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151.
The fingernail ridge patterns of a pair of identical twins were compared to each other, their parents, and an unrelated subject. The patterns of the twins' nails showed regions of strong similarity but were distinguishable from one another. Fewer similarities were found when comparing the nails to those of the parents and the unrelated control. The twins were shown to be monozygotic by means of DNA profiling. This therefore represents the first demonstration of unique fingernail ridge patterns in subjects shown conclusively to be identical twins. When the fingernail ridge patterns were examined with a scanning electron microscope, the backscattered electron (BEI) images were found to have superior contrast when compared to the secondary electron (SEI) images.  相似文献   
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Using merged administrative data from welfare reform evaluations in three states, we estimate the effects of child care subsidy use on the length of time it takes for a welfare applicant to move into substantial employment. Findings show that the use of a child care subsidy during an unemployed or marginally employed spell of welfare receipt is associated with between a 0.6 and 1.7 quarter (or 11% to 34%) reduction in the time to substantial employment in two of the three state samples. The positive influence of subsidy use on transitions to substantial employment is strongest for those welfare applicants with the lowest earnings who are mixing welfare and work prior to subsidy receipt.  相似文献   
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Although past research has developed scales for the incidence, prevalence, and fear of student-on-student victimization (SSV), little is known about the scaling of perceived risk (i.e., the cognitive appraisal of the chances of experiencing SSV). Hence, this study examined self-report survey data for the perceived risk of SSV as measured in the Adolescent Index for School Safety (AISS). Children in grades 7 through 10 (n=337) in a single Florida public school completed the AISS. Factor analyses using Maximum Likelihood Estimation with Oblimin Rotation identified nine unique factors for perceived risk. Reliability analyses found standardized Cronbach Alphas that ranged from .64 to .91, and seven out of the nine identified scales were above .80, which suggested good to excellent internal consistency. Future research should examine the content validity, construct validity, and predictive validity for the AISS and other self-report surveys of SSV dynamics. This publication was made possible by a grant [#97-MU-FX-KO12 (S-l)] from the Office of Juvenile Justice and Delinquency Prevention (O.J.J.D.P.), United States Department of Justice (U.S.D.O.J.). This grant is administered through the Hamilton Fish National Institute on School and Community Violence at George Washington University. This specific study was developed and implemented by staff at: 1) East Carolina University’s Department of Criminal Justice; and 2) Florida State University’s Center for Educational Research and Policy Studies. All points of view and opinions in this paper are those of the authors and do not necessarily represent the official position or policies of East Carolina University, Florida State University, the Hamilton Fish National Institute on School and Community Violence, the O.J.J.D.P., or the U.S.D.OJ. The authors would also like to thank Dr. Bill Doerner and Jennifer Jolley for their support, editorial feedback, and insightful comments regarding earlier drafts of this paper.  相似文献   
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