Wet Deposition of Trace Metals in Singapore   总被引：3，自引：0，他引：3  

Hu  G.-P.  Balasubramanian  R. 《Water, air, and soil pollution》2003,144(1-4):285-300

The concentrations of 12 trace metals (Al, Cd, Cr, Cu, Co, Fe,Mn, Ni, Pb, Zn, V, and Ti) in wet depositions are reported. Eighty four rainwater samples were collected using an automated wet-only sampler in Singapore for one year (2000) and subjected to chemical analysis using ICP-MS. Based on the volume-weighted meanconcentrations measured, the trace metals were classified into three groups: Al and Fe with an average concentration of largerthan 15 μg L^-1, Cr, Cu, Mn, Ni, Pb, Zn, V, and Ti withconcentrations between 1 and 10 μg L^-1, and finally Co and Cd with concentrations lower than 1 μg L^-1. Elementenrichment factors were calculated to distinguish between naturaland anthropogenic sources. The calculation of crustal enrichmentfactors with Al as the reference element indicated that while Ti,Fe and Mn originated from crustal sources, the remaining trace metals (Cd, Cr, Co, Cu, Ni, Pb, Zn and V) were mainly derived from anthropogenic sources. The removal of the trace metals from the atmosphere by precipitation was influenced by the rainfall amount as well as pH. The magnitude of the measured average annual wet deposition fluxes of Al, Fe, and combustion-generatedelements such as V, Ni, and Cu is higher than that reportedfor other sites outside Singapore, owing to abundant rainfallthroughout the year in this region.  相似文献   

Land configuration and soil nutrient management options for sustainable crop production on Alfisols and Vertisols of southern peninsular India     

R. Selvaraju  P. Subbian  A. Balasubramanian  R. Lal 《Soil & Tillage Research》1999,52(3-4):203-216

Land configuration in combination with nutrient management has the potential to improve the productivity of Alfisols and Vertisols in the semi-arid tropics. A four year (1989–1990 and 1992–1993) field experiment was conducted at Coimbatore, India on Alfisols (Chromic Cambisol) to compare the effect of land configuration and nutrient management practices on yield of rainfed sorghum (Sorghum bicolor (L.) Moench). The land configuration treatments were flat bed (FB, the traditional practice), open ridging (OR, ridges, 45 cm apart and 30 cm high) and tied ridging (TR, same as OR plus ridges were tied randomly). The manure and fertilisers were farm yard manure (FYM, livestock excreta plus litter at 5 Mg ha⁻¹) and coir dust (CD, by-product after the extraction of coir from the coconut (Cocos nucifera L.) husk at 12.5 Mg ha⁻¹) in combination with nitrogen (N) and phosphorus (P) fertiliser levels. Tied ridges stored 14% more soil water and produced 14% and 11% more grain and straw yields of sorghum, respectively, than did flat bed. However, crop yield in TR was comparable with OR. Application of CD at 12.5 Mg ha⁻¹ combined with 40 kg N ha⁻¹ and 9 kg P ha⁻¹ was beneficial for more soil water storage and increased yield of sorghum by 7% over FYM at 5 Mg ha⁻¹ + 40 kg N ha⁻¹ and 9 kg P ha⁻¹. In Vertisols (Vertic Cambisols), experiments were conducted for two years (1991–1992 and 1992–1993) to evaluate land configuration practices. The treatments were broad bed furrow (BBF, 120 cm wide bed with 30 cm wide and 15 cm deep furrows on both sides), compartmental bunding (CB, bunds of 15 cm height formed in all the four sides to form a check basin of 6 m × 5 m size), ridging (RD, ridges were formed for each and every row of the crop manually at four weeks after sowing) and FB under sorghum + pigeonpea (Cajanus cajan (L.) Millsp) and pearl millet (Pennisetum glacum (L.) Stuntz) + cowpea (Vigna unguiculata (L.) Walp) intercropping separately. Compartmental bunding stored 22% more soil moisture and increased the yield of sorghum + pigeonpea intercropping than did FB in a low rainfall year. In a high rainfall year, BBF produced 34% and 33% more grain yield of sorghum and pearl millet base crops, respectively, over FB. However, BBF and CB were comparable. Pigeonpea intercrop under sorghum followed the same trend as its base crop, whereas, yield of cowpea differed compared to the pearl millet base crop. Tied ridging and application of manures (CD or FYM) in combination with inorganic N and P fertiliser can increase the soil water storage and yield of crops compared to traditional flat bed cultivation in rainfed Alfisol and related soils of semi-arid tropics. Similarly BBF and CB land configuration practices could be adopted on Vertisols for better water conservation to increase the soil fertility and productivity of intercropping systems.  相似文献   

Cellular Composition and Viability of Cloned Bovine Embryos Using Exogene-Transfected Somatic Cells     

S-L Lee  BM Kumar  J-G Kim  S-A Ock  B-G Jeon  S Balasubramanian  S-Y Choe  G-J Rho 《Reproduction in domestic animals》2007,42(1):44-52

The present study compared the efficiency of transgenic (TG) cloned embryo production by somatic cell nuclear transfer (SCNT) with fetal-derived fibroblast cells (FFCs) which were transfected with pEGFP-N1 to in vitro-fertilized (IVF), parthenogenetic and SCNT counterparts by evaluating the rates of cleavage and blastocyst formation, apoptosis rate at different developmental stages, cell number, ploidy and gene expression in blastocysts. In SCNT and TG embryos, the rates of cleavage and blastocyst formation were significantly lower (p < 0.05) than those of IVF controls, but it did not differ between SCNT and TG embryos. In IVF control, 86.7% embryos displayed diploid chromosomal complements and the rates were significantly (p < 0.05) higher than those of SCNT and TG embryos. Most TG embryos (79%) with FFCs expressed the gene by both PCR and under fluorescence microscopy. The expression of apoptosis by TUNEL was first detected at six to eight cell stages in all embryos of IVF, SCNT and TG groups, but the expression rate at each developmental stages was significantly higher (p < 0.05) in SCNT and TG embryos than in IVF counterparts. The expression rate in inner cell mass (ICM) of TG embryos was significantly higher (p < 0.05) than in SCNT and IVF embryos. These results indicate that the high occurrence of apoptosis observed in SCNT and TG embryos compared with IVF counterparts might influence the developmental competence. Moreover, the SCNT embryos derived using non-transfected donor cells exhibited a lower apoptosis expression in ICM cells than in TG embryos derived using pEGP-N1-transfected donor cells suggesting a possible role of negative gene effect in TG embryos.  相似文献   

Ochratoxin A: Carryover from animal feed into livestock and the mitigation strategies     

Abirami Ramu Ganesan  Balamuralikrishnan Balasubramanian  Sungkwon Park  Rajesh Jha  Ines Andretta  Archibold G. Bakare  In Ho Kim 《动物营养（英文）》2021,7(1):56

This review aims to highlight the effects of ochratoxin A (OTA) in the feed of meat-producing animals. The accumulation of OTA in feed and its distribution in various farm animals were compared and evaluated. Primarily, the oral administration of OTA-contaminated feed and the predisposition in an animal''s vital organ were critically examined in this work. The collated reports show that OTA directly associated with endemic nephropathy and its high concentration leads to degeneration of liver cells, and necrosis of intestinal and lymphoid tissues. At present, limited reports are available in the recent literature on the problems and consequences of OTA in feed. Therefore, this review focused on the OTA carryover from feed to farm animals and the interaction of its secondary metabolites on their biochemical parameters. Hence, this report provides greater insights into animal health related to OTA residues in meat and meat products. This article also explores mitigation strategies that can be used to prevent the carryover effects of OTA in livestock feeds and the effects in the food chain.  相似文献   

Measurement of Major Organic Acids in Rainwater in Southeast Asia during Burning and Non-Burning Periods     

Z. C. Zhong  T. Victor  R. Balasubramanian 《Water, air, and soil pollution》2001,130(1-4):457-462

Rainwater samples were collected in Singapore from August to December 1997 using a wet-only collector. Major organic acids were analyzed in all collected samples, using Ion Chromatography, with concentrations ranging from 1.4 to 105.6 µeq/l (mean = 17.6 µeq/l) for formate and from 1.7 to 62.8 µeq/l (mean = 16.7 µeq/l) for acetate, respectively. Elevated concentrations of both formate and acetate were observed during the months of September and October when the biomass burning impacted air masses originating from Indonesia had arrived at Singapore and prevailed there. The formate to acetate ratio was greater than 1 in biomass burning plumes suggesting that formic acid was likely produced in the atmosphere in addition to its direct emission from fires. Both formate and acetate together accounted for as much as 68 % of unneutralized total acidity in rain during the burning period. Our results suggest that biomass burning is an important source of HCOOH and CH₃COOH to the troposphere over Southeast Asia.  相似文献   

Legal Concerns with Providing Hospice and Palliative Care     

Amir Shanan  Vandhana Balasubramanian 《Veterinary Clinics of North America: Small Animal Practice》2011,41(3):661-675

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Studies on the inactivation of white spot syndrome virus of shrimp by physical and chemical treatments, and seaweed extracts tested in marine and freshwater animal models   总被引：1，自引：0，他引：1  

Balasubramanian G  Sudhakaran R  Syed Musthaq S  Sarathi M  Sahul Hameed AS 《Journal of fish diseases》2006,29(9):569-572

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Assessment of Soil Phosphorus Balance: Application of Dynamic Nutrient Balance Approach to South Indian Agricultural Farming System     

R. Paramasivam  P. Paramasivam  M. Umanath  R. Balasubramanian 《Communications in Soil Science and Plant Analysis》2017,48(17):2032-2048

This study applied a dynamic nutrient balance method to estimate a stock of soil phosphorus and its usage pattern. We used panel data of published agricultural production, fertilizers supply, and livestock population to assess the net inflows, outflows, and stock of phosphorus in 19 regions of Tamil Nadu in the years 1990–2012. The dynamic model supported us to find pattern of phosphorus stocks and flow over the period, and more importantly, the total phosphorus outflow breakdown into removal by crop, soil, air, and water. This model simultaneously assesses the phosphorus stock, flows, and outflows inclusion of time factor, and thus it is one of robust agricultural environmental indicators. This paper will support the farmers and stakeholders to take an appropriate policy according to status of nutrient in the estimated agricultural regions.  相似文献   

Effect of FMD vaccine antigen payload on protection, sub-clinical infection and persistence following needle challenge in sheep     

Muthukrishnan Madhanmohan  Singanallur Balasubramanian Nagendrakumar  Mangamoori Lakshmi Narasu  Villuppanoor Alwar Srinivasan   《Comparative immunology, microbiology and infectious diseases》2010,33(6):e7-e13

The relationship of Foot-and-Mouth Disease (FMD) virus antigen payload and single and double vaccinations in conferring protection against virus challenge in sheep was studied. Sheep vaccinated with half the cattle dose (1 ml) containing 15 and 3.75 μg of FMDV antigen with or without booster resisted virulent challenge on 21 days post vaccination or 7 days post booster. FMDV RNA could be detected in nasal secretions in 26% of vaccinated sheep (10^3.12 to 10^3.82 viral RNA copies) on day 35 post challenge. No live virus could be isolated after 5 days post challenge indicating that the risk of transmission of disease was probably very low. The finding showed that vaccines containing antigen payload of 1.88 μg may prevent or reduce the local virus replication at the oropharynx and shedding of virus from nasal secretions and thereby reduce the amount of virus released into the environment subsequent to exposure to live virus. Sheep with no vaccination or with poor sero conversion to vaccination can be infected without overt clinical signs and became carriers.  相似文献   

Stimulation of ovarian growth by methyl farnesoate and eyestalk ablation in penaeoidean model shrimp,Sicyonia ingentis Burkenroad, 1938     

Balasubramanian Changaramkumarath Paran  Isidro Jose Fierro  Brian Tsukimura 《Aquaculture Research》2010,41(12):1887-1897

The effect of methyl farnesoate (MF) administration on the vitellogenesis of the penaeoidean shrimp, Sicyonia ingentis, was studied. The short‐ and long‐term treatment effects as well as the effect of two MF injection regimens (0.1 and 1.0 μg MF/injection) were evaluated. The studies were also carried out to understand the pattern of vitellogenesis in eyestalk ablated adult and juvenile shrimps. A combination of endpoints, haemolymph vitellogenin (Vg) levels, gonadosomatic index (GSI) and histology, was used to study the effect of these treatments. The GSI increased in all the MF‐treated shrimp compared with the control shrimps. Although haemolymph Vg levels declined over the experimental period in all the treatments, the Vg levels decreased significantly only in the short‐term treatment with 1.0 μg MF. Similarly, haemolymph protein level also declined over the experimental period in all the treatment groups. However, except in the long‐term treatment with 0.1 μg MF, all treatments showed a significant decrease in haemolymph protein level. Conversely, in all eyestalk ablated adults and juveniles, haemolymph Vg, total protein and GSI increased over the experimental period, all of which were higher than the concurrent control. The discrepancy in the vitellogenic pattern between MF‐treated and eyestalk ablated shrimp was possibly due to the difference in the ovarian phase of the initial control. Although unilateral eyestalk ablation failed to induce vitellogenesis in juveniles, bilateral ablation induced vitellogenesis, which indicates that juveniles are competent to undergo vitellogenesis.  相似文献