368 research outputs found

    Lattice-Based proof of a shuffle

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    In this paper we present the first fully post-quantum proof of a shuffle for RLWE encryption schemes. Shuffles are commonly used to construct mixing networks (mix-nets), a key element to ensure anonymity in many applications such as electronic voting systems. They should preserve anonymity even against an attack using quantum computers in order to guarantee long-term privacy. The proof presented in this paper is built over RLWE commitments which are perfectly binding and computationally hiding under the RLWE assumption, thus achieving security in a post-quantum scenario. Furthermore we provide a new definition for a secure mixing node (mix-node) and prove that our construction satisfies this definition.Peer ReviewedPostprint (author's final draft

    sVote with control components voting protocol: computational proof of complete verifiability and privacy

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    This document details the cryptographic analysis of the sVote v2.2.1 system - an e-voting solution developed by Scytl for the Switzerland context. We prove the complete verifiability and privacy under the Swiss legislation's informally stated goals. First, we derive the trust model for complete verifiability and voting secrecy from the Swiss Chancellery's requirements, supporting our interpretation by quotes from and references to relevant excerpts of the ordinance and the corresponding technical annex. Then, based on the derived model, we prove that sVote with Control Components provides complete verifiability and guarantees voting secrecy and the non-disclosure of early provisional results. We demonstrate that sVote fulfills the requirements of the Swiss federal chancellery for completely verifiable E-voting systems. In other words, we show that an adversary cannot break the complete verifiability and voting secrecy properties of sVote without being detected by either the voter or auditors.sVote with Control components is a cryptographic voting protocol that provides complete verifiability and guarantees voting secrecy and the non-disclosure of early provisional results. This report demonstrates that sVote fulfills the requirements of the Swiss federal chancellery for completely verifiable E-voting systems. We extract precise requirements from the ordinance and the corresponding technical annex and model the sVote cryptographic voting protocol based on its design documents. Based on this model, we show in a detailed security analysis that an adversary cannot break the complete verifiability and voting secrecy properties of sVote without being detected by either the voter or by auditorsThis work has received funding from the European Commission under the auspices of PROMETHEUS Project, Horizon 2020 Innovation Action (Grant Agreement No. 780701).Preprin

    A community of marine bacteria with potential to biodegrade petroleum-based and biobased microplastics

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    The biodegradability conditions for both, petroleum-based plastics and bioplastics needs to be evaluated under environmentally realistic conditions. We assessed the biodegradability of low-density polyethylene and biobased polyethylene terephthalate microplastic films by a consortium of marine bacteria during 45 days. Bacterial growth and pH were higher in the samples inoculated with bacteria, compared to the controls. Fourier Infrared spectroscopy-Attenuated Total Reflectance and scanning electron microscopy indicated changes in the chemical functional groups, and the presence of fractures and biofilms in the surface of both plastics exposed to the bacterial community, respectively. The chemical oxygen demand further indicated signs of biodegradation of both polymers. Specific groups of bacteria showed preference for each type of microplastic. Overall, our results show signs of biodegradation, or at least biodeterioration and biofragmentation, of both types of plastics, when subjected to the selected bacterial community. Biobased PET was no more prone to biodegradation than con-ventional, petroleum-based LDPE.info:eu-repo/semantics/publishedVersio

    VtaA8 and VtaA9 from Haemophilus parasuis delay phagocytosis by alveolar macrophages

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    Haemophilus parasuis, a member of the family Pasteurellaceae, is a common inhabitant of the upper respiratory tract of healthy pigs and the etiological agent of Glässer's disease. As other virulent Pasteurellaceae, H. parasuis can prevent phagocytosis, but the bacterial factors involved in this virulence mechanism are not known. In order to identify genes involved in phagocytosis resistance, we constructed a genomic library of the highly virulent reference strain Nagasaki and clones were selected by increased survival after incubation with porcine alveolar macrophages (PAM). Two clones containing two virulent-associated trimeric autotransporter (VtaA) genes, vtaA8 and vtaA9, respectively, were selected by this method. A reduction in the interaction of the two clones with the macrophages was detected by flow cytometry. Monoclonal antibodies were produced and used to demonstrate the presence of these proteins on the bacterial surface of the corresponding clone, and on the H. parasuis phagocytosis-resistant strain PC4-6P. The effect of VtaA8 and VtaA9 in the trafficking of the bacteria through the endocytic pathway was examined by fluorescence microscopy and a delay was detected in the localization of the vtaA8 and vtaA9 clones in acidic compartments. These results are compatible with a partial inhibition of the routing of the bacteria via the degradative phagosome. Finally, antibodies against a common epitope in VtaA8 and VtaA9 were opsonic and promoted phagocytosis of the phagocytosis-resistant strain PC4-6P by PAM. Taken together, these results indicate that VtaA8 and VtaA9 are surface proteins that play a role in phagocytosis resistance of H. parasuis

    sVote with Control Components Voting Protocol. Computational Proof of Complete Verifiability and Privacy.

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    This document details the cryptographic analysis of the sVote v2.2.1 system - an e-voting solution developed by Scytl for the Switzerland context. We prove the complete verifiability and privacy under the Swiss legislation\u27s informally stated goals. First, we derive the trust model for complete verifiability and voting secrecy from the Swiss Chancellery\u27s requirements [1][2], supporting our interpretation by quotes from and references to relevant excerpts of the ordinance and the corresponding technical annex. Then, based on the derived model, we prove that sVote with Control Components provides complete verifiability and guarantees voting secrecy and the non-disclosure of early provisional results. We demonstrate that sVote fulfills the requirements of the Swiss federal chancellery for completely verifiable E-voting systems. In other words, we show that an adversary cannot break the complete verifiability and voting secrecy properties of sVote without being detected by either the voter or auditors. [1] Technical and administrative requirements for electronic vote casting v 2.0 https://www.bk.admin.ch/dam/bk/en/dokumente/pore/Annex_of_the_Federal_Chancellery_Ordinance_on_Electronic_Voting_V2.0_July_2018.pdf.download.pdf/Annex_of_the_Federal_Chancellery_Ordinance_on_Electronic_Voting_V2.0_July_2018.pdf [2] Federal Chancellery Ordinance on Electronic Voting https://www.fedlex.admin.ch/eli/cc/2013/859/e

    Marine forests of the Mediterranean-Atlantic Cystoseira tamariscifolia complex show a southern Iberian genetic hotspot and no reproductive isolation in parapatry

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    Climate-driven range-shifts create evolutionary opportunities for allopatric divergence and subsequent contact, leading to genetic structuration and hybrid zones. We investigate how these processes influenced the evolution of a complex of three closely related Cystoseira spp., which are a key component of the Mediterranean-Atlantic seaweed forests that are undergoing population declines. The C. tamariscifolia complex, composed of C. tamariscifolia s.s., C. amentacea and C. mediterranea, have indistinct boundaries and natural hybridization is suspected. Our aims are to (1) infer the genetic structure and diversity of these species throughout their distribution ranges using microsatellite markers to identify ancient versus recent geographical populations, contact zones and reproductive barriers, and (2) hindcast past distributions using niche models to investigate the influence of past range shifts on genetic divergence at multiple spatial scales. Results supported a single, morphologically plastic species the genetic structure of which was incongruent with a priori species assignments. The low diversity and low singularity in northern European populations suggest recent colonization after the LGM. The southern Iberian genetic hotspot most likely results from the role of this area as a climatic refugium or a secondary contact zone between differentiated populations or both. We hypothesize that life-history traits (selfing, low dispersal) and prior colonization effects, rather than reproductive barriers, might explain the observed genetic discontinuities.Pew Charitable Trusts (USA); MARINERA, Spain [CTM2008-04183-E/MAR]; FCT (Portugal) [FCT-BIODIVERSA/004/2015, CCMAR/Multi/04326/2013, SFRH/BPD/107878/2015, SFRH/BPD/85040/2012]; FPU fellowship of the Spanish Ministry of Education; European Community ASSEMBLE visiting grant [00399/2012]; University of Cadi

    Simultaneous nitrogen and dissolved methane removal from an upflow anaerobic sludge blanket reactor effluent using an integrated fixed-film activated sludge system

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    One of the main drawbacks of upflow anaerobic sludge blanket (UASB) reactors that treat low-strength sewage at room temperature is related to the low quality of their effluents in terms of dissolved methane, organic matter, and nitrogen content. The present study aims to evaluate the feasibility of using an integrated fixed-film activated sludge (IFAS) system as an alternative post-treatment technology to mitigate the environmental impact of such effluents. For this purpose, a pilot plant composed of a UASB (120 L) followed by an IFAS (66 L) system was operated for 407 days. Special attention was paid to the suspended biomass retention capacity and the dissolved methane and nitrogen removal potential of the IFAS post-treatment system. Furthermore, the role of carriers on denitrification and nitrification processes and the microbial communities present in the biofilm were also analyzed. Average total chemical oxygen demand (CODT) and ammonium removal efficiencies of 92 ± 3% and around 57 ± 16% were attained throughout the entire operation, respectively. During a first period in which biomass was maintained in both biofilms and suspension, and nitrite was the main electron acceptor, maximum nitrogen removal and methane removal efficiencies of 32.5 mg TN L-1 and 93% were observed in the IFAS system, respectively. However, throughout the second period, in which suspended biomass was completely washed out from the IFAS system, and nitrate became the main electron acceptor, these values decreased to 18 ± 4 mg TN Lfeed-1 and 77 ± 12%, respectively. Surprisingly, throughout the entire operation, it was observed that around 50 and 41% of the total nitrogen and methane removals observed in the IFAS system, respectively, were carried out in the aerobic compartment. Aerobic methane oxidizers and anammox were detected with significant relative abundances in the biofilm carriers used in the anoxic and aerobic compartments using 16S rRNA gene amplicon sequencing analysis. Therefore, the use of an IFAS system could be suited to diminish greenhouse gas emissions and nutrients concentration for those sewage treatment plants that used UASB systems, especially in countries with temperate and warm climatesThis research was supported by the Ministry of Economy and Competitiveness of Spain through the COMETT project (CTQ2016-80847-R) and by the Ministry of Education and Science of Spain through the Red Novedar project (CTQ2014-51693-REDC). T. Allegue would also like to express his gratitude to the Ministry of Economy and Competitiveness of Spain for awarding a research scholarship (BES-2014-069114). The authors belong to the Galician Network of Environmental Technologies (ED341D R2016/033) and to the CRETUS Strategic Partnership (ED431E 2018/01), financed by the Galician GovernmentS

    Consideraciones para el diseño de Apps para bebés

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    [EN] In recent years there has been an explosion of applications targeted at children, even babies. As our research shows, 50% of Spanish families are using Apps with their children who are under two years old. Despite being a very vulnerable target, there is no specific documentation for developers to create Apps that are appropriate for babies. For this reason, we conducted an investigation from the point of view of pedagogy, child psychology and design, to create a guide with recommendations for the development of applications for babies. The guide will support the design of new Apps for very young children so as to minimize possible adverse effects while enhancing benefits. The guide with recommendations for designing Apps for babies covers a wide range of information from formats and aesthetics to appropriate recreational, educational and interactive content related to each stage of the baby’s development.[ES] En los últimos años ha habido una explosión de Aplicaciones enfocadas al publico infantil, incluso para bebés. Según muestra investigación, el 50% de las familias españolas usa Apps con sus hijos menores de 2 años. A pesar de ser un target muy vulnerable, no existe documentación específica para que los desarrolladores creen Apps apropiadas para bebés. Ante tal necesidad, llevamos a cabo una investigación desde el punto de vista de la pedagogía, la psicología infantil y el diseño, para crear una guía con recomendaciones para el desarrollo de Aplicaciones para bebés. La guía servirá de apoyo a la hora de diseñar nuevas Apps para niños tan pequeños de forma que se minimicen sus posibles efectos negativos y se potencien sus beneficios. La guía con recomendaciones para diseñar Apps para bebés abarca una amplia gama de información que trata desde formatos y estéticas adecuadas a cada etapa evolutiva, hasta el contenido lúdico, educativo e interactivo apropiado para los pequeños.http://ocs.editorial.upv.es/index.php/ILUSTRAFIC/ILUSTRAFIC2015Morante Bonet, M.; Rodríguez, N.; Costa, M. (2015). Consideraciones para el diseño de Apps para bebés. Editorial Universitat Politècnica de València. 250-261. https://doi.org/10.4995/ILUSTRAFIC/ILUSTRAFIC2015/226OCS25026

    Heterogeneity of Moraxella isolates found in the nasal cavities of piglets

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    Background Previous studies have shown that the genus Moraxella is commonly present in the nasal microbiota of swine. Results In this study, 51 isolates of Moraxella were obtained from nasal swabs from 3 to 4 week old piglets, which represented 26 different fingerprintings by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Whole 16S rRNA gene sequencing allowed the identification at species level of the Moraxella spp. isolates. The majority of the field strains were identified as Moraxella pluranimalium, but Moraxella porci was also detected. In addition, a cluster of 7 strains did not group with any described Moraxella species, probably representing a new species. Subsequent phenotypic characterization indicated that strains of Moraxella pluranimalium were mainly sensitive to serum complement, while the cluster representing the putative new species was highly resistant. Biofilm formation capacity was very variable among the Moraxella spp. isolates, while adherence to epithelial cell lines was similar among selected strains. Additionally, variability was also observed in the association of selected strains to porcine alveolar macrophages. Antimicrobial tests evidenced the existence of multidrug-resistance in the strains. Conclusions In summary, phenotypic characterization revealed heterogeneity among Moraxella strains from the nasal cavity of piglets. Strains with pathogenic potential were detected as well as those that may be commensal members of the nasal microbiota. However, the role of Moraxella in porcine diseases and health should be further evaluated.info:eu-repo/semantics/publishedVersio

    Ensinar, avaliar e aprender no ensino superior: perspetivas internacionais

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    Este livro procura dar luz a perspetivas várias, oriundas de diferentes países e contextos, resultando de uma cooperação internacional que reuniu um conjunto diversificado de autores que têm vindo a refletir sobre questões relativas aos desafios que se colocam hoje ao ensino superior, sejam de natureza mais ampla e que surgem na antecâmara da educação superior, sejam as que se despoletam durante a permanência neste nível de ensino, sejam as que despontam à saída, quer tenham a ver com situações de insucesso, do mercado de trabalho ou da profissionalidade
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