375 research outputs found

    A survey on the (in)security of trusted execution environments

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    As the number of security and privacy attacks continue to grow around the world, there is an ever increasing need to protect our personal devices. As a matter of fact, more and more manufactures are relying on Trusted Execution Environments (TEEs) to shield their devices. In particular, ARM TrustZone (TZ) is being widely used in numerous embedded devices, especially smartphones, and this technology is the basis for secure solutions both in industry and academia. However, as shown in this paper, TEE is not bullet-proof and it has been successfully attacked numerous times and in very different ways. To raise awareness among potential stakeholders interested in this technology, this paper provides an extensive analysis and categorization of existing vulnerabilities in TEEs and highlights the design flaws that led to them. The presented vulnerabilities, which are not only extracted from existing literature but also from publicly available exploits and databases, are accompanied by some effective countermeasures to reduce the likelihood of new attacks. The paper ends with some appealing challenges and open issues.Funding for open access charge: Universidad de Málaga / CBUA This work has been partially supported by the Spanish Ministry of Science and Innovation through the SecureEDGE project (PID2019-110565RB-I00), and by the by the Andalusian FEDER 2014–2020 Program through the SAVE project (PY18-3724)

    Bi-spectral infrared algorithm for cloud coverage over oceans by the jem-euso mission program

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    The need to monitor specific areas for different applications requires high spatial and temporal resolution. This need has led to the proliferation of ad hoc systems on board nanosatellites, drones, etc. These systems require low cost, low power consumption, and low weight. The work we present follows this trend. Specifically, this article evaluates a method to determine the cloud map from the images provided by a simple bi-spectral infrared camera within the framework of JEM-EUSO (The Joint Experiment Missions-Extrem Universe Space Observatory). This program involves different experiments whose aim is determining properties of Ultra-High Energy Cosmic Ray (UHECR) via the detection of atmospheric fluorescence light. Since some of those projects use UV instruments on board space platforms, they require knowledge of the cloudiness state in the FoV of the instrument. For that reason, some systems will include an infrared (IR) camera. This study presents a test to generate a binary cloudiness mask (CM) over the ocean, employing bi-spectral IR data. The database is created from Moderate-Resolution Imaging Spectroradiometer (MODIS) data (bands 31 and 32). The CM is based on a split-window algorithm. It uses an estimation of the brightness temperature calculated from a statistical study of an IR images database along with an ancillary sea surface temperature. This statistical procedure to obtain the estimate of the brightness temperature is one of the novel contributions of this work. The difference between the measured and estimation of the brightness temperature determines whether a pixel is cover or clear. That classification requires defining several thresholds which depend on the scenarios. The procedure for determining those thresholds is also novel. Then, the results of the algorithm are compared with the MODIS CM. The agreement is above 90%. The performance of the proposed CM is similar to that of other studies. The validation also shows that cloud edges concentrate the vast majority of discrepancies with the MODIS CM. The relatively high accuracy of the algorithm is a relevant result for the JEM-EUSO program. Further work will combine the proposed algorithm with complementary studies in the framework of JEM-EUSO to reinforce the CM above the cloud edges.This research was funded by MADRID GOVERNMENT (Comunidad de Madrid;Spain), PEJ-2018-AI_TIC-11476 and by the SPANISH MINISTRY (MICINN), RTI2018-099825-B-C33. The APC was funded by the MADRID GOVERNMENT, EPUC3M14

    Expression profiling and localization of wall polysaccharides in the olive pollen during in vitro germination

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    1 página.-- Comunicación oral presentada en la XVIII Reunión de la Sociedad Española de Fisiología Vegetal (SEFV).-- Sesión Temática 2: Crecimiento y desarrollo.-- S2-O2.This work was supported by the Andalusian Regional Government (project P06-AGR-01791). C. Suarez thanks the MEC for providing FPI grant funding.Peer reviewe

    Olive cultivar origin is a major cause of polymorphism for Ole e 1 pollen allergen

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    <p>Abstract</p> <p>Background</p> <p>Pollens from different olive (<it>Olea europaea </it>L.) cultivars have been shown to differ significantly in their content in Ole e 1 and in their overall allergenicity. This allergen is, in addition, characterized by a high degree of polymorphism in its sequence. The purpose of this study is to evaluate the putative presence of divergences in Ole e 1 sequences from different olive cultivars.</p> <p>Results</p> <p>RNA from pollen individually collected from 10 olive cultivars was used to amplify Ole e 1 sequences by RT-PCR, and the sequences were analyzed by using different bioinformatics tools. Numerous nucleotide substitutions were detected throughout the sequences, many of which resulted in amino acid substitutions in the deduced protein sequences. In most cases variability within a single variety was much lower than among varieties. Key amino acid changes in comparison with "canonical" sequences previously described in the literature included: a) the substitution of C19-relevant to the disulphide bond structure of the protein-, b) the presence of an additional N-glycosylation motif, and c) point substitutions affecting regions of Ole e 1 already described like relevant for the immunogenicity/allergenicity of the protein.</p> <p>Conclusion</p> <p>Varietal origin of olive pollen is a major factor determining the diversity of Ole e 1 variants. We consider this information of capital importance for the optimal design of efficient and safe allergen formulations, and useful for the genetic engineering of modified forms of the allergen among other applications.</p

    Differential characteristics of olive pollen from different cultivars: Biological and clinical implications

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    The olive tree is grown in many parts of the world. Its germplasm is very broad, with 250 varieties in Spain alone. Variations in the ability of pollen to germinate have been studied in detail and show conspicuous differences between varieties. However, commercial olive pollen from cultivars whose origin is unknown is the material that is commonly used for clinical and biological studies. We aim to assess the putative heterogeneity of olive cultivars with regard to the presence of several pollen allergens and to determine whether these differences have biological and clinical relevance. Previous studies show that most allergens isolated and characterized to date are highly polymorphic. Olive cultivars display wide differences in the expression levels of many allergens and in the number and molecular characteristics of the allergen isoforms expressed. These differences are maintained over the years, and are intrinsic to the genetics of each cultivar. Such broad polymorphism seems to be involved in the physiology of the olive reproductive system, which might include the adaptation of the plant to different environmental conditions, the establishment of the compatibility system, and pollen performance. The differences in allergen composition in cultivars, particularly in the Ole e 1 allergen, are responsible for the important differences in the allergenic potency of the extracts. These fi ndings could have a number of implications for the diagnosis and therapy of olive pollen allergy. We discuss how cultivar differences affect extract quality, diagnostic and therapeutic effi cacy and safety, and the development of new vaccines based on the use of recombinant allergens.El olivo es un cultivo ampliamente representado en el mundo. Su germoplasma es muy amplio, con 250 variedades sólo en España. La capacidad del polen para germinar, que presenta notables diferencias entre variedades, ha sido estudiada en detalle. El material usado comúnmente para estudios clínicos y biológicos es, sin embargo, polen comercial de cultivares de origen desconocido. Nuestro objetivo es evaluar la posible heterogeneidad de los cultivares de olivo en relación a la presencia de varios alérgenos del polen, y determinar si esas diferencias tienen relevancia biológica y clínica. Estudios previos muestran que la mayor parte de los alérgenos aislados y caracterizados hasta la fecha son altamente polimórfi cos. Los cultivares de olivo muestran amplias diferencias en los niveles de expresión de muchos alérgenos, así como en el número y características moleculares de las isoformas alergénicas expresadas. Estas diferencias se mantienen a lo largo de años, y son intrínsecas a la genética de cada cultivar. Este amplio polimorfi smo parece estar implicado en la fi siología del sistema reproductivo del olivo, en relación con la adaptación de la planta a diferentes condiciones ambientales, el establecimiento de un sistema de compatibilidad, y el dinamismo del polen. Las diferencias en la composición alergénica de los cultivares, particularmente en cuanto al alérgeno Ole e 1, son responsables de las importantes diferencias en la potencia alergénica de los extractos. Estos hallazgos pueden tener numerosas implicaciones en la diagnosis y terapia de la alergia al polen del olivo. Discutimos cómo las diferencias entre cultivares afectan a la calidad del polen, a la efi cacia y seguridad del diagnóstico y la terapia, así como al desarrollo de nuevas vacunas basadas en el uso de alérgenos recombinantes

    Pollen Allergenicity is Highly Dependent on the Plant Genetic Background: The “Variety”/“Cultivar” Issues

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    This work was funded by ERDF (co)-financed projects P2010-CVI5767, P2010-AGR6274, BFU2011-22779, P2011-CVI-7487 and PEOPLE-IOF/1526.Peer reviewe

    Controlling Robot Motion by Blinking Eyes: an Experience on Users Training

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    This article aims to describe a system designed to control the movement of mobile robots by blinking eyes. It is based on the use of a Brain Computer Interface and a particular control architecture. The paper addresses the key aspects that allow simplifying usersrobot interaction and proposes a control strategy that facilitates a fast learning of robot handling. In this sense, the main advantage of the approach is the short period of time required for users’ training. The article details a methodology aimed to evaluate this feature, presents experimental results that confirm this fact and also discusses about the influence of interacting with a real or a simulated robot. Particularly, it analyses if a previous training with the virtual robot helps to improve the interaction with the real robot or vice versa

    Hardware timestamping for image acquisition system based on FlexRIO and IEEE 1588 v2 Standard

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    Current fusion devices consist of multiple diagnostics and hundreds or even thousands of signals. This situation forces on multiple occasions to use distributed data acquisition systems as the best approach. In this type of distributed systems, one of the most important issues is the synchronization between signals, so that it is possible to have a temporal correlation as accurate as possible between the acquired samples of all channels. In last decades, many fusion devices use different types of video cameras to provide inside views of the vessel during operations and to monitor plasma behavior. The synchronization between each video frame and the rest of the different signals acquired from any other diagnostics is essential in order to know correctly the plasma evolution, since it is possible to analyze jointly all the information having accurate knowledge of their temporal correlation. The developed system described in this paper allows timestamping image frames in a real-time acquisition and processing system using 1588 clock distribution. The system has been implemented using FPGA based devices together with a 1588 synchronized timing card (see Fig.1). The solution is based on a previous system [1] that allows image acquisition and real-time image processing based on PXIe technology. This architecture is fully compatible with the ITER Fast Controllers [2] and offers integration with EPICS to control and monitor the entire system. However, this set-up is not able to timestamp the frames acquired since the frame grabber module does not present any type of timing input (IRIG-B, GPS, PTP). To solve this lack, an IEEE1588 PXI timing device its used to provide an accurate way to synchronize distributed data acquisition systems using the Precision Time Protocol (PTP) IEEE 1588 2008 standard. This local timing device can be connected to a master clock device for global synchronization. The timing device has a buffer timestamp for each PXI trigger line and requires tha- a software application assigns each frame the corresponding timestamp. The previous action is critical and cannot be achieved if the frame rate is high. To solve this problem, it has been designed a solution that distributes the clock from the IEEE 1588 timing card to all FlexRIO devices [3]. This solution uses two PXI trigger lines that provide the capacity to assign timestamps to every frame acquired and register events by hardware in a deterministic way. The system provides a solution for timestamping frames to synchronize them with the rest of the different signals

    Digital Control Implementation to Reduce the Cost and Improve the Performance of the Control Stage of an Industrial Switched-Mode Power Supply

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    The main objective of this work is the design and implementation of the digital control stage of a 280W AC/DC industrial power supply in a single low-cost microcontroller to replace the analog control stage. The switch-mode power supply (SMPS) consists of a PFC boost converter with fixed frequency operation and a variable frequency LLC series resonant DC/DC converter. Input voltage range is 85VRMS-550VRMS and the output voltage range is 24V-28V. A digital controller is especially suitable for this kind of SMPS to implement its multiple functionalities and to keep the efficiency and the performance high over the wide range of input voltages. Additional advantages of the digital control are reliability and size. The optimized design and implementation of the digital control stage it is presented. Experimental results show the stable operation of the controlled system and an estimation of the cost reduction achieved with the digital control stage
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