45 research outputs found
Neonatale early onset Infektion bei maternaler B-Streptokokken-Besiedlung in der Schwangerschaft: Analyse geburtshilflicher Risikofaktoren zur Vermeidung der EOD
In einem Risikokollektiv GBS-kolonisierter Schwangerer sollen das Auftreten einer neonatalen EOD und der Einfluss anamnestischer sowie geburtshilflicher Faktoren retrospektiv analysiert werden. In den Jahren 2005 - 2007 ohne etabliertes Screening betrug die detektierte GBS-Besiedlungsrate 4,2 %. Bei 11,2 % der Neugeborenen wurde die klinische Diagnose einer EOD gestellt. Die Frühgeburtlichkeit und das Geburtsgewicht waren Hauptrisikofaktoren für die neonatale Infektion. Die Optimierung des perinatologischen Managements mit konsekutiver Vermeidung von Frühgeburtlichkeit und Risikoreduktion der neonatalen Infektion hat oberste Priorität
Neonatale early onset Infektion bei maternaler B-Streptokokken-Besiedlung in der Schwangerschaft: Analyse geburtshilflicher Risikofaktoren zur Vermeidung der EOD
In einem Risikokollektiv GBS-kolonisierter Schwangerer sollen das Auftreten einer neonatalen EOD und der Einfluss anamnestischer sowie geburtshilflicher Faktoren retrospektiv analysiert werden. In den Jahren 2005 - 2007 ohne etabliertes Screening betrug die detektierte GBS-Besiedlungsrate 4,2 %. Bei 11,2 % der Neugeborenen wurde die klinische Diagnose einer EOD gestellt. Die Frühgeburtlichkeit und das Geburtsgewicht waren Hauptrisikofaktoren für die neonatale Infektion. Die Optimierung des perinatologischen Managements mit konsekutiver Vermeidung von Frühgeburtlichkeit und Risikoreduktion der neonatalen Infektion hat oberste Priorität
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath
Landslide hazard motivates the need for a deeper understanding of the events that occur before, during, and after catastrophic slope failures. Due to the destructive nature of such events, in situ observation is often difficult or impossible. Here, we use data from a network of 58 seismic stations to characterise a large landslide at the Askja caldera, Iceland, on 21 July 2014. High data quality and extensive network coverage allow us to analyse both long- and short-period signals associated with the landslide, and thereby obtain information about its triggering, initiation, timing, and propagation. At long periods, a landslide force history inversion shows that the Askja landslide was a single, large event starting at the SE corner of the caldera lake at 23:24:05 UTC and propagating to the NW in the following 2 min. The bulk sliding mass was 7–16 × 1010 kg, equivalent to a collapsed volume of 35–80 × 106 m3. The sliding mass was displaced downslope by 1260 ± 250 m. At short periods, a seismic tremor was observed for 30 min before the landslide. The tremor is approximately harmonic with a fundamental frequency of 2.3 Hz and shows time-dependent changes of its frequency content. We attribute the seismic tremor to stick-slip motion along the landslide failure plane. Accelerating motion leading up to the catastrophic slope failure culminated in an aseismic quiescent period for 2 min before the landslide. We propose that precursory seismic signals may be useful in landslide early-warning systems. The 8 h after the main landslide failure are characterised by smaller slope failures originating from the destabilised caldera wall decaying in frequency and magnitude. We introduce the term "afterslides" for this subsequent, declining slope activity after a large landslide
The Relationship Between Lava Fountaining and Vent Morphology for the 2014–2015 Holuhraun Eruption, Iceland, Analyzed by Video Monitoring and Topographic Mapping
Fissure eruptions are associated with lava fountains which often show complex distinct venting activity in pulsating form, and the development of characteristic morphological features such as scoria or spatter cones. Most morphological studies are based on observations of old structures and are not related to direct observations and systematic records of vent activity. The 2014–2015 Holuhraun eruption site, Iceland, offered an exceptional opportunity to study the location and evolution of these cones and their relationship to venting dynamics in unprecedented detail. Here we analyze records from lava fountain activity at distinguished vents, captured during the 2014–2015 Holuhraun eruption, and compare them with the morphology of spatter cones that developed. We conducted a fieldwork mapping project combining terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV) aerophoto techniques to characterize the cone morphologies. We recorded videos of the eruption and used edge detection and particle image velocimetry to estimate venting heights and particle velocities. We find that the number of active vents producing lava fountains decreases from 57 along the whole line of fire to 10 lava fountains at distinct vents during the first 5 days of the eruption. We suggest that this happens by channeling the magma supply in the subsurface developing conduits. Thereby we see that at the locations where spatter cone morphology developed, the strongest and the highest lava fountains with high ejection velocities were recorded on the very first days of the eruption. In addition, the sites that eventually developed moderate or weak cone morphologies were identified as less active lava fountain locations during the early stage of the eruption. The comparison of our topographic datasets shows that the spatter cones remained similar in shape but increased in size as the eruption progressed. In addition, we suggest that the observed changes in morphology may have affected lava ponding in the crater, which in turn strongly influenced the lava fountain heights. Our results improve the general understanding of landscape evolution in rift zones and demonstrate the close relationship between cone morphology and lava fountain activity at the onset of an eruption
Magma Emplacement Rates and Porphyry Copper Deposits:Thermal Modeling of the Yerington Batholith, Nevada
The relation between magnetite and silicate fabric in granitoids of the Adamello Batholith
Decrypting magnetic fabrics (AMS, AARM, AIRM) through the analysis of mineral shape fabrics and distribution anisotropy
The fieldwork was supported by the DIPS project (grant no. 240467) and the MIMES project (grant no. 244155) funded by the Norwegian Research Council awarded to O.G. O.P.'s position was funded from Y-TEC.Anisotropy of magnetic susceptibility (AMS) and anisotropy of magnetic remanence (AARM and AIRM) are efficient and versatile techniques to indirectly determine rock fabrics. Yet, deciphering the source of a magnetic fabric remains a crucial and challenging step, notably in the presence of ferrimagnetic phases. Here we use X-ray micro-computed tomography to directly compare mineral shape-preferred orientation and spatial distribution fabrics to AMS, AARM and AIRM fabrics from five hypabyssal trachyandesite samples. Magnetite grains in the trachyandesite are euhedral with a mean aspect ratio of 1.44 (0.24 s.d., long/short axis), and > 50% of the magnetite grains occur in clusters, and they are therefore prone to interact magnetically. Amphibole grains are prolate with magnetite in breakdown rims. We identified three components of the petrofabric that influence the AMS of the analyzed samples: the magnetite and the amphibole shape fabrics and the magnetite spatial distribution. Depending on their relative strength, orientation and shape, these three components interfere either constructively or destructively to produce the AMS fabric. If the three components are coaxial, the result is a relatively strongly anisotropic AMS fabric (P’ = 1.079). If shape fabrics and/or magnetite distribution are non-coaxial, the resulting AMS is weakly anisotropic (P’ = 1.012). This study thus reports quantitative petrofabric data that show the effect of magnetite distribution anisotropy on magnetic fabrics in igneous rocks, which has so far only been predicted by experimental and theoretical models. Our results have first-order implications for the interpretation of petrofabrics using magnetic methods.Publisher PDFPeer reviewe
Diffuse degassing at Longonot volcano, Kenya: Implications for CO 2 flux in continental rifts
Emplacement and deformation of mesozoic Gabbros of the High Atlas (Morocco): paleomagnetism and magnetic fabrics
A paleomagnetic and magnetic fabric study is performed in Upper Jurassic gabbros of the central High Atlas (Morocco). These gabbros were emplaced in the core of preexisting structures developed during the extensional stage and linked to basement faults. These structures were reactivated as anticlines during the Cenozoic compressional inversion. Gabbros from 19 out of the 33 sampled sites show a stable characteristic magnetization, carried by magnetite, which has been interpreted as a primary component. This component shows an important dispersion due to postemplacement tectonic movements. The absence of paleoposition markers in these igneous rocks precludes direct restorations. A novel approach analyzing the orientation of the primary magnetization is used here to restore the magmatic bodies and to understand the deformational history recorded by these rocks. Paleomagnetic vectors are distributed along small circles with horizontal axes, indicating horizontal axis rotations of the gabbro bodies. These rotations are higher when the ratio between shales and gabbros in the core of the anticlines increases. Due to the uncertainties inherent to this work (the igneous bodies recording strong rotations), interpretations must be qualitative. The magnetic fabric is carried by ferromagnetic (s.s.) minerals mimicking the magmatic fabric. Anisotropy of magnetic susceptibility (AMS) axes, using the rotation routine inferred from paleomagnetic results, result in more tightly clustered magnetic lineations, which also become horizontal and are considered in terms of magma flow trend during its emplacement: NW-SE (parallel to the general extensional direction) in the western sector and NE-SW (parallel to the main faults) in the easternmost structures
Die selbstständige(re) Ganztagsschule
Das Thema Ganztagsschule trifft gegenwärtig mit weiteren Diskussionen im bildungspolitischen Bereich zusammen, so etwa mit der Diskussion um größere Entscheidungsspielräume für die Einzelschule (Stichwort selbstständige Schule). Beide Diskurse führen die Autoren auf der Basis einer Längsschnittstudie zur selbstständigen Ganztagsschule, die 2004 in Mecklenburg-Vorpommern begonnen wurde, zusammen. Dabei können sie zeigen, dass - den Urteilen der Schulleitungen zufolge - selbstständig organisierte Ganztagsschulen eine positivere Entwicklung nehmen als Ganztagsschulen ohne erweiterte Eigenverantwortung. So nutzen selbstständige(re) Ganztagsschulen häufiger als nicht-selbstständige Ganztagsschulen das Potenzial einer neuen Rhythmisierung des Schulalltags aus. Darüber hinaus orientieren sie sich in ihrem außerunterrichtlichen Angebot stärker als die nicht-selbstständigen Schulen am Konzept der individuellen Förderung und haben mehr Angebote für leistungsschwache sowie leistungsstarke Schülerinnen und Schüler. In diesem Beitrag zeigen die Autoren somit auf, dass unterschiedliche Reformansätze sich in ihrer Wirkung gegenseitig unterstützen können. (DIPF/Orig.