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Dissolved arsenic concentrations in the Ganges, Brahmaputra Rivers and confluence of these two rivers show important seasonal variations and maximum arsenic concentrations are observed during the monsoon season (July--October). These seasonal variations of dissolved arsenic concentrations were closely related to intense river-water discharge during the monsoon season with high arsenic-rich suspended particulate matter (SPM) loads. These arsenic-rich SPM mainly are primarily originated from erosion of agricultural land in upstream region irrigated with arsenic contaminated shallow groundwater and to some extent weathering of bed rocks. Considerable amount of iron and manganese enriched SPM adsorbs arsenic and increased water temperature in the summer accelerates microbially-mediated reduction of arsenic (V) to more soluble arsenic (III). Additionally, dissolution of solid arsenic-bearing mineral phases also attributes to high arsenic concentrations in water and causes seasonal variations. It is realized that the SPM of these two major rivers primarily controls the arsenic inputs into the Ganges-Brahmaputra-Meghna delta system. The cycling of arsenic in this delta is related to the monsoon seasonal dynamics, land use patterns and biogeochemical processes. [ABSTRACT FROM AUTHOR]

The crude methanolic extract of Dillenia indica Linn. (Dilleniaceae) leaves has been investigated for the evaluation of antimicrobial and cytotoxic activities. Organic solvent (n-hexane, carbon tetrachloride and chloroform) fractions of methanolic extract and methanolic fraction (aqueous) were screened for their antimicrobial activity by disc diffusion method. Besides, the fractions were screened for cytotoxic activity using brine shrimp (Artemia salina) lethality bioassay. Among the four fractions tested, n-hexane, carbon tetrachloride, and chloroform fractions showed moderate antibacterial and antifungal activity compared to standard antibiotic, kanamycin. The average zone of inhibition was ranged from 6 to 8 mm at a concentration of 400 mg/disc. But the aqueous fraction was found to be insensitive to microbial growth. Compared to vincristine sulfate (with LC50 of 0.52 μg/ ml), n-hexane and chloroform fractions demonstrated a significant cytotoxic activity (having LC50 of 1.94 μg/ml and 2.13 μg/ml, respectively). The LC50 values of the carbon tetrachloride and aqueous fraction were 4.46 mg/ml and 5.13 μg/ ml, respectively. The study confirms the moderate antimicrobial and potent cytotoxic activities of Dillenia indica leaves extract and therefore demands the isolation of active principles and thorough bioassay. [ABSTRACT FROM AUTHOR]

Background and Aims: Relaxin has an important role in stimulating motility and the acrosome reaction (AR) of fresh boar spermatozoa. The objective of the present study was to determine whether relaxin can improve the motility, AR and viability of cryopreserved boar spermatozoa. Methods: Cryopreserved boar spermatozoa were thawed, washed and incubated at 37°C for 4 h in modified Beltsville thawing solution supplemented with 0, 20 or 40 ng/mL relaxin. Sperm motility, AR, viability, and incorporation and oxidation of 14C-glucose were evaluated during 0–4 h of incubation. Results: The results show that the supplementation of relaxin (especially at 20 ng/mL) in the thawing solution improved sperm motility significantly ( P < 0.05) at 1–3 h of incubation. The percentage of acrosome reacted live spermatozoa was improved significantly ( P < 0.05) when the spermatozoa were treated with 20 ng/mL relaxin. Viability was not significantly ( P > 0.05) improved by supplementation with relaxin. The rates of incorporation and oxidation of 14C-glucose were increased in correlation with AR up to 4 h of incubation. Conclusion: We conclude that relaxin can improve the sperm motility and AR, and enhance the glucose metabolism of cryopreserved boar spermatozoa. (Reprod Med Biol 2006; 5: 215–220) [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the effects of dietary Rhodobacter capsulatus on the laying hen. A total of forty 23-wk-old Hy-Line Brown laying hens were randomly assigned into 4 treatment groups (10 laying hens/group) and fed diets supplemented with 0 (control), 0.01,0.02, and 0.04% R. capsulatus during the 60-d feeding period. Dietary supplementation of R. capsulatus (0.04%) reduced (P < 0.05) cholesterol and triglycerides concentration in serum (15 and 11%), as well as in egg-yolk (13 and 16%) over a 60-d feeding period. Cholesterol and triglycerides concentrations in serum as well as egg-yolk were changed linearly in accordance with increasing levels of dietary R. capsulatus. Supplementation of R. capsulatus in diets increased high-density lipoprotein cholesterol level and decreased (P < 0.05) atherogenic index in serum. Yolk color was improved (P < 0.05) in the group fed the 0.04% R. capsulatus supplemented diet compared with the control group. Hepatic cholesterol and triglycerides were reduced (P < 0.05) by 0.04% R. capsulatus. Moreover, the supplementation of R. capsulatus in layer diets did not appear to cause any adverse effects on egg production, shell weight, shell thickness, Haugh unit, yolk index, and feed conversion efficiency compared with the same parameters for the control laying hens. It is postulated that known and unknown factors are present in R. capsulatus presumably responsible for the hypocholesterolemic effect on laying hens. Therefore, the dietary supplementation of R. capsulatus may lead to the development of low-cholesterol chicken eggs as demanded by health-conscious consumers. [ABSTRACT FROM AUTHOR]