Lymphocyte antigens of sheep: identification and characterization using a panel of monoclonal antibodies

A panel of monoclonal antibodies has been developed and used to identify and characterize the lymphocyte antigens of sheep. These studies have shown that sheep lymphocyte antigens display similar, if not identical, tissue distributions to their analogues in other species. Some of the major sheep antigens, including CD5, CD4, CD8, SBU-T19, Pgp-1, LCA and the MHC antigens, are described in detail.     

Effect ofErwinia carotovora subsp.atroseptica alone and withAlternaria solani orVerticillium dahliae on disease development and yield of potatoes in Israel

Summary Tubers of 17 cultivars were inoculated withErwinia carotovora subsp.atroseptica (ECA) and planted in 1986 and 1987 in the Negev in randomised plots in three blocks where eitherVerticillium dahliae orAlternaria solani were present or where both were absent. ECA reduced the yield in the control block and exacerbated the yield losses in the disease blocks, but the intensity of symptom expression did not always accord with the extent of yield loss. ECA had a greater effect on plants infected withA. solani than on those withV. dahliae. It was possible to categorise the cultivars as resistant, intermediate or susceptible with respect to ECA and early blight, but resistance toV. dahliae could not be differentiated from foliage maturity.     

Progeny testing for resistance to potato virus Y: a comparison of susceptible potato cultivars for use in testcrosses with resistant parents

Summary For potato breeding or genetical research purposes, the number of copies of a dominant major gene for resistance to potato virus Y in a parent clone can be determined by test-crossing with a susceptible parent and observing the segregation ratio of resistant to susceptible seedlings in the progeny. In a comparison of different susceptible cultivars for use in test-crosses for this purpose, their progenies differed in the clarity of symptoms and parental phenotype proved an unreliable guide. Cvs Maris Piper, Arran Peak and Dr MacIntosh were found to be suitable tester parents, Pentland Squire less so and cv. Désirée was confirmed as having a major gene conferring incomplete resistance. It was found advisable to test-cross with more than one susceptible parent.     

Effect ofErwinia carotovora subsp.atroseptica on yield of potatoes from cut and uncut seed tubers in Valencia

Summary The effect on the development of blackleg symptoms and on yield of inoculating seed tubers of 15 cultivars withErwinia carotovora subsp.atroseptica (Eca) was investigated. Tubers were planted either whole or as pieces. Eca inoculation reduced the mean yield per plant by 8% for whole tubers and by 12% for cut tubers. There was no correlation between blackleg symptoms and yield loss.     

Partitioning and translocation of photosynthetically fixed 14C in grazed hill pastures

Information on carbon (C) flows and transformations in the rhizosphere is vital for understanding soil organic matter dynamics and modelling its turnover. We followed the translocation of photosynthetically fixed C in three hill pastures that varied in their phosphorus (P) fertility, using a ¹⁴C-CO₂ pulse-labelling chamber technique. Pasture shoot, root and soil samples were taken after 4h, 7 days and 35 days chase periods to examine the fluxes of ¹⁴C in the pasture plant-root-soil system. Shoot growth over 35 days amounted to 114, 179 and 182gm^–2 at the low (LF), medium (MF) and high (HF) fertility pasture sites, respectively. The standing root biomass extracted from the soil did not differ significantly between sampling periods at any one level of fertility, but was significantly different across the three levels of fertility (1367, 1763 and 2406gm^–2 at the LF, MF and HF pastures, respectively). The above- and below-ground partitioning of ¹⁴C was found to vary with the length of the chase period and fertility. Although most ¹⁴C (74%, 65% and 57% in the LF, MF and HF pastures, respectively) was in the shoot biomass after 4h, significant translocation to roots (23–39%) was also detected. By day 35, about 10% more ¹⁴C was partitioned below-ground in the LF pasture compared with the HF pasture. This is consistent with the hypothesis that, at limiting fertility, pasture plants allocate proportionally more resource below-ground for the acquisition of nutrients. In the LF site, with an annual assimilated C of 7064kgha^–1, 2600kg was respired, 1861kg remained above-ground in the shoot and 2451kg was translocated to roots. In the HF pasture, of the 17313kgha^–1 C assimilated, 7168kg was respired, 5298 remained in the shoot and 4432kg was translocated to the roots. This study provides, for the first time, data on the fluxes and quantities of C partitioned in a grazed pasture. Such data are critical for modelling C turnover and for constructing C budgets for grazed pasture ecosystems. Received: 31 July 1996     

Emissions from in situ burning of crude oil in the arctic

The results of an exploratory study of the effects of in situ crude oil spill burning on air quality in the Beaufort Sea region of the Arctic are presented. A scenario is postulated defining the amounts of oil released, the size and number of burnable oil pools, and the duration of the burning period. Estimates are made of the likely emissions of soot, CO, SO₂ and metals based on literature and some experimental work. Assumptions are made about plume rise and dispersion which permit downwind concentrations of emissions to be calculated and compared with air quality objectives. Although the calculated concentrations may contain significant error because of the many assumptions, it is believed that the data demonstrate that concentrations of SO₂ and CO will be acceptably low, concentrations of soot and metals will often be undesirably high within 10 km of the fires, but will be acceptably low at greater distances. It is concluded that burning may be a method of substantially reducing the adverse environmental impact of oil spills in the Arctic.     

Amylolytic activity in stored potato tubers. 1. Estimation usingp-nitrophenyloligosaccharides

Summary Methods for the estimation of amylolytic activity are reviewed. A procedure for the routine extraction of amylolytic activity from freeze-dried powder prepared from potato tubers is described. The extraction medium is buffered at pH 7.0 and contains glycerol, dithiothreitol, calcium chloride and the non-ionic detergent, nonidet P-40. α-Amylase activity and exoamylolytic activity were estimated in crude extracts of potato tubers using the substrates, blockedp-nitrophenyl-maltoheptaoside andp-nitrophenyl-maltopentaoside respectively. These substrates are included in kits supplied by Biocon, (UK) Ltd to measure the α- and ?-amylase activity in cereals. The validity of using these kits for the determination of α- and ?-amylase activity in potato tuber tissue is discussed.     

Effects of tramadol alone,in combination with meloxicam or dipyrone,on postoperative pain and the analgesic requirement in dogs undergoing unilateral mastectomy with or without ovariohysterectomy

ObjectiveTo compare the effects of tramadol alone, or in combination with dipyrone or meloxicam, on postoperative pain and analgesia requirement after unilateral mastectomy with or without ovariohysterectomy in dogs.Study designProspective, randomized, clinical study.AnimalsTwenty seven bitches undergoing unilateral mastectomy with or without ovariohysterectomy.MethodsAnesthesia was induced with propofol and maintained with isoflurane and a constant rate infusion of morphine. Before the end of surgery, dogs were randomly assigned to receive intravenous tramadol alone (3 mg kg^?1, group T), combined with dipyrone (30 mg kg^?1, group TD) or meloxicam (0.2 mg kg^?1, group TM). Dogs received additional doses of tramadol (groups T and TM) or tramadol with dipyrone (group TD) at 8 and 16 hours after extubation. Postoperative pain was assessed by a blinded observer before anesthesia (baseline) and at 1, 2, 3, 4, 6, 8, 12, 16 and 24 hours after extubation using a visual analog scale (VAS) and a modified Glasgow scale. Rescue analgesia (morphine, 0.5 mg kg^?1) was administered if the Glasgow pain score was >3.5.ResultsThere were no significant differences among groups in pain scores evaluated by the VAS or the Glasgow scale. In groups T, TD and TM, pain scores were significantly higher than at baseline for 6, 8 and 2 hours, respectively. Rescue analgesia was administered to 3/9, 2/9 and 1/9 dogs in groups T, TD and TM, respectively (p > 0.05) [Correction added on 15 August 2013, after first online publication: ‘T, TM and TD’ was changed to ‘T, TD and TM’.].Conclusions and clinical relevanceUnder the conditions of this study, tramadol alone or in combination with dypyrone or meloxicam provided effective analgesia for 24 hours in most dogs after unilateral mastectomy with or without ovariohysterectomy. Further evaluation of combination therapies is needed in larger groups of dogs.