A modified Weibull treatment for the analysis of strength-test data from non-identical brittle specimens

Powder compacts (e.g., pharmaceutical tablets) manufactured on commerically available machines are not strictly identical but show inevitable variability in their weights, thicknesses and compaction pressures. Consequently, the variability in fracture-stress data obtained from such brittle specimens is greater than that due to the inherent strength variability of the material itself. A modified Weibull analysis has been developed so that a more accurate estimate of the inherent variability of the mechanical strength of the material can be derived from test data obtained from commercially produced compacts; its application is illustrated.Nomenclature D diameter - f() relative frequency of occurrence of specimens with density and volume - F minimization function - i ascending rank number of a fracture stress - m Weibull modulus - N _tot number of specimens in a batch - N() number of specimens with densities in the range to + d and volumes in the range to + d - P _f failure probability - p _u upper punch compaction pressure - t thickness - volume - w weight - W _f fracture load - density - _f fracture stress - ¯ _f mean fracture stress of a batch - ¯ _f() mean fracture stress of specimens with density and volume - ₀ scale parameter or normalizing factor - _u location parameter or threshold stress     

How have patients reacted to the implications of the DCCT?

OBJECTIVES: To assess the reactions of people with insulin-treated diabetes (ITD) to the results of the Diabetes Control and Complications Trial (DCCT). RESEARCH DESIGN AND METHODS: A leaflet documenting the purpose and results of the DCCT was circulated to all 771 patients ages 15-60 years with ITD attending our clinic. Patients were invited to complete and return a questionnaire on their responses. RESULTS: Of 550 respondents, 330 felt encouraged to improve glycemic control. Female respondents (P = 0.003) and younger age-groups (15-25 years, P = 0.001) were most likely to want to improve control. Patients with long duration of diabetes (> 20 years, P = 0.00001), hypoglycemia unawareness (P = 0.0001), or previous severe hypoglycemia (P = 0.001) were less likely to want to improve their control. Fear of hypoglycemia concerned all age-groups, whereas female respondents were most likely to be worried about the potential for weight gain (P = 0.00006). CONCLUSIONS: Knowledge of the results of the DCCT encourages significant numbers of patients to want to improve glycemic control. Fear of hypoglycemia and, in women, weight gain may prove significant impediments to the clinical implementation of the results of the DCCT.     

Opposite effects of bezafibrate and gemfibrozil in both normal and hypertriglyceridemic rats

The diagnostic value of zinc protoporphyrin (ZPP) as an indicator of iron-deficient anemia (IDA) in hospitalized patients is assessed in this study. ZPP was measured using an AVIV hematofluorometer with a coefficient of variation (CV) less than 5% and a recovery of greater than 97%. A reference range of 53-70 mu mol/mol heme was determined for ZPP in non-anemic patients in a hospital population. Hospitalized patients (221) with low hemoglobin (< 120 g/l) were evaluated for their iron status. ZPP and other anemia tests were performed. Macrocytic patients with mean corpuscular volume (MCV) greater than 98 fl) were excluded from the study. Seventy-four microcytic patients (MCV < 80 fl) were determined as having IDA according to a diagnostic algorithm. A distribution study of these microcytic patients showed that there was a significant overlap of values between the IDA and non-IDA patients for all serum anemia tests. A receiver-operator curve analysis revealed that ZPP has a relatively high degree of diagnostic efficiency better than iron and ferritin for this patient population. At a cutoff value > 170 mu mol/mol heme, ZPP has a sensitivity of 93% and a specificity of 90%. In addition, ZPP is also elevated in normocytic patients (MCV = 80-98 fl) with low ferritin values, who may have iron depletion. From these data, it is proposed that ZPP may be used as a screening tool for IDA in hospitalized patients.     

Daubert v. Merrell Dow and expert testimony by clinical psychologists: Implications and recommendations for practice.

The role and practice of clinical psychologists as expert witnesses is discussed in light of the United States Supreme Court decision in Daubert v. Merrell Dow Pharmaceuticals (1993). Daubert v. Merrell Dow is reviewed, and its implications for clinicians who testify as expert witnesses are presented. A distinction is made between expert testimony in a generic sense, and scientific expert testimony. By virtue of clinical psychology's adoption of the mantle of science, clinical psychologists should adhere to scientific standards of data gathering in order to qualify as scientific experts. Guidelines are provided to assist clinicians in assessing the confidence with which conclusions can be termed scientific, and ethical concerns are reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preemployment predictors of union attitudes: The effects of parental union and work experiences.

Tested an expanded model of the socialization of union attitudes using data from 120 undergraduates and their parents. As hypothesized, students' perceptions of parental union attitudes, union participation and job satisfaction were significantly predicted by parental self-reports. Moreover, tests of three competing models suggested that student perceptions mediated the relationships between parental work and union experiences and students' own union attitudes and work beliefs. These findings are taken as support for the family socialization of work beliefs and union attitudes. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)