Detection of high-velocity material from the wind-wind collision zone of Eta Carinae across the 2009.0 periastron passage

We report near-infrared spectroscopic observations of the Eta Carinae massive binary system during 2008-2009 using the CRIRES spectrograph mounted on the 8m UT 1 Very Large Telescope (VLT Antu). We detect a strong, broad absorption wing in He I lambda 10833 extending up to -1900 km s(-1) across the 2009.0 spectroscopic event. Analysis of archival Hubble Space Telescope/Space Telescope Imaging Spectrograph ultraviolet and optical data identifies a similar high-velocity absorption (up to -2100 km s(-1)) in the ultraviolet resonance lines of Si IV lambda lambda 1394, 1403 across the 2003.5 event. Ultraviolet resonance lines from low-ionization species, such as Si II lambda lambda 1527, 1533 and CII lambda lambda 1334, 1335, show absorption only up to -1200 km s(-1), indicating that the absorption with velocities -1200 to -2100 km s(-1) originates in a region markedly more rapidly moving and more ionized than the nominal wind of the primary star. Seeing-limited observations obtained at the 1.6m OPD/LNA telescope during the last four spectroscopic cycles of Eta Carinae (1989-2009) also show high-velocity absorption in He I lambda 10833 during periastron. Based on the large OPD/LNA dataset, we determine that material with velocities more negative than -900 km s(-1) is present in the phase range 0.976 <= phi <= 1.023 of the spectroscopic cycle, but absent in spectra taken at phi <= 0.947 and phi >= 1.049. Therefore, we constrain the duration of the high-velocity absorption to be 95 to 206 days (or 0.047 to 0.102 in phase). We propose that the high-velocity absorption component originates in shocked gas in the wind-wind collision zone, at distances of 15 to 45 AU in the line-of-sight to the primary star. With the aid of three-dimensional hydrodynamical simulations of the wind-wind collision zone, we find that the dense high-velocity gas is along the line-of-sight to the primary star only if the binary system is oriented in the sky such that the companion is behind the primary star during periastron, corresponding to a longitude of periastron of omega similar to 240 degrees-270 degrees. We study a possible tilt of the orbital plane relative to the Homunculus equatorial plane and conclude that our data are broadly consistent with orbital inclinations in the range i = 40 degrees-60 degrees.

Volumetric reconstruction of the mean flow around circular cylinders fitted with strakes

The volumetric reconstruction technique presented in this paper employs a two-camera stereoscopic particle image velocimetry (SPIV) system in order to reconstruct the mean flow behind a fixed cylinder fitted with helical strakes, which are commonly used to suppress vortex-induced vibrations (VIV). The technique is based on the measurement of velocity fields at equivalent adjacent planes that results in pseudo volumetric fields. The main advantage over proper volumetric techniques is the avoidance of additional equipment and complexity. The averaged velocity fields behind the straked cylinders and the geometrical periodicity of the three-start configuration are used to further simplify the reconstruction process. Two straked cylindrical models with the same pitch (p = 10d) and two different heights (h = 0.1 and 0.2d) are tested. The reconstructed flow shows that the strakes introduce in the wake flow a well-defined wavelength of one-third of the pitch. Measurements of hydrodynamic forces, fluctuating velocity, vortex formation length, and vortex shedding frequency show the interdependence of the wake parameters. The vortex formation length is increased by the strakes, which is an important effect for the suppression of vortex-induced vibrations. The results presented complement previous investigations concerning the effectiveness of strakes as VIV suppressors and provide a basis of comparison to numerical simulations.

On the solubility of proteins as a function of pH: Mathematical development and application

Thermodynamic relations between the solubility of a protein and the solution pH are presented in this work. The hypotheses behind the development are that the protein chemical potential in liquid phase can be described by Henry`s law and that the solid-liquid equilibrium is established only between neutral molecules. The mathematical development results in an analytical expression of the solubility curve, as a function of the ionization equilibrium constants, the pH and the solubility at the isoelectric point. It is shown that the same equation can be obtained either by directly calculating the fraction of neutral protein molecules or by integrating the curve of the protein average charge. The methodology was successfully applied to the description of the solubility of porcine insulin as a function of pH at three different temperatures and of bovine beta-lactoglobulin at four different ionic strengths. (C) 2011 Elsevier B.V. All rights reserved.

Development of a digital hearing aid to meet the Brazilian Government`s Ordinance 587 (APAC) - Health Department

The treatment of sensorineural hearing loss is based on hearing aids, also known as individual sound amplification devices. The hearing aids purchased by the Brazilian Government, aiming at fulfilling public policies, are based on dedicated components, which bring about benefits, but also render them expensive and may impair repair services after manufacture`s warranty expires. Aim: to design digital behind-the-ear hearing aids built from standardized components coming from the very supply chain of these manufacturers. Study design: experimental. Materials and Methods: to identify the supply chain of these manufacturers, request samples and set up hearing aids in the laboratory. Results: The developed hearing aids did not show lesser electroacoustic characteristics when compared to those acquired by the Government, also being tested by the same reference international technical standard. Conclusion: It is possible to develop digital behind-the-ear hearing aids based on off-the-shelf components from hearing aid manufacturers` supply chain. Their advantages include low operational costs - for acquisition (with clear advantages for the Government) and service (advantage for the patient).

Nasal allergies in the Latin American population: Results from the Allergies in Latin America survey

Allergies in Latin America is the first cross-national survey that describes the symptoms, impact, and treatment of nasal allergies (NAs) in individuals >= 4 years old in Latin America (LA). In total, 22,012 households across the Latin American countries of Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Peru, and Venezuela were screened for children, adolescents, and adults with a diagnosis of NA and either symptoms or treatment in the past 12 months. A total of 1088 adults and 457 children and adolescents were included and the sample was probability based to ensure valid statistical inference to the population. Approximately 7% of the LA population was diagnosed with NAs with two of three respondents stating that their allergies were seasonal or intermittent in nature. A general practice physician or otolaryngologist diagnosed the majority of individuals surveyed. Nasal congestion was the most common and bothersome symptom of NAs. Sufferers indicated that their symptoms affected productivity and sleep and had a negative impact on quality of life. Two-thirds of patients reported taking some type of medication for their NAs, with a roughly equal percentage of patients reporting taking over-the-counter versus prescription medications. Changing medications was most commonly done in those reporting inadequate efficacy. The most common reasons cited for dissatisfaction with current medications were related to inadequate effectiveness, effectiveness wearing off with chronic use, failure to provide 24-hour relief, and bothersome side effects (e.g., unpleasant taste and retrograde drainage into the esophagus). Findings from this cross-national survey on NAs have confirmed a high prevalence of physician-diagnosed NAs and a considerable negative impact on daily quality of life and work productivity as well as substantial disease management challenges in LA. Through identification of disease impact on the LA population and further defining treatment gaps, clinicians in LA may better understand and treat NAs, thus leading to improvements in overall patient satisfaction and quality of life. (Allergy Asthma Proc 31:S9-S27, 2010; doi: 10.2500/aap.2010.31.3347)

A numerical method for solving the dynamic three-dimensional Ericksen-Leslie equations for nematic liquid crystals subject to a strong magnetic field

A finite difference technique, based on a projection method, is developed for solving the dynamic three-dimensional Ericksen-Leslie equations for nematic liquid crystals subject to a strong magnetic field. The governing equations in this situation are derived using primitive variables and are solved using the ideas behind the GENSMAC methodology (Tome and McKee [32]; Tome et al. [34]). The resulting numerical technique is then validated by comparing the numerical solution against an analytic solution for steady three-dimensional flow between two-parallel plates subject to a strong magnetic field. The validated code is then employed to solve channel flow for which there is no analytic solution. (C) 2009 Elsevier B.V. All rights reserved.

Influence from the sulfonate group (RSO(3)(-)) on the conversion process and emission efficiency of poly(p-phenylene vinylene)

The discovery of an alternative route to convert poly(xylyliden tetrahydrothiophenium chloride) (PTHT) into poly(p-phenylene vinylene) (PPV) using dodecylbenzenesulfonate (DBS) has allowed the formation of ultrathin films with unprecedented control of architecture and emission properties. In this work, we show that this route may be performed with several sufonated compounds where RSO(3)(-) replaces the counter-ion (Cl(-)) of PTHT, some of which are even more efficient than DBS. Spin-coating films were produced from PTHT and azo-dye molecules, an azo-polymer and organic salts as counter-ions of PTHT. The effects of the thermal annealing step of PTHT/RSO(3)(-) films at 110 and 230 degrees C were monitored by measuring the absorption and emission spectra. The results indicate that the exchange of the counterion Cl(-) of PTHT by a linear long chain with RSO(3)(-) group is a general procedure to obtain PPV polymer at lower conversion temperature (ca. 110 degrees C) with significant increase in the emission efficiency, regardless of the chemical position and the number of sulfonate groups. With the enhanced emission caused by Congo Red and Tinopal as counter-ions, it is demonstrated that the new synthetic route is entirely generic, which may allow accurate control of conversion and emission properties. (C) 2010 Elsevier B.V. All rights reserved.

Structural-electronic aspects related to the near-infrared light emission of Fe-doped silicon films

The need of efficient (fast and low consumption) optoelectronic devices has always been the driving force behind the investigation of materials with new or improved properties. To be commercially attractive, however, these materials should be compatible with our current micro-electronics industry and/or telecommunications system. Silicon-based compounds, with their matured processing technology and natural abundance, partially comply with such requirements-as long as they emit light. Motivated by these issues, this work reports on the optical properties of amorphous Si films doped with Fe. The films were prepared by sputtering a Si+Fe target and were investigated by different spectroscopic techniques. According to the experimental results, both the Fe concentration and the thermal annealing of the samples induce changes in their atomic structure and optical-electronic properties. In fact, after thermal annealing at similar to 750 degrees C, the samples partially crystallize with the development of Si and/or beta-FeSi(2) crystallites. In such a case, certain samples present light emission at similar to 1500 nm that depends on the presence of beta-FeSi(2) crystallites and is very sensitive to the annealing conditions. The most likely reasons for the light emission (or absence of it) in the considered Fe-doped Si samples are presented and discussed in view of their main structural-electronic characteristics. (C) 2011 Elsevier Ltd. All rights reserved.

A casa e a roça: socioeconomia, demografia e agricultura em populações quilombolas do Vale do Ribeira, São Paulo, Brasil

Este estudo tem como objetivos caracterizar o perfil demográfico e socioeconômico de nove comunidades remanescentes de quilombos no vale do Ribeira, estado de São Paulo, e identificar os principais fatores responsáveis pelas mudanças recentes nos seus padrões de subsistência. Desde a formação das primeiras aglomerações de escravos libertos e foragidos no século XVIII, as relações estabelecidas entre estas populações com as cidades próximas e com o mercado regional têm vivenciado momentos de retração e de expansão, adaptando-se e ajustando-se a novas mudanças políticas e socioeconômicas. Nas últimas cinco décadas, o impacto de fatores externos na aceleração das mudanças nos padrões de subsistência locais parece ter tido um aumento significativo. Os resultados mostram que as restrições impostas pela legislação ambiental, os conflitos de terra, a construção de uma rodovia na região, a crescente inserção no mercado regional e a atuação de órgãos governamentais e não-governamentais de desenvolvimento são os principais fatores responsáveis pelas mudanças observadas no sistema agrícola de corte e queima e, conseqüentemente, na organização socioeconômica destas populações.

A dimensão criadora no trabalho docente: subsídios para a formação de professores alfabetizadores

Este artigo tem como objetivo evidenciar a dimensão criadora dos saberes docentes mobilizados por uma professora alfabetizadora, a partir da concepção de saberes docentes desenvolvida pela teoria histórico-cultural. A pesquisa realizou-se em escola pública, no estado de Rondônia, por meio de uma abordagem etnográfica. O trabalho traz para a análise duas cenas recortadas do cotidiano escolar para exemplificar como os saberes docentes são alterados e recriados no enfrentamento dos desafios impostos pela prática pedagógica. Os resultados permitem compreender que a prática docente no cotidiano não se caracteriza apenas como reprodução de modelos ou propostas utilizadas por outros profissionais. Ao contrário, no encontro de uma professora e uma turma de alunos há sempre certa originalidade que demanda a criação de formas específicas de intervenção para aquele grupo, nas condições do contexto. Acompanhar o trabalho da professora durante o período de pesquisa permitiu compreender que há inúmeras possibilidades de condução do trabalho pedagógico e as razões que motivam as escolhas dos professores e das professoras estão fundamentadas em saberes construídos ao longo de suas experiências de formação e atuação. Considera-se, portanto, que as práticas pedagógicas precisam ser conhecidas e estudadas para que se possa compreendê-las, mais do que avaliá-las, tendo-se em vista a contribuição desses estudos para a formação docente.

A Equação-Mestra: atingindo o equilíbrio

In the last years, a great interest in nonequilibrium systems has been witnessed. Although the Master Equations are one of the most common methods used to describe these systems, the literature about these equations is not straightforward due to the mathematical framework used in their derivations. The goals of this work are to present the physical concepts behind the Master Equations development and to discuss their basic proprieties via a matrix approach. It is also shown how the Master Equations can be used to model typical nonequilibrium processes like multi-wells chemical reactions and radiation absorption processes.

Novos táxons e novo registro em Hemilophini (Coleoptera: Cerambycidae: Lamiinae)

Novas espécies descritas e ilustradas: Adesmus nigrolineatus sp. nov. do México (Oaxaca). Da Costa Rica: A. moruna sp. nov. (Heredia); Corcovado bezarki sp. nov. (Guanacaste); Alampyris fuscus sp. nov. (Guanacaste), Cariua gen. nov. espécie-tipo C. sulphurea sp. nov., (Guanacaste). Da Bolívia: Phoebemima albomaculata sp. nov. (Cochabamba); Ipepo gen. nov. espécie-tipo I. dilatatus sp. nov. (Santa Cruz). Do Brasil: Adesmus facetus sp. nov. e Canarana arguta sp. nov. (Rondônia). É acrescentado novo registro na Costa Rica para Piruanycha pitilla Galileo & Martins, 2005. As três espécies novas de Adesmus distinguem-se: A. nigrolineatus sp. nov. pelas faixas longitudinais de tegumento preto nos élitros; A. moruna sp. nov. pelos élitros inteiramente pretos; A. facetus pelas faixas oblíquas de pubescência branca após o meio dos élitros além das manchas do quarto apical e das epipleuras. Phoebemima albomaculata sp. nov. caracteriza-se pela mancha basal de pubescência branca dos élitros estendendo-se sobre a sutura. Corcovado bezarki sp. nov. distingue-se pelo escapo preto e antenômeros esbranquiçados. Canarana arguta sp. nov. tem o protórax e os urosternitos I a IV cobertos por densa pubescência amarelada. Alampyris fusca sp. nov. difere de A. cretaria principalmente pelo antenômero III mais longo que o escapo. Cariua sulphurea sp. nov. separa-se pela presença de urosternitos revestidos por pubescência branca compacta e Ipepo dilatatus sp. nov. caracteriza-se pelos élitros tri-carenados.

Sistematização da origem, da distribuição e dos territórios da artéria cerebral caudal na superfície do encéfalo em gatos

Foram estudados 26 encéfalos de gatos, adultos, sem diferenciação de sexo, sem raça definida, corados com látex e fixados por solução aquosa de formaldeído. As artérias cerebrais caudais, direita e esquerda, apresentaram-se únicas em 96,1 e 88,4% dos casos, respectivamente. Em 69,2% dos casos no antímero direito e 80,8% no esquerdo, a artéria cerebral caudal originou-se pela anastomose entre o ramo caudal da artéria carótida interna, com maior contribuição, e o ramo terminal da artéria basilar. Em 88,4% dos casos no antímero direito e em 84,6% no esquerdo, a artéria cerebral caudal originou a artéria tectal rostral e um ramo caudal. O ramo caudal bifurcou-se e vascularizou os colículos rostrais e caudais dos corpos quadrigêmeos e em alguns casos contribuiu na formação do plexo coroide do terceiro ventrículo. A artéria tectal rostral seguiu ventralmente ao lobo piriforme e durante seu trajeto liberou ramos para o hipocampo e, no antímero esquerdo, supriu a superfície dorsal do tálamo, contribuindo para a formação do plexo coroide do terceiro ventrículo.

Diffractive phase-shift lithography photomask operating in proximity printing mode

A phase shift proximity printing lithographic mask is designed, manufactured and tested. Its design is based on a Fresnel computer-generated hologram, employing the scalar diffraction theory. The obtained amplitude and phase distributions were mapped into discrete levels. In addition, a coding scheme using sub-cells structure was employed in order to increase the number of discrete levels, thus increasing the degree of freedom in the resulting mask. The mask is fabricated on a fused silica substrate and an amorphous hydrogenated carbon (a:C-H) thin film which act as amplitude modulation agent. The lithographic image is projected onto a resist coated silicon wafer, placed at a distance of 50 mu m behind the mask. The results show a improvement of the achieved resolution - linewidth as good as 1.5 mu m - what is impossible to obtain with traditional binary masks in proximity printing mode. Such achieved dimensions can be used in the fabrication of MEMS and MOEMS devices. These results are obtained with a UV laser but also with a small arc lamp light source exploring the partial coherence of this source. (C) 2010 Optical Society of America

Os conhecimentos tradicional e científico do Saco do Arraial, estuário da Lagoa do Patos (RS)

Ethno-sciences study the logical behind the traditional population knowledge about environmental process. This case study aims at describing the ethno-knowledge of artisanal fishermen on the hydrodynamics of the estuary around Coreia community (Saco do Arraial), located in Dos Patos Lagoon, in southern Brazil, from an ethnooceangraphic perspective. For this purpose, mental maps, open-ended and in-depth semi-structured interviewing and participative research have been used. As well as scientific knowledge, rains and winds were had main hydrodynamic effort of Saco do Arraial, although astronomic influence in located hydrodynamic has been just a perception of traditional knowledge. Soon, these data have shown another important way to perceive the Patos Lagoon.