RESUMO
BACKGROUND: Bullying is a widespread phenomenon that has captured attention from mental health researchers. Several studies have assessed bullying prevalence with some methodological concerns. OBJECTIVES: Preliminary, we analyzed the psychometric properties of two bullying scales for victimization (the multidimensional peer victimization scale - MPVS) and for perpetration (the bully subscale of the Illinois bully scale - IBS-B); then, we estimated bullying prevalence; finally, we evaluated the effect of gender and classroom on the phenomenon. PARTICIPANTS AND SETTING: 2959 students from the metropolitan city of Naples constituted the sample. METHODS: Data collection was obtained using a multi-assessment approach that included both single-item questions and intensity scales in order to compare the two methods. RESULTS: The two scales resulted valid and showed good reliability. The MPVS displayed a 1-factor second order model. The IBS-B had a mono-factorial structure. Both showed full invariance for gender and classroom. Prevalence of victimization was 37% whereas that for perpetration was 21%. As expected we obtained several bullying prevalence results depending on the specificity of questions and in particular repetitiveness of episodes. There was a good correspondence between results of single-item questions and multi-item scales. Finally results demonstrated several differences for gender and classroom attended. CONCLUSION: In this epidemiological study the multi-assessment approach identified different but complementary features of bullying phenomena. The use of the two measurement approaches allowed us to obtain more precise and exhaustive information on bullying prevalence and compare it with previous findings.
Assuntos
Bullying/estatística & dados numéricos , Vítimas de Crime/psicologia , Adolescente , Análise de Variância , Bullying/psicologia , Criança , Feminino , Humanos , Illinois , Masculino , Saúde Mental , Avaliação de Resultados em Cuidados de Saúde , Grupo Associado , Prevalência , Psicometria , Reprodutibilidade dos Testes , Estudantes/psicologiaRESUMO
BACKGROUND: High resolution melting (HRM) analysis of PCR amplicons was recently introduced as a closed-tube, rapid, and inexpensive method of genotyping. This study evaluated this system as an option for detecting the three most common mutations in the HFE gene (C282Y, H63D, S65C), accounting for the main form of hereditary haemochromatosis. METHODS: Ninety samples, previously screened by direct sequencing, and 27 controls were used. The analysis were performed on the Rotor Gene Q, using the commercial HRM mix containing the Eva Green dye (Qiagen). Specific primers allowed the amplification of the regions of interest in the HFE gene. Following amplification, a HRM analysis was conducted to detect DNA variants. The thermal denaturation profiles of the samples were compared with those of the controls. RESULTS: One hundred percent of heterozygous and homozygous samples were readily identified. Heterozygotes were easily identified because heteroduplexes altered the shape of the melting curves, but significant differences were also present in the melting curves of the homozygous carries compared with those of the wild-type subjects. CONCLUSIONS: HRM analysis is an appealing technology for HFE gene screening. It is a robust technique that can be widely adopted in diagnostic laboratories to facilitate gene mutation screening.