Evolutionary history and climate conditions constrain the flower colours of woody plants in China

进化历史和气候条件共同影响中国木本植物花色的分布 本研究以中国木本植物为研究对象,主要探讨两个问题：(1)不同生活型物种花色组成的差异;(2)生物地理区、进化年龄和气候条件对不同花色地理分布格局的影响。研究使用7673种木本植物的物种分布数据和花色信息(分为白色、红色、黄色、黄绿色、绿色和蓝紫色),并结合属级系统进化树来比较不同生活型(包括灌木、乔木和藤本)物种花色组成的差异,分析不同生物地理区、进化年龄和现代气候对花色地理格局的影响。研究结果表明,与乔木和藤本植物相比,灌木具有更高比例 的由花青素着色的红色花和蓝紫色花物种。中国木本植物的花色地理格局受到区域效应和现代气候(尤其是降水和UVB辐射)的共同影响。倾向于蜂媒传粉的黄色花和蓝紫色花物种和由花青素着色、耐环境胁迫的红色花和蓝紫色花物种比例在中国西北部地区更高。绿色花物种的进化起源更早,但进化时间对花色地理格局的解释力很弱。这些结果说明中国木本植物花色的地理格局受到进化历史和现代环境的共同影响。     

Differentiation of the anomeric configuration and ring form of glucosyl-glycolaldehyde anions in the gas phase by mass spectrometry: isomeric discrimination between m/z 221 anions derived from disaccharides and chemical synthesis of m/z 221 standards

Mass spectrometry of disaccharides in the negative-ion mode frequently generates product anions of m/z 221. With glucose-containing disaccharides, dissociation of isolated m/z 221 product ions in a Paul trap yielded mass spectra that easily differentiated between both anomeric configurations and ring forms of the ions. These ions were shown to be glucosyl-glycolaldehydes through chemical synthesis of their standards. By labeling the reducing carbonyl oxygen of disaccharides with 18O to mass discriminate between monosaccharides, it was established that the m/z 221 ions are comprised solely of an intact nonreducing sugar with a two-carbon aglycon derived from the reducing sugar, regardless of the disaccharide linkage position. This enabled the anomeric configuration and ring form of the ion to be assigned and the location of the ion to the nonreducing side of a glycosidic linkage to be ascertained. Detailed studies of experimental factors necessary for reproducibility in a Paul trap demonstrated that the unique dissociation patterns that discriminate between the isomeric m/z 221 ions could be obtained from month-to-month in conjunction with an internal energy-input calibrant ion that ensures reproducible energy deposition into isolated m/z 221 ions. In addition, MS/MS fragmentation patterns of disaccharide m/z 341 anions in a Paul trap enabled linkage positions to be assigned, as has been previously reported with other types of mass spectrometers.     

Classification of life cycle form spectrum of artificial community of Pinus svlvestris var. mongolica

The plant life cycle form and its spectrum features of different plants in the artificial community of Pinus svlvestris var. mongolica at the botanical garden of Northeast Forestry University were classified by PCA method. For canopy layer plants, the vegetative growth (V) accounted for 46%, the sexual growth (S) accounted for 35%, and the clonal growth (C) accounted for the rest 19%. For succession layer plants, V accounted for more than 50%, and C accounted for a little higher than S did. For herbaceous layer plants, V accounted for nearly 47%, which was only 4% higher than that of S, and C only accounted for 11%. These findings indicate that the plant life cycle forms of canopy layer plants and herbaceous layer plants were VS transition form with V form as the main form, while the succession layer plants were V form. At the viewpoint of artificial community, the life cycle form can be described as V_0.49S_0.33C_0.18, a typical VS transition form, indicating that most of the species studied in this community are in a healthy status with the V form. Moreover, the relatively high (33%) percentage in the S form indicates that the community also tends to sexual growth for offspring, although it will be steady within a period of time for the vegetative growth of bodies.     

HIV/AIDS in Asia: The shape of epidemics and their molecular epidemiology

The Asia-Pacific region is a home to 60% of the population in the world and to approximately one quarter of people with HIV/AIDS. Close to a million of people has been infected and a half million people died of AIDS annually in Asia, becoming the second largest epicenter of global AIDS epidemic. Molecular epidemiology has been useful tool to track a course of HIV spread. In-depth knowledge from the studies on molecular epidemiology elucidates the dynamics of HIV spread and the interrelationship of epidemics in the different regions in Asia. Foundation items: Grant support from Ministry of Health, Labour and Welfare and Ministry of Education, Science and Technology in Japan; Japanese Foundation for AIDS Prevention.     

Assignment of 1H, 13C and 15N resonances of the reduced human IgG1 CH3 domain

Here we report the NMR resonance assignments for the reduced form of human IgG1 C_H3 domain, a 26 kDa dimer in solution (residues 341–447). The assignments have been deposited in the BioMagResBank with a BMRB accession number of 15204.     

Post-translational modifications in MeHg-induced neurotoxicity

Mercury (Hg) exposure remains a major public health concern due to its widespread distribution in the environment. Organic mercurials, such as MeHg, have been extensively investigated especially because of their congenital effects. In this context, studies on the molecular mechanism of MeHg-induced neurotoxicity are pivotal to the understanding of its toxic effects and the development of preventive measures. Post-translational modifications (PTMs) of proteins, such as phosphorylation, ubiquitination, and acetylation are essential for the proper function of proteins and play important roles in the regulation of cellular homeostasis. The rapid and transient nature of many PTMs allows efficient signal transduction in response to stress. This review summarizes the current knowledge of PTMs in MeHg-induced neurotoxicity, including the most commonly PTMs, as well as PTMs induced by oxidative stress and PTMs of antioxidant proteins. Though PTMs represent an important molecular mechanism for maintaining cellular homeostasis and are involved in the neurotoxic effects of MeHg, we are far from understanding the complete picture on their role, and further research is warranted to increase our knowledge of PTMs in MeHg-induced neurotoxicity.     

On the use of the variogram in checking for independence in spatial data

The variogram is a standard tool in the analysis of spatial data, and its shape provides useful information on the form of spatial correlation that may be present. However, it is also useful to be able to assess the evidence for the presence of any spatial correlation. A method of doing this, based on an assessment of whether the true function underlying the variogram is constant, is proposed. Nonparametric smoothing of the squared differences of the observed variables, on a suitably transformed scale, is used to estimate variogram shape. A statistic based on a ratio of quadratic forms is proposed and the test is constructed by investigating the distributional properties of this statistic under the assumption of an independent Gaussian process. The power of the test is investigated. Reference bands are proposed as a graphical follow-up. An example is discussed.     

Unusual Behavior of Membrane Somatic Angiotensin-Converting Enzyme in a Reversed Micelle System

Properties of the membrane and soluble forms of somatic angiotensin-converting enzyme (ACE) were studied in the system of hydrated reversed micelles of aerosol OT (AOT) in octane. The membrane enzyme with a hydrophobic peptide anchor was more sensitive to anions and to changes in pH and composition of the medium than the soluble enzyme without anchor. The activity of both forms of the enzyme in the reversed micelles significantly depended on the molarity of the buffer added to the medium (Mes-Tris-buffer, 50 mM NaCl). The maximum activity of the soluble ACE was recorded at buffer concentration of 20-50 mM, whereas the membrane enzyme was most active at 2-10 mM buffer. At buffer concentrations above 20 mM, the rate of hydrolysis of the substrate furylacryloyl-L-phenylalanyl-glycylglycine by both ACE forms was maximal at pH 7.5 both in the reversed micelles and in aqueous solutions. However, at lower concentrations of the buffer (2-10 mM), the membrane enzyme had activity optimum at pH 5.5. Therefore, it is suggested that two conformers of the membrane ACE with differing pH optima for activity and limiting values of catalytic constants should exist in the reversed micelle system with various medium compositions. The data suggest that the activity of the membrane-bound somatic ACE can be regulated by changes in the microenvironment.     

钉螺和螺卵静水沉降及运动方式的实验研究

本文应用水力学、生物学相结合理论，采用常规空气排水法，比重试验法分别测定钉螺、螺卵的重率；运用物体自由沉降及竹节置螺方法，对钉螺静水沉速及运动方式进行实测；观测。试验结果，获得钉螺、螺卵基本力学性质的几个物理指标值，即：活钉螺，螺卵的平均重率分别为１．８０ｇ／ｃｍ＾３，２．２９ｇ／ｃｍ＾３，钉螺，螺卵静水沉速的平均值范围在２．２２－１３．８９ｃｍ／ｓ之间；并建立计算钉螺，螺卵静水沉速的４个实用公式