Seasonal Drift of \u3ci\u3eLethocerus Americanus\u3c/i\u3e (Hemiptera: Belostomatidae) in a Lake Superior Tributary

Drifting adult Lethocerus americanus were captured and retained by an inclined-screen smolt trap during two field seasons in the Bois Brule River, Wisconsin. Seasonal peaks of drift occurred in spring for 4 weeks following ice out and in autumn for 7 -8 weeks from mid-September through ice formation, and may have continued under ice cover when our gear was not operated. These findings are consistent with the known movement pattern of these insects to fly from lentic habitats to streams to overwinter but also suggest longitudinal movement via drift, perhaps to reach specific overwintering sites. Drift was significantly correlated with declining water temperatures in 1989 but not in 1990. Most drift occurred at water temperatures less than 12°C. There was no correlation between drift and river discharge. Drift rates were consistently low with a maximum by volume of 9 animals per 10,000 m3

Prototype ultrasonic instrument for quantitative testing

Ultrasonic instrument has been developed for use in quantitative nondestructive evaluation of material defects such as cracks, voids, inclusions, and unbonds. Instrument is provided with standard pulse source and transducer for each frequency range selected and includes integral aids that allow calibration to prescribed standards

Linear Connections in Non-Commutative Geometry

A construction is proposed for linear connections on non-commutative algebras. The construction relies on a generalisation of the Leibnitz rules of commutative geometry and uses the bimodule structure of $\Omega^1$. A special role is played by the extension to the framework of non-commutative geometry of the permutation of two copies of $\Omega^1$. The construction of the linear connection as well as the definition of torsion and curvature is first proposed in the setting of the derivations based differential calculus of Dubois- Violette and then a generalisation to the framework proposed by Connes as well as other non-commutative differential calculi is suggested. The covariant derivative obtained admits an extension to the tensor product of several copies of $\Omega^1$. These constructions are illustrated with the example of the algebra of $n \times n$ matrices.Comment: 15 pages, LMPM ../94 (uses phyzzx

The Role of Risk: Mentoring Experiences and Outcomes for Youth with Varying Risk Profiles

This report presents results from the nation's first large-scale study to examine how youth's levels and sources of risk may influence their mentoring relationships and the benefits they derive from participating in mentoring programs. More and more, mentoring programs are being asked to serve young people who are considered "higher risk." And while mentoring has a strong research base generally, until now relatively little has been known about programs' capacities to serve and produce benefits for these youth.Funded by the Bill & Melinda Gates Foundation, the study involved more than 1,300 youth, drawn from seven programs serving young people in Washington State. Oversight and support for the project were provided by Washington State Mentors. The study looked closely at the backgrounds of participating youth and their mentors, the mentoring relationships that formed, the program supports that were offered, and the benefits youth received -- and examined how these varied for youth with differing profiles (i.e., levels and types) of risk."The Role of Risk" describes the study's methods and findings and considers their implications for practitioners and funders. Overall, the study's results suggest that mentoring programs can benefit youth with a broad range of backgrounds and characteristics. The findings also highlight the importance of youth risk in shaping match experiences, and suggest that programs should do more to tailor training and support based on the specific risks youth face

The lab management practices of “Research Exemplars” that foster research rigor and regulatory compliance: A qualitative study of successful principal investigators

IntroductionConducting rigorous scientific inquiry within the bounds of research regulation and acceptable practice requires a principal investigator to lead and manage research processes and personnel. This study explores the practices used by investigators nominated as exemplars of research excellence and integrity to produce rigorous, reproducible research and comply with research regulations.MethodsUsing a qualitative research design, we interviewed 52 principal investigators working in the United States at top research universities and the National Institutes of Health Intramural Research Program. We solicited nominations of researchers meeting two criteria: (1) they are federally-funded researchers doing high-quality, high-impact research, and (2) have reputations for professionalism and integrity. Each investigator received an initial nomination addressing both criteria and at least one additional endorsement corroborating criteria 2. A panel of researchers and our research team reviewed the nominations to select finalists who were invited to participate. The cohort of "Research Exemplars" includes highly accomplished researchers in diverse scientific disciplines. The semi-structured interview questions asked them to describe the routine practices they employ to foster rigor and regulatory compliance. We used inductive thematic analysis to identify common practices.ResultsThe exemplars identified a core set of 8 practices and provided strategies for employing them. The practices included holding regular team meetings, encouraging shared ownership, providing supervision, ensuring adequate training, fostering positive attitudes about compliance, scrutinizing data and findings, and following standard operating procedures. Above all, the use of these practices aim to create a psychologically safe work environment in which lab members openly collaborate to scrutinize their work and share in accountability for rigorous, compliant research.ConclusionsResearchers typically receive limited systematic training in how to lead and manage their research teams. Training and education for principal investigators should include essential leadership and management practices and strategies that support doing high-quality research with integrity

The Role of Risk: Mentoring Experiences and Outcomes for Youth with Varying Risk Profiles (Executive Summary)

This summary highlights key findings and implications from the nation's first large-scale study to examine how youth's levels and sources of risk may influence their mentoring relationships and the benefits they derive from participating in mentoring programs. More and more, mentoring programs are being asked to serve young people who are considered "higher risk." And while mentoring has a strong research base generally, until now relatively little has been known about programs' capacities to serve and produce benefits for these youth.Funded by the Bill & Melinda Gates Foundation, the study involved more than 1,300 youth, drawn from seven programs serving young people in Washington State. Oversight and support for the project were provided by Washington State Mentors. The study looked closely at the backgrounds of participating youth and their mentors, the mentoring relationships that formed, the program supports that were offered, and the benefits youth received -- and examined how these varied for youth with differing profiles (i.e., levels and types) of risk."The Role of Risk" executive summary describes the study's methods and findings and considers their implications for practitioners and funders. Overall, the study's results suggest that mentoring programs can benefit youth with a broad range of backgrounds and characteristics. The findings also highlight the importance of youth risk in shaping match experiences, and suggest that programs should do more to tailor training and support based on the specific risks youth face

Number squeezed and fragmented states of strongly interacting bosons in a double well

We present a systematic study of the phenomena of number squeezing and fragmentation for a repulsive Bose-Einstein condensate (BEC) in a three dimensional double well potential over a range of interaction strengths and barrier heights, including geometries that exhibit appreciable overlap in the one-body wavefunctions localized in the left and right wells. We compute the properties of the condensate with numerically exact, full dimensional path integral ground state (PIGS) Quantum Monte Carlo simulations and compare with results obtained from using two- and eight-mode truncated basis models. The truncated basis models are found to agree with the numerically exact PIGS simulations for weak interactions, but fail to correctly predict the amount of number squeezing and fragmentation exhibited by the PIGS simulations for strong interactions. We find that both number squeezing and fragmentation of the BEC show non-monotonic behavior at large values of interaction strength a. The number squeezing shows a universal scaling with the product of number of particles and interaction strength (Na) but no such universal behavior is found for fragmentation. Detailed analysis shows that the introduction of repulsive interactions not only suppresses number fluctuations to enhance number squeezing, but can also enhance delocalization across wells and tunneling between wells, each of which may suppress number squeezing. This results in a dynamical competition whose resolution shows a complex dependence on all three physical parameters defining the system: interaction strength, number of particles, and barrier height.Comment: 33 pages, 21 figures. Submitted for publication in Physical Review