The GRB luminosity function in the internal shock model confronted to observations

We compute the expected luminosity function of GRBs in the context of the internal shock model. We assume that GRB central engines generate relativistic outflows characterized by the respective distributions of injected kinetic power Edot and contrast in Lorentz factor Kappa = Gamma_max/Gamma_min. We find that if the distribution of contrast extends down to values close to unity (i.e. if both highly variable and smooth outflows can exist) the luminosity function has two branches. At high luminosity it follows the distribution of Edot while at low luminosity it is close to a power law of slope -0.5. We then examine if existing data can constrain the luminosity function. Using the log N - log P curve, the Ep distribution of bright BATSE bursts and the XRF/GRB ratio obtained by HETE2 we show that single and broken power-laws can provide equally good fits of these data. Present observations are therefore unable to favor one form of the other. However when a broken power-law is adopted they clearly indicate a low luminosity slope ~ -0.6 +- 0.2, compatible with the prediction of the internal shock model.Comment: 9 pages, 5 figure

Data acquisition, parameter extraction and characterization of active components using integrated instrumentation system

A data acquisition, parameter extraction and characterization system for electronic active components is presented in this paper. High sensitivity measuring equipments were used for data acquisition and effective extraction models based on optimization techniques developed to obtain the parameters of p-n junction diodes, Schottky diodes, field effect transistors and bipolar junction transistors. The performance of the developed extraction techniques are apparent via comparing experimental data with Spice simulated data using the model parameter that is graphically extracted and also those extracted using optimization techniques. The performance of the developed extraction techniques has been demonstrated by comparing the experimental characteristics with Spice simulated curves using default parameters and model parameters extracted using graphical and optimization techniques. The relative excursions of the simulated I-V characteristics of most investigated devices were less than 2.5 % with respect to the experimental curves, which shows the accuracy and effectiveness of the developed system. A number of software routines have also been implemented under Matlab environment to extract the Spice model parameters for different electronic devices

Recognizing faces in news photographs on the web

We propose a graph based method in order to recognize the faces that appear on the web using a small training set. First, relevant pictures of the desired people are collected by querying the name in a text based search engine in order to construct the data set. Then, detected faces in these photographs are represented using SIFT features extracted from facial features. The similarities of faces are represented in a graph which is then used in random walk with restart algorithm to provide links between faces. Those links are used for recognition by using two different methods. © 2009 IEEE

Angiodysplasies des maxillaires de l’enfant

Les angiodysplasies des maxillaires sont des affections rares et graves. Leur mauvais pronostic est surtout lié aux complications hémorragiques redoutables, dues le plus souvent à des extractions dentaires abusives sans examens radiologiques préalables. L’angio-IRM a permis d’une manière non invasive une meilleure connaissance de ces lésions en étudiant leur angio-architecture et leur hémodynamique. Jadis, le seul traitement efficace consistait en une exérèse chirurgicale mutilante entraînant des complications esthétiques et fonctionnelles sévères avec une morbidité importante. Actuellement, la radiologie interventionnelle a révolutionné la prise en charge grâce à l’artériographie hypersélective et àla découverte de nouveaux matériaux d’obturation plus faciles à manier. L’embolisation hypersélective est devenue l’arme de première intention en raison de son caractère conservateur et de son faible taux de  complications. Le but de ce travail est de rappeler les différents aspects étiopathogéniques, cliniques et para cliniques des angiodysplasieset de définir l’attitude thérapeutique.Mots clefs : angiodysplasie, embolisation, chirurgie

Does biological maturity actually confound gender-related differences in physical activity in preadolescence?

Aim To examine: (i) if maturity-related gender differences in moderate-to-vigorous physical activity (MVPA) depend on how maturity status is defined and measured; and (ii) the influence of maturity level on compliance with PA recommendations. Methods The study involved 253 children (139 boys) aged 9.9 ± 0.9 years, with mean stature and weight of 1.39 ± 0.08 m and 35.8 ± 8.8 kg respectively. Their PA was evaluated using an Actigraph accelerometer (Model 7164). Maturity was assessed using the estimated age at peak height velocity (APHV) and a standardized APHV by gender (i.e. centred APHV). Results Boys engaged in significantly more MVPA than girls (P < 0.0001). There was a significant correlation between the centred APHV and MVPA in boys (r = 0.20; P = 0.016), but not in girls (r = 0.13; P = 0.155). An ancova controlling for the estimated APHV showed no significant interactions between gender and APHV, and the main effect of gender on MVPA was negated. Conversely, there was a significant main effect of APHV on MVPA (F 1,249 = 6.12; P = 0.014; η p 2 = 0.024). Only 9.1% of children met the PA recommendations, including 14.4% of boys and 2.6% of girls (P < 0.01). This observation also applies in both pre-APHV (12.7% of boys vs. 2.4% of girls, P < 0.001) and post-APHV children (23.8% of boys vs. 3.4% of girls, P < 0.0001). No differences in PA guidelines were observed between pre-APHV and post-APHV children. Conclusions Among prepubescent children, the influence of biological maturity on gender differences in PA may be a function of how maturity status is determined. The most physically active prepubescent children were those who were on time according to APHV

Re-ranking of web image search results using a graph algorithm

We propose a method to improve the results of image search engines on the Internet to satisfy users who desire to see relevant images in the first few pages. The method re-ranks the results of text based systems by incorporating visual similarity of the resulting images. We observe that, together with many unrelated ones, results of text based systems include a subset of correct images, and this set is, in general, the largest one which has the most similar images compared to other possible subsets. Based on this observation, we present similarities of all images in a graph structure, and find the densest component that corresponds to the largest set of most similar subset of images. Then, to re-rank the results, we give higher priority to the images in the densest component, and rank the others based on their similarities to the images in the densest component. The experiments are carried out on 18 category of images from [8]. © 2008 IEEE

Experimental-numerical characterization of the fracture behaviour of P264GH steel notched pipes subject to internal pressure

The rupture phenomenon of a mechanical structure requires critical consideration, because of its safety constructions. A detailed experiment of material features as well as the Young’s modulus, yield strength, material toughness or fracture resistance provides useful information to predict the life integrity of a pipe structure. This paper presents the most accurate experimental techniques for characterization of a pipe-like structure to assess its reliability. Standard traction tests, dynamic Charpy tests and pressure tests were performed to envisage the crack propagation progress. Detailed information on fracture process was obtained by a robust numerical approach using the finite element method

Tag suggestr: Automatic photo tag expansion using visual information for photo sharing websites

In this paper, we propose an automatic photo tag expansion system for the community photo collections, such as Flickr. Our aim is to suggest relevant tags for a target photograph uploaded to the system by a user, by incorporating the visual and textual cues from other related photographs. As the first step, the system requires the user to add only a few initial tags for each uploaded photo. These initial tags are used to retrieve related photos including the same tags in their tag lists. Then the set of candidate tags collected from a large pool of photos is weighted according to the similarity of the target photo to the retrieved photo including the tag. Finally, the tags in the highest rankings are used to automatically expand the tags of the target photo. The experimental results on Flickr photos show that, the use of visual similarity of semantically relevant photos to recommend tags improves the quality of suggested tags compared to only text-based systems. © 2008 Springer Berlin Heidelberg

Ovulation rate and early embryonic survival rate in female rabbits of a synthetic line and a local Algerian population

[EN] A higher litter size at birth has been reported in female rabbits from a Synthetic line than in those of the Local Algerian population. The aim of this work was to analyse whether this difference in litter size was due to a higher ovulation rate and/or embryonic survival rate in Synthetic line than in Local Algerian population. In total, 24 multiparous female rabbits from Synthetic line and 23 from Local population were used in this experiment. Litter size at birth was recorded up to the first 3 parities. Litter size was 20% higher in Synthetic line than Local population. At their 4th gestation, the females were euthanized at 72 h post coitum. Synthetic line females had 50% more ova and embryos than those of Local population (+4.42 ova and +3.92 embryos, respectively). Synthetic line displayed a lower percentage of normal embryos and a larger number of unfertilized oocytes than Local population (–2.81% and +0.64 oocytes, respectively), but differences were not relevant. Synthetic line showed a lesser embryonic stage of development at 72 h post coitum, showing a higher percentage of early morulae (31.50 vs. 8.50%) and a lower percentage of compact morulae (51.45 vs. 78.65%) than Local population. No relevant difference was found for early embryonic survival rate between Synthetic line and Local population. In conclusion, the difference in litter size was mainly due to a higher ovulation rate in the Synthetic line, allowing more embryos to develop in this line.Belabbas, R.; García, M.; Ainbaziz, H.; Berbar, A.; Zitouni, G.; Lafri, M.; Bouzouan, M.... (2016). Ovulation rate and early embryonic survival rate in female rabbits of a synthetic line and a local Algerian population. World Rabbit Science. 24(4):275-282. doi:10.4995/wrs.2016.5301.SWORD275282244Argente, M. J., Santacreu, M. A., Climent, A., & Blasco, A. (2003). Relationships between uterine and fetal traits in rabbits selected on uterine capacity1. Journal of Animal Science, 81(5), 1265-1273. doi:10.2527/2003.8151265xBelabbas R., AinBaziz H., Ilès I., Zenia S., Boumahdi Z., Boulbina I., Temim S. 2011. Study of prolificacy and its main biological components in rabbits of local Algerian population (Oryctolagus cuniculus). Livest. Res. Rur. Dev., 23: 61.Brun J.M., Baselga M. 2004. Analysis of reproductive performances during the formation of a rabbit synthetic strain. In Proc.: 8th World Rabbit Congress, September 7-10, 2004, Puebla, Mexico, 32-37.Bolet, G., & Theau-Clément, M. (1994). Fertilisation rate and preimplantation embryonic development in two rabbit strains of different fecundity, in purebreeding and crossbreeding. Animal Reproduction Science, 36(1-2), 153-162. doi:10.1016/0378-4320(94)90062-0Buhi, W. C., & Alvarez, I. M. (2003). Identification, characterization and localization of three proteins expressed by the porcine oviduct. Theriogenology, 60(2), 225-238. doi:10.1016/s0093-691x(03)00027-xGacem M., Lebas F. 2000. Rabbit husbandry in Algeria. Technical structure and evaluation of performances. World Rabbit Sci., 8(Suppl. 1): B75-80.Gacem M., Zerrouki N., Lebas F., Bolet G., 2008. Strategy of developing rabbit meat in Algeria: creation and selection of a synthetic strain. In Proc.: 9th World Rabbit Congress, June 10-13, 2008, Verona, Italy, 85-89.Nancarrow C.D., Hill J.L. 1995. Oviduct proteins in fertilization and early embryo development. J. Reprod. Fertil., (Suppl) 49: 3-13.Salvetti P., Guérin P., Theau-Clément M., Hurtaud J., Beckers J.F., Joly T. 2007. Essais d'amélioration de la production d'embryons chez la lapine. In Proc.: 12èmes Journées de la Recherche Cunicole, 27-28 Novembre 2007, Le Mans, France, 41-44.Xie, S., Broermann, D. M., Nephew, K. P., Bishop, M. D., & Pope, W. F. (1990). Relationship between oocyte maturation and fertilization on zygotic diversity in swine. Journal of Animal Science, 68(7), 2027. doi:10.2527/1990.6872027xYoussef Y.K., Iraqi M.M., El-Raffa A.M., Afifi E.A., Khalil M.H., García M.L., Baselga M. 2008. A joint project to synthesize new lines of rabbits in Egypt and Saudi Arabia: emphasis for results and prospects. In Proc.: 9th World Rabbit Congress, June 10-13, 2008, Verona, Italy, 1637-1642

Climatic zone and soil properties determine the biodiversity of the soil bacterial communities associated to native plants from desert areas of north-central algeria

Algeria is the largest country in Africa characterized by semi-arid and arid sites, located in the North, and hypersaline zones in the center and South of the country. Several autochthonous plants are well known as medicinal plants, having in common tolerance to aridity, drought and salinity. In their natural environment, they live with a great amount of microbial species that altogether are indicated as plant microbiota, while the plants are now viewed as a \u201cholobiont\u201d. In this work, the microbiota of the soil associated to the roots of fourteen economically relevant autochthonous plants from Algeria have been characterized by an innovative metagenomic approach with a dual purpose: (i) to deepen the knowledge of the arid and semi-arid environment and (ii) to characterize the composition of bacterial communities associated with indigenous plants with a strong economic/commercial interest, in order to make possible the improvement of their cultivation. The results presented in this work highlighted specific signatures which are mainly determined by climatic zone and soil properties more than by the plant species