Northwestern University

About: Northwestern University is a education organization based out in Evanston, Illinois, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 75430 authors who have published 188857 publications receiving 9463252 citations. The organization is also known as: Northwestern & NU.

CMS physics technical design report, volume II: Physics performance

Abstract: CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider (LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking--through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start-up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb−1 or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, Bs production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb−1 to 30 fb−1. The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z0 boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing ET, B-mesons and τ's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model

Calcium plus Vitamin D Supplementation and the Risk of Colorectal Cancer

Abstract: Background Higher intake of calcium and vitamin D has been associated with a reduced risk of colorectal cancer in epidemiologic studies and polyp recurrence in polyp-prevention trials. However, randomized-trial evidence that calcium with vitamin D supplementation is beneficial in the primary prevention of colorectal cancer is lacking. Methods We conducted a randomized, double-blind, placebo-controlled trial involving 36,282 postmenopausal women from 40 Women’s Health Initiative centers: 18,176 women received 500 mg of elemental calcium as calcium carbonate with 200 IU of vitamin D3 twice daily (1000 mg of elemental calcium and 400 IU of vitamin D3) and 18,106 received a matching placebo for an average of 7.0 years. The incidence of pathologically confirmed colorectal cancer was the designated secondary outcome. Baseline levels of serum 25-hydroxyvitamin D were assessed in a nested case–control study. Results The incidence of invasive colorectal cancer did not differ significantly between women assigned to calcium plus vitamin D supplementation and those assigned to placebo (168 and 154 cases; hazard ratio, 1.08; 95 percent confidence interval, 0.86 to 1.34; P = 0.51), and the tumor characteristics were similar in the two groups. The frequency of colorectal-cancer screening and abdominal symptoms was similar in the two groups. There were no significant treatment interactions with baseline characteristics. Conclusions Daily supplementation of calcium with vitamin D for seven years had no effect on the incidence of colorectal cancer among postmenopausal women. The long latency associated with the development of colorectal cancer, along with the seven-year duration of the trial, may have contributed to this null finding. Ongoing follow-up will assess the longer-term effect of this intervention. (ClinicalTrials.gov number, NCT00000611.)

The Institutional Logics Perspective

Abstract: This essay discusses a new approach to institutional analysis—the institutional logics perspective (ILP). This perspective is a meta-theory useful for integrating and augmenting a variety of social science theories to better understand the effects of cultural institutions on individuals, organizations, and societies. We describe the history of the development of the ILP, define its core concepts and mechanisms, and review and discuss foundational and cutting-edge research. Prior overviews emphasize the mechanisms, variety of substantive contexts, and the cross-level effects. We take a different approach by organizing the literature review by institutional orders. This meta-analysis reveals a pattern of institutional change—the weakening of the professions and the spread of the market logic in many domains. We discuss implications of this finding and suggest future research. Keywords: institutional theory; institutional logics; institutional orders; institutional fields; institutional change

Digital Inequality Differences in Young Adults' Use of the Internet

Abstract: This article expands understanding of the digital divide to more nuanced measures of use by examining differences in young adults' online activities. Young adults are the most highly connected age group, but that does not mean that their Internet uses are homogenous. Analyzing data about the Web uses of 270 adults from across the United States, the article explores the differences in 18- to 26-year-olds' online activities and what social factors explain the variation. Findings suggest that those with higher levels of education and of a more resource-rich background use the Web for more “capitalenhancing” activities. Detailed analyses of user attributes also reveal that online skill is an important mediating factor in the types of activities people pursue online. The authors discuss the implications of these findings for a “second-level digital divide,” that is, differences among the population of young adult Internet users.