339 research outputs found

    Connection Between Type A and E Factorizations and Construction of Satellite Algebras

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    Recently, we introduced a new class of symmetry algebras, called satellite algebras, which connect with one another wavefunctions belonging to different potentials of a given family, and corresponding to different energy eigenvalues. Here the role of the factorization method in the construction of such algebras is investigated. A general procedure for determining an so(2,2) or so(2,1) satellite algebra for all the Hamiltonians that admit a type E factorization is proposed. Such a procedure is based on the known relationship between type A and E factorizations, combined with an algebraization similar to that used in the construction of potential algebras. It is illustrated with the examples of the generalized Morse potential, the Rosen-Morse potential, the Kepler problem in a space of constant negative curvature, and, in each case, the conserved quantity is identified. It should be stressed that the method proposed is fairly general since the other factorization types may be considered as limiting cases of type A or E factorizations.Comment: 20 pages, LaTeX, no figure, to be published in J. Phys.

    Mental health of migrants with pre-migration exposure to armed conflict: a systematic review and meta-analysis.

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    BACKGROUND Exposure to armed conflict has been associated with negative mental health consequences. We aimed to estimate the prevalence of generalised anxiety disorder, major depressive disorder, and post-traumatic stress disorder among migrants exposed to armed conflict. METHODS In this systematic review and meta-analysis, we searched online databases (Cochrane Library, Embase, LILACS, PsycInfo [via Ovid], PubMed, and Web of Science Core Collection) for relevant observational studies published between Jan 1, 1994, and June 28, 2021. We included studies that used standardised psychiatric interviews to assess generalised anxiety disorder, major depressive disorder, or post-traumatic stress disorder among migrants (refugees or internally displaced persons; aged ≥18 years) with pre-migration exposure to armed conflict. We excluded studies in which exposure to armed conflict could not be ascertained, studies that included a clinical population or people with chronic diseases that can trigger the onset of mental disease, and studies published before 1994. We used a random effects model to estimate each mental health disorder's pooled prevalence and random effects meta-regression to assess sources of heterogeneity. Two independent reviewers assessed the risk of bias for each study using the Joanna Briggs Institute Checklist for Prevalence Studies. The protocol was registered with PROSPERO, CRD42020209251. FINDINGS Of the 13 935 studies identified, 34 met our inclusion criteria; these studies accounted for 15 549 migrants. We estimated a prevalence of current post-traumatic stress disorder of 31% (95% CI 23-40); prevalence of current major depressive disorder of 25% (17-34); and prevalence of generalised anxiety disorder of 14% (5-35). Younger age was associated with a higher prevalence of current post-traumatic stress disorder (odds ratio 0·95 [95% CI 0·90-0·99]), lifetime post-traumatic stress disorder (0·88 [0·83-0·92]), and current generalised anxiety disorder (0·87 [0·78-0·97]). A longer time since displacement was associated with a lower lifetime prevalence of post-traumatic stress disorder (0·88 [0·81-0·95]) and major depressive disorder (0·81 [0·77-0·86]). Migrating to a middle-income (8·09 [3·06-21·40]) or low-income (39·29 [11·96-129·70]) country was associated with increased prevalence of generalised anxiety disorder. INTERPRETATION Migrants who are exposed to armed conflict are at high risk of mental health disorders. The mental health-care needs of migrants should be assessed soon after resettlement, and adequate care should be provided, with particular attention paid to young adults. FUNDING Marie Skłodowska-Curie Actions (Horizon 2020-COFUND), MinCiencias (Colombia), and Swiss National Science Foundation

    Deflazacort for the treatment of Duchenne Dystrophy: A systematic review

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    BACKGROUND: To complete a systematic review and meta-analysis based on the clinical question: Is Deflazacort (DFZ), a prednisolone derivative, an effective therapy for improving strength, with acceptable side effects, in children with Duchenne Dystrophy (DD)? METHODS: MEDLINE, EMBASE, Current Contents, Dissertation Abstracts, Health Star, PsychINFO and Cochrane, were searched using the following inclusion criteria: 1) A randomized controlled trial comparing DFZ with placebo or another therapy; 2) Male participants age 2–18 years with DD; 3) Outcomes of (a) any form of strength or functional testing, or (b) any form of side effect. RESULTS: Fifteen studies of potential relevance were identified, with five meeting the inclusion criteria. These five studies included 291 children and were published in English language journals between 1994 and 2000. Two studies compared DFZ versus placebo, two studies compared DFZ with prednisone and one study had both placebo and prednisone comparisions. Two large trials were identified that have not been published in article format. Due to the heterogeneity in outcome measures and the inconsistent reporting of summary statistics a meta-analytic approach could not be taken. CONCLUSIONS: Examining individual studies it appears that DFZ improves strength and functional outcomes compared to placebo, but it remains unclear if it has a benefit over prednisone on similar outcomes. Two trials found that DFZ causes less weight gain than prednisone

    Water Oxidation Kinetics of Accumulated Holes on the Surface of a TiO2 Photoanode: A Rate Law Analysis

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    It has been more than 40 years since Fujishima and Honda demonstrated water splitting using TiO2, yet there is still no clear mechanism by which surface holes on TiO2 oxidize water. In this paper, we use a range of complementary techniques to study this reaction that provide a unique insight into the reaction mechanism. Using transient photocurrent and transient absorption spectroscopy, we measure both the kinetics of electron extraction (t50% ≈ 200 μs, 1.5VRHE) and the kinetics of hole oxidation of water (t50% ≈ 100 ms, 1.5VRHE) as a function of applied potential, demonstrating the water oxidation by TiO2 holes is the kinetic bottleneck in this water-splitting system. Photoinduced absorption spectroscopy measurements under 5 s LED irradiation are used to monitor the accumulation of surface TiO2 holes under conditions of photoelectrochemical water oxidation. Under these conditions, we find that the surface density of these holes increases nonlinearly with photocurrent density. In alkali (pH 13.6), this corresponded to a rate law for water oxidation that is third order with respect to surface hole density, with a rate constant kWO = 22 ± 2 nm4·s–1. Under neutral (pH = 6.7) and acidic (pH = 0.6) conditions, the rate law was second order with respect to surface hole density, indicative of a change in reaction mechanism. Although a change in reaction order was observed, the rate of reaction did not change significantly over the wide pH range examined (with TOFs per surface hole in the region of 20–25 s–1 at ∼1 sun irradiance). This showed that the rate-limiting step does not involve OH– nucleophilic attack and demonstrated the versatility of TiO2 as an active water oxidation photocatalyst over a wide range of pH

    Methodological Considerations in the Analysis of Classroom Interaction in Community College Trigonometry

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    We report analyses of classroom interaction in trigonometry classes taught at an American community college focusing on two dimensions: the mathematical novelty of questions that instructors and students ask and the interactional moves that the instructors use to encourage student involvement in the lesson. The analyzed lessons were particularly challenging because existing frameworks that analyze classrooms did not account for the cases in which the delivery mode was lecture. We discuss the analytical strategies we used and show data to illustrate how they help us in capturing the complexity of classroom interaction and differences between instructors when lecture is the primary mode of instructional delivery. We conclude with suggestions for further work.National Science Foundation CAREER award DRL-0745474 to the first authorPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96961/1/Mesa_Lande_MetConsClassInt_DEEPBLUE.pd

    Hydrotherapy as a recovery strategy after exercise: a pragmatic controlled trial

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    Trial registration ClinicalTrials.gov Identifier: NCT01765387Background Our aim was to evaluate the recovery effects of hydrotherapy after aerobic exercise in cardiovascular, performance and perceived fatigue. Methods A pragmatic controlled repeated measures; single-blind trial was conducted. Thirty-four recreational sportspeople visited a Sport-Centre and were assigned to a Hydrotherapy group (experimental) or rest in a bed (control) after completing a spinning session. Main outcomes measures including blood pressure, heart rate, handgrip strength, vertical jump, self-perceived fatigue, and body temperature were assessed at baseline, immediately post-exercise and post-recovery. The hypothesis of interest was the session*time interaction. Results The analysis revealed significant session*time interactions for diastolic blood pressure (P=0.031), heart rate (P=0.041), self perceived fatigue (P=0.046), and body temperature (P=0.001); but not for vertical jump (P=0.437), handgrip (P=0.845) or systolic blood pressure (P=0.266). Post-hoc analysis revealed that hydrotherapy resulted in recovered heart rate and diastolic blood pressure similar to baseline values after the spinning session. Further, hydrotherapy resulted in decreased self-perceived fatigue after the spinning session. Conclusions Our results support that hydrotherapy is an adequate strategy to facilitate cardiovascular recovers and perceived fatigue, but not strength, after spinning exercise

    Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay

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    We reconstruct the rare decays B+K+μ+μB^+ \to K^+\mu^+\mu^-, B0K(892)0μ+μB^0 \to K^{*}(892)^0\mu^+\mu^-, and Bs0ϕ(1020)μ+μB^0_s \to \phi(1020)\mu^+\mu^- in a data sample corresponding to 4.4fb14.4 {\rm fb^{-1}} collected in ppˉp\bar{p} collisions at s=1.96TeV\sqrt{s}=1.96 {\rm TeV} by the CDF II detector at the Fermilab Tevatron Collider. Using 121±16121 \pm 16 B+K+μ+μB^+ \to K^+\mu^+\mu^- and 101±12101 \pm 12 B0K0μ+μB^0 \to K^{*0}\mu^+\mu^- decays we report the branching ratios. In addition, we report the measurement of the differential branching ratio and the muon forward-backward asymmetry in the B+B^+ and B0B^0 decay modes, and the K0K^{*0} longitudinal polarization in the B0B^0 decay mode with respect to the squared dimuon mass. These are consistent with the theoretical prediction from the standard model, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the Bs0ϕμ+μdecayandmeasureitsbranchingratioB^0_s \to \phi\mu^+\mu^- decay and measure its branching ratio {\mathcal{B}}(B^0_s \to \phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}using using 27 \pm 6signalevents.Thisiscurrentlythemostrare signal events. This is currently the most rare B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let

    Measurements of the properties of Lambda_c(2595), Lambda_c(2625), Sigma_c(2455), and Sigma_c(2520) baryons

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    We report measurements of the resonance properties of Lambda_c(2595)+ and Lambda_c(2625)+ baryons in their decays to Lambda_c+ pi+ pi- as well as Sigma_c(2455)++,0 and Sigma_c(2520)++,0 baryons in their decays to Lambda_c+ pi+/- final states. These measurements are performed using data corresponding to 5.2/fb of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. Exploiting the largest available charmed baryon sample, we measure masses and decay widths with uncertainties comparable to the world averages for Sigma_c states, and significantly smaller uncertainties than the world averages for excited Lambda_c+ states.Comment: added one reference and one table, changed order of figures, 17 pages, 15 figure

    Birth weight and blood lipid levels in Spanish adolescents: Influence of selected APOE, APOC3 and PPARgamma2 gene polymorphisms. The AVENA Study

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    Background There is increasing evidence indicating that genes involved in certain metabolic processes of cardiovascular diseases may be of particular influence in people with low body weight at birth. We examined whether the apolipoprotein (APO) E, APOC3 and the peroxisome proliferator-activated receptor-γ-2 (PPARγ2) polymorphisms influence the association between low birth weight and blood lipid levels in healthy adolescents aged 13–18.5 years. Methods A cross-sectional study of 502 Spanish adolescents born at term was conducted. Total (TC) and high density lipoprotein cholesterol (HDLc), triglycerides (TG), apolipoprotein (apo) A and B, and lipoprotein(a) [Lp(a)] were measured. Low density lipoprotein cholesterol (LDLc), TC-HDLc, TC/HDLc and apoB/apoA were calculated. Results Low birth weight was associated with higher levels of TC, LDLc, apoB, Lp(a), TC-HDLc, TC/HDLc and apoB/apoA in males with the APOE ε3ε4 genotype, whereas in females, it was associated with lower HDLc and higher TG levels. In males with the APOC3 S1/S2 genotype, low birth weight was associated with lower apoA and higher Lp(a), yet this association was not observed in females. There were no associations between low birth weight and blood lipids in any of the PPARγ2 genotypes. Conclusion The results indicate that low birth weight has a deleterious influence on lipid profile particularly in adolescents with the APOE ε3/ε4 genotype. These findings suggest that intrauterine environment interact with the genetic background affecting the lipid profile in later life.The AVENA study was supported by the Spanish Ministry of Health Instituto de Salud Carlos III (FIS PI021830), the Spanish Ministry of Health, FEDER-FSE funds FIS n° 00/0015, CSD grants 05/UPB32/0, 109/UPB31/03 and 13/UPB20/04, the Spanish Ministry of Education (AP-2004-2745; EX-2007-1124), scholarships from Panrico S.A., Madaus S.A. and Procter and Gamble S.A
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