472 research outputs found
Closure to “Self-Managed Learning Model for Civil Engineering Continuing Training” by S. T. Muench
No full textGraphene electrically tuneable third harmonic generation
No full textElectrical control of the nonlinear optical response enables applications such as gate-tunable switches and frequency converters. Graphene displays strong-light matter interaction and electrically and broadband tunable third order nonlinear susceptibility. We show that the third harmonic generation efficiency in graphene can be tuned by over two orders of magnitude by controlling the Fermi energy and the incident photon energy
(Table A2) Bottom layer properties during Nathanial B. Palmer cruise NBP04-08 to the southern Ocean, October 2004
No full textDissolved oxygen was originally given in ml/l and was recalculated to µmol/l by multiplying by 44.66; Definition of concentration at bottom and accross bottom layer thickness follows Muench et al. (2009)
(Table A1) Bottom layer properties during Nathanial B. Palmer cruise NBP00-08 to the southern Ocean, December 2000/January 2001
No full textDissolved oxygen was originally given in ml/l and was recalculated to µmol/l by multiplying by 44.66; Definition of concentration at bottom and accross bottom layer thickness follows Muench et al. (2009). No station list was available for this campaign
Spherical-Supported Membranes as Platforms for Screening Against Membrane Protein Targets
No full textScreening assays performed against membrane protein targets (e.g. phage display) are hampered by issues arising from protein expression and purification, protein stability in detergent solutions and epitope concealment by detergent micelles. Here, we have studied a fast and simple method to improve screening against membrane proteins: spherical-supported bilayer lipid membranes (“SSBLM”). SSBLMs can be quickly isolated via low-speed centrifugation and redispersed in liquid solutions while presenting the target protein in a native-like lipid environment. To provide proof-of-concept, SSBLMs embedding the polytopic bacterial nucleoside transporter NupC were assembled on 100- and 200 nm silica particles. To test specific binding of antibodies, NupC was tagged with a poly-histidine epitope in one of its central loops between two transmembrane helices. Fluorescent labelling, small angle X-ray scattering (SAXS) and cryo-electron microscopy (cryo-EM) were used to monitor formation of the SSBLMs. Specific binding of an anti-his antibody and a gold-nitrilotriacetic acid (NTA) conjugate probe was confirmed with ELISAs and cryo-EM. SSBLMs for screening could be made with purified and lipid reconstituted NupC, as well as crude bacterial membrane extracts. We conclude that SSBLMs are a promising new means of presenting membrane protein targets for (biomimetic) antibody screening in a native-like lipid environment
The nature of the dense core population in the Pipe Nebula : core and cloud kinematics from C18O observations
No full textWe present molecular line observations of 94 dark cloud cores identified in the Pipe nebula through near-IR extinction mapping. Using the Arizona Radio Observatory 12m telescope, we obtained spectra of these cores in the J = 1-0 transition of (CO)-O-18. We used the measured core parameters, T-R*, Delta(v), v(lsr,) radius, and mass, to explore the internal kinematics of the cores, as well as their radial motions through the larger molecular cloud. We find that the vast majority of the dark extinction cores are true cloud cores, rather than the superposition of unrelated filaments. While we identify no significant correlations between the cores' internal gas motions and their other physical parameters, we identify spatially correlated radial velocity variations that outline two main kinematic components of the cloud. The largest is a 15 pc long filament that is surprisingly narrow both in spatial dimensions and in radial velocity. Beginning in the "Stem'' of the Pipe, this filament displays uniformly small (CO)-O-18 line widths (Delta v similar to 0.4 km s(-1)), as well as core-to-core motions only slightly in excess of the gas sound speed. The second component outlines what appears to be part of a large (2 pc; 10(3)M(circle dot)) ringlike structure. Cores associated with this component display both larger line widths and core-to-core motions than cores in the main cloud. The Pipe molecular ring may represent a primordial structure related to the formation of this cloud
Miocene deep-water agglutinated foraminifera from the Lomonosov Ridge and the opening of the Fram Strait
No full textDeep-water agglutinated Foraminifera (DWAF) were recovered from Miocene to Pliocene sediments in 103 samples
from IODP Hole M0002A on the Lomonosov Ridge. The First Occurrence of DWAF in Hole M0002A is observed just above the color change corresponding to the boundary between Lithological Subunits 1/4 and 1/5 in Core section –44X-1. The foraminiferal record of Hole M0002A consists entirely of agglutinated benthic species, largely sparse assemblages containing Cyclammina pusilla and Alveolophragmium polarensis. The faunal succession in Hole M0002A is subdivided into three assemblages based on the stratigraphic
ranges of characteristic taxa: (1) a relatively diverse assemblage at the base of Lithological Subunit 1/4 (Cores 44X-1 to –38X), with abundant agglutinated foraminifera including Reticulophragmium pusillum and Ammolagena clavata, indicating connections with the
North Atlantic. This assemblage displays the best preservation, which is here attributed to higher concentrations of dissolved silica in pore waters (2) A less diverse assemblage characterized by Alveolophragmium polarensis with Adercotryma agterbergi, in the lower
part of Lithological Subunit 1/3 (Cores –38X to –35X); (3) a sparse residual assemblage within Lithological Subunit 1/3 with Rhabdammina spp., A. polarensis and R. pusillum indicating poor preservation of organically-cemented DWAF in Cores –34X to –10X.
A comparison of the DWAF assemblages from the Lomonosov Ridge with previously studied Miocene assemblages from ODP
Hole 909C in the Fram Strait, Norwegian-Greenland Sea (Kaminski et al. 2005), suggests that the inflow of Atlantic intermediate water into the Arctic Ocean began prior to 17.5 Ma
Die Bedeutung der Aktinomykose in der Gynäkologie und Geburtshilfe
No full textDas erste Auftreten von Aktinomykose beim Menschen wurde 1878 durch den Berliner Chirurgen James Israel berichtet. 1881 wurde der erste Fall einer Genitalaktinomykose bekannt.
Die Aktinomykose ist eine chronisch-eitrige Infektionskrankheit mit charakteristischem Auftreten von multiplen Abszessen und Fistelungen. Sie weist eine außergewöhnlich starke Rezidivhäufigkeit auf.
Die Aktinomykose gliedert sich in fünf verschiedene Formen:
1. Zervikofaziale Aktinomykose
2. Thorakopulmonale Aktinomykose
3. Abdominalaktinomykose
4. Urogenitalaktinomykose
5. Aktinomykosebefall anderer Organe wie des ZNS durch
hämatogene Streuung
In dieser Arbeit wird zunächst ganz allgemein über die eigentlichen Erreger der Aktinomykose informiert, sowie über die notwendigen Begleitkeime. Ätiologie und Pathogenese werden diskutiert, hierbei wird besonders der endogene Infektionsmodus hervorgehoben. Es schließen sich die Ergebnisse epidemiologischer Untersuchungen an, die auf Erkrankungshäufigkeit, Geschlechtsverteilung, Erkrankungsalter und Prädilektionsstellen Auskunft geben.
Nach einer genaueren Beschreibung des klinischen Bildes der Aktinomykose werden die Diagnosemöglichkeiten erläutert.
Auch Differentialdiagnosen sowie Therapiemöglichkeiten und Prophylaxemethoden werden im allgemeinen Teil kurz erwähnt, wobei hier der Antibiotika und der operativen Therapie in der heutigen Zeit besondere Bedeutung zukommt.
Diese Arbeit beschäftigt sich speziell mit dem gynäkologischen Manifestationsort der Aktinomykose.
Zunächst werden hier der geschichtliche Verlauf und die Epidemiologie der Genitalaktinomykose beschrieben. Im folgenden Teil „Ätiologie und Pathogenese“ wird unterschieden zwischen den Genitalaktinomykosen mit und ohne kontrazeptive(n) Maßnahmen. Eine erhöhte Morbidität fällt hier besonders bei IUP-Trägerinnen auf, weshalb auch die unterschiedlichen IUP-Typen näher beschrieben werden und deren pathogene Wirkung gesondert erläutert wird. Anschließend wird die Klinik der Genitalaktinomykose genauestens beschrieben, die sich in drei Abschnitte einteilt, (1. Anfangsstadium 2. Tumorstadium 3. Fistelstadium), sowie auch die pathologische Anatomie.
Die Diagnostik der Genitalaktinomykose kann mit klinisch chemischen Untersuchungen erfolgen, aber auch durch mikrobiologische oder bildgebende Verfahren. Die verschiedenen Differentialdiagnosen werden diskutiert, die wohl am häufigsten gestellte ist die Neoplasie.
Auf den speziellen Fall der Genitalaktinomykose während der Schwangerschaft wird in einem gesondertem Kapitel kurz eingegangen. Hierüber ist in der Weltliteratur allerdings sehr wenig veröffentlicht worden.
Die heutige Therapie der Genitalaktinomykose stellt die operative Sanierung in Verbindung mit der antibiotischen Behandlung dar.
Um einer Genitalaktinomykose vorzubeugen sollten vor allem bei der Risikogruppe der IUP-Trägerinnen prophylaktische Maßnahmen ergriffen werden
Rapid Accretion State Transitions following the Tidal Disruption Event AT2018fyk
No full textFollowing a tidal disruption event (TDE), the accretion rate can evolve from quiescent to near-Eddington levels and back over timescales of months to years. This provides a unique opportunity to study the formation and evolution of the accretion flow around supermassive black holes (SMBHs). We present 2 yr of multiwavelength monitoring observations of the TDE AT2018fyk at X-ray, UV, optical, and radio wavelengths. We identify three distinct accretion states and two state transitions between them. These appear remarkably similar to the behavior of stellar-mass black holes in outburst. The X-ray spectral properties show a transition from a soft (thermal-dominated) to a hard (power-law-dominated) spectral state around Lbol ∼ few × 10−2 LEdd and the strengthening of the corona over time ∼100–200 days after the UV/optical peak. Contemporaneously, the spectral energy distribution (in particular, the UV to X-ray spectral slope αox) shows a pronounced softening as the outburst progresses. The X-ray timing properties also show a marked change, initially dominated by variability at long (>day) timescales, while a high-frequency (∼10−3 Hz) component emerges after the transition into the hard state. At late times (∼500 days after peak), a second accretion state transition occurs, from the hard into the quiescent state, as identified by the sudden collapse of the bolometric (X-ray+UV) emission to levels below 10−3.4 LEdd. Our findings illustrate that TDEs can be used to study the scale (in)variance of accretion processes in individual SMBHs. Consequently, they provide a new avenue to study accretion states over seven orders of magnitude in black hole mass, removing limitations inherent to commonly used ensemble studies
Asymptotic properties of dynamic stochastic parameter estimates (III)
No full textAbstractIn this paper we establish three theorems concerning the asymptotic distributions of ordinary least-squares estimates of the parameters of a stochastic difference equation. We show that, if there is at least one root of the associated characteristic equation with modulus less than one and if all the roots have moduli different from one, the vector of least-squares estimates converges in distribution to a normally distributed vector. The distribution of the limiting vector is degenerate if there is at least one root with modulus greater than one. The results we obtain represent extensions of results proviously obtained by H. B. Mann and A. Wald, H. Rubin, J. S. White, T. W. Anderson, M. M. Rao, T. J. Muench, and the author
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