2,858 research outputs found
Education Reform and the Limits of Policy: Lessons from Michigan
By examining a major set of education policy reforms undertaken in Michigan and across the country over the past 20-plus years, Addonizio and Kearney are able to reveal the varying success of innovations such as finance reform, state assessment of student performance, school accountability measures, charter schools, and schools of choice.https://research.upjohn.org/up_press/1234/thumbnail.jp
Modelling gold futures: should the level of speculation inform our choice of variables?
Prior literature provides conflicting evidence about the impact of speculation on gold futures returns, volatility, and the relationship between market fundamentals and prices. In this paper, we exploit trade volume information to determine the most appropriate family of factors to adopt when modelling gold futures. Using the Disaggregated Commitment of Traders report, we find that extreme levels of speculation are informative in that they signify a shift in the relative modelling accuracy of macroeconomic and latent factors. A simple composite prediction framework, incorporating the changing level of speculation, empirically demonstrates the uncovered phenomenon and offers improved predictive accuracy for gold futures prices. Furthermore, our findings are shown to be robust to alternative latent and macroeconomic model specifications
Teacher Quality and Sorting across Traditional Public and Charter Schools in the Detroit Metropolitan Region
In the quest to raise student achievement in low-performing urban schools, researchers often point to the central importance of recruitment and retention of a high quality teacher workforce
Concordance rate between copy number variants detected using either high- or medium-density single nucleotide polymorphism genotype panels and the potential of imputing copy number variants from flanking high density single nucleotide polymorphism haplotypes in cattle
peer-reviewedBackground
The trading of individual animal genotype information often involves only the exchange of the called genotypes and not necessarily the additional information required to effectively call structural variants. The main aim here was to determine if it is possible to impute copy number variants (CNVs) using the flanking single nucleotide polymorphism (SNP) haplotype structure in cattle. While this objective was achieved using high-density genotype panels (i.e., 713,162 SNPs), a secondary objective investigated the concordance of CNVs called with this high-density genotype panel compared to CNVs called from a medium-density panel (i.e., 45,677 SNPs in the present study). This is the first study to compare CNVs called from high-density and medium-density SNP genotypes from the same animals. High (and medium-density) genotypes were available on 991 Holstein-Friesian, 1015 Charolais, and 1394 Limousin bulls. The concordance between CNVs called from the medium-density and high-density genotypes were calculated separately for each animal. A subset of CNVs which were called from the high-density genotypes was selected for imputation. Imputation was carried out separately for each breed using a set of high-density SNPs flanking the midpoint of each CNV. A CNV was deemed to be imputed correctly when the called copy number matched the imputed copy number.
Results
For 97.0% of CNVs called from the high-density genotypes, the corresponding genomic position on the medium-density of the animal did not contain a called CNV. The average accuracy of imputation for CNV deletions was 0.281, with a standard deviation of 0.286. The average accuracy of imputation of the CNV normal state, i.e. the absence of a CNV, was 0.982 with a standard deviation of 0.022. Two CNV duplications were imputed in the Charolais, a single CNV duplication in the Limousins, and a single CNV duplication in the Holstein-Friesians; in all cases the CNV duplications were incorrectly imputed.
Conclusion
The vast majority of CNVs called from the high-density genotypes were not detected using the medium-density genotypes. Furthermore, CNVs cannot be accurately predicted from flanking SNP haplotypes, at least based on the imputation algorithms routinely used in cattle, and using the SNPs currently available on the high-density genotype panel
Book Reviews
Book reviews by Leon L. Lancaster, Jr., Jack C. Hynes, James J. Kearney, Joseph F. Nigro, Louis P. Da Pra, and Francis Bright
Management of mesh complications following surgery for stress urinary incontinence or pelvic organ prolapse: a systematic review
Background:
Mesh surgery for stress urinary incontinence or pelvic organ prolapse can result in complications such as mesh exposure, mesh extrusion, voiding dysfunction, dyspareunia, and pain. There is limited knowledge or guidance on the effective management for mesh‐related complications.
Objective:
To determine the best management of mesh complications; a systematic review was conducted as part of the national clinical guideline ‘Urinary incontinence (update) and pelvic organ prolapse in women: management’.
Search strategy:
Search strategies were developed for each indication for referral.
Selection criteria:
Relevant interventions included complete or partial mesh removal, mesh division, and non‐surgical treatments such as vaginal estrogen.
Data collection and analysis:
Characteristics and outcome data were extracted, and as a result of the heterogeneous nature of the data a narrative synthesis was conducted.
Main results:
Twenty‐four studies were included; five provided comparative data and four studies stated the indication for referral. Reported outcomes (including pain, dyspareunia, satisfaction, quality of life, incontinence, mesh exposure, and recurrence) and the reported incidences of these varied widely.
Conclusions:
The current evidence base is limited in quantity and quality and does not permit firm recommendations to be made on the most effective management for mesh‐related complications. Robust data are needed so that mesh complications can be managed effectively in the future
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Effectiveness of physical activity interventions for overweight and obesity during pregnancy: a systematic review of the content of behaviour change interventions
Background
Behaviour change techniques (BCTs) employed within PA intervention for pregnant women with a healthy body mass index (BMI) have been previously identified, however, these BCTS may differ for other weight profiles during pregnancy. The aim of this current review was to identify and summarise the evidence for effectiveness of PA interventions on PA levels for pregnant women with overweight and obesity, with an emphasis on the BCTs employed.
Methods
A systematic review and meta-analysis of PA intervention studies using the PRISMA statement was conducted. Searches were conducted of eight databases in January 2019. Strict inclusion/exclusion criteria were employed. The validity of each included study was assessed using the Cochrane Collaboration’s tool for assessing risk of bias. The primary outcome measure was change in PA levels, subjectively or objectively measured, with physical fitness as a secondary outcome. All intervention descriptions were double coded by two authors using Michie’s et al’s BCT taxonomy V1. Meta-analyses using random effect models assessed the intervention effects on PA. Other PA outcomes were summarised in a narrative synthesis.
Results
From 8389 studies, 19 met the inclusion criteria 13 of which were suitable for inclusion in a meta-analysis. The remaining 6 studies were described narratively due to insufficient data and different outcome measures reported. In the meta-analysis, comparing interventions to a control group, significant increases were found in the intervention group for metabolic equivalent (SMD 0.39 [0.14, 0.64], Z = 3.08 P = 0.002) and physical fitness (VO2 max) (SMD 0.55 [0.34, 0.75], Z = 5.20 P = < 0.001). Of the other six, five studies reported an increase in PA for the intervention group versus the control with the other study reporting a significant decrease for women in their 3rd trimester (p = 0.002). ‘Self-monitoring of behaviour’ was the most frequently used BCTs (76.5%), with ‘social support’ being newly identified for this pregnant population with overweight or obesity.
Conclusions
This review identified a slight increase in PA for pregnant women with overweight and obesity participating in interventions. However, due to the high risk of bias of the included studies, the results should be interpreted with caution. PA measures should be carefully selected so that studies can be meaningfully compared and standardised taxonomies should be used so that BCTs can be accurately assessed
Increased gravitational force reveals the mechanical, resonant nature of physiological tremor
Human physiological hand tremor has a resonant component. Proof of this is that its frequency can be modified by adding mass. However, adding mass also increases the load which must be supported. The necessary force requires muscular contraction which will change motor output and is likely to increase limb stiffness. The increased stiffness will partly offset the effect of the increased mass and this can lead to the erroneous conclusion that factors other than resonance are involved in determining tremor frequency. Using a human centrifuge to increase head-to-foot gravitational field strength, we were able to control for the increased effort by increasing force without changing mass. This revealed that the peak frequency of human hand tremor is 99% predictable on the basis of a resonant mechanism. We ask what, if anything, the peak frequency of physiological tremor can reveal about the operation of the nervous system.This work was funded by a BBSRC Industry Interchange Award
to J.P.R.S. and R.F.R. C.J.O. was funded by BBSRC grant
BB/I00579X/1. C.A.V. was funded by A∗Midex (Aix-Marseille
Initiative of Excellence
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