Homologies of the flower and inflorescence in the early-divergent grass anomochloa (poaceae)

Premise of the study: The grass subfamily Anomochlooideae is phylogenetically significant as the sister group to all other grasses. Thus, comparison of their structure with that of other grasses could provide clues to the evolutionary origin of these characters. Methods: We describe the structure, embryology, and development of the flower and partial inflorescence of the monotypic Brazilian grass Anomochloa marantoidea. We compare these features with those of other early-divergent grasses such as Pharus and Streptochaeta and closely related Poales such as Ecdeiocolea. Key results: Anomochloa possesses several features that are characteristic of Poaceae, notably a scutellum, a solid style, reduced stamen number, and an ovary with a single ovule that develops into a single indehiscent fruit. Interpretation of floral patterning in Anomochloa is problematic because the ramification pattern of the florets places the bracts and axes in unusual positions relative to the primary inflorescence axis. Our study indicates that there is a single abaxial carpel in Anomochloa, probably due to a cryptic type of pseudomonomery in Anomochloa that resembles the pseudomonomery of other grasses. On the other hand, the Anomochloa flower differs from the typical grass flower in lacking lodicules and possessing four stamens, in contrast with the tristaminate condition that characterizes many other grasses. Conclusions: Using the median part of the innermost bract as a locator, we tentatively homologize the inner bract of the Anomochloa partial inflorescence with the palea of other grasses. In this interpretation, the pattern of monosymmetry due to stamen suppression differs from that of Ecdeiocolea. © 2012 Botanical Society of America.

Life mode of in situ Conularia in a Middle Devonian epibole

Exceptionally abundant specimens of Conularia aff. desiderata Hall occur in multiple marine obrution deposits, in a single sixth-order parasequence composed of argillaceous and silty very fine sandstone, in the Otsego Member of the Mount Marion Formation (Middle Devonian, Givetian) in eastern New York State, USA. Associated fossils consist mostly of rhynchonelliform brachiopods but also include bivalve molluscs, orthoconic nautiloids, linguliform brachiopods and gastropods. Many of the brachiopods, bivalve molluscs and conulariids have been buried in situ. Conulariids buried in situ are oriented with their aperture facing obliquely upward and with their long axis inclined at up to 87degree to bedding. Most specimens are solitary, but some occur in V-like pairs or in radial clusters consisting of three specimens, with the component specimens being about equally long or (less frequently) substantially different in length. The compacted apical end of Conularia buried in situ generally rests upon argillaceous sandstone. With one possible exception, none of the examined specimens terminates in a schott (apical wall), and internal schotts appear to be absent. The apical ends of specimens in V-like pairs and radial clusters show no direct evidence of interconnection of their periderms. The apical, middle or apertural region of some inclined specimens abuts or is in close lateral proximity to a recumbent conulariid or to one or more spiriferid brachiopods, some of which have been buried in their original life orientation. The azimuthal bearings of Conularia and nautiloid long axes and the directions in which conulariids open are nonrandom, with conulariids being preferentially aligned between 350 and 50degree and with their apertural end facing north-east, and nautiloids being preferentially aligned between 30 and 70degree. Otsego Member Conularia were erect or semi-erect, epifaunal or partially infaunal animals, the apical end of which rested upon very fine bottom sediment. The origin of V-like pairs and radial clusters remains enigmatic, but it is probable that production of schotts was not a regular feature of this animal's life history. Finally, conulariids and associated fauna were occasionally smothered by distal storm deposits, under the influence of relatively weak bottom currents. © The Palaeontological Association.

Effects of dentin dry/moist condition on the immediate adhesive performance of different solvent-based etch-and-rinse adhesivesystems

Purpose: The purpose of this research was to analyze and measure, under optical microscopy, the hybrid layer thickness and resin tags length, as well as the microtensile bond strength of two conventional adhesive systems when applied to dry and moist dentinal substrate. Methods: Thirty-two extracted human molars were randomly distributed into four groups according to the adhesive systems (XP Bond and Prime&Bond 2.1) and moisture condition (dry and moist). In Groups I and II, XP adhesive system was applied on dry and moist dentin, respectively; while Groups III and IV received PB adhesive system, in the same way as was done in Groups I and II, respectively. After adhesive and restorative procedures, all specimens were sectioned along their long axes; one hemi-tooth sample was subjected to the microtensile bond strength test while the other was decalcified and serially sectioned into six micron thick slices and sequentially mounted on glass slides. These sections were stained by the Brown and Brenn method for posterior analysis and measurement of the hybrid layer and resin tags under a light microscope with a micrometric ocular 40/075. Results: Data were analyzed using two-way ANOVA and Tukey's test (α=0.05). For the variable hybrid layer thickness, XP showed no significant differences between dry and moist dentin (5.2 μm and 5.5 μm, respectively), but for PB, hybrid layer was significantly thicker for moist (4.0 μm) than for dry dentin (3.0 μm). For the variable resin tags length XP showed 17.9 μm length for dry dentin and 20.8 μm for moist dentin; PB 11.7 μm for dry and 12.69 μm for moist dentin;there was no significant differences between them, independent of the moisture condition. For the variable microtensile bond strength, XP showed 38.0 MPa for dry dentin and 44.5 MPa for moist dentin; and PB showed 22.7 MPa for dry dentin and 20.8 MPa for dry dentin no significant difference was observed between moist and dry dentin for XP (p=0.2) and PB (p=0.7), but XP was presented significantly higher bond strength values than PB in both moisture conditions (p=0.003 for dry and p=0.002 for moist). Conclusion: The two-step butanol-based etch-and-rinse adhesive XP Bond presented a superior behavior with regard to the hybrid layer thickness, length of resin tags and bond strength to dry and moist dentin substrates when compared with two-step acetone-based adhesive system Prime&Bond2.1. © 2013 Elsevier Ltd.

The dimensionality of ecological networks

How many dimensions (trait-axes) are required to predict whether two species interact? This unanswered question originated with the idea of ecological niches, and yet bears relevance today for understanding what determines network structure. Here, we analyse a set of 200 ecological networks, including food webs, antagonistic and mutualistic networks, and find that the number of dimensions needed to completely explain all interactions is small (< 10), with model selection favouring less than five. Using 18 high-quality webs including several species traits, we identify which traits contribute the most to explaining network structure. We show that accounting for a few traits dramatically improves our understanding of the structure of ecological networks. Matching traits for resources and consumers, for example, fruit size and bill gape, are the most successful combinations. These results link ecologically important species attributes to large-scale community structure. © 2013 Blackwell Publishing Ltd/CNRS.

Role of interstitial pinning in the dynamical phases of vortices in superconducting films

We analyze the vortex dynamics in superconducting thin films with a periodic array of pinning centers. In particular, we study the effect of anisotropy for a Kagomé pinning network when longitudinal and transverse transport currents are applied. By solving the equations of motion for the vortex array numerically at zero temperature, we find different phases for the vortex dynamics, depending on the pinning and driving force. An unusual sequence of peaks for driving force along and perpendicular to the main lattice axes is observed for the differential resistance, reflecting the anisotropy of the transport properties and the complex behavior of the vortex system. This behavior may be understood in terms of interstitial pinning vacancies, which create channels of vortices with different pinning strengths. © 2012 Springer Science+Business Media, LLC.

Design and development of a low-cost solar tracker

To become competitive, ultimately, photovoltaics should have its costs reduced and use photovoltaic systems of greater efficiency. The main steps in this direction are the use of new materials, the improvement in the manufacture of modules and the adoption of techniques of maximum power point tracking and of solar tracking. This article aims at presenting the project and development of an azimuth and elevation solar tracker, based on a new conception of the positioning sensor, composed of an array of four photoresistors. The two direct current motors that operate in the vertical and horizontal axes are controlled by a proportional-integral microcontroller. The conditions of the project were low cost, small energy consumption and versatility. The microcontroller can also incorporate a maximum power point tracking algorithm. The performance of solar tracker prototype in the initial phase of field tests can be considered appropriate. © Institution of Engineers Australia, 2013.

Produção de matéria seca da braquiária de acordo com os atributos químicos de um Latossolo em Selvíria, Mato Grosso do Sul

Rustic forages as the signal-grass are predominant in areas of Cerrado in extensive livestock systems that favor soil degradation. However, with time, not even these forages can have a good development in those areas. The objective of this study was to analyze the variability of plant and soil attributes; to define the linear and spatial correlations between signal-grass yield and the chemical attributes of the studied soil, and to evaluate, among the chemical attributes of the soil, which one that best explain the variability in this forage yield. The experiment was conducted in an area that had been under pasture for more than 30 years, belonging to UNESP - Ilha Solteira Campus, located in Selvíria - MS. A geostatistical grid was installed in an oxisol, for soil and plant data collection, with 121 sampling stations, consisted of eleven transections with 160 m width in the direction of the Cartesian axes. The dry mass yield of signal-grass was low, presenting high variation. The attributes MSr, N, PB, MO1, MO2, pHa1, pHa2, pHk1 and pHk2 did not vary at random. They presented data variability from low to high and followed clearly defined spatial patterns, ranging between 17.7-162.9 m. There was significant linear correlation at 1% between MSr and N leaf, and between MSr and PB. The cross semivariograms MSr=f(N) and MSr=f(PB) confirmed that the dry matter can be estimated from data of nitrogen leaf and crude protein content of this forage.

Henneguya nagelii n. sp. (Myxozoa: Myxobolidae) in Cyphocharax nagelii (Steindachner, 1881) (Teleostei: Characiformes: Curimatidae) from the Peixe's River, São Paulo State, Brazil

A new species of Myxosporea, Henneguya nagelii n. sp., is described parasitizing the gills of Cyphocharax nagelii collected from Peixe's River, São Paulo State, Brazil. Among the fish examined, 16.7 % had gills parasitized by myxosporeans. The plasmodia were white, round, or oval and measured 150-250 μm. The mature spores were fusiform and had smooth wall. The spores measurements were the following: total length, 34.5 ± 4.2 (26.4-39.9) μm; body length, 12.0 ± 0.5 (11.2-11.9) μm; body width, 4.9 ± 0.3 (4.4-5.5) μm; and caudal process length, 22.4 ± 4.0 (14.7-27.3) μm. The polar capsules were elongated and of unequal size, with lengths of 4.9 ± 0.4 (4.0-5.9) μm and 5.2 ± 0.4 (4.6-6.0) μm for the longest and shortest axes, respectively. Capsule width was 1.8 ± 0.2 (1.5-2.2) μm. Each capsule contained a polar filament with six to eight turns. There was no mucous envelope or iodinophilous vacuole. Morphometric differences between this parasite and other species of the genus Henneguya indicated that the parasite observed in C. nagelii is a new species. This is the first species of Myxosporea described in Peixe's River. © 2013 Springer-Verlag Berlin Heidelberg.

Letramento digital e letramento escolar: uma abordagem linguística da prática de escrita em blogs

Pós-graduação em Estudos Linguísticos - IBILCE

Influência da injunção da base na fototriangulação de imagens obtidas com uma unidade de mapeamento móvel

Pós-graduação em Ciências Cartográficas - FCT

O contexto educativo e cultural da pobreza no ensino público municipal em São Bernardo do Campo

Pós-graduação em Artes - IA

Sensor eletro-óptico de tensões elevadas e sua viabilidade para implementação de TP óptico

Pós-graduação em Engenharia Elétrica - FEIS

Estudo de bifurcações e aplicações em análise de sistemas de energia elétrica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uso de recursos e padrão de co-ocorrência com insetos predadores em comunidades sub-tropicais de girinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ovinos como modelo experimental: estudo do joelho e mensuração dos ângulos tibiais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)