Evidence-Based Equine Nutrition     

Sarah L. Ralston 《Veterinary Clinics of North America: Equine Practice》2007

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Ecological Issues in a Changing World     

Sarah Goslee 《Landscape Ecology》2006,21(4):629-630

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Testing assumptions of cost surface analysis—a tool for invasive species management   总被引：1，自引：0，他引：1  

Emily K. Gonzales  Sarah E. Gergel 《Landscape Ecology》2007,22(8):1155-1168

Applied ecology could benefit from new tools that identify potential movement pathways of invasive species, particularly where data are sparse. Cost surface analysis (CSA) estimates the permeability (friction) across a landscape and can be applied to dispersal modelling. Increasingly used in a diversity of applications, several fundamental assumptions that might influence the outputs of CSA (cost surfaces and least-cost pathways) have yet to be systematically examined. Thus, we explore two issues: the presumed relationship between habitat preferences and dispersal behaviour as well as the degree of landscape fragmentation through which an organism moves by modelling a total of 18 sensitivity and dispersal scenarios. We explored the effect of fragmentation by altering the friction values (generally assigned using expert opinion) associated with patch and linear features. We compared these sensitivity scenarios in two sites that differed in fragmentation. We also used eastern grey squirrels (Sciurus carolinensis) as an example invading species and compared diffusion models and two contrasting cost surface dispersal scenarios. The diffusion model underestimated spread because squirrels did not move randomly through the landscape. Despite contrasting assumptions regarding dispersal behaviour, the two cost surfaces were strikingly similar while the least-cost paths differed. Furthermore, while the cost surfaces were insensitive to changes in friction values for linear features, they were sensitive to assumptions made for patch features. Our results suggest that movement in fragmented landscapes may be more sensitive to assumptions regarding friction values than contiguous landscapes. Thus, the reliability of CSA may depend not only on the range of friction values used for patches but also the degree of contiguity in the landscape.  相似文献   

The spore coat of the bean anthracnose fungus Colletotrichum lindemuthianum is required for adhesion, appressorium development and pathogenicity     

Sarah L. Rawlings  Richard J. O&#x;Connell  Jonathan R. Green 《Physiological and Molecular Plant Pathology》2007,70(4-6):110-119

The spores (conidia) of the bean anthracnose fungal pathogen, Colletotrichum lindemuthianum, adhere to the aerial parts of plants to initiate the infection process. In previous studies we have shown that the Colletotrichum spores are surrounded by a fibrillar spore coat, comprising several major glycoproteins. Previous evidence showed that a monoclonal antibody (UB20) that recognised these glycoproteins was able to inhibit adhesion of spores to a hydrophobic surface. In this paper we have further studied the role of the spore coat in adhesion, germination and fungal development by studying the effects of UB20 and protease treatment of spores. The latter treatment has previously been shown to remove the spore coat. Spores germinate on glass, polystyrene and water agar, however, appressoria only develop on glass or polystyrene, showing a requirement for a hard surface. Removal of the spore coat with protease inhibits adhesion at 30 min, before the secretion of ECM glycoproteins. Protease treatment also inhibits the development of appressoria and reduces pathogenicity on leaves. Incubation of spores with the MAb UB20 inhibits adhesion at 30 min, but does not affect appressorium formation or pathogenicity. The results suggest that an intact spore coat has two functions; it is required for adhesion to a hydrophobic surface and for the detection of a hard surface necessary for appressorium formation. We suggest that contact with a hard surface, rather than adhesion, is the key event leading to appressorium formation.  相似文献   

Density and Organic Matter Influence on Egg‐laying and Hatching of Branchiura sowerbyi (Oligochaeta)     

Karine Cristiane Rech  Renata Maria Guereschi  Alex Pires de Oliveira Nuñer  Sarah Carvalho Sticca 《Journal of the World Aquaculture Society》2013,44(2):267-272

This study aimed to assess the combined effects of density of adults of Branchiura sowerbyi and the source of organic matter on the production of eggs and young species. The experimental units used were 250‐mL beakers with 100 mL of fine sand (0.074–0.210 mm) and 150 mL of chlorine‐free water with constant aeration at the temperature 25 C. The experiment was conducted based on a two‐factor model with six treatments and three repetitions, applied in a completely random design. The densities 5 individuals/38.5cm² (D5; 1298/m²) and 8 individuals/38.5cm² (D8; 2078/m²) were assessed with commercial fish feed (FF), commercial poultry feed (PF), and turkey manure (TM) as sources of organic matter. A total of 1223 cocoons and 2138 eggs were produced, with average hatching of 40.0 ± 15.1%. The highest number of cocoons and eggs was found with the use of PF, D8 having produced the highest number of cocoons and eggs. The hatching rate was not influenced by the source of organic matter or density and no influence was registered from the density of adults on the survival. The PF provided the highest growth of adults, and generally the use of TM provided the worst performance.  相似文献   

Mild to moderate overweight in dogs: is there an impact on routine hematological and biochemical profiles,echocardiographic parameters and cardiac autonomic modulation?     

Vieira  Aline Bomfim  Restrepo  Mariana Alvarez  Auzenne  Danielle  Molina  Kevin  O’Sullivan  Meghan  Machado  Marcus Vinicius  Cavanaugh  Sarah Marie 《Veterinary research communications》2022,46(2):527-535

Veterinary Research Communications - Obesity is considered the most common nutritional disease of dogs. Even though overt obesity is more likely to impair health, even moderately overweight dogs...  相似文献   

Evaluation of Bacterial Effects on Folic Acid Loss in Fortified,Nixtamalized Corn Masa Flour     

Stephen J. Adolphson  Michael L. Dunn  Sarah Nielsen‐Barrows  Dennis L. Eggett  Frost M. Steele 《Cereal Chemistry》2016,93(5):508-512

Many Mexican women are deficient in folic acid. Fortification of the corn tortilla could be an effective way to help increase the folic acid levels among the Mexican population. Previous studies have shown significant folic acid losses in the masa dough as it is held before baking. This loss in folic acid could be owing to utilization by lactic acid bacteria naturally present in the masa. The objective of this study was to determine the effect of bacteria native to corn masa on the folic acid content in masa. Bacteria in dough samples from six mills in Guadalajara, Mexico, were isolated and identified. Bacterial isolates were inoculated into sterile fortified corn masa flour, which was converted to masa and held at 56°C for 0, 3, and 6 h, replicating the conditions of freshly milled masa as held before baking. All samples, including the control, showed losses of folic acid between 66 and 79% w/w in the first 3 h of incubation. Because folic acid degradation in the sterile control sample was not different than the inoculated sample results, the decline in folic acid was not owing to bacteria (mainly Streptococcus spp.) present in the masa flour but appeared to be a chemical degradation related to time and temperature.  相似文献   

Expanding opportunities for agroforestry education in the U.S. and Canadian universities     

Sarah T. Warren  William R. Bentley 《Agroforestry Systems》1990,12(1):115-120

A telephone survey of 39 U.S. and Canadian University forestry schools accredited with the Society of American Foresters, conducted in November 1988, showed that 25 had courses in tropical and international forestry, and 14 university faculties had been conducting research in agroforestry. Field-oriented training in agroforestry is also offered in North America, especially for voluntary and relief organization personnel. Many of the agroforestry courses have been established recently in response to desires of students with international interests and/or experience. Most of such courses are integrated programs, initiated by forestry faculty, and most of these are seminars or colloquia incorporating the experience of both faculty and students with focus on systems and issues rather than technical proceses. Ideas for agroforestry course content offered by North American forestry faculty include: integration of social and technical aspects of agroforestry and social forestry, involvement of multidisciplinary teams, focus on managing marginal, lands and consideration of the importance of agroforestry systems in North America and other temperate zones.  相似文献   

Crystallinity of wood and the size of cellulose crystallites in Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis>)   总被引：5，自引：0，他引：5  

Seppo?Andersson  Ritva?SerimaaEmail author  Timo?Paakkari  Pekka?Saranp??  Erkki?Pesonen 《Journal of Wood Science》2003,49(6):531-537

X-ray diffraction was used to study variations in the crystallinity of wood and the average thickness and length of the crystallites of cellulose as a function of the number of the year ring in Norway spruce [Picea abies (L.) Karst.]. The crystallinity increased from ring 4 to ring 10 from the pith and was constant after ring 10. The crystallinity of mature wood was about 30% ± 5%. The average thickness and average length of the crystallites were 3.2 ± 0.1nm and 28 ± 2nm, respectively; and no systematic variation of these values with the number of the year ring was observed. The mean microfibril angle decreased near the pith but was constant in the mature wood.  相似文献   

Evaluation of the Diagnostic Accuracy of Conventional 2‐Dimensional and 3‐Dimensional Computed Tomography for Assessing Canine Sacral and Pelvic Fractures by Radiologists,Orthopedic Surgeons,and Veterinary Medical Students          下载免费PDF全文

Sri Kumar Jamie Senthirajah BS  Sarah Nemanic DVM  PhD  Diplomate ACVR  Wendy Baltzer DVM  PhD  Diplomate ACVS  Jennifer Warnock DVM  PhD  Diplomate ACVS  Katelyn Hollars BS  Scott S. Lee  Gerd Bobe PhD 《Veterinary surgery : VS》2015,44(6):694-703

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