Requirement for specific gravity and creatinine adjustments for urinary steroids and luteinizing hormone concentrations in adolescents

Objectives: Urinary hormone concentrations are often adjusted to correct for hydration status. We aimed to determine whether first morning void urine hormones in growing adolescents require adjustments and, if so, whether urinary creatinine or specific gravity (SG) are better adjustments. Design and Methods: The study population was adolescents aged 10.1 to 14.3 years initially who provided fasting morning blood samples at 0 and 12 months (n=343) and first morning urine every three months (n=644). Unadjusted, creatinine and SG-adjusted hormonal concentrations were compared by Deming regression and Bland-Altman analysis and grouped according to self-rated Tanner stage or chronological age. F-ratios for self-rated Tanner stages and age groups were used to compare unadjusted and adjusted hormonal changes in growing young adolescents. Correlations of paired serum and urinary hormonal concentration of unadjusted and creatinine and SG adjusted were also compared. Results: Fasting first morning void hormone concentrations correlated well and were unbiased between unadjusted or adjusted by either creatinine or SG. Urine creatinine concentration increases with Tanner stages, age and male gender whereas, urine SG was not influenced by Tanner stage, age or gender. Adjustment by creatinine or SG of urinary luteinizing hormone, estradiol, testosterone, dihydrotestosterone and dehydroepiandrosterone concentrations did not improve correlation with paired serum concentrations. Conclusions: Urine steroid and LH concentrations in first morning void samples of adolescents are not significantly influenced by hydration status and may not require adjustments; however, if desired, both creatinine and SG adjustments are equally suitable

Appraisal of salinity and fluoride in a semi-arid region of India using statistical and multivariate techniques

“The original publication is available at www.springerlink.com”. Copyright Springer. DOI: 10.1007/s10653-008-9222-5Various physico-chemical parameters, including fluoride (F−), were analyzed to understand the hydro-geochemistry of an aquifer in a semi-arid region of India. Furthermore, the quality of the shallow and deep aquifer (using tube well and hand pumps) was also investigated for their best ecological use including drinking, domestic, agricultural and other activities. Different multivariate techniques were applied to understand the groundwater chemistry of the aquifer. Findings of the correlation matrix were strengthened by the factor analysis, and this shows that salinity is mainly caused by magnesium salts as compared to calcium salts in the aquifer. The problem of salinization seems mainly compounded by the contamination of the shallow aquifers by the recharging water. High factor loading of total alkalinity and bicarbonates indicates that total alkalinity was mainly due to carbonates and bicarbonates of sodium. The concentration of F− was found more in the deep aquifer than the shallow aquifer. Further, only a few groundwater samples lie below the permissible limit of F−, and this indicates a risk of dental caries in the populace of the study area. The present study indicates that regular monitoring of groundwater is an important step to avoid human health risks and to assess its quality for various ecological purposes.Peer reviewe

Textural characteristics of the surface sediments of a tropical mangrove Sundarban ecosystem India.

397-403Surficial sediments of Sundarban Mangroves in West Bengal India have been studied for grain size spectrum and textural parameters namely phi mean, standard deviation, skewness and kurtosis. Grain size spectrum shows a marked variation in the upstream riverine stretch. Observed variation of energy conditions is controlled by the fluvial profile in the channel. Textural pattern is highly complex owing to the fluctuation in the physico-chemical conditions prevailing in the system. Textural analysis of very fine sand shows existence of comparatively low energy condition in the fluvial and mangrove creek zones. Linear Discriminant Function Analysis (LDF) of the samples indicates a shallow marine environment origin for all samples of the mangrove ecosystem. The riverine sediments also show a wide range of textural facies. They show a progressive enrichment of silty-sand in the downstream in the creeks. The CM diagram (C=one percentile in microns, M=Median in microns) of Sundarban suggests that sediment deposition takes place by (1) rolling (2) rolling and suspension and (3) graded suspension. The river and creeks sediments represent deposits are of uniform suspension. </b

A study of microbial diversity and its interaction with nutrients in the sediments of Sundarban mangroves

159-165Mangroves provide a unique ecological environment for diverse microbial communities. They are particularly important in controlling the chemical environment of the ecosystem. Sundarban, being a rapidly changing ecosystem, is under stress due to various anthropogenic activities. The present study was taken with an objective to assess the microbial (fungal and bacterial) diversity with respect to behaviour of nutrients. Three sampling location viz. Canning, Jharkhali and Pakhiralay, were chosen based on anthropogenic stress. It was observed that at Canning, nitrate (7.46 mg.L⁻¹) and phosphate (8.12 mg. L⁻¹) in water were maximum of all the three locations. Total bacterial load (29.83 × 10⁶), Phosphorus solubilising (14.08 × 10⁴ CFU.g⁻¹), N₂ fixing (13.67 × 10⁴ CFU.g⁻¹) and nitrifying bacteria (13.67 × 10⁴ CFU.g⁻¹) as well as exchangeable phosphorus (42 µg.g⁻¹) was highest in the sediments collected at Canning. Sediments associated with dense mangroves (Pakhiralay) showed highest count of cellulose degrading bacteria (45.15 × 10⁴ CFU.g-1). Fungal diversity was also assessed and it was observed that Aspergillus and Penicillium were the most abundant species in the three sampling locations. The study had elucidated the existing environmental conditions played a significant role in the determination of microbial diversity as well as nutrient behaviour in the sediments