Imagerie cardiaque non invasive: apport spécifique en clinique des nouvelles modalités (I). Evaluation morphologique [Cardiac imaging: specific clinical role of newly developed non invasive techniques. Part 1: Morphological evaluation].

Echocardiography is the preferred initial test to assess cardiac morphology and ventricular function. Cardiac MRI enables an optimal visualisation of heart muscle without contrast injection, and precise measurement of the ventricular volumes and systolic function. It is therefore an ideal test for patients with poor echocardiographic windows or for the specific evaluation of right heart chambers. Heart CT also remarkably images heart muscle and precisely measures ventricular systolic function after intravenous injection of iodinated contrast. Coronary CT may also, in selected cases, avoid the need for diagnostic coronary angiography. Although very accurate, these imaging modalities are expensive and may be contra-indicated for a particular patient. Their use in clinical practice has to follow the accepted guidelines.

Modelling short-term ultraviolet exposure as an alternative to individual dosimetry

Background: Excessive exposure to solar Ultra-Violet (UV) light is the main cause of most skin cancers in humans. Factors such as the increase of solar irradiation at ground level (anthropic pollution), the rise in standard of living (vacation in sunny areas), and (mostly) the development of outdoor activities have contributed to increase exposure. Thus, unsurprisingly, incidence of skin cancers has increased over the last decades more than that of any other cancer. Melanoma is the most lethal cutaneous cancer, while cutaneous carcinomas are the most common cancer type worldwide. UV exposure depends on environmental as well as individual factors related to activity. The influence of individual factors on exposure among building workers was investigated in a previous study. Posture and orientation were found to account for at least 38% of the total variance of relative individual exposure. A high variance of short-term exposure was observed between different body locations, indicating the occurrence of intense, subacute exposures. It was also found that effective short-term exposure ranged between 0 and 200% of ambient irradiation, suggesting that ambient irradiation is a poor predictor of effective exposure. Various dosimetric techniques enable to assess individual effective exposure, but dosimetric measurements remain tedious and tend to be situation-specific. As a matter of facts, individual factors (exposure time, body posture and orientation in the sun) often limit the extrapolation of exposure results to similar activities conducted in other conditions. Objective: The research presented in this paper aims at developing and validating a predictive tool of effective individual exposure to solar UV. Methods: Existing computer graphic techniques (3D rendering) were adapted to reflect solar exposure conditions and calculate short-term anatomical doses. A numerical model, represented as a 3D triangular mesh, is used to represent the exposed body. The amount of solar energy received by each "triangle is calculated, taking into account irradiation intensity, incidence angle and possible shadowing from other body parts. The model take into account the three components of the solar irradiation (direct, diffuse and albedo) as well as the orientation and posture of the body. Field measurements were carried out using a forensic mannequin at the Payerne MeteoSwiss station. Short-term dosimetric measurements were performed in 7 anatomical locations for 5 body postures. Field results were compared to the model prediction obtained from the numerical model. Results: The best match between prediction and measurements was obtained for upper body parts such as shoulders (Ratio Modelled/Measured; Mean = 1.21, SD = 0.34) and neck (Mean = 0.81, SD = 0.32). Small curved body parts such as forehead (Mean = 6.48, SD = 9.61) exhibited a lower matching. The prediction is less accurate for complex postures such as kneeling (Mean = 4.13, SD = 8.38) compared to standing up (Mean = 0.85, SD = 0.48). The values obtained from the dosimeters and the ones computed from the model are globally consistent. Conclusion: Although further development and validation are required, these results suggest that effective exposure could be predicted for a given activity (work or leisure) in various ambient irradiation conditions. Using a generic modelling approach is of high interest in terms of implementation costs as well as predictive and retrospective capabilities.

Searching patterns in painting images with computer vision techniques

This paper presents a pattern recognition method focused on paintings images. The purpose is construct a system able to recognize authors or art styles based on common elements of his work (here called patterns). The method is based on comparing images that contain the same or similar patterns. It uses different computer vision techniques, like SIFT and SURF, to describe the patterns in descriptors, K-Means to classify and simplify these descriptors, and RANSAC to determine and detect good results. The method are good to find patterns of known images but not so good if they are not.

Building energy saving techniques and indoor air quality : a dilemma

In European countries and North America, people spend 80 to 90% of time inside buildings and thus breathe indoor air. In Switzerland, special attention has been devoted to the 16 stations of the national network of observation of atmospheric pollutants (NABEL). The results indicate a reduction in outdoor pollution over the last ten years. With such a decrease in pollution over these ten years the question becomes: how can we explain an increase of diseases? Indoor pollution can be the cause. Indoor contaminants that may create indoor air quality (IAQ) problems come from a variety of sources. These can include inadequate ventilation, temperature and humidity dysfunction, and volatile organic compounds (VOCs). The health effects from these contaminants are varied and can range from discomfort, irritation and respiratory diseases to cancer. Among such contaminants, environmental tobacco smoke (ETS) could be considered the most important in terms of both health effects and engineering controls of ventilation. To perform indoor pollution monitoring, several selected ETS tracers can be used including carbon monoxide (CO), carbon dioxide (CO2), respirable particles (RSP), condensate, nicotine, polycyclic aromatic hydrocarbons (PAHs), nitrosamines, etc. In this paper, some examples are presented of IAQ problems that have occurred following the renewal of buildings and energy saving concerns. Using industrial hygiene sampling techniques and focussing on selected priority pollutants used as tracers, various problems have been identified and solutions proposed. [Author]

Elevada prevalença d’hipovitaminosi D en pacients amb diabetis mellitus tipus 2: relació amb la ingesta de vitamina D i el temps d’exposició solar

Objectius: Estimar la prevalença del dèficit de VitD en pacients amb DM2; avaluar el compliment de les IDR per la VitD; valorar la influència d’aquest compliment i de l’exposició solar en la 25-OH-D3 i la PTHi. Mètodes: 70 pacients. Es va estimar l’exposició solar i la ingesta de VitD. Es van determinar paràmetres del metabolisme fosfo-càlcic i del control glucèmic. Resultats: El 95,8% presentaven hipovitaminosi D, i el 14,8% una PTHi elevada. La majoria no van assolir el compliment de les IDR. La 25-OH-D3 es va correlacionar amb la PTHi però no amb la ingesta de VitD ni l’exposició solar.

Robust fault detection using consistency techniques for uncertainty handling

Often practical performance of analytical redundancy for fault detection and diagnosis is decreased by uncertainties prevailing not only in the system model, but also in the measurements. In this paper, the problem of fault detection is stated as a constraint satisfaction problem over continuous domains with a big number of variables and constraints. This problem can be solved using modal interval analysis and consistency techniques. Consistency techniques are then shown to be particularly efficient to check the consistency of the analytical redundancy relations (ARRs), dealing with uncertain measurements and parameters. Through the work presented in this paper, it can be observed that consistency techniques can be used to increase the performance of a robust fault detection tool, which is based on interval arithmetic. The proposed method is illustrated using a nonlinear dynamic model of a hydraulic system

Constraint satisfaction techniques under uncertain conditions for fault diagnosis in nonlinear dynamic systems

The speed of fault isolation is crucial for the design and reconfiguration of fault tolerant control (FTC). In this paper the fault isolation problem is stated as a constraint satisfaction problem (CSP) and solved using constraint propagation techniques. The proposed method is based on constraint satisfaction techniques and uncertainty space refining of interval parameters. In comparison with other approaches based on adaptive observers, the major advantage of the presented method is that the isolation speed is fast even taking into account uncertainty in parameters, measurements and model errors and without the monotonicity assumption. In order to illustrate the proposed approach, a case study of a nonlinear dynamic system is presented

Traitement des tumeurs malignes du foie par radiologie interventionnelle: techniques ablatives [Interventional radiology procedures for malignancies of the liver: ablation procedures].

Percutaneous ablative procedures allow curative treatment of stage BCLC 0 or BCLC A hepatocellular carcinoma, as well as liver metastases of colorectal cancer. Several methods exist including radiofrequency ablation, the most commonly used. These techniques can be used in combination with surgical excision or alone if surgery is contraindicated. They are associated with significantly reduced mortality as compared to surgery.

Dialyse et écologie: est-il possible de faire mieux à l'avenir [Dialysis and ecology: can we do better in the future?].

Development of dialysis has saved the lives of many patients. However, haemodialysis and peritoneal dialysis are very demanding in resources such as water and electricity, and generate a large amount of waste. In this article, we will review the environmental aspects of dialysis. Different solutions will be discussed, such as recycling of water discharged during reverse osmosis, the integration of solar energy, recycling of waste plastics, and the use of other techniques such as sorbent dialysis. In a world where natural resources are precious and where global warming is a major problem, it is important that not only dialysis, but all branches of medicine become more attentive to ecology.

Iterative image reconstruction techniques: cardiothoracic computed tomography applications.

Iterative image reconstruction algorithms provide significant improvements over traditional filtered back projection in computed tomography (CT). Clinically available through recent advances in modern CT technology, iterative reconstruction enhances image quality through cyclical image calculation, suppressing image noise and artifacts, particularly blooming artifacts. The advantages of iterative reconstruction are apparent in traditionally challenging cases-for example, in obese patients, those with significant artery calcification, or those with coronary artery stents. In addition, as clinical use of CT has grown, so have concerns over ionizing radiation associated with CT examinations. Through noise reduction, iterative reconstruction has been shown to permit radiation dose reduction while preserving diagnostic image quality. This approach is becoming increasingly attractive as the routine use of CT for pediatric and repeated follow-up evaluation grows ever more common. Cardiovascular CT in particular, with its focus on detailed structural and functional analyses, stands to benefit greatly from the promising iterative solutions that are readily available.

Temporal variability and trends of the downward solar radiation over Europe during the 20th century, with regional focus in the dimming/brightening phenomena on the Iberian Peninsula

Proyecto de investigación elaborado a partir de una estancia en el Institute for Atmospheric and Climate Science, a Alemanya, entre 2010 y 2012. La radiación solar que alcanza la superficie terrestre es un factor clave entre los procesos que controlan el clima de la Tierra, dado el papel que desempeñan en el balance energético y el ciclo hidrológico. Establecer su contribución al cambio climático reciente supone una gran dificultad debido a la complejidad de los procesos implicados, la gran cantidad de información requerida, y la incertidumbre de las bases de datos disponibles en la actualidad. Así, el objetivo principal del proyecto ha consistido en generar una base de datos de insolación incluyendo las series más largas (desde finales del siglo XIX) disponibles en toda Europa. Esta base de datos complementa para nuestro continente el Global Energy Balance Archive (GEBA) que mantiene y gestiona el grupo que ha acogido al receptor de la ayuda postdoctoral, y permite extender espacial (especialmente en países del sur de Europa) y temporalmente las series climáticas disponibles de mediciones de irradiancia solar. Como la insolación es un proxy de la irradiancia solar, el proyecto actual también ha tratado de calibrar de forma exhaustiva ambas variables, a fin de generar una nueva base de datos reconstruida de esta segunda variable que esté disponible desde finales del siglo XIX en Europa. Un segundo objetivo del proyecto ha consistido en continuar trabajando a escala de mayor detalle sobre la Península Ibérica, con el fin de proporcionar una mejor comprensión del fenómeno del “global dimming/brightening” y su impacto en el ciclo hidrológico y balance energético. Finalmente, un tercer objetivo del presente proyecto postdoctoral ha consistido en continuar estudiando los posibles ciclos semanales a gran escala de diferentes variables climáticas, línea de investigación de interés para la detección de posibles efectos de los aerosoles antrópicos en el clima a escalas temporales breves, y consecuentemente estrechamente vinculado al fenómeno del “global dimming/brightening”.

Techniques d'évaluation de la force des muscles respiratoires. [Techniques for assessing respiratory muscle strength.]

La faiblesse des muscles respiratoires peut entraîner une dyspnée, un encombrement bronchique et une insuffisance respiratoire potentiellement fatale. L'évaluation de la force musculaire respiratoire s'impose donc dans les affections neuro-musculaires, mais également dans les situations de dyspnée inexpliquée par une première évaluation cardiaque et pulmonaire. À la spirométrie, une faiblesse musculaire est suspectée sur la base de la boucle débit-volume montrant un débit de pointe émoussé et une fin prématurée de l'expiration. Une diminution importante de la capacité vitale en position couchée suggère une paralysie diaphragmatique. La force inspiratoire est mesurée par la pression inspiratoire maximale (PImax) contre une quasi-occlusion des voies aériennes. Ce test relativement difficile est d'interprétation délicate en cas de collaboration insuffisante. La mesure de la pression nasale sniff (SNIP) est une alternative utile, car elle élimine le problème des fuites autour de l'embout buccal et la réalisation du reniflement est facile. De même, la pression trans-diaphragmatique sniff mesure la force du diaphragme au moyen de sondes oesophagienne et gastrique. En cas de collaboration insuffisante, on peut recourir à la stimulation magnétique des nerfs phréniques qui induit une contraction non-volontaire du diaphragme. La force expiratoire est mesurée par la pression expiratoire maximale (PEmax) contre une quasi-occlusion. La force disponible pour tousser est mesurée par la pression gastrique à la toux, ou plus simplement par le débit de pointe à la toux. Chez les patients à risque, la mesure de la force des muscles respiratoires permet d'instaurer à temps une assistance ventilatoire ou à la toux.

Passive modernization? the new human development index and its components in Italy’s regions (1871-2007)

The article presents and discusses estimates of social and economic indicators for Italy’s regions in benchmark years roughly from Unification to the present day: life expectancy, education, GDP per capita at purchasing power parity, and the new Human Development Index (HDI). A broad interpretative hypothesis, based on the distinction between passive and active modernization, is proposed to account for the evolution of regional imbalances over the long-run. In the lack of active modernization, Southern Italy converged thanks to passive modernization, i.e., State intervention: however, this was more effective in life expectancy, less successful in education, expensive and as a whole ineffective in GDP. As a consequence, convergence in the HDI occurred from the late XIX century to the 1970s, but came to a sudden halt in the last decades of the XX century.