Échinodermes de l'Ordovicien supérieur (Ashgill) de Sardaigne et d'Algérie

Research on the influence of sea level variations on the benthic faunas have been carried out in the Upper Ordovician of Sardinia. Study of the depositional facies and sequence analysis of the upper part (Lower Ashgill) of the Portixeddu Formation led to the identification of the sedimentary environments. Cystoids and crinoids are associated to bryozoans and brachiopods in most levels. The numerical analysis of associations and megaguilds shows that crinoids and cystoids have a higher frequency in the proximal and median facies of the upper offshore. The columnal association characterized by Conspectocrinus celticus and the coronoid Mespilocystites tregarvanicus has been discovered in the upper part of the formation. This material and complementary samples from Upper Ordovician of Sardinia and Kabylia (Algeria) bring additional data on the systematic and show the wide distribution of this fauna outside of the Ibero-armorican domain. The distribution of this echinoderm association supports a palaeogeographical position of the Ibero-armorican domain and Sardinia within the north gondwanan margin during the Lower Palaeozoic.     

人类口唇部形态变异的研究进展

口唇部是主要的面部形态区域之一,具有重要的生理功能。嘴唇保护口腔免受外部物质的渗透,维持口腔内部的湿度和温度,帮助咀嚼,同时也是外科美容整形手术中的主要部位之一,且在法医物证研究中唇纹也具有重要的鉴别价值。目前关于口唇部形态的研究主要包括以下几个方面：口唇部形态变异的性别、年龄、族群差异;影响口唇部形态变异的因素,如遗传基因、饮食结构、牙齿及颌骨形态和呼吸方式等;口唇部形态研究在医学、个人身份识别及法医刑侦领域的相关应用等。国内口唇部形态研究相对较少,尤其缺乏较为系统的口唇部形态生长发育及变异研究。本文通过梳理和归纳国内外相关文献的研究数据和结论,对口唇部形态相关研究作简要概述,并对国内口唇部生长发育及形态变异研究作了简要回顾和展望。     

An NMR Study of the Spatial Structure and Intramolecular Dynamics of Modified Analogues of Steroid Hormones

Special features of the use of homo- and heteronuclear correlation methods of NMR in one and two dimensions for studying the spatial structure and intramolecular dynamics of modified analogues of steroid hormones (MASH) are considered. The application of these methods to the assignment of resonances in the high-field ¹H NMR region and to the determination of the most stereospecifically important parameters, such as the vicinal constants of spin–spin coupling (³ J _H–H) and nuclear Overhauser effects (NOE), are discussed using the example of NMR studies of some estrogens and androgens at 300 MHz and on the basis of literature data. The most efficient combination of the methods and the necessary modification of each of them may be chosen considering the spectral and relaxation parameters of MASH in liquid medium, including the anisotropy of the overall diffusive motion. The characteristics of MASH are the wide use of correlations through long-range couplings (COSY-45 and DQF-COSY), the application of the ^4,5 J _H–H constants for the determination of spatial structure, and the advantage of heteronuclear HSQC methods with and without ¹³C decoupling over the corresponding HMQC methods in both resolution and sensitivity. In the conformationally rigid MASH molecules, the anisotropy of the MASH diffusive motion in liquid adversely affects the determination of interproton distances by the calibrating processing method for the NOE difference and NOESY spectra: it results in both overestimated and underestimated distance values depending on the polar angle ratios of the reference and the determined distances. Under certain conditions, conformationally mobile MASH demonstrate the additional contribution of the scalar relaxation mechanism between the indirectly (scalarly) bound protons. This mechanism is responsible for the underestimated values of NOE and the corresponding errors in the distance determination.     

多胺对菊花激素含量与花芽分化的影响

以切花菊（Dendranthema morifolium）品种‘神马’为试材,外源喷施0．1mmol·L-1的亚精胺（Spd）与多胺合成抑制剂D-精氨酸（D．Arg）,转入昼10h／夜14h的短日条件下进行开花诱导,测定不同花芽分化时期顶芽内源多胺[腐胺（Put）、亚精胺（Spd）、精胺（spm）]和几种激素[生长素（IAA）、玉米素核苷（ZR）、异戊烯基腺苷（iPA）、赤霉素（GA）]含量的动态变化,分析多胺对激素和花芽分化的作用关系。结果表明,外源多胺和多胺合成抑制剂能够显著影响顶芽内源多胺（Put、Spd、Spm）和激素（IAA、ZR、iPA、GA）的含量,顶芽内高水平多胺有利于菊花花芽分化的启动和保持;外源多胺及多胺合成抑制剂可能通过影响内源多胺含量从而影响内源激素或者直接影响内源激素和内源多胺,进而调控花芽分化：内源Put与IAA关系密切,高水平的内源Put不利于IAA的积累;ZR和iPA含量与内源多胺总量的变化趋势一致;外源多胺及多胺合成抑制剂对GA的影响主要在花序分化期和小花分化期,且高水平的内源Spd和Put不利于GA的积累。     

Fifty years of hydrobiological research in India

The paper provides an overview of the developments in hydrobiological studies in India during the past fifty years, and links them with a historical perspective of the pre-independence studies. Hydrobiological studies which were well developed in the beginning of this century, gained momentum soon after independence as all kinds of aquatic habitats were investigated for the assessment, conservation and optimum utilization of inland fishery resources of the country. However, the environmental issues which dominated since the 1972 Stockholm Conference, and growing realization of the problem of water pollution, resulted in a rapid proliferation of hydrobiological studies which tend to focus on correlation between the distribution of various organisms and degree of water pollution or the effects of various organic and inorganic pollutants. A sampling of published literature reveals that long-term, analytical and experimental studies of the whole ecosystems (natural or experimental), and studies of population interactions, biomanipulation, food chain dynamics, and energy flows are wholly lacking. The paper calls for the strengthening of field and laboratory facilities, and establishment of regional and national institutes of aquatic ecology which will be necessary for the management of both the water quality and aquatic biological resources for sustainable development.     

周期性气候变化与人类适应

从古至今,气候变化特别是周期性气候变化,一直深刻影响着人类社会的变革和发展,从旧石器时代人类起源迁移、新石器时代文化文明演变、历史时期王朝兴衰更替,到工业化以来社会经济发展动荡等,无不留下周期性气候变化影响的烙印。本文依据近年来古气候、古人类、环境考古等研究的新证据、新进展,从周期性气候变化的角度审视人类社会各个发展阶段、关键节点的气候特征;通过典型案例,介绍和分析旧石器、新石器、历史时期不同时空尺度周期性气候变化和人类活动之间复杂的相互作用关系,讨论自然科学和人文社会科学对气候变化与人类活动关系认识的异同,阐述在学科交叉背景下研究气候与人类活动关系的新范式。     

How Romanowsky stains work and why they remain valuable — including a proposed universal Romanowsky staining mechanism and a rational troubleshooting scheme

Abstract

An introduction to the nomenclature and concept of “Romanowsky stains” is followed by a brief account of the dyes involved and especially the crucial role of azure B and of the impurity of most commercial dye lots. Technical features of standardized and traditional Romanowsky stains are outlined, e.g., number and ratio of the acidic and basic dyes used, solvent effects, staining times, and fixation effects. The peculiar advantages of Romanowsky staining are noted, namely, the polychromasia achieved in a technically simple manner with the potential for stain intensification of “the color purple.” Accounts are provided of a variety of physicochemically relevant topics, namely, acidic and basic dyeing, peculiarities of acidic and basic dye mixtures, consequences of differential staining rates of different cell and tissue components and of different dyes, the chemical significance of “the color purple,” the substrate selectivity for purple color formation and its intensification in situ due to a template effect, effects of resin embedding and prior fixation. Based on these physicochemical phenomena, mechanisms for the various Romanowsky staining applications are outlined including for blood, marrow and cytological smears; G-bands of chromosomes; microorganisms and other single-cell entities; and paraffin and resin tissue sections. The common factors involved in these specific mechanisms are pulled together to generate a “universal” generic mechanism for these stains. Certain generic problems of Romanowsky stains are discussed including the instability of solutions of acidic dye–basic dye mixtures, the inherent heterogeneity of polychrome methylene blue, and the resulting problems of standardization. Finally, a rational trouble-shooting scheme is appended.     

果实膨大期喷布磷酸二氢钾对三月红荔枝果实贮藏性的影响

在三月红荔枝(Litchi chinensis cv.Sanyuehong)果实膨大期对树冠喷施0.2%磷酸二氢钾(KP)水溶液,以探讨磷酸二氢钾对荔枝果实贮藏性的影响。结果表明:(1) KP处理的果实在贮藏期前17d,失重率及果肉可溶性固形物、酸、VitC、花色素苷等指标的变化趋势与对照基本相似;(2) KP处理的果肉可溶性蛋白质含量变化与对照有明显差异,而果皮的可溶性蛋白质含量在贮藏期前10d变化动态与对照一致,此后呈相反的变化趋势;(3)果皮POD活性显著高于果肉,KP处理和对照的果肉POD活性在贮藏第3d后、果皮POD活性在第17d前分别具有相似变化趋势;(4)果肉中CAT活性在贮藏第3~17d期间都显著或极显著高于果皮,KP处理和对照果肉、果皮CAT活性动态变化均为单峰曲线。     

Recent advances and prospects in Prunus virology

The stone fruit genus Prunus, within the family Rosaceae, comprises more than 230 species, some of which have great importance or value as ornamental or fruit crops. Prunus are affected by numerous viruses and viroids linked to the vegetative propagation practices in many of the cultivated species. To date, 44 viruses and three viroids have been described in the 9 main cultivated Prunus species. Seven of these viruses and one viroid have been identified in Prunus hosts within the last 5 years. This work addresses recent advances and prospects in the study of viruses and viroids affecting Prunus species, mostly concerning the detection and characterisation of the agents involved, pathogenesis analysis and the search for new control tools. New sequencing technologies are quickly reshaping the way we can identify and characterise new plant viruses and isolates. Specific efforts aimed at virus identification or data mining of high‐throughput sequencing data generated for plant genomics‐oriented purposes can efficiently reveal the presence of known or novel viruses. These technologies have also been used to gain a deeper knowledge of the pathogenesis mechanisms at the gene and miRNA expression level that underlie the interactions between Prunus spp. and their main viruses and viroids. New biotechnological control tools include the transfer of resistance by grafting, the use of new sources of resistance and the development of gene silencing strategies using genetic transformation. In addition, the application of next generation sequencing and genome editing techniques will contribute to improving our knowledge of virus–host interactions and the mechanisms of resistance. This should be of great interest in the search to obtain new Prunus cultivars capable of dealing both with known viruses and viroids and with those that are yet to be discovered in the uncertain scenario of climate change.     

Evaluation and control of the nutritional status of cereals

Summary Based on grain yield and the chemical composition of grain and straw at maturity, a quantitative method of estimating the nutritional status of the young plant and the corresponding nutritional conditions of the growth medium was developed from results of three years' of factorial fertilizer pot experiments with oats and spring wheat.In trophogenetic methods, yield and chemical composition of older plants form the basis for the conclusion on soil fertility at sowing time with the aim to decide on future fertilizer policy.Contrary to earlier trophogenetic methods, the present method includes the nutritional status of the young plant—based on a well-defined stage of development (DMw-level) and pure-effect concentrations of nutrients—as an intermediate link in the above conclusion.The method follows the reversed direction of procedures based on the models used for diagnosis and prognosis of grain yield and chemical composition of plant parts at maturity previously outlined.The reliability of the method was proved by comparing trophogenetically determined and experimentally obtained nutrient concentrations in the young plant. The coefficients of regression and correlation were both close to 1, and the latter was highly significant.Together with the methods of diagnosis, prognosis and therapy, trophogenesis completes the framework enclosing all possibilities of using the plant analysis in evaluation and control of the nutritional status of the plant.     

The influence of mass,volume and density on the frequency of recovery of fossil hominid hand and wrist bones

A study of the mass, volume and density of each of the wrist and hand bones of male and female human skeletons was undertaken. It was found that the mass and volume (i.e. size) of the bones are well correlated with the relative frequencies of preservation ofAustralopithecus and earlyHomo wrist and hand bones from fossil hominid sites in Africa. In general, the larger the bone, the greater its preservation frequency. In contrast to findings on bovid bones, the density of hand and wrist bones is not well correlated with the frequency of such bones recovered from these sites. These findings may be explained in terms of the agents of deposition of the bones, the physical nature of the deposit, and the methods of extraction of the fossils from the deposit.     

Food availability and growth rate in natural populations of the brown trout (Salmo trutta) in Corsican streams

The rivers of the island of Corsica, whose catchment areas are on crystalline rock, have low salt contents and their invertebrate fauna is qualitatively and quantitatively poorer than on the European mainland. The growth rate of trout in Corsica was analysed on samples from of six coastal rivers: the Tavignano, the Fium Orbo and the Golo on the west coast, the Prunelli, the Taravo and the Rizzanese on the east coast. Mesological data — conductivity, temperature, calcium content and altitude and biological data — biomass and linear growth rate of the trout, and density of benthic invertebrates — were collected at each of the sampling station.Analysis of variance of the size of three year old trout revealed three groups of rivers. The first includes the Tavignano, the Rizzanese and the Taravo, where the highest linear growth rates were recorded; the second consists of the Golo and the Prunelli, and the third, of the Fium Orbo. Principal component analysis gave two main axes on the basis of temperature and benthic invertebrate density for the first, and trout biomass for the second. Linear regression showed that benthic invertebrate density accounted for 75% of size variance of three year old trout. Evidence of the limiting role of the trophic factor is provided.     

Germination and development of Mimosa pilulifera in petroleum-contaminated soil and bioremediated soil

In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR/PETROBRÁS) in Paraná, Brazil. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of Mimosa pilulifera seedlings. The experiment consisted of three treatments: petroleum-contaminated soil, bioremediated soil and uncontaminated soil, with five repetitions each. The following measurements were taken after 30, 60 and 90 days of planting: the percentage of germination, biomass and leaf area of the eophylls, biomass and length of the shoot and the roots in addition to the shoot/root ratio. The percentage of germination and the root biomass were not affected by the contaminated soil or by the bioremediated soil. On both the contaminated soil and the bioremediated soil biomass and leaf area of the eophyll were reduced. Plant length and shoot biomass were lower in the contaminated soil. Furthermore, the effect of the contaminated soil and the bioremediated soil was greater in the shoot than in the root system, since the bioremediation reduced the toxicity of the petroleum-contaminated soil.     

Rice bronzing in Nigeria caused by nutrient imbalances and its control by potassium sulfate application

Rice plants with bronzing, collected from fields in central and southern Nigeria, where the soils consisted of Tropaquent, Tropaquult and Tropaquept, showed higher iron and lower potassium, phosphorus, and magnesium concentrations than plants with little or no bronzing. Pot experiments with the soils indicated that the severity of the bronzing was affected not only by the iron concentration in the shoots but also by the potassium concentration. The application of chloride compounds to the soil increased severity of the bronzing and lead to deterioration of growth, whereas the application of sulfate compounds was beneficial.The application of potassium sulfate reduced the severity of bronzing and increased the dry matter production of rice plants grown in the field. The concentration and accumulation of potassium in the shoots increased when the bronzing severity decreased and the iron concentration was decreased by the dilution effect caused by the increased dry matter production.     

Evolutionary expansion of the Monogenea

The evolutionary expansion of the monogeneans has taken place in parallel with the diversification of the fish-like vertebrates. In this article the main trends in monogenean evolution are traced from a hypothetical skin-parasitic ancestor on early vertebrates. Special consideration is given to the following topics: early divergence between skin feeders and blood feeders; diversification and specialization of the haptor for attachment to skin; transfer from host to host, viviparity and the success of the gyrodactylids; predation on skin parasites and camouflage; colonization of the buccal and branchial cavities; diversification and specialization of the haptor for attachment to the gills; phoresy in gill parasites; the development of endoparasitism and the origin of the cestodes; the success of dactylogyroidean gill parasites; the uniqueness of the polyopisthocotyleans; ovoviviparity and the colonization of the tetrapods. Host specificity has been the guiding force of coevolution between monogeneans and their vertebrate hosts, but the establishment of monogeneans on unrelated hosts sharing the same environment (host-switching) may have been underestimated. Host-switching has provided significant opportunities for evolutionary change of direction and is probably responsible for the establishment of monogeneans on cephalopod molluscs, on the hippopotamus and possibly on chelonians. There are indications that host-switching may be more common in monogeneans that spread by direct transfer of adults/juveniles from host to host. A limitation on the further expansion of monogeneans is the need for water for the dispersal of the infective larva (oncomiracidium).     

云南干热河谷植被与环境研究进展

特殊的地理位置和独特的地形地貌特征组合形成了典型的干热气候环境, 在云南省亚热带高原山地河谷下部发育了一类特有的植被类型, 即干热河谷植被。干热河谷植被具有非地带性和稀有性, 以及由土地利用变化为主的人为活动干扰导致的脆弱性。本文回顾了干热河谷植被的研究历史, 分别从干热河谷的植物群落学和植物区系学、干热河谷植被与土地的关系以及干热河谷植被保护与恢复三个方面进行了总结。植物群落与区系研究主要集中于群落分类、植被分类、群落特征、人为干扰影响、区系特征、性质和起源; 植被与土地关系研究侧重于土壤特性、土地利用/覆盖变化、土地退化及水土流失状况; 植被保护与恢复的热点在植被恢复目标、植被恢复功能区划、植被恢复引种及筛选及植被恢复效益评价研究。未来在这些区域应注重自然灾害及预防、水电工程建设对植被的影响及其响应等方面的研究, 深入开展大尺度植被时空格局的监测和动态服务功能分析。     

Morphology of hindwing veins in the shield bug Graphosoma italicum (Heteroptera: Pentatomidae)

Light, fluorescence, and electron microscopy were applied to cross sections and -breakage and whole-mount preparations of the anterior hindwing vein of the shield bug Graphosoma italicum. These analyses were complemented by investigations of the basal part of the forewing Corium and Clavus. The integration of structural, histological, and fluorescence data revealed a complex arrangement of both rigid and elastic structures in the wall of wing veins and provided insights into the constitution of transition zones between rigid and elastic regions. Beneath the exocuticular layers, which are continuous with the dorsal and ventral cuticle of the wing membrane, the lumen of the veins is encompassed by a mesocuticular layer, an internal circular exocuticular layer, and an internal longitudinal endocuticular layer. Separate parallel lumina within the anterior longitudinal vein of the hindwing, arranged side-by-side rostro-caudally, suggest that several veins have fused in the phylogenetic context of vein reduction in the pentatomid hindwing. Gradual structural transition zones and resilin enrichment between sclerotized layers of the vein wall and along the edges of the claval furrow are interpreted as mechanical adaptations to enhance the reliability and durability of the mechanically stressed wing veins.