2,351 research outputs found
Inhomogeneous superconductivity induced in a weak ferromagnet
Under certain conditions, the order parameter induced by a superconductor (S)
in a ferromagnet (F) can be inhomogeneous and oscillating, which results e.g.
in the so-called pi-coupling in S/F/S junctions. In principle, the
inhomogeneous state can be induced at T_c as function of the F-layer thickness
d_F in S/F bilayers and multilayers, which should result in a dip-like
characteristic of T_c(d_F). We show the results of measurements on the S/F
system Nb/Cu_{1-x}Ni_x, for Ni-concentrations in the range x = 0.5-0.7, where
such effects might be expected. We find that the critical thickness for the
occurrence of superconductivity is still relatively high, even for these weak
ferromagnets. The resulting dip then is intrinsically shallow and difficult to
observe, which explains the lack of a clear signature in the T_c(d_F) data.Comment: 4 pages, 4 figures. To be publishedin Physica C (proceedings of the
Second Euroconference on Vortex Matter in Superconductors, Crete, 2001
Teaching & Learning The Spanish Aspect Using Blogs and Wikis: An Exploratory Study
This study investigated the influence of asynchronous computer text based technologies on the students’ performance when learning the preterite and the imperfect aspects in Spanish. Two research questions guided the study: Research Question 1) Is there a difference in students’ achievement levels in Spanish preterite and imperfect between those using wiki technologies and those using blog technologies after controlling for pre-intervention achievement levels? and Research Question 2) Are there differences in satisfaction levels for students learning Spanish preterite and imperfect via blog technologies as compared to those learning via wiki technologies? Results indicate that there were not significant differences between students who use blog or wiki technologies on performance levels when controlling for pre-existing knowledge. Results also indicated that there were not significant differences in satisfaction levels between those students using a wiki and those using a blog. These results suggest that wikis and blogs are good potential tools that may facilitate the teaching and learning of problematic grammar structures in a narrative context
Experiences of a commercial weight-loss programme after primary care referral: a qualitative study.
BACKGROUND: Referral to a commercial weight-loss programme is a cost-effective intervention that is already used within the NHS. Qualitative research suggests this community-based, non-medical intervention accords with participants' view of weight management as a lifestyle issue. AIM: To examine the ways in which participants' attitudes and beliefs about accessing a commercial weight management programme via their doctor relate to their weight-loss experience, and to understand how these contextual factors influence motivation and adherence to the intervention. DESIGN AND SETTING: A qualitative study embedded in a randomised controlled trial evaluating primary care referral to a commercial weight-loss programme in adults who are overweight or obese in England. The study took place from June-September 2013. METHOD: Twenty-nine participants (body mass index [BMI] ≥28 kg/m(2); age ≥18 years), who took part in the WRAP (Weight Loss Referrals for Adults in Primary Care) trial, were recruited at their 3-month assessment appointment to participate in a semi-structured interview about their experience of the intervention and weight management more generally. Interviews were audiorecorded, transcribed verbatim, and analysed inductively using a narrative approach. RESULTS: Although participants view the lifestyle-based, non-medical commercial programme as an appropriate intervention for weight management, the referral from the GP and subsequent clinical assessments frame their experience of the intervention as medically pertinent with clear health benefits. CONCLUSION: Referral by the GP and follow-up assessment appointments were integral to participant experiences of the intervention, and could be adapted for use in general practice potentially to augment treatment effects
Microbiology and atmospheric processes: Biological, physical and chemical characterization of aerosol particles
The interest in bioaerosols has traditionally been linked to health hazards for humans, animals and plants. However, several components of bioaerosols exhibit physical properties of great significance for cloud processes, such as ice nucleation and cloud condensation. To gain a better understanding of their influence on climate, it is therefore important to determine the composition, concentration, seasonal fluctuation, regional diversity and evolution of bioaerosols. In this paper, we will review briefly the existing techniques for detection, quantification, physical and chemical analysis of biological particles, attempting to bridge physical, chemical and biological methods for analysis of biological particles and integrate them with aerosol sampling techniques. We will also explore some emerging spectroscopy techniques for bulk and single-particle analysis that have potential for in-situ physical and chemical analysis. Lastly, we will outline open questions and further desired capabilities (e. g., in-situ, sensitive, both broad and selective, on-line, time-resolved, rapid, versatile, cost-effective techniques) required prior to comprehensive understanding of chemical and physical characterization of bioaerosols
Production of Secondary Organic Aerosol During Aging of Biomass Burning Smoke From Fresh Fuels and Its Relationship to VOC Precursors
After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog-chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high-resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low-volatility POA as a reference standard (akin to a naturally occurring internal standard). These smoke aging experiments revealed variable organic aerosol (OA) enhancements, even for smoke from similar fuels and aging mechanisms. This variable OA enhancement correlated well with measured differences in the amounts of emitted volatile organic compounds (VOCs) that could subsequently be oxidized to form SOA. For some aging experiments, we were able to predict the SOA production to within a factor of 2 using a fuel-specific VOC emission inventory that was scaled by burn-specific toluene measurements. For fires of coniferous fuels that were dominated by needle burning, volatile biogenic compounds were the dominant precursor class. For wiregrass fires, furans were the dominant SOA precursors. We used a POA tracer ion to calculate the amount of mass lost due to gas-phase oxidation and subsequent volatilization of semivolatile POA. Less than 5% of the POA mass was lost via multiphase oxidation-driven evaporation during up to 2 hr of equivalent atmospheric oxidation
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Sex differences in the reward value of familiar mates in prairie voles
The rewarding properties of social interactions facilitate relationship formation and maintenance. Prairie voles are one of the few laboratory species that form selective relationships, manifested as “partner preferences” for familiar partners versus strangers. While both sexes exhibit strong partner preferences, this similarity in outward behavior likely results from sex-specific neurobiological mechanisms. We recently demonstrated that in operant trials, females worked hardest for access to familiar conspecifics of either sex, while males worked equally hard for access to any female, indicating a sex difference in social motivation. As tests were performed with one social target at a time, males might have experienced a ceiling effect, and familiar females might be more relatively rewarding in a choice scenario. Here we performed an operant social choice task in which voles lever-pressed to gain temporary access to either the chamber containing their mate or one containing a novel opposite-sex vole. Females worked hardest to access their mate, while males pressed at similar rates for either female. Individual male behavior was heterogeneous, congruent with multiple mating strategies in the wild. Voles exhibited preferences for favorable over unfavorable environments in a non-social operant task, indicating that lack of social preference does not reflect lack of discrimination. Natural variation in oxytocin receptor genotype at the intronic single nucleotide polymorphism NT213739 was associated with oxytocin receptor density, and predicted individual variation in stranger-directed aggressive behavior. These findings suggest that convergent preference behavior in male and female voles results from sex-divergent pathways, particularly in the realm of social motivation
Behavior change interventions: the potential of ontologies for advancing science and practice
A central goal of behavioral medicine is the creation of evidence-based interventions for promoting behavior change. Scientific knowledge about behavior change could be more effectively accumulated using "ontologies." In information science, an ontology is a systematic method for articulating a "controlled vocabulary" of agreed-upon terms and their inter-relationships. It involves three core elements: (1) a controlled vocabulary specifying and defining existing classes; (2) specification of the inter-relationships between classes; and (3) codification in a computer-readable format to enable knowledge generation, organization, reuse, integration, and analysis. This paper introduces ontologies, provides a review of current efforts to create ontologies related to behavior change interventions and suggests future work. This paper was written by behavioral medicine and information science experts and was developed in partnership between the Society of Behavioral Medicine's Technology Special Interest Group (SIG) and the Theories and Techniques of Behavior Change Interventions SIG. In recent years significant progress has been made in the foundational work needed to develop ontologies of behavior change. Ontologies of behavior change could facilitate a transformation of behavioral science from a field in which data from different experiments are siloed into one in which data across experiments could be compared and/or integrated. This could facilitate new approaches to hypothesis generation and knowledge discovery in behavioral science
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