287 research outputs found

    Ensuring Nutritional Security for Better Health

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    Citation: Wang WG (2016) Ensuring Nutritional Security for Better Health. J Nutr Food Sci 6:e125. doi:10.4172/2155-9600.100e125Nutrition as a science deals with the interpretation of the interaction of nutrients in growth, reproduction, health, maintenance, and disease of an organism, that includes intake, absorption, assimilation, catabolism and excretion of dietary factors. Nutrition and food science is an international open access journal that publishes scientific articles related to food sciences and nutrition. The current volume no. 6, issue 3 published nine research articles, six review articles along with mini review and commentary articles

    Finite-region boundedness and stabilization for 2D continuous-discrete systems in Roesser model

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    This paper investigates the finite-region boundedness (FRB) and stabilization problems for two-dimensional continuous-discrete linear Roesser models subject to two kinds of disturbances. For two-dimensional continuous-discrete system, we first put forward the concepts of finite-region stability and FRB. Then, by establishing special recursive formulas, sufficient conditions of FRB for two-dimensional continuous-discrete systems with two kinds of disturbances are formulated. Furthermore, we analyze the finite-region stabilization issues for the corresponding two-dimensional continuous-discrete systems and give generic sufficient conditions and sufficient conditions that can be verified by linear matrix inequalities for designing the state feedback controllers which ensure the closed-loop systems FRB. Finally, viable experimental results are demonstrated by illustrative examples

    Development of Novel Liquid Chromatography-Electrospray Tandem Mass Spectrometry Approaches for the Structural Characterization of Brevetoxins Including in vitro Metabolites

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    Brevetoxins are natural neurotoxins that are produced by “red tide†algae. In this study, brevetoxin-1 and brevetoxin-2 were incubated with rat liver hepatocytes and rat liver microsomes, respectively. After clean-up steps, samples were analyzed by liquid chromatography-electrospray mass spectrometry (LC-ES-MS). Two metabolites were found for brevetoxin-1: brevetoxin-1-M1 (MW 900 Da), formed by converting one double bond in the E or F ring into a diol; and brevetoxin-1-M2 (MW 884 Da), a hydrolysis product of brevetoxin-1 involving opening of the lactone ring. The incubation study of brevetoxin-2 found two metabolites. Brevetoxin-2-M1 (MW 912 Da) was elucidated by negative mode LC-MS/MS to be the hydrolysis product of brevetoxin-2. The second metabolite (brevetoxin-2-M2, MW 896 Da) was deduced to be brevetoxin-3. All brevetoxins have high affinities for sodium ions. Attempts to obtain informative product ions from the collision induced decomposition (CID) of [M + Na]+ brevetoxin precursor ions only resulted in uninformative sodium ion signals. In our nano-electrospray experiments, the addition of ammonium fluoride resulted in the formation of the ammonium adduct or protonated brevetoxin with a concomitant decrease of the sodium adduct peak. Product ion spectra of [M + NH4]+ and [M + H]+ were similar and provided useful structural information. The optimal values for ammonium fluoride concentration and the cone voltage were experimentally determined. In negative mode electrospray, without additives, deprotonated molecules of brevetoxins do not appear in high abundances, and thus are not well-suited for CID experiments. Several anions were tested for their abilities to form brevetoxin-anion adducts by mixing ammonium salts of these anions with brevetoxin-2 and brevetoxin-3. Under CID, [M + Cl]-, [M + Br]-, [M + OAc]-, [M + HCOO]-, [M + NO3]- adducts all produced only the respective anions in CID experiments, and thus, gave no structural information. In contrast, upon CID, both [M + F]- and [M + HCO3]- precursor adducts gave structurally-informative fragment peaks that exhibited similarities to those of [M - H]- ions; the detailed fragmentation mechanisms are discussed. In comparison, fluoride is a better choice to study brevetoxins in negative ES-MS by the anionic adduct approach

    Relativistic Hydrodynamic Flows Using Spatial and Temporal Adaptive Structured Mesh Refinement

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    Astrophysical relativistic flow problems require high resolution three-dimensional numerical simulations. In this paper, we describe a new parallel three-dimensional code for simulations of special relativistic hydrodynamics (SRHD) using both spatially and temporally structured adaptive mesh refinement (AMR). We used the method of lines to discretize the SRHD equations spatially and a total variation diminishing (TVD) Runge-Kutta scheme for time integration. For spatial reconstruction, we have implemented piecewise linear method (PLM), piecewise parabolic method (PPM), third order convex essentially non-oscillatory (CENO) and third and fifth order weighted essentially non-oscillatory (WENO) schemes. Flux is computed using either direct flux reconstruction or approximate Riemann solvers including HLL, modified Marquina flux, local Lax-Friedrichs flux formulas and HLLC. The AMR part of the code is built on top of the cosmological Eulerian AMR code {\sl enzo}. We discuss the coupling of the AMR framework with the relativistic solvers. Via various test problems, we emphasize the importance of resolution studies in relativistic flow simulations because extremely high resolution is required especially when shear flows are present in the problem. We also present the results of two 3d simulations of astrophysical jets: AGN jets and GRB jets. Resolution study of those two cases further highlights the need of high resolutions to calculate accurately relativistic flow problems.Comment: 14 pages, 23 figures. A section on 3D GRB jet simulation added. Accepted by ApJ

    Almost Sure Asymptotic Stabilization of Differential Equations with Time-Varying Delay by Lévy Noise

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    This paper aims to determine that the Lévy noise can stabilize the given differential equations with time-varying delay, which has generalized the Brownian motion case. An analysis is developed and sufficient conditions on the stabilization for stochastic differential equations with time-varying delay are presented. Our stabilization criteria is in terms of linear matrix inequalities (LMIs), whence the feedback controls can be designed more easily in practice

    Vitamin A depletion induced by cigarette smoke is associated with an increase in lung cancer-related markers in rats

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    Citation: Xue, Y., Harris, E., Wang, W. Q., & Baybutt, R. C. (2015). Vitamin A depletion induced by cigarette smoke is associated with an increase in lung cancer-related markers in rats. Journal of Biomedical Science, 22, 9. doi:10.1186/s12929-015-0189-0Background: We have previously demonstrated that cigarette smoke is associated with a significant reduction of retinoic acid in rat lungs and the formation of tracheal precancerous lesions. However, the underlying mechanism of cancer risk induced by vitamin A deficiency is unclear. The purpose of this study was to determine whether the cigarette smoke-induced depletion of vitamin A is related to changes in lung cancer risk-related molecular markers. Results: We investigated the roles of the retinoic acid receptors (RARs) as well as other biomarkers for potential cancer risk in the lungs of rats exposed to cigarette smoke. Twenty-four male weanling rats were fed a purified diet and divided equally into four groups. Three experimental groups were exposed to increasing doses of cigarette smoke from 20, 40 or 60 commercial cigarettes/day for 5 days/week. After 6 weeks, the retinoic acid concentrations in the lung tissue as measured via high performance liquid chromatography (HPLC) significantly decreased (P < 0.01) in cigarette smoke exposed groups. Western Blot analysis revealed that cigarette smoke exposure increased lung protein expression of RAR alpha in a threshold manner and decreased RAR beta and RAR gamma expression in a dose-dependent fashion. Protein expressions of cyclin E and proliferating cell nuclear antigen (PCNA) were increased significantly in a dose-dependent manner in cigarette smoke exposed-groups. Additionally, there was a significant increase in protein expression of cJun and cyclin D1 demonstrating a threshold effect similar to that exhibited by RAR alpha, suggesting a potential independent signaling pathway for RAR alpha in lung carcinogenesis. Conclusions: Findings from this study suggest that cigarette smoke-induced lung retinoic acid depletion may involve two independent pathways, RAR alpha- and RAR beta-mediated, responsible for the increased cancer risk associated with cigarette smoke-induced vitamin A deficiency

    On the partial stochastic stability of stochastic differential delay equations with Markovian switching

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    Abstract: In the paper, we are concerned with the partial asymptotic stochastic stability (stability in probability) of stochastic differential delay equations with Markovian switching(SDDEwMSs), the sufficient conditions for partial asymptotic stability in probability have been given and we have generalized some results of Sharov and Ignatyev to cover a class of much more general SDDEwMSs

    Bioconversion of industrial hemp biomass for bioethanol production: A review

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    Industrial hemp (Cannabis sativa L.) with robust drought-resistant features has excellent agronomic and pharmaceutical characteristics. As the federal prohibition on hemp cultivation was lifted, its valorization in various aspects is highly required. This review aims to summarize the potential of hemp biomass for bioethanol production. Chemical compositions of hemp biomass were evaluated as compared with those of corn fiber, corn stover, and sorghum bagasse. Several representative pretreatment technologies used for hemp biomass were summarized in terms of sugar recoveries, lignin removal, and sugar and ethanol yields. This review presents numerous technical barriers attributed to insufficient fermentable sugar and ethanol concentration during the conversion processes. Also, innovative research approaches (pretreatment optimization, co-fermentation of hexose and pentose, increasing potential sugar loading) in overcoming these challenges were critically reviewed. This review would promote future research on the utilization of hemp biomass for biofuel applications
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