305 research outputs found

    Adhesive and TIG Joining Nickel-Titanium to 304 Stainless Steel

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    Nickel-titanium (NiTi) contains a unique set of properties which make it a desirable candidate for aeronautic applications. NiTi’s most useful characteristic comes from being a Shape Memory Alloy (SMA). With the proper thermo-mechanical training regimen, a NiTi tube can generate high stress as it rotates through large amounts of strain based on a thermal triggering condition. The rotation cycle is controlled by the temperature of the alloy and it is fully recoverable with up to 8% strain. This rotation lends itself well to function as a solid state actuator. Solid state actuators are beneficial over the traditional hydraulic or electrical actuators because they show the potential to be small, lightweight, and survive harsh conditions. Despite these advantages, NiTi has limitations, including poor machinability. This project looks into testing different methods of joining NiTi with structural materials to enable system integration. Once NiTi can be consistently joined with a machineable material its application will become more practical. This project investigates different ways to join Nickel-Titanium with structural materials to accelerate system integration.Boeing Inc.Edison Welding InstituteNo embarg

    Supreme Court Voting Behavior: 1989 Term

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    Chase Policy

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    Evaluates the need for a comprehensive written pursuit policy

    Community water fluoridation : is it still worthwhile

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    Community Water Fluoridation (CWF) is the adjustment of fluoride concentration in community drinking water to a level that confers optimal protection from dental caries (Truman et al 2002). It is supported by many authorities as the single most effective public health measure for reducing dental caries (DHS 2007). It has consistently been shown to be effective in reducing the prevalence and severity of dental caries in populations following its introduction (NHMRC 1999). The most dramatic reductions (50-60%) were demonstrated in the earlier studies although more recent research has still shown reductions of between 30 and 50% (Truman et al 2002). Despite the strong scientific evidence for its beneficial effects and safety the issue of the appropriateness of CWF is often the focus of public debate. Proponents argue that it reduces dental caries. is safe and cost effective. and that it provides significant benefits to all social classes (Slade et al 1995: Slade et a 1996: Spencer et al 1996). Opponents question its efficacy and safety and argue that its addition to community water supplies is unethical mass medication (Colquhoun 1990: Diesendorf 1986: Diesendorf et al 1997).More recently, however, there have been important questions raised regarding the continuing benefit of CWF over and above that produced by the widespread use of other sources of fluoride (toothpaste. mouth rinses. varnish and other professionally applied fluorides). Generally, dental caries has declined steeply in the last thirty years and many have observed that dental caries has also reduced in parts of Australia and other countries where there has never been CWF or where it has ceased. It has been suggested that because of the current low population levels of dental caries and the increase in alternate sources of fluoride, CWF no longer offers the benefits it may have in the past. Given this notion, together with the concerns of a minority subgroup of the population regarding the safety of CWF, it is valuable to examine current evidence to answer the question: Is there still a role for CWF in Australia?This paper will firstly examine the history of water fluoridation and its mechanisms of action. Secondly. trends in dental decay experience over the last three decades with particular emphasis on social and geographical inequities in Australia will be described. We also review the current state of scientific evidence for the benefits of CWF including the contribution it makes to the reduction of oral health inequalities. In light of this we will provide a response to the question posed above.<br /

    Land and cryosphere products from Suomi NPP VIIRS: overview and status

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    [1] The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched in October 2011 as part of the Suomi National Polar-Orbiting Partnership (S-NPP). The VIIRS instrument was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer and provide observation continuity with NASA's Earth Observing System's Moderate Resolution Imaging Spectroradiometer (MODIS). Since the VIIRS first-light images were received in November 2011, NASA- and NOAA-funded scientists have been working to evaluate the instrument performance and generate land and cryosphere products to meet the needs of the NOAA operational users and the NASA science community. NOAA's focus has been on refining a suite of operational products known as Environmental Data Records (EDRs), which were developed according to project specifications under the National Polar-Orbiting Environmental Satellite System. The NASA S-NPP Science Team has focused on evaluating the EDRs for science use, developing and testing additional products to meet science data needs, and providing MODIS data product continuity. This paper presents to-date findings of the NASA Science Team's evaluation of the VIIRS land and cryosphere EDRs, specifically Surface Reflectance, Land Surface Temperature, Surface Albedo, Vegetation Indices, Surface Type, Active Fires, Snow Cover, Ice Surface Temperature, and Sea Ice Characterization. The study concludes that, for MODIS data product continuity and earth system science, an enhanced suite of land and cryosphere products and associated data system capabilities are needed beyond the EDRs currently available from the VIIRS

    An exploratory trial implementing a community-based child oral health promotion intervention for Australian families from refugee and migrant backgrounds: a protocol paper for Teeth Tales

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    Introduction: Inequalities are evident in early childhood caries rates with the socially disadvantaged experiencing greater burden of disease. This study builds on formative qualitative research, conducted in the Moreland/Hume local government areas of Melbourne, Victoria 2006–2009, in response to community concerns for oral health of children from refugee and migrant backgrounds. Development of the community-based intervention described here extends the partnership approach to cogeneration of contemporary evidence with continued and meaningful involvement of investigators, community, cultural and government partners. This trial aims to establish a model for child oral health promotion for culturally diverse communities in Australia.&lt;p&gt;&lt;/p&gt; Methods and analysis: This is an exploratory trial implementing a community-based child oral health promotion intervention for Australian families from refugee and migrant backgrounds. Families from an Iraqi, Lebanese or Pakistani background with children aged 1–4 years, residing in metropolitan Melbourne, were invited to participate in the trial by peer educators from their respective communities using snowball and purposive sampling techniques. Target sample size was 600. Moreland, a culturally diverse, inner-urban metropolitan area of Melbourne, was chosen as the intervention site. The intervention comprised peer educator led community oral health education sessions and reorienting of dental health and family services through cultural Competency Organisational Review (CORe).&lt;p&gt;&lt;/p&gt; Ethics and dissemination: Ethics approval for this trial was granted by the University of Melbourne Human Research Ethics Committee and the Department of Education and Early Childhood Development Research Committee. Study progress and output will be disseminated via periodic newsletters, peer-reviewed research papers, reports, community seminars and at National and International conferences.&lt;p&gt;&lt;/p&gt

    Effect of chronic stress on running wheel activity in mice

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    Acute and chronic stress have been reported to have differing effects on physical activity in rodents, but no study has examined a chronic stress protocol that incorporates stressors often experienced by rodents throughout a day. To examine this, the effects of the Unpredict- able Chronic Mild Stress (UCMS) protocol on voluntary running wheel activity at multiple time points, and/or in response to acute removal of chronic stress was determined. Twenty male Balb/c mice were given access and accustomed to running wheels for 4 weeks, after which they were randomized into 2 groups; exercise (EX, n = 10) and exercise with chronic stress using a modified UCMS protocol for 7 hours/day (8:00 a.m.-3:00p.m.), 5 days/week for 8 weeks (EXS, n = 10). All mice were given access to running wheels from approximately 3:30 p.m. to 7:30 a.m. during the weekday, however during weekends mice had full-time access to running wheels (a time period of no stress for the EXS group). Daily wheel running distance and time were recorded. The average running distance, running time, and work each week- day was significantly lower in EXS compared to EX mice, however, the largest effect was seen during week one. Voluntary wheel running deceased in all mice with increasing age; the pattern of decline appeared to be similar between groups. During the weekend (when no stress was applied), EXS maintained higher distance compared to EX, as well as higher daily distance, time, and work compared to their weekday values. These results indicate that mild chronic stress reduces total spontaneous wheel running in mice during the first week of the daily stress induction and maintains this reduced level for up to 8 consecutive weeks. How- ever, following five days of UCMS, voluntary running wheel activity rebounds within 2–3 days

    Postnatal Pancreas of Mice Contains Tripotent Progenitors Capable of Giving Rise to Duct, Acinar, and Endocrine Cells In Vitro

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    Postnatal pancreas is a potential source for progenitor cells to generate endocrine β-cells for treating type 1 diabetes. However, it remains unclear whether young (1-week-old) pancreas harbors multipotent progenitors capable of differentiating into duct, acinar, and endocrine cells. Laminin is an extracellular matrix (ECM) protein important for β-cells' survival and function. We established an artificial extracellular matrix (aECM) protein that contains the functional IKVAV (Ile-Lys-Val-Ala-Val) sequence derived from laminin (designated aECM-lam). Whether IKVAV is necessary for endocrine differentiation in vitro is unknown. To answer these questions, we cultured single cells from 1-week-old pancreas in semi-solid media supplemented with aECM-lam, aECM-scr (which contains a scrambled sequence instead of IKVAV), or Matrigel. We found that colonies were generated in all materials. Individual colonies were examined by microfluidic reverse transcription-polymerase chain reaction, immunostaining, and electron microscopy analyses. The majority of the colonies expressed markers for endocrine, acinar, and ductal lineages, demonstrating tri-lineage potential of individual colony-forming progenitors. Colonies grown in aECM-lam expressed higher levels of endocrine markers Insulin1, Insulin2, and Glucagon compared with those grown in aECM-scr and Matrigel, indicating that the IKVAV sequence enhances endocrine differentiation. In contrast, Matrigel was inhibitory for endocrine gene expression. Colonies grown in aECM-lam displayed the hallmarks of functional β-cells: mature insulin granules and glucose-stimulated insulin secretion. Colony-forming progenitors were enriched in the CD133^(high) fraction and among 230 micro-manipulated single CD133^(high) cells, four gave rise to colonies that expressed tri-lineage markers. We conclude that young postnatal pancreas contains multipotent progenitor cells and that aECM-lam promotes differentiation of β-like cells in vitro
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