115 research outputs found

    On the ferromagnetic character of (LaVO3_3)m_m/SrVO3_3 superlattices

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    The experimental observation that vanadate superlattices (LaVO3_3)m_m/SrVO3_3 show ferromagnetism up to room temperature [U.\ L\"uders {\it et al.}, Phys.\ Rev.\ B {\bf 80}, 241102R (2009)] is investigated by means of density functional theory. First, the influence of the density functional on the electronic and magnetic structure of bulk LaVO3{\rm LaVO_3} is discussed. Second, the band structure of a (LaVO3_3)m_m/SrVO3_3 slab for m=5m=5 and 6 is calculated. Very different behaviors for odd and even values of mm are found: In the odd case lattice relaxation results into a buckling of the interface VO2_2 layers that leads to spin-polarized interfaces. In the even case a decoupling of the interface VO2_2 layers from the LaO layers is obtained, confining the interface electrons into a two-dimensional electron gas. The orbital reconstruction at the interface due to the lattice relaxation is discussed.Comment: 8 pages, 7 figure

    Private Security Companies and Local Populations : An Exploratory Study of Afghanistan and Angola

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    This paper looks at how local populations perceive Private Security Companies (PSCs) and what the impact of their activities may be on peoples’ every day lives, examining the two country cases, Afghanistan and Angola. The role and effects of PSCs have been discussed from various angles in the past but little attention has been paid to the perspectives of the local population. The goal of this exploratory study is to provide some tentative insights into the perceived positive and negative, direct and indirect impact of PSCs on the local population. One of the central findings from the two cases is the overall negative view of those interviewed towards PSCs. The study suggests that PSCs contribute to a sense of distrust and insecurity. Among the main reasons for this are an overall lack of transparency regarding PSCs, with respect to hiring practices, mandates, identification, accountability, and supervision; the heavy armament of PSCs; and lacking regulation (respectively lacking implementation) of security companies. The paper offers some recommendations, how the concerns of the local population could be better addressed.Das vorliegende Working Paper untersucht anhand der beiden LĂ€nderbeispiele Afghanistan and Angola wie lokale Bevölkerungen private Sicherheitsfirmen (PSCs) wahrnehmen und welchen Einfluss ihre AktivitĂ€ten auf das Alltagsleben der Bevölkerung haben. Die Rolle und die Auswirkungen von PSCs wurden in den letzten Jahren aus verschiedenen Blickwinkeln analysiert, aber bislang wurde der Perspektive der lokalen Bevölkerung nur wenig Beachtung geschenkt. Das Ziel dieser explorativen Studie ist es, einige erste Einblicke in die wahrgenommen positiven und negativen, direkten und indirekten Wirkungen von PSCs auf die lokale Bevölkerung zu erfassen. Eines der Hauptergebnisse der beiden Fallstudien ist, dass PSCs in ĂŒberwiegend negativem Licht betrachtet werden. Die Resultate legen nahe, dass PSCs zu einem GefĂŒhl der Unsicherheit und des Misstrauens beitragen. Die zentralen GrĂŒnde dafĂŒr sind unter anderem die schwere Bewaffnung der PSCs, fehlende Kennzeichnungen sowie die generell mangelhafte Transparenz der PSCs bezĂŒglich ihrer Mandate und bei der Rekrutierung. Weiter werden die fehlende Rechenschaftspflicht und Aufsicht sowie die ungenĂŒgende Regulierung (beziehungsweise deren mangelhafte Umsetzung) von privaten SicherheitskrĂ€ften kritisiert. Die Arbeit entwickelt abschliessend einige Empfehlungen, wie die Bedenken der Bevölkerung besser berĂŒcksichtigt werden können

    The Quaternary of the southwest German Alpine Foreland (Bodensee-Oberschwaben, Baden-WĂŒrttemberg, Southwest Germany)

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    Das QuartĂ€r der Bodensee-Region besteht aus Schottern frĂŒhpleistozĂ€ner alpiner Flusssysteme (Deckenschotter) sowie aus glazialen und Schmelzwasser-Ablagerungen der mittel- und spĂ€tpleistozĂ€nen Eiszeiten. Sie belegen den landschaftlichen Wandel von einer Art Rampe aus Vorbergen hin zur heutigen Topographie mit ineinander greifenden, übertieften Becken, sodass sich eine Art Amphitheater ergibt. Die Deckenschotter als Ă€lteste Ablagerungen dokumentieren einerseits die Eintiefung der alpinen FlĂŒsse in diversen Terrassenstufen im Sedimentationsgebiet, andererseits durch deutliche Unterschiede im Geröllspektrum die VergrĂ¶ĂŸerung des Liefergebiets des sich entwickelnden alpinen Rheins. Der Ă€lteste Till kommt vor in Kontakt mit Mindel-Deckenschottern, es gibt jedoch keine Hinweise auf eine glaziale Übertiefung in dieser Zeit. Die meisten glazialen und Schmelzwasser-Ablagerungen werden drei großen Vergletscherungen des Rheingletschers zugeordnet. Diese Vorlandvergletscherungen sind mit drei Generationen glazialer Becken verknĂŒpft. Die Ă€ltesten Becken sind zur Donau orientiert, die aus der letzten Vereisung entwĂ€ssern zum Rhein. Diese Reorientierung bewirkte die hervorragende rĂ€umliche Auflösung der Sedimente und Formen. Traditionell wurden die Sedimente in einem chronostratigraphischen System aus glazialen und interglazialen Stufen beschrieben. Unsere Ziele in dieser Arbeit sind, eine Aktualisierung des chronostratigraphischen Systems vorzustellen, das neue, beim geologischen Dienst von Baden-Württemberg angewandte, lithostratigraphische Schema zu erklĂ€ren und die wichtigsten neuen Einheiten kurz zu beschreiben.researc

    Cuspate-lobate folding in glacial sediments revealed by a small-scale 3-D seismic survey

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    We carried out a small-scale 3-D seismic survey (120 × 120 m2, bin size 1.5 m) in advance of a research borehole. The target consists of 150 m of Quaternary sediments in a glacially overdeepened valley. We used a wheelbarrow-mounted electrodynamic vibrator as seismic source and chose a simple orthogonal layout. During one week of acquisition, we fired 1024 shots into 384 vertical geophones. The key processing step was the interpolation and regularization of traces, realized by common reflection surface (CRS) processing. This enhances data quality in low fold regions at small offsets. Despite the small source, the entire Quaternary fill and the base of the valley is imaged well. At a depth of 20–50 m, glaciotectonic deformation, in the form of cuspate-lobate folds, is visible, which was not recognized previously in a 2-D seismic profile that runs along the edge of the 3-D area. The folding indicates that compressional glacial stresses acted on layers of stiff till and less competent clastics. We interpret that the varying fold axes' directions indicate varying stress fields during the Last Glacial Maximum. Cuspate-lobate folding has hitherto not been used to describe the deformation of glacial sediments

    Safety and efficacy of a lifestyle intervention for pregnant women to prevent excessive maternal weight gain: a cluster-randomized controlled trial

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    Background: Excessive gestational weight gain (GWG) is associated with short- and long-term health problems among mothers and their offspring. There is a strong need for effective intervention strategies targeting excessive GWG to prevent adverse outcomes. Methods: We performed a cluster-randomized controlled intervention trial in eight gynecological practices evaluating the feasibility and effectiveness of a lifestyle intervention presented to all pregnant women; 250 healthy, pregnant women were recruited for the study. The intervention program consisted of two individually delivered counseling sessions focusing on diet, physical activity, and weight monitoring. The primary outcome was the proportion of pregnant women exceeding weight gain recommendations of the Institute of Medicine (IOM). Secondary outcome variables were maternal weight retention and short-term obstetric and neonatal outcomes. Results: The intervention resulted in a lower proportion of women exceeding IOM guidelines among women in the intervention group (38\%) compared with the control group (60\%) (odds ratio (OR): 0.5; 95\% confidence interval (CI): 0.3 to 0.9) without prompting an increase in the proportion of pregnancies with suboptimal weight gain (19\% vs. 21\%). Participants in the intervention group gained significantly less weight than those in the control group. Only 17\% of the women in the intervention group showed substantial weight retention of more than 5 kg compared with 31\% of those in the control group at month four postpartum (pp) (OR: 0.5; 95\% CI: 0.2 to 0.9). There were no significant differences in obstetric and neonatal outcomes. Conclusions: Lifestyle counseling given to pregnant women reduced the proportion of pregnancies with excessive GWG without increasing suboptimal weight gain, and may exert favorable effects on pp weight retention

    Long sequence of Quaternary Rocks in the Heidelberg Basin Depocentre

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    Die neue Forschungs-Kernbohrung aus Heidelberg wird beschrieben und gegliedert. Die Forschungs- und BohraktivitĂ€ten im Heidelberger Becken (HDB) begannen im Jahr 2002; sie erschließen ein kontinentales Sedimentarchiv im Oberrheingraben (URG). Im HDB wird eine der lĂ€ngsten Sedimentabfolgen quartĂ€rer Sedimente in Europa erwartet, dank kontinuierlicher Subsidenz des Beckens in Verbindung mit kontinuierlichem Input von Sedimenten unterschiedlicher Herkunft. Das HDB befindet sich auf halber Strecke zwischen dem alpinen Einzugsgebiet des Rheins und seiner MĂŒndung in die Nordsee. Eine kontinuierliche Sedimentation ist hier eher möglich als am Alpenrand mit seinen Schmelzwasser-Erosionsereignissen oder an der KĂŒste mit ihren Meeresspiegelschwankungen. Dieser eher geringe Einfluss des Klimas hat zur Folge, dass die Tektonik eine umso grĂ¶ĂŸere Rolle bei der Steuerung der Sedimentation spielt. Die ĂŒber 500 m mĂ€chtige quartĂ€re Abfolge ist daher in erster Linie durch Tektonik kontrolliert, wobei Klimasignale ebenfalls erkannt werden können. Die hier vorgestellte Gliederung der Abfolge beruht auf Provenienz, Lithofazies und wechselnden VerhĂ€ltnissen von Akkomodationsraum und Sedimentinput (a/s-ratio). Dazu kommen biostratigraphische Zeitmarken. Im skizzierten Sedimentations-Szenario dominieren fluviale VerhĂ€ltnisse; dazwischen zwei lakustrine Abschnitte. Letztere sind verknüpft mit zunehmendem Akkomodationsraum, der in mindestens einer Zeitscheibe über die Grabenrandstörung hinweg sich bis in die TĂ€ler des Odenwalds erstreckt.researc

    Time Period From Onset of Pain to Hospital Admission and Patients' Awareness in Acute Pancreatitis

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    Objectives: This study aimed to explore the period between onset of pain and hospital-admission (pain-to-admission time) in patients with acute pancreatitis (AP), to investigate the prognostic value and associated factors of this time, and to ascertain the knowledge about the pancreas in these patients. Methods: An analysis of a prospective multicenter study was done, which included 188 patients with AP. Results: Median pain-to-admission time was 27 hours (interquartile range, 6.0-72.0). Median pain-to-admission time was significantly shorter in intensive care unit (ICU) patients (10 hours) compared to non-ICU patients (36 hours) (P = 0.045). Short pain-to-admission time was associated with high pain level. Median pain level (0, no pain; 10, maximal pain) was 8.0 (interquartile range, 7.0-10.0). Older age correlated with lower pain level (r = -0.26; P = 0.002). Multiple logistic regression analysis including the admission values for serum lipase and C-reactive protein and the corresponding interactions to the pain-to-admission time showed substantial discriminative ability regarding ICU admission (concordance index, 0.706; P = 0.006). 86% (112/130) knew that they have a pancreas, 72% (81/112) of these patients knew that AP exists, and 56% (45/81) recognized that AP is potentially fatal. Conclusions: Knowledge about AP in hospitalized AP patients is poor. Serum lipase and C-reactive protein in dependency of the pain-to-admission time might be a suitable predictor for severity of AP

    TassDB2 - A comprehensive database of subtle alternative splicing events

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    Background: Subtle alternative splicing events involving tandem splice sites separated by a short (2-12 nucleotides) distance are frequent and evolutionarily widespread in eukaryotes, and a major contributor to the complexity of transcriptomes and proteomes. However, these events have been either omitted altogether in databases on alternative splicing, or only the cases of experimentally confirmed alternative splicing have been reported. Thus, a database which covers all confirmed cases of subtle alternative splicing as well as the numerous putative tandem splice sites (which might be confirmed once more transcript data becomes available), and allows to search for tandem splice sites with specific features and download the results, is a valuable resource for targeted experimental studies and large-scale bioinformatics analyses of tandem splice sites. Towards this goal we recently set up TassDB (Tandem Splice Site DataBase, version 1), which stores data about alternative splicing events at tandem splice sites separated by 3 nt in eight species. \ud Description: We have substantially revised and extended TassDB. The currently available version 2 contains extensive information about tandem splice sites separated by 2-12 nt for the human and mouse transcriptomes including data on the conservation of the tandem motifs in five vertebrates. TassDB2 offers a user-friendly interface to search for specific genes or for genes containing tandem splice sites with specific features as well as the possibility to download result datasets. For example, users can search for cases of alternative splicing where the proportion of EST/mRNA evidence supporting the minor isoform exceeds a specific threshold, or where the difference in splice site scores is specified by the user. The predicted impact of each event on the protein is also reported, along with information about being a putative target for the nonsense-mediated decay \ud (NMD) pathway. Links are provided to the UCSC genome browser and other external resources.\ud Conclusion: TassDB2, available via http://www.tassdb.info, provides comprehensive resources for researchers interested in both targeted experimental studies and large-scale bioinformatics analyses of short distance tandem splice sites.\ud \ud doi: 10.1186/1471-2105-11-216\u
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