Fermionic Ising glasses with BCS pairing interaction in the presence of a transverse field

In the present work we have analyzed a fermionic infinite-ranged Ising spin glass with a local BCS coupling in the presence of transverse field. This model has been obtained by tracing out the conduction electrons degrees of freedom in a superconducting alloy. The transverse field \Gamma is applied in the resulting effective model. The problem is formulated in the path integral formalism where the spins operators are represented by bilinear combination of Grassmann fields. The problem can be solved by combining previous approaches used to study a fermionic Heisenberg spin glass and a Ising spin glass in a transverse field. The results are show in a phase diagram T/J {\it versus} \Gamma/J (J is the standard deviation of the random coupling J_{ij}) for several values of g (the strength of the pairing interaction). For small g, the line transition T_c(\Gamma) between the normal paramagnetic phase and the spin glass phase decreases when increases \Gamma, until it reaches a quantum critical point. For increasing g, a PAIR phase (where there is formation of local pairs) has been found which disappears when is close to \Gamma_c showing that the transverse field tends to inhibited the PAIR phase.Comment: 2 pages, 2 figures, accepted in Physica C Proceedings M2SRI

EEG Korrelate und Gedächtnisleistungen bei spontanen fazialen Selbstberührungen

Die Beschreibung spontaner Berührungen des eigenen Körpers findet sich bereits in der psychologischen Forschungsliteratur der 1930er Jahre. Das spontane Berühren des eigenen Gesichts tritt Studien zufolge häufiger auf als das spontane Berühren anderer Körperteile. Trotz jahrzehntelanger Forschung sowie aktueller Präsenz des Themas im Zusammenhang mit der COVID-19-Pandemie, sind zentrale Fragen zu Auslösemechanismen und psychophysiologischen Funktionen von spontanen fazialen Selbstberührungen bislang unbeantwortet. Die vorliegende Dissertation liefert anhand neurophysiologischer sowie behavioraler Daten neue Erkenntnisse zu Funktionen von spontanen fazialen Selbstberührungen und trägt damit zur Weiterentwicklung der Theorie dieses Verhaltens bei

Distributed control architecture for real-time telerobotic operation

The emerging field of telerobotics places new demands on control system architecture to allow both autonomous operations and natural human-machine interfacing. The feasibility of multiprocessor systems performing parallel control computations is realizable. A practical distribution of control processors is presented and the issues involved in the realization of this architecture are discussed. A prototype dual axis controller based on the NOVIX computer is described, and results of its implementation are discussed. Application of this type of control system to a replicated, redundant manipulator system is also described

Three-dimensional single particle tracking in a light sheet microscope

Technical development in microscopy, and particularly in fluorescence microscopy, has facilitated the investigation of ever smaller details in biological specimen. The combination of specific labeling of molecular compounds, sophisticated optical setups and sensitive detectors enables observation of single molecules. Using fast video microscopy, it is now possible to directly observe the cell’s molecular machinery at work by tracking single molecules with high spatial and temporal resolution. Single molecule tracking can reveal detailed information about the dynamics of biological processes. However, technical requirements for single molecule detection limit the depth of field to less than 1 μm. Thus, single molecule tracking is typically limited to studying phenomena in planar membranes or, in extended specimen, often relies on two dimensional projections of short trajectory fragments. The work presented here strives to overcome these limitations by combining real-time three-dimensional localization of single particles with an active feedback loop to keep a particle of interest within the observation volume. To this end, a light sheet microscopy setup was designed and assembled around a commercial microscope body. It was equipped with a fast piezo stage for axial sample positioning. Three-dimensional spatial information was encoded in the shape of the point spread function by astigmatic detection and retrieved by real-time image analysis code developed for this purpose. A novel localization metric based on cross-correlation template matching was devised to enable tracking based on a low number of photons detected per particle. During post-processing, relative axial localizations determined from the image data were combined with the piezo stage position to obtain full three-dimensional particle trajectories. Mechanical and optical properties of the setup were thoroughly characterized using appropriate test samples. A temporal resolution down to 1,12 ms was achieved. The localization precision of the method was experimentally determined by repeated imaging of immobilized fluorescent beads. The capability to track single emitters was validated in a biochemical model system. Lipids labeled with a synthetic dye molecule were incorporated in the bilayer membrane of giant unilamellar vesicles and tracked on their spherical surface. Trajectories of more than 20 s duration could be obtained at as little as 130 photons detected per frame. An analysis of the photophysical properties revealed that observation times per particle were limited not by failure of the tracking algorithm but by photobleaching. Applicability of the method in biological specimen was proved by tracking fluorescent nanoparticles micro-injected into C. tentans salivary gland cell nuclei for more than 270 s in several thousand frames. Subsequently, the method was applied to track mRNA and rRNA particles in C. tentans salivary gland cell nuclei. Biomolecules were specifically labeled by complementary oligonucleotides carrying up to three synthetic dye molecules. It was possible to routinely acquire trajectories of particles with a diffusion coefficient of D = 1-2 μm2/s spanning ≥ 4 s and 4-5 μm in axial direction. The longest trajectories lasted more than 16 s and covered 10 μm axially. Both, observation time and axial range, were increased by more than one order of magnitude as compared to standard 2D tracking experiments. It was thus possible to investigate mobility states not on the basis of an ensemble of short observations but for individual particles

Microbiological Characteristics and Surgical Management of Animal-Bite-Related Oral & Maxillofacial Injuries: A Single Center's Experience

The objective of the current study is to retrospectively evaluate animal-bite injuries and to gain insight into the epidemiology, accident consequences and treatment concept of these accidents in oral and maxillofacial surgery. Data of patients, who were admitted January 2015 and April 2021, were retrospectively evaluated regarding the patients' characteristics (age, gender), facial distribution of substance defects/partial amputations, duration of hospitalization, operation treatments and antibiotic treatments. Data of 75 patients were included. Patients were bitten by dogs (n = 69.92%), cats (n = 4) and horses (n = 2). Lower eyelid/cheek complex was the most affected region (n = 37, 32.74%). Most of the patients between 0 and 3 years had to be operated on under general anesthesia (p = 0.011), while most of the adults could be operated on under local anesthesia (p = 0.007). In the age group 0-12 years, 30 patients (68%) were operated on under general anesthesia. Ampicillin/Sulbactam (48%) was the antibiotic most used. Antibiotics were adjusted after wound swabs in case of wound infections or critical wound conditions. This means that resistant antibiotics were stopped, and sensitive antibiotics were used. Structured surgical and antibiotic management of animal-bite wounds in the maxillofacial region is the most important factor for medical care to avoid long-term aesthetic consequences. Public health actions and policies under the leadership of an interdisciplinary committee could improve primary wound management, healing outcome and information status in the general population

2D versus 3D in laparoscopic surgery by beginners and experts: a randomized controlled trial on a pelvic trainer in objectively graded surgical steps

In dieser Studie haben wir die 2D mit der 3D Endoskopie in Bezug auf die Zeit, der Effizienz, der Optik und der Handhabung von Chirurgen unterschiedlichen Ausbildungsstandes verglichen.In this study we compare 2D and 3D endoscopy techniques in regard of time, efficiency, optics, and handling by surgeons with different degrees of experience

Die Komplikationshäufigkeit sonographisch gesteuerter Organpunktionen im Abdomen unter klinischen Alltagsbedingungen an einem kommunalen Krankenhaus der Maximalversorgung

Die Komplikationshäufigkeit sonographisch gesteuerter Organpunktionen im Abdomen unter klinischen Alltagsbedingungen an einem kommunalen Krankenhaus der Maximalversorgung Ziel: Die sonographisch gesteuerte Organpunktion im Abdomen gilt als sicheres Verfahren. Das Ziel dieser Studie war es die Komplikationshäufigkeit unter nicht-optimierten klinischen Alltagsbedingungen sowie Faktoren, welche mit einem erhöhten Risiko verbunden sind, zu untersuchen. Patienten und Methodik: Wir erhoben retrospektiv die Daten zu allen sonographisch gesteuerten Organpunktionen im Abdomen, die im Zeitraum vom 30.08.2001 bis zum 08.02.2012 in unserer Klinik vollzogen wurden. Hierzu erfassten wir patienten- und punktionsbezogene Parameter. Das Auftreten von Komplikationen wurde in leicht und schwer untergliedert. Ergebnisse: Ausgewertet wurden die Daten zu 989 Punktionen (774 Leber, 37 Pankreas, 39 Lymphknoten, 27 Niere, 95 Transplantat-Nieren, 17 sonstige abdominale Organe). Insgesamt traten (Mehrfachnennunen eingeschlossen) 110 leichte, entsprechend 11,1% (Schmerz: 63; asymptomatische freie Flüssigkeit: 27; asymptomatisches Hämatom: 20) und 22 schwere Komplikationen, entsprechend 2,2% (Hb-Abfall > 2g/dl Blut ohne Transfusion: 11; transfusionspflichtige Blutungen: 2; Intensivüberwachung: 5; Operation: 2; Tod: 2) auf. Der einzige, signifikant mit dem Auftreten schwerer Komplikationen verbundene Risikofaktor war die Durchführung einer therapeutischen Punktion (therapeutische Punktionen: 6/81, entsprechend 7,4% vs. Diagnostische Punktionen: 16/908, entsprechend 1,8%). Schlussfolgerung: Unter Berücksichtigung der von uns bewusst weit gewählten Definition schwerer Komplikationen war deren Rate in unserer Studie mit 2,2% relativ hoch. Insgesamt traten jedoch überwiegend leichte Komplikationen auf. Einziger Risikofaktor für das Auftreten von schweren Komplikationen war die Durchführung einer therapeutischen Punktion

On non-rank facets of the stable set polytope of claw-free graphs and circulant graphs

We deal with non-rank facets of the stable set polytope of claw-free graphs. We extend results of Giles and Trotter [7] by (i) showing that for any nonnegative integer a there exists a circulant graph whose stable set polytope has a facet-inducing inequality with (a,a+1)-valued coefficients (rank facets have only coefficients 0, 1), and (ii) providing new facets of the stable set polytope with up to five different non-zero coefficients for claw-free graphs. We prove that coefficients have to be consecutive in any facet with exactly two different non-zero coefficients (assuming they are relatively prime). Last but not least, we present a complete description of the stable set polytope for graphs with stability number 2, already observed by Cook [3] and Shepherd [18