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1.
The persistent vegetative state (PVS) is one of the most iconic and misunderstood phrases in clinical neuroscience. Coined as a diagnostic category by Scottish neurosurgeon Bryan Jennett and American neurologist Fred Plum in 1972, the phrase “vegetative” first appeared in Aristotle’s treatise On the Soul (circa mid-fourth century BCE). Aristotle influenced neuroscientists of the nineteenth and early-twentieth centuries, Xavier Bichat and Walter Timme, and informed their conceptions of the vegetative nervous system. Plum credits Bichat and Timme in his use of the phrase, thus putting the ancient and modern in dialogue. In addition to exploring Aristotle’s definition of the “vegetative” in the original Greek, we put Aristotle in conversation with his contemporaries—Plato and the Hippocratics—to better apprehend theories of mind and consciousness in antiquity. Utilizing the discipline of reception studies in classics scholarship, we demonstrate the importance of etymology and historical origin when considering modern medical nosology.  相似文献   

2.
The biased way in which some inferences may be drawn from archaeobotanical assemblages, due to problems in identification, is briefly discussed. A potentially important class of plant remains, vegetative parenchymous organs, commonly sources of food, are indicated as being such a class rarely identified from archaeological contexts. Their identification based on characters of the plants' anatomy and morphology together with an understanding of the way in which tissues degrade on preservation by charring is suggested. Characters of the charred tissues that make up vegetative parenchymous organs are described in detail. The processes of sorting and identification are then briefly discussed.  相似文献   

3.
Vegetation stress or mortality can be the result of many factors including drought‐induced water deficit, insect infestations and failures of, or fluctuations in, precipitation sources typical to an area. Reduction of cover and reduced health are identifiable in remotely‐sensed multispectral satellite images. A suite of images from NASA's MODIS sensor was used to calculate the Normalised Difference Vegetation Index (NDVI) during the 2000–2006 North American growing seasons. Fluctuations in NDVI over this period show a significant decline in vegetative health in the region with specific areas showing changes linked to moisture sources, prevailing wind patterns, slope aspect and solar radiation receipt. Ground‐truthing of these areas has confirmed the extent and magnitude of the dieoff signal. Historically, dieoff has been reversed through regeneration as climate conditions return to a normal regime. However, quantification of recent vegetative change in western North America suggests that the degree of change may be too severe for regrowth to occur and may have far‐reaching impacts on a scale unseen in modern times. The loss of vegetative habitat and native species in semi‐arid regions and lack of regeneration in these marginal ecosystems due to prolonged drought are growing global problems. Similar drought stress impacts on marginal ecotypes have also been observed in semi‐arid regions of Australia, South America, Asia and Africa. Observations of the spatial pattern of temperate forest vegetation globally can be used to develop a precise picture of vegetative health in these regions and how they are reacting to global climate change.  相似文献   

4.
This paper investigates spatial associations between environmental change and violence in Darfur. Long-term variations in the geographical distribution of water and vegetative resources can foster migration from areas with decreasing levels of resource availability to areas with increasing levels. Rising ethnic diversity and resource competition can, in turn, escalate the risk of violence in areas of high in-migration. This paper employs a multimethod approach to investigate this hypothesis. Qualitative evidence is used to demonstrate the plausibility of the argument for the case of Darfur. The quantitative analysis is based on information retrieved from satellite imagery on long-term vegetation change and the spatial distribution of attacks on villages in the early phase of the civil war (2003–2005). The findings indicate that violence has been more likely and intense in areas that experienced increasing availability of water and vegetative resources during the 20 years prior to the civil war.  相似文献   

5.
The authors demonstrate that place names can help to reconstruct the changing geography of Moscow by identifying and localizing the stages of the city's growth, the development of its radial-circular layout, the absorption of adjoining villages, the distribution of handicrafts and industries, and the existence of hydrographic features and vegetative cover. (The translation was prepared by James R. Gibson of York University, Toronto.)  相似文献   

6.
The classification of roots and tubers into morphological categories is often confusing and more of a hindrance than a help to archaeobotanical analysis. As such, a new classification, based on the potential for vegetative propagation, is suggested, and the terms it uses are briefly defined. The different categories of roots and tubers are then discussed with reference to the archaeological record and the origins of agriculture in Southwest Asia and Europe.  相似文献   

7.
This paper outlines the methods and results of a study to assess the degree of difficulty imposed by the landscape on livestock mustering in Northern Australia. This was undertaken as part of a larger collaborative study between officers of the then Bureau of Animal Health, the Bureau of Agricultural Economics and CSIRO to ascertain likely costs and benefits of the Brucellosis and Tuberculosis Eradication campaign in Northern Australia. A sample of 1806 grid cells was used to describe and analyse the landscape of the study area. Data for each of the landscape components (landform, lithology, vegetative cover and water features) were evaluated for the degree of difficulty they imposed on livestock mustering and the results analysed. The results are reported by states and study area.  相似文献   

8.
杨永春 《人文地理》2003,18(4):42-47
本文主要根据社会调查结果资料分析了甘肃省河西地区石羊河流域下游民勤县的环境变化趋势及其成因,认为中国西部干旱区各流域下游几乎都存在环境恶化趋势。20世纪50年代以来,该地区地下水位迅速下降,沙漠化、土壤盐渍化、植被衰退过程加快,农业生产受到很大影响。造成环境变化的人文原因主要是全流域人口增长过快所引致的耕地扩张所造成的农业用水需求无节制的增长,导致中上游截留下游淡水资源,使得下游地下水利用规模逐年扩张引致地下水位快速下降和水质迅速恶化。后者又导致盐渍化过程加剧以及农业产量的急剧下降。农业产量下降又成为盲目开垦荒地的主导因素之一。这些都导致了植被衰退和破坏,共同造成了生态环境的灾难性突变。  相似文献   

9.
10.
Abstract

Antikythera is a small, relatively remote Mediterranean island, lying 35 km north-west of Crete, and its few contemporary inhabitants live mainly in the small village at the only port. However, an extensive network of terraces across the island bears witness to the past importance of farming on the island, although the intensity of use of these cultivated plots has changed according to fluctuating population levels. Most recently, the rural population and intensity of cultivation have dramatically declined. Our aim is to understand the recolonisation process of agricultural land by plants after terraces are no longer used for the cultivation of crops. The results demonstrate a relatively quick pace of vegetative recolonisation, with abandoned farm land covered by dense scrub within 20 to 60 years. The archaeological implications are that, following even relatively short periods of abandonment, the landscape would have required arduous reinvestment in the removal of scrub growth, as well as the repair and construction of stone terraces, to allow cultivation once again.  相似文献   

11.
The olive tree (Olea europaea) was domesticated by vegetative propagation of selected wild individuals with superior fruit. Later, new cultivars were established repeatedly from feral trees or from crosses between wild, feral, and domesticated trees. Thus the genetic background of many contemporary domesticated lines is a mixture of ancient cultivars and local wild trees. Ancient DNA may illuminate the complicated process of olive domestication because such DNA sequences provide data about ancient genomes that existed closer to the domestication events. Well preserved DNA must be available for such studies, even though in the Mediterranean region, where olive cultivation took place, the climatic conditions are not favorable for DNA preservation. To select for well preserved pits we measured their proportions of lignin by IR spectroscopy, and correlated this with parameters of DNA quality such as template length in an olive-specific repeat array, and template quantity as determined by real-time PCR amplification. Archaeological pits that passed these tests did contain high quality ancient DNA. We present the first ancient olive DNA sequences and compare them to modern wild, feral and domesticated lines.  相似文献   

12.
A new heterosporous fern species, Azolla boliviensis sp. nov., is described from latest Maastrichtian (latest Cretaceous) to Paleocene (earliest Palaeogene) terrestrial sediments of the Eslabón and Flora Formations, Subandean belt, Bolivia. The species is represented by dissociated but abundantly co-preserved megasporocarps, megaspores, microsporangia, massulae and microspores. The genus consistently characterizes warm-climate lacustrine settings. Fossil Azolla is first identified around the Early to mid-Cretaceous but the genus apparently underwent dramatic radiation during the Late Cretaceous. Abundant Azolla remains in Bolivia add to this portrait of rapid geographie dispersai and diversification near the close of the Cretaceous. The ranges of many Azolla species span the Cretaceous- Palaeogene boundary and the potential of Azolla to withstand altered environmental conditions, such as periodic frost damage, drought, and salinity change, and its ability to undergo rapid vegetative regeneration in association with nitrogen-fixing cyanobacterial symbionts, suggest that the survival of this group was favoured during the adverse conditions of the end-Cretaceous event.  相似文献   

13.
Charcoal recovered from different archaeological excavations carried out in the Teotihuacan Valley, México was used to evaluate whether significant changes in the use of wood took place through time (approx. 400 B.C.–A.D. 1500). Sixteen taxa of trees and shrubs characteristic of the Basin of Mexico were identified (including Pinus, Quercus, Arbutus, Cupressaceae, Alnus, Prunus, Taxodium, Salix, Baccharis and Buddleia, among others). Variations in the proportions of taxa are interpreted as a reflection of the intensity of use rather than an indicator of deforestation. The analysis of the data shows a pattern of continuity in the utilization of taxa throughout the occupation. This includes the use of different vegetative parts (trunk and branches), genera and species with different life forms (trees, shrubs, herbaceous plants) and primary (Pinus and Quercus) as well as secondary taxa (Prunus and Arbutus). We propose that the inhabitants of the Teotihuacan Valley implemented practices to manage vegetation in order to assure resource availability in the region.  相似文献   

14.
The genus Umkomasia, a megasporophyll, belonging to the pteridosperms (seed ferns) in the family Umkomasiaceae (Corystospermaceae), is reassessed comprehensively worldwide. All previous records are analysed. Certain fertile structures previously attributed are reclassified. Umkomasia is shown to be restricted to the Triassic of Gondwana where it is associated with the genus Pteruchus, a microsporophyll, and the genus Dicroidium, a vegetative leaf. It is well represented from Argentina, Australia and southern Africa where the Molteno Formation is by far the most comprehensively sampled with eight species described. Two specimens from the upper Permian of India attributed to Umkomasia are reclassified as cf. Arberiopsis sp. A whorled fertile structure from Antarctica, previously assigned to Umkomasia, is reclassified in a new genus as Axsmithia uniramia. Another compression fossil and the permineralized Umkomasia resinosa remain as valid records from Antarctica. The material described as Umkomasia from the Triassic of China is reclassified as Stenorachis asiatica. The Lower Jurassic record from Germany is placed in a new genus as Kirchmuellia franconica. The records of Umkomasia sp. from the Rhaetic of Germany are reclassified as cf. Kirchmuellia sp. and the single specimen from the Jurassic of Libya as genus et sp. indet. The Lower Cretaceous record from Mongolia has been reclassified by other researchers as Doylea mongolica. A pictorial key to Umkomasia species is provided, geographic and stratigraphic distributions are tabulated.  相似文献   

15.
Pole. M. S., & Raine. J. I., 1994:03:28. Triassic plant fossils from Pollock Road, Southland. New Zealand. Alcheringa 18, 147–159. ISSN 0311-5518.

Sedimentary rocks of the Murihiku Supergroup considered to be latest Triassic (Rhaetian), crop out about 10 m below the Glenham Porphyry, near Glenham, New Zealand. They contain the vegetative macrofossils Marchantites sp. (Hepaticae), Pachydermophyllum praecordillerae (Frenguelli) Retallack and Pachydermophyllum benmorensis Anderson & Anderson (Peltaspermaceae), cf. Dicroidium dubium var. dubium Anderson & Anderson (Corystospermaceae), Desmiophyllum sp. cf. D. indicum Sahni (possible conifer), and Gingkophytopsis sp. (possible progymnosperm).

Reproductive material includes ovulate structures (Peltaspermum cournanei sp. nov.), pollenbearing structures (Antevsia sp.) and probably seeds of the Peltaspermaceae, ? Umkomasia (Corystospermaceae), and a possible progymnosperm microsporophyll.

The palynoflora is dominated by bisaccate gymnospermous pollen, mainly Alisporites spp., consistent with the presence of corystosperm macrofossils. Moderately common pollen of Cycadopites spp. may be of peltasperm origin.  相似文献   

16.
Du, W., Wang, X.L., Komiya, T., Zhao, R. & Wang, Y., April 2016. Dendroid multicellular thallophytes preserved in a Neoproterozoic black phosphorite in southern China. Alcheringa 40, xxx–xxx. ISSN 0311-5518.

A new form of dendroid multicellular thallophyte is documented in the Ediacaran Doushantuo phosphorite at Weng’an, Guizhou Province, southern China. The dendroid thallophytes have variable forms, possibly owing to heteromorphic variation. Many lateral branches extend from the upper portions of the main axes; the lateral branches bear terminal vegetative vesicles, reproductive vesicles, monosporangium-like discoidal vesicles and urn-shaped pseudoparenchymatous structures. The vegetative vesicles give rise to clavate pseudoparenchymatous structures, characterized by differentiation of the thallus medulla/cortex, which might represent an early stage of thallus development. An oogamous conceptacle arising from one carpogonial vesicle forms a highly specialized goblet-shaped conceptacle. The discovery of the new dendroid multicellular thallophytes provides not only the first fossil-based evidence of the morphological complexity and tissue differentiation in the Precambrian organisms but also insights into the life cycle of the Precambrian red algae.

Wei Du* [], School of Earth Sciences and Resources, China University of Geosciences, Beijing, PR China; Xun Lian Wang [], School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China; Tsuyoshi Komiya [], Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan. Ran Zhao [], Department of Earth and Planetary Science, University of Tokyo, Tokyo 113-0033, Japan. Yue Wang [], School of Resources and Environments, Guizhou University, Guiyang, 550025, PR China. *Also affiliated with Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.  相似文献   


17.
Sphenophytes are a common floral element in the Triassic of Gondwana. Most sphenophyte compression fossils have been conventionally assigned to a few, presumably very widespread species of Neocalamites based on vegetative features of the stems (or pith casts) and the foliage. During recent decades, however, new reports on morphological and anatomical details of some of these fossils have cast doubt on the systematic affinities of many Gondwanan Triassic sphenophytes. Here we describe Neocalamites suberosus (Artabe & Zamuner) nov. comb. et emend. and Schizoneura africana Feistmantel emend. from several Triassic deposits in the central Transantarctic Mountains and Victoria Land, East Antarctica. The material enables a critical reevaluation of morphological and anatomical features that have been historically used to define the two genera, including leaf-base morphology, degree of leaf fusion, stem vasculature and vallecular canals, and features of the nodal diaphragm. The diagnoses of Neocalamites and Schizoneura are emended so that they more accurately reflect recent advances in our understanding of the anatomy and ontogeny of these plants.

[Benjamin Bomfleur [bbomfleur@ku]edu], Rudolph Serbet [serbet@ku.edu], Edith L. Taylor [etaylor@ku.edu] and Thomas N. Taylor [tntaylor@ku.edu], Department of Ecology and Evolutionary Biology, and Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA; Ignacio H. Escapa [iescapa@mef.org.ar], CONICET—Museo Paleontológico Egidio Feruglio, Trelew, Chubut 9100, Argentina. Received 4.7.2012; revised 22.12.2012; accepted 7.1.2013.

Bomfleur, B., Escapa, I.H., Serbet, R., Taylor, E.L. & Taylor, T.N., 2013. A reappraisal of Neocalamites and Schizoneura (fossil Equisetales) based on material from the Triassic of East Antarctica. Alcheringa 37, 1–17. ISSN 0311-5518.  相似文献   

18.
19.
McLoughlin, S. & Prevec, R. 20 September 2019. The architecture of Permian glossopterid ovuliferous reproductive organs. Alcheringa XX, xxx–xxx. ISSN 0311-5518

A historical account of research on glossopterid ovuliferous reproductive structures reveals starkly contrasting interpretations of their architecture and homologies from the earliest investigations. The diversity of interpretations has led to the establishment of a multitude of genera for these fossil organs, many of the taxa being synonymous. We identify a need for taxonomic revision of these genera to clearly demarcate taxa before they can be used effectively as palaeobiogeographic or biostratigraphic indices. Our assessment of fructification features based on extensive studies of adpression and permineralized fossils reveals that many of the character states for glossopterids used in previous phylogenetic analyses are erroneous. We interpret glossopterid fertiligers to have been borne in loose strobili in which individual polysperms represent fertile cladodes of diverse morphologies subtended by a vegetative leaf or bract. Polysperms within the group are variously branched or condensed with ovule placement ranging from marginal to abaxial, in some cases occurring on recurved branchlets or in cupule-like structures. Glossopterid polysperms of all types are fringed by one or two ranks of wing-like structures that may represent the remnants of megasporophylls that were, ancestrally, developed on the fertile axillary shoot. Glossopterid fertiligers have similarities to the condensed bract/ovuliferous scale complexes of conifer cones, but comparisons with Mesozoic seed-ferns are hindered by insufficient data on the arrangement and homologies of the ovule-bearing organs of the latter group. Nevertheless, glossopterid polysperms differ from the ovuliferous organs of Mesozoic seed-ferns by longitudinal versus transverse folding, respectively.

Stephen McLoughlin* [], Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, 104 05 Stockholm, Sweden; Rose Prevec [], Department of Earth Sciences, Albany Museum, 40 Somerset Street, Makhanda, 6139, Eastern Cape, South Africa, and Department of Botany, Rhodes University, PO Box 94, Makhanda, 6140, Eastern Cape, South Africa.  相似文献   

20.
《Anthropology today》2019,35(2):i-ii
Front and back cover caption, volume 35 issue 2 Front cover You overlook them every day — sentient vegetative life forms in the cracks and crevices of urban worlds. Perhaps on a spring day you passingly notice ‘trees’ or ‘flowers’ as they bloom, but see nothing of their specificity, their agency, their sociality. Yet plants provide a basis for how we think — ‘roots’ and ‘branches’ structure our language and computational forms; as our thoughts ramify, they ‘sprout’ ideas that ‘stem’ in various directions. And they are the foundation upon which mammals have thrived on earth, so far. You should know more about them than you do. Stop for a moment now and give them your attention. Consider: indigenous communities, whose medicinal plants and knowledge circulate in global marketplaces; roots' and the capacity of roots and seeds to remake, regrow and re-establish themselves in new contexts; or the roles, statuses, channels, spatial-temporal scales and ontological frames required for engaging a plant's point of view. Ponder: taking position alongside botanists and indigenous sages to remake ethnobotanical knowledge; seed conservation as a generative experimental space from which new forms of human-plant relations might flourish; or how communicative phytochemicals differ from the signs and symbols anthropologists typically study. In this special issue we will learn how it is that we think with and through plants. Svalbard Global Seed Vault ( http://www.seedvault.no ) in Longyearbyen, February 2008. The vault provides a safe backup of seeds from food crops conserved by seed banks worldwide. This picture is from the day of the official opening. The entrance to the vault is well guarded from visiting polar bears. During the opening, the vault was guarded by an armed guard and an ice sculpture of a polar bear. Back cover ETHNOGRAPHY OF PLANTS Plants congregate and socialize, and they have long formed part of our publics. They are more than representations in human knowledge systems or world views. But knowing them is difficult and sometimes takes a lifetime. Ethnographers have long gathered and mulled over plant lore, often while partaking of them in various herbal or culinary renderings. This special issue on plant ethnography marks a shift in this contemplative listening stance, by bending closer, leaning over and studying their ways. The questions posed here are important: how do we address them? Can they thrive in the wake of habitat destruction? What can we learn from them before it's too late? Botanists identify and assess rare plant species in the Sonoran Desert in southern California in order to plan the collection of their seeds for long-term seed conservation at the Rancho Santa Ana Botanical Garden, a partner of the global Millennium Seed Bank Partnership (MSBP). The Sonoran Desert has more plant diversity than any other desert in the world, with over 2,000 native plant species which have developed fine balances and beautiful adaptations to life there. These species, however, are caught between two key pressures of the Anthropocene: the prospect of a changing climate, and the encroachment on their habitat by human development, in this case — ironically — by the earmarking of vast areas of the desert as prospective solar energy facility sites. MSBP partners, like Rancho Santa Ana BG, have conserved 13 per cent of the world's wild plant species. The banking of plant seeds insures against their extinction and provides resources for research and reintroduction which can support their conservation, but ultimately, the deserts cannot be conserved through seeds in freezers alone.  相似文献   

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