3,638 research outputs found
Restoration of chiral symmetry in quark models with effective one gluon exchange
The restoration of chiral symmetry at finite density and/or temperature is
investigated in a wide class of one-gluon exchange models in the instantaneous
approximation. If the effective quark interaction is less divergent than
for small momentum transfer , we obtain Gaussian critical exponents
for the chiral phase transitions at finite temperature and density,
respectively. In the opposite case, for an interaction diverging faster than
in the infrared region, a qualitative different behavior of the quark
self-energy near the critical Fermi momentum and the critical temperature
, respectively, is observed. In the first scenario, we find , which compares well with recent data from QCD lattice
simulations.Comment: 12 pages LaTeX, no figure
Recommended from our members
Preliminary Results of American Eel Sampling Efforts in Gulf of Mexico Drainages of Texas
American Eel Anguilla rostrata has a unique and complex life history that is fairly well-studied on the eastern coast of the United States, but few studies have been done on Gulf of Mexico drainages. To inform conservation and management decisions, efforts to better understand the population structure, seasonal dynamics, and life history of American Eel are underway. The primary objectives of our efforts are to assess the current and historical distribution and abundance, habitat use, movement patterns, parasite occurrence, diet and population structure of American Eel across all life stages in Gulf of Mexico drainages of Texas.Texas State Wildlife Grant Program grants T-173-R-1 and T-172-R-1 in cooperation with the U.S. Fish and Wildlife Service, Wildlife and Sport Fish Restoration ProgramIntegrative Biolog
A facility for high resolution spectroscopy: Laboratory and ground based observations in support of upper atmospheric research
This research task consists of operating a facility for making spectroscopic observations in support of upper atmospheric research. The facility responds to the needs and interests of the visiting investigators. Therefore, the research objectives are not predetermined except in broad outline. The emphasis is on studies that take advantage of the particular strengths of the Fourier Transform Spectrometer on Kitt Peak: high spectral resolution combined with wide spectral range and low noise
Measuring Stellar Radial Velocities with a Dispersed Fixed-Delay Interferometer
We demonstrate the ability to measure precise stellar barycentric radial
velocities with the dispersed fixed-delay interferometer technique using the
Exoplanet Tracker (ET), an instrument primarily designed for precision
differential Doppler velocity measurements using this technique. Our
barycentric radial velocities, derived from observations taken at the KPNO 2.1
meter telescope, differ from those of Nidever et al. by 0.047 km/s (rms) when
simultaneous iodine calibration is used, and by 0.120 km/s (rms) without
simultaneous iodine calibration. Our results effectively show that a Michelson
interferometer coupled to a spectrograph allows precise measurements of
barycentric radial velocities even at a modest spectral resolution of R ~ 5100.
A multi-object version of the ET instrument capable of observing ~500 stars per
night is being used at the Sloan 2.5 m telescope at Apache Point Observatory
for the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS),
a wide-field radial velocity survey for extrasolar planets around TYCHO-2 stars
in the magnitude range 7.6<V<12. In addition to precise differential
velocities, this survey will also yield precise barycentric radial velocities
for many thousands of stars using the data analysis techniques reported here.
Such a large kinematic survey at high velocity precision will be useful in
identifying the signature of accretion events in the Milky Way and
understanding local stellar kinematics in addition to discovering exoplanets,
brown dwarfs and spectroscopic binaries.Comment: 9 pages, 4 figures. Accepted for publication in Ap
Web-based physiotherapy for people affected by multiple sclerosis: a single blind, randomized controlled feasibility study
Objective:
To examine the feasibility of a trial to evaluate web-based physiotherapy compared to a standard home exercise programme in people with multiple sclerosis.
Design:
Multi-centre, randomized controlled, feasibility study.
Setting:
Three multiple sclerosis out-patient centres.
Participants:
A total of 90 people with multiple sclerosis (Expanded Disability Status Scale 4–6.5).
Interventions:
Participants were randomized to a six-month individualized, home exercise programme delivered via web-based physiotherapy (n = 45; intervention) or a sheet of exercises (n = 45; active comparator).
Outcome measures:
Outcome measures (0, three, six and nine months) included adherence, two-minute walk test, 25 foot walk, Berg Balance Scale, physical activity and healthcare resource use. Interviews were undertaken with 24 participants and 3 physiotherapists.
Results:
Almost 25% of people approached agreed to take part. No intervention-related adverse events were recorded. Adherence was 40%–63% and 53%–71% in the intervention and comparator groups. There was no difference in the two-minute walk test between groups at baseline (Intervention-80.4(33.91)m, Comparator-70.6(31.20)m) and no change over time (at six-month Intervention-81.6(32.75)m, Comparator-74.8(36.16)m. There were no significant changes over time in other outcome measures except the EuroQol-5 Dimension at six months which decreased in the active comparator group. For a difference of 8(17.4)m in two-minute walk test between groups, 76 participants/group would be required (80% power, P > 0.05) for a future randomized controlled trial.
Conclusion:
No changes were found in the majority of outcome measures over time. This study was acceptable and feasible by participants and physiotherapists. An adequately powered study needs 160 participants
Handover patterns: an observational study of critical care physicians
Abstract
Background
Handover (or 'handoff') is the exchange of information between health professionals that accompanies the transfer of patient care. This process can result in adverse events. Handover 'best practices', with emphasis on standardization, have been widely promoted. However, these recommendations are based mostly on expert opinion and research on medical trainees. By examining handover communication of experienced physicians, we aim to inform future research, education and quality improvement. Thus, our objective is to describe handover communication patterns used by attending critical care physicians in an academic centre and to compare them with currently popular, standardized schemes for handover communication.
Methods
Prospective, observational study using video recording in an academic intensive care unit in Ontario, Canada. Forty individual patient handovers were randomly selected out of 10 end-of-week handover sessions of attending physicians. Two coders independently reviewed handover transcripts documenting elements of three communication schemes: SBAR (Situation, Background, Assessment, Recommendations); SOAP (Subjective, Objective, Assessment, Plan); and a standard medical admission note. Frequency and extent of questions asked by incoming physicians were measured as well. Analysis consisted of descriptive statistics.
Results
Mean (± standard deviation) duration of patient-specific handovers was 2 min 58 sec (± 57 sec). The majority of handovers' content consisted of recent and current patient status. The remainder included physicians' interpretations and advice. Questions posed by the incoming physicians accounted for 5.8% (± 3.9%) of the handovers' content. Elements of all three standardized communication schemes appeared repeatedly throughout the handover dialogs with no consistent pattern. For example, blocks of SOAP's Assessment appeared 5.2 (± 3.0) times in patient handovers; they followed Objective blocks in only 45.9% of the opportunities and preceded Plan in just 21.8%. Certain communication elements were occasionally absent. For example, SBAR's Recommendation and admission note information about the patient's Past Medical History were absent from 22 (55.0%) and 20 (50.0%), respectively, of patient handovers.
Conclusions
Clinical handover practice of faculty-level critical care physicians did not conform to any of the three predefined structuring schemes. Further research is needed to examine whether alternative approaches to handover communication can be identified and to identify features of high-quality handover communication.http://deepblue.lib.umich.edu/bitstream/2027.42/112680/1/12913_2011_Article_1919.pd
Distinguishing problematic from nonproblematic postsurgical pain: A pain trajectory analysis after total knee arthroplasty
The goal of this study was to follow a cohort of patients undergoing total knee arthroplasty over time to: (1) identify and describe the various pain trajectories beginning preoperatively and for up to 12 months after surgery, (2) identify baseline predictors of trajectory group membership, and (3) identify trajectory groups associated with poor psychosocial outcomes 12 months after surgery. One hundred seventy-three participants (female = 85 [49%]; mean age [years] = 62.9, SD = 6.8) completed pain and psychological questionnaires and functional performance tests preoperatively and 4 days, 6 weeks, and 3 and 12 months after total knee arthroplasty. Using growth mixture modeling, results showed that a 4-group model, with a quadratic slope and baseline pain data predicting trajectory group membership, best fit the data (Akaike information criterion = 2772.27). The first 3 pain trajectories represent various rates of recovery ending with relatively low levels of pain 12 months after surgery. Group 4, the constant high pain group, comprises patients who have a neutral or positive pain slope and do not show improvement in their pain experience over the first year after surgery. This model suggests that preoperative pain levels are predictive of pain trajectory group membership and moderate preoperative pain, as opposed to low or high pain, is a risk factor for a neutral or positive pain trajectory postoperatively. Consistent with previous studies, these results show that postoperative pain is not a homogeneous condition and point to the importance of examining intraindividual pain fluctuations as they relate to pain interventions and prevention strategies.M. G. Page´ is supported by a Canada Graduate Scholarship— Doctoral Award from the Canadian Institutes of Health Research (CIHR) and is a recipient of a Lillian-Wright Maternal-Child Health Scholarship from York University, a trainee member of Pain in Child Health and a CIHR Strategic Training Fellow in Pain: Molecules to Community. J. Katz is supported by a CIHR Canada Research Chair in Health Psychology at York University. H. A. Clarke is supported by a Merit Award from the Department of Anaesthesia at the University of Toronto and also supported by the STAGE Training Program in Genetic Epidemiology from the CIHR. The remaining authors have no conflicts of interest to declare
Antibody response to pneumococcal and influenza vaccination in patients with rheumatoid arthritis receiving abatacept
Background Patients with rheumatoid arthritis (RA), including those treated
with biologics, are at increased risk of some vaccine-preventable infections.
We evaluated the antibody response to standard 23-valent pneumococcal
polysaccharide vaccine (PPSV23) and the 2011–2012 trivalent seasonal influenza
vaccine in adults with RA receiving subcutaneous (SC) abatacept and background
disease-modifying anti-rheumatic drugs (DMARDs). Methods Two multicenter,
open-label sub-studies enrolled patients from the ACQUIRE (pneumococcal and
influenza) and ATTUNE (pneumococcal) studies at any point during their SC
abatacept treatment cycle following completion of ≥3 months’ SC abatacept. All
patients received fixed-dose abatacept 125 mg/week with background DMARDs. A
pre-vaccination blood sample was taken, and after 28 ± 3 days a final post-
vaccination sample was collected. The primary endpoint was the proportion of
patients achieving an immunologic response to the vaccine at Day 28 among
patients without a protective antibody level to the vaccine antigens at
baseline (pneumococcal: defined as ≥2-fold increase in post-vaccination titers
to ≥3 of 5 antigens and protective antibody level of ≥1.6 μg/mL to ≥3 of 5
antigens; influenza: defined as ≥4-fold increase in post-vaccination titers to
≥2 of 3 antigens and protective antibody level of ≥1:40 to ≥2 of 3 antigens).
Safety and tolerability were evaluated throughout the sub-studies. Results
Pre- and post-vaccination titers were available for 113/125 and 186/191
enrolled patients receiving the PPSV23 and influenza vaccine, respectively.
Among vaccinated patients, 47/113 pneumococcal and 121/186 influenza patients
were without protective antibody levels at baseline. Among patients with
available data, 73.9 % (34/46) and 61.3 % (73/119) met the primary endpoint
and achieved an immunologic response to PPSV23 or influenza vaccine,
respectively. In patients with pre- and post-vaccination data available, 83.9
% in the pneumococcal study demonstrated protective antibody levels with
PPSV23 (titer ≥1.6 μg/mL to ≥3 of 5 antigens), and 81.2 % in the influenza
study achieved protective antibody levels (titer ≥1:40 to ≥2 of 3 antigens) at
Day 28 post-vaccination. Vaccines were well tolerated with SC abatacept with
background DMARDs. Conclusions In these sub-studies, patients with RA
receiving SC abatacept and background DMARDs were able to mount an appropriate
immune response to pneumococcal and influenza vaccines. Trial registration
NCT00559585 (registered 15 November 2007) and NCT00663702 (registered 18 April
2008)
QCD Down Under: Building Bridges
The strong coupling regime of QCD is responsible for 99% of hadronic
phenomena. Though considerable progress has been made in solving QCD in this
non-perturbative region, we nevertheless have to rely on a disparate range of
models and approximations. If we are to gain an understanding of the underlying
physics and not just have numerical answers from computing `` black'' boxes, we
must build bridges between the parameter space where models and approximations
are valid to the regime describing experiment, and between the different
modellings of strong dynamics. We describe here how the
Schwinger-Dyson/Bethe-Salpeter approach provides just such a bridge, linking
physics, the lattice and experiment.Comment: 8 pages, 10 figures. Opening talk at Workshop on QCD Down Under,
March 2004, Barossa Valley and Adelaide (to be published in the Proceedings
- …