Improving condom use intentions and behavior by changing perceived partner norms: An evaluation of condom promotion videos for college students.

Objective: To examine the effectiveness of 2 condom promotion videotapes on self-efficacy, intentions, and behavior. Design: Two hundred twenty college students completed social-cognitive and behavioral measures and were then randomly assigned to receive one of two 30-min condom promotion videotapes (male or female student presenters) or to a wait-list control condition. Participants who watched 1 of the videotapes completed immediate posttest measures, and 85% of participants completed a 4-month follow-up. Main Outcome Measures: Self-efficacy for condom use, intentions to use condoms, use of condom during last sex, and consistent condom use over the last month. Results: Participants who received either video reported greater self-efficacy to refuse to have unprotected sex and intentions than controls at follow-up. Individuals who received either video were more likely than controls to report using a condom during last sex with a regular partner, and those who watched the female presenter were more likely to report consistent condom use. Conclusion: Participants benefited in terms of self-efficacy and intentions from receiving either video, but both men and women benefited more in terms of condom use behavior from receiving the female video. Future research is needed to determine whether opposite-sex speaker videos could be beneficial with a larger (and more sexually active) sample and whether these effects are maintained over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MBE growth and processing of diluted nitride quantum well lasers on GaAs (1 1 1)B

We have grown by Molecular Beam Epitaxy GaInNAs/GaAs (1 1 1)B quantum wells (QWs) embedded in p-i-n diode and laser diode structures. The impact of the different growth parameters (As flux, growth temperature, growth rate, ion density) on the optical and structural properties of this material is studied by Photoluminescence and Atomic Force Microscopy. Additionally, systematic studies of rapid thermal annealing cycles have been performed to optimize the laser structures. Finally, edge-emitting laser diodes have been processed using these structures. These devices showed room-temperature laser emission above 1.2 μm under pulsed current conditions.     

Physiochemical characterization of five iron tubercles from a single drinking water distribution system: Possible new insights on their formation and growth

Physiochemical data were obtained for five iron tubercles from a single drinking water distribution system (DS). Texturally, there were two groups based on internal morphology: one with a core of soft brownish material marbled with veins of a hard black material, the other has a core consisting mostly of the hard, black material. Three iron mineral phases occur, α-FeOOH, γ-FeOOH, or Fe₃O₄. All three coexist in each tubercle but in widely varying proportions. These iron pipe tubercles exhibit a greater diversity within a single DS than previously thought. Because the chemical conditions for the formation of each material is different, water quality parameters may not be the main control of tubercle formation and growth.     

Preliminary study on cost optimisation of aircraft composite structures applicable to liquid moulding technologies

This paper details the initial development of a method for determining the associated recurring labour costs for the manufacture of a aircraft component that will form the basis for a computerised methodology for determining the optimum manufacturing method for a component design. The research focuses on the flow of process steps to manufacture an aircraft component for the vacuum-assisted resin transfer moulding and resin transfer moulding manufacturing process. The methodology developed is based on applying MIT cost equations to process steps from which cost variables and constants are established to represent an estimated costing of the aircraft structure. This research will assist in providing a swifter and more accurate conceptual design/manufacturing system that includes an analysis of cost and will assist the production of trade studies that consider the manufacture of aircraft components using cost-effective technologies, such as liquid moulding.     

Preparation of periodically organized mesoporous bicomponent TiO2 and SnO2-based thin films by controlling the hydrolytic kinetics of inorganic precursors during EISA process

Highly organized cubic mesoporous TiO₂ and SnO₂ nanocrystalline thin films were reproducibly synthesized via an evaporation-induced self-assembly (EISA) process with a triblock copolymer (Pluronic F127) as the template, by precisely controlling the water content and chelating agent in the initial sol solution as well as by controlling the external relative humidity during the aging step. It has been found that the mesoscopic regularity of the fabricated mesoporous films critically depends on the hydrolytic reactions of inorganic precursors. That is, suppressing the hydrolysis reaction in the initial sol and providing the long-term stability for the sol in the coated film during the aging step are key factors in the formation of highly organized structure. The synthetic strategy was also extended to obtain various TiO₂- and SnO₂-based mixed oxide thin films with tunable composition, including WO₃/TiO₂, SiO₂/TiO₂, Nb₂O₅/SnO₂, by selectively controlling the kinetics of hydrolytic reaction for the additional inorganic precursors. The prepared composite films were crack-free, ultra-highly transparent, and thermally stable.     

Test of a micromegas detector with helium-based gas mixtures for active target time projection chambers utilizing radioactive isotope beams

A Micromegas detector was tested in a helium-carbon dioxide mixture at atmospheric pressure. A stable operation of the detector was confirmed at a gain of over 10³ for a standard alpha source of ²⁴¹Am. In order to realize a position-dependent gain, an anode strip was biased while keeping the other strips at the ground potential. The gain of the biased strip was reduced by one order of magnitude without affecting the gains of the neighboring strips. The energy spectra at 3.7 MeV, the energy deposited by Am alpha particles in the sensitive region of the Micromegas, were obtained from the total charge and the charge deposit profile along the track. The energy resolutions for helium:carbon dioxide 90:10 mixture at a gas gain of about 100 were 11% FWHM for the former and 4% FWHM for the latter. The present results highlight the Micromegas as a promising electron amplifier of the forthcoming active target time projection chambers that will be dedicated to nuclear reactions with radioactive isotope beams.     

Relationships between water attenuation coefficients derived from active and passive remote sensing: a case study from two coastal environments

Relationships between the satellite-derived diffuse attenuation coefficient of downwelling irradiance (K(d)) and airborne-based vertical attenuation of lidar volume backscattering (α) were examined in two coastal environments. At 1.1 km resolution and a wavelength of 532 nm, we found a greater connection between α and K(d) when α was computed below 2 m depth (Spearman rank correlation coefficient up to 0.96), and a larger contribution of K(d) to α with respect to the beam attenuation coefficient as estimated from lidar measurements and K(d) models. Our results suggest that concurrent passive and active optical measurements can be used to estimate total scattering coefficient and backscattering efficiency in waters without optical vertical structure.     

Genetic Variants Associated with Long-Terminal Repeats Can Diagnostically Classify Cannabis Varieties

Cannabis sativa (Cannabis) has recently been legalized in multiple countries globally for either its recreational or medicinal use. This, in turn, has led to a marked increase in the number of Cannabis varieties available for use in either market. However, little information currently exists on the genetic distinction between adopted varieties. Such fundamental knowledge is of considerable value and underpins the accelerated development of both a nascent pharmaceutical industry and the commercial recreational market. Therefore, in this study, we sought to assess genetic diversity across 10 Cannabis varieties by undertaking a reduced representation shotgun sequencing approach on 83 individual plants to identify variations which could be used to resolve the genetic structure of the assessed population. Such an approach also allowed for the identification of the genetic features putatively associated with the production of secondary metabolites in Cannabis. Initial analysis identified 3608 variants across the assessed population with phylogenetic analysis of this data subsequently enabling the confident grouping of each variety into distinct subpopulations. Within our dataset, the most diagnostically informative single nucleotide polymorphisms (SNPs) were determined to be associated with the long-terminal repeat (LTRs) class of retroelements, with 172 such SNPs used to fully resolve the genetic structure of the assessed population. These 172 SNPs could be used to design a targeted resequencing panel, which we propose could be used to rapidly screen different Cannabis plants to determine genetic relationships, as well as to provide a more robust, scientific classification of Cannabis varieties as the field moves into the pharmaceutical sphere.