Timed Consistent Network Updates

Network updates such as policy and routing changes occur frequently in Software Defined Networks (SDN). Updates should be performed consistently, preventing temporary disruptions, and should require as little overhead as possible. Scalability is increasingly becoming an essential requirement in SDN. In this paper we propose to use time-triggered network updates to achieve consistent updates. Our proposed solution requires lower overhead than existing update approaches, without compromising the consistency during the update. We demonstrate that accurate time enables far more scalable consistent updates in SDN than previously available. In addition, it provides the SDN programmer with fine-grained control over the tradeoff between consistency and scalability.Comment: This technical report is an extended version of the paper "Timed Consistent Network Updates", which was accepted to the ACM SIGCOMM Symposium on SDN Research (SOSR) '15, Santa Clara, CA, US, June 201

Smart Plastic Antibody Material for Hemoglobin Tailored by Silica Surface Imprinting and with Charged Binding Sites: Its use as Ionophore in Potentiometric Transduction

JORNADAS DE ELECTROQUÍMICA E INOVAÇÃO 2013Human hemoglobin (Hb) is a globular metalloprotein, present in the blood and involved in gas transport. Hb-associated disturbances are related to several diseases, such thalassemia, anemia, heart disease and leukemia, or to side-effects from other diseases, such as cancer. Overall, it is of great importance to know the concentration of Hb in the blood in many health-related conditions. There are many methods described in the literature for determining Hb. Most of these rely on antibody/antigen interactions, due to the high selectivity of the affinity reaction taking place between these biomolecules. However, the use of antibodies for Hb determination in routine clinical use is very expensive, due to the high cost of the material, the need for special handling and storage, and the non-reusability. These constraints may be limited by replacing natural antibodies by plastic receptors, obtained by molecular imprinting procedures. Thus, this work describes a novel smart plastic antibody material (SPAM) by surface imprinting technique for the detection of Hb and its application to design small, portable and low cost potentiometric devices. The SPAM material was obtained by linking Hb to silica nanoparticles and allowing its subsequent interaction with different vinyl monomers, of different chemical functions and ionic charges. Control materials were designed in parallel to assess the ability of establishing stereochemical recognition of Hb and the effect of the kind/charge of the monomers employed. Scanning Electron Microscopy analysis confirmed the surface modification of the silica material used for imprint. All materials were mixed with PVC/plasticizer and applied as selective membranes in potentiometric transduction. Suitable emf variations were detected only for selective membranes having a SPAM material and a charged lipophilic anionic additive. All control materials were unable to produce a potentiometric response. Overall, good features were obtained for SPAM-based selective membranes carrying an anionic lipophilic additive. In HEPES buffer of pH 5, limits of detection were 43.8μg/mL for a linear response after 83.8μg/mL with a cationic slope of +40.4mV/decade. Good selectivity was also observed against other coexisting biomolecules. The analytical application was conducted successfully, showing accurate and precise results

Sampling system for wheat (Triticum aestivum L) area estimation using digital LANDSAT MSS data and aerial photographs

A procedure to estimate wheat (Triticum aestivum L) area using sampling technique based on aerial photographs and digital LANDSAT MSS data is developed. Aerial photographs covering 720 square km are visually analyzed. To estimate wheat area, a regression approach is applied using different sample sizes and various sampling units. As the size of sampling unit decreased, the percentage of sampled area required to obtain similar estimation performance also decreased. The lowest percentage of the area sampled for wheat estimation with relatively high precision and accuracy through regression estimation is 13.90% using 10 square km as the sampling unit. Wheat area estimation using only aerial photographs is less precise and accurate than those obtained by regression estimation

Collaboration networks from a large CV database: dynamics, topology and bonus impact

Understanding the dynamics of research production and collaboration may reveal better strategies for scientific careers, academic institutions and funding agencies. Here we propose the use of a large and multidisciplinar database of scientific curricula in Brazil, namely, the Lattes Platform, to study patterns of scientific production and collaboration. In this database, detailed information about publications and researchers are made available by themselves so that coauthorship is unambiguous and individuals can be evaluated by scientific productivity, geographical location and field of expertise. Our results show that the collaboration network is growing exponentially for the last three decades, with a distribution of number of collaborators per researcher that approaches a power-law as the network gets older. Moreover, both the distributions of number of collaborators and production per researcher obey power-law behaviors, regardless of the geographical location or field, suggesting that the same universal mechanism might be responsible for network growth and productivity.We also show that the collaboration network under investigation displays a typical assortative mixing behavior, where teeming researchers (i.e., with high degree) tend to collaborate with others alike. Finally, our analysis reveals that the distinctive collaboration profile of researchers awarded with governmental scholarships suggests a strong bonus impact on their productivity.Comment: 8 pages, 8 figure

On the name of the lepidophagous characid fish Roeboexodon guyanensis (Puyo) (Teleostei: Characiformes: Characidae)

The arguments for the usage of the names Gnathoplax, Roeboexodon, R. geryi, and R. guyanensis are revised. Based on the literature and museum specimens, we recommend that the neotype of Exodon guyanensis should be considered valid; that the genus Gnathoplax should be considered an objective junior synonym of Roeboexodon; and that Roeboexodon geryi should be considered an objective junior synonym of Exodonguyanensis.Os argumentos para o uso dos nomes Gnathoplax, Roeboexodon, R. geryi e R. guyanensis são reavaliados. Baseados na literatura e em espécimes de museu, recomendamos que o neótipo de Exodonguyanensis seja considerado válido, que o gênero Gnathoplax seja considerado sinônimo objetivo júnior de Roeboexodon e que Roeboexodon geryi seja considerado sinônimo objetivo júnior de Exodon guyanensis.Universidade Federal de São Paulo (UNIFESP) Departamento de Ciências BiológicasUniversidade de São Paulo Museu de ZoologiaUNIFESP, Depto. de Ciências BiológicasSciEL

Resonant x-ray scattering study on multiferroic BiMnO3

Resonant x-ray scattering is performed near the Mn K-absorption edge for an epitaxial thin film of BiMnO3. The azimuthal angle dependence of the resonant (003) peak (in monoclinic indices) is measured with different photon polarizations; for the $\sigma\to\pi'$ channel a 3-fold symmetric oscillation is observed in the intensity variation, while the $\sigma\to\sigma'$ scattering intensity remains constant. These features are accounted for in terms of the peculiar ordering of the manganese 3d orbitals in BiMnO3. It is demonstrated that the resonant peak persists up to 770 K with an anomaly around 440 K; these high and low temperatures coincide with the structural transition temperatures, seen in bulk, with and without a symmetry change, respectively. A possible relationship of the orbital order with the ferroelectricity of the system is discussed.Comment: 14 pages, 4 figure

Protein intake and obesity in schoolchildren

[resumo]Resumo de comunicação apresentada em: 16th European Congress on Obesity - ECO 2008; 2008 Mai 14-17; Genebra, Suíça

Manifestation of finite temperature size effects in nanogranular magnetic graphite

In addition to the double phase transition (with the Curie temperatures T_C=300K and T_{Ct}=144K), a low-temperature anomaly in the dependence of the magnetization is observed in the bulk magnetic graphite (with an average granular size of L=10nm), which is attributed to manifestation of the size effects below the quantum temperature. The best fits of the high-temperature data (using the mean-field Curie-Weiss and Bloch expressions) produced reasonable estimates for the model parameters, such as defects mediated effective spin exchange energy J=12meV (which defines the intragranular Curie temperature T_C) and proximity mediated interactions between neighboring grains (through potential barriers created by thin layers of non-magnetic graphite) with energy J_t=exp(-d/s)J=5.8meV (which defines the intergranular Curie temperature T_{Ct}) with d=1.5nm and s=2nm being the intergranular distance and characteristic length, respectively