2,464 research outputs found
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Development of a 3D coculture system to study adipocyte and lymph node cell interactions
We have developed a long term 3-dimensional coculture system with adipocytes and lymph node
cells for the purpose of investigating interactions between these cells in vitro. Present experimental work with the culture system is aimed at introducing lymph node cells, in proportions similar to those found in intact lymph nodes, among differentiated adipocytes and observing interactions and the establishment of a spatial relationship between them. Co-cultures will be used to investigate the lymph node adipocyte interactions following immune stimulation (lipopolysaccharide treatment) measuring production of inflammatory mediators (cytokines) and lipolytic activity
The Role of Adipokines in Understanding the Associations between Obesity and Depression
Objective. Two major causes of disability, major depression and obesity, share overlapping psychosocial and pathophysiological etiologies. Studies are now focused on biological mechanisms linking the two illnesses, and there is interest in the role that adipokines may have in mediating the association between obesity and depression. We reviewed the literature to look at what is currently known about this association, focusing on the adipokines leptin, adiponectin, and resistin. Methods. A MEDLINE search, citing articles from 1966 onward, supplemented by a review of bibliographies, was conducted to identify relevant studies. Results. This paper identified plausible pathways underlying a link between adipokines and depression. Only a few studies have yet been conducted specifically examining these biomarkers in patients with depression, but the results are intriguing. Conclusion. This paper is one of the first to examine the association between adipokines and depression. It provides an overview of the physiological role of adipokines and summarizes the data suggesting that they may be dysregulated in major depression. This area of research may become increasingly important as new treatment strategies are developed
Stellar Activity and its Implications for Exoplanet Detection on GJ 176
We present an in-depth analysis of stellar activity and its effects on radial
velocity (RV) for the M2 dwarf GJ 176 based on spectra taken over 10 years from
the High Resolution Spectrograph on the Hobby-Eberly Telescope. These data are
supplemented with spectra from previous observations with the HIRES and HARPS
spectrographs, and V- and R-band photometry taken over 6 years at the Dyer and
Fairborn observatories. Previous studies of GJ 176 revealed a super-Earth
exoplanet in an 8.8-day orbit. However, the velocities of this star are also
known to be contaminated by activity, particularly at the 39-day stellar
rotation period. We have examined the magnetic activity of GJ 176 using the
sodium I D lines, which have been shown to be a sensitive activity tracer in
cool stars. In addition to rotational modulation, we see evidence of a
long-term trend in our Na I D index, which may be part of a long-period
activity cycle. The sodium index is well correlated with our RVs, and we show
that this activity trend drives a corresponding slope in RV. Interestingly, the
rotation signal remains in phase in photometry, but not in the spectral
activity indicators. We interpret this phenomenon as the result of one or more
large spot complexes or active regions which dominate the photometric
variability, while the spectral indices are driven by the overall magnetic
activity across the stellar surface. In light of these results, we discuss the
potential for correcting activity signals in the RVs of M dwarfs.Comment: Accepted for publication in Ap
Searching for the expelled hydrogen envelope in Type I supernovae via late-time H-alpha emission
We report the first results from our long-term observational survey aimed at
discovering late-time interaction between the ejecta of hydrogen-poor Type I
supernovae and the hydrogen-rich envelope expelled from the progenitor star
several decades/centuries before explosion. The expelled envelope, moving with
a velocity of ~10 -- 100 km s, is expected to be caught up by the
fast-moving SN ejecta several years/decades after explosion depending on the
history of the mass-loss process acting in the progenitor star prior to
explosion. The collision between the SN ejecta and the circumstellar envelope
results in net emission in the Balmer-lines, especially in H-alpha. We look for
signs of late-time H-alpha emission in older Type Ia/Ibc/IIb SNe having
hydrogen-poor ejecta, via narrow-band imaging. Continuum-subtracted H-alpha
emission has been detected for 13 point sources: 9 SN Ibc, 1 SN IIb and 3 SN Ia
events. Thirty-eight SN sites were observed on at least two epochs, from which
three objects (SN 1985F, SN 2005kl, SN 2012fh) showed significant temporal
variation in the strength of their H-alpha emission in our DIAFI data. This
suggests that the variable emission is probably not due to nearby H II regions
unassociated with the SN, and hence is an important additional hint that
ejecta-CSM interaction may take place in these systems. Moreover, we
successfully detected the late-time H-alpha emission from the Type Ib SN 2014C,
which was recently discovered as a strongly interacting SN in various (radio,
infrared, optical and X-ray) bands.Comment: 8 pages, 7 figures, accepted in Ap
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Material-based Stratification
A simple probability model was applied to detection sampling in a room or space in which different surface materials are present. The model assesses the overall detection capability when the sampling and analytical methods have different performance properties for the different materials. The results suggest that some common sampling strategies may not be ideal. In particular: (1) In a single room or area that includes different surface types with different detection properties, do not use a single sampling grid with a common spacing throughout. (2) If it is known or strongly suspected that one material has better detection properties than the other, place all samples on that material. (3) When it is completely unknown which material has the better detection properties, allocate the samples equally between them
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Beryllium Health and Safety Committee Data Reporting Task Force
On December 8, 1999, the Department of Energy (DOE) published Title 10 CFR 850 (hereafter referred to as the Rule) to establish a chronic beryllium disease prevention program (CBDPP) to: {sm_bullet} reduce the number of workers currently exposed to beryllium in the course of their work at DOE facilities managed by DOE or its contractors, {sm_bullet} minimize the levels of, and potential for, expos exposure to beryllium, and {sm_bullet} establish medical surveillance requirements to ensure early detection of the disease
The Pinhole/Occulter Facility
A large occulting system in space can be used for high resolution X-ray observations and for large aperture coronagraphic observations in visible and UV light. The X-ray observations can combine high angular resolution in hand (10 keV) X-radiation with the high sensitivity of a multiple pinhole camera, and can permit sensitive observations of bremsstrahlung from nonthermal particles in the corona. The large aperture coronagraphs have two major advantages: high angular resolution and good photon collection. This will permit observations of small scale structures in the corona for the first time and will give sufficient counting rates above the coronal background rates for sensitive diagnostic analysis of intensities and line profiles for coronal structures in the solar wind acceleration region. The technical basis for performing observations with a large occulting system in these three wavelength ranges is described as well as a pinhole/occulter facility presently being considered for Spacelab. Some indications about future developments are included
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