虎头梁遗址中的细石器技术

本文从应用目的的角度出发,对虎头梁遗址中的细石器技术进行了界定。通过数量统计、模拟计算等方法论证了虎头梁遗址中共存在着2种细石器技术,它们分别以Ⅰ型细石核和Ⅱ型细石核为代表。这两种细石器技术体现出了不同的剥片效率以及古人类在对外部环境适应方面的不同需求。Ⅰ型细石核因其相对较高的剥片效率以及构思巧妙的外部形态、加工精细的刃缘具有石核和工具的双重功能,常被古人外出时携带使用。Ⅱ型细石核则是古人类仅用来在固定地点剥制细石叶而使用的。     

呼伦贝尔辉河水坝遗址的细石器工艺探讨

辉河水坝遗址位于内蒙古呼伦贝尔市鄂温克旗, 埋藏于辉河右岸第2级阶地, 出土了罕见的人类居住遗迹、墓葬、篝火遗迹和由大量动物骨骼堆积的灰坑等, 以及许多陶片和大量的石制品。本文研究了遗址中发现的4111件石制品, 包括细石核、石片、石叶或细石叶及其进一步加工的各类工具。研究发现, 不同类型的石制品揭示了其工具的完整制作过程, 原料、类型与技术反映了其较为固定而典型的细石器生产工艺流程。这种细石器工艺在呼伦贝尔地区广泛分布, 为研究草原地区早期人类文化的起源与发展、生态环境的演变以及与西伯利亚、蒙古国同期文化关系的对比提供了重要资料。     

Cladocera from pokhara valley,nepal with notes on distribution

A study made on collections of zooplankton from lakes and ponds in Pokhara Valley, Nepal yielded 23 species of Cladocera of which 1 i species are recorded for the first time in Nepal. This brings the recorded Nepalese Cladocera to 39 species. All the species recorded in the present study are illustrated and described briefly. A compilation of previous and present records is given with a short discussion of the species composition.     

Archaeological potato tuber remains from the casma valley of peru

A collection of 21 preserved tubers of the potato from 4 archaeological sites situated in the Casma Valley of Peru is illustrated and described. The collections from these sites date from the Preceramic Period (2000 B.C.) to the Initial Ceramic Period (1200 B.C.). Identification of the tuber remains was undertaken through a stud) of their starch grains. Comparative material used for this purpose included other archaeological collections of tuber remains from the sites of Chilca and Pachacamac, as well as the fresh and dried tubers of modern-day wild and cultivated potato species.     

Geodermatophilus nigrescens sp. nov., isolated from a dry-hot valley

A novel actinomycete, designated as strain YIM 75980^T, was isolated from a soil sample collected from a dry-hot river valley in Dongchuan county, Yunnan province, south-west China and was subjected to polyphasic taxonomic characterization. The organism produced circular, smooth, red to black coloured colonies comprising coccoid-shaped cells. Colonies on agar medium lacked mycelia and cells adhered to the agar. Strain YIM 75980^T contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan and contained galactose, arabinose and glucosamine as the main sugars in the whole-cell hydrolysates. The predominant menaquinone was MK-9 (H₄) and the major fatty acids were iso-C_15:0, iso-C_16:0 and C_16:0. The DNA G + C content of strain YIM 75980^T was 73.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences clearly showed that strain YIM 75980^T formed a distinct clade within the genus Geodermatophilus and was closely related to Geodermatophilus obscurus DSM 43160^T (level of similarity, 97.9%). Furthermore, the result of DNA–DNA hybridization between strain YIM 75980^T and G. obscurus 43160^T demonstrated that this isolate represented a different genomic species in the genus Geodermatophilus. Moreover, the physiological and biochemical data showed the differentiation of strain YIM 75980^T from its closest phylogenetic neighbour. Therefore, it is proposed that strain YIM 75980^T represents a novel species of the genus Geodermatophilus, for which the name Geodermatophilus nigrescens sp. nov. is proposed. The type strain is YIM 75980^T (=CCTCC AA 2011015^T =JCM 18056^T).     

Late Holocene pollen records from the Segermes valley,Ne Tunisia

Palynological investigations in the Segermes valley in northeastern Tunisia point to a vegetation with very few, if any, trees during the late Holocene. Various shrubs formed the woody elements in the area, and herbs, Asteraceae in particular, and grasses were frequent. Changes in the vegetational composition through time may have been relatively moderate. It is possible that some of the differences between pollen spectra at the localities studied represent differences between these localities rather than general changes through time. The environment during the Roman period does not seem to differ significantly from preceding and succeding periods; however, the Romans may have introduced the cultivation of olives in the area.     

内蒙古辉河水坝细石器遗址1996年发掘简报

辉河水坝细石器遗址于1975年在内蒙古呼伦贝尔草原发现,并于1996年进行第一次正式发掘。新石器时代文化层距今8555~4000年,本文主要对此次发掘所获的2654件石制品进行报告与初步研究。通过级差动态分类发现,这批石制品中的制作类型比例较高,石片、细石叶和副产品的数量较大,但未发现石制品原料或毛坯,表明工匠可能在原料产地先进行初步整形,将预制毛坯带回营地,进而加工成器。石制品组合有石片石核、细石核、石核修理石片、剥片程度不同的石片和细石叶、副产品、成形工具以及破损品等,反映出人类行为涵盖了操作序列的生产、使用和废弃三个阶段。细石核预制技术稳定娴熟,普遍存在台面预制和修理现象。出土工具体型较小,精致程度较高,以石镞、端刮器、石刀、细石叶工具等为典型,表明狩猎和加工动物性材料是该工具的主要作用任务。根据推测,遗址内存在分区活动和协调作业的现象,可能是当地史前人类的一处使用时间较长的营地。     

甘肃白龙江流域鸡皮衣属地衣的研究

<正> 1 INTRODUCTION Bailong River, a tributary of Jialing River belonging to the Yangtse River system, is located in the southern part of Gansu Province and the northeast rimland of Qinghai-Tibet Plateau, with total length of over 600km and drainage area of about 31,800km~2. Originating from Dagcanglhamo, Luqu     

Deciduous dental microwear of prehistoric juveniles from the lower Illinois River valley

Scanning electron microscopy was used to study age-related changes in the dental microwear of 36 prehistoric juveniles ranging from 6 to 27 months of age. Juveniles from horticultural (Middle Woodland) and agricultural (Mississippian) groups were studied to allow an investigation of the impact of diet on deciduous microwear. Inclusion of both molars and incisors in the sample permitted identification of age at earliest appearance of wear and comparisons between the age-related microwear characterizing different tooth types. Data on feature frequency and enamel surface characteristics were analyzed. Microwear feature frequencies generally increase with age and/or exposure to wear. Enamel surface characteristics show consistent qualitative changes associated with both age and exposure to wear. Molars and incisors differ for such surface characteristics in a way that make biomechanical sense, given the relative bite forces characterizing these teeth. Dietary reconstruction based on deciduous microwear is complex because of the effects of both age and exposure to wear on feature frequencies and enamel surface characteristics. Nonetheless, the present analyses suggest that 1) diets differed for younger and older juveniles within each cultural group and 2) the Middle Woodland juvenile diet was both harder and more varied in physical consistency than the Mississippian juvenile diet.     

Plant genome databases: from references to inference tools

Plant genome databases play an important role in the archiving and dissemination of data arising from the international genome projects. Recent developments in bioinformatics, such as new software tools, programming languages and standards, have produced better access across the Internet to the data held within them.An increasing emphasis is placed on data analysis and indeed many resources now provide tools allied to the databases, to aid in the analysis and interpretation of the data. However, a considerable wealth of information lies untapped by considering the databases as single entities and will only be exploited by linking them with a wide range of data sources. Data from research programs such as comparative mapping and germplasm studies may be used as tools, to gain additional knowledge but without additional experimentation. To date, the current plant genome databases are not yet linked comprehensively with each other or with these additional resources, although they are clearly moving toward this. Here, the current wealth of public plant genome databases is reviewed, together with an overview of initiatives underway to bind them to form a single plant genome infrastructure.     

Fungal transposons: from mobile elements towards molecular tools

Over the last few years an increasing number of transposons has been identified and characterized in filamentous fungi. This includes members of all known eukaryotic classes of transposable elements. Most interestingly, transposons have also been identified in fungi that are used in biotechnology which could provide new tools for strain improvement or gene tagging. Transposons have already been used for diagnostic and population analysis of fungal strains. The first attempts towards transposon-aided gene tagging have been promising and future efforts will almost certainly add a new and powerful method for gene identification in filamentous fungi. Received: 12 February 1999 / Revision received: 8 April 1999 / Accepted: 9 April 1999     

Soil transfers from valley oak (Quercus lobata Nee) stands increase ectomycorrhizal diversity and alter root and shoot growth on valley oak seedlings

 Soils from valley oak (Quercus lobata Nee) riparian areas of the Cosumnes River Nature Conservancy Preserve near Sacramento, California were added to growth medium of valley oak seedlings grown in a greenhouse or in agricultural fields at Cosumnes which probably once supported valley oak trees and are now replanted with native riparian vegetation or allowed to revegetate naturally. Agricultural field soil from the Cosumnes River Preserve was presumed to be low or lacking in ectomycorrhizal inoculum. The study was designed to (1) determine whether valley oak stand soil transfer could cause mycorrhizal infection on valley oak seedlings in an agricultural field and in a greenhouse, (2) describe ectomycorrhizal morphological types formed on valley oak seedlings, and (3) determine whether seedling growth is enhanced more by transfer of natural valley oak stand soil than agricultural field soil. In the field study, transfer of forest soil increased average ectomycorrhizal diversity (2.4 types) more than transfer of agricultural field soil (1.2 types). Valley oak seedlings were responsive to ectomycorrhizal infection in the field study. With increase in mycorrhizal infection there was an increase in shoot growth at the expense of root growth. In the greenhouse study, both percent mycorrhizal infection and mycorrhizal diversity were increased more by transfer of oak forest and woodland soils than agricultural field soil. Eight morphotypes occurred on seedlings in forest and woodland soils but only three morphotypes in agricultural soil. This result strongly suggests that the agricultural field also harbors ectomycorrhizal propagules but forest and woodland soils support a more abundant and diverse ectomycorrhizal flora. Accepted: 17 August 1997