Variation in water potential, hydraulic characteristics and water source use in montane Douglas-fir and lodgepole pine trees in southwestern Alberta and consequences for seasonal changes in photosynthetic capacity     

Andrews SF  Flanagan LB  Sharp EJ  Cai T 《Tree physiology》2012,32(2):146-160

Tree species response to climate change-induced shifts in the hydrological cycle depends on many physiological traits, particularly variation in water relations characteristics. We evaluated differences in shoot water potential, vulnerability of branches to reductions in hydraulic conductivity, and water source use between Pinus contorta Dougl. ex Loud. var. latifolia Engelm. (lodgepole pine) and Pseudotsuga menziesii (Mirb.) Franco (interior Douglas-fir), and determined the consequences for seasonal changes in photosynthetic capacity. The Douglas-fir site had soil with greater depth, finer texture and higher organic matter content than soil at the lodgepole pine site, all factors that increased the storage of soil moisture. While the measured xylem vulnerability curves were quite similar for the two species, Douglas-fir had lower average midday shoot water potentials than did lodgepole pine. This implied that lodgepole pine exhibited stronger stomatal control of transpiration than Douglas-fir, which helped to reduce the magnitude of the water potential gradient required to access water from drying soil. Stable hydrogen isotope measurements indicated that Douglas-fir increased the use of groundwater during mid-summer when precipitation inputs were low, while lodgepole pine did not. There was a greater reduction of photosynthetic carbon gain in lodgepole pine compared with Douglas-fir when the two tree species were exposed to seasonal declines in soil water content. The contrasting patterns of seasonal variation in photosynthetic capacity observed for the two species were a combined result of differences in soil characteristics at the separate sites and the inherent physiological differences between the species.  相似文献   

An experimental sod seeder     

M.M. Krog  E.P. Theron  C. Andrews 《African Journal of Range and Forage Science》2013,30(1):126-130

The design and development of an efficient sod‐seeder for the Ngongoni Veld of Natal is described.  相似文献   

Letter to the editor     

J.R.H. Andrews M.SC. PH.D. 《New Zealand veterinary journal》2013,61(10):194-195

Extract

Sir, — In the course of research on infectious bronchitis (IB) in chickens in New Zealand, one strain of IB virus was seleted and attenuated as a local vaccine virus and produced in limited quantities at Massey University for trial purposes.  相似文献   

The effect of phenothiazine on cobalt-deficient and cobalt-dosed lambs     

J.P. Anderson  E.D. Andrews 《New Zealand veterinary journal》2013,61(4):150-151

The mean serum folate concentrations of Large White sows were compared between one group of 13 animals, 43–80 days pregnant and another group of 9 animals at weaning when the litters were 28–30 days old. The mean concentration was higher in sows at weaning (p<0.05) and the lowest levels were found in sows no more than 51 days pregnant (p<0.05).  相似文献   

An outbreak of polio-encephalomalacia in cobalt-deficient sheep     

W.J. Hartley M.R.C.V.S.  Joan C. Kater B.V.Sc.  E.D. Andrews M.Sc. A.N.Z.I.C. 《New Zealand veterinary journal》2013,61(5):118-120

Extract

A great deal of evidence has now accumulated that immunity to helminth infection is acquired following natural exposure. Although this immunity is not absolute, animals that have been exposed to infection and survived are able to tolerate a much heavier intake of infective larvae than animals that have never been exposed.  相似文献   

Glycoproteomic profiling of serum peptides in canine lymphoma and transitional cell carcinoma     

C. R. Wilson  F. E. Regnier  D. W. Knapp  R. E. Raskin  D. A. Andrews  S. B. Hooser 《Veterinary and comparative oncology》2008,6(3):171-181

Differential expression of fucosylated glycoproteins has been correlated with malignancy and metastatic potential in various types of neoplasia. Utilizing glycoproteomics techniques, changes in fucosylated serum peptides associated with naturally occurring canine lymphoma and transitional cell carcinoma (TCC) have been evaluated. In both types of neoplasia, the majority of the fucosylated peptides that changed increased with the cancer. In one lymphoma case that was examined over the course of the disease, the same fucosylated peptides that increased during pre-chemotherapy decreased during post-chemotherapy, and then subsequently increased upon recurrence of the lymphoma. When comparing all the fucosylated peptides that increased in both types of cancer, there were only two peptides in common allowing discrimination between lymphoma and TCC based on their peptide profiles. These results emphasize the prospect of glycopeptide profiling in proteomics for use in discovering a panel of non-invasive, diagnostic or prognostic biomarkers of cancer.  相似文献   

Comparative Evaluation of 2 In-Clinic Assays for Vector-Borne Disease Testing in Dogs     

Jiayou Liu  Jan Drexel  Blaine Andrews  Matt Eberts  Ed Breitschwerdt  Ramaswamy Chandrashekar 《Topics in companion animal medicine》2018,33(4):114-118

Vector-borne agents comprise medically important infections affecting dogs throughout much of the world. Sensitive detection of antibodies directed at tick-borne disease-causing organisms in dogs is diagnostically important for veterinarians, pets and their owners, and epidemiologically important for public health surveillance. The SNAP 4Dx Plus Test (IDEXX Laboratories, Inc., Westbrook, ME) identifies antibodies to or infection with multiple tick-borne pathogens and canine heartworm antigen in a single assay. Recently, VetScan FLEX4 Rapid Test (Abaxis, Inc., Union City, CA) was launched as a new assay to detect tick-borne pathogen antibodies and heartworm antigen. In the present study, we evaluated the comparative performance of SNAP 4Dx Plus (SNAP) and FLEX4 Rapid Test (FLEX4) using samples selected based on geographic distributions for canine vector borne diseases, including Borrelia burgdorferi (n = 105), Anaplasma phagocytophilum (160), Anaplasma platys (115), Ehrlichia canis (154), Ehrlichia ewingii (163), Ehrlichia chaffeensis (151) and Dirofilaria immitis (105). Canine vector borne diseases infection status was established for each sample by a combination of reference methods that included necropsy (D. immitis, heartworm disease), Western immunoblotting (B. burgdorferi), immunofluorescence assays (A. phagocytophilum and E. canis) and species-specific ELISAs (A. platys, E. canis, E. ewingii and E. chaffeensis). For comparisons among the 2 assays, samples were evaluated per the manufacturers’ instructions for each test kit.By testing each same sample set compared to the defined reference results, sensitivities differed substantially between SNAP and FLEX4, at 95.5 vs. 40.9%, respectively for B. burgdorferi, 97.1% vs. 61.4% for E. canis, 98.2% vs. 59.3% for E. ewingii, 64.3% vs. 35.7% for E. chaffeensis, 84.5% vs. 12.7% for A. phagocytophilum, 83.3% vs. 33.3% for A. platys, and 94.1% vs. 88.2% for D. immitis. Specificities for both rapid assay tests ranged from 98% to 100%.Based upon the comparative results derived from this study, the SNAP test was more sensitive than the FLEX4 test for detection of antibodies to all tick-borne pathogens and heartworm disease (Dirofilaria immitis) antigen in dogs.  相似文献   

Veterinary poisons information service     

Andrews A  Dalton JR 《The Veterinary record》2007,161(18):635

  相似文献   

The Effect of Sedation on Gastric Emptying of a Liquid Marker in Ponies     

Thomas J. Doherty  MVB  MSc  Diplomate ACVA    Frank M. Andrews  DVM  MS  Diplomate ACVIM    Melanie K. Provenza  BS    Donita L. Frazier  DVM  PhD  Diplomate ABVT 《Veterinary surgery : VS》1999,28(5):375-379

OBJECTIVE: The effect of sedation on gastric emptying was evaluated in six ponies by monitoring serum concentrations of acetaminophen (AP) after intragastric administration. EXPERIMENTAL DESIGN: Prospective randomized experimental study. ANIMALS: Six adult ponies, 135 to 275 kg. METHODS: Fifteen minutes after the intravenous administration of xylazine (1 mg/kg), butorphanol (0.05 mg/kg), acepromazine (0.05 mg/kg) or saline, ponies were given AP (20 mg/kg in 350 mL water) by stomach tube. Blood for AP analysis was collected at baseline and 15, 30, 45, 75, 90, 105, and 120 minutes after AP administration. The time (Tmax) to reach peak serum concentration (Cmax), and the area under the AP serum concentration versus time curve (AUC) were determined for each treatment group. RESULTS: Tmax was 31 mins in the control group, and this increased significantly (P<.05) after sedation. Cmax decreased (P<.05) after xylazine administration, and AUC decreased (P<.05) after acepromazine. CONCLUSIONS: This study indicated that sedation has a significant effect on the gastric emptying rate of a liquid in ponies.  相似文献   

Effects of orally administered enteric-coated omeprazole on gastric acid secretion in horses.     

F M Andrews  T J Doherty  J T Blackford  J A Nadeau  A M Saxton 《American journal of veterinary research》1999,60(8):929-931

OBJECTIVES: To determine the effects of orally administered omeprazole, as enteric-coated capsules, on baseline and stimulated gastric acid secretion in horses. ANIMALS: 5 healthy 8-year-old mixed-breed horses fitted with gastric cannulas. PROCEDURE: Enteric-coated granules of omeprazole were mixed with corn syrup and administered orally once daily for 5 consecutive days. On days 1 and 5 beginning 5 hours after omeprazole administration, 4 gastric fluid samples were collected, each for 15 minutes, via the gastric cannula (baseline samples). Pentagastrin was administered IV as a constant infusion for the subsequent 2 hours, and 15-minute gastric fluid samples were again collected (stimulated samples). Fluid volume, acidity (mmol H-/L), and pH and gastric acid production (mmol H+) were determined for all baseline samples and for stimulated samples collected during the second hour of pentagastrin infusion. Control experiments were done in a similar manner after giving corn syrup alone to the same horses. RESULTS: Compared with values obtained during control experiments, baseline and stimulated gastric fluid acidity and gastric acid production significantly decreased, and the mean pH of gastric fluid samples significantly increased, after horses were given 5 daily doses of omeprazole. CONCLUSIONS AND CLINICAL RELEVANCE: Enteric-coated omeprazole (1.0 mg/kg of body weight; PO) administered once daily for 5 days significantly inhibited unstimulated and pentagastrin-stimulated gastric acid secretion in horses. This commercially available formulation of omeprazole may be efficacious in the treatment of gastroduodenal ulcers in horses.  相似文献