A Quantitative Study of Two Attacks

We use a special operational semantics which helps us in predicting quantitative measures on systems describing cryptographic protocols: We also consider a possible attacker. The transitions of the system carry enhanced labels. We assign rates to transitions by only looking at these labels. We then map transition systems to Markov chains and evaluate performance of systems, using standard tools

Pré-tratamento de biomassa microalgácea utilizando enzimas hidrolíticas provenientes de isolados fúngicos

No processo de produção de biogás, utilizando biomassa microalgácea, o principal desafio é a etapa do pré-tratamento, em específico a hidrólise da parede celular. A degradação da matéria orgânica pode ser realizada por enzimas produzidas por diversos microrganismos, principalmente os fungos filamentosos. Entre os processos de pré-tratamento existentes, o biológico mostrou ser o mais economicamente vantajoso e ecologicamente amigável, embora seja diretamente dependente de alguns fatores como, por exemplo, o tempo de hidrólise ou concentração dos extratos fúngicos. O objetivo deste trabalho foi avaliar o pré-tratamento de biomassa microalgácea utilizando enzimas hidrolíticas produzidas por fungos do solo. Foram isolados 21 fungos filamentosos, e avaliado o potencial de produção enzimática extracelular celulásica, lipásica, pectinásica e proteásica. Os 4 isolados com maior atividade foram utilizados para hidrolisar biomassa microalgácea referenciada de Chlorella sp. (crescida em ambiente controlado), e biomassa consorciada derivada de efluente de tratamento anaeróbio. No tratamento com biomassa referenciada, o fungo Trichoderma sp. com atividade proteásica, solubilizou 85,33% de matéria orgânica durante 48 h com 20% de extrato enzimático. Em relação à biomassa consorciada, a atividade proteásica obteve 54,33% de DQOs utilizando o fungo Trichoderma sp. com 20% de extrato enzimático bruto no tempo final de 48 h. Os resultados mostraram que a biomassa microalgácea referenciada foi hidrolisada 66% a mais do que a biomassa consorciada avaliando o parâmetro DQO solubilizado. Através dos resultados, foi possível concluir que a escolha da atividade enzimática e da concentração dos extratos fúngicos podem ser utlizados como chaves para diminuir uma das desvantagens dos tratamentos biológicos, o tempo de hidrólise

Modelling biochemical pathways through enhanced π-calculus

AbstractWe use the π-calculus to model the evolution of biochemical systems, taking advantage of their similarities with global computation applications. First, we present a reduction semantics for the π-calculus from which causality and concurrency can be mechanically derived. We prove that our semantics agrees with the causal definitions presented in the literature. We also extend our semantics to model biological compartments. Then, we show the applicability of our proposal on a couple of biological examples

Petrographic & microstratigraphic analysis of mortar-based building materials from the Temple of Venus, Pompeii.

Recipes for mortar-based building materials may change over time and differ in various construction and restoration phases. They normally reflect craftsmen’s knowledge, availability of raw materials, and also the importance of the building in which they are found. The present research focuses on mortar-based materials from several construction and renovation phases of the Temple of Venus, at Pompeii, Italy, in order to identify any changes over time in production recipes

Study of the reaction of grafting acrylamide onto xanthan gum

AbstractThe present study aimed to study the reaction conditions of grafting of acrylamide on xanthan gum. It was analyzed the influence of reaction conditions, mainly type of initiator activation, initiator concentration and initiator/acrylamide ratio, on graft parameters and copolymer properties. Potassium persulfate was employed as an initiator and heating or N,N,N′,N′-tetramethylethylenediamine was used to activate the initiator. Reaction time and initiator concentration were varied and final values for grafting percentage and grafting efficiency were the same for both methods, whereas speed in reaching these values differs from one technique to another. We found that reaction time was inversely proportional to intrinsic viscosity, likely due to main chain degradation promoted by potassium persulfate (KPS); furthermore, the increasing in the KPS concentration lowers grafting percentage, acrylamide conversion and chain degradation, possibly as a result of O2 formation at high KPS concentrations

Copper deficiency-associated myelopathy in cryptogenic hyperzincemia: A case report

Copper deficiency syndrome is an underestimated cause of posterior myelitis. We describe the case of a 41-year-old woman, who developed a subacute ataxic paraparesis associated with low back pain. Her 3T spine MRI showed a thin hyperintense FS-Echo T2 longitudinally extensive lesion involving the posterior columns of the cervical cord (from C2 to C6). An extensive diagnostic work-up excluded other causes of myelopathy and blood tests pointed out hypocupremia and mild hyperzincemia. Patients affected by this rare form of oligoelement deficiency typically develop progressive posterior column dysfunction with sensory ataxia and spasticity, sometimes associated with sensori-motor polyneuropathy. Clinical and radiological characteristics of posterior myelopathy due to copper deficiency are briefly reviewed. Physicians should be aware of this condition since a prompt introduction of copper supplementation can avoid progression of the neurological damage. (www.actabiomedica.it)

Hardware Implementation of the Spot Payload for Orbiting Objects Detection Using Star Sensors

Space debris issue has become an attractive challenge for many applications in the framework of Space Situational Awareness (SSA) and Space Surveillance and Tracking (SST). The Star sensor image on-board Processing for orbiting Objects deTection (SPOT) fits in this field as an innovative space based autonomous and versatile system for Resident Space Objects’ optical detection via star sensors and for different Earth orbits scenarios. This system is planned to be a payload for an In-Orbit Validation (IOV) activity in the next future. The purpose of this paper is to show the architecture of the SPOT system together with its implementation on a System on Chip (SoC)/Field Programmable Gate Array (FPGA) space representative board. The SPOT algorithms involve several layers of filters which are relatively expensive in terms of computational latency, limiting their applicability to real-time image processing applications. This work presents the design and implementation of SPOT algorithm on the Zynq-7000 SoC using Xilinx FPGA and ARM CPU. Algorithms have been modelled with Simulink and implemented on FPGA using Xilinx system generator with aiming to optimize both processing time and area usage. A Hardware-In-the-Loop (HIL) setup was developed as well, to verify the performances and robustness of the SPOT algorithms and simulating critical scenario by using real night sky images from acquisition campaig

Ileocecal reservoir reconstruction after total mesorectal excision: functional results of the long-term follow-up

Background: The aim of this study is to obtain functional results of the long-term follow-up after TME and ileocecal interposition as rectal replacement. Methods: The study included patients operated on between March 1993 and August 1997 who received an ileocecal interposition as rectal replacement. Follow-up was carried out 3 and 5 years postoperatively. For statistical analysis, the paired t-test, rank test (Wilcoxon), and chi-square or Fisher's exact test were applied; level of significance, P<0.05. Results: Forty-four patients were included in the studies. Of these, five were not available and four patients could not be evaluated (dementia 1, radiation proctitis 1, fistula 1, pouchitis 1). Seventeen patients died during the observation period; 12 died of the disease. Recurrence of the disorder occurred in 2 of 35 patients (5.7%); 26 and 18 patients, 3 and 5 years postoperatively, respectively remained in the study. At 5 years, 78% of the patients were continent; mean stool frequency was 2.5±1.6 per day. Conclusions: Functional results and subjective assessment of ileocecal interposition were constant at 3 and 5 years postoperatively. If construction of a colonic J-pouch is not possible due to lack of colonic length, especially after prior colonic resections, the ileocecal interpositional reservoir may offer an alternative to rectal replacemen

Oxidation-reduction potentials of D-amino acid oxidase.

Abstract This paper reports a study of the oxidation-reduction equilibrium of d-amino acid oxidase, a flavoprotein containing FAD. The oxidation-reduction potential at 50% oxidation (E½) is -0.004 volt at pH 7.0 and 20°, and therefore about 180 mv higher than that of the free coenzyme (FAD). This difference in oxidation-reduction potential may be described in terms of relative affinity of the apoenzyme for the reduced and oxidized forms of the coenzyme. On this basis the affinity constant for the binding of reduced FAD to the apoenzyme is about 106 higher than that of oxidized FAD. The curve relating E½ to pH is in the alkaline range consistent with a slope of about -0.058 volt per pH unit which corresponds to the difference of 1 proton between the oxidized and reduced forms of the enzyme. The apparent pK of the oxidation-linke group, which belongs to the oxidized form, is ∼7.1. The shape of the oxidation-reduction equilibrium curve of d-amino acid oxidase is pH dependent, the value of n increasing from about 1 at pH 8.6 to about 3, or more, at pH 6.6. Under these conditions, therefore, one must consider the existence of functional homotropic interactions between at least 2 FAD molecules. The pH dependence of the cooperative oxidation-reduction equilibrium is discussed in the framework of the theory of linked functions