644 research outputs found

    Young adults’ images of abstaining and drinking: Prototype dimensions, correlates and assessment methods

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    This research investigated contents of actor and abstainer prototypes with regard to young adults’ social drinking combining quantitative and qualitative approaches (adjective ratings, N = 300; open answers, N = 90). Exploratory and confirmatory factor analyses yielded two factors (sociability/hedonism, responsibility) in both prototypes, confirmed by qualitative data. Given the importance for intention and willingness to drink alcohol, interventions should focus on the factor ‘sociability/hedonism’ of the actor and the abstainer prototype to reduce heavy drinking; addressing ‘responsibility’ may be ineffective. Participants’ evaluations appeared to be less prone to mean tendencies subsequent to open answers compared with adjective scales

    Do psychological variables mediate sex differences in young adults' alcohol use?

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    This study applied an extended theory of planned behavior to test whether psychological variables mediate sex differences in alcohol consumption in social contexts. Questionnaires of 300 young adults (urban, mean age 25 years, 49% female) were collected in 2007 prior to a sociable drinking occasion; consumption data were obtained through telephone interviews thereafter. The multiple-path mediation model was analyzed using structural equation modeling. Sex differences in alcohol consumption, which were considerable, were partly mediated by the significant specific indirect effects of subjective norms through intention and of self-efficacy through both intention and willingness. Body weight was not a significant mediator. Limitations are noted and implications for future research are discussed

    Gender-related traits as predictors of alcohol use in male German and Spanish university students

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    This study examined instrumental (masculine stereotyped) and expressive (feminine stereotyped) personality traits and alcohol use among men from Germany and Spain. Participants were 161 male university students (76 German, M-age=23 years; 77 Spanish, M-age=22 years), who completed either a daytime or a nighttime drinking questionnaire, each including a Short Form of the Bem Sex Role Inventory. Poisson regression analyses with latent predictors were conducted. The trait factors and their interactions with nationality predicted daytime and nighttime alcohol use. The results add support to the assumption that alcohol use is associated with the construction of masculinity and that internalization of traditionally female attributes protects against health-risk behaviors such as alcohol consumption

    Towards reliable parameter extraction in MEMS final module testing using Bayesian inference

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    In micro-electro-mechanical systems (MEMS) testing high overall precision and reliability are essential. Due to the additional requirement of runtime efficiency, machine learning methods have been investigated in recent years. However, these methods are often associated with inherent challenges concerning uncertainty quantification and guarantees of reliability. The goal of this paper is therefore to present a new machine learning approach in MEMS testing based on Bayesian inference to determine whether the estimation is trustworthy. The overall predictive performance as well as the uncertainty quantification are evaluated with four methods: Bayesian neural network, mixture density network, probabilistic Bayesian neural network and BayesFlow. They are investigated under the variation in training set size, different additive noise levels, and an out-of-distribution condition, namely the variation in the damping factor of the MEMS device. Furthermore, epistemic and aleatoric uncertainties are evaluated and discussed to encourage thorough inspection of models before deployment striving for reliable and efficient parameter estimation during final module testing of MEMS devices. BayesFlow consistently outperformed the other methods in terms of the predictive performance. As the probabilistic Bayesian neural network enables the distinction between epistemic and aleatoric uncertainty, their share of the total uncertainty has been intensively studied

    Isolation of the phe-operon from G. stearothermophilus comprising the phenol degradative meta-pathway genes and a novel transcriptional regulator

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    <p>Abstract</p> <p>Background</p> <p><it>Geobacillus stearothermophilus </it>is able to utilize phenol as a sole carbon source. A DNA fragment encoding a phenol hydroxylase catalyzing the first step in the <it>meta</it>-pathway has been isolated previously. Based on these findings a PCR-based DNA walk was performed initially to isolate a catechol 2,3-dioxygenase for biosensoric applications but was continued to elucidate the organisation of the genes encoding the proteins for the metabolization of phenol.</p> <p>Results</p> <p>A 20.2 kb DNA fragment was isolated as a result of the DNA walk. Fifteen open reading frames residing on a low-copy megaplasmid were identified. Eleven genes are co-transcribed in one polycistronic mRNA as shown by reverse transcription-PCR. Ten genes encode proteins, that are directly linked with the <it>meta</it>-cleavage pathway. The deduced amino acid sequences display similarities to a two-component phenol hydroxylase, a catechol 2,3-dioxygenase, a 4-oxalocrotonate tautomerase, a 2-oxopent-4-dienoate hydratase, a 4-oxalocrotonate decarboxylase, a 4-hydroxy-2-oxovalerate aldolase, an acetaldehyde dehydrogenase, a plant-type ferredoxin involved in the reactivation of extradiol dioxygenases and a novel regulatory protein. The only enzymes missing for the complete mineralization of phenol are a 2-hydroxymuconic acid-6-semialdehyde hydrolase and/or 2-hydroxymuconic acid-6-semialdehyde dehydrogenase.</p> <p>Conclusion</p> <p>Research on the bacterial degradation of aromatic compounds on a sub-cellular level has been more intensively studied in gram-negative organisms than in gram-positive bacteria. Especially regulatory mechanisms in gram-positive (thermophilic) prokaryotes remain mostly unknown. We isolated the first complete sequence of an operon from a thermophilic bacterium encoding the <it>meta</it>-pathway genes and analyzed the genetic organization. Moreover, the first transcriptional regulator of the phenol metabolism in gram-positive bacteria was identified. This is a first step to elucidate regulatory mechanisms that are likely to be distinct from modes described for gram-negative bacteria.</p
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