A mechanized harvest system for freshwater fishpond     

K.K. Sharma  Bikash Sarkar  S. Chand  S.K. Nayak 《Aquacultural Engineering》2009,41(3):147-151

Development of a prototype-mechanized fish harvesting system for carp from a rectangular shaped fishpond is described in this paper. The system consists of motorized trolleys on the longer dykes of fishpond, rail, boom pipe, netting arrangement and ON/OFF arrangements. The trolleys move on the rail tracks with constant speed of 3 m/min and takes about 15 min to complete the harvesting operation. The overall mean harvest efficiency of Indian major carps (IMC) with mechanized fish harvesting system has been estimated to be around 80% per operation. The whole harvesting operation is done mechanically except collection of harvested fishes at the end of operation, which presently requires two persons getting into the pond and lifting out the fishes from the net.  相似文献   

Autoregressive technique in length growth modelling of two Indian major carp, Catla catla (Hamilton) and Labeo rohita (Hamilton), reared under two holding conditions     

T K Basu  B Bhattacharyya  S K Sarkar  S Ganguly  C Medda 《Aquaculture Research》1998,29(9):625-634

An autoregressive analysis was performed on data from an investigation of the velocity and acceleration of the day-to-day length increments of two Indian major carp, Catla catla (Hamilton) and Labeo rohita (Hamilton), hatched in artificial (Chinese-style hatchery) and semi-natural (improvised pits) holding conditions. The autoregressive model, which was capable of providing short- and long-term predictions, was tested in parallel with a time regressive model and an instantaneous growth rate model. The estimate simulating short-term predictions was found to describe the data more efficiently than the other estimates of the models. Product-moment correlations comparing the two holding systems revealed no source-specific variation of growth between the species. However, the significant length velocity correlation suggests that the artificial system has greater efficacy.  相似文献   

Assessment of Variation in Morpho-Physiological Traits and Genetic Diversity in Relation to Submergence Tolerance of Five Indigenous Lowland Rice Landraces     

Barik Jijnasa  Kumar Vajinder  K. Lenka Sangram  Panda Debabrata 《水稻科学》2020,27(1):32-43

The present study evaluated submergence responses in 88 lowland indigenous rice(Oryza sativa L.) landraces from Koraput, India, to identify submergence-tolerant rice genotypes. In pot experiments, variations in survival rate, shoot elongation, relative growth index, dry matter, chlorophyll, soluble sugar and starch contents were evaluated in two consecutive years under well-drained and completely submerged conditions. Principal component analysis showed that the first three axes contributed 96.820% of the total variation among the landraces, indicating wide variation between genotypes. Major traits such as survival rate, relative growth index, soluble sugar and starch contents appeared to be important determinants of phenotypic diversity among the landraces. Phenotypic coefficient of variance was higher than genotypic coefficient of variance for all the traits and all showed high heritability(90.38%–99.54%). Five rice landraces(Samudrabali, Basnamundi, Gadaba, Surudaka and Dokarakuji) were the most tolerant to submergence. When submerged for up to 14 d, Samudrabali, Basnamundi and Godoba were notable for having greater survival rates than a standard submergence tolerant variety FR13 A, and also notable for elongating more vigorously and accumulating more biomass. These three landraces may therefore be especially useful in lowland rice growing areas that are affected by both moderate stagnant water and flash flooding. Molecular genotyping revealed that the submergence tolerance of Samudrabali, Basnamundi and Godoba is linked to the presence of one or more different Sub1 loci and it may well prove useful for breeding improved submergence tolerant rice varieties, thereby assising to improve yield stability in the rainfed lowland agro-ecosystem.  相似文献   

Karyotype analysis and chromosomal evolution in Asian species of Corchorus (Malvaceae s. l.)     

Prosanta Saha  Debabrata Sarkar  Avijit Kundu  Subhabrata Majumder  Swapan K. Datta  Karabi Datta 《Genetic Resources and Crop Evolution》2014,61(6):1173-1188

Here, we report the karyotypes and mean haploid idiograms of the ten Asian Corchorus species (2n = 2x = 14). Chromosomes were small, with a mean chromosome length of 2.30 μm. The largest chromosome was recorded in C. pseudo-olitorius (3.50 μm) and the shortest in C. pseudocapsularis (1.60 μm). The karyotypes of the two cultivated species (C. capsularis and C. olitorius) and C. pseudo-olitorius were the most diverse and specialized, whereas those of C. depressus and C. trilocularis were the least diverse. C. fascicularis had the most asymmetrical and C. urticifolius the most symmetrical karyotypes. An increase in genome size was accompanied by increasing karyotype diversity in terms of morphologically distinct chromosome types and interchromosomal asymmetry, with uneven distribution of additional DNA throughout the karyotype. A positive correlation between interchromosomal asymmetry and dispersion index suggested that size differences between chromosomes were mainly associated with karyotype asymmetry. Karyotypes of the Corchorus species became progressively asymmetrical in the course of evolution. Relationships among the ten Corchorus species were defined by using a neighbor-joining tree inferred from inter-simple sequence repeat data. C. fascicularis and C. pseudocapsularis, with shorter karyotypes and smaller genomes, were closely related to C. pseudo-olitorius and C. capsularis, respectively, which were characterized by relatively longer karyotypes and larger genomes. However, the two cultivated species with different levels of interchromosomal asymmetries, dispersion indices and genome sizes were distantly related. Taking this molecular evidence into consideration, we have discussed chromosomal evolution in relation to karyological data including genome size.  相似文献   

Cytotoxicity of Senecio in macrophages is mediated via its induction of oxidative stress     

Samiran Bandyopadhyay  Goutam Mandal  Piu Saha  Mihir Sarkar 《Research in veterinary science》2009,87(1):85-90

In Arunachal Pradesh and other sub-Himalayan areas of India, accidental consumption of Senecio plants by yaks is often fatal as the plant contains toxic alkaloids like Seneciophylline. The present investigation was undertaken to demonstrate the pro-oxidant effects of an ethanolic extract of Seneciochrysanthemoides (S-EtOH). S-EtOH impaired viability in macrophages, the IC₅₀ being 13.8 ± 1.11 μg/mL. The effect of S-EtOH (1 μg/mL) on generation of reactive oxygen species (ROS) in macrophages was measured by flow cytometry using 2′,7′-dichlorofluorescein diacetate (H₂DCFDA) where it caused a significant increase in the mean fluorescence channel (MFC) from 8.55 ± 0.03 to 47.32 ± 2.25 (p < 0.001). S-EtOH also effected a 3.8-fold increase in extracellular nitric oxide (NO) generation from 4.90 ± 0.72 μM to 18.79 ± 0.32 μM (p < 0.001), a 2.2-fold increase in intracellular NO production, the MFC increasing from 14.95 ± 0.48 to 33.34 ± 1.66 (p < 0.001), and concomitantly depleted non protein thiols as analyzed by flow cytometry using mercury orange, with a reduction in MFC from 632.5 ± 49.44 to 407.4 ± 12.61 (p < 0.01). Additionally, S-EtOH (14 μg/mL, 24 h) caused apoptosis as evident by increased Annexin V binding and terminal deoxynucleotidyl transferase mediated dUTP DNA nick end labeling. Taken together, the cytotoxicity of S-EtOH can be partly attributed to its capacity to inflict oxidative damage via generation of both reactive oxygen and nitrogen species culminating in apoptosis.  相似文献   

Initial screening studies on potential of high phenolic-linked plant clonal systems for nitrate removal in cold latitudes   总被引：1，自引：0，他引：1  

Derong Lin  Lijiang Hu  Hong You  Dipayan Sarkar  Baoshan Xing  Kalidas Shetty 《Journal of Soils and Sediments》2010,10(5):923-932

Purpose  

Nitrate removal is a major challenge in drinking water systems and is more acute in colder latitudes due to low metabolic conversion rates of biological systems. To achieve rapid nitrate removal, designed plant systems in greenhouse microenvironments has potential. In such localized controlled microenvironments, higher temperatures can be managed for plant growth in an appropriate growth medium through which nitrate-contaminated water is fed for denitrification.  相似文献   

Prioritizing areas for conservation and vegetation restoration in post-agricultural landscapes: A Biosphere Reserve plan for Bioko, Equatorial Guinea     

Noelia Zafra-Calvo  Rowena Cerro  Jorge M. Lobo  Sahotra Sarkar 《Biological conservation》2010,143(3):787-794

Although the conversion of natural vegetation to agriculture threatens biodiversity, post-agricultural lands may provide an opportunity to preserve biodiversity if they are allowed to regenerate. We develop a framework for incorporating abandoned agricultural fields into the design of a Biosphere Reserve using former cocoa plantations on Bioko, Equatorial Guinea, as a case study. First, we used BIOCLIM to model the potential distribution of 62 ferns, 327 monocotyledons, 749 dicotyledons, seven primates, and 104 birds on Bioko. Next, we quantitatively assessed the representation of these distributions in conservation areas proposed by the Equatoguinean administration (hereafter “EPAs”). In addition, we used an area prioritization algorithm implemented in the ResNet software package to select an initial set of sites to serve as the Biosphere Reserve’s core areas, that is, intact forest in Bioko’s montane regions. Then, to augment the beta-diversity of the Reserve, we used the area prioritization algorithm to prioritize buffer zones in lowland sites including rainforest remnants and abandoned plantations that have partially regenerated to forest. We also compared the representation of biodiversity in the EPAs to its representation in Biosphere Reserves designed with ResNet. The representation of vegetation types and species in Reserves selected by ResNet that occupy 25% of the land on Bioko is equivalent to the representation achieved by the EPAs, which would cover 42% of Bioko. To conclude, we propose a conservation plan for Bioko.  相似文献   

Effect of Organic and Inorganic Nutrients for Soil Quality Conservation and Yield of Rainfed Low Land Rice in Sub-tropical Plateau Region     

P. Banik  P. K. Ghosal  T. K. Sasmal  S. Bhattacharya  B. K. Sarkar  D. K. Bagchi 《Journal of Agronomy and Crop Science》2006,192(5):331-343

The effect of organic sources of nutrients and inorganic fertilizers, was studied on grain yield of lowland rice and some aspect of soil quality parameters in a field experiment at Agricultural Experimental Farm of Indian Statistical Institute, Giridih, situated at eastern plateau region of India, during consecutive years 1997–2002. Chemical fertilizers and various organic matters were applied to two rice cultivars, Sabita and Subarna. The highest mean grain yield was 3.53 t ha^?1 and maximum agronomic efficiency was 60.3 % with the application of inorganic fertilizer followed by cow dung, where 3.47 t ha^?1 grain yield was recorded with an agronomic efficiency of 57.5 %. Grain yield of rice recorded under organic sources of nutrients was not significantly different from that of inorganic fertilization though there was improvement in soil quality parameters under organic sources. Soil organic carbon (0.72 %), microbial biomass‐C (279.23 μg g^?1 dry soil), urease activity with buffer (33.54 μg urea hydrolyzed g^?1 oven‐dry soil) and non‐buffer (21.97 μg urea hydrolyzed g^?1 of oven‐dry soil) methods and acid phosphatase activity (2.24 μg para‐nitrophenol released g^?1 of oven‐dry soil) analysed following the harvest of the crop were highest under cow dung manure treatment; the most efficient organic source under the experiment. Mean grain yield of rice was significantly higher in Sabita cultivar over Subarna. The regression analyses among the variables have shown that there was linear relationship among soil parameters and grain yield of rice.  相似文献   

Wet-only and bulk deposition studies at New Delhi (India)     

Kulshrestha  U. C.  Sarkar  A. K.  Srivastava  S. S.  Parashar  D. C. 《Water, air, and soil pollution》1995,85(4):2137-2142

Water, Air, & Soil Pollution - Rain water samples were collected at New Delhi during the monsoon of 1994 at a height of 30 m above the ground level using a wet-only collector. Simultaneously,...  相似文献   

A study on short-time sampling of individual rain events at New Delhi during monsoon, 1994     

U. C. Kulshrestha  A. K. Sarkar  S. S. Srivastava  D. C. Parashar 《Water, air, and soil pollution》1995,85(4):2143-2148

Rain water samples of equal volume (50 mL) were collected from two couvective showers at New Delhi on 28 July and 23 August during the monsoon, 1994. The variation of constituents of both the showers showed different trends which might have been due to different antecedent periods. The first shower occurred after an antecedent period of 2–3 hours while the second shower occurred after a 14 day interval. The first shower had acidic pH (<5.6) and relatively higher concentration of NH₄, SO₄, NO₃, Cl, F and K indicating insignificant below cloud scavenging. The second shower had alkaline pH (>5.6) and relatively higher concentrations of Ca and Mg. The higher concentration of Ca and Mg in the second shower were due to the loading with particulate matter during the preceding 14 days which made below cloud scavenging significant.  相似文献