Effects of dietary energy level on lipid metabolism‐related gene expression in subcutaneous adipose tissue of Yellow breed × Simmental cattle

This study was conducted to estimate the effect of dietary energy level on lipid metabolism‐related gene expression of subcutaneous adipose tissue in Yellow breed × Simmental cattle. The experiment was conducted for 60 days. The results showed that final weight, average daily gain, average backfat thickness, (testicles + kidney + pelvic) fat percentage and subcutaneous fat percentage in the high and medium energy groups were significantly higher than in the low‐energy group but that the feed conversion ratio was significantly lower. The glucose, triglycerides, cholesterol, high‐density lipoprotein and low‐density lipoprotein in the high‐energy group were significantly higher than in the low‐energy group. With dietary energy increasing the activities of lipoprotein lipase (LPL), fatty acid synthase (FAS) and acetyl‐CoA carboxylase (ACC) significantly increased, whereas hormone‐sensitive lipase (HSL) and carnitine palmitoyltransferase‐1 (CPT‐1) significantly diminished. Peroxisome proliferator‐activated receptor γ (PPARγ), LPL, FAS, sterol regulatory element binding protein 1 (SREBP‐1), ACC, stearoyl‐CoA desaturase (SCD) and adipocyte‐fatty acid binding proteins (A‐FABP) gene expression were significantly increased by dietary energy increasing, and HSL and CPT‐1 gene expression were significantly decreased. These results indicated that with dietary energy increasing, the subcutaneous fat accumulation mainly increased due to adipose tissue lipogenic gene expression and decreased lipolytic gene expression.     

关岭牛MyoD Ⅰ基因在不同组织和时期中的表达分析

为研究MyoDⅠ基因在关岭牛不同组织表达量的差异及在肌肉发育过程中的表达情况,试验采用实时荧光定量PCR技术对关岭牛背最长肌、大腿肌、心脏、肝脏、脂肪、小肠6个组织的MyoDⅠ基因相对表达量进行检测。同时分析关岭牛胎儿、18月龄、30月龄时期背最长肌组织中MyoDⅠ基因的表达规律。结果显示,MyoDⅠ基因在背最长肌中表达量最高,在出生后的关岭牛肌肉组织中也具有较高的表达量,且随着出生时间的推移呈上升趋势。推测可能由于背最长肌是肌肉富集地方,因此基因表达量较高,随着年龄增大,肌肉丰满度增加,基因表达量也随着增加。     

县级森林资源信息管理系统设计

运用建模工具软件、采用可视化建模的方法及标准的建模语言,比较系统地介绍了通用且符合“数字林业标准与规范”的县级森林资源信息管理系统的设计思想、主要内容及建立方法。内容包括：(1)系统开发思想与方法;(2)系统设计目标与要求;(3)系统分析及设计;(4)县级森林资源管理系统开发方法等。     

当前平原林业经营形式与农林业发展的关系

当前,邯郸平原的林业经营形式主要有集体经营、联产承包经营和单户经营等3种;这些经营形式,是与农村经济体制改革和当前生产力水平相适应的,对林业生产的发展有促进作用.本文还提出了影响林业发展的几个问题,需要加以解决。     

噪声环境下木材纹理分类的研究

为了实现木材分类识别的自动化,应用灰度共生矩阵建立了木材纹理的参数体系,并进行了分类研究。首先在无噪声的环境下提取了木材的共生矩阵纹理原始特征参数,并对其进行特征选择,进而建立了木材纹理参数体系。对该参数体系进行噪声适应性测试的实验结果表明,无噪声情况下样本识别率为87.50%;0.2%￣1.0%椒盐噪声环境下样本识别率范围为87.00%￣88.00%。表明该参数体系具有良好的抗击噪声能力和一定的工程实用价值。     

农户家庭经营问题研究——对邢台县浆水镇农户抽样调查材料的分析

本文应用数理统计方法对邢台县浆水镇9村265户样本资料进行了系统分析。指出农户家庭经营是我国农村普遍存在的基本经营形式。这一新生事物完全适应现阶段农村生产力发展水平,其收入已成为农民收入的主要来源。近年来,农民收入虽有大幅度提高,但水平仍然很低,农户间收入差距也在不断扩大,山区农村经济仍在一个低水平上运行。本文还对影响农民收入水平的相关因素和农户收支结构进行了分析,并有针对性地提出改善家庭经营管理的建议。最后,对加强农户家庭经营方面的研究与领导也提出具体意见。     

马尾松不同选择水平的研究

在福建省马尾松优良种源区内选择１０个有代表性的县（市），每个县（市）各选１片林分，按优树。优势木和平均木３种不同选择水平进行选择，采收各自的自由授粉种子进行子代测定试验，９年生树高生长统计分析结果表明：林分间和不同林分不同选择水平的差异极为显著；同一林分不同选择水平的差异不显著。马尾松遗传改良要特别注重种源和林分的选择，在此基础上进行个体选择。     

基于计算机断层扫描技术的木材密度检测研究

使用计算机断层扫描技术进行原木无损检测,通过对原木树种断层 CT 值的统计,对 CT 设备在检测过程中的窗宽与窗位进行了设定,同时拟合出了木材 CT 值一密度值的线性方程,为原木缺陷的无损检测及木材密度的测定提供一种新方法。     

Numerical experiments of watershed-scale soil water movement and bedrock infiltration using a physical three-dimensional simulation model

Numerical experiments of soil water movement and bedrock infiltration based on a simplified simulation method were conducted to analyze watershed-scale rainfall-runoff processes. To verify the model accuracy, it was applied to a Minamitani watershed (0.45 ha). The simulation was performed with 2.5-m space grids horizontally and five cells vertically. Results of long-term calculation of this model proved that this simulation model is robust and demonstrated good computational water mass conservation. Calculation results showed the best agreement with observed hydrographs and the number of groundwater levels simultaneously when laboratory-tested soil hydraulic characteristics for topsoil were used and infiltration into bedrock was included in numerical calculations. Numerical experiments show that bedrock infiltration generated a stable base flow and suppressed the secondary discharge peak. The reproducibility achieved by observed soil hydraulic characteristics with the assumption of bedrock flow demonstrates the effectiveness of the simulation model used in this article for analyses of watershed-scale soil water movements.     

Linking wolves to willows via risk-sensitive foraging by ungulates in the northern Yellowstone ecosystem

After an absence of approximately 70 years, gray wolves (Canis lupus) were re-introduced into Yellowstone National Park in the mid-1990s. We studied the potential influence of wolf/ungulate interactions upon willow (Salix spp.) growth in the valleys of the Gallatin and Lamar Rivers, as well as Slough and Soda Butte Creeks, in the northern Yellowstone ecosystem. When we compared willow heights from photographs taken prior to 1998 (willows <2 m tall) with those taken in 2004, we found an increase in willow height for 22 of 42 sites within the study area. Based on comparisons of the chronosequence photos, since wolf introduction none of the 16 upland riparian sites showed an increase in willow height, while 22 of 26 of the valley-bottom riparian sites had willow height increases. In 2004, willow height exhibited a strong inverse relationship with the percentage of browsed stems (r = −0.81, p < 0.01, n = 42). Results of regressions for valley-bottom sites indicated that view distance, impediment distance, and the number of bison (Bison bison) flops were inversely related to willow height (p ≤ 0.02). Increased willow heights were not significantly (p = 0.18) related to patterns of moisture availability. Willow height increases documented in this study appear to have been at least partially due to behaviorally mediated trophic cascades involving wolves and ungulates, via a mechanism of predation risk. While willow release (i.e., increased height growth) within the study area is in a very early stage, results suggest potentially important indirect effects of a top carnivore in a terrestrial food chain that may aid in the restoration of riparian species and the preservation of biodiversity.