Locke on Real Essences, Intelligibility, and Natural Kinds

In this paper I criticize the interpretations of John Locke on natural kinds offered by Matthew Stuart and Pauline Phemister who argue that Locke’s Essay Concerning Human Understanding allows for natural kinds based on similar real essences. By contrast, I argue for a conventionalist reading of Locke by reinterpreting his account of the status of real essences within the Essay and arguing that Locke denies that the new science of mechanism can justify the claim that similarities in corpuscular structure imply similarities in sensible qualities. I argue further that Locke rejects as meaningless any talk of kinds that appeals to similarities among real essences. On my reading of Locke, similarities in real essences are not only irrelevant to species, but natural kind theories based on themare unintelligible

Retrospective cohort study of false alarm rates associated with a series of heart operations: the case for hospital mortality monitoring groups

OBJECTIVE: To examine the efficacy of different methods of detecting a high death rate and determining whether an increase in deaths after heart transplantation could be explained by chance. DESIGN:Retrospective analysis of deaths after heart transplantation. Seven methods were used: mortality above national average, mortality excessively above national average, test of moving average mortality, test of number of consecutive deaths, sequential probability ratio test (SPRT), cusum graph with v-mask, and CRAM chart. The national average mortality was not available and a rate of 15% was used instead as the benchmark. SETTING: Regional cardiothoracic unit. PARTICIPANTS: All 371 patients who received a heart transplant in the programme, 1986-2000. MAIN OUTCOME MEASURES: 30 day survival after transplantation. RESULTS: All methods provided evidence that the 30 day mortality had been high at some stage. The probability that the finding was a false positive depended on which test was used. At the end of the series the average mortality, sequential probability ratio, and cusum tests indicated a level of deaths higher than the benchmark while the remaining four tests yielded negative results. CONCLUSIONS:If the decision to test for outlying mortality is made retrospectively, in the light of the data, it is not possible to determine the false positive rate. Prospective on-site mortality monitoring with the CRAM chart is recommended as this method can quantify the death rate and identify periods when an audit of cases is indicated, even when data from other institutions are not available. A hospital mortality monitoring group can routinely monitor all deaths in the hospital, by specialty, using hospital episode statistics (HES) data and appropriate statistical methods

Quantifying the effects of soil erosion on crop productivity

The effects of soil erosion on yield and root development were determined for soybean (Glycine max (L.) Merr.) (1984) and corn (Zea mays L.) (1985) grown on Grenada silt loam (Glossic Fragiudalfs) in West Tennessee. Seven sites were selected in a cropped field where depth to the fragipan ranged from 0 to 107 cm below the soil surface. To verify the deep sites were relatively uneroded, selected physical and chemical properties of the 107 and 15 cm sites were compared to an area of Grenada silt loam in Crockett County, Tennessee with no history of cultivation. Across-the-site comparisons involving bulk density, soil color, exchangeable Na, and organic matter indicated that profile modification at the experimental sites had occurred as a result of soil erosion. Soils were sampled to either 90 or 120 cm depths in 15 cm increments at six points each within the row and 25 and 51 cm from the row; subsamples were composited by each depth increment. Four such samplings were made for each site. Roots were extracted and total root length was determined by the line-intercept method. Greater total root lengths were observed with increasing depth to the fragipan. Crop yields were correlated with total root length. Soybean yields ranged from 2.8 Mg ha-1 on the 107 cm site to 0.5 Mg ha-1 on the 0 cm site, whereas, corn yields ranged from 10.0 Mg ha-1 to 5.5 Mg ha-1 from the 107 cm site to the 0 cm site, respectively

Masculinity, femininity, & androgyny : the interaction of college students with preschoolers

The rel ationshi p between sex-typing and the interacti on of col l ege students with 2- to 4-year-ol d male and female children was examined. Seventy-one Introductory Psychol ogy students were admini stered the Bern Sex-Role Inventory (BSRI), which was scored in terms of the 7 factors introduced by Walker & Preston (1979). Small groups of 3 and 4 individuals were randomly selected to spend 20 minutes in the Child Development Lab, where they had the opportunity to interact with the children, to play with the toys, to observe, and to inter­ act with each other. The behavior of each individual within the groups of students was recorded by trained raters observing through a 1 -way mirror. Although it was predicted that the factors of Nurturance and Autonomy would account for the majority of the variance, a canonical correlation failed to indicate significant results. Results are discussed in terms of the behavioral observation technique employed, the predicting value of the BSRI, and implications for future research