排序方式： 共有12条查询结果，搜索用时 15 毫秒
1.
Parishmita Handique Hemanta Pokhrel Binod Kalita Raktim Sarmah Abdul Malik Ahmed Kaustabh Bhagawati Arnab Narayan Patowary 《Aquaculture Research》2020,51(5):1973-1979
The present study was conducted to evaluate the …effect of dietary selenium on growth performance and antioxidant enzymes activity in Cirrhinus mrigala for a period of 45 days. Four numbers of experimental diets were prepared, Tc for Control (0 mg organic selenium/kg of diet), T1 (2.5 mg organic selenium/kg of diet), T2 (5.0 mg organic selenium/kg of diet) and T3 (10 mg organic selenium/kg of diet). The water quality parameters (temperature, DO, pH, conductivity, hardness, ammonia, nitrate and nitrite) were found to be insignificant (p > .05) among all the treatments. Superoxidase dismutase (SOD) was found to be significantly highest in T2 (6.10 ± 0.07) when compared with the other treatments. Similarly, catalase (CAT) activity in T1 (13.21 ± 0.13) was significantly (p < .05) different with that of Control, T2 and T3. Present study also revealed that 2.5mg organic selenium/kg supplemented diet (T1) showed highest results in net weight gain (15.55 ± 1.36 g), net weight gain percentage (185.88 ± 8.98%) and SGR (2.35 ± 0.06 g) compared with other experimental diet. 相似文献
2.
Bhattacharyya J Banerjee H Bhattacharyya A 《Journal of agricultural and food chemistry》2003,51(14):4013-4016
Fenazaquin (I) is a new acaricide of the quinazoline class. The photodecomposition of I was studied in aqueous methanolic and 2-propanolic solution under UV light (30 h) and sunlight (70 h) separately. The photolytic half-lives in aqueous methanolic solution were found to be 17.1 h (UV) and 38.1 h (sunlight), whereas these were 12.9 h (UV) and 29.2 h (sunlight) for aqueous 2-propanolic solution; all followed a first-order reaction kinetics. Six photoproducts were obtained: beta-phenyl (p-tert-butyl) ethyl alcohol (II), 4-hydroxyquinazoline (III), p-tert-butyl vinyl benzene (IV), 2,4-dihydroxyquinazoline (V), phenyl (p-tert-butyl) acetic acid (VI), and 2-methyl-2-[4'-(2' '-hydroxyethyl)phenyl]propanoic acid (VII). Compounds VI and VII could be isolated only from aqueous 2-propanolic solution under sunlight irradiation. The major degradation products are formed as a result of cleavage of the ether bridge linking the quinazoline and phenyl ring systems of the molecule, oxidation of the tert-butyl substituent, and oxidation of the heterocyclic portion of the quinazoline ring. A probable mechanism of formation of the photoproducts is also suggested. 相似文献
3.
Ramesh Chandra Malick Asit Kumar Bera Hemanta Chowdhury Manojit Bhattacharya Tanuja Abdulla Himanshu Sekhar Swain Raju Baitha Vikas Kumar Basanta Kumar Das 《Aquaculture Research》2020,51(6):2410-2420
The disease outbreaks in aquaculture system of wetlands are the major cause of fish mortality. Among various bacterial septicaemic diseases, fish mortality caused by Acinetobacter spp. is recently reported in different fish species. Fish disease outbreak was investigated in a wetland of West Bengal, India to identify the aetiological factors involved. The moribund fish were examined and subjected to bacterial isolation. Two bacterial causative agents were identified as Acinetobacter junii and Acinetobacter pittii by biochemical characterization and 16S rRNA gene amplification. Both the isolates were oxidase‐negative, nitrate‐negative, catalase‐positive and indole‐negative. The molecular identification using 16S rRNA gene sequencing and phylogenetic tree analysis further confirmed the two Acinetobacter spp. with 97%–99% similarity. The antibiotic resistance patterns of these two bacteria revealed that both of them were resistant to β‐lactam, cefalexin, cephalothin, amoxyclav, cefuroxime, cefadroxil, clindamycin, vancomycin and penicillin. In addition, A. pittii was also resistant to other antibiotics of cephams group such as ceftazidime and cefotaxime. In the challenge experiment, both A. junii and A. pittii were found to be pathogenic with LD50 of 1.24 × 105 and 1.88 × 107 cfu/fish respectively. Histopathological examination of gill, liver and kidney revealed prominent changes supporting bacterial septicaemia. The investigation reports for the first time on concurrent infection by A. junii and multidrug‐resistant (MDR)‐A. pittii as emerging fish pathogens to cause severe mortality in Labeo catla and Hypophthalmichthys molitrix in a freshwater wetland. 相似文献
4.
T. Boopathi S. B. Singh T. Manju Y. Ramakrishna R. S. Akoijam Samik Chowdhury N. Hemanta Singh S. V. Ngachan 《Journal of insect science (Online)》2015,15(1)
The most destructive enemy of the lychee, Litchi chinensis Sonn. (Sapindales: Sapindaceae), in India is a stink bug, Tessaratoma papillosa (Drury) (Hemiptera: Tessaratomidae). The population of T. papillosa on lychee trees varied from 1.43 ± 0.501 to 9.85 ± 3.924 insects per branch in this study. An increase in the temperature and a decrease in the relative humidity during summer months (April to July) favor the population buildup of T. papillosa. A forecasting model to predict T. papillosa incidences in lychee orchards was developed using the autoregressive integrated moving average (ARIMA) model of time-series analysis. The best-fit model for the T. papillosa incidence was ARIMA (1,1), where the P-value was significant at 0.01. The highest T. papillosa incidences were predicted for April in 2010, January in 2011, May in 2012, and February in 2013. A model based on time series offers longer-term forecasting. The forecasting model, ARIMA (1,1), developed in this study will predict T. papillosa incidences in advance, thus providing functional guidelines for effective planning of timely prevention and control measures. 相似文献
5.
Raktim Sarmah Sarada Kanta Bhagabati Rajdeep Dutta Dipanka Nath Hemanta Pokhrel Lawonu P. Mudoi Nishi Sarmah Jiten Sarma Abdul M. Ahmed Rupam Jyoti Nath Lucy Ingtipi Kedolhouse Kuotsu 《Aquaculture Research》2020,51(9):3839-3846
The synthetic antioxidant 3,5‐di‐tert‐butyl‐4‐hydroxytoluene (BHT) is widely used as an additive in the food, cosmetic and plastic industries to increase the tenability of food and plastic for the past 70 years. BHT is degraded to 3,5‐di‐test‐butyl‐4‐hydroxybenzaldehyde (BHT‐CHO) in mammals, as well as in the natural environment such as in river and water. The average daily intake of BHT for human being is estimated to be 0.3 mg/kg body weight. Even though it is considered safe for human at authorized level, but its ubiquitous presence in the aquatic environment and the controversial toxicological data are of great concern for human as well as aquatic life. The experimental findings of zebrafish embryo toxicity test (ZFET) showed that the acute toxicity of 96‐hr (LC50) exposure during the embryogenic stage was found to be 4.388 mg/L and the effective concentration (EC50) was 1.375 mg/L. The reduce heart rate from the sublethal concentrations indicates the chemical to be cardiotoxic but a further review is to be needed. The Teratogenic Index (TI) calculated to be 3.19, which implies the compound may be a potential teratogen in aquatic life. The findings obtained in this study will stretch more evidence regarding developmental toxicity of BHT, which will be of much importance in further risk assessment of ecotoxicological studies. 相似文献
6.
A two-level three-factor (23) full factorial design was conducted to observe the parameters influencing arsenic removal from an aqueous solution using iron oxide-coated A. niger biomass. The factors taken into consideration were the mass of the adsorbent, the concentration of arsenic in solution and the solution temperature. It was observed that the mass of the adsorbent and the solution temperature had positive effects on arsenic removal efficiency. Arsenic concentration in the solution had a negative effect. This meant that the higher the solution concentration, the lower the As removal efficiency. The effect of temperature was more pronounced in As(III) removal (26.6%) compared to that of As(V) removal (14.4%). The effect of mass of adsorbent was observed to be higher in the case of As(V) removal (30.7%) compared to that of As(III) removal (25.5%). 相似文献
7.
Khulape Sagar A. Maity Hemanta Kumar Pathak Dinesh Chandra Ramamurthy Narayan Ramakrishnan Saravanan Chellappa Madhan Mohan Dey Sohini 《Tropical animal health and production》2019,51(8):2529-2538
Tropical Animal Health and Production - The low potency of genetic immunization has to date impeded development of commercial vaccines against major infectious diseases. The aim of this study was... 相似文献
8.
Nivedita Sur Srikumar Pal Hemanta Banerjee Narayan Adityachaudhury Anjan Bhattacharyya 《Pest management science》2000,56(3):289-292
The photodegradation of aqueous alcoholic solutions of fenarimol at λ ≥ 250 nm has been examined. UV irradiation of an aqueous methanolic solution for 24 h yielded two photoproducts, identified as 2,4′‐dichlorobenzil and p‐chlorobenzoic acid, while irradiation of a solution in aqueous isopropanol yielded p‐chlorobenzoic acid and two additional products identified as 2,4′‐dichlorobenzophenone and o‐chlorobenzoic acid. A mechanism for the formation of the photoproducts is suggested. © 2000 Society of Chemical Industry 相似文献
9.
Parthenium hysterophorus is a noxious invasive weed of both agricultural and natural ecosystems, spreading aggressively in Nepal. Management of this weed in Nepal has been limited, mainly because of the lack of geo‐referenced data concerning the weed's distribution. We conducted a nationwide survey of P. hysterophorus and its coleopteran biological control agent Zygogramma bicolorata from 2013 to 2016 to determine their spatial distribution. Both were widespread, with the distribution of Z. bicolorata lagging behind the invasion front of P. hysterophorus. The weed was present in 21.2% of the 4838 locations examined, including several isolated satellite populations. The weed was found in the Tarai, Siwalik, Middle Mountains and High Mountains regions, reaching up to 2000 m asl. It has invaded natural and modified ecosystems including all six protected areas in the Tarai and Siwalik regions. Road access appears to be the major pathway for its long‐distance dispersal. Zygogramma bicolorata had spread from the east to the west and was present in 15.4% of the weed occurrence locations, inflicting a low amount of damage. A CLIMEX modelling projection revealed the presence of additional geographic areas in Nepal which are climatically suitable for both P. hysterophorus and Z. bicolorata. Eradication of satellite populations of the weed by physical and chemical measures, and the release of Z. bicolorata into new, but climatically suitable, locations should be prioritised for P. hysterophorus management in Nepal. In conclusion, P. hysterophorus has rapidly become widespread in Nepal and the currently available biological control agent has not been able to prevent further spread of the weed. 相似文献
10.
Against the backdrop of viewing marketing intermediaries in developing countries as parasites, this study examined the validity of such a view, especially in the context of mandarin (a species of orange) marketing in a mountain district of Nepal. Necessary information was collected from all major stakeholders such as farmers, collectors and commission agents, and the relative position of farmers in terms of their gains was analyzed by employing three criteria: price of mandarin, marketing margin and income distribution. Income distribution among marketing functionaries “with” and “without” transaction cost has been analyzed. Similarly, marketing margin and farmers’ share of gross income are also analyzed ‘with’ and ‘without’ the cost of malicious practices by marketing intermediaries. Findings of the study revealed that farmers in the study area are receiving a fair share of the benefit accruing from the marketing of mandarin. However, taking advantage of their weak bargaining power and poor economic condition, marketing intermediaries are harassing and cheating them in different ways. Policy recommendations are made to institutionalize and strengthen the group-marketing system to address such inherent problems. 相似文献