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Bullying has been understudied among preschool children, especially those from Chinese American families. Previous research has also neglected the dimensional effects of psychological control on child bullying development. This study examined two psychological control dimensions, love withdrawal and guilt induction, and their effects on children's bullying aggressive behavior using a longitudinal design. Participants were first-generation Chinese American mothers (N = 133; mean age [Mage] = 37.82) and their preschool children (Mage = 4.48). Chinese immigrant mothers reported their psychologically controlling parenting and teachers rated children's bullying aggressive behaviors in the school setting. Confirmatory factor analyses were conducted to establish the psychometric properties and cross-wave measurement equivalence of the study constructs. Cross-lagged structural equation modeling analysis indicated that maternal love withdrawal prospectively predicted more bullying aggressive behavior, whereas guilt induction predicted less bullying aggressive behavior in children 6 months later. These results held after controlling for the initial level of children's problem behaviors and demographic variables (child age, gender, and maternal education). For child effects, child bullying aggressive behavior predicted more maternal guilt induction over time but not love withdrawal. Our findings highlight the importance of construct specificity and cultural context in understanding associations between parenting and child development.
Silk and carbon nanomaterials, such as graphene oxide, graphene, and carbon nanotubes, have complementary mechanical properties that feature superior toughness and strength, respectively. Different strategies have been devoted to developing silk/carbon nanocomposites, but challenges remain to fully integrate the mechanical advantages of these two components into one synergistic material system. In this article, we provide a critical summary of structure–mechanics relationships in silk/carbon nanocomposites and highlight the impact of the interaction between silk and carbon nanomaterials on mechanical properties of the hybrid materials. We describe the challenges involved and directions for future designs of silk/carbon nanocomposites.
Sodium bismuth titanate (NBT) and its solid solutions with other ABO3 perovskites are of great interest for lead-free ferroelectric and piezoelectric applications. In this article, we provide an introduction to the complex structure of NBT, including atomic displacements and nanoscale defects. We also review poling effects and properties as well as NBT-ABO3 phase equilibria. The interesting relaxor properties, frequency dispersion in dielectric permittivity, and field-induced structural phase transitions of these systems are discussed. Finally, we describe other functional, mechanical, and electrical properties of NBT.
Dengue is the fastest spreading mosquito-transmitted disease in the world. In China, Guangzhou City is believed to be the most important epicenter of dengue outbreaks although the transmission patterns are still poorly understood. We developed an autoregressive integrated moving average model incorporating external regressors to examine the association between the monthly number of locally acquired dengue infections and imported cases, mosquito densities, temperature and precipitation in Guangzhou. In multivariate analysis, imported cases and minimum temperature (both at lag 0) were both associated with the number of locally acquired infections (P < 0.05). This multivariate model performed best, featuring the lowest fitting root mean squared error (RMSE) (0.7520), AIC (393.7854) and test RMSE (0.6445), as well as the best effect in model validation for testing outbreak with a sensitivity of 1.0000, a specificity of 0.7368 and a consistency rate of 0.7917. Our findings suggest that imported cases and minimum temperature are two key determinants of dengue local transmission in Guangzhou. The modelling method can be used to predict dengue transmission in non-endemic countries and to inform dengue prevention and control strategies.
Lake-calving Yakutat Glacier in southeast Alaska, USA, is undergoing rapid thinning and terminus retreat. We use a simplified glacier model to evaluate its future mass loss. In a first step we compute glacier-wide mass change with a surface mass-balance model, and add a mass loss component due to ice flux through the calving front. We then use an empirical elevation change curve to adjust for surface elevation change of the glacier and finally use a flotation criterion to account for terminus retreat due to frontal ablation. Surface mass balance is computed on a daily timescale; elevation change and retreat is adjusted on a decadal scale. We use two scenarios to simulate future mass change: (1) keeping the current (2000–10) climate and (2) forcing the model with a projected warming climate. We find that the glacier will disappear in the decade before 2110 or 2070 under constant or warming climates, respectively. For the first few decades, the glacier can maintain its current thinning rates by retreating and associated loss of high-ablating, low-elevation areas. However, once higher elevations have thinned substantially, the glacier can no longer counteract accelerated thinning by retreat and mass loss accelerates, even under constant climate conditions. We find that it would take a substantial cooling of 1.5°C to reverse the ongoing retreat. It is therefore likely that Yakutat Glacier will continue its retreat at an accelerating rate and disappear entirely.
In indirect-drive inertial confinement fusion, the radiation symmetry must be controlled for the achievement of hotspot ignition. The radiation symmetry is of great importance. In this paper, we investigate the drive asymmetry of the M-band (2–5 keV) radiation emitted from an Au holhraum wall by using the three-dimensional view-factor code IRAD3D. Analysis of the M-band flux drive at the Shenguang-III laser facility shows that it is asymmetric and that the asymmetry varies with time. For a given cross section over the pole, the initial M-band flux asymmetries are P2 = 11.59, P4 = 1.41, and P6 = −0.64%. When the asymmetries are artificially added to a symmetric radiation drive, the position of the deuterium-tritium (DT) ice/gas interface is asymmetric for a National Ignition Facility capsule in 1D simulation. This means that M-band flux asymmetry can lead to implosion asymmetry even if the total radiation is symmetric. Pure CH and Si-doped CH capsules are considered. The results show that a mid-Z dopant can partly reduce the asymmetry. However, the asymmetry is still very large. Thus, it is necessary to study the M-band flux asymmetry and its influence on the implosion symmetry.
We studied the evolution, genotypes, and the molecular clock of dengue virus serotype 1 (DENV-1), between 2001 and 2014 in Guangzhou, China. The analysis of the envelope (E) gene sequences of 67 DENV-1 strains isolated in Guangzhou, together with 58 representative sequences downloaded from NCBI, have shown shifts in viral genotypes. The genotype changed several times, from genotype I to IV in 2002, from IV to I in 2005, and from I to V in 2014. These genotype shifts may be the cause of DENV outbreaks. The diversity of genotypes and clades demonstrates a high risk of future outbreaks in Guangzhou. The mean rate of virus nucleotide substitution in Guangzhou was determined to be 7·77 × 10−4 per site per year, which represents a medium substitution rate compared to two other countries. Our research can point to different ancestors of the isolated strains, which may further reveal the different origins and transmission of DENV-1 strains in Guangzhou.
Dengue fever (DF) is the most prevalent and rapidly spreading mosquito-borne disease globally. Control of DF is limited by barriers to vector control and integrated management approaches. This study aimed to explore the potential risk factors for autochthonous DF transmission and to estimate the threshold effects of high-order interactions among risk factors. A time-series regression tree model was applied to estimate the hierarchical relationship between reported autochthonous DF cases and the potential risk factors including the timeliness of DF surveillance systems (median time interval between symptom onset date and diagnosis date, MTIOD), mosquito density, imported cases and meteorological factors in Zhongshan, China from 2001 to 2013. We found that MTIOD was the most influential factor in autochthonous DF transmission. Monthly autochthonous DF incidence rate increased by 36·02-fold [relative risk (RR) 36·02, 95% confidence interval (CI) 25·26–46·78, compared to the average DF incidence rate during the study period] when the 2-month lagged moving average of MTIOD was >4·15 days and the 3-month lagged moving average of the mean Breteau Index (BI) was ⩾16·57. If the 2-month lagged moving average MTIOD was between 1·11 and 4·15 days and the monthly maximum diurnal temperature range at a lag of 1 month was <9·6 °C, the monthly mean autochthonous DF incidence rate increased by 14·67-fold (RR 14·67, 95% CI 8·84–20·51, compared to the average DF incidence rate during the study period). This study demonstrates that the timeliness of DF surveillance systems, mosquito density and diurnal temperature range play critical roles in the autochthonous DF transmission in Zhongshan. Better assessment and prediction of the risk of DF transmission is beneficial for establishing scientific strategies for DF early warning surveillance and control.
We propose a Bayesian method to measure the total Galactic extinction parameters, RV and AV. Validation tests based on the simulated data indicate that the method can achieve the accuracy of around 0.01 mag. We apply this method to the SDSS BHB stars in the northern Galactic cap and find that the derived extinctions are highly consistent with those from Schlegel et al. (1998). It suggests that the Bayesian method is promising for the extinction estimation, even the reddening values are close to the observational errors.
Antibiotic resistance is a major risk to human health, and to provide valuable insights into mechanisms of resistance, innovative methods are needed to examine the cellular responses to antibiotic treatment. Focused ion beam tomography is proposed to image and assess the detailed three-dimensional (3D) ultrastructure of single bacterial cells. By iteratively removing slices of thickness in the order of 10 nm, high magnification 2D images can be acquired by scanning electron microscopy at single-digit nanometer resolution. In this study, Klebsiella pneumoniae was treated with polymyxin B, and 3D models of both cell envelope and cytoplasm regions containing the nucleoid and ribosomes were reconstructed. The 3D volume containing the nucleoid and ribosomes was significantly smaller, and the cell length along the longitudinal axis was extended by 40% in the treated cells, implying stress responses to the drug treatment. More than a 200% increase in protrusions per unit surface area on the cell envelope was observed in the curvature analysis after treatment. Experiments by conventional transmission electron microscopy and atomic force microscopy were also performed, followed by comparison and discussions. In conclusion, the proposed 3D imaging method and associated analysis provide a unique tool for the assessment of antibiotic effects on multidrug-resistant bacteria at nanometer resolution.
Morphology of the active layer in bulk heterojunction P3HT:PCBM organic solar cell was studied using Monte Carlo (MC) and coarse-grained dynamics simulations. While coarse-grained molecular dynamics allow us to quickly estimate the P3HT:PCBM interfacial energy of bilayer structure as a function of underlying layer thickness, bridging the dimension and time gap between dynamics simulations and experiment is computationally expensive and therefore not viable. Using MC technique with input from dynamics simulations allowed us to speed up the calculation and obtain final morphological information based on energetics and entropy, and at the same time retained the physics fidelity in-built in our validated coarse-grained model. The final structure gives phase separated domains with dimension of approximately 12 nm, on par with reported experimental result. The method can be applied to other organic photovoltaics systems to predict active layer morphology relevant for device performance or 3-dimensional device modelling at continuum level.
Compared with single markers, polygenic scores that evaluate the joint effects of multiple trait-associated variants are more effective in explaining the variance of traits and risk of diseases. In total, 182 CHDWB (Emory-Georgia Tech Center for Health Discovery and Well Being study) adults were genotyped to investigate the common variant contributions to three traits (height, BMI, serum triglycerides) and three diseases (coronary artery disease (CAD), type 2 diabetes (T2D) and asthma). Association was contrasted between weighted and simple allelic sum polygenic scores with quantitative traits, and with the Framingham risk scores for CAD and T2D. Although the cohort size is two or three orders of magnitude smaller than typical discovery cohorts, we were able to detect significant associations and to explain up to 5% of the traits by the genetic risk scores, despite a strong influence of outliers. An unexpected finding was that CAD-associated single nucleotide polymorphisms (SNPs) explain a significant amount of the variation for total serum cholesterol. Forward step-wise sequential addition of SNPs into the regression model showed that the top-ranked SNPs explain a large proportion of variance, whereas inclusion of gender and ethnicity also affect the performance of polygenic scores.
To investigate the feasibility of postauricular hypodermic injection for treating inner ear disorders, we compared perilymph pharmacokinetics for postauricular versus intravenous injection, using magnetic resonance imaging, in an animal model.
Twelve albino guinea pigs were divided randomly into two groups and administered gadopentetate dimeglumine via either a postauricular or an intravenous bolus injection. A 7.0 Tesla magnetic resonance imaging system was used to assess the signal intensities of gadolinium-enhanced images of the cochlea, as a biomarker for changes in gadopentetate dimeglumine concentration in the perilymph. Pharmacokinetic parameters were calculated based on these signal intensity values.
Guinea pigs receiving postauricular injection showed longer times to peak signal intensity, longer elimination half-life, longer mean residence time and a greater area under the signal–time curve (from pre-injection to the last time point) (p < 0.05).
Postauricular injection shows potential as an efficient drug delivery route for the treatment of inner ear disorders.
Successful control of wild oat in cereal crops requires an accurate prediction of the developmental stages of wild oat plants that emerged during the growing season. The main objective of this research was to evaluate wild oat growth and to predict the phyllochron of wild oat plants that emerge at various times in the Red River Valley region of Minnesota and North Dakota. Field experiments were conducted in 2002 and 2003 in Crookston, MN, and Fargo, ND. Four emergence cohorts were established in 4 successive wk. Research plots were arranged in randomized complete blocks with six replications. From the naturally emerged wild oat population, 10 randomly selected plants per plot were evaluated for plant height, leaves on main stem, tillers per plant, total leaves per plant, days to flag leaf emergence and to heading, biomass per plant, and seeds per plant. Haun's numerical cereal development scale was regressed on days after emergence (DAE), day length (DL), growing degree days (GDD), or photothermal units (PTU). Wild oats that emerged first required more time for flag leaf emergence and heading, were taller, and had more biomass, leaves, tillers, and seed production than wild oat plants that emerged later. Wild oat phyllochron intervals were 5.3 d, 94 GDD, or 1,468 PTU, regardless of emergence timing. These data suggest that wild oat phyllochron is primarily driven by air temperature and is relatively stable during the extended emergence period. Later-emerging wild oat plants, although not as competitive as earlier emerging ones, still have the potential to contribute to the seed bank if left uncontrolled.