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The purpose of this study was to examine in a sample of 11,516 secondary school students the extent to which different behavioral, emotional and cognitive problems (a) reflected one or more underlying common factors; (b) actually cooccurred; and (c) were single problems. Principal Component Analyses were performed and percentagewise techniques were used. PCA demonstrated that one or more general syndromes could not by far account for all of the variance of the variables. The results suggest the existence of adolescent subgroups with divergent comorbidity patterns: those who primarily report one single symptom; those who report concurrent symptoms either exclusively in the category of behavioral problems or exclusively in the category of emotional and cognitive problems; and those who report concurrent symptoms in both categories. This distinction between different subgroups has important theoretical, diagnostic, and treatment implications. 相似文献
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Kathleen C. Schwartzman 《拉美政治与社会》2001,43(2):115-146
The economic embargo against Cuba has been widely promoted as a way to hasten the end of the Castro regime. Historically, however, the connection between embargoes and regime change is mediated by a complex of political, social, and economic conditions. Labormarket bottlenecks and domestic elite opposition, decisive factors in the South African case, are absent from that of Cuba. This study uses the factors derived from an analysis of South Africa to compare the Cuban case and concludes that the embargo against Cuba cannot have its intended results. 相似文献
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S.F. Oliveira C.E. Guerra-Amorim R.S.S. Barcelos C.C. Gontijo M.E.C.G. Diniz M.N. Klautau-Guimarães 《Forensic Science International: Genetics Supplement Series》2008,1(1):228-229
In patrilineal societies, surnames and Y-specific haplotypes and haplogroups are expected to be correlated. This characteristic could help defining an initial pool of suspects in forensic genetics analysis. Here we evaluated this correlation in a sample of Central-Brazilian men. Surnames and Y-SNP haplogroup and Y-STR haplotype were analyzed in 55 pairs of Central-Brazilian men sharing surnames (n = 110). Seven haplogroups and thirty-two haplotypes have been observed, none correlated solely to any of the twenty-eight surnames represented here. In this sample, two men with the same surname showed a chance of 0.41 of sharing a Y-specific haplogroup. This chance is higher for surnames of intermediate frequencies, whereas rare surnames show distinct chances as zero and one. Observed results may be over-estimated due to a predominance of a specific haplogroup (P92R7 = 49%) in the sample, what makes it possible for two men with no coancestry to share this haplogroup. Considering STR, only three pairs of men shared haplotypes. The average difference between the haplotypes in each pair was 2.45 mutational steps. This relatively low correlation is due to some historical and cultural peculiarities of the country, what makes it improper for forensic purposes in Brazil. 相似文献
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