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301.
Corneal esthesiometry in the healthy horse   总被引:1,自引:1,他引:0  
Objective To determine corneal sensitivity in healthy adult horses in order to establish reference values. Animals studied One hundred eyes of 50 healthy adult horses. Procedure Corneal sensitivity was determined by evaluating the corneal touch threshold (CTT) in five different corneal regions using a Cochet‐Bonnet esthesiometer. Results Comparing CTT values (in mm filament length) of the five prescribed corneal regions revealed regional variations in corneal sensitivity, with the central region (21.15 ± 6.23 mm) being the most sensitive, followed by the nasal (20.75 ± 5.14 mm), temporal (20.70 ± 5.37 mm), ventral (20.15 ± 5.88 mm) and dorsal (15.85 ± 3.70 mm) region. However, differences between the central, nasal, temporal and ventral regions were not statistically significant, whereas the dorsal region was significantly (P < 0.0001) less sensitive compared to the other regions. Division of the horses into three age groups revealed an insignificant decrease in corneal sensitivity with age in the nasal, temporal, ventral and central region, and an insignificant increase with age in the dorsal region. Correlation of corneal sensitivity with age was statistically significant in the central, ventral and temporal region. No statistically significant difference in the CTT was found between left and right eyes and between males and females. Conclusions CTT values in 100 eyes of 50 healthy adult horses evaluated with a Cochet‐Bonnet esthesiometer generated reference values. Reference values are necessary to determine alterations of corneal sensation accompanying various eye diseases or systemic diseases.  相似文献   
302.
Occurrence of Agriotes wireworms in Austrian agricultural land   总被引:2,自引:0,他引:2  
Agriotes wireworms (Coleoptera: Elateridae) are abundant soil-dwelling herbivores which can inflict considerable damage to field crops. In Europe up to 40 species occur, differing in their ecology and pest status. Their distribution in the larval stage, however, has rarely been assessed because of the considerable effort in collecting wireworms and the difficulties in identifying them to species-level. Here, we examined the occurrence of Agriotes wireworms in Austrian agricultural land with regard to their association with climatic and soil parameters. Using a molecular identification system, 1348 field-collected larvae from 85 sites were identified to species-level. Three species, Agriotes obscurus, Agriotes brevis, Agriotes ustulatus, and two that could not be discerned molecularly (Agriotes lineatus and Agriotes proximus), were assigned to two ecological groups: (i) A. brevis/A. ustulatus, found in areas with a warmer, drier climate and alkaline soils, and (ii) A. obscurus/A. lineatus/proximus which occur mainly at higher altitude characterised by lower temperatures, higher precipitation and acidic, humus-rich soils. Agriotes sputator was abundant throughout Austria, confirming its euryoecious nature. Only one larva of Agriotes litigiosus was found, prohibiting further analysis. These data contribute to a characterisation of species-specific traits in Agriotes larvae in agricultural land, an important prerequisite to develop efficient control strategies for these wireworms.  相似文献   
303.
Experimental forest plantations to study biodiversity–ecosystem functioning (BEF) relationships have recently been established in different regions of the world, but subtropical biomes have not been covered so far. Here, we report about the initial survivorship of 26 tree species in the first such experiment in subtropical China. In the context of the joint Sino–German–Swiss Research Unit “BEF-China,” 271 experimental forest plots were established using 24 naturally occurring tree species and two native commercial conifers. Based on the survival inventories carried out in November 2009 and June 2010, the overall survival rate was 87 % after the first 14 months. Generalized mixed-effects models showed that survival rates of seedlings were significantly affected by species richness, the species’ leaf habit (deciduous or evergreen), species identity, planting date, and altitude. In the first survey, seedling establishment success decreased with increasing richness levels, a tendency that disappeared in the second survey after replanting. Though evergreen species performed less well than deciduous species with establishment rates of 84 versus 93 % in the second survey, their planting success exceeded the general expectation for subtropical broad-leaved evergreen species. These results have important implications for establishing mixed-species plantations for diversity conservation and improvement of ecosystem functioning in the Chinese subtropics and elsewhere. Additional costs associated with mixed-species plantations as compared to conventional plantations also demonstrate the potential of upscaling BEF experiments to large-scale afforestation projects.  相似文献   
304.
OBJECTIVE: Recombinant feline interferon omega (rFeIFN-omega), a type I IFN, may have the potential to limit virus replication and associated clinical signs when administered early on in the course of feline herpesvirus type 1 (FHV-1) infection and reactivation, respectively. The effect of rFeIFN-omega pretreatment on the course of subsequent FHV-1 infection in cats was investigated. ANIMALS STUDIED: Nine SPF cats were divided into an IFN group (n = 5) and a control-group (n = 4). PROCEDURES: The IFN group was pretreated for 2 days with 10 000 units rFeIFN-omega twice a day topically into both eyes and 20 000 units rFeIFN-omega once a day orally, whereas the control group was mock-treated. Subsequently all cats were infected with FHV-1. Samples for FHV-1 DNA detection and quantitation, virus isolation, and titration of FHV-1 antibodies were collected. Clinical and ocular signs were recorded and scored. RESULTS: Courses of median individual clinical and ocular scores and virus load did not differ significantly between both groups using anova for repeated measurements. Analysis (anova) of each individual ocular parameter revealed significantly high scores for epithelial keratitis (P = 0.016) in the IFN group compared to the control group. Periods of virus shedding did not differ significantly between both groups using the Wilcoxon rank sum test. CONCLUSIONS: Results indicated a lack of beneficial effects of rFeIFN-omega pretreatment in the course of primary FHV-1 infection in cats.  相似文献   
305.
Earth's long-term sea-level history is characterized by widespread continental flooding in the Cretaceous period (approximately 145 to 65 million years ago), followed by gradual regression of inland seas. However, published estimates of the Late Cretaceous sea-level high differ by half an order of magnitude, from approximately 40 to approximately 250 meters above the present level. The low estimate is based on the stratigraphy of the New Jersey margin. By assimilating marine geophysical data into reconstructions of ancient ocean basins, we model a Late Cretaceous sea level that is 170 (85 to 270) meters higher than it is today. We use a mantle convection model to suggest that New Jersey subsided by 105 to 180 meters in the past 70 million years because of North America's westward passage over the subducted Farallon plate. This mechanism reconciles New Jersey margin-based sea-level estimates with ocean basin reconstructions.  相似文献   
306.
307.
在谷氨酸棒状杆菌乙酸盐代谢调控关键酶-异柠檬酸裂解酶aceA基因两段启动子区域后面组装了无启动子的β-半乳糖苷酶报道基因,并且带上四环素抗性标记基因构建了两个检测质粒pROH7 和pROHO.通过该两个质粒转化了谷氨酸棒状杆菌野生型菌株Corynebacterium glutamicum ACTT 14752,分别获得了含有两个检测质粒的两种谷氨酸棒状杆菌,由此建立了谷氨酸棒状杆菌在乙酸盐和葡萄糖基质上的两个蓝白生长筛选系统.结果显示当两种菌株生长在含有葡萄糖的基本培养基上时呈现白色菌落,而生长在含有乙酸盐的基本培养基上时呈现蓝色菌落;其中菌落颜色还随菌株中检测质粒pROH7 和pROHO的不同而呈现淡蓝色和深蓝色的变化.含有检测质粒pROH7 和pROHO菌落的颜色变化反映了细胞在葡萄糖和乙酸盐不同和碳源上的调控状态,该两个质粒在鉴定乙酸盐代谢中的调控变化方面是有积极意义.  相似文献   
308.

Purpose  

Biogeochemical interfaces, the 3D association of minerals, soil organic matter, and biota, are hotspots of soil processes because they exhibit strong biological, physical, and chemical gradients. Biogeochemical interfaces have thicknesses from nanometers to micrometers and separate bulk immobile phases from mobile liquid or gaseous phases. The aim of this contribution is to review advanced microscopic and spectroscopic characterization techniques that allow for spatially resolved analysis of composition and properties of biogeochemical interfaces or their visualization.  相似文献   
309.
Landscape Ecology - Understanding the variability and dynamics of ecosystems, as well as their responses to climate or land use change, is challenging for policy makers and natural resource...  相似文献   
310.
Metabolite transfer via enzyme-enzyme complexes   总被引:20,自引:0,他引:20  
The concentrations of enzyme sites in cells are usually higher than the concentrations of cognate intermediary metabolites. Therefore metabolic pathways or substantial segments of pathways may proceed by the direct transfer of metabolites from one enzyme site to the next by means of enzyme-enzyme complex formation. This mechanism of metabolite transfer differs from that usually assumed where dissociation and random diffusion of metabolite through the aqueous environment is responsible for the transfer to the next enzyme site. Since the direct transfer mechanism does not involve the aqueous environment, the energetics of metabolite interconversion can differ from expectations based on aqueous solution data. Evidence is summarized suggesting that metabolite is transformed and transferred with equal facility everywhere in the direct transfer pathway.  相似文献   
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