Hydrophobic/hydrophilic P(VDF-TrFE)/PHEA polymer blend membranes

Polymer blend membranes have been obtained consisting of a hydrophilic and a hydrophobic polymers distributed in co-continuous phases. In order to obtain stable membranes in aqueous environments, the hydrophilic phase is formed by a poly(hydrohyethyl acrylate), PHEA, network while the hydrophobic phase is formed by poly(vinylidene fluoride-co-trifluoroethylene) P(VDF-TrFE). To obtain the composites, in a first stage, P(VDF-TrFE) is blended with poly(ethylene oxyde) (PEO), the latter used as sacrificial porogen. P(VDF-TrFE)/PEO blend membranes were prepared by solvent casting at 70° followed by cooling to room temperature. Then PEO is removed from the membrane by immersion in water obtaining a P(VDF-TrFE) porous membrane. After removing of the PEO polymer, a P(VDF-TrFE) membrane results in which pores are collapsed. Nevertheless the pores reopen when a mixture of hydroxethyl acrylate (HEA) monomer, ethyleneglycol dimethacrylate (as crosslinker) and ethanol (as diluent) is absorbed in the membrane and subsequent polymerization yields hybrid hydrophilic/hydrophobic membranes with controlled porosity. The membranes are thus suitable for lithium-ion battery separator membranes and/or biostable supports for cell culture in biomedical applications.

Constituintes químicos fixos e voláteis dos talos e frutos de Piper tuberculatum Jacq. e das raízes de P. hispidum H. B. K.

Os óleos essenciais dos frutos e talos finos de Piper tuberculatum e das raízes de P. hispidum, coletados no estado de Rondônia, foram obtidos por hidrodestilação e analisados por GC e GC-MS. Foram identificados como constituintes majoritários, nos óleos dos frutos e talos finos de P. tuberculatum, o óxido de cariofileno (32,1%) e (26,6%) e o (E)-cariofileno (17,7%) e (12,3%), respectivamente. No óleo essencial das raízes de P. hispidum, foram identificados, como constituintes majoritários, o dilapiol (57,5%), a elemicina (24,5%) e o apiol (10,2%). Do extrato etanólico dos frutos de P. tuberculatum, foram isolados os esteróides β-sitosterol e estigmasterol, as amidas piplartina e dihidropiplartina e um derivado do ácido cinâmico, o ácido 3,4,5-trimetoxi-dihidrocinâmico.

Validade comercial e aceitabilidade da carne de tartaruga-da-amazônia (P.expansa)

Esse experimento foi elaborado em parceria com o CENAQUA (Centro Nacional de Quelônios do Amazonas) e a Pró-Fauna (localizada em Iguape - SP) objetivando o estudo da validade comercial e a aceitabilidade da carne de tartaruga-da-amazônia criada em cativeiro. Foi avaliado o efeito do tempo de estocagem de amostras de carne de 14 tartarugas (7 fêmeas e 7 machos) nos dias 01, 30, 60 e 120, estocadas a -10 ºC, nos valores de pH e de Bases Voláteis Totais (BVT), cor, textura, odor e prova de cocção. Observou-se diferença significativa entre os valores de pH em relação ao tempo de estocagem nos dias 01 (5,81 e 5,81), 30 (6,04 e 6,05), 60 (6,22 e 6,23) e 120 (6,30 e 6,30), respectivamente para a carne das fêmeas e machos. Entre os sexos não houve diferença significativa. Quanto a BVT o tempo de estocagem influenciou significativamente entre os dias 01 (11,34 e 11,74 g/100g), 30 (13,92 e 13,90 g/100g) e 120 (17,62 e 17,82 g/100g); entre os dias 30 (13,92 e 13,90 g/100g) e 60 (14,02 e 14,06 g/100g) não observou-se diferença significativa, respectivamente para a carne de fêmeas e machos. Entre os sexos não ocorreu diferenças significativas. A cor, textura, odor e a prova de cocção não apresentaram alteração ao longo do tempo de estocagem. A carne de tartaruga obteve media de aceitabilidade global de 7,04. De acordo com os resultados obtidos concluímos que, pelas provas de pH e BVT, a carne de tartaruga pode ter uma validade comercial de 120 dias, quando embaladas a vácuo e estocadas a -10 ºC, e que a os provadores gostaram muito desse tipo de carne.

Potencial de resposta à adubação para N, P, K, Ca e Mg em cupuaçueiros avaliados por diferentes normas DRIS

O potencial de resposta à adubação é uma ferramenta utilizada para a interpretação dos valores dos índices DRIS, de forma que pode ser útil para verificar se diferentes grupos de normas resultam em diagnósticos distintos ou semelhantes entre si. Neste sentido, objetivou-se avaliar o comportamento do diagnóstico nutricional, submetidos a cinco grupos de normas DRIS. Para isto, amostras foliares de cupuaçueiros foram coletadas de pomares comerciais, cuja idade das plantas variou de 5 a 18 anos, sob monocultivo e sistemas agroflorestais (SAF's), obtendo-se para cada relação nutricional entre os nutrientes N, P, K, Ca, Mg, as normas DRIS bivariadas, as quais foram obtidas para o conjunto das populações monitoradas e para subpopulações específicas. As diferentes normas DRIS resultaram em diagnósticos semelhantes para N, P e Ca, enquanto que para K e Mg os diagnósticos produzidos distinguiram-se entre as normas resultando em desvios nutricionais.

Record of the freshwater stingrays Potamotrygon brachyura and P. motoro (Chondrichthyes, Potamotrygonidae) in the lower Uruguay river, South America

Freshwater stingrays, or potamotrygonids, are restricted to Neotropical river drainages. These elasmobranchs are well adapted to freshwater environments and the number of described species gradually increases as further research is carried out. Some of the first studies on their systematics and natural history were carried out in the 1960s and 1970s in southern South America. However, there is no new published data on potamotrygonids from Uruguayan waters since then (except for local journal reports from sportive fishermen and specimens deposited in Uruguayan collections). The present study aims to record the recent occurrence of two species of potamotrygonids caught by sport fishermen, with comments on other published historical records for the same area. As many other elasmobranchs, these species have an important, but not always well understood, role in the Uruguayan rivers ecosystems.

Caracterização farmacognóstica de Piper arboreum var. arboreum e P. tuberculatum (Piperaceae)

RESUMO Piper arboreum Aubl. var. arboreum e P. tuberculatum Jacq. (Piperaceae), conhecidas como pimenta-longa, são comercializadas como produtos tradicionais fitoterápicos e, frequentemente, identificadas erroneamente, não havendo relatos sobre controle de qualidade dessas espécies. O objetivo do trabalho foi preparar e caracterizar drogas vegetais foliares e caulinares dessas espécies para estabelecer-lhes parâmetros de autenticidade botânica e grau de pureza para o controle de qualidade. Foram utilizados métodos padrões para o preparo e análises estrutural e físico-química das drogas vegetais. São caracteres diagnósticos macroscópicos para distinguir as drogas vegetais íntegras: tamanho, forma, cor, sabor, textura, características da superfície de fratura e da secção transversal e os padrões de venação foliar. São caracteres diagnósticos para distinguir as drogas vegetais pulverizadas: padrões de cutícula e cera epicuticular, tipos de tricoma e espessamento parietal dos elementos traqueais e a forma do hilo dos grãos de amido. Emergências são marcadores morfológicos chave para as drogas vegetais de P. tuberculatum. Os valores dos parâmetros físico-químicos foram similares nas drogas vegetais das espécies, exceto o de cinzas ácido-insolúveis que foi maior nas drogas vegetais caulinares de P. arboreum var. arboreum. As maiores concentrações de metais ocorreram nas drogas vegetais de P. arboreum var. arboreum. As concentrações mais elevadas foram de Al, Cu, Mn e V e as mais baixas de Cd, Co e Hg. Os resultados obtidos poderão ser utilizados como parâmetros de controle de qualidade para as drogas vegetais de ambas as espécies.

Vanishing spin stiffness in the spin-1/2 Heisenberg chain for any nonzero temperature

Whether at the zero spin density m = 0 and finite temperatures T > 0 the spin stiffness of the spin-1/2 XXX chain is finite or vanishes remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we explicitly compute the stiffness at m = 0 and find strong evidence that it vanishes. In particular, we derive an upper bound on the stiffness within a canonical ensemble at any fixed value of spin density m that is proportional to m2L in the thermodynamic limit of chain length L → ∞, for any finite, nonzero temperature, which implies the absence of ballistic transport for T > 0 for m = 0. Although our method relies in part on the thermodynamic Bethe ansatz (TBA), it does not evaluate the stiffness through the second derivative of the TBA energy eigenvalues relative to a uniform vector potential. Moreover, we provide strong evidence that in the thermodynamic limit the upper bounds on the spin current and stiffness used in our derivation remain valid under string deviations. Our results also provide strong evidence that in the thermodynamic limit the TBA method used by X. Zotos [Phys. Rev. Lett. 82, 1764 (1999)] leads to the exact stiffness values at finite temperature T > 0 for models whose stiffness is finite at T = 0, similar to the spin stiffness of the spin-1/2 Heisenberg chain but unlike the charge stiffness of the half-filled 1D Hubbard model.

Measurement of differential J/psi production cross sections and forward-backward ratios in p plus Pb collisions with the ATLAS detector

Measurements of differential cross sections for J/ψ production in p+Pb collisions at sNN−−−−√=5.02 TeV at the CERN Large Hadron Collider with the ATLAS detector are presented. The data set used corresponds to an integrated luminosity of 28.1 nb−1. The J/ψ mesons are reconstructed in the dimuon decay channel over the transverse momentum range 8<pT<30GeV and over the center-of-mass rapidity range −2.87Prompt J/ψ are separated from J/ψ resulting from b-hadron decays through an analysis of the distance between the J/ψ decay vertex and the event primary vertex. The differential cross section for production of nonprompt J/ψ is compared to a FONLL calculation that does not include nuclear effects. Forward-backward production ratios are presented and compared to theoretical predictions. These results complement previously published results by covering a region of higher transverse momentum and more central rapidity. They thus constrain the kinematic dependence of nuclear modifications of charmonium and b-quark production in p+Pb collisions.

Z boson production in p plus Pb collisions at root S-NN=5.02 TeV measured with the ATLAS detector

The ATLAS Collaboration measures the inclusive production of Z bosons via their decays into electron and muon pairs in p+Pb collisions at sNN−−−√=5.02TeV at the Large Hadron Collider. The measurements are made using data corresponding to integrated luminosities of 29.4 and 28.1 nb−1 for Z→ee and Z→μμ, respectively. The results from the two channels are consistent and combined to obtain a cross section times the Z→ℓℓ branching ratio, integrated over the rapidity region ∣∣y∗Z|<3.5, of 139.8±4.8(statistical)±6.2(systematic)±3.8 (luminosity) nb. Differential cross sections are presented as functions of the Z boson rapidity and transverse momentum and compared with models based on parton distributions both with and without nuclear corrections. The centrality dependence of Z boson production in p+Pb collisions is measured and analyzed within the framework of a standard Glauber model and the model's extension for fluctuations of the underlying nucleon-nucleon scattering cross section.

Concise server-wide causality management for eventually consistent data stores

Large scale distributed data stores rely on optimistic replication to scale and remain highly available in the face of net work partitions. Managing data without coordination results in eventually consistent data stores that allow for concurrent data updates. These systems often use anti-entropy mechanisms (like Merkle Trees) to detect and repair divergent data versions across nodes. However, in practice hash-based data structures are too expensive for large amounts of data and create too many false conflicts. Another aspect of eventual consistency is detecting write conflicts. Logical clocks are often used to track data causality, necessary to detect causally concurrent writes on the same key. However, there is a nonnegligible metadata overhead per key, which also keeps growing with time, proportional with the node churn rate. Another challenge is deleting keys while respecting causality: while the values can be deleted, perkey metadata cannot be permanently removed without coordination. Weintroduceanewcausalitymanagementframeworkforeventuallyconsistentdatastores,thatleveragesnodelogicalclocks(BitmappedVersion Vectors) and a new key logical clock (Dotted Causal Container) to provides advantages on multiple fronts: 1) a new efficient and lightweight anti-entropy mechanism; 2) greatly reduced per-key causality metadata size; 3) accurate key deletes without permanent metadata.

Ancestry of the Brazilian TP53 c.1010G>A (p.Arg337His, R337H) founder mutation : clues from haplotyping of short tandem repeats on Chromosome 17p

Rare germline mutations in TP53 (17p13.1) cause a highly penetrant predisposition to a specific spectrum of early cancers, defining the Li-Fraumeni Syndrome (LFS). A germline mutation at codon 337 (p.Arg337His, c1010G>A) is found in about 0.3% of the population of Southern Brazil. This mutation is associated with partially penetrant LFS traits and is found in the germline of patients with early cancers of the LFS spectrum unselected for familial his- tory. To characterize the extended haplotypes carrying the mutation, we have genotyped 9 short tandem repeats on chromosome 17p in 12 trios of Brazilian p.Arg337His carriers. Results confirm that all share a common ancestor haplotype of Caucasian/Portuguese-Ibe- ric origin, distant in about 72–84 generations (2000 years assuming a 25 years intergenera- tional distance) and thus pre-dating European migration to Brazil. So far, the founder p. Arg337His haplotype has not been detected outside Brazil, with the exception of two resi- dents of Portugal, one of them of Brazilian origin. On the other hand, increased meiotic recombination in p.Arg337His carriers may account for higher than expected haplotype diversity. Further studies comparing haplotypes in populations of Brazil and of other areas of Portuguese migration are needed to understand the historical context of this mutation in Brazil.

Blow-up and finite time extinction for p(x, t)-curl systems arising in electromagnetism

"Available online 22 March 2016"

An evolutionary approach to the use of Petri net based models: from parallel controllers to HW/SW co-design

"A workshop within the 19th International Conference on Applications and Theory of Petri Nets - ICATPN’1998"