1,393 research outputs found

    Ecological knowledge, leadership, and the evolution of menopause in killer whales

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    This is the final version of the article. Available from Elsevier via the DOI in this record.There is another record in ORE for this publication: http://hdl.handle.net/10871/16488Classic life-history theory predicts that menopause should not occur because there should be no selection for survival after the cessation of reproduction [1]. Yet, human females routinely live 30 years after they have stopped reproducing [2]. Only two other species-killer whales (Orcinus orca) and short-finned pilot whales (Globicephala macrorhynchus) [3, 4]-have comparable postreproductive lifespans. In theory, menopause can evolve via inclusive fitness benefits [5, 6], but the mechanisms by which postreproductive females help their kin remain enigmatic. One hypothesis is that postreproductive females act as repositories of ecological knowledge and thereby buffer kin against environmental hardships [7, 8]. We provide the first test of this hypothesis using a unique long-term dataset on wild resident killer whales. We show three key results. First, postreproductively aged females lead groups during collective movement in salmon foraging grounds. Second, leadership by postreproductively aged females is especially prominent in difficult years when salmon abundance is low. This finding is critical because salmon abundance drives both mortality and reproductive success in resident killer whales [9, 10]. Third, females are more likely to lead their sons than they are to lead their daughters, supporting predictions of recent models [5] of the evolution of menopause based on kinship dynamics. Our results show that postreproductive females may boost the fitness of kin through the transfer of ecological knowledge. The value gained from the wisdom of elders can help explain why female resident killer whales and humans continue to live long after they have stopped reproducing.This research was funded by a Natural Environment Research Council grant (NE/K01286X/1) to D.P.C., D.W.F., and M.A.C

    'Pest' and resource: A legal history of Australia's kangaroos

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    This paper presents an investigation into the legal history of Australias kangaroos. It aims to provide a detailed analysis of how the law and policy governing the killing of kangaroos has evolved over time in response to changing public perceptions. This history begins with the pre-European period and traces the impact of European colonisation, early growth of the commercial kangaroo industry, and the increased role of science and regulation upon kangaroos. The paper critiques the historical designation of kangaroos as `pests that need to be `managed and argues that such an approach is inconsistent with current scientific understanding. As this `pest status has fallen in importance there has been a shift in regulatory goals from damage mitigation to resource utilisation, although government planning and policy continue to cite damage mitigation alongside objectives to maintain viable populations and a sustainable and commercially viable industry. While the kangaroo industrys current focus is upon the `sustainable use of wildlife, the history of attitudes towards kangaroos as `pests is so deeply and widely entrenched that it is impossible for the industry to meet welfare standards. The article concludes that the commercial kangaroo industry does not have any clearly defined policy benefit and should be reassessed to take greater account of the impact it has on ecosystems and kangaroo welfar

    A systematic review of the sources of dietary salt around the world

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    Excess salt intake contributes to hypertension and increased cardiovascular disease risk. Efforts to implement effective salt-reduction strategies require accurate data on the sources of salt consumption. We therefore performed a systematic review to identify the sources of dietary salt around the world. We systematically searched peer-reviewed and gray literature databases for studies that quantified discretionary (salt added during cooking or at the table) and nondiscretionary sources of salt and those that provided information about the food groups contributing to dietary salt intake. Exploratory linear regression analysis was also conducted to assess whether the proportion of discretionary salt intake is related to the gross domestic product (GDP) per capita of a country. We identified 80 studies conducted in 34 countries between 1975 and 2018. The majority (n = 44, 55%) collected data on dietary salt sources within the past 10 y and were deemed to have a low or moderate risk of bias (n = 75, 94%). Thirty-two (40%) studies were judged to be nationally representative. Populations in Brazil, China, Costa Rica, Guatemala, India, Japan, Mozambique, and Romania received more than half of their daily salt intake from discretionary sources. A significant inverse correlation between discretionary salt intake and a country's per capita GDP was observed (P < 0.0001), such that for every $10,000 increase in per capita GDP, the amount of salt obtained from discretionary sources was lower by 8.7% (95% CI: 5.1%, 12%). Bread products, cereal and grains, meat products, and dairy products were the major contributors to dietary salt intake in most populations. There is marked variation in discretionary salt use around the world that is highly correlated with the level of economic development. Our findings have important implications for the type of salt-reduction strategy likely to be effective in a country

    Balancing the dilution and oddity effects: Decisions depend on body size

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    Background Grouping behaviour, common across the animal kingdom, is known to reduce an individual's risk of predation; particularly through dilution of individual risk and predator confusion (predator inability to single out an individual for attack). Theory predicts greater risk of predation to individuals more conspicuous to predators by difference in appearance from the group (the ‘oddity’ effect). Thus, animals should choose group mates close in appearance to themselves (eg. similar size), whilst also choosing a large group. Methodology and Principal Findings We used the Trinidadian guppy (Poecilia reticulata), a well known model species of group-living freshwater fish, in a series of binary choice trials investigating the outcome of conflict between preferences for large and phenotypically matched groups along a predation risk gradient. We found body-size dependent differences in the resultant social decisions. Large fish preferred shoaling with size-matched individuals, while small fish demonstrated no preference. There was a trend towards reduced preferences for the matched shoal under increased predation risk. Small fish were more active than large fish, moving between shoals more frequently. Activity levels increased as predation risk decreased. We found no effect of unmatched shoal size on preferences or activity. Conclusions and Significance Our results suggest that predation risk and individual body size act together to influence shoaling decisions. Oddity was more important for large than small fish, reducing in importance at higher predation risks. Dilution was potentially of limited importance at these shoal sizes. Activity levels may relate to how much sampling of each shoal was needed by the test fish during decision making. Predation pressure may select for better decision makers to survive to larger size, or that older, larger fish have learned to make shoaling decisions more efficiently, and this, combined with their size relative to shoal-mates, and attractiveness as prey items influences shoaling decisions

    Interhemispheric temporal lobe connectivity predicts language impairment in adolescents born preterm.

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    Although language difficulties are common in children born prematurely, robust neuroanatomical correlates of these impairments remain to be established. This study investigated whether the greater prevalence of language problems in preterm (versus term-born) children might reflect injury to major intra- or interhemispheric white matter pathways connecting frontal and temporal language regions. To investigate this, we performed a comprehensive assessment of language and academic abilities in a group of adolescents born prematurely, some of whom had evidence of brain injury at birth (n = 50, mean age: 16 years, mean gestational age: 27 weeks) and compared them to a term-born control group (n = 30). Detailed structural magnetic resonance imaging and diffusion-tractography analyses of intrahemispheric and interhemispheric white matter bundles were performed. Analysis of intrahemispheric pathways included the arcuate fasciculus (dorsal language pathway) and uncinate fasciculus/extreme capsule (ventral language pathway). Analysis of interhemispheric pathways (in particular, connections between the temporal lobes) included the two major commissural bundles: the corpus callosum and anterior commissure. We found language impairment in 38% of adolescents born preterm. Language impairment was not related to abnormalities of the arcuate fasciculus (or its subsegments), but was associated with bilateral volume reductions in the ventral language pathway. However, the most significant volume reduction was detected in the posterior corpus callosum (splenium), which contains interhemispheric connections between the occipital, parietal and temporal lobes. Diffusion tractography showed that of the three groups of interhemispheric fibres within the splenium, only those connecting the temporal lobes were reduced. Crucially, we found that language impairment was only detectable if the anterior commissure (a second temporal lobe commissural pathway) was also small. Regression analyses showed that a combination of anatomical measures of temporal interhemispheric connectivity (through the splenium of the corpus callosum and anterior commissure) explained 57% of the variance in language abilities. This supports recent theories emphasizing the importance of interhemispheric connections for language, particularly in the developing brain

    Fear of predation drives stable and differentiated social relationships in guppies

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    This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this record.Social relationships can have important consequences for fitness in animals. Whilst numerous studies have shown that individuals often join larger groups in response to perceived predation risk (i.e. fear of predation), the importance of predation risk in driving the formation and stability of social relationships within groups has been relatively ignored. We experimentally tested how predation threat influenced fine-scale social network structure using Trinidadian guppies (Poecilia reticulata). When perceived predation risk was high, individuals developed stable and more differentiated social ties compared to when perceived risk was low. Intriguingly, social differentiation coincided with shoals being somewhat smaller under high-perceived risk, suggesting a possible conflict between forming stable social relationships and larger social groups. Individuals most at risk of predation (large and bold individuals) showed the most exaggerated responses in several social measures. Taken together, we provide the first experimental evidence that proximate risk of predation can increase the intensity of social relationships and fine-scale social structure in animal populations.DPC acknowledges funding from the National Environmental Research Council (NE/E001181/1) and Leverhulme Trust (RPG-175) and SKD and DPC acknowledge funding from The Danish Council for Independent Research (DFF – 1323-00105)

    Real-Life Anti-Tumour Necrosis Factor Experience in > 500 Paediatric United Kingdom Inflammatory Bowel Disease Patients.

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    OBJECTIVES: To measure the effectiveness, safety and use of anti-Tumour necrosis Factor (TNF) therapy in paediatric inflammatory bowel disease (PIBD) in the United Kingdom (UK). METHODS: Prospective UK audit of patients newly starting anti-TNF therapy. Disease severity was assessed using Physician Global Assessment (PGA) +/or the Paediatric Crohn's Disease Activity Index (PCDAI). RESULTS: 37 centres participated (23 of 25 specialist PIBD sites). 524 patients were included; 429 Crohn's disease (CD), 76 ulcerative colitis (UC), 19 IBD unclassified (IBDU). 87% (488/562) anti-TNF was infliximab; commonest indication was active luminal CD 77% (330/429) or chronic refractory UC/IBDU 56% (53/95); 79% (445/562) had concomitant co-immunosuppression. In CD (267/429 male), median time from diagnosis to treatment was 1.42 years (IQR 0.63-2.97). Disease (at initiation) was moderate or severe in 91% (156/171) by PGA compared to 41% (88/217) by PCDAI; Kappa (Κ) 0.28 = only 'fair agreement' (p < 0.001).Where documented, 77% (53/69) of CD patients responded to induction; and 65% (46/71) entered remission. 2287 infusions and 301.96 years of patient follow-up (n = 385) are represented; adverse events affected 3% (49/1587) infliximab and 2% (2/98) adalimumab infusions (no deaths or malignancies). Perianal abscess drainage was less common after anti-TNF initiation (CD): 26% (27/102) before, 7% (3/42) after (p = 0.01); however pre and post anti-TNF data collection was not over equal time periods. CONCLUSION: Anti-TNFs are effective treatments, usually given with thiopurine co-immunosuppression. This study highlights deficiencies in formal documentation of effect and disparity between disease severity scoring tools which need to be addressed to improve ongoing patient care

    Linking Proteins to Signaling Pathways for Experiment Design and Evaluation

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    Biomedical experimental work often focuses on altering the functions of selected proteins. These changes can hit signaling pathways, and can therefore unexpectedly and non-specifically affect cellular processes. We propose PathwayLinker, an online tool that can provide a first estimate of the possible signaling effects of such changes, e.g., drug or microRNA treatments. PathwayLinker minimizes the users' efforts by integrating protein-protein interaction and signaling pathway data from several sources with statistical significance tests and clear visualization. We demonstrate through three case studies that the developed tool can point out unexpected signaling bias in normal laboratory experiments and identify likely novel signaling proteins among the interactors of known drug targets. In our first case study we show that knockdown of the Caenorhabditis elegans gene cdc-25.1 (meant to avoid progeny) may globally affect the signaling system and unexpectedly bias experiments. In the second case study we evaluate the loss-of-function phenotypes of a less known C. elegans gene to predict its function. In the third case study we analyze GJA1, an anti-cancer drug target protein in human, and predict for this protein novel signaling pathway memberships, which may be sources of side effects. Compared to similar services, a major advantage of PathwayLinker is that it drastically reduces the necessary amount of manual literature searches and can be used without a computational background. PathwayLinker is available at http://PathwayLinker.org. Detailed documentation and source code are available at the website

    Clinimetric properties of the Turkish translation of a modified neck disability index

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    <p>Abstract</p> <p>Background</p> <p>Neck pain is a common problem that can greatly affect a person's activities of daily living. Functional status questionnaires are important in assessing this effect, and are used to follow up neck pain management programs. The Neck Disability Index (NDI) is the first-created scale for neck pain-related disability and is widely translated and in common used in many countries. Our aim is investigate to clinometric properties of a Turkish version of modified NDI and to give a choice in daily practise of versions to be used.</p> <p>Methods</p> <p>The modified NDI was applied to 30 patients for reliability. 185 patients participated in the validity study. All patients were recruited from the outpatient clinic of our department. The scale was translated by the forward and backward translation procedure according to the COSMIN criteria. The test was repeated at 48 hours interval for reliability study. SPSS-10.0, software was used for statistical analyses. The Intraclass correlation coefficient was used for the test- retest reliability of the modified NDI. Cronbach α was used for internal consistency. Factor analysis was used for construct validity. The validity of the modified NDI with respect to the SF-36, HAD, VAS pain, VAS disability was assessed using Spearman correlations.</p> <p>Results</p> <p>The Intraclass correlation coefficient between first and second (within 48 hours) evaluation of test (rs) was 0.92. Questions 1,4,6,8,10 were shown to have excellent reliability. (rs > 0.9). Question 10 was the most frequently challenged question because "recreational and social activities" do not have not the same meanings in Turkey than in western countries. This required that detailed explanations be provided by the investigators. Cronbach's alpha for the total index was 0.88. A single factor accounting for 80.2% of the variance was obtained. Validity studies demonstrated good and moderate correlations (rs) among NDI, HAD, VAS, physical function subtitle of SF 36 (0.62, 0.76, 0.68).</p> <p>Conclusions</p> <p>The modified NDI-Turkish version is a reliable and valid test and is suitable for daily practise.</p
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