Prevalence of Depression in a Large Urban South Indian Population — The Chennai Urban Rural Epidemiology Study (Cures – 70)

BACKGROUND: In India there are very few population based data on prevalence of depression. The aim of the study was to determine the prevalence of depression in an urban south Indian population. METHODS AND FINDINGS: Subjects were recruited from the Chennai Urban Rural Epidemiology Study (CURES), involving 26,001 subjects randomly recruited from 46 of the 155 corporation wards of Chennai (formerly Madras) city in South India. 25,455 subjects participated in this study (response rate 97.9%). Depression was assessed using a self-reported and previously validated instrument, the Patient Health Questionnaire (PHQ) - 12. Age adjustment was made according to the 2001 census of India. The overall prevalence of depression was 15.1% (age-adjusted, 15.9%) and was higher in females (females 16.3% vs. males 13.9%, p<0.0001). The odds ratio (OR) for depression in female subjects was 1.20 [Confidence Intervals (CI): 1.12-1.28, p<0.001] compared to male subjects. Depressed mood was the most common symptom (30.8%), followed by tiredness (30.0%) while more severe symptoms such as suicidal thoughts (12.4%) and speech and motor retardation (12.4%) were less common. There was an increasing trend in the prevalence of depression with age among both female (p<0.001) and male subjects (p<0.001). The prevalence of depression was higher in the low income group (19.3%) compared to the higher income group (5.9%, p<0.001). Prevalence of depression was also higher among divorced (26.5%) and widowed (20%) compared to currently married subjects (15.4%, p<0.001). CONCLUSIONS: This is the largest population-based study from India to report on prevalence of depression and shows that among urban south Indians, the prevalence of depression was 15.1%. Age, female gender and lower socio-economic status are some of the factors associated with depression in this population

MULTI-OBJECTIVE OPTIMIZATION OF EDM PARAMETERS USING GREY RELATION ANALYSIS

This paper involves the multi-objective optimization of process parameters of AlSi10Mg/9 wt% alumina/3 wt% graphite in Electrical Discharge Machining for obtaining minimum surface roughness, minimum tool wear rate and maximum material removal rate. The important machining parameters were selected as peak current, flushing pressure and pulse-on time. Experiments were conducted by selecting different operating levels for the three parameters according to Taguchi’s Design of Experiments. The multi-objective optimization was performed using Grey Relation Analysis to determine the optimal solution. The Grey Relation Grade values were then analysed using Analysis of Variance to determine the most contributing input parameter. On analysis it was found that peak current, flushing pressure and pulse-on time had an influence of 61.36%, 17.81% and 8.09% respectively on the optimal solution

Impact of Annular Solar Eclipse on the Trace Gases and Dynamics of the Lower and Middle Atmosphere: Results Inferred From an Integrated Campaign “Suryagrahan‐2019”

Abstract An integrated campaign “Suryagrahan‐2019” with multi‐institutional support was conducted by launching a series of radiosondes/ozonesondes over 6‐different locations in India along with the operation of ST/MST radars and launching of RH‐200 rockets during the annular solar eclipse of 26 December 2019. We present the eclipse‐induced changes in the thermal structure, dynamics and trace gases in the lower and middle atmosphere. One of the novel findings is the formation of three step‐like isothermal structures in the lower stratosphere with a layer height of 1.4, 2.5, and 4 km, which is attributed to the adiabatic compression and expansion of the air parcel. These structures have both warming and cooling effect of the order of ±6 K. A significant increase of ozone by 20% in post‐eclipse scenario between 29 and 32 km is observed over Cochin. Strong downdrafts of ∼−0.25 m s−1 are observed between 12 and 16 km during the eclipse event, which is attributed to the atmospheric compression due to the sudden cooling during the eclipse event. Due to the changes in thermal structure, the atmospheric circulation changes are observed in the meridional wind. During the maximum obscuration, there is a sudden decrease in near‐surface and boundary layer ozone by 12–15 ppbv. The present study reiterates that the eclipse‐induced perturbations depend on the local time of the eclipse event and place of observations. It is envisaged that the results discussed in the study will improve our understanding of the eclipse induced perturbations in the Earth's atmosphere