5,294 research outputs found
Cosmology on a Mesh
An adaptive multi grid approach to simulating the formation of structure from
collisionless dark matter is described. MLAPM (Multi-Level Adaptive Particle
Mesh) is one of the most efficient serial codes available on the cosmological
'market' today. As part of Swinburne University's role in the development of
the Square Kilometer Array, we are implementing hydrodynamics, feedback, and
radiative transfer within the MLAPM adaptive mesh, in order to simulate
baryonic processes relevant to the interstellar and intergalactic media at high
redshift. We will outline our progress to date in applying the existing MLAPM
to a study of the decay of satellite galaxies within massive host potentials.Comment: 3 pages, 2 figures, to appear in the proceedings of "The IGM/Galaxy
Connection - The Distribution of Baryons at z=0", ed. M. Putman & J.
Rosenber
Half-life of the electron-capture decay of 97Ru: Precision measurement shows no temperature dependence
We have measured the half-life of the electron-capture (ec) decay of 97Ru in
a metallic environment, both at low temperature (19K), and also at room
temperature. We find the half-lives at both temperatures to be the same within
0.1%. This demonstrates that a recent claim that the ec decay half-life for 7Be
changes by $0.9% +/- 0.2% under similar circumstances certainly cannot be
generalized to other ec decays. Our results for the half-life of 97Ru,
2.8370(14)d at room temperature and 2.8382(14)d at 19K, are consistent with,
but much more precise than, previous room-temperature measurements. In
addition, we have also measured the half-lives of the beta-emitters 103Ru and
105Rh at both temperatures, and found them also to be unchanged.Comment: 6 pages, 6 figure
CH 3 GHz Observations of the Galactic Center
A 3 3 map of the Galactic Center was made at 9\arcmin resolution
and 10\arcmin spacing in the CH , J=1/2, F=1-1 transition at
3335 MHz. The CH emission shows a velocity extent that is nearly that of the
CO(1-0) line, but the CH line profiles differ markedly from the CO. The 3335
MHz CH transition primarily traces low-density molecular gas and our
observations indicate that the mass of this component within 30 pc of
the Galactic Center is 9 10 M. The CO-H
conversion factor obtained for the low-density gas in the mapped region is
greater than that thought to apply to the dense molecular gas at the Galactic
Center. In addition to tracing the low-density molecular gas at the Galactic
Center, the CH spectra show evidence of emission from molecular clouds along
the line of sight both in the foreground and background. The scale height of
these clouds ranges from 27 - 109 pc, consistent with previous work based on
observations of molecular clouds in the inner Galaxy.Comment: 29 pages, 12 figure
Weaning of immunosuppression in long - Term liver transplant recipients
Seventy-two long-surviving liver transplant recipients were evaluated prospectively, including a baseline allograft biopsy for weaning off of immunosuppression. Thirteen were removed from candidacy because of chronic rejection (n=4), hepatitis (n=2), patient anxiety (n=5), or lack of cooperation by the local physician (n=2). The other 59, aged 12-68 years, had stepwise drug weaning with weekly or biweekly monitoring of liver function tests. Their original diagnoses were PBC (n=9), HCC (n=l), Wilsonâs disease (n=4), hepatitides (n=15), Laennecâs cirrhosis (n=l), biliary atresia (n=16), cystic fibrosis (n=l), hemochromatosis (n=l), hepatic trauma (n=l), alpha-l-antitrypsin deficiency (n=9), and secondary biliary cirrhosis (n=l). Most of the patients had complications of long-term immunosuppression, of which the most significant were renal dysfunction (n=8), squamous cell carcinoma (n=2) or verruca vulgaris of skin (n=9), osteoporosis and/or arthritis (n=12), obesity (n=3), hypertension (n=ll), and opportunistic infections (n=2). When azathioprine was a third drug, it was stopped first. Otherwise, weaning began with prednisone, using the results of corticotropin stimulation testing as a guide. If adrenal insufficiency was diagnosed, patients reduced to <5 mg/day prednisone were considered off of steroids. The baseline agents (azathioprine, cyclospo-rine, or FK506) were then gradually reduced in monthly decrements. Complete weaning was accomplished in 16 patients (27.1%) with 3-19 months drug-free follow-up, is progressing in 28 (47.4%), and failed in 15 (25.4%) without graft losses or demonstrable loss of graft function from the rejections. This and our previous experience with self-weaned and other patients off of immunosuppression indicate that a significant percentage of appropriately selected long-surviving liver recipients can unknowingly achieve drug-free graft acceptance. Such attempts should not be contemplated until 5-10 years posttransplantation and then only with careful case selection, close monitoring, and prompt reinstitution of immunosuppression when necessary. © 1995 by Williams & Wilkins
Patient-focused Websites Related to Stress Urinary Incontinence and Pelvic Organ Prolapse: a DISCERN Quality Analysis
Objective: To evaluate the quality of information presented on English-language websites regarding treatment options for POP and SUI using a validated instrument. Methods: Utilizing the International Urogynecology Association list of continence societies worldwide, faculty nomination and a complementary Google search using the terms âprofessional organizations stress urinary incontinence / pelvic organ prolapseâ English-language, patient-focused websites related to POP and SUI were identified. The websites were evaluated by faculty at an academic medical center, including 4 faculty members of the urogynecology division, 2 urogynecology fellows, 3 urologists, and 1 obstetrician gynecologist. The websites were independently evaluated using the validated DISCERN instrument assessing the reliability and quality of consumer health information.Results: From the IUGA continence societies worldwide list, 47 websites were identified. Five provided patient information in English. Eight additional websites were identified from the Google search or provider nomination. One website provided information only for POP (rectocele), 5 for SUI, and 7 for both. The lowest mean total score for any website was 38.7 and the highest mean total score was 61.5 across all the websites. There were no statistically significant differences in the website mean total scores (p value \u3c0.40 for POP and 0.14 for SUI). For websites covering both topics, POP scores were generally higher than SUI scores, but not statistically significantly different (p value\u3c3.75). The overall quality item scores were also not significantly different (SUI: p\u3c0.923; POP: p \u3c0.813). Missing information most commonly included lack of clear objectives, sources, and information related to the expected outcome of no intervention.Conclusions: Available English-language professional websites written to inform patients about management choices for SUI and POP miss key components of quality patient information
Does the Milky Way have a Maximal Disk?
The Milky Way is often considered to be the best example of a spiral for
which the dark matter not only dominates the outer kinematics, but also plays a
major dynamical role in the inner galaxy: the Galactic disk is therefore said
to be ``sub-maximal.'' This conclusion is important to the understanding of the
evolution of galaxies and the viability of particular dark matter models. The
Galactic evidence rests on a number of structural and kinematic measurements,
many of which have recently been revised. The new constraints indicate not only
that the Galaxy is a more typical member of its class (Sb-Sc spirals) than
previously thought, but also require a re-examination of the question of
whether or not the Milky Way disk is maximal. By applying to the Milky Way the
same definition of ``maximal disk'' that is applied to external galaxies, it is
shown that the new observational constraints are consistent with a Galactic
maximal disk of reasonable . In particular, the local disk column can be
substantially less than the oft-quoted required \Sigma_{\odot} \approx 100
\msolar pc^{-2} - as low as 40 \msolar pc^{-2} in the extreme case - and
still be maximal, in the sense that the dark halo provides negligible rotation
support in the inner Galaxy. This result has possible implications for any
conclusion that rests on assumptions about the potentials of the Galactic disk
or dark halo, and in particular for the interpretation of microlensing results
along both LMC and bulge lines of sight.Comment: Accepted for publication in The Astrophysical Journal. 23
Latex-generated pages, one (new) table, three figures (two new). A few
additions to the bibliography, an expanded discussion, and slight
quantitative changes, none of which affect the conclusion
Pervasiveness of the IQ Rise: A Cross-Temporal Meta-Analysis
Background: Generational IQ gains in the general population (termed the Flynn effect) show an erratic pattern across different nations as well as across different domains of intelligence (fluid vs crystallized). Gains of fluid intelligence in different countries have been subject to extensive research, but less attention was directed towards gains of crystallized intelligence, probably due to evidence from the Anglo-American sphere suggesting only slight gains on this measure. In the present study, development of crystallized intelligence in the German speaking general population is assessed. Methodology/Principal Findings: To investigate whether IQ gains for crystallized intelligence are in progress in Germanspeaking countries, two independent meta-analyses were performed. By means of a cited reference search in ISI Web of Science, all studies citing test manuals and review articles of two widely-used salient measures of crystallized intelligence were obtained. Additionally, the electronic database for German academic theses was searched to identify unpublished studies employing these tests. All studies reporting participants mean IQ or raw scores of at least one of the two measures were included in the present analyses, yielding over 500 studies (.1,000 samples;.45,000 individuals). We found a significant positive association between years of test performance and intelligence (1971â2007) amounting to about 3.5 IQ points per decade. Conclusions/Significance: This study clearly demonstrates that crystallized IQ gains are substantial and of comparabl
Precautionary advice about mobile phones: Public understandings and intended responses
The official published version can be obtained from the link below - Copyright @ Taylor & FrancisThere is a widespread academic and policy debate about public responses to precaution in public health campaigns. This paper explores these issues in relation to the precautionary stance adopted in the UK around the regulation of mobile telecommunications. The aim of the paper is to examine the nature of attitudes to precaution, and the way in which these, along with other relevant variables, relate to the intention to adopt relevant behaviours. The results from an experimental study (n = 173) indicate that people distinguish between two dimensions of precaution: firstly in relation to its value or necessity per se and secondly as anchored to notions of governance. The two variables differentially relate to other variables including trust and uncertainty, and are predictive of intended behaviour change indirectly, through worry about mobile phone risks. Precautionary advice was generally interpreted as causing concern rather than providing reassurance. The results suggest that precaution may be considered a valuable stance but this does not mean that it is seen as good governance or that it will reduce concern. Whilst the discourse of precaution is aimed at reducing concern, it appears that the uptake of relevant behaviours is largely triggered by worry
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