407 research outputs found
The Interface between Quantum Mechanics and General Relativity
The generation, as well as the detection, of gravitational radiation by means
of charged superfluids is considered. One example of such a "charged
superfluid" consists of a pair of Planck-mass-scale, ultracold "Millikan oil
drops," each with a single electron on its surface, in which the oil of the
drop is replaced by superfluid helium. When levitated in a magnetic trap, and
subjected to microwave-frequency electromagnetic radiation, a pair of such
"Millikan oil drops" separated by a microwave wavelength can become an
efficient quantum transducer between quadrupolar electromagnetic and
gravitational radiation. This leads to the possibility of a Hertz-like
experiment, in which the source of microwave-frequency gravitational radiation
consists of one pair of "Millikan oil drops" driven by microwaves, and the
receiver of such radiation consists of another pair of "Millikan oil drops" in
the far field driven by the gravitational radiation generated by the first
pair. The second pair then back-converts the gravitional radiation into
detectable microwaves. The enormous enhancement of the conversion efficiency
for these quantum transducers over that for electrons arises from the fact that
there exists macroscopic quantum phase coherence in these charged superfluid
systems.Comment: 22 pages, 7 figures; Lamb medal lecture on January 5, 2006 at the
Physics of Quantum Electronics Winter Colloquium at Snowbird, Utah; accepted
for publication in J. Mod. Optic
Simulating Reionization: Character and Observability
In recent years there has been considerable progress in our understanding of
the nature and properties of the reionization process. In particular, the
numerical simulations of this epoch have made a qualitative leap forward,
reaching sufficiently large scales to derive the characteristic scales of the
reionization process and thus allowing for realistic observational predictions.
Our group has recently performed the first such large-scale radiative transfer
simulations of reionization, run on top of state-of-the-art simulations of
early structure formation. This allowed us to make the first realistic
observational predictions about the Epoch of Reionization based on detailed
radiative transfer and structure formation simulations. We discuss the basic
features of reionization derived from our simulations and some recent results
on the observational implications for the high-redshift Ly-alpha sources.Comment: 3 pages, to appear in the Proceedings of First Stars III, Santa Fe,
July 2007, AIP Conference Serie
HIV-1 transmitting couples have similar viral load set-points in Rakai, Uganda.
Published versio
Case Study 3: Movement Lawyers and Community Organizers in Litigation: Issues of Finances and Collaboration
This essay represents one of several Case Studies published as the Movement Lawyering Roundtable Symposium by Hofstra Law Review. The Case Studies were developed within a roundtable of movement lawyers, community organizers, and legal ethics experts convened in March, 2018 by the Monroe H. Freedman Institute for the Study of Legal Ethics at Hofstra University’s Maurice A. Deane School of Law. This Case Study addresses the ethical tensions encountered by movement lawyers and community organizers engaged in public interest litigation. The Study consists of three topics, with resulting ethics analyses of the issues that arise in the differing settings. The first involves questions of financing the broad work of a community organizing client, while honoring the mandates of the rule of professional conduct prohibiting a lawyer from offering financial assistance to clients in litigation. The second issue addressed how lawyers might share attorneys’ fees awards with community groups who are ongoing clients. The third issue pivots to questions of how movement lawyers might counsel community organizations about disagreements with other pro bono lawyers representing the clients. Each of these sets of legal ethics issues arises in movement lawyering practice, and can be confounding. This essay seeks to offer guidance to lawyers navigating these sometimes delicate ethical waters
Prospective, randomized evaluation of a personal digital assistant-based research tool in the emergency department
Background
Personal digital assistants (PDA) offer putative advantages over paper for collecting research data. However, there are no data prospectively comparing PDA and paper in the emergency department. The aim of this study was to prospectively compare the performance of PDA and paper enrollment instruments with respect to time required and errors generated.
Methods
We randomized consecutive patients enrolled in an ongoing prospective study to having their data recorded either on a PDA or a paper data collection instrument. For each method, we recorded the total time required for enrollment, and the time required for manual transcription (paper) onto a computer database. We compared data error rates by examining missing data, nonsensical data, and errors made during the transcription of paper forms. Statistical comparisons were performed by Kruskal-Wallis and Poisson regression analyses for time and errors, respectively.
Results
We enrolled 68 patients (37 PDA, 31 paper). Two of 31 paper forms were not available for analysis. Total data gathering times, inclusive of transcription, were significantly less for PDA (6:13 min per patient) compared to paper (9:12 min per patient; p < 0.001). There were a total of 0.9 missing and nonsense errors per paper form compared to 0.2 errors per PDA form (p < 0.001). An additional 0.7 errors per paper form were generated during transcription. In total, there were 1.6 errors per paper form and 0.2 errors per PDA form (p < 0.001).
Conclusion
Using a PDA-based data collection instrument for clinical research reduces the time required for data gathering and significantly improves data integrity
Association between adherence to calcium-channel blocker and statin medications and likelihood of cardiovascular events among US managed care enrollees
<p>Abstract</p> <p>Background</p> <p>Prior studies have found that patients taking single-pill amlodipine/atorvastatin (SPAA) have greater likelihood of adherence at 6 months than those taking 2-pill calcium-channel blocker and statin combinations (CCB/statin). This study examines whether this adherence benefit results in fewer cardiovascular (CV) events.</p> <p>Methods</p> <p>A retrospective cohort study was conducted using administrative claims data from the IMS LifeLink: US Health Plan Claims database, identifying adults already taking CCB or statin (but not both) who had an index event of either initiating treatment with SPAA or adding CCB to statin (or vice versa) between April 1, 2004 to August 31, 2005. Inclusion criteria included age 18+ years, continuously enrolled for minimum of 6 months prior and 18 months following treatment initiation, >1 diagnosis of hypertension, and no prescription claims for SPAA or added CCB or statin for 6 months prior. Exclusion criteria included >1 claim with missing or invalid days supplied, age 65+ years and not enrolled in Medicare Advantage, or history of prior CV events, cancer diagnosis, or chronic renal failure. The primary outcome measure was the rate of CV events (myocardial infarction, heart failure, angina, other ischemic heart disease, stroke, peripheral vascular disease, or revascularization procedure) from 6 to 18 months following index date, analyzed at three levels: 1) all adherent vs. non-adherent patients, 2) SPAA vs. dual-pill patients (regardless of adherence level), and 3) adherent SPAA, adherent dual-pill, and non-adherent SPAA patients vs. non-adherent dual-pill patients.</p> <p>Results</p> <p>Of 1,537 SPAA patients, 56.5% were adherent at 6 months, compared with 21.4% of the 17,910 CCB/statin patients (p < 0.001). Logistic regression found SPAA patients more likely to be adherent (OR = 4.7, p < 0.001) than CCB/statin patients. In Cox proportional hazards models, being adherent to either regimen was associated with significantly lower risk of CV event (HR = 0.77, p = 0.003). A similar effect was seen for SPAA vs. CCB/statin patients (HR = 0.68, p = 0.02). In a combined model, the risk of CV events was significantly lower for adherent CCB/statin patients (HR = 0.79, p = 0.01) and adherent SPAA patients (HR = 0.61, p = 0.03) compared to non-adherent CCB/statin patients.</p> <p>Conclusions</p> <p>Patients receiving SPAA rather than a 2-pill CCB/statin regimen are more likely to be adherent. In turn, adherence to CCB and statin medications is associated with lower risk of CV events in primary prevention patients.</p
Why are family carers of people with dementia dissatisfied with general hospital care?: a qualitative study
Background
Families and other carers report widespread dissatisfaction with general hospital care for confused older people.
Methods
We undertook a qualitative interviews study of 35 family carers of 34 confused older patients to ascertain their experiences of care on geriatric and general medical, and orthopaedic wards of a large English hospital. Transcripts were analysed using a grounded theory approach. Themes identified in interviews were categorised, and used to build a model explaining dissatisfaction with care.
Results
The experience of hospital care was often negative. Key themes were events (illness leading to admission, experiences in the hospital, adverse occurrences including deterioration in health, or perceived poor care); expectations (which were sometimes unrealistic, usually unexplored by staff, and largely unmet from the carers’ perspective); and relationships with staff (poor communication and conflict over care). Expectations were influenced by prior experience. A cycle of discontent is proposed. Events (or ‘crises’) are associated with expectations. When these are unmet, carers become uncertain or suspicious, which leads to a period of ‘hyper vigilant monitoring’ during which carers seek out evidence of poor care, culminating in challenge, conflict with staff, or withdrawal, itself a crisis. The cycle could be completed early during the admission pathway, and multiple cycles within a single admission were seen.
Conclusion
People with dementia who have family carers should be considered together as a unit. Family carers are often stressed and tired, and need engaging and reassuring. They need to give and receive information about the care of the person with dementia, and offered the opportunity to participate in care whilst in hospital. Understanding the perspective of the family carer, and recognising elements of the ‘cycle of discontent’, could help ward staff anticipate carer needs, enable relationship building, to pre-empt or avoid dissatisfaction or conflict
Spatial Targeting for Bovine Tuberculosis Control: Can the Locations of Infected Cattle Be Used to Find Infected Badgers?
Microneedles: A New Frontier in Nanomedicine Delivery
This review aims to concisely chart the development of two individual research fields, namely nanomedicines, with specific emphasis on nanoparticles (NP) and microparticles (MP), and microneedle (MN) technologies, which have, in the recent past, been exploited in combinatorial approaches for the efficient delivery of a variety of medicinal agents across the skin. This is an emerging and exciting area of pharmaceutical sciences research within the remit of transdermal drug delivery and as such will undoubtedly continue to grow with the emergence of new formulation and fabrication methodologies for particles and MN. Firstly, the fundamental aspects of skin architecture and structure are outlined, with particular reference to their influence on NP and MP penetration. Following on from this, a variety of different particles are described, as are the diverse range of MN modalities currently under development. The review concludes by highlighting some of the novel delivery systems which have been described in the literature exploiting these two approaches and directs the reader towards emerging uses for nanomedicines in combination with MN
Updated projections of future vCJD deaths in the UK
BACKGROUND: Past projections of the future course of the vCJD epidemic in the UK have shown considerable uncertainty, with wide confidence bounds. However, recent vCJD case data have indicated a decrease in the annual incidence of deaths over the past two years. METHODS: A detailed survival model is fitted to the 121 vCJD deaths reported by the end of 2002 stratified by age and calendar time to obtain projections of future incidence. The model is additionally fitted to recent results from a survey of appendix tissues. RESULTS: Our results show a substantial decrease in the uncertainty of the future course of the primary epidemic in the susceptible genotype (MM-homozygous at codon 129 of the prion protein gene), with a best estimate of 40 future deaths (95% prediction interval 9–540) based on fitting to the vCJD case data alone. Additional fitting of the appendix data increases these estimates (best estimate 100, 95% prediction interval 10–2,600) but remains lower than previous projections. CONCLUSIONS: The primary vCJD epidemic in the known susceptible genotype in the UK appears to be in decline
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