388 research outputs found

    Fine sediment reduces vertical migrations of Gammarus pulex (Crustacea: Amphipoda) in response to surface water loss

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    Surface and subsurface sediments in river ecosystems are recognized as refuges that may promote invertebrate survival during disturbances such as floods and streambed drying. Refuge use is spatiotemporally variable, with environmental factors including substrate composition, in particular the proportion of fine sediment (FS), affecting the ability of organisms to move through interstitial spaces. We conducted a laboratory experiment to examine the effects of FS on the movement of Gammarus pulex Linnaeus (Crustacea: Amphipoda) into subsurface sediments in response to surface water loss. We hypothesized that increasing volumes of FS would impede and ultimately prevent individuals from migrating into the sediments. To test this hypothesis, the proportion of FS (1–2 mm diameter) present within an open gravel matrix (4–16 mm diameter) was varied from 10 to 20% by volume in 2.5% increments. Under control conditions (0% FS), 93% of individuals moved into subsurface sediments as the water level was reduced. The proportion of individuals moving into the subsurface decreased to 74% at 10% FS, and at 20% FS no individuals entered the sediments, supporting our hypothesis. These results demonstrate the importance of reducing FS inputs into river ecosystems and restoring FS-clogged riverbeds, to promote refuge use during increasingly common instream disturbances

    Internal Medicine Residents Reject “Longer and Gentler” Training

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    BACKGROUND: Increasing complexity of medical care, coupled with limits on resident work hours, has prompted consideration of extending Internal Medicine training. It is unclear whether further hour reductions and extension of training beyond the current duration of 3 years would be accepted by trainees. OBJECTIVE: We aimed to determine if further work-hour reductions and extension of training would be accepted by trainees and whether resident burnout affects their opinions. DESIGN: A postal survey was sent to all 143 Internal Medicine residents at the University of Colorado School of Medicine in May 2004. MEASUREMENTS: The survey contained questions related to opinions on work-hour limits using a 5-point Likert scale ranging from strongly agree to strongly disagree. Burnout was measured using the Maslach Burnout Inventory, organized into three subscales: emotional exhaustion (EE), depersonalization (DP), and personal accomplishment, with burnout defined as high EE or DP. RESULTS: Seventy-four percent (106/143) of residents returned the survey. The vast majority (84%) of residents disagreed or strongly disagreed with extending training to 4 or 5 years. Burnout residents were less averse to extending training (strongly agree or agree, 18.9% vs 4.3%, P = .04). The majority of residents (68.9%) disagreed or strongly disagreed with establishing a 60-hour/week limit. Residents who met the criteria for burnout were more likely to agree that a 60-hour limit would be better than an 80-hour limit (strongly agree or agree, 22% vs 8%, P = .02). CONCLUSIONS: In this program, most Internal Medicine residents are strongly opposed to extending their training to 4 or 5 years and would prefer the current 80 hours/week cap. A longer, less intense pace of Internal Medicine training seems to be less attractive in the eyes of current trainees

    Colouration and Colour Changes of the Fiddler Crab, Uca capricornis: A Descriptive Study

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    Colour changes in animals may be triggered by a variety of social and environmental factors and may occur over a matter of seconds or months. Crustaceans, like fiddler crabs (genus Uca), are particularly adept at changing their colour and have been the focus of numerous studies. However, few of these studies have attempted to quantitatively describe the individual variation in colour and pattern or their adaptive significance. This paper quantitatively describes the colour patterns of the fiddler crab Uca capricornis and their ability to change on a socially significant timescale. The most dramatic changes in colour pattern are associated with moulting. These ontogenetic changes result in a general reduction of the colour pattern with increasing size, although females are more colourful and variable than similarly-sized males. Uca capricornis are also capable of rapid colour changes in response to stress, but show no endogenous rhythms associated with the semilunar and tidal cycles commonly reported in other fiddler crabs. The extreme colour polymorphism and the relative stability of the colour patterns in Uca capricornis are consistent with their use in visually mediated mate recognition

    Embodying limb absence in the negotiation of sexual intimacy

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    Some people with physical disabilities experience difficulties in forming and maintaining intimate and sexual relationships (Taleporos and McCabe, 2001). Individuals with physical impairments may variously be seen as inferior, ‘not up to scratch’ and can be less valued than those thought to embody the cultural ideal of ‘normality’ (Edwards and Imrie, 2003). The loss of an anatomical part such as an arm or a leg can therefore set up a complex series of perceptual, emotional and psychological responses that can limit or prevent individuals from fully experiencing the kinds of intimate relationships that many of their ‘non-disabled’ counterparts can more freely enjoy (Oliver, 1990). Drawing on a series of semi-structured interviews and a group visual workshop with five men and two women with varying acquired and congenital limb absences, this study explores the variety of ways in which sexual relationships and intimacies are negotiated and managed. Certain participants reported a great deal of anxiety regarding their perceptions of sexual attractiveness, and experienced feelings of loss of desirability as a sexual partner. Others reported engaging in an ‘active management of visual information’ about the body, through methods of concealment and exposure. Compensatory strategies were also reported as a way to effectively maintain existing intimate relationships. Finally, hyper-masculine or hyper-feminine enactments of sexuality were described within a range of social and intimate contexts as a means to ‘normalise’ the disabled body. The findings of this study provide a richer and more contextualised understanding of the highly complex adjustment process faced by individuals with limb absence, who actively engage in sexual and intimate relationships

    A review of elliptical and disc galaxy structure, and modern scaling laws

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    A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

    High-normal blood glucose levels may be associated with decreased spatial perception in young healthy adults.

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    The negative effects of high normal glucose on cognitive function were previously reported in euglycemic individuals of middle age and the elderly population. This study aimed at examining the effect of baseline blood glucose levels on spatial ability, specifically verticality perception on the computerized rod and frame test (CRFT) in young healthy adults. 63 healthy male medical students (age range from 18-23 years), of whom 30 were non-fasting outside the month of Ramadan and 33 fasting during Ramadan of the year 2016, were recruited in order to create varying degrees of glycemia during which verticality perception was carried out. Baseline blood glucose reading was obtained prior to commencing the CRFT test. Blood glucose levels at the time of testing decreased as the duration between the last meal and testing increased. A blood glucose range of 62-117 mg/dl was achieved among participants for this study. Linear regression analysis showed that blood glucose level at testing correlated positively with all alignment spatial error parameters, indicating a probable reduction of spatial perception ability with higher blood glucose levels. These results are consistent with other cognitive studies in older healthy humans and emphasize the critical impact of early glucose dys-homeostasis on cognitive function. They also indicate that elevated blood glucose may affect cognitive functioning outside of the usual complications of diabetes

    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

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    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

    A Probiotic Adjuvant Lactobacillus rhamnosus Enhances Specific Immune Responses after Ocular Mucosal Immunization with Chlamydial Polymorphic Membrane Protein C

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    Recent advances in the development of chlamydia vaccines, using live-attenuated or ultraviolet light-inactivated chlamydia, are paving the way for new possibilities to oppose the societal challenges posed by chlamydia-related diseases, such as blinding trachoma. An effective subunit vaccine would mitigate the risks associated with the use of a whole-cell vaccine. Our rationale for the design of an efficient subunit vaccine against Chlamydia trachomatis (Ct) is based on the membrane proteins involved in the initial Ct-host cell contact and on the route of immunization that mimics the natural infection process (i.e., via the ocular mucosa). The first aim of our study was to characterize the specific conjunctival and vaginal immune responses following eye drop immunization in BALB/c mice, using the N-terminal portion of the Ct serovar E polymorphic membrane protein C (N-PmpC) as the subunit vaccine antigen. Second, we aimed to examine the adjuvant properties of the probiotic Lactobacillus rhamnosus (LB) when formulated with N-PmpC. N-PmpC applied alone stimulated the production of N-PmpC-and Ct serovar B-specific antibodies in serum, tears and vaginal washes, whereas the combination with LB significantly enhanced these responses. The N-PmpC/LB combination initiated a T cell response characterized by an elevated percentage of CD25+ T cells and CD8+ effector T cells, enhanced CD4+ T-helper 1 skewing, and increased regulatory T cell responses. Together, these results show that eye drop vaccination with combined use of N-PmpC and a live probiotic LB stimulates specific cellular and humoral immune responses, not only locally in the conjunctiva but also in the vaginal mucosa, which could be a promising approach in Ct vaccine development

    Risk factors for hospitalization among adults with asthma: the influence of sociodemographic factors and asthma severity

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    BACKGROUND: The morbidity and mortality from asthma have markedly increased since the late 1970s. The hospitalization rate, an important marker of asthma severity, remains substantial. METHODS: In adults with health care access, we prospectively studied 242 with asthma, aged 18–50 years, recruited from a random sample of allergy and pulmonary physician practices in Northern California to identify risk factors for subsequent hospitalization. RESULTS: Thirty-nine subjects (16%) reported hospitalization for asthma during the 18-month follow-up period. On controlling for asthma severity in multiple logistic regression analysis, non-white race (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.1–8.8) and lower income (OR, 1.1 per 10,000decrement;9510,000 decrement; 95% CI, 0.9–1.3) were associated with a higher risk of asthma hospitalization. The severity-of-asthma score (OR, 3.4 per 5 points; 95%, CI 1.7–6.8) and recent asthma hospitalization (OR, 8.3; 95%, CI, 2.1–33.4) were also related to higher risk, after adjusting for demographic characteristics. Reliance on emergency department services for urgent asthma care was also associated with a greater likelihood of hospitalization (OR, 3.2; 95% CI, 1.0–9.8). In multivariate analysis not controlling for asthma severity, low income was even more strongly related to hospitalization (OR, 1.2 per 10,000 decrement; 95% CI, 1.02–1.4). CONCLUSION: In adult asthmatics with access to health care, non-white race, low income, and greater asthma severity were associated with a higher risk of hospitalization. Targeted interventions applied to high-risk asthma patients may reduce asthma morbidity and mortality

    Expression and prognostic value of circulating angiogenic cytokines in pancreatic cancer

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    <p>Abstract</p> <p>Background</p> <p>The utility of circulating angiogenic cytokines (CAC) as biomarkers in pancreatic cancer has not been clarified yet. We investigated the expression and prognostic associations of seven CAC in patients with pancreatic cancer.</p> <p>Methods</p> <p>Serum samples were collected preoperatively in patients undergoing surgery for localized pancreatic cancer (n = 74), metastatic pancreatic cancer (n = 24) or chronic pancreatitis (n = 20) and in healthy controls (n = 48). Quantitative enzyme-linked immunosorbent assays and multiplex protein arrays were used to determine circulating levels of VEGF, VEGFR-1, PlGF, PDGF-AA, PDGF-BB, Ang-1 and EGF. Multivariate analyses on cancer-specific survival were performed with a Cox proportional hazards model.</p> <p>Results</p> <p>VEGF (p < 0.0001), PDGF-AA (p < 0.0001), Ang-1 (p = 0.002) and EGF (p < 0.0001) were differentially expressed in patients with pancreatic cancer compared to healthy controls. The presence of lymph node metastases was associated with increased levels of all CAC except for PlGF, whereas there were only minor associations of CAC with other clinicopathologic variables. The multivariate model including the entire angiogenic panel revealed high levels of circulating PDGF-AA (hazard ratio 4.58; 95% confidence interval 1.43 - 14.69) as predictor of poor cancer-specific survival, whereas high levels of PDGF-BB (0.15; 0.15 - 0.88), Ang-1 (0.30; 0.10 - 0.93) and VEGF (0.24; 0.09 - 0.57) were associated with a favorable prognosis.</p> <p>Conclusion</p> <p>Circulating levels of certain angiogenic cytokines correlate with patients' prognosis after resection for pancreatic cancer, if a panel of several CAC is considered simultaneously. These data should be considered in future studies evaluating angiogenic factors as prognostic biomarkers and therapeutic targets in patients with pancreatic cancer.</p
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