Construction and validation of a musculoskeletal disease risk prediction model for underground coal miners

ObjectiveTo understand the prevalence among underground coal miners of musculoskeletal disorders (MSDs), analyze the risk factors affecting MSDs, and develop and validate a risk prediction model for the development of MSDs.Materials and methodsMSD questionnaires were used to investigate the prevalence of work-related musculoskeletal disorders among 860 underground coal miners in Xinjiang. The Chinese versions of the Effort-Reward Imbalance Questionnaire (ERI), the Burnout Scale (MBI), and the Self-Rating Depression Inventory (SDS) were used to investigate the occupational mental health status of underground coal miners. The R4.1.3 software cart installation package was applied to randomly divide the study subjects into a 1:1 training set and validation set, screen independent predictors using single- and multi-factor regression analysis, and draw personalized nomogram graph prediction models based on regression coefficients. Subject work characteristic (ROC) curves, calibration (Calibrate) curves, and decision curves (DCA) were used to analyze the predictive value of each variable on MSDs and the net benefit.Results(1) The prevalence of MSDs was 55.3%, 51.2%, and 41.9% since joining the workforce, in the past year, and in the past week, respectively; the highest prevalence was in the lower back (45.8% vs. 38.8% vs. 33.7%) and the lowest prevalence was in the hips and buttocks (13.3% vs. 11.4% vs. 9.1%) under different periods. (2) Underground coal miners: the mean total scores of occupational stress, burnout, and depression were 1.55 ± 0.64, 51.52 ± 11.53, and 13.83 ± 14.27, respectively. (3) Univariate regression revealed a higher prevalence of MSDs in those older than 45 years (49.5%), length of service > 15 years (56.4%), annual income <$60,000 (79.1$60,000 (OR = 1.742, 95% CI: 1.100–2.759), and severe burnout (OR = 0.284, 95% CI: 0.109–0.739), and that these were independent predictors of the occurrence of MSDs among workers in underground coal mine operations (p <  0.05). (5) The areas under the ROC curve for the training and validation sets were 0.665 (95% CI: 0.615–0.716) and 0.630 (95% CI: 0.578–0.682), respectively, indicating that the model has good predictive ability; the calibration plots showed good agreement between the predicted and actual prevalence of the model; and the DCA curves suggested that the predictive value of this nomogram model for MSDs was good.ConclusionThe prevalence of MSDs among workers working underground in coal mines was high, and the constructed nomogram showed good discriminatory ability and optimal accuracy

Generation of tumor-initiating cells by exogenous delivery of OCT4 transcription factor

Abstract Introduction Tumor-initiating cells (TIC) are being extensively studied for their role in tumor etiology, maintenance and resistance to treatment. The isolation of TICs has been limited by the scarcity of this population in the tissue of origin and because the molecular signatures that characterize these cells are not well understood. Herein, we describe the generation of TIC-like cell lines by ectopic expression of the OCT4 transcription factor (TF) in primary breast cell preparations. Methods OCT4 cDNA was over-expressed in four different primary human mammary epithelial (HMEC) breast cell preparations from reduction mammoplasty donors. OCT4-transduced breast cells (OTBCs) generated colonies (frequency ~0.01%) in self-renewal conditions (feeder cultures in human embryonic stem cell media). Differentiation assays, immunofluorescence, immunohistochemistry, and flow cytometry were performed to investigate the cell of origin of OTBCs. Serial dilutions of OTBCs were injected in nude mice to address their tumorigenic capabilities. Gene expression microarrays were performed in OTBCs, and the role of downstream targets of OCT4 in maintaining self-renewal was investigated by knock-down experiments. Results OTBCs overcame senescence, overexpressed telomerase, and down-regulated p16INK4A . In differentiation conditions, OTBCs generated populations of both myoepithelial and luminal cells at low frequency, suggesting that the cell of origin of some OTBCs was a bi-potent stem cell. Injection of OTBCs in nude mice generated poorly differentiated breast carcinomas with colonization capabilities. Gene expression microarrays of OTBC lines revealed a gene signature that was over-represented in the claudin-low molecular subtype of breast cancer. Lastly, siRNA-mediated knockdown of OCT4 or downstream embryonic targets of OCT4, such as NANOG and ZIC1, suppressed the ability of OTBCs to self-renew. Conclusions Transduction of OCT4 in normal breast preparations led to the generation of cell lines possessing tumor-initiating and colonization capabilities. These cells developed high-grade, poorly differentiated breast carcinomas in nude mice. Genome-wide analysis of OTBCs outlined an embryonic TF circuitry that could be operative in TICs, resulting in up-regulation of oncogenes and loss of tumor suppressive functions. These OTBCs represent a patient-specific model system for the discovery of novel oncogenic targets in claudin-low tumors

Analysis and shifting of stochastically stable equilibria for evolutionary snowdrift games

In this paper we investigate the stochastic stability of evolutionary snowdrift games, which belong to a class of standard games popular in theoretical biology for the study of the mechanism of the emergence and maintenance of cooperation in large populations of strategically interacting individuals. We identify stochastically stable equilibria for two-player and multi-player evolutionary snowdrift games, for which the existing results are almost exclusively on the former. For the two cases with the same values of cost and benefit of cooperation, we show that like the two-player case, under certain conditions, there is a unique stochastically stable equilibrium in the multi-player case, at which, however, the proportion of cooperators can be higher than that of the two-player case. More importantly, the proportion cooperators can be manipulated as the stochastically stable equilibrium is being shifted by changing the game parameters. So the results indicate a promising approach to controlling the proportion cooperators in large populations that has not been reported before. Besides theoretical analysis, we demonstrate our results through numerical computations and simulations as well. (C) 2015 Elsevier B.V. All rights reserved

Characteristics and Environmental Factors of Stoichiometric Homeostasis of Soil Microbial Biomass Carbon, Nitrogen and Phosphorus in China

Marine studies have shown that the carbon:nitrogen:phosphorus (C:N:P) atomic ratio in planktonic organisms is generally 106:16:1, which is known as the “Redfield ratio„. This raises the question of whether there are similar patterns in terrestrial organisms, particularly in soil. In this study, we extracted 404 datasets from the literature to analyze the ecological stoichiometry of C, N and P, both in the soil and in the soil microbial biomass in China; additionally, we assessed their relationships with environmental factors, and calculated the homeostasis coefficient (H) of soil microbial biomass. First, although the concentrations of C, N and P in soil and soil microbial biomass showed high spatial heterogeneity, the atomic C:N:P ratios in the soil and soil microbial biomass were relatively consistent at the national scale. Second, the influences of temperature and precipitation on stoichiometric relationships among C, N and P in the soil and soil microbial biomass were limited in China; however, they decreased with the increase in soil pH. Third, the degree of stoichiometric homeostasis for soil microbes spanned a wide range, from non-homeostasis to strict homeostasis. For single elements, most of the soil microbes’ H ranged from 1.01 to 5.00; for elemental ratios, most of the soil microbes’ H displayed strict homeostasis. This study indicates that the “Redfield-like„ ratio exists in the soil microbial biomass in the 0–20 cm soil layer in China, with an atomic C:N:P ratio of 66:8:1 and it is close to the atomic C:N:P ratio in the soil (66:5:1) of terrestrial ecosystems. In addition to the N:P ratio in plants, the soil microbial biomass N:P ratio may also be used to judge the nutrient limitations because of its high stability

The practice of “Task-driven Small-step Fast-forward Teaching Method” in Computer Course

Due to many factors, the quality of students in higher vocational colleges has fall-en sharply. It’s a question worth studying to get more students to listen, study, understand and learn in class. The traditional "task-driven teaching method" can-not fully adapt to the present higher vocational classroom teaching. This paper in-troduces the "task-driven small-step fast-forward teaching method" to improve the traditional "task-driven teaching method," and verifies with two courses in practice

The practice of “Task-driven Small-step Fast-forward Teaching Method” in Computer Course

Due to many factors, the quality of students in higher vocational colleges has fall-en sharply. It’s a question worth studying to get more students to listen, study, understand and learn in class. The traditional "task-driven teaching method" can-not fully adapt to the present higher vocational classroom teaching. This paper in-troduces the "task-driven small-step fast-forward teaching method" to improve the traditional "task-driven teaching method," and verifies with two courses in practice

A comparative study of online communities and popularity of BBS in four Chinese universities.

Online forums in Chinese universities play an important role in understanding collective behavior of college students. Of particular interest are community and popularity. We address these two issues by examining data from Bulletin Board Systems (BBSs) of four Chinese universities. To characterize users' behavior, we introduce a hypothesis test to infer individual preferred boards, which yields a polarization of users. We also perform a multilevel algorithm to detect communities of each BBS network. We measure the similarity between the board-preferred polarization and the algorithmically identified community structure by quantitative and visual tools. The resulting discrepancy indicates that board labels are inadequate to represent underlying communities. To reveal online popularity, we employ latent Dirichlet allocation to mine topics from threads to compare popularity in different universities. Based on which, we implement the Cox-Stuart test to explore the change in popularity over time and reproduce significantly ascending and descending topics around a decade. Finally, we devise a two-step model based on users' preference and interests to reproduce the observed connectivity patterns

Simple and Sensitive Discrimination of Amino Acids with Functionalized Silver Nanoparticles

A chemiluminescence (CL) sensing method for amino acid discrimination based on luminol functionalized silver nanoparticles (LumAgNPs) has been developed. Luminescence emission in the presence of hydrogen peroxide under neutral conditions was characterized in three ways: the time required for the signal to appear (<i>T</i>_a), the time required to reach maximum luminescence (<i>T</i>_p), and CL intensity. These factors were found to change upon interaction of the nanoparticles with various amino acids, leading to distinct response patterns characteristic of each analyte. Seven amino acids (l-cysteine, l-proline, l-phenylalanine, l-arginine, l-threonine, l-glutamic acid, and l-tyrosine) were identified at a concentration of 10 ng/mL. This sensitivity is about 3 orders of magnitude better than that of recently reported methods based on fluorescent sensor arrays using cucurbit­[n]­uril and comparable to high-performance liquid chromatography. Application to 27 unknown samples gave a 96.3% success rate at the 10 ng/mL level

Absolute stabilization of Lur’e systems by periodically intermittent control

International audienceIn this paper, we design periodically intermittent feedback controllers for Lur'e systems to achieve absolute stabilization. More precisely, our designed periodically intermittent feedback controller is able to cope with any unknown Lur'e-type nonlinearity within a given sector. First, by means of global exponential Lyapunov stability, a set of sufficient stability conditions on the controlled Lur'e system is derived. Subsequently, we give the controller design algorithm in terms of the necessary and sufficient conditions to the stability criteria. By using the LMI Control Toolbox in Matlab, it is easy to compute the control parameters, including the feedback gain matrix, the control period and the control width, involved in the stability criteria. A numerical example considering a Chua's oscillator under periodically intermittent feedback control is presented to illustrate the validity of our obtained theoretical results. Finally, further discussions close the paper along with some possible interesting topics for future research