Dynamical properties of S-gap shifts and other shift spaces

We study the dynamical properties of certain shift spaces. To help study these properties we introduce two new classes of shifts, namely boundedly supermultiplicative (BSM) shifts and balanced shifts. It turns out that any almost specified shift is both BSM and balanced, and any balanced shift is BSM. However, as we will demonstrate, there are examples of shifts which are BSM but not balanced. We also study the measure theoretic properties of balanced shifts. We show that a shift space admits a Gibbs state if and only if it is balanced. Restricting ourselves to S-gap shifts, we relate certain dynamical properties of an S-gap shift to combinatorial properties from expansions in non-integer bases. This identification allows us to use the machinery from expansions in non-integer bases to give straightforward constructions of S -gap shifts with certain desirable properties. We show that for any q∈(0,1) there is an S-gap shift which has the specification property and entropy q . We also use this identification to address the question, for a given q∈(0,1), how many S-gap shifts exist with entropy q? For certain exceptional values of q there is a unique S-gap shift with this entropy.

Trypanosome Prereplication Machinery Contains a Single Functional Orc1/Cdc6 Protein, Which Is Typical of Archaea

In unicellular eukaryotes, such as Saccharomyces cerevisiae, and in multicellular organisms, the replication origin is recognized by the heterohexamer origin recognition complex (ORC) containing six proteins, Orc1 to Orc6, while in members of the domain Archaea, the replication origin is recognized by just one protein, Orc1/Cdc6; the sequence of Orc1/Cdc6 is highly related to those of Orc1 and Cdc6. Similar to Archaea, trypanosomatid genomes contain only one gene encoding a protein named Orc1. Since trypanosome Orc1 is also homologous to Cdc6, in this study we named the Orc1 protein from trypanosomes Orc1/Cdc6. Here we show that the recombinant Orc1/Cdc6 from Trypanosoma cruzi (TcOrc1/Cdc6) and from Trypanosoma brucei (TbOrc1/Cdc6) present ATPase activity, typical of prereplication machinery components. Also, TcOrc1/Cdc6 and TbOrc1/Cdc6 replaced yeast Cdc6 but not Orc1 in a phenotypic complementation assay. The induction of Orc1/Cdc6 silencing by RNA interference in T. brucei resulted in enucleated cells, strongly suggesting the involvement of Orc1/Cdc6 in DNA replication. Orc1/Cdc6 is expressed during the entire cell cycle in the nuclei of trypanosomes, remaining associated with chromatin in all stages of the cell cycle. These results allowed us to conclude that Orc1/Cdc6 is indeed a member of the trypanosome prereplication machinery and point out that trypanosomes carry a prereplication machinery that is less complex than other eukaryotes and closer to archaea.

Endurance training activates AMP-activated protein kinase, increases expression of uncoupling protein 2 and reduces insulin secretion from rat pancreatic islets

Endurance exercise is known to enhance peripheral insulin sensitivity and reduce insulin secretion. However, it is unknown whether the latter effect is due to the reduction in plasma substrate availability or alterations in beta-cell secretory machinery. Here, we tested the hypothesis that endurance exercise reduces insulin secretion by altering the intracellular energy-sensitive AMP-activated kinase (AMPK) signaling pathway. Male Wistar rats were submitted to endurance protocol training one, three, or five times per week, over 8 weeks. After that, pancreatic islets were isolated, and glucose-induced insulin secretion (GIIS), glucose transporter 2 (GLUT2) protein content, total and phosphorylated calmodulin kinase kinase (CaMKII), and AMPK levels as well as peroxisome proliferator-activated receptor-gamma coactivator-1-alpha (PGC-1 alpha) and uncoupling protein 2 (UCP2) content were measured. After 8 weeks, chronic endurance exercise reduced GIIS in a dose-response manner proportionally to weekly exercise frequency. Contrariwise, increases in GLUT2 protein content, CaMKII and AMPK phosphorylation levels were observed. These alterations were accompanied by an increase in UCP2 content, probably mediated by an enhancement in PGC-1 alpha protein expression. In conclusion, chronic endurance exercise induces adaptations in beta-cells leading to a reduction in GIIS, probably by activating the AMPK signaling pathway. Journal of Endocrinology (2011) 208, 257-264

T3 rapidly modulates TSH beta mRNA stability and translational rate in the pituitary of hypothyroid rats

Whereas it is well known that T3 inhibits TSH beta gene transcription, its effects on TSH beta mRNA stability and translation have been poorly investigated. This study examined these possibilities, by evaluating the TSH beta transcripts poly(A) tail length, translational rate and binding to cytoskeleton, in pituitaries of thyroidectomized and sham-operated rats treated with T3 or saline, and killed 30 min thereafter. The hypothyroidism induced an increase of TSH beta transcript poly(A) tail, as well as of its content in ribosomes and attachment to cytoskeleton. The hypothyroid rats acutely treated with T3 exhibited a reduction of TSH beta mRNA poly(A) tail length and recruitment to ribosomes, indicating that this treatment decreased the stability and translation rate of TSH beta mRNA. Nevertheless, acute T3 administration to sham-operated rats provoked an increase of TSH beta transcripts binding to ribosomes. These data add new insight to an important role of T3 in rapidly regulating TSH gene expression at posttranscriptional level. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Watch-and-Comment as a Paradigm toward Ubiquitous Interactive Video Editing

The literature reports research efforts allowing the editing of interactive TV multimedia documents by end-users. In this article we propose complementary contributions relative to end-user generated interactive video, video tagging, and collaboration. In earlier work we proposed the watch-and-comment (WaC) paradigm as the seamless capture of an individual`s comments so that corresponding annotated interactive videos be automatically generated. As a proof of concept, we implemented a prototype application, the WACTOOL, that supports the capture of digital ink and voice comments over individual frames and segments of the video, producing a declarative document that specifies both: different media stream structure and synchronization. In this article, we extend the WaC paradigm in two ways. First, user-video interactions are associated with edit commands and digital ink operations. Second, focusing on collaboration and distribution issues, we employ annotations as simple containers for context information by using them as tags in order to organize, store and distribute information in a P2P-based multimedia capture platform. We highlight the design principles of the watch-and-comment paradigm, and demonstrate related results including the current version of the WACTOOL and its architecture. We also illustrate how an interactive video produced by the WACTOOL can be rendered in an interactive video environment, the Ginga-NCL player, and include results from a preliminary evaluation.

Control and chaos for vibro-impact and non-ideal oscillators

In the paper, we discuss dynamics of two kinds of mechanical systems. Initially, we consider vibro-impact systems which have many implementations in applied mechanics, ranging from drilling machinery and metal cutting processes to gear boxes. Moreover, from the point of view of dynamical systems, vibro-impact systems exhibit a rich variety of phenomena, particularly chaotic motion. In this paper, we review recent works on the dynamics of vibro-impact systems, focusing on chaotic motion and its control. The considered systems are a gear-rattling model and a smart damper to suppress chaotic motion. Furthermore, we investigate systems with non-ideal energy source, represented by a limited power supply. As an example of a non-ideal system, we analyse chaotic dynamics of the damped Duffing oscillator coupled to a rotor. Then, we show how to use a tuned liquid damper to control the attractors of this non-ideal oscillator.

PILZ Protein Structure and Interactions with PILB and the FIMX EAL Domain: Implications for Control of Type IV Pilus Biogenesis

The PilZ protein was originally identified as necessary for type IV pilus (T4P) biogenesis. Since then, a large and diverse family of bacterial PilZ homology domains have been identified, some of which have been implicated in signaling pathways that control important processes, including motility, virulence and biofilm formation. Furthermore, many PilZ homology domains, though not PilZ itself, have been shown to bind the important bacterial second messenger bis(3`-> 5`)cyclic diGMP (c-diGMP). The crystal structures of the PilZ orthologs from Xanthomonas axonopodis pv Citri (PilZ(XAC1133), this work) and from Xanthomonas campestris pv campestris (XC1028) present significant structural differences to other PilZ homologs that explain its failure to bind c-diGMP. NMR analysis of PilZ(XAC1133) shows that these structural differences are maintained in solution. In spite of their emerging importance in bacterial signaling, the means by which NZ proteins regulate specific processes is not clear. In this study, we show that PilZ(XAC1133) binds to PilB, an ATPase required for TV polymerization, and to the EAL domain of FiMX(XAC2398), which regulates TV biogenesis and localization in other bacterial species. These interactions were confirmed in NMR, two-hybrid and far-Western blot assays and are the first interactions observed between any PilZ domain and a target protein. While we were unable to detect phosphodiesterase activity for FimXX(AC2398) in vitro, we show that it binds c-diGMP both in the presence and in the absence of PilZ(XAC1133). Site-directed mutagenesis studies for conserved and exposed residues suggest that PilZ(XAC1133) interactions with FimX(XAC2398) and PilB(XAC3239) are mediated through a hydrophobic surface and an unstructured C-terminal extension conserved only in PilZ orthologs. The FimX-PilZ-PilB interactions involve a full set of ""degenerate"" GGDEF, EAL and PilZ domains and provide the first evidence of the means by which PilZ orthologs and FimX interact directly with the TP4 machinery. (C) 2009 Elsevier Ltd. All rights reserved.

Game Audio in Audio Games : Towards a Theory on the Roles and Functions of Sound in Audio Games

For the past few decades, researchers have increased our understanding of how sound functions within various audio–visual media formats. With a different focus in mind, this study aims to identify the roles and functions of sound in relation to the game form Audio Games, in order to explore the potential of sound when acting as an autonomous narrative form. Because this is still a relatively unexplored research field, the main purpose of this study is to help establish a theoretical ground and stimulate further research within the field of audio games. By adopting an interdisciplinary approach to the topic, this research relies on theoretical studies, examinations of audio games and contact with the audio game community. In order to reveal the roles of sound, the gathered data is analyzed according to both a contextual and a functional perspective. The research shows that a distinction between the terms ‘function’ and ‘role’ is important when analyzing sound in digital games. The analysis therefore results in the identification of two analytical levels that help define the functions and roles of an entity within a social context, named the Functional and the Interfunctional levels. In addition to successfully identifying three main roles of sound within audio games—each describing the relationship between sound and the entities game system, player and virtual environment—many other issues are also addressed. Consequently, and in accordance with its purpose, this study provides a broad foundation for further research of sound in both audio games and video games.

Transfer function-noise modeling and spatial interpolation to evaluate the risk of extreme (shallow) water-table levels in the Brazilian Cerrados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Postharvest Conservation of Mature-Green and Ripe 'Paluma' Guava Stored at Two Temperatures

This work aimed to establish the importance of maturation and ripeness stages and the use of refrigeration for the conservation of 'Paluma' guavas. Fruit picked at the mature-green and ripe stages were stored at ambient conditions (21 degrees C and 85% RH) and also at 10 degrees C (85% RH). The fruit were evaluated every 2 or 3 days for weight loss, appearance, decay, color, firmness, soluble solids, titratable acidity, ascorbic acid, total polyphenols extractable content and total antioxidant activity. The fruit stored at 21 degrees C had higher weight loss than those stored at 10 degrees C. Mature-green guavas at 21 degrees C remained in good quality for 6 days, but at 10 degrees C, the preservation period increased to 15 days. Ripe fruit were preserved for 4 days at 21 degrees C, which was extended with refrigeration to 6 days. Mature-green fruit at 21 degrees C had decay in 6 days; while at 10 degrees C decay happened in 18 days. The peel color of mature-green fruits, at 21 degrees C, showed increasing values of luminosity, indicating that its color became lighter (change from green to yellow) and at 10 degrees C it showed constant values until the end of storage. Pulp firmness of mature-green fruit declined during storage as a result of ripening. In ripe fruits such reduction occurred more slowly, since they were softer. The color of the pulp became intense red for mature fruits. Soluble solids were lower in ripe fruit at 21 degrees C, while in mature fruits at 10 degrees C, it increased. The titratable acidity increased in fruits stored at 10 degrees C. The fruits kept at 21 degrees C and the mature guavas kept at 10 degrees C showed no changes in ascorbic acid content. The ripe fruit at 10 degrees C maintained their ascorbic acid levels. Mature guavas, stored at 10 degrees C, had the longest shelf life and higher contents of soluble solids and titratable acidity, with no changes in total polyphenols extractable content and total antioxidant activity.

Chilling Injury in Avocados and Its Prevention with Thermal Treatment

The combinations of temperature and time which can cause chilling injuries in avocados 'Geada', 'Quintal' and 'Fortuna' were determined. The binomial 4 degrees C/ 28 days was selected to determine the activity of peroxidase (POD), polyphenoloxidase (PPO), polygalacturonase (PG) and methylesterase pectin (PME). The respiratory activity was also evaluated. The fruits were stored at this condition until being transferred to ambient conditions (22 degrees C and 77% RH) until maturity, when they were compared to fruits stored permanently at this environment, after being cleaned (control). In the second part of this work, different hydrothermal treatments were tested to prevent or minimize chilling injuries. Avocados 'Geada', 'Quintal' and 'Fortuna' were treated at 38 degrees C for 0, 30, 60 and 90 minutes before storage at 4 degrees C for 28 days. It was observed that the activity of enzymes associated to browning, POD and PPO, and to maturation, PG and PME, had become greater in fruits stored at 4 degrees C, or when they were transferred to environmental conditions. Fruits subjected to refrigeration, after transferred to environment, presented lower respiratory peak intensity and it occurred earlier than the others. Treatments using 38 degrees C for 60 and 90 min minimized the symptoms of chilling injury in avocados 'Geada' while for 'Quintal' the most efficient was 38 degrees C for 60 min. In 'Fortuna' these treatments did not minimize the damage by cold.

Egg quality during storage and deposition of minerals in eggs from quails fed diets supplemented with organic selenium, zinc and manganese

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estimation and evaluation of dynamic properties as indicators of changes on soil structure in sugarcane fields of São Paulo State - Brazil

The indiscriminate management and use of soils without moisture control has changed the structure of it due to the increment of the traffic by agricultural machines through the years, causing in consequence, a soil compaction and yield reduction in the areas of intensive traffic. The purpose of this work was to estimate and to evaluate the performance of preconsolidation pressure of the soil and shear stress as indicators of changes on soil structure in fields cropped with sugarcane, as well as the impact of management processes in an Eutrorthox soil structure located in São Paulo State. The experimental field was located in Piracicaba's rural area (São Paulo State, Brazil) and has been cropped with sugarcane, in the second harvest cycle. The soil was classified by Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) [Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), 1999. Centro Nacional de Pesquisa de Solos. Sistema Brasileiro de Classificao de Solos, Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), Brasilia, 412 pp.] as an Eutrorthox. Undisturbed samples were collected and georeferenced in a grid of 60 m x 60 m from two depths: 0-0.10 m (superficial layer - SL) and in the layer of greatest mechanical resistance (LGMR), previously identified by cone index (CI). The investigated variables were pressure preconsolidation (sigma(p)), apparent cohesion (c) and internal friction angle (phi). The conclusions from the results were that the SLSC was predicted satisfactorily from up as a function of soil moisture; thus, decisions about machinery size and loading (contact pressures) can be taken. Apparent cohesion (c), internal friction angle (phi) and the Coulomb equation were significantly altered by traffic intensity. The sigma(p), c and phi maps were shown to be important tools to localize and visualize soil compaction and mechanical resistance zones. They constitute a valuable resource to evaluate the traffic impact in areas cropped with sugarcane in State of São Paulo, Brazil. (C) 2008 Elsevier B.V. All rights reserved.