6,289 research outputs found
The impact of a high versus a low glycaemic index breakfast cereal meal on verbal episodic memory in healthy adolescents
In this study, healthy adolescents consumed a) a low glycaemic index (G.I.) breakfast cereal meal, or b) a high G.I. breakfast cereal meal, before completing a test of verbal episodic memory in which the memory materials were encoded under conditions of divided attention. Analysis of remembering/forgetting indices revealed that the High G.I. breakfast group remembered significantly more items relative to the Low G.I. breakfast group after a long delay. The superior performance observed in the High G.I. group, relative to the Low G.I. group, may be due to the additional glucose availability provided by the high G.I. meal at the time of memory encoding. This increased glucose availability may be necessary for effective encoding under dual task conditions
White Matter Hyperintensity Associations with Cerebral Blood Flow in Elderly Subjects Stratified by Cerebrovascular Risk
Objective: This study aims to add clarity to the relationship between deep and periventricular brain white matter hyperintensities (WMHs), cerebral blood flow (CBF), and cerebrovascular risk in older persons. Methods: Deep white matter hyperintensity (dWMH) and periventricular white matter hyperintensity (pWMH) and regional gray matter (GM) and white matter (WM) blood flow from arterial spin labeling were quantified from magnetic resonance imaging scans of 26 cognitively normal elderly subjects stratified by cerebrovascular disease (CVD) risk. Fluidattenuated inversion recovery images were acquired using a high-resolution 3-dimensional (3-D) sequence that reduced partial volume effects seen with slicebased techniques. Results: dWMHs but not pWMHs were increased in patients at high risk of CVD; pWMHs but not dWMHs were associated with decreased regional cortical (GM) blood flow. We also found that blood flow in WM is decreased in regions of both pWMH and dWMH, with a greater degree of decrease in pWMH areas. Conclusions: WMHs are usefully divided into dWMH and pWMH regions because they demonstrate differential effects. 3-D regional WMH volume is a potentially valuable marker for CVD based on associations with cortical CBF and WM CBF
A provisional database for the silicon content of foods in the United Kingdom
Si may play an important role in bone formation and connective tissue metabolism. Although biological interest in this element has recently increased, limited literature exists on the Si content of foods. To further our knowledge and understanding of the relationship between dietary Si and human health, a reliable food composition database, relevant for the UK population, is required. A total of 207 foods and beverages, commonly consumed in the UK, were analysed for Si content. Composite samples were analysed using inductively coupled plasma–optical emission spectrometry following microwave-assisted digestion with nitric acid and H2O2. The highest concentrations of Si were found in cereals and cereal products, especially less refined cereals and oat-based products. Fruit and vegetables were highly variable sources of Si with substantial amounts present in Kenyan beans, French beans, runner beans, spinach, dried fruit, bananas and red lentils, but undetectable amounts in tomatoes, oranges and onions. Of the beverages, beer, a macerated whole-grain cereal product, contained the greatest level of Si, whilst drinking water was a variable source with some mineral waters relatively high in Si. The present study provides a provisional database for the Si content of UK foods, which will allow the estimation of dietary intakes of Si in the UK population and investigation into the role of dietary Si in human health.<br /
Dissociation of Automatic and Strategic Lexical-semantics: Functional Magnetic Resonance Imaging Evidence for Differing Roles of Multiple Frontotemporal Regions
Behavioral research has demonstrated three major components of the lexical-semantic processing system: automatic activation of semantic representations, strategic retrieval of semantic representations, and inhibition of competitors. However, these component processes are inherently conflated in explicit lexical-semantic decision tasks typically used in functional magnetic resonance imaging (fMRI) research. Here, we combine the logic of behavioral priming studies and the neurophysiological phenomenon of fMRI priming to dissociate the neural bases of automatic and strategic lexical-semantic processes across a series of three studies. A single lexical decision task was used in all studies, with stimulus onset asynchrony or linguistic relationship between prime and target being manipulated. Study 1 demonstrated automatic semantic priming in the left mid-fusiform gyrus (mid-FFG) and strategic semantic priming in five regions: left middle temporal gyrus (MTG), bilateral anterior cingulate, anterior left inferior prefrontal cortex (aLIPC), and posterior LIPC (pLIPC). These priming effects were explored in more detail in two subsequent studies. Study 2 replicated the automatic priming effect in mid-FFG and demonstrated that automatic priming in this region is preferential for the semantic domain. Study 3 demonstrated a neural dissociation in regions contributing to the strategic semantic priming effect. Strategic semantic facilitation was observed in the aLIPC and MTG, whereas strategic semantic inhibition was observed in the pLIPC and anterior cingulate. These studies provide reproducible evidence for a neural dissociation between three well established components of the lexical-semantic processing system
ARIADNE - A novel optical LArTPC: technical design report and initial characterisation using a secondary beam from the CERN PS and cosmic muons
ARIADNE is a 1-ton (330 kg fiducial mass) dual-phase liquid argon (LAr) time
projection chamber (TPC) featuring a novel optical readout. Four
electron-multiplying charge-coupled device (EMCCD) cameras are mounted
externally, and these capture the secondary scintillation light produced in the
holes of a thick electron gas multiplier (THGEM). Track reconstruction using
this novel readout approach is demonstrated. Optical readout has the potential
to be a cost effective alternative to charge readout in future LArTPCs. In this
paper, the technical design of the detector is detailed. Results of mixed
particle detection using a secondary beam from the CERN PS (representing the
first ever optical images of argon interactions in a dual-phase LArTPC at a
beamline) and cosmic muon detection at the University of Liverpool are also
presented.Comment: 58 pages, 40 figures. Changes from previous version based on
pre-publication review: improved quality of various figures, improved clarity
of some definitions and reduced longer sentences for better readability,
fixed typos and formatting error
Genotype-specific effects of ericoid mycorrhizae on floral traits and reproduction in Vaccinium corymbosum
American Journal of Botany is published by Wiley Periodicals, Inc. on behalf of the Botanical Society of America. Premise: Most plants interact with mycorrhizal fungi and animal pollinators simultaneously. Yet, whether mycorrhizae affect traits important to pollination remains poorly understood and may depend on the match between host and fungal genotypes. Here, we examined how ericoid mycorrhizal fungi affected flowering phenology, floral traits, and reproductive success, among eight genotypes of highbush blueberry, Vaccinium corymbosum (Ericaceae). We asked three overarching questions: (1) Do genotypes differ in response to inoculation? (2) How does inoculation affect floral and flowering traits? (3) Are inoculated plants more attractive to pollinators and less pollen limited than non-inoculated plants of the same genotype?. Methods: To examine these questions, we experimentally inoculated plants with ericoid mycorrhizal fungi, grew the plants in the field, and measured flowering and floral traits over 2 years. In year 2, we conducted a hand-pollination experiment to test whether plants differed in pollen limitation. Results: Inoculated plants had significantly higher levels of colonization for some genotypes, and there were significant floral trait changes in inoculated plants for some genotypes as well. On average, inoculated plants produced significantly larger floral displays, more fruits per inflorescence, and heavier fruits with lower sugar content, than non-inoculated, control plants. Hand pollination enhanced the production of fruits, and fruit mass, for non-inoculated plants but not for those that were inoculated. Conclusions: Our results demonstrate that inoculation with ericoid mycorrhizal fungi enhanced flowering and altered investment in reproduction in genotype-specific ways. These findings underscore the importance of examining belowground symbionts and genotype-specific responses in their hosts to fully understand the drivers of aboveground interactions
The Role of Racial Identity and Implicit Racial Bias in Self-Reported Racial Discrimination: Implications for Depression Among African American Men
Racial discrimination is conceptualized as a psychosocial stressor that has negative implications for mental health. However, factors related to racial identity may influence whether negative experiences are interpreted as instances of racial discrimination and subsequently reported as such in survey instruments, particularly given the ambiguous nature of contemporary racism. Along these lines, dimensions of racial identity may moderate associations between racial discrimination and mental health outcomes. This study examined relationships between racial discrimination, racial identity, implicit racial bias, and depressive symptoms among African American men between 30 and 50 years of age (n = 95). Higher racial centrality was associated with greater reports of racial discrimination, while greater implicit anti-Black bias was associated with lower reports of racial discrimination. In models predicting elevated depressive symptoms, holding greater implicit anti-Black bias in tandem with reporting lower racial discrimination was associated with the highest risk. Results suggest that unconscious as well as conscious processes related to racial identity are important to consider in measuring racial discrimination, and should be integrated in studies of racial discrimination and mental health
Reduction of low- and high-grade cervical abnormalities associated with high uptake of the HPV bivalent vaccine in Scotland
In Scotland, a national HPV immunisation programme began in 2008 for 12-13 year olds, with a catch-up campaign from 2008-2011 for those under the age of 18. To monitor the impact of HPV immunisation on cervical disease at the population level, a programme of national surveillance was established. We analysed colposcopy data from a cohort of women born between 1988-1992 who entered the Scottish Cervical Screening Programme (SCSP) and were aged 20-21 in 2008-2012. By linking datasets from the SCSP and colposcopy services, we observed a significant reduction in diagnoses of cervical intraepithelial neoplasia 1 (CIN 1) (RR 0.71, 95% CI 0.58 to 0.87, p=0.0008), CIN 2 (RR 0.5, 95% CI 0.4, 0.63, p<0.0001) and CIN 3 (RR 0.45, 95% CI 0.35 to 0.58, p< 0.0001) for women who received 3 doses of vaccine compared with unvaccinated women. To our knowledge, this is one of the first studies to show a reduction of low and high grade cervical intraepithelial neoplasia associated with high uptake of the HPV bivalent vaccine at the population level. These data are very encouraging for countries that have achieved high HPV vaccine uptake
A Comparison of U. S. and European University-Industry Relations in the Life Sciences
We draw on diverse data sets to compare the institutional organization of upstream life science research across the United States and Europe. Understanding cross-national differences in the organization of innovative labor in the life sciences requires attention to the structure and evolution of biomedical networks involving public research organizations (universities, government laboratories, nonprofit research institutes, and research hospitals), science-based biotechnology firms, and multinational pharmaceutical corporations. We use network visualization methods and correspondence analyses to demonstrate that innovative research in biomedicine has its origins in regional clusters in the United States and in European nations. But the scientific and organizational composition of these regions varies in consequential ways. In the United States, public research organizations and small firms conduct R&D across multiple therapeutic areas and stages of the development process. Ties within and across these regions link small firms and diverse public institutions, contributing to the development of a robust national network. In contrast, the European story is one of regional specialization with a less diverse group of public research organizations working in a smaller number of therapeutic areas. European institutes develop local connections to small firms working on similar scientific problems, while cross-national linkages of European regional clusters typically involve large pharmaceutical corporations. We show that the roles of large and small firms differ in the United States and Europe, arguing that the greater heterogeneity of the U. S. system is based on much closer integration of basic science and clinical development
Spatial patterns and scale freedom in a Prisoner's Dilemma cellular automata with Pavlovian strategies
A cellular automaton in which cells represent agents playing the Prisoner's
Dilemma (PD) game following the simple "win-stay, loose-shift" strategy is
studied. Individuals with binary behavior, such as they can either cooperate
(C) or defect (D), play repeatedly with their neighbors (Von Neumann's and
Moore's neighborhoods). Their utilities in each round of the game are given by
a rescaled payoff matrix described by a single parameter Tau, which measures
the ratio of 'temptation to defect' to 'reward for cooperation'. Depending on
the region of the parameter space Tau, the system self-organizes - after a
transient - into dynamical equilibrium states characterized by different
definite fractions of C agents (2 states for the Von Neumann neighborhood and 4
for Moore neighborhood). For some ranges of Tau the cluster size distributions,
the power spectrums P(f) and the perimeter-area curves follow power-law
scalings. Percolation below threshold is also found for D agent clusters. We
also analyze the asynchronous dynamics version of this model and compare
results.Comment: Accepted for publication in JSTA
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