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71.
Myosin V is a dimeric molecular motor that moves processively on actin, with the center of mass moving approximately 37 nanometers for each adenosine triphosphate hydrolyzed. We have labeled myosin V with a single fluorophore at different positions in the light-chain domain and measured the step size with a standard deviation of <1.5 nanometers, with 0.5-second temporal resolution, and observation times of minutes. The step size alternates between 37 + 2x nm and 37 - 2x, where x is the distance along the direction of motion between the dye and the midpoint between the two heads. These results strongly support a hand-over-hand model of motility, not an inchworm model.  相似文献   
72.
The aim of this study was to examine the coagulation profile in peste des petits ruminant (PPR) in kids. Five kids from a group of 150 animals (72 goats and 78 kids) were brought to the Veterinary Medical Teaching Hospital from a farm in Burdur province (Turkey) with nasal and ocular discharges and diarrhea. Fifteen goats and 41 kids had died due to diarrhea and three kids were presented to the Department of Pathology for diagnosis. Blood samples were taken from 12 ill animals (infected group) for haematological and biochemical analysis. In addition, five healthy kids were examined from another healthy flock (control group). Leukocyte and lymphocyte numbers of infected group showed significant declinations in comparison to control group (≤0.001). Haemorrhages in all organs of digestive system and small haemorrhagic areas in liver were caused to decrease in erythrocyte and haematocrit values (p ≤ 0.001) in infected group. Concentrations of blood urea nitrogen (BUN) (p ≤ 0.01) and creatinine (p ≤ 0.001) in infected group were significantly higher than control group. Compared to control group, significant increases were determined in serum concentrations of alkaline phosphatase (ALP) (p ≤ 0.01), aspartate aminotransferase (AST) (p ≤ 0.001) and alanine aminotransferase (ALT) (p ≤ 0.001) in the infected group. No significant differences were observed between the infected and control groups for serum gamma glutamyl-transferase (GGT) concentration value. In our study, thrombocytopenia (p ≤ 0.001) together with prolonged activated partial thromboplastin time (APTT; p ≤ 0.01) and prothrombin time (PT; p ≤ 0.001) may show that disseminated intravascular coagulopathy which can occur in kids with PPR.  相似文献   
73.
Arcobacter cryaerophilus was isolated from naturally infected rainbow trout (Oncorhynchus mykiss Walbaum), and its pathogenicity was tested by intramuscular injection into 40 healthy 1-year-old rainbow trout at 16 degrees C. The lethal dosage of 50% end point (LD50) for A. cryaerophilus was calculated 2.25 x 10(4) viable cells. Experimental infection caused deaths with gross clinical abnormalities such as degenerated opercula and gills, liver damage, haemorrhagic kidney and serous fluid in swollen intestines. The counts of A. cryaerophilus in kidney, liver and gills of experimentally infected fish ranged from 1.59 x 10(10) colony forming units (cfu)/g to 7.41 x 10(12) cfu/g. The means of erythrocyte (RBC) count, haematocrit level, serum cholesterol, triglyceride, albumin and total protein concentrations in the blood of the experimentally infected rainbow trout group were significantly lower than in the healthy fish. Leukocyte (WBC) counts of the experimentally infected rainbow trout were significantly higher than those of healthy fish. The present work shows that the selected blood characteristics may be good indicators of response to infections in rainbow trout.  相似文献   
74.
This study was conducted to assess the role of increasing N supply in enrichment of whole grain and grain fractions, particularly the endosperm, with Zn and Fe in wheat. The endosperm is the most widely consumed part of wheat grain in many countries. Plants were grown in the greenhouse with different soil applications of N and Zn and with or without foliar Zn spray. Whole grain and grain fractions were analyzed for N, P, Zn and Fe. Increased N supply significantly enhanced the Zn and Fe concentrations in all grain fractions. In the case of high Zn supply, increasing N application enhanced the whole grain Zn concentration by up to 50% and the endosperm Zn by over 80%. Depending on foliar Zn supply, high N elevated the endosperm Fe concentration up to 100%. High N also generally decreased the P/Zn and P/Fe molar ratios in whole grain and endosperm. The results demonstrate that improved N nutrition, especially when combined with foliar Zn treatment, is effective in increasing Zn and Fe of the whole grain and particularly the endosperm fraction, at least in the greenhouse, and might be a promising strategy for tackling micronutrient deficiencies in countries where white flour is extensively consumed.  相似文献   
75.
Cortisol and finfish welfare   总被引:1,自引:0,他引:1  
Previous reviews of stress, and the stress hormone cortisol, in fish have focussed on physiology, due to interest in impacts on aquaculture production. Here, we discuss cortisol in relation to fish welfare. Cortisol is a readily measured component of the primary (neuroendocrine) stress response and is relevant to fish welfare as it affects physiological and brain functions and modifies behaviour. However, we argue that cortisol has little value if welfare is viewed purely from a functional (or behavioural) perspective—the cortisol response itself is a natural, adaptive response and is not predictive of coping as downstream impacts on function and behaviour are dose-, time- and context-dependent and not predictable. Nevertheless, we argue that welfare should be considered in terms of mental health and feelings, and that stress in relation to welfare should be viewed as psychological, rather than physiological. We contend that cortisol can be used (with caution) as a tractable indicator of how fish perceive (and feel about) their environment, psychological stress and feelings in fish. Cortisol responses are directly triggered by the brain and fish studies do indicate cortisol responses to psychological stressors, i.e., those with no direct physicochemical action. We discuss the practicalities of using cortisol to ask the fish themselves how they feel about husbandry practices and the culture environment. Single time point measurements of cortisol are of little value in assessing the stress level of fish as studies need to account for diurnal and seasonal variations, and environmental and genetic factors. Areas in need of greater clarity for the use of cortisol as an indicator of fish feelings are the separation of (physiological) stress from (psychological) distress, the separation of chronic stress from acclimation, and the interactions between feelings, cortisol, mood and behaviour.  相似文献   
76.
Increasing zinc (Zn) concentration of cereal grains is a global challenge to alleviate Zn deficiency‐related health problems in humans caused by low dietary Zn intake. This study investigated the effects of soil‐ and foliar‐applied nitrogen (N) and Zn fertilizers on grain Zn accumulation of durum wheat (Triticum durum) grown on a Zn‐deficient soil. In addition, localization of Zn and protein within durum wheat grain was studied by using Bradford reagent for protein and dithizone (diphenyl thiocarbazone) for Zn. Grain Zn concentration was greatly enhanced by soil or foliar applications of Zn. When Zn supply was adequately high, both soil and foliar N applications improved grain Zn concentration. Consequently, there was a significant positive correlation between grain concentrations of Zn and N, when Zn supply was not limiting. Protein and Zn staining studies showed co‐localization of Zn and protein within grain, particularly in the embryo and aleurone. Results indicate that N and Zn fertilization have a synergistic effect on grain Zn concentration. Possibly, increasing N supply contributes to grain Zn concentration by affecting the levels of Zn‐chelating nitrogenous compounds or the abundance of Zn transporters. Our results suggest that nitrogen management can be an effective agronomic tool to improve grain Zn concentration.  相似文献   
77.
Changes of plasma lysozyme and serum bactericidal activity, ceruloplasmin, total plasma protein, serum glucose, hematocrit and leucocrit levels in rainbow trout (Oncorhynchus mykiss) were studied after exposure to formalin and chloramine-T, which are used in aquaculture as anti-ectoparasitic and antibacterial agents. Fish were exposed to formalin at a concentration of 250 ppm for 60 min and exposed to chloramine-T for 5 ppm for 3 h. The parameters were analyzed for rainbow trout exposed to formalin and chloramine-T soon after treatments and rainbow trout exposed to freshwater after 24 h (return) following the treatments. Plasma lysozyme activity decreased after exposure to formalin; however, it was not affected by chloramine-T exposure. Serum bactericidal activity reduced after both formalin and chloramine-T exposure and did not change after returning to freshwater. Ceruloplasmin and total plasma protein were not affected by both treatments. Serum glucose levels of exposed fish elevated and remained at higher levels during recovery period when compared to control values. Hematocrit values of fish exposed to formalin increased; however, no significant change was observed in fish exposed to chloramine-T. Leucocrit levels of fish treated with both formalin and chloramine-T were higher than that of controls.  相似文献   
78.
Macrophomina phaseolina and Rhizoctonia spp. are the most important soilborne pathogens of the strawberry crop that cause seriously reduced yields. Various methods are being used to determine pathogenicity of these fungi isolated from strawberry; however, they take a long time to grow strawberry plants. They also encounter some problems to provide a large number of healthy plants for the pathogenicity tests. Therefore, the aim of this study was to develop a faster and more reliable pathogenicity test for soilborne fungal pathogens of strawberry by using the stolons of healthy strawberry plants. The stolon inoculation method was demonstrated to be easy and rapid for properly distinguishing soilborne fungal species of strawberry, whether pathogenic or non-pathogenic, and also for assessing the isolates for virulence.  相似文献   
79.
The effects of plant growth promoting bacteria (PGPB) on the fruit yield, growth and nutrient element content of strawberry cv. Fern were investigated under organic growing conditions between 2006 and 2008. The experimental plot was a completely randomized design with 3 replicates. Three PGPB strains (Pseudomonas BA-8, Bacillus OSU-142 and Bacillus M-3) were used alone or in combination as bio-fertilizer agent in the experiment. Data through 3 years showed that the use of PGPB significantly increased fruit yield, plant growth and leaf P and Zn contents. Root inoculation of M3 and floral and foliar spraying of OSU-142 and BA-8 bacteria stimulated plant growth resulting in significant yield increases. M3 + BA-8, BA-8 + OSU-142, M3, M3 + OSU-142 and BA-8 applications increased cumulative yield by 33.2%, 18.4%, 18.2%, 15.3% and 10.5%, respectively. Number of fruits per plant significantly increased by the applications of M3 + BA-8 (91.73) and M3 (81.58) compared with the control (68.66). In addition, P and Zn contents of strawberry leaves with bacterial inoculation significantly increased under organic growing conditions. Available P contents in soil were increased from 0.35 kg P2O5/da at the beginning of the study to 2.00, 1.97 and 1.82 kg P2O5/da by M3 + OSU-142, M3 + BA-8 and M3 + BA-8 + OSU-142 applications, respectively. Overall, the results of this study suggest that root inoculation of Bacillus M3 alone or in combination with spraying Bacillus OSU-142 or Pseudomonas BA-8 have the potential to increase the yield, growth and nutrition content of strawberry plant under organic growing conditions.  相似文献   
80.
The aim of this study was to explore the feasibility of cryopreservation of inter‐subspecies cloned embryos in buffalo. In our experiment, river buffalo ear fibroblast nucleus was fused into swamp buffalo oocyte cytoplasm. The blastocyst formation rate for nuclear transfer of freshly thawed cells was not different from those of growing cells, confluent or serum‐starved cells. A total of 122 cloned blastocysts derived from cryopreserved fibroblasts were cryopreserved and thawed, 37 were survived, the cryosurvival rate was 30.3%. The survived blastocysts were transferred into 15 recipient buffalos. Five of the recipients established pregnancy, but four of them aborted on day 53, 59, 145 and 179 of gestation respectively. One cross‐bred buffalo (Murrah × Swamp buffalo (2n = 49) received three embryos delivered a 40.5 kg female calf by natural delivery on day 320 of gestation. Up to now (13‐month old), the cloned calf has been growing well with no abnormity observed. These results demonstrated that cryopreservation of inter‐subspecies cloned embryos is feasible to produce buffalo offspring.  相似文献   
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