Modeling the relationship between the main emulsion components and stability, viscosity, fluid behavior, zeta-potential, and electrophoretic mobility of orange beverage emulsion using response surface methodology

The possible relationships between the main emulsion components (namely, Arabic gum, xanthan gum, and orange oil) and the physicochemical properties of orange beverage emulsion were evaluated by using response surface methodology. The physicochemical emulsion property variables considered as response variables were emulsion stability, viscosity, fluid behavior, zeta-potential, and electrophoretic mobility. The independent variables had the most and least significant ( p < 0.05) effect on viscosity and zeta-potential, respectively. The quadratic effect of orange oil and Arabic gum, the interaction effect of Arabic gum and xanthan gum, and the main effect of Arabic gum were the most significant ( p < 0.05) effects on turbidity loss rate, viscosity, viscosity ratio, and mobility, respectively. The main effect of Arabic gum was found to be significant ( p < 0.05) in all response variables except for turbidity loss rate. The nonlinear regression equations were significantly ( p < 0.05) fitted for all response variables with high R (2) values (>0.86), which had no indication of lack of fit. The results indicated that a combined level of 10.78% (w/w) Arabic gum, 0.56% (w/w) xanthan gum, and 15.27% (w/w) orange oil was predicted to provide the overall optimum region in terms of physicochemical properties studied. No significant ( p > 0.05) difference between the experimental and the predicted values confirmed the adequacy of response surface equations.     

干旱区受损植被生态恢复需水量——以新疆哈巴河县平原区为例

[目的]分析干旱区受损植被恢复过程中生态需水量,为生态恢复不同阶段所需水资源量及水资源优化配置提供科学依据。[方法]基于1990,2000,2010,2015,2020年Landsat系列影像,采用遥感技术,结合改进的彭曼公式法,对新疆哈巴河县平原区植被耗水量时空演变特征及生态恢复需水量进行了定量研究。[结果](1)1990—2020年天然植被平均耗水量为7.55×10⁸ m³,以3.60×10⁷ m³/5 a的速率减小,与之对应的是天然植被面积以17.36 km²/a的速率减小,植被覆盖度从高植被覆盖度向中植被覆盖度转化,生态受损严重。(2)区域内植被耗水量时空分布均存在较大差异：空间上高值主要分布于哈巴河流域,别列则克河流域植被耗水量整体偏低;时间上年际变化以2000年植被耗水量为最高,年内植被耗水量则主要集中在生长中期。(3)绿洲区生态恢复需水量如下：维持现状(2020年)生态需水量为4.62×10⁸ m³,恢复到1990—20...     

Rhodococcus equi in the soil environment of horses in Inner Mongolia, China

Little is known about the distribution of Rhodococcus equi in the soil environment of native horses in China. One hundred and eight soil samples were collected from native-horse farms in the Hulun Beier grasslands of eastern Mongolia, the Xilin Goler grasslands of southern Mongolia, and Tongliao City in Inner Mongolia, China. The isolation rates of R. equi from soil samples from the Hulun Beier and Xilin Goler grasslands ranged from 25.9% to 30.0%. In contrast, isolation rates from soil samples from Tongliao City were as high as 82.3% and the mean number of R. equi in soil samples from Tongliao City was 10 times more than those of samples from the grasslands. The 488 isolates were examined using PCR for the presence of genes that encode virulence-associated 15-17 kDa antigen protein (VapA) and the 20 kDa antigen protein (VapB). All isolates were negative for virulence-associated proteins. Plasmid profiles of these avirulent isolates showed that cryptic plasmids of various sizes were present with an incidence of 13.3% to 21.5%. The results of the present study contrast with those of our recent study (J. Vet. Med. Sci. 67:611-613, 2005), in which we reported that R. equi was absent from Mongolian horses in Ulaanbaatar, Mongolia. It is suggested that the difference between the results of these two studies is due to the mobile pasturing system in Mongolia and nonmobile pasturing system in Inner Mongolia.     

Anisotropy and corotation of galactic cosmic rays

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.     

两种中药方剂对猪流感的防治效果比较试验

本文对自行研制的中草药方剂疏风清热散与银翘散对猪流感的防治效果进行对比试验.在猪流感抗体阴性试验场临床健康猪群中随机选取60头体重(约30 kg)和体况基本一致的猪,随机分成3个组,每组20头,第1组和第2组分别为疏风清热散和银翘散试验组,第3组为对照组(不给药).预防效果试验给药1/5荆/(d·头),粉碎均匀分2次拌入料中喂服;治疗效果试验给药1剂/(d·头),煎后分2次喂服,给药时间均为5 d.结果显示,两种方荆对预防和治疗猪流感均有较好效果.但疏风清热散的防治作用优于银翘散.     

基于LMPSO-SVM的高光谱水稻稻瘟病害分级检测

为减少水稻产量损失,迫切需要建立快速、准确的水稻叶瘟监测和鉴别方法。本文以东北水稻为研究对象,以小区试验为基础,使用高光谱图像仪获取受稻瘟病菌侵染后不同发病程度的水稻叶片高光谱图像并提取光谱数据。首先,通过SG平滑方法对光谱数据进行预处理,然后运用主成分分析(PCA)、Pearson相关系数分析法(PCCs)、PLS-VIP方法对光谱数据进行降维,并提出了一种基于Logistic混沌映射PSO寻优的SVM分级检测模型(LMPSO-SVM)。为了验证提出方法的有效性,以不同降维方法提取的特征变量为输入,分别建立基于人工神经网络(ANN)、支持向量机(SVM)和PSO-SVM的分级模型并进行对比分析。仿真结果表明,各模型对4级病害的识别效果最好,综合5种级别病害,SVM和ANN分级模型的预测准确率波动相对较大,对于病害预测效果不太理想;而在不同特征选择下建立的LMPSO-SVM分级模型对各级病害预测准确率均较高,准确率波动较小,其中基于PCA提取特征变量和全波段作为输入的模型平均准确率非常相近,分别为96.49%和96.12%,PCA提取的输入变量仅为5个,大大简化了模型复杂性,降低了训练...     

湖南省长沙市宠物医院犬弓形虫病血清学调查

为了解湖南省长沙市宠物犬弓形虫感染状况,2017—2018年对长沙市宠物监测点的犬只抽样,采用间接酶联免疫方法进行弓形虫抗体检测。2017年共抽检血清707份,发现抗体阳性率为9.34%;2018年抽检血清711份,发现抗体阳性率为8.02%,较2017年稍微下降。从不同地区比较,天心区弓形虫感染率较高,均在13%以上;芙蓉区、岳麓区阳性率出现下降趋势,其中芙蓉区下降最快,从9.88%下降到4.79%,岳麓区从10.20%下降到6.98%;其他两区阳性率维持在7%～9%之间,相对平衡。对不同犬种、性别、年龄及季节进行比较分析发现,不同品种犬的弓形虫感染情况有差异,萨摩、中华田园、雪纳瑞、博美、柯基等犬种的阳性率相对偏高,在10%以上;犬弓形虫感染与性别关联性不大,差异不显著(P=0.086, 0.05);1岁以上犬的阳性率明显高于1岁以下犬,差异显著(P=0.012,0.05);不同季节犬只的弓形虫抗体阳性率差异显著(P=0,0.05)。调查表明:长沙市城区存在一定的犬弓形虫流行,整体呈下降趋势;犬弓形虫感染与年龄、季节相关,年龄越大阳性率越高,冬季更易感染。建议加强犬类管理,向饲养者普及相关饲养及弓形虫病预防知识,尤其是弓形虫感染严重地区;定期做好弓形虫检查和驱虫工作,重点关注感染率较高的犬种和1岁以上犬,尤其是冬季。本研究初步摸清了长沙市城区宠物犬弓形虫的感染程度及分布特点,为今后弓形虫病防控提供了数据支撑。     

粳稻杂种劣势的遗传及表型特性分析

杂种优势是自然界的一种普遍现象,但在杂交水稻育种实践中也时常发现杂种劣势现象,为了更好地阐明杂交育种理论和揭示品种本质有必要对杂种劣势的遗传机理进行更深层次的研究。本研究旨在通过两个韩国粳稻品种(Aranghyangchalbyeo和Sanghaehyangheolua)及其正反交后代(F1,F2)特性的比较,解析水稻杂种劣势的表型、类别及其遗传模式。形态学分析表明,正反交F1植株的劣势表现均明显、稳定且不受环境影响,主要农艺性状的中亲劣势值均为负值,其中F1的株高、分蘖数和结实率与亲本相比显著降低(P<0.01);F1劣势表现从发芽后第5d开始,地下部的劣势表现比地上部更为明显。细胞组织结构观察表明,分蘖盛期F1劣势植株叶片发育正常,而其根部气腔发育较亲本迟缓,从而阻碍了地上部与地下部的通气情况,因此也影响了整个植株的正常生长。遗传学分析发现,该劣势组合成熟期F2群体中正常与劣势植株呈现7:9的分离,结合分蘖盛期该F2群体株高的分离模式,推断该杂种劣势的表型是由两个互补的显性基因控制。该研究结果为揭示杂种劣势的多样性及分子遗传机制提供了新思路。     

分子标记辅助改良培矮64S稻瘟病抗性

为提高我国大面积应用的两系光温敏不育系培矮64S的稻瘟抗性,本研究通过杂交转育与分子标记选择相结合的途径,利用RM3330与RM262为标记,将Pi25与Pi-d(t)基因成功聚合于培矮64S中,经抗性、不育性、综合农艺性状评价,获得了5个基因型纯合且农艺性状稳定的F8代抗性改良候选不育系。抗性鉴定结果显示,抗性改良候选不育系及其抗性组合的叶瘟病情指数平均降幅为18.78%和23.24%,穗颈瘟病情指数平均降幅为18.58%和58.45%,抗性提高幅度极显著。育性观测结果表明抗性改良候选不育系不育度都在99.5%以上,柱头外露降低5.64%,包颈粒率降低8.55%。经济性状调查结果显示不育系除穗粒数下降、有效穗增加外,其余经济性状变化不明显;试配的杂交组合平均理论产量和实际产量比对照提高16.22%和6.89%,增产极显著。这些结果表明,通过Pi25与Pi-d(t)基因的导入显著提高了培矮64S稻瘟病抗性,获得了实用的光温敏不育系新材料。