56 research outputs found

    Seabird movement reveals the ecological footprint of fishing vessels.

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    Exploitation of the seas is currently unsustainable, with increasing demand for marine resources placing intense pressure on the Earth's largest ecosystem [1]. The scale of anthropogenic effects varies from local to entire ocean basins [1-3]. For example, discards of commercial capture fisheries can have both positive and negative impacts on scavengers at the population and community-level [2-6], although this is driven by individual foraging behaviour [3,7]. Currently, we have little understanding of the scale at which individual animals initiate such behaviours. We use the known interaction between fisheries and a wide-ranging seabird, the Northern gannet Morus bassanus[3], to investigate how fishing vessels affect individual birds' behaviours in near real-time. We document the footprint of fishing vessels' (≥15 m length) influence on foraging decisions (≤11 km), and a potential underlying behavioural mechanism, by revealing how birds respond differently to vessels depending on gear type and activity. Such influences have important implications for fisheries, including the proposed discard ban [8]), and wider marine management

    Bottom trawling at Whittard Canyon: Evidence for seabed modification, trawl plumes and food source heterogeneity

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    Fishing vessels are attracted to the dendritic Whittard Canyon system due to the abundance and diversity of species found there. Both midwater and bottom trawling are commonplace, including on deep canyon channel floors. Bottom trawling is identified here as a possible cause of changes to seafloor roughness along the canyon interfluves. An Arc Chord Ratio (ACR) rugosity index is calculated for the Whittard area and correlated with Vessel Monitoring System (VMS) data using various statistical models. Over higher slopes or rougher ground the heavily fished locations show a more homogeneous rugosity distribution than those lightly fished, indicating possible smoothing of the seabed. Bottom trawling activity on adjacent interfluves/shelf is known to generate energetic turbid, sediment plumes within the canyon branches to 2500 m depth, with elevated Suspended Particulate Matter (SPM) concentrations in the water column up to 400 m above the seabed. Lipid biomarker analysis of organic material collected from these plumes showed higher concentrations of total lipids at sites that are intensively trawled (east). In comparison to sites that are less intensively trawled (west), higher contributions of fatty alcohols were detected. While lower concentrations of unsaturated fatty acids were detected, biomarkers indicative of phytoplankton accounted for 93.4 ± 0.7% of total lipids identified from eastern samples suggesting rapid transport of labile compounds. Results presented here suggest that intensive trawling induced changes to sediment transport will complicate the interpretation of biogeochemical property distributions at canyon systems, particularly from single surveys. Anthropogenically generated heterogeneity in sediment supply and character will also impact on habitat suitability for resident ecosystems

    Sexual Mismatch Between Vessel-Associated Foraging and Discard Consumption in a Marine Top Predator

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    Sex differences in diet and foraging behaviour are common in sexually dimorphic species, often driven by differences in the cost of locomotion or ability to exploit different ecological niches. However, sex-specific foraging strategies also occur in monomorphic or slightly dimorphic species where the drivers are poorly understood. Here, we study sex differences in foraging of northern gannets (Morus bassanus), where females are only slightly heavier than males. Using concurrently tracked gannets (298 full foraging trips from 81 individuals) and fishing vessels across 5 years, we quantify individual-based vessel-associated putative foraging, and relate this to discard consumption. We found a significant positive relationship between time spent in vessel-associated foraging and discard consumption for both sexes. However, while females showed greater proportions of vessel-associated foraging than males, discarded fish contributed less to the diet of females in all years. These results contrast with previous suggestions that female gannets interact with vessels less often than males, and are consistent with competitive exclusion of females from trawler-associated discards. Our findings give insight into sexual differences in foraging behaviour in the absence of dimorphism that are necessary to predict their response to environmental and anthropogenic changes

    Continued Decline of Malaria in The Gambia with Implications for Elimination

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    BACKGROUND: A substantial decline in malaria was reported to have occurred over several years until 2007 in the western part of The Gambia, encouraging consideration of future elimination in this previously highly endemic region. Scale up of interventions has since increased with support from the Global Fund and other donors. METHODOLOGY/PRINCIPAL FINDINGS: We continued to examine laboratory records at four health facilities previously studied and investigated six additional facilities for a 7 year period, adding data from 243,707 slide examinations, to determine trends throughout the country until the end of 2009. We actively detected infections in a community cohort of 800 children living in rural villages throughout the 2008 malaria season, and assayed serological changes in another rural population between 2006 and 2009. Proportions of malaria positive slides declined significantly at all of the 10 health facilities between 2003 (annual mean across all sites, 38.7%) and 2009 (annual mean, 7.9%). Statistical modelling of trends confirmed significant seasonality and decline over time at each facility. Slide positivity was lowest in 2009 at all sites, except two where lowest levels were observed in 2006. Mapping households of cases presenting at the latter sites in 2007-2009 indicated that these were not restricted to a few residual foci. Only 2.8% (22/800) of a rural cohort of children had a malaria episode in the 2008 season, and there was substantial serological decline between 2006 and 2009 in a separate rural area. CONCLUSIONS: Malaria has continued to decline in The Gambia, as indicated by a downward trend in slide positivity at health facilities, and unprecedented low incidence and seroprevalence in community surveys. We recommend intensification of control interventions for several years to further reduce incidence, prior to considering an elimination programme

    Impact of national malaria control scale-up programmes in Africa: magnitude and attribution of effects

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    <p>Abstract</p> <p>Background</p> <p>Since 2005, malaria control scale-up has progressed in many African countries. Controlled studies of insecticide-treated mosquito nets (ITNs), indoor residual spraying (IRS), intermittent preventive treatment during pregnancy (IPTp) and malaria case management suggested that when incorporated into national programmes a dramatic health impact, likely more than a 20% decrease in all-cause childhood mortality, was possible. To assess the extent to which national malaria programmes are achieving impact the authors reviewed African country programme data available through 2009.</p> <p>Methods</p> <p>National survey data, published literature, and organization or country reports produced during 2000-2009 were reviewed to assess available malaria financing, intervention delivery, household or target population coverage, and reported health benefits including infection, illness, severe anaemia, and death.</p> <p>Results</p> <p>By the end of 2009, reports were available for ITN household ownership (n = 34) and IPTp use (n = 27) in malaria-endemic countries in Africa, with at least two estimates (pre-2005 and post-2005 intervals). Information linking IRS and case management coverage to impact were more limited. There was generally at least a three-fold increase in household ITN ownership across these countries between pre-2005 (median of 2.4% of households with at least one ITN) and post-2005 (median of 32.5% of households with at least one ITN). Ten countries had temporal data to assess programme impact, and all reported progress on at least one impact indicator (typically on mortality); in under-five year mortality rates most observed a decline of more than 20%. The causal relationship between malaria programme scale-up and reduced child illness and mortality rates is supported by biologic plausibility including mortality declines consistent with experience from intervention efficacy trials, consistency of findings across multiple countries and different epidemiologic settings, and temporal congruity where morbidity and mortality declines have been documented in the 18 to 36 months following intervention scale-up.</p> <p>Conclusions</p> <p>Several factors potentially have contributed to recent health improvement in African countries, but there is substantial evidence that achieving high malaria control intervention coverage, especially with ITNs and targeted IRS, has been the leading contributor to reduced child mortality. The documented impact provides the evidence required to support a global commitment to the expansion and long-term investment in malaria control to sustain and increase the health impact that malaria control is producing in Africa.</p

    Adding value to under-utilised Irish fish roe: a physico-chemical and sensory comparison of cured Irish pollock (Pollachius pollachius) roe with commercial mullet (Mugil cephalus) and cod (Gadus morhua) products

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    peer reviewedIrish marine fish roe is generally discarded at sea or processed as low value-added fishmeal and not utilised as nutritious seafood ingredients. Locally sourced pollock roes were salted, air-dried (Mediterranean-style) and compared to similar commercial mullet and cod products for: weight; moisture content; pH; instrumental texture and colour; and sensory attributes. Raw pollock roes averaged 105 g (n = 25). Roes lost on average 3.1% moisture (w/w) after a 2-h salting period and 48.8% weight reduction was observed after an average 105 h air-drying time. The moisture content of pollock was not significantly different to commercial products. Average pH for pollock, mullet and cod products was 5.9, 5.4 and 5.7, respectively (P < 0.05). Pollock and mullet had similar hardness, but cod was significantly harder than both, when measured instrumentally. Total colour difference (ΔE*) between the surface of pollock and cod, and that of pollock and mullet was 7.5 and 3.0, respectively. Sensory assessment of sliced and powdered products, using 9-point hedonic and 5-point just-about-right (JAR) scales, was conducted with 38 consumers. Pollock received the highest scores for overall liking and intention to purchase compared to commercial mullet and cod products, averaging 5.6, 5.6 and 4.9, respectively, for sliced roe products, and 6.3, 5.3 and 6.1 for powdered products. Penalty analysis of JAR showed “overall liking” was impacted by the flavour being “too fishy”. In conclusion, pollock had similar characteristics and acceptable sensory attributes compared to commercial products presenting opportunities to expand the range of value-added roe products (e.g., trout, salmon) available, while also contributing to waste reduction

    Computational Identification of Transcriptional Regulators in Human Endotoxemia

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    One of the great challenges in the post-genomic era is to decipher the underlying principles governing the dynamics of biological responses. As modulating gene expression levels is among the key regulatory responses of an organism to changes in its environment, identifying biologically relevant transcriptional regulators and their putative regulatory interactions with target genes is an essential step towards studying the complex dynamics of transcriptional regulation. We present an analysis that integrates various computational and biological aspects to explore the transcriptional regulation of systemic inflammatory responses through a human endotoxemia model. Given a high-dimensional transcriptional profiling dataset from human blood leukocytes, an elementary set of temporal dynamic responses which capture the essence of a pro-inflammatory phase, a counter-regulatory response and a dysregulation in leukocyte bioenergetics has been extracted. Upon identification of these expression patterns, fourteen inflammation-specific gene batteries that represent groups of hypothetically ‘coregulated’ genes are proposed. Subsequently, statistically significant cis-regulatory modules (CRMs) are identified and decomposed into a list of critical transcription factors (34) that are validated largely on primary literature. Finally, our analysis further allows for the construction of a dynamic representation of the temporal transcriptional regulatory program across the host, deciphering possible combinatorial interactions among factors under which they might be active. Although much remains to be explored, this study has computationally identified key transcription factors and proposed a putative time-dependent transcriptional regulatory program associated with critical transcriptional inflammatory responses. These results provide a solid foundation for future investigations to elucidate the underlying transcriptional regulatory mechanisms under the host inflammatory response. Also, the assumption that coexpressed genes that are functionally relevant are more likely to share some common transcriptional regulatory mechanism seems to be promising, making the proposed framework become essential in unravelling context-specific transcriptional regulatory interactions underlying diverse mammalian biological processes

    Functional characterization of a multi-cancer risk locus on chr5p15.33 reveals regulation of TERT by ZNF148

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    Genome wide association studies (GWAS) have mapped multiple independent cancer susceptibility loci to chr5p15.33. Here, we show that fine-mapping of pancreatic and testicular cancer GWAS within one of these loci (Region 2 in CLPTM1L) focuses the signal to nine highly correlated SNPs. Of these, rs36115365-C associated with increased pancreatic and testicular but decreased lung cancer and melanoma risk, and exhibited preferred protein-binding and enhanced regulatory activity. Transcriptional gene silencing of this regulatory element repressed TERT expression in an allele-specific manner. Proteomic analysis identifies allele-preferred binding of Zinc finger protein 148 (ZNF148) to rs36115365-C, further supported by binding of purified recombinant ZNF148. Knockdown of ZNF148 results in reduced TERT expression, telomerase activity and telomere length. Our results indicate that the association with chr5p15.33-Region 2 may be explained by rs36115365, a variant influencing TERT expression via ZNF148 in a manner consistent with elevated TERT in carriers of the C allele

    Impact of inactivity and exercise on the vasculature in humans

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    The effects of inactivity and exercise training on established and novel cardiovascular risk factors are relatively modest and do not account for the impact of inactivity and exercise on vascular risk. We examine evidence that inactivity and exercise have direct effects on both vasculature function and structure in humans. Physical deconditioning is associated with enhanced vasoconstrictor tone and has profound and rapid effects on arterial remodelling in both large and smaller arteries. Evidence for an effect of deconditioning on vasodilator function is less consistent. Studies of the impact of exercise training suggest that both functional and structural remodelling adaptations occur and that the magnitude and time-course of these changes depends upon training duration and intensity and the vessel beds involved. Inactivity and exercise have direct “vascular deconditioning and conditioning” effects which likely modify cardiovascular risk
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