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Commercial propagation of pequizeiro, which stands out among the main native fruits of the Cerrado region for its high economic potential, has been done by seeds, despite their erratic germination. The objective of this study was to evaluate the effect of seed size and presence of thorns on the endocarp on seedling emergence of pequizeiro in the field. Seeds were collected in a pequizeiro commercial area in Canarana-MT, Brazil. Due to availability, 2,353 thorny seeds (3 sizes) and 106 seeds without thorns (medium sized) were tested. Thorny seeds were classified as large - longer than 50 mm; medium - between 40 and 50 mm; small - less than 40 mm. Seedling emergence started after 50 days in all seed categories, extending up to 100 days in the large seeds and to about 1 year after sowing in the small and medium sized ones. Small seeds showed a lower rate and speed of emergence compared to the others. Large seeds showed higher emergence speed compared to the medium ones. The presence of thorns did not affect seedling emergence. These results indicate the advantages of pequizeiro seed classification for sowing purposes. [ABSTRACT FROM AUTHOR]

Copyright of Journal Health NPEPS is the property of Journal Health NPEPS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rhizobia are symbiotic nitrogen-fixing bacteria in root nodules of legumes. In Morocco, faba bean ( Vicia faba L.), which is the main legume crop cultivated in the country, is often grown in marginal soils of arid and semi-arid regions. This study examines the phenotypic diversity of rhizobia nodulating V. faba isolated from different regions in Morocco for tolerance to some abiotic stresses. A total of 106 rhizobia strains isolated from nodules were identified at the species level by analysing 16S rDNA. Additionally, for selected strains recA , otsA , kup and nodA fragments were sequenced. 102 isolates are likely to belong to Rhizobium leguminosarum or R. laguerreae and 4 isolates to Ensifer meliloti . All strains tolerating salt concentrations of 428 or 342 mM NaCl as well as 127 or 99 mM Na2SO4 were highly resistant to alkaline conditions (pH 10) and high temperature (44 °C). Three strains: RhOF4 and RhOF53 (both are salt-tolerant) and RhOF6 (salt-sensitive) were selected to compare the influence of different levels of salt stress induced by NaCl on growth and on trehalose and potassium accumulation. We find a direct correlation between the trehalose contents of the rhizobial strains and their osmotolerance. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of the present study was to evaluate the effect of the collecting location on the sterility, viability and dormancy of Melinis minutiflora seeds, an important weed of conservation units in the cerrado regions in Brazil. Seeds of two cultivars, Roxo and Cabelo-de-Negro, were collected in the following conservation units, located in the Federal District (Distrito Federal), Brazil: Parque Nacional de Brasília, Reserva Ecológica do IBGE and Estação Ecológica de Águas Emendadas. The percentage of full seeds (containing caryopsis), seed viability and seed dormancy were evaluated. The results showed that seed viability was adequately evaluated using a germination test at the alternating temperatures of 20-30°C, in potassium nitrate at 0.5% with light, and seed dormancy at 25°C, in water and darkness. The collecting location affected the percentage of full seeds, specially in the cultivar Roxo (17.5% to 36.1%). It also affected seed dormancy in both cultivars (20% to 80%) and seed viability in the cultivar Roxo (80% to 96%). These results help to explain the ecological behavior of Melinis minutiflora. [ABSTRACT FROM AUTHOR]

There is hardly a more important sensory modality for humans and other mammals than vision. The first and best-known part of the visual system is the retina, which is not a mere photoreceptor or static camera but a sophisticated feature preprocessor with continuous input and several parallel output channels. These interacting channels represent the visual scene. Never before has it been known in neuroscience how these channels build up a "visual language". Our mammalian retina model can generate the elements of this visual language. In the present paper the design steps of the implementation of the multilayer CNN retinal model is shown. It is rare that an analogic CNN algorithm has such a sophisticated series of different complex dynamics, meanwhile it is feasible on a recently fabricated complex cell CNN-UM chip. The mammalian retina model is decomposed into a full-custom mixed-signal chip that embeds digitally programmable analog parallel processing and distributed image memory on a common silicon substrate. The chip was designed and manufactured in a standard 0.5 μm CMOS technology and contains approximately 500,000 transistors. It consists of 1024 processing units arranged into a 32×32 grid. The functional features of the chip are in accordance with the second-order complex cell CNN-UM architecture: two CNN layers with programmable inter- and intra-layer connections between cells as well as programmable layer time constants. The uniqueness of this approach, among others, lies in the reprogrammability, i.e. the openness to any new discovery, even after a possible retinal implementation. [ABSTRACT FROM AUTHOR]

This paper describes a full-custom mixed-signal chip that embeds digitally programmable analog parallel processing and distributed image memory on a common silicon substrate. The chip was designed and fabricated in a standard 0.5 μm CMOS technology and contains approximately 500 000 transistors. It consists of 1024 processing units arranged into a 32×32 grid. Each processing element contains two coupled CNN cores, thus, constituting two parallel layers of 32×32 nodes. The functional features of the chip are in accordance with the 2nd Order Complex Cell CNN-UM architecture. It is composed of two CNN layers with programmable inter- and intra-layer connections between cells. Other features are: cellular, spatial-invariant array architecture; randomly selectable memory of instructions; random storage and retrieval of intermediate images. The chip is capable of completing algorithmic image processing tasks controlled by the user-selected stored instructions. The internal analog circuitry is designed to operate with 7-bits equivalent accuracy. The physical implementation of a CNN containing second order cells allows real-time experiments of complex dynamics and active wave phenomena. Such well-known phenomena from the reaction–diffusion equations are traveling waves, autowaves, and spiral-waves. All of these active waves are demonstrated on-chip. Moreover this chip was specifically designed to be suitable for the computation of biologically inspired retina models. These computational experiments have been carried out in a developmental environment designed for testing and programming the analogic (analog-and-logic) programmable array processors. [ABSTRACT FROM AUTHOR]

This study estimated genetic and phenotypic parameters, heritabilities, correlations, selection accuracy, and expected gain from selection for dry matter yield and nutritional traits in 178 half-sib ruzigrass families. Eight traits were evaluated, with nutritional quality measured via NIRS. Data analysis using mixed models and clustering revealed significant differences between progenies. Narrow-sense heritability ranged from 0.26 to 0.42, and selection accuracy ranged from 0.51 to 0.65. Genetic variation was lower for nutritional quality traits compared to dry matter yield. Dry matter yield had positive genetic correlations with neutral and acid detergent fiber and cellulose, but negative correlations with crude protein and hemicellulose. Clustering identified two groups of families: one correlated with in vitro dry matter digestibility and crude protein, and the other with remaining traits. Selecting for dry matter yield may reduce crude protein content but not affect digestibility; selecting for low fiber or high crude protein may improve forage quality. [ABSTRACT FROM AUTHOR]

This study aimed to test methodologies to evaluate the pollen viability of eggplant. The pollen germination was tested in vitro, incubating the pollen during 0.5 and 16 hours in different sucrose concentrations (0; 2.5; 5.0; 7.5 and 10.0 g L-1). For the in vivo germination test, the pollen was placed during 4 and 24 hours in the flower stigma and after that stained with aniline blue and evaluated in an ultraviolet light microscope. The viability of the pollen grains was also evaluated in tetrazolium solutions (at the concentrations of 1%; 0.75% and 0.5%) and the staining was evaluated after 24 hours. The highest in vitro pollen germination was 10.8%, showing the necessity for a better calibration of the culture medium. The in vivo pollen germination was 66%, showing that this is an adequate methodology to estimate pollen viability in eggplant. The methodologies involving tetrazolium solution weren't efficient to estimate pollen viability evaluation, because of the deficient pollen staining. [ABSTRACT FROM AUTHOR]