81 research outputs found
CO2 content beneath northern Iceland and the variability of mantle carbon
Primitive basalt melt inclusions from Borgarhraun, northern Iceland, display large correlated variations in CO2 and nonvolatile incompatible trace elements (ITEs) such as Nb, Th, Rb, and Ba. The average CO2/ITE ratios of the Borgarhraun melt inclusion population are precisely determined (e.g., CO2/Nb = 391 ± 16; 2σM [two standard errors of the mean], n = 161). These data, along with published data on five other populations of undegassed mid-oceanic ridge basalt (MORB) glasses and melt inclusions, demonstrate that upper mantle CO2/Ba and CO2/Rb are nearly homogeneous, while CO2/Nb and CO2/Th are broadly correlated with long-term indices of mantle heterogeneity reflected in Nd isotopes (143Nd/144Nd) in five of the six regions of the upper mantle examined thus far. Our results suggest that heterogeneous carbon contents of the upper mantle are long-lived features, and that average carbon abundances of the mantle sources of Atlantic MORB are higher by a factor of two than those of Pacific MORB. This observation is correlated with a similar distinction in water contents and trace elements characteristic of subduction fluids (Ba, Rb). We suggest that the upper mantle beneath the younger Atlantic Ocean basin contains components of hydrated and carbonated subduction-modified mantle from prior episodes of Iapetus subduction that were entrained and mixed into the upper mantle during opening of the Atlantic Ocean basin
Heat capacity and thermodynamic properties of FeSb2 from 5 to 1021.2 K Enthalpy of decomposition
The heat capacity of FeSb2 has been measured by adiabatic-shield calorimetry from 5 to 1021.2 K. At the latter temperature the phase decomposes into the FeSb phase and an antimony-rich melt. The heat capacity increases regularly over the entire temperature range, except for a high value at 898 K which is related to the fusion of a small amount of antimony. The enthalpy of peritectic decomposition of FeSb2 at 1021.2 K is (12910 +/- 30) calth mol-1. Thermodynamic functions have been evaluated and the values of Cp, {So(T) - So(0)}, and -[{Go(T) - Ho(0)}/T] at 298.15 and 1000 K are 19.08, 25.98, 12.881, and 24.80, 51.01, and 32.25 calth K-1 mol-1, respectively. The present results together with the Gibbs free energy of formation values from the literature give the formation values:Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23070/1/0000644.pd
Control of infective larvae of gastrointestinal nematodes in heifers using different isolates of nematophagous fungi
Current state of quality of life and patient-reported outcomes research
The 5th EORTC Quality of Life in Cancer Clinical Trials Conference presented the current state of quality of life and other patient-reported outcomes (PROs) research from the perspectives of researchers, regulators, industry representatives, patients and patient advocates and health care professionals. A major theme was the assessment of the burden of cancer treatments, and this was discussed in terms of regulatory challenges in using PRO assessments in clinical trials, patients' experiences in cancer clinical trials, innovative methods and standardisation in cancer research, innovative methods across the disease sites or populations and cancer survivorship. Conferees demonstrated that PROs are becoming more accepted and major efforts are ongoing internationally to standardise PROs measurement, analysis and reporting in trials. Regulators are keen to collaborate with all stakeholders to ensure that the right questions are asked and the right answers are communicated. Improved technology and increased flexibility of measurement instruments are making PROs data more robust. Patients are being encouraged to be patient partners. International collaborations are essential, because this work cannot be accomplished on a national level
Life satisfaction and resilience in medical school – a six-year longitudinal, nationwide and comparative study
BACKGROUND: This study examined the relationship between life satisfaction among medical students and a basic model of personality, stress and coping. Previous studies have shown relatively high levels of distress, such as symptoms of depression and suicidal thoughts in medical undergraduates. However despite the increased focus on positive psychological health and well-being during the past decades, only a few studies have focused on life satisfaction and coping in medical students. This is the first longitudinal study which has identified predictors of sustained high levels of life satisfaction among medical students. METHODS: This longitudinal, nationwide questionnaire study examined the course of life satisfaction during medical school, compared the level of satisfaction of medical students with that of other university students, and identified resilience factors. T-tests were used to compare means of life satisfaction between and within the population groups. K-means cluster analyses were applied to identify subgroups among the medical students. Analysis of Variance (ANOVA) and logistic regression analyses were used to compare the subgroups. RESULTS: Life satisfaction decreased during medical school. Medical students were as satisfied as other students in the first year of study, but reported less satisfaction in their graduation year. Medical students who sustained high levels of life satisfaction perceived medical school as interfering less with their social and personal life, and were less likely to use emotion focused coping, such as wishful thinking, than their peers. CONCLUSION: Medical schools should encourage students to spend adequate time on their social and personal lives and emphasise the importance of health-promoting coping strategies
Size Dependence of a Temperature-Induced Solid–Solid Phase Transition in Copper(I) Sulfide
Determination of the phase diagrams for the nanocrystalline forms of materials is crucial for our understanding of nanostructures and the design of functional materials using nanoscale building blocks. The ability to study such transformations in nanomaterials with controlled shape offers further insight into transition mechanisms and the influence of particular facets. Here we present an investigation of the size-dependent, temperature-induced solid-solid phase transition in copper sulfide nanorods from low- to high-chalcocite. We find the transition temperature to be substantially reduced, with the high chalcocite phase appearing in the smallest nanocrystals at temperatures so low that they are typical of photovoltaic operation. Size dependence in phase trans- formations suggests the possibility of accessing morphologies that are not found in bulk solids at ambient conditions. These other- wise-inaccessible crystal phases could enable higher-performing materials in a range of applications, including sensing, switching, lighting, and photovoltaics
Toward Practical Biological Control of Parasitic Nematodes in Domestic Animals
In a series of laboratory and field experiments where the nematophagous fungus Arthrobotrys oligospora was mixed directly with feces it has been demonstrated that it is possible to use nematophagous fungi for biological control of animal parasitic nematodes. A procedure used for selection of nematophagous fungi that can pass the digestive tract of ruminants, horses, and pigs is described. The selected fungus, Duddingtonia flagrans, has been used in further field experiments, and the results have confirmed that by the addition of D. flagrans to feed supplement it is possible to reduce the parasitic burden significantly
Growth rate and trapping efficacy of nematode-trapping fungi under constant and fluctuating temperatures
The influence of surface treatment on the fatigue properties of titanium and titanium alloys : progress report no. 2.
http://deepblue.lib.umich.edu/bitstream/2027.42/7942/5/bad3274.0002.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/7942/4/bad3274.0002.001.tx
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