16 Multiple Linear Regression Viewpoints

This paper analyzes two methods for testing moderation effects in regression models that contain a continuous dependent variable, a continuous independent variable, and a dichotomized grouped moderator; a test of the interaction term in the full regression model and a test of the difference between the simple slopes. Typically, researchers test the significance of the interaction term. Based on mathematical equations and empirical examples, we argue that the test for the difference between the simple slopes should be utilized when researchers are interested in testing for moderation effects. By decomposing the test statistics for these two methods, we demonstrate that the test for the difference between the simple slopes has increased power and less Type II error, while retaining equivalent Type I error rates. oderated relationships in social science research exist when the relationship between two variables, X and Y, varies depending on the value of a third variable Z. This study examines a specific type of moderated relationship with a continuous dependent variable (Y), a continuous independent variable (X), and an independent dichotomous categorical variable (Z). Given these variables, a moderated relationship exists if the relationship between X and Y is different for both levels of Z. This can be estimated with an interaction term using the following regression equatio

Development of the multidimensional peer victimization scale–revised (MPVS-R) and the multidimensional peer bullying scale (MPVS-RB)

Peer victimization is a frequent occurrence for many adolescents; however, some of the psychometric properties of self-report scales assessing these experiences remain unclear. Furthermore, with an increase in access to technology, electronic aggression should also be considered. The study examined the psychometric properties of the Multidimensional Peer Victimization Scale (MPVS, Mynard & Joseph, 2000), and developed versions to include the assessment of electronic aggression according to whether the adolescent was the target or perpetrator of peer victimization. Three hundred and 71 (191 girls and 180 boys Mage = 13 years 4 months, SDage= 1 year 2 months) adolescents in the UK completed the MPVS including 5 newly developed items assessing electronic aggression, a version of the MPVS designed to assess victimization perpetration, and a measure of self-esteem. Confirmatory factor analyses yielded a five-factor structure comprising: Physical, social manipulation, verbal, attacks on property, and electronic for both scales. Convergent validity was established through negative associations between the victimization scales and self-esteem. Sex differences also emerged. One revised scale and one new scale are subsequently proposed: The Multidimensional Peer Victimization Scale - Revised (MPVS-R) and the Multidimensional Peer Bullying Scale (MPVS-RB)

Avaliação de linhagens elites de arroz irrigado do programa de melhoramento genético da Embrapa em ensaios de VCU no RS - safra 2011/11.

O objetivo deste trabalho foi avaliar o desempenho das linhagens geradas pelo programa de melhoramento genético da Embrapa, em diferentes regiões orizícolas do Rio Grande do Sul, visando possível lançamento de novas cultivares

Rah, rah, ROS: metabolic changes caused by loss of adhesion induce cell death

The high rate of glucose utilization by cancer cells has been well characterized. Recent data suggest that when normal mammary epithelial cells are cultured under nonadherent conditions, glucose consumption decreases, ATP levels fall, and concentrations of reactive oxygen species rise. The rise in reactive oxygen species causes death of nonadherent cells, which can be suppressed with antioxidants. Nonadherent ErbB2-transformed mammary epithelial cells maintain glucose transport and antioxidant production; however, antioxidants appear to enhance anchorage-independent growth. These findings integrate aspects of glucose metabolism, anoikis suppression and antioxidant production in tumor cell biology and suggest that antioxidant therapy could stimulate tumor survival

The initial measurement structure of the Home Drinking Assessment Scale (HDAS)

Aims: To evaluate the initial psychometric properties of a novel Home Drinking Assessment Scale (HDAS). Participants: Five-hundred and twenty-five (58% female) participants recruited from the internet address book of an English University. This also included a sub-sample (6%) recruited from Twitter and Facebook contacts. Design and methods: Internet-based survey analysed using a two-stage factor analysis protocol and internal consistency(IC) assessment. Findings: A power calculation was made on the basis of pilot data and this established that 317 interviewees were required to test the reliability of the HDAS. The items comprising the HDAS were found to offer the best fit to data when they comprised two-subscales: (1) emotional reasons for home drinking (5-items) and (2) practical reasons for home drinking (3-items). Subscale 1 was also found to have acceptable IC whereas subscale 2 exhibited sub-optimal IC characteristics. Conclusions: This initial study indicates that the HDAS has promise as a measure of the individuals' rationale for home drinking. Subscale 1, may usefully be used in future research whereas the IC characteristics of subscale 2 suggests that further development is required, including the evaluation of additional items

Maturation, Peer Context, and Indigenous Girls\u27 Early-Onset Substance Use

This paper examines a biosocial model of the impact of puberty on Indigenous girls\u27 early-onset substance use by considering the potential mediating role of peer context (i.e. mixed-sex peer groups and substance use prototypes) on the puberty and substance use relationship. Data include responses from 360 girls of a common Indigenous cultural group residing on reservations/reserves in the upper Midwest and Canada. Results of structural equation modeling revealed that the statistically significant relationship between girls\u27 pubertal development and early-onset substance use was mediated by both mixed-sex/romantic peer groups and favorable social definitions of substance use. Implications for substance use prevention work include addressing the multiple and overlapping effects of peer influence from culturally-relevant perspectives

Bullying behaviors and victimization experiences among adolescent students: the role of resilience

The role of resilience in the relationship between bullying behaviours, victimisation experiences, and self-efficacy was examined. Three hundred and 93 (191 male, 202 female) adolescents (mean age = 15.88, SD = .64) from schools in Coimbatore, India completed scales to assess bullying behaviours and victimisation experiences, resilience, and self-efficacy. Multigroup SEM, with separate groups created according to participant sex, revealed that resilience mediated the relationship between bullying behaviours and self-efficacy in males. Males engaged in bullying behaviours and experienced victimisation more frequently than females. The findings of the study have implication for designing intervention programs to enhance resilience among adolescents and young adults to enable them to manage bullying behaviours

Disruption of mitochondrial complex I induces progressive parkinsonism

Loss of functional mitochondrial complex I (MCI) in the dopaminergic neurons of the substantia nigra is a hallmark of Parkinson’s disease1. Yet, whether this change contributes to Parkinson’s disease pathogenesis is unclear2. Here we used intersectional genetics to disrupt the function of MCI in mouse dopaminergic neurons. Disruption of MCI induced a Warburg-like shift in metabolism that enabled neuronal survival, but triggered a progressive loss of the dopaminergic phenotype that was first evident in nigrostriatal axons. This axonal deficit was accompanied by motor learning and fine motor deficits, but not by clear levodopa-responsive parkinsonism—which emerged only after the later loss of dopamine release in the substantia nigra. Thus, MCI dysfunction alone is sufficient to cause progressive, human-like parkinsonism in which the loss of nigral dopamine release makes a critical contribution to motor dysfunction, contrary to the current Parkinson’s disease paradigm.Electron microscopy tissue processing and imaging was performed at the Northwestern University Center for Advanced Microscopy, supported by NCI CCSG P30 CA060553 awarded to the Robert H. Lurie Comprehensive Cancer Center. This study was supported by grants from the Michael J. Fox Foundation (to D.J.S.), the JPB Foundation (to D.J.S.), the IDP Foundation (to D.J.S.), the Flanagan Fellowship (to P.G.-R.) and the European Research Council ERC Advanced Grant PRJ201502629 (to J.L.-B.)