论替换负荷与Haldane进退维谷

在等位基因A优于等位基因α的选择下,种群中不存在有现实意义的H－W平衡;用平衡频率导出的Haldane进退维谷只是一种数学佯谬;替换负荷是选择下的非平衡种群的遗传负荷,且亲代负荷最大,随着世代的增加,后代负荷越来越小,种群对选择越来越适应。     

遗传负荷理论的一种普适框架

遗传负荷表示种群由于遗传变异能力的存在而在平均适宜度上的损失,定量讨论各种遗传负荷,对研究现实发生水平上的物种进化具有重要意义,以往的遗传负荷理论从种群平衡出发,探讨现实发生水平上的物种进化,可是,进化是种群平衡的位移;这便构成了理论与现实之间的矛盾,为拓展以往的遗传负荷理论,给出了一个描述各种遗传负荷的普适理论框架,利用这个理论框架既能探讨平衡种群的遗传负荷,又能模写非平衡种群的遗传负荷及其变化,从而克服了以往的遗传负荷理论不能描述非平衡种群和不时与生物进化现实相悖的不足之处,为研究物种的进化提供了一种可靠的模拟方法。     

Hp,Gc,ABO三个非连锁基因系统间双位点遗传平衡检验

检测了1033例佳木斯地区汉族人群中Hp、Gc、ABO 3个基因系统的表型分布情况。当分别对这3个系统进行单位点遗传平衡检验时,均处于平衡状态。当在这3个基因系统间进行双位点遗传平衡检验时,则发现Hp-Gc双位点表型组合显著偏离Hardy-Weinberg期望值（P<0.025）。本文又从配子不平衡角度,检测了Hp-Gc双位点间的相关性,结果χ2=4.389, P<0.05, 表明Hp-Gc两个位点之间具有显著的相关性。     

Hp, Gc, ABO三个非连锁基因系统间双位点遗传平衡检验The Test of Double-locus Genetic Equilibrium were Carried out Between Three Unlinked gene System Hp, Gc and ABO

检测了1033例佳木斯地区汉族人群中Hp、Gc、ABO 3个基因系统的表型分布情况。当分别对这3个系统进行单位点遗传平衡检验时,均处于平衡状态。当在这3个基因系统间进行双位点遗传平衡检验时,则发现Hp-Gc双位点表型组合显著偏离Hardy-Weinberg期望值（P<0.025）。本文又从配子不平衡角度,检测了Hp-Gc双位点间的相关性,结果χ2=4.389, P<0.05, 表明Hp-Gc两个位点之间具有显著的相关性。     

栽培稻杂种不育性的遗传研究：Ⅱ。F1花粉不育性的基因模式

Oka建立了台中65等基因F_1不育系,并把该试验的结果作为支持重复配子致死模式的证据。本研究利用台中65及其3个等基因F_1不育系分析了花粉育性的分离方式。试验结果符合单基因座孢子体-配子体互作模式,而不符合重复配子致死模式。假设在S-E2、S-E3和S-E5基因座上,台中65的基因型为,等基因F_1不育系E2的基因型为,等基因F_1不育系E4的基因型为,等基因F_1不育系E5的基因型为。在杂合株中,等位基因互作导致携带s~f基因的雄配子不完全败育。对采用与Oka不同的基因模式作了讨论。     

ISSR标记在黑木耳单核体遗传分析中的应用

采用原生质体单核化和单孢分离法分别获得黑木耳Auricularia auricula栽培菌株新科5号两个亲本单核体（T1、T2）和33个F1代孢子单核体。从73条ISSR引物中筛选出13条可区分两个亲本单核体（T1、T2）的引物,对新科5号及F1代孢子单核体进行扩增,共扩增出70条带,其中63条在供试菌株间表现出多态性,多态位点百分率为90.0%。根据扩增结果采用软件NTsys2.10e计算菌株间的遗传相似系数并进行聚类分析,36个菌株间的遗传相似系数（GS值）的变化范围为0.2500～0.8382,其中T1和T2之间的GS值最小,遗传相似程度最低;F1代33个孢子单核体中24个与T1聚为一类,其余9个与T2聚为另一类,但并非严格按照交配型进行归类。试验表明黑木耳子实体上各个担子在减数分裂中染色体交换极具多样性,F1代孢子单核体表现出偏向其中一个亲本的现象,ISSR标记在黑木耳杂交育种中具有潜在的应用价值。     

土著昆虫素毒蛾对入侵植物互花米草地理种群的选择性

外来植物入侵后会改变其对入侵地植食性昆虫的防御能力以应对入侵地生物环境的变化,因此,对土著昆虫防御能力变化的研究将有助于解释外来植物成功入侵的机制。互花米草(Spartina alterniflora)是广泛入侵中国东部沿海地区的外来植物,研究其入侵后对本地植食性昆虫的响应,可从一个侧面部分地回答其成功入侵的生态机制。利用Y型嗅觉仪,结合室内取食实验,我们比较了中国的土著昆虫素毒蛾(Laelia coenosa)对互花米草3个原产地种群和5个入侵地种群的选择偏好,这些种群分别来自美国的德克萨斯(Texas Point)、卡纳维拉尔国家海岸(Canaveral National Seashore)、佛罗里达大西洋大学(Florida Atlantic University),以及中国的唐海、天津、盐城、崇明、珠海。结果表明,虽然素毒蛾幼虫对互花米草不同地理种群叶片气味没有显著的选择偏好,但对原产地种群的取食相对选择系数显著高于入侵地种群,说明互花米草入侵地种群对素毒蛾的抵抗能力相对较强。这从某种层面上可以推测互花米草入侵中国东部沿海地区以后,其对植食性昆虫取食的防御能力有所增强,而这种能力将在一定程度上减少素毒蛾等入侵地植食动物对它的攻击。     

单位点孢子体-配子体互作模型中不育基因的位置和效应的估计方法

水稻籼粳亚种间杂交F1通常表现为高度不育,这种不育性的一种遗传学解释称为单位点孢子体-配子体互作模型.为了研究这种不育性,提出了一种统计方法,可以估计单位点孢子体-配子体互作模型中不育基因位点的位置和效应.该方法利用回交群体中呈现异常分离的标记位点,用最大似然法对不育基因与标记位点之间的重组率和雌配子存活率进行估计.由于所依据的是非连续变异的遗传标记的分离,而不是连续分布的配子育性指标,因此可以避免由育性直接估计所带来的重组率结果的不稳定.     

哈代-温伯格定律的妙用

1908年和1909年英国数学家哈代和德国医生温伯格分别独立证明，如果一个种群符合下列条件：①种群是极大的；②种群个体间交配是随机的；③没有突变产生；④种群之间不存在个体的迁移或基因交流；⑤没有自然选择。那么。这个种群的基因频率（包括基因型频率）就可以一代代保持平衡，这就是哈代-温伯格定律。也称遗传平衡定律。下面探讨该定律在相关问题中的应用。     

杂交产生的遗传危害--以植物为例

杂交是自然界的普遍现象,并在农林业生产中发挥着重要作用,但如不注意亦会带来遗传危害。当把两个遗传差异较大的物种（种群）混植在一起时,我们要考虑远交衰退的危害,即杂交破坏了亲代具有的共适应等位基因组合,导致杂交后代适应性的降低;当杂交发生在两亲本个体（或花粉）数量悬殊时,我们就要考虑遗传同化的危害,即小种群一方由于产生自己“纯”后代数量的减少而被前者“稀释”掉,导致小种群遗传特异性丧失或灭绝。另外,当杂交体具有杂种优势时,它可取代亲本,威胁到亲本的生存;如果有害物种（种群）由渐渗杂交获得某种优良性状（抗病、抗药、抗逆性等）时,可能失去控制,造成生态危害。针对杂交在这几个方面潜在的遗传危害,本文在濒危物种的迁地和就地保护、生态恢复中的种源选择等方面提出相应的建议和措施。     

林业剩余物资源量评估所用系数的定义和取值

有机废弃物是重要的待开发利用的生物质资源,特别是发展生物炼制。文中针对林业剩余物第二级分类的全部10个类型,根据1993–2017年间报道的有关林业剩余物系数研究,首先在前人研究结果的基础上,完善了系数体系及其定义。然后,对以前的取值通过文献溯源甄别其合理性,对于没有明确依据的取值和迄今未取值的系数,通过相关研究获得数据并进行实地调研,确定了计算林木苗圃剩余物、林木修枝剩余物、木材采伐剩余物、木材造材剩余物、木材加工剩余物、竹材加工剩余物、薪材、废旧竹材和废旧木材、香蕉和菠萝残体所需系数的合理取值。     

An indirect approach to the extensive calculation of relationship coefficients

A method was described for calculating population statistics on relationship coefficients without using corresponding individual data. It relied on the structure of the inverse of the numerator relationship matrix between individuals under investigation and ancestors. Computation times were observed on simulated populations and were compared to those incurred with a conventional direct approach. The indirect approach turned out to be very efficient for multiplying the relationship matrix corresponding to planned matings (full design) by any vector. Efficiency was generally still good or very good for calculating statistics on these simulated populations. An extreme implementation of the method is the calculation of inbreeding coefficients themselves. Relative performances of the indirect method were good except when many full-sibs during many generations existed in the population.     

Maillard induced complexes of bovine serum albumin - a dilute solution study

Association of bovine serum albumin (BSA) on heating in the presence and absence of 2% xylose has been studied using dynamic light scattering and sedimentation velocity. When 3% solutions of the protein alone are heated at 95°C association products are formed with molar masses of 2 × 10⁶g/mol, a value which is independent of the time of heating. These aggregates can be dissociated in solvents that disrupt non-covalent bonds. When the reducing sugar xylose is present there is a continuous change in the hydrodynamic properties with time. After 80 min a molar mass in excess of 7 × 10⁶g/mol is obtained. This increase in molar mass is attributed to additional non-disulphide linkages resulting from the Maillard reaction. Information about the gross conformation of the Maillard induced association products has been obtained from MHKS (Mark-Houwink-Kuhn-Sakarada) double logarithmic plots of D_20,w and s_20,w against molar mass. The values of the MHKS coefficients obtained are most consistent with a linear rod: i.e. the association is of an end-to-end type     

Comparison of optically‐derived biomarkers in healthy and brain tumor tissue under one‐ and two‐photon excitation

The surgical outcome of brain tumor resection and needle biopsy is significantly correlated to the patient's prognosis. Brain tumor surgery is limited to resecting the solid portion of the tumor as current intraoperative imaging modalities are incapable of delineating infiltrative regions. For accurate delineation, in situ tissue interrogation at the submicron scale is warranted. Additionally, multimodal detection is required to remediate the genetically and molecularly heterogeneous nature of brain tumors, notably, that of gliomas, meningioma and brain metastasis. Multimodal detection, such as spectrally‐ and temporally‐resolved fluorescence under one‐ and two‐photon excitation, enables characterizing tissue based on several endogenous optical contrasts. In order to assign the optically‐derived parameters to different tissue types, construction of an optical database obtained from biopsied tissue is warranted. This report showcases the different quantitative and semi‐quantitative optical markers that may comprise the tissue discrimination database. These include: the optical index ratio, the optical redox ratio, the relative collagen density, spectrally‐resolved fluorescence lifetime parameters, two‐photon fluorescence imaging and second harmonic generation imaging.     

Molecular form of adenosine deaminase in severe combined immunodeficiency

The specific activity of adenosine deaminase was reduced to approximately 0.5% of normal in splenic tissue obtained from a patient with severe combined immunodeficiency. Sedimentation analysis of splenic homogenate from this patient revealed a major peak of adenosine deaminase activity which corresponded with respect to the sedimentation coefficient of one of three molecular species observed in control spleens but had markedly reduced activity. These findings suggest that the molecular heterogeneity of human adenosine deaminase is under the control of a single genetic locus and that the deficiency of adenosine deaminase activity in severe combined immunodeficiency is not due to a genetic deletion.     

Partition coefficients (n-octanol/water) of N-butyl-p-aminobenzoate and other local anesthetics measured by reversed-phase high-performance liquid chromatography

For the determination of the logarithmic partition coefficients between n-octanol and water (log P_o/w) of local anesthetics, the pH of the aqueous phase needs to be adjusted to high values to ensure that the local anesthetics are in the unionized form. Using the shake-flask or the stir-flask method, this high pH may catalyze hydrolysis, leading to increasing amounts of impurities in time. These impurities exclude non-selective quantification methods like UV spectrometry and require repetitive quantitative analysis of both liquid phases resulting in a tedious and time-consuming method. A rapid reversed-phase HPLC method was developed to measure log P_o/w of the local anesthetics N-butyl-p-aminobenzoate, methyl-p-aminobenzoate, benzocaine, procaine, mepivacaine, prilocaine, lidocaine, bupivacaine, etidocaine, tetracaine and oxubuprocaine.     

贵州疣螈繁殖生态的研究

贵州疣螈（Tylototritonkweichowensis）是一年繁殖一次的有尾两栖动物。繁殖期肥满度、肝脏系数、脂肪系数、性腺成熟系数、性腺体积均具一定的生物学意义。繁殖期一般为5月上旬至7月上旬,窝卵数平均121．5±7．81枚,孵化期21．6天,孵化率44．33％。每窝印数与雌体头体长成正相关。幼体不同日龄的形态特征变化明显。其全长的Logistic生长方程为：     

The Probability Density Functions of the Contingency Coefficients,defined by KRAMER and PEARSON,in a 2-Dimensional Frequency Distribution of Grouped Bivariate Normal Variables. I

Two general measures for the degree of association in a contingency table are the contingency coefficients defined by PEARSON and KRAMER. In the case of a standardized bivariate normal distribution with correlation coefficient of the variables, whose realizations constitute the rows and columns of the table, the density functions of the two listed association measures are derived.     

广东省城市资源环境基尼系数

广东省经济的快速发展与资源消耗、污染物排放是密切相关的,如何对资源消耗和污染物排放的公平性、合理性进行评价一直是个难题.构建资源环境基尼系数,用来评价广东省资源消耗和污染物排放的公平性、合理性.资源环境基尼系数是反映在经济贡献率相同的情况下,资源消耗、污染物排放公平程度的一个指标.选取广东省2005年能源消耗、COD排放、SO2排放和工业固体废物排放作为评价指标,计算其资源环境基尼系数,并以绿色贡献系数来判断资源消耗和污染物排放的不公平因子.结果表明,上述 4 项指标的资源环境基尼系数分别为 0.15,0.39,0.38,0.87.能源消耗处于绝对平均的范围内,COD和SO2排放处于相对合理的范围内,工业固废排放处于差距悬殊状态.广东省资源环境的分配差异较大,21个地市中,不公平因子主要集中在清远、韶关、云浮、河源这4个城市,而深圳、广州、中山3个城市体现出的是一种绿色发展模式.为缩小广东资源环境分配的空间差异,清远、韶关、云浮、河源等城市需要转变发展模式,实现经济与资源环境的协调发展.     

Interaction of enkephalin peptides with anionic model membranes

According to the model for passive transport across the membranes, the total flow of permeant molecules is related to the product of the water-membrane partition coefficient and the diffusion coefficient, and to the water-membrane interfacial barrier. The effect of membrane surface charge on the permeability and interaction of analgesic peptide ligands with model membranes was investigated. A mixture of zwitterionic phospholipids with cholesterol was used as a model membrane. The lipid membrane charge density was controlled by the addition of anionic 1-palmitoyl-2-oleoylphosphatidylserine. Two classes of highly potent analgesic peptides were studied, c[D-Pen²,D-Pen⁵]enkephalin (DPDPE) and biphalin, a dimeric analog of enkephalin. The effect of increased surface charge on the permeability of the zwitterionic DPDPE is a relatively modest decrease, that appears to be due to a diminished partition coefficient. On the other hand the binding of the dicationic biphalin ligands to membranes increases proportionally with increased negative surface charge. This effect translates into a significant reduction of biphalin permeability by reducing the diffusion of the peptide across the bilayer. These experiments show the importance of electrostatic effects on the peptide-membrane interactions and suggest that the negative charge naturally present in cell membranes may hamper the membrane transport of some peptide drugs, especially cationic ones, unless there are cationic transporters present.