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

Parents' knowledge and behaviour concerning sunning their babies; a cross-sectional, descriptive study

BACKGROUND: For centuries, sunlight has been used for therapeutic purposes. Parents still sun their infants to treat neonatal jaundice, nappy rash or mostly to supply vitamin D for bone development as a consequence of health beliefs. In this study we aimed to assess knowledge and behaviour of parents about benefits of sunlight and sun protection. METHODS: In this study, parents attending to governmental primary healthcare units for their children's routine vaccinations, upon their informed consent, were consecutively enrolled during one month. Data were collected by a semi-structured questionnaire. RESULTS: The mean age of 118 enrolled parents and their babies were 27.9 ± 6.5 years and 8.3 ± 5.8 months, respectively. Most of the participants were mothers (93.2%), housewives (81.4%) with an educational level of ≥6 years (71.2%). Sunlight was considered beneficial for bone development (86.4%), diaper rash (5.9%) and neonatal jaundice (12.7%). In case of neonatal jaundice 72.0% of the participants reported that they would consult a physician. Most of the participants (82.2%) were sunning their babies outdoors. Nearly half (49.7%) of them got this information from medical staff. Fifty two percent of the parents were sunning their babies before 10–11 a.m. and/or after 3 p.m. Only 13.6% of parents reported using sunscreen for their babies, and the majority of them were using sun protecting factor ≥ 15. One forth of the sunscreen users was using sunscreen according to their physicians' advice. CONCLUSION: Most of the participants were aware of the benefits of sunlight; especially for bone development. However they were displaying inappropriate behaviour while sunning their babies for health reasons. More education should be given to parents about the danger of sunlight at primary health care units while advising to sun their babies, if any

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