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151.
152.
When examining concentration relationships of doses it must be taken into account that hair growth is irregular. Hair growing from the shaved skin after a single dose of a certain drug cannot possibly contain the same concentration as hair after the same dose that has not been cut over a long period. Concentrations can even change during the hair growth in cases where the hair had been cut a couple of months before the hair sample was taken. The variations in the expected concentrations can exceed 20%. On the other hand, the evaluation of a hair tuft which has grown after the last drug consumption may be important in forensic cases where the hair which has grown earlier is not available. This may lead to misinterpretations at low concentrations. Expected concentrations are calculated assuming a telogen part of 10%. 相似文献
153.
Voting rights litigation requires ecological inference to estimatethe voting preferences of minority and nonminority groups withinthe electorate. Double regression has been the procedure mostcommonly employed for this purpose. This article presents thefirst formal examination of this procedure. The underlying structuralmodel reveals that double regression estimators are neitherunbiased nor consistent estimators of true within-group votepreferences or polarization. Simulations demonstrate that theycan substantially exaggerate the differences between minorityand nonminority vote choices when none are present, and dramaticallyunderstate them when differences exist. In sum, double regressioncannot meet conventional statistical standards for reliability.Consequently, it should be abandoned. 相似文献
154.
155.
The existing literature seriously misinterprets the available evidence on the predictability of high rate criminal offending
and thus the potential value of statistical treatment rules that impose stiffer punishments on offenders with higher predicted
risk of recidivism. The misinterpretation results from the failure to take account of the fact that the data used in existing
risk assessment exercises come from environments characterized by informal (and sometimes formal) attempts by judges and other
actors to base penal treatments on expected recidivism. Findings of little or no predictive power for baseline covariates
may simply indicate the efficient use of the available information. We lay out the problem in detail, provide examples from
several literatures and then consider general solutions to the problem.
相似文献
Jeffrey SmithEmail: |
156.
The long-term administration of clozapine could be verified by fine segmentation and analysis of single hairs of one person to examine the history of a multiple poisoning case. Segments of 1-2.5mm length were extracted by ultrasonification in 30 microl of the mobile phase (mixture of methanol+water, 50+50). By application of isocratic liquid chromatography and using narrow bore columns (Synergy Polar-RP, Phenomenex), an acceleration and miniaturization of the HPLC-MS-MS assay could be achieved. Total amounts of clozapine down to 30 fg (on column) and its desmethyl metabolite could be analysed in multiple reaction monitoring mode. According to typical sample amounts of approximately 16 microg, relevant hair concentrations higher than 1 pg/mg were detected. Significant and reproducible concentration profiles along the hair fibres revealed characteristic administration cycles. The administration time course - in particular the time of its termination - could be verified with a precision of a few days. The accuracy and reproducibility of the concentration profile was proven based on multiple investigations of single hairs. An individual hair growth rate of 0.55 mm/day was determined with a relative standard deviation of 8% by comparison of concentration profiles in hairs collected after a time span of 165 days. 相似文献
157.
Purpose
Using a time-series cross-sectional design, we estimated the effects of social disorganization on juvenile property crime rates in a predominately Latino, Texas-Mexico border region.Methods
Eighteen years of data from seven independent sources (Bureau of Economic Analysis, Bureau of Labor Statistics, Census Bureau, Texas State Demographer, Internal Revenue Service, Department of Agriculture Economic Research Service, and Uniform Crime Reports) were examined. Counties were utilized as the unit of analysis, and time-series cross-sectional regression models were estimated.Results
The analysis showed that per capita income was negatively related to juvenile crime in both rural and urban counties. Ethnic heterogeneity was positively related to the outcome in rural, but not urban, counties; while percent foreign-born was negatively related to juvenile crime in urban, but not rural, counties.Conclusions
The Latino experience, both native- and foreign-born, is important for improving our understanding how economic and social conditions relate to crime. Comparative analyses between distinct geographical environments, such as rural and urban counties, can yield insight how the local context interacts with social disorganization processes. 相似文献158.
We propose a genetic test for full sibship for a pair of carrion flies that could reveal the postmortem relocation of a corpse. A carrion fly larva is sometimes left behind when a corpse is moved. The discovery of full sibling larvae of approximately the same developmental stage at two locations would strongly suggest that a corpse was moved between those two sites. Distributions of pairwise comparisons of relatedness (R) coefficients were generated using amplified fragment length polymorphism profiles for nine samples of laboratory-generated full siblings as well as for a reference sample of nonfull sibling Phormia regina (Diptera: Calliphoridae). The mean relative R coefficient, a pairwise measure of the proportion of shared alleles, was 0.479 (±0.289 SD) for full siblings, close to the theoretical expectation of 0.5. A likelihood ratio (LR) test was based on observed distributions of R. R >0.55 corresponded to an LR >1000 favoring full sibship for that pair of individuals. 相似文献
159.
160.
Jeffrey A. Lefebvre 《中东政策》2012,19(2):117-133