365 research outputs found

    Fine-grained reasoning about the security and usability trade-off in modern security tools

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    Defense techniques detect or prevent attacks based on their ability to model the attacks. A balance between security and usability should always be established in any kind of defense technique. Attacks that exploit the weak points in security tools are very powerful and thus can go undetected. One source of those weak points in security tools comes when security is compromised for usability reasons, where if a security tool completely secures a system against attacks the whole system will not be usable because of the large false alarms or the very restricted policies it will create, or if the security tool decides not to secure a system against certain attacks, those attacks will simply and easily succeed. The key contribution of this dissertation is that it digs deeply into modern security tools and reasons about the inherent security and usability trade-offs based on identifying the low-level, contributing factors to known issues. This is accomplished by implementing full systems and then testing those systems in realistic scenarios. The thesis that this dissertation tests is that we can reason about security and usability trade-offs in fine-grained ways by building and testing full systems. Furthermore, this dissertation provides practical solutions and suggestions to reach a good balance between security and usability. We study two modern security tools, Dynamic Information Flow Tracking (DIFT) and Antivirus (AV) software, for their importance and wide usage. DIFT is a powerful technique that is used in various aspects of security systems. It works by tagging certain inputs and propagating the tags along with the inputs in the target system. However, current DIFT systems do not track implicit information flow because if all DIFT propagation rules are directly applied in a conservative way, the target system will be full of tagged data (a problem called overtagging) and thus useless because the tags tell us very little about the actual information flow of the system. So, current DIFT systems drop some security for usability. In this dissertation, we reason about the sources of the overtagging problem and provide practical ways to deal with it, while previous approaches have focused on abstract descriptions of the main causes of the problem based on limited experiments. The second security tool we consider in this dissertation is antivirus (AV) software. AV is a very important tool that protects systems against worms and viruses by scanning data against a database of signatures. Despite its importance and wide usage, AV has received little attention from the security research community. In this dissertation, we examine the AV internals and reason about the possibility of creating timing channel attacks against AV software. The attacker could infer information about the AV based only on the scanning time the AV spends to scan benign inputs. The other aspect of AV this dissertation explores is the low-level AV performance impact on systems. Even though the performance overhead of AV is a well known issue, the exact reasons behind this overhead are not well-studied. In this dissertation, we design a methodology that utilizes Event Tracing for Windows technology (ETW), a technology that accounts for all OS events, to reason about AV performance impact from the OS point of view. We show that the main performance impact of the AV on a task is the longer waiting time the task spends waiting on events

    Angiotensin-Converting Enzyme (ACE) D Allele as a Risk Factor for Increase Serum Interleukin-6 and Interleukin-8 in Psoriasis Patients

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    BACKGROUND: Psoriasis is a chronic, recurrent inflammatory skin disease. It is characterised by autoimmune, environmental factors and complex genetic disorder.AIM: To explore the role of IL-6, IL-8, and ACE I/D polymorphism in the pathogenesis of Psoriasis and investigation of the relationship between ACE polymorphism and occurrence of psoriasis.PATIENTS AND METHODS: In this study, we took 73 psoriasis patients and 47 healthy patients as a control. These two groups subjected to analysis for ACE gene I/D polymorphism by PCR and biochemical methods.RESULTS: The serum levels of ACE, IL-8 and IL-6 were statistically significantly higher in psoriasis patients compared to healthy subjects (P < 0.001). ID and DD polymorphism were more common in psoriasis patients than healthy subjects. Also, D allele was significantly over-represented in patients compared to controls (52.7% Vs 35.1%).CONCLUSION: ACE gene polymorphism might grant susceptibility to develop psoriasis

    Study on the effect of the substrate material type and thickness on the performance of the filtering antenna design

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    This article presents a new design of a four-pole microstrip filtering antenna. The filtering antenna consists of a bandpass filter, which has four resonators integrated to a monopole patch antenna. The filtering antenna is designed with a relatively high bandwidth of about 1.22 GHz to satisfy a high-speed data transmission. Three types of dielectric substrate materials were used for the design of the filtering antenna, which is RT/Duroid 5880, RO3003, and FR-4. The simulation results of the filtering antenna design, which are established on the three different dielectric substrate materials, are done by using Computer Simulation Technology (CST) software. Comparison results of the filtering antenna that is established on the three different dielectric substrate materials are done at a fixed substrate height and different substrate heights. The filtering antenna is designed at a center frequency f0 = 2.412 GHz, which is suitable for WLAN applications

    Synthesis, CP-MAS NMR Characterization, and Antibacterial Activities of Glycine and Histidine Complexes of Cd(SeCN) 2

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    The synthesis and characterization of cadmium and mercury complexes of selenocyanate of the type [(L)M(SeCN)2] are described, where L is L-Histidine (His) or L-Glycine (Gly) and M is Cd2+ or Hg2+. These complexes are obtained by the reaction of 1 equivalent of respective amino acids with metal diselenocyanate precursor in a mixture of solvents (methanol : water = 1 : 1). These synthesized compounds are characterized by analytical and various spectroscopic techniques such as elemental analysis (EA), IR, H,1 and C13 NMR in solution and in the solid state for C13 and N15. The in vitro antibacterial activities of these complexes have been investigated with standard type cultures of Escherichia coli (MTCC 443), Klebsiella pneumoniae (MTCC 109), Pseudomonas aeruginosa (MTCC 1688), Salmonella typhi (MTCC 733), and Staphylococcus aureus (MTCC 737)

    A New and Compact Wide-Band Microstrip Filter-Antenna Design for 2.4 GHz ISM Band and 4G Applications

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    A new and compact four-pole wide-band planar filter-antenna design is proposed in this article. The effect of the dielectric material type on the characteristics of the design is also investigated and presented. The filter-antenna structure is formed by a fourth-order planar band-pass filter (BPF) cascaded with a monopole microstrip antenna. The designed filter-antenna operates at a centre frequency of 2.4 GHz and has a relatively wide-band impedance bandwidth of about 1.22 GHz and a fractional bandwidth (FBW) of about 50%. The effects of three different types of substrate material, which are Rogers RT5880, Rogers RO3003, and FR-4, are investigated and presented using the same configuration. The filter-antenna design is simulated and optimised using computer simulation technology (CST) software and is fabricated and measured using a Rogers RT5880 substrate with a height (h) of 0.81 mm, a dielectric constant of 2.2, and a loss tangent of 0.0009. The structure is printed on a compact size of 0.32 λ0 × 0.30 λ0, where λ0 is the free-space wavelength at the centre frequency. A good agreement is obtained between the simulation and measurement performance. The designed filter-antenna with the achieved performance can find different applications for 2.4 GHz ISM band and 4G wireless communications

    Impostor phenomenon among urologists in Saudi Arabia

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    Impostor phenomenon (IP) is the persistent inability to believe that one’s success is deserved or has been legitimately achieved due to one’s efforts or skills. It is associated with burnout, anxiety and depression and can negatively impact the lives of the affected individuals. This study aimed to determine the prevalence of IP among urologists in Saudi Arabia. A cross-sectional study was conducted among practicing urologists and urologists-in-training in Saudi Arabia between November and December 2022. A self-administered questionnaire comprising questions on the sociodemographic characteristics and the Clance impostor phenomenon scale (CIPS) was distributed through email to all registered urologists in the Saudi Commission for Health Specialties database. A total of 155 urologists (143 men and 12 women) were enrolled in this study. The majority of the urologists (44.5%) were consultants, and the prevalence of the impostor phenomenon in this study was 27.7%. Nearly half of the urologists (49.7%) presented moderate levels of the phenomenon, 23.9% of the urologists demonstrated high levels, and 20.6% presented low levels. Only 5.8% of the urologists showed intense levels of the phenomenon. The phenomenon was significantly more prevalent among those in training (p = 0.010) and less prevalent among those with a subspecialty in endourology (p = 0.016). The prevalence of the impostor phenomenon among urologists was 27.7%. It was more commonly seen in resident urologists, and those with a subspecialty in endourology were less likely to be affected by this phenomenon

    Assessment of Eating Habits and Lifestyle during Coronavirus Pandemic in the MENA region: A Cross-Sectional Study

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    © The Authors 2020. The coronavirus disease (COVID-19) has rapidly spread globally, forcing countries to apply lockdowns and strict social distancing measures. The aim of this study was to assess eating habits and lifestyle behaviors among residents of the Middle East and North Africa (MENA) region during the lockdown. A cross-sectional study among adult residents of the MENA region was conducted using an online questionnaire designed on Google Forms during April 2020. A total of 2970 participants from 18 countries participated in the current study. During the pandemic, over 30% reported weight gain, 6.2% consumed five or more meals per day compared to 2.2% before the pandemic (p\u3c0.001), and 48.8% did not consume fruits on daily basis. Moreover, 39.1% did not engage in physical activity, over 35% spent more than five hours per day on screens. A significant association between the frequency of training during the pandemic and the reported change in weight was found (p \u3c 0.001). A significantly higher percentage of participants reported physical and emotional exhaustion, irritability, and tension either all the time or a large part of the time during the pandemic (p \u3c 0.001). Although a high percentage of participants reported sleeping more hours per night during the pandemic, 63% had sleep disturbances. The study highlights that the lockdown due to the COVID-19 pandemic caused a variety of lifestyle changes, physical inactivity, and psychological problems among adults in the MENA region

    Cinnamon and ginger extracts attenuate diabetes-induced inflammatory testicular injury in rats and modulating SIRT1 expression

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    The current study aimed to evaluate the efficacy of simultaneous administration of Zingiber officinale (ginger) and Cinnamomum cassia (cinnamon) extracts in mitigating testicular changes associated with diabetes mellitus in rats and to investigate its molecular mode of action. After induction of diabetes using streptozotocin, 36 male rats were divided to six groups namely control, diabetic, metformin-treated, cinnamon-treated, ginger-treated and combined, each group having 6 rats. Fasting blood glucose, serum insulin, testosterone was measured. Expression of inflammatory mediators; tumor necrosis factor-alpha (TNF-α), Nuclear factor kappa B (NF-κB) and Sirtuin 1 (SIRT1) was assessed in the testicular tissue. Histopathological changes in the testis were observed and spermatogenesis and apoptosis were assessed immunohistochemically. The histological and biochemical studies of the untreated group confirmed structural changes in testes induced by diabetes. Oral administration of ginger and cinnamon increased insulin level significantly increased while the blood glucose level significantly decreased in diabetic rats, improving structural testicular changes considerably. Joint intake of ginger and cinnamon increased antihyperglycemic, antioxidant and anti-inflammatory effects markedly improving the testicular injury compared to the administration of either of them. SIRT1 expression in the testis significantly increased in ginger plus cinnamon-treated rats. These results indicate that when administrated together, ginger and cinnamon synergistically enhanced antioxidant, antiapoptotic and anti-inflammatory effects and induced antihyperglycemic effect comparable to metformin. The combination of ginger and cinnamon also upregulated SIRT1 in the testis

    The Palestinian Terrestrial Vertebrate Fauna Preserved at the Biology Exhibitions of the Universities of the Gaza Strip

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    The Gaza Strip (365 km2 ) of Palestine (27,000 km2 ) is home to a wealth of terrestrial vertebrate fauna. Some of these faunistic species find their ways to preservation at the local universities. Hence, the current study comes to document the Palestinian terrestrial vertebrate fauna acquired by the biology exhibitions (BEs) of Al-Azhar University, Islamic University of Gaza and Al-Aqsa University that are located at the Gaza City of the Gaza Strip. The amphibians, reptiles, birds and mammals preserved at BEs of the universities in question were surveyed and scientifically classified during a three-month period extending from January to March, 2012. The study showed that all BEs of local universities are underdeveloped, lacking attention and suffer from specimen scarcity and good preservation. The BE at Al-Azhar University is the best in the arrangement and preservation of bird specimens. A total number of 200 specimens belonging to 54 terrestrial vertebrate fauna species, 39 families and 17 orders was recorded at BEs. Reptiles constituted 40.7% of the total species recorded, followed by birds (38.9%), mammals (14.8%) and amphibians (5.6%). The Islamic University of Gaza was considered the best in terms of the number of preserved species (39.8%), followed by Al-Azhar University (36.3%) and Al-Aqsa University (23.9%). The Common Toad (Bufo viridis) was the most preserved among the amphibian species recorded. Squamata was the biggest reptilian order, comprising 20 species (8 lizards and 12 snakes), with the Syrian Black Snake (Coluber jugularis asianus) was the commonest. The Palestine Viper (Vipera palaestinae) is endemic to Palestine and most venomous and dangerous to human health. The Great White Pelican (Pelecanus onocrotalus) was the largest Palestinian bird preserved at BE of Al-Azhar University. The Egyptian Mongoose (Herpestes ichneumon) and the Common Badger (Meles meles) were the biggest mammalian specimens preserved, while the Palestine Mole-rat (Spalax leucodon ehrenbergi) was the only Palestine endemic species encountered among the preserved mammals. Finally, the improvement of BEs of local universities and the construction of a Central Museum of Natural History is highly recommended in order to change the Palestinians’ attitudes toward a sustainable ecological conservation in the Gaza Strip
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