Hidden and explicit quantum scale invariance

There exist renormalisation schemes that explicitly preserve the scale invariance of a theory at the quantum level. Imposing a scale invariant renormalisation breaks renormalisability and induces new non-trivial operators in the theory. In this work, we study the effects of such scale invariant renormalisation procedures. On the one hand, an explicitly quantum scale invariant theory can emerge from the scale invariant renormalisation of a scale invariant Lagrangian. On the other hand, we show how a quantum scale invariant theory can equally emerge from a Lagrangian visibly breaking scale invariance renormalised with scale dependent renormalisation (such as the traditional MS-bar scheme). In this last case, scale invariance is hidden in the theory, in the sense that it only appears explicitly after renormalisation.Comment: Minor changes, updated references, matches published versio

Recommandations for malaria prevention in moderate to low risk areas : traveller's choice and risk perception

Background. Le considérable déclin de la malaria au niveau mondial remet en question la stratégie de chimioprophylaxie pour les voyageurs à destination de pays à risque modéré à faible de malaria. Un consensus international de la meilleure stratégie de prévention reste à trouver. Suivant le mouvement actuel de partage décisionnel, cette étude invite le voyageur au sein du débat comme acteur du processus de décision. Objectifs. Investiguer les préférences des voyageurs à destination de pays à risque modéré à faible de malaria en matière de prévention contre la malaria, en mettant en perspective leur perception du risque et les raisons de leur choix. Méthodologie. Dans la salle d'attente du Centre de Vaccination et Médecine de Voyage, les voyageurs à destination de risque modéré à faible de malaria remplissent un questionnaire et choisissent la méthode de prévention qu'ils préfèrent aidés d'un tableau leur proposant 4 choix possible ; mesure de prévention des piqûres de moustique uniquement, chimioprophylaxie, traitement de réserve seul et traitement de réserve avec test diagnostic rapide. Ils reçoivent aussi une échelle de risque illustrant les risques de malaria et d'effets indésirables des anti-malariques comparés à différents autres risques liés au voyage, inspirée par les palettes de Paling de la Communication Risk Institut. Résultats. De décembre 2012 à décembre 2013, 391 voyageurs on été inclus. 59 (15%) ont choisi la chimioprophylaxie, 116 (30%) un traitement de réserve, 112 (29%) un traitement de réserve avec test rapide diagnostic, 100 (26%) une prévention des piqûre de moustiques uniquement, and 4 (1%) plusieurs alternatives. Les raisons de choisir une chimioprophylaxie étaient la sécurité (42%), l'action préventive (29%), l'efficacité (15%) et la facilité d'utilisation (15%). Les raisons de choisir un traitement de réserve étaient moins de prise de médicament (29%), moins d'effets secondaires de ceux-ci (23%) et le prix (9%). Les voyageurs choisissant la chimioprohylaxie l'avaient plus souvent déjà utilisée par le passé [OR=3.0 (CI 1.7-5.44)], sans différence en terme de profil démographique, caractéristique du voyage ou comportement à risque. Conclusions. Quand interrogés, 85% des voyageurs à destination de pays à risque modéré à faible de malaria préfèrent ne pas prendre la chimioprophylaxie, bien que la plupart des pays la recommande encore. Les raisons avancées sont cohérentes avec leur choix. Les nouvelles recommandations devraient prendre en compte la préférence des voyageurs et inclure un processus de décision partagé

Le tourisme des familles romandes composées d’un membre ayant une déficience intellectuelle: intérêt pour les vacances lointaines?

Le présent travail a deux objectifs : d’une part, il doit récolter des données sur les comportements, opinions, motivations et attentes touristiques du segment des familles avec un membre ayant une déficience intellectuelle, et d’autre part, il doit évaluer l’intérêt de ce marché de niche pour des centres de vacances adaptés dans des destinations lointaines. A cette fin, une enquête sous forme de questionnaire a été diffusée auprès des institutions et associations romandes en lien avec la déficience intellectuelle, ceux-là ayant pour mission de la transmettre aux parents. Les résultats de l’enquête ont permis d’identifier une inadéquation entre l’offre actuelle sur le marché romand dédié à ces familles et leurs attentes. Elle s’observe sur les plans du nombre d’offres disponibles, de la diversité des destinations et des formules proposées ainsi que sur les prix pratiqués. Elle démontre également un manque de connaissances concernant les prestataires touristiques par le groupe cible et vice-versa. L’enquête met en avant l’importance de proposer une structure de vacances adaptée à l’incapacité physique mais également un soutien professionnel sous la forme d’une prise en charge partielle du membre de la famille ayant une déficience intellectuelle sur le lieu de vacances. Les réponses apportées par l’enquête appuient donc la création de centres de vacances adaptés, en Europe comme dans les destinations lointaines

Exploration of the influence of different biomimetic designs of 3D printed multi-material artificial spinal disc on the natural mechanics restoration

One of the great challenges of artificial spinal disc (ASD) design lies in the reproduction of the complex mechanics of an intervertebral disc (IVD) that is characterized by a viscoelastic, nonlinear, and anisotropic behavior. Although the development of multi-material additive manufacturing (AM) combined with biomimetic design provide new opportunities for the realization of ASDs with complex behavior, the influence of different biomimetic designs on the kinematics of ASD in conjunction with AM is not yet explored. Therefore, this study proposes and fabricates four types of biomimetic, multi-material ASD designs based on mimicking either the material stiffness gradient or the structure found in a natural IVD. The results show that all the designs exhibit a desired viscoelastic behavior, while the ASD design based on a chainmail-like structure exhibits a nature-mimicking nonlinear rotational load response. In terms of restoring the natural trend of IVD’s anisotropic behavior, the ASD design that mimics the structure in an IVD outperforms the design that solely mimics the IVD’s material stiffness gradient. Additionally, all the designs proposed in this study show comparable instant helical axis (IHA) and instant center of rotation (ICOR) to an IVD regarding their location and moving direction

Las promesas y los escollos del ecoturismo, patrones de una revisión bibliográfica

Ecotourism theoretically consists of responsible travel to natural areas that confers environmental and social benefits. Despite those positive aims, there has been a scholar emphasis on the uneven results of ecotourism development, highlighting the gaps between its promised and observed outcomes. A growing number of academics assigns those failures to the capitalist nature of ecotourism and its role in sustaining neoliberalism expansion. They are calling for more research on this relationship, which this study is concerned with. The aim of the present paper is to understand and identify mechanisms preventing a fair and even application of ecotourism principles. In order to do so, case studies issued from the literature review have been selected and a cross-case study search for pattern methodology has been conducted, helping to assess ecotourism development in different contexts and scales as to identify common obstacles to the achievement of positive outcomes. According to the results, patterns of ecotourism implementation are intertwined with neoliberal policies and practices and follow three main mechanisms: 1) extension of neoliberal governance to the detriment of local population self-determination, 2) modification of local culture towards market-driven logics and 3) increased neoliberalization of nature under the form of commodification. In turn, those mechanisms ensue the studied negative social, political and environmental effects. To reduce those, locals should be empowered towards the decision to enter ecotourism and the way to conduct it, excluding dependency on external actors to avoid neoliberal hegemony.El ecoturismo teóricamente es aquel turismo en que el viaje se realiza de forma responsable a áreas naturales, lo que puede producir beneficios ambientales y sociales donde se realiza la actividad. Sin embargo, desde el ámbito académico se han realizado múltiples investigaciones que cuestionan esos supuestos beneficios y señalan los desiguales resultados asociados al ecoturismo. En ese sentido, dichos trabajos destacan la brecha existente entre unos resultados prometidos por el ecoturismo y los concretos resultantes de los proyectos ecoturísticos. Un número creciente de autores achaca dicha brecha a la naturaleza capitalista del ecoturismo y a su papel en el sostenimiento de la expansión del neoliberalismo. Es por ello que desde la academia se reclama más investigación sobre esta relación. Así, el objetivo de esta investigación es precisamente arrojar algo de luz sobre este tema, para lo que es necesario comprender e identificar los mecanismos que impiden la aplicación justa y equitativa de los principios del ecoturismo. Para ello, se lleva a cabo un estudio de diversos casos de estudio extraídos de la revisión bibliográfica, lo que permite evaluar y valorar el desarrollo ecoturístico en diferentes contextos y escalas, así como identificar obstáculos comunes. Los resultados confirman que parte de los impactos negativos derivados del desarrollo ecoturístico se deben a su vinculación con las políticas y prácticas neoliberales, con el desencadenamiento de los siguientes mecanismos: 1) extensión de la gobernanza neoliberal en detrimento de la autodeterminación de las comunidades locales, 2) modificación de la cultura local hacia lógicas de mercado y 3) la neoliberalización de la naturaleza bajo la forma de mercancía. Estos mecanismos a su vez, dan lugar a efectos sociales, políticos y ambientales negativos. Para reducir tales efectos, la población local debería empoderarse y ser capaz de decidir sobre la implantación o no del ecoturismo, excluyendo la dependencia respecto de los actores externos para evitar la hegemonía neoliberal

Sideband Injection Locking in Microresonator Frequency Combs

Frequency combs from continuous-wave-driven Kerr-nonlinear microresonators have evolved into a key photonic technology with applications from optical communication to precision spectroscopy. Essential to many of these applications is the control of the comb's defining parameters, i.e., carrier-envelope offset frequency and repetition rate. An elegant and all-optical approach to controlling both degrees of freedom is the suitable injection of a secondary continuous-wave laser into the resonator onto which one of the comb lines locks. Here, we study experimentally such sideband injection locking in microresonator soliton combs across a wide optical bandwidth and derive analytic scaling laws for the locking range and repetition rate control. As an application example, we demonstrate optical frequency division and repetition rate phase-noise reduction to three orders of magnitude below the noise of a free-running system. The presented results can guide the design of sideband injection-locked, parametrically generated frequency combs with opportunities for low-noise microwave generation, compact optical clocks with simplified locking schemes and more generally, all-optically stabilized frequency combs from Kerr-nonlinear resonators.Comment: 13 pages, 6 figure

Influence of aging on mechanical properties of the femoral neck using an inverse method.

Today, we are facing rapid aging of the world population, which increases the incidence of hip fractures. The gold standard of bone strength assessment in the laboratory is micro-computed finite element analysis (μFEA) based on micro-computed tomography (μCT) images. In clinics, the standard method to assess bone fracture risk is based on areal bone mineral density (aBMD), measured by dual-energy X-ray absorptiometry (DXA). In addition, homogenized finite element analysis (hFEA) constructed from quantitative computed tomography reconstructions (QCT) predicts clinical bone strength more accurately than DXA. Despite considerable evidence of degradation of bone material properties with age, in the past fifty years of finite element analysis to predict bone strength, bone material parameters remained independent of age. This study aims to assess the influence of age on apparent modulus, yield stress, and strength predictions of the human femoral neck made by laboratory-available bone volume fraction (BV/TV) and μFEA; and by clinically available DXA and hFEA. Using an inverse method, we test the hypothesis that FEA material parameters are independent of age. Eighty-six human femora were scanned with DXA (aBMD) and with QCT. The femoral necks were extracted and scanned at 16 μm resolution with μCT. The grayscale images were downscaled to 32 μm and 65 μm for linear and non-linear analyses, respectively, and segmented. The μFE solver ParOSolNL (non-linear) and a standard hFEA method were applied to the neck sections with the same material properties for all samples to compute apparent modulus, yield stress, and strength. Laboratory-available BV/TV was a good predictor of apparent modulus (R2 = 0.76), almost as good as μFEA (R2 = 0.79). However, yield stress and strength were better predicted by μFEA (R2 = 0.92, R2 = 0.86, resp.) than BV/TV (R2 = 0.76, R2 = 0.76, resp.). For clinically available variables, prediction of apparent modulus was better with hFEA than aBMD (R2 = 0.67, R2 = 0.58, resp.). hFEA outperformed aBMD for predictions of yield stress (R2 = 0.63 vs R2 = 0.34 for female and R2 = 0.55 for male) and strength (R2 = 0.48 vs R2 = 0.33 for female and R2 = 0.15 for male). The inclusion of age did not improve the multiple linear models for apparent modulus, yield stress, and strength. The resolution of the μFE meshes seems to account for most morphological changes induced by aging. The errors between the simulation and the experiment for apparent modulus, yield stress, and strength were age-independent, suggesting no rationale for correcting tissue material parameters in the current FE analysis of the aging femoral neck

Distance mapping in three-dimensional virtual surgical planning in hand, wrist and forearm surgery: a tool to avoid mistakes.

PURPOSE Three-dimensional planning in corrective surgeries in the hand and wrist has become popular throughout the last 20 years. Imaging technologies and software have improved since their first description in the late 1980s. New imaging technologies, such as distance mapping (DM), improve the safety of virtual surgical planning (VSP) and help to avoid mistakes. We describe the effective use of DM in two representative and frequently performed surgical interventions (radius malunion and scaphoid pseudoarthrosis). METHODS We simulated surgical intervention in both cases using DM. Joint spaces were quantitatively and qualitatively displayed in a colour-coded fashion, which allowed the estimation of cartilage thickness and joint space congruency. These parameters are presented in the virtual surgical planning pre- and postoperatively as well as in the actual situation in our cases. RESULTS DM had a high impact on the VSP, especially in radius corrective osteotomy, where we changed the surgical plan due to the visualization of the planned postoperative situation. The actual postoperative situation was also documented using DM, which allowed for comparison of the VSP and the achieved postoperative situation. Both patients were successfully treated, and bone healing and clinical improvement were achieved. CONCLUSION The use of colour-coded static or dynamic distance mapping is useful for virtual surgical planning of corrective osteotomies of the hand, wrist and forearm. It also allows confirmation of the correct patient treatment and assessment of the follow-up radiological documentation