38 research outputs found

    Temporal Anomalies in Immunological Gene Expression in a Time Series of Wild Mice: Signature of an Epidemic?

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    Although the ecological importance of coinfection is increasingly recognized, analyses of microbial pathogen dynamics in wildlife usually focus on an ad hoc subset of the species present due to technological limitations on detection. Here we demonstrate the use of expression profiles for immunological genes (pattern recognition receptors, cytokines and transcription factors) as a means to identify, without preconception, the likelihood of important acute microbial infections in wildlife. Using a wood mouse population in the UK as a model we identified significant temporal clusters of individuals with extreme expression of immunological mediators across multiple loci, typical of an acute microbial infection. These clusters were circumstantially associated with demographic perturbation in the summertime wood mouse population. Animals in one cluster also had significantly higher individual macroparasite burdens than contemporaries with “normal” expression patterns. If the extreme transcriptional profiles observed are induced by an infectious agent then this implicates macroparasites as a possible player in mediating individual susceptibility or resilience to infection. The form of survey described here, combined with next generation nucleic acids sequencing methods for the broad detection of microbial infectious agents in individuals with anomalous immunological transcriptional profiles, could be a powerful tool for revealing unrecognized, ecologically important infectious agents circulating in wildlife populations

    Immunomodulatory parasites and toll-like receptor-mediated tumour necrosis factor alpha responsiveness in wild mammals

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    BACKGROUND: Immunological analyses of wild populations can increase our understanding of how vertebrate immune systems respond to 'natural' levels of exposure to diverse infections. A major recent advance in immunology has been the recognition of the central role of phylogenetically conserved toll-like receptors in triggering innate immunity and the subsequent recruitment of adaptive response programmes. We studied the cross-sectional associations between individual levels of systemic toll-like receptor-mediated tumour necrosis factor alpha responsiveness and macro- and microparasite infections in a natural wood mouse (Apodemus sylvaticus) population. RESULTS: Amongst a diverse group of macroparasites, only levels of the nematode Heligmosomoides polygyrus and the louse Polyplax serrata were correlated (negatively) with innate immune responsiveness (measured by splenocyte tumour necrosis factor alpha responses to a panel of toll-like receptor agonists). Polyplax serrata infection explained a strikingly high proportion of the total variation in innate responses. Contrastingly, faecal oocyst count in microparasitic Eimeria spp. was positively associated with innate immune responsiveness, most significantly for the endosomal receptors TLR7 and TLR9. CONCLUSION: Analogy with relevant laboratory models suggests the underlying causality for the observed patterns may be parasite-driven immunomodulatory effects on the host. A subset of immunomodulatory parasite species could thus have a key role in structuring other infections in natural vertebrate populations by affecting the 'upstream' innate mediators, like toll-like receptors, that are important in initiating immunity. Furthermore, the magnitude of the present result suggests that populations free from immunosuppressive parasites may exist at 'unnaturally' elevated levels of innate immune activation, perhaps leading to an increased risk of immunopathology

    A community based systems diagram of obesity causes

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    INTRODUCTION: Application of system thinking to the development, implementation and evaluation of childhood obesity prevention efforts represents the cutting edge of community-based prevention. We report on an approach to developing a system oriented community perspective on the causes of obesity. METHODS: Group model building sessions were conducted in a rural Australian community to address increasing childhood obesity. Stakeholders (n = 12) built a community model that progressed from connection circles to causal loop diagrams using scripts from the system dynamics literature. Participants began this work in identifying change over time in causes and effects of childhood obesity within their community. The initial causal loop diagram was then reviewed and elaborated by 50 community leaders over a full day session. RESULTS: The process created a causal loop diagram representing community perceptions of determinants and causes of obesity. The causal loop diagram can be broken down into four separate domains; social influences; fast food and junk food; participation in sport; and general physical activity. DISCUSSION: This causal loop diagram can provide the basis for community led planning of a prevention response that engages with multiple levels of existing settings and systems

    An Immunological Marker of Tolerance to Infection in Wild Rodents

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    Hosts are likely to respond to parasitic infections by a combination of resistance (expulsion of pathogens) and tolerance (active mitigation of pathology). Of these strategies, the basis of tolerance in animal hosts is relatively poorly understood, with especially little known about how tolerance is manifested in natural populations. We monitored a natural population of field voles using longitudinal and cross-sectional sampling modes and taking measurements on body condition, infection, immune gene expression, and survival. Using analyses stratified by life history stage, we demonstrate a pattern of tolerance to macroparasites in mature compared to immature males. In comparison to immature males, mature males resisted infection less and instead increased investment in body condition in response to accumulating burdens, but at the expense of reduced reproductive effort. We identified expression of the transcription factor Gata3 (a mediator of Th2 immunity) as an immunological biomarker of this tolerance response. Time series data for individual animals suggested that macroparasite infections gave rise to increased expression of Gata3, which gave rise to improved body condition and enhanced survival as hosts aged. These findings provide a clear and unexpected insight into tolerance responses (and their life history sequelae) in a natural vertebrate population. The demonstration that such responses (potentially promoting parasite transmission) can move from resistance to tolerance through the course of an individual’s lifetime emphasises the need to incorporate them into our understanding of the dynamics and risk of infection in the natural environment. Moreover, the identification of Gata3 as a marker of tolerance to macroparasites raises important new questions regarding the role of Th2 immunity and the mechanistic nature of the tolerance response itself. A more manipulative, experimental approach is likely to be valuable in elaborating this further

    Positive- and negative peer modelling effects on young children's consumption of novel blue foods.

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    ObjectiveThe effects of positive- and negative peer modelling on children's consumption of a novel blue food, presented in each of four snack meals during an "activity" day, were evaluated. It was predicted that: (i) novel food consumption would increase after positive modelling, but decrease after negative modelling; (ii) modelling effects would generalise to a second novel blue food when participants were alone when they ate their snack; (iii) that positive modelling would reverse the effects of negative modelling.DesignA mixed design was employed with random assignment to either Groups A, B, or C (equal numbers of males and females per group). Within groups, each participant received the novel food on four snack occasions. Group A received positive modelling of blue food consumption on the first and third occasions, but were alone when they received the foods on the second and fourth occasions; Group B had negative modelling on the first occasion, positive modelling on the third, and ate alone on the second and fourth; Group C ate alone on all four occasions. To measure generalisation, an additional blue food was presented in all second and fourth "alone" occasions.ParticipantsThirty-five 5-7-year olds took part in Study 1, and 44 3-4-year olds in Study 2.ResultsAll main predictions were confirmed except that positive peer modelling did not reverse the effects of negative modelling in the 3-4-year olds.ConclusionNegative peer modelling inhibits novel food consumption, and its effects are particularly difficult to reverse in younger children

    A lesson from the wild: The natural state of eosinophils is Ly6G hi

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    From Wiley via Jisc Publications RouterHistory: received 2021-07-12, rev-recd 2021-08-29, accepted 2021-09-02, pub-electronic 2021-09-15Article version: VoRPublication status: PublishedFunder: Biotechnology and Biological Sciences Research Council; Grant(s): BB/P018157/1Abstract: With a long history of promoting pathological inflammation, eosinophils are now emerging as important regulatory cells. Yet, findings from controlled laboratory experiments so far lack translation to animals, including humans, in their natural environment. In order to appreciate the breadth of eosinophil phenotype under non‐laboratory, uncontrolled conditions, we exploit a free‐living population of the model organism Mus musculus domesticus. Eosinophils were present at significantly higher proportions in the spleen and bone marrow of wild mice compared with laboratory mice. Strikingly, the majority of eosinophils of wild mice exhibited a unique Ly6Ghi phenotype seldom described in laboratory literature. Ly6G expression correlated with activation status in spleen and bone marrow, but not peritoneal exudate cells, and is therefore likely not an activation marker per se. Intermediate Ly6G expression was transiently induced in a small proportion of eosinophils from C57BL/6 laboratory mice during acute infection with the whipworm Trichuris muris, but not during low‐dose chronic infection, which better represents parasite exposure in the wild. We conclude that the natural state of the eosinophil is not adequately reflected in the standard laboratory mouse, which compromises our attempts to dissect their functional relevance. Our findings emphasize the importance of studying the immune system in its natural context – alongside more mechanistic laboratory experiments – in order to capture the entirety of immune phenotypes and functions

    Immune state is associated with natural dietary variation in wild mice Mus musculus domesticus

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    1. The ability, propensity and need to mount an immune response vary both among individuals and within a single individual over time.2. A wide array of parameters have been found to influence immune state in carefully controlled experiments, but we understand much less about which of these parameters are important in determining immune state in wild populations.3. Diet can influence immune responses, for example when nutrient availability is limited. We therefore predict that natural dietary variation will play a role in modulating immune state, but this has never been tested.4. We measured carbon and nitrogen stable isotope ratios in an island population of house mice Mus musculus domesticus as an indication of dietary variation, and the expression of a range of immune?related genes to represent immune state.5. After accounting for potential confounding influences such as age, sex and helminth load, we found a significant association between carbon isotope ratio and levels of immune activity in the mesenteric lymph nodes, particularly in relation to the inflammatory response.6. This association demonstrates the important interplay between diet and an animal's response to immune challenges, and therefore potentially its susceptibility to disease

    Physiological, but not fitness, effects of two interacting haemoparasitic infections in a wild rodent

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    In contrast to the conditions in most laboratory studies, wild animals are routinely challenged by multiple infections at once, and these infections can interact in complex ways. This means that the impact of a parasite on its host’s physiology and fitness cannot be fully assessed in isolation, and requires consideration of the interactions with other co-infections. Here we examine the impact of two common blood parasites in the field vole (Microtus agrestis): Babesia microti and Bartonella spp., both of which have zoonotic potential. We collected longitudinal and cross-sectional data from four populations of individually tagged wild field voles. This included data on biometrics, life history, ectoparasite counts, presence/absence of microparasites, immune markers and, for a subset of voles, more detailed physiological and immunological measurements. This allowed us to monitor infections over time and to estimate components of survival and fecundity. We confirm, as reported previously, that B. microti has a preventative effect on infection with Bartonella spp., but that the reverse is not true. We observed gross splenomegaly following B. microti infection, and an increase in IL-10 production together with some weight loss following Bartonella spp. infection. However, these animals appeared otherwise healthy and we detected no impact of infection on survival or fecundity due to the two haemoparasite taxa. This is particularly remarkable in the case of B. microti which induces apparently drastic long-term changes to spleen sizes, but without major adverse effects. Our work sheds light on the ecologies of these important zoonotic agents, and more generally on the influence that interactions among multiple parasites have on their hosts in the wild

    Research data management as a “wicked problem”

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    Purpose – The purpose of this paper is to explore the usefulness of the concept to thinking about Research Data Management (RDM). The concept of “wicked problems” seeks to differentiate very complex, intractable challenges from tamer issues where approaches to problem solving are well-understood. Design/methodology/approach – The paper is based on and co-authored by a collaboration of practitioners from libraries, information technology and research administration, with facilitators from the Sheffield Information School. Participants worked together in two-day-long workshops to understand the wicked problem concept and advice on leadership in wicked problem contexts. Findings – Participants concurred that RDM had many features of a wicked problem and most of Grint’s advice on leadership for wicked problems also resonated. Some elements of the issue were simple; participants were optimistic about improving the situation over time. Participants were resistant to the more negative or fatalistic connotations of the phrase “wicked problem”. Viewing RDM as a wicked problem is an interesting way of looking at it as a challenge for support professionals. Practical implications – The notion of a wicked problem is a generative concept that can be usefully added to professional vocabulary. Originality/value – The paper captures an in-depth response from practitioners to the notion of wicked problems as a lens for examining RDM

    Cross-cutting principles for planetary health education

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    Since the 2015 launch of the Rockefeller Foundation Lancet Commission on planetary health,1 an enormous groundswell of interest in planetary health education has emerged across many disciplines, institutions, and geographical regions. Advancing these global efforts in planetary health education will equip the next generation of scholars to address crucial questions in this emerging field and support the development of a community of practice. To provide a foundation for the growing interest and efforts in this field, the Planetary Health Alliance has facilitated the first attempt to create a set of principles for planetary health education that intersect education at all levels, across all scales, and in all regions of the world—ie, a set of cross-cutting principles
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