209 research outputs found
AndroShield:automated Android applications vulnerability detection, a hybrid static and dynamic analysis approach
The security of mobile applications has become a major research field which is associated with a lot of challenges. The high rate of developing mobile applications has resulted in less secure applications. This is due to what is called the “rush to release” as defined by Ponemon Institute. Security testing—which is considered one of the main phases of the development life cycle—is either not performed or given minimal time; hence, there is a need for security testing automation. One of the techniques used is Automated Vulnerability Detection. Vulnerability detection is one of the security tests that aims at pinpointing potential security leaks. Fixing those leaks results in protecting smart-phones and tablet mobile device users against attacks. This paper focuses on building a hybrid approach of static and dynamic analysis for detecting the vulnerabilities of Android applications. This approach is capsuled in a usable platform (web application) to make it easy to use for both public users and professional developers. Static analysis, on one hand, performs code analysis. It does not require running the application to detect vulnerabilities. Dynamic analysis, on the other hand, detects the vulnerabilities that are dependent on the run-time behaviour of the application and cannot be detected using static analysis. The model is evaluated against different applications with different security vulnerabilities. Compared with other detection platforms, our model detects information leaks as well as insecure network requests alongside other commonly detected flaws that harm users’ privacy. The code is available through a GitHub repository for public contribution
Single step biotransformation of corn oil phytosterols to boldenone by a newly isolated Pseudomonas aeruginosa
AbstractA new potent Pseudomonas aeruginosa isolate capable for biotransformation of corn oil phytosterol (PS) to 4-androstene-3, 17-dione (AD), testosterone (T) and boldenone (BOL) was identified by phenotypic analysis and 16S rRNA gene sequencing. Sequential statistical strategy was used to optimize the biotransformation process mainly concerning BOL using Factorial design and response surface methodology (RSM). The production of BOL in single step microbial biotransformation from corn oil phytosterols by P. aeruginosa was not previously reported. Results showed that the pH concentration of the medium, (NH4)2SO4 and KH2PO4 were the most significant factors affecting BOL production. By analyzing the statistical model of three-dimensional surface plot, BOL production increased from 36.8% to 42.4% after the first step of optimization, and the overall biotransformation increased to 51.9%. After applying the second step of the sequential statistical strategy BOL production increased to 53.6%, and the overall biotransformation increased to 91.9% using the following optimized medium composition (g/l distilled water) (NH4)2SO4, 2; KH2PO4, 4; Na2HPO4. 1; MgSO4·7H2O, 0.3; NaCl, 0.1; CaCl2·2H2O, 0.1; FeSO4·7H2O, 0.001; ammonium acetate 0.001; Tween 80, 0.05%; corn oil 0.5%; 8-hydroxyquinoline 0.016; pH 8; 200rpm agitation speed and incubation time 36h at 30°C. Validation experiments proved the adequacy and accuracy of model, and the results showed the predicted value agreed well with the experimental values
High-throughput molecular identification of Staphylococcus spp. isolated from a clean room facility in an environmental monitoring program
<p>Abstract</p> <p>Background</p> <p>The staphylococci are one of the most common environmental isolates found in clean room facility. Consequently, isolation followed by comprehensive and accurate identification is an essential step in any environmental monitoring program.</p> <p>Findings</p> <p>We have used the API Staph identification kit (bioMérieux, France) which depends on the expression of metabolic activities and or morphological features to identify the <it>Staphylococcus </it>isolates. The API staphylococci showed low sensitivity in the identification of some species, so we performed molecular methods based on PCR based fingerprinting of glyceraldehyde-3-phosphate dehydrogenase encoding gene as useful taxonomic tool for examining <it>Staphylococcus </it>isolates.</p> <p>Conclusions</p> <p>Our results showed that PCR protocol used in this study which depends on genotypic features was relatively accurate, rapid, sensitive and superior in the identification of at least 7 species of <it>Staphylococcus </it>than API Staph which depends on phenotypic features.</p
Međudjelovanje četiri-razinskog atoma u impulsnom svojstvenom stanju s jednomodnim poljem
We study the interaction between a four-level atom (ladder type) in a momentum eigenstate with a single mode cavity field in the presence of non-linearities of both the field and the intensity-dependent coupling. The constants of motion and the wave function for the atomic system have been obtained. Special attention is given to discuss some statistical aspects of the considered atomic system such as momentum increment, momentum diffusion and high-order squeezing. The influence of the Kerr-like medium and the intensity dependent coupling on the momentum increment and the high-order squeezing are investigated numerically. It is found that addition of these parameters has an important effect on both the momentum increment and the squeezing phenomenon.Proučavamo međudjelovanje četiri-razinskog atoma (poput ljestvi) u impulsnom svojstvenom stanju s jednomodnim poljem u rezonatoru, uz nelinearnosti polja i vezanja ovisnog o intenzitetu. Izveli smo stalnice gibanja valne funkcije atomskog sustava. Posebnu smo pažnju posvetili raspravi o statističkim odlikama razmatranog atomskog sustava, kao što su povećanje i difuzija impulsa i zbijanje višeg reda. Numerički smo istražili utjecaj Kerrovog sredstva i vezanja ovisnog o intenzitetu na povećanje impulsa i zbijanje višeg reda. Našli smo da dodavanje tih parametara ima snažan učinak na povećanje impulsa i pojavu zbijanja
Screening for diabetes among tuberculosis patients: a nationwide population-based study in Egypt
Background: The prevalence of type 2 diabetes mellitus (DM) is increasing rapidly in Egypt and considered one of the major health problems in the Eastern Mediterranean region. Objectives: To measure the prevalence of diabetes and detect the undiagnosed cases of diabetes mellitus among patient with tuberculosis. Methods: Study Design: Nationwide population-based study. To diagnose DM among TB patients, we used a fasting blood sugar level of ≥ 126 mg/dl and a post-prandial blood glucose test result of ≥ 200 mg/dl. Results: Screening for DM among 1435 TB patients' with no history of DM detected 30 new cases of DM, with a case detection rate of 2.09%. The highest screening yields were among TB patients aged ≥ 40 years, females and those with pulmonary TB. The number needed to screen (NNS) TB patients for detecting one new case of DM was 48 while the lowest values were for older age (NNS=27) and females (NNS=29). Conclusion: Older age and being females and those with pulmonary type of TB were more prone to the double burden of TB and DM. Identifying cases with double burden of diseases will improve the proper management of both diseases and prevent complications. Keywords: Screening test, diabetes mellitus, tuberculosis
Study of event-driven and periodic rescheduling on a single machine with unexpected disruptions
This paper studies the rescheduling problem of a single machine facing unexpected disruptions in order to determine which parameters can help reducing the negative impacts of these disruptions on schedule performance. A Genetic Algorithm (GA) is used to generate the initial schedule and the updated ones according to a reactive strategy. The performance of event-driven rescheduling and periodic rescheduling policies are compared in terms of total tardiness and total cost of rescheduling. Other factors that may affect rescheduling such as disruption time, disruption duration and number of disruptions are investigated. The sensitivity of results to both due date tightness and cost factor variation is tested. The results showed that the timing of the occurrence of disruption as related to scheduling horizon has a major effect on determining the best rescheduling policy. Event-driven policy is superior to other policies for short infrequent disruptions. It was found that the periodic policy is more appropriate for long and frequent disruptions
Expression and purification of recombinant Shiga toxin 2B from Escherichia coli O157:H7
Enterohemorrhagic Escherichia coli are important human food-borne pathogens. Recently, Shiga toxinproducing E. coli (STEC) causes life-threatening hemolytic-uremic syndrome (HUS). In this study, Stx2B gene, a subunit of Shiga toxin, was amplified via polymerase chain reaction (PCR) from the chromosomal DNA of clinical fecal sample using appropriate primers. The PCR product was cloned to commercially available plasmid pH6HTN His6HaloTag® T7 containing two purification tags, namely, six histadine tag and Halo tag. The integrity of the constructed plasmid was confirmed using restriction enzyme mapping and sequencing. Then, Stx2B protein expressed after induction with isopropyl β-D-1-thiogalactopyranoside (IPTG) in E. coli JM109 (DE3) under the control of the T7 promotor. The two step purification trains were used to purify native Stx2B. First step purification was Ni-immobilized metal ion affinity chromatography (IMAC) column, followed by second step using HaloLink resin. The native Stx2B was obtained after column cleavage of halo-tag using HaloTEV protease. Maximum protein expression of Stx2B economically was obtained using 1 mM IPTG for 4 h at 37°C. Protein identity was confirmed by a band at ~11.4 kDa using 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and StxB2 yield was 450 μg ml-1 confirmed by Bradford assay. Recombinant Stx2B protein was produced in highly pure yield using HaloTag technology.Key words: Escherichia coli O157:H7, StxB gene, expression, HaloTag technology, purification
Immunohistochemical Expression of “L1 cell Adhesion Molecule†in Endometrial Carcinomas
BACKGROUND: Endometrial cancer is the most common cancer of the female genital tract. No effective biomarkers currently exist to allow for an efficient risk classification of endometrial carcinoma or to direct treatment (adjuvant radiation and/or chemotherapy) or to triage pelvic and para-aortic lymphadenectomy. L1 cell adhesion molecule (L1CAM) a transmembrane protein of the immunoglobulin family that has been implicated in promoting tumor cell proliferation, migration, invasion, and metastasis became an attractive candidate as a potential biomarker in endometrial carcinoma and potential therapeutic target in high-risk groups.
OBJECTIVES: Evaluation of L1CAM expression in endometrial carcinoma and correlation of this expression with various pathological parameters.
MATERIALS AND METHODS: Immunohistochemical staining for L1CAM was performed on paraffin-embedded sections of 80 cases of endometrial carcinomas that underwent total hysterectomy with bilateral salpingo-oophorectomy. Expression of L1CAM in >10% of tumor cells was interpreted as positive.
RESULTS: L1CAM expression was detected in 22.5% of cases and showed statistically significant correlation with non-endometrioid histological type, high grade, high FIGO stage, high pathological (T) stage, cervical involvement, nodal metastasis, lymphovascular space invasion, and high-risk tumor according to the European Society for Medical Oncology system for risk stratification (p < 0.05).
CONCLUSION: The high rate of L1CAM expression in high-risk endometrial carcinomas suggests that L1CAM represents a potential marker for the identification of patients needing closer follow-up and aggressive treatment. In addition, its potential role as a therapeutic target for high-risk endometrial cancer seems promising
Design and Implementation of Portable PC-Based ECG Machine
The design and implementation of a portable PC based ECG system is discussed in this theses. ECG recording normally uses three-electrod
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