Wall roughness induces asymptotic ultimate turbulence

Turbulence is omnipresent in Nature and technology, governing the transport of heat, mass, and momentum on multiple scales. For real-world applications of wall-bounded turbulence, the underlying surfaces are virtually always rough; yet characterizing and understanding the effects of wall roughness for turbulence remains a challenge, especially for rotating and thermally driven turbulence. By combining extensive experiments and numerical simulations, here, taking as example the paradigmatic Taylor-Couette system (the closed flow between two independently rotating coaxial cylinders), we show how wall roughness greatly enhances the overall transport properties and the corresponding scaling exponents. If only one of the walls is rough, we reveal that the bulk velocity is slaved to the rough side, due to the much stronger coupling to that wall by the detaching flow structures. If both walls are rough, the viscosity dependence is thoroughly eliminated in the boundary layers and we thus achieve asymptotic ultimate turbulence, i.e. the upper limit of transport, whose existence had been predicted by Robert Kraichnan in 1962 (Phys. Fluids {\bf 5}, 1374 (1962)) and in which the scalings laws can be extrapolated to arbitrarily large Reynolds numbers

Extracellular Hsp72 concentration relates to a minimum endogenous criteria during acute exercise-heat exposure

Extracellular heat-shock protein 72 (eHsp72) concentration increases during exercise-heat stress when conditions elicit physiological strain. Differences in severity of environmental and exercise stimuli have elicited varied response to stress. The present study aimed to quantify the extent of increased eHsp72 with increased exogenous heat stress, and determine related endogenous markers of strain in an exercise-heat model. Ten males cycled for 90 min at 50% O2peak in three conditions (TEMP, 20°C/63% RH; HOT, 30.2°C/51%RH; VHOT, 40.0°C/37%RH). Plasma was analysed for eHsp72 pre, immediately post and 24-h post each trial utilising a commercially available ELISA. Increased eHsp72 concentration was observed post VHOT trial (+172.4%) (P<0.05), but not TEMP (-1.9%) or HOT (+25.7%) conditions. eHsp72 returned to baseline values within 24hrs in all conditions. Changes were observed in rectal temperature (Trec), rate of Trec increase, area under the curve for Trec of 38.5°C and 39.0°C, duration Trec ≥ 38.5°C and ≥ 39.0°C, and change in muscle temperature, between VHOT, and TEMP and HOT, but not between TEMP and HOT. Each condition also elicited significantly increasing physiological strain, described by sweat rate, heart rate, physiological strain index, rating of perceived exertion and thermal sensation. Stepwise multiple regression reported rate of Trec increase and change in Trec to be predictors of increased eHsp72 concentration. Data suggests eHsp72 concentration increases once systemic temperature and sympathetic activity exceeds a minimum endogenous criteria elicited during VHOT conditions and is likely to be modulated by large, rapid changes in core temperature

Psychometric Properties of an Assessment for Mental Health Recovery Programs

The concept of recovery can be operationalized from either the point of view of the consumer, or from the perspective of the agency providing services. The Milestones of Recovery Scale (MORS) was created to capture aspects of recovery from the agency perspective. Evidence establishing the psychometric properties of the MORS was obtained in three efforts: Inter-rater reliability using staff at The Village, a multi-service organization serving the homeless mentally ill in Long Beach, California; inter-rater reliability was also obtained from Vinfen Corporation, a large provider of housing services to mentally ill persons in Boston, Massachusetts. A test–retest reliability study was conducted using staff rating of clients at The Village, and evidence for validity was obtained using the Level of Care Utilization System (LOCUS) as a validity measure. The intra-class correlation coefficient for the inter-rater reliability study was r = .85 (CI .81, .89) for The Village and r = .86 (CI .80, .90) for Vinfen Corporation; test–retest reliability was r = .85 (CI .81, .87); and validity coefficients for the LOCUS were at or above r = .49 for all subscales except one. There is sufficient evidence for the reliability and validity of the MORS

“Fracture” phenomena in shearing flow of viscous liquids

In start-up of steady shearing flow of two viscous unentangled liquids, namely low-molecular-weight polystyrene and α-D-glucose, the shear stress catastrophically collapses if the shear rate is raised above a value corresponding to a critical initial shear stress of around 0.1–0.3 MPa. The time dependence of the shear stress during this process is similar for the two liquids, but visualization of samples in situ and after quenching reveals significant differences. For α-D-glucose, the stress collapse evidently results from debonding of the sample from the rheometer tool, while in polystyrene, bubbles open up within the sample, as occurs in cavitation. Some similarities are pointed out between these phenomena and that of “lubrication failure” reported in the tribology literature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47212/1/397_2004_Article_BF00368135.pd

X-Ray Spectroscopy of Stars

(abridged) Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Low-mass stars on the cooler part of the main sequence and their pre-main sequence predecessors define the dominant stellar population in the galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense, of X-ray spectra from the solar corona. X-ray emission from cool stars is indeed ascribed to magnetically trapped hot gas analogous to the solar coronal plasma. Coronal structure, its thermal stratification and geometric extent can be interpreted based on various spectral diagnostics. New features have been identified in pre-main sequence stars; some of these may be related to accretion shocks on the stellar surface, fluorescence on circumstellar disks due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot stars clearly dominate the interaction with the galactic interstellar medium: they are the main sources of ionizing radiation, mechanical energy and chemical enrichment in galaxies. High-energy emission permits to probe some of the most important processes at work in these stars, and put constraints on their most peculiar feature: the stellar wind. Here, we review recent advances in our understanding of cool and hot stars through the study of X-ray spectra, in particular high-resolution spectra now available from XMM-Newton and Chandra. We address issues related to coronal structure, flares, the composition of coronal plasma, X-ray production in accretion streams and outflows, X-rays from single OB-type stars, massive binaries, magnetic hot objects and evolved WR stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures (partly multiple); some corrections made after proof stag

Efficacy of exposure versus cognitive therapy in anxiety disorders: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>There is growing evidence of the effectiveness of Cognitive Behavioural Therapy (CBT) for a wide range of psychological disorders. There is a continued controversy about whether challenging maladaptive thoughts rather than use of behavioural interventions alone is associated with the greatest efficacy. However little is known about the relative efficacy of various components of CBT. This review aims to compare the relative efficacy of Cognitive Therapy (CT) versus Exposure (E) for a range of anxiety disorders using the most clinically relevant outcome measures and estimating the summary relative efficacy by combining the studies in a meta-analysis.</p> <p>Methods</p> <p>Psych INFO, MEDLINE and EMBASE were searched from the first available year to May 2010. All randomised controlled studies comparing the efficacy of exposure with cognitive therapy were included. Odds ratios (OR) or standardised means' differences (Hedges' g) for the most clinically relevant primary outcomes were calculated. Outcomes of the studies were grouped according to specific disorders and were combined in meta-analyses exploring short-term and long-term outcomes.</p> <p>Results</p> <p>20 Randomised Controlled Trials with (n = 1,308) directly comparing the efficacy of CT and E in anxiety disorders were included in the meta-analysis. No statistically significant difference in the relative efficacy of CT and E was revealed in Post Traumatic Stress Disorder (PTSD), in Obsessive Compulsive Disorder (OCD) and in Panic Disorder (PD). There was a statistically significant difference favouring CT versus E in Social Phobia both in the short-term (Z = 3.72, p = 0.0002) and the long-term (Z = 3.28, p = 0.001) outcomes.</p> <p>Conclusions</p> <p>On the basis of extant literature, there appears to be no evidence of differential efficacy between cognitive therapy and exposure in PD, PTSD and OCD and strong evidence of superior efficacy of cognitive therapy in social phobia</p

Beyond climate envelopes: effects of weather on regional population trends in butterflies

Although the effects of climate change on biodiversity are increasingly evident by the shifts in species ranges across taxonomical groups, the underlying mechanisms affecting individual species are still poorly understood. The power of climate envelopes to predict future ranges has been seriously questioned in recent studies. Amongst others, an improved understanding of the effects of current weather on population trends is required. We analysed the relation between butterfly abundance and the weather experienced during the life cycle for successive years using data collected within the framework of the Dutch Butterfly Monitoring Scheme for 40 species over a 15-year period and corresponding climate data. Both average and extreme temperature and precipitation events were identified, and multiple regression was applied to explain annual changes in population indices. Significant weather effects were obtained for 39 species, with the most frequent effects associated with temperature. However, positive density-dependence suggested climatic independent trends in at least 12 species. Validation of the short-term predictions revealed a good potential for climate-based predictions of population trends in 20 species. Nevertheless, data from the warm and dry year of 2003 indicate that negative effects of climatic extremes are generally underestimated for habitat specialists in drought-susceptible habitats, whereas generalists remain unaffected. Further climatic warming is expected to influence the trends of 13 species, leading to an improvement for nine species, but a continued decline in the majority of species. Expectations from climate envelope models overestimate the positive effects of climate change in northwestern Europe. Our results underline the challenge to include population trends in predicting range shifts in response to climate change

Peer Support Workers in Health:A Qualitative Metasynthesis of Their Experiences

Peer support models, where an individual has a specific illness or lifestyle experience and supports others experiencing similar challenges, have frequently been used in different fields of healthcare to successfully engage hard-to-reach groups. Despite recognition of their value, the impact of these roles on the peer has not been systematically assessed. By synthesising the qualitative literature we sought to review such an impact, providing a foundation for designing future clinical peer models.Systematic review and qualitative metasynthesis of studies found in Medline, CINAHL or Scopus documenting peer worker experiences.1,528 papers were found, with 34 meeting the criteria of this study. Findings were synthesised to reveal core constructs of reframing identity through reciprocal relations and the therapeutic use of self, enhancing responsibility.The ability of the Peer Support Worker to actively engage with other marginalised or excluded individuals based on their unique insight into their own experience supports a therapeutic model of care based on appropriately sharing their story. Our findings have key implications for maximising the effectiveness of Peer Support Workers and in contributing their perspective to the development of a therapeutic model of care