Derived patterns of musculoskeletal symptoms and their relationships with ergonomic factors among electronic assembly workers: A latent class analysis.

INTRODUCTION: Multi-site musculoskeletal symptoms (MSS) are considered to be more common and have more serious consequences than single-site MSS. This study aimed to determine whether derived patterns of MSS may be identified in electronic assembly workers and if extracted MSS classes are associated with personal and work-related factors. METHOD: A cross-sectional questionnaire study was performed with 700 participating electronic assembly workers. The questionnaire included individual factors, psychosocial and physical exposures, and MSS. The derived patterns of MSS and their relationships with ergonomic factors were analyzed using latent class analysis (LCA) and multinomial logistic regression models (MLRM). RESULTS: The 1-year prevalence of MSS affecting only one body site or two or more body sites was 14.9% and 32.7%, respectively. The results of LCA showed three distinct classes of MSS patterns, which were labelled 'MSS in most sites' (5.0%), 'MSS in neck and shoulder' (27.0%), and 'MSS in one or no site' (68.0%). The results of MLRM showed that the 'MSS in neck and shoulder' was associated with job tenure (OR 5.579, 95% CI 2.488-12.511), excessive dynamic and static loads (OR 3.868, 95% CI 1.702-8.793 and OR 5.270, 95% CI 2.020-13.747, respectively); while the 'MSS in most sites' was associated with high job demands (OR 4.528, 95% CI 1.647-12.445) and excessive dynamic loads (OR 111.554, 95% CI 4.996-2490.793). CONCLUSIONS: The results showed unique patterns of MSS among electronic assembly workers that were associated with personal and work-related factors. PRACTICAL APPLICATIONS: The findings highlight that the high prevalence of multi-site MSS in this group should be a focus. It also provides further evidence that LCA considering the number and location of anatomical sites involving MSS can be used to determine distinct classes of MSS patterns, which is of great significance for the epidemiological study and management of MSS in the future.

The Intellectual Structure of Research on Rural-to-Urban Migrants: A Bibliometric Analysis.

As noted in the United Nations' Sustainable Development Goals 2030 agenda, sustainable cities "without leaving anyone behind" should take into consideration migrant groups, which may play only a marginal role but may be at the root of potential social conflicts. This study thereby promotes cross-disciplinary explorations of knowing and understanding the rural-to-urban internal migrants against the background of rapid urbanization. This study conducted a bibliometric analysis based on 2788 English language articles obtained from the Web of Science Core Collection database. As China's unique Hukou system highlights the divide between rural migrants and urban dwellers, migrant studies have extended to a diverse range of interests. We underlined the most productive sources and authors in this area and identified networks of collaboration among countries and institutions. Furthermore, we found trends in research themes and topics and research clusters through keyword-based analysis techniques. The results provide a rich source of information on the intellectual structure of the chosen domain of rural-to-urban migrants.

Learning From Errors: Exploring the Effectiveness of Enhanced Error Messages in Learning to Program.

Error messages provided by the programming environments are often cryptic and confusing to learners. This study explored the effectiveness of enhanced programming error messages (EPEMs) in a Python-based introductory programming course. Participants were two groups of middle school students. The control group only received raw programming error messages (RPEMs) and had 35 students. The treatment group received EPEMs and had 33 students. During the class, students used an automated assessment tool called Mulberry to practice their programming skill. Mulberry automatically collected all the solutions students submitted when solving programming problems. Data analysis was based on 6339 student solutions collected by Mulberry. Our results showed that EPEMs did not help to reduce student errors or improve students' performance in debugging. The ineffectiveness of EPEMs may result from reasons such as the inaccuracy of the interpreter's error messages or students not reading the EPEMs. However, the viewpoint of productive failure may provide a better explanation of the ineffectiveness of EPEMs. The failures in coding and difficulties in debugging can be resources for learning. We recommend that researchers reconsider the role of errors in code and investigate whether and how failures and debugging contribute to the learning of programming.

Study on the Associations of Individual and Work-Related Factors with Low Back Pain among Manufacturing Workers Based on Logistic Regression and Structural Equation Model.

Work-related musculoskeletal injuries are one of the major occupational health issues of the workers, especially low back pain (LBP). The aim of this study was to survey the prevalence of LBP among manufacturing workers and to identify associations of individual and work-related factors with LBP. A cross-sectional questionnaire study was performed with 1173 participating manufacturing workers. The questionnaire included individual factors, psychosocial and physical exposures, and musculoskeletal discomfort. It was analyzed by logistic regression and structural equation modeling (SEM). The 1-year prevalence of LBP among Chinese manufacturing workers was 33.6%. Logistic regression analysis showed that job tenure, awkward postures, vibration and job demand were positively-while social support and job control were negatively associated with LBP (p < 0.05). The SEM results indicated that, as shown in other studies, job types, job tenure, postural load, high job demand, low job control and vibration were directly associated with LBP, but also that job types, high job demand, low social support and vibration may have indirect effects on LBP-mediated by postural load.

Cervical musculoskeletal disorders and their relationships with personal and work-related factors among electronic assembly workers.

INTRODUCTION: Electronics assembly workers are reported to have a high prevalence of musculoskeletal disorders (MSDs). This study investigated the prevalence of cervical MSDs and the complex relationships between cervical MSDs and individual, physical, psychosocial factors among electronics assembly workers. METHODS: In this cross-sectional survey, self-administered questionnaires from 700 workers in electronics manufacturing workshops were analysed. Information concerning musculoskeletal symptoms, personal and work-related factors was collected. Finally, the prevalence of cervical MSDs was computed for different subgroups, and the relationships with different factors were analyzed using logistic regression and structural equation modeling (SEM). RESULTS: The total 12 month prevalence of cervical MSDs among the survey population was 29.4%. Variables of gender, job tenure, twisting head frequently, neck flexion/extension for long time and work required to be done quickly showed significant associations with MSDs in a multivariate logistic regression (P < 0.05). The SEM analysis showed moderate and significant correlations between postural load (γ = 0.279), gender (γ = 0.233) and cervical MSDs, while there were weak but significant correlations between vibration (γ = 0.024), work stress (γ = 0.126), job tenure (γ = 0.024) and cervical MSDs. Both work stress and vibration affected the MSDs indirectly through postural load. CONCLUSIONS: The logistic regression results support previous general epidemiological MSD studies, and indicates that individual, physical, and psychosocial factors are related to cervical MSDs. The SEM provides a better approximation of the complexity of the relationship between risk factors and cervical MSDs. Improving awkward postures may be effective ways to control the influence of occupational stressors or vibration on MSDs. Practical Applications: The study is to improve prevention of MSDs among electronics assembly workers and promote their occupational health.

Virus-Based MicroRNA Silencing and Overexpressing in Common Wheat (Triticum aestivum L.).

MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs that arise from large RNA precursors with a stem-loop structure and play important roles in plant development and responses to environmental stress. Although a hundred and nineteen wheat miRNAs have been identified and registered in the miRBase (Release 21.0, June, 2014; http://www.mirbase.org), the functional characterization of these miRNAs in wheat growth and development is lagging due to lack of effective techniques to investigate endogenous miRNA functions in wheat. Here we report barley stripe mosaic virus(BSMV)-based miRNA overexpression and silence systems that can be applied to study miRNA functions in wheat. By utilizing the BSMV system, we successfully knocked down endogenous miR156 and miR166 levels and over-expressed endogenous miR156 and artificial miRNA against phytoene desaturase gene PDS (amiR-PDS) in wheat. amiR-PDS expression caused a great reduction in endogenous mRNA abundance of PDS gene in wheat plant, leading to leaf obviously photobleaching. miR156 silencing led to a great increase in the mRNA level of its target gene SPL2, resulting in a leaf-curl phenotype in wheat seedlings. In contrast, overexpression of miR156 led to a significant reduction in the mRNA level of SPL2 in wheat seedlings, resulting in serious delay of the vegetative phase transitions as well as booting and flowering in wheat. These confirmed that miR156 regulates wheat development and booting time through SPL genes. In summary, the BSMV-based miRNA overexpression and silence systems have extraordinary potential not only for functional study of protein-encoding genes but also for miRNA genes in wheat.

Rice stripe virus affects the viability of its vector offspring by changing developmental gene expression in embryos.

Plant viruses may affect the viability and development process of their herbivore vectors. Small brown planthopper (SBPH) is main vector of Rice stripe virus (RSV), which causes serious rice stripe disease. Here, we reported the effects of RSV on SBPH offspring by crossing experiments between viruliferous and non-viruliferous strains. The life parameters of offspring from different cross combinations were compared. The hatchability of F1 progeny from viruliferous parents decreased significantly, and viruliferous rate was completely controlled by viruliferous maternal parent. To better elucidate the underlying biological mechanisms, the morphology of eggs, viral propagation and distribution in the eggs and expression profile of embryonic development genes were investigated. The results indicated that RSV replicated and accumulated in SBPH eggs resulting in developmental stunt or delay of partial eggs; in addition, RSV was only able to infect ovum but not sperm. According to the expression profile, expression of 13 developmental genes was regulated in the eggs from viruliferous parents, in which two important regulatory genes (Ls-Dorsal and Ls-CPO) were most significantly down-regulated. In general, RSV exerts an adverse effect on SBPH, which is unfavourable for the expansion of viruliferous populations. The viewpoint is also supported by systematic monitoring of SBPH viruliferous rate.

Bis(1,10-phenanthroline-κN,N')(sulfato-κO,O')cobalt(II) butane-2,3-diol monosolvate.

In the title compound, [Co(SO(4))(C(12)H(8)N(2))(2)]·C(4)H(10)O(2), the Co(2+) ion has a distorted octa-hedral coordination environment composed of four N atoms from two chelating 1,10-phenanthroline ligands and two O atoms from an O,O'-bidentate sulfate anion. The dihedral angle between the two chelating N(2)C(2) groups is 83.48 (1)°. The Co(2+) ion, the S atom and the mid-point of the central C-C bond of the butane-2,3-diol solvent mol-ecule are situated on twofold rotation axes. The mol-ecules of the complex and the solvent mol-ecules are held together by pairs of symmetry-related O-H⋯O hydrogen bonds with the uncoordinated O atoms of the sulfate ions as acceptors. The solvent mol-ecule is disordered over two sets of sites with site occupancies of 0.40 and 0.60.

[A study on endothelial function and inflammation factors in the first degree relatives of type 2 diabetics with normal glucose tolerance].

OBJECTIVE: To study the vascular endothelial function and the level of inflammation factors in the first degree relatives (FDR) of type 2 diabetes (T2DM) patients with normal glucose tolerance and related factors. METHODS: Vascular endothelial function, plasma plasminogen activator inhibitor-1 (PAI-1), vascular cell adhesion molecule-1 (VCAM-1) and insulin active index (IAI) were measured in 57 FDR and 31 controls. RESULTS: As compared with the controls, there were less endothelium-dependent vasodilation [(12.45 +/- 3.37)% vs (5.03 +/- 0.34)%] and IAI [(-3.79 +/- 0.57) vs (-4.11 +/- 0.46)], higher PAI-1 [(30.46 +/- 12.28) microg/L vs (39.25 +/- 6.54) microg/L] and higher VCAM-1 [(637.31 +/- 107.32) microg/L vs (742.39 +/- 124.31) microg/L] in the FDR (P < 0.05). CONCLUSION: There were decreased IAI, damaged endothelial function and impaired fibrinolysis in the first degree relatives of T2DM patients with normal glucose tolerance.