10 research outputs found

    Securing Cloud Data in the New Attacker Model

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    The world just witnessed the surge of a new and powerful attacker, which was able to coerce operators and acquire the necessary keys to break the privacy of users. Once the encryption key is exposed, the only viable measure to preserve data confidentiality is to limit the adversary鈥檚 access to the ciphertext. This may be achieved, for example, using multi-cloud storage systems. These systems spread data across multiple servers in different administrative domains, to cater for availability and fault tolerance. If the adversary can only compromise a subset of these domains, multi-cloud storage systems may prevent the adversary from accessing the entire ciphertext. However, if data is encrypted using existing encryption schemes, spreading the ciphertext on multiple servers does not entirely solve the problem since an adversary which has the encryption key, can still compromise single servers and decrypt the ciphertext stored therein. In this paper, we leverage multi-cloud storage systems to provide data confidentiality against an adversary which has access to the encryption key, and can compromise a large fraction of the storage servers. For this purpose, we first introduce a novel security definition that captures data confidentiality in the new adversarial model. We then propose Bastion, a primitive that is secure according to our definition and, therefore, guarantees data confidentiality even when the encryption key is exposed, as long as the adversary cannot compromise all storage servers. We analyze the security of Bastion, and we evaluate its performance by means of a prototype implementation. Our results show that Bastion incurs less than 5% overhead compared to existing semantically secure encryption modes. We also discuss practical insights with respect to the integration of Bastion in commercial multi-cloud storage systems

    Liver transplantation due to resistant to therapy bacterial biliary tract infection in the patient after kidney transplantation

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    W pracy przedstawiono rzadki przypadek pacjenta po transplantacji nerki, u kt贸rego wyst膮pi艂o niecharakterystyczne, zar贸wno klinicznie, jak i diagnostycznie, bakteryjne zapalenie wewn膮trzw膮trobowych dr贸g 偶贸艂ciowych. Zanim przeprowadzono przeszczepienie nerki, z powodu kamicy przewodowej za艂o偶ono choremu stent do dr贸g 偶贸艂ciowych, nast臋pnie wykonano cholecystektomi臋. D艂ugotrwa艂a celowana antybiotykoterapia nie przynios艂a korzystnych efekt贸w i pojawi艂o si臋 bezpo艣rednie zagro偶enie 偶ycia pacjenta, dlatego zdecydowano si臋 na zabieg transplantacji w膮troby. Dalszy przebieg choroby by艂 pomy艣lny. Aktualnie obydwa przeszczepione narz膮dy funkcjonuj膮 bardzo dobrze.The purpose of our paper is presenting a rare case of a patient after the kidney transplantation. He developed non-characteristic both clinical and diagnostic bacterial biliary tract infection. Before the transplantation because of the stones in his biliary tract he had introduced a stent and later he had cholecystectomy. Because of lack of positive results after prolonged and aimed antibiotic therapy as well as direct risk of death the transplantation of liver was performed. Further course of disease was successful. Currently the function of transplanted organs is good

    Expression of KIM-1, VEGF and bFGF in the transplanted kidney as predictive factors of kidney allograft function

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    Introduction: Transplantation is now a common treatment for kidney failure. However, it is associated with numerous complications, among which is rejection. Currently, factors that can predict the function of the transplanted kidney are being sought. This study aimed to investigate whether the expression of KIM-1 (kidney injury molecule-1), VEGF (vascular endothelial growth factor) and bFGF (basic fibroblast growth factor) assessed in the transplanted kidney before transplantation can be a predictive marker of the later function of the transplanted kidney and the occurrence of complications such as delayed graft function (DGF) and acute rejection (AR). Material and methods: The study group included 44 kidney allograft recipients who underwent kidney transplantation. Results: There were no statistically significant correlations between KIM-1, VEGF and bFGF gene expression in transplanted kidney biopsies and the occurrence of DGF and AR. The expression of the bFGF gene correlated significantly with the creatinine levels before and on the first day after transplantation. There were no statistically significant correlations between creatinine levels and expression of the KIM-1 and VEGF genes. There was also no statistically significant correlation between bFGF, KIM-1 and VEGF gene expression in the transplanted kidney and later eGFR and diuresis values. A statistically significant negative correlation was found between bFGF and serum potassium levels before transplantation and up to one month after transplantation. KIM-1 expression correlated significantly negatively with pre-transplant serum potassium levels. VEGF expression correlated significantly negatively with potassium levels 2 and 24 months after transplantation. Conclusions: The present results suggest that the expression of KIM-1, VEGF and bFGF assessed in the transplanted kidney before transplantation is not a significant predictor of the later function of the transplanted kidney. The expression of the bFGF gene correlates with the creatinine levels before and on the first day after transplantation. The expression of KIM-1, VEGF and bFGF may correlate with potassium serum levels

    Anticancer Activity of Natural Compounds from Plant and Marine Environment

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    This paper describes the substances of plant and marine origin that have anticancer properties. The chemical structure of the molecules of these substances, their properties, mechanisms of action, their structure鈥揳ctivity relationships, along with their anticancer properties and their potential as chemotherapeutic drugs are discussed in this paper. This paper presents natural substances from plants, animals, and their aquatic environments. These substances include the vinca alkaloids, mistletoe plant extracts, podophyllotoxin derivatives, taxanes, camptothecin, combretastatin, and others including geniposide, colchicine, artesunate, homoharringtonine, salvicine, ellipticine, roscovitine, maytanasin, tapsigargin, and bruceantin. Compounds (psammaplin, didemnin, dolastin, ecteinascidin, and halichondrin) isolated from the marine plants and animals such as microalgae, cyanobacteria, heterotrophic bacteria, invertebrates (e.g., sponges, tunicates, and soft corals) as well as certain other substances that have been tested on cells and experimental animals and used in human chemotherapy

    Special Issue on “Advancement in Computational Fluid Mechanics and Optimization Methods”

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    In recent years, CFD methods have become a universal engineering tool for modeling many classes of flows [...

    D-Optimal Simultaneous Multistep Excitations for Aircraft Parameter Estimation

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    Experimental Validation of Total Energy Control System for UAVs

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    This paper presents an analysis of a Total Energy Control System (TECS) introduced by Lambregts to control unmanned aerial vehicle (UAV) velocity and altitude by using the total energy distribution. Furthermore, an extended Kalman filter (EKF) approach was used to predict aircraft response in terms of angular rates and linear acceleration during a test flight campaign. From both approaches, state equations were obtained to model the aircraft using Matlab-Simulink. From an aerodynamic study, airplane characteristics were obtained in terms of non-dimensional derivatives and compared to those obtained from the experimental methods. It was determined that TECS approach was very accurate; however, disturbance errors could be decreased by adjusting some model parameters. On the other hand, it was difficult to obtain a real estimation from the EKF method due to the presence of turbulence during flight and the relatively low inertia of the scale model. Dynamic characteristics were validated using a low-cost inertial sensor that cab be easily integrated in UAV platforms. The gathered data can be used to predict model characteristics by integrating the information into flight simulators for future design development

    Muscle Fatigue in the Temporal and Masseter Muscles in Patients with Temporomandibular Dysfunction

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    The aim of this study is to evaluate muscle fatigue in the temporal and masseter muscles in patients with temporomandibular dysfunction (TMD). Two hundred volunteers aged 19.3 to 27.8 years (mean 21.50, SD 0.97) participated in this study. Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany). Muscle fatigue was evaluated on the basis of a maximum effort test. The test was performed during a 10-second maximum isometric contraction (MVC) of the jaws. An analysis of changes in the mean power frequency of the two pairs of temporal and masseter muscles (MPF%) revealed significant differences in the groups of patients with varying degrees of temporomandibular disorders according to Di (P<0.0000). The study showed an increase in the muscle fatigue of the temporal and masseter muscles correlated with the intensity of temporomandibular dysfunction symptoms in patients. The use of surface electromyography in assessing muscle fatigue is an excellent diagnostic tool for identifying patients with temporomandibular dysfunction

    Analysis of Outcomes in Ischemic vs Nonischemic Cardiomyopathy in Patients With Atrial Fibrillation A Report From the GARFIELD-AF Registry

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    IMPORTANCE Congestive heart failure (CHF) is commonly associated with nonvalvular atrial fibrillation (AF), and their combination may affect treatment strategies and outcomes
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