10 research outputs found

    Combined Microscopy, Calorimetry and X-ray Scattering Study of Fluorinated Dimesogens

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    The material FDO11DFCB3 (compound 2 in this work) remains the only example of a liquid-crystalline material to exhibit a phase transition from the heliconical twist-bend phase into a lamellar smectic A mesophase, additionally this material exhibits a previously unidentified mesophase. We have prepared and characterised several homologues of this compound, with each material subjected to an in-depth analysis by optical microscopy, calorimetry and small angle X-ray scattering studies. Despite FDO11DFCB3 being similar in chemical structure to the novel materials presented herein its liquid-crystalline behaviour is rather different, indicating an unexpected sensitivity of the twist-bend phase to molecular structure

    Depressive symptoms and smoking among Hong Kong Chinese adolescents

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    Aims: To examine associations among depressive symptoms, smoking, smoking trajectories and quitting smoking in Hong Kong. Design Prospective longitudinal design, with wave 1 at baseline (T1) and wave 2 (T2) 12 months later. Setting and participants: Form 1 (equivalent to 7th grade in the United States) students, mean age = 12.7 years, n = 1894. Measurements: Self-reported smoking status, attempts to quit and depressive symptoms. Findings At both waves, current as well as ex-smokers had higher depressive symptoms than never smokers. T1 smoking predicted T2 depressive symptoms among those with low baseline depressive symptoms. Depressive symptoms at T1 predicted smoking at T2 among non-smokers at T1. Trajectories were defined by separating participants who were never smokers at both waves ('non-smokers'), those who smoked at both waves ('persistent smokers'), those who smoked at one time but were not smoking at either wave ('past smokers), and those who had never smoked at T1 but reported smoking a year later ('new smokers'). Persistent, past and new smokers had higher depressive symptoms at both waves than non-smokers. Smokers who reported not wanting or trying to quit and those who had been unsuccessful at quitting had higher depressive symptoms at T2 than those who successfully quit. Conclusion: Our results suggest that depressive symptoms promote tobacco use in Asian adolescents by making it more likely that an adolescent will begin smoking and less likely that she or he will quit. These findings elucidate risk factors in Hong Kong for two important public health concerns for adolescents: smoking and depression. © 2005 Society for the Study of Addiction.link_to_subscribed_fulltex

    Adaptation of the Students' Motivation Towards Science Learning (SMTSL) questionnaire in the Greek language

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    The present study aimed at adapting in the Greek language the Students' Motivation Towards Science Learning (SMTSL) questionnaire developed by Tuan, Chin, and Shieh (INT J SCI EDUC 27(6): 639-654, 2005a) into a different cultural context, a different age group, that is, in university students and with a focus on physics learning. Three hundred and fifty Greek student teachers participated in the study. The original instrument consisted of 35 items allocated in six scales: self-efficacy, use of active learning strategies, science learning value, performance goals, achievement goals, and learning environment stimulation. The instrument's internal consistency was acceptable and comparable to previous studies' reports. Confirmatory factor analysis (CFA) was applied on the data in order to test an a priori hypothesis regarding the SMTSL's factorial structure based on previous studies' findings. The results of the study showed that the six-factor conceptual model of students' motivation proposed by the SMTSL applies in this different cultural setting and in this group of university students with reference to physics learning. Along with the six distinct motivational constructs confirmed, students' motivational beliefs were also explained by a general motivational construct assumed to be at their basis. Suggestions for further improvement of the Greek version of the SMTSL are also discussed
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