1,119 research outputs found
Preparation of ultracold atom clouds at the shot noise level
We prepare number stabilized ultracold clouds through the real-time analysis
of non-destructive images and the application of feedback. In our experiments,
the atom number is determined by high precision Faraday imaging
with uncertainty below the shot noise level, i.e., . Based on this measurement, feedback is applied to reduce the atom
number to a user-defined target, whereupon a second imaging series probes the
number stabilized cloud. By this method, we show that the atom number in
ultracold clouds can be prepared below the shot noise level.Comment: Main text: 4 Figures, 4 pages. Supplemental Information: 4 figures, 5
page
Clozapine-induced agranulocytosis is associated with rare HLA-DQB1 and HLA-B alleles
Clozapine is a particularly effective antipsychotic medication but its use is curtailed by the risk of clozapine-induced agranulocytosis/granulocytopenia (CIAG), a severe adverse drug reaction occurring in up to 1% of treated individuals. Identifying genetic risk factors for CIAG could enable safer and more widespread use of clozapine. Here we perform the largest and most comprehensive genetic study of CIAG to date by interrogating 163 cases using genomewide genotyping and whole-exome sequencing. We find that two loci in the major histocompatibility complex are independently associated with CIAG: a single amino acid in HLA-DQB1 (126Q) (P = 4.7 x 10(-14), odds ratio (OR) = 0.19, 95% confidence interval (CI) = 0.12-0.29) and an amino acid change in the extracellular binding pocket of HLA-B (158T) (P = 6.4 x 10(-10), OR = 3.3, 95% CI = 2.3-4.9). These associations dovetail with the roles of these genes in immunogenetic phenotypes and adverse drug responses for other medications, and provide insight into the pathophysiology of CIAG
Planning and delivery of intensity modulated bolus electron conformal therapy
PURPOSE: Bolus electron conformal therapy (BECT) is a clinically useful, well-documented, and available technology. The addition of intensity modulation (IM) to BECT reduces volumes of high dose and dose spread in the planning target volume (PTV). This paper demonstrates new techniques for a process that should be suitable for planning and delivering IM-BECT using passive radiotherapy intensity modulation for electrons (PRIME) devices.
METHODS: The IM-BECT planning and delivery process is an addition to the BECT process that includes intensity modulator design, fabrication, and quality assurance. The intensity modulator (PRIME device) is a hexagonal matrix of small island blocks (tungsten pins of varying diameter) placed inside the patient beam-defining collimator (cutout). Its design process determines a desirable intensity-modulated electron beam during the planning process, then determines the island block configuration to deliver that intensity distribution (segmentation). The intensity modulator is fabricated and quality assurance performed at the factory (.decimal, LLC, Sanford, FL). Clinical quality assurance consists of measuring a fluence distribution in a plane perpendicular to the beam in a water or water-equivalent phantom. This IM-BECT process is described and demonstrated for two sites, postmastectomy chest wall and temple. Dose plans, intensity distributions, fabricated intensity modulators, and quality assurance results are presented.
RESULTS: IM-BECT plans showed improved D
CONCLUSION: These results demonstrated the feasibility of translating IM-BECT to the clinic using the techniques presented for treatment planning, intensity modulator design and fabrication, and quality assurance processes
Spinodal Decomposition and Inflation: Dynamics and Metric Perturbations
We analyse the dynamics of spinodal decomposition in inflationary cosmology
using the closed time path formalism of out of equilibrium quantum field theory
combined with the non-perturbative Hartree approximation. In addition to a
general analysis, we compute the detailed evolution of two inflationary models
of particular importance: lambda Phi^4 new inflation and natural inflation. We
compute the metric fluctuations resulting from inflationary phase transitions
in the slow roll approximation, showing that there exists a regime for which
quantum fluctuations of the inflaton field result in a significant deviation in
the predictions of the spectrum of primordial density perturbations from
standard results. We provide case examples for which a blue tilt to the power
spectrum (i.e. n_s > 1) results from the evolution of a single inflaton field,
and demonstrate that field fluctuations may result in a scalar amplitude of
fluctuations significantly below standard predictions, resulting in a slight
alleviation of the inflationary fine tuning problem. We show explicitly that
the metric perturbation spectrum resulting from inflation depends upon the
state at the outset of the inflationary phase.Comment: 26 pages, 19 figure
Bostonia: The Boston University Alumni Magazine. Volume 32
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
Size-dependent spinodal and miscibility gaps for intercalation in nano-particles
Using a recently-proposed mathematical model for intercalation dynamics in
phase-separating materials [Singh, Ceder, Bazant, Electrochimica Acta 53, 7599
(2008)], we show that the spinodal and miscibility gaps generally shrink as the
host particle size decreases to the nano-scale. Our work is motivated by recent
experiments on the high-rate Li-ion battery material LiFePO4; this serves as
the basis for our examples, but our analysis and conclusions apply to any
intercalation material. We describe two general mechanisms for the suppression
of phase separation in nano-particles: (i) a classical bulk effect, predicted
by the Cahn-Hilliard equation, in which the diffuse phase boundary becomes
confined by the particle geometry; and (ii) a novel surface effect, predicted
by chemical-potential-dependent reaction kinetics, in which
insertion/extraction reactions stabilize composition gradients near surfaces in
equilibrium with the local environment. Composition-dependent surface energy
and (especially) elastic strain can contribute to these effects but are not
required to predict decreased spinodal and miscibility gaps at the nano-scale
Choosing outcome assessment tools in hämophilia care and research: a multidisciplinary perspective
Introduction: The implementation of early long-term, regular clotting factor concentrate (CFC) replacement therapy ('prophylaxis') has made it possible to offer boys with haemophilia a near normal life. Many different regimens have reported favourable results, but the optimum treatment regimens have not been established and the cost of prophylaxis is very high. Both for optimizing treatment and reimbursement issues, there is a need to provide objective evidence of both short-and long-term results and benefits of prophylactic regimens. Aims: This report presents a critical review of outcome measures for use in the assessment of musculoskeletal health in persons with haemophilia according to the International Classification of Functioning, Disability and Health (ICF). This framework considers structural and functional changes, activities and participation in a context of both personal and environmental factors. Methods: Results were generated by a combination of a critical review of available literature plus expert opinion derived from a two day consensus conference between 48 health care experts from different disciplines involved in haemophilia assessment and care. Outcome tools used in haemophilia were reviewed for reliability and validity in different patient groups and for resources required. Results and conclusion: Recommendations for choice of outcome tools were made according to the ICF domains, economic setting, and reason for use (clinical or research). The next step will be to identify a 'core' set of outcome measures for use in clinical care or studies evaluating treatment
The politics of playing along: radio and regulation in democratic Europe
The loss of localism has been a common trend in most radio markets in Europe
and the United States. Deregulation of ownership led to a concentration
phenomenon that has affected local radios in several western democracies.
New forms of regulation have been considered as possible ways to stop the
erosion of localism by applying rules to markets in the defense of diversity,
pluralism, and the local dimension. This article analyses the local radio market
in Portugal, by assessing the changes in the legislation and by examining the
regulatory action that can, according to its remit, act preventively to avoid
market forces to harm these principles.info:eu-repo/semantics/publishedVersio
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