Variation among macroinvertebrate communities suggests the importance of conserving desert springs          下载免费PDF全文

Keara Stanislawczyk  Ashley D. Walters  Tara J. Haan  Makiri Sei  David J. Berg 《水产资源保护:海洋与淡水生态系统》2018,28(4):944-953

Detection of Trypanosoma congolense antibodies with indirect ELISAs using antigen-precoated microtitre plates     

Rebeski DE  Winger EM  Okoro H  Kowalik S  Bürger HJ  Walters DE  Robinson MM  Dwinger RH  Crowther JR 《Veterinary parasitology》2000,89(3):187-198

The study reports the performance of four indirect enzyme-linked immunosorbent assays (ELISAs) for antibody (AB) detection using microtitre plates which were precoated with native or heat/detergent denatured antigens (AGs) from Trypanosoma congolense (T.c.) and T. vivax (T.v.), and stored for between 1 to 206 days at +37 degrees C. Bovine serum samples were obtained by sequential bleeding of 3-months old T.c.-infected bulls and their uninfected cohorts, as well as by a single bleeding of uninfected adult cattle. The first day of AB detection, and observations on samples after this (defined as estimated ELISA sensitivity), depended on the cut-off value in the specific ELISAs. Cut-off values from pre- and early post-infection samples of individual animals demonstrated a seroconversion in all ELISAs on average after 10-15 days post-infection (dpi). The AB detection was delayed in the T.c. native and denatured AG-based ELISAs using cut-off points from uninfected cohort cattle (16.5 dpi, 19.3 dpi) and the adult cattle population (22.1 dpi, 25.0 dpi). The T.v. AG-based ELISAs however lacked crossreactiviy to T.c. ABs. The estimated sensitivity of each T.c. AG-based ELISA was above 96% throughout, but significantly lower for the T.c. native AG-based ELISA (91.1%) when the adult cattle derived cut-off point was used (p<0.01). The sensitivity of the phase contrast buffy coat technique was similar to the T.c. AG-based ELISAs, but significantly lower when the T.c. denatured AG-based ELISA was used at the adult cattle derived cut-off point (p<0.05). The implications of the results and future research aspects on ELISAs to detect trypanosomal ABs and AGs are discussed.  相似文献   

Potassium phosphate induces systemic protection in barley to powdery mildew infection     

Mitchell AF  Walters DR 《Pest management science》2004,60(2):126-134

In laboratory tests, treatment of the first leaves of barley (Hordeum vulgare L cv Golden Promise) with potassium phosphate led to significant reduction in infection of the second leaves with the powdery mildew fungus Blumeria graminis f sp hordei Marchal, with a 25 mM treatment giving 89% reduction in infection. Although the optimal interval between phosphate treatment of the first leaves and mildew inoculation of the second leaves was 2 days, significant protection was still obtained if the interval was increased to 12 days. Protection against powdery mildew infection was not as effective when the potassium phosphate was applied as a seed treatment or root drench. Phosphate treatment of the first leaves led to significant increases in activities of phenylalanine ammonia lyase (PAL), peroxidase and lipoxygenase in second leaves. Enzyme activities, especially PAL and peroxidase, were increased further when second leaves of phosphate-treated plants were inoculated with powdery mildew. Phosphate treatment of the first leaves did not adversely affect plant growth and, in a field trial, 25 mM potassium phosphate provided 70% control of mildew and gave a small increase in grain yield.  相似文献   

Synthesis and antifungal activity of five classes of diamines     

Ross WF  Walters DR  Robins DJ 《Pest management science》2004,60(2):143-148

Examples of five classes of diamines were synthesized and tested for antifungal activity. Two classes, the bis(cyclohexylmethyl)diamines and the bis(benzyl)diamines, were most effective in reducing mycelial growth of the oat leaf stripe pathogen Pyrenophora avenae Ito & Kuribay when used at a concentration of 250microM. The bis(benzyl)diamine BBD5 and the hydroxypyridylethylamine HPE2 both reduced powdery mildew infection of barley seedlings by greater than 70% when applied as a post-inoculation spray at 250 microM. Several of the compounds examined, and especially BBD5 and HPE2, reduced the formation of spermidine but greatly increased spermine levels. These changes in P avenae treated with BBD5 and HPE2 were also accompanied by greatly elevated activity of polyamine oxidase. It is suggested that the antifungal activity of these compounds may be related to the accumulation of spermine and specifically to its toxicity.  相似文献   

Antibiotic growth promoters     

Mudd AJ  Walters J 《The Veterinary record》2003,153(10):308

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Eugenol reduces growth and increases activity of S-adenosylmethionine decarboxylase in the phytopathogenic fungusBotrytis fabae     

S. K. Oxenham  K. P. Svoboda  D. R. Walters 《Phytoparasitica》2005,33(3):247-252

This study was undertaken to examine the possibility that eugenol-induced reductions in growth ofBotrytis fabae are associated with alterations in polyamine metabolism.B. fabae was grown in liquid medium amended with different concentrations of eugenol. Changes in fungal biomass, and activities of enzymes of polyamine biosynthesis and catabolism were studied. An examination was also made of the incorporation of radioactivity from ornithine into polyamines. Activity of the polyamine biosynthetic enzyme S-adenosylmethionine decarboxylase (AdoMetDC) and flux of label from ornithine into the polyamine spermine were greatly increased inB. fabae grown in the presence of eugenol. However, no significant changes were observed in polyamine catabolism or in the concentrations of free polyamines in treated fungal tissue. http://www.phytoparasitica.org posting May 17, 2005.  相似文献   

Reproductive Performance of Ewes after 5-Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F₂α     

AB Dixon  M Knights  JL Pate  PE Lewis  EK Inskeep 《Reproduction in domestic animals》2006,41(2):142-148

Three experiments were conducted with a total of 1579 ewes to examine reproductive performance in response to synchronization of oestrus during the breeding season, using controlled internal drug releasing (CIDR-G) inserts in regimens designed to provide high concentrations of circulating progesterone. In experiment 1, treatment with two CIDR-G inserts for 12 days produced conception rate (79%) and prolificacy (1.9) to first service equivalent to breeding at natural oestrus (56% and 2.0, respectively). Pregnancy rates to two service periods were 90 and 79%, respectively. In experiments 2 and 3, progesterone was delivered by a single CIDR-G insert for 5 days in combination with prostaglandin F2alpha (PGF2alpha; 5 mg i.m., twice, 3 h apart) the day before (experiment 2), or at insert removal (experiment 3). The combined treatments improved rates of synchronization of oestrus (p<0.01) by 23 and 20% points, respectively, and pregnancy rates to the first service period by 19 (p<0.05) and 13 (p<0.01) percentage points, respectively, compared to treatment with PGF2alpha alone. It is concluded that the combination of treatment for 5 days with a CIDR-G insert and two injections of 5 mg PGF2alpha, the day before, or the day of insert removal, were effective treatments to obtain high fertility at synchronized oestrus in ewes during the breeding season.  相似文献   

Sorghum ergot (Claviceps africana) associated with agalactia and feed refusal in pigs and dairy cattle     

Blaney BJ  McKenzie RA  Walters JR  Taylor LF  Bewg WS  Ryley MJ  Maryam R 《Australian veterinary journal》2000,78(2):102-107

OBJECTIVE: To establish the aetiology and define the main clinical features of a syndrome characterised by severe feed refusal, death of piglets and reduced milk production in pigs and dairy cattle. DESIGN: Clinical, pathological, toxicological and epidemiological examination of clinical cases in 10 piggeries and 4 dairies, located between 50 and 150 km south-west of Rockhampton. RESULTS: All cases were associated with the feeding of sorghum grain infected with sorghum ergot (Claviceps africana). There was mild to severe feed refusal when the sorghum was first offered. Sows fed ergot before farrowing had shrunken udders, produced no colostrum, and displayed signs of oestrus. All of their piglets died, apparently from starvation: necropsy of a few piglets showed that they were born alive and walked, but had ingested no milk. Sows fed the grain after farrowing had severe reductions in milk production despite aggressive sucking by piglets, leading to very poor growth of piglets. There were no signs of infectious disease. Ergot in sorghum samples ranged from 1 to 31% ergot sclerotes by weight. Total alkaloid concentrations in mixed feeds ranged from 5 to 40 mg/kg, with dihydroergosine accounting for approximately 90%. At the same time, in the same districts, there were reports of feed refusal and reduced milk production from 4 dairy farms. Grain samples from these farms contained up to 17% C africana ergot sclerotia. CONCLUSION: Agalactia and feed refusal are classical signs of poisoning by rye ergot (C purpurea), but this is the first time that sorghum ergot has been associated with a similar syndrome.  相似文献   

Bovine citrullinaemia traced to the sire of Linmack Kriss King   总被引：1，自引：0，他引：1  

PJ HEALY  JA DENNIS  LM CAMILLERI  JL ROBINSON  AL STELL  RD SHANKS 《Australian veterinary journal》1991,68(4):155-155

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A study of the growth of the alimentary tract of the young cockerel.     

D W Crompton  D E Walters 《British poultry science》1979,20(2):149-158

1. The growth of the alimentary tract of male domestic fowl has been described from measurements of the dry weight of the whole and component parts of the tract from hatching to 10 weeks of age. 2. Quadratic regression equations were derived to express the growth of the birds and the growth of their alimentary tracts. 3. From hatching to 2 weeks there were marked alterations in the proportions which the different parts represented of the size of the whole tract.  相似文献