570 research outputs found

    Smoking Behaviors among Adolescents in Foster Care: A Gender-Based Analysis

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    Background and objectives: Adolescents in foster care are at high risk for cigarette smoking. However, it is not clear how their smoking behaviors vary by gender. The present study examined lifetime and current smoking among males and females, and explored gender-specific risk factors for engagement in smoking behaviors. Method: Data from the Multi Site Evaluation of Foster Youth Programs was used to evaluate patterns of smoking among adolescents aged 12–18 years (N = 1121; 489 males, 632 females). Results: Males and females did not differ significantly in rates of lifetime and current smoking, or in the age of smoking initiation and number of cigarettes smoked on a typical day. Gender-based analyses revealed that older age and placement in group homes or residential treatment facilities were associated with heightened risk of smoking among males. In contrast, sexual minority status (i.e., nonheterosexual orientation) and increased childhood victimization were associated with heightened risk of smoking among females. A history of running away was linked to smoking in both genders. Conclusion: Gender should be considered when designing intervention programs to address cigarette smoking among foster youth, as the stressors associated with smoking may differ for males and females

    Understanding Supply Chain Complexity with Performance Measurement

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    Abstract: Despite the great number of complex systems existing in the real world, complexity is currently a poorly explored topic. In organizational settings, managers regularly apply to complex contexts classical approaches developed for simple systems, just because they do not know how to take into account companies' internal and external complexity. Nevertheless, before developing new managerial models, a deep knowledge about drivers and effects of complexity is needed. After defining the characteristics making supply chains complex systems, this paper discusses performance measurement as a methodology to analyze the effects of complexity on supply chain behavior. The results of a survey highlight that manufacturing companies usually evaluate isolated aspects of their supply chains, without considering the relationships between different performance indicators or dimensions. This work suggests System Dynamics as a valuable approach to understand the cause and effect connections among metrics and system elements affecting their values, thus clarifying the structure leading to a complex behavior. This research is the first step of a larger project aimed at providing companies with innovative tools to understand and manage supply chain complexit

    An improved unified solver for compressible and incompressible fluids involving free surfaces. II. Multi-time-step integration and applications

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    An improved numerical solver for the unified solution of compressible and incompressible fluids involving interfaces is proposed. The present method is based on the CIP-CUP (Cubic Interpolated Propagation / Combined, Unified Procedure) method, which is a pressure-based semi-implicit solver for the Euler equations of fluid flows. In Part I of this series of articles [M. Ida, Comput. Phys. Commun. 132 (2000) 44], we proposed an improved scheme for the convection terms in the equations, which allowed us discontinuous descriptions of the density interface by replacing the cubic interpolation function used in the CIP scheme with a quadratic extrapolation function only around the interface. In this paper, as Part II of this series, the multi-time-step integration technique is adapted to the CIP-CUP integration. Because the CIP-CUP treats different-nature components in the fluid equations separately, the adaptation of the technique is straightforward. This modification allows us flexible determinations of the time interval, which results in an efficient and accurate integration. Furthermore, some additional discussion on our methods is presented. Finally, the application results to composite flow problems such as compressible and incompressible Kelvin-Helmholtz instabilities and the dynamics of two acoustically coupled deformable bubbles in a viscous liquid are provided.Comment: 34 pages, 13 figures, elsart; Typo in Eq.25 corrected; Publishe

    Fiscal Centralization, Limited Government, and Public Revenues in Europe, 1650-1913

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    Old Regime polities typically suffered from fiscal fragmentation and absolutist rule. By the start of World War I, however, many such countries had centralized institutions and limited government. This article uses a new panel data set to perform a statistical analysis of political regimes and public revenues in Europe from 1650 to 1913. Panel regressions indicate that centralized and limited regimes were associated with significantly higher revenues than fragmented and absolutist ones. Structural break tests also suggest close relationships between major turning points in revenue series and political transformations

    The A and B conformations of DNA and RNA subunits. Potential energy calculations for dGpdC

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    In order to obtain a molecular picture of the A and B forms of a DNA subunit, potential energy calculations have been made for dGpdC with C(3′)-endo and C(2′)-endo [or C(3′)-exo] sugar puckerings. These are compared with results for GpC. The global minima for dGpdC and GpC are almost identical. They are like A-form duplex DNA and RNA, respectively, with bases anti, the ω′, ω angle pair near 300°, 280°, and sugar pucker C(3′)-endo. For dGpdC, a B-form helical conformer, with sugar pucker C(2′)-endo and ω′ = 257°, ω = 298°, is found only 0.4 kcal/mol above the global minimum. A second low-energy conformation (2.3 kcal/mol) has ω′ = 263°, ω = 158° and ψ near 180°. This has dihedral angles like the original Watson–Crick model of the double helix. In contrast, for GpC, the C(2′)-endo B form is 6.9 kcal/mol above the global minimum. These theoretical results are consistent with experimental studies on DNA and RNA fibers. DNA fibers exist in both A and B forms, while RNA fibers generally assume only the A form. A low-energy conformation unlike the A or B forms was found for both dGpdC and GpC when the sugars were C(3′)-endo. This conformation—ω′,ω near 20°,80°—was not observed for C(2′)-endo dGpdC. Energy surface maps in the ω′,ω plane showed that C(2′)-endo dGpdC has one low-energy valley. It is in the B-form helical region (ω′ ∼ 260°, ω ∼ 300). When the sugar pucker is C(3′)-endo, dGpdC has two low-energy regions: the A-form helical region and the region with the minimum at ω′ = 16°, ω = 85°

    Lifestyle travellers: Backpacking as a way of life

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    Scholarship on backpackers speculates some individuals may extend backpacking to a way of life. This article empirically explores this proposition using lifestyle consumption as its framing concept and conceptualises individuals who style their lives around the enduring practice of backpacking as ‘lifestyle travellers’. Ethnographic interviews with lifestyle travellers in India and Thailand offer an emic account of the practices, ideologies and social identity that characterise lifestyle travel as a distinctive subtype within backpacking. Departing from the drifter construct, which (re)constitutes this identity as socially deviant, the concept of lifestyle allows for a contemporary appraisal of these individuals’ patterns of meaningful consumption and wider insights into how ongoing mobility can lead to different ways of understanding identities and relating to place. Keywords: lifestyle consumption; backpacker; mobility; drifter; identit

    Information-theoretic active contour model for microscopy image segmentation using texture

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    High throughput technologies have increased the need for automated image analysis in a wide variety of microscopy techniques. Geometric active contour models provide a solution to automated image segmentation by incorporating statistical information in the detection of object boundaries. A statistical active contour may be defined by taking into account the optimisation of an information-theoretic measure between object and background. We focus on a product-type measure of divergence known as Cauchy-Schwartz distance which has numerical advantages over ratio-type measures. By using accurate shape derivation techniques, we define a new geometric active contour model for image segmentation combining Cauchy-Schwartz distance and Gabor energy texture filters. We demonstrate the versatility of this approach on images from the Brodatz dataset and phase-contrast microscopy images of cells

    Minimum energy conformations of DNA dimeric subunits: Potential energy calculations for dGpdC, dApdA, dCpdC, dGpdG, and dTpdT

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    Minimum energy conformations have been calculated for the deoxydinucleoside phosphates dGpdC, dApdA, dCpdC, dGpdG, and dTpdT. In these potential energy calculations the eight diheldral angles and the sugar pucker were flexible parameters. A substantial survey of conformation space was made in which all staggred combination of the dihedral angles ω′,ω, and ψ, in conjunction with C(2′)-endo pucker, were used as starting conformers for the energy minimization. The most important conformations in the C(3′)-endo-puckering domain have ψ = g+; ω′,ω = g−,g−(A-form),g+, g+, and g−,t. With C(2′)-endo-type pucker the most important conformations have ψ = g+; ω′,ω =g-,g-(B-form) and g+,t; and ψ =t; ω′,ω =g-,t(Watson-Crick from) and t,g+ (skewed). Stacked bases are a persistent feature of the low-energy conformations, the g+ conformer being an exception. Freeing the suger pucker allowed this conformation to become low energy, with C(3′)-exo pucker. It also caused other low-energy forms, such and the Waston-Crick conformation, to become more favourable. Conformation flexibility in the sugar pucker and in ψ, as well as the ω′,ω angle pair, is indicated for the dimeric subunits of DNA

    Ten myths about work addiction

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    Research into work addiction has steadily grown over the past decade. However, the literature is far from unified and there has been much debate on many different issues. Aim and methods: This paper comprises a narrative review and focuses on 10 myths about work addiction that have permeated the psychological literature and beyond. The 10 myths examined are (a) work addiction is a new behavioral addiction, (b) work addiction is similar to other behavioral addictions, (c) there are only psychosocial consequences of work addiction, (d) work addiction and workaholism are the same thing, (e) work addiction exclusively occurs as a consequence of individual personality factors, (f) work addiction only occurs in adulthood, (g) some types of work addiction are positive, (h) work addiction is a transient behavioral pattern related to situational factors, (i) work addiction is a function of the time spent engaging in work, and (j) work addiction is an example of overpathogizing everyday behavior and it will never be classed as a mental disorder in the DSM. Results: Using the empirical literature to date, it is demonstrated that there is evidence to counter each of the 10 myths. Conclusion: It appears that the field is far from unified and that there are different theoretical constructs underpinning different strands of research
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