1,505 research outputs found

    Light with tunable non-Markovian phase imprint

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    We introduce a simple and flexible method to generate spatially non-Markovian light with tunable coherence properties in one and two dimensions. The unusual behavior of this light is demonstrated experimentally by probing the far field and recording its diffraction pattern after a double slit: In both cases we observe instead of a central intensity maximum a line or cross shaped dark region, whose width and profile depend on the non-Markovian coherence properties. Since these properties can be controlled and easily reproduced in experiment, the presented approach lends itself to serve as a testbed to gain a deeper understanding of non-Markovian processes

    Exploring frailty-related biomarkers and potential influence of environmental factors

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    Recent evidence advocates that healthy ageing may be possible, with morbidity compressed to later years. One area of concern is the burden of environmentally induced disease in susceptible populations. Older adults are a well-recognized susceptible population due to the decline of immune defences and the burden of multiple chronic diseases. As a susceptible population, the burden of environmentally induced disease and lifestyle factors is an increasing concern. Frailty is an age-related syndrome expected to increase over the next decades given the observed demographic shift. This syndrome has been identified to be the most common condition leading to disability, institutionalization and death in the older adults and the risk factors associated with its development are yet to be clarified. The main aim of the present study is to investigate a relation between frailty status, biomarkers and environmental exposures

    Production of fermented cheese whey-based beverage using kefir grains as starter culture : evaluation of morphological and microbial variations

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    Whey valorization concerns have led to recent interest on the production of whey beverage simulating kefir. In this study, the structure and microbiota of Brazilian kefir grains and beverages obtained from milk and whole/deproteinised whey was characterized using microscopy and molecular techniques. The aim was to evaluate its stability and possible shift of probiotic bacteria to the beverages. Fluorescence staining in combination with Confocal Laser Scanning Microscopy showed distribution of yeasts in macro-clusters among the grain’s matrix essentially composed of polysaccharides (kefiran) and bacteria. Denaturing gradient gel electrophoresis displayed communities included yeast affiliated to Kluyveromyces marxianus, Saccharomyces cerevisiae, Kazachatania unispora, bacteria affiliated to Lactobacillus kefiranofaciens subsp. Kefirgranum, Lactobacillus kefiranofaciens subsp. Kefiranofaciens and an uncultured bacterium also related to the genus Lactobacillus. A steady structure and dominant microbiota, including probiotic bacteria, was detected in the analyzed kefir beverages and grains. This robustness is determinant for future implementation of whey-based kefir beverages.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), CAPES-GRICES

    In Vitro Hepatotoxic and Neurotoxic Effects of Titanium and Cerium Dioxide Nanoparticles, Arsenic and Mercury Co-Exposure

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    This article belongs to the Special Issue Toxicity of Nanomaterials and Legacy Contaminants: Risks to the Environment and Human Health.Considering the increasing emergence of new contaminants, such as nanomaterials, mixing with legacy contaminants, including metal(loid)s, it becomes imperative to understand the toxic profile resulting from these interactions. This work aimed at assessing and comparing the individual and combined hepatotoxic and neurotoxic potential of titanium dioxide nanoparticles (TiO2NPs 0.75-75 mg/L), cerium oxide nanoparticles (CeO2NPs 0.075-10 μg/L), arsenic (As 0.01-2.5 mg/L), and mercury (Hg 0.5-100 mg/L) on human hepatoma (HepG2) and neuroblastoma (SH-SY5Y) cells. Viability was assessed through WST-1 (24 h) and clonogenic (7 days) assays and it was affected in a dose-, time- and cell-dependent manner. Higher concentrations caused greater toxicity, while prolonged exposure caused inhibition of cell proliferation, even at low concentrations, for both cell lines. Cell cycle progression, explored by flow cytometry 24 h post-exposure, revealed that TiO2NPs, As and Hg but not CeO2NPs, changed the profiles of SH-SY5Y and HepG2 cells in a dose-dependent manner, and that the cell cycle was, overall, more affected by exposure to mixtures. Exposure to binary mixtures revealed either potentiation or antagonistic effects depending on the composition, cell type and time of exposure. These findings prove that joint toxicity of contaminants cannot be disregarded and must be further explored.This research was funded by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia in the framework of the project POCI-01-0145-FEDER-029651. This work was also financed by national funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of projects UIDB/04750/2020 and LA/P/0064/2020. This work was also developed within the scope of the project CICECO- Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC). A.T. Reis thanks the financial support of FCT through individual Grant SFRH/BPD/122112/2016. C.B. Lopes and A.C. Estrada acknowledge their research position funded by national funds (OE), through FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.info:eu-repo/semantics/publishedVersio

    High -and moderate-intensity resistance training provokes different effects on body composition, functionality, and well-being in elderly

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    Purpose: To compare the short-term effects of a resistance training program with elastic bands at moderate and high intensity on the body composition, functional capacity, and well-being of overweight and obese older women. Method: 75 women (68.7 ± 4.7 years) were assigned to a control group (n = 25) or to one of two treatment groups: (i) high intensity (G6 = 6 repetitions, n = 25) and (ii) moderate intensity (G15 = 15 repetitions, n = 25). Body composition (fat and fat-free mass), functional capacity (isometric strength; 30-s-arm-curl, 30-s-chair-stand, timed up & go test, and 6-min-walk-test [6MWT]), and well-being were evaluated before and after 8 weeks of intervention by using the 36-Item-Short-Form-Survey (SF-36). Results: 61 participants completed the study. The G15 group generated greater positive changes in the percentages of total and segmental fat mass (≃2.8%, p ≤ .05) and better performance in the 6MWT than the other groups. The G6 group showed greater improvements in the timed up & go and muscle strength tests than the G15 group. The G6 and G15 groups showed significant improvements in the following sections of SF-36: general health perceptions, physical functioning, mental health, and vitality. The performance of all variables worsened in the control group. Conclusions: The 8 weeks of intervention caused positive and significant changes in all study variables, although the results confirmed that this duration is insufficient to generate clear differences according to the level of exercise intensity. Nevertheless, G15 caused greater improvements in the percentage of fat mass and in aerobic resistance, whereas G6 improved the lower-limb muscle strength.This work was supported by the grant Ignacio Larramendi 2014 from the Mapfre Foundation (Code: OTR2015-140931NVES). Pedro Gargallo was supported by a predoctoral scholarship (FPU15/05634) awarded by the Spanish Ministry of Education, Culture, and Sport

    Transience analysis of bursty traffic with erbium doped fiber amplifiers

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    Copyright © [2009] IEEE. Reprinted from ICTON 2009. ISBN 978-1-4244-4826-5. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.In this paper, we investigate experimentally the impact of optical amplifiers, namely Erbium Doped Fiber Amplifiers (EDFA) on Optical Burst Switching (OBS) networks, operating at 2.5 Gb/s (typical bit rate for current passive optical networks - PON). Bursts with 212 – 1 and 216 – 1 pseudo random binary sequence (PRBS) were studied, with different idle times. The use of traffic with variable idle time was assessed in order to evaluate the effect on the burst initial amplitude. We also analyzed the performance of the packet based system by measuring the Q factor at the receiver and concluded that the performance is not affected by the type of traffic (variable or fixed idle times)

    The Effects of the Type of Exercise and Physical Activity on Eating Behavior and Body Composition in Overweight and Obese Subjects

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    The aim of this study was to examine whether a type of exercise favors better compliance with a prescribed diet, higher eating-related motivation, healthier diet composition or greater changes in body composition in overweight and obese subjects. One hundred and sixty-two (males n = 79), aged 18-50 years, were randomized into four intervention groups during 24 weeks: strength, endurance, combined strength + endurance and guideline-based physical activity; all in combination with a 25-30% caloric restriction diet. A food frequency questionnaire and a "3-day food and drink record" were applied pre- and post-intervention. Diet and exercise-related motivation levels were evaluated with a questionnaire developed for this study. Body composition was assessed by DXA and habitual physical activity was measured by accelerometry. Body weight, body mass index (BMI) and body fat percentage decreased and lean body mass increased after the intervention, without differences by groups. No interactions were observed between intervention groups and time; all showing a decreased in energy intake (p < 0.001). Carbohydrate and protein intakes increased, and fat intake decreased from pre- to post-intervention without significant interactions with intervention groups, BMI category or gender (p < 0.001). Diet-related motivation showed a tendency to increase from pre- to post-intervention (70.0 ± 0.5 vs 71.0 ± 0.6, p = 0.053), without significant interactions with intervention groups, BMI or gender. Regarding motivation for exercise, gender x time interactions were observed (F(1,146) = 7.452, p = 0.007): Women increased their motivation after the intervention (pre: 17.6 ± 0.3, post: 18.2 ± 0.3), while men maintained it. These findings suggest that there are no substantial effects of exercise type on energy intake, macronutrient selection or body composition changes. After a six-month weight loss program, individuals did not reduce their motivation related to diet or exercise, especially women. Individuals who initiate a long-term exercise program do not increase their energy intake in a compensatory fashion, if diet advices are included.The PRONAF Study takes place with the financial support of the Ministerio de Ciencia e Innovación, Convocatoria de Ayudas I+D 2008, Proyectos de Investigación Fundamental No Orientada, del VI Plan de Investigación Nacional 2008-2011, (Contract: DEP2008-06354-C04-01). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001

    Production and characterization of protease from Penicillium aurantiogriseum URM 4622

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    Proteases with new properties are required due to their increasing industrial importance. In this work, the optimal fermentation conditions for the production of a protease from Penicillium aurantiogriseum dierchx (URM-4622) are presented together with partial characterization of the protease catalytic properties. The batch fermentation conditions that allow for the highest specific proteolytic activity are 26 ºC, pH 7.0, and 25 % saturation dissolved O2 concentration. The obtained protease is stable over a wide range of pH (5.8 to 9.5) and temperature (25 to 40 ºC) values. In the presence of Zn2+ a 26 % reduction in the enzyme proteolytic activity occurs and, in contrast, Mn2+ enhances its activity by 28.9 %. 96.2 % and 70.8 % of the protease activity are maintained after 90 min incubation in 5 and 10 % (v/v) H2O2 aqueous solutions, respectively. PMSF inhibition reveals that this enzyme is a serine protease. Protease is able to hydrolyze different proteins
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