Estimating the effective degrees of freedom in univariate multiple regression analysis

The general linear model provides the most widely applied statistical framework for analyzing functional MRI (fMRI) data. With the increasing temporal resolution of recent scanning protocols, and more elaborate data preprocessing schemes, data independency is no longer a valid assumption. In this paper, we revise the statistical background of the general linear model in the presence of temporal autocorrelations. First, when detecting the activation signal, we explicitly account for the temporal autocorrelation structure, which yields a generalized F-test and the associated corrected (or effective) degrees of freedom (DOF). The proposed approach is data driven and thus independent of any specific preprocessing method. Then, for event-related protocols, we propose a new model for the temporal autocorrelations (“damped oscillator” model) and compare this model to another, previously used in the field (first-order autoregressive model, or AR(1) model). In the case of long fMRI time series, an efficient approximation for the number of effective DOF is provided for both models. Finally, the validity of our approach is assessed using simulated and real fMRI data and is compared with more conventional methods

Research Paper Polyclonal antibodies production against Staphylococcus aureus protein A: ELISA technique optimization for milk quality control

The main aim of this project is to produce polyclonal antibodies directed against the Staphylococcus aureus protein A and their use to appreciate bacteriological analysis of milk quality. In this context, an immunization produce was set up to test and detect in a batch of animals the convenient responder to the injected antigen. Furthermore, to optimize all parameters of retained ELISA test, a cross-table was conceived by using various concentrations of different reagents and has allowed selecting the optimaldilutions as follows: 1) 1/1000 for anti-Staphylococcus aureus protein A mouse antibodies and 1/2000 for anti-Staphylococcus aureus protein A rabbit antibodies. 2) 1/4000 for anti-Staphylococcus aureus treated by heat mouse antibodies and 1/500 for anti-Staphylococcus aureus protein A rabbit antibodies. 3) 1/2000 for anti-Staphylococcus aureus treated by NaClO mouse antibodies and 1/500 for anti-Staphylococcus aureus protein A rabbit antibodies. The application of optimized ELISA test to searchand detect Staphylococcus aureus germs in different samples of milk has shown very satisfying results when compared to those obtained by bacteriological method. Indeed, the sensitiveness and the reproducibility, as well as the possibility to analyze a great number of samples in the same time at a reduced manner make the immunochemical method a best choice of test able to replace recent bacteriological methods

Deflection angle and Shadows by Black Holes in Starobinsky-Bel-Robinson Gravity from M-theory

Motivated by M-theory compactifications, we investigate optical properties of black holes in the Starobinsky-Bel-Robinsion gravity. Precisely, we study the shadows and the deflection angle of light rays by non-rotating and rotating black holes in such a novel gravity. We start by discussing the shadows of the Schwarzschild-type solutions. As expected, we obtain perfect circular shadows where the size decreases with a stringy gravity parameter denoted by $\beta$. We show that this parameter is constrained by the shadow existence. Combining the Newman-Janis algorithm and the Hamilton-Jacobi mechanism, we examine the shadow behaviors of the rotating solutions in terms of one-dimensional real curves. Essentially, we find various sizes and shapes depending on the rotating parameter and the stringy gravity parameter $a$ and $\beta$, respectively. To inspect the shadow geometric deformations, we investigate the astronomical observables and the energy emission rate. As envisaged, we reveal that $a$ and $\beta$ have an impact on such shadow behaviors. For specific values of $a$, we remark that the obtained shadow shapes share certain similarities with the ones of the Kerr black holes in plasma backgrounds. Using the Event Horizon Telescope observational data, we provide predictions for the stringy gravity parameter $\beta$ which could play a relevant role in M-theory compactifications. We finish this work by a discussion on the behaviors of the light rays near to such four dimensional black holes by computing the deflection angle in terms of a required moduli space.Comment: Latex, 27 pages, 10 figures. Authors in alphabetical orde

Light Deflection by Rotating Regular Black Holes with a Cosmological Constant

Using the Gauss-Bonnet theorem, we compute and examine the deflection angle of light rays by rotating regular black holes with a cosmological constant. By the help of optical geometries, we first deal with the Hayward black holes with cosmological contributions. Then, we reconsider the study of the Bardeen solutions. We inspect the cosmological constant effect on the deflection angle of light rays. Concretely, we find extra cosmological correction terms generalizing certain obtained findings. Using graphical analysis, we provide a comparative discussion with respect to the Kerr solutions. The results confirm that the non-linear electrodynamic charges affect the space-time geometry by decreasing the deflection angle of light rays by such cosmological black holes.Comment: latex, 16 pages, 4 figures. Accepted for publication in Chin. J. Phys 202

Les kystes dermoïdes de la fosse cerebrale postereure

Matériel et Méthode 3 enfants âgés de 18 mois à 8 ans ont été colligés au service entre 2005 et 2010. Résultas 3 patients ont présenté un syndrome d’hypertension intracrânienne, dont un patient a présenté une méningite récidivante. Tous avaient un sinus dermique. L’IRM a été réalisée dans tous les cas. Tous ont bénéficié d’une exérèse chirurgicale totale et d’une dérivation du LCR par ventriculo-cisternostomie première en urgence dans un cas et par dérivation ventriculo-péritonéale en post-opératoire dans deux cas. L’évolution était satisfaisante sans récidive avec un recul moyen de 3 ans. Conclusion Dans notre série, le KD de la fosse cérébrale postérieure est toujours associé à un sinus dermique et à une hydrocéphalie. La prise en charge repose sur l’exérèse chirurgicale et sur la dérivation du liquide cérébro-spinal.Mots clés : kyste dermoïde, sinus dermique, fosse cérébrale postérieure, chirurgie, résonance magnétiqu

Retrospective study of epidemiological, clinicopathological and biological profils of 62 colorectal cancers cases in Jijel provence (Algeria)

In Algeria, the CRC wing and become the first digestive cancer in both sexes,  outperforming stomach cancer. To enrich the Algerian cancer registries, we analyzed the profiles of patients with these cancers in Jijel Willaya. This was a retrospective and descriptive analysis of epidemiological, clinicopathological and biological profiles of 62 CRC cases. We found that the CRC represented the first type of digestive cancers in which the three quarters were colon cancers. The most affected age group was 60-70 years with a male predominance and an average age of 56.20 years. The bleeding and abdominal pain were the majority telltale signs. The combined chemotherapy has been standardized with all patients and the Lieberkühnien adenocarcinoma was the major histological form. The disease issue and the choice of therapy depended on the K-RAS gene mutations. Our results were often compatible with the available literature and may provide reliable and relevant data on this disease.Key words: Colorectal cancer; Epidemiology; Therapy; Adenocarcinoma; K-RAS gen

Optical properties of an ensemble of G-centers in silicon

We addressed the carrier dynamics in so-called G-centers in silicon (consisting of substitutional-interstitial carbon pairs interacting with interstitial silicons) obtained via ion implantation into a silicon-on-insulator wafer. For this point defect in silicon emitting in the telecommunication wavelength range, we unravel the recombination dynamics by time-resolved photoluminescence spectroscopy. More specifically, we performed detailed photoluminescence experiments as a function of excitation energy, incident power, irradiation fluence and temperature in order to study the impact of radiative and non-radiative recombination channels on the spectrum, yield and lifetime of G-centers. The sharp line emitting at 969 meV ($\sim$1280 nm) and the broad asymmetric sideband developing at lower energy share the same recombination dynamics as shown by time-resolved experiments performed selectively on each spectral component. This feature accounts for the common origin of the two emission bands which are unambiguously attributed to the zero-phonon line and to the corresponding phonon sideband. In the framework of the Huang-Rhys theory with non-perturbative calculations, we reach an estimation of 1.6$\pm$0.1 \angstrom for the spatial extension of the electronic wave function in the G-center. The radiative recombination time measured at low temperature lies in the 6 ns-range. The estimation of both radiative and non-radiative recombination rates as a function of temperature further demonstrate a constant radiative lifetime. Finally, although G-centers are shallow levels in silicon, we find a value of the Debye-Waller factor comparable to deep levels in wide-bandgap materials. Our results point out the potential of G-centers as a solid-state light source to be integrated into opto-electronic devices within a common silicon platform