Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 11 )

2019 ( 714 )

2018 ( 849 )

2017 ( 787 )

Custom range...

Search Results: 1 - 10 of 475319 matches for " Mark A. Berhow "
All listed articles are free for downloading (OA Articles)
Page 1 /475319
Display every page Item
Purification of a Sinapine-Glucoraphanin Salt from Broccoli Seeds  [PDF]
Mark A. Berhow, Karl Vermillion, Gulab N. Jham, Brent Tisserat, Steven F. Vaughn
American Journal of Plant Sciences (AJPS) , 2010, DOI: 10.4236/ajps.2010.12015
Abstract: A sinapine (sinapoylcholine)-glucoraphanin salt has been isolated from broccoli seeds and characterized by NMR and mass spectrometry. This salt extraction method can be used to purify glucoraphanin free from contamination by glucoiberin.
Differential Anticancer Effect of an Apple Extract (Applephenon®), Polyphenols and Isoflavones on Normal Human Keratinocytes and Epidermoid Cancer Cells  [PDF]
John J. Wille, Mark A. Berhow, Jong Y. Park
Journal of Cancer Therapy (JCT) , 2019, DOI: 10.4236/jct.2019.106040
Abstract: Applephenon®, a purified extract prepared from green apples, was examined for its cytotoxicity and inhibitory effects on the proliferation of cultures of normal human keratinocytes and several epidermoid cancer cell lines. Our HPLC studies demonstrated a high content of phenolic compounds (>65%), including catechin, epicatechin, caffeic acid and phloretin as well as polyphenols such as proanthocyanidins. Applephenon® demonstrated a greater cytotoxic effect against HeLa, A431 cancer cell lines and HaCaT, an immortalized keratinocyte cell line than serum-free cultures of proliferating normal human keratinocytes (NHK). Proliferation of NHK was inhibited at concentrations above 0.0013% while concentrations above 0.005% were cytotoxic. By contrast, Applephenon® solutions above 0.00025% killed each of the cancer cell lines. Treated cells displayed increased intercellular separation and evidence of keratinizing stratification. We also tested the effect of epicatechin, and two isoflavonoids, genistein and daidzein, on cancer cell lines. Hela cells were more sensitive to epicatechin and genistein inhibition of cell growth and cytotoxicity than were NHK. Daidzein at these concentrations had little effect on cancer cells. These results indicate that Applephenon® and some of its phenolic components have selective anticancer activity.
Influence of Jet-Cooking Corn Bran on Its Antioxidant Activities, Phenolic Contents and Viscoelastic Properties  [PDF]
George E. Inglett, Diejun Chen, Mark Berhow
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.26075
Abstract: Corn bran was subjected to high-shear and jet-cooking with or without alkaline treatment. The highest antioxidant activity was found in the soluble solids from jet-cooked corn bran without alkaline treatment. Jet-cooking under alkaline conditions resulted in a soluble fraction having the highest phenolic content but without increasing antioxidant activity. Phenolic contents of soluble solids were significantly higher than the insoluble solids. A colorimetric method using spectrophotometer was suitable to determine total phenolic content, whereas LC-ESI-MS technology was used for identifying important individual phenolic acids, namely caffeic, coumaric and ferulic acid. The insoluble solids from alkaline treatment had the highest water holding capacity and interesting viscoelastic properties. These results suggested that jet-cooking corn bran may be a useful processing procedure for creating phytochemical and functional products.
The use of fatty acid profile as a potential marker for Brazilian coffee (Coffea arabica L.) for corn adulteration
Jham, Gulab N.;Berhow, Mark A.;Manthey, Linda K.;Palmquist, Deborah A.;Vaughn, Steven F.;
Journal of the Brazilian Chemical Society , 2008, DOI: 10.1590/S0103-50532008000800004
Abstract: fatty acid methyl ester (fame) composition of the coffee (coffea arabica l.) varieties catuai, catucaí, bourbom, mundo novo, rubí and topázio known to produce beverage of intermediate, excellent, excellent, intermediate, intermediate and poor quality, respectively, was determined for the first time. average area % of the fames of the six varieties was: palmitic (38.2), stearic (8.3), oleic (8.6), linoleic (38.5), linolenic (1.6) and arachidic (3.6) acids, respectively. the method was very quick with complete characterization (>99%) of the samples studied being possible in less than 6 min. while these values may provide insights for evaluating the coffee quality, no significant effect (p < 0.05) of coffee variety was found on area % of the fames. in addition, fames of six corn samples, six commercial coffee brands and one commercial coffee sample intentionally contaminated with three levels of corn were compared. although the linoleic/stearic ratio was significantly different in coffee and corn fames, this probe could not be used a marker to detect corn adulteration in commercial coffees.
Chlorogenic acid levels in leaves of coffee plants supplied with silicon and infected by Hemileia vastatrix
Rodrigues, Fabrício A.;Carré-Missio, Vivian;Jham, Gulab N.;Berhow, Mark;Schurt, Daniel A.;
Tropical Plant Pathology , 2011, DOI: 10.1590/S1982-56762011000600010
Abstract: rust, caused by hemileia vastatrix, is the main disease that decreases coffee production in brazil. new and enhanced methods to reduce rust intensity that can be integrated with modern genetic and chemical approaches need to be investigated. considering that many plant species supplied with silicon (si) show increased resistance to several pathogens, this study examined the possible effect of this element in increasing chlorogenic acid (ca) concentrations in coffee leaves and, consequently, increasing the level of resistance to rust. plants (cv. "catuaí vermelho iac 44") were inoculated with h. vastatrix after growing for 35 days in a hydroponic culture amended with 0 (-si) or 2 (+si) mm si. concentration of si in leaf tissues was of 0.36 and 0.42 dag/kg for -si and +si treatments, respectively, but without a statistically significant difference. the area under rust progress curve was 154.5 and 119.4 for -si and +si treatments, respectively, but without significant statistical difference. for non-inoculated plants, the concentrations of total ca and caffeoyl-quinic acid (cqa)compounds (dicqa) were similar between -si and +si treatments. even though there was an increase of 236.4 and 257.1%, respectively, for total ca and dicqa for +si when compared to -si treatment at 30 days after inoculation with h. vastatrix, reduction on rust severity was not obtained once the fungus had already colonized the leaf tissues. therefore, regardless of the increase in the concentrations of chlorogenic acid on leaves, coffee resistance to h. vastatrix infection was not potentialized by si.
Investment in Seed Physical Defence Is Associated with Species' Light Requirement for Regeneration and Seed Persistence: Evidence from Macaranga Species in Borneo
Pimonrat Tiansawat, Adam S. Davis, Mark A. Berhow, Paul-Camilo Zalamea, James W. Dalling
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0099691
Abstract: The seed stage is often critical in determining the regeneration success of plants. Seeds must survive an array of seed predators and pathogens and germinate under conditions favourable for seedling establishment. To maximise recruitment success plants protect seeds using a diverse set of chemical and physical defences. However, the relationship between these defence classes, and their association with other life history traits, is not well understood. Data on seed coat thickness and fracture resistance, and the abundance and diversity of potential defensive compounds were collected for 10 tree species of Macaranga from Borneo. The data were used to test whether there is a trade-off in physical versus chemical defence investment, and to determine how investment varies with seed mass, and light requirement for regeneration. Across species there was no correlation between seed coat thickness and abundance of potential defensive compounds, indicating the absence of a direct trade-off between defence classes. While chemical defences were not correlated to other traits, physical defences were positively correlated with light requirement for regeneration. For a subset of five Macaranga species we evaluated the relative investment in chemical and physical defence to seed persistence in the soil, measured as the time to half initial seed viability (seed half-life). Half-life was negatively related to the ratio of potential defensive compound abundance to seed coat thickness, suggesting that species with long persistence invested in physical defence more than stored chemical defences. These results indicate that investment in seed defences are associated with species' light requirements for regeneration, rather than scaling positively with seed mass. Furthermore, chemical defences, although highly variable among species, do not appear to be critical to long term persistence of Macaranga seeds, and may be important in defending seeds from natural enemies distinct from those found in the soil.
Environmental and genetic variation of isoflavone content of soybean seeds grown in Brazil
Carr?o-Panizzi, Mercedes Concórdia;Berhow, Mark;Mandarino, José Marcos Gontijo;Oliveira, Maria Cristina Neves de;
Pesquisa Agropecuária Brasileira , 2009, DOI: 10.1590/S0100-204X2009001100011
Abstract: the objective of this work was to evaluate isoflavone concentrations in seeds of different brazilian soybean cultivars grown in a range of locations and environmental conditions in brazil. seeds of 233 cultivars grown in ponta grossa, pr, brazil, during the 2001/2002 soybean season, and of 22 cultivars sown in different locations of brazilian northeast, southeast on south regions were analyzed for total isoflavones, including daidzin, glycitin, genistin and acetylgenistin. the total isoflavones ranged from 12 mg 100 g-1 (cv. embrapa 48) to 461 mg 100 g-1 (cv. cs 305) among the 233 cultivars grown in ponta grossa, and the differences among them are due to genetic effects since all cultivars were grown and collected at the same locatation and year. this is an indication of the possibility of breeding for isoflavone content. differences in isoflavone content observed in the cultivars grown in different locations permit the selection of locations for optimum isoflavone content (low or high), depending on the uses of soybean. in the northeast region (5-8°s), higher concentrations of total isoflavones were observed at s?o raimundo das mangabeiras (232 mg 100 g-1) and tasso fragoso (284 mg 100 g-1) municipalities, and in the south (23-30°s), isoflavones were higher in guarapuava, canoinhas, vacaria and campos novos municipalities, ranging from 130 to 409 mg 100 g-1.
Gender and Anxiety: A Comparison of Student Anxiety Levels in Face-to-Face and Video Conferencing Courses  [PDF]
Jodi McKnight, Mark A. McKnight
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.31015
Abstract: This research focuses on the role of gender in face-to-face instruction and video conferencing instruction on students’ levels of anxiety. This is due, in part, to the fact that gender and anxiety levels of students enrolled in remote video conferencing learning environments has received little attention in either psychological or educational research. A difference in gender as it relates to education is an important focus of research. This is due to the increasing learning opportunities for female students (online in particular). Explored later, further research should investigate various demographics and delivery options for courses.
Forest Fragmentation and Its Potential Implications in the Brazilian Amazon between 2001 and 2010  [PDF]
Izaya Numata, Mark A. Cochrane
Open Journal of Forestry (OJF) , 2012, DOI: 10.4236/ojf.2012.24033
Abstract: In recent decades, human development pressures have results in conversions of vast tracts of Amazonian tropical rain forests to agriculture and other human land uses. In addition to the loss of large forest cover, remaining forests are also fragmented into smaller habitats. Fragmented forests suffer several biological and ecological changes due to edge effects that can exacerbate regional forest degradation. The Brazilian Amazon has had greatly contrasting land cover dynamics in the past decade with the highest historical rates of deforestation (2001-2005) followed by the lowest rates of forest loss in decades, since 2006. Currently, the basin-wide status and implications of forest fragmentation on remnant forests is not well known. We performed a regional forest fragmentation analysis for seven states of the Brazilian Amazon between 2001 and 2010 using a recent deforestation data. During this period, the number of forest fragments (>2 ha) doubled, nearly 125,000 fragments were formed by human activities with more than 50% being smaller than 10 ha. Over the decade, forest edges increased by an average of 36,335 km/year. However, the rate was much greater from 2001-2005 (50,046 km/year) then 2006-2010 (25,365 km/year) when deforestation rates dropped drastically. In 2010, 55% of basin-wide forest edges were < 10 years old due to the creation of large number of small fragments where intensive biological and ecological degradation is ongoing. Over the past decade protected areas have been expanded dramatically over the Brazilian Amazon and, as of 2010, 51% of remaining forests across the basin are within protected areas and only 1.5% of protected areas has been deforested. Conversely, intensive forest cover conversion has been occurred in unprotected forests. While 17% of Amazonian forests are within 1 km of forest edges in 2010, the proportion increases to 34% in unprotected areas varying between 14% and 95% among the studied states. Our results indicate that the Brazilian Amazon now largely consists of two contrasting forest conditions: protected areas with vast undisturbed forests and unprotected forests that are highly fragmented and disturbed landscapes.
The Effects of Forest Thinning Practices and Altered Nutrient Supply on Soil Trace Gas Fluxes in Colorado  [PDF]
Mark A. Gathany, Ingrid C. Burke
Open Journal of Forestry (OJF) , 2014, DOI: 10.4236/ojf.2014.43034

Increases in wildfire activity in the western United States have prompted land managers to reevaluate management practices. In the Colorado Front Range, where population density is high, there is often a great concern regarding wildfire which leads to efforts that will reduce fire hazard. The most common method of achieving this goal is to thin the forest of small diameter trees. Oftentimes these practices are undertaken with little knowledge of the ecological consequences of such treatments. We investigated the effect(s) of three treatments (control, thinning-only and broadcast chipping) on trace gas fluxes (CO2, CH4, and N2O), litter mass, and soil carbon and nitrogen. In a small plot study, we used a 2 × 3 × 3 randomized complete block design to determine the influence of nutrient amendments (woodchips, nitrogen, and phosphorus availability) on trace gas fluxes. The stand-management study revealed that neither thinning-only nor broadcast chipping significantly affected soil carbon or nitrogen, while thinning-only significantly reduced the amount of forest floor litter. Each trace gas flux was significantly affected by the date of sampling (June or August). CO2 and N2O fluxes each had a significant interaction between treatment and sampling date. We attribute this to a difference in moisture availability between the sampling times. In the plot study we found that only the interaction between woodchip addition and phosphorus

Page 1 /475319
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.