831 research outputs found

    O Cuidado Como Elemento De Sustentabilidade Em Situações De Crise. Portugal Entre O Estado Providência E As Relações Interpessoais

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    Portugal is going through a socio-economic crisis which has led to increased pressure on social services. Faced with the reduced capacity of state care systems to continue providing support, people are (re)turning to informal ways of addressing the problem. During field work among middleclass families from Lisbon and Oporto, we witnessed how people simultaneously engage with both formal and informal care systems. The article discusses the ways in which informal practices are used to respond to crisis situations, thus contributing to social sustainability. © 2016, Universidade Estadual de Campinas UNICAMP. All Right reserved.2016467910

    The one-dimensional XXZ model with long-range interactions

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    The one-dimensional XXZ model (s=1/2, N sites) with uniform long-range interactions among the transverse components of the spins is considered. The Hamiltonian of the model is explicitly given by H=Jj=1N(sjxsj+1x+sjysj+1y)(I/N)j,k=1Nsjzskzhj=1Nsjz,H=J\sum_{j=1}^{N}(s_{j}^{x}s_{j+1}^{x}+s_{j}^{y}s_{j+1}^{y}) -(I/N)\sum_{j,k=1}^{N}s_{j}^{z}s_{k}^{z}-h\sum_{j=1}^{N}s_{j}^{z}, where the sx,y,zs^{x,y,z} are half the Pauli spin matrices. The model is exactly solved by applying the Jordan-Wigner fermionization, followed by a Gaussian transformation. In the absence of the long-range interactions (I=0), the model, which reduces to the isotropic XY model, is known to exhibit a second-order quantum phase transition driven by the field at zero temperature. It is shown that in the presence of the long-range interactions (I different from 0) the nature of the transition is strongly affected. For I>0, which favours the ordering of the transverse components of the spins, the transition is changed from second- to first-order, due to the competition between transverse and xy couplings. On the other hand, for I<0, which induces complete frustration of the spins, a second-order transition is still present, although the system is driven out of its usual universality class, and its critical exponents assume typical mean-field values.Comment: 5 pages, 1 figure, presented at ICM2000, to be published in the Proceedings (Journal of Magnetism & Magnetic Materials

    Sistema tradicional de manejo de caprinos II. Desempenho de caprinos SRD na fase de pós-aleitamento

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    The pattern of growth of SRD kids from an average of 153 days up to approximately 461 days of age was studied. Weights at the ages of 153 (W5), 181 (W6), 209 (W7), 237 (W8), 265 (W9), 293 (W10), 321 (W11), 349 (W12), 461 (W16) days and calculated weight gains (G) between every weight interval G5 = (W5 - Weaning weight) through G12 = (W12 - W 11) were evaluated. Data were initially recorded on 54 kids and diminished thereafter at every interval due to kid mortality. The least squares analysis of variance showed a significant season of birth effect (P 0.05) with the exception of type of birth for G12 (P 0,05), com exceção do tipo de nascimento para G12 (P < 0,025). As covariâncias de peso da mãe ao parto e idade do cabrito no momento da pesagem, foram significativas em algumas idades. Já para peso ao nascer, a covariável foi significativa para P7, P8, P10 (P < 0,005); P9 (P < 0,001); P6, P11 e G12 (P < 0,025).

    mu-Theraphotoxin-An1a: primary structure determination and assessment of the pharmacological activity of a promiscuous anti-insect toxin from the venom of the tarantula Acanthoscurria natalensis (Mygalomorphae, Theraphosidae)

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    Tarantulas are included in the mygalomorph spider family Theraphosidae. Although the pharmacological diversity of theraphosid toxins (theraphotoxins) is broad, studies dedicated to the characterization of biologically active molecules from the theraphosid genus Acanthoscurria have been restricted to the investigation of antimicrobial peptides and polyamines produced by the hemocytes of Acanthoscurria gomesiana. The present study reports the purification, primary structure determination and electrophysiological effects of an anti-insect toxin, named mu-theraphotoxin-An1a (mu-TRTX-An1a), from the venom of Acanthoscurria natalensis - a tarantula species occurring in the Brazilian biomes caatinga and cerrado. The analysis of the primary structure of mu-TRTX-An1a revealed the similarity of this toxin to theraphosid toxins bearing a huwentoxin-II-like fold. Electrophysiological experiments showed that mu-TRTX-An1a (100 nM) induces membrane depolarization, increases the spontaneous firing frequency and reduces spike amplitude of cockroach dorsal unpaired median (DUM) neurons. In addition, under voltage-clamp conditions, mu-TRTX-An1a (100 nM) only partially blocks voltage-dependent sodium current amplitudes in DUM neurons without any effect on their voltage dependence. This effect correlates well with the reduction of the spontaneous action potential amplitudes. Altogether, these last results suggest that mu-TRTX-An1a affects insect neuronal voltage-dependent sodium channels, which are among possible channels targeted by this promiscuous toxin

    Acetonitrile as adjuvant to tune polyethylene glycol + K3PO4 aqueous two-phase systems and its effect on phenolic compounds partition

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    Aqueous two-phase systems (ATPS) have been proposed as platforms for the purification of biomolecules, and the application of adjuvants to tune the properties of ATPS phases and their ability to extract and separate biological products investigated. This work addresses, for the first time, the use of acetonitrile (ACN) as adjuvant in ATPS composed of polyethylene glycol (PEG) of different molecular weights (from 400 to 20,000 g·mol−1) and potassium phosphate. The effect of ACN concentration (at 0.25, 2.5, 5 and 7.5 wt%) in the liquid-liquid equilibrium is here studied by measuring the phase diagrams, the composition of the phases in equilibrium and their Kamlet-Taft parameters. The results obtained demonstrate that the ACN presence increases the biphasic region of PEG-K3PO4 ATPS and its distribution between the coexisting phases is dependent on its concentration and ATPS composition. The difference in the dipolarity/polarizability of the coexisting phases is significantly affected by the presence of ACN in the ternary mixture. The partition of two phenolic compounds – protocatechuic acid and gallic acid – was studied, showing that ACN improves the partition of these molecules to the salt-rich phase, and that the system selectivity can be significantly improved by changing the concentration of the phase forming compounds.publishe

    The Advertisement Calls and Distribution of Two Sympatric Species of \u3cem\u3eChiasmocleis\u3c/em\u3e (Méhely 1904) (Anura, Microhylidae, Gastrophryninae) from the Atlantic Forest

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    The advertisement calls of Chiasmocleis cordeiroi and C. crucis are described for populations from the municipalities of Igrapiúna and Camacan, respectively, state of Bahia, Brazil. Both calls consist of multipulsed notes produced in series. Differences between the two calls are: dominant frequency, higher in C. cordeiroi (range 4500-4898 Hz; C. crucis range 4069-4435 Hz); note rate, higher in C. cordeiroi (range 6.20--7.46 s/note; C. crucis range 5.17-5.59 s/note); pulse rate, higher in C. cordeiroi (151.82-194.83 s/note; C. crucis range 125.30- 142.12 s/note); and the structure of the modulation patterns of the notes. Moreover, the advertisement calls of C. crucis and C. cordeiroi are more similar than the calls of all syntopic congeners. Furthermore, the current distribution of both species was extended

    Protocol for collection and separation of bone marrow mononuclear cells in Chlorocebus aethiops

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    Abstract: Chlorocebus aethiops is a species of non-human primate frequently used in biomedical research. Some research involves this species as an experimental model for various diseases and possible treatment with stem cells. The bone marrow is one of the main sources of these cells and provides easy access. The aim of this study was to standardize the protocol of collection and separation of bone marrow in C. aethiops. Ten animals were submitted to puncture of bone marrow with access to the iliac crest and cell separation by density gradient. The bone marrow of C. aethiops had an average of 97% viability. From the results achieved, we can conclude that C. aethiops is an excellent model to obtain and isolate mononuclear cells from bone marrow, fostering several studies in the field of cell therapy
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