22 research outputs found

    A Late Pleistocene Wetland Setting in the Arid Jurf ed Darawish Region in Central Jordan

    Get PDF
    Current conditions in the southern Levant are hyperarid, and local communities rely on fossil subsurface water resources. The timing of more favourable wetter periods and also their spatial characteristics are not yet well constrained. To improve our understanding of past climate and environmental conditions in the deserts of the southern Levant, sedimentary sections including artefact-bearing beds from Jurf ed Darawish on the Central Jordanian Plateau were investigated using sedimentological and micropalaeontological analyses and OSL dating. Grain-size analysis and structures of the clayey-silty sediments show that they mainly represent reworked loess deposits. The OSL ages suggest that these fine-grained sediments were accumulated during Marine Isotope Stages (MIS) 5-3. Recorded ostracod valves (mostly Potamocypris, Ilyocypris and Pseudocandona), remains of aquatic and terrestrial gastropod shells, and charophyte gyrogonites and stem encrustations indicate that an in-stream wetland existed at the location of Jurf ed Darawish during MIS 5-4 which was replaced by a vegetated alluvial plain in MIS 3. The prevailing aggradational setting was replaced by an erosional setting sometime after 30 ka. Abundant artefacts, distributed over a vertical range of up to 40 cm in a bed covered by a sedimentary sequence of 12-m thickness, provide evidence for the presence of humans in the region during a relatively long period from ca. 85 to 65 ka. The reconstruction of an in-stream wetland at Jurf ed Darawish, and the presence of humans at the site and in other desert regions of the Jordanian Plateau, the Wadi Arava/Araba, and the Negev and the Nefud deserts, show that the regional climate in the late MIS 5 and MIS 4 was significantly wetter than today and provided favourable conditions for humans in the Southern Levant and the northwestern Arabian Peninsula

    Waldinventur und Klimawandel

    Get PDF
    Experten dreier deutscher Hochschulen entwickelten gemeinsam mit der Ostdeutschen Gesellschaft für Forstplanung mbH ein neues, forstliches Monitoringsystem. Das Verbundprojekt „Entwicklung eines forstlichen Monitoringsystems unter Berücksichtigung von Kohlenstoffspeicherung und Klimaanpassung“ (FOMOSY-KK) wird vorgestellt

    Palaeoenvironmental inferences from late Quaternary sediments of the Al Jafr Basin, Jordan

    No full text
    Sedimentological, palaeontological and mineralogical analyses of sediments from the endorheic Al Jafr Basin were conducted to better understand the depositional and hydrological conditions on the southern Jordan Plateau in the late Quaternary. Surficially exposed carbonate-rich sediments in the western part of the basin contain ostracod (micro-crustacean) shells of Ilyocypris cf. bradyi, Candona neglecta, Heterocypris salina, Fabaeformiscandona fabaeformis, Pseudocandona sp. and Herpetocypris brevicaudata. The shells of these and other more rare species, and charophyte and mollusc remains indicate that the sediments were formed in a wetland setting of shallow freshwater to slightly oligohaline ponds, streams and swamps. The present more northern distribution of some of the recorded taxa implies that climate conditions were probably cooler during the wetland formation. Radiocarbon age data for biogenic carbonate from two locations suggest that the wetland setting existed during the second half of Marine Isotope Stage (MIS) 3 or possibly earlier. A significantly higher water table must have existed in the basin during wetland formation; and wetter climate conditions are inferred for the catchment or at least for its highest and most humid westernmost part. Deflation and local sediment accumulation by wind and occasional sheet-wash events apparently prevailed in the region since MIS 2. Our newly presented data and inferences do not support the reconstruction of a previously reported large and relatively deep Pleistocene lake in the Al Jafr Basin. However, more extensive studies are certainly required for a detailed assessment of the Quaternary hydrological conditions in southern Jordan. (C) 2014 Elsevier Ltd and INQUA. All rights reserved

    Range dynamics of the reindeer in Europe during the last 25,000 years

    No full text
    Aim To understand the role and significance of the reindeer, Rangifer tarandus (Linnaeus, 1758), as a specific indicator in terms of late Quaternary biogeography and to determine the effects of global climate change on its range and local extinction dynamics at the end of the Ice Age. Location Late Pleistocene/early Holocene range of reindeer over all of central and western Europe, including southern Scandinavia and northern Iberia, but excluding Russia, Belarus and the Ukraine. Methods Radiocarbon-dated subfossil records of R. tarandus from both archaeological and natural deposits younger than 25,000 years were assembled in a database. The distribution area was divided into six representative regions. The C-14 dates were calibrated and plotted chronologically in maps in order to compare presence and absence and regional extinction patterns from one region to another. Results After the Last Glacial Maximum, R. tarandus disappeared from southeastern Central Europe but survived in the south-west until the Younger Dryas period. The 'Allerod warming' did not result in complete extirpation of reindeer in Central Europe. Reindeer probably disappeared c. 11,250 years ago in the North European Plain and c. 11,000 years ago in the British Isles. In southern Scandinavia the species survived until c. 10,300 years ago. Main conclusions The late Quaternary record for reindeer in Europe during the last 25 kyr shows a climate-driven dispersal and retreat in response to climate change, with regional variations. The collapse of the mammoth steppe biome did not lead to the local extinction in Europe, as in the case of other megafaunal species. Rangifer tarandus co-existed for about 3000 years during the Late Glacial and early Holocene with typical temperate species such as red deer and roe deer in non-analogue faunal communities. The regional extinction at the end of the Pleistocene coincides with the transition from light open birch/pine forests to pine/deciduous forests

    Waldinventur und Klimawandel

    No full text
    Experten dreier deutscher Hochschulen entwickelten gemeinsam mit der Ostdeutschen Gesellschaft für Forstplanung mbH ein neues, forstliches Monitoringsystem. Das Verbundprojekt „Entwicklung eines forstlichen Monitoringsystems unter Berücksichtigung von Kohlenstoffspeicherung und Klimaanpassung“ (FOMOSY-KK) wird vorgestellt

    Comparing the neural correlates of affective and cognitive theory of mind using fMRI: Involvement of the basal ganglia in affective theory of mind

    Get PDF
    Theory of Mind (ToM) is the ability to infer other people's mental states like intentions or desires. ToM can be differentiated into affective (i.e., recognizing the feelings of another person) and cognitive (i.e., inferring the mental state of the counterpart) subcomponents. Recently, subcortical structures such as the basal ganglia (BG) have also been ascribed to the multifaceted concept ToM and most BG disorders have been reported to elicit ToM deficits. In order to assess both the correlates of affective and cognitive ToM as well as involvement of the basal ganglia, 30 healthy participants underwent event-related fMRI scanning, neuropsychological testing, and filled in questionnaires concerning different aspects of ToM and empathy. Directly contrasting affective (aff) as well as cognitive (cog) ToM to the control (phy) condition, activation was found in classical ToM regions, namely parts of the temporal lobe including the superior temporal sulcus, the supplementary motor area, and parietal structures in the right hemisphere. The contrast aff > phy yielded additional activation in the orbitofrontal cortex on the right and the cingulate cortex, the precentral and inferior frontal gyrus and the cerebellum on the left. The right BG were recruited in this contrast as well. The direct contrast aff > cog showed activation in the temporoparietal junction and the cingulate cortex on the right as well as in the left supplementary motor area. The reverse contrast cog > aff however did not yield any significant clusters. In summary, affective and cognitive ToM partly share neural correlates but can also be differentiated anatomically. Furthermore, the BG are involved in affective ToM and thus their contribution is discussed as possibly providing a motor component of simulation processes, particularly in affective ToM

    Neurotransmitter changes in dementia with Lewy bodies and Parkinson disease dementia in vivo

    No full text
    Although Parkinson disease with dementia (PDD) and dementia with Lewy bodies (DLB) show a wide clinical and neuropathologic overlap, they are differentiated according to the order and latency of cognitive and motor symptom appearance. Whether both are distinct disease entities is an ongoing controversy. Therefore, we directly compared patients with DLB and PDD with multitracer PET.PET with (18)fluorodopa (FDOPA), N-(11)C-methyl-4-piperidyl acetate (MP4A), and (18)fluorodeoxyglucose (FDG) was performed in 8 patients with PDD, 6 patients with DLB, and 9 patients with PD without dementia vs age-matched controls. Data were analyzed with voxel-based statistical parametric mapping and region of interest-based statistics.We found a reduced FDOPA uptake in the striatum and in limbic and associative prefrontal areas in all patient groups. Patients with PDD and patients with DLB showed a severe MP4A and FDG binding reduction in the neocortex with increasing signal diminution from frontal to occipital regions. Significant differences between PDD and DLB were not found in any of the radioligands used. Patients with PD without dementia had a mild cholinergic deficit and no FDG reductions vs controls.Patients with dementia with Lewy bodies and Parkinson disease dementia share the same dopaminergic and cholinergic deficit profile in the brain and seem to represent 2 sides of the same coin in a continuum of Lewy body diseases. Cholinergic deficits seem to be crucial for the development of dementia in addition to motor symptoms. The spatial congruence of cholinergic deficits and energy hypometabolism argues for cortical deafferentation due to the degeneration of projection fibers from the basal forebrain

    Validation of a novel Montreal Cognitive Assessment scoring algorithm in non-demented Parkinson's disease patients

    No full text
    Introduction The early diagnosis of mild cognitive impairment (PD-MCI) in Parkinson's disease (PD) is essential as it increases the future risk for PD dementia (PDD). Recently, a novel weighting algorithm for the Montreal Cognitive Assessment (MoCA) subtests has been reported, to best discriminate between those with and without cognitive impairment in PD. The aim of our study was to validate this scoring algorithm in a large sample of non-demented PD patients, hypothesizing that the weighted MoCA would have a higher diagnostic accuracy for PD-MCI than the original MoCA. Methods In 202 non-demented PD patients, we evaluated cognitive status, clinical and demographic data, as well as the MoCA with a weighted and unweighted score. Receiver operating characteristic (ROC) curve analysis was used to evaluate discriminative ability of the MoCA. Group comparisons and ROC analysis were performed for PD-MCI classifications with a cut-off <= 1, 1.5, and 2 standard deviation (SD) below appropriate norms. Results PD-MCI patients scored lower on the weighted than the original MoCA version (p < 0.001) compared to PD patients with normal cognitive function. Areas under the curve only differed significantly for the 2 SD cut-off, leading to an increased sensitivity of the weighted MoCA score (72.9% vs. 70.5%) and specificity compared to the original version (79.0% vs. 65.4%). Conclusions Our results indicate better discriminant power for the weighted MoCA compared to the original for more advanced stages of PD-MCI (2 SD cut-off). Future studies are needed to evaluate the predictive value of the weighted MoCA for PDD
    corecore