Collaborative filtering to quarterly index subjective well-being: case of Morocco

This paper presents the results of a study conducted in Morocco to measure happiness of its citizens based on data regrouped from four surveys. Each participant in these surveys is characterized by Sex, age group, region, place of residence, family situation, and profession. 380 participants answered 45 questions in each survey. In the case of missing data, a collaborative filtering approach was adopted to predict the missing answer from gathered answers by exploiting the similarity between participants according to their characteristics. The obtained results were analyzed using simple random analysis regarding each key variation under the main theory. Kruskal-Wallis test and Mann-Whitney test were conducted

A robust multi-frame super resolution based on curvature registration and second order variational regularization

International audienceMultiframe image super-resolution is a technique to obtain a high-resolution image by fusing a sequence of low-resolution ones. This paper deals with a new approach to robust super resolution based on regularization framework. Since registration is an important step that ensures the success of super resolution algorithms, must choose the most suitable method. We suggest a new algorithm specified at low resolution images with small deformations using fourth-order partial differential equations (PDE) regularization in the last step of super resolution. The deformations are not parametric and differs from one image to another. We use a curvature registration specially because image are slightly deformed. Experimental results show the robustness of the proposed method compared to classical super resolution methods

Ghrelin localization in the medulla of rat and human adrenal gland and in pheochromocytomas

Objective: Ghrelin is predominantly produced by neuroendocrine cells of stomach and has been expressed in several normal and tumour endocrine tissues. It has been reported that the localization of ghrelin is exclusively in the cortex of human and rat adrenal gland and in adrenocortical tumours. This prompted us to analyze the expression of this peptide in medulla of human and rat adrenal glands and in human pheochromocytomas. Design and methods: Analysis of ghrelin mRNA expression in rat adrenal gland was conducted by means of semi-quantitative RT-PCR. Ghrelin localization was studied in medulla of human and rat adrenal gland by immunohistochemistry. In addition, we have carried out a double immunofluorescence with chromogranin A to determine the specific cell type expressing ghrelin immunoreactivity. Ghrelin expression was also analyzed in five cases of pheochromocytoma by immunohistochemistry. Finally, Western blotting analysis was performed with goat ghrelin antibody in the cortex and in the medulla of rat adrenal gland. Results: RT-PCR demonstrated expression of ghrelin mRNA in rat adrenal gland. We also detected ghrelin expression in virtually all rat pheochromocytes by immunohistochemistry and double immunofluorescence. Furthermore, we showed ghrelin immunoreactivity in the medulla of human adrenal gland and in pheochromocytomas. By Western blotting, we found the expression of ghrelin precursor, proghrelin and mature ghrelin in the medulla of rat adrenals. However, the cortex of rat adrenal gland only expressed ghrelin precursor. Conclusions: Our study is the first to demonstrate a medullar expression of ghrelin in human and rat adrenal gland; we also showed ghrelin expression in pheochromocytomas