1,720 research outputs found

    Resources and student achievement – evidence from a Swedish policy reform

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    This paper utilizes a policy change to estimate the effect of teacher density on student performance. We find that an increase in teacher density has a positive effect on student achievement. The baseline estimate – obtained by using the grade point average as the outcome variable – implies that resource increases corresponding to the class-size reduction in the STAR-experiment (i.e., a reduction of 7 students) improves performance by 2.6 percentile ranks (or 0.08 standard deviations). When we use test score data for men, potentially a more objective measure of student performance, the effect of resources appears to be twice the size of the baseline estimate.Student performance; teacher/student ratio; policy reform; differences-in-differences

    The prevalence of, and factors associated with, paying for sex among men resident in Britain: findings from the third national survey of sexual attitudes and lifestyles (Natsal-3)

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    Objectives Men who pay for sex (MPS) are considered a bridging population for sexually transmitted infections (STI). However, the extent, characteristics and role of MPS in transmission is poorly understood. We investigate these questions using data from Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Methods We performed complex survey analyses of data from 6293 men aged 16–74 years resident in Britain who completed Natsal-3, a probability sample survey undertaken during 2010–2012, using computer-assisted personal interviewing and computer-assisted self-interview. Results 11.0% (95% CI10.1% to 11.9%) of all men reported ever paying for sex. Among MPS, 18.4% (95% CI 18.2% to 18.7%) of their lifetime sexual partners were paid. 3.6% (95% CI 3.1% to 4.2%) of men had paid for sex in the past 5 years. Partners of MPS constitute 14.7% of all reported partners and MPS report 15.6% of all reported STI diagnoses in the past 5 years. Paying for sex in the past 5 years was strongly associated with reporting larger numbers of sexual partners (adjusted OR, AOR for 5+ partners, past 5 years, 31.50, 95% CI 18.69 to 53.09). After adjusting for partner numbers, paying for sex remained strongly associated with reporting new foreign partners outside the UK (AOR 7.96; 95% CI 4.97 to 12.73) and STI diagnosis/es (AOR 2.34; 95% CI 1.44 to 3.81), all in the past 5 years. Among men ever paying for sex, 62.6% (95% CI 58.3% to 66.8%) reported paying for sex outside the UK, most often in Europe and Asia. Conclusions MPS in Britain remain at greater risk of STI acquisition and onward transmission than men who do not. They report high numbers of partners, but the minority are paid partners. They are an important core group in STI transmission

    Urginea capitata Baker - the berg slangkop, its toxic effects on ruminants, with a brief botanical survey of area

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    The green leaves proved poisonous when fed, mixed with lucerne, to cattle. The symptoms preceding death were " tucked up" appearance, sunken eyeballs, loss of appetite and profuse diarrhoea with blood stained faeces. The minimum fatal dose for an average sized animal is given as 6-8 lb. of the green material.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

    A Knob for Changing Light Propagation from Subluminal to Superluminal

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    We show how the application of a coupling field connecting the two lower metastable states of a lambda-system can produce a variety of new results on the propagation of a weak electromagnetic pulse. In principle the light propagation can be changed from subluminal to superluminal. The negative group index results from the regions of anomalous dispersion and gain in susceptibility.Comment: 6 pages,5 figures, typed in RevTeX, accepted in Phys. Rev.

    Thermal history of the string universe

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    Thermal history of the string universe based on the Brandenberger and Vafa's scenario is examined. The analysis thereby provides a theoretical foundation of the string universe scenario. Especially the picture of the initial oscillating phase is shown to be natural from the thermodynamical point of view. A new tool is employed to evaluate the multi state density of the string gas. This analysis points out that the well-known functional form of the multi state density is not applicable for the important region TTHT \leq T_H, and derives a correct form of it.Comment: 39 pages, no figures, use revtex.sty, aps.sty, aps10.sty & preprint.st

    The Effect of Including eHealth in Dietary Interventions for Patients with Type 2 Diabetes with Overweight or Obesity:A Systematic Review

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    eHealth has a growing impact on the delivery of healthcare, making health systems more efficient. This study examined the effect of dietary interventions using eHealth compared to face-to-face contact in patients with (pre-) type 2 diabetes (T2D) and who are overweight/obese. Literature databases were searched upon November 2022. Inclusion criteria: randomized controlled trial; duration ≥ 6 months; involving dietary interventions; performed in adults with (pre-) T2D and who are overweight/obese; using eHealth compared to face-to-face contact; and report outcomes on weight loss, glycemic regulation, and/or cost-effectiveness. Selection of articles was performed manually and using ASReviewLab. Fifteen studies were included for data extraction, investigating a wide variety of eHealth interventions. Seven studies reporting on weight loss showed a significant between-group difference (−1.18 to −5.5 kg); five studies showed a trend in favor of the eHealth programs. Eleven studies reported on HbA1c; three found a significant between-group difference (−0.23 to −0.70%) in favor of the eHealth programs and six studies showed non-significant improvements. Interaction with healthcare professionals led to better results of the dietary interventions. Two studies reported incomplete data on cost-effectiveness. In conclusion, eHealth shows better results of dietary interventions in (pre-) T2D patients compared to face-to-face, especially when combined with interaction with healthcare professionals.</p

    Systemic inflammation, coagulopathy, and acute renal insufficiency following endovascular thoracoabdominal aortic aneurysm repair

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    ObjectiveTo characterize the inflammatory and coagulopathic response after endovascular thoracoabdominal aortic aneurysm (TAAA) repair and to evaluate the effect of the response on postoperative renal function.MethodsFrom July 2005 to June 2008, 42 patients underwent elective endovascular repair of a TAAA using custom designed multi-branched stent-grafts at a single academic institution. Four patients were excluded from the analysis. White blood cell count (WBC), platelet count, prothrombin time (PT), and creatinine were measured in all patients. In the last nine patients, interleukin-6 (IL-6), protein C, Factor V, d-dimers, cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL) levels were also measured. Change in lab values were expressed as a percentage of baseline values.ResultsThe 30-day mortality rate was 5% (2/38). All patients (n = 38) had a higher WBC (mean ± SD: 139 ± 80%, P < .0001), lower platelet count (56 ± 15%, P < .0001), and higher PT (median: 17%, Interquartile range (IQR) 12%-22%, P < .0001) after stent-graft insertion. Twelve of 38 patients (32%) developed postoperative acute renal insufficiency (>50% rise in creatinine). Patients with renal insufficiency had significantly larger changes in WBC (178 ± 100% vs 121 ± 64%, P = .04) and platelet count (64 ± 17% vs 52 ± 12%, P = .02) compared with those without renal insufficiency. All patients (n = 9) had significant increases in NGAL (182 ± 115%, P = .008) after stent-graft insertion. Six of nine patients (67%) had increased cystatin C (35 ± 43%, P = .04) after stent-graft insertion, with a greater rise in those with postoperative renal insufficiency (87 ± 32% vs 8 ± 13%, P = .02). IL-6 levels were markedly increased in all patients (n = 9) after repair (9840 ± 6160%, P = .008). Protein C (35 ± 10%, P = .008) and Factor V levels (28 ± 20%, P = .008) were uniformly decreased, while d-dimers were elevated after repair in all patients (310 ± 213%, P = .008).ConclusionsLeukocytosis and thrombocytopenia were uniform following endovascular TAAA repair, and the severity of the response correlated with post-operative renal dysfunction. Elevation of a sensitive marker of renal injury (NGAL) suggests that renal injury may occur in all patients after stent-graft insertion

    Dispersive properties of quasi-phase-matched optical parametric amplifiers

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    The dispersive properties of non-degenerate optical parametric amplification in quasi-phase-matched (QPM) nonlinear quadratic crystals with an arbitrary grating profile are theoretically investigated in the no-pump-depletion limit. The spectral group delay curve of the amplifier is shown to be univocally determined by its spectral power gain curve through a Hilbert transform. Such a constraint has important implications on the propagation of spectrally-narrow optical pulses through the amplifier. In particular, it is shown that anomalous transit times, corresponding to superluminal or even negative group velocities, are possible near local minima of the spectral gain curve. A possible experimental observation of such effects using a QPM Lithium-Niobate crystal is suggested.Comment: submitted for publicatio

    Computational Method for Phase Space Transport with Applications to Lobe Dynamics and Rate of Escape

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    Lobe dynamics and escape from a potential well are general frameworks introduced to study phase space transport in chaotic dynamical systems. While the former approach studies how regions of phase space are transported by reducing the flow to a two-dimensional map, the latter approach studies the phase space structures that lead to critical events by crossing periodic orbit around saddles. Both of these frameworks require computation with curves represented by millions of points-computing intersection points between these curves and area bounded by the segments of these curves-for quantifying the transport and escape rate. We present a theory for computing these intersection points and the area bounded between the segments of these curves based on a classification of the intersection points using equivalence class. We also present an alternate theory for curves with nontransverse intersections and a method to increase the density of points on the curves for locating the intersection points accurately.The numerical implementation of the theory presented herein is available as an open source software called Lober. We used this package to demonstrate the application of the theory to lobe dynamics that arises in fluid mechanics, and rate of escape from a potential well that arises in ship dynamics.Comment: 33 pages, 17 figure
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