On the topological entropy of families of braids

A method for computing the topological entropy of each braid in an infinite family, making use of Dynnikov's coordinates on the boundary of Teichm\"uller space, is described. The method is illustrated on two two-parameter families of braids.Comment: 17 pages, 2 figure

Analysis of Artifacts and Errors on Intraoral Phosphor Plate Radiographs: A Retrospective Study

Introduction. The advantages of phosphor plates (PPs), including their flexibility, thinness, and wireless connectivity, have contributed to their widespread use in dentistry alongside the advancement of digital radiography techniques. Continuous use of PPs and certain errors may lead to artifacts on the images. This retrospective study aimed to determine the frequency and types of intraoral PP artifacts. Methods. This study was conducted on 814 intraoral PP radiographs, including periapical and bitewing images. The errors and artifacts were classified into 4 main categories: technical errors, plate-related artifacts, scanner-induced artifacts, and ambient light artifacts. Results. A total of 656 periapical and 158 bitewing radiographs were examined. The most observed artifacts on the radiographs were plate-related artifacts, followed by technical errors (n=542, n=461, respectively). Within the category of plate-related artifacts, the most common artifacts were cracks or scratches (n=418, 77.1%), while within the category of technical errors, these were cone-cut errors (n=188, 40.7%). Parallel or zigzag radiopaque lines were the most common scanner-induced artifacts (n=313, 98.7%) and fading was the most common ambient light artefact (n=93, 49.2%). On more than half of the PPs, more than one artifact group was observed. Conclusions. Cone-cut, cracks/scratches, parallel zigzag radiopaque lines, and fading were common PP artifacts and errors in this study. The analysis revealed that over half of the PPs exhibited appearance of more than one artifact group. The high frequency of artifacts poses a risk of incorrect and incomplete diagnoses in radiographs, emphasizing the crucial importance of understanding the causes and developing effective prevention strategies for artifacts to enhance the reliability of diagnostic imaging and ensure the accuracy of patient assessments

Intersections of Multicurves on Small Genus Non–Orientable Surfaces

Let $K_{n}$ (n>1) be an $n$--punctured non--orientable surface of genus $2$ with 1 boundary component. We give formulae for calculating the geometric intersection number of an arbitrary multicurve with a relaxed multicurve on $K_{n}$ given their generalized Dynnikov coordinates

The effect of nasal septum deviation on subclinical cardiac autonomic dysfunction

Background: Nasal septum deviation is one of the most frequently encountered nasal pathology in otorhinolaryngology clinics. Disease with a high comorbidity such as obstructive sleep apnea syndrome (OSAS), among whose etiology septum deviation takes place, can cause subclinical pathologies like atrial fibrillation. The main objective of this study was to determine the effect of nasal septum deviation on subclinical cardiac pathologies.Methods: The study included a total of 80 patients which were a group of 40 patients who admitted to the otorhinolaryngology department with a complaint of nasal obstruction and were diagnosed as having nasal septum deviation and a control group of 40 patients who admitted to the same department with complaints other than nasal obstruction and had no nasal septum deviation for the period of April 2015-August 2015. Initially, all patients were performed rhinomanometric measurement and then the patients were required to grade their symptoms of nasal obstruction using a 10-unit visual analog scale (VAS). Following that, patients were performed to transthoracic echocardiography by cardiology department and all the results were compared between two groups.Results: In the patient group while the VAS and transnasal pressure were found meaningful higher, the transnasal flow was found meaningful lower than the control group. In the patient group PA septum, PA tricuspide, PA lateral-tricuspide, PA septum-tricuspide values were found meaningful higher than the control group. In the patient group left atrium width (LA), LA volume maximum, LA volume minimum and LA volume p values, which show the size of left atrium, were found meaningful high in comparison to the control group.Conclusions: As a result of the data obtained from this study, the research demonstrates that nasal septum deviation can cause subclinical cardiac pathologies such as atrial fibrillation and these pathologies can be detected with noninvasive methods such as echocardiography

Leptospirosis followed by Kawasaki-like disease: case report from an adult Swiss patient and review of the literature

Kawasaki disease (KD) is a vasculitis that mostly occurs in children, but rare cases in adults have been reported. We describe the case of a 43-year-old Swiss male who developed symptoms compatible with KD 7 weeks after leptospirosis, which was presumably acquired after swimming in a creek in the Swiss Alps. We performed a literature review and identified 10 other cases (all in children), in which Kawasaki-like disease was diagnosed in the context of leptospirosis. Outcome was favourable in most cases, including our patient. This exceptional case demonstrates both the possibility of autochthonous cases of leptospirosis in Switzerland as well as a possible association of leptospirosis with Kawasaki-like disease

Isolated zone I vertical fracture of first sacral vertebra: a case report

Isolated sacral fractures which occur by shear forces on the pelvic ring are seen less commonly and they are commonly transversely oriented. A 29-year-old Turkish female patient, who sat in front seat in the car, was unrestrained, and another car hit them from right front side of their vehicle. Physical examination revealed considerable tenderness over the right superior gluteal region and excruciating pain during sacral and iliac compression. There was no clear fracture line in her plain radiographs. CT revealed incomplete, zone I fracture located on the superior and anterior part of the first sacral vertebra. Type 1 lateral compression pelvic fractures are relatively common and they include impacted sacral and ipsilateral rami fractures. Only a few cases, related with the isolated sacral fracture, have been reported in the literature. To our knowledge, no isolated vertical zone I fracture of the first sacral vertebra which occurred with the lateral compression injury has been described previously. Fracture of the sacrum should be suspected in the presence of sacral pain and tenderness