Prediction of photoperiodic regulators from quantitative gene circuit models

Photoperiod sensors allow physiological adaptation to the changing seasons. The external coincidence hypothesis postulates that a light-responsive regulator is modulated by a circadian rhythm. Sufficient data are available to test this quantitatively in plants, though not yet in animals. In Arabidopsis, the clock-regulated genes CONSTANS (CO) and FLAVIN, KELCH, F-BOX (FKF1) and their lightsensitive proteins are thought to form an external coincidence sensor. We use 40 timeseries of molecular data to model the integration of light and timing information by CO, its target gene FLOWERING LOCUS T (FT), and the circadian clock. Among other predictions, the models show that FKF1 activates FT. We demonstrate experimentally that this effect is independent of the known activation of CO by FKF1, thus we locate a major, novel controller of photoperiodism. External coincidence is part of a complex photoperiod sensor: modelling makes this complexity explicit and may thus contribute to crop improvement

Psychosocial factors associated with occupation: A comparative study between brick kiln and grocery workers

Background: Psychosocial factors, like physical, chemical and biological factors, are also the potential hazards. But, psychological factors, such as stress, are not mentioned in every kinds of occupation.  Some important psychosocial manifestations found among the workers in previous studies were headache, depression, frustration, worry, low self-esteem, boredom and lack of sleep. Objective: This study was carried out to evaluate and psychosocial factors that are associated with occupational factor between brick kiln workers and grocery workers. Methods: An analytical cross-sectional study was conducted in Kathmandu Valley during February-March 2015 i, targeting all the brick kiln workers. Firstly, all the registered the brick kilns (106 in number) were visited to form the potential sampling frame. Multi-stage probability proportionate to size sampling was applied to select 400 brick kiln workers from 16 brick kilns who had been working there for more than two years. An equal size unmatched reference group was maintained from the grocery workers. Interviews were conducted by trained health workers. Data was entered in the Microsoft (MS) excel and was transferred into the International Business Machines (IBM) Corporation. Statistical Package for the Social Sciences (SPSS) Statistics 21 was used to perform analysis. Both descriptive and (mean, median and inter-quartile range) and inferential (Mann Whitney U test) statistics were computed. The level of significance was set at <0.05. Results: Nearly 20.0% of exposed workers were <19 years of age among which slightly above three fifth achieved primary education. Almost 40% of brick kiln workers were ever smokers. Positive factors of psychosocial and emotional functioning were lower and negative factors were higher among brick kiln workers. The parameters of relationships such as self-esteem, stress and personal agency and the parameters of emotions like emotional, somatic, chronic fear, anxiety, hopelessness, helplessness, abuse and mal-treatment were better and significantly better respectively, in the reference group than the exposed group.  However, the social factor was significantly poor among the reference group i.e. the grocery workers as observed while conducting Mann Whitney U test at p<0.05 level. Conclusion: Among most of the parameters, brick kiln workers' psychosocial functioning was significantly poorer than the grocery workers. Providing formal and/or non-formal education as well as raising awareness about the deleterious effects of the exposure to brick kiln workers  should be recommended

Respiratory symptoms and illnesses related to the concentration of airborne particulate matter among brick kiln workers in Kathmandu valley, Nepal

Abstract Background Bricks have been manufactured in Nepal for hundreds of years and are seen as a component of Nepalese sculpture and architecture. Large quantities of hazardous materials including high concentrations of particulate matter are emitted on a daily basis from brick kilns. Exposure to these hazardous materials can lead to adverse consequences on the environment and human health. This study was conducted to  estimate the prevalence of respiratory symptoms/illnesses and the magnitude of respirable and total dust exposures among Nepalese brick kiln workers. Methods Respiratory symptoms/illnesses were evaluated by questionnaire among brickfield workers (n = 400) and a referent group of grocery workers (n = 400) in Kathmandu valley. Work zones (WZs): green brick molding (GBM), green brick stacking/carrying (GBS/C), red brick loading/carrying (RBL/C), coal preparation (CP) and firemen (FM) were the similar exposure groups (SEGs) from where personal air samples and interviews were taken. Among brickfield workers, personal monitoring was conducted across SEGs for total (n = 89) and respirable (n = 72) dust during February–March 2015 and March–April 2016. Applying multi-stage probability proportionate to size sampling technique, 16 kilns and 400 brick workers for interview were selected. Proportions, means, medians and ranges were calculated for the demographics, samples and respiratory symptoms/illnesses. One-way ANOVA was applied to compare the significance differences of the level of particulate matter among SEGs. Bivariate and multivariate logistic regression analysis were performed to evaluate association between respiratory symptoms/illnesses and participants groups, and SEGs among brick kiln workers at 0.05 level. Statistical analyses were performed using IBM SPSS Statistics 21. Results Chronic cough (14.3%), phlegm (16.6%) and bronchitis (19.0%) were higher (P < 0.05) among brickfield compared with grocery workers (6.8, 5.8 and 10.8%). Mean respirable (5.888 mg/m3) and total (20.657 mg/m3) dust exposures were highest for red brick loading tasks. The prevalence of chronic cough, chronic phlegm, chronic bronchitis, wheezing and asthma were significantly higher for other WZs workers (p < 0.05) compared with CP; for GBM: 22.9, 34.6, 15.0 and 7.5%; for GBS/C: 13.5, 15.8, 10.0, 8.8 and 7.5%; for RBL/C: 11.1, 17.1, 27.4, 19.0 and 11.9%; for FM: 18.4, 12.5, 28.4, 4.9 and 0.0%; and for CP: 4.9, 6.3, 13.3, 9.3 and 4.0% respectively. Conclusion High dust exposures identified in this study may explain the increased prevalence of respiratory symptoms/illnesses among Nepalese brickfield workers, warranting action to reduce exposures