Dimensional changes in hardened gage steels

Thesis (Sc.D.) Massachusetts Institute of Technology. Dept. of Metallurgy, 1947.Vita.Bibliography: leaves 109-113.by Benjamin Lewis Averbach.Sc.D

On Teaching Discrete Mathematics to Freshman Computer Science Students

Discrete Mathematics is an inevitable part of any undergraduate computer science degree programme. However, today's computer science student typically finds this to be at best a necessary evil with which they struggle to engage. Twenty years ago, we started to address this issue seriously in our university, and we have instituted a number of innovations throughout the years which have had a positive effect on engagement and, thus, attainment. In this paper, we describe and motivate the innovations which we introduced, and provide a detailed analysis of how and why engagement and attainment levels varied over two decades as a direct result of these innovation

Visual masking: past accomplishments, present status, future developments

Visual masking, throughout its history, has been used as an investigative tool in exploring the temporal dynamics of visual perception, beginning with retinal processes and ending in cortical processes concerned with the conscious registration of stimuli. However, visual masking also has been a phenomenon deemed worthy of study in its own right. Most of the recent uses of visual masking have focused on the study of central processes, particularly those involved in feature, object and scene representations, in attentional control mechanisms, and in phenomenal awareness. In recent years our understanding of the phenomenon and cortical mechanisms of visual masking also has benefited from several brain imaging techniques and from a number of sophisticated and neurophysiologically plausible neural network models. Key issues and problems are discussed with the aim of guiding future empirical and theoretical research

Smoking during pregnancy and risk of abnormal glucose tolerance: a prospective cohort study

Background: Disturbances in glucose metabolism during pregnancy are associated with negative sequalae for both mother and infant. The association between smoking and abnormal glucose tolerance (AGT) remains controversial. Therefore, the aim of this study was to examine the relationship between smoking prior to and during pregnancy and risk of AGT. Methods: We utilized data from a prospective cohort of 1,006 Hispanic (predominantly Puerto Rican) prenatal care patients in Western Massachusetts. Women reported pre- and early pregnancy smoking at recruitment (mean = 15 weeks) and mid pregnancy smoking at a second interview (mean = 28 weeks). AGT was defined as \u3e 135 mg/dL on the routine 1-hour glucose tolerance test (1-hr OGTT). We used multivariable regression to assess the effect of pre, early, and mid-pregnancy smoking on risk of AGT and screening plasma glucose value from the 1-hr OGTT. Results: In age-adjusted models, women who smoked \u3e 0-9 cigarettes/day in pre-pregnancy had an increased risk of AGT (OR = 1.90; 95% CI 1.02-3.55) compared to non-smokers; this was attenuated in multivariable models. Smoking in early (OR = 0.48; 95% CI 0.21-1.10) and mid pregnancy (OR = 0.38; 95% CI 0.13-1.11) were not associated with AGT in multivariable models. Smoking during early and mid pregnancy were independently associated with lower glucose screening values, while smoking in pre-pregnancy was not. Conclusions: In this prospective cohort of Hispanic women, we did not observe an association between smoking prior to or during pregnancy and risk of AGT. Findings from this study, although based on small numbers of cases, extend prior research to the Hispanic population