1,968 research outputs found

    The Highway Career Plan in Michigan

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    Cannabis use and other predictors of the onset of daily cigarette use in young men: what matters most? Results from a longitudinal study.

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    BACKGROUND: According to the gateway hypothesis, tobacco use is a gateway of cannabis use. However, there is increasing evidence that cannabis use also predicts the progression of tobacco use (reverse gateway hypothesis). Unfortunately, the importance of cannabis use compared to other predictors of tobacco use is less clear. The aim of this study was to examine which variables, in addition to cannabis use, best predict the onset of daily cigarette smoking in young men. METHODS: A total of 5,590 young Swiss men (mean age = 19.4 years, SD = 1.2) provided data on their substance use, socio-demographic background, religion, health, social context, and personality at baseline and after 18 months. We modelled the predictors of progression to daily cigarette smoking using logistic regression analyses (n = 4,230). RESULTS: In the multivariate overall model, use of cannabis remained among the strongest predictors for the onset of daily cigarette use. Daily cigarette use was also predicted by a lifetime use of at least 50 cigarettes, occasional cigarette use, educational level, religious affiliation, parental situation, peers with psychiatric problems, and sociability. CONCLUSIONS: Our results highlight the relevance of cannabis use compared to other potential predictors of the progression of tobacco use and thereby support the reverse gateway hypothesis

    Predictors of onset of cannabis and other drug use in male young adults: results from a longitudinal study.

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    BACKGROUND: The use of cannabis and other illegal drugs is particularly prevalent in male young adults and is associated with severe health problems. This longitudinal study explored variables associated with the onset of cannabis use and the onset of illegal drug use other than cannabis separately in male young adults, including demographics, religion and religiosity, health, social context, substance use, and personality. Furthermore, we explored how far the gateway hypothesis and the common liability to addiction model are in line with the resulting prediction models. METHODS: The data were gathered within the Cohort Study on Substance Use Risk Factors (C-SURF). Young men aged around 20 years provided demographic, social, health, substance use, and personality-related data at baseline. Onset of cannabis and other drug use were assessed at 15-months follow-up. Samples of 2,774 and 4,254 individuals who indicated at baseline that they have not used cannabis and other drugs, respectively, in their life and who provided follow-up data were used for the prediction models. Hierarchical logistic stepwise regressions were conducted, in order to identify predictors of the late onset of cannabis and other drug use separately. RESULTS: Not providing for oneself, having siblings, depressiveness, parental divorce, lower parental knowledge of peers and the whereabouts, peer pressure, very low nicotine dependence, and sensation seeking were positively associated with the onset of cannabis use. Practising religion was negatively associated with the onset of cannabis use. Onset of drug use other than cannabis showed a positive association with depressiveness, antisocial personality disorder, lower parental knowledge of peers and the whereabouts, psychiatric problems of peers, problematic cannabis use, and sensation seeking. CONCLUSIONS: Consideration of the predictor variables identified within this study may help to identify young male adults for whom preventive measures for cannabis or other drug use are most appropriate. The results provide evidence for both the gateway hypothesis and the common liability to addiction model and point to further variables like depressiveness or practising of religion that might influence the onset of drug use

    Attitude and Phase Synchronization of Formation Flying Spacecraft: Lagrangian Approach

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    This article presents a unified synchronization framework with application to precision formation flying spacecraft. Central to the proposed innovation, in applying synchroniza- tion to both translational and rotational dynamics in the Lagrangian form, is the use of the distributed stability and performance analysis tool, called contraction analysis that yields exact nonlinear stability proofs. The proposed decentralized tracking control law synchronizes the attitude of an arbitrary number of spacecraft into a common time-varying trajectory with global exponential convergence. Moreover, a decentralized translational tracking control law based on phase synchronization is presented, thus enabling coupled translational and rotational maneuvers. While the translational dynamics can be adequately controlled by linear control laws, the proposed method permits highly nonlinear systems with nonlinearly coupled inertia matrices such as the attitude dynamics of space-craft whose large and rapid slew maneuvers justify the nonlinear control approach. The proposed method integrates both the trajectory tracking and synchronization problems in a single control framework

    Problematic smartphone use in young Swiss men: Its association with problematic substance use and risk factors derived from the pathway model.

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    This study aimed to examine associations between risk factors suggested in the pathway model proposed by Billieux et al., demographic and substance use variables, and problematic smartphone use (PSU). The analytical sample consisted of 5,096 Swiss men (mean age = 25.5 years, SD = 1.26). Multiple linear regression analyses were conducted with PSU as dependent and the following as independent variables: (a) Billieux's pathway model variables (depression, social anxiety, ADHD, aggression-hostility, and sensation seeking); (b) substance use variables [alcohol: at-risk risky single-occasion drinking (RSOD); at-risk volume drinking; tobacco use: daily smoking; illicit drug use: more than weekly cannabis use; having used at least one other illicit drug besides cannabis over the preceding 12 months]; and (c) sociodemographic variables (age, language region, and education). All pathway-model variables except sensation seeking were significant predictors of PSU, especially symptoms of social anxiety (β = 0.196) and ADHD (β = 0.184). At-risk RSOD was positively (β = 0.071) associated with PSU, whereas both frequent cannabis use (β = -0.060) and daily cigarette smoking (β = -0.035) were negatively associated with PSU. Higher-achieved educational levels and being from the German-speaking part of Switzerland predicted PSU. The findings of this study can be used to develop tailored interventional programs that address the co-occurrence of certain risky behaviors (e.g., at-risk RSOD and PSU) and target individuals who might be particularly prone to PSU. Such interventions would need to ensure that addressing one problem (e.g., decreasing PSU) does not lead to some other compensatory behavior (e.g., frequent cigarette smoking)

    Mirror formation control in the vicinity of an asteroid

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    Two strategies are presented for the positioning and control of a spacecraft formation designed to focus sunlight onto a point on the surface of asteroid, thereby sublimating the material and ejecting debris creating thrust. In the first approach, the formation is located at artficial equilibrium points around the asteroid and controlled using the force from the solar radiation pressure. The second approach determines the optimal periodic formation orbits, subject to the gravitational perturbations from the asteroid, the solar radiation pressure and the control acceleration derived from a control law

    Tiling of the five-fold surface of Al(70)Pd(21)Mn(9)

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    The nature of the five-fold surface of Al(70)Pd(21)Mn(9) has been investigated using scanning tunneling microscopy. From high resolution images of the terraces, a tiling of the surface has been constructed using pentagonal prototiles. This tiling matches the bulk model of Boudard et. al. (J. Phys.: Cond. Matter 4, 10149, (1992)), which allows us to elucidate the atomic nature of the surface. Furthermore, it is consistent with a Penrose tiling T^*((P1)r) obtained from the geometric model based on the three-dimensional tiling T^*(2F). The results provide direct confirmation that the five-fold surface of i-Al-Pd-Mn is a termination of the bulk structure.Comment: 4 pages, 4 figure

    Ischemic postconditioning protects remodeled myocardium via the PI3K-PKB/Akt reperfusion injury salvage kinase pathway

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    OBJECTIVE: We tested whether ischemic postconditioning (IPostC) is protective in remodeled myocardium. METHODS: Post-myocardial infarct (MI)-remodeled hearts after permanent coronary artery ligation and one kidney one clip (1K1C) hypertensive hearts of male Wistar rats were exposed to 40 min of ischemia followed by 90 min of reperfusion. IPostC was induced by six cycles of 10 s reperfusion interspersed by 10 s of no-flow ischemia. Activation of reperfusion injury salvage kinases was measured using Western blotting and in vitro kinase activity assays. RESULTS: IPostC prevented myocardial damage in both MI-remodeled and 1K1C hearts, as measured by decreased infarct size and lactate dehydrogenase release, and improved function. The reduction in infarct size and the recovery of left ventricular contractility achieved by IPostC was less in 1K1C hearts, but was unchanged in MI-remodeled hearts when compared to healthy hearts. In contrast, the recovery of inotropy was unaffected in 1K1C hearts, but was less in MI-remodeled hearts. Inhibition of the phosphatidylinositol 3-kinase (PI3K) pathway with LY294002 abolished the protective effects of IPostC on both disease models and healthy hearts. Western blot analysis in conjunction with in vitro kinase activity assays identified protein kinase B (PKB)/Akt but not p42/p44 extracellular-signal regulated kinase 1/2 (ERK1/2) as the predominant kinase in IPostC-mediated cardioprotection in remodeled hearts. IPostC increased phosphorylation of the PKB/Akt downstream targets eNOS, GSK3beta, and p70S6K in remodeled hearts. CONCLUSION: Our results offer evidence that IPostC mediates cardioprotection in the remodeled rat myocardium primarily via activation of the PI3K-PKB/Akt reperfusion injury salvage kinase pathwa

    Strategic responses to global challenges: The case of European banking, 1973–2000

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    In applying a strategy, structure, ownership and performance (SSOP) framework to three major clearing banks (ABN AMRO, UBS, Barclays), this article debates whether the conclusions generated by Whittington and Mayer about European manufacturing industry can be applied to the financial services sector. While European integration plays a key role in determining strategy, it is clear that global factors were far more important in determining management actions, leading to significant differences in structural adaptation. The article also debates whether this has led to improved performance, given the problems experienced with both geographical dispersion and diversification, bringing into question the quality of decision-making over the long term

    Misdevelopments, Pathologies, and Normative Revolutions: Normative Reconstruction as Method of Critical Theory

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    In this article I argue that the method of normative reconstruction underlying Freedom's Right undermines Critical Theory's aspiration to be a force that is unreservedly critical and progressive. I start out by giving a brief account of the four premises of the method of normative reconstruction and unpack their implications for how Honneth conceptualizes social pathologies and misdevelopments, specifically that these notions are no longer linked to radical critique and normative revolution. In the second part, I demonstrate that abandoning forms of radical critique and normative revolution is internally linked to adopting this method, before arguing that Freedom's Right contains no resources to account for why abandoning them does not amount to a deficiency. In the final part, I point out two problematic implications of turning away from radical critique and normative revolution for the very project Honneth pursues in Freedom's Right. I show that Honneth's own view about the limited scope of application of the method of normative reconstruction and his account of the dangers associated with social misdevelopments give us (additional) reasons to consider this method to be incomplete. Finally, I contend that the explanatory power of Freedom's Right is dubious because methodological premises that form part of normative reconstruction lead Honneth to ignore relevant alternative explanations of processes of deviation and disassociation from norms of social freedom, which he characterizes as social misdevelopments
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