Lattice-Based proof of a shuffle

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

Fluxo de Caixa, ADRs e Restrições de Crédito no Brasil

Following Almeida, Campello and Weisbach (2003), we use the link between financial constraints and firm’s demand for liquidity to test the effect of financial constraints on firm policies in Brazil. The effect of financial constraints can be captured by a firm’s propensity to save cash out in addition of cash inflows. While constrained firms should have a positive cash flow sensitivity of cash, unconstrained firms’ cash savings should not be systematically related to cash flows. Using 2SLS method to deal with endogeneity problems, we estimate the cash flow sensitivity of cash using a large sample of Brazilian manufacturing firms over the 1995-2007 period and, using the access to international financial markets trough ADRs as a criterion for financial constraint, we find that firms that are more likely to be financially constrained display a significantly positive cash flow sensitivity of cash, while unconstrained firms do not.Seguindo Almeida, Campello e Weisbach (2003), usamos a relação entre restrição de crédito e a demanda por liquidez para mensurar o efeito das restrições crédito sobre as políticas das empresas brasileiras. O efeito da restrição de crédito pode ser capturado via propensão à poupança de fundos líquidos extraordinários. Enquanto empresas que enfrentam restrições de crédito deveriam apresentar uma sensibilidade positiva à entrada de recursos extraordinários em seu fluxo de caixa, as empresas irrestritas não apresentariam qualquer relação neste sentido. Utilizando o método 2SLS, estimamos a sensibilidade do fluxo de caixa à receitas extraordinárias usando uma amostra de empresas brasileiras entre 1995 e 2007 e, utilizando o acesso ao mercado financeiro internacional através de ADRs, verificamos que as empresas restritas financeiramente apresentam uma sensibilidade positiva do fluxo de caixa à recursos extraordinários, enquanto as empresas irrestritas não se comportam da mesma forma

Alteração do comprimento do passo durante a transposição de obstáculos em tarefas de movimentação de cargas na construção civil

A Construção Civil tem sido o sector que regista maior incidência de acidentes fatais a nível mundial. Diversos estudos têm sido efectuados no sentido de compreender as causas que contribuem para a ocorrência de elevados índices de sinistralidade neste sector. Todavia, o contributo da movimentação manual de cargas, para a ocorrência de quedas na Construção Civil, tem sido descurado. No presente artigo procedeu-se, através de simulação laboratorial, ao estudo da influência da movimentação manual de cargas para a ocorrência de acidentes em operações envolvendo a transposição de obstáculos em obra. Verificou-se que o comprimento de passo e a passada do pé de avanço são alterados com o transporte de carga, aumentando a probabilidade de ocorrência de acidentes envolvendo quedas

The variability behavior of CoRoT M-giant Stars

For 6 years the Convection, Rotation, and Planetary Transits (CoRoT) space mission has acquired photometric data from more than one hundred thousand point sources towards and directly opposite from the inner and outer regions of the Galaxy. The high temporal resolution of the CoRoT data combined with the wide time span of the observations has enabled the study of short and long time variations in unprecedented detail. From the initial sample of 2534 stars classified as M-giants in the CoRoT databasis, we selected 1428 targets that exhibit well defined variability, using visual inspection. The variability period and amplitude of C1 stars (stars having Teff < 4200 K) were computed using Lomb-Scargle and harmonic fit methods. The trends found in the V-I vs J-K color-color diagram are in agreement with standard empirical calibrations for M-giants. The sources located towards the inner regions of the Galaxy are distributed throughout the diagram while the majority of the stars towards the outer regions of the Galaxy are spread between the calibrations of M-giants and the predicted position for Carbon stars. The stars classified as supergiants follow a different sequence from the one found for giant stars. We also performed a KS test of the period and amplitude of stars towards the inner and outer regions of the Galaxy. We obtained a low probability that the two samples come from the same parent distribution. The observed behavior of the period-amplitude and period-Teff diagrams are, in general, in agreement with those found for Kepler sources and ground based photometry, with pulsation being the dominant cause responsible for the observed modulation. We also conclude that short-time variations on M-Giant stars do not exist orare very rare and the few cases we found are possibly related to biases or background stars.Comment: 11 pages, 6 figure

Ocorrência de Coccidoxenoides perminutus (Hymenoptera: Encyrtidae) parasitando Planococcus citri (Hemiptera: Pseudococcidae) em videira no Semiárido brasileiro.

SICONBIOL 2013

Creació d'una eina interactiva per a la consulta d'incidents notificats relacionats amb la seguretat del pacient

Consulta interactiva de dadesConsulta interactiva de datosInteractive query dataIntroducció: Els sistemes de registre d'incidents o riscos relacionats amb la seguretat del pacient ajuden a conèixer la realitat sobre errors o riscos i dissenyar intervencions i estratègies per evitar la seva recurrència o eliminar-los. La Unitat de Seguretat del Pacient de l'Àrea de Salut d'Eivissa i Formentera disposa d'un sistema de notificació d'incidents d'aquest tipus, que inclou variables relacionades amb l'incident com el lloc on passa, número d'història clínica del pacient, professional que ho notifica, factors contribuents, categorització de la gravetat dels incidents, classe d'incident o necessitat de mesures immediates. Material i Mètode: L'anàlisi retrospectiva dels incidents notificats permet tenir una visió global de l'evolució en la notificació dins de l'Àrea, els serveis més actius notificant, així com les àrees en què es requereix una intervenció més profunda i imminent. També permet examinar les classes d'incident més prevalents i les àrees on són més recurrents. Es fa una càrrega dels resultats obtinguts en un full de dades amb les variables relacionades amb els incidents i la configuració de la visualització dels resultats en un programari per a la creació de gràfics interactius. Resultats: Creació d'una eina interactiva de riscos relacionats amb la seguretat del pacient a l'Àrea de salut, amb l'objectiu explorar les variables recollides amb el sistema de notificació. L'usuari té la possibilitat de comparar, filtrar i connectar unes variables amb altres en una línia de temps a través d'una eina de visualització de dades interactiva. Conclusions: Les infografies o gràfics interactius faciliten la presentació de la informació de manera estructurada, atractiva i ràpida d'interpretar, divulgant l'activitat relacionada amb la notificació dins de l'organització de manera visual i didàctica, augmentant la cultura de seguretat i fomentant el compromís dels professionals. Actualment hi ha al mercat eines per a l'elaboració d'eines interactives, que també es repassaran en aquest treball.Los sistemas de registro de incidentes o riesgos relacionados con la seguridad del paciente ayudan a conocer la realidad sobre errores o riesgos y diseñar intervenciones y estrategias para evitar su recurrencia o eliminarlos. La Unidad de Seguridad del Paciente del Área de Salud de Ibiza y Formentera dispone de un sistema de notificación de incidentes de este tipo, que incluye variables relacionadas con el incidente como el lugar donde pasa, número de historia clínica del paciente, profesional que lo notifica, factores contribuyentes, categorización de la gravedad de los incidentes, clase de incidente o necesidad de medidas inmediatas.The incident or risk registry systems related to the patient's safety help to know the reality about errors or risks and to design interventions and strategies to avoid recurrence or eliminate them. The Patient Safety Unit of the Health Area of Eivissa and Formentera has an incident notification system of this type, which includes variables related to the incident, such as the place where it occurs, the history number Patient's clinic, professional who notifies him, contributing factors, categorization of incident severity, incident class or need for immediate measures

Urban food waste for soil amendment? Analysis and characterisation of waste-based compost for soil fertility management in agroecological horticultural production systems in the city of Rosario, Argentina

Urban and peri-urban lands can be an important source of food production for localised and sustainable food systems, however, their soils can be of poor quality, degraded or damaged by anthropic activities, and little is known about their suitability or safety. This paper aims to contribute to this knowledge gap by assessing the soil remediation capacity and qualities of different types of compost made from urban and peri-urban organic wastes for agroecological food production. Prepared over the course of 2021, and used in 2022 for food growing, five different composts were observed and analysed, in two different farms in the city of Rosario, Argentina. Four raw materials generated largely by local industries were used to make the composts: chicken manure, rumen (cow’s stomachs), brewer’s bagasse (byproducts of the beer industry) and urban leaves collected from the municipality waste collection. These were mixed in different proportions (all reaching the 20–30 C/N ratio, typical of quality compost) to produce viable growing substrates where radishes and lettuces were grown. The aim of the study was to assess the possibility, quality and limitations to use locally available organic inputs for soil fertility management in agroecological farming, in the context of urbanisation and to assess pathways to develop closed-cycle agroecological agriculture at metropolitan level. Natural manure substrates (raw and composted) were analysed, as well as crops grown and fertilised with each of the substrates. The attributes and limiting factors of each substrate and their response to local soil conditions were compared and physicochemical, biochemical, and microbiological analyses were performed, including among others, the study of microbial biomass, biological activity, biophytotoxicity, pH, aerobic heterotrophs, nitrogen fixation, and the presence of antibiotics, agrochemicals and heavy metals. The results of the analyses show that all the composted materials improved the physical, chemical and biological properties. However, in some cases, pollutants were present even after composting. Analysis carried out on the vegetables generally indicate undetectable levels or levels below the admissible limits, demonstrating the filtering capacity of the different composts and the soil