棉花组织培养高效植株再生体系的建立   总被引：12，自引：2，他引：12  

刘方  张宝红 《棉花学报》2004,16(2):117-122

通过对影响棉花体细胞胚胎发生和植株再生关键因素的研究,建立了适用于广泛基因型的棉花组织培养高效胚胎发生与植株再生体系。从中棉所12、中棉所19、泗棉3号等20余个主栽品种诱导获得了胚胎发生和植株再生,有效地突破了棉花组织培养植株再生的基因型控制,使占我国棉田面积50%以上的品种均能诱导获得胚胎发生和再生植株。首次诱导获得直接胚胎发生,使棉花组织培养的周期由180d缩短到120d左右,减少了培养过程中变异的发生。该结果的获得必将大大促进植物细胞工程和基因工程在棉花遗传改良上的应用。  相似文献   

A conceptual production model for freshwater crayfish pond culture incorporating detrital forage     

B D Mitchell  T Anderson  S S De  Silva  R O Collins  J R Chavez  P L Jones  C M Austin 《Aquaculture Research》1995,26(2):117-127

A production model is presented for semi-intensive freshwater crayfish culture ponds incorporating detrital forage. The conceptual model is developed from five submodels of trophic-dynamic interactions within the pond ecosystem. The model includes microbially enhanced detrital forage (MEDF) produced from plant matter grown in the pond as a significant component of nutrition. The model is proposed as an aid to understanding pond-based aquaculture techniques that rely upon manipulating the characteristics of MEDF. The significance of MEDF as a source of nutrition in aquaculture is discussed.  相似文献   

Effect of dietary supplements on cytokine gene expression in rainbow trout, Oncorhynchus mykiss (Walbaum)     

Awad E  Mitchell WJ  Austin B 《Journal of fish diseases》2011,34(8):629-634

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Gear restrictions create conservation and fisheries trade-offs for management     

Paul G. Carvalho  Austin Humphries 《Fish and Fisheries》2022,23(1):183-194

Gear-based management for coral reef fisheries is often overlooked in the scientific literature. Empirical studies have demonstrated the conservation benefits of gear-restricted areas (i.e. prohibiting fishing gears), which can support greater biomass than unrestricted areas and protect species that play key functional roles. However, population dynamics of functional feeding groups of reef fishes under specific gear-restriction regimes remains uncertain. Here, we constructed a multi-species, length-based fisheries model to observe relative biomass and catch of reef fishes under various gear-restriction management scenarios. We used fishery-dependent and fishery-independent data to determine the catchability of functional groups and selectivity of size classes for hook-and-line, net and spear fishing, which are widely used gear types on coral reefs globally. Our model revealed trade-offs involved with gear-restriction management such that no single management strategy was able to maximize biomass or catch of all functional groups simultaneously. Also, we found that spear fishing (i.e. prohibiting hook-and-line and net fishing) maintained the highest total biomass summed across functional groups, whilst hook-and-line fishing (i.e. prohibiting net and spear fishing) and a ban on spears maintained the lowest biomass. However, hook-and-line fishing generated the highest catch-per-unit-effort. Our model results were primarily driven by differential growth rates, maximum per capita production of recruits, and catchability of functional groups targeted by each fishing gear. We demonstrate that gear restrictions can be a critical management tool for maintaining biomass and catch of certain functional groups but will likely require additional management to protect all key functional feeding groups of coral reef fishes.  相似文献   

The role of procaine in adverse reactions to procaine penicillin in horses     

CB CHAPMAN  P COURAGE  IL NIELSEN†  BR SITARAM  PJ HUNTINGTON‡ 《Australian veterinary journal》1992,69(6):129-133

Procaine penicillin is a commonly used antibiotic in equine medicine but its use is associated with a substantial incidence of adverse reactions. Soluble procaine concentrations were determined by HPLC in several commercially available procaine penicillin preparations, including some that were involved in adverse reactions. The mean (+/- SEM) soluble procaine concentrations in the veterinary preparations was 20.18 +/- 5.07 mg/ml, which was higher than the concentration in the only procaine penicillin preparation for use in humans in Australia of 7.3 mg/ml. Heating the veterinary procaine penicillin preparations to 50 degrees C for 1 day led to a significant (P less than 0.01) increase in the amount of soluble procaine. Heating to 50 degrees C for 7 days also produced a significant (P less than 0.02) increase. Soluble procaine tended to return to baseline concentrations when veterinary procaine penicillin preparations were heated to 50 degrees C for 2 days then stored for 7 days at room temperature. Administration of procaine HCl intravenously (IV) at 2, 5, and 10 mg/kg produced behavioural, locomotor and vascular reactions, which were clinically similar to those reported in adverse reactions to procaine penicillin. The more severe reactions occurred at higher doses, although different horses responded variably at the same dose. Some adverse reactions lead to recumbency but none were fatal. The blood procaine concentrations 1 min after IV administration averaged 19.0 +/- 12.6 and 25.3 +/- 16 micrograms/ml at 2.5 mg/kg and 5 mg/kg, respectively. Ten min after administration, blood procaine concentrations were significantly higher (P less than 0.001) in the 5 mg/kg group than in the 2.5 mg/kg group. Intramuscular (IM) procaine HCl at 5 mg/kg produced significantly lower (P less than 0.001) blood concentrations than similar IV doses, and, in contrast to the IV doses, the amount of procaine in the blood was significantly higher 5 and 10 min after administration than it was after 1 min. Mild excitatory reactions in 4/5 horses were noted 5 to 10 min after IM administration. Administration of diazepam 20 s before procaine HCl prevented the excitatory adverse reaction in 2/2 horses, but administration after the procaine did not influence the outcome.  相似文献   

Field comparison of the interferon-gamma assay and the intradermal tuberculin test for the diagnosis of bovine tuberculosis   总被引：13，自引：0，他引：13  

PR WOOD  LA CORNER  JS ROTHEL  C. BALDOCK†  SL JONES†  DB COUSINS§  BS McCORMICK¶  BR FRANCIS§  J. CREEPER¶  NE TWEDDLE 《Australian veterinary journal》1991,68(9):286-290

An extensive field comparison of the gamma interferon (IFN-gamma) assay and the single intradermal tuberculin test for the diagnosis of bovine tuberculosis was conducted in Australia. The specificity of the IFN-gamma assay was determined by testing more than 6000 cattle from tuberculosis-free herds and varied from 96.2% to 98.1%, depending on the cut-off point chosen to define a positive reactor. For the sensitivity trial, cattle from herds being de-populated because of bovine tuberculosis were examined with both assays. The sensitivity of the IFN-gamma assay was shown to be significantly higher than the single intradermal tuberculin test and varied from 76.8% to 93.6% depending on the method of interpretation. A maximum overall sensitivity of 95.2% was obtained by testing with the IFN-gamma and the tuberculin test in parallel. The superior sensitivity of the IFN-gamma assay and the ability to adjust the sensitivity of the system depending on the task involved, will provide the Australian Tuberculosis Eradication Campaign with a valuable additional test to enable it to accomplish its goals.  相似文献   

Follicle Wave Growth in Cattle   总被引：1，自引：0，他引：1  

M Mihm  MA Crowe  PG Knight  EJ Austin 《Reproduction in domestic animals》2002,37(4):191-200

Ovarian follicle growth in cattle culminates in the selection of a single dominant follicle which attains the ability for final maturation and ovulation once or twice during the luteal phase and at the end of the oestrous cycle, as well as during other reproductive states. This review will describe in detail the first follicle wave of the cycle leading to selection of the first wave dominant follicle, indicating the specific gonadotrophin dependencies of cohort and dominant follicles, and relating follicle fate to steroidogenesis. As a differential gonadotrophin response of growing antral follicles during the follies‐stimulating hormone (FSH) decline may determine which follicle becomes selected, first wave follicles are also characterized in relation to intrafollicular growth factors, which may modify the gonadotrophin response, such as inhibins and members of the insulin‐like growth factor (IGF) family. Subsequently, the follicular control of the transient FSH rise and decline so crucial to dominant follicle selection will be discussed. It is concluded that successful hormonal manipulation of follicle wave growth and dominant follicle selection will depend on our detailed understanding of the gonadotrophin requirements of differentiating wave follicles.  相似文献   

Factors affecting the geographic distribution of pseudorabies (Aujeszky's disease) virus infection among swine herds in Illinois     

C. C. Austin  R. M. Weigel 《Preventive veterinary medicine》1992,13(4):239-250

Data on the geographic distribution of swine herds tested for pseudorabies virus (PRV) in the state of Illinois (USA) were analyzed to determine whether the prevalence of PRV-infected herds was clustered geographically at the county level. Second-order analysis of spatial dependence indicated there was a spatial clustering of counties of high PRV prevalence rates and that this clustering was greater than the observed clustering of counties with a large number of swine herds. The clustering of county PRV prevalence rates was most apparent within a radius of 120 km (on the average, approximately two couties away). The association of county PRV prevalence rates with average herd size, geographic density of swine herds in the country and regional (within 120 km) density of PRV-infected herds was analyzed using multiple linear regression. The primary factor affecting county PRV prevalence rates was the regional PRV density, which interacted with the other model variables. For counties with a low regional density of PRV infection, county PRV prevalence rates charged little with a change in county herd density or average herd size. In contrast, for counties with a high regional density of PRV infection, PRV prevalence within a county increased with increasing average herd size and increasing geographic density of swine herds in the county. The results of the current and previous studies implicate an important role for the geographic proximity of infected herds in the spread of PRV among swine herds.  相似文献   

Limits of detection of bluetongue virus with different assay systems   总被引：1，自引：0，他引：1  

S J Wechsler  K J Austin  W C Wilson 《Journal of veterinary diagnostic investigation》1990,2(2):103-106

The sensitivity of different assay systems for detecting low concentrations of bluetongue virus (BTV) were compared. These assays included blind passage on baby hamster kidney (BHK-21) cells and on cattle pulmonary artery endothelial (CPAE) cells, immunoperoxidase staining of cells on multiwell slides, and cDNA/RNA hybridization of BTV infected cells. Nine serial 10-fold dilutions of a cell culture-adapted BTV serotype 11 were tested (each dilution was treated as a separate sample) in all assays. Visual inspection for cytopathic effects (CPE) during 3 passages in BHK-21 cells detected samples that contained greater than or equal to 3 plaque forming units (PFU)/ml of BTV. Evidence of CPE during 3 passages in CPAE cells detected samples that contained greater than or equal to 0.3 PFU/ml of BTV. A limit of detection (greater than or equal to 0.3 PFU/ml) was obtained faster by immunoperoxidase staining of BTV-inoculated CPAE cells on multiwell slides and incubated for 3 days. The cDNA/RNA hybridizations of CPAE and BHK-21 cells incubated for 2 or 3 days, respectively, with BTV dilution samples detected samples that contained greater than or equal to 30 PFU/ml. Of the assay systems examined, immunoperoxidase staining of CPAE cells on multiwell slides inoculated with cell culture-adapted BTV was the most sensitive and fastest assay for definitive virus identification.  相似文献   

Ocular protothecosis in a dog   总被引：1，自引：0，他引：1  

W W Carlton  L Austin 《Veterinary pathology》1973,10(3):274-280

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