Wild bearded capuchin monkeys (Cebus libidinosus) place nuts in anvils selectively

Are wild bearded capuchin monkeys selective about where they place nuts on anvils, specifically the anvil pits, during nut cracking? In the present study, we examined (1) whether capuchins` preferences for particular pits are influenced by the effectiveness of the pit in cracking the nut and/or by the stability of the nut during striking, (2) how capuchins detect the affordances of novel pits and (3) the influence of social context on their selections. Anvil pits varied in horizontal dimension (small, medium and large) in experiment 1 and in depth (shallow, medium and deep) in experiment 2. In both experiments, three different pits were simultaneously presented, each on one anvil. We coded the capuchins` actions with the nut in each pit, and recorded the outcome of each strike. In both experiments, capuchins preferred the most effective pit, but not the most stabilizing pit, based on the number of first strikes, total strikes and nuts cracked. Their choice also reflected where the preceding individual had last struck. The capuchins explored the pits indirectly, placing nuts in them and striking nuts with a stone. The preference for pits was weaker than the preference for nuts and stones shown previously with the same monkeys. Our findings suggest that detecting affordances of pits through indirect action is less precise than through direct action, and that social context may also influence selection. We show that field experiments can demonstrate embodied cognition in species-typical activities in natural environments. (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Genetic characterization of fig tree mutants with molecular markers

The fig (Ficus carica L.) is a fruit tree of great world importance and, therefore, the genetic improvement becomes an important field of research for better crops, being necessary to gather information on this species, mainly regarding its genetic variability so that appropriate propagation projects and management are made. The improvement programs of fig trees using conventional procedures in order to obtain new cultivars are rare in many countries, such as Brazil, especially due to the little genetic variability and to the difficulties in obtaining plants from gamete fusion once the wasp Blastophaga psenes, responsible for the natural pollinating, is not found in Brazil. In this way, the mutagenic genetic improvement becomes a solution of it. For this reason, in an experiment conducted earlier, fig plants formed by cuttings treated with gamma ray were selected based on their agronomic characteristics of interest. We determined the genetic variability in these fig tree selections, using RAPD and AFLP molecular markers, comparing them to each other and to the Roxo-de-Valinhos, used as the standard. For the reactions of DNA amplification, 140 RAPD primers and 12 primer combinations for AFLP analysis were used. The selections did not differ genetically between themselves and between them and the Roxo-de-Valinhos cultivar. Techniques that can detect polymorphism between treatments, such as DNA sequencing, must be tested. The phenotypic variation of plants may be due to epigenetic variation, necessitating the use of techniques with methylation-sensitive restriction enzymes.

A direct D-bar reconstruction algorithm for recovering a complex conductivity in 2D

A direct reconstruction algorithm for complex conductivities in W-2,W-infinity(Omega), where Omega is a bounded, simply connected Lipschitz domain in R-2, is presented. The framework is based on the uniqueness proof by Francini (2000 Inverse Problems 6 107-19), but equations relating the Dirichlet-to-Neumann to the scattering transform and the exponentially growing solutions are not present in that work, and are derived here. The algorithm constitutes the first D-bar method for the reconstruction of conductivities and permittivities in two dimensions. Reconstructions of numerically simulated chest phantoms with discontinuities at the organ boundaries are included.

Optimal Code Set Selection and Security Issues in Spectral Phase-Encoded Time Spreading (SPECTS) OCDMA Systems

In this paper, we perform a thorough analysis of a spectral phase-encoded time spreading optical code division multiple access (SPECTS-OCDMA) system based on Walsh-Hadamard (W-H) codes aiming not only at finding optimal code-set selections but also at assessing its loss of security due to crosstalk. We prove that an inadequate choice of codes can make the crosstalk between active users to become large enough so as to cause the data from the user of interest to be detected by other user. The proposed algorithm for code optimization targets code sets that produce minimum bit error rate (BER) among all codes for a specific number of simultaneous users. This methodology allows us to find optimal code sets for any OCDMA system, regardless the code family used and the number of active users. This procedure is crucial for circumventing the unexpected lack of security due to crosstalk. We also show that a SPECTS-OCDMA system based on W-H 32(64) fundamentally limits the number of simultaneous users to 4(8) with no security violation due to crosstalk. More importantly, we prove that only a small fraction of the available code sets is actually immune to crosstalk with acceptable BER (<10(-9)) i.e., approximately 0.5% for W-H 32 with four simultaneous users, and about 1 x 10(-4)% for W-H 64 with eight simultaneous users.

An estimate on the fractal dimension of attractors of gradient-like dynamical systems

This paper is dedicated to estimate the fractal dimension of exponential global attractors of some generalized gradient-like semigroups in a general Banach space in terms of the maximum of the dimension of the local unstable manifolds of the isolated invariant sets, Lipschitz properties of the semigroup and the rate of exponential attraction. We also generalize this result for some special evolution processes, introducing a concept of Morse decomposition with pullback attractivity. Under suitable assumptions, if (A, A*) is an attractor-repeller pair for the attractor A of a semigroup {T(t) : t >= 0}, then the fractal dimension of A can be estimated in terms of the fractal dimension of the local unstable manifold of A*, the fractal dimension of A, the Lipschitz properties of the semigroup and the rate of the exponential attraction. The ingredients of the proof are the notion of generalized gradient-like semigroups and their regular attractors, Morse decomposition and a fine analysis of the structure of the attractors. As we said previously, we generalize this result for some evolution processes using the same basic ideas. (C) 2012 Elsevier Ltd. All rights reserved.

J/psi suppression at forward rapidity in Au plus Au collisions at root s(NN)=39 and 62.4 GeV

We present measurements of the J/psi invariant yields in root s(NN) = 39 and 62.4 GeV Au + Au collisions at forward rapidity (1.2 < vertical bar y vertical bar < 2.2). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au + Au collisions (R-CP) and for various centrality selections in Au + Au relative to scaled p + p cross sections obtained from other measurements (R-AA). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement. DOI: 10.1103/PhysRevC.86.064901

The capability of endophytic fungi for production of hemicellulases and related enzymes

Abstract Background There is an imperative necessity for alternative sources of energy able to reduce the world dependence of fossil oil. One of the most successful options is ethanol obtained mainly from sugarcane and corn fermentation. The foremost residue from sugarcane industry is the bagasse, a rich lignocellulosic raw material uses for the production of ethanol second generation (2G). New cellulolytic and hemicellulytic enzymes are needed, in order to optimize the degradation of bagasse and production of ethanol 2G. Results The ability to produce hemicellulases and related enzymes, suitable for lignocellulosic biomass deconstruction, was explored using 110 endophytic fungi and 9 fungi isolated from spoiled books in Brazil. Two initial selections were performed, one employing the esculin gel diffusion assay, and the other by culturing on agar plate media with beechwood xylan and liquor from the hydrothermal pretreatment of sugar cane bagasse. A total of 56 isolates were then grown at 29°C on steam-exploded delignified sugar cane bagasse (DEB) plus soybean bran (SB) (3:1), with measurement of the xylanase, pectinase, β-glucosidase, CMCase, and FPase activities. Twelve strains were selected, and their enzyme extracts were assessed using different substrates. Finally, the best six strains were grown under xylan and pectin, and several glycohydrolases activities were also assessed. These strains were identified morphologically and by sequencing the internal transcribed spacer (ITS) regions and the partial β-tubulin gene (BT2). The best six strains were identified as Aspergillus niger DR02, Trichoderma atroviride DR17 and DR19, Alternaria sp. DR45, Annulohypoxylon stigyum DR47 and Talaromyces wortmannii DR49. These strains produced glycohydrolases with different profiles, and production was highly influenced by the carbon sources in the media. Conclusions The selected endophytic fungi Aspergillus niger DR02, Trichoderma atroviride DR17 and DR19, Alternaria sp. DR45, Annulohypoxylon stigyum DR47 and Talaromyces wortmannii DR49 are excellent producers of hydrolytic enzymes to be used as part of blends to decompose sugarcane biomass at industrial level.

The capability of endophytic fungi for production of hemicellulases and related enzymes

Abstract BACKGROUND: There is an imperative necessity for alternative sources of energy able to reduce the world dependence of fossil oil. One of the most successful options is ethanol obtained mainly from sugarcane and corn fermentation. The foremost residue from sugarcane industry is the bagasse, a rich lignocellulosic raw material uses for the production of ethanol second generation (2G). New cellulolytic and hemicellulytic enzymes are needed, in order to optimize the degradation of bagasse and production of ethanol 2G. RESULTS: The ability to produce hemicellulases and related enzymes, suitable for lignocellulosic biomass deconstruction, was explored using 110 endophytic fungi and 9 fungi isolated from spoiled books in Brazil. Two initial selections were performed, one employing the esculin gel diffusion assay, and the other by culturing on agar plate media with beechwood xylan and liquor from the hydrothermal pretreatment of sugar cane bagasse. A total of 56 isolates were then grown at 29°C on steam-exploded delignified sugar cane bagasse (DEB) plus soybean bran (SB) (3:1), with measurement of the xylanase, pectinase, β-glucosidase, CMCase, and FPase activities. Twelve strains were selected, and their enzyme extracts were assessed using different substrates. Finally, the best six strains were grown under xylan and pectin, and several glycohydrolases activities were also assessed. These strains were identified morphologically and by sequencing the internal transcribed spacer (ITS) regions and the partial β-tubulin gene (BT2). The best six strains were identified as Aspergillus niger DR02, Trichoderma atroviride DR17 and DR19, Alternaria sp. DR45, Annulohypoxylon stigyum DR47 and Talaromyces wortmannii DR49. These strains produced glycohydrolases with different profiles, and production was highly influenced by the carbon sources in the media. CONCLUSIONS: The selected endophytic fungi Aspergillus niger DR02, Trichoderma atroviride DR17 and DR19, Alternaria sp. DR45, Annulohypoxylon stigyum DR47 and Talaromyces wortmannii DR49 are excellent producers of hydrolytic enzymes to be used as part of blends to decompose sugarcane biomass at industrial level.