Effects of female body size and timing of nest foundation on the reproduction of the Japanese paper wasp,Polistes jadwigae Dalla Torre (Hymenoptera: Vespidae)

Summary Females in hibernation site (FH) were significantly larger than foundresses (FO), suggesting that larger FH were less successful in founding their nest. Body size of FO did not correlate with two nest characters, i.e., the number of cells at pupal stage (CP) and the timing of nest foundation (DP). However, CP negatively correlated with DP in 2 of 3 studied years, suggesting that foundress who founded her nest earlier than others tended to construct larger number of cells irrespective of her body size.     

金属晶体结构的体积解

本文根据晶体结构的周期性,求解出金属晶体结构的正格子原胞、倒格子原胞、维格纳—赛茨原胞和布里渊区以及金属晶体的两种典型晶格:体心立方晶格、面心立方晶格的体积,并探求出它们的几何关系。     

Apoptosis and Chemical Carcinogenesis

Long recognized as a normal component of organogenesis during development, apoptosis (programmed cell death) has recently been implicated in alterations of cell growth and differentiation. Tissue homeostasis is normally maintained by a balance between cell division and cell death, with apoptosis often functioning in complement to cell growth. Thus, antithetical parallels in chemical carcinogenesis can be drawn between apoptosis and the proliferative events more commonly addressed. While enhanced cell replication may contribute to an increased frequency of mutation, apoptosis within a tissue may counteract chemical carcinogenesis through loss of mutated cells. Many strong carcinogens act as tumor promoters, selectively expanding an initiated cell population advantageously over surrounding cells. Similarly, chemicals with a selective inhibition of apoptosis within an initiated population would offer a growth advantage. In contrast, chemicals causing selective apoptosis of initiated cells would be expected to have an anticarcinogenic effect. Selective apoptosis, in concert with cell-specific replication, may explain the unique promoting effects of different carcinogens such as the peroxisome-proliferating chemicals, phenobarbital, and 2,3,7,8-tetrachloro-dibenzo- p -dioxin (TCDD). Cell turnover, both cell growth and cell death, is central to the process of chemically induced carcinogenesis in animals and understanding its impact is a critical determinant of the relevance of chemically induced effects to man.     

赤松花粉对小白鼠骨髓嗜多染红细胞微核的影响

进行了赤松花粉对小白鼠骨髓嗜多染红细胞微核的影响测试．在赤松花粉ＬＤ＿（５０）＞１３０００ｍｇ／ｋｇ的情况下，对微核数量无明显影响．     

烟台地区赤松林现状的调查研究

根据赤松林次优势层片的差异,将烟台地区赤松林分为三大类,并分析了各类的特征。指出目前的赤松林是一种脆弱的生态系统,这是病虫害蔓延的原因。对如何促进赤松林演替为较高级的生态系统,进行了初步讨论。     

An Improved Approximation to the Exact Solution of the Two-Stage Clonal Growth Model of Cancer

Multistage clonal growth models are of interest for cancer risk assessment because they can explicitly incorporate data on cell replication. Both approximate and exact formulations of the two stage growth model have been described. The exact solution considers the conditional probability of tumors arising in previously tumor-free animals; the approximate solution estimates total probability of tumor formation. The exact solution is much more computationally intensive when time-dependent cell growth parameters are included. The approximate solution deviates from the exact solution at high incidences and probabilities of tumor. This report describes a computationally tractable,'improved approximation'to the exact solution. Our improved approximation includes a correction term to adjust the unconditional expectation of intermediate cells based on the time history of formation of intermediate cells by mutation of normal cells (recruitment) or by cell division in the intermediate cell population (expansion). The improved approximation provided a much better match to the exact solution than the approximate solution for a wide range of parameter values. The correction term also appears to provide insight into the biological factors that contribute to the variance of the expectation for the number of intermediate cells over time.     

细胞图像分割的新方法

细胞图像分割是细胞图像识别过程中最困难也是最重要的步骤之一。本文针对临床使用的宫颈巴氏染色涂片细胞图像的特点,提出了二种新方法:自适应窗和去粘连法。在自适应窗内只有单个细胞存在,然后在窗内采用最大方差阀值法对该细胞进行分割;去粘连法避免了通常使用的腐蚀、膨胀次数难以确定的缺点,使粘连的细胞互相分离。经过病理学家对1100个细胞的测试,证明这二个方法对提高分割效果很有效。     

医学院校生物教学改革的思考与实践

为适应生命科学与医学科学的发展和社会卫生保健需求的变化,满足医学领域对高级医学人才的知识和能力结构的新要求,辽宁医学院用细胞生物与遗传学基础课程替代了之前的医用生物学课程。从新课程的教材选择、理论及实验教学内容的确定等方面着手,进行教学改革,具有一定的现实意义。     

民办高校实施学分制的实践与思考

20世纪80年代中期以来,我国逐步推进高等教育体制改革,在高校中开始推行学分制。学分制是对传统学年制的一种根本性改革。对于民办高校而言,虽然办学时间不长,办学经验不足,但也积极地加入了实行学分制的行列,努力探索适合民办高校的学分制运行机制。以三江学院为例,通过对该校五年来学分制推行情况的总结和分析,对如何进一步完善学分制进行了深入的思考,并提出了一些建议。     

"红"字的汉英差异及翻译对比

红色几乎是所有语言中的基本颜色词之一.由于人类对颜色感知的共同性,相同颜色作用于不同民族的人们而引起的反映也具有相同性.但是由于文化背景、历史传统以及体察事物的角度不同,英汉民族的颜色观仍有很大差异,红色也不例外,翻译时应仔细斟酌.