基于改进SVM分类器的动作识别方法

利用智能手机加速度传感器信号,提出一种改进的动作识别方法以降低传统动作识别方法的复杂程度,提高识别率。在特征提取时用盲选法,即用PCA(principal component analysis)进行特征值的降维和去除多维间的干扰,而所选特征没有对应的物理意义;并在分类识别中将遗传算法应用到SVM(support vector machine)分类器参数优化中。通过实验表明,该方法能够对日常的走路、站立、跑及上下楼等动作进行准确的识别。     

四种SBIs类杀菌剂对不同发育阶段小麦赤霉病菌的毒力及其作用方式

为明确不同发育阶段小麦赤霉病菌对甾醇生物合成抑制剂类(SBIs)杀菌剂的敏感性差异及杀菌剂的作用方式,对4种SBIs类杀菌剂进行了室内毒力测定及田间药效试验。室内毒力测定结果表明:不同发育阶段小麦赤霉病菌对4种SBIs类药剂的敏感性存在较大差异,其敏感性由高到低依次为菌丝生长阶段和产孢阶段芽管伸长阶段孢子萌发阶段;其中,戊唑醇对菌丝生长、产孢、芽管伸长和孢子萌发阶段的EC50值分别为0.686、0.191、3.532和3.825μg/m L,咪鲜胺分别为0.063、0.305、0.827和36.581μg/m L,苯醚甲环唑分别为0.873、3.659、5.687和79.465μg/m L,烯唑醇分别为1.961、33.658、41.881和54.986μg/m L。显微观察4种SBIs类杀菌剂对小麦赤霉病菌菌丝生长和孢子萌发形态的影响,发现杀菌剂处理后菌丝末端分枝增多,新生菌丝伸长受阻,菌丝体局部膨大,有时可见菌丝及芽管的消解。田间试验结果表明:用量为有效成分100 g/hm2的戊唑醇、200 g/hm2的咪鲜胺和200 g/hm2的苯醚甲环唑对小麦赤霉病的保护效果为77.15%~79.26%,治疗效果为70.64%~72.77%,于发病前后使用均可有效防治该病害。     

Segregation of non‐target‐site resistance to herbicides in multiple‐resistant Alopecurus myosuroides plants

Non‐target‐site resistance (NTSR) comprises a set of mechanisms conferring resistance to multiple modes of action. Investigation of the number of loci involved in NTSR will aid in the understanding of these resistance mechanisms. Therefore, six different multiple herbicide‐resistant Alopecurus myosuroides plants with different herbicide history were crossed in two generations with a susceptible wild type. Seeds from the backcrossing generation were studied for their segregation rate for resistance to five herbicides with four different modes of action (HRAC groups C₂, A, B and K₃). Taking into account that NTSR is a set of quantitative traits, the numbers of loci controlling NTSR were estimated using a normal mixture model fitted by the NLMIXED procedure of SAS. Each herbicide was controlled by a different number of loci comparing the six plants. In most of the cases, chlorotoluron resistance was controlled by one locus, whereas resistance to fenoxaprop‐P‐ethyl needed one or two loci. Resistance to pinoxaden was in all plants conferred by two loci. Cross‐resistance of fenoxaprop‐P‐ethyl and pinoxaden was found in all backcrossings, indicating that at least one of the two loci is responsible for both resistances. Resistance to mesosulfuron + iodosulfuron was conferred by a minimum of two loci. Results indicated that a minimum of five different loci can be involved in a multiple NTSR plant. Furthermore, the plant‐specific accumulation of NTSR loci was demonstrated. Such behaviour should be taken into account when evaluating the development and further spread of herbicide resistance.     

Classification of herbicides according to chemical family for weed resistance management strategies – an update

There are inaccuracies in the chemical families of the WSSA and HRAC herbicide classification systems which could limit their practical use in herbicide‐based weed management strategies. In essence, these inaccuracies could be divided into four parts: (i) the nomenclature of many of the chemical families is not correct, (ii) distinct active ingredients are grouped in same chemical families, (iii) many chemical families have been repeated in at least two modes of action/herbicide groups, and (iv) many active ingredients have not been assigned to chemical family, herbicide group or mode of action. The aim of this study was to revise the current classifications and to propose corrections for the current ones. Detailed investigations on chemical structure of the active ingredients of the registered herbicides showed that some moieties have the same mechanisms of action. According to this study, these moieties have been assigned to the names of chemical families and active ingredients are then classified within the chemical families accordingly. This study has 119 chemical families, compared with 145 in the WSSA system and 58 in the HRAC system. A major priority of this study is the number of active ingredients covered; we included 410 active ingredients with known mechanisms of action and herbicide groups, more than 100 active ingredients more than the current classification systems. Overall, this study provides better opportunities for the management of resistance to herbicides through the application of improved pure and applied knowledge.     

丹翘灌注液抗炎镇痛作用的研究

研究丹翘灌注液的抗炎镇痛作用。采用二甲苯致小鼠耳廓肿胀、棉球致小鼠肉芽肿、小鼠醋酸扭体反应、小鼠福尔马林致痛模型观察丹翘灌注液的抗炎和镇痛作用。40、20、10 g/kg的丹翘灌注液能不同程度的抑制二甲苯引起的小鼠耳廓肿胀、棉球引起的肉芽肿增生;不同程度的减少醋酸引起的小鼠扭体次数和福尔马林引起的舔足时间。结果表明,丹翘灌注液具有抗炎、镇痛的作用。     

白酒草属3种外来植物对黄瓜靶斑病菌的抑菌作用

为了解白酒草属3种外来植物的抑菌作用,并探讨其可能的亲缘关系,采用生长速率法测定白酒草属3种外来植物小蓬草、香丝草、苏门白酒草丙酮浸提液对黄瓜靶斑病菌菌丝生长的影响。结果表明：小蓬草、香丝草、苏门白酒草浸提液对黄瓜靶斑病菌菌丝生长均有抑制作用,且抑制率随浸提液质量浓度的提高而增大,随培养时间的延长而降低。相同浓度下,对菌丝生长的抑制作用最强的是小蓬草浸提液,苏门白酒草与香丝草浸提液对菌丝生长的抑制率较低。3种外来植物中,苏门白酒草与香丝草抑菌率较接近,化学成分、亲缘关系可能较近。     

Direct-fed microbes: A tool for improving the utilization of low quality roughages in ruminants

For many years, ruminant nutritionists and microbiologists have been interested in manipulating the microbial ecosystem of the rumen to improve production efficiency of different ruminant species. Removal and restriction of antibiotics subtherapeutic uses from ruminant diets has amplified interest in improving nutrient utilization and animal performance and search for more safe alternatives. Some bacterial and fungal microorganisms as a direct-fed microbial(DFM) can be the most suitable solutions. Microorganisms that are commonly used in DFM for ruminants may be classified mainly as lactic acid producing bacteria(LAB), lactic acid utilizing bacteria(LUB), or other microorganism's species like Lactobacillus, Bifidobacterium, Enterococcus, Streptococcus, Bacillus, Propionibacterium, Megasphaera elsdenii and Prevotellabryantii, in addition to some fungal species of yeast such as Saccharomyces and Aspergillus. A definitive mode of action for bacterial or fungal DFM has not been established; although a variety of mechanisms have been suggested. Bacterial DFM potentially moderate rumen conditions, and improve weight gain and feed efficiency. Fungal DFM may reduce harmful oxygen from the rumen, prevent excess lactate production, increase feed digestibility, and alter rumen fermentation patterns. DFM may also compete with and inhibit the growth of pathogens, immune system modulation, and modulate microbial balance in the gastrointestinal tract. Improved dry matter intake, milk yield, fat corrected milk yield and milk fat content were obtained with DFM administration. However, the response to DFM is not constant; depending on dosages, feeding times and frequencies, and strains of DFM. Nonetheless, recent studies have supported the positive effects of DFM on ruminant performance.     

利福昔明的药理作用及其在奶牛疾病防治中应用的研究进展

利福昔明是一种治疗奶牛疾病的新药,抗菌谱广,抗菌活性强,抗菌机制独特,无致突变、致畸、致癌及生殖毒性等,适合作为局部用药。作者综述了利福昔明的研究现状,并对其理化性质、作用机制、药动学、药理毒理学性质及在临床疾病防治中的应用进行了描述,为利福昔明在动物临床疾病防治应用方面提供理论依据,以便兽医工作者全面了解该药,进而指导其临床应用。     

西瓜ClPDF2.1蛋白的原核表达及其对香蕉枯萎病菌的抑制活性测定

尖孢镰刀菌古巴专化型侵染香蕉引起的香蕉枯萎病严重危害中国香蕉产业。植物防卫素是一类小的富含半胱氨酸的抗真菌蛋白。本研究旨在了解西瓜（Citrullus lanatus）防卫素蛋白ClPDF2.1对香蕉枯萎病菌的抑制活性。提取西瓜RNA后反转录为cDNA,以西瓜cDNA为模板,克隆ClPDF2.1基因,将测序正确的ClPDF2.1连接到载体pGEX-6P-1,随后转化Trans BL21(DE3)pLysS,IPTG 诱导GST-ClPDF2.1融合蛋白表达16 h后,经SDS-PAGE电泳及Western blot鉴定GST-ClPDF2.1融合蛋白的表达,进行GST-ClPDF2.1融合蛋白体外抑制香蕉枯萎病菌生长的功能初探。本研究为进一步培育转基因香蕉抗病品种奠定基础。     

灵芝木质素降解酶研究及其潜在应用进展

灵芝不仅具有很好的药理活性,而且具有高效降解木质素的潜在特性。为进一步了解灵芝木质素降解酶作用机制及其表达调控,促进灵芝木质素降解酶研究和相关产业发展,分别对木质素降解酶组成和生物降解机制、灵芝木质素降解酶表达调控以及灵芝木质素降解酶潜在应用前景进行评述,并针对灵芝降解木质纤维素过程研究中存在的问题提出相关研究建议。