801 research outputs found
Towards a Generic Trace for Rule Based Constraint Reasoning
CHR is a very versatile programming language that allows programmers to
declaratively specify constraint solvers. An important part of the development
of such solvers is in their testing and debugging phases. Current CHR
implementations support those phases by offering tracing facilities with
limited information. In this report, we propose a new trace for CHR which
contains enough information to analyze any aspects of \CHRv\ execution at some
useful abstract level, common to several implementations. %a large family of
rule based solvers. This approach is based on the idea of generic trace. Such a
trace is formally defined as an extension of the semantics of
CHR. We show that it can be derived form the SWI Prolog CHR trace
Design e ergonomia: aspectos tecnológicos
Nesta coletânea são apresentadas diferentes questões, métodos de abordagem e demandas para a aplicação da Ergonomia no Design. A evolução tecnológica observada nas últimas décadas proporcionou inúmeros benefÃcios para o aumento na qualidade de vida das pessoas, mas também resultou em vários problemas de interface tecnológica, os quais geram constrangimentos, acidentes, e frustração aos consumidores. Tais questões são analisadas no livro, no qual se destacam temas de grande atualidade, como por exemplo: o uso de equipamentos médico-hospitalares por indivÃduos obesos e de cadeiras de rodas por indivÃduos idosos; as avaliações ergonômicas de espaços e equipamentos escolares; as dificuldades de leitura em rótulos e bulas de embalagens; o uso de colete de proteção nas atividades policiais, de calçados femininos com salto alto ou da poltrona do motorista de ônibus urbano, entre outros. Os artigos relatam pesquisas desenvolvidas no Programa de Pós-graduação em Design da UNESP, Campus Bauru, e ressaltam a importância da aplicação da ergonomia no design de produtos e sistemas, com a finalidade de se desenvolver tecnologias para melhorar a qualidade de vida humana
N-acetylcysteine attenuates the progression of chronic renal failure
N-acetylcysteine attenuates the progression of chronic renal failure.BackgroundLipid peroxidation impairs renal function. Aldosterone contributes to renal injury in the remnant kidney model. This study aimed to determine the effects of the antioxidant N-acetylcysteine (NAC) on renal function and aldosterone levels in chronic renal failure.MethodsAdult male Wistar rats were submitted to 5/6 nephrectomy or laparotomy (sham-operated) and received NAC (600 mg/L in drinking water, initiated on postoperative day 7 or 60), spironolactone (1.5 g/kg of diet initiated on postoperative day 7), the NAC-spironolactone combination or no treatment. Clearance studies were performed on postoperative days 21, 60, and 120.ResultsMean daily NAC and spironolactone ingestion was comparable among the treated groups. Mean weight gain was higher in NAC-treated rats than in untreated rats. A significant decrease in urinary thiobarbituric acid reactive substances (TBARS) concentrations, a lipid peroxidation marker, was observed in NAC-treated rats. By day 120, glomerular filtration rate (GFR), which dropped dramatically in untreated rats, was stable (albeit below normal) in NAC-treated rats, which also presented lower proteinuria, glomerulosclerosis index, and blood pressure, together with attenuated cardiac and adrenal hypertrophy. These beneficial effects, observed even when NAC was initiated on postnephrectomy day 60, were accompanied by a significant reduction in plasma aldosterone and urinary sodium/potassium ratio. The NAC-spironolactone combination lowered blood pressure and improved GFR protection.ConclusionThe NAC-spironolactone combination improves renal function more than does NAC alone. In the remnant kidney model, early or late NAC administration has a protective effect attributable to decreased plasma aldosterone and lower levels of lipid peroxidation
Fiber Post Etching with Hydrogen Peroxide: Effect of Concentration and Application Time
AbstractIntroductionEtching is necessary to expose the fibers and enable both mechanical and chemical bonding of the resin core to the fiber post. This study evaluated the effect of concentration and application time of hydrogen peroxide on the surface topography and bond strength of glass fiber posts to resin cores.MethodsFiber posts were etched with 24% or 50% hydrogen peroxide for 1, 5, or 10 min (n = 10). Posts without any treatment were used as a control. After etching, the posts were silanated and adhesive resin was applied. The posts were positioned into a mold to allow a self-cured resin core to be inserted. The post/resin assembly was serially sectioned into five beams that were subjected to a tensile bond strength test. Data were subjected to two-way ANOVA and Tukey test (α = 0.05). The surface topography was analyzed using scanning electronic microscopy.ResultsNon-etched post presents a relatively smooth surface without fiber exposure. Application of hydrogen peroxide increased the surface roughness and exposed the fibers. All experimental conditions yielded similar bond strength values that were higher than those obtained in the control group.ConclusionBoth 24% and 50% hydrogen peroxide exposure increased the bond strength of resin to the posts, irrespective of the application time
A natural interface for remote operation of underwater robots
Nowadays, an increasing need of intervention robotic systems can be observed in all kind of hazardous environments. In all
these intervention systems, the human expert continues playing a central role from the decision-making point of view. For
instance, in underwater domains, when manipulation capabilities are required, only Remote Operated Vehicles, commercially
available, can be used, normally using master-slave architectures and relaying all the responsibility in the pilot. Thus, the role
played by human- machine interfaces represents a crucial point in current intervention systems. This paper presents a User Interface
Abstraction Layer and introduces a new procedure to control an underwater robot vehicle by using a new intuitive and immersive
interface, which will show to the user only the most relevant information about the current mission. We conducted an experiment and
found that the highest user preference and performance was in the immersive condition with joystick navigation.This research was partly supported by Spanish Ministry of Research and Innovation DPI2011-27977-C03 (TRITON Project)
Design and evaluation of a natural interface for remote operation of underwater roter
Nowadays, an increasing need of intervention robotic systems can be observed in all kind of hazardous environments. In all these intervention systems, the human expert continues playing a central role from the decision making point of view. For instance, in underwater domains, when manipulation capabilities are required, only Remote Operated Vehicles, commercially available, can be used, normally using master-slave architectures and relaying all the responsibility in the pilot. Thus, the role played by human- machine interfaces represents a crucial point in current intervention systems. This paper presents a User Interface Abstraction Layer and introduces a new procedure to control an underwater robot vehicle by using a new intuitive and immersive interface, which will show to the user only the most relevant information about the current mission. Finally, some experiments have been carried out to compare a traditional setup and the new procedure, demonstrating reliability and feasibility of our approach.This research was partly supported by Spanish Ministry
of Research and Innovation DPI2011-27977-C03 (TRITON
Project)
Seismic characterization of fluid migration and Pockmarks in the Estremadura Spur, West Iberian Margin, Portugal
Recently a field with more than 70 pockmarks was discovered in the NW region of the Estremadura Spur
outer shelf (West Iberian margin), a trapezoidal promontory elongated in an east-west direction, between Cabo
Carvoeiro and Cabo da Roca, extending until the Tore seamount.
Pockmarks are the seabed culminations of fluid migration through the sedimentary column and their characteristic
seabed morphologies correspond to cone-shaped circular or elliptical depressions. These features and the
associated fluid escape process are the main objectives of this work. Here we characterize these structures to
understand their structural and stratigraphic control based on: 1) Seismic processing and interpretation of the high
resolution 2D single-channel sparker seismic dataset, 2) Bathymetric and Backscatter interpretation and 3) ROV
direct observation of the seafloor.
The analysis of the seismic profiles allowed the identification of six seismic units, disturbed by the migration
and accumulation of fluids. The Estremadura Spur outer shelf has been affected by several episodes of fluid
migration and fluid escape during the Pliocene-Quaternary that are expressed by a vast number of seabed and
buried pockmarks. At present, the pockmarks are mainly inactive, as the seabed pockmarks are covered by recent
sediments. The stacking of various pockmarks suggests a cyclical fluid flow activity that can possibly be the result
of the eustatic sea level variations and the subsequent changes of the hydrostatic pressure. The origin of the seep
fluids is still under debate but considering the low-sedimentation rate of the area and the low productivity a deep
source for the fluids is most probable, possibly related with the Jurassic hydrocarbon system. It was concluded
that the migration of fluids to the seabed occurred over the Pliocene-Quaternary in several episodes, as indicated
by the buried pockmarks at different depths.
Acknowledgements: This work was carried out in the framework of the PES project - Pockmarks and
fluid seepage in the Estremadura Spur: implications for regional geology, biology, and petroleum systems
(PTDC/GEOFIQ/5162/2014) financed by the Portuguese Foundation for Science and Technology (FCT). The
seismic dataset was acquired within the PACEMAKER project funded by the European Research Council
(ERC) under the European Union’s Seventh Framework Program (FP7/2007-2013) ERC agreement (226600).
The Instituto Portugues do Mar e da Atmosfera acknowledges support by Landmark Graphics (SeisWorks) via
the Landmark University Grant Program. We thank the Estrutura de Missão para a Extensão da Plataforma
Continental (EMEPC) for allowing me to have access and use the data collected in the Estremadura Spur during
the EMEPC/PEPC/LUSO/2015 cruise and the ROV Luso team. We also thank Prof. Dr. Luis Matias (FCUL &
IDL) for the help with SPW and processing steps
How is copepod functional diversity shaped by 2015-2016 El Niño and seasonal water masses in a coastal ecosystem of Southwest Atlantic?
Functional traits, short life cycles, and the pivotal role in the ocean make copepod diversity a solid foundation forassessing the effect of global changes in marine food webs and ecosystem functioning. Climate change and extremeevents, particularly El Niño, can affect coastal ecosystems. The Arvoredo Marine Biological Reserve (MPA), locatedin highly productive coastal waters of the Southern Brazilian Bight, presents complex climate and oceanographicconditions. This study investigates the influence of oceanographic processes and El Niño 2015-2016 on the copepodfunctional diversity from 2014 to 2016 in the Arvoredo MPA. Horizontal tows were performed using a WP2 net witha mesh size of 200 µm. The 41 species accounted for 19 functional entities and four functional groups. Our findingsreveal that the seasonal intrusion of water masses influenced copepod functional diversity. During summer, theupwelling of South Atlantic Central Water increased nutrient availability and favored large herbivore-omnivoresand carnivores. The Plata Plume Water enrichment during winter coincided with a decline in functional richness andabundance, leading to the predominance of the Oithona nana, a small-sized omnivore. Compensatory mechanismswere observed as functional equivalence and species composition shifts. Acartia lilljeborgii and Temora turbinataexhibited functional equivalence and compensated for each other in response to salinity changes associatedwith upwelling and El Niño. The copepod assemblage demonstrated the ability to maintain functional diversity despitechanges in copepod abundance. However, the decline in functional diversity and abundance during the intense winterindicated potential disruption in trophic dynamics and ecosystem functioning. Maintaining balance and compensatingfor disturbances such as El Niño is crucial for marine food web resilience. The functional trait approach provided acomprehensive understanding of the copepod assemblage in Arvoredo MPA, contributing to a broader knowledgeof the impact of oceanographic processes intensification. Monitoring functional diversity and abundance is crucial forevaluating the effects of copepod assemblage changes in ecosystem functionings
Qualidade ovocitária de tambaqui (Colossoma macropomum) ao longo da estação reprodutiva
The study aimed to analyze the Colossoma macropomum reproductive behavior and quality of the female gametes throughout the reproductive season. The experiment was carried out in Pimenta Bueno - Rondônia State (Northern Brazil) during the reproductive season (2010-2011) using 36 females. Each sampling was performed on a 15 ± 5 days interval. Female gametes were collected by stripping and the following analyses were performed: weight of oocytes released (g); productivity index, fertilization and hatching rate. During the sampling period was verified effect (p < 0.05) of collecting time into the season for oocytes weight, productivity index and fertilization rate. Although the period 3 (December) did not differ significantly from other periods, it showed better parameters for the quality of C. macropomum oocytes.O estudo foi conduzido com o objetivo de analisar o comportamento reprodutivo da espécie Colossoma macropomum, quanto à qualidade de seus gametas femininos ao longo da estação reprodutiva. O experimento foi executado em Pimenta Bueno-Rondônia durante a estação reprodutiva do C. macropomum. Utilizaram 36 fêmeas durante a estação de 2010-2011. Cada coleta apresentou um intervalo de 15±5 dias. Através da extrusão foram coletados os gametas femininos e realizadas as seguintes análises ao longo da estação: peso de oócitos liberados (g); Ãndice de produtividade; taxa de fertilização e eclosão. Durante a estação 2010-2011 foi verificado efeito (p < 0,05) de perÃodo (coleta) dentro da estação para peso de oócitos, Ãndice de produtividade e taxa de fertilização. Apesar do perÃodo 3 (coleta – mês de dezembro) não ter diferenciado significativamente de alguns perÃodos, foi o que apresentou os melhores parâmetros estabelecidos para a qualidade dos oócitos de C. macropomum
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