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51.
Pancreatic disorders in dogs and cats are recognized with increasing frequency, and abdominal ultrasonography has assumed an important role in their diagnosis. The normal pancreas is a small, inconspicuous organ of comparable echogenicity to surrounding mesentery and may be difficult to identify. Therefore, knowledge of anatomic landmarks such as portal vein and contributing vessels, duodenum, and stomach is necessary to facilitate identification and examination. Pancreatic diseases and abnormalities frequently investigated by means of ultrasonography include pancreatitis, pseudocysts, abscesses, neoplastic lesions, and nodular hyperplasia. Disorders less commonly seen include exocrine pancreatic insufficiency, pancreatolithiasis, congenital anomalies, and pancreatic edema. Unfortunately, ultrasonographic findings in various pancreatic disorders overlap, and incidental findings or age-related changes may mimic pancreatic disease. On the other hand, pancreatic disorders may not cause changes in ultrasonographic appearance. Ultrasonographic findings, therefore, have to be judged in light of signalment, history, and laboratory data. Cytology or histopathology may be needed to establish a definite diagnosis. Despite these limitations, ultrasonography is useful in diagnosing pancreatic disease, guiding aspirates and biopsies, and monitoring response to treatment.  相似文献   
52.
荷兰瓦格林根大学园艺所通过对水果和盆栽植物在温和性气候下的生长研究,发现散射光对作物生长有一定的促进作用. 温室中散射光的制造和使用在位于赤道附近的国家中已经非常普遍.种植者使用特殊的,可以制造散射光的塑料薄膜来提高种植产量,同时避免灼伤作物.散射光意味着光向各个方向分散,同时在一个区域内是均匀分布.  相似文献   
53.
Trefoil factors (TFF) are small peptides produced by goblet cells, which are crucial for epithelial restitution. In humans with inflammatory bowel disease (IBD), TFF expression is up-regulated as part of an unspecific repair mechanism. The goal of this study was to assess TFF gene expression in the gastrointestinal tract from dogs with IBD compared to healthy controls. Preliminary assessment by PCR revealed TFF1 and 3 expression in the small and large intestine, whereas TFF2 was amplified only in the stomach. Subsequent RT-qPCR (with relative quantification against 3 reference genes) on endoscopic duodenal (IBD n = 22, healthy controls n = 18) and colonic (IBD n = 12, controls n = 11) biopsies revealed that TFF1 expression was significantly up-regulated in the duodenum from IBD dogs (Mann–Whitney p = 0.001), whereas TFF3 expression was significantly lower in IBD colon compared to controls (t-test p = 0.018).This study demonstrates evidence for dysregulation of TFF gene expression in canine IBD. Up-regulation of TFF1 could signify ectopic expression as a compensatory repair-mechanism, whereas down-regulation of TFF3 could contribute to defective epithelial barrier function, respectively. Whether this is a cause or consequence of IBD could not be established.  相似文献   
54.
Effective teaching of veterinary radiology can be challenging in a traditional classroom environment. Audience response systems, colloquially known as “clickers,” provide a means of encouraging student interaction. The purpose of this study was to compare student performance and course evaluations before and after using the Classroom Performance System? in the third‐year (fifth semester) didactic radiology course at the University of Tennessee College of Veterinary Medicine. Overall student performance was assessed by comparing median numeric final course grades (%) between years without and with use of the Classroom Performance System?. Grades of students were determined for individual instructors’ sections. Student evaluations of the radiology course were compared for the years available (2007–2010). Student interactions were also evaluated subjectively by instructors who used the Classroom Performance System?. There was a significant difference (p = 0.009) between the median student grade before (2005 – 2008, median 82.2%; interquartile range 77.6–85.7%; range 61.9–95.5%) and after use of the classroom performance system (2009–2010, median 83.6%; interquartile range 79.9–87.9%; range 68.2–93.2%). There was no statistically significant difference in median student grades for individual instructors over the study period. The radiology course student evaluation scores were significantly higher in years where the Classroom Performance System? was used in comparison to previous years (P = 0.019). Subjectively, students appeared more involved when using clickers. Findings indicated that the Classroom Performance System? may be a useful tool for enhancing veterinary radiology education.  相似文献   
55.
The Institute for Strategies and Technology Assessment of the Julius Kühn-Institute operates four different networks: demonstration farms on IPM, reference farms for plant protection, panel pesticide applications and NEPTUN farms. All networks deal with the use of plant protection products in agricultural practice. The latter three also have very similar tasks and are closely interlinked. As a result, outsiders have significant problems distinguishing between those four farm networks and assigning the respective activities to the “right” corresponding network.Therefore, the publication aims at presenting comparatively the tasks and objectives of the various networks and to explain to the reader what are they doing, what are the differences, as well as why and how the establishment of these four different farm networks has come about.  相似文献   
56.
Like many fields of the biosciences, actinomycete natural products research has been revolutionised by next-generation DNA sequencing (NGS). Hundreds of new genome sequences from actinobacteria are made public every year, many of them as a result of projects aimed at identifying new natural products and their biosynthetic pathways through genome mining. Advances in these technologies in the last five years have meant not only a reduction in the cost of whole genome sequencing, but also a substantial increase in the quality of the data, having moved from obtaining a draft genome sequence comprised of several hundred short contigs, sometimes of doubtful reliability, to the possibility of obtaining an almost complete and accurate chromosome sequence in a single contig, allowing a detailed study of gene clusters and the design of strategies for refactoring and full gene cluster synthesis. The impact that these technologies are having in the discovery and study of natural products from actinobacteria, including those from the marine environment, is only starting to be realised. In this review we provide a historical perspective of the field, analyse the strengths and limitations of the most relevant technologies, and share the insights acquired during our genome mining projects.  相似文献   
57.
58.
The aim of this study was to investigate how long‐term Mancozeb application to banana plantations affects the occurrence of pollutants in drainage‐channel sediment and water under tropical conditions. We estimated the possible accumulation of Mancozeb's principal metabolite ethylenethiourea (ETU), as well as manganese (Mn) and zinc (Zn) as components in channel sediment and water. We took samples during the tropical‐rainfall season and the low‐rainfall season. For sediment samples, we determined the contents of ETU, Mn, and Zn. For water samples, we determined the concentration of ETU. Additionally, we took water samples from a runnel that is the receiving body of hydraulic flow from the system. In both seasons, ETU in the sediment was near the detection limit (0.01 mg kg–1) and did not show any accumulation. However, Mn in sediment at all sampling sites exceeded the threshold values for aquatic life of 630 mg kg–1 with values between 635 and 7256 mg kg–1. The Zn concentrations in sediment varied from 87 to 190 mg kg–1 and exceeded the threshold values for aquatic life of 98 mg kg–1 at several sites. Furthermore, we determined an accumulation of these heavy metals in the sediments of the banana‐planted zone in comparison with sediments in pasture reference sites. In contrast to the low concentration of ETU in sediment, its concentration in drainage and runnel water (5.9–13.8 μg L–1) exceeded the EU threshold value for drinking water (0.1 μg L–1) by up to nearly 140 times. However, the threshold value for aquatic life was not exceeded. We conclude that long‐term Mancozeb application does lead to a severe accumulation of Mn in sediments and of ETU in surface water. New strategies should be used to control black Sigatoka, including integrated methods of pest control so that long‐term negative effects on the environment can be avoided.  相似文献   
59.
微藻在生态系统的结构和功能中具有极为重要的作用,而传统光学人工镜检方法对微藻种类鉴别具有较大的难度。本研究将微藻的光学图像进行了采样,并结合国内外专家对微藻鉴定的经验知识,制作了微藻图像数据集,并进行了数据增强处理。借助深度学习的原理和方法,构建了基于卷积神经网络结构的深度学习模型(AlexNet),对模型进行了训练,并利用5折交叉验证方法确保模型的稳定性。结果表明,模型的训练精度可达到98.78±0.98%,测试精度达85.46±0.23%,达到了预期效果。利用AlexNet模型训练得到的参数,对预留的280个样本图像进行实际测试,7个藻种的平均精确度、平均召回率和平均F1 Score分别为0.832,0.844和0.833。表明深度学习方法是鉴定微藻的一种有效方法。  相似文献   
60.
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