4,901 research outputs found
Compounded Disadvantage: Race, Incarceration, and Wage Growth
Based on 14-year panel data on ex-prisoners, this paper reports the impact of incarceration on future job prospects. Black men, in addition to facing greater risk of ending up in prison, are more negatively affected by imprisonment than white men. The expansion of the U.S. criminal justice system is therefore responsible for compounding the disadvantages of African Americans
Laer-induced Breakdown Spectroscopy Instrument for Element Analysis of Planetary Surfaces
One of the most fundamental pieces of information about any planetary body is the elemental and mineralogical composition of its surface materials. We are developing an instrument to obtain such data at ranges of up to several hundreds of meters using the technique of Laser-Induced Breakdown Spectroscopy (LIBS). We envision our instrument being used from a spacecraft in close rendezvous with small bodies such as comets and asteroids, or deployed on surface-rover vehicles on large bodies such as Mars and the Moon. The elemental analysis is based on atomic emission spectroscopy of a laser-induced plasma or spark. A pulsed, diode pumped Nd:YAG laser of several hundred millijoules optical energy is used to vaporize and electronically excite the constituent elements of a rock surface remotely located from the laser. Light emitted from the excited plasma is collected and introduced to the entrance slit of a small grating spectrometer. The spectrally dispersed spark light is detected with either a linear photo diode array or area CCD array. When the latter detector is used, the optical and spectrometer components of the LIBS instrument can also be used in a passive imaging mode to collect and integrate reflected sunlight from the same rock surface. Absorption spectral analysis of this reflected light gives mineralogical information that provides a remote geochemical characterization of the rock surface. We performed laboratory calibrations in air and in vacuum on standard rock powders to quantify the LIBS analysis. We performed preliminary field tests using commercially available components to demonstrate remote LIBS analysis of terrestrial rock surfaces at ranges of over 25 m, and we have demonstrated compatibility with a six-wheeled Russian robotic rover vehicle. Based on these results, we believe that all major and most minor elements expected on planetary surfaces can be measured with absolute accuracy of 10-15 percent and much higher relative accuracy. We have performed preliminary systems analysis of a LIBS instrument to evaluate probable mass and power requirements; results of this analysis are summarized
A New Interpretation for the Second Peak of T Coronae Borealis Outbursts: A Tilting Disk around a Very Massive White Dwarf
A new interpretation for the second peak of T Coronae Borealis (T CrB)
outbursts is proposed based on a thermonuclear runaway (TNR) model. The system
consists of a very massive white dwarf (WD) with a tilting accretion disk and a
lobe-filling red-giant. The first peak of the visual light curve of T CrB
outbursts is well reproduced by the TNR model on a WD close to the
Chandrasekhar mass (), while the second peak
is reproduced by the combination of the irradiated M-giant and the irradiated
tilting disk. The derived fitting parameters are the WD mass , the M-giant companion mass
( is acceptable), the inclination angle of the orbit i \sim
70 \arcdeg, and the tilting angle of the disk i_{\rm prec} \sim 35 \arcdeg.
These parameters are consistent with the recently derived binary parameters of
T CrB.Comment: 6 pages including 2 figures, to be published in ApJ Letter
Identifying Situational Constraints to Focus Quality Improvement in an Air Force Aerial Port
This research analyzes the effects of situational constraints on individual performance within an Air Force Aerial Port squadron. Situational constraint research originated with laboratory studies by Peters and O\u27Connor in 1980 and was investigated in an Air Force field environment in 1984; mixed results were obtained. Laboratory studies identified direct performance inhibitors (Peters et al., 1980); however, field studies found little correlations with job performance (Kane, 1981; O\u27Connor et al., 1984a). Data collected in June 1995 (Dougherty, 1995) and March 1996, in this study, were used to accomplish a longitudinal analysis. Correlations between constraints and performance were also low in this study; however, significant reductions in constraints were identified in 12 of the 14 work groups investigated. Results suggest that O\u27Connor et al.\u27s measure (1984a) may be useful in identifying bottlenecks requiring managerial actions
HOW CAN ADVERSE EVENTS INFORMATION BE USED TO MORE EFFECTIVELY INFORM CANCER PATIENT CARE?
Due to advances in screening and therapy design, cancer patients are living longer while on or following therapy. Therapy-related adverse events (AEs) are an unintended, but not infrequent, outcome of these treatments. AEs can impact quality of life, adherence to therapy, economic status, and treatment decision-making. This novel qualitative study is the first to undertake a multi-stakeholder evaluation of the impact of AE information on informing cancer patient care in the context of extended survival. The evaluation focuses on a growing subset of cancer patients – those receiving adjuvant therapy. Adjuvant therapies, used to manage many common cancers, lower the risk that the cancer will return. In this setting, mediating the impact of potential acute or delayed adjuvant treatment-related AEs relative to an uncertain potential for tumor recurrence presents important challenges in balancing risks versus benefits. Stakeholder perspectives on generating, disseminating, and/or adjuvant treatment-related AE information were elicited via key informant interviews with patient advocacy, clinical care, regulatory, drug development, and healthcare payer representatives. The stakeholders identified future needs in four key areas: 1) information resources, 2) information integration and implementation, 3) value systems and culture, and 4) alignment and ownership of collective efforts to improve the use of AE information in the adjuvant setting. This study revealed the following novel insights: 1) there is cross-stakeholder agreement that change is needed to improve the use of AE information in the adjuvant setting to improve patient outcome, 2) the directionality of needed changes are similar across stakeholders, although specific priorities varied, and 3) the potential to realize broad systemic progress in the use of adjuvant-related AE information is a challenge that lacks clear ownership. This lack of ownership has adversely impacted resourcing, efficiency, and collective progress and is likely to be a progress-limiting factor in realizing transformational change. To address the system-limiting challenges identified in this research, a proposed approach to incentivize and support stakeholders in forward action is offered. The proposal offers an infrastructure to promote collaborative and independent efforts in fulfillment of the many scientific, economic, communication, social, and implementation challenges identified in this research study.Doctor of Public Healt
Affirmative action in higher education: A legal analysis of the use of race as a factor in college admissions after Bakke
The purpose of this dissertation was to examine the legal status of affirmative action in higher education admission policies with regard to the use of race as a factor. This study answered these three questions:;What is the current status of the Regents of the University of California v. Bakke decision as a basis for assessing higher education admission policies? What legal benchmarks have emerged since the Bakke decision which may impact the development of university admission policies? What policies may achieve diversity in higher education admissions without incurring legal risks by using race and ethnicity in the admissions policies?;The significance of this study was found in examining the law cases concerned with affirmative action using race as a factor in higher education admissions policies. This study attempted to make it easier for educators to understand affirmative action and to be a resource guide with which higher education administrators may make informed decisions on the legal aspects of admissions policies; This dissertation used an analytical, qualitative research design. As a legal/historical analysis, it included search, selection and criticism of the sources, presentation of the facts and generalizations, and use of inductive case law analysis. Law cases were examined for their usage of Bakke as a precedent as to whether the opinions in Bakke were followed or criticized; The majority of the cases examined followed Bakke as a precedent. However, because of the legal risks taken when using race as a factor in college admissions, other avenues of promoting diversity in the student body were also explored
Constrained action selection in children with developmental coordination disorder
The effect of advance (‘precue’) information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n = 10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic
Development of aluminum alloy compounds for electroluminescent light sources
Aluminum alloy compounds as wide band gap semiconductors for electroluminescent light source
Meltwater Intrusions Reveal Mechanisms for Rapid Submarine Melt at a Tidewater Glacier
Submarine melting has been implicated as a driver of glacier retreat and sea level rise, but to date melting has been difficult to observe and quantify. As a result, melt rates have been estimated from parameterizations that are largely unconstrained by observations, particularly at the near-vertical termini of tidewater glaciers. With standard coefficients, these melt parameterizations predict that ambient
melting (the melt away from subglacial discharge outlets) is negligible compared to discharge-driven melting for typical tidewater glaciers. Here, we present new data from LeConte Glacier, Alaska, that challenges this paradigm. Using autonomous kayaks, we observe ambient meltwater intrusions that are ubiquitous within 400 m of the terminus, and we provide the first characterization of their properties, structure, and distribution. Our results suggest that ambient melt rates are substantially higher (×100) than standard theory predicts and that ambient melting is a significant part of the total submarine melt flux. We explore modifications to the prevalent melt parameterization to provide a path forward for improved modeling of ocean-glacier interactions.This work was funded by NSF OPP Grants 1503910, 1504191, 1504288,
and 1504521 and National Geographic Grant CP4-171R-17. Additionally, this research was supported by the NOAA Climate and Global Change Postdoctoral Fellowship Program, administered by UCAR’s Cooperative Programs for the Advancement of Earth System Science (CPAESS) under award #NA18NWS4620043B. These observations would not be possible without the skilled engineering team who developed the autonomous kayaks—including Jasmine Nahorniak, June Marion, Nick McComb, Anthony Grana, and Corwin Perren—and also the Captain and crew of the M/V Amber Anne. We thank Donald Slater and an anonymous reviewer for valuable feedback that improved this manuscript. Data availability: All of the oceanographic data collected by ship and kayak have been archived with the National Centers for Environmental Information (Accession 0189574, https://accession.nodc.noaa.gov/ 0189574). The glacier data have been archived at the Arctic Data Center (https://doi.org/10.18739/A22G44).Ye
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