A parametric level-set method for partially discrete tomography

This paper introduces a parametric level-set method for tomographic reconstruction of partially discrete images. Such images consist of a continuously varying background and an anomaly with a constant (known) grey-value. We represent the geometry of the anomaly using a level-set function, which we represent using radial basis functions. We pose the reconstruction problem as a bi-level optimization problem in terms of the background and coefficients for the level-set function. To constrain the background reconstruction we impose smoothness through Tikhonov regularization. The bi-level optimization problem is solved in an alternating fashion; in each iteration we first reconstruct the background and consequently update the level-set function. We test our method on numerical phantoms and show that we can successfully reconstruct the geometry of the anomaly, even from limited data. On these phantoms, our method outperforms Total Variation reconstruction, DART and P-DART.Comment: Paper submitted to 20th International Conference on Discrete Geometry for Computer Imager

Social Enterprise in Europe: At the Crossroads of Market, Public Policies and Third Sector

Peer reviewe

Identification of the Biotransformation Products of 2-Ethylhexyl 4-(N,N-Dimethylamino)benzoate

Nowadays, 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP) is one of the most widely used UV filters in sunscreen cosmetics and other cosmetic products. However, undesirable processes such as percutaneous absorption and biological activity have been attributed to this compound. The in vitro metabolism of EDP was elucidated in the present work. First of all, the phase I biotransformation was studied in rat liver microsomes and two metabolites, N,N-dimethyl-p-aminobenzoic acid (DMP) and N-monomethyl-p-aminobenzoic acid (MMP), were identified by GC-MS analysis. Secondly, the phase II metabolism was investigated by means of LC-MS. The investigated reactions were acetylation and glucuronidation working with rat liver cytosol and with both human and rat liver microsomes, respectively. Analogue studies with p-aminobenzoic acid (PABA) were carried out in order to compare the well established metabolic pathway of PABA with the unknown biotransformation of EDP. In addition, a method for the determination of EDP and its two phase I metabolites in human urine was developed. The methodology requires a solid-phase extraction prior to LC-MS analysis. The method is based on standard addition quantification and has been fully validated. The repeatability of the method, expressed as relative standard deviation, was in the range 3.4–7.4% and the limit of detection for all quantified analytes was in the low ng mL−1 range

European Lung Cancer Working Party Clinical Practice Guidelines. Small Cell Lung Cnacer: IV. Limited disease

The present guidelines on the management of limited disease small cell lung cancer (SCLC) were formulated by the ELCWP in April 2007. They are designed to answer the following seven questions: 1) What is the definition of limited disease? 2) Should chest radiotherapy be provided and what are the benefits? 3) What is the optimal timing and mode of administration of chest irradiation? 4) Which are the optimal radiotherapy parameters: dose, fractionation, target volume? 5) What is the optimal chemotherapy regimen for limited disease SCLC? 6) Should prophylactic cranial irradiation be provided, when and for which patients? 7) What is the additional role of thoracic surgery in early SCLC

European Lung Cancer Working Party. Clinical Practice Guidelines. Small Cell Lung Cancer: V. Extensive disease

The present guidelines on the management of extensive disease small cell lung cancer (SCLC) were formulated by the ELCWP in October 2007. They are designed to answer the following nine questions: 1) What is the definition of extensive disease? 2)What are the active drugs? 3) What is the best induction regimen? 4) Is there a role for maintenance chemotherapy? 5) Is there a role for dose-intensive chemotherapy? 6) Is there a role for the use of haemopoietic growth factors and stem cells support? 7) Is there a role for alternating or sequential chemotherapy? 8) Is there a role for biological treatments? 9) Is there a place for second-line chemotherapy

Brazilian Consensus on Photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of nonmelanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection