2,429 research outputs found
The ring imaging Cherenkov detector for the BRAHMS experiment at RHIC
A ring imaging Cherenkov counter, to be read out by four 100-channel PMTs, is
a key element of the BRAHMS experiment. We report here the most recent results
obtained tested at the BNL AGS using several radiator gases, including the
heavy fluorocarbon C4F10. Ring radii were measured for different particles
(pions, muons, and electrons) for momenta ranging from 2 to 12 GeV/c employing
pure C4F10 as radiator.Comment: 3 pages 3 figure
Perceptions Regarding Distance Learning in Higher Education, Smoothing the Transition.
This paper presents the perceptions on distance learning approaches, assessed through an online survey, using experimental design of ideas (Mind Genomics). Students and professors of higher education institutions who had not yet experienced distance learning before COVID-19 pandemic period participated in the study. The participants belong to the universities located in Mediterranean basin, e.g., Albania, Italy, Morocco, Algeria and few African countries.
Results suggest that distance learning will shift many of the responsibilities formerly on the professors to those of the students. The data suggests the need for emotional support during this transition, specifically to maintain interaction among students and professor as well as among students themselves in distance learning platforms as in traditional classrooms. The study shows that the effectiveness and the interactivity of this new paradigm are very important and any further developments of distance learning should provide strong support for these components. The position of the professor is indispensable as the guide to the entire process, suggesting that at least at the time of this writing (2020) distance learning approach is perceived only to be an intermittent complementary path to in-person interactions
Factors associated with post-arrest withdrawal of life-sustaining therapy.
INTRODUCTION: Most successfully resuscitated cardiac arrest patients do not survive to hospital discharge. Many have withdrawal of life sustaining therapy (WLST) as a result of the perception of poor neurologic prognosis. The characteristics of these patients and differences in their post-arrest care are largely unknown.
METHODS: Utilizing the Penn Alliance for Therapeutic Hypothermia Registry, we identified a cohort of 1311 post-arrest patients from 26 hospitals from 2010 to 2014 who remained comatose after return of spontaneous circulation. We stratified patients by whether they had WLST post-arrest and analyzed demographic, arrest, and post-arrest variables.
RESULTS: In our cohort, 565 (43%) patients had WLST. In multivariate regression, patients who had WLST were less likely to go to the cardiac catheterization lab (OR 0.40; 95% CI: 0.26-0.62) and had shorter hospital stays (OR 0.93; 95% CI: 0.91-0.95). When multivariate regression was limited to patient demographics and arrest characteristics, patients with WLST were older (OR 1.18; 95% CI: 1.07-1.31 by decade), had a longer arrest duration (OR 1.14; 95% CI: 1.05-1.25 per 10min), more likely to be female (OR: 1.41; 95% CI: 1.01-1.96), and less likely to have a witnessed arrest (OR 0.65; 95% CI: 0.42-0.98).
CONCLUSION: Patients with WLST differ in terms of demographic, arrest, and post-arrest characteristics and treatments from those who did not have WLST. Failure to account for this variability could affect both clinical practice and the interpretation of research
Moving from evidence-based medicine to evidence-based health.
While evidence-based medicine (EBM) has advanced medical practice, the health care system has been inconsistent in translating EBM into improvements in health. Disparities in health and health care play out through patients' limited ability to incorporate the advances of EBM into their daily lives. Assisting patients to self-manage their chronic conditions and paying attention to unhealthy community factors could be added to EBM to create a broader paradigm of evidence-based health. A perspective of evidence-based health may encourage physicians to consider their role in upstream efforts to combat socially patterned chronic disease
Phase Splitting for Periodic Lie Systems
In the context of the Floquet theory, using a variation of parameter
argument, we show that the logarithm of the monodromy of a real periodic Lie
system with appropriate properties admits a splitting into two parts, called
dynamic and geometric phases. The dynamic phase is intrinsic and linked to the
Hamiltonian of a periodic linear Euler system on the co-algebra. The geometric
phase is represented as a surface integral of the symplectic form of a
co-adjoint orbit.Comment: (v1) 15 pages. (v2) 16 pages. Some typos corrected. References and
further comments added. Final version to appear in J. Phys. A
Continuous-time link-based kinematic wave model: formulation, solution existence, and well-posedness
We present a continuous-time link-based kinematic wave model (LKWM) for
dynamic traffic networks based on the scalar conservation law model. Derivation
of the LKWM involves the variational principle for the Hamilton-Jacobi equation
and junction models defined via the notions of demand and supply. We show that
the proposed LKWM can be formulated as a system of differential algebraic
equations (DAEs), which captures shock formation and propagation, as well as
queue spillback. The DAE system, as we show in this paper, is the
continuous-time counterpart of the link transmission model. In addition, we
present a solution existence theory for the continuous-time network model and
investigate continuous dependence of the solution on the initial data, a
property known as well-posedness. We test the DAE system extensively on several
small and large networks and demonstrate its numerical efficiency.Comment: 39 pages, 14 figures, 2 tables, Transportmetrica B: Transport
Dynamics 201
The role of cardiac troponin T quantity and function in cardiac development and dilated cardiomyopathy
Background: Hypertrophic (HCM) and dilated (DCM) cardiomyopathies results from sarcomeric protein mutations, including cardiac troponin T (cTnT, TNNT2). We determined whether TNNT2 mutations cause cardiomyopathies by altering cTnT function or quantity; whether the severity of DCM is related to the ratio of mutant to wildtype cTnT; whether Ca2+ desensitization occurs in DCM; and whether absence of cTnT impairs early embryonic cardiogenesis. Methods and Findings: We ablated Tnnt2 to produce heterozygous Tnnt2+/ mice, and crossbreeding produced homozygous null Tnnt2-/-embryos. We also generated transgenic mice overexpressing wildtype (TGWT) or DCM mutant (TGK210Δ) Tnnt2. Crossbreeding produced mice lacking one allele of Tnnt2, but carrying wildtype (Tnnt2+/-/TGWT) or mutant (Tnnt2+/-/TGK210Δ) transgenes. Tnnt2+/-mice relative to wildtype had significantly reduced transcript (0.82 ± 0.06 [SD] vs. 1.00 ± 0.12 arbitrary units; p = 0.025), but not protein (1.01 ± 0.20 vs. 1.00 ± 0.13 arbitrary units; p = 0.44). Tnnt2+/-mice had normal hearts (histology, mass, left ventricular end diastolic diameter [LVEDD], fractional shortening [FS]). Moreover, whereas Tnnt2+/-/ TGK210Δ mice had severe DCM, TGK210Δ mice had only mild DCM (FS 18 ± 4 vs. 29 ± 7%; p < 0.01). The difference in severity of DCM may be attributable to a greater ratio of mutant to wildtype Tnnt2 transcript in Tnnt2+/-/TGK210Δ relative to TGK210Δ mice (2.42±0.08, p = 0.03). Tnnt2+/-/TGK210Δ muscle showed Ca2+ desensitization (pCa50 = 5.34 ± 0.08 vs. 5.58 ± 0.03 at sarcomere length 1.9 μm. p<0.01), but no difference in maximum force generation. Day 9.5 Tnnt2-/-embryos had normally looped hearts, but thin ventricular walls, large pericardial effusions, noncontractile hearts, and severely disorganized sarcomeres. Conclusions: Absence of one Tnnt2 allele leads to a mild deficit in transcript but not protein, leading to a normal cardiac phenotype. DCM results from abnormal function of a mutant protein, which is associated with myocyte Ca2+ desensitization. The severity of DCM depends on the ratio of mutant to wildtype Tnnt2 transcript. cTnT is essential for sarcomere formation, but normal embryonic heart looping occurs without contractile activity. © 2008 Ahmad et al
Effect of information about organic production on beef liking and consumer willingness to pay
The present study was aimed to assess the effect of information about organic production on beef liking and consumer willingness to pay. Mean scores of perceived liking were higher for organic beef (OB) as
compared to conventional beef (CB). Expected liking scores were higher for OB than for CB. For OB the expected liking was significantly higher than the perceived liking expressed in blind conditions (negative disconfirmation), whereas for CB no difference was observed. Consumers completely assimilated their liking for OB in the direction of expectations. Consumers showed a willingness to pay for OB higher than the suggested price (P < 0.001), the latter corresponding to the local commercial value for organic beef.
We conclude that the information about organic farming can be a major determinant of beef liking, thus providing a potential tool for meat differentiation to traditional farms
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