Autocalibration with the Minimum Number of Cameras with Known Pixel Shape

In 3D reconstruction, the recovery of the calibration parameters of the cameras is paramount since it provides metric information about the observed scene, e.g., measures of angles and ratios of distances. Autocalibration enables the estimation of the camera parameters without using a calibration device, but by enforcing simple constraints on the camera parameters. In the absence of information about the internal camera parameters such as the focal length and the principal point, the knowledge of the camera pixel shape is usually the only available constraint. Given a projective reconstruction of a rigid scene, we address the problem of the autocalibration of a minimal set of cameras with known pixel shape and otherwise arbitrarily varying intrinsic and extrinsic parameters. We propose an algorithm that only requires 5 cameras (the theoretical minimum), thus halving the number of cameras required by previous algorithms based on the same constraint. To this purpose, we introduce as our basic geometric tool the six-line conic variety (SLCV), consisting in the set of planes intersecting six given lines of 3D space in points of a conic. We show that the set of solutions of the Euclidean upgrading problem for three cameras with known pixel shape can be parameterized in a computationally efficient way. This parameterization is then used to solve autocalibration from five or more cameras, reducing the three-dimensional search space to a two-dimensional one. We provide experiments with real images showing the good performance of the technique.Comment: 19 pages, 14 figures, 7 tables, J. Math. Imaging Vi

Dogs as carriers of virulent and resistant genotypes of Clostridioides difficile

Abstract While previous research on zoonotic transmission of community-acquired Clostridioides difficile infection (CA-CDI) focused on food-producing animals, the present study aimed to investigate whether dogs are carriers of resistant and/or virulent C. difficile strains. Rectal swabs were collected from 323 dogs and 38 C. difficile isolates (11.8%) were obtained. Isolates were characterized by antimicrobial susceptibility testing, whole-genome sequencing (WGS) and a DNA hybridization assay. Multilocus sequence typing (MLST), core genome MLST (cgMLST) and screening for virulence and antimicrobial resistance genes were performed based on WGS. Minimum inhibitory concentrations for erythromycin, clindamycin, tetracycline, vancomycin and metronidazole were determined by E-test. Out of 38 C. difficile isolates, 28 (73.7%) carried genes for toxins. The majority of isolates belonged to MLST sequence types (STs) of clade I and one to clade V. Several isolates belonged to STs previously associated with human CA-CDI. However, cgMLST showed low genetic relatedness between the isolates of this study and C. difficile strains isolated from humans in Austria for which genome sequences were publicly available. Four isolates (10.5%) displayed resistance to three of the tested antimicrobial agents. Isolates exhibited resistance to erythromycin, clindamycin, tetracycline and metronidazole. These phenotypic resistances were supported by the presence of the resistance genes erm(B), cfr(C) and tet(M). All isolates were susceptible to vancomycin. Our results indicate that dogs may carry virulent and antimicrobial-resistant C. difficile strains.1 Introduction 2 Methods 2.1 Sampling and ethics 2.2 Isolation and identification of Clostridioides difficile 2.3 Antimicrobial susceptibility testing 2.4 Whole-genome sequencing and comparative genomic analysis 2.5 Statistical analysis 3 Results 3.1 Prevalence of Clostridioides difficile and risk factors for shedding 3.2 Antimicrobial susceptibility testing and detection of antimicrobial resistance determinants 3.3 Genomic characterization of canine Clostridioides difficile 3.4 Genome annotation and comparison 4 Discussio

Rethinking Service Systems and Public Policy: A Transformative Refugee Service Experience Framework

The global refugee crisis is a complex humanitarian problem. Service researchers can assist in solving this crisis because refugees are immersed in complex human service systems. Drawing on marketing, sociology, transformative service, and consumer research literature, this study develops a Transformative Refugee Service Experience Framework to enable researchers, service actors, and public policy makers to navigate the challenges faced throughout a refugee’s service journey. The primary dimensions of this framework encompass the spectrum from hostile to hospitable refugee service systems and the resulting suffering or well-being in refugees’ experiences. The authors conceptualize this at three refugee service journey phases (entry, transition, and exit) and at three refugee service system levels (macro, meso, and micro) of analysis. The framework is supported by brief examples from a range of service-related refugee contexts as well as a Web Appendix with additional cases. Moreover, the authors derive a comprehensive research agenda from the framework, with detailed research questions for public policy and (service) marketing researchers. Managerial directions are provided to increase awareness of refugee service problems; stimulate productive interactions; and improve collaboration among public and nonprofit organizations, private service providers, and refugees. Finally, this work provides a vision for creating hospitable refugee service systems

The genetic study of three population microisolates in South Tyrol (MICROS): study design and epidemiological perspectives

<p>Abstract</p> <p>Background</p> <p>There is increasing evidence of the important role that small, isolated populations could play in finding genes involved in the etiology of diseases. For historical and political reasons, South Tyrol, the northern most Italian region, includes several villages of small dimensions which remained isolated over the centuries.</p> <p>Methods</p> <p>The MICROS study is a population-based survey on three small, isolated villages, characterized by: old settlement; small number of founders; high endogamy rates; slow/null population expansion. During the stage-1 (2002/03) genealogical data, screening questionnaires, clinical measurements, blood and urine samples, and DNA were collected for 1175 adult volunteers. Stage-2, concerning trait diagnoses, linkage analysis and association studies, is ongoing. The selection of the traits is being driven by expert clinicians. Preliminary, descriptive statistics were obtained. Power simulations for finding linkage on a quantitative trait locus (QTL) were undertaken.</p> <p>Results</p> <p>Starting from participants, genealogies were reconstructed for 50,037 subjects, going back to the early 1600s. Within the last five generations, subjects were clustered in one pedigree of 7049 subjects plus 178 smaller pedigrees (3 to 85 subjects each). A significant probability of familial clustering was assessed for many traits, especially among the cardiovascular, neurological and respiratory traits. Simulations showed that the MICROS pedigree has a substantial power to detect a LOD score ≥ 3 when the QTL specific heritability is ≥ 20%.</p> <p>Conclusion</p> <p>The MICROS study is an extensive, ongoing, two-stage survey aimed at characterizing the genetic epidemiology of Mendelian and complex diseases. Our approach, involving different scientific disciplines, is an advantageous strategy to define and to study population isolates. The isolation of the Alpine populations, together with the extensive data collected so far, make the MICROS study a powerful resource for the study of diseases in many fields of medicine. Recent successes and simulation studies give us confidence that our pedigrees can be valuable both in finding new candidates loci and to confirm existing candidate genes.</p

Algorithm Animation of Computational Chains

AVISTA (Visualization & Interactive Steering for Task Activation) is part of the modular computer-aided control engineering environment ANDECS and provides a framework for the visualization of engineering computations. Available graphical modules can be used both for offline & online visualization, interactive steering, and information zooming. Multiple graphical displays in multiple windows are supported. AVISTA makes full use of databased integration of software modules

Entscheidungsunterstuetzende Visualisierung bei der mehrzieligen Entwurfsoptimierung

Die Komplexitaet beim mehrzieligen Entwurf waechst mit der Variabilitaet in den Entwurfsentscheidungen und mit der Quantitaet der zur Beurteilung notwendigen Daten. Unser Ansatz zur Datenreduktion und Informationsgewinnung ist der Einsatz eines (aktiven) graphischen Editors fuer parallele Koordinaten. Parallele Koordinaten sind eine Moeglichkeit der Darstellung mehrparametrischer Daten. Die Funktionalitaet des graphischen Editors wird an einem Anwendungsbeispiel demonstriert. Die sofware-technische Realisierung erfolgt im Rahmen von ANDECS. Die modulare Realisierung des Editors ermoeglicht unter anderem den Einsatz und Austausch beliebiger, problemangepasster Grafikmodule fuer online und offline Visualisierung