459 research outputs found
Report of the panel on earth structure and dynamics, section 6
The panel identified problems related to the dynamics of the core and mantle that should be addressed by NASA programs. They include investigating the geodynamo based on observations of the Earth's magnetic field, determining the rheology of the mantle from geodetic observations of post-glacial vertical motions and changes in the gravity field, and determining the coupling between plate motions and mantle flow from geodetic observations of plate deformation. Also emphasized is the importance of support for interdisciplinary research to combine various data sets with models which couple rheology, structure and dynamics
Changing patterns in electroweak precision with new color-charged states: Oblique corrections and the boson mass
The recent measurement by the CDF Collaboration of the boson mass is in
significant tension with the Standard Model expectation, showing a discrepancy
of seven standard deviations. A larger value of affects the global
electroweak fit, particularly the best-fit values of the Peskin-Takeuchi
parameters , (and perhaps ) that measure oblique corrections from new
physics. To meet this challenge, we propose some simple models capable of
generating non-negative and , the latter of which faces the greatest
upward pressure from the CDF measurement in scenarios with . Our models
feature weak multiplets of scalars charged under , which cannot attain nonzero vacuum expectation values
but nevertheless produce e.g. given some other mechanism to split
the electrically charged and neutral scalars. We compute the oblique
corrections in these models and identify ample parameter space supporting the
CDF value of .Comment: 27 pages, 4 figure
Full superconducting gap in the candidate topological superconductor InPbTe for x = 0.2
High-pressure synthesis techniques have allowed for the growth of samples on
the indium-rich side of (Pb,In)Te, which have increased superconducting
transition temperatures compared to lead-rich compounds. In this study we
present measurements of the temperature dependence of the London penetration
depth in the compound InPbTe, which shows a
bulk of K. The results indicate fully gapped BCS-like
behavior, ruling out odd-parity, topologically nontrivial pairing;
however, odd-parity pairing is still possible. Critical field values
measured below 1 K and other superconducting parameters are also presented.Comment: 8 pages, 9 figure
The development and validation of sexual health indicators of Canadians aged 16-24 years
Objectives: We developed and validated a set of self-administered, multidimensional indicators of sexual health among Canadians aged 16–24 years. Methods: This study used a mixed-method qualitative and quantitative approach to develop and validate indicators of sexual health. We used the four-stage Dillman method to identify, focus-test, pilot-test, and validate key metrics to measure sexual health. We collected quantitative data to validate the measures through a computer-assisted self-interviewing program among a purposive sample of 1,158 people aged 16–24 years recruited from four Canadian provinces. Results: The survey contained 75 items measuring five dimensions of sexual health: (1) physical, mental, emotional, and social well-being in relation to sexuality; (2) approach to sexuality; (3) sexual relationships; (4) sexual experiences; and (5) discrimination, coercion, and violence. Principal components analysis for composite measures found seven components with eigenvalues ≥ 1. The factor structure was stable across gender, age, size of area of residence, and language in which the survey was completed. Cronbach’s alpha coefficients ranged from 0.79 to 0.90. Indicators of condom use at last vaginal sex, protection self-efficacy, sexually transmitted infection/HIV testing self-efficacy, and sexual orientation also showed good construct validity. Conclusions: The indicators constituted a conceptually grounded survey that is easy for young adults to complete and contains valid, reliable, and psychometrically robust measures. The survey instrument provides a tool for future research to collect population-level data to measure and monitor trends in the sexual health of young people in Canada
West Greenland Peregrine Falcon Survey, 1978
This brief report describes results of a survey project which has been banding West Greenland peregrines annually since 1972. Statistics on number of eyries, sex ratios, and number of young hatched per eyrie are given
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