4,407 research outputs found
Weighted automata as coalgebras in categories of matrices
The evolution from non-deterministic to weighted automata represents a shift from qual- itative to quantitative methods in computer science. The trend calls for a language able to reconcile quantitative reasoning with formal logic and set theory, which have for so many years supported qualitative reasoning. Such a lingua franca should be typed, poly- morphic, diagrammatic, calculational and easy to blend with conventional notation.
This paper puts forward typed linear algebra as a candidate notation for such a unifying role. This notation, which emerges from regarding matrices as morphisms of suitable categories, is put at work in describing weighted automata as coalgebras in such categories.
Some attention is paid to the interface between the index-free (categorial) language of matrix algebra and the corresponding index-wise, set-theoretic notation.Fundação para a Ciência e a Tecnologia (FCT
Screening \u3ci\u3eBrachiaria\u3c/i\u3e Hybrids for Resistance to the Pasture Spittlebug \u3ci\u3eNotozulia entreriana\u3c/i\u3e (Berg, 1879) (Hemiptera: Cercopidae) in Central Brazil
Design and implementation of a real-time wireless sensor network
This paper describes the development of wireless
sensor network prototype that gathers biometrical data
and posture information from several wearable sensor
networks and sends it in real-time to a personal
computer where the information is monitored and
stored. The wireless sensor network is based on a low
power real-time MAC protocol that was designed and
implemented in the MICAz platform. This paper also
presents some analytical results and several
experimental results regarding the behavior of the
developed system.Fundação para a Ciência e a Tecnologia (FCT
Codon-triplet context unveils unique features of the Candida albicans protein coding genome
<p>Abstract</p> <p>Background</p> <p>The evolutionary forces that determine the arrangement of synonymous codons within open reading frames and fine tune mRNA translation efficiency are not yet understood. In order to tackle this question we have carried out a large scale study of codon-triplet contexts in 11 fungal species to unravel associations or relationships between codons present at the ribosome A-, P- and E-sites during each decoding cycle.</p> <p>Results</p> <p>Our analysis unveiled high bias within the context of codon-triplets, in particular strong preference for triplets of identical codons. We have also identified a surprisingly large number of codon-triplet combinations that vanished from fungal ORFeomes. <it>Candida albicans </it>exacerbated these features, showed an unbalanced tRNA population for decoding its pool of codons and used near-cognate decoding for a large set of codons, suggesting that unique evolutionary forces shaped the evolution of its ORFeome.</p> <p>Conclusion</p> <p>We have developed bioinformatics tools for large-scale analysis of codon-triplet contexts. These algorithms identified codon-triplets context biases, allowed for large scale comparative codon-triplet analysis, and identified rules governing codon-triplet context. They could also detect alterations to the standard genetic code.</p
Spectrophotometric characterization of simple glazings for a modular façade
A large variety of transparent materials is available for uses in buildings façades and all glazing properties must be considered in their choice. Such a selection should be a careful process of evaluation and weighing of tradeoffs. The correct glazing specifications for façades can reduce energy consumption in buildings, because the heat exchange and passage of radiation into the building as light and heat occur through transparent surfaces. Therefore, glazing significantly contributes to the heat transfer between outdoor and indoor spaces, which act directly on daylighting and thermal comfort. This manuscript addresses a spectrophotometric characterization of glazings for the study of components for the design of a modular façade system based on the climate of Portugal. The study focused on results of spectrophotometric measurements of an optical behavior in different solar spectrum intervals (ultraviolet, visible and near infrared), specifically the transmittance of some types of simple glazings. The results show the percentage of transmission to spectrum intervals, which enabled the analysis (OK?) of the efficiency of the glazing regarding daylighting and correlation to the thermal performance. Indications for specifications and adequate uses based on transmission of transparent surfaces have been obtained and complemented the datasheets available from the manufactures.The authors gratefully acknowledge the financial support provided by Erasmus Mundus ISAC – Improving Skills Across Continents for this research.info:eu-repo/semantics/publishedVersio
Soil class map of the Rio Jardim watershed in Central Brazil at 30 meter spatial resolution based on proximal and remote sensed data and MESMA method
Geospatial soil information is critical for agricultural policy formulation and decision making, land-use suitability analysis,
sustainable soil management, environmental assessment, and other research topics that are of vital importance to agriculture
and economy. Proximal and Remote sensing technologies enables us to collect, process, and analyze spectral data and to retrieve, synthesize, visualize valuable geospatial information for multidisciplinary uses. We obtained the soil class map provided in this article by processing and analyzing proximal and remote sensed data from soil samples collected in toposequences based on
pedomorphogeological relashionships. The soils were classified up to the second categorical level (suborder) of the Brazilian Soil
Classification System (SiBCS), as well as in the World Reference Base (WRB) and United States Soil Taxonomy (ST) systems. The raster map has 30 m resolution and its accuracy is 73% (Kappa coefficient of 0.73). The soil legend represents a soil class followed by its topsoil color
Gellan-gum coated gold nanorods: a new tool for biomedical applications
Publicado em "Frontiers in Bioengineering and Biotechnology. Conference Abstract: 10th World Biomaterials Congress"Introduction: Gold nanorods (AuNRs) have been widely studied, in the scope of cancer research and biomedical applications [1]. Their optical properties, easy synthesis and high surface area make AuNRs an outstanding tool for a plethora of applications, such as drug delivery, imaging and tissue engineering [2]. However, before biomedical usage, it is necessary to modify AuNRs surface chemistry, to improve their biocompatibility and stability under biological conditions [3]. One possible approach is the use of biocompatible natural-based polymers that enhance AuNRs performance while allowing the controlled release of drugs/bioactive agents. Herein, we report the successful preparation of a core-shell nanostructure using low-acyl gellan gum (GG) [4], [5] for the coating of AuNRs.
Methods: AuNRs were prepared following the seed-mediated growth method [6]. Then, particles were coated with a successive deposition of anionic and cationic polyelectrolytes (poly(acrylic acid) and poly(allylamine hydrochloride), respectively). The pre-coated nanorods were added to a low-acyl gellan gum (GG) solution, previously heated at 90ºC to allow dissolution, and the mixture was stirred overnight at room temperature. The GG-coated AuNRs (AuNR-GG) were characterized by UVvisible spectrometry, zeta potential measurements and transmission electron microscopy (TEM). AuNRs cytotoxicity was accessed in vitro after 1, 3, 7 and 14 days of SaOS-2 cell culture, using an MTS assay. Nanoparticles internalization was confirmed by TEM. In vivo biocompatibility tests were also performed by delivering a solution of AuNRs-GG via tail injection in mice.
Results and Discussion: AuNRs were successfully synthesized and coated with a GG shell of approximately 7 nm, as shown in Figure 1. The presence of the GG around AuNRs clearly improved particles stability at different salt and pH conditions, as observed by UV-vis spectroscopy. The in vitro studies using SaOS-2 showed that AuNRs-GG are noncytotoxic. TEM analyses have confirmed that nanoparticles are uptaken by cells and aggregate within cytoplasmic vesicles as depicted in Figure 2. Additionally, in vivo tests suggest that AuNRs are harmless for mice after 24 hours.
Conclusion: In this study, AuNRs were individually coated with a gellan gum (GG) shell, resulting in nanoparticles with enhanced stability under different salt concentrations and range of pH’s. Thence, one can conclude that the GG present around the nanoparticles acts as a stabilizer, improving AuNRs stability and biocompatibility. AuNRs-GG have shown noteworthy features and a high potential for further use on biomedical applications including intracellular drug delivery and imaging.QREN (ON.2 – NORTE-01-0124-FEDER-000018) co-financed by North Portugal Regional Operational Program (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF)The Portuguese Foundation for Science and Technology (FCT) - SFRH/BD/102710/201
Study of tinctorial behaviour of curaua and banana fibres
The ecological benefits of renewable raw materials are clear: they save valuable resources, are environmentally sound and do not cause health problems. Natural fibres have already established a track record in several different areas such as, civil, automobiles, architecture, medicine among others. Numerous investigations are carried out in order to create added value to natural fibre materials such as the stem of the banana tree that are usually discarded in the environment. Curaua, another important natural substrate, is an Amazon-forest plant (Ananas erectifolius) that resembles a pineapple plant. Curaua leaf fibres display a low-production cost and offer a relatively high tensile strength level. Despite these naturals fibres are well established as reinforce in composite materials, the dyeing properties of curaua and banana fibres are not well studied yet.This work is supported by Portuguese National Funding, through FCT - Fundação para a Ciência e a Tecnologia, on the framework of project UID/CTM/00264/2013
Wireless hydrotherapy smart-suit network for posture monitoring
A wireless smart-suit network for monitoring body
kinetics, heart and respiratory rate during hidrocinesiotherapy
sessions is presented. Sensing modules composed by 3-axis
accelerometers, 3-axis magnetometers and interface electronics
are used to monitor the body kinetics. Heart rate is measured
using an ear clip infrared sensor and respiratory frequency is
measured with inductance plethysmography. The sensor network
is integrated in a swimming suit and data is transmitted in real
time to a base station using a 2.4 GHz RF transceiver.
Measurements of the rotation of shoulders, hips and spine are
performed with a resolution of less than 2 degrees. A new MAC
protocol for wireless sensing and actuation, LPRT protocol,
implemented in MICAz motes is used. Some of the characteristics
of the proposed protocol are low power consumption, real-time
support and loss intolerant traffic. The protocol uses contentionfree
operation and retransmission scheme and is very flexible and
has high throughput efficiency.Agência de Inovação (ADI
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