Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》
Abstract： Various resting-state fMRI (R-fMRI) measures have been developed to characterize intrinsic brain activity. While each of these measures has gained a growing presence in the literature, questions remain regarding the common and unique aspects these indices capture. The present work provided a comprehensive examination of inter-individual variation and intra-individual temporal variation for commonly used measures, including fractional amplitude of low frequency fluctuations, regional homogeneity, voxel-mirrored homotopic connectivity, network centrality and global signal correlation. Regardless of whether examining intra-individual or inter-individual variation, we found that these definitionally distinct R-fMRI indices tend to exhibit a relatively high degree of covariation. When taken as a measure of intrinsic brain function, inter-individual differences in concordance for R-fMRI indices appeared to be stable, and negatively related to age (i.e., functional concordance among indices decreases with age). To understand the functional significance of concordance, we noted that higher concordance was generally associated with higher strengths of R-fMRI indices, regardless of whether looking through the lens of inter-individual (i.e., high vs. low concordance participants) or intra-individual (i.e., high vs. low concordance states identified via temporal dynamic analyses) differences. Finally, temporal dynamics analyses also revealed that high concordance states are characterized by increased within- and between-network functional connectivity, suggesting more general variations in network integration and segregation. The current study draws attention to questions regarding how to select an R-fMRI index for usage in a given study, as well as how to compare findings across studies that examine inter-individual or group differences using different indices. Additionally, our work suggests global neural signals exist in the brain, and their spontaneous variations over time result in fluctuations in the connectedness of brain regions.
Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究不同类型饲粮和添加剂对肉仔鸡生长性能、肠道结构和功能的影响。试验采用4×3两因子完全随机设计，4种饲粮分别为抗生素饲粮、无抗生素饲粮、低蛋白质饲粮和大麦饲粮，3种添加剂分别为酵母培养物（XPC）、谷氨酰胺（Gln）和大豆异黄酮（ISF）。试验选用1日龄爱拔益加肉仔鸡792只，随机分为12组，每组6个重复，每个重复11只鸡。试验期42 d。结果表明：1）不同类型饲粮分别添加XPC、Gln和ISF对42日龄肉仔鸡平均日增重（ADG）、平均日采食量（ADFI）、料重比（F/G）及体重（BW）的影响无显著差异（P>0.05)；但对饲粮类型而言，与其他3种饲粮相比，低蛋白质饲粮使肉仔鸡的BW、ADG和ADFI显著降低（P＜0.05），F/G显著提高（P＜0.05）；抗生素饲粮显著降低肉仔鸡的F/G（P＜0.05）。饲粮类型与添加剂对肉仔鸡生长性能无显著的互作效应（P＞0.05）。2）与添加Gln相比，抗生素饲粮中添加ISF显著改善19日龄肉仔鸡回肠形态（P＜0.05）；低蛋白质饲粮中添加XPC与添加其他2种添加剂相比对肉仔鸡回肠形态有显著改善作用（P＜0.05）；与添加XPC相比，大麦饲粮中添加ISF显著改善19日龄肉仔鸡回肠形态（P＜0.05）。除35日龄肉仔鸡回肠隐窝深度外，饲粮类型与添加剂对回肠形态存在显著的互作效应（P＜0.05）。3）大麦饲粮中添加XPC比添加Gln和ISF显著提高35日龄肉仔鸡回肠干扰素–γ水平（P＜0.05）；与添加ISF相比，抗生素饲粮中添加XPC可显著提高19日龄肉仔鸡回肠白细胞介素–10（IL-10）和免疫球蛋白A（IgA）水平（P＜0.05），添加Gln可显著提高35日龄肉仔鸡回肠IgA水平（P＜0.05）；低蛋白质饲粮中添加XPC比添加其他2种添加剂显著提高19日龄肉仔鸡回肠IgA水平（P＜0.05）；无抗生素饲粮中添加ISF比添加XPC显著提高35日龄肉仔鸡回肠IL-10和IgA水平（P＜0.05）；而大麦饲粮中添加ISF比添加XPC显著降低35日龄肉仔鸡回肠IL-10水平（P＜0.05）。对于回肠IL-10和IgA水平，饲粮类型与添加剂之间存在显著互作效应（P＜0.05）。4）抗生素饲粮中添加XPC比添加其他2种添加剂显著降低19日龄肉仔鸡粪便中氮和磷残留率（P＜0.05）；无抗生素饲粮中添加XPC比添加其他2种添加剂显著提高19日龄肉仔鸡粪便中氮和磷残留率以及35日龄肉仔鸡粪便中磷残留率（P＜0.05）；低蛋白质饲粮中添加XPC比添加Gln显著降低19日龄肉仔鸡粪便中氮残留率（P＜0.05）；大麦饲粮中添加Gln比添加其他2种添加剂显著降低19日龄肉仔鸡粪便中氮和磷残留率（P＜0.05）。对氮、磷残留率而言，饲粮类型与添加剂之间存在显著互作效应（P＜0.05）。由此可见，4种类型饲粮中添加3种添加剂对1~42日龄肉仔鸡生长性能无显著影响；能氮比固定的低蛋白质饲粮降低了肉仔鸡的生长性能；低蛋白质饲粮中添加XPC可改善回肠形态结构；在不同类型饲粮中添加不同的添加剂具有改善肉仔鸡回肠免疫状态及降低粪便中氮磷残留率的趋势。
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