Security Mechanisms of Distributed Denial-Of-Service (DDOS) Attack in Everything-as-a-Service (XaaS) - Survey

— This paper illustrates research on DDoS attack which overload targeted servers with traffic to render hosted resources inaccessible and unavailable. The attacks are increasingly being launched from multiple locations, gradually spreading over larger networks, consequently to obscure the attack origin. The precipitous cloud computing as the new ‘anywhere anytime’ paradigm, in the form of Everything-as-a-Service (XaaS), transforms these attack mechanisms to become progressively destructive, affecting Quality Of Service (QoS) performance. The attack vectors examination ranges from volumetric attack that flood network links, to application layer attack that target specific services, to protocol attack that exhaust network's resources, with evolving consequences. DDoS attacks mitigation in XaaS environments poses unique challenges. Current literature explores the limitations of traditional on-premise and XaaS-based mitigation techniques to instantaneously detect and mitigate malicious traffic. The role of intelligent analytics in distinguishing legitimate and malicious traffic are also being investigated by application of machine learning algorithms to safeguard against prospective interruptions to XaaS-based services’ availability and reliabilit

Heat transfer in a channel with inclined target surface cooled by single array of centered impinging jets

An experimental investigation has been carried out to study the heat transfer characteristics in a channel with heated target plate inclined at an angle cooled by single array of equally spaced centered impinging jets for three different jet Reynolds numbers (Re=9300, 14400 and 18800). Air ejected from an array of orifices impinges on the heated target surface The target plate forms the leading edge of a gas turbine blade cooled by jet impingement technique. The work includes the effect of jet Reynolds numbers and feed channel aspect ratios (H/d = 5, 7, 9 where H=2.5, 3.5, 4.5 cm and d=0.5 cm) on the heat transfer characteristics for a given orifice jet plate configuration with equally spaced centered holes with outflow exiting in both directions (with inclined heated target surface). In general, It has been observed that, H/d=9 gives the maximum heat transfer over the entire length of the target surface as compared to all feed channel aspect ratios. H/d=9 gives 3% more heat transfer from the target surface as compared to H/d=5 (for Re=14400). Also, it has been observed that the magnitude of the averaged local Nusselt number increases with an increase in the jet Reynolds number for all the feed channel aspect ratios studied

Towards a New Vision for Sustainability of Incubator Best Practices Model in the Years to Come

Incubators are internationally recognized as a premier 21st century location for technology and technology-based economic development. The purpose of this paper is to identify the similarities and differences of business incubation programs worldwide. The study focuses on six key success indicators and points out proposed incubators model in the years to come. The approach to the design methodology is based on survey and interviews implanted on 100 selected incubators. The research findings indicate the similarities of incubators programs that are 1) Creating jobs, 2) Enhancing community’s entrepreneurial climate, and 3) Tangible services and the differences are 1) Incubators type, 2) Finical status, and 3) Incubators age. The research adds value to current literature on new visions for sustainability of incubators best practice models for the coming year. Finally, it provides useful guidelines for implementation to both academies and practitioners involved with incubators worldwide. Keywords: Technology incubators, innovation, entrepreneurship, job creation, economic development

Effect of Jet Lag on Postural Stability

Postural stability is essential in people’s daily life. Crossing time zones can disrupt our body clock and lead to jet lag. Some studies reported that jet lag affects human physical and cognitive functions. To the best of the authors’ knowledge, none of these studies examined the effects of jet lag on postural stability. Twenty-two healthy young adult males between 23 and 36 years of age who had a round trip flight planned between the United States and Saudi Arabia were recruited. Participants attended one preflight assessment and three post-flight assessments (within 24 hours, 48 hours, 72 hours). Participants were divided into 2 groups based on their selection upon arrival (group 1: post-flight visit 1 prior sleeping at home and group 2: attended post-flight visit 1 after sleeping one night at home). Participant’s postural stability was assessed using computerized dynamic posturography. A questionnaire was used to measure their experiences during the flight. Significant improvements in postural stability were observed in group 2 during the second post-flight assessment (p\u3c0.05). There was a no significant impact on participant’s postural stability while flying westward crossing more than ten time zones during the first twenty-four hours; however, it was improved within seventy-two hours. Many body systems contribute to support postural stability, one of which is the vestibular system. Vestibular rehabilitation has many terminology conflicts that can have a negative impact on patient management and general understanding of the content. Therefore, the author performed a literature review to identify several of these conflicts and provided recommendations for minimizing these conflicts

Impact of turbulence-induced asymmetric propagators on the accuracy of phase-contrast velocimetry

Phase-contrast magnetic resonance velocimetry (PC-MRI) has been widely used to investigate flow properties in numerous systems. In a horizontal cylindrical pipe (3mm diameter), we investigated the accuracy of PC-MRI as the flow transitioned from laminar to turbulent flow (Reynolds number 352 to 2708). We focus primarily on velocimetry errors introduced by skewed intra-voxel displacement distributions, a consequence of PC-MRI theory assuming symmetric distributions. We demonstrated how rapid fluctuations in the velocity field, can produce broad asymmetric intravoxel displacement distributions near the wall. Depending on the shape of the distribution, this resulted in PC-MRI measurements under-estimating (positive skewness) or over-estimating (negative skewness) the true mean intravoxel velocity, which could have particular importance to clinical wall shear stress measurements. The magnitude of these velocity errors was shown to increase with the variance and decrease with the kurtosis of the intravoxel displacement distribution. These experimental results confirm our previous theoretical analysis, which gives a relationship for PC-MRI velocimetry errors, as a function of the higher moments of the intravoxel displacement distribution (skewness, variance, and kurtosis) and the experimental parameters q and Δ. This suggests that PC-MRI errors in such unsteady/turbulent flow conditions can potentially be reduced by employing lower q values or shorter observation times Δ

Epidemiological Study on Rift Valley Fever Virus among Domestic Animals in Taiz Governorate (Yemen)

Rift Valley Fever Virus (RVFV) is the causative agent of Rift Valley Fever (RVF), transmitted either by hematophagous insects that infect animals and humans or by direct contact with infected animals. This study was performed to preparing RVF antigen from liver of infected lamb to be used in detecting anti-RVFV antibodies by using Enzyme Linked immunosorbent assay (ELISA) and to study epidemiological prevalence of anti-RVFV IgM and IgG antibodies among animals which conducted in the Researches Center of Taiz University and Central Health Laboratory, Taiz Governorate, Southwestern Yemen. RVFV antigen was successfully prepared at a titer dilution of 1: 3200 by Chessboard (CB) ELISA assay. However, out of 188 samples, 147 samples were positive for ELISA assay, of which 12 (8.2 %) were positive for anti-RVFV IgM and 135 (91.8 %) for anti-IgG antibodies. The antigen was successfully produced, and successfully adhered to ELISA plates. Simple and inexpensive methods give good results. The results can be used to develop and refine predictive database for RVF transmission based on environmental and remote sensing data

Basidiobolomycosis of the Colon Masquerading as Stenotic Colon Cancer

Basidiobolus ranarum is a widespread saprophyte fungus with pathogenic potential. It affects mainly the subcutaneous tissues of the trunk and limbs. Relatively recently, occasional reports of gastrointestinal basidiobolomycosis appeared in the literature. Due to the rarity of the condition and the nonspecific presenting features, the correct diagnosis is usually hard to reach. In this paper, we describe the clinical course of an otherwise healthy female, who presented with a colonic mass. She received subtotal colectomy followed by oral itraconazole, with successful outcome

Histopathologic profile of esophageal atresia and tracheoesophageal fistula

Purpose Few reports are available in the literature on the histology of the congenital atretic esophagus in humans. Histologic abnormalities  including congenital esophageal stenosis (CES) may contribute toward the abnormal esophageal motility after successful repair of esophageal atresia (EA) and tracheoesophageal fistula (TEF). The main aim of this study is to document the histopathologic profile in cases of EA.Methods One hundred and nineteen surgical specimens were collected from 69 consecutive EA patients who underwent surgical repair at the Aseer Central Hospital, Abha, and Armed Forces Hospital Southern Region, Saudi Arabia, from May 1999 through May 2009. This included 62 cases with EA and distal TEF, five cases of pure EA, and two cases of N-type TEF. Samples from tips of the upper pouch (UP), lower pouch (LP), and mid portion of the TEF were preserved in 10% formalin, sectioned, and stained with hematoxylin and eosin.Results The combined three elements of tracheobronchial tissue were observed in only three LP specimens. Gastrictype mucosa was seen in one UP and one LP specimen. Except for one N-type fistula, all sections showed fullthickness muscle coats. Distortion of muscles by fibrosis was most commonly seen in the UP. The muscle layer in the LP was more commonly distorted by glands with or without cartilage. Fourteen samples (10.8%) showed a histological picture consistent with CES.Conclusion Glands in the submucosa may be abnormal innumber and type, and may extend to different esophageal  coats. Muscle distortion by fibrosis, glands, or cartilage and associated CES may contribute toward esophageal dysmotility and stricture after surgery. Cutting the TEF B3–5mm distal to its origin from the trachea is adequate histologically for primary anastomosis of the atretic esophagus. The histological changes associated with the TEF need to be revised.Keywords: congenital esophageal stenosis, esophageal atresia,  esophageal dysmotility, histopatholog