7,396 research outputs found

    An introduction to numerical methods in C++

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    Early environmental field research career exploration: An analysis of impacts on precollege apprentices

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    Research apprenticeships offer opportunities for deep understanding of scientific practice, transparency about research careers, and possible transformational effects on precollege youth. We examined two consecutive field-based environmental biology apprenticeship programs designed to deliver realistic career exploration and connections to research scientists. The Shaw Institute for Field Training (SIFT) program combines introductory field-skills training with research assistance opportunities, and the subsequent Tyson Environmental Research Fellowships (TERF) program provides immersive internships on university field station–based research teams. In a longitudinal mixed-methods study grounded in social cognitive career theory, changes in youth perspectives were measured during program progression from 10th grade through college, evaluating the efficacy of encouraging career path entry. Results indicate SIFT provided self-knowledge and career perspectives more aligned with reality. During SIFT, differences were found between SIFT-only participants compared with those who progressed to TERF. Transition from educational activities to fieldwork with scientists was a pivotal moment at which data showed decreased or increased interest and confidence. Continuation to TERF provided deeper relationships with role models who gave essential early-career support. Our study indicates the two-stage apprenticeship structure influenced persistence in pursuit of an environmental research career pathway. Recommendations for other precollege environmental career–exploration programs are presented

    Assessing the Effectiveness of a Place-based Conservation Education Program by Applying Utilization-focused Evaluation

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    Lack of personal connection to the natural world by most American youth builds reason for assessing effectiveness of conservation education programs. Place-based learning is important in helping youth understand how their personal and societal well-being are linked and dependent upon their local habitats. Across Montana 2277 students in grades 3 - 10 participate in an interactive year long fishing education program with their teachers called Hooked on Fishing (HOF). The purpose of my study was to assess the effectiveness of HOF, a place-based conservation education program established in 1996, and modeled after the national Hooked on Fishing, Not on Drugs program. Using a quasi-experimental nonequivalent group study design, students received a pre-survey during the beginning of the program, a post-survey after the program, and an extended post-survey 12 to 14 weeks later. Teachers voluntarily participated in an Internet survey during May 2006, and program instructors voluntarily participated in a structured open-ended telephone interview in June 2006. A key component of my study was the decision to conduct the evaluation process using an approach which included stakeholders in the development of the instruments to measure student outcomes. This approach is called utilization-focused evaluation and was developed by Michael Q. Patton. The motive of this approach is to promote the usability of the evaluation results. The results are considered to have a better chance to be applied by the program stakeholders to not only gauge program effectiveness, but to be used to improve the program. Two research questions were: 1) does the frequency of outdoor experiences have significant affects on students\u27 knowledge, skills, attitudes, and intended stewardship behaviors; and 2) does improved knowledge of local natural resources have significant affects on students\u27 skills, attitudes and intended stewardship behavior. Nonparametric statistical analyses calculated statistical significant results for most knowledge and skill outcomes in a positive direction of change with 2 - 3 HOF outdoor experiences. Attitudinal and intended behavior outcomes did not show similar results. Internet teacher survey and instructor interviews provided qualitative depth and insight to student self-reported responses

    Preliminary evidence supports circulating microRNAs as prognostic biomarkers for type 2 diabetes.

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    Background:Circulating microRNAs are emerging as potential prognostic biomarkers for the development of type 2 diabetes. However, microRNAs are also associated with complications from impaired glucose metabolism (e.g. endothelial cell function). Prior studies have not evaluated for associations between trajectories of circulating microRNAs with trajectories of fasting blood glucose over time and the responses to behavioral interventions to reduce risk. This study performed longitudinal assessment of microRNAs and fasting blood glucose and identified relationships between microRNAs and behavioral risk reduction interventions. Methods:MicroRNAs (n = 353) were measured in subsets (n = 10, n = 8) of participants from previously completed clinical trials that studied behavioral risk reduction interventions. Fasting blood glucose trajectories were associated with changes in 45 microRNAs over 12 months. Results:Following a 3-month physical activity and dietary intervention compared with baseline, 13 microRNAs were differentially expressed. Seven microRNAs (i.e. miR-106b, miR-20b, miR-363, miR-486, miR-532, miR-92a and miR-93) were commonly identified between the two analyses. Conclusions:Further studies are needed to determine which microRNAs are prognostic biomarkers of risk for type 2 diabetes versus consequences of impaired glucose metabolism. Additional future directions of this research are to differentiate whether microRNAs are prognostic and/or diagnostic biomarkers for risk for type 2 diabetes and predictive biomarkers of responses to risk reduction interventions

    Dynamical symmetry of isobaric analog 0+ states in medium mass nuclei

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    An algebraic sp(4) shell model is introduced to achieve a deeper understanding and interpretation of the properties of pairing-governed 0+ states in medium mass atomic nuclei. The theory, which embodies the simplicity of a dynamical symmetry approach to nuclear structure, is shown to reproduce the excitation spectra and fine structure effects driven by proton-neutron interactions and isovector pairing correlations across a broad range of nuclei.Comment: 7 pages, 5 figure

    New effective interaction for pfpf-shell nuclei and its implications for the stability of the NN=ZZ=28 closed core

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    The effective interaction GXPF1 for shell-model calculations in the full pfpf shell is tested in detail from various viewpoints such as binding energies, electro-magnetic moments and transitions, and excitation spectra. The semi-magic structure is successfully described for NN or Z=28 nuclei, 53^{53}Mn, 54^{54}Fe, 55^{55}Co and 56,57,58,59^{56,57,58,59}Ni, suggesting the existence of significant core-excitations in low-lying non-yrast states as well as in high-spin yrast states. The results of N=ZN=Z odd-odd nuclei, 54^{54}Co and 58^{58}Cu, also confirm the reliability of GXPF1 interaction in the isospin dependent properties. Studies of shape coexistence suggest an advantage of Monte Carlo Shell Model over conventional calculations in cases where full-space calculations still remain too large to be practical.Comment: 29pages, 26figures, to be published in Physical Review

    Minority Stress and Leukocyte Gene Expression In Sexual Minority Men Living With Treated HIV Infection

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    Sexual minority (i.e., non-heterosexual) individuals experience poorer mental and physical health, accounted for in part by the additional burden of sexual minority stress occurring from being situated in a culture favoring heteronormativity. Informed by previous research, the purpose of this study was to identify the relationship between sexual minority stress and leukocyte gene expression related to inflammation, cancer, immune function, and cardiovascular function. Sexual minority men living with HIV who were on anti-retroviral medication, had viral load \u3c 200 copies/mL, and had biologically confirmed, recent methamphetamine use completed minority stress measures and submitted blood samples for RNA sequencing on leukocytes. Differential gene expression and pathway analyses were conducted comparing those with clinically elevated minority stress (n = 18) and those who did not meet the clinical cutoff (n = 20), covarying reactive urine toxicology results for very recent stimulant use. In total, 90 differentially expressed genes and 138 gene set pathways evidencing 2-directional perturbation were observed at false discovery rate (FDR) \u3c 0.10. Of these, 41 of the differentially expressed genes and 35 of the 2-directionally perturbed pathways were identified as functionally related to hypothesized mechanisms of inflammation, cancer, immune function, and cardiovascular function. The neuroactive-ligand receptor pathway (implicated in cancer development) was identified using signaling pathway impact analysis. Our results suggest several potential biological pathways for future work investigating the relationship between sexual minority stress and health

    The Need for Large-Scale, Longitudinal Empirical Studies in Middle Level Education Research

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    This essay describes and discusses the ongoing need for large-scale, longitudinal, empirical research studies focused on middle grades education. After a statement of the problem and concerns, the essay describes several prior middle grades efforts and research studies. Recommendations for future research efforts to inform policy decisions are provided, including roles for the Middle Level Education Research Special Interest Group (MLER SIG) of the American Educational Research Association (AERA) and other national organizations

    Nuclear symmetry energy and the r-mode instability of neutron stars

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    We analyze the role of the symmetry energy slope parameter LL on the {\it r}-mode instability of neutron stars. Our study is performed using both microscopic and phenomenological approaches of the nuclear equation of state. The microscopic ones include the Brueckner--Hartree--Fock approximation, the well known variational equation of state of Akmal, Pandharipande and Ravenhall, and a parametrization of recent Auxiliary Field Diffusion Monte Carlo calculations. For the phenomenological approaches, we use several Skyrme forces and relativisic mean field models. Our results show that the {\it r}-mode instability region is smaller for those models which give larger values of LL. The reason is that both bulk (Ο\xi) and shear (η\eta) viscosities increase with LL and, therefore, the damping of the mode is more efficient for the models with larger LL. We show also that the dependence of both viscosities on LL can be described at each density by simple power-laws of the type Ο=AΟLBΟ\xi=A_{\xi}L^{B_\xi} and η=AηLBη\eta=A_{\eta}L^{B_\eta}. Using the measured spin frequency and the estimated core temperature of the pulsar in the low-mass X-ray binary 4U 1608-52, we conclude that observational data seem to favor values of LL larger than ∌50\sim 50 MeV if this object is assumed to be outside the instability region, its radius is in the range 11.5−1211.5-12(11.5−1311.5-13) km, and its mass 1.4M⊙1.4M_\odot(2M⊙2M_\odot). Outside this range it is not possible to draw any conclusion on LL from this pulsar.Comment: 10 pages, 6 figures. Version published in Physical Review
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