Helpful Homework in Geometry: A Redesigned Circles Unit

Homework has been part of the educational system for many decades. During this time, public opinion has varied greatly on its usefulness in the classroom. Much of the more recent research has focused on the idea that homework can be valuable to students when the assignments are meaningful, as opposed to homework that is assigned with little or no purpose. This research was analyzed to find patterns in the various definitions of meaningful homework. It was found that meaningful homework generally contains the following qualities: brevity, choice, defined purpose, real-world connections, hands-on components, rigor through synthesis, the integration of technology or web-based activities, opportunities for family involvement, and the substantial incorporation of previously taught topics. Based on these findings, a Geometry unit on circles was redesigned to combine these elements into practical lessons, as an example to educators of how to begin making homework more constructive in the mathematics classroom

Investigation of a novel reductively-activatable anticancer prodrug of \u3cem\u3eseco\u3c/em\u3e-CBI-TMI, an analog of duocarmycin SA

A bioreductively-activated prodrug of seco-CBI-TMI, compound 1, was designed to take advantage of the reductive environment characteristic of hypoxic tumors and selectively deliver a cytotoxin to these sites. The novel quinone-based prodrug I and its nitrophenol analog were prepared, and upon reduction, uv-vis, cv, and NMR studies confirmed the release of the free drug moiety. However, cellular studies of prodrug 1 did not show an increase in cytotoxic potency in cell lines containing the reducing enzyme DT diaphorase, possibly due to a premature activation of prodrug 1 in cell culture media

The reliability of glomerular filtration rate measured from plasma clearance: a multi-centre study of 1,878 healthy potential renal transplant donors

PURPOSE The objective of the study was to undertake a clinical audit of departmental performance in the measurement of glomerular filtration rate (GFR) using the coefficient of variation (CV) of extracellular fluid volume (ECFV) as the benchmark. ECFV is held within narrow limits in healthy subjects, narrower than GFR, and should therefore have a low CV. METHODS Fifteen departments participated in this retrospective study of healthy renal transplant donors. Data were analysed separately for men (n ranged from 28 to 115 per centre; total = 819) and women (n = 28-146; 1,059). All centres used the slope-intercept method with blood sample numbers ranging from two to five. Subjects did not fast prior to GFR measurement. GFR was scaled to body surface area (BSA) and corrected for the single compartment assumption. GFR scaled to ECFV was calculated as the terminal slope rate constant and corrected for the single compartment assumption. ECFV/BSA was calculated as the ratio of GFR/BSA to GFR/ECFV. RESULTS The departmental CVs of ECFV/BSA and GFR/BSA ranged from 8.3 to 25.8% and 12.8 to 21.9%, respectively, in men, and from 9.6 to 21.1% and 14.8 to 23.7%, respectively, in women. Both CVs correlated strongly between men and women from the same centre, suggesting department-specific systematic errors. GFR/BSA was higher in men in 14 of 15 centres, whereas GFR/ECFV was higher in women in 14 of 15 centres. Both correlated strongly between men and women, suggesting regional variation in GFR. CONCLUSION The CV of ECFV/BSA in normal subjects is a useful indicator of the technical robustness with which GFR is measured and, in this study, indicated a wide variation in departmental performance