Larvae (15 to 21 d post hatch, dph) of the Asian sea bass Lates calcarifer (Bloch) suffered heavy mortalities (60 to 90%) during the hatchery-rearing phase. Darkened and moribund larvae showed no evidence of bacterial or parasitic infections. Tissue sections of brain and spinal cord showed clear necrotic vacuolation. Electron microscopy revealed membrane-bound viral particles in the cytoplasm of the nerve cells. The viral particles measured 28 to 30 nm in diameter. Primer sets, designed for the amplification of the RNA2 segment of the piscine nodavirus coat protein gene, were used in the RT-PCR analysis of moribund larvae of 20 and 21 dph which produced the amplified product of 430 bp. The clinical manifestations, pathology and electron microscopy observations supported by the RT-PCR analysis suggest that the nerve necrosis was due to nodavirus infection in the larvae. This is the first report of piscine nodavirus infection from the Indian sub-continent. KEY WORDS: Nodavirus · Lates calcarifer · Larvae · RT-PCR · Histopathology · Nervous necrosis virus Resale or republication not permitted without written consent of the publisherDis Aquat Org 63: [113][114][115][116][117][118] 2005 geographical locations have been reported to be susceptible to the virus (Glazebrook et al. 1990, Yoshikoshi & Inoue 1990, Mori et al. 1992, Muroga 1995, Comps et al. 1996, Munday & Nakai 1997, Castric et al. 2001. The disease has also been reported in freshwater aquarium fish from Singapore (Hegde et al. 2003).Histology and RT-PCR are the common methods used for diagnosis of the virus in fish (Mori et al. 1991, Munday et al. 1992, Nishizawa et al. 1994, Grotmol et al. 1995, Lai et al. 2001, Johansen et al. 2002, Hegde et al. 2003. Diagnosis of piscine nodavirus using RT-PCR for the T4 region (427 bp) of SJNNV coat protein gene (RNA2) has been widely used and many workers have reported positive amplification for the presence of the nodavirus in fish species from different geographical locations (Nishizawa et al. 1994, Castric et al. 2001, Curtis et al. 2001, Lai et al. 2001. Primer sequences of Nishizawa et al. (1994) have been recommended for the diagnosis of the piscine nodaviruses (OIE 1997).A batch of Asian sea bass larvae produced in the fish hatchery facilities of the Central Institute of Brackishwater Aquaculture were observed to experience sudden and unexplained mortality after 15 d of larval rearing. Subsequent investigations revealed that the cause of the disease was piscine nodavirus. The present investigation represents the first report of VNN from the Indian sub-continent and extends the known range of this disease. MATERIALS AND METHODSFish. Broodstock procured from the coastal waters of Chennai (Madras), acclimatized and maintained in cement tanks are being used for the purposes of seed production. Since 1997 more than 15 batches of Asian sea bass larvae have been produced in the institute facility. Though the hatchlings were sampled from 0 d post hatch (dph) for routine histology, the larvae from 15 to 2...
Purpose Biochar has potential as a valuable tool for the agricultural industry with its unique ability to help build soil health, increase physical properties of soil, soil pH, organic carbon content, conserve water and mitigate drought, reduce GHG emission, conserve nutrients, decrease fertilizer requirements, sequester carbon, increase crop productivity and serve as a most preferred habitat for microbes. In this study, three perishable biomass wastes viz. Pea pod (Pisum sativum), cauliflower leaves (Brassica oleracea) and orange peel wastes (Citrus sinensis) were carbonized and characterized for differential application. Methods The biomass was subjected to carbonization at different temperatures from 100 to 600°C for 1 h. Biomass and biochar samples were characterized for proximate (M, VM, FC, Ash), ultimate (CHNS-O), biochemical properties (Ce, He, Li), thermo gravimetric analysis, pH, EC and bulk density. The biochars were also analyzed through SEM and FTIR for identification of pore size and functional groups. Results The char yield was high in cauliflower leaf (30.16 %), followed by orange peel (25.54 %) and pea pod (21.154 %) at 300°C. The total organic carbon (11.61 %), total negative surface anions (4.25 mmol H ? eq/g C) and water holding capacity (200 %) were high in pea pod biochar. The SEM images of biochar samples showed plane cleavage surfaces with broken edges. The surface functional groups of all the three biochar samples were hydroxyl, methyl, carboxylic and alkene groups. Conclusion The pea pod and cauliflower leaf biochar showed higher values of organic carbon, total surface anions, water holding capacity and mineral content and performed as best soil amendment than orange peel biochar. These biochar can be used as an effective medium for increasing soil carbon, irrigation efficiency and efficient disposal of agricultural waste-biomass.
This work deals with optimizing the conditions of pyrolysis and type of activator to upgrade the use of Casuarina equisetifolia fruit waste (CFW) as available and a potential precursor, in production of activated carbon (AC). In this respect, the route of activation was carried out through one- and two-step pyrolysis processes, using different chemical activating agents, such as H3PO4, KOH and ZnCl2. The performance of the CFW-based ACs is assessed by estimating the physico-chemical characteristics (pH, electrical conductivity, bulk density and hardness), surface morphology and scanning electron microscopy, together with carbon yield, surface area and adsorption performance of pollutants in aqueous medium (methylene blue, iodine and molasses colour removal efficiencies). The results show that the two-step activation process was more effective than one-step activation for providing high adsorption performance CFW-based ACs. The maximum Brunauer–Emmett–Teller surface area 547.89 m2 g−1 was produced by using H3PO4 activating agents, and applied two-step pyrolysis. According to the American Water Work Association and based on bulk density of the investigated ACs, we recommend that most of produced ACs are suitable for treating waste water.
For many women and children around the world, staying at home is no longer a safety aspect during the Covid-19 pandemic. There is a surge in the number of cases of inter-personal violence and child abuse during the lockdown. The stigma and socio-cultural norms create hesitance in subjecting the family and its intimate relationships to public scrutiny. Therefore, building awareness around domestic violence is vital.
The key objective of this study was to assess the suitability of soil and source water quality of abandoned shrimp farms in selected coastal states of India, for resuming aquaculture activities. Soil samples along with associated source water were collected from 60 disused shrimp ponds in different districts of Andhra Pradesh, Tamil Nadu, Odisha and Kerala and analysed for basic physico-chemical parameters. Results of the analysis indicated that the reason for disuse might be reduction in price/repeated occurrences of diseases and that the sampled farms are suitable for aquaculture use. Most of the soil in Andhra Pradesh and Tamil Nadu are suitable for aquaculture without any remediation. Few ponds in Jagatsingpur and Puri districts of Odisha and Kerala needs simple remediation measures like application of lime to increase the soil pH. Source water in Tamil Nadu, Andhra Pradesh and Odisha (Harishpur Creek, Budhabalanga Creek and the coastal canal) fall under high saline areas and are suitable for culture of tiger shrimp Penaeus monodon, white shrimp Litopenaeus vannamei and finfishes like Asian seabass Lates calcarifer and mullets whereas, Kerala and northern parts of Chilka Lake of Odisha fall under low saline areas and are suitable for culture of white shrimp L. vannamei and pearlspot Etroplus suratensis.
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