排序方式： 共有53条查询结果，搜索用时 31 毫秒
31.
Changes in hemolymph osmolality, ion concentrations, and enzymatic activities of carbonic anhydrase (CA) in the gills and
epidermal tissue, and Na/K-ATPase in the gills during the molt cycle were investigated in the white shrimp Litopenaeus vannamei. Hemolymph osmolality was high in the intermolt and early premolt stages, but started to decrease prior to ecdysis through
to postmolt stages A and B. Changes in Na+ and Cl− ion concentrations paralleled those in hemolymph osmolality. CA activity levels in the anterior and posterior gills were
low at intermolt stage C0 and premolt stage D0, and maximum at premolt stage D3. In the epidermal tissue, activity was relatively high at intermolt stage C0 and premolt stage D0, but fluctuated towards premolt stage D3 and postmolt stage A. On the other hand, Na/K-ATPase activity in the gills decreased between intermolt stage C0 and premolt stage D2, but increased at premolt stage D3 and postmolt stage A. The changes in patterns of CA activity during the molt cycle suggest that CA may be involved in supplying
counter-ions for Na+ and Cl− uptake during molting. Branchial Na/K-ATPase appears to be involved in producing local osmotic gradients in order to support
water influx across the epithelium. 相似文献
32.
Vidya Sagar Dr Narrotam P. Sahu Dr Asim K. Pal Dr Kamal K. Jain & Dr Gundaboena Venugopal 《Aquaculture Research》2009,40(12):1383-1393
A feeding trial was conducted to study the effect of dietary protein (DP) levels on the growth and digestive enzyme activities of different wild stocks of Macrobrachium rosenbergii juveniles. Wild juveniles of M. rosenbergii were collected from the west coast of India, Gujarat (G), Maharashtra (M) and from the east coast of India, Andhra Pradesh (A), and raised in culture ponds of 200 m2 at 1 juvenile m?2. All the animals were tagged individually with Elastomer tags of a particular colour assigned to their respective stock and acclimatized for 7 days before being released into the pond at a ratio of 70:65:65 (A:M:G). Each of the two feeds, the first with 27% DP, termed the suboptimum level (S), and the second 32% DP, termed the optimum level (O), was fed in duplicate ponds at 6% of the body mass for the first 30 days and 4% for the last 30 days. The average weight of stocked prawn, respectively, in O DP and S DP fed ponds was 0.90 ± 0.04 and 1.06 ± 0.08 g for the G stock, 0.80 ± 0.07 and 1.01 ± 0.1 g for the M stock and 3.06 ± 0.13 and 3.10 ± 0.23 g for the A stock. Both the protein level and the stock type had a significant (P<0.05) effect on the weight gain% of the prawn. There was an approximate 95% change in weight gain with a DP change. Similarly, G and M stocks exhibited significantly higher (P<0.05) growth rates of approximately 90% than the A stock, although no difference was noted between the G and the M stocks. However, for protein × stock (interaction) levels, there was no significant difference (P>0.05) among the groups. Although insignificant, the survival rates among the different stocks varied from 56% to 77%. Optimum protein level showed a significant increase (P<0.05) in the specific growth rate (SGR). Feed conversion ratio, feed efficiency ratio, protein efficiency ratio and net protein utilization were not affected either due to DP, stock type or their interaction. The O × A group exhibited the maximum variation in body weight. Digestive enzyme activities were similar in all the groups, but enzymes for phospho‐monoesterase were significantly higher (P<0.05) at O DP. Both the G and the M stock showed a significantly higher (P<0.05) alkaline phosphatase activity while acid phosphatase activity was significantly higher (P<0.05) in the M stock only. Overall, the G and M stocks showed higher growth responses compared with the A stock. 相似文献
33.
34.
Jeong Kyu Bang Jun Hyuck Lee Ravichandran N. Murugan Sung Gu Lee Hackwon Do Hye Yeon Koh Hye-Eun Shim Hyun-Cheol Kim Hak Jun Kim 《Marine drugs》2013,11(6):2013-2041
Antifreeze proteins (AFPs) and glycoproteins (AFGPs), collectively called AF(G)Ps, constitute a diverse class of proteins found in various Arctic and Antarctic fish, as well as in amphibians, plants, and insects. These compounds possess the ability to inhibit the formation of ice and are therefore essential to the survival of many marine teleost fishes that routinely encounter sub-zero temperatures. Owing to this property, AF(G)Ps have potential applications in many areas such as storage of cells or tissues at low temperature, ice slurries for refrigeration systems, and food storage. In contrast to AFGPs, which are composed of repeated tripeptide units (Ala-Ala-Thr)n with minor sequence variations, AFPs possess very different primary, secondary, and tertiary structures. The isolation and purification of AFGPs is laborious, costly, and often results in mixtures, making characterization difficult. Recent structural investigations into the mechanism by which linear and cyclic AFGPs inhibit ice crystallization have led to significant progress toward the synthesis and assessment of several synthetic mimics of AFGPs. This review article will summarize synthetic AFGP mimics as well as current challenges in designing compounds capable of mimicking AFGPs. It will also cover our recent efforts in exploring whether peptoid mimics can serve as structural and functional mimics of native AFGPs. 相似文献
35.
With expanding human populations, exponentially increasing motor vehicles, and public roads running through Protected Areas, road traffic is becoming an increasing concern in many countries. While studies have traditionally examined the role of highways in fragmenting and decimating animal populations, we carried out one of the first studies of the immediate behavioural responses, rather than inferring eventual consequences, of motorists and wildlife towards each other. We inspected variables such as vehicle size, type, and origin, and elephant group composition, amongst others, to study motorist-elephant responses along highways in Mudumalai Wildlife Sanctuary, southern India. Based on 1521 motorist-elephant interactions, we found higher odds of more severe to less severe motorist response in passenger (versus goods) vehicles, visiting (versus local) vehicles, and in vehicles of particular size classes. Overall, elephant responses to vehicles increased in severity with increasing vehicle size and motorist response. Although motorists in heavy vehicles caused the least disturbance, elephants were most affected by heavy vehicles (because of their size) and generally tolerated smaller vehicles, even those that created significant disturbance. We suggest that an understanding of sensory biases of animals is important in the management of human-wildlife conflict as these could lead to the outcome of interactions being contrary to expectation. This is also one of the first uses of ordinal multinomial generalized linear models to studies of human-wildlife conflict, and we suggest its application to the data often obtained in this field. 相似文献
36.
Aralappanavar Vijay Kumar Bharti Vidya Shree Mukhopadhyay Raj Prakash Satya Harikrishna Vungarala Bhuvaneswari Govindarajan Rathi Tripathi Gayatri Krishna Gopal Sarkar Binoy 《Journal of Soils and Sediments》2022,22(2):672-681
Purpose
Similar to fresh- and brackish water aquaculture ponds, commercial shrimp farming in degraded saline areas holds the potential to bury carbon (C) in the sediments. However, studies on the mechanisms of sediment C dynamics and C-flux in response to inland saline aquaculture management practices are still scarce. Therefore, the objectives of the present study are to quantify the C burial rate in inland saline aquaculture ponds and assess the impact of inland saline aquaculture on sensitive C fractions in the bottom sediment of the ponds.
Materials and methodsThe sediment samples (n?=?12 from each pond) were collected from six shrimp farming ponds (1000 m2 area of each pond) of different ages. The sediment depth, sediment accumulation rate and the levels of total carbon (TC), total organic carbon (TOC) and sediment oxidizable organic carbon (SOC) and its different fractions were determined using standard procedures. The data were analysed by one-way analysis of variance (ANOVA), followed by the Duncan's multiple range test for comparing the means, and the Pearson correlation test was used to assess the relationship between the different pond sediment parameters and SOC content.
Results and discussionThe results revealed that the annual C accumulation rates varied from 902 to 1346 kg C ha?1 year?1 in 7-year-old earthen ponds (EPs) and bottom cemented ponds (BCPs), respectively. The sediment C fractions, including TC, TOC, SOC and its fractions (very labile, VLc; labile, Lc; less labile, LLc), and non-labile carbon (NLc)) were progressively increased over the pond age. The inland saline aquaculture practices over the years increased both active (AC) and passive carbon (PC) pools in the pond sediments, helped in the restoration and improvement of sediment quality and enhanced C sequestration potential of the sediments. Furthermore, a significant increase in the level of particulate organic carbon (POC) in BCPs justified that the non-ploughing practices at BCPs facilitated the formation of macro- and micro-aggregates, thereby increasing the C retention and stability of the pond sediments.
ConclusionThis study suggested that the shrimp farming ponds in semi-arid saline soils represented considerable C burial hotspots, enhanced the stable passive C pools and improved the sediment quality.
相似文献37.
Full genome sequence and analysis of Indian swine hepatitis E virus isolate of genotype 4 总被引：6，自引：0，他引：6
The full-length genomic sequence of an Indian swine hepatitis E virus (HEV) isolate (IND-SW-00-01) recovered from feces of a pig experimentally infected with swine HEV pool from western India was determined. The genome consisted of 7,240 nucleotides, excluding the poly (A) tail of at least 22 residues and contained three open reading frames (ORFs), ORF-1 encoding 1,707 amino acids, ORF-2 encoding 674 amino acids and ORF-3 encoding 114 amino acids. Comparative full-length genome sequence and phylogenetic analyses suggested that the Indian swine HEV represents a distinct variant among the genotype 4 isolates with a divergence of 15-16.6%. Analyses based on ORF-1, 2 and 3 as well as partial ORF-2 (227 nucleotides) yielded similar results. As compared to type 4 HEV isolates, 26 unique amino acid substitutions were recorded, 16 in ORF-1, 8 in ORF-2 and 2 in ORF-3. IND-SW-00-01 showed insertion of 'C' at 5159 position while all other type 4 isolates have insertion of 'U' at the same position. Whether these changes contribute towards observed absence of type 4 HEV infections in Indian patients needs to be determined. 相似文献
38.
P. K. Pande A. Kumar S. Ravichandran S. Naithani V. Kothiyal P. B. K. Kishore A. Raturi P. Gautam S. Dobhal S. Sharma 《林业研究》2013,24(3):485-493
We selected 28 populations of Leucaena leucocephala from different geographical locations in the states of Andhra Pradesh, Tamil Nadu and Orissa of India on the basis of height and girth at breast height (GBH). We evaluated fiber length, optical density, wall thickness, vessel element length, vessel element diameter, specific gravity and lignin of these populations of L. leucocephala in different sites. Populations had significant variations for all growth, wood and paper parameters. Girth at breast height (GBH) and specific gravity were the most important parameters for heritability and genetic gain, respectively. The minimum heritability was reported for vessel element length and genetic gain for fiber length. The populations were grouped into six clusters, cluster II had maximum number of populations (14) and clusters IV and VI had one population each. GBH contributed maximum of 34.39 % towards total divergence followed by specific gravity (14.02%). An economic technique to produce quality seed by establishing seed orchards with genetically divergent parents was suggested. The hybridization among the populations selected from diverse clusters could produce greater heterosis needed for higher growth and suitable wood and paper manufacturing parameters. 相似文献
39.
Ram JJ Padalkar RD Anuraja B Hallikeri RC Deshmanya JB Neelkanthayya G Vidya Sagar V 《Tropical animal health and production》2004,36(4):407-412
Tropical Animal Health and Production - 相似文献