The 2000 Cartagena protocol on biosafety: legal and political dimensions     

《Global Environmental Change》2000,10(4):313-317

  相似文献   

Permian-Triassic vertebrate footprints from South Africa: Ichnotaxonomy,producers and biostratigraphy through two major faunal crises     

《Gondwana Research》2019

The fossil record of mid to late Permian terrestrial vertebrates in the South African Karoo Basin is regarded as the most abundant and diverse in the world. Despite the extensive research on body fossils, to-date the vertebrate footprint sites have not been subjected to an anatomy-consistent ichnotaxonomic investigation. Here we present a comprehensive ichnotaxonomic revision of Permian-Early Triassic tracksites in the main Karoo Basin of South Africa. Furthermore, a track-trackmaker correlation for all Permian synapsid groups is provided for the first time, based on the analysis of the functional morphology of potential producers. The following ichnotaxa and their proposed trackmakers are recognized: Brontopus giganteus (dinocephalians), cf. Capitosauroides isp. (therocephalians), cf. Dicynodontipus isp. (cynodonts), Dolomitipes accordii (small dicynodonts), Dolomitipes icelsi n. comb. (large dicynodonts), Karoopes gansfonteinensis n. igen. n. isp. (gorgonopsids), Procolophonichnium nopcsai (procolophonids) and Rhynchosauroides isp. (non-archosauriform diapsids). Three different footprint assemblages (FA I–III) are proposed for footprint biostratigraphy: FA I (lower Tapinocephalus AZ), a Guadalupian assemblage dominated by dinocephalian tracks; FA II (topmost Tapinocephalus-Cistecephalus AZ), a latest Guadalupian-Wuchiapingian assemblage dominated by gorgonopsid and dicynodont tracks in association with subordinate therocephalian tracks and FA III (lower Lystrosaurus AZ), an Induan assemblage with dicynodont, cynodont, procolophonid and diapsid tracks. The lower FA II includes the earliest ichnofauna with Lopingian affinity all over the world (topmost Tapinocephalus-Pristerognathus AZ, ~260–259 Ma) and could indicate an early recovery phase after the end-Guadalupian mass extinction, because of the high abundance of large gorgonopsid tracks and absence of dinocephalian tracks. This footprint record may also predate the body fossil record, suggesting an earlier gorgonopsid radiation. FA III represents the earliest and most complete post end-Permian extinction ichnofauna, which includes an early phase of abundant small dicynodont tracks, potentially indicating a stressed post-event community. Nevertheless, this ichnofauna looks very similar to pre-extinction ichnofaunas from Europe, in agreement with the skeletal record at the Daptocephalus-Lystrosaurus AZ transition.  相似文献   

Hunter‐gatherer response to late Holocene climatic variability in northern and central Australia     

Alan N. Williams  Sean Ulm  Ian D. Goodwin  Mike Smith 《第四纪科学杂志》2010,25(6):831-838

Sum probability analysis of 1275 radiometric ages from 608 archaeological sites across northern and central Australia demonstrates a changing archaeological signature that can be closely correlated with climate variability over the last 2 ka. Results reveal a marked increase in archaeological records across northern and central Australia over the last 2 ka, with notable declines in western and northern Australia between ca. AD 700 and 1000 and post‐AD 1500 – two periods broadly coeval with the Medieval Climatic Anomaly and the Little Ice Age as they have been documented in the Asia–Pacific region. Latitudinal and longitudinal analysis of the dataset suggests the increase in archaeological footprint was continent wide, while the declines were greatest from 9 to 20° S, 110 to 135° E and 143 to 150° E. The change in the archaeological data suggests that, combined with an increase in population over the late Holocene, a disruption or reorganisation of pre‐European resource systems occurred across Australia between ca. AD 700 and 1000 and post‐AD 1500. These archaeological responses can be broadly correlated with transitions of the El Niño–Southern Oscillation (ENSO) mean state on a multi‐decadal to centennial timescale. The latter involve a shift towards the La Niña‐like mean state with wetter conditions in the Australian region between AD 700 and 1150. A transition period in ENSO mean state occurred across Australia during AD 1150–1300, with persistent El Niño‐like and drier conditions to ca. AD 1500, and increasing ENSO variability post‐AD 1500 to the present. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Capacity,capability and cross-border challenges associated with marine eradication programmes in Europe: The attempted eradication of an invasive non-native ascidian,Didemnum vexillum in Wales,United Kingdom     

《Marine Policy》2014

Increasing recognition of the threat which invasive non-native species present to ecological and economic assets has led to a recent surge in international, regional and national policies. Within the European Union, a draft EU Regulation on the prevention and management of invasive alien species has been developed. The draft Regulation, published in 2013, recommends the creation of a list of invasive alien species of Union concern, wherein any Member State identifying newly establishing populations of these species must implement rapid eradication measures. The first recording of the invasive non-native ascidian Didemnum vexillum in Britain in 2008 in Wales, and subsequent eradication efforts, presents a timely opportunity to evaluate the United Kingdom׳s existing capability and capacity to undertake a rapid eradication in the marine environment in light of the draft EU Regulation, as well as highlighting some of the cross-border challenges facing the EU. Although the UK is often cited within Europe as having made significant progress in the field of invasion management, the lessons learned from the eradication process in Wales highlight that the UK is inadequately prepared to undertake rapid eradication measures in the marine environment and that the lack of a coordinated approach between nations has significant potential to devalue localised eradication efforts. A number of measures are discussed to enhance future capability both in the UK and the wider European Union including enhanced alerting mechanisms, science-based monitoring programmes to enable early detection, increased commitment of resources and the need for cross-border collaboration.  相似文献   

Multiphase timing of hominin occupations and the paleoenvironment in Luonan Basin, Central China   总被引：4，自引：0，他引：4  

Huayu Lu  Hongyan Zhang  Richard Cosgrove  Jun Zhao  Cunfa Zhao  Ming Wei 《Quaternary Research》2011,76(1):142-147

Thousands of Paleolithic artifacts have been recovered from Paleolithic sites in the Luonan Basin, in the upper South Luohe River of central China. Their discovery suggests that the basin was an important area for hominin settlement during the Pleistocene. However, the initial timing of this occupation and the environmental conditions for this period are still largely unknown. In addition, the sediments are not well dated and most of the artifacts lie on the surface. In an attempt to resolve these issues, a new systemic paleomagnetic analysis was carried out on the loess deposits that contain in situ stone tools. Our detailed loess-paleosol analyses of the stratigraphy of different sites in the basin and Chinese Loess Plateau shows the accumulation of the loess since at least 1.1 million years (Ma) ago. Moreover, recently discovered in situ cores, flakes and retouched stone tools in these deposits show that hominins used this region repeatedly from 0.8-0.7 Ma to 0.4-0.3 and 0.2-0.1 Ma. Pedostratigraphic analyses, magnetic susceptibility and carbon isotope analyses also indicate that these hominins lived in a subtropical to warm-temperate climate with broad-needle-leaf forest vegetation mixed with grasses.  相似文献   

Fossil wood diversity gradient and Far-East Asia palaeoclimatology during the Late Triassic – Cretaceous interval     

Changhwan Oh  Julien Legrand  Kyungsik Kim  Marc Philippe  In SungPaik 《Journal of Asian Earth Sciences》2011,40(3):710-721

Mesozoic fossil floras are distributed over eastern Asia (China, Mongolia, Siberia, Korea and Japan) according to a regular latitudinal pattern. Two floras are usually distinguished, a northern type and a southern type, the distribution of which oscillated during the Mesozoic. In Japan, this regular pattern is disrupted by a sharp inflexion of the boundary between the two floras. Two competing hypotheses have been proposed to explain this disruption. One hypothesis advocates later tectonic motion clouding the original pattern, while the other hypothesis proposes that a warm oceanic current allowed the southern flora to grow much further north in coastal areas. We used fossil wood, a biotic component that has not previously been used, for a palaeobiogeographical study of the region. The observed fossil wood diversity at the generic level does not fit with the hypothesis of a warm oceanic current, unless this hypothesis is modified to include alternating warm northbound and cold southbound oceanic currents. Our results provide new evidence for the palaeoecology of the Mesozoic continental biota in Far-East Asia.  相似文献   

Asteroidal processes recorded by polyphase deformation in a harzburgitic diogenite NWA 5480     

《Journal of Structural Geology》2015

Expectations regarding structural deformation of asteroidal meteorites have typically revolved around impact-induced shock metamorphism or the gravity-driven axial compression of cumulates at the base of magma chambers. Recent structural analyses, however, of several olivine-rich diogenites (harzburgites) reveal solid-state plastic deformation not attributable to either scenario and propose dynamic mantle movements in the parent body, assumed to be Vesta. In this study we examine the microstructures of pyroxene and olivine in the olivine-rich diogenite NWA 5480. Coarse-grained, poikilitic texture, exsolution lamellae and plastic deformation attest to polyphase deformation and a re-heating event, followed by relatively slow cooling. Observations suggest that impact events alone are insufficient to generate and sustain the thermal and deformation conditions required to achieve all of the observed features. The proposed dynamic mantle movements in the Vestan interior may offer a means of heat transport to the system to provide a thermal environment inducive to slow cooling as well as generate the incremental stress fields required for the polyphase plastic deformation observed in the olivine.  相似文献   

Overabundance of piscivorous dinosaurs (Theropoda: Spinosauridae) in the mid-Cretaceous of North Africa: The Algerian dilemma     

《Cretaceous Research》2015

The informally called ‘Continental intercalaire’ is a series of continental and brackish deposits that outcrops in several regions of North Africa. The age of the series is not well-constrained, but its upper part, visible in the ‘Kem Kem beds’ in Morocco and in Bahariya in Egypt, is regarded as early Cenomanian in age. Spinosaurid remains are an important component of this series, but records of this dinosaur are surprisingly rare in Algerian localities of the ‘Continental intercalaire’. Here, we describe a vertebrate assemblage from two localities, Kénadsa and Menaguir, situated in the Guir basin, Western Algeria. The assemblage comprises hybodont sharks, sarcopterygian fishes, ray-finned fishes, turtles, crocodiles and dinosaurs. Among the latter, only teeth of theropods have been recovered and 94% belong to Spinosaurus. The assemblage is taxonomically very similar to the Moroccan and Egyptian assemblages mentioned above. This study: 1) suggests a likely early Cenomanian age for the Guir basin deposits containing the assemblage; 2) provides a new evidence of the homogeneity of the early Cenomanian vertebrate fauna throughout North Africa; and 3) confirms the overabundance of theropod dinosaurs, especially spinosaurs, in the assemblage showing a possible shortcut in the vertebrate food chain. The northern most locality, Menaguir, shows sedimentological and ichnological evidence of marine influences indicating that the palaeoenvironment shows spatial heterogeneities.  相似文献   

Decreasing intensity of the last glacial stadials in low latitude terrestrial East Asia inferred by a new observation of pollen records in central Taiwan     

《Journal of Asian Earth Sciences》2013

The cold intensity of the last glacial stadials corresponding to marine isotope stage (MIS) 5d (or 5b), MIS 4 and MIS 2 in terrestrial East Asia monsoon area is not discussed much due to the paucity of long continuous pollen records. A palynological study of drilling cores from three closely-linked intramontane basins (Toushe, Sun-moon Lake and Yuchi) in central Taiwan provides a history of shifting altitudinal vegetation zones in surrounding mountains during late Quaternary climate changes. By integrating these records, we found that the alpine conifer forest approached its lowest altitude, about 614 m, during the earliest stadial (≒MIS 5d or 5b), and 745 m during the early stadial (≒MIS 4) based on records of Yuchi Basin and Sun-moon Lake. In addition, the pollen records of Toushe Basin and Sun-moon Lake show more temperate conditions for the late stadial (≒MIS 2) than the early stadial (≒MIS 4). This leads to an interpretation of a decreasing intensity of stadials during the last glaciation, which might follow the regional insolation amplitude. Such a decreasing trend in coldness during the last glacial stadials does not exist in the record for the South China Sea which reflects a different sensitivity and response to climatic forcings between terrestrial and marine.  相似文献   

Stereo topographic models of Mercury after three MESSENGER flybys     

Frank Preusker  Jürgen Oberst  James W. Head  Thomas R. Watters  Mark S. Robinson  Maria T. Zuber  Sean C. Solomon 《Planetary and Space Science》2011,59(15):1910-1917

From photogrammetric analysis of stereo images of Mercury obtained during three MESSENGER flybys, we have produced three digital terrain models (DTMs) that have a grid spacing of 1 km and together cover 30% of the planet's surface. The terrain models provide a rich source of information on the morphology of Mercury's surface, including details of tectonic scarp systems as well as impact craters and basins. More than 400 craters larger than 15 km in diameter are included in the models. Additionally, the models provide important test cases for the analysis of stereo image data to be collected during MESSENGER's orbital mission phase. Small lateral offsets and differences in trends between stereo DTMs and laser altimeter profiles may be due to remaining errors in spacecraft position, instrument pointing, or Mercury coordinate knowledge. Such errors should be resolved during the orbital mission phase, when more joint analyses of data and detailed orbit modeling will be possible.  相似文献