Seasonal ovarian cycle in freshwater teleost, Labeo rohita (Ham.) in Tarai region of Uttaranchal

Seasonal ovarian cycle, based on histophysiological changes, and correlative variations in liver were studied in an Indian major carp, Labeo rohita reared in captivity under ambient environmental conditions in Tarai region of Uttaranchal. The oocyte features used for marking ovarian cycle included nuclear-ooplasmic ratio, yolk vesicle incorporation into ooplasm, number and size of nucleolus and differentiation of follicular layer. Based on these features the ovarian cycle in L. rohita was divided into five phases i.e. resting, preparatory, pre-spawning, spawning and post-spawning/regression. The resting and preparatory phases were characterized by the dominating presence of chromatin-nucleolar and yolk-vesicle stage oocytes. The pre-spawning phase ovary was marked by the prevalence of yolk globule stage oocytes having cortical alveoli and differentiating follicular wall. The oocytes containing densely packed yolk-granules and large masses of yolk vesicles and also exhibiting germinal vesicle movement (GVM) signified the ovary of spawning phase. The ovary in regression phase contained pre-ovulatory atretic oocytes and significant number of oogonia. The histophysiological changes in liver showing augmented biosynthetic activity during preparatory and pre-spawning phases seemed well correlated with the gonadal development. The increasing water temperature and day-length apparently was favourable for the gonadal development in L. rohita.     

Malachite green in synthetic medium for the isolation ofFusarium spp. from plant tissues

The Science of Nature -     

Moisture absorbers for food packaging applications

Environmental Chemistry Letters - Even though moisture in food products is useful for the quality of foods, excess moisture in a package is unfavorable to the quality of the food product and the...     

Application of remote sensing techniques toward the role of traditional water bodies with respect to vegetation conditions

Sri Lanka being an agrarian country, the role of water is important for agricultural production. In Sri Lanka, various tank cascade systems, earthen dams and distribution canals have been accepted as few of the most complex ancient traditional water systems of the world. Rainfall, surface water, groundwater and runoff are linked with each other, they have close interactions to land cover classes such as forests and agriculture. The monitoring of vegetation conditions can show subsurface manifestations of groundwater. In this study, an effort to understand the role of traditional water reservoirs and groundwater recharge was made using remote sensing techniques. We have analyzed various vegetation indices such as Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI-2), Soil-Adjusted Vegetation Index (SAVI), tasselled cap transformation analysis (TCA brightness, greenness and wetness) and their relations with the existence of soil, vegetation and water. Result shows that EVI, SAVI, and TCA-based Greenness Index indicates good relationship with the vegetation conditions as compared to other indices. Therefore, these indices could play a crucial role in depicting the interaction between soil, vegetation, and water. However, multi-temporal observations can provide significant results about these interactions more accurately.     

WATER TREATMENT PLANT STAGING POLICY1

Economics of treatment plant staging or capacity expansions is governed by the initial water demand rate, Q₀; the anticipated demand growth rate, G; the discount rate, D; the cost of operation, maintenance, and repair (OMR); the useful plant life, T, as a function of the quality of design, construction, and OMR; the treatment plant load factor, L_f; the salvage value of the plant at the end of the project period; the efficiency of the plant-staging design, eta; and the length of the project period, T_s. Various staging policies are investigated to find an optimal policy. The desirability of adopting a staging policy is governed by the magnitude of percent savings that can be achieved by adopting this policy instead of a no-staging policy. A detailed analysis of the problem shows that the percent savings because of staging increase with an increase in Q, G, D, T, and eta;. A reduction in the plant load factor increases the total costs. Information about the effect of variation in the parameters should help the planner and designer to work out an economical schedule of treatment plant capacity expansions.     

Effect of size variation of fibre-shaped waste tyre rubber as fine aggregate on the ductility of self-compacting concrete

Environmental Science and Pollution Research - Abandoning shredded waste tyre rubber (WTR) in cement-based mixes facilitates safe waste tyre disposal and conserves the natural resources used in...     

Estimation of uranium and radon concentration in some drinking water samples of Upper Siwaliks, India

Uranium and radon concentration was assessed in water samples taken from hand pumps, natural sources and wells collected from some areas of Upper Siwaliks, Northern India. Fission track registration technique was used to estimate the uranium content of water samples. The uranium concentration in water samples was found to vary from 1.08 +/- 0.03 to 19.68 +/- 0.12 microg l(-1). These values were compared with safe limit values recommended for drinking water. Most of the water samples were found to have uranium concentration below the safe limit of 15 microg l(-1) (WHO, World Health Organization, Guidelines for drinking-water quality (3rd ed.). Geneva, Switzerland: WHO, 2004). The radon estimation in these water samples was made using alpha-scintillometry to study its correlation with uranium. The radon concentration in these samples was found to vary from 0.87 +/- 0.29 to 32.10 +/- 1.79 Bq l(-1). The recorded values of radon concentration were within the recommended safe limit of 4 to 40 Bq l(-1) (UNSCEAR, United Nations Scientific Committee on the Effects of Atomic Radiations, Sources and effects of ionizing radiation. New York: United Nations, 1993). No direct correlation was found between uranium concentration and radon concentration in water samples belonging to Upper Siwaliks. The values of uranium and radon concentration in water were compared with that from the adjoining areas of Punjab state, India.     

DO-BOD modeling of River Yamuna for national capital territory, India using STREAM II, a 2D water quality model

The study illustrates the utility of STREAM II as a modeling package to determine the pollution load due to organic matter in the River Yamuna during its course through the National Capital Territory that is Delhi, India. The study was done for a period from 1995–2005. Model simulates the dissolved oxygen and biochemical oxygen demand parameters in a two-dimensional fashion by performing the numerical solution to a set of differential equations representing aquatic life with the help of Crank–Nicholson finite difference method. The model was simulated and calibrated through the field water-quality primary data and the secondary data which were taken from Central Pollution Control Board. The main reasons for the high river pollution is increasing population of Delhi and other states, leading to generation of huge amounts of domestic sewage into the river Yamuna. The model gave a good agreement between calibrated and observed data, thus, actualizing the validity of the model. However, discrepancies noticed during model calibrations were attributed to the assumptions adopted in the model formulation and to lack of field data.     

Bacterial contamination in drinking water: a case study in rural areas of northern Rajasthan, India

Acid deposition has caused detrimental effects on tree growth near industrial areas of the world. Preliminary work has indicated that concentrations of NO(3-), SO(4)(2-), F( - ) and Al in soil solutions were 2 to 33 times higher in industrial areas compared to non-industrial areas in Korea. This study evaluated soil nutrient bioavailability and nutrient contents of red pine (Pinus thunbergii) needles in forest soils of industrial and non-industrial areas of Korea. Results confirm that forest soils of industrial areas have been acidified mainly by deposition of sulfate, resulting in increases of Al, Fe and Mn and decreases of Ca, Mg and K concentrations in soils and soil solutions. In soils of industrial areas, the molar ratios of Ca/Al and Mg/Al in forest soils were <2, which can lead to lower levels and availability of nutrients for tree growth. The Ca/Al molar ratio of Pinus thunbergii needles on non-industrial sites was 15, while that of industrial areas was 10. Magnesium concentrations in needles of Pinus thunbergii were lower in soils of industrial areas and the high levels of acid cations such as Al and Mn in these soils may have antagonized the uptake of base cations like Mg. Continued acidification can further reduce uptake of base cations by trees. Results show that Mg deficiency and high concentrations of Al and Mn in soil solution can be limiting factors for Pinus thunbergii growth in industrial areas of Korea.