32 research outputs found

    An engineering process for security patterns application in component based models

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    International audienceSecurity engineering with patterns is currently a very active area of research. Security patterns - an adaptation of Design Patterns to security - capture experts' experience in order to solve recurrent security problems in a structured and reusable way. In this paper, our objective is to describe an engineering process, called SCRIP (SeCurity patteRn Integration Process), which provides guidelines for integrating security patterns into component-based models. SCRIP defines activities and products to integrate security patterns in the whole development process, from UML component modeling until aspect code generation. The definition of SCRIP has been made using the OMG standard Software and System Process Engineering Meta-model (SPEM). We are developing a CASE tool to support that process

    TCP-Fluorapatite Composite Scaffolds: Mechanical Characterization and In Vitro/In Vivo Testing

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    In the present paper, we investigate the biological performance of the tricalcium phosphate ceramic (β-TCP) bone substitute combined with the fluorapatite (Fap). Porous biocomposites consisting of β-tricalcium phosphate (β-TCP) with 26.5% fluorapatite (Fap) were elaborated and characterized in order to evaluate its potential application in bone graft substitute. Bioactivity was determined with in vivo and in vitro tests by immersion of samples in simulated fluid body (SBF) for several periods of time. Clinical, radiological, and histological assessments were then carried out to evaluate the biological properties of developed β-TCP-26.5% Fap composites. An in vivo investigation revealed the biological properties of the prepared macroporous scaffolds, namely, biocompatibility, bioactivity, biodegradability, and osteoconductivity. The morphological characteristics, granule size, and chemical composition were indeed found to be favorable for osseous cell development. All histological observations of the preliminary in vivo study in the tibia of rabbits proved the biocompatibility and the resorption of the investigated bioceramic. In contrast, the implantation period will have to be optimized by further extensive animal experiments

    The Rubin's q-wavelet packets

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    Using the q-harmonic analysis associated with the q-Rubin operator, we study three types of q-wavelet packets and their corresponding q-wavelet transforms. We give for these wavelet transforms the related Plancherel and inversion formulas as well as their q-scale discrete scaling functions

    Dynamic modeling of spindle-rolling bearings systems in peripheral milling operations

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    In High-Speed Milling Process (HSM) the machining precision is directly affected by spindle bearing system which has a crucial role and it impacts directly the dynamic performance of the machining system. This study is about an accurate simulation of such system response. In fact, the Timoshenko beam theory with different circular sections is used to propose a finite element model of the spindle system. The effect of the rolling bearings and the gyroscopic moment at high speeds as well as the centrifugal forces and the cutting forces are considered in the formulation. The rigid and flexible movements of the spindle are taken into account. The dynamic responses of tool-tip under the dynamic cutting forces are numerically investigated

    Study of lipid profile and parieto-temporal lipid peroxidation in AlCl3 mediated neurotoxicity. modulatory effect of fenugreek seeds

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    <p>Abstract</p> <p>Background</p> <p>Peroxidation of lipid (LPO) membrane and cholesterol metabolism have been involved in the physiopathology of many diseases of aging brain. Therefore, this prospective animal study was carried firstly to find out the correlation between LPO in posterior brain and plasmatic cholesterol along with lipoprotein levels after chronic intoxication by aluminium chloride (AlCl<sub>3</sub>). Chronic aluminum-induced neurotoxicity has been in fact related to enhanced brain lipid peroxidation together with hypercholesterolemia and hypertriglyceridemia, despite its controversial etiological role in neurodegenerative diseases. Secondly an evaluation of the effectiveness of fenugreek seeds in alleviating the engendered toxicity through these biochemical parameters was made.</p> <p>Results</p> <p>Oral administration of AlCl<sub>3 </sub>to rats during 5 months (500 mg/kg bw i.g for one month then 1600 ppm via the drinking water) enhanced the levels of LPO in posterior brain, liver and plasma together with lactate dehydrogenase (LDH) activities, total cholesterol (TC), triglycerides (TG) and LDL-C (Low Density Lipoproteins) levels. All these parameters were decreased following fenugreek seeds supplementation either as fenugreek seed powder (FSP) or fenugreek seed extract (FSE). A notable significant correlation was observed between LPO<sub>brain </sub>and LDL-C on one hand and LDH<sub>liver </sub>on the other hand. This latter was found to correlate positively with TC, TG and LDL-C. Furthermore, high significant correlations were observed between LDH<sub>brain </sub>and TC, TG, LDL-C, LPO<sub>brain </sub>as well as LDH<sub>liver</sub>.</p> <p>Conclusion</p> <p>Aluminium-induced LPO in brain could arise from alteration of lipid metabolism particularly altered lipoprotein metabolism rather than a direct effect of cholesterol oxidation. Fenugreek seeds could play an anti-peroxidative role in brain which may be attributed in part to its modulatory effect on plasmatic lipid metabolism.</p

    HaptiSole: Wearable Haptic System in Vibrotactile Guidance Shoes for Visually Impaired Wayfinding

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    During the last decade, several Electronic Orientation Aids devices have been proposed to solve the autonomy problems of visually impaired people. When hearing is considered the primary sense for Visually Impaired people (VI) and it is generally loaded with the environment, the use of tactile sense can be considered a solution to transmit directional information. This paper presents a new wearable haptic system based on four motors implemented in shoes, while six directions can be played. This study aims to introduce an interface design and investigate an appropriate means of spatial information delivery through haptic sense. The first experiment of the proposed system was performed with 15 users in an indoor environment. The results showed that the users were able to recognize, with high accuracy, the directions displayed on their feet. The second experiment was conducted in an outdoor environment with five blindfolded users who were guided along 120 meters. The users, guided only by the haptic system, successfully reached their destinations. The potential of tactile-foot stimulation to help VI understand Electronic Orientation Aids (EOA) instructions was discussed, and future challenges were defined

    Phobia Exposure Therapy Using Virtual and Augmented Reality: A Systematic Review

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    A specific phobia is a common anxiety-related disorder that can be treated efficiently using different therapies including exposure therapy or cognitive therapy. One of the most famous methods to treat a specific phobia is exposure therapy. Exposure therapy involves exposing the target patient to the anxiety source or its context without the intention to cause any danger. One promising track of research lies in VR exposure therapy (VRET) and/or AR exposure therapy (ARET), where gradual exposure to a negative stimulus is used to reduce anxiety. In order to review existing works in this field, a systematic search was completed using the following databases: PubMed, ProQuest, Scopus, Web of Science, and Google Scholar. All studies that present VRET and/or ARET solutions were selected. By reviewing the article, each author then applied the inclusion and exclusion criteria, and 18 articles were selected. This systematic review aims to investigate the previous studies that used either VR and/or AR to treat any type of specific phobia in the last five years. The results demonstrated a positive outcome of virtual reality exposure treatment in the treatment of most phobias. In contrast, some of these treatments did not work for a few specific phobias in which the standard procedures were more effective. Besides, the study will also discuss the best of both technologies to treat a specific phobia. Furthermore, this review will present the limitations and future enhancements in this field

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Cutting parameters and vibrations analysis of magnetic bearing spindle in milling process

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    International audienceIn modern production, milling is considered the widespread cutting process in the formatting field. It remains important to study this manufacturing process as it can be subject to some parasitic phenomena that can degrade surface roughness of the machined part, increase tool wear and reduce spindle life span. In fact, the best quality work piece is obtained with a suitable choice of parameters and cutting conditions. In another hand, the study of tool vibrations and the cutting force attitude is related to the study of bearings as they present an essential part in the spindle system. In this work, a modeling of a High Speed Milling (HSM) spindle supported by two pair of Active Magnetic Bearings (AMB) is presented. The spindle is modeled by Timoshenko beam finite elements where six degrees of freedom are taken into account. The rigid displacements are also introduced in the modeling. Gyroscopic and centrifugal terms are included in the general equation. The bearings reaction forces are modeled as linear functions of journal displacement and velocity in the bearing clearance. A cutting force model for peripheral milling is proposed to estimate the tool-tip dynamic responses as well as dynamic cutting forces which are also numerically investigated. The time history of response, orbit, FFT diagram at the tool-tip center and the bearings dynamic coefficients are plotted to analyze dynamic behavior of the spindle
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