Semen biology of vendace (<Emphasis Type="Italic">Coregonus albula</Emphasis> L.)     

Grzegorz J. Dietrich  Mariola Dietrich  Piotr Hliwa  Robert Stabinski  Joanna Nynca  Aneta Andronowska  Andrzej Ciereszko 《Fish physiology and biochemistry》2010,36(3):419-425

The objective of this study was to describe the morphometry and motility parameters of vendace (Coregonus albula) spermatozoa. Morphometric parameters of vendace sperm head and tail were of values similar to rainbow trout. The effects of pH, sodium, potassium and calcium ion concentrations on computer-assisted sperm analysis (CASA) sperm motility characteristics were tested. Vendace sperm was motile in a wide pH range of 6.0–10.5 with the optimum pH established at 9.0. Increases in potassium and calcium ions caused decreases in the percentage of motile sperm. The CASA parameters and erratic sperm movement pattern of vendace spermatozoa were similar to whitefish (C. lavaretus) sperm motility, suggesting that there is a coregonid-specific sperm motility pattern.  相似文献   

Effect of breed of cattle on transmission rate and innate resistance to infection with Babesia bovis and B bigemina transmitted by Boophilus microplus     

RE BOCK  TG KINGSTON  AJ de  VOS 《Australian veterinary journal》1999,77(7):461-464

OBJECTIVE: To assess the effect of breed of cattle on the transmission rates of and innate resistance to Babesia bovis and B bigemina parasites transmitted by Boophilus microplus ticks. DESIGN: Groups of 56 purebred B indicus and 52 B indicus cross B taurus (50%, F1 generation) steers were placed in a paddock seeded with and also naturally infested with B microplus which were the progeny of females ticks fed on B taurus cattle specifically infected with a virulent isolate of B bovis. The cattle were placed in the infested paddock 50 days after seeding had started. PROCEDURE: Cattle were inspected from horseback daily for 50 days. Clinically ill cattle were brought to yards and assessed by monitoring fever, depression of packed-cell volume, parasitaemia and severity of clinical signs. Any animals that met preset criteria were treated for babesiosis. Blood samples were collected from all cattle on day 28, 35 and 42 after exposure and antibodies to Babesia spp and packed cell volume measured. RESULTS: All steers, except for one crossbred, seroconverted to B bovis and B bigemina by day 35 and 75% of the crossbred steers showed a maximum depression in packed cell volume of more than 15% due to infection with Babesia spp compared with only 36% of the B indicus group. Ten of the 52 crossbreds and 1 of the 56 B indicus steers showed severe clinical signs. Two of the crossbreds required treatment of which one died 2 weeks after initial treatment. CONCLUSIONS: Pure-bred B indicus cattle have a high degree of resistance to babesiosis, but crossbred cattle are sufficiently susceptible to warrant the use of preventive measures such as vaccination. Transmission rates of B bovis and B bigemina to B indicus and crossbred cattle previously unexposed to B microplus were the same.  相似文献   

水分胁迫下4种冷季型草坪草抗旱性比较研究   总被引：1，自引：0，他引：1  

初晓辉  岳信龙  任健  陈功  单贵莲 《草原与草坪》2012,32(4):15-19

采用盆栽育苗法,研究了4种冷季型草坪草在不同水分胁迫下的抗旱性,结果表明:1)随着水分胁迫程度的加深,4种冷季型草坪草的外观质量和叶片相对含水量显著下降,细胞质膜透性、MDA含量和Pro含量上升。2)模糊数学综合评价结果表明,4种冷季型草坪草种抗旱性能由强到弱的顺序为:高羊茅>多年生黑麦草>草地早熟禾>匍匐翦股颖。  相似文献   

Magnetic Collapse in Transition Metal Oxides at High Pressure: Implications for the Earth     

RE Cohen  II Mazin  DG Isaak 《Science (New York, N.Y.)》1997,275(5300):654-657

Magnetic collapse in transition metal ions is predicted from first-principles computations at pressures reached in the Earth's lower mantle and core. Magnetic collapse would lead to marked changes in geophysically important properties, such as elasticity and conductivity, and also to different geochemical behavior, such as element partitioning, than estimated by extrapolating low-pressure data, and thus change the understanding of Earth's structure and evolution. Magnetic collapse results from band widening rather than from changes in crystal field splitting under pressure. Seismic anomalies in the outer core and the lowermost mantle may be due to magnetic collapse of ferrous iron, dissolved in iron liquid in the outer core, and in solution in magnesiowustite in the lowermost mantle.  相似文献   

Rib osteomyelitis in three foals     

KM Neil  RE Charman  JR Vasey 《Australian veterinary journal》2010,88(3):96-100

Three foals aged between 21 and 44 days were presented for evaluation of pyrexia and lameness. Each had subcutaneous abscessation associated with osteomyelitis of a rib at the costochondral junction and pathological fracture of the affected rib; one foal had more than one rib affected. Other localised sites of infection included other sites of osteomyelitis, omphalophlebitis, uveitis, enterocolitis, and calcaneal bursitis. The subcutaneous abscessation and rib osteomyelitis was treated surgically in two foals. Salmonella typhimurium was isolated from the subcutaneous abscess in one foal and from the faeces of another. Two of the three foals were euthanased. Ultrasonography was a more useful modality than radiography for establishing the diagnosis of costal osteomyelitis.  相似文献   

Effect of Oxygen Saturation in Water on Reproductive Performances of Pacu Piaractus brachypomus     

Konrad  Dabrowski Jacques  Rinchard Joseph S.  Ottobre Fernando  Alcantara Palmira  Padilla Andrzej  Ciereszko Marcos J.  De Jesus Christopher C.  Kohler 《Journal of the World Aquaculture Society》2003,34(4):441-449

Broodstock pacu Piaractus brachypomus as well as their eggs during their embryonic development were exposed to either normoxia (5.5–7.5 mg O₂/L) or hypoxia (2.0–4.5 mg O²/L) conditions. The plasma concentrations of 11-ketotestosterone in males and estradiol-17β in females, as well as that of their precursor testosterone (T) were significantly ( P < 0.01) higher in fish maintained under normoxic conditions than in fish exposed to hypoxia. After ovulation and spermiation induced by hormonal treatments, the plasma concentrations of T and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) significantly ( P 0.05) increased in both sexes under both normoxic and hypoxic conditions. The plasma levels of T and 17,20βP achieved under normoxic conditions were higher than the ones recorded under hypoxia, except for those of 17,20βP in males. Males responded positively to the hormonal treatments, and the concentration of spermatozoa was 10.5 ± 0.8 10⁹/mL under both oxygen conditions. Hypoxia resulted in significantly lower survival of embryos (17.3 ± 28%) in comparison to normoxic conditions (68.5 ± 25%). Moreover, larval deformities were found when exposed to hypoxia (91.6 ± 6%). During embryonic development of this species 4 mg/L of oxygen is tolerated at 26–27 C without negative impact. We conclude that despite the highly adaptable nature of adult pacu to environmental hypoxia, oxygen concentrations below 4 mg/L severely impacted survival of embryos.  相似文献   

Laryngeal paralysis in a Rottweiler with neuroaxonal dystrophy     

PF BENNNETT  RE CLARKE 《Australian veterinary journal》1997,75(11):784-786

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Alternative and Complementary Veterinary Medicine: A Holistic View of Functional Medicine.     

RE Clarke 《Australian veterinary journal》2001,79(11):777-777

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Cutaneous lymphosarcoma in a sugar glider     

I. HOUGH  RE REUTER  RS RAHALEY  C. BELFORD  R. MILLER  G. MITCHELL 《Australian veterinary journal》1992,69(4):93-94

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Laser-Doppler Measurements of Spinal Cord Blood Flow Changes During Hemilaminectomy in Chondrodystrophic Dogs with Disk Extrusion     

YASMINDA MALIK  DVM    DAVID SPRENG  DVM  Diplomate ECVS & ACVECC    MARTIN KONAR  DVM  Diplomate ECVDI    MARCUS G. DOHERR  DVM  PhD  Diplomate ECVPH    RE JAGGY  PhD  Diplomate ECVN    JUDITH HOWARD  DVM  Diplomate ACVIM    FRANCK FORTERRE  DVM  Diplomate ECVS 《Veterinary surgery : VS》2009,38(4):457-462

Objectives— (1) To assess spinal cord blood flow (SCBF) during surgical treatment of disk extrusion in dogs and (2) to investigate associations between SCBF, clinical signs, presurgical MRI images, and 24-hour surgical outcome.
Study Design— Cohort study.
Animals— Chondrodystrophic dogs with thoracolumbar disk extrusion (n=12).
Methods— Diagnosis was based on clinical signs and MRI findings, and confirmed at surgery. Regional SCBF was measured intraoperatively by laser-Doppler flowmetry before, immediately after surgical spinal cord decompression, and after 15 minutes of lavaging the lesion. Care was taken to ensure a standardized surgical procedure to minimize factors that could influence measurement readings.
Results— A significant increase in intraoperative SCBF was found in all dogs (Wilcoxon's signed-rank test; P =.05) immediately after spinal cord decompression and after 15 minutes. Changes in SCBF were not associated with duration of clinical signs; initial or 24-hour neurologic status; or degree of spinal cord compression assessed by MRI.
Conclusion— SCBF increases immediately after spinal cord decompression in dogs with disk herniation; however, increased SCBF was not associated with a diminished 24-hour neurologic status.
Clinical Relevance— An increase in SCBF does not appear to be either associated with the degree of spinal cord compression or of a magnitude sufficient to outweigh the benefit of surgical decompression by resulting in clinically relevant changes in 24-hour outcome.  相似文献