Depressive symptoms, parenting attitude, and violent discipline among caregivers of left-behind children in rural China: a cross-sectional study.

BACKGROUND: The situation of mental health and discipline behaviors of left-behind children's caregivers were not optimistic in rural China. Caregivers' depression might increase the risk of using violent discipline. However, the specific ways in which depressive symptoms impact violent discipline have rarely been explored in rural areas. This study aims to assess the prevalence of violent discipline among left-behind children under 6 years of age in rural China and explore the potential mechanisms of how caregivers' depressive symptoms affect violent discipline. METHODS: We enrolled a total of 396 pairs of left-behind children and their caregivers in our study, which was conducted in 5 counties of Hebei, Henan, Jiangxi, Guizhou, and Sichuan provinces in China. The depressive symptoms of caregivers were measured by using Zung Self-rating Depression Scale (ZSDS) and violent discipline was assessed by the Child Discipline Module of Multiple Indicator Cluster Surveys (MICS). A self-designed questionnaire was utilized to measure caregiver's parenting attitude. Based on the cross-sectional data, controlling for potential confounders, structural equation modeling (SEM) was used to assess the direct and indirect effects of the mediation models by applying the weighted least squares with mean and variance adjusted (WLSMV) estimate. RESULTS: The prevalence of violent discipline, psychological aggression, and physical punishment was 72.7%, 59.3%, and 60.4% respectively of left-behind children under 6 years of age. According to the results of SEM, parenting attitude acted as a suppressor, suppressing the association between caregivers' depressive symptoms and physical punishment/psychological aggression/violent discipline. The caregivers' depressive symptoms positively influenced all the outcome variables by affecting parenting attitudes (p = 0.002, p = 0.013, p = 0.002). CONCLUSIONS: The presence of depressive symptoms in caregivers increases the use of violent discipline through negative parenting attitudes. The mental health status of primary caregivers of left-behind children in rural China needed emphasis and improvement.

Airborne magnetite nanoparticles induced early vascular pathologies by disrupting lipid metabolism under high-fat dietary patterns.

Magnetite nanoparticles (MNPs) have been extensively detected in the atmospheric environment and implicated as a prominent threat to atherosclerosis, a chronic vascular inflammatory disease. Due to globalization and economic development, the dramatic shift in diet from traditional to high-fat dietary patterns aggravated atherosclerosis progression induced by environmental factors. However, limited knowledge is available regarding vascular risks and underlying mechanisms of airborne MNPs in high-risk populations with high-fat dietary habits. Herein, we demonstrated that MNPs exerted a proatherogenic effect under high-fat dietary patterns, leading to aortic wall thickening, elastic fiber disorganization, macrophage infiltration, and local inflammation. Based on the correlation analysis between MNPs and PM group, we identified that MNPs might be a key PM component in atherogenic toxicity. MNPs exposure disturbed the dynamic process of lipid metabolism, manifested as aortic lipid accumulation, dyslipidemia, and hepatic lipid metabolism disorder, which was modulated by the JAK-STAT pathway. Overall, these findings provide new insight into understanding the cardiovascular risks and mechanisms of MNPs among high-risk populations.

Family responsive care mediating the home visiting effects on left-behind children's early development in rural China.

BACKGROUND: The early development of left-behind children requires great concern and improvement. Yet, current interventions for left-behind children are mainly focussed on children older than 3. This study aims to assess the effectiveness of a home visiting programme on family responsive care and early development of rural left-behind children and examine whether family responsive care mediates the effects of intervention on child development. METHODS: A quasi-experimental study design was utilized in this study. A stratified clustered sampling was employed to choose villages in programme towns into intervention group. A control village was matched with every intervention village. All of the left-behind children and their caregivers meeting the inclusion criteria in the chosen villages were enrolled in the survey. The outcomes included child development, caregiver's early stimulation, parent-child communication, and learning materials. Baseline assessments were conducted in 2018, and endline assessments were conducted in 2020. RESULTS: In the endline survey, we enrolled 608 children with 258 in the intervention group and 350 in the control group. Left-behind children in the intervention group were less likely to have development delay compared with the control group (odds ratio [OR] = 0.59, 95% confidence interval [CI]: 0.36, 0.96). Migrant parents of children in the intervention group showed higher proportion of expressing emotional support to their children when communicating (OR = 1.69, 95% CI: 1.05, 2.72). Children who received home visits more than once per 2 months had lower level of suspected development delay than children in the control group (OR = 0.34, 95% CI: 0.18, 0.68). Caregiver's early stimulation and migrant parents' emotional support to left-behind children mediated the intervention dose and left-behind children's development. CONCLUSION: Caregiver's early stimulation mediates the intervention and child's development. The findings suggest a promising future for scaling similar early childhood development interventions for left-behind children in rural settings.

High-Precision Positioning Stage Control Based on a Modified Disturbance Observer.

High-precision positioning systems play a crucial role in various industrial applications. This study focuses on improving the performance of a high-precision multi-degrees-of-freedom (DOF) stage. In terms of the controller design, the following two key challenges must be addressed: the cross-decoupling of different DOFs and the impact of external disturbances. To address these problems, a self-tuning approach is proposed for simultaneous decoupling and disturbance suppression. Initially, the stage undergoes static decoupling using a data-based approach, facilitating feedback control for each DOF through single-input, single-output controllers. Addressing dynamic coupling and external disturbance challenges, we introduced a comprehensive evaluation index and a self-tuning multi-input, multi-output disturbance observer. This approach enabled the evaluation and optimization of the disturbance compensation for all DOFs, ensuring optimal positioning accuracy. Finally, we tested the proposed method using a high-precision multi-DOF stage with a real-time control platform. The results demonstrated a significant reduction in the standard deviations of positioning errors in the rx, ry, and z directions by 46%, 58%, and 6%, respectively. The approach used in this study opens avenues for advancements in the design and control of complex multi-DOF systems.

Parental Migration Trajectories From Childhood Through Adolescence: Longitudinal Impact on Emotional and Behavioral Problems Among Chinese Adolescents.

It is estimated that there are about 23% of all children in China experiencing parental migration and being left behind at hometown. Existing research indicated a significant association between parental migration and children development but overlooked the dynamic changes in family structure caused by parental migration. In this study, data was derived from a nationally representative longitudinal survey-the China Family Panel Studies. The main analyses employed four waves of data (2012, 2014, 2016, and 2018) and included 1401 adolescents aged 10-15 years (Mean:12.35, SD:1.67; 54.2% female). Six typical trajectories of parental migration capturing both migration status at each timepoint and changes in the status across six years were created. Children's depression and internalizing problems and externalizing problems were concerned outcomes. The mediating roles of the caregiver-child interaction and caregiver's depression were examined. Adolescents in the trajectory group described as experiencing transitions between being left behind by both parents and non had a higher risk of depression and internalizing and externalizing problems. Caregivers' depression was a significant mediator between parental migration and adolescent depression.

Exogenous Chemical Exposure Increased Transcription Levels of the Host Virus Receptor Involving Coronavirus Infection.

Virus receptors are highly involved in mediating the entrance of infectious viruses into host cells. Here, we found that typical chemical exposure caused the upregulation of virus receptor mRNA levels. Chemicals with the same structural characteristics can affect the transcription of angiotensin-converting enzyme 2 (ACE2), a dominant receptor of SARS-CoV-2. Some chemicals can also regulate the transcription of ACE2 by similar regulatory mechanisms, such as multilayer biological responses and the crucial role of TATA-box binding protein associated factor 6. The abovementioned finding suggested that chemical mixtures may have a joint effect on the ACE2 mRNA level in the real scenario, where humans are exposed to numerous chemicals simultaneously in daily life. Chemically regulated virus receptor transcription was in a tissue-dependent manner, with the highest sensitivity in pulmonary epithelial cells. Therefore, in addition to genetic factors, exogenous chemical exposure can be an emerging nongenetic factor that stimulates the transcription of virus receptor abundance and may elevate the protein expression. These alterations could ultimately give rise to the susceptibility to virus infection and disease severity. This finding highlights new requirements for sufficient epidemiological data about exposomes on pathogen receptors in the host.

Investigating resistance levels to cyhalofop-butyl and mechanisms involved in Chinese sprangletop (Leptochloa chinensis L.) from Anhui Province, China.

Chinese sprangletop (Leptochloa chinensis (L.) Nees) is a common grass species that severely threatens rice (Oryza sativa L.) cropping systems globally. Cyhalofop-butyl is a highly efficient acetyl-CoA carboxylase (ACCase)-inhibiting herbicide widely used for control of this species in China. However, some L. chinensis populations have gradually evolved resistance to this herbicide in recent years. To better understand the cyhalofop-butyl resistance status of L. chinensis in the major rice planting area of the middle-lower Yangtze River basin, 73 populations collected from the rice fields across Anhui Province were investigated for cyhalofop-butyl susceptibility and potential herbicide resistance-conferring mutations. Single-dose testing indicated that of the 73 populations, 25 had evolved resistance to cyhalofop-butyl and were separately classified as "RRR" and "RR" populations according to their fresh weight reductions, 8 had a high risk of evolving cyhalofop-butyl resistance and were classified as "R?" populations, and 40 were susceptible and classified as "S" populations. Whole-plant dose-response experiments showed that the resistance index (RI) of these R?, RR, and RRR populations to cyhalofop-butyl ranged from 2.47 to 36.94. Target gene sequencing identified seven ACCase resistance mutations (I1781L, W1999C, W2027S, W2027L, W2027C, I2041N, and D2078G), with W1999C and W2027C the two most common detected in about three quarters of all the resistant populations. Seven populations including LASC3, BBHY1, AQQS1, HFFD3, HFFD4, AQWJ1, and HFLJ6 each carrying a specific ACCase mutation were tested for their cross- and multiple-resistance patterns. Compared with a standard susceptible population HFLY1, the seven resistant populations showed distinct cross-resistance. All had low- to high-level cross-resistance to metamifop (RIs ranging from 6.16 to 17.65), fenoxaprop-P-ethyl (RIs ranging from 6.39 to 24.08), and quizalofop-P-ethyl (RIs ranging from 2.20 to 10.25), but responded differently to clodinafop-propargyl and clethodim. Multiple-resistance testing suggested that the seven resistant populations were all susceptible to the 4-hydroxyphenylpyruvate dioxygenase inhibitor tripyrasulfone, the protoporphyrinogen oxidase inhibitor oxyfluorfen, and the auxin mimic herbicide florpyrauxifen. In conclusion, this study has shown that cyhalofop-butyl resistance was prevalent in L. chinensis in Anhui Province, China, and target site mutation was one of the most common resistance mechanisms.

Geometric layout optimization of a large aperture thin elliptical mirror's axial and lateral support.

For passive support of large aperture telescopes, geometric layout optimization of the support structure is one of the most critical tasks because it determines the deformation of the mirror under gravity, which affects the wavefront aberration and image quality of the system. Due to a lack of symmetry, the optimization of an elliptical mirror support can be much more complex compared with circular mirrors. We optimize the geometric layout of axial and lateral support for the tertiary mirror of the Thirty Meter Telescope (TMT). Based on a theoretical analysis of the whiffletree principle, a parametric model of axial support is established based on the multi-point constraint equation. The mirror deformation SlopeRMS of the tertiary mirror under vertical gravity is used as the optimization target of the support points. The axial support point position is optimized by means of a simulated annealing algorithm and a mirror-deformed post-processing script written in Python. The TMT tertiary mirror lateral support also uses the whiffletree structure, and its in-plane layout affects the system's resonant modal frequency and the maximum load at each point. According to the dynamic equation and the static principle, the lateral support optimization model is established. The first-order resonant frequency and maximum load of the support point are the objective function. Through optimization of the axial and lateral support, the overall mirror distortion of the system is improved.

Impact of parent-child separation on children's social-emotional development: a cross-sectional study of left-behind children in poor rural areas of China.

BACKGROUND: Parent-child separation is a considerable adversity for left-behind children (LBC), but there is little evidence on the association between detailed characteristics of parent-child separation and social-emotional development among LBC. This study examined the characteristics of parent-child separation and its impacts on developmental delay among under-3 LBC in poor rural China. METHODS: We used data from 811 LBC surveyed in five poor counties in rural China in 2018. Detailed characteristics of their parental migration were recalled by their primary caregivers in face-to-face interviews. The children's social-emotional development was measured by using the Ages and Stages Questionnaire: Social-Emotional. Logistic regression was employed to examine the association of detailed characteristics of parent-child separation with early social-emotional problems after adjusting for the children's and primary caregivers' sociodemographic characteristics. RESULTS: 287 (35.4%) children were left behind by fathers and cared for by mothers (FM-MC), while 524 (64.6%) were left behind by both parents and cared for by grandparents (PM-GC). The rate of social-emotional problems among LBC was 36.8% (PM-GC vs FM-MC: 40.6% vs 29.5%; aOR 1.51, 95% CI: 1.06 to 2.16). For paternal migration, the medians of the child's age at the first migration and average duration per migration were 3 months (IQR: 1 to 9 months) and 4.48 months (IQR: 2.38 to 7.54 months), respectively. For maternal migration, the corresponding values were 9 months (IQR: 6 to 13 months) and 4.65 months (IQR: 2.71 to 7.62 months), respectively. On average, LBC had been separated from fathers for 72% of their life due to paternal migration and from mothers for 52% of their life due to maternal migration. No significant association was found between the detailed characteristics of paternal migration and social-emotional development among LBC, while social-emotional problems among LBC were significantly associated with the proportion of cumulative duration of maternal migration in the child's lifetime (aOR 2.83; 95% CI: 1.13 to 7.10). CONCLUSIONS: LBC under 3 years had a high risk of social-emotional problems in poor rural China. Cumulative exposure to maternal migration may be detrimental to LBC's early social-emotional development. Programs are necessary to support these children as well as their families.

Relationships between dietary diversity and early childhood developmental outcomes in rural China.

The period from birth to 2years of age is highly sensitive with respect to the relationship between nutrition and neurodevelopment, but data regarding the association between dietary diversity and early childhood neurodevelopment are limited. We sought to examine the association of two feeding indicators-minimum dietary diversity (MDD) and minimum meal frequency (MMF)-with the neurodevelopment of children aged 6-23 months, using data from a cross-sectional survey conducted in six rural counties in China. Data on 1,534 children were analysed using logistic regression to explore the associations between dietary diversity and early neurodevelopment, with adjustments for the age, sex and prematurity of the child; the age, sex and educational level of the caregiver; and family size, income and simulative care practices and resources. We found that 32.4% of children had suspected developmental delays based on the Chinese version of the Ages and Stages Questionnaires Version 3, whereas 77.0% and 39.2% failed to meet the MDD and MMF, respectively. Meeting the MDD was associated with a 39% lower risk of developmental delays (AOR = 0.61, 95% CI [0.43, 0.86]). There was a significant association between MDD and reduced likelihood of developmental delays in gross motor, fine motor, problem-solving and personal social subscales, whereas MMF was only associated with a lower risk of developmental delays in the gross motor subscale (AOR = 0.63, 95% CI [0.42, 0.94]). We observed an inverse dose-response relationship between the number of food groups consumed and the risk of developmental delays (P < .001).

Large segmented sparse aperture collimation by curvature sensing.

Fine alignment of large, segmented telescopes is critical for achieving high angular resolution. Building an instrument with an equally large monolithic aperture is difficult because of the increasing mass and volume. Sparse aperture testing is a lower-cost solution to alignment and metrology, both in the optics shop and at the observatory. We combined sparse aperture testing and curvature sensing to process the highly segmented system's final alignment. First, the stitching error, including tip/tilt/piston and shifting errors, is analyzed theoretically and numerically. These errors are then evaluated by normalized point source sensitivity (PSSn), and the change of PSSn during alignment, which specifies the residual alignment error, is calculated by the defocused donuts. Simulations and experiments demonstrate that the system performance improved by more than 35%. In this paper, we have described the incorporation of sparse aperture testing and curvature sensing algorithms, which can easily cover the tipping and shifting error affecting the traditional methodology.

The association between parental migration and early childhood nutrition of left-behind children in rural China.

BACKGROUND: More than one-third of children under 3 years old are left behind at home due to parental migration in rural China, and we know very little about early childhood nutrition of left-behind children (LBC) because of the dearth of research. This study examined the association between parental migration and early childhood nutrition of LBC in rural China. METHODS: We used repeated cross-sectional data of rural children aged 6-35 months who participated in two surveys in six counties of northern and southern China in 2013 and 2016 respectively. The length, weight, and hemoglobin concentration were measured by trained health-care workers blinded to parental migration status. Stunting, underweight, wasting, and anemia were identified with the standards recommended by WHO. Generalized linear regressions and multivariate logistic regressions were employed to explore the association between parental migration and these nutritional outcomes at each time point. RESULTS: Two thousand three hundred thirty-six and 2210 children aged 6-35 months were enrolled in 2013 and 2016, respectively. The results show a reduction of the risks of stunting, underweight, and wasting from 2013 (16.4, 8.5, and 3.5%, respectively) to 2016 (12.1, 4.0, and 1.5%, respectively) but highlight a constantly and alarmingly high risk of anemia among these children (44.8% in 2013 and 43.8% in 2016). Children with migrant fathers performed as well as or better than those with non-migrants on these indicators. Children with migrant parents performed slightly worse in 2013, but equal or slightly superior in 2016 on these indicators compared with children with non-migrants and migrant fathers. Children aged 6-17 months with migrant parents had a significantly lower risk of anemia than those living with their mothers or with both parents (43.1% vs. 63.6% and 61.5 in 2013, and 42.5 vs. 60.1 and 66.2% in 2016), even after controlling for children's sociodemographic characteristics. CONCLUSIONS: Parental migration may be not detrimental and even beneficial to early childhood nutrition of LBC in rural China. Continued nutritional support is needed for all rural children, especially interventions for preventing micronutrient deficiency. Programs for LBC are recommended to continue to focus on nutrition but pay more attention to other important health issues.

The Effectiveness and Cost-effectiveness of a Parenting Intervention Integrated with Primary Health Care on Early Childhood Development: a Cluster-Randomized Controlled Trial.

Developing countries require interventions that can sustainably improve early childhood development (ECD) at scale because hundreds of millions of children are at risk of poor development. This study examined the effectiveness and cost-effectiveness of a parenting intervention integrated with primary health care in terms of ECD. A cluster-randomized controlled trial was conducted in 20 urban communities in China, with 82 and 86 children aged 1-2 months enrolled in the intervention and control groups, respectively, and 71 and 69 children, respectively, followed to 14 months of age. All children in both groups received routine primary health care services. Intervention caregivers received a parenting pamphlet and two parenting training sessions during well-child clinic visits; those with children with suspected developmental delay received additional parenting guidance by telephone. Compared with controls, children receiving the intervention had similar developmental outcomes, measured with the Chinese version of the Ages & Stages Questionnaires third edition (ASQ-C), at baseline, but had significantly higher communication (adjusted mean difference = 0.26; 95% CI 0.03, 0.51), fine motor (adjusted mean difference = 0.19; 95% CI 0.01, 0.37), and overall (adjusted mean difference = 0.25; 95% CI 0.10, 0.41) ASQ-C z-scores after 12 months of the intervention. The intervention cost per child was $50.87, and the costs for increasing the communication, fine motor, and overall ASQ-C scores by one SD were $195.65, $267.74, and $203.48, respectively. Our findings indicate that the integration of a parenting intervention with existing primary health care is a cost-effective way to improve ECD.

First Report of Leaf Spot Caused by Alternaria alternata on Sonchus asper in China.

Sonchus asper (Spiny sowthistle), belonging to the Asteraceae, is a problematic weed in grain crops, orchards as well as turf (Cho et al., 2019). In April 2016, about 90% of the S. asper plants infesting a pear orchard had symptomatic with black spots densely distributed on the leaves and stems in Da Yang Town, Luyang District, Hefei, Anhui (N31°55'43″, E117°11'40″). The foliar lesions were mostly circular (3.0 mm to 1.5 cm in diameter) or irregular in shape; lesions on the stem were elliptical to irregular in shape running along the vascular bundle and about 3 to 6mm long × 2 to 3mm wide. Severely affected plants had their leaves become completely blighted and eventually the plants died. Fifteen tissue pieces from five symptomatic leaves and stems were surface sterilized with 0.5% NaClO for two min, rinsed three times with sterile water, and then plated on 1/4-strength potato dextrose agar (PDA) medium. Fourteen fungal isolated were obtained from the tissues, the isolation frequency from the plant tissue pieces was almost 93%. Fungal colonies were circular, initially white, and eventually turned to dark olive or black along with profuse sporulation. The conidia were tawny to brownish green, obclavate to obpyriform, with a cylindrical or coniform short beak, ranging from 16.8 to 39.8 µm long × 6.3 to 14.7 µm wide with two to five transverse and zero to two longitudinal septa (n = 50) and were borne on branched conidiophores. These morphological characteristics were similar to those described for Alternaria alternata (Simmons, 2007). For one representative isolate, the internal transcribed spacer (ITS) region of rDNA, partial coding sequence of the actin (ACT) gene, partial Alt a 1 major allergen (ALT) gene and partial Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene were amplified and sequenced with primers ITS1/ITS4 (White et al., 1990), ACT512F/ACT783R (Carbone and Kohn, 1999), Alt-4for/Alt-4rev and gpd1/gpd2 (Lawrence et al., 2013) respectively. Sequences were submitted to GenBank (ITS: MH886523; ACT: MH892480; ALT: MN655781; GAPDH: MN655782). Based on a BLAST analysis, ITS, ACT gene and GAPDH gene had 100%-99.8% identity with the existing sequences of the ex-type CBS 916.96 of A. alternata (Fries) Keissler (ITS: AF347031; ACT: JQ671702; GAPDH: AY278808, respectively) and ALT gene showed 100% identity with the A. alternata isolate SCWC10 (MG199093). Thus the pathogen was identified as A. alternata based on its morphological and molecular characteristics. Pathogenicity tests were conducted on six to seven-leaf stage potted S. asper plants (one plant per pot). Five mm diameter fungal disks, which were excised from the edge of a three-day old A. alternata colony, were placed on healthy leaves of five plants. Same size sterile PDA disks were used as controls. In addition, a conidial suspension (107 conidia/ml) was also inoculated on healthy leaves of five plants, sterile distilled water was used as control. Both inoculation experiments were conducted in the greenhouse at 25 ± 2°C, 90 % relative humidity, 12 h light/dark photoperiod and repeated at least three times. Lesions were observed on all the leaves within 12 h after fungal disk inoculation. All pathogen inoculated plants developed lesions, similar to those observed on the symptomatic leaves in the field 12 days after conidial inoculation. No symptoms were observed on both control treatments. A. alternata was re-isolated from the inoculated leaves and confirmed by both morphological and molecular techniques, confirming Koch's postulates. To our knowledge, this is the first report of A. alternata causing leaf spot on S. asper in China. The pathogen could cause severe disease in S. asper, and has the potential to be further studied as a fungal weed biocontrol.

Feral rice from introgression of weedy rice genes into transgenic herbicide-resistant hybrid-rice progeny.

Pollen-mediated transgenic flow of herbicide resistance occurs bidirectionally between transgenic cultivated rice and weedy rice. The potential risk of weedy traits introgressing into hybrid rice has been underestimated and is poorly understood. In this study, two glufosinate-resistant transgenic rice varieties, hybrid rice (F1), and their succeeding generations (F2-F4) were planted for 3 years in field plots free of weedy rice adjacent to experimental weedy-rice fields. Weedy-rice-like (feral) plants that were both glufosinate-resistant and had red-pericarp seed were initially found only among the F3 generations of the two glufosinate-resistant transgenic hybrid cultivars. The composite fitness (an index based on eight productivity and weediness traits) of the feral progeny was significantly higher than that of the glufosinate-resistant transgenic hybrid (the original female parent of the feral progeny) under monoculture common garden conditions. The hybrid rice progeny segregated into individuals of variable height and extended flowering. The hybrid rice F2 generations had higher outcrossing rates by pollen reception (0.96-1.65%) than their progenitors (0.07-0.98%). The results show that herbicide-resistant weedy rice can rapidly arise by pollen-mediated gene flow from weedy to transgenic hybrid rice, and their segregating pollen-receptive progeny pose a greater agro-ecological risk than transgenic varieties. The safety assessment and management regulations for transgenic hybrid rice should take into account the risk of bidirectional gene flow.

Using structural equation modelling to assess factors influencing children's growth and nutrition in rural China.

OBJECTIVE: Children's poor growth and nutrition status has serious consequences and therefore it is important to understand its contributing factors. DESIGN: A community-based interventional study focusing on child feeding was conducted in a rural community in China. Data from the intervention group at baseline (1-4 months of age) and follow-up visits (12 and 18 months of age) were used in the present study (n 236). A structural equation model was generated to explore the effects of family wealth, household food safety, dietary intake, diseases and other factors on the growth and nutrition of young children. RESULTS: Mother's knowledge and behaviours on household food safety had positive effects on children's weight-for-age Z-score (WAZ; ß direct=0·03 and 0·15, respectively, at 12 months of age; ß direct=0·02 and 0·08, respectively, at 18 months; P<0·05) and weight-for-length Z-score (WLZ; ß direct=0·04 and 0·21, respectively, at 12 months of age; ß direct=0·01 and 0·06, respectively, at 18 months; P<0·05). While mothers' feeding behaviours and children's dietary intake at 12 months of age were positively associated with WAZ and/or WLZ at current and later ages, children's diseases were negatively associated with WAZ and WLZ cross-sectionally. CONCLUSIONS: Caregiver's knowledge and feeding behaviours, and children's dietary intake and diseases, are factors influencing the WAZ and WLZ of children. Promoting feeding and health knowledge and behaviours at early stages of childhood can improve children's physical growth at later ages.

Ritchey-Common sparse-aperture testing of the Giant Steerable Science Mirror.

The Giant Steerable Science Mirror (GSSM) is the tertiary mirror of the future large telescope, the Thirty Meter Telescope. However, the mirror is too large to be tested using only one aperture, and using many apertures will increase the cost of testing. To accomplish testing at a low cost, the number of apertures should be reduced. The Ritchey-Common (R-C) testing method, commonly used for testing large flat surfaces, uses only a reference spherical mirror and avoids the use of large planar interferometers. Additionally, only the low-spatial-frequency mirror figure is relevant in the system assembly and alignment. Hence, the applicability of sparse-aperture testing is investigated in this paper. Sparse-aperture testing and the R-C method were combined to lower the cost. Using this method and the normalized point source sensitivity (PSSn), the mirror figure can be specified in a simple and accurate manner. Moreover, as fewer subapertures are under test, the efficiency can be improved. An error analysis is conducted, focusing on the shifting error, irregularity error, tipping error, tangential/sagittal error, and seeing. For the testing of the GSSM prototype, the error analysis showed the total error in PSSn is 0.9701.

Low-order aberration correction of the TMT tertiary mirror prototype based on a warping harness.

A warping harness is proposed to simply and efficiently correct low-order aberrations that occur during manufacturing and operation of a telescope. For the Thirty Meter Telescope (TMT) tertiary mirror, the issue to be solved by the warping harness is particularly challenging due to its complicated load conditions and limited mounting space. In this study, first, a new type of whiffletree-based warping harness configuration applied to a »-prototype TMT tertiary mirror is presented and optimized using finite element analysis (FEA) to improve the output precision of the moment actuator. Next, based on the new configuration, a simulation method for a correction process is proposed. The results show that the root mean square value of the mirror-surface error converged from 64.9 to 25.4 nm after correction, which satisfied the requirement document of TMT. Finally, combined with the analysis and calculation results, the moment actuator testing system with high-precision displacement-force-strain is established to assess the system errors. The tests of the moment actuator displacement, stress, strain-output precision, linearity, and repeatability are completed, and all errors were found to be within a controllable range. The results show the validity and feasibility of the designed warping harness, which can prove its applicability in more complicated conditions and, to a certain degree, broaden the application scope of the warping harness.

Analysis and correction for measurement error of edge sensors caused by deformation of guide flexure applied in the Thirty Meter Telescope SSA.

The Thirty Meter Telescope (TMT) project will design and build a 30-m-diameter telescope for research in astronomy in visible and infrared wavelengths. The primary mirror of TMT is made up of 492 hexagonal mirror segments under active control. The highly segmented primary mirror will utilize edge sensors to align and stabilize the relative piston, tip, and tilt degrees of segments. The support system assembly (SSA) of the segmented mirror utilizes a guide flexure to decouple the axial support and lateral support, while its deformation will cause measurement error of the edge sensor. We have analyzed the theoretical relationship between the segment movement and the measurement value of the edge sensor. Further, we have proposed an error correction method with a matrix. The correction process and the simulation results of the edge sensor will be described in this paper.

CAREGIVER'S DEPRESSIVE SYMPTOMS AND YOUNG CHILDREN'S SOCIOEMOTIONAL DEVELOPMENT DELAYS: A CROSS-SECTIONAL STUDY IN POOR RURAL AREAS OF CHINA.

Poverty and its associated factors put people at risk for depression. The aims of this study were to describe the prevalence of depressive symptoms (DS) of primary caregivers and socioemotional development (SED) delays of young children in poor rural areas of China, and to explore the association between them. Cross-sectional data of 2,664 children aged 3 to 35 months and their primary caregivers were used for analysis. Characteristics of the child, caregiver, and family were collected through face-to-face caregiver interviews. DS were assessed by the Zung Self-Rating Depression Scale (W.W. Zung, 1965, as cited in World Health Organization, ), and SED was evaluated by the Ages and Stage Questionnaires: Social-Emotional (J. Squires, D. Bricker, & L. Potter, 1997). The χ2 test, stratification analysis, and logistic regression analyses were used to explore the association. Among the caregivers, 40.3% (95% confidence interval [CI] [38.4, 42.1]), reported DS. Caregivers who were male, older and ethnic minorities as well as had a low level of education, a low family income, or more children were more likely to have DS. Of the children, 24.4% (95% CI [22.8, 26.0]) were recognized with SED delays. Older children displayed more delays than did younger children, but no significant differences between males and females were found. SED delays were significantly associated with mother outmigrating, male caregivers, older age, ethnic minorities, and low education or families with a single parent, low-income, and having more children. Caregivers having DS, odds ratio (OR) = 2.40, 95% CI [1.99, 2.88], was a significant predictor of increased odds of SED delays; other factors were single-parent family, OR = 1.99, 95% CI [1.37, 2.89], inadequate care, OR = 1.69, 95% CI [1.30, 2.21], physical punishment, OR = 1.61, 95% CI [1.33, 1.95], ethnic minorities, OR = 1.41, 95% CI [1.17, 1.71], and child age in months, OR = 1.03, 95% CI [1.02, 1.04], according to the logistic regression analysis. DS are prevalent among caregivers with young children in poor rural areas. Interventions to improve the mental health of caregivers and their parenting behaviors are needed to improve children's SED.