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91.
Gaëlle Boudry M. Kristina Hamilton Maciej Chichlowski Saumya Wickramasinghe Daniela Barile Karen M. Kalanetra David A. Mills Helen E. Raybould 《Journal of dairy science》2017,100(4):2471-2481
Obesity is characterized by altered gut homeostasis, including dysbiosis and increased gut permeability closely linked to the development of metabolic disorders. Milk oligosaccharides are complex sugars that selectively enhance the growth of specific beneficial bacteria in the gastrointestinal tract and could be used as prebiotics. The aim of the study was to demonstrate the effects of bovine milk oligosaccharides (BMO) and Bifidobacterium longum ssp. infantis (B. infantis) on restoring diet-induced obesity intestinal microbiota and barrier function defects in mice. Male C57/BL6 mice were fed a Western diet (WD, 40% fat/kcal) or normal chow (C, 14% fat/kcal) for 7 wk. During the final 2 wk of the study, the diet of a subgroup of WD-fed mice was supplemented with BMO (7% wt/wt). Weekly gavage of B. infantis was performed in all mice starting at wk 3, yet B. infantis could not be detected in any luminal contents when mice were killed. Supplementation of the WD with BMO normalized the cecal and colonic microbiota with increased abundance of Lactobacillus compared with both WD and C mice and restoration of Allobaculum and Ruminococcus levels to that of C mice. The BMO supplementation reduced WD-induced increase in paracellular and transcellular flux in the large intestine as well as mRNA levels of the inflammatory marker tumor necrosis factor α. In conclusion, BMO are promising prebiotics to modulate gut microbiota and intestinal barrier function for enhanced health. 相似文献
92.
A multiplex polymerase chain reaction was developed to simultaneously identify Listeria monocytogenes and species of the genus Listeria. Two sets of primers were used, with the first amplifying a 938-bp region of the 16S rRNA gene that is highly conserved in all Listeria species and the second amplifying a 174-bp region of the listeriolysin (hlyA) gene of L. monocytogenes. Thus, isolates of Listeria spp. yield a single 938-bp product, whereas L. monocytogenes isolates yield both the 938-bp product and a 174-bp product. The specificity of the assay was verified with all six Listeria species and 11 serotypes of L. monocytogenes, as well as nonrelated bacteria. The multiplex PCR assay was used to determine the incidence of Listeria spp., especially L. monocytogenes, in mechanically separated turkey samples (n = 150 samples). L. monocytogenes strains were selected by using the University of Vermont two-step enrichment protocol and plating to selective Palcam agar. The multiplex PCR assay was used for verification of presumptive Listeria colonies. Approximately 38% of mechanically separated turkey samples (57 of 150) yielded L. monocytogenes; an additional 18% of these samples (27 of 150) harbored other Listeria spp. Fifty-one percent (29 of 57) of the L. monocytogenes isolates were of serogroup 1, 44% (25 of 57) were of serogroup 4, and 2% (1 of 57) were assigned to serogroups other than 1 and 4. 相似文献
93.
On many types of raw or minimally processed foods, the bacterial microbiota is often composed of mixed species. The activities of one bacterial species may influence the growth and activities of others that are present. The objective of this project was to evaluate the microbial composition of fresh and minimally processed vegetables to determine if naturally occurring bacteria on produce are competitive with or antagonistic to potentially encountered pathogens. Naturally occurring bacteria were obtained from ready-to-eat salad vegetables on four occasions to allow for seasonal variation. Minimally processed vegetables were sampled at various stages in their processing from raw vegetables to packaged products. Some portions were analyzed microbiologically within 24 h, while other portions were stored refrigerated and analyzed after 72 h. Microbiological analysis was conducted for bacterial enumeration and to obtain isolates. An agar spot method was used to screen isolates for antimicrobial activity against Staphylococcus aureus ATCC 27664, Escherichia coli O157:H7 E009, Listeria monocytogenes LCDC 81-861, and Salmonella Montevideo. Of the 1,180 isolates screened for inhibitory activity, 37 (3.22%) were found to have various degrees of inhibitory activity against at least one test pathogen. Many isolates showed inhibitory activity against all four pathogens. The isolates with the most extensive inhibition were removed from finished lettuce piece shreds. Of the 37 inhibitory isolates, 34 (91.9%) were gram negative. All isolates with inhibitory activity are able to multiply at both 4 and 10 degrees C. 相似文献
94.
Synthesizing the movements of a responsive virtual character in the event of unexpected perturbations has proven a difficult challenge. To solve this problem, we devise a fully automatic method that learns a nonlinear probabilistic model of dynamic responses from very few perturbed walking sequences. This model is able to synthesize responses and recovery motions under new perturbations different from those in the training examples. When perturbations occur, we propose a physics‐based method that initiates motion transitions to the most probable response example based on the dynamic states of the character. Our algorithm can be applied to any motion sequences without the need for preprocessing such as segmentation or alignment. The results show that three perturbed motion clips can sufficiently generate a variety of realistic responses, and 14 clips can create a responsive virtual character that reacts realistically to external forces in different directions applied on different body parts at different moments in time. 相似文献
95.
Kavitha?TupellyEmail author Vladik?Kreinovich Karen?Villaverde 《Reliable Computing》2005,11(4):291-312
In many problems in science and engineering ranging from astrophysics to geosciences to financial analysis, we know that a physical quantity y depends on the physical quantity x, i.e., y = f(x) for some function f(x), and we want to check whether this dependence is monotonic. Specifically, finitely many measurements of xi and y = f(x) have been made, and we want to check whether the results of these measurements are consistent with the monotonicity of f(x). An efficient parallelizable algorithm is known for solving this problem when the values xi are known precisely, while the values yi are known with interval uncertainty. In this paper, we extend this algorithm to a more general (and more realistic) situation when both xi and yi are known with interval uncertainty. 相似文献
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97.
对皖南地区的早期矿冶遗址进行综合考察研究,发现存在着配制锡青铜、砷青铜、锑青铜的3种合金技术。青铜冶炼流程为两步法,所用铜料、砷料、锑料应来自当地,锡料推测来自长江中游的赣北且主要以锡砂形式添加。研究还发现,以皖南为代表的长江下游是中国早期又一处重要的砷青铜冶金区,其生产流行的资源背景应与该地区缺乏锡矿有关。研究进一步预示长江流域存在着相当规模且独具特色的早期青铜冶金业,而与黄河流域的中原地区有明显区别。 相似文献
98.
物联网环境下web数据库网络承载着不同的网络载体和网络信道,web数据库通过云储存的形式来实现资源共享,云储存产生的异常数据会给网络信息web数据库空间带来一种危机感和存储数据容量空间的不足,所以对物联网环境下web数据库异常数据的检测要求更精准。传统的异常数据检测方法采用简化梯度方法进行web数据库异常数据检测,对含有干扰频率成份的web异常数据不能准确的去除,检测性能低。为此,提出一种基于时空关联的分布式的web数据库异常数据检测方法,通过与集中式算法的精度和消耗量进行对比,仿真实验表明,所提方法进行异常数据检测,减少了web数据的能量消耗,信号幅值大于干扰噪声数据幅值,具有较好的抗干扰性能。 相似文献
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