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61.
62.
The fish-seed production industry in India has recorded remarkable growth over the last three decades. The hypophysation technique
was successfully introduced into India in 1957 and steady progress towards the refinement of the technique has been registered,
which has revolutionized carp seed production in the Indian subcontinent. Advancement of carp maturity through brood stock
management and multiple breeding has enabled spawn production well ahead of the monsoon and even beyond, ensuring seed availability
throughout the year. The quality of seed is an important consideration for commercial aquaculturists. So, partial stock replenishment
in carp hatcheries is practised to overcome the problem of inbreeding, which otherwise leads to poor growth of carps. Similarly,
gametes of improved stock are cryopreserved and utilized for quality seed production as well as upgrading the brood stock
of carps. The gamete cryopreservation protocol for carps is the focus of this review. An attempt has also been made to incorporate
information on carp brood stock management, inducing agents, and seed production, including hatchery management. 相似文献
63.
Soils are the third biggest sink of carbon on the earth. Hence, suitable land uses for a climatic condition are expected to sequester optimum atmospheric carbon in soils. But, information on how climatic conditions and land uses influence carbon accumulation in the soils on the Himalayan Mountains is not known. This study reports the impact of four climatic conditions (sub-tropical, altitude: 500–1200 m; temperate 1200–2000 m; lower alpine 2000–3000 m; upper alpine, 3000–3500 m) and four land uses (forest, grassland, horticulture, agriculture) on the concentrations and stocks of soil organic carbon (SOC) in upper (0–30 cm) and deeper (30–100 cm) soil depths on the western Himalayan Mountains of India. The study also explored the drivers which influenced the SOC stock build up on the mountains. Rainfall and soil moisture showed quadratic relations, whereas temperature declined linearly with the altitude. SOC stock as well as concentration was the highest (101.8 Mg ha− 1 in 0–30 cm, 227.97 Mg ha− 1 in 0–100 cm) in temperate and the lowest in sub-tropical climate (37 Mg ha− 1 in 0–30 cm, 107.04 Mg ha− 1 in 0–100 cm). Pattern of SOC stock build up across the altitude was: temperate > lower alpine > upper alpine > sub-tropical. SOC stocks in all land uses across the climatic conditions, except agriculture in lower alpine, was higher (0.7 to 41.6%) in the deeper than upper soil depth. SOC stocks in both the depths showed quadratic relations with soil temperature and soil moisture. Other factors like fine soil particles, land-use factor and altitude influenced positively whereas slope and pH, negatively to the SOC stocks. In all climatic conditions, other than temperate, SOC stocks were greater in natural ecosystems like forests and pastures (112.5 to 247.5 Mg ha− 1) than agriculture (63 to 120.4 Mg ha− 1). In temperate climate, SOC stock in agriculture (253.6 Mg ha− 1) on well formed terraces was a little higher than forest (231.3 Mg ha− 1) on natural slope. These observations, suggest that land uses on temperate climate may be treated as potential sinks for sequestration of the atmospheric carbon. However, agriculture in subtropical climate need to be pursued with due SOC protection measures like the temperate climate for greater sequestration of the atmospheric carbon. 相似文献
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65.
Samraat Pawar Chris Kelley Sujoy Chaudhuri Sahotra Sarkar 《Biological conservation》2007,136(3):346-361
This study combines niche modeling and systematic area prioritization using distribution data for 131 species of amphibians and reptiles from Northeast India and Burma, with two objectives: (i) to evaluate the performance of the current conservation area network in Northeast India with respect to the representation of amphibians and reptiles, and (ii) to identify potential areas for expanding the current conservation area network. In a two-step protocol, maximum entropy niche modeling was used to project species’ potential geographic occurrences, and the resulting probabilistic distribution data were used to prioritize areas with algorithms that maximize the representation of all species in minimal total area. The results provided a critical assessment of conservation priorities in this data-deficient region, and indicate the utility of combining niche modeling with systematic area prioritization in such situations. Many areas that had been overlooked in previous assessments were identified. Although the existing protected areas were found to be inadequate for representation of amphibian and reptile diversity, the prioritization results show that by targeting a minimal representation of 5% of the current total area suitable for each species, the gaps can be filled with a relatively modest (0.41%) increase in the current total area covered by the network. Extended analyses were also performed to assess the effects of putatively rare species on reserve selection, which showed that the inclusion of these taxa can change the prioritization solutions significantly. The prioritization results also highlight areas of Northeast India that warrant attention from future surveys. 相似文献
66.
S. Sarkar 《Archives of Agronomy and Soil Science》2013,59(3):339-346
Abstract To increase the water use efficiency (WUE) of rice, two sets of experiments were carried out from 1997 – 1999. Experiment one: Irrigation period of rice was divided into three stages: early (S1, 10 – 35 days after transplanting, [DAT]); middle (S2, 36 – 60 DAT) and late (S3, 61 – 85 DAT). Intermittent ponding (IP) was imposed at single, two stages or the entire growing period. Continuous ponding (CP) in all three stages was taken as control. Though the highest grain yield (6.71 mg ha?1) was obtained under control, this regime was responsible for the lowest WUE. In contrast, IP in all stages was responsible for maximum WUE with minimum yield level. Imposition of IP in S1 resulted in higher (0.529 kg m?3) WUE along with insignificant reduction in yield over control. Experiment two: Three puddling practices were: (i) High intensity puddling (HIP); (ii) Moderate intensity puddling (MIP); and (iii) Low intensity puddling (LIP). On average, HIP resulted in the lowest value (6.5 mm d?1) of percolation rate. Both grain yield (6.93 mg ha?1) and WUE (0.597 kg m?3) attained highest value under HIP. A decrease in puddling intensity under MIP and LIP lowered the yield by 2.97 and 17.75% respectively. In the case of WUE, the reduction was 16.27 and 54.66%. 相似文献
67.
R. Yadav K. Mohan V. Kumar M. Sarkar K. Nitu H.H.D. Meyer B.S. Prakash 《Domestic animal endocrinology》2013
A highly sensitive enzyme immunoassay (EIA) that used the second antibody coating technique and the cortisol-horseradish peroxidase conjugate as a label for determination of free and total cortisol in blood plasma of dairy animals (cows, buffaloes, and goats) was developed. For biological validation of the EIA, blood samples were collected from the animals at 48 and 24 h before and 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, and 132 h after dexamethasone administration. The EIA was performed directly with 20 μL of fresh plasma (for free cortisol) and also with 20 μL of heat-treated plasma (for total cortisol) after 1:5 dilutions with PBS. Cortisol standards ranging from 0.39 to 200 pg/well/20 μL were used, and the sensitivity of the EIA procedure was found to be 0.39 pg/well/20 μL, which corresponded to 0.02 ng/mL. In comparison with RIA the EIA was at least 4 times more sensitive and required 5 times less cortisol antiserum. In female cattle, buffaloes, and goats, the total, free, and bound plasma cortisol before dexamethasone administration was significantly (P < 0.05) higher than the total, free, and bound cortisol after dexamethasone administration. It can be concluded from these studies that the direct, sensitive EIA validated for estimating the free and total cortisol concentrations was sufficiently reliable and quick for studying the dynamics of cortisol distribution in blood plasma of dairy animals. 相似文献
68.
Masahiro Hosono Shigeki Sugawara Takeo Tatsuta Toshiyuki Hikita Junko Kominami Sachiko Nakamura-Tsuruta Jun Hirabayashi Sarkar M. A. Kawsar Yasuhiro Ozeki Sen-itiroh Hakomori Kazuo Nitta 《Fish physiology and biochemistry》2013,39(6):1619-1630
Osmerus (Spirinchus) lanceolatus egg lectin (OLL) is a member of the rhamnose-binding lectin (RBL) family which is mainly found in aqueous beings. cDNA of OLL was cloned, and its genomic architecture was revealed. The deduced amino acid (aa) sequence indicated that OLL was composed of 213 aa including 95 aa of domain N and 97 aa of domain C. N and C showed 73 % sequence identity and contained both -ANYGR- and -DPC-KYL-peptide motifs which are conserved in most of the RBL carbohydrate recognition domains. The calculated molecular mass of mature OLL was 20,852, consistent with the result, and 20,677.716, from mass spectrometry. OLL was encoded by eight exons: exons 1 and 2 for a signal peptide; exons 3–5 and 6–8 for N- and C-domains, respectively. Surface plasmon resonance spectrometric analyses revealed that OLL showed comparable affinity for Galα- and β-linkages, whereas Silurus asotus lectin (SAL), a catfish RBL, bound preferentially to α-linkages of neoglycoproteins. The Kd values of OLL and SAL against globotriaosylceramide (Gb3) were 1.69 × 10?5 M for and 2.81 × 10?6 M, respectively. Thus, the carbohydrate recognition property of OLL is slightly different from that of SAL. On the other hand, frontal affinity chromatography revealed that both OLL and SAL interacted with only glycolipid-type oligosaccharides such as Gb3 trisaccharides, not with N-linked oligosaccharides. The domain composition of these RBLs and an analytical environment such as the “cluster effect” of a ligand might influence the binding between RBL and sugar chains. 相似文献
69.
B. S. Bhau K. Medhi T. Sarkar S. P. Saikia 《Genetic Resources and Crop Evolution》2009,56(8):1183-1193
Nepenthes khasiana Hook. f. belonging to monotypic family Nepenthaceae is a rare, endangered, dioecious member of the carnivorous plant found
in North-East India. The plant is endemic to the Indian state of Meghalaya and is distributed throughout the state from West
Khasi hills to East Khasi hills, Jaintia hills and East, West to South Garo hills from 1,000 to ca. 1,500 m altitude. Multi-locus
analysis using PCR based Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeats (ISSR) markers were used
for the first time to assess the genetic diversities of N. khasiana Hook. f. collected from different parts of Meghalaya. It was observed that RAPD analysis showed more polymorphism than ISSR
fingerprinting in revealing genetic polymorphism in N. khasiana Hook. f. The result of cluster analysis by using UPGMA method showed that the groups based on pooled RAPD–ISSR genetic similarity
were more similar than the groups based on RAPD. Furthermore, genetic similarity reveals variability within the population
at Jarain of Jaintia hills, while between populations the Baghmara region differs from the others with at least 40% dissimilarity.
The results show a broad range of genetic diversity within the populations of N. khasiana Hook. f. 相似文献
70.