database, housing published, statistically-significant relationships between biomarkers and all-cause mortality in population-based or generally healthy samples. To gather the information for this database, we searched PubMed for appropriate research papers and then manually curated relevant data from each paper. We manually curated 1,576 biomarker associations, involving 471 distinct biomarkers. Biomarkers ranged in type from hematologic (red blood cell distribution width) to molecular (DNA methylation changes) to physical (grip strength). Via the web interface, the resulting data can be easily browsed, searched, and downloaded for further analysis. MortalityPredictors.org provides comprehensive results on published biomarkers of human all-cause mortality that can be used to compare biomarkers, facilitate meta-analysis, assist with the experimental design of aging studies, and serve as a central resource for analysis. We hope that it will facilitate future research into human mortality and aging. PMID:28858850
Peto, Maximus V; De la Guardia, Carlos; Winslow, Ksenia; Ho, Andrew; Fortney, Kristen; Morgen, Eric
2017-08-31
Biomarkers of all-cause mortality are of tremendous clinical and research interest. Because of the long potential duration of prospective human lifespan studies, such biomarkers can play a key role in quantifying human aging and quickly evaluating any potential therapies. Decades of research into mortality biomarkers have resulted in numerous associations documented across hundreds of publications. Here, we present MortalityPredictors.org , a manually-curated, publicly accessible database, housing published, statistically-significant relationships between biomarkers and all-cause mortality in population-based or generally healthy samples. To gather the information for this database, we searched PubMed for appropriate research papers and then manually curated relevant data from each paper. We manually curated 1,576 biomarker associations, involving 471 distinct biomarkers. Biomarkers ranged in type from hematologic (red blood cell distribution width) to molecular (DNA methylation changes) to physical (grip strength). Via the web interface, the resulting data can be easily browsed, searched, and downloaded for further analysis. MortalityPredictors.org provides comprehensive results on published biomarkers of human all-cause mortality that can be used to compare biomarkers, facilitate meta-analysis, assist with the experimental design of aging studies, and serve as a central resource for analysis. We hope that it will facilitate future research into human mortality and aging.
Rodrigues Hoffmann, Aline
2017-02-01
Inhabiting a sterile world is no longer an acceptable or desirable concept. Recent studies developed in the microbiome field have unveiled complex microbial populations inhabiting the skin, digestive, respiratory and reproductive tracts. Microbiome studies have opened new venues to explore the human and animal second genome, its functions and its importance in maintaining health. The composition of the skin microbiome varies across different body sites and across individuals, being influenced by different host habits, including for instance age, sex, diet, hygiene and lifestyle. Exposure to a diverse skin microbiome is now considered to be a key component in immune regulation, and imbalances in these microbial populations are being associated with human and animal skin inflammatory disorders. We have learned that in several skin conditions, there is a significant alteration in the diversity and composition of the microbiota colonizing the skin. For instance, in human and animal patients with atopic dermatitis, dysbiosis of the skin microbiota results in lower diversity of microbial populations. Whether these altered microbial populations are the cause or the effect of inflammatory skin conditions seen in humans and animals are still under investigation, but there is no doubt that the microbiome has an important role in maintaining skin health. This review focuses on the most current studies describing the skin microbiome in humans and animals, its role in modulating the immune system, and its association with human and animal skin diseases. © 2017 ESVD and ACVD.
Corona, Erik; Wang, Liuyang; Ko, Dennis; Patel, Chirag J
2018-01-01
Infectious disease has shaped the natural genetic diversity of humans throughout the world. A new approach to capture positive selection driven by pathogens would provide information regarding pathogen exposure in distinct human populations and the constantly evolving arms race between host and disease-causing agents. We created a human pathogen interaction database and used the integrated haplotype score (iHS) to detect recent positive selection in genes that interact with proteins from 26 different pathogens. We used the Human Genome Diversity Panel to identify specific populations harboring pathogen-interacting genes that have undergone positive selection. We found that human genes that interact with 9 pathogen species show evidence of recent positive selection. These pathogens are Yersenia pestis, human immunodeficiency virus (HIV) 1, Zaire ebolavirus, Francisella tularensis, dengue virus, human respiratory syncytial virus, measles virus, Rubella virus, and Bacillus anthracis. For HIV-1, GWAS demonstrate that some naturally selected variants in the host-pathogen protein interaction networks continue to have functional consequences for susceptibility to these pathogens. We show that selected human genes were enriched for HIV susceptibility variants (identified through GWAS), providing further support for the hypothesis that ancient humans were exposed to lentivirus pandemics. Human genes in the Italian, Miao, and Biaka Pygmy populations that interact with Y. pestis show significant signs of selection. These results reveal some of the genetic footprints created by pathogens in the human genome that may have left lasting marks on susceptibility to infectious disease.
Yellowstone bison genetics: let us move forward
Halbert, Natalie D.; Gogan, Peter J.P.; Hedrick, Philip W.; Wahl, Jacquelyn M.; Derr, James N.
2012-01-01
White and Wallen (2012) disagree with the conclusions and suggestions made in our recent assessment of population structure among Yellowstone National Park (YNP) bison based on 46 autosomal microsatellite loci in 661 animals (Halbert et al. 2012). First, they suggest that "the existing genetic substructure (that we observed) was artificially created." Specifically, they suggest that the substructure observed between the northern and central populations is the result of human activities, both historical and recent. In fact, the genetic composition of all known existing bison herds was created by, or has been influenced by, anthropogenic activities, although this obviously does not reduce the value of these herds for genetic conservation (Dratch and Gogan 2010). As perspective, many, if not most, species of conservation concern have been influenced by human actions and as a result currently exist as isolated populations. However, it is quite difficult to distinguish between genetic differences caused by human actions and important ancestral variation contained in separate populations without data from early time periods. Therefore, to not lose genetic variation that may be significant or indicative of important genetic variation, the generally acceptable management approach is to attempt to retain this variation based on the observed population genetic subdivision (Hedrick et al. 1986).
Visscher, Peter M; Goddard, Michael E
2015-01-01
Heritability is a population parameter of importance in evolution, plant and animal breeding, and human medical genetics. It can be estimated using pedigree designs and, more recently, using relationships estimated from markers. We derive the sampling variance of the estimate of heritability for a wide range of experimental designs, assuming that estimation is by maximum likelihood and that the resemblance between relatives is solely due to additive genetic variation. We show that well-known results for balanced designs are special cases of a more general unified framework. For pedigree designs, the sampling variance is inversely proportional to the variance of relationship in the pedigree and it is proportional to 1/N, whereas for population samples it is approximately proportional to 1/N(2), where N is the sample size. Variation in relatedness is a key parameter in the quantification of the sampling variance of heritability. Consequently, the sampling variance is high for populations with large recent effective population size (e.g., humans) because this causes low variation in relationship. However, even using human population samples, low sampling variance is possible with high N. Copyright © 2015 by the Genetics Society of America.
ERIC Educational Resources Information Center
Prandota, Joseph
2011-01-01
"Toxoplasma gondii" is a protozoan parasite that infects about a third of human population. It is generally believed that in immunocompetent hosts, the parasite infection takes usually asymptomatic course and induces self-limiting disease, but in immunocompromised individuals may cause significant morbidity and mortality. "T. gondii" uses sulfated…
Delport, Tiffany C.; Asher, Amy J.; Beaumont, Linda J.; Webster, Koa N.; Harcourt, Robert G.; Power, Michelle L.
2014-01-01
Giardia and Cryptosporidium are amongst the most common protozoan parasites identified as causing enteric disease in pinnipeds. A number of Giardia assemblages and Cryptosporidium species and genotypes are common in humans and terrestrial mammals and have also been identified in marine mammals. To investigate the occurrence of these parasites in an endangered marine mammal, the Australian sea lion (Neophoca cinerea), genomic DNA was extracted from faecal samples collected from wild populations (n = 271) in Southern and Western Australia and three Australian captive populations (n = 19). These were screened using PCR targeting the 18S rRNA of Giardia and Cryptosporidium. Giardia duodenalis was detected in 28 wild sea lions and in seven captive individuals. Successful sequencing of the 18S rRNA gene assigned 27 Giardia isolates to assemblage B and one to assemblage A, both assemblages commonly found in humans. Subsequent screening at the gdh and β-giardin loci resulted in amplification of only one of the 35 18S rRNA positive samples at the β-giardin locus. Sequencing at the β-giardin locus assigned the assemblage B 18S rRNA confirmed isolate to assemblage AI. The geographic distribution of sea lion populations sampled in relation to human settlements indicated that Giardia presence in sea lions was highest in populations less than 25 km from humans. Cryptosporidium was not detected by PCR screening in either wild colonies or captive sea lion populations. These data suggest that the presence of G. duodenalis in the endangered Australian sea lion is likely the result of dispersal from human sources. Multilocus molecular analyses are essential for the determination of G. duodenalis assemblages and subsequent inferences on transmission routes to endangered marine mammal populations. PMID:25426423
Delport, Tiffany C; Asher, Amy J; Beaumont, Linda J; Webster, Koa N; Harcourt, Robert G; Power, Michelle L
2014-12-01
Giardia and Cryptosporidium are amongst the most common protozoan parasites identified as causing enteric disease in pinnipeds. A number of Giardia assemblages and Cryptosporidium species and genotypes are common in humans and terrestrial mammals and have also been identified in marine mammals. To investigate the occurrence of these parasites in an endangered marine mammal, the Australian sea lion (Neophoca cinerea), genomic DNA was extracted from faecal samples collected from wild populations (n = 271) in Southern and Western Australia and three Australian captive populations (n = 19). These were screened using PCR targeting the 18S rRNA of Giardia and Cryptosporidium. Giardia duodenalis was detected in 28 wild sea lions and in seven captive individuals. Successful sequencing of the 18S rRNA gene assigned 27 Giardia isolates to assemblage B and one to assemblage A, both assemblages commonly found in humans. Subsequent screening at the gdh and β-giardin loci resulted in amplification of only one of the 35 18S rRNA positive samples at the β-giardin locus. Sequencing at the β-giardin locus assigned the assemblage B 18S rRNA confirmed isolate to assemblage AI. The geographic distribution of sea lion populations sampled in relation to human settlements indicated that Giardia presence in sea lions was highest in populations less than 25 km from humans. Cryptosporidium was not detected by PCR screening in either wild colonies or captive sea lion populations. These data suggest that the presence of G. duodenalis in the endangered Australian sea lion is likely the result of dispersal from human sources. Multilocus molecular analyses are essential for the determination of G. duodenalis assemblages and subsequent inferences on transmission routes to endangered marine mammal populations.
Palacios, Juan José; Navarro, Yurena; Romero, Beatriz; Penedo, Ana; Menéndez González, Ángela; Pérez Hernández, M Dolores; Fernández-Verdugo, Ana; Copano, Francisca; Torreblanca, Aurora; Bouza, Emilio; Domínguez, Lucas; de Juan, Lucía; García-de-Viedma, Darío
2016-11-15
Human Mycobacterium bovis infections are considered to be due to reactivations, when involve elderly people, or to recent transmissions, when exposure is occupational. We determined the cause of M. bovis infections by genotyping M. bovis isolates in a population-based study integrating human and animal databases. Among the 1,586 tuberculosis (TB) cases in Asturias, Northern Spain (1,080,000 inhabitants), 1,567 corresponded to M. tuberculosis and 19 to M. bovis. The number of human isolates sharing genotype with cattle isolates was higher than expected (47%) for a setting with low prevalence of bovine TB and efficient control programs in cattle. The risk of exposure to infected animals was probable/possible in most of these matched cases (77.7%). Recent transmission was the likely explanation of most M. bovis infections in elderly people. A potential human-to-human transmission was found. Our study illustrates a model of collaboration between human and animal health professionals to provide a precise snapshot of the transmission of M. bovis in the human-animal interface. Copyright © 2016 Elsevier B.V. All rights reserved.
Carvalho, Chris; Yang, Jiaqi; Vogan, Aaron; Maganti, Harinad; Yamamura, Deborah; Xu, Jianping
2014-05-01
Yeast are among the most frequent pathogens in humans. The dominant yeast causing human infections belong to the genus Candida and Candida albicans is the most frequently isolated species. However, several non-C. albicans species are becoming increasingly common in patients worldwide. The relationships between yeast in humans and the natural environments remain poorly understood. Furthermore, it is often difficult to identify or exclude the origins of disease-causing yeast from specific environmental reservoirs. In this study, we compared the yeast isolates from tree hollows and from clinics in Hamilton, Ontario, Canada. Our surveys and analyses showed significant differences in yeast species composition, in their temporal dynamics, and in yeast genotypes between isolates from tree hollows and hospitals. Our results are inconsistent with the hypothesis that yeast from trees constitute a significant source of pathogenic yeast in humans in this region. Similarly, the yeast in humans and clinics do not appear to contribute to yeast in tree hollows. © 2013 Blackwell Verlag GmbH.
Therapeutic and prophylactic drugs to treat orthopoxvirus infections.
Parker, Scott; Handley, Lauren; Buller, R Mark
2008-11-01
With the global eradication of smallpox in 1979, the causative agent, variola, no longer circulates in human populations. Other human poxvirus infections, such as those caused by vaccinia, cowpox virus and molluscum, are usually relatively benign in immunocompetent individuals. Conversely, monkeypox virus infections cause high levels of mortality and morbidity in Africa and the virus appears to be increasing its host range, virulence and demographic environs. Furthermore, there are concerns that clandestine stocks of variola virus exist. The re-introduction of aerosolized variola (or perhaps monkeypox virus) into human populations would result in high levels of morbidity and mortality. The attractiveness of variola as a bioweapon and, to a certain extent, monkeypox virus is its inherent ability to spread from person-to-person. The threat posed by the intentional release of variola or monkeypox virus, or a monkeypox virus epizoonosis, will require the capacity to rapidly diagnose the disease and to intervene with antivirals, as intervention is likely to take place during the initial diagnosis, approximately 10-15 days postinfection. Preimmunization of 'at-risk populations' with vaccines will likely not be practical, and the therapeutic use of vaccines has been shown to be ineffective after 4 days of infection with variola. However, a combination of vaccine and antivirals for those infected may be an option. Here we describe historical, current and future therapies to treat orthopoxvirus diseases.
Kazacos, Kevin R.; Abbott, Rachel C.; van Riper, Charles
2016-05-26
SummaryBaylisascaris procyonis, the common raccoon roundworm, is the most commonly recognized cause of clinical larva migrans (LM) in animals, a condition in which an immature parasitic worm or larva migrates in a host animal’s tissues, causing obvious disease. Infection with B. procyonis is best known as a cause of fatal or severe neurologic disease that results when the larvae invade the brain, the spinal cord, or both; this condition is known as neural larva migrans (NLM). Baylisascariasis is a zoonotic disease, that is, one that is transmissible from animals to humans. In humans, B. procyonis can cause damaging visceral (VLM), ocular (OLM), and neural larva migrans. Due to the ubiquity of infected raccoons around humans, there is considerable human exposure and risk of infection with this parasite. The remarkable disease-producing capability of B. procyonis in animals and humans is one of the most significant aspects of the biology of ascarids (large roundworms) to come to light in recent years. Infection with B. procyonis has important health implications for a wide variety of free-ranging and captive wildlife, zoo animals, domestic animals, as well as human beings, on both an individual and population level. This report, eighth in the series of U.S. Geological Survey Circulars on zoonotic diseases, will help us to better understand the routes of Baylisascaris procyonis infections and how best to adequately monitor this zoonotic disease.
Emerging fungal threats to animal, plant and ecosystem health
Fisher, Matthew C.; Henk, Daniel. A.; Briggs, Cheryl J.; Brownstein, John S.; Madoff, Lawrence C.; McCraw, Sarah L.; Gurr, Sarah J.
2013-01-01
The past two decades have seen an increasing number of virulent infectious diseases in natural populations and managed landscapes. In both animals and plants, an unprecedented number of fungal and fungal-like diseases have recently caused some of the most severe die-offs and extinctions ever witnessed in wild species, and are jeopardizing food security. Human activity is intensifying fungal disease dispersal by modifying natural environments and thus creating new opportunities for evolution. We argue that nascent fungal infections will cause increasing attrition of biodiversity, with wider implications for human and ecosystem health, unless steps are taken to tighten biosecurity worldwide. PMID:22498624
Wildlife trade and global disease emergence.
Karesh, William B; Cook, Robert A; Bennett, Elizabeth L; Newcomb, James
2005-07-01
The global trade in wildlife provides disease transmission mechanisms that not only cause human disease outbreaks but also threaten livestock, international trade, rural livelihoods, native wildlife populations, and the health of ecosystems. Outbreaks resulting from wildlife trade have caused hundreds of billions of dollars of economic damage globally. Rather than attempting to eradicate pathogens or the wild species that may harbor them, a practical approach would include decreasing the contact rate among species, including humans, at the interface created by the wildlife trade. Since wildlife marketing functions as a system of scale-free networks with major hubs, these points provide control opportunities to maximize the effects of regulatory efforts.
Global rates of habitat loss and implications for amphibian conservation
Gallant, Alisa L.; Klaver, R.W.; Casper, G.S.; Lannoo, M.J.
2007-01-01
A large number of factors are known to affect amphibian population viability, but most authors agree that the principal causes of amphibian declines are habitat loss, alteration, and fragmentation. We provide a global assessment of land use dynamics in the context of amphibian distributions. We accomplished this by compiling global maps of amphibian species richness and recent rates of change in land cover, land use, and human population growth. The amphibian map was developed using a combination of published literature and digital databases. We used an ecoregion framework to help interpret species distributions across environmental, rather than political, boundaries. We mapped rates of land cover and use change with statistics from the World Resources Institute, refined with a global digital dataset on land cover derived from satellite data. Temporal maps of human population were developed from the World Resources Institute database and other published sources. Our resultant map of amphibian species richness illustrates that amphibians are distributed in an uneven pattern around the globe, preferring terrestrial and freshwater habitats in ecoregions that are warm and moist. Spatiotemporal patterns of human population show that, prior to the 20th century, population growth and spread was slower, most extensive in the temperate ecoregions, and largely exclusive of major regions of high amphibian richness. Since the beginning of the 20th century, human population growth has been exponential and has occurred largely in the subtropical and tropical ecoregions favored by amphibians. Population growth has been accompanied by broad-scale changes in land cover and land use, typically in support of agriculture. We merged information on land cover, land use, and human population growth to generate a composite map showing the rates at which humans have been changing the world. When compared with the map of amphibian species richness, we found that many of the regions of the earth supporting the richest assemblages of amphibians are currently undergoing the highest rates of landscape modification.
Wu, Qizhu; Yin, Ye; Zhou, Huanmin
2014-01-01
Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]–1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. PMID:25377941
Hahn, Micah B.; Gurley, Emily S.; Epstein, Jonathan H.; Islam, Mohammad S.; Patz, Jonathan A.; Daszak, Peter; Luby, Stephen P.
2014-01-01
Nipah virus has caused recurring outbreaks in central and northwest Bangladesh (the “Nipah Belt”). Little is known about roosting behavior of the fruit bat reservoir, Pteropus giganteus, or factors driving spillover. We compared human population density and ecological characteristics of case villages and control villages (no reported outbreaks) to understand their role in P. giganteus roosting ecology and Nipah virus spillover risk. Nipah Belt villages have a higher human population density (P < 0.0001), and forests that are more fragmented than elsewhere in Bangladesh (0.50 versus 0.32 patches/km2, P < 0.0001). The number of roosts in a village correlates with forest fragmentation (r = 0.22, P = 0.03). Villages with a roost containing Polyalthia longifolia or Bombax ceiba trees were more likely case villages (odds ratio [OR] = 10.8, 95% confidence interval [CI] = 1.3–90.6). This study suggests that, in addition to human population density, composition and structure of the landscape shared by P. giganteus and humans may influence the geographic distribution of Nipah virus spillovers. PMID:24323516
Hahn, Micah B; Gurley, Emily S; Epstein, Jonathan H; Islam, Mohammad S; Patz, Jonathan A; Daszak, Peter; Luby, Stephen P
2014-02-01
Nipah virus has caused recurring outbreaks in central and northwest Bangladesh (the "Nipah Belt"). Little is known about roosting behavior of the fruit bat reservoir, Pteropus giganteus, or factors driving spillover. We compared human population density and ecological characteristics of case villages and control villages (no reported outbreaks) to understand their role in P. giganteus roosting ecology and Nipah virus spillover risk. Nipah Belt villages have a higher human population density (P < 0.0001), and forests that are more fragmented than elsewhere in Bangladesh (0.50 versus 0.32 patches/km(2), P < 0.0001). The number of roosts in a village correlates with forest fragmentation (r = 0.22, P = 0.03). Villages with a roost containing Polyalthia longifolia or Bombax ceiba trees were more likely case villages (odds ratio [OR] = 10.8, 95% confidence interval [CI] = 1.3-90.6). This study suggests that, in addition to human population density, composition and structure of the landscape shared by P. giganteus and humans may influence the geographic distribution of Nipah virus spillovers.
Bolund, Elisabeth; Lummaa, Virpi; Smith, Ken R.; Hanson, Heidi A.; Maklakov, Alexei A.
2016-01-01
The causes underlying sex differences in lifespan are strongly debated. While females commonly outlive males in humans, this is generally less pronounced in societies before the demographic transition to low mortality and fertility rates. Life-history theory suggests that reduced reproduction should benefit female lifespan when females pay higher costs of reproduction than males. Using unique longitudinal demographic records on 140,600 reproducing individuals from the Utah Population Database, we demonstrate a shift from male-biased to female-biased adult lifespans in individuals born before versus during the demographic transition. Only women paid a cost of reproduction in terms of shortened post-reproductive lifespan at high parities. Therefore, as fertility decreased over time, female lifespan increased, while male lifespan remained largely stable, supporting the theory that differential costs of reproduction in the two sexes result in the shifting patterns of sex differences in lifespan across human populations. Further, our results have important implications for demographic forecasts in human populations and advance our understanding of lifespan evolution. PMID:27087670
Pybus, Marc; Andrews, Glen K.; Lalueza-Fox, Carles; Comas, David; Sekler, Israel; de la Rasilla, Marco; Rosas, Antonio; Stoneking, Mark; Valverde, Miguel A.; Vicente, Rubén; Bosch, Elena
2014-01-01
Extreme differences in allele frequency between West Africans and Eurasians were observed for a leucine-to-valine substitution (Leu372Val) in the human intestinal zinc uptake transporter, ZIP4, yet no further evidence was found for a selective sweep around the ZIP4 gene (SLC39A4). By interrogating allele frequencies in more than 100 diverse human populations and resequencing Neanderthal DNA, we confirmed the ancestral state of this locus and found a strong geographical gradient for the derived allele (Val372), with near fixation in West Africa. In extensive coalescent simulations, we show that the extreme differences in allele frequency, yet absence of a classical sweep signature, can be explained by the effect of a local recombination hotspot, together with directional selection favoring the Val372 allele in Sub-Saharan Africans. The possible functional effect of the Leu372Val substitution, together with two pathological mutations at the same codon (Leu372Pro and Leu372Arg) that cause acrodermatitis enteropathica (a disease phenotype characterized by extreme zinc deficiency), was investigated by transient overexpression of human ZIP4 protein in HeLa cells. Both acrodermatitis mutations cause absence of the ZIP4 transporter cell surface expression and nearly absent zinc uptake, while the Val372 variant displayed significantly reduced surface protein expression, reduced basal levels of intracellular zinc, and reduced zinc uptake in comparison with the Leu372 variant. We speculate that reduced zinc uptake by the ZIP4-derived Val372 isoform may act by starving certain pathogens of zinc, and hence may have been advantageous in Sub-Saharan Africa. Moreover, these functional results may indicate differences in zinc homeostasis among modern human populations with possible relevance for disease risk. PMID:24586184
Immune Function and Reactivation of Latent Viruses
NASA Technical Reports Server (NTRS)
Butel, Janet S.
1999-01-01
A major concern associated with long-duration space flight is the possibility of infectious diseases posing an unacceptable medical risk to crew members. One major hypothesis addressed in this project is that space flight will cause alterations in the immune system that will allow latent viruses that are endogenous in the human population to reactivate and shed to higher levels than normal, which may affect the health of crew members. The second major hypothesis being examined is that the effects of space flight will alter the mucosal immune system, the first line of defense against many microbial infections, including herpesviruses, polyomaviruses, and gastroenteritis viruses, rendering crew members more susceptible to virus infections across the mucosa. We are focusing the virus studies on the human herpesviruses and polyomaviruses, important pathogens known to establish latent infections in most of the human population. Both primary infection and reactivation from latent infection with these groups of viruses (especially certain herpesviruses) can cause a variety of illnesses that result in morbidity and, occasionally, mortality. Both herpesviruses and polyomaviruses have been associated with human cancer, as well. Effective vaccines exist for only one of the eight known human herpesviruses and available antivirals are of limited use. Whereas normal individuals display minimal consequences from latent viral infections, events which alter immune function (such as immunosuppressive therapy following solid organ transplantation) are known to increase the risk of complications as a result of viral reactivations.
THE RELATIONSHIP OF URBAN DESIGN TO HUMAN HEALTH AND CONDITION
The population of the United States of American is currently experiencing increased illness from dispersed and synergistic causes. Many of the acute insults of the past have receded due to centralized health care and regulatory action. However, chronic ailments including asthma...
Nonlinear dynamics of avian influenza epidemic models.
Liu, Sanhong; Ruan, Shigui; Zhang, Xinan
2017-01-01
Avian influenza is a zoonotic disease caused by the transmission of the avian influenza A virus, such as H5N1 and H7N9, from birds to humans. The avian influenza A H5N1 virus has caused more than 500 human infections worldwide with nearly a 60% death rate since it was first reported in Hong Kong in 1997. The four outbreaks of the avian influenza A H7N9 in China from March 2013 to June 2016 have resulted in 580 human cases including 202 deaths with a death rate of nearly 35%. In this paper, we construct two avian influenza bird-to-human transmission models with different growth laws of the avian population, one with logistic growth and the other with Allee effect, and analyze their dynamical behavior. We obtain a threshold value for the prevalence of avian influenza and investigate the local or global asymptotical stability of each equilibrium of these systems by using linear analysis technique or combining Liapunov function method and LaSalle's invariance principle, respectively. Moreover, we give necessary and sufficient conditions for the occurrence of periodic solutions in the avian influenza system with Allee effect of the avian population. Numerical simulations are also presented to illustrate the theoretical results. Copyright © 2016 Elsevier Inc. All rights reserved.
Templeton, A R; Robertson, R J; Brisson, J; Strasburg, J
2001-05-08
Humans affect biodiversity at the genetic, species, community, and ecosystem levels. This impact on genetic diversity is critical, because genetic diversity is the raw material of evolutionary change, including adaptation and speciation. Two forces affecting genetic variation are genetic drift (which decreases genetic variation within but increases genetic differentiation among local populations) and gene flow (which increases variation within but decreases differentiation among local populations). Humans activities often augment drift and diminish gene flow for many species, which reduces genetic variation in local populations and prevents the spread of adaptive complexes outside their population of origin, thereby disrupting adaptive processes both locally and globally within a species. These impacts are illustrated with collared lizards (Crotaphytus collaris) in the Missouri Ozarks. Forest fire suppression has reduced habitat and disrupted gene flow in this lizard, thereby altering the balance toward drift and away from gene flow. This balance can be restored by managed landscape burns. Some have argued that, although human-induced fragmentation disrupts adaptation, it will also ultimately produce new species through founder effects. However, population genetic theory and experiments predict that most fragmentation events caused by human activities will facilitate not speciation, but local extinction. Founder events have played an important role in the macroevolution of certain groups, but only when ecological opportunities are expanding rather than contracting. The general impact of human activities on genetic diversity disrupts or diminishes the capacity for adaptation, speciation, and macroevolutionary change. This impact will ultimately diminish biodiversity at all levels.
Zedrosser, Andreas; Pelletier, Fanie; Bischof, Richard; Festa-Bianchet, Marco; Swenson, Jon E
2013-01-01
In iteroparous mammals, conditions experienced early in life may have long-lasting effects on lifetime reproductive success. Human-induced mortality is also an important demographic factor in many populations of large mammals and may influence lifetime reproductive success. Here, we explore the effects of early development, population density, and human hunting on survival and lifetime reproductive success in brown bear (Ursus arctos) females, using a 25-year database of individually marked bears in two populations in Sweden. Survival of yearlings to 2 years was not affected by population density or body mass. Yearlings that remained with their mother had higher survival than independent yearlings, partly because regulations prohibit the harvest of bears in family groups. Although mass as a yearling did not affect juvenile survival, it was positively associated with measures of lifetime reproductive success and individual fitness. The majority of adult female brown bear mortality (72%) in our study was due to human causes, mainly hunting, and many females were killed before they reproduced. Therefore, factors allowing females to survive several hunting seasons had a strong positive effect on lifetime reproductive success. We suggest that, in many hunted populations of large mammals, sport harvest is an important influence on both population dynamics and life histories.
Ginsberg, H.
1994-01-01
Lyme disease is a tick-borne illness that is wide-spread in North America, especially in the northeastern and northcentral United States. This disease could negatively influence efforts to conserve natural populations in two ways: (1) the disease could directly affect wild animal health; and (2) tick control efforts could adversely affect natural populations and communities. Lyme disease affects several domestic animals, but symptoms have been reported in only a few wild species. Direct effects of Lyme disease on wild animal populations have not been reported, but the disease should be considered as a possible cause in cases of unexplained population declines in endemic areas. Methods available to manage ticks and Lyme disease include human self-protection techniques, manipulation of habitats and hosts species populations, biological control, and pesticide applications. The diversity of available techniques allows selection of approaches to minimize environmental effects by (1) emphasizing personal protection techniques, (2) carefully targeting management efforts to maximize efficiency, and (3) integrating environmentally benign techniques to improve management while avoiding broad-scale environmentally destructive approaches. The environmental effects of Lyme disease depend, to a large extent, on the methods chosen to minimize human exposure to infected ticks. Conservation biologists can help design tick management programs that effectively lower the incidence of human Lyme disease while simultaneously minimizing negative effects on natural populations.
An Upper Limit on the Functional Fraction of the Human Genome.
Graur, Dan
2017-07-01
For the human population to maintain a constant size from generation to generation, an increase in fertility must compensate for the reduction in the mean fitness of the population caused, among others, by deleterious mutations. The required increase in fertility due to this mutational load depends on the number of sites in the genome that are functional, the mutation rate, and the fraction of deleterious mutations among all mutations in functional regions. These dependencies and the fact that there exists a maximum tolerable replacement level fertility can be used to put an upper limit on the fraction of the human genome that can be functional. Mutational load considerations lead to the conclusion that the functional fraction within the human genome cannot exceed 25%, and is probably considerably lower. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
The emergence of human-evolutionary medical genomics
Crespi, Bernard J
2011-01-01
In this review, I describe how evolutionary genomics is uniquely suited to spearhead advances in understanding human disease risk, owing to the privileged position of genes as fundamental causes of phenotypic variation, and the ability of population genetic and phylogenetic methods to robustly infer processes of natural selection, drift, and mutation from genetic variation at the levels of family, population, species, and clade. I first provide an overview of models for the origins and maintenance of genetically based disease risk in humans. I then discuss how analyses of genetic disease risk can be dovetailed with studies of positive and balancing selection, to evaluate the degree to which the ‘genes that make us human’ also represent the genes that mediate risk of polygenic disease. Finally, I present four basic principles for the nascent field of human evolutionary medical genomics, each of which represents a process that is nonintuitive from a proximate perspective. Joint consideration of these principles compels novel forms of interdisciplinary analyses, most notably studies that (i) analyze tradeoffs at the level of molecular genetics, and (ii) identify genetic variants that are derived in the human lineage or in specific populations, and then compare individuals with derived versus ancestral alleles. PMID:25567974
Doocy, Shannon; Daniels, Amy; Murray, Sarah; Kirsch, Thomas D
2013-04-16
Background. Floods are the most common natural disaster and the leading cause of natural disaster fatalities worldwide. Risk of catastrophic losses due to flooding is significant given deforestation and the increasing proximity of large populations to coastal areas, river basins and lakeshores. The objectives of this review were to describe the impact of flood events on human populations in terms of mortality, injury, and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters Methods. Data on the impact of floods were compiled using two methods, a historical review of flood events from 1980 to 2009 from multiple databases and a systematic literature review of publications ending in October 2012. Analysis included descriptive statistics, bivariate tests for associations and multinomial logistic regression of flood characteristics and mortality using Stata 11.0. Findings. There were 539,811 deaths (range: 510,941 to 568,680), 361,974 injuries and 2,821,895,005 people affected by floods between 1980 and 2009. Inconsistent reporting suggests this is an underestimate, particularly in terms of the injured and affected populations. The primary cause of flood-related mortality is drowning; in developed countries being in a motor-vehicle and male gender are associated with increased mortality, whereas female gender may be linked to higher mortality in low-income countries. Conclusions. Expanded monitoring of floods, improved mitigation measures, and effective communication with civil authorities and vulnerable populations has the potential to reduce loss of life in future flood events.
The Human Impact of Floods: a Historical Review of Events 1980-2009 and Systematic Literature Review
Doocy, Shannon; Daniels, Amy; Murray, Sarah; Kirsch, Thomas D.
2013-01-01
Background. Floods are the most common natural disaster and the leading cause of natural disaster fatalities worldwide. Risk of catastrophic losses due to flooding is significant given deforestation and the increasing proximity of large populations to coastal areas, river basins and lakeshores. The objectives of this review were to describe the impact of flood events on human populations in terms of mortality, injury, and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters Methods. Data on the impact of floods were compiled using two methods, a historical review of flood events from 1980 to 2009 from multiple databases and a systematic literature review of publications ending in October 2012. Analysis included descriptive statistics, bivariate tests for associations and multinomial logistic regression of flood characteristics and mortality using Stata 11.0. Findings. There were 539,811 deaths (range: 510,941 to 568,680), 361,974 injuries and 2,821,895,005 people affected by floods between 1980 and 2009. Inconsistent reporting suggests this is an underestimate, particularly in terms of the injured and affected populations. The primary cause of flood-related mortality is drowning; in developed countries being in a motor-vehicle and male gender are associated with increased mortality, whereas female gender may be linked to higher mortality in low-income countries. Conclusions. Expanded monitoring of floods, improved mitigation measures, and effective communication with civil authorities and vulnerable populations has the potential to reduce loss of life in future flood events. PMID:23857425
Characterization of Legionella Species from Watersheds in British Columbia, Canada
Peabody, Michael A.; Caravas, Jason A.; Morrison, Shatavia S.; Mercante, Jeffrey W.; Prystajecky, Natalie A.; Raphael, Brian H.
2017-01-01
ABSTRACT Legionella spp. present in some human-made water systems can cause Legionnaires’ disease in susceptible individuals. Although legionellae have been isolated from the natural environment, variations in the organism’s abundance over time and its relationship to aquatic microbiota are poorly understood. Here, we investigated the presence and diversity of legionellae through 16S rRNA gene amplicon and metagenomic sequencing of DNA from isolates collected from seven sites in three watersheds with varied land uses over a period of 1 year. Legionella spp. were found in all watersheds and sampling sites, comprising up to 2.1% of the bacterial community composition. The relative abundance of Legionella tended to be higher in pristine sites than in sites affected by agricultural activity. The relative abundance levels of Amoebozoa, some of which are natural hosts of legionellae, were similarly higher in pristine sites. Compared to other bacterial genera detected, Legionella had both the highest richness and highest alpha diversity. Our findings indicate that a highly diverse population of legionellae may be found in a variety of natural aquatic sources. Further characterization of these diverse natural populations of Legionella will help inform prevention and control efforts aimed at reducing the risk of Legionella colonization of built environments, which could ultimately decrease the risk of human disease. IMPORTANCE Many species of Legionella can cause Legionnaires’ disease, a significant cause of bacterial pneumonia. Legionella in human-made water systems such as cooling towers and building plumbing systems are the primary sources of Legionnaires’ disease outbreaks. In this temporal study of natural aquatic environments, Legionella relative abundance was shown to vary in watersheds associated with different land uses. Analysis of the Legionella sequences detected at these sites revealed highly diverse populations that included potentially novel Legionella species. These findings have important implications for understanding the ecology of Legionella and control measures for this pathogen that are aimed at reducing human disease. PMID:28776042
Red Wolf (Canis rufus) Recovery: A Review with Suggestions for Future Research
Hinton, Joseph W.; Chamberlain, Michael J.; Rabon, David R.
2013-01-01
Simple Summary Once widespread in the Eastern United States, early 20th century predator-control programs reduced red wolves to a remnant population by the 1970s. The U.S. Fish and Wildlife Service, through the Red Wolf Recovery Program, restored red wolves to northeastern North Carolina in 1987. After 25 years of restoration efforts, issues of hybridization with coyotes, inbreeding, and human-caused mortality continue to hamper red wolf recovery. To understand how these issues influence recovery efforts, we examine the history of red wolf restoration and its challenges. We then formulate areas of research that are of direct relevance to the restoration of red wolves. Abstract By the 1970s, government-supported eradication campaigns reduced red wolves to a remnant population of less than 100 individuals on the southern border of Texas and Louisiana. Restoration efforts in the region were deemed unpromising because of predator-control programs and hybridization with coyotes. The U.S. Fish and Wildlife Service (USFWS) removed the last remaining red wolves from the wild and placed them in a captive-breeding program. In 1980, the USFWS declared red wolves extinct in the wild. During 1987, the USFWS, through the Red Wolf Recovery Program, reintroduced red wolves into northeastern North Carolina. Although restoration efforts have established a population of approximately 70–80 red wolves in the wild, issues of hybridization with coyotes, inbreeding, and human-caused mortality continue to hamper red wolf recovery. We explore these three challenges and, within each challenge, we illustrate how research can be used to resolve problems associated with red wolf-coyote interactions, effects of inbreeding, and demographic responses to human-caused mortality. We hope this illustrates the utility of research to advance restoration of red wolves. PMID:26479530
The pandemic potential of avian influenza A(H7N9) virus: a review.
Tanner, W D; Toth, D J A; Gundlapalli, A V
2015-12-01
In March 2013 the first cases of human avian influenza A(H7N9) were reported to the World Health Organization. Since that time, over 650 cases have been reported. Infections are associated with considerable morbidity and mortality, particularly within certain demographic groups. This rapid increase in cases over a brief time period is alarming and has raised concerns about the pandemic potential of the H7N9 virus. Three major factors influence the pandemic potential of an influenza virus: (1) its ability to cause human disease, (2) the immunity of the population to the virus, and (3) the transmission potential of the virus. This paper reviews what is currently known about each of these factors with respect to avian influenza A(H7N9). Currently, sustained human-to-human transmission of H7N9 has not been reported; however, population immunity to the virus is considered very low, and the virus has significant ability to cause human disease. Several statistical and geographical modelling studies have estimated and predicted the spread of the H7N9 virus in humans and avian species, and some have identified potential risk factors associated with disease transmission. Additionally, assessment tools have been developed to evaluate the pandemic potential of H7N9 and other influenza viruses. These tools could also hypothetically be used to monitor changes in the pandemic potential of a particular virus over time.
A review of the health impacts of barium from natural and anthropogenic exposure.
Kravchenko, Julia; Darrah, Thomas H; Miller, Richard K; Lyerly, H Kim; Vengosh, Avner
2014-08-01
There is an increasing public awareness of the relatively new and expanded industrial barium uses which are potential sources of human exposure (e.g., a shale gas development that causes an increased awareness of environmental exposures to barium). However, absorption of barium in exposed humans and a full spectrum of its health effects, especially among chronically exposed to moderate and low doses of barium populations, remain unclear. We suggest a systematic literature review (from 1875 to 2014) on environmental distribution of barium, its bioaccumulation, and potential and proven health impacts (in animal models and humans) to provide the information that can be used for optimization of future experimental and epidemiological studies and developing of mitigative and preventive strategies to minimize negative health effects in exposed populations. The potential health effects of barium exposure are largely based on animal studies, while epidemiological data for humans, specifically for chronic low-level exposures, are sparse. The reported health effects include cardiovascular and kidney diseases, metabolic, neurological, and mental disorders. Age, race, dietary patterns, behavioral risks (e.g., smoking), use of medications (those that interfere with absorbed barium in human organism), and specific physiological status (e.g., pregnancy) can modify barium effects on human health. Identifying, evaluating, and predicting the health effects of chronic low-level and moderate-level barium exposures in humans is challenging: Future research is needed to develop an understanding of barium bioaccumulation in order to mitigate its potential health impacts in various exposured populations. Further, while occupationally exposed at-risk populations exist, it is also important to identify potentially vulnerable subgroups among non-occupationally exposed populations (e.g., elderly, pregnant women, children) who are at higher risk of barium exposure from drinking water and food.
Jaleta, Tegegn G; Zhou, Siyu; Bemm, Felix M; Schär, Fabian; Khieu, Virak; Muth, Sinuon; Odermatt, Peter; Lok, James B; Streit, Adrian
2017-08-01
Strongyloidiasis is a much-neglected soil born helminthiasis caused by the nematode Strongyloides stercoralis. Human derived S. stercoralis can be maintained in dogs in the laboratory and this parasite has been reported to also occur in dogs in the wild. Some authors have considered strongyloidiasis a zoonotic disease while others have argued that the two hosts carry host specialized populations of S. stercoralis and that dogs play a minor role, if any, as a reservoir for zoonotic S. stercoralis infections of humans. We isolated S. stercoralis from humans and their dogs in rural villages in northern Cambodia, a region with a high incidence of strongyloidiasis, and compared the worms derived from these two host species using nuclear and mitochondrial DNA sequence polymorphisms. We found that in dogs there exist two populations of S. stercoralis, which are clearly separated from each other genetically based on the nuclear 18S rDNA, the mitochondrial cox1 locus and whole genome sequence. One population, to which the majority of the worms belong, appears to be restricted to dogs. The other population is indistinguishable from the population of S. stercoralis isolated from humans. Consistent with earlier studies, we found multiple sequence variants of the hypervariable region I of the 18 S rDNA in S. stercoralis from humans. However, comparison of mitochondrial sequences and whole genome analysis suggest that these different 18S variants do not represent multiple genetically isolated subpopulations among the worms isolated from humans. We also investigated the mode of reproduction of the free-living generations of laboratory and wild isolates of S. stercoralis. Contrary to earlier literature on S. stercoralis but similar to other species of Strongyloides, we found clear evidence of sexual reproduction. Overall, our results show that dogs carry two populations, possibly different species of Strongyloides. One population appears to be dog specific but the other one is shared with humans. This argues for the strong potential of dogs as reservoirs for zoonotic transmission of S. stercoralis to humans and suggests that in order to reduce the exposure of humans to infective S. stercoralis larvae, dogs should be treated for the infection along with their owners.
Population dynamics coded in DNA: genetic traces of the expansion of modern humans
NASA Astrophysics Data System (ADS)
Kimmel, Marek
1999-12-01
It has been proposed that modern humans evolved from a small ancestral population, which appeared several hundred thousand years ago in Africa. Descendants of the founder group migrated to Europe and then to Asia, not mixing with the pre-existing local populations but replacing them. Two demographic elements are present in this “out of Africa” hypothesis: numerical growth of the modern humans and their migration into Eurasia. Did these processes leave an imprint in our DNA? To address this question, we use the classical Fisher-Wright-Moran model of population genetics, assuming variable population size and two models of mutation: the infinite-sites model and the stepwise-mutation model. We use the coalescence theory, which amounts to tracing the common ancestors of contemporary genes. We obtain mathematical formulae expressing the distribution of alleles given the time changes of population size . In the framework of the infinite-sites model, simulations indicate that the pattern of past population size change leaves its signature on the pattern of DNA polymorphism. Application of the theory to the published mitochondrial DNA sequences indicates that the current mitochondrial DNA sequence variation is not inconsistent with the logistic growth of the modern human population. In the framework of the stepwise-mutation model, we demonstrate that population bottleneck followed by growth in size causes an imbalance between allele-size variance and heterozygosity. We analyze a set of data on tetranucleotide repeats which reveals the existence of this imbalance. The pattern of imbalance is consistent with the bottleneck being most ancient in Africans, most recent in Asians and intermediate in Europeans. These findings are consistent with the “out of Africa” hypothesis, although by no means do they constitute its proof.
Plague: A Disease Which Changed the Path of Human Civilization.
Bramanti, Barbara; Stenseth, Nils Chr; Walløe, Lars; Lei, Xu
2016-01-01
Plague caused by Yersinia pestis is a zoonotic infection, i.e., it is maintained in wildlife by animal reservoirs and on occasion spills over into human populations, causing outbreaks of different entities. Large epidemics of plague, which have had significant demographic, social, and economic consequences, have been recorded in Western European historical documents since the sixth century. Plague has remained in Europe for over 1400 years, intermittently disappearing, yet it is not clear if there were reservoirs for Y. pestis in Western Europe or if the pathogen was rather reimported on different occasions from Asian reservoirs by human agency. The latter hypothesis thus far seems to be the most plausible one, as it is sustained by both ecological and climatological evidence, helping to interpret the phylogeny of this bacterium.
A Review of Adverse Effects of Road Traffic Noise on Human Health
NASA Astrophysics Data System (ADS)
Singh, Devi; Kumari, Neeraj; Sharma, Pooja
Noise pollution due to road traffic is a potential threat to human health. Since it is a global hazard, the rapid urbanization and exponential traffic growth have aggravated the problem. Population residing along the busy traffic lanes is continuously exposed to the sound levels which are above the permissible limits. This constant exposure to noise pollution is a cause of concern as it leads to several adverse impacts on human health. Traffic noise causes irritation and annoyance, sleep disturbances, cardiovascular disease, risk of stroke, diabetes, hypertension and loss of hearing. It results in decreased work performance. The present review highlights the serious health hazards of road traffic noise (RTN) which needs to be curbed. Preventive measures of noise pollution can help in combating noise-induced health hazards and increased work performance.
von Cramon-Taubadel, Noreen
2011-01-01
Variation in the masticatory behavior of hunter-gatherer and agricultural populations is hypothesized to be one of the major forces affecting the form of the human mandible. However, this has yet to be analyzed at a global level. Here, the relationship between global mandibular shape variation and subsistence economy is tested, while controlling for the potentially confounding effects of shared population history, geography, and climate. The results demonstrate that the mandible, in contrast to the cranium, significantly reflects subsistence strategy rather than neutral genetic patterns, with hunter-gatherers having consistently longer and narrower mandibles than agriculturalists. These results support notions that a decrease in masticatory stress among agriculturalists causes the mandible to grow and develop differently. This developmental argument also explains why there is often a mismatch between the size of the lower face and the dentition, which, in turn, leads to increased prevalence of dental crowding and malocclusions in modern postindustrial populations. Therefore, these results have important implications for our understanding of human masticatory adaptation. PMID:22106280
Human fatalities from wild elephant attacks--a study of fourteen cases.
Das, Sobhan Kr; Chattopadhyay, Saurabh
2011-05-01
Human-wild elephant conflicts are frequently reported from various parts of the country. Encroaching of animal habitat by human civilization is a primary reason for this. The present study comprises of fourteen autopsy cases conducted at the department of Forensic Medicine, B.S Medical College, Bankura, West Bengal, India over a period of three years. The study attempts to find out the nature of injuries caused by wild elephant attack and the common factors contributing to human-wild elephant conflict so that vulnerable population can be cautioned to avoid conflicts. A distinct seasonal as well as diurnal variation of attack incidences was noted. Attacks were sudden and unprovoked. Killer elephants were wild tuskers in all the cases. Victims were from the low socioeconomic group and the cause of death was due to trampling on the vital organs like chest and head. Copyright © 2011 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
Da Cunha, Violette; Davies, Mark R; Douarre, Pierre-Emmanuel; Rosinski-Chupin, Isabelle; Margarit, Immaculada; Spinali, Sebastien; Perkins, Tim; Lechat, Pierre; Dmytruk, Nicolas; Sauvage, Elisabeth; Ma, Laurence; Romi, Benedetta; Tichit, Magali; Lopez-Sanchez, Maria-José; Descorps-Declere, Stéphane; Souche, Erika; Buchrieser, Carmen; Trieu-Cuot, Patrick; Moszer, Ivan; Clermont, Dominique; Maione, Domenico; Bouchier, Christiane; McMillan, David J; Parkhill, Julian; Telford, John L; Dougan, Gordan; Walker, Mark J; Holden, Matthew T G; Poyart, Claire; Glaser, Philippe
2014-08-04
Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal of the digestive and genitourinary tracts of humans that emerged as the leading cause of bacterial neonatal infections in Europe and North America during the 1960s. Due to the lack of epidemiological and genomic data, the reasons for this emergence are unknown. Here we show by comparative genome analysis and phylogenetic reconstruction of 229 isolates that the rise of human GBS infections corresponds to the selection and worldwide dissemination of only a few clones. The parallel expansion of the clones is preceded by the insertion of integrative and conjugative elements conferring tetracycline resistance (TcR). Thus, we propose that the use of tetracycline from 1948 onwards led in humans to the complete replacement of a diverse GBS population by only few TcR clones particularly well adapted to their host, causing the observed emergence of GBS diseases in neonates.
Detecting and Characterizing Genomic Signatures of Positive Selection in Global Populations
Liu, Xuanyao; Ong, Rick Twee-Hee; Pillai, Esakimuthu Nisha; Elzein, Abier M.; Small, Kerrin S.; Clark, Taane G.; Kwiatkowski, Dominic P.; Teo, Yik-Ying
2013-01-01
Natural selection is a significant force that shapes the architecture of the human genome and introduces diversity across global populations. The question of whether advantageous mutations have arisen in the human genome as a result of single or multiple mutation events remains unanswered except for the fact that there exist a handful of genes such as those that confer lactase persistence, affect skin pigmentation, or cause sickle cell anemia. We have developed a long-range-haplotype method for identifying genomic signatures of positive selection to complement existing methods, such as the integrated haplotype score (iHS) or cross-population extended haplotype homozygosity (XP-EHH), for locating signals across the entire allele frequency spectrum. Our method also locates the founder haplotypes that carry the advantageous variants and infers their corresponding population frequencies. This presents an opportunity to systematically interrogate the whole human genome whether a selection signal shared across different populations is the consequence of a single mutation process followed subsequently by gene flow between populations or of convergent evolution due to the occurrence of multiple independent mutation events either at the same variant or within the same gene. The application of our method to data from 14 populations across the world revealed that positive-selection events tend to cluster in populations of the same ancestry. Comparing the founder haplotypes for events that are present across different populations revealed that convergent evolution is a rare occurrence and that the majority of shared signals stem from the same evolutionary event. PMID:23731540
Relations between nutritional condition and survival of North American elk Cervus elaphus
Bender, L.C.; Cook, J.G.; Cook, R.C.; Hall, P.B.
2008-01-01
We related annual and seasonal survival of four populations of elk Cervus elaphus in the Pacific Northwest, USA, to measures and indices of individual nutritional condition. Among populations, for all mortality (human and non-human causes) sources inclusive, annual survival of adult females was correlated with a rump body condition score (rs = 0.627, P = 0.071), and survival over spring-summer-autumn (SSA) was correlated with mean ingesta-free body fat (IFBF; rs = 0.567, P = 0.088) and rump body condition score (rBCS; rs = 0.615, P = 0.050). For non-human mortality sources only, survival through SSA was correlated with IFBF (rs = 0.567, P = 0.088) and rBCS (rs = 0.615, P = 0.050), and survival over winter was correlated with withers body condition score (rs = 0.677, P = 0.045). For human-caused mortality sources only, survival over SSA was correlated with rBCS (rs = 0.696, P = 0.036) and IFBF (rs = 0.696, P = 0.036). For individuals, logistic analysis found that individual likelihood of dying from all mortality sources inclusive was best predicted (??2 = 8.3, P = 0.004, ?? = -1.24) by longissimus dorsi (loin) muscle thickness, a measure of protein catabolism. For only non-human mortality sources, a model (??2 = 16.1, P = 0.0003) containing both loin muscle thickness (??2 = 5.7, P = 0.017, ??= -1.02) and percent ingesta-free body fat (??2 = 4.9, P = 0.027, ?? = -0.35) best predicted individual susceptibility to mortality. Odds ratios indicated that odds of dying increased approximately 3X for each centimeter of loin muscle catabolized and 1.4X for each percent less body fat. No condition indices at the individual level were related to survival from human-caused mortality sources. Our study populations were characterized by low-marginal condition (i.e. mean ingesta-free body fat levels of 5.9-12.3% for lactating cows in late autumn); this likely increased the prominence of measures of muscle catabolism relative to fat accretion in influencing individual elk survival. Elk populations throughout the Pacific Northwest likely show similar condition levels, and consequently individuals are predisposed to mortality to a much greater degree than under optimal foraging conditions. Management strategies which assume that nutritional condition affects vulnerability only at or near condition levels associated with ecological carrying capacity (i.e. near starvation mortality) may overestimate the impact of proximate mortality factors on adult female elk. ?? Wildlife Biology (2008).
Humphrey, Louise T.; De Groote, Isabelle; Morales, Jacob; Barton, Nick; Collcutt, Simon; Bronk Ramsey, Christopher; Bouzouggar, Abdeljalil
2014-01-01
Dental caries is an infectious disease that causes tooth decay. The high prevalence of dental caries in recent humans is attributed to more frequent consumption of plant foods rich in fermentable carbohydrates in food-producing societies. The transition from hunting and gathering to food production is associated with a change in the composition of the oral microbiota and broadly coincides with the estimated timing of a demographic expansion in Streptococcus mutans, a causative agent of human dental caries. Here we present evidence linking a high prevalence of caries to reliance on highly cariogenic wild plant foods in Pleistocene hunter-gatherers from North Africa, predating other high caries populations and the first signs of food production by several thousand years. Archaeological deposits at Grotte des Pigeons in Morocco document extensive evidence for human occupation during the Middle Stone Age and Later Stone Age (Iberomaurusian), and incorporate numerous human burials representing the earliest known cemetery in the Maghreb. Macrobotanical remains from occupational deposits dated between 15,000 and 13,700 cal B.P. provide evidence for systematic harvesting and processing of edible wild plants, including acorns and pine nuts. Analysis of oral pathology reveals an exceptionally high prevalence of caries (51.2% of teeth in adult dentitions), comparable to modern industrialized populations with a diet high in refined sugars and processed cereals. We infer that increased reliance on wild plants rich in fermentable carbohydrates and changes in food processing caused an early shift toward a disease-associated oral microbiota in this population. PMID:24395774
Status and management of moose in the northeastern United States
Wattles, David W.; DeStefano, Stephen
2011-01-01
Moose (Alces alces) populations have recolonized much of their historic range in the northeastern United States in the past 30 years, with their southern range edge extending to southern New England and northern New York. This southerly expansion occurred when certain other populations in the United States were in decline along the southern range edge, with climate change often cited as a probable cause. The areas that moose have recently occupied in the northeastern United States are some of the most densely human populated in moose range, which has raised concern about human safety and moose-vehicle collisions (MVC). We conducted a literature search about moose in the northeastern United States, and distributed a questionnaire and conducted phone interviews with regional biologists responsible for moose management to determine the status of moose, management activity, and research deficiencies and needs. Moose numbers appear stable throughout much of the region, with slow population growth in northern New York. Management activity ranges from regulated harvest of moose in Maine, New Hampshire, and Vermont, to no active management in southern New England and New York. The combined annual harvest in Maine, New Hampshire, and Vermont is >3,000. MVCs are a widespread regional concern with >1,000 occurring annually involving several human fatalities. Research should address impacts of parasitism by winter tick (Dermacentor albipictus) and brain-worm (Parelaphostrongylus tenuis) on productivity and mortality of moose, influence of climate change on population dynamics and range, and conflicts in areas with high human population density.
Ecology of conflict: marine food supply affects human-wildlife interactions on land.
Artelle, Kyle A; Anderson, Sean C; Reynolds, John D; Cooper, Andrew B; Paquet, Paul C; Darimont, Chris T
2016-05-17
Human-wildlife conflicts impose considerable costs to people and wildlife worldwide. Most research focuses on proximate causes, offering limited generalizable understanding of ultimate drivers. We tested three competing hypotheses (problem individuals, regional population saturation, limited food supply) that relate to underlying processes of human-grizzly bear (Ursus arctos horribilis) conflict, using data from British Columbia, Canada, between 1960-2014. We found most support for the limited food supply hypothesis: in bear populations that feed on spawning salmon (Oncorhynchus spp.), the annual number of bears/km(2) killed due to conflicts with humans increased by an average of 20% (6-32% [95% CI]) for each 50% decrease in annual salmon biomass. Furthermore, we found that across all bear populations (with or without access to salmon), 81% of attacks on humans and 82% of conflict kills occurred after the approximate onset of hyperphagia (July 1(st)), a period of intense caloric demand. Contrary to practices by many management agencies, conflict frequency was not reduced by hunting or removal of problem individuals. Our finding that a marine resource affects terrestrial conflict suggests that evidence-based policy for reducing harm to wildlife and humans requires not only insight into ultimate drivers of conflict, but also management that spans ecosystem and jurisdictional boundaries.
POPULATION MONITORING FOR ASSESSMENT OF HEALTH CONCERNS USING BIOMARKERS
Abstract
Exposure to environmental toxic substances is a significant cause of human health problems. In the modern world, exposure to small amount of these substances, either natural or man-made, is often unavoidable. The critical question to ask is, at what concentrations...
Reverse chemical ecology approach for the identification of a mosquito oviposition attractant
USDA-ARS?s Scientific Manuscript database
Pheromones and other semiochemicals play a crucial role in today’s integrated pest and vector management strategies for controlling populations of insects causing loses to agriculture and vectoring diseases to humans. These semiochemicals are typically discovered by bioassay-guided approaches. Here,...
Increasing Prevalence Rate of Nontuberculous Mycobacteria Infections in Five States, 2008–2013
Rationale: Many nontuberculous mycobacteria (NTM) are clinically significant pathogens that cause disease in a variety of different human organs and tissues. Objectives: A population-based study was undertaken to investigate the prevalence of patients with a positive specimen fo...
Prevalence of Cryptosporidium in small ruminants from Veracruz, Mexico
USDA-ARS?s Scientific Manuscript database
Cryptosporidiosis is a zoonotic disease caused by the protozoan parasite Cryptosporidium spp. that can affect domestic animal and human populations. In newborn ruminants, cryptosporidiosis is characterized by outbreaks of diarrhea, which can result in high morbidity and economic impact. The aim of t...
Aeby, Greta S.; Williams, Gareth J.; Franklin, Erik C.; Haapkyla, Jessica; Harvell, C. Drew; Neale, Stephen; Page, Cathie A.; Raymundo, Laurie; Vargas-Angel, Bernardo; Willis, Bette L.; Work, Thierry M.; Davy, Simon K.
2011-01-01
Growth anomalies (GAs) are common, tumor-like diseases that can cause significant morbidity and decreased fecundity in the major Indo-Pacific reef-building coral genera, Acropora and Porites. GAs are unusually tractable for testing hypotheses about drivers of coral disease because of their pan-Pacific distributions, relatively high occurrence, and unambiguous ease of identification. We modeled multiple disease-environment associations that may underlie the prevalence of Acropora growth anomalies (AGA) (n = 304 surveys) and Porites growth anomalies (PGA) (n = 602 surveys) from across the Indo-Pacific. Nine predictor variables were modeled, including coral host abundance, human population size, and sea surface temperature and ultra-violet radiation anomalies. Prevalence of both AGAs and PGAs were strongly host density-dependent. PGAs additionally showed strong positive associations with human population size. Although this association has been widely posited, this is one of the first broad-scale studies unambiguously linking a coral disease with human population size. These results emphasize that individual coral diseases can show relatively distinct patterns of association with environmental predictors, even in similar diseases (growth anomalies) found on different host genera (Acropora vs. Porites). As human densities and environmental degradation increase globally, the prevalence of coral diseases like PGAs could increase accordingly, halted only perhaps by declines in host density below thresholds required for disease establishment.
Franklin, Erik C.; Haapkyla, Jessica; Harvell, C. Drew; Neale, Stephen; Page, Cathie A.; Raymundo, Laurie; Vargas-Ángel, Bernardo; Willis, Bette L.; Work, Thierry M.; Davy, Simon K.
2011-01-01
Growth anomalies (GAs) are common, tumor-like diseases that can cause significant morbidity and decreased fecundity in the major Indo-Pacific reef-building coral genera, Acropora and Porites. GAs are unusually tractable for testing hypotheses about drivers of coral disease because of their pan-Pacific distributions, relatively high occurrence, and unambiguous ease of identification. We modeled multiple disease-environment associations that may underlie the prevalence of Acropora growth anomalies (AGA) (n = 304 surveys) and Porites growth anomalies (PGA) (n = 602 surveys) from across the Indo-Pacific. Nine predictor variables were modeled, including coral host abundance, human population size, and sea surface temperature and ultra-violet radiation anomalies. Prevalence of both AGAs and PGAs were strongly host density-dependent. PGAs additionally showed strong positive associations with human population size. Although this association has been widely posited, this is one of the first broad-scale studies unambiguously linking a coral disease with human population size. These results emphasize that individual coral diseases can show relatively distinct patterns of association with environmental predictors, even in similar diseases (growth anomalies) found on different host genera (Acropora vs. Porites). As human densities and environmental degradation increase globally, the prevalence of coral diseases like PGAs could increase accordingly, halted only perhaps by declines in host density below thresholds required for disease establishment. PMID:21365011
NASA Astrophysics Data System (ADS)
Beckenbauer, Thomas
Road traffic is the most interfering noise source in developed countries. According to a publication of the European Union (EU) at the end of the twentieth century [1], about 40% of the population in 15 EU member states is exposed to road traffic noise at mean levels exceeding 55 dB(A). Nearly 80 million people, 20% of the population, are exposed to levels exceeding 65 dB(A) during daytime and more than 30% of the population is exposed to levels exceeding 55 dB(A) during night time. Such high noise levels cause health risks and social disorders (aggressiveness, protest, and helplessness), interference of communication and disturbance of sleep; the long- and short-term consequences cause adverse cardiovascular effects, detrimental hormonal responses (stress hormones), and possible disturbance of the human metabolism (nutrition) and the immune system. Even performance at work and school could be impaired.
Dereure, J; Rioux, J A; Khiami, A; Pratlong, F; Périères, J; Martini, A
1991-01-01
In an ecoepidemiological study in the Syrian foci of human visceral (VL) and cutaneous (CL) leishmaniasis, domestic dogs infected with Leishmania infantum MON-1 and L. tropica MON-76 were found for the first time. In Syria canine leishmaniasis caused by L. infantum, occurs in the humid and sub-humid western belt from the coastal zone to the nearby mountain ranges. Sporadis cases of human VL occur in this area. Canine CL, caused by L. tropica was found in the semi-arid zone in a village with a high human infection rate. The infection causes small papules or crusted ulcers on the nose or muzzle. These observations are relevant to control. In human VL foci it is recommended not to control the dog population, unless this is linked with other activities, such as rabies control. Control of dogs in the CL areas is not justified because of the small size of the lesions and the rarity of the parasites. Indeed the role of the dog as the "true" reservoir host is questionable. Human CL infection is best controlled by active case detection and specific treatment.
2013-01-01
seeds of chaos. Stability and internal peace bring prosperity; prosperity causes population increase. Demographic growth leads to overpopulation ... overpopulation causes lower wages, higher land rents, and falling per-capita incomes … [Eventually, the] collapse of order brings … famine, war...one of the most innovative, competitive and largest firms in the world (e.g., Investors Business Daily, 2000, 10/31; Bloomberg’s Businessweek, 2001, 9
Mathematical modeling of Avian Influenza epidemic with bird vaccination in constant population
NASA Astrophysics Data System (ADS)
Kharis, M.; Amidi
2018-03-01
The development of the industrial world and human life is increasingly modern and less attention to environmental sustainability causes the virus causes the epidemic has a high tendency to mutate so that the virus that initially only attack animals, is also found to have the ability to attack humans. The epidemics that lasted some time were bird flu epidemics and swine flu epidemics. The flu epidemic led to several deaths and many people admitted to the hospital. Strain (derivatives) of H5N1 virus was identified as the cause of the bird flu epidemic while the H1N1 strain of the virus was identified as the cause of the swine flu epidemic. The symptoms are similar to seasonal flu caused by H3N2 strain of the virus. Outbreaks of bird flu and swine flu initially only attacked animals, but over time some people were found to be infected with the virus.
Can human populations be stabilized?
NASA Astrophysics Data System (ADS)
Warren, Stephen G.
2015-02-01
Historical examples of demographic change, in China, Italy, Nigeria, Utah, Easter Island, and elsewhere, together with simple mathematics and biological principles, show that stabilizing world population before it is limited by food supply will be more difficult than is generally appreciated. United Nations population projections are wrong because they assume, in spite of the absence of necessary feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. Education of women and provision of contraceptives have caused dramatic reductions in fertility, but many groups, including some that are well-educated, maintain high fertility. Small groups with persistent high fertility can grow to supplant low-fertility groups, resulting in continued growth of the total population. The global average fertility rate could rise even if each country's fertility rate is falling. In some low-fertility European countries where deaths exceed births, the population continues to grow because of immigration. Producing more than two offspring is normal for all animal species with stable populations because their populations are limited by resources or predation rather than birth control. It may therefore be appropriate to view the growth of human population as the result not of excess fertility but rather of excess food.
Vioarsdóttir, Una Strand; O'Higgins, Paul; Stringer, Chris
2002-09-01
This study examines interpopulation variations in the facial skeleton of 10 modern human populations and places these in an ontogenetic perspective. It aims to establish the extent to which the distinctive features of adult representatives of these populations are present in the early post natal period and to what extent population differences in ontogenetic scaling and allometric trajectories contribute to distinct facial forms. The analyses utilize configurations of facial landmarks and are carried out using geometric morphometric methods. The results of this study show that modern human populations can be distinguished based on facial shape alone, irrespective of age or sex, indicating the early presence of differences. Additionally, some populations have statistically distinct facial ontogenetic trajectories that lead to the development of further differences later in ontogeny. We conclude that population-specific facial morphologies develop principally through distinctions in facial shape probably already present at birth and further accentuated and modified to variable degrees during growth. These findings raise interesting questions regarding the plasticity of facial growth patterns in modern humans. Further, they have important implications in relation to the study of growth in the face of fossil hominins and in relation to the possibility of developing effective discriminant functions for the identification of population affinities of immature facial skeletal material. Such tools would be of value in archaeological, forensic and anthropological applications. The findings of this study underline the need to examine more deeply, and in more detail, the ontogenetic basis of other causes of craniometric variation, such as sexual dimorphism and hominin species differentiation.
Epilepsy, excess deaths and years of life lost from external causes.
Nevalainen, Olli; Simola, Mikko; Ansakorpi, Hanna; Raitanen, Jani; Artama, Miia; Isojärvi, Jouko; Auvinen, Anssi
2016-05-01
We systematically quantified excess mortality in epilepsy patients by cause of death using the population-attributable fraction and epilepsy-attributable years of potential life lost (YPLL) by age 75 years at ages 15 and over. We updated and undertook a re-review of mortality studies from our previous systematic review following PRISMA guidelines to identify cohort studies of general epilepsy populations reporting a relative risk (RR) of death by cause relative to the background rates in the population. Studies on epilepsy prevalence were identified through published reviews. Country-specific mortality figures were obtained from the WHO World Mortality Database. We performed a pooled analysis with the DerSimonian-Laird random effects method. In countries with very high Human Development Indices, epilepsy contributed to 0.5-1.1 % of all deaths in the total population. Among external causes, suicides (RR 2.9, 95 % confidence interval 2.2-3.8; I(2) 52 %) were the major contributor to YPLL, corresponding to 6.7 % and 4.2 % of excess YPLL due to epilepsy in the United States (US) and in the United Kingdom (UK) in 2010, with 541 (346-792) and 44 (28-65) excess suicide cases, respectively. Fatal accidental falls were more common, with 813 (610-1064) and 95 (71-125) excess deaths in the US and in the UK, but these caused only 2.0 % of excess YPLL as they occurred in older age groups. Suicides were the most important external cause of death in epilepsy patients in terms of excess YPLL, whereas other external causes were either more common in older ages or caused less excess deaths.
Animal Models for the Study of Rodent-Borne Hemorrhagic Fever Viruses: Arenaviruses and Hantaviruses
Golden, Joseph W.; Hammerbeck, Christopher D.; Mucker, Eric M.; Brocato, Rebecca L.
2015-01-01
Human pathogenic hantaviruses and arenaviruses are maintained in nature by persistent infection of rodent carrier populations. Several members of these virus groups can cause significant disease in humans that is generically termed viral hemorrhagic fever (HF) and is characterized as a febrile illness with an increased propensity to cause acute inflammation. Human interaction with rodent carrier populations leads to infection. Arenaviruses are also viewed as potential biological weapons threat agents. There is an increased interest in studying these viruses in animal models to gain a deeper understating not only of viral pathogenesis, but also for the evaluation of medical countermeasures (MCM) to mitigate disease threats. In this review, we examine current knowledge regarding animal models employed in the study of these viruses. We include analysis of infection models in natural reservoirs and also discuss the impact of strain heterogeneity on the susceptibility of animals to infection. This information should provide a comprehensive reference for those interested in the study of arenaviruses and hantaviruses not only for MCM development but also in the study of viral pathogenesis and the biology of these viruses in their natural reservoirs. PMID:26266264
Martin-Ruiz, Carmen; Saretzki, Gabriele; Petrie, Joanne; Ladhoff, Juliane; Jeyapalan, Jessie; Wei, Wenyi; Sedivy, John; von Zglinicki, Thomas
2004-04-23
The replicative life span of human fibroblasts is heterogeneous, with a fraction of cells senescing at every population doubling. To find out whether this heterogeneity is due to premature senescence, i.e. driven by a nontelomeric mechanism, fibroblasts with a senescent phenotype were isolated from growing cultures and clones by flow cytometry. These senescent cells had shorter telomeres than their cycling counterparts at all population doubling levels and both in mass cultures and in individual subclones, indicating heterogeneity in the rate of telomere shortening. Ectopic expression of telomerase stabilized telomere length in the majority of cells and rescued them from early senescence, suggesting a causal role of telomere shortening. Under standard cell culture conditions, there was a minor fraction of cells that showed a senescent phenotype and short telomeres despite active telomerase. This fraction increased under chronic mild oxidative stress, which is known to accelerate telomere shortening. It is possible that even high telomerase activity cannot fully compensate for telomere shortening in all cells. The data show that heterogeneity of the human fibroblast replicative life span can be caused by significant stochastic cell-to-cell variation in telomere shortening.
Human activities cause distinct dissolved organic matter composition across freshwater ecosystems.
Williams, Clayton J; Frost, Paul C; Morales-Williams, Ana M; Larson, James H; Richardson, William B; Chiandet, Aisha S; Xenopoulos, Marguerite A
2016-02-01
Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by the interactions among physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition variation across freshwater ecosystems differentially affected by human activity. Using optical properties, we described DOM variation across five ecosystem groups of the Laurentian Great Lakes region: large lakes, Kawartha Lakes, Experimental Lakes Area, urban stormwater ponds, and rivers (n = 184 sites). We determined how between ecosystem variation in DOM composition related to watershed size, land use and cover, water quality measures (conductivity, dissolved organic carbon (DOC), nutrient concentration, chlorophyll a), and human population density. The five freshwater ecosystem groups had distinctive DOM composition from each other. These significant differences were not explained completely through differences in watershed size nor spatial autocorrelation. Instead, multivariate partial least squares regression showed that DOM composition was related to differences in human impact across freshwater ecosystems. In particular, urban/developed watersheds with higher human population densities had a unique DOM composition with a clear anthropogenic influence that was distinct from DOM composition in natural land cover and/or agricultural watersheds. This nonagricultural, human developed impact on aquatic DOM was most evident through increased levels of a microbial, humic-like parallel factor analysis component (C6). Lotic and lentic ecosystems with low human population densities had DOM compositions more typical of clear water to humic-rich freshwater ecosystems but C6 was only present at trace to background levels. Consequently, humans are strongly altering the quality of DOM in waters nearby or flowing through highly populated areas, which may alter carbon cycles in anthropogenically disturbed ecosystems at broad scales. © 2015 John Wiley & Sons Ltd.
Human activities cause distinct dissolved organic matter composition across freshwater ecosystems
Williams, Clayton J.; Frost, Paul C.; Morales-Williams, Ana M.; Larson, James H.; Richardson, William B.; Chiandet, Aisha S.; Xenopoulos, Marguerite A.
2016-01-01
Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by interactions between physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition variation across freshwater ecosystems differentially affected by human activity. Using optical properties, we described DOM variation across five ecosystem groups of the Laurentian Great Lakes Region: large lakes, Kawartha Lakes, Experimental Lakes Area, urban stormwater ponds, and rivers (n = 184 sites). We determined how between ecosystem variation in DOM composition related to watershed size, land use and cover, water quality measures (conductivity, dissolved organic carbon (DOC), nutrient concentration, chlorophyll a), and human population density. The five freshwater ecosystem groups had distinctive DOM composition from each other. These significant differences were not explained completely through differences in watershed size nor spatial autocorrelation. Instead, multivariate partial least squares regression showed that DOM composition was related to differences in human impact across freshwater ecosystems. In particular, urban/developed watersheds with higher human population densities had a unique DOM composition with a clear anthropogenic influence that was distinct from DOM composition in natural land cover and/or agricultural watersheds. This nonagricultural, human developed impact on aquatic DOM was most evident through increased levels of a microbial, humic-like parallel factor analysis component (C6). Lotic and lentic ecosystems with low human population densities had DOM compositions more typical of clear water to humic-rich freshwater ecosystems but C6 was only present at trace to background levels. Consequently, humans are strongly altering the quality of DOM in waters nearby or flowing through highly populated areas, which may alter carbon cycles in anthropogenically disturbed ecosystems at broad scales.
Harrison, Ewan M.; Weinert, Lucy A.; Holden, Matthew T. G.; Welch, John J.; Wilson, Katherine; Morgan, Fiona J. E.; Harris, Simon R.; Loeffler, Anette; Boag, Amanda K.; Peacock, Sharon J.; Paterson, Gavin K.; Waller, Andrew S.; Parkhill, Julian
2014-01-01
ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) is a global human health problem causing infections in both hospitals and the community. Companion animals, such as cats, dogs, and horses, are also frequently colonized by MRSA and can become infected. We sequenced the genomes of 46 multilocus sequence type (ST) 22 MRSA isolates from cats and dogs in the United Kingdom and compared these to an extensive population framework of human isolates from the same lineage. Phylogenomic analyses showed that all companion animal isolates were interspersed throughout the epidemic MRSA-15 (EMRSA-15) pandemic clade and clustered with human isolates from the United Kingdom, with human isolates basal to those from companion animals, suggesting a human source for isolates infecting companion animals. A number of isolates from the same veterinary hospital clustered together, suggesting that as in human hospitals, EMRSA-15 isolates are readily transmitted in the veterinary hospital setting. Genome-wide association analysis did not identify any host-specific single nucleotide polymorphisms (SNPs) or virulence factors. However, isolates from companion animals were significantly less likely to harbor a plasmid encoding erythromycin resistance. When this plasmid was present in animal-associated isolates, it was more likely to contain mutations mediating resistance to clindamycin. This finding is consistent with the low levels of erythromycin and high levels of clindamycin used in veterinary medicine in the United Kingdom. This study furthers the “one health” view of infectious diseases that the pathogen pool of human and animal populations are intrinsically linked and provides evidence that antibiotic usage in animal medicine is shaping the population of a major human pathogen. PMID:24825010
Global climate and infectious disease: The cholera paradigm
DOE Office of Scientific and Technical Information (OSTI.GOV)
Colwell, R.R.
1996-12-20
Historically, infectious diseases have had a profound effect on human populations, including their evolution and cultural development. Despite significant advances in medical science, infectious diseases continue to impact human populations in many parts of the world. Emerging diseases are considered to be those infections that either are newly appearing in the population or are rapidly increasing in incidence or expanding in geographic range. Emergence of disease is not a simple phenomenon, mainly because infectious diseases are dynamic. Most new infections are not caused by truly new pathogens but are microorganisms (viruses, bacteria, fungi, protozoa, and helminths) that find a newmore » way to enter a susceptible host and are newly recognized because of recently developed, sensitive techniques. Human activities drive emergence of disease and a variety of social, economic, political, climatic, technological, and environmental factors can shape the pattern of a disease and influence its emergence into populations. For example, travel affects emergence of disease, and human migrations have been the main source of epidemics throughout history. Trade caravans, religious pilgrimage, and military campaigns facilitated the spread of plague, smallpox, and cholera. Global travel is a fact of modern life and, equally so, the continued evolution of microorganisms; therefore, new infections will continue to emerge, and known infections will change in distribution, frequency, and severity. 88 refs., 1 fig.« less
Zoonotic aspects of vector-borne infections.
Failloux, A-B; Moutailler, S
2015-04-01
Vector-borne diseases are principally zoonotic diseases transmitted to humans by animals. Pathogens such as bacteria, parasites and viruses are primarily maintained within an enzootic cycle between populations of non-human primates or other mammals and largely non-anthropophilic vectors. This 'wild' cycle sometimes spills over in the form of occasional infections of humans and domestic animals. Lifestyle changes, incursions by humans into natural habitats and changes in agropastoral practices create opportunities that make the borders between wildlife and humans more permeable. Some vector-borne diseases have dispensed with the need for amplification in wild or domestic animals and they can now be directly transmitted to humans. This applies to some viruses (dengue and chikungunya) that have caused major epidemics. Bacteria of the genus Bartonella have reduced their transmission cycle to the minimum, with humans acting as reservoir, amplifier and disseminator. The design of control strategies for vector-borne diseases should be guided by research into emergence mechanisms in order to understand how a wild cycle can produce a pathogen that goes on to cause devastating urban epidemics.
Persons With Disabilities as an Unrecognized Health Disparity Population
Walker, Deborah Klein; Correa-De-Araujo, Rosaly
2015-01-01
Disability is an emerging field within public health; people with significant disabilities account for more than 12% of the US population. Disparity status for this group would allow federal and state governments to actively work to reduce inequities. We summarize the evidence and recommend that observed differences are sufficient to meet the criteria for health disparities: population-level differences in health outcomes that are related to a history of wide-ranging disadvantages, which are avoidable and not primarily caused by the underlying disability. We recommend future research and policy directions to address health inequities for individuals with disabilities; these include improved access to health care and human services, increased data to support decision-making, strengthened health and human services workforce capacity, explicit inclusion of disability in public health programs, and increased emergency preparedness. PMID:25689212
Ancient Dispersal of the Human Fungal Pathogen Cryptococcus gattii from the Amazon Rainforest
Hagen, Ferry; Ceresini, Paulo C.; Polacheck, Itzhack; Ma, Hansong; van Nieuwerburgh, Filip; Gabaldón, Toni; Kagan, Sarah; Pursall, E. Rhiannon; Hoogveld, Hans L.; van Iersel, Leo J. J.; Klau, Gunnar W.; Kelk, Steven M.; Stougie, Leen; Bartlett, Karen H.; Voelz, Kerstin; Pryszcz, Leszek P.; Castañeda, Elizabeth; Lazera, Marcia; Meyer, Wieland; Deforce, Dieter; Meis, Jacques F.; May, Robin C.; Klaassen, Corné H. W.; Boekhout, Teun
2013-01-01
Over the past two decades, several fungal outbreaks have occurred, including the high-profile ‘Vancouver Island’ and ‘Pacific Northwest’ outbreaks, caused by Cryptococcus gattii, which has affected hundreds of otherwise healthy humans and animals. Over the same time period, C. gattii was the cause of several additional case clusters at localities outside of the tropical and subtropical climate zones where the species normally occurs. In every case, the causative agent belongs to a previously rare genotype of C. gattii called AFLP6/VGII, but the origin of the outbreak clades remains enigmatic. Here we used phylogenetic and recombination analyses, based on AFLP and multiple MLST datasets, and coalescence gene genealogy to demonstrate that these outbreaks have arisen from a highly-recombining C. gattii population in the native rainforest of Northern Brazil. Thus the modern virulent C. gattii AFLP6/VGII outbreak lineages derived from mating events in South America and then dispersed to temperate regions where they cause serious infections in humans and animals. PMID:23940707
Ancient dispersal of the human fungal pathogen Cryptococcus gattii from the Amazon rainforest.
Hagen, Ferry; Ceresini, Paulo C; Polacheck, Itzhack; Ma, Hansong; van Nieuwerburgh, Filip; Gabaldón, Toni; Kagan, Sarah; Pursall, E Rhiannon; Hoogveld, Hans L; van Iersel, Leo J J; Klau, Gunnar W; Kelk, Steven M; Stougie, Leen; Bartlett, Karen H; Voelz, Kerstin; Pryszcz, Leszek P; Castañeda, Elizabeth; Lazera, Marcia; Meyer, Wieland; Deforce, Dieter; Meis, Jacques F; May, Robin C; Klaassen, Corné H W; Boekhout, Teun
2013-01-01
Over the past two decades, several fungal outbreaks have occurred, including the high-profile 'Vancouver Island' and 'Pacific Northwest' outbreaks, caused by Cryptococcus gattii, which has affected hundreds of otherwise healthy humans and animals. Over the same time period, C. gattii was the cause of several additional case clusters at localities outside of the tropical and subtropical climate zones where the species normally occurs. In every case, the causative agent belongs to a previously rare genotype of C. gattii called AFLP6/VGII, but the origin of the outbreak clades remains enigmatic. Here we used phylogenetic and recombination analyses, based on AFLP and multiple MLST datasets, and coalescence gene genealogy to demonstrate that these outbreaks have arisen from a highly-recombining C. gattii population in the native rainforest of Northern Brazil. Thus the modern virulent C. gattii AFLP6/VGII outbreak lineages derived from mating events in South America and then dispersed to temperate regions where they cause serious infections in humans and animals.
Eckert, Johannes; Deplazes, Peter
2004-01-01
Echinococcosis in humans is a zoonotic infection caused by larval stages (metacestodes) of cestode species of the genus Echinococcus. Cystic echinococcosis (CE) is caused by Echinococcus granulosus, alveolar echinococcosis (AE) is caused by E. multilocularis, and polycystic forms are caused by either E. vogeli or E. oligarthrus. In untreated cases, AE has a high mortality rate. Although control is essentially feasible, CE remains a considerable health problem in many regions of the northern and southern hemispheres. AE is restricted to the northern hemisphere regions of North America and Eurasia. Recent studies have shown that E. multilocularis, the causative agent of AE, is more widely distributed than previously thought. There are also some hints of an increasing significance of polycystic forms of the disease, which are restricted to Central and South America. Various aspects of human echinococcosis are discussed in this review, including data on the infectivity of genetic variants of E. granulosus to humans, the increasing invasion of cities in Europe and Japan by red foxes, the main definitive hosts of E. multilocularis, and the first demonstration of urban cycles of the parasite. Examples of emergence or reemergence of CE are presented, and the question of potential spreading of E. multilocularis is critically assessed. Furthermore, information is presented on new and improved tools for diagnosing the infection in final hosts (dogs, foxes, and cats) by coproantigen or DNA detection and the application of molecular techniques to epidemiological studies. In the clinical field, the available methods for diagnosing human CE and AE are described and the treatment options are summarized. The development of new chemotherapeutic options for all forms of human echinococcosis remains an urgent requirement. A new option for the control of E. granulosus in the intermediate host population (mainly sheep and cattle) is vaccination. Attempts are made to reduce the prevalence of E. multilocualaris in fox populations by regular baiting with an anthelmintic (praziquantel). Recent data have shown that this control option may be used in restricted areas, for example in cities, with the aim of reducing the infection risk for humans. PMID:14726458
A voyage to Terra Australis: human-mediated dispersal of cats.
Koch, K; Algar, D; Searle, J B; Pfenninger, M; Schwenk, K
2015-12-04
Cats have been transported as human commensals worldwide giving rise to many feral populations. In Australia, feral cats have caused decline and extinction of native mammals, but their time of introduction and origin is unclear. Here, we investigate hypotheses of cat arrival pre- or post-European settlement, and the potential for admixture between cats of different invasion events. We analyse the genetic structure and diversity of feral cats from six locations on mainland Australia, seven Australian islands and samples from Southeast Asia and Europe using microsatellite and mitochondrial DNA data. Our results based on phylogeographic model selection are consistent with a European origin of cats in Australia. We find genetic distinctiveness of Australian mainland samples compared with Dirk Hartog Island, Flinders Island, Tasman Island and Cocos (Keeling) Island samples, and genetic similarities between some of the island populations. Historical records suggest that introduction of cats to these islands occurred at the time of European exploration and/or in connection with the pearling, whaling and sealing trades early in the 19th century. On-going influx of domestic cats into the feral cat population is apparently causing the Australian mainland populations to be genetically differentiated from those island populations, which likely are remnants of the historically introduced cat genotypes. A mainly European origin of feral cats in Australia, with possible secondary introductions from Asia following the initial establishment of cats in Australia is reasonable. The islands surrounding Australia may represent founding populations and are of particular interest. The results of the study provide an important timeframe for the impact of feral cats on native species in Australia.
Rabaa, Maia A; Tue, Ngo Tri; Phuc, Tran My; Carrique-Mas, Juan; Saylors, Karen; Cotten, Matthew; Bryant, Juliet E; Nghia, Ho Dang Trung; Cuong, Nguyen Van; Pham, Hong Anh; Berto, Alessandra; Phat, Voong Vinh; Dung, Tran Thi Ngoc; Bao, Long Hoang; Hoa, Ngo Thi; Wertheim, Heiman; Nadjm, Behzad; Monagin, Corina; van Doorn, H Rogier; Rahman, Motiur; Tra, My Phan Vu; Campbell, James I; Boni, Maciej F; Tam, Pham Thi Thanh; van der Hoek, Lia; Simmonds, Peter; Rambaut, Andrew; Toan, Tran Khanh; Van Vinh Chau, Nguyen; Hien, Tran Tinh; Wolfe, Nathan; Farrar, Jeremy J; Thwaites, Guy; Kellam, Paul; Woolhouse, Mark E J; Baker, Stephen
2015-12-01
The effect of newly emerging or re-emerging infectious diseases of zoonotic origin in human populations can be potentially catastrophic, and large-scale investigations of such diseases are highly challenging. The monitoring of emergence events is subject to ascertainment bias, whether at the level of species discovery, emerging disease events, or disease outbreaks in human populations. Disease surveillance is generally performed post hoc, driven by a response to recent events and by the availability of detection and identification technologies. Additionally, the inventory of pathogens that exist in mammalian and other reservoirs is incomplete, and identifying those with the potential to cause disease in humans is rarely possible in advance. A major step in understanding the burden and diversity of zoonotic infections, the local behavioral and demographic risks of infection, and the risk of emergence of these pathogens in human populations is to establish surveillance networks in populations that maintain regular contact with diverse animal populations, and to simultaneously characterize pathogen diversity in human and animal populations. Vietnam has been an epicenter of disease emergence over the last decade, and practices at the human/animal interface may facilitate the likelihood of spillover of zoonotic pathogens into humans. To tackle the scientific issues surrounding the origins and emergence of zoonotic infections in Vietnam, we have established The Vietnam Initiative on Zoonotic Infections (VIZIONS). This countrywide project, in which several international institutions collaborate with Vietnamese organizations, is combining clinical data, epidemiology, high-throughput sequencing, and social sciences to address relevant one-health questions. Here, we describe the primary aims of the project, the infrastructure established to address our scientific questions, and the current status of the project. Our principal objective is to develop an integrated approach to the surveillance of pathogens circulating in both human and animal populations and assess how frequently they are exchanged. This infrastructure will facilitate systematic investigations of pathogen ecology and evolution, enhance understanding of viral cross-species transmission events, and identify relevant risk factors and drivers of zoonotic disease emergence.
Jaung, Michael; Jani, Suni; Banu, Sophia; Mackey, Joy M
2017-09-01
Mental health disorders are a major cause of morbidity and a growing burden in low-income and middle-income countries; but there is little existing literature on the detailed epidemiology, diagnosis, and treatment in low-resource settings. Special situations with vulnerable populations, such as those created by international humanitarian emergencies, refugees or internally displaced people, and victims of human trafficking, are increasing in prevalence. These victims are often resettled in developed countries and come to the emergency department seeking care. To better care for these populations, knowledge of specialized psychosocial and cultural considerations should inform the comprehensive psychiatric assessment and treatment plan. Copyright © 2017 Elsevier Inc. All rights reserved.
Schmidt, Wolf-Peter; Suzuki, Motoi; Thiem, Vu Dinh; White, Richard G; Tsuzuki, Ataru; Yoshida, Lay-Myint; Yanai, Hideki; Haque, Ubydul; Tho, Le Huu; Anh, Dang Duc; Ariyoshi, Koya
2011-08-01
Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary.
Schmidt, Wolf-Peter; Suzuki, Motoi; Dinh Thiem, Vu; White, Richard G.; Tsuzuki, Ataru; Yoshida, Lay-Myint; Yanai, Hideki; Haque, Ubydul; Huu Tho, Le; Anh, Dang Duc; Ariyoshi, Koya
2011-01-01
Background Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. Methods and Findings We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km2 prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. Conclusions Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary PMID:21918642
Human impacts on bear habitat use
Mattson, David J.
1990-01-01
: Human effects on bear habitat use are mediated through food biomass changes, bear tolerance of humans and their impacts, and human tolerance of bears. Large-scale changes in bear food biomass have been caused by conversion of wildlands and waterways to intensive human use, and by the introduction of exotic pathogens. Bears consume virtually all human foods that have been established in former wildlands, but bear use has been limited by access. Air pollution has also affected bear food biomass on a small scale and is likely to have major future impacts on bear habitat through climatic warming. Major changes in disturbance cycles and landscape mosaics wrought by humans have further altered temporal and spatial pulses of bear food production. These changes have brought short-term benefits in places, but have also added long-term stresses to most bear populations. Although bears tend to avoid humans, they will also use exotic and native foods in close proximity to humans. Subadult males and adult females are more often impelled to forage closer to humans because of their energetic predicament and because more secure sites are often preempted by adult males. Although male bears are typically responsible for most livestock predation, adult females and subadult males are more likely to be habituated to humans because they tend to forage closer to humans. Elimination of human-habituated bears predictably reduces effective carrying capacity and is more likely to be a factor in preserving bear populations where humans are present in moderate-to-high densities. If humans desire to preserve viable bear populations, they will either have to accept increased risk of injury associated with preserving habituated animals, or continue to crop habituated bears while at the same time preserving large tracts of wildlands free from significant human intrusion.
Teaching Elementary Probability and Statistics: Some Applications in Epidemiology.
ERIC Educational Resources Information Center
Sahai, Hardeo; Reesal, Michael R.
1992-01-01
Illustrates some applications of elementary probability and statistics to epidemiology, the branch of medical science that attempts to discover associations between events, patterns, and the cause of disease in human populations. Uses real-life examples involving cancer's link to smoking and the AIDS virus. (MDH)
The relation between land use and subsidence in the Vietnamese Mekong delta
The Vietnamese Mekong delta is subsiding due to a combination of natural and human-induced causes. Over the past several decades, large-scale anthropogenic land-use changes have taken place as a result of increased agricultural production, population growth and urbanization in th...
DISINFECTION BY-PRODUCTS OF EMERGING CONCERN: RESULTS OF A U.S. NATIONWIDE OCCURRENCE STUDY
Drinking water disinfection by-products (DBPs) are of concern because some epidemiologic studies have shown that some DBPs are associated with cancer or adverse reproductive/developmental effects in human populations and other studies have shown that certain DBPs cause similar he...
Cardiovascular diseases (CVD) are the number one cause for human mortality and nearly 25% of the population develops chronic CVD at an age of 65 years or older. Environmental and genetic interactions govern pathogenesis. Increased oxidative stress and compromised antioxidant stat...
Lifeboat Ethics: A Reply to Hardin
ERIC Educational Resources Information Center
Besecker, Janet; Elder, Phil
1975-01-01
This paper is a rebuttal to Garrett Hardin's thesis that long-term survival of human beings can be threatened by environmental devastation caused by brief humanitarian desires to save lives. Discussions include population dynamics, resource distribution, ecological stability, and ethics of developed nations and undeveloped nations relationships.…
Zhang, Li-Juan; Cai, Wan-Zhi; Luo, Jun-Yu; Zhang, Shuai; Wang, Chun-Yi; Lv, Li-Min; Zhu, Xiang-Zhen; Wang, Li; Cui, Jin-Jie
2017-01-01
Lygus pratensis (L.) is an important cotton pest in China, especially in the northwest region. Nymphs and adults cause serious quality and yield losses. However, the genetic structure and geographic distribution of L. pratensis is not well known. We analyzed genetic diversity, geographical structure, gene flow, and population dynamics of L. pratensis in northwest China using mitochondrial and nuclear sequence datasets to study phylogeographical patterns and demographic history. L. pratensis (n = 286) were collected at sites across an area spanning 2,180,000 km2, including the Xinjiang and Gansu-Ningxia regions. Populations in the two regions could be distinguished based on mitochondrial criteria but the overall genetic structure was weak. The nuclear dataset revealed a lack of diagnostic genetic structure across sample areas. Phylogenetic analysis indicated a lack of population level monophyly that may have been caused by incomplete lineage sorting. The Mantel test showed a significant correlation between genetic and geographic distances among the populations based on the mtDNA data. However the nuclear dataset did not show significant correlation. A high level of gene flow among populations was indicated by migration analysis; human activities may have also facilitated insect movement. The availability of irrigation water and ample cotton hosts makes the Xinjiang region well suited for L. pratensis reproduction. Bayesian skyline plot analysis, star-shaped network, and neutrality tests all indicated that L. pratensis has experienced recent population expansion. Climatic changes and extensive areas occupied by host plants have led to population expansion of L. pratensis. In conclusion, the present distribution and phylogeographic pattern of L. pratensis was influenced by climate, human activities, and availability of plant hosts.
Reil, Daniela; Imholt, Christian; Eccard, Jana Anja; Jacob, Jens
2015-01-01
The transmission of wildlife zoonoses to humans depends, amongst others, on complex interactions of host population ecology and pathogen dynamics within host populations. In Europe, the Puumala virus (PUUV) causes nephropathia epidemica in humans. In this study we investigated complex interrelations within the epidemic system of PUUV and its rodent host, the bank vole (Myodes glareolus). We suggest that beech fructification and bank vole abundance are both decisive factors affecting human PUUV infections. While rodent host dynamics are expected to be directly linked to human PUUV infections, beech fructification is a rather indirect predictor by serving as food source for PUUV rodent hosts. Furthermore, we examined the dependence of bank vole abundance on beech fructification. We analysed a 12-year (2001-2012) time series of the parameters: beech fructification (as food resource for the PUUV host), bank vole abundance and human incidences from 7 Federal States of Germany. For the first time, we could show the direct interrelation between these three parameters involved in human PUUV epidemics and we were able to demonstrate on a large scale that human PUUV infections are highly correlated with bank vole abundance in the present year, as well as beech fructification in the previous year. By using beech fructification and bank vole abundance as predictors in one model we significantly improved the degree of explanation of human PUUV incidence. Federal State was included as random factor because human PUUV incidence varies considerably among states. Surprisingly, the effect of rodent abundance on human PUUV infections is less strong compared to the indirect effect of beech fructification. Our findings are useful to facilitate the development of predictive models for host population dynamics and the related PUUV infection risk for humans and can be used for plant protection and human health protection purposes. PMID:26214509
Reil, Daniela; Imholt, Christian; Eccard, Jana Anja; Jacob, Jens
2015-01-01
The transmission of wildlife zoonoses to humans depends, amongst others, on complex interactions of host population ecology and pathogen dynamics within host populations. In Europe, the Puumala virus (PUUV) causes nephropathia epidemica in humans. In this study we investigated complex interrelations within the epidemic system of PUUV and its rodent host, the bank vole (Myodes glareolus). We suggest that beech fructification and bank vole abundance are both decisive factors affecting human PUUV infections. While rodent host dynamics are expected to be directly linked to human PUUV infections, beech fructification is a rather indirect predictor by serving as food source for PUUV rodent hosts. Furthermore, we examined the dependence of bank vole abundance on beech fructification. We analysed a 12-year (2001-2012) time series of the parameters: beech fructification (as food resource for the PUUV host), bank vole abundance and human incidences from 7 Federal States of Germany. For the first time, we could show the direct interrelation between these three parameters involved in human PUUV epidemics and we were able to demonstrate on a large scale that human PUUV infections are highly correlated with bank vole abundance in the present year, as well as beech fructification in the previous year. By using beech fructification and bank vole abundance as predictors in one model we significantly improved the degree of explanation of human PUUV incidence. Federal State was included as random factor because human PUUV incidence varies considerably among states. Surprisingly, the effect of rodent abundance on human PUUV infections is less strong compared to the indirect effect of beech fructification. Our findings are useful to facilitate the development of predictive models for host population dynamics and the related PUUV infection risk for humans and can be used for plant protection and human health protection purposes.
Bai, Haihua; Guo, Xiaosen; Zhang, Dong; Narisu, Narisu; Bu, Junjie; Jirimutu, Jirimutu; Liang, Fan; Zhao, Xiang; Xing, Yanping; Wang, Dingzhu; Li, Tongda; Zhang, Yanru; Guan, Baozhu; Yang, Xukui; Yang, Zili; Shuangshan, Shuangshan; Su, Zhe; Wu, Huiguang; Li, Wenjing; Chen, Ming; Zhu, Shilin; Bayinnamula, Bayinnamula; Chang, Yuqi; Gao, Ying; Lan, Tianming; Suyalatu, Suyalatu; Huang, Hui; Su, Yan; Chen, Yujie; Li, Wenqi; Yang, Xu; Feng, Qiang; Wang, Jian; Yang, Huanming; Wang, Jun; Wu, Qizhu; Yin, Ye; Zhou, Huanmin
2014-11-05
Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]-1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Health Impacts from Human Interaction with the Environment
NASA Astrophysics Data System (ADS)
Hasan, S. E.
2008-12-01
Humans have produced far greater impact on the environment than any other living form. The impact has been so significant-particularly during the past 50 years-that a new word, Anthrposphere has started appearing in recent literature. It is now being used along with the four major components of the system earth to underscore humans' influence on the environment. Human activities have produced a myriad of impacts on the environment that span the scale from local to global. The slow process that brought humanity to the present environmental crisis began with the Industrial Revolution and has greatly accelerated since the World War II. The past 50 years mark a unique period in human history that is characterized by rapid technological advances and unprecedented population growth. While the use of technology has been very effective in meeting the needs of the growing population, it has also produced serious impact on the environment. Large scale exploitation of mineral, fuel, water, forest, and marine resources has led to severe environmental degradation; and the resulting pollution of air, water, and land has caused serious consequences to human and ecological health. The presentation deals with the adverse impact on human health associated with mining, dam and reservoir construction, improper waste management, use of fossil fuels, and climate change. Case studies are included to illustrate health impacts from metal and coal mining; dam and reservoir construction and preponderance of disease vectors; pollution caused by improper waste disposal and the resulting incidence of cancer and other diseases; and emergence of vector-borne diseases at hitherto unknown locations, cardiovascular and respiratory track ailments, and increased morbidity and mortality triggered by elevated temperatures associated with climate change. A brief discussion of possible measures to mitigate the health consequences is also included in the presentation.
Pinho, M. D.; Matos, S. C.; Pomba, C.; Lübke-Becker, A.; Wieler, L. H.; Preziuso, S.; Melo-Cristino, J.
2013-01-01
Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection. PMID:23345291
Pinho, M D; Matos, S C; Pomba, C; Lübke-Becker, A; Wieler, L H; Preziuso, S; Melo-Cristino, J; Ramirez, M
2013-04-01
Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection.
Bauman, Jessica; Wirth, Lori
2015-01-01
Human papillomavirus (HPV) is now considered a major causative agent in oropharyngeal squamous cell carcinoma (OP-SCC). The incidence of HPV+ OP-SCC is increasing dramatically, is higher in men, and is now more common than cervical cancer in the United States. HPV+ OPSCCs usually present as locally advanced, stage IV cancers, requiring intensive treatment with surgery, chemotherapy, and/or radiation that can cause tremendous morbidity. HPV vaccination is predicted to prevent HPV+ OP-SCC because over 90% are caused by vaccine-type HPV. However, current vaccination rates are not yet high enough to be effective at preventing HPV-associated malignancies at a population level. PMID:27132327
Associations between Periodontal Microbiota and Death Rates.
Chiu, Chung-Jung; Chang, Min-Lee; Taylor, Allen
2016-10-17
It is conceived that specific combinations of periodontal bacteria are associated with risk for the various forms of periodontitis. We hypothesized that such specificity is also related to human cause-specific death rates. We tested this hypothesis in a representative sample of the US population followed for a mean duration of 11 years and found that two specific patterns of 21 serum antibodies against periodontal bacteria were significantly associated with increased all-cause and/or diabetes-related mortalities. These data suggested that specific combinations of periodontal bacteria, even without inducing clinically significant periodontitis, may have a significant impact on human cause-specific death rates. Our findings implied that increased disease and mortality risk could be transmittable via the transfer of oral microbiota, and that developing personalized strategies and maintaining healthy oral microbiota beyond protection against periodontitis would be important to manage the risk.
Izmerov, N F; Tikhonova, G I; Gorchakova, T Iu
2014-01-01
The purpose of the study was to carry out comparative analysis of the status and trends in mortality of male and female population of working age (15-59 (54) years) in Russia and the EU-27. Based on official Russian (Rosstat) data, on the global database of the World Health Organization's cause of death (The WHO Mortality Database, WHOMD) and databases The Human Mortality Database (HMD) of the sex-age composition of the population and the number of deaths from certain causes of death by age and sex standardized (direct method) mortality rates of working age population from selected causes of death for 1990 and 2011 in Russia and the average for the EU-27 were calculated. Analysis of trends in mortality of male and female population of working age in Russia over the past two decades shows that, despite the positive changes in during last six years, in 2011, age-standardized mortality rates remained above the 1990 level for most causes of death. During the same period in the EU-27 mortality in men (15-59 years) and women (15-54 years) increased from almost all causes ofdeath, which led to an even greatergap between Russia and developed countries on this indicator: standardized mortality rate of the male population of Russia in 1990 was higher than in the EU-27 by 2.1 times, and by 2011 the gap had increased to 3.5 times. The women in the 1990 had 1.5 times higher standardized mortality rates, and by 2011 the gap had increased to 2.7 times. Despite a steady decline in the mortality rates of working age population after 2005, its level in 2012 was still higher than the one of 1990 for both men and women, which led to a further increase in the gap between the age-standardized coefficients of mortality rate of working age population in Russia and the countries of European Community-27 (15-59 (54)). Faster reduction of mortality rate in the working age population will preserve Russian population and its labor potential.
Resilience and risk: a demographic model to inform conservation planning for polar bears
Regehr, Eric V.; Wilson, Ryan R.; Rode, Karyn D.; Runge, Michael C.
2015-01-01
Our modeling results suggest that harvest of polar bears is unlikely to accelerate population declines that result from declining carrying capacity caused by sea-ice loss, provided that several conditions are met: (1) the sustainable harvest rate reflects the population’s intrinsic growth rate, and the corresponding harvest level is obtained by applying this rate to an estimate of population size; (2) the sustainable harvest rate reflects the quality of population data (e.g., lower harvest when data are poor); and (3) the level of human-caused removals can be adjusted. Finally, our results suggest that stopgap measures (e.g., further reduction or cessation of harvest when the population size is less than a critical threshold) may be necessary to minimize the incremental risk associated with harvest, if environmental conditions are deteriorating rapidly. We suggest that the demographic model and approaches presented here can serve as a template for conservation planning for polar bears and other species facing similar challenges.
Gonzalez-Cordero, Anai; Kruczek, Kamil; Naeem, Arifa; Fernando, Milan; Kloc, Magdalena; Ribeiro, Joana; Goh, Debbie; Duran, Yanai; Blackford, Samuel J I; Abelleira-Hervas, Laura; Sampson, Robert D; Shum, Ian O; Branch, Matthew J; Gardner, Peter J; Sowden, Jane C; Bainbridge, James W B; Smith, Alexander J; West, Emma L; Pearson, Rachael A; Ali, Robin R
2017-09-12
Transplantation of rod photoreceptors, derived either from neonatal retinae or pluripotent stem cells (PSCs), can restore rod-mediated visual function in murine models of inherited blindness. However, humans depend more upon cone photoreceptors that are required for daylight, color, and high-acuity vision. Indeed, macular retinopathies involving loss of cones are leading causes of blindness. An essential step for developing stem cell-based therapies for maculopathies is the ability to generate transplantable human cones from renewable sources. Here, we report a modified 2D/3D protocol for generating hPSC-derived neural retinal vesicles with well-formed ONL-like structures containing cones and rods bearing inner segments and connecting cilia, nascent outer segments, and presynaptic structures. This differentiation system recapitulates human photoreceptor development, allowing the isolation and transplantation of a pure population of stage-matched cones. Purified human long/medium cones survive and become incorporated within the adult mouse retina, supporting the potential of photoreceptor transplantation for treating retinal degeneration. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Schielzeth, Holger; Rios Villamil, Alejandro; Burri, Reto
2018-03-25
Recent developments in sequencing technologies have facilitated genomewide mapping of phenotypic variation in natural populations. Such mapping efforts face a number of challenges potentially leading to low reproducibility. However, reproducible research forms the basis of scientific progress. We here discuss the options for replication and the reasons for potential nonreproducibility. We then review the evidence for reproducible quantitative trait loci (QTL) with a focus on natural animal populations. Existing case studies of replication fall into three categories: (i) traits that have been mapped to major effect loci (including chromosomal inversion and supergenes) by independent research teams; (ii) QTL fine-mapped in discovery populations; and (iii) attempts to replicate QTL across multiple populations. Major effect loci, in particular those associated with inversions, have been successfully replicated in several cases within and across populations. Beyond such major effect variants, replication has been more successful within than across populations, suggesting that QTL discovered in natural populations may often be population-specific. This suggests that biological causes (differences in linkage patterns, allele frequencies or context-dependencies of QTL) contribute to nonreproducibility. Evidence from other fields, notably animal breeding and QTL mapping in humans, suggests that a significant fraction of QTL is indeed reproducible in direction and magnitude at least within populations. However, there is also a large number of QTL that cannot be easily reproduced. We put forward that more studies should explicitly address the causes and context-dependencies of QTL signals, in particular to disentangle linkage differences, allele frequency differences and gene-by-environment interactions as biological causes of nonreproducibility of QTL, especially between populations. © 2018 John Wiley & Sons Ltd.
Flint, Annika; Stintzi, Alain; Saraiva, Lígia M.
2016-01-01
Helicobacter and Campylobacter species are Gram-negative microaerophilic host-associated heterotrophic bacteria that invade the digestive tract of humans and animals. Campylobacter jejuni is the major worldwide cause of foodborne gastroenteritis in humans, while Helicobacter pylori is ubiquitous in over half of the world's population causing gastric and duodenal ulcers. The colonisation of the gastrointestinal system by Helicobacter and Campylobacter relies on numerous cellular defences to sense the host environment and respond to adverse conditions, including those imposed by the host immunity. An important antimicrobial tool of the mammalian innate immune system is the generation of harmful oxidative and nitrosative stresses to which pathogens are exposed during phagocytosis. This review summarises the regulators, detoxifying enzymes and subversion mechanisms of Helicobacter and Campylobacter that ultimately promote the successful infection of humans. PMID:28201757
Technical guidelines for the application of seasonal influenza vaccine in China (2014–2015)
Feng, Luzhao; Yang, Peng; Zhang, Tao; Yang, Juan; Fu, Chuanxi; Qin, Ying; Zhang, Yi; Ma, Chunna; Liu, Zhaoqiu; Wang, Quanyi; Zhao, Genming; Yu, Hongjie
2015-01-01
Influenza, caused by the influenza virus, is a respiratory infectious disease that can severely affect human health. Influenza viruses undergo frequent antigenic changes, thus could spread quickly. Influenza causes seasonal epidemics and outbreaks in public gatherings such as schools, kindergartens, and nursing homes. Certain populations are at risk for severe illness from influenza, including pregnant women, young children, the elderly, and people in any ages with certain chronic diseases. PMID:26042462
Human Influenza Virus Infections.
Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole
2016-08-01
Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Trifonova, E A; Eremina, E R; Urnov, F D; Stepanov, V A
2012-01-01
The structure of the haplotypes and linkage disequilibrium (LD) of the methylenetetrahydrofolate reductase gene (MTHFR) in 9 population groups from Northern Eurasia and populations of the international HapMap project was investigated in the present study. The data suggest that the architecture of LD in the human genome is largely determined by the evolutionary history of populations; however, the results of phylogenetic and haplotype analyses seems to suggest that in fact there may be a common "old" mechanism for the formation of certain patterns of LD. Variability in the structure of LD and the level of diversity of MTHFRhaplotypes cause a certain set of tagSNPs with an established prognostic significance for each population. In our opinion, the results obtained in the present study are of considerable interest for understanding multiple genetic phenomena: namely, the association of interpopulation differences in the patterns of LD with structures possessing a genetic susceptibility to complex diseases, and the functional significance of the pleiotropicMTHFR gene effect. Summarizing the results of this study, a conclusion can be made that the genetic variability analysis with emphasis on the structure of LD in human populations is a powerful tool that can make a significant contribution to such areas of biomedical science as human evolutionary biology, functional genomics, genetics of complex diseases, and pharmacogenomics.
Human-induced evolution caused by unnatural selection through harvest of wild animals
Allendorf, Fred W.; Hard, Jeffrey J.
2009-01-01
Human harvest of phenotypically desirable animals from wild populations imposes selection that can reduce the frequencies of those desirable phenotypes. Hunting and fishing contrast with agricultural and aquacultural practices in which the most desirable animals are typically bred with the specific goal of increasing the frequency of desirable phenotypes. We consider the potential effects of harvest on the genetics and sustainability of wild populations. We also consider how harvesting could affect the mating system and thereby modify sexual selection in a way that might affect recruitment. Determining whether phenotypic changes in harvested populations are due to evolution, rather than phenotypic plasticity or environmental variation, has been problematic. Nevertheless, it is likely that some undesirable changes observed over time in exploited populations (e.g., reduced body size, earlier sexual maturity, reduced antler size, etc.) are due to selection against desirable phenotypes—a process we call “unnatural” selection. Evolution brought about by human harvest might greatly increase the time required for over-harvested populations to recover once harvest is curtailed because harvesting often creates strong selection differentials, whereas curtailing harvest will often result in less intense selection in the opposing direction. We strongly encourage those responsible for managing harvested wild populations to take into account possible selective effects of harvest management and to implement monitoring programs to detect exploitation-induced selection before it seriously impacts viability. PMID:19528656
Patterns of demographic change in the Americas.
Ubelaker, D H
1992-06-01
Considerable scholarly debate has focused on the nature of demographic change in the Americas before and after 1492. Recent research on human skeletal samples and related archeological materials suggests that morbidity and mortality were increasing throughout much of the Western Hemisphere before 1492 in response to increased population density, increased sedentism, and changing subsistence. The evidence suggests that after 1492 population reduction was caused not by continental pandemics but by localized or regional epidemics augmented by social and economic disruption. The twentieth century has witnessed remarkable Native American population recovery, fueled both by improvements in health care and changing definitions of "being Indian."
Exitus: An Agent-Based Evacuation Simulation Model for Heterogeneous Populations
ERIC Educational Resources Information Center
Manley, Matthew T.
2012-01-01
Evacuation planning for private-sector organizations is an important consideration given the continuing occurrence of both natural and human-caused disasters that inordinately affect them. Unfortunately, the traditional management approach that is focused on fire drills presents several practical challenges at the scale required for many…
Evaluation of phage treatment as a strategy to reduce Salmonella populations in growing swine
USDA-ARS?s Scientific Manuscript database
Salmonella is a foodborne pathogenic bacterium that causes human illnesses, morbidity, and mortality in swine. Bacteriophages are viruses naturally found in food animals that prey on bacteria, and have been suggested as a potential intervention strategy to reduce Salmonella levels in the live anima...
Drinking water disinfection by-products (DBPs) are of concern because some epidemiologic studies have shown that some DBPs are associated with cancer or adverse reproductive/developmental effects in human populations, and other studies have shown that certain DBPs cause similar h...
Drinking water disinfection by-products (DBPs) are of concern because some epidemiologic studies have shown that some DBPs are associated with cancer or adverse reproductive/developmental effects in human populations, and other studies have shown that certain DBPs cause similar h...
Watershed development is a leading cause of stream impairment, and it increasingly threatens the availability, quality, and sustainability of freshwater resources as human populations continue to grow and migrate. Most efforts have focused on trying to improve ecological conditio...
USDA-ARS?s Scientific Manuscript database
Pediatric drug development is hampered by the various biological, clinical, and formulation challenges associated with age-based populations. A primary cause for this lack of development is the inability to accurately predict ontogenic changes that affect pharmacokinetics (PK) in children using trad...
White snakeroot poisoning in goats: Variations in toxicity with different plant chemotypes
USDA-ARS?s Scientific Manuscript database
White Snakeroot is a toxic plant that causes human and livestock diseases known as the trembles and milk sickness and historically devastated entire settlements. White snakeroot toxins, which differ significantly in plant populations, were initially identified as tremetol which is thought to be mix...
Whole truths vs. half truths – And a search for clarity in long-term water temperature records
There is widespread acceptance among the scientific community that human activities are the primary cause of present day climate change. In contrast, there is significant doubt and dis-interest among the general population. In 2013 Senator Whitehouse (Democrat, Rhode Island) was ...
Prevalence of External Injuries in Small Cetaceans in Aruban Waters, Southern Caribbean
Luksenburg, Jolanda A.
2014-01-01
Aruba, located close to the coasts of Colombia and Venezuela, is one of the most densely populated islands in the Caribbean and supports a wide range of marine-related socio-economic activities. However, little is known about the impacts of human activities on the marine environment. Injuries in marine mammals can be used to examine interactions with human activities and identify potential threats to the survival of populations. The prevalence of external injuries and tooth rake marks were examined in Atlantic spotted dolphin (Stenella frontalis) (n = 179), bottlenose dolphin (Tursiops truncatus) (n = 76) and false killer whale (Pseudorca crassidens) (n = 71) in Aruban waters using photo identification techniques. Eleven injury categories were defined and linked to either human-related activities or natural causes. All injury categories were observed. In total, 18.7% of all individuals had at least one injury. Almost half (41.7%) of the injuries could be attributed to human interactions, of which fishing gear was the most common cause (53.3%) followed by propeller hits (13.3%). Major disfigurements were observed in all three species and could be attributed to interactions with fishing gear. The results of this study indicate that fishing gear and propeller hits may pose threats to small and medium-sized cetaceans in Aruban waters. Thus, long-term monitoring of population trends is warranted. Shark-inflicted bite wounds were observed in Atlantic spotted dolphin and bottlenose dolphin. Bite wounds of cookie cutter sharks (Isistius sp.) were recorded in all three species, and include the first documented record of a cookie cutter shark bite in Atlantic spotted dolphin. This is one of the few studies which investigates the prevalence of injuries in cetaceans in the Caribbean. Further study is necessary to determine to which extent the injuries observed in Aruba affect the health and survival of local populations. PMID:24586473
Resistance in persisting bat populations after white-nose syndrome invasion.
Langwig, Kate E; Hoyt, Joseph R; Parise, Katy L; Frick, Winifred F; Foster, Jeffrey T; Kilpatrick, A Marm
2017-01-19
Increases in anthropogenic movement have led to a rise in pathogen introductions and the emergence of infectious diseases in naive host communities worldwide. We combined empirical data and mathematical models to examine changes in disease dynamics in little brown bat (Myotis lucifugus) populations following the introduction of the emerging fungal pathogen Pseudogymnoascus destructans, which causes the disease white-nose syndrome. We found that infection intensity was much lower in persisting populations than in declining populations where the fungus has recently invaded. Fitted models indicate that this is most consistent with a reduction in the growth rate of the pathogen when fungal loads become high. The data are inconsistent with the evolution of tolerance or an overall reduced pathogen growth rate that might be caused by environmental factors. The existence of resistance in some persisting populations of little brown bats offers a glimmer of hope that a precipitously declining species will persist in the face of this deadly pathogen.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'. © 2016 The Author(s).
Characterization of Greater Middle Eastern genetic variation for enhanced disease gene discovery
Scott, Eric M.; Halees, Anason; Itan, Yuval; Spencer, Emily G.; He, Yupeng; Azab, Mostafa Abdellateef; Gabriel, Stacey B.; Belkadi, Aziz; Boisson, Bertrand; Abel, Laurent; Clark, Andrew G.; Alkuraya, Fowzan S.; Casanova, Jean-Laurent; Gleeson, Joseph G.
2016-01-01
The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Gulf region, North Africa, and Central Asia 1–3, has resulted in an elevated burden of recessive disease4. Here we generated a whole exome GME variome from 1,111 unrelated subjects. We detected substantial diversity from sub-geographies, continental and subregional admixture, several ancient founder populations with little evidence of bottlenecks. Measured consanguinity was an order-of-magnitude above that of other sampled populations, and included an increased burden of runs of homozygosity (ROH), but no evidence for reduced burden of deleterious variation due to classically theorized ‘genetic purging’. Applying this database to unsolved GME recessive conditions reduced the number of potential disease-causing variants by 4–7-fold. These results reveal the variegated GME genetic architecture and support future human genetic discoveries in Mendelian and population genetics. PMID:27428751
NASA Astrophysics Data System (ADS)
Hsiang, Solomon M.; Sobel, Adam H.
2016-06-01
Evidence increasingly suggests that as climate warms, some plant, animal, and human populations may move to preserve their environmental temperature. The distances they must travel to do this depends on how much cooler nearby surfaces temperatures are. Because large-scale atmospheric dynamics constrain surface temperatures to be nearly uniform near the equator, these displacements can grow to extreme distances in the tropics, even under relatively mild warming scenarios. Here we show that in order to preserve their annual mean temperatures, tropical populations would have to travel distances greater than 1000 km over less than a century if global mean temperature rises by 2 °C over the same period. The disproportionately rapid evacuation of the tropics under such a scenario would cause migrants to concentrate in tropical margins and the subtropics, where population densities would increase 300% or more. These results may have critical consequences for ecosystem and human wellbeing in tropical contexts where alternatives to geographic displacement are limited.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rutqvist, Jonny; Cappa, Frédéric; Rinaldi, Antonio P.
In this paper, we present model simulations of ground motions caused by CO 2 -injection-induced fault reactivation and analyze the results in terms of the potential for damage to ground surface structures and nuisance to the local human population. It is an integrated analysis from cause to consequence, including the whole chain of processes starting from earthquake inception in the subsurface, wave propagation toward the ground surface, and assessment of the consequences of ground vibration. For a small magnitude (M w =3) event at a hypocenter depth of about 1000m, we first used the simulated ground-motion wave train in anmore » inverse analysis to estimate source parameters (moment magnitude, rupture dimensions and stress drop), achieving good agreement and thereby verifying the modeling of the chain of processes from earthquake inception to ground vibration. We then analyzed the ground vibration results in terms of peak ground acceleration (PGA), peak ground velocity (PGV) and frequency content, with comparison to U.S. Geological Survey's instrumental intensity scales for earthquakes and the U.S. Bureau of Mines' vibration criteria for cosmetic damage to buildings, as well as human-perception vibration limits. Our results confirm the appropriateness of using PGV (rather than PGA) and frequency for the evaluation of potential ground-vibration effects on structures and humans from shallow injection-induced seismic events. For the considered synthetic M w =3 event, our analysis showed that the short duration, high frequency ground motion may not cause any significant damage to surface structures, but would certainly be felt by the local population.« less
[Heatwaves and population die off in the Voronezh city].
Mekhant'ev, I I; Pichuzhkina, N M; Masaĭlova, L A
2013-01-01
Climatic factor is most important condition for the formation of public health. Attention to it has increased recently against the background of global and regional climate change. The aim of the study was to investigate the effect of air temperature on population die off in the Voronezh city in the period of fire-related emergencies. Assessment of cause-and-effect relationships between the air temperature and daily death cases s was performed with the help of the method of time series. Correlation analysis showed a statistically significant positive relationship between air temperature and population die off from all causes and from diseases of the circulatory system with a lag of 0, 1, 2, 3 days; respiratory diseases - with a lag of 3 days. With the gain in air temperature by one degree the number of deaths increases by 3%. The results were used in adopt management decisions on minimization risks and potential negative effects on human health.
Acuna-Soto, Rodolfo; Stahle, David W; Therrell, Matthew D; Gomez Chavez, Sergio; Cleaveland, Malcolm K
2005-01-01
The classical period in Mexico (AD 250-750) was an era of splendor. The city of Teotihuacan was one of the largest and most sophisticated human conglomerates of the pre-industrial world. The Mayan civilization in southeastern Mexico and the Yucatan peninsula reached an impressive degree of development at the same time. This time of prosperity came to an end during the Terminal Classic Period (AD 750-950) a time of massive population loss throughout Mesoamerica. A second episode of massive depopulation in the same area was experienced during the sixteenth century when, in less than one century, between 80% and 90% of the entire indigenous population was lost. The 16th century depopulation of Mexico constitutes one of the worst demographic catastrophes in human history. Although newly imported European and African diseases caused high mortality among the native population, the major 16th century population losses were caused by a series of epidemics of a hemorrhagic fever called Cocoliztli, a highly lethal disease unknown to both Aztec and European physicians during the colonial era. The cocoliztli epidemics occurred during the 16th century megadrought, when severe drought extended at times from central Mexico to the boreal forest of Canada, and from the Pacific to the Atlantic coast. The collapse of the cultures of the Classic Period seems also to have occurred during a time of severe drought. Tree ring and lake sediment records indicate that some of the most severe and prolonged droughts to impact North America-Mesoamerica in the past 1000-4000 years occurred between AD 650 and 1000, particularly during the 8th and 9th centuries, a period of time that coincides with the Terminal Classic Period. Based on the similarities of the climatic (severe drought) and demographic (massive population loss) events in Mesoamerica during the sixteenth century, we propose that drought-associated epidemics of hemorrhagic fever may have contributed to the massive population loss during the Terminal Classic Period.
Candidate genes for idiopathic epilepsy in four dog breeds.
Ekenstedt, Kari J; Patterson, Edward E; Minor, Katie M; Mickelson, James R
2011-04-25
Idiopathic epilepsy (IE) is a naturally occurring and significant seizure disorder affecting all dog breeds. Because dog breeds are genetically isolated populations, it is possible that IE is attributable to common founders and is genetically homogenous within breeds. In humans, a number of mutations, the majority of which are genes encoding ion channels, neurotransmitters, or their regulatory subunits, have been discovered to cause rare, specific types of IE. It was hypothesized that there are simple genetic bases for IE in some purebred dog breeds, specifically in Vizslas, English Springer Spaniels (ESS), Greater Swiss Mountain Dogs (GSMD), and Beagles, and that the gene(s) responsible may, in some cases, be the same as those already discovered in humans. Candidate genes known to be involved in human epilepsy, along with selected additional genes in the same gene families that are involved in murine epilepsy or are expressed in neural tissue, were examined in populations of affected and unaffected dogs. Microsatellite markers in close proximity to each candidate gene were genotyped and subjected to two-point linkage in Vizslas, and association analysis in ESS, GSMD and Beagles. Most of these candidate genes were not significantly associated with IE in these four dog breeds, while a few genes remained inconclusive. Other genes not included in this study may still be causing monogenic IE in these breeds or, like many cases of human IE, the disease in dogs may be likewise polygenic.
Epidemiological Evidence That Garden Birds Are a Source of Human Salmonellosis in England and Wales
Lawson, Becki; de Pinna, Elizabeth; Horton, Robert A.; Macgregor, Shaheed K.; John, Shinto K.; Chantrey, Julian; Duff, J. Paul; Kirkwood, James K.; Simpson, Victor R.; Robinson, Robert A.; Wain, John; Cunningham, Andrew A.
2014-01-01
The importance of wild bird populations as a reservoir of zoonotic pathogens is well established. Salmonellosis is a frequently diagnosed infectious cause of mortality of garden birds in England and Wales, predominantly caused by Salmonella enterica subspecies enterica serovar Typhimurium definitive phage types 40, 56(v) and 160. In Britain, these phage types are considered highly host-adapted with a high degree of genetic similarity amongst isolates, and in some instances are clonal. Pulsed field gel electrophoresis, however, demonstrated minimal variation amongst matched DT40 and DT56(v) isolates derived from passerine and human incidents of salmonellosis across England in 2000–2007. Also, during the period 1993–2012, similar temporal and spatial trends of infection with these S. Typhimurium phage types occurred in both the British garden bird and human populations; 1.6% of all S. Typhimurium (0.2% of all Salmonella) isolates from humans in England and Wales over the period 2000–2010. These findings support the hypothesis that garden birds act as the primary reservoir of infection for these zoonotic bacteria. Most passerine salmonellosis outbreaks identified occurred at and around feeding stations, which are likely sites of public exposure to sick or dead garden birds and their faeces. We, therefore, advise the public to practise routine personal hygiene measures when feeding wild birds and especially when handling sick wild birds. PMID:24586464
Human behavioral contributions to climate change: psychological and contextual drivers.
Swim, Janet K; Clayton, Susan; Howard, George S
2011-01-01
We are facing rapid changes in the global climate, and these changes are attributable to human behavior. Humans produce this global impact through our use of natural resources, multiplied by the vast increase in population seen in the past 50 to 100 years. Our goal in this article is to examine the underlying psychosocial causes of human impact, primarily through patterns of reproduction and consumption. We identify and distinguish individual, societal, and behavioral predictors of environmental impact. Relevant research in these areas (as well as areas that would be aided by greater attention by psychologists) are reviewed. We conclude by highlighting ethical issues that emerge when considering how to address human behavioral contributions to climate change.
A mathematical model of Chagas disease transmission
NASA Astrophysics Data System (ADS)
Hidayat, Dayat; Nugraha, Edwin Setiawan; Nuraini, Nuning
2018-03-01
Chagas disease is a parasitic infection caused by protozoan Trypanosoma cruzi which is transmitted to human by insects of the subfamily Triatominae, including Rhodnius prolixus. This disease is a major problem in several countries of Latin America. A mathematical model of Chagas disease with separate vector reservoir and a neighboring human resident is constructed. The basic reproductive ratio is obtained and stability analysis of the equilibria is shown. We also performed sensitivity populations dynamics of infected humans and infected insects based on migration rate, carrying capacity, and infection rate parameters. Our findings showed that the dynamics of the infected human and insect is mostly affected by carrying capacity insect in the settlement.
Human health effects of ozone reduction
NASA Technical Reports Server (NTRS)
1975-01-01
Modification of the stratosphere, such as a reduction in its equilibrium ozone content, could produce direct and indirect effects on human health. The direct hazard to humans would be caused by an increase in the cumulative amount of UV radiation reaching the earth's surface in the range of 285 to 340 nm, encompassing the UV-B or erythemal wavelength region of 280 to 320 nm. Exposing the susceptible human population to an increased total UV dosage of shorter wavelengths could increase skin cancer incidence. Although effects would be delayed by decades, for each 1% decrease in ozone the expected increase in skin cancer incidence would be on the order of 2%.
Traffic noise causes physiological stress and impairs breeding migration behaviour in frogs
Tennessen, Jennifer B.; Parks, Susan E.; Langkilde, Tracy
2014-01-01
Human-generated noise has profoundly changed natural soundscapes in aquatic and terrestrial ecosystems, imposing novel pressures on ecological processes. Despite interest in identifying the ecological consequences of these altered soundscapes, little is known about the sublethal impacts on wildlife population health and individual fitness. We present evidence that noise induces a physiological stress response in an amphibian and impairs mate attraction in the natural environment. Traffic noise increased levels of a stress-relevant glucocorticoid hormone (corticosterone) in female wood frogs (Lithobates sylvaticus) and impaired female travel towards a male breeding chorus in the field, providing insight into the sublethal consequences of acoustic habitat loss. Given that prolonged elevated levels of corticosterone can have deleterious consequences on survival and reproduction and that impaired mate attraction can impact population persistence, our results suggest a novel pathway by which human activities may be imposing population-level impacts on globally declining amphibians. PMID:27293653
Traffic noise causes physiological stress and impairs breeding migration behaviour in frogs.
Tennessen, Jennifer B; Parks, Susan E; Langkilde, Tracy
2014-01-01
Human-generated noise has profoundly changed natural soundscapes in aquatic and terrestrial ecosystems, imposing novel pressures on ecological processes. Despite interest in identifying the ecological consequences of these altered soundscapes, little is known about the sublethal impacts on wildlife population health and individual fitness. We present evidence that noise induces a physiological stress response in an amphibian and impairs mate attraction in the natural environment. Traffic noise increased levels of a stress-relevant glucocorticoid hormone (corticosterone) in female wood frogs (Lithobates sylvaticus) and impaired female travel towards a male breeding chorus in the field, providing insight into the sublethal consequences of acoustic habitat loss. Given that prolonged elevated levels of corticosterone can have deleterious consequences on survival and reproduction and that impaired mate attraction can impact population persistence, our results suggest a novel pathway by which human activities may be imposing population-level impacts on globally declining amphibians.
Salmonella chronic carriage: epidemiology, diagnosis and gallbladder persistence
Gunn, John S.; Marshall, Joanna M.; Baker, Stephen; Dongol, Sabina; Charles, Richelle C.; Ryan, Edward T.
2014-01-01
Typhoid (enteric fever) remains a major cause of morbidity and mortality worldwide, causing over 21 million new infections annually, with the majority of deaths occurring in young children. As typhoid fever-causing Salmonella have no known environmental reservoir, the chronic, asymptomatic carrier state is thought to be a key feature of continued maintenance of the bacterium within human populations. In spite of the importance of this disease to public health, our understanding of the molecular mechanisms that catalyze carriage, as well as our ability to reliably identify and treat the Salmonella carrier state, have only recently begun to advance. PMID:25065707
Rutqvist, Jonny; Cappa, Frédéric; Rinaldi, Antonio P.; ...
2014-05-01
In this paper, we present model simulations of ground motions caused by CO 2 -injection-induced fault reactivation and analyze the results in terms of the potential for damage to ground surface structures and nuisance to the local human population. It is an integrated analysis from cause to consequence, including the whole chain of processes starting from earthquake inception in the subsurface, wave propagation toward the ground surface, and assessment of the consequences of ground vibration. For a small magnitude (M w =3) event at a hypocenter depth of about 1000m, we first used the simulated ground-motion wave train in anmore » inverse analysis to estimate source parameters (moment magnitude, rupture dimensions and stress drop), achieving good agreement and thereby verifying the modeling of the chain of processes from earthquake inception to ground vibration. We then analyzed the ground vibration results in terms of peak ground acceleration (PGA), peak ground velocity (PGV) and frequency content, with comparison to U.S. Geological Survey's instrumental intensity scales for earthquakes and the U.S. Bureau of Mines' vibration criteria for cosmetic damage to buildings, as well as human-perception vibration limits. Our results confirm the appropriateness of using PGV (rather than PGA) and frequency for the evaluation of potential ground-vibration effects on structures and humans from shallow injection-induced seismic events. For the considered synthetic M w =3 event, our analysis showed that the short duration, high frequency ground motion may not cause any significant damage to surface structures, but would certainly be felt by the local population.« less
The Mobile Element Locator Tool (MELT): population-scale mobile element discovery and biology
Gardner, Eugene J.; Lam, Vincent K.; Harris, Daniel N.; Chuang, Nelson T.; Scott, Emma C.; Pittard, W. Stephen; Mills, Ryan E.; Devine, Scott E.
2017-01-01
Mobile element insertions (MEIs) represent ∼25% of all structural variants in human genomes. Moreover, when they disrupt genes, MEIs can influence human traits and diseases. Therefore, MEIs should be fully discovered along with other forms of genetic variation in whole genome sequencing (WGS) projects involving population genetics, human diseases, and clinical genomics. Here, we describe the Mobile Element Locator Tool (MELT), which was developed as part of the 1000 Genomes Project to perform MEI discovery on a population scale. Using both Illumina WGS data and simulations, we demonstrate that MELT outperforms existing MEI discovery tools in terms of speed, scalability, specificity, and sensitivity, while also detecting a broader spectrum of MEI-associated features. Several run modes were developed to perform MEI discovery on local and cloud systems. In addition to using MELT to discover MEIs in modern humans as part of the 1000 Genomes Project, we also used it to discover MEIs in chimpanzees and ancient (Neanderthal and Denisovan) hominids. We detected diverse patterns of MEI stratification across these populations that likely were caused by (1) diverse rates of MEI production from source elements, (2) diverse patterns of MEI inheritance, and (3) the introgression of ancient MEIs into modern human genomes. Overall, our study provides the most comprehensive map of MEIs to date spanning chimpanzees, ancient hominids, and modern humans and reveals new aspects of MEI biology in these lineages. We also demonstrate that MELT is a robust platform for MEI discovery and analysis in a variety of experimental settings. PMID:28855259
Human influenza viruses and CD8(+) T cell responses.
Grant, Emma J; Quiñones-Parra, Sergio M; Clemens, E Bridie; Kedzierska, Katherine
2016-02-01
Influenza A viruses (IAVs) cause significant morbidity and mortality worldwide, despite new strain-specific vaccines being available annually. As IAV-specific CD8(+) T cells promote viral control in the absence of neutralizing antibodies, and can mediate cross-reactive immunity toward distinct IAVs to drive rapid recovery from both mild and severe influenza disease, there is great interest in developing a universal T cell vaccine. However, despite detailed studies in mouse models of influenza virus infection, there is still a paucity of data on human epitope-specific CD8(+) T cell responses to IAVs. This review focuses on our current understanding of human CD8(+) T cell immunity against distinct IAVs and discusses the possibility of achieving a CD8(+) T cell mediated-vaccine that protects against multiple, distinct IAV strains across diverse human populations. We also review the importance of CD8(+) T cell immunity in individuals highly susceptible to severe influenza infection, including those hospitalised with influenza, the elderly and Indigenous populations. Copyright © 2016 Elsevier B.V. All rights reserved.
2013-01-01
The incidence of anal cancer is increasing in the general population and especially in high-risk groups. A total of 90% of anal cancers are caused by human papilloma virus (HPV) infection of the anal canal. Similar to cervical cancer, anal cancer progresses through a predictable series of premalignant stages before resulting in invasive cancer; this process begins with persistent HPV infection. The HPV vaccine represents a promising strategy to combat the increasing incidence of anal cancer. Human Immunodeficiency Virus (HIV) predisposes people to persistent HPV infection, dysplasia, and subsequent anal cancer. Patients infected with HIV should be targeted for vaccination against HPV. There are difficulties in targeting this population, the most notable being that the optimal age for vaccination is prior to identification with any high-risk groups. Universal vaccination against HPV represents the best strategy to achieve maximum protection against anal cancer in high-risk groups. PMID:24757517
NASA Astrophysics Data System (ADS)
Emslie, Steven D.; Brasso, Rebecka; Patterson, William P.; Carlos Valera, António; McKenzie, Ashley; Maria Silva, Ana; Gleason, James D.; Blum, Joel D.
2015-10-01
Cinnabar is a natural mercury sulfide (HgS) mineral of volcanic or hydrothermal origin that is found worldwide. It has been mined prehistorically and historically in China, Japan, Europe, and the Americas to extract metallic mercury (Hg0) for use in metallurgy, as a medicinal, a preservative, and as a red pigment for body paint and ceramics. Processing cinnabar via combustion releases Hg0 vapor that can be toxic if inhaled. Mercury from cinnabar can also be absorbed through the gut and skin, where it can accumulate in organs and bone. Here, we report moderate to high levels of total mercury (THg) in human bone from three Late Neolithic/Chalcolithic (5400-4100 B.P.) sites in southern Portugal that were likely caused by cultural use of cinnabar. We use light stable isotope and Hg stable isotope tracking to test three hypotheses on the origin of mercury in this prehistoric human bone. We traced Hg in two individuals to cinnabar deposits near Almadén, Spain, and conclude that use of this mineral likely caused mild to severe mercury poisoning in the prehistoric population. Our methods have applications to bioarchaeological investigations worldwide, and for tracking trade routes and mobility of prehistoric populations where cinnabar use is documented.
Iron does not cause arrhythmias in the guinea pig model of transfusional iron overload.
Kaiser, Lana; Davis, John; Patterson, Jon; Boyd, Ryan F; Olivier, N Bari; Bohart, George; Schwartz, Kenneth A
2007-08-01
Cardiac events, including heart failure and arrhythmias, are the leading cause of death in patients with beta thalassemia. Although cardiac arrhythmias in humans are believed to result from iron overload, excluding confounding factors in the human population is difficult. The goal of the current study was to determine whether cardiac arrhythmias occurred in the guinea pig model of secondary iron overload. Electrocardiograms were recorded by using surgically implanted telemetry devices in guinea pigs loaded intraperitoneally with iron dextran (test animals) or dextran alone (controls). Loading occurred over approximately 6 wk. Electrocardiograms were recorded for 1 wk prior to loading, throughout loading, and for approximately 4 wk after loading was complete. Cardiac and liver iron concentrations were significantly increased in the iron-loaded animals compared with controls and were in the range of those reported for humans with thalassemia. Arrhythmias were rare in both iron-loaded and control guinea pigs. No life-threatening arrhythmias were detected in either group. These data suggest that iron alone may be insufficient to cause cardiac arrhythmias in the iron-loaded guinea pig model and that arrhythmias detected in human patients with iron overload may be the result of a complex interplay of factors.
Hydrophobicity and biofilm formation of lipophilic skin corynebacteria.
Kwaszewska, Anna K; Brewczyńska, Anna; Szewczyk, Eligia M
2006-01-01
Lipophilic corynebacteria isolated as natural flora of human skin were examined. Among 119 assayed strains 94% presented a hydrophobic cell surface and 75.6% were able to form biofilms. These attributes, as well as aggregation in liquid media, were statistically connected with each other and promote the developing of biofilms on solid surfaces. This was characteristic of all the lipophilic Corynebacterium species found on human skin that were examined in this study. C. jeikeium and CDC group G2 strains dominated in this population, and they could be responsible for investigated features in the whole lipophilic skin bacterial population. These two groups are the most common coryneform bacteria isolated from nosocomial infections and these attributes most likely promote them to cause opportunistic infections.
Aoki, Kenichi
2018-04-05
In apparent contradiction to the theoretically predicted effect of population size on the quality/quantity of material culture, statistical analyses on ethnographic hunter-gatherers have shown an absence of correlation between population size and toolkit size. This has sparked a heated, if sometimes tangential, debate as to the usefulness of the theoretical models and as to what modes of cultural transmission humans are capable of and hunter-gatherers rely on. I review the directly relevant theoretical literature and argue that much of the confusion is caused by a mismatch between the theoretical variable and the empirical observable. I then confirm that a model incorporating the appropriate variable does predict a positive association between population size and toolkit size for random oblique, vertical, best-of- K , conformist, anticonformist, success bias and one-to-many cultural transmission, with the caveat that for all populations sampled, the population size has remained constant and toolkit size has reached the equilibrium for this population size. Finally, I suggest three theoretical scenarios, two of them involving variable population size, that would attenuate or eliminate this association and hence help to explain the empirical absence of correlation.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'. © 2018 The Author(s).
Trends in scale and shape of survival curves.
Weon, Byung Mook; Je, Jung Ho
2012-01-01
The ageing of the population is an issue in wealthy countries worldwide because of increasing costs for health care and welfare. Survival curves taken from demographic life tables may help shed light on the hypotheses that humans are living longer and that human populations are growing older. We describe a methodology that enables us to obtain separate measurements of scale and shape variances in survival curves. Specifically, 'living longer' is associated with the scale variance of survival curves, whereas 'growing older' is associated with the shape variance. We show how the scale and shape of survival curves have changed over time during recent decades, based on period and cohort female life tables for selected wealthy countries. Our methodology will be useful for performing better tracking of ageing statistics and it is possible that this methodology can help identify the causes of current trends in human ageing.
Zak, Yana; Pehek, Ellen
2013-01-01
Urbanization is a major cause of amphibian decline. Stream-dwelling plethodontid salamanders are particularly susceptible to urbanization due to declining water quality and hydrological changes, but few studies have examined these taxa in cities. The northern dusky salamander (Desmognathus fuscus) was once common in the New York City metropolitan area, but has substantially declined throughout the region in recent decades. We used five tetranucleotide microsatellite loci to examine population differentiation, genetic variation, and bottlenecks among five remnant urban populations of dusky salamanders in NYC. These genetic measures provide information on isolation, prevalence of inbreeding, long-term prospects for population persistence, and potential for evolutionary responses to future environmental change. All populations were genetically differentiated from each other, and the most isolated populations in Manhattan have maintained very little genetic variation (i.e. <20% heterozygosity). A majority of the populations also exhibited evidence of genetic bottlenecks. These findings contrast with published estimates of high genetic variation within and lack of structure between populations of other desmognathine salamanders sampled over similar or larger spatial scales. Declines in genetic variation likely resulted from population extirpations and the degradation of stream and terrestrial paths for dispersal in NYC. Loss of genetic variability in populations isolated by human development may be an underappreciated cause and/or consequence of the decline of this species in urbanized areas of the northeast USA. PMID:23646283
HPV: diagnosis, prevention, and treatment.
Hathaway, Jon K
2012-09-01
Human papilloma virus (HPV) is the most common sexually transmitted disease in the world. Almost 80% of the world's population is exposed by the age of 50. HPV can cause oropharyngeal, genital, and anal cancers. It also causes genital warts. There is no cure for HPV but vaccines are available to prevent infection by the most common HPV viruses; unfortunately, usage is low. Most people will clear HPV spontaneously. Those who do not are at high risk for developing malignancy. Treatment mainstays are destruction and excision of the lesions.
The failure of academic epidemiology: witness for the prosecution.
Shy, C M
1997-03-15
Academic epidemiology has failed to develop the scientific methods and the knowledge base to support the fundamental public health mission of preventing disease and promoting health through organized community efforts. As a basic science of public health, epidemiology should attempt to understand health and disease from a community and ecologic perspective as a consequence of how society is organized and behaves, what impact social and economic forces have on disease incidence rates, and what community actions will be effective in altering incidence rates. However, as taught in most textbooks and as widely practiced by academicians, epidemiology has become a biomedical discipline focused on the distribution and determinants of disease in groups of individuals who happen to have some common characteristics, exposures, or diseases. The ecology of human health has not been addressed, and the societal context in which disease occurs has been either disregarded or deliberately abstracted from consideration. By essentially assuming that risk factors for disease in individuals can be summed to understand the causes of disease in populations, academic epidemiology has limited itself to a narrow biomedical perspective, thereby committing the bio-medical fallacy of inferring that disease in populations can be understood by studying risk factors for disease in individuals. Epidemiology should be redefined as a study of the distribution and societal determinants of the health status of populations. This definition provides a stronger link to be the primary mission of public health and places an appropriate emphasis on the social, economic, environmental, and cultural determinants of population health. Epidemiology must cross the boundaries of other population sciences and add to its scope a macro-epidemiology, a study of causes from a truly population perspective, considering health and disease within the context of the total human environment.
Turvey, Samuel T.; Crees, Jennifer J.; Di Fonzo, Martina M. I.
2015-01-01
Extinction events typically represent extended processes of decline that cannot be reconstructed using short-term studies. Long-term archives are necessary to determine past baselines and the extent of human-caused biodiversity change, but the capacity of historical datasets to provide predictive power for conservation must be assessed within a robust analytical framework. Local Chinese gazetteers represent a more than 400-year country-level dataset containing abundant information on past environmental conditions and include extensive records of gibbons, which have a restricted present-day distribution but formerly occurred across much of China. Gibbons show pre-twentieth century range contraction, with significant fragmentation by the mid-eighteenth century and population loss escalating in the late nineteenth century. Isolated gibbon populations persisted for about 40 years before local extinction. Populations persisted for longer at higher elevations, and disappeared earlier from northern and eastern regions, with the biogeography of population loss consistent with the contagion model of range collapse in response to human demographic expansion spreading directionally across China. The long-term Chinese historical record can track extinction events and human interactions with the environment across much longer timescales than are usually addressed in ecology, contributing novel baselines for conservation and an increased understanding of extinction dynamics and species vulnerability or resilience to human pressures. PMID:26246553
Turvey, Samuel T; Crees, Jennifer J; Di Fonzo, Martina M I
2015-08-22
Extinction events typically represent extended processes of decline that cannot be reconstructed using short-term studies. Long-term archives are necessary to determine past baselines and the extent of human-caused biodiversity change, but the capacity of historical datasets to provide predictive power for conservation must be assessed within a robust analytical framework. Local Chinese gazetteers represent a more than 400-year country-level dataset containing abundant information on past environmental conditions and include extensive records of gibbons, which have a restricted present-day distribution but formerly occurred across much of China. Gibbons show pre-twentieth century range contraction, with significant fragmentation by the mid-eighteenth century and population loss escalating in the late nineteenth century. Isolated gibbon populations persisted for about 40 years before local extinction. Populations persisted for longer at higher elevations, and disappeared earlier from northern and eastern regions, with the biogeography of population loss consistent with the contagion model of range collapse in response to human demographic expansion spreading directionally across China. The long-term Chinese historical record can track extinction events and human interactions with the environment across much longer timescales than are usually addressed in ecology, contributing novel baselines for conservation and an increased understanding of extinction dynamics and species vulnerability or resilience to human pressures. © 2015 The Authors.
Trends in mortality and biological stress in a medieval polish urban population.
Betsinger, Tracy K; DeWitte, Sharon
2017-12-01
Urbanization in pre-modern populations may have had a variety of consequences related to population crowding. However, research on the effects of urbanization have provided inconsistent results regarding the biological impact of this transition on human populations. The purpose of this study is to test the hypothesis that urbanization caused an increase in overall biological stress in a medieval (10th-13th centuries AD) Polish population. A human skeletal sample (n=164) was examined for the presence of porotic hyperostosis, cribra orbitalia, linear enamel hypoplasia, periosteal reaction, and specific infectious diseases. Prevalence rates were compared among three temporal samples: initial urbanization, early urbanization, and later urbanization. Results indicate no significant trends for any of the pathological conditions. Cox proportional hazards analyses, however, revealed a significant increase in the risk of death over time, which supports the hypothesis. These results reflect the necessity of using multiple analyses to address bioarchaeological questions. The lack of significant results from skeletal indicators may be due to an earlier urbanization trend in the population. This study illustrates that the association of urbanization with elevated biological stress is complicated and dependent on various factors, including culture and time period. Copyright © 2017 Elsevier Inc. All rights reserved.
Temporal scaling behavior of forest and urban fires
NASA Astrophysics Data System (ADS)
Wang, J.; Song, W.; Zheng, H.; Telesca, L.
2009-04-01
It has been found that many natural systems are characterized by scaling behavior. In such systems natural factors dominate the event dynamics. Forest fires in different countries have been found to exhibit frequency-size power law over many orders of magnitude and with similar value of parameters. But in countries with high population density such as China and Japan, more than 95% of the forest fire disasters are caused by human activities. Furthermore, with the development of society, the wildland-urban interface (WUI) area is becoming more and more populated, and the forest fire is much connected with urban fire. Therefore exploring the scaling behavior of fires dominated by human-related factors is very challenging. The present paper explores the temporal scaling behavior of forest fires and urban fires in Japan with mathematical methods. Two factors, Allan factor (AF) and Fano factor (FF) are used to investigate time-scaling of fire systems. It is found that the FF for both forest fires and urban fires increases linearly in log-log scales, and this indicates that it behaves as a power-law for all the investigated timescales. From the AF plot a 7 days cycle is found, which indicates a weekly cycle. This may be caused by human activities which has a weekly periodicity because on weekends people usually have more outdoor activities, which may cause more hidden trouble of fire disasters. Our findings point out that although the human factors are the main cause, both the forest fires and urban fires exhibit time-scaling behavior. At the same time, the scaling exponents for urban fires are larger than forest fires, signifying a more intense clustering. The reason may be that fires are affected not only by weather condition, but also by human activities, which play a more important role for urban fires than forest fires and have a power law distribution and scaling behavior. Then some work is done to the relative humidity. Similar distribution law characterizes the relative humidity. The AF plot and FF plot of relative humidity validate the existence of a strong link between weather and fires, and it is very likely that the daily humidity cycle determines the daily fire periodicity.
Little, Deirdre Therese; Ward, Harvey Rodrick Grenville
2012-09-30
Premature ovarian failure in a well adolescent is a rare event. Its occurrence raises important questions about causation, which may signal other systemic concerns. This patient presented with amenorrhoea after identifying a change from her regular cycle to irregular and scant periods following vaccinations against human papillomavirus. She declined the oral contraceptives initially prescribed for amenorrhoea. The diagnostic tasks were to determine the reason for her secondary amenorrhoea and then to investigate for possible causes of the premature ovarian failure identified. Although the cause is unknown in 90% of cases, the remaining chief identifiable causes of this condition were excluded. Premature ovarian failure was then notified as a possible adverse event following this vaccination. The young woman was counselled regarding preservation of bone density, reproductive implications and relevant follow-up. This event could hold potential implications for population health and prompts further inquiry.
Progressive Multifocal Leukoencephalopathy: Endemic Viruses and Lethal Brain Disease.
Haley, Sheila A; Atwood, Walter J
2017-09-29
In 1971, the first human polyomavirus was isolated from the brain of a patient who died from a rapidly progressing demyelinating disease known as progressive multifocal leukoencephalopathy. The virus was named JC virus after the initials of the patient. In that same year a second human polyomavirus was discovered in the urine of a kidney transplant patient and named BK virus. In the intervening years it became clear that both viruses were widespread in the human population but only rarely caused disease. The past decade has witnessed the discovery of eleven new human polyomaviruses, two of which cause unusual and rare cancers. We present an overview of the history of these viruses and the evolution of JC polyomavirus-induced progressive multifocal leukoencephalopathy over three different epochs. We review what is currently known about JC polyomavirus, what is suspected, and what remains to be done to understand the biology of how this mostly harmless endemic virus gives rise to lethal disease.
Santos, Nuno; Nhambir, André; Inlamea, Osvaldo; Hattendorf, Jan; Källenius, Gunilla; Zinsstag, Jakob; Correia-Neves, Margarida
2014-01-01
Background Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is an infectious disease of cattle that also affects other domestic animals, free-ranging and farmed wildlife, and also humans. In Mozambique, scattered surveys have reported a wide variation of bTB prevalence rates in cattle from different regions. Due to direct economic repercussions on livestock and indirect consequences for human health and wildlife, knowing the prevalence rates of the disease is essential to define an effective control strategy. Methodology/Principal findings A cross-sectional study was conducted in Govuro district to determine bTB prevalence in cattle and identify associated risk factors. A representative sample of the cattle population was defined, stratified by livestock areas (n = 14). A total of 1136 cattle from 289 farmers were tested using the single comparative intradermal tuberculin test. The overall apparent prevalence was estimated at 39.6% (95% CI 36.8–42.5) using a diagnostic threshold cut-off according to the World Organization for Animal Health. bTB reactors were found in 13 livestock areas, with prevalence rates ranging from 8.1 to 65.8%. Age was the main risk factor; animals older than 4 years were more likely to be positive reactors (OR = 3.2, 95% CI: 2.2–4.7). Landim local breed showed a lower prevalence than crossbred animals (Landim × Brahman) (OR = 0.6, 95% CI: 0.4–0.8). Conclusions/Significance The findings reveal an urgent need for intervention with effective, area-based, control measures in order to reduce bTB prevalence and prevent its spread to the human population. In addition to the high prevalence, population habits in Govuro, particularly the consumption of raw milk, clearly may potentiate the transmission to humans. Thus, further studies on human tuberculosis and the molecular characterization of the predominant strain lineages that cause bTB in cattle and humans are urgently required to evaluate the impact on human health in the region. PMID:24632593
The role of one health in wildlife conservation: a challenge and opportunity.
Buttke, Danielle E; Decker, Daniel J; Wild, Margaret A
2015-01-01
Numerous emerging infectious diseases (EIDs) have arisen from or been identified in wildlife, with health implications for both humans and wildlife. In the practice of wildlife conservation, to date most attention has focused on the threat EIDs pose to biodiversity and wildlife population viability. In the popular media and public eye, however, wildlife is often only portrayed as the cause of EIDs and resultant human health impacts. There is little coverage on the roles of human-induced habitat destruction or wildlife population stress in EID spread, nor the negative impacts of disease on wildlife. Here, we focus on a little-studied and seldom discussed concern: how real and perceived risks of wildlife-associated diseases for human and companion animal health might erode public support for wildlife conservation. We believe that wildlife-associated EIDs and public perceptions of these risks are among the most important threats to wildlife conservation. In light of this concern, we explore the challenges and opportunities for addressing this situation in a One Health context that emphasizes the interdisciplinary collaboration and the inextricable nature of human and animal health and disease.
Dust, Climate, and Human Health
NASA Technical Reports Server (NTRS)
Maynard, Nancy G.
2003-01-01
Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. Ths paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.
Dust, Climate, and Human Health
NASA Technical Reports Server (NTRS)
Maynard, Nancy G.
2003-01-01
Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.
Rutqvist, Jonny; Cappa, Frederic; Rinaldi, Antonio P.; ...
2014-12-31
We summarize recent modeling studies of injection-induced fault reactivation, seismicity, and its potential impact on surface structures and nuisance to the local human population. We used coupled multiphase fluid flow and geomechanical numerical modeling, dynamic wave propagation modeling, seismology theories, and empirical vibration criteria from mining and construction industries. We first simulated injection-induced fault reactivation, including dynamic fault slip, seismic source, wave propagation, and ground vibrations. From co-seismic average shear displacement and rupture area, we determined the moment magnitude to about M w = 3 for an injection-induced fault reactivation at a depth of about 1000 m. We then analyzedmore » the ground vibration results in terms of peak ground acceleration (PGA), peak ground velocity (PGV), and frequency content, with comparison to the U.S. Bureau of Mines’ vibration criteria for cosmetic damage to buildings, as well as human-perception vibration limits. For the considered synthetic M w = 3 event, our analysis showed that the short duration, high frequency ground motion may not cause any significant damage to surface structures, and would not cause, in this particular case, upward CO 2 leakage, but would certainly be felt by the local population.« less
Dust, Climate, and Human Health
NASA Astrophysics Data System (ADS)
Maynard, N. G.
2003-12-01
Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health
Freitas, Ana R.; Novais, Carla; Ruiz-Garbajosa, Patricia; Coque, Teresa M.; Peixe, Luísa
2009-01-01
The population structure of 56 Enterococcus faecium isolates selected from a collection of enterococci from humans, animals, and the environment in Portugal (1997 to 2007) was analyzed by multilocus sequence typing. We identified 41 sequence types clustering into CC17, CC5, CC9, CC22 and CC94, all clonal lineages comprising isolates from different hosts. Our findings highlight the role of community-associated hosts as reservoirs of enterococci able to cause human infections. PMID:19447948
The human footprint in the west: a large-scale analysis of anthropogenic impacts.
Leu, M.; Hanser, S.E.; Knick, S.T.
2008-01-01
Anthropogenic features such as urbanization, roads, and power lines, are increasing in western United States landscapes in response to rapidly growing human populations. However, their spatial effects have not been evaluated. Our goal was to model the human footprint across the western United States. We first delineated the actual area occupied by anthropogenic features, the physical effect area. Next, we developed the human footprint model based on the ecological effect area, the zone influenced by features beyond their physical presence, by combining seven input models: three models quantified top-down anthropogenic influences of synanthropic predators (avian predators, domestic dog and cat presence risk), and four models quantified bottom-up anthropogenic influences on habitat (invasion of exotic plants, human-caused fires, energy extraction, and anthropogenic wildland fragmentation). Using independent bird population data, we found bird abundance of four synanthropic species to correlate positively with human footprint intensity and negatively for three of the six species influenced by habitat fragmentation. We then evaluated the extent of the human footprint in relation to terrestrial (ecoregions) and aquatic systems (major rivers and lakes), regional management and conservation status, physical environment, and temporal changes in human actions. The physical effect area of anthropogenic features covered 13% of the western United States with agricultural land (9.8%) being most dominant. High-intensity human footprint areas (class 8–10) overlapped highly productive low-elevation private landholdings and covered 7% of the western United States compared to 48% for low-intensity areas (class 1–3), which were confined to low-productivity high-elevation federal landholdings. Areas within 1 km of rivers were more affected by the human footprint compared to lakes. Percentage human population growth was higher in low-intensity human footprint areas. The disproportional regional effects of the human footprint on landscapes in the western United States create a challenge to management of ecosystems and wildlife populations. Using footprint models, managers can plan land use actions, develop restoration scenarios, and identify areas of high conservation value at local landscapes within a regional context. Moreover, human footprint models serve as a tool to stratify landscapes for studies investigating floral and faunal response to human disturbance intensity gradients.
A SURVEY OF DISEASES IN CAPTIVE RED WOLVES (CANIS RUFUS), 1997-2012.
Seeley, Kathryn E; Garner, Michael M; Waddell, William T; Wolf, Karen N
2016-03-01
Conservation efforts to preserve the red wolf (Canis rufus) have been in progress since the 1970s through the U.S. Fish and Wildlife Service Red Wolf Recovery Program and the Association of Zoos and Aquarium's Red Wolf Species Survival Plan. An ongoing part of this project has been to monitor mortality trends, particularly to look for potential genetic conditions resulting from inbreeding given the small founding population of only 14 individuals. An initial survey was conducted in the 1990s but a comprehensive assessment of the population has not been done since then. This retrospective review evaluates mortality in the population from 1997 to 2012 through analysis of gross necropsy and histology records provided by cooperating institutions that housed red wolves during the time period of interest. Of the 378 red wolves that died during this 15-yr period, 259 animals had gross necropsy records, histology records, or both that were evaluated. The major causes of neonatal death were parental trauma, stillbirth, or pneumonia. Overall, juveniles had very low mortality rates with only 12 wolves aged 30 days to 6 mo dying during the study period. The most common cause of death within the adult populations was neoplasia, with epithelial neoplasms, carcinomas, and adenocarcinomas being the most common types reported. Gastrointestinal disease was the second most common cause of death, particularly gastric dilation and volvulus, inflammatory bowel disease, and gastrointestinal perforations. These findings are in stark contrast to causes of mortality in the wild population, which are primarily due to human-related activities such as vehicular trauma, gunshot, or poisoning. Overall, the captive population has few health problems, but an increase in inflammatory bowel disease in particular warrants further investigation.
A novel mutation in SLITRK6 causes deafness and myopia in a Moroccan family.
Salime, Sara; Riahi, Zied; Elrharchi, Soukaina; Elkhattabi, Lamiae; Charoute, Hicham; Nahili, Halima; Rouba, Hassan; Kabine, Mostafa; Bonnet, Crystel; Petit, Christine; Barakat, Abdelhamid
2018-06-15
Deafness and myopia syndrome is characterized by moderate-profound, bilateral, congenital or prelingual deafness and high myopia. Autosomal recessive non-syndromic hearing loss is one of the most prevalent human genetic sensorineural defects. Myopia is by far the most common human eye disorder that is known to have a clear heritable component. The analysis of the two exons of SLITRK6 gene in a Moroccan family allowed us to identify a novel single deleterious mutation c.696delG, p.Trp232Cysfs*10 at homozygous state in the exon 2 of the SLITRK6, a gene reported to cause deafness and myopia in various populations. Copyright © 2018 Elsevier B.V. All rights reserved.
Cardiovascular services and human resources in Puerto Rico - 2008.
García-Palmieri, Mario R
2009-01-01
Available information (2004-2008) concerning population statistics, the occurrence of cardiovascular disease, cardiovascular services and human resources in Puerto Rico is presented. Relevant information concerning life expectancy at birth, death by specific causes in a recent four years period, the commonest causes of death, and the related cardiovascular risk factors prevalence data available is included. The surgical and medical interventional services rendered to cardiovascular patients in different institutions and their locations in Puerto Rico in the year 2008 is presented. Some remarks concerning the productivity of physicians by our Schools of Medicine is included. Information about ACGME accredited postgraduate cardiovascular training programs conducted in Puerto Rico is presented. Data concerning the prevalence of hypertension, diabetes mellitus, overweight and obesity obtained by BRFSS in presented.
Human behaviour can trigger large carnivore attacks in developed countries
Penteriani, Vincenzo; Delgado, María del Mar; Pinchera, Francesco; Naves, Javier; Fernández-Gil, Alberto; Kojola, Ilpo; Härkönen, Sauli; Norberg, Harri; Frank, Jens; Fedriani, José María; Sahlén, Veronica; Støen, Ole-Gunnar; Swenson, Jon E.; Wabakken, Petter; Pellegrini, Mario; Herrero, Stephen; López-Bao, José Vicente
2016-01-01
The media and scientific literature are increasingly reporting an escalation of large carnivore attacks on humans in North America and Europe. Although rare compared to human fatalities by other wildlife, the media often overplay large carnivore attacks on humans, causing increased fear and negative attitudes towards coexisting with and conserving these species. Although large carnivore populations are generally increasing in developed countries, increased numbers are not solely responsible for the observed rise in the number of attacks by large carnivores. Here we show that an increasing number of people are involved in outdoor activities and, when doing so, some people engage in risk-enhancing behaviour that can increase the probability of a risky encounter and a potential attack. About half of the well-documented reported attacks have involved risk-enhancing human behaviours, the most common of which is leaving children unattended. Our study provides unique insight into the causes, and as a result the prevention, of large carnivore attacks on people. Prevention and information that can encourage appropriate human behaviour when sharing the landscape with large carnivores are of paramount importance to reduce both potentially fatal human-carnivore encounters and their consequences to large carnivores. PMID:26838467
Human behaviour can trigger large carnivore attacks in developed countries.
Penteriani, Vincenzo; Delgado, María del Mar; Pinchera, Francesco; Naves, Javier; Fernández-Gil, Alberto; Kojola, Ilpo; Härkönen, Sauli; Norberg, Harri; Frank, Jens; Fedriani, José María; Sahlén, Veronica; Støen, Ole-Gunnar; Swenson, Jon E; Wabakken, Petter; Pellegrini, Mario; Herrero, Stephen; López-Bao, José Vicente
2016-02-03
The media and scientific literature are increasingly reporting an escalation of large carnivore attacks on humans in North America and Europe. Although rare compared to human fatalities by other wildlife, the media often overplay large carnivore attacks on humans, causing increased fear and negative attitudes towards coexisting with and conserving these species. Although large carnivore populations are generally increasing in developed countries, increased numbers are not solely responsible for the observed rise in the number of attacks by large carnivores. Here we show that an increasing number of people are involved in outdoor activities and, when doing so, some people engage in risk-enhancing behaviour that can increase the probability of a risky encounter and a potential attack. About half of the well-documented reported attacks have involved risk-enhancing human behaviours, the most common of which is leaving children unattended. Our study provides unique insight into the causes, and as a result the prevention, of large carnivore attacks on people. Prevention and information that can encourage appropriate human behaviour when sharing the landscape with large carnivores are of paramount importance to reduce both potentially fatal human-carnivore encounters and their consequences to large carnivores.
Streptococcus infection in human populations continues to be a major cause of morbidity and mortality. To evaluate the effect of genetic background and toll-like receptor 2 (TLR2) on antibacterial defense to streptococcal infection, eight genetically diverse strains of mic...
USDA-ARS?s Scientific Manuscript database
Salmonella enterica serotype Enteritidis (SE) is one of the most commonly reported causes of human salmonellosis. The low genetic diversity of SE measured by fingerprinting methods has made subtyping a challenge. In this study, we used whole genome sequencing to characterize a total of 125 SE and Sa...
Contamination of watersheds by fecal bacteria is a frequent cause for surface waters to be placed on the national impaired waters list. However, since the presence of fecal bacteria does not always indicate human fecal input, it is necessary to distinguish between fecal sources. ...
Drinking water disinfection by-products (DBPs) are of concern because some epidemiologic studies have shown that some DBPs are associated with cancer or adverse reproductive/developmental effects in human populations, and other studies have shown that certain DBPs cause similar h...
Drinking water disinfection by-products (DBPs) are of concern because epidemiologic studies have shown that they are associated with bladder cancer and adverse reproductive/developmental effects in human populations, and some cause cancer in laboratory animals. As a result, the U...
Sapp, Sarah G H; Rascoe, Lisa N; Wilkins, Patricia P; Handali, Sukwan; Gray, Elizabeth B; Eberhard, Mark; Woodhall, Dana M; Montgomery, Susan P; Bailey, Karen L; Lankau, Emily W; Yabsley, Michael J
2016-12-01
Baylisascaris procyonis roundworms can cause potentially fatal neural larva migrans in many species, including humans. However, the clinical spectrum of baylisascariasis is not completely understood. We tested 347 asymptomatic adult wildlife rehabilitators for B. procyonis antibodies; 24 were positive, suggesting that subclinical baylisascariasis is occurring among this population.
Reintroduction of native species to unoccupied portions of their historical range is a common management strategy to enhance the future viability of animal populations. This approach has met with mixed success, due to unforeseen impacts caused by human or other factors. Some of t...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rutqvist, Jonny; Cappa, Frederic; Rinaldi, Antonio P.
We summarize recent modeling studies of injection-induced fault reactivation, seismicity, and its potential impact on surface structures and nuisance to the local human population. We used coupled multiphase fluid flow and geomechanical numerical modeling, dynamic wave propagation modeling, seismology theories, and empirical vibration criteria from mining and construction industries. We first simulated injection-induced fault reactivation, including dynamic fault slip, seismic source, wave propagation, and ground vibrations. From co-seismic average shear displacement and rupture area, we determined the moment magnitude to about M w = 3 for an injection-induced fault reactivation at a depth of about 1000 m. We then analyzedmore » the ground vibration results in terms of peak ground acceleration (PGA), peak ground velocity (PGV), and frequency content, with comparison to the U.S. Bureau of Mines’ vibration criteria for cosmetic damage to buildings, as well as human-perception vibration limits. For the considered synthetic M w = 3 event, our analysis showed that the short duration, high frequency ground motion may not cause any significant damage to surface structures, and would not cause, in this particular case, upward CO 2 leakage, but would certainly be felt by the local population.« less
Yang, Daode; Song, Yucheng; Ma, Jianzhang; Li, Pengfei; Zhang, Hong; Price, Mark R Stanley; Li, Chunlin; Jiang, Zhigang
2016-01-01
The Milu (Père David’s deer, Elaphurus davidianus) became extinct in China in the early 20th century but was reintroduced to the country. The reintroduced Milu escaped from a nature reserve and dispersed to the south of the Yangtze River. We monitored these accidentally escaped Milu from 1995 to 2012. The escaped Milu searched for vacant habitat patches as “stepping stones” and established refuge populations. We recorded 122 dispersal events of the escaped Milu. Most dispersal events occurred in 1998, 2003, 2006 and 2010. Milu normally disperse in March, July and November. Average dispersal distance was 14.08 ± 9.03 km, with 91.41% shorter than 25 km. After 5 generations, by the end of 2012, 300 wild Milu were scattered in refuge populations in the eastern and southern edges of the Dongting Lake. We suggest that population density is the ultimate cause for Milu dispersal, whereas floods and human disturbance are proximate causes. The case of the Milu shows that accidentally escaped animals can establish viable populations; however, the dispersed animals were subject to chance in finding “stepping stones”. The re-wilded Milu persist as a meta-population with sub-populations linked by dispersals through marginal habitats in an anthropogenic landscape. PMID:27272326
D'Elia, Jesse; Haig, Susan M.; Mullins, Thomas D.; Miller, Mark P.
2016-01-01
Critically endangered species that have undergone severe population bottlenecks often have little remaining genetic variation, making it difficult to reconstruct population histories to apply in reintroduction and recovery strategies. By using ancient DNA techniques, it is possible to combine genetic evidence from the historical population with contemporary samples to provide a more complete picture of a species' genetic variation across its historical range and through time. Applying this approach, we examined changes in the mitochondrial DNA (mtDNA) control region (526 base pairs) of the endangered California Condor (Gymnogyps californianus). Results showed a >80% reduction in unique haplotypes over the past 2 centuries. We found no spatial sorting of haplotypes in the historical population; the periphery of the range contained haplotypes that were common throughout the historical range. Direct examination of mtDNA from California Condor museum specimens provided a new window into historical population connectivity and genetic diversity showing: (1) a substantial loss of haplotypes, which is consistent with the hypothesis that condors were relatively abundant in the nineteenth century, but declined rapidly as a result of human-caused mortality; and (2) no evidence of historical population segregation, meaning that the available genetic data offer no cause to avoid releasing condors in unoccupied portions of their historical range.
Why does Bangladesh remain so poor? Part II: eight answers.
Maloney, C
1985-01-01
Bangladeshis of varying background all over the country were asked why they think poverty persists to such an extent in Bangladesh. Their answers provide a new perspective on the situation. The initial response often blames outside and natural causes -- floods, droughts, lack of resources, low demand for the country's exports, or historic exploitation. It is true that Bangladesh has virtually no mineral resources except gas. Yet, the soil, water, and human labor add up to a huge potential. The Third Five Year Plan emphasizes use of the soil, irrigation, tanks, rivers, and human labor. These provide the only hope for reducing poverty a little during the next 5 years. Bangladeshis as well as foreign observers most commonly cite overpopulation as the cause of poverty. Population growth is a cause of present poverty in Bangladesh but is not the only cause of poverty. The Third Five Year Plan goal to reduce annual growth to 1.8% is ambitious, but even if it is achieved the population will double in a few decades. As it would most likely be impossible for Bangladesh to support such numbers and maintain political and economic stability, such growth will have to be prevented. Poverty in Bangladesh is party a result of the long history of low urbanization, weak institutions, spotty and inadequate physical infrastructure, and insufficient entrapreneurship. Other reasons cited as causes of persisting poverty include illiteracy, idleness, class exploitation, the selfishness of individuals, and a lack of trust among people. All of the efforts of the poor themselves, various agencies, and the government, as examined in the 1st part of this discussion, fail to indicate any reason to hope that poverty in Bangladesh can be dramatically reduced any time soon. The Third Five Year Plan foresees a possible reduction of the number of those in poverty by 10%. According to the Plan itself, those in or near poverty comprise 85% of the people. The conditions under which the people of some East Asian countries have virtually propelled themselves into a more dynamic economic situation simply do not exist in Bangladesh. Yet, by taking a long view of Bangladesh and its human history, some aspects appear bright. If the human population and the land resources are brought into a better equilibrium, the potential for a very large population to be supported on the land almost indefinitely, and without destroying the resource base, is much greater than in most parts of the world. The expressive culture and complex network of personal relations will continue to make life rich despite material poverty. The individualism which impedes the growth of stable institutions is beginning to exert itself in entrepreneurship. Finally, the government and the aid agencies are now on a track of "development" that is consistent with the realities of the Bengali peasant tradition.
Managing a subsidized predator population: Reducing common raven predation on desert tortoises
Boarman, W.I.
2003-01-01
Human communities often are an inadvertent source of food, water, and other resources to native species of wildlife. Because these resources are more stable and predictable than those in a natural environment, animals that subsist on them are able to increase in numbers and expand their range, much to the detriment of their competitors and species they prey upon. In the Mojave Desert, common ravens (Corvus corax) have benefited from human-provided resources to increase in population size precipitously in recent years. This trend has caused concern because ravens prey on juvenile desert tortoises (Gopherus agassizii), a federally threatened species. In this paper, I discuss management strategies to reduce raven predation on desert tortoises. The recommendations fall into three categories: (1) managing raven populations by reducing access to anthropogenic resources; (2) removing offending ravens or other birds in specially targeted tortoise management zones; and (3) continuing research on raven ecology, raven behavior, and methods of reducing raven predation on tortoises. I also recommend approaching the problem within an adaptive management framework: management efforts should first be employed as scientific experiments - with replicates and controls - to yield an unbiased assessment of their effectiveness. Furthermore, these strategies should be implemented in concert with actions that reduce other causes of desert tortoise mortality to aid the long-term recovery of their populations. Overall, the approaches outlined in this paper are widely applicable to the management of subsidized predators, particularly where they present a threat to a declining species of prey.
Improving fire season definition by optimized temporal modelling of daily human-caused ignitions.
Costafreda-Aumedes, S; Vega-Garcia, C; Comas, C
2018-07-01
Wildfire suppression management is usually based on fast control of all ignitions, especially in highly populated countries with pervasive values-at-risk. To minimize values-at-risk loss by improving response time of suppression resources it is necessary to anticipate ignitions, which are mainly caused by people. Previous studies have found that human-ignition patterns change spatially and temporally depending on socio-economic activities, hence, the deployment of suppression resources along the year should consider these patterns. However, full suppression capacity is operational only within legally established fire seasons, driven by past events and budgets, which limits response capacity and increases damages out of them. The aim of this study was to assess the temporal definition of fire seasons from the perspective of human-ignition patterns for the case study of Spain, where people cause over 95% of fires. Humans engage in activities that use fire as a tool in certain periods within a year, and in locations linked to specific spatial factors. Geographic variables (population, infrastructures, physiography and land uses) were used as explanatory variables for human-ignition patterns. The changing influence of these geographic variables on occurrence along the year was analysed with day-by-day logistic regression models. Daily models were built for all the municipal units in the two climatic regions in Spain (Atlantic and Mediterranean Spain) from 2002 to 2014, and similar models were grouped within continuous periods, designated as ignition-based seasons. We found three ignition-based seasons in the Mediterranean region and five in the Atlantic zones, not coincidental with calendar seasons, but with a high degree of agreement with current legally designated operational fire seasons. Our results suggest that an additional late-winter-early-spring fire season in the Mediterranean area and the extension of this same season in the Atlantic zone should be re-considered for operational purposes in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.
The consequences of human actions on risks for infectious diseases: a review
Lindahl, Johanna F.; Grace, Delia
2015-01-01
The human population is growing, requiring more space for food production, and needing more animals to feed it. Emerging infectious diseases are increasing, causing losses in both human and animal lives, as well as large costs to society. Many factors are contributing to disease emergence, including climate change, globalization and urbanization, and most of these factors are to some extent caused by humans. Pathogens may be more or less prone to emergence in themselves, and rapidly mutating viruses are more common among the emerging pathogens. The climate-sensitive vector-borne diseases are likely to be emerging due to climate changes and environmental changes, such as increased irrigation. This review lists the factors within pathogens that make them prone to emergence, and the modes of transmission that are affected. The anthropogenic changes contributing to disease emergence are described, as well as how they directly and indirectly cause either increased numbers of susceptible or exposed individuals, or cause increased infectivity. Many actions may have multiple direct or indirect effects, and it may be difficult to assess what the consequences may be. In addition, most anthropogenic drivers are related to desired activities, such as logging, irrigation, trade, and travelling, which the society is requiring. It is important to research more about the indirect and direct effects of the different actions to understand both the benefits and the risks. PMID:26615822
Health Risk Assessment of Cyanobacterial (Blue-green Algal) Toxins in Drinking Water
Falconer, Ian R.; Humpage, Andrew R.
2005-01-01
Cyanobacterial toxins have caused human poisoning in the Americas, Europe and Australia. There is accumulating evidence that they are present in treated drinking water supplies when cyanobacterial blooms occur in source waters. With increased population pressure and depleted groundwater reserves, surface water is becoming more used as a raw water source, both from rivers and lakes/reservoirs. Additional nutrients in water which arise from sewage discharge, agricultural run-off or storm water result in overabundance of cyanobacteria, described as a ‘water bloom’. The majority of cyanobacterial water-blooms are of toxic species, producing a diversity of toxins. The most important toxins presenting a risk to the human population are the neurotoxic alkaloids (anatoxins and paralytic shellfish poisons), the cyclic peptide hepatotoxins (microcystins) and the cytotoxic alkaloids (cylindrospermopsins). At the present time the only cyanobacteral toxin family that have been internationally assessed for health risk by the WHO are the microcystins, which cause acute liver injury and are active tumour promoters. Based on sub-chronic studies in rodents and pigs, a provisional Guideline Level for drinking water of 1μg/L of microcystin-LR has been determined. This has been adopted in legislation in countries in Europe, South America and Australasia. This may be revised in the light of future teratogenicity, reproductive toxicity and carcinogenicity studies. The other cyanobacterial toxin which has been proposed for detailed health risk assessment is cylindrospermopsin, a cytotoxic compound which has marked genotoxicity, probable mutagenicity, and is a potential carcinogen. This toxin has caused human poisoning from drinking water, and occurs in water supplies in the USA, Europe, Asia, Australia and South America. An initial health risk assessment is presented with a proposed drinking water Guideline Level of 1μg/L. There is a need for both increased monitoring data for toxins in drinking water and epidemiological studies on adverse health effects in exposed populations to clarify the extent of the health risk. PMID:16705800
Global alert to avian influenza virus infection: From H5N1 to H7N9
Poovorawan, Yong; Pyungporn, Sunchai; Prachayangprecha, Slinporn; Makkoch, Jarika
2013-01-01
Outbreak of a novel influenza virus is usually triggered by mutational change due to the process known as ‘antigenic shift’ or re-assortment process that allows animal-to-human or avian-to-human transmission. Birds are a natural reservoir for the influenza virus, and subtypes H5, H7, and H9 have all caused outbreaks of avian influenza in human populations. An especially notorious strain is the HPAI influenza virus H5N1, which has a mortality rate of approximately 60% and which has resulted in numerous hospitalizations, deaths, and significant economic loss. In March 2013, in Eastern China, there was an outbreak of the novel H7N9 influenza virus, which although less pathogenic in avian species, resulted in 131 confirmed cases and 36 deaths in humans over a two-month span. The rapid outbreak of this virus caused global concern but resulted in international cooperation to control the outbreak. Furthermore, cooperation led to valuable research-sharing including genome sequencing of the virus, the development of rapid and specific diagnosis, specimen sharing for future studies, and vaccine development. Although a H7N9 pandemic in the human population is possible due to its rapid transmissibility and extensive surveillance, the closure of the live-bird market will help mitigate the possibility of another H7N9 outbreak. In addition, further research into the source of the outbreak, pathogenicity of the virus, and the development of specific and sensitive detection assays will be essential for controlling and preparing for future H7N9 outbreaks. PMID:23916331
Paweska, J T
2015-08-01
Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease affecting domestic and wild ruminants, camels and humans. The causative agent of RVF, the RVF virus (RVFV), has the capacity to cause large and severe outbreaks in animal and human populations and to cross significant natural geographic barriers. Rift Valley fever is usually inapparent in non-pregnant adult animals, but pregnant animals and newborns can be severely affected; outbreaks are characterised by a sudden onset of abortions and high neonatal mortality. The majority of human infections are subclinical or associated with moderate to severe, non-fatal, febrile illness, but some patients may develop a haemorrhagic syndrome and/or ocular and neurological lesions. In both animals and humans, the primary site of RVFV replication and tissue pathology is the liver. Outbreaks of RVF are associated with persistent high rainfalls leading to massive flooding and the emergence of large numbers of competent mosquito vectors that transmit the virus to a wide range of susceptible vertebrate species. Outbreaks of RVF have devastating economic effects on countries for which animal trade constitutes the main source of national revenue. The propensity of the virus to spread into new territories and re-emerge in traditionally endemic regions, where it causes large outbreaks in human and animal populations, presents a formidable challenge for public and veterinary health authorities. The presence of competent mosquito vectors in RVF-free countries, the wide range of mammals susceptible to the virus, altering land use, the global changes in climate, and increased animal trade and travel are some of the factors which might contribute to international spread of RVF.
The genesis and source of the H7N9 influenza viruses causing human infections in China.
Lam, Tommy Tsan-Yuk; Wang, Jia; Shen, Yongyi; Zhou, Boping; Duan, Lian; Cheung, Chung-Lam; Ma, Chi; Lycett, Samantha J; Leung, Connie Yin-Hung; Chen, Xinchun; Li, Lifeng; Hong, Wenshan; Chai, Yujuan; Zhou, Linlin; Liang, Huyi; Ou, Zhihua; Liu, Yongmei; Farooqui, Amber; Kelvin, David J; Poon, Leo L M; Smith, David K; Pybus, Oliver G; Leung, Gabriel M; Shu, Yuelong; Webster, Robert G; Webby, Richard J; Peiris, Joseph S M; Rambaut, Andrew; Zhu, Huachen; Guan, Yi
2013-10-10
A novel H7N9 influenza A virus first detected in March 2013 has since caused more than 130 human infections in China, resulting in 40 deaths. Preliminary analyses suggest that the virus is a reassortant of H7, N9 and H9N2 avian influenza viruses, and carries some amino acids associated with mammalian receptor binding, raising concerns of a new pandemic. However, neither the source populations of the H7N9 outbreak lineage nor the conditions for its genesis are fully known. Using a combination of active surveillance, screening of virus archives, and evolutionary analyses, here we show that H7 viruses probably transferred from domestic duck to chicken populations in China on at least two independent occasions. We show that the H7 viruses subsequently reassorted with enzootic H9N2 viruses to generate the H7N9 outbreak lineage, and a related previously unrecognized H7N7 lineage. The H7N9 outbreak lineage has spread over a large geographic region and is prevalent in chickens at live poultry markets, which are thought to be the immediate source of human infections. Whether the H7N9 outbreak lineage has, or will, become enzootic in China and neighbouring regions requires further investigation. The discovery here of a related H7N7 influenza virus in chickens that has the ability to infect mammals experimentally, suggests that H7 viruses may pose threats beyond the current outbreak. The continuing prevalence of H7 viruses in poultry could lead to the generation of highly pathogenic variants and further sporadic human infections, with a continued risk of the virus acquiring human-to-human transmissibility.
The evolution of the diversity of cultures
Foley, R. A.; Mirazón Lahr, M.
2011-01-01
The abundant evidence that Homo sapiens evolved in Africa within the past 200 000 years, and dispersed across the world only within the past 100 000 years, provides us with a strong framework in which to consider the evolution of human diversity. While there is evidence that the human capacity for culture has a deeper history, going beyond the origin of the hominin clade, the tendency for humans to form cultures as part of being distinct communities and populations changed markedly with the evolution of H. sapiens. In this paper, we investigate ‘cultures’ as opposed to ‘culture’, and the question of how and why, compared to biological diversity, human communities and populations are so culturally diverse. We consider the way in which the diversity of human cultures has developed since 100 000 years ago, and how its rate was subject to environmental factors. We argue that the causes of this diversity lie in the distribution of resources and the way in which human communities reproduce over several generations, leading to fissioning of kin groups. We discuss the consequences of boundary formation through culture in their broader ecological and evolutionary contexts. PMID:21357230
Genomic Insights into Cardiomyopathies: A Comparative Cross-Species Review
Simpson, Siobhan; Rutland, Paul; Rutland, Catrin Sian
2017-01-01
In the global human population, the leading cause of non-communicable death is cardiovascular disease. It is predicted that by 2030, deaths attributable to cardiovascular disease will have risen to over 20 million per year. This review compares the cardiomyopathies in both human and non-human animals and identifies the genetic associations for each disorder in each species/taxonomic group. Despite differences between species, advances in human medicine can be gained by utilising animal models of cardiac disease; likewise, gains can be made in animal medicine from human genomic insights. Advances could include undertaking regular clinical checks in individuals susceptible to cardiomyopathy, genetic testing prior to breeding, and careful administration of breeding programmes (in non-human animals), further development of treatment regimes, and drugs and diagnostic techniques. PMID:29056678
Xu, Dong-Qiang; Tan, Xiao-Yu; Zhang, Bao-Wei; Wu, Tao; Liu, Ping; Sun, Shao-Jun; Cao, Yin-Guang
2016-03-01
The study was aimed to investigate the role of 3-bromopyruvate in inhibition of CD133+ U87 human glioma cell population growth. The results demonstrated that 3-bromopyruvate inhibited the viability of both CD133+ and parental cells derived from U87 human glioma cell line. However, the 3-bromopyruvate-induced inhibition in viability was more prominent in CD133+ cells at 10 μM concentration after 48 h. Treatment of CD133+ cells with 3-bromopyruvate caused reduction in cell population and cell size, membrane bubbling, and degradation of cell membranes. Hoechst 33258 staining showed condensation of chromatin material and fragmentation of DNA in treated CD133+ cells after 48 h. 3-Bromopyruvate inhibited the migration rate of CD133+ cells significantly compared to the parental cells. Flow cytometry revealed that exposure of CD133+ cells to 3-bromopyruvate increased the cell population in S phase from 24.5 to 37.9 % with increase in time from 12 to 48 h. In addition, 3-bromopyruvate significantly enhanced the expression of Bax and cleaved caspase 3 in CD133+ cells compared to the parental cells. Therefore, 3-bromopyruvate is a potent chemotherapeutic agent for the treatment of glioma by targeting stem cells selectively.
Emerging Ecosystems Change the Spatial Distribution of Top Carnivores Even in Poorly Populated Areas
Barbar, Facundo; Werenkraut, Victoria; Morales, Juan Manuel; Lambertucci, Sergio Agustín
2015-01-01
Humans affect biological diversity and species distribution patterns by modifying resource availability and generating novel environments where generalist species benefit and specialist species are rare. In particular, cities create local homogenization while roads fragment habitat, although both processes can increase food availability for some species that may be able to take advantage of this new source. We studied space use by birds of prey in relation to human construction, hypothesizing that these birds would be affected even in poorly populated areas. We worked in Northwestern Patagonia, Argentina, which is experiencing a high population growth, but still having very large unpopulated areas. We related the presence of raptors with different sources of human disturbance and found that both the abundance and richness of these birds were positively associated with anthropogenic environments. These results are driven mostly by a strong association between the medium-sized generalist species and these novel environments (mainly roads and cities). This may create an imbalance in intra-guild competitive abilities, modifying the normal structures of top carnivore hierarchies. Indeed, the structure of raptor communities seems to be changing, even in poorly populated areas, with anthropogenic constructions seemingly producing changes in wild areas more promptly than thought, a cause for concern in ecosystems conservation issues. PMID:25799547
Carrieri, Maria Patrizia; Protopopescu, Camelia; Marcellin, Fabienne; Rosellini, Silvia; Wittkop, Linda; Esterle, Laure; Zucman, David; Raffi, François; Rosenthal, Eric; Poizot-Martin, Isabelle; Salmon-Ceron, Dominique; Dabis, François; Spire, Bruno
2017-12-01
Coffee has anti-inflammatory and hepato-protective properties. In the general population, drinking ≥3cups of coffee/day has been associated with a 14% reduction in the risk of all-cause mortality. The aim of this study was to investigate the relationship between coffee consumption and the risk of all-cause mortality in patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). ANRS CO13 HEPAVIH is an ongoing French nationwide prospective cohort of patients co-infected with HIV-HCV collecting both medical and psychosocial/behavioural data (annual self-administered questionnaires). We used a Cox proportional hazards model to estimate the effect of elevated coffee consumption (≥3cups/day) at baseline on all-cause mortality during the cohort's five-year follow-up. Over a median [interquartile range] follow-up of 5.0 [3.9-5.9] years, 77 deaths occurred among 1,028 eligible patients (mortality rate 1.64/100 person-years; 95% confidence interval [CI] 1.31-2.05). Leading causes of death were HCV-related diseases (n=33, 43%), cancers unrelated to AIDS/HCV (n=9, 12%), and AIDS (n=8, 10%). At the first available visit, 26.6% of patients reported elevated coffee consumption. Elevated coffee consumption at baseline was associated with a 50% reduced risk of all-cause mortality (hazard ratio 0.5; CI 0.3-0.9; p=0.032), after adjustment for gender and psychosocial, behavioral and clinical time-varying factors. Drinking three or more cups of coffee per day halves all-cause mortality risk in patients co-infected with HIV-HCV. The benefits of coffee extracts and supplementing dietary intake with other anti-inflammatory compounds need to be evaluated in this population. Coffee has anti-inflammatory and hepato-protective properties but its effect on mortality risk has never been investigated in patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). This study shows that elevated coffee consumption (≥3cups/day) halves all-cause mortality risk in patients co-infected with HIV-HCV. The benefits of coffee extracts and supplementing dietary intake with other anti-inflammatory compounds need to be evaluated in this population. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Nelson, Martha I.; Stucker, Karla M.; Schobel, Seth A.; Dugan, Vivien G.; Nelson, Sarah W.; Sreevatsan, Srinand; Killian, Mary L.; Nolting, Jacqueline M.; Wentworth, David E.
2016-01-01
ABSTRACT The swine-human interface created at agricultural fairs, along with the generation of and maintenance of influenza A virus diversity in exhibition swine, presents an ongoing threat to public health. Nucleotide sequences of influenza A virus isolates collected from exhibition swine in Ohio (n = 262) and Indiana (n = 103) during 2009 to 2013 were used to investigate viral evolution and movement within this niche sector of the swine industry. Phylogenetic and Bayesian analyses were employed to identify introductions of influenza A virus to exhibition swine and study viral population dynamics. In 2013 alone, we identified 10 independent introductions of influenza A virus into Ohio and/or Indiana exhibition swine. Frequently, viruses from the same introduction were identified at multiple fairs within the region, providing evidence of rapid and widespread viral movement within the exhibition swine populations of the two states. While pigs moving from fair to fair to fair is possible in some locations, the concurrent detection of nearly identical strains at several fairs indicates that a common viral source was more likely. Importantly, we detected an association between the high number of human variant H3N2 (H3N2v) virus infections in 2012 and the widespread circulation of influenza A viruses of the same genotype in exhibition swine in Ohio fairs sampled that year. The extent of viral diversity observed in exhibition swine and the rapidity with which it disseminated across long distances indicate that novel strains of influenza A virus will continue to emerge and spread within exhibition swine populations, presenting an ongoing threat to humans. IMPORTANCE Understanding the underlying population dynamics of influenza A viruses in commercial and exhibition swine is central to assessing the risk for human infections with variant viruses, including H3N2v. We used viral genomic sequences from isolates collected from exhibition swine during 2009 to 2013 to understand how the peak of H3N2v cases in 2012 relates to long-term trends in the population dynamics of pandemic viruses recently introduced into commercial and exhibition swine in the United States. The results of our spatial analysis underscore the key role of rapid viral dispersal in spreading multiple genetic lineages throughout a multistate network of agricultural fairs, providing opportunities for divergent lineages to coinfect, reassort, and generate new viral genotypes. The higher genetic diversity of genotypes cocirculating in exhibition swine since 2013 could facilitate the evolution of new reassortants, potentially with even greater ability to cause severe infections in humans or cause human-to-human transmission, highlighting the need for continued vigilance. PMID:27681134
Havas, K A; Boone, R B; Hill, A E; Salman, M D
2014-06-01
Brucellosis has been reported in livestock and humans in the country of Georgia with Brucella melitensis as the most common species causing disease. Georgia lacked sufficient data to assess effectiveness of the various potential control measures utilizing a reliable population-based simulation model of animal-to-human transmission of this infection. Therefore, an agent-based model was built using data from previous studies to evaluate the effect of an animal-level infection control programme on human incidence and sheep flock and cattle herd prevalence of brucellosis in the Kakheti region of Georgia. This model simulated the patterns of interaction of human-animal workers, sheep flocks and cattle herds with various infection control measures and returned population-based data. The model simulates the use of control measures needed for herd and flock prevalence to fall below 2%. As per the model output, shepherds had the greatest disease reduction as a result of the infection control programme. Cattle had the greatest influence on the incidence of human disease. Control strategies should include all susceptible animal species, sheep and cattle, identify the species of brucellosis present in the cattle population and should be conducted at the municipality level. This approach can be considered as a model to other countries and regions when assessment of control strategies is needed but data are scattered. © 2013 Blackwell Verlag GmbH.
Levels of PCDDs and PCDFs in human milk from populations in Madrid and Paris
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gonzalez, M.J.; Hernandez, L.M.; Jimenez, B.
Human breast milk represents a good substrate to examine the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) background contamination of a population and also supplies important information about the exposure risk for nursing infants. Although adipose tissue and blood samples are commonly studied in the literature milk Dioxin levels are more specifically of concern because of the facility of sampling and also the potential health damage which may be caused to the breastfed babies by those highly toxic synthetic chemicals. The occurrence of dioxins in mother milk among the general population in all countries studied until now, has confirmed a widespread pollutionmore » and intake of those compounds. Dietary and other sources such as contaminated chemicals, industrial activity, waste combustion and leaded car gasoline may be responsible for such a contamination, and also for the differences among levels found in different countries. Human contamination by PCDDs and PCDFs from the environment is clearly a multisource problem. Human milk as well as other human fluids studies up to know have only found the presence of 2,3,7,8 substituted PCDD or PCDF congeners present. The reason for this congener specific retention is usually explained by the metabolic conversion on the 2,3,7, and 8 lateral positions in combination with high binding affinities for the cytosolic receptor proteins.« less
The consequences of poaching and anthropogenic change for forest elephants.
Breuer, Thomas; Maisels, Fiona; Fishlock, Vicki
2016-10-01
Poaching has devastated forest elephant populations (Loxodonta cyclotis), and their habitat is dramatically changing. The long-term effects of poaching and other anthropogenic threats have been well studied in savannah elephants (Loxodonta africana), but the impacts of these changes for Central Africa's forest elephants have not been discussed. We examined potential repercussions of these threats and the related consequences for forest elephants in Central Africa by summarizing the lessons learned from savannah elephants and small forest elephant populations in West Africa. Forest elephant social organization is less known than the social organization of savannah elephants, but the close evolutionary history of these species suggests that they will respond to anthropogenic threats in broadly similar ways. The loss of older, experienced individuals in an elephant population disrupts ecological, social, and population parameters. Severe reduction of elephant abundance within Central Africa's forests can alter plant communities and ecosystem functions. Poaching, habitat alterations, and human population increase are probably compressing forest elephants into protected areas and increasing human-elephant conflict, which negatively affects their conservation. We encourage conservationists to look beyond documenting forest elephant population decline and address the causes of these declines when developing conversation strategies. We suggest assessing the effectiveness of the existing protected-area networks for landscape connectivity in light of current industrial and infrastructure development. Longitudinal assessments of the effects of landscape changes on forest elephant sociality and behavior are also needed. Finally, lessons learned from West African elephant population loss and habitat fragmentation should be used to inform strategies for land-use planning and managing human-elephant interactions. © 2016 Society for Conservation Biology.
Behavioral responses of wolves to roads: scale-dependent ambivalence
Nelson, Lindsey; Wabakken, Petter; Sand, Håkan; Liberg, Olof
2014-01-01
Throughout their recent recovery in several industrialized countries, large carnivores have had to cope with a changed landscape dominated by human infrastructure. Population growth depends on the ability of individuals to adapt to these changes by making use of new habitat features and at the same time to avoid increased risks of mortality associated with human infrastructure. We analyzed the summer movements of 19 GPS-collared resident wolves (Canis lupus L.) from 14 territories in Scandinavia in relation to roads. We used resource and step selection functions, including >12000 field-checked GPS-positions and 315 kill sites. Wolves displayed ambivalent responses to roads depending on the spatial scale, road type, time of day, behavioral state, and reproductive status. At the site scale (approximately 0.1 km2), they selected for roads when traveling, nearly doubling their travel speed. Breeding wolves moved the fastest. At the patch scale (10 km2), house density rather than road density was a significant negative predictor of wolf patch selection. At the home range scale (approximately 1000 km2), breeding wolves increased gravel road use with increasing road availability, although at a lower rate than expected. Wolves have adapted to use roads for ease of travel, but at the same time developed a cryptic behavior to avoid human encounters. This behavioral plasticity may have been important in allowing the successful recovery of wolf populations in industrialized countries. However, we emphasize the role of roads as a potential cause of increased human-caused mortality. PMID:25419085
Strategies for assessing the implications of malformed frogs for environmental health.
Burkhart, J G; Ankley, G; Bell, H; Carpenter, H; Fort, D; Gardiner, D; Gardner, H; Hale, R; Helgen, J C; Jepson, P; Johnson, D; Lannoo, M; Lee, D; Lary, J; Levey, R; Magner, J; Meteyer, C; Shelby, M D; Lucier, G
2000-01-01
The recent increase in the incidence of deformities among natural frog populations has raised concern about the state of the environment and the possible impact of unidentified causative agents on the health of wildlife and human populations. An open workshop on Strategies for Assessing the Implications of Malformed Frogs for Environmental Health was convened on 4-5 December 1997 at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina. The purpose of the workshop was to share information among a multidisciplinary group with scientific interest and responsibility for human and environmental health at the federal and state level. Discussions highlighted possible causes and recent findings directly related to frog deformities and provided insight into problems and strategies applicable to continuing investigation in several areas. Possible causes of the deformities were evaluated in terms of diagnostics performed on field amphibians, biologic mechanisms that can lead to the types of malformations observed, and parallel laboratory and field studies. Hydrogeochemistry must be more integrated into environmental toxicology because of the pivotal role of the aquatic environment and the importance of fates and transport relative to any potential exposure. There is no indication of whether there may be a human health factor associated with the deformities. However, the possibility that causal agents may be waterborne indicates a need to identify the relevant factors and establish the relationship between environmental and human health in terms of hazard assessment. PMID:10620528
Behavioral responses of wolves to roads: scale-dependent ambivalence.
Zimmermann, Barbara; Nelson, Lindsey; Wabakken, Petter; Sand, Håkan; Liberg, Olof
2014-11-01
Throughout their recent recovery in several industrialized countries, large carnivores have had to cope with a changed landscape dominated by human infrastructure. Population growth depends on the ability of individuals to adapt to these changes by making use of new habitat features and at the same time to avoid increased risks of mortality associated with human infrastructure. We analyzed the summer movements of 19 GPS-collared resident wolves ( Canis lupus L.) from 14 territories in Scandinavia in relation to roads. We used resource and step selection functions, including >12000 field-checked GPS-positions and 315 kill sites. Wolves displayed ambivalent responses to roads depending on the spatial scale, road type, time of day, behavioral state, and reproductive status. At the site scale (approximately 0.1 km 2 ), they selected for roads when traveling, nearly doubling their travel speed. Breeding wolves moved the fastest. At the patch scale (10 km 2 ), house density rather than road density was a significant negative predictor of wolf patch selection. At the home range scale (approximately 1000 km 2 ), breeding wolves increased gravel road use with increasing road availability, although at a lower rate than expected. Wolves have adapted to use roads for ease of travel, but at the same time developed a cryptic behavior to avoid human encounters. This behavioral plasticity may have been important in allowing the successful recovery of wolf populations in industrialized countries. However, we emphasize the role of roads as a potential cause of increased human-caused mortality.
DeBono, Roberto; Vincenti, Karen; Calleja, Neville
2012-02-01
Scientific evidence shows that climate change is very likely the product of human behaviour and lifestyle. The effects of climate change on human health are diverse in nature and range from direct effects due to extreme weather events such as heat waves, floods and storms, to indirect effects such as those caused by water and food shortages. A telephone survey was conducted between January and February 2009, on a stratified representative random sample of the Maltese population over the age of 18 years (N = 310,819). Five hundred and forty-three individuals successfully participated in the survey giving a response rate of 92.7%. The respondent sample was very similar to the target population by gender (P = 0.977), age (P = 0.767) and district (P = 0.812). The results of the study demonstrate a very strong relationship between the perception of climate change as a threat to health and well-being, support for climate change mitigation policy and a willingness to implement measures to address climate change. The findings of this study show that the perception that climate change may claim lives, cause disease, reduce the standard of living and worsen water shortages, may be the strongest driver behind support for climate change mitigation policy and a willingness to act. It is recommended that, in order to gain more public support, climate change campaigns and risk communication strategies should frame climate change as a threat to human health and general well-being.
Salmona, Jordi; Salamolard, Marc; Fouillot, Damien; Ghestemme, Thomas; Larose, Jerry; Centon, Jean-François; Sousa, Vitor; Dawson, Deborah A.; Thebaud, Christophe; Chikhi, Lounès
2012-01-01
The exceptional biodiversity of Reunion Island is threatened by anthropogenic landscape changes that took place during the 350 years of human colonization. During this period the human population size increased dramatically from 250 to 800,000. The arrival of humans together with the development of agriculture, invasive species such as rats and cats, and deforestation has lead to the extinction of more than half of the original vertebrate species of the island. For the remaining species, significant work is being carried out to identify threats and conservation status, but little genetic work has been carried on some of the most endangered species. In the last decade theoretical studies have shown the ability of neutral genetic markers to infer the demographic history of endangered species and identify and date past population size changes (expansions or bottlenecks). In this study we provide the first genetic data on the critically endangered species the Reunion cuckoo-shrike Coracina newtoni. The Reunion cuckoo-shrike is a rare endemic forest bird surviving in a restricted 12-km2 area of forested uplands and mountains. The total known population consists of less than one hundred individuals out of which 45 were genotyped using seventeen polymorphic microsatellite loci. We found a limited level of genetic variability and weak population structure, probably due to the limited geographic distribution. Using Bayesian methods, we identified a strong decline in population size during the Holocene, most likely caused by an ancient climatic or volcanic event around 5000 years ago. This result was surprising as it appeared in apparent contradiction with the accepted theory of recent population collapse due to deforestation and predator introduction. These results suggest that new methods allowing for more complex demographic models are necessary to reconstruct the demographic history of populations. PMID:22916272
Jakupciak, John P; Wells, Jeffrey M; Karalus, Richard J; Pawlowski, David R; Lin, Jeffrey S; Feldman, Andrew B
2013-01-01
Large-scale genomics projects are identifying biomarkers to detect human disease. B. pseudomallei and B. mallei are two closely related select agents that cause melioidosis and glanders. Accurate characterization of metagenomic samples is dependent on accurate measurements of genetic variation between isolates with resolution down to strain level. Often single biomarker sensitivity is augmented by use of multiple or panels of biomarkers. In parallel with single biomarker validation, advances in DNA sequencing enable analysis of entire genomes in a single run: population-sequencing. Potentially, direct sequencing could be used to analyze an entire genome to serve as the biomarker for genome identification. However, genome variation and population diversity complicate use of direct sequencing, as well as differences caused by sample preparation protocols including sequencing artifacts and mistakes. As part of a Department of Homeland Security program in bacterial forensics, we examined how to implement whole genome sequencing (WGS) analysis as a judicially defensible forensic method for attributing microbial sample relatedness; and also to determine the strengths and limitations of whole genome sequence analysis in a forensics context. Herein, we demonstrate use of sequencing to provide genetic characterization of populations: direct sequencing of populations.
Jakupciak, John P.; Wells, Jeffrey M.; Karalus, Richard J.; Pawlowski, David R.; Lin, Jeffrey S.; Feldman, Andrew B.
2013-01-01
Large-scale genomics projects are identifying biomarkers to detect human disease. B. pseudomallei and B. mallei are two closely related select agents that cause melioidosis and glanders. Accurate characterization of metagenomic samples is dependent on accurate measurements of genetic variation between isolates with resolution down to strain level. Often single biomarker sensitivity is augmented by use of multiple or panels of biomarkers. In parallel with single biomarker validation, advances in DNA sequencing enable analysis of entire genomes in a single run: population-sequencing. Potentially, direct sequencing could be used to analyze an entire genome to serve as the biomarker for genome identification. However, genome variation and population diversity complicate use of direct sequencing, as well as differences caused by sample preparation protocols including sequencing artifacts and mistakes. As part of a Department of Homeland Security program in bacterial forensics, we examined how to implement whole genome sequencing (WGS) analysis as a judicially defensible forensic method for attributing microbial sample relatedness; and also to determine the strengths and limitations of whole genome sequence analysis in a forensics context. Herein, we demonstrate use of sequencing to provide genetic characterization of populations: direct sequencing of populations. PMID:24455204
Genetic Causes of Human NK Cell Deficiency and Their Effect on NK Cell Subsets
Mace, Emily M.; Orange, Jordan S.
2016-01-01
Human NK cells play critical roles in human host defense, particularly the control of viral infection and malignancy, and patients with congenital immunodeficiency affecting NK cell function or number can suffer from severe illness. The importance of NK cell function is particularly underscored in patients with primary immunodeficiency in which NK cells are the primary or sole affected population (NK cell deficiency, NKD). While NKD may lead to the absence of NK cells, we are also gaining an increasing appreciation of the effect that NKD may have on the generation of specific NK cell subsets. In turn, this leads to improved insights into the requirements for human NK cell subset generation, as well as their importance in immune homeostasis. The presence of inherently abnormally developed or functionally impaired NK cells, in particular, appears to be problematic in the way of interfering with normal human host defense and may be more impactful than low numbers of NK cells alone. Here, we review the known genetic causes of NKD and the insight that is derived by these into the requirements for human subset generation and, by extension, for NK cell-mediated immunity. PMID:27994588
Human gastrointestinal nematode infections: are new control methods required?
Stepek, Gillian; Buttle, David J; Duce, Ian R; Behnke, Jerzy M
2006-01-01
Gastrointestinal (GI) nematode infections affect 50% of the human population worldwide, and cause great morbidity as well as hundreds of thousands of deaths. Despite modern medical practices, the proportion of the population infected with GI nematodes is not falling. This is due to a number of factors, the most important being the lack of good healthcare, sanitation and health education in many developing countries. A relatively new problem is the development of resistance to the small number of drugs available to treat GI nematode infections. Here we review the most important parasitic GI nematodes and the methods available to control them. In addition, we discuss the current status of new anthelmintic treatments, particularly the plant cysteine proteinases from various sources of latex-bearing plants and fruits. PMID:16965561
Characteristics of chromosome instability in the human lymphoblast cell line WTK1
NASA Technical Reports Server (NTRS)
Schwartz, J. L.; Jordan, R.; Evans, H. H.
2001-01-01
The characteristics of spontaneous and radiation-induced chromosome instability were determined in each of 50 individual clones isolated from control populations of human lymphoblasts (WTK1), as well as from populations of these cells previously exposed to two different types of ionizing radiation, Fe-56 and Cs-137. The types of chromosome instability did not appear to change in clones surviving radiation exposure. Aneuploidy, polyploidy, chromosome dicentrics and translocations, and chromatid breaks and gaps were found in both control and irradiated clones. The primary effect of radiation exposure was to increase the number of cells within any one clone that had chromosome alterations. Chromosome instability was associated with telomere shortening and elevated levels of apoptosis. The results suggest that the proximal cause of chromosome instability is telomere shortening.
de la Rua-Domenech, Ricardo
2006-03-01
Amongst the members of the Mycobacterium tuberculosis complex (MTBC), M. tuberculosis is mainly a human pathogen, whereas M. bovis has a broad host range and is the principal agent responsible for tuberculosis (TB) in domestic and wild mammals. M. bovis also infects humans, causing zoonotic TB through ingestion, inhalation and, less frequently, by contact with mucous membranes and broken skin. Zoonotic TB is indistinguishable clinically or pathologically from TB caused by M. tuberculosis. Differentiation between the causative organisms may only be achieved by sophisticated laboratory methods involving bacteriological culture of clinical specimens, followed by typing of isolates according to growth characteristics, biochemical properties, routine resistance to pyrazinamide (PZA) and specific non-commercial nucleic acid techniques. All this makes it difficult to accurately estimate the proportion of human TB cases caused by M. bovis infection, particularly in developing countries. Distinguishing between the various members of the MTBC is essential for epidemiological investigation of human cases and, to a lesser degree, for adequate chemotherapy of the human TB patient. Zoonotic TB was formerly an endemic disease in the UK population, usually transmitted to man by consumption of raw cows' milk. Human infection with M. bovis in the UK has been largely controlled through pasteurization of cows' milk and systematic culling of cattle reacting to compulsory tuberculin tests. Nowadays the majority of the 7000 cases of human TB annually reported in the UK are due to M. tuberculosis acquired directly from an infectious person. In the period 1990-2003, between 17 and 50 new cases of human M. bovis infection were confirmed every year in the UK. This represented between 0.5% and 1.5% of all the culture-confirmed TB cases, a proportion similar to that of other industrialized countries. Most cases of zoonotic TB diagnosed in the UK are attributed to (i) reactivation of long-standing latent infections acquired before widespread adoption of milk pasteurization, or (ii) M. bovis infections contracted abroad. Since 1990, only one case has been documented in the UK of confirmed, indigenous human M. bovis infection recently acquired from an animal source. Therefore, for the overwhelming majority of the population, the risk of contracting M. bovis infection from animals appears to be extremely low. However, bovine TB is once again a major animal health problem in the UK. Given the increasing numbers of cattle herds being affected each year, physicians and other public health professionals must remember that zoonotic TB is not just a disease of the past. A significant risk of M. bovis infection remains in certain segments of the UK population in the form of (i) continuing on-farm consumption of unpasteurized cows' milk, (ii) retail sales by approved establishments of unpasteurized milk and dairy products and (iii) occupational exposure to infectious aerosols from tuberculous animals and their carcases.
Human-started wildfires expand the fire niche across the United States.
Balch, Jennifer K; Bradley, Bethany A; Abatzoglou, John T; Nagy, R Chelsea; Fusco, Emily J; Mahood, Adam L
2017-03-14
The economic and ecological costs of wildfire in the United States have risen substantially in recent decades. Although climate change has likely enabled a portion of the increase in wildfire activity, the direct role of people in increasing wildfire activity has been largely overlooked. We evaluate over 1.5 million government records of wildfires that had to be extinguished or managed by state or federal agencies from 1992 to 2012, and examined geographic and seasonal extents of human-ignited wildfires relative to lightning-ignited wildfires. Humans have vastly expanded the spatial and seasonal "fire niche" in the coterminous United States, accounting for 84% of all wildfires and 44% of total area burned. During the 21-y time period, the human-caused fire season was three times longer than the lightning-caused fire season and added an average of 40,000 wildfires per year across the United States. Human-started wildfires disproportionally occurred where fuel moisture was higher than lightning-started fires, thereby helping expand the geographic and seasonal niche of wildfire. Human-started wildfires were dominant (>80% of ignitions) in over 5.1 million km 2 , the vast majority of the United States, whereas lightning-started fires were dominant in only 0.7 million km 2 , primarily in sparsely populated areas of the mountainous western United States. Ignitions caused by human activities are a substantial driver of overall fire risk to ecosystems and economies. Actions to raise awareness and increase management in regions prone to human-started wildfires should be a focus of United States policy to reduce fire risk and associated hazards.
Human-started wildfires expand the fire niche across the United States
Balch, Jennifer K.; Bradley, Bethany A.; Nagy, R. Chelsea; Fusco, Emily J.; Mahood, Adam L.
2017-01-01
The economic and ecological costs of wildfire in the United States have risen substantially in recent decades. Although climate change has likely enabled a portion of the increase in wildfire activity, the direct role of people in increasing wildfire activity has been largely overlooked. We evaluate over 1.5 million government records of wildfires that had to be extinguished or managed by state or federal agencies from 1992 to 2012, and examined geographic and seasonal extents of human-ignited wildfires relative to lightning-ignited wildfires. Humans have vastly expanded the spatial and seasonal “fire niche” in the coterminous United States, accounting for 84% of all wildfires and 44% of total area burned. During the 21-y time period, the human-caused fire season was three times longer than the lightning-caused fire season and added an average of 40,000 wildfires per year across the United States. Human-started wildfires disproportionally occurred where fuel moisture was higher than lightning-started fires, thereby helping expand the geographic and seasonal niche of wildfire. Human-started wildfires were dominant (>80% of ignitions) in over 5.1 million km2, the vast majority of the United States, whereas lightning-started fires were dominant in only 0.7 million km2, primarily in sparsely populated areas of the mountainous western United States. Ignitions caused by human activities are a substantial driver of overall fire risk to ecosystems and economies. Actions to raise awareness and increase management in regions prone to human-started wildfires should be a focus of United States policy to reduce fire risk and associated hazards. PMID:28242690
West Nile virus population genetics and evolution
Pesko, Kendra N.; Ebel, Gregory D.
2015-01-01
West Nile virus (WNV) (Flaviviridae: Flavivirus) is transmitted from mosquitoes to birds, but can cause fatal encephalitis in infected humans. Since its introduction into North America in New York in 1999, it has spread throughout the western hemisphere. Multiple outbreaks have also occurred in Europe over the last 20 years. This review highlights recent efforts to understand how host pressures impact viral population genetics, genotypic and phenotypic changes which have occurred in the WNV genome as it adapts to this novel environment, and molecular epidemiology of WNV worldwide. Future research directions are also discussed. PMID:22226703
Grøntvedt, Carl Andreas; Er, Chiek; Gjerset, Britt; Hauge, Anna Germundsson; Brun, Edgar; Jørgensen, Anne; Lium, Bjørn; Framstad, Tore
2013-07-01
Influenza A viruses cause respiratory infection in humans and pigs, and some serotypes can be transmitted between these species. The emergence of influenza A(H1N1)pdm09 virus infections in the spring of 2009 quickly led to a worldwide pandemic in humans, with subsequent introduction of the virus to pig populations. Following a widespread infection in the human population in Norway, influenza A(H1N1)pdm09 virus was introduced to the influenza A naïve Norwegian pig population, and within a few months pigs in more than one third of Norwegian swine herds had antibodies against the virus. A cross-sectional study was performed on all swine nucleus and multiplier herds in Norway to analyze risk factors for introduction of infection, and the preventive effects of recommended biosecurity practices. A surveillance program provided information on infection status of the study herds, and a questionnaire was administered to all 118 nucleus and multiplier herds to collect information on herd variables. The surveillance program revealed that pigs in 42% of the herds had antibodies against influenza A(H1N1)pdm09 virus. The incidence of serologically positive pigs was similar in both multiplier herds (41%) and closed nucleus herds (43%). Multivariable logistic regression showed that presence of farm staff with influenza-like illness (ILI) (OR=4.15, CI 1.5-11.4, p=0.005) and herd size (OR=1.01, CI 1-1.02, p=0.009) were risk factors for infection. The rapid and widespread seroconversion for antibodies against influenza A(H1N1)pdm09 virus in the Norwegian pig population can be explained by the emergence of a novel virus that is readily transmitted between people and swine in a largely susceptible population of humans, and an entirely naïve population of pigs. Copyright © 2013 Elsevier B.V. All rights reserved.
A red tide of Alexandrium fundyense in the Gulf of Maine.
McGillicuddy, D J; Brosnahan, M L; Couture, D A; He, R; Keafer, B A; Manning, J P; Martin, J L; Pilskaln, C H; Townsend, D W; Anderson, D M
2014-05-01
In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense .
A red tide of Alexandrium fundyense in the Gulf of Maine
NASA Astrophysics Data System (ADS)
McGillicuddy, D. J.; Brosnahan, M. L.; Couture, D. A.; He, R.; Keafer, B. A.; Manning, J. P.; Martin, J. L.; Pilskaln, C. H.; Townsend, D. W.; Anderson, D. M.
2014-05-01
In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense.
USDA-ARS?s Scientific Manuscript database
Cowpea crops are widely cultivated and a major nutritional source of protein for indigenous human populations in West Africa. Annual yields and longevity of grain storage is greatly reduced by feeding damage caused by a complex of insect pests that include Anoplocnemis curvipes, Aphis craccivora, Cl...
How Do Insects Help the Environment?
ERIC Educational Resources Information Center
Hevel, Gary
2005-01-01
There are some 5 to 30 million insect species estimated in the world--and the majority of these have yet to be collected or named by science! Of course, the most well known insects are those that cause disease or compete for human agricultural products, but these insects represent only a small fraction of the world's insect population. In reality,…
USDA-ARS?s Scientific Manuscript database
Campylobacter is one of the leading causes of food-borne illness in the United States, and epidemiological evidence indicates poultry and poultry products to be a significant source of human Campylobacter infections. Caprylic acid, an 8-carbon medium chain fatty acid, can reduce Campylobacter colon...
Regional Educational Strategies-Methods to Promote Human Resource Development in Small Businesses
ERIC Educational Resources Information Center
Knapp, Kornelius; Zschunke, Melanie
2009-01-01
Over the next few decades, demographic change will cause significant changes in the working population. how businesses prepare for these changes will have a decisive impact on whether this transformation has a beneficial or detrimental effect on the economy. Small and medium-sized businesses do not possess the resources required to develop and…
Phillip E. Baigas; John R. Squires; Lucretia E. Olson; Jacob S. Ivan; Elizabeth. K. Roberts
2017-01-01
Carnivores are particularly sensitive to reductions in population connectivity caused by human disturbance and habitat fragmentation. Permeability of transportation corridors to carnivore movements is central to species conservation given the large spatial extent of transportation networks and the high mobility of many carnivore species. We investigated the degree to...
Looking out for the pileated woodpecker.
Noreen Parks
2009-01-01
The pileated woodpecker is a species of conservation concern and a keystone species in mature and old forests of the Pacific Northwest. In the Blue Mountains of northeast Oregon, researchers from the PNW Research Station in La Grande, Oregon, studied the effects of natural and human-caused disturbance on pileated populations and their habitat over a period spanning...
Diet and Cancer Are Cooked Meats Involved
LLNL - University of California Television
2017-12-09
Diet has been associated with differences in cancer rates in human populations for many years. Mark Knize presents the latest research on cancer causes including work performed at Lawrence Livermore National Laboratory investigating some interesting chemical products created when meat is cooked and how to reduce them. Series: Science on Saturday [10/2006] [Health and Medicine] [Science] [Show ID: 11542
Techno-Arrogance and Halfway Technologies: Salmon Hatcheries on the Pacific Coast of North America.
ERIC Educational Resources Information Center
Meffe, Gary K.
1993-01-01
Discusses an attempt to recover Pacific salmonid fisheries with hatcheries as an example of a human attitude toward nature that places technological mastery over nature at the forefront of our approach to many environmental problems. Points out how this approach addresses the symptoms but not the causes of the salmon population decline. Suggests…
Parmar, Parveen K; Benjamin-Chung, Jade; Smith, Linda S; Htoo, Saw Nay; Laeng, Sai; Lwin, Aye; Mahn, Mahn; Maung, Cynthia; Reh, Daniel; Shwe Oo, Eh Kalu; Lee, Thomas; Richards, Adam K
2014-05-05
Myanmar/Burma has received increased development and humanitarian assistance since the election in November 2010. Monitoring the impact of foreign assistance and economic development on health and human rights requires knowledge of pre-election conditions. From October 2008-January 2009, community-based organizations conducted household surveys using three-stage cluster sampling in Shan, Kayin, Bago, Kayah, Mon and Tanintharyi areas of Myanmar. Data was collected from 5,592 heads of household on household demographics, reproductive health, diarrhea, births, deaths, malaria, and acute malnutrition of children 6-59 months and women aged 15-49 years. A human rights focused survey module evaluated human rights violations (HRVs) experienced by household members during the previous year. Estimated infant and under-five rates were 77 (95% CI 56 to 98) and 139 (95% CI 107 to 171) deaths per 1,000 live births; and the crude mortality rate was 13 (95% CI 11 to 15) deaths per thousand persons. The leading respondent-reported cause of death was malaria, followed by acute respiratory infection and diarrhea, causing 21.2% (95% CI 16.5 to 25.8), 16.6% (95% CI 11.8 to 21.4), and 12.3% (95% CI 8.7 to 15.8), respectively. Over a third of households suffered at least one human rights violation in the preceding year (36.2%; 30.7 to 41.7). Household exposure to forced labor increased risk of death among infants (rate ratio (RR) = 2.2; 95% CI 1.1 to 4.4) and children under five (RR = 2.1; 95% CI 1.3 to 3.6). The proportion of children suffering from moderate to severe acute malnutrition was higher among households that were displaced (prevalence ratio (PR) = 3.3; 95% CI 1.9 to 5.6). Prior to the 2010 election, populations of eastern Myanmar experienced high rates of disease and death and high rates of HRVs. These population-based data provide a baseline that can be used to monitor national and international efforts to improve the health and human rights situation in the region.
2014-01-01
Background Myanmar/Burma has received increased development and humanitarian assistance since the election in November 2010. Monitoring the impact of foreign assistance and economic development on health and human rights requires knowledge of pre-election conditions. Methods From October 2008-January 2009, community-based organizations conducted household surveys using three-stage cluster sampling in Shan, Kayin, Bago, Kayah, Mon and Tanintharyi areas of Myanmar. Data was collected from 5,592 heads of household on household demographics, reproductive health, diarrhea, births, deaths, malaria, and acute malnutrition of children 6–59 months and women aged 15–49 years. A human rights focused survey module evaluated human rights violations (HRVs) experienced by household members during the previous year. Results Estimated infant and under-five rates were 77 (95% CI 56 to 98) and 139 (95% CI 107 to 171) deaths per 1,000 live births; and the crude mortality rate was 13 (95% CI 11 to 15) deaths per thousand persons. The leading respondent-reported cause of death was malaria, followed by acute respiratory infection and diarrhea, causing 21.2% (95% CI 16.5 to 25.8), 16.6% (95% CI 11.8 to 21.4), and 12.3% (95% CI 8.7 to 15.8), respectively. Over a third of households suffered at least one human rights violation in the preceding year (36.2%; 30.7 to 41.7). Household exposure to forced labor increased risk of death among infants (rate ratio (RR) = 2.2; 95% CI 1.1 to 4.4) and children under five (RR = 2.1; 95% CI 1.3 to 3.6). The proportion of children suffering from moderate to severe acute malnutrition was higher among households that were displaced (prevalence ratio (PR) = 3.3; 95% CI 1.9 to 5.6). Conclusions Prior to the 2010 election, populations of eastern Myanmar experienced high rates of disease and death and high rates of HRVs. These population-based data provide a baseline that can be used to monitor national and international efforts to improve the health and human rights situation in the region. PMID:24885540
The arms race between man and Mycobacterium tuberculosis: Time to regroup.
Hoal, Eileen G; Dippenaar, Anzaan; Kinnear, Craig; van Helden, Paul D; Möller, Marlo
2017-08-23
An arms race is an appropriate metaphor to use for the interaction of man and Mycobacterium tuberculosis (M.tb) through the millennia. Estimates of the time of infection of modern humans with M.tb often pre-date the Out-of-Africa migration. Humans have adapted to the changing environment during the migration with respect to climate, food sources and encounters with local pathogens. More recently, there has been adaptation to the demographic changes brought about in the majority of the human population by the Neolithic revolution. By chance and/or selection, specific variants in immune defence have arisen in different population groups. These select for M.tb strains more fit to cause disease and be transmitted, sometimes by exploiting defence systems effective on other bacteria. The different selection pressures on the M.tb lineages carried by specific human groups have resulted in a worldwide M.tb population that is geographically structured according to the humans historically found there. A similar structure is seen with pathogens such as M. leprae and Helicobacter pylori. Modern M.tb strains have emerged which may be more fit, such as the Beijing lineage, leading to their rapid spread both in the areas where they arose, and into new areas after recent introduction. The speed at which this is occurring is outpacing coevolution for the time being. By using the results of genome wide and other association studies, as well as admixture mapping and 'natural experiments' in areas where both a number of populations, admixed populations, and a variety of M.tb strains occur, we can investigate the forces that have driven the coevolution of man and M.tb. The diversity of human and bacterial genetic background may be used in the future to discover and target the specific host-pathogen interactions leading to tuberculosis diseases, which suggests the potential for rational design of vaccines and host-directed therapies. Copyright © 2017 Elsevier B.V. All rights reserved.
Simwami, Sitali P.; Khayhan, Kantarawee; Henk, Daniel A.; Aanensen, David M.; Boekhout, Teun; Hagen, Ferry; Brouwer, Annemarie E.; Harrison, Thomas S.; Donnelly, Christl A.; Fisher, Matthew C.
2011-01-01
The global burden of HIV-associated cryptococcal meningitis is estimated at nearly one million cases per year, causing up to a third of all AIDS-related deaths. Molecular epidemiology constitutes the main methodology for understanding the factors underpinning the emergence of this understudied, yet increasingly important, group of pathogenic fungi. Cryptococcus species are notable in the degree that virulence differs amongst lineages, and highly-virulent emerging lineages are changing patterns of human disease both temporally and spatially. Cryptococcus neoformans variety grubii (Cng, serotype A) constitutes the most ubiquitous cause of cryptococcal meningitis worldwide, however patterns of molecular diversity are understudied across some regions experiencing significant burdens of disease. We compared 183 clinical and environmental isolates of Cng from one such region, Thailand, Southeast Asia, against a global MLST database of 77 Cng isolates. Population genetic analyses showed that Thailand isolates from 11 provinces were highly homogenous, consisting of the same genetic background (globally known as VNI) and exhibiting only ten nearly identical sequence types (STs), with three (STs 44, 45 and 46) dominating our sample. This population contains significantly less diversity when compared against the global population of Cng, specifically Africa. Genetic diversity in Cng was significantly subdivided at the continental level with nearly half (47%) of the global STs unique to a genetically diverse and recombining population in Botswana. These patterns of diversity, when combined with evidence from haplotypic networks and coalescent analyses of global populations, are highly suggestive of an expansion of the Cng VNI clade out of Africa, leading to a limited number of genotypes founding the Asian populations. Divergence time testing estimates the time to the most common ancestor between the African and Asian populations to be 6,920 years ago (95% HPD 122.96 - 27,177.76). Further high-density sampling of global Cng STs is now necessary to resolve the temporal sequence underlying the global emergence of this human pathogen. PMID:21573144
Simwami, Sitali P; Khayhan, Kantarawee; Henk, Daniel A; Aanensen, David M; Boekhout, Teun; Hagen, Ferry; Brouwer, Annemarie E; Harrison, Thomas S; Donnelly, Christl A; Fisher, Matthew C
2011-04-01
The global burden of HIV-associated cryptococcal meningitis is estimated at nearly one million cases per year, causing up to a third of all AIDS-related deaths. Molecular epidemiology constitutes the main methodology for understanding the factors underpinning the emergence of this understudied, yet increasingly important, group of pathogenic fungi. Cryptococcus species are notable in the degree that virulence differs amongst lineages, and highly-virulent emerging lineages are changing patterns of human disease both temporally and spatially. Cryptococcus neoformans variety grubii (Cng, serotype A) constitutes the most ubiquitous cause of cryptococcal meningitis worldwide, however patterns of molecular diversity are understudied across some regions experiencing significant burdens of disease. We compared 183 clinical and environmental isolates of Cng from one such region, Thailand, Southeast Asia, against a global MLST database of 77 Cng isolates. Population genetic analyses showed that Thailand isolates from 11 provinces were highly homogenous, consisting of the same genetic background (globally known as VNI) and exhibiting only ten nearly identical sequence types (STs), with three (STs 44, 45 and 46) dominating our sample. This population contains significantly less diversity when compared against the global population of Cng, specifically Africa. Genetic diversity in Cng was significantly subdivided at the continental level with nearly half (47%) of the global STs unique to a genetically diverse and recombining population in Botswana. These patterns of diversity, when combined with evidence from haplotypic networks and coalescent analyses of global populations, are highly suggestive of an expansion of the Cng VNI clade out of Africa, leading to a limited number of genotypes founding the Asian populations. Divergence time testing estimates the time to the most common ancestor between the African and Asian populations to be 6,920 years ago (95% HPD 122.96 - 27,177.76). Further high-density sampling of global Cng STs is now necessary to resolve the temporal sequence underlying the global emergence of this human pathogen.
Effects of Remedial Sport Hunting on Cougar Complaints and Livestock Depredations
Peebles, Kaylie A.; Wielgus, Robert B.; Maletzke, Benjamin T.; Swanson, Mark E.
2013-01-01
Remedial sport hunting of predators is often used to reduce predator populations and associated complaints and livestock depredations. We assessed the effects of remedial sport hunting on reducing cougar complaints and livestock depredations in Washington from 2005 to 2010 (6 years). The number of complaints, livestock depredations, cougars harvested, estimated cougar populations, human population and livestock populations were calculated for all 39 counties and 136 GMUs (game management units) in Washington. The data was then analyzed using a negative binomial generalized linear model to test for the expected negative relationship between the number of complaints and depredations in the current year with the number of cougars harvested the previous year. As expected, we found that complaints and depredations were positively associated with human population, livestock population, and cougar population. However, contrary to expectations we found that complaints and depredations were most strongly associated with cougars harvested the previous year. The odds of increased complaints and livestock depredations increased dramatically (36 to 240%) with increased cougar harvest. We suggest that increased young male immigration, social disruption of cougar populations, and associated changes in space use by cougars - caused by increased hunting resulted in the increased complaints and livestock depredations. Widespread indiscriminate hunting does not appear to be an effective preventative and remedial method for reducing predator complaints and livestock depredations. PMID:24260291
Environmental change disrupts communication and sexual selection in a stickleback population.
Candolin, Ulrika; Tukiainen, Iina; Bertell, Elina
2016-04-01
Environmental change that disrupts communication during mate choice and alters sexual selection could influence population dynamics. Yet little is known about such long-term effects. We investigated experimentally the consequences that disrupted visual communication during mate choice has for the quantity and viability of offspring produced in a threespine stickleback population (Gasterosteus aculeatus). We further related the results to long-term monitoring of population dynamics in the field to determine if changes are apparent under natural conditions. The results show that impaired visual communication because of algal blooms reduces reliability of male visual signals as indicators of offspring survival during their first weeks of life. This relaxes sexual selection but has no effect on the number of offspring hatching, as most males have a high hatching success in turbid water. Despite eutrophication and high turbidity levels that interfere with communication during mate choice, the population has grown during recent decades. Large numbers of offspring hatching, combined with high variation in juvenile fitness, has probably shifted selection to later life history stages and maintained a viable population. Together with reduced cost of sexual selection and ongoing ecosystem changes caused by human activities, this could have promoted population growth. These results point to the complexity of ecosystems and the necessity to consider all influencing factors when attempting to understand impacts of human activities on populations.
Koel, Björn F.; Mögling, Ramona; Chutinimitkul, Salin; Fraaij, Pieter L.; Burke, David F.; van der Vliet, Stefan; de Wit, Emmie; Bestebroer, Theo M.; Rimmelzwaan, Guus F.; Osterhaus, Albert D. M. E.; Smith, Derek J.; Fouchier, Ron A. M.
2015-01-01
ABSTRACT The majority of currently circulating influenza A(H1N1) viruses are antigenically similar to the virus that caused the 2009 influenza pandemic. However, antigenic variants are expected to emerge as population immunity increases. Amino acid substitutions in the hemagglutinin protein can result in escape from neutralizing antibodies, affect viral fitness, and change receptor preference. In this study, we constructed mutants with substitutions in the hemagglutinin of A/Netherlands/602/09 in an attenuated backbone to explore amino acid changes that may contribute to emergence of antigenic variants in the human population. Our analysis revealed that single substitutions affecting the loop that consists of amino acid positions 151 to 159 located adjacent to the receptor binding site caused escape from ferret and human antibodies elicited after primary A(H1N1)pdm09 virus infection. The majority of these substitutions resulted in similar or increased replication efficiency in vitro compared to that of the virus carrying the wild-type hemagglutinin and did not result in a change of receptor preference. However, none of the substitutions was sufficient for escape from the antibodies in sera from individuals that experienced both seasonal and pandemic A(H1N1) virus infections. These results suggest that antibodies directed against epitopes on seasonal A(H1N1) viruses contribute to neutralization of A(H1N1)pdm09 antigenic variants, thereby limiting the number of possible substitutions that could lead to escape from population immunity. IMPORTANCE Influenza A viruses can cause significant morbidity and mortality in humans. Amino acid substitutions in the hemagglutinin protein can result in escape from antibody-mediated neutralization. This allows the virus to reinfect individuals that have acquired immunity to previously circulating strains through infection or vaccination. To date, the vast majority of A(H1N1)pdm09 strains remain antigenically similar to the virus that caused the 2009 influenza pandemic. However, antigenic variants are expected to emerge as a result of increasing population immunity. We show that single amino acid substitutions near the receptor binding site were sufficient to escape from antibodies specific for A(H1N1)pdm09 viruses but not from antibodies elicited in response to infections with seasonal A(H1N1) and A(H1N1)pdm09 viruses. This study identified substitutions in A(H1N1)pdm09 viruses that support escape from population immunity but also suggested that the number of potential escape variants is limited by previous exposure to seasonal A(H1N1) viruses. PMID:25609810
Modelling the balance between quiescence and cell death in normal and tumour cell populations.
Spinelli, Lorenzo; Torricelli, Alessandro; Ubezio, Paolo; Basse, Britta
2006-08-01
When considering either human adult tissues (in vivo) or cell cultures (in vitro), cell number is regulated by the relationship between quiescent cells, proliferating cells, cell death and other controls of cell cycle duration. By formulating a mathematical description we see that even small alterations of this relationship may cause a non-growing population to start growing with doubling times characteristic of human tumours. Our model consists of two age structured partial differential equations for the proliferating and quiescent cell compartments. Model parameters are death rates from and transition rates between these compartments. The partial differential equations can be solved for the steady-age distributions, giving the distribution of the cells through the cell cycle, dependent on specific model parameter values. Appropriate formulas can then be derived for various population characteristic quantities such as labelling index, proliferation fraction, doubling time and potential doubling time of the cell population. Such characteristic quantities can be estimated experimentally, although with decreasing precision from in vitro, to in vivo experimental systems and to the clinic. The model can be used to investigate the effects of a single alteration of either quiescence or cell death control on the growth of the whole population and the non-trivial dependence of the doubling time and other observable quantities on particular underlying cell cycle scenarios of death and quiescence. The model indicates that tumour evolution in vivo is a sequence of steady-states, each characterised by particular death and quiescence rate functions. We suggest that a key passage of carcinogenesis is a loss of the communication between quiescence, death and cell cycle machineries, causing a defect in their precise, cell cycle dependent relationship.
The Public Health Implications of Resource Wars
Klare, Michael T.; Sidel, Victor W.
2011-01-01
Competition for resources between or within nations is likely to become an increasingly common cause of armed conflict. Competition for petroleum is especially likely to trigger armed conflict because petroleum is a highly valuable resource whose supply is destined to contract. Wars fought over petroleum and other resources can create public health concerns by causing morbidity and mortality, damaging societal infrastructure, diverting resources, uprooting people, and violating human rights. Public health workers and the organizations with which they are affiliated can help prevent resource wars and minimize their consequences by (1) promoting renewable energy and conservation, (2) documenting the impact of past and potential future resource wars, (3) protecting the human rights of affected noncombatant civilian populations during armed conflict, and (4) developing and advocating for policies that promote peaceful dispute resolution. PMID:21778501
Mayer, Sandra V.; Tesh, Robert B.; Vasilakis, Nikos
2016-01-01
Arthropod-borne viruses (arboviruses) present a substantial threat to human and animal health worldwide. Arboviruses can cause a variety of clinical presentations that range from mild to life threatening symptoms. Many arboviruses are present in nature through two distinct cycles, the urban and sylvatic cycle that are maintained in complex biological cycles. In this review we briefly discuss the factors driving the emergence of arboviruses, such as the anthropogenic aspects of unrestrained human population growth, economic expansion and globalization. Also the important aspects of viruses and vectors in the occurrence of arboviruses epidemics. The focus of this review will be on dengue, zika and chikungunya viruses, particularly because these viruses are currently causing a negative impact on public health and economic damage around the world. PMID:27876643
Rinehart, C A; Mayben, J P; Butler, T D; Haskill, J S; Kaufman, D G
1992-01-01
The normal genomic stability of human cells is reversed during neoplastic transformation. The SV40 large T antigen alters the DNA content in human endometrial stromal cells in a manner that relates to neoplastic progression. Human endometrial stromal cells were transfected with a plasmid containing the A209 temperature-sensitive mutant of SV40 (tsSV40), which is also defective in the viral origin of replication. Ninety-seven clonal transfectants from seven different primary cell strains were isolated. Initial analysis revealed that 20% of the clonal populations (19/97) had an apparent diploid DNA content, 35% (34/97) had an apparent tetraploid DNA content, and the remainder were mixed populations of diploid and tetraploid cells. No aneuploid populations were observed. Diploid tsSV40 transformed cells always give rise to a population of cells with a tetraploid DNA content when continuously cultured at the permissive temperature. The doubling of DNA content can be vastly accelerated by the sudden reintroduction of large T antigen activity following a shift from non-permissive to permissive temperature. Tetraploid tsSV40 transfected cells have a lower capacity for anchorage-independent growth and earlier entry into 'crisis' than diploid cells. These results indicate that during the pre-crisis, extended lifespan phase of growth, the SV40 large T antigen causes a doubling of DNA content. This apparent doubling of DNA content does not confer growth advantage during the extended lifespan that precedes 'crisis'.
Mingchay, Pichanon; Sai-Ngam, Arkhom; Phumee, Atchara; Bhakdeenuan, Payu; Lorlertthum, Kittitouch; Thavara, Usavadee; Tawatsin, Apiwat; Choochote, Wej; Siriyasatien, Padet
2014-03-01
Filth flies, belonging to suborder Brachycera (Family; Muscidae, Calliphoridae and Sarcophagidae), are a major cause of nuisance and able to transmit pathogens to humans and animals. These insects are distributed worldwide and their populations are increasing especially in sub-tropical and tropical areas. One strategy for controlling insects employs Wolbachia, which is a group of maternally inherited intracellular bacteria, found in many insect species. The bacteria can cause reproductive abnormalities in their hosts, such as cytoplasmic incompatibility, feminization, parthenogenesis, and male lethality. In this study we determined Wolbachia endosymbionts in natural population of medically important flies (42 females and 9 males) from several geographic regions of Thailand. Wolbachia supergroups A or B were detected in 7 of female flies using PCR specific for wsp. Sequence analysis of wsp showed variations between and within the Wolbachia supergroup. Phylogenetics demonstrated that wsp is able to diverge between Wolbachia supergroups A and B. These data should be useful in future Wolbachia-based programs of fly control.
Alavi, Seyed Mohammad; Alavi, Leila
2016-01-01
Human toxoplasmosis is an important zoonotic infection worldwide which is caused by the intracellular parasite Toxoplasma gondii (T.gondii). The aim of this study was to review briefly the general aspects of toxoplasma infection in in Iranian health system network. We searched published toxoplasmosis related articles in English databases including Science Direct, Pub Med, Scopus, Google Scholar, Magiran, Iran Medex, Iran Doc and Scientific Information Database (SID) for toxoplasmosis. Out of 1267 articles from the English and Persian databases search, 40 articles were suitable with our research objectives and so were selected for the study. It is estimated that at least a third of the world human population is infected with T.gondii, suggesting it as one of the most common parasitic infections through the world. Maternal infection during pregnancy may affect dangerous outcome for the fetus, or even cause intrauterine death. Reactivation of a previous infection in immunocompromised patient such as drug induced, AIDS and organ transplantation can cause life-threating central nervous system infection. Ocular toxoplasmosis is one of the most important causes of blindness, especially in individuals with a deficient immune system. According to the increasing burden of toxoplasmosis on human health, the findings of this study highlight the appropriate preventive measures, diagnosis, and management of this disease.
Evolutionary genomics of Entamoeba
Weedall, Gareth D.; Hall, Neil
2011-01-01
Entamoeba histolytica is a human pathogen that causes amoebic dysentery and leads to significant morbidity and mortality worldwide. Understanding the genome and evolution of the parasite will help explain how, when and why it causes disease. Here we review current knowledge about the evolutionary genomics of Entamoeba: how differences between the genomes of different species may help explain different phenotypes, and how variation among E. histolytica parasites reveals patterns of population structure. The imminent expansion of the amount genome data will greatly improve our knowledge of the genus and of pathogenic species within it. PMID:21288488
Esteves, F A; Caliman, A; Santangelo, J M; Guariento, R D; Farjalla, V F; Bozelli, R L
2008-11-01
Neotropical coastal lagoons (NCL) are human-dominated ecosystems. Their distribution along densely populated coastal areas of developing countries makes these systems among the most threatened in the world. Here, we summarize some aspects of the causes and consequences of NCL biodiversity, their functioning, their importance to the surrounding populations, their fragility, and their responses to local and global anthropogenic impacts and the challenges that Neotropical countries face in conserving these systems. Although still scarce and geographically concentrated, a growing body of studies has shown that NCLs are physiographically diversified systems, which harbor a considerable and particular proportion of the Neotropical inland aquatic biodiversity. Despite the fact that coastal lagoons are ecotones that are intricately connected to surrounding environments, they develop mechanisms for structural and functional regulation, which confer to these systems higher productivity and carrying capacities than surrounding ecosystems. Such traits attract residential developments and subsidize local traditional populations with important economic and aesthetic ecosystem revenues such as fisheries and scenic beauty. However, the disorganized human occupation around NCLs are causing profound impacts such as eutrophication, salinization, exotic species introduction, as well as other effects, which are ultimately imposing major habitat degradations and biodiversity extirpations in NCLs. We argue that interdisciplinary conservation strategies, which integrate scientific expertise, government officials, private companies and the general public, are the most likely to overcome the geographic and economic obstacles to NCL conservation.
Hollfelder, Nina; Babiker, Hiba
2017-01-01
Northeast Africa has a long history of human habitation, with fossil-finds from the earliest anatomically modern humans, and housing ancient civilizations. The region is also the gate-way out of Africa, as well as a portal for migration into Africa from Eurasia via the Middle East and the Arabian Peninsula. We investigate the population history of northeast Africa by genotyping ~3.9 million SNPs in 221 individuals from 18 populations sampled in Sudan and South Sudan and combine this data with published genome-wide data from surrounding areas. We find a strong genetic divide between the populations from the northeastern parts of the region (Nubians, central Arab populations, and the Beja) and populations towards the west and south (Nilotes, Darfur and Kordofan populations). This differentiation is mainly caused by a large Eurasian ancestry component of the northeast populations likely driven by migration of Middle Eastern groups followed by admixture that affected the local populations in a north-to-south succession of events. Genetic evidence points to an early admixture event in the Nubians, concurrent with historical contact between North Sudanese and Arab groups. We estimate the admixture in current-day Sudanese Arab populations to about 700 years ago, coinciding with the fall of Dongola in 1315/1316 AD, a wave of admixture that reached the Darfurian/Kordofanian populations some 400–200 years ago. In contrast to the northeastern populations, the current-day Nilotic populations from the south of the region display little or no admixture from Eurasian groups indicating long-term isolation and population continuity in these areas of northeast Africa. PMID:28837655
Hollfelder, Nina; Schlebusch, Carina M; Günther, Torsten; Babiker, Hiba; Hassan, Hisham Y; Jakobsson, Mattias
2017-08-01
Northeast Africa has a long history of human habitation, with fossil-finds from the earliest anatomically modern humans, and housing ancient civilizations. The region is also the gate-way out of Africa, as well as a portal for migration into Africa from Eurasia via the Middle East and the Arabian Peninsula. We investigate the population history of northeast Africa by genotyping ~3.9 million SNPs in 221 individuals from 18 populations sampled in Sudan and South Sudan and combine this data with published genome-wide data from surrounding areas. We find a strong genetic divide between the populations from the northeastern parts of the region (Nubians, central Arab populations, and the Beja) and populations towards the west and south (Nilotes, Darfur and Kordofan populations). This differentiation is mainly caused by a large Eurasian ancestry component of the northeast populations likely driven by migration of Middle Eastern groups followed by admixture that affected the local populations in a north-to-south succession of events. Genetic evidence points to an early admixture event in the Nubians, concurrent with historical contact between North Sudanese and Arab groups. We estimate the admixture in current-day Sudanese Arab populations to about 700 years ago, coinciding with the fall of Dongola in 1315/1316 AD, a wave of admixture that reached the Darfurian/Kordofanian populations some 400-200 years ago. In contrast to the northeastern populations, the current-day Nilotic populations from the south of the region display little or no admixture from Eurasian groups indicating long-term isolation and population continuity in these areas of northeast Africa.
Abortive Spontaneous Egg Activation: An Emerging Biological Threat for the Existence of Mammals.
Prasad, Shilpa; Tiwari, Meenakshi; Chaube, Shail K
2017-06-01
Mammals are important for balancing the natural ecosystem, but in the past few decades, several species have rapidly been entered under threatened category worldwide. The environmental changes, loss of natural habitats, human activities, and thereby stress are responsible for a gradual decline in reproductive outcome. Stress induces generation of reactive oxygen species (ROS). High physiological level of ROS drives abortive spontaneous egg activation (SEA), while beyond the physiological level causes oxidative stress (OS). The OS induces apoptosis and deteriorates egg quality that limits reproductive outcome. The reduced reproductive outcome is one of the major causes for gradual decline in population size of several mammalian species. Despite having several conservation programs, a gradual decline in species reproductive outcome and their population size is the serious concern for the existence of threatened mammalian species. Thus, it is important to identify and prevent the underlying causes responsible for abortive SEA, which could be an emerging problem for several mammalian species that are threatened or at the verge of extinction.
The role of fusion activity of influenza A viruses in their biological properties.
Jakubcová, L; Hollý, J; Varečková, E
2016-06-01
Influenza A viruses (IAVs) cause acute respiratory infections of humans, which are repeated yearly. Human IAV infections are associated with significant morbidity and mortality and therefore they represent a serious health problem. All human IAV strains are originally derived from avian IAVs, which, after their adaptation to humans, can spread in the human population and cause pandemics with more or less severe course of the disease. Presently, however, the potential of avian IAV to infect humans and to cause the disease cannot be predicted. Many studies are therefore focused on factors influencing the virulence and pathogenicity of IAV viruses in a given host. The virus-host interaction starts by virus attachment via the envelope glycoprotein hemagglutinin (HA) to the receptors on the cell surface. In addition to receptor binding, HA mediates also the fusion of viral and endosomal membranes, which follows the virus endocytosis. The fusion potential of HA trimer, primed by proteolytic cleavage, is activated by low pH in endosomes, resulting in HA refolding into the fusion-active form. The HA conformation change is predetermined by its 3-D structure, is pH-dependent, irreversible and strain-specific. The process of fusion activation of IAV hemagglutinin is crucial for virus entry into the cell and for the ability of the virus to replicate in the host. Here we discuss the known data about the characteristics of fusion activation of HA in relation to IAV virulence and pathogenicity.
Impact of human aging and modern lifestyle on gut microbiota.
Valle Gottlieb, Maria Gabriela; Closs, Vera Elizabeth; Junges, Vilma Maria; Schwanke, Carla Helena Augustin
2018-06-13
Human evolution and lifestyle changes caused by the agricultural and industrial revolutions have led to great advances in medicine and increased life expectancy, whilst also profoundly altering the ecological relationships and disease patterns of populations. Studies involving populations that still enjoy a rural way of life and with traits similar to the Paleolithic period reveal them to present a more robust, resistant and diverse gut microbiota, in comparison to highly industrialized civilizations. The human diet has expanded and broadened to include the consumption of high-calorie foods, particularly from animal sources such as game meat and eggs. For some time, authors have been alert to the fact that a modern lifestyle leads to reduced intake of beneficial bacteria, suggesting that nonpathogenic bacteria are being eradicated. Furthermore, therapeutic procedures, including the use of probiotics and prebiotics, have been proposed to lead to recovery of this microbiota, which is altered due to both the ageing process and lifestyle related aspects. Accordingly, this article aims to review the impact of human aging and modern lifestyle on gut microbiota, within an evolutionary, ecological, epidemiological and therapeutic context.
Metapopulation Dynamics Enable Persistence of Influenza A, Including A/H5N1, in Poultry
Hosseini, Parviez Rana; Fuller, Trevon; Harrigan, Ryan; Zhao, Delong; Arriola, Carmen Sofia; Gonzalez, Armandoe; Miller, Matthew Joshua; Xiao, Xiangming; Smith, Tom B.; Jones, Jamie Holland; Daszak, Peter
2013-01-01
Highly pathogenic influenza A/H5N1 has persistently but sporadically caused human illness and death since 1997. Yet it is still unclear how this pathogen is able to persist globally. While wild birds seem to be a genetic reservoir for influenza A, they do not seem to be the main source of human illness. Here, we highlight the role that domestic poultry may play in maintaining A/H5N1 globally, using theoretical models of spatial population structure in poultry populations. We find that a metapopulation of moderately sized poultry flocks can sustain the pathogen in a finite poultry population for over two years. Our results suggest that it is possible that moderately intensive backyard farms could sustain the pathogen indefinitely in real systems. This fits a pattern that has been observed from many empirical systems. Rather than just employing standard culling procedures to control the disease, our model suggests ways that poultry production systems may be modified. PMID:24312455
Frequency of the AGT Pro11Leu polymorphism in humans: Does diet matter?
Ségurel, Laure; Lafosse, Sophie; Heyer, Evelyne; Vitalis, Renaud
2010-01-01
The Pro11Leu substitution in the AGXT gene, which causes primary hyperoxaluria type 1, is found with high frequency in some human populations (e.g., 5-20% in Caucasians). It has been suggested that this detrimental mutation could have been positively selected in populations with a meat-rich diet. In order to test this hypothesis, we investigated the occurrence of Pro11Leu in both herder and agriculturalist populations from Central Asia. We found a lower frequency of this detrimental mutation in herders, whose diet is more meat-rich, as compared to agriculturalists, which therefore challenges the universality of the previous claim. Furthermore, when combining our original data with previously published results, we could show that the worldwide genetic differentiation measured at the Pro11Leu polymorphism does not depart from neutrality. Hence, the distribution of the variation observed in the AGXT gene could be due to demographic history, rather than local adaptation to diet.
NASA Technical Reports Server (NTRS)
Deloach, R.
1981-01-01
The Fraction Impact Method (FIM), developed by the National Research Council (NRC) for assessing the amount and physiological effect of noise, is described. Here, the number of people exposed to a given level of noise is multiplied by a weighting factor that depends on noise level. It is pointed out that the Aircraft-noise Levels and Annoyance MOdel (ALAMO), recently developed at NASA Langley Research Center, can perform the NRC fractional impact calculations for given modes of operation at any U.S. airport. The sensitivity of these calculations to errors in estimates of population, noise level, and human subjective response is discussed. It is found that a change in source noise causes a substantially smaller change in contour area than would be predicted simply on the basis of inverse square law considerations. Another finding is that the impact calculations are generally less sensitive to source noise errors than to systematic errors in population or subjective response.
Pathogenesis of Mortalin in Manganese-induced Parkinsonism
NASA Astrophysics Data System (ADS)
Cook, Travis J.
Manganese (Mn) is an essential dietary micronutrient for which excessive exposure has long been known to be neurotoxic. Historically, short-term, high-intensity exposure in occupational settings was recognized to cause acute-onset parkinsonism (PS) termed manganism. Although modern day exposures are typically several orders of magnitude lower than those necessary to cause manganism, chronic, low-level exposures are not uncommon among a number of occupations and communities. Recent epidemiologic studies have demonstrated an association between Mn exposure and risk of PS, and in this regard Mn remains a public health concern. The work described here was designed to provide insight toward questions which remain with respect to Mn exposure and its toxic effect on the brain, and includes studies utilizing Mn exposed human populations and in vitro model systems to address these objectives. Blood plasma samples obtained from a cohort of welders, whose work is recognized as generating appreciable amounts of airborne Mn, and post-mortem brain tissue of Mn mine workers were both found to have discernable alterations related to the mitochondrial chaperone protein mortalin. Furthermore, in vitro studies demonstrated that reduced astroglial expression of mortalin confers neuronal susceptibility to toxicity elicited by low levels of Mn, possibly via mechanisms of endoplasmic reticulum and oxidative stress mediated by alpha-synuclein. Taken together, the results of these studies indicate that Mn exposures experienced by modern day populations are sufficient to cause biological alterations in humans that are potentially neurotoxic.
Inokuchi, Shota; Yamashita, Yasuhiro; Nishimura, Kazuma; Nakanishi, Hiroaki; Saito, Kazuyuki
2017-11-01
Phenomena known as null alleles and peak imbalance can occur because of mutations in the primer binding sites used for DNA typing. In these cases, an accurate statistical evaluation of DNA typing is difficult. The estimated likelihood ratio is incorrectly calculated because of the null allele and allele dropout caused by mutation-induced peak imbalance. Although a number of studies have attempted to uncover examples of these phenomena, few reports are available on the human identification kit manufactured by Qiagen. In this study, 196 Japanese individuals who were heterozygous at D2S1360 were genotyped using an Investigator HDplex Kit with optimal amounts of DNA. A peak imbalance was frequently observed at the D2S1360 locus. We performed a sequencing analysis of the area surrounding the D2S1360 repeat motif to identify the cause for peak imbalance. A point mutation (G>A transition) 136 nucleotides upstream from the D2S1360 repeat motif was discovered in a number of samples. The allele frequency of the mutation was 0.0566 in the Japanese population. Therefore, human identification or kinship testing using the Investigator HDplex Kit requires caution because of the higher frequency of single nucleotide polymorphisms at the primer binding site of D2S1360 locus in the Japanese population.
McMaster, Sean R.; Gabbard, Jon D.; Koutsonanos, Dimitris G.; Compans, Richard W.; Tripp, Ralph A.; Tompkins, S. Mark; Kohlmeier, Jacob E.
2015-01-01
Influenza virus is a source of significant health and economic burden from yearly epidemics and sporadic pandemics. Given the potential for the emerging H7N9 influenza virus to cause severe respiratory infections and the lack of exposure to H7 and N9 influenza viruses in the human population, we aimed to quantify the H7N9 cross-reactive memory T cell reservoir in humans and mice previously exposed to common circulating influenza viruses. We identified significant cross-reactive T cell populations in humans and mice; we also found that cross-reactive memory T cells afforded heterosubtypic protection by reducing morbidity and mortality upon lethal H7N9 challenge. In context with our observation that PR8-primed mice have limited humoral cross-reactivity with H7N9, our data suggest protection from H7N9 challenge is indeed mediated by cross-reactive T cell populations established upon previous priming with another influenza virus. Thus, pre-existing cross-reactive memory T cells may limit disease severity in the event of an H7N9 influenza virus pandemic. PMID:25671696
Molecular epidemiology of African sleeping sickness.
Hide, G; Tait, A
2009-10-01
Human sleeping sickness in Africa, caused by Trypanosoma brucei spp. raises a number of questions. Despite the widespread distribution of the tsetse vectors and animal trypanosomiasis, human disease is only found in discrete foci which periodically give rise to epidemics followed by periods of endemicity A key to unravelling this puzzle is a detailed knowledge of the aetiological agents responsible for different patterns of disease--knowledge that is difficult to achieve using traditional microscopy. The science of molecular epidemiology has developed a range of tools which have enabled us to accurately identify taxonomic groups at all levels (species, subspecies, populations, strains and isolates). Using these tools, we can now investigate the genetic interactions within and between populations of Trypanosoma brucei and gain an understanding of the distinction between human- and nonhuman-infective subspecies. In this review, we discuss the development of these tools, their advantages and disadvantages and describe how they have been used to understand parasite genetic diversity, the origin of epidemics, the role of reservoir hosts and the population structure. Using the specific case of T.b. rhodesiense in Uganda, we illustrate how molecular epidemiology has enabled us to construct a more detailed understanding of the origins, generation and dynamics of sleeping sickness epidemics.
Achieving health equity: from root causes to fair outcomes.
Marmot, Michael
2007-09-29
Health is a universal human aspiration and a basic human need. The development of society, rich or poor, can be judged by the quality of its population's health, how fairly health is distributed across the social spectrum, and the degree of protection provided from disadvantage due to ill-health. Health equity is central to this premise and to the work of the Commission on Social Determinants of Health. Strengthening health equity--globally and within countries--means going beyond contemporary concentration on the immediate causes of disease. More than any other global health endeavour, the Commission focuses on the "causes of the causes"--the fundamental structures of social hierarchy and the socially determined conditions these create in which people grow, live, work, and age. The time for action is now, not just because better health makes economic sense, but because it is right and just. The outcry against inequity has been intensifying for many years from country to country around the world. These cries are forming a global movement. The Commission on Social Determinants of Health places action to ensure fair health at the head and the heart of that movement.
Human Health Impacts of and Public Health Adaptation to Climate Variability and Change
NASA Astrophysics Data System (ADS)
Ebi, K. L.
2007-12-01
Weather and climate are among the factors that determine the geographic range and incidence of several major causes of ill health, including undernutrition, diarrheal diseases and other conditions due to unsafe water and lack of basic sanitation, and malaria. The Human Health chapter in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change concluded that climate change has begun to negatively affect human health, and that projected climate change will increase the risks of climate-sensitive health outcomes, particularly in lower-income populations, predominantly within tropical/subtropical countries. Those at greatest risk include the urban poor, older adults, children, traditional societies, subsistence farmers, and coastal populations, particularly in low income countries. The cause-and-effect chain from climate change to changing patterns of health determinants and outcomes is complex and includes socioeconomic, institutional, and other factors. The severity of future impacts will be determined by changes in climate as well as by concurrent changes in nonclimatic factors and by the adaptation measures implemented to reduce negative impacts. Public health has a long history of effectively intervening to reduce risks to the health of individuals and communities. Lessons learned from more than 150 years of research and intervention can provide insights to guide the design and implementation of effective and efficient interventions to reduce the current and projected impacts of climate variability and change.
Epidemiologic Consequences of Microvariation in Mycobacterium tuberculosis
Mathema, Barun; Kurepina, Natalia; Yang, Guibin; Shashkina, Elena; Manca, Claudia; Mehaffy, Carolina; Bielefeldt-Ohmann, Helle; Ahuja, Shama; Fallows, Dorothy A.; Izzo, Angelo; Bifani, Pablo; Dobos, Karen; Kaplan, Gilla
2012-01-01
Background. Evidence from genotype-phenotype studies suggests that genetic diversity in pathogens have clinically relevant manifestations that can impact outcome of infection and epidemiologic success. We studied 5 closely related Mycobacterium tuberculosis strains that collectively caused extensive disease (n = 862), particularly among US-born tuberculosis patients. Methods. Representative isolates were selected using population-based genotyping data from New York City and New Jersey. Growth and cytokine/chemokine response were measured in infected human monocytes. Survival was determined in aerosol-infected guinea pigs. Results. Multiple genotyping methods and phylogenetically informative synonymous single nucleotide polymorphisms showed that all strains were related by descent. In axenic culture, all strains grew similarly. However, infection of monocytes revealed 2 growth phenotypes, slower (doubling ∼55 hours) and faster (∼25 hours). The faster growing strains elicited more tumor necrosis factor α and interleukin 1β than the slower growing strains, even after heat killing, and caused accelerated death of infected guinea pigs (∼9 weeks vs 24 weeks) associated with increased lung inflammation/pathology. Epidemiologically, the faster growing strains were associated with human immunodeficiency virus and more limited in spread, possibly related to their inherent ability to induce a strong protective innate immune response in immune competent hosts. Conclusions. Natural variation, with detectable phenotypic changes, among closely related clinical isolates of M. tuberculosis may alter epidemiologic patterns in human populations. PMID:22315279
Marchani, Elizabeth E; Watkins, W Scott; Bulayeva, Kazima; Harpending, Henry C; Jorde, Lynn B
2008-01-01
Background Near the junction of three major continents, the Caucasus region has been an important thoroughfare for human migration. While the Caucasus Mountains have diverted human traffic to the few lowland regions that provide a gateway from north to south between the Caspian and Black Seas, highland populations have been isolated by their remote geographic location and their practice of patrilocal endogamy. We investigate how these cultural and historical differences between highland and lowland populations have affected patterns of genetic diversity. We test 1) whether the highland practice of patrilocal endogamy has generated sex-specific population relationships, and 2) whether the history of migration and military conquest associated with the lowland populations has left Central Asian genes in the Caucasus, by comparing genetic diversity and pairwise population relationships between Daghestani populations and reference populations throughout Europe and Asia for autosomal, mitochondrial, and Y-chromosomal markers. Results We found that the highland Daghestani populations had contrasting histories for the mitochondrial DNA and Y-chromosome data sets. Y-chromosomal haplogroup diversity was reduced among highland Daghestani populations when compared to other populations and to highland Daghestani mitochondrial DNA haplogroup diversity. Lowland Daghestani populations showed Turkish and Central Asian affinities for both mitochondrial and Y-chromosomal data sets. Autosomal population histories are strongly correlated to the pattern observed for the mitochondrial DNA data set, while the correlation between the mitochondrial DNA and Y-chromosome distance matrices was weak and not significant. Conclusion The reduced Y-chromosomal diversity exhibited by highland Daghestani populations is consistent with genetic drift caused by patrilocal endogamy. Mitochondrial and Y-chromosomal phylogeographic comparisons indicate a common Near Eastern origin of highland populations. Lowland Daghestani populations show varying influence from Near Eastern and Central Asian populations. PMID:18637195
Endemic human fasciolosis in the Bolivian Altiplano.
Parkinson, M; O'Neill, S M; Dalton, J P
2007-05-01
Fasciolosis, caused by trematodes of the genus Fasciola, is an emerging disease of humans. One of the highest levels of human fasciolosis hepatica is found amongst the indigenous Aymaran people of the Northern Bolivian Altiplano. A meta-analysis of epidemiological surveys from 38 communities in the region demonstrates that fasciolosis has been endemic in the region since at least 1984 and is a zoonosis of rural communities. Human and bovine fasciolosis is associated with the communities lying in the plain from Lake Titicaca to La Paz, predominantly in the Los Andes province. In Los Andes incidences of up to 67% of population cohorts were found, and prevalence is age-related with the highest infection rate in children aged 8-11 years.
Lundgren-Kownacki, Karin; Kjellberg, Siri M; Gooch, Pernille; Dabaieh, Marwa; Anandh, Latha; Venugopal, Vidhya
2018-03-01
During the summer of 2015, India was hit by a scorching heat wave that melted pavements in Delhi and caused thousands of deaths, mainly among the most marginalized populations. One such group facing growing heat risks from both occupational and meteorological causes are migrant brick kiln workers. This study evaluates both current heat risks and the potential future impacts of heat caused by climate change, for the people working at brick kilns in India. A case study of heat stress faced by people working at brick kilns near Chennai, India, is the anchor point around which a transdisciplinary approach was applied. Around Chennai, the situation is alarming since occupational heat exposure in the hot season from March to July is already at the upper limits of what humans can tolerate before risking serious impairment. The aim of the study was to identify new pathways for change and soft solutions by both reframing the problem and expanding the solution space being considered in order to improve the quality of life for the migrant populations at the brick kilns. Technical solutions evaluated include the use of sun-dried mud bricks and other locally "appropriate technologies" that could mitigate the worsening of climate change-induced heat. Socio-cultural solutions discussed for empowering the people who work at the brick kilns include participatory approaches such as open re-localization, and rights-based approaches including the environmental sustainability and the human rights-based approach framework. Our analysis suggests that an integrative, transdisciplinary approach could incorporate a more holistic range of technical and socio-culturally informed solutions in order to protect the health of people threatened by India's brick kiln industry.
NASA Astrophysics Data System (ADS)
Lundgren-Kownacki, Karin; Kjellberg, Siri M.; Gooch, Pernille; Dabaieh, Marwa; Anandh, Latha; Venugopal, Vidhya
2018-03-01
During the summer of 2015, India was hit by a scorching heat wave that melted pavements in Delhi and caused thousands of deaths, mainly among the most marginalized populations. One such group facing growing heat risks from both occupational and meteorological causes are migrant brick kiln workers. This study evaluates both current heat risks and the potential future impacts of heat caused by climate change, for the people working at brick kilns in India. A case study of heat stress faced by people working at brick kilns near Chennai, India, is the anchor point around which a transdisciplinary approach was applied. Around Chennai, the situation is alarming since occupational heat exposure in the hot season from March to July is already at the upper limits of what humans can tolerate before risking serious impairment. The aim of the study was to identify new pathways for change and soft solutions by both reframing the problem and expanding the solution space being considered in order to improve the quality of life for the migrant populations at the brick kilns. Technical solutions evaluated include the use of sun-dried mud bricks and other locally "appropriate technologies" that could mitigate the worsening of climate change-induced heat. Socio-cultural solutions discussed for empowering the people who work at the brick kilns include participatory approaches such as open re-localization, and rights-based approaches including the environmental sustainability and the human rights-based approach framework. Our analysis suggests that an integrative, transdisciplinary approach could incorporate a more holistic range of technical and socio-culturally informed solutions in order to protect the health of people threatened by India's brick kiln industry.
[Biological and toxin terrorism weapons].
Bokan, Slavko
2003-03-01
The use of biological agents and toxins in warfare and terrorism has a long history. Human, animal and plant pathogens and toxins can cause disease and can be used as a threat to humans, animals and staple crops. The same is true for biological agents. Although the use of biological agents and toxins in military conflicts has been a concern of military communities for many years, several recent events have increased the awareness of terrorist use of these weapons against civilian population. A Mass Casualty Biological (Toxin) Weapon (MCBTW) is any biological and toxin weapon capable of causing death or disease on a large scale, such that the military or civilian infrastructure of the state or organization being attacked is overwhelmed. A militarily significant (or terrorist) weapon is any weapon capable of affecting, directly or indirectly, that is physically or psychologically, the outcome of a military operation. Although many biological agents such as toxins and bioregulators can be used to cause diseases, there are only a few that can truly threaten civilian populations on a large scale. Bioregulators or modulators are biochemical compounds, such as peptides, that occur naturally in organisms. They are new class of weapons that can damage nervous system, alter moods, trigger psychological changes and kill. The potential military or terrorist use of bioregulators is similar to that of toxins. Some of these compounds are several hundred times more potent than traditional chemical warfare agents. Important features and military advantages of new bioregulators are novel sites of toxic action; rapid and specific effects; penetration of protective filters and equipment, and militarily effective physical incapacitation. This overview of biological agents and toxins is largely intended to help healthcare providers on all levels to make decisions in protecting general population from these agents.
Couto-Lima, Dinair; Madec, Yoann; Bersot, Maria Ignez; Campos, Stephanie Silva; Motta, Monique de Albuquerque; Santos, Flávia Barreto Dos; Vazeille, Marie; Vasconcelos, Pedro Fernando da Costa; Lourenço-de-Oliveira, Ricardo; Failloux, Anna-Bella
2017-07-07
Yellow fever virus (YFV) causing a deadly viral disease is transmitted by the bite of infected mosquitoes. In Brazil, YFV is restricted to a forest cycle maintained between non-human primates and forest-canopy mosquitoes, where humans can be tangentially infected. Since late 2016, a growing number of human cases have been reported in Southeastern Brazil at the gates of the most populated areas of South America, the Atlantic coast, with Rio de Janeiro state hosting nearly 16 million people. We showed that the anthropophilic mosquitoes Aedes aegypti and Aedes albopictus as well as the YFV-enzootic mosquitoes Haemagogus leucocelaenus and Sabethes albiprivus from the YFV-free region of the Atlantic coast were highly susceptible to American and African YFV strains. Therefore, the risk of reemergence of urban YFV epidemics in South America is major with a virus introduced either from a forest cycle or by a traveler returning from the YFV-endemic region of Africa.
Amphibian and reptile declines over 35 years at La Selva, Costa Rica.
Whitfield, Steven M; Bell, Kristen E; Philippi, Thomas; Sasa, Mahmood; Bolaños, Federico; Chaves, Gerardo; Savage, Jay M; Donnelly, Maureen A
2007-05-15
Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these "enigmatic" declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by approximately 75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks.
Host response to Brucella infection: review and future perspective.
Elfaki, Mohamed G; Alaidan, Alwaleed Abdullah; Al-Hokail, Abdullah Abdulrahman
2015-07-30
Brucellosis is a zoonotic and contagious infectious disease caused by infection with Brucella species. The infecting brucellae are capable of causing a devastating multi-organ disease in humans with serious health complications. The pathogenesis of Brucella infection is influenced largely by host factors, Brucella species/strain, and the ability of invading brucellae to survive and replicate within mononuclear phagocytic cells, preferentially macrophages (Mf). Consequently, the course of human infection may appear as an acute fatal or progress into chronic debilitating infection with periodical episodes that leads to bacteremia and death. The existence of brucellae inside Mf represents one of the strategies used by Brucella to evade the host immune response and is responsible for treatment failure in certain human populations treated with anti-Brucella drugs. Moreover, the persistence of brucellae inside Mf complicates the diagnosis and may affect the host cell signaling pathways with consequent alterations in both innate and adaptive immune responses. Therefore, there is an urgent need to pursue the development of novel drugs and/or vaccine targets against human brucellosis using high throughput technologies in genomics, proteomics, and immunology.
Are We Prepared in Case of a Possible Smallpox-Like Disease Emergence?
Olson, Victoria A.; Shchelkunov, Sergei N.
2017-01-01
Smallpox was the first human disease to be eradicated, through a concerted vaccination campaign led by the World Health Organization. Since its eradication, routine vaccination against smallpox has ceased, leaving the world population susceptible to disease caused by orthopoxviruses. In recent decades, reports of human disease from zoonotic orthopoxviruses have increased. Furthermore, multiple reports of newly identified poxviruses capable of causing human disease have occurred. These facts raise concerns regarding both the opportunity for these zoonotic orthopoxviruses to evolve and become a more severe public health issue, as well as the risk of Variola virus (the causative agent of smallpox) to be utilized as a bioterrorist weapon. The eradication of smallpox occurred prior to the development of the majority of modern virological and molecular biological techniques. Therefore, there is a considerable amount that is not understood regarding how this solely human pathogen interacts with its host. This paper briefly recounts the history and current status of diagnostic tools, vaccines, and anti-viral therapeutics for treatment of smallpox disease. The authors discuss the importance of further research to prepare the global community should a smallpox-like virus emerge.
Koch, Evan; Novembre, John
2017-01-01
When mutations have small effects on fitness, population size plays an important role in determining the amount and nature of deleterious genetic variation. The extent to which recent population size changes have impacted deleterious variation in humans has been a question of considerable interest and debate. An emerging consensus is that the Out-of-Africa bottleneck and subsequent growth events have been too short to cause meaningful differences in genetic load between populations; though changes in the number and average frequencies of deleterious variants have taken place. To provide more support for this view and to offer additional insight into the divergent evolution of deleterious variation across populations, we numerically solve time-inhomogeneous diffusion equations and study the temporal dynamics of the frequency spectra in models of population size change for modern humans. We observe how the response to demographic change differs by the strength of selection, and we then assess whether similar patterns are observed in exome sequence data from 33,370 and 5203 individuals of non-Finnish European and West African ancestry, respectively. Our theoretical results highlight how even simple summaries of the frequency spectrum can have complex responses to demographic change. These results support the finding that some apparent discrepancies between previous results have been driven by the behaviors of the precise summaries of deleterious variation. Further, our empirical results make clear the difficulty of inferring slight differences in frequency spectra using recent next-generation sequence data. PMID:28159863
Cancer mortality in poultry slaughtering/processing plant workers belonging to a union pension fund.
Johnson, Eric S; Ndetan, Harrison; Lo, Ka-Ming
2010-08-01
The role of zoonotic biological agents in human cancer occurrence has been little studied. Humans are commonly exposed to viruses that naturally infect and cause cancer in food animals such as poultry that constitute part of the biological environment. It is not known if these viruses cause cancer in humans. To study cancer mortality in the largest cohort to date, of 20,132 workers in poultry slaughtering and processing plants, a group with the highest human exposures to these viruses. Mortality in poultry workers was compared with that in the US general population through the estimation of standardized mortality ratios. Significantly increased risks were observed in the cohort as a whole or in subgroups, for several cancer sites, viz: cancers of the buccal cavity and pharynx; pancreas; trachea/bronchus/lung; brain; cervix; lymphoid leukemia; monocytic leukemia; and tumors of the hemopoietic and lymphatic systems. Elevated SMRs that were not statistically significant were observed for cancers of the liver, nasopharynx, myelofibrosis, and myeloma. New sites observed to be significantly in excess in this study were cancers of the cervix and penis. This large study provides evidence that a human group with high exposure to poultry oncogenic viruses has increased risk of dying from several cancers. Other occupational carcinogenic exposures could be of importance in explaining some of the findings, such as fumes from wrapping machines. These findings may have implications for public health amongst persons in the general population who may also be exposed to these viruses. What is needed now are epidemiologic studies that can demonstrate whether the excess of specific cancers can be attributed to specific occupational exposures while adequately controlling for other potential occupational and non-occupational carcinogenic exposures. Copyright 2010 Elsevier Inc. All rights reserved.
Rapid population growth and environmental degradation: ultimate versus proximate factors.
Shaw, R P
1989-01-01
This philosophical review of 2 arguments about responsibility for and solutions to environmental degradation concludes that both sides are correct: the ultimate and the proximal causes. Ultimate causes of pollution are defined as the technology responsible for a given type of pollution, such as burning fossil fuel; proximate causes are defined as situation-specific factors confounding the problem, such as population density or rate of growth. Commoner and others argue that developed countries with low or negative population growth rates are responsible for 80% of world pollution, primarily in polluting technologies such as automobiles, power generation, plastics, pesticides, toxic wastes, garbage, warfaring, and nuclear weapons wastes. Distortionary policies also contribute; examples are agricultural trade protection, land mismanagement, urban bias in expenditures, and institutional rigidity., Poor nations are responsible for very little pollution because poverty allows little waste or expenditures for polluting, synthetic technologies. The proximal causes of pollution include numbers and rate of growth of populations responsible for the pollution. Since change in the ultimate cause of pollution remains out of reach, altering the numbers of polluters can make a difference. Predictions are made for proportions of the world's total waste production, assuming current 1.6 tons/capita for developed countries and 0.17 tons/capita for developing countries. If developing countries grow at current rates and become more wealthy, they will be emitting half the world's waste by 2025. ON the other hand, unsustainable population growth goes along with inadequate investment in human capital: education, health, employment, infrastructure. The solution is to improve farming technologies in the 117 non-self-sufficient countries, fund development in the most unsustainable enclaves of growing countries, break institutionalized socio-political rigidity in these enclaves, and focus on educating and empowering women in these enclaves. Women are in charge of birth spacing and all aspects of management of energy, food, water and the local environment, more so than men, in most countries.
Changes in bird-migration patterns associated with human-induced mortality.
Palacín, Carlos; Alonso, Juan C; Martín, Carlos A; Alonso, Javier A
2017-02-01
Many bird populations have recently changed their migratory behavior in response to alterations of the environment. We collected data over 16 years on male Great Bustards (Otis tarda), a species showing a partial migratory pattern (sedentary and migratory birds coexisting in the same breeding groups). We conducted population counts and radio tracked 180 individuals to examine differences in survival rates between migratory and sedentary individuals and evaluate possible effects of these differences on the migratory pattern of the population. Overall, 65% of individuals migrated and 35% did not. The average distance between breeding and postbreeding areas of migrant individuals was 89.9 km, and the longest average movement of sedentary males was 3.8 km. Breeding group and migration distance had no effect on survival. However, mortality of migrants was 2.4 to 3.5 times higher than mortality of sedentary birds. For marked males, collision with power lines was the main cause of death from unnatural causes (37.6% of all deaths), and migratory birds died in collisions with power lines more frequently than sedentary birds (21.3% vs 6.3%). The percentage of sedentary individuals increased from 17% in 1997 to 45% in 2012. These results were consistent with data collected from radio-tracked individuals: The proportion of migratory individuals decreased from 86% in 1997-1999 to 44% in 2006-2010. The observed decrease in the migratory tendency was not related to climatic changes (temperatures did not change over the study period) or improvements in habitat quality (dry cereal farmland area decreased in the main study area). Our findings suggest that human-induced mortality during migration may be an important factor shaping the migration patterns of species inhabiting humanized landscapes. © 2016 Society for Conservation Biology.
Li, Ting; Li, Jing; Zhou, Zixiang; Wang, Yanze; Yang, Xiaonan; Qin, Keyu; Liu, Jingya
2017-04-01
Carbon sequestration is an indispensable ecosystem service provided by soil and vegetation, so mapping and valuing the carbon budget by considering both ecological and social factors is an important trend in evaluating ecosystem services. In this work, we established multiple scenarios to evaluate the impacts of land use change, population growth, carbon emission per capita, and carbon markets on carbon budget. We quantified carbon sinks (aboveground and belowground) under different scenarios, using the Carnegie-Ames-Stanford Approach (CASA) model and an improved carbon cycle process model, and studied carbon sources caused by human activities by analyzing the spatial distribution of human population and carbon emission per capita. We also assessed the net present value (NPV) for carbon budgets under different carbon price and discount rate scenarios using NPV model. Our results indicate that the carbon budget of Guanzhong-Tianshui Economic Region is surplus: Carbon sinks range from 1.50 × 10 10 to 1.54 × 10 10 t, while carbon sources caused by human activities range from 2.76 × 10 5 to 7.60 × 10 5 t. And the NPV for carbon deficits range from 3.20 × 10 11 RMB to 1.52 × 10 12 RMB. From the perspective of ecological management, deforestation, urban sprawl, population growth, and excessive carbon consumption are considered as the main challenges in balancing carbon sources and sinks. Levying carbon tax would be a considerable option when decision maker develops carbon emission reduction policies. Our results provide a scientific and credible reference for harmonious and sustainable development in the Guanzhong-Tianshui Economic Region of China.
Temporal genetic change in the last remaining population of woolly mammoth
Nyström, Veronica; Dalén, Love; Vartanyan, Sergey; Lidén, Kerstin; Ryman, Nils; Angerbjörn, Anders
2010-01-01
During the Late Pleistocene, the woolly mammoth (Mammuthus primigenius) experienced a series of local extinctions generally attributed to human predation or environmental change. Some small and isolated populations did however survive far into the Holocene. Here, we investigated the genetic consequences of the isolation of the last remaining mammoth population on Wrangel Island. We analysed 741 bp of the mitochondrial DNA and found a loss of genetic variation in relation to the isolation event, probably caused by a demographic bottleneck or a founder event. However, in spite of ca 5000 years of isolation, we did not detect any further loss of genetic variation. Together with the relatively high number of mitochondrial haplotypes on Wrangel Island near the final disappearance, this suggests a sudden extinction of a rather stable population. PMID:20356891
Monaghan, A J; Sampson, K M; Steinhoff, D F; Ernst, K C; Ebi, K L; Jones, B; Hayden, M H
2018-02-01
The mosquito Aedes (Ae). aegypti transmits the viruses that cause dengue and chikungunya, two globally-important vector-borne diseases. We investigate how choosing alternate emissions and/or socioeconomic pathways may modulate future human exposure to Ae. aegypti . Occurrence patterns for Ae. aegypti for 2061-2080 are mapped globally using empirically downscaled air temperature and precipitation projections from the Community Earth System Model, for the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. Population growth is quantified using gridded global population projections consistent with two Shared Socioeconomic Pathways (SSPs), SSP3 and SSP5. Change scenarios are compared to a 1950-2000 reference period. A global land area of 56.9 M km 2 is climatically suitable for Ae. aegypti during the reference period, and is projected to increase by 8% (RCP4.5) to 13% (RCP8.5) by 2061-2080. The annual average number of people exposed globally to Ae. aegypti for the reference period is 3794 M, a value projected to statistically significantly increase by 298-460 M (8-12%) by 2061-2080 if only climate change is considered, and by 4805-5084 M (127-134%) for SSP3 and 2232-2483 M (59-65%) for SSP5 considering both climate and population change (lower and upper values of each range represent RCP4.5 and RCP8.5 respectively). Thus, taking the lower-emissions RCP4.5 pathway instead of RCP8.5 may mitigate future human exposure to Ae. aegypti globally, but the effect of population growth on exposure will likely be larger. Regionally, Australia, Europe and North America are projected to have the largest percentage increases in human exposure to Ae. aegypti considering only climate change.
Doocy, Shannon; Daniels, Amy; Packer, Catherine; Dick, Anna; Kirsch, Thomas D.
2013-01-01
Introduction. Population growth and increasing urbanization in earthquake-prone areas suggest that earthquake impacts on human populations will increase in the coming decades. Recent large earthquakes affecting large populations in Japan, Haiti, Chile and New Zealand are evidence of this trend and also illustrate significant variations in outcomes such damage and mortality levels. The objectives of this review were to describe the impact of earthquakes on human populations in terms of mortality, injury and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters. Methods. Data on the impact of earthquakes were compiled using two methods, a historical review from 1980 to mid 2009 of earthquake events from multiple databases and a systematic literature review of publications, ending in October 2012. Analysis included descriptive statistics and bivariate tests for associations between earthquake mortality and characteristics using STATA 11. Findings. From 1980 through 2009, there were a total of 372,634 deaths (range 314,634-412,599), 995,219 injuries (range: 845,345-1,145,093), and more than 61 million people affected by earthquakes, and mortality was greatest in Asia. Inconsistent reporting across data sources suggests that the numbers injured and affected are likely underestimates. Findings from a systematic review of the literature indicate that the primary cause of earthquake-related death was trauma due to building collapse and, the very young and the elderly were at increased mortality risk, while gender was not consistently associated with mortality risk. Conclusions. Strategies to mitigate the impact of future earthquakes should include improvements to the built environment and a focus on populations most vulnerable to mortality and injury. PMID:23857161
Distance to human populations influences epidemiology of respiratory disease in desert tortoises
Berry, Kristin H.; Ashley A. Coble (formerly Emerson), no longer USGS; Yee, Julie L.; Mack, Jeremy S.; Perry, William M.; Anderson, Kemp M.; Brown, Mary B.
2014-01-01
We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of test-positive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of human-populated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
J.Y. Wu; J.R. Thompson; R.K. Kolka; K.J. Franz; T.W. Stewart
2013-01-01
Streams are natural features in urban landscapes that can provide ecosystem services for urban residents. However, urban streams are under increasing pressure caused by multiple anthropogenic impacts, including increases in human population and associated impervious surface area, and accelerated climate change. The ability to anticipate these changes and better...
Neelam Poudyal; Cassandra Johnson Gaither; Scott Goodrick; J.M. Bowker; Jianbang Gan
2012-01-01
Wildland fire in the South commands considerable attention, given the expanding wildland urban interface (WUI) across the region. Much of this growth is propelled by higher income retirees and others desiring natural amenity residential settings. However, population growth in the WUI increases the likelihood of wildfire fire ignition caused by people, as humans account...
USDA-ARS?s Scientific Manuscript database
West Nile virus (WNV) represents a serious burden to human and animal health because of its capacity to cause large unforeseen epidemics. Until 2004, only lineage 1 and 3 WNV strains had been found in Europe. Lineage 2 strains were initially isolated in 2004 (Hungary), again in 2008 (Austria), and f...
Bird banding and climate change: can we make a difference?
C. John Ralph; Jared D. Wolfe
2014-01-01
So how does your banding effort fit into the new paradigm of climate science? A little background: many bird populations underwent mass declines during the 19th century from a variety of causes including hunting and habitat change. Current human-induced climate change represents a new and fast-acting pressure that is inherently more difficult to curtail and may drive...
Spatial patterns of modern period human-caused fire occurrence in the Missouri Ozark Highlands
Jian Yang; Hong S. Healy; Stephen R. Shifley; Eric J. Gustafson
2007-01-01
The spatial pattern of forest fire locations is important in the study of the dynamics of fire disturbance. In this article we used a spatial point process modeling approach to quantitatively study the effects of land cover, topography, roads, municipalities, ownership, and population density on fire occurrence reported between 1970 and 2002 in the Missouri Ozark...
Assessing plague risk and presence through surveys of small mammal flea communities
M. M. Friggens; P. L. Ford; R. R. Parmenter; M. Boyden; K. Gage
2011-01-01
Plague, caused by the bacterium Yersinia pestis, remains a threat to human and wildlife populations in the Western United States (Gage and Kosoy 2005). Several rodent species have been implicated as important maintenance hosts in the U.S., including Peromyscus maniculatus and Dipodomys spp. Fleas are a critical component of plague foci (Gage and Kosoy 2005)....
Dropping dead: causes and consequences of vulture population declines worldwide.
Ogada, Darcy L; Keesing, Felicia; Virani, Munir Z
2012-02-01
Vultures are nature's most successful scavengers, and they provide an array of ecological, economic, and cultural services. As the only known obligate scavengers, vultures are uniquely adapted to a scavenging lifestyle. Vultures' unique adaptations include soaring flight, keen eyesight, and extremely low pH levels in their stomachs. Presently, 14 of 23 (61%) vulture species worldwide are threatened with extinction, and the most rapid declines have occurred in the vulture-rich regions of Asia and Africa. The reasons for the population declines are varied, but poisoning or human persecution, or both, feature in the list of nearly every declining species. Deliberate poisoning of carnivores is likely the most widespread cause of vulture poisoning. In Asia, Gyps vultures have declined by >95% due to poisoning by the veterinary drug diclofenac, which was banned by regional governments in 2006. Human persecution of vultures has occurred for centuries, and shooting and deliberate poisoning are the most widely practiced activities. Ecological consequences of vulture declines include changes in community composition of scavengers at carcasses and an increased potential for disease transmission between mammalian scavengers at carcasses. There have been cultural and economic costs of vulture declines as well, particularly in Asia. In the wake of catastrophic vulture declines in Asia, regional governments, the international scientific and donor communities, and the media have given the crisis substantial attention. Even though the Asian vulture crisis focused attention on the plight of vultures worldwide, the situation for African vultures has received relatively little attention especially given the similar levels of population decline. While the Asian crisis has been largely linked to poisoning by diclofenac, vulture population declines in Africa have numerous causes, which have made conserving existing populations more difficult. And in Africa there has been little government support to conserve vultures despite mounting evidence of the major threats. In other regions with successful vulture conservation programs, a common theme is a huge investment of financial resources and highly skilled personnel, as well as political will and community support. © 2012 New York Academy of Sciences.
Yost, Chad L; Jackson, Lily J; Stone, Jeffery R; Cohen, Andrew S
2018-03-01
The temporal proximity of the ∼74 ka Toba supereruption to a putative 100-50 ka human population bottleneck is the basis for the volcanic winter/weak Garden of Eden hypothesis, which states that the eruption caused a 6-year-long global volcanic winter and reduced the effective population of anatomically modern humans (AMH) to fewer than 10,000 individuals. To test this hypothesis, we sampled two cores collected from Lake Malawi with cryptotephra previously fingerprinted to the Toba supereruption. Phytolith and charcoal samples were continuously collected at ∼3-4 mm (∼8-9 yr) intervals above and below the Toba cryptotephra position, with no stratigraphic breaks. For samples synchronous or proximal to the Toba interval, we found no change in low elevation tree cover, or in cool climate C 3 and warm season C 4 xerophytic and mesophytic grass abundance that is outside of normal variability. A spike in locally derived charcoal and xerophytic C 4 grasses immediately after the Toba eruption indicates reduced precipitation and die-off of at least some afromontane vegetation, but does not signal volcanic winter conditions. A review of Toba tuff petrological and melt inclusion studies suggest a Tambora-like 50 to 100 Mt SO 2 atmospheric injection. However, most Toba climate models use SO 2 values that are one to two orders of magnitude higher, thereby significantly overestimating the amount of cooling. A review of recent genetic studies finds no support for a genetic bottleneck at or near ∼74 ka. Based on these previous studies and our new paleoenvironmental data, we find no support for the Toba catastrophe hypothesis and conclude that the Toba supereruption did not 1) produce a 6-year-long volcanic winter in eastern Africa, 2) cause a genetic bottleneck among African AMH populations, or 3) bring humanity to the brink of extinction. Copyright © 2017 Elsevier Ltd. All rights reserved.
Enteric Protozoa in the Developed World: a Public Health Perspective
Fletcher, Stephanie M.; Stark, Damien; Harkness, John
2012-01-01
Summary: Several enteric protozoa cause severe morbidity and mortality in both humans and animals worldwide. In developed settings, enteric protozoa are often ignored as a cause of diarrheal illness due to better hygiene conditions, and as such, very little effort is used toward laboratory diagnosis. Although these protozoa contribute to the high burden of infectious diseases, estimates of their true prevalence are sometimes affected by the lack of sensitive diagnostic techniques to detect them in clinical and environmental specimens. Despite recent advances in the epidemiology, molecular biology, and treatment of protozoan illnesses, gaps in knowledge still exist, requiring further research. There is evidence that climate-related changes will contribute to their burden due to displacement of ecosystems and human and animal populations, increases in atmospheric temperature, flooding and other environmental conditions suitable for transmission, and the need for the reuse of alternative water sources to meet growing population needs. This review discusses the common enteric protozoa from a public health perspective, highlighting their epidemiology, modes of transmission, prevention, and control. It also discusses the potential impact of climate changes on their epidemiology and the issues surrounding waterborne transmission and suggests a multidisciplinary approach to their prevention and control. PMID:22763633
Litvintseva, Anastasia P.; Carbone, Ignazio; Rossouw, Jenny; Thakur, Rameshwari; Govender, Nelesh P.; Mitchell, Thomas G.
2011-01-01
Most of the species of fungi that cause disease in mammals, including Cryptococcus neoformans var. grubii (serotype A), are exogenous and non-contagious. Cryptococcus neoformans var. grubii is associated worldwide with avian and arboreal habitats. This airborne, opportunistic pathogen is profoundly neurotropic and the leading cause of fungal meningitis. Patients with HIV/AIDS have been ravaged by cryptococcosis – an estimated one million new cases occur each year, and mortality approaches 50%. Using phylogenetic and population genetic analyses, we present evidence that C. neoformans var. grubii may have evolved from a diverse population in southern Africa. Our ecological studies support the hypothesis that a few of these strains acquired a new environmental reservoir, the excreta of feral pigeons (Columba livia), and were globally dispersed by the migration of birds and humans. This investigation also discovered a novel arboreal reservoir for highly diverse strains of C. neoformans var. grubii that are restricted to southern Africa, the mopane tree (Colophospermum mopane). This finding may have significant public health implications because these primal strains have optimal potential for evolution and because mopane trees contribute to the local economy as a source of timber, folkloric remedies and the edible mopane worm. PMID:21589919
Animals are key to human toxoplasmosis.
Schlüter, Dirk; Däubener, Walter; Schares, Gereon; Groß, Uwe; Pleyer, Uwe; Lüder, Carsten
2014-10-01
Toxoplasma gondii is an extremely sucessfull protozoal parasite which infects almost all mamalian species including humans. Approximately 30% of the human population worldwide is chronically infected with T. gondii. In general, human infection is asymptomatic but the parasite may induce severe disease in fetuses and immunocompromised patients. In addition, T. gondii may cause sight-threatening posterior uveitis in immunocompetent patients. Apart from few exceptions, humans acquire T. gondii from animals. Both, the oral uptake of T. gondii oocysts released by specific hosts, i.e. felidae, and of cysts persisting in muscle cells of animals result in human toxoplasmosis. In the present review, we discuss recent new data on the cell biology of T. gondii and parasite diversity in animals. In addition, we focus on the impact of these various parasite strains and their different virulence on the clinical outcome of human congenital toxoplasmosis and T. gondii uveitis. Copyright © 2014 Elsevier GmbH. All rights reserved.
Davey, Heather M; Muscatello, David J; Wood, James G; Snelling, Thomas L; Ferson, Mark J; Macartney, Kristine K
2015-03-30
Australia was one of the first countries to introduce nationally funded rotavirus vaccination. The program has had a substantial impact on both rotavirus and all-cause acute gastroenteritis (AGE) hospitalisations and rotavirus laboratory tests. Evidence for an impact on Emergency Department (ED) presentations is limited. This study assessed changes in ED presentations for rotavirus in children aged <5 years in New South Wales, Australia, following introduction of monovalent human rotavirus vaccine (RV1, Rotarix(®), GlaxoSmithKline Australia Pty Ltd., Victoria, Australia). A time series analysis to examine trends in total non-admitted ED presentations for all-cause AGE and in the rotavirus-attributable fraction using data on rotavirus positive laboratory tests. A decline in the rate of non-admitted ED presentations for all-cause AGE was observed for all ages, being most notable in 1 year old children. Compared with the pre-vaccination period, we estimated the average weekly rate was lower across the first 4.5 years of the program for both all-cause AGE (18.3%; 70.5 versus 57.5 per 100,000 population) and rotavirus attributable (55.4%; 17.3 versus 7.7 per 100,000 population) presentations. In the fourth year of the program, estimated annual rotavirus attributable presentations were 77% lower than the pre-vaccination annual mean (996 versus 4300 per year). The program was associated with a substantial decline in rotavirus attributable non-admitted AGE presentations to ED among children aged <5 years. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
2016-01-01
Periodontal disease afflicts 20% of world population. This process usually occurs in the form of being lethargic and chronic, and consequently this disease is known as chronic process. All chronic diseases constantly cause activation of the immune system, and therefore the presentation of microbial peptides which are presented to lymphocytes by professional antigen presenting cells can present microbial peptides very similar to important structures of human economy causing autoimmune diseases, process known as molecular mimicry. Thus, the aim of this study was to verify the presence of molecular mimicry phenomenon between periodontopathogens and human proteins. Blasting microbes of Socransky periodontal complexes against human collagen were performed and then the proteins with similarities were modelled and were screened in the MHI binding virtual methods. The epitopes selected were produced and plasma of chronic periodontal volunteers was obtained and a dot immunobinding assay was performed. Hypothetical protein of Prevotella sp. and human collagen epitopes with high similarities were positive for dot immunobinding assay. With this result it can be suggested that the mimicry phenomena can occur on periodontal disease. PMID:28116146
Association of a Bacteriophage with Meningococcal Disease in Young Adults
Gray, Stephen J.; Kaczmarski, Edward B.; McCarthy, Noel D.; Nassif, Xavier; Maiden, Martin C. J.; Tinsley, Colin R.
2008-01-01
Despite being the agent of life-threatening meningitis, Neisseria meningitidis is usually carried asymptomatically in the nasopharynx of humans and only occasionally causes disease. The genetic bases for virulence have not been entirely elucidated and the search for new virulence factors in this species is hampered by the lack of an animal model representative of the human disease. As an alternative strategy we employ a molecular epidemiological approach to establish a statistical association of a candidate virulence gene with disease in the human population. We examine the distribution of a previously-identified genetic element, a temperate bacteriophage, in 1288 meningococci isolated from cases of disease and asymptomatic carriage. The phage was over-represented in disease isolates from young adults indicating that it may contribute to invasive disease in this age group. Further statistical analysis indicated that between 20% and 45% of the pathogenic potential of the five most common disease-causing meningococcal groups was linked to the presence of the phage. In the absence of an animal model of human disease, this molecular epidemiological approach permitted the estimation of the influence of the candidate virulence factor. Such an approach is particularly valuable in the investigation of exclusively human diseases. PMID:19065260
Nitrogen in the environment: sources, problems, and management.
Follett, R F; Hatfield, J L
2001-10-30
Nitrogen (N) is applied worldwide to produce food. It is in the atmosphere, soil, and water and is essential to all life. N for agriculture includes fertilizer, biologically fixed, manure, recycled crop residue, and soil-mineralized N. Presently, fertilizer N is a major source of N, and animal manure N is inefficiently used. Potential environmental impacts of N excreted by humans are increasing rapidly with increasing world populations. Where needed, N must be efficiently used because N can be transported immense distances and transformed into soluble and/or gaseous forms that pollute water resources and cause greenhouse effects. Unfortunately, increased amounts of gaseous N enter the environment as N2O to cause greenhouse warming and as NH3 to shift ecological balances of natural ecosystems. Large amounts of N are displaced with eroding sediments in surface waters. Soluble N in runoff or leachate water enters streams, rivers, and groundwater. High-nitrate drinking water can cause methemoglobinemia, while nitrosamines are associated with various human cancers. We describe the benefits, but also how N in the wrong form or place results in harmful effects on humans and animals, as well as to ecological and environmental systems.
Ji, Kaihua; Li, Qing; Shi, Yang; Xu, Chang; Wang, Yan; Du, Liqing
2017-01-01
Unplanned exposure to radiation can cause side effects on high-risk individuals; meanwhile, radiotherapies can also cause injury on normal cells and tissues surrounding the tumor. Besides the direct radiation damage, most of the ionizing radiation- (IR-) induced injuries were caused by generation of reactive oxygen species (ROS). Human mesenchymal stem cells (hMSCs), which possess self-renew and multilineage differentiation capabilities, are a critical population of cells to participate in the regeneration of IR-damaged tissues. Therefore, it is imperative to search effective radioprotectors for hMSCs. This study was to demonstrate whether natural source ginger oleoresin would mitigate IR-induced injuries in human mesenchymal stem cells (hMSCs). We demonstrated that ginger oleoresin could significantly reduce IR-induced cytotoxicity, ROS generation, and DNA strand breaks. In addition, the ROS-scavenging mechanism of ginger oleoresin was also investigated. The results showed that ginger oleoresin could induce the translocation of Nrf2 to cell nucleus and activate the expression of cytoprotective genes encoding for HO-1 and NQO-1. It suggests that ginger oleoresin has a potential role of being an effective antioxidant and radioprotective agent. PMID:29181121
The roles of vitamin D and cutaneous vitamin D production in human evolution and health.
Jablonski, Nina G; Chaplin, George
2018-03-29
Most of the vitamin D necessary for the maintenance of human health and successful reproduction is made in the skin under the influence of a narrow portion of the electromagnetic spectrum emitted from the sun, namely ultraviolet B radiation (UVB). During the course of human evolution, skin pigmentation has evolved to afford protection against high levels of UVR while still permitting cutaneous production of vitamin D. Similar pigmentation phenotypes evolved repeatedly as the result of independent genetic events when isolated human populations dispersed into habitats of extremely low or high UVB. The gradient of skin color seen in modern human populations is evidence of the operation of two clines, one favoring photoprotection near the equator, the other favoring vitamin D production nearer the poles. Through time, human adaptations to different solar regimes have become more cultural than biological. Rapid human migrations, increasing urbanization, and changes in lifestyle have created mismatches between skin pigmentation and environmental conditions leading to vitamin D deficiency. The prevalence and significance for health of vitamin D deficiencies, and the definition of optimal levels of vitamin D in the bloodstream are subjects of intense research and debate, but two of the causes of vitamin D deficiency - lack of sun exposure and abandonment of vitamin D rich foods in the diet - are traceable to changes in human lifestyles accompanying urbanization in prehistory. Copyright © 2018 Elsevier Inc. All rights reserved.
Implications of global climate change for housing, human settlements and public health.
Hales, Simon; Baker, Michael; Howden-Chapman, Philippa; Menne, Bettina; Woodruff, Rosalie; Woodward, Alistair
2007-01-01
Global climate change has profound implications for human societies. The present---ecologically unsustainable--trajectory of human development fails to provide for the basic needs of a substantial fraction of the global population, while diminishing the prospects for future generations. Human-caused climate change has already begun to affect weather patterns, physical and biological phenomena, and vulnerable human communities. Because the social processes of production and consumption have their own momentum, and because carbon dioxide has a long atmospheric lifetime, further climate change is inevitable over the coming century, even allowing for the adoption of mitigation measures. This situation implies that we should also try to reduce, and where possible to prevent, the adverse effects of climate changes by planned adaptation. Will human settlements be able to provide a healthy living environment and shelter from extreme climate events, such as cyclones and heat waves? In this paper, we review the nexus between human health, climate change, and the planning of housing and human settlements. We conclude that adapting to a rapidly changing global environment will be a major challenge, in the context of increasing population and per capita consumption, without increasing pressures on natural systems. Energy-efficient cities and the creation of opportunities for poor countries will be important elements of people centered, ecologically sustainable, development in the twenty-first century.
Carmena, David; Cardona, Guillermo A
2014-05-28
Echinococcosis is a zoonosis caused by helminths of the genus Echinococcus. The infection, one of the 17 neglected tropical diseases listed by the World Health Organization, has a cosmopolitan distribution and can be transmitted through a variety of domestic, synanthropic, and sylvatic cycles. Wildlife has been increasingly regarded as a relevant source of infection to humans, as demonstrated by the fact that a significant proportion of human emerging infectious diseases have a wildlife origin. Based on available epidemiological and molecular evidence, of the nine Echinococcus species currently recognized as valid taxa, E. canadensis G8-G10, E. felidis, E. multilocularis, E. oligarthrus, E. shiquicus, and E. vogeli are primarily transmitted in the wild. E. canadensis G6-G7, E. equinus, E. granulosus s.s., and E. ortleppi are considered to be transmitted mainly through domestic cycles. We summarize here current knowledge on the global epidemiology, geographical distribution and genotype frequency of Echinococcus spp. in wild carnivorous species. Topics addressed include the significance of the wildlife/livestock/human interface, the sympatric occurrence of different Echinococcus species in a given epidemiological scenario, and the role of wildlife as natural reservoir of disease to human and domestic animal populations. We have also discussed the impact that human activity and intervention may cause in the transmission dynamics of echinococcosis, including the human population expansion an encroachment on shrinking natural habitats, the increasing urbanization of wildlife carnivorous species and the related establishment of synanthropic cycles of Echinococcus spp., the land use (e.g. deforestation and agricultural practices), and the unsupervised international trade and translocation of wildlife animals. Following the 'One Health' approach, we have also emphasized that successful veterinary public health interventions in the field of echinococcosis requires an holistic approach to integrate current knowledge on human medicine, veterinary medicine and environmental sciences. Copyright © 2014 Elsevier B.V. All rights reserved.
Taravella, Angela M.; Bustamante, Carlos D.; Sikora, Martin
2017-01-01
The human DARC (Duffy antigen receptor for chemokines) gene encodes a membrane-bound chemokine receptor crucial for the infection of red blood cells by Plasmodium vivax, a major causative agent of malaria. Of the three major allelic classes segregating in human populations, the FY*O allele has been shown to protect against P. vivax infection and is at near fixation in sub-Saharan Africa, while FY*B and FY*A are common in Europe and Asia, respectively. Due to the combination of strong geographic differentiation and association with malaria resistance, DARC is considered a canonical example of positive selection in humans. Despite this, details of the timing and mode of selection at DARC remain poorly understood. Here, we use sequencing data from over 1,000 individuals in twenty-one human populations, as well as ancient human genomes, to perform a fine-scale investigation of the evolutionary history of DARC. We estimate the time to most recent common ancestor (TMRCA) of the most common FY*O haplotype to be 42 kya (95% CI: 34–49 kya). We infer the FY*O null mutation swept to fixation in Africa from standing variation with very low initial frequency (0.1%) and a selection coefficient of 0.043 (95% CI:0.011–0.18), which is among the strongest estimated in the human genome. We estimate the TMRCA of the FY*A mutation in non-Africans to be 57 kya (95% CI: 48–65 kya) and infer that, prior to the sweep of FY*O, all three alleles were segregating in Africa, as highly diverged populations from Asia and ≠Khomani San hunter-gatherers share the same FY*A haplotypes. We test multiple models of admixture that may account for this observation and reject recent Asian or European admixture as the cause. PMID:28282382
Adeola, O A; Olugasa, B O; Emikpe, B O
2016-03-01
Since the first detection of human H3N2 influenza virus in Taiwanese pigs in 1970, infection of pigs with wholly human viruses has been known to occur in other parts of the world. These viruses, referred to as human-like H3N2 viruses, have been known to cause clinical and subclinical infections of swine populations. Due to the paucity and complete unavailability of information on transmission of influenza viruses from other species, especially humans, to swine in Nigeria and Ghana, respectively, this study was designed to investigate the presence and prevalence of a human strain of influenza A (H3N2) in swine populations at three locations in two cities within these two West African countries in January and February, 2014. Using stratified random technique, nasal swab specimens were collected from seventy-five (75) pigs at two locations in Ibadan, Nigeria and from fifty (50) pigs in Kumasi, Ghana. These specimens were tested directly by a sensitive Quantitative Solid Phase Antigen-detection Sandwich ELISA using anti-A/Brisbane/10/2007 haemagglutinin monoclonal antibody. Influenza virus A/Brisbane/10/2007 (H3N2) was detected among pigs at the three study locations, with an aggregate prevalence of 4.0% for the two locations in Ibadan, Nigeria and also 4.0% for Kumasi, Ghana. Transmission of influenza viruses from other species to swine portends serious sinister prospects for genetic reassortment and evolvement of novel viruses. We therefore recommend that further studies should be carried out to investigate the presence of other circulating human and avian influenza viruses in swine populations in West Africa and also determine the extent of genetic reassortment of strains circulating among these pigs. This would provide an early warning system for detection of novel influenza viruses, which could have pandemic potentials. © 2015 Blackwell Verlag GmbH.
Protection against trichothecene mycotoxins
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1983-01-01
Trichothecenes and their effects on humans have attracted national and international attention because of their reported use in warfare. This study arose out of a concern about such uses and the potential harm these substances could cause among civilian and military populations that might be exposed to them. Accordingly, this report is intended to assist in the protection not only of U.S. Armed Forces against the adverse effects of trichothecenes but also of civilian populations that may come into contact with these toxins during peace or war. The committee concentrated on the following two major objectives: (1) examination of themore » environmental and biological behavior of the trichothecene class of mycotoxins to determine what protective measures can be taken and (2) development of the means for optimizing the protection of human beings against the effects of trichothecenes through appropriate prophylaxes and treatments.« less
Ecology and epidemiology of Echinococcus multilocularis in Europe.
Deplazes, P
2006-06-01
Human alveolar echinococcosis (AE), caused by the larval stage of Echinococcus multilocularis has a high mortality rate in untreated patients. The life-cycle of E. multilocularis in Europe predominantly involves foxes as definitive hosts. However, experimental studies demonstrated a comparable biotic potential of E. multilocularis in dogs and raccoon dogs but an insignificant potential in cats. AE occurs in central and eastern Europe at low incidence rates. Recent studies in foxes have shown that E. multilocularis has a wider geographic range (including Italy) than previously thought. In recent years, increases in fox populations have been observed in many European countries, especially in urban areas. As a result, the E. multilocularis cycle is now established in the urban environment. This presents an increased risk of infection for a large human population. Based on these facts and new epidemiological data, possible intervention strategies are presented.
A comprehensive monitoring program for North American shorebirds
Howe, Marshall; Bart, Jon; Brown, Stephen; Elphick, Chris; Gill, Robert E.; Harrington, Brian A.; Hickey, Catherine; Morrison, Guy; Skagen, Susan K.; Warnock, Nils
2000-01-01
Anthropogenic changes to the biosphere, including widespread degradation and losses of habitats and ecosystems, are causing rapid and profound changes to bird and other wildlife populations throughout the world. Such changes have led to increasing risks and rates of extinction. As a consequence, information on how bird populations are changing is becoming increasingly important to wildlife conservationists and managers. Early detection of population change is crucial for setting wildlife planning and management priorities. For example, information on population size, population vulnerability, and population change has been central to international conservation strategies such as the Ramsar Convention, the Western Hemisphere (Bonn) Convention, and the Western Hemisphere Shorebird Reserve Network. Measuring population size or change is also crucial for evaluating the effectiveness of population management programs implemented by wildlife agencies both locally and regionally.Although the concept of determining population size is simple, practical difficulties can be enormous and costly to overcome. In the United States, $4 billion will be spent in year 2000 to census the human population, possibly one of the most easily counted of all vertebrates. By contrast, the portion of the FY 2000 budget of the U.S. Department of the Interior allotted for tracking populations of all migratory birds (> 600 species) is less than $5 million (.0125% of the human census figure). This falls far short of the amount required to provide adequate, science-based information about bird populations and population change to wildlife managers.The gap between current ability and need is especially noteworthy for shorebirds. There are 72 species, subspecies, or distinct populations of shorebirds in North America. Even though most of these have received less conservation attention than such groups as waterfowl, colonial waterbirds, or songbirds, recent independent evaluation of data collected for other purposes in the eastern United States and Canada during the 1970s and early 1980s showed that 16 of 26 species surveyed are apparently declining, some at rates exceeding 5% per year (Howe et al., 1989). Except for one increasing species, populations of the other 9 species were statistically unchanged over the time period analyzed. In most cases causes of shorebird population declines are poorly known. For some species, the declines may be part of natural population cycles. For others the changes may reflect deterioration of conditions on the nesting grounds, at migration stopover locations, in wintering zones, or combinations of these. Determining which of these scenarios is correct and what management actions, if any, are warranted will be possible only after implementing a comprehensive monitoring plan such as that described here
Bodel, P; Ralph, P; Wenc, K; Long, J C
1980-02-01
Fever not explained by infection may occur in patients with malignant lymphoma presumably caused by a release of endogenous pyrogen. Although pyrogen has been found in some tumors with a mixed cell population, production of endogenous pyrogen by the neoplastic cells has not been demonstrated. This report documents the apparently spontaneous synthesis and release of such pyrogen by two human tumor cell lines derived from patients with Hodgkin's disease and histiocytic lymphoma. The endogenous pyrogen from the two cell lines was similar and closely resembled that produced by normal human monocytes in antigenic properties as well as heat and pronase sensitivity. The Hodgkin's disease and histiocytic lymphoma cell lines do not require specific stimulation for the production of endogenous pyrogen suggesting that the mechanism of pyrogen release by neoplastic macrophage-related cells differs from that of normal phagocytic cells. The tumor-associated fever in some patients with malignant lymphoma may be caused by a release of endogenous pyrogen by proliferating neoplastic cells.
Bodel, P; Ralph, P; Wenc, K; Long, J C
1980-01-01
Fever not explained by infection may occur in patients with malignant lymphoma presumably caused by a release of endogenous pyrogen. Although pyrogen has been found in some tumors with a mixed cell population, production of endogenous pyrogen by the neoplastic cells has not been demonstrated. This report documents the apparently spontaneous synthesis and release of such pyrogen by two human tumor cell lines derived from patients with Hodgkin's disease and histiocytic lymphoma. The endogenous pyrogen from the two cell lines was similar and closely resembled that produced by normal human monocytes in antigenic properties as well as heat and pronase sensitivity. The Hodgkin's disease and histiocytic lymphoma cell lines do not require specific stimulation for the production of endogenous pyrogen suggesting that the mechanism of pyrogen release by neoplastic macrophage-related cells differs from that of normal phagocytic cells. The tumor-associated fever in some patients with malignant lymphoma may be caused by a release of endogenous pyrogen by proliferating neoplastic cells. PMID:6985918
Old World Hantaviruses in Rodents in New Orleans, Louisiana
Cross, Robert W.; Waffa, Bradley; Freeman, Ashley; Riegel, Claudia; Moses, Lina M.; Bennett, Andrew; Safronetz, David; Fischer, Elizabeth R.; Feldmann, Heinz; Voss, Thomas G.; Bausch, Daniel G.
2014-01-01
Seoul virus, an Old World hantavirus, is maintained in brown rats and causes a mild form of hemorrhagic fever with renal syndrome (HFRS) in humans. We captured rodents in New Orleans, Louisiana and tested them for the presence of Old World hantaviruses by reverse transcription polymerase chain reaction (RT-PCR) with sequencing, cell culture, and electron microscopy; 6 (3.4%) of 178 rodents captured—all brown rats—were positive for a Seoul virus variant previously coined Tchoupitoulas virus, which was noted in rodents in New Orleans in the 1980s. The finding of Tchoupitoulas virus in New Orleans over 25 years since its first discovery suggests stable endemicity in the city. Although the degree to which this virus causes human infection and disease remains unknown, repeated demonstration of Seoul virus in rodent populations, recent cases of laboratory-confirmed HFRS in some US cities, and a possible link with hypertensive renal disease warrant additional investigation in both rodents and humans. PMID:24639295
Old World hantaviruses in rodents in New Orleans, Louisiana.
Cross, Robert W; Waffa, Bradley; Freeman, Ashley; Riegel, Claudia; Moses, Lina M; Bennett, Andrew; Safronetz, David; Fischer, Elizabeth R; Feldmann, Heinz; Voss, Thomas G; Bausch, Daniel G
2014-05-01
Seoul virus, an Old World hantavirus, is maintained in brown rats and causes a mild form of hemorrhagic fever with renal syndrome (HFRS) in humans. We captured rodents in New Orleans, Louisiana and tested them for the presence of Old World hantaviruses by reverse transcription polymerase chain reaction (RT-PCR) with sequencing, cell culture, and electron microscopy; 6 (3.4%) of 178 rodents captured--all brown rats--were positive for a Seoul virus variant previously coined Tchoupitoulas virus, which was noted in rodents in New Orleans in the 1980s. The finding of Tchoupitoulas virus in New Orleans over 25 years since its first discovery suggests stable endemicity in the city. Although the degree to which this virus causes human infection and disease remains unknown, repeated demonstration of Seoul virus in rodent populations, recent cases of laboratory-confirmed HFRS in some US cities, and a possible link with hypertensive renal disease warrant additional investigation in both rodents and humans.
Genomic insights into the Ixodes scapularis tick vector of Lyme disease
Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.; Sonenshine, Daniel E.; Roe, R. Michael; Waterhouse, Robert M.; Sattelle, David B.; de la Fuente, José; Ribeiro, Jose M.; Megy, Karine; Thimmapuram, Jyothi; Miller, Jason R.; Walenz, Brian P.; Koren, Sergey; Hostetler, Jessica B.; Thiagarajan, Mathangi; Joardar, Vinita S.; Hannick, Linda I.; Bidwell, Shelby; Hammond, Martin P.; Young, Sarah; Zeng, Qiandong; Abrudan, Jenica L.; Almeida, Francisca C.; Ayllón, Nieves; Bhide, Ketaki; Bissinger, Brooke W.; Bonzon-Kulichenko, Elena; Buckingham, Steven D.; Caffrey, Daniel R.; Caimano, Melissa J.; Croset, Vincent; Driscoll, Timothy; Gilbert, Don; Gillespie, Joseph J.; Giraldo-Calderón, Gloria I.; Grabowski, Jeffrey M.; Jiang, David; Khalil, Sayed M. S.; Kim, Donghun; Kocan, Katherine M.; Koči, Juraj; Kuhn, Richard J.; Kurtti, Timothy J.; Lees, Kristin; Lang, Emma G.; Kennedy, Ryan C.; Kwon, Hyeogsun; Perera, Rushika; Qi, Yumin; Radolf, Justin D.; Sakamoto, Joyce M.; Sánchez-Gracia, Alejandro; Severo, Maiara S.; Silverman, Neal; Šimo, Ladislav; Tojo, Marta; Tornador, Cristian; Van Zee, Janice P.; Vázquez, Jesús; Vieira, Filipe G.; Villar, Margarita; Wespiser, Adam R.; Yang, Yunlong; Zhu, Jiwei; Arensburger, Peter; Pietrantonio, Patricia V.; Barker, Stephen C.; Shao, Renfu; Zdobnov, Evgeny M.; Hauser, Frank; Grimmelikhuijzen, Cornelis J. P.; Park, Yoonseong; Rozas, Julio; Benton, Richard; Pedra, Joao H. F.; Nelson, David R.; Unger, Maria F.; Tubio, Jose M. C.; Tu, Zhijian; Robertson, Hugh M.; Shumway, Martin; Sutton, Granger; Wortman, Jennifer R.; Lawson, Daniel; Wikel, Stephen K.; Nene, Vishvanath M.; Fraser, Claire M.; Collins, Frank H.; Birren, Bruce; Nelson, Karen E.; Caler, Elisabet; Hill, Catherine A.
2016-01-01
Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick–host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host ‘questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent. PMID:26856261
Genomic insights into the Ixodes scapularis tick vector of Lyme disease.
Gulia-Nuss, Monika; Nuss, Andrew B; Meyer, Jason M; Sonenshine, Daniel E; Roe, R Michael; Waterhouse, Robert M; Sattelle, David B; de la Fuente, José; Ribeiro, Jose M; Megy, Karine; Thimmapuram, Jyothi; Miller, Jason R; Walenz, Brian P; Koren, Sergey; Hostetler, Jessica B; Thiagarajan, Mathangi; Joardar, Vinita S; Hannick, Linda I; Bidwell, Shelby; Hammond, Martin P; Young, Sarah; Zeng, Qiandong; Abrudan, Jenica L; Almeida, Francisca C; Ayllón, Nieves; Bhide, Ketaki; Bissinger, Brooke W; Bonzon-Kulichenko, Elena; Buckingham, Steven D; Caffrey, Daniel R; Caimano, Melissa J; Croset, Vincent; Driscoll, Timothy; Gilbert, Don; Gillespie, Joseph J; Giraldo-Calderón, Gloria I; Grabowski, Jeffrey M; Jiang, David; Khalil, Sayed M S; Kim, Donghun; Kocan, Katherine M; Koči, Juraj; Kuhn, Richard J; Kurtti, Timothy J; Lees, Kristin; Lang, Emma G; Kennedy, Ryan C; Kwon, Hyeogsun; Perera, Rushika; Qi, Yumin; Radolf, Justin D; Sakamoto, Joyce M; Sánchez-Gracia, Alejandro; Severo, Maiara S; Silverman, Neal; Šimo, Ladislav; Tojo, Marta; Tornador, Cristian; Van Zee, Janice P; Vázquez, Jesús; Vieira, Filipe G; Villar, Margarita; Wespiser, Adam R; Yang, Yunlong; Zhu, Jiwei; Arensburger, Peter; Pietrantonio, Patricia V; Barker, Stephen C; Shao, Renfu; Zdobnov, Evgeny M; Hauser, Frank; Grimmelikhuijzen, Cornelis J P; Park, Yoonseong; Rozas, Julio; Benton, Richard; Pedra, Joao H F; Nelson, David R; Unger, Maria F; Tubio, Jose M C; Tu, Zhijian; Robertson, Hugh M; Shumway, Martin; Sutton, Granger; Wortman, Jennifer R; Lawson, Daniel; Wikel, Stephen K; Nene, Vishvanath M; Fraser, Claire M; Collins, Frank H; Birren, Bruce; Nelson, Karen E; Caler, Elisabet; Hill, Catherine A
2016-02-09
Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick-host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host 'questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent.
Effects of essential amino acids on lipid metabolism in mice and humans.
Xiao, Fei; Du, Ying; Lv, Ziquan; Chen, Shanghai; Zhu, Jianmin; Sheng, Hongguang; Guo, Feifan
2016-11-01
Eight amino acids are considered essential for human nutrition, and three of them, including leucine, isoleucine and valine, are called as branched-chain amino acids (BCAAs). We recently discovered that dietary deficiency of any BCAA for 7 days rapidly reduces the abdominal fat mass in mice. The goal of this study was to investigate (1) whether dietary deficiency of the other five essential amino acids (EAAs), including phenylalanine, threonine, tryptophan, methionine and lysine, would produce similar effects and (2) whether an association between serum AAs and obesity was observed in humans in Chinese Han population. Similar to BCAAs deprivation, dietary deficiency of any of these five EAAs for 7 days significantly reduced abdominal fat mass, which is likely caused by increased energy expenditure. Expression of genes and proteins related to lipolysis, however, were differentially regulated by different EAAs. These results suggest a crucial role of EAAs deprivation on lipid metabolism in mice. Our human studies revealed that levels of four EAAs (leucine, isoleucine, valine and phenylalanine) were elevated in obese humans compared with those in lean controls in Chinese Han population. Based on the results obtained from mice, we speculate that these four EAAs might play important roles in human obesity. © 2016 Society for Endocrinology.
Effects of economics and demographics on global fisheries sustainability.
Ding, Qi; Wang, Yali; Chen, Xinjun; Chen, Yong
2017-08-01
A good understanding of social factors that lead to marine ecological change is important to developing sustainable global fisheries. We used balanced panel models and conducted cross-national time-series analyses (1970-2010) of 122 nations to examine how economic prosperity and population growth affected the sustainability of marine ecosystems. We used catches in economic exclusive zone (EEZ); mean trophic level of fishery landings (MTL); primary production required to sustain catches (expressed as percentage of local primary production [%PPR]); and an index of ecosystem overfishing (i.e., the loss in secondary production index [L index]) as indicators of ecological change in marine ecosystems. The EEZ catch, %PPR, and L index declined gradually after gross domestic product (GDP) per capita reached $15,000, $14,000, and $19,000, respectively, and MTL increased steadily once GDP per capita exceeded $20,000. These relationships suggest that economic growth and biodiversity conservation are compatible goals. However, increasing human populations would degrade marine ecosystems. Specifically, a doubling of human population caused an increase in the %PPR of 17.1% and in the L index of 0.0254 and a decline in the MTL of 0.176. A 1% increase in human population resulted in a 0.744% increase in EEZ catch. These results highlight the importance of considering social and economic factors in developing sustainable fisheries management policy. © 2016 Society for Conservation Biology.
Spatio-temporal Genetic Structuring of Leishmania major in Tunisia by Microsatellite Analysis
Harrabi, Myriam; Bettaieb, Jihène; Ghawar, Wissem; Toumi, Amine; Zaâtour, Amor; Yazidi, Rihab; Chaâbane, Sana; Chalghaf, Bilel; Hide, Mallorie; Bañuls, Anne-Laure; Ben Salah, Afif
2015-01-01
In Tunisia, cases of zoonotic cutaneous leishmaniasis caused by Leishmania major are increasing and spreading from the south-west to new areas in the center. To improve the current knowledge on L. major evolution and population dynamics, we performed multi-locus microsatellite typing of human isolates from Tunisian governorates where the disease is endemic (Gafsa, Kairouan and Sidi Bouzid governorates) and collected during two periods: 1991–1992 and 2008–2012. Analysis (F-statistics and Bayesian model-based approach) of the genotyping results of isolates collected in Sidi Bouzid in 1991–1992 and 2008–2012 shows that, over two decades, in the same area, Leishmania parasites evolved by generating genetically differentiated populations. The genetic patterns of 2008–2012 isolates from the three governorates indicate that L. major populations did not spread gradually from the south to the center of Tunisia, according to a geographical gradient, suggesting that human activities might be the source of the disease expansion. The genotype analysis also suggests previous (Bayesian model-based approach) and current (F-statistics) flows of genotypes between governorates and districts. Human activities as well as reservoir dynamics and the effects of environmental changes could explain how the disease progresses. This study provides new insights into the evolution and spread of L. major in Tunisia that might improve our understanding of the parasite flow between geographically and temporally distinct populations. PMID:26302440
Giustina, L D; Luz, L N; Vieira, F S; Rossi, F S; Soares-Lopes, C R A; Pereira, T N S; Rossi, A A B
2014-02-14
The genus Theobroma found in the Amazon region is composed of 22 species, including Theobroma speciosum, better known as cacauí. These species are constantly threatened by forest fragmentation caused by human activities and require conservation strategies and management aimed at preserving them in their natural environments. The main objective of this study was to analyze the population structure and genetic diversity within and between natural populations of T. speciosum by using ISSR molecular markers to understand the population structure of the species. Four natural populations belonging to the Amazon rainforest (BAC, CRO, FLA, and PNA), located in the State of Mato Grosso, were selected. Amplification reactions were performed using 15 ISSR primers. A total of 101 loci were found, of which 54.46% were polymorphic at the species level. The BAC population showed higher genetic diversity (H=0.095 and I=0.144) and higher percentage of polymorphism (28.71%). The populations showed an FST value of 0.604, indicating marked genetic differentiation. The highest genetic variation was found between populations. Gene flow was low between populations, indicating genetic isolation between populations.
A neuromechanical strategy for mediolateral foot placement in walking humans.
Rankin, Bradford L; Buffo, Stephanie K; Dean, Jesse C
2014-07-15
Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state of the contralateral stance leg. Participants walked under Unperturbed and Perturbed conditions, in which foot placement was intermittently perturbed by moving the right leg medially or laterally during the swing phase (by ∼50-100 mm). We quantified mediolateral foot placement, electromyographic activity of frontal-plane hip muscles, and stance leg mechanical state. During Unperturbed walking, greater swing-phase gluteus medius (GM) activity was associated with more lateral foot placement. Increases in GM activity were most strongly predicted by increased mediolateral displacement between the center of mass (CoM) and the contralateral stance foot. The Perturbed walking results indicated a causal relationship between stance leg mechanics and swing-phase GM activity. Perturbations that reduced the mediolateral CoM displacement from the stance foot caused reductions in swing-phase GM activity and more medial foot placement. Conversely, increases in mediolateral CoM displacement caused increased swing-phase GM activity and more lateral foot placement. Under both Unperturbed and Perturbed conditions, humans controlled their mediolateral foot placement by modulating swing-phase muscle activity in response to the mechanical state of the contralateral leg. This strategy may be disrupted in clinical populations with a reduced ability to modulate muscle activity or sense their body's mechanical state.
Determinants of glycan receptor specificity of H2N2 influenza A virus hemagglutinin.
Viswanathan, Karthik; Koh, Xiaoying; Chandrasekaran, Aarthi; Pappas, Claudia; Raman, Rahul; Srinivasan, Aravind; Shriver, Zachary; Tumpey, Terrence M; Sasisekharan, Ram
2010-10-29
The H2N2 subtype of influenza A virus was responsible for the Asian pandemic of 1957-58. However, unlike other subtypes that have caused pandemics such as H1N1 and H3N2, which continue to circulate among humans, H2N2 stopped circulating in the human population in 1968. Strains of H2 subtype still continue to circulate in birds and occasionally pigs and could be reintroduced into the human population through antigenic drift or shift. Such an event is a potential global health concern because of the waning population immunity to H2 hemagglutinin (HA). The first step in such a cross-species transmission and human adaptation of influenza A virus is the ability for its surface glycoprotein HA to bind to glycan receptors expressed in the human upper respiratory epithelia. Recent structural and biochemical studies have focused on understanding the glycan receptor binding specificity of the 1957-58 pandemic H2N2 HA. However, there has been considerable HA sequence divergence in the recent avian-adapted H2 strains from the pandemic H2N2 strain. Using a combination of structural modeling, quantitative glycan binding and human respiratory tissue binding methods, we systematically identify mutations in the HA from a recent avian-adapted H2N2 strain (A/Chicken/PA/2004) that make its quantitative glycan receptor binding affinity (defined using an apparent binding constant) comparable to that of a prototypic pandemic H2N2 (A/Albany/6/58) HA.
Determinants of Glycan Receptor Specificity of H2N2 Influenza A Virus Hemagglutinin
Chandrasekaran, Aarthi; Pappas, Claudia; Raman, Rahul; Srinivasan, Aravind; Shriver, Zachary; Tumpey, Terrence M.; Sasisekharan, Ram
2010-01-01
The H2N2 subtype of influenza A virus was responsible for the Asian pandemic of 1957-58. However, unlike other subtypes that have caused pandemics such as H1N1 and H3N2, which continue to circulate among humans, H2N2 stopped circulating in the human population in 1968. Strains of H2 subtype still continue to circulate in birds and occasionally pigs and could be reintroduced into the human population through antigenic drift or shift. Such an event is a potential global health concern because of the waning population immunity to H2 hemagglutinin (HA). The first step in such a cross-species transmission and human adaptation of influenza A virus is the ability for its surface glycoprotein HA to bind to glycan receptors expressed in the human upper respiratory epithelia. Recent structural and biochemical studies have focused on understanding the glycan receptor binding specificity of the 1957-58 pandemic H2N2 HA. However, there has been considerable HA sequence divergence in the recent avian-adapted H2 strains from the pandemic H2N2 strain. Using a combination of structural modeling, quantitative glycan binding and human respiratory tissue binding methods, we systematically identify mutations in the HA from a recent avian-adapted H2N2 strain (A/Chicken/PA/2004) that make its quantitative glycan receptor binding affinity (defined using an apparent binding constant) comparable to that of a prototypic pandemic H2N2 (A/Albany/6/58) HA. PMID:21060797
Larsen, Thomas; Hunt, Terry; Lipo, Carl; Solsvik, Reidar; Wallsgrove, Natalie; Ka'apu‐Lyons, Cassie; Close, Hilary G.; Popp, Brian N.
2017-01-01
Abstract Objectives The Rapa Nui “ecocide” narrative questions whether the prehistoric population caused an avoidable ecological disaster through rapid deforestation and over‐exploitation of natural resources. The objective of this study was to characterize prehistoric human diets to shed light on human adaptability and land use in an island environment with limited resources. Materials and methods Materials for this study included human, faunal, and botanical remains from the archaeological sites Anakena and Ahu Tepeu on Rapa Nui, dating from c. 1400 AD to the historic period, and modern reference material. We used bulk carbon and nitrogen isotope analyses and amino acid compound specific isotope analyses (AA‐CSIA) of collagen isolated from prehistoric human and faunal bone, to assess the use of marine versus terrestrial resources and to investigate the underlying baseline values. Similar isotope analyses of archaeological and modern botanical and marine samples were used to characterize the local environment. Results Results of carbon and nitrogen AA‐CSIA independently show that around half the protein in diets from the humans measured came from marine sources; markedly higher than previous estimates. We also observed higher δ15N values in human collagen than could be expected from the local environment. Discussion Our results suggest highly elevated δ15N values could only have come from consumption of crops grown in substantially manipulated soils. These findings strongly suggest that the prehistoric population adapted and exhibited astute environmental awareness in a harsh environment with nutrient poor soils. Our results also have implications for evaluating marine reservoir corrections of radiocarbon dates. PMID:28664976
Khasnatinov, Maxim Anatolyevich; Liapunov, Alexander Valeryevich; Manzarova, Ellina Lopsonovna; Kulakova, Nina Viktorovna; Petrova, Irina Viktorovna; Danchinova, Galina Anatolyevna
2016-02-01
Hard ticks are the vectors of many pathogens including tick-borne encephalitis virus and the Lyme disease agent Borrelia burgdorferi sensu lato. In Eastern Siberia, Ixodes persulcatus, Dermacentor nuttalli, Dermacentor silvarum and Haemaphysalis concinna are regarded as aggressive to humans. Recently, significant changes in world tick fauna have been reported and this affects the spread of tick-borne pathogens. We studied the current species diversity, population structure and prevalence of tick-borne pathogens of hard ticks (Acari: Ixodidae) that attacked humans in Eastern Siberia (Irkutsk region, Russia). In total, 31,892 individual ticks were identified and analysed during the years 2007-2014. The majority (85.4%) of victims was bitten by I. persulcatus, 14.55% of attacks on humans were caused by D. nuttalli and D. silvarum, whereas H. concinna was documented only in 15 cases (0.05%). The seasonal activity and the age/gender structure of the tick population were studied as well. Among all the studied ticks, three unconventional species, i.e. Rhipicephalus sanguineus, Dermacentor reticulatus and Amblyomma americanum, were identified. Analysis of tick bite histories indicates at least three events of invasion of non-endemic ticks into the ecosystems of northern Eurasia with harsh continental climates. Invading ticks are able to reach the adult life stage and are aggressive to the local human population. Phylogenetic analysis of mt 16S rRNA gene fragments suggests multiple independent routes of tick migration to Eastern Siberia. Possible implications to human health and epidemiology of tick-borne infections are discussed.
Jarman, Catrine L; Larsen, Thomas; Hunt, Terry; Lipo, Carl; Solsvik, Reidar; Wallsgrove, Natalie; Ka'apu-Lyons, Cassie; Close, Hilary G; Popp, Brian N
2017-10-01
The Rapa Nui "ecocide" narrative questions whether the prehistoric population caused an avoidable ecological disaster through rapid deforestation and over-exploitation of natural resources. The objective of this study was to characterize prehistoric human diets to shed light on human adaptability and land use in an island environment with limited resources. Materials for this study included human, faunal, and botanical remains from the archaeological sites Anakena and Ahu Tepeu on Rapa Nui, dating from c. 1400 AD to the historic period, and modern reference material. We used bulk carbon and nitrogen isotope analyses and amino acid compound specific isotope analyses (AA-CSIA) of collagen isolated from prehistoric human and faunal bone, to assess the use of marine versus terrestrial resources and to investigate the underlying baseline values. Similar isotope analyses of archaeological and modern botanical and marine samples were used to characterize the local environment. Results of carbon and nitrogen AA-CSIA independently show that around half the protein in diets from the humans measured came from marine sources; markedly higher than previous estimates. We also observed higher δ 15 N values in human collagen than could be expected from the local environment. Our results suggest highly elevated δ 15 N values could only have come from consumption of crops grown in substantially manipulated soils. These findings strongly suggest that the prehistoric population adapted and exhibited astute environmental awareness in a harsh environment with nutrient poor soils. Our results also have implications for evaluating marine reservoir corrections of radiocarbon dates. © 2017 Wiley Periodicals, Inc.
Neglected parasitic infections in the United States: toxocariasis.
Woodhall, Dana M; Eberhard, Mark L; Parise, Monica E
2014-05-01
Toxocariasis is a preventable parasitic disease that is caused by the dog and cat roundworms Toxocara cani and T. cati, respectively. Humans become infected when they accidently ingest infectious Toxocara eggs commonly found in contaminated soil; children are most often affected. Clinical manifestations of Toxocara infection in humans include ocular toxocariasis and visceral toxocariasis. Although infection with Toxocara can cause devastating disease, the burden of toxocariasis in the United States population remains unknown. In addition, risk factors for acquiring infection need to be better defined, and research needs to be conducted to better understand the pathophysiology and clinical course of toxocariasis. Development of diagnostic tests would enable clinicians to detect active infection, and determination of optimal drug regiments would ensure patients were appropriately treated. Addressing these public health gaps is necessary to understand and address the impact of toxocariasis in the United States.
Oudni-M'rad, Myriam; Cabaret, Jacques; M'rad, Selim; Chaâbane-Banaoues, Raja; Mekki, Mongi; Zmantar, Sofien; Nouri, Abdellatif; Mezhoud, Habib; Babba, Hamouda
2016-10-01
G1 genotype of Echinococcus granulosus sensu stricto is the major cause of hydatidosis in Northern Africa, Tunisia included. The genetic relationship between lung and liver localization were studied in ovine, bovine and human hydatid cysts in Tunisia. Allozyme variation and single strand conformation polymorphism were used for genetic differentiation. The first cause of genetic differentiation was the host species and the second was the localization (lung or liver). The reticulated genetic relationship between the liver or the lung human isolates and isolates from bovine lung, is indicative of recombination (sexual reproduction) or lateral genetic transfer. The idea of two specialized populations (one for the lung one for the liver) that are more or less successful according to host susceptibility is thus proposed. Copyright © 2016 Elsevier B.V. All rights reserved.
Skouloudis, Andreas N; Kassomenos, Pavlos
2014-08-01
The use of emerging technologies for environmental monitoring with satellite and in-situ sensors have become essential instruments for assessing the impact of environmental pollution on human health, especially in areas that require high spatial and temporal resolution. This was until recently a rather difficult problem. Regrettably, with classical approaches the spatial resolution is frequently inadequate in reporting environmental causes and health effects in the same time scale. This work examines with new tools different levels of air-quality with sensor monitoring with the aim to associate those with severe health effects. The process established here facilitates the precise representation of human exposure with the population attributed in a fine spatial grid and taking into account environmental stressors of human exposure. These stressors can be monitored with innovative sensor units with a temporal resolution that accurately describes chronic and acute environmental burdens. The current understanding of the situation in densely populated areas can be properly analyzed, before commitments are made for reductions in total emissions as well as for assessing the effects of reduced trans-boundary fluxes. In addition, the data processed here with in-situ sensors can assist in establishing more effective regulatory policies for the protection of vulnerable population groups and the satellite monitoring instruments permit abatement strategies that are close to real-time over large geographical areas. Copyright © 2014 Elsevier B.V. All rights reserved.
Zoonotic diseases associated with free-roaming cats.
Gerhold, R W; Jessup, D A
2013-05-01
Free-roaming cat populations have been identified as a significant public health threat and are a source for several zoonotic diseases including rabies, toxoplasmosis, cutaneous larval migrans because of various nematode parasites, plague, tularemia and murine typhus. Several of these diseases are reported to cause mortality in humans and can cause other important health issues including abortion, blindness, pruritic skin rashes and other various symptoms. A recent case of rabies in a young girl from California that likely was transmitted by a free-roaming cat underscores that free-roaming cats can be a source of zoonotic diseases. Increased attention has been placed on trap-neuter-release (TNR) programmes as a viable tool to manage cat populations. However, some studies have shown that TNR leads to increased immigration of unneutered cats into neutered populations as well as increased kitten survival in neutered groups. These compensatory mechanisms in neutered groups leading to increased kitten survival and immigration would confound rabies vaccination campaigns and produce naïve populations of cats that can serve as source of zoonotic disease agents owing to lack of immunity. This manuscript is a review of the various diseases of free-roaming cats and the public health implications associated with the cat populations. © 2012 Blackwell Verlag GmbH.
Population exposure to hazardous air quality due to the 2015 fires in Equatorial Asia.
Crippa, P; Castruccio, S; Archer-Nicholls, S; Lebron, G B; Kuwata, M; Thota, A; Sumin, S; Butt, E; Wiedinmyer, C; Spracklen, D V
2016-11-16
Vegetation and peatland fires cause poor air quality and thousands of premature deaths across densely populated regions in Equatorial Asia. Strong El-Niño and positive Indian Ocean Dipole conditions are associated with an increase in the frequency and intensity of wildfires in Indonesia and Borneo, enhancing population exposure to hazardous concentrations of smoke and air pollutants. Here we investigate the impact on air quality and population exposure of wildfires in Equatorial Asia during Fall 2015, which were the largest over the past two decades. We performed high-resolution simulations using the Weather Research and Forecasting model with Chemistry based on a new fire emission product. The model captures the spatio-temporal variability of extreme pollution episodes relative to space- and ground-based observations and allows for identification of pollution sources and transport over Equatorial Asia. We calculate that high particulate matter concentrations from fires during Fall 2015 were responsible for persistent exposure of 69 million people to unhealthy air quality conditions. Short-term exposure to this pollution may have caused 11,880 (6,153-17,270) excess mortalities. Results from this research provide decision-relevant information to policy makers regarding the impact of land use changes and human driven deforestation on fire frequency and population exposure to degraded air quality.
Population exposure to hazardous air quality due to the 2015 fires in Equatorial Asia
Crippa, P.; Castruccio, S.; Archer-Nicholls, S.; Lebron, G. B.; Kuwata, M.; Thota, A.; Sumin, S.; Butt, E.; Wiedinmyer, C.; Spracklen, D. V.
2016-01-01
Vegetation and peatland fires cause poor air quality and thousands of premature deaths across densely populated regions in Equatorial Asia. Strong El-Niño and positive Indian Ocean Dipole conditions are associated with an increase in the frequency and intensity of wildfires in Indonesia and Borneo, enhancing population exposure to hazardous concentrations of smoke and air pollutants. Here we investigate the impact on air quality and population exposure of wildfires in Equatorial Asia during Fall 2015, which were the largest over the past two decades. We performed high-resolution simulations using the Weather Research and Forecasting model with Chemistry based on a new fire emission product. The model captures the spatio-temporal variability of extreme pollution episodes relative to space- and ground-based observations and allows for identification of pollution sources and transport over Equatorial Asia. We calculate that high particulate matter concentrations from fires during Fall 2015 were responsible for persistent exposure of 69 million people to unhealthy air quality conditions. Short-term exposure to this pollution may have caused 11,880 (6,153–17,270) excess mortalities. Results from this research provide decision-relevant information to policy makers regarding the impact of land use changes and human driven deforestation on fire frequency and population exposure to degraded air quality. PMID:27848989
Gonadotropin-Dependent Precocious Puberty: Neoplastic Causes and Endocrine Considerations
2011-01-01
Premature activation of the hypothalamic-pituitary-gonadal (HPG) axis manifests as gonadotropin-dependent precocious puberty. The mechanisms behind HPG activation are complex and a clear etiology for early activation is often not elucidated. Though collectively uncommon, the neoplastic and developmental causes of gonadotropin-dependent precocious puberty are very important to consider, as a delay in diagnosis may lead to adverse patient outcomes. The intent of the current paper is to review the neoplastic and developmental causes of gonadotropin-dependent precocious puberty. We discuss the common CNS lesions and human chorionic gonadotropin-secreting tumors that cause sexual precocity, review the relationship between therapeutic radiation and gonadotropin-dependent precocious puberty, and finally, provide an overview of the therapies available for height preservation in this unique patient population. PMID:21603196
We have AN Increasing Need to Model Ourselves
NASA Astrophysics Data System (ADS)
Farmer, J. Doyne
Pierre Teilhard de Chardin referred to the fusion of biological life, human culture, and technology as the noosphere. Technological improvement is causing the noosphere to evolve rapidly, driving the enormous increase in human population over the last 10,000 years and the transformation (and devastation) of the biosphere. The rapid proliferation of the internet is changing human culture, including everything from the way we find mates to the way democracy functions, or fails to function. The emergence of the BINC (Bio, Info, Nano, Cogno) technologies promises to further accelerate this change. We are acquiring an ever-increasing ability to engineer devices at a molecular level, to control the genome, and to create new forms of life and intelligence...
In vitro effect of fenthion on human lymphocytes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rani, M.V.U.; Rao, M.S.
1991-08-01
Fenthion is an organophosphorus insecticide which is extensively used in control of leaf hoppers, cutworms, mites on vegetable crops. It has been reported that organophosphorus pesticides cause a significant increase in sister chromatid exchanges in mammalian cell lines. A significant increase of chromosomal aberrations has been reported in rural population exposed to pesticides. Organosphosphorus pesticides malathion, diazinon, dimethoate, phosdrin and dursban induced sister chromatid exchanges in human lymphoid cells. Exchange type of aberration has been reported in fluoriculturist who were exposed to organophosphorus, organochlorine pesticides. In the present investigation an attempt has been made to evaluate the cytogenetic effect ofmore » fenthion in human lymphocyte cultures in vitro.« less
Calisher, Charles H; Mills, James N; Root, Jon Jeffrey; Doty, Jeffrey B; Beaty, Barry J
2011-05-01
Sin Nombre virus (SNV) is the principal cause of hantavirus pulmonary syndrome (HPS) in the United States and deer mice (Peromyscus maniculatus) are its principal rodent host, and thus the natural cycle of the virus is related to the occurrence of HPS. Prevalence of rodent infection appears to be associated with fluctuations in deer mouse populations and, indirectly, with timing and amount of precipitation, a complex of biologic events. Given that rodent population abundances fluctuate, often acutely, it is not unreasonable to assume a direct correlation between the numbers of infected rodents and the number of human infections, unless confounding factors are involved. During a 13-year longitudinal study at a site in southwestern Colorado, we accumulated data regarding deer mice and antibody to SNV and therefore had the opportunity to compare dynamics of deer mouse populations, seroprevalence of antibody to SNV in the rodents, and numbers of HPS cases in Durango and in the State of Colorado as a whole. If abundances of deer mouse populations are directly correlated with occurrence of HPS, it is reasonable to assume that low densities of deer mice and low prevalences of antibody to SNV would lead to fewer human cases than would high densities and high prevalences. Our results substantiate such an assumption and suggest that the risk of acquisition of HPS is likely related to both high numbers of infected deer mice and human activities, rather than being strictly related to prevalence of SNV in the host rodent.
Assortative mating for human height: A meta‐analysis
Simons, Mirre J.P.; Grasman, Sara; Pollet, Thomas V.
2016-01-01
Abstract Objectives The study of assortative mating for height has a rich history in human biology. Although the positive correlation between the stature of spouses has often been noted in western populations, recent papers suggest that mating patterns for stature are not universal. The objective of this paper was to review the published evidence to examine the strength of and universality in assortative mating for height. Methods We conducted an extensive literature review and meta‐analysis. We started with published reviews but also searched through secondary databases. Our search led to 154 correlations of height between partners. We classified the populations as western and non‐western based on geography. These correlations were then analyzed via meta‐analytic techniques. Results 148 of the correlations for partner heights were positive and the overall analysis indicates moderate positive assortative mating (r = .23). Although assortative mating was slightly stronger in countries that can be described as western compared to non‐western, this difference was not statistically significant. We found no evidence for a change in assortative mating for height over time. There was substantial residual heterogeneity in effect sizes and this heterogeneity was most pronounced in western countries. Conclusions Positive assortative mating for height exists in human populations, but is modest in magnitude suggesting that height is not a major factor in mate choice. Future research is necessary to understand the underlying causes of the large amount of heterogeneity observed in the degree of assortative mating across human populations, which may stem from a combination of methodological and ecological differences. PMID:27637175
2011-01-01
Insects carry out essential ecological functions, such as pollination, but also cause extensive damage to agricultural crops and transmit human diseases such as malaria and dengue fever. Advances in insect transgenesis are making it increasingly feasible to engineer genes conferring desirable phenotypes, and gene drive systems are required to spread these genes into wild populations. Medea provides one solution, being able to spread into a population from very low initial frequencies through the action of a maternally-expressed toxin linked to a zygotically-expressed antidote. Several other toxin-antidote combinations are imaginable that distort the offspring ratio in favor of a desired transgene, or drive the population towards an all-male crash. We explore two such systems—Semele, which is capable of spreading a desired transgene into an isolated population in a confined manner; and Merea, which is capable of inducing a local population crash when located on the Z chromosome of a Lepidopteron pest. PMID:21876382
Lankau, Richard A; Strauss, Sharon Y
2011-01-01
Environmental management typically seeks to increase or maintain the population sizes of desirable species and to decrease population sizes of undesirable pests, pathogens, or invaders. With changes in population size come long-recognized changes in ecological processes that act in a density-dependent fashion. While the ecological effects of density dependence have been well studied, the evolutionary effects of changes in population size, via changes in ecological interactions with community members, are underappreciated. Here, we provide examples of changing selective pressures on, or evolution in, species as a result of changes in either density of conspecifics or changes in the frequency of heterospecific versus conspecific interactions. We also discuss the management implications of such evolutionary responses in species that have experienced rapid increases or decreases in density caused by human actions. PMID:25567977
Lin, Ching-Heng; Lin, Ting; Chou, Pesus
2017-01-01
It is important that the utilization of emergency departments (EDs) among people living with the human immunodeficiency virus (HIV) be epidemiologically evaluated in order to assess and improve the HIV care continuum. All participants newly-diagnosed with HIV in Taiwan registered in the National Health Insurance Database from 2000 to 2005 were enrolled in this study and followed-up from 2006 to 2011. In total, 3500 participants newly-diagnosed with HIV in 2000–2005 were selected as a fixed-cohort population and followed-up from 2006 to 2011. Overall, 704, 645, 591, 573, 578, and 568 cases made 1322, 1275, 1050, 1061, 1136, and 992 ED visits in 2006, 2007, 2008, 2009, 2010 and 2011, respectively, with an average number of ED visits ranging from 1.75 to 1.98 per person, accounting for 20.1–22.6% of the whole HIV-positive population. Fewer ED visits were due to traumatic reasons, accounting for 19.6–24.4% of all cases. The incidence of traumatic and non-traumatic ED visits among the HIV-positive participants ranged from 7.2–9.3 and 27.0–33.9 per 100 people, respectively. The average direct medical cost of traumatic and non-traumatic ED visits ranged from $89.3–112.0 and $96.6–120.0, respectively. In conclusion, a lower incidence of ED visits for all reasons and fewer ED visits owing to traumatic causes were observed in the population living with HIV in comparison with the general population; however, the direct medical cost of each ED visit owing to both traumatic and non-traumatic causes was greater among those living with HIV than in the general population. PMID:29019947
NASA Astrophysics Data System (ADS)
Swider, Jan Zenon
The human health risk assessment (HRA), initiated by the onset of nuclear industry, has been a well established methodology for assessing the impacts of human created contamination on an individual human being and entire population. The wide spread of applications and tools grown upon this methodology allows one not only to identify the hazards, but also to manage the risks. Recently, there has existed an increased awareness of the need to conduct ecological risk assessments (ERA) in addition to HRAs. The ERAs are, by and large, more complex than typical HRAs and involve not only different species but whole ecological systems. Such complex analyses require a thorough understanding of the processes underway in the ecosystem, including the contaminant transport through the food web, population dynamics as well as intra- and inter-specific relationships. The exposure pathways change radically depending on the consumer tier. Plants produce their nutriment from the sunlight and raw inorganic compounds. Animals and other living forms obtain energy by eating plants, other animals and detritus. Their double role as food consumers and food producers causes a trophic structure of the ecological system, where nutrients and energy are transferred from one trophic level to another. This is a dynamic process of energy flow, mostly in the form of food, varying with time and space. In order to conduct an efficient ERA, a multidisciplinary framework is needed. This framework can be enhanced by analyzing predator-prey interactions during the environmental disturbances caused by a pollutant emission, and by assessing the consequences of such disturbances. It is necessary to develop a way to describe how human industrial activity affects the ecosystems. Existing ecological studies have mostly been focused either on pure ecological interdependencies or on limited perspectives of human activities. In this study, we discuss the issues of air pollution and its ecological impacts from the Ecological Risk Assessment standpoint and examine the impact of air toxics emissions on an ecosystem, with particular emphasis on predator-prey interactions. Such analysis may help to identify the most likely conditions leading to the ecosystem instability and possibility of its recuperation.
Respicio-Kingry, Laurel B; Yockey, Brook M; Acayo, Sarah; Kaggwa, John; Apangu, Titus; Kugeler, Kiersten J; Eisen, Rebecca J; Griffith, Kevin S; Mead, Paul S; Schriefer, Martin E; Petersen, Jeannine M
2016-02-01
Plague is a life-threatening disease caused by the bacterium, Yersinia pestis. Since the 1990s, Africa has accounted for the majority of reported human cases. In Uganda, plague cases occur in the West Nile region, near the border with Democratic Republic of Congo. Despite the ongoing risk of contracting plague in this region, little is known about Y. pestis genotypes causing human disease. During January 2004-December 2012, 1,092 suspect human plague cases were recorded in the West Nile region of Uganda. Sixty-one cases were culture-confirmed. Recovered Y. pestis isolates were analyzed using three typing methods, single nucleotide polymorphisms (SNPs), pulsed field gel electrophoresis (PFGE), and multiple variable number of tandem repeat analysis (MLVA) and subpopulations analyzed in the context of associated geographic, temporal, and clinical data for source patients. All three methods separated the 61 isolates into two distinct 1.ANT lineages, which persisted throughout the 9 year period and were associated with differences in elevation and geographic distribution. We demonstrate that human cases of plague in the West Nile region of Uganda are caused by two distinct 1.ANT genetic subpopulations. Notably, all three typing methods used, SNPs, PFGE, and MLVA, identified the two genetic subpopulations, despite recognizing different mutation types in the Y. pestis genome. The geographic and elevation differences between the two subpopulations is suggestive of their maintenance in highly localized enzootic cycles, potentially with differing vector-host community composition. This improved understanding of Y. pestis subpopulations in the West Nile region will be useful for identifying ecologic and environmental factors associated with elevated plague risk.
NASA Astrophysics Data System (ADS)
Earthquakes and emerging infections may not have a direct cause and effect relationship like tax evasion and jail, but new evidence suggests that there may be a link between the two human health hazards. Various media accounts have cited a massive 1993 earthquake in Maharashtra as a potential catalyst of the recent outbreak of plague in India that has claimed more than 50 lives and alarmed the world. The hypothesis is that the earthquake may have uprooted underground rat populations that carry the fleas infected with the bacterium that causes bubonic plague and can lead to the pneumonic form of the disease that is spread through the air.
How will HPV vaccines affect cervical cancer?
Roden, Richard; Wu, T.-C.
2011-01-01
Cancer of the uterine cervix is the second largest cause of cancer deaths in women, and its toll is greatest in populations that lack screening programmes to detect precursor lesions. Persistent infection with ‘high risk’ genotypes of human papillomavirus (HPV) is necessary, although not sufficient, to cause cervical carcinoma. Therefore, HPV vaccination provides an opportunity to profoundly affect cervical cancer incidence worldwide. A recently licensed HPV subunit vaccine protects women from a high proportion of precursor lesions of cervical carcinoma and most genital warts. Here we examine the ramifications and remaining questions that surround preventive HPV vaccines. PMID:16990853
Skin microbes on frogs prevent morbidity and mortality caused by a lethal skin fungus.
Harris, Reid N; Brucker, Robert M; Walke, Jenifer B; Becker, Matthew H; Schwantes, Christian R; Flaherty, Devon C; Lam, Brianna A; Woodhams, Douglas C; Briggs, Cheryl J; Vredenburg, Vance T; Minbiole, Kevin P C
2009-07-01
Emerging infectious diseases threaten human and wildlife populations. Altered ecological interactions between mutualistic microbes and hosts can result in disease, but an understanding of interactions between host, microbes and disease-causing organisms may lead to management strategies to affect disease outcomes. Many amphibian species in relatively pristine habitats are experiencing dramatic population declines and extinctions due to the skin disease chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis. Using a randomized, replicated experiment, we show that adding an antifungal bacterial species, Janthinobacterium lividum, found on several species of amphibians to the skins of the frog Rana muscosa prevented morbidity and mortality caused by the pathogen. The bacterial species produces the anti-chytrid metabolite violacein, which was found in much higher concentrations on frog skins in the treatments where J. lividum was added. Our results show that cutaneous microbes are a part of amphibians' innate immune system, the microbial community structure on frog skins is a determinant of disease outcome and altering microbial interactions on frog skins can prevent a lethal disease outcome. A bioaugmentation strategy may be an effective management tool to control chytridiomycosis in amphibian survival assurance colonies and in nature.
A red tide of Alexandrium fundyense in the Gulf of Maine
McGillicuddy, D.J.; Brosnahan, M.L.; Couture, D.A.; He, R.; Keafer, B.A.; Manning, J.P.; Martin, J.L.; Pilskaln, C.H.; Townsend, D.W.; Anderson, D.M.
2013-01-01
In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense. PMID:25170191
Persoon, Gerard A.; Leirs, Herwig; Poudel, Shashank; Subedi, Naresh; Pokheral, Chiranjibi Prasad; Bhattarai, Santosh; Thapaliya, Bishnu Prasad; de Iongh, Hans H.
2018-01-01
Wildlife attacks on humans and economic losses often result in reduced support of local communities for wildlife conservation. Information on spatial and temporal patterns of such losses in the highly affected areas contribute in designing and implementing effective mitigation measures. We analyzed the loss of humans, livestock and property caused by wildlife during 1998 to 2016, using victim family’s reports to Chitwan National Park authorities and Buffer Zone User Committees. A total of 4,014 incidents were recorded including attacks on humans, livestock depredation, property damage and crop raiding caused by 12 wildlife species. In total >400,000 US dollar was paid to the victim families as a relief over the whole period. Most of the attacks on humans were caused by rhino, sloth bear, tiger, elephant, wild boar and leopard. A significantly higher number of conflict incidents caused by rhino and elephant were observed during full moon periods. An increase in the wildlife population did not coincide with an equal rise in conflict incidents reported. Underprivileged ethnic communities were attacked by wildlife more frequently than expected. Number of attacks on humans by carnivores and herbivores did not differ significantly. An insignificant decreasing trend of wildlife attacks on humans and livestock was observed with significant variation over the years. Tiger and leopard caused >90% of livestock depredation. Tigers killed both large (cattle and buffalo) and medium sized (goat, sheep, pig) livestock but leopard mostly killed medium sized livestock. Most (87%) of the livestock killing during 2012–2016 occurred within the stall but close (<500m) to the forest edge. Both the percentage of households with livestock and average holding has decreased over the years in buffer zone. Decreased forest dependency as well as conflict mitigation measures (electric and mesh wire fences) have contributed to keep the conflict incidents in control. Strengthening mitigation measures like construction of electric or mesh wire fences and predator-proof livestock corrals along with educating local communities about wildlife behavior and timely management of problem animals (man-eater tiger, rage elephant etc.) will contribute to reduce the conflict. PMID:29672538
Lamichhane, Babu Ram; Persoon, Gerard A; Leirs, Herwig; Poudel, Shashank; Subedi, Naresh; Pokheral, Chiranjibi Prasad; Bhattarai, Santosh; Thapaliya, Bishnu Prasad; de Iongh, Hans H
2018-01-01
Wildlife attacks on humans and economic losses often result in reduced support of local communities for wildlife conservation. Information on spatial and temporal patterns of such losses in the highly affected areas contribute in designing and implementing effective mitigation measures. We analyzed the loss of humans, livestock and property caused by wildlife during 1998 to 2016, using victim family's reports to Chitwan National Park authorities and Buffer Zone User Committees. A total of 4,014 incidents were recorded including attacks on humans, livestock depredation, property damage and crop raiding caused by 12 wildlife species. In total >400,000 US dollar was paid to the victim families as a relief over the whole period. Most of the attacks on humans were caused by rhino, sloth bear, tiger, elephant, wild boar and leopard. A significantly higher number of conflict incidents caused by rhino and elephant were observed during full moon periods. An increase in the wildlife population did not coincide with an equal rise in conflict incidents reported. Underprivileged ethnic communities were attacked by wildlife more frequently than expected. Number of attacks on humans by carnivores and herbivores did not differ significantly. An insignificant decreasing trend of wildlife attacks on humans and livestock was observed with significant variation over the years. Tiger and leopard caused >90% of livestock depredation. Tigers killed both large (cattle and buffalo) and medium sized (goat, sheep, pig) livestock but leopard mostly killed medium sized livestock. Most (87%) of the livestock killing during 2012-2016 occurred within the stall but close (<500m) to the forest edge. Both the percentage of households with livestock and average holding has decreased over the years in buffer zone. Decreased forest dependency as well as conflict mitigation measures (electric and mesh wire fences) have contributed to keep the conflict incidents in control. Strengthening mitigation measures like construction of electric or mesh wire fences and predator-proof livestock corrals along with educating local communities about wildlife behavior and timely management of problem animals (man-eater tiger, rage elephant etc.) will contribute to reduce the conflict.
Alavi, Seyed Mohammad; Alavi, Leila
2016-01-01
Background: Human toxoplasmosis is an important zoonotic infection worldwide which is caused by the intracellular parasite Toxoplasma gondii (T.gondii). The aim of this study was to review briefly the general aspects of toxoplasma infection in in Iranian health system network. Methods: We searched published toxoplasmosis related articles in English databases including Science Direct, Pub Med, Scopus, Google Scholar, Magiran, Iran Medex, Iran Doc and Scientific Information Database (SID) for toxoplasmosis. Results: Out of 1267 articles from the English and Persian databases search, 40 articles were suitable with our research objectives and so were selected for the study. It is estimated that at least a third of the world human population is infected with T.gondii, suggesting it as one of the most common parasitic infections through the world. Maternal infection during pregnancy may affect dangerous outcome for the fetus, or even cause intrauterine death. Reactivation of a previous infection in immunocompromised patient such as drug induced, AIDS and organ transplantation can cause life-threating central nervous system infection. Ocular toxoplasmosis is one of the most important causes of blindness, especially in individuals with a deficient immune system. Conclusion: According to the increasing burden of toxoplasmosis on human health, the findings of this study highlight the appropriate preventive measures, diagnosis, and management of this disease. PMID:27999640
Sabbagh, Audrey; Darlu, Pierre; Crouau-Roy, Brigitte; Poloni, Estella S.
2011-01-01
Arylamine N-acetyltransferase 2 (NAT2) is involved in human physiological responses to a variety of xenobiotic compounds, including common therapeutic drugs and exogenous chemicals present in the diet and the environment. Many questions remain about the evolutionary mechanisms that have led to the high prevalence of slow acetylators in the human species. Evidence from recent surveys of NAT2 gene variation suggests that NAT2 slow-causing variants might have become targets of positive selection as a consequence of the shift in modes of subsistence and lifestyle in human populations in the last 10,000 years. We aimed to test more extensively the hypothesis that slow acetylation prevalence in humans is related to the subsistence strategy adopted by the past populations. To this end, published frequency data on the most relevant genetic variants of NAT2 were collected from 128 population samples (14,679 individuals) representing different subsistence modes and dietary habits, allowing a thorough analysis at both a worldwide and continent scale. A significantly higher prevalence of the slow acetylation phenotype was observed in populations practicing farming (45.4%) and herding (48.2%) as compared to populations mostly relying on hunting and gathering (22.4%) (P = 0.0007). This was closely mirrored by the frequency of the slow 590A variant that was found to occur at a three-fold higher frequency in food producers (25%) as compared to hunter-gatherers (8%). These findings are consistent with the hypothesis that the Neolithic transition to subsistence economies based on agricultural and pastoral resources modified the selective regime affecting the NAT2 acetylation pathway. Furthermore, the vast amount of data collected enabled us to provide a comprehensive and up-to-date description of NAT2 worldwide genetic diversity, thus building up a useful resource of frequency data for further studies interested in epidemiological or anthropological research questions involving NAT2. PMID:21494681
Power-line electrocution of birds (Electrocucion de Aves en Lineas Electricas en Mexico)
Patricia Manzano Fischer
2006-01-01
A result of rapid growth in human population and energy use, is proliferating power lines that electrocute birds, killing eagles and causing power outages. The United States was one of the first countries to recognize the significance of this problem. Suggested Practices for the Protection of Raptors on Power Lines, first published in the 1970s, has now been translated...
Safety and efficacy of a novel live attenuated influenza vaccine against pandemic H1N1 in swine
USDA-ARS?s Scientific Manuscript database
On June 11, 2009 the World Health Organization (WHO) declared that the outbreaks caused by novel swine-origin influenza A (H1N1) virus had reached pandemic proportions. The pandemic H1N1 (H1N1pdm) is the predominant influenza strain in the human population. It has also crossed the species barriers a...