1,302 research outputs found

    Epibenthic and mobile species colonisation of a geotextile artificial surf reef on the south coast of England

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    With increasing coastal infrastructure and use of novel materials there is a need to investigate the colonisation of assemblages associated with new structures, how these differ to natural and other artificial habitats and their potential impact on regional biodiversity. The colonisation of Europe’s first artificial surf reef (ASR) was investigated at Boscombe on the south coast of England (2009–2014) and compared with assemblages on existing natural and artificial habitats. The ASR consists of geotextile bags filled with sand located 220m offshore on a sandy sea bed at a depth of 0-5m. Successional changes in epibiota were recorded annually on differently orientated surfaces and depths using SCUBA diving and photography. Mobile faunal assemblages were sampled using Baited Remote Underwater Video (BRUV). Distinct stages in colonisation were observed, commencing with bryozoans and green algae which were replaced by red algae, hydroids and ascidians, however there were significant differences in assemblage structure with depth and orientation. The reef is being utilised by migratory, spawning and juvenile life-history stages of fish and invertebrates. The number of non-native species was larger than on natural reefs and other artificial habitats and some occupied a significant proportion of the structure. The accumulation of 180 benthic and mobile taxa, recorded to date, appears to have arisen from a locally rich and mixed pool of native and non-native species. Provided no negative invasive impacts are detected on nearby protected reefs the creation of novel yet diverse habitats may be considered a beneficial outcome

    Novel polymorphisms influencing transcription of the human CHRM2 gene in airway smooth muscle

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    Muscarinic receptors are a functionally important family of G-protein-coupled receptors. Using a combination of rapid amplification of 5′ cDNA ends and reporter gene assays, we characterized the 5′ untranslated region of the CHRM2 gene as expressed in human airway smooth muscle (HASM) cells. A splice site is present 46 bp upstream from the ATG start codon. Five exons with alternative splicing patterns are present upstream of this splice site, separated by introns ranging from 87 bp to > 145 kb. There is evidence for the gene being under the control of a TATA-less promoter with Sp1, GATA, and activator protein-2 binding sites. Multiple transcription start sites (TSSs) were identified. We identified a novel 0.5-kb hypervariable region located 648 bp upstream of the most 5′ TSS, a multiallelic (CA) tandem repeat 96 bp downstream of the most 5′ TSS, and a common C→A SNP located 136 bp upstream of the most 5′ TSS. Functional studies in primary HASM cells and the BEAS-2B cell line demonstrated highest promoter activity to be upstream of the most 3′ TSS, with potential repressor elements operating in a cell type-dependent manner, located upstream of the most 5′ TSS. We present functional data to show that the CA repeat may influence the transcription of the gene in HASM and BEAS-2B cells.peer-reviewe

    Analytical solution of a model for complex food webs

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    We investigate numerically and analytically a recently proposed model for food webs [Nature {\bf 404}, 180 (2000)] in the limit of large web sizes and sparse interaction matrices. We obtain analytical expressions for several quantities with ecological interest, in particular the probability distributions for the number of prey and the number of predators. We find that these distributions have fast-decaying exponential and Gaussian tails, respectively. We also find that our analytical expressions are robust to changes in the details of the model.Comment: 4 pages (RevTeX). Final versio

    Evaluation of an internet-based behavioral intervention to improve psychosocial health outcomes in children with insomnia (Better Nights, Better Days): Protocol for a randomized controlled trial

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    Background: Up to 25% of 1- to 10-year-old children experience insomnia (ie, resisting bedtime, trouble falling asleep, night awakenings, and waking too early in the morning). Insomnia can be associated with excessive daytime sleepiness and negative effects on daytime functioning across multiple domains (eg, behavior, mood, attention, and learning). Despite robust evidence supporting the effectiveness of behavioral treatments for insomnia in children, very few children with insomnia receive these treatments, primarily due to a shortage of available treatment resources. Objective: The Better Nights, Better Days (BNBD) internet-based program provides a readily accessible electronic health (eHealth) intervention to support parents in providing evidence-based care for insomnia in typically developing children. The purpose of the randomized controlled trial (RCT) is to evaluate the effectiveness of BNBD in treating insomnia in children aged between 1 and 10 years. Methods: BNBD is a fully automated program, developed based on evidence-based interventions previously tested by the investigators, as well as on the extant literature on this topic. We describe the 2-arm RCT in which participants (500 primary caregivers of children with insomnia residing in Canada) are assigned to intervention or usual care. Results: The effects of this behavioral sleep eHealth intervention will be assessed at 4 and 8 months postrandomization. Assessment includes both sleep (actigraphy, sleep diary) and daytime functioning of the children and daytime functioning of their parents. Results will be reported using the standards set out in the Consolidated Standards of Reporting Trials statement. Conclusions: If the intervention is supported by the results of the RCT, we plan to commercialize this program so that it is sustainable and available at a low cost to all families with internet access

    Caltech Faint Galaxy Redshift Survey. XI. The Merger Rate to Redshift 1 from Kinematic Pairs

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    The rate of mass accumulation due to galaxy merging depends on the mass, density, and velocity distribution of galaxies in the near neighborhood of a host galaxy. The fractional luminosity in kinematic pairs combines all of these effects in a single estimator that is relatively insensitive to population evolution. Here we use a k-corrected and evolution-compensated volume-limited sample having an R-band absolute magnitude of M^(k,e)_R ≤ -19.8 + 5 log h mag drawing about 300 redshifts from the Caltech Faint Galaxy Redshift Survey and 3000 from the Canadian Network for Observational Cosmology field galaxy survey to measure the rate and redshift evolution of merging. The combined sample has an approximately constant comoving number and luminosity density from redshift 0.1 to 1.1 (Ω_M = 0.2, Ω_Λ = 0.8); hence, any merger evolution will be dominated by correlation and velocity evolution, not density evolution. We identify kinematic pairs with projected separations less than either 50 or 100 h^(-1) kpc and rest-frame velocity differences of less than 1000 km s^(-1). The fractional luminosity in pairs is modeled as f_L(Δv, r_p, M^(k,e)_τ)(1 + z)^(m,L), where [f_L, m_L] are [0.14 ± 0.07, 0 ± 1.4] and [0.37 ± 0.7, 0.1 ± 0.5] for r_p ≤ 50 and 100 h^(-1) kpc, respectively (Ω_M = 0.2, Ω_Λ = 0.8). The value of mL is about 0.6 larger if Λ = 0. To convert these redshift-space statistics to a merger rate, we use the data to derive a conversion factor to a physical space pair density, a merger probability, and a mean in-spiral time. The resulting mass accretion rate per galaxy (M_1, M_2 ≥ 0.2M*) is 0.02 ± 0.01(1 + z)^(0.1±0.5)M* Gyr^(-1). Present-day high-luminosity galaxies therefore have accreted approximately 0.15M* of their mass over the approximately 7 Gyr to redshift 1. Since merging is likely only weakly dependent on the host mass, the fractional effect, δM/M 0.15M*/M, is dramatic for lower mass galaxies but is, on the average, effectively perturbative for galaxies above 1M*

    The impact of the COVID-19 pandemic on self-harm and suicidal behaviour: update of living systematic review

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    Background: The COVID-19 pandemic has caused considerable morbidity, mortality and disruption to people’s lives around the world. There are concerns that rates of suicide and suicidal behaviour may rise during and in its aftermath. Our living systematic review synthesises findings from emerging literature on incidence and prevalence of suicidal behaviour as well as suicide prevention efforts in relation to COVID-19, with this iteration synthesising relevant evidence up to 19th October 2020.Method: Automated daily searches feed into a web-based database with screening and data extraction functionalities. Eligibility criteria include incidence/prevalence of suicidal behaviour, exposure-outcome relationships and effects of interventions in relation to the COVID-19 pandemic. Outcomes of interest are suicide, self-harm or attempted suicide and suicidal thoughts. No restrictions are placed on language or study type, except for single-person case reports. We exclude one-off cross-sectional studies without either pre-pandemic measures or comparisons of COVID-19 positive vs. unaffected individuals.Results: Searches identified 6,226 articles. Seventy-eight articles met our inclusion criteria. We identified a further 64 relevant cross-sectional studies that did not meet our revised inclusion criteria. Thirty-four articles were not peer-reviewed (e.g. research letters, pre-prints). All articles were based on observational studies.There was no consistent evidence of a rise in suicide but many studies noted adverse economic effects were evolving. There was evidence of a rise in community distress, fall in hospital presentation for suicidal behaviour and early evidence of an increased frequency of suicidal thoughts in those who had become infected with COVID-19.Conclusions: Research evidence of the impact of COVID-19 on suicidal behaviour is accumulating rapidly. This living review provides a regular synthesis of the most up-to-date research evidence to guide public health and clinical policy to mitigate the impact of COVID-19 on suicide risk as the longer term impacts of the pandemic on suicide risk are researched

    Hadron yields and spectra in Au+Au collisions at the AGS

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    Inclusive double differential multiplicities and rapidity density distributions of hadrons are presented for 10.8 A GeV/c Au+Au collisions as measured at the AGS by the E877 collaboration. The results indicate that large amounts of stopping and collective transverse flow effects are present. The data are also compared to the results from the lighter Si+Al system.Comment: 12 pages, latex, 10 figures, submitted to Nuclear Physics A (Quark Matter 1996 Proceedings

    Children\u27s Sleep during COVID-19: How Sleep Influences Surviving and Thriving in Families

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    Objective The COVID-19 pandemic has the potential to disrupt the lives of families and may have implications for children with existing sleep problems. As such, we aimed to: (1) characterize sleep changes during the COVID-19 pandemic in children who had previously been identified as having sleep problems, (2) identify factors contributing to sleep changes due to COVID-19 safety measures, and (3) understand parents and children s needs to support sleep during the pandemic. Methods Eighty-five Canadian parents with children aged 4 14 years participated in this explanatory sequential, mixed-methods study using an online survey of children s and parents sleep, with a subset of 16 parents, selected based on changes in their children s sleep, participating in semi-structured interviews. Families had previously participated in the Better Nights, Better Days (BNBD) randomized controlled trial. Results While some parents perceived their child s sleep quality improved during the COVID-19 pandemic (14.1%, n 12), many parents perceived their child s sleep had worsened (40.0%, n 34). Parents attributed children s worsened sleep to increased screen time, anxiety, and decreased exercise. Findings from semi-structured interviews highlighted the effect of disrupted routines on sleep and stress, and that stress reciprocally influenced children s and parents sleep. Conclusions The sleep of many Canadian children was affected by the first wave of the COVID-19 pandemic, with the disruption of routines influencing children s sleep. eHealth interventions, such as BNBD with modifications that address the COVID-19 context, could help families address these challenges
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