Adult-onset cerebellar cortical abiotrophy and retinal degeneration in a domestic shorthair cat.     

Georgina Barone  Polly Foureman  Alexander deLahunta 《Journal of the American Animal Hospital Association》2002,38(1):51-54

A 4-year-old, neutered male domestic shorthair cat presented for evaluation of ataxia and visual deficits. Neurological examination revealed severe cerebellar ataxia with symmetrical hypermetria and spasticity, a coarse whole-body tremor, positional vertical nystagmus, and frequent loss of balance. A menace response was absent bilaterally, and the pupils were widely dilated in room light. A funduscopic examination revealed markedly attenuated to absent retinal vessels and pronounced tapetal hyperreflectivity, findings consistent with end-stage retinal degeneration. Blood work evaluation included retroviral testing, a complete blood count, serum biochemistry analysis, taurine levels, and toxoplasma immunoglobulin G and immunoglobulin M titers. All were within reference ranges. The patient was euthanized, and a necropsy was performed. Microscopically, lesions of the nervous system were confined to the cerebellum and were consistent with cerebellar cortical abiotrophy. Selective photoreceptor degeneration was seen on histopathological examination of the retina with a reduction in the number of rods and cones. The combination of clinical findings and histopathological lesions seen here has not been previously reported in the cat.  相似文献   

Obituary     

Professor Sir Alexander Robertson CBE  MA  BSc  PhD  DVSc  LLD  FRCVS  FRSC  FRSE 《Tropical animal health and production》1991,23(1):1-1

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Effects of Superior Check Desmotomy on Flexor Tendon and Suspensory Ligament Strain in Equine Cadaver Limbs     

Guy R. Alexander  BVSc  Cert VR    Katherine T. Gibson  BVSc  MS  Diplomate ACVS    Robert E. Day  MBiomedEng  BEng  CPEng    Ian D. Robertson  BVSc  PhD  MACVSc 《Veterinary surgery : VS》2001,30(6):522-527

OBJECTIVE: To measure the effects of transection of the accessory ligament of the superficial digital flexor (SDF) muscle (superior check desmotomy) on flexor tendon and suspensory ligament (SL) strain in vitro. STUDY DESIGN: In vitro experimental biomechanical investigation. ANIMALS USED: Ten equine cadaver forelimbs. METHODS: The effects of superior check desmotomy were determined using equine cadaver forelimbs secured in a servocontrolled hydraulic testing machine. Strain sensors were used to measure strain on the superficial and deep digital flexor tendons and SL, and a goniometer was used to measure joint angles when the limb was loaded at 890 N and 3,115 N before desmotomy, and at 3,115 N after desmotomy. RESULTS: Superior check desmotomy was associated with significantly increased strains on the SDF tendon and SL, and significant alterations in the angles of the metacarpophalangeal and carpal joints. CONCLUSIONS: The superior check ligament has an important role in maintaining joint angles and load distribution in the forelimb. Lengthening of the SDF musculotendinous unit after superior check desmotomy may be associated with increased strain on the SL. CLINICAL RELEVANCE: Transection of the accessory ligament of the SDF muscle may predispose horses to SL desmitis postoperatively.  相似文献   

Integration of transgenes into sexual polyploidization schemes for potato (Solanum tuberosum L.)     

Alexander A.T. Johnson  Richard E. Veilleux 《Euphytica》2003,133(1):125-138

Most potato transgenic research has focused on development of resistance to pathogens and modification of potato physiology. Many transgenes, particularly those conferring pathogen resistance, could substantially lower potato production costs in developing countries. However, transgenes have not been reported in sexually propagated 4x-2x potato hybrids commonly grown in developing countries. Two transgenes,the Bacillus thuringiensis cry3Aa endotoxin protein gene and the PVY°coat protein gene, were engineered intodiploid and tetraploid potato using Agrobacterium tumefaciens-mediated transformation. Cry3Aa was produced at high levels in several lines while the PVY° coat protein was not expressed. Diplandroid and tetraploid genotypes were crossed to produce transgenic 4x-2x hybrids. Genetic transformation had no discernable effect on fertility ofthe primary transformants, germination of4x-2x seed derived from the transformants and agronomic performance(tuber set, average tuber weight and total tuber yield) of the 4x-2xhybrids. The transgenic 4x-2xhybrids produced non-viable pollen and could only be crossed as female parents. Results suggest that transgenes, such ascry3Aa, could be expressed in 4x-2x hybrids to lower costs of production with no significant effect on plant phenotype. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Allozymes and growth habit of Aegilops tauschii: genetic control and linkage patterns   总被引：1，自引：0，他引：1  

Alexander Ju. Dudnikov 《Euphytica》2003,129(1):89-97

Aegilops tauschii line of spring type growth habit with theearliest heading among all the VIR world germplasm collection of thisspecies was crossed with three Ae. tauschii lines of winter type growthhabit with low, intermediate and the highest vernalization requirement. 12enzyme loci were involved in genetic analysis. The growth habit was foundto be encoded by single codominant major gene, Vrn-D2. Thefollowing linkages were found: Est5 – Nadhd2 in chromosome 3, Vrn-D2 – Aco2 – Cat2 and Pgm – Nadhd1 in chromosome 4, Est2 – Got2 in chromosome 6.  相似文献   

Basics of effective erosion control in German agriculture     

Detlef Deumlich  Roger Funk  Monika Frielinghaus  Walter‐Alexander Schmidt  Olaf Nitzsche 《植物养料与土壤学杂志》2006,169(3):370-381

Present research in Germany on water, wind, and tillage erosion is examined. Existing soil‐protection strategies, laws, and guidelines are outlined. These are the result of extensive scientific investigations and the adoption of existing international knowledge. The most common methodologies currently used in Germany are reviewed. They allow an estimation of the water‐ and wind‐erosion risks as well as methods for their reduction. The results enable an aim‐orientated, site‐specific, risk‐adequate approach to implementing control measures in an easily understood framework. The most important remaining research problems are explained.  相似文献   

Scientific principles for water utilization in the U.S.S.R.     

Alexander M. Green 《Water, air, and soil pollution》1974,3(2):237-248

Water resources are essential for economic and cultural development of a territory. Both economic development and the health of the people depend on the provision of pure water. Scientifically founded plans of water resources use and conservation should be based on a balance approach to the assessment of available water supply sources and, on the forecast of their interconnected change in the future in a close association with the forecast of the whole economy and culture of the studied region. In the future the main threat to the normal development of the economy and life will not be water deficiency but the conversion of rivers, lakes and other water supply sources into sewers. Therefore it is proposed that there be a complete cessation of sewage discharge (even of the so-called purified) into water supply sources while drawing up long-term water management balances.  相似文献   

Effect of simulated acid rain on mycorrhizal infection of Pinus strobus L.     

H. F. Stroo  Martin Alexander 《Water, air, and soil pollution》1985,25(1):107-114

Mycorrhizal infection but not growth of white pine seedlings was reduced by application of simulated rain at pH 3.5 at 3 times ambient rates to plants grown in steamed Mardin soil inoculated with Pisolithus tinctorius. In unsteamed Mardin soil, the simulated acid rain at 3 times ambient rates had no effect on mycorrhizal infection or growth of pine seedlings if the rain was applied to the plants and soil or to only the soil before planting, except that nitrate-containing acid rain increased growth, infection and N content. In limed Mardin soil, the simulated acid rain reduced mycorrhizal infection if applied to the plants and soil as the seedlings were growing but not if applied to the soil before planting. Application of pH 3.5 rain at ambient rates had no detectable influence on mycorrhizal infection in 6 of 9 soils tested, but it stimulated infestion in 3 soils if the simulated rain contained only sulfate and in 1 soil if it had both sulfate and nitrate.  相似文献   

Callose concentration in leaves of field grown Oxalis acetosella (L.) indicates growth impediments     

Alexander H. Wissemeier  Hermann Rodenkirchen 《植物养料与土壤学杂志》1994,157(5):327-332

The Höglwald, located in Bavaria, is a pure Norway spruce stand, where experimental plots which were limed or not were subjected to normal or acid irrigation (Höglwald Experiment). The growth of the forest herb Oxalis acetosella improved greatly with liming. Callose concentration in leaves of Oxalis reflected the lime effect with about a 2.5 times lower callose concentration in the limed compared to unlimed plots. Acid irrigation increased callose concentration only in the unlimed plot. A negative exponential relationship was established between leaflet area and callose concentration. In a Diagnostic Field Fertilization Experiment in the vicinity of the Höglwald Experiment, Ca and Mg were applied either as carbonate or sulphate and Mn and Si added to experimental plots. In this experiment, it was demonstrated that it was not liming per se, but the application of Ca, that greatly increased the growth of Oxalis. Again, there was a negative correlation between leaflet area and callose concentration in leaves. Chemical analysis of leaves revealed that a Mn concentration > 3.5 mg (g DW)^?1 and a Mg concentration > 10 mg (g DW)^?1 led to increased callose concentration.  相似文献   

Arsenic-contaminated soils phytotoxicity studies with sunflower and sorghum     

Yelena V. Lyubun  Paul V. Kosterin  Elena A. Zakharova  Alexander A. Shcherbakov  Evgenii E. Fedorov 《Journal of Soils and Sediments》2002,2(3):143-147

Background, Aim and Scope  Environmental pollution caused by arsenic (As) is a major ecological problem. There has been intense worldwide effort to find As-hyperaccumulating plants that can be used in phytoremediation—the green-plant-assisted removal of chemical pollutants from soils. For phytoremediation, it is natural to prefer cultivated rather than wild plants, because their agriculture is well known. This study was conducted to evaluate the tolerance of common sunflower(Helianthus annuus L.) and sugar sorghum(Sorghum saccharatum Pers.) for soil-As contents of 10–100 mg As kg^-1 soil, with sodium arsenite as a model contaminant. Methods  Plants were grown in a growth chamber for 30 days. Microfield experiments were conducted on experimental plots. To study the phytoremediation effect of the auxins indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D), we treated 1- and 3-day-old plant seedlings with water solutions of the auxins (concentrations 10^-5, 10^-7, and 10^-9 g l^-1). The soil and plant-biomass samples were analyzed for total As by using the color reaction of ammonium molybdate with As. Results and Discussion  Phytotoxicity studies showed that 100 mg As kg^-1 soil poisoned sunflower and sorghum growth by 50%. There was a linear correlation between soil-As content and As accumulation in the plants. Laboratory experiments showed that the soil-As content was reduced two- to threefold after sunflower had been grown with 10–100 mg As kg^-1 soil for 30 days. Treatment of sunflower and sorghum seedlings with IAA and 2,4-D at a concentration of 10^-5 g l^-1 in microfield experiments enhanced the phytoremediation two- to fivefold as compared with untreated control plants. The best results were obtained with 3-day-old seedlings. Conclusion, Recommendation and Outlook  (a) Sunflower and sorghum are good candidates to remediate As-polluted soils. (b) Phytoremediation can be improved with IAA or 2,4-D. (c) Mixed cropping of sorghum and sunflower may be another way of improving phytoremediation.  相似文献