Chiral Spin-Orbital Liquids with Nodal Lines.

Strongly correlated materials with strong spin-orbit coupling hold promise for realizing topological phases with fractionalized excitations. Here, we propose a chiral spin-orbital liquid as a stable phase of a realistic model for heavy-element double perovskites. This spin liquid state has Majorana fermion excitations with a gapless spectrum characterized by nodal lines along the edges of the Brillouin zone. We show that the nodal lines are topological defects of a non-Abelian Berry connection and that the system exhibits dispersing surface states. We discuss some experimental signatures of this state and compare them with properties of the spin liquid candidate Ba_{2}YMoO_{6}.

Toxicidade aguda ao sal comum e larvicultura intensiva do jundiá Rhamdia quelen em água salobra / Acute toxicity of common salt and intensive larviculture of silver catfish Rhamdia quelen in brackish water

A tolerância de peixes de água doce à salinidade e os níveis adequados de náuplios de Artemia na alimentação durante a larvicultura são de extrema importância para a padronização dos manejos em ambientes de criação intensiva. Dessa forma, o objetivo do trabalho foi estimar a salinidade letal (SL50) para larvas de jundiá Rhamdia quelen e determinar o efeito da salinidade e da concentração de presas vivas na larvicultura intensiva. No primeiro ensaio, larvas ao final do período lecitotrófico (1,1±0,8mg) foram submetidas às salinidades de 0, 2, 4, 6, 8, 10, 15 e 20g de sal/L por um período de 96h. No segundo experimento, as larvas de jundiá, no início da alimentação exógena (1,2±0,3mg), foram submetidas a três salinidades (água doce 0, 2 e 4g de sal/L) e três concentrações de presas vivas (início: 300, 500, 700 náuplios de Artemia/larvas/dia, sendo esse montante aumentado a cada cinco dias). O experimento foi realizado em delineamento inteiramente ao acaso, em esquema fatorial 3x3, por um período de 15 dias. No experimento 1, as larvas de jundiá submetidas às salinidades de 10, 15 e 20g de sal/L morreram após 12, duas e uma hora de exposição, respectivamente. As SL50 de 72 e 96h foram estimadas em 9,93 e 4,95g de sal/L, respectivamente. No final do teste de toxicidade, não houve diferença na sobrevivência entre as salinidades de 0, 2 e 4g de sal/L. No experimento 2, não foi observado efeito da interação entre salinidade e concentração de presas para o peso e o comprimento. Quanto maior a quantidade de presas, maior o crescimento das larvas. A sobrevivência apresentou interação entre os fatores. O aumento da salinidade proporcionou uma diminuição da sobrevivência, independentemente da concentração de presas. Dessa forma, conclui-se que a SL50 diminuiu com o aumento do tempo de exposição à água salinizada e que a larvicultura da espécie pode ser realizada em salinidades de até 2g de sal/L, com concentração de presas vivas diária inicial de 700 náuplios de Artemia/larva.(AU)

The tolerance of freshwater fish to salinity and the adequate levels of Artemia nauplii in the feeding regime during larviculture are of extreme importance to the standardization of management practices in intensive production environments. Therefore, the aim of this study was to estimate the lethal salinity (LS50) of the silver catfish Rhamdia quelen larvae and determine the effect of salinity and the concentrations of live prey in intensive larviculture of this species. In the first trial, larvae at the end of the lecithotrophic period (1.1±0.8mg) were subjected to salinities of 0, 2, 4, 6, 8, 10, 15 and 20g of salt/L for a period of 96h. In the second experiment, the catfish larvae starting the exogenous feed (1.2±0.3mg) were subjected to three salinities (freshwater 0, 2 and 4g of salt/L) and three concentrations of live prey (starting at: 300, 500, 700 Artemia nauplii/larvae/day, this amount being increased every five days). The experiment was conducted in a completely randomized design in a 3x3 factorial scheme, for a period of 15 days. In experiment 1, the catfish larvae subjected to the salinities of 10, 15 and 20g of salt/L died after 12, 2 and 1h of exposure, respectively. The LS50 at 72 and 96 h were estimated at 9.93 and 4.95g of salt/L, respectively. At the end of the toxicity test, there was no difference in the survival among the salinities of 0, 2 and 4g of salt/L. In experiment 2 no significant interaction was observed between salinity and the concentration of prey for weight and length. The increased quantity of prey increased the growth of the larvae. The rise in the salinity correlated to a decrease in survival, regardless of the prey concentration. Thus, it is concluded that the LS50 decreased with the increase in time of exposure to saltwater, and that the larviculture of this specie can be conducted in salinities of up to 2g salt/L, with a daily prey concentration starting at 700 Artemia/larvae.(AU)

Tkachenko polarons in vortex lattices.

We analyze the properties of impurities immersed in a vortex lattice formed by ultracold bosons in the mean field quantum Hall regime. In addition to the effects of a periodic lattice potential, the impurity is dressed by collective modes with parabolic dispersion (Tkachenko modes). We derive the effective polaron model, which contains a marginal impurity-phonon interaction. The polaron spectral function exhibits a Lorentzian broadening for arbitrarily small wave vectors even at zero temperature, in contrast with the result for optical or acoustic phonons. The anomalous damping of Tkachenko polarons could be detected experimentally using momentum-resolved spectroscopy.

Comercialização de plantas medicinais no contexto da cadeia produtiva em Minas Gerais / Commercialization of medicinal plants in the context of the productive chain in Minas Gerais

A Política Nacional de Práticas Integrativas e Complementares no Sistema Único de Saúde (SUS) contribuiu para o incremento do uso e conhecimento das plantas medicinais brasileiras, incentivando e respaldando o cultivo por agricultores familiares e a inserção no mercado. O Programa de Desenvolvimento de Plantas Medicinais prioriza ações em toda a cadeia produtiva do cultivo à distribuição. O conhecimento da demanda e dos padrões de qualidade adequados permite que distribuidores e consumidores possam tomar decisões sobre a aquisição e oferta dos produtos medicinais. Entretanto, há carência de informações e tecnologias na cadeia produtiva, o que desfavorece o seu pleno desenvolvimento, condizente com o potencial de geração de renda e promoção da saúde. O objetivo deste trabalho foi identificar e analisar o padrão atual de obtenção e comercialização de plantas medicinais no Mercado Central de Belo Horizonte. Foram realizadas entrevistas semi-estruturadas com amostra representativa de 9 comerciantes das 23 lojas de plantas medicinais do Mercado Central, de acordo com o critério de acessibilidade descrito por Berquó. Os resultados demonstraram a precariedade desse setor quanto à obtenção das plantas medicinais, principalmente pela falta de conhecimento e informações na aquisição e venda dos produtos pelos consumidores e vendedores, respectivamente.

The National Politic Integrative and complementary Practices in Health System (SUS) contributed to the increased use and knowledge of Brazilian medicinal plants, which encourages and supports the growing of family farmers and their integration in efficient markets. The Program for the Development of Medicinal Plants prioritizes actions in the entire production chain from cultivation to distribution. Knowledge of demand and adequate quality standards allows distributors and consumers to make decisions on the acquisition and supply of medicinal products. However, there is a lack of information and technologies in this supply chain, which discourages its full development, consistent with the potential for income generation and health promotion presents. The objective of this study was to identify and analyze current patterns of production and marketing of medicinal plants in the Central Market of Belo Horizonte. We conducted semi-structured interviews with nine of the 23 stores trades of medicinal plants from the Central Market. Results showed the precarious nature of this sector in obtaining medicinal plants, mainly by lack of knowledge and information in the purchase and sale of products by consumers and sellers, respectively.

Low temperature conversion (LTC)--an alternative method to treat sludge generated in an industrial wastewater treatment station--batch and continuous process comparison.

In this work low temperature conversion (LTC) process was applied in a dried sludge from a petrochemical industry wastewater treatment station located in Rio de Janeiro, Brazil. The process was performed in two modes: continuous and batch-scale. This process produced a pyrolysis oil (continuous 14%; batch-scale 40% yield); pyrolytic char (continuous 46%; batch-scale 56% yield); gas and water. Pyrolysis oil fraction was analyzed by gas chromatographic mass spectrometry (GCMS) and the main components identified were toluene, ethylbenzene, styrene, isopropyl benzene, alpha-methylstyrene, butanenitrile and 1,3- biphenyl propane. Metals content, sulfur content and calorific value have been determined for the pyrolysis oil fraction. The results showed that the pyrolysis oil obtained could be used for industrial purposes and/or as energetic matrix.

Diffusion and ballistic transport in one-dimensional quantum systems.

It has been conjectured that transport in integrable one-dimensional systems is necessarily ballistic. The large diffusive response seen experimentally in nearly ideal realizations of the S=1/2 1D Heisenberg model is therefore puzzling and has not been explained so far. Here, we show that, contrary to common belief, diffusion is universally present in interacting 1D systems subject to a periodic lattice potential. We present a parameter-free formula for the spin-lattice relaxation rate which is in excellent agreement with experiment. Furthermore, we calculate the current decay directly in the thermodynamic limit using a time-dependent density matrix renormalization group algorithm and show that an anomalously large time scale exists even at high temperatures.

Dynamical spin structure factor for the anisotropic spin-1/2 Heisenberg chain.

The longitudinal spin structure factor for the XXZ-chain at small wave vector q is obtained using Bethe ansatz, field theory methods, and the density matrix renormalization group. It consists of a peak with a peculiar, non-Lorentzian shape and a high-frequency tail. We show that the width of the peak is proportional to q2 for finite magnetic field compared to q3 for a zero field. For the tail we derive an analytic formula without any adjustable parameters and demonstrate that the integrability of the model directly affects the line shape.

Bioaerossóis bacterianos em um hospital / Bacterial bioaerosols in hospital

A contaminação microbiológica de ambientes internos é afetada pela presença de bioaerossóis do ambiente externo e as geradas no próprio ambiente. O objetivo deste trabalho é relacionar a concentração de bioaerossóis encontrados em ambientes internos de um hospital em relação ao ar exterior, levando em consideração alguns parâmetros ambientais que influenciam na qualidade do ar, como número de ocupantes e tipo de ventilação. Quinhentos litros de ar foram coletados, por impacto, durante cinco minutos, utilizando-se um amostrador de ar de um estágio sobre placas de meios de cultura. A concentração média de bioaerossóis bacterianos viáveis no ambiente externo de um hospital do interior do Estado de São Paulo foi de 77 ± 4 UFC/m3 e no ambiente interior de 302 ± 260 UFC/m3 de ar. O centro cirúrgico, após cirurgia ortopédica, único ambiente climatizado amostrado, apresentou a maior concentração (867 ± 482 UFC/m3). Nos ambientes interiores nove espécies bacterianas foram identificadas. Apesar da dificuldade em se estabelecer valores para a concentração de bioaerossóis bacterianos em ambientes hospitalares, os resultados demonstram a necessidade de programas apropriados para a manutenção da concentração microbiana baixa nesses ambientes e ausência de microrganismos que possam significar risco para os seus ocupantes. O monitoramento do ar deveria ser recomendado objetivando definir quantidades aceitáveis de contaminantes bacterianos

Rinoseptoplastia aberta para tratamento de deformidade nasal na fissura unilateral / Open rhinoseptoplasty for the treatment of nasal deformity in the unilateral cleft lip

A correção das deformidades nasais associadas à fissura unilateral tem-se demonstrado de difícil solução cirúrgica. As características do nariz fissurado são bem conhecidas com mais de vinte alterações anatômicas. Nos últimos vinte anos, muitas técnicas e táticas foram desenvolvidas para corrigir a deformidade nasal associada à fissura unilateral. Apresentamos nossa experiência na correção da deformidade nasal em fissurados labiais unilaterais com rinoseptoplastia aberta tardia em 69 pacientes e os resultados estético e funcional.

The correction of nasal deformities in unilateral cleft lip has been demonstrated of hard surgery solution. The characteristics features of cleft lip nose are wellknown with more than 20 abnormal anatomical components. Within the last twenty years, many techniques had been developed to correct the associated nasal deformity associated with unilateral cleft lip. We present our experience in the correction of unilateral cleft lip nasal deformity with delayed open rhinoseptoplasty in 69 patients and the cosmetic and functional results.

Dimerization induced by the RKKY interaction.

We report the presence of spin dimerization in the ground state of the one-dimensional Kondo lattice model at quarter filling. The emergence of this new phase of the Kondo lattice can be traced to the form of the RKKY interaction between the localized moments and provides the first example of dimerization induced indirectly by itinerant electrons. We propose this dimer ordering as the driving mechanism of the spin-Peierls phase observed in the quasi-one-dimensional organic compounds (Per)2M(mnt)(2) (M=Pt, Pd). Moreover, this suggests that a richer phase diagram than the Doniach paradigm may be needed to accommodate the physics of heavy fermion materials.

Prevalence of human immunodeficiency virus infection in alcoholics.

To verify the prevalence of infection by human immunodeficiency virus (HIV) in alcoholics we studied 131 alcoholic patients (119 males and 12 females) with a mean age of 44.3 +/- 10.8 years. Serum samples were collected from this group and analysed, by ELISA, for antibodies against HIV as well as for serological markers for hepatitis B virus (HBV) and hepatitis C virus (HCV). As we have previously described, we found a high prevalence of HBV (26.4%) and HCV (4.2%) markers as compared to the prevalence of these markers in samples of normal blood donors from Uberlândia's Hemocentro Regional, which are 4% and 0.4%, respectively. Of the 131 patients, four (3%) had antibodies against HIV, three (75%) of which were injecting drug users (IDU). In the HIV-negative group, only one patient was an IDU. The prevalence of HIV in our population, according to data from the city's Health Secretary, varies from 3.1% to 6.2%. We conclude that, at least for the moment, alcoholism per se, did not constitute an important risk factor for HIV infection. However, acquired immunodeficiency syndrome is a rather recent disease as compared to hepatitis B and C and, as the transmission routes are similar for HIV and hepatitis viruses, an increase in the incidence of HIV infection in alcoholics may be just a question of time.