两色绿刺蛾幼虫空间分布型

应用聚集度指标法、回归分析法、零频率方法对两色绿刺蛾幼虫在毛竹林间的分布型进行测定。结果表明,两色绿刺蛾幼虫在竹林中呈聚集分布,分布的基本成分为个体群。用零频率方法分析得,两色绿刺蛾幼虫种群类型为聚集度零频率制约型,并确定了林间调查的理论抽样数和简单序贯抽样分析表。     

棉红铃虫二代幼虫空间格局参数特征及应用

近年来对棉红铃虫1～3代幼虫在棉田的空间分布型的研究,其结果均属聚集分布,幼虫结构是以疏松个体群形式呈聚集,而个体群内的幼虫为随机。本文进一步利用二代羽化孔内幼虫空间格局参数m~*、k、α、β值,分析了幼虫在棉田聚集的原因,探讨了幼虫平均密度与k值的关系,估计了个体群的大小和平均密度的关系。依关系,由无虫株频率(P_0)来估计幼虫密度,采用零频率估计幼虫密度和以概率保证的理论抽样相结合的方法,实现了简易、有效的抽样。     

草地贪夜蛾幼虫在苗期玉米田的空间分布格局及其抽样技术

草地贪夜蛾Spodoptera frugiperda(Smith)是2019年1月新入侵我国的重要害虫,研究并明确空间格局对确定该虫田间抽样技术、调查虫情具有指导意义。本研究调查获得了玉米苗期喇叭口初期、大喇叭口期草地贪夜蛾幼虫空间分布数据,应用多个聚集指标、Iwao m~*-m模型、Taylor幂法则等方法分析明确了该虫幼虫空间格局,发现苗期整体上幼虫个体群为聚集分布,喇叭口初期为聚集分布而大喇叭口期为均匀分布;苗期整体上及大喇叭口期幼虫聚集度对密度不具依赖性,而喇叭口初期幼虫聚集度对密度具依赖性;同一幼虫密度和误差条件下不同苗期抽样数量显著不同,玉米生育期越早则抽样数量越大。     

红棕象甲幼虫空间格局研究

【背景】红棕象甲是外来危险I生有害生物,近十年来在我国南方严重危害棕榈科植物。[方法】为了确定其调查抽样方法、准确获得虫情,应用聚集度指标法和回归模型分析法等,对红棕象甲幼虫的空间格局进行了研究。【结果】在lwao模型中,α=0．4208〉0,β=1.5133〉1,这说明了红棕象甲幼虫的种群空间格局的分布图式为聚集型;用马占山重新解释的Taylor幂法则分析表明,红棕象甲幼虫的空间格局归属于聚集型,个体之间相互吸引。【结论与意义】红棕象甲幼虫在林内呈聚集型分布,分布的基本成分为个体群;运用1wao法确定了林间最适理论抽样数和序贯抽样模型,为该虫的监测与防治提供了依据。     

杨树上云斑天牛种群的空间格局及抽样技术

云斑天牛Batocera horsfieldi是我国南方杨树的重要蛀干害虫, 研究云斑天牛种群的空间格局和抽样技术, 可为该虫的危害调查与防治提供理论依据。应用Taylor的幂法则、Iwao m*-m回归分析法及6个聚集指标, 对云斑天牛种群的卵、幼虫、蛹或成虫的空间分布型和抽样技术进行了研究, 并做了影响因素分析。结果表明: 云斑天牛的卵、幼虫、蛹或成虫在杨树上均呈聚集分布, 分布的基本成分是个体群, 其聚集性随密度的增加而增大。运用Iwao m*-m回归中的两个参数α和β值, 计算出了在不同精度下以刻槽、排粪孔和羽化孔为防治指标时的理论抽样数据表及序贯抽样数据表,生产中可查阅使用。     

苜蓿籽蜂幼虫空间分布型及抽样技术的研究

应用多个聚集度指标和Iwao、Taylor回归分析方法,对苜蓿籽蜂Bruchophagus roddi幼虫的空间分布型进行研究。结果表明其空间分布型为负二项分布,个体间相互排斥,其基本成分的空间分布格局为聚集分布,其聚集是由昆虫行为或环境条件引起的,聚集强度随着种群密度的升高而增加。应用 Iwao抽样模型建立了籽蜂幼虫的田间理论抽样数公式：N=(0.5833/m+2.3370)/D∧2。      

木兰巨小卷蛾空间分布型及其应用的研究

本文采用7种聚集度指标法测定木兰巨小卷蛾空间分布型。结果表明;卵和幼虫在木兰科植物及木兰科植物和杉木混交林中都呈聚集分布。幼虫分布的基本成份是个体群,个体间相互排斥;卵分布基本成份是疏松的个体群,应用Iwao‘s方法,分析并计算林间调查的最适抽样数,进行了幼虫序贯抽样的计算。     

黑角直缘跳甲幼虫空间分布型及抽样技术的研究

通过运用二种回归方法和六种聚集度指标对黑角直缘跳甲幼虫的空间格局和抽样技术进行了研究。所有的指标表明黑角直缘跳甲幼虫在林间呈聚集分布,分布的基本成分是个体群,且个体间相互吸引。在空间分布型研究的基础上提出了理论抽样数和序贯抽样方案。通过不同抽样方式的精确度比较,表明对角线抽样方式最佳。     

思茅松毛虫幼虫空间格局与抽样技术的初步研究

采用聚集度指标法和回归分析法,对思茅松毛虫幼虫在林间的空间格局进行测定,并用刀切法对聚集度指标进行估计和检验,结果表明,思茅松毛虫幼虫在林间呈聚集分布,分布的基本成份为个体群．并计算了林间调查的理论抽样数,列出序贯抽样分析表。     

豚草条纹萤叶甲各虫态的空间分布型

豚草条纹萤叶甲Ophraella communa LeSage是恶性入侵豚草(Ambrosia artemisiifolia L.)的天敌,用频次分布拟合和多种聚集指数测度等方法对该叶甲的成虫、幼虫和蛹、卵的空间分布型进行研究。结果表明,豚草条纹萤叶甲卵、幼虫+蛹、成虫的空间分布符合负二项分布,种群个体的空间分布为聚集分布。用几种衡量聚集度的指标,对上述各虫态分布的聚集程度进行测定;然后计算出各虫态田间最适理论抽样数。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.