1,094 research outputs found

    Variation in foraging activity of Acanthochitona garnoti (Mollusca: Polyplacophora) from different habitats

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    Click on the link to view the abstract.S. Afc. J. Zool. 1997,32(3

    Wetland Connectivity and Macroinvertebrate Diversity

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    Wetlands are important in filtering pollutants from aquatic ecosystems and also serve as habitats for a diverse array of organisms. However, wetland-river networks are often subject to human disturbances such as dyke construction. These decreases in connectivity have the potential to impede movement of organisms and nutrients between habitats. This study examined how the food web structure and diversity of macroinvertebrate communities differ between wetland sites connected and disconnected to nearby rivers. According to macroinvertebrate surveys in wetlands connected to nearby rivers and dyked wetlands (not connected to nearby rivers), there is an increase in average species richness and diversity (Shannon index) in connected sites. This may be because wetland-river connections provide opportunities for species to enter adjacent ecosystems. I used stable isotope analyses to examine the impact of species diversity and connectivity on the nutrient source and trophic position of odonates (dragonflies and damselflies)- top predators in many wetlands. Because stable nitrogen isotope values (δ15N) increase by 3-5 ‰ with each trophic transfer, the offset in δ15N between odonates and amphipods (primary consumers in wetland food webs) served as a proxy for food chain length. Although there was not evidence to conclude that the offset in δ15 N is greater in connected wetlands, average Odonate δ15N values in sites connected to a river were higher than in dyked sites. This observed shift in δ15N may be an indication of different nitrogen inputs to connected and disconnected wetlands, specifically, the relative input of terrestrial (allochthonous) nutrients. Notably, amphipods are often assumed to be primary consumers in wetlands. However, amphipods in this study had variable δ15N values, providing evidence for the claim that they can function as both primary consumers and secondary-tertiary consumers. While managers increasingly promote the restoration of natural connectivity between wetlands and rivers, there are few studies showing the likely impacts to wetland food web structure. My research will help to fill this gap and provide a more solid foundation for management decisions aimed at preserving wetland biodiversity

    Gathering Empirical Evidence Concerning Links Between Computer Aided Design (CAD) and Creativity

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    Discussion is often reported concerning potential links between computer-aided designing and creativity, but there is a lack of systematic enquiry to gather empirical evidence concerning such links. This paper reports an indication of findings from other research studies carried out in contexts beyond general education that have sought evidence relating CAD and creativity. It describes the establishment of a framework for gathering empirical evidence to support the analysis of links between CAD and creativity, via the observation of creative behaviours, which was developed from published literature largely relating to the area of cognitive psychology. It notes some initial research findings concerning the use of this framework in analysing the use of CAD in postgraduate design projects completed at Loughborough University. These results demonstrate the occurrence of creative behaviours in association with the use of CAD when designing. Finally the significance of these results is discussed within the wider context of design modelling

    Mental Health Through Movement

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    Children’s mental health: ‘has become an issue of real concern, in the media and to both politicians and NHS leaders, over the last five years in particular. It has prompted numerous inquiries, reports, recommendations and pledges by politicians and NHS leaders to improve the situation’: https://www.theguardian.com/society/2018/nov/22/what-is-happening-withchildrens-mental-health On July 1st 2019, the Local Government Association released statistics to show that: ‘There were 205,720 cases where a child was identified as having a mental health issue in 2017/18, compared with 133,600 in 2014/15- up 54%’: https://www.local.gov.uk/about/news/councils-seeing-more-560-child-mentalhealth-cases-every-day It is within this context that the All-Party Parliamentary Group on A Fit and Healthy Childhood presents its 14th Report: ‘Positive Mental Health Through Movement’. With 1 in 10 children now having a mental health diagnosis and 1 in 4 an undiagnosed mental health issue, this, our third Report on the issue of child mental health, addresses the link between positive mental health and physical activity and movement experiences at a time when, paradoxically, today’s children and young people are more inactive and play less than ever before. The growing recognition of a link between mental health and movement is fortuitous because from September 2019, health education in English schools will be statutory alongside the expectation that they will offer their pupils at least 30 ‘active minutes’ per day. The APPG on A Fit and Healthy Childhood welcomes the change whilst recognising that those responsible for implementing the new strategy (including practitioners and families) will need guidance as they help children to develop individual strategies to address future adverse events and foster the positive sense of self that will enable them to lead fulfilled, healthy lives. This Report is therefore presented as a practical contribution to an essential debate. It offers new strategies against the persistence of historical and traditional ways of thinking; examines and collates best practice in the devolved Home Countries as well as the wider world and discusses exactly what is required to ensure that future child mental health strategy is holistic. It is respectful of equalities and is aware that the successful outcome of policies is entirely dependent upon the expertise and confidence of those tasked with the responsibility of delivering them. As the 21st century advances, we consider the effects of the digital age and its impact on children and young people’s mental health and wellbeing and the crucial role of parents and carers who want the best for their children in a societal climate where, all too often, fears of ‘nanny state’ meddling serve to isolate families who suffer in silence – until a disaster that may have been all too predictable and preventable overtakes them, making a private grief a public concern. The trajectory of progress in mental health policy has been ‘stop start’ rather than linear, with legislative change in 1959 and 1983, an increase in spending from 1997- 2010 and radical changes to child and adolescent mental health services (CAMHS) in 2000. The Wessely Independent Review of the Mental Health Act is another such milestone: https://www.gov.uk/government/groups/independent-review-of-the-mentalhealth-act The APPG on A Fit and Healthy Childhood anticipates that the Government will fulfil its pledge to parents, children and practitioners by introducing much needed mental health legislation - and that our trio of Reports and the holistic theme of this one will help to inform a strategy that works for 21st century children

    Topographic controls on the development of contemporaneous but contrasting basin-floor depositional architectures

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    Sediment-laden gravity-driven-flow deposits on the basin floor are typically considered to form either discrete lobes that stack compensationally, or packages of laterally extensive beds, commonly termed “sheets.” These end-member stacking patterns are documented in several basinfills. However, whether they can coexist in a single basin, or there are intermediate or transitional stacking patterns, is poorly understood. An analysis of depositional architecture and stacking patterns along a 70 km dip-oriented transect in the Upper Broto Turbidite System (Jaca Basin, south-central Pyrenees, Spain), which displays disparate stacking patterns in contemporaneous strata, is presented. Proximal and medial deposits are characterized by discrete packages of clean sandstones with sharp bed tops which exhibit predictable lateral and longitudinal facies changes, and are interpreted as lobes. Distal deposits comprise both relatively clean sandstones and hybrid beds that do not stack to form lobes. Instead, localized relatively thick hybrid beds are inferred to have inhibited the development of lobes. Hybrid beds developed under flows which were deflected and entrained carbonate mud substrate off a carbonate slope that bounded the basin to the south; evidence for this interpretation includes: 1) divergent paleoflow indicators and hummock-like features in individual beds; 2) a decrease in hybrid-bed thickness and abundance away from the lateral confining slope; 3) a carbonate-rich upper division, not seen in more proximal turbidites. The study demonstrates the co-occurrence of different styles of basin-floor stacking patterns in the same stratigraphic interval, and suggests that characterization of deep-water systems as either lobes or sheets is a false dichotomy

    Wellbeing and Nurture: Physical and Emotional Security in Childhood

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    While there is increasing concern about developing and reinforcing children’s physical and emotional security, researchers have been busy working out the actual mechanics, even at the cellular level, of how this can be achieved. This report will provide a concise update on what is known about optimising children’s wellbeing and security in childhood and far beyond. In examining the ways in which children grow and develop, we can learn from that because their physical and emotional wellbeing and therefore that of our future society will depend on it. This report represents what we have learned and we hope that it will contribute in a small way to the making of the brave new ‘post-Covid’ world

    A reference relative time-scale as an alternative to chronological age for cohorts with long follow-up

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    Background: Epidemiologists have debated the appropriate time-scale for cohort survival studies; chronological age or time-on-study being two such time-scales. Importantly, assessment of risk factors may depend on the choice of time-scale. Recently, chronological or attained age has gained support but a case can be made for a ‘reference relative time-scale’ as an alternative which circumvents difficulties that arise with this and other scales. The reference relative time of an individual participant is the integral of a reference population hazard function between time of entry and time of exit of the individual. The objective here is to describe the reference relative time-scale, illustrate its use, make comparison with attained age by simulation and explain its relationship to modern and traditional epidemiologic methods. Results: A comparison was made between two models; a stratified Cox model with age as the time-scale versus an un-stratified Cox model using the reference relative time-scale. The illustrative comparison used a UK cohort of cotton workers, with differing ages at entry to the study, with accrual over a time period and with long follow-up. Additionally, exponential and Weibull models were fitted since the reference relative time-scale analysis need not be restricted to the Cox model. A simulation study showed that analysis using the reference relative time-scale and analysis using chronological age had very similar power to detect a significant risk factor and both were equally unbiased. Further, the analysis using the reference relative time-scale supported fully-parametric survival modelling and allowed percentile predictions and mortality curves to be constructed. Conclusions: The reference relative time-scale was a viable alternative to chronological age, led to simplification of the modelling process and possessed the defined features of a good time-scale as defined in reliability theory. The reference relative time-scale has several interpretations and provides a unifying concept that links contemporary approaches in survival and reliability analysis to the traditional epidemiologic methods of Poisson regression and standardised mortality ratios. The community of practitioners has not previously made this connection

    Certified causes of death in patients with mesothelioma in South East England

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    Background: Mesothelioma is a highly fatal cancer that is caused by exposure to asbestos fibres. In many populations, the occurrence of mesothelioma is monitored with the use of mortality data from death certification. We examine certified causes of death of patients who have been diagnosed with mesothelioma, and assess the validity of death certification data as a proxy for mesothelioma incidence.Methods: We extracted mesothelioma registrations in the South East of England area between 2000 and 2004 from the Thames Cancer Registry database. We retained for analysis 2200 patients who had died at the time of analysis, after having excluded seven dead cases where the causes of death were not known to the cancer registry. The 2200 deaths were classified hierarchically to identify (1) mesothelioma deaths, (2) deaths certified as lung cancer deaths or (3) deaths from unspecified cancer, and (4) deaths from other causes.Results: 87% of the patients had mesothelioma mentioned on the death certificate. 6% had no mention of mesothelioma but included lung cancer as a cause of death. Another 6% had no mention of mesothelioma or lung cancer, but included an unspecified cancer as a cause of death. Lastly, 2% had other causes of death specified on the death certificate.Conclusion: This analysis suggests that official mortality data may underestimate the true occurrence of mesothelioma by around 10%

    Multicolour correlative imaging using phosphor probes

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    Correlative light and electron microscopy exploits the advantages of optical methods, such as multicolour probes and their use in hydrated live biological samples, to locate functional units, which are then correlated with structural details that can be revealed by the superior resolution of electron microscopes. One difficulty is locating the area imaged by the electron beam in the much larger optical field of view. Multifunctional probes that can be imaged in both modalities and thus register the two images are required. Phosphor materials give cathodoluminescence (CL) optical emissions under electron excitation. Lanthanum phosphate containing thulium or terbium or europium emits narrow bands in the blue, green and red regions of the CL spectrum; they may be synthesised with very uniform-sized crystals in the 10- to 50-nm range. Such crystals can be imaged by CL in the electron microscope, at resolutions limited by the particle size, and with colour discrimination to identify different probes. These materials also give emissions in the optical microscope, by multiphoton excitation. They have been deposited on the surface of glioblastoma cells and imaged by CL. Gadolinium oxysulphide doped with terbium emits green photons by either ultraviolet or electron excitation. Sixty-nanometre crystals of this phosphor have been imaged in the atmospheric scanning electron microscope (JEOL ClairScope). This probe and microscope combination allow correlative imaging in hydrated samples. Phosphor probes should prove to be very useful in correlative light and electron microscopy, as fiducial markers to assist in image registration, and in high/super resolution imaging studies

    Light smoking at base-line predicts a higher mortality risk to women than to men; evidence from a cohort with long follow-up

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    BACKGROUND: There is conflicting evidence as to whether smoking is more harmful to women than to men. The UK Cotton Workers’ Cohort was recruited in the 1960s and contained a high proportion of men and women smokers who were well matched in terms of age, job and length of time in job. The cohort has been followed up for 42 years. METHODS: Mortality in the cohort was analysed using an individual relative survival method and Cox regression. Whether smoking, ascertained at baseline in the 1960s, was more hazardous to women than to men was examined by estimating the relative risk ratio women to men, smokers to never smoked, for light (1–14), medium (15–24), heavy (25+ cigarettes per day) and former smoking. RESULTS: For all-cause mortality relative risk ratios were 1.35 for light smoking at baseline (95% CI 1.07-1.70), 1.15 for medium smoking (95% CI 0.89-1.49) and 1.00 for heavy smoking (95% CI 0.63-1.61). Relative risk ratios for light smoking at baseline for circulatory system disease was 1.42 (95% CI 1.01 to 1.98) and for respiratory disease was 1.89 (95% CI 0.99 to 3.63). Heights of participants provided no explanation for the gender difference. CONCLUSIONS: Light smoking at baseline was shown to be significantly more hazardous to women than to men but the effect decreased as consumption increased indicating a dose response relationship. Heavy smoking was equally hazardous to both genders. This result may help explain the conflicting evidence seen elsewhere. However gender differences in smoking cessation may provide an alternative explanation
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