2,731 research outputs found
Motor brush wear measured with strain gages
Balanced bridge circuit, supplied with low-voltage direct current and connected to a readout device, measures remaining brush material, rate of brush wear, armature runout, and brush signature
Polymorphisms of the acid sensing histidine kinase gene arsS in Helicobacter pylori populations from anatomically distinct gastric sites
Phase variation is frequently utilized by bacterial species to affect gene expression such that phenotypic variants are maintained within populations, ensuring survival as environmental or host conditions change. Unusual among Helicobacter pylori phase variable or contingency genes is arsS, encoding a sensory histidine kinase involved in the acid acclimation of the organism. The presence of a 3\u27 homopolymeric cytosine tract of variable length in arsS among Helicobacter pylori strains allows for the expression of various functional ArsS isoforms, differing in carboxy-terminal protein domains. In this study, we analyzed this 3\u27 arsS region via amplified fragment length polymorphism (AFLP) and sequencing analyses for H. pylori populations from 3 different gastric sites of 12 patients. Our data indicate the presence of multiple arsS alleles within each population of H. pylori derived from the gastric antrum, cardia, or corpus of these patients. We also show that H. pylori, derived from the same anatomical site and patient, are predicted to express multiple ArsS isoforms in each population investigated. Furthermore, we identify a polymorphic deletion within arsS that generates another alternate ArsS C-terminal end. These findings suggest that four C-terminal variations of ArsS adds to the complexity of the ArsRS acid adaptation mechanism as a whole and may influence the ability of H. pylori to persist in the gastric niche for decades. (c) 2012 Elsevier Ltd. All rights reserved
The GALFA-HI Compact Cloud Catalog
We present a catalog of 1964 isolated, compact neutral hydrogen clouds from
the Galactic Arecibo L-Band Feed Array Survey Data Release One (GALFA-HI DR1).
The clouds were identified by a custom machine-vision algorithm utilizing
Difference of Gaussian kernels to search for clouds smaller than 20'. The
clouds have velocities typically between |VLSR| = 20-400 km/s, linewidths of
2.5-35 km/s, and column densities ranging from 1 - 35 x 10^18 cm^-2. The
distances to the clouds in this catalog may cover several orders of magnitude,
so the masses may range from less than a Solar mass for clouds within the
Galactic disc, to greater than 10^4 Solar Masses for HVCs at the tip of the
Magellanic Stream. To search for trends, we separate the catalog into five
populations based on position, velocity, and linewidth: high velocity clouds
(HVCs); galaxy candidates; cold low velocity clouds (LVCs); warm, low
positive-velocity clouds in the third Galactic Quadrant; and the remaining warm
LVCs. The observed HVCs are found to be associated with previously-identified
HVC complexes. We do not observe a large population of isolated clouds at high
velocities as some models predict. We see evidence for distinct histories at
low velocities in detecting populations of clouds corotating with the Galactic
disc and a set of clouds that is not corotating.Comment: 34 Pages, 9 Figures, published in ApJ (2012, ApJ, 758, 44), this
version has the corrected fluxes and corresponding flux histogram and masse
Building a Strategy for Marketing Minnesota's Secondary Materials. Executive Summary: A Blueprint for Action.
The results of the December 1989 workshop on developing markets for secondary (recycled) materials are summarized here. Three major impediments to the use of secondary materials are identified. Five major actions to overcome these impediments are listed. Strategies for marketing paper, plastics, glass, and metals are outlined.Funded it part by a grant from the Northwest Area Foundation
Building a Strategy for Marketing Minnesota's Secondary Materials. Volume II: A Blueprint for Action.
A two-day workshop on developing markets for secondary (recycled) materials was held in December 1989. Thirty-five people came from industry, government, and the academic and nonprofit communities. Some were key decision-makers in industry and state government. The assessments they made about factors inhibiting markets for recycled paper, plastics, glass, and metals are presented here along with the strategies they developed to build up these markets. The results are summarized in a CURA Reporter article in July 1990.Funded in part by a grant from the Northwest Area Foundation
Building a Strategy for Marketing Minnesota's Secondary Materials.
This report was prepared as part of a project designed to explore strategies for marketing secondary materials diverted from the waste streams in Minnesota and other midwestern states. The report provides an introduction to the topic, pulls together existing information on Minnesota's secondary materials and their markets, identified impediments to full market utilization of these materials, outlines options for overcoming these barriers, and reviews state actions in this regard.Funded in part by a grant from the Northwest Area Foundation
Building a Strategy for Marketing Minnesota's Secondary Materials. Volume I: Market Status Report.
Over the twenty years from 1970 to 1990 our nation had almost doubled the amount of solid waste it generates. Recycling part of the waste is increasingly a part of government strategy for coping with the growing volume of garbage. Finding markets for secondary materials such as paper, plastics, glass, and metals has become a major concern. This volume, prepared for a two-day workshop in December 1989, presents background on Minnesota's secondary materials, their markets, what is preventing the full use of these materials, and how such obstacles might be overcome. State actions to encourage markets for these secondary materials are reviewed. While the report focuses on Minnesota, much of it is relevant to the Midwest as a whole. A CURA Reporter article in July 1990 summarizes this study.Funded in part by a grant from the Northwest Area Foundation
Ongoing Galactic Accretion: Simulations and Observations of Condensed Gas in Hot Halos
Ongoing accretion onto galactic disks has been recently theorized to progress
via the unstable cooling of the baryonic halo into condensed clouds. These
clouds have been identified as analogous to the High-Velocity Clouds (HVCs)
observed in HI in our Galaxy. Here we compare the distribution of HVCs observed
around our own Galaxy and extra-planar gas around the Andromeda galaxy to these
possible HVC analogs in a simulation of galaxy formation that naturally
generates these condensed clouds. We find a very good correspondence between
these observations and the simulation, in terms of number, angular size,
velocity distribution, overall flux and flux distribution of the clouds. We
show that condensed cloud accretion only accounts for ~ 0.2 M_solar / year of
the current overall Galactic accretion in the simulations. We also find that
the simulated halo clouds accelerate and become more massive as they fall
toward the disk. The parameter space of the simulated clouds is consistent with
all of the observed HVC complexes that have distance constraints, except the
Magellanic Stream which is known to have a different origin. We also find that
nearly half of these simulated halo clouds would be indistinguishable from
lower-velocity gas and that this effect is strongest further from the disk of
the galaxy, thus indicating a possible missing population of HVCs. These
results indicate that the majority of HVCs are consistent with being infalling,
condensed clouds that are a remnant of Galaxy formation.Comment: 10 pages, 6 figures, ApJ Accepted. Some changes to techniqu
Vaginal bleeding in children: A retrospective audit at a tertiary paediatric gynaecology service
Aim: The aim of this study was to describe the clinical features and investigations of vaginal bleeding in prepubertal children.
Methods: We performed a retrospective case series of children under the age of 10 who presented with vaginal bleeding to our institution between 2018 and 2019.
Results: There were 32 cases identified during the timeframe, with a mean age of 5.5 years (standard deviation 3.2 years, range 5.5 days to 9.6 years). Vulvovaginitis was the most common diagnosis (n = 12, 37.5%), followed by precocious puberty (n = 5, 15.6%). Uncommon but serious causes were vaginal rhabdomyosarcoma (n = 1), and sexual abuse (one patient presenting with gonorrhoea and one with a non-accidental injury). Vaginoscopy was performed in nine patients (28.1%) for various reasons, and a vaginal foreign body was identified in two patients (6.3%). All the patients who had a serious cause of bleeding (neoplasm or sexual assault) or who required specific treatment (precocious puberty, lichen sclerosus, urethral prolapse) presented with red flags on history and/or examination: recurrent episodes of vaginal bleeding, heavy bleeding, associated general symptoms (poor feeding and growth), presence of thelarche, abdominal mass, associated profuse vaginal discharge and abnormal genital examination (skin changes, urethral prolapse or protruding mass from the vagina).
Conclusions: A thorough history-taking and clinical examination aiming at identifying red flags may help to discriminate between benign causes of vaginal bleeding, where no further investigations are indicated, and alternative diagnoses with a poor outcome and/or requiring specific treatment and additional investigations
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