Catalog Matching with Astrometric Correction and its Application to the Hubble Legacy Archive

Object cross-identification in multiple observations is often complicated by the uncertainties in their astrometric calibration. Due to the lack of standard reference objects, an image with a small field of view can have significantly larger errors in its absolute positioning than the relative precision of the detected sources within. We present a new general solution for the relative astrometry that quickly refines the World Coordinate System of overlapping fields. The efficiency is obtained through the use of infinitesimal 3-D rotations on the celestial sphere, which do not involve trigonometric functions. They also enable an analytic solution to an important step in making the astrometric corrections. In cases with many overlapping images, the correct identification of detections that match together across different images is difficult to determine. We describe a new greedy Bayesian approach for selecting the best object matches across a large number of overlapping images. The methods are developed and demonstrated on the Hubble Legacy Archive, one of the most challenging data sets today. We describe a novel catalog compiled from many Hubble Space Telescope observations, where the detections are combined into a searchable collection of matches that link the individual detections. The matches provide descriptions of astronomical objects involving multiple wavelengths and epochs. High relative positional accuracy of objects is achieved across the Hubble images, often sub-pixel precision in the order of just a few milli-arcseconds. The result is a reliable set of high-quality associations that are publicly available online.Comment: 9 pages, 9 figures, accepted for publication in the Astrophysical Journa

Use of Fluorescence Microscopy in an Assay of Sperm Density for the Gorgonian Coral, Plexaura kuna

The density of sperm in the water column during the broadcast spawning events of marine invertebrates is often undetermined or reported in terms of fertilization potential. The density of sperm during such events can be determined by directly counting numbers of spermatozoa using a modification of the acridine orange direct count (AODC) technique for enumerating bacteria. A number of variables in the handling and processing of samples may bias estimates. Sample collection in glass and rapid fixation and filtration are necessary for reproducible estimates. Once filtered, samples are stable for many months, and counts on filters that were poorly stained in the field can be enhanced by additional staining with 4\u276-diamidino-2-phynlindole (DAPI). The AODC technique was employed to examine the effects of distance from a male colony on density of sperm for the gorgonian coral Plexaura kuna. In situ sperm densities ranged from 0 to 1,000 sperm/ml. Sperm densities in 18 l aquaria containing 20 cm long P. kuna explants reached 100,000 sperm/ml

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

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/

XMM-Newton observation of PSR B2224+65 and its jet

We have investigated the pulsar PSR B2224+65 and its X-ray jet with XMM-Newton. Apart from the long X-ray jet which is almost perpendicular to the direction of proper motion, a putative extended feature at the pulsar position, which oriented in the opposite direction of the proper motion, is also suggested by this deep X-ray imaging. Non-detection of any coherent X-ray pulsation disfavors the magnetospheric origin of the X-rays observed from the position of PSR B2224+65 and hence suggest that the interpretation of pulsar wind nebula is more viable. We have also probed the origin of PSR B2224+65 and identified a runaway star, which possibly originated from the Cygnus OB9 association, as a candidate for the former binary companion of the neutron star's progenitor.Comment: 24 pages, 8 figures, 3 tables, accepted for publication in Ap

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

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

Knowledge Regarding Sexual Abuse of Selected University Students of Dhaka City

Introduction: Sexual harassment involves an assortment of coercive behaviors, including physical force, intimidation, and various forms of compulsion, including verbal harassment and forced penetration [1]. Sexual abuse can happen to both men and women. In the United Kingdom(UK), the problem of child sexual abuse (CSA) has epidemic proportions and is a global public health issue [2]. 53,874 incidents were reported under the 2012 Protection of Children from Sexual Offences Act as of 2021 [3]. to their ignorance about puberty, sexuality, and fundamental human biological changes, adolescents have a very difficult time addressing their SRH demands. These underlying causes contribute to high rates of teen pregnancy, STIs, sexual assault, poor negotiating skills, forced marriage, and high fertility rates [4]. Methods: The study used a quantitative technique and a descriptive cross-sectional design. Students at Jahangir Nagar University and the American International University of Bangladesh were the intended target group. Jahangir Nagar University and American International University of Bangladesh served as the study locations. The six-month trial period ran from January 2022 through June 2022. For this investigation, primary sources of data were used. The study unit was the individual student. Non-probability (purposive) sampling techniques were used for the investigation. Results: The majority of survey participants (N=81) 62.2% were aged between 19 and 21 years old, and there was a statistically significant difference in age between students at public and private universities. None of our study participants suffered from any kind of sexual abuse, though they mentioned hearing about it. Regarding the view of sexual abuse, public universities 23% of those polled claimed sexual abuse as a justification for sharing inappropriate photos. At private universities, the response rate for crude jokes is 32.5%. Only the least number of public (2%) and private university (10%) students took part in sexual abuse-related awareness or training programs. Regarding the rights to receive training for prevention and safeguarding from sexual abuse, only 28% of the public and 40% of the private university students replied in affirmative. Conclusion: Sexual harassment is a sensitive issue, though due to various reasons, the rate of reporting and providing justice to the victims is delayed all over the world including Bangladesh. There social, religious, and policy lacking in this context