242 research outputs found
Hypervelocity Stars: Predicting the Spectrum of Ejection Velocities
The disruption of binary stars by the tidal field of the black hole in the
Galactic Center can produce the hypervelocity stars observed in the halo. We
use numerical models to simulate the full spectrum of observable velocities of
stars ejected into the halo by this binary disruption process. Our model
includes a range of parameters for binaries with 3-4 M_Solar primaries,
consideration of radial orbits of the ejected stars through an approximate mass
distribution for the Galaxy, and the impact of stellar lifetimes. We calculate
the spectrum of ejection velocities and reproduce previous results for the mean
ejection velocity at the Galactic center. The model predicts that the full
population of ejected stars includes both the hypervelocity stars with
velocities large enough to escape from the Galaxy and a comparable number of
ejected, but bound, stars of the same stellar type. The predicted median speeds
of the population of ejected stars as a function of distance in the halo are
consistent with current observations. Combining the model with the data also
shows that interesting constraints on the properties of binaries in the
Galactic Center and on the mass distribution in the Galaxy can be obtained even
with modest samples of ejected stars.Comment: 26 pages, including 6 figures, accepted for publication in the
Astrophysical Journa
Association of Caldendrin splice isoforms with secretory vesicles in neurohypophyseal axons and the pituitary
AbstractCaldendrin is a neuronal calcium-binding protein, which is highly enriched in the postsynaptic density fraction and exhibits a prominent somato-dendritic distribution in brain. Two additional splice variants derive from the caldendrin gene, which have unrelated N-termini and were previously only detected in the retina. We now show that these isoforms are present in neurohypophyseal axons and on secretory granules of endocrine cells. In light of the described interaction of the Caldendrin C-terminus with Q-type Cav2.1 calcium channels these data suggest that this interaction takes place in neurohypophyseal axons and pituitary cells indicating functions of the short splice variants in triggering Ca2+ transients to a vesicular target interaction
Ocean acidification affects iron speciation during a coastal seawater mesocosm experiment
Rising atmospheric CO2 is acidifying the surface ocean, a process which is expected to greatly influence the chemistry and biology of the future ocean. Following the development of iron-replete phytoplankton blooms in a coastal mesocosm experiment at 350, 700, and 1050 μatm pCO2, we observed significant increases in dissolved iron concentrations, Fe(II) concentrations, and Fe(II) half-life times during and after the peak of blooms in response to CO2 enrichment and concomitant lowering of pH, suggesting increased iron bioavailability. If applicable to the open ocean this may provide a negative feedback mechanism to the rising atmospheric CO2 by stimulating marine primary production
Environmental and land use consequences of replacing milk and beef with plant-based alternatives
MicroRNA-126-3p/5p and Aortic Stiffness in Patients with Turner Syndrome
Background: Turner Syndrome (TS) is a relatively rare X-chromosomal disease with increased cardiovascular morbidity and mortality. This study aimed to identify whether the circulating
miR-126-3p/5p are involved in the pathophysiology of vascular dysfunction in TS. Methods: Using
the RT-qPCR, the abundance levels of miR-126-3p and miR-126-5p were determined in 33 TS patients
and 33 age-matched healthy volunteers (HVs). Vascular screening, including the assessment of blood
pressure, pulse wave velocity, augmentation index, aortic deformation, arterial distensibility, and arterial elastance, was conducted in TS patients and HVs. Results: The abundance levels of miR-126-3p
and miR-126-5p were significantly higher in TS patients compared to HVs (p < 0.0001). Within the TS
cohort, miR-126-3p/5p correlated significantly with aortic deformation (r = 0.47, p = 0.01; r = 0.48,
p < 0.01) and arterial distensibility (r = 0.55, p < 0.01; r = 0.48, p < 0.01). In addition, a significant
negative correlation was demonstrated between miR-126-3p and arterial elastance (r = −0.48, p = 0.01).
The receiver operating characteristic analysis showed that miR-126-3p and miR-126-5p separated the
tested groups with high sensitivity and specificity. Conclusions: The abundance levels of miR-126-3p
and miR-126-5p were significantly higher in TS patients compared to HVs. Within the TS cohort, a lower
abundance level of miR-126-3p and miR-126-5p was linked with a significantly higher aortic stiffness
Literatur-Rundschau
Daniel Meier: Kirche in der Tagespresse (Christian Klenk)Reiner Moltmann: Reinhold Reinen (1894-1969). Ein christlicher Politiker, Journalist und Verleger (Ferdinand Oertel)Mathias Schiltz (Hg.): Festschrift für/Hommage à André Heiderscheid (Michael Schmolke)Ulrich Saxer: Politik als Unterhaltung (Wolfgang R. Langenbucher)Siegtried Weischenberg/Maja Malik/Armin Scholl: Die Souffleure der Mediengesellschaft (Ralf Hohlfeld)Franzisca Gottwald: Gesundheitsöffentlichkeit (Eckart Klaus Roloffj
Insights from circulating microRNAs in cardiovascular entities in turner syndrome patients
Background
Turner syndrome (TS) is a chromosomal disorder, in which a female is partially or entirely missing one of the two X chromosomes, with a prevalence of 1:2500 live female births. The present study aims to identify a circulating microRNA (miRNA) signature for TS patients with and without congenital heart disease (CHD).
Methods
Microarray platform interrogating 2549 miRNAs were used to detect the miRNA abundance levels in the blood of 33 TS patients and 14 age-matched healthy volunteer controls (HVs). The differentially abundant miRNAs between the two groups were further validated by RT-qPCR.
Results
We identified 60 differentially abundant miRNA in the blood of TS patients compared to HVs, from which, 41 and 19 miRNAs showed a higher and a lower abundance levels in TS patients compared to HVs, respectively. RT-qPCR confirmed the significantly higher abundance levels of eight miRNAs namely miR-374b-5p, miR-199a-5p, miR-340-3p, miR-125b-5p, miR-30e-3p, miR-126-3p, miR-5695, and miR-26b-5p in TS patients as compared with the HVs. The abundance level of miR-5695 was higher in TS patients displaying CHD as compared to TS patients without CHD (p = 0.0265; log2-fold change 1.99); whereas, the abundance level of miR-126-3p was lower in TS patients with congenital aortic valve disease (AVD) compared to TS patients without BAV (p = 0.0139, log2-fold change 1.52). The clinical feature statistics revealed that miR-126-3p had a significant correlation with sinotubular junction Z-score (r = 0.42; p = 0.0154).
Conclusion
The identified circulating miRNAs signature for TS patients with manifestations associated with cardiovascular diseases provide new insights into the molecular mechanism of TS that may guide the development of novel diagnostic approaches
Evaluating Depressive Symptoms in Schizophrenia: A Psychometric Comparison of the Calgary Depression Scale for Schizophrenia and the Hamilton Depression Rating Scale
Background: The aim of this study was to compare two measures of depression in patients with schizophrenia and schizophrenia spectrum disorder, including patients with delusional and schizoaffective disorder, to conclude implications for their application. Sampling and Methods: A total of 278 patients were assessed using the Calgary Depression Scale for Schizophrenia (CDSS) and the Hamilton Depression Rating Scale (HAMD-17). The Positive and Negative Syndrome Scale (PANSS) was also applied. At admission and discharge, a principal component analysis was performed with each depression scale. The two depression rating scales were furthermore compared using correlation and regression analyses. Results: Three factors were revealed for the CDSS and HAMD-17 factor component analysis. A very similar item loading was found for the CDSS at admission and discharge, whereas results of the loadings of the HAMD-17 items were less stable. The first two factors of the CDSS revealed correlations with positive, negative and general psychopathology. In contrast, multiple significant correlations were found for the HAMD-17 factors and the PANSS sub-scores. Multiple regression analyses demonstrated that the HAMD-17 accounted more for the positive and negative symptom domains than the CDSS. Conclusions:The present results suggest that compared to the HAMD-17, the CDSS is a more specific instrument to measure depressive symptoms in schizophrenia and schizophrenia spectrum disorder, especially in acutely ill patients. Copyright (c) 2012 S. Karger AG, Base
Low-dose Decitabine Vs best supportive care in older patients with AML and low blast counts: results of a subgroup analysis of the randomized phase III study 06011 of the EORTC leukemia cooperative group and german MDS study group
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