136 research outputs found

    No evidence of flavour-nutrient learning in a two-week ‘home exposure’ study in humans

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    Flavour-nutrient learning is robust in animals but remains elusive in humans. Recent evidence suggests flavour-nutrient learning may be more likely to occur with beverages that contain relatively few calories (compared to no calories), while others show that learned associations can influence satiation, without an effect on preference. The objective of this research was to determine whether acquired liking for a caloric drink could be observed in a ‘home learning’ context over 2 weeks, and whether it is impacted by viscosity. In combination, we also explored changes in learning relating to fullness and expected satiety. In a double-blind study, participants (N = 83; BMI = 23.3 kg/m2) were randomly allocated to one of four groups differing in either calories (0 kcal vs. 112.5 kcal) or viscosity (low vs. high) and consumed a novel-flavoured drink over 15 days. Measures of flavour (10 ml sample) and beverage liking, grip force (a measure of beverage reward value), fullness, and expected satiety were taken at the start and the end of the study. While the high-viscous beverages were less liked (M = 40.3 mm, SD = 24.7) than the low viscous beverages (M = 64.4 mm, SD = 15.3; p = .022), there was no evidence that repeated exposure to a calorie-containing beverage impacted subsequent liking for the flavour (p = .115) or for the beverage (p = .448), grip force (ps > .26), fullness, and expected satiety (ps > .12). Accordingly, we conclude that we found no evidence of flavour-nutrient learning and flavour-satiety learning. This null finding accords with previous observations indicating that humans do not acquire flavour-nutrient associations as readily as some non-human animals

    Fulde-Ferrell-Larkin-Ovchinnikov states in one-dimensional spin-polarized ultracold atomic Fermi gases

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    We present a systematic study of quantum phases in a one-dimensional spin-polarized Fermi gas. Three comparative theoretical methods are used to explore the phase diagram at zero temperature: the mean-field theory with either an order parameter in a single-plane-wave form or a self-consistently determined order parameter using the Bogoliubov-de Gennes equations, as well as the exact soluble Bethe ansatz method. We find that a spatially inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov phase, which lies between the fully paired BCS state and the fully polarized normal state, dominates most of the phase diagram of a uniform gas. The phase transition from the BCS state to the Fulde-Ferrell-Larkin-Ovchinnikov phase is of second order, and therefore there are no phase separation states in one-dimensional homogeneous polarized gases. This is in sharp contrast to the three-dimensional situation, where a phase separation regime is predicted to occupy a very large space in the phase diagram. We conjecture that the prediction of the dominance of the phase separation phases in three dimension could be an artifact of the non-self-consistent mean-field approximation, which is heavily used in the study of three-dimensional polarized Fermi gases. We consider also the effect of a harmonic trapping potential on the phase diagram, and find that in this case the trap generally leads to phase separation, in accord with the experimental observations for a trapped gas in three dimension. We finally investigate the local fermionic density of states of the Fulde-Ferrell-Larkin-Ovchinnikov ansatz. A two-energy-gap structure is shown up, which could be used as an experimental probe of the Fulde-Ferrell-Larkin-Ovchinnikov states.Comment: 22 papes, 19 figure

    The Generality of the GUGA MRCI Approach in COLUMBUS for Treating Complex Quantum Chemistry

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    The core part of the program system COLUMBUS allows highly efficient calculations using variational multireference (MR) methods in the framework of configuration interaction with single and double excitations (MR-CISD) and averaged quadratic coupled-cluster calcu- lations (MR-AQCC), based on uncontracted sets of configurations and the graphical unitary group approach (GUGA). The availability of analytic MR-CISD and MR-AQCC energy gradients and analytic nonadiabatic couplings for MR-CISD enables exciting applications including, e.g., investigations of π-conjugated biradicaloid compounds, calculations of multitudes of excited states, development of dia- batization procedures, and furnishing the electronic structure information for on-the-fly surface nonadiabatic dynamics. With fully vari- ational uncontracted spin-orbit MRCI, COLUMBUS provides a unique possibility of performing high-level calculations on compounds containing heavy atoms up to lanthanides and actinides. Crucial for carrying out all of these calculations effectively is the availability of an efficient parallel code for the CI step. Configuration spaces of several billion in size now can be treated quite routinely on stan- dard parallel computer clusters. Emerging developments in COLUMBUS, including the all configuration mean energy multiconfiguration self-consistent field method and the graphically contracted function method, promise to allow practically unlimited configuration space dimensions. Spin density based on the GUGA approach, analytic spin-orbit energy gradients, possibilities for local electron correlation MR calculations, development of general interfaces for nonadiabatic dynamics, and MRCI linear vibronic coupling models conclude this overview

    Classical magnetotransport of inhomogeneous conductors

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    We present a model of magnetotransport of inhomogeneous conductors based on an array of coupled four-terminal elements. We show that this model generically yields non-saturating magnetoresistance at large fields. We also discuss how this approach simplifies finite-element analysis of bulk inhomogeneous semiconductors in complex geometries. We argue that this is an explanation of the observed non-saturating magnetoresistance in silver chalcogenides and potentially in other disordered conductors. Our method may be used to design the magnetoresistive response of a microfabricated array.Comment: 12 pages, 13 figures. Minor typos correcte

    The specificity and patterns of staining in human cells and tissues of p16INK4a antibodies demonstrate variant antigen binding

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    The validity of the identification and classification of human cancer using antibodies to detect biomarker proteins depends upon antibody specificity. Antibodies that bind to the tumour-suppressor protein p16INK4a are widely used for cancer diagnosis and research. In this study we examined the specificity of four commercially available anti-p16INK4a antibodies in four immunological applications. The antibodies H-156 and JC8 detected the same 16 kDa protein in western blot and immunoprecipitation tests, whereas the antibody F-12 did not detect any protein in western blot analysis or capture a protein that could be recognised by the H-156 antibody. In immunocytochemistry tests, the antibodies JC8 and H-156 detected a predominately cytoplasmic localised antigen, whose signal was depleted in p16INK4a siRNA experiments. F-12, in contrast, detected a predominately nuclear located antigen and there was no noticeable reduction in this signal after siRNA knockdown. Furthermore in immunohistochemistry tests, F-12 generated a different pattern of staining compared to the JC8 and E6H4 antibodies. These results demonstrate that three out of four commercially available p16INK4a antibodies are specific to, and indicate a mainly cytoplasmic localisation for, the p16INK4a protein. The F-12 antibody, which has been widely used in previous studies, gave different results to the other antibodies and did not demonstrate specificity to human p16INK4a. This work emphasizes the importance of the validation of commercial antibodies, aside to the previously reported use, for the full verification of immunoreaction specificity

    Anthocyanins do not influence long-chain n-3 fatty acid status:Studies in cells, rodents and humans

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    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, α-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with α-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status

    Embracing the Market: Entry into Self-Employment in Transitional China, 1978-1996

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    This paper introduces labor market transition as an intervening process by which the macro institutional transition to a market economy alters social stratification outcome. Rather than directly addressing income distribution, it examines the pattern of workers’ entry into self-employment in reform-era China (1978-1996), focusing on rural-urban differences and the temporal trend. Analyses of data from a national representative survey in China show that education, party membership and cadre status all deter urban workers’ entry into self-employment, while education promotes rural workers’ entry into self-employment. As marketization proceeds, the rate of entry into self-employment increases in both rural and urban China, but urban workers are increasingly more likely to take advantages of the new market opportunities. In urban China, college graduates and cadres are still less likely to be involved in self-employment, but they are becoming more likely to do so in the later phase of reform. The diversity of transition scenarios is attributed to rural-urban differences in labor market structures.http://deepblue.lib.umich.edu/bitstream/2027.42/39897/3/wp512.pd

    Interaction and uptake of exosomes by ovarian cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Exosomes consist of membrane vesicles that are secreted by several cell types, including tumors and have been found in biological fluids. Exosomes interact with other cells and may serve as vehicles for the transfer of protein and RNA among cells.</p> <p>Methods</p> <p>SKOV3 exosomes were labelled with carboxyfluoresceine diacetate succinimidyl-ester and collected by ultracentrifugation. Uptake of these vesicles, under different conditions, by the same cells from where they originated was monitored by immunofluorescence microscopy and flow cytometry analysis. Lectin analysis was performed to investigate the glycosylation properties of proteins from exosomes and cellular extracts.</p> <p>Results</p> <p>In this work, the ovarian carcinoma SKOV3 cell line has been shown to internalize exosomes from the same cells via several endocytic pathways that were strongly inhibited at 4°C, indicating their energy dependence. Partial colocalization with the endosome marker EEA1 and inhibition by chlorpromazine suggested the involvement of clathrin-dependent endocytosis. Furthermore, uptake inhibition in the presence of 5-ethyl-N-isopropyl amiloride, cytochalasin D and methyl-beta-cyclodextrin suggested the involvement of additional endocytic pathways. The uptake required proteins from the exosomes and from the cells since it was inhibited after proteinase K treatments. The exosomes were found to be enriched in specific mannose- and sialic acid-containing glycoproteins. Sialic acid removal caused a small but non-significant increase in uptake. Furthermore, the monosaccharides D-galactose, α-L-fucose, α-D-mannose, D-N-acetylglucosamine and the disaccharide β-lactose reduced exosomes uptake to a comparable extent as the control D-glucose.</p> <p>Conclusions</p> <p>In conclusion, exosomes are internalized by ovarian tumor cells via various endocytic pathways and proteins from exosomes and cells are required for uptake. On the other hand, exosomes are enriched in specific glycoproteins that may constitute exosome markers. This work contributes to the knowledge about the properties and dynamics of exosomes in cancer.</p
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