Pleistocene crees in Cyrenaica (Libya)

Nord-Cyrenaika besteht aus einem Gebiet von Kalksteinhügeln, welche von tiefen und schmalen Tälern durchsetzt sind. Auf den Abhängen dieser Täler finden sich Schuttdecken zweierlei Alters, wovon die älteren festverkittet und mit terrassiertem Kies wechsellagern, während die jüngeren nicht verfestigt sind und keine zugeordneten Terrassen haben. Beide Schichten können archäologisch mit der Schichtfolge in der Haua Fteah-Höhle korreliert werden, wo Higgs (1961) eine klimatische Folge nachgewiesen hat. Es wurde gefunden, daß die beiden Schichten zwei sukzessiven kalten Zeiten des Spätpleistozäns entsprechen. Die Gerölle werden dem Spaltenfrost zugeschrieben, welch letzterer daher mittelbar für die terrassierten Kiese verantwortlich wäre. Es wird versucht, diese Resultate als abhängig von Temperatur und Niederschlag zu erklären.researc

Barriers to Physical Activity and Healthy Eating in Children as Perceived by Low-Income Parents: A Case Study

During the past three decades the prevalence of childhood obesity has steadily increased in the United States. Causes of childhood obesity are complex and include numerous individual and environmental factors. The purpose of this study was to determine parent perceptions on the social-ecological barriers (community, school, and family) to physical activity and healthy eating, perceived specific to their children. Self-reported data gathered from a 50-item questionnaire and six focus groups were conducted with parents (n=43) enrolled in the Women, Infants, and Children (WIC) Program. Participants (16 to 67 years old) were predominately female (88.4%), Hispanic (67%), low income, and living in or near Lompoc in Santa Barbara County, CA. The social-ecological model (family, school, and community) was utilized to create focus group questions and provide recommendations as part of the Lompoc Community Health Improvement Project (2006-to-the-present). Popular community barriers for physical activity were: disconnected sidewalks, lack of safe bike routes to school, lack of recreational programming at an affordable cost, and language barriers (lack of marketing physical activity programs in Spanish). Two safety barriers involved parks; fear of injury (dilapidated equipment) and fear of gangs (violence). Common school barriers were: teachers do not lead-by-example, lack of healthy food in school cafeteria, and insufficient time for children to purchase food and eat. Family barriers included: grandparents sabotaging healthy eating environments (e.g., spoilingchildren), insufficient nutrition knowledge (both children and parents), and economics (not being able to afford healthy food and a recreation/gym membership)

Transition from ballistic to drift motion in high-field transport in GaAs

With strong THz pulses, we measure ultrafast transport of electrons, holes, and an electron-hole plasma in GaAs. The transition from ballistic to drift-like transport is strongly influenced by electron-hole scattering

Learning Design through the Lens of Service: A Qualitative Study

Twenty-four senior-level capstone engineering design projects were completed at a large, public, primarily undergraduate university involving 85 students (70 male and 15 female). All projects involved the design of equipment to facilitate physical activity for people with disabilities. The effects on: i) learning design, ii) attitude towards people with disabilities, iii) motivation to complete team design projects and iv) interdisciplinary collaboration were analyzed through 24 one-hour focus groups. We explored the student experience using a constructivist approach and grounded theory. Four major themes (with associated sub-themes) emerged from our data analysis: learning design (project management, iterative design process, and user-centered design), motivation to complete design (engineering, disabilities, user), perceptions of people with disabilities (previous experience, changed attitudes and beliefs), and multidisciplinary collaboration (etiquette presentation, communication between disciplines, defining roles and expectations). Students completing these projects were shown to appreciate user-centered design, exhibit greater motivation when able to meet and develop a relationship with their client in person, discuss altruistic factors regarding their capstone experience, and were able to develop strong multidisciplinary skills

Frequency modulation spectroscopy with a THz quantum-cascade laser

We report on a terahertz spectrometer for high-resolution molecular spectroscopy based on a quantum-cascade laser. High-frequency modulation (up to 50 MHz) of the laser driving current produces a simultaneous modulation of the frequency and amplitude of the laser output. The modulation generates sidebands, which are symmetrically positioned with respect to the laser carrier frequency. The molecular transition is probed by scanning the sidebands across it. In this way, the absorption and the dispersion caused by the molecular transition are measured. The signals are modeled by taking into account the simultaneous modulation of the frequency and amplitude of the laser emission. This allows for the determination of the strength of the frequency as well as amplitude modulation of the laser and of molecular parameters such as pressure broadening

Quark spin coupling in baryons - revisited

A direct connection can be made between mixing angles in negative parity baryons and the spin coupling of constituent quarks. The mixing angles do not depend on spectral data. These angles are recalculated for gluon exchange and pion exchange between quarks. For pion exchange the results of Glozman and Riska are corrected. The experimental data on mixing are very similar to those derived from gluon exchange but substantially different from the values obtained for pion exchange.Comment: 10 pages, RevTex; a sign error is corrected, spin-orbit results are include