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This paper explores the status and value of ecological resources found in the De-militarized Zone (DMZ), an area of land separating North and South Korea, in terms of habitats and species. This approach contrasts with a conventional species-driven approach. There have been few surveys of ecological resources in the DMZ due to land mines and security issues. As such, there appear to be a number of less well known habitats and understudied and data deficient species within the DMZ. This paper seeks to improve knowledge of ecological resources within the DMZ by combining and synthesizing the authors study results with the outcome of surveys of the DMZ conducted by various organizations. The paper also includes ecological mapping results. Conservation value is assessed using priorities identified by a number of Korean and foreign institutions. The conservation value of habitats, particularly of wetlands including peatland, is based on the Ramsar Site criteria, the International Peat Society criteria, and the designation criteria for the UNESCO World Natural Heritage and Biosphere Reserve. As in-depth studies on the functions of DMZ habitats are not available due to the constraints mentioned above, the habitat assessment is inevitably tentative. Species value is based on the IUCNs Red Data Book (1997). This paper seeks to be used as material contributing to the conservation and sustainable use of the DMZ. In particular, this paper aims to aid in the designation of the DMZ as a World Natural Heritage site through the identification and suggestion of key or prime biodiversity areas within the DMZ. This is completed by using a model suggested by English Nature (UK) based on the aforementioned criteria.  相似文献   
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Abstract. 315 isolated semi-natural and natural stands in NW Germany were investigated floristically, 285 stands of ancient woodlands and 30 recent ones. In the study area nearly all semi-natural and natural ancient woodlands are found on mesotrophic or eutrophic sites and can be assigned to the Fagetalia. 54 selected herbaceous and five woody Fagetalia-species have been tested in their association to ancient woodlands. 21 of the 59 selected plant species show a highly significant association to ancient woodlands and seven species show a weak significance. 31 plant species are not significantly correlated with ancient woodland sites, but 25 of them have a low frequency. The result shows that investigations of the historical ecology can help to understand floristic composition of present-day woodlands. Restriction of many woodland species to ancient woodlands, especially rare species, emphasizes the importance of woodlands with a long continuous history for the preservation of endangered species. Irrespective of ecological conditions, the restriction of plant species to ancient woodlands seems to be mainly caused by their low ability to colonize recent woodlands, especially isolated stands. Differences in the association to ancient woodlands between European countries are assumed to be a function of both time and degree of isolation of woodlands, of the dispersal mode of the plant species and of the availability of suitable habitats.  相似文献   
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本文对周原齐家东M24墓主骨骼进行了生物考古学研究,发现其右侧胫、腓骨下端1/5处为截肢后畸形愈合;胫骨生理长缩短约5 cm,足部离断后缺失。结合创伤情况、考古学背景及文献实物资料,该个体生前极有可能遭受了“惩罚性截肢”,即刖刑。商周时期刖刑的致死率极高,施刑工具可能有青铜刀锯、钻头、石块等,除拉切外还伴有砍砸行为。被刖之人康复后需拄杖行走并承担守门之责,社会地位低下、饮食状况不佳且饱受他人歧视,境遇十分悲惨。周原齐家东M24墓主是我国经过系统研究且年代最早的截肢病例,也是目前所见最为疑似刖刑的首例个体,为深入了解西周时期的刑罚体系、医疗水平及社会观念等提供了生动资料。  相似文献   
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Discrete regions of the eukaryotic genome assume a heritable chromatin structure that is refractory to gene expression, referred to as heterochromatin or “silent” chromatin. Constitutively silent chromatin is found in subtelomeric domains in a number of species, ranging from yeast to man. In addition, chromatin-dependent repression of mating type loci occurs in both budding and fission yeasts, to enable sexual reproduction. The silencing of chromatin in budding yeast is characterized by an assembly of Silent Information Regulatory (SIR) proteins—Sir2, Sir3 and Sir4—with unmodified nucleosomes. Silencing requires the lysine deacetylase activity of Sir2, extensive contacts between Sir3 and the nucleosome, as well as interactions among the SIR proteins, to generate the Sir2–3–4 or SIR complex. Results from recent structural and reconstitution studies suggest an updated model for the ordered assembly and organization of SIR-dependent silent chromatin in yeast. Moreover, studies of subtelomeric gene expression reveal the importance of subtelomeric silent chromatin in the regulation of genes other than the silent mating type loci. This review covers recent advances in this field.  相似文献   
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The leopard shark, Triakis semifasciata, is an abundant nearshore elasmobranch, ranging from Baja California, Mexico to Oregon, USA. Mature female leopard sharks have been observed aggregating in shallow embayments throughout California; however, it is unclear why only females aggregate in these shallow areas. The goal of this study was to determine if mature female leopard sharks selectively occupy the warmest areas of a shallow embayment, if free-ranging leopard sharks' body temperatures are significantly warmer during the day than at night, and to quantify temporal use of these shallow habitats. Visual observations of sharks' fine-scale movements within the shallows of Big Fisherman's Cove Marine Life Refuge (Santa Catalina Island) aggregation site indicated that sharks preferred the warmest areas of the embayment and moved to warmer locations over the course of the day (p < 0.05). Active and passive acoustic tracking, along with archival transponder technology (Vemco: V13, V13-R256, VX32TP-CHAT tags respectively) of 16 sharks caught and tagged within this aggregation were used to monitor core body temperature, swimming depth, and movements. Sharks had significantly higher core body temperatures in the late afternoon (1700 h-2000 h) during the summer, showed increased fidelity to thermal refuges during the day and increased movement away from these refuges at night (χ2, p < 0.05). Seasonal variations in warm, shallow water usage were also observed. Elevated core body temperature of mature female leopard sharks using warm shallow embayments will likely augment metabolic and physiological functions such as digestion, somatic growth, and possibly reproduction.  相似文献   
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Zusammenfassung Der Einbau von intracranial sowie intraocular-appliziertem N-acetyl-3H-Mannosamin (N-Ac-3H-Man) in das optische System (Tectum opticum bzw. Tractus opticus) von Scardinius erythrophthalmus und Carassius carassius (cyprinidae, Telosteer) wurde autoradiographisch untersucht und mit dem Einbau von 3H-Histidin verglichen.1. Intracranial appliziertes N-Ac-3H-Man wird im Tectum opticum in Glykoproteine und Ganglioside im Verhältnis von 2:1 eingebaut.2. Die Synthese von Gangliosiden und Sialo-Glycoproteinen erfolgt im Nervengewebe im Gegensatz zu der von Proteinen ubiquitär, d. h. sowohl in den Perikaryen als auch in den Fasern.3. Nach einseitiger intraocularer Applikation von N-Ac-3H-Man werden bereits nach 24 stündiger Inkorporationszeit ausschließlich die mit dem injizierten Auge zusammenhängenden Sehschichten (Stratum opticum) des kontralateralen Tectum opticum radioaktiv markiert. Im Zusammenhang mit ergänzenden biochemischen Analysen ergibt sich, daß die Radioaktivität niedermolekularer Aminozucker mit dem schnellen axonalen Transport (>40 mm/d) zum Zwecke einer peripheren Gangliosid-Synthese im Tractus opticus proximo-distal verlagert wird.
Autoradiographic investigations on the incorporation of N-Acetyl-3H-Mannosamine into the optic system of teleosts
Summary The incorporation of intra-cranially and intra-ocularly injected (N-Ac-3H-Man) and 3H-histidine into the optic systems (optic tectum and optic tract) of Scardinius erythrophthalmus and Carassius carassius was investigated by means of autoradiography.1. N-Ac-3H-Man injected intra-cranially, is incorporated into gangliosides and glycorproteins in a ratio of 1:2 in the optic tectum.2. In nervous tissue gangliosides and sialo-glycoproteins are labeled ubiquitously, i.e. in the perikarya as well as in the fibers.3. Following an intra-ocular injection of N-Ac-3H-Man and after an incorporation period of 24 hrs, only the optic layers in the contralateral optic tectum are labelled (gangliosides). Together with corresponding biochemical data, this shows, that in the optic tract radioactivity of low molecular amino sugars is transported proximo-distally by means of rapid axonal flow (>40 mm/d), before the incorporation into high molecular compounds.
Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft.  相似文献   
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