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991.
Samuel Addo Abel A. Carrias Malachi A. Williams Mark R. Liles Jeffery S. Terhune Donald A. Davis 《Journal of the World Aquaculture Society》2017,48(2):257-267
This study was conducted to evaluate the effects of probiotic‐amended diets fed to juvenile Nile tilapia, Oreochromis niloticus, on growth and susceptibility to Streptococcus iniae infection. Fish (average weight 16.5 ± 0.2 g) were fed five diets formulated with Bacillus subtilis strains SB3086, SB3295, SB3615, or AP193 either individually or in combination of strains SB3086 and SB3615 at a targeted concentration of approximately 4 × 107 colony‐forming units (CFU)/g of feed or with a basal control diet with no additives for 21 d. After the 21‐d growth trial, no significant difference in growth performance was observed with any probiotic‐amended diet. Results from serum bactericidal activity showed a significant difference between treatments and the control (P = 0.0002), except for the SB3295‐amended diet (P = 0.9020). Lysozyme activity was also significantly different in fish fed probiotic diets from those fed control diet (P = 0.0001). After 21 d of feeding, fish were challenged with S. iniae by intraperitoneal injection at a dosage of 8 × 106 CFU per fish. Results from the challenge also showed a significant difference between treatments and control (P = 0.0001). Overall, fish fed with strain SB3615 showed the lowest percent mortality (44.0 ± 7.2%) and those fed the control diet showed the highest mortality (77.3 ± 7.0%). The combined feeding with strains SB3086 and SB3615 did not result in any significant difference in reducing mortality because of S. iniae infection in juvenile Nile tilapia when compared with the individual probiotic treatments. 相似文献
992.
R M Prouty W L Reichel L N Locke A A Belisle E Cromartie T E Kaiser T G Lamont B M Mulhern D M Swineford 《Pesticides monitoring journal》1977,11(3):134-137
Eighty-six bald eagles found sick or dead during 1973-74 in 24 States were analyzed for organochlorine compounds. DDE was detected in all caracasses; polychlorinated biphenyls (PCB's) were found in all but two. Seventy-five carcasses contained TDE and/or dieldrin. Four eagles had possibly lethal levels of dieldrin in the brain. Bald eagles continue to retain high residue levels of organochlorine pollutants. Illegal shooting remained the most common cause of death but accounted for a smaller percentage of the mortalities than in the two previous biennial collections. 相似文献
993.
A progressive, hereditary disease has been observed in Basset Hounds, which appears clinically and neuromorphologically as myoclonus epilepsy (ME) and is similar to Lafora-Glueck disease in humans. The characteristic intracellular accumulations are typical myoclonus inclusion bodies. Four forms of inclusion bodies (IB) can be distinguished: a) very small, homogeneous, PAS-positive IBs, b) IBs consisting of an accumulation of PAS-positive particles, c) IBs with a concentric internal structure and a smooth or radial outer zone, and d) IBs with a homogeneous center, concentric layering, light intermediate zone, and a smooth outer zone. The occurrence of IBs is restricted largely to nerve cells. Here they are located mainly in pericarya, to a lesser extent in dendrites, and rarely in the neurites of the peripheral nervous system. IBs are also found in samples of skeletal muscle where they lie between myofibrils or beneath the sarcolemma. They are slightly basophilic in HE-staining and markedly PAS-positive. In transmission electron micrographs IBs prove to consist of chain-like filamentous material of varying density with focal concentrations. They are similar to IBs of the brain. Both muscular and neuronal IBs lack surrounding membranes. Diagnosis of Lafora disease in dogs by examination of muscle biopsies is discussed. 相似文献
994.
Reynolds JH Hohenberg CM Lewis RS Davis PK Kaiser WA 《Science (New York, N.Y.)》1970,167(3918):545-548
Highlights of a first effort in sorting out rare gases in lunar material are solar wind rare gases in abundance; variable (20)Ne/(22)Ne but constant (21)Ne/ (22)Ne ratios in fractions of the trapped neon; cosmogenic rare gases similar to those found in meteorites, except for copious (131)Xe in one rock but not in another; at Tranquillity Base a rock 4.1 x 10(9) years old which reached the surface 35 to 65 million years ago, amid soil whose particles have typically been within a meter of the surface for 10(9) years or more. 相似文献
995.
996.
We estimated the contribution of dissolved organic matter (DOM) to cation leaching and the translocation of acidity in three acid forest soils. The analysis was based on monitored (2 years) concentrations of dissolved organic carbon (DOC) in the field, measured total acidities of DOM, and measured as well as predicted weighted mean dissociation constants of the organic acids. Although the forest floor solutions were strongly acidic (pH 3.47–4.10), a considerable proportion of the organic acids was dissociated and organic anions represented 22–40% of the total anions in the mineral soil input. The flux of DOM-associated exchangeable protons from the forest floor to the mineral soil ranged from 0.35 (Wülfersreuth) to 3.72 (Hohe Matzen) kmol ha?1 yr?1. In the subsoil, this organic acidity may be neutralized by microbial decomposition of the organic acids, but a part of the hydrogen ions may dissociate and contribute to acidification of the soil solution and to weathering processes. Due to the pronounced retention of DOM in the mineral subsoil horizons, the contribution of DOM to the output of cations and acidity from the soil is much lower than in the surface horizons but still significant.? 相似文献
997.
The ‘lutte étagée ciblée’ (LEC), a new spray programme, was tested in Burkina Faso. Each routine insecticide application at a fortnightly interval was followed by scouting and, if necessary, another application based on a threshold, 7 days later. The dosages of the active ingredients used were about half those in the previously recommended 14-day routine treatment programme. On-station trials revealed that the new programme provided the same level of pest control as the previously recommended routine programme. Similar results were obtained in smallholder field trials with yields greater than the fortnightly spraying programme used by the farmers. The amount of insecticide saved by this new programme ranged between 44% and 54%. 相似文献
998.
Special issue on evapotranspiration measurement and modeling 总被引:1,自引:1,他引:0
999.
Kaiser J 《Science (New York, N.Y.)》2006,313(5787):601-602
1000.
Kaiser J 《Science (New York, N.Y.)》2006,311(5769):1852-1854