731 research outputs found

    Detection of Earth-like Planets Using Apodized Telescopes

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    The mission of NASA's Terrestrial Planet Finder (TPF) is to find Earth-like planets orbiting other stars and characterize the atmospheres of these planets using spectroscopy. Because of the enormous brightness ratio between the star and the reflected light from the planet, techniques must be found to reduce the brightness of the star. The current favorite approach to doing this is with interferometry: interfering the light from two or more separated telescopes with a π\pi phase shift, nulling out the starlight. While this technique can, in principle, achieve the required dynamic range, building a space interferometer that has the necessary characteristics poses immense technical difficulties. In this paper, we suggest a much simpler approach to achieving the required dynamic range. By simply adjusting the transmissive shape of a telescope aperture, the intensity in large regions around the stellar image can be reduced nearly to zero. This approach could lead to construction of a TPF using conventional technologies, requiring space optics on a much smaller scale than the current TPF approach.Comment: Accepted for publication in ApJ Letters, 9 pages, 6 figure

    Understanding olive oil stability using filtration and high hydrostatic pressure

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    Veiled extra virgin olive oil (VEVOO) is very attractive on the global market. A study was performed to highlight the role of different amounts of water and microorganisms on the evolution of VEVOO quality during storage, using the selective effects of the application of individual or combined filtration and high hydrostatic pressure (HHP) treatments. Four oil processing trials were carried out in four replicates, resulting in a full factorial design with two independent fixed factors: filtration and HPP treatments. The turbidity of all the olive oil samples was characterized. Furthermore, all the olive oil samples were analysed for legal parameters, volatile organic compounds and phenolic compounds during the storage tests. The microbial contamination in the presence of a high level of water activity (>0.6 Aw) was related to the formation of volatile aroma compounds, which were responsible for the \u201cfusty\u201d sensory defect. Furthermore, high water activity values were related to an increase in the hydrolytic degradation rate of the phenolic compounds. The oil turbidity has to be planned and controlled, starting from adjustment of the water content and application of good manufacturing practices

    Winemaking Byproducts as Source of Antioxidant Components : Consumers’ Acceptance and Expectations of Phenol-Enriched Plant-Based Food

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    One of the food industry\u2019s priorities is to recover byproducts and move towards more sustainable systems. Among wine-chain byproducts, unripe grapes represent a promising source of antioxidants. However, the development of new foods enriched using phenol-rich ingredients is challenging due to their sensory attributes. The aims of the present study were to (1) use phenol-rich extract from unripe grapes to enrich a model plant-based food (beetroot puree\u2014BP); (2) evaluate consumers\u2019 acceptance and expectations for the beetroot pur\ue9e samples. The effect of information about the sustainability and pro-health activity of value-added ingredients on consumers\u2019 responses was also investigated. Four beetroot purees with increasing concentrations of phenol extract (0\u20131.93 g/kg) added were evaluated by 101 participants in three tasting conditions (blind: only samples; expected: only information without tasting; real: both samples and information).Liking slightly decreased with increasing concentrations of phenol extract, even if all the samples were considered acceptable. The health and sustainability information increased the hedonic expectations, although it was not assimilated by all consumers involved. The development of new phenol-enriched foods using functional ingredients from unripe grapes is challenging. However, it is also promising, since all the samples were generally accepted by the consumers and they presented phenol levels that were stable over time and that could have positive health effects when consumed

    Filtration scheduling: Quality changes in freshly produced virgin olive oil

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    Filtration is the most widespread stabilisation operation for extra virgin olive oil, preventing microbial and enzymatic changes. However, during the harvest, the workload of olive mills is at its peak. This results in two approaches to filtration: (i) delays it until after harvesting, increasing the risk of degraded oil quality, and (ii) filters it immediately, increasing the workload. The aim of our experiment is to assess the risk of delaying filtration and establish a safe delay time. Changes in the sensory profile and volatile compound contents were evaluated during 30 days in filtered and unfiltered samples. Significant differences were related to filtration: both turbidity grade and microbial contamination; no differences for the legal parameters were found. Two, contrasting, results were obtained with respect to oil quality: (i) the fusty defect, appearing in less than five days in unfiltered oils, leading to the downgrade of the oil\u2019s commercial category, and (ii) filtration removing some lipoxygenase volatile compounds. Consequently, a fruity attribute was more pronounced in unfiltered samples until day five of storage; it seems that, from this point, the fusty defect masked a fruity attribute. Hence, filtering within a few days strongly reduced the risk of degraded oil quality compared to a delayed filtration

    Incidence of complications in bronchoscopy. Multicentre prospective study of 20,986 bronchoscopies.

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    Aim. To evaluate the frequency of complications in bronchoscopy from data compiled between 1/2/2002 to 1/2/2003. Materials and methods. Nineteen Italian centres of thoracic endoscopy participated in the study, for a total of 20,986 bronchoscopies (FBS), including 10,658 explorative bronchoscopies (EB) (50.79%), 5,520 bronchial biopsies (BB) (26.30%), 1,660 transbronchial biopsies (TBB) (7.91%), 1,127 broncho-alveolar lavages (BAL) (5.37%), 930 transbronchial needle-aspirates (TBNA) (4.43%), 1.091 therapeutic bronchoscopies (TB), comprising NDYAG Laser, argon-plasma, electrocautery knife, stent insertion (5.20%). 82.4% of the procedures involved the use of a flexible bronchoscope, 16.3% were carried out using a rigid bronchoscope and 1.3% using the mixed technique. Results. The total number of complications recorded was 227 (1.08% of the cases examined), including 20 (0.09%) during local anesthesia and pre-medication, 195 (0.92%) during the endoscopic procedures and 12 (0.05%) in the two hours following FBS. The total number of deaths was 4 (0.02%), due to cardiac arrest, pulmonary edema, delayed respiratory failure and shock in pre-medication, respectively. 68.28% of the complications were treated medically, 25.99% by means of endoscopy and 5.72% with surgery. The healing percentage was 98.2%. Conclusions. This study has shown that bronchoscopy is a safe method with low incidence of mortality and complications. The preparation, experience and continuous training of the operators of the medical and nursing team seem to play a fundamental role in reducing the incidence of complications at least in certain procedures such as BB and TBB

    Interventions addressing the adolescent HIV continuum of care in South Africa: a systematic review and modified Delphi analysis

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    INTRODUCTION: Compared with adults, adolescents in South Africa have larger gaps at each step of the HIV continuum of care resulting in low levels of viral suppression. METHODS: We conducted a systematic review and modified Delphi analysis of interventions addressing the HIV continuum of care for adolescents in South Africa. We searched PubMed, Science Direct, and Google Scholar and online conference proceedings from the International AIDS Society, the International AIDS Conference, and the Conference on Retrovirology and Opportunistic Infections from 1 January 2010 to 30 September 2020. We then conducted a modified Delphi analysis with 29 researchers involved in the National Institutes of Health's Fogarty International-supported Adolescent HIV Implementation Science Alliance-South Africa to evaluate interventions for efficacy, feasibility and potential for scale-up. RESULTS: We identified nine initial published articles containing interventions addressing the adolescent HIV continuum of care in South Africa, including five interventions focused on HIV diagnosis, two on antiretroviral therapy adherence and two on retention in care. No studies addressed linkage to care or transition from paediatric to adult care. Two studies discussed intervention costs. In-home and HIV self-testing, community-based adherence support, and provision of adolescent-friendly services were the most impactful and scalable interventions addressing the adolescent HIV continuum of care. CONCLUSION: Future interventions should work comprehensively across the adolescent HIV continuum of care and be tailored to the specific needs of adolescents

    Sensory and chemical profile of a phenolic extract from olive mill waste waters in plant-base food with varied macro-composition

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    Phenols from olive mill waste water (OMWW) represent valuable functional ingredients. The negative impact on sensory quality limits their use in functional food formulations. Chemical interactions phenols/biopolymers and their consequences on bioactivity in plant-base foods have been widely investigated, but no studies to date have explored the variation of bitterness, astringency and pungency induced by OMWW phenols as a function of the food composition. The aim of the paper was to profile the sensory and chemical properties of phenols from OMWW in plant-base foods varied in their macro-composition. Four phenol concentrations were selected (0.44, 1.00, 2.25, 5.06 g/kg) to induce significant variations of bitterness, sourness, astringency and pungency in three plant-base food: proteins/neutral pH \u2013 bean pur\ue9e (BP), starch/neutral pH \u2013 potato pur\ue9e (PP), fiber/low pH \u2013 tomato juice (TJ). The macro-composition affected the amount of the phenols recovered from functionalized food. The highest recovery was from TJ and the lowest from BP. Two groups of 29 and 27 subjects, trained to general Labelled Magnitude Scale and target sensations, participated in the evaluation of psychophysical curves of OMWW phenols and of functionalized plant-base foods, respectively. Target sensations were affected by the food macro-composition. Bitterness increased with phenol concentration in all foods. Astringency and sourness slightly increased with concentration, reaching the weak-moderate intensity at the highest phenol concentration in PP and TJ only. Pungency was suppressed in BP and perceived at weak-moderate intensity in PP and TJ sample at the highest phenol concentration. Proteins/neutral pH plant-food (BP) resulted more appropriate to counteract the impact of added phenol on negative sensory properties thus allowing to optimize the balance between health and sensory properties

    Sensory and chemical profile of a phenolic extract from olive mill waste waters in plant-base food with varied macro-composition

    Get PDF
    Phenols from olive mill waste water (OMWW) represent valuable functional ingredients. The negative impact on sensory quality limits their use in functional food formulations. Chemical interactions phenols/biopolymers and their consequences on bioactivity in plant-base foods have been widely investigated, but no studies to date have explored the variation of bitterness, astringency and pungency induced by OMWW phenols as a function of the food composition. The aim of the paper was to profile the sensory and chemical properties of phenols from OMWW in plant-base foods varied in their macro-composition. Four phenol concentrations were selected (0.44, 1.00, 2.25, 5.06 g/kg) to induce significant variations of bitterness, sourness, astringency and pungency in three plant-base food: proteins/neutral pH \u2013 bean pur\ue9e (BP), starch/neutral pH \u2013 potato pur\ue9e (PP), fiber/low pH \u2013 tomato juice (TJ). The macro-composition affected the amount of the phenols recovered from functionalized food. The highest recovery was from TJ and the lowest from BP. Two groups of 29 and 27 subjects, trained to general Labelled Magnitude Scale and target sensations, participated in the evaluation of psychophysical curves of OMWW phenols and of functionalized plant-base foods, respectively. Target sensations were affected by the food macro-composition. Bitterness increased with phenol concentration in all foods. Astringency and sourness slightly increased with concentration, reaching the weak-moderate intensity at the highest phenol concentration in PP and TJ only. Pungency was suppressed in BP and perceived at weak-moderate intensity in PP and TJ sample at the highest phenol concentration. Proteins/neutral pH plant-food (BP) resulted more appropriate to counteract the impact of added phenol on negative sensory properties thus allowing to optimize the balance between health and sensory properties
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