858 research outputs found
Evidence of a metabolic memory to early-life dietary restriction in male C57BL/6 mice
<p>Background: Dietary restriction (DR) extends lifespan and induces beneficial metabolic effects in many animals. What is far less clear is whether animals retain a metabolic memory to previous DR exposure, that is, can early-life DR preserve beneficial metabolic effects later in life even after the resumption of ad libitum (AL) feeding. We examined a range of metabolic parameters (body mass, body composition (lean and fat mass), glucose tolerance, fed blood glucose, fasting plasma insulin and insulin-like growth factor 1 (IGF-1), insulin sensitivity) in male C57BL/6 mice dietary switched from DR to AL (DR-AL) at 11 months of age (mid life). The converse switch (AL-DR) was also undertaken at this time. We then compared metabolic parameters of the switched mice to one another and to age-matched mice maintained exclusively on an AL or DR diet from early life (3 months of age) at 1 month, 6 months or 10 months post switch.</p>
<p>Results: Male mice dietary switched from AL-DR in mid life adopted the metabolic phenotype of mice exposed to DR from early life, so by the 10-month timepoint the AL-DR mice overlapped significantly with the DR mice in terms of their metabolic phenotype. Those animals switched from DR-AL in mid life showed clear evidence of a glycemic memory, with significantly improved glucose tolerance relative to mice maintained exclusively on AL feeding from early life. This difference in glucose tolerance was still apparent 10 months after the dietary switch, despite body mass, fasting insulin levels and insulin sensitivity all being similar to AL mice at this time.</p>
<p>Conclusions: Male C57BL/6 mice retain a long-term glycemic memory of early-life DR, in that glucose tolerance is enhanced in mice switched from DR-AL in mid life, relative to AL mice, even 10 months following the dietary switch. These data therefore indicate that the phenotypic benefits of DR are not completely dissipated following a return to AL feeding. The challenge now is to understand the molecular mechanisms underlying these effects, the time course of these effects and whether similar interventions can confer comparable benefits in humans.</p>
Declining uncertainty in transient climate response as CO2 forcing dominates future climate change
Carbon dioxide has exerted the largest portion of radiative forcing and surface temperature change over the industrial era, but other anthropogenic influences have also contributed. However, large uncertainties in total forcing make it difficult to derive climate sensitivity from historical observations. Anthropogenic forcing has increased between the Fourth and Fifth Assessment Reports of the Intergovernmental Panel of Climate Change (IPCC; refs,), although its relative uncertainty has decreased. Here we show, based on data from the two reports, that this evolution towards lower uncertainty can be expected to continue into the future. Because it is easier to reduce air pollution than carbon dioxide emissions and because of the long lifetime of carbon dioxide, the less uncertain carbon dioxide forcing is expected to become increasingly dominant. Using a statistical model, we estimate that the relative uncertainty in anthropogenic forcing of more than 40% quoted in the latest IPCC report for 2011 will be almost halved by 2030, even without better scientific understanding. Absolute forcing uncertainty will also decline for the first time, provided projected decreases in aerosols occur. Other factors being equal, this stronger constraint on forcing will bring a significant reduction in the uncertainty of observation-based estimates of the transient climate response, with a 50% reduction in its uncertainty range expected by 2030
Sensible heat has significantly affected the global hydrological cycle over the historical period
Globally, latent heating associated with a change in precipitation is balanced by changes to atmospheric radiative cooling and sensible heat fluxes. Both components can be altered by climate forcing mechanisms and through climate feedbacks, but the impacts of climate forcing and feedbacks on sensible heat fluxes have received much less attention. Here we show, using a range of climate modelling results, that changes in sensible heat are the dominant contributor to the present global-mean precipitation change since preindustrial time, because the radiative impact of forcings and feedbacks approximately compensate. The model results show a dissimilar influence on sensible heat and precipitation from various drivers of climate change. Due to its strong atmospheric absorption, black carbon is found to influence the sensible heat very differently compared to other aerosols and greenhouse gases. Our results indicate that this is likely caused by differences in the impact on the lower tropospheric stability
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Assessing the Consultation and Relational Empathy (CARE) Measure in sexual health nurses' consultations
Background:
Increasingly healthcare policies emphasise the importance of person-centred, empathic care. Consequently, healthcare professionals are expected to demonstrate the ‘human’ aspects of care in training and in practice. The Consultation and Relational Empathy (CARE) Measure is a patient-rated measure of the interpersonal skills of healthcare practitioners. It has been widely validated for use by healthcare professionals in both primary and secondary care. This paper reports on the validity and reliability of the CARE Measure with sexual health nurses.
Methods:
Patient questionnaires were collected for 943 consultations with 20 sexual health nurses. Participating patients self-completed the questionnaire immediately after the encounter with the nurse. The questionnaire included the ten item CARE Measure, the Patient Enablement Index, and overall satisfaction instruments. Construct validity was assessed through Spearman’s correlation and principal component analysis. Internal consistence was assessed through Cronbach’s alpha and the inter-rater reliability through Generalisability Theory. Data were collected in 2013 in Scotland.
Results:
Female patients completed 68% of the questionnaires. The mean patient age was 28.8 years (standard deviation 9.8 years). Two of the 20 participating nurses withdrew from the study. Most patients (71.7%) regarded the CARE Measure items as very important to their consultation and the number of ‘not applicable’ and missing responses’ were low (2.6% and 0.1% respectively). The participating nurses had high CARE Measure scores; out of a maximum possible score of 50, the overall mean CARE measure score was 47.8 (standard deviation 4.4). The scores were moderately correlated with patient enablement (rho = 0.232, p = 0.001) and overall satisfaction (rho = 0.377, p = 0.001. Cronbach’s alpha showed the measure’s high internal consistency (Cronbach’s alpha coefficient = 0.95), but the inter-rater reliability could not be calculated due to the high achieved CARE Measure scores that varied little between nurses.
Conclusions:
Within this clinical context the CARE Measure has high perceived relevance and face validity. The findings support construct validity and some evidence of reliability. The high CARE Measure scores may have been due to sample bias. A future study which ensures a representative sample of patients on a larger group of nurses is required to determine whether the measure can discriminate between nurses
Greenland ice sheet surface mass loss: recent developments in observation and modeling
Surface processes currently dominate Greenland ice sheet (GrIS) mass loss. We review recent developments in the observation and modelling of GrIS surface mass balance (SMB), published after the July 2012 deadline for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). Since IPCC AR5 our understanding of GrIS SMB has further improved, but new observational and model studies have also revealed that temporal and spatial variability of many processes are still
poorly quantified and understood, e.g. bio-albedo, the formation of ice lenses and their impact on lateral meltwater transport, heterogeneous vertical meltwater transport (‘piping’), the impact of atmospheric circulation changes and mixed-phase clouds on the surface energy balance and the magnitude of turbulent heat exchange over rough ice surfaces. As a result, these processes are only schematically or not at all included in models that are currently used to assess and predict future GrIS surface mass loss
Search for rare quark-annihilation decays, B --> Ds(*) Phi
We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context
of the Standard Model, these decays are expected to be highly suppressed since
they proceed through annihilation of the b and u-bar quarks in the B- meson.
Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected
with the BABAR detector at SLAC. We find no evidence for these decays, and we
set Bayesian 90% confidence level upper limits on the branching fractions BF(B-
--> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results
are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid
Communications
On Component Forces in Physics: A Pragmatic View
Do component forces exist? I argue that the answer lies in the affirmative, on historical and operational grounds
Is the meiofauna a good indicator for climate change and anthropogenic impacts?
Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research
Nurse-Led Medicines' Monitoring for Patients with Dementia in Care Homes: A Pragmatic Cohort Stepped Wedge Cluster Randomised Trial
People with dementia are susceptible to adverse drug reactions (ADRs). However, they are not always closely monitored for potential problems relating to their medicines: structured nurse-led ADR Profiles have the potential to address this care gap. We aimed to assess the number and nature of clinical problems identified and addressed and changes in prescribing following introduction of nurse-led medicines' monitoring.Pragmatic cohort stepped-wedge cluster Randomised Controlled Trial (RCT) of structured nurse-led medicines' monitoring versus usual care.Five UK private sector care homes.41 service users, taking at least one antipsychotic, antidepressant or anti-epileptic medicine.Nurses completed the West Wales ADR (WWADR) Profile for Mental Health Medicines with each participant according to trial step.Problems addressed and changes in medicines prescribed.Information was collected from participants' notes before randomisation and after each of five monthly trial steps. The impact of the Profile on problems found, actions taken and reduction in mental health medicines was explored in multivariate analyses, accounting for data collection step and site.Five of 10 sites and 43 of 49 service users approached participated. Profile administration increased the number of problems addressed from a mean of 6.02 [SD 2.92] to 9.86 [4.48], effect size 3.84, 95% CI 2.57-4.11, P <0.001. For example, pain was more likely to be treated (adjusted Odds Ratio [aOR] 3.84, 1.78-8.30), and more patients attended dentists and opticians (aOR 52.76 [11.80-235.90] and 5.12 [1.45-18.03] respectively). Profile use was associated with reduction in mental health medicines (aOR 4.45, 1.15-17.22).The WWADR Profile for Mental Health Medicines can improve the quality and safety of care, and warrants further investigation as a strategy to mitigate the known adverse effects of prescribed medicines.ISRCTN 48133332
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