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91.
Estimates of glacial-interglacial climate change in tropical Africa have varied widely. Results from a process-based vegetation model show how montane vegetation in East Africa shifts with changes in both carbon dioxide concentration and climate. For the last glacial maximum, the change in atmospheric carbon dioxide concentration alone could explain the observed replacement of tropical montane forest by a scrub biome. This result implies that estimates of the last glacial maximum tropical cooling based on tree- line shifts must be revised. 相似文献
92.
Technology transfer is a multi-level process of communication involving a variety of senders and receivers of ideas and materials. As a response to market failure, or as an effort to accelerate market-driven social change, technology transfer may combine public and private aparatus or rely solely on public institutional mechanisms to identify, develop, and deliver innovations and information. Technology transfer institutions include universities, government ministries, research institutes, and what may be termed the ‘project sector’. Four farm- and village-level change models are considered: traditional community development, adoption-diffusion, training and Visit Extension, and Farming Systems Research. The challenges to technology transfer efforts center on developing indigenous capacity to generate and adapt agricultural technology to local conditions. This is the primary objective of technology transfer in agriculture and the basis for advancing rural development. 相似文献
93.
von Takach Brenton Jolly Chris J. Dixon Kelly M. Penton Cara E. Doherty Tim S. Banks Sam C. 《Landscape Ecology》2022,37(6):1469-1482
Landscape Ecology - Increases in fire frequency, intensity and extent are occurring globally. Relative to historical, Indigenous managed conditions, contemporary landscapes are often characterised... 相似文献
94.
PWM Kronen DVM PF Moon-Massat DVM DipACVA JW Ludders DVM DipACVA RD Gleed BVSc MRCVS DVA DipACVA DipECVA TJ Kern DVM DipACVO J Randolph DVM DipACVIM H N Erb DVM MS PhD 《Veterinary anaesthesia and analgesia》2001,28(3):146-155
Objective To evaluate the effectiveness of two insulin doses to maintain an acceptable range of blood glucose concentrations (70–200 mg dL?1) in the peri‐operative period in diabetic dogs. Animals Twenty‐four diabetic dogs with a median weight of 20.6 kg and a median age of 8 years old. Methods The dogs were randomly assigned to receive either 25 or 100% of their normal insulin dose subcutaneously on the morning of surgery. The anesthetic and feeding protocols were standardized. On the day before surgery, venous blood was collected for measurement of β‐hydroxybutyrate, cholesterol, glucose, glycosylated hemoglobin, hematocrit, total plasma protein and urea nitrogen. On the day of surgery, blood glucose concentrations were measured prior to anesthesia, prior to the start of surgery, 1 and 2 hours after beginning of surgery, 1 hour after extubation, at 16 : 00 hours and at 20 : 00 hours. β‐hydroxybutyrate concentrations were measured at 20 : 00 hours that day. At 08 : 00 hours the following day, β‐hydroxybutyrate and glucose concentrations were measured. The significance of differences between groups was tested with Wilcoxon's two‐tailed rank‐sum test, Chi‐square test and Fisher's exact test. Results There were no differences in insulin treatments, clinical signs, concurrent diseases and most clinicopathological parameters between the two groups of dogs at entry to the study. The 25% dose group had blood glucose values of 296 (102–601) mg dL?1 at 16 : 00 hours and 429 (97–595) mg dL?1 at 20 : 00 hours on the day of surgery. The 100% insulin dose group had lower corresponding values of 130 (55–375) mg dL?1 (p = 0.04) and 185 (51–440) mg dL?1 (p = 0.004). No other differences (p < 0.05) were detected between the two groups. Conclusions The administration of a full dose of insulin is only marginally advantageous for reducing glucose to normal (70–120 mg dL?1) after anesthesia but neither dose consistently induced glycemic values in an acceptable range (70–200 mg dL?1) or normoketonemia. Clinical relevance Blood glucose should be measured immediately before anesthesia and periodically throughout the peri‐operative period in all diabetic dogs because presurgical subcutaneous administration of 25 or 100% of the normal insulin dose resulted in unpredictable blood glucose concentrations. 相似文献
95.
H Chevalier LP Posner JW Ludders HN Erb RD Gleed 《Veterinary anaesthesia and analgesia》2003,30(2):114-114
Our purpose was to assess the accuracy and precision of a point of care hemoglobinometer (HemoCue‐B hemoglobin photometer) for measuring hemoglobin concentration in horse blood. Samples of jugular venous blood from 12 healthy adult horses were collected in EDTA. In order to test the device over a wide range of values, each sample was divided into nine aliquots, and autologous plasma was added or removed from the aliquots to produce blood with PCV values that approximated 5, 10, 20, 30, 40, 50, 60, 70, and 80%, respectively. The aliquots were rocked to ensure mixing of plasma and cells. Then hemoglobin by HemoCue‐B (HbHQ) and hemoglobin by the cyanmethemoglobin method (HbCY) were measured on each aliquot. The PCV of each aliquot was also measured and this value was used for subsequent analyses. To test repeatability, hemoglobin was measured twice by the HemoCue‐B on approximately 40% samples. Samples with HbHQ >25.4 g dL?1 required dilution prior to analysis. HbCY ranged from 1.6 to 33.4 g dL?1. After regression, HbCY = ?0.16 + 1.04 HbHQ (n = 101; r2 = 99.6%). By inspection of a modified Bland‐Altman plot, HbHQ values <16 g dL?1 closely approximated HbCY; however, at greater values, HbHQ underestimated HbCY by as much as 3.2 g dL?1. The difference between repeated measurements with the HemoCue‐B was 0.02 ± 0.16 g dL?1 (mean ± SD; n = 10) and nonsignificant. After regression, PCV = ?0.76 + 2.78 HbHQ (n = 101; r2 = 99.4%). We conclude that HemoCue‐B can be used to measure hemoglobin concentration in horse blood, and that it is accurate when hemoglobin is <16 g dL?1. PCV can be estimated by multiplying HbHQ by 2.8 and then subtracting 0.8. 相似文献
96.
R.D. Jolly B.V.Sc Ph.D. 《New Zealand veterinary journal》2013,61(6):91-94
A field trial was carried out to compare 3 topical treatments for ovine footrot. They were preliminary hoof paring with weekly footbathing either in 10% formalin, or in 10% zinc sulphate + 0.2% anionic surfactant (‘Teepol’), or twice-weekly footbathing in the same zinc sulphate-surfactant mixture without hoof paring. Control sheep were not treated. Within 21 days, the number and severity of active lesions of footscald and footrot among treated sheep were substantially reduced by comparison with the controls; no significant differences were ohserved between treatments. Treatment effects were also comparable against mild footrot infection of the sole or heel region, hut in the more advanced lesions the healing response to paring and zinc footbathing was superior to that from paring and formalin footbathing (P<0.01). Twice-weekly foothathing in zinc-surfactant solution was effective in preventing new footrot infection. No chronic toxic effects attributable to zinc suluhate at a concentration of 10% were demonstrable in the hoof integument either clinically or histologically. 相似文献
97.
R.D. Jolly B.V.Sc. Ph.D. L.B. Fastier M.Sc. Ph.D. H.J.F. McAllum B.Sc. 《New Zealand veterinary journal》2013,61(10):178-180
Abstract Extract Madam:—Out of season (autumn/winter) lambing is expanding in northern areas. These lambs need to grow at moderate rates through the late winter feed trough so they can fully utilise the spring flush to reach heavy weights before summer. Autumn-born lambs are likely to face high parasite roundworm challenge pre- and post-weaning. Strongyle faecal egg counts of autumn and spring-born lambs at weaning averaged 2000 and 400 eggs/g respectively (n=30) under an all-sheep, splitseason lambing policy near Kaikohe. (7) Roundworm infestation can also reduce selenium concentration in the liver. (2) Although Se level in pasture tends to be higher in autumn/winter than in spring/summer (l) this could be offset by lower pasture availability. Better winter growth rates have been recorded in weaned calves from a combination anthelmintic/selenium drench than from either of these alone. (5) 相似文献
98.
AIMS: To describe the histopathological lesions of a new canine disease characterised by progressive ataxia, head tremor and seizures, and to deduce the cause of the lesions. METHODS: Formalin-fixed tissues were processed into paraffin wax and epoxy resin for light and transmission electron microscopy of variously stained tissue sections. RESULTS: Significant lesions relevant to the disease were found only in the brain. They consisted of hypoplasia of the cerebellum and the presence of large pale inclusions in the perikaryon of neurons in the neocortex and in macrophages. The inclusion material was not compartmentalised and did not stain for carbohydrate, mucopolysaccharide or lipid. This material displaced nuclei to the periphery of the cells where they were seen as basophilic distorted crescent-shaped structures. CONCLUSIONS: The inclusions were probably made of polymerised protein similar, though not identical, to those of Pick, Lewy and Collins bodies that characterise a variety of chronic neurodegenerative diseases of humans. A genetic basis to this disease was considered probable. 相似文献
99.
R.D. Jolly B.V.Sc. Ph.D. M.A.C.V.Sc. H.W. Leipold Dr.med.vet. M.S. Ph.D. 《New Zealand veterinary journal》2013,61(7):147-155
Extract Genetic variation, whether due to the fortuitous recombination of genes at meiosis and fertilization, or to mutation, is the means of evolution and the tool of the animal breeder. Along with favourable variations of the genome, there may be unfavourable variations, some so unfavourable as to result in clinically apparent disease. Therefore, it is biologically normal for genetically induced diseases to occur in all species, races or breeds. Such disease may be caused by structural or functional defects of many kinds and it is important to differentiate these from similar diseases induced by environmental agents. Although the cost of inherited diseases to the national economy may be lower than that caused by diseases of infectious or nutritional origin, inherited diseases may be economically important, particularly to individual breeders. Certain genetically caused diseases may spread insidiously through a breed until they are difficult to control economically. It is therefore highly desirable that diseases with a genetic basis be recognized at an early stage and control measures instigated. Apart from the economic aspects of inherited diseases, they may be important as experimental models for the study of similar diseases in man. 相似文献
100.
The specialised histology and anatomy of the central nervous system (CNS) is reflected in its pathology. This is particularly so for the perivenular/periarterial spaces in which inflammatory cells accumulate in inflammation. These spaces, although structurally not lymphatics, act as lymphatics draining fluid from brain to subarachnoid space and to lymphatics draining to deep cervical lymph nodes. Inflammatory cells may enter or leave the CNS by this route. In immune-based inflammation, they are colonised by subsets of immune cells allowing the processing of antigen, synthesis of antibody and development of cell mediated immune reactions. 相似文献