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51.
Alternative food ingredients, e.g. secondary plant compounds, are discussed to have beneficial effects and improve gut health. In this study, the effect of three different diets - normal piglets starter without additives, with apple pomace or with red-wine pomace - on the intestinal morphology was investigated from 3 days prior to weaning to 4 weeks post-weaning. At five time points, six piglets from each treatment group were slaughtered; at first time point only six animals from control group were slaughtered. Villus height, crypt depth and breadth of villi and crypts were determined in the jejunum, ileum and colon in 78 piglets. Additionally, the area of the Peyer's patches in the ileum was measured. In jejunum (p < 0.01) and ileum (p < 0.001) the villus length in the control group decreased after weaning but increased over the entire feeding experiment (p < 0.001). In the two-pomace groups, no decrease was measured after weaning. In jejunum, an increase in villi breadth occurred, 73% in the control group and approximately 10% in both treatment groups. A 35% increase was found in the ileum in all groups. Peyer's patches area increased approximately 21% in the control group over 26 days of treatment, whereas in other groups no significant differences were found. Different polyphenol rich pomaces have diverse effects in the gastrointestinal tract. Red-wine pomace has an inhibitory effect on the jejunum villi growth, whereas apple and red-wine pomace have stimulating effect on crypt size in piglet colon. Apple and red-wine pomace can reduce the GALT activation via the Peyer's patches in the ileum. In conclusion, the flavanoids rich feeding regimen showed positive effects on villi morphology, GALT activation and can improve pig health.  相似文献   
52.
灌木抗旱机理研究   总被引:9,自引:5,他引:4  
从灌木生长性状、形态结构、细胞质膜透性、光合、渗透调节(可溶性糖、脯氨酸、甜菜碱和无机离子)、ABA和LEA蛋白变化及其与灌木抗旱性的关系方面,综述了灌木抗旱机理研究.  相似文献   
53.
Phenotypic variation in organisms depends on the genotype and the environmental constraints of the habitat that they exploit. Therefore, for marine species inhabiting contrasting aquatic conditions, it is expected to find covariation between the shape and its spatial distribution. We studied the morphology of the head and cephalic sensory canals of the eelpout Austrolycus depressiceps (4.5–22.5 cm TL) across its latitudinal distribution in South Pacific (45°S–55°S). Geometric morphometric analyses show that the shape varied from individuals with larger snout and an extended suborbital canal to individuals with shorter snouts and frontally compressed suborbital canal. There was size variation across the sampled populations, but that size does not have a clear latitudinal gradient. Only 8% of the shape variation relates to this size variation (allometry), represented by a decrease in the relative size of the eye, and a depression of the posterior margin of the head. There were spatial differences in the shape of the head, but these differences were probably caused by allometric effects. Additionally, 2 of the canals of the cephalic lateralis pores and the head shape showed modularity in its development. This study shows that the morphology of marine fish with a shallow distribution varies across distances of hundreds of kilometers (i.e., phenotypic modulation).  相似文献   
54.
Habitats are characterized by different local environmental conditions that influence both behavior and morphology of species, which can result in habitat-dependent phenotypic differences among animals living in heterogeneous environments. We studied 3 alpine populations of Eurasian red squirrels (Sciurus vulgaris), 1 living in a marginal high-elevation habitat at the edge of the species’ altitudinal distribution, and 2 occurring in higher-quality habitats. Here, we investigated whether squirrels living in the marginal area differed in 2 morphological parameters (body size and body mass) and/or in the expression of 4 personality traits estimated with an open field test and a mirror image stimulation test (activity, exploration, activity-exploration, and social tendency). Furthermore, we tested whether within-individual variance of the traits (behavioral plasticity) was higher in the edge habitat. Male squirrels in the edge habitat were smaller and weighed less than in the other study areas, while among females, size–habitat relationships were less marked. These sex-specific patterns were explained by a strong association between body mass and reproductive success in female squirrels. Squirrels in the marginal habitat were more active, explorative, and had a more social personality than in the other habitats. However, in contrast to our predictions, behavioral plasticity was smaller in the marginal habitat, but only for the trait exploration. Our results suggest that animals choose the habitat that best fits their personality, and that habitat-related differences in selective pressures may shape animals’ morphology.  相似文献   
55.
砂轮约束磨粒喷射精密光整加工有效性实验验证   总被引:1,自引:0,他引:1  
通过实验验证了砂轮约束磨粒喷射精密光整加工方法的有效性,利用M7120平面磨床对Q235A进行了喷射加工实验,用TALYSURF5轮廓仪测量了加工后的微观几何参数值,用扫描电镜和金相显微镜观察了表面微观形貌和断面金相组织变化。实验结果表明,该加工方法在表面粗糙度得到减小的同时,能明显去除磨削加工过度塑性变形,减少表面层污染和磨削烧伤,改善表面形状精度,实验结果和理论分析吻合,验证了该工艺方法的正确性。  相似文献   
56.
基于虚拟仪器的农产品"身份证"数字识别系统   总被引:1,自引:0,他引:1  
钱稷  钱东平  周娟 《农机化研究》2007,(12):160-162
介绍了基于虚拟仪器图形化语言LABVIEW开发的农产品"身份证"数字识别系统,采用CCD摄像机对农产品"身份证"编号进行采集,通过PCI-1411彩色图像采集卡将图像传输到计算机并进行图像处理,最后应用美国NI公司的OCR软件包对处理好的编号进行识别.结果表明,该系统抗干扰能力强且精度高.  相似文献   
57.
通过30000km道路行驶试验研究表明,密封滚子链的磨损形式,对销轴和套筒而言是以疲劳磨损为主,伴随有粘着磨损与磨粒磨损;对链板和O形圈而言主要是疲劳磨损,并且O形圈的磨损要比链板的磨损严重得多。销轴和套筒表层磨损后产生了循环硬化特性,有利于提高其铰链副的耐磨性。  相似文献   
58.
秸秆揉切机用刀片磨损的研究   总被引:4,自引:1,他引:4  
对9RZ-60型揉切机用刀片进行了磨损试验,探讨了刀片材料、作业对象、装机位置和刃口形式对刀片磨损的影响,对65Mn、T10和Crl2MoV三种材料的刀片磨损表面形貌进行了微观分析,指出加工羊草时,刀片材料为主要影响因素,加工玉米秸和豆秸时,刃口形式为主要影响因素。刀片加工秸秆的磨损形式是以抛光磨损为主,辅之以硬杂质造成的磨料磨损。  相似文献   
59.
降雨强度和坡度对细沟形态特征的综合影响   总被引:21,自引:0,他引:21  
细沟的形态特征研究可揭示坡面侵蚀发生机理,且细沟形态对坡面径流和侵蚀有重要影响;而现有研究仅用细沟密度和细沟宽深比等指标来表征细沟形态,不能全面准确地反映细沟的形态特征。为此基于模拟降雨试验,研究降雨强度和坡度对黄土坡面细沟侵蚀和细沟形态特征的综合影响。试验处理包括3种黄土高原有代表性的侵蚀性降雨(50、75、100 mm/h)和3个细沟侵蚀发生最常见的坡度(10°、15°、20°)。试验结果表明,坡面侵蚀速率和细沟侵蚀速率均随着降雨强度和坡度的增加呈幂函数增加。试验条件下,细沟倾斜度介于16°~20°之间,随着降雨强度的增加而增大,随着坡度的增加而减小;细沟密度、细沟割裂度和细沟复杂度分别为0.74~1.95 m/m2、0.08~0.17和1.09~1.38,三者皆随降雨强度和坡度的增加而增大;细沟宽深比为1.93~2.35,随着降雨强度和坡度的增加而减小。通过相关分析发现,细沟割裂度是评价细沟侵蚀和细沟形态的最优指标;研究降雨强度对细沟形态的影响时,建议优先选用细沟割裂度、细沟复杂度和细沟倾斜度指标;分析坡度对细沟形态的影响时,除选取细沟割裂度外,建议优先选用细沟密度和细沟宽深比指标。细沟横断面主要呈"V形",随着降雨强度和坡度的增加,径流紊动性增强,细沟横断面变化趋于不规则,说明细沟横断面变化可以反映径流的变化特征,从而揭示细沟侵蚀发生机理。  相似文献   
60.
柑橘溃疡病(Xanthomonas citri subsp. citri,Xcc)是严重阻碍柑橘产业发展的世界性检疫病害,防控困难,选育抗病品种为防治溃疡病的唯一有效办法。枸橼C-05是柑橘属独特的抗溃疡病种质,为抗性机理和抗病育种提供了种质基础。为了进一步评价枸橼C-05的抗性,另外收集了13份枸橼种质,对其进行溃疡病的离体和活体抗性评价。叶片形态学观察表明,14份枸橼种质存在较大的形态学差异。采用离体与活体注射接种不同浓度的柑橘溃疡病菌,根据叶片的感病症状、病斑周围黄色晕圈大小等典型溃疡病症状,综合评价枸橼类种质的抗病性。结果表明:枸橼种质之间对溃疡病的抗性存在极大差异,溃疡病的抗性评价综合病情指数显示枸橼C-05、园香橼、矮果香橼、美国枸橼、普通枸橼和印度大果综合病情指数较小,表现为极抗病或抗病,其他枸橼种质表现不同程度的感病性;枸橼种质的抗病或感病性与其叶片形态特征无关。枸橼C-05和5个抗病枸橼种质对柑橘溃疡病具有针对性的抗性,这对进一步研究抗病机理和抗病育种具有重要意义。  相似文献   
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