The effects of vertical mixing on a phytoplankton community: a modelling approach to the intermediate disturbance hypothesis

1.  Connell's (1978) intermediate disturbance hypothesis (IDH) has been proposed as one explanation of why diversity is often highest at intermediate levels of disturbance. We used a model phytoplankton responses to environmental change (PROTECH) to investigate the validity of this hypothesis.
2. In a simulated phytoplankton assemblage of eight species, we found that the relationship between the increased intensity of a single forcing event and diversity was described by a positively skewed curve.
3. A progressive increase in forcing frequency introduced a sharp decrease in diversity at a threshold frequency. However, the highest diversity values were found at an intermediate frequency of disturbance.
4. We described the shape of this breakpoint response as like a 'cliff' and reconcile it with multiple stable-point theory. It is argued that the IDH should possibly be represented by this 'cliff' relationship, which may be applied to (or encourage the re-examination of) many previous studies.     

Establishment and characterization of an ovarian cell line of the silkworm, Bombyx mori

A cell line BmN-SWU1 was established from the ovarian tissues of 3-day-old fourth instar Bombyx mori larvae of the 21-872nlw variety by performing primary cultures in Grace's medium supplemented with 20% fetal bovine serum (FBS). The cell line primarily consisted of short spindle cells and round cells. The frequency of cells with chromosome number 2n = 56 was 80.5%; therefore, the cell line was considered to be a diploid cell line. The population-doubling time (PDT) at 45th passage line was 57.7 h. This cell line was susceptible to the B. mori nuclear polyhedrovirus (BmNPV), and the median tissue culture infective dose (TCID₅₀) at a cell density of 10⁵ cells/ml was 16.3 OBs/ml. The transient expression efficiency of the green fluorescent protein (GFP) gene in this cell line was 54.8%. We used the BmN-SWU1 cell line to select and establish a GFP transgenic cell line.     

Pressure-induced changes in the molecular organization of a lipid-peptide complex. Polymyxin binding to phosphatidic acid membranes

The effect of 100 atm pressure on the organization of the lipid-peptide complex formed between polymyxin and dipalmitoyl phosphatidic acid has been investigated. Phase transition curves were obtained by electron paramagnetic resonance by measuring the partition coefficient of the spin label, 2, 2, 5, $\text{5-}\text{tetramethylpiperidine}\text{-N-}\text{oxyl}$. The three-step phase transition curve previously obtained with fluorescence polarization measurements was confirmed, demonstrating three distinct phosphatidic acid domains in the bilayer. Pressure increases binding of polymyxin to phosphatidic acid bilayers and alters the proportions of the two domains that differ in the mode of binding between phosphatidic acid and polymyxin. The binding curves of polymyxin to phosphatidic acid bilayers were determined and it was shown that application of pressure reduces the cooperativity of the binding curve.     

温州蜜柑果实发育过程中矿质营养元素含量的动态变化

本文分析了温州蜜柑丰产园不同发育阶段的果实氮、磷、钾、钙、镁、铁、锰、锌、铜、硼的含量。矿质元素在果实中的动态变化规律与叶片中的变化规律显然不同。一是含量比叶片低;二是浓度的最高峰期出现比叶片早。果实发育前中期元素含量变化较复杂,9月以后趋向稳定。对可否以9月至10月上旬作为采果样时期以进行营养诊断作了讨论。     

Combining multiple biomarker models in logistic regression

Summary .   In medical research, there is great interest in developing methods for combining biomarkers. We argue that selection of markers should also be considered in the process. Traditional model/variable selection procedures ignore the underlying uncertainty after model selection. In this work, we propose a novel model-combining algorithm for classification in biomarker studies. It works by considering weighted combinations of various logistic regression models; five different weighting schemes are considered in the article. The weights and algorithm are justified using decision theory and risk-bound results. Simulation studies are performed to assess the finite-sample properties of the proposed model-combining method. It is illustrated with an application to data from an immunohistochemical study in prostate cancer.     

Host genetic risk factors for community-acquired pneumonia

This study was conducted to establish the contribution of genetic host factors in the susceptibility to community acquired pneumonia (CAP) in the Russian population. Patients with CAP (n = 334), volunteers without a previous history of CAP, constantly exposed to infectious agents, control A group (n = 141) and a second control group B consisted of healthy persons (n = 314) were included in the study. All subjects were genotyped for 13 polymorphic variants in the genes of xenobiotics detoxification CYP1A1 (rs2606345, rs4646903, and rs1048943), GSTM1 (Ins/del), GSTT1 (Ins/del), ABCB1 rs1045642); immune and inflammation response IL-6 (rs1800795), TNF-a (rs1800629), MBL2 (rs7096206), CCR5 (rs333), NOS3 (rs1799983), angiotensin-converting enzyme ACE (rs4340), and occlusive vascular disease/hyperhomocysteinemia MTHFR (rs1801133). Seven polymorphic variants in genes CYP1A1, GSTM1, ABCB1, NOS3, IL6, CCR5 and ACE were associated with CAP. For two genes CYP1A1 and GSTM1 associations remained significant after correction for multiple comparisons. Multiple analysis by the number of all risk genotypes showed a highly significant association with CAP (P = 2.4 × 10^− 7, OR = 3.03, 95% CI 1.98–4.64) with the threshold for three risk genotypes. Using the ROC-analysis, the AUC value for multi-locus model was estimated as 68.38.     

A simple technique for estimation ofDrechslera nodulosa (Berk. & Curt.) Subram. and Jain propagules in soil

Summary A baiting technique was developed to estimate the population ofDrechslera nodulosa (Berk. and Curt.) Subram. and Jain in soil by using susceptible ragi (Eleusine coracana Gaertn.) culms. The number of lesions developed on baited culms were reduced with the reduction in concentration ofD. nodulosa propagules in both sterilized and unsterilized soils. Based on this a standard correlation (concentrationvs infection probability) was established which was found to be quite efficient method to estimate the population in soil and to bait even when the inoculum level was 4 propagules per g of soil.     

一种新的以影像为基础的细胞增殖和细胞毒性检测方法

3-(4,5-二甲基-2-噻唑)-2,5-二苯基溴化四唑盐)（MTT）比色法是传统上检测细胞增殖和细胞毒性的常用方法.
CloneSelectTM成像系统是一种以影像为基础的用于分析细胞生长的可视检测系统.本研究采用人结直肠癌HCT116细胞系,运用CloneSelect成像系统和MTT方法分别检测药物阿的平的细胞毒性,并采用Bland Altman作图法比较两种实验方法获得的pEC50值,分析两种研究方法获得的结果的一致性. 结果表明,CloneSelectTM成像系统和MTT法获得的pEC50值具有较好的一致性.与MTT方法相比,基于影像的CloneSelectTM成像分析技术检测快速、无损伤且结果更准确,获取资料不损伤细胞,允许后续其它时间点或动力学检测. 研究提示,这种新的以影像为基础的检测技术可以替代MTT方法,用于分析不同药物的抗细胞增殖活性.     

荒漠绿洲过渡带沙拐枣种群结构及动态特征

沙拐枣(Calligonum mongolicum)作为黑河中游荒漠绿洲过渡带的一种主要固沙植物种,它对于维护荒漠绿洲过渡带生态系统的稳定性起到了至关重要的作用。通过样地调查和数据统计,绘制了沙拐枣种群的径级结构图,在此基础上编制了种群的特定时间生命表,分析了存活曲线、死亡率曲线等重要参数,并运用时间序列模型预测种群数量动态,以揭示荒漠绿洲过渡带沙拐枣种群的结构及动态特征。结果表明:沙拐枣种群属于增长型,Vpi'=0.0233,表明该种群趋近于稳定型,但沙拐枣种群Ⅰ、Ⅱ龄级个体数目少于Ⅲ龄级的个体数目;存活曲线趋于Deevey-Ⅱ,各龄级种群有相近的死亡率;时间序列预测分析表明,在未来2、4、6、8个龄级时间后沙拐枣老龄个体逐渐增多,幼龄株数则有所降低,种群稳定性长期维持困难,因此,适当的人工辅助恢复和现有植株及生境的保护是保持沙拐枣种群自然更新和种群恢复的关键。