1,288 research outputs found
A Review of the Pathophysiology and Novel Treatments for Erectile Dysfunction
Erectile dysfunction (ED) affects up to 50% of men between the ages of 40 and 70. Treatment with PDE-5 inhibitors is effective in the majority of men with ED. However, PDE-5 inhibitors are not effective when levels of nitric oxide (NO), the principle mediator of erection, are low. The pharmacologic actions of three new potential treatments for ED are discussed in this paper: (1) sGC stimulators/activators, (2) Rho-kinase inhibitors, and (3) sodium nitrite
Evaluating Net-Zero Energy Houses from the U.S. Department of Energy Solar Decathlon 2011
The Solar Decathlon is a two year, international project where university students compete to design, build, and test energy-efficient, net-zero homes. By definition, net-zero energy houses annually produce as much electricity as they consume. The 2011 Solar Decathlon, held in Washington D.C., had 19 university teams from around the world.
Unfortunately, many past Solar Decathlon houses have traditionally been very costly. However, the 2011 Solar Decathlon was the first competition to have an affordability contest. The affordability contest required each home to be valued under an estimated builder’s cost of $250,000, forcing the teams to select economically feasible solutions for creating net zero energy houses, finding super-efficient, solar- powered, and affordable houses can be done by evaluating the contests associated with the Solar Decathlon 2011.
The main cost-effective and energy saving components were discovered by researching final competition scoring of each specific contest. Heat pump water heaters, properly sized photovoltaic arrays, and HVAC systems with proper dehumidification were the main findings of this research, fortunately, all of these findings can immediately be implemented into the design of net-zero energy housing with off-the-shelf products
MultiFit: a web server for fitting multiple protein structures into their electron microscopy density map
Advances in electron microscopy (EM) allow for structure determination of large biological assemblies at increasingly higher resolutions. A key step in this process is fitting multiple component structures into an EM-derived density map of their assembly. Here, we describe a web server for this task. The server takes as input a set of protein structures in the PDB format and an EM density map in the MRC format. The output is an ensemble of models ranked by their quality of fit to the density map. The models can be viewed online or downloaded from the website. The service is available at; http://salilab.org/multifit/ and http://bioinfo3d.cs.tau.ac.il/
Weight-loss strategies of South African female university students and comparison of weight management-related characteristics between dieters and non-dieters
Abstract Background Female university students are at risk for weight gain and use of inappropriate weight-loss strategies. By gaining a greater understanding of the weight-loss strategies used by and weight management related characteristics of these students, effective weight management interventions for this vulnerable group can be developed. Methods Two hundred and fifty female students from South Africa universities, aged 18–25 years, participated in this cross-sectional study; 162 attempted weight loss during the year preceding the study (dieters) and 88 were non-dieters. Weight and height were measured and BMI (kg/m 2 ) computed. A self-administered questionnaire was used to record all other variables. Weight loss strategies were described for dieters and compared between BMI groups within the dieters group. Weight management related characteristics were compared between dieters and non-dieters. Statistical tests included Pearson Chi-square test, independent samples t-test or Mann-Whitney U test (depending on distribution of the data). Predictors for a higher BMI and being overweight/obese (BMI ≥25 kg/m 2 ) were identified using regression models. Results Healthy weight-loss strategies included increased exercise and fruit/vegetable intake and decreased intake of sugar and fat containing items; unhealthy methods included eating little food and skipping meals; and extreme weight loss strategies included laxatives and vomiting. The most commonly used weight-loss product was Herbex. Dieters were characterized by a higher BMI, overestimation of their weight (especially normal weight students), dissatisfaction with weight and select body parts, higher intake of breakfast and healthy foods, lower intake of unhealthy foods, higher levels of vigorous physical activity, higher use of select informal weight-loss information sources and experiencing more pressure to lose weight from mothers, siblings and friends. Predictors of higher BMI and/or increased risk for BMI ≥25 included weight-loss attempt during the past year, race, dissatisfaction with waist, perception of currently being “chubby,” and higher frequencies of intake of a snack and fatty foods. Conclusion Attempting weight-loss is common among female students and predicts BMI. Healthy (mainly), unhealthy and extreme weight loss methods are used. Dieters are characterized by a less realistic body image, lower body satisfaction, higher pressure to lose weight, use of informal weight-management information and a healthier life-style
Nothing to hide: An X-ray survey for young stellar objects in the Pipe Nebula
We have previously analyzed sensitive mid-infrared observations to establish
that the Pipe Nebula has a very low star-formation efficiency. That study
focused on YSOs with excess infrared emission (i.e, protostars and pre-main
sequence stars with disks), however, and could have missed a population of more
evolved pre-main sequence stars or Class III objects (i.e., young stars with
dissipated disks that no longer show excess infrared emission). Evolved
pre-main sequence stars are X-ray bright, so we have used ROSAT All-Sky Survey
data to search for diskless pre-main sequence stars throughout the Pipe Nebula.
We have also analyzed archival XMM-Newton observations of three prominent areas
within the Pipe: Barnard 59, containing a known cluster of young stellar
objects; Barnard 68, a dense core that has yet to form stars; and the Pipe
molecular ring, a high-extinction region in the bowl of the Pipe. We
additionally characterize the X-ray properties of YSOs in Barnard 59. The ROSAT
and XMM-Newton data provide no indication of a significant population of more
evolved pre-main sequence stars within the Pipe, reinforcing our previous
measurement of the Pipe's very low star formation efficiency.Comment: Accepted for publication in Ap
A catalogue of ULX coincidences with FIRST radio sources
We search for ultra luminous X-ray source (ULXs) radio counterparts located
in nearby galaxies in order to constrain their physical nature. Our work is
based on a systematic cross-identification of the most recent and extensive
available ULX catalogues and archival radio data. A catalogue of 70 positional
coincidences is reported. Most of them are located within the galaxy nucleus.
Among them, we find 11 new cases of non-nuclear ULX sources with possibly
associated radio emission.Comment: Accepted for publication in A&A; 17 pages, 9 figure
The Hubble Legacy Archive NICMOS Grism Data
The Hubble Legacy Archive (HLA) aims to create calibrated science data from
the Hubble Space Telescope archive and make them accessible via user-friendly
and Virtual Observatory (VO) compatible interfaces. It is a collaboration
between the Space Telescope Science Institute (STScI), the Canadian Astronomy
Data Centre (CADC) and the Space Telescope - European Coordinating Facility
(ST-ECF). Data produced by the Hubble Space Telescope (HST) instruments with
slitless spectroscopy modes are among the most difficult to extract and
exploit. As part of the HLA project, the ST-ECF aims to provide calibrated
spectra for objects observed with these HST slitless modes. In this paper, we
present the HLA NICMOS G141 grism spectra. We describe in detail the
calibration, data reduction and spectrum extraction methods used to produce the
extracted spectra. The quality of the extracted spectra and associated direct
images is demonstrated through comparison with near-IR imaging catalogues and
existing near-IR spectroscopy. The output data products and their associated
metadata are publicly available through a web form at http://hla.stecf.org and
via VO interfaces. In total, 2470 spectra of 1923 unique targets are included
in the current release.Comment: 18 pages, 21 figures, accepted for publication in Astronomy &
Astrophysic
The Second-Generation Guide Star Catalog: Description and Properties
The GSC-II is an all-sky database of objects derived from the uncompressed
DSS that the STScI has created from the Palomar and UK Schmidt survey plates
and made available to the community. Like its predecessor (GSC-I), the GSC-II
was primarily created to provide guide star information and observation
planning support for HST. This version, however, is already employed at some of
the ground-based new-technology telescopes such as GEMINI, VLT, and TNG, and
will also be used to provide support for the JWST and Gaia space missions as
well as LAMOST, one of the major ongoing scientific projects in China. Two
catalogs have already been extracted from the GSC-II database and released to
the astronomical community. A magnitude-limited (R=18.0) version, GSC2.2, was
distributed soon after its production in 2001, while the GSC2.3 release has
been available for general access since 2007.
The GSC2.3 catalog described in this paper contains astrometry, photometry,
and classification for 945,592,683 objects down to the magnitude limit of the
plates. Positions are tied to the ICRS; for stellar sources, the all-sky
average absolute error per coordinate ranges from 0.2" to 0.28" depending on
magnitude. When dealing with extended objects, astrometric errors are 20% worse
in the case of galaxies and approximately a factor of 2 worse for blended
images. Stellar photometry is determined to 0.13-0.22 mag as a function of
magnitude and photographic passbands (B,R,I). Outside of the galactic plane,
stellar classification is reliable to at least 90% confidence for magnitudes
brighter than R=19.5, and the catalog is complete to R=20.Comment: 52 pages, 33 figures, to be published in AJ August 200
Pictor A (PKS 0518-45) - From Nucleus to Lobes
We present radio and optical imaging and kinematic data for the radio galaxy
Pictor A, including HST continuum and [OIII], emission-line images (at a
resolution of 25 - 100 mas) and ground-based imaging and spectroscopy (at a
resolution of ~ 1.5". The radio data include 3 cm Australia Telescope images of
the core, at a resolution comparable to that of the optical, ground-based
images, and a VLBI image of a jet in the compact core (at a resolution of 2 -
25 mas), which seems to align with a continuum ``jet'' found in the HST images.
The core radio jet, the HST optical continuum ``jet'', and the NW H-alpha
filaments all appear to point toward the optical-synchrotron hot-spot in the NW
lobe of this object and are associated with a disrupted velocity field in the
extended ionized gas. The ground-based spectra which cover this trajectory also
yield line ratios for the ionized gas which have anomalously low [NII] (6564),
suggesting either a complex, clumpy structure in the gas with a higher
cloud-covering factor at larger radii and with denser clouds than is found in
the nuclear regions of most NLRG and Seyfert 2 galaxies, or some other,
unmodeled, mechanism for the emergent spectrum from this region. The H-alpha
emission-line filaments to the N appear to be associated with a 3 cm radio
continuum knot which lies in a gap in the filaments ~ 4" from the nucleus.
Altogether, the data in this paper provide good circumstantial evidence for
non-disruptive redirection of a radio jet by interstellar gas clouds in the
host galaxy.Comment: 19 pages, 6 ps.gz fig pages, to appear in the Ap.J. Supp
- …