189 research outputs found
Laser-camera composite sensing for road detection and tracing
An important feature in most urban roads and similar environments, such as in theme parks, campus sites, industrial estates, science parks, and the like, is the existence of pavements or curbs on either side de?ning the road boundaries. These curbs, which are mostly parallel to the road, can be harnessed to extract useful features of the road for implementing autonomous navigation or driver assistance systems. However, vision-alone methods for extraction of such curbs or road edge features with accurate depth information is a formidable task, as the curb is not conspicuous in the vision image and also requires the use of stereo images. Further, bad lighting, adverse weather conditions, nonlinear lens aberrations, or lens glare due to sun and other bright light sources can severely impair the road image quality and thus the operation of vision-alone methods. In this paper an alternative and novel approach involving the fusion of 2D laser range and monochrome vision image data is proposed to improve the robustness and reliability. Experimental results are presented to demonstrate the viability and effectiveness of the proposed methodology and its robustness to different road configurations and shadows
Estimating the incidence of equine viral arteritis and the sensitivity of its surveillance in the French breeding stock
Equine viral arteritis (EVA) may have serious economic impact on the equine industry. For this reason, it is monitored in many countries, especially in breeding stock, to avoid its spread during breeding activities. In France, surveillance is mainly based on serological tests, since mares are not vaccinated, but difficulties in interpreting certain series of results may impair the estimation of the number of outbreaks. In this study, we propose specific rules for identifying seroconversion in order to estimate the number of outbreaks that were detected by the breeding stock surveillance component (BSSC) in France between 2006 and 2013. A consensus among multidisciplinary experts was reached to consider seroconversion as a change in antibody titer from negative to at least 32, or as an eight-fold or greater increase in antibody level. Using these rules, 239 cases and 177 outbreaks were identified. Subsequently, we calculated the BSSC's sensitivity as the ratio of the number of detected outbreaks to the total number of outbreaks that occurred in breeding stock (including unreported outbreaks) estimated using a capture-recapture model. The total number of outbreaks was estimated at 215 (95% credible interval 195-249) and the surveillance sensitivity at 82% (CrI95% 71-91). Our results confirm EVA circulation in French breeding stock, show that neutralizing antibodies can persist up to eight years in naturally infected mares and suggest that certain mares have been reinfected. This study shows that the sensitivity of the BSSC is relatively high and supports its relevance to prevent the disease spreading through mating
Computational Method for Phase Space Transport with Applications to Lobe Dynamics and Rate of Escape
Lobe dynamics and escape from a potential well are general frameworks
introduced to study phase space transport in chaotic dynamical systems. While
the former approach studies how regions of phase space are transported by
reducing the flow to a two-dimensional map, the latter approach studies the
phase space structures that lead to critical events by crossing periodic orbit
around saddles. Both of these frameworks require computation with curves
represented by millions of points-computing intersection points between these
curves and area bounded by the segments of these curves-for quantifying the
transport and escape rate. We present a theory for computing these intersection
points and the area bounded between the segments of these curves based on a
classification of the intersection points using equivalence class. We also
present an alternate theory for curves with nontransverse intersections and a
method to increase the density of points on the curves for locating the
intersection points accurately.The numerical implementation of the theory
presented herein is available as an open source software called Lober. We used
this package to demonstrate the application of the theory to lobe dynamics that
arises in fluid mechanics, and rate of escape from a potential well that arises
in ship dynamics.Comment: 33 pages, 17 figure
The impact of a hand hygiene workshop on improving the knowledge of hand hygiene of medical students
Introduction and Objectives: Knowledge of hand hygiene is important for medical students. The aim of this study was to compare the knowledge before and after a workshop on hand hygiene held for medical students at the Faculty of Medicine, General Sir John Kotelawala Defence University, Sri Lanka.Methods: A self-administered, pre-tested validated questionnaire, based on hand hygiene guidelines of the World Health Organization (WHO), was distributed among the medical students before and after conducting a workshop on hand hygiene.Results were assessed by comparing the current guidelines set by the WHO with the knowledge of hand hygiene among the medical students.Results: All 177 students participated in the study before conducting the workshop. There were 104 (58.8%) preclinical and 73 (41.2%) clinical students. Of the 104 preclinical students, the percentage who knew the importance of âMy five moments for hand hygieneâ approach (hand hygiene before direct contact with patients, after direct contact with patients, before clean/aseptic procedures, after contact with blood/body fluid and after contact with patientâs surrounding) before conducting the workshop were 53.8%, 67.3%, 51.0%, 88.5% and 34.6% respectively. Of the 73 clinical students, the percentage who knew the importance of the âMy five moments for hand hygieneâ approach before conducting the workshop were 49.3%, 63.0%, 87.7%, 94.5% and 27.4% respectively. Of the 112 students who participated in the workshop, there were 68 (60.7%) preclinical and 44 (39.3%) clinical students. Of the 68 preclinical students, 77.9%, 79.4%, 91.2%, 95.6% and 70.6% knew the importance of the âMy five moments for hand hygieneâ approach post workshop. Post workshop, the percentage of the 44 clinical students who knew the importance of âMy five moments for hand hygieneâ approach were 90.9%, 88.6%, 93.2%, 97.7% and 81.8% respectively.Conclusions: The pre workshop knowledge of hand hygiene among the two categories of medical students was not satisfactory. The knowledge on each component of âMy five moments for hand hygieneâ concept improved to more than 70% after conducting the workshop. </p
On religion and cultural policy: notes on the Roman Catholic Church
This paper argues that religious institutions have largely been neglected within the study of cultural policy. This is attributed to the inherently secular tendency of most modern social sciences. Despite the predominance of the âsecularisation paradigmâ, the paper notes that religion continues to promote powerful attachments and denunciations. Arguments between the ânew atheistsâ, in particular, Richard Dawkins, and their opponents are discussed, as is Habermasâs conciliatory encounter with Joseph Ratzinger (later Pope Benedict XVI). The paper then moves to a consideration of the Roman Catholic Church as an agent of cultural policy, whose overriding aim is the promotion of âChristian consciousnessâ. Discussion focuses on the contested meanings of this, with reference to (1) the deliberations of Vatican II and (2) the exercise of theological and cultural authority by the Pope and the Congregation for the Doctrine of the Faith (CDF). It is argued that these doctrinal disputes intersect with secular notions of social and cultural policy and warrant attention outside the specialist realm of theological discourse
Nutrient-limited growth with non-linear cell diffusion as a mechanism for floral pattern formation in yeast biofilms
Available online 7 April 2018Abstract not availableAlexander Tam, J. Edward F. Green, Sanjeeva Balasuriya, Ee Lin Tek, Jennifer M. Gardner, Joanna F. Sundstrom, Vladimir Jiranek, Benjamin J. Binde
Chronic Muscle Weakness and Mitochondrial Dysfunction in the Absence of Sustained Atrophy in a Preclinical Sepsis Model
Chronic critical illness is a global clinical issue affecting millions of sepsis survivors annually. Survivors report chronic skeletal muscle weakness and development of new functional limitations that persist for years. To delineate mechanisms of sepsis-induced chronic weakness, we first surpassed a critical barrier by establishing a murine model of sepsis with ICU-like interventions that allows for the study of survivors. We show that sepsis survivors have profound weakness for at least 1 month, even after recovery of muscle mass. Abnormal mitochondrial ultrastructure, impaired respiration and electron transport chain activities, and persistent protein oxidative damage were evident in the muscle of survivors. Our data suggest that sustained mitochondrial dysfunction, rather than atrophy alone, underlies chronic sepsis-induced muscle weakness. This study emphasizes that conventional efforts that aim to recover muscle quantity will likely remain ineffective for regaining strength and improving quality of life after sepsis until deficiencies in muscle quality are addressed
On the Lagrangian Dynamics of Atmospheric Zonal Jets and the Permeability of the Stratospheric Polar Vortex
The Lagrangian dynamics of zonal jets in the atmosphere are considered, with
particular attention paid to explaining why, under commonly encountered
conditions, zonal jets serve as barriers to meridional transport. The velocity
field is assumed to be two-dimensional and incompressible, and composed of a
steady zonal flow with an isolated maximum (a zonal jet) on which two or more
travelling Rossby waves are superimposed. The associated Lagrangian motion is
studied with the aid of KAM (Kolmogorov--Arnold--Moser) theory, including
nontrivial extensions of well-known results. These extensions include
applicability of the theory when the usual statements of nondegeneracy are
violated, and applicability of the theory to multiply periodic systems,
including the absence of Arnold diffusion in such systems. These results,
together with numerical simulations based on a model system, provide an
explanation of the mechanism by which zonal jets serve as barriers to
meridional transport of passive tracers under commonly encountered conditions.
Causes for the breakdown of such a barrier are discussed. It is argued that a
barrier of this type accounts for the sharp boundary of the Antarctic ozone
hole at the perimeter of the stratospheric polar vortex in the austral spring.Comment: Submitted to Journal of the Atmospheric Science
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