2,818 research outputs found
Ontology Summit 2008 Communiqué: Towards an open ontology repository
Each annual Ontology Summit initiative makes a statement appropriate to each Summits theme as part of our general advocacy designed to bring ontology science and engineering into the mainstream. The theme this year is "Towards an Open Ontology Repository". This communiqué represents the joint position of those who were engaged in the year's summit discourse on an Open Ontology Repository (OOR) and of those who endorse below. In this discussion, we have agreed that an "ontology repository is a facility where ontologies and related information artifacts can be stored, retrieved and managed."
We believe in the promise of semantic technologies based on logic, databases and the Semantic Web, a Web of exposed data and of interpretations of that data (i.e., of semantics), using common standards. Such technologies enable distinguishable, computable, reusable, and sharable meaning of Web and other artifacts, including data, documents, and services. We also believe that making that vision a reality requires additional supporting resources and these resources should be open, extensible, and provide common services over the ontologies
Microtubule dynamics drive enhanced chromatin motion and mobilize telomeres in response to DNA damage
Chromatin exhibits increased mobility on DNA damage, but the biophysical basis for this behavior remains unknown. To explore the mechanisms that drive DNA damage–induced chromosome mobility, we use single-particle tracking of tagged chromosomal loci during interphase in live yeast cells together with polymer models of chromatin chains. Telomeres become mobilized from sites on the nuclear envelope and the pericentromere expands after exposure to DNA-damaging agents. The magnitude of chromatin mobility induced by a single double-strand break requires active microtubule function. These findings reveal how relaxation of external tethers to the nuclear envelope and internal chromatin–chromatin tethers, together with microtubule dynamics, can mobilize the genome in response to DNA damage
Parents\u27 Goals For ADHD Care In a Clinical Pediatric Sample
Objective. This report describes goals parents have for their children with attention deficit/hyperactivity disorder (ADHD) when coming for a pediatric visit. Method. Data were collected from 441 parents of children presenting to either a primary care pediatric practice or a developmental behavioral pediatric practice. Parents were asked to report their top 1 or 2 goals for improvement for their children, and responses were coded into 17 categories. These categories were further grouped into 7 goal composites and examined in relation to demographic characteristics of the families, office type, and symptomology. Results. Goals related to reducing symptoms of inattention were most common, but goals were heterogeneous in nature. Goals were meaningfully, but modestly, related to symptomology. In several instances, symptoms of comorbid conditions interacted with symptoms of ADHD in relation to specific goals being reported. Conclusions. Parents’ goals extended beyond ADHD symptoms. Pediatricians need an array of resources to address parents’ goals
Centromere Tethering Confines Chromosome Domains
The organization of chromosomes into territories plays an important role in a wide range of cellular processes including gene expression, transcription, and DNA repair. Current understanding has largely excluded the spatio-temporal dynamic fluctuations of the chromatin polymer. We combine in vivo chromatin motion analysis with mathematical modeling to elucidate the physical properties that underlie the formation and fluctuations of territories. Chromosome motion varies in predicted ways along the length of the chromosome, dependent on tethering at the centromere. Detachment of a tether upon inactivation of the centromere results in increased spatial mobility. A confined bead-spring chain tethered at both ends provides a mechanism to generate observed variations in local mobility as a function of distance from the tether. These predictions are realized in experimentally determined higher effective spring constants closer to the centromere. The dynamic fluctuations and territorial organization of chromosomes are, in part, dictated by tethering at the centromere
Three-dimensional modeling of the asymmetric blast wave from the 2006 outburst of RS Ophiuchi: Early X-ray emission
Chandra/HETG observations of the recurrent nova RS Ophiuchi at day 13.9 of
its 2006 outburst reveal a spectrum covering a large range in plasma
temperature and characterized by asymmetric and blue-shifted emission lines. We
investigate the origin of these asymmetries and broadening of emission lines.
We perform 3-D hydrodynamic simulations of the blast wave from the 2006
outburst, propagating through the inhomogeneous CSM. The model takes into
account the thermal conduction (including the effects of heat flux saturation)
and the radiative cooling. From the simulations, we synthesize the X-ray
emission and derive the spectra as they would be observed with Chandra/HETG.
Our model reproduces the observed X-ray emission in a natural way if the CSM in
which the outburst occurred is characterized by an equatorial density
enhancement. Our ``best-fit'' model predicts that most of the early X-ray
emission originates from a small region propagating in the direction
perpendicular to the line-of-sight and localized just behind the interaction
front between the blast wave and the equatorial density enhancement. The model
predicts asymmetric and blue-shifted line profiles remarkably similar to those
observed. These asymmetries are due to substantial X-ray absorption of
red-shifted emission by ejecta material. The comparison of high quality data of
Chandra/HETG with detailed hydrodynamic modeling has allowed us to unveil, for
the first time, the details of the structure emitting in the X-ray band in
early phases of the outburst evolution, contributing to a better understanding
of the physics of interactions between nova blasts and CSM in recurrent novae.
This may have implications for whether or not RS Ophiuchi is a Type Ia SN
progenitor system.Comment: 12 pages, 7 Figures; paper accepted for publication in A&A; the paper
with high-resolution figures can be downloaded at
http://www.astropa.unipa.it/~orlando/PAPERS/rs_oph_nova.pd
On continuous variable quantum algorithms for oracle identification problems
We establish a framework for oracle identification problems in the continuous
variable setting, where the stated problem necessarily is the same as in the
discrete variable case, and continuous variables are manifested through a
continuous representation in an infinite-dimensional Hilbert space. We apply
this formalism to the Deutsch-Jozsa problem and show that, due to an
uncertainty relation between the continuous representation and its
Fourier-transform dual representation, the corresponding Deutsch-Jozsa
algorithm is probabilistic hence forbids an exponential speed-up, contrary to a
previous claim in the literature.Comment: RevTeX4, 15 pages with 10 figure
Pneumonic Tularemia in Rabbits Resembles the Human Disease as Illustrated by Radiographic and Hematological Changes after Infection
Background: Pneumonic tularemia is caused by inhalation of the gram negative bacterium, Francisella tularensis. Because of concerns that tularemia could be used as a bioterrorism agent, vaccines and therapeutics are urgently needed. Animal models of pneumonic tularemia with a pathophysiology similar to the human disease are needed to evaluate the efficacy of these potential medical countermeasures. Principal Findings: Rabbits exposed to aerosols containing Francisella tularensis strain SCHU S4 developed a rapidly progressive fatal pneumonic disease. Clinical signs became evident on the third day after exposure with development of a fever (>40.5°C) and a sharp decline in both food and water intake. Blood samples collected on day 4 found lymphopenia and a decrease in platelet counts coupled with elevations in erythrocyte sedimentation rate, alanine aminotransferase, cholesterol, granulocytes and monocytes. Radiographs demonstrated the development of pneumonia and abnormalities of intestinal gas consistent with ileus. On average, rabbits were moribund 5.1 days after exposure; no rabbits survived exposure at any dose (190-54,000 cfu). Gross evaluation of tissues taken at necropsy showed evidence of pathology in the lungs, spleen, liver, kidney and intestines. Bacterial counts confirmed bacterial dissemination from the lungs to the liver and spleen. Conclusions/Significance: The pathophysiology of pneumonic tularemia in rabbits resembles what has been reported for humans. Rabbits therefore are a relevant model of the human disease caused by type A strains of F. tularensis. © 2011 Reed et al
Nuggets, Pearls, and Vignettes of Master Heart Failure Clinicians
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73696/1/j.1527-5299.2001.00307.x.pd
A qualitative study of carers' experiences of dementia cafes : a place to feel supported and be yourself
Abstract Background Unpaid, informal carers or caregivers play an important role in supporting people living with dementia but the role can be challenging and carers themselves may benefit from support. Alzheimer’s, dementia or memory cafés are one such form of support . These cafés are usually provided in the voluntary sector and are a place where people with dementia and those supporting them, usually family carers, can meet with others in similar situations. Methods Using semi-structured interviews, this qualitative study explored the experiences of 11 carers from five dementia cafés in and around London, England. Results Thematic analysis resulted in the identification of four key themes. Cafés provide a relaxed, welcoming atmosphere where carers can go where they feel supported and accepted. Café attendance often brought a sense of normality to these carers’ lives. Carers and those they care for look forward to going and often enjoy both the activities provided and socialising with others. Other highlighted benefits included peer support from other carers, information provision and support from the volunteer café coordinators. Despite diversity in how the cafés were run and in the activities offered, there were many reported similarities amongst carers in the value ascribed to attending the cafés. Conclusions Dementia cafés appear to be a valuable, perhaps unique form of support for carers giving them brief respite from their caring role. Future research incorporating mixed methods is needed to understand the perspectives of those living with dementia
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