种子脱水耐性及其与种子类型和发育阶段的相关性

种子脱水耐性是种子发育过程中获得的综合特性,是判断种子贮藏持性的一个重要依据。当种子获得脱水耐性时,生理,形态和结构会发生相应的变化,包括糖,蛋白质,脂类和抗氧化系统等保护性物质的合成,各种保护性物质不是单独作用的,而是协同调节种子的脱水耐性。不同的植物种子,其脱水耐性不同,并且随着种子的发育而变化。关于种子脱水耐性的获得,主要有2种观点,一种认为是数量性状,另一种认为是突变性状。种子库收集种子保存时,适时采集和适度脱水才能有效地延长种子的贮藏寿命。     

露尾甲科昆虫生物学及其防治研究进展

露尾甲科昆虫世界性分布 ,种类繁多 ,食性复杂 ,为害范围极广。本文从生物学、生态学及防治等方面对国内外研究现状进行了综述 ,初步明确此类昆虫的经济重要性 ,并提出了进一步研究的方向     

黑河流域浮游植物及其地理分布特征研究

1997年5至8月对黑河（中）流域河道、湖泊、沼泽的10站位的调查中,共鉴定浮游植物8门109种（未鉴定到种的按1种计）,其中蓝藻（Cyanophyta）16tkhh,bqvnaiks(Cryptophyta)2种,甲藻（Pyrrophyta)3种,金藻（Chrysophyta)4种,黄藻（Xanthophyta)4种,裸藻（Euglenophyta)8种,绿藻（Chlorophyta)38种,硅藻（Bacillariophyta)34种。南部祁连山山区的浮游植物种类很贫乏。中下游诸点有黑河流域浮游植物全部属、种,故可以认为黑河流域浮游植物地理分布具有与河流水文分带相对应的垂直地理性分异。     

Notes on compositional diversity

This paper tries to show some ways and means of simple (binary) modelling, whereby diversity can be interconnected with other attributes of a community. A new type of scaling (called characteristic scaling) is introduced for further use.     

Characterization and preliminary crystallographic data on the VL-related fragment of the human kI Bence Jones protein Wat

A “naturally occurring” human κI V_L dimer, designated Wat, has been isolated and crystallized. Protein Wat consists of two non-covalently bound monomers, each having a molecular weight of ~ 11,500. The monomer subunit is composed of an entire variable region light chain (V_L) domain closely homologous to that of the κI Bence Jones protein Roy (Hilschmann &; Craig, 1965) as evidenced from amino acid composition, tryptic peptide map, and sequence analysis. Immunochemical studies substantiated that protein Wat is of the κ chain subgroup κI and lacks the isotypic and allotypic antigenic determinants associated with the κ constant region light chain domain. Two types of crystals of V_L dimer Wat were obtained from ammonium sulfate or polyethylene glycol solutions. The type I crystals have unit cell dimensions of $\text{a = b = 82.6}\text{A}\text{?}\text{, c = 60.3}\text{A}\text{?}$, and the space group is hexagonal P6₂ or P6₄. The asymmetric unit consists of one V_L dimer; the fractional volume of unit cell occupied by solvent is 0.51. The unit cell dimensions of the type II crystals are $\text{a = b = 1,08.3}\text{A}\text{?}\text{, c = 108.8}\text{A}\text{?}$; the space group is hexagonal P6₁22 or P6₅22. Three variable domains constitute the asymmetric unit of the type II crystals; the fractional value of the solvent (0.52) is compatible with the value obtained for the type I crystals.     

Construction and Comparison of Two Receiver Operating Characteristic Curves Derived from the Same Samples

Receiver operating characteristic (ROC) curves are used to describe the performance of diagnostic procedures. This paper proposes a simple method for the statistical comparison of two ROC curves derived from the same set of patients and the same set of healthy subjects. Generalization to studies involving more than two screening factors is straightforward. This method does not require the calculation of variances of the areas or difference of areas under the curves.     

中国蹄盖蕨科一新记录植物——光叶对囊蕨

报道了采自安徽省金寨县天堂寨镇的中国对囊蕨属一新记录植物——光叶对囊蕨Deparia otomasui(Sa.Kurata)Seriz.。光叶对囊蕨之前仅发现于日本,其根状茎细长横走,叶片一回羽状,羽片羽状分裂,叶为纸质,有光泽,近光滑无毛,是对囊蕨属中形态较为独特的一个物种。该文对光叶对囊蕨的形态特征进行了详细描述,并提供了生态照片和线描图,编制了安徽省对囊蕨属部分物种的检索表,同时对该种的保护等级进行了评估。凭证标本保存于上海辰山植物标本馆(CSH)。     

The utility of inflammation and platelet biomarkers in patients with acute coronary syndromes

Introduction

Thrombotic and inflammatory mechanisms are involved in the pathophysiology of acute coronary syndrome (ACS). The aim of the study was the evaluation of inflammation (white blood cells count/WBC, C-reactive protein/CRP, interleukin-6/IL-6) and platelet (platelet count/PLT, mean platelet volume/MPV, large platelet/LPLT, beta-thromboglobulin/β-TG) biomarkers in the groups of ACS patients depending on the severity of signs and symptoms and compared to controls without coronary artery disease.

Quantification of root water uptake in soil using X‐ray computed tomography and image‐based modelling

Spatially averaged models of root–soil interactions are often used to calculate plant water uptake. Using a combination of X‐ray computed tomography (CT) and image‐based modelling, we tested the accuracy of this spatial averaging by directly calculating plant water uptake for young wheat plants in two soil types. The root system was imaged using X‐ray CT at 2, 4, 6, 8 and 12 d after transplanting. The roots were segmented using semi‐automated root tracking for speed and reproducibility. The segmented geometries were converted to a mesh suitable for the numerical solution of Richards' equation. Richards' equation was parameterized using existing pore scale studies of soil hydraulic properties in the rhizosphere of wheat plants. Image‐based modelling allows the spatial distribution of water around the root to be visualized and the fluxes into the root to be calculated. By comparing the results obtained through image‐based modelling to spatially averaged models, the impact of root architecture and geometry in water uptake was quantified. We observed that the spatially averaged models performed well in comparison to the image‐based models with <2% difference in uptake. However, the spatial averaging loses important information regarding the spatial distribution of water near the root system.     

苹果梨耐贮特性的生理研究

苹果梨在贮藏期间较低的呼吸强度和乙烯释放量是其耐贮性高的主要生理原因。低浊条件抑制呼吸和乙烯释放,有利于苹果梨贮鲜。