2,880 research outputs found
Aging Out of the Foster Care System to Adulthood: Findings, Challenges, and Recommendations
To assess and ultimately help meet the needs of youth who age out of foster care in the United States, the Joint Center Health Policy Institute (JCHPI) -- with support from the Robert Wood Johnson Foundation and in partnership with the Black Administrators in Child Welfare Inc. (BACW) -- conducted reconnaissance on the unmet needs of these youth. This project was undertaken to guide the Robert Wood Johnson Foundation in thinking about steps they might take to help meet the needs of youth who age out of foster care in this country. Conducting a literature review, a telephone survey, and listening sessions enabled us to develop insights into the workings of the foster care system and the experiences of youth while in the system and when aging out of it
Avoiding shipper/consignee double payment liability
The purpose of this article is neither to engage in an overly technical legal analysis nor to disparage motor carriers who bring “double liability” claims against financially viable shippers/consignees; after all the trucking company has performed a valuable service and is simply trying to be paid “once” for that service - even though the financially viable shipper or consignee may have to pay twice with the bankrupt/insolvent third party absconding. The purpose of this article is generally to provide some “front-end” practical suggestions to shippers/ consignees in how to avoid being in court on one of these claims in the first place and more specifically how to do so by exercising due diligence in selecting a freight broker for transportation needs
Choice of State of Incorporation - Texas versus Delaware: Is It Now Time to Rethink Traditional Notions
Interpretation of Light-Quenching Factor Measurements
We observe that the pattern of the quenching factors for scintillation light
from various ions, recently studied in in connection with dark matter
detectors, can be understood as a saturation phenomenon in which the light
output is simply proportional to track length, independent of the ion and its
energy. This observation is in accord with the high dE/dx limit of Birks' law.
It suggests a simple model for the intrinsic resolution of light detectors for
low energy ions, which we briefly discuss.Comment: Seven pages, seven figures, some with colo
New Technology for Shallow Water Hydrographic Surveys
The United States Office of Coast Survey is developing technology for shallow water hydrographic surveys in order to increase the efficiency with which hydrographic data are acquired and to improve the likelihood that all potential dangers to navigation are detected in the course of a hydrographic survey. Three areas of technology hold the greatest promise for meeting those goals: Airborne Lidar Hydrography (ALH), Shallow Water Multibeam Sonars (SWMB), and digital side scan sonar, especially the Coast Survey’s new High Speed, High Resolution Side Scan Sonar (HSHRSSS). The Coast Survey expects that all its ALH surveys will be outsourced to private sector contractors, and that its SWMB and side scan sonar surveys will be accomplished by both NOAA survey vessels and by private sector contractors. This diversity of sources for survey data influences the strategy for managing these new technologies
Achieving High Performance in Local Government: Linking Government Outcomes with Human Resource Management Practices
Historically public sector personnel policies and practices have been targets of reform. These reforms consisted of transferring private sector techniques to a public sector perceived to be more bureaucratic and less efficient. Private sector research is replete with evidence of a connection between superior human resource management (HRM) practices and the performance outcome of profitability. Public sector outcomes are more difficult to connect directly to management practices. As a result, the focus of public sector reform has become one of improving the processes of management rather than improving the outcomes of government. The linkage between reform and outcome is assumed.This study attempts to add to the literature by tying local government HRM practices to the organization level performance outcome of un-enhanced general obligation municipal bond rating. A database was obtained from the International City/County Management Association (ICMA) containing the results of an HRM survey in 2000 of all U.S. municipalities with a population over 10,000. The municipal bond rating was then used as a performance proxy and dependent variable; the greater the number of high performing HRM practices employed by a municipality, the higher the bond rating or the higher the performance. The study sample consisted of 366 municipalities both responding to the survey and with bond ratings meeting the criteria of the study. The results of a binary logistic regression analysis showed intensive recruitment, family oriented work practices, job flexibility and open communication to be strong predictors of high performance. Decentralized HRM decisions, pay for performance programs and incentives for group participation were not associated with high performance. These findings suggest municipalities are likely to improve their performance by implementing the practices found to be predictive of higher bond ratings. However, differences between private and public sectors need to be considered when implementing change and a systems view helps minimize deadly combinations and maximize powerful connections . Also, organization culture and the structure of the HRM system need to be considered. Additional research is recommended to further develop and validate the use of the municipal bond rating as a measure of a government level performance outcome
The Splashback Feature around DES Galaxy Clusters: Galaxy Density and Weak Lensing Profiles
Splashback refers to the process of matter that is accreting onto a dark matter halo reaching its first orbital apocenter and turning around in its orbit. The clustercentric radius at which this process occurs, r_(sp), defines a halo boundary that is connected to the dynamics of the cluster. A rapid decline in the halo profile is expected near r_(sp). We measure the galaxy number density and weak lensing mass profiles around REDMAPPER galaxy clusters in the first-year Dark Energy Survey (DES) data. For a cluster sample with mean M_(200m) mass ≈2.5 × 10^(14) M⊙, we find strong evidence of a splashback-like steepening of the galaxy density profile and measure r_(sp) = 1.13 ± 0.07 h^(−1) Mpc, consistent with the earlier Sloan Digital Sky Survey measurements of More et al. and Baxter et al. Moreover, our weak lensing measurement demonstrates for the first time the existence of a splashback-like steepening of the matter profile of galaxy clusters. We measure r_(sp) = 1.34 ± 0.21 h^(−1) Mpc from the weak lensing data, in good agreement with our galaxy density measurements. For different cluster and galaxy samples, we find that, consistent with ΛCDM simulations, r_(sp) scales with R_(200m) and does not evolve with redshift over the redshift range of 0.3–0.6. We also find that potential systematic effects associated with the REDMAPPER algorithm may impact the location of r_(sp). We discuss the progress needed to understand the systematic uncertainties and fully exploit forthcoming data from DES and future surveys, emphasizing the importance of more realistic mock catalogs and independent cluster samples
Space Radiation Effects on Human Cells: Modeling DNA Breakage, DNA Damage Foci Distribution, Chromosomal Aberrations and Tissue Effects
Future long-tem space travel will face challenges from radiation concerns as the space environment poses health risk to humans in space from radiations with high biological efficiency and adverse post-flight long-term effects. Solar particles events may dramatically affect the crew performance, while Galactic Cosmic Rays will induce a chronic exposure to high-linear-energy-transfer (LET) particles. These types of radiation, not present on the ground level, can increase the probability of a fatal cancer later in astronaut life. No feasible shielding is possible from radiation in space, especially for the heavy ion component, as suggested solutions will require a dramatic increase in the mass of the mission. Our research group focuses on fundamental research and strategic analysis leading to better shielding design and to better understanding of the biological mechanisms of radiation damage. We present our recent effort to model DNA damage and tissue damage using computational models based on the physics of heavy ion radiation, DNA structure and DNA damage and repair in human cells. Our particular area of expertise include the clustered DNA damage from high-LET radiation, the visualization of DSBs (DNA double strand breaks) via DNA damage foci, image analysis and the statistics of the foci for different experimental situations, chromosomal aberration formation through DSB misrepair, the kinetics of DSB repair leading to a model-derived spectrum of chromosomal aberrations, and, finally, the simulation of human tissue and the pattern of apoptotic cell damage. This compendium of theoretical and experimental data sheds light on the complex nature of radiation interacting with human DNA, cells and tissues, which can lead to mutagenesis and carcinogenesis later in human life after the space mission
Genotoxic Effects of Low- and High-LET Radiation on Human Epithelial Cells Grown in 2-D Versus 3-D Culture
Risk estimation for radiation-induced cancer relies heavily on human epidemiology data obtained from terrestrial irradiation incidents from sources such as medical and occupational exposures as well as from the atomic bomb survivors. No such data exists for exposures to the types and doses of high-LET radiation that will be encountered during space travel; therefore, risk assessment for space radiation requires the use of data derived from cell culture and animal models. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. This work compares the genotoxic effects of radiation on normal human epithelial cells grown in standard 2-D monolayer culture compared to 3-D organotypic co-culture conditions. These 3-D organotypic models mimic the morphological features, differentiation markers, and growth characteristics of fully-differentiated normal human tissue and are reproducible using defined components. Cultures were irradiated with 2 Gy low-LET gamma rays or varying doses of high-LET particle radiation and genotoxic damage was measured using a modified cytokinesis block micronucleus assay. Our results revealed a 2-fold increase in residual damage in 2 Gy gamma irradiated cells grown under organotypic culture conditions compared to monolayer culture. Irradiation with high-LET particle radiation gave similar results, while background levels of damage were comparable under both scenarios. These observations may be related to the phenomenon of "multicellular resistance" where cancer cells grown as 3-D spheroids or in vivo exhibit an increased resistance to killing by chemotherapeutic agents compared to the same cells grown in 2-D culture. A variety of factors are likely involved in mediating this process, including increased cell-cell communication, microenvironment influences, and changes in cell cycle kinetics that may promote survival of damaged cells in 3-D culture that would otherwise die or be rendered reproductively inactive in 2-D culture
Identification and proposed control of helicopter transmission noise at the source
Helicopter cabin interiors require noise treatment which is expensive and adds weight. The gears inside the main power transmission are major sources of cabin noise. Work conducted by the NASA Lewis Research Center in measuring cabin interior noise and in relating the noise spectrum to the gear vibration of the Army OH-58 helicopter is described. Flight test data indicate that the planetary gear train is a major source of cabin noise and that other low frequency sources are present that could dominate the cabin noise. Companion vibration measurements were made in a transmission test stand, revealing that the single largest contributor to the transmission vibration was the spiral bevel gear mesh. The current understanding of the nature and causes of gear and transmission noise is discussed. It is believed that the kinematical errors of the gear mesh have a strong influence on that noise. The completed NASA/Army sponsored research that applies to transmission noise reduction is summarized. The continuing research program is also reviewed
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