4,333 research outputs found
Wind Tunnel Test of Low Boom Equivalent Body at Mach 4
A body of revolution, representing the equivalent area distribution of a low boom aircraft design cruising at 24,384 meters at a Mach number of 4, was tested to determine whether its theoretical sonic boom characteristics could be experimentally verified. Results indicate that the essential features of the ground signature are well predicted
The clinical impact of assay standardization and traceability: A case study of cholesterol
Coronary heart disease (CHD) is the major cause of death internationally, and yet most can be prevented using population-wide strategies by addressing behavioral risk factors, including reduction of blood cholesterol levels. Following the definition of clinical decision limits for cholesterol according to risk of CHD, an international effort was undertaken to establish traceability of routine clinical cholesterol assays to improve reproducibility and accuracy. This task has been achieved through the establishment of the Cholesterol Reference Measurement Laboratory Network. This work is associated with a reduction in the number of persons with elevated cholesterol levels and reduction in the death rates from CHD. It has been a major achievement for the discipline of laboratory medicine and a guide for future efforts for the improvement of patient outcomes
Osteoporosis Prevention—A Worthy and Achievable Strategy
This special issue of Nutrients records seven of the presentations made to the very successful meeting titled “Osteoporosis Prevention: A Workshop on Calcium, Vitamin D and other Nutritional Aspects” held in Adelaide, Australia on 5 and 6 March 2010 [1-7]. Seventy six delegates attended from across Australia and New Zealand to review the current evidence that dietary calcium intake, vitamin D status, other nutrients and exercise play a significant role in bone mineral homeostasis and act to prevent the development of osteoporosis. The Workshop promoted the concept that osteoporosis is a predictable and preventable disease and that significant benefit would be achieved to reduce the incidence of osteoporosis and the risk of fractures from nutrition and life style activities. Such an achievement will not only save considerable pain, suffering and morbidity but will also have a major financial benefit for the healthcare system for which the cost of treatment for osteoporotic fractures already amounts to billions of dollars
Chromospheric Activity of HAT-P-11: an Unusually Active Planet-Hosting K Star
Kepler photometry of the hot Neptune host star HAT-P-11 suggests that its
spot latitude distribution is comparable to the Sun's near solar maximum. We
search for evidence of an activity cycle in the CaII H & K chromospheric
emission -index with archival Keck/HIRES spectra and observations from the
echelle spectrograph on the ARC 3.5 m Telescope at APO. The chromospheric
emission of HAT-P-11 is consistent with a year activity cycle,
which plateaued near maximum during the Kepler mission. In the cycle that we
observed, the star seemed to spend more time near active maximum than minimum.
We compare the normalized chromospheric emission index of
HAT-P-11 with other stars. HAT-P-11 has unusually strong chromospheric emission
compared to planet-hosting stars of similar effective temperature and rotation
period, perhaps due to tides raised by its planet.Comment: 16 pages, 8 figures; accepted to the Astrophysical Journa
Vitamin D metabolism and molecular modes of action: new insights into vitamin D activities
Reports of significant health benefits from an adequate vitamin D status continue to generate considerable interest. Knowledge of the molecular actions of the vitamin D system, including the nuclear vitamin D receptor and other receptors for 1,25-dihydroxy vitamin D and vitamin D status, provides evidence for vitamin D system to exert biological activities with physiological sensitivities and specificities across a wide range of tissues in a similar manner to other nuclear receptor hormones. This knowledge provides physiological plausibility for the wide range of activities claimed for vitamin D from largely observational studies and supports proposals for well-conducted clinical trials
Galactose Transport in \u3ci\u3eStreptococcus thermophilus\u3c/i\u3e
Although Streptococcus thermophilus accumulated [14C]lactose in the absence of an endogenous energy source, galactose-fermenting (Gal+) cells were unable to accumulate [14C]galactose unless an additional energy source was added to the test system. Both Gal+ and galactose-nonfermenting (Gal-) strains transported galactose when preincubated with sucrose. Accumulation was inhibited 50 or 95% when 10 niM sodium fluoride or 1.0 mM iodoacetic acid, respectively, was added to sucrose-treated cells, indicating that ATP was required for galactose transport activity. Proton-conducting ionophores also inhibited galactose uptake, although N,N\u27-dicyclohexyl carbodiimide had no effect. The results suggest that galactose transport in S. thermophilus occurs via an ATP-dependent galactose permease and that a proton motive force is involved. The galactose permease in S. thermophilus TS2b (Gal+) had a Km for galactose of 0.25 mM and a Vmax of 195 μmol of galactose accumulated per min per g (dry weight) of cells. Several structurally similar sugars inhibited galactose uptake, indicating that the galactose permease had high affinities for these sugars
Explorations in anatomy: the remains from Royal London Hospital
This paper considers the faunal remains from recent excavations at the Royal London Hospital. The remains date to the beginning of the 19th century and offer an insight into the life of the hospital's patients and practices of the attached medical school. Many of the animal remains consist of partially dissected skeletons, including the unique finds of Hermann's tortoise (Testudo hermanni) and Cercopithecus monkey. The hospital diet and developments in comparative anatomy are discussed by integrating the results with documentary research. They show that zooarchaeological study of later post-medieval material can significantly enhance our understanding of the exploitation of animals in this perio
The receptor protein tyrosine phosphatase PTPRB negatively regulates FGF2-dependent branching morphogenesis
PTPRB is a transmembrane protein tyrosine phosphatase known to regulate blood vessel remodelling and angiogenesis. Here we demonstrate that PTPRB negatively regulates branching morphogenesis in the mammary epithelium. We show that Ptprb is highly expressed in adult mammary stem cells and also, although at lower levels, in estrogen receptor positive luminal cells. During mammary development Ptprb expression is down-regulated during puberty, a period of extensive of ductal outgrowth and branching. In vivo shRNA knockdown of Ptprb in the cleared mammary fat pad transplant assay resulted in smaller epithelial outgrowths with an increased branching density and also increased branching in an in vitro organoid assay. Organoid branching was dependent on stimulation by FGF2, and Ptprb knockdown in mammary epithelial cells resulted in a higher level of FGFR activation and ERK1/2 phosphorylation, both at baseline and following FGF2 stimulation. Therefore, PTPRB regulates branching morphogenesis in the mammary epithelium by modulating the response of the FGFR signalling pathway to FGF stimulation. Considering the importance of branching morphogenesis in multiple taxa, our findings have general importance outside mammary developmental biology
Molecular Epidemiology of Eastern Equine Encephalitis Virus, New York
Southern strains are undergoing amplification, perpetuation, and overwintering in New York
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