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排序方式: 共有228条查询结果,搜索用时 337 毫秒
191.
SM Majharul Islam Rabaya Sultana Mohammad Imran Mst. Fatema Tuj Jannat Mohammad Ashaf‐Ud‐Doulah Md. Fazle Rohani Christopher Brown Md. Shahjahan 《Aquaculture Research》2020,51(10):4361-4371
Temperature is considered as an important environmental factor, and the increasing water temperature resulting from global warming is a great concern. The present study was conducted to examine the effects of elevated water temperature on growth, hemato‐biochemical parameters in Nile tilapia, Oreochromis niloticus acclimatized to three temperatures (31°C, 34°C and 37°C) for 60 days. Additionally, erythrocytic cellular abnormalities (ECA) and erythrocytic nuclear abnormalities (ENA) tests were assayed using peripheral erythrocytes after exposure to the three temperatures. Fish were sacrificed on days 7, 15, 30 and 60 of exposure. Growth performances viz., weight gain, % weight gain and specific growth rate (SGR) showed decreasing tendency at 34°C but significantly declined at 37°C compared to 31°C. The abundance of haemoglobin (Hb) and red blood cells (RBCs) significantly decreased in response to temperature increases, while white blood cells (WBCs) displayed the opposite response. At days 7 and 15, blood glucose levels significantly increased in response to the temperature increase, while at days 30 and 60 glucose declined. Frequencies of ECA and ENA were significantly enhanced at the highest temperature throughout the experimental period. Dissolved oxygen decreased and free CO2 increased significantly with increasing temperature throughout the study period. The present study revealed that temperatures higher than 34°C may be hazardous to O. niloticus. 相似文献
192.
L Voss J Huaman C Pacioni A Tolpinrud K Helbig TG Carvalho SM Firestone 《Australian veterinary journal》2023,101(3):106-114
Coxiella burnetii causes significant reproduction losses in livestock and the disease Q fever in humans. Transmission of C. burnetii is facilitated by the stability of the bacterium in the environment and the susceptibility of a variety of host species to infection. Consequently, inter-species transmission occurs frequently through either direct or indirect contact. Wildlife may represent reservoirs of C. burnetii and could therefore be a source of infection for domestic animals. Understanding the prevalence of C. burnetii infections at the wildlife-livestock interface is important for disease control. This study aimed to investigate the extent of C. burnetii exposure in wild deer in eastern Australia. Serum samples were obtained from 413 wild deer from seven regions in four eastern Australian states from 2017 to 2020. Antibodies were detected using a commercial Q fever antibody kit validated for ruminants. Seroprevalence of C. burnetii antibodies in deer was determined and true prevalence estimated, for each region. The overall seroprevalence of C. burnetii antibodies in wild deer was 3.4% (14 seropositive of 413 deer sampled) with true prevalence estimated to be 4.3% (95% credible interval: 0.6%, 10.9%). Seropositive deer were identified only in Queensland (7/108 seropositive) and northern New South Wales (7/120 seropositive). This geospatial distribution is consistent with seropositivity in other animal species and indicative of the level of C. burnetii in the environment. The low seroprevalence suggests that wild deer are unlikely to be a major reservoir species for C. burnetii in eastern Australia but may still be implicated in inter-species transmission cycles. 相似文献
193.
L Lotz T Hauenstein SM Nichols‐Burns P Strissel I Hoffmann S Findeklee R Dittrich MW Beckmann PG Oppelt 《Reproduction in domestic animals》2015,50(6):958-964
The goal of this study was to compare a traditional slow‐freeze method (TF) with an open unidirectional slow freeze cooling system (UF) for whole ovary cryopreservation. Therefore, whole pig ovaries were randomly assigned to (A) fresh control, (B) traditional slow freeze (TF) or (C) unidirectional slow freeze (UF). Ovaries were perfused with 10% DMSO in Krebs‐Ringer. For TF, whole ovaries were placed in specimen jars containing 10% DMSO and placed into a specialized container for freezing filled with propan‐2‐ol. For UF, whole ovaries were placed within a specially designed container containing 10% DMSO and transferred to a specialized freezing machine (CTE 920). Histological evaluation demonstrated intact morphology of follicles in all groups; however, an overall decrease of follicle numbers in TF (46%) and UF (50%) compared to fresh control. Live/dead assay indicated significantly lower populations of live cells in both TF (60%) and UF (58%) compared to fresh tissue (74%). TUNEL assay confirmed a difference in percentage of apoptotic follicles between fresh and TF, but there was no significant difference between fresh and UF. To improve the structural and functional integrity of whole ovaries, further investigation, especially into directional freezing, is needed. Whole ovary cryopreservation could provide opportunities for women facing fertility loss due to chemo‐ or radiotherapy treatment. 相似文献
194.
T. M. Middleton 《Wood Science and Technology》1989,23(4):299-302
Summary The problem of vessel length determination in hardwood trees has been approached in many ways by various workers. The paint infusion technique was utilized in a research programme investigating the subject of vessels of New Zealand beech (Nothofagus) stem sapwood. Two different models of stainless steel paint applicator were used: (a) the horizontal T shaped applicator and (b) the new vertical Y joint applicator. Applicator construction is discussed. The techniques are modifications of the Zimmermann and Jeje (1981) latex paint infuction method.The author gratefully acknowledges Dr. B. G. Butterfield, Dr. B. A. Meylan and L. A. Donaldson for advice and Dr. L. M. H. Middleton for field assistance 相似文献
195.
Summary An electron microscope study of the behaviour of Dacrydium cupressinum Lamb. (rimu), Podocarpus dacrydioides A. Rich, (kahikatea) and Pinus radiata D. Don. (radiata pine); two endemic timbers of New Zealand and one exotic timber coated with a specially formulated TiO2 tagged long soya oil alkyd coating was made using both the scanning and transmission electron microscopes. The key elements present in the coating were detected by energy dispersive X-ray analysis and used to qualitatively trace coating penetration into wood. Quantitative information on the nature of the coating penetration was obtained by photographing the entire cross-sectional length of each weatherboard under the scanning electron microscope and counting the number of filled cells inwards from the coating interface. The performance of the coating and the three weatherboard taxa were tested using accelerated weathering techniques involving the Xenon-arc Weather-Ometer. Coated and uncoated boards were weathered for up to three thousand hours. Coating durability and substrate behaviour were qualitatively assessed microscopically. Fourier transform infrared and attenuated total reflectance methods were used to obtain quantitative information on coating performance and particular reference is made to these latter techniques.The author gratefully acknowledges Dr. B. G. Butterfield, Dr. L. M. H. Middleton, and the University Grants Committee for awarding the U.G.C. scholarship to carry out the research 相似文献
196.
197.
Studies were conducted to examine the possibility of preserving slaughterhouse‐derived buffalo ovaries at 4°C for 0 (control), 12 and 24 h to maintain the developmental competence of the oocytes (experiment 1), to assess the effect of incubation temperature during oocyte maturation on rates of in vitro maturation (IVM) and in vitro fertilization (IVF) of buffalo oocytes and embryo development (experiment 2), and to examine the effect of storage at 25°C for 0 (control), 4 and 8 h of frozen–thawed buffalo sperm and BO and H‐TALP as sperm processing and fertilization media on cleavage and embryo development in vitro of buffalo oocytes (experiment 3) in order to optimize the IVF technology in buffalo. Results suggested that storage of ovaries at 4°C for 12 or 24 h significantly (p < 0.05) reduced the developmental potential of oocytes. Incubation temperatures during the IVM influenced the fertilization rate but had no significant effect on maturation and subsequent embryo development. The incubation temperature of 38.5°C during IVM was found to be optimum for embryo production in vitro. Storage of frozen–thawed sperm at 25°C for 8 h significantly (p < 0.05) decreased its ability to cleave the oocytes. Sperm processed in BO medium had significantly (p < 0.05) higher ability to cleave the oocytes than the H‐TALP medium. 相似文献
198.
199.
200.
A 12‐year‐old 450 kg Argentine polo mare presented with a dropped elbow and an unwillingness to bear weight after being kicked by another horse on the lateral aspect of the upper left forelimb. The mare was subsequently diagnosed with a displaced olecranon fracture that did not readily conform to the standard classification systems. Referral for surgical treatment involving open reduction and internal fixation was declined due to financial constraints. Due to the mare being unsuitable for breeding, and conservative treatment of displaced olecranon fractures being deemed to have an overall poor prognosis for return to full athletic performance, another treatment option was sought. Given the fracture configuration, standing surgical removal of the large proximal fragment was performed. The mare returned to full athletic performance 12 months post operatively without lameness. This case report describes an alternative treatment option for selected olecranon fractures. 相似文献