Prevalence of Giardia spp. infection in pre-weaned and weaned calves in relation to management factors     

Muhid A  Robertson I  Ng J  Yang R  Ryan U 《Veterinary journal (London, England : 1997)》2012,191(1):135-137

Two hundred and forty calf faecal samples from 16 Malaysian farms were screened by PCR for Giardia spp. The overall prevalence was 12.5% and the overall farm prevalence was 68.8% (11/16 farms). The prevalence in pre-weaned and weaned calves was 16.7% and 8.3%, respectively. Sequence analysis of 25 isolates identified all as G. duodenalis assemblage E. Management factors associated with an increased risk of infection with Giardia spp. included keeping weaned calves in pens with sand floors and calf age. Keeping pre-weaned calves in pens with concrete floors and calving in single cow calving areas decreased the risk.  相似文献   

Method: low-cost delivery of the cotton leaf crumple virus-induced gene silencing system   总被引：1，自引：0，他引：1  

JR Tuttle  CH Haigler  D Robertson 《Plant methods》2012,8(1):27-8

Background

We previously developed a virus-induced gene silencing (VIGS) vector for cotton from the bipartite geminivirusCotton leaf crumple virus (CLCrV). The original CLCrV VIGS vector was designed for biolistic delivery by a gene gun. This prerequisite limited the use of the system to labs with access to biolistic equipment. Here we describe the adaptation of this system for delivery by Agrobacterium (Agrobacterium tumefaciens). We also describe the construction of two low-cost particle inflow guns.

Results

The biolistic CLCrV vector was transferred into two Agrobacterium binary plasmids. Agroinoculation of the binary plasmids into cotton resulted in silencing and GFP expression comparable to the biolistic vector. Two homemade low-cost gene guns were used to successfully inoculate cotton (G. hirsutum) and N. benthamiana with either the CLCrV VIGS vector or the Tomato golden mosaic virus (TGMV) VIGS vector respectively.

Conclusions

These innovations extend the versatility of CLCrV-based VIGS for analyzing gene function in cotton. The two low-cost gene guns make VIGS experiments affordable for both research and teaching labs by providing a working alternative to expensive commercial gene guns.  相似文献   

Retrospective analysis of detomidine infusion for standing chemical restraint in 51 horses     

DV Wilson BVSc  MS  Dipl ACVA    GV Bohart DVM    AT Evans DVM  MS  Dipl ACVA    S Robertson BVMS  PhD  Dipl ACVA  Dipl ECVA    Y Rondenay†DVM 《Veterinary anaesthesia and analgesia》2002,29(1):54-57

Objective To assess the effectiveness of a detomidine infusion technique to provide standing chemical restraint in the horse. Design Retrospective study. Animals Fifty‐one adult horses aged 9.5 ± 6.9 years (range 1–23 years) and weighing 575 ± 290.3 kg. Methods Records of horses presented to our clinic over a 3‐year period in which a detomidine infusion was used to provide standing chemical restraint were reviewed. Information relating to the types of procedure performed, duration of infusion, drug dosages and adjunct drugs administered was retrieved. Results Detomidine was administered as an initial bolus loading dose (mean ± SD) of 7.5 ± 1.87 µg kg^?1. The initial infusion rate was 0.6 µg kg^?1 minute^?1, and this was halved every 15 minutes. The duration of the infusion ranged from 20 to 135 minutes. Twenty horses received additional detomidine or butorphanol during the procedure. All horses undergoing surgery received local anesthesia or epidural analgesia in addition to the detomidine infusion. A wide variety of procedures were performed in these horses. Conclusions Detomidine administered by infusion provides prolonged periods of chemical restraint in standing horses. Supplemental sedatives or analgesics may be needed in horses undergoing surgery. Clinical relevance An effective method that provides prolonged periods of chemical restraint in standing horses is described. The infusion alone did not provide sufficient analgesia for surgery and a significant proportion of animals required supplemental sedatives and analgesics.  相似文献   

Pulmonary surfactant from healthy Belgian White and Blue and Holstein Friesian calves: biochemical and biophysical comparison     

Danlois F  Zaltash S  Johansson J  Robertson B  Haagsman HP  Rollin F  Ruysschaert JM  Vandenbussche G 《Veterinary journal (London, England : 1997)》2003,165(1):65-72

The biochemical composition and biophysical behaviour of pulmonary surfactant samples isolated from healthy Belgian White and Blue (BWB) and Holstein Friesian (HF) calves have been investigated and compared. Interesting differences in composition have been demonstrated. In particular, a higher level of total hydrophobic surfactant-associated proteins (SP) (due to higher levels of SP-B and SP-C) is reported in HF calves compared to BWB calves. Higher levels of phosphatidylcholine (PC) and especially the disaturated form of PC were also found in HF as compared to BWB calves. No immediate effect on the surface tension properties evaluated by the pulsating bubble surfactometer was found between the surfactant samples of the two breeds under physiological conditions. However, since a high content of disaturated PC and the presence of the SP-B and SP-C are thought to be essential for the surface activity, we propose that the reported modifications could contribute to the apparently lower resistance of the BWB calves to respiratory troubles in comparison with HF calves.  相似文献   

Adaptation of thermal threshold analgesiometry for NSAIDs in cats: effects of ketoprofen   总被引：1，自引：0，他引：1  

PM  Taylor  SA Robertson  MJ Dixon 《Veterinary anaesthesia and analgesia》2003,30(2):91-91

Nonsteroidal anti‐inflammatory drugs (NSAIDs) are widely used to provide analgesia in clinical veterinary medicine, but there are few objective data evaluating this effect under controlled conditions in cats. Analgesia is more difficult to detect with acute analgesiometry after NSAIDs than after opioids. This investigation aimed to adapt the feline thermal analgesiometry method previously employed with opioids ( Dixon et al. 2002 ) for use with NSAIDs. Ketoprofen, a COX1 inhibitor licensed for cats was chosen. Six cats (2 neutered, four entire females, weighing 2.2–5.4 kg) were studied in two blinded randomized crossover trials each at least 2 weeks apart. Thermal thresholds (TT) were measured using the thermal threshold‐testing device previously developed for cats. A heater element and temperature sensor in a small probe were held at constant pressure against the cats' shaved thorax with an elasticized band. Skin temperature was recorded before each test, then the heater activated. When the cat responded by flinching, turning or jumping the heater was turned off and the temperature recorded. In the first study TT were measured following subcutaneous (SC) injection of ketoprofen (2 mg kg^?1) or a similar volume of saline. In the second study, prior to TT, and under isoflurane restraint, a mild inflammatory focus was produced at the probe site by five SC injections of 5 mg kaolin in 0.1 mL saline at each corner and in the center of a 1.5‐cm square. Saline or ketoprofen as in the first study were injected at the same time. Three baseline temperatures were recorded before any injections were given. Thermal thresholds were measured at 1 and 2 hours and then two‐hourly for 24 hours. Data were analysed using anova . Baseline skin temperature increased (37.3 ± 0.5–38.1 ± 0.8 °C) 24 hours after saline injection in study 2 (p < 0.05) but did not change after any other treatment. Thermal thresholds decreased (40.0 ± 1.3 to 39.1 ± 0.4 °C) 16 hours after ketoprofen in study 1 (p < 0.05) and increased (41.6 ± 1.5–44.8 ± 6.1 °C) 16–24 hours after ketoprofen in study 2 (p < 0.05), with no significant changes after saline. No obvious increase in sensitivity to thermal stimulation after kaolin injection was detected although obvious inflammation was present for up to 36 hours and the cats responded to digital pressure at the treated site. The method detected some effects of a COX1 selective NSAID and may be suitable for future NSAID studies in cats. However, a pressure stimulus ( Dixon et al. 2000) may prove better than thermal, and it requires investigation.  相似文献   

Monoclonal antibodies specific for Campylobacter fetus lipopolysaccharides     

Brooks BW  Robertson RH  Lutze-Wallace CL  Pfahler W 《Veterinary microbiology》2002,87(1):37-49

Four monoclonal antibodies (mAbs) (M1357, M1360, M1823 and M1825) which reacted with Campylobacter fetus lipopolysaccharide (LPS) core region epitopes were produced and characterized. Reactivity of these mAbs with C. fetus core LPS epitopes was determined by enzyme-linked immunosorbent assay (ELISA) with whole cell proteinase K digests and phenol-water extracted LPS, and by immunoblotting with proteinase K digests. The specificities of the four mAbs were evaluated using an indirect ELISA. One of the mAbs reacted with 42 and three of the mAbs reacted with 41 of the 42 C. fetus strains examined. No reaction was observed between the four mAbs and 32 non-C. fetus bacteria tested, with the exception of one mAb with one organism. The four mAbs reacted with serotype A and B strains indicating the presence of shared epitopes in C. fetus LPS core oligosaccharides. The specificities of three mAbs previously produced to C. fetus LPS O-antigens (M1177, M1183 and M1194) were also evaluated and no reaction was observed with these mAbs and the 32 non-C. fetus bacteria tested. Strong immunofluorescence reactions were observed with the anti-O chain mAbs and selected C. fetus strains of the homologous serotype. These anti-LPS core oligosaccharide and anti-LPS O chain mAbs are highly specific for C. fetus and are potentially useful as immunodiagnostic reagents for detection, identification and characterization of C. fetus.  相似文献   

Combining Glyphosate With Burning or Mowing Improves Control of Yellow Bluestem (Bothriochloa ischaemum)     

Scott Robertson  Karen R. Hickman  Keith R. Harmoney  David M. Leslie 《Strength and Conditioning Journal》2013,66(3):376-381

The invasive yellow bluestem (Bothriochloa ischaemum [L.] Keng) threatens native biodiversity, and its control is of interest to land managers involved in restoration of invaded grasslands. We used single, double, and triple applications of glyphosate (2.125 kg ai · ha^?1 · application^?1) over the course of one growing season in combinations at different timings (early, middle, late season) with and without a mechanical treatment of mowing or burning to determine the most effective control method. One year after treatment, burning and mowing prior to a mid-season single or double early, middle, and/or late season herbicide application resulted in a similar level of control of yellow bluestem relative to a triple herbicide application, all of which had greater control relative to herbicide treatment alone. Reproductive tiller density and visual obstruction increased 2 yr after treatment with two herbicide treatments applied either early and middle season or early and late season, but it was prevented with burning and mowing prior to herbicide application. With the exception of three herbicide applications, combining burning or mowing with herbicide applications provided more effective control of yellow bluestem than any individual herbicide applications. Burning or mowing likely improves glyphosate effectiveness by altering the invasive grass structure so that plants are clear of standing dead and have shorter, active regrowth to enhance herbicide effectiveness. During restoration projects requiring control of invasive yellow bluestem, an effective management option is a combination of mechanical and chemical control.  相似文献   

Recent records of megalopae of the crab Varuna litterata (Fabr.) entering Natal estuaries     

A.D. Connell  Wendy Robertson 《African Zoology》2013,48(2):184-185

An unusual occurrence Involving the stranding of many thousands of megalopae of the crab Varuna litterata on an outgoing tide is recorded. The locality was sandflats adjacent to the mouth of the Mgobezelenl estuary at Sodwana Bay, Natal, In mid-May 1985. Other records of recent local sightings are Included.  相似文献   

Preliminary estimates of population size and capture rates of mature Acanthopagrus berda in the Kosi lakes system,South Africa,using mark-recapture methods     

R. Kyle  W.D. Robertson 《African Zoology》2013,48(4):124-128

Population size estimates and capture rates by various fishing techniques of mature estuarine bream, Acanthopagrus berda, were determined in the Kosi lakes system using mark-recapture methods. The total population size of mature A. berda was estimated to be 45 257 (95% confidence interval: 31 589-74 429) based on fish recaptured in fish traps and 56 112 (95% confidence interval: 25 505-374 080) using recaptures from recreational anglers. Fish traps were estimated to catch about 5% of the mature population of A. berda annually, while recreational rod and line angling and traditional spearfishing accounted for about 1% and 0.2% of the mature population respectively. Limited mark-recapture data for other species of fishes in the lakes yielded annual capture rates by fish traps ranging from 2.4% to 5.8%. These levels of fishing appear low enough to be sustainable, but evidence from a long-term monitoring programme indicates an increase in overall fishing effort in the Kosi lakes between 1984 and 1996 and a three-fold increase in the proportion of the A, berda population caught annually. However, there is no evidence from available catch per unit effort (CPUE) data that current levels of harvesting of A. berda are unsustainable. This needs to be confirmed through modelling of the A. berda stocks and continued monitoring of CPUE in all components of the Kosi lakes fishery. In the meantime, an increase in fishing effort directed at this species is not recommended.  相似文献   

The Impact of Hardwood Line-Planting on Tree and Amphibian Diversity in a Secondary Subtropical Wet Forest of Southeast Puerto Rico     

Mark Nelson  Sally Silverstone  Kelly C. Reiss  Patricia Burrowes  Rafael Joglar  Molly Robertson 《Journal of Sustainable Forestry》2013,32(5):503-516

The impact on tree and amphibian diversity of line-planting of tropical hardwoods—mahogany (Swietenia macrophylla × S. mahagoni) and mahoe (Hibiscus elatus)—was studied in a secondary subtropical wet forest of Puerto Rico. Common coqui (Eleutherodactylus coqui) and melodious coqui (E. wightmanae) are the most frequent frog species; forest coqui (E. portoricensis) is less abundant. Although relative abundance means were slightly greater in the undisturbed forest and during the wet season, differences were not statistically significant suggesting that line-planting did not significantly affect amphibian diversity. The line-planted areas had a slightly higher, but not statistically significant diversity, richness, and evenness of tree species than the unplanted forest. Multi-response permutation procedure (MRPP) showed statistically significant community composition differences between line-planting and control plot trees (T = ?5.89, A = .86; p < .001). But mean similarity among plots in both the line-planted and control plots was relatively low at less than 50% of shared species, indicating high diversity of vegetation in the overall forest area. Canopy cover by tree species greater than 3 cm in dbh was much higher in the undisturbed forest but this difference may be reduced as the young line-planted hardwoods mature. Forest enrichment through line-planting of valuable timber species in secondary subtropical wet forest does not significantly affect tree diversity.  相似文献