Science.gov

Sample records for activated barrier hopping

  1. Elastically cooperative activated barrier hopping theory of relaxation in viscous fluids. I. General formulation and application to hard sphere fluids.

    PubMed

    Mirigian, Stephen; Schweizer, Kenneth S

    2014-05-21

    We generalize the force-level nonlinear Langevin equation theory of single particle hopping to include collective effects associated with long range elastic distortion of the liquid. The activated alpha relaxation event is of a mixed spatial character, involving two distinct, but inter-related, local and collective barriers. There are no divergences at volume fractions below jamming or temperatures above zero Kelvin. The ideas are first developed and implemented analytically and numerically in the context of hard sphere fluids. In an intermediate volume fraction crossover regime, the local cage process is dominant in a manner consistent with an apparent Arrhenius behavior. The super-Arrhenius collective barrier is more strongly dependent on volume fraction, dominates the highly viscous regime, and is well described by a nonsingular law below jamming. The increase of the collective barrier is determined by the amplitude of thermal density fluctuations, dynamic shear modulus or transient localization length, and a growing microscopic jump length. Alpha relaxation time calculations are in good agreement with recent experiments and simulations on dense fluids and suspensions of hard spheres. Comparisons of the theory with elastic models and entropy crisis ideas are explored. The present work provides a foundation for constructing a quasi-universal, fit-parameter-free theory for relaxation in thermal molecular liquids over 14 orders of magnitude in time.

  2. Biotransformations and biological activities of hop flavonoids.

    PubMed

    Karabin, Marcel; Hudcova, Tereza; Jelinek, Lukas; Dostalek, Pavel

    2015-11-01

    Female hop cones are used extensively in the brewing industry, but there is now increasing interest in possible uses of hops for non-brewing purposes, especially in the pharmaceutical industry. Among pharmaceutically important compounds from hops are flavonoids, having proven anticarcinogenic, antioxidant, antimicrobial, anti-inflammatory and estrogenic effects. In this review we aim to present current knowledge on the biotransformation of flavonoids from hop cones with respect to products, catalysis and conversion. A list of microbial enzymatic reactions associated with gastrointestinal microbiota is presented. A comparative analysis of the biological activities of hop flavonoids and their biotransformation products is described, indicating where further research has potential for applications in the pharmaceutical industry.

  3. Random free energy barrier hopping model for ac conduction in chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    Murti, Ram; Tripathi, S. K.; Goyal, Navdeep; Prakash, Satya

    2016-03-01

    The random free energy barrier hopping model is proposed to explain the ac conductivity (σac) of chalcogenide glasses. The Coulomb correlation is consistently accounted for in the polarizability and defect distribution functions and the relaxation time is augmented to include the overlapping of hopping particle wave functions. It is observed that ac and dc conduction in chalcogenides are due to same mechanism and Meyer-Neldel (MN) rule is the consequence of temperature dependence of hopping barriers. The exponential parameter s is calculated and it is found that s is subjected to sample preparation and measurement conditions and its value can be less than or greater than one. The calculated results for a - Se, As2S3, As2Se3 and As2Te3 are found in close agreement with the experimental data. The bipolaron and single polaron hopping contributions dominates at lower and higher temperatures respectively and in addition to high energy optical phonons, low energy optical and high energy acoustic phonons also contribute to the hopping process. The variations of hopping distance with temperature is also studied. The estimated defect number density and static barrier heights are compared with other existing calculations.

  4. Isoxanthohumol--Biologically active hop flavonoid.

    PubMed

    Żołnierczyk, Anna Katarzyna; Mączka, Wanda Krystyna; Grabarczyk, Małgorzata; Wińska, Katarzyna; Woźniak, Edyta; Anioł, Mirosław

    2015-06-01

    Isoxanthohumol (IXN), apart from xanthohumol (XN) and 8-prenylnaringenin (8PN), is one of the most important prenylflavonoids found in hops. Another natural source of this compound is a shrub Sophora flavescens, used in traditional Chinese medicine. Main dietary source of IXN is beer, and the compound is produced from XN during wort boiling. In the human body, the compound is O-demethylated to 8PN, the strongest known phytoestrogen. This process takes place in the liver and in the intestine, where it is mediated by local microflora. It has been reported in some studies that even though beer contains small amounts of hops and its preparations, these compounds may affect the functioning of the human body. IXN exhibits an antiproliferative activity against human cell lines typical for breast cancer (MCF-7), ovarian cancer (A-2780), prostate cancer (DU145 and PC-3), and colon cancer (HT-29 and SW620) cells. It strongly inhibits the activation of the following carcinogens: 2-amino-3-methylimidazol-[4,5-f]quinoline and aflatoxin B1 (AFB1) via human cytochrome P450 (CYP1A2). It also inhibits the production of prostate specific antigen (PSA). IXN significantly reduces the expression of transforming growth factor-β (TGF-β) in the case of invasive breast cancer MDA-MB-231. It interferes with JAK/STAT signaling pathway and inhibits the expression of pro1inflammatory genes in the monoblastic leukemia cell line (MonoMac6). It activates apoptosis in human umbilical vein endothelial cells (HUVEC) and human aortic smooth muscle cells (HASMCs). In addition, IXN shows an antiviral activity towards herpes viruses (HSV1 and HSV2) and bovine viral diarrhea virus (BVDV).

  5. Comparison of the odor-active compounds in unhopped beer and beers hopped with different hop varieties.

    PubMed

    Kishimoto, Toru; Wanikawa, Akira; Kono, Katsunori; Shibata, Kazunori

    2006-11-15

    Odorants comprising the hop aromas of beers were examined. Strongly hopped beers with Saazer, Hersbrucker, and Cascade hops were compared with unhopped beer by gas chromatography-olfactometry (CharmAnalysis) and sensory evaluation. Twenty-seven odorants were revealed as hop-derived, which derived either directly from hops or via metabolization, and 19 components were identified. Of the components, linalool, geraniol, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, and ethyl 2-methylpropanoate were determined as odor-active components from their Charm values and aroma values. The muscat-like aroma of Cascade beer and the spicy aroma of Hersbrucker beer were predominant in sensory evaluation, and the contributors to these characteristics were investigated.

  6. Activated-like hopping transition in weakly vibrated granular media

    NASA Astrophysics Data System (ADS)

    D'Anna, G.; Gremaud, G.

    2001-06-01

    The slow dynamics of a weakly vibrated granular medium is investigated using a low-frequency forced torsion pendulum method. A loss factor peak is observed in the pendulum response (or the granular susceptibility) as a function of the vibration intensity or the forcing frequency. The position of the peak follows an Arrhenius-like behaviour and the data can be described as an activated hopping process. The peak can be seen as a vibration-induced glass-like transition between a low-Γ jammed phase and the high-Γ fluid-like phase.

  7. Factors affecting antibacterial activity of hop compounds and their derivatives.

    PubMed

    Simpson, W J; Smith, A R

    1992-04-01

    The antibacterial effect of weak acids derived from the hop plant (Humulus lupulus L.) increased with decreasing pH. Analysis of the minimum inhibitory concentration of such compounds against Lactobacillus brevis IFO 3960 over pH 4-7 suggests that undissociated molecules were mainly responsible for inhibition of bacterial growth. The antibacterial activity of trans-isohumulone was ca 20 times greater than that of humulone, 11 times greater than that of colupulone and nine times greater than that of trans-humulinic acid when the degree of ionization was taken into account. Monovalent cations (K+, Na+, NH4+, Rb+, Li+) stimulated antibacterial activity of trans-isohumulone but the effect was smaller than that observed with H+. The response to divalent cations varied: Ca2+ had little effect on antibacterial activity, whereas Mg2+ reduced activity. Lipid materials and beta-cyclodextrin also antagonized the antibacterial action of trans-isohumulone.

  8. Antifeedant activity of xanthohumol and supercritical carbon dioxide extract of spent hops against stored product pests.

    PubMed

    Jackowski, J; Hurej, M; Rój, E; Popłoński, J; Kośny, L; Huszcza, E

    2015-08-01

    Xanthohumol, a prenylated flavonoid from hops, and a supercritical carbon dioxide extract of spent hops were studied for their antifeedant activity against stored product insect pests: Sitophilus granarius L., Tribolium confusum Duv. and Trogoderma granarium Everts. Xanthohumol exhibited medium deterrent activity against the adults of S. granarius L. and larvae of T. confusum Duv. The spent hops extract was more active than xanthohumol towards the adults of T. confusum Duv. The potential application of the crude spent hops extract as a feeding deterrent against the stored product pests is proposed.

  9. Three-dimensional numerical simulations for activated hopping conduction

    NASA Astrophysics Data System (ADS)

    Zimmerman, Dan S.; Shegelski, Mark R. A.

    1988-07-01

    We model hopping conduction in a three-dimensional, lightly doped compensated semiconductor using a Miller-Abrahams-type resistor network. A flat density of states of width Δɛ is used. We work with the full expression for the resistances instead of the T-->0 asymptotic form usually employed. We report the first detailed numerical calculations of the overall resistance of a three-dimensional resistor network using this full expression. We find a temperature regime where the hopping conduction has a ratio of activation energy to bandwidth ɛ~3=ɛ3/Δɛ=0.217(8). This value agrees with the analytically determined value calculated by Shegelski and Barrie (SB), and disagrees with results reported by other workers, thereby validating SB's analytic theory and their claim that the full expression for the resistor network should be used in calculations of ɛ~3. An investigation is made into the dependence of ɛ~3 on Δɛ we find, in qualitative agreement with SB, that ɛ~3 decreases with Δɛ and we present improved values for ɛ~3 as a function of Δɛ.

  10. Electrochemical versus spectrophotometric assessment of antioxidant activity of hop (Humulus lupulus L.) products and individual compounds.

    PubMed

    Gorjanović, Stanislava; Pastor, Ferenc T; Vasić, Radica; Novaković, Miroslav; Simonović, Mladen; Milić, Sonja; Sužnjević, Desanka

    2013-09-25

    Antioxidant (AO) activity of extracts of hop cones (Serbian domestic varieties) and commercial hop products (Saaz, Spalter, Spalter select, and Magnum pellets) was determined by parallel application of recently developed direct current (DC) polarographic and widely used DPPH assay. Correlations between 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging and total phenolics (TPC) determined by the Folin-Ciocalteu assay (FC) (0.99), and between H2O2 scavenging (HPS) and humulone content (H) determined by conductometric method (0.94), total resins (TR) (0.85), and hop storage index (HIS) (-0.90), were found statistically significant at p < 0.05 level while complete lack of HPS correlation with TPC and DPPH was observed. To obtain an insight into differences between results of AO assays applied, activity of individual compounds, prevalent hop phenolics, and bitter acids was determined. By far superior HPS activity of humulone was followed by catechin, quercetin, xanthohumol, lupulone, and rutin. In contrast, DPPH scavenging activity of phenolics (quercetin > catechin > rutin > xantohumol) was found substantially higher than activity of bitter acids. According to ferric reducing antioxidant power (FRAP) and scavenging of 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), higher AO activity was ascribed to phenolics, while almost neglecting humulone. Besides reliability, low cost, and an easy-to-handle procedure, an ability to recognize humulone as the major contributor of hop AO activity could allow DC polarographic assay to be applied in analysis of various hop-derived products.

  11. Involvement of Vacuolar Sequestration and Active Transport in Tolerance of Saccharomyces cerevisiae to Hop Iso-α-Acids▿ † ¶

    PubMed Central

    Hazelwood, Lucie A.; Walsh, Michael C.; Pronk, Jack T.; Daran, Jean-Marc

    2010-01-01

    The hop plant, Humulus lupulus L., has an exceptionally high content of secondary metabolites, the hop α-acids, which possess a range of beneficial properties, including antiseptic action. Studies performed on the mode of action of hop iso-α-acids have hitherto been restricted to lactic acid bacteria. The present study investigated molecular mechanisms of hop iso-α-acid resistance in the model eukaryote Saccharomyces cerevisiae. Growth inhibition occurred at concentrations of hop iso-α-acids that were an order of magnitude higher than those found with hop-tolerant prokaryotes. Chemostat-based transcriptome analysis and phenotype screening of the S. cerevisiae haploid gene deletion collection were used as complementary methods to screen for genes involved in hop iso-α-acid detoxification and tolerance. This screening and further analysis of deletion mutants confirmed that yeast tolerance to hop iso-α-acids involves three major processes, active proton pumping into the vacuole by the vacuolar-type ATPase to enable vacuolar sequestration of iso-α-acids and alteration of cell wall structure and, to a lesser extent, active export of iso-α-acids across the plasma membrane. Furthermore, iso-α-acids were shown to affect cellular metal homeostasis by acting as strong zinc and iron chelators. PMID:19915041

  12. Involvement of vacuolar sequestration and active transport in tolerance of Saccharomyces cerevisiae to hop iso-alpha-acids.

    PubMed

    Hazelwood, Lucie A; Walsh, Michael C; Pronk, Jack T; Daran, Jean-Marc

    2010-01-01

    The hop plant, Humulus lupulus L., has an exceptionally high content of secondary metabolites, the hop alpha-acids, which possess a range of beneficial properties, including antiseptic action. Studies performed on the mode of action of hop iso-alpha-acids have hitherto been restricted to lactic acid bacteria. The present study investigated molecular mechanisms of hop iso-alpha-acid resistance in the model eukaryote Saccharomyces cerevisiae. Growth inhibition occurred at concentrations of hop iso-alpha-acids that were an order of magnitude higher than those found with hop-tolerant prokaryotes. Chemostat-based transcriptome analysis and phenotype screening of the S. cerevisiae haploid gene deletion collection were used as complementary methods to screen for genes involved in hop iso-alpha-acid detoxification and tolerance. This screening and further analysis of deletion mutants confirmed that yeast tolerance to hop iso-alpha-acids involves three major processes, active proton pumping into the vacuole by the vacuolar-type ATPase to enable vacuolar sequestration of iso-alpha-acids and alteration of cell wall structure and, to a lesser extent, active export of iso-alpha-acids across the plasma membrane. Furthermore, iso-alpha-acids were shown to affect cellular metal homeostasis by acting as strong zinc and iron chelators.

  13. Conduction mechanisms in P(VDF-TrFE)/gold nanowire composites: tunnelling and thermally-activated hopping process near the percolation threshold

    NASA Astrophysics Data System (ADS)

    Ramachandran, Laavanya; Lonjon, Antoine; Demont, Philippe; Dantras, Eric; Lacabanne, Colette

    2016-08-01

    High-aspect ratio gold nanowires were dispersed in a P(VDF-TrFE) matrix to form conducting polymer composites. The composites were found to follow a percolation law, with a low percolation threshold of 2.2%vol and attaining a conductivity value of 100 S m-1. The temperature and frequency dependence of the composites were studied using broadband dielectric spectroscopy. Tunnelling was found to be the main charge transport mechanism at temperatures below -100 °C and a thermally-activated hopping mechanism was determined to be responsible for conduction at temperatures above -100 °C. The correlated barrier hopping model was found to be the best fit to explain the conduction mechanisms in the composites.

  14. Molecular mechanisms behind the antimicrobial activity of hop iso-α-acids in Lactobacillus brevis.

    PubMed

    Schurr, Benjamin C; Hahne, Hannes; Kuster, Bernhard; Behr, Jürgen; Vogel, Rudi F

    2015-04-01

    The main bittering component in beer, hop iso-α-acids, have been characterised as weak acids, which act as ionophores impairing microbial cells' function under acidic conditions as present in beer. Besides medium pH, divalent cations play a central role regarding the efficacy of the antimicrobial effect. The iso-α-acids' non-bitter derivatives humulinic acids can be found in isomerised hop extracts and can be generated during hop storage. Therefore, they have been under investigation concerning their influence on beer sensory properties. This study sketches the molecular mechanism behind iso-α-acids' antimicrobial activity in Lactobacillus (L.) brevis regarding their ionophore activity versus the dependence of the inhibitory potential on manganese binding, and suggests humulinic acids as novel tasteless food preservatives. We designed and synthesised chemically modified iso-α-acids to enhance the basic understanding of the molecular mechanism of antimicrobial iso-α-acids. It could be observed that a manganese-binding dependent transmembrane redox reaction (oxidative stress) plays a crucial role in inhibition. Privation of an acidic hydroxyl group neither erased ionophore activity, nor did it entirely abolish antimicrobial activity. Humulinic acids proved to be highly inhibitory, even outperforming iso-α-acids.

  15. Structural Basis of Human PXR Activation by the Hops Constituent Colupulone

    PubMed Central

    Teotico, Denise G.; Bischof, Jason J.; Peng, Li; Kliewer, Steven A.; Redinbo, Matthew R.

    2008-01-01

    Hops extracts are used to alleviate menopausal symptoms and as an alternative to hormone replacement therapy, but can produce potentially harmful drug-drug interactions. The nuclear xenobiotic receptor PXR is promiscuously activated by a range of structurally distinct chemicals. It has a key role in the transcriptional regulation of genes that encode xenobiotic metabolism enzymes. In this study, hops extracts are shown to induce the expression of numerous drug metabolism and excretion proteins. The β-bitter acid colupulone is demonstrated to be a bioactive component and direct activator of human PXR. The 2.8 Å resolution crystal structure of the ligand binding domain of human PXR in complex with colupulone was elucidated, and colupulone was observed to bind in a single orientation stabilized by both Van der Waals and hydrogen bonding contacts. The crystal structure also indicates that related α- and β-bitter acids have the capacity to serve as PXR agonists, as well. Taken together, these results reveal the structural basis for drug-drug interactions mediated by colupulone and related constituents of hops extracts. PMID:18768384

  16. Barriers to Physical Activity on University Student

    NASA Astrophysics Data System (ADS)

    Jajat; Sultoni, K.; Suherman, A.

    2017-03-01

    The purpose of the research is to analyze the factors that become barriers to physical activity in university students based on physical activity level. An internet-based survey was conducted. The participants were 158 University students from Universitas Pendidikan Indonesia. Barriers to Physical Activity Quiz (BPAQ) were used to assessed the factors that become barriers to physical activity in university students. IPAQ (short form) were used to assessed physical activity level. The results show there was no differences BPAQ based on IPAQ level. But when analyzed further based on seven factors barriers there are differences in factors “social influence and lack of willpower” based IPAQ level. Based on this it was concluded that the “influence from other and lack of willpower” an inhibiting factor on students to perform physical activity.

  17. Deterrent activity of hops flavonoids and their derivatives against stored product pests.

    PubMed

    Jackowski, J; Popłoński, J; Twardowska, K; Magiera-Dulewicz, J; Hurej, M; Huszcza, E

    2017-02-16

    Five flavonoids from hops, two of their derivatives, along with naringenin used as a model compound, were tested for their antifeedant activity against three coleopteran stored product pests: Sitophilus granarius L., Tribolium confusum Duv. and Trogoderma granarium Everts. The introduction, into the tested flavonoid molecules, of additional structural fragments such as prenyl or dimethylpyran moiety, is proposed to significantly alter the deterrent activity of the compounds. The prenyl moiety in flavonoids increased the deterrent activity of these compounds in all three of the grain feeding species used in the tests. It is also concluded that the introduction of dimethylpyran moiety to the flavonoid structure increases its deterrent activity in S. granarius and T. confusum, but in one of the test insects, T. granarium, an increased feeding was observed in response to the introduction of dimethylpyran moiety to the flavonoid structure.

  18. Activation of Cryptic hop Genes from Streptomyces peucetius ATCC 27952 Involved in Hopanoid Biosynthesis.

    PubMed

    Ghimire, Gopal Prasad; Koirala, Niranjan; Sohng, Jae Kyung

    2015-05-01

    Genes encoding enzymes with sequence similarity to hopanoids biosynthetic enzymes of other organisms were cloned from the hopanoid (hop) gene cluster of Streptomyces peucetius ATCC 27952 and transformed into Streptomyces venezuelae YJ028. The cloned fragments contained four genes, all transcribed in one direction. These genes encode polypeptides that resemble polyprenyl diphosphate synthase (hopD), squalene-phytoene synthases (hopAB), and squalenehopene cyclase (hopE). These enzymes are sufficient for the formation of the pentacyclic triterpenoid lipid, hopene. The formation of hopene was verified by gas chromatography/ mass spectrometry.

  19. Hop derived flavonoid xanthohumol inhibits endothelial cell functions via AMPK activation.

    PubMed

    Gallo, Cristina; Dallaglio, Katiuscia; Bassani, Barbara; Rossi, Teresa; Rossello, Armando; Noonan, Douglas M; D'Uva, Gabriele; Bruno, Antonino; Albini, Adriana

    2016-09-13

    Angiogenesis, a process characterized by the formation of new blood vessels from pre-existing ones, is a crucial step in tumor growth and dissemination. Recently, increased attention has been addressed to the ability of flavonoids to prevent cancer by suppressing angiogenesis, strategy that we named "angioprevention". Several natural compounds exert their anti-tumor properties by activating 5' adenosine monophosphate-activated protein kinase (AMPK), a key regulator of metabolism in cancer cells. Drugs with angiopreventive activities, in particular metformin, regulate AMPK in endothelial cells. Here we investigated the involvement of AMPK in the anti-angiogenic effects of xanthohumol (XN), the major prenylated flavonoid of the hop plant, and mechanisms of action. The anti-angiogenic activity of XN was more potent than epigallocatechin-3-gallate (EGCG). Treatment of endothelial cells with XN led to increased AMPK phosphorylation and activity. Functional studies using biochemical approaches confirmed that AMPK mediates XN anti-angiogenic activity. AMPK activation by XN was mediated by CAMMKβ, but not LKB1. Analysis of the downstream mechanisms showed that XN-induced AMPK activation reduced nitric oxide (NO) levels in endothelial cells by decreasing eNOS phosphorylation. Finally, AKT pathway was inactivated by XN as part of its anti-angiogenic activity, but independently from AMPK, suggesting that these two signaling pathways proceed autonomously. Our study dissects the molecular mechanism by which XN exerts its potent anti-angiogenic activity, pointing out AMPK as a crucial signal transducer.

  20. Hop derived flavonoid xanthohumol inhibits endothelial cell functions via AMPK activation

    PubMed Central

    Gallo, Cristina; Dallaglio, Katiuscia; Bassani, Barbara; Rossi, Teresa; Rossello, Armando; Noonan, Douglas M.; D'Uva, Gabriele; Bruno, Antonino; Albini, Adriana

    2016-01-01

    Angiogenesis, a process characterized by the formation of new blood vessels from pre-existing ones, is a crucial step in tumor growth and dissemination. Recently, increased attention has been addressed to the ability of flavonoids to prevent cancer by suppressing angiogenesis, strategy that we named “angioprevention”. Several natural compounds exert their anti-tumor properties by activating 5′ adenosine monophosphate-activated protein kinase (AMPK), a key regulator of metabolism in cancer cells. Drugs with angiopreventive activities, in particular metformin, regulate AMPK in endothelial cells. Here we investigated the involvement of AMPK in the anti-angiogenic effects of xanthohumol (XN), the major prenylated flavonoid of the hop plant, and mechanisms of action. The anti-angiogenic activity of XN was more potent than epigallocatechin-3-gallate (EGCG). Treatment of endothelial cells with XN led to increased AMPK phosphorylation and activity. Functional studies using biochemical approaches confirmed that AMPK mediates XN anti-angiogenic activity. AMPK activation by XN was mediated by CAMMKβ, but not LKB1. Analysis of the downstream mechanisms showed that XN-induced AMPK activation reduced nitric oxide (NO) levels in endothelial cells by decreasing eNOS phosphorylation. Finally, AKT pathway was inactivated by XN as part of its anti-angiogenic activity, but independently from AMPK, suggesting that these two signaling pathways proceed autonomously. Our study dissects the molecular mechanism by which XN exerts its potent anti-angiogenic activity, pointing out AMPK as a crucial signal transducer. PMID:27494895

  1. Matured Hop Bittering Components Induce Thermogenesis in Brown Adipose Tissue via Sympathetic Nerve Activity

    PubMed Central

    Morimoto-Kobayashi, Yumie; Ohara, Kazuaki; Takahashi, Chika; Kitao, Sayoko; Wang, Guanying; Taniguchi, Yoshimasa; Katayama, Mikio; Nagai, Katsuya

    2015-01-01

    Obesity is the principal symptom of metabolic syndrome, which refers to a group of risk factors that increase the likelihood of atherosclerosis. In recent decades there has been a sharp rise in the incidence of obesity throughout the developed world. Iso-α-acids, the bitter compounds derived from hops in beer, have been shown to prevent diet-induced obesity by increasing lipid oxidation in the liver and inhibition of lipid absorption from the intestine. Whereas the sharp bitterness induced by effective dose of iso-α-acids precludes their acceptance as a nutrient, matured hop bittering components (MHB) appear to be more agreeable. Therefore, we tested MHB for an effect on ameliorating diet-induced body fat accumulation in rodents. MHB ingestion had a beneficial effect but, compared to iso-α-acids and despite containing structurally similar compounds, acted via different mechanisms to reduce body fat accumulation. MHB supplementation significantly reduced body weight gain, epididymal white adipose tissue weight, and plasma non-esterified free fatty acid levels in diet-induced obese mice. We also found that uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT) was significantly increased in MHB-fed mice at both the mRNA and protein levels. In addition, MHB administration in rats induced the β-adrenergic signaling cascade, which is related to cAMP accumulation in BAT, suggesting that MHB could modulate sympathetic nerve activity innervating BAT (BAT-SNA). Indeed, single oral administration of MHB elevated BAT-SNA in rats, and this elevation was dissipated by subdiaphragmatic vagotomy. Single oral administration of MHB maintained BAT temperature at a significantly higher level than in control rats. Taken together, these findings indicate that MHB ameliorates diet-induced body fat accumulation, at least partly, by enhancing thermogenesis in BAT via BAT-SNA activation. Our data suggests that MHB is a useful tool for developing functional foods or

  2. Matured Hop Bittering Components Induce Thermogenesis in Brown Adipose Tissue via Sympathetic Nerve Activity.

    PubMed

    Morimoto-Kobayashi, Yumie; Ohara, Kazuaki; Takahashi, Chika; Kitao, Sayoko; Wang, Guanying; Taniguchi, Yoshimasa; Katayama, Mikio; Nagai, Katsuya

    2015-01-01

    Obesity is the principal symptom of metabolic syndrome, which refers to a group of risk factors that increase the likelihood of atherosclerosis. In recent decades there has been a sharp rise in the incidence of obesity throughout the developed world. Iso-α-acids, the bitter compounds derived from hops in beer, have been shown to prevent diet-induced obesity by increasing lipid oxidation in the liver and inhibition of lipid absorption from the intestine. Whereas the sharp bitterness induced by effective dose of iso-α-acids precludes their acceptance as a nutrient, matured hop bittering components (MHB) appear to be more agreeable. Therefore, we tested MHB for an effect on ameliorating diet-induced body fat accumulation in rodents. MHB ingestion had a beneficial effect but, compared to iso-α-acids and despite containing structurally similar compounds, acted via different mechanisms to reduce body fat accumulation. MHB supplementation significantly reduced body weight gain, epididymal white adipose tissue weight, and plasma non-esterified free fatty acid levels in diet-induced obese mice. We also found that uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT) was significantly increased in MHB-fed mice at both the mRNA and protein levels. In addition, MHB administration in rats induced the β-adrenergic signaling cascade, which is related to cAMP accumulation in BAT, suggesting that MHB could modulate sympathetic nerve activity innervating BAT (BAT-SNA). Indeed, single oral administration of MHB elevated BAT-SNA in rats, and this elevation was dissipated by subdiaphragmatic vagotomy. Single oral administration of MHB maintained BAT temperature at a significantly higher level than in control rats. Taken together, these findings indicate that MHB ameliorates diet-induced body fat accumulation, at least partly, by enhancing thermogenesis in BAT via BAT-SNA activation. Our data suggests that MHB is a useful tool for developing functional foods or

  3. Evaluation of estrogenic activity of licorice species in comparison with hops used in botanicals for menopausal symptoms.

    PubMed

    Hajirahimkhan, Atieh; Simmler, Charlotte; Yuan, Yang; Anderson, Jeffrey R; Chen, Shao-Nong; Nikolić, Dejan; Dietz, Birgit M; Pauli, Guido F; van Breemen, Richard B; Bolton, Judy L

    2013-01-01

    The increased cancer risk associated with hormone therapies has encouraged many women to seek non-hormonal alternatives including botanical supplements such as hops (Humulus lupulus) and licorice (Glycyrrhiza spec.) to manage menopausal symptoms. Previous studies have shown estrogenic properties for hops, likely due to the presence of 8-prenylnarigenin, and chemopreventive effects mainly attributed to xanthohumol. Similarly, a combination of estrogenic and chemopreventive properties has been reported for various Glycyrrhiza species. The major goal of the current study was to evaluate the potential estrogenic effects of three licorice species (Glycyrrhiza glabra, G. uralensis, and G. inflata) in comparison with hops. Extracts of Glycyrrhiza species and spent hops induced estrogen responsive alkaline phosphatase activity in endometrial cancer cells, estrogen responsive element (ERE)-luciferase in MCF-7 cells, and Tff1 mRNA in T47D cells. The estrogenic activity decreased in the order H. lupulus > G. uralensis > G. inflata > G. glabra. Liquiritigenin was found to be the principle phytoestrogen of the licorice extracts; however, it exhibited lower estrogenic effects compared to 8-prenylnaringenin in functional assays. Isoliquiritigenin, the precursor chalcone of liquiritigenin, demonstrated significant estrogenic activities while xanthohumol, a metabolic precursor of 8-prenylnaringenin, was not estrogenic. Liquiritigenin showed ERβ selectivity in competitive binding assay and isoliquiritigenin was equipotent for ER subtypes. The estrogenic activity of isoliquiritigenin could be the result of its cyclization to liquiritigenin under physiological conditions. 8-Prenylnaringenin had nanomolar estrogenic potency without ER selectivity while xanthohumol did not bind ERs. These data demonstrated that Glycyrrhiza species with different contents of liquiritigenin have various levels of estrogenic activities, suggesting the importance of precise labeling of botanical

  4. Comparison of the in vitro estrogenic activities of compounds from hops (Humulus lupulus) and red clover (Trifolium pratense).

    PubMed

    Overk, Cassia R; Yao, Ping; Chadwick, Lucas R; Nikolic, Dejan; Sun, Yongkai; Cuendet, Muriel A; Deng, Yunfan; Hedayat, A S; Pauli, Guido F; Farnsworth, Norman R; van Breemen, Richard B; Bolton, Judy L

    2005-08-10

    Because the prevailing form of hormone replacement therapy is associated with the development of cancer in breast and endometrial tissues, alternatives are needed for the management of menopausal symptoms. Formulations of Trifolium pratense L. (red clover) are being used to alleviate menopause-associated hot flashes but have shown mixed results in clinical trials. The strobiles of Humulus lupulusL. (hops) have been reported to contain the prenylflavanone, 8-prenylnaringenin (8-PN), as the most estrogenic constituent, and this was confirmed using an estrogen receptor ligand screening assay utilizing ultrafiltration mass spectrometry. Extracts of hops and red clover and their individual constituents including 8-PN, 6-prenylnaringenin (6-PN), isoxanthohumol (IX), and xanthohumol (XN) from hops and daidzein, formononetin, biochanin A, and genistein from red clover were compared using a variety of in vitro estrogenic assays. The IC50 values for the estrogen receptor alpha and beta binding assays were 15 and 27 microg/mL, respectively, for hops and 18.0 and 2.0 microg/mL, respectively, for the red clover extract. Both of the extracts, genistein, and 8-PN activated the estrogen response element (ERE) in Ishikawa cells while the extracts, biochanin A, genistein, and 8-PN, significantly induced ERE-luciferase expression in MCF-7 cells. Hop and red clover extracts as well as 8-PN up-regulated progesterone receptor (PR) mRNA in the Ishikawa cell line. In the MCF-7 cell line, PR mRNA was significantly up-regulated by the extracts, biochanin A, genistein, 8-PN, and IX. The two extracts had EC50 values of 1.1 and 1.9 microg/mL, respectively, in the alkaline phosphatase induction assay. On the basis of these data, hops and red clover could be attractive for the development as herbal dietary supplements to alleviate menopause-associated symptoms.

  5. Understanding Motivators and Barriers to Physical Activity

    ERIC Educational Resources Information Center

    Patay, Mary E.; Patton, Kevin; Parker, Melissa; Fahey, Kathleen; Sinclair, Christina

    2015-01-01

    The purpose of this study was to understand the factors that influence physical activity among year-round residents in an isolated summer resort community. Specifically, we explored the personal, environmental, social, and culture-specific perceived motivators and barriers to physical activity. Participants were formally interviewed about their…

  6. Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus), Prevents Platelet Activation in Human Platelets.

    PubMed

    Lee, Ye-Ming; Hsieh, Kuo-Hsien; Lu, Wan-Jung; Chou, Hsiu-Chu; Chou, Duen-Suey; Lien, Li-Ming; Sheu, Joen-Rong; Lin, Kuan-Hung

    2012-01-01

    Xanthohumol is the principal prenylated flavonoid in the hop plant (Humulus lupulus L.). Xanthohumol was found to be a very potent cancer chemopreventive agent through regulation of diverse mechanisms. However, no data are available concerning the effects of xanthohumol on platelet activation. The aim of this paper was to examine the antiplatelet effect of xanthohumol in washed human platelets. In the present paper, xanthohumol exhibited more-potent activity in inhibiting platelet aggregation stimulated by collagen. Xanthohumol inhibited platelet activation accompanied by relative [Ca(2+)](i) mobilization, thromboxane A(2) formation, hydroxyl radical (OH(●)) formation, and phospholipase C (PLC)γ2, protein kinase C (PKC), mitogen-activated protein kinase (MAPK), and Akt phosphorylation. Neither SQ22536, an inhibitor of adenylate cyclase, nor ODQ, an inhibitor of guanylate cyclase, reversed the xanthohumol-mediated inhibitory effect on platelet aggregation. Furthermore, xanthohumol did not significantly increase nitrate formation in platelets. This study demonstrates for the first time that xanthohumol possesses potent antiplatelet activity which may initially inhibit the PI3-kinase/Akt, p38 MAPK, and PLCγ2-PKC cascades, followed by inhibition of the thromboxane A(2) formation, thereby leading to inhibition of [Ca(2+)](i) and finally inhibition of platelet aggregation. Therefore, this novel role of xanthohumol may represent a high therapeutic potential for treatment or prevention of cardiovascular diseases.

  7. Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus), Prevents Platelet Activation in Human Platelets

    PubMed Central

    Lee, Ye-Ming; Hsieh, Kuo-Hsien; Lu, Wan-Jung; Chou, Hsiu-Chu; Chou, Duen-Suey; Lien, Li-Ming; Sheu, Joen-Rong; Lin, Kuan-Hung

    2012-01-01

    Xanthohumol is the principal prenylated flavonoid in the hop plant (Humulus lupulus L.). Xanthohumol was found to be a very potent cancer chemopreventive agent through regulation of diverse mechanisms. However, no data are available concerning the effects of xanthohumol on platelet activation. The aim of this paper was to examine the antiplatelet effect of xanthohumol in washed human platelets. In the present paper, xanthohumol exhibited more-potent activity in inhibiting platelet aggregation stimulated by collagen. Xanthohumol inhibited platelet activation accompanied by relative [Ca2+]i mobilization, thromboxane A2 formation, hydroxyl radical (OH●) formation, and phospholipase C (PLC)γ2, protein kinase C (PKC), mitogen-activated protein kinase (MAPK), and Akt phosphorylation. Neither SQ22536, an inhibitor of adenylate cyclase, nor ODQ, an inhibitor of guanylate cyclase, reversed the xanthohumol-mediated inhibitory effect on platelet aggregation. Furthermore, xanthohumol did not significantly increase nitrate formation in platelets. This study demonstrates for the first time that xanthohumol possesses potent antiplatelet activity which may initially inhibit the PI3-kinase/Akt, p38 MAPK, and PLCγ2-PKC cascades, followed by inhibition of the thromboxane A2 formation, thereby leading to inhibition of [Ca2+]i and finally inhibition of platelet aggregation. Therefore, this novel role of xanthohumol may represent a high therapeutic potential for treatment or prevention of cardiovascular diseases. PMID:22611436

  8. Hopping robot

    DOEpatents

    Spletzer, Barry L.; Fischer, Gary J.; Marron, Lisa C.; Martinez, Michael A.; Kuehl, Michael A.; Feddema, John T.

    2001-01-01

    The present invention provides a hopping robot that includes a misfire tolerant linear actuator suitable for long trips, low energy steering and control, reliable low energy righting, miniature low energy fuel control. The present invention provides a robot with hopping mobility, capable of traversing obstacles significant in size relative to the robot and capable of operation on unpredictable terrain over long range. The present invention further provides a hopping robot with misfire-tolerant combustion actuation, and with combustion actuation suitable for use in oxygen-poor environments.

  9. In vitro evaluation of antibacterial, anticollagenase, and antioxidant activities of hop components (Humulus lupulus) addressing acne vulgaris.

    PubMed

    Yamaguchi, Naoto; Satoh-Yamaguchi, Keiko; Ono, Mitsunori

    2009-04-01

    Seven naturally derived components from hop plant (Humulus lupulus L.) extracts were tested for evaluation of biological activities affecting acne vulgaris. Five strains, Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus, Kocuria rhizophila and, Staphylococcus pyogenes, were selected as the main acne-causing bacteria. Hop extracts xanthohumol and the lupulones showed strong inhibitory activities against all of the strains. Although hydrogenated derivatives did not show the same level of activity, naturally occurring xanthohumol, humulones, and lupulones all showed moderate to strong anticollagenase inhibitory activities. Antioxidant capacity was also evaluated with seven different methods based on different reactive oxygen species. Xanthohumol showed the highest activity in total oxygen radical absorbance capacity as well as singlet oxygen absorbance capacity.

  10. Antilisterial activity of hops beta acids in broth with or without other antimicrobials.

    PubMed

    Shen, C; Sofos, J N

    2008-11-01

    Hops beta acids (HBA) are parts of hops flowers used to preserve wort and provide flavor in beer, and are reported as having antimicrobial properties. This study evaluated the antilisterial activity of HBA alone or in combination with other known antimicrobials in a culture broth medium. Listeria monocytogenes (10-strain mixture) was inoculated (2.6 to 2.8 log CFU/mL) into tryptic soy broth supplemented with 0.6% yeast extract (TSBYE) without (control) or with HBA (0.5 to 5.0 microg/mL), potassium lactate (1.0%), sodium diacetate (0.25%), or acetic acid (0.1%), alone or in combination with HBA (0.5 to 3.0 microg/mL). Survival/growth of the pathogen during storage at 4 degrees C (35 d), 10 degrees C (20 d), or 25 degrees C (2 d) was periodically monitored by spiral plating onto tryptic soy agar plus 0.6% yeast extract. As expected, TSBYE without antimicrobials (control) supported rapid pathogen growth with growth rates of 0.40, 2.88, and 9.58 log CFU/mL/d at 4, 10, and 25 degrees C, respectively; corresponding Y(end) values exceeded 9.0 log CFU/mL at 35, 20, and 2 d storage. HBA used alone (1.0 to 5.0 microg/mL) inhibited growth of L. monocytogenes at all 3 temperatures, with inhibition being more pronounced at higher concentrations and at the lower storage temperature (4 degrees C). The antilisterial activity of HBA (0.5 to 3.0 microg/mL) was enhanced when combined with sodium diacetate, acetic acid, or potassium lactate, achieving complete inhibition at 4 degrees C when 3.0 microg/mL HBA were used in combination with each of the above antimicrobials. Overall, HBA exhibited promising antilisterial activity in a broth medium and further studies are needed to investigate its potential antilisterial effects in food products.

  11. Eubacterium limosum activates isoxanthohumol from hops (Humulus lupulus L.) into the potent phytoestrogen 8-prenylnaringenin in vitro and in rat intestine.

    PubMed

    Possemiers, Sam; Rabot, Sylvie; Espín, Juan Carlos; Bruneau, Aurélia; Philippe, Catherine; González-Sarrías, Antonio; Heyerick, Arne; Tomás-Barberán, Francisco A; De Keukeleire, Denis; Verstraete, Willy

    2008-07-01

    Recently, it was shown that the exposure to the potent hop phytoestrogen 8-prenylnaringenin (8-PN) depends on intestinal bacterial activation of isoxanthohumol (IX), but this occurs in only one-third of tested individuals. As the butyrate-producing Eubacterium limosum can produce 8-PN from IX, a probiotic strategy was applied to investigate whether 8-PN production could be increased in low 8-PN producers, thus balancing phytoestrogen exposure. Using fecal samples from high (Hop +) and low (Hop -) 8-PN-producing individuals, a Hop + and Hop - dynamic intestinal model was developed. In parallel, Hop + and Hop - human microbiota-associated rats were developed, germ-free (GF) rats acting as negative controls. IX and then IX + E. limosum were administered in the intestinal model and to the rats, and changes in 8-PN production and exposure were assessed. After dosing IX, 80% was converted into 8-PN in the Hop + model and highest 8-PN production, plasma concentrations, and urinary and fecal excretion occurred in the Hop + rats. Administration of the bacterium triggered 8-PN production in the GF rats and increased 8-PN production in the Hop - model and Hop - rats. 8-PN excretion was similar in the feces (294.1 +/- 132.2 nmol/d) and urine (8.5 +/- 1.1 nmol/d ) of all rats (n = 18). In addition, butyrate production increased in all rats. In conclusion, intestinal microbiota determined 8-PN production and exposure after IX intake. Moreover, E. limosum administration increased 8-PN production in low producers, resulting in similar 8-PN production in all rats.

  12. Hopping diffusion across material interfaces

    NASA Astrophysics Data System (ADS)

    Deppe, J.; Wallis, R. F.; Balkanski, M.

    1993-11-01

    We generalize a one-dimensional lattice-gas model of particle diffusion across material interfaces to include a finite-width interface region, and an energy barrier at the interface. We use overvoltage measurements on InSe and dielectric loss measurements on B 2O+ 3-0.5 Li 2O-0.15 Li 2SO 4 to determine the hopping rates in the two materials. Numerical and analytical results for the particle density versus position are presented for representative values of the energy barrier and a range of hopping rates. The presence of the energy barrier is found to be a dominant factor in the problem.

  13. Circularly polarized antennas for active holographic imaging through barriers

    SciTech Connect

    McMakin, Douglas L; Severtsen, Ronald H; Lechelt, Wayne M; Prince, James M

    2011-07-26

    Circularly-polarized antennas and their methods of use for active holographic imaging through barriers. The antennas are dielectrically loaded to optimally match the dielectric constant of the barrier through which images are to be produced. The dielectric loading helps to remove barrier-front surface reflections and to couple electromagnetic energy into the barrier.

  14. Pre- and post-infection activity of fungicides in control of hop downy mildew

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optimum timing and use of fungicides for disease control are improved by an understanding of the characteristics of fungicide physical mode of action, although this information is lacking for hop downy mildew. Control of downy mildew on leaves was similar among fungicides tested when applied prevent...

  15. Long-distance island hopping without dispersal stages: transportation across major zoogeographic barriers in a Southern Ocean isopod

    NASA Astrophysics Data System (ADS)

    Leese, Florian; Agrawal, Shobhit; Held, Christoph

    2010-06-01

    Species integrity is maintained only if recurrent allelic exchange between subpopulations occurs by means of migrating specimens. Predictions of this gene flow on the basis of observed or assumed mobility of marine species have proven to be error-prone. Using one mitochondrial gene and seven microsatellite markers, we studied the genetic structure and gene flow in Septemserolis septemcarinata, a strictly benthic species lacking pelagic larvae and the ability to swim. Suitable shallow-water habitats around three remote islands (South Georgia, Bouvet, and Marion Island) are geographically disjunct, isolated by more than 2,000 km of uninhabitable deep sea (east-west) and also separated by the Polar Front (north-south), which serves as a strong demarcation line in many marine taxa. Although we did find genetic differentiation among the three island populations, our results also revealed that a scenario with recent gene flow explains our data best. A model assuming no gene flow after initial colonization of the islands performs significantly worse. The tests also favor an asymmetric gene flow pattern (west to east ≫ east to west) thus mirroring the directionality of major oceanographic currents in the area. We conclude that rare long-distance dispersal rather than vicariance or human-mediated transport must be responsible for the observed patterns. As a mechanism, we propose passive rafting on floating substrata in the Antarctic Circumpolar Current. The results demonstrate that the effectiveness of a physical barrier is not solely a function of its physical parameters but strongly depends on how organisms interact with their environment.

  16. Expression of Pseudomonas syringae type III effectors in yeast under stress conditions reveals that HopX1 attenuates activation of the high osmolarity glycerol MAP kinase pathway.

    PubMed

    Salomon, Dor; Bosis, Eran; Dar, Daniel; Nachman, Iftach; Sessa, Guido

    2012-11-01

    The Gram-negative bacterium Pseudomonas syringae pv. tomato (Pst) is the causal agent of speck disease in tomato. Pst pathogenicity depends on a type III secretion system that delivers effector proteins into host cells, where they promote disease by manipulating processes to the advantage of the pathogen. Previous studies identified seven Pst effectors that inhibit growth when expressed in yeast under normal growth conditions, suggesting that they interfere with cellular processes conserved in yeast and plants. We hypothesized that effectors also target conserved cellular processes that are required for yeast growth only under stress conditions. We therefore examined phenotypes induced by expression of Pst effectors in yeast grown in the presence of various stressors. Out of 29 effectors tested, five (HopX1, HopG1, HopT1-1, HopH1 and AvrPtoB) displayed growth inhibition phenotypes only in combination with stress conditions. Viability assays revealed that the HopX1 effector caused loss of cell viability under prolonged osmotic stress. Using transcription reporters, we found that HopX1 attenuated the activation of the high osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) pathway, which is responsible for yeast survival under osmotic stress, while other MAPK pathways were mildly affected by HopX1. Interestingly, HopX1-mediated phenotypes in yeast were dependent on the putative transglutaminase catalytic triad of the effector. This study enlarges the pool of phenotypes available for the functional analysis of Pst type III effectors in yeast, and exemplifies how analysis of phenotypes detected in yeast under stress conditions can lead to the identification of eukaryotic cellular processes affected by bacterial effectors.

  17. Classification of Scaffold Hopping Approaches

    PubMed Central

    Sun, Hongmao; Tawa, Gregory; Wallqvist, Anders

    2012-01-01

    The general goal of drug discovery is to identify novel compounds that are active against a preselected biological target with acceptable pharmacological properties defined by marketed drugs. Scaffold hopping has been widely applied by medicinal chemists to discover equipotent compounds with novel backbones that have improved properties. In this review, scaffold hopping is classified into four major categories, namely heterocycle replacements, ring opening or closure, peptidomimetics, and topology-based hopping. The structural diversity of original and final scaffolds with respect to each category will be reviewed. The advantages and limitations of small, medium, and large-step scaffold hopping will also be discussed. Software that is frequently used to facilitate different kinds of scaffold hopping methods will be summarized. PMID:22056715

  18. The hop constituent xanthohumol exhibits hepatoprotective effects and inhibits the activation of hepatic stellate cells at different levels.

    PubMed

    Weiskirchen, Ralf; Mahli, Abdo; Weiskirchen, Sabine; Hellerbrand, Claus

    2015-01-01

    Xanthohumol is the principal prenylated flavonoid of the female inflorescences of the hop plant. In recent years, various beneficial xanthohumol effects including anti-inflammatory, antioxidant, hypoglycemic activities, and anticancer effects have been revealed. This review summarizes present studies indicating that xanthohumol also inhibits several critical pathophysiological steps during the development and course of chronic liver disease, including the activation and pro-fibrogenic genotype of hepatic stellate cells. Also the various mechanism of action and molecular targets of the beneficial xanthohumol effects will be described. Furthermore, the potential use of xanthohumol or a xanthohumol-enriched hop extract as therapeutic agent to combat the progression of chronic liver disease will be discussed. It is notable that in addition to its hepatoprotective effects, xanthohumol also holds promise as a therapeutic agent for treating obesity, dysregulation of glucose metabolism and other components of the metabolic syndrome including hepatic steatosis. Thus, therapeutic xanthohumol application appears as a promising strategy, particularly in obese patients, to inhibit the development as well as the progression of non-alcoholic fatty liver disease.

  19. The hop constituent xanthohumol exhibits hepatoprotective effects and inhibits the activation of hepatic stellate cells at different levels

    PubMed Central

    Weiskirchen, Ralf; Mahli, Abdo; Weiskirchen, Sabine; Hellerbrand, Claus

    2015-01-01

    Xanthohumol is the principal prenylated flavonoid of the female inflorescences of the hop plant. In recent years, various beneficial xanthohumol effects including anti-inflammatory, antioxidant, hypoglycemic activities, and anticancer effects have been revealed. This review summarizes present studies indicating that xanthohumol also inhibits several critical pathophysiological steps during the development and course of chronic liver disease, including the activation and pro-fibrogenic genotype of hepatic stellate cells. Also the various mechanism of action and molecular targets of the beneficial xanthohumol effects will be described. Furthermore, the potential use of xanthohumol or a xanthohumol-enriched hop extract as therapeutic agent to combat the progression of chronic liver disease will be discussed. It is notable that in addition to its hepatoprotective effects, xanthohumol also holds promise as a therapeutic agent for treating obesity, dysregulation of glucose metabolism and other components of the metabolic syndrome including hepatic steatosis. Thus, therapeutic xanthohumol application appears as a promising strategy, particularly in obese patients, to inhibit the development as well as the progression of non-alcoholic fatty liver disease. PMID:25999863

  20. Biomechanical differences between incline and plane hopping.

    PubMed

    Kannas, Theodoros M; Kellis, Eleftherios; Amiridis, Ioannis G

    2011-12-01

    Kannas, TM, Kellis, E, and Amiridis, IG. Biomechanical differences between incline and plane hopping. J Strength Cond Res 25(12): 3334-3341, 2011-The need for the generation of higher joint power output during performance of dynamic activities led us to investigate the force-length relationship of the plantar flexors during consecutive stretch-shortening cycles of hopping. The hypothesis of this study was that hopping (consecutive jumps with the knee as straight as possible) on an inclined (15°) surface might lead to a better jumping performance compared with hopping on a plane surface (0°). Twelve active men performed 3 sets of 10 consecutive hops on both an incline and plane surface. Ground reaction forces; ankle and knee joint kinematics; electromyographic (EMG) activity from the medial gastrocnemius (MG), soleus (Sol) and tibialis anterior (TA); and architectural data from the MG were recorded. The results showed that participants jumped significantly higher (p < 0.05) when hopping on an inclined surface (30.32 ± 8.18 cm) compared with hopping on a plane surface (27.52 ± 4.97 cm). No differences in temporal characteristics between the 2 types of jumps were observed. Incline hopping induced significantly greater ankle dorsiflexion and knee extension at takeoff compared with plane hopping (p < 0.05). The fascicle length of the MG was greater at initial contact with the ground during incline hopping (p < 0.05). Moreover, the EMG activities of Sol and TA during the propulsion phase were significantly higher during incline compared with that during plane hopping (p < 0.05). It does not seem unreasonable to suggest that, if the aim of hopping plyometrics is to improve plantar flexor explosivity, incline hopping might be a more effective exercise than hopping on a plane surface.

  1. Promoting Physical Activity: Addressing Barriers and Moving Forward

    ERIC Educational Resources Information Center

    Beighle, Aaron; Morrow, James R.

    2014-01-01

    The barriers that keep individuals from adopting and maintaining active lifestyles are very complex. Strategies for overcoming these barriers and to incentivize and assist inactive individuals to benefit from physical activity are necessary. In addition, it is important to examine the impact of public policy on active living. As youth physical…

  2. Perceived barriers to physical activity in university students.

    PubMed

    Arzu, Daskapan; Tuzun, Emine Handan; Eker, Levent

    2006-01-01

    Many studies which were published in other countries identified certain benefits and barriers to physical activity among young people. But there is no data about the subject pertaining to Turkish adolescents. This study tries to rectify this with a study of Turkish university students. Undergraduate university students (n = 303) were recruited to the study. Current exercise habits and perceived barriers to physical activity were assessed in the sample. Using a Likert Type scale, participants responded an instrument with 12 items representing barriers to physical activity. Mean scores were computed. External barriers were more important than internal barriers. "Lack of time due to busy lesson schedule", "My parents give academic success priority over exercise. "and "lack of time due to responsibilities related to the family and social environment "were most cited items for physical activity barriers. There is a need for future research, which will be carried out with larger sample groups to develop national standardized instrument. It will be helpful for accurately identify perceived barriers and then recommend changes to enhance physical activity among young people. Key PointsThe purpose of this study was to analyze perceived barriers to physical activity in the university students.The results showed that not having enough time was the most important barrier for not participating in physical activity among our samples.This study with relatively small sample must be considered as pilot study for related studies in the future.

  3. Comparison of odor-active compounds in the spicy fraction of hop (Humulus lupulus L.) essential oil from four different varieties.

    PubMed

    Eyres, Graham T; Marriott, Philip J; Dufour, Jean-Pierre

    2007-07-25

    The "spicy" character of hops is considered to be a desirable attribute in beer, associated with "noble hop aroma". However, the compounds responsible have yet to be adequately identified. Odorants in four samples of the spicy fraction of hop essential oil were characterized using gas chromatography-olfactometry (GC-O) and CharmAnalysis. Four hop varieties were compared, namely, Target, Saaz, Hallertauer Hersbrucker, and Cascade. Odor-active compounds were tentatively identified using comprehensive two-dimensional gas chromatography (GCxGC) combined with time-of-flight mass spectrometry (TOFMS). An intense "woody, cedarwood" odor was determined to be the most potent odorant in three of the four spicy fraction samples. This odor coincided with a complex region where between 8 and 13 compounds were coeluting in each of the four spicy fractions. The peak responsible was determined by (i) correlating peak areas with Charm values in eight hop samples and (ii) heart-cut multidimensional gas chromatography-olfactometry (MDGC-O). The compound responsible was tentatively identified as 14-hydroxy-beta-caryophyllene. Other important odorants identified were geraniol, linalool, beta-ionone, and eugenol.

  4. A novel approach for identification of biologically active phenolic compounds in complex matrices using hybrid quadrupole-orbitrap mass spectrometer: A promising tool for testing antimicrobial activity of hops.

    PubMed

    Dušek, Martin; Jandovská, Vladimíra; Čermák, Pavel; Mikyška, Alexandr; Olšovská, Jana

    2016-08-15

    The phenolic compounds, secondary metabolites of hops represent a large family of compounds that could be subsequently divided into smaller groups based on the similarities between their chemical structures. The antibacterial, antifungal and antiviral properties of hops are well known, but there is a lack of information about antimicrobial activities of individual hop compounds. This study was carried out with an objective to identify compounds present in hops that have potential antibacterial activity. In the first stage of experiment, the active compounds with potential anti-microbial activity had to be extracted from hop cones. Therefore, minced hop cones were applied on solid growth medium inoculated with Staphylococcus aureus. The active substances that migrated into the medium created an inhibition zone. In the second stage of experiment, the inhibition zones were cut out from Petri dishes, active compounds were extracted from these zones and consequently analyzed using LC-HRMS. These complex assays were developed and optimized. The data were acquired by using a quadrupole-orbitrap hybrid mass spectrometer by targeted-MS2 experiment in both ionization modes. The MS method has been developed as a screening method with a subsequent fragmentation of compound of interest on the base of inclusion mass list. The unknown compounds extracted from inhibition zones have been identified either by searching against a database or their structure has been elucidated on the basis of their fragmentation spectra. On the basis of this experiment the list of active compounds with potential anti-microbial activities was enhanced.

  5. Perceived Barriers to Physical Activity among Pregnant Women

    PubMed Central

    Evenson, Kelly R.; Moos, Merry-K; Carrier, Kathryn; Siega-Riz, Anna Maria

    2008-01-01

    Objective Physical activity generally declines during pregnancy, but barriers to activity during this time period are not well understood. The objective was to examine barriers to physical activity in a large cohort of pregnant women and to explore these barriers in more depth with qualitative data derived from a separate focus group study using a socioecologic framework. Method A total of 1535 pregnant women (27–30 weeks’ gestation) enrolled in the Pregnancy, Infection, and Nutrition Study were asked an open-ended question about their primary barrier to physical activity; responses were coded into categories according to the socioecologic framework. To further elucidate, 13 focus groups of a total of 58 pregnant women (20–37 weeks’ gestation) were conducted among Hispanic, African American, and White participants. Results Among the 1535 pregnant women participating in the survey, 85% reported an intrapersonal barrier to physical activity, of which almost two-thirds were health related. Only 2% of the women reported their main barrier to physical activity as interpersonal and 3% reported a neighborhood or environmental barrier. These results were supported by the focus group data, overall and by race/ethnicity and body mass index. Although women discussed barriers to physical activity at a variety of levels, the intrapersonal level was the most frequently cited and discussed factor in both studies. Conclusions Since pregnancy may trigger the development of obesity and since physical activity is recommended for healthy pregnant women, it is imperative to promote physical activity in a more relevant way. These quantitative and qualitative studies revealed many barriers to physical activity among pregnant women and some suggestions for interventions. PMID:18478322

  6. Mechanisms of the antiangiogenic activity by the hop flavonoid xanthohumol: NF-kappaB and Akt as targets.

    PubMed

    Albini, Adriana; Dell'Eva, Raffaella; Vené, Roberta; Ferrari, Nicoletta; Buhler, Donald R; Noonan, Douglas M; Fassina, Gianfranco

    2006-03-01

    Xanthohumol (XN), the principal flavonoid of the hop plant (Humulus lupulus L.) and a constituent of beer, has been suggested to have potential cancer chemopreventive activities. We have observed that most cancer chemopreventive agents show antiangiogenic properties in vitro and in vivo, a concept we termed "angioprevention." Here we show for the first time that XN can inhibit growth of a vascular tumor in vivo. Histopathology and in vivo angiogenesis assays indicated that tumor angiogenesis inhibition was involved. Further, we show the mechanisms for its inhibition of angiogenesis in vivo and related endothelial cell activities in vitro. XN repressed both the NF-kappaB and Akt pathways in endothelial cells, indicating that components of these pathways are major targets in the molecular mechanism of XN. Moreover, using in vitro analyses, we show that XN interferes with several points in the angiogenic process, including inhibition of endothelial cell invasion and migration, growth, and formation of a network of tubular-like structures. Our results suggest that XN can be added to the expanding list of antiangiogenic chemopreventive drugs whose potential in cancer prevention and therapy should be evaluated.

  7. Physical Activity and Youth with Disabilities: Barriers and Supports

    ERIC Educational Resources Information Center

    Block, Martin E.; Taliaferro, Andrea; Moran, Tom

    2013-01-01

    Physical activity and active use of leisure time is important for everyone but particularly important for youth with disabilities. Unfortunately, youth with disabilities often have a difficult time or are even excluded from participating in physical activity due to limited physical and cognitive skills, attitudinal barriers in the community, lack…

  8. International Collaboration Activities on Engineered Barrier Systems

    SciTech Connect

    Jove-Colon, Carlos F.

    2016-08-31

    The Used Fuel Disposition Campaign (UFDC) within the DOE Fuel Cycle Technologies (FCT) program has been engaging in international collaborations between repository R&D programs for high-level waste (HLW) disposal to leverage on gathered knowledge and laboratory/field data of near- and far-field processes from experiments at underground research laboratories (URL). Heater test experiments at URLs provide a unique opportunity to mimetically study the thermal effects of heat-generating nuclear waste in subsurface repository environments. Various configurations of these experiments have been carried out at various URLs according to the disposal design concepts of the hosting country repository program. The FEBEX (Full-scale Engineered Barrier Experiment in Crystalline Host Rock) project is a large-scale heater test experiment originated by the Spanish radioactive waste management agency (Empresa Nacional de Residuos Radiactivos S.A. – ENRESA) at the Grimsel Test Site (GTS) URL in Switzerland. The project was subsequently managed by CIEMAT. FEBEX-DP is a concerted effort of various international partners working on the evaluation of sensor data and characterization of samples obtained during the course of this field test and subsequent dismantling. The main purpose of these field-scale experiments is to evaluate feasibility for creation of an engineered barrier system (EBS) with a horizontal configuration according to the Spanish concept of deep geological disposal of high-level radioactive waste in crystalline rock. Another key aspect of this project is to improve the knowledge of coupled processes such as thermal-hydro-mechanical (THM) and thermal-hydro-chemical (THC) operating in the near-field environment. The focus of these is on model development and validation of predictions through model implementation in computational tools to simulate coupled THM and THC processes.

  9. Effects of lozenge containing lavender oil, extracts from hops, lemon balm and oat on electrical brain activity of volunteers.

    PubMed

    Dimpfel, W; Pischel, I; Lehnfeld, R

    2004-09-29

    Within a randomized double blind, placebo controlled trial the electrical activity of the human brain has been monitored using charge mode technology (Laplacian estimates) after exposure to a lozenge containing 4 different herbal preparations (lavender oil, extracts from hops, lemon balm and oat) or a matching placebo without any active ingredients. Sixteen healthy volunteers (8 males and 8 females) were tested within a crossover design. After baseline recording each subject sucked a lozenge and 2 hours later a second one. Recording was performed immediately after finishing the lozenge and in hourly intervals thereafter. Comparison to reference periods of 10 min eyes open and 5 min eyes closed, respectively, revealed increases in alpha 1, alpha 2 and beta 1 electrical power at the electrode positions Cz, P3, T3 and T5 which were even more pronounced after a second application two hours later. Since alpha 1 changes repeatedly have been attributed to attentional states, increases of this electrical activity must be seen as indicator of a relaxational psychophysiological state. Changes in the alpha2 frequencies have been related to working memory indicating that an increase can be seen as a correlate for attenuating this circuit. Increases of beta1 activity have been seen in the presence of anxiolytic drugs including major and minor tranquilizers. The changes as observed after the application of this herbal composition are therefore in line with the idea of having induced a state of relaxation and regeneration. This interpretation suggests that one could expect from the ingestion of this lozenge to better cope with psychological and emotional stress. The data are further proof that recording computer aided quantitative EEG is a very fruitful and promising approach in psychophysiology.

  10. Phospholipase Cε Modulates Rap1 Activity and the Endothelial Barrier

    PubMed Central

    DiStefano, Peter V.; Smrcka, Alan V.; Glading, Angela J.

    2016-01-01

    The phosphoinositide-specific phospholipase C, PLCε, is a unique signaling protein with known roles in regulating cardiac myocyte growth, astrocyte inflammatory signaling, and tumor formation. PLCε is also expressed in endothelial cells, however its role in endothelial regulation is not fully established. We show that endothelial cells of multiple origins, including human pulmonary artery (HPAEC), human umbilical vein (HUVEC), and immortalized brain microvascular (hCMEC/D3) endothelial cells, express PLCε. Knockdown of PLCε in arterial endothelial monolayers decreased the effectiveness of the endothelial barrier. Concomitantly, RhoA activity and stress fiber formation were increased. PLCε-deficient arterial endothelial cells also exhibited decreased Rap1-GTP levels, which could be restored by activation of the Rap1 GEF, Epac, to rescue the increase in monolayer leak. Reintroduction of PLCε rescued monolayer leak with both the CDC25 GEF domain and the lipase domain of PLCε required to fully activate Rap1 and to rescue endothelial barrier function. Finally, we demonstrate that the barrier promoting effects PLCε are dependent on Rap1 signaling through the Rap1 effector, KRIT1, which we have previously shown is vital for maintaining endothelial barrier stability. Thus we have described a novel role for PLCε PIP2 hydrolytic and Rap GEF activities in arterial endothelial cells, where PLCε-dependent activation of Rap1/KRIT1 signaling promotes endothelial barrier stability. PMID:27612188

  11. Phospholipase Cε Modulates Rap1 Activity and the Endothelial Barrier.

    PubMed

    DiStefano, Peter V; Smrcka, Alan V; Glading, Angela J

    2016-01-01

    The phosphoinositide-specific phospholipase C, PLCε, is a unique signaling protein with known roles in regulating cardiac myocyte growth, astrocyte inflammatory signaling, and tumor formation. PLCε is also expressed in endothelial cells, however its role in endothelial regulation is not fully established. We show that endothelial cells of multiple origins, including human pulmonary artery (HPAEC), human umbilical vein (HUVEC), and immortalized brain microvascular (hCMEC/D3) endothelial cells, express PLCε. Knockdown of PLCε in arterial endothelial monolayers decreased the effectiveness of the endothelial barrier. Concomitantly, RhoA activity and stress fiber formation were increased. PLCε-deficient arterial endothelial cells also exhibited decreased Rap1-GTP levels, which could be restored by activation of the Rap1 GEF, Epac, to rescue the increase in monolayer leak. Reintroduction of PLCε rescued monolayer leak with both the CDC25 GEF domain and the lipase domain of PLCε required to fully activate Rap1 and to rescue endothelial barrier function. Finally, we demonstrate that the barrier promoting effects PLCε are dependent on Rap1 signaling through the Rap1 effector, KRIT1, which we have previously shown is vital for maintaining endothelial barrier stability. Thus we have described a novel role for PLCε PIP2 hydrolytic and Rap GEF activities in arterial endothelial cells, where PLCε-dependent activation of Rap1/KRIT1 signaling promotes endothelial barrier stability.

  12. Effect of hop (Humulus lupulus L.) flavonoids on aromatase (estrogen synthase) activity.

    PubMed

    Monteiro, Rosário; Becker, Hans; Azevedo, Isabel; Calhau, Conceiçáo

    2006-04-19

    The aim of this work was to study the effect of the prenylflavonoids xanthohumol, isoxanthohumol, and 8-prenylnaringenin on the activity and expression of the enzyme aromatase (estrogen synthase). The effect of different kinds of beer containing these prenylflavonoids was also tested. Aromatase activity was determined by measuring the release of tritiated water during the conversion of [(3)H]androstenedione to estrone. Aromatase expression was determined by RT-PCR. This assay was carried out in choriocarcinoma-derived JAR cells. The tested prenylflavonoids were able to inhibit estrogen formation, and their IC(50) values were determined, although no effect on aromatase expression was found. Lager beer, alcohol-free beer, stout beer, and xanthohumol-rich stout beer (200 microL/mL) significantly decreased aromatase activity. In conclusion, prenylflavonoids are able to modulate aromatase activity, decreasing estrogen synthesis, with relevance for the prevention and treatment of estrogen-dependent disorders such as breast cancer.

  13. The Formation of "Hip-Hop Academicus"--How American Scholars Talk about the Academisation of Hip-Hop

    ERIC Educational Resources Information Center

    Soderman, Johan

    2013-01-01

    Social activism and education have been associated with hip-hop since it emerged in New York City 38 years ago. Therefore, it might not be surprising that universities have become interested in hip-hop. This article aims to highlight this "hip-hop academisation" and analyse the discursive mechanisms that manifest in these academisation…

  14. Classification of scaffold-hopping approaches.

    PubMed

    Sun, Hongmao; Tawa, Gregory; Wallqvist, Anders

    2012-04-01

    The general goal of drug discovery is to identify novel compounds that are active against a preselected biological target with acceptable pharmacological properties defined by marketed drugs. Scaffold hopping has been widely applied by medicinal chemists to discover equipotent compounds with novel backbones that have improved properties. In this article we classify scaffold hopping into four major categories, namely heterocycle replacements, ring opening or closure, peptidomimetics and topology-based hopping. We review the structural diversity of original and final scaffolds with respect to each category. We discuss the advantages and limitations of small, medium and large-step scaffold hopping. Finally, we summarize software that is frequently used to facilitate different kinds of scaffold-hopping methods.

  15. Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringenin.

    PubMed

    Possemiers, Sam; Heyerick, Arne; Robbens, Veerle; De Keukeleire, Denis; Verstraete, Willy

    2005-08-10

    Hop, an essential ingredient in most beers, contains a number of prenylflavonoids, among which 8-prenylnaringenin (8-PN) would be the most potent phytoestrogen currently known. Although a number of health effects are attributed to these compounds, only a few reports are available about the bioavailability of prenylflavonoids and the transformation potency of the intestinal microbial community. To test these transformations, four fecal samples were incubated with xanthohumol, isoxanthohumol (IX), and 8-PN. Upon incubation with IX, present in strong ales up to 4 mg/L, 36% was converted into 8-PN in one fecal sample and the estrogenic properties of the sample drastically increased. In an experiment with 12 fecal cultures, this conversion was observed in one-third of the samples, indicating the importance of interindividual variability in the intestinal microbial community. Eubacterium limosum was identified to be capable of this conversion (O-demethylation) of IX into 8-PN, and after strain selection, a conversion efficiency of 90% was achieved. Finally, strain supplementation to a nonconverting fecal sample led to rapid and high 8-PN production at only 1% (v/v) addition. Up to now, the concentration of 8-PN in beer was considered too low to affect human health. However, these results show that the activity of the intestinal microbial community could more than 10-fold increase the exposure concentration. Because prenylflavonoids are present in many beers with IX being the major constituent, the results raise the question whether moderate beer consumption might contribute to increased in vivo levels of 8-PN and even influence human health.

  16. Directed transport of active particles over asymmetric energy barriers.

    PubMed

    Koumakis, N; Maggi, C; Di Leonardo, R

    2014-08-21

    We theoretically and numerically investigate the transport of active colloids to target regions, delimited by asymmetric energy barriers. We show that it is possible to introduce a generalized effective temperature that is related to the local variance of particle velocities. The stationary probability distributions can be derived from a simple diffusion equation in the presence of an inhomogeneous effective temperature resulting from the action of external force fields. In particular, transition rates over asymmetric energy barriers can be unbalanced by having different effective temperatures over the two slopes of the barrier. By varying the type of active noise, we find that equal values of diffusivity and persistence time may produce strongly varied effective temperatures and thus stationary distributions.

  17. Wheeled hopping robot

    DOEpatents

    Fischer, Gary J.

    2010-08-17

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  18. Can human activities alter the drowning fate of barrier islands?

    NASA Astrophysics Data System (ADS)

    Lorenzo-Trueba, J.; Ashton, A. D.; Jin, D.; Hoagland, P.; Kite-Powell, H.

    2012-12-01

    Low-lying coastal barriers face an uncertain future over the coming century and beyond as sea levels rise, with many projections suggesting end-of-century rates of sea-level rise as high or higher than 1 cm/yr. Geologically, such rates of sea-level rise have been experienced several thousand years ago and we can use our understanding of geological processes and sedimentary evidence to help unravel the dynamics of natural barriers experiencing sea-level rise. Along many modern coastal barriers, however, anthropic change, such as beach nourishment, dune construction, and emplacement of hard structures, plays a dominant role in coastline dynamics. A fundamental question to be addressed is whether human activities intended to preserve infrastructure and beach recreation may make wholesale collapse, or 'drowning,' of barrier systems more likely. Here we present a numerical modeling tool that couples natural processes and the human responses to these changes (and the subsequent of human responses on natural processes). Recent theoretical model development suggests that barriers are intrinsically morphodynamic features, responding to sea-level rise in complex ways through the interactions of marine processes and barrier overwash. Undeveloped coastal barriers would therefore respond to an accelerated sea-level rise in complex, less predictable manners than suggested by existing long-term models. We have developed a model that examines non-equilibrium cross-shore evolution of barrier systems at decadal to centennial temporal scales, focusing on the interactions between processes of shoreface evolution and overwash deposition. Model responses demonstrate two means of barrier collapse during sea-level rise: 'height drowning', which occurs when overwash fluxes are insufficient to maintain the landward migration rate required to keep in pace with sea-level rise, and 'width drowning', which occurs when the shoreface response is insufficient to maintain the barrier geometry

  19. Measuring Perceived Benefits and Perceived Barriers for Physical Activity

    ERIC Educational Resources Information Center

    Brown, Seth A.

    2005-01-01

    Objectives: To evaluate the psychometric properties and relationship to physical activity levels of the Exercise Benefits/Barriers Scale (EBBS) among college students. Methods: A total of 398 college students completed the EBBS and a measure of self-efficacy, the Physical Exercise Self-Efficacy Scale. In addition, a subsample of 275 students also…

  20. Barriers to physical activity as moderators of intervention effects.

    PubMed

    Schoeny, Michael E; Fogg, Louis; Buchholz, Susan W; Miller, Arlene; Wilbur, JoEllen

    2017-03-01

    The impact of interventions to increase physical activity (PA) may vary as a function of participants' barriers to PA. The aim of this paper is to determine whether individual barriers (demographic, physical health, psychological health, neighborhood factors, perceived barriers to PA, social support for PA) moderate treatment effects on increases in PA. Three treatment conditions tested the relative efficacy of a group-based PA intervention alone or supplemented by either personal or automated phone calls made between group meetings. From 2010 to 2012, 284 African American women (ages 40-65) living in the Chicago, IL, area were randomized to one of the three treatment conditions. Data collection occurred at baseline as well as 24 and 48 weeks after baseline. Moderation of intervention effects by barriers to PA were tested across four outcome measures (self-reported moderate-vigorous PA, self-reported walking, accelerometer steps, and aerobic fitness) using multilevel mixed-effects analyses. Significant condition by barrier interaction effects for the accelerometer steps outcome were found for material hardships, general health, depressive symptoms, neighborhood crime rate, and perceived barriers to PA. For aerobic fitness, intervention effects were moderated by material hardships and perceived pain. Increases in the outcome variables were greater for the conditions in which group sessions were supplemented with personal and/or automated calls. Among participants with greater barriers to PA, supplementing the intervention group meetings with between-session personal and/or automated phone calls may be an effective way to strengthen intervention effects. These results may inform the use of treatment supplements in the context of adaptive interventions.

  1. Piezo activated mode tracking system for widely tunable mode-hop-free external cavity mid-IR semiconductor lasers

    NASA Technical Reports Server (NTRS)

    Wysocki, Gerard (Inventor); Tittel, Frank K. (Inventor); Curl, Robert F. (Inventor)

    2010-01-01

    A widely tunable, mode-hop-free semiconductor laser operating in the mid-IR comprises a QCL laser chip having an effective QCL cavity length, a diffraction grating defining a grating angle and an external cavity length with respect to said chip, and means for controlling the QCL cavity length, the external cavity length, and the grating angle. The laser of claim 1 wherein said chip may be tuned over a range of frequencies even in the absence of an anti-reflective coating. The diffraction grating is controllably pivotable and translatable relative to said chip and the effective QCL cavity length can be adjusted by varying the injection current to the chip. The laser can be used for high resolution spectroscopic applications and multi species trace-gas detection. Mode-hopping is avoided by controlling the effective QCL cavity length, the external cavity length, and the grating angle so as to replicate a virtual pivot point.

  2. Hop Cultivars and Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pest management decision making in hops varies among cultivars. Historically, the primary objective of hop breeding programs has been to increase the yield or characteristics associated with either bittering (high alpha-acids) or aroma (unique volatile oil profiles) cultivars. Other factors consid...

  3. Hopping Robot with Wheels

    NASA Technical Reports Server (NTRS)

    Barlow, Edward; Marzwell, Nevellie; Fuller, Sawyer; Fionni, Paolo; Tretton, Andy; Burdick, Joel; Schell, Steve

    2003-01-01

    A small prototype mobile robot is capable of (1) hopping to move rapidly or avoid obstacles and then (2) moving relatively slowly and precisely on the ground by use of wheels in the manner of previously reported exploratory robots of the "rover" type. This robot is a descendant of a more primitive hopping robot described in "Minimally Actuated Hopping Robot" (NPO- 20911), NASA Tech Briefs, Vol. 26, No. 11 (November 2002), page 50. There are many potential applications for robots with hopping and wheeled-locomotion (roving) capabilities in diverse fields of endeavor, including agriculture, search-and-rescue operations, general military operations, removal or safe detonation of land mines, inspection, law enforcement, and scientific exploration on Earth and remote planets. The combination of hopping and roving enables this robot to move rapidly over very rugged terrain, to overcome obstacles several times its height, and then to position itself precisely next to a desired target. Before a long hop, the robot aims itself in the desired hopping azimuth and at a desired takeoff angle above horizontal. The robot approaches the target through a series of hops and short driving operations utilizing the steering wheels for precise positioning.

  4. Barriers associated with reduced physical activity in COPD patients*

    PubMed Central

    Amorim, Priscila Batista; Stelmach, Rafael; Carvalho, Celso Ricardo Fernandes; Fernandes, Frederico Leon Arrabal; Carvalho-Pinto, Regina Maria; Cukier, Alberto

    2014-01-01

    OBJECTIVE: To evaluate the ability of COPD patients to perform activities of daily living (ADL); to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT), and an ADL limitation score. METHODS: In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL) scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT. RESULTS: We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5 ± 25.8 min/day vs. 105.2 ± 49.4 min/day; p < 0.001), as was the distance walked (3.9 ± 1.9 km/day vs. 6.4 ± 3.2 km/day; p < 0.001). The COPD patients also walked fewer steps/day. The most common self-reported barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results. CONCLUSIONS: Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures. PMID:25410838

  5. The prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestine.

    PubMed

    Possemiers, Sam; Bolca, Selin; Grootaert, Charlotte; Heyerick, Arne; Decroos, Karel; Dhooge, Willem; De Keukeleire, Denis; Rabot, Sylvie; Verstraete, Willy; Van de Wiele, Tom

    2006-07-01

    Hops, an essential beer ingredient, are a source of prenylflavonoids, including 8-prenylnaringenin (8-PN), one of the most potent phytoestrogens. Because 8-PN concentrations in beers are generally low, its health effects after moderate beer consumption were considered negligible. However, human intestinal microbiota may activate up to 4 mg/L isoxanthohumol (IX) in beer into 8-PN. Depending on interindividual differences in the intestinal transformation potential, this conversion could easily increase the 8-PN exposure 10-fold upon beer consumption. Here, we present a further investigation of the process both in vitro and in vivo. In vitro experiments with the dynamic SHIME model showed that hop prenylflavonoids pass unaltered through the stomach and small intestine and that activation of IX into 8-PN (up to 80% conversion) occurs only in the distal colon. In vitro incubations of 51 fecal samples from female volunteers with IX enabled us to separate the fecal microbiota into high (8 of 51), moderate (11 of 51) and slow (32 of 51) 8-PN producers, clearly illustrating an interindividual variability. Three women, selected from the respective groups, received a daily dose of 5.59 mg IX for 4 d. Intestinal IX activation and urinary 8-PN excretion were correlated (R(2) = 0.6417, P < 0.01). These data show that intestinal conversion of IX upon moderate beer consumption can lead to 8-PN exposure values that might fall within the range of human biological activity.

  6. The lunar hopping transporter

    NASA Technical Reports Server (NTRS)

    Degner, R.; Kaplan, M. H.; Manning, J.; Meetin, R.; Pasternack, S.; Peterson, S.; Seifert, H.

    1971-01-01

    Research on several aspects of lunar transport using the hopping mode is reported. Hopping exploits the weak lunar gravity, permits fuel economy because of partial recompression of propellant gas on landing, and does not require a continuous smooth surface for operation. Three questions critical to the design of a lunar hopping vehicle are addressed directly in this report: (1) the tolerance of a human pilot for repeated accelerations; (2) means for controlling vehicle attitude during ballistic flight; and (3) means of propulsion. In addition, a small scale terrestrial demonstrator built to confirm feasibility of the proposed operational mode is described, along with results of preliminary study of unmanned hoppers for moon exploration.

  7. Theory of hopping conductivity in pig insulin

    NASA Astrophysics Data System (ADS)

    Ye, Yuan-Jie; Ladik, János

    1993-08-01

    The ac conductivity for a native protein, pig insulin, was calculated in the ab initio scheme using Clementi's minimal basis set. The hopping centers and ``main residue'' of an orbital are defined. It is assumed that the hopping events of charge carriers happen among these centers of main residues. The analysis of primary hopping events shows that there might be a relationship between the distribution of the hopping centers and the biochemical activity of insulin, and that the disulfur bridges of insulin have particular relevance for the ac conduction. The formulas for calculation of the ac conductivity of proteins are given. The results show that the curve of the frequency versus ac conductivity of pig insulin lies in the range of some typical inorganic amorphous conductors and confirm that proteins if doped are amorphous conductors. Finally, the possibility of direct comparison of the theoretical results with experiments is discussed.

  8. The Idefix enhancer-blocking insulator also harbors barrier activity.

    PubMed

    Brasset, E; Hermant, C; Jensen, S; Vaury, C

    2010-01-15

    Chromatin insulators are cis-regulatory sequences participating in the regulation of gene expression. Their presence within the genome is associated with two main functions. One of them is an enhancer-blocking function that blocks enhancer-promoter communication when the insulator is located in between. The second is a boundary or barrier function that insulates independent units of transcription. This latter is observed when two insulators flanking a gene and its regulatory sequences block the regulatory influences of surrounding chromatin. Some years ago, we reported the presence of an insulator within the retrotransposon Idefix from Drosophila melanogaster. This insulator displays an enhancer-blocking activity toward an enhancer located within a second retrotransposon called ZAM. Here, we show that this insulator is not specific to the ZAM enhancer but has the capacity to interfere in the communication established between a broad range of cis-regulatory enhancer and a promoter. Furthermore, we show that, if it is placed on both sides of a transgene, this insulator acts as a barrier able to isolate the transgene from its repressive or enhancing environment. Thus, the Idefix insulator carries both an enhancer-blocking and a barrier activity. According to these properties, the Idefix insulator might prove to be a useful tool to isolate artificial transgenes from positive or negative influences from their integration sites.

  9. Frequency Hopping Transceiver Multiplexer

    DTIC Science & Technology

    1983-03-01

    8217 block number) frequency hopping, quadrature coupler, bandpass filter, coupling circuit, filter, helical resonator, matching network, PIN diode switch...which investigated the concept and feasibility of a 30MHz to 88MHz frequency hopping transceiver multiplexer. An approach which uses helical resonator...and Analysis 90 5.9.1 Helical Resonator 90 5.9.2 Shunt Capacitance Binary Bus Discussion 94 5.9.3 Resonator Design Decisions 97 5.9.4 Results and

  10. Mechanisms of Hop Inhibition Include the Transmembrane Redox Reaction▿

    PubMed Central

    Behr, Jürgen; Vogel, Rudi F.

    2010-01-01

    In this work, a novel mechanistic model of hop inhibition beyond the proton ionophore action toward (beer spoiling) bacteria was developed. Investigations were performed with model systems using cyclic voltammetry for the determination of redox processes/conditions in connection with growth challenges with hop-sensitive and -resistant Lactobacillus brevis strains in the presence of oxidants. Cyclic voltammetry identified a transmembrane redox reaction of hop compounds at low pH (common in beer) and in the presence of manganese (present in millimolar levels in lactic acid bacteria). The antibacterial action of hop compounds could be extended from the described proton ionophore activity, lowering the intracellular pH, to pronounced redox reactivity, causing cellular oxidative damage. Accordingly, a correlation between the resistance of L. brevis strains to a sole oxidant to their resistance to hop could not be expected and was not detected. However, in connection with our recent study concerning hop ionophore properties and the resistance of hop-sensitive and -tolerant L. brevis strains toward proton ionophores (J. Behr and R. F. Vogel, J. Agric. Food Chem. 57:6074-6081, 2009), we suggest that both ionophore and oxidant resistance are required for survival under hop stress conditions and confirmed this correlation according to the novel mechanistic model. In consequence, the expression of several published hop resistance mechanisms involved in manganese binding/transport and intracellular redox balance, as well as that of proteins involved in oxidative stress under “highly reducing” conditions (cf. anaerobic cultivation and “antioxidative” hop compounds in the growth medium), is now comprehensible. Accordingly, hop resistance as a multifactorial dynamic property at least implies distinct resistance levels against two different mechanisms of hop inhibition, namely, proton ionophore-induced and oxidative stress-induced mechanisms. Beyond this specific model of

  11. Beer spoilage bacteria and hop resistance.

    PubMed

    Sakamoto, Kanta; Konings, Wil N

    2003-12-31

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Megasphaera cerevisiae. They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media. Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not. In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer. Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria. They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf). Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death. The hop-resistance mechanisms in lactic acid bacteria have been investigated. HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium. Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance. To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells. Furthermore, a pmf-dependent hop transporter was recently presented. Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers. The horA-PCR method has been applied for bacterial control in breweries. Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells. However

  12. Effects of Powdery Mildew Fungicide Programs on Twospotted Spider Mite (Acari: Tetranychidae), Hop Aphid (Homoptera: Aphididae), and Their Natural Enemies in Hop Yards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twospotted spider mite, Tetranychus urticae Koch (Acari:Tetranychidae), and hop aphid, Phorodon humuli (Schrank) (Homoptera:Aphidiae), are the most important arthropod pests of hop (Humulus lupulus L.) in the Northern Hemisphere. A potential barrier for greater adoption of conservation biological c...

  13. Lateral hopping and desorption of a single CO molecule on a Cu(110) surface induced by femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Ueba, H.; Ootsuka, Y.

    2013-05-01

    Lateral hopping and desorption of a single CO molecule on a Cu(110) surface [Bartels , ScienceSCIEAS0036-807510.1126/science.1099770 305, 648 (2004)] induced by femtosecond laser pulses are studied using an indirect heat-transfer model. In addition to a direct heating of the reaction coordinate (RC) mode [frustrated translation (FT) mode for hopping and center-of-mass (CM) mode for desorption] by laser-generated hot electrons in the substrate, we consider an indirect heating of the RC mode through intermode coupling between the frustrated rotation (FR) mode and the RC mode. We calculate the transient behavior of the effective temperature of the FT and the CM modes, and of the normalized reaction yield. The experimental result of a ratio of the hopping yield along and across a row on a Cu(110) surface is nicely calculated. Although no information is available for the attempt frequency in a form of the Arrhenius equation for thermally activated reactions, it is predicted under which condition the desorption rate becomes in the same order of magnitude as the hopping rate, although the barrier height for desorption is much higher than for hopping. The present analysis highlights the role of excitation of the FR mode in reactions of a CO molecule as has been confirmed in the real-time observation [Backus , ScienceSCIEAS0036-807510.1126/science.1120693 310, 1790 (2005)].

  14. Physical activity and exercise after stoma surgery: overcoming the barriers.

    PubMed

    Russell, Sarah

    2017-03-09

    This article presents the results from a large nationwide survey completed in 2016 that investigated the physical health and wellbeing of people living with stomas in the UK. In particular, the survey looked at physical activity and exercise, general attitudes and opinions about exercise, whether or not advice about physical activity had been received and other general questions about parastomal hernia and quality of life. There were 2631 respondents making it one of the largest known surveys to date. The findings were concerning yet unsurprising, highlighting a trend toward inactivity after stoma surgery and a fear of exercise in general. People also seem to have poor knowledge about appropriate activities, with many suggesting that the fear of developing a parastomal hernia is a major barrier to activity. Unsurprisingly, those who have a stoma owing to cancer seem to fare worse, reporting even lower levels of physical activity and worse quality of life compared to those with other conditions. This indicates that people who have a combination of a cancer diagnosis and also a stoma may need more specific or additional support in the longer term. The most concerning finding, however, was that the majority of patients could not recall being given any advice about exercise or physical activity by their nurse or surgeon. While this survey presents some initial findings, it raises questions for further research and work. It also highlights a significantly neglected area in both research and support for stoma patients and the health professionals caring for them.

  15. Barriers to Leisure-Time Physical Activities in Individuals with Spinal Cord Injury.

    PubMed

    Hwang, Eric J; Groves, Mary D; Sanchez, Jacqueline N; Hudson, Cassandra E; Jao, Rachel G; Kroll, Meghan E

    2016-07-01

    This study investigated the personal, environmental, and activity barriers to leisure-time physical activities (LTPAs) among individuals with spinal cord injury (SCI). A survey instrument was administered to 85 participants with SCI. Personal barriers to LTPAs included issues involving motivation, pain, scheduling, and financial resources. Environmental barriers marked the issues regarding availability and accessibility to specialized programs, activities, and professional services. Activity barriers included limitations in equipment, training, and personal skills required by the selected activities. Significant negative correlations were found between these barriers and the levels of physical activity and satisfaction with physical activity. While working with clients with SCI, occupational therapists should identify those LTPA barriers and possible solutions in order to establish individualized action plans for enhancing participation in LTPAs.

  16. Factors Influencing the Implementation of Organized Physical Activity and Fruit and Vegetable Snacks in the HOP'N After-School Obesity Prevention Program

    ERIC Educational Resources Information Center

    Hastmann, Tanis J.; Bopp, Melissa; Fallon, Elizabeth A.; Rosenkranz, Richard R.; Dzewaltowski, David A.

    2013-01-01

    Objective: To identify barriers and facilitators for improving the after-school organized physical activity (PA) and snack quality. Methods: After-school staff (Year 1, n = 20; Year 2, n = 17) participated in qualitative, semistructured interviews about the implementation of an after-school obesity prevention intervention. Interviews were…

  17. Nanostructure of Poly(Acrylic Acid) Adsorption Layer on the Surface of Activated Carbon Obtained from Residue After Supercritical Extraction of Hops

    NASA Astrophysics Data System (ADS)

    Wiśniewska, M.; Nosal-Wiercińska, A.; Ostolska, I.; Sternik, D.; Nowicki, P.; Pietrzak, R.; Bazan-Wozniak, A.; Goncharuk, O.

    2017-01-01

    The nanostructure of poly(acrylic acid) (PAA) adsorption layer on the surface of mesoporous-activated carbon HPA obtained by physical activation of residue after supercritical extraction of hops was characterized. This characterization has been done based on the analysis of determination of adsorbed polymer amount, surface charge density, and zeta potential of solid particles (without and in the PAA presence). The SEM, thermogravimetric, FTIR, and MS techniques have allowed one to examine the solid surface morphology and specify different kinds of HPA surface groups. The effects of solution pH, as well as polymer molecular weight and concentration, were studied. The obtained results indicated that the highest adsorption on the activated carbon surface was exhibited by PAA with lower molecular weight (i.e., 2000 Da) at pH 3. Under such conditions, polymeric adsorption layer is composed of nanosized PAA coils (slightly negatively charged) which are densely packed on the positive surface of HPA. Additionally, the adsorption of polymeric macromolecules into solid pores is possible.

  18. Nanostructure of Poly(Acrylic Acid) Adsorption Layer on the Surface of Activated Carbon Obtained from Residue After Supercritical Extraction of Hops.

    PubMed

    Wiśniewska, M; Nosal-Wiercińska, A; Ostolska, I; Sternik, D; Nowicki, P; Pietrzak, R; Bazan-Wozniak, A; Goncharuk, O

    2017-12-01

    The nanostructure of poly(acrylic acid) (PAA) adsorption layer on the surface of mesoporous-activated carbon HPA obtained by physical activation of residue after supercritical extraction of hops was characterized. This characterization has been done based on the analysis of determination of adsorbed polymer amount, surface charge density, and zeta potential of solid particles (without and in the PAA presence). The SEM, thermogravimetric, FTIR, and MS techniques have allowed one to examine the solid surface morphology and specify different kinds of HPA surface groups. The effects of solution pH, as well as polymer molecular weight and concentration, were studied. The obtained results indicated that the highest adsorption on the activated carbon surface was exhibited by PAA with lower molecular weight (i.e., 2000 Da) at pH 3. Under such conditions, polymeric adsorption layer is composed of nanosized PAA coils (slightly negatively charged) which are densely packed on the positive surface of HPA. Additionally, the adsorption of polymeric macromolecules into solid pores is possible.

  19. Polarizability of the active site of cytochrome c reduces the activation barrier for electron transfer

    PubMed Central

    Dinpajooh, Mohammadhasan; Martin, Daniel R.; Matyushov, Dmitry V.

    2016-01-01

    Enzymes in biology’s energy chains operate with low energy input distributed through multiple electron transfer steps between protein active sites. The general challenge of biological design is how to lower the activation barrier without sacrificing a large negative reaction free energy. We show that this goal is achieved through a large polarizability of the active site. It is polarized by allowing a large number of excited states, which are populated quantum mechanically by electrostatic fluctuations of the protein and hydration water shells. This perspective is achieved by extensive mixed quantum mechanical/molecular dynamics simulations of the half reaction of reduction of cytochrome c. The barrier for electron transfer is consistently lowered by increasing the number of excited states included in the Hamiltonian of the active site diagonalized along the classical trajectory. We suggest that molecular polarizability, in addition to much studied electrostatics of permanent charges, is a key parameter to consider in order to understand how enzymes work. PMID:27306204

  20. The dual role of HOP2 in mammalian meiotic homologous recombination

    PubMed Central

    Pezza, Roberto J.; Voloshin, Oleg N.; Volodin, Alexander A.; Boateng, Kingsley A.; Bellani, Marina A.; Mazin, Alexander V.; Camerini-Otero, R. Daniel

    2014-01-01

    Deletion of Hop2 in mice eliminates homologous chromosome synapsis and disrupts double-strand break (DSB) repair through homologous recombination. HOP2 in vitro shows two distinctive activities: when it is incorporated into a HOP2–MND1 complex it stimulates DMC1 and RAD51 recombination activities and the purified HOP2 alone is proficient in promoting strand invasion. We observed that a fraction of Mnd1−/− spermatocytes, which express HOP2 but apparently have inactive DMC1 and RAD51 due to lack of the HOP2–MND1 complex, exhibits a high level of chromosome synapsis and that most DSBs in these spermatocytes are repaired. This suggests that DSB repair catalyzed solely by HOP2 supports homologous chromosome pairing and synapsis. In addition, we show that in vitro HOP2 promotes the co-aggregation of ssDNA with duplex DNA, binds to ssDNA leading to unstacking of the bases, and promotes the formation of a three-strand synaptic intermediate. However, HOP2 shows distinctive mechanistic signatures as a recombinase. Namely, HOP2-mediated strand exchange does not require ATP and, in contrast to DMC1, joint molecules formed by HOP2 are more sensitive to mismatches and are efficiently dissociated by RAD54. We propose that HOP2 may act as a recombinase with specific functions in meiosis. PMID:24304900

  1. Barriers Affecting Physical Activity in Rural Communities: Perceptions of Parents and Children

    ERIC Educational Resources Information Center

    McWhinney, Sharon; McDonald, Andrea; Dawkins-Moultin, Lenna; Outley, Corliss; McKyer, E. Lisako; Thomas, Audrene

    2011-01-01

    A comprehensive understanding of the barriers inhibiting physical activity among children is critical in the fight against childhood obesity. This qualitative interview study examined parents' and children's perceptions of the barriers to physical activity in rural communities of low socioeconomic status. Parents and children concurred that the…

  2. Abnormal hopping conduction in semiconducting polycrystalline graphene

    NASA Astrophysics Data System (ADS)

    Park, Jeongho; Mitchel, William C.; Elhamri, Said; Grazulis, Larry; Altfeder, Igor

    2013-07-01

    We report the observation of an abnormal carrier transport phenomenon in polycrystalline semiconducting graphene grown by solid carbon source molecular beam epitaxy. At the lowest temperatures in samples with small grain size, the conduction does not obey the two-dimensional Mott-type variable-range hopping (VRH) conduction often reported in semiconducting graphene. The hopping exponent p is found to deviate from the 1/3 value expected for Mott VRH with several samples exhibiting a p=2/5 dependence. We also show that the maximum energy difference between hopping sites is larger than the activation energy for nearest-neighbor hopping, violating the assumptions of the Mott model. The 2/5 dependence more closely agrees with the quasi-one-dimensional VRH model proposed by Fogler, Teber, and Shklovskii (FTS). In the FTS model, conduction occurs by tunneling between neighboring metallic wires. We suggest that metallic edge states and conductive grain boundaries play the role of the metallic wires in the FTS model.

  3. Hip-Hop Education Resources

    ERIC Educational Resources Information Center

    Hall, Marcella Runell

    2009-01-01

    Hip-hop music and culture are often cited as being public pedagogy, meaning the music itself has intrinsic educational value. Non-profit organizations and individual educators have graciously taken the lead in utilizing hip-hop to educate. As the academy continues to debate its effectiveness, teachers and community organizers are moving forward.…

  4. Patterns of Physical Activity among American Indian Children: An Assessment of Barriers and Support.

    ERIC Educational Resources Information Center

    Thompson, Janice L.; Davis, Sally M.; Gittelsohn, Joel; Going, Scott; Becenti, Alberta; Metcalfe, Lauve; Stone, Elaine; Harnack, Lisa; Ring, Kim

    2001-01-01

    Evaluated barriers to participation in physical activity by American Indian elementary school students. Data from interviews, observations, and surveys indicated that barriers at school included lack of facilities, equipment, and trained staff people for physical education. Weather conditions, safety concerns, and homework/chores were also…

  5. Landing Mechanics During Side Hopping and Crossover Hopping Maneuvers in Noninjured Women and Women With Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Ortiz, Alexis; Olson, Sharon; Trudelle-Jackson, Elaine; Rosario, Martin; Venegas, Heidi L.

    2011-01-01

    Objective To compare, landing mechanics and electromyographic activity of the lower extremities during side hopping and crossover hopping maneuvers, in noninjured women and women with anterior cruciate ligament (ACL) reconstruction. Design A case-control study. Setting A 3-dimensional motion analysis laboratory. Participants Twenty-eight young women (range, 21–35 years) (15 control subjects and 13 subjects with ACL reconstruction). Patients and Methods All participants performed a side-to-side hopping task that consisted of hopping single-legged 10 times consecutively from side to side across 2 lines marked 30 cm apart on 2 individual force plates. The task was designated as a side hopping when the hop was to the opposite side of the stance leg and as crossover hopping when the hop was toward the side of the stance leg. Main Outcome Measurements Peak hip-/knee-joint angles; peak knee extension/abduction joint moments; electromyographic studies of the gluteus maximus, gluteus medius, rectus femoris, and hamstring muscles; and quadriceps/hamstring co-contraction ratio were compared between the groups by means of 2 × 2 multivariate analysis of variance tests (group × maneuver). Results Noninjured women and women with ACL reconstruction exhibited similar hip-and knee-joint angles during both types of hopping. Hip-joint angles were greater during the crossover hopping in both groups, and knee-joint angles did not differ between the groups or hops. Knee-joint moments demonstrated a significant group × maneuver interaction. Greater knee extension and valgus moments were noted in the control group during crossover hopping, and greater knee abduction moments were noted in the ACL group during side hopping. Electromyographic data revealed no statistically significantly differences between the groups. Conclusions Women with ACL reconstruction exhibited the restoration of functional biomechanical movements such as hip-/knee-joint angles and lower extremity neuromuscular

  6. Identification of significant amino acids in multiple transmembrane domains of human transient receptor potential ankyrin 1 (TRPA1) for activation by eudesmol, an oxygenized sesquiterpene in hop essential oil.

    PubMed

    Ohara, Kazuaki; Fukuda, Takafumi; Okada, Hiroyuki; Kitao, Sayoko; Ishida, Yuko; Kato, Kyoko; Takahashi, Chika; Katayama, Mikio; Uchida, Kunitoshi; Tominaga, Makoto

    2015-01-30

    Transient receptor potential ankyrin 1 (TRPA1) is a calcium-permeable non-selective cation channel that is activated by various noxious or irritant substances in nature, including spicy compounds. Many TRPA1 chemical activators have been reported; however, only limited information is available regarding the amino acid residues that contribute to the activation by non-electrophilic activators, whereas activation mechanisms by electrophilic ligands have been well characterized. We used intracellular Ca(2+) measurements and whole-cell patch clamp recordings to show that eudesmol, an oxygenated sesquiterpene present at high concentrations in the essential oil of hop cultivar Hallertau Hersbrucker, could activate human TRPA1. Gradual activation of inward currents with outward rectification by eudesmol was observed in human embryonic kidney-derived 293 cells expressing human TRPA1. This activation was completely blocked by a TRPA1-specific inhibitor, HC03-0031. We identified three critical amino acid residues in human TRPA1 in putative transmembrane domains 3, 4, and 5, namely threonine at 813, tyrosine at 840, and serine at 873, for activation by β-eudesmol in a systematic mutational study. Our results revealed a new TRPA1 activator in hop essential oil and provide a novel insight into mechanisms of human TRPA1 activation by non-electrophilic chemicals.

  7. Identification of Significant Amino Acids in Multiple Transmembrane Domains of Human Transient Receptor Potential Ankyrin 1 (TRPA1) for Activation by Eudesmol, an Oxygenized Sesquiterpene in Hop Essential Oil

    PubMed Central

    Ohara, Kazuaki; Fukuda, Takafumi; Okada, Hiroyuki; Kitao, Sayoko; Ishida, Yuko; Kato, Kyoko; Takahashi, Chika; Katayama, Mikio; Uchida, Kunitoshi; Tominaga, Makoto

    2015-01-01

    Transient receptor potential ankyrin 1 (TRPA1) is a calcium-permeable non-selective cation channel that is activated by various noxious or irritant substances in nature, including spicy compounds. Many TRPA1 chemical activators have been reported; however, only limited information is available regarding the amino acid residues that contribute to the activation by non-electrophilic activators, whereas activation mechanisms by electrophilic ligands have been well characterized. We used intracellular Ca2+ measurements and whole-cell patch clamp recordings to show that eudesmol, an oxygenated sesquiterpene present at high concentrations in the essential oil of hop cultivar Hallertau Hersbrucker, could activate human TRPA1. Gradual activation of inward currents with outward rectification by eudesmol was observed in human embryonic kidney-derived 293 cells expressing human TRPA1. This activation was completely blocked by a TRPA1-specific inhibitor, HC03–0031. We identified three critical amino acid residues in human TRPA1 in putative transmembrane domains 3, 4, and 5, namely threonine at 813, tyrosine at 840, and serine at 873, for activation by β-eudesmol in a systematic mutational study. Our results revealed a new TRPA1 activator in hop essential oil and provide a novel insight into mechanisms of human TRPA1 activation by non-electrophilic chemicals. PMID:25525269

  8. Modeling, analysis, and validation of an active T-shaped noise barrier.

    PubMed

    Fan, Rongping; Su, Zhongqing; Cheng, Li

    2013-09-01

    With ever-increasing land traffic, abatement of traffic noise using noise barriers remains significant, yet it is a challenging task due to spatial competition with other infrastructure. In this study, a deep insight into the diffraction characteristics of acoustic fields near noise barriers of various geometries and surface conditions was achieved using numerical simulations. A T-shaped passive noise barrier with acoustically soft upper surfaces was demonstrated to outperform other candidates in a middle- or high-frequency range. Based on attributes of the acoustic field diffracted by T-shaped barriers, an active control strategy was developed to revamp the T-shaped barrier, in which a filtered minimax algorithm was established to drive the secondary sound sources. This algorithm resulted in more uniformly distributed residual sound fields than a filtered-X least mean square algorithm. Performance of the actively controlled barrier was evaluated at different positions and spacings of secondary sound sources and error sensors, leading to a series of optimal criteria for the design of active noise barriers. A prototype was fabricated and validated experimentally, manifesting particular effectiveness in insulating low-frequency noise, supplementing well the capacity of a passive T-shaped barrier which is effective in the middle- or high-frequency range.

  9. Barriers for active transport of bacteria in a microfluidic flow

    NASA Astrophysics Data System (ADS)

    Johnson, Payton; Doan, Minh; Mitchell, Kevin; Solomon, Tom

    2016-11-01

    We present experiments on the motion of swimming bacteria in a laminar, hyperbolic flow in a microfluidic cross channel. The bacteria used are a genetically-mutated "smooth swimming" bacillus subtilis. The movement of bacteria in the flow is bounded by swimming invariant manifolds (SWIMs) that act as one-way barriers. The SWIMs are similar to 'burning invariant manifolds" that act as one-way barriers that impede the motion of reaction fronts in a fluid flow. We explore the structure and bounding behavior of the SWIMs and how their separation from the passive manifolds depends on the bacteria swimming speed, normalized by the characteristic fluid speeds. Supported by NSF Grant DMR-1361881.

  10. Novel Nanocomposite Structures as Active and Passive Barrier Materials

    DTIC Science & Technology

    2010-06-01

    LaFrate, A. L.; Carlisle, T. K.; Noble, R. D.; Gin, D. L. Development of Barrier Film Materials Using Imidazolium Polymers, Poster Presented at CBD...D. L. Diol-Functionalized Imidazolium -Based Room-Temperature Ionic Liquids with Bis(trifluoromethanesulfonimide) Anions that Exhibit Variable Water...Membranes Based on Novel Diol- Imidazolium Polymers. Industrial and Engineering Chemistry Research, 2010, in press. 4 Bara, J. E.; Hatakeyama, E. S.; Gin

  11. Signaling induced by hop/STI-1 depends on endocytosis

    SciTech Connect

    Americo, Tatiana A.; Chiarini, Luciana B.; Linden, Rafael . E-mail: rlinden@biof.ufrj.br

    2007-06-29

    The co-chaperone hop/STI-1 is a ligand of the cell surface prion protein (PrP{sup C}), and their interaction leads to signaling and biological effects. Among these, hop/STI-1 induces proliferation of A172 glioblastoma cells, dependent on both PrP{sup C} and activation of the Erk pathway. We tested whether clathrin-mediated endocytosis affects signaling induced by hop/STI-1. Both hyperosmolarity induced by sucrose and monodansyl-cadaverine blocked Erk activity induced by hop/STI-1, without affecting the high basal Akt activity typical of A172. The endocytosis inhibitors also affected the sub-cellular distribution of phosphorylated Erk, consistent with blockade of the latter's activity. The data indicate that signaling induced by hop/STI-1 depends on endocytosis. These findings are consistent with a role of sub-cellular trafficking in signal transduction following engagement by PrP{sup C} by ligands such as hop/STI-1, and may help help unravel both the functions of the prion protein, as well as possible loss-of-function components of prion diseases.

  12. Barriers to participation in physical activity and exercise among middle-aged and elderly individuals.

    PubMed

    Justine, Maria; Azizan, Azliyana; Hassan, Vaharli; Salleh, Zoolfaiz; Manaf, Haidzir

    2013-10-01

    INTRODUCTION Although the benefits of physical activity and exercise are widely acknowledged, many middle-aged and elderly individuals remain sedentary. This cross-sectional study aimed to identify the external and internal barriers to physical activity and exercise participation among middle-aged and elderly individuals, as well as identify any differences in these barriers between the two groups. METHODS Recruited individuals were categorised into either the middle-aged (age 45-59 years, n = 60) or elderly (age ≥ 60 years, n = 60) group. Data on demographics, anthropometry, as well as external and internal barriers to participation in physical activity and exercise were collected. RESULTS Analysis showed no significant differences in the total scores of all internal barriers between the two groups (p > 0.05). The total scores for most external barriers between the two groups also showed no significant differences (p > 0.05); only 'cost' (p = 0.045) and 'exercise interferes with social/family activities' (p = 0.011) showed significant differences. The most common external barriers among the middle-aged and elderly respondents were 'not enough time' (46.7% vs. 48.4%), 'no one to exercise with' (40.0% vs. 28.3%) and 'lack of facilities' (33.4% vs. 35.0%). The most common internal barriers for middle-aged respondents were 'too tired' (48.3%), 'already active enough' (38.3%), 'do not know how to do it' (36.7%) and 'too lazy' (36.7%), while those for elderly respondents were 'too tired' (51.7%), 'lack of motivation' (38.4%) and 'already active enough' (38.4%). CONCLUSION Middle-aged and elderly respondents presented with similar external and internal barriers to physical activity and exercise participation. These factors should be taken into account when healthcare policies are being designed and when interventions such as the provision of facilities to promote physical activity and exercise among older people are being considered.

  13. Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beer.

    PubMed

    Milligan, S R; Kalita, J C; Heyerick, A; Rong, H; De Cooman, L; De Keukeleire, D

    1999-06-01

    The female flowers of the hop plant are used as a preservative and as a flavoring agent in beer. However, a recurring suggestion has been that hops have a powerful estrogenic activity and that beer may also be estrogenic. In this study, sensitive and specific in vitro bioassays for estrogens were used for an activity-guided fractionation of hops via selective solvent extraction and appropriate HPLC separation. We have identified a potent phytoestrogen in hops, 8-prenylnaringenin, which has an activity greater than other established plant estrogens. The estrogenic activity of this compound was reflected in its relative binding affinity to estrogen receptors from rat uteri. The presence of 8-prenylnaringenin in hops may provide an explanation for the accounts of menstrual disturbances in female hop workers. This phytoestrogen can also be detected in beer, but the levels are low and should not pose any cause for concern.

  14. Dielectric barrier plasma dynamics for active control of separated flows

    SciTech Connect

    Roy, Subrata; Singh, K.P.; Gaitonde, Datta V.

    2006-03-20

    The dynamics of separation mitigation with asymmetric dielectric barrier discharges is explored by considering the gas flow past a flat plate at an angle of attack. A self-consistent model utilizing motion of electrons, ions, and neutrals is employed to couple the electric force field to the momentum of the fluid. The charge separation and concomitant electric field yield a time-averaged body force which is oriented predominantly downstream, with a smaller transverse component towards the wall. This induces a wall-jet-like feature that effectively eliminates the separation bubble. The impact of several geometric and electrical operating parameters is elucidated.

  15. Effects of weight status and barriers on physical activity adoption among previously inactive women.

    PubMed

    Napolitano, Melissa A; Papandonatos, George D; Borradaile, Kelley E; Whiteley, Jessica A; Marcus, Bess H

    2011-11-01

    This study examined self-reported physical activity (PA) barriers, and their effects on PA behavior change at 3 and 12 months among 280 previously inactive women enrolled in a PA promotion trial. Effect modification of baseline barriers by baseline weight status on PA behavior change was also examined. At baseline and month 12, obese women reported significantly greater PA barriers compared with normal and overweight women (P < 0.05). Individual barriers that were more likely to be elevated for obese vs. normal and overweight participants at baseline were feeling too overweight, feeling self-conscious, reporting minor aches and pains, and lack of self-discipline. Also, weight status moderated the effect of PA barriers on PA behavior change from baseline to month 3 (P < 0.05), but not to month 12 (P = 0.637), with obese participants reporting high barriers achieving 70 min/week fewer than those with low barriers (P < 0.05). Finally, the interaction between barriers (high vs. low) and weight status (obese vs. normal), shows PA barriers had a detrimental PA effect among obese participants that was 122.5 min/week (95% confidence interval (CI) = 15.7, 229.4; P < 0.05) lower than their effect on normal-weight participants. These results suggest that for obese women, PA barriers have quantifiable effects on PA behavior change. This study has implications for the design of future weight loss and PA interventions, suggesting that a comprehensive assessment of PA barriers is a prerequisite for appropriate tailoring of behavioral PA interventions.

  16. "What I Wish You Knew": Social Barriers toward Physical Activity in Youth with Congenital Heart Disease (CHD)

    ERIC Educational Resources Information Center

    Moola, Fiona; Fusco, Caroline; Kirsh, Joel A.

    2011-01-01

    Despite the benefits of physical activity for youth with congenital heart disease (CHD), most patients are inactive. Although literature has addressed medical and psychological barriers to participation, little is known about the social barriers that youth encounter. This qualitative study explored sociocultural barriers to physical activity from…

  17. Hop tests correlate with IKDC and KOOS at minimum of 2 years after primary ACL reconstruction

    PubMed Central

    Reinke, Emily K.; Lorring, Dawn; Jones, Morgan H.; Schmitz, Leah; Flanigan, David C.; An, Angel Qi; Quiram, Amanda R.; Preston, Emily; Martin, Michael; Schroeder, Bettina; Parker, Richard D.; Kaeding, Christopher C.; Borzi, Lynn; Pedroza, Angela; Huston, Laura J.; Harrell, Frank E.; Dunn, Warren R.

    2012-01-01

    Purpose The hypothesis of this study was that single-legged horizontal hop test ratios would correlate with IKDC, KOOS, and Marx activity level scores in patients 2 years after primary ACL reconstruction. Methods Individual patient-reported outcome tools and hop test ratios on 69 ACL reconstructed patients were compared using correlations and multivariable modeling. Correlations between specific questions on the IKDC and KOOS concerning the ability to jump and hop ratios were also performed. Results The triple-hop ratio was moderately but significantly correlated with the IKDC, KOOS Sports and Recreation subscale, and the KOOS Knee Related Quality of Life subscale, as well as with the specific questions related to jumping. Similar but weaker relationship patterns were found for the single-hop ratio and timed hop. No significant correlations were found for the Marx activity level or crossover-hop ratio. Multivariable modeling showed almost no significant additional contribution to predictability of the IKDC or KOOS subscores by gender, BMI, or the number of faults on either leg. Conclusions The triple-hop test is most significantly correlated with patient-reported outcome scores. Multivariable modeling indicates that less than a quarter of the variability in outcome scores can be explained by hop test results. This indicates that neither test can serve as a direct proxy for the other; however, assessment of patient physical function by either direct report using validated outcome tools or by the hop test will provide relatively comparable data. Level of evidence II. PMID:21445595

  18. Barriers to Physical Activity Among African American Women: An Integrative Review of the Literature

    PubMed Central

    Joseph, Rodney P.; Ainsworth, Barbara E.; Keller, Colleen; Dodgson, Joan E

    2015-01-01

    A key aspect for researchers to consider when developing culturally appropriate physical activity (PA) interventions for African American (AA) women are the specific barriers AA women face that limit their participation in PA. Identification and critical examination of these barriers is the first step in developing comprehensive culturally relevant approaches to promote PA and help resolve PA-related health disparities in this underserved population. We conducted a systematic integrative literature review to identify barriers to PA among AA women. Five electronic databases were searched, and 42 studies (27 qualitative, 14, quantitative, 1 mixed method) published since 1990 (Range 1998–2013) in English language journals met inclusion criteria for review. Barriers were classified as intrapersonal, interpersonal, or environment/community according to their respective level of influence within our social ecological framework. Intrapersonal barriers included: lack of time, knowledge, and motivation; physical appearance concerns; health concerns; monetary cost of exercise facilities; and tiredness/fatigue. Interpersonal barriers included: family/caregiving responsibilities; lack of social support; and lack of a PA partner. Environmental barriers included: safety concerns; lack of facilities; weather concerns; lack of sidewalks; and lack of physically active AA role models. Results provide key leverage points for researchers to consider when developing culturally relevant PA interventions for AA women. PMID:25909603

  19. Barriers to Physical Activity Among African American Women: An Integrative Review of the Literature.

    PubMed

    Joseph, Rodney P; Ainsworth, Barbara E; Keller, Colleen; Dodgson, Joan E

    2015-01-01

    A key aspect for researchers to consider when developing culturally appropriate physical activity (PA) interventions for African American (AA) women are the specific barriers AA women face that limit their participation in PA. Identification and critical examination of these barriers is the first step in developing comprehensive culturally relevant approaches to promote PA and help resolve PA-related health disparities in this underserved population. We conducted a systematic integrative literature review to identify barriers to PA among AA women. Five electronic databases were searched, and forty-two studies (twenty-seven qualitative, fourteen quantitative, one mixed method) published since 1990 (range 1998-2013) in English language journals met inclusion criteria for review. Barriers were classified as intrapersonal, interpersonal, or environment/community according to their respective level of influence within our social ecological framework. Intrapersonal barriers included lack of time, knowledge, and motivation; physical appearance concerns; health concerns; monetary cost of exercise facilities; and tiredness/fatigue. Interpersonal barriers included family/caregiving responsibilities; lack of social support; and lack of a PA partner. Environmental barriers included safety concerns; lack of facilities; weather concerns; lack of sidewalks; and lack of physically active AA role models. Results provide key leverage points for researchers to consider when developing culturally relevant PA interventions for AA women.

  20. Barriers to physical activity in an on-site corporate fitness center.

    PubMed

    Schwetschenau, Heather M; O'Brien, William H; Cunningham, Christopher J L; Jex, Steve M

    2008-10-01

    Many corporations provide employees the option of participating in on-site fitness centers, but utilization rates are low. Perceived barriers to physical activity have been established as important correlates of physical activity, and recent research indicates that barriers may vary across settings. Work-site fitness centers may present unique barriers to participation, but there are currently no standardized measures that assess such barriers. Eighty-eight employees of a midwestern corporation completed a survey designed to identify and evaluate the extent to which barriers influence participation in an on-site corporate fitness center. Regression analyses revealed that external environmental barriers (e.g., inadequate exercise facilities) significantly accounted for not joining the fitness center, and for decreased duration of visits to the facility among members. Internal barriers (e.g., feeling embarrassed to exercise around coworkers) significantly accounted for frequency of fitness center visits among members. This corporate specific measure may lead to more effective interventions aimed to increase use of on-site corporate fitness centers.

  1. An Activity Theory Approach to Analyze Barriers to a Virtual Management Information Systems (MIS) Curriculum

    ERIC Educational Resources Information Center

    Jaradat, Suhair; Qablan, Ahmad; Barham, Areej

    2011-01-01

    This paper explains how the activity theory is used as a framework to analyze the barriers to a virtual Management Information Stream (MIS) Curriculum in Jordanian schools, from both the sociocultural and pedagogical perspectives. Taking the activity system as a unit of analysis, this study documents the processes by which activities shape and are…

  2. Barrier Crossing and Transport Activated by Kangaroo Fluctuations

    NASA Astrophysics Data System (ADS)

    Kostur, M.; Luczka, J.

    1999-01-01

    We study barrier crossing of Brownian particles in a bistable symmetric potential and transport of Brownian particles in spatially periodic structures, driven by both kangaroo fluctuations and thermal equilibrium noise of zero mean values. We consider exponentially and algebraically correlated kangaroo fluctuations. Starting with the full Newton--Langevin equation for the Brownian particle and by introducing scaling as well as dimensionless variables, we show that the equation is very well approximated by overdamped dynamics in which inertial effects can be neglected. We analyze properties of selected macroscopic characteristics of the system such as the mean first passage time (MFPT) of particles from one minimum of the bistable potential to the other and mean stationary velocity of particles moving in a spatially periodic potential. In dependence upon statistics of kangaroo fluctuations and temperature of the system, macroscopic characteristics exhibit distinctive non-monotonic behavior. Accordingly, there exist optimal statistics of fluctuations optimizing macroscopic characteristics.

  3. Barrier activity in Candida albicans mediates pheromone degradation and promotes mating.

    PubMed

    Schaefer, Dana; Côte, Pierre; Whiteway, Malcolm; Bennett, Richard J

    2007-06-01

    Mating in Candida albicans and Saccharomyces cerevisiae is regulated by the secretion of peptide pheromones that initiate the mating process. An important regulator of pheromone activity in S. cerevisiae is barrier activity, involving an extracellular aspartyl protease encoded by the BAR1 gene that degrades the alpha pheromone. We have characterized an equivalent barrier activity in C. albicans and demonstrate that the loss of C. albicans BAR1 activity results in opaque a cells exhibiting hypersensitivity to alpha pheromone. Hypersensitivity to pheromone is clearly seen in halo assays; in response to alpha pheromone, a lawn of C. albicans Deltabar1 mutant cells produces a marked zone in which cell growth is inhibited, whereas wild-type strains fail to show halo formation. C. albicans mutants lacking BAR1 also exhibit a striking mating defect in a cells, but not in alpha cells, due to overstimulation of the response to alpha pheromone. The block to mating occurs prior to cell fusion, as very few mating zygotes were observed in mixes of Deltabar1 a and alpha cells. Finally, in a barrier assay using a highly pheromone-sensitive strain, we were able to demonstrate that barrier activity in C. albicans is dependent on Bar1p. These studies reveal that a barrier activity to alpha pheromone exists in C. albicans and that the activity is analogous to that caused by Bar1p in S. cerevisiae.

  4. Star-Hopping

    NASA Astrophysics Data System (ADS)

    Garfinkle, Robert A.

    1997-07-01

    Introduction; Preface; Acknowledgements; 1. How to use this book and what you are going to see; 2. How the sky works, determining your field of view, observing tips and how to navigate in the night sky; 3. January - Taurus and Orion: the bull and hunter; 4. February - Canis Minor, Canis Major, and Puppis: dog days in February and Jason's Argo; 5. March - Cancer, Leo, and Corvus: a crab, the king of the beasts, and a crow; 6. April - Ursa Major: a dipper round tripper; 7. May - Coma Berenices and Virgo: the sparkling hair of Berenice and the wheat maiden and her bushel of galaxies; 8. June - Libra and Lupus: the balance scales and the wolf; 9. July - Scorpius, Sagittarius, and Scutum: the scorpion, archer, and shield of John Sobieski; 10. August - Draco: following the trail of the dragon; 11. September - Cygnus, Lyra, Vulpecula, and Sagitta: the swan, lyre, fox, and arrow; 12. October - Andromeda and Perseus: the chained lady and her rescuer; 13. November - Cepheus and Cassiopeia: the king and queen of Joppa; 14. December - Pisces, Triangulum, and Aries: of fishes, a triangle, and a ram; 15. Messier Marathon, a sundown to sunup hop across the skies; Appendix A: Classification tables; Appendix B: The constellations; Appendix C: The Greek alphabet; Appendix D: Decimalization of the day; Glossary; Bibliography; Index.

  5. Toll-like receptor 3 activation is required for normal skin barrier repair following UV damage.

    PubMed

    Borkowski, Andrew W; Kuo, I-Hsin; Bernard, Jamie J; Yoshida, Takeshi; Williams, Michael R; Hung, Nai-Jung; Yu, Benjamin D; Beck, Lisa A; Gallo, Richard L

    2015-02-01

    UV damage to the skin leads to the release of noncoding RNA (ncRNA) from necrotic keratinocytes that activates Toll-like receptor 3 (TLR3). This release of ncRNA triggers inflammation in the skin following UV damage. Recently, TLR3 activation was also shown to aid wound repair and increase the expression of genes associated with permeability barrier repair. Here, we sought to test whether skin barrier repair after UVB damage is dependent on the activation of TLR3. We observed that multiple ncRNAs induced expression of skin barrier repair genes, that the TLR3 ligand Poly (I:C) also induced expression and function of tight junctions, and that the ncRNA U1 acts in a TLR3-dependent manner to induce expression of skin barrier repair genes. These observations were shown to have functional relevance as Tlr3-/- mice displayed a delay in skin barrier repair following UVB damage. Combined, these data further validate the conclusion that recognition of endogenous RNA by TLR3 is an important step in the program of skin barrier repair.

  6. Toll-like receptor 3 activation is required for normal skin barrier repair following UV damage

    PubMed Central

    Borkowski, Andrew W.; Kuo, I-Hsin; Bernard, Jamie J.; Yoshida, Takeshi; Williams, Michael R.; Hung, Nai-Jung; Yu, Benjamin D.; Beck, Lisa A.; Gallo, Richard L.

    2014-01-01

    Ultraviolet (UV) damage to the skin leads to the release of noncoding RNA (ncRNA) from necrotic keratinocytes that activates toll-like receptor 3 (TLR3). This release of ncRNA triggers inflammation in the skin following UV damage. Recently, TLR3 activation was also shown to aid wound repair and increase expression of genes associated with permeability barrier repair. Here, we sought to test if skin barrier repair after UVB damage is dependent on the activation of TLR3. We observed that multiple ncRNAs induced expression of skin barrier repair genes, that the TLR3 ligand Poly (I:C) also induced expression and function of tight junctions, and that the ncRNA U1 acts in a TLR3-dependent manner to induce expression of skin barrier repair genes. These observations were shown to have functional relevance as Tlr3−/− mice displayed a delay in skin barrier repair following UVB damage. Combined, these data further validate the conclusion that recognition of endogenous RNA by TLR3 is an important step in the program of skin barrier repair. PMID:25118157

  7. Noise Induces Hopping between NF-κB Entrainment Modes.

    PubMed

    Heltberg, Mathias; Kellogg, Ryan A; Krishna, Sandeep; Tay, Savaş; Jensen, Mogens H

    2016-12-21

    Oscillations and noise drive many processes in biology, but how both affect the activity of the transcription factor nuclear factor κB (NF-κB) is not understood. Here, we observe that when NF-κB oscillations are entrained by periodic tumor necrosis factor (TNF) inputs in experiments, NF-κB exhibits jumps between frequency modes, a phenomenon we call "cellular mode-hopping." By comparing stochastic simulations of NF-κB oscillations to deterministic simulations conducted inside and outside the chaotic regime of parameter space, we show that noise facilitates mode-hopping in all regimes. However, when the deterministic system is driven by chaotic dynamics, hops between modes are erratic and short-lived, whereas in experiments, the system spends several periods in one entrainment mode before hopping and rarely visits more than two modes. The experimental behavior matches our simulations of noise-induced mode-hopping outside the chaotic regime. We suggest that mode-hopping is a mechanism by which different NF-κB-dependent genes under frequency control can be expressed at different times.

  8. Extreme Kinematics in Selected Hip Hop Dance Sequences.

    PubMed

    Bronner, Shaw; Ojofeitimi, Sheyi; Woo, Helen

    2015-09-01

    Hip hop dance has many styles including breakdance (breaking), house, popping and locking, funk, streetdance, krumping, Memphis jookin', and voguing. These movements combine the complexity of dance choreography with the challenges of gymnastics and acrobatic movements. Despite high injury rates in hip hop dance, particularly in breakdance, to date there are no published biomechanical studies in this population. The purpose of this study was to compare representative hip hop steps found in breakdance (toprock and breaking) and house and provide descriptive statistics of the angular displacements that occurred in these sequences. Six expert female hip hop dancers performed three choreographed dance sequences, top rock, breaking, and house, to standardized music-based tempos. Hip, knee, and ankle kinematics were collected during sequences that were 18 to 30 sec long. Hip, knee, and ankle three-dimensional peak joint angles were compared in repeated measures ANOVAs with post hoc tests where appropriate (p<0.01). Peak angles of the breaking sequence, which included floorwork, exceeded the other two sequences in the majority of planes and joints. Hip hop maximal joint angles exceeded reported activities of daily living and high injury sports such as gymnastics. Hip hop dancers work at weight-bearing joint end ranges where muscles are at a functional disadvantage. These results may explain why lower extremity injury rates are high in this population.

  9. Barrier-protective effects of activated protein C in human alveolar epithelial cells.

    PubMed

    Puig, Ferranda; Fuster, Gemma; Adda, Mélanie; Blanch, Lluís; Farre, Ramon; Navajas, Daniel; Artigas, Antonio

    2013-01-01

    Acute lung injury (ALI) is a clinical manifestation of respiratory failure, caused by lung inflammation and the disruption of the alveolar-capillary barrier. Preservation of the physical integrity of the alveolar epithelial monolayer is of critical importance to prevent alveolar edema. Barrier integrity depends largely on the balance between physical forces on cell-cell and cell-matrix contacts, and this balance might be affected by alterations in the coagulation cascade in patients with ALI. We aimed to study the effects of activated protein C (APC) on mechanical tension and barrier integrity in human alveolar epithelial cells (A549) exposed to thrombin. Cells were pretreated for 3 h with APC (50 µg/ml) or vehicle (control). Subsequently, thrombin (50 nM) or medium was added to the cell culture. APC significantly reduced thrombin-induced cell monolayer permeability, cell stiffening, and cell contraction, measured by electrical impedance, optical magnetic twisting cytometry, and traction microscopy, respectively, suggesting a barrier-protective response. The dynamics of the barrier integrity was also assessed by western blotting and immunofluorescence analysis of the tight junction ZO-1. Thrombin resulted in more elongated ZO-1 aggregates at cell-cell interface areas and induced an increase in ZO-1 membrane protein content. APC attenuated the length of these ZO-1 aggregates and reduced the ZO-1 membrane protein levels induced by thrombin. In conclusion, pretreatment with APC reduced the disruption of barrier integrity induced by thrombin, thus contributing to alveolar epithelial barrier protection.

  10. Gender Differences in Barriers to Physical Activity among College Students Reporting Varying Levels of Regular Physical Activity

    ERIC Educational Resources Information Center

    Munford, Shawn N.

    2011-01-01

    Researchers have studied the primary determinants of physical activity in an effort to enhance health promotion initiatives nationwide. These physical activity determinants have been observed to differ among various segments of the population, suggesting a further examination of physical activity barriers among differing populations. Little…

  11. Activated Protein C Enhances Human Keratinocyte Barrier Integrity via Sequential Activation of Epidermal Growth Factor Receptor and Tie2*

    PubMed Central

    Xue, Meilang; Chow, Shu-Oi; Dervish, Suat; Chan, Yee-Ka Agnes; Julovi, Sohel M.; Jackson, Christopher J.

    2011-01-01

    Keratinocytes play a critical role in maintaining epidermal barrier function. Activated protein C (APC), a natural anticoagulant with anti-inflammatory and endothelial barrier protective properties, significantly increased the barrier impedance of keratinocyte monolayers, measured by electric cell substrate impedance sensing and FITC-dextran flux. In response to APC, Tie2, a tyrosine kinase receptor, was rapidly activated within 30 min, and relocated to cell-cell contacts. APC also increased junction proteins zona occludens, claudin-1 and VE-cadherin. Inhibition of Tie2 by its peptide inhibitor or small interfering RNA abolished the barrier protective effect of APC. Interestingly, APC did not activate Tie2 through its major ligand, angiopoietin-1, but instead acted by binding to endothelial protein C receptor, cleaving protease-activated receptor-1 and transactivating EGF receptor. Furthermore, when activation of Akt, but not ERK, was inhibited, the barrier protective effect of APC on keratinocytes was abolished. Thus, APC activates Tie2, via a mechanism requiring, in sequential order, the receptors, endothelial protein C receptor, protease-activated receptor-1, and EGF receptor, which selectively enhances the PI3K/Akt signaling to enhance junctional complexes and reduce keratinocyte permeability. PMID:21173154

  12. Motives for and barriers to physical activity in twin pairs discordant for leisure time physical activity for 30 years.

    PubMed

    Aaltonen, S; Leskinen, T; Morris, T; Alen, M; Kaprio, J; Liukkonen, J; Kujala, U

    2012-02-01

    Long-term persistent physical activity is important in the prevention of chronic diseases, but a large number of people do not participate in physical activity to obtain health benefits. The purpose of this study was to examine the motives and perceived barriers to long-term engagement in leisure time physical activity. Same-sex twin pairs (N=16, mean age 60) discordant for physical activity over 30 years were identified from the Finnish Twin Cohort. We evaluated participants' physical activity motivation with the 73-item Recreational Exercise Motivation Measure and assessed barriers to physical activity with a 25-item questionnaire. The characteristics of physical activity motivation and perceived barriers between the active and inactive co-twins were analysed using paired tests. Motives related to the sub-dimensions of enjoyment and physical fitness and psychological state were the most important reasons for participation in physical activity among all the twin individuals analysed. The sub-dimensions mastery (p=0.018, Cohen's d=0.76), physical fitness (p=0.029, Cohen's d=0.69), and psychological state (p=0.039, Cohen's d=0.65) differed significantly between active and inactive co-twins. More than half of the participants reported no reasons for not being physically active. If reasons existed, participation in physical activity was deterred mostly by pain and various health problems. This study found no differences in perceived barriers between active and inactive co-twins. We conclude from our results that the main factors promoting persistent leisure time physical activity were participants' wish to improve or maintain their physical skills or techniques, a feeling that exercise would improve their mental and physical health and that they found the activity enjoyable. This study helps us understand the importance of the role of motives and the minor role of perceived barriers for engagement in persistent physical activity.

  13. Midlife Women's Negotiations of Barriers to and Facilitators of Physical Activity: Implications for Counselors

    ERIC Educational Resources Information Center

    Hendry, Petra; Solmon, Melinda; Choate, Laura H.; Autrey, Pam; Landry, Joan B.

    2010-01-01

    The authors investigated barriers to exercise and facilitators that enable midlife women to engage in an active lifestyle. Findings provide counselors with insight into the meanings that women ascribe to physical activity so they can better assist clients in making choices that enhance their overall health and wellness.

  14. Identifying Facilitators and Barriers to Physical Activity for Adults with Down Syndrome

    ERIC Educational Resources Information Center

    Mahy, J.; Shields, N.; Taylor, N. F.; Dodd, K. J.

    2010-01-01

    Background: Adults with Down syndrome are typically sedentary, and many do not participate in the recommended levels of physical activity per week. The aim of this study was to identify the facilitators and barriers to physical activity for this group. Method: Semi-structured interviews were conducted to elicit the views of adults with Down…

  15. Do Perceived Cues, Benefits, and Barriers to Physical Activity Differ between Male and Female Adolescents?

    ERIC Educational Resources Information Center

    Tergerson, Jennifer L.; King, Keith A.

    2002-01-01

    Surveyed adolescents at single-sex high schools to examine whether perceptions of physical activity differed by gender. The most helpful cue to physical activity for males and females was having a friend to exercise with. Parental encouragement and having a parent who exercised were also helpful. Wanting to do other things was a common barrier to…

  16. Identifying the Barriers and Facilitators to Participation in Physical Activity for Children with Down Syndrome

    ERIC Educational Resources Information Center

    Barr, M.; Shields, N.

    2011-01-01

    Background: Many children with Down syndrome do not undertake the recommended amount of daily physical activity. The aim of this study was to explore the barriers and facilitators to physical activity for this group. Methods: Eighteen in-depth interviews were conducted with 20 parents (16 mothers, 4 fathers) of children with Down syndrome aged…

  17. Barriers to Physical Activity for People with Long-Term Neurological Conditions: A Review Study

    ERIC Educational Resources Information Center

    Mulligan, Hilda F.; Hale, Leigh A.; Whitehead, Lisa; Baxter, G. David

    2012-01-01

    People with disability are insufficiently physically active for health. This study identified the volume, quality, and findings of research that exposes environmental and personal barriers of physical activity participation for people with neurological conditions. CINAHL, Sport Discus, EMBASE, Medline, and AMED were systematically searched between…

  18. Levels of Engagement and Barriers to Physical Activity in a Population of Adults with Learning Disabilities

    ERIC Educational Resources Information Center

    Hawkins, Andrew; Look, Roger

    2006-01-01

    This study examined levels of, and barriers to, physical activity in a population of 19 adults with learning disabilities living in community supported accommodation, using diary records and semi-structured interviews with staff. The levels of physical activity were higher in the sample population than previous figures for adults with learning…

  19. Barriers and Facilitators of Breastfeeding for Primiparous Active Duty Military Mothers: A Qualitative Study

    DTIC Science & Technology

    1999-05-11

    allowing more rapid involution of the uterus and decreased postpartum bleeding. Amenorrhea caused by breastfeeding results in less menstrual blood loss in...BARRIERS AND FACILITATORS OF BREASTFEEDING FOR PRIMIPAROUS ACTIVE DUTY MILITARY MOTHERS: A QUALITATIVE STUDY Kristine Markley Bristow APPROVED... BREASTFEEDING FOR PRIMIPAROUS ACTIVE DUTY MILITARY MOTHERS: A QUALITATIVE STUDY” beyond brief excerpts is with the permission of the copyright owner, and

  20. Barriers and Facilitators of Breasteeding for Primiparous Active Duty Military Mothers: A Qualitative Study

    DTIC Science & Technology

    1999-05-01

    Breastfeeding increases oxytocin levels, allowing more rapid involution of the uterus and decreased postpartum bleeding. Amenorrhea caused by breastfeeding ...BARRIERS AND FACILITATORS OF BREASTFEEDING FOR PRIMIPAROUS ACTIVE DUTY MILITARY MOTHERS: A QUALITATIVE STUDY Kristine Markley Bristow APPROVED...FACILITATORS OF BREASTFEEDING FOR PRIMIPAROUS ACTIVE DUTY MILITARY MOTHERS: A QUALITATIVE STUDY 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  1. Barriers to Research Activities from the Perspective of the Students of Isfahan University of Medical Sciences

    PubMed Central

    Ashrafi-rizi, Hasan; Fateme, Zarmehr; Khorasgani, Zahra Ghazavi; Kazempour, Zahra; Imani, Sona Taebi

    2015-01-01

    Introduction: Necessity to establish a coherent and targeted research context in order to development of any country is increasingly important. But the basic step in creating an effective research context would be enrichment motivation of researchers especially students and resolve barriers of research. Therefore, the purpose of this study was to determine barriers of research activities from the perspective of students of Isfahan University of Medical Sciences. Methods: This is research. Data was collected with author made questionnaire. The study sample consisted of students from Isfahan medical university and sample size based on Krejcie and Morgan table was 357. Sampling was Stratified Random. The validity of questionnaire confirmed by Library and information professionals and reliability based on Cronbach’s Alpha was 0.933, respectively. The type of descriptive statistics was (percentage, frequency and mean) and inferential statistics (T-test, ANOVA, one-Sample Statistics) and SPSS software was used. Findings: Results showed that the mean of barriers to research activities among students of Isfahan University of Medical Sciences was 3.89 ± 0. 483. The highest mean was related to density of students’ curriculum (4.22± 0.968) and lowest mean related to lack of access to appropriate library resources. Also, the mean of research activities ’s barriers, according to aspects showed that the mean in individual barriers level (4.06±0.635) was more than other aspects: social and cultural aspects (4.01± 0.661), economical aspect (4.04± 0.787) and organizational barriers (3.78±0.503). The lowest mean was related to organizational barriers. Also there is no difference between mean of research activities’ barriers of student of Isfahan University of Medical Sciences with regarded of gender, level of education and college. Conclusion: According to results of this research, although, the main barriers between students was individual barriers such as: lack of

  2. Psychometric assessment of the Adolescent Physical Activity Perceived Benefits and Barriers Scales.

    PubMed

    Robbins, Lorraine B; Wu, Tsu-Yin; Sikorskii, Alla; Morley, Blair

    2008-01-01

    The purpose of this study was to psychometrically test the Adolescent Physical Activity Perceived Benefits and Barriers Scales developed for middle-school-age youth. A total of 206 racially diverse 6th, 7th, and 8th graders completed questionnaires at two time points (2 weeks apart). For the 10-item Perceived Benefits Scale and the 9-item Perceived Barriers Scale, test-retest reliability (r = .70; r = .71, respectively) and internal consistency (Cronbach's alpha was .80 and .79, respectively, at time 1) were supported. Principal components analysis with Varimax rotation was employed to assess construct validity. A 2-factor solution emerged for each scale as predicted. The relationship between both scale scores and self-reported physical activity provided additional evidence of validity. Both instruments were found to be reliable and valid for measuring the perceived benefits of and barriers to physical activity in middle school youth.

  3. Fast proton hopping detection in ice I{sub h} by quasi-elastic neutron scattering.

    SciTech Connect

    Presiado, I.; Lal, J.; Mamontov, E.; Kolesnikov, A. I.; Huppert, D.

    2011-01-01

    Quasi-elastic neutron scattering was employed on samples of HCl-doped polycrystalline ice I{sub h}. The analysis of the scattering signal provides the excess proton hopping time, {tau}{sub hop}, in the temperature range of 140-195 K. The hopping time strongly depends on the temperature of the sample, and the activation energy of a hopping step is 17 kJ/mol. The values of {tau}{sub hop} of the current experiment are in good agreement with calculated values derived from previous photochemical experiments, in which we found that the proton hopping time at T > 242 K is on the order of 200 fs, roughly 10 times shorter than in liquid water at room temperature.

  4. Fast Proton Hopping Detection in Ice Ih by Quasi-Elastic Neutron Scattering

    SciTech Connect

    Presiado, Itay; Lal, Jyotsana; Mamontov, Eugene; Kolesnikov, Alexander I; Huppert, Dan I

    2011-01-01

    Quasi-elastic neutron scattering was employed on samples of HCl-doped polycrystalline ice I{sub h}. The analysis of the scattering signal provides the excess proton hopping time, {tau}{sub hop}, in the temperature range of 140-195 K. The hopping time strongly depends on the temperature of the sample, and the activation energy of a hopping step is 17 kJ/mol. The values of {tau}{sub hop} of the current experiment are in good agreement with calculated values derived from previous photochemical experiments,(1) in which we found that the proton hopping time at T > 242 K is on the order of 200 fs, roughly 10 times shorter than in liquid water at room temperature.

  5. Hip Hop Dance Experience Linked to Sociocognitive Ability.

    PubMed

    Bonny, Justin W; Lindberg, Jenna C; Pacampara, Marc C

    2017-01-01

    Expertise within gaming (e.g., chess, video games) and kinesthetic (e.g., sports, classical dance) activities has been found to be linked with specific cognitive skills. Some of these skills, working memory, mental rotation, problem solving, are linked to higher performance in science, technology, math, and engineering (STEM) disciplines. In the present study, we examined whether experience in a different activity, hip hop dance, is also linked to cognitive abilities connected with STEM skills as well as social cognition ability. Dancers who varied in hip hop and other dance style experience were presented with a set of computerized tasks that assessed working memory capacity, mental rotation speed, problem solving efficiency, and theory of mind. We found that, when controlling for demographic factors and other dance style experience, those with greater hip hop dance experience were faster at mentally rotating images of hands at greater angle disparities and there was a trend for greater accuracy at identifying positive emotions displayed by cropped images of human faces. We suggest that hip hop dance, similar to other more technical activities such as video gameplay, tap some specific cognitive abilities that underlie STEM skills. Furthermore, we suggest that hip hop dance experience can be used to reach populations who may not otherwise be interested in other kinesthetic or gaming activities and potentially enhance select sociocognitive skills.

  6. Hip Hop Dance Experience Linked to Sociocognitive Ability

    PubMed Central

    Bonny, Justin W.; Lindberg, Jenna C.; Pacampara, Marc C.

    2017-01-01

    Expertise within gaming (e.g., chess, video games) and kinesthetic (e.g., sports, classical dance) activities has been found to be linked with specific cognitive skills. Some of these skills, working memory, mental rotation, problem solving, are linked to higher performance in science, technology, math, and engineering (STEM) disciplines. In the present study, we examined whether experience in a different activity, hip hop dance, is also linked to cognitive abilities connected with STEM skills as well as social cognition ability. Dancers who varied in hip hop and other dance style experience were presented with a set of computerized tasks that assessed working memory capacity, mental rotation speed, problem solving efficiency, and theory of mind. We found that, when controlling for demographic factors and other dance style experience, those with greater hip hop dance experience were faster at mentally rotating images of hands at greater angle disparities and there was a trend for greater accuracy at identifying positive emotions displayed by cropped images of human faces. We suggest that hip hop dance, similar to other more technical activities such as video gameplay, tap some specific cognitive abilities that underlie STEM skills. Furthermore, we suggest that hip hop dance experience can be used to reach populations who may not otherwise be interested in other kinesthetic or gaming activities and potentially enhance select sociocognitive skills. PMID:28146562

  7. Removing the barrier to the calculation of activation energies

    SciTech Connect

    Mesele, Oluwaseun O.; Thompson, Ward H.

    2016-10-06

    Approaches for directly calculating the activation energy for a chemical reaction from a simulation at a single temperature are explored with applications to both classical and quantum systems. The activation energy is obtained from a time correlation function that can be evaluated from the same molecular dynamics trajectories or quantum dynamics used to evaluate the rate constant itself and thus requires essentially no extra computational work.

  8. Hop (Humulus lupulus)-derived bitter acids as multipotent bioactive compounds.

    PubMed

    Van Cleemput, Marjan; Cattoor, Ko; De Bosscher, Karolien; Haegeman, Guy; De Keukeleire, Denis; Heyerick, Arne

    2009-06-01

    Hop acids, a family of bitter compounds derived from the hop plant (Humulus lupulus), have been reported to exert a wide range of effects, both in vitro and in vivo. They exhibit potential anticancer activity by inhibiting cell proliferation and angiogenesis, by inducing apoptosis, and by increasing the expression of cytochrome P450 detoxification enzymes. Furthermore, hop bitter acids are effective against inflammatory and metabolic disorders, which makes them challenging candidates for the treatment of diabetes mellitus, cardiovascular diseases, and metabolic syndrome. This review summarizes the current knowledge on hop bitter acids, including both phytochemical aspects, as well as the biological and pharmacological properties of these compounds.

  9. Physical activity barriers and enablers in older Veterans with lower-limb amputation.

    PubMed

    Littman, Alyson J; Boyko, Edward J; Thompson, Mary Lou; Haselkorn, Jodie K; Sangeorzan, Bruce J; Arterburn, David E

    2014-01-01

    Little is known about the types of physical activities that older individuals with lower-limb loss perform, correlates of regular physical activity (PA), and barriers and facilitators to PA. We conducted an exploratory study in 158 older Veterans from the Pacific Northwest with a partial foot (35%), below-knee (39%) and above-knee (26%) amputation. Ninety-eight percent of survey respondents were male, on average 65 yr of age and 15 yr postamputation; 36% of amputations were trauma-related. The most commonly reported physical activities were muscle strengthening (42%), yard work and/or gardening (30%), and bicycling (11%). Forty-three percent were classified as physically active based on weekly moderate- and vigorous-intensity PA. History of vigorous preamputation PA was positively associated with being active, while low wealth and watching ≥5 h/d of television/videos were inversely associated. While pain- and resource-related barriers to PA were most frequently reported, only knowledge-related and interest/motivation-related barriers were inversely associated with being active. Family support and financial assistance to join a gym were the most commonly reported factors that would facilitate PA. To increase PA in the older amputee population, interventions should address motivational issues, knowledge gaps, and television watching; reduce financial barriers to exercising; and consider involving family members.

  10. Frequency hopping millimeter wave reflectometer

    NASA Astrophysics Data System (ADS)

    Cupido, L.; Sánchez, J.; Estrada, T.

    2004-10-01

    Reflectometry techniques are employed to study density fluctuations in fusion plasmas either using one channel or two channels with slightly different frequencies, to probe simultaneously closely spaced plasma layers (for radial correlation studies). The present article describes a novel system with increasing measuring capability utilizing only one single frequency that can be hopped during the discharge. This broadband fast hopping mm-wave reflectometer (BFHR) has been developed for both ASDEX upgrade (Max Plank Institute-Garching-Germany) and TJ-II stellarator (CIEMAT-Spain). The BFHR incorporates frequency synthesizers at microwave frequencies multiplied into the millimeter-wave range and uses heterodyne detection for sensitive phase and amplitude measurements.

  11. Physical activity in hypertrophic cardiomyopathy: prevalence of inactivity and perceived barriers

    PubMed Central

    Sweeting, Joanna; Ingles, Jodie; Timperio, Anna; Patterson, Jillian; Ball, Kylie; Semsarian, Christopher

    2016-01-01

    Objectives This study aimed to determine the prevalence of physical inactivity and perceived barriers to physical activity among individuals with hypertrophic cardiomyopathy (HCM), and to determine potential demographic, clinical and health-related factors influencing likelihood of meeting physical activity guidelines. Methods This was a cross-sectional study of consecutive patients (n=198) with HCM attending a specialist HCM centre from July 2014 to November 2015. The primary outcome measure was physical activity (minutes per day), as measured by self-report (International Physical Activity Questionnaire (IPAQ)) and objective means (ActiGraph accelerometer). For both, participants were classified as meeting guidelines if they did at least 150 min per week of physical activity. Quality of life (Short Form-36 V.2, SF-36v2), barriers to exercise and clinical–demographic data were also collected. Results In total, 54.8% of participants did not meet physical activity recommendations based on IPAQ, and 12.7% did not meet guidelines based on accelerometer data. The most commonly identified barriers to exercise were ‘pain interferes with my exercise’ (33%) and ‘I have an injury/disability that stops me’ (29%). Independent factors associated with meeting guidelines included older age (OR 0.66, 95% CI 0.51 to 0.85, p=0.002), higher education level (OR 2.31, 95% CI 1.08 to 4.93, p=0.03), better physical quality of life (OR 1.05, 95% CI 1.0 to 1.09, p=0.05) and more reported barriers (OR 0.71, 95% CI 0.56 to 0.91, p=0.01). Conclusions More than half of the patients with HCM did not meet minimum physical activity recommendations. Several barriers to exercise among individuals with HCM exist, and provide the basis for targeted interventions to promote physical activity and improve overall health in patients with HCM. PMID:27547438

  12. Activated barrier for protection of special nuclear materials in vital areas

    SciTech Connect

    Timm, R.E.; Miranda, J.E.; Reigle, D.L.; Valente, A.D.

    1984-07-15

    The Argonne National Laboratory and Sandia National Laboratory have recently installed an activated barrier, the Access Denial System (ADS) for the upgrade of safeguards of special nuclear materials. The technology of this system was developed in the late 70's by Sandia National Laboratory-Albuquerque. The installation was the first for the Department of Energy. Subsequently, two additional installations have been completed. The Access Denial System, combined with physical restraints, provide the system delay. The principal advantages of the activated barrier are: (1) it provides an order of magnitude improvement in delay over that of a fixed barrier, (2) it can be added to existing vital areas with a minimum of renovations, (3) existing operations are minimally impacted, and (4) health and safety risks are virtually nonexistent. Hardening of the vital areas using the ADS was accomplished in a cost-effective manner. 3 references, 1 figure, 1 table.

  13. Regional Blood-Brain Barrier Responses to Central Cholinergic Activity

    DTIC Science & Technology

    1989-07-30

    regions were of particular interest because they show the largest decreases in glucose metabolism following limbic seizures ( Ben - Ari et al., 1981). It is...following seizures ( Ben - Ari et. al., 1981). The piriform cortex-amygdala also appears to be a generator of epileptiform activity in a variety of seizure...produced by PTZ. Such studies are ongoing and the results will be given in subsequent reports. 11 REFERENCES Ben - Ari , Y., D. Richie, E. Tremblay and G

  14. Redox-active media for permeable reactive barriers

    SciTech Connect

    Sivavec, T.M.; Mackenzie, P.D.; Horney, D.P.; Baghel, S.S.

    1997-12-31

    In this paper, three classes of redox-active media are described and evaluated in terms of their long-term effectiveness in treating TCE-contaminated groundwater in permeable reactive zones. Zero-valent iron, in the form of recycled cast iron filings, the first class, has received considerable attention as a reactive media and has been used in about a dozen pilot- and full-scale subsurface wall installations. Criteria used in selecting commercial sources of granular iron, will be discussed. Two other classes of redox-active media that have not yet seen wide use in pilot- or full-scale installations will also be described: Fe(II) minerals and bimetallic systems. Fe(II) minerals, including magnetite (Fe{sub 3}O{sub 4}), and ferrous sulfide (troilite, FeS), are redox-active and afford TCE reduction rates and product distributions that suggest that they react via a reductive mechanism similar to that which operates in the FeO system. Fe(II) species within the passive oxide layer coating the iron metal may act as electron transfer mediators, with FeO serving as the bulk reductant. Bimetallic systems, the third class of redox-active media, are commonly prepared by plating a second metal onto zero-valent iron (e.g., Ni/Fe and Pd/Fe) and have been shown to accelerate solvent degradation rates relative to untreated iron metal. The long-term effectiveness of this approach, however, has not yet been determined in groundwater treatability tests. The results of a Ni-plated iron column study using site groundwater indicate that a change in reduction mechanism (to catalytic dehydrohalogenation/hydrogenation) accounts for the observed rate enhancement. A significant loss in media reactivity was observed over time, attributable to Ni catalyst deactivation or poisoning. Zero-valent iron systems have not shown similar losses in reactivity in long-term laboratory, pilot or field investigations.

  15. The Pseudomonas syringae effector protein HopZ1a suppresses effector-triggered immunity.

    PubMed

    Macho, Alberto P; Guevara, Carlos M; Tornero, Pablo; Ruiz-Albert, Javier; Beuzón, Carmen R

    2010-09-01

    *The Pseudomonas syringae pv syringae type III effector HopZ1a is a member of the HopZ effector family of cysteine-proteases that triggers immunity in Arabidopsis. This immunity is dependent on HopZ1a cysteine-protease activity, and independent of known resistance genes. We have previously shown that HopZ1a-triggered immunity is partially additive to that triggered by AvrRpt2. These partially additive effects could be caused by at least two mechanisms: their signalling pathways share a common element(s), or one effector interferes with the response triggered by the other. *Here, we investigate the molecular basis for the partially additive effect displayed by AvrRpt2- and HopZ1a-triggered immunities, by analysing competitive indices, hypersensitive response and symptom induction, PR-1 accumulation, expression of PR genes, and systemic acquired resistance (SAR) induction. *Partially additive effects between these defence responses require HopZ1a cysteine-protease activity, and also take place between HopZ1a and AvrRps4 or AvrRpm1-triggered responses. We establish that HopZ1a-triggered immunity is independent of salicylic acid (SA), EDS1, jasmonic acid (JA) and ethylene (ET)-dependent pathways, and show that HopZ1a suppresses the induction of PR-1 and PR-5 associated with P. syringae pv tomato (Pto)-triggered effector-triggered immunity (ETI)-like defences, AvrRpt2-triggered immunity, and Pto or Pto (avrRpt2) activation of SAR, and that suppression requires HopZ1a cysteine-protease activity. *Our results indicate that HopZ1a triggers an unusual resistance independent of known pathways and suppresses SA and EDS1-dependent resistance.

  16. Barriers, Motivations, and Preferences for Physical Activity Among Female African American Older Adults

    PubMed Central

    Gothe, Neha P.; Kendall, Bradley J.

    2016-01-01

    According to the Centers for Disease Control and Prevention, less than 11% of adults more than the age of 65 meet the 2008 Physical Activity Guidelines for Americans. Among minority populations, only 5% of non-Hispanic Black older adults met the guidelines. Given our limited understanding of psychosocial and environmental factors that affect physical activity participation in these groups, the purpose of our focus groups was to investigate barriers, motivators, and preferences of physical activity for community-dwelling African American older adults. Three focus groups were conducted with female African American older adults (N = 20). Questions posed to each focus group targeted motivations and barriers toward physical activity as well as their preferences for physical activity. The motivations included perceived health benefits of physical activity, social support, and enjoyment associated with engagement in physical activity. Prominent barriers included time and physical limitations, peer pressure and family responsibilities, and weather and poor neighborhood conditions. Group activities involving a dance component and novel exercises such as tai-chi or yoga were preferred choices. These findings should be taken into consideration when designing and implementing research or community physical activity programs for female African American older adults. PMID:28138500

  17. Perceived Reasons, Incentives, and Barriers to Physical Activity in Swedish Elderly Men

    PubMed Central

    Bonn, Stephanie E; Trolle Lagerros, Ylva; Sjölander, Arvid; Bälter, Katarina

    2014-01-01

    Background Knowledge about factors influencing physical activity behavior is needed in order to tailor physical activity interventions to the individual. Objective The aim of this study was to explore and describe the perceived reasons, barriers, and incentives to increased physical activity, as well as preferable activities, among elderly men in Sweden. Methods In total, 150 men aged 50-86 years responded to a Web-based questionnaire. Men who reported that they exercised sometimes or often received questions about reasons for physical activity (n=104), while men who reported that they never or seldom exercised received questions about barriers (n=46). Results The most frequent perceived reason for being physically active was health (82%), followed by enjoyment (45%), and a desire to lose/maintain weight (27%). Lack of interest/motivation was identified as the primary perceived barrier (17%). Incentives for increasing the level of activity included becoming more motivated and having a training partner. Walking was the most preferred activity. Conclusions Enjoyment and maintaining a good health were important reasons for engaging in physical activity among Swedish elderly men. PMID:25488655

  18. Hip-Hop and the Academic Canon

    ERIC Educational Resources Information Center

    Abe, Daudi

    2009-01-01

    Over the last 30 years, the hip-hop movement has risen from the margins to become the preeminent force in US popular culture. In more recent times academics have begun to harness the power of hip-hop culture and use it as a means of infusing transformative knowledge into the mainstream academic discourse. On many college campuses, hip-hop's…

  19. Young adult males' motivators and perceived barrier towards eating healthily and being active: A qualitative study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a lack of understanding of young men's perspectives in obesity-related research. This study aims to: (1) identify young men's perceived motivators and barriers in adopting healthy eating and physical activity behaviors, and (2) explore any differences in responses by weight status categorie...

  20. Adolescents' Perspectives on the Barriers and Facilitators of Physical Activity: A Systematic Review of Qualitative Studies

    ERIC Educational Resources Information Center

    Martins, João; Marques, Adilson; Sarmento, Hugo; Carreiro da Costa, Francisco

    2015-01-01

    This article examined qualitative studies of adolescents' perspectives about the facilitators and barriers of physical activity, published from 2007 to 2014. A systematic review of "Web of Science", "EBSCO", "Psychinfo" and "ERIC" databases was performed according to Preferred Reporting Items for Systematic…

  1. Ethnic and Socioeconomic Comparisons of Fitness, Activity Levels, and Barriers to Exercise in High School Females

    ERIC Educational Resources Information Center

    Fahlman, Mariane M.; Hall, Heather L.; Lock, Robyn

    2006-01-01

    The purpose of this study was to determine if high school females differed in individual measures of health-related physical fitness, barriers to exercise, or activity level based on ethnicity or socioeconomic status. A cross-sectional sample consisting of African American (28%), Hispanic (23%), and white (49%) female high school students, 46%…

  2. A Comparison of Motivational Factors and Barriers to Physical Activity among Traditional versus Nontraditional College Students

    ERIC Educational Resources Information Center

    Kulavic, Kimberly; Hultquist, Cherilyn N.; McLester, John R.

    2013-01-01

    Objective: To investigate the motivational factors and the barriers to physical activity (PA) in traditional college students (TS) and nontraditional college students (NTS) and determine if differences exist between these 2 groups. Participants: A total of 746 college students; 628 were TS (19.1 [plus-minus] 1.2 years), and 118 were NTS (31.2…

  3. Adolescents' Self-Efficacy to Overcome Barriers to Physical Activity Scale

    ERIC Educational Resources Information Center

    Dwyer, John J. M.; Chulak, Tala; Maitland, Scott; Allison, Kenneth R.; Lysy, Daria C.; Faulkner, Guy E. J.; Sheeshka, Judy

    2012-01-01

    This paper describes a revised measure of self-efficacy to overcome barriers to moderate and vigorous physical activity in a sample of 484 high school students in Toronto, Ontario. The students had a mean age of 15.3 years. Principal axis factoring with oblique rotation yielded five factors: self-efficacy to overcome internal, harassment, physical…

  4. Confronting Physical Activity Programming Barriers for People with Disabilities: The Empowerment Model

    ERIC Educational Resources Information Center

    Moran, Thomas Eugene; Taliaferro, Andrea R.; Pate, Joshua R.

    2014-01-01

    Community-based physical activity programs for people with disabilities have barriers that are unique to their program leader qualifications and the population they serve. Moran and Block (2010) argued that there is a need for practical strategies that are easy for communities to implement, maximize resources, and minimize the impact of barriers…

  5. A Qualitative Examination of Perceived Barriers and Facilitators of Physical Activity for Urban and Rural Youth

    ERIC Educational Resources Information Center

    Moore, Justin B.; Jilcott, Stephanie B.; Shores, Kindal A.; Evenson, Kelly R.; Brownson, Ross C.; Novick, Lloyd F.

    2010-01-01

    Many adolescents, both rural and urban, are not meeting the recommended levels for physical activity (PA). This investigation was designed to elicit socioecologic barriers and facilitators for PA in rural and urban middle school youth and their parents. Thirteen focus groups were conducted with 41 youth and 50 parents from eastern North Carolina.…

  6. Perceived Barriers to Faculty Achievement in the Area of Scholarly Activity.

    ERIC Educational Resources Information Center

    Woehrle, Mary Beth; Gross, Sanford M.

    1999-01-01

    A survey of 35 Illinois College of Optometry faculty investigated perceived barriers to scholarly activity, including time management, communication skills, knowledge of research design and statistics, computer literacy, institutional support, use of human or material resources, and library resource skills. A majority felt their skills were…

  7. Adolescents' perspectives on the barriers and facilitators of physical activity: a systematic review of qualitative studies.

    PubMed

    Martins, João; Marques, Adilson; Sarmento, Hugo; Carreiro da Costa, Francisco

    2015-10-01

    This article examined qualitative studies of adolescents' perspectives about the facilitators and barriers of physical activity, published from 2007 to 2014. A systematic review of 'Web of Science', 'EBSCO', 'Psychinfo' and 'ERIC' databases was performed according to Preferred Reporting Items for Systematic reviews and Meta-analyses guidelines. The following keywords were used: 'physical activity' and 'physical education', each one individually associated with 'correlate', 'determinant', 'facilitator', 'barrier', 'factor influen*', and with 'qualitative', 'focus group', 'interview', "narrative'. Out of 3815 studies initially identified, due to inclusion and quality criteria, only 12 were fully reviewed. Studies' outcomes were analyzed through thematic analysis. The majority of these reported research with young adolescent girls. Few studies have considered the socioeconomic status influence. According to young people's perspectives, the main facilitators and hampering factors to their participation in physical activity were the following: attitude toward physical activity; motivation; perceptions of competence and body image; fun; influence of friends, family and physical education teachers and environmental physical activity opportunities. Specific life transition periods were referred only as a barrier to physical activity. Strategies of pedagogical actions and for developing physical activity intervention programs were discussed, in order to effectively promote the adoption of active lifestyles among youth.

  8. Hip-Hop Pop Art

    ERIC Educational Resources Information Center

    Talley, Clarence, Sr.

    2011-01-01

    Art has a way of helping students better understand and appreciate the world around them, particularly the things that are most important to them. Hip hop is one of those generational genres that capture the attention of young students like few other things do. Drawing on this genre to get students to create art is an excellent way to demonstrate…

  9. Hopping conduction in polycrystalline semiconductors

    NASA Astrophysics Data System (ADS)

    Sharma, R. P.; Shukla, A. K.; Kapoor, A. K.; Srivastava, R.; Mathur, P. C.

    1985-03-01

    Measurements of dc conductivity (sigma) on polycrystalline semiconductors, viz., InSb, Si, and CdTe, have been reported in the temperature range 77-300 K. The conduction mechanism near liquid-nitrogen temperature has been identified as the hopping of charge carriers from the charged trap centers to empty traps near the Fermi level.

  10. Long range hopping mobility platform.

    SciTech Connect

    Spletzer, Barry Louis; Fischer, Gary John

    2003-03-01

    Sandia National Laboratories has developed a mesoscale hopping mobility platform (Hopper) to overcome the longstanding problems of mobility and power in small scale unmanned vehicles. The system provides mobility in situations such as negotiating tall obstacles and rough terrain that are prohibitive for other small ground base vehicles. The Defense Advanced Research Projects Administration (DARPA) provided the funding for the hopper project.

  11. Age-Associated Perceptions of Physical Activity Facilitators and Barriers Among Women in Rural Southernmost Illinois

    PubMed Central

    Carnahan, Leslie R.; Peacock, Nadine R.

    2016-01-01

    Introduction Women living in rural areas in the United States experience disproportionately high rates of diseases such as obesity and heart disease and are less likely than women living in urban areas to meet daily physical activity (PA) recommendations. The purpose of our research was to understand age-specific perceptions of barriers and facilitators to rural women engaging in PA and to identify strategies to promote PA among these women. Methods As part of a community health assessment to learn about women’s health issues, 110 adult women participated in 14 focus groups. The women were divided into 4 age groups, and focus groups were held in various community settings. We used qualitative analysis methods to explore themes in the women’s narratives, including themes related to PA knowledge, PA behavior, and access to PA facilities. Results Participants described multiple and often conflicting individual, social, and environmental barriers and facilitators to PA. Several barriers and facilitators were shared across age groups (eg, competing priorities and inadequate knowledge about PA’s role in disease prevention and disease management). Other barriers (eg, illness and injury) and facilitators (eg, PA as a social opportunity) differed by age group. Conclusion Rural women in southernmost Illinois have often contradictory barriers and facilitators to PA, and those barriers and facilitators are different at different points in a woman’s life. Our findings suggest the need for multilevel, multisector approaches to promote PA. Additionally, this research supports the need for tailored PA promotion programs for rural women to address the barriers these women face across their lifespan. PMID:27685431

  12. Electron Thermal Transport Barrier and Magnetohydrodynamic Activity Observed in Tokamak Plasmas with Negative Central Shear

    SciTech Connect

    de Baar, M.R.; Hogeweij, G.M.; Lopes Cardozo, N.J.; Oomens, A.A.; Schueller, F.C.

    1997-06-01

    In the Rijnhuizen Tokamak Project, plasmas with steady-state negative central shear (NCS) are made with off-axis electron cyclotron heating. Shifting the power deposition by 2mm results in a sharp transition of confinement. The good confinement branch features a transport barrier at the off-axis minimum of the safety factor (q) , where q{le}3, and two magnetohydrodynamic (MHD) instabilities, where one is localized at the off-axis minimum of q and one covers the entire NCS region. The low confinement branch has q{gt}3 everywhere, no transport barrier, and no MHD activity. {copyright} {ital 1997} {ital The American Physical Society}

  13. Sampling Practices and Social Spaces: Exploring a Hip-Hop Approach to Higher Education

    ERIC Educational Resources Information Center

    Petchauer, Emery

    2010-01-01

    Much more than a musical genre, hip-hop culture exists as an animating force in the lives of many young adults. This article looks beyond the moral concerns often associated with rap music to explore how hip-hop as a larger set of expressions and practices implicates the educational experiences, activities, and approaches for students. The article…

  14. Biotransformation of hop-derived monoterpene alcohols by lager yeast and their contribution to the flavor of hopped beer.

    PubMed

    Takoi, Kiyoshi; Koie, Koichiro; Itoga, Yutaka; Katayama, Yuta; Shimase, Masayuki; Nakayama, Yasuyuki; Watari, Junji

    2010-04-28

    It is well-known that various beers contain many flavor compounds derived from barley malts, hops, yeast fermentation, and other raw materials. Among these flavor compounds, terpenoids are mainly derived from hops. Linalool, one of the monoterpene alcohols, has been found in various beers and been regarded as an important factor for a hop-derived beer flavor. We focus on contributions of other monoterpene alcohols (geraniol, beta-citronellol, nerol, and alpha-terpineol) to hopped beer flavor. Several researchers have reported that monoterpene alcohols are biotransformed by yeast and that geraniol is mainly transformed to beta-citronellol during the first 2-4 days in model fermentation. In this study, we investigated the biotransformation of monoterpene alcohols during fermentation of hopped beer by using various hop cultivars. As a result, geraniol drastically decreased during the first 3 days. beta-Citronellol was almost absent in wort and gently increased during the total fermentation period. The concentrations of geraniol and beta-citronellol in finished beer increased, depending on the initial concentration of geraniol in the wort. The continuous increase of beta-citronellol did not correspond to the fast decrease of geraniol. This increase of beta-citronellol might be partly explained by an occurrence of glycosidically bound flavor precursor and a glucoside hydrolase activity secreted from lager yeast. In addition, we examined flavor characteristics of monoterpene alcohols and found that there was an additive effect among linalool, geraniol, and beta-citronellol and that only 5 microg/L of geraniol and beta-citronellol were enough for this effect. Therefore, it is suggested that not only linalool but also geraniol and beta-citronellol might contribute to hopped beer flavor at lower levels, at which OAVs of these compounds become below 1.0.

  15. Perceived Barriers by University Students in the Practice of Physical Activities

    PubMed Central

    Gómez-López, Manuel; Gallegos, Antonio Granero; Extremera, Antonio Baena

    2010-01-01

    The main goal of this research is to study in detail the main characteristics of university students in order to find out the reasons why they have adopted an inactive lifestyle. In order to do so, a questionnaire on the analysis of sports habits and lifestyle was given to 323 students. They were taken from a representative sample of 1834 students. These 323 students had pointed out at the moment of the fieldwork, not having practiced any sport in their spare time. Our findings point out that there are diverse reasons for this. On one hand, reasons referred to as external barriers such as lack of time, on the other hand, internal barriers such as not liking the physical activity, not seeing its practicality or usefulness, feeling lazy or with apathy, or thinking that they are not competent in this type of activities. Other reasons such as the lack of social support are grouped within the external barriers. Finally, it is important to stress that there are also differences based on gender with respect to motivation. Key points External barriers prevail in university students. The lack of time is among the most highlighted ones. Statistically significant results have been found regarding the gender variable. The results are very important since they are considered to be valuable information for university institutions when guiding and diversifying their offer of physical and sport activities. Also as a guide in the design of support policies and national sport management guidelines. PMID:24149629

  16. Optimum Detection of Frequency-Hopped Signals

    NASA Technical Reports Server (NTRS)

    Cheng, Unjeng; Levitt, Barry; Polydoros, Andreas; Simon, Marvin K.

    1992-01-01

    This paper derives and analyzes optimum and near-optimum structures for detecting frequency-hopped (FH) signals with arbitrary modulation in additive white Gaussian noise. The principalmodulation formats considered are M-ary frequency-shift-keying (MFSK) with fast frequency hopping(FFH) wherein a single tone is transmitted per hop, and slow frequency hopping (SFH) with multipleMFSK tones (data symbols) per hop. The SFH detection category has not previously been addressedin the open literature and its analysis is generally more complex than FFH.

  17. Zelda overcomes the high intrinsic nucleosome barrier at enhancers during Drosophila zygotic genome activation

    PubMed Central

    Sun, Yujia; Nien, Chung-Yi; Chen, Kai; Liu, Hsiao-Yun; Johnston, Jeff; Zeitlinger, Julia; Rushlow, Christine

    2015-01-01

    The Drosophila genome activator Vielfaltig (Vfl), also known as Zelda (Zld), is thought to prime enhancers for activation by patterning transcription factors (TFs). Such priming is accompanied by increased chromatin accessibility, but the mechanisms by which this occurs are poorly understood. Here, we analyze the effect of Zld on genome-wide nucleosome occupancy and binding of the patterning TF Dorsal (Dl). Our results show that early enhancers are characterized by an intrinsically high nucleosome barrier. Zld tackles this nucleosome barrier through local depletion of nucleosomes with the effect being dependent on the number and position of Zld motifs. Without Zld, Dl binding decreases at enhancers and redistributes to open regions devoid of enhancer activity. We propose that Zld primes enhancers by lowering the high nucleosome barrier just enough to assist TFs in accessing their binding motifs and promoting spatially controlled enhancer activation if the right patterning TFs are present. We envision that genome activators in general will utilize this mechanism to activate the zygotic genome in a robust and precise manner. PMID:26335633

  18. Motivators of and Barriers to Engaging in Physical Activity: Perspectives of Low-Income Culturally Diverse Adolescents and Adults

    ERIC Educational Resources Information Center

    Bragg, Marie A.; Tucker, Carolyn M.; Kaye, Lily B.; Desmond, Frederic

    2009-01-01

    Background: Obesity rates are rising in the United States, especially among low-income and racial/ethnic minority individuals. Exploring motivators and barriers relative to engaging in physical activity is imperative. Purpose: The purpose of this study was to identify motivators and barriers relative to engagement in physical activity as reported…

  19. Motivation and Barriers for Leisure-Time Physical Activity in Socioeconomically Disadvantaged Women

    PubMed Central

    Santos, Inês; Ball, Kylie; Crawford, David; Teixeira, Pedro J.

    2016-01-01

    Introduction The aim of this study was to examine cross-sectional and longitudinal associations between motivation and barriers for physical activity, and physical activity behavior in women living in socioeconomic disadvantage. This study also examined whether weight control intentions moderate those associations. Methods Data from 1664 women aged 18–46 years was collected at baseline and three-year follow-up as part of the Resilience for Eating and Activity Despite Inequality study. In mail-based surveys, women reported sociodemographic and neighborhood environmental characteristics, intrinsic motivation, goals and perceived family barriers to be active, weight control intentions and leisure-time physical activity (assessed through the IPAQ-L). Linear regression models assessed the association of intrinsic motivation, goals and barriers with physical activity at baseline and follow-up, adjusting for environmental characteristics and also physical activity at baseline (for longitudinal analyses), and the moderating effects of weight control intentions were examined. Results Intrinsic motivation and, to a lesser extent, appearance and relaxation goals for being physically active were consistently associated with leisure-time physical activity at baseline and follow-up. Perceived family barriers, health, fitness, weight and stress relief goals were associated with leisure-time physical activity only at baseline. Moderated regression analyses revealed that weight control intentions significantly moderated the association between weight goals and leisure-time physical activity at baseline (β = 0.538, 99% CI = 0.057, 0.990) and between intrinsic motivation and leisure-time physical activity at follow-up (β = 0.666, 99% CI = 0.188, 1.145). For women actively trying to control their weight, intrinsic motivation was significantly associated with leisure-time physical activity at follow-up (β = 0.184, 99% CI = 0.097, 0.313). Conclusions Results suggest that

  20. Charge transport in molecular junctions: From tunneling to hopping with the probe technique

    SciTech Connect

    Kilgour, Michael; Segal, Dvira

    2015-07-14

    We demonstrate that a simple phenomenological approach can be used to simulate electronic conduction in molecular wires under thermal effects induced by the surrounding environment. This “Landauer-Büttiker’s probe technique” can properly replicate different transport mechanisms, phase coherent nonresonant tunneling, ballistic behavior, and hopping conduction. Specifically, our simulations with the probe method recover the following central characteristics of charge transfer in molecular wires: (i) the electrical conductance of short wires falls off exponentially with molecular length, a manifestation of the tunneling (superexchange) mechanism. Hopping dynamics overtakes superexchange in long wires demonstrating an ohmic-like behavior. (ii) In off-resonance situations, weak dephasing effects facilitate charge transfer, but under large dephasing, the electrical conductance is suppressed. (iii) At high enough temperatures, k{sub B}T/ϵ{sub B} > 1/25, with ϵ{sub B} as the molecular-barrier height, the current is enhanced by a thermal activation (Arrhenius) factor. However, this enhancement takes place for both coherent and incoherent electrons and it does not readily indicate on the underlying mechanism. (iv) At finite-bias, dephasing effects may impede conduction in resonant situations. We further show that memory (non-Markovian) effects can be implemented within the Landauer-Büttiker’s probe technique to model the interaction of electrons with a structured environment. Finally, we examine experimental results of electron transfer in conjugated molecular wires and show that our computational approach can reasonably reproduce reported values to provide mechanistic information.

  1. Surface Proton Hopping and Coupling Pathway of Water Oxidation on Cobalt Oxide Catalyst

    NASA Astrophysics Data System (ADS)

    Pham, Hieu; Cheng, Mu-Jeng; Frei, Heinz; Wang, Lin-Wang

    We propose an oxidation pathway of water splitting on cobalt oxide surface with clear thermodynamic and kinetic details. The density-functional theory studies suggest that the coupled proton-electron transfer is not necessarily sequential and implicit in every elementary step of this mechanistic cycle. Instead, the initial O-O bond could be formed by the landing of water molecule on the surface oxos, which is then followed by the dispatch of protons through the hopping manner and subsequent release of di-oxygen. Our theoretical investigations of intermediates and transition states indicate that all chemical conversions in this pathway, including the proton transfers, are possible with low activation barriers, in addition to their favorable thermodynamics. Our hypothesis is supported by recent experimental observations of surface superoxide that is stabilized by hydrogen bonding to adjacent hydroxyl group, as an intermediate on fast-kinetics catalytic site.

  2. A coculture model of the lung–blood barrier: the role of activated phagocytic cells.

    PubMed

    Luyts, Katrien; Napierska, Dorota; Dinsdale, David; Klein, Sebastian G; Serchi, Tommaso; Hoet, Peter H M

    2015-02-01

    We developed a coculture model of the lung–blood barrier using human bronchial epithelial cells(16HBE14o-), monocytes (THP-1) and human lung microvascular endothelial cells (HLMVEC) in which several parameters can be assessed simultaneously. The epithelial and endothelial cells were grown on opposite sides of a microporous membrane. Electron and confocal microscopic pictures show the presence of the cells in their appropriate compartment and both cell types do not show evidence of growing through the pores. Out of three endothelial cell types (EAhy.926, HUVEC and HLMVEC), the last was chosen as the most appropriate cell type, best resembling the pulmonary endothelium and allowing the expression of functional tight junctions in the 16HBE14o- monolayer with sufficiently high transepithelial electrical resistance (TEER) values. Finally, monocytes were added to the apical compartment. PMA-activated macrophages significantly affected barrier integrity (73% TEER reduction compared to control after 24 h) and disrupted the epithelial tight junctions as shown by redistribution of ZO-1 labeling. Alternatively, monocytes could be activated using lipopolysaccharide, at a sub-toxic level int he apical compartment and only induced a small, though significant, reduction in TEER.This coculture system is a representative model of the lung–blood barrier with barrier integrity as the main toxicity endpoint.

  3. Active barrier films of PET for solar cell application: Processing and characterization

    SciTech Connect

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana

    2014-05-15

    A preliminary investigation was carried out on the possibility to improve the protective action offered by the standard multilayer structures used to encapsulate photovoltaic devices. With this aim, a commercial active barrier PET-based material, able to absorb oxygen when activated by liquid water, was used to produce flexible and transparent active barrier films, by means of a lab-scale film production plant. The obtained film, tested in terms of thermal, optical and oxygen absorption properties, shows a slow oxygen absorption kinetics, an acceptable transparency and an easy roll-to-roll processability, so proving itself as a good candidate for the development of protective coating for solar cells against the atmospheric degradation agents like the rain.

  4. Hip-Hop--What's in It for the Academy? Self-Understanding, Pedagogy and Aesthetical Learning Processes in Everyday Cultural Praxis

    ERIC Educational Resources Information Center

    Söderman, Johan; Sernhede, Ove

    2016-01-01

    Since hip-hop first appeared in New York over 35 years ago, it has been associated with social activism and education. Accordingly, it is not surprising that academic institutions in universities and K-12 schools are interested in hip-hop. In this article, we will highlight the "hip-hop academisation" and map out a new direction in a…

  5. Nucleosome positioning and kinetics near transcription-start-site barriers are controlled by interplay between active remodeling and DNA sequence.

    PubMed

    Parmar, Jyotsana J; Marko, John F; Padinhateeri, Ranjith

    2014-01-01

    We investigate how DNA sequence, ATP-dependent chromatin remodeling and nucleosome-depleted 'barriers' co-operate to determine the kinetics of nucleosome organization, in a stochastic model of nucleosome positioning and dynamics. We find that 'statistical' positioning of nucleosomes against 'barriers', hypothesized to control chromatin structure near transcription start sites, requires active remodeling and therefore cannot be described using equilibrium statistical mechanics. We show that, unlike steady-state occupancy, DNA site exposure kinetics near a barrier is dominated by DNA sequence rather than by proximity to the barrier itself. The timescale for formation of positioning patterns near barriers is proportional to the timescale for active nucleosome eviction. We also show that there are strong gene-to-gene variations in nucleosome positioning near barriers, which are eliminated by averaging over many genes. Our results suggest that measurement of nucleosome kinetics can reveal information about sequence-dependent regulation that is not apparent in steady-state nucleosome occupancy.

  6. Impact of compliance with different guidelines on physical activity during pregnancy and perceived barriers to leisure physical activity.

    PubMed

    Santos, Paula Clara; Abreu, Sandra; Moreira, Carla; Lopes, Diana; Santos, Rute; Alves, Odete; Silva, Pedro; Montenegro, Nuno; Mota, Jorge

    2014-01-01

    The aims of the this prospective study were to analyse physical activity (PA) engagement during the first and second trimesters, considering the different guidelines published on PA, to document the individual characteristics associated with the accomplishment of these guidelines and to examine pregnant women's perceived barriers to leisure PA, using a socioecological framework. A sample of 133 pregnant women in two stages--at 10-12 weeks' gestation (T1) and 20-22 weeks' gestation (T2)--were evaluated. PA was assessed by accelerometry during the T1 and T2 evaluation stages. Socio-demographic characteristics, lifestyle factors and barriers to leisure PA were assessed via questionnaire. A large proportion of women (ranging from 32% to 96%) did not reach the levels of PA recommended by the guidelines. There were no significant differences between T1 and T2 with regard to compliance with PA recommendations. A decrease in PA levels from T1 to T2 was noted for all recommendations. No associations were found between participants' characteristics and adherence to the recommendations in T1 and T2. No significant differences were found in barriers to leisure PA between T1 and T2. The most commonly reported barriers to leisure PA were intrapersonal, not health related. Our results indicate that there were no differences between trimesters regarding compliance of PA recommendations, and perceived barriers were similar in both trimesters.

  7. High-Speed On-Board Data Processing for Science Instruments: HOPS

    NASA Technical Reports Server (NTRS)

    Beyon, Jeffrey

    2015-01-01

    The project called High-Speed On-Board Data Processing for Science Instruments (HOPS) has been funded by NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) program during April, 2012 â€" April, 2015. HOPS is an enabler for science missions with extremely high data processing rates. In this three-year effort of HOPS, Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) and 3-D Winds were of interest in particular. As for ASCENDS, HOPS replaces time domain data processing with frequency domain processing while making the real-time on-board data processing possible. As for 3-D Winds, HOPS offers real-time high-resolution wind profiling with 4,096-point fast Fourier transform (FFT). HOPS is adaptable with quick turn-around time. Since HOPS offers reusable user-friendly computational elements, its FPGA IP Core can be modified for a shorter development period if the algorithm changes. The FPGA and memory bandwidth of HOPS is 20 GB/sec while the typical maximum processor-to-SDRAM bandwidth of the commercial radiation tolerant high-end processors is about 130-150 MB/sec. The inter-board communication bandwidth of HOPS is 4 GB/sec while the effective processor-to-cPCI bandwidth of commercial radiation tolerant high-end boards is about 50-75 MB/sec. Also, HOPS offers VHDL cores for the easy and efficient implementation of ASCENDS and 3-D Winds, and other similar algorithms. A general overview of the 3-year development of HOPS is the goal of this presentation.

  8. Non-Hermitian surface hopping

    NASA Astrophysics Data System (ADS)

    Gao, Xing; Thiel, Walter

    2017-01-01

    We present a generalized non-Hermitian equation of motion (nH-EOM) to go beyond standard trajectory surface hopping dynamics. The derivation is based on the Born-Huang expansion of the total wave function and the polar representation of the nuclear factor. The nH-EOM contains two additional terms, a skew symmetry term iΓ with dissipation operator Γ to account for decoherence, and a kinetic-energy renormalization term to account for phase shifts, without destroying the invariance to the choice of representation. Numerically, the nH-EOM can still be solved efficiently using a semiclassical approximation in the framework of Tully's fewest-switches surface hopping (FSSH) algorithm. Applications to model Hamiltonians demonstrate improved performance over the standard FSSH approach, through comparison to exact quantum results.

  9. Solution structure and DNA-binding properties of the winged helix domain of the meiotic recombination HOP2 protein.

    PubMed

    Moktan, Hem; Guiraldelli, Michel F; Eyster, Craig A; Zhao, Weixing; Lee, Chih-Ying; Mather, Timothy; Camerini-Otero, R Daniel; Sung, Patrick; Zhou, Donghua H; Pezza, Roberto J

    2014-05-23

    The HOP2 protein is required for efficient double-strand break repair which ensures the proper synapsis of homologous chromosomes and normal meiotic progression. We previously showed that in vitro HOP2 shows two distinctive activities: when it is incorporated into a HOP2-MND1 heterodimer, it stimulates DMC1 and RAD51 recombination activities, and the purified HOP2 alone is proficient in promoting strand invasion. The structural and biochemical basis of HOP2 action in recombination are poorly understood; therefore, they are the focus of this work. Herein, we present the solution structure of the amino-terminal portion of mouse HOP2, which contains a typical winged helix DNA-binding domain. Together with NMR spectral changes in the presence of double-stranded DNA, protein docking on DNA, and mutation analysis to identify the amino acids involved in DNA coordination, our results on the three-dimensional structure of HOP2 provide key information on the fundamental structural and biochemical requirements directing the interaction of HOP2 with DNA. These results, in combination with mutational experiments showing the role of a coiled-coil structural feature involved in HOP2 self-association, allow us to explain important aspects of the function of HOP2 in recombination.

  10. Skin Barrier Recovery by Protease-Activated Receptor-2 Antagonist Lobaric Acid

    PubMed Central

    Joo, Yeon Ah; Chung, Hyunjin; Yoon, Sohyun; Park, Jong Il; Lee, Ji Eun; Myung, Cheol Hwan; Hwang, Jae Sung

    2016-01-01

    Atopic dermatitis (AD) results from gene and environment interactions that lead to a range of immunological abnormalities and breakdown of the skin barrier. Protease-activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is expressed in suprabasal layers of the epidermis. PAR2 is activated by both trypsin and a specific agonist peptide, SLIGKV-NH2 and is involved in both epidermal permeability barrier homeostasis and epithelial inflammation. In this study, we investigated the effect of lobaric acid on inflammation, keratinocyte differentiation, and recovery of the skin barrier in hairless mice. Lobaric acid blocked trypsin-induced and SLIGKV-NH2-induced PAR2 activation resulting in decreased mobilization of intracellular Ca2+ in HaCaT keratinocytes. Lobaric acid reduced expression of interleukin-8 induced by SLIGKV-NH2 and thymus and activation regulated chemokine (TARC) induced by tumor necrosis factor-a (TNF-α) and IFN-γ in HaCaT keratinocytes. Lobaric acid also blocked SLIGKV-NH2-induced activation of ERK, which is a downstream signal of PAR2 in normal human keratinocytes (NHEKs). Treatment with SLIGKV-NH2 downregulated expression of involucrin, a differentiation marker protein in HaCaT keratinocytes, and upregulated expression of involucrin, transglutamase1 and filaggrin in NHEKs. However, lobaric acid antagonized the effect of SLIGKV-NH2 in HaCaT keratinocytes and NHEKs. Topical application of lobaric acid accelerated barrier recovery kinetics in a SKH-1 hairless mouse model. These results suggested that lobaric acid is a PAR2 antagonist and could be a possible therapeutic agent for atopic dermatitis. PMID:27169822

  11. Skin barrier homeostasis in atopic dermatitis: feedback regulation of kallikrein activity.

    PubMed

    Tanaka, Reiko J; Ono, Masahiro; Harrington, Heather A

    2011-01-01

    Atopic dermatitis (AD) is a widely spread cutaneous chronic disease characterised by sensitive reactions (eg. eczema) to normally innocuous elements. Although relatively little is understood about its underlying mechanisms due to its complexity, skin barrier dysfunction has been recognised as a key factor in the development of AD. Skin barrier homeostasis requires tight control of the activity of proteases, called kallikreins (KLKs), whose activity is regulated by a complex network of protein interactions that remains poorly understood despite its pathological importance. Characteristic symptoms of AD include the outbreak of inflammation triggered by external (eg. mechanical and chemical) stimulus and the persistence and aggravation of inflammation even if the initial stimulus disappears. These characteristic symptoms, together with some experimental data, suggest the presence of positive feedback regulation for KLK activity by inflammatory signals. We developed simple mathematical models for the KLK activation system to study the effects of feedback loops and carried out bifurcation analysis to investigate the model behaviours corresponding to inflammation caused by external stimulus. The model analysis confirmed that the hypothesised core model mechanisms capture the essence of inflammation outbreak by a defective skin barrier. Our models predicted the outbreaks of inflammation at weaker stimulus and its longer persistence in AD patients compared to healthy control. We also proposed a novel quantitative indicator for inflammation level by applying principal component analysis to microarray data. The model analysis reproduced qualitative AD characteristics revealed by this indicator. Our results strongly implicate the presence and importance of feedback mechanisms in KLK activity regulation. We further proposed future experiments that may provide informative data to enhance the system-level understanding on the regulatory mechanisms of skin barrier in AD and

  12. Influence of skin penetration enhancers on skin barrier function and skin protease activity.

    PubMed

    Mohammed, Diar; Hirata, Kazumasa; Hadgraft, Jonathan; Lane, Majella E

    2014-01-23

    In order to overcome the skin's excellent barrier function formulation scientists often employ skin penetration enhancers (SPEs) in topical and transdermal formulations. The effects of these compounds on skin health is still not well understood at the molecular level. The aim of the present work was to probe the effects of some common SPEs on desquamatory protease activity in healthy skin. The SPEs studied were isopropyl myristate (IPM), propylene glycol, (PG), propylene glycol laurate (PGL) and Transcutol™ (TC). Occluded infinite doses of each SPE were applied to human volunteers for 24 h. Transepidermal water loss (TEWL) measurements were taken before and after application of SPEs. Tape strips were collected from the treated sites to determine protein content and the activity of two desquamatory proteases kallikrein 5 (KLK5) and kallikrein 7 (KLK7). TEWL values were also measured after tape stripping. PG was found to elevate both TEWL values and KLK7 activity to a significant extent (p<0.05). No significant effects were observed for the other SPEs. The ability of PG to alter the skin barrier at the macroscopic level and the influence of the molecule on protease activity reported here may have implications for its use in topical formulations used for the management of impaired skin barrier function such as atopic eczema or psoriasis.

  13. Facilitators and barriers to physical activity as perceived by older adults with intellectual disability.

    PubMed

    van Schijndel-Speet, Marieke; Evenhuis, Heleen M; van Wijck, Ruud; van Empelen, Pepijn; Echteld, Michael A

    2014-06-01

    Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID for specific physical activities, and to gain insight into facilitators and barriers to engaging into PA. Fourteen in-depth interviews and four focus groups were undertaken, with a total of 40 older adults with mild and moderate ID included in the analysis. NVivo software was used for analysing the transcribed verbatim interviews. In total, 30 codes for facilitators and barriers were identified. Themes concerning facilitators to PA were enjoyment, support from others, social contact and friendship, reward, familiarity, and routine of activities. Themes concerning barriers to PA were health and physiological factors, lack of self-confidence, lack of skills, lack of support, transportation problems, costs, and lack of appropriate PA options and materials. The results of the present study suggest that older adults with ID may benefit from specific PA programs, adapted to their individual needs and limitations. Results can be used for developing feasible health promotion programs for older adults with ID.

  14. Hall effect in hopping regime

    NASA Astrophysics Data System (ADS)

    Avdonin, A.; Skupiński, P.; Grasza, K.

    2016-02-01

    A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO.

  15. Chaperones get in touch: the Hip-Hop connection.

    PubMed

    Frydman, J; Höhfeld, J

    1997-03-01

    Recent findings emphasize that different molecular chaperones cooperate during intracellular protein biogenesis. Mechanistic aspects of chaperone cooperation are now emerging from studies on the regulation of certain signal transduction pathways mediated by Hsc70 and Hsp90 in the eukaryotic cytosol. Efficient cooperation appears to be achieved through a defined regulation of Hsc70 activity by the chaperone cofactors Hip and Hop.

  16. Male gender role strain as a barrier to African American men's physical activity.

    PubMed

    Griffith, Derek M; Gunter, Katie; Allen, Julie Ober

    2011-10-01

    Despite the potential health consequences, African American men tend to treat their roles as providers, fathers, spouses, and community members as more important than engaging in health behaviors such as physical activity. We conducted 14 exploratory focus groups with 105 urban, middle-aged African American men from the Midwest to examine factors that influence their health behaviors. Thematic content analysis revealed three interrelated barriers to physical activity: (a) work, family, and community commitments and priorities limited time and motivation for engaging in physical activity; (b) physical activity was not a normative individual or social activity and contributed to men prioritizing work and family responsibilities over physical activity; and (c) the effort men exerted in seeking to fulfill the provider role limited their motivation and energy to engage in physical activity. These findings highlight the need for physical activity interventions that consider how health fits in the overall context of men's lives.

  17. Barriers to physical activity promotion by general practitioners and practice nurses

    PubMed Central

    McKenna, J.; Naylor, P. J.; McDowell, N.

    1998-01-01

    OBJECTIVE: To examine the promotion of physical activity by general practitioners (GPs) and practice nurses (PNs). METHODS: A questionnaire that examined the types of barriers and the levels of their influence as well as stage of change for activity promotion and for personal behaviour was mailed to 846 subjects. RESULTS: The return rate exceeded 70% in each group with a high proportion (69%) of GPs and PNs reporting that they regularly promote physical activity with their patients. GPs were less likely to regularly promote physical activity with their patients if they indicated lack of time as a barrier (odds ratio (OR) = 0.73, 95% confidence interval (CI) 0.58 to 0.93) or lack of incentives (OR = 0.74, 95% CI 0.59 to 0.94), and more likely to promote exercise if they themselves were regular exercisers (OR = 3.19, 95% CI 1.96 to 5.18). However, for PNs longer consultation times (by 1.5 to 2 minutes) had a higher likelihood of producing regular promotion of activity (OR = 1.61, 95% CI 1.02 to 1.62). For PNs personal physical activity stage was the strongest significant predictor of promotion level, but with a stronger effect (OR = 4.77, 95% CI 1.48 to 15.35) than in the GPs. CONCLUSION: The main finding is that GPs in the action or maintenance stage of changing their own physical activity are three times more likely to regularly promote the same behaviour in their patients than those in the other stages; for PNs the same difference quadruples the likelihood of them promoting physical activity. Professional readiness to change is influenced by known system barriers in GPs, and not in PNs, but is more strongly predicted by personal physical activity behaviour in both groups. 


 PMID:9773175

  18. Somali Perspectives on Physical Activity: Photovoice to Address Barriers and Resources in San Diego

    PubMed Central

    Murray, Kate; Mohamed, Amina Sheik; Dawson, Darius B.; Syme, Maggie; Abdi, Sahra; Barnack-Tavlaris, Jessica

    2015-01-01

    Background Though many immigrants enter the U.S. with a healthy body weight, this health advantage disappears the longer they reside in the U.S. To better understand the complexities of obesity change within a cultural framework, a community-based participatory research (CBPR) approach, Photovoice, was utilized focusing on physical activity among Muslim Somali women. Objectives The CBPR partnership was formed to identify barriers and resources to engaging in physical activity with goals of advocacy and program development. Methods Muslim Somali women (n = 8) were recruited to participate, trained and provided cameras, and engaged in group discussions about the scenes they photographed. Results Participants identified several barriers, including safety concerns, minimal culturally appropriate resources, and financial constraints. Strengths included public resources and a community support system. The CBPR process identified opportunities and challenges to collaboration and dissemination processes. Conclusions The findings laid the framework for subsequent program development and community engagement. PMID:25981428

  19. Compromised epidermal barrier stimulates Harderian gland activity and hypertrophy in ACBP−/− mice[S

    PubMed Central

    Bek, Signe; Neess, Ditte; Dixen, Karen; Bloksgaard, Maria; Marcher, Ann-Britt; Chemnitz, John; Færgeman, Nils J.; Mandrup, Susanne

    2015-01-01

    Acyl-CoA binding protein (ACBP) is a small, ubiquitously expressed intracellular protein that binds C14-C22 acyl-CoA esters with very high affinity and specificity. We have recently shown that targeted disruption of the Acbp gene leads to a compromised epidermal barrier and that this causes delayed adaptation to weaning, including the induction of the hepatic lipogenic and cholesterogenic gene programs. Here we show that ACBP is highly expressed in the Harderian gland, a gland that is located behind the eyeball of rodents and involved in the production of fur lipids and lipids used for lubrication of the eye lid. We show that disruption of the Acbp gene leads to a significant enlargement of this gland with hypertrophy of the acinar cells and increased de novo synthesis of monoalkyl diacylglycerol, the main lipid species produced by the gland. Mice with conditional targeting of the Acbp gene in the epidermis recapitulate this phenotype, whereas generation of an artificial epidermal barrier during gland development reverses the phenotype. Our findings indicate that the Harderian gland is activated by the compromised epidermal barrier as an adaptive and protective mechanism to overcome the barrier defect. PMID:26142722

  20. Compromised epidermal barrier stimulates Harderian gland activity and hypertrophy in ACBP-/- mice.

    PubMed

    Bek, Signe; Neess, Ditte; Dixen, Karen; Bloksgaard, Maria; Marcher, Ann-Britt; Chemnitz, John; Færgeman, Nils J; Mandrup, Susanne

    2015-09-01

    Acyl-CoA binding protein (ACBP) is a small, ubiquitously expressed intracellular protein that binds C14-C22 acyl-CoA esters with very high affinity and specificity. We have recently shown that targeted disruption of the Acbp gene leads to a compromised epidermal barrier and that this causes delayed adaptation to weaning, including the induction of the hepatic lipogenic and cholesterogenic gene programs. Here we show that ACBP is highly expressed in the Harderian gland, a gland that is located behind the eyeball of rodents and involved in the production of fur lipids and lipids used for lubrication of the eye lid. We show that disruption of the Acbp gene leads to a significant enlargement of this gland with hypertrophy of the acinar cells and increased de novo synthesis of monoalkyl diacylglycerol, the main lipid species produced by the gland. Mice with conditional targeting of the Acbp gene in the epidermis recapitulate this phenotype, whereas generation of an artificial epidermal barrier during gland development reverses the phenotype. Our findings indicate that the Harderian gland is activated by the compromised epidermal barrier as an adaptive and protective mechanism to overcome the barrier defect.

  1. A keratin scaffold regulates epidermal barrier formation, mitochondrial lipid composition, and activity

    PubMed Central

    Kumar, Vinod; Bouameur, Jamal-Eddine; Bär, Janina; Rice, Robert H.; Hornig-Do, Hue-Tran; Roop, Dennis R.; Schwarz, Nicole; Brodesser, Susanne; Thiering, Sören; Leube, Rudolf E.; Wiesner, Rudolf J.; Vijayaraj, Preethi; Brazel, Christina B.; Heller, Sandra; Binder, Hans; Löffler-Wirth, Henry; Seibel, Peter

    2015-01-01

    Keratin intermediate filaments (KIFs) protect the epidermis against mechanical force, support strong adhesion, help barrier formation, and regulate growth. The mechanisms by which type I and II keratins contribute to these functions remain incompletely understood. Here, we report that mice lacking all type I or type II keratins display severe barrier defects and fragile skin, leading to perinatal mortality with full penetrance. Comparative proteomics of cornified envelopes (CEs) from prenatal KtyI−/− and KtyII−/−K8 mice demonstrates that absence of KIF causes dysregulation of many CE constituents, including downregulation of desmoglein 1. Despite persistence of loricrin expression and upregulation of many Nrf2 targets, including CE components Sprr2d and Sprr2h, extensive barrier defects persist, identifying keratins as essential CE scaffolds. Furthermore, we show that KIFs control mitochondrial lipid composition and activity in a cell-intrinsic manner. Therefore, our study explains the complexity of keratinopathies accompanied by barrier disorders by linking keratin scaffolds to mitochondria, adhesion, and CE formation. PMID:26644517

  2. Accurate Modeling of Scaffold Hopping Transformations in Drug Discovery.

    PubMed

    Wang, Lingle; Deng, Yuqing; Wu, Yujie; Kim, Byungchan; LeBard, David N; Wandschneider, Dan; Beachy, Mike; Friesner, Richard A; Abel, Robert

    2017-01-10

    The accurate prediction of protein-ligand binding free energies remains a significant challenge of central importance in computational biophysics and structure-based drug design. Multiple recent advances including the development of greatly improved protein and ligand molecular mechanics force fields, more efficient enhanced sampling methods, and low-cost powerful GPU computing clusters have enabled accurate and reliable predictions of relative protein-ligand binding free energies through the free energy perturbation (FEP) methods. However, the existing FEP methods can only be used to calculate the relative binding free energies for R-group modifications or single-atom modifications and cannot be used to efficiently evaluate scaffold hopping modifications to a lead molecule. Scaffold hopping or core hopping, a very common design strategy in drug discovery projects, is critical not only in the early stages of a discovery campaign where novel active matter must be identified but also in lead optimization where the resolution of a variety of ADME/Tox problems may require identification of a novel core structure. In this paper, we introduce a method that enables theoretically rigorous, yet computationally tractable, relative protein-ligand binding free energy calculations to be pursued for scaffold hopping modifications. We apply the method to six pharmaceutically interesting cases where diverse types of scaffold hopping modifications were required to identify the drug molecules ultimately sent into the clinic. For these six diverse cases, the predicted binding affinities were in close agreement with experiment, demonstrating the wide applicability and the significant impact Core Hopping FEP may provide in drug discovery projects.

  3. Activation barrier scaling and crossover for noise-induced switching in micromechanical parametric oscillators.

    PubMed

    Chan, H B; Stambaugh, C

    2007-08-10

    We explore fluctuation-induced switching in parametrically driven micromechanical torsional oscillators. The oscillators possess one, two, or three stable attractors depending on the modulation frequency. Noise induces transitions between the coexisting attractors. Near the bifurcation points, the activation barriers are found to have a power law dependence on frequency detuning with critical exponents that are in agreement with predicted universal scaling relationships. At large detuning, we observe a crossover to a different power law dependence with an exponent that is device specific.

  4. Membrane-Bound ATPase Contributes to Hop Resistance of Lactobacillus brevis

    PubMed Central

    Sakamoto, Kanta; van Veen, H. W.; Saito, Hiromi; Kobayashi, Hiroshi; Konings, Wil N.

    2002-01-01

    The activity of the membrane-bound H+-ATPase of the beer spoilage bacterium Lactobacillus brevis ABBC45 increased upon adaptation to bacteriostatic hop compounds. The ATPase activity was optimal around pH 5.6 and increased up to fourfold when L. brevis was exposed to 666 μM hop compounds. The extent of activation depended on the concentration of hop compounds and was maximal at the highest concentration tested. The ATPase activity was strongly inhibited by N,N′-dicyclohexylcarbodiimide, a known inhibitor of FoF1-ATPase. Western blots of membrane proteins of L. brevis with antisera raised against the α- and β-subunits of FoF1-ATPase from Enterococcus hirae showed that there was increased expression of the ATPase after hop adaptation. The expression levels, as well as the ATPase activity, decreased to the initial nonadapted levels when the hop-adapted cells were cultured further without hop compounds. These observations strongly indicate that proton pumping by the membrane-bound ATPase contributes considerably to the resistance of L. brevis to hop compounds. PMID:12406727

  5. Membrane-bound ATPase contributes to hop resistance of Lactobacillus brevis.

    PubMed

    Sakamoto, Kanta; Van Veen, H W; Saito, Hiromi; Kobayashi, Hiroshi; Konings, Wil N

    2002-11-01

    The activity of the membrane-bound H+-ATPase of the beer spoilage bacterium Lactobacillus brevis ABBC45 increased upon adaptation to bacteriostatic hop compounds. The ATPase activity was optimal around pH 5.6 and increased up to fourfold when L. brevis was exposed to 666 microM hop compounds. The extent of activation depended on the concentration of hop compounds and was maximal at the highest concentration tested. The ATPase activity was strongly inhibited by N,N'-dicyclohexylcarbodiimide, a known inhibitor of FoF1-ATPase. Western blots of membrane proteins of L. brevis with antisera raised against the alpha- and beta-subunits of FoF1-ATPase from Enterococcus hirae showed that there was increased expression of the ATPase after hop adaptation. The expression levels, as well as the ATPase activity, decreased to the initial nonadapted levels when the hop-adapted cells were cultured further without hop compounds. These observations strongly indicate that proton pumping by the membrane-bound ATPase contributes considerably to the resistance of L. brevis to hop compounds.

  6. The HopZ family of Pseudomonas syringae type III effectors require myristoylation for virulence and avirulence functions in Arabidopsis thaliana.

    PubMed

    Lewis, Jennifer D; Abada, Wasan; Ma, Wenbo; Guttman, David S; Desveaux, Darrell

    2008-04-01

    Pseudomonas syringae utilizes the type III secretion system to translocate effector proteins into plant cells, where they can contribute to the pathogen's ability to infect and cause disease. Recognition of these effectors by resistance proteins induces defense responses that typically include a programmed cell death reaction called the hypersensitive response. The YopJ/HopZ family of type III effector proteins is a common family of effector proteins found in animal- and plant-pathogenic bacteria. The HopZ family in P. syringae includes HopZ1a(PsyA2), HopZ1b(PgyUnB647), HopZ1c(PmaE54326), HopZ2(Ppi895A) and HopZ3(PsyB728a). HopZ1a is predicted to be most similar to the ancestral hopZ allele and causes a hypersensitive response in multiple plant species, including Arabidopsis thaliana. Therefore, it has been proposed that host defense responses have driven the diversification of this effector family. In this study, we further characterized the hypersensitive response induced by HopZ1a and demonstrated that it is not dependent on known resistance genes. Further, we identified a novel virulence function for HopZ2 that requires the catalytic cysteine demonstrated to be required for protease activity. Sequence analysis of the HopZ family revealed the presence of a predicted myristoylation sequence in all members except HopZ3. We demonstrated that the myristoylation site is required for membrane localization of this effector family and contributes to the virulence and avirulence activities of HopZ2 and HopZ1a, respectively. This paper provides insight into the selective pressures driving virulence protein evolution by describing a detailed functional characterization of the diverse HopZ family of type III effectors with the model plant Arabidopsis.

  7. The HopZ Family of Pseudomonas syringae Type III Effectors Require Myristoylation for Virulence and Avirulence Functions in Arabidopsis thaliana▿ †

    PubMed Central

    Lewis, Jennifer D.; Abada, Wasan; Ma, Wenbo; Guttman, David S.; Desveaux, Darrell

    2008-01-01

    Pseudomonas syringae utilizes the type III secretion system to translocate effector proteins into plant cells, where they can contribute to the pathogen's ability to infect and cause disease. Recognition of these effectors by resistance proteins induces defense responses that typically include a programmed cell death reaction called the hypersensitive response. The YopJ/HopZ family of type III effector proteins is a common family of effector proteins found in animal- and plant-pathogenic bacteria. The HopZ family in P. syringae includes HopZ1aPsyA2, HopZ1bPgyUnB647, HopZ1cPmaE54326, HopZ2Ppi895A and HopZ3PsyB728a. HopZ1a is predicted to be most similar to the ancestral hopZ allele and causes a hypersensitive response in multiple plant species, including Arabidopsis thaliana. Therefore, it has been proposed that host defense responses have driven the diversification of this effector family. In this study, we further characterized the hypersensitive response induced by HopZ1a and demonstrated that it is not dependent on known resistance genes. Further, we identified a novel virulence function for HopZ2 that requires the catalytic cysteine demonstrated to be required for protease activity. Sequence analysis of the HopZ family revealed the presence of a predicted myristoylation sequence in all members except HopZ3. We demonstrated that the myristoylation site is required for membrane localization of this effector family and contributes to the virulence and avirulence activities of HopZ2 and HopZ1a, respectively. This paper provides insight into the selective pressures driving virulence protein evolution by describing a detailed functional characterization of the diverse HopZ family of type III effectors with the model plant Arabidopsis. PMID:18263728

  8. Probing radiation damage by alternated current conductivity as a method to characterize electron hopping conduction in DNA molecules

    SciTech Connect

    Gomes, Paulo J.; Coelho, Margarida; Antonio Ribeiro, Paulo; Raposo, Maria; Dionisio, Madalena

    2012-09-17

    Analysis of AC electrical conductivity of deoxyribonucleic acid (DNA) thin films, irradiated with ultraviolet (UV) light, revealed that electrical conduction arises from DNA chain electron hopping between base-pairs and phosphate groups. The hopping distance calculated from correlated barrier hopping model equals the distance between DNA base-pairs, which is consistent with the loss of conductivity with irradiation time arising from a decrease in phosphates groups. In the high frequency regime, at a given frequency, real part of conductivity strongly depends on irradiation time particularly for low dose levels suggesting the use of DNA based films for UV radiation sensors.

  9. Physical activity perceptions, context, barriers, and facilitators from a Hispanic child's perspective

    PubMed Central

    Ross, Sharon E. Taverno; Francis, Lori A.

    2016-01-01

    Background In order to develop effective physical activity interventions and to address the burden of obesity in Hispanic children, qualitative studies are needed to build descriptive theory and expand the state of the science. The purpose of this study is to describe physical activity perceptions, context, facilitators, and barriers from the perspective of Hispanic immigrant-origin children. Method This in-depth, ethnographic study included 14, 6- to 11-year old, first- and second- generation Hispanic children recruited from an afterschool program in Southeastern Pennsylvania, USA. Methods included child observation, field notes, semi-structured interviews, and a PhotoVoice activity. Transcripts and field notes were coded and analyzed using the constant comparison method to identify overarching themes and patterns in the data. Results Data analysis yielded four overarching themes regarding children's perspectives on physical activity. Children engaged in a variety of physical activities and sedentary behaviors, which differed by physical (e.g., park, outside home, and afterschool programs) and social (e.g., parents, siblings, and friends) contexts. Children discussed specific benefits of physical activity. Children's negative attitudes toward physical activity were related to physical discomfort, low athletic competence, and safety concerns. Children perceived physical activity and play to be one in the same, and “fun” was identified as a primary driver of physical activity preferences. The facilitators and barriers to physical activity were related to specific parent/home, school, and neighborhood factors. Conclusion Findings from this study suggest that an emphasis on fun and active play, while taking into account family and neighborhood context, may be a desirable intervention approach in Hispanic immigrant-origin children. This study lays the groundwork for future studies to further explore some of the themes identified here to better understand children

  10. Ehrlich-Schwöbel barriers and adsorption of Au, Cu and Ag stepped (100) surfaces

    NASA Astrophysics Data System (ADS)

    Benlattar, M.; Elkoraychy, E.; Sbiaai, K.; Mazroui, M.; Boughaleb, Y.

    2017-02-01

    We use a combination of quenched molecular dynamics and embedded atom method to calculate the activation energy barriers for the hopping and exchange mechanisms of Au, Ag or Cu on Au(100), Ag(100) or Cu(100) stepped surfaces. Our findings show that the Ehrlich-Schwöbel (ES) barriers for an adatom to undergo jump or exchange at a step edge are found to be dependent of the nature of substrate stepped surfaces. We also find that the ES barriers for the hopping processes are too high, except for Cu/Au(100). While for exchange process the Ehrlich-Schwöbel barriers are found to be very low and even negative. These ES barriers can explain the difference in the growth modes for the different systems. On the other hand, we calculated the adsorption energies at the most stable adsorption sites near step edges. In particular, we wish to clarify the relation between the adatom diffusion energy barriers and the adatom adsorption energies. These results may serve as some guiding rules for studying stepped surface morphologies, which are of importance to surface nanoengineering.

  11. Capturing local atomic environment dependence of activation barriers in metals using cluster expansion models

    NASA Astrophysics Data System (ADS)

    Kulkarni, Nimish; Chatterjee, Abhijit

    2016-10-01

    It is well known that surface diffusion in metals can proceed via multiple mechanisms, such as hop, exchange and other types of concerted moves. However, the manner in which kinetic rates associated with a mechanism can depend sensitively on local atomic environment is relatively less understood. We describe recent attempts in our research group to capture the atomic environment dependence using the cluster expansion model (CEM). In particular, we focus on hop and exchange moves at the (001) surface in homoepitaxy, and show that while CEM can work remarkably well in most cases, it can sometimes provide inaccurate predictions for concerted moves.

  12. Polyphenol-Rich Propolis Extracts Strengthen Intestinal Barrier Function by Activating AMPK and ERK Signaling.

    PubMed

    Wang, Kai; Jin, Xiaolu; Chen, Yifan; Song, Zehe; Jiang, Xiasen; Hu, Fuliang; Conlon, Michael A; Topping, David L

    2016-05-07

    Propolis has abundant polyphenolic constituents and is used widely as a health/functional food. Here, we investigated the effects of polyphenol-rich propolis extracts (PPE) on intestinal barrier function in human intestinal epithelial Caco-2 cells, as well as in rats. In Caco-2 cells, PPE increased transepithelial electrical resistance and decreased lucifer yellow flux. PPE-treated cells showed increased expression of the tight junction (TJ) loci occludin and zona occludens (ZO)-1. Confocal microscopy showed organized expressions in proteins related to TJ assembly, i.e., occludin and ZO-1, in response to PPE. Furthermore, PPE led to the activation of AMPK, ERK1/2, p38, and Akt. Using selective inhibitors, we found that the positive effects of PPE on barrier function were abolished in cells in which AMPK and ERK1/2 signaling were inhibited. Moreover, rats fed a diet supplemented with PPE (0.3% in the diet) exhibited increased colonic epithelium ZO-1 expression. Overall, these data suggest that PPE strengthens intestinal barrier function by activating AMPK and ERK signaling and provide novel insights into the potential application of propolis for human gut health.

  13. Polyphenol-Rich Propolis Extracts Strengthen Intestinal Barrier Function by Activating AMPK and ERK Signaling

    PubMed Central

    Wang, Kai; Jin, Xiaolu; Chen, Yifan; Song, Zehe; Jiang, Xiasen; Hu, Fuliang; Conlon, Michael A.; Topping, David L.

    2016-01-01

    Propolis has abundant polyphenolic constituents and is used widely as a health/functional food. Here, we investigated the effects of polyphenol-rich propolis extracts (PPE) on intestinal barrier function in human intestinal epithelial Caco-2 cells, as well as in rats. In Caco-2 cells, PPE increased transepithelial electrical resistance and decreased lucifer yellow flux. PPE-treated cells showed increased expression of the tight junction (TJ) loci occludin and zona occludens (ZO)-1. Confocal microscopy showed organized expressions in proteins related to TJ assembly, i.e., occludin and ZO-1, in response to PPE. Furthermore, PPE led to the activation of AMPK, ERK1/2, p38, and Akt. Using selective inhibitors, we found that the positive effects of PPE on barrier function were abolished in cells in which AMPK and ERK1/2 signaling were inhibited. Moreover, rats fed a diet supplemented with PPE (0.3% in the diet) exhibited increased colonic epithelium ZO-1 expression. Overall, these data suggest that PPE strengthens intestinal barrier function by activating AMPK and ERK signaling and provide novel insights into the potential application of propolis for human gut health. PMID:27164138

  14. Safety assessment of discharge chute isolation barrier preparation and installation activities. Revision 3

    SciTech Connect

    Meichle, R.H.

    1994-11-08

    This revision adds a section addressing impacts of dropping surfacing tool and rack cutter on the basin floor, and corrects typographical errors. The safety assessment is made for the activities for the preparation and installation of the discharge chute isolation barriers. The safety assessment includes a hazard assessment and comparisons of potential accidents/events to those addressed by the current safety basis documentation. No significant hazards were identified. An evaluation against the USQ evaluation questions was made and the determination made that the activities do not represent a USQ. Hazard categorization techniques were used to provide a basis for readiness review classifications.

  15. Activated barrier crossing dynamics in the non-radiative decay of NADH and NADPH

    NASA Astrophysics Data System (ADS)

    Blacker, Thomas S.; Marsh, Richard J.; Duchen, Michael R.; Bain, Angus J.

    2013-08-01

    In live tissue, alterations in metabolism induce changes in the fluorescence decay of the biological coenzyme NAD(P)H, the mechanism of which is not well understood. In this work, the fluorescence and anisotropy decay dynamics of NADH and NADPH were investigated as a function of viscosity in a range of water-glycerol solutions. The viscosity dependence of the non-radiative decay is well described by Kramers and Kramers-Hubbard models of activated barrier crossing over a wide viscosity range. Our combined lifetime and anisotropy analysis indicates common mechanisms of non-radiative relaxation in the two emitting states (conformations) of both molecules. The low frequencies associated with barrier crossing suggest that non-radiative decay is mediated by small scale motion (e.g. puckering) of the nicotinamide ring. Variations in the fluorescence lifetimes of NADH and NADPH when bound to different enzymes may therefore be attributed to differing levels of conformational restriction upon binding.

  16. Complete Genome Sequence of a Hop Latent Virus Infecting Hop Plants

    PubMed Central

    Jo, Yeonhwa; Choi, Hoseong

    2015-01-01

    The hop latent virus is a single-stranded RNA virus that mainly infects hop plants. Here, we report the complete genome sequence of a hop latent virus, which was de novo assembled by RNA sequencing (RNA-seq). Our study indicates that transcriptome data are useful for identifying a complete viral genome. PMID:25908127

  17. Storm surge forecasting for operating the Venice Flood Barrier with minimal impact on port activities

    NASA Astrophysics Data System (ADS)

    Cecconi, Giovanni

    2015-04-01

    The operation of the Venice storm barrier, due to enter into operation by the end of 2017 , is particularly demanding in terms of the required accuracy of the forecast of the max water level for the time lead of 3-6 hours. With present sea level and safeguard level established at 1.1 m a.s.l. of 1895 the barrier is expected to be operated 10 times a year to cope with an average of 5 storms with around 15 redirections of the navigation through the locks. The 5 extra closures and the 10 extra interferences with navigation are needed for compensating the present forecast uncertainty of 10 cm in the maximum storm high for the required time lead of three hours, the time needed to stop navigation before the closures of the lagoon inlets. A decision support system based on these rules have been tested along the last four year with satisfactory results in term of reliability easy of operations. The forecast is presently based on a statistical model associated with a deterministic local model; the main source of uncertainty is related to the prediction of the local wind. Due to delays in the completion of Venice local protection till 1.1 m it is expected that the population will urge a reduction of the safeguard level from 1.1m to 0.9m with an exponential increase in the number of closures with greater impact on navigation. The present acceleration in sea level rise will also contribute to the increase in the number of closures. To reduce the impact on port activity, better forecast accuracy is required together with experimenting new operational closures : e.g. activating only the northern barriers. The paper evaluate the problem and the possible solutions in terms of improving storm surge forecast and developing new schemes for partial operation of the barriers for predicted limited floods not requiring complete closures.

  18. Influence of sportive activity on skin barrier function: a quantitative evaluation of 60 athletes.

    PubMed

    Luebberding, Stefanie; Kolbe, Lea; Kerscher, Martina

    2013-06-01

    While sports-related diseases are well documented in the literature, no study regarding the physiology of athlete's skin has been published yet. However, some evidence is given for impairment of the skin barrier due to sportive activity accompanied by an increase in sweating. In this explorative study, we investigated the effect of sportive activity on skin physiology, namely stratum corneum hydration, skin surface pH, and sebum content. A total of 60 healthy Caucasian volunteers (35 females, 25 males; mean 27.35 ± 4.09) were enrolled in this study. Measurements were done before and after 45 minutes of endurance cardio training at forehead, chest, forearm, and armpits. Hydration level, sebum secretion, and pH value of hydrolipid acid film were measured with worldwide-acknowledged biophysical measuring methods. Stratum corneum hydration significantly increased after sportive activity. The increase was about 51.9% at the forearm and 31.9% at the chest. Sebum content at the forehead significantly decreased during exercising, from 87.36 μg/cm2 to 62.41 μg/cm2. At all investigated body sites, measured values for skin surface pH increased after sportive activity. Highest pH value was measured in armpits (pH 5.64-5.98) and lowest at forearm (pH 4.75-4.93). Sportive activity is accompanied by significant changes of skin physiology that could stress the barrier function of the skin. Higher skin surface pH and hyperhydration of the stratum corneum as well as increased lipid content on the skin surface are probably caused by an increased sweat production. The impaired skin barrier may also be the reason for some reported sports-related dermatoses.

  19. The dynamic limits of hop height: Biological actuator capabilities and mechanical requirements of task produce incongruity between one- and two-legged performance.

    PubMed

    Gutmann, Anne K; Bertram, John Ea

    2016-03-01

    The maximum hop height attainable for a given hop frequency falls well below the theoretical limit dictated by gravity, h = g/8f(2). However, maximum hop height is proportional to 1/f(2), suggesting that ground reaction force and, hence, force production capabilities of the leg muscles limit human hopping performance. Curiously, during one-legged hopping, subjects were able to produce substantially more than 50% the ground reaction force produced during two-legged maximum height hopping-66% on average and as much as 90% the total force produced during two-legged hopping. This implies that two legs together should be able to produce an average of 1.32 times and as much as 1.8 times the force actually measured during two-legged maximum height hopping. Why were our subjects unable to access this extra force capacity when hopping on two legs? Here, we show that this apparent bilateral deficit and other features of maximum height hopping can be explained by the interaction of the mechanical requirements of hopping with the force-velocity and force-length relationships that dictate the force production capacity of the leg muscles. Identifying the factors that limit performance in hopping provides an opportunity to understand how functional limits are determined in more complex activities such as running and jumping.

  20. I Feel What He Was Doin': Responding to Justice-Oriented Teaching through Hip-Hop Aesthetics

    ERIC Educational Resources Information Center

    Petchauer, Emery

    2011-01-01

    This study illustrates a set of learning activities designed from two hip-hop aesthetics and explores their use among a classroom of African American preservice teachers who graduated from urban school districts. Based on the two hip-hop aesthetics of kinetic consumption and autonomy/distance, the specific goal of these learning activities is to…

  1. 16. VIEW OF OVERHEAD DOOR TO HOP DRYER NO. 3. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VIEW OF OVERHEAD DOOR TO HOP DRYER NO. 3. ALL EIGHT HOP DRYERS ARE ON THE SECOND FLOOR. - James W. Seavey Hop Driers, 0.6 mile East from junction of Highway 99 & Alexander Avenue, Corvallis, Benton County, OR

  2. Analytical methods for quantitation of prenylated flavonoids from hops.

    PubMed

    Nikolić, Dejan; van Breemen, Richard B

    2013-01-01

    The female flowers of hops (Humulus lupulus L.) are used as a flavoring agent in the brewing industry. There is growing interest in possible health benefits of hops, particularly as estrogenic and chemopreventive agents. Among the possible active constituents, most of the attention has focused on prenylated flavonoids, which can chemically be classified as prenylated chalcones and prenylated flavanones. Among chalcones, xanthohumol (XN) and desmethylxanthohumol (DMX) have been the most studied, while among flavanones, 8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN) have received the most attention. Because of the interest in medicinal properties of prenylated flavonoids, there is demand for accurate, reproducible and sensitive analytical methods to quantify these compounds in various matrices. Such methods are needed, for example, for quality control and standardization of hop extracts, measurement of the content of prenylated flavonoids in beer, and to determine pharmacokinetic properties of prenylated flavonoids in animals and humans. This review summarizes currently available analytical methods for quantitative analysis of the major prenylated flavonoids, with an emphasis on the LC-MS and LC-MS-MS methods and their recent applications to biomedical research on hops. This review covers all methods in which prenylated flavonoids have been measured, either as the primary analytes or as a part of a larger group of analytes. The review also discusses methodological issues relating to the quantitative analysis of these compounds regardless of the chosen analytical approach.

  3. Analytical methods for quantitation of prenylated flavonoids from hops

    PubMed Central

    Nikolić, Dejan; van Breemen, Richard B.

    2013-01-01

    The female flowers of hops (Humulus lupulus L.) are used as a flavoring agent in the brewing industry. There is growing interest in possible health benefits of hops, particularly as estrogenic and chemopreventive agents. Among the possible active constituents, most of the attention has focused on prenylated flavonoids, which can chemically be classified as prenylated chalcones and prenylated flavanones. Among chalcones, xanthohumol (XN) and desmethylxanthohumol (DMX) have been the most studied, while among flavanones, 8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN) have received the most attention. Because of the interest in medicinal properties of prenylated flavonoids, there is demand for accurate, reproducible and sensitive analytical methods to quantify these compounds in various matrices. Such methods are needed, for example, for quality control and standardization of hop extracts, measurement of the content of prenylated flavonoids in beer, and to determine pharmacokinetic properties of prenylated flavonoids in animals and humans. This review summarizes currently available analytical methods for quantitative analysis of the major prenylated flavonoids, with an emphasis on the LC-MS and LC-MS-MS methods and their recent applications to biomedical research on hops. This review covers all methods in which prenylated flavonoids have been measured, either as the primary analytes or as a part of a larger group of analytes. The review also discusses methodological issues relating to the quantitative analysis of these compounds regardless of the chosen analytical approach. PMID:24077106

  4. Pseudomonas syringae type III effector HopAF1 suppresses plant immunity by targeting methionine recycling to block ethylene induction

    PubMed Central

    Washington, Erica J.; Mukhtar, M. Shahid; Finkel, Omri M.; Wan, Li; Kieber, Joseph J.; Dangl, Jeffery L.

    2016-01-01

    HopAF1 is a type III effector protein of unknown function encoded in the genomes of several strains of Pseudomonas syringae and other plant pathogens. Structural modeling predicted that HopAF1 is closely related to deamidase proteins. Deamidation is the irreversible substitution of an amide group with a carboxylate group. Several bacterial virulence factors are deamidases that manipulate the activity of specific host protein substrates. We identified Arabidopsis methylthioadenosine nucleosidase proteins MTN1 and MTN2 as putative targets of HopAF1 deamidation. MTNs are enzymes in the Yang cycle, which is essential for the high levels of ethylene biosynthesis in Arabidopsis. We hypothesized that HopAF1 inhibits the host defense response by manipulating MTN activity and consequently ethylene levels. We determined that bacterially delivered HopAF1 inhibits ethylene biosynthesis induced by pathogen-associated molecular patterns and that Arabidopsis mtn1 mtn2 mutant plants phenocopy the effect of HopAF1. Furthermore, we identified two conserved asparagines in MTN1 and MTN2 from Arabidopsis that confer loss of function phenotypes when deamidated via site-specific mutation. These residues are potential targets of HopAF1 deamidation. HopAF1-mediated manipulation of Yang cycle MTN proteins is likely an evolutionarily conserved mechanism whereby HopAF1 orthologs from multiple plant pathogens contribute to disease in a large variety of plant hosts. PMID:27274076

  5. Bacterial pathogens activate plasminogen to breach tissue barriers and escape from innate immunity.

    PubMed

    Peetermans, Marijke; Vanassche, Thomas; Liesenborghs, Laurens; Lijnen, Roger H; Verhamme, Peter

    2016-11-01

    Both coagulation and fibrinolysis are tightly connected with the innate immune system. Infection and inflammation cause profound alterations in the otherwise well-controlled balance between coagulation and fibrinolysis. Many pathogenic bacteria directly exploit the host's hemostatic system to increase their virulence. Here, we review the capacity of bacteria to activate plasminogen. The resulting proteolytic activity allows them to breach tissue barriers and evade innate immune defense, thus promoting bacterial spreading. Yersinia pestis, streptococci of group A, C and G and Staphylococcus aureus produce a specific bacterial plasminogen activator. Moreover, surface plasminogen receptors play an established role in pneumococcal, borrelial and group B streptococcal infections. This review summarizes the mechanisms of bacterial activation of host plasminogen and the role of the fibrinolytic system in infections caused by these pathogens.

  6. Methane activation using noble gases in a dielectric barrier discharge reactor

    SciTech Connect

    Jo, Sungkwon; Hoon Lee, Dae; Seok Kang, Woo; Song, Young-Hoon

    2013-08-15

    The conversion of methane is measured in a planar-type dielectric barrier discharge reactor using three different noble gases—He, Ne, and Ar—as additives. The empirical results obtained clearly indicate that methane activation is considerably affected by thy type of noble gas used. Through 0-D calculations, the discharge parameters inside the reactor, i.e., electron temperature and electron density, are estimated using experiment results. A comparison of the discharge characteristics and experimental results shows that the electron temperature is an important factor in achieving high methane activation and the mixture with Ar gas shows the highest methane conversion. These results are constructed using the mechanisms of energy and charge transfer from excited and ionized noble gas atoms to methane molecules, considering the number density of active atoms of noble gases. Finally, electron temperatures obtained for gas mixtures having different reactant compositions and concentrations are analyzed to estimate methane activation.

  7. Hops

    MedlinePlus

    ... verapamil), chemotherapeutic agents (etoposide, paclitaxel, vinblastine, vincristine, vindesine), antifungals (ketoconazole, itraconazole), glucocorticoids, alfentanil (Alfenta), cisapride (Propulsid), fentanyl ( ...

  8. No evidence hip joint angle modulates intrinsically produced stretch reflex in human hopping.

    PubMed

    Gibson, W; Campbell, A; Allison, G

    2013-09-01

    Motor output in activities such as walking and hopping is suggested to be mediated neurally by purported stretch reflex augmentation of muscle output. Reflex EMG activity during these tasks has been frequently investigated in the soleus muscle; with alterations in reflex amplitude being associated with changes in hip joint angle/phase of the gait cycle. Previous work has focussed on reflex activity induced by an artificial perturbation or by induction of H-reflexes. As such, it is currently unknown if stretch reflex activity induced intrinsically (as part of the task) is modulated by changes in hip joint angle. This study investigated whether hip joint angle modulated reflex EMG 'burst' activity during a hopping task performed on a custom-built partially reclined sleigh. Ten subjects participated; EMG and kinematic data (VICON motor capture system) was collected for each hop cycle. Participants completed 5 sets of 30s of self-paced hopping in (1) hip neutral and (2) hip 60° flexion conditions. There was no difference in EMG 'burst' activity or in sagittal plane kinematics (knee/ankle) in the hopping task between the two conditions. The results indicate that during a functional task such as hopping, changes in hip angle do not alter the stretch reflex-like activity associated with landing.

  9. Barriers to and enablers of physical activity in patients with COPD following a hospital admission: a qualitative study

    PubMed Central

    Thorpe, Olivia; Kumar, Saravana; Johnston, Kylie

    2014-01-01

    Background Chronic obstructive pulmonary disease (COPD) is characterized by a persistent blockage of airflow, prompting episodes of shortness of breath, commonly leading to hospitalization. Hospitalization may lead to a decline in physical activity following discharge. Physical activity has been shown to improve symptoms of COPD and reduce readmissions, and to decrease morbidity and mortality. This study aims to explore, from the perspectives of people with COPD, the barriers to and enablers of participation in physical activity following hospitalization for COPD. Methods This study had a qualitative descriptive design and included semistructured interviews with 28 adult COPD patients who had been admitted to hospital with a primary diagnosis of exacerbation of COPD. Results A plethora of barriers to but fewer enablers of participation in physical activity and pulmonary rehabilitation were identified for this cohort of people. The main barriers identified were health-related (comorbidities, COPD symptoms, and physical injury or illness) environment-related (weather, transport, and finance), and self-related. The main enabling factors reported were access to health professionals and equipment, social support, routine and extracurricular activities, personal goals and motivation, and the effect of physical activity and “feeling better”. Conclusion This research provides a snapshot of the barriers to and enablers of physical activity and pulmonary rehabilitation in people with COPD. It is evident that there are significant barriers which hinder the ability of people with COPD to undertake and continue participation in physical activity and pulmonary rehabilitation. While there are some enablers that may counter these barriers, it is clear that health professionals dealing with people suffering from COPD need to actively recognize and address barriers to physical activity and pulmonary rehabilitation. Hospital admission may create an opportunity for implementation

  10. Barriers and Facilitators to Being Physically Active on a Rural U.S. Northern Plains American Indian Reservation

    PubMed Central

    Jahns, Lisa; McDonald, Leander R.; Wadsworth, Ann; Morin, Charles; Liu, Yan

    2014-01-01

    The objective of the present study was to identify barriers to and facilitators of physical activity among American Indian adults living on a rural, U.S. Northern Plains reservation using the nominal group technique (NGT). NGT is a method of data generation and interpretation that combines aspects of qualitative (free generation of responses) and quantitative (systematic ranking of responses) methodologies. Adults participated in one of two NGT sessions asking about either barriers to (n = 6), or facilitators of (n = 5), being physically active. Participants nominated and ranked 21 barriers and 18 facilitators. Barriers indicated lack of knowledge of how to fit physical activity into a daily schedule, work, caring for family members, and prioritizing sedentary pursuits. Other responses included environmental barriers such as lack of access and transportation to a gym, unsafe walking conditions, and inclement weather. Facilitators to following recommendations included knowledge of health benefits of physical activity and the perception of physical activity as enjoyable, including feeling good when working out. Environmental facilitators included being outdoors walking and biking as well as parks and exercise facilities. Responses provided direction for locally designed community-based programs to promote facilitators and decrease barriers to individual’s engagement in physical activity. PMID:25421064

  11. How Does a Hopping Kangaroo Breathe?

    ERIC Educational Resources Information Center

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Janbaih, Hussein; DiCarlo, Stephen E.

    2010-01-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

  12. Compendium of Hop Diseases and Pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This compendium of diseases, pests and other disorders of hop (Humulus lupulus L.) is designed to be a practical reference for anyone interested in growing hops, whether for commercial production, ornamental or home use. Growers, crop advisors, private consultants, home brewers, students, extension...

  13. Quantitative structure-activation barrier relationship modeling for Diels-Alder ligations utilizing quantum chemical structural descriptors

    PubMed Central

    2013-01-01

    Background In the present study, we show the correlation of quantum chemical structural descriptors with the activation barriers of the Diels-Alder ligations. A set of 72 non-catalysed Diels-Alder reactions were subjected to quantitative structure-activation barrier relationship (QSABR) under the framework of theoretical quantum chemical descriptors calculated solely from the structures of diene and dienophile reactants. Experimental activation barrier data were obtained from literature. Descriptors were computed using Hartree-Fock theory using 6-31G(d) basis set as implemented in Gaussian 09 software. Results Variable selection and model development were carried out by stepwise multiple linear regression methodology. Predictive performance of the quantitative structure-activation barrier relationship (QSABR) model was assessed by training and test set concept and by calculating leave-one-out cross-validated Q2 and predictive R2 values. The QSABR model can explain and predict 86.5% and 80% of the variances, respectively, in the activation energy barrier training data. Alternatively, a neural network model based on back propagation of errors was developed to assess the nonlinearity of the sought correlations between theoretical descriptors and experimental reaction barriers. Conclusions A reasonable predictability for the activation barrier of the test set reactions was obtained, which enabled an exploration and interpretation of the significant variables responsible for Diels-Alder interaction between dienes and dienophiles. Thus, studies in the direction of QSABR modelling that provide efficient and fast prediction of activation barriers of the Diels-Alder reactions turn out to be a meaningful alternative to transition state theory based computation. PMID:24171724

  14. VE-cadherin trans-interactions modulate Rac activation and enhancement of lung endothelial barrier by iloprost.

    PubMed

    Birukova, Anna A; Tian, Yufeng; Dubrovskyi, Oleksii; Zebda, Noureddine; Sarich, Nicolene; Tian, Xinyong; Wang, Yingxiao; Birukov, Konstantin G

    2012-10-01

    Small GTPase Rac is important regulator of endothelial cell (EC) barrier enhancement by prostacyclin characterized by increased peripheral actin cytoskeleton and increased interactions between VE-cadherin and other adherens junction (AJ) proteins. This study utilized complementary approaches including siRNA knockdown, culturing in Ca(2+) -free medium, and VE-cadherin blocking antibody to alter VE-cadherin extracellular interactions to investigate the role of VE-cadherin outside-in signaling in modulation of Rac activation and EC barrier regulation by prostacyclin analog iloprost. Spatial analysis of Rac activation in pulmonary EC by FRET revealed additional spike in iloprost-induced Rac activity at the sites of newly formed cell-cell junctions. In contrast, disruption of VE-cadherin extracellular trans-interactions suppressed iloprost-activated Rac signaling and attenuated EC barrier enhancement and cytoskeletal remodeling. These inhibitory effects were associated with decreased membrane accumulation and activation of Rac-specific guanine nucleotide exchange factors (GEFs) Tiam1 and Vav2. Conversely, plating of pulmonary EC on surfaces coated with extracellular VE-cadherin domain further promoted iloprost-induced Rac signaling. In the model of thrombin-induced EC barrier recovery, blocking of VE-cadherin trans-interactions attenuated activation of Rac pathway during recovery phase and delayed suppression of Rho signaling and restoration of EC barrier properties. These results suggest that VE-cadherin outside-in signaling controls locally Rac activity stimulated by barrier protective agonists. This control is essential for maximal EC barrier enhancement and accelerated barrier recovery.

  15. Communications: Comparison of activation barriers for the Johari-Goldstein and alpha relaxations and its implications.

    PubMed

    Goldstein, Martin

    2010-01-28

    The range of activation barrier heights for the Johari-Goldstein (JG) relaxation in glasses is shown to overlap the range for the main (alpha) relaxation, but to be on the average somewhat lower. This suggests the JG relaxation, like the alpha, involve transitions between megabasins in the energy landscape, and that the original conjecture by Johari and this author that the JG relaxation is an intrabasin one cannot be correct. A further possibility is that there is a closer connection of the JG relaxation to the phenomenon of dynamic heterogeneity in supercooled liquids than so far assumed.

  16. On transition rates in surface hopping

    NASA Astrophysics Data System (ADS)

    Escartín, J. M.; Romaniello, P.; Stella, L.; Reinhard, P.-G.; Suraud, E.

    2012-12-01

    Trajectory surface hopping (TSH) is one of the most widely used quantum-classical algorithms for nonadiabatic molecular dynamics. Despite its empirical effectiveness and popularity, a rigorous derivation of TSH as the classical limit of a combined quantum electron-nuclear dynamics is still missing. In this work, we aim to elucidate the theoretical basis for the widely used hopping rules. Naturally, we concentrate thereby on the formal aspects of the TSH. Using a Gaussian wave packet limit, we derive the transition rates governing the hopping process at a simple avoided level crossing. In this derivation, which gives insight into the physics underlying the hopping process, some essential features of the standard TSH algorithm are retrieved, namely (i) non-zero electronic transition rate ("hopping probability") at avoided crossings; (ii) rescaling of the nuclear velocities to conserve total energy; (iii) electronic transition rates linear in the nonadiabatic coupling vectors. The well-known Landau-Zener model is then used for illustration.

  17. Modulation of Rac1 Activity by ADMA/DDAH Regulates Pulmonary Endothelial Barrier Function

    PubMed Central

    Torondel, Belen; Zhao, Lan; Renné, Thomas; Leiper, James M.

    2009-01-01

    Endogenously produced nitric oxide synthase inhibitor, asymmetric methylarginine (ADMA) is associated with vascular dysfunction and endothelial leakage. We studied the role of ADMA, and the enzymes metabolizing it, dimethylarginine dimethylaminohydrolases (DDAH) in the regulation of endothelial barrier function in pulmonary macrovascular and microvascular cells in vitro and in lungs of genetically modified heterozygous DDAHI knockout mice in vivo. We show that ADMA increases pulmonary endothelial permeability in vitro and in in vivo and that this effect is mediated by nitric oxide (NO) acting via protein kinase G (PKG) and independent of reactive oxygen species formation. ADMA-induced remodeling of actin cytoskeleton and intercellular adherens junctions results from a decrease in PKG-mediated phosphorylation of vasodilator-stimulated phosphoprotein (VASP) and a subsequent down-regulation of Rac1 activity. The effects of ADMA on endothelial permeability, Rac1 activation and VASP phosphorylation are prevented by overexpression of active DDAHI and DDAHII, whereas inactive DDAH mutants have no effect. These findings demonstrate for the first time that ADMA metabolism critically determines pulmonary endothelial barrier function by modulating Rac1-mediated remodeling of the actin cytoskeleton and intercellular junctions. PMID:18923147

  18. Characterization of a highly hop-resistant Lactobacillus brevis strain lacking hop transport.

    PubMed

    Behr, Jürgen; Gänzle, Michael G; Vogel, Rudi F

    2006-10-01

    Resistance to hops is a prerequisite for lactic acid bacteria to spoil beer. In this study we analyzed mechanisms of hop resistance of Lactobacillus brevis at the metabolism, membrane physiology, and cell wall composition levels. The beer-spoiling organism L. brevis TMW 1.465 was adapted to high concentrations of hop compounds and compared to a nonadapted strain. Upon adaptation to hops the metabolism changed to minimize ethanol stress. Fructose was used predominantly as a carbon source by the nonadapted strain but served as an electron acceptor upon adaptation to hops, with concomitant formation of acetate instead of ethanol. Furthermore, hop adaptation resulted in higher levels of lipoteichoic acids (LTA) incorporated into the cell wall and altered composition and fluidity of the cytoplasmic membrane. The putative transport protein HitA and enzymes of the arginine deiminase pathway were overexpressed upon hop adaptation. HorA was not expressed, and the transport of hop compounds from the membrane to the extracellular space did not account for increased resistance to hops upon adaptation. Accordingly, hop resistance is a multifactorial dynamic property, which can develop during adaptation. During hop adaptation, arginine catabolism contributes to energy and generation of the proton motive force until a small fraction of the population has established structural improvements. This acquired hop resistance is energy independent and involves an altered cell wall composition. LTA shields the organism from accompanying stresses and provides a reservoir of divalent cations, which are otherwise scarce as a result of their complexation by hop acids. Some of the mechanisms involved in hop resistance overlap with mechanisms of pH resistance and ethanol tolerance and as a result enable beer spoilage by L. brevis.

  19. Characterization of a Highly Hop-Resistant Lactobacillus brevis Strain Lacking Hop Transport

    PubMed Central

    Behr, Jürgen; Gänzle, Michael G.; Vogel, Rudi F.

    2006-01-01

    Resistance to hops is a prerequisite for lactic acid bacteria to spoil beer. In this study we analyzed mechanisms of hop resistance of Lactobacillus brevis at the metabolism, membrane physiology, and cell wall composition levels. The beer-spoiling organism L. brevis TMW 1.465 was adapted to high concentrations of hop compounds and compared to a nonadapted strain. Upon adaptation to hops the metabolism changed to minimize ethanol stress. Fructose was used predominantly as a carbon source by the nonadapted strain but served as an electron acceptor upon adaptation to hops, with concomitant formation of acetate instead of ethanol. Furthermore, hop adaptation resulted in higher levels of lipoteichoic acids (LTA) incorporated into the cell wall and altered composition and fluidity of the cytoplasmic membrane. The putative transport protein HitA and enzymes of the arginine deiminase pathway were overexpressed upon hop adaptation. HorA was not expressed, and the transport of hop compounds from the membrane to the extracellular space did not account for increased resistance to hops upon adaptation. Accordingly, hop resistance is a multifactorial dynamic property, which can develop during adaptation. During hop adaptation, arginine catabolism contributes to energy and generation of the proton motive force until a small fraction of the population has established structural improvements. This acquired hop resistance is energy independent and involves an altered cell wall composition. LTA shields the organism from accompanying stresses and provides a reservoir of divalent cations, which are otherwise scarce as a result of their complexation by hop acids. Some of the mechanisms involved in hop resistance overlap with mechanisms of pH resistance and ethanol tolerance and as a result enable beer spoilage by L. brevis. PMID:17021196

  20. Survey of the Relationship Between Activity Energy Expenditure Metabolic Equivalents and Barrier Factors of Physical Activity in the Elderly in Kashan

    PubMed Central

    Sadrollahi, Ali; Khalili, Zahra; Pour Nazari, Robab; Mohammadi, Majid; Ahmadi Khatir, Maryam; Mossadegh, Najima

    2016-01-01

    Background Physical activity in the elderly is influenced by aspects of aging that cause personal, mental, environmental, and social changes. Increases in factors that are barriers to activity cause physical energy expenditure to decrease. Objectives The aim of the present study was to survey the relationship between energy expenditure in metabolic equivalent units (MET) and factors that are barriers to physical activity in elderly people in Kashan, Iran Methods This is a descriptive analysis done in 2014. The study population was 400 people above 60 years old in medical facilities in Kashan. Multistage sampling was used in 10 clinics in 5 areas of Kashan. The sample size was varied according to gender and elderly population. Contributors were given questionnaires concerning energy expenditure levels in physical activity and factors that are barriers to being active. Results The average age among the study population was 67.6 ± 6.8 years median, and the interquartile range (IQR) of barriers to physical activity among Kashan’s elderly was (8.75) ± 33. Average energy expenditure was 326.21 ± 364.84 based on metabolic equivalent units (MET). In fact, 340 persons (85%) were practically without any active energy expenditure. The most common barrier was the lack of an appropriate place for doing physical activity; 298 (74%) of the participants cited this barrier. The results show the Spearman rank-order correlation is significant (P = 0.038, r = 0.104) between barriers to physical activity and activity energy expenditure in Kashan’s elderly. Conclusions Decreasing barriers to physical activity among the elderly causes physical activities to increase; therefore, energy expenditure is increased. Decreasing social and environmental problems for the elderly is effective in increasing physical activity and energy expenditure. PMID:28191341

  1. Methane activation using Kr and Xe in a dielectric barrier discharge reactor

    SciTech Connect

    Jo, Sungkwon; Lee, Dae Hoon Kim, Kwan-Tae; Kang, Woo Seok; Song, Young-Hoon

    2014-10-15

    Methane has interested many researchers as a possible new energy source, but the high stability of methane causes a bottleneck in methane activation, limiting its practical utilization. To determine how to effectively activate methane using non-thermal plasma, the conversion of methane is measured in a planar-type dielectric barrier discharge reactor using three different noble gases—Ar, Kr, and Xe—as additives. In addition to the methane conversion results at various applied voltages, the discharge characteristics such as electron temperature and electron density were calculated through zero-dimensional calculations. Moreover, the threshold energies of excitation and ionization were used to distinguish the dominant particle for activating methane between electrons, excited atoms, and ionized atoms. From the experiments and calculations, the selection of the additive noble gas is found to affect not only the conversion of methane but also the selectivity of product gases even under similar electron temperature and electron density conditions.

  2. RILP interacts with HOPS complex via VPS41 subunit to regulate endocytic trafficking.

    PubMed

    Lin, Xiaosi; Yang, Ting; Wang, Shicong; Wang, Zhen; Yun, Ye; Sun, Lixiang; Zhou, Yunhe; Xu, Xiaohui; Akazawa, Chihiro; Hong, Wanjin; Wang, Tuanlao

    2014-12-02

    The HOPS complex serves as a tethering complex with GEF activity for Ypt7p in yeast to regulate late endosomal membrane maturation. While the role of HOPS complex is well established in yeast cells, its functional and mechanistic aspects in mammalian cells are less well defined. In this study, we report that RILP, a downstream effector of Rab7, interacts with HOPS complex and recruits HOPS subunits to the late endosomal compartment. Structurally, the amino-terminal portion of RILP interacts with HOPS complex. Unexpectedly, this interaction is independent of Rab7. VPS41 subunit of HOPS complex was defined to be the major partner for interacting with RILP. The carboxyl-terminal region of VPS41 was mapped to be responsible for the interaction. Functionally, either depletion of VPS41 by shRNA or overexpression of VPS41 C-terminal half retarded EGF-induced degradation of EGFR. These results suggest that interaction of RILP with HOPS complex via VPS41 plays a role in endocytic trafficking of EGFR.

  3. Monitoring seasonal bat activity on a coastal barrier island in Maryland, USA.

    PubMed

    Johnson, Joshua B; Gates, J Edward; Zegre, Nicolas P

    2011-02-01

    Research on effects of wind turbines on bats has increased dramatically in recent years because of significant numbers of bats killed by rotating wind turbine blades. Whereas most research has focused on the Midwest and inland portions of eastern North America, bat activity and migration on the Atlantic Coast has largely been unexamined. We used three long-term acoustic monitoring stations to determine seasonal bat activity patterns on the Assateague Island National Seashore, a barrier island off the coast of Maryland, from 2005 to 2006. We recorded five species, including eastern red bats (Lasiurus borealis), big brown bats (Eptesicus fuscus), hoary bats (Lasiurus cinereus), tri-colored bats (Perimyotis subflavus), and silver-haired bats (Lasionycteris noctivagans). Seasonal bat activity (number of bat passes recorded) followed a cosine function and gradually increased beginning in April, peaked in August, and declined gradually until cessation in December. Based on autoregressive models, inter-night bat activity was autocorrelated for lags of seven nights or fewer but varied among acoustic monitoring stations. Higher nightly temperatures and lower wind speeds positively affected bat activity. When autoregressive model predictions were fitted to the observed nightly bat pass totals, model residuals>2 standard deviations from the mean existed only during migration periods, indicating that periodic increases in bat activity could not be accounted for by seasonal trends and weather variables alone. Rather, the additional bat passes were attributable to migrating bats. We conclude that bats, specifically eastern red, hoary, and silver-haired bats, use this barrier island during migration and that this phenomenon may have implications for the development of near and offshore wind energy.

  4. Gut Epithelial Barrier Dysfunction and Innate Immune Activation Predict Mortality in Treated HIV Infection

    PubMed Central

    Hunt, Peter W.; Sinclair, Elizabeth; Rodriguez, Benigno; Shive, Carey; Clagett, Brian; Funderburg, Nicholas; Robinson, Janet; Huang, Yong; Epling, Lorrie; Martin, Jeffrey N.; Deeks, Steven G.; Meinert, Curtis L.; Van Natta, Mark L.; Jabs, Douglas A.; Lederman, Michael M.

    2014-01-01

    Background. While inflammation predicts mortality in treated human immunodeficiency virus (HIV) infection, the prognostic significance of gut barrier dysfunction and phenotypic T-cell markers remains unclear. Methods. We assessed immunologic predictors of mortality in a case-control study within the Longitudinal Study of the Ocular Complications of AIDS (LSOCA), using conditional logistic regression. Sixty-four case patients who died within 12 months of treatment-mediated viral suppression were each matched to 2 control individuals (total number of controls, 128) by duration of antiretroviral therapy–mediated viral suppression, nadir CD4+ T-cell count, age, sex, and prior cytomegalovirus (CMV) retinitis. A similar secondary analysis was conducted in the SCOPE cohort, which had participants with less advanced immunodeficiency. Results. Plasma gut epithelial barrier integrity markers (intestinal fatty acid binding protein and zonulin-1 levels), soluble CD14 level, kynurenine/tryptophan ratio, soluble tumor necrosis factor receptor 1 level, high-sensitivity C-reactive protein level, and D-dimer level all strongly predicted mortality, even after adjustment for proximal CD4+ T-cell count (all P ≤ .001). A higher percentage of CD38+HLA-DR+ cells in the CD8+ T-cell population was a predictor of mortality before (P = .031) but not after (P = .10) adjustment for proximal CD4+ T-cell count. Frequencies of senescent (defined as CD28−CD57+ cells), exhausted (defined as PD1+ cells), naive, and CMV-specific T cells did not predict mortality. Conclusions. Gut epithelial barrier dysfunction, innate immune activation, inflammation, and coagulation—but not T-cell activation, senescence, and exhaustion—independently predict mortality in individuals with treated HIV infection with a history of AIDS and are viable targets for interventions. PMID:24755434

  5. Cardiolipins Act as a Selective Barrier to Toll-Like Receptor 4 Activation in the Intestine

    PubMed Central

    Coats, Stephen R.; Hashim, Ahmed; Paramonov, Nikolay A.; Curtis, Michael A.

    2016-01-01

    ABSTRACT Intestinal homeostasis mechanisms must protect the host intestinal tissue from endogenous lipopolysaccharides (LPSs) produced by the intestinal microbiota. In this report, we demonstrate that murine intestinal fecal lipids effectively block Toll-like receptor 4 (TLR4) responses to naturally occurring Bacteroidetes sp. LPS. Cardiolipin (CL) represents a significant proportion of the total intestinal and fecal lipids and, furthermore, potently antagonizes TLR4 activation by reducing LPS binding at the lipopolysaccharide binding protein (LBP), CD14, and MD-2 steps of the TLR4 signaling pathway. It is further demonstrated that intestinal lipids and CL are less effective at neutralizing more potent Enterobacteriaceae-type LPS, which is enriched in feces obtained from mice with dextran sodium sulfate (DSS)-treated inflammatory bowel disease. The selective inhibition of naturally occurring LPS structures by intestinal lipids may represent a novel homeostasis mechanism that blocks LPS activation in response to symbiotic but not dysbiotic microbial communities. IMPORTANCE The guts of animals harbor a variety of Gram-negative bacteria associated with both states of intestinal health and states of disease. Environmental factors, such as dietary habits, can drive the microbial composition of the host animal's intestinal bacterial community toward a more pathogenic state. Both beneficial and harmful Gram-negative bacteria are capable of eliciting potentially damaging inflammatory responses from the host intestinal tissues via a lipopolysaccharide (LPS)-dependent pathway. Physical mucosal barriers and antibodies produced by the intestinal immune system protect against the undesired inflammatory effects of LPS, although it is unknown why some bacteria are more effective at overcoming the protective barriers than others. This report describes the discovery of a lipid-type protective barrier in the intestine that reduces the deleterious effects of LPSs from beneficial

  6. First-principles multiple-barrier diffusion theory. The case study of interstitial diffusion in CdTe

    DOE PAGES

    Yang, Ji -Hui; Park, Ji -Sang; Kang, Joongoo; ...

    2015-02-17

    The diffusion of particles in solid-state materials generally involves several sequential thermal-activation processes. However, presently, diffusion coefficient theory only deals with a single barrier, i.e., it lacks an accurate description to deal with multiple-barrier diffusion. Here, we develop a general diffusion coefficient theory for multiple-barrier diffusion. Using our diffusion theory and first-principles calculated hopping rates for each barrier, we calculate the diffusion coefficients of Cd, Cu, Te, and Cl interstitials in CdTe for their full multiple-barrier diffusion pathways. As a result, we found that the calculated diffusivity agrees well with the experimental measurement, thus justifying our theory, which is generalmore » for many other systems.« less

  7. First-principles multiple-barrier diffusion theory. The case study of interstitial diffusion in CdTe

    SciTech Connect

    Yang, Ji -Hui; Park, Ji -Sang; Kang, Joongoo; Wei, Su -Huai

    2015-02-17

    The diffusion of particles in solid-state materials generally involves several sequential thermal-activation processes. However, presently, diffusion coefficient theory only deals with a single barrier, i.e., it lacks an accurate description to deal with multiple-barrier diffusion. Here, we develop a general diffusion coefficient theory for multiple-barrier diffusion. Using our diffusion theory and first-principles calculated hopping rates for each barrier, we calculate the diffusion coefficients of Cd, Cu, Te, and Cl interstitials in CdTe for their full multiple-barrier diffusion pathways. As a result, we found that the calculated diffusivity agrees well with the experimental measurement, thus justifying our theory, which is general for many other systems.

  8. Physical activity enjoyment, perceived barriers, and beliefs among adolescents with and without intellectual disabilities

    PubMed Central

    Stanish, Heidi I.; Curtin, Carol; Must, Aviva; Phillips, Sarah; Maslin, Melissa; Bandini, Linda G.

    2015-01-01

    Background Youth with intellectual disabilities (ID) exhibit low levels of physical activity, but the underlying contributors to behavior are unclear. We compared physical activity enjoyment, perceived barriers, beliefs, and self-efficacy among adolescents with ID and typically developing (TD) adolescents. Methods A questionnaire was administered to 38 adolescents with ID (mean age 16.8 years) and 60 TD adolescents (mean age 15.3 years). Of the original 33 questionnaire items, 23 met the test-retest reliability criteria and were included in the group comparisons. Results Fewer adolescents with ID reported that they have someone to do physical activity with (64% vs. 93%, p<0.001), and a greater proportion of adolescents with ID perceived that physical activities were too hard to learn (41% vs. 0%, p<0.001). Fewer adolescents with ID believed that physical activity is good for their health (92% vs. 100%, p=0.05). More adolescents with ID reported a dislike of individual physical activities (p=0.02). A large proportion of adolescents with ID (84%) responded that they were good at doing physical activities, but the difference between groups was only of borderline significance. (95% of TD adolescents, p=0.06). Conclusions Adolescents shared many of the same perceptions about physical activity, but some important differences between groups were identified. PMID:25830443

  9. Understanding Barriers and Facilitators to Healthy Eating and Active Living in Rural Communities

    PubMed Central

    Seguin, Rebecca; Nelson, Miriam; LaCroix, Andrea

    2014-01-01

    Objective. Studies demonstrate that people's food and physical activity (PA) environments influence behavior, yet research examining this in rural communities is limited. Methods. Focus groups of 8–15 women were conducted in rural communities in seven US states. Questions were designed to identify factors within residents' food and PA environments they felt helped or hindered them from eating healthfully and being physically active. Results. Participants were aged 30–84 years; mean (SD) = 61 (14) (N = 95). On average, communities had fewer than 5,000 residents. Limited time, social norms, and distances from or lack of exercise facilities were common PA barriers. Facilitators for PA included social support, dog walking, and availability of affordable facilities. Healthy eating barriers included the perception that healthy foods were too expensive; calorically dense large portion sizes served at family meals; and frequency of eating foods away from home, which were perceived as generally unhealthy. Healthy eating supports included culture/value around local food gathering (e.g., hunting and gardening) and preservation (e.g., canning and smoking). Friends and family were frequently identified as key influencers of eating and PA behavior. Conclusions. Targeting both social and built environment factors, particularly those unique to rural locales, may enhance support for healthy eating and PA behavior change interventions. PMID:25574386

  10. The Third Exon of the Budding Yeast Meiotic Recombination Gene HOP2 Is Required for Calcium-dependent and Recombinase Dmc1-specific Stimulation of Homologous Strand Assimilation*

    PubMed Central

    Chan, Yuen-Ling; Brown, M. Scott; Qin, Daoming; Handa, Naofumi; Bishop, Douglas K.

    2014-01-01

    During meiosis in Saccharomyces cerevisiae, the HOP2 and MND1 genes are essential for recombination. A previous biochemical study has shown that budding yeast Hop2-Mnd1 stimulates the activity of the meiosis-specific strand exchange protein ScDmc1 only 3-fold, whereas analogous studies using mammalian homologs show >30-fold stimulation. The HOP2 gene was recently discovered to contain a second intron that lies near the 3′-end. We show that both HOP2 introns are efficiently spliced during meiosis, forming a predominant transcript that codes for a protein with a C-terminal sequence different from that of the previously studied version of the protein. Using the newly identified HOP2 open reading frame to direct synthesis of wild type Hop2 protein, we show that the Hop2-Mnd1 heterodimer stimulated Dmc1 D-loop activity up to 30-fold, similar to the activity of mammalian Hop2-Mnd1. ScHop2-Mnd1 stimulated ScDmc1 activity in the presence of physiological (micromolar) concentrations of Ca2+ ions, as long as Mg2+ was also present at physiological concentrations, leading us to hypothesize that ScDmc1 protomers bind both cations in the active Dmc1 filament. Co-factor requirements and order-of-addition experiments suggested that Hop2-Mnd1-mediated stimulation of Dmc1 involves a process that follows the formation of functional Dmc1-ssDNA filaments. In dramatic contrast to mammalian orthologs, the stimulatory activity of budding yeast Hop2-Mnd1 appeared to be specific to Dmc1; we observed no Hop2-Mnd1-mediated stimulation of the other budding yeast strand exchange protein Rad51. Together, these results support previous genetic experiments indicating that Hop2-Mnd1 specifically stimulates Dmc1 during meiotic recombination in budding yeast. PMID:24798326

  11. The third exon of the budding yeast meiotic recombination gene HOP2 is required for calcium-dependent and recombinase Dmc1-specific stimulation of homologous strand assimilation.

    PubMed

    Chan, Yuen-Ling; Brown, M Scott; Qin, Daoming; Handa, Naofumi; Bishop, Douglas K

    2014-06-27

    During meiosis in Saccharomyces cerevisiae, the HOP2 and MND1 genes are essential for recombination. A previous biochemical study has shown that budding yeast Hop2-Mnd1 stimulates the activity of the meiosis-specific strand exchange protein ScDmc1 only 3-fold, whereas analogous studies using mammalian homologs show >30-fold stimulation. The HOP2 gene was recently discovered to contain a second intron that lies near the 3'-end. We show that both HOP2 introns are efficiently spliced during meiosis, forming a predominant transcript that codes for a protein with a C-terminal sequence different from that of the previously studied version of the protein. Using the newly identified HOP2 open reading frame to direct synthesis of wild type Hop2 protein, we show that the Hop2-Mnd1 heterodimer stimulated Dmc1 D-loop activity up to 30-fold, similar to the activity of mammalian Hop2-Mnd1. ScHop2-Mnd1 stimulated ScDmc1 activity in the presence of physiological (micromolar) concentrations of Ca(2+) ions, as long as Mg(2+) was also present at physiological concentrations, leading us to hypothesize that ScDmc1 protomers bind both cations in the active Dmc1 filament. Co-factor requirements and order-of-addition experiments suggested that Hop2-Mnd1-mediated stimulation of Dmc1 involves a process that follows the formation of functional Dmc1-ssDNA filaments. In dramatic contrast to mammalian orthologs, the stimulatory activity of budding yeast Hop2-Mnd1 appeared to be specific to Dmc1; we observed no Hop2-Mnd1-mediated stimulation of the other budding yeast strand exchange protein Rad51. Together, these results support previous genetic experiments indicating that Hop2-Mnd1 specifically stimulates Dmc1 during meiotic recombination in budding yeast.

  12. "I Don't Have Time": Barriers and Facilitators to Physical Activity for Adults With Intellectual Disabilities.

    PubMed

    Taliaferro, Andrea R; Hammond, Lindsay

    2016-04-01

    Individuals with intellectual disabilities (ID) tend to have low rates of participation in voluntary or prescribed physical activity. The purpose of this study, therefore, was to identify the barriers, facilitators, and needs influencing physical activity participation of adults with ID within the framework of a social ecological model. A qualitative approach consisted of data collected from surveys and guided focus groups. Participants included adults with ID (n = 6) and their primary caregiver (n = 6). Barriers were categorized under three themes: organizational barriers, individual constraints, and external influences. Examples of subthemes included information dissemination, reliance on others, and caregiver considerations. Facilitators included primary caregivers as champions and camaraderie. Needs centered on family program involvement, improved programmatic structure, and programmatic support. Results indicate the need for community programs to examine barriers and facilitators applicable to their unique setting and population across all levels of a social ecological model.

  13. Terpene biosynthesis in glandular trichomes of hop.

    PubMed

    Wang, Guodong; Tian, Li; Aziz, Naveed; Broun, Pierre; Dai, Xinbin; He, Ji; King, Andrew; Zhao, Patrick X; Dixon, Richard A

    2008-11-01

    Hop (Humulus lupulus L. Cannabaceae) is an economically important crop for the brewing industry, where it is used to impart flavor and aroma to beer, and has also drawn attention in recent years due to its potential pharmaceutical applications. Essential oils (mono- and sesquiterpenes), bitter acids (prenylated polyketides), and prenylflavonoids are the primary phytochemical components that account for these traits, and all accumulate at high concentrations in glandular trichomes of hop cones. To understand the molecular basis for terpene accumulation in hop trichomes, a trichome cDNA library was constructed and 9,816 cleansed expressed sequence tag (EST) sequences were obtained from random sequencing of 16,152 cDNA clones. The ESTs were assembled into 3,619 unigenes (1,101 contigs and 2,518 singletons). Putative functions were assigned to the unigenes based on their homology to annotated sequences in the GenBank database. Two mono- and two sesquiterpene synthases identified from the EST collection were expressed in Escherichia coli. Hop MONOTERPENE SYNTHASE2 formed the linear monterpene myrcene from geranyl pyrophosphate, whereas hop SESQUITERPENE SYNTHASE1 (HlSTS1) formed both caryophyllene and humulene from farnesyl pyrophosphate. Together, these enzymes account for the production of the major terpene constituents of the hop trichomes. HlSTS2 formed the minor sesquiterpene constituent germacrene A, which was converted to beta-elemene on chromatography at elevated temperature. We discuss potential functions for other genes expressed at high levels in developing hop trichomes.

  14. Activation of metabotropic GABA receptors increases the energy barrier for vesicle fusion.

    PubMed

    Rost, Benjamin R; Nicholson, Patrick; Ahnert-Hilger, Gudrun; Rummel, Andreas; Rosenmund, Christian; Breustedt, Joerg; Schmitz, Dietmar

    2011-09-15

    Neurotransmitter release from presynaptic terminals is under the tight control of various metabotropic receptors. We report here that in addition to the regulation of Ca(2+) channel activity, metabotropic GABA(B) receptors (GABA(B)Rs) at murine hippocampal glutamatergic synapses utilize an inhibitory pathway that directly targets the synaptic vesicle release machinery. Acute application of the GABA(B)R agonist baclofen rapidly and reversibly inhibits vesicle fusion, which occurs independently of the SNAP-25 C-terminus. Using applications of hypertonic sucrose solutions, we find that the size of the readily releasable pool remains unchanged by GABA(B)R activation, but the sensitivity of primed vesicles to hypertonic stimuli appears lowered as the response amplitudes at intermediate sucrose concentrations are smaller and release kinetics are slowed. These data show that presynaptic GABA(B)Rs can inhibit neurotransmitter release directly by increasing the energy barrier for vesicle fusion.

  15. Detection of hydroxyl radicals during regeneration of granular activated carbon in dielectric barrier discharge plasma system

    NASA Astrophysics Data System (ADS)

    Tang, Shoufeng; Lu, Na; Shang, Kefeng; Li, Jie; Wu, Yan

    2013-03-01

    To understand the reactions taking place in the dielectric barrier discharge (DBD) plasma system of activated carbon regeneration, the determination of active species is necessary. A method based on High Performance Liquid Chromatography with radical trapping by salicylic acid, has been developed to measure hydroxyl radical (•OH) in the DBD plasma reactor. The effects of applied voltage, treatment time, and gas flow rate and atmosphere were investigated. Experimental results indicated that increasing voltage, treatment time and air flow rate could enhance the formation of •OH. Oxygen atmosphere and a suitable GAC water content were contributed to •OH generation. The results give an insight into plasma chemical processes, and can be helpful to optimize the design and application for the plasma system.

  16. The impact of microglial activation on blood-brain barrier in brain diseases

    PubMed Central

    da Fonseca, Anna Carolina Carvalho; Matias, Diana; Garcia, Celina; Amaral, Rackele; Geraldo, Luiz Henrique; Freitas, Catarina; Lima, Flavia Regina Souza

    2014-01-01

    The blood-brain barrier (BBB), constituted by an extensive network of endothelial cells (ECs) together with neurons and glial cells, including microglia, forms the neurovascular unit (NVU). The crosstalk between these cells guarantees a proper environment for brain function. In this context, changes in the endothelium-microglia interactions are associated with a variety of inflammation-related diseases in brain, where BBB permeability is compromised. Increasing evidences indicate that activated microglia modulate expression of tight junctions, which are essential for BBB integrity and function. On the other hand, the endothelium can regulate the state of microglial activation. Here, we review recent advances that provide insights into interactions between the microglia and the vascular system in brain diseases such as infectious/inflammatory diseases, epilepsy, ischemic stroke and neurodegenerative disorders. PMID:25404894

  17. Auto-acetylation on K289 is not essential for HopZ1a-mediated plant defense suppression

    PubMed Central

    Rufián, José S.; Lucía, Ainhoa; Macho, Alberto P.; Orozco-Navarrete, Begoña; Arroyo-Mateos, Manuel; Bejarano, Eduardo R.; Beuzón, Carmen R.; Ruiz-Albert, Javier

    2015-01-01

    The Pseudomonas syringae type III-secreted effector HopZ1a is a member of the HopZ/YopJ superfamily of effectors that triggers immunity in Arabidopsis. We have previously shown that HopZ1a suppresses both local [effector-triggered immunity (ETI)] and systemic immunity [systemic acquired resistance (SAR)] triggered by the heterologous effector AvrRpt2. HopZ1a has been shown to possess acetyltransferase activity, and this activity is essential to trigger immunity in Arabidopsis. HopZ1a acetyltransferase activity has been reported to require the auto-acetylation of the effector on a specific lysine (K289) residue. In this paper we analyze the relevance of autoacetylation of lysine residue 289 in HopZ1a ability to suppress plant defenses, and on the light of the results obtained, we also revise its relevance for HopZ1a avirulence activity. Our results indicate that, while the HopZ1aK289R mutant is impaired to some degree in its virulence and avirulence activities, is by no means phenotypically equivalent to the catalytically inactive HopZ1aC216A, since it is still able to trigger a defense response that induces detectable macroscopic HR and effectively protects Arabidopsis from infection, reducing growth of P. syringae within the plant. We also present evidence that the HopZ1aK289R mutant still displays virulence activities, partially suppressing both ETI and SAR. PMID:26217317

  18. Auto-acetylation on K289 is not essential for HopZ1a-mediated plant defense suppression.

    PubMed

    Rufián, José S; Lucía, Ainhoa; Macho, Alberto P; Orozco-Navarrete, Begoña; Arroyo-Mateos, Manuel; Bejarano, Eduardo R; Beuzón, Carmen R; Ruiz-Albert, Javier

    2015-01-01

    The Pseudomonas syringae type III-secreted effector HopZ1a is a member of the HopZ/YopJ superfamily of effectors that triggers immunity in Arabidopsis. We have previously shown that HopZ1a suppresses both local [effector-triggered immunity (ETI)] and systemic immunity [systemic acquired resistance (SAR)] triggered by the heterologous effector AvrRpt2. HopZ1a has been shown to possess acetyltransferase activity, and this activity is essential to trigger immunity in Arabidopsis. HopZ1a acetyltransferase activity has been reported to require the auto-acetylation of the effector on a specific lysine (K289) residue. In this paper we analyze the relevance of autoacetylation of lysine residue 289 in HopZ1a ability to suppress plant defenses, and on the light of the results obtained, we also revise its relevance for HopZ1a avirulence activity. Our results indicate that, while the HopZ1a(K289R) mutant is impaired to some degree in its virulence and avirulence activities, is by no means phenotypically equivalent to the catalytically inactive HopZ1a(C216A), since it is still able to trigger a defense response that induces detectable macroscopic HR and effectively protects Arabidopsis from infection, reducing growth of P. syringae within the plant. We also present evidence that the HopZ1a(K289R) mutant still displays virulence activities, partially suppressing both ETI and SAR.

  19. Long-range electron transfer in biomolecules. Tunneling or hopping?

    PubMed

    Voityuk, Alexander A

    2011-10-27

    Two competing mechanisms are relevant for long-range electron transfer (ET) in biomolecules: direct electron tunneling between donor (D) and acceptor (A), D → A, and multistep hopping D → X → A, where an electron or an electron hole is transiently localized on intermediate sites X. Which of these mechanisms dominates the ET reaction is determined by the arrangement and electronic properties of the redox centers. For thermal ET, it is shown that single-step tunneling is overcome by hopping when the energy gap E between D and X is smaller than the crossover barrier E(C), E(C) = (ΔG/2) + (3/4)k(B)TβR(DA), where ΔG is the driving force, β the decay parameter, and R(DA) the donor-acceptor distance. In proteins at T = 300 K, hopping will dominate when E < E(C) = (ΔG/2) + (R(DA)/50) (E and ΔG are in eV, R(DA) in Å); single-step tunneling will be operative when E > E(C). Thus, one can explore the ET mechanism using three quantities E, ΔG, and R(DA). When ΔG = 0 and E = 0.5 eV (the difference in redox potentials of D and X is 0.5 V), two-step hopping D → X → A will be favored at R(DA) >25 Å. In protein ET chains, the distance between redox cofactors is often smaller than 20 Å, but the gap E between the cofactors and surrounding amino acid residues is larger than 0.5 eV. Therefore, ET in the systems should occur by single-step tunneling D → A. In the activationless regime (ΔG ≈ -λ, λ is the reorganization energy) often observed for photoinduced ET, the crossing point energy is determined by E(C) = (2λkTβR(DA))(1/2) - λ. The suggested expressions for the threshold barrier may be useful to predict the ET mechanism in natural and artificial redox systems.

  20. Effect of atmospheric pressure dielectric barrier discharge plasma on the biological activity of naringin.

    PubMed

    Kim, Hyun-Joo; Yong, Hae In; Park, Sanghoo; Kim, Kijung; Kim, Tae Hoon; Choe, Wonho; Jo, Cheorun

    2014-10-01

    The biological activity of naringin treated with atmospheric pressure plasma was evaluated to investigate whether exposure to plasma can be used as a method to improve the biological activity of natural materials. Naringin was dissolved in methanol (at 500 ppm) and transferred to a container. A dielectric barrier discharge (DBD) (250 W, 15 kHz, ambient air) was then generated. Treatment with the plasma for 20 min increased the radical-scavenging activity, FRAP value, and the total phenolic compound content of naringin from 1.45% to 38.20%, from 27.78 to 207.78 μM/g, and from 172.50 to 225.83 ppm, respectively. Moreover, the tyrosinase-inhibition effect of naringin increased from 6.12% to 83.30% upon plasma treatment. Naringin treated with plasma exhibited antimicrobial activity against foodborne pathogens, especially Salmonella Typhimurium; an activity that was absent before plasma treatment. Structural modifications induced in the naringin molecule by plasma might be responsible for improving the biological activity of naringin.

  1. Enjoyment, Barriers, and Beliefs about Physical Activity among Adolescents With and Without Autism Spectrum Disorder

    PubMed Central

    Stanish, Heidi I.; Curtin, Carol; Must, Aviva; Phillips, Sarah; Maslin, Melissa; Bandini, Linda G.

    2016-01-01

    We compared physical activity enjoyment, perceived barriers, beliefs, and self-efficacy between adolescents with ASD and typically developing (TD) adolescents. A questionnaire was verbally administered to 35 adolescents with ASD and 60 TD adolescents. Compared to TD adolescents, fewer adolescents with ASD enjoyed team sports (65% vs. 95%, p<0.001) and physical education (84% vs. 98%, p=0.02). A greater proportion of adolescents with ASD perceived that physical activities were too hard to learn (16% vs. 0%, p<0.01), and fewer adolescents with ASD believed that physical activity was a way to make friends (68% vs. 97%, p<0.001). Fewer adolescents with ASD preferred to do physical activity in their free time (25% vs. 58%, p<0.01). Most adolescents with ASD felt that physical activity is fun (84%), but the proportion was lower than TD adolescents (98%, p=0.03). Some perceptions about physical activity were similar between the two groups, but differences identified may inform program development. PMID:26485735

  2. Steerable Hopping Six-Legged Robot

    NASA Technical Reports Server (NTRS)

    Younse, Paulo; Aghazarian, Hrand

    2010-01-01

    The figure depicts selected aspects of a six-legged robot that moves by hopping and that can be steered in the sense that it can be launched into a hop in a controllable direction. This is a prototype of hopping robots being developed for use in scientific exploration of rough terrain on remote planets that have surface gravitation less than that of Earth. Hopping robots could also be used on Earth, albeit at diminished hopping distances associated with the greater Earth gravitation. The upper end of each leg is connected through two universal joints to an upper and a lower hexagonal frame, such that the tilt of the leg depends on the relative position of the two frames. Two non-back-driveable worm-gear motor drives are used to control the relative position of the two frames along two axes 120 apart, thereby controlling the common tilt of all six legs and thereby, further, controlling the direction of hopping. Each leg includes an upper and a lower aluminum frame segment with a joint between them. A fiberglass spring, connected via hinges to both segments, is used to store hopping energy prior to launch into a hop and to cushion the landing at the end of the hop. A cable for loading the spring is run into each leg through the center of the universal joints and then down along the center lines of the segments to the lower end of the leg. A central spool actuated by a motor with a harmonic drive and an electromagnetic clutch winds in all six cables to compress all six springs (thereby also flexing all six legs) simultaneously. To ensure that all the legs push off and land in the same direction, timing- belt pulley drives are attached to the leg segments, restricting the flexing and extension of all six legs to a common linear motion. In preparation for a hop, the spool can be driven to load the spring legs by an amount corresponding to a desired hop distance within range. The amount of compression can be computed from the reading of a shaft-angle encoder that

  3. Butyrate enhances the intestinal barrier by facilitating tight junction assembly via activation of AMP-activated protein kinase in Caco-2 cell monolayers.

    PubMed

    Peng, Luying; Li, Zhong-Rong; Green, Robert S; Holzman, Ian R; Lin, Jing

    2009-09-01

    Butyrate, one of the SCFA, promotes the development of the intestinal barrier. However, the molecular mechanisms underlying the butyrate regulation of the intestinal barrier are unknown. To test the hypothesis that the effect of butyrate on the intestinal barrier is mediated by the regulation of the assembly of tight junctions involving the activation of the AMP-activated protein kinase (AMPK), we determined the effect of butyrate on the intestinal barrier by measuring the transepithelial electrical resistance (TER) and inulin permeability in a Caco-2 cell monolayer model. We further used a calcium switch assay to study the assembly of epithelial tight junctions and determined the effect of butyrate on the assembly of epithelial tight junctions and AMPK activity. We demonstrated that the butyrate treatment increased AMPK activity and accelerated the assembly of tight junctions as shown by the reorganization of tight junction proteins, as well as the development of TER. AMPK activity was also upregulated by butyrate during calcium switch-induced tight junction assembly. Compound C, a specific AMPK inhibitor, inhibited the butyrate-induced activation of AMPK. The facilitating effect of butyrate on the increases in TER in standard culture media, as well as after calcium switch, was abolished by compound C. We conclude that butyrate enhances the intestinal barrier by regulating the assembly of tight junctions. This dynamic process is mediated by the activation of AMPK. These results suggest an intriguing link between SCFA and the intracellular energy sensor for the development of the intestinal barrier.

  4. Physical activity interventions differentially affect exercise task and barrier self-efficacy: A meta-analysis

    PubMed Central

    Higgins, Torrance J.; Middleton, Kathryn R.; Winner, Larry; Janelle, Christopher M.; Middleton, Kathryn R.

    2014-01-01

    Objective Researchers have yet to establish how interventions to increase physical activity influence specific self-efficacy beliefs. The current study sought to quantify the effect of interventions to increase physical activity among healthy adults on exercise task (EXSE) and barrier self-efficacy (BSE) via meta-analysis. Intervention characteristics associated with self-efficacy and physical activity changes were also identified. Methods A systematic database search and manual searches through reference lists of related publications were conducted for articles on randomized, controlled physical activity interventions. Published intervention studies reporting changes in physical activity behavior and either EXSE or BSE in healthy adults were eligible for inclusion. Results Of the 1,080 studies identified, 20 were included in the meta-analyses. Interventions had a significant effect of g = 0.208, 95% confidence interval (CI) [0.027, 0.388], p < .05, on EXSE; g = 0.128, 95% CI [0.05, 0.20], p < .05 on BSE; and g = 0.335 95% CI [0.196, 0.475], p < .001, on physical activity. Moderator analyses indicated shorter interventions that did not include structured exercise sessions effectively increased EXSE and physical activity, whereas long interventions improved BSE. Interventions that did not provide support increased BSE and physical activity levels. Further, interventions that did not require the use of daily exercise logs improved EXSE and physical activity behavior. Conclusion Interventions designed to increase physical activity differentially influenced EXSE and BSE. EXSE appeared to play a more significant role during exercise adoption, whereas BSE was involved in the maintenance of exercise behavior. Recommendations are offered for the design of future interventions. PMID:23957904

  5. Single-leg hop testing following fatiguing exercise: reliability and biomechanical analysis.

    PubMed

    Augustsson, J; Thomeé, R; Lindén, C; Folkesson, M; Tranberg, R; Karlsson, J

    2006-04-01

    knee flexion and generated powers for the knee and ankle joints during take-off, and less hip joint moments during landing under fatigued conditions. The large negative power values observed at the knee joint during the landing phase of the single-leg hop, during which the quadriceps muscle activates eccentrically, indicate that not only hop distance but also the ability to perform successful landings should be investigated when assessing dynamic knee function.

  6. Barriers and enablers of physical activity engagement for patients with COPD in primary care

    PubMed Central

    Kosteli, Maria-Christina; Heneghan, Nicola R; Roskell, Carolyn; Williams, Sarah E; Adab, Peymane; Dickens, Andrew P; Enocson, Alexandra; Fitzmaurice, David A; Jolly, Kate; Jordan, Rachel; Greenfield, Sheila; Cumming, Jennifer

    2017-01-01

    Background Given that physical activity (PA) has a positive impact on COPD symptoms and prognosis, this study examined the factors that both encourage and limit participation in PA for individuals with COPD in a primary care setting from the perspective of social cognitive theory. Methods A purposive sample of 26 individuals with a range of COPD severity (age range: 50–89 years; males =15) were recruited from primary care to participate in one of four focus groups. Thematic analysis was undertaken to identify key concepts related to their self-efficacy beliefs. Results Several barriers and enablers closely related to self-efficacy beliefs and symptom severity were identified. The main barriers were health related (fatigue, mobility problems, breathing issues caused by the weather), psychological (embarrassment, fear, frustration/disappointment), attitudinal (feeling in control of their condition, PA perception, older age perception), and motivational. The main enabling factors were related to motivation (autonomous or controlled), attitudes, self-regulation, and performance accomplishments. Clinical implications When designing interventions for individuals with COPD, it is important to understand the patient-specific social cognitive influences on PA participation. This information can then inform individually tailored management planning.

  7. Perceived Barriers to and Facilitators of Physical Activity in Recipients of Solid Organ Transplantation, a Qualitative Study

    PubMed Central

    van de Zande, Saskia C.; Dekker, Rienk; Verschuuren, Erik A. M.; Dijkstra, Pieter U.; van der Schans, Cees P.

    2016-01-01

    Background Sufficient physical activity is important for solid organ transplant recipients (heart, lung, liver, kidney). However, recipients do not meet the recommended amount or required type of physical activity. The perceived barriers to and facilitators of physical activity in this population are largely unknown. Methods Semi-structured in depth interviews were conducted with solid organ transplant recipients in order to explore experienced barriers and facilitators. Qualitative methodology with thematic line-by-line analysis was used for analysis, and derived themes were classified into personal and environmental factors. Results The most important indicated barriers were physical limitations, insufficient energy level, fear, and comorbidities. The most frequently mentioned facilitators included motivation, coping, consequences of (in)activity, routine/habit, goals/goal priority, and responsibility for the transplanted organ. Neutral factors acting as a barrier or facilitator were self-efficacy and expertise of personnel. A comparison of barriers and facilitators between transplant recipient groups yielded no overt differences. Conclusion Several personal and environmental factors were indicated that should be considered in intervention development to increase physical activity behavior in solid organ transplant recipients. PMID:27622291

  8. Barriers to and Facilitators of Physical Activity Program Use Among Older Adults

    PubMed Central

    Bethancourt, Hilary J.; Rosenberg, Dori E.; Beatty, Tara; Arterburn, David E.

    2014-01-01

    Objective Regular physical activity (PA) is important for maintaining long-term physical, cognitive, and emotional health. However, few older adults engage in routine PA, and even fewer take advantage of programs designed to enhance PA participation. Though most managed Medicare members have free access to the Silver Sneakers and EnhanceFitness PA programs, the vast majority of eligible seniors do not utilize these programs. The goal of this qualitative study was to better understand the barriers to and facilitators of PA and participation in PA programs among older adults. Design This was a qualitative study using focus group interviews. Setting Focus groups took place at three Group Health clinics in King County, Washington. Participants Fifty-two randomly selected Group Health Medicare members between the ages of 66 to 78 participated. Methods We conducted four focus groups with 13 participants each. Focus group discussions were audio-recorded, transcribed, and analyzed using an inductive thematic approach and a social-ecological framework. Results Men and women were nearly equally represented among the participants, and the sample was largely white (77%), well-educated (69% college graduates), and relatively physically active. Prominent barriers to PA and PA program participation were physical limitations due to health conditions or aging, lack of professional guidance, and inadequate distribution of information on available and appropriate PA options and programs. Facilitators included the motivation to maintain physical and mental health and access to affordable, convenient, and stimulating PA options. Conclusion Older adult populations may benefit from greater support and information from their providers and health care systems on how to safely and successfully improve or maintain PA levels through later adulthood. Efforts among health care systems to boost PA among older adults may need to consider patient-centered adjustments to current PA programs, as

  9. Novel Nrf2 activators from microbial transformation products inhibit blood–retinal barrier permeability in rabbits

    PubMed Central

    Nakagami, Yasuhiro; Masuda, Kayoko; Hatano, Emiko; Inoue, Tatsuya; Matsuyama, Takuya; Iizuka, Mayumi; Ono, Yasunori; Ohnuki, Takashi; Murakami, Yoko; Iwasaki, Masaru; Yoshida, Kazuhiro; Kasuya, Yuji; Komoriya, Satoshi

    2015-01-01

    Background and Purpose Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that binds to antioxidant response elements located in the promoter region of genes encoding many antioxidant enzymes and phase II detoxifying enzymes. Activation of the Nrf2 pathway seems protective for many organs, and although a well-known Nrf2 activator, bardoxolone methyl, was evaluated clinically for treating chronic kidney disease, it was found to induce adverse events. Many bardoxolone methyl derivatives, mostly derived by chemical modifications, have already been studied. However, we adopted a biotransformation technique to obtain a novel Nrf2 activator. Experimental Approach The potent novel Nrf2 activator, RS9, was obtained from microbial transformation products. Its Nrf2 activity was evaluated by determining NADPH:quinone oxidoreductase-1 induction activity in Hepa1c1c7 cells. We also investigated the effects of RS9 on oxygen-induced retinopathy in rats and glycated albumin-induced blood–retinal barrier permeability in rabbits because many ocular diseases are associated with oxidative stress and inflammation. Key Results Bardoxolone methyl doubled the specific activity of Nrf2 in Hepa1c1c7 cells at a much higher concentration than RS9. Moreover, the induction of Nrf2-targeted genes was observed at a one-tenth lower concentration of RS9. Interestingly, the cytotoxicity of RS9 was substantially reduced compared with bardoxolone methyl. Oral and intravitreal administration of RS9 ameliorated the pathological scores and leakage in the models of retinopathy in rats and ocular inflammation in rabbits respectively. Conclusion and Implications Nrf2 activators are applicable for treating ocular diseases and novel Nrf2 activators have potential as a unique method for prevention and treatment of retinovascular disease. PMID:25363737

  10. Characterization of the Migration of Hop Volatiles into Different Crown Cork Liner Polymers and Can Coatings.

    PubMed

    Wietstock, Philip C; Glattfelder, Richard; Garbe, Leif-Alexander; Methner, Frank-Jürgen

    2016-04-06

    Absorption of hop volatiles by crown cork liner polymers and can coatings was investigated in beer during storage. All hop volatiles measured were prone to migrate into the closures, and the absorption kinetics was demonstrated to fit Fick's second law of diffusion well for a plane sheet. The extent and rate of diffusion were significantly dissimilar and were greatly dependent upon the nature of the volatile. Diffusion coefficients ranged from 1.32 × 10(-5) cm(2)/day (limonene) to 0.26 × 10(-5) cm(2)/day (α-humulene). The maximum amounts absorbed into the material at equilibrium were in the following order: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With the application of low-density polyethylene (LDPE) liners with oxygen-scavenging functionality, oxygen-barrier liners made up from high-density polyethylene (HDPE) or liner polymers from a different manufacturer had no significant effect on the composition of hop volatiles in beers after prolonged storage of 55 days; however, significantly higher amounts of myrcene and limonene were found in the oxygen-barrier-type crown cork, while all other closures behaved similarly. Can coatings were demonstrated to absorb hop volatiles in a similar pattern as crown corks but to a lesser extent. Consequently, significantly higher percentages of myrcene were found in the beers.

  11. Influence of photoexcitation on hopping conduction in neutron-transmutation-doped GaAs

    SciTech Connect

    Satoh, M.; Kawahara, H.; Kuriyama, K.; Kawakubo, T.; Yoneda, K.; Kimura, I.

    1988-02-15

    The nature of the tunneling-assisted hopping conduction in neutron-transmutation-doped GaAs has been studied under photoexcitation with a photon energy of 1.32 eV. It is found that the dopants activated by annealing around 400 /sup 0/C provide the electrons to the defect levels originating the hopping conduction even when under photoexcitation. The hopping conduction under photoexcitation is affected by quenching in photoconductance below 120 K concerned with the main electron trap (EL2) and/or the As antisite defect (As/sub Ga/) induced by the neutron irradiation. The photoconductance of the samples with a lower radiation damage, As/sub Ga/less than or equal to1 x 10/sup 18/ cm/sup -3/, consists of the coexistence of the hopping and band conductions.

  12. Novel Functions of the Anticoagulant Activated Protein C in Maintaining Skin Barrier Integrity to Impact on Skin Disease.

    PubMed

    Xue, Meilang; Jackson, Christopher John

    2015-01-01

    The epidermis is the outermost skin layer and provides the first line of defence against the external environment. Keratinocytes are the most predominant cells in the epidermis and play a critical role in maintaining epidermal barrier function. When the barrier is disrupted any of a number of diseases, such as chronic wounds, psoriasis, pemphigus, atopic dermatitis or toxic epidermal necrolysis, can take hold. Activated protein C (APC) or its precursor, protein C, is abundantly expressed by skin epidermal keratinocytes and stimulates their proliferation and migration, and inhibits apoptosis and inflammation, leading to a healing phenotype. Importantly, APC also increases the barrier function of keratinocytes by promoting expression and cell-cell contact redistribution of tight junction proteins. These cytoprotective properties of APC on epidermal keratinocytes place it as an exciting new therapy for skin disorders associated with the disruption of barrier function and inflammation.

  13. 75 FR 9431 - Small and Medium-Sized Enterprises: U.S. and EU Export Activities, and Barriers and Opportunities...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Small and Medium-Sized Enterprises: U.S. and EU Export Activities, and Barriers and Opportunities... investigations, investigation No. 332-509, Small and Medium-Sized Enterprises: U.S. and EU Export Activities,...

  14. [Activating physiotherapy for chronic pain in elderly patients. Recommendations, barriers and resources].

    PubMed

    Kuss, K; Laekeman, M

    2015-08-01

    Elderly patients with chronic pain are particularly at risk of functional limitations up to the loss of autonomy and social life. To facilitate autonomy, mobility and quality of life, physiotherapy plays an essential role in pain management. Nevertheless, programs that are specifically geared towards the needs of older patients are still uncommon. This article offers recommendations for structuring physiotherapy programs based on international guideline recommendations. First examples of pain management concepts for older adults demonstrate the positive results of activating therapy. Additionally, this article provides insights into barriers and resources of affected patients and all actors involved. However, physiotherapeutic treatment for aged chronic pain patients in Germany still shows considerable shortcomings but also offers an exciting challenge for the future.

  15. MALT1 Protease Activation Triggers Acute Disruption of Endothelial Barrier Integrity via CYLD Cleavage.

    PubMed

    Klei, Linda R; Hu, Dong; Panek, Robert; Alfano, Danielle N; Bridwell, Rachel E; Bailey, Kelly M; Oravecz-Wilson, Katherine I; Concel, Vincent J; Hess, Emily M; Van Beek, Matthew; Delekta, Phillip C; Gu, Shufang; Watkins, Simon C; Ting, Adrian T; Gough, Peter J; Foley, Kevin P; Bertin, John; McAllister-Lucas, Linda M; Lucas, Peter C

    2016-09-27

    Microvascular endothelial cells maintain a tight barrier to prevent passage of plasma and circulating immune cells into the extravascular tissue compartment, yet endothelial cells respond rapidly to vasoactive substances, including thrombin, allowing transient paracellular permeability. This response is a cornerstone of acute inflammation, but the mechanisms responsible are still incompletely understood. Here, we demonstrate that thrombin triggers MALT1 to proteolytically cleave cylindromatosis (CYLD). Fragmentation of CYLD results in microtubule disruption and a cascade of events leading to endothelial cell retraction and an acute permeability response. This finding reveals an unexpected role for the MALT1 protease, which previously has been viewed mostly as a driver of pro-inflammatory NF-κB signaling in lymphocytes. Thus, MALT1 not only promotes immune cell activation but also acutely regulates endothelial cell biology, actions that together facilitate tissue inflammation. Pharmacologic inhibition of MALT1 may therefore have synergistic impact by targeting multiple disparate steps in the overall inflammatory response.

  16. Localized MHD Activity near Transport Barriers in JT-60U and TFTR

    SciTech Connect

    . Kamada, Y.; Fujita, T.; Gorelenkov, N.; Isayama, A.; Manickam, J.; et al.

    1998-11-01

    Localized MHD activity observed in JT-60U and TFTR near transport barriers with their associated large pressure gradients is investigated. Stability analysis of equilibria modeling the experiments supports an identification of this MHD as being due to an ideal MHD n = 1 instability. The appearance of the instability depends on the local pressure gradient, local shear in the q profile, and the proximity of rational surfaces where q is approximately equal to m/n and m and n are the poloidal and toroidal mode numbers, respectively. The mode width is shown to depend on the local value of q, and is larger when q is smaller. In addition, the role of the edge current density in coupling the internal mode to the plasma edge and of the energetic particles which can drive fishbone-like modes is investigated.

  17. Degradation of hop bitter acids by fungi.

    PubMed

    Huszcza, Ewa; Bartmańska, Agnieszka; Anioł, Mirosław; Maczka, Wanda; Zołnierczyk, Anna; Wawrzeńczyk, Czesław

    2008-01-01

    Nine fungal strains related to: Trametes versicolor, Nigrospora oryzae, Inonotus radiatus, Crumenulopsis sororia, Coryneum betulinum, Cryptosporiopsis radicicola, Fusarium equiseti, Rhodotorula glutinis and Candida parapsilosis were tested for their ability to degrade humulones and lupulones. The best results were obtained for T. versicolor culture, in which humulones and lupulones were fully degraded after 4days of incubation in the dark or after 36h in the light. The experiments were performed on a commercial hop extract and on sterilized spent hops.

  18. Effects of ionizing radiation on the blood brain barrier permeability to pharmacologically active substances

    SciTech Connect

    Trnovec, T.; Kallay, Z.; Bezek, S. )

    1990-12-01

    Ionizing radiation can impair the integrity of the blood brain barrier (BBB). Data on early and late damage after brain irradiation are usually reported separately, yet a gradual transition between these two types has become evident. Signs appearing within 3 weeks after irradiation are considered to be early manifestations. The mechanism of radiation-effected integrity impairment of the BBB is discussed in relation to changes in morphological structures forming the BBB, the endothelium of intracerebral vessels, and in the surrounding astrocytes. Alterations in the function of the BBB are manifested in the endothelium by changes in the ultrastructural location of the activity of phosphatases and by the activation of pinocytotic vesicular transport, and in astrocyte cytoplasm by glycogen deposition. The changes in ultrastructure were critically surveyed with regard to increasing doses of radiation to the brain in the range of 5 Gy to 960 Gy. The qualitative as well as the semiquantitative and quantitative observations on the passage of substances across the damaged BBB were treated separately. Qualitative changes are based mainly on findings of extravasation of vital stains and of labelled proteins. The quantitative studies established differences in radiation-induced changes in the permeability of the BBB depending on the structure and physico-chemical properties of the barrier penetrating tracers. Indirect evaluation of radiation-induced BBB changes is based on studies of pharmacological effects of substances acting on the CNS. In conclusion, radiation impairs significantly the integrity of the BBB following single irradiation of the brain with a dose exceeding 10-15 Gy. The response of the BBB to ionizing radiation is dependent both on the dose to which the brain is exposed and on specific properties of the tracer. 68 references.

  19. Temperature-dependent hydration at micellar surface: activation energy barrier crossing model revisited.

    PubMed

    Mitra, Rajib Kumar; Sinha, Sudarson Sekhar; Pal, Samir Kumar

    2007-07-05

    In recent years, the validity of the activation energy barrier crossing model at the micellar surface brings notable controversy (Sen, P.; Mukherjee, S.; Halder, A.; Bhattacharyya, K. Chem. Phys. Lett. 2004, 385, 357-361. Kumbhakar, M.; Goel, T.; Mukherjee, T.; Pal, H. J. Phys. Chem. B 2004, 108, 19246-19254.) in the literature. In order to check the validity of the model by time-resolved solvation of a probe fluorophore, a wider range of temperature must be considered. At the same time, spatial heterogeneity (solubilization) of the probe and structural perturbation of the host micelle should carefully be avoided, which was not strictly maintained in the earlier studies. We report here the solvation dynamics of 4-(dicyanomethylene)-2-methyl-6(p-dimethylamino-styryl) 4H-pyran (DCM) in the SDS micelle at 298, 323, and 348 K. The probe DCM is completely insoluble in bulk water in this wide range of temperature. The size of the micelle at different temperatures using the dynamic light scattering (DLS) technique is found to have insignificant change. The hydration number of the micelle, determined by sound velocity measurements, decreases with increasing temperature. Time-resolved fluorescence anisotropy reveals the retention of the probe in the micellar interface within the temperature range. The average solvation time decreases with increasing temperature. The result of the solvation study has been analyzed in the light of energetics of bound to free water conversion at a constant size and decreasing hydration number at the micellar surface. The solvation process at the micellar surface has been found to be the activation energy barrier crossing type, in which interfacially bound type water molecules get converted into free type molecules. We have calculated Ea to be 3.5 kcal mol-1, which is in good agreement with that obtained by molecular dynamics simulation studies.

  20. International Collaborations on Engineered Barrier Systems: Brief Overview of SKB-EBS Activities.

    SciTech Connect

    Jove-Colon, Carlos F.

    2015-10-01

    Research collaborations with international partners on the behavior and performance of engineered barrier systems (EBS) are an important aspect of the DOE-NE Used Fuel Disposition Campaign strategy in the evaluation of disposal design concepts. These international partnerships are a cost-effective way of engaging in key R&D activities with common goals resulting in effective scientific knowledge exchanges thus enhancing existing and future research programs in the USA. This report provides a brief description of the activities covered by the Swedish Nuclear Fuel and Waste Management Company (SKB) EBS Task Force (TF) (referred hereafter as SKB EBS TF) and potential future directions for engagement of the DOE-NE UFDC program in relevant R&D activities. Emphasis is given to SKB EBS TF activities that are still ongoing and aligned to the UFDC R&D program. This include utilization of data collected in the bentonite rock interaction experiment (BRIE) and data sets from benchmark experiments produced by the chemistry or “C” part of the SKB EBS TF. Potential applications of information generated by this program include comparisons/tests between model and data (e.g., reactive diffusion), development and implementation of coupled-process models (e.g., HM), and code/model benchmarking.

  1. Effect of fatigue on single-leg hop landing biomechanics.

    PubMed

    Orishimo, Karl F; Kremenic, Ian J

    2006-11-01

    The objective of this study was to measure adaptations in landing strategy during single-leg hops following thigh muscle fatigue. Kinetic, kinematic, and electromyographic data were recorded as thirteen healthy male subjects performed a single-leg hop in both the unfatigued and fatigued states. To sufficiently fatigue the thigh muscles, subjects performed at least two sets of 50 step-ups. Fatigue was assessed by measuring horizontal hopping ability following the protocol. Joint motion and loading, as well as muscle activation patterns, were compared between fatigued and unfatigued conditions. Fatigue significantly increased knee motion (p = 0.012) and shifted the ankle into a more dorsiflexed position (p = 0.029). Hip flexion was also reduced following fatigue (p = 0.042). Peak extension moment tended to decrease at the knee and increase at the ankle and hip (p = 0.014). Ankle plantar flexion moment at the time of peak total support moment increased from 0.8 (N x m)/kg (SD, 0.6 [N x m]/kg) to 1.5 (N x m)/kg (SD, 0.8 [N x m]/kg) (p = 0.006). Decreased knee moment and increased knee flexion during landings following fatigue indicated that the control of knee motion was compromised despite increased activation of the vastus medialis, vastus lateralis, and rectus femoris (p = 0.014, p = 0.014, and p = 0.017, respectively). Performance at the ankle increased to compensate for weakness in the knee musculature and to maintain lower extremity stability during landing. Investigating the biomechanical adaptations that occur in healthy subjects as a result of muscle fatigue may give insight into the compensatory mechanisms and loading patterns occurring in patients with knee pathology. Changes in single-leg hop landing performance could be used to demonstrate functional improvement in patients due to training or physical therapy.

  2. Discovery of molluscicidal and cercaricidal activities of 3-substituted quinazolinone derivatives by a scaffold hopping approach using a pseudo-ring based on the intramolecular hydrogen bond formation.

    PubMed

    Guo, Wei; Zheng, Lv-Yin; Li, Yong-Dong; Wu, Ren-Miao; Chen, Qiang; Yang, Ding-Qiao; Fan, Xiao-Lin

    2016-06-10

    Discovery of novel topological agents against Oncomelania hupensis snails and cercariae remains a significant challenge in current Schistosomiasis control. A pseudo-ring formed from salicylanilide by an intramolecular hydrogen bond led to the discovery of 3-substituted quinazolinone derivatives which showed a potent molluscicidal and cercaricidal activities.

  3. Driving reactions: Surmounting activation barriers in solid state chemistry using hydroxide melts and RF plasmas

    NASA Astrophysics Data System (ADS)

    Friedman, Todd Lawrence

    1997-11-01

    This thesis explores several techniques for surmounting activation barriers in solid state chemistry. The two major issues addressed are the use of a solution-based molten hydroxide system to increase the rate of reactant diffusion over that in the solid state, and the use of an RF plasma to break bonds in gaseous reactants for subsequent reaction with a solid. Part I describes the use of molten alkali metal hydroxides as a low-temperature solvent system for both electrodeposition and precipitation of high valent copper oxides. Cyclic voltammetry was used to determine the effects of various reaction conditions on copper dissolved in the melts, including copper activity, temperature, and atmosphere composition. The results of this study indicate that copper oxide phases become less soluble at higher copper activities, temperatures, and pHsb2O values. Also, the Cu(II)/Cu(III) redox wave, important for the electrodeposition of cuprate phases with high copper formal oxidation states, is observed below 300sp°C in air and at 350sp°C in dry argon. NaCuOsb2 was electrodeposited under constant current conditions. Iodometric titrations and annealing studies indicate that NaCuOsb2 is oxygen deficient and tends to lose additional oxygen on heating. The hydroxide method was also successful in the deposition of thin films of superconducting EuBasb2Cusb4Osb8 on SrTiOsb3 substrates. The films were found to be superconducting with a Tsbc of 75 K in the absence of annealing. In Part II, the idea of circumventing activation energy barriers is applied to the problem of environmentally harmful perfluorocarbons (PFCs). Mass spectrometry was used to determine the PFC emissions from two semiconductor manufacturing processes: oxide etch and post-CVD chamber clean. Because of radical recombination to thermodynamically stable species, most of the PFCs used in these processes are emitted to the atmosphere. A prototype abatement device which uses an RF plasma to provide the activation energy

  4. Imbalance in expression of hop (Humulus lupulus) chalcone synthase H1 and its regulators during hop stunt viroid pathogenesis.

    PubMed

    Füssy, Zoltán; Patzak, Josef; Stehlík, Jan; Matoušek, Jaroslav

    2013-05-01

    Viroid-derived small RNAs generated during hop stunt viroid (HSVd) pathogenesis may induce the symptoms found in the hop cultivar "Admiral", including observed shifts in phenylpropanoid metabolites and changes in petiole coloration. Using quantitative RT-PCR, we examined hop lupulin gland-specific genes that have been shown to be involved in phenylpropanoid metabolism, for altered expression in response to infection with two HSVd isolates, HSVd-g and CPFVd. Most notably, the expression of a gene encoding a key enzyme for phenylpropanoid synthesis, naringenin-chalcone synthase H1 (chs_H1), decreased up to 40-fold in infected samples. In addition, a marked decrease in the expression of HlbHLH2 and an increase in the expression of HlMyb3 were observed. These two genes encode transcription factors that form a ternary complex with HlWDR1 for chs_H1 promoter activation. In a transient expression assay, a decrease in the ternary complex potential to activate the chs_H1 promoter was observed upon the decrease of HlbHLH2 expression. In addition, targeting of the chs_H1 transcript by vd-sRNAs may contribute to these expression changes. Our data show that HSVd infection causes a significant imbalance in the expression of phenylpropanoid metabolite-affecting genes via a complex mechanism, possibly involving regulatory disorders and direct targeting by vd-sRNA.

  5. Physical Activity and Reported Barriers to Activity Among Type 2 Diabetic Patients in the United Arab Emirates

    PubMed Central

    Al-Kaabi, Juma; Al-Maskari, Fatma; Afandi, Bachar; Parkar, Hasratali; Nagelkerke, Nicolaas

    2009-01-01

    OBJECTIVES: This study was designed to assess the physical activity practice among type 2 diabetic patients in the United Arab Emirates (UAE). METHODS: This is a cross-sectional study of type 2 diabetic patients who participated in the outpatient clinics in Al-Ain District, during 2006. The patients completed an interviewer-administered questionnaire, and measurements of blood pressure, body mass index, body fat, abdominal circumference, glycemic control (HbA1c), and fasting lipid profile. RESULTS: Of the 390 patients recruited, only 25% reported an increase in their physical activity levels following the diagnosis of diabetes, and only 3% reported physical activity levels that meet the recommended guidelines. More than half of the study subjects had uncontrolled hypertension (53%) and unacceptable lipid profiles; 71% had a high low-density lipoprotein (LDL), 73% had low high-density lipoprotein (HDL), and 59% had hypertriglyceridemia. Forty-four percent were obese and a further 34% were overweight. Abdominal obesity was also common (59%). Only 32% had an acceptable glycemic control. CONCLUSIONS: The physical activity practice of type 2 diabetic patients in the UAE is largely inadequate to meet the recommended level necessary to prevent or ameliorate diabetic complications. Interventions aiming at overcoming the barriers to physical activity are urgently needed. PMID:20043039

  6. Diel patterns in sea urchin activity and predation on sea urchins on the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Young, M. A. L.; Bellwood, D. R.

    2011-09-01

    Understanding diel patterns in sea urchin activity is important when assessing sea urchin populations and when interpreting their interactions with predators. Here we employ a combination of surveys and a non-invasive tethering technique to examine these patterns in an intact coral reef system on the Great Barrier Reef (GBR). We also assess local scale variation in relative diurnal predation pressure. Surveys revealed that sea urchins were active and exposed at night. Echinometra mathaei and Echinothrix calamaris were the most abundant species with significantly higher night densities (0.21 and 0.03 ind. m-2, respectively), than daytime densities (0.05 and 0.001, respectively). Bioassays revealed that exposed adult E. mathaei (the most abundant sea urchin species) were 30.8 times more likely to be eaten during the day than at night when controlling for sites. This observation concurs with widely held assumptions that nocturnal activity is a risk-related adaptive response to diurnal predation pressure. Despite relatively intact predator communities on the GBR, potential predation pressure on diurnally exposed E. mathaei assays was variable at a local scale and the biomass of potential fish predators at each site was a poor predictive measure of this variation. Patterns in predation appear to be more complex and variable than we may have assumed.

  7. Purification and characterization of metabolically active capillaries of the blood-brain barrier.

    PubMed Central

    Dallaire, L; Tremblay, L; Béliveau, R

    1991-01-01

    Microvessels were isolated from bovine and rat cerebral cortex by simple procedures involving mechanical homogenization, differential and density-gradient centrifugation, and chromatography on a column of glass beads. The preparations were composed of short capillaries with a diameter of 1-10 microns. Both purifications were monitored by assaying the activity of the marker enzyme gamma-glutamyl transpeptidase (gamma-GTase). The final bovine and rat preparations were enriched 20- and 14-fold over the homogenate respectively. gamma-GTase activity was measured in different fractions after bovine and rat membranes were solubilized with 0.5% and 0.3% Triton X-100 respectively. Measurement of 5'-nucleotidase and acetylcholinesterase activities indicated very low levels of contamination of the microvessel preparations by glial cells and neurons. The integrity of the capillary membranes was confirmed by the assay of a cytosolic marker enzyme, lactate dehydrogenase. Viability of the microvessels was demonstrated by the presence of detectable levels of adenylates and by tissue respiration induced by glucose and succinate. Comparison of the proteins of homogenized bovine and rat brain cortex with those of purified capillaries separated by SDS/PAGE revealed enrichment of at least three predominant proteins of 14, 16 and 18 kDa in the capillary preparations. It is concluded that these methods allow rapid isolation of small blood vessels of the blood-brain barrier which are suitable for metabolic and structural studies in vitro. Images Fig. 2. Fig. 4. PMID:1712199

  8. Confronting surface hopping molecular dynamics with Marcus theory for a molecular donor-acceptor system.

    PubMed

    Spencer, Jacob; Scalfi, Laura; Carof, Antoine; Blumberger, Jochen

    2016-12-22

    We investigate the performance of fewest switches surface hopping (SH) in describing electron transfer (ET) for a molecular donor-acceptor system. Computer simulations are carried out for a wide range of reorganisation energy (λ), electronic coupling strength (Hab) and driving force using our recently developed fragment orbital-based SH approach augmented with a simple decoherence correction. This methodology allows us to compute SH ET rates over more than four orders of magnitude, from the sub-picosecond to the nanosecond time regime. We find good agreement with semi-classical ET theory in the non-adiabatic ET regime. The correct scaling of the SH ET rate with electronic coupling strength is obtained and the Marcus inverted regime is reproduced, in line with previously reported results for a spin-boson model. Yet, we find that the SH ET rate falls below the semi-classical ET rate in the adiabatic regime, where the free energy barrier is in the order of kBT in our simulations. We explain this by first signatures of non-exponential population decay of the initial charge state. For even larger electronic couplings (Hab = λ/2), the free energy barrier vanishes and ET rates are no longer defined. At this point we observe a crossover from ET on the vibronic time scale to charge relaxation on the femtosecond time scale that is well described by thermally averaged Rabi oscillations. The extension of the analysis from the non-adiabatic limit to large electronic couplings and small or even vanishing activation barriers is relevant for our understanding of charge transport in organic semiconductors.

  9. Glycodermorphins: opioid peptides with potent and prolonged analgesic activity and enhanced blood-brain barrier penetration

    PubMed Central

    Negri, Lucia; Lattanzi, Roberta; Tabacco, Fabio; Scolaro, Barbara; Rocchi, Raniero

    1998-01-01

    In order to improve the in vivo stability of the opioid peptide dermorphin we synthesized O-βglucosylated analogs ([Ser7-O-βGlc]dermorphin and [Ser7-O-βGlc(Ac)4]-dermorphin) and C-αgalactosylated analogs ([Ala7-C-αGal]dermorphin and [Ala7-C-αGal(Ac)4]-dermorphin).O- and C-glycosylation of dermorphin halved the peptide affinity for brain μ-opioid receptors and the biological potency in guinea-pig ileum assay (GPI). Despite their lower opioid receptor affinity, when administered intracerebroventricularly (i.c.v., 8–40 pmol) and subcutaneously (s.c., 0.5–3 μmol kg−1) in rats, glycosylated analogs were two times more potent than dermorphin in reducing the nociceptive response to radiant heat. Acetylation of sugar hydroxyl groups reduces 5–10 times both biological activity on GPI and μ-receptor affinity, whereas the antinociceptive potency was equal to (i.c.v.) or only two-three times lower (s.c.) than dermorphin potency.Blood-Brain Barrier Permeability Index (BBB-PI) of the glycodermorphins was significantly higher than that of dermorphin, indicating a facilitated entry into the brain: O-β-linked glucoconiugates are expected to enter CNS by the glucose transporter GLUT-1 of the endothelial barrier. However the calculated BBB-PI for the C-αgalactoside was about two times higher than that of the O-βglucoside, excluding the implication of GLUT-1 that is known to be selective for O-β-links and preferring for the exose glucose.The enhanced brain permeability with the subsequent decrease in peripheral dosage of these opioid peptides did not result in lowering constipation. PMID:9723966

  10. HOPS: a novel cAMP-dependent shuttling protein involved in protein synthesis regulation.

    PubMed

    Della Fazia, Maria Agnese; Castelli, Marilena; Bartoli, Daniela; Pieroni, Stefania; Pettirossi, Valentina; Piobbico, Danilo; Viola-Magni, Mariapia; Servillo, Giuseppe

    2005-07-15

    The liver has the ability to autonomously regulate growth and mass. Following partial hepatectomy, hormones, growth factors, cytokines and their coupled signal transduction pathways have been implicated in hepatocyte proliferation. To understand the mechanisms responsible for the proliferative response, we studied liver regeneration by characterization of novel genes that are activated in residual hepatocytes. A regenerating liver cDNA library screening was performed with cDNA-subtracted probes derived from regenerating and normal liver. Here, we describe the biology of Hops (for hepatocyte odd protein shuttling). HOPS is a novel shuttling protein that contains an ubiquitin-like domain, a putative NES and a proline-rich region. HOPS is rapidly exported from the nucleus and is overexpressed during liver regeneration. Evidence shows that cAMP governs HOPS export in hepatocytes of normal and regenerating liver and is mediated via CRM-1. We demonstrate that HOPS binds to elongation factor eEF-1A and interferes in protein synthesis. HOPS overexpression in H-35-hepatoma and 3T3-NIH cells strongly reduces proliferation.

  11. The 1963 Hip-Hop Machine: Hip-Hop Pedagogy as Composition.

    ERIC Educational Resources Information Center

    Rice, Jeff

    2003-01-01

    Proposes an alternative invention strategy for research-based argumentative writing. Investigates the coincidental usage of the term "whatever" in hip-hop, theory, and composition studies. Presents a "whatever-pedagogy" identified as "hip-hop pedagogy," a writing practice that models itself after digital sampling's…

  12. HIP HOP for HIV Awareness: Using Hip Hop Culture to Promote Community-Level HIV Prevention

    ERIC Educational Resources Information Center

    Hill, Mandy J.; Hallmark, Camden J.; McNeese, Marlene; Blue, Nike; Ross, Michael W.

    2014-01-01

    The goal of this paper was to determine the effectiveness of the HIP HOP for HIV Awareness intervention, an innovative model utilising an exchange of an HIV test for a hip hop concert ticket, in a metropolitan city among African American youth and young adults. A subset of intervention participants participated in standardised testing, sex…

  13. Lack of facilities rather than sociocultural factors as the primary barrier to physical activity among female Saudi university students

    PubMed Central

    Samara, Anastasia; Nistrup, Anne; AL-Rammah, Tamader Y; Aro, Arja R

    2015-01-01

    Purpose The Kingdom of Saudi Arabia is experiencing a dramatic increase in physical inactivity, with women having higher levels of inactivity than men among all age groups. It is assumed that factors such as dress codes, restrictions on going outdoors, and conservative norms are the main reasons for women’s low physical activity. Our aim was to explore the different parameters related to physical activity, including self-efficacy, as well as the perceived barriers to and benefits of physical activity in young Saudi females. Patients and methods Ninety-four first-year female Saudi university students in Riyadh, Kingdom of Saudi Arabia, participated in the present study in 2014. The students were from eight bachelor’s programs in health and well-being, and each completed a questionnaire with questions divided into five parts as follows: 1) socioeconomic status, 2) physical activity, 3) self-efficacy 4) social factors, and 5) barriers and facilitators related to physical activity. Results The students exercised at home and alone, and there was low self-efficacy for physical activity (mean score =42±14). Among social factors, attending university was the only factor that hindered physical activity (32%). Physical activity was positively perceived overall (mean score =131±10). Students showed awareness of the benefits of physical activity for health and well-being. The most important barrier was the lack of designated areas available for physical activity. Students disagreed that family or the Islamic community were barriers to physical activity. Conclusion The lack of facilities and lack of encouragement from the university, but not a lack of knowledge (a high level of knowledge is to be expected given their health and well-being studies backgrounds) and/or restrictions from families and society, seem to hinder female students’ physical activity, at least young Saudi students. PMID:25834468

  14. Solid-phase microextraction of hop volatiles. Potential use for determination and verification of hop varieties.

    PubMed

    Kovacevic, M; Kac, M

    2001-05-18

    The composition of hop essential oil is an important tool for evaluation of hop quality. As each hop variety has a typical essential oil pattern (fingerprint), hop oil analyses can be used to distinguish between hop varieties. The headspace solid-phase microextraction (SPME) method as described in this contribution is a simple sample preparation technique and represents an alternative procedure for essential oil fingerprint determination. Different SPME parameters (extraction temperature, extraction time and sample mass) were studied and the results were compared with those obtained by the routine distillation method. It is shown that SPME results can be used for determination and verification of varieties grown in Slovenia by means of principal components analysis.

  15. Dynamic molecular graphs: "hopping" structures.

    PubMed

    Cortés-Guzmán, Fernando; Rocha-Rinza, Tomas; Guevara-Vela, José Manuel; Cuevas, Gabriel; Gómez, Rosa María

    2014-05-05

    This work aims to contribute to the discussion about the suitability of bond paths and bond-critical points as indicators of chemical bonding defined within the theoretical framework of the quantum theory of atoms in molecules. For this purpose, we consider the temporal evolution of the molecular structure of [Fe{C(CH2 )3 }(CO)3 ] throughout Born-Oppenheimer molecular dynamics (BOMD), which illustrates the changing behaviour of the molecular graph (MG) of an electronic system. Several MGs with significant lifespans are observed across the BOMD simulations. The bond paths between the trimethylenemethane and the metallic core are uninterruptedly formed and broken. This situation is reminiscent of a "hopping" ligand over the iron atom. The molecular graph wherein the bonding between trimethylenemethane and the iron atom takes place only by means of the tertiary carbon atom has the longest lifespan of all the considered structures, which is consistent with the MG found by X-ray diffraction experiments and quantum chemical calculations. In contrast, the η(4) complex predicted by molecular-orbital theory has an extremely brief lifetime. The lifespan of different molecular structures is related to bond descriptors on the basis of the topology of the electron density such as the ellipticities at the FeCH2 bond-critical points and electron delocalisation indices. This work also proposes the concept of a dynamic molecular graph composed of the different structures found throughout the BOMD trajectories in analogy to a resonance hybrid of Lewis structures. It is our hope that the notion of dynamic molecular graphs will prove useful in the discussion of electronic systems, in particular for those in which analysis on the basis of static structures leads to controversial conclusions.

  16. The Pseudomonas syringae effector HopQ1 promotes bacterial virulence and interacts with tomato 14-3-3 proteins in a phosphorylation-dependent manner.

    PubMed

    Li, Wei; Yadeta, Koste A; Elmore, James Mitch; Coaker, Gitta

    2013-04-01

    A key virulence strategy of bacterial pathogens is the delivery of multiple pathogen effector proteins into host cells during infection. The Hrp outer protein Q (HopQ1) effector from Pseudomonas syringae pv tomato (Pto) strain DC3000 is conserved across multiple bacterial plant pathogens. Here, we investigated the virulence function and host targets of HopQ1 in tomato (Solanum lycopersicum). Transgenic tomato lines expressing dexamethasone-inducible HopQ1 exhibited enhanced disease susceptibility to virulent Pto DC3000, the Pto ΔhrcC mutant, and decreased expression of a pathogen-associated molecular pattern-triggered marker gene after bacterial inoculation. HopQ1-interacting proteins were coimmunoprecipitated and identified by mass spectrometry. HopQ1 can associate with multiple tomato 14-3-3 proteins, including TFT1 and TFT5. HopQ1 is phosphorylated in tomato, and four phosphorylated peptides were identified by mass spectrometry. HopQ1 possesses a conserved mode I 14-3-3 binding motif whose serine-51 residue is phosphorylated in tomato and regulates its association with TFT1 and TFT5. Confocal microscopy and fractionation reveal that HopQ1 exhibits nucleocytoplasmic localization, while HopQ1 dephosphorylation mimics exhibit more pronounced nuclear localization. HopQ1 delivered from Pto DC3000 was found to promote bacterial virulence in the tomato genotype Rio Grande 76R. However, the HopQ1(S51A) mutant delivered from Pto DC3000 was unable to promote pathogen virulence. Taken together, our data demonstrate that HopQ1 enhances bacterial virulence and associates with tomato 14-3-3 proteins in a phosphorylation-dependent manner that influences HopQ1's subcellular localization and virulence-promoting activities in planta.

  17. Outdoor Built Environment Barriers and Facilitators to Activity among Midlife and Older Adults with Mobility Disabilities

    PubMed Central

    Rosenberg, Dori E.

    2013-01-01

    Purpose: To gain better understanding of how the built environment impacts neighborhood-based physical activity among midlife and older adults with mobility disabilities. Design and methods: We conducted in-depth interviews with 35 adults over age 50, which used an assistive device and lived in King County, Washington, U.S. In addition, participants wore Global Positioning Systems (GPS) devices for 3 days prior to the interview. The GPS maps were used as prompts during the interviews. Open coding of the 35 interviews using latent content analysis resulted in key themes and subthemes that achieved consensus between coders. Two investigators independently coded the text of each interview. Results: Participants were on average of 67 years of age (range: 50–86) and predominantly used canes (57%), walkers (57%), or wheelchairs (46%). Key themes pertained to curb ramp availability and condition, sidewalk availability and condition, hills, aesthetics, lighting, ramp availability, weather, presence and features of crosswalks, availability of resting places and shelter on streets, paved or smooth walking paths, safety, and traffic on roads. Implications: A variety of built environment barriers and facilitators to neighborhood-based activity exist for midlife and older adults with mobility disabilities. Preparing our neighborhood environments for an aging population that uses assistive devices will be important to foster independence and health. PMID:23010096

  18. Adherence to highly active antiretroviral therapy in Hyderabad, India: barriers, facilitators and identification of target groups.

    PubMed

    Dworkin, Mark S; Douglas, G W; Sabitha Rani, G P; Chakraborty, Apurba

    2016-03-01

    We assessed the barriers and facilitators to highly active antiretroviral therapy adherence and determined their prevalence among HIV/AIDS patients in Hyderabad, India. We conducted a cross-sectional study among HIV-infected adults prescribed highly active antiretroviral therapy and receiving care from nine clinics. Depression was screened using Patient Health Questionnaire 9 and facilitators of HIV medication adherence were assessed using an 11-item scale which yielded a total positive attitude to disease score. Prevalence ratios of non-adherence between different categories of potential risk factors were calculated. We compared mean 'facilitators to adherence' scores between the adherent and non-adherent population. Multivariable Poisson regression with robust variance was used to identify independent risk factors. Among the 211 respondents, nearly 20% were non-adherent, approximately 8% had either moderately severe or severe depression and mean score for combined facilitators to medication adherence was 33.35 (±7.88) out of a possible 44 points. Factors significantly associated with non-adherence included older age, female sex worker, moderate-to-severe depression and the combined facilitators to medication adherence score. These data from a broad range of clinical settings in Hyderabad reveal that key groups to focus on for adherence intervention are female sex workers, older persons and those with depression.

  19. SPATIAL HETEROGENEITY OF PHOTOSYNTHETIC ACTIVITY WITHIN DISEASED CORALS FROM THE GREAT BARRIER REEF(1).

    PubMed

    Roff, George; Ulstrup, Karin E; Fine, Maoz; Ralph, Peter J; Hoegh-Guldberg, Ove

    2008-04-01

    Morphological diagnosis and descriptions of seven disease-like syndromes affecting scleractinian corals were characterized from the southern Great Barrier Reef (GBR). Chl a fluorescence of PSII was measured using an Imaging-PAM (pulse amplitude modulated) fluorometer, enabling visualization of the two-dimensional variability in the photophysiology of endosymbiotic dinoflagellates (zooxanthellae) by measuring rapid light curves. Three of four syndromes associated with active tissue loss (type a) were spatially homogenous (white syndrome, brown band, and skeletal eroding band), with no impact on the photochemical function of zooxanthellae populations at or behind the lesion borders. However, a decline in maximum quantum yield (Fv /Fm ) and elevated levels of maximum nonphotochemical quenching (NPQmax ) occurred in visually healthy tissue of black band disease adjacent to the lesion borders, possibly due to hypoxic conditions caused by the black band cyanobacterial mat. Two out of three syndromes associated with pathological change of intact tissue with no active tissue loss (type b) showed variable photophysiological responses (neoplasia and pigmentation response). Only the bleached foci associated with white patch syndrome appeared to impact primarily on the symbiotic dinoflagellates, as evidenced by declines in minimum fluorescence (F0 ) and maximum quantum yield (Fv /Fm ), with no indication of degeneration in the host tissues. Our results suggest that for the majority of coral syndromes from the GBR, pathogenesis occurs in the host tissue, while the impact on the zooxanthellae populations residing in affected corals is minimal.

  20. Facilitators and barriers to HIV activities in religious congregations: perspectives of clergy and lay leaders from a diverse urban sample.

    PubMed

    Mendel, Peter; Derose, Kathryn Pitkin; Werber, Laura; Palar, Kartika; Kanouse, David E; Mata, Michael

    2014-10-01

    This paper examines facilitators and barriers to HIV activities within religious congregations, the relative internal or external sources of these influences, and suggestive differences across congregational types. Results are based on in-depth interviews with clergy and lay leaders (n = 57) from 14 congregations in Los Angeles County, California, purposively selected to reflect diversity in racial-ethnic composition, denomination, size, and HIV activity level. Many common facilitators and barriers were related to norms and attitudes, only a few of which appeared overtly associated with theological orientations. Clergy support was a facilitator particularly prevalent among congregations having higher HIV activity levels, indicating its importance in sustaining and expanding HIV programs. Resource issues were also prominent, with material resource barriers more frequently mentioned by smaller congregations and human resource barriers more among larger congregations. Organizational structure issues were mostly centered on external linkages with various social service, public health, and faith-based entities. Analysis of internal versus external sources highlights the roles of different stakeholders within and outside congregations in promoting HIV activities. Potential differences across congregational types represent fruitful areas for future research.

  1. Barriers to and Suggestions for a Healthful, Active Lifestyle as Perceived by Rural and Urban Costa Rican Adolescents

    ERIC Educational Resources Information Center

    Monge-Rojas, Rafael; Garita-Arce, Carlos; Sanchez-Lopez, Marta; Colon-Ramos, Uriyoan

    2009-01-01

    Objective: To assess the perceptions of rural and urban Costa Rican adolescents regarding which barriers and motivators affect their adoption of an active lifestyle. Design: Data were collected in focus group discussions. Participants: 108 male and female adolescents aged 12 to 18 from the 7th to 11th grades. Setting: Two urban and 1 rural high…

  2. A Near-Infrared Laser-Activated "Nanobomb" for Breaking the Barriers to MicroRNA Delivery.

    PubMed

    Wang, Hai; Agarwal, Pranay; Zhao, Shuting; Yu, Jianhua; Lu, Xiongbin; He, Xiaoming

    2016-01-13

    A near-infrared laser-activated "nanobomb" is synthesized using lipid and multiple polymers to break the extra-cellular and intracellular barriers to cytosolic delivery of microRNAs. The nanobomb can be used to effectively destroy tumors and cancer stem-like cells in vitro and in vivo with minimal side effects.

  3. Facilitators and Barriers to HIV Activities in Religious Congregations: Perspectives of Clergy and Lay Leaders from a Diverse Urban Sample

    PubMed Central

    Derose, Kathryn Pitkin; Werber, Laura; Palar, Kartika; Kanouse, David E.; Mata, Michael

    2013-01-01

    This paper examines facilitators and barriers to HIV activities within religious congregations, the relative internal or external sources of these influences, and suggestive differences across congregational types. Results are based on in-depth interviews with clergy and lay leaders (n = 57) from 14 congregations in Los Angeles County, California, purposively selected to reflect diversity in racial-ethnic composition, denomination, size, and HIV activity level. Many common facilitators and barriers were related to norms and attitudes, only a few of which appeared overtly associated with theological orientations. Clergy support was a facilitator particularly prevalent among congregations having higher HIV activity levels, indicating its importance in sustaining and expanding HIV programs. Resource issues were also prominent, with material resource barriers more frequently mentioned by smaller congregations and human resource barriers more among larger congregations. Organizational structure issues were mostly centered on external linkages with various social service, public health, and faith-based entities. Analysis of internal versus external sources highlights the roles of different stakeholders within and outside congregations in promoting HIV activities. Potential differences across congregational types represent fruitful areas for future research. PMID:23990037

  4. Brain Distribution of Cediranib Is Limited by Active Efflux at the Blood-Brain Barrier

    PubMed Central

    Wang, Tianli; Agarwal, Sagar

    2012-01-01

    Cediranib is an orally active tyrosine kinase inhibitor that targets the vascular endothelial growth factor receptor family. Because of its potent antiangiogenic and antitumor activities, cediranib has been evaluated for therapy in glioma, a primary brain tumor. This study investigated the influence of two important efflux transporters at the blood-brain barrier, P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp), on the delivery of cediranib to the central nervous system. In vitro studies indicated that cediranib is a dual substrate for both P-gp and Bcrp. It is noteworthy that in spite of the in vitro data the in vivo mouse disposition studies conclusively showed that P-gp was the dominant transporter restricting the brain distribution of cediranib. The brain-to-plasma partitioning (AUCbrain/AUCplasma, where AUC is area under the curve) and the steady-state brain-to-plasma concentration ratio of cediranib were approximately 20-fold higher in Mdr1a/b(−/−) and Mdr1a/b(−/−)Bcrp1(−/−) mice compared with wild-type and Bcrp1(−/−) mice. Moreover, there was no significant difference in brain distribution of cediranib between wild-type and Bcrp1(−/−) mice and between Mdr1a/b(−/−) and Mdr1a/b(−/−)Bcrp1(−/−) mice. These results show that, unlike other tyrosine kinase inhibitors that are dual substrates for P-gp and Bcrp, Bcrp does not restrict the distribution of cediranib across the blood-brain barrier. We also show that inhibition of P-gp using specific or nonspecific inhibitors resulted in significantly enhanced delivery of cediranib to the brain. Concurrent administration of cediranib with chemical modulators of efflux transporters can be used as a strategy to enhance delivery and thus efficacy of cediranib in the brain. These findings are clinically relevant to the efficacy of cediranib chemotherapy in glioma. PMID:22323823

  5. Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis by inhibiting the activation of nuclear factor-kappa B

    SciTech Connect

    Cheng, Jian; Zhang, Lin; Dai, Weiqi; Mao, Yuqing; Li, Sainan; Wang, Jingjie; Li, Huanqing; Guo, Chuanyong; Fan, Xiaoming

    2015-02-27

    Aim: This study aimed to investigate the effect and underlying mechanism of ghrelin on intestinal barrier dysfunction in dextran sulfate sodium (DSS)-induced colitis. Methods and results: Acute colitis was induced in C57BL/6J mice by administering 2.5% DSS. Saline or 25, 125, 250 μg/kg ghrelin was administrated intraperitoneally (IP) to mice 1 day before colitis induction and on days 4, 5, and 6 after DSS administration. IP injection of a ghrelin receptor antagonist, [D-lys{sup 3}]-GHRP-6, was performed immediately prior to ghrelin injection. Ghrelin (125 or 250 μg/kg) could reduce the disease activity index, histological score, and myeloperoxidase activities in experimental colitis, and also prevented shortening of the colon. Ghrelin could prevent the reduction of transepithelial electrical resistance and tight junction expression, and bolstered tight junction structural integrity and regulated cytokine secretion. Ultimately, ghrelin inhibited nuclear factor kappa B (NF-κB), inhibitory κB-α, myosin light chain kinase, and phosphorylated myosin light chain 2 activation. Conclusions: Ghrelin prevented the breakdown of intestinal barrier function in DSS-induced colitis. The protective effects of ghrelin on intestinal barrier function were mediated by its receptor GHSR-1a. The inhibition of NF-κB activation might be part of the mechanism underlying the effects of ghrelin that protect against barrier dysfunction. - Highlights: • Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis. • The effect of ghrelin is mediated by GHSR-1a. • Inhibition of NF-κB activation.

  6. Dissipated power and induced velocity fields data of a micro single dielectric barrier discharge plasma actuator for active flow control.

    PubMed

    Pescini, E; Martínez, D S; De Giorgi, M G; Francioso, L; Ficarella, A

    2015-12-01

    In recent years, single dielectric barrier discharge (SDBD) plasma actuators have gained great interest among all the active flow control devices typically employed in aerospace and turbomachinery applications [1,2]. Compared with the macro SDBDs, the micro single dielectric barrier discharge (MSDBD) actuators showed a higher efficiency in conversion of input electrical power to delivered mechanical power [3,4]. This article provides data regarding the performances of a MSDBD plasma actuator [5,6]. The power dissipation values [5] and the experimental and numerical induced velocity fields [6] are provided. The present data support and enrich the research article entitled "Optimization of micro single dielectric barrier discharge plasma actuator models based on experimental velocity and body force fields" by Pescini et al. [6].

  7. Dissipated power and induced velocity fields data of a micro single dielectric barrier discharge plasma actuator for active flow control☆

    PubMed Central

    Pescini, E.; Martínez, D.S.; De Giorgi, M.G.; Francioso, L.; Ficarella, A.

    2015-01-01

    In recent years, single dielectric barrier discharge (SDBD) plasma actuators have gained great interest among all the active flow control devices typically employed in aerospace and turbomachinery applications [1,2]. Compared with the macro SDBDs, the micro single dielectric barrier discharge (MSDBD) actuators showed a higher efficiency in conversion of input electrical power to delivered mechanical power [3,4]. This article provides data regarding the performances of a MSDBD plasma actuator [5,6]. The power dissipation values [5] and the experimental and numerical induced velocity fields [6] are provided. The present data support and enrich the research article entitled “Optimization of micro single dielectric barrier discharge plasma actuator models based on experimental velocity and body force fields” by Pescini et al. [6]. PMID:26425667

  8. Blood-brain barrier permeability mechanisms in view of quantitative structure-activity relationships (QSAR).

    PubMed

    Bujak, Renata; Struck-Lewicka, Wiktoria; Kaliszan, Michał; Kaliszan, Roman; Markuszewski, Michał J

    2015-04-10

    The goal of the present paper was to develop a quantitative structure-activity relationship (QSAR) method using a simple statistical approach, such as multiple linear regression (MLR) for predicting the blood-brain barrier (BBB) permeability of chemical compounds. The "best" MLR models, comprised logP and either molecular mass (M) or isolated atomic energy (E(isol)), tested on a structurally diverse set of 66 compounds, is characterized the by correlation coefficients (R) around 0.8. The obtained models were validated using leave-one-out (LOO) cross-validation technique and the correlation coefficient of leave-one-out- R(LOO)(2) (Q(2)) was at least 0.6. Analysis of a case from legal medicine demonstrated informative value of our QSAR model. To best authors' knowledge the present study is a first application of the developed QSAR models of BBB permeability to case from the legal medicine. Our data indicate that molecular energy-related descriptors, in combination with the well-known descriptors of lipophilicity may have a supportive value in predicting blood-brain distribution, which is of utmost importance in drug development and toxicological studies.

  9. SEMA4D compromises blood-brain barrier, activates microglia, and inhibits remyelination in neurodegenerative disease.

    PubMed

    Smith, Ernest S; Jonason, Alan; Reilly, Christine; Veeraraghavan, Janaki; Fisher, Terrence; Doherty, Michael; Klimatcheva, Ekaterina; Mallow, Crystal; Cornelius, Chad; Leonard, John E; Marchi, Nicola; Janigro, Damir; Argaw, Azeb Tadesse; Pham, Trinh; Seils, Jennifer; Bussler, Holm; Torno, Sebold; Kirk, Renee; Howell, Alan; Evans, Elizabeth E; Paris, Mark; Bowers, William J; John, Gareth; Zauderer, Maurice

    2015-01-01

    Multiple sclerosis (MS) is a chronic neuroinflammatory disease characterized by immune cell infiltration of CNS, blood-brain barrier (BBB) breakdown, localized myelin destruction, and progressive neuronal degeneration. There exists a significant need to identify novel therapeutic targets and strategies that effectively and safely disrupt and even reverse disease pathophysiology. Signaling cascades initiated by semaphorin 4D (SEMA4D) induce glial activation, neuronal process collapse, inhibit migration and differentiation of oligodendrocyte precursor cells (OPCs), and disrupt endothelial tight junctions forming the BBB. To target SEMA4D, we generated a monoclonal antibody that recognizes mouse, rat, monkey and human SEMA4D with high affinity and blocks interaction between SEMA4D and its cognate receptors. In vitro, anti-SEMA4D reverses the inhibitory effects of recombinant SEMA4D on OPC survival and differentiation. In vivo, anti-SEMA4D significantly attenuates experimental autoimmune encephalomyelitis in multiple rodent models by preserving BBB integrity and axonal myelination and can be shown to promote migration of OPC to the site of lesions and improve myelin status following chemically-induced demyelination. Our study underscores SEMA4D as a key factor in CNS disease and supports the further development of antibody-based inhibition of SEMA4D as a novel therapeutic strategy for MS and other neurologic diseases with evidence of demyelination and/or compromise to the neurovascular unit.

  10. Degradation of triclosan in aqueous solution by dielectric barrier discharge plasma combined with activated carbon fibers.

    PubMed

    Xin, Lu; Sun, Yabing; Feng, Jingwei; Wang, Jian; He, Dong

    2016-02-01

    The degradation of triclosan (TCS) in aqueous solution by dielectric barrier discharge (DBD) plasma with activated carbon fibers (ACFs) was investigated. In this study, ACFs and DBD plasma coexisted in a planar DBD plasma reactor, which could synchronously achieve degradation of TCS, modification and in situ regeneration of ACFs, enhancing the effect of recycling of ACFs. The properties of ACFs before and after modification by DBD plasma were characterized by BET and XPS. Various processing parameters affecting the synergetic degradation of TCS were also investigated. The results exhibited excellent synergetic effects in DBD plasma-ACFs system on TCS degradation. The degradation efficiency of 120 mL TCS with initial concentration of 10 mg L(-1) could reach 93% with 1 mm thick ACFs in 18 min at input power of 80 W, compared with 85% by single DBD plasma. Meanwhile, the removal rate of total organic carbon increased from 12% at pH 6.26-24% at pH 3.50. ACFs could ameliorate the degradation efficiency for planar DBD plasma when treating TCS solution at high flow rates or at low initial concentrations. A possible degradation pathway of TCS was investigated according to the detected intermediates, which were identified by liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) combined with theoretical calculation of Gaussian 09 program.

  11. Comparison Between Dielectric Barrier Discharge Plasma and Ozone Regenerations of Activated Carbon Exhausted with Pentachlorophenol

    NASA Astrophysics Data System (ADS)

    Qu, Guangzhou; Liang, Dongli; Qu, Dong; Huang, Yimei; Li, Jie

    2014-06-01

    In this study, two regeneration methods (dielectric barrier discharge (DBD) plasma and ozone (O3) regeneration) of saturated granular activated carbon (GAC) with pentachlorophenol (PCP) were compared. The results show that the two regeneration methods can eliminate contaminants from GAC and recover its adsorption properties to some extent. Comparing the DBD plasma with O3 regeneration, the adsorption rate and the capacity of the GAC samples after DBD plasma regeneration are greater than those after O3 regeneration. O3 regeneration decreases the specific surface area of GAC and increases the acidic surface oxygen groups on the surface of GAC, which causes a decrease in PCP on GAC uptake. With increasing regeneration cycles, the regeneration efficiencies of the two methods decrease, but the decrease in the regeneration efficiencies of GAC after O3 regeneration is very obvious compared with that after DBD plasma regeneration. Furthermore, the equilibrium data were fitted by the Freundlich and Langmuir models using the non-linear regression technique, and all the adsorption equilibrium isotherms fit the Langmuir model fairly well, which demonstrates that the DBD plasma and ozone regeneration processes do not appear to modify the adsorption process, but to shift the equilibrium towards lower adsorption concentrations. Analyses of the weight loss of GAC show that O3 regeneration has a lower weight loss than DBD plasma regeneration.

  12. Molecular variation of hop mosaic virus isolates.

    PubMed

    Poke, Fiona S; Crowle, Damian R; Whittock, Simon P; Wilson, Calum R

    2010-10-01

    Hop mosaic virus (HpMV), a member of the genus Carlavirus, is importance to hop production worldwide. We identified variation in nucleic and amino acid sequences among 23 HpMV isolates from Australia, the USA, the Czech Republic, South Africa and Japan using a 1,455-bp fragment covering the 3' end of the virus genome including ORFs 4, 5 and 6. Three clusters of two or more isolates were identified in phylogenies of the total nucleotide sequence and the coat protein (ORF5) amino acid sequence. Two of these clusters combined in analyses of ORF4 and ORF6 amino acid sequences. Isolates from within and outside of Australia were found in each cluster, indicating that sequence variation was not associated with geographic source. Monitoring of HpMV variants in the field and evaluation of the impact of variants on vector association, rate of spread, and hop yield and quality can now be undertaken.

  13. Landau-Zener type surface hopping algorithms.

    PubMed

    Belyaev, Andrey K; Lasser, Caroline; Trigila, Giulio

    2014-06-14

    A class of surface hopping algorithms is studied comparing two recent Landau-Zener (LZ) formulas for the probability of nonadiabatic transitions. One of the formulas requires a diabatic representation of the potential matrix while the other one depends only on the adiabatic potential energy surfaces. For each classical trajectory, the nonadiabatic transitions take place only when the surface gap attains a local minimum. Numerical experiments are performed with deterministically branching trajectories and with probabilistic surface hopping. The deterministic and the probabilistic approach confirm the affinity of both the LZ probabilities, as well as the good approximation of the reference solution computed by solving the Schrödinger equation via a grid based pseudo-spectral method. Visualizations of position expectations and superimposed surface hopping trajectories with reference position densities illustrate the effective dynamics of the investigated algorithms.

  14. How does a hopping kangaroo breathe?

    PubMed

    Giuliodori, Mauricio J; Lujan, Heidi L; Janbaih, Hussein; DiCarlo, Stephen E

    2010-12-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the abdominal organs "flop" within the kangaroo's body. Specifically, as the kangaroo hops upward, the abdominal organs lag behind, and the insertion of the diaphragm is pulled toward its origin, flattening the dome and increasing the vertical dimension of the thoracic cavity (the thoracic cavity and lungs enlarge). Increasing the volume of the thoracic cavity reduces alveolar pressure below atmospheric pressure (barometric pressure), and air moves into the alveoli by bulk flow. In contrast, the impact of the organs against the diaphragm at each landing causes expiration. Specifically, upon landing, the abdominal organs flop into the diaphragm, causing it to return to its dome shape and decreasing the vertical dimension of the thoracic cavity. This compresses the alveolar gas volume and elevates alveolar pressure above barometric pressure, so air is expelled. To demonstrate this phenomenon, the plunger of a syringe model of the respiratory system was inserted through a compression spring. Holding the syringe and pressing the plunger firmly against a hard surface expels air from the lungs (the balloon within the syringe deflates) and compresses the spring. This models the kangaroo landing after a hop forward. Subsequently, the compression spring provides the energy for the "kangaroo" to "hop" forward upon the release of the syringe, and air enters the lungs (the balloon within the syringe inflates). The model accurately reflects how a hopping kangaroo breathes. A model was chosen to demonstrate this phenomenon because models engage and inspire students as well as significantly enhance student understanding.

  15. Parents' Perceived Barriers to Healthful Eating and Physical Activity for Low-Income Adolescents Who Are at Risk for Type 2 Diabetes

    ERIC Educational Resources Information Center

    Peterson, Sharon L.; Bell, Toya Wilson; Hasin, Afroza

    2009-01-01

    Healthful eating and regular physical activity are vitally important for low-income adolescents who are at risk for developing type 2 diabetes (T2DM). To design a relevant, community-based intervention for these at risk adolescents, parent perceptions of barriers to healthful eating and physical activity should be assessed. Such barriers have been…

  16. Short-chain fatty acids activate AMP-activated protein kinase and ameliorate ethanol-induced intestinal barrier dysfunction in Caco-2 cell monolayers.

    PubMed

    Elamin, Elhaseen E; Masclee, Ad A; Dekker, Jan; Pieters, Harm-Jan; Jonkers, Daisy M

    2013-12-01

    Short-chain fatty acids (SCFAs) have been shown to promote intestinal barrier function, but their protective effects against ethanol-induced intestinal injury and underlying mechanisms remain essentially unknown. The aim of the study was to analyze the influence of SCFAs on ethanol-induced barrier dysfunction and to examine the role of AMP-activated protein kinase (AMPK) as a possible mechanism using Caco-2 monolayers. The monolayers were treated apically with butyrate (2, 10, or 20 mmol/L), propionate (4, 20, or 40 mmol/L), or acetate (8, 40, or 80 mmol/L) for 1 h before ethanol (40 mmol/L) for 3 h. Barrier function was analyzed by measurement of transepithelial resistance and permeation of fluorescein isothiocyanate-labeled dextran. Distribution of the tight junction (TJ) proteins zona occludens-1, occludin, and filamentous-actin (F-actin) was examined by immunofluorescence. Metabolic stress was determined by measuring oxidative stress, mitochondrial function, and ATP using dichlorofluorescein diacetate, dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide, and bioluminescence assay, respectively. AMPK was knocked down by small interfering RNA (siRNA), and its activity was assessed by a cell-based ELISA. Exposure to ethanol significantly impaired barrier function compared with controls (P < 0.0001), disrupted TJ and F-actin cytoskeleton integrity, and induced metabolic stress. However, pretreatment with 2 mmol/L butyrate, 4 mmol/L propionate, and 8 mmol/L acetate significantly alleviated the ethanol-induced barrier dysfunction, TJ and F-actin disruption, and metabolic stress compared with ethanol-exposed monolayers (P < 0.0001). The promoting effects on barrier function were abolished by inhibiting AMPK using either compound C or siRNA. These observations indicate that SCFAs exhibit protective effects against ethanol-induced barrier disruption via AMPK activation, suggesting a potential for SCFAs as prophylactic and/or therapeutic factors against ethanol

  17. Theory of electronic relaxation in solution in the absence of an activation barrier

    NASA Astrophysics Data System (ADS)

    Bagchi, Biman; Fleming, Graham R.; Oxtoby, David W.

    1983-06-01

    We present a theory which describes the effects of viscosity on those electronic relaxation processes in solution in which the intramolecular potential surface does not present a barrier to the motion leading to the decay of the initially formed excited state. We model the reactive motion as the motion of a solute particle on the excited state potential surface with a position dependent sink which gives rise to the decay of the excited state population. Three different types of sinks are considered: (A) a pinhole sink at the minimum of the potential surface; this models the situation when the molecule decays to ground state as soon as it reaches the potential minimum; (B) a Gaussian sink with probability of decay maximum at the potential minimum; (C) a Lorentzian sink with maximum decay at the potential minimum. For case (A) an explicit analytic solution is obtained for the decay rate, but for cases (B) and (C) we obtained the decay rate numerically. Model (A) predicts nonexponential decay at all viscosities except at long times when the decay is single exponential. For cases (B) and (C) the decay is single exponential at low viscosities but becomes multiexponential at high viscosities. We show that the experimentally observed fractional viscosity dependence of fluorescence quantum yield arises naturally in this theory due to the position dependence of the sink as well as due to the competition between radiative and nonradiative relaxation. Our model also predicts a crossover from an apparent negative (constant viscosity) activation energy at low viscosities to a positive activation energy at high viscosity. The physical significance of these results is discussed in light of the available experimental results on TPM dye relaxation. Some possible generalizations of our theory to more realistic cases are indicated.

  18. 5. VIEW OF SOUTH FACADE OF HOP BARN COMPLEX, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF SOUTH FACADE OF HOP BARN COMPLEX, LOOKING NORTH INTO THE 'FUEL BAY' (IN THE CENTER). - James W. Seavey Hop Driers, 0.6 mile East from junction of Highway 99 & Alexander Avenue, Corvallis, Benton County, OR

  19. 21. REMAINS OF HOP BAILING CHUTE ON SECOND FLOOR; THIS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. REMAINS OF HOP BAILING CHUTE ON SECOND FLOOR; THIS CHUTE EXTENDS TO THE GROUND FLOOR. - James W. Seavey Hop Driers, 0.6 mile East from junction of Highway 99 & Alexander Avenue, Corvallis, Benton County, OR

  20. 20. REMAINS OF HOP BAILING CHUTE ON GROUND FLOOR; THIS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. REMAINS OF HOP BAILING CHUTE ON GROUND FLOOR; THIS CHUTE EXTENDS TO THE SECOND FLOOR. - James W. Seavey Hop Driers, 0.6 mile East from junction of Highway 99 & Alexander Avenue, Corvallis, Benton County, OR

  1. Polymers for subterranean containment barriers for underground storage tanks (USTs). Letter report on FY 1992 activities

    SciTech Connect

    Heiser, J.H.; Colombo, P.; Clinton, J.

    1992-12-01

    The US Department of Energy (DOE) set up the Underground Storage Tank Integrated Demonstration Program (USTID) to demonstrate technologies for the retrieval and treatment of tank waste, and closure of underground storage tanks (USTs). There are more than 250 underground storage tanks throughout the DOE complex. These tanks contain a wide variety of wastes including high level, low level, transuranic, mixed and hazardous wastes. Many of the tanks have performed beyond the designed lifetime resulting in leakage and contamination of the local geologic media and groundwater. To mitigate this problem it has been proposed that an interim subterranean containment barrier be placed around the tanks. This would minimize or prevent future contamination of soil and groundwater in the event that further tank leakages occur before or during remediation. Use of interim subterranean barriers can also provide sufficient time to evaluate and select appropriate remediation alternatives. The DOE Hanford site was chosen as the demonstration site for containment barrier technologies. A panel of experts for the USTID was convened in February, 1992, to identify technologies for placement of subterranean barriers. The selection was based on the ability of candidate grouts to withstand high radiation doses, high temperatures and aggressive tank waste leachates. The group identified and ranked nine grouting technologies that have potential to place vertical barriers and five for horizontal barriers around the tank. The panel also endorsed placement technologies that require minimal excavation of soil surrounding the tanks.

  2. Ab initio trajectory surface-hopping study on ultrafast deactivation process of thiophene.

    PubMed

    Cui, Ganglong; Fang, Weihai

    2011-10-27

    The ultrafast S(1)((1)ππ*) → S(0) deactivation process of thiophene in the gas phase has been simulated with the complete active space self-consistent field (CASSCF) based fewest switch surface hopping method. It was found that most of the calculated trajectories (∼80%) decay to the ground state (S(0)) with an averaged time constant of 65 ± 5 fs. This is in good agreement with the experimental value of about 80 fs. Two conical intersections were determined to be responsible for the ultrafast S(1)((1)ππ*) → S(0) internal conversion process. After thiophene is excited to the S(1)((1)ππ*) state in the Franck-Condon region, it quickly relaxes to the minimum of the S(1)((1)ππ*) state, then overcomes a small barrier near the conical intersection (CI((1)ππ*/(1)πσ*)), and eventually arrives at the minimum of one C-S bond fission (S(1)((1)πσ*)). In the vicinity of this minimum, the conical intersection (CI((1)πσ*/S(0))) funnels the electron population to the ground state (S(0)), completing the ultrafast S(1)((1)ππ*) → S(0) internal conversion process. This decay mechanism matches well with previous experimental and theoretical studies.

  3. Mechanisms of cancer chemoprevention by hop bitter acids (beer aroma) through induction of apoptosis mediated by Fas and caspase cascades.

    PubMed

    Chen, Wei-Jen; Lin, Jen-Kun

    2004-01-14

    The bitter acids of hops (Humulus lupulus L.) mainly consist of alpha-acids, beta-acids, and their oxidation products that contribute the unique aroma of the beer beverage. Hop bitter acids displayed a strong growth inhibitory effect against human leukemia HL-60 cells, with an estimated IC(50) value of 8.67 microg/mL, but were less effective against human histolytic lymphoma U937 cells. Induction of apoptosis was confirmed in HL-60 cells by DNA fragmentation and the appearance of a sub-G1 DNA peak, which were preceded by dissipation of mitochondrial membrane potential, cytochrome c release, and subsequent induction of pro-caspase-9 and -3 processing. Cleavages of PARP and DFF-45 were accompanied with activation of caspase-9 and -3 triggered by hop bitter acids in HL-60 cells. The change in the expression of Bcl-2, Bcl-X(L), and Bax in response to hop bitter acids was studied, and the Bcl-2 protein level slightly decreased; however, the Bcl-X(L) protein level was obviously decreased, whereas the Bax protein level was dramatically increased, indicating that the control of Bcl-2 family proteins by hop bitter acids might participate in the disruption of mitochondrial integrity. In addition, the results showed that hop bitter acids promoted the up-regulation of Fas and FasL prior to the processing and activation of pro-caspase-8 and cleavage of Bid, suggesting the involvement of a Fas-mediated pathway in hop bitter acids-induced cells. Taken together, these findings suggest that a certain intimate link might exist between receptor- and mitochondria-mediated death signalings that committed to cell death induced by hop bitter acids. The induction of apoptosis by hop bitter acids may offer a pivotal mechanism for their chemopreventive action.

  4. Perceived Barriers, Facilitators and Benefits for Regular Physical Activity and Exercise in Patients with Rheumatoid Arthritis: A Review of the Literature.

    PubMed

    Veldhuijzen van Zanten, Jet J C S; Rouse, Peter C; Hale, Elizabeth D; Ntoumanis, Nikos; Metsios, George S; Duda, Joan L; Kitas, George D

    2015-10-01

    Rheumatoid arthritis (RA) is an autoimmune disease, which not only affects the joints but can also impact on general well-being and risk for cardiovascular disease. Regular physical activity and exercise in patients with RA have numerous health benefits. Nevertheless, the majority of patients with RA are physically inactive. This indicates that people with RA might experience additional or more severe barriers to physical activity or exercise than the general population. This narrative review provides an overview of perceived barriers, benefits and facilitators of physical activity and exercise in RA. Databases were searched for articles published until September 2014 using the terms 'rheumatoid arthritis', 'physical activity', 'exercise', 'barriers', 'facilitators', 'benefits', 'motivation', 'motivators' and 'enablers'. Similarities were found between disease-specific barriers and benefits of physical activity and exercise, e.g. pain and fatigue are frequently mentioned as barriers, but reductions in pain and fatigue are perceived benefits of physical activity and exercise. Even though exercise does not influence the existence of barriers, physically active patients appear to be more capable of overcoming them. Therefore, exercise programmes should enhance self-efficacy for exercise in order to achieve long-term physical activity and exercise behaviour. Encouragement from health professionals and friends/family are facilitators for physical activity and exercise. There is a need for interventions that support RA patients in overcoming barriers to physical activity and exercise and help sustain this important health behaviour.

  5. Ultra-high-performance liquid chromatography profiling method for chemical screening of proanthocyanidins in Czech hops.

    PubMed

    Olšovská, J; Kameník, Z; Čejka, P; Jurková, M; Mikyška, A

    2013-11-15

    Hops represent an important natural source of bioactive polyphenols, particularly proanthocyanidins, which can contribute to prevention of several civilization diseases, owing to their antioxidant and radical scavenging activity. We have developed a high-throughput ultra-high-performance liquid chromatography time-of-flight mass spectrometry profiling method, which can be used for monitoring of bioactive proanthocyanidins in hops. The method was applied for analysis of hops of four Czech varieties (Saaz, Sladek, Preminat and Agnus) from the 2011 crop (9 localities, 11 samples) and the 2012 crop (24 localities, 40 samples). Hop samples were extracted by acetone and the analytes were separated on the Acquity UPLC BEH Shield RP18 column. Partial validation of the method revealed a satisfactory intra-day repeatability of the method for retention times (relative standard deviation within 1.39%) as well as areas under the peaks (within 9.89%). Experimental data were evaluated using principal component analysis and cluster analysis. Significant amounts of di-, tri- and tetramer proanthocyanidins consisting of (epi)catechin and (epi)gallocatechin were found in the hop samples. The dependence of the proantocyanidin composition on both the variety and the growing locality was observed. Specifically, the traditional Saaz variety contained more frequently oligomers formed by (epi)catechin units only, whereas the varieties Premiant and Agnus produced oligomers consisting of (epi)catechin as well as (epi)gallocatechin units. The relative abundance of proanthocyanidins in studied hop varieties from the two crops, 2011 and 2012, did correspond to each other. In the further perspective, the method may also be used for prediction of qualitative marks or authenticity verification of hops.

  6. Revolutionizing Environmental Education through Indigenous Hip Hop Culture

    ERIC Educational Resources Information Center

    Gorlewski, Julie; Porfilio, Brad J.

    2012-01-01

    Based upon the life histories of six Indigenous hip hop artists of the Beat Nation artist collective, this essay captures how Indigenous hip hop has the potential to revolutionize environmental education. Hip hop provides Indigenous youth an emancipatory space to raise their opposition to neocolonial controls of Indigenous territories that…

  7. A Case Study: Significance, Epidemiology, and Management of Hop Viruses.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hop latent carlavirus (HpLV), Hop mosaic carlavirus (HpMV), and Apple mosaic ilarvirus (ApMV) are viruses that have been shown to have deleterious effects on cone yield and brewing organic acids in several cultivars in Australian hop gardens, and pose a significant threat to the continued production...

  8. 14. VIEW ON SECOND FLOOR OF HOP HAULING CAR FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW ON SECOND FLOOR OF HOP HAULING CAR FOR LOADING AND UNLOADING HOP DRYERS WHICH ARE LOCATED ON EITHER SIDE OF THE CART'S TRACK. - James W. Seavey Hop Driers, 0.6 mile East from junction of Highway 99 & Alexander Avenue, Corvallis, Benton County, OR

  9. Genomics of the hop psuedo-autosomal regions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hop is one of the few crop species with female and male plants with sex being determined by either XX or XY chromosomes. Hop cones are only produced in female hops with or without fertilization. This has lead to most genomic research being directed toward female plants. Very little work has been don...

  10. HPLC Analysis of [Alpha]- and [Beta]-Acids in Hops

    ERIC Educational Resources Information Center

    Danenhower, Travis M.; Force, Leyna J.; Petersen, Kenneth J.; Betts, Thomas A.; Baker, Gary A.

    2008-01-01

    Hops have been used for centuries to impart aroma and bitterness to beer. The cones of the female hop plant contain both essential oils, which include many of the fragrant components of hops, and a collection of compounds known as [alpha]- and [beta]-acids that are the precursors to bittering agents. In order for brewers to predict the ultimate…

  11. Suppression of Hop Looper (Lepidoptera: Noctuidae) by the fungicide Pyraclostrobin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hop looper, Hypena humuli Harris, is a reemergent pest of hop that often requires treatment to mitigate crop damage. In four years of field trials, plots treated with fungicides were observed to sustain less hop looper defoliation as compared to nontreated plots. Further investigation revealed...

  12. Hip-Hopping across China: Intercultural Formulations of Local Identities

    ERIC Educational Resources Information Center

    Barrett, Catrice

    2012-01-01

    The linguistic dimensions of globalized hip-hop cannot be understood simply as a byproduct of English as an American export. As hip-hop mobilizes, it is common (and arguably necessary) for global hip-hop communities to struggle through purposeful, semiotically rooted dialectics over what constitutes "authentic" and respectable forms of…

  13. The HOPS/class C Vps complex tethers membranes by binding to one Rab GTPase in each apposed membrane.

    PubMed

    Ho, Ruoya; Stroupe, Christopher

    2015-07-15

    Many Rab GTPase effectors are membrane-tethering factors, that is, they physically link two apposed membranes before intracellular membrane fusion. In this study, we investigate the distinct binding factors needed on apposed membranes for Rab effector-dependent tethering. We show that the homotypic fusion and protein-sorting/class C vacuole protein-sorting (HOPS/class C Vps) complex can tether low-curvature membranes, that is, liposomes with a diameter of ∼100 nm, only when the yeast vacuolar Rab GTPase Ypt7p is present in both tethered membranes. When HOPS is phosphorylated by the vacuolar casein kinase I, Yck3p, tethering only takes place when GTP-bound Ypt7p is present in both tethered membranes. When HOPS is not phosphorylated, however, its tethering activity shows little specificity for the nucleotide-binding state of Ypt7p. These results suggest a model for HOPS-mediated tethering in which HOPS tethers membranes by binding to Ypt7p in each of the two tethered membranes. Moreover, because vacuole-associated HOPS is presumably phosphorylated by Yck3p, our results suggest that nucleotide exchange of Ypt7p on multivesicular bodies (MVBs)/late endosomes must take place before HOPS can mediate tethering at vacuoles.

  14. Characterization of a dielectric barrier discharge in contact with liquid and producing a plasma activated water

    NASA Astrophysics Data System (ADS)

    Neretti, G.; Taglioli, M.; Colonna, G.; Borghi, C. A.

    2017-01-01

    In this work a low-temperature plasma source for the generation of plasma activated water (PAW) is developed and characterized. The plasma reactor was operated by means of an atmospheric-pressure air dielectric barrier discharge (DBD). The plasma generated is in contact with the water surface and is able to chemically activate the liquid medium. Electrodes were supplied by both sinusoidal and nanosecond-pulsed voltage waveforms. Treatment times were varied from 2 to 12 min to increase the energy dose released to the water by the DBD plasma. The physics of the discharge was studied by means of electrical, spectroscopic and imaging diagnostics. The interaction between the plasma and the liquid was investigated as well. Temperature and composition of the treated water were detected. Images of the discharges showed a filamentary behaviour in the sinusoidal case and a more homogeneous behaviour in the nanosecond-pulsed one. The images and the electrical measurements allowed to evaluate an average electron number density of about 4  ×  1019 and 6  ×  1017 m-3 for the sinusoidal and nanosecond-pulsed discharges respectively. Electron temperatures in the range of 2.1÷2.6 eV were measured by using spectroscopic diagnostics. Rotational temperatures in the range of 318-475 K were estimated by fitting synthetic spectra with the measured ones. Water temperature and pH level did not change significantly after the exposure to the DBD plasma. The production of ozone and hydrogen peroxide within the water was enhanced by increasing the plasma treatment time and the energy dose. Numerical simulations of the nanosecond-pulsed discharge were performed by using a self-consistent coupling of state-to-state kinetics of the air mixture with the Boltzmann equation of free electron kinetics. Temporal evolution of the electron energy distribution function shows departure from the Maxwellian distribution especially during the afterglow phase of the discharge. When

  15. Varietal characterization of hop (Humulus lupulus L.) by GC-MS analysis of hop cone extracts.

    PubMed

    Shellie, Robert A; Poynter, Samuel D H; Li, Jianfeng; Gathercole, Jessica L; Whittock, Simon P; Koutoulis, Anthony

    2009-11-01

    An approach is described for use in the varietal characterization of hop (Humulus lupulus L.) varieties. The study focuses on commercial hop varieties and was timed to coincide with the 2008 commercial hop harvest in Tasmania, Australia. Analysis of hop extracts was performed using GC-MS. A 60 m capillary column was employed to increase efficiency to permit the use of a quadrupole mass spectrometer in place of a time of flight mass spectrometer that is more commonly used for this type of analysis. A set of characterization functions were derived from discriminant analysis which were highly suitable for varietal characterization of the eight commercial varieties included in the study, namely Willamette, Victoria, Pride of Ringwood, Cascade, Southern Hallertau, Millennium, Southern Saaz, and Super Pride.

  16. Synthesis and alkylation activity of a nitrogen mustard agent to penetrate the blood-brain barrier.

    PubMed

    Bartzatt, Ronald L

    2004-01-01

    Nitrogen mustard agents are widely used for the clinical treatment of cancers. A nitrogen mustard (N-mustard) agent was synthesized utilizing nicotinic acid as the carrier of the alkylating substituent (-OCH2CH2N(CH2CH2Cl)2) that forms an ester group (R-C(O)-OR) on a heterocyclic ring. The N-mustard agent is a solid at room temperature and is stable for more than 6 weeks when stored at -10 degrees C. To determine the kinetics of alkylation activity a nucleophilic primary amine compound (4-chloroaniline) was placed in aqueous solution with the mustard agent at physiological pH 7.4 (pH of blood) and 37 degrees C. The alkylation reaction was found to be second-order with rate equation: rate = k2[N-mustard][Nu], where Nu = nucleophile and k2 = 0.0415 L/(mol x min). Pharmacological descriptors calculated showed values indicating a strong potential of penetrating the blood-brain barrier. The partition coefficient (Log P) of the mustard agent is 1.95 compared with 0.58 for nicotinic acid. Values of descriptors such as dipole, polar surface area, Log BB, molar refractivity, parachor, and violations of Rule of 5 were found to be 5.057 Debye, 42.44 A2, 0.662, 72.7 cm3, 607.7 cm3, and 0.0 for the N-mustard agent. Value of polar surface area for the mustard agent (42.44 A2) predicts that >90% of any amount present in the intestinal tract will be absorbed.

  17. Association of Quadriceps Strength and Psychosocial Factors With Single-Leg Hop Performance in Patients With Meniscectomy

    PubMed Central

    Hsu, Chao-Jung; George, Steven Z.; Chmielewski, Terese L.

    2016-01-01

    Background: Clinicians use the single-leg hop test to assess readiness for return to sports after knee injury. Few studies have reported the results of single-leg hop testing after meniscectomy. Additionally, the contributions of impairments in quadriceps strength and psychosocial factors to single-leg hop performance are unknown. Purpose: To compare single-leg hop performance (distance and landing mechanics) between limbs and to examine the association of single-leg hop performance with quadriceps strength and psychosocial factors in patients with meniscectomy. Study Design: Descriptive laboratory study. Methods: A total of 22 subjects who underwent meniscectomy for traumatic meniscal tears received either standard rehabilitation alone or with additional quadriceps strengthening. Testing was conducted immediately postrehabilitation and at 1 year postsurgery. A single-leg hop test was performed bilaterally, and hop distance was used to create a hop symmetry index. Landing mechanics (peak knee flexion angle, knee extension moment, and peak vertical ground-reaction force) were analyzed with a motion-capture system and a force plate. An isokinetic dynamometer (60 deg/s) assessed knee extensor peak torque and rate of torque development (RTD0-200ms and RTD0–peak torque). Questionnaires assessed fear of reinjury (Tampa Scale for Kinesiophobia [TSK-11]) and self-efficacy (Knee Activity Self-Efficacy [KASE]). Results: Rehabilitation groups did not significantly differ in single-leg hop performance; therefore, groups were combined for further analyses. The mean hop symmetry index was 88.6% and 98.9% at postrehabilitation and 1 year postsurgery, respectively. Compared with the nonsurgical limb, the surgical limb showed decreased peak knee flexion angle at postrehabilitation and decreased knee extension moment at 1 year postsurgery. The hop symmetry index was positively associated with peak torque, RTD0-200ms, and the KASE score at postrehabilitation. Moreover, at

  18. Injury incidence in hip hop dance.

    PubMed

    Ojofeitimi, S; Bronner, S; Woo, H

    2012-06-01

    Hip hop dance has rapidly become a popular international art form. There is limited information on injury patterns in this population. The purpose of this study was to determine injury incidence and patterns among three groups of hip hop dancers. Three hundred and twelve intermediate, advanced, and expert hip hop dancers were recruited at battles, dance conferences, clubs, and on dance related web sites within the United States and internationally. A Web-based survey was conducted over a 6-month period. Inclusion criteria included intermediate and advanced level dancers over the age of 13. Dancers were divided into three main categories: Breakers, Popper/Lockers, and New Schoolers. Separate analysis of variances were used to compare injury pattern differences between groups. Two hundred and thirty-two dancers reported a total of 738 injuries. Five hundred and six of these (sustained by 205 dancers) were time-loss (TL) injuries. Annual injury incidence was 237% (162% involving TL). Lower extremity injuries were 52% and upper extremity injuries 32% of total injuries. Breakers had a higher injury incidence compared with Popper/Lockers, and New Schoolers. Hip hop dancers report injury rates that are higher than other dance forms but similar to gymnastics. These dancers should be educated concerning injury prevention, biomechanics, and use of protective equipment.

  19. Multimodal Hip Hop Productions as Media Literacies

    ERIC Educational Resources Information Center

    Turner, K. C. Nat

    2012-01-01

    This study draws on ethnographic data from a year-long multimodal media production (MMP) course and the experience of an African American female adolescent who used the production of multimodal Hip Hop texts to express her creativity and growing socially conscious view of the world. The study demonstrates how students made meaning multimodally and…

  20. The Philippine "Hip Hop Stick Dance"

    ERIC Educational Resources Information Center

    Lewis, Lisa

    2012-01-01

    This article introduces a dance that blends the traditional cultural heritage of the Philippines with modern music and moves. "Hip Hop Stick Dance" incorporates Tinikling (the Philippine national dance) and Arnis (a Filipino style of martial arts) to create a contemporary combination of rhythm, dance, and fitness. It was designed to introduce…

  1. Forecasting and management of hop downy mildew

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Downy mildew of hop, caused by Pseudoperonospora humuli, is managed in the Pacific Northwestern U.S. by regular application of fungicides. A degree-day model that forecasts the first emergence of shoots systemically infection with P. humuli (termed basal spikes) and a risk index for secondary sprea...

  2. The Rap on Hip-Hop

    ERIC Educational Resources Information Center

    Piekarski, Bill

    2004-01-01

    From its humble origins some 30 years ago in New York's bombed-out, poverty-ravaged South Bronx, hip-hop has risen to become a dominant cultural force both here and abroad. Strictly defined, the term refers to the entire cultural constellation that accompanies rap music, which in 2001 surpassed country music as the most popular musical genre in…

  3. Communication: Fully coherent quantum state hopping

    SciTech Connect

    Martens, Craig C.

    2015-10-14

    In this paper, we describe a new and fully coherent stochastic surface hopping method for simulating mixed quantum-classical systems. We illustrate the approach on the simple but unforgiving problem of quantum evolution of a two-state quantum system in the limit of unperturbed pure state dynamics and for dissipative evolution in the presence of both stationary and nonstationary random environments. We formulate our approach in the Liouville representation and describe the density matrix elements by ensembles of trajectories. Population dynamics are represented by stochastic surface hops for trajectories representing diagonal density matrix elements. These are combined with an unconventional coherent stochastic hopping algorithm for trajectories representing off-diagonal quantum coherences. The latter generalizes the binary (0,1) “probability” of a trajectory to be associated with a given state to allow integers that can be negative or greater than unity in magnitude. Unlike existing surface hopping methods, the dynamics of the ensembles are fully entangled, correctly capturing the coherent and nonlocal structure of quantum mechanics.

  4. Sampling Memories: Using Hip-Hop Aesthetics to Learn from Urban Schooling Experiences

    ERIC Educational Resources Information Center

    Petchauer, Emery

    2012-01-01

    This article theorizes and charts the implementation of a learning activity designed from the hip-hop aesthetic of sampling. The purpose of this learning activity was to enable recent urban school graduates to reflect upon their previous schooling experiences as a platform for future learning in higher education. This article illustrates what…

  5. A comparison of professional-level faculty and student perceptions of active learning: its current use, effectiveness, and barriers

    PubMed Central

    Metz, Michael J.

    2014-01-01

    Active learning is an instructional method in which students become engaged participants in the classroom through the use of in-class written exercises, games, problem sets, audience-response systems, debates, class discussions, etc. Despite evidence supporting the effectiveness of active learning strategies, minimal adoption of the technique has occurred in many professional programs. The goal of this study was to compare the perceptions of active learning between students who were exposed to active learning in the classroom (n = 116) and professional-level physiology faculty members (n = 9). Faculty members reported a heavy reliance on lectures and minimal use of educational games and activities, whereas students indicated that they learned best via the activities. A majority of faculty members (89%) had observed active learning in the classroom and predicted favorable effects of the method on student performance and motivation. The main reported barriers by faculty members to the adoption of active learning were a lack of necessary class time, a high comfort level with traditional lectures, and insufficient time to develop materials. Students hypothesized similar obstacles for faculty members but also associated many negative qualities with the traditional lecturers. Despite these barriers, a majority of faculty members (78%) were interested in learning more about the alternative teaching strategy. Both faculty members and students indicated that active learning should occupy portions (29% vs. 40%) of face-to-face class time. PMID:25179615

  6. Inhibition of human cytochrome P450 enzymes by hops (Humulus lupulus) and hop prenylphenols

    PubMed Central

    Nikolić, Dejan; Chen, Shao-Nong; Huang, Ke; Li, Guannan; Pauli, Guido F.; van Breemen, Richard B.

    2014-01-01

    As hops (Humulus lupulus L.) are used in the brewing of beer and by menopausal women as estrogenic dietary supplements, the potential for hop extracts and hop constituents to cause drug-botanical interactions by inhibiting human cytochrome P450 enzymes was investigated. Inhibition of major human cytochrome P450 enzymes by a standardized hop extract and isolated hop prenylated phenols was evaluated using a fast and efficient assay based on ultrahigh pressure liquid chromatography-tandem mass spectrometry. The hop extract at 5 μg/mL inhibited CYP2C8 (93%), CYP2C9 (88%), CYP2C19 (70%), and CYP1A2 (27%) with IC50 values of 0.8, 0.9, 3.3, and 9.4 μg/mL, respectively, but time-dependent inactivation was observed only for CYP1A2. Isoxanthohumol from hops was the most potent inhibitor of CYP2C8 with an IC50 of 0.2 μM, whereas 8-prenylnaringenin was the most potent inhibitor of CYP1A2, CYP2C9 and CYP2C19 with IC50 values of 1.1 μM, 1.1 μM and 0.4 μM, respectively. Extracts of hops contain prenylated compounds such as the flavanones isoxanthohumol and 8-prenylnaringenin and the chalcone xanthohumol that can inhibit CYP450s, especially the CYP2C family, which may affect the efficacy and safety of some CYP2C substrate drugs when co-administered. PMID:24342125

  7. Inhibition of human cytochrome P450 enzymes by hops (Humulus lupulus) and hop prenylphenols.

    PubMed

    Yuan, Yang; Qiu, Xi; Nikolić, Dejan; Chen, Shao-Nong; Huang, Ke; Li, Guannan; Pauli, Guido F; van Breemen, Richard B

    2014-03-12

    As hops (Humulus lupulus L.) are used in the brewing of beer and by menopausal women as estrogenic dietary supplements, the potential for hop extracts and hop constituents to cause drug-botanical interactions by inhibiting human cytochrome P450 enzymes was investigated. Inhibition of major human cytochrome P450 enzymes by a standardized hop extract and isolated hop prenylated phenols was evaluated using a fast and efficient assay based on ultrahigh pressure liquid chromatography-tandem mass spectrometry. The hop extract at 5 μg/mL inhibited CYP2C8 (93%), CYP2C9 (88%), CYP2C19 (70%), and CYP1A2 (27%) with IC50 values of 0.8, 0.9, 3.3, and 9.4 μg/mL, respectively, but time-dependent inactivation was observed only for CYP1A2. Isoxanthohumol from hops was the most potent inhibitor of CYP2C8 with an IC50 of 0.2 μM, whereas 8-prenylnaringenin was the most potent inhibitor of CYP1A2, CYP2C9 and CYP2C19 with IC50 values of 1.1 μM, 1.1 μM and 0.4 μM, respectively. Extracts of hops contain prenylated compounds such as the flavanones isoxanthohumol and 8-prenylnaringenin and the chalcone xanthohumol that can inhibit CYP450s, especially the CYP2C family, which may affect the efficacy and safety of some CYP2C substrate drugs when co-administered.

  8. Featherless Dinosaurs and the Hip-Hop Simulacrum: Reconsidering Hip-Hop's Appropriateness for the Music Classroom

    ERIC Educational Resources Information Center

    Kruse, Adam J.

    2016-01-01

    This article offers considerations for music teachers interested in including hip-hop music in their classrooms but who might feel concerned with or overwhelmed by issues of appropriateness. Two concerns related to hip-hop music are examined: language and negative social themes. Commercial interests in hip-hop music have created a simulacrum (or…

  9. NASA GSFC Science Communication Working Group: Addressing Barriers to Scientist and Engineer Participation in Education and Public Outreach Activities

    NASA Astrophysics Data System (ADS)

    Bleacher, L.; Hsu, B. C.; Campbell, B. A.; Hess, M.

    2011-12-01

    The Science Communication Working Group (SCWG) at NASA Goddard Space Flight Center (GSFC) has been in existence since late 2007. The SCWG is comprised of education and public outreach (E/PO) professionals, public affairs specialists, scientists, and engineers. The goals of the SCWG are to identify barriers to scientist and engineer engagement in E/PO activities and to enable those scientists and engineers who wish to contribute to E/PO to be able to do so. SCWG members have held meetings with scientists and engineers across GSFC to determine barriers to their involvement in E/PO. During these meetings, SCWG members presented examples of successful, ongoing E/PO projects, encouraged active research scientists and engineers to talk about their own E/PO efforts and what worked for them, discussed the E/PO working environment, discussed opportunities for getting involved in E/PO (particularly in high-impact efforts that do not take much time), handed out booklets on effective E/PO, and asked scientists and engineers what they need to engage in E/PO. The identified barriers were consistent among scientists in GSFC's four science divisions (Earth science, planetary science, heliophysics, and astrophysics). Common barriers included 1) lack of time, 2) lack of funding support, 3) lack of value placed on doing E/PO by supervisors, 4) lack of training on doing appropriate/effective E/PO for different audiences, 5) lack of awareness and information about opportunities, 6) lack of understanding of what E/PO really is, and 7) level of effort required to do E/PO. Engineers reported similar issues, but the issues of time and funding support were more pronounced due to their highly structured work day and environment. Since the barriers were identified, the SCWG has taken a number of steps to address and rectify them. Steps have included holding various events to introduce scientists and engineers to E/PO staff and opportunities including an E/PO Open House, brown bag seminars on

  10. Barriers to Screening and Possibilities for Active Detection of Family Medicine Attendees Exposed to Intimate Partner Violence

    PubMed Central

    KOPČAVAR GUČEK, Nena; PETEK, Davorina; ŠVAB, Igor; SELIČ, Polona

    2016-01-01

    Introduction In 1996 the World Health Organization declared intimate partner violence (IPV) the most important public health problem. Meta-analyses in 2013 showed every third female globally had been a victim of violence. Experts find screening controversial; family medicine is the preferred environment for identifying victims of violence, but barriers on both sides prevent patients from discussing it with doctors. Methods In July 2014, a qualitative study was performed through semi-structured interviews with ten family doctors of different ages and gender, working in rural or urban environments. Sound recordings of the interviews were transcribed, and the record verified. The data were interpreted using content analysis. A coding scheme was developed and later verified and analysed by two independent researchers. The text of the interviews was analysed according to the coding scheme. Results Two coding schemes were developed: one for screening, and the other for the active detection of IPV. The main themes emerging as barriers to screening were lack of time, staff turnover, inadequate finance, ignorance of a clear definition, poor commitment to screening, obligatory follow-up, risk of deterioration of the doctor-patient relationship, and insincerity on the part of the patient. Additionally, cultural aspects of violence, uncertainty/ helplessness, fear, lack of competence and qualifications, autonomy/negative experience, and passive role/stigma/ fear on the part of the patients were barriers to active detection. Conclusion All the participating doctors had had previous experience with active detection of IPV and were aware of its importance. Due to several barriers to screening for violence they preferred active detection. PMID:27647084

  11. Effects of hop extracts on nasal rubbing and sneezing in BALB/c mice.

    PubMed

    Takubo, Miho; Inoue, Toshio; Jiang, Shuishi; Tsumuro, Tae; Ueda, Yuhki; Yatsuzuka, Rie; Segawa, Shuichi; Watari, Junji; Kamei, Chiaki

    2006-04-01

    The effects of hop extracts (Humulus lupulus L.) on histamine release from rat peritoneal mast cells and human basophilic KU812 cells were studied. Hop water extract (HWE) and XAD-4 50% methanol fraction of HWE (MFH) inhibited histamine release from rat mast cells induced by compound 48/80 at concentrations of 100 and 10 mug/ml, respectively. Almost the same findings were observed with A23187-induced histamine release from KU812 cells. Next, we studied the effects of hop extracts on antigen-induced nasal rubbing and sneezing in sensitized BALB/c mice. HWE caused a significant inhibition of nasal rubbing and sneezing at a dose of 500 mg/kg. MFH also inhibited nasal rubbing and sneezing dose-dependently. A significant difference was observed from 100 mg/kg in nasal rubbing and 200 mg/kg in sneezing. The effects of both extracts became clear after repeated administration. HWE and MFH significantly inhibited both nasal rubbing and sneezing, respectively, after consecutive treatment for 15 d at smaller doses compared with single administration. This finding indicates that the active component of hop is included in MFH, which was absorbed to Amberlite XAD-4 and eluted with 50% methanol. These results clearly demonstrated that hop extracts may be effective in the relief of symptoms of allergic rhinitis.

  12. A three-step kinetic model for electrochemical charge transfer in the hopping regime.

    PubMed

    Yin, Xing; Wierzbinski, Emil; Lu, Hao; Bezer, Silvia; de Leon, Arnie R; Davis, Kathryn L; Achim, Catalina; Waldeck, David H

    2014-09-04

    Single-step nonadiabatic electron tunneling models are widely used to analyze electrochemical rates through self-assembled monolayer films (SAMs). For some systems, such as nucleic acids, long-range charge transfer can occur in a "hopping" regime that involves multiple charge transfer events and intermediate states. This report describes a three-step kinetic scheme to model charge transfer in this regime. Some of the features of the three-step model are probed experimentally by changing the chemical composition of the SAM. This work uses the three-step model and a temperature dependence of the charge transfer rate to extract the charge injection barrier for a SAM composed of a 10-mer peptide nucleic acid that operates in the hopping regime.

  13. Selected parameters of immunological response in hop growers during the period of intensive application of pesticides.

    PubMed

    Tokarska-Rodak, Małgorzata; Toś-Luty, Sabina; Haratym-Maj, Agnieszka

    2004-01-01

    The aim of the study was determination of selected parameters of immunological response among hop growers and farmers in conditions of intensive exposure to means of plant protection. Survey data was collected from 238 males aged 25-70 living in the area of Wilków near Puławy (Lublin Region). Control group were males from the area of Witoszyn (Lublin Region)--53 people aged 25-70 occupied mainly with land cultivation. Based on an environmental survey conducted among hop growers and farmers, the respondents were divided into 3 age groups: 25-40, 41-55 and 56-70. Laboratory tests covered the determination of selected morphological parameters, phagocytic test, NBT test, and myeloperoxidasis (MPO) concentration in blood serum of hop growers and farmers.A significant decrease was noted in the number of platelets in the general population of hop growers and in individual age groups, compared to the control groups of farmers. Analysis of individual sub-populations of leukocytes showed a significantly higher number statistically of basophils and lymphocytes among hop growers, compared to farmers. A detailed analysis of the degree of phagocytic and bactericidal activity of neutrophils allowed us to presume that during the period of spraying there occurred a mobilisation of the granulocytic system, manifested by the presence of over 90% of neutrophils of intensified phagocytic activity, and 20% of neutrophils of intensified bactericidal activity. The preparations prepared by the routine NBT test method were analysed with the use of LUCIA computer programme (version 4.51). The analysis of the level of MPO in blood serum in the populations examined showed the presence of statistically significant differences. In hop growers, the MPO level was significantly higher statistically (60.0 ng/ml), compared to the control group of farmers (43.4 ng/ml).

  14. Phase diagram of hopping conduction mechanisms in polymer nanofiber network

    SciTech Connect

    Li, Jeng-Ting; Lu, Yu-Cheng; Jiang, Shiau-Bin; Zhong, Yuan-Liang; Yeh, Jui-Ming

    2015-12-07

    Network formation by nanofiber crosslinking is usually in polymer materials as application in organic semiconductor devices. Electron hopping transport mechanisms depend on polymer morphology in network. Conducting polymers morphology in a random network structure is modeled by a quasi-one-dimensional system coupled of chains or fibers. We observe the varying hopping conduction mechanisms in the polyaniline nanofibers of the random network structure. The average diameter d of the nanofibers is varied from approximately 10 to 100 nm. The different dominant hopping mechanisms including Efros-Shklovskii variable-range hopping (VRH), Mott VRH, and nearest-neighbor hopping are dependent on temperature range and d in crossover changes. The result of this study is first presented in a phase diagram of hopping conduction mechanisms based on the theories of the random network model. The hopping conduction mechanism is unlike in normal semiconductor materials.

  15. Electronic Nature of Step-edge Barriers Against Adatom Descent on Transition-metal Surfaces

    SciTech Connect

    Mo, Yina; Zhu, Wenguang; Kaxiras, Efthimios; Zhang, Zhenyu

    2008-01-01

    The activation barriers against adatom migration on terraces and across steps play an essential role in determining the growth morphology of surfaces, interfaces, and thin lms. By studying a series of adatoms on representative transition metal surfaces through extensive rst-principles calculations, we establish a clear correlation between the preferred mechanism and activation energy for adatom descent at a step and the relative degree of electronic shell lling between the adatom and the substrate. We also nd an approximate linear relation between the adatom hopping barriers at step edges and the adatom-surface bonding strength. These results may serve as simple guiding rules for predicting the precise atomic nature of surface morphologies in heteroepitaxial growth such as nanowires.

  16. Cryptococcus neoformans phospholipase B1 activates host cell Rac1 for traversal across the blood-brain barrier.

    PubMed

    Maruvada, Ravi; Zhu, Longkun; Pearce, Donna; Zheng, Yi; Perfect, John; Kwon-Chung, Kyung J; Kim, Kwang Sik

    2012-10-01

    Cryptococcus neoformans penetration into the central nervous system (CNS) requires traversal of the blood-brain barrier that is composed of a single layer of human brain microvascular endothelial cells (HBMEC), but the underlying mechanisms of C. neoformans traversal remain incompletely understood. C. neoformans transcytosis of HBMEC monolayer involves rearrangements of the host cell actin cytoskeleton and small GTP-binding Rho family proteins such as Rac1 are shown to regulate host cell actin cytoskeleton. We, therefore, examined whether C. neoformans traversal of the blood-brain barrier involves host Rac1. While the levels of activated Rac1 (GTP-Rac1) in HBMEC increased significantly upon incubation with C. neoformans strains, pharmacological inhibition and down-modulation of Rac1 significantly decreased C. neoformans transcytosis of HBMEC monolayer. Also, Rac1 inhibition was efficient in preventing C. neoformans penetration into the brain. In addition, C. neoformans phospholipase B1 (Plb1) was shown to contribute to activating host cell Rac1, andSTAT3 was observed to associate with GTP-Rac1 in HBMEC that were incubated with C. neoformans strain but not with its Δplb1 mutant. These findings demonstrate for the first time that C. neoformans Plb1 aids fungal traversal across the blood-brain barrier by activating host cell Rac1 and its association with STAT3, and suggest that pharmacological intervention of host-microbial interaction contributing to traversal of the blood-brain barrier may prevent C. neoformans penetration into the brain.

  17. Cichorium intybus root extract: A "vitamin D-like" active ingredient to improve skin barrier function.

    PubMed

    Maia Campos, P M B G; G Mercurio, D; O Melo, M; Closs-Gonthier, B

    2017-02-01

    During the aging process, the human skin suffers many alterations including dryness, skin barrier function damage. The skin barrier function is important to the prevention of skin alterations and maintenance of homeostasis. So, the objective of this study was to assess the clinical efficacy on skin barrier function of Cichorium intybus root extract in cosmetic formulations with or without UV filters. Fifty women, aged between 45 and 60 years, were divided into two groups. One group received vehicle formulations containing UV filters, and the other group received formulations without UV filters. Both groups received a formulation containing the extract and the vehicle. The formulations were applied twice daily to the upper arms after washing with sodium lauryl sulphate. Transepidermal water loss (TEWL) and skin microrelief were evaluated before and after a 14- and 28-day period of treatment. The control regions and regions where the vehicles were applied showed an increase in the TEWL. For the formulations containing the extract, decreased TEWL and improved microrelief were observed when compared to the vehicle and control areas after a 28-day period. In conclusion, Cichorium intybus root extract showed protective and restructuring effects on the skin and stands out as an innovative ingredient to improve skin barrier function.

  18. Noise annoyance and activity disturbance before and after the erection of a roadside noise barrier.

    PubMed

    Nilsson, Mats E; Berglund, Birgitta

    2006-04-01

    Questionnaire studies were conducted in a residential area before and after the erection of a 2.25 m high noise barrier of conventional type along a heavily traveled road (19,600 vehicles/24 h). The interval between studies was two years. Houses closest to the barrier received a sound-level reduction from -70.0 to 62.5 dB Lden at the most exposed facade. The sound-level reduction decreased with distance to the road, and was negligible for houses at more than 100 m distance. Up to this distance, the noise barrier reduced residents' noise annoyance outdoors and indoors as well as improved speech communication outdoors. Indoors, speech communication and sleep disturbance were slightly but nonsignificantly improved. Predictions of the number of annoyed persons from published exposure-response curves (in Lden) agreed with the percentage of residents being annoyed when indoors, before and after the barrier. Conversely, the percentage of residents being annoyed when outdoors clearly exceeded the predictions. These results suggest that these exposure-response curves may be used in predicting indoor situations, but they should not be applied in situations where outdoor annoyance is at focus.

  19. Barriers to Application of E-Learning in Training Activities of SMEs

    ERIC Educational Resources Information Center

    Anderson, Randy J.; Wielicki, Tomasz; Anderson, Lydia E.

    2010-01-01

    This paper reports on the on-going study of Small and Mid-Size Enterprises (SMEs) in the Central California concerning their use of Information and Communication Technology (ICT). This research project analyzed data from a sample of 161 SMEs. Specifically, this part of the study is investigating the major barriers to applications of e-learning…

  20. The prevalence of barriers for Colombian college students engaging in physical activity.

    PubMed

    Ramírez-Vélez, Robinson; Tordecilla-Sanders, Alejandra; Laverde, David; Hernández-Novoa, Juan Gilberto; Ríos, Marcelo; Rubio, Fernando; Correa-Bautista, Jorge Enrique; Martinez-Torres, Javier

    2014-09-18

    Objetivo: El objetivo de este trabajo fue analizar la prevalencia de barreras y su asociación con la práctica de AF en universitarios de Colombia. Métodos: Estudio descriptivo de corte transversal, en 5.663 sujetos (3.348 hombres), de tres ciudades de Colombia. Las razones que podrían impedir realizar AF, se evaluaron con el cuestionario de “Percepción de barreras para la práctica de la actividad física” (en inglés, Barriers to Being Active Quiz-21 ítems). Un análisis de regresión logística para cada barrera ajustado por las variables de confusión (sexo, edad e IMC) fue usado para verificar la asociación. Resultados: En la población general, el “miedo a lastimarse” (89,5%) y la “falta de habilidades” (82,1%) eran, en este orden, las razones más frecuentes como barreras auto-percibidas de la práctica de AF. El grupo de mujeres mostró una asociación protectora en relación con las barreras “falta de tiempo” (OR = 0,53 IC95% 0,47-0,60), “influencia social” (OR = 0,67 IC95% 0,60-0,75), “falta de energía” (OR = 0,54 IC95% 0,49-0,61), “falta de voluntad” (OR = 0,57 IC95% 0,51-0,64), “falta de habilidades” (OR = 0,76 IC95% 0,66-0,87) y “falta de recursos” (OR = 0,79 IC95% 0,71-0,89). Esta observación también aparece en el grupo de edades comprendidas entre los 20 y 23 años en la barrera “influencia social” (OR = 0,83 IC95% 0,74-0,94), y en los mayores a 23 años (OR = 0,86 IC95% 0,74-0,99) en la barrera “falta de energía”. Conclusión: Se encontró una importante prevalencia en la percepción de las barreras para cesar la práctica de AF. Estos resultados pueden servir de referencia para las acciones específicas para promover la AF y la salud en universitarios de Colombia.

  1. Effects of xanthohumol-rich hop extract on the differentiation of preadipocytes.

    PubMed

    Kiyofuji, Ayane; Yui, Kazuki; Takahashi, Koki; Osada, Kyoichi

    2014-01-01

    Xanthohumol is a major prenylated, hydrophobic flavonoid found in the female inflorescences of the hop plant (Humulus lupulus L.). In this study, we examined the effects of xanthohumol-rich hop extract containing 17.8% xanthohumol and 12.4% isoxanthohumol on the differentiation and adipogenesis of 3T3L1 cells. We observed that the extract inhibited the differentiation of 3T3L1 cells and intracellular fat droplets via the regulation of adipogenic factors such as the peroxisome proliferator-activated receptor gamma, CCAAT/enhancer binding protein alpha, and adipocyte fatty acid-binding protein.

  2. Hopping charge transport in molecularly doped polymers: Polymer matrix dependence of the hole drift mobility

    NASA Astrophysics Data System (ADS)

    Kanemitsu, Yoshihiko

    1992-03-01

    Effects of the polymer matrix on the drift mobility of holes in polymers doped with 2-(p-dipropylaminophenyl)-4-(p-dimethylaminophenyl)-5-(o-chlorophenyl)-1, 3-oxazole were studied by means of time-of-flight photoconductivity measurements. The drift mobility at zero field, the activation energy for hopping, and the electric field dependence of the mobility strongly depend on the polymer composition. These polymer matrix dependence of the drift mobility are largely related to energetic disorder of hopping sites in binary solid solution.

  3. Historical changes in the Mississippi-Alabama barrier islands and the roles of extreme storms, sea level, and human activities

    USGS Publications Warehouse

    Morton, Robert A.

    2007-01-01

    westward sediment transport by alongshore currents, and Cat Island is being reshaped as it adjusts to post-formation changes in wave and current patterns associated with deposition of the St. Bernard lobe of the Mississippi delta. The principal causes of barrier island land loss are frequent intense storms, a relative rise in sea level, and a deficit in the sediment budget. The only factor that has a historical trend that coincides with the progressive increase in rates of land loss is the progressive reduction in sand supply associated with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. Neither rates of relative sea level rise nor storm parameters have long-term historical rends that match the increased rates of land loss since the mid 1800s. The historical rates of relative sea level rise in the northern Gulf of Mexico have been relatively constant and storm frequencies and intensities occur in multidecal cycles. However, the most recent land loss accelerations likely related to the increased storm activity since 1995. Considering the predicted trends for storms and sea level related to global warming, it is clear that the barrier islands will continue to lose land area at a rapid rate without a reversal in trend of at least one of the causal factors. The reduction in sand supply related to disruption of the alongshore sediment transport system is the only factor contributing to land loss that can be managed directly. This can be accomplished by placing dredged material so that the adjacent barrier island shores revive it for island nourishment and rebuilding.

  4. Direct measurement of the dynamics of hole hopping in extended DNA G-tracts. An unbiased random walk.

    PubMed

    Conron, Sarah M Mickley; Thazhathveetil, Arun K; Wasielewski, Michael R; Burin, Alexander L; Lewis, Frederick D

    2010-10-20

    We report the measurement of distance- and temperature-dependent rate constants for charge separation in capped hairpins in which a stilbene hole acceptor and hole donor are separated by A(3)G(n) diblock polypurine sequences consisting of 3 adenines and 1-19 guanines. The longer diblock systems obey the simplest model for an unbiased random walk, providing a direct measurement of k(hop) = 4.3 × 10(9) s(-1) for a single reversible G-to-G hole hopping step, somewhat faster than the value of 1.2 × 10(9) s(-1) calculated for A-tract hole hopping. The temperature dependence for hopping in A(3)G(13) provides values of E(act) = 2.8 kcal/mol and A = 7 × 10(9) s(-1), consistent with a weakly activated, conformationally gated process.

  5. Targeted analysis of polyphenol metabolism during development of hop (Humulus lupulus L.) cones following treatment with prohexadione-calcium.

    PubMed

    Kavalier, Adam R; Ma, Chunhui; Figueroa, Mario; Kincaid, Dwight; Matthews, Paul D; Kennelly, Edward J

    2014-02-15

    Hops (Humulus lupulus), a main ingredient in beer, are valued as a source of bitter flavour and biologically active polyphenols. We treated immature hop cones with prohexadione-calcium (Pro-Ca), a flavanone-3-hydroxylase (F3H) inhibitor, to perturb the flavonoid pathway, and conducted a targeted analysis of 29 compounds from the phenolic acid, flavonoid, and terpenophenolic pathways, using photodiode array (UHPLC-PDA), and time of flight mass spectrometry (LC-TOF-MS) analysis. Hop cones were analysed over four stages of development spanning 22days following Pro-Ca treatment. The content of terpenophenolics as well as metabolic precursors upstream from F3H significantly increased, and levels of flavonoid products downstream from F3H decreased. The methods developed here serve to compliment flavour analysis of polyphenol rich foods, and our results suggest ways to improve upon traditional agricultural methods to produce hops with altered chemical profiles.

  6. Analysis of pesticide residues in hops and their extraction by liquid CO2 during the production of hop extracts.

    PubMed

    Williams, C S; Eastoe, B V; Slaiding, I R; Walker, M D

    1994-01-01

    A method has been developed for analysing pesticide residues in whole hops, hop pellets and hop extracts by GC-MS. Five batches of hop pellets containing nine different pesticides (triadimefon, dicofol, mephosfolan, bupirimate, cyhalothrin, tetradifon, endosulfan, pyrazophos and total bisdithiocarbamates) were extracted with liquid CO2. Pesticide concentrations in the original hop pellets and the extracts were determined. The pesticides were concentrated by the extraction process (concentration factor 1.3-8.3), except for the bisdithiocarbamates, which were not extracted. When the same amount of bitterness was added into the brewing process using liquid CO2 extract as opposed to hop pellets, for most of the pesticides proportionately less pesticide was added. However, for two pesticides (dicofol and triadimefon) corrected residue levels were similar to, or in some cases slightly higher than, those in hop pellets.

  7. Long-term oral administration of hop flower extracts mitigates Alzheimer phenotypes in mice.

    PubMed

    Sasaoka, Norio; Sakamoto, Megumi; Kanemori, Shoko; Kan, Michiru; Tsukano, Chihiro; Takemoto, Yoshiji; Kakizuka, Akira

    2014-01-01

    Coincident with the expanding population of aged people, the incidence of Alzheimer disease (AD) is rapidly increasing in most advanced countries. At present, no effective prophylactics are available. Among several pathological mechanisms proposed for AD, the "amyloid hypothesis" has been most widely accepted, in which accumulation or deposition of Aβ is considered to be the initial event. Thus, prevention of Aβ production would be an ideal strategy for the treatment or prevention of AD. Aβ is produced via the proteolytic cleavage of its precursor protein, APP (amyloid precursor protein), by two different enzymes, β and γ-secretases. Indeed, inhibitors against either or both enzymes have been developed and tested for clinical efficacy. Based on the "amyloid hypothesis", we developed a luciferase-based screening method to monitor γ-secretase activity, screened more than 1,600 plant extracts, most of which have long been used in Chinese medicine, and observed that Hop extracts significantly inhibit Aβ production in cultured cells. A major component of the inhibitory activity was purified, and its chemical identity was determined by NMR to be Garcinielliptone HC. In vivo, oral administration of Hop extracts to AD model mice decreased Aβ depositions in the cerebral cortex of the parietal lobe, hippocampus, and artery walls (amyloid angiopathy) in the brains. In a Morris water maze test, AD model mice that had daily consumed Hop extracts in their drinking water showed significant mitigation of memory impairment at ages of 9 and 12 months. Moreover, in the open field test oral administration of Hop extracts also prevented an emotional disturbance that appeared in the AD mice at 18 months. Despite lifelong consumption of Hop extracts, no deleterious side effects were observed at any age. These results support the "amyloid hypothesis", and indicate that Hop extract is a promising candidate for an effective prophylactic for AD.

  8. Long-Term Oral Administration of Hop Flower Extracts Mitigates Alzheimer Phenotypes in Mice

    PubMed Central

    Sasaoka, Norio; Sakamoto, Megumi; Kanemori, Shoko; Kan, Michiru; Tsukano, Chihiro; Takemoto, Yoshiji; Kakizuka, Akira

    2014-01-01

    Coincident with the expanding population of aged people, the incidence of Alzheimer disease (AD) is rapidly increasing in most advanced countries. At present, no effective prophylactics are available. Among several pathological mechanisms proposed for AD, the “amyloid hypothesis” has been most widely accepted, in which accumulation or deposition of Aβ is considered to be the initial event. Thus, prevention of Aβ production would be an ideal strategy for the treatment or prevention of AD. Aβ is produced via the proteolytic cleavage of its precursor protein, APP (amyloid precursor protein), by two different enzymes, β and γ-secretases. Indeed, inhibitors against either or both enzymes have been developed and tested for clinical efficacy. Based on the “amyloid hypothesis”, we developed a luciferase-based screening method to monitor γ-secretase activity, screened more than 1,600 plant extracts, most of which have long been used in Chinese medicine, and observed that Hop extracts significantly inhibit Aβ production in cultured cells. A major component of the inhibitory activity was purified, and its chemical identity was determined by NMR to be Garcinielliptone HC. In vivo, oral administration of Hop extracts to AD model mice decreased Aβ depositions in the cerebral cortex of the parietal lobe, hippocampus, and artery walls (amyloid angiopathy) in the brains. In a Morris water maze test, AD model mice that had daily consumed Hop extracts in their drinking water showed significant mitigation of memory impairment at ages of 9 and 12 months. Moreover, in the open field test oral administration of Hop extracts also prevented an emotional disturbance that appeared in the AD mice at 18 months. Despite lifelong consumption of Hop extracts, no deleterious side effects were observed at any age. These results support the “amyloid hypothesis”, and indicate that Hop extract is a promising candidate for an effective prophylactic for AD. PMID:24489866

  9. "My hair or my health:" Overcoming barriers to physical activity in African American women with a focus on hairstyle-related factors.

    PubMed

    Huebschmann, Amy G; Campbell, Lucille Johnson; Brown, Candace S; Dunn, Andrea L

    2016-01-01

    Physical activity disparities among African American (AA) women may be related to sociocultural barriers, including difficulties with restyling hair after exercise. We sought to identify physical activity barriers and facilitators in AA women with a focus on sociocultural factors related to hairstyle maintenance. Participants (n = 51) were AA women aged 19-73 years who completed valid surveys and participated in structured focus groups, stratified by age and physical activity levels, from November 2012 to February 2013. The Constant Comparison method was used to develop qualitative themes for barriers and facilitators. The most frequently reported general physical activity barrier among exercisers was "lack of money" (27%) and among non-exercisers was "lack of self-discipline" (57%). A hairstyle-related barrier of "sweating out my hairstyle" was reported by 7% of exercisers and 29% of non-exercisers. This hairstyle-related barrier included the need for extra time and money to restyle hair due to perspiration. Hairstyle-related facilitators included: prioritizing health over hairstyle and high self-efficacy to restyle hair after perspiration. Participants were interested in resources to simplify hairstyle maintenance. AA women whose hairstyle is affected by perspiration may avoid physical activity due to time and financial burdens. Increasing self-efficacy to restyle hair after perspiration may help to overcome this barrier.

  10. General Practitioners’ Barriers to Prescribe Physical Activity: The Dark Side of the Cluster Effects on the Physical Activity of Their Type 2 Diabetes Patients

    PubMed Central

    Lanhers, Charlotte; Duclos, Martine; Guttmann, Aline; Coudeyre, Emmanuel; Pereira, Bruno; Ouchchane, Lemlih

    2015-01-01

    Aims/hypothesis To describe barriers to physical activity (PA) in type 2 diabetes patients and their general practitioners (GPs), looking for practitioner’s influence on PA practice of their patients. Methods We conducted a cross-sectional study on GPs (n = 48) and their type 2 diabetes patients (n = 369) measuring respectively barriers to prescribe and practice PA using a self-assessment questionnaire: barriers to physical activity in diabetes (BAPAD). Statistical analysis was performed accounting hierarchical data structure. Similar practitioner’s patients were considered a cluster sharing common patterns. Results The higher the patient’s BAPAD score, the higher the barriers to PA, the higher the risk to declare practicing no PA (p<0.001), low frequency and low duration of PA (p<0.001). A high patient’s BAPAD score was also associated with a higher risk to have HbA1c ≥7% (53 mmol/mol) (p = 0.001). The intra-class correlation coefficient between type 2 diabetes patients and GPs was 34%, indicating a high cluster effect. A high GP’s BAPAD score, regarding the PA prescription, is predictive of a high BAPAD score with their patients, regarding their practice (p = 0.03). Conclusion/interpretation Type 2 diabetes patients with lower BAPAD score, thus lower barriers to physical activity, have a higher PA level and a better glycemic control. An important and deleterious cluster effect between GPs and their patients is demonstrated: the higher the GP’s BAPAD score, the higher the type 2 diabetes patients’ BAPAD score. This important cluster effect might designate GPs as a relevant lever for future interventions regarding patient’s education towards PA and type 2 diabetes management. PMID:26468874

  11. Epigenetic changes detected in micropropagated hop plants.

    PubMed

    Peredo, Elena L; Arroyo-García, Rosa; Revilla, M Angeles

    2009-07-01

    Micropropagation is a widely used technique in hops (Humulus lupulus L.). However, to the best of our knowledge, the genetic and epigenetic stability of the microplants has never been tested before. In the present study, two hop accessions were established in vitro and micropropagated for 2 years. The genetic and epigenetic stability of the in vitro plants was analyzed with several molecular techniques: random amplified DNA polymorphism (RAPD), retrotransposon microsatellite amplified polymorphism (REMAP), and methylation-sensitive amplification polymorphism (MSAP). No genetic variation among control and treated plants was found, even after 12 cycles of micropropagation. Epigenetic variation was detected, first, when field and in vitro samples were compared. Nearly a 30% of the detected fragments presented the same pattern of alterations in all the vitroplants. Second, lower levels of epigenetic variation were detected among plants from the different subcultures. Part of this detected variation seemed to be accumulated along the 12 sequential subcultures tested.

  12. Organic magnetoresistance based on hopping theory

    NASA Astrophysics Data System (ADS)

    Yang, Fu-Jiang; Xie, Shi-Jie

    2014-09-01

    For the organic magnetoresistance (OMAR) effect, we suggest a spin-related hopping of carriers (polarons) based on Marcus theory. The mobility of polarons is calculated with the master equation (ME) and then the magnetoresistance (MR) is obtained. The theoretical results are consistent with the experimental observation. Especially, the sign inversion of the MR under different driving bias voltages found in the experiment is predicted. Besides, the effects of molecule disorder, hyperfine interaction (HFI), polaron localization, and temperature on the MR are investigated.

  13. Learning Processes and Social Mobilization in a Swedish Metropolitan Hip-Hop Collective

    ERIC Educational Resources Information Center

    Beach, Dennis; Sernhede, Ove

    2012-01-01

    Based on ethnographic research on the encounter between local culture and schools in multicultural suburban areas, this article explores possibilities suggested by autonomous learning activities in a hip-hop collective that may have a potential to break urban segregation patterns. The collective's artistic production raises questions that have not…

  14. "Folkbildning" through Hip-Hop: How the Ideals of Three Rappers Parallel a Scandinavian Educational Tradition

    ERIC Educational Resources Information Center

    Soderman, Johan

    2011-01-01

    The purpose of this article is to show how the rappers' talk about hip-hop and its connection to pedagogy and social activism parallel the Scandinavian tradition of folkbildning. Scandinavian folkbildning can be seen as a movement to provide voluntary education for the general population. It can also be the name of the process of learning in which…

  15. Violence, Nonviolence, and the Lessons of History: Project HIP-HOP Journeys South.

    ERIC Educational Resources Information Center

    Murray, Nancy Uhlar; Garrido, Marco

    1995-01-01

    The first part describes Project HIP-HOP (Highways into the Past: Organizing and Power), in which Boston students visited key sites of the civil rights movement and learned about nonviolence from participants. In the second part, a student describes what he learned about racism and activism. (SK)

  16. Hopping magnetoresistance in ion irradiated monolayer graphene

    NASA Astrophysics Data System (ADS)

    Shlimak, I.; Zion, E.; Butenko, A. V.; Wolfson, L.; Richter, V.; Kaganovskii, Yu.; Sharoni, A.; Haran, A.; Naveh, D.; Kogan, E.; Kaveh, M.

    2016-02-01

    Magnetoresistance (MR) of ion irradiated monolayer graphene samples with a variable-range hopping (VRH) mechanism of conductivity was measured at temperatures down to T=1.8 K in magnetic fields up to B=8 T. It was observed that in perpendicular magnetic fields, hopping resistivity R decreases, which corresponds to negative MR (NMR), while parallel magnetic field results in positive MR (PMR) at low temperatures. NMR is explained on the basis of the "orbital" model in which perpendicular magnetic field suppresses the destructive interference of many paths through the intermediate sites in the total probability of the long-distance tunneling in the VRH regime. At low fields, a quadratic dependence (| ΔR / R | ∼ B2) of NMR is observed, while at B > B*, the quadratic dependence is replaced by the linear one. It was found that all NMR curves for different samples and different temperatures could be merged into common dependence when plotted as a function of B/B*. It is shown that B* ∼ T1/2 in agreement with predictions of the "orbital" model. The obtained values of B* also allowed us to estimate the localization radius ξ of charge carriers for samples with a different degree of disorder. PMR in parallel magnetic fields is explained by suppression of hopping transitions via double occupied states due to alignment of electron spins.

  17. Metabolism of hop-derived bitter acids.

    PubMed

    Cattoor, Ko; Dresel, Michael; De Bock, Lies; Boussery, Koen; Van Bocxlaer, Jan; Remon, Jean-Paul; De Keukeleire, Denis; Deforce, Dieter; Hofmann, Thomas; Heyerick, Arne

    2013-08-21

    In this study, in vitro metabolism of hop-derived bitter acids was investigated. Besides their well-known use as bitter compounds in beer, in several studies, bioactive properties have been related to these types of molecules. However, scientific data on the absorption, distribution, metabolism, and excretion aspects of these compounds are limited. More specific, in this study, α-acids, β-acids, and iso-α-acids were incubated with rabbit microsomes, and fractions were subjected to LC-MS/MS analysis for identification of oxidative biotransformation products. Metabolism of β-acids was mainly characterized by conversion into hulupones and the formation of a series of tricyclic oxygenated products. The most important metabolites of α-acids were identified as humulinones and hulupones. Iso-α-acids were found to be primarly metabolized into cis- and trans-humulinic acids, next to oxidized alloiso-α-acids. Interestingly, the phase I metabolites were highly similar to the oxidative degradation products in beer. These findings show a first insight into the metabolites of hop-derived bitter acids and could have important practical implications in the bioavailability aspects of these compounds, following ingestion of hop-based food products and nutraceuticals.

  18. Hops for Menopausal Vasomotor Symptoms: Mechanisms of Action

    PubMed Central

    Abdi, Fatemeh; Mobedi, Hamid

    2016-01-01

    Menopause is a critical stage of women's life associated with various complaints and distresses. Vasomotor symptoms (VMS), such as hot flushes, night sweats, sleep disturbances, and fatigue, are the most common menopause symptoms affecting about 50% to 80% of middle-aged women. Obviously, these symptoms, resulting from estrogen deficiency during menopause, can exert negative effects on women's health and quality of life and thus require to be managed through approaches such as hormone replacement therapy (HRT). Many herbal treatments for menopause symptoms contain and its components such as 8-prenylnaringenin, 6-PN, isoxanthohumol and xanthohumol. Recent in-vivo studies have highlighted the ability of 8-prenylnaringenin to reduce serum-luteinizing hormone (LH) and follicle-stimulating hormone (FSH), to increase serum prolactin levels and uterine weight, and to induce vaginal hyperplastic epithelium. Previous research has shown that hops extract can strongly bind to both estrogen receptors, stimulate alkaline phosphatase activity in Ishikawa cells, and upregulate presenelin-2 and progesterone receptor mRNA in Ishikawa cells. Numerous clinical trials have documented significant reductions in the frequency of hot flushes following the administration of hop-containing preparations. Nevertheless, further clinical trials with larger sample size and longer follow-up are warranted to confirm such benefits. PMID:27617238

  19. Expression of lipoxygenase during organogenic nodule formation from hop internodes.

    PubMed

    Fortes, Ana Margarida; Coronado, Maria José; Testillano, Pilar S; Risueño, Maria del Carmen; Pais, Maria Salomé

    2004-02-01

    Study of lipoxygenase expression (LOX; EC 1.13.11.12) during organogenic nodule formation in hop (Humulus lupulus var. Nugget) showed that LOXs are developmentally regulated throughout the process, suggesting their involvement in the response of internodes to wounding, nodule formation, and plantlet regeneration from these nodules. LOX activity and lipid peroxides exhibited a huge increase during the first week of culture, which may indicate a role for LOX and LOX products in response to wounding in hop, as reported for other systems. Western blotting analysis showed a de novo synthesis of LOX isoenzymes in response to wounding and the detection of three different isoenzymes. Confocal analysis of LOX immunofluorescence revealed the presence of the enzyme in cortical cells of induced internodes and in prenodular cells, mostly appearing as cytoplasmic spots. Some of them were identified as lipid bodies by cytochemical and double immunofluorescence assays, suggesting the involvement of a lipid body LOX during nodule formation. Immunogold labeling detected LOX in peroxisomes, lipid bodies, and plastids of nodular cells. Quantification of the labeling density provided statistical significance for the localization of LOX (three different isoenzymes) in the three compartments, which suggested a possible involvement of LOX in metabolic functions of these organelles during organogenic nodule formation and plantlet regeneration.

  20. Promoting Physical Activity and Exercise in Daily Practice: Current Practices, Barriers, and Training Needs of Physiotherapists in Eastern Nigeria

    PubMed Central

    Edeonuh, Juliet Chinonso; Frantz, Jose

    2016-01-01

    Purpose: To investigate current practices, barriers, and training needs for the promotion of physical activity (PA) in physiotherapy practices in eastern Nigeria. Methods: A total of 141 fully licensed physiotherapists in southeast Nigeria were invited to participate in a cross-sectional survey consisting of 23 questions in five key sections, focusing mainly on risk-factor management practices of physiotherapists. Results: A total of 103 questionnaires were returned. Respondents ranged in age from 25 to 54 years and reported a mean of 11 (SD 10) years of clinical experience. Respondents reported that they regularly assess and advise their clients on PA but rarely give written prescriptions. Although they are confident in assessing and advising their clients on PA and consider including PA intervention as a priority in daily practice, lack of time and lack of access to materials were reported as barriers to effective PA intervention. Conclusion: Findings showed the potential for physiotherapists to address physical inactivity and highlighted several barriers. Strategies are needed to improve contact time with clients and make material promoting PA available to practising physiotherapists. PMID:27504046

  1. Barriers, facilitators and preferences for the physical activity of school children. Rationale and methods of a mixed study

    PubMed Central

    2012-01-01

    Background Physical activity interventions in schools environment seem to have shown some effectiveness in the control of the current obesity epidemic in children. However the complexity of behaviors and the diversity of influences related to this problem suggest that we urgently need new lines of insight about how to support comprehensive population strategies of intervention. The aim of this study was to know the perceptions of the children from Cuenca, about their environmental barriers, facilitators and preferences for physical activity. Methods/Design We used a mixed-method design by combining two qualitative methods (analysis of individual drawings and focus groups) together with the quantitative measurement of physical activity through accelerometers, in a theoretical sample of 121 children aged 9 and 11 years of schools in the province of Cuenca, Spain. Conclusions Mixed-method study is an appropriate strategy to know the perceptions of children about barriers and facilitators for physical activity, using both qualitative methods for a deeply understanding of their points of view, and quantitative methods for triangulate the discourse of participants with empirical data. We consider that this is an innovative approach that could provide knowledges for the development of more effective interventions to prevent childhood overweight. PMID:22978490

  2. Metformin induces up-regulation of blood-brain barrier functions by activating AMP-activated protein kinase in rat brain microvascular endothelial cells.

    PubMed

    Takata, Fuyuko; Dohgu, Shinya; Matsumoto, Junichi; Machida, Takashi; Kaneshima, Shuji; Matsuo, Mai; Sakaguchi, Shinya; Takeshige, Yuki; Yamauchi, Atsushi; Kataoka, Yasufumi

    2013-04-19

    Blood-brain barrier (BBB) disruption occurs frequently in CNS diseases and injuries. Few drugs have been developed as therapeutic candidates for facilitating BBB functions. Here, we examined whether metformin up-regulates BBB functions using rat brain microvascular endothelial cells (RBECs). Metformin, concentration- and time-dependently increased transendothelial electrical resistance of RBEC monolayers, and decreased RBEC permeability to sodium fluorescein and Evans blue albumin. These effects of metformin were blocked by compound C, an inhibitor of AMP-activated protein kinase (AMPK). AMPK stimulation with an AMPK activator, AICAR, enhanced BBB functions. These findings indicate that metformin induces up-regulation of BBB functions via AMPK activation.

  3. The HOPS/Class C Vps Complex Tethers High-Curvature Membranes via a Direct Protein-Membrane Interaction.

    PubMed

    Ho, Ruoya; Stroupe, Christopher

    2016-10-01

    Membrane tethering is a physical association of two membranes before their fusion. Many membrane tethering factors have been identified, but the interactions that mediate inter-membrane associations remain largely a matter of conjecture. Previously, we reported that the homotypic fusion and protein sorting/Class C vacuolar protein sorting (HOPS/Class C Vps) complex, which has two binding sites for the yeast vacuolar Rab GTPase Ypt7p, can tether two low-curvature liposomes when both membranes bear Ypt7p. Here, we show that HOPS tethers highly curved liposomes to Ypt7p-bearing low-curvature liposomes even when the high-curvature liposomes are protein-free. Phosphorylation of the curvature-sensing amphipathic lipid-packing sensor (ALPS) motif from the Vps41p HOPS subunit abrogates tethering of high-curvature liposomes. A HOPS complex without its Vps39p subunit, which contains one of the Ypt7p binding sites in HOPS, lacks tethering activity, though it binds high-curvature liposomes and Ypt7p-bearing low-curvature liposomes. Thus, HOPS tethers highly curved membranes via a direct protein-membrane interaction. Such high-curvature membranes are found at the sites of vacuole tethering and fusion. There, vacuole membranes bend sharply, generating large areas of vacuole-vacuole contact. We propose that HOPS localizes via the Vps41p ALPS motif to these high-curvature regions. There, HOPS binds via Vps39p to Ypt7p in an apposed vacuole membrane.

  4. Rethinking Pedagogy in Urban Spaces: Implementing Hip-Hop Pedagogy in the Urban Science Classroom

    ERIC Educational Resources Information Center

    Adjapong, Edmund S.; Emdin, Christopher

    2015-01-01

    A significant amount of research regarding Hip-Hop Based Education (HHBE) fails to provide insight on how to incorporate elements of Hip-Hop into daily teaching practices; rather Hip-Hop based educators focus mainly on incorporating Hip-Hop culture into curricula. This study explores the benefits of using two specific Hip-Hop pedagogical practices…

  5. Basic and clinical research on the regulation of the intestinal barrier by Lactobacillus and its active protein components: a review with experience of one center.

    PubMed

    Liu, Zhi-Hua; Kang, Liang; Wang, Jian-Ping

    2014-12-01

    Probiotics got protective effects on the intestinal barrier. Our present study is to review the basic and clinical progress on the regulation of the intestinal barrier by Lactobacillus and its active protein components, combing the study of our center. Our study have isolated the active component of micro integral membrane protein (MIMP) within the media place of the integral membrane protein of Lactobacillus plantarum, which was verified about the protective effects against the intestinal epithelial dysfunction. On the other hand, we also found the effects of perioperative use of probiotics in the prevention and treatment of postoperative intestinal barrier dysfunction, and reduction of the postoperative infective complications. In this review, we would like to report the founding of our center, involving in the basic and clinical research progress of regulation of intestinal barrier by Lactobacillus and its active protein component MIMP. Furthermore, we may also promote our following studies about the MIMP and its clinical verification.

  6. Histamine activates p38 MAP kinase and alters local lamellipodia dynamics, reducing endothelial barrier integrity and eliciting central movement of actin fibers.

    PubMed

    Adderley, Shaquria P; Lawrence, Curtis; Madonia, Eyong; Olubadewo, Joseph O; Breslin, Jerome W

    2015-07-01

    The role of the actin cytoskeleton in endothelial barrier function has been debated for nearly four decades. Our previous investigation revealed spontaneous local lamellipodia in confluent endothelial monolayers that appear to increase overlap at intercellular junctions. We tested the hypothesis that the barrier-disrupting agent histamine would reduce local lamellipodia protrusions and investigated the potential involvement of p38 mitogen-activated protein (MAP) kinase activation and actin stress fiber formation. Confluent monolayers of human umbilical vein endothelial cells (HUVEC) expressing green fluorescent protein-actin were studied using time-lapse fluorescence microscopy. The protrusion and withdrawal characteristics of local lamellipodia were assessed before and after addition of histamine. Changes in barrier function were determined using electrical cell-substrate impedance sensing. Histamine initially decreased barrier function, lamellipodia protrusion frequency, and lamellipodia protrusion distance. A longer time for lamellipodia withdrawal and reduced withdrawal distance and velocity accompanied barrier recovery. After barrier recovery, a significant number of cortical fibers migrated centrally, eventually resembling actin stress fibers. The p38 MAP kinase inhibitor SB203580 attenuated the histamine-induced decreases in barrier function and lamellipodia protrusion frequency. SB203580 also inhibited the histamine-induced decreases in withdrawal distance and velocity, and the subsequent actin fiber migration. These data suggest that histamine can reduce local lamellipodia protrusion activity through activation of p38 MAP kinase. The findings also suggest that local lamellipodia have a role in maintaining endothelial barrier integrity. Furthermore, we provide evidence that actin stress fiber formation may be a reaction to, rather than a cause of, reduced endothelial barrier integrity.

  7. Communication: Optimal parameters for basin-hopping global optimization based on Tsallis statistics

    SciTech Connect

    Shang, C. Wales, D. J.

    2014-08-21

    A fundamental problem associated with global optimization is the large free energy barrier for the corresponding solid-solid phase transitions for systems with multi-funnel energy landscapes. To address this issue we consider the Tsallis weight instead of the Boltzmann weight to define the acceptance ratio for basin-hopping global optimization. Benchmarks for atomic clusters show that using the optimal Tsallis weight can improve the efficiency by roughly a factor of two. We present a theory that connects the optimal parameters for the Tsallis weighting, and demonstrate that the predictions are verified for each of the test cases.

  8. Using community-based participatory research to identify potential interventions to overcome barriers to adolescents’ healthy eating and physical activity

    PubMed Central

    Goh, Ying-Ying; Sipple-Asher, Bessie Ko; Uyeda, Kimberly; Hawes-Dawson, Jennifer; Olarita-Dhungana, Josephina; Ryan, Gery W.; Schuster, Mark A.

    2010-01-01

    Using a community-based participatory research approach, we explored adolescent, parent, and community stakeholder perspectives on barriers to healthy eating and physical activity, and intervention ideas to address adolescent obesity. We conducted 14 adolescent focus groups (n = 119), 8 parent focus groups (n = 63), and 28 interviews with community members (i.e., local experts knowledgeable about youth nutrition and physical activity). Participants described ecological and psychosocial barriers in neighborhoods (e.g., lack of accessible nutritious food), in schools (e.g., poor quality of physical education), at home (e.g., sedentary lifestyle), and at the individual level (e.g., lack of nutrition knowledge). Participants proposed interventions such as nutrition classes for families, addition of healthy school food options that appeal to students, and non-competitive physical education activities. Participants supported health education delivered by students. Findings demonstrate that community-based participatory research is useful for revealing potentially feasible interventions that are acceptable to community members. PMID:19544091

  9. Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion

    PubMed Central

    Ryham, Rolf J.; Klotz, Thomas S.; Yao, Lihan; Cohen, Fredric S.

    2016-01-01

    We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm. PMID:26958888

  10. Activism on rifapentine pricing: removing cost barriers to improve the uptake of tuberculosis research innovations

    PubMed Central

    Frick, M.; Lessem, E.; Kanouse, J.; Wegener, D.; Mingote, L. Ruiz

    2014-01-01

    As recent advances have been made in developing tools to fight tuberculosis (TB), there is also a trend towards increasing advocacy by the civil society for TB research and access. One recent successful effort to increase access to treatment options for TB involved a collaborative effort to identify the need for and barriers to the use of rifapentine (RPT) use in the United States. Survey responses confirmed the under-utilization of RPT: 82% of survey respondents selected cost as a significant or potential barrier to use. Survey results provided data to support a year-long advocacy campaign urging the drug company Sanofi to lower the price of RPT. This campaign was based on a common evidence base built in part by the stakeholders themselves. After multiple engagements with communities and providers, Sanofi US announced on 12 December 2013 that they would drop the price of RPT to US$32 per blister pack of 32 tablets for US public health programs. While further work remains to secure access to RPT in the United States and worldwide, the lowering of the price of RPT reflects the positive impact that collaborative advocacy can accomplish, and sets an example for other drug companies to follow. PMID:26400702

  11. Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion.

    PubMed

    Ryham, Rolf J; Klotz, Thomas S; Yao, Lihan; Cohen, Fredric S

    2016-03-08

    We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm.

  12. Activism on rifapentine pricing: removing cost barriers to improve the uptake of tuberculosis research innovations.

    PubMed

    DeLuca, A; Frick, M; Lessem, E; Kanouse, J; Wegener, D; Mingote, L Ruiz

    2014-12-21

    As recent advances have been made in developing tools to fight tuberculosis (TB), there is also a trend towards increasing advocacy by the civil society for TB research and access. One recent successful effort to increase access to treatment options for TB involved a collaborative effort to identify the need for and barriers to the use of rifapentine (RPT) use in the United States. Survey responses confirmed the under-utilization of RPT: 82% of survey respondents selected cost as a significant or potential barrier to use. Survey results provided data to support a year-long advocacy campaign urging the drug company Sanofi to lower the price of RPT. This campaign was based on a common evidence base built in part by the stakeholders themselves. After multiple engagements with communities and providers, Sanofi US announced on 12 December 2013 that they would drop the price of RPT to US$32 per blister pack of 32 tablets for US public health programs. While further work remains to secure access to RPT in the United States and worldwide, the lowering of the price of RPT reflects the positive impact that collaborative advocacy can accomplish, and sets an example for other drug companies to follow.

  13. Molecular phylogeny of wild hops, Humulus lupulus L.

    PubMed

    Murakami, A; Darby, P; Javornik, B; Pais, M S S; Seigner, E; Lutz, A; Svoboda, P

    2006-07-01

    We have analysed wild hops collected widely from the Northern Hemisphere, assessing the genetic diversity and the geographical distribution of haplotypes, to investigate the evolution and phylogeny of hops, Humulus lupulus. The haplotypes were characterized by the nuclear ribosomal DNA spacer region (length and DNA sequence) and chloroplast DNA noncoding regions (DNA sequences). The results indicated that primary divergence into European (including Caucasus and Altai hops), and Asian-North American types, was 1.05+/-0.28 to 1.27+/-0.30 million years ago. Although an Eastern boundary for European nuclear haplotype distribution was unclear due to the ambiguous origin of Northern Chinese samples, the European hop group showed a wide geographical distribution across Eurasia from the Altai region to Portugal. The low genetic variation in this group suggested rapid and recent expansion. The North American hop group showed high diversity, and is considered to include hops that have migrated from Asia. Japanese and Chinese hops were identified as genetically distinct. This study has shown that wild hops in each growing region are genetically differentiated with considerable genetic diversity. It gives insights into the evolution and domestication of hops that are discussed.

  14. Structure and DNA-binding of meiosis-specific protein Hop2

    NASA Astrophysics Data System (ADS)

    Zhou, Donghua; Moktan, Hem; Pezza, Roberto

    2014-03-01

    Here we report structure elucidation of the DNA binding domain of homologous pairing protein 2 (Hop2), which is important to gene diversity when sperms and eggs are produced. Together with another protein Mnd1, Hop2 enhances the strand invasion activity of recombinase Dmc1 by over 30 times, facilitating proper synapsis of homologous chromosomes. However, the structural and biochemical bases for the function of Hop2 and Mnd1 have not been well understood. As a first step toward such understanding, we recently solved the structure for the N-terminus of Hop2 (1-84) using solution NMR. This fragment shows a typical winged-head conformation with recognized DNA binding activity. DNA interacting sites were then investigated by chemical shift perturbations in a titration experiment. Information of these sites was used to guide protein-DNA docking with MD simulation, revealing that helix 3 is stably lodged in the DNA major groove and that wing 1 (connecting strands 2 and 3) transiently comes in contact with the minor groove in nanosecond time scale. Mutagenesis analysis further confirmed the DNA binding sites in this fragment of the protein.

  15. Hopping conduction and its photoquenching in molecular beam epitaxial GaAs grown at low temperatures

    SciTech Connect

    Fang, Z.Q.; Look, D.C.

    1993-12-01

    As the growth temperature of molecular beam epitaxial GaAs is increased from 250 to 400{degrees}C, the dominant conduction changes from hopping conduction to band conduction with a donor activation energy of 0.65 eV. A 300{degrees}C grown layer is especially interesting because each conduction mechanism is dominant in a particular temperature range, hopping below 300K and band conduction above. Below 140K, the hopping conduction is greatly diminished (quenched) by irradiation with either infrared (hv {le} 1.12 eV) or 1.46 eV light, but then recovers above 140K with exactly the same thermal kinetics as are found for the famous EL2. Thus, the 0.65 eV donor, which is responsible for both the hopping and band conduction, is very similar to EL2, but not identical because of the different activation energy (0.65 eV vs 0.75 eV for EL2). 12 refs., 4 figs.

  16. Indirect evidence for elastic energy playing a role in limb recovery during toad hopping.

    PubMed

    Schnyer, Ariela; Gallardo, Mirialys; Cox, Suzanne; Gillis, Gary

    2014-07-01

    Elastic energy is critical for amplifying muscle power during the propulsive phase of anuran jumping. In this study, we use toads (Bufo marinus) to address whether elastic recoil is also involved after take-off to help flex the limbs before landing. The potential for such spring-like behaviour stems from the unusually flexed configuration of a toad's hindlimbs in a relaxed state. Manual extension of the knee beyond approximately 90° leads to the rapid development of passive tension in the limb as underlying elastic tissues become stretched. We hypothesized that during take-off, the knee regularly extends beyond this, allowing passive recoil to help drive limb flexion in mid-air. To test this, we used high-speed video and electromyography to record hindlimb kinematics and electrical activity in a hindlimb extensor (semimembranosus) and flexor (iliofibularis). We predicted that hops in which the knees extended further during take-off would require less knee flexor recruitment during recovery. Knees extended beyond 90° in over 80% of hops, and longer hops involved greater degrees of knee extension during take-off and more intense semimembranosus activity. However, knee flexion velocities during recovery were maintained despite a significant decrease in iliofibularis intensity in longer hops, results consistent with elastic recoil playing a role.

  17. Indirect evidence for elastic energy playing a role in limb recovery during toad hopping

    PubMed Central

    Schnyer, Ariela; Gallardo, Mirialys; Cox, Suzanne; Gillis, Gary

    2014-01-01

    Elastic energy is critical for amplifying muscle power during the propulsive phase of anuran jumping. In this study, we use toads (Bufo marinus) to address whether elastic recoil is also involved after take-off to help flex the limbs before landing. The potential for such spring-like behaviour stems from the unusually flexed configuration of a toad's hindlimbs in a relaxed state. Manual extension of the knee beyond approximately 90° leads to the rapid development of passive tension in the limb as underlying elastic tissues become stretched. We hypothesized that during take-off, the knee regularly extends beyond this, allowing passive recoil to help drive limb flexion in mid-air. To test this, we used high-speed video and electromyography to record hindlimb kinematics and electrical activity in a hindlimb extensor (semimembranosus) and flexor (iliofibularis). We predicted that hops in which the knees extended further during take-off would require less knee flexor recruitment during recovery. Knees extended beyond 90° in over 80% of hops, and longer hops involved greater degrees of knee extension during take-off and more intense semimembranosus activity. However, knee flexion velocities during recovery were maintained despite a significant decrease in iliofibularis intensity in longer hops, results consistent with elastic recoil playing a role. PMID:25030045

  18. Barriers and facilitators to participation in workplace health promotion (WHP) activities: results from a cross-sectional survey of public-sector employees in Tasmania, Australia.

    PubMed

    Kilpatrick, Michelle; Blizzard, Leigh; Sanderson, Kristy; Teale, Brook; Jose, Kim; Venn, Alison

    2017-01-19

    Issue addressed: Workplaces are promising settings for health promotion, yet employee participation in workplace health promotion (WHP) activities is often low or variable. This study explored facilitating factors and barriers associated with participation in WHP activities that formed part of a comprehensive WHP initiative run within the Tasmanian State Service (TSS) between 2009 and 2013.Methods: TSS employee (n=3228) completed surveys in 2013. Data included sociodemographic characteristics, employee-perceived availability of WHP activities, employee-reported participation in WHP activities, and facilitators and barriers to participation. Ordinal log-link regression was used in cross-sectional analyses.Results: Significant associations were found for all facilitating factors and participation. Respondents who felt their organisation placed a high priority on WHP, who believed that management supported participation or that the activities could improve their health were more likely to participate. Time- and health-related barriers were associated with participation in fewer activities. All associations were independent of age, sex, work schedule and employee-perceived availability of programs. Part-time and shift-work patterns, and location of activities were additionally identified barriers.Conclusion: Facilitating factors relating to implementation, peer and environmental support, were associated with participation in more types of activities, time- and health-related barriers were associated with less participation.So what?: Large and diverse organisations should ensure WHP efforts have manager support and adopt flexible approaches to maximise employee engagement.

  19. Nonlinear hopping transport in ring systems and open channels.

    PubMed

    Einax, Mario; Körner, Martin; Maass, Philipp; Nitzan, Abraham

    2010-01-21

    We study the nonlinear hopping transport in one-dimensional rings and open channels. Analytical results are derived for the stationary current response to a constant bias without assuming any specific coupling of the rates to the external fields. It is shown that anomalous large effective jump lengths, as observed in recent experiments by taking the ratio of the third-order nonlinear and the linear conductivity, can occur already in ordered systems. Rectification effects due to site energy disorder in ring systems are expected to become irrelevant for large system sizes. In open channels, in contrast, rectification effects occur already for disorder in the jump barriers and do not vanish in the thermodynamic limit. Numerical solutions for a sinusoidal bias show that the ring system provides a good description for the transport behavior in the open channel for intermediate and high frequencies. For low frequencies temporal variations in the mean particle number have to be taken into account in the open channel, which cannot be captured in the more simple ring model.

  20. Perceived barriers and facilitators to increasing physical activity among people with musculoskeletal disorders: a qualitative investigation to inform intervention development

    PubMed Central

    McPhail, Steven M; Schippers, Mandy; Marshall, Alison L; Waite, Monique; Kuipers, Pim

    2014-01-01

    Purpose Musculoskeletal conditions can impair people’s ability to undertake physical activity as they age. The purpose of this qualitative study was to investigate perceived barriers and facilitators to undertaking physical activity reported by patients accessing ambulatory hospital clinics for musculoskeletal disorders. Patients and methods A questionnaire with open-ended items was administered to patients (n=217, 73.3% of 296 eligible) from three clinics providing ambulatory services for nonsurgical treatment of musculoskeletal disorders. The survey included questions to capture the clinical and demographic characteristics of the sample. It also comprised two open-ended questions requiring qualitative responses. The first asked the participant to describe factors that made physical activity more difficult, and the second asked which factors made it easier for them to be physically active. Participants’ responses to the two open-ended questions were read, coded, and thematically analyzed independently by two researchers, with a third researcher available to arbitrate any unresolved disagreement. Results The mean (standard deviation) age of participants was 53 (15) years; n=113 (52.1%) were male. A total of 112 (51.6%) participants reported having three or more health conditions; n=140 (64.5%) were classified as overweight or obese. Five overarching themes describing perceived barriers for undertaking physical activity were “health conditions”, “time restrictions”, “poor physical condition”, “emotional, social, and psychological barriers”, and “access to exercise opportunities”. Perceived physical activity facilitators were also aligned under five themes, namely “improved health state”, “social, emotional, and behavioral supports”, “access to exercise environment”, “opportunities for physical activities”, and “time availability”. Conclusion It was clear from the breadth of the data that meaningful supports and

  1. Activation of RhoA, but Not Rac1, Mediates Early Stages of S1P-Induced Endothelial Barrier Enhancement.

    PubMed

    Zhang, Xun E; Adderley, Shaquria P; Breslin, Jerome W

    2016-01-01

    Compromised endothelial barrier function is a hallmark of inflammation. Rho family GTPases are critical in regulating endothelial barrier function, yet their precise roles, particularly in sphingosine-1-phosphate (S1P)-induced endothelial barrier enhancement, remain elusive. Confluent cultures of human umbilical vein endothelial cells (HUVEC) or human dermal microvascular endothelial cells (HDMEC) were used to model the endothelial barrier. Barrier function was assessed by determining the transendothelial electrical resistance (TER) using an electrical cell-substrate impedance sensor (ECIS). The roles of Rac1 and RhoA were tested in S1P-induced barrier enhancement. The results show that pharmacologic inhibition of Rac1 with Z62954982 failed to block S1P-induced barrier enhancement. Likewise, expression of a dominant negative form of Rac1, or knockdown of native Rac1 with siRNA, failed to block S1P-induced elevations in TER. In contrast, blockade of RhoA with the combination of the inhibitors Rhosin and Y16 significantly reduced S1P-induced increases in TER. Assessment of RhoA activation in real time using a fluorescence resonance energy transfer (FRET) biosensor showed that S1P increased RhoA activation primarily at the edges of cells, near junctions. This was complemented by myosin light chain-2 phosphorylation at cell edges, and increased F-actin and vinculin near intercellular junctions, which could all be blocked with pharmacologic inhibition of RhoA. The results suggest that S1P causes activation of RhoA at the cell periphery, stimulating local activation of the actin cytoskeleton and focal adhesions, and resulting in endothelial barrier enhancement. S1P-induced Rac1 activation, however, does not appear to have a significant role in this process.

  2. Diffusion barriers

    NASA Technical Reports Server (NTRS)

    Nicolet, M. A.

    1983-01-01

    The choice of the metallic film for the contact to a semiconductor device is discussed. One way to try to stabilize a contact is by interposing a thin film of a material that has low diffusivity for the atoms in question. This thin film application is known as a diffusion barrier. Three types of barriers can be distinguished. The stuffed barrier derives its low atomic diffusivity to impurities that concentrate along the extended defects of a polycrystalline layer. Sacrificial barriers exploit the fact that some (elemental) thin films react in a laterally uniform and reproducible fashion. Sacrificial barriers have the advantage that the point of their failure is predictable. Passive barriers are those most closely approximating an ideal barrier. The most-studied case is that of sputtered TiN films. Stuffed barriers may be viewed as passive barriers whose low diffusivity material extends along the defects of the polycrystalline host.

  3. Dynamic control of muscle stiffness and H reflex modulation during hopping and jumping in man.

    PubMed Central

    Dyhre-Poulsen, P; Simonsen, E B; Voigt, M

    1991-01-01

    1. The objective of the study was to evaluate the functional effects of reflexes on muscle mechanics during natural voluntary movements. The excitability of the H (Hoffmann) reflex was used as a measure of the excitability of the central component of the stretch reflex. 2. We recorded EMG, ground reaction forces and the H reflex in the soleus muscle in humans while landing from a downward jump, during drop jumping and during hopping. The movements were also recorded by high-speed cinematography. 3. The EMG pattern was adapted to the motor task. When landing the EMG in the soleus muscle and in the anterior tibial muscle showed preinnervation and alternating activity after touch down. When hopping there was little preinnervation in the soleus muscle, and the activity was initiated about 45 ms after touch down by a peak and continued unbroken until lift off. In the drop jumps the EMG pattern depended on the jumping style used by the subject. 4. The H reflex in the soleus muscle was strongly modulated in a manner appropriate to the requirements of the motor task. During landing from a downward jump the H reflex was low at touch down whereas while hopping it was high at touch down. During drop jumping it was variable and influenced by the jumping technique. 5. Muscle stiffness in the ankle joint was negative after touch down when landing, but always positive when hopping. 6. It is suggested that during landing the alternating EMG pattern after touch down was programmed and little influenced by reflexes. During hopping reflexes could contribute to the initial peak and the EMG during lift off. 7. The programmed EMG activity and the suppression of the H reflex while landing probably contribute to the development of the negative stiffness and change the muscles from a spring to a damping unit. PMID:1890636

  4. The component content of active particles in a plasma-chemical reactor based on volume barrier discharge

    NASA Astrophysics Data System (ADS)

    Soloshenko, I. A.; Tsiolko, V. V.; Pogulay, S. S.; Terent'yeva, A. G.; Bazhenov, V. Yu; Shchedrin, A. I.; Ryabtsev, A. V.; Kuzmichev, A. I.

    2007-02-01

    In this paper the results of theoretical and experimental studies of the component content of active particles formed in a plasma-chemical reactor composed of a multiple-cell generator of active particles, based on volume barrier discharge, and a working chamber are presented. For calculation of the content of uncharged plasma components an approach is proposed which is based on averaging of the power introduced over the entire volume. Advantages of such an approach lie in an absence of fitting parameters, such as the dimensions of microdischarges, their surface density and rate of breakdown. The calculation and the experiment were accomplished with the use of dry air (20% relative humidity) as the plasma generating medium. Concentrations of O3, HNO3, HNO2, N2 O5 and NO3 were measured experimentally in the discharge volume and working chamber for the residence time of particles on a discharge of 0.3 s and more and discharge specific power of 1.5 W cm-3. It has been determined that the best agreement between the calculation and the experiment occurs at calculated gas medium temperatures in the discharge plasma of about 400-425 K, which correspond to the experimentally measured rotational temperature of nitrogen. In most cases the calculated concentrations of O3, HNO3, HNO2, N2O5 and NO3 for the barrier discharge and the working chamber are in fairly good agreement with the respective measured values.

  5. Health/Service Providers' Perspectives on Barriers to Healthy Weight Gain and Physical Activity in Pregnant, Urban First Nations Women.

    PubMed

    Darroch, Francine E; Giles, Audrey R

    2016-01-01

    The purpose of this article is to examine health/service providers' perspectives of barriers to healthy weight gain and physical activity for urban, pregnant First Nations women in Ottawa, Canada. Through the use of semi-structured interviews, we explored 15 health/service providers' perspectives on the complex barriers their clients face. By using a postcolonial feminist lens and a social determinants of health framework, we identified three social determinants of health that the health/service providers believed to have the greatest influence on their clients' weight gain and physical activity during pregnancy: poverty, education, and colonialism. Our findings are then contextualized within existing Statistics Canada and the Ottawa Neighbourhood Study data. We found that health/service providers are in a position to challenge colonial relations of power. We conclude by urging health/service providers, researchers, and policymakers alike to take into consideration the ways in which these social determinants of health and their often synergistic effects affect urban First Nations women during pregnancy.

  6. Hip-Hop Is the Healer: Sense of Belonging and Diversity among Hip-Hop Collegians

    ERIC Educational Resources Information Center

    Sulé, V. Thandi

    2016-01-01

    Sense of belonging is recognized as a factor contributing to persistence to graduation. Furthermore, interactional diversity is associated with learning and civic outcomes--touted higher education goals. Hip-hop culture, one of the most influential cultural creations of the mid-20th century, has succeeded in attracting devotees from diverse…

  7. Pharmacokinetics of Prenylated Hop Phenols in Women Following Oral Administration of a Standardized Extract of Hops

    PubMed Central

    van Breemen, Richard B.; Yuan, Yang; Banuvar, Suzanne; Shulman, Lee P.; Qiu, Xi; Alvarenga, René F. Ramos; Chen, Shao-Nong; Dietz, Birgit M.; Bolton, Judy L.; Pauli, Guido F.; Krause, Elizabeth; Viana, Marlos; Nikolic, Dejan

    2014-01-01

    SCOPE Women seeking alternatives to hormone replacement therapy for menopausal symptoms often try botanical dietary supplements containing extracts of hops (Humulus lupulus L.). Hops contain 8-prenylnaringenin (8-PN), a potent phytoestrogen, the related flavanones 6-prenylnaringenin (6-PN) and isoxanthohumol (IX), and the prenylated chalcone xanthohumol (XN). METHODS AND RESULTS After chemically and biologically standardizing an extract of spent hops to these marker compounds, an escalating dose study was carried out in menopausal women to evaluate safety and pharmacokinetics. 8-PN, 6-PN, IX, and XN, sex hormones, and prothrombin time (PT/INR) were determined in blood samples and/or 24-h urine samples. There was no effect on sex hormones or blood clotting. The maximum serum concentrations of the prenylated phenols were dose-dependent and were reached from 2 to 7 h, indicating slow absorption. The marker compounds formed glucuronides that were found in serum and urine. Secondary peaks at 5 h in the serum concentration-time curves indicated enterohepatic recirculation. The serum concentration-time curves indicated demethylation of IX to form 8-PN and cyclization of XN to IX. Slow absorption and enterohepatic recirculation contributed to half-lives exceeding 20 h. CONCLUSION This human study indicated long half-lives of the estrogenic and proestrogenic prenylated phenols in hops but no acute toxicity. PMID:25045111

  8. PAHs in the Great Barrier Reef Lagoon reach potentially toxic levels from coal port activities

    NASA Astrophysics Data System (ADS)

    Burns, Kathryn A.

    2014-05-01

    In view of the controversy over expanding the coastal coal ports bordering the Great Barrier Reef (GBR) Lagoon and the World Heritage Area, I re-evaluated the data published in Burns and Brinkman (2011). I used the US EPA procedures for the determination of Equilibrium Partitioning Sediment Benchmarks (ESBs) for the protection of benthic organisms (Hansen et al., 2003), and the new proposed ANZECC/ARMCANZ (2013) sediment quality guidelines (Simpson et al., 2013) and determined that the coastal sediments offshore from the Hay Point coal terminal and suspended sediments caught in sediment traps inshore and at the offshore coral reefs contained levels of PAHs that approach the estimates for toxicity to benthic and water column organisms. This result is discussed in relation to risks posed to the GBR ecosystem by the port practices and the imminent expansion of the Abbott Point, Hay Point and other coal terminals.

  9. Optimal Hops-Based Adaptive Clustering Algorithm

    NASA Astrophysics Data System (ADS)

    Xuan, Xin; Chen, Jian; Zhen, Shanshan; Kuo, Yonghong

    This paper proposes an optimal hops-based adaptive clustering algorithm (OHACA). The algorithm sets an energy selection threshold before the cluster forms so that the nodes with less energy are more likely to go to sleep immediately. In setup phase, OHACA introduces an adaptive mechanism to adjust cluster head and load balance. And the optimal distance theory is applied to discover the practical optimal routing path to minimize the total energy for transmission. Simulation results show that OHACA prolongs the life of network, improves utilizing rate and transmits more data because of energy balance.

  10. Promoting Physical Activity for Students with Autism Spectrum Disorder: Barriers, Benefits, and Strategies for Success

    ERIC Educational Resources Information Center

    Menear, Kristi S.; Neumeier, William H.

    2015-01-01

    Many students with autism spectrum disorder (ASD) fall short of the recommended physical activity levels and experience challenges in physical activity and physical education settings. This article reviews factors that can improve the physical activity statistics of students with ASD, outlines the researched benefits of physical activity for…

  11. Xanthohumol and related prenylflavonoids from hops and beer: to your good health!

    PubMed

    Stevens, Jan F; Page, Jonathan E

    2004-05-01

    Xanthohumol (3'-[3,3-dimethyl allyl]-2',4',4-trihydroxy-6'-methoxychalcone) is the principal prenylated flavonoid of the female inflorescences of the hop plant ('hops'), an ingredient of beer. Human exposure to xanthohumol and related prenylflavonoids, such as 8-prenylnaringenin and isoxanthohumol, is primarily through beer consumption. Xanthohumol has been characterized a 'broad-spectrum' cancer chemopreventive agent in in vitro studies, while 8-prenylnaringenin enjoys fame as the most potent phytoestrogen known to date. These biological activities suggest that prenylflavonoids from hops have potential for application in cancer prevention programs and in prevention or treatment of (post-)menopausal 'hot flashes' and osteoporosis. Xanthohumol and 8-prenylnaringenin are metabolized into many flavonoid derivatives with modified 3,3-dimethyl allyl (prenyl) moieties. Xanthohumol is formed in lupulin glands by a specialized branch of flavonoid biosynthesis that involves prenylation and O-methylation of the polyketide intermediate chalconaringenin. Although a lupulin gland-specific chalcone synthase is known, the aromatic prenyltransferase and O-methyltransferase participating in xanthohumol have not been identified. The prenylflavonoid pathway is a possible target for breeding or biotechnological modification of hops with the aim of increasing xanthohumol levels for beer brewing and 8-prenylnaringenin levels for pharmaceutical production.

  12. Interaction and dynamics of homologous pairing protein 2 (HOP2) and DNA studied by MD simulation

    NASA Astrophysics Data System (ADS)

    Moktan, Hem; Pezza, Roberto; Zhou, Donghua

    2015-03-01

    The homologous pairing protein 2 (Hop2) plays an important role in meiosis and DNA repair. Together with protein Mnd1, Hop2 enhances the strand invasion activity of recombinase Dmc1 by over 30 times, facilitating proper synapsis of homologous chromosomes. We recently determined the NMR structure of the N-terminal domain of Hop2 and proposed a model of Protein-DNA complex based on NMR chemical shift perturbations and mutagenesis studies (Moktan, J Biol Chem 2014 10.1074/jbc.M114.548180). However structure and dynamics of the complex have not been studied at the atomic level yet. Here, we used classical MD simulations to study the interactions between the N-terminal HOP2 and DNA. The simulated results indicate that helix3 (H3) interacts with DNA in major groove and wing1 (W1) interacts mostly in minor groove mainly via direct hydrogen bonds. Also it is found that binding leads to reduced fluctuations in both protein and DNA. Several water bridge interactions have been identified. The residue-wise contributions to the interaction energy were evaluated. Also the functional motion of the protein is analyzed using principal component analysis. The results confirmed the importance of H3 and W1 for the stability of the complex, which is consistent with our previous experimental studies.

  13. Hopping and the Stokes–Einstein relation breakdown in simple glass formers

    PubMed Central

    Charbonneau, Patrick; Jin, Yuliang; Parisi, Giorgio; Zamponi, Francesco

    2014-01-01

    One of the most actively debated issues in the study of the glass transition is whether a mean-field description is a reasonable starting point for understanding experimental glass formers. Although the mean-field theory of the glass transition—like that of other statistical systems—is exact when the spatial dimension d→∞, the evolution of systems properties with d may not be smooth. Finite-dimensional effects could dramatically change what happens in physical dimensions, d=2,3. For standard phase transitions finite-dimensional effects are typically captured by renormalization group methods, but for glasses the corrections are much more subtle and only partially understood. Here, we investigate hopping between localized cages formed by neighboring particles in a model that allows to cleanly isolate that effect. By bringing together results from replica theory, cavity reconstruction, void percolation, and molecular dynamics, we obtain insights into how hopping induces a breakdown of the Stokes–Einstein relation and modifies the mean-field scenario in experimental systems. Although hopping is found to supersede the dynamical glass transition, it nonetheless leaves a sizable part of the critical regime untouched. By providing a constructive framework for identifying and quantifying the role of hopping, we thus take an important step toward describing dynamic facilitation in the framework of the mean-field theory of glasses. PMID:25288722

  14. New prenylchalcones from the hops of Humulus lupulus.

    PubMed

    Wang, Wen-Shu; Ye, Yun-Hua; Zhou, Ya-Wei

    2008-01-01

    Two new prenylchalcones, xanthohumol C and D, together with two known prenylchalcone derivatives, xanthohumol (1) and 5''-(2''-hydroxyisopropyl)-dihydrofurano-[2'',3''-b]-4,4'-dihydroxy-6'-methoxy-chalcone (4) were isolated and identified from the hops of Humulus lupulus L. The structures of xanhohumol C and D were elucidated as 5''-hydroxy-6'',6''-dimethyl-dihydropyrano-[2'',3''-b]-4,4'-dihydroxy-6'-methoxy-chalcone (2) and 5''-hydroxy-6'',6''-dimethyl-dihydropyrano-[2'',3''-b]-4',6'-dimethoxy-4-hydroxy-chalcone (3) on the basis of HRFAB-MS, 1D and 2D NMR (HMQC, HMBC) spectroscopic data. Among the new prenylchalcones, compound 2 showed marginal cytotoxic activity against human stomach carcinoma BGC-823 and human hepatic carcinoma HepG2 cells.

  15. Activation of VEGF/Flk-1-ERK Pathway Induced Blood-Brain Barrier Injury After Microwave Exposure.

    PubMed

    Wang, Li-Feng; Li, Xiang; Gao, Ya-Bing; Wang, Shui-Ming; Zhao, Li; Dong, Ji; Yao, Bin-Wei; Xu, Xin-Ping; Chang, Gong-Min; Zhou, Hong-Mei; Hu, Xiang-Jun; Peng, Rui-Yun

    2015-08-01

    Microwaves have been suggested to induce neuronal injury and increase permeability of the blood-brain barrier (BBB), but the mechanism remains unknown. The role of the vascular endothelial growth factor (VEGF)/Flk-1-Raf/MAPK kinase (MEK)/extracellular-regulated protein kinase (ERK) pathway in structural and functional injury of the blood-brain barrier (BBB) following microwave exposure was examined. An in vitro BBB model composed of the ECV304 cell line and primary rat cerebral astrocytes was exposed to microwave radiation (50 mW/cm(2), 5 min). The structure was observed by scanning electron microscopy (SEM) and the permeability was assessed by measuring transendothelial electrical resistance (TEER) and horseradish peroxidase (HRP) transmission. Activity and expression of VEGF/Flk-1-ERK pathway components and occludin also were examined. Our results showed that microwave radiation caused intercellular tight junctions to broaden and fracture with decreased TEER values and increased HRP permeability. After microwave exposure, activation of the VEGF/Flk-1-ERK pathway and Tyr phosphorylation of occludin were observed, along with down-regulated expression and interaction of occludin with zonula occludens-1 (ZO-1). After Flk-1 (SU5416) and MEK1/2 (U0126) inhibitors were used, the structure and function of the BBB were recovered. The increase in expression of ERK signal transduction molecules was muted, while the expression and the activity of occludin were accelerated, as well as the interactions of occludin with p-ERK and ZO-1 following microwave radiation. Thus, microwave radiation may induce BBB damage by activating the VEGF/Flk-1-ERK pathway, enhancing Tyr phosphorylation of occludin, while partially inhibiting expression and interaction of occludin with ZO-1.

  16. Understanding hopping transport and thermoelectric properties of conducting polymers

    NASA Astrophysics Data System (ADS)

    Ihnatsenka, S.; Crispin, X.; Zozoulenko, I. V.

    2015-07-01

    We calculate the conductivity σ and the Seebeck coefficient S for the phonon-assisted hopping transport in conducting polymers poly(3,4-ethylenedioxythiophene) or PEDOT, experimentally studied by Bubnova et al. [J. Am. Chem. Soc. 134, 16456 (2012)], 10.1021/ja305188r. We use the Monte Carlo technique as well as the semianalytical approach based on the transport energy concept. We demonstrate that both approaches show a good qualitative agreement for the concentration dependence of σ and S . At the same time, we find that the semianalytical approach is not in a position to describe the temperature dependence of the conductivity. We find that both Gaussian and exponential density of states (DOS) reproduce rather well the experimental data for the concentration dependence of σ and S giving similar fitting parameters of the theory. The obtained parameters correspond to a hopping model of localized quasiparticles extending over 2-3 monomer units with typical jumps over a distance of 3-4 units. The energetic disorder (broadening of the DOS) is estimated to be 0.1 eV. Using the Monte Carlo calculation we reproduce the activation behavior of the conductivity with the calculated activation energy close to the experimentally observed one. We find that for a low carrier concentration a number of free carriers contributing to the transport deviates strongly from the measured oxidation level. Possible reasons for this behavior are discussed. We also study the effect of the dimensionality on the charge transport by calculating the Seebeck coefficient and the conductivity for the cases of three-, two-, and one-dimensional motion.

  17. Collision-based mechanics of bipedal hopping.

    PubMed

    Gutmann, Anne K; Lee, David V; McGowan, Craig P

    2013-08-23

    The muscle work required to sustain steady-speed locomotion depends largely upon the mechanical energy needed to redirect the centre of mass and the degree to which this energy can be stored and returned elastically. Previous studies have found that large bipedal hoppers can elastically store and return a large fraction of the energy required to hop, whereas small bipedal hoppers can only elastically store and return a relatively small fraction. Here, we consider the extent to which large and small bipedal hoppers (tammar wallabies, approx. 7 kg, and desert kangaroo rats, approx. 0.1 kg) reduce the mechanical energy needed to redirect the centre of mass by reducing collisions. We hypothesize that kangaroo rats will reduce collisions to a greater extent than wallabies since kangaroo rats cannot elastically store and return as high a fraction of the mechanical energy of hopping as wallabies. We find that kangaroo rats use a significantly smaller collision angle than wallabies by employing ground reaction force vectors that are more vertical and center of mass velocity vectors that are more horizontal and thereby reduce their mechanical cost of transport. A collision-based approach paired with tendon morphometry may reveal this effect more generally among bipedal runners and quadrupedal trotters.

  18. Perceived Barriers to Teaching Movement and Physical Activity to Kindergarteners in Ghana

    ERIC Educational Resources Information Center

    Sofo, Seidu; Asola, Eugene F.

    2015-01-01

    Regular participation in physical activity can improve students' health and academic achievement. It is important to develop a positive attitude toward participation in regular physical activity early in life. Thus, an understanding of factors that affect the activity levels of young children is essential. Therefore, the purpose of the study was…

  19. Facilitators and Barriers to Physical Activity as Perceived by Older Adults with Intellectual Disability

    ERIC Educational Resources Information Center

    van Schijndel-Speet, Marieke; Evenhuis, Heleen M.; van Wijck, Ruud; van Empelen, Pepijn; Echteld, Michael A.

    2014-01-01

    Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID for specific physical activities, and to gain…

  20. Framing and Reviewing Hip-Hop Educational Research

    ERIC Educational Resources Information Center

    Petchauer, Emery

    2009-01-01

    Hip-hop has become relevant to the field of education because of its implications for understanding language, learning, identity, curriculum, and other areas. This integrative review provides historical context and cohesion for the burgeoning and discursive body of hip-hop scholarship by framing it according to three heuristic categories and…

  1. Towards a Pedagogy of Hip Hop in Urban Teacher Education

    ERIC Educational Resources Information Center

    Bridges, Thurman

    2011-01-01

    This article draws from a qualitative study often Black male K-12 teachers from the Hip Hop Generation who are closely connected to Hip Hop culture and have been effective in addressing the academic and social needs of Black boys. Through an analysis of their social, educational and cultural experiences, this article highlights three organizing…

  2. Hip Hop as Empowerment: Voices in El Alto, Bolivia

    ERIC Educational Resources Information Center

    Tarifa, Ariana

    2012-01-01

    In response to neoliberal policies that have been in place since 1985, Bolivian young people have increasingly used hip hop music as a means of protest and to reclaim social and political participation. Hip hop in Latin America tells the story of the struggles that marginalized people have suffered, and speaks to the effects of international…

  3. Hip-Hop, the "Obama Effect," and Urban Science Education

    ERIC Educational Resources Information Center

    Emdin, Christopher; Lee, Okhee

    2012-01-01

    Background/Context: With the ever increasing diversity of schools, and the persistent need to develop teaching strategies for the students who attend today's urban schools, hip-hop culture has been proposed to be a means through which urban youth can find success in school. As a result, studies of the role of hip-hop in urban education have grown…

  4. Investigating Cultural Collision: Educators' Perceptions of Hip-Hop Culture

    ERIC Educational Resources Information Center

    Beachum, Floyd D.

    2013-01-01

    Hip-hop music has been embraced worldwide by youth, pummeled in the media for supposedly increasing social misery and hailed as a significant musical breakthrough. Hip-hop culture has transcended musical boundaries and now impacts speech, clothing, mannerisms, movies, websites, television programming, magazines, and energy drinks (Dyson, 2007;…

  5. Hip Hop Is Now: An Evolving Youth Culture

    ERIC Educational Resources Information Center

    Taylor, Carl; Taylor, Virgil

    2007-01-01

    Emerging from Rap music, Hip Hop has become a lifestyle to many modern youth around the world. Embodying both creativity and controversy, Hip Hop mirrors the values, violence, and hypocrisy of modern culture. The authors dispel some of the simplistic views that surround this evolving youth movement embraced by millions of young people who are…

  6. [Hopping and superexchange mechanisms of charge transport to DNA].

    PubMed

    Lakhno, V D; Sultanov, V B

    2003-01-01

    A theory for charge transport in nucleobase sequences was constructed in which the hole migration proceeds via hopping between guanines. Each hop over the adenine-thymine (A-T) bridge connecting neighboring guanines occurs by means of the superexchange mechanism. The experimental data and theoretical results for various types of nucleobase sequences are compared.

  7. Christian Hip Hop as Pedagogy: A South African Case Study

    ERIC Educational Resources Information Center

    Abraham, Ibrahim

    2015-01-01

    Drawing on interviews with creators of Christian hip hop music in South Africa, this article demonstrates that this genre of popular music and youth culture is utilised as a form of pedagogy to transmit religious beliefs and values to contemporary youth. The pedagogical aspects of hip hop have been recognised in research on the topic, but the…

  8. Hop powdery mildew control through alteration of spring pruning practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1997, Podosphaera macularis, the causal agent of hop powdery mildew, has become a recurrent threat to hops in the Pacific Northwest because of the potential to reduce cone yield and quality. Disease management practices often involve preventative fungicide applications, but alternative approac...

  9. Toward Hip-Hop Pedagogies for Music Education

    ERIC Educational Resources Information Center

    Kruse, Adam J.

    2016-01-01

    Music education scholarship in the areas of popular, vernacular, and participatory musicianship has grown in the past decades; however, music education research concerned specifically with hip-hop has been relatively scarce. Because hip-hop music can differ tremendously from the traditional western genres with which many music educators are most…

  10. Optimum Detection Of Slow-Frequency-Hopping Signals

    NASA Technical Reports Server (NTRS)

    Levitt, Barry K.; Cheng, Unjeng

    1994-01-01

    Two papers present theoretical analyses of various schemes for coherent and noncoherent detection of M-ary-frequency-shift-keyed (MFSK) signals with slow frequency hopping. Special attention focused on continuous-phase-modulation (CPM) subset of SFH/MFSK signals, for which frequency modulation such carrier phase remains continuous (albeit unknown) during each hop.

  11. Factors of Intensification in the Hops Cluster of Chuvashia

    ERIC Educational Resources Information Center

    Zakharov, Anatoly I.; Evgrafov, Oleg V.; Zakharov, Dmitry A.; Ivanova, Elena V.; Tolstova, Marija L.; Tsaregorodtsev, Evgeny I.

    2016-01-01

    The complex analysis of development of hop-growing for 1971-2015 is carried out. In the conditions of the field experiment made in the Chuvash Republic hop-growing intensification elements--technology of its cultivation, mechanization are fulfilled. Based on researches it is established that the main internal allowance of increase in efficiency of…

  12. Being Hip-Hop: Beyond Skills and Songs

    ERIC Educational Resources Information Center

    Kruse, Adam J.

    2016-01-01

    In this article, I offer four principles relevant to hip-hop cultures (keep it real, flip the script, make some noise, and stay fresh) and explore how these principles might affect music classrooms. I argue that a music classroom that works to keep it real, flip the script, make some noise, and stay fresh might go beyond teaching hip-hop skills…

  13. Chicano Hip-Hop as Interethnic Contact Zone

    ERIC Educational Resources Information Center

    McFarland, Pancho

    2008-01-01

    The critical study of rap music and hip-hop culture has the potential to expand Americans understanding of race and culture in the United States. Hip-hop culture as a multiracial, multiethnic phenomenon reveals the ways in which race relations over the past thirty years have become increasingly complex. The theories and concepts that they use to…

  14. Framing Hip Hop: New Methodologies for New Times

    ERIC Educational Resources Information Center

    Dimitriadis, Greg

    2015-01-01

    This article revisits the central impulse behind early advocacy for ethnographic approaches to hip hop--that critics should try as much as possible to limit their own certainties around what hip hop can and might mean. While ethnographic approaches can engender the kinds of personal dislocations that allow for this negotiation, they do not…

  15. Short and long-term lifestyle coaching approaches used to address diverse participant barriers to weight loss and physical activity adherence

    PubMed Central

    2014-01-01

    Background Individual barriers to weight loss and physical activity goals in the Diabetes Prevention Program, a randomized trial with 3.2 years average treatment duration, have not been previously reported. Evaluating barriers and the lifestyle coaching approaches used to improve adherence in a large, diverse participant cohort can inform dissemination efforts. Methods Lifestyle coaches documented barriers and approaches after each session (mean session attendance = 50.3 ± 21.8). Subjects were 1076 intensive lifestyle participants (mean age = 50.6 years; mean BMI = 33.9 kg/m2; 68% female, 48% non-Caucasian). Barriers and approaches used to improve adherence were ranked by the percentage of the cohort for whom they applied. Barrier groupings were also analyzed in relation to baseline demographic characteristics. Results Top weight loss barriers reported were problems with self-monitoring (58%); social cues (58%); holidays (54%); low activity (48%); and internal cues (thought/mood) (44%). Top activity barriers were holidays (51%); time management (50%); internal cues (30%); illness (29%), and motivation (26%). The percentage of the cohort having any type of barrier increased over the long-term intervention period. A majority of the weight loss barriers were significantly associated with younger age, greater obesity, and non-Caucasian race/ethnicity (p-values vary). Physical activity barriers, particularly thought and mood cues, social cues and time management, physical injury or illness and access/weather, were most significantly associated with being female and obese (p < 0.001 for all). Lifestyle coaches used problem-solving with most participants (≥75% short-term; > 90% long term) and regularly reviewed self-monitoring skills. More costly approaches were used infrequently during the first 16 sessions (≤10%) but increased over 3.2 years. Conclusion Behavioral problem solving approaches have short and long term dissemination potential

  16. Enzymatic reactions by five chalcone synthase homologs from hop (Humulus lupulus L.).

    PubMed

    Okada, Yukio; Sano, Yukie; Kaneko, Takafumi; Abe, Ikuro; Noguchi, Hiroshi; Ito, Kazutoshi

    2004-05-01

    The enzyme activities encoded in five cDNAs for chalcone synthase (CHS) homologs from hop were investigated. Only valerophenone synthase (VPS) and CHS_H1 showed both naringenin-chalcone and phlorisovalerophenone forming activity. Narigenin-chalcone production by VPS was much lower than by CHS_H1. Therefore, it is highly possible that flavonoid depends mainly on CHS_H1, while bitter acid biosynthesis depends mainly on VPS and CHS_H1.

  17. Hop bitter acids exhibit anti-fibrogenic effects on hepatic stellate cells in vitro.

    PubMed

    Saugspier, Michael; Dorn, Christoph; Thasler, Wolfgang E; Gehrig, Manfred; Heilmann, Jörg; Hellerbrand, Claus

    2012-04-01

    Female inflorescences of the hop plant Humulus lupulus L. contain a variety of secondary metabolites with bitter acids (BA) as quantitatively dominating secondary metabolites. The use of hops in beer brewing has a long history due to the antibacterial effects of the BA and their typical bitter taste. Furthermore, hop cones are used in traditional medicine and for pharmaceutical purposes. Recent studies indicate that BA may affect activity of the transcription factor NFκB. NFκB plays a key role in the activation process of hepatic stellate cells (HSC), which is the key event of hepatic fibrosis. The aim of this study was to investigate the effect of BA on HSC (activation) and their potential to inhibit molecular processes involved in the pathogenesis of hepatic fibrosis. HSC were isolated from murine and human liver tissue and incubated with a characterized fraction of bitter acids purified from a CO(2) hop extract. At a concentration of 25μg/ml BA started to induce LDH leakage. Already at lower concentrations BA lead to a dose dependent inhibition of HSC proliferation and inhibited IκB-α-phosphorylation, nuclear p65 translocation and binding activity in a dose dependent way (up to 10μg/ml). Accordingly, the same BA-doses inhibited the expression of pro-inflammatory and NFκB regulated genes as MCP-1 and RANTES, but did not affect expression of genes not related to NFκB signaling. In addition to the effect on activated HSC, BA inhibited the in vitro activation process of freshly isolated HSC as evidenced by delayed expression of collagen I and α-SMA mRNA and protein. Together, these findings indicate that BA inhibit NFκB activation, and herewith the activation and development of profibrogenic phenotype of HSC. Thus, bitter acids appear as potential functional nutrients for the prevention or treatment hepatic fibrosis in chronic liver disease.

  18. RADIAL ANGULAR MOMENTUM TRANSFER AND MAGNETIC BARRIER FOR SHORT-TYPE GAMMA-RAY-BURST CENTRAL ENGINE ACTIVITY

    SciTech Connect

    Liu Tong; Gu Weimin; Hou Shujin; Liang Enwei; Lei Weihua; Lin Lin; Zhang Shuangnan; Dai Zigao

    2012-11-20

    Soft extended emission (EE) following initial hard spikes up to 100 s was observed with Swift/BAT for about half of known short-type gamma-ray bursts (SGRBs). This challenges the conversional central engine models of SGRBs, i.e., compact star merger models. In the framework of black-hole-neutron-star merger models, we study the roles of radial angular momentum transfer in the disk and the magnetic barrier around the black hole in the activity of SGRB central engines. We show that radial angular momentum transfer may significantly prolong the lifetime of the accretion process, which may be divided into multiple episodes by the magnetic barrier. Our numerical calculations based on models of neutrino-dominated accretion flows suggest that disk mass is critical for producing the observed EE. In the case of the mass being {approx}0.8 M {sub Sun }, our model can reproduce the observed timescale and luminosity of both the main and the EE episodes in a reasonable parameter set. The predicted luminosity of the EE component is lower than the observed EE within about one order of magnitude and the timescale is shorter than 20 s if the disk mass is {approx}0.2 M {sub Sun }. Swift/BAT-like instruments may be not sensitive enough to detect the EE component in this case. We argue that the EE component could be a probe for the merger process and disk formation for compact star mergers.

  19. Activating PKC-β1 at the blood-brain barrier reverses induction of P-glycoprotein activity by dioxin and restores drug delivery to the CNS.

    PubMed

    Wang, Xueqian; Hawkins, Brian T; Miller, David S

    2011-06-01

    Upregulation of blood-brain barrier (BBB) P-glycoprotein expression causes central nervous system (CNS) pharmacoresistance. However, activation of BBB protein kinase C-β1 (PKC-β1) rapidly reduces basal P-glycoprotein transport activity. We tested whether PKC-β1 activation would reverse CNS drug resistance caused by dioxin acting through aryl hydrocarbon receptor. A selective PKC-β1 agonist abolished the increase in P-glycoprotein activity induced by dioxin in isolated rat brain capillaries and reversed the effect of dioxin on brain uptake of verapamil in dioxin-dosed rats. Thus, targeting BBB PKC-β1 may be an effective strategy to improve drug delivery to the brain, even in drug-resistant individuals.

  20. Local variation in herbivore feeding activity on an inshore reef of the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Cvitanovic, C.; Bellwood, D. R.

    2009-03-01

    Threats to coral reefs may be manifested through an increase in macroalgae. Across the globe, phase-shifts from coral to macroalgal dominance have been reported from the Caribbean, Indian and Pacific Oceans. While the Great Barrier Reef (GBR) is in relatively good condition, inshore reefs may exhibit over 50% macroalgal cover. However, our understanding of the processes preventing the macroalgal expansion remains uncertain. Using a remote video bioassay approach, this study quantified herbivory in three bays along the leeward margin of Orpheus Island. Despite significant with-in bay variation in herbivory there was no detectable statistical difference in the rates of herbivory among bays. Furthermore, of the 45 herbivore species recorded from the island, only three played a significant role in bioassay removal, Siganus canaliculatus, Siganus javus and Kyphosus vaigiensis, with only one species predominating in each bay. Reefs of the GBR may therefore be more vulnerable than previously thought, with the removal of macroalgae depending on just a few species, which exhibit considerable spatial variability in their feeding behaviour.

  1. Active species delivered by dielectric barrier discharge filaments to bacteria biofilms on the surface of apple

    NASA Astrophysics Data System (ADS)

    Cheng, He; Liu, Xin; Lu, Xinpei; Liu, Dawei

    2016-07-01

    The atmospheric pressure non-equilibrium plasma has shown a significant potential as a novel food decontamination technology. In this paper, we report a computational study of the intersection of negative streamer produced by air dielectric barrier discharge with bacteria biofilm on an apple surface. The structure, conductivities, and permittivities of bacteria biofilm have been considered in the Poisson's equations and transportation equations of charge and neutral species to realize self-consistent transportation of plasma between electrode and charging surfaces of apple. We find that the ionization near the biofilm facilitates the propagation of negative streamer when the streamer head is 1 mm from the biofilm. The structure of the biofilm results in the non-uniform distribution of ROS and RNS captured by flux and time fluence of these reactive species. The mean free path of charged species in μm scale permitted the plasma penetrate into the cavity of the biofilm, therefore, although the density of ROS and RNS decrease by 6-7 order of magnitude, the diffusion results in the uniform distribution of ROS and RNS inside the cavity during the pulse off period.

  2. Plasmachemical and heterogeneous processes in ozonizers with oxygen activation by a dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Mankelevich, Yu. A.; Voronina, E. N.; Poroykov, A. Yu.; Rakhimov, T. V.; Voloshin, D. G.; Chukalovsky, A. A.

    2016-10-01

    Plasmachemical and heterogeneous processes of generation and loss of ozone in the atmosphericpressure dielectric barrier discharge in oxygen are studied theoretically. Plasmachemical and electronic kinetics in the stage of development and decay of a single plasma filament (microdischarge) are calculated numerically with and without allowance for the effects of ozone vibrational excitation and high initial ozone concentration. The developed analytical approach is applied to determine the output ozone concentration taking into account ozone heterogeneous losses on the Al2O3 dielectric surface. Using the results of quantummechanical calculations by the method of density functional theory, a multistage catalytic mechanism of heterogeneous ozone loss based on the initial passivation of a pure Al2O3 surface by ozone and the subsequent interaction of O3 molecules with the passivated surface is proposed. It is shown that the conversion reaction 2O3 → 3O2 of a gas-phase ozone molecule with a physically adsorbed ozone molecule can result in the saturation of the maximum achievable ozone concentration at high specific energy depositions, the nonstationarity of the output ozone concentration, and its dependence on the prehistory of ozonizer operation.

  3. Matrix metalloproteinase 13 modulates intestinal epithelial barrier integrity in inflammatory diseases by activating TNF

    PubMed Central

    Vandenbroucke, Roosmarijn E; Dejonckheere, Eline; Van Hauwermeiren, Filip; Lodens, Sofie; De Rycke, Riet; Van Wonterghem, Elien; Staes, An; Gevaert, Kris; López-Otin, Carlos; Libert, Claude

    2013-01-01

    Several pathological processes, such as sepsis and inflammatory bowel disease (IBD), are associated with impairment of intestinal epithelial barrier. Here, we investigated the role of matrix metalloproteinase MMP13 in these diseases. We observed that MMP13−/− mice display a strong protection in LPS- and caecal ligation and puncture-induced sepsis. We could attribute this protection to reduced LPS-induced goblet cell depletion, endoplasmic reticulum stress, permeability and tight junction destabilization in the gut of MMP13−/− mice compared to MMP13+/+ mice. Both in vitro and in vivo, we found that MMP13 is able to cleave pro-TNF into bioactive TNF. By LC-MS/MS, we identified three MMP13 cleavage sites, which proves that MMP13 is an alternative TNF sheddase next to the TNF converting enzyme TACE. Similarly, we found that the same mechanism was responsible for the observed protection of the MMP13−/− mice in a mouse model of DSS-induced colitis. We identified MMP13 as an important mediator in sepsis and IBD via the shedding of TNF. Hence, we propose MMP13 as a novel drug target for diseases in which damage to the gut is essential. PMID:23723167

  4. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation

    PubMed Central

    Zelle, Dorien M.; Corpeleijn, Eva; Klaassen, Gerald; Schutte, Elise; Navis, Gerjan; Bakker, Stephan J. L.

    2016-01-01

    Background Physical activity (PA) and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal transplant recipients (RTR) meet the PA guidelines. Identification of barriers to regular PA is important to identify targets for intervention to improve PA levels after renal transplantation. We investigated fear of movement and physical self-efficacy as barriers to PA in RTR. Methods RTR were investigated between 2001–2003. The Tampa Score of Kinesiophobia–Dutch Version (TSK-11) was used to assess fear of movement. Physical self-efficacy was measured with the LIVAS-scale. PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire). Results A total of 487 RTR (age 51±12 years, 55% men) were studied. Median score [interquartile range] on TSK-11 was 22 [17–26]. Low physical self-efficacy (Exp B:0.41[0.31–0.54], p<0.001) and history of myocardial infarction, transient ischemic attack and cerebrovascular accident (Exp B:1.30[1.03–1.63],p = 0.03) were independent determinants for fear of movement. Fear of movement was associated with lower daily PA, occupational, sports and leisure time PA. Mediation-analysis showed that a large part (73%) of the effect of fear of movement on PA was explained by low physical self-efficacy. Conclusions This study was the first to examine fear of movement and self-efficacy in relation to PA in RTR. Fear of movement was associated with a low PA level, and the larger part of this relation was mediated by low physical self-efficacy. Both fear of movement and physical self-efficacy level are important targets for intervention during rehabilitation after renal transplantation. PMID:26844883

  5. Intersoliton hopping transport of electrons in molecular crystals

    NASA Astrophysics Data System (ADS)

    Howard, I. A.; Conwell, E. M.

    1984-06-01

    Quarter-filled-band quasi-one-dimensional compounds which exhibit large Coulomb repulsion between two electrons on the same site ("large U") can support the formation of fractionally charged solitons. Electron hopping between solitons may contribute substantially to transport in these materials. We calculate the intersoliton electron hopping rate for transitions mediated by intramolecular phonons and by acoustic phonons. Acoustic phonons are found to be much less effective and are expected to contribute significantly only when intramolecular phonons are not excited or cannot satisfy conservation of energy. For the case of intramolecular phonons, we consider both hopping of an electron from a soliton pinned by an impurity to a second soliton which then becomes pinned, and hopping between a pair of solitons, one of which remains free to move. [Owing to the large on-chain dielectric constant (~ 100-1000) in these materials, the solitons are probably not bound except at low temperatures.] The transition rates are used to find the hopping mobility for electrons in the soliton levels. Evaluation of the mobility due to the different hopping mechanisms for (N-methylphenazinium)0.54(phenazine)0.46 tetracyanoquinodimethane [(NMP)0.54(Phen)0.46-(TCNQ)] at a temperature of 100 K suggests that, unlike the polyacetylene case, the predominant process at temperatures >~100 K is on-chain hopping, due to the large interchain distances involved. We find a mobility at 100 K of 0.06-1.03 cm2/V sec due to on-chain hopping, mediated by intramolecular phonons, between pinned and free solitons. This mobility should increase at higher temperatures. The thermoelectric power due to the various electron hopping processes is calculated as well. We find that for hopping processes involving transitions between pinned and free solitons there is a term in the thermopower involving the soliton pinning energy, in addition to the usual term involving electronic energy levels.

  6. Two-legged hopping in autism spectrum disorders

    PubMed Central

    Moran, Matthew F.; Foley, John T.; Parker, Mary E.; Weiss, Michael J.

    2013-01-01

    Sensory processing deficits are common within autism spectrum disorders (ASD). Deficits have a heterogeneous dispersion across the spectrum and multimodal processing tasks are thought to magnify integration difficulties. Two-legged hopping in place in sync with an auditory cue (2.3, 3.0 Hz) was studied in a group of six individuals with expressive language impaired ASD (ELI-ASD) and an age-matched control group. Vertical ground reaction force data were collected and discrete Fourier transforms were utilized to determine dominant hopping cadence. Effective leg stiffness was computed through a mass-spring model representation. The ELI-ASD group were unsuccessful in matching their hopping cadence (2.21 ± 0.30 hops·s−1, 2.35 ± 0.41 hops·s−1) to either auditory cue with greater deviations at the 3.0 Hz cue. In contrast, the control group was able to match hopping cadence (2.35 ± 0.06 hops·s−1, 3.02 ± 0.10 hops·s−1) to either cue via an adjustment of effective leg stiffness. The ELI-ASD group demonstrated a varied response with an interquartile range (IQR) in excess of 0.5 hops·s−1 as compared to the control group with an IQR < 0.03 hops·s−1. Several sensorimotor mechanisms could explain the inability of participants with ELI-ASD to modulate motor output to match an external auditory cue. These results suggest that a multimodal gross motor task can (1) discriminate performance among a group of individuals with severe autism, and (2) could be a useful quantitative tool for evaluating motor performance in individuals with ASD individuals. PMID:23532337

  7. Hip Hop Culture's OGs: A Narrative Inquiry into the Intersection of Hip Hop Culture, Black Males and Their Schooling Experiences

    ERIC Educational Resources Information Center

    Buchanan, Ian P.

    2013-01-01

    Using a critical race lens, this narrative study employs a focus group design to explore the intersections between black males, hip hop culture and schooling experiences. To provide a sociocultural grounding, this study first reviews the research literature around hip hop culture.s sociocultural development and its impact as a culture force that…

  8. Hip-Hop Is My Passport! Using Hip-Hop and Digital Literacies to Understand Global Citizenship Education

    ERIC Educational Resources Information Center

    Horton, Akesha Monique

    2013-01-01

    Hip-hop has exploded around the world among youth. It is not simply an American source of entertainment; it is a global cultural movement that provides a voice for youth worldwide who have not been able to express their "cultural world" through mainstream media. The emerging field of critical hip-hop pedagogy has produced little…

  9. Identifying Barriers, Perceptions and Motivations Related to Healthy Eating and Physical Activity among 6th to 8th Grade, Rural, Limited-Resource Adolescents

    ERIC Educational Resources Information Center

    Kumar, Janavi; Adhikari, Koushik; Li, Yijing; Lindshield, Erika; Muturi, Nancy; Kidd, Tandalayo

    2016-01-01

    Purpose: The purpose of this paper is to enable community members to discuss their perceptions of eating habits and physical activity in relation to sixth, seventh, and eighth graders, and reveal facilitators and barriers to healthy eating behavior and physical activity engagement. Design/methodology/approach: Nine focus groups, which included six…

  10. Generalized trajectory surface-hopping method for internal conversion and intersystem crossing.

    PubMed

    Cui, Ganglong; Thiel, Walter

    2014-09-28

    Trajectory-based fewest-switches surface-hopping (FSSH) dynamics simulations have become a popular and reliable theoretical tool to simulate nonadiabatic photophysical and photochemical processes. Most available FSSH methods model internal conversion. We present a generalized trajectory surface-hopping (GTSH) method for simulating both internal conversion and intersystem crossing processes on an equal footing. We consider hops between adiabatic eigenstates of the non-relativistic electronic Hamiltonian (pure spin states), which is appropriate for sufficiently small spin-orbit coupling. This choice allows us to make maximum use of existing electronic structure programs and to minimize the changes to available implementations of the traditional FSSH method. The GTSH method is formulated within the quantum mechanics (QM)/molecular mechanics framework, but can of course also be applied at the pure QM level. The algorithm implemented in the GTSH code is specified step by step. As an initial GTSH application, we report simulations of the nonadiabatic processes in the lowest four electronic states (S0, S1, T1, and T2) of acrolein both in vacuo and in acetonitrile solution, in which the acrolein molecule is treated at the ab initio complete-active-space self-consistent-field level. These dynamics simulations provide detailed mechanistic insight by identifying and characterizing two nonadiabatic routes to the lowest triplet state, namely, direct S1 → T1 hopping as major pathway and sequential S1 → T2 → T1 hopping as minor pathway, with the T2 state acting as a relay state. They illustrate the potential of the GTSH approach to explore photoinduced processes in complex systems, in which intersystem crossing plays an important role.

  11. Real-Time On-Board Airborne Demonstration of High-Speed On-Board Data Processing for Science Instruments (HOPS)

    NASA Technical Reports Server (NTRS)

    Beyon, Jeffrey Y.; Ng, Tak-Kwong; Davis, Mitchell J.; Adams, James K.; Bowen, Stephen C.; Fay, James J.; Hutchinson, Mark A.

    2015-01-01

    The project called High-Speed On-Board Data Processing for Science Instruments (HOPS) has been funded by NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) program since April, 2012. The HOPS team recently completed two flight campaigns during the summer of 2014 on two different aircrafts with two different science instruments. The first flight campaign was in July, 2014 based at NASA Langley Research Center (LaRC) in Hampton, VA on the NASA's HU-25 aircraft. The science instrument that flew with HOPS was Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) CarbonHawk Experiment Simulator (ACES) funded by NASA's Instrument Incubator Program (IIP). The second campaign was in August, 2014 based at NASA Armstrong Flight Research Center (AFRC) in Palmdale, CA on the NASA's DC-8 aircraft. HOPS flew with the Multifunctional Fiber Laser Lidar (MFLL) instrument developed by Excelis Inc. The goal of the campaigns was to perform an end-to-end demonstration of the capabilities of the HOPS prototype system (HOPS COTS) while running the most computationally intensive part of the ASCENDS algorithm real-time on-board. The comparison of the two flight campaigns and the results of the functionality tests of the HOPS COTS are presented in this paper.

  12. Genetic Interactions between Hop1, Red1 and Mek1 Suggest That Mek1 Regulates Assembly of Axial Element Components during Meiosis in the Yeast Saccharomyces Cerevisiae

    PubMed Central

    Hollingsworth, N. M.; Ponte, L.

    1997-01-01

    During meiosis, axial elements are generated by the condensation of sister chromatids along a protein core as precursors to the formation of the synaptonemal complex (SC). Functional axial elements are essential for wild-type levels of recombination and proper reductional segregation at meiosis I. Genetic and cytological data suggest that three meiosis-specific genes, HOP1, RED1 and MEK1, are involved in axial element formation in the yeast Saccharomyces cerevisiae. HOP1 and RED1 encode structural components of axial elements while MEK1 encodes a putative protein kinase. Using a partially functional allele of MEK1, new genetic interactions have been found between HOP1, RED1 and MEK1. Overexpression of HOP1 partially suppresses the spore inviability and recombination defects of mek1-974; in contrast, overexpression of RED1 exacerbates the mek1-974 spore inviability. Co-overexpression of HOP1 and RED1 in mek1-974 diploids alleviates the negative effect of overexpressing RED1 alone. Red1p/Red1p as well as Hop1p/Red1p interactions have been reconstituted in two hybrid experiments. Our results suggest a model whereby Mek1 kinase activity controls axial element assembly by regulating the affinity with which Hop1p and Red1p interact with each other. PMID:9286666

  13. Jahn-Teller assisted polaronic hole hopping as a charge transport mechanism in CuO nanograins

    NASA Astrophysics Data System (ADS)

    Younas, M.; Nadeem, M.; Idrees, M.; Akhtar, M. J.

    2012-04-01

    Impedance spectroscopy has been employed to investigate the dielectric and electric transport phenomena in sol-gel synthesized CuO nanograins. Semiconducting features of the grains and grain boundaries have been endorsed to the thermal activation of the localized charge carriers. On cooling below 303 K, a transition from Jahn-Teller polaron hopping mechanism to the Mott's variable range hopping mechanism has been observed owing to random potential fluctuations among localized sites. Activation energies for conduction and relaxation processes at grain boundaries provide strong signatures for the involvement of Jahn-Teller adiabatic small polarons as a charge transport mechanism in CuO nanograins.

  14. Transport of hop aroma compounds across Caco-2 monolayers.

    PubMed

    Heinlein, A; Metzger, M; Walles, H; Buettner, A

    2014-11-01

    Although being reported and used as a sedative remedy for several years, the bioactive principle of hop preparations is still not decisively clarified. Understanding absorption and transformation processes of potential physiologically active constituents is essential to evaluate the likeliness of biological effects on humans. Therefore, single hop aroma compounds as well as digestive transformation products thereof have been investigated in view of their human intestinal absorption, applying Caco-2 transport experiments as well as investigations on potential biotransformation processes. Selective and sensitive identification and quantification were thereby achieved by application of two-dimensional high resolution gas chromatography-mass spectrometry in conjunction with stable isotope dilution analysis, leading to the determination of apparent permeability values by different mathematical approaches considering sink and non-sink conditions. Overall, calculated permeability values ranged from 2.6 × 10(-6) to 1.8 × 10(-4) cm s(-1) with all mathematical approaches, indicating high absorption potential and almost complete bioavailability for all tested compounds with hydroxyl-functionalities. Considering this high permeability together with the high lipophilicity of these substances, a passive transcellular uptake route can be speculated. Investigated sesquiterpenes and β-myrcene showed flat absorption profiles while the investigated esters showed decreasing profiles. In view of the lipophilic and volatile nature of the investigated substances, special attention was paid to recovery and mass balance determination. Furthermore, in the course of the transport experiments of 1-octen-3-ol and 3-methyl-2-buten-1-ol, additional biotransformation products were observed, namely 3-octanone and 3-methyl-2-butenal, respectively. The absence of these additional substances in control experiments strongly indicates an intestinal first-pass metabolism of the

  15. Extended active space CASSCF/MRSD CI calculations of the barrier height for the reaction: O + H2 yields OH + H

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.

    1986-01-01

    The convergence of the barrier height for the O + H2 yields OH + H reaction was studied as a function of the size of the active space and basis set completeness. The barrier height is rapidly convergent with respect to expansion of the active space. Addition of 2p yields 2p' correlation terms to the active space lowers the barrier to the O + H2 reaction by about 2.0 kcal/mole, but addition of 3d and other terms has little additional effect. Multireference singles and doubles contracted CI plus Davidson's correction calculations using a (5s5p3d2f1g/4s3p2d1f) basis set with a 5 sigma 2 pi active space lead to a barrier height of 12.7 kcal/mole. Including an estimate of the CI contraction error and basis set superposition error leads to 12.4 kcal/mole as the best estimate of the barrier height.

  16. Extended active space CASSCF/MRSD CI calculations of the barrier height for the reaction O+H/sub 2/. -->. OH+H

    SciTech Connect

    Walch, S.P.

    1987-05-15

    The convergence of the barrier height for the O+H/sub 2/..-->..OH+H reaction has been studied as a function of the size of the active space and basis set completeness. The barrier height is rapidly convergent with respect to expansion of the active space. Addition of 2p..-->..2p' correlation terms to the active space lowers the barrier to the O+H/sub 2/ reaction by about 2.0 kcal/mol, but addition of 3d and other terms has little additional effect. Multireference singles and doubles contracted CI plus Davidson's correction calculations using a (5s5p3d2f1g/4s3p2d1f) basis set with a 5sigma2..pi.. active space lead to a barrier height of 12.7 kcal/mol. Including an estimate of the CI contraction error and basis set superposition error leads to 12.4 kcal/mol as the best estimate of the barrier height.

  17. Origin of activated combustion in steady-state premixed burner flame with superposition of dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Zaima, Kazunori; Akashi, Haruaki; Sasaki, Koichi

    2016-01-01

    The objective of this work is to understand the mechanism of plasma-assisted combustion in a steady-state premixed burner flame. We examined the spatiotemporal variation of the density of atomic oxygen in a premixed burner flame with the superposition of dielectric barrier discharge (DBD). We also measured the spatiotemporal variations of the optical emission intensities of Ar and OH. The experimental results reveal that atomic oxygen produced in the preheating zone by electron impact plays a key role in the activation of combustion reactions. This understanding is consistent with that described in our previous paper indicating that the production of “cold OH(A2Σ+)” via CHO + O → OH(A2Σ+) + CO has the sensitive response to the pulsed current of DBD [K. Zaima and K. Sasaki, Jpn. J. Appl. Phys. 53, 110309 (2014)].

  18. Mood after various brief exercise and sport modes: aerobics, hip-hop dancing, ice skating, and body conditioning.

    PubMed

    Kim, Sungwoon; Kim, Jingu

    2007-06-01

    To investigate the potential psychological benefits of brief exercise and sport activities on positive mood alterations, 45 Korean high school and 232 undergraduate students enrolled in physical education and stress management classes voluntarily participated and were randomly assigned to one of four activities: aerobic exercise, body conditioning, hip-hop dancing, and ice skating. Mood changes from before to after exercise (2 pm to 3 pm) were measured based on a Korean translation of the Subjective Exercise Experiences Scale. The findings suggested that the aerobics and hip-hop dancing groups rated positive well-being higher than the body conditioning and ice skating groups. Immediately after exercise, psychological distress was rated lower in the aerobics and hip-hop dancing groups, as was fatigue.

  19. Regulation to Create Environments Conducive to Physical Activity: Understanding the Barriers and Facilitators at the Australian State Government Level

    PubMed Central

    Shill, Jane; Mavoa, Helen; Crammond, Brad; Loff, Bebe; Peeters, Anna; Lawrence, Mark; Allender, Steven; Sacks, Gary; Swinburn, Boyd A.

    2012-01-01

    Introduction Policy and regulatory interventions aimed at creating environments more conducive to physical activity (PA) are an important component of strategies to improve population levels of PA. However, many potentially effective policies are not being broadly implemented. This study sought to identify potential policy/regulatory interventions targeting PA environments, and barriers/facilitators to their implementation at the Australian state/territory government level. Methods In-depth interviews were conducted with senior representatives from state/territory governments, statutory authorities and non-government organisations (n = 40) to examine participants': 1) suggestions for regulatory interventions to create environments more conducive to PA; 2) support for preselected regulatory interventions derived from a literature review. Thematic and constant comparative analyses were conducted. Results Policy interventions most commonly suggested by participants fell into two areas: 1) urban planning and provision of infrastructure to promote active travel; 2) discouraging the use of private motorised vehicles. Of the eleven preselected interventions presented to participants, interventions relating to walkability/cycling and PA facilities received greatest support. Interventions involving subsidisation (of public transport, PA-equipment) and the provision of more public transport infrastructure received least support. These were perceived as not economically viable or unlikely to increase PA levels. Dominant barriers were: the powerful ‘road lobby’, weaknesses in the planning system and the cost of potential interventions. Facilitators were: the provision of evidence, collaboration across sectors, and synergies with climate change/environment agendas. Conclusion This study points to how difficult it will be to achieve policy change when there is a powerful ‘road lobby’ and government investment prioritises road infrastructure over PA

  20. Phenotypic changes in colonocytes following acute stress or activation of mast cells in mice: implications for delayed epithelial barrier dysfunction

    PubMed Central

    Demaude, J; Salvador‐Cartier, C; Fioramonti, J; Ferrier, L; Bueno, L

    2006-01-01

    Background and aim Stressful life events are known to modulate the development or relapse of disease in both inflammatory bowel disease and irritable bowel disease patients but underlying mechanisms remain unclear. Stress is known to effect mast cells, interferon γ (IFN‐γ), and myosin light chain phosphorylation to trigger colonic epithelial barrier dysfunction. The aim of this study was to investigate whether acute stress induced or chemical mast cell activation impaired expression and function of epithelial tight junctions, and altered colonocyte differentiation in mice. Methods Colonic paracellular permeability was assessed as the in vivo lumen to blood ratio of 51Cr‐EDTA in different groups of mice (controls, stressed, mast cell degranulator BrX‐537A treated), pretreated or not with the mast cell stabiliser doxantrazole. Involvement of mast cells and IFN‐γ was evaluated in wild‐type and IFN‐γ deficient mice. Tight junction alteration was assessed by histology, transmission electron microscopy, and real time reverse transcription‐polymerase chain reaction. Colonocyte differentiation was determined by protein kinase C ζ (PKCζ) immunofluorescence and western blotting, and alkaline phosphatase activity assay. Results Acute stress induced a three day delayed increase in colonic paracellular permeability which involved mast cell degranulation and overproduction of IFN‐γ. The colonic epithelial barrier was morphologically altered and expression of mRNA encoding tight junction proteins ZO‐2 and occludin was decreased. Moreover, three days after acute stress, colonocyte differentiation was reduced, as shown by decreased expression of both PKCζ isotype and alkaline phosphatase. Conclusion These data highlight new mechanisms whereby an acute stress acts on the gastrointestinal tract by inducing alterations in colonocyte differentiation and decreased expression of mRNA encoding tight junction proteins. Thus phenotypic changes in colonocytes could

  1. Effect of tannic acid-fish scale gelatin hydrolysate hybrid nanoparticles on intestinal barrier function and α-amylase activity.

    PubMed

    Wu, Shao-Jung; Ho, Yi-Cheng; Jiang, Shun-Zhou; Mi, Fwu-Long

    2015-07-01

    Practical application of tannic acid is limited because it readily binds proteins to form insoluble aggregates. In this study, tannic acid was self-assembled with fish scale gelatin hydrolysates (FSGH) to form stable colloidal complex nanoparticles. The nanoparticles prepared from 4 mg ml(-1) tannic acid and 4 mg ml(-1) FSGH had a mean particle size of 260.8 ± 3.6 nm, and showed a positive zeta potential (20.4 ± 0.4 mV). The nanoparticles acted as effective nano-biochelators and free radical scavengers because they provided a large number of adsorption sites for interaction with heavy metal ions and scavenging free radicals. The maximum adsorption capacity for Cu(2+) ions was 123.5 mg g(-1) and EC50 of DPPH radical scavenging activity was 21.6 ± 1.2 μg ml(-1). Hydroxyl radical scavenging effects of the nanoparticles were investigated by electron spin resonance spectroscopy. The copper-chelating capacity and free radical scavenging activity of the nanoparticles were associated with their capacity to inhibit Cu(2+) ion-induced barrier impairment and hyperpermeability of Caco-2 intestinal epithelial tight junction (TJ). However, α-amylase inhibitory activity of the nanoparticles was significantly lower than that of free tannic acid. The results suggest that the nanoparticles can ameliorate Cu(2+) ion induced intestinal epithelial TJ dysfunction without severely inhibiting the activity of the digestive enzymes.

  2. Resveratrol attenuates lipopolysaccharide-induced dysfunction of blood-brain barrier in endothelial cells via AMPK activation

    PubMed Central

    2016-01-01

    Resveratrol, a phytoalexin, is reported to activate AMP-activated protein kinase (AMPK) in vascular cells. The blood-brain barrier (BBB), formed by specialized brain endothelial cells that are interconnected by tight junctions, strictly regulates paracellular permeability to maintain an optimal extracellular environment for brain homeostasis. The aim of this study was to elucidate the effects of resveratrol and the role of AMPK in BBB dysfunction induced by lipopolysaccharide (LPS). Exposure of human brain microvascular endothelial cells (HBMECs) to LPS (1 µg/ml) for 4 to 24 hours week dramatically increased the permeability of the BBB in parallel with lowered expression levels of occluding and claudin-5, which are essential to maintain tight junctions in HBMECs. In addition, LPS significantly increased the reactive oxygen species (ROS) productions. All effects induced by LPS in HBVMCs were reversed by adenoviral overexpression of superoxide dismutase, inhibition of NAD(P) H oxidase by apocynin or gain-function of AMPK by adenoviral overexpression of constitutively active mutant (AMPK-CA) or by resveratrol. Finally, upregulation of AMPK by either AMPK-CA or resveratrol abolished the levels of LPS-enhanced NAD(P)H oxidase subunits protein expressions. We conclude that AMPK activation by resveratrol improves the integrity of the BBB disrupted by LPS through suppressing the induction of NAD(P)H oxidase-derived ROS in HBMECs. PMID:27382348

  3. Semiclassical nonadiabatic surface-hopping wave function expansion at low energies: hops in the forbidden region.

    PubMed

    Herman, Michael F

    2008-12-18

    The accuracy of a semiclassical surface-hopping expansion of the time-independent wave function for problems in which the nonadiabatic coupling is peaked in the classically forbidden regions is studied numerically for a one-dimensional curve-crossing problem. This surface-hopping expansion has recently been shown to satisfy the Schrodinger equation to all orders in h and all orders in the nonadiabatic coupling. It has also been found to provide very accurate transition probabilities for problems in which the crossing points of the diabatic energy surfaces are classically allowed. In the numerical study reported here, transition probabilities are evaluated for energies well below the crossing point energy. It is found that the expansion provides accurate results for transition probabilities as small as 10(-11).

  4. Communication devices for network-hopping communications and methods of network-hopping communications

    DOEpatents

    Buttles, John W [Idaho Falls, ID

    2011-12-20

    Wireless communication devices include a software-defined radio coupled to processing circuitry. The processing circuitry is configured to execute computer programming code. Storage media is coupled to the processing circuitry and includes computer programming code configured to cause the processing circuitry to configure and reconfigure the software-defined radio to operate on each of a plurality of communication networks according to a selected sequence. Methods for communicating with a wireless device and methods of wireless network-hopping are also disclosed.

  5. Communication devices for network-hopping communications and methods of network-hopping communications

    DOEpatents

    Buttles, John W

    2013-04-23

    Wireless communication devices include a software-defined radio coupled to processing circuitry. The system controller is configured to execute computer programming code. Storage media is coupled to the system controller and includes computer programming code configured to cause the system controller to configure and reconfigure the software-defined radio to operate on each of a plurality of communication networks according to a selected sequence. Methods for communicating with a wireless device and methods of wireless network-hopping are also disclosed.

  6. Ceramide 1-Phosphate Increases P-Glycoprotein Transport Activity at the Blood-Brain Barrier via Prostaglandin E2 Signaling.

    PubMed

    Mesev, Emily V; Miller, David S; Cannon, Ronald E

    2017-04-01

    P-glycoprotein, an ATP-driven efflux pump, regulates permeability of the blood-brain barrier (BBB). Sphingolipids, endogenous to brain tissue, influence inflammatory responses and cell survival in vitro. Our laboratory has previously shown that sphingolipid signaling by sphingosine 1-phosphate decreases basal P-glycoprotein transport activity. Here, we investigated the potential for another sphingolipid, ceramide 1-phosphate (C1P), to modulate efflux pumps at the BBB. Using confocal microscopy and measuring luminal accumulation of fluorescent substrates, we assessed the transport activity of several efflux pumps in isolated rat brain capillaries. C1P treatment induced P-glycoprotein transport activity in brain capillaries rapidly and reversibly. In contrast, C1P did not affect transport activity of two other major efflux transporters, multidrug resistance protein 2 and breast cancer resistance protein. C1P induced P-glycoprotein transport activity without changing transporter protein expression. Inhibition of the key signaling components in the cyclooxygenase-2 (COX-2)/prostaglandin E2 signaling cascade (phospholipase A2, COX-2, multidrug resistance protein 4, and G-protein-coupled prostaglandin E2 receptors 1 and 2), abolished P-glycoprotein induction by C1P. We show that COX-2 and prostaglandin E2 are required for C1P-mediated increases in P-glycoprotein activity independent of transporter protein expression. This work describes how C1P activates a signaling cascade to dynamically regulate P-glycoprotein transport at the BBB and offers potential clinical targets to modulate neuroprotection and drug delivery to the CNS.

  7. Ceramide 1-Phosphate Increases P-Glycoprotein Transport Activity at the Blood-Brain Barrier via Prostaglandin E2 Signaling

    PubMed Central

    Mesev, Emily V.; Miller, David S.

    2017-01-01

    P-glycoprotein, an ATP-driven efflux pump, regulates permeability of the blood-brain barrier (BBB). Sphingolipids, endogenous to brain tissue, influence inflammatory responses and cell survival in vitro. Our laboratory has previously shown that sphingolipid signaling by sphingosine 1-phosphate decreases basal P-glycoprotein transport activity. Here, we investigated the potential for another sphingolipid, ceramide 1-phosphate (C1P), to modulate efflux pumps at the BBB. Using confocal microscopy and measuring luminal accumulation of fluorescent substrates, we assessed the transport activity of several efflux pumps in isolated rat brain capillaries. C1P treatment induced P-glycoprotein transport activity in brain capillaries rapidly and reversibly. In contrast, C1P did not affect transport activity of two other major efflux transporters, multidrug resistance protein 2 and breast cancer resistance protein. C1P induced P-glycoprotein transport activity without changing transporter protein expression. Inhibition of the key signaling components in the cyclooxygenase-2 (COX-2)/prostaglandin E2 signaling cascade (phospholipase A2, COX-2, multidrug resistance protein 4, and G-protein–coupled prostaglandin E2 receptors 1 and 2), abolished P-glycoprotein induction by C1P. We show that COX-2 and prostaglandin E2 are required for C1P-mediated increases in P-glycoprotein activity independent of transporter protein expression. This work describes how C1P activates a signaling cascade to dynamically regulate P-glycoprotein transport at the BBB and offers potential clinical targets to modulate neuroprotection and drug delivery to the CNS. PMID:28119480

  8. Fewest Switches Surface Hopping in Liouville Space.

    PubMed

    Wang, Linjun; Sifain, Andrew E; Prezhdo, Oleg V

    2015-10-01

    The novel approach to nonadiabatic quantum dynamics greatly increases the accuracy of the most popular semiclassical technique while maintaining its simplicity and efficiency. Unlike the standard Tully surface hopping in Hilbert space, which deals with population flow, the new strategy in Liouville space puts population and coherence on equal footing. Dual avoided crossing and energy transfer models show that the accuracy is improved in both diabatic and adiabatic representations and that Liouville space simulation converges faster with the number of trajectories than Hilbert space simulation. The constructed master equation accurately captures superexchange, tunneling, and quantum interference. These effects are essential for charge, phonon and energy transport and scattering, exciton fission and fusion, quantum optics and computing, and many other areas of physics and chemistry.

  9. Resistance distribution in the hopping percolation model.

    PubMed

    Strelniker, Yakov M; Havlin, Shlomo; Berkovits, Richard; Frydman, Aviad

    2005-07-01

    We study the distribution function P (rho) of the effective resistance rho in two- and three-dimensional random resistor networks of linear size L in the hopping percolation model. In this model each bond has a conductivity taken from an exponential form sigma proportional to exp (-kappar) , where kappa is a measure of disorder and r is a random number, 0< or = r < or =1 . We find that in both the usual strong-disorder regime L/ kappa(nu) >1 (not sensitive to removal of any single bond) and the extreme-disorder regime L/ kappa(nu) <1 (very sensitive to such a removal) the distribution depends only on L/kappa(nu) and can be well approximated by a log-normal function with dispersion b kappa(nu) /L , where b is a coefficient which depends on the type of lattice, and nu is the correlation critical exponent.

  10. Simple diffusion hopping model with convection

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Barry W.; Padding, Johan T.; van Santen, Rutger

    2017-01-01

    We present results from a new variant of a diffusion hopping model, the convective diffusive lattice model, to describe the behavior of a particulate flux around bluff obstacles. Particle interactions are constrained to an underlying square lattice where particles are subject to excluded volume conditions. In an extension to previous models, we impose a real continuous velocity field upon the lattice such that particles have an associated velocity vector. We use this velocity field to mediate the position update of the particles through the use of a convective update after which particles also undergo diffusion. We demonstrate the emergence of an expected wake behind a square obstacle which increases in size with increasing object size. For larger objects we observe the presence of recirculation zones marked by the presence of symmetric vortices in qualitative agreement with experiment and previous simulations.

  11. Grand and Semigrand Canonical Basin-Hopping

    PubMed Central

    2015-01-01

    We introduce grand and semigrand canonical global optimization approaches using basin-hopping with an acceptance criterion based on the local contribution of each potential energy minimum to the (semi)grand potential. The method is tested using local harmonic vibrational densities of states for atomic clusters as a function of temperature and chemical potential. The predicted global minima switch from dissociated states to clusters for larger values of the chemical potential and lower temperatures, in agreement with the predictions of a model fitted to heat capacity data for selected clusters. Semigrand canonical optimization allows us to identify particularly stable compositions in multicomponent nanoalloys as a function of increasing temperature, whereas the grand canonical potential can produce a useful survey of favorable structures as a byproduct of the global optimization search. PMID:26669731

  12. Particle hopping vs. fluid-dynamical models for traffic flow

    SciTech Connect

    Nagel, K.

    1995-12-31

    Although particle hopping models have been introduced into traffic science in the 19509, their systematic use has only started recently. Two reasons for this are, that they are advantageous on modem computers, and that recent theoretical developments allow analytical understanding of their properties and therefore more confidence for their use. In principle, particle hopping models fit between microscopic models for driving and fluiddynamical models for traffic flow. In this sense, they also help closing the conceptual gap between these two. This paper shows connections between particle hopping models and traffic flow theory. It shows that the hydrodynamical limits of certain particle hopping models correspond to the Lighthill-Whitham theory for traffic flow, and that only slightly more complex particle hopping models produce already the correct traffic jam dynamics, consistent with recent fluid-dynamical models for traffic flow. By doing so, this paper establishes that, on the macroscopic level, particle hopping models are at least as good as fluid-dynamical models. Yet, particle hopping models have at least two advantages over fluid-dynamical models: they straightforwardly allow microscopic simulations, and they include stochasticity.

  13. Power-Hop: A Pervasive Observation for Real Complex Networks

    PubMed Central

    Papalexakis, Evangelos; Hooi, Bryan; Pelechrinis, Konstantinos; Faloutsos, Christos

    2016-01-01

    Complex networks have been shown to exhibit universal properties, with one of the most consistent patterns being the scale-free degree distribution, but are there regularities obeyed by the r-hop neighborhood in real networks? We answer this question by identifying another power-law pattern that describes the relationship between the fractions of node pairs C(r) within r hops and the hop count r. This scale-free distribution is pervasive and describes a large variety of networks, ranging from social and urban to technological and biological networks. In particular, inspired by the definition of the fractal correlation dimension D2 on a point-set, we consider the hop-count r to be the underlying distance metric between two vertices of the network, and we examine the scaling of C(r) with r. We find that this relationship follows a power-law in real networks within the range 2 ≤ r ≤ d, where d is the effective diameter of the network, that is, the 90-th percentile distance. We term this relationship as power-hop and the corresponding power-law exponent as power-hop exponent h. We provide theoretical justification for this pattern under successful existing network models, while we analyze a large set of real and synthetic network datasets and we show the pervasiveness of the power-hop. PMID:26974560

  14. Activation of epidermal toll-like receptor 2 enhances tight junction function – Implications for atopic dermatitis and skin barrier repair

    PubMed Central

    Kuo, I-Hsin; Carpenter-Mendini, Amanda; Yoshida, Takeshi; McGirt, Laura Y.; Ivanov, Andrei I.; Barnes, Kathleen C.; Gallo, Richard L.; Borkowski, Andrew W.; Yamasaki, Kenshi; Leung, Donald Y.; Georas, Steve N.; De Benedetto, Anna; Beck, Lisa A.

    2012-01-01

    Atopic dermatitis (AD) is characterized by epidermal tight junction (TJ) defects and a propensity for Staphylococcus aureus (S. aureus) skin infections. S. aureus is sensed by many pattern recognition receptors including toll-like receptor (TLR) 2. We hypothesized that an effective innate immune response will include skin barrier repair and that this response is impaired in AD subjects. S. aureus-derived peptidoglycan (PGN) and synthetic TLR2 agonists enhanced TJ barrier and increased expression of TJ proteins, CLDN1, CLDN23, occludin and ZO-1 in primary human keratinocytes. A TLR2 agonist enhanced skin barrier recovery in human epidermis wounded by tape-stripping. Tlr2−/− mice had a delayed and incomplete barrier recovery following tape-stripping. AD subjects had reduced epidermal TLR2 expression as compared to nonatopic (NA) subjects, which inversely correlated (r= 0.654, P= 0.0004) with transepidermal water loss (TEWL). These observations indicate that TLR2 activation enhances skin barrier in murine and human skin and is an important part of a wound repair response. Reduced epidermal TLR2 expression observed in AD patients may play a role in their incompetent skin barrier. PMID:23223142

  15. Historical changes in the Mississippi-Alabama barrier-island chain and the roles of extreme storms, sea level, and human activities

    USGS Publications Warehouse

    Morton, R.A.

    2008-01-01

    Barrier-island chains worldwide are undergoing substantial changes, and their futures remain uncertain. An historical analysis of a barrier-island chain in the north-central Gulf of Mexico shows that the Mississippi barriers are undergoing rapid systematic land loss and translocation associated with: (1) unequal lateral transfer of sand related to greater updrift erosion compared to downdrift deposition; (2) barrier narrowing resulting from simultaneous erosion of shores along the Gulf and Mississippi Sound; and (3) barrier segmentation related to storm breaching. Dauphin Island, Alabama, is also losing land for some of the same reasons as it gradually migrates landward. The principal causes of land loss are frequent intense storms, a relative rise in sea level, and a sediment-budget deficit. Considering the predicted trends for storms and sea level related to global warming, it is certain that the Mississippi-Alabama (MS-AL) barrier islands will continue to lose land area at a rapid rate unless the trend of at least one causal factor reverses. Historical land-loss trends and engineering records show that progressive increases in land-loss rate correlate with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. This correlation indicates that channel-maintenance activities along the MS-AL barriers have impacted the sediment budget by disrupting the alongshore sediment transport system and progressively reducing sand supply. Direct management of this causal factor can be accomplished by strategically placing dredged sediment where adjacent barrier-island shores will receive it for island nourishment and rebuilding.

  16. Antimicrobial activity of Enterococcus faecium L50, a strain producing enterocins L50 (L50A and L50B), P and Q, against beer-spoilage lactic acid bacteria in broth, wort (hopped and unhopped), and alcoholic and non-alcoholic lager beers.

    PubMed

    Basanta, Antonio; Sánchez, Jorge; Gómez-Sala, Beatriz; Herranz, Carmen; Hernández, Pablo E; Cintas, Luis M

    2008-07-31

    Enterococcus faecium L50 produces enterocin L50 (L50A and L50B) (EntL50, EntL50A and EntL50B), enterocin P (EntP) and enterocin Q (EntQ) and displays a broad antimicrobial spectrum against the most relevant beer-spoilage lactic acid bacteria (LAB) (i.e., Lactobacillus brevis and Pediococcus damnosus), which is mainly due to the production of EntL50 (EntL50A and EntL50B). Bacteriocin assays using in vitro-synthesized EntL50 (EntL50A and EntL50B) showed that both individual peptides possess antimicrobial activity on their own, EntL50A being the most active, but when the two peptides were combined a synergistic effect was observed. The only virulence genes detected in E. faecium L50 were efaAfm (cell wall adhesin) and ccf (sex pheromone), and this strain was susceptible to most clinically relevant antibiotics. E. faecium L50 survived but did not grow nor showed antimicrobial activity in hopped and unhopped wort, and alcoholic (1 and 5% ethanol, v/v) and non-alcoholic (0% ethanol, v/v) commercial lager beers. However, when unhopped wort was supplemented with 50% (v/v) MRS broth, E. faecium L50 grew and exerted antimicrobial activity similarly as in MRS broth. The enterocins produced by this strain were bactericidal (5 log decrease) against P. damnosus and Lb. brevis in a dose- and substrate-dependent manner when challenged in MRS broth, wort (hopped and unhopped), and alcoholic (1 and 5% ethanol, v/v) and non-alcoholic (0% ethanol, v/v) lager beers at 32 degrees C, and no bacterial resistances were detected even after incubation for 6-15 days. The enterocins in wort and lager beer (5% ethanol, v/v) withstood the heat treatments commonly employed in the brewing industry during mashing, wort boiling, fermentation, and pasteurization, and retained most of their antimicrobial activity in lager beer (5% ethanol, v/v) after long-term storage at 8 and 25 degrees C.

  17. Motivators and barriers to engaging in healthy eating and physical activity in young adult men

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Internationally, young men (aged 18-25 years) have a high prevalence of overweight and obesity and many fail to meet recommended levels of physical activity or dietary guidelines. There is a lack of engagement and understanding of young men's needs in health-related research. Therefore, this study a...

  18. Motivators and barriers to engaging in healthy eating and physical activity in young adult men

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The most recent Australian Health survey identified that young men (18-24yrs) have numerous health concerns including: 42% overweight/obese, 48% not meeting national physical activity recommendations and 97% failing to consume adequate intakes of fruit and vegetables. There is a lack of engagement a...

  19. Outdoor Built Environment Barriers and Facilitators to Activity among Midlife and Older Adults with Mobility Disabilities

    ERIC Educational Resources Information Center

    Rosenberg, Dori E.; Huang, Deborah L.; Simonovich, Shannon D.; Belza, Basia

    2013-01-01

    Purpose: To gain better understanding of how the built environment impacts neighborhood-based physical activity among midlife and older adults with mobility disabilities. Design and methods: We conducted in-depth interviews with 35 adults over age 50, which used an assistive device and lived in King County, Washington, U.S. In addition,…

  20. Male Gender Role Strain as a Barrier to African American Men's Physical Activity

    ERIC Educational Resources Information Center

    Griffith, Derek M.; Gunter, Katie; Allen, Julie Ober

    2011-01-01

    Despite the potential health consequences, African American men tend to treat their roles as providers, fathers, spouses, and community members as more important than engaging in health behaviors such as physical activity. We conducted 14 exploratory focus groups with 105 urban, middle-aged African American men from the Midwest to examine factors…

  1. Barriers to Increasing the Physical Activity of People with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Cartwright, Luke; Reid, Marie; Hammersley, Richard; Walley, Robert M.

    2017-01-01

    Background: The prevalence of obesity, inactivity and related morbidity and mortality is higher amongst people with intellectual disabilities than in the population in general, an issue of global concern. This research examined the perspectives of people with intellectual disabilities and their carers, on exercise and activity. Materials and…

  2. Chlamydia screening for sexually active young women under the Affordable Care Act: new opportunities and lingering barriers.

    PubMed

    Loosier, Penny S; Malcarney, Mary-Beth; Slive, Lauren; Cramer, Ryan C; Burgess, Brittany; Hoover, Karen W; Romaguera, Raul

    2014-09-01

    The Affordable Care Act of 2010 (ACA) contains a provision requiring private insurers issuing or renewing plans on or after September 23, 2010, to provide, without cost sharing, preventive services recommended by US Preventive Services Task Force (grades A and B), among other recommending bodies. As a grade A recommendation, chlamydia screening for sexually active young women 24 years and younger and older women at risk for chlamydia falls under this requirement. This article examines the potential effect on chlamydia screening among this population across private and public health plans and identifies lingering barriers not addressed by this legislation. Examination of the impact on women with private insurance touches upon the distinction between coverage under grandfathered plans, where the requirement does not apply, and nongrandfathered plans, where the requirement does apply. Acquisition of private health insurance through health insurance Marketplaces is also discussed. For public health plans, coverage of preventive services without cost sharing differs for individuals enrolled in standard Medicaid, covered under the Medicaid expansion included in the ACA, or those enrolled under the Children's Health Insurance Program or who fall under Early, Periodic, Screening, Diagnosis and Treatment criteria. The discussion of lingering barriers not addressed by the ACA includes the uninsured, physician reimbursement, cost sharing, confidentiality, low rates of appropriate sexual history taking by providers, and disclosures of sensitive information. In addition, the role of safety net programs that provide health care to individuals regardless of ability to pay is examined in light of the expectation that they also remain a payer of last resort.

  3. Rectifying conductance substates in a large conductance Ca(2+)- activated K+ channel: evidence for a fluctuating barrier mechanism

    PubMed Central

    1996-01-01

    In this study, we investigated the mechanism underlying the production of inwardly rectifying subconductance states induced in large conductance Ca(2+)-activated K+ channels (maxi K(Ca) channels) by the small, homologous proteins, bovine pancreatic trypsin inhibitor (BPTI) and dendrotoxin-I (DTX). Low-resolution bilayer recordings of BPTI- induced substates display excess noise that is well described by a beta- distribution characteristic of a filtered, two-state process. High- resolution patch recordings of maxi K(Ca) channels from vascular smooth muscle cells confirm that the BPTI-induced substate is actually comprised of rapid, voltage-dependent transitions between the open state and a nearly closed state. Patch recordings of DTX-induced substates also exhibit excess noise consistent with a similar two-state fluctuation process that occurs at rates faster than those measured for the BPTI-induced substate. The results indicate that these examples of ligand-induced substates originate by a fluctuating barrier mechanism that is similar to one class of models proposed by Dani, J.A., and J.A. Fox (1991. J. Theor. Biol. 153: 401-423) to explain subconductance behavior of ion channels. To assess the general impact of such rapid fluctuations on the practical measurement of unitary currents by amplitude histograms, we simulated single-channel records for a linear, three-state scheme of C (closed)-O(open)-S(substate). This simulation defines a range of transition rates relative to filter frequency where rapid fluctuations can lead to serious underestimation of actual unitary current levels. On the basis of these experiments and simulations, we conclude that fluctuating barrier processes and open channel noise may play an important physiological role in the modulation of ion permeation. PMID:8741730

  4. Biotransformation of hop aroma terpenoids by ale and lager yeasts.

    PubMed

    King, Andrew J; Dickinson, J Richard

    2003-03-01

    Terpenoids are important natural flavour compounds, which are introduced to beer via hopping. It has been shown recently that yeasts are able to biotransform some monoterpene alcohols. As a first step towards examining whether yeasts are capable of altering hop terpenoids during the brewing of beer, we investigated whether they were transformed when an ale and lager yeast were cultured in the presence of a commercially available syrup. Both yeasts transformed the monoterpene alcohols geraniol and linalool. The lager yeast also produced acetate esters of geraniol and citronellol. The major terpenoids of hop oil, however, were not biotransformed. Oxygenated terpenoids persisted much longer than the alkenes.

  5. Fault barriers favor activation of backthrusts near segment ends of megathrust ruptures

    NASA Astrophysics Data System (ADS)

    Xu, S.; Fukuyama, E.; Ben-Zion, Y.; Ampuero, J. P.

    2013-12-01

    Increasing evidence indicates that backthrusts may become active during or after megathrust ruptures in subduction zones, such as in Chile and Sumatra areas (Melnick et al., 2012; Singh et al., 2011). Previous studies on relevant mechanisms mainly focused on the interaction between forethrusts and the megathrust. Here we aim to investigate through dynamic rupture simulations how backthrusts may be activated by megathrust ruptures in subduction zone environment. Assuming a single backthrust branch, our preliminary results show that the activation of backthrust is difficult if the megathrust rupture can easily pass through the fault junction, owing to a quickly established stress shadow zone in the wake of the megathrust rupture front. In contrast, if the megathrust rupture is arrested or delayed around the junction, a resultant backward stress lobe of the type discussed by Xu and Ben-Zion (2013) can load the backthrust over a considerable amount of time and facilitates rupture activation along the backthrust. A number of candidates can serve to arrest or delay megathrust ruptures, such as the velocity-strengthening frictional behavior and off-fault weak materials in the shallow portion of subduction zones, fault bend or ramp, and subducted seamount. Moreover, these features are also found capable of generating backthrusts during the long-term quasi-static process, which provide pre-existing weakness to be reactivated by later dynamic ruptures. Our results agree, from a different point of view, with the study based on the critical taper theory (Cubas et al., 2013) that an increase of friction towards the trench favors the activation of backthrusts near the up-dip limit of megathrust ruptures. The results highlight the role of fault geometric or strength heterogeneities in controlling the strain partitioning on and off the main fault plane. Accordingly, activated backthrusts may be treated as markers that reflect the limits of seismogenic zones, and thus may be used

  6. METEORIN-LIKE is a cytokine associated with barrier tissues and alternatively activated macrophages

    PubMed Central

    Ushach, Irina; Burkhardt, Amanda M.; Martinez, Cynthia; Hevezi, Peter A.; Gerber, Peter Arne; Buhren, Bettina Alexandra; Schrumpf, Holger; Valle-Rios, Ricardo; Vazquez, Monica I.; Homey, Bernhard; Zlotnik, Albert

    2014-01-01

    Cytokines are involved in many functions of the immune system including initiating, amplifying and resolving immune responses. Through bioinformatics analyses of a comprehensive database of gene expression (BIGE: Body Index of Gene Expression) we observed that a small secreted protein encoded by a poorly characterized gene called meteorin-like (METRNL), is highly expressed in mucosal tissues, skin and activated macrophages. Further studies indicate that Metrnl is produced by Alternatively Activated Macrophages (AAM) and M-CSF cultured bone marrow macrophages (M2-like macrophages). In the skin, METRNL is expressed by resting fibroblasts and IFNγ-treated keratinocytes. A screen of human skin-associated diseases showed significant over-expression of METRNL in psoriasis, prurigo nodularis, actinic keratosis and atopic dermatitis. METRNL is also up-regulated in synovial membranes of human rheumatoid arthritis. Taken together, these results indicate that Metrnl represents a novel cytokine, which is likely involved in both innate and acquired immune responses. PMID:25486603

  7. Environmental factors: opportunities and barriers for physical activity, and healthy eating among children and adolescents.

    PubMed

    Huybrechts, I; De Bourdeaudhuij, I; De Henauw, S

    2010-01-01

    While genetic factors play a role in the development of obesity, the dramatic increase of its prevalence in the past years strongly suggests that environmental factors are largely responsible. The wealth and variety of food supply available 24h/day and throughout the year, the change in dietary habits due to time constraints and the change in physical activity due to technological advances all create a 'toxic' environment responsible for obesity and eating habit disorders. This manuscript describes and discusses the results of a systematic review of environmental opportunities & obstacles for physical activity and dietary intake influencing the obesity epidemic among children and adolescents. Although evidence clearly shows the impact of the environment on obesity related lifestyle factors, evidence for effective strategies combating this obesogenic environment is very scarce. Interventions aiming to change environmental factors in order to reduce obesity may include taxes/subsidies encouraging healthy eating or physical activity, extra provision of sporting facilities, efforts to improve safety and accessibility of walking, cycling or play areas or attempting to influence social meanings/values attached to weight, food or physical activity. It is clear that some level of institutionalization of systems that support the desired changes is required to sustain environmental and social changes in the long-term. At last, it is important to note that better-designed and -conducted research on the true importance of the interaction between environmental factors and psychosocial factors, including the micro- and the macro-level, for obesogenic behavioral change is needed to reassure the success of large-scale environmental change interventions.

  8. Vehicle barrier

    DOEpatents

    Hirsh, Robert A.

    1991-01-01

    A vehicle security barrier which can be conveniently placed across a gate opening as well as readily removed from the gate opening to allow for easy passage. The security barrier includes a barrier gate in the form of a cable/gate member in combination with laterally attached pipe sections fixed by way of the cable to the gate member and lateral, security fixed vertical pipe posts. The security barrier of the present invention provides for the use of cable restraints across gate openings to provide necessary security while at the same time allowing for quick opening and closing of the gate areas without compromising security.

  9. Diffusion barriers in the kinetics of water vapor adsorption/desorption on activated carbons

    SciTech Connect

    Harding, A.W.; Foley, N.J.; Thomas, K.M.; Norman, P.R.; Francis, D.C.

    1998-07-07

    The adsorption of water vapor on a highly microporous coconut-shell-derived carbon and a mesoporous wood-derived carbon was studied. These carbons were chosen as they had markedly different porous structures. The adsorption and desorption characteristics of water vapor on the activated carbons were investigated over the relative pressure range p/p{degree} = 0--0.9 for temperatures in the range 285--313 K in a static water vapor system. The adsorption isotherms were analyzed using the Dubinin-Serpinski equation, and this provided an assessment of the polarity of the carbons. The kinetics of water vapor adsorption and desorption were studied with different amounts of preadsorbed water for set changes in pressure relative to the saturated vapor pressure (p/p{degree}). The adsorption kinetics for each relative pressure step were compared and used to calculate the activation energies for the vapor pressure increments. The kinetic results are discussed in relation to their relative position on the equilibrium isotherm and the adsorption mechanism of water vapor on activated carbons.

  10. Let Me Blow Your Mind: Hip Hop Feminist Futures in Theory and Praxis

    ERIC Educational Resources Information Center

    Lindsey, Treva B.

    2015-01-01

    This essay brings together key theoretical interventions in hip-hop feminism to explore the continued, but undervalued, significance of hip-hop feminism in urban education. More specifically, the essay challenges narrow conceptualizations of the "hip hop subject" as Black and male by using hip-hop feminist theory to incorporate the lived…

  11. Curcumin Protects Intestinal Mucosal Barrier Function of Rat Enteritis via Activation of MKP-1 and Attenuation of p38 and NF-κB Activation

    PubMed Central

    Meng, Fan-Su; Zhang, Qing-Hua; Zeng, Jian-Ying; Xiao, Li-Ping; Yu, Xin-Pei; Peng, Dan-dan; Su, Lei; Xiao, Bing; Zhang, Zhen-Shu

    2010-01-01

    Background Intestinal mucosa barrier (IMB) dysfunction results in many notorious diseases for which there are currently few effective treatments. We studied curcumin's protective effect on IMB and examined its mechanism by using methotrexate (MTX) induced rat enteritis model and lipopolysaccharide (LPS) treated cell death model. Methodology/Principal Findings Curcumin was intragastrically administrated from the first day, models were made for 7 days. Cells were treated with curcumin for 30 min before exposure to LPS. Rat intestinal mucosa was collected for evaluation of pathological changes. We detected the activities of D-lactate and diamine oxidase (DAO) according to previous research and measured the levels of myeloperoxidase (MPO) and superoxide dismutase (SOD) by colorimetric method. Intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were determined by RT-PCR and IL-10 production was determined by ELISA. We found Curcumin decreased the levels of D-lactate, DAO, MPO, ICAM-1, IL-1β and TNF-α, but increased the levels of IL-10 and SOD in rat models. We further confirmed mitogen-activated protein kinase phosphatase-1 (MKP-1) was activated but phospho-p38 was inhibited by curcumin by western blot assay. Finally, NF-κB translocation was monitored by immunofluorescent staining. We showed that curcumin repressed I-κB and interfered with the translocation of NF-κB into nucleus. Conclusions/Significance The effect of curcumin is mediated by the MKP-1-dependent inactivation of p38 and inhibition of NF-κB-mediated transcription. Curcumin, with anti-inflammatory and anti-oxidant activities may be used as an effective reagent for protecting intestinal mucosa barrier and other related intestinal diseases. PMID:20885979

  12. Cloning and analysis of valerophenone synthase gene expressed specifically in lupulin gland of hop (Humulus lupulus L.).

    PubMed

    Okada, Y; Ito, K

    2001-01-01

    Resin and essential oil derived from hop (Humulus lupulus L.) cones are very important compounds for beer brewing, and they specifically accumulate in the lupulin gland of hop cones. In order to identify the genes responsible for the biosynthetic pathway of these compounds and use the identified genes for hop breeding using Marker Assisted Selection and transformation techniques, genes expressed specifically in the lupulin gland were cloned and sequenced. One of them was suggested to be similar to the chalcone synthase gene from the DNA sequence. The translation product of the gene had the activity of valerophenone synthase, which catalyzes a part of the synthesis reaction of alpha-acid and beta-acid. Northern analysis showed that the valerophenone synthase gene seemed to be expressed specifically in the lupulin gland.

  13. Effect of aroma and magnum hops extracts and paracetamol on antioxidant liver parameters in mice.

    PubMed

    Jakovljevic, Vida; Popovic, Mira; Raskovic, Aleksandar; Sabo, Ana; Horvat, Olga; Mitic, Radoslav; Vasic, Radica

    2009-01-01

    Hop varieties that are mainly grown in Serbia are Magnum (German variety) and Aroma, which is grown only in the Vojvodina region. About the use of hops extracts as an auxiliary remedy there are divergent opinions. Our findings indicate that extracts of Magnum and Aroma varieties, among the others, enhance and prolong the analgesic action of paracetamol. For this reason we undertook a study of the effects of these extracts alone and in combination with paracetamol, along with the action of paracetamol alone, on the activity of the antioxidant enzymes GSHPx, CAT, Px, XOD, GSHR, glutathione content, LPx intensity, as well as activities of AST and ALT. Paracetamol in the dose applied exerted no influence on the investigated parameters and neither did ethanolic extract of Magnum variety. On the other hand, ethanolic extract of Aroma hops caused a significant reduction of GSH content. In combination with paracetamol, extracts of both Magnum and Aroma varieties reduced significantly the LPx intensity, activities of CAT and GSHPx, as well as GSH content in the liver homogenate. A significant increase in the AST value with respect to control was also observed. These findings indicate the disturbance in the functioning of hepatocytes, probably by decelarating metabolism and elimination of paracetamol.

  14. Effect of aroma and magnum hops extracts and paracetamol on antioxidant liver parameters in mice.

    PubMed

    Jakovljevic, Vida; Popovic, Mira; Raskovic, Aleksandar; Sabo, Ana; Vasic, Radica

    2008-01-01

    Hop varieties that are mainly grown in Serbia are Magnum (German variety) and Aroma, which is grown only in the Vojvodina region. About the use of hops extracts as an auxiliary remedy there are divergent opinions. Our findings indicate that extracts of Magnum and Aroma varieties, among the others, enhance and prolong the analgesic action of paracetamol. For this reason we undertook a study of the effects of these extracts alone and in combination with paracetamol, along with the action of paracetamol alone, on the activity of the antioxidant enzymes GSHPx, CAT, Px, XOD, GSHR, glutathione content, LPx intensity, as well as activities of AST and ALT. Paracetamol in the dose applied exerted no influence on the investigated parameters and neither did ethanolic extract of Magnum variety. On the other hand, ethanolic extract of Aroma hops caused a significant reduction of GSH content. In combination with paracetamol, extracts of both Magnum and Aroma varieties reduced significantly the LPx intensity, activities of CAT and GSHPx, as well as GSH content in the liver homogenate. A significant increase in the AST value with respect to control was also observed. These findings indicate the disturbance in the functioning of hepatocytes, probably by decelarating metabolism and elimination of paracetamol.

  15. Modulation of breast cancer cell survival by aromatase inhibiting hop (Humulus lupulus L.) flavonoids.

    PubMed

    Monteiro, Rosário; Faria, Ana; Azevedo, Isabel; Calhau, Conceição

    2007-01-01

    Hop flavonoids are being regarded as attractive molecules to prevent or treat certain forms of cancer. Studies have focused mainly on xanthohumol, the most abundant prenylated chalcone existing in hops extract. However, during the production of beer, or after its ingestion, xanthohumol originates different metabolites, among which isoxanthohumol and 8-prenylnaringenin. The aim of this work was to study the effect of the prenylflavonoids xanthohumol, isoxanthohumol and 8-prenylnaringenin on the breast cancer Sk-Br-3 cell line proliferation, apoptosis and activity of the enzyme aromatase (estrogen synthase). Aromatase activity was determined by a tritiated water assay, cell proliferation was assessed by [(3)H]thymidine incorporation, sulforhodamine B protein measurement and Ki-67 immunostaining and apoptosis was determined by TUNEL. Our results show that all tested prenylflavonoids were able to inhibit aromatase activity and thus, estrogen formation. Additionally, breast cancer cell line proliferation was decreased and apoptosis induced by all three compounds. The presence of 17beta-estradiol in treatment medium was able to revert the effect of the prenylflavonoids on cellular proliferation. These observations strengthen the idea that hop flavonoids may have anti-breast cancer effects and shed new light on a possible mechanism of action by which these effects occur, namely through their ability to decrease estrogen synthesis.

  16. Hop bitter acids inhibit tumorigenicity of hepatocellular carcinoma cells in vitro.

    PubMed

    Saugspier, Michael; Dorn, Christoph; Czech, Barbara; Gehrig, Manfred; Heilmann, Jörg; Hellerbrand, Claus

    2012-10-01

    Bitter acids (BAs) from the hop plant Humulus lupulus L. exhibit multiple beneficial biological properties with promising effects in cancer therapy and prevention, but information regarding the effects on hepatocellular carcinoma (HCC) is missing. Here, we used two different hop bitter acid extracts enriched for either α-acids or β-acids to obtain insight into whether biological activity varies between these two groups of BAs. At a concentration of 25 µg/ml, only the β-acid rich started to induce aspartate transaminase (AST) release, and a significant increase was detected with 50 µg/ml of both extracts. Already at lower concentrations both extracts led to a dose-dependent inhibition of proliferation, and migration was suppressed at a concentration as low as 5 µg/ml in HCC cells. The focus on different signaling pathways revealed an inhibition of ERK1/2 phosphorylation, downregulation of AP-1 activity and an alleviation of nuclear factor κB (NFκB) activity in HepG2 cells incubated with 5 µg/ml of both extracts, whereby the β-acid rich extract showed more pronounced effects. In conclusion, we identified ERK1/2, AP-1 and NFκB, which are important factors in tumor development and progression, as targets of hop BAs. Thus, these data suggest the potential use of BAs as functional nutrients for both prevention and treatment of HCC.

  17. Computational models to predict blood brain barrier permeation and CNS activity

    NASA Astrophysics Data System (ADS)

    Subramanian, Govindan; Kitchen, Douglas B.

    2003-10-01

    The blood-brain permeation of a structurally diverse set of 281 compounds was modeled using linear regression and a multivariate genetic partial least squares (G/PLS) approach. Key structural features affecting the logarithm of blood-brain partitioning (logBB) were captured through statistically significant quantitative structure-activity relationship (QSAR) models. These relationships reveal the importance of logP, polar surface area, and a variety of electrotopological indices for accurate predictions of logBB. The best models reveal an excellent correlation (r > 0.9) for a training set of 58 compounds. Likewise, the comparison of the average logBB values obtained from an ensemble of QSAR models with experimental values also verifies the statistical quality of the models (r > 0.9). The models provide good agreement (r ˜ 0.7) between the predicted logBB values for 34 molecules in the external validation set and the experimental values. To further validate the models for use during the drug discovery process, a prediction set of 181 drugs with reported CNS penetration data was used. A >70% success rate is obtained by using any of the QSAR models in the qualitative prediction for CNS permeable (active) drugs. A lower success rate (˜60%) was obtained for the best model for CNS impermeable (inactive) drugs. Combining the predictions obtained from all the models (consensus) did not significantly improve the discrimination of CNS active and CNS inactive molecules. Finally, using the therapeutic classification as a guiding tool, the CNS penetration capability of over 2000 compounds in the Synthline® database was estimated. The results were very similar to the smaller set of 181 compounds.

  18. Primary Care and Public Health Activities in Select US Health Centers: Documenting Successes, Barriers, and Lessons Learned

    PubMed Central

    Shi, Leiyu; Chowdhury, Joya; Sripipatana, Alek; Zhu, Jinsheng; Sharma, Ravi; Hayashi, A. Seiji; Daly, Charles A.; Tomoyasu, Naomi; Nair, Suma; Ngo-Metzger, Quyen

    2012-01-01

    Objectives. We examined primary care and public health activities among federally funded health centers, to better understand their successes, the barriers encountered, and the lessons learned. Methods. We used qualitative and quantitative methods to collect data from 9 health centers, stratified by administrative division, urban–rural location, and race/ethnicity of patients served. Descriptive data on patient and institutional characteristics came from the Uniform Data System, which collects data from all health centers annually. We administered questionnaires and conducted phone interviews with key informants. Results. Health centers performed well on primary care coordination and community orientation scales and reported conducting many essential public health activities. We identified specific needs for integrating primary care and public health: (1) more funding for collaborations and for addressing the social determinants of health, (2) strong leadership to champion collaborations, (3) trust building among partners, with shared missions and clear expectations of responsibilities, and (4) alignment and standardization of data collection, analysis, and exchange. Conclusions. Lessons learned from health centers should inform strategies to better integrate public health with primary care. PMID:22690975

  19. miR-155 Modifies Inflammation, Endothelial Activation and Blood-Brain Barrier Dysfunction in Cerebral Malaria

    PubMed Central

    Barker, Kevin R; Lu, Ziyue; Kim, Hani; Zheng, Ying; Chen, Junmei; Conroy, Andrea L; Hawkes, Michael; Cheng, Henry S; Njock, Makon-Sébastien; Fish, Jason E; Harlan, John M; López, Jose A; Liles, W Conrad; Kain, Kevin C

    2017-01-01

    miR-155 has been shown to participate in host response to infection and neuroinflammation via negative regulation of blood-brain barrier (BBB) integrity and T cell function. We hypothesized that miR-155 may contribute to the pathogenesis of cerebral malaria (CM). To test this hypothesis, we used a genetic approach to modulate miR-155 expression in an experimental model of cerebral malaria (ECM). In addition, an engineered endothelialized microvessel system and serum samples from Ugandan children with CM were used to examine anti–miR-155 as a potential adjunctive therapeutic for severe malaria. Despite higher parasitemia, survival was significantly improved in miR-155-/- mice versus wild-type littermate mice in ECM. Improved survival was associated with preservation of BBB integrity and reduced endothelial activation, despite increased levels of proinflammatory cytokines. Pretreatment with antagomir-155 reduced vascular leak induced by human CM sera in an ex vivo endothelial microvessel model. These data provide evidence supporting a mechanistic role for miR-155 in host response to malaria via regulation of endothelial activation, microvascular leak and BBB dysfunction in CM. PMID:28182191

  20. The role of multidrug resistance protein (MRP-1) as an active efflux transporter on blood-brain barrier (BBB) permeability.

    PubMed

    Lingineni, Karthik; Belekar, Vilas; Tangadpalliwar, Sujit R; Garg, Prabha

    2017-01-03

    Drugs acting on central nervous system (CNS) may take longer duration to reach the market as these compounds have a higher attrition rate in clinical trials due to the complexity of the brain, side effects, and poor blood-brain barrier (BBB) permeability compared to non-CNS-acting compounds. The roles of active efflux transporters with BBB are still unclear. The aim of the present work was to develop a predictive model for BBB permeability that includes the MRP-1 transporter, which is considered as an active efflux transporter. A support vector machine model was developed for the classification of MRP-1 substrates and non-substrates, which was validated with an external data set and Y-randomization method. An artificial neural network model has been developed to evaluate the role of MRP-1 on BBB permeation. A total of nine descriptors were selected, which included molecular weight, topological polar surface area, ClogP, number of hydrogen bond donors, number of hydrogen bond acceptors, number of rotatable bonds, P-gp, BCRP, and MRP-1 substrate probabilities for model development. We identified 5 molecules that fulfilled all criteria required for passive permeation of BBB, but they all have a low logBB value, which suggested that the molecules were effluxed by the MRP-1 transporter.

  1. Nuclear pore complex evolution: a trypanosome Mlp analogue functions in chromosomal segregation but lacks transcriptional barrier activity.

    PubMed

    Holden, Jennifer M; Koreny, Ludek; Obado, Samson; Ratushny, Alexander V; Chen, Wei-Ming; Chiang, Jung-Hsien; Kelly, Steven; Chait, Brian T; Aitchison, John D; Rout, Michael P; Field, Mark C

    2014-05-01

    The nuclear pore complex (NPC) has dual roles in nucleocytoplasmic transport and chromatin organization. In many eukaryotes the coiled-coil Mlp/Tpr proteins of the NPC nuclear basket have specific functions in interactions with chromatin and defining specialized regions of active transcription, whereas Mlp2 associates with the mitotic spindle/NPC in a cell cycle-dependent manner. We previously identified two putative Mlp-related proteins in African trypanosomes, TbNup110 and TbNup92, the latter of which associates with the spindle. We now provide evidence for independent ancestry for TbNup92/TbNup110 and Mlp/Tpr proteins. However, TbNup92 is required for correct chromosome segregation, with knockout cells exhibiting microaneuploidy and lowered fidelity of telomere segregation. Further, TbNup92 is intimately associated with the mitotic spindle and spindle anchor site but apparently has minimal roles in control of gene transcription, indicating that TbNup92 lacks major barrier activity. TbNup92 therefore acts as a functional analogue of Mlp/Tpr proteins, and, together with the lamina analogue NUP-1, represents a cohort of novel proteins operating at the nuclear periphery of trypanosomes, uncovering complex evolutionary trajectories for the NPC and nuclear lamina.

  2. Adaptive time steps in trajectory surface hopping simulations

    NASA Astrophysics Data System (ADS)

    Spörkel, Lasse; Thiel, Walter

    2016-05-01

    Trajectory surface hopping (TSH) simulations are often performed in combination with active-space multi-reference configuration interaction (MRCI) treatments. Technical problems may arise in such simulations if active and inactive orbitals strongly mix and switch in some particular regions. We propose to use adaptive time steps when such regions are encountered in TSH simulations. For this purpose, we present a computational protocol that is easy to implement and increases the computational effort only in the critical regions. We test this procedure through TSH simulations of a GFP chromophore model (OHBI) and a light-driven rotary molecular motor (F-NAIBP) on semiempirical MRCI potential energy surfaces, by comparing the results from simulations with adaptive time steps to analogous ones with constant time steps. For both test molecules, the number of successful trajectories without technical failures rises significantly, from 53% to 95% for OHBI and from 25% to 96% for F-NAIBP. The computed excited-state lifetime remains essentially the same for OHBI and increases somewhat for F-NAIBP, and there is almost no change in the computed quantum efficiency for internal rotation in F-NAIBP. We recommend the general use of adaptive time steps in TSH simulations with active-space CI methods because this will help to avoid technical problems, increase the overall efficiency and robustness of the simulations, and allow for a more complete sampling.

  3. One-dimensional potential of mean force underestimates activation barrier for transport across flexible lipid membranes

    NASA Astrophysics Data System (ADS)

    Kopelevich, Dmitry I.

    2013-10-01

    Transport of a fullerene-like nanoparticle across a lipid bilayer is investigated by coarse-grained molecular dynamics (MD) simulations. Potentials of mean force (PMF) acting on the nanoparticle in a flexible bilayer suspended in water and a bilayer restrained to a flat surface are computed by constrained MD simulations. The rate of the nanoparticle transport into the bilayer interior is predicted using one-dimensional Langevin models based on these PMFs. The predictions are compared with the transport rates obtained from a series of direct (unconstrained) MD simulations of the solute transport into the flexible bilayer. It is observed that the PMF acting on the solute in the flexible membrane underestimates the transport rate by more than an order of magnitude while the PMF acting on the solute in the restrained membrane yields an accurate estimate of the activation energy for transport into the flexible membrane. This paradox is explained by a coexistence of metastable membrane configurations for a range of the solute positions inside and near the flexible membrane. This leads to a significant reduction of the contribution of the transition state to the mean force acting on the solute. Restraining the membrane shape ensures that there is only one stable membrane configuration corresponding to each solute position and thus the transition state is adequately represented in the PMF. This mechanism is quite general and thus this phenomenon is expected to occur in a wide range of interfacial systems. A simple model for the free energy landscape of the coupled solute-membrane system is proposed and validated. This model explicitly accounts for effects of the membrane deformations on the solute transport and yields an accurate prediction of the activation energy for the solute transport.

  4. One-dimensional potential of mean force underestimates activation barrier for transport across flexible lipid membranes.

    PubMed

    Kopelevich, Dmitry I

    2013-10-07

    Transport of a fullerene-like nanoparticle across a lipid bilayer is investigated by coarse-grained molecular dynamics (MD) simulations. Potentials of mean force (PMF) acting on the nanoparticle in a flexible bilayer suspended in water and a bilayer restrained to a flat surface are computed by constrained MD simulations. The rate of the nanoparticle transport into the bilayer interior is predicted using one-dimensional Langevin models based on these PMFs. The predictions are compared with the transport rates obtained from a series of direct (unconstrained) MD simulations of the solute transport into the flexible bilayer. It is observed that the PMF acting on the solute in the flexible membrane underestimates the transport rate by more than an order of magnitude while the PMF acting on the solute in the restrained membrane yields an accurate estimate of the activation energy for transport into the flexible membrane. This paradox is explained by a coexistence of metastable membrane configurations for a range of the solute positions inside and near the flexible membrane. This leads to a significant reduction of the contribution of the transition state to the mean force acting on the solute. Restraining the membrane shape ensures that there is only one stable membrane configuration corresponding to each solute position and thus the transition state is adequately represented in the PMF. This mechanism is quite general and thus this phenomenon is expected to occur in a wide range of interfacial systems. A simple model for the free energy landscape of the coupled solute-membrane system is proposed and validated. This model explicitly accounts for effects of the membrane deformations on the solute transport and yields an accurate prediction of the activation energy for the solute transport.

  5. Corneal critical barrier against the penetration of dexamethasone and lomefloxacin hydrochloride: evaluation by the activation energy for drug partition and diffusion in cornea.

    PubMed

    Yasueda, Shin-ichi; Higashiyama, Masayo; Yamaguchi, Masazumi; Isowaki, Akiharu; Ohtori, Akira

    2007-08-01

    The cornea is a solid barrier against drug permeation. We searched the critical barrier of corneal drug permeation using a hydrophobic drug, dexamethasone (DM), and a hydrophilic drug, lomefloxacin hydrochloride (LFLX). The activation energies for permeability of DM and LFLX across the intact cornea were 88.0 and 42.1 kJ/mol, respectively. Their activation energies for permeability across the cornea without epithelium decreased to 33.1 and 16.6 kJ/mol, respectively. The results show that epithelium is the critical barrier on the cornea against the permeation of a hydrophobic drug of DM as well as a hydrophilic drug of LFLX. The activation energy of partition for DM (66.8 kJ/mol) was approximately 3-fold larger than that of diffusion (21.2 kJ/mol). The results indicate that the partition for the hydrophobic drug of DM to the corneal epithelium is the primary barrier. Thermodynamic evaluation of activation energy for the drug permeation parameters is a good approach to investigate the mechanism of drug permeability.

  6. Giving the Teacher a Voice: Perceptions Regarding the Barriers and Enablers Associated with the Implementation of Smart Moves (Compulsory Physical Activity) within Primary State Schools

    ERIC Educational Resources Information Center

    Usher, Wayne; Anderton, Amy

    2014-01-01

    The specific focus of this study is to explore Queensland (Australia) state school generalist teachers' perceptions regarding the barriers and enablers associated with the implementation of the Smart Moves (compulsory physical activity) policy in the primary classroom setting. This study sought to primarily add to the literature on, and…

  7. The APPLE Project: An Investigation of the Barriers and Promoters of Healthy Eating and Physical Activity in New Zealand Children Aged 5-12 Years

    ERIC Educational Resources Information Center

    Williden, Micalla; Taylor, Rachael W; McAuley, Kirsten A; Simpson, Jean C; Oakley, Maggie; Mann, Jim I

    2006-01-01

    Objective: To use the Analysis Grid for Environments Linked to Obesity (ANGELO) framework to determine the barriers and promoters of healthy eating and physical activity in children aged 5-12 years, as a basis for the development of a pilot community-based programme for preventing obesity in children (APPLE project: A Pilot Programme for Lifestyle…

  8. Corrigendum to "PAHs in the Great Barrier Reef Lagoon reach potentially toxic levels from coal port activities" [Estuar. Coast. Shelf Sci. 144, 39-45

    NASA Astrophysics Data System (ADS)

    Burns, Kathryn A.

    2014-08-01

    Erratum with respect to the paper: Burns, K A, 2014 PAHs in the Great Barrier Reef Lagoon reach potentially toxic levels from coal port activities. Estuarine Coastal and Shelf Science 144, 39-45. DOI 10.1016/j.ecss.2014.04.001.

  9. Development of frequency synthesizer for fast frequency hopping communication equipment

    NASA Astrophysics Data System (ADS)

    Sekizawa, Shinya; Moriyama, Eimatsu

    1990-06-01

    A frequency synthesizer with rapid operation is necessary for the development of fast frequency hopping communication systems in land mobile radios. On the other hand, accuracy is not so important in the fast frequency hopping systems when envelope detection is employed in a receiver. Currently, there are several types of frequency synthesizers. However, they are not sufficient in terms of switching speed, size and cost. A frequency synthesizer with rapid hopping based on a new operating principle is proposed and developed. It is a small synthesizer, consisting of digital devices, available at a low cost. The experimental results show that the synthesizer has the switching performance necessary for frequency hopping land mobile radios. This paper describes the operating principle and the experimental results of the proposed synthesizer.

  10. 59. View of lined canal east of bellmouth near hop ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. View of lined canal east of bellmouth near hop barn, looking southwest. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  11. 60. View of lined canal and hop barn, looking southwest. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. View of lined canal and hop barn, looking southwest. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  12. GENERAL VIEW OF SITE LOOKING SOUTHWEST. JUPITER 'HOP' STAND, FOREGROUND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL VIEW OF SITE LOOKING SOUTHWEST. JUPITER 'HOP' STAND, FOREGROUND CENTER, REDSTONE TEST STAND FOREGROUND RIGHT, SATURN I C TEST STAND BACKGROUND LEFT. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  13. Activation of Alpha 7 Cholinergic Nicotinic Receptors Reduce Blood–Brain Barrier Permeability following Experimental Traumatic Brain Injury

    PubMed Central

    Zhao, Jing; Kobori, Nobuhide; Redell, John B.; Hylin, Michael J.; Hood, Kimberly N.; Moore, Anthony N.

    2016-01-01

    Traumatic brain injury (TBI) is a major human health concern that has the greatest impact on young men and women. The breakdown of the blood–brain barrier (BBB) is an important pathological consequence of TBI that initiates secondary processes, including infiltration of inflammatory cells, which can exacerbate brain inflammation and contribute to poor outcome. While the role of inflammation within the injured brain has been examined in some detail, the contribution of peripheral/systemic inflammation to TBI pathophysiology is largely unknown. Recent studies have implicated vagus nerve regulation of splenic cholinergic nicotinic acetylcholine receptor α7 (nAChRa7) signaling in the regulation of systemic inflammation. However, it is not known whether this mechanism plays a role in TBI-triggered inflammation and BBB breakdown. Following TBI, we observed that plasma TNF-α and IL-1β levels, as well as BBB permeability, were significantly increased in nAChRa7 null mice (Chrna7−/−) relative to wild-type mice. The administration of exogenous IL-1β and TNF-α to brain-injured animals worsened Evans Blue dye extravasation, suggesting that systemic inflammation contributes to TBI-triggered BBB permeability. Systemic administration of the nAChRa7 agonist PNU-282987 or the positive allosteric modulator PNU-120596 significantly attenuated TBI-triggered BBB compromise. Supporting a role for splenic nAChRa7 receptors, we demonstrate that splenic injection of the nicotinic receptor blocker α-bungarotoxin increased BBB permeability in brain-injured rats, while PNU-282987 injection decreased such permeability. These effects were not seen when α-bungarotoxin or PNU-282987 were administered to splenectomized, brain-injured rats. Together, these findings support the short-term use of nAChRa7-activating agents as a strategy to reduce TBI-triggered BBB permeability. SIGNIFICANCE STATEMENT Breakdown of the blood–brain barrier (BBB) in response to traumatic brain injury (TBI

  14. Construction of gene expression system in hop (Humulus lupulus) lupulin gland using valerophenone synthase promoter.

    PubMed

    Okada, Yukio; Saeki, Kazuo; Inaba, Akira; Suda, Narushi; Kaneko, Takafumi; Ito, Kazutoshi

    2003-09-01

    The promoter region of the valerophenone synthase (VPS) gene was isolated from hop (Humulus lupulus). VPS, a member of the chalcone synthase (CHS) super-family, catalyzes the biosynthesis reaction of the hop resin that significantly accumulates in the cone's secretory gland called the "lupulin gland". The typical H-box and G-box sequences, which exist in many plants' CHS promoters and act as cis-elements for tissue specificity, UV-light induction, etc., were not found in the isolated VPS promoter, although the H-box-like sequence (CCTTACC, CCTAACC) and the core sequence (ACGT) of the G-box were observed. The transformation experiment using the VPS promoter-UIDA gene fusion revealed that the promoter acts not only in the lupulin gland but also in the glands of leaf and stem. On the other hand, the VPS promoter activity was not induced by UV-irradiation.

  15. Ability of prenylflavanones present in hops to induce apoptosis in a human Burkitt lymphoma cell line.

    PubMed

    Diller, Reinhard A; Riepl, Herbert M; Rose, Oliver; Frias, Corazon; Henze, Günter; Prokop, Aram

    2007-07-01

    The identification of effective cancer preventive compounds from hops has become an important issue in public health-related research. We compared the antiproliferative and apoptosis-inducing effects of side chain variants of prenylflavanones, e. g., 8-prenylnaringenin (7) and 8-geranylnaringenin (10), which have been identified in hops (Humulus lupulus), and their synthetic variations 8-furanmethylnaringenin (8) and 8-cinnamylnaringenin (9). These were accessible by a Mitsunobu reaction and Claisen rearrangement. Flavanones 9 and 10 showed cytotoxic and apoptotic activities. Apoptosis was induced in a mitochondrial dependent manner. 8-Cinnamylnaringenin (9) displayed noticeably improved apoptotic effects when compared to 8-prenylnaringenin. The potential of 8-prenylnaringenin (7) is shown in an ex vivo experiment on a multi-drug resistant leukaemia blast.

  16. Mediating Effects of Self-Efficacy, Benefits and Barriers on the Association between Peer and Parental Factors and Physical Activity among Adolescent Girls with a Lower Educational Level

    PubMed Central

    Cardon, Greet; De Craemer, Marieke; D’Haese, Sara; De Bourdeaudhuij, Ilse

    2016-01-01

    Background The prevalence of physical activity among lower educated adolescent girls is low, suggesting it is important to have insights into the complex processes that may underlie their physical activity levels. Therefore, this study aimed to examine the mediating effects of self-efficacy, perceived benefits and barriers on the associations between peer and parental variables and physical activity among lower educated adolescent girls. Methods In total, 226 girls (mean age 16.0±1.0 years; 53% technical education; 47% vocational education) from a convenience sample of 6 secondary schools in Flanders, Belgium, completed a questionnaire on their total physical activity level and related peer and parental variables (i.e. modeling of physical activity, co-participation in physical activities and encouragement to be active) and personal variables (i.e. self-efficacy to be active, and specific perceived benefits of physical activity and specific barriers to be active). Mediating effects were tested using MacKinnon’s product-of-coefficients test based on multilevel linear regression analyses. Results Higher peer and parental modeling, co-participation and encouragement were significantly related to a higher physical activity level among adolescent girls (p<0.05). Self-efficacy, the perceived benefits of having fun, being around friends or meeting new people, and not being bored and the perceived barrier of not liking physical activity mediated several associations between peer and parental variables and girls’ physical activity, with some of the mediated proportions exceeding 60%. Conclusions This study contributed to a better understanding of the complexity of how parental and peer factors work together with personal factors to influence the physical activity levels of adolescent girls with a lower educational level. Interventions should involve both peers and parents, as they may influence girls’ physical activity both directly and indirectly through the

  17. Leg exoskeleton reduces the metabolic cost of human hopping.

    PubMed

    Grabowski, Alena M; Herr, Hugh M

    2009-09-01

    During bouncing gaits such as hopping and running, leg muscles generate force to enable elastic energy storage and return primarily from tendons and, thus, demand metabolic energy. In an effort to reduce metabolic demand, we designed two elastic leg exoskeletons that act in parallel with the wearer's legs; one exoskeleton consisted of a multiple leaf (MLE) and the other of a single leaf (SLE) set of fiberglass springs. We hypothesized that hoppers, hopping on both legs, would adjust their leg stiffness while wearing an exoskeleton so that the combination of the hopper and exoskeleton would behave as a linear spring-mass system with the same total stiffness as during normal hopping. We also hypothesized that decreased leg force generation while wearing an exoskeleton would reduce the metabolic power required for hopping. Nine subjects hopped in place at 2.0, 2.2, 2.4, and 2.6 Hz with and without an exoskeleton while we measured ground reaction forces, exoskeletal compression, and metabolic rates. While wearing an exoskeleton, hoppers adjusted their leg stiffness to maintain linear spring-mass mechanics and a total stiffness similar to normal hopping. Without accounting for the added weight of each exoskeleton, wearing the MLE reduced net metabolic power by an average of 6% and wearing the SLE reduced net metabolic power by an average of 24% compared with hopping normally at frequencies between 2.0 and 2.6 Hz. Thus, when hoppers used external parallel springs, they likely decreased the mechanical work performed by the legs and substantially reduced metabolic demand compared with hopping without wearing an exoskeleton.

  18. The Arabidopsis ZED1 pseudokinase is required for ZAR1-mediated immunity induced by the Pseudomonas syringae type III effector HopZ1a

    PubMed Central

    Lewis, Jennifer D.; Lee, Amy Huei-Yi; Hassan, Jana A.; Wan, Janet; Hurley, Brenden; Jhingree, Jacquelyn R.; Wang, Pauline W.; Lo, Timothy; Youn, Ji-Young; Guttman, David S.; Desveaux, Darrell

    2013-01-01

    Plant and animal pathogenic bacteria can suppress host immunity by injecting type III secreted effector (T3SE) proteins into host cells. However, T3SEs can also elicit host immunity if the host has evolved a means to recognize the presence or activity of specific T3SEs. The diverse YopJ/HopZ/AvrRxv T3SE superfamily, which is found in both animal and plant pathogens, provides examples of T3SEs playing this dual role. The T3SE HopZ1a is an acetyltransferase carried by the phytopathogen Pseudomonas syringae that elicits effector-triggered immunity (ETI) when recognized in Arabidopsis thaliana by the nucleotide-binding leucine-rich repeat (NB-LRR) protein ZAR1. However, recognition of HopZ1a does not require any known ETI-related genes. Using a forward genetics approach, we identify a unique ETI-associated gene that is essential for ZAR1-mediated immunity. The hopZ-ETI-deficient1 (zed1) mutant is specifically impaired in the recognition of HopZ1a, but not the recognition of other unrelated T3SEs or in pattern recognition receptor (PRR)-triggered immunity. ZED1 directly interacts with both HopZ1a and ZAR1 and is acetylated on threonines 125 and 177 by HopZ1a. ZED1 is a nonfunctional kinase that forms part of small genomic cluster of kinases in Arabidopsis. We hypothesize that ZED1 acts as a decoy to lure HopZ1a to the ZAR1–resistance complex, resulting in ETI activation. PMID:24170858

  19. Xanthohumol from hop cones (Humulus lupulus L.) prevents ADP-induced platelet reactivity.

    PubMed

    Luzak, Boguslawa; Kassassir, Hassan; Rój, Edward; Stanczyk, Lidia; Watala, Cezary; Golanski, Jacek

    2017-02-01

    Hop cones (Humulus lupulus L.), very rich source of phenolic compounds, possessing anticancer, antioxidant and anti-inflammatory activities, are considered as beneficial diet ingredients improving human health. In this study, the antiplatelet action of xanthohumol (XN), the principal flavonoid in hop cones, was investigated. XN significantly attenuated ADP-induced blood platelet aggregation (97.2 ± 35.7 AU for 6 μg/ml of XN vs. 120.4 ± 30.1 AU for 0.17% dimethyl sulfoxide (DMSO), p < 0.001) and significantly reduced the expression of fibrinogen receptor (activated form of GPIIbIIIa) on platelets' surface (47.6 ± 15.8 for 1.5 μg/ml XN, 44.6 ± 17.3% for 3 μg/ml XN vs. 54.5 ± 19.2% for control or 43.3 ± 18.4% for 6 μg/ml XN vs. 49.7 ± 19.4% for 0.17% DMSO, p < 0.05 or less). These findings suggest that the phenolic compounds originating from hops (XN) have a novel role as antiplatelet agents and can likely be used as dietary supplements in prophylactic approaches.

  20. The influence of ecological and conventional plant production systems on soil microbial quality under hops (Humulus lupulus).

    PubMed

    Oszust, Karolina; Frąc, Magdalena; Gryta, Agata; Bilińska, Nina

    2014-06-03

    The knowledge about microorganisms-activity and diversity under hop production is still limited. We assumed that, different systems of hop production (within the same soil and climatic conditions) significantly influence on the composition of soil microbial populations and its functional activity (metabolic potential). Therefore, we compared a set of soil microbial properties in the field experiment of two hop production systems (a) ecological based on the use of probiotic preparations and organic fertilization (b) conventional-with the use of chemical pesticides and mineral fertilizers. Soil analyses included following microbial properties: The total number microorganisms, a bunch of soil enzyme activities, the catabolic potential was also assessed following Biolog EcoPlates®. Moreover, the abundance of ammonia-oxidizing archaea (AOA) was characterized by terminal restriction fragment length polymorphism analysis (T-RFLP) of PCR ammonia monooxygenase α-subunit (amoA) gene products. Conventional and ecological systems of hop production were able to affect soil microbial state in different seasonal manner. Favorable effect on soil microbial activity met under ecological, was more probably due to livestock-based manure and fermented plant extracts application. No negative influence on conventional hopyard soil was revealed. Both type of production fulfilled fertilizing demands. Under ecological production it was due to livestock-based manure fertilizers and fermented plant extracts application.