1,231 research outputs found

    Natural History of Coral-Algae Competition across a Gradient of Human Activity in the Line Islands

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    Competition between corals and benthic algae is prevalent on coral reefs worldwide and has the potential to influence the structure of the reef benthos. Human activities may influence the outcome of these interactions by favoring algae to become the superior competitor, and this type of change in competitive dynamics is a potential mechanism driving coral-algal phase shifts. Here we surveyed the types and outcomes of coral-algal interactions varied across reefs on the different islands. On reefs surrounding inhabited islands, however, turf algae were generally the superior competitors. When corals were broken down by size class, we found that the smallest and the largest coral colonies were the best competitors against algae; the former successfully fought off algae while being completely surrounded, and the latter generally avoided algal overgrowth by growing up above the benthos. Our data suggest that human disruption of the reef ecosystem may lead to a building pattern of competitive disadvantage for corals against encroaching algae, potentially initiating a transition towards algal dominance

    Animal Counting Toolkit : a practical guide to small-boat surveys for estimating abundance of coastal marine mammals

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    The authors thank Synchronicity Earth, Marisla Foundation, and the US Marine Mammal Commission for seed funding for this program.Small cetaceans (dolphins and porpoises) face serious anthropogenic threats in coastal habitats. These include bycatch in fisheries; exposure to noise, plastic and chemical pollution; disturbance from boaters; and climate change. Generating reliable abundance estimates is essential to assess sustainability of bycatch in fishing gear or any other form of anthropogenic removals and to design conservation and recovery plans for endangered species. Cetacean abundance estimates are lacking from many coastal waters of many developing countries. Lack of funding and training opportunities makes it difficult to fill in data gaps. Even if international funding were found for surveys in developing countries, building local capacity would be necessary to sustain efforts over time to detect trends and monitor biodiversity loss. Large-scale, shipboard surveys can cost tens of thousands of US dollars each day. We focus on methods to generate preliminary abundance estimates from low-cost, small-boat surveys that embrace a ā€˜training-while-doingā€™ approach to fill in data gaps while simultaneously building regional capacity for data collection. Our toolkit offers practical guidance on simple design and field data collection protocols that work with small boats and small budgets, but expect analysis to involve collaboration with a quantitative ecologist or statistician. Our audience includes independent scientists, government conservation agencies, NGOs and indigenous coastal communities, with a primary focus on fisheries bycatch. We apply our Animal Counting Toolkit to a small-boat survey in Canadaā€™s Pacific coastal waters to illustrate the key steps in collecting line transect survey data used to estimate and monitor marine mammal abundance.Publisher PDFPeer reviewe

    Genetic and Dietary Factors Influencing the Progression of Nuclear Cataract.

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    PURPOSE: To determine the heritability of nuclear cataract progression and to explore prospectively the effect of dietary micronutrients on the progression of nuclear cataract. DESIGN: Prospective cohort study. PARTICIPANTS: Cross-sectional nuclear cataract and dietary measurements were available for 2054 white female twins from the TwinsUK cohort. Follow-up cataract measurements were available for 324 of the twins (151 monozygotic and 173 dizygotic twins). METHODS: Nuclear cataract was measured using a quantitative measure of nuclear density obtained from digital Scheimpflug images. Dietary data were available from EPIC food frequency questionnaires. Heritability was modeled using maximum likelihood structural equation twin modeling. Association between nuclear cataract change and micronutrients was investigated using linear and multinomial regression analysis. The mean interval between baseline and follow-up examination was 9.4 years. MAIN OUTCOME MEASURES: Nuclear cataract progression. RESULTS: The best-fitting model estimated that the heritability of nuclear cataract progression was 35% (95% confidence interval [CI], 13-54), and individual environmental factors explained the remaining 65% (95% CI, 46-87) of variance. Dietary vitamin C was protective against both nuclear cataract at baseline and nuclear cataract progression (Ī²Ā =Ā -0.0002, PĀ = 0.01 and Ī²Ā =Ā -0.001, PĀ = 0.03, respectively), whereas manganese and intake of micronutrient supplements were protective against nuclear cataract at baseline only (Ī²Ā =Ā -0.009, PĀ = 0.03 and Ī²Ā =Ā -0.03, PĀ = 0.01, respectively). CONCLUSIONS: Genetic factors explained 35% of the variation in progression of nuclear cataract over a 10-year period. Environmental factors accounted for the remaining variance, and in particular, dietary vitamin C protected against cataract progression assessed approximately 10 years after baseline

    Satellite-based emergency mapping using optical imagery: experience and reflections from the 2015 Nepal earthquakes

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    Landslides triggered by large earthquakes in mountainous regions contribute significantly to overall earthquake losses and pose a major secondary hazard that can persist for months or years. While scientific investigations of coseismic landsliding are increasingly common, there is no protocol for rapid (hours-to-days) humanitarian-facing landslide assessment and no published recognition of what is possible and what is useful to compile immediately after the event. Drawing on the 2015 Mw 7.8 Gorkha earthquake in Nepal, we consider how quickly a landslide assessment based upon manual satellite-based emergency mapping (SEM) can be realistically achieved and review the decisions taken by analysts to ascertain the timeliness and type of useful information that can be generated. We find that, at present, many forms of landslide assessment are too slow to generate relative to the speed of a humanitarian response, despite increasingly rapid access to high-quality imagery. Importantly, the value of information on landslides evolves rapidly as a disaster response develops, so identifying the purpose, timescales, and end users of a post-earthquake landslide assessment is essential to inform the approach taken. It is clear that discussions are needed on the form and timing of landslide assessments, and how best to present and share this information, before rather than after an earthquake strikes. In this paper, we share the lessons learned from the Gorkha earthquake, with the aim of informing the approach taken by scientists to understand the evolving landslide hazard in future events and the expectations of the humanitarian community involved in disaster response. Please read the corrigendum first before accessing the articl

    The antimicrobial peptide cathelicidin drives development of experimental autoimmune encephalomyelitis in mice by affecting Th17 differentiation

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    Multiple sclerosis (MS) is a highly prevalent demyelinating autoimmune condition; the mechanisms regulating its severity and progression are unclear. The IL-17-producing Th17 subset of T cells has been widely implicated in MS and in the mouse model, experimental autoimmune encephalomyelitis (EAE). However, the differentiation and regulation of Th17 cells during EAE remain incompletely understood. Although evidence is mounting that the antimicrobial peptide cathelicidin profoundly affects early T cell differentiation, no studies have looked at its role in longer-term T cell responses. Now, we report that cathelicidin drives severe EAE disease. It is released from neutrophils, microglia, and endothelial cells throughout disease; its interaction with T cells potentiates Th17 differentiation in lymph nodes and Th17 to exTh17 plasticity and IFN-Ī³ production in the spinal cord. As a consequence, mice lacking cathelicidin are protected from severe EAE. In addition, we show that cathelicidin is produced by the same cell types in the active brain lesions in human MS disease. We propose that cathelicidin exposure results in highly activated, cytokine-producing T cells, which drive autoimmunity; this is a mechanism through which neutrophils amplify inflammation in the central nervous system

    Increased risk of HPV-associated genital cancers in men and women as a consequence of pre-invasive disease

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    To assess the excess risk of HPVā€associated cancer (HPVaC) in two atā€risk groups ā€“ women with a previous diagnosis of high grade cervical intraepithelial neoplasia (CIN3) and both men and women treated for nonā€cervical preā€invasive anoā€genital disease. All CIN3 cases diagnosed in 1989ā€2015 in Scotland were extracted from the Scottish cancer registry (SMR06). All cases of preā€invasive penile, anal, vulval, and vaginal disease diagnosed in 1990ā€2015 were identified within the NHS pathology databases in the two largest NHS health boards in Scotland. Both were linked to SMR06 to extract subsequent incidence of HPVaC following the diagnosis of CIN3 or preā€invasive disease. Standardised incidence ratios were calculated for the risk of acquiring HPVaC for the two atā€risk groups compared with the general Scottish population. Among 69714 females in Scotland diagnosed with CIN3 (890360.9 personā€years), 179 developed nonā€cervical HPVaC. CIN3 cases were at 3.2ā€fold (95% CI: 2.7 to 3.7) increased risk of developing nonā€cervical HPVaC, compared to the general female population. Among 1235 patients diagnosed with nonā€cervical preā€invasive disease (9667.4 personā€years), 47 developed HPVaC. Individuals with nonā€cervical preā€invasive disease had a substantially increased risk of developing HPVaC ā€ 15.5ā€fold (95% CI: 11.1 to 21.1) increased risk for females and 28ā€fold (11.3 to 57.7) increased risk for males. We report a significant additional risk of HPVā€associated cancer in those have been diagnosed with preā€invasive HPVā€associated lesions including but not confined to the cervix. Uncovering the natural history of preā€invasive disease has potential for determining screening, prevention and treatment

    Accelerometer-measured physical activity and sedentary time among children and their parents in the UK before and after COVID-19 lockdowns:a natural experiment

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    BACKGROUND: Restrictions due to the coronavirus disease 2019 (COVID-19) pandemic reduced physical activity provision for both children and their parents. Recent studies have reported decreases in physical activity levels during lockdown restrictions, but these were largely reliant on self-report methods, with data collected via unrepresentative self-report surveys. The post-pandemic impacts on childrenā€™s activity levels remain unknown. A key question is how active children become once lockdown restrictions are lifted. METHODS: Active-6 is a repeated cross-sectional natural experiment. Accelerometer data from 1296 children aged 10ā€“11 and their parents were collected in 50 schools in the Greater Bristol area, UK in March 2017-May 2018 (pre-COVID-19 comparator group), and compared to 393 children aged 10ā€“11 and parents in 23 of the same schools, collected in May-December 2021. Mean minutes of accelerometer-measured moderate-to-vigorous physical activity (MVPA) were derived for weekdays and weekend and compared pre- and post-lockdown via linear multilevel models. RESULTS: After adjusting for seasonality, accelerometer wear time and child/parent demographics, childrenā€™s mean weekday and weekend MVPA were 7.7Ā min (95% CI: 3.5 to 11.9) and 6.9Ā min (95% CI: 0.9 to 12.9) lower in 2021 than in 2018, respectively, while sedentary time was higher by 25.4Ā min (95% CI: 15.8 to 35.0) and 14.0Ā min (95% CI: 1.5 to 26.5). There was no evidence that differences varied by child gender or household education. There was no significant difference in parentsā€™ MVPA or sedentary time, either on weekdays or weekends. CONCLUSIONS: Childrenā€™s MVPA was lower by 7ā€“8Ā min/day in 2021 once restrictions were lifted than before the pandemic for all groups, on both weekdays and weekends. Previous research has shown that there is an undesirable age-related decline in childrenā€™s physical activity. The 8-min difference reported here would be broadly comparable to the decline that would have previously been expected to occur over a three-year period. Parentsā€™ physical activity was similar to pre-pandemic levels. Our results suggest that despite easing of restrictions, childrenā€™s activity levels have not returned to pre-pandemic levels. There is an urgent need to understand why these changes have occurred and how long they are maintained. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12966-022-01290-4

    Understanding Evolutionary Impacts of Seasonality: An Introduction to the Symposium

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    Seasonality is a critically important aspect of environmental variability, and strongly shapes all aspects of life for organisms living in highly seasonal environments. Seasonality has played a key role in generating biodiversity, and has driven the evolution of extreme physiological adaptations and behaviors such as migration and hibernation. Fluctuating selection pressures on survival and fecundity between summer and winter provide a complex selective landscape, which can be met by a combination of three outcomes of adaptive evolution: genetic polymorphism, phenotypic plasticity, and bet-hedging. Here, we have identified four important research questions with the goal of advancing our understanding of evolutionary impacts of seasonality. First, we ask how characteristics of environments and species will determine which adaptive response occurs. Relevant characteristics include costs and limits of plasticity, predictability, and reliability of cues, and grain of environmental variation relative to generation time. A second important question is how phenological shifts will amplify or ameliorate selection on physiological hardiness. Shifts in phenology can preserve the thermal niche despite shifts in climate, but may fail to completely conserve the niche or may even expose life stages to conditions that cause mortality. Considering distinct environmental sensitivities of life history stages will be key to refining models that forecast susceptibility to climate change. Third, we must identify critical physiological phenotypes that underlie seasonal adaptation and work toward understanding the genetic architectures of these responses. These architectures are key for predicting evolutionary responses. Pleiotropic genes that regulate multiple responses to changing seasons may facilitate coordination among functionally related traits, or conversely may constrain the expression of optimal phenotypes. Finally, we must advance our understanding of how changes in seasonal fluctuations are impacting ecological interaction networks. We should move beyond simple dyadic interactions, such as predator prey dynamics, and understand how these interactions scale up to affect ecological interaction networks. As global climate change alters many aspects of seasonal variability, including extreme events and changes in mean conditions, organisms must respond appropriately or go extinct. The outcome of adaptation to seasonality will determine responses to climate change
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