521 research outputs found

    Biogeography and Character Evolution of the Ciliate Genus Euplotes (Spirotrichea, Euplotia), with Description of Euplotes curdsi sp. nov.

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    Ciliates comprise a diverse and ecologically important phylum of unicellular protists. One of the most specious and best-defined genera is Euplotes, which constitutes more than 70 morphospecies, many of which have never been molecularly tested. The increasing number of described Euplotes taxa emphasizes the importance for detailed characterizations of new ones, requiring standardized morphological observations, sequencing of molecular markers and careful comparison with previous literature. Here we describe Euplotes curdsi sp. nov., distinguishable by the combination of the following features: 45±65 μm length, oval or elongated shape with both ends rounded, narrow peristome with 25±34 adoral membranelles, conspicuous paroral membrane, double-eurystomus dorsal argyrome type, 6±7 dorsolateral kineties and 10 frontoventral cirri. Three populations of the novel species have been found in brackish and marine samples in the Mediterranean and the White Sea. We provide the SSU rRNA gene sequences of these populations, and an updated phylogeny of the genus Euplotes. Using the molecular phylogenetic tree, we inferred aspects of the biogeographical history of the genus and the evolution of its most important taxonomic characters in order to provide a frame for future descriptions. Ultimately, these data reveal recurrent trends of freshwater invasion and highlight the dynamic, yet convergent, morphological evolution of Euplotes

    Optimisation of Interface Roughness and Coating Thickness to Maximise Coating-Substrate Adhesion - A Failure Prediction and Reliability Assessment Modelling

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    This paper addresses a novel modelling technique which is based on a multidisciplinary approach to predict the coating-substrate adhesion. It proposes new equations governing coating debondment that combines material science concepts with and solid mechanics concepts. The effects of two parameters i.e. interface roughness λ and coating thickness h on coating-substrate adhesion has been analysed. The reliability of newly developed technique has been validated by comparison with the experimental results

    Public Benefits of Undeveloped Lands on Urban Outskirts: Non-Market Valuation Studies and their Role in Land Use Plans

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    Over the past three decades, the economics profession has developed methods for estimating the public benefits of green spaces, providing an opportunity to incorporate such information into land-use planning. While federal regulations routinely require such estimates for major regulations, the extent to which they are used in local land use plans is not clear. This paper reviews the literature on public values for lands on urban outskirts, not just to survey their methods or empirical findings, but to evaluate the role they have played--or have the potential to play-- in actual land use plans. Based on interviews with authors and representatives of funding agencies and local land trusts, it appears that academic work has had a mixed reception in the policy world. Reasons for this include a lack of interest in making academic work accessible to policy makers, emphasizing revealed preference methods which are inconsistent with policy priorities related to nonuse values, and emphasis on benefit-cost analyses. Nevertheless, there are examples of success stories that illustrate how such information can play a vital role in the design of conservation policies. Working Paper 07-2

    Novel opsin gene variation in large-bodied, diurnal lemurs

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    Some primate populations include both trichromatic and dichromatic (red-green colour blind) individuals due to allelic variation at the X-linked opsin locus. This polymorphic trichromacy is well described in day-active New World monkeys. Less is known about colour vision in Malagasy lemurs, but, unlike New World monkeys, only some day-active lemurs are polymorphic, while others are dichromatic. The evolutionary pressures underlying these differences in lemurs are unknown, but aspects of species ecology, including variation in activity pattern, are hypothesized to play a role. Limited data on X-linked opsin variation in lemurs make such hypotheses difficult to evaluate. We provide the first detailed examination of X-linked opsin variation across a lemur clade (Indriidae). We sequenced the X-linked opsin in the most strictly diurnal and largest extant lemur, Indri indri, and nine species of smaller, generally diurnal indriids (Propithecus). Although nocturnal Avahi (sister taxon to Propithecus) lacks a polymorphism, at least eight species of diurnal indriids have two or more X-linked opsin alleles. Four rainforest-living taxa-I. indri and the three largest Propithecus species-have alleles not previously documented in lemurs. Moreover, we identified at least three opsin alleles in Indri with peak spectral sensitivities similar to some New World monkeys

    Context, mechanisms and outcomes in end of life care for people with advanced dementia

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    yesBackground: The majority of people with dementia in the UK die in care homes. The quality of end of life care in these environments is often suboptimal. The aim of the present study was to explore the context, mechanisms and outcomes for providing good palliative care to people with advanced dementia residing in UK care homes from the perspective of health and social care providers. Method: The design of the study was qualitative which involved purposive sampling of health care professionals to undertake interactive interviews within a realist framework. Interviews were completed between September 2012 and October 2013 and were thematically analysed and then conceptualised according to context, mechanisms and outcomes. The settings were private care homes and services provided by the National Health Service including memory clinics, mental health and commissioning services in London, United Kingdom. The participants included 14 health and social care professionals including health care assistants, care home managers, commissioners for older adults’ services and nursing staff. Results: Good palliative care for people with advanced dementia is underpinned by the prioritisation of psychosocial and spiritual care, developing relationships with family carers, addressing physical needs including symptom management and continuous, integrated care provided by a multidisciplinary team. Contextual factors that detract from good end of life care included: an emphasis on financial efficiency over person-centred care; a complex health and social care system, societal and family attitudes towards staff; staff training and experience, governance and bureaucratisation; complexity of dementia; advance care planning and staff characteristics. Mechanisms that influence the quality of end of life care include: level of health care professionals’ confidence, family uncertainty about end of life care, resources for improving end of life care and supporting families, and uncertainty about whether dementia specific palliative care is required. Conclusions: Contextual factors regarding the care home environment may be obdurate and tend to negatively impact on the quality of end of life dementia care. Local level mechanisms may be more amenable to improvement. However, systemic changes to the care home environment are necessary to promote consistent, equitable and sustainable high quality end of life dementia care across the UK care home secto

    Strong interface-induced spin-orbit coupling in graphene on WS2

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    Interfacial interactions allow the electronic properties of graphene to be modified, as recently demonstrated by the appearance of satellite Dirac cones in the band structure of graphene on hexagonal boron nitride (hBN) substrates. Ongoing research strives to explore interfacial interactions in a broader class of materials in order to engineer targeted electronic properties. Here we show that at an interface with a tungsten disulfide (WS2) substrate, the strength of the spin-orbit interaction (SOI) in graphene is very strongly enhanced. The induced SOI leads to a pronounced low-temperature weak anti-localization (WAL) effect, from which we determine the spin-relaxation time. We find that spin-relaxation time in graphene is two-to-three orders of magnitude smaller on WS2 than on SiO2 or hBN, and that it is comparable to the intervalley scattering time. To interpret our findings we have performed first-principle electronic structure calculations, which both confirm that carriers in graphene-on-WS2 experience a strong SOI and allow us to extract a spin-dependent low-energy effective Hamiltonian. Our analysis further shows that the use of WS2 substrates opens a possible new route to access topological states of matter in graphene-based systems.Comment: Originally submitted version in compliance with editorial guidelines. Final version with expanded discussion of the relation between theory and experiments to be published in Nature Communication
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