854 research outputs found
Risk of deânovo formation of chlormequat and mepiquat in industrial cocoa products assessed by ion chromatography coupled with highâresolution mass spectrometry
Mepiquat (MQ) and chlormequat (CQ) are two main food contaminants that could be naturally present in various animal and plant foods due to heat treatments. Cocoa and its derivative products seem to be a matrix inclined, for both chemical characteristics and production technologies, to the formation of MQ and CQ. In this study, exploiting the selectivity and sensitivity of IC-HRMS, a new reliable analytical method was developed and validated for MQ and CQ quantification. The LOD of the method was set at 1.9 lg kg 1 for both CQ and MQ, and the linearity was defined from 6.25 to 625 lg kg 1 . Average recoveries, at 2 lg L 1 , were 96.5% and 97.5% for CQ and MQ, respectively, while precision as repeatability (RSDr%) was 2.3% and 5.1% respectively. Subsequently, a laboratory-scale experiment was conducted to assess, for the first time, the actual risk of MQ and CQ formation, confirming in cocoa products the presence of MQ at detectable concentration after 55 min at 180 °C, approximately 8 lg kg 1 for cocoa and 7 lg kg 1 for chips. However, the investigation of a wide variety of commercial cocoa and nuts products has fortunately ruled out the presence of such contaminants at detectable concentration
Empirical observations and numerical modelling of tides, channel morphology, and vegetative effects on accretion in a restored tidal marsh
Tidal marshes form at the confluence between estuarine and marine environments where tidal movement regulates their developmental processes. Here, we investigate how the interplay between tides, channel morphology, and vegetation affect sediment dynamics in a low energy tidal marsh at the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island. Poplar Island is an active restoration site where fineâgrained material dredged from navigation channels in the upper Chesapeake Bay are being used to restore remote tidal marsh habitat toward the middle bay (Maryland, USA). Tidal currents were measured over multiple tidal cycles in the inlets and tidal creeks of one marsh at Poplar Island, Cell 1B, using Acoustic Doppler Current Profilers (ADCP) to estimate water fluxes throughout the marsh complex. Sediment fluxes were estimated using acoustic backscatter recorded by ADCPs and validated against total suspended solid measurements taken on site. A highâresolution geomorphic survey was conducted to capture channel cross sections and tidal marsh morphology. We integrated simple numerical models built in Delft3d with empirical observations to identify which ecoâgeomorphological factors influence sediment distribution in various channel configurations with differing vegetative characteristics. Channel morphology influences floodâebb dominance in marshes, where deep, narrow channels promote high tidal velocities and incision, increasing sediment suspension and reducing resilience in marshes at Poplar Island. Our numerical models suggest that accurately modelling plant phenology is vital for estimating sediment accretion rates. Inâsitu observations indicate that Poplar Island marshes are experiencing erosion typical for many Chesapeake Bay islands. Peak periods of sediment suspension frequently coincide with the largest outflows of water during ebb tides resulting in large sediment deficits. Ebb dominance (net sediment export) in tidal marshes is likely amplified by seaâlevel rise and may lower marsh resilience. We couple field observations with numerical models to understand how tidal marsh morphodynamics contribute to marsh resilience
Modulation of wine sensory profile by lactic bacterial activity in a global warming scenario by different malolactic fermentation strategies
Aim. Incoming global warming imposing strategies to adapt wine chemical profile at an unknown scenario. In this sense malolactic fermentation (MLF), the biological deacidification of wines, must become a conscious choice to optimize the content in organic acids and the sensory profile of the wine. The authors present different works to understand how modulate the oenological activity of strains of Oenococcus oeni. The effect of different strategies of bacterial inoculum and correction of acidity were considered. Method. Simultaneous fermentation is an alternative strategy for managing MLF, which involves the inoculation of lactic bacteria into the grape must, instead into the wine at the end of alcoholic fermentation as traditionally practiced in winemaking. This approach has been tested in southern red wines with a high ethanol potential, withe aromatic wines, and sparkling-base wines. Furthermore, on a population of strains of O. oeni was verified the effect of the correction of grape must/wine acidity by different organic acids, in terms of MLF kinetics, cell viability and diacetyl production. Results. In the last years the focus of the selection of bacterial strains for malolactic fermentation was re-oriented from the mere ability to accomplish malic acid degradation, to the adaptability at different winemaking protocols. In this sense, simultaneous inoculum of bacteria and yeast in grape must seems to achieve different goals. In southern, high ethanol and low acidity wines bacteria results more active respect to tests performed by traditional post-alcoholic inoculum, accomplishing MLF without spoilage effects, such as volatile acidity increase. In the case of tests performed in winemaking if aromatic or sparkling base wines the simultaneous inoculum results in a higher varietal character. Tartaric, malic, and citric acid were tested to correct the low acidity of grape must/wine before MLF. Malic acid over the 2.5 g/L affected evolution of MLF, while citric acid stimulates bacterial activity and diacetyl production. The addition of tartaric acid results counterproductive at the higher value. Bacterial activity in grape must is more efficient than in wine in terms of rate and completeness of MLF. Conclusion. The acidic profile of wine is one of the key aspects in a global warming scenario, for longevity and organoleptic quality. This work offers useful information to modulate the activity of lactic acid bacteri
Confirming the function of a Final Bronze Age wine processing site in the Nuraghe Genna Maria in Villanovaforru (South Sardinia)
The stone artefact in the hut Îł of the NuragheGenna Maria, object of this study, is part of a compound still unpublished today and dated to the Nuragic period. It was found during a 1991 excavation, revealing a situation unchanged since the collapse occurred between the 10th and 9th century B.C., thus preserving the situation at the time of the collapse to this day.
The presence of tartaric acid - the marker considered to determinate the presence of wines or products deriving from grapes - has been determined using HPLC-DAD and UHPLC-HQOMS. So the findings under examination, together with the overall evaluation of the archaeological aspects examined, suggests to positively consider the stone artifact as a "laccus" (the latin word for wine presses, still used in the Sardinian language today ) for grape crushing. The internal slope of the floor of the "laccus" allowed the extraction of juice with rapid separation of juice from berry skins.
The presence in Sardinia of a large number of "stone wine presses" ("palmenti" in Italian) such as that of the Nuraghe Genna Maria studied in this article, brings a contribution to their dating and confirm the existence of an oenological industry on the island in the Archaic period (9th-10th century B.C.)
Buried Alive or Washed Away The Challenging Life of Mangroves in the Mekong Delta
Mangroves colonize tropical shorelines, protecting coastal communities and providing valuable ecosystem services. Mangroves associated with deltas cope with a very dynamic environment characterized by strong gradients in salinity, deposition triggered by sediment inputs, and erosion caused by waves and currents. Mangroves are adapted to this ever-changing landscape, with different species colonizing different elevations in response to inundation frequency. A series of feedbacks between hydrodynamics, sediment transport, and mangroves was observed in a fringe forest of the Mekong Delta, Vietnam. Sonneratia spp. rapidly encroach upon sandy areas because the stable substrate favors seedling establishment. In contrast, fewer seedlings are present in muddy locations where currents and waves frequently rework the bottom. Along muddy shorelines that are eroding, turbulence increases local scour near roots and trunks, undercutting the trees. Enhanced sediment accumulation due to delta progradation can smother the mangrove roots and lead to forest dieback. We find clear evidence that mangroves affect both hydrodynamics and sediment transport, thus engineering the landscape and enhancing sediment trapping and delta progradation. Sonneratia spp. are replaced by Aegiceras corniculatum, Avicennia marina, and Nypa fruticans when the seabed becomes high enough, indicating that ecological succession is present in a fast prograding deltaic environment. Thus, it is imperative to determine the small-scale feedbacks between mangroves, hydrodynamics, and sediment transport in order to build quantitative ecogeomorphic models of deltaic sedimentation that can be used to explain the distribution of mangrove species, the forest structure, and large-scale dynamics in a tropical deltaic setting
Omineca Miner, January, 02, 1915
BACKGROUND AND AIMS: Immature platelet fraction (IPF) represents the quote of younger and larger sized circulating platelets, a potential marker of platelet reactivity and major cardiovascular events. We aimed to assess the relationship between IPF levels and the prevalence and extent of coronary artery disease (CAD) in patients undergoing coronary angiography. METHODS: A cohort of consecutive patients undergoing coronary angiography in a single centre were included. Significant CAD was defined as at least 1 vessel stenosis >50%, while severe CAD was defined as left main and/or three-vessel disease. IPF levels were measured at admission by routine blood cells count (A Sysmex XE-2100). RESULTS: We included 1789 patients, divided according to quartiles values of IPF. IPF levels were directly related to active smoke (p = 0.02), and non-acute coronary syndrome as indication to angiography (p < 0.001), higher levels of haemoglobin and uric acid (p < 0.001, respectively) and lower platelet count (p = 0.003). Angiographic features did not significantly differ according to quartiles values of IPF, but for a lower degree of TIMI flow in patients with a higher percentage of reticulated platelets (p = 0.01) and a higher rate of lesions involving bifurcations (p = 0.05). IPF levels did not affect the prevalence of CAD (77% vs. 82.2% vs. 79.1% vs. 75.6%, p = 0.34, adjusted OR [95% CI] = 0.93 [0.82-1.05], p = 0.22), nor of severe left main/three-vessel CAD (28.5% vs. 34.4% vs. 32.2% vs. 33.1%, p = 0.27; adjusted OR [95% CI] = 0.99 [0.90-1.1], p = 0.88). CONCLUSIONS: The present study shows that among patients undergoing coronary angiography, the immature platelet fraction (IPF) is not associated with the prevalence and extent of coronary artery disease, and, therefore, should not be overlooked as a marker of coronary atherosclerosis
Dynamics of long-range order in an exciton-polariton condensate
We report on time resolved measurements of the first order spatial coherence
in an exciton polariton Bose-Einstein condensate. Long range spatial coherence
is found to set in right at the onset of stimulated scattering, on a picosecond
time scale. The coherence reaches its maximum value after the population and
decays slower, staying up to a few hundreds of picoseconds. This behavior can
be qualitatively reproduced, using a stochastic classical field model
describing interaction between the polariton condensate and the exciton
reservoir within a disordered potential.Comment: 7 pages, 4 figure
Application of NMR spectroscopy for tracing improved nutritional values in caciotta-like cheeses
InfluĂȘncia do herbicida glifosato sobre o desenvolvimento de videiras.
o herbicida glifosato possibilita um controle eficaz de plantas daninhas em muitos cultivos, inclusive em vinhedos. Entretanto, se for aplicado de forma inadequada, pode prejudicar as culturas de interesse econĂŽmico. O objetivo do trabalho foi determinar a influĂȘncia do glifosato sobre o desenvolvimento de videirasResumo
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