15 research outputs found

    Levels of Alzheimer's disease blood biomarkers are altered after food intake—A pilot intervention study in healthy adults

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    INTRODUCTION: Blood biomarkers accurately identify Alzheimer's disease (AD) pathophysiology and axonal injury. We investigated the influence of food intake on AD-related biomarkers in cognitively healthy, obese adults at high metabolic risk. METHODS: One-hundred eleven participants underwent repeated blood sampling during 3 h after a standardized meal (postprandial group, PG). For comparison, blood was sampled from a fasting subgroup over 3 h (fasting group, FG). Plasma neurofilament light (NfL), glial fibrillary acidic protein (GFAP), amyloid-beta (Aβ) 42/40, phosphorylated tau (p-tau) 181 and 231, and total-tau were measured via single molecule array assays. RESULTS: Significant differences were found for NfL, GFAP, Aβ42/40, p-tau181, and p-tau231 between FG and PG. The greatest change to baseline occurred for GFAP and p-tau181 (120 min postprandially, p < 0.0001). CONCLUSION: Our data suggest that AD-related biomarkers are altered by food intake. Further studies are needed to verify whether blood biomarker sampling should be performed in the fasting state. Highlights: Acute food intake alters plasma biomarkers of Alzheimer's disease in obese, otherwise healthy adults. We also found dynamic fluctuations in plasma biomarkers concentration in the fasting state suggesting physiological diurnal variations. Further investigations are highly needed to verify if biomarker measurements should be performed in the fasting state and at a standardized time of day to improve the diagnostic accuracy

    In Silico and Biochemical Analysis of Physcomitrella patens Photosynthetic Antenna: Identification of Subunits which Evolved upon Land Adaptation

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    Background. In eukaryotes the photosynthetic antenna system is composed of subunits encoded by the light harvesting complex (Lhc) multigene family. These proteins play a key role in photosynthesis and are involved in both light harvesting and photoprotection. The moss Physcomitrella patens is a member of a lineage that diverged from seed plants early after land colonization and therefore by studying this organism, we may gain insight into adaptations to the aerial environment. Principal Findings. In this study, we characterized the antenna protein multigene family in Physcomitrella patens, by sequence analysis as well as biochemical and functional investigations. Sequence identification and analysis showed that some antenna polypeptides, such as Lhcb3 and Lhcb6, are present only in land organisms, suggesting they play a role in adaptation to the sub-aerial environment. Our functional analysis which showed that photo-protective mechanisms in Physcomitrella patens are very similar to those in seed plants fits with this hypothesis. In particular, Physcomitrella patens also activates Non Photochemical Quenching upon illumination, consistent with the detection of an ortholog of the PsbS protein. As a further adaptation to terrestrial conditions, the content of Photosystem I low energy absorbing chlorophylls also increased, as demonstrated by differences in Lhca3 and Lhca4 polypeptide sequences, in vitro reconstitution experiments and low temperature fluorescence spectra. Conclusions. This study highlights the role of Lhc family members in environmental adaptation and allowed proteins associated with mechanisms of stress resistance to be identified within this large family

    Efeito da luminosidade e da adição de nitrogênio no crescimento de plantas de Ilex paraguariensis St. Hil. Effect of light and nitrogen on the growth of Ilex paraguariensis St. Hil.

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    Neste trabalho, buscou-se identificar o efeito de diferentes níveis de luminosidade e da adição de adubo nitrogenado sobre o crescimento das plantas de erva-mate, no primeiro ano de crescimento. No experimento, usou-se o delineamento de blocos ao acaso, com três repetições, em quatro tratamentos e dois subtratamentos, tendo 16 parcelas por bloco. O esquema adotado foi o fatorial, tendo como variável constante a luminosidade em quatro intensidades (100, 70, 50 e 30%) e o nitrogênio como variável interveniente sobre as parcelas. As leituras foram efetuadas a cada 45 dias, em três horários diários por três dias consecutivos, durante um ano. Verificou-se que a condição mais adequada para o crescimento das plantas foi com luminosidades de 50 e 30%. A adição de nitrogênio não mostrou influência relevante no crescimento da erva-mate, especialmente nas luminosidades de 100 e 70%, enquanto o aumento da luminosidade tendeu a reduzir o crescimento das plantas. Contudo, as plantas adubadas (1N) tiveram maior rebrota que aquelas não-adubadas. A adição de nitrogênio mineral, em dosagens elevadas, foi danosa para as plantas de erva-mate, acarretando a mortalidade nas parcelas com tratamentos de maior luminosidade.<br>This paper aimed to evaluate the effect of different levels of luminosity and nitrogen addition on the height of mate plants in the first year of growth. The experiment was arranged in randomized blocks, with three replicates, in four treatments and two sub-treatments, in a total of 16 plots per block, in a factorial design, with the luminosity in four different intensities (100%, 70%, 50% and 30%) and the nitrogen application as the intervening variable on the plots. Data were collected every 45 days, in three daily schedules during three consecutive days, over one year. It was found that the best conditions to plant growth were 50% and 30% luminosity. The nitrogen addition have no relevant influence in plant growth, particularly at 100% and 70% luminosity, while the increase in luminosity contributed to the reduction in plant growth. However, the fertilized plants (1N) increased regrowth. Nitrogen addition at high doses damaged the mate plants and caused death of mate plants in the plots with higher luminosity

    An integrated pan-tropical biomass map using multiple reference datasets (PAN-TROPICAL FUSED BIOMASS MAP)

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    Abstract We combined two existing datasets of vegetation aboveground biomass (AGB) (Saatchi et al., 2011; Baccini et al., 2012) into a pan-tropical AGB map at 1-km resolution using an independent reference dataset of field observations and locally-calibrated high-resolution biomass maps, harmonized and upscaled to 14,477 1-km AGB estimates. Our data fusion approach uses bias removal and weighted linear averaging that incorporates and spatializes Accepted Article This article is protected by copyright. All rights reserved. existing regional biomass maps as input maps and additional, country-specific reference datasets
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