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21.
Frdric Billen DVM Nicole Van Israël DVM CertVC MSc Dipl ECVIM 《Journal of Veterinary Cardiology》2006,8(1):63-68
This case report describes transient atrioventricular block as the etiology for syncopal events in a 6-year-old male German shepherd dog with atrial fibrillation and dilated cardiomyopathy. The arrhythmia diagnosis was obtained via Holter monitoring. Medical treatment with a sustained-release preparation of theophylline, as an additive to the standard congestive heart failure treatment (benazepril, furosemide and pimobendan) may have contributed to temporary remission of the syncopal events. However, the congestive heart failure progressed and the dog was euthanized. Veterinarians should be aware of the possibility of transient atrioventricular block causing syncope in dogs with DCM and AF and should be careful in empirically lowering the ventricular response rate if these dogs present with syncopal episodes. 相似文献
22.
Nicole Schneider Marianne Heimann Jean-Philippe Lejeune Denis R.V.G. Verwilghen Ginette P. Deby-Dupont Didier A. Serteyn 《Journal of veterinary science (Suw?n-si, Korea)》2006,7(1):83-85
In the human and equine species, different kinds of free floating intra-articular particles are related to certain disorders. Osteochondral fragments formed during osteochondrosis dissecans are the most common finding in the equine species, whereas in humans rice bodies due to rheumatoid arthritis are more frequent. Herein we report a third type of floating body inside the stifle of an adult draught horse stallion, in macroscopic appearance similar to articular rice bodies known in humans. As revealed by histologic examination, the two particles consist of polypoid degenerated structures derived from synovial villi. Their formation was probably induced by ischemia. 相似文献
23.
ABSTRACT During gel (gum) formation in angiosperm trees, fibrillar material accumulated in protective layers of xylem parenchyma cells before being secreted across half-bordered pit membranes into vessel elements. Immunogold labeling demonstrated that this fibrillar material was mainly composed of partially esterified pectic polysaccharides. The primary wall of expanding tyloses, an extension of the parenchyma protective layer, secreted similar pectic substances to completely block vessel elements. In most studies, these occluding structures were reported to be formed in response to causative factors such as aging processes, injuries, or infections. Current observations support the view that partial to complete embolism, which almost always accompanies these factors, might be the main cause triggering the formation of vessel occlusions. Whereas pectin seems to be the basic component of gels (gums) and of the external layer of tyloses, other substances, such as phenols, were also detected either as a part of these plugs or as accumulations beside them in vessels. Finally, it is proposed that the term 'gel' instead of 'gum' be used in future studies to describe the occluding material secreted by ray and paratracheal parenchyma cells. 相似文献
24.
Dramatic declines in the endangered Columbia Basin pygmy rabbit, a genetically unique population of small, burrowing rabbits in Northwestern United States, are likely the combined results of habitat degradation and fragmentation, disease, and predation. A critical component of pygmy rabbit habitat includes big sagebrush (Artemisia tridentata), which constitutes 82-99% of their winter diet and 10-50% of their summer diet. Sagebrush also forms the bulk of hiding cover around burrow sites. Across the range of pygmy rabbits, sagebrush habitat is grazed extensively by cattle. However, grazing has unknown effects on pygmy rabbits inhabiting the remaining, fragmented shrub-steppe habitat. We evaluated the effects of four grazing treatments on the distribution of pygmy rabbit burrows, diets of pygmy rabbits, and quality and quantity of vegetation at Sagebrush Flat in central Washington. Ungrazed areas contained significantly more burrows per unit area than did grazed areas. Vegetation composition and structure differed little among treatments in early summer before annual grazing by cattle. However, cattle grazing in late summer through winter removed about 50% of the grass cover, and reduced the nutritional quality (e.g., increased fiber and decreased protein) of the remaining grass. Although pygmy rabbits ate <2% grasses in winter, grasses and forbs comprised 53% of late summer diets. Because these endangered rabbits avoided grazed areas, removing cattle grazing from key habitat locations may benefit efforts to restore this rabbit in Washington. 相似文献
25.
A cytochemical investigation was performed for studying cellulose alteration during phloem necrosis of the rubber tree. An exoglucanase-gold complex was used for localizing β-(1,4)-D-glucan linkages of non reducing ends of the polymer. Variation in cell wall labelling indicates that cellulose is degraded during this disease and suggests that cellulases are involved in this alteration. Wall appositions and periplasmic vesicles were also observed. 相似文献
26.
M. Nicole J. C. Thouvenel J. Giannotti H. Chrestin J. P. Geiger D. Nandris B. Rio 《Forest Pathology》1991,21(1):27-35
Phloem necrosis of rubber tree(hevea brasiliensis)is characterized by cel wall degradation, alteration of the middle lamella, the vesiculation of endomembranes, the formation of tylosoids and the internal coagulation of rubber. 相似文献
27.
Nicole?WellbrockEmail author Winfried?Riek Barbara?Wolff 《European Journal of Forest Research》2005,124(4):261-271
Based on the results of the atmospheric deposition classification of the year 1989, a methodical approach should be introduced,
which—based on the modelled total deposition rates—enables us to characterise the input situation of forest monitoring plots
and to delimit load areas in Germany. In 1989, the deposition situation in nearly 1,800 forest monitoring sites (BZE/extensive
Soil Condition Inventory) in Germany could be explained by four factors (or three, excluding sea salt impact) with the help
of a factor analysis. The factor values were grouped into six deposition types with typical compounds and regional patterns.
The classified input rates of the soil inventory plots adequately represent the stress situation and deposition changes in
Germany. The application of the statistical approach on the level of Brandenburg clarifies the special local input situation.
Due to the special combination of deposed elements, the sources of emissions can be characterised as well. When the soil inventory
is repeated, a project planned for 2006, this approach can be used in order to determine homogenous areas for stratified data
evaluation. 相似文献
28.
A study on biochemical mechanisms of the rubber tree aggression by two root rotting fungi Rigidoporus lignosus and Phellinus noxius was carried out. The activity of eight enzymes and their spatial distribution in adult tap root tissues were measured. Finally their origin, host or parasite, and physiological signification in the pathogenic process were discussed. 相似文献
29.
Sabine Augustin Jan Evers Hans-Peter Dietrich Johannes Eichhorn Thomas Haussmann Regina Icke Ansgar Isenberg Wolfgang Lux Monica Musio Hans Pretzsch Winfried Riek Thomas Rötzer Bernd Schultze Andreas Schulze Jörg Schröder Walter Seidling Nicole Wellbrock Klaus von Wilpert Barbara Wolff 《European Journal of Forest Research》2005,124(4):251-260
In the 1970s unexpected forest damages, called “new type of forest damage” or “forest decline”, were observed in Germany and
other European countries. The Federal Republic of Germany and the German Federal States implemented a forest monitoring system
in the early 1980s, in order to monitor and assess the forest condition. Due to the growing public awareness of possible adverse
effects of air pollution on forests, in 1985 the ICP Forests was launched under the convention on long-range transboundary
air pollution (CLRTAP) of the United Nations Economic Commission for Europe (UN-ECE). The German experience in forest monitoring
was a base for the implementation of the European monitoring system. In 2001 the interdisciplinary case study “concept and
feasibility study for the integrated evaluation of environmental monitoring data in forests”, funded by the German Federal
Ministry of Education and Research, concentrated on in-depths evaluations of the German data of forest monitoring. The objectives
of the study were: (a) a reliable assessment of the vitality and functioning of forest ecosystems, (b) the identification
and quantification of factors influencing forest vitality, and (c) the clarification of cause-effect-relationships leading
to leaf/needle loss. For these purposes additional data from external sources were acquired: climate and deposition, for selected
level I plots tree growth data, as well as data on groundwater quality. The results show that in particular time series analysis
(crown condition, tree growth, and tree ring analysis), in combination with climate and deposition are valuable and informative,
as well as integrated evaluation of soil, tree nutrition and crown condition data. Methods to combine information from the
extensive and the intensive monitoring, and to transfer process information to the large scale should be elaborated in future.
相似文献
Sabine AugustinEmail: |
30.
We investigated tree water relations in a lower tropical montane rain forest at 1950-1975 m a.s.l. in southern Ecuador. During two field campaigns, sap flow measurements (Granier-type) were carried out on 16 trees (14 species) differing in size and position within the forest stand. Stomatal conductance (g(s)) and leaf transpiration (E(l)) were measured on five canopy trees and 10 understory plants. Atmospheric coupling of stomatal transpiration was good (decoupling coefficient Omega = 0.25-0.43), but the response of g(s) and E(l) to the atmospheric environment appeared to be weak as a result of the offsetting effects of vapor pressure deficit (VPD) and photosynthetic photon flux (PPF) on g(s). In contrast, sap flow (F) followed these atmospheric parameters more precisely. Daily F depended chiefly on PPF sums, whereas on short time scales, VPD impeded transpiration when it exceeded a value of 1-1.2 kPa. This indicates an upper limit to transpiration in the investigated trees, even when soil water supply was not limiting. Mean g(s) was 165 mmol m(-2) s(-1) for the canopy trees and about 90 mmol m(-2) s(-1) for the understory species, but leaf-to-leaf as well as tree-to-tree variation was large. Considering whole-plant water use, variation in the daily course of F was more pronounced among trees differing in size and crown status than among species. Daily F increased sharply with stem diameter and tree height, and ranged between 80 and 120 kg day(-1) for dominant canopy trees, but was typically well below 10 kg day(-1) for intermediate and suppressed trees of the forest interior. 相似文献