8,230 research outputs found
Research and development of magnesium/aluminum electroforming process for solar concentrators Final report, 13 May 1966 - 10 May 1967
Magnesium and aluminum electroforming process for solar concentrator
Radial distribution of the inner magnetosphere plasma pressure using low-altitude satellite data during geomagnetic storm: the March 1-8, 1982 Event
Plasma pressure distribution in the inner magnetosphere is one of the key
parameters for understanding the main magnetospheric processes including
geomagnetic storms and substorms. However, the pressure profiles obtained from
in-situ particle measurements by the high-altitude satellites do not allow
tracking the pressure variations related to the storms and substorms, because a
time interval needed to do this generally exceeds the characteristic times of
them. On contrary, fast movement of low-altitude satellites makes it possible
to retrieve quasi-instantaneous profiles of plasma pressure along the satellite
trajectory, using the fluxes of precipitating particles. For this study, we
used the Aureol-3 satellite data for plasma pressure estimation, and the IGRF,
Tsyganenko 2001 and Tsyganenko 2004 storm time geomagnetic field models for the
pressure mapping into the equatorial plane. It was found that during quiet
geomagnetic condition the radial pressure profiles obtained coincide with the
profiles, obtained previously from the high-altitude measurements. On the
contrary, it was found that during geomagnetic storm the plasma pressure
profiles became sharper; the position of the maximum of plasma pressure
corresponds to expected one for given Dst minimum; the maximum value of inner
magnetosphere static pressure correlates with the solar wind dynamic pressure.
Increase in the plasma pressure profiles indicates the possibility to consider
the interchange instability as one of important factors for the development of
the main phase of geomagnetic storm.Comment: Accepted in Advances in Space Researc
Automatic Error Correction in Optics Models Using a New Method for Localized Component Calibration
Distinct Scaling Regimes of Energy Release Dynamics in the Nighttime Magnetosphere
Based on a spatiotemporal analysis of POLAR UVI images, we show that the
auroral emission events that initiate equatorward of the isotropic boundary
(IB) obtained from a time-dependent empirical model, have systematically
steeper power-law slopes of energy, power, area and lifetime probability
distributions compared to the events that initiate poleward of the IB. The
low-latitude group of events contains a distinct subpopulation of
substorm-scale disturbances violating the power-law behavior, while the high
latitude group is described by nearly perfect power-law statistics over the
entire range of scales studied. The results obtained indicate that the inner
and outer portions of the plasma sheet are characterized by substantially
different scaling regimes of bursty energy dissipation suggestive of different
physics in these regions.Comment: 11 pages, 2 figures, 2 table
Pisum Sativum L. cultivars : characterization and identification by electrophoresis of total seed proteins
Se realizó el estudio electroforético de
proteínas seminales totales de 13 cultivares
de arveja (Pisum sativum L.) en geles de
poliacrilamida con Sodio Dodecil Sulfato. Se
logró fraccionar 53 bandas proteicas, de las
cuales 36 mostraron diferencias en sus movilidades.
De esta manera se obtuvieron modelos
electroforéticos diferentes para cada
cultivar y mediante análisis de conglomerados
(método UPGMA) se obtuvo un
dendrograma que mostró la distinción entre
cultivares en dicho carácter, permitiendo
expresar las diferencias entre ellos.Electrophoretic study of reduced total
seed proteins of 13 pea cultivars has been
carried on polyacrylamide gels in the
presence of Sodium Dodecyl Sulphate. The
pea seed storage proteins were
electrophoretically separated in 53 bands; 36
of them showed qualitative differences and
allowed the characterization of the cultivars.
Standard reference patterns of each cultivar
were obtained on this basis. UPGMA analysis
was performed on the gels and in the
resulting dendrogram 12 clusters of different
orders have been determined. Intervarietal
differences were clearly expressed.Fil: Cevedo, Alicia M. L..Fil: Galussi, Alberto A..Fil: Lui, Lino M.
Effect of Combination Folic Acid, Vitamin B6 , and Vitamin B12 Supplementation on Fracture Risk in Women: A Randomized, Controlled Trial.
Epidemiologic studies have demonstrated an association of elevated plasma homocysteine levels with greater bone resorption and fracture risk. Vitamins B12 , B6 , and folic acid are cofactors in homocysteine metabolism, and supplementation with B vitamins is effective in lowering homocysteine levels in humans. However, randomized trials of supplemental B vitamins for reduction of fracture risk have been limited. Therefore, we performed an ancillary study to the Women's Antioxidant and Folic Acid Cardiovascular Study (WAFACS), a large randomized trial of women with preexisting cardiovascular disease or three or more coronary risk factors, to test whether a daily B vitamin intervention including folic acid (2.5 mg/day), vitamin B6 (50 mg/day), and vitamin B12 (1 mg/day) reduces nonspine fracture risk over 7.3 years of treatment and follow-up. Among 4810 women, we confirmed 349 nonspine fracture cases by centralized review of medical records. In a substudy of 300 women (150 in treatment group and 150 controls) with paired plasma samples at randomization and follow-up (7.3 years later), we measured two bone turnover markers, including C-terminal cross-linking telopeptide of type I collagen (CTX) and intact type I procollagen N-propeptide (P1NP). In Cox proportional hazards models based on intention-to-treat, we found no significant effects of B vitamin supplementation on nonspine fracture risk (relative hazard = 1.08; 95% confidence interval, 0.88 to 1.34). In a nested case-cohort analysis, there were no significant effects of B vitamins on fracture risk among women with elevated plasma homocysteine levels, or low levels of vitamins B12 or B6 , or folate at baseline. Furthermore, treatment with B vitamins had no effect on change in markers of bone turnover. We found no evidence that daily supplementation with B vitamins reduces fracture risk or rates of bone metabolism in middle-aged and older women at high risk of cardiovascular disease. © 2017 American Society for Bone and Mineral Research
Sonic hedgehog regulates the proliferation, differentiation, and migration of enteric neural crest cells in gut
Enteric neural crest cells (NCCs) migrate and colonize the entire gut and proliferate and differentiate into neurons and glia of the enteric nervous system in vertebrate embryos. We have investigated the mitogenic and morphogenic functions of Sonic hedgehog (Shh) on enteric NCCs in cell and organ culture. Enteric NCCs expressed Shh receptor Patched and transcripts encoding the Shh signal transducer (Gli1). Shh promoted the proliferation and inhibited the differentiation of NCCs. The pro-neurogenic effect of glial cell line-derived neurotrophic factor (GDNF) on NCCs was abolished by Shh. In gut explants, NCCs migrated from the explants onto the adjacent substratum if GDNF was added, whereas addition of Shh abolished this migration. Neuronal differentiation and coalescence of neural crest-derived cells into myenteric plexuses in explants was repressed by the addition of Shh. Our data suggest that Shh controls the proliferation and differentiation of NCCs and modulates the responsiveness of NCCs toward GDNF inductions.published_or_final_versio
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