Genome-Wide Association Studies Identified Three Independent Polymorphisms Associated with α-Tocopherol Content in Maize Kernels

Tocopherols are a class of four natural compounds that can provide nutrition and function as antioxidant in both plants and animals. Maize kernels have low α-tocopherol content, the compound with the highest vitamin E activity, thus, raising the risk of vitamin E deficiency in human populations relying on maize as their primary vitamin E source. In this study, two insertion/deletions (InDels) within a gene encoding γ-tocopherol methyltransferase, Zea mays VTE4 (ZmVTE4), and a single nucleotide polymorphism (SNP) located ∼85 kb upstream of ZmVTE4 were identified to be significantly associated with α-tocopherol levels in maize kernels by conducting an association study with a panel of ∼500 diverse inbred lines. Linkage analysis in three populations that segregated at either one of these three polymorphisms but not at the other two suggested that the three polymorphisms could affect α-tocopherol content independently. Furthermore, we found that haplotypes of the two InDels could explain ∼33% of α-tocopherol variation in the association panel, suggesting ZmVTE4 is a major gene involved in natural phenotypic variation of α-tocopherol. One of the two InDels is located within the promoter region and associates with ZmVTE4 transcript level. This information can not only help in understanding the underlying mechanism of natural tocopherol variations in maize kernels, but also provide valuable markers for marker-assisted breeding of α-tocopherol content in maize kernels, which will then facilitate the improvement of maize as a better source of daily vitamin E nutrition

Dipeptidyl peptidase-1 inhibition in patients hospitalised with COVID-19: a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial

Background Neutrophil serine proteases are involved in the pathogenesis of COVID-19 and increased serine protease activity has been reported in severe and fatal infection. We investigated whether brensocatib, an inhibitor of dipeptidyl peptidase-1 (DPP-1; an enzyme responsible for the activation of neutrophil serine proteases), would improve outcomes in patients hospitalised with COVID-19. Methods In a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial, across 14 hospitals in the UK, patients aged 16 years and older who were hospitalised with COVID-19 and had at least one risk factor for severe disease were randomly assigned 1:1, within 96 h of hospital admission, to once-daily brensocatib 25 mg or placebo orally for 28 days. Patients were randomly assigned via a central web-based randomisation system (TruST). Randomisation was stratified by site and age (65 years or ≥65 years), and within each stratum, blocks were of random sizes of two, four, or six patients. Participants in both groups continued to receive other therapies required to manage their condition. Participants, study staff, and investigators were masked to the study assignment. The primary outcome was the 7-point WHO ordinal scale for clinical status at day 29 after random assignment. The intention-to-treat population included all patients who were randomly assigned and met the enrolment criteria. The safety population included all participants who received at least one dose of study medication. This study was registered with the ISRCTN registry, ISRCTN30564012. Findings Between June 5, 2020, and Jan 25, 2021, 406 patients were randomly assigned to brensocatib or placebo; 192 (47·3%) to the brensocatib group and 214 (52·7%) to the placebo group. Two participants were excluded after being randomly assigned in the brensocatib group (214 patients included in the placebo group and 190 included in the brensocatib group in the intention-to-treat population). Primary outcome data was unavailable for six patients (three in the brensocatib group and three in the placebo group). Patients in the brensocatib group had worse clinical status at day 29 after being randomly assigned than those in the placebo group (adjusted odds ratio 0·72 [95% CI 0·57–0·92]). Prespecified subgroup analyses of the primary outcome supported the primary results. 185 participants reported at least one adverse event; 99 (46%) in the placebo group and 86 (45%) in the brensocatib group. The most common adverse events were gastrointestinal disorders and infections. One death in the placebo group was judged as possibly related to study drug. Interpretation Brensocatib treatment did not improve clinical status at day 29 in patients hospitalised with COVID-19

The fear of happiness : exploring its antecedents and consequences on well-being

Although people generally prefer being happy than unhappy, research suggests that certain individuals might possess a fear of happiness, and that such fear might be more prominent in certain cultures (Joshanloo et al., 2014). The current study aimed to examine the explanatory mechanisms involved in the antecedent and consequences of fear of happiness. Based on previous cross-cultural research (Markus & Kitayama, 1991), I examined independent and interdependent self-construal, and the associated dialectical thinking style as the antecedent mechanism of fear of happiness. Based on previous research on emotion regulation (Bryant & Veroff, 2007; Nelis et al., 2010), I examined dampening of positive emotions as the explanatory mechanism for the consequences of fear of happiness on well-being. Undergraduates in Singapore (N = 117) completed self-reports on independent and interdependent self-construal, dialectical thinking, fear of happiness, dampening of positive emotions, and four well-being measures – affect, life satisfaction, psychological well-being, and integrative well-being. Mediation analyses showed that interdependent self-construal did not predict fear of happiness. However, lower independent self-construal predicted higher dialectical thinking, which in turn predicted higher fear of happiness. Also, higher fear of happiness predicted increased dampening of positive emotions, which in turn predicted lower positive affect. Although similar results were found on the other three measures of well-being, the effects were no longer significant after controlling for affect. Results demonstrated the cognitive mechanisms involved in the antecedent and consequences of fear of happiness. Theoretical and practical implications for cultural research on fear of happiness and well-being will be discussed.Bachelor of Art

Inconsistent media mediation and problematic smartphone use in preschoolers: Maternal conflict resolution styles as moderators

Ministry of Social and Family Development, Singapore

Hierarchical Auto-Ignition and Structure-Reactivity Trends of C2–C4 1-Alkenes

Ignition delay times of small alkenes are a valuable constraint for the refinement of the core kinetic mechanism of hydrocarbons used in representing combustion properties of real fuels. Moreover, the chemical reactivity comparison of those small alkenes provides a reference in object-oriented fuel design and logical combustion utilization. In this study, the ignition delay times of C2–C4 alkenes (ethylene, propene and 1-butene) were measured behind reflected shock waves first, with a fixed oxygen concentration (XO2 = 6%) and equivalence ratio (φ = 1.0) at various pressures of 1.2, 4.0 and 16.0 atm, in order to facilitate the comparison. Three chemical-based-Arrhenius-type correlations covering a wide range of temperature, pressure, equivalence ratio, and dilution were proposed. The simplified reaction network for pyrolysis and oxidation of 1-alkenes was depicted relying on the reaction classes of alkenes. Nine generally accepted mechanisms were used to simulate the ignition delay times measured by this study as well as literature. All the kinetic models show reasonable structure-reactivity trends for all of the three alkenes, but only NUIGMech 1.1 is capable of representing quantificationally the chemical reactivity at all tested conditions. Generally, ethylene exhibits the highest reactivity while propene presents the lowest at high temperatures. Analyses of sensitivity and flux indicate that the main oxidation pathway of ethylene is chain-branching, which accelerates the accumulation of free radical pools, especially for the Ḣ atom, Ȯ atom and ȮH radical, which results in the highest reactivity of ethylene. For propene and 1-butene, due to the presence of the allylic site, consumption of allylic radicals becomes the decisive step of oxidation and allylic radicals are mostly consumed by the HȮ2 radical. However, there are no such efficient reaction pathways for the formation of HȮ2 radicals during the propene oxidation process, while reaction pathways for HȮ2 formation in 1-butene are efficient. Thus, 1-butene presents higher reactivity compared to propene

Multidimensional predictors of adolescents’ nonacademic digital media use in the United States: Insights from a bioecological perspective

Using the revised bioecological model, we examined whether three broad factors predict adolescents’ nonacademic media use, with the exception of TV: (a) process factors that highlight a child’s fundamental and proximal interactional activities (e.g., eating meals together); (b) person factors (e.g., age, sex, ethnicity); and (c) contextual factors that delineate a child’s immediate physical and social environments (such as family, school, and community). By analyzing a nationally representative cohort (N = 22,454) of U.S. parents/primary caregivers who completed surveys regarding their children, we identified specific process-person-contextual factors that predict adolescents’ nonacademic screen time. Factors that positively predict screen time include, e.g., age, sex, ethnicity, BMI, anxiety. Those that negatively predict screen time include, e.g., sleep, physical activity, father’s physical health, mother’s mental health, eating meals together, sharing ideas with parents, the child’s active participation in school activities and community service, school safety, and emotional support for parents. Further, we found one age-related developmental process; the beneficial impact of meal sharing on media use was more pronounced in younger adolescents. This underscores the importance of exploring not only individual characteristics but also the broader process and contextual factors that shape adolescents’ nonacademic media use. Prior research on adolescents’ screen time primarily examined risk or protective factors at the individual level. In contrast, understanding the nuanced interplay among individual, familial, and broader contextual factors in shaping nonacademic media consumption is limited. We identified a comprehensive but understudied group of process, personal, and contextual factors and their intricate interactions that are pivotal in adolescents’ media use. We also made critical theoretical contributions regarding family functioning in the promotion of healthy media practices. Our results have important implications for effective and holistic interventions that support healthy media-use practices in adolescents. These include the promotion of adolescents’ self-regulatory skills, healthy family lifestyles at home, and diverse activities at school and within the community.</p

Comparative Study on Autoignition Characteristics of Methylcyclohexane and Cyclohexane

Ignition delay times were measured behind reflected shock waves for cyclohexane and methylcyclohexane at pressures of 1.1, 5.0, and 16.0 atm, temperatures from 1075 to 1750 K, and equivalence ratios of 0.5, 1.0, and 2.0. Correlations of the ignition delay times were performed at the three equivalence ratios in Arrhenius form. Measured ignition delay times showed fairly good agreements with previous data. Several accepted mechanisms (JetSurF 2.0, Wang et al., Sirjean et al., Orme et al., and Silke et al.) were used to simulate the experimental measurements and conduct flux analyses and sensitivity analyses. Comparisons of the simulations and analyses between the mechanisms give insights into the oxidation of methylcyclohexane and cyclohexane. Methylcyclohexane has an evidently longer ignition delay time than cyclohexane at ϕ = 0.5, while its ignition delay time becomes comparative to those of cyclohexane at ϕ = 1.0. Chemical kinetic interpretation is given for this observation