Will Job Testing Harm Minority Workers?

Because minorities typically fare poorly on standardized tests, job testing is thought to pose an equity-efficiency trade-off: testing improves selection but reduces minority hiring. We develop a conceptual framework to assess when this tradeoff is likely to apply and evaluate the evidence for such a trade-off using data from a national retail firm whose 1,363 stores switched from informal to test-based worker screening over the course of on year. We document that testing yielded more productive hires at this firm -- raising median tenure by 10-plus percent. Consistent with prior research, minorities performed worse on the test. Yet, testing had no measurable impact on minority hiring, and productivity gains were uniformly large among minorities and non-minorities. These results suggest that job testing raised the precision of screening without introducing additional negative information about minority applicants, most plausibly because both the job test and the informal screen that preceded it were unbiased.

Preston Brooks

A reproduction of a portrait of Preston Brooks.The print is accompanied by protective paper with caption.https://scholarsjunction.msstate.edu/fvw-artifacts/4614/thumbnail.jp

Systematic review and meta-analysis of reduction in all-cause mortality from walking and cycling and shape of dose response relationship

BACKGROUND AND OBJECTIVE: Walking and cycling have shown beneficial effects on population risk of all-cause mortality (ACM). This paper aims to review the evidence and quantify these effects, adjusted for other physical activity (PA). DATA SOURCES: We conducted a systematic review to identify relevant studies. Searches were conducted in November 2013 using the following health databases of publications: Embase (OvidSP); Medline (OvidSP); Web of Knowledge; CINAHL; SCOPUS; SPORTDiscus. We also searched reference lists of relevant texts and reviews. STUDY ELIGIBILITY CRITERIA AND PARTICIPANTS: Eligible studies were prospective cohort design and reporting walking or cycling exposure and mortality as an outcome. Only cohorts of individuals healthy at baseline were considered eligible. STUDY APPRAISAL AND SYNTHESIS METHODS: Extracted data included study population and location, sample size, population characteristics (age and sex), follow-up in years, walking or cycling exposure, mortality outcome, and adjustment for other co-variables. We used random-effects meta-analyses to investigate the beneficial effects of regular walking and cycling. RESULTS: Walking (18 results from 14 studies) and cycling (8 results from 7 studies) were shown to reduce the risk of all-cause mortality, adjusted for other PA. For a standardised dose of 11.25 MET.hours per week (or 675 MET.minutes per week), the reduction in risk for ACM was 11% (95% CI = 4 to 17%) for walking and 10% (95% CI = 6 to 13%) for cycling. The estimates for walking are based on 280,000 participants and 2.6 million person-years and for cycling they are based on 187,000 individuals and 2.1 million person-years. The shape of the dose-response relationship was modelled through meta-analysis of pooled relative risks within three exposure intervals. The dose-response analysis showed that walking or cycling had the greatest effect on risk for ACM in the first (lowest) exposure interval. CONCLUSIONS AND IMPLICATIONS: The analysis shows that walking and cycling have population-level health benefits even after adjustment for other PA. Public health approaches would have the biggest impact if they are able to increase walking and cycling levels in the groups that have the lowest levels of these activities. REVIEW REGISTRATION: The review protocol was registered with PROSPERO (International database of prospectively registered systematic reviews in health and social care) PROSPERO 2013: CRD42013004266

Residual Stress, Mechanical Behavior and Electrical Properties of Cu/Nb Thin-Film Multilayers

Effect of compositional wavelength (modulation) on residual stress, electrical resistivities and mechanical properties of Cu/Nb thin-film multilayers sputtered onto single-crystal Si substrates, was evaluated. Electrical resistivities were measured down to 4 K using a standard 4-point probe. Differential specimen curvature was used to determine residual stress, and a microprobe was used to obtain hardness and elastic modulus. Profilometry, ion-beam analysis and TEM were used. Hardness of the Cu-Nb multilayers increased with decreasing compositional wavelength so that the layered structures had hardness values in excess of either constituent and the hardness predicted by the rule of mixtures. A peak in net residual compressive stress of the multilayers was observed at a compositional wavelength of 100 nm. No resistivity plateau was observed within the composition wavelength range studied

Erratum to: systematic review and meta-analysis of the effect of increased vegetable and fruit consumption on body weight and energy intake

There were some errors in the original published article [1]. Firstly relating to the calculation of the confidence intervals for four of the studies included in the meta-analysis, [2, 3, 4, 5] which are detailed below. Secondly one of the papers, Whybrow et al. was incorrectly cited as being published in 2007, when it was published in 2006 [2]

Modelling Future Coronary Heart Disease Mortality to 2030 in the British Isles.

OBJECTIVE: Despite rapid declines over the last two decades, coronary heart disease (CHD) mortality rates in the British Isles are still amongst the highest in Europe. This study uses a modelling approach to compare the potential impact of future risk factor scenarios relating to smoking and physical activity levels, dietary salt and saturated fat intakes on future CHD mortality in three countries: Northern Ireland (NI), Republic of Ireland (RoI) and Scotland. METHODS: CHD mortality models previously developed and validated in each country were extended to predict potential reductions in CHD mortality from 2010 (baseline year) to 2030. Risk factor trends data from recent surveys at baseline were used to model alternative future risk factor scenarios: Absolute decreases in (i) smoking prevalence and (ii) physical inactivity rates of up to 15% by 2030; relative decreases in (iii) dietary salt intake of up to 30% by 2030 and (iv) dietary saturated fat of up to 6% by 2030. Probabilistic sensitivity analyses were then conducted. RESULTS: Projected populations in 2030 were 1.3, 3.4 and 3.9 million in NI, RoI and Scotland respectively (adults aged 25-84). In 2030: assuming recent declining mortality trends continue: 15% absolute reductions in smoking could decrease CHD deaths by 5.8-7.2%. 15% absolute reductions in physical inactivity levels could decrease CHD deaths by 3.1-3.6%. Relative reductions in salt intake of 30% could decrease CHD deaths by 5.2-5.6% and a 6% reduction in saturated fat intake might decrease CHD deaths by some 7.8-9.0%. These projections remained stable under a wide range of sensitivity analyses. CONCLUSIONS: Feasible reductions in four cardiovascular risk factors (already achieved elsewhere) could substantially reduce future coronary deaths. More aggressive polices are therefore needed in the British Isles to control tobacco, promote healthy food and increase physical activity

Validity of a Protocol for Adult Self-Report of Dyslexia and Related Difficulties

Background: There is an increased prevalence of reading and related difficulties in children of dyslexic parents. In order to understand the causes of these difficulties, it is important to quantify the risk factors passed from parents to their offspring. Method: 417 adults completed a protocol comprising a 15-item questionnaire rating reading and related skills and a scale assessing ADHD symptoms; 344 completed reading, nonword reading and spelling tests. Results: A confirmatory factor analysis with four factors (Reading, Word Finding, Attention and Hyperactivity) provided a reasonable fit to the data. The Reading Factor showed robust correlations with measured literacy skills. Adults who reported as dyslexic, or rated their reading difficulties as more severe, gained lower scores on objective measures of literacy skills. Although the sensitivity of the new scale was acceptable, it tended to miss some cases of low literacy. Conclusions: Self-report scales of reading and of attention difficulties are useful for identifying adults with reading and attention difficulties which may confer risks on their children of related problems. It is important for research following children at family risk of dyslexia to be aware of these effects

Associated reading skills in children with a history of Specific Language Impairment (SLI)

A large cohort of 200 eleven-year-old children with Specific Language Impairment (SLI) were assessed on basic reading accuracy and on reading comprehension as well as language tasks. Reading skills were examined descriptively and in relation to early language and literacy factors. Using stepwise regression analyses in which age and nonverbal IQ were controlled for, it was found that a single word reading measure taken at 7 years was unsurprisingly a strong predictor of the two different types of reading ability. However, even with this measure included, a receptive syntax task (TROG) entered when reading accuracy score was the DV. Furthermore, a test of expressive syntax/narrative and a receptive syntax task completed at 7 years entered into the model for word reading accuracy. When early reading accuracy was excluded from the analyses, early phonological skills also entered as a predictor of both reading accuracy and comprehension at 11 years. The group of children with a history of SLI were then divided into those with no literacy difficulties at 11 and those with some persisting literacy impairment. Using stepwise logistic regression, and again controlling for IQ and age, 7 years receptive syntax score (but not tests of phonology, expressive vocabulary or expressive syntax/narrative) entered as a positive predictor of membership of the ‘no literacy problems’ group regardless of whether early reading accuracy was controlled for in step one. The findings are discussed in relation to the overlap of SLI and dyslexia and the long term sequelae of language impairment

Development of a Thin-Film Solar Cell Interconnect for the Powersphere Concept

Dual junction amorphous silicon (a-Si) solar cells produced on polyimide substrate have been selected as the best candidate to produce a lightweight solar array for the PowerSphere program. The PowerSphere concept features a space-inflatable, geodetic solar array approximately 0.6 meters in diameter and capable of generating about 20W of electrical power. Trade studies of various wiring concepts and connection methods led to an interconnect design with a copper contact that wraps around the edge, to the back of the solar cell. Applying Plasma Vapor Deposited (PVD) copper film to both sides and the edge of the solar cell produces the wrap around contact. This procedure results in a contact pad on the back of the solar cell, which is then laser welded to a flex circuit material. The flex circuit is constructed of copper in a custom designed routing pattern, and then sandwiched in a Kapton insulation layer. The flex circuit then serves as the primary power distribution system between the solar cells and the spacecraft. Flex circuit material is the best candidate for the wiring harness because it allows for low force deployment of the solar cells by the inflatable hinges on the PowerSphere. An additional frame structure, fabricated and assembled by ILC Dover, will reinforce the wrap around contact-flex blanket connection, thus providing a mechanically robust solar cell interconnect for the PowerSphere multifunctional program. The PowerSphere team will use the wraparound contact design approach as the primary solution for solar cell integration and the flex blanket for power distribution