263 research outputs found

    Fast Ejection Chain Algorithms for Vehicle Routing with Time Windows

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    This paper introduces new ejection chain strategies to effectively target vehicle routing problems with time window constraints (VRPTW). Ejection chain procedures are based on the idea of compound moves that allow a variable number of solution components to be modified within any single iteration of a local search algorithm. The yardstick behind such procedures is the underlying reference structure, which is the structure that is used to coordinate the moves that are available for the local search algorithm. The main contribution of the paper is a new reference structure that is particularly suited in order to handle the asymmetric aspects in a VRPTW. The new reference structure is a generalization of the doubly rooted reference structure introduced by Glover, resulting in a new, powerful neighborhood for the VRPTW. We use tabu search for the generation of the ejection chains. On a higher algorithmic level, we study the effect of different meta heuristics to steer the tabu chain ejection process. Computational results confirm that our approach leads to very fast algorithms that can compete with the current state of the art algorithms for the VRPTW.operations research and management science;

    Psychosocial factors and attendance at a population-based mammography screening program in a cohort of Swedish women

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    BACKGROUND: A better understanding of the factors that influence mammography screening attendance is needed to improve the effectiveness of these screening programs. The objective of the study was to examine whether psychosocial factors predicted attendance at a population-based invitational mammography screening program. METHODS: Data on cohabitation, social network/support, sense of control, and stress were obtained from the Malmö Diet and Cancer Cohort Study and linked to the Malmö mammography register in Sweden. We analyzed 11,409 women (age 44 to 72) who were free of breast cancer at study entry (1992 to 1996). Mammography attendance was followed from cohort entry to December 31, 2009. Generalized Estimating Equations were used to account for repeated measures within subjects. Adjusted odds ratios (OR) and 95% confidence intervals (CI) are reported. RESULTS: Among 69,746 screening opportunities there were 5,552 (8%) cases of non-attendance. Higher odds of non-attendance were found among women who lived alone (OR = 1.47 (1.33-1.63)) or with children only (OR = 1.52 (1.29-1.81)), had one childbirth (OR = 1.12 (1.01-1.24)) or three or more childbirths (OR = 1.34 (1.21-1.48)), had low social participation (OR= 1.21 (1.10-1.31)), low sense of control (OR = 1.12 (1.02-1.23)), and experienced greater stress (OR = 1.24 (1.13-1.36)). CONCLUSIONS: Public health campaigns designed to optimize mammography screening attendance may benefit from giving more consideration of how to engage with women who are less socially involved

    The March of Judicial Cosmopolitanism and the Legacy of Enemy Combatant Case Law

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    This thesis explores the concept of judicial cosmopolitanism and its prevalence in enemy combatant case law. The author draws upon the theoretical and philosophical underpinnings of cosmopolitanism and cosmopolitan law to describe judicial cosmopolitanism as form of legal discourse through which judges show a willingness to extend constitutional protections based on a contemporary, functional understanding of sovereign jurisdiction. The purpose of this work is to address the correlation between enemy combatant jurisprudence and the aforementioned understanding of judicial cosmopolitanism. It is argued that a march of judicial cosmopolitanism developed early in enemy combatant cases, and that it came to a standstill in more recent decisions

    The March of Judicial Cosmopolitanism and the Legacy of Enemy Combatant Case Law

    Get PDF
    This thesis explores the concept of judicial cosmopolitanism and its prevalence in enemy combatant case law. The author draws upon the theoretical and philosophical underpinnings of cosmopolitanism and cosmopolitan law to describe judicial cosmopolitanism as form of legal discourse through which judges show a willingness to extend constitutional protections based on a contemporary, functional understanding of sovereign jurisdiction. The purpose of this work is to address the correlation between enemy combatant jurisprudence and the aforementioned understanding of judicial cosmopolitanism. It is argued that a march of judicial cosmopolitanism developed early in enemy combatant cases, and that it came to a standstill in more recent decisions

    Do reproductive and hormonal risk factors for breast cancer associate with attendance at mammography screening?

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    PURPOSE: To determine whether reproductive and hormonal risk factors for breast cancer associate with mammography attendance. METHODS: We linked data from the Malmö Diet and Cancer Study to the Malmö mammography register (Sweden, 1992-2009). We analyzed 11,409 women (age 44-72) who were free of breast cancer at study entry and a total of 69,746 screening invitations. Generalized Estimating Equations were used to account for repeated measures within subjects. Models were adjusted for age and other sociodemographic factors. RESULTS: In this study cohort, mammography screening attendance ranged from 87.6 to 94.5 % between calendar years, with an average attendance of 92 %. Higher attendance was found among women who had given birth to fewer than three children (ORs ranging between 1.15 and 1.37) and had used oral contraceptives (OC) within the last decade (OR = 1.22, 95 % CI 1.07-1.38) and for a longer period (OR = 1.13, 95 % CI 1.01-1.27). A lower odds of attendance was found among post-menopausal women (OR = 0.86, 95 % CI 0.77-0.96). Age <13 at menarche, age ≥30 at first childbirth, age ≥55 at menopause, age <20 at first OC use, nulliparity, breastfeeding, and hormone replacement therapy were not associated with mammography attendance. CONCLUSION: Reproductive and hormonal risk factors for breast cancer have little effect on mammography screening attendance. This may indicate a potential for under-screening of some women at higher risk

    Long term risk for hypertension, renal impairment, and cardiovascular disease after gastroenteritis from drinking water contaminated with Escherichia coli O157:H7: a prospective cohort study

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    Objectives To evaluate the risk for hypertension, renal impairment, and cardiovascular disease within eight years of gastroenteritis from drinking water contaminated with Escherichia coli O157:H7 and Campylobacter
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