Study and analysis of state practices regarding the requirements for securing a driver's license

Thesis (M.A.)--Boston University, 1949. This item was digitized by the Internet Archive

Individuals With Disabilities Education Act: Guide and Toolkit (Book Review)

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Precision measurement of the top-quark mass in lepton+jets final states

This is the published version. Copyright © 2015 American Physical SocietyWe measure the mass of the top quark in lepton+jets final states using the full sample of pp¯ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at s√=1.96  TeV, corresponding to 9.7  fb−1 of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from tt¯ production or background. The overall jet energy scale is constrained in situ by the mass of the W boson. We measure mt=174.98±0.76  GeV. This constitutes the most precise single measurement of the top-quark mass

A Role of Early Life Stress on Subsequent Brain and Behavioral Development

The prevalence of pediatric neuropsychiatric disorders has risen dramatically during the past two decades. A study surveying the years 1997-2008 verified that one in six children have a developmental disability – a number on the rise. Along similar lines, studies show higher incidents of criminal activity, substance use disorders, and the emergence of psychopathologies in early adolescence and young adulthood, which are particularly sensitive periods of brain and behavioral maturation. While developmental trajectories that may lead to adverse outcomes in youth are the result of a mix of genetics and environmental exposure, it is becoming clearer that they do not start at the time of the diagnosis or problem behaviors; rather, these developmental trajectories start at the earliest periods of life. The ability of children to achieve their full physical, academic, and social potential is tightly related to early life events, some of which may occur even before birth. The science is now amassed with investigators and research targeting the role of Early Life Stress and its interaction with biological systems in impacting the development of the brain and complex behaviors across all stages of development

Group Gender Composition and Work Group Relations: Theories, Evidence, and Issues

[Excerpt] Prior to the publication of Kanter\u27s seminal Men and Women of the Corporation in 1977, the field of organizational studies exhibited a striking degree of oblivion to the effect of gender relations on work group dynamics. This neglect may have been due, in part, to the relatively small proportion of women in the labor force in the first half of the 20th century, as well as to high levels of occupational and job segregation, which helped conceal the influence of group gender composition on individual and group behavior. In the postwar years, however, women\u27s rate of entry into the labor force nearly doubled that of the preceding three decades, and women began to occupy many jobs and occupations that had been the near-exclusive province of men. In this context, Kanter\u27s provocative analysis of the impact of work group gender composition on group relations served as the impetus for an outpouring of both theoretical and empirical work. Studies following Kanter\u27s have explored the effects of gender composition on a wide range of outcomes, based on a variety of theoretical perspectives. In this chapter, we review five major theoretical paradigms that, singly or in combination, have provided the underpinning for most empirical studies, then review the findings from empirical work, focusing on the degree to which they provide support for each perspective. In concluding, we identify several avenues that merit greater attention in future research and theorizing

Estimating the incidence of colorectal cancer in Sub-Saharan Africa:A systematic analysis

Background Nearly two–thirds of annual mortality worldwide is attributable to non–communicable diseases (NCDs), with 70% estimated to occur in low– and middle–income countries (LMIC). Colorectal cancer (CRC) accounts for over 600 000 deaths annually, but data concerning cancer rates in LMIC is very poor. This study analyses the data available to produce an estimate of the incidence of colorectal cancer in Sub–Saharan Africa (SSA). Methods Data for this analysis came from two main sources: a systematic search of Medline, EMBASE and Global Health which found 15 published data sets, and an additional 42 unpublished data sets which were sourced from the IARC and individual cancer registries. Data for case rates by age and sex, as well as population denominators were extracted and analysed to produce an estimate of incidence. Results: The crude incidence of CRC in SSA for both sexes was found to be 4.04 per 100 000 population (4.38 for men and 3.69 for women). Incidence increased with age with the highest rates in Southern Africa, particularly in South Africa. The rates of CRC in SSA were much lower than those reported for high–income countries. Conclusion Few health services in SSA are equipped to provide timely diagnosis and treatment of cancer in SSA. In addition, data collection systems are weak, meaning that the available statistics may underestimate the burden of disease. In order to improve health care services it is vital that accurate measurements of disease burden are available to policy maker

Inclusive Production of the X(4140) State in pp¯ Collisions at D0

We present a study of the inclusive production of the X(4140) state with the decay to the J/ψϕ final state in hadronic collisions. Based on 10.4  fb−1 of pp¯ collision data collected by the D0 experiment at the Fermilab Tevatron collider, we report the first evidence for the prompt production of an X(4140) state and find the fraction of X(4140) events originating from b hadrons to be fb=0.39±0.07(stat)±0.10(syst). The ratio of the nonprompt X(4140) production rate to the B0s yield in the same channel is R=0.19±0.05(stat)±0.07(syst). The values of the mass M=4152.5±1.7(stat)+6.2−5.4(syst)  MeV and width Γ=16.3±5.6(stat)±11.4(syst)  MeV are consistent with previous measurements

Simultaneous measurement of forward-backward asymmetry and top polarization in dilepton final states from t¯t production at the Tevatron

We present a simultaneous measurement of the forward-backward asymmetry and the top-quark polarization in tt¯ production in dilepton final states using 9.7  fb−1 of proton-antiproton collisions at s√=1.96  TeV with the D0 detector. To reconstruct the distributions of kinematic observables we employ a matrix element technique that calculates the likelihood of the possible tt¯ kinematic configurations. After accounting for the presence of background events and for calibration effects, we obtain a forward-backward asymmetry of Att¯=(15.0±6.4(stat)±4.9(syst))% and a top-quark polarization times spin analyzing power in the beam basis of κP=(7.2±10.5(stat)±4.2(syst))%, with a correlation of −56% between the measurements. If we constrain the forward-backward asymmetry to its expected standard model value, we obtain a measurement of the top polarization of κP=(11.3±9.1(stat)±1.9(syst))%. If we constrain the top polarization to its expected standard model value, we measure a forward-backward asymmetry of Att¯=(17.5±5.6(stat)±3.1(syst))%. A combination with the D0 Att¯ measurement in the lepton+jets final state yields an asymmetry of Att¯=(11.8±2.5(stat)±1.3(syst))%. Within their respective uncertainties, all these results are consistent with the standard model expectations

Patterns and Trends in Cetacean Occurrence Revealed by Shorewatch, a Land-Based Citizen Science Program in Scotland (United Kingdom)

Shorewatch is a citizen science project, managed by Whale and Dolphin Conservation (WDC), that records the occurrence of cetaceans during regular, standardized watches from a series of locations along the coast of Scotland (United Kingdom). Observer training and a clearly defined protocol help deliver a valuable source of information about cetacean occurrence and activity along the coast. Between 2005–2018, over 52000 watches generated over 11000 sightings of at least 18 cetacean species. Generalized Additive Models based on sightings for the five most commonly sighted species (bottlenose dolphin, harbor porpoise, minke whale, Risso’s dolphin, and common dolphin), at those sites with the longest time series, demonstrated seasonal, geographical and year-to-year differences in their local occurrence and relative abundance. Bottlenose dolphins are mainly present at observation sites located on the east coast of Scotland, being uncommon on the west coast, while harbor porpoise and minke whale are principally present at sites located on the west coast. The seasonality observed in cetacean occurrence is consistent with peak abundance in summer months described by previous studies in the area. Mean depth around the observation sites is the static variable that apparently has the greatest influence on species presence and number of sightings, except for Risso’s dolphin. All the species except bottlenose dolphin showed upward trends in occurrence and number of sightings over the period 2012–2018. Evidence of temporal autocorrelation was found between results from consecutive watches at the same site on the same day as well as between results from consecutive days at the same site. The power to detect declines in local abundance over a 6-year period depends on the underlying sighting rate of each cetacean species, the number of watches performed and the rate of decline. Simulations performed to determine the power to detect a decline suggest that the current intensity of observation effort in some observation sites, of about 2500 watches per year, may offer good prospects of detecting a 30% decline of the most frequently sighted species (95% of the time) over a 6-year period, although a more even distribution of observation effort in space and time is desirable. The data could potentially be used for monitoring and 6-yearly reporting of the status of cetacean populations.En prens

Measurement of the B0s Lifetime in the Flavor-Specific Decay Channel B0s→D−sμ+νX

We present an updated measurement of the B0s lifetime using the semileptonic decays B0s→D−sμ+νX, with D−s→ϕπ− and ϕ→K+K− (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at s√=1.96  TeV, comprising an integrated luminosity of 10.4  fb−1. We find a flavor-specific lifetime τfs(B0s)=1.479±0.010(stat)±0.021(syst)  ps. This technique is also used to determine the B0 lifetime using the analogous B0→D−μ+νX decay with D−→ϕπ− and ϕ→K+K−, yielding τ(B0)=1.534±0.019(stat)±0.021(syst)  ps. Both measurements are consistent with the current world averages, and the B0s lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio τfs(B0s)/τ(B0)=0.964±0.013(stat)±0.007(syst)