521 research outputs found
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Faecal glucocorticoid metabolite profiles in diademed sifakas increase during seasonal fruit scarcity with interactive effects of age/sex class and habitat degradation
We measured faecal glucocorticoid metabolites (GCs) in Critically Endangered diademed sifaka to understand how food availability, nutritional intake and habitat disturbance impact stress physiology. GCs elevated with food scarcity and correlated negatively with feeding time. Attenuated GCs in fragmented forest groups suggest a downregulated response to a chronically poor environment. Abstract Glucocorticoids are metabolic byproducts of animals' physiological responses to ecological or social challenges and are thought to represent an adaptive response allowing beneficial responses to short-term challenges. Glucocorticoid metabolites (GCs) can be assayed non-invasively through faeces and therefore can be a useful tool to gauge the health of populations experiencing natural and/or anthropogenic stressors. However, the response of GCs to anthropogenic stressors varies, with both higher and lower GC levels reported. Here, we describe variation in GC secretion within eight diademed sifaka (Propithecus diadema) groups across 1 year. These groups span a gradient of anthropogenic habitat disturbance, including groups in continuous forest (CONT') and disturbed fragments (FRAG'), and indicators of health suggest that FRAG groups are negatively impacted by habitat disturbance. We monitored phenology, used focal animal follows to quantify diet and collected faeces (n = 547) from which we quantified GC content using enzyme immunoassay. All groups showed elevated lean-season GCs, but with a single, brief peak. GCs were inversely correlated with feeding time. No overall effect of habitat (CONT vs. FRAG) was found, but the lean-season peak was significantly higher in CONT groups. There was a significant season*age-sex interaction; adult females had an attenuated lean-season response compared with groupmates. The observed lean-season challenge' is consistent with previous lemur studies, as well as mammals in general. Low and largely invariable GC levels in FRAG, within the context of observed health and nutritional declines, suggest that FRAG groups employ a strategy whereby the adrenal response to stressors is downregulated. More research is needed to contextualize our observations of GC variation and health on an individual level, both in terms of corroborating evidence for ecological and social stressors, and longer-term quantification of reproductive success and fitness.National Geographic Society Committee for Research and Exploration; Rowe/Wright Primate Fund; University of Arizona School of Anthropology; Institute for the Environment; Provost's Office; College of Social and Behavioral Sciences; BIO5Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Biogeography and Character Evolution of the Ciliate Genus Euplotes (Spirotrichea, Euplotia), with Description of Euplotes curdsi sp. nov.
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
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
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
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
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
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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First Direct Observation of Muon Antineutrino Disappearance
This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν̅ _μ production, accumulating an exposure of 1.71×10^(20) protons on target. In the Far Detector, 97 charged current ν̅ _μ events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm̅ 2|= [3.36=_(-0.40)^(+0.46)(stat)±0.06(syst)]x10^(-3)eV^2,sin^2(2θ̅)=0.86 _(-0.12)^(+0.11)(stat)±0.01(syst). The MINOS ν̅ _μ and ν̅ _μ measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters
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Measurement of the underground atmospheric muon charge ratio using the MINOS Near Detector
The magnetized MINOS Near Detector, at a depth of 225 mwe, is used to measure the atmospheric muon charge ratio. The ratio of observed positive to negative atmospheric muon rates, using 301 days of data, is measured to be 1.266±0.001(stat)_(-0.014)^(+0.015)(syst). This measurement is consistent with previous results from other shallow underground detectors and is 0.108±0.019(stat+syst) lower than the measurement at the functionally identical MINOS Far Detector at a depth of 2070 mwe. This increase in charge ratio as a function of depth is consistent with an increase in the fraction of muons arising from kaon decay for increasing muon surface energie
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Active to Sterile Neutrino Mixing Limits from Neutral-Current Interactions in MINOS
Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of 7.07×10^(20) protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of 754±28(stat)±37(syst) for oscillations among three active flavors. The fraction f_s of disappearing ν_μ that may transition to ν_s is found to be less than 22% at the 90% C.L
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