102 research outputs found
Seabirds and the circulation of Lyme borreliosis bacteria in the North Pacific
Seabirds act as natural reservoirs to Lyme borreliosis spirochetes and may play a significant role in the global circulation of these pathogens. While Borrelia burgdorferi sensu lato (Bbsl) has been shown to occur in ticks collected from certain locations in the North Pacific, little is known about interspecific differences in exposure within the seabird communities of this region. We examined the prevalence of anti-Bbsl antibodies in 805 individuals of nine seabird species breeding across the North Pacific. Seroprevalence varied strongly among species and locations. Murres (Uria spp.) showed the highest antibody prevalence and may play a major role in facilitating Bbsl circulation at a worldwide scale. Other species showed little or no signs of exposure, despite being present in multispecific colonies with seropositive birds. Complex dynamics may be operating in this wide scale, natural hostparasite system, possibly mediated by the host immune system and host specialization of the tick vector
Turn costs change the value of animal search paths
This paper is one of the first to point out that turning has an energetic cost for animal and human movement. The paper presents empirical data obtained from tests on humans following paths including turns of various angles
The Puzzle of Altruism: Why do ‘Selfish Genes’ Behave so Unselfishly?
There are sound evolutionary and philosophical reasons for believing that human beings have a powerful innate disposition towards pure altruism—an altruism that is not a form of disguised selfishness, a survival strategy, or limited to those with whom we are closely genetically related. An overview of archaeological and anthropologic evidence suggests that the so-called 'environment of evolutionary adaptedness' was very different to the brutal, competitive struggle typically depicted by evolutionary psychologists. It is false to assume that competitiveness and selfishness are inevitable and fundamental human traits. An alternative view that altruism and co-operation are fundamental traits could more justifiably be drawn from archaeological and anthropological evidence. The philosophy of ‘panspiritism’ suggests that pure altruism is the result of the human capacity for empathy, which itself is the result of our fundamental interconnectedness
Foraging success under uncertainty: search tradeoffs and optimal space use
15 páginas, 8 figuras.Understanding the structural complexity and the main drivers of animal search behaviour is
pivotal to foraging ecology. Yet, the role of uncertainty as a generative mechanism of movement
patterns is poorly understood. Novel insights from search theory suggest that organisms should
collect and assess new information from the environment by producing complex exploratory
strategies. Based on an extension of the first passage time theory, and using simple equations and
simulations, we unveil the elementary heuristics behind search behaviour. In particular, we show
that normal diffusion is not enough for determining optimal exploratory behaviour but anomalous
diffusion is required. Searching organisms go through two critical sequential phases (approach and
detection) and experience fundamental search tradeoffs that may limit their encounter rates. Using
experimental data, we show that biological search includes elements not fully considered in
contemporary physical search theory. In particular, the need to consider search movement as a
non-stationary process that brings the organism from one informational state to another. For
example, the transition from remaining in an area to departing from it may occur through an
exploratory state where cognitive search is challenged. Therefore, a more comprehensive view of
foraging ecology requires including current perspectives about movement under uncertainty.FB, VM, and DC acknowledge the Spanish Ministry of
Science and Innovation (BFU 2010-22337, FIS 2012-32334)
and the Catalan Government (SGR2014-923). FB and WSR
acknowledge the Human Frontier Science Program
(RGY0084/2011)Peer reviewe
Social sciences research in neglected tropical diseases 2: A bibliographic analysis
The official published version of the article can be found at the link below.Background
There are strong arguments for social science and interdisciplinary research in the neglected tropical diseases. These diseases represent a rich and dynamic interplay between vector, host, and pathogen which occurs within social, physical and biological contexts. The overwhelming sense, however, is that neglected tropical diseases research is a biomedical endeavour largely excluding the social sciences. The purpose of this review is to provide a baseline for discussing the quantum and nature of the science that is being conducted, and the extent to which the social sciences are a part of that.
Methods
A bibliographic analysis was conducted of neglected tropical diseases related research papers published over the past 10 years in biomedical and social sciences. The analysis had textual and bibliometric facets, and focussed on chikungunya, dengue, visceral leishmaniasis, and onchocerciasis.
Results
There is substantial variation in the number of publications associated with each disease. The proportion of the research that is social science based appears remarkably consistent (<4%). A textual analysis, however, reveals a degree of misclassification by the abstracting service where a surprising proportion of the "social sciences" research was pure clinical research. Much of the social sciences research also tends to be "hand maiden" research focused on the implementation of biomedical solutions.
Conclusion
There is little evidence that scientists pay any attention to the complex social, cultural, biological, and environmental dynamic involved in human pathogenesis. There is little investigator driven social science and a poor presence of interdisciplinary science. The research needs more sophisticated funders and priority setters who are not beguiled by uncritical biomedical promises
Many Neglected Tropical Diseases May Have Originated in the Paleolithic or Before: New Insights from Genetics
The standard view of modern human infectious diseases is that many of them arose during the Neolithic when animals were first domesticated, or afterwards. Here we review recent genetic and molecular clock estimates that point to a much older Paleolithic origin (2.5 million years ago to 10,000 years ago) of some of these diseases. During part of this ancient period our early human ancestors were still isolated in Africa. We also discuss the need for investigations of the origin of these diseases in African primates and other animals that have been the original source of many neglected tropical diseases
Virological and serological surveillance for type A influenza in the black-legged kittiwake (Rissa tridactyla)
<p>Abstract</p> <p>Background</p> <p>The epidemiology of avian influenza viruses (AIVs) in gulls is only partially known. The role of the world's most numerous gull species, the black-legged kittiwake (<it>Rissa tridactyla</it>), as a potential AIV reservoir species has been unclear. The prevalence of AIV and humoral response against AIV were therefore studied in a colony of apparently healthy black-legged kittiwakes breeding in a nesting cliff in the South West Barents Region of Norway (70°22' N, 31°10' E), in 2008 and 2009.</p> <p>Results</p> <p>AIVs were detected from the oropharynx and cloaca in low amounts, with prevalences of 15% and 5%, in 2008 and 2009, respectively. Direct, partial sequencing of the hemagglutinin (HA) gene revealed that the H4 subtype was present. In 2009, antibodies to influenza A virus were detected in sera from 57 of 80 adult birds. In contrast, none of the three-week-old chicks (n = 18) tested seropositive. Hemagglutination inhibition (HI) assays demonstrated that the adult kittiwakes primarily had antibodies specific to the gull-associated H13 and H16 subtypes, with antibodies to H16 being most common.</p> <p>Conclusions</p> <p>These results support that the highly pelagic black-legged kittiwake is a reservoir of AIV. The serological findings suggest that H16 might be the main AIV subtype in the black-legged kittiwake. Further studies are needed to understand the ecology of AIV in the black-legged kittiwake and in gulls in general.</p
Insights into Cross-Kingdom Plant Pathogenic Bacteria
Plant and human pathogens have evolved disease factors to successfully exploit their respective hosts. Phytopathogens utilize specific determinants that help to breach reinforced cell walls and manipulate plant physiology to facilitate the disease process, while human pathogens use determinants for exploiting mammalian physiology and overcoming highly developed adaptive immune responses. Emerging research, however, has highlighted the ability of seemingly dedicated human pathogens to cause plant disease, and specialized plant pathogens to cause human disease. Such microbes represent interesting systems for studying the evolution of cross-kingdom pathogenicity, and the benefits and tradeoffs of exploiting multiple hosts with drastically different morphologies and physiologies. This review will explore cross-kingdom pathogenicity, where plants and humans are common hosts. We illustrate that while cross-kingdom pathogenicity appears to be maintained, the directionality of host association (plant to human, or human to plant) is difficult to determine. Cross-kingdom human pathogens, and their potential plant reservoirs, have important implications for the emergence of infectious diseases
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