Myxobolus neurotropus Infecting Rainbow Trout in Alaska,a New Geographic Record     

Collette R. Bentz  Carla I. Hogge  Theodore R. Meyers  Jayde A. Ferguson 《Journal of aquatic animal health》2013,25(4):225-231

Abstract

The Alaska Department of Fish and Game fish pathology laboratory received a rainbow trout Oncorhynchus mykiss from the Alaska Peninsula that was suspected of having whirling disease based on the display of aberrant swimming behavior and a deformed spine. We tested for Myxobolus cerebralis using standard pepsin–trypsin digest and molecular procedures, which yielded negative results. However, many oval shaped myxospores were observed in brain smears and were confirmed to be those of the morphologically similar M. neurotropus based on a diagnostic assay using PCR. The known geographic distribution of this parasite includes Idaho, Washington, Utah, Oregon, California, and now, Alaska. Whether this species is an emerging parasite is not known because it was only described a few years ago. Given the severe infection found in this rainbow trout, perhaps the considerable displacement of neurological tissues and subsequent pressure on peripheral nerves could have contributed to the spinal curvature and accompanied abnormal swimming. Conversely, the M. neurotropus infection may have been incidental and the spinal deformity may have actually been due to one of several nonspecific developmental or congenital causes. Further studies on geographic distribution and impact on host fitness will probably determine the importance of this species to fish health.

Received March 1, 2012; accepted June 15, 2012  相似文献   

Quantitative bioluminometric method for DNA-based species/varietal identification in food authenticity assessment     

Trantakis IA  Christopoulos TK  Spaniolas S  Kalaitzis P  Ioannou PC  Tucker GA 《Journal of agricultural and food chemistry》2012,60(4):912-916

A method is reported for species quantification by exploiting single-nucleotide polymorphisms (SNPs). These single-base changes in DNA are particularly useful because they enable discrimination of closely related species and/or varieties. As a model, quantitative authentication studies were performed on coffee. These involved the determination of the percentage of Arabica and Robusta species based on a SNP in the chloroplastic trnL(UAA)-trnF(GAA) intraspacer region. Following polymerase chain reaction (PCR), the Robusta-specific and Arabica-specific fragments were subjected to 15 min extension reactions by DNA polymerase using species-specific primers carrying oligo(dA) tags. Biotin was incorporated into the extended strands. The products were captured in streptavidin-coated microtiter wells and quantified by using oligo(dT)-conjugated photoprotein aequorin. Aequorin was measured within 3 s via its characteristic flash-type bioluminescent reaction that was triggered by the addition of Ca(2+). Because of the close resemblance between the two DNA fragments, during PCR one species serves as an internal standard for the other. The percentage of the total luminescence signal obtained from a certain species was linearly related to the percent content of the sample with respect to this species. The method is accurate and reproducible. The microtiter well-based assay configuration allows high sample throughput and facilitates greatly the automation.  相似文献   

Managing for Biodiversity and Livestock: A scale-dependent approach for promoting vegetation heterogeneity in western Great Plains grasslands     

Theodore P. Toombs  Justin D. Derner  David J. Augustine  Bryce Krueger  Seth Gallagher 《Herpetological Monographs》2010,32(3):10-15

  相似文献   

Antioxidative activity of protein hydrolysates prepared from alkaline-aided channel catfish protein isolates     

Theodore AE  Raghavan S  Kristinsson HG 《Journal of agricultural and food chemistry》2008,56(16):7459-7466

Antioxidative activity of hydrolyzed protein prepared from alkali-solubilized catfish protein isolates was studied. The isolates were hydrolyzed to 5, 15, and 30% degree of hydrolysis using the protease enzyme, Protamex. Hydrolyzed protein was separated into hydrolysates and soluble supernatants, and both of these fractions were studied for their metal chelating ability, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and their ability to inhibit the formation of thiobarbituric acid reactive substances (TBARS) in washed tilapia muscle containing tilapia hemolysate. Both hydrolysates and supernatants were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results showed that DPPH radical scavenging ability and reducing power of catfish protein hydrolysates decreased, whereas the ORAC value, metal chelating ability, and ability to inhibit TBARS increased, with an increase in the degree of hydrolysis. Hydrolysate samples showed higher DPPH radical scavenging ability and Fe(3+) reducing ability, and supernatant samples had higher metal chelating ability. In general, low molecular weight (MW) peptides had high ORAC values and high metal chelating ability, and high MW peptides had a higher reducing power (FRAP) and were more effective in scavenging DPPH radicals. In a washed muscle model system, the ability of catfish protein hydrolysates and their corresponding supernatants to inhibit the formation of TBARS increased with an increase in the degree of hydrolysis.  相似文献   

Epibionts of pond-reared adult Malaysian prawns,Macrobrachium rosenbergii (de Man), in South Carolina     

Theodore I.J. Smith  Paul A. Sandifer  John J. Manzi 《Aquaculture (Amsterdam, Netherlands)》1979,16(4):299-308

During 1976, epibionts were noted on adult Malaysian prawns reared in a special ‘brood stock pond’. These epibionts have not previously been recorded on Macrobrachium rosenbergii. Dense algal growths, covering much of the carapace, were observed on 58.3% of the males (mean size, 147.1 g) and on none of the females at harvest. Species composition was primarily (about 90%) the Chlorophyte Oedogonium crassiusculum, with the Cyanophyte Lyngbya, the secondary dominant. The large infested males were sluggish and in some cases functionally blind due to the algal covering. However, once moved to indoor culture tanks the algae were lost and the prawns' behavior returned to normal.Eggs of the water boatman, Ramphocorixa acuminata, were observed on 52.5% of the females (mean size, 78.0 g) and 5.9% of the males at harvest. Egg deposition was limited to the cephalothorax and/or the first and/or second abdominal segments. This epibiont was not noted in the six adjacent rearing ponds containing approximately 84,000 smaller prawns. The insect eggs appeared to cause no injury and disappeared shortly after the infested prawns were returned to laboratory tanks.Although both epibionts exhibited apparent sex specificity in the brood stock pond, data from other rearing ponds did not support this specificity. The occurrence of these epibionts should pose no problem to the successful pond culture of M. rosenbergii in South Carolina.  相似文献   

Contributions of short- and long-shoots to yield of ‘Kerman’ pistachio (Pistacia vera L.)     

Timothy M. Spann  Robert H. Beede  Theodore M. DeJong 《Scientia Horticulturae》2009

The canopy of a mature ‘Kerman’ pistachio (Pistacia vera L.) tree is composed of two types of shoots: short-shoots composed entirely of preformed nodes, and long-shoots composed of both preformed and neoformed nodes. Since the production of these two types of shoots is known to be related to rootstock and rootstock influences yield of pistachio the relationship of these two types of shoots to yield was investigated during two cropping years. Individual short-shoots produced significantly less yield and had fewer fruit clusters per shoot compared with long-shoots, but collectively produced 55–60% of the total yield. Long-shoots positively affected yield components in one year, but had no effect in the other year. Whether the differences in the one year were due to canopy position and light interception or differences in the carbohydrate allocation within the two types of shoots could not be determined from the current data. Long-shoots initiated more inflorescence buds, although inflorescence bud formation was restricted to the preformed growth and only the 3–4 earliest neoformed nodes. However, when expressed as a percentage, long-shoots retained a lower percentage of initiated inflorescence buds, compared with short-shoots. Regardless of shoot type, less than half of the retained inflorescence buds produced mature fruit clusters. Thus, inflorescence bud retention, a previously hypothesized mechanism of pistachio alternate bearing, may not be the primary limiting factor to yield in pistachio.  相似文献   

Evaluation of Key's hypothesis in the feline tibia: an experimental model for augmented bone healing studies     

J P Toombs  L J Wallace  D E Bjorling  G N Rowland 《American journal of veterinary research》1985,46(2):513-518

Key's hypothesis states that a segmental long bone defect 1.5 times the diaphyseal diameter exceeds the regenerative capacity of bone in skeletally mature dogs and results in nonunion. This hypothesis was evaluated in 5 adult cats with rigidly fixated segmental tibial ostectomies ranging from 1.25 to 1.52 times the diaphyseal diameter. Clinical, radiographic, and histologic data were obtained over a 12-week period. Healing was classified as mature bony union, clinical union, delayed union, or nonunion. Absence of a consolidating callus and instability after removal of fixation devices was found for all cats at 12 weeks. Scant formation of new bone within the gap was histologically evident for only 1 cat. In the remaining 4 cats, fibrous tissue and striated muscle predominated within the gap, and independent healing of the proximal and distal cut ends of the bone were observed. The occurrence of 4 nonunions and 1 equivocally delayed union indicated that Key's hypothesis overestimates the regenerative capacity of bone in the cat. Failure of this experimental model to produce clinical union within 12 weeks demonstrated that this model is a valid method of investigating augmented bone healing techniques that promote union within this period in the cat.  相似文献   

THE EFFECT OF INTRAVENOUS DIAZEPAM ON SOLID PHASE GASTRIC EMPTYING IN NORMAL CATS   总被引：1，自引：0，他引：1  

Phillip F.  Steyn  BVSc  MRCVS  MS  David  Twedt  DVM  Wanda  Toombs  CVT 《Veterinary radiology & ultrasound》1997,38(6):469-473

Intravenous diazepam has been advocated as an appetite stimulant in anorexic cats. Diazepam has also been used to stimulate the intake of radiographic contrast medium-food mixture to determine the gastric emptying time of a solid meal. Diazepam has been suspected to delay gastric emptying in cats. One study found diazepam combined with Valium to have little effect on gastric transit times in cats while diazepam alone accelerates gastric emptying in humans. The purpose of this study was to determine if diazepam influences gastric emptying times in normal cats. The gastric emptying half-time of solid food in normal, non-diazepam treated cats has been previously determined using a scintigraphic technique using ^99mTc-sulfur colloid to radiolabel solid dry food. The median gastric emptying half-time was 2.3 hours and the mean meal size was 16.1 grams. Gastric emptying half-times were determined in this study using diazepam as an appetite stimulant. The median gastric emptying half-times of diazepam tratment groups given both a 16.1 gram meal and a large meal were both significantly longer than the normal non-treated group (P c 0.05). Solid phase gastric emptying is therefore significantly delayed when diazepam is used as an appetite stimulant, irrespective of the volume of the meal.  相似文献   

Book reviews     

Frederick H. Buttel  Mary T. Dailey  Theodore E. Downing  Maynard Kaufman 《Agriculture and Human Values》1984,1(2):29-35

  相似文献   

Development of a microsatellite-based method for the differentiation of European wild boar (Sus scrofa scrofa) from domestic pig breeds (Sus scrofa domestica) in food     

Conyers CM  Allnutt TR  Hird HJ  Kaye J  Chisholm J 《Journal of agricultural and food chemistry》2012,60(13):3341-3347

Twenty microsatellites (simple sequence repeats, SSR) were used to discriminate wild boar from domestic pig and to identify mixtures of the two. Reference groups of wild boar and pig samples were collected from the UK and Europe for genetic assignment tests. Bayesian Analysis of Populations software (BAPs) gave 100% correct assignment for blind wild boar and pig samples and correctly identified mixed samples. DNA was extracted from 12 commercial food samples (11 labeled as containing wild boar) including patés, salamis, and sausage, and good SSR profiles were obtained. Eleven samples were correctly assigned as pig, and two as mixed meats. One sample sold as wild boar meat was clearly assigned as pig. A further 10 blind samples of meat cuts were analyzed, eight wild boar and two pig, and all were correctly assigned.  相似文献