42 research outputs found

    Umbilicity of constant mean curvature hypersurfaces into space forms

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    In this paper we establish conditions on the length of the traceless part of the second fundamental form of a complete constant mean curvature hypersurface immersed in a space of constant sectional curvature in order to show that it is totally umbilical.Comment: 14 pages, comments welcom

    Effect of oxygen reducing atmospheres on the quality and safety of stored shelled Brazil nut packs

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    High moisture content, relative humidity, temperature and environment rich in oxygen (O2) are the main factors for tree nuts to get infected by fungi and so aflatoxins (AFLs) contaminated. During storage and commercialization dry Brazil nuts packs need to maintain their safety and quality. Modified atmospheres in storage (macro-environment) and packaging (micro-environment) have been used to prolong food shelf life by reducing O2 concentration with inhibitory gases or, more recently, by adding O2 absorber pads. This work reports the application of O2 atmosphere reducing methods on stored shelled Brazil nut packs aiming fungi and AFL degradation as well as hygienic conditions improvements. The methods applied were: (a) ozone - O3, (b) carbon dioxide - CO2 and (c) O2 absorber pads with and without vacuum. Nuts were submitted to microbiological tests (fungi, aflatoxigenic strains, yeast and bacteria), moisture content and AFLs analysis. From all O2 reducing atmosphere evaluated, the best performance was obtained with O3. A reduction on fungi growth (1.8 x 104 cfu.g-1 to 2.6 x 10 cfu.g-1) and yeast destruction after the first month of storage were registered. Also O3 was the only nut treatment that was able to degrade AFLs. None of the spiked (AFLs: 15 ppb) nut samples O3 treated had AFLs detected up to the LOQ of the method (0.36 μg.kg-1 for AFB1+AFB2+AFG1+AFG2) i.e., much lower than the allowed by the European Union regulation (MRL: 4 and 2 ppb for total and AFB1, respectively), thus producing safer nuts. All other treatments stabilized and/or inhibited microorganisms growth. Add CO2 and O2 pads played an important role on nut quality. Further study will be carried out in order to adjust O3 concentration and application conditions for longer period of storage

    Monitoring System for Agrometeorological Application with Voice-Controlled Interface

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    The objective of this work is to present aspects about the already completed development stages of a monitoring system for agrometeorological application that uses Human-Computer Interface controlled by written and spoken languages. Technologies related to the development of this type of HCI have been increasingly used and are gradually more connected to the most diverse devices and machines including fieldwork uses. This interdisciplinary work is supported by research in the areas of Meteorology, Linguistics, Natural Language Processing (NPL) and Computing using physical prototypes focused on monitoring: automated solar search, unmanned aerial vehicle (UAV), unmanned groundvehicle (UGV), mix of meteorological sensors and the system itself. The steps already completed and interrelated - automated solar tracker, the set of meteorological sensors and the system - show that this type of monitoring has a significant degree of accuracy, low cost and autonomy - it does not depend on the conventional grid and makes small decisions

    Diversidade genética ente progênies de macaúba na fase de muda.

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    A macaúba (Acrocomia aculeata) é uma palmeira arborescente, espinhosa, de até 20 m de altura. Conhecer a diversidade genética desta espécie é importante para o inicio do melhoramento. Assim, o objetivo deste trabalho foi determinar a divergência genética e agrupar 15 progênies de macaúba, baseado nas características da muda através de análise multivariada. Quinze matrizes de macaúba coletadas foram avaliadas quanto a duas características da planta na fase de muda. O experimento foi conduzido em blocos ao acaso, com cinco repetições e quinze genótipos. As características avaliadas das mudas com 12 meses de idade foram: Altura da Muda (cm) e Número de Folhas por muda. De acordo com os resultados obtidos para as características avaliadas observou-se a presença de variabilidade entre as 15 progênies. A existência de variabilidade genética entre as progênies permitiu separá-los pelo método de Tocher em oito grupos. As formações dos grupos variaram de uma a três progênies. O método utilizado agrupou as progênies com tendência da origem geográfica. Esta separação em grupos distintos é importante para o melhoramento genético da espécie

    RACEWALKING AND NORMAL WALKING ANALYSIS

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    INTRODUCTION: The purpose of the present study was to observe biomechanical variations in racewalking, starting from normal walking and continuing on up to a maximum racewalking performance supported by the athlete. Tests were carried out on a women’s racewalking team who represents Santa Catarina State at national competitions in Brazil. A GaitwayTM instrumented treadmill system was used to verify the differences between normal walking and racewalking. A few studies have been made of race walkers. Some physiological aspects indicated that the speed at which racewalking and running become equally efficient is similar to the crossover speed for conventional walking and running (Hagberg & Coyle, 1984). Another important study was done by Morgan & Martin (1986), who showed the effects of stride length alterations on racewalking economy. Their results support the hypothesis that trained subjects select locomotion patterns that are nearly optimal in terms of the aerobic demands. Cairns et al. (1986) determined that the racewalking gait exhibits some biomechanical characteristics which are different from the walking gait or running. Recently, Brisswalter et al. (1996) suggested that in well trained walkers the energy cost of walking increases with exercise duration, but walkers are able to maintain the same stride duration after the test when treadmill speed is controlled

    Asymptomatic HIV-people present different profile of sCD14, sRAGE, DNA damage and vitamins, according to the use of cART and CD4+ T cells restoration.

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    We aimed to analyze markers of immune activation, inflammation, and oxidative stress in 92 asymptomatic HIV-infected patients according to the adequate (AR, >500 cells/mm(3)) or inadequate (IR, nAR > LTNP > tAR > tIR. Higher levels of 8-isoprostane were observed in nIR. LTNP presented a higher retinol dosage than tAR and less genotoxic damage induced by oxidative stress than the other groups. We suggest that the therapy, despite being related to lesser immune activation and inflammation, alters the vitamin profile and consequently increases the oxidative stress of patients. In addition, the lowest genotoxic index for LTNP indicates that both VL and cART could be responsible for the increased DNA damage. More studies are needed to understand the influence of cART on persistent immune activation and inflammation
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