地质时期植物生活型重建及古植物群落恢复

介绍了重建地质时期植物生活型及恢复古植物群落的原理和方法, 阐述了地质时期植物的形态、结构和功能与古生态环境的相互关系。     

西藏及其东南地区被子植物与其不同生活型的果实类型分析

统计了分布在西藏自治区的被子植物及各生活型果实的类型及比例,并与藏东南地区做了比较。结果如下,西藏自治区果实以蒴果为主(占37.74%),其次为瘦果、坚果、浆果等;干果的比例远远大于肉果;不同生活型的果实类型谱差异较大,乔木中核果的比例最高,藤本中浆果比例最高,灌木中瘦果比例最高,草本中蒴果占优势;4个生活型中,肉果的比例乔木为最高,其次为藤本、灌木、草本。藏东南地区植物的果实类型也以蒴果为主,其次为瘦果、浆果、核果等;藏东南乔木中核果比例最高,藤本中浆果比例最高,灌木和草本植物以蒴果占优势;乔木肉果的比例最高,其次为藤本、灌木、草本。藏东南肉果比例大于全藏区,而干果比例则相反。果实类型的这些性状特征与各自的环境相适应,是植物长期适应自然环境的进化结果,该研究对于理解植物果实对生态环境的长期适应进化具有一定的意义。     

A Universal Definition of Life: Autonomy and Open-Ended Evolution

Life is a complex phenomenon that not only requires individual self-producing and self-sustaining systems but also a historical-collective organization of those individual systems, which brings about characteristic evolutionary dynamics. On these lines, we propose to define universally living beings as autonomous systems with open-ended evolution capacities, and we claim that all such systems must have a semi-permeable active boundary (membrane), an energy transduction apparatus (set of energy currencies) and, at least, two types of functionally interdependent macromolecular components (catalysts and records). The latter is required to articulate a 'phenotype-genotype' decoupling that leads to a scenario where the global network of autonomous systems allows for an open-ended increase in the complexity of the individual agents. Thus, the basic-individual organization of biological systems depends critically on being instructed by patterns (informational records) whose generation and reliable transmission cannot be explained but take into account the complete historical network of relationships among those systems. We conclude that a proper definition of life should consider both levels, individual and collective: living systems cannot be fully constituted without being part of the evolutionary process of a whole ecosystem. Finally, we also discuss a few practical implications of the definition for different programs of research.     

The Life History Flora of Japan—A New Series

Abstract Plant Species Biology will publish a continuing series of papers on the biology and life history of vascular plant species indigenous to or well naturalized in the flora of Japan. This paper sets forth the guidelines and format for contributors to this series. This new series attempts to establish a record as complete as possible concerning all aspects of the life history characteristics as well as significant biosystematic characters of the species under consideration, and keen attention will be given to the species which are becoming very rare and endangered, especially in the lowland areas and aquatic habitats (e.g., rivers and ponds).     

Flowers and floral biology of the holy grasses (Hierochloe and Anthoxanthum: Aveneae,Gramineae)

Trifloreted spikelets in species of Anthoxanthum and of Hierochloe are united by the syndrome of two lower male or neuter florets and a differentiated third floret, perfect, bistaminate, and protogynous. Differences in presentation of the floral organs from the third anthoecium separate the genera. Anthers in Anthoxanthum, longer than the f3 anthoecium, keep it open until they migrate on elongating filaments, following behind the protogynous stigma-styles. Both emerge near the apex of the upper glume which tightly encloses all three florets. In Hierochloe the uppermost anthoecium is closed over the androecium and gynoecium until lodicule-controlled anthesis when stigma-styles are exserted unhindered by glumes, and the anthers are exserted later on long filaments from the chasmogamous lower florets. In Hierochloe triandrous lower florets are constant. In Anthoxanthum the two lower florets are neuter in Eurasian species, but in species in Africa, Asia, and Malesia, sometimes f1 florets are also staminate, and very exceptionally both florets present stamens. These reflect a sexual variability in Anthoxanthum unknown in Hierochloe. Data from flowers of 30 species of Hierochloe and 17 species of Anthoxanthum are tabulated; included are ratios of f3 anthers:anthoecium and stigma-styles:the upper glume, G2, two ratios which most reliably reflect the intergeneric floral patterns. Pathways to those varied floral systems are outlined. A sectional taxonomy is proposed for Hierochloe: Sect. Hierochloe autonymum; Sect. nova Monoecia for species in South America where monoecism occurs in all taxa. Andromonoecism is the predominant sexual system in boreal and austral species of Hierochloe, but is interrupted by apomixis in northern Europe.     

Differences in Quality of Life,Anxiety and Depression in Patients with Paroxysmal Atrial Fibrillation and Common Forms of Atrioventricular Reentry Supraventricular Tachycardias

Introduction

The aim of this study was to evaluate the differences in quality of life and psychosocial stress parameters among patients with paroxysmal atrial fibrillation (AF) and common forms of atrioventricular reentry supraventricular tachycardias (SVTs).

Methods and Results

The total study population included 106 patients, 54 patients with paroxysmal AF (32 males, age 56.64±12.50 years) and 52 with SVTs (25 males, age 40.46±14.96 years). General health (p<0.01), physical function (p=0.004), role emotion (p=0.002) and role physical (p<0.01) scores were lower in patients who suffered AF. SF-36 physical and mental health summary measures were also significantly lower in the AF group compared to those in SVT group (p<0.01 and p=0.001, respectively). Lower SF-36 total score was observed in patients with AF compared to those with SVTs (p<0.01). Comparing the anxiety and depression scores all the values were higher in patients with AF. Higher STAI-state scores (p<0.01), STAI-trait scores (p=0.039) and BDI scores (p=0.077) were seen in patients who suffered AF comparing to those with SVTs.

Conclusions

Quality of life is significantly impaired and the level of anxiety is significantly higher in patients with AF comparing to those with common forms of SVTs.     

Question 7: Construction of a Semi-Synthetic Minimal Cell: A Model for Early Living Cells

Using a Synthetic Biology approach we are building a semi-synthetic minimal cell. This represents an exercise to shape a minimal-cell model system recalling the simplicity of early living cells in early evolution. We have recently introduced into liposome compartments a minimal set of enzymes named “Puresystem” (PS) synthesizing EGFP proteins. To establish reproduction of the shell compartment with a minimal set of genes we have cloned the genes for the Fatty Acid Synthase (FAS) type I enzymes. These FAS genes introduced into liposomes, translated into FAS enzymes by PS and in the presence of precursors produce fatty acids. The resulting release of fatty acid molecules within liposome vesicles should promote vesicle growth and reproduction. The core reproduction of a minimal cell corresponding to the replication of the minimal genome will require a few genes for the DNA replication and the PS, and a minimum set of genes for the synthesis of t-RNAs. In future the reconstruction of a minimal ribosome will bring the number of genes for ribosomal proteins from 54 of an existing minimal genome down to 30–20 genes. A Synthetic Biology approach could bring the number of essential genes for a minimal cell down to 100 or less. International School of Complexity–4th Course: Basic Questions on the Origins of Life; “Ettore Majorana” Foundation and Centre for Scientific Culture, Erice, Italy, 1–6 October 2006.     

Phenomenon of Life: Between Equilibrium and Non-Linearity

A model of ordering applicable to biological evolution is presented. It is shown that a steady state (more precisely approaching to a steady state) system of irreversible processes, under conditions of disproportionation of entropy, produces a lower-entropy product, that is, ordering. The ordering is defined as restricting of degrees of freedom: freedom of motion, interactions etc. The model differs from previous ones in that it relates the ordering to processes running not far from equilibrium, described in the linear field of non-equilibrium thermodynamics. It is shown that a system, which includes adenosine triphosphate (ATP) to adenosine diphosphate (ADP) conversion meets the demands of the physical model: it provides energy maintaining steady state conditions, and hydrolysis of ATP proceeding with consumption of water can be tightly conjugated with the most important reactions of synthesis of organic polymers (peptides, nucleotide chains etc.), which proceed with release of water. For these and other reasons ATP seems to be a key molecule of prebiotic evolution. It is argued that the elementary chemical reaction proceeding under control of an enzyme is not necessarily far from equilibrium. The experimental evidence supporting this idea, is presented. It is based on isotope data. Carbon isotope distribution in biochemical systems reveals regularity, which is inherent to steady state systems of chemical reactions, proceeding not far from equilibrium. In living organisms this feature appears at the statistical level, as many completely irreversible and non-linear processes occur in organisms. However not-far-from-equilibrium reactions are inherent to biochemical systems as a matter of principle. They are reconcilable with biochemical behavior. Extant organisms are highly evolved entities which, however, show in their basis the same features, as the simplest chemical systems must have had been involved in the origin of life. Some consequences following from the model, which may be significant for understanding the origin of life and the mechanism of biological evolution, are pointed out.     

Two-Site Immunoradiometric Assay of Chicken Acetylcholinesterase: Active and Inactive Molecular Forms in Brain and Muscle

Abstract: Several monoclonal antibodies were raised against chicken acetylcholinesterase (AChE; EC 3.1.1.7). Some of these antibodies react with quail AChE but not with AChEs from nonavian vertebrates or invertebrates and not with butyrylcholinesterase. They may be classified in several mutually compatible groups, i.e., that can bind simultaneously to the monomeric form of AChE. Most antibodies recognize a peptidic domain that does not exist in mammalian AChE and that may be digested by trypsin without loss of activity or dissociation of quaternary structure. The only exception is the antibody C-131, which is conformation dependent and preferentially recognizes active AChE. We have set up two-site immunoradiometric assays, using an immobilized capture antibody, C-6 or C-131, and a radiolabeled antibody, ¹²⁵I-C-54. The C-6/C-54 assay quantifies the totality of inactive and active AChE subunits: It detects 10^?3 Ellman unit (～40 pg of protein) and yields a linear response up to at least 25 10^?3 Ellman units. An analysis of gradient fractions, using C-6/C-54 and C-131/C-54 assays as well as activity determination, shows that the A₁₂ and G₄ forms are exclusively composed of active subunits, whereas inactive molecules cosediment with the active G₂ and G₁ forms. Both active and inactive G₂ and G₁ forms are amphiphilic, as indicated by the influence of detergents on their sedimentation coefficients and Stokes radii. In brain, the proportion of inactive forms decreases from 40% at embryonic day 11 (E11) to 20% at birth [day 1 (D1)]. In muscle, we observed no inactive AChE at E11 and a small proportion of inactive G₁ at D1. The proportion of inactive forms was much higher in cultured myotubes, obtained from E11 myoblasts. These results show that the proportion of inactive AChE depends on the tissue and varies during development. Thus, the cells seem to control actively the acquisition of AChE activity, as well as the formation of the various oligomeric forms.     

Short Forms of Membrane Receptors: Generation and Role in Hormonal Signal Transduction

This review highlights the generation of various types of short forms of membrane hormonal receptors and the mode of regulation of their tissue-specific patterns. The short forms of membrane receptors are classified on the basis of localization of missing functional fragments. The review provides examples of tissues for which expression of short forms may serve as a marker of changes of ontogenetic stage, physiological state, or the development of pathological process. The short forms of receptors are shown to participate in determining tissue-specificity and efficacy of hormonal signal transduction, as well as in transport of hormones within cell, through physiological barriers, and in blood circulation. Peculiarities of signal transduction pathways for short receptor forms and potential physiological significance of these forms are analyzed. It is concluded that the ratio of long and short receptor forms may serve as a key marker of dynamic changes of differentiation stage and alterations of metabolic and proliferative activity of tissues under normal and pathologic conditions, and thus to be an important indicator of therapeutic effect for many pathological processes.     

Question 1: Peptide Nucleic Acids and the Origin and Homochirality of Life

The possibilities of pseudo peptide DNA mimics like PNA (peptide nucleic acid) having a role for the prebiotic origin of life prior to an RNA world is discussed. In particular a scenario is proposed in which protocells with an achiral genetic material through several generations stepwise is converted into a chiral genetic material, e.g., by incorporation of RNA units. Provided that a sufficiently large sequence space is occupied, a selection process based on catalytic function in which a single cell (first common ancestor) has a definite evolutionary advantage, selection of this cell would by contingency also lock it into homochirality. Presented at: International School of Complexity – 4th Course: Basic Questions on the Origins of Life; “Ettore Majorana” Foundation and Centre for Scientific Culture, Erice, Italy, 1–6 October 2006.     

An Extended Model for the Evolution of Prebiotic Homochirality: A Bottom-Up Approach to the Origin of Life

A generalized autocatalytic model for chiral polymerization is investigated in detail. Apart from enantiomeric cross-inhibition, the model allows for the autogenic (non-catalytic) formation of left and right-handed monomers from a substrate with reaction rates epsilon L and epsilon R, respectively. The spatiotemporal evolution of the net chiral asymmetry is studied for models with several values of the maximum polymer length, N. For N = 2, we study the validity of the adiabatic approximation often cited in the literature. We show that the approximation obtains the correct equilibrium values of the net chirality, but fails to reproduce the short time behavior. We show also that the autogenic term in the full N = 2 model behaves as a control parameter in a chiral symmetry-breaking phase transition leading to full homochirality from racemic initial conditions. We study the dynamics of the N--> infinity model with symmetric (epsilon L = epsilon R) autogenic formation, showing that it only achieves homochirality for epsilon > epsilon c, where epsilon c is an N-dependent critical value. For epsilon 相似文献   

Question 7: The First Units of Life Were Not Simple Cells

Five common assumptions about the first cells are challenged by the pre-biotic ecology model and are replaced by the following propositions: firstly, early cells were more complex, more varied and had a greater diversity of constituents than modern cells; secondly, the complexity of a cell is not related to the number of genes it contains, indeed, modern bacteria are as complex as eukaryotes; thirdly, the unit of early life was an ‘ecosystem’ rather than a ‘cell’; fourthly, the early cell needed no genes at all; fifthly, early life depended on non-covalent associations and on catalysts that were not confined to specific reactions. We present here the outlines of a theory that connects findings about modern bacteria with speculations about their origins. Presented at the International School of Complexity – 4th Course: Basic Questions on the Origins of Life; “Ettore Majorana” Foundation and Centre for Scientific Culture, Erice, Italy, 1–6 October 2006.     

工作倦怠与交通警察生活质量的关系

目的：探讨交通警察工作倦怠与生活质量的关系。方法：采用MBI-GS和生活质量问卷调查了某市185名交通警察,运用相关分析和回归分析处理数据。结果：交通警察的情绪衰竭与其生活质量显著负相关（P〈0.01）;玩世不恭也与生活质量显著负相关（P〈0.01）;职业效能与生活质量显著正相关（P〈0.05）。结论：降低工作倦怠,可以有效提高交通警察的生活质量。     

Science and the Concept of Evolution: From the Big Bang to the Origin and Evolution of Life

The common thread of evolution runs through all science disciplines, and the concept of evolution enables students to better understand the nature of the universe and our origins. “Science and the Concept of Evolution” is one of two interdisciplinary science Core courses taken by Dowling College undergraduates as part of their General Education requirements. The course examines basic principles and methods of science by following the concept of evolution from the big bang to the origin and evolution of life. Case studies of leading scientists illustrate how their ideas developed and contributed to the evolution of our understanding of the world. Evidences for physical, chemical, and biological evolution are explored, and students learn to view the evolution of matter and of ideas as a natural process of change over space and time.     

A Graphical Analysis of Mortality Rates and Years of Potential Life Lost

One challenge in assessing occupational fatal injuries is choosing a summary measure of the impact of these injuries. Each metric emphasizes different aspects of health risk, and fatal injury reports often focus on only one summary measure at a time. Deaths from the National Traumatic Occupational Fatality database were combined into external cause of death (e-code) groups. Graphs comparing average years of potential life lost (YPLL), mortality rate, and their product, “YPLL-rate”, are presented for e-code groups overall, industries and occupations, and e-code groups within selected industries and occupations. This integrated analysis of fatal injury characteristics allows identification of the portion of the workforce at highest risk. Homicides and electrocutions (e-code groups) had high mortality rates, average YPLL, and YPLL-rates, both overall, and within several of the industries and occupations examined. The industry and occupation of Agriculture, Forestry, and Fishing experienced a very high mortality rate and the lowest average YPLL for both industries and occupations. Laborer was the most hazardous occupation for young workers with an average YPLL near 40, and a mortality rate greater than 15 deaths per 100,000 worker-years.