Thermal stress response of General Purpose Heat Source (GPHS) aeroshell material

A thermal stress test was conducted to determine the ability of the GPHS aeroshell 3 D FWPF material to maintain physical integrity when exposed to a severe heat flux such as would occur from prompt reentry of GPHS modules. The test was performed in the Giant Planetary Facility at NASA's Ames Research Center. Good agreement was obtained between the theoretical and experimental results for both temperature and strain time histories. No physical damage was observed in the test specimen. These results provide initial corroboration both of the analysis techniques and that the GPHS reentry member will survive the reentry thermal stress levels expected

Phonon Band Structure and Thermal Transport Correlation in a Layered Diatomic Crystal

To elucidate the relationship between a crystal's structure, its thermal conductivity, and its phonon dispersion characteristics, an analysis is conducted on layered diatomic Lennard-Jones crystals with various mass ratios. Lattice dynamics theory and molecular dynamics simulations are used to predict the phonon dispersion curves and the thermal conductivity. The layered structure generates directionally dependent thermal conductivities lower than those predicted by density trends alone. The dispersion characteristics are quantified using a set of novel band diagram metrics, which are used to assess the contributions of acoustic phonons and optical phonons to the thermal conductivity. The thermal conductivity increases as the extent of the acoustic modes increases, and decreases as the extent of the stop bands increases. The sensitivity of the thermal conductivity to the band diagram metrics is highest at low temperatures, where there is less anharmonic scattering, indicating that dispersion plays a more prominent role in thermal transport in that regime. We propose that the dispersion metrics (i) provide an indirect measure of the relative contributions of dispersion and anharmonic scattering to the thermal transport, and (ii) uncouple the standard thermal conductivity structure-property relation to that of structure-dispersion and dispersion-property relations, providing opportunities for better understanding of the underlying physical mechanisms and a potential tool for material design.Comment: 30 pages, 10 figure

Influence of Graft Type on Outcomes After Pediatric Liver Transplantation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74904/1/j.1600-6143.2004.00359.x.pd

What really matters about teacher education at Cathedrals Group Universities: volume 2 the case studies

The case studies show insight into the extent that there is a shared understanding between schools, students and staff members in some of England’s oldest providers of teacher education in England. Is there something particular about that provision? Could it be described as distinctively, implicitly or explicitly Christian? Is there a sense of shared thinking about the answers to these questions in the provision of teacher education and the students, university tutors and school staff members who partner with these universities to educate the next generation of teachers? This document provides five answers to those questions. The answers are snapshots of the perception of teacher education at these universities, at a time when teacher education has become a major purpose of schools, and universities have found themselves being questioned and challenged about their role in the development of new teachers

The Role of Polar Pili in the Adherence of Pseudomonas Aeruginosa to Injured Canine Tracheal Cells: A Semiquantitative Morphologic Study

Pseudomonas aeruginosa adheres to respiratory epithelial cells in a highly specific fashion. In order to study the role of P. aeruginosa polar pili in the adherence process we conducted a quantitative morphological electron microscopic examination of P. aeruginosa adherence to SO2 injured canine tracheal cells in vitro. A pilin lacking background strain of P. aeruginosa PAK (BLP2) was constructed using a gene replacement and it in turn was engineered to express either the pilin gene of P. aeruginosa PAO, PAK , or no pilin gene . After 30 minutes incubation of these bacterial strains with injured canine tracheal rings the P. aeruginosa strains expressing pili adhered quantitatively more to the injured tracheal cells than did the pili lacking strains. PAO bearing strains adhered in greater numbers than PAK bearing strains. Healthy tracheal cells did not have any bacteria bound to their surfaces. The bacteria bound to the cilia and lateral edge of the exfoliating tracheal cells. Invasion of tracheal cells by piliated P. aeruginosa bacteria and penetration into the submucosa was also demonstrated. These data confirm the role of pili as important adhesins to injured tracheal cells. The difference in the adherence characteristics of pilin types PAK versus PAO may relate to the differences in the primary structure of these two pilin molecules

The Diabetes and WELLbeing programme: protocol of a multi-site European complex intervention study

A quasi-experimental design evaluation study examines long-term impact of the 12-week DWELL programme, a self-management intervention for people with type 2 diabetes (T2D), based on adult learning and person-centred approaches, delivered in 5 community and hospital sites in 4 European countries. Overall target is 780 people with T2D. Staff are trained in motivational interviewing, group facilitation, diabetes education, and programme approach which consists of core and ‘pick and mix’ sessions on diabetes education, physical activity, healthy eating and wellbeing. Pre-post measures are taken at baseline (T0), end-of-programme (T1), at 6 months (T2) and 12 months (T3). There is a non-equivalent control group of 190 at T2/T3. Biomedical data are collected by staff and psychosocial data are collected via self-completed validated scales. Metabolic measures include: HbA1c, BMI and waist circumference. Demographics capture: age, gender, ethnicity, household composition, education, employment, income. Psychosocial data are collected on illness perception, patient empowerment, eating behaviours, physical activity, physical/mental health status, health-related quality of life (EQ-5D), use of diabetes-related health services and self-care activities. Participant experiences are recorded via motivational interviews at T0 and T1 and focus groups at T1. Process evaluation data are collected via interviews with staff and patient ambassadors. The DWELL programme started in 2018 and results will be available in 2021. The study will produce rich data on long-term impact of intervention to allow replication and further development. It will permit cross-border conclusions on sustainability and embeddedness of model in varied service settings, and empowerment-based public health approach to T2D self-management

Evaluation of a novel computer vision-based livestock monitoring system to identify and track specific behaviors of individual nursery pigs within a group-housed environment

Animal behavior is indicative of health status and changes in behavior can indicate health issues (i.e., illness, stress, or injury). Currently, human observation (HO) is the only method for detecting behavior changes that may indicate problems in group-housed pigs. While HO is effective, limitations exist. Limitations include HO being time consuming, HO obfuscates natural behaviors, and it is not possible to maintain continuous HO. To address these limitations, a computer vision platform (NUtrack) was developed to identify (ID) and continuously monitor specific behaviors of group-housed pigs on an individual basis. The objectives of this study were to evaluate the capabilities of the NUtrack system and evaluate changes in behavior patterns over time of group-housed nursery pigs. The NUtrack system was installed above four nursery pens to monitor the behavior of 28 newly weaned pigs during a 42-d nursery period. Pigs were stratified by sex, litter, and randomly assigned to one of two pens (14 pigs/pen) for the first 22 d. On day 23, pigs were split into four pens (7 pigs/pen). To evaluate the NUtrack system’s capabilities, 800 video frames containing 11,200 individual observations were randomly selected across the nursery period. Each frame was visually evaluated to verify the NUtrack system’s accuracy for ID and classification of behavior. The NUtrack system achieved an overall accuracy for ID of 95.6%. This accuracy for ID was 93.5% during the first 22 d and increased (P \u3c 0.001) to 98.2% for the final 20 d. Of the ID errors, 72.2% were due to mislabeled ID and 27.8% were due to loss of ID. The NUtrack system classified lying, standing, walking, at the feeder (ATF), and at the waterer (ATW) behaviors accurately at a rate of 98.7%, 89.7%, 88.5%, 95.6%, and 79.9%, respectively. Behavior data indicated that the time budget for lying, standing, and walking in nursery pigs was 77.7% ± 1.6%, 8.5% ± 1.1%, and 2.9% ± 0.4%, respectively. In addition, behavior data indicated that nursery pigs spent 9.9% ± 1.7% and 1.0% ± 0.3% time ATF and ATW, respectively. Results suggest that the NUtrack system can detect, identify, maintain ID, and classify specific behavior of group-housed nursery pigs for the duration of the 42-d nursery period. Overall, results suggest that, with continued research, the NUtrack system may provide a viable real-time precision livestock tool with the ability to assist producers in monitoring behaviors and potential changes in the behavior of group-housed pigs

Self-energy of image states on copper surfaces

We report extensive calculations of the imaginary part of the electron self-energy in the vicinity of the (100) and (111) surfaces of Cu. The quasiparticle self-energy is computed by going beyond a free-electron description of the metal surface, either within the GW approximation of many-body theory or with inclusion, within the GW$\Gamma$ approximation, of short-range exchange-correlation effects. Calculations of the decay rate of the first three image states on Cu(100) and the first image state on Cu(111) are also reported, and the impact of both band structure and many-body effects on the electron relaxation process is discussed.Comment: 8 pages, 5 figures, to appear in Phys. Rev.

Analytical approaches for transplant research

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73605/1/j.1600-6135.2004.00402.x.pd

The Long Life of Birds: The Rat-Pigeon Comparison Revisited

The most studied comparison of aging and maximum lifespan potential (MLSP) among endotherms involves the 7-fold longevity difference between rats (MLSP 5y) and pigeons (MLSP 35y). A widely accepted theory explaining MLSP differences between species is the oxidative stress theory, which purports that reactive oxygen species (ROS) produced during mitochondrial respiration damage bio-molecules and eventually lead to the breakdown of regulatory systems and consequent death. Previous rat-pigeon studies compared only aspects of the oxidative stress theory and most concluded that the lower mitochondrial superoxide production of pigeons compared to rats was responsible for their much greater longevity. This conclusion is based mainly on data from one tissue (the heart) using one mitochondrial substrate (succinate). Studies on heart mitochondria using pyruvate as a mitochondrial substrate gave contradictory results. We believe the conclusion that birds produce less mitochondrial superoxide than mammals is unwarranted