573 research outputs found
Comparison of aerodynamic noise from three nose-cylinder combinations
Results of experiments with three different cylinder and blunted nose combinations are discussed. Combinations include smooth cylinder with single 15 deg cone, smooth cylinder with double cone of 25 and 10 deg, and longitudinally corrugated cylinder with similar double cone
Gust penetration loads and elastic vehicle response for Saturn 5 launch vehicles
Analysis of gust penetration loads and associated elastic vehicle response of Saturn 5 launch vehicles AS-505 through AS-508 penetrating sinusoidal gust
Effects of shock-induced separation Technical summary report
Supersonic and subsonic shock wave boundary layer separation studies on aeroelasticity of Saturn launch vehicle
The Effect of Pre-Diagnostic Alcohol Consumption on Survival after Breast Cancer in Young Women.
Background: Alcohol consumption has been comprehensively investigated as an etiologic risk factor for breast cancer but has received little attention in terms of its impact on prognosis after breast cancer, particularly for young women.
Methods: 1286 women diagnosed with invasive breast cancer at or before 45 years of age from two population-based case-control studies in the Seattle-Puget Sound region were followed from their diagnosis of breast cancer (between January 1983 and December 1992) for survival through June 2002, during which time 364 women had died. Cox proportional hazards modeling was used to assess the effect of pre-diagnostic alcohol consumption on the risk of dying.
Results: After adjusting for age and diagnosis year, compared to non-drinkers, women who consumed alcohol in the 5 years prior to diagnosis had a decreased risk of death [>0 to <3 drinks per week: HR(hazard ratio) = 0.7 (95% CI: 0.6-0.95); 3 to <7 drinks per week: RR = 0.6 (95% CI: 0.4-0.8); ≥ 7 drinks per week: RR = 0.7 (95% CI: 0.5-0.9)]. This association was unchanged upon additional adjustment for potential confounders including most notably treatment, stage at diagnosis, and mammogram history.
Conclusion: These results suggest that women who consume alcohol prior to a diagnosis of breast cancer have improved survival which does not appear to be attributable to differences in stage, screening or treatment
Two New White Dwarfs With Variable Magnetic Balmer Emission Lines
We report the discovery of two apparently isolated stellar remnants that
exhibit rotationally modulated magnetic Balmer emission, adding to the emerging
DAHe class of white dwarf stars. While the previously discovered members of
this class show Zeeman-split triplet emission features corresponding to single
magnetic field strengths, these two new objects exhibit significant
fluctuations in their apparent magnetic field strengths with variability phase.
The Zeeman-split hydrogen emission lines in LP broaden from MG
to MG over an apparent spin period of minutes. Similarly, WD
J varies from MG to MG over its apparent
-minute rotation period. This brings the DAHe class of white dwarfs to
at least five objects, all with effective temperatures within K of
K and masses ranging from .Comment: 7 pages, 3 figures. Accepted for publication in MNRA
Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae
We report the discovery of three stars that, along with the prototype
LP40-365, form a distinct class of chemically peculiar runaway stars that are
the survivors of thermonuclear explosions. Spectroscopy of the four confirmed
LP 40-365 stars finds ONe-dominated atmospheres enriched with remarkably
similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic
evidence is consistent with ejection from a binary supernova progenitor; at
least two stars have rest-frame velocities indicating they are unbound to the
Galaxy. With masses and radii ranging between 0.20-0.28 Msun and 0.16-0.60
Rsun, respectively, we speculate these inflated white dwarfs are the partly
burnt remnants of either peculiar Type Iax or electron-capture supernovae.
Adopting supernova rates from the literature, we estimate that ~20 LP40-365
stars brighter than 19 mag should be detectable within 2 kpc from the Sun at
the end of the Gaia mission. We suggest that as they cool, these stars will
evolve in their spectroscopic appearance, and eventually become peculiar O-rich
white dwarfs. Finally, we stress that the discovery of new LP40-365 stars will
be useful to further constrain their evolution, supplying key boundary
conditions to the modelling of explosion mechanisms, supernova rates, and
nucleosynthetic yields of peculiar thermonuclear explosions.Comment: 22 pages, 14 figures, 6 tables. Accepted for publication on MNRA
The pancreas responds to remote damage and systemic stress by secretion of the pancreatic secretory proteins PSP/regI and PAP/regIII.
In patients with infection and sepsis serum levels of Pancreatic Stone protein/regenerating protein I (PSP) are highly elevated. The origin of PSP during these conditions is presumably the pancreas, however, an intestinal origin cannot be excluded. Similarly, pancreatitis-associated protein (PAP) was identified in the pancreas. These proteins were also localized in intestinal organs. Here we aim to elucidate the bio-distribution of PSP and PAP in animal models of sepsis and in healthy humans.
PSP and PAP responded to remote lesions in rats although the pancreatic response was much more pronounced than the intestinal. Tissue distribution of PSP demonstrated a 100-fold higher content in the pancreas compared to any other organ while PAP was most abundant in the small intestine. Both proteins responded to CLP or sham operation in the pancreas. PSP also increased in the intestine during CLP. The distribution of PSP and PAP in human tissue mirrored the distribution in the murine models.
Distribution of PSP and PAP was visualized by immunohistochemistry. Rats and mice underwent midline laparotomies followed by mobilization of tissue and incision of the pancreatic duct or duodenum. Standard cecum-ligation-puncture (CLP) procedures or sham laparotomies were performed. Human tissue extracts were analyzed for PSP and PAP.
The pancreas reacts to remote lesions and septic insults in mice and rats with increased PSP synthesis, while PAP is selectively responsive to septic events. Furthermore, our results suggest that serum PSP in septic patients is predominantly derived through an acute phase response of the pancreas
Single or combined ablation of peripheral serotonin and p21 limit adipose tissue expansion and metabolic alterations in early adulthood in mice fed a normocaloric diet
Identifying the fundamental molecular factors that drive weight gain even in the absence of hypercaloric food intake, is crucial to enable development of novel treatments for the global pandemic of obesity. Here we investigated both adipose tissue-specific and systemic events that underlie the physiological weight gain occurring during early adulthood in mice fed a normocaloric diet. In addition, we used three different genetic models to identify molecular factors that promote physiological weight gain during normocaloric and hypercaloric diets. We demonstrated that normal physiological weight gain was accompanied by an increase in adipose tissue mass and the presence of cellular and metabolic signatures typically found during obesity, including adipocyte hypertrophy, macrophage recruitment into visceral fat and perturbed glucose metabolism. At the molecular level, this was associated with an increase in adipose tissue tryptophan hydroxylase 1 (Tph1) transcripts, the key enzyme responsible for the synthesis of peripheral serotonin. Genetic inactivation of Tph1 was sufficient to limit adipose tissue expansion and associated metabolic alterations. Mechanistically, we discovered that Tph1 inactivation resulted in down-regulation of cyclin-dependent kinase inhibitor p21Waf1/Cip1 expression. Single or double ablation of Tph1 and p21 were equally effective in preventing adipocyte expansion and systemic perturbation of glucose metabolism, upon both normocaloric and hypercaloric diets. Our results suggest that serotonin and p21 act as a central molecular determinant of weight gain and associated metabolic alterations, and highlights the potential of targeting these molecules as a pharmacologic approach to prevent the development of obesity
Electronic structure of hydrothermally synthesized single crystal U0.22Th0.78O2
Single crystals of ThO2, UO2, and their solid solutions, UxTh1–xO2, have been obtained through various hydrothermal growth conditions. This technique offers the better of two other growth processes: (i) single crystal purity as by photochemical growth of nanocrystals; and (ii) large/bulk sizes as obtained by the arc melt method. The band gap of the UxTh1–xO2 single crystal solid solution, along with the luminescence transition, have been characterized. The occupied and unoccupied structures are determined using ultraviolet and inverse photoemission spectroscopy and the electronic band gap was measured to be 3–4 eV. The strain of incorporating U into the ThO2 is analyzed through Vegard’s law. In this crystal there are defect and impurity sites, likely arising from the kinetic growth process, giving rise to a similar yet slightly different optical gap evident with cathodoluminescence spectroscopy. There is a major luminescence feature spanning the range from 3.18 to 4.96 eV (250–390 nm) with a maximum at 4.09 eV (303 nm), corresponding with the measured electronic band gap. In this paper, the electronic properties of a solid solution U0.22Th0.78O2 are measured and interpreted compared to the pure actinide oxides, ThO2 and UO2
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