Search results for "EXPANSION"
showing 10 items of 630 documents
Charge fluctuations and electric mass in a hot meson gas
2006
Net-Charge fluctuations in a hadron gas are studied using an effective hadronic interaction. The emphasis of this work is to investigate the corrections of hadronic interactions to the charge fluctuations of a non-interacting resonance gas. Several methods, such as loop, density and virial expansions are employed. The calculations are also extended to SU(3) and some resummation schemes are considered. Although the various corrections are sizable individually, they cancel to a large extent. As a consequence we find that charge fluctuations are rather well described by the free resonance gas.
Pants complex, TQFT and hyperbolic geometry
2021
We present a coarse perspective on relations of the $SU(2)$-Witten-Reshetikhin-Turaev TQFT, the Weil-Petersson geometry of the Teichm\"uller space, and volumes of hyperbolic 3-manifolds. Using data from the asymptotic expansions of the curve operators in the skein theoretic version of the $SU(2)$-TQFT, as developed by Blanchet, Habegger, Masbaum and Vogel, we define the quantum intersection number between pants decompositions of a closed surface. We show that the quantum intersection number admits two sided bounds in terms of the geometric intersection number and we use it to obtain a metric on the pants graph of surfaces. Using work of Brock we show that the pants graph equipped with this …
Forward light-by-light scattering and electromagnetic correction to hadronic vacuum polarization
2023
Lattice QCD calculations of the hadronic vacuum polarization (HVP) have reached a precision where the electromagnetic (e.m.) correction can no longer be neglected. This correction is both computationally challenging and hard to validate, as it leads to ultraviolet (UV) divergences and to sizeable infrared (IR) effects associated with the massless photon. While we precisely determine the UV divergence using the operator-product expansion, we propose to introduce a separation scale $\Lambda\sim400\;$MeV into the internal photon propagator, whereby the calculation splits into a short-distance part, regulated in the UV by the lattice and in the IR by the scale $\Lambda$, and a UV-finite long-di…
Quarkonium suppression in heavy-ion collisions: an open quantum system approach
2016
We address the evolution of heavy-quarkonium states in an expanding quark-gluon plasma by implementing effective field theory techniques in the framework of open quantum systems. In this setting we compute the nuclear modification factors for quarkonia that are $S$-wave Coulombic bound states in a strongly-coupled quark-gluon plasma. The calculation is performed at an accuracy that is leading-order in the heavy-quark density expansion and next-to-leading order in the multipole expansion. The quarkonium density-matrix evolution equations can be written in the Lindblad form, and, hence, they account for both dissociation and recombination. Thermal mass shifts, thermal widths and the Lindblad …
Increased autophagy and apoptosis contribute to muscle atrophy in a myotonic dystrophy type 1 Drosophila model
2015
ABSTRACT Muscle mass wasting is one of the most debilitating symptoms of myotonic dystrophy type 1 (DM1) disease, ultimately leading to immobility, respiratory defects, dysarthria, dysphagia and death in advanced stages of the disease. In order to study the molecular mechanisms leading to the degenerative loss of adult muscle tissue in DM1, we generated an inducible Drosophila model of expanded CTG trinucleotide repeat toxicity that resembles an adult-onset form of the disease. Heat-shock induced expression of 480 CUG repeats in adult flies resulted in a reduction in the area of the indirect flight muscles. In these model flies, reduction of muscle area was concomitant with increased apopto…
Asymptotic expansions and causal representations through the loop-tree duality
2022
Large-scale particle physics experiments have provided a vast amount of high-quality data during the last decades. A leading role has been played by the Large Hadron Collider where the evaluation and analysis of its second run is currently still in progress while the third run is about to start, promising ever higher precision data of particle collisions and subsequent decays. The agreement between experimental observations and theoretical predictions using the Standard Model of Particle Physics is excellent. Indeed, this is a problem since there are currently few clues for how genuine shortcomings of the model can be overcome. New physics phenomena can appear either at higher energies, whi…
Tomographic evaluation of dentoskeletal effects of rapid maxillary expansion using Haas and Hyrax palatal expanders in children : a randomized clinic…
2020
Background Rapid maxillary expansion (RME) is a usual procedure for correcting the transversal maxillary deficiency. Among the most used appliances are the Haas type (tooth-tissue-borne) and Hyrax (tooth-borne) whose main difference is the design. This study aimed to evaluate the dentoskeletal effects of RME using two different expanders in children. Material and methods The sample was composed of 42 children of both gender presenting unilateral or bilateral posterior crossbite with mean age 9.49 (SD± 1.35). Patients were randomized into two groups according to the type of expander: Hyrax (n= 21, 9 boys and 12 girls) and Haas (n= 21, 11 boys and 10 girls). Multiplanar coronal and axial slic…
Prediction of dilutional acidosis based on the revised classical dilution concept for bicarbonate
2004
Due to the controversy surrounding the term dilutional acidosis, the classical dilution concept for bicarbonate has been rigorously revised for the prediction of pH, actual bicarbonate concentration, and base excess. In the algorithms derived for buffer solutions, blood, and whole body (1-, 2-, and 3-fluid compartment), only bicarbonate is considered. On dilution at constant Pco2, the final concentration of bicarbonate is the sum in terms of pH, due to the following processes: dilution, formation from chemical reaction with the nonbicarbonate buffers phosphate, hemoglobin, and plasma proteins, and transfer from erythrocytes and interstitial fluid to plasma. At constant Pco2, the level of c…
Orthopedic-orthodontic treatment of the patient with Turner's syndrome: Review of the literature and case report.
2018
Aims Turner syndrome (TS) patients have phenotypical variable presentations and they are more susceptible to endocrine, auto-immune, and structural anomalies. Typical clinical characteristics are short stature and premature ovarian insufficiency. Patients with TS show a typical cranial-facial morphology with bi-maxillary bi-retrusion, high-arched palate, micrognathia, and class II malocclusion. Aim of our study is to present the orthopedic-orthodontic treatment approach of a young TS patient and data of stability after 7 years. Methods and results A careful analysis of anamnestic data was performed. After extraoral and intraoral examination, cephalometric measurements and examination of mod…
Expanded forehead (Fricke) flap for large defect of lateral canthal area
1993
The use of an expanded forehead (Fricke) flap to repair large full thickness defects of the lateral canthus and/or of the upper eyelid is presented. The reconstruction is performed in two stages. In the first stage, a rectangular, 25 ml tissue expander (6 cm in width and 2 cm in length) is inserted under the skin lateral to and above the eyebrow; expansion is completed in about three weeks. At the second stage, the lesion is excised, and the laterally based expanded flap is elevated. Using the expanded Fricke flap, thinner, abundant skin is obtained, and the donor site is directly closed, without grafting and without distorting the eyebrow. If there is a shortage of conjunctiva, this can be…