13,457 research outputs found

    Asymptotically scale-invariant occupancy of phase space makes the entropy Sq extensive

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    Phase space can be constructed for NN equal and distinguishable subsystems that could be (probabilistically) either {\it weakly} (or {\it "locally"}) correlated (e.g., independent, i.e., uncorrelated), or {\it strongly} (or {\it globally}) correlated. If they are locally correlated, we expect the Boltzmann-Gibbs entropy SBGkipilnpiS_{BG} \equiv -k \sum_i p_i \ln p_i to be {\it extensive}, i.e., SBG(N)NS_{BG}(N)\propto N for NN \to\infty. In particular, if they are independent, SBGS_{BG} is {\it strictly additive}, i.e., SBG(N)=NSBG(1),NS_{BG}(N)=N S_{BG}(1), \forall N. However, if the subsystems are globally correlated, we expect, for a vast class of systems, the entropy Sqk[1ipiq]/(q1)S_q\equiv k [1- \sum_i p_i^q]/(q-1) (with S1=SBGS_1=S_{BG}) for some special value of q1q\ne1 to be the one which extensive (i.e., Sq(N)NS_q(N)\propto N for NN \to\infty).Comment: 15 pages, including 9 figures and 8 Tables. The new version is considerably enlarged with regard to the previous ones. New examples and new references have been include

    Socioeconomic determinants of inflammation and neuroendocrine activity: A longitudinal analysis of compositional and contextual effects

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    Socioeconomic determinants are well-established modulators of inflammation and neuroendocrine activity. Less clear is whether neighbourhood-contextual or individual-compositional factors are more closely associated with gradients in these biomarkers. Here, we examine how immune and neuroendocrine activity are cross-sectionally and longitudinally nested in meso-level socioeconomic characteristics. Participants, male and female, aged ≥50, were recruited from the English Longitudinal Study of Ageing (ELSA). Neighbourhood (Index of Multiple Deprivation [IMD]) and individual (Wealth/Education/Occupational Social Class [Occupation]) factors were drawn from wave 4 (baseline; 2008). Immune and neuroendocrine biomarkers (indexed by C-reactive protein [CRP; n = 3,968]; fibrinogen [n = 3,932]; white blood cell counts [WBCC; n = 4,022]; insulin-like growth factor-1 [IGF-1; n = 4,056]) were measured at baseline and 4-years later (wave 6; 2012). Covariates at baseline included demographic, clinical, and lifestyle variables. Lower socioeconomic status was associated with heighted inflammation and lower neuroendocrine activity unadjusted both cross-sectionally and longitudinally. With few exceptions, cross-sectional associations remained significant after full adjustment. Prospectively, low IMD remained associated with higher CRP and WBCC; wealth with WBCC; and education and occupation with fibrinogen and WBCC. IMD-biomarker associations were reduced when wealth was simultaneously taken into account. Lifestyle accounted for the greatest variance in associations between socioeconomic indicators and inflammation (≤42.11%), but demographics were more salient to neuroendocrine activity (≤88.46%). Neighbourhood-contextual factors were stronger indicators of aberrant biomarker activity than individual-compositional factors in cross-sectional analyses but were largely explained by wealth differences prospectively. Therefore, immune and neuroendocrine changes depended on the composition of the population living in an area, rather than the area itself

    Aeropalynological Investigation of the University of Ilorin, Ilorin, Nigeria

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    Hay fever allergy could either be from pollen or fungi spores. Using theHirst model of pollen trap, pollen buckets were constructed; with pollen trap solutions inside them, they were placed in specific locations in the  University of Ilorin for four months (December 2012/January 2013 to  March/April 2013). Using acetolysis reaction, pollens and spores were  recovered from the trap solution and were analyzed and identified in the microscope. Pollen/spore were counted and compared with meteorologicalparameters i.e. rainfall, sunshine, wind speed, humidity, and temperature. It was observed that pollen/spore concentrations were influenced by these meteorological factors. Hence there is need for us to always determine the amount of these pollen/spore concentrations all year round as it will help to predict the vegetation of a given area as well as helping hay fever sufferers manage their allergies effectively. ©JASEMKEYWORDS: Hey fever, meteorological parameters, pollens, spores, climate, University of Ilorin

    Systemic inflammation and emotional responses during the COVID-19 pandemic

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    The impact of the COVID-19 pandemic on population mental health is of global concern. Inflammatory processes are thought to contribute to mental ill-health, but their role in experiences of psychological distress during the pandemic has not been investigated. We tested the hypothesis that elevated inflammatory biomarkers (high-sensitivity plasma C-reactive protein [CRP] and plasma fibrinogen) measured pre-pandemic would be positively predictive of increased depressive symptoms experienced during the pandemic. Data were analysed from the English Longitudinal Study of Ageing (ELSA), with 3574 individuals aged >50 for CRP and 3314 for fibrinogen measured in waves 8 (2016/17) or 9 (2018/19). Depressive symptoms were measured with a short version of the Centre for Epidemiological Studies Depression Scale (CES-D) pre-pandemic (2016-2019) and during the pandemic (June/July 2020). Participants with higher baseline CRP concentrations had 40% higher odds of developing depressive symptoms during the pandemic (ORadjusted = 1.40, 95% CI 1.12-1.73, p = 0.003) after full adjustment. Fibrinogen concentrations were also associated with depressive symptoms during the pandemic (ORadjusted = 1.23, 95% CI 1.04-1.46, p = 0.019), but this association was no longer significant after controlling for lifestyle factors (smoking status, alcohol consumption and physical activity). In this large population study, systemic inflammation measured 1-3 years pre-pandemic was associated with greater depressed mood during the early months of the pandemic. This finding is consistent with the hypothesis that higher levels of inflammation increase the vulnerability of older people to impaired mental health in the presence of the widespread stress of the COVID-19 pandemic

    RELIABILITY ASSESSMENT OF STRINGERS SPACINGS IN BRIDGES AS FUNCTION OF TIMBER PROPERTIES

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    This presentation accounts for established functions of stringer spacing of major Nigerian woods when used as bridge decks. It entails stochastic evaluation of bridge wood decks with absolute regards to the spacing of supporting stringers. A timber bridge deck is modelled on timber stringers in accordance with current specifications as outline in AASHTO LRFD (2010), to represent real life experiment in order to depict the structural behaviour of Nigerian timbers when used for bridge decks. This model is then subjected to some degree of entropy using Advance Second Moment Reliability Assessment (ASMRA) method, which is subsequently analysed using JAVA library with the help of Flanagan polynomial. The concept of ASMRA with Flanagan polynomial returns optimum output values for any input array of data along the input normal distribution curve. Taking Lophira alata (EKKI), Afzelia bipindensis (APA),Chlorophora  exceisa (IROKO) and Mitragyna ciliate (ABURA) to represent N1, N2, N3, and N4 classes of Nigerian timber suitable for bridge decks, convincingly, it was established that, stringer spacing, strength classes, timber thicknesses and width are some of the major factors among others influencing the structural behaviour of Nigerian timber species used for bridge decks. These data are treated as random variables to generate relative optimum values which, are used to predict the relationship between stringer spacing as a dependent variable on other variables using Analysis of Variance (ANOVA) and multiple Regression line analysis. For the considered timber species, it was observed that large percentages, (R2 ≌ 1 that is  100% for EKKI, APA, IROKO and ABURA of the variation in the dependent variable (stringer spacing) is explained by the independent variables (strength classes, timber thicknesses, timber width, plank deck unit weight, unit weight of surfacing material, lane load, thickness of surfacing material  and reliability indices) which are all good fit. Also all the predicted regression lines are reliable and statistically significant as the significance F, (3.59709E-05 for EKKI, 5.58768E-05 for APA, 3.59709E-05 for IROKO and 8.55563E-05 for ABURA) are all less than 0.05. Thus, these established relationships will help in future forecast of stringer spacing for bridge deck design and analysis within acceptable structural reliability indices which are statistically significant (and are all within acceptable values ≤0.05)  http://dx.doi.org/10.4314/njt.v35i2.1

    Tunable Polaronic Conduction in Anatase TiO2

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    Oxygen vacancies created in anatase TiO2 by UV photons (80–130 eV) provide an effective electron-doping mechanism and induce a hitherto unobserved dispersive metallic state. Angle resolved photoemission reveals that the quasiparticles are large polarons. These results indicate that anatase can be tuned from an insulator to a polaron gas to a weakly correlated metal as a function of doping and clarify the nature of conductivity in this material.open1192sciescopu

    Absorbate-Induced Piezochromism in a Porous Molecular Crystal

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    Atmospherically stable porous frameworks and materials are interesting for heterogeneous solid–gas applications. One motivation is the direct and selective uptake of pollutant/hazardous gases, where the material produces a measurable response in the presence of the analyte. In this report, we present a combined experimental and theoretical rationalization for the piezochromic response of a robust and porous molecular crystal built from an extensively fluorinated trispyrazole. The electronic response of the material is directly determined by analyte uptake, which provokes a subtle lattice contraction and an observable bathochromic shift in the optical absorption onset. Selectivity for fluorinated absorbates is demonstrated, and toluene is also found to crystallize within the pore. Furthermore, we demonstrate the application of electronic structure calculations to predict a physicochemical response, providing the foundations for the design of electronically tunable porous solids with the chemical properties required for development of novel gas-uptake media

    Nonlinear Dynamics in Gene Regulation Promote Robustness and Evolvability of Gene Expression Levels

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    This is the final version of the article. Available from Public Library of Science via the DOI in this record.Cellular phenotypes underpinned by regulatory networks need to respond to evolutionary pressures to allow adaptation, but at the same time be robust to perturbations. This creates a conflict in which mutations affecting regulatory networks must both generate variance but also be tolerated at the phenotype level. Here, we perform mathematical analyses and simulations of regulatory networks to better understand the potential trade-off between robustness and evolvability. Examining the phenotypic effects of mutations, we find an inverse correlation between robustness and evolvability that breaks only with nonlinearity in the network dynamics, through the creation of regions presenting sudden changes in phenotype with small changes in genotype. For genotypes embedding low levels of nonlinearity, robustness and evolvability correlate negatively and almost perfectly. By contrast, genotypes embedding nonlinear dynamics allow expression levels to be robust to small perturbations, while generating high diversity (evolvability) under larger perturbations. Thus, nonlinearity breaks the robustness-evolvability trade-off in gene expression levels by allowing disparate responses to different mutations. Using analytical derivations of robustness and system sensitivity, we show that these findings extend to a large class of gene regulatory network architectures and also hold for experimentally observed parameter regimes. Further, the effect of nonlinearity on the robustness-evolvability trade-off is ensured as long as key parameters of the system display specific relations irrespective of their absolute values. We find that within this parameter regime genotypes display low and noisy expression levels. Examining the phenotypic effects of mutations, we find an inverse correlation between robustness and evolvability that breaks only with nonlinearity in the network dynamics. Our results provide a possible solution to the robustness-evolvability trade-off, suggest an explanation for the ubiquity of nonlinear dynamics in gene expression networks, and generate useful guidelines for the design of synthetic gene circuits.This work was funded by the UK Engineering and Physical Sciences Research Council, grant number EP/I017445/1

    Article size distribution and control on Bitumen saturation of some Tar Sand Deposits in parts of South-Western Nigeria

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    Sedimentological analysis of some Afowo oil sands was carried out with the aim of characterising the reservoirs vis-à-vis their bitumen saturation and recovery efficiencies. Fourty-four samples of tar sands of the Afowo formation (collected at three different localities namely; Idiobilayo, Idiopopo and Igbotako) were subjected to granulometric and petrological analyses to determine the particle size distribution as well as other textural characteristics. The bitumen saturation analysis was carried out with the use of toluene. The result of sedimentological and particle size distribution studies showed that the sands are medium grained, moderately sorted and mesokurtic. The grain morphology can be described as having low to high sphericity, with shapes generally sub-angular to sub-rounded indicating a fairly long period of transportation. The result of bitumen saturation analysis showed that both Idiobilayo and Idiopopo oil sands have an average oil saturation of 17.2% and 16.9% respectively, while Igbotako sands have an average oil saturation of 12.3%. Consequently, Idiobilayo and Idiopopo oil sands deposits are therefore expected to have better reservoir quantities and possibly good oil recovery efficiencies. Keywords: Article size, distribution, Bitumen, Tar Sand Deposits, South-western Nigeria.Global Journal of Pure and Applied Sciences Vol. 14 (3) 2008: pp. 307-31
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