4,451 research outputs found
Consumer Labels can Convey Polyphenolic Content: Implications for Public Health
Polyphenolics are a large group of related substances. Many of these, in
fact much of that found in food, is composed of processing-derived substances
too complex for complete identification. Recent studies have suggested likely
benefits for diets high in polyphenols, particular in reducing heart disease mortality,
but other benefits have also been suggested. A consumer label based on
the major polyphenolic classes is both manageable and fairly informative as
most foods do not contain all possible classes. Differences between class
member can be significant, but data on individual substances is impractical
and no data is certainly less informative. Equivalency scales may be useful but
may skew content of many foods towards the high-equivalency substances, even
while the full beneficial effects of each individual substance is poorly described
Analysis of red wine phenolics: Comparison of HPLC and spectrophotometric methods
A recently developed ion-pair normal phase HPLC method which allows a precise chromatographic evaluation of the whole class of high-molecular-mass phenolics of wine was used in order to check the performance of spectrophotometric methods. Thirty-two monovarietal red wines (vintages 1993 and 1998) were analysed for total high-molecular-mass phenolics, proanthocyanidins with 2-4 units, and proanthocyanidins formed by 5 or more units, by means of the normal phase HPLC method. In addition the following spectrophotometric assays were performed: total phenols by Folin-Ciocalteu, Bate-Smith transformation of proanthocyanidins into cyanidin and catechins and proanthocyanidins reactive to vanillin.
Cocoa and health: a decade of research
It has been over 10 years since the first mention in a medical journal about cocoa and chocolate as potential sources of antioxidants for health. During this time, cocoa has been found to improve antioxidant status, reduce inflammation and correlate with reduced heart disease risk; with these results, and its popularity, it has received wide coverage in the press. However, after 10 years of research, what is known about the potential health benefits of cocoa and what are the important next steps in understanding this decadent source of antioxidants
Antioxidants in white wine (cv. Riesling): I. Comparison of different testing methods for antioxidant activity
This paper provides a study on different testing methods for antioxidant activity. Four commonly used methods (LDL oxidation, TAS measurement, beta-carotene bleaching as well as a rapid screening test published by PRYOR et al. 1993) are compared on the basis of a set of model compounds. The differing results concerning the ranking order of the tested substances are discussed. Furthermore three methods which showed appropriate results were used in order to determine the antioxidant activity of Riesling wine fractions
Anthocyanins inhibit tumor necrosis alpha-induced loss of Caco-2 cell barrier integrity
An increased permeability of the intestinal barrier is proposed as a major event in the pathophysiology of conditions characterized by chronic gut inflammation. This study investigated the capacity of pure anthocyanins (AC), and berry and rice extracts containing different types and amounts of AC, to inhibit tumor necrosis alpha (TNFα)-induced permeabilization of Caco-2 cell monolayers. Caco-2 cells differentiated into intestinal epithelial cell monolayers were incubated in the absence/presence of TNFα, with or without the addition of AC or AC-rich plant extracts (ACRE). AC and ACRE inhibited TNFα-induced loss of monolayer permeability as assessed by changes in transepithelial electrical resistance (TEER) and paracellular transport of FITC-dextran. In the range of concentrations tested (0.25–1 μM), O-glucosides of cyanidin, and delphinidin, but not those of malvidin, peonidin and petunidin protected the monolayer from TNFα-induced decrease of TEER and increase of FITC-dextran permeability. Cyanidin and delphinidin acted by mitigating TNFα-triggered activation of transcription factor NF-κB, and downstream phosphorylation of myosin light chain (MLC). The protective actions of the ACRE on TNFα-induced TEER increase was positively correlated with the sum of cyanidins and delphinidins (r2 = 0.83) content in the ACRE. However, no correlation was observed between TEER and ACRE total AC, malvidin, or peonidin content. Results support a particular capacity of cyanidins and delphinidins in the protection of the intestinal barrier against inflammation-induced permeabilization, in part through the inhibition of the NF-κB pathway.Fil: Cremonini, Eleonora. University of California at Davis; Estados UnidosFil: Mastaloudis, Angela. Nu Skin Enterprises; Estados UnidosFil: Hester, Shelly N.. Nu Skin Enterprises; Estados UnidosFil: Verstraeten, Sandra Viviana. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Departamento de QuÃmica Biológica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas; ArgentinaFil: Anderson, Maureen. University of California at Davis; Estados UnidosFil: Wood, Steven M.. Nu Skin Enterprises; Estados UnidosFil: Waterhouse, Andrew L.. University of California at Davis; Estados UnidosFil: Fraga, César Guillermo. University of California at Davis; Estados Unidos. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de BioquÃmica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de BioquÃmica y Medicina Molecular; ArgentinaFil: Oteiza, Patricia Isabel. University of California at Davis; Estados Unidos. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Terrestrial lichen response to partial cutting in lodgepole pine forests on caribou winter range in west-central British Columbia
In west-central British Columbia, terrestrial lichens located in older, lodgepole pine (Pinus contorta) forests are important winter forage for woodland caribou (Rangifer tarandus caribou). Clearcut harvesting effectively removes winter forage habitat for decades, so management approaches based on partial cutting were designed to maintain continuous lichen-bearing habitat for caribou. This study tested a group selection system, based on removal of 33% of the forest every 80 years in small openings (15 m diameter), and two irregular shelterwood treatments (whole-tree and stem-only harvesting methods) where 50% of the stand area is cut every 70 years in 20 to 30 m diameter openings. The abundance of common terrestrial lichens among the partial cutting and no-harvest treatments was compared across five replicate blocks, pre-harvest (1995) and post-harvest (1998, 2000 and 2004). The initial loss of preferred forage lichens (Cladonia, Cladina, Cetraria and Stereocaulon) was similar among harvesting treatments, but there was greater reduction in these lichens in the openings than in the residual forest. After eight years, forage lichens in the group selection treatment recovered to pre-harvest amounts, while lichen in the shelterwood treatments steadily increased from 49 to 57% in 1998 to about 70% of pre-harvest amounts in 2004. Although not part of the randomized block design, there was substantially less lichen in three adjacent clearcut blocks than in the partial cuts. Regression analysis pre- and post-harvest indicated that increased cover of trees, shrubs, herbs, woody debris and logging slash corresponded with decreased forage lichen abundance. In the short-term, forestry activities that minimize inputs of woody debris, control herb and shrub development, and moderate the changes in light and temperatures associated with canopy removal will lessen the impact on lichen. Implementation of stand level prescriptions is only one aspect of caribou habitat management. A comprehensive approach should consider all factors and their interactions to maintain a viable population of woodland caribou in west-central British Columbia
Gauss Sums and Quantum Mechanics
By adapting Feynman's sum over paths method to a quantum mechanical system
whose phase space is a torus, a new proof of the Landsberg-Schaar identity for
quadratic Gauss sums is given. In contrast to existing non-elementary proofs,
which use infinite sums and a limiting process or contour integration, only
finite sums are involved. The toroidal nature of the classical phase space
leads to discrete position and momentum, and hence discrete time. The
corresponding `path integrals' are finite sums whose normalisations are derived
and which are shown to intertwine cyclicity and discreteness to give a finite
version of Kelvin's method of images.Comment: 14 pages, LaTe
Physiological Response and Tissue Damage Following Different Depths of Impact in a Rodent Model of Mild Traumatic Brain Injury
Mild traumatic brain injury (mTBI) is a serious public health concern that can result in significant neurological and behavioral deficit. mTBI results from impact to the head and can be repetitive in nature, especially in sports and domestic violence cases. Our laboratory studies the effects of repetitive mTBI on risky choice behavior in rodents using a closed-head controlled cortical impact (CH-CCI) model of injury and a well-established probabilistic discounting task that assesses risk-based decision-making behavior. We have recently found that females, but not males, display transient increases in risky choice behavior following three CH-CI’s delivered at 5.5m/s velocity and 2.5 mm impact depth. These findings suggest that our injury parameters may produce marginally threshold influences on behavioral outcomes that do not allow observation of the extent of repetitive mTBI-induced effects and have prompted us to explore expansion of our model to include greater depths of injury. In the present work we subjected rats to a series of three fixed velocity impacts at depths of 2.5mm, 3.0mm, or 3.5mm. The goal was to compare physical manifestations of injury in male and female rats following different depths of injury. The survival rate, righting reflex time, skull injury observations, animal weights, and histological markers of tissue damage were evaluated post-injury. Our hypothesis was that these indices of injury would be more prominent as injury depth increased
Policy options to streamline the carbon market for agricultural nitrous oxide emissions
The majority of emissions of nitrous oxide – a potent greenhouse gas (GHG) – are from agricultural sources, particularly nitrogen fertilizer applications. A growing focus on these emission sources has led to the development in the United States of GHG offset protocols that could enable payment to farmers for reducing fertilizer use or implementing other nitrogen management strategies. Despite the development of several protocols, the current regional scope is narrow, adoption by farmers is low, and policy implementation of protocols has a significant time lag. Here we utilize existing research and policy structures to propose an ‘umbrella’ approach for nitrogen management GHG emissions protocols that has the potential to streamline the policy implementation and acceptance of such protocols. We suggest that the umbrella protocol could set forth standard definitions common across multiple protocol options, and then modules could be further developed as scientific evidence advances. Modules could be developed for specific crops, regions, and practices. We identify a policy process that could facilitate this development in concert with emerging scientific research and conclude by acknowledging potential benefits and limitations of the approach. Key policy insights Agricultural greenhouse gas market options are growing, but are still underutilized Streamlining protocol development through an umbrella process could enable quicker development of protocols across new crops, regions, and practices Effective protocol development must not compromise best available science and should follow a rigorous pathway to ensure appropriate implementation
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