377 research outputs found
Low-temperature solder for joining large cryogenic structures
Three joining methods were considered for use in fabricating cooling coils for the National Transonic Facility. After analysis and preliminary testing, soldering was chosen as the cooling coil joining technique over mechanical force fit and brazing techniques. Charpy V-Notch tests, cyclic thermal tests (ambient to 77.8 K) and tensile tests at cryogenic temperatures were performed on solder joints to evaluate their structural integrity. It was determined that low temperature solder can be used to ensure good fin-to-tube contact for cooling-coil applications
Characterization and inheritance assessment of fruit and leaf shape in unique Vitis seedlings
From August to October of 2009, two separate studies were conducted to assess fruit shape of Vitis section Euvitis hybrid bunch grapes using digital photography (Study 1) and evaluate inheritance of leaf shape in unique populations of V. rotundifolia hybrids (Vitis section Muscadinia) (Study 2). All vines studied were located at the University of Arkansas Fruit Research Station, Clarksville. Study 1 used SigmaScan® digital photography analysis software to calculate shape factor, major:minor axis ratio, and compactness of highly variable, unique-shaped fruit from a population of 182 Euvitis seedlings. SigmaScan® accurately characterized fruit shape elongation as had been recorded in previous studies. Although elongated shapes were measured accurately, the calculations used were unable to conclusively analyze ovoid or pear-shaped fruits. Study 2 evaluated the inheritance of leaf shape (lobing) in several populations of V. rotundifolia crosses within the University of Arkansas fruit breeding program. Based on previous studies, it was hypothesized that leaf lobing was a dominant trait. The two populations expected to segregate into a 3:1, lobed:standard, phenotypic ratio were successfully observed, while only two of the six expected to demonstrate a 1:1, lobed:standard, phenotypic ratio were observed. Previous studies suggest the unexpected ratios observed may be attributed to a lethal allele combination, where homozygous dominant progeny are not viable, or modifier genes impacted leaf shape of the seedlings. Further evaluation of these and other populations in addition to molecular analysis would be helpful in characterizing inheritance of leaf lobing in muscadine hybrid
Sequence determinants of human microsatellite variability
<p>Abstract</p> <p>Background</p> <p>Microsatellite loci are frequently used in genomic studies of DNA sequence repeats and in population studies of genetic variability. To investigate the effect of sequence properties of microsatellites on their level of variability we have analyzed genotypes at 627 microsatellite loci in 1,048 worldwide individuals from the HGDP-CEPH cell line panel together with the DNA sequences of these microsatellites in the human RefSeq database.</p> <p>Results</p> <p>Calibrating PCR fragment lengths in individual genotypes by using the RefSeq sequence enabled us to infer repeat number in the HGDP-CEPH dataset and to calculate the mean number of repeats (as opposed to the mean PCR fragment length), under the assumption that differences in PCR fragment length reflect differences in the numbers of repeats in the embedded repeat sequences. We find the mean and maximum numbers of repeats across individuals to be positively correlated with heterozygosity. The size and composition of the repeat unit of a microsatellite are also important factors in predicting heterozygosity, with tetra-nucleotide repeat units high in G/C content leading to higher heterozygosity. Finally, we find that microsatellites containing more separate sets of repeated motifs generally have higher heterozygosity.</p> <p>Conclusions</p> <p>These results suggest that sequence properties of microsatellites have a significant impact in determining the features of human microsatellite variability.</p
A variational approach to strongly damped wave equations
We discuss a Hilbert space method that allows to prove analytical
well-posedness of a class of linear strongly damped wave equations. The main
technical tool is a perturbation lemma for sesquilinear forms, which seems to
be new. In most common linear cases we can furthermore apply a recent result
due to Crouzeix--Haase, thus extending several known results and obtaining
optimal analyticity angle.Comment: This is an extended version of an article appeared in
\emph{Functional Analysis and Evolution Equations -- The G\"unter Lumer
Volume}, edited by H. Amann et al., Birkh\"auser, Basel, 2008. In the latest
submission to arXiv only some typos have been fixe
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Utilization of ash from municipal solid waste combustion
This ash study investigated the beneficial use of municipal waste combustion combined ash from the H-POWER facility in Oahu. These uses were grouped into intermediate cover for final closure of the Waipahu landfill, daily cover at the Waimanalo Gulch Landfill, and partial replacement for aggregate in asphalt for road paving. All proposed uses examine combined fly and bottom ash from a modern waste-to-energy facility that meets requirements of the Clean Air Act Amendments for Maximum Achievable Control Technology
A voice for change? Trust relationships between ombudsmen, individuals and public service providers
There has been a debate for years about what the role of the ombudsman is. This article examines a key component of the role, to promote trust in public services and government. To be able to do this, however, an ombudsman needs to be perceived as legitimate and be trusted by a range of stakeholders, including the user. This article argues that three key relationships in a person’s complaint journey can build trust in an institution, and must therefore be understood as a system. The restorative justice framework is adapted to conceptualize this trust model as a novel approach to understanding the institution from the perspective of its users. Taking two public sector ombudsmen as examples, the article finds that voice and trust need to be reinforced through the relationships in a consumer journey to manage individual expectations, prevent disengagement, and thereby promote trust in the institution, in public service providers, and in government
Higher-Order Oligomerization Targets Plasma Membrane Proteins and HIV Gag to Exosomes
Exosomes are secreted organelles that have the same topology as the cell and bud outward (outward is defined as away from the cytoplasm) from endosome membranes or endosome-like domains of plasma membrane. Here we describe an exosomal protein-sorting pathway in Jurkat T cells that selects cargo proteins on the basis of both higher-order oligomerization (the oligomerization of oligomers) and plasma membrane association, acts on proteins seemingly without regard to their function, sequence, topology, or mechanism of membrane association, and appears to operate independently of class E vacuolar protein-sorting (VPS) function. We also show that higher-order oligomerization is sufficient to target plasma membrane proteins to HIV virus–like particles, that diverse Gag proteins possess exosomal-sorting information, and that higher-order oligomerization is a primary determinant of HIV Gag budding/exosomal sorting. In addition, we provide evidence that both the HIV late domain and class E VPS function promote HIV budding by unexpectedly complex, seemingly indirect mechanisms. These results support the hypothesis that HIV and other retroviruses are generated by a normal, nonviral pathway of exosome biogenesis
Lighting the fuse: Cultivating the masculine physics habitus – a case study of Victor aged 10-18
This chapter presents a longitudinal case study analysis of Victor, a young man who was interviewed from the ages of 10–19, together with his mother, Sam, and who went on to study for a degree in astrophysics. We apply a Bourdieusian conceptual lens to the data, to explore how interactions of capital, habitus and field combine to possibilise Victor and his trajectory to being/becoming a physicist. We also identify specific alignments of his habitus and capital with dominant notions of masculinity and ‘cleverness’ that are demanded and normalised within physics and which, we argue, are key to the reproduction of the elite nature of physics
Identification of publicly available data sources to inform the conduct of Health Technology Assessment in India
Background: Health technology assessment (HTA) provides a globally-accepted and structured approach to synthesising evidence for cost and clinical effectiveness alongside ethical and equity considerations to inform evidence-based priorities. India is one of the most recent countries to formally commit to institutionalising HTA as an integral component of the heath resource allocation decision-making process. The effective conduct of HTA depends on the availability of reliable data. Methods: We draw from our experience of collecting, synthesizing, and analysing health-related datasets in India and internationally, to highlight the complex requirements for undertaking HTA, and explore the availability of such data in India. We first outlined each of the core data components required for the conduct of HTA, and their availability in India, drawing attention to where data can be accessed, and different ways in which researchers can overcome the challenges of missing or low quality data. Results: We grouped data into the following categories: clinical efficacy; cost; epidemiology; quality of life; service use/consumption; and equity. We identified numerous large local data sources containing epidemiological information. There was a marked absence of other locally-collected data necessary for informing HTA, particularly data relating to cost, service use, and quality of life. Conclusions: The introduction of HTA into the health policy space in India provides an opportunity to comprehensively assess the availability and quality of health data capture across the country. While epidemiological information is routinely collected across India, other data inputs necessary for HTA are not readily available. This poses a significant bottleneck to the efficient generation and deployment of HTA into the health decision space. Overcoming these data gaps by strengthening the routine collection of comprehensive and verifiable health data will have important implications not only for embedding economic analyses into the priority setting process, but for strengthening the health system as a whole
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