1,238 research outputs found

    Preventing SQL Injection through Automatic Query Sanitization with ASSIST

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    Web applications are becoming an essential part of our everyday lives. Many of our activities are dependent on the functionality and security of these applications. As the scale of these applications grows, injection vulnerabilities such as SQL injection are major security challenges for developers today. This paper presents the technique of automatic query sanitization to automatically remove SQL injection vulnerabilities in code. In our technique, a combination of static analysis and program transformation are used to automatically instrument web applications with sanitization code. We have implemented this technique in a tool named ASSIST (Automatic and Static SQL Injection Sanitization Tool) for protecting Java-based web applications. Our experimental evaluation showed that our technique is effective against SQL injection vulnerabilities and has a low overhead.Comment: In Proceedings TAV-WEB 2010, arXiv:1009.330

    De la figure monstrueuse : de l'homme-spectacle à l'hyper-mùle ou une tentative de définition de mon histoire secrÚte

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    Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

    Mg substitution in CuCrO2 delafossite compounds

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    A detailed investigation of the series CuCr(1-x)MgxO2 (x = 0.0 - 0.05) has been performed by making high-temperature resistivity and thermopower measurements, and by performing a theoretical analysis of the latter. Microstructure characterization has been carried out as well. Upon Mg2+ for Cr3+ substitution, a concomitant decrease in the electrical resistivity and thermopower values is found, up to x ~ 0.02 - 0.03, indicating a low solubility limit of Mg in the structure. This result is corroborated by scanning electron microscopy observations, showing the presence of MgCr2O4 spinels as soon as x = 0.005. The thermopower is discussed in the temperature-independent correlation functions ratio approximation as based on the Kubo formalism, and the dependence of the effective charge carrier density on the nominal Mg substitution rate is addressed. This leads to a solubility limit of 1.1% Mg in the delafossite, confirmed by energy dispersive X-ray spectroscopy analysis.Comment: 6 pages, 5 figure

    312-fs pulse generation from a passive C-band InAs/InP quantum dot mode-locked laser.

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    For the first time, we report femtosecond pulses from a passive single-section InAs/InP quantum-dot (QD) mode-locked laser (MLL) with the active length of 456 microm and ridge width of 2.5 microm at the C-band wavelength range. Without any external pulse compression, the transform-limited Gaussian-pulses are generated at the 92 GHz repetition rate with the 312 fs pulse duration, which is the shortest pulse from any directly electric-pumping semiconductor MLLs to our best knowledge. The lasing threshold injection current and external differential quantum efficiency are 17.2 mA and 38%, respectively. We have also investigated the working principles of the proposed QD MLLs

    The EcoChip : a wireless multi-sensor platform for comprehensive environmental monitoring

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    This paper presents the EcoChip, a new system based on state-of-the-art electro-chemical impedance (EIS) technologies allowing the growth of single strain organisms isolated from northern habitats. This portable system is a complete and autonomous wireless platform designed to monitor and cultivate microorganisms directly sampled from their natural environment, particularly from harsh northern environments. Using 96-well plates, the EcoChip can be used in the field for realtime monitoring of bacterial growth. Manufactured with highquality electronic components, this new EIS monitoring system is designed to function at a low excitation voltage signal to avoid damaging the cultured cells. The high-precision calibration network leads to high-precision results, even in the most limiting contexts. Luminosity, humidity and temperature can also be monitored with the addition of appropriate sensors. Access to robust data storage systems and power supplies is an obvious limitation for northern research. That is why the EcoChip is equipped with a flash memory that can store data over long periods of time. To resolve the power issue, a low-power microcontroller and a power management unit control and supply all electronic building blocks. Data stored in the EcoChip’s flash memory can be transmitted through a transceiver whenever a receiver is located within the functional transmission range. In this paper, we present the measured performance of the system, along with results from laboratory tests in-vitro and from two field tests. The EcoChip has been utilized to collect bio-environemental data in the field from the northern soils and ecosystems of Kuujjuarapik and Puvirnituq, during two expeditions, in 2017 and 2018, respectively. We show that the EcoChip can effectively carry out EIS analyses over an excitation frequency ranging from 750 Hz to 10 kHz with an accuracy of 2.35%. The overall power consumption of the system was 140.4 mW in normal operating mode and 81 ”W in sleep mode. The proper development of the isolated bacteria was confirmed through DNA sequencing, indicating that bacteria thrive in the EcoChip’s culture wells while the growing conditions are successfully gathered and stored

    Bone ultrastructure and x-ray microanalysis of aluminum-intoxicated hemodialyzed patients

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    Bone ultrastructure and x-ray microanalysis of aluminum-intoxicated hemodialyzed patients. In hemodialyzed patients aluminum (Al) intoxication may induce osteomalacic lesions which are mainly observed when plasma immunoreactive parathyroid hormone (iPTH) concentrations are low, and osteitis fibrosa absent. In this study, the bone tissue of eight hemodialyzed patients with elevated plasma and bone Al concentrations was examined by histomorphometry, electron microscopy, and x-ray microanalysis. Five patients (group 1) had osteomalacia and minimal osteitis fibrosa, three patients (group 2) had severe osteitis fibrosa. In group 1, Al was concentrated at the mineralizing front, in hexagonal structures measuring 200 to 1,000 Å which also contained phosphorus, but not calcium. Hydroxyapatite needles had a normal aspect. Osteoblasts appeared inactive. In group 2, Al was also present at the mineralizing layer of osteoid, but, in these cases, in small clusters next to abnormal calcium deposits. Osteoblasts appeared very active. Their mitochondria contained calcium and phosphorus granules, or amorphous material, measuring 1,500 to 2,000 Å, emitting x-rays characteristic for Al and phosphorus. These results suggest that secondary hyperparathyroidism, by stimulating the cellular activity, may increase the uptake and release of Al by the osteoblasts. The presence of Al within the mitochondria of these cells may be one of the factors inducing the mineralization defect.Ultrastructure et microanalyse x du tissu osseux de malades hĂ©modialysĂ©s intoxiquĂ©s par l'aluminium. Chez des malades hĂ©modialysĂ©s l'intoxication par l'aluminium (Al) peut induire des lĂ©sions ostĂ©omalaciques qui s'observent principalement quand la concentration plasmatique de l'hormone parathyroĂŻdienne immunorĂ©active (iPTH) est peu augmentĂ©e, et en l'absence d'ostĂ©ite fibreuse. Dans cette Ă©tude le tissu osseux de huit malades hĂ©modialysĂ©s dont la concentration plasmatique et osseuse de l'Al Ă©tait Ă©levĂ©e, a Ă©tĂ© examinĂ© par l'histomorphomĂ©trie, la microscopie Ă©lectronique et la microanalyse x. Cinq malades (groupe 1) avaient une ostĂ©omalacie et des lĂ©sions minimes d'ostĂ©ite fibreuse, trois malades (groupe 2) avaient une ostĂ©ite fibreuse sĂ©vĂšre. Dans le groupe 1, l'Al Ă©tait concentrĂ© entre ostĂ©oĂŻde et tissu minĂ©ralisĂ©, dans des structures hexagonales mesurant 200 Ă  1000 Å, qui contenaient Ă©galement du phosphore, mais pas de calcium. Les aiguilles d'hydroxyapatite avaient un aspect normal. Les ostĂ©oblastes paraissaient peu actifs. Dans le groupe 2, l'Al Ă©tait aussi prĂ©sent entre ostĂ©oĂŻde et tissu minĂ©ralisĂ©, mais, dans ce cas, sous forme de petits amas, prĂšs de dĂ©pĂŽts anormaux de calcium. Les ostĂ©oblastes semblaient trĂšs actifs. Leurs mitochondries contenaient des granules de calcium et de phosphore ou bien du matĂ©riel amorphe, mesurant 1500 Ă  2000 Å, dont l'Ă©mission x Ă©tait caractĂ©ristique de l'Al et du phosphore. Ces rĂ©sultats suggĂšrent que l'hyperparathyroĂŻdie secondaire, en stimulant l'activitĂ© cellulaire, favorise la captation et le dĂ©pĂŽt de l'Al par les ostĂ©oblastes. La prĂ©sence d'Al dans les mitochondries de ces cellules pourrait ĂȘtre un des facteurs Ă  l'origine du trouble de la minĂ©ralisation

    Characteristics of semen from the Borgou bull in Benin

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    Une Ă©tude prĂ©liminaire concernant les principales caractĂ©ristiques du sperme chez le taureau de race Borgou (BĂ©nin) a permis d’obtenir les chiffres moyens suivants : volume de l’éjaculat 3,16 ml ; motilitĂ© de masse (Ă©chelle 0-5) 3,85 ; concentration en spermatozoĂŻdes 0,761 X lO’/rnl ; nombre de sper matozoĂŻdes, total 2,4 X 10', vivants l,98x 109. Un intervalle de 72 h entre les rĂ©coltes de sperme semble souhaitable, comparĂ© Ă  un intervalle de 48 h.Mean characteristics of semen from the Borgou bull were as follows : ejaculate volume 3.16 ml ; masse motility (0-5 scale) 3.85 ; sperm concen tration 0,761 X lO'/ml ; sperm number, total 2,4 X 109, living l,98x 109. Preliminary results following comparison of 48 and 72 hour intervals bet ween semen collections showed a slight advantage to the latter

    SOCL: An OpenCL Implementation with Automatic Multi-Device Adaptation Support

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    To fully tap into the potential of today's heterogeneous machines, offloading parts of an application on accelerators is not sufficient. The real challenge is to build systems where the application would permanently spread across the entire machine, that is, where parallel tasks would be dynamically scheduled over the full set of available processing units. In this report we present SOCL, an OpenCL implementation that improves and simplifies the programming experience on heterogeneous architectures. SOCL enables applications to dynamically dispatch computation kernels over processing devices so as to maximize their utilization. OpenCL applications can incrementally make use of light extensions to automatically schedule kernels in a controlled manner on multi-device architectures. A preliminary automatic granularity adaptation extension is also provided. We demonstrate the relevance of our approach by experimenting with several OpenCL applications on a range of representative heterogeneous architectures. We show that performance portability is enhanced by using SOCL extensions.Pour exploiter au mieux les architectures hĂ©tĂ©rogĂšnes actuelles, il n'est pas suffisant de dĂ©lĂ©guer aux accĂ©lĂ©rateurs seulement quelques portions de codes bien dĂ©terminĂ©es. Le vĂ©ritable dĂ©fi consiste Ă  dĂ©livrer des applications qui exploitent de façon continue la totalitĂ© de l'architecture, c'est-Ă -dire dont l'ensemble des tĂąches parallĂšles les composant sont dynamiquement ordonnancĂ©es sur les unitĂ©s d'exĂ©cution disponibles. Dans ce document, nous prĂ©sentons SOCL, une implĂ©mentation de la spĂ©cification OpenCL Ă©tendue de sorte qu'elle soit plus simple d'utilisation et plus efficace sur les architectures hĂ©tĂ©rogĂšnes. Cette implĂ©mentation peut ordonnancer automatiquement les noyaux de calcul sur les accĂ©lĂ©rateurs disponibles de façon Ă  maximiser leur utilisation. Les applications utilisant dĂ©jĂ  OpenCL peuvent ĂȘtre migrĂ©es de façon incrĂ©mentale et contrĂŽlĂ©e vers SOCL car les extensions fournies sont non intrusives et requiĂšrent trĂšs peu de modifications dans les codes. En plus de l'ordonnancement automatique de noyaux de calcul, une extension prĂ©liminaire permettant l'adaptation automatique de la granularitĂ© est mise Ă  disposition. Nous dĂ©montrons la pertinence de cette approche et l'efficacitĂ© des extensions fournies Ă  travers plusieurs expĂ©rimentations sur diverses architectures hĂ©tĂ©rogĂšnes reprĂ©sentatives

    High prevalence of the arginine catabolic mobile element in carriage isolates of methicillin-resistant Staphylococcus epidermidis

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    Background The arginine catabolic mobile element (ACME) associated with staphylococcal cassette chromosome mec (SCCmec) in the USA300 clone of community-acquired methicillin-resistant Staphylococcus aureus enhances its fitness and ability to colonize the host. Staphylococcus epidermidis may act as a reservoir of ACME for S. aureus. We assessed the diffusion of ACME in methicillin-resistant S. epidermidis (MRSE) isolates colonizing outpatients. Methods Seventy-eight MRSE strains isolated in outpatients from five countries were characterized by multilocus sequence typing (MLST) and SCCmec typing and screened for the arcA and opp3AB markers of ACME. ACME-arcA and ACME-opp3AB were sequenced. ACME type I from MRSE and USA300 were compared by long-range PCR (LR-PCR). Results Fifty-three (67.9%) MRSE strains carried an ACME element, including 19 (24.4%), 32 (41.0%) and 2 (2.6%) with ACME type I (arcA+/opp3AB+), II (arcA+/opp3AB−) and III (arcA−/opp3AB+), respectively. The prevalence of ACME did not differ between clonal complex 2 (42/60 strains) and other sequence types (11/18 strains, P = 0.7), with MLST data suggesting frequent intraspecies acquisition. ACME-arcA sequences were highly conserved, whereas ACME-opp3AB displayed 11 distinct allotypes. ACME was found in 14/29, 9/11 and 30/37 strains with type IV, type V and non-typeable SCCmec, respectively (P = 0.01). ACME was more frequently associated with ccrC than with ccrAB2 (82.4% versus 60.0%, P = 0.048). LR-PCR indicated structural homologies of ACME I between MRSE and USA300. Conclusions ACME is widely disseminated in MRSE strains colonizing outpatients and may contribute to their spread in a community environment with low antibiotic exposure, as suggested for USA30
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