806 research outputs found

    Numerical Optimization of the Thermal Field in Bridgman Detached Growth

    Get PDF
    The global modeling of the thermal field in two vertical Bridgman-like crystal growth configurations, has been performed to get optimal thermal conditions for a successful detached growth of Ge and CdTe crystals. These computations are performed using the CrysMAS code and expand upon our previous analysis [1] that propose a new mechanism involving the thermal field and meniscus position to explain stable conditions for dewetted Bridgman growth. The analysis of the vertical Bridgman configuration with two heaters, used by Palosz et al. for the detached growth of Ge, shows, consistent with their results, that the large wetting angle of germanium on boron nitride surfaces was an important factor to promote a successful detached growth. Our computations predict that by initiating growth much higher into the hot zone of the furnace, the thermal conditions will be favorable for continued detachment even for systems that did not exhibit high contact angles. The computations performed for a vertical gradient freeze configuration with three heaters representative of that used for the detached growth of CdTe, show favorable thermal conditions for dewetting during the entirely growth run described. Improved thermal conditions are also predicted for coated silica crucibles when the solid-liquid interface advances higher into the hot zone during the solidification process. The second set of experiments on CdTe growth described elsewhere has shown the reattachment of the crystal to the crucible after few centimeters of dewetted growth. The thermal modeling of this configuration shows a second solidification front appearing at the top of the sample and approaching the middle line across the third heater. In these conditions, the crystal grows detached from the bottom, but will be attached to the crucible in the upper part because of the solidification without gap in this region. The solidification with two interfaces can be avoided when the top of the sample is positioned below the middle position of the third furnace

    The Relationship Between Cumulative Unfair Treatment and Intima Media Thickness and Adventitial Diameter: The Moderating Role of Race in The Study of Women’s Health Across the Nation

    Get PDF
    Objective: Unfair treatment may have a detrimental effect on cardiovascular health. However, little research on chronic health outcomes employs cumulative measures of unfair treatment. We tested whether cumulative unfair treatment was associated with greater subclinical cardiovascular disease in a diverse sample of African American, Caucasian, Chinese, and Hispanic women. We also examined whether this relationship varied by race. Method: The Study of Women’s Health Across the Nation is a longitudinal study of midlife women. Cumulative unfair treatment was calculated as the average of unfair treatment assessed over 10 years at 6 time points. Subclinical cardiovascular disease, specifically carotid intima media thickness and adventitial diameter, was assessed via carotid ultrasound conducted at study year 12 in 1056 women. We tested whether cumulative unfair treatment was related to subclinical cardiovascular disease via linear regression, controlling for demographic factors including socioeconomic status and cardiovascular risk factors. Results: The relation between unfair treatment and subclinical cardiovascular disease significantly varied by race (ps \u3c .05), with unfair treatment related to higher intima media thickness (B = .03, SE = .01, p = .009) and adventitial diameter (B = .02, SE = .009, p = .013) among Caucasian women only. No significant relations between unfair treatment and subclinical cardiovascular disease outcomes were observed for African American, Hispanic, and Chinese women. Conclusions: Our findings indicate that cumulative unfair treatment is related to worse subclinical cardiovascular disease among Caucasian women. These findings add to the growing literature showing that Caucasian women’s experience of unfair treatment may have detrimental health implications

    The Relationship Between Cumulative Unfair Treatment and Intima Media Thickness and Adventitial Diameter: The Moderating Role of Race in The Study of Women’s Health Across the Nation

    Get PDF
    Objective: Unfair treatment may have a detrimental effect on cardiovascular health. However, little research on chronic health outcomes employs cumulative measures of unfair treatment. We tested whether cumulative unfair treatment was associated with greater subclinical cardiovascular disease in a diverse sample of African American, Caucasian, Chinese, and Hispanic women. We also examined whether this relationship varied by race. Method: The Study of Women’s Health Across the Nation is a longitudinal study of midlife women. Cumulative unfair treatment was calculated as the average of unfair treatment assessed over 10 years at 6 time points. Subclinical cardiovascular disease, specifically carotid intima media thickness and adventitial diameter, was assessed via carotid ultrasound conducted at study year 12 in 1056 women. We tested whether cumulative unfair treatment was related to subclinical cardiovascular disease via linear regression, controlling for demographic factors including socioeconomic status and cardiovascular risk factors. Results: The relation between unfair treatment and subclinical cardiovascular disease significantly varied by race (ps \u3c .05), with unfair treatment related to higher intima media thickness (B = .03, SE = .01, p = .009) and adventitial diameter (B = .02, SE = .009, p = .013) among Caucasian women only. No significant relations between unfair treatment and subclinical cardiovascular disease outcomes were observed for African American, Hispanic, and Chinese women. Conclusions: Our findings indicate that cumulative unfair treatment is related to worse subclinical cardiovascular disease among Caucasian women. These findings add to the growing literature showing that Caucasian women’s experience of unfair treatment may have detrimental health implications

    Application of Newtonian physics to predict the speed of a gravity racer

    Get PDF
    Gravity racing can be studied using numerical solutions to the equations of motion derived from Newton’s second law. This allows students to explore the physics of gravity racing and to understand how design and course selection influences vehicle speed. Using Euler’s method, we have developed a spreadsheet application that can be used to predict the speed of a gravity powered vehicle. The application includes the effects of air and rolling resistance. Examples of the use of the application for designing a gravity racer are presented and discussed. Predicted speeds are compared to the results of an official world record attempt

    Mammalian GRIP domain proteins differ in their membrane binding properties and are recruited to distinct domains of the TGN

    Get PDF
    The four mammalian golgins, p230/golgin-245, golgin-97, GCC88 and GCC185 are targeted to trans-Golgi network ITGN) membranes by their C-terminal GRIP domain in a G-protein-dependent process. The Arf-like GTPase, Arl1, has been shown to mediate TGN recruitment of p230/golgin245 and golgin-97 by interaction with their GRIP domains; however, it is not known whether all the TGN golgins bind to Arl1 and whether they are all recruited to the same or different TGN domains. Here we demonstrate differences in membrane binding properties and TGN domain recruitment of the mammalian GRIP domain proteins. Overexpression of full-length GCC185 resulted in the appearance of small punctate structures dispersed in the cytoplasm of transfected cells that were identified as membrane tubular structures by immunoelectron microscopy. The cytoplasmic GCC185-labelled structures were enriched for membrane binding determinants of GCC185 GRIP, whereas the three other mammalian GRIP family members did not colocalize with the GCC185-labelled structures. These GCC185-labelled structures included the TGN resident protein alpha2,6 sialyltransferase and excluded the recycling TGN protein, TGN46. The Golgi stack was unaffected by overexpression of GCC185. Overexpression of both full-length GCC185 and GCC88 showed distinct and nonoverlapping structures. We also show that the GRIP domains of GCC185 and GCC88 differ in membrane binding properties from each other and, in contrast to p230/golgin245 and golgin-97, do not interact with Arl1 in vivo. Collectively these results show that GCC88, GCC185 and p230/golgin245 are recruited to functionally distinct domains of the TGN and are likely to be important for the maintenance of TGN subdomain structure, a critical feature for mediating protein sorting and membrane transport

    Low Levels of Fruit Nitrogen as Drivers for the Evolution of Madagascar's Primate Communities

    Get PDF
    The uneven representation of frugivorous mammals and birds across tropical regions - high in the New World, low in Madagascar and intermediate in Africa and Asia - represents a long-standing enigma in ecology. Several hypotheses have been proposed to explain these differences but the ultimate drivers remain unclear. Here, we tested the hypothesis that fruits in Madagascar contain insufficient nitrogen to meet primate metabolic requirements, thus constraining the evolution of frugivory. We performed a global analysis of nitrogen in fruits consumed by primates, as collated from 79 studies. Our results showed that average frugivory among lemur communities was lower compared to New World and Asian-African primate communities. Fruits in Madagascar contain lower average nitrogen than those in the New World and Old World. Nitrogen content in the overall diets of primate species did not differ significantly between major taxonomic radiations. There is no relationship between fruit protein and the degree of frugivory among primates either globally or within regions, with the exception of Madagascar. This suggests that low protein availability in fruits influences current lemur communities to select for protein from other sources, whereas in the New World and Old World other factors are more significant in shaping primate communities

    An open-label, 1-year extension study of the long-term safety and efficacy of once-daily OROS® hydromorphone in patients with chronic cancer pain

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Opioid analgesics have proven efficacy in the short-term management of chronic cancer pain, but data on their long-term use is more limited. OROS<sup>® </sup>hydromorphone is a controlled-release formulation of oral hydromorphone that may be particularly well suited to long-term management of chronic cancer pain because it provides stable plasma concentrations and consistent analgesia with convenient once-daily dosing. The objective of this study (DO-118X) was to characterise the pain control achieved with long-term repeated dosing of OROS<sup>® </sup>hydromorphone in patients with chronic cancer pain.</p> <p>Methods</p> <p>In this multicentre, phase III, open-label, single treatment, 1-year extension study, OROS<sup>® </sup>hydromorphone was administered to 68 patients with moderate-to-severe chronic cancer pain, who had successfully completed a short-term equivalence study, and whose pain was controlled with a stable dose of medication (≥ 8 mg OROS<sup>® </sup>hydromorphone or equivalent controlled-release morphine). Patients were started on the dose of OROS<sup>® </sup>hydromorphone equivalent to the opioid dose on which they achieved dose-stable pain control in the equivalence study; dose adjustments were made as necessary and breakthrough pain medication was permitted. Efficacy was assessed with the Brief Pain Inventory (BPI) and patient and investigator global evaluations of treatment effectiveness. No formal statistical analysis was done.</p> <p>Results</p> <p>The mean (standard deviation) duration of exposure to study medication was 139 (129.9) days and the mean (standard deviation) average daily consumption of OROS<sup>® </sup>hydromorphone was 43.7 (28.14) mg/day. All scores were maintained at a mild to moderate severity throughout the study; however, BPI scores for pain at its worst, pain at its least, pain on average, pain right now, and pain relief were slightly worsened at end point compared with baseline. Mean BPI pain interference with daily activities and patient and investigator global evaluation scores also remained generally stable. Treatment effectiveness was rated as fair to good throughout the study. The most frequently reported adverse events were nausea (n = 24, 35.3%), constipation (n = 22, 32.4%), and vomiting (n = 15, 22.1%).</p> <p>Conclusion</p> <p>The results of this extension study suggest that long-term repeated dosing with once-daily OROS<sup>® </sup>hydromorphone can be beneficial in the continuing management of persistent, moderate-to-severe cancer pain.</p

    Predictors of long-term pain and disability in patients with low back pain investigated by magnetic resonance imaging: A longitudinal study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>It is possible that clinical outcome of low back pain (LBP) differs according to the presence or absence of spinal abnormalities on magnetic resonance imaging (MRI), in which case there could be value in using MRI findings to refine case definition of LBP in epidemiological research. We therefore conducted a longitudinal study to explore whether spinal abnormalities on MRI for LBP predict prognosis after 18 months.</p> <p>Methods</p> <p>A consecutive series of patients aged 20-64 years, who were investigated by MRI because of mechanical LBP (median duration of current episode 16.2 months), were identified from three radiology departments, and those who agreed completed self-administered questionnaires at baseline and after a mean follow-up period of 18.5 months (a mean of 22.2 months from MRI investigation). MRI scans were assessed blind to other clinical information, according to a standardised protocol. Associations of baseline MRI findings with pain and disability at follow-up, adjusted for treatment and for other potentially confounding variables, were assessed by Poisson regression and summarised by prevalence ratios (PRs) with their 95% confidence intervals (CIs).</p> <p>Results</p> <p>Questionnaires were completed by 240 (74%) of the patients who had agreed to be followed up. Among these 111 men and 129 women, 175 (73%) reported LBP in the past four weeks, 89 (37%) frequent LBP, and 72 (30%) disabling LBP. In patients with initial disc degeneration there was an increased risk of frequent (PR 1.3, 95%CI 1.0-1.9) and disabling LBP (PR 1.7, 95%CI 1.1-2.5) at follow-up. No other associations were found between MRI abnormalities and subsequent outcome.</p> <p>Conclusions</p> <p>Our findings suggest that the MRI abnormalities examined are not major predictors of outcome in patients with LBP. They give no support to the use of MRI findings as a way of refining case definition for LBP in epidemiological research.</p
    corecore