73 research outputs found
ThrombozytÀre Serotoninkonzentration und Serotoninaufnahme bei Kindern und Jugendlichen: Korrelation zu depressivem, agressivem und suizidalem Verhalten
Bei 145 stationĂ€ren Patienten der Kinder- und Jugendpsychiatrie der FSU Jena (4 bis 19 Jahre) wurden die thrombozytĂ€re Serotoninkonzentration, sowie Maximalgeschwindigkeit Vmax und AffinitĂ€tskonstante Km des Serotonintransportes in die Thrombozyten anhand des Thrombozytenmodells bestimmt. Zeitnah wurden bei einem Teil der Patienten die AusprĂ€gung depressiver (DIKJ) und aggressiver (EAS, FAF) Symptome testpsychologisch erhoben sowie Angaben ĂŒber die SuizidalitĂ€t erfasst). Es bestand eine negative Korrelation zwischen thrombozytĂ€rem Serotonin und dem DepressivitĂ€tsgrad. UnabhĂ€ngig von der klinischen Diagnose ergaben sich signifikant niedrigere Serotoninkonzentrationen bei den Kindern und Jugendlichen, die unmittelbar vor der stationĂ€ren Aufnahme einen Suizidversuch unternommen hatten. Hier waren zudem die Aufnahmeparameter Vmax und Km im Trend vermindert. Die vorliegenden Untersuchungen stĂŒtzen die Auffassung, dass DepressivitĂ€t in der Kindheit und Jugend mit einem Mangel an Serotonin im Thrombozyten und möglicherweise in zentralen Strukturen verbunden ist und ein relatives Defizit an Serotonin ein SuizidalitĂ€tsmarker sein könnte. Die serotonergen VerĂ€nderungen erwiesen sich eher als symptomabhĂ€ngig, als dass sie nosologischen, diagnoseorientierten Kriterien folgten
Chromosomale VerÀnderungen oberflÀchlicher Harnblasenkarzinome hinsichtlich ihrer RezidivitÀt und MultifokalitÀt
Harnblasenkarzinome sind die zweithÀufigsten Tumore des Urogenitaltraktes und rezidivieren auch in oberflÀchlichen Stadien hÀufig. Die vorliegende Arbeit untersucht einen möglichen Zusammenhang chromosomaler VerÀnderungen oberflÀchlicher Harnblasenkarzinome pTaG1-2 hinsichtlich deren RezidivhÀufigkeit, der rezidivfreien Zeit und der MultifokalitÀt dieser Tumore. Dazu wurde die Methode der Vergleichenden Genomischen Hybridisierung (CGH- Comparative Genomic Hybridization) angewandt. Es zeigte sich, dass Tumoren mit abnehmender durchschnittlicher rezidivfreier Zeit deutlich mehr Gesamtaberrationen. Tumoren mit einem kurzen Rezidivintervall hatten hÀufiger Verluste am Chromosom 11 sowie Zugewinne an den Chromosomen 1, 11 und 17. Die multifokalen Tumoren bildeten im Gegensatz zu den monofokalen vermehrt Zugewinne am Chromosom 1 sowie Verluste an 8p, 10q und Chromosom 11 aus. Weiterhin zeigten Tumore weiblicher Patienten deutlich mehr Verluste am Chromosom 10 als mÀnnliche Patienten. Somit können chromosomale VerÀnderungen gezeigt werden, welche Hinweise auf den klinischen Verlauf oberflÀchlicher Harnblasenkarzinome geben können
Mississippi River discharge over the last ~560,000years â Indications from X-ray fluorescence core-scanning
The long term history of terrigenous flux to the Gulf of Mexico via the Mississippi River is hardly known. We here present geochemical and sedimentological data to approximate the varying Mississippi River sediment influx into the northeastern Gulf of Mexico (GoM) over the last six glacial-interglacial cycles (MIS 1 to 14). Our study is based on the IMAGES sediment core MD02-2576 that was recovered from the DeSoto Canyon and is located ~ 200 km south to the recent Mississippi River delta and ~ 150 km east of the recent coastline of Florida. Concentrations of siliciclastic elements in bulk sediment samples were estimated from XRF scanning and calibrated by single bulk XRF-analyses. Elemental ratios of the sedimentary record correspond to ratios from the Mississippi River catchment rather than to the core close Alabama and Mobile River catchments. The siliciclastic major element potassium (K) with enhanced surface concentrations in the northwestern Mississippi River catchment shows varying occurrence downcore and here serves as a proxy for Mississippi River sediment discharge variability. Changes in sedimentation rate and magnetic susceptibility further support the variations in Mississippi River influx. Our data were compared with Mississippi River terrestrial archives in the form of loess and terrace deposits that back up our interpretations of enhanced glacial phase Mississippi River influx triggered by strengthened fluvial river runoff and changing fluvial and ice sheet dynamics. Mississippi River influx was at a maximum during glacial MIS 2/3, MIS 8 and MIS 10. Late glacial MIS 6 deviates from this pattern being a period of reduced Mississippi River influx at the core location, probably due to a westward shift of the Mississippi River delta
Mississippi River discharge over the last ~560,000years â Indications from X-ray fluorescence core-scanning
A high-resolution belemnite geochemical analysis of Early Cretaceous (Valanginian-Hauterivian) environmental and climatic perturbations
International audienceThe Early Cretaceous Weissert event, characterized by a positive carbon isotope excursion and coincident with the ParanĂĄ-Etendeka volcanism, saw a biogeochemical chain of events that ultimately led to an increase in carbon burial. A conclusive link between the ParanĂĄ-Etendeka volcanism and its impact upon the environment remains, however, elusive. Here we reconstruct temperature through the Weissert event from Mg/Ca ratios of belemnites from the Vocontian Trough (France) and SE Spain and use carbon isotopes to link our temperature reconstruction to marine records of carbon cycling. We provide evidence that the ParanĂĄ-Etendeka volcanism, unlike some large igneous provinces, did not cause a climate warming. The case can be made for cooling in the last stages of the Weissert event, which possibly reflects substantial CO 2 drawdown. In the absence of warming and consequent accelerated hydrological cycling and the relatively long duration of the eruptive phase of the ParanĂĄ-Etendeka, an alternate trigger for increased fertilization of the oceans is implicated
Carbon cycle history through the JurassicâCretaceous boundary: A new global ÎŽ13C stack
publisher: Elsevier articletitle: Carbon cycle history through the JurassicâCretaceous boundary: A new global ÎŽ13C stack journaltitle: Palaeogeography, Palaeoclimatology, Palaeoecology articlelink: http://dx.doi.org/10.1016/j.palaeo.2016.03.016 content_type: article copyright: Copyright © 2016 Published by Elsevier B.V
Biotic and environmental dynamics through the Late Jurassic-Early Cretaceous transition: evidence for protracted faunal and ecological turnover
The Late Jurassic to Early Cretaceous interval represents a time of environmental upheaval and cataclysmic events, combined with disruptions to terrestrial and marine ecosystems. Historically, the Jurassic/Cretaceous (J/K) boundary was classified as one of eight mass extinctions. However, more recent research has largely overturned this view, revealing a much more complex pattern of biotic and abiotic dynamics than has previously been appreciated. Here, we present a synthesis of our current knowledge of Late JurassicâEarly Cretaceous events, focusing particularly on events closest to the J/K boundary. We find evidence for a combination of short-term catastrophic events, large-scale tectonic processes and environmental perturbations, and major clade interactions that led to a seemingly dramatic faunal and ecological turnover in both the marine and terrestrial realms. This is coupled with a great reduction in global biodiversity which might in part be explained by poor sampling. Very few groups appear to have been entirely resilient to this J/K boundary âeventâ, which hints at a âcascade modelâ of ecosystem changes driving faunal dynamics. Within terrestrial ecosystems, larger, more-specialised organisms, such as saurischian dinosaurs, appear to have suffered the most. Medium-sized tetanuran theropods declined, and were replaced by larger-bodied groups, and basal eusauropods were replaced by neosauropod faunas. The ascent of paravian theropods is emphasised by escalated competition with contemporary pterosaur groups, culminating in the explosive radiation of birds, although the timing of this is obfuscated by biases in sampling. Smaller, more ecologically diverse terrestrial non-archosaurs, such as lissamphibians and mammaliaforms, were comparatively resilient to extinctions, instead documenting the origination of many extant groups around the J/K boundary. In the marine realm, extinctions were focused on low-latitude, shallow marine shelf-dwelling faunas, corresponding to a significant eustatic sea-level fall in the latest Jurassic. More mobile and ecologically plastic marine groups, such as ichthyosaurs, survived the boundary relatively unscathed. High rates of extinction and turnover in other macropredaceous marine groups, including plesiosaurs, are accompanied by the origin of most major lineages of extant sharks. Groups which occupied both marine and terrestrial ecosystems, including crocodylomorphs, document a selective extinction in shallow marine forms, whereas turtles appear to have diversified. These patterns suggest that different extinction selectivity and ecological processes were operating between marine and terrestrial ecosystems, which were ultimately important in determining the fates of many key groups, as well as the origins of many major extant lineages. We identify a series of potential abiotic candidates for driving these patterns, including multiple bolide impacts, several episodes of flood basalt eruptions, dramatic climate change, and major disruptions to oceanic systems. The J/K transition therefore, although not a mass extinction, represents an important transitional period in the co-evolutionary history of life on Earth
The terrigenous Mississippi River discharge into the northeastern Gulf of Mexico over the last ~560.000 years - indications from X-ray fluorescence core-scanning data
Climatic and environmental dynamics during the Valanginian carbon isotope event
Das Valangin (~ 144,5-133,9 Mio., Unterkreide) zeichnet sich durch eine positive Kohlenstoffisotopenexkursion (CIE) aus, die auf eine Störung im Kohlenstoffkreislauf hindeutet. CIEs sind fĂŒr zahlreiche Abschnitte der Kreide bekannt. Im Vergleich zu spĂ€teren CIEs lassen sich fĂŒr das Valangin keine erhöhten Akkumulationen von organischem Material im marinen Raum nachweisen, ĂŒber die Rolle kontinentaler Umwelten ist wenig bekannt. Diese Studie umfasst eine detaillierte Untersuchung von Umwelt- und Klimadynamiken im Valangin, mit einem Fokus auf dem terrestrischen Raum. Marine Sedimente zweier LokalitĂ€ten (Vokontisches Becken, Frankreich; Mittel-Polnischer Trog, Polen) dienen als Archive fĂŒr einen kombinierten Ansatz aus Geochemie, Palynologie, Chemo- und Biostratigraphie. VerĂ€nderungen auf den Kontinenten, insbesondere in FeuchteverhĂ€ltnissen, lassen sich gut mit der CIE korrelieren, ein Hinweis fĂŒr eine kontinentale Kohlenstoffspeicherung als wichtiger auslösender Faktor fĂŒr diese CIE
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