A Cooperative and Hybrid Network Intrusion Detection Framework in Cloud Computing Based on Snort and Optimized Back Propagation Neural Network

AbstractCloud computing provides a framework for supporting end users easily attaching powerful services and applications through Internet. To give secure and reliable services in cloud computing environment is an important issue. Providing security requires more than user authentication with passwords or digital certificates and confidentiality in data transmission, because it is vulnerable and prone to network intrusions that affect confidentiality, availability and integrity of Cloud resources and offered services. To detect DoS attack and other network level malicious activities in Cloud, use of only traditional firewall is not an efficient solution. In this paper, we propose a cooperative and hybrid network intrusion detection system (CH-NIDS) to detect network attacks in the Cloud environment by monitoring network traffic, while maintaining performance and service quality. In our NIDS framework, we use Snort as a signature based detection to detect known attacks, while for detecting network anomaly, we use Back-Propagation Neural network (BPN). By applying snort prior to the BPN classifier, BPN has to detect only unknown attacks. So, detection time is reduced. To solve the problem of slow convergence of BPN and being easy to fall into local optimum, we propose to optimize the parameters of it by using an optimization algorithm in order to ensure high detection rate, high accuracy, low false positives and low false negatives with affordable computational cost. In addition, in this framework, the IDSs operate in cooperative way to oppose the DoS and DDoS attacks by sharing alerts stored in central log. In this way, unknown attacks that were detected by any IDS can easily be detected by others IDSs. This also helps to reduce computational cost for detecting intrusions at others IDS, and improve detection rate in overall the Cloud environment

Magnetic properties in amorphous Co95­xDyxZr5 thin films

Amorphous Co95-xDyxZr5 thin films were prepared by RF sputtering and their magnetic properties were studied as a function of temperature and for the composition range 0<x<30. The mean field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Dy-Co atom pairs have been evaluated. The magnetic phase diagrams are presented.Amorphous Co95-xDyxZr5 thin films were prepared by RF sputtering and their magnetic properties were studied as a function of temperature and for the composition range 0<x<30. The mean field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Dy-Co atom pairs have been evaluated. The magnetic phase diagrams are presented

Modeling and analysis of loaded multilayered magnetoelectroelastic structures composite materials: Applications

This paper presents the detailed analysis of fiber- reinforced magnetoelectroelastic composite plates. The work is divided into two major sections. The first one deals with the homogenization of the properties of each layer based on the Mori-Tanaka mean field approach where all the needed effective coefficients of each layer are determined. Then, in order to perform analysis of the considered, the Stroh formalism is used to provide solutions for multifunctional multilayered magnetoelectroelastic composites, to predict exactly the mechanical and electrical behaviors near or across the interface of material layers

the significant effect of size and concentrations of iron oxide nanoparticles on magnetic resonance imaging contrast enhancement

In this study, iron oxide (γ-Fe2O3) nanoparticles (IONs) were successfully synthesized using sol-gel method, and characterized by XRD and VSM. The potential application of the differently sized IONs (22 nm and 30 nm) as magnetic resonance imaging (MRI) contrast agents was investigated. The relaxation time (T2) of the IONs was measured at room temperature and concentration range of 9–84 µg/ml using fast spin echo sequence with six echoes. The size was found to affect the contrast enhancement of the MRI image, with the T2 for 22 nm sized γ-Fe2O3 nanoparticles exhibiting a shorter dephasing compared to the 30 nm sized γ-Fe2O3 nanoparticles. The T2 relaxivity also decreased with increasing concentration (9–84 µg/ml) of the γ-Fe2O3 nanoparticles. Based on the T2-weighted analysis, a better signal (i.e. brighter image) was achieved for the 30 nm sized γ-Fe2O3 nanoparticles. Thus, the use of IONs to enhance MR image contrast is dependent on the nanoparticle size and concentration of the IONs. In general, the results indicate that the synthesized γ-Fe2O3 nanoparticles are promising materials for use as MRI contrast agents. Keywords: Magnetic resonance imaging, Iron oxides nanoparticles, T2 relaxivity, XRD, VS

Molecular generation and characterization of an efficient recombinant vaccine for avian influenza A/H5N8 in Saudi Arabia

Purpose: To characterize a highly pathogenic avian influenza (HPAI) H5N8 for engineering recombinant 6-+ 2 vaccine strain based on reverse genetic technology. Methods: A total of 135 swab samples from various birds were collected from different parts of Saudi Arabia as part of an influenza surveillance activity. The samples were checked for influenza virus infection using reverse transcriptase-polymerase chain reaction (RT-PCR). Furthermore, Avian influenza H5N8 (A/chicken/KSA/1-NRC/2018), was used for the generation of H5N8 vaccine strain. The vaccine was tested on specific pathogen-free (SPF) chicken purchased from a local market. Results: The results indicate that the candidate vaccine (rgH5N8/KSA) induced specific neutralizing antibodies in chicken, and thereby protected the chickens from subsequent infections of H5N8. Conclusion: The study reinforces the development of a vaccine against avian influenza H5N8 virus isolated in Saudi Arabia, suggesting its possible application against the influenza virus associated with bird fl

Activity and Interactions of Liposomal Antibiotics in Presence of Polyanions and Sputum of Patients with Cystic Fibrosis

BACKGROUND:To compare the effectiveness of liposomal tobramycin or polymyxin B against Pseudomonas aeruginosa in the Cystic Fibrosis (CF) sputum and its inhibition by common polyanionic components such as DNA, F-actin, lipopolysaccharides (LPS), and lipoteichoic acid (LTA). METHODOLOGY:Liposomal formulations were prepared from a mixture of 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine (DMPC) or 1,2-Dipalmitoyl-sn-Glycero-3-Phosphocholine (DPPC) and Cholesterol (Chol), respectively. Stability of the formulations in different biological milieus and antibacterial activities compared to conventional forms in the presence of the aforementioned inhibitory factors or CF sputum were evaluated. RESULTS:The formulations were stable in all conditions tested with no significant differences compared to the controls. Inhibition of antibiotic formulations by DNA/F-actin and LPS/LTA was concentration dependent. DNA/F-actin (125 to 1000 mg/L) and LPS/LTA (1 to 1000 mg/L) inhibited conventional tobramycin bioactivity, whereas, liposome-entrapped tobramycin was inhibited at higher concentrations--DNA/F-actin (500 to 1000 mg/L) and LPS/LTA (100 to 1000 mg/L). Neither polymyxin B formulation was inactivated by DNA/F-actin, but LPS/LTA (1 to 1000 mg/L) inhibited the drug in conventional form completely and higher concentrations of the inhibitors (100 to 1000 mg/L) was required to inhibit the liposome-entrapped polymyxin B. Co-incubation with inhibitory factors (1000 mg/L) increased conventional (16-fold) and liposomal (4-fold) tobramycin minimum bactericidal concentrations (MBCs), while both polymyxin B formulations were inhibited 64-fold. CONCLUSIONS:Liposome-entrapment reduced antibiotic inhibition up to 100-fold and the CFU of endogenous P. aeruginosa in sputum by 4-fold compared to the conventional antibiotic, suggesting their potential applications in CF lung infections

COVID‐19 effect on patients with noncommunicable diseases: a narrative review

Background and Aims: On March 11, 2020, the WHO has declared COVID‐19 a global pandemic, affecting our day‐to‐day lives. Physical distancing and lockdown made significant obstacles to populations, particularly healthcare systems. Most healthcare workers were reallocated to COVID‐19 facilities. Noncommunicable disease patients were given low priority and are at a higher risk of severe COVID‐19 infection, which disrupted the treatment and disease management of these patients. This review aimed to assess the effect of COVID‐19 on different types of noncommunicable diseases and the severity it may cause to patients. Methods: We have conducted a review of the literature on COVID‐19 and noncommunicable diseases from December 2019 until January 2022. The search was done in PubMed and Cochrane for relevant articles using variety of searching terms. Data for study variables were extracted. At the end of the selection process, 46 papers were selected for inclusion in the literature review. Result: The result from this review found that the COVID‐19 pandemic has affected the efficiency of the patient's treatment indirectly by either delaying or canceling sessions, which solidified the need to rely more on telemedicine, virtual visits, and in‐home visits to improve patient education and minimize the risk of exposure to the patients. The major and most common types of noncommunicable diseases are known to be related to the severe outcomes of COVID‐19 infection. It is strongly recommended to prioritize these patients for vaccinations against COVID‐19 to provide them with the protection that will neutralize the risk imposed by their comorbidities. Conclusion: We recommend conducting more studies with larger population samples to further understand the role of noncommunicable diseases (NCDs) in this pandemic. However, this pandemic has also affected the efficiency of NCDs treatment indirectly by delaying or canceling sessions and others

Placental Growth Factor Contributes to Micro-Vascular Abnormalization and Blood-Retinal Barrier Breakdown in Diabetic Retinopathy

OBJECTIVE: There are controversies regarding the pro-angiogenic activity of placental growth factor (PGF) in diabetic retinopathy (DR). For a better understanding of its role on the retina, we have evaluated the effect of a sustained PGF over-expression in rat ocular media, using ciliary muscle electrotransfer (ET) of a plasmid encoding rat PGF-1 (pVAX2-rPGF-1). MATERIALS AND METHODS: pVAX2-rPGF-1 ET in the ciliary muscle (200 V/cm) was achieved in non diabetic and diabetic rat eyes. Control eyes received saline or naked plasmid ET. Clinical follow up was carried out over three months using slit lamp examination and fluorescein angiography. After the control of rPGF-1 expression, PGF-induced effects on retinal vasculature and on the blood-external barrier were evaluated respectively by lectin and occludin staining on flat-mounts. Ocular structures were visualized through histological analysis. RESULTS: After fifteen days of rPGF-1 over-expression in normal eyes, tortuous and dilated capillaries were observed. At one month, microaneurysms and moderate vascular sprouts were detected in mid retinal periphery in vivo and on retinal flat-mounts. At later stages, retinal pigmented epithelial cells demonstrated morphological abnormalities and junction ruptures. In diabetic retinas, PGF expression rose between 2 and 5 months, and, one month after ET, rPGF-1 over-expression induced glial activation and proliferation. CONCLUSION: This is the first demonstration that sustained intraocular PGF production induces vascular and retinal changes similar to those observed in the early stages of diabetic retinopathy. PGF and its receptor Flt-1 may therefore be looked upon as a potential regulatory target at this stage of the disease

Molecular study of the perforin gene in familial hematological malignancies

Perforin gene (PRF1) mutations have been identified in some patients diagnosed with the familial form of hemophagocytic lymphohistiocytosis (HLH) and in patients with lymphoma. The aim of the present study was to determine whether patients with a familial aggregation of hematological malignancies harbor germline perforin gene mutations. For this purpose, 81 unrelated families from Tunisia and France with aggregated hematological malignancies were investigated. The variants detected in the PRF1 coding region amounted to 3.7% (3/81). Two of the three variants identified were previously described: the p.Ala91Val pathogenic mutation and the p.Asn252Ser polymorphism. A new p.Ala 211Val missense substitution was identified in two related Tunisian patients. In order to assess the pathogenicity of this new variation, bioinformatic tools were used to predict its effects on the perforin protein structure and at the mRNA level. The segregation of the mutant allele was studied in the family of interest and a control population was screened. The fact that this variant was not found to occur in 200 control chromosomes suggests that it may be pathogenic. However, overexpression of mutated PRF1 in rat basophilic leukemia cells did not affect the lytic function of perforin differently from the wild type protein