Effects of organic selenium supplemented diet on growth performance and antioxidant response in Cirrhinus mrigala

The present study was conducted to evaluate the …effect of dietary selenium on growth performance and antioxidant enzymes activity in Cirrhinus mrigala for a period of 45 days. Four numbers of experimental diets were prepared, T_c for Control (0 mg organic selenium/kg of diet), T₁ (2.5 mg organic selenium/kg of diet), T₂ (5.0 mg organic selenium/kg of diet) and T₃ (10 mg organic selenium/kg of diet). The water quality parameters (temperature, DO, pH, conductivity, hardness, ammonia, nitrate and nitrite) were found to be insignificant (p > .05) among all the treatments. Superoxidase dismutase (SOD) was found to be significantly highest in T₂ (6.10 ± 0.07) when compared with the other treatments. Similarly, catalase (CAT) activity in T₁ (13.21 ± 0.13) was significantly (p < .05) different with that of Control, T₂ and T₃. Present study also revealed that 2.5mg organic selenium/kg supplemented diet (T₁) showed highest results in net weight gain (15.55 ± 1.36 g), net weight gain percentage (185.88 ± 8.98%) and SGR (2.35 ± 0.06 g) compared with other experimental diet.     

Effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis) spermatozoa

The effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis) spermatozoa was investigated. Semen samples were collected from five healthy mithun bulls through rectal massage method and cryopreserved in liquid nitrogen. The samples were diluted in Tris–egg yolk–glycerol extender, equilibrated for 4 h at 4 °C and loaded into 0.50‐ml straws. The straws were then frozen in liquid nitrogen vapour for 10 min and finally plunged into liquid nitrogen for storage. The required amount of glycerol was added into the diluted samples either in a single dose (3%, 4%, 5%, 6% or 7%; added at 37 °C immediately before equilibration) or in split doses (5%, 6% or 7%; the total amount was divided into four equal parts, and a part was added at 37 °C immediately before equilibration, and the remaining parts were added subsequently at 1, 2 and 3 h of equilibration at 4 °C). In the single‐dose addition method, following freeze‐thawing, greater (p < 0.05) motility (%) and proportion of live spermatozoa with intact acrosome (LSIA, %) in 5% glycerol (40.6 ± 1.7 and 43.4 ± 1.8 respectively) and lesser (p < 0.05) total morphological abnormalities (%) in 5% (14.1 ± 0.8) and 6% (13.7 ± 1.0) glycerol were observed compared to the other glycerol concentrations. In the split‐dose addition method, following freeze‐thawing, greater (p < 0.05) motility (%) and LSIA proportion (%) were found in 5% (50.2 ± 1.9 and 53.3 ± 1.8 respectively) compared to 6% or 7% glycerol, but the total morphological abnormalities were not different among the glycerol concentrations. In addition, in all the glycerol concentrations, better (p < 0.05) post‐freeze‐thaw motility and LSIA proportions were observed when glycerol was added in split doses compared to a single dose. In conclusion, Tris–egg yolk extender with 5% glycerol added in split doses was found most suitable for cryopreserving mithun sperm.     

Removal of Fluoride from Water by Locally Available Sand Modified with a Coating of Iron Oxides

Locally available low-cost material viz. sand from the Kaliani river of Kanaighat area of Golaghat district Assam, India, was collected. The sand was fractionated and the different fractions were characterized by classical chemical analysis, powder XRD, SEM-EDXA, DTA-TGA, and by FT-IR. The chemical analysis of the size fraction of a 600–850-μm range gave more than 90% silica. This fractionated portion was modified by coating with iron oxide. Coating was carried out on the washed and separated sand by repeated treatment of Fe(NO₃)₃ at 110 and 600 °C, respectively. From FESEM analysis, formation of iron oxide coating over sand surface is clearly observed. The coated sand was used to remove toxic fluoride ion from the drinking water. Iron oxide-coated sand shows highly improved fluoride removal capacity compared to raw sand. The defluoridation capacity of coated sands rose up to 89% from 7% in uncoated raw sand. The effects of different parameters like adsorbent dose, contact time, temperature, initial fluoride concentration, and pH and the effects of different anions present in water along with arsenic on defluoridation capacity of the material were studied in a batch mode.     

Gaseous Emissions During the Coal Mining Activity and Neutralizing Capacity of Ammonium

This paper presents the simultaneous measurement of atmospheric concentration of gaseous NH₃, SO₂ and NO₂, and particulate NH ₄ ⁺ released from the mining activities of coal-mine area, Tirap colliery, Margherita (Assam). Gas samples were collected by impinger method and were analyzed colorimetrically. The vapor-phase concentration of NH₃, SO₂, and NO₂ range between 4.7?C40.03, 1.47?C6.14, and 1.92?C2.40???g/m³. The NH ₄ ⁺ concentration in PM₁₀ and PM_2.5 ranges between 0.02?C0.07 and 0.008?C0.03???g/m³, respectively. Moderately high concentrations of NH₃ and SO₂ on the first day were due to the coal-burning activity near the sampling site, while the low concentration of NO₂ is due to less vehicle density near the sampling point. All the observed concentrations are below than those reported for the urban areas and the prescribed limit fixed by National Ambient Air Quality Standard, India. Study indicates that ammonia is the major neutralizing agent for sulfate and nitrate ions present in the particulate matter during mining activities.     

Toxicity of a synthetic phenolic antioxidant,butyl hydroxytoluene (BHT), in vertebrate model zebrafish embryo (Danio rerio)

The synthetic antioxidant 3,5‐di‐tert‐butyl‐4‐hydroxytoluene (BHT) is widely used as an additive in the food, cosmetic and plastic industries to increase the tenability of food and plastic for the past 70 years. BHT is degraded to 3,5‐di‐test‐butyl‐4‐hydroxybenzaldehyde (BHT‐CHO) in mammals, as well as in the natural environment such as in river and water. The average daily intake of BHT for human being is estimated to be 0.3 mg/kg body weight. Even though it is considered safe for human at authorized level, but its ubiquitous presence in the aquatic environment and the controversial toxicological data are of great concern for human as well as aquatic life. The experimental findings of zebrafish embryo toxicity test (ZFET) showed that the acute toxicity of 96‐hr (LC₅₀) exposure during the embryogenic stage was found to be 4.388 mg/L and the effective concentration (EC₅₀) was 1.375 mg/L. The reduce heart rate from the sublethal concentrations indicates the chemical to be cardiotoxic but a further review is to be needed. The Teratogenic Index (TI) calculated to be 3.19, which implies the compound may be a potential teratogen in aquatic life. The findings obtained in this study will stretch more evidence regarding developmental toxicity of BHT, which will be of much importance in further risk assessment of ecotoxicological studies.     

Genetic diversity among rattan genotypes from India based on RAPD-marker analysis

Southeast Asia hosts a great diversity of different rattan genotypes. There are 5 genera and 60 different species of rattan in India and the Northeastern region is a natural sanctuary for 4 different genera and 16 different species. The natural reserves of this species have come under the threat of genetic erosion due to overexploitation. This investigation was directed at characterizing 15 rattan genotypes of the genera Calamus, Plectocomia and Daemonorops which yield rattans of commercial importance, based on RAPD fingerprints. From 20 different random decamer primers, 12 primers gave reproducible amplification profiles and 104 polymorphic bands. A considerable degree of polymorphism (98.1%) was detected among the genotypes. Jaccard’s coefficient of similarity ranged from 0.146 to 0.632 with a mean of 0.320±0.082, signifying extensive genetic divergence among the genotypes studied. UPGMA cluster analysis clearly distinguished P. assamica Griff. and C. erectus Roxb. The other 13 genotypes were grouped into two distinct clusters, one cluster involving two C. tenuis genotypes along with C. inermis T.Anders. and C. acanthospathus Griff. and the other cluster involving the rest of the Calamus genotypes along with D. jenkinsianus (Griff.) Mart. Unique fingerprints for 7 Calamus and 1 Daemonorops genotypes were detected. The results presented in this paper demonstrated the utility of RAPD markers in elucidating patterns of genetic variation among genotypes of the three main rattan genera of Northeast India and in identifying individual genotypes, which may serve as potential sources of unique genetic material for genetic improvement and conservation.     

ISSR and SSR markers reveal sex-specific DNA sequences in three <Emphasis Type="Italic">Calamus</Emphasis> species from India

Calamus species yields the raw materials for the cane industry. However, the extraction of the cane from the forests is being carried out indiscriminately without considering the sustenance of the species. Plants of both sexes should co-exist for reproductive success. The sex of Calamus plants can be identified only after flowering and hence proper planning of managed forestry practices cannot be accomplished. A study was carried out in this background and male specific ISSR markers for C. tenuis and C. flagellum and SSR markers for C. thwaitesii were identified. The diagnostic potential of these markers can be exploited to sex the Calamus species at the seedling stage for proper breeding and agroforestry management.     

Hydrolysis of sulfonylurea herbicides in soils and aqueous solutions: a review

Sulfonylureas are a unique group of herbicides used for controlling a range of weeds and some grasses in a variety of crops and vegetables. They have been extremely popular worldwide because of their low mammalian toxicity, low use rate, and unprecedented herbicidal activity. Knowledge about the fate and behavior of sulfonylurea herbicides in the soil-water environment appears to be of utmost importance for agronomic systems and environmental protection. Because these herbicides are applied at a very low rate, and their mobility is greatly affected by the chemicals' anionic nature in alkaline soils, a thorough understanding of their degradation/hydrolysis processes and mechanisms under aqueous and soil systems is important. This review brings together published information on the hydrolysis of several sulfonylureas in aqueous and soil solutions that includes the effects of pH, temperature, functional relationship between pH vs hydrolysis rate constants, and hydrolysis behavior of sulfonylureas in the presence of minerals. In addition, the transformations of sulfonylureas in soil, under laboratory and field experiments, have been discussed in connection with the compounds' varied structural features, i.e., sulfonylueas that are with or without the pyridinic, pyrimidine, and triazinic ring.     

Hexadecane mineralization activity in hydrocarbon-contaminated soils of Ross Sea region Antarctica may require nutrients and inoculation

Hydrocarbon spills on Antarctic soils occur mainly near settlements where fuel is stored and aircraft and vehicles are refuelled. To investigate those factors that may preclude hexadecane mineralization activity in long-term hydrocarbon-contaminated soils from the Ross Sea Region, samples were collected from Scott Base, the site of former bases (Cape Evans, Marble Point, Vanda Station), and two oil spill sites in the Wright Valley (Bull Pass and Loop Moraine). The soils had low levels of nitrogen (<0.1% total N) and a high C/N ratio (>24) reflecting hydrocarbon contamination. Following soil water adjustment to 10% (v/w), the influence of nutrient addition (250 mg/kg N added as monoammonium phosphate) and inoculation (spiking with Antarctic soil containing high numbers of hydrocarbon degraders) as required on hexadecane mineralization activity was determined. Hexadecane mineralization activity occurred in contaminated soils from Marble Point, Cape Evans and one sample from Vanda Station without nutrient addition. In contrast soils from Scott Base, Cape Evans, another sample from Vanda Station and Loop Moraine required nutrients, whereas Bull Pass soil required inoculation and nutrients before hexadecane mineralization proceeded. Hydrocarbon degrader numbers were highest in coastal soils from Scott Base and Marble Point (10⁷ per gram) and less prevalent in inland soils from Wright Valley (<10⁵ per gram). The bacterial community structure of the soils differed between sites, but soils from the same sites tended to cluster together more closely, except for those from Vanda Station. Addition of nutrients did not cause large shifts in the soil bacterial communities. Results from this study indicate that hydrocarbon degradation may occur at some sites in summer when water is available. Long-term hydrocarbon-contaminated Antarctic soils may provide a valuable resource of hydrocarbon-degrading bacteria that can serve as inocula for more recent oil spills on land.