Common breaks in time trends for large panel data with a factor structure

In this paper, I analyse issues related to the estimation of a common break in a large panel of time series data. Each series in the panel consists of a linear time trend and a random error. The linear time trend is subject to a break that occurs at the same date for all series. The error term is cross‐sectionally correlated through a factor structure. The break date is estimated jointly with the common factors. In particular, two break date estimators are analysed: the first is obtained as an iterative solution while the second is obtained as a global solution. The asymptotic properties of these estimators are analysed under both global and local asymptotic frameworks. These two estimators are shown to be asymptotically equivalent and to achieve a faster rate of convergence than the simple break date estimator that does not take common factors into account. The limiting distributions of the proposed break date estimators are provided so that asymptotically valid confidence intervals can be formed. Monte Carlo simulation results are provided to support the theoretical results.     

The Canadian war on drugs: Structural violence and unequal treatment of Black Canadians

This paper examines the impact of Canada's war on drugs on segments of the Black community, specifically with respect to the impact of structural violence, over-policing, and high incarceration rates. It offers evidence of the systemic nature of these dynamics by examining the early context of the war, growing stigma against Blacks, globalizing influences, and the punitive focus of funding and policy. The paper also explores how Black men have been identified as the main enemy and how drug control efforts have served to diminish the health, well-being, and self-image of Black men via discriminatory and inequitable treatment before the law. The current high rates of imprisonment of Black men are an indicator of systematic deprivation of significant social capital, which will perpetuate socioeconomic harm and cycles of violence. This commentary calls for an immediate dissolution of policies regulating the war on drugs as the first step in remedying the injustices experienced by Black Canadians. Due to the lack of Canadian data in this important area, the paper also emphasizes the critical need for more research to shed more light on the Canadian-specific complexities.     

Separate and unequal: Structural racism and infant mortality in the US

We examined associations between state-level measures of structural racism and infant mortality among black and white populations across the US. Overall and race-specific infant mortality rates in each state were calculated from national linked birth and infant death records from 2010 to 2013. Structural racism in each state was characterized by racial inequity (ratio of black to white population estimates) in educational attainment, median household income, employment, imprisonment, and juvenile custody. Poisson regression with robust standard errors estimated infant mortality rate ratios (RR) and 95% confidence intervals (CI) associated with an IQR increase in indicators of structural racism overall and separately within black and white populations. Across all states, increasing racial inequity in unemployment was associated with a 5% increase in black infant mortality (RR=1.05, 95% CI=1.01, 1.10). Decreasing racial inequity in education was associated with an almost 10% reduction in the black infant mortality rate (RR=0.92, 95% CI=0.85, 0.99). None of the structural racism measures were significantly associated with infant mortality among whites. Structural racism may contribute to the persisting racial inequity in infant mortality.     

Molecular characterization,isolation, pathology and pathotyping of peafowl (Pavo cristatus) origin Newcastle disease virus isolates recovered from disease outbreaks in three states of India

Disease outbreak investigations were carried out in three states of Northern India namely Haryana (Rewari), Uttar Pradesh (Noida) and Delhi, where a total of 110 Indian peafowls (Pavo cristatus) showed sudden onset of nervous signs and died within a period of two weeks during June, 2012. The F (fusion) gene-based RT-PCR detection of Newcastle disease virus (NDV) in affected tissues confirmed the presence of the virus. Three NDV isolates were selected (one from each area under investigation) and further characterized. They were found to be of virulent pathotype (velogenic NDV) based on both pathogenicity assays (MDT, ICPI and IVPI) and partial F gene sequence analysis. Additionally, the phylogenetic analysis revealed that the isolates belonged to the genotype VIIi and XIII of class II avian Paramyxovirus serotype1 (APMV-1) and related closely to new emerging sub-genotypes. This is the first report regarding the presence of the fifth panzootic vNDV genotype VIIi from India. In this scenario, extensive epidemiological studies are suggested for surveillance of NDV genotypes in wild birds and poultry flocks of the country along with adopting suitable prevention and control measures.     

Biochemical and molecular characterization of a new sporadic glucose-6-phosphate dehydrogenase variant described in Italy: G6PD Modena

Summary. A new glucose-6-phosphate dehydrogenase variant detected in an Italian man from the Po delata is described and designated as G6PD Modena. Biochemical characterization of the variant enzyme revealed an activity 21% of normal, a slow electrophoretic mobility, increased K_m value for NADP, decreased K_m value for G6P and a complete absence of NADPH inhibition, which could account for the apparently nonhaemolytic feature of this variant. The cloning and sequencing of the G6PD Modena allele showed a GC transition at nucleotide 844 in exon VIII causing a Asp His amino acid substitution. On the basis of biochemical characterization, G6PD Modena is classified as a genuine variant but it has the same mutation as G6PD Seattle-like.     

Social support,resilience, and self-esteem protect against common mental health problems in early adolescence: A nonrecursive analysis from a two-year longitudinal study

The aim of this study is to examine the mutual effects of self-esteem and common mental health problems (CMHPs) as well as the mutual effects of self-esteem and resilience in early adolescence. The recruited participants were 1015 adolescents aged 12.7 years (SD = 0.5 years) from two junior high schools. Data were repeatedly collected at five time points at 6-month intervals over 2-year years. The Social Support Rating Scale (SSRS), Block and Kremen''s Ego-Resiliency Scale (ER89), Rosenberg Self-esteem Scale (RSES), and Mental Health Inventory of Middle School Students (MMHI-60) were used to measure social support, resilience, self-esteem, and CMHPs, respectively. Nonrecursive structural equation modeling (SEM) was performed to analyze the data.There were bivariate partial correlations among the five-time measurements for the SSRS, ER89, RSES, and MMHI-60 scores. Self-esteem negatively predicted CMHPs with a standardized direct effect of −0.276 (95% CI: −0.425 to −0.097), and the opposite effect was −0.227 (95% CI: −0.383 to −0.072). Self-esteem positively predicted resilience with the standardized direct effect of 0.279 (95% CI: 0.093–0.425), and the opposite effect was 0.221 (95% CI: 0.063–0.376). Social support was a protective factor for mental health status.The findings of mutual effects of self-esteem and CMHPs as well as self-esteem and resilience can provide researchers and practitioners with a conceptual framework that can help them build effective intervention methods to promote adolescent mental health status.