Biomechanical factors in the progression of idiopathic scoliosis

Idiopathic scoliosis is present when, in upright positions of the trunk, the spine curves to the side for unknown reasons. This paper reviews evidence concerning some biomechanical factors that might underlie the progression of such curves. The review concentrates on studies conducted in our laboratories. Arguments are made, based on biomechanical analyses and experiments, that progression occurs because of defects in the postural control system of the spine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43994/1/10439_2006_Article_BF02371453.pd

Carotid Intima-Media Thickness Progression as Surrogate Marker for Cardiovascular Risk Meta-Analysis of 119 Clinical Trials Involving 100 667 Patients

Background: To quantify the association between effects of interventions on carotid intima-media thickness (cIMT) progression and their effects on cardiovascular disease (CVD) risk. Methods: We systematically collated data from randomized, controlled trials. cIMT was assessed as the mean value at the common-carotid-artery; if unavailable, the maximum value at the common-carotid-artery or other cIMT measures were used. The primary outcome was a combined CVD end point defined as myocardial infarction, stroke, revascularization procedures, or fatal CVD. We estimated intervention effects on cIMT progression and incident CVD for each trial, before relating the 2 using a Bayesian meta-regression approach. Results: We analyzed data of 119 randomized, controlled trials involving 100 667 patients (mean age 62 years, 42% female). Over an average follow-up of 3.7 years, 12 038 patients developed the combined CVD end point. Across all interventions, each 10 μm/y reduction of cIMT progression resulted in a relative risk for CVD of 0.91 (95% Credible Interval, 0.87–0.94), with an additional relative risk for CVD of 0.92 (0.87–0.97) being achieved independent of cIMT progression. Taken together, we estimated that interventions reducing cIMT progression by 10, 20, 30, or 40 μm/y would yield relative risks of 0.84 (0.75–0.93), 0.76 (0.67–0.85), 0.69 (0.59–0.79), or 0.63 (0.52–0.74), respectively. Results were similar when grouping trials by type of intervention, time of conduct, time to ultrasound follow-up, availability of individual-participant data, primary versus secondary prevention trials, type of cIMT measurement, and proportion of female patients. Conclusions: The extent of intervention effects on cIMT progression predicted the degree of CVD risk reduction. This provides a missing link supporting the usefulness of cIMT progression as a surrogate marker for CVD risk in clinical trials

Using a tacit knowledgem ethodologyt o define expertise

Consideration of the nature of expertise is inherent in expert systems development efforts. A number of assumptions regarding expertise are often made which can be problematic, particularly in management domains. This paper identifies a pre-knowledge acquisition activity that can be performed in order to address these assumptions. This activity is centered around the psychological concept of tacit knowledge. The paper outlines how the tacit knowledge methodology is being used to define and delineate expertise in the domain of entrepreneurship

A theoretical overview and extension of research on sex, gender, and entrepreneurship

With the rising number of women-owned businesses has come a considerable amount of research, and even more speculation, on differences between male and female entrepreneurs and their businesses. To date, these findings and speculations have been largely atheoretical, and little progress has been made in understanding whether such differences are pervasive, let alone why they might exist. Thus public policy-makers have had little guidance on such difficult issues as whether or not unique training and support programs should be designed for women versus men. Moreover, lenders who finance new and growing firms have little to go on but their own "gut instinct" in assessing whether women's and men's businesses are likely to run in similar ways, or whether they might be run in different but equally effective ways. The lack of integrative frameworks for understanding the nature and implications of issues related to sex, gender, and entrepreneurship has been a major obstacle. Two perspectives that help to organize and interpret past research, and highlight avenues for future research, are liberal feminism and social feminism. Liberal feminist theory suggests that women are disadvantaged relative to men due to overt discrimination and/or to systemic factors that deprive them of vital resources like business education and experience. Previous studies that have investigated whether or not women are discriminated against by lenders and consultants, and whether or not women actually do have less relevant education and experience, are consistent with a liberal feminist perspective. Those empirical studies that have been conducted provide modest evidence that overt discrimination, or any systematic lack of access to resources that women may experience, impedes their ability to succeed in business. Social feminist theory suggests that, due to differences in early and ongoing socialization, women and men do differ inherently. However, it also suggests that this does not mean women are inferior to men, as women and men may develop different but equally effective traits. Previous entrepreneurship studies that have compared men and women on socialized traits and values are consistent with a social feminist perspective. These studies have documented few consistent gender differences, and have suggested that those differences that do exist may have little impact on business performance. While this interpretation of past findings is relevant to the question of if and how female and male entrepreneurs differ, there are still large gaps in our knowledge. In particular, only one study (Kalleberg and Leicht 1991) has systematically explored whether or not potential differences related to discrimination or socialization affect business performance; the study used limited measures of business performance, and assessed only a restricted range of male I female differences. This article reports on a study that explored other potential differences related to discrimination and to socialization (which are hypothesized based on liberal and social feminism) and looked at their relationship to a more comprehensive set of business performance measures.