Hypokalaemic episodic polymyopathy in cats fed a vegetarian diet

A previously undocumented hypokalaemic condition with a cyclical nature, comprising acute bouts of polymyopathy followed by spontaneous recoveries, is described in the cat. Cats being fed a high protein vegetarian diet developed recurrent episodes of polymyopathy, characterised by ventroflexion of the head and neck, stiff forelimb gait, lateral head-resting and generalised muscle weakness. Plasma potassium concentrations (mean +/- standard deviation) were reduced from 3.28 +/- 0.33 mmol/l at the beginning of the experiment to 2.45 +/- 0.24 mmol/l during bouts of myopathy. This hypokalaemia was associated with increased creatine kinase activities indicative of muscle damage, and decreased urinary potassium concentrations, and was caused by insufficient dietary potassium. Cats that received the same diet supplemented with potassium did not develop hypokalaemic polymyopathy. Spontaneous recoveries of affected cats were not associated consistently with increases in plasma potassium concentrations. Plasma taurine concentrations decreased and glutamic acid increased markedly in all cats fed the experimental diet. There was no evidence of thiamin deficiency associated with the high glutamic acid intake. Veterinarians should be aware that hypokalaemic cats, and in particular those on potassium-deficient diets, may show cyclical disease with episodes of polymyopathy recurring after periods of spontaneous clinical recovery. This condition in cats may be a useful animal model for familial hypokalaemic periodic paralysis in humans.     

Organic matrix morphology and distribution in the palisade layer of eggshells sampled at selected periods during lay

1. 1 cm2 pieces of eggshells from a commercial battery flock were plasma etched to remove the outer shell membranes. 2. They were decalcified using EDTA (200 g/l, pH 6.9 to 7.0) in paraformaldehyde (20 g/l) and 25% gluteraldehyde (20 ml in 0.98 l) in phosphate buffer, then prepared for light and transmission electron microscopy. 3. Light microscopy revealed a differential distribution of matrix material within all 3 regions of the palisade layer at the beginning of lay. 4. Transmission electron microscopy revealed a more even distribution of matrix at the beginning of lay, although morphological differences were observed. At the end of lay all 3 regions showed an increase in % matrix and vesicles/10 cm2 of micrograph compared to the middle and beginning of lay periods. 5. It is hypothesised that matrix vesicles are involved in the regulation of the physiochemical environment within the forming eggshell and that the decline in shell quality associated with the end of lay is related to a concomitant change in matrix quality.     

Blackleg development and tuber yield in relation to numbers of Erwinia carotovora subsp. atroseptica on seed potatoes

The relationship between number of viable cells of Erwinia carotovora subsp. atroseptica on inoculated potato seed tubers and blackleg development was investigated in 2 years for five cultivars grown in the contrasting climates of Scotland and Israel. Blackleg, and to a lesser extent non-emergence, increased with higher numbers of bacteria on the seed tubers at planting. This relationship was also found for several commercial seed stocks of one cultivar naturally contaminated with different numbers of E. carotovora subsp. atroseptica.The threshold number of bacteria necessary for the development of blackleg declined during the growing season and was also higher for the cultivar Pentland Crown in comparison with the others. In general, yield declined linearly with blackleg incidence and there was a 0.8% reduction in yield for every 1 % blackleg at 13 weeks after planting. Yield loss was positively related to the incidence of blackleg late in the season, whereas the relationship between yield loss and the incidence of non-emergence was poor.     

THE WEATHERING OF CHLORITIC MINERALS IN SOME SCOTTISH SOILS

The mineralogy of 14 chloritic soils of various drainage classes developed on different parent materials from the Loch Awe area of Argyllshire, Caithness, and the Southern Uplands reveals only minor variations'in clay mineralogy with profile depth, the frequent presence of primary minerals indicating that all the soils are immature, and that weathering is at an early stage. Iron-rich chlorite generally persists throughout the profiles, varying little in amount or chemical composition between horizons; where identifiable, the polytype is II b. Oxidation of iron modifies the thermal characteristics of the chlorite in all the freely-drained soils but usually only in the surface horizons of gleys. Irrespective of soil type or drainage class, in most profiles chlorite weathers only slightly, probably by vermiculitization around the edges of flakes.     

Methods of testing potato cultivars for resistance to soft rot of tubers caused by Erwinia carotovora subsp. atroseptica

The resistance of eight potato cultivars to tuber soft rot caused by E. carotovora subsp. atroseptica was assessed in 2 years using three different test methods. Similar cultivar resistance rankings were obtained for any one method within a year and between years for two methods (single site, infectivity titration), but not for the third (vacuum infiltration). However, the ranking of cultivars differed for the three methods. Ranking was not affected by inoculating the cortex or the more susceptible medullary tissue, or by assessing rotting in terms of infection frequency or lesion size, but it was affected by oxygen concentration during incubation. Differences among cultivars were greater when inoculated tubers were incubated anaerobically than when incubated with 5% oxygen. There was no relationship between the relative susceptibilities of cultivars to tuber soft rot in storage in January/February and those of mother tubers after planting.     

举生态和民生大旗 走甘肃特色林业发展之路

多年来，甘肃省林业建设坚持以科学发展观为指导，按照发展现代林业、建设生态文明的要求，把生态建设和环境保护作为一项重大战略任务，坚持生态建设和改善民生并重的林业发展理念，努力探索形式多样的林业产业发展模式，创新生态建设机制，构建科技支撑体系，走出了一条具有甘肃特色的林业发展道路，林业建设保持了良好的发展态势，取得了显著成效。但是，受历史、自然、现实等多种因素影响，甘肃特色林业发展仍面临着诸多困难和问题。针对当前甘肃省特色林业发展中遇到的主要矛盾与困难，建议进一步转变林业发展观念，采取一系列有效措施，生态与民生兼顾，促进社会和谐进步。     

A TITANIUM-RICH SOIL CLAY

A peaty podzol developed on glacial drift derived from chlorite-schists near Loch Awe, Argyll, contains up to 25 per cent titanium dioxide in the clay fractions after removal of organic matter and free iron oxides. Electron microscopy reveals that this titanium is almost entirely in the form of cryptocrystalline anatase which is amorphous to X-rays and which is removed by the HF method normally used to concentrate anatase and rutile in soils. The anatase has probably formed as a result of the weathering of sphene.     

蛋壳品质评估的研究进展和应用前景

工业化生产中有8%～10%的蛋在日常操作中存在蛋壳损坏的问题。1995年Hunton报道指出平均产蛋量为288个的10万只鸡群,每增加1%的破壳蛋,这个鸡场年收入就会减少10,000美元。因此,破壳蛋就成了鸡蛋产量和销售的主要经济影响因素,如果破壳蛋通过检测系统而未被识别,还会影响食品的安全性。在日常操作过程中减少破壳蛋已经取得了相当大的成效,我们可以在包装部门对破壳蛋进行在线检测,并且对蛋壳品质特别是蛋壳强度进行评估和改善。最近,DeKetelaere等(2004)重述了现代化的非破坏性传感器技术,该技术普遍应用于禽蛋的联机分级,因此本文不再详述。本文集中描述了对蛋壳品质进行评估的新方法,以及在将来如何把这些技术应用于实际家禽育种计划。     

Acute myelogenous leukaemia in a mare

SUMMARY: A 5-year-old Thoroughbred mare presented with a 4 week history of weight loss, fever and leukopenia. Rectally, a large active foetus, thickened spleen and an abdominal mass were palpated. Leukopenia, mild anaemia, marked thrombocytopenia and hyperfibrinogenaemia were found. Cytology and cytochemical staining of a bone marrow aspirate supported a diagnosis of acute myelogenous leukaemia. The mare deteriorated despite medical therapy and was humanely euthanased.