379 research outputs found

    How does person-organization fit affect behavioral and attitudinal outcomes? Working paper series--09-01

    Get PDF
    While a significant amount of research has investigated the relationship between person-organization fit (P-O fit) and multiple individual outcomes, potential mediators of these relationships have been studied less frequently. This study explores psychological empowerment as mediating the relationship between P-O fit and two individual-level outcomes: in-role performance and intention to turnover. Structural equation modeling results suggest that psychological empowerment partially mediates the P-O fit's relationships with intention to turnover and in-role performance

    The roles of charge exchange and dissociation in spreading Saturn's neutral clouds

    Full text link
    Neutrals sourced directly from Enceladus's plumes are initially confined to a dense neutral torus in Enceladus's orbit around Saturn. This neutral torus is redistributed by charge exchange, impact/photodissociation, and neutral-neutral collisions to produce Saturn's neutral clouds. Here we consider the former processes in greater detail than in previous studies. In the case of dissociation, models have assumed that OH is produced with a single speed of 1 km/s, whereas laboratory measurements suggest a range of speeds between 1 and 1.6 km/s. We show that the high-speed case increases dissociation's range of influence from 9 to 15 Rs. For charge exchange, we present a new modeling approach, where the ions are followed within a neutral background, whereas neutral cloud models are conventionally constructed from the neutrals' point of view. This approach allows us to comment on the significance of the ions' gyrophase at the moment charge exchange occurs. Accounting for gyrophase: (1) has no consequence on the H2O cloud; (2) doubles the local density of OH at the orbit of Enceladus; and (3) decreases the oxygen densities at Enceladus's orbit by less than 10%. Finally, we consider velocity-dependent, as well as species-dependent cross sections and find that the oxygen cloud produced from charge exchange is spread out more than H2O, whereas the OH cloud is the most confined.Comment: Accepted to the Journal of Geophysical Research, 49 pages, 10 figure

    Neighborhood-Level Social Determinants of Health Burden Among Adolescent and Young Adult Cancer Patients and Impact on Overall Survival

    Get PDF
    BACKGROUND: Neighborhood socioeconomic deprivation has been linked to adverse health outcomes, yet it is unclear whether neighborhood-level social determinants of health (SDOH) measures affect overall survival in adolescent and young adult patients with cancer. METHODS: This study used a diverse cohort of adolescent and young adult patients with cancer (N = 10 261) seen at MD Anderson Cancer Center. Zip codes were linked to Area Deprivation Index (ADI) values, a validated neighborhood-level SDOH measure, with higher ADI values representing worse SDOH. RESULTS: ADI was statistically significantly worse (P \u3c .050) for Black (61.7) and Hispanic (65.3) patients than for White patients (51.2). Analysis of ADI by cancer type showed statistically significant differences, mainly driven by worse ADI in patients with cervical cancer (62.3) than with other cancers. In multivariable models including sex, age at diagnosis, cancer diagnosis, and race and ethnicity, risk of shorter survival for people residing in neighborhoods with the least favorable ADI quartile was greater than for individuals in the most favorable ADI quartile (hazard ratio = 1.09, 95% confidence interval = 1.00 to 1.19, P = .043). CONCLUSION: Adolescent and young adult patients with cancer and the worst ADI values experienced a nearly 10% increase in risk of dying than patients with more favorable ADI values. This effect was strongest among White adolescent and young adult survivors. Although the magnitude of the effect of ADI on survival was moderate, the presence of a relationship between neighborhood-level SDOH and survival among patients who received care at a tertiary cancer center suggests that ADI is a meaningful predictor of survival. These findings provide intriguing evidence for potential interventions aimed at supporting adolescent and young adult patients with cancer from disadvantaged neighborhoods

    Views of young, rural African Americans of the role of community social institutions in HIV prevention.

    Get PDF
    BACKGROUND: We explored rural African American youths' perceptions about the role of community social institutions in addressing HIV. METHODS: We conducted four focus groups with African Americans aged 16 to 24 years in two rural counties in North Carolina. Groups were stratified by gender and risk status. We used a grounded theory approach to content analysis. RESULTS: Participants identified four social institutions as primary providers of HIV-related health promotion efforts: faith organizations, schools, politicians, and health agencies. They reported perceiving a lack of involvement in HIV prevention by faith-based organizations, constraints of abstinence-based sex education policies, politicians' lack of interest in addressing broader HIV determinants, and inadequacies in health agency services, and viewed all of these as being counter-productive to HIV prevention efforts. CONCLUSIONS: Youth have important insights about local social institutions that should be considered when designing HIV prevention interventions that partner with local organizations

    WACCM-D Whole Atmosphere Community Climate Model with D-region ion chemistry

    Get PDF
    Energetic particle precipitation (EPP) and ion chemistry affect the neutral composition of the polar middle atmosphere. For example, production of odd nitrogen and odd hydrogen during strong events can decrease ozone by tens of percent. However, the standard ion chemistry parameterization used in atmospheric models neglects the effects on some important species, such as nitric acid. We present WACCM-D, a variant of the Whole Atmosphere Community Climate Model, which includes a set of lower ionosphere (D-region) chemistry: 307 reactions of 20 positive ions and 21 negative ions. We consider realistic ionization scenarios and compare the WACCM-D results to those from the Sodankylä Ion and Neutral Chemistry (SIC), a state-of-the-art 1-D model of the D-region chemistry. We show that WACCM-D produces well the main characteristics of the D-region ionosphere, as well as the overall proportion of important ion groups, in agreement with SIC. Comparison of ion concentrations shows that the WACCM-D bias is typically within ±10% or less below 70 km. At 70–90 km, when strong altitude gradients in ionization rates and/or ion concentrations exist, the bias can be larger for some groups but is still within tens of percent. Based on the good agreement overall and the fact that part of the differences are caused by different model setups, WACCM-D provides a state-of-the-art global representation of D-region ion chemistry and is therefore expected to improve EPP modeling considerably. These improvements are demonstrated in a companion paper by Andersson et al

    Achievement of target gain larger than unity in an inertial fusion experiment.

    Get PDF
    On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result

    Studies on the Restriction of Murine Leukemia Viruses by Mouse APOBEC3

    Get PDF
    APOBEC3 proteins function to restrict the replication of retroviruses. One mechanism of this restriction is deamination of cytidines to uridines in (−) strand DNA, resulting in hypermutation of guanosines to adenosines in viral (+) strands. However, Moloney murine leukemia virus (MoMLV) is partially resistant to restriction by mouse APOBEC3 (mA3) and virtually completely resistant to mA3-induced hypermutation. In contrast, the sequences of MLV genomes that are in mouse DNA suggest that they were susceptible to mA3-induced deamination when they infected the mouse germline. We tested the possibility that sensitivity to mA3 restriction and to deamination resides in the viral gag gene. We generated a chimeric MLV in which the gag gene was from an endogenous MLV in the mouse germline, while the remainder of the viral genome was from MoMLV. This chimera was fully infectious but its response to mA3 was indistinguishable from that of MoMLV. Thus, the Gag protein does not seem to control the sensitivity of MLVs to mA3. We also found that MLVs inactivated by mA3 do not synthesize viral DNA upon infection; thus mA3 restriction of MLV occurs before or at reverse transcription. In contrast, HIV-1 restricted by mA3 and MLVs restricted by human APOBEC3G do synthesize DNA; these DNAs exhibit APOBEC3-induced hypermutation
    • …
    corecore