Solubility and partitioning of impurities in Be alloys

The most energetically favourable accommodation processes for common impurities and alloying elements in Be metal and Be-Fe-Al intermetallics were investigated using atomic scale simulations. Fe additions, combined with suitable heat treatments, may scavange Al and Si through their incorporation into the FeBe₅ intermetallic. In the absence of Fe, Al and Si will not be associated with Be metal. Li and Mg are also not soluble, but may react with other impurities if present (such as Al or H). Mg may also form the MgBe₁₃ intermetallic phase under certain conditions. He and H exhibit negligible solubility in all phases investigated and whilst He will tend to form bubbles, H can precipitate as BeH₂. Similarly, C additions will form the stable compound Be₂C. Finally, oxygen exhibits a strong affinity to Be, exhibiting both some degree of solubility in all phases considered here (though especially metallic Be) and a highly favourable energy of formation for BeO

Using molecular dynamics to predict the solidus and liquidus of mixed oxides (Th,U)O2, (Th,Pu)O2 and (Pu,U)O2

Molecular dynamics (MD) was used to establish a mechanistic basis for the experimentally observed reduction in liquidus and solidus temperatures below the melting point of the end-members for the mixed oxides (Th, U)O2, (Th, Pu)O2 and (Pu, U)O2. This dip is found at additions of the oxide with higher melting point to the oxide with the lower melting point. There are many causes suggested for the dip; here the distribution of the cation Frenkel energy for the mixed oxides caused by the local environment is proposed as a contributor. Furthermore, a variant of the moving interface method which yields information on the position of the solidus and liquidus boundaries, is used to predict the phase diagrams of these systems

'Man up!': discursive constructions of non-drinkers among UK undergraduates

This study adopted a discursive approach to explore how not drinking alcohol (non-drinking) is construed in relation to masculine identity among 12 undergraduate interviewees. Three prominent discourses were revealed. First, non-drinking was constructed as something strange requiring explanation. Second, contradictory discourses constructed non-drinking as, simultaneously, unsociable yet reflective of greater sociability. Third, non-drinking was constructed as something which has greater negative social consequences for men than for women. Opportunities for challenging traditional gender role expectations are considered

A decision analytical cost analysis of offering ECV in a UK district general hospital

OBJECTIVE: To determine the care pathways and implications of offering mothers the choice of external cephalic version (ECV) at term for singleton babies who present with an uncomplicated breech pregnancy versus assisted breech delivery or elective caesarean. DESIGN: A prospective observational audit to construct a decision analysis of uncomplicated full term breech presentations. SETTING: The North Staffordshire NHS Trust. SUBJECTS: All women (n = 176) who presented at full term with a breech baby without complications during July 1995 and June 1997. MAIN OUTCOME MEASURES: The study determined to compare the outcome in terms of the costs and cost consequences for the care pathways that resulted from whether a women chose to accept the offer of ECV or not. All the associated events were then mapped for the two possible pathways. The costs were considered only within the hospital setting, from the perspective of the health care provider up to the point of delivery. RESULTS: The additional costs for ECV, assisted breech delivery and elective caesarean over and above a normal birth were £186.70, £425.36 and £1,955.22 respectively. The total expected cost of the respective care pathways for "ECV accepted" and "ECV not accepted" (including the probability of adverse events) were £1,452 and £1,828 respectively, that is the cost of delivery through the ECV care pathways is less costly than the non ECV delivery care pathway. CONCLUSIONS: Implementing an ECV service may yield cost savings in secondary care over and above the traditional delivery methods for breech birth of assisted delivery or caesarean section. The scale of these expected cost savings are in the range of £248 to £376 per patient. This converts to a total expected cost saving of between £43,616 and £44,544 for the patient cohort considered in this study

Trans men and friendships: A Foucauldian discourse analysis

While research focusing on friendships of sexual minority individuals has increased over the last two decades, studies of transgender persons’ friendships have been largely absent. Yet, within mainstream literature it has been demonstrated that friendships are central both to identity formation and as support in terms of psychological need and distress. Given that trans people face important identity challenges and may well be disenfranchised within society the role of friendships warrants study. Research which has occurred has largely focussed on trans women, yet trans men face particular issues in terms of their relationships with lesbian women and being positioned as joining patriarchy. This study explored this gap in the literature and used Foucauldian discourse analysis to explore friendship and gender identity. Dominant discourses identified included ‘friends as family’, ‘romance’ and discursive practices of ‘disowning male privilege’, ‘effeminate heterosexual male’ and ‘gender fluidity’ which counter hegemonic (trans) male re-positioning within friendships. The results indicate that trans men elevate the status of friends to those of other culturally dominant relationships (e.g. family or sexual partner). Furthermore, their friendships, in particular friendships with lesbian women, can become complex platforms from which to contest privilege and power associated with their (trans) masculinities. Conceptual and research implications are discussed

Natural images from the birthplace of the human eye

Here we introduce a database of calibrated natural images publicly available through an easy-to-use web interface. Using a Nikon D70 digital SLR camera, we acquired about 5000 six-megapixel images of Okavango Delta of Botswana, a tropical savanna habitat similar to where the human eye is thought to have evolved. Some sequences of images were captured unsystematically while following a baboon troop, while others were designed to vary a single parameter such as aperture, object distance, time of day or position on the horizon. Images are available in the raw RGB format and in grayscale. Images are also available in units relevant to the physiology of human cone photoreceptors, where pixel values represent the expected number of photoisomerizations per second for cones sensitive to long (L), medium (M) and short (S) wavelengths. This database is distributed under a Creative Commons Attribution-Noncommercial Unported license to facilitate research in computer vision, psychophysics of perception, and visual neuroscience.Comment: Submitted to PLoS ON

A comparison of physicians and medical assistants in interpreting verbal autopsy interviews for allocating cause of neonatal death in Matlab, Bangladesh: can medical assistants be considered an alternative to physicians?

Objective. This study assessed the agreement between medical physicians in their interpretation of verbal autopsy (VA) interview data for identifying causes of neonatal deaths in rural Bangladesh. Methods. The study was carried out in Matlab, a rural sub-district in eastern Bangladesh. Trained persons conducted the VA interview with the mother or another family member at the home of the deceased. Three physicians and a medical assistant independently reviewed the VA interviews to assign causes of death using the International Classification of Diseases - Tenth Revision (ICD-10) codes. A physician assigned cause was decided when at least two physicians agreed on a cause of death. Cause-specific mortality fraction (CSMF), kappa (k) statistic, sensitivity, specificity, and positive predictive values were applied to compare agreement between the reviewers.Results. Of the 365 neonatal deaths reviewed, agreement on a direct cause of death was reached by at least two physicians in 339 (93%) of cases. Physician and medical assistant reviews of causes of death demonstrated the following levels of diagnostic agreement for the main causes of deaths: for birth asphyxia the sensitivity was 84%, specificity 93%, and kappa 0.77. For prematurity/low birth weight, the sensitivity, specificity, and kappa statistics were, respectively, 53%, 96%, and 0.55, for sepsis/meningitis they were 48%, 98%, and 0.53, and for pneumonia they were 75%, 94%, and 0.51. Conclusion. This study revealed a moderate to strong agreement between physician- assigned and medical assistant- assigned major causes of neonatal death. A well-trained medical assistant could be considered an alternative for assigning major causes of neonatal deaths in rural Bangladesh and in similar settings where physicians are scarce and their time costs more. A validation study with medically confirmed diagnosis will improve the performance of VA for assigning cause of neonatal death

Levels of State and Trait Anxiety in Patients Referred to Ophthalmology by Primary Care Clinicians: A Cross Sectional Study

Purpose There is a high level of over-referral from primary eye care leading to significant numbers of people without ocular pathology (false positives) being referred to secondary eye care. The present study used a psychometric instrument to determine whether there is a psychological burden on patients due to referral to secondary eye care, and used Rasch analysis to convert the data from an ordinal to an interval scale. Design Cross sectional study. Participants and Controls 322 participants and 80 control participants. Methods State (i.e. current) and trait (i.e. propensity to) anxiety were measured in a group of patients referred to a hospital eye department in the UK and in a control group who have had a sight test but were not referred. Response category analysis plus infit and outfit Rasch statistics and person separation indices were used to determine the usefulness of individual items and the response categories. Principal components analysis was used to determine dimensionality. Main Outcome Measure Levels of state and trait anxiety measured using the State-Trait Anxiety Inventory. Results State anxiety scores were significantly higher in the patients referred to secondary eye care than the controls (p0.1). Rasch analysis highlighted that the questionnaire results needed to be split into “anxiety-absent” and “anxiety-present” items for both state and trait anxiety, but both subscales showed the same profile of results between patients and controls. Conclusions State anxiety was shown to be higher in patients referred to secondary eye care than the controls, and at similar levels to people with moderate to high perceived susceptibility to breast cancer. This suggests that referral from primary to secondary eye care can result in a significant psychological burden on some patients

Aging and Visual Counting

Much previous work on how normal aging affects visual enumeration has been focused on the response time required to enumerate, with unlimited stimulus duration. There is a fundamental question, not yet addressed, of how many visual items the aging visual system can enumerate in a "single glance", without the confounding influence of eye movements.We recruited 104 observers with normal vision across the age span (age 21-85). They were briefly (200 ms) presented with a number of well- separated black dots against a gray background on a monitor screen, and were asked to judge the number of dots. By limiting the stimulus presentation time, we can determine the maximum number of visual items an observer can correctly enumerate at a criterion level of performance (counting threshold, defined as the number of visual items at which ≈63% correct rate on a psychometric curve), without confounding by eye movements. Our findings reveal a 30% decrease in the mean counting threshold of the oldest group (age 61-85: ∼5 dots) when compared with the youngest groups (age 21-40: 7 dots). Surprisingly, despite decreased counting threshold, on average counting accuracy function (defined as the mean number of dots reported for each number tested) is largely unaffected by age, reflecting that the threshold loss can be primarily attributed to increased random errors. We further expanded this interesting finding to show that both young and old adults tend to over-count small numbers, but older observers over-count more.Here we show that age reduces the ability to correctly enumerate in a glance, but the accuracy (veridicality), on average, remains unchanged with advancing age. Control experiments indicate that the degraded performance cannot be explained by optical, retinal or other perceptual factors, but is cortical in origin

A cross-sectional study of the nutritional status of community-dwelling people with idiopathic Parkinson's disease

<p>Abstract</p> <p>Background</p> <p>Parkinson's disease (PD) patients have an increased risk of under-nutrition, but we are unaware of any population based prevalence studies of under-nutrition in PD. The main objective of this study was to identify the prevalence, and nature, of under-nutrition in a representative population of people with PD.</p> <p>Methods</p> <p>People diagnosed with idiopathic PD from within two PD prevalence study sites in North-East England were asked to participate in this study. Those who participated (n = 136) were assessed using a number of standard rating scales including Hoehn & Yahr stage and Unified Parkinson's Disease Rating Scale (UPDRS). Body mass index (BMI), mid-arm circumference (MAC), triceps skin fold thickness (TSF) and grip strength were recorded together with social and demographic information.</p> <p>Results</p> <p>BMI < 20 identified over 15% of the study group to have under-nutrition. The Malnutritional Universal Screening Tool (MUST) scoring system identified 23.5% of participants at medium or high risk of malnutrition. Low BMI, indicating under-nutrition, was associated with greater age and disease duration, lower MAC, TSF, mid-arm muscle circumference (MAMC), reduced grip strength and a report of unintentional weight loss. Problems increased with increasing age and disease duration and were greater in females.</p> <p>Conclusions</p> <p>Under-nutrition is a problem for around 15% of community dwelling people with PD. All PD patients should be screened for under-nutrition; the MUST score is a useful early screening tool.</p