2,862 research outputs found
Bounds on Cubic Lorentz-Violating Terms in the Fermionic Dispersion Relation
We study the recently proposed Lorentz-violating dispersion relation for
fermions and show that it leads to two distinct cubic operators in the
momentum. We compute the leading order terms that modify the non-relativistic
equations of motion and use experimental results for the hyperfine transition
in the ground state of the ion to bound the values of the
Lorentz-violating parameters and for neutrons. The resulting
bounds depend on the value of the Lorenz-violating background four-vector in
the laboratory frame.Comment: Revtex 4, four pages. Version to match the one to appear in Physical
Review
Using Latent Class Analyses to Examine Health Disparities among Young Children in Socially Disadvantaged Families during the COVID-19 Pandemic
Rising income inequality is strongly linked to health disparities, particularly in regions where uneven distribution of wealth and income has long been a concern. Despite emerging evidence of COVID-19-related health inequalities for adults, limited evidence is available for children and their parents. This study aimed to explore subtypes of families of preschoolers living in the disadvantaged neighborhoods of Hong Kong based on patterns of family hardship and to compare their patterns of parenting behavior, lifestyle practices, and wellbeing during the COVID-19 pandemic. Data were collected from 1338 preschoolers and their parents during March to June 2020. Latent class analysis was performed based on 11 socioeconomic and disease indicators. Multivariate logistic regressions were used to examine associations between identified classes and variables of interest during the COVID-19 pandemic. Four classes of family hardship were identified. Class 1 (45.7%) had the lowest disease and financial burden. Class 2 (14.0%) had the highest financial burden. Class 3 (5.9%) had the highest disease burden. Class 4 (34.5%) had low family income but did not receive government welfare assistance. Class 1 (low hardship) had lower risks of child maltreatment and adjustment problems than Class 2 (poverty) and Class 3 (poor health). However, children in Class 1 (low hardship) had higher odds of suffering psychological aggression and poorer physical wellbeing than those in Class 4 (low income), even after adjusting for child age and gender. The findings emphasize the need to adopt flexible intervention strategies in the time of large disease outbreak to address diverse problems and concerns among socially disadvantaged families
Evidence of individual differences in the long-term social, psychological, and cognitive consequences of child maltreatment
Background: The prevalence and consequences of child maltreatment are alarming, but evidence from studies with long follow-up intervals are limited. This study examined the long-term consequences of child maltreatment in relation to age of onset and follow-up interval. / Methods: The exposed group comprised 63 individuals (aged 13â34 years) with a first-time diagnosis of child maltreatment between 2001 and 2010, whereas the unexposed group comprised 63 individuals who were matched upon gender, age of onset, follow-up period, and poverty status at the index hospital admission but had no medical records of maltreatment in Hong Kong. The participants completed a set of questionnaires on executive functions and mental health and provided blood samples for measurement of IL-6 and IL-10 levels during a health assessment session. / Results: Compared with the unexposed group, the exposed group reported poorer maternal care during childhood (β = â4.64, p < 0.001) and had lower family support (β = â2.97, p = 0.010) and higher inflammatory responses (IL-6: β = 0.15, p = 0.001; IL-10: β = 0.11, p = 0.011) at follow-up. Additionally, the associations of childhood maltreatment exposure with family support and maternal care differed by age of onset and the length of time since exposure. / Conclusions: This matched cohort study highlights childhood maltreatment as a risk factor for systemic inflammation and an indicator of suboptimal social environment, both of which could persist over a long period of time
A Longitudinal Study of the Relation between Childhood Activities and Psychosocial Adjustment in Early Adolescence
Background: Although an increasing body of research shows that excessive screen time could impair brain development, whereas non-screen recreational activities can promote the development of adaptive emotion regulation and social skills, there is a lack of comparative research on this topic. Hence, this study examined whether and to what extent the frequency of early-life activities predicted later externalizing and internalizing problems. Methods: In 2012/13, we recruited Kindergarten 3 (K3) students from randomly selected kindergartens in two districts of Hong Kong and collected parent-report data on childrenâs screen activities and parentâchild activities. In 2018/19, we re-surveyed the parents of 323 students (aged 11 to 13 years) with question items regarding their childrenâs externalizing and internalizing symptoms in early adolescence. Linear regression analyses were conducted to examine the associations between childhood activities and psychosocial problems in early adolescence. Results: Early-life parentâchild activities (β = â0.14, p = 0.012) and child-alone screen use duration (β = 0.15, p = 0.007) independently predicted externalizing problems in early adolescence. Their associations with video game exposure (β = 0.19, p = 0.004) and non-screen recreational parentâchild activities (β = â0.14, p = 0.004) were particularly strong. Conclusions: Parentâchild play time is important for healthy psychosocial development. More efforts should be directed to urge parents and caregivers to replace child-alone screen time with parentâchild play time
Associations between childhood maltreatment and psychiatric disorders: analysis from electronic health records in Hong Kong
There has been a lack of high-quality evidence concerning the association between childhood maltreatment and psychiatric diagnoses particularly for Axis II disorders. This study aimed to examine the association between childhood maltreatment exposure and Axis I and Axis II psychiatry disorders using electronic health records. In this study, the exposed group (nâ=â7473) comprised patients aged 0 to 19 years with a first-time record of maltreatment episode between January 1, 2001 and December 31, 2010, whereas the unexposed group (nâ=â26,834) comprised individuals of the same gender and age who were admitted into the same hospital in the same calendar year and month but had no records of maltreatment in the Hong Kong Clinical Data Analysis and Reporting System (CDARS). Data on their psychiatric diagnoses recorded from the date of admission to January 31, 2019 were extracted. A Cox proportional hazard regression model was fitted to estimate the hazard ratio (HR, plus 95% CIs) between childhood maltreatment exposure and psychiatric diagnoses, adjusting for age at index visit, sex, and government welfare recipient status. Results showed that childhood maltreatment exposure was significantly associated with subsequent diagnosis of conduct disorder/ oppositional defiant disorder (adjusted HR, 10.99 [95% CI 6.36, 19.01]), attention deficit hyperactivity disorder (ADHD) (7.28 [5.49, 9.65]), and personality disorders (5.36 [3.78, 7.59]). The risk of psychiatric disorders following childhood maltreatment did not vary by history of childhood sexual abuse, age at maltreatment exposure, and gender. Individuals with a history of childhood maltreatment are vulnerable to psychiatric disorders. Findings support the provision of integrated care within the primary health care setting to address the long-term medical and psychosocial needs of individuals with a history of childhood maltreatment
Spectral domain optical coherence tomography as an effective screening test for hydroxychloroquine retinopathy (the âflying saucerâ sign)
Use of nepafenac (NevanacÂŽ) in combination with intravitreal anti-VEGF agents in the treatment of recalcitrant exudative macular degeneration requiring monthly injections
Associations of family meals with adolescent perception of family relationship and compliance with parental guidance in Hong Kong: results of a representative cross-sectional survey
Family meals are beneficial for adolescent development, but evidence from Chinese populations has been limited. This study aimed to examine the associations between family meal frequency and adolescent perception of family relationship and compliance with parental guidance in Hong Kong. During the period from October to December 2016, a stratified random sample of 3359 students were recruited from 25 secondary schools in Hong Kong. Students completed questionnaires about family characteristics, relationship quality, and meal frequency by paper-and-pencil in class. Multiple regression analyses were conducted to examine the associations between family meal frequency and perceived family relationship and compliance with parental guidance overall and by subgroups. After adjusting for sociodemographic and school confounders, family breakfast and dinner frequency were significantly associated with adolescent compliance (breakfast: B = 0.07, p < 0.001; dinner: B 0.07, p < 0.001) and perception of family relationship (breakfast: B = 0.10, p < 0.001; dinner: B = 0.25, p < 0.001). Risk factors for infrequent family meals included older age, not born in Hong Kong, less educated fathers, and unmarried parents. Our findings support the associations of regular family meals with adolescent perception of high family bond and compliance with parental guidance. Interventions are needed to enhance quality family meal interactions in disadvantaged families
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