Sample records for maximum flow declination

  1. The inverse maximum dynamic flow problem

    BAGHERIAN; Mehri


    We consider the inverse maximum dynamic flow (IMDF) problem.IMDF problem can be described as: how to change the capacity vector of a dynamic network as little as possible so that a given feasible dynamic flow becomes a maximum dynamic flow.After discussing some characteristics of this problem,it is converted to a constrained minimum dynamic cut problem.Then an efficient algorithm which uses two maximum dynamic flow algorithms is proposed to solve the problem.

  2. Group differences in measures of voice production and revised values of maximum airflow declination rate.

    Perkell, J S; Hillman, R E; Holmberg, E B


    In previous reports, aerodynamic and acoustic measures of voice production were presented for groups of normal male and female speakers [Holmberg et al., J. Acoust. Soc. Am. 84, 511-529 (1988); J. Voice 3, 294-305 (1989)] that were used as norms in studies of voice disorders [Hillman et al., J. Speech Hear. Res. 32, 373-392 (1989); J. Voice 4, 52-63 (1990)]. Several of the measures were extracted from glottal airflow waveforms that were derived by inverse filtering a high-time-resolution oral airflow signal. Recently, the methods have been updated and a new study of additional subjects has been conducted. This report presents previous (1988) and current (1993) group mean values of sound pressure level, fundamental frequency, maximum airflow declination rate, ac flow, peak flow, minimum flow, ac-dc ratio, inferred subglottal air pressure, average flow, and glottal resistance. Statistical tests indicate overall group differences and differences for values of several individual parameters between the 1988 and 1993 studies. Some inter-study differences in parameter values may be due to sampling effects and minor methodological differences; however, a comparative test of 1988 and 1993 inverse filtering algorithms shows that some lower 1988 values of maximum flow declination rate were due at least in part to excessive low-pass filtering in the 1988 algorithm. The observed differences should have had a negligible influence on the conclusions of our studies of voice disorders.

  3. A polynomial algorithm for abstract maximum flow

    McCormick, S.T. [Univ. of British Columbia, Vancouver, British Columbia (Canada)


    Ford and Fulkerson`s original 1956 max flow/min cut paper formulated max flow in terms of flows on paths, rather than the more familiar flows on arcs. In 1974 Hoffman pointed out that Ford and Fulkerson`s original proof was quite abstract, and applied to a wide range of max flow-like problems. In this abstract model we have capacitated elements, and linearly ordered subsets of elements called paths. When two paths share an element ({open_quote}cross{close_quote}), then there must be a path that is a subset of the first path up to the cross, and a subset of the second path after the cross. (Hoffman`s generalization of) Ford and Fulkerson`s proof showed that the max flow/min cut theorem still holds under this weak assumption. However, this proof is non-constructive. To get an algorithm, we assume that we have an oracle whose input is an arbitrary subset of elements, and whose output is either a path contained in that subset, or the statement that no such path exists. We then use complementary slackness to show how to augment any feasible set of path flows to a set with a strictly larger total flow value using a polynomial number of calls to the oracle. Then standard scaling techniques yield an overall polynomial algorithm for finding both a max flow and a min cut. Hoffman`s paper actually considers a sort of supermodular objective on the path flows, which allows him to include transportation problems and thus rain-cost flow in his frame-work. We also discuss extending our algorithm to this more general case.

  4. The directed flow maximum near cs = 0

    Brachmann, J.; Dumitru, A.; Stöcker, H.; Greiner, W.


    We investigate the excitation function of quark-gluon plasma formation and of directed in-plane flow of nucleons in the energy range of the BNL-AGS and for the E {Lab/kin} = 40 AGeV Pb + Pb collisions performed recently at the CERN-SPS. We employ the three-fluid model with dynamical unification of kinetically equilibrated fluid elements. Within our model with first-order phase transition at high density, droplets of QGP coexisting with hadronic matter are produced already at BNL-AGS energies, E {Lab/kin} ≃ 10 AGeV. A substantial decrease of the isentropic velocity of sound, however, requires higher energies, E {Lab/kin} ≃ 0 AGeV. We show the effect on the flow of nucleons in the reaction plane. According to our model calculations, kinematic requirements and EoS effects work hand-in-hand at E {Lab/kin} = 40 AGeV to allow the observation of the dropping velocity of sound via an increase of the directed flow around midrapidity as compared to top BNL-AGS energy.

  5. A Fast Parametric Maximum Flow Algorithm. Revision,


    26]. ". N. Perfect sharing arises in a network transmission problem studied by Itai and Rodeh [21] and 1 Gusfield [17] and in a network...the network transmission scheduling problem described below. Another application will arise in Section 4.2. Scheduling transmissions. Itai and Rodeh...constructed from the flow in 0(m) time as described in [21]. Itai and Rodeh proposed two 22 "-N., -- %’%’ % %""’ . ,’ ""€"" ",. . -",/a

  6. P wave dispersion and maximum P wave duration are independently associated with rapid renal function decline.

    Ho-Ming Su

    Full Text Available The P wave parameters measured by 12-lead electrocardiogram (ECG are commonly used as noninvasive tools to assess for left atrial enlargement. There are limited studies to evaluate whether P wave parameters are independently associated with decline in renal function. Accordingly, the aim of this study is to assess whether P wave parameters are independently associated with progression to renal end point of ≥25% decline in estimated glomerular filtration rate (eGFR. This longitudinal study included 166 patients. The renal end point was defined as ≥25% decline in eGFR. We measured two ECG P wave parameters corrected by heart rate, i.e. corrected P wave dispersion (PWdisperC and corrected P wave maximum duration (PWdurMaxC. Heart function and structure were measured from echocardiography. Clinical data, P wave parameters, and echocardiographic measurements were compared and analyzed. Forty-three patients (25.9% reached renal end point. Kaplan-Meier curves for renal end point-free survival showed PWdisperC > median (63.0 ms (log-rank P = 0.004 and PWdurMaxC > median (117.9 ms (log-rank P<0.001 were associated with progression to renal end point. Multivariate forward Cox-regression analysis identified increased PWdisperC (hazard ratio [HR], 1.024; P = 0.001 and PWdurMaxC (HR, 1.029; P = 0.001 were independently associated with progression to renal end point. Our results demonstrate that increased PWdisperC and PWdurMaxC were independently associated with progression to renal end point. Screening patients by means of PWdisperC and PWdurMaxC on 12 lead ECG may help identify a high risk group of rapid renal function decline.

  7. The inverse maximum flow problem with lower and upper bounds for the flow

    Deaconu Adrian


    Full Text Available The general inverse maximum flow problem (denoted GIMF is considered, where lower and upper bounds for the flow are changed so that a given feasible flow becomes a maximum flow and the distance (considering l1 norm between the initial vector of bounds and the modified vector is minimum. Strongly and weakly polynomial algorithms for solving this problem are proposed. In the paper it is also proved that the inverse maximum flow problem where only the upper bound for the flow is changed (IMF is a particular case of the GIMF problem.

  8. Improved Minimum Cuts and Maximum Flows in Undirected Planar Graphs

    Italiano, Giuseppe F


    In this paper we study minimum cut and maximum flow problems on planar graphs, both in static and in dynamic settings. First, we present an algorithm that given an undirected planar graph computes the minimum cut between any two given vertices in O(n log log n) time. Second, we show how to achieve the same O(n log log n) bound for the problem of computing maximum flows in undirected planar graphs. To the best of our knowledge, these are the first algorithms for those two problems that break the O(n log n) barrier, which has been standing for more than 25 years. Third, we present a fully dynamic algorithm that is able to maintain information about minimum cuts and maximum flows in a plane graph (i.e., a planar graph with a fixed embedding): our algorithm is able to insert edges, delete edges and answer min-cut and max-flow queries between any pair of vertices in O(n^(2/3) log^3 n) time per operation. This result is based on a new dynamic shortest path algorithm for planar graphs which may be of independent int...

  9. Properties and geoeffectiveness of magnetic clouds in the rising, maximum and early declining phases of solar cycle 23

    K. E. J. Huttunen


    Full Text Available The magnetic structure and geomagnetic response of 73 magnetic clouds (MC observed by the WIND and ACE satellites in solar cycle 23 are examined. The results have been compared with the surveys from the previous solar cycles. The preselected candidate MC events were investigated using the minimum variance analysis to determine if they have a flux-rope structure and to obtain the estimation for the axial orientation (θC, φC. Depending on the calculated inclination relative to the ecliptic we divided MCs into "bipolar" (θC<45° and "unipolar" (θC>45°. The number of observed MCs was largest in the early rising phase, although the halo CME rate was still low. It is likely that near solar maximum we did not identify all MCs at 1AU, as they were crossed far from the axis or they had interacted strongly with the ambient solar wind or with other CMEs. The occurrence rate of MCs at 1AU is also modified by the migration of the filament sites on the Sun towards the poles near solar maximum and by the deflection of CMEs towards the equator due to the fast solar wind flow from large polar coronal holes near solar minimum. In the rising phase nearly all bipolar MCs were associated with the rotation of the magnetic field from the south at the leading edge to the north at the trailing edge. The results for solar cycles 21-22 showed that the direction of the magnetic field in the leading portion of the MC starts to reverse at solar maximum. At solar maximum and in the declining phase (2000-2003 we observed several MCs with the rotation from the north to the south. We observed unipolar (i.e. highly inclined MCs frequently during the whole investigated period. For solar cycles 21-22 the majority of MCs identified in the rising phase were bipolar while in the declining phase most MCs were unipolar. The geomagnetic response of a given MC depends greatly on its magnetic structure and the orientation of the sheath

  10. Mapping the MPM maximum flow algorithm on GPUs

    Solomon, Steven; Thulasiraman, Parimala


    The GPU offers a high degree of parallelism and computational power that developers can exploit for general purpose parallel applications. As a result, a significant level of interest has been directed towards GPUs in recent years. Regular applications, however, have traditionally been the focus of work on the GPU. Only very recently has there been a growing number of works exploring the potential of irregular applications on the GPU. We present a work that investigates the feasibility of Malhotra, Pramodh Kumar and Maheshwari's "MPM" maximum flow algorithm on the GPU that achieves an average speedup of 8 when compared to a sequential CPU implementation.

  11. Maximum Flow in Planar Networks with Exponentially Distributed Arc Capacities.


    avoid constructing the dual, are described in Itai and Shiloach P 97 91. In this paper, we consider the maximum flow problem in (st) planar networks...use arc e and lies completely below P. If no such path exists we say P(e) - *. An algorithm tc construct P(e) given P and e is described in Itai and...suggested in Ford and Fulkerson [1956], developed in Berge and Ghouila-Houri [1962] and its time complexity is reduced to 0( IVI log IVI ) by Itai and

  12. Invulnerability of power grids based on maximum flow theory

    Fan, Wenli; Huang, Shaowei; Mei, Shengwei


    The invulnerability analysis against cascades is of great significance in evaluating the reliability of power systems. In this paper, we propose a novel cascading failure model based on the maximum flow theory to analyze the invulnerability of power grids. In the model, node initial loads are built on the feasible flows of nodes with a tunable parameter γ used to control the initial node load distribution. The simulation results show that both the invulnerability against cascades and the tolerance parameter threshold αT are affected by node load distribution greatly. As γ grows, the invulnerability shows the distinct change rules under different attack strategies and different tolerance parameters α respectively. These results are useful in power grid planning and cascading failure prevention.

  13. Maximum speeds and alpha angles of flowing avalanches

    McClung, David; Gauer, Peter


    A flowing avalanche is one which initiates as a slab and, if consisting of dry snow, will be enveloped in a turbulent snow dust cloud once the speed reaches about 10 m/s. A flowing avalanche has a dense core of flowing material which dominates the dynamics by serving as the driving force for downslope motion. The flow thickness typically on the order of 1 -10 m which is on the order of about 1% of the length of the flowing mass. We have collected estimates of maximum frontal speed um (m/s) from 118 avalanche events. The analysis is given here with the aim of using the maximum speed scaled with some measure of the terrain scale over which the avalanches ran. We have chosen two measures for scaling, from McClung (1990), McClung and Schaerer (2006) and Gauer (2012). The two measures are the √H0-;√S0-- (total vertical drop; total path length traversed). Our data consist of 118 avalanches with H0 (m)estimated and 106 with S0 (m)estimated. Of these, we have 29 values with H0 (m),S0 (m)and um (m/s)estimated accurately with the avalanche speeds measured all or nearly all along the path. The remainder of the data set includes approximate estimates of um (m/s)from timing the avalanche motion over a known section of the path where approximate maximum speed is expected and with either H0or S0or both estimated. Our analysis consists of fitting the values of um/√H0--; um/√S0- to probability density functions (pdf) to estimate the exceedance probability for the scaled ratios. In general, we found the best fits for the larger data sets to fit a beta pdf and for the subset of 29, we found a shifted log-logistic (s l-l) pdf was best. Our determinations were as a result of fitting the values to 60 different pdfs considering five goodness-of-fit criteria: three goodness-of-fit statistics :K-S (Kolmogorov-Smirnov); A-D (Anderson-Darling) and C-S (Chi-squared) plus probability plots (P-P) and quantile plots (Q-Q). For less than 10% probability of exceedance the results show that

  14. Depressed pacemaker activity of sinoatrial node myocytes contributes to the age-dependent decline in maximum heart rate

    Larson, Eric D.; St. Clair, Joshua R.; Sumner, Whitney A.; Bannister, Roger A.; Proenza, Cathy


    An inexorable decline in maximum heart rate (mHR) progressively limits human aerobic capacity with advancing age. This decrease in mHR results from an age-dependent reduction in “intrinsic heart rate” (iHR), which is measured during autonomic blockade. The reduced iHR indicates, by definition, that pacemaker function of the sinoatrial node is compromised during aging. However, little is known about the properties of pacemaker myocytes in the aged sinoatrial node. Here, we show that depressed excitability of individual sinoatrial node myocytes (SAMs) contributes to reductions in heart rate with advancing age. We found that age-dependent declines in mHR and iHR in ECG recordings from mice were paralleled by declines in spontaneous action potential (AP) firing rates (FRs) in patch-clamp recordings from acutely isolated SAMs. The slower FR of aged SAMs resulted from changes in the AP waveform that were limited to hyperpolarization of the maximum diastolic potential and slowing of the early part of the diastolic depolarization. These AP waveform changes were associated with cellular hypertrophy, reduced current densities for L- and T-type Ca2+ currents and the “funny current” (If), and a hyperpolarizing shift in the voltage dependence of If. The age-dependent reduction in sinoatrial node function was not associated with changes in β-adrenergic responsiveness, which was preserved during aging for heart rate, SAM FR, L- and T-type Ca2+ currents, and If. Our results indicate that depressed excitability of individual SAMs due to altered ion channel activity contributes to the decline in mHR, and thus aerobic capacity, during normal aging. PMID:24128759

  15. Continuous maximum flow segmentation method for nanoparticle interaction analysis.

    Marak, L; Tankyevych, O; Talbot, H


    In recent years, tomographic three-dimensional reconstruction approaches using electrons rather than X-rays have become popular. Such images produced with a transmission electron microscope make it possible to image nanometre-scale materials in three-dimensional. However, they are also noisy, limited in contrast and most often have a very poor resolution along the axis of the electron beam. The analysis of images stemming from such modalities, whether fully or semiautomated, is therefore more complicated. In particular, segmentation of objects is difficult. In this paper, we propose to use the continuous maximum flow segmentation method based on a globally optimal minimal surface model. The use of this fully automated segmentation and filtering procedure is illustrated on two different nanoparticle samples and provide comparisons with other classical segmentation methods. The main objectives are the measurement of the attraction rate of polystyrene beads to silica nanoparticle (for the first sample) and interaction of silica nanoparticles with large unilamellar liposomes (for the second sample). We also illustrate how precise measurements such as contact angles can be performed.

  16. Maximum flow-based resilience analysis: From component to system

    Jin, Chong; Li, Ruiying; Kang, Rui


    Resilience, the ability to withstand disruptions and recover quickly, must be considered during system design because any disruption of the system may cause considerable loss, including economic and societal. This work develops analytic maximum flow-based resilience models for series and parallel systems using Zobel’s resilience measure. The two analytic models can be used to evaluate quantitatively and compare the resilience of the systems with the corresponding performance structures. For systems with identical components, the resilience of the parallel system increases with increasing number of components, while the resilience remains constant in the series system. A Monte Carlo-based simulation method is also provided to verify the correctness of our analytic resilience models and to analyze the resilience of networked systems based on that of components. A road network example is used to illustrate the analysis process, and the resilience comparison among networks with different topologies but the same components indicates that a system with redundant performance is usually more resilient than one without redundant performance. However, not all redundant capacities of components can improve the system resilience, the effectiveness of the capacity redundancy depends on where the redundant capacity is located. PMID:28545135

  17. Maximum Likelihood Blood Velocity Estimator Incorporating Properties of Flow Physics

    Schlaikjer, Malene; Jensen, Jørgen Arendt


    The aspect of correlation among the blood velocities in time and space has not received much attention in previous blood velocity estimators. The theory of fluid mechanics predicts this property of the blood flow. Additionally, most estimators based on a cross-correlation analysis are limited...... of simulated and in vivo data from the carotid artery. The estimator is meant for two-dimensional (2-D) color flow imaging. The resulting mathematical relation for the estimator consists of two terms. The first term performs a cross-correlation analysis on the signal segment in the radio frequency (RF......)-data under investigation. The flow physic properties are exploited in the second term, as the range of velocity values investigated in the cross-correlation analysis are compared to the velocity estimates in the temporal and spatial neighborhood of the signal segment under investigation. The new estimator...

  18. Maximum entropy analysis of flow and reaction networks

    Niven, Robert K.; Abel, Markus; Schlegel, Michael; Waldrip, Steven H.


    We present a generalised MaxEnt method to infer the stationary state of a flow network, subject to "observable" constraints on expectations of various parameters, as well as "physical" constraints arising from frictional properties (resistance functions) and conservation laws (Kirchhoff laws). The method invokes an entropy defined over all uncertainties in the system, in this case the internal and external flow rates and potential differences. The proposed MaxEnt framework is readily extendable to the analysis of networks with uncertainty in the network structure itself.

  19. Maximum estimates for generalized Forchheimer flows in heterogeneous porous media

    Celik, Emine; Hoang, Luan


    This article continues the study in [4] of generalized Forchheimer flows in heterogeneous porous media. Such flows are used to account for deviations from Darcy's law. In heterogeneous media, the derived nonlinear partial differential equation for the pressure can be singular and degenerate in the spatial variables, in addition to being degenerate for large pressure gradient. Here we obtain the estimates for the L∞-norms of the pressure and its time derivative in terms of the initial and the time-dependent boundary data. They are established by implementing De Giorgi-Moser's iteration in the context of weighted norms with the weights specifically defined by the Forchheimer equation's coefficient functions. With these weights, we prove suitable weighted parabolic Poincaré-Sobolev inequalities and use them to facilitate the iteration. Moreover, local in time L∞-bounds are combined with uniform Gronwall-type energy inequalities to obtain long-time L∞-estimates.

  20. Flow distribution and maximum current density studies in redox flow batteries with a single passage of the serpentine flow channel

    Ke, Xinyou; Alexander, J. Iwan D.; Prahl, Joseph M.; Savinell, Robert F.


    Flow batteries show promise for very large-scale stationary energy storage such as needed for the grid and renewable energy implementation. In recent years, researchers and developers of redox flow batteries (RFBs) have found that electrode and flow field designs of PEM fuel cell (PEMFC) technology can increase the power density and consequently push down the cost of flow battery stacks. In this paper we present a macroscopic model of a typical PEMFC-like RFB electrode-flow field design. The model is a layered system comprised of a single passage of a serpentine flow channel and a parallel underlying porous electrode (or porous layer). The effects of the inlet volumetric flow rate, permeability of the porous layer, thickness of the porous layer and thickness of the flow channel on the flow penetration into the porous layer are investigated. The maximum current density corresponding to stoichiometry is estimated to be 377 mA cm-2 and 724 mA cm-2, which compares favorably with experiments of ∼400 mA cm-2 and ∼750 mA cm-2, for a single layer and three layers of the carbon fiber paper, respectively.

  1. The directed flow maximum near $c_{s} = 0$

    Brachmann, J; Stöcker, H; Greiner, W


    We investigate the excitation function of quark-gluon plasma formation and the rapidity dependence of directed in-plane flow of nucleons in the energy range of the BNL-AGS and for the $E^{kin}_{Lab}=40A$~GeV Pb+Pb collisions performed recently at the CERN-SPS. We employ the three-fluid model with dynamical unification of kinetically equilibrated fluid elements. Within our model with first-order phase transition at high density, droplets of QGP coexisting with hadronic matter are produced already at BNL-AGS energies, $E^{kin}_{Lab}\\simeq 10A$~GeV. A substantial decrease of the isentropic velocity of sound, however, requires higher energies, $E^{kin}_{Lab}\\simeq40A$~GeV. We calculate the response of the directed in-plane momentum per nucleon, $(y)$. According to our model calculations, kinematic requirements and EoS effects work hand-in-hand at $E^{kin}_{Lab}=40A$~GeV to allow the observation of the dropping velocity of sound and of the ``slowly burning'' mixed phase via an {\\em increase} of the directed flow a...

  2. Comparison Between Bayesian and Maximum Entropy Analyses of Flow Networks†

    Steven H. Waldrip


    Full Text Available We compare the application of Bayesian inference and the maximum entropy (MaxEnt method for the analysis of flow networks, such as water, electrical and transport networks. The two methods have the advantage of allowing a probabilistic prediction of flow rates and other variables, when there is insufficient information to obtain a deterministic solution, and also allow the effects of uncertainty to be included. Both methods of inference update a prior to a posterior probability density function (pdf by the inclusion of new information, in the form of data or constraints. The MaxEnt method maximises an entropy function subject to constraints, using the method of Lagrange multipliers,to give the posterior, while the Bayesian method finds its posterior by multiplying the prior with likelihood functions incorporating the measured data. In this study, we examine MaxEnt using soft constraints, either included in the prior or as probabilistic constraints, in addition to standard moment constraints. We show that when the prior is Gaussian,both Bayesian inference and the MaxEnt method with soft prior constraints give the same posterior means, but their covariances are different. In the Bayesian method, the interactions between variables are applied through the likelihood function, using second or higher-order cross-terms within the posterior pdf. In contrast, the MaxEnt method incorporates interactions between variables using Lagrange multipliers, avoiding second-order correlation terms in the posterior covariance. The MaxEnt method with soft prior constraints, therefore, has a numerical advantage over Bayesian inference, in that the covariance terms are avoided in its integrations. The second MaxEnt method with soft probabilistic constraints is shown to give posterior means of similar, but not identical, structure to the other two methods, due to its different formulation.


    Forest stress and decline resulting from increased river flows were investigated in Myakka River State Park (MRSP), Florida, USA. Since 1977, land-use changes around the upper Myakka River watershed have resulted in significant increases in water entering the river, which have...

  4. The Distribution of Maximum Flow with Application to Multi-State Reliability Systems.


    in 0( lVI • JEJ )time, using the max-flow algorithm of Itai and Shiloach (1979). Frank and Frisch (1971) provide a comprehensive discussion of the...maximum flow; for example, taking 0( Ivi log IVI time per replication for a planar network ( Itai and Shiloach 1979). With regard to computing the cell...Edition 8, Houston, Texas. 11. Itai , A. and Y. Shiloach (1979). Maximum flow in planar networks, SIAM J. Comput., 8, 135-150. 12. Kulkarni, V.G. and V. G

  5. Flow regime, temperature, and biotic interactions drive differential declines of trout species under climate change

    Wenger, S.J.; Isaak, D.J.; Luce, C.H.; Neville, H.M.; Fausch, K.D.; Dunham, J.B.; Dauwalter, D.C.; Young, M.K.; Elsner, M.M.; Rieman, B.E.; Hamlet, A.F.; Williams, J.E.


    Broad-scale studies of climate change effects on freshwater species have focused mainly on temperature, ignoring critical drivers such as flow regime and biotic interactions. We use downscaled outputs from general circulation models coupled with a hydrologic model to forecast the effects of altered flows and increased temperatures on four interacting species of trout across the interior western United States (1.01 million km2), based on empirical statistical models built from fish surveys at 9,890 sites. Projections under the 2080s A1B emissions scenario forecast a mean 47% decline in total suitable habitat for all trout, a group of fishes of major socioeconomic and ecological significance. We project that native cutthroat trout Oncorhynchus clarkii, already excluded from much of its potential range by nonnative species, will lose a further 58% of habitat due to an increase in temperatures beyond the species' physiological optima and continued negative biotic interactions. Habitat for nonnative brook trout Salvelinus fontinalis and brown trout Salmo trutta is predicted to decline by 77% and 48%, respectively, driven by increases in temperature and winter flood frequency caused by warmer, rainier winters. Habitat for rainbow trout, Oncorhynchus mykiss, is projected to decline the least (35%) because negative temperature effects are partly offset by flow regime shifts that benefit the species. These results illustrate how drivers other than temperature influence species response to climate change. Despite some uncertainty, large declines in trout habitat are likely, but our findings point to opportunities for strategic targeting of mitigation efforts to appropriate stressors and locations.

  6. Importance of maximum snow accumulation for summer low flows in humid catchments

    Jenicek, M.; Seibert, J.; Zappa, M.; Staudinger, M.; Jonas, T.


    The expected increase of air temperature will increase the ratio of liquid to solid precipitation during winter and, thus decrease the amount of snow, especially in mid-elevation mountain ranges across Europe. The decrease of snow will affect groundwater recharge during spring and might cause low streamflow values in the subsequent summer period. To evaluate these potential climate change impacts, we investigated the effects of inter-annual variations in snow accumulation on summer low flow and addressed the following research questions: (1) how important is snow for summer low flows and how long is the "memory effect" in catchments with different elevations? (2) How sensitive are summer low flows to any change of winter snowpack? To find suitable predictors of summer low flow we used long time series from 14 alpine and pre-alpine catchments in Switzerland and computed different variables quantifying winter and spring snow conditions. We assessed the sensitivity of individual catchments to the change of maximum snow water equivalent (SWEmax) using the non-parametric Theil-Sen approach as well as an elasticity index. In general, the results indicated that maximum winter snow accumulation influenced summer low flow, but could only partly explain the observed inter-annual variations. One other important factor was the precipitation between maximum snow accumulation and summer low flow. When only the years with below average precipitation amounts during this period were considered, the importance of snow accumulation as a predictor of low flows increased. The slope of the regression between SWEmax and summer low flow and the elasticity index both increased with increasing mean catchment elevation. This indicated a higher sensitivity of summer low flow to snow accumulation in alpine catchments compared to lower elevation catchments.

  7. Applying the maximum information principle to cell transmission model of tra-ffic flow

    刘喜敏; 卢守峰


    This paper integrates the maximum information principle with the Cell Transmission Model (CTM) to formulate the velo-city distribution evolution of vehicle traffic flow. The proposed discrete traffic kinetic model uses the cell transmission model to cal-culate the macroscopic variables of the vehicle transmission, and the maximum information principle to examine the velocity distri-bution in each cell. The velocity distribution based on maximum information principle is solved by the Lagrange multiplier method. The advantage of the proposed model is that it can simultaneously calculate the hydrodynamic variables and velocity distribution at the cell level. An example shows how the proposed model works. The proposed model is a hybrid traffic simulation model, which can be used to understand the self-organization phenomena in traffic flows and predict the traffic evolution.

  8. Research on configuration of railway self-equipped tanker based on minimum cost maximum flow model

    Yang, Yuefang; Gan, Chunhui; Shen, Tingting


    In the study of the configuration of the tanker of chemical logistics park, the minimum cost maximum flow model is adopted. Firstly, the transport capacity of the park loading and unloading area and the transportation demand of the dangerous goods are taken as the constraint condition of the model; then the transport arc capacity, the transport arc flow and the transport arc edge weight are determined in the transportation network diagram; finally, the software calculations. The calculation results show that the configuration issue of the tankers can be effectively solved by the minimum cost maximum flow model, which has theoretical and practical application value for tanker management of railway transportation of dangerous goods in the chemical logistics park.




    Full Text Available A statistical and hydrological analysis of the maximum flow in the Terpezița river drainage basin. Starting from the idea that hydrological and hydrometeorological parameters have a statistical existence over time and a spatial distribution that can be represented by an interaction between the mathematical and geographical elements, the present paper aims to analyze the relationship between maximum flows, hourly rains, flow coefficients and concentration times of the Terpezita Basin. This is the second-largest sub-basin (182km2 in the basin of Desnatui, which is located in the SW of Romania and is a first degree tributary of the Danube. The assessment of the concentration time, which involves the sizes of the liquid flow and specific liquid flow, was attained according to the physical and geographical characteristics of the basin. Thus taking into account the homogenous character from this point of view and the existence of statistically established hydrological and pluviometric background, we could outline the behavior of Terpezița River Basin during the extreme hydro-meteorological events. The documentation was completed through an exemplification of previously calculated results, using observations and measurements of the river bed in the vicinity of Terpezita village and processing the values that resulted from the hydro-graph of the 2005 flash-flood.

  10. A route-based decomposition for the Multi-Commodity k-splittable Maximum Flow Problem

    Gamst, Mette


    The Multi-Commodity k-splittable Maximum Flow Problem routes flow through a capacitated graph such that each commodity uses at most k paths and such that the total amount of routedflow is maximized. This paper proposes a branch-and-price algorithm based on a route-based Dantzig-Wolfe decomposition......, where a route consists of up to k paths. Computational results show that the new algorithm has best performance on seven benchmark instances and is capable of solving two previously unsolved instances....

  11. Minimum cost maximum flow algorithm for upstream bandwidth allocation in OFDMA passive optical networks

    Wu, Yating; Kuang, Bin; Wang, Tao; Zhang, Qianwu; Wang, Min


    This paper presents a minimum cost maximum flow (MCMF) based upstream bandwidth allocation algorithm, which supports differentiated QoS for orthogonal frequency division multiple access passive optical networks (OFDMA-PONs). We define a utility function as the metric to characterize the satisfaction degree of an ONU on the obtained bandwidth. The bandwidth allocation problem is then formulated as maximizing the sum of the weighted total utility functions of all ONUs. By constructing a flow network graph, we obtain the optimized bandwidth allocation using the MCMF algorithm. Simulation results show that the proposed scheme improves the performance in terms of mean packet delay, packet loss ratio and throughput.

  12. Structure of Turbulence in Katabatic Flows Below and Above the Wind-Speed Maximum

    Grachev, Andrey A.; Leo, Laura S.; Sabatino, Silvana Di; Fernando, Harindra J. S.; Pardyjak, Eric R.; Fairall, Christopher W.


    Measurements of small-scale turbulence made in the atmospheric boundary layer over complex terrain during the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured on four towers deployed along the east lower slope (2-4°) of Granite Mountain near Salt Lake City in Utah, USA. The multi-level (up to seven) observations made during a 30-day long MATERHORN field campaign in September-October 2012 allowed the study of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence statistics (e.g., fluxes, variances, spectra, and cospectra) and their variations in katabatic flow. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along-slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The momentum flux is directed downward (upward) whereas the along-slope heat flux is downslope (upslope) below (above) the wind maximum. This suggests that the position of the jet-speed maximum can be obtained by linear interpolation between positive and negative values of the momentum flux (or the along-slope heat flux) to derive the height where the flux becomes zero. It is shown that the standard deviations of all wind-speed components (and therefore of the turbulent kinetic energy) and the dissipation rate of turbulent kinetic energy have a local minimum, whereas the standard deviation of air temperature has an absolute maximum at the height of wind-speed maximum. We report several cases when the destructive effect of vertical heat flux is completely cancelled by the generation of turbulence due to the along-slope heat flux. Turbulence above the wind

  13. Declining streamflows reveal nonstationary orographic precipitation enhancement driven by reduced westerly flows

    Luce, Charles; Abatzoglou, John; Holden, Zachary


    Although orographic enhancement of precipitation lends mountains an important role in water resources, they are dramatically undersampled by long-term precipitation gages. This has led to the widespread practice of extrapolating trends in low-elevation precipitation gage networks to high elevations via simple climatological precipitation ratios developed from isohyetal maps. An implicit assumption in such a process is non-stationarity in orographic precipitation enhancement, an assumption that can lead to large errors in trend detection and attribution of climate change effects. We show an example from the Northwestern United States where streamflows from mountain watersheds show substantial declines over the last 60 years, even while long-term precipitation gage networks in the region show no trend. We demonstrate that these observed streamflow declines are driven by previously unexplored differential trends in precipitation. November to March westerly winds are strongly correlated with high-elevation precipitation but weakly correlated with low-elevation precipitation. Decreases in winter westerlies across the region from 1950 to 2012 are hypothesized to have reduced orographic precipitation enhancement, yielding differential trends in precipitation across elevations leading to the apparent paradox. Climate projections show continued weakening meridional pressure gradients and westerly flow across the region under greenhouse forcing, highlighting an additional stressor that is relevant for climate change impacts on water resources. This study also reveals the potential of wind speed data from circulation reanalysis products to better inform historical precipitation reconstructions.

  14. Maximum Likelihood Estimation of Monocular Optical Flow Field for Mobile Robot Ego-motion

    Huajun Liu


    Full Text Available This paper presents an optimized scheme of monocular ego-motion estimation to provide location and pose information for mobile robots with one fixed camera. First, a multi-scale hyper-complex wavelet phase-derived optical flow is applied to estimate micro motion of image blocks. Optical flow computation overcomes the difficulties of unreliable feature selection and feature matching of outdoor scenes; at the same time, the multi-scale strategy overcomes the problem of road surface self-similarity and local occlusions. Secondly, a support probability of flow vector is defined to evaluate the validity of the candidate image motions, and a Maximum Likelihood Estimation (MLE optical flow model is constructed based not only on image motion residuals but also their distribution of inliers and outliers, together with their support probabilities, to evaluate a given transform. This yields an optimized estimation of inlier parts of optical flow. Thirdly, a sampling and consensus strategy is designed to estimate the ego-motion parameters. Our model and algorithms are tested on real datasets collected from an intelligent vehicle. The experimental results demonstrate the estimated ego-motion parameters closely follow the GPS/INS ground truth in complex outdoor road scenarios.

  15. Creep measurements confirm steady flow after stress maximum in extension of branched polymer melts

    Javier Alvarez, Nicolas; Román Marín, José Manuel; Huang, Qian;


    We provide conclusive evidence of nonmonotonic mechanical behavior in the extension of long-chain branched polymer melts. While nonmonotonic behavior is known to occur for solids, for the case of polymeric melts, this phenomenon is in direct contrast with current theoretical models. We rule out...... the possibility of the overshoot being an experimental artifact by confirming the existence of steady flow after a maximum in the ratio of stress to strain rate versus strain under both constant stress and constant strain-rate kinematics. This observation indicates the omission of important physics from current...

  16. An Exact Solution Approach for the Maximum Multicommodity K-splittable Flow Problem

    Gamst, Mette; Petersen, Bjørn


    This talk concerns the NP-hard Maximum Multicommodity k-splittable Flow Problem (MMCkFP) in which each commodity may use at most k paths between its origin and its destination. A new branch-and-cut-and-price algorithm is presented. The master problem is a two-index formulation of the MMCk......FP and the pricing problem is the shortest path problem with forbidden paths. A new branching strategy forcing and forbidding the use of certain paths is developed. The new branch-and-cut-and-price algorithm is computationally evaluated and compared to results from the literature. The new algorithm shows very...

  17. Wavelength selection in injection-driven Hele-Shaw flows: A maximum amplitude criterion

    Dias, Eduardo; Miranda, Jose


    As in most interfacial flow problems, the standard theoretical procedure to establish wavelength selection in the viscous fingering instability is to maximize the linear growth rate. However, there are important discrepancies between previous theoretical predictions and existing experimental data. In this work we perform a linear stability analysis of the radial Hele-Shaw flow system that takes into account the combined action of viscous normal stresses and wetting effects. Most importantly, we introduce an alternative selection criterion for which the selected wavelength is determined by the maximum of the interfacial perturbation amplitude. The effectiveness of such a criterion is substantiated by the significantly improved agreement between theory and experiments. We thank CNPq (Brazilian Sponsor) for financial support.

  18. Particularities of periods with maximum water flow on the rivers from the Suceava hydrographic basin (1981–2005



    Full Text Available Suceava river basin gets its tributaries from the eastern slopes of the northern group of the Eastern Romanian Carpathians, situated under the influence of Baltic air masses, which bring rainfalls and cold weather, felt into the water flow regime of rivers in the region studied. This water flow regime varies from month to month, with the maximum flow having the most important role in the restoration of underground water reserves. This study examines the temporal (frequency, duration and intensity and quantitative (volume and flow parameters of periods with maximum flow, at monthly and seasonal level, revealing the differences in the water flow regime induced by the relief’s morphometric particularities (altitude, fragmentation degree, exhibition. For the evaluation of mentioned parameters was appealed to the TML 2.1 extension from the HydroOffice software package, which uses quantitative thresholds, depending on which it is set the appearance, and disappearance of periods with maximum flow.

  19. Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum

    Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W


    Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...

  20. Thermodynamics, maximum power, and the dynamics of preferential river flow structures on continents

    A. Kleidon


    Full Text Available The organization of drainage basins shows some reproducible phenomena, as exemplified by self-similar fractal river network structures and typical scaling laws, and these have been related to energetic optimization principles, such as minimization of stream power, minimum energy expenditure or maximum "access". Here we describe the organization and dynamics of drainage systems using thermodynamics, focusing on the generation, dissipation and transfer of free energy associated with river flow and sediment transport. We argue that the organization of drainage basins reflects the fundamental tendency of natural systems to deplete driving gradients as fast as possible through the maximization of free energy generation, thereby accelerating the dynamics of the system. This effectively results in the maximization of sediment export to deplete topographic gradients as fast as possible and potentially involves large-scale feedbacks to continental uplift. We illustrate this thermodynamic description with a set of three highly simplified models related to water and sediment flow and describe the mechanisms and feedbacks involved in the evolution and dynamics of the associated structures. We close by discussing how this thermodynamic perspective is consistent with previous approaches and the implications that such a thermodynamic description has for the understanding and prediction of sub-grid scale organization of drainage systems and preferential flow structures in general.

  1. Thermodynamics, maximum power, and the dynamics of preferential river flow structures at the continental scale

    A. Kleidon


    Full Text Available The organization of drainage basins shows some reproducible phenomena, as exemplified by self-similar fractal river network structures and typical scaling laws, and these have been related to energetic optimization principles, such as minimization of stream power, minimum energy expenditure or maximum "access". Here we describe the organization and dynamics of drainage systems using thermodynamics, focusing on the generation, dissipation and transfer of free energy associated with river flow and sediment transport. We argue that the organization of drainage basins reflects the fundamental tendency of natural systems to deplete driving gradients as fast as possible through the maximization of free energy generation, thereby accelerating the dynamics of the system. This effectively results in the maximization of sediment export to deplete topographic gradients as fast as possible and potentially involves large-scale feedbacks to continental uplift. We illustrate this thermodynamic description with a set of three highly simplified models related to water and sediment flow and describe the mechanisms and feedbacks involved in the evolution and dynamics of the associated structures. We close by discussing how this thermodynamic perspective is consistent with previous approaches and the implications that such a thermodynamic description has for the understanding and prediction of sub-grid scale organization of drainage systems and preferential flow structures in general.

  2. Estimation of the Unextendable Dead Time Period in a Flow of Physical Events by the Method of Maximum Likelihood

    Nezhel'skaya, L. A.


    A flow of physical events (photons, electrons, and other elementary particles) is studied. One of the mathematical models of such flows is the modulated MAP flow of events circulating under conditions of unextendable dead time period. It is assumed that the dead time period is an unknown fixed value. The problem of estimation of the dead time period from observations of arrival times of events is solved by the method of maximum likelihood.

  3. FlowMax: A Computational Tool for Maximum Likelihood Deconvolution of CFSE Time Courses.

    Maxim Nikolaievich Shokhirev

    Full Text Available The immune response is a concerted dynamic multi-cellular process. Upon infection, the dynamics of lymphocyte populations are an aggregate of molecular processes that determine the activation, division, and longevity of individual cells. The timing of these single-cell processes is remarkably widely distributed with some cells undergoing their third division while others undergo their first. High cell-to-cell variability and technical noise pose challenges for interpreting popular dye-dilution experiments objectively. It remains an unresolved challenge to avoid under- or over-interpretation of such data when phenotyping gene-targeted mouse models or patient samples. Here we develop and characterize a computational methodology to parameterize a cell population model in the context of noisy dye-dilution data. To enable objective interpretation of model fits, our method estimates fit sensitivity and redundancy by stochastically sampling the solution landscape, calculating parameter sensitivities, and clustering to determine the maximum-likelihood solution ranges. Our methodology accounts for both technical and biological variability by using a cell fluorescence model as an adaptor during population model fitting, resulting in improved fit accuracy without the need for ad hoc objective functions. We have incorporated our methodology into an integrated phenotyping tool, FlowMax, and used it to analyze B cells from two NFκB knockout mice with distinct phenotypes; we not only confirm previously published findings at a fraction of the expended effort and cost, but reveal a novel phenotype of nfkb1/p105/50 in limiting the proliferative capacity of B cells following B-cell receptor stimulation. In addition to complementing experimental work, FlowMax is suitable for high throughput analysis of dye dilution studies within clinical and pharmacological screens with objective and quantitative conclusions.

  4. A Comparison of Electromagnetic Induction Mapping to Measurements of Maximum Effluent Flow Depth for Assessing Flow Paths in Vegetative Treatment Areas

    Vegetative treatment systems (VTSs) are one type of control structure that has shown potential to control runoff from open feedlots. To achieve maximum performance, sheet-flow over the width of the vegetative treatment area (VTA) is required. Tools, such as maps of flow paths through the VTA, are ne...

  5. Uncertainties in transient projections of maximum and minimum flows over the United States

    Giuntoli, Ignazio; Villarini, Gabriele; Prudhomme, Christel; Hannah, David M.


    Global multi-model ensemble experiments provide a valuable basis for the examination of potential future changes in runoff. However, these projections suffer from uncertainties that originate from different sources at different levels in the modelling chain. We present the partitioning of uncertainty into four distinct sources of projections of decadally-averaged annual maximum (AMax) and minimum (AMin) flows over the USA. More specifically, we quantify the relative contribution of the uncertainties arising from internal variability, global impact models (GIMs), global climate models (GCMs), and representative concentration pathways (RCPs). We use a set of nine state-of-the-art GIMs driven by five CMIP5 GCMs under four RCPs from the ISI-MIP multi-model ensemble. We examine the temporal changes in the relative contribution of each source of uncertainty over the course of the 21st century. Results show that GCMs and GIMs are responsible for the majority of uncertainty over most of the study area, followed by internal variability and RCPs. Proportions vary regionally and depend on the end of the runoff spectrum (AMax, AMin) considered. In particular, for AMax, large fractions of uncertainty are attributable to GCMs throughout the century with the GIMs increasing their share especially in mountainous and cold areas. For Amin, the contribution of GIMs to uncertainty increases with time, becoming the dominant source over most of the country by the end of the 21st century. Importantly, compared to the other sources, the RCPs contribution to uncertainty is negligible generally (for AMin especially). This finding indicates that the effects of different emission scenarios are barely noticeable in hydrological impact studies, while GIMs and GCMs make up most of the amplitude of the ensemble spread (uncertainty).

  6. A local search heuristic for the Multi-Commodity k-splittable Maximum Flow Problem

    Gamst, Mette


    The Multi-Commodity k-splittable Maximum Flow Problem consists of maximizing the amount of flow routed through a network such that each commodity uses at most k paths and such that edge capacities are satisfied. The problem is NP -hard and has application in a.o. telecommunications. In this paper......, a local search heuristic for solving the problem is proposed. The heuristic is an iterative shortest path procedure on a reduced graph combined with a local search procedure to modify certain path flows and prioritize the different commodities. The heuristic is tested on benchmark instances from...

  7. Sub-Clinical Cognitive Decline and Resting Cerebral Blood Flow in Middle Aged Men

    Henriksen, Otto Mølby; Hansen, Naja Liv; Osler, Merete


    of early sub-clinical cognitive decline with CBF. MATERIALS AND METHODS: The study participants were recruited from a cohort of Danish men born in 1953. Based on a regression model we selected men who performed better (Group A, n = 94) and poorer (Group B, n = 95) on cognitive testing at age 57 than...... expected from testing at age 20. Participants underwent supplementary cognitive testing, blood sampling and MRI including measurements of regional and global CBF. RESULTS: Regional CBF was lower in group B than in group A in the posterior cingulate gyrus and the precuneus. The associations were attenuated...

  8. Estimation of the maximum contraction velocity of the urinary bladder from pressure and flow throughout micturition.

    R. van Mastrigt (Ron)


    textabstractThe contractility of the urinary bladder can be adequately described in terms of the parameters P0 (isometric pressure) and Vmax (maximum contraction velocity). In about 12% of urodynamic evaluations of patients these clinically relevant parameters can be calculated from pressure and flo


    Lau Nguyen Dinh


    Full Text Available The problem of finding maximum flow in network graph is extremely interesting and practically applicable in many fields in our daily life, especially in transportation. Therefore, a lot of researchers have been studying this problem in various methods. Especially in 2013, we has developed a new algorithm namely, postflow-pull algorithm to find the maximum flow on traditional networks. In this paper, we revised postflow-push methods to solve this problem of finding maximum flow on extended mixed network. In addition, to take more advantage of multi-core architecture of the parallel computing system, we build this parallel algorithm. This is a completely new method not being announced in the world. The results of this paper are basically systematized and proven. The idea of this algorithm is using multi processors to work in parallel by postflow_push algorithm. Among these processors, there is one main processor managing data, sending data to the sub processors, receiving data from the sub-processors. The sub-processors simultaneously execute their work and send their data to the main processor until the job is finished, the main processor will show the results of the problem.

  10. Towards realizable hyperbolic moment closures for viscous heat-conducting gas flows based on a maximum-entropy distribution

    McDonald, James G.; Groth, Clinton P. T.


    The ability to predict continuum and transition-regime flows by hyperbolic moment methods offers the promise of several advantages over traditional techniques. These methods offer an extended range of physical validity as compared with the Navier-Stokes equations and can be used for the prediction of many non-equilibrium flows with a lower expense than particle-based methods. Also, the hyperbolic first-order nature of the resulting partial differential equations leads to mathematical and numerical advantages. Moment equations generated through an entropy-maximization principle are particularly attractive due to their apparent robustness; however, their application to practical situations involving viscous, heat-conducting gases has been hampered by several issues. Firstly, the lack of closed-form expressions for closing fluxes leads to numerical expense as many integrals of distribution functions must be computed numerically during the course of a flow computation. Secondly, it has been shown that there exist physically realizable moment states for which the entropy-maximizing problem on which the method is based cannot be solved. Following a review of the theory surrounding maximum-entropy moment closures, this paper shows that both of these problems can be addressed in practice, at least for a simplified one-dimensional gas, and that the resulting flow predictions can be surprisingly good. The numerical results described provide significant motivations for the extension of these ideas to the fully three-dimensional case.

  11. Comparative Study of Peak Expiratory Flow Rate and Maximum Voluntary Ventilation Between Smokers and Non-Smokers

    Karia Ritesh M


    Full Text Available Objective: Objectives of this study is to study effect of smoking on Peak Expiratory Flow Rate and Maximum Voluntary Ventilation in apparently healthy tobacco smokers and non-smokers and to compare the result of both the studies to assess the effects of smoking Method: The present study was carried out by computerized software of Pulmonary Function Test named ‘Spiro Excel’ on 50 non-smokers and 50 smokers. Smokers are divided in three gropus. Full series of test take 4 to 5 minutes. Tests were compared in the both smokers and non-smokers group by the ‘unpaired t test’. Statistical significance was indicated by ‘p’ value < 0.05. Results: From the result it is found that actual value of Peak Expiratory Flow Rate and Maximum Voluntary Ventilation are significantly lower in all smokers group than non-smokers. The difference of actual mean value is increases as the degree of smoking increases. [National J of Med Res 2012; 2(2.000: 191-193

  12. Natural Examples of Olivine Lattice Preferred Orientation Patterns With a Flow-Normal a-Axis Maximum

    Mizukami, T.; Wallis, S.; Yamamoto, J.


    Olivine lattice preferred orientation (LPO) due to ductile deformation is one of the main causes of mechanical anisotropy in the upper mantle and the patterns are useful to infer the direction of mantle flow from the seismic anisotropy in various settings. In subduction zones the mantle anisotropy near subduction boundaries suggests that olivine a-axes are arranged roughly perpendicular to plate motion. This anisotropy has been attributed to localized subduction-normal flow, applying a common type of olivine LPO with a `flow-parallel' a-axis maximum to the mantle. However, a recent deformational experiment provides an alternative interpretation that the B-type LPO with a `flow-normal' a-axis maximum can be developed in water-rich mantle above subducting slab. We document the widespread occurrence of B-type LPO in the Higashi-akaishi peridotite body, SW Japan, and examine the physical conditions in which it was formed. Our structural studies define four deformational phases in the Higashi-akaishi body (D1-D4) that are related to the tectonic evolution in the Cretaceous subduction zone at the Eurasian margin. The main deformational stage, D2, is associated with dynamic recrystallization of olivine to form porphyroclastic microstructure consisting of clear olivine neoblasts and porphyroclasts with abundant micro-inclusions. Parallel alginment of olivine neoblasts defines a stretching lineation (L2) and tectonic foliation (S2) and the D2 olivine LPO is identified as the B-type fabric with a-axes normal to L2, b-axes normal to S2 and c-axes parallel to L2. Micro-Raman spectroscopic analyses reveal that the syn-D2 micro-inclusions include hydrous minerals such as serpentine, indicating water-rich conditions for the D2 deformation. Garnet-orthopyroxene geothermobarometry applied to the D2 garnet peridotite reveals that the D2 stage was associated with the almost isothermal burial (700-800C, 2-3GPa). These D2 physical conditions in which the B-type LPO was formed are

  13. Decline of the performance of a portable axial-flow fan due to the friction and duct bending loss of a connected flexible duct.

    Ojima, Jun


    In a job site, a portable fan is often used to ventilate a confined space. When a portable fan is applied to such a space, the actual ventilation flow rate must be accurately estimated in advance because the safety level of contaminant and oxygen concentrations in the space will determine the ventilation requirements. When a portable fan is used with a flexible duct, the actual flow rate of the fan decreases due to the friction and duct bending loss of the duct. Intending to show the decline of a fan performance, the author conducted laboratory experiments and reported the quantitative effect of the friction and duct bending loss of a flexible duct to the flow rate of a portable fan. Four commercial portable fans of different specifications were procured for the experiments, and the decline of the performance of each portable fan due to the friction loss etc. of a connected flexible duct was investigated by measuring actual flow rate. The flow rate showed an obvious decrease from the rated flow rate when a flexible duct was connected. Connection of a straight polyester flexible duct and a straight aluminum flexible duct reduced the flow rates to 81.2 - 52.9% and less than 50%, respectively. The flow rate decreased with an increase of the bend angle of the flexible duct. It is recommended that flow rate check of a portable fan should be diligently carried out in every job site.

  14. Critical flow-storm approach to total maximum daily load(TMDL) development: an analytical conceptual model

    Harry X.ZHANG; Shaw L.YU


    One of the key challenges in the total max-imum daily load (TMDL) development process is how to define the critical condition for a receiving water-body. The main concern in using a continuous simu-lation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scar-city of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continu-ous and evEnt-based approaches in defining critical con-dition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the crit-ical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having cer-tain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.

  15. Research on network maximum flows algorithm of cascade level graph%级连层次图的网络最大流算法研究

    潘荷新; 伊崇信; 李满


    给出一种通过构造网络级连层次图的方法,来间接求出最大网络流的算法.对于给定的有n个顶点,P条边的网络N=(G,s,t,C),该算法可在O(n2)时间内快速求出流经网络N的最大网络流及达最大流时的网络流.%This paper gives an algoritm that structures a network cascade level graph to find out maximum flow of the network indirectly.For the given network N=(G,s,t,C) that has n vetexes and e arcs,this algorithm finds out the maximum value of the network flow fast in O(n2) time that flows from the network N and the network flows when the value of the one reach maximum.

  16. Measuring maximum and standard metabolic rates using intermittent-flow respirometry: a student laboratory investigation of aerobic metabolic scope and environmental hypoxia in aquatic breathers.

    Rosewarne, P J; Wilson, J M; Svendsen, J C


    Metabolic rate is one of the most widely measured physiological traits in animals and may be influenced by both endogenous (e.g. body mass) and exogenous factors (e.g. oxygen availability and temperature). Standard metabolic rate (SMR) and maximum metabolic rate (MMR) are two fundamental physiological variables providing the floor and ceiling in aerobic energy metabolism. The total amount of energy available between these two variables constitutes the aerobic metabolic scope (AMS). A laboratory exercise aimed at an undergraduate level physiology class, which details the appropriate data acquisition methods and calculations to measure oxygen consumption rates in rainbow trout Oncorhynchus mykiss, is presented here. Specifically, the teaching exercise employs intermittent flow respirometry to measure SMR and MMR, derives AMS from the measurements and demonstrates how AMS is affected by environmental oxygen. Students' results typically reveal a decline in AMS in response to environmental hypoxia. The same techniques can be applied to investigate the influence of other key factors on metabolic rate (e.g. temperature and body mass). Discussion of the results develops students' understanding of the mechanisms underlying these fundamental physiological traits and the influence of exogenous factors. More generally, the teaching exercise outlines essential laboratory concepts in addition to metabolic rate calculations, data acquisition and unit conversions that enhance competency in quantitative analysis and reasoning. Finally, the described procedures are generally applicable to other fish species or aquatic breathers such as crustaceans (e.g. crayfish) and provide an alternative to using higher (or more derived) animals to investigate questions related to metabolic physiology.

  17. Declination Calculator

    National Oceanic and Atmospheric Administration, Department of Commerce — Declination is calculated using the current International Geomagnetic Reference Field (IGRF) model. Declination is calculated using the current World Magnetic Model...

  18. [Estimation of topographical factors in revised universal soil loss model based on maximum up-stream flow path].

    Luo, Hong; Ma, You-xin; Liu, Wen-jun; Li, Hong-mei


    By using maximum upstream flow path, a self-developed new method for calculating slope length value based on Arc Macro Language (AML), five groups of DEM data for different regions in Bijie Prefecture of Guizhou Province were extracted to compute the slope length and topographical factors in the Prefecture. The time cost for calculating the slope length and the values of the topographical factors were analyzed, and compared with those by iterative slope length method based on AML (ISLA) and on C++ (ISLC). The results showed that the new method was feasible to calculate the slope length and topographical factors in revised universal soil loss model, and had the same effect as iterative slope length method. Comparing with ISLA, the new method had a high computing efficiency and greatly decreased the time consumption, and could be applied to a large area to estimate the slope length and topographical factors based on AML. Comparing with ISLC, the new method had the similar computing efficiency, but its coding was easily to be written, modified, and debugged by using AML. Therefore, the new method could be more broadly used by GIS users.

  19. Relationship between visual prostate score (VPSS and maximum flow rate (Qmax in men with urinary tract symptoms

    Mazhar A. Memon


    Full Text Available ABSTRACT Objective: To evaluate correlation between visual prostate score (VPSS and maximum flow rate (Qmax in men with lower urinary tract symptoms. Material and Methods: This is a cross sectional study conducted at a university Hospital. Sixty-seven adult male patients>50 years of age were enrolled in the study after signing an informed consent. Qmax and voided volume recorded at uroflowmetry graph and at the same time VPSS were assessed. The education level was assessed in various defined groups. Pearson correlation coefficient was computed for VPSS and Qmax. Results: Mean age was 66.1±10.1 years (median 68. The mean voided volume on uroflowmetry was 268±160mL (median 208 and the mean Qmax was 9.6±4.96mLs/sec (median 9.0. The mean VPSS score was 11.4±2.72 (11.0. In the univariate linear regression analysis there was strong negative (Pearson's correlation between VPSS and Qmax (r=848, p<0.001. In the multiple linear regression analyses there was a significant correlation between VPSS and Qmax (β- after adjusting the effect of age, voided volume (V.V and level of education. Multiple linear regression analysis done for independent variables and results showed that there was no significant correlation between the VPSS and independent factors including age (p=0.27, LOE (p=0.941 and V.V (p=0.082. Conclusion: There is a significant negative correlation between VPSS and Qmax. The VPSS can be used in lieu of IPSS score. Men even with limited educational background can complete VPSS without assistance.

  20. Pre-test estimates of temperature decline for the LANL Fenton Hill Long-Term Flow Test

    Robinson, B.A. [Los Alamos National Lab., NM (United States); Kruger, P. [Stanford Univ., CA (United States). Stanford Geothermal Program


    Pre-test predications for the Long-Term Flow Test (LTFT) of the experimental Hot Dry Rock (HDR) reservoir at Fenton Hill were made using two models. Both models are dependent on estimates of the ``effective`` reservoir volume accessed by the fluid and the mean fracture spacing (MFS) of major joints for fluid flow. The effective reservoir volume was estimated using a variety of techniques, and the range of values for the MFS was set through experience in modeling the thermal cooldown of other experimental HDR reservoirs. The two pre-test predictions for cooldown to 210{degrees}C (a value taken to compare the models) from initial temperature of 240{degrees}C are 6.1 and 10.7 years. Assuming that a minimum of 10{degrees}C is required to provide an unequivocal indication of thermal cooldown, both models predict that the reservoir will not exhibit observable cooldown for at least two years.

  1. A decomposition based on path sets for the Multi-Commodity k-splittable Maximum Flow Problem

    Gamst, Mette

    Switching. In the literature, the problem is solved to optimality using branch-and-price algorithms built on path-based Dantzig-Wolfe decompositions. This paper proposes a new branch-and-price algorithm built on a path set-based Dantzig-Wolfe decomposition. A path set consists of up to k paths, each...... carrying a certain amount of flow. The new branch-and-price algorithm is implemented and compared to the leading algorithms in the literature. Results for the proposed method are competitive and the method even has best performance on some instances. However, the results also indicate some scaling issues....

  2. Inference of Gene Flow in the Process of Speciation: An Efficient Maximum-Likelihood Method for the Isolation-with-Initial-Migration Model

    Costa, Rui J.; Wilkinson-Herbots, Hilde


    The isolation-with-migration (IM) model is commonly used to make inferences about gene flow during speciation, using polymorphism data. However, it has been reported that the parameter estimates obtained by fitting the IM model are very sensitive to the model’s assumptions—including the assumption of constant gene flow until the present. This article is concerned with the isolation-with-initial-migration (IIM) model, which drops precisely this assumption. In the IIM model, one ancestral population divides into two descendant subpopulations, between which there is an initial period of gene flow and a subsequent period of isolation. We derive a very fast method of fitting an extended version of the IIM model, which also allows for asymmetric gene flow and unequal population sizes. This is a maximum-likelihood method, applicable to data on the number of segregating sites between pairs of DNA sequences from a large number of independent loci. In addition to obtaining parameter estimates, our method can also be used, by means of likelihood-ratio tests, to distinguish between alternative models representing the following divergence scenarios: (a) divergence with potentially asymmetric gene flow until the present, (b) divergence with potentially asymmetric gene flow until some point in the past and in isolation since then, and (c) divergence in complete isolation. We illustrate the procedure on pairs of Drosophila sequences from ∼30,000 loci. The computing time needed to fit the most complex version of the model to this data set is only a couple of minutes. The R code to fit the IIM model can be found in the supplementary files of this article. PMID:28193727

  3. Exploiting Maximum Entropy method and ASTER data for assessing debris flow and debris slide susceptibility for the Giampilieri catchment (north-eastern Sicily, Italy).

    Lombardo, L.


    This study aims at evaluating the performance of the Maximum Entropy method in assessing landslide susceptibility, exploiting topographic and multispectral remote sensing predictors. We selected the catchment of the Giampilieri stream, which is located in the north-eastern sector of Sicily (southern Italy), as test site. On 1/10/2009, a storm rainfall triggered in this area hundreds of debris flow/avalanche phenomena causing extensive economical damage and loss of life. Within this area a presence-only-based statistical method was applied to obtain susceptibility models capable of distinguish future activation sites of debris flow and debris slide, which where the main source failure mechanisms for flow or avalanche type propagation. The set of predictors used in this experiment comprised primary and secondary topographic attributes, derived by processing a high resolution digital elevation model, CORINE land cover data and a set of vegetation and mineral indices obtained by processing multispectral ASTER images. All the selected data sources are dated before the disaster. A spatially random partition technique was adopted for validation, generating fifty replicates for each of the two considered movement typologies in order to assess accuracy, precision and reliability of the models. The debris slide and debris flow susceptibility models produced high performances with the first type being the best fitted. The evaluation of the probability estimates around the mean value for each mapped pixel shows an inverted relation, with the most robust models corresponding to the debris flows. With respect to the role of each predictor within the modelling phase, debris flows appeared to be primarily controlled by topographic attributes whilst the debris slides were better explained by remotely sensed derived indices, particularly by the occurrence of previous wildfires across the slope. The overall excellent performances of the two models suggest promising perspectives for




    Full Text Available The purpose of the paper is to identify and locate some species related to habitats from Pricop-Huta-Certeze and Upper Tisa Natura 2000 Protected Areas (PHCTS and to determine if they are vulnerable to risks induced by maximum flow phases. In the first chapter are mentioned few references about the morphometric parameters of the hydrographic networks within the study area, as well as some references related to the maximum flow phases frequency. After the second chapter, where methods and databases used in the study are described, we proceed to the identification of the areas that are covered by water during flood, as well as determining the risk level related to these areas. The GIS modeling reveals small extent of the flood high risk for natural environment related to protected areas and greater extent for the anthropic environment. The last chapter refers to several species of fish and batrachia, as well as to those amphibious mammals identified in the study area that are vulnerable to floods (high turbidity effect, reduction of dissolved oxygen quantity, habitats destruction etc..

  5. Contributions of the secondary jet to the maximum tangential velocity and to the collection efficiency of the fixed guide vane type axial flow cyclone dust collector

    Ogawa, Akira; Anzou, Hideki; Yamamoto, So; Shimagaki, Mituru


    In order to control the maximum tangential velocity Vθm(m/s) of the turbulent rotational air flow and the collection efficiency ηc (%) using the fly ash of the mean diameter XR50=5.57 µm, two secondary jet nozzles were installed to the body of the axial flow cyclone dust collector with the body diameter D1=99mm. Then in order to estimate Vθm (m/s), the conservation theory of the angular momentum flux with Ogawa combined vortex model was applied. The comparisons of the estimated results of Vθm(m/s) with the measured results by the cylindrical Pitot-tube were shown in good agreement. And also the estimated collection efficiencies ηcth (%) basing upon the cut-size Xc (µm) which was calculated by using the estimated Vθ m(m/s) and also the particle size distribution R(Xp) were shown a little higher values than the experimental results due to the re-entrainment of the collected dust. The best method for adjustment of ηc (%) related to the contribution of the secondary jet flow is principally to apply the centrifugal effect Φc (1). Above stated results are described in detail.

  6. Maximum Fidelity

    Kinkhabwala, Ali


    The most fundamental problem in statistics is the inference of an unknown probability distribution from a finite number of samples. For a specific observed data set, answers to the following questions would be desirable: (1) Estimation: Which candidate distribution provides the best fit to the observed data?, (2) Goodness-of-fit: How concordant is this distribution with the observed data?, and (3) Uncertainty: How concordant are other candidate distributions with the observed data? A simple unified approach for univariate data that addresses these traditionally distinct statistical notions is presented called "maximum fidelity". Maximum fidelity is a strict frequentist approach that is fundamentally based on model concordance with the observed data. The fidelity statistic is a general information measure based on the coordinate-independent cumulative distribution and critical yet previously neglected symmetry considerations. An approximation for the null distribution of the fidelity allows its direct conversi...

  7. Well production decline

    Cvetkovic, Branimir


    complementary to the reservoir simulation. More geology features should be considered to fully take advantage of the modelling findings. The starting point of the second modelling step concerns late time vertical-well responses or decline curves involving empirical solution of Arps type. This includes an investigation of well pressure responses for a rate decline of an Arps-type variable-rate of a wellbore for selected exponents, b. The modelling explores pressure wellbore responses during a variable-rate production, and the approach introduces a no-flow specified boundary that moves outwards from a wellbore axis with a predefined speed. For the specific speed of a no-flow moving boundary, the model generates pressure profiles causing the decline exponents, b. Known b values were selected and each of them was empirically derived through the inflow performance relationships to a drive mechanism. This modelling approach with analytically derived pressure solutions can be extended to a horizontal well. Furthermore, the continuously measured well rates and pressure models can be calibrated and verified. (Author)

  8. Analysis of inflow in geothermal wells to determine their maximum flow; Analisis del influjo en pozos geotermicos para la determinacion de sus flujos maximos

    Aragon-Aguilar, Alfonso; Izquierdo-Montalvo, Georgina; Pal-Verma, Mahendra; Santoyo-Gutierrez, Socrates [Instituto de Investigaciones Electricas (Mexico); Moya-Acosta, Sara L [Centro Nacional de Investigacion y Desarrollo Tecnologico (Mexico)


    Inflow performance relationships developed for petroleum and geothermal reservoirs are presented. Four of them were selected to be used in this work. Such relationships were developed considering features of a typical geothermal system. The performance of the selected relationships was assessed using data from production tests in several wells of different fields. A methodology is presented to determine the value of the maximum flow (W{sub max}) from the inflow relationships; its application is demonstrated using the data of the 10 production tests. It was found that the calculated value of W{sub max} under stabilization conditions may be related to the reservoir response. In general, there is a good agreement between the calculated values of W{sub max} from the different methods. The differences in the W{sub max} values vary within 10%. It was found that the stability in the calculated values of W{sub max} as a response of the reservoir is a function of the flow magnitude. So, the wells with flow greater than 200 t/h reach the stability of W{sub max} at openings 50% less of their total capacity. [Spanish] Se presentan las relaciones del comportamiento de influjo desarrolladas para yacimientos petroleros y geotermicos. Se seleccionaron cuatro de ellas para usar en este trabajo. Tales relaciones fueron desarrolladas considerando condiciones de un sistema geotermico tipico. Se analizo el comportamiento de las relaciones escogidas utilizando datos de pruebas de produccion de varios pozos de diferentes campos. Se presenta una metodologia para determinar el valor del flujo maximo (W{sub max}) a partir de las relaciones de influjo; se demuestra su aplicabilidad usando los datos de diez pruebas de produccion. Se encontro que el valor de W{sub max} calculado bajo condiciones de estabilizacion se puede relacionar con la respuesta del yacimiento. En general se encuentra buena concordancia entre los valores calculados de W{sub max} usando los diferentes metodos. Las

  9. Algorithm Preserving Mass Fraction Maximum Principle for Multi-component Flows%多组份流动质量分数保极值原理算法

    唐维军; 蒋浪; 程军波


    We propose a new method for compressible multi⁃component flows with Mie⁃Gruneisen equation of state based on mass fraction. The model preserves conservation law of mass, momentum and total energy for mixture flows. It also preserves conservation of mass of all single components. Moreover, it prevents pressure and velocity from jumping across interface that separate regions of different fluid components. Wave propagation method is used to discretize this quasi⁃conservation system. Modification of numerical method is adopted for conservative equation of mass fraction. This preserves the maximum principle of mass fraction. The wave propagation method which is not modified for conservation equations of flow components mass, cannot preserve the mass fraction in the interval [0,1]. Numerical results confirm validity of the method.%对基于质量分数的Mie⁃Gruneisen状态方程多流体组份模型提出了新的数值方法。该模型保持混合流体的质量、动量、和能量守恒,保持各组份分质量守恒,在多流体组份界面处保持压力和速度一致。该模型是拟守恒型方程系统。对该模型系统的离散采用波传播算法。与直接对模型中所有守恒方程采用相同算法不同的是,在处理分介质质量守恒方程时,对波传播算法进行了修正,使之满足质量分数保极值原理。而不作修改的算法则不能保证质量分数在[0,1]范围。数值实验验证了该方法有效。

  10. A Study of the Conditions of Maximum Filtration Efficiency for a HGMF-Axial Magnetic Filter Cell With Bounded Flow Field

    Badescu, V.; Murariu, V.; Rotariu, O; Rezlescu, N.


    The theory of magnetic particles′ capture on a HGMF-axial magnetic filter cell with bounded flow field is presented. The equations of particle motion for both potential and laminar flow are obtained. By analytical solving of these equations, the trajectories of particles are established. The flow velocity of the fluid suspension for the case of potential flow is set equal with the velocity averaged across the tube section for the laminar flow. Thus, it is possible to make a comparison between...

  11. Computer quantification of “angle of collapse” on maximum expiratory flow volume curve for diagnosing asthma-COPD overlap syndrome

    Wang W


    Full Text Available Wei Wang, Mengshuang Xie, Shuang Dou, Liwei Cui, Wei Xiao Department of Pulmonary Medicine, Qilu Hospital, Shandong University, Jinan, People’s Republic of China Background: In a previous study, we demonstrated that asthma patients with signs of emphysema on quantitative computed tomography (CT fulfill the diagnosis of asthma-COPD overlap syndrome (ACOS. However, quantitative CT measurements of emphysema are not routinely available for patients with chronic airway disease, which limits their application. Spirometry was a widely used examination tool in clinical settings and shows emphysema as a sharp angle in the maximum expiratory flow volume (MEFV curve, called the “angle of collapse (AC”. The aim of this study was to investigate the value of the AC in the diagnosis of emphysema and ACOS. Methods: This study included 716 participants: 151 asthma patients, 173 COPD patients, and 392 normal control subjects. All the participants underwent pulmonary function tests. COPD and asthma patients also underwent quantitative CT measurements of emphysema. The AC was measured using computer models based on Matlab software. The value of the AC in the diagnosis of emphysema and ACOS was evaluated using receiver-operating characteristic (ROC curve analysis. Results: The AC of COPD patients was significantly lower than that of asthma patients and control subjects. The AC was significantly negatively correlated with emphysema index (EI; r=-0.666, P<0.001, and patients with high EI had a lower AC than those with low EI. The ROC curve analysis showed that the AC had higher diagnostic efficiency for high EI (area under the curve =0.876 than did other spirometry parameters. In asthma patients, using the AC ≤137° as a surrogate criterion for the diagnosis of ACOS, the sensitivity and specificity were 62.5% and 89.1%, respectively. Conclusion: The AC on the MEFV curve quantified by computer models correlates with the extent of emphysema. The AC may become a

  12. Effects of flow regimes altered by dams on survival, population declines, and range-wide losses of California river-breeding frogs.

    Kupferberg, Sarah J; Palen, Wendy J; Lind, Amy J; Bobzien, Steve; Catenazzi, Alessandro; Drennan, Joe; Power, Mary E


    Widespread alteration of natural hydrologic patterns by large dams combined with peak demands for power and water delivery during summer months have resulted in frequent aseasonal flow pulses in rivers of western North America. Native species in these ecosystems have evolved with predictable annual flood-drought cycles; thus, their likelihood of persistence may decrease in response to disruption of the seasonal synchrony between stable low-flow conditions and reproduction. We evaluated whether altered flow regimes affected 2 native frogs in California and Oregon (U.S.A.) at 4 spatial and temporal extents. We examined changes in species distribution over approximately 50 years, current population density in 11 regulated and 16 unregulated rivers, temporal trends in abundance among populations occupying rivers with different hydrologic histories, and within-year patterns of survival relative to seasonal hydrology. The foothill yellow-legged frog (Rana boylii), which breeds only in flowing water, is more likely to be absent downstream of large dams than in free-flowing rivers, and breeding populations are on average 5 times smaller in regulated rivers than in unregulated rivers. Time series data (range = 8 - 19 years) from 5 populations of yellow-legged frogs and 2 populations of California red-legged frogs (R. draytonii) across a gradient of natural to highly artificial timing and magnitude of flooding indicate that variability of flows in spring and summer is strongly correlated with high mortality of early life stages and subsequent decreases in densities of adult females. Flow management that better mimics natural flow timing is likely to promote persistence of these species and others with similar phenology.

  13. Should measurement of maximum urinary flow rate and residual urine volume be a part of a "minimal care" assessment programme in female incontinence?

    Sander, Pia; Mouritsen, L; Andersen, J Thorup


    OBJECTIVE: The aim of this study was to evaluate the value of routine measurements of urinary flow rate and residual urine volume as a part of a "minimal care" assessment programme for women with urinary incontinence in detecting clinical significant bladder emptying problems. MATERIAL AND METHOD...... female urinary incontinence. Thus, primary health care providers can assess women based on simple guidelines without expensive equipment for assessment of urine flow rate and residual urine....

  14. Maximum-throughput scheduling with limited resources for iterative data-flow graphs by means of the scheduling-range chart

    Heemstra de Groot, S.M.; Herrmann, O.E.


    An algorithm based on an alternative scheduling approach for iterative acyclic and cyclid DFGs (data-flow graphs) with limited resources that exploits inter- and intra-iteration parallelism is presented. The method is based on guiding the scheduling algorithm with the information supplied by a


    高嵩; 尤云祥; 李巍; 胡天群; 俞忠


    针对海洋油气传输中常见的下倾管-立管系统,采用Brackbill模型模拟气液相界面间表面张力,VOF 方法追踪气液两相运动界面,提出了管内气液两相流数值模拟方法.在低气液相进口折算速度下,数值模拟了该种管型下的严莺段塞流动现象,分析了相关物理参数的变化特性.结果表明,在严重段塞流下,管内流型流态、压力、液塞运动速度、立管出口气液相平均速度、下倾管及立管内含气率等均具有明显周期性特征,而且一个周期内严重段塞流可分为4个阶段,进而给出了各阶段中相关参数的变化特性.数值模拟结果与相关文献中的实验结果吻合良好,表明了该数值模拟方法的有效性.%In the present paper, a numerical method for simulating the characteristics of two-phase flows in a declination pipe-riser system with the gas and fluid was developed.The Brackbill model was applied to simulate surface tension between two phases and the VOF method was used to capture the moving interfaces between gas-liquid phases.At low superfical velocity of gas and liquid superficial velocities, severe slug flows in such a pipe-riser system were simulated and the variety characteristics for flow parameters were analyzed.The results show that the flow parameter characteristics due to such a severe slug flow have remarkably periodic characteristics, including the flow pattern, pressure, slug velocity, average phase velocity at the riser outlet and gas volume fraction, and severe slug flow in a period consists of four evolvement stages where the characteristics of such flow parameters in each evolvement stage were further given.The numerical results are good agreements with experimental results reported in the references, showing that the proposed method is effective.

  16. What Makes Clusters Decline?

    Østergaard, Christian Richter; Park, Eun Kyung


    Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark....... The longitudinal study on the high-tech cluster reveals that technological lock-in and exit of key firms have contributed to decline. Entrepreneurship has a positive effect on the cluster’s adaptive capabilities, while multinational companies have contradicting effects by bringing in new resources to the cluster...

  17. US Historic Declination Calculator

    National Oceanic and Atmospheric Administration, Department of Commerce — This programs derives a table of secular change in magnetic declination for a specified point in the conterminous United States. It utilizes the USD polynomial and...


    Sutawanir Darwis


    Full Text Available Empirical decline curve analysis of oil production data gives reasonable answer in hyperbolic type curves situations; however the methodology has limitations in fitting real historical production data in present of unusual observations due to the effect of the treatment to the well in order to increase production capacity. The development ofrobust least squares offers new possibilities in better fitting production data using declinecurve analysis by down weighting the unusual observations. This paper proposes a robustleast squares fitting lmRobMM approach to estimate the decline rate of daily production data and compares the results with reservoir simulation results. For case study, we usethe oil production data at TBA Field West Java. The results demonstrated that theapproach is suitable for decline curve fitting and offers a new insight in decline curve analysis in the present of unusual observations.

  19. Maximum Autocorrelation Factorial Kriging

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.


    This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from...

  20. Cluster Decline and Resilience

    Østergaard, Christian Richter; Park, Eun Kyung

    -2011. Our longitudinal study reveals that technological lock-in and exit of key firms have contributed to impairment of the cluster’s resilience in adapting to disruptions. Entrepreneurship has a positive effect on cluster resilience, while multinational companies have contradicting effects by bringing......Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark, 1963...

  1. Maximum Autocorrelation Factorial Kriging

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.; Steenfelt, Agnete


    This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from an ordinary non-spatial factor analysis, and they are interpreted in a geological context. It is demonstrated that MAF analysis contrary to ordinary non-spatial factor analysis gives an objective discrimina...

  2. Fertility decline in Paraguay.

    Ishida, Kanako; Stupp, Paul; Melian, Mercedes


    Recent reproductive health surveys show that the fertility rate in Paraguay decreased precipitously from 4.3 lifetime births per woman in 1995-98 to 2.9 births in 2001-04. In this study, we establish data consistency between the 1998 and 2004 surveys by comparing a series of cohort-specific period rates and use the Bongaarts framework of proximate determinants of fertility to demonstrate that an increase in the contraceptive prevalence rate (CPR) between 1998 and 2004 fully accounts for the fertility decline. Decomposition of rates shows that changes in group-specific CPRs explain a greater proportion of the change in the overall CPR than do changes in population composition by educational attainment, urban residence, region, and language spoken at home. Finally, we show that younger cohorts of women in 2004 reported ideal completed fertility desires of less than 2.9 births, suggesting that the fertility rate is likely to continue to decrease.

  3. Mangrove forest decline

    Malik, Abdul; Mertz, Ole; Fensholt, Rasmus


    Mangrove forests in the tropics and subtropics grow in saline sediments in coastal and estuarine environments. Preservation of mangrove forests is important for many reasons, including the prevention of coastal erosion and seawater intrusion; the provision of spawning, nursery, and feeding grounds...... and severe mangrove loss with serious consequences. The mangrove forests of the Takalar District, South Sulawesi, are studied here as a case area that has suffered from degradation and declining spatial extent during recent decades. On the basis of a post-classification comparison of change detection from...... satellite imagery and a survey of households, we provide an estimate of the mangrove change in the Takalar District during 1979–2011 and the consequences of those changes. Mangrove forest areas were reduced by 66.05 % (3344 hectares) during the 33-year period of analysis, and the biggest annual negative...

  4. Mobility decline in old age

    Rantakokko, Merja; Mänty, Minna Regina; Rantanen, Taina


    Mobility is important for community independence. With increasing age, underlying pathologies, genetic vulnerabilities, physiological and sensory impairments, and environmental barriers increase the risk for mobility decline. Understanding how mobility declines is paramount to finding ways to pro...... to promote mobility in old age.......Mobility is important for community independence. With increasing age, underlying pathologies, genetic vulnerabilities, physiological and sensory impairments, and environmental barriers increase the risk for mobility decline. Understanding how mobility declines is paramount to finding ways...

  5. Maximum likely scale estimation

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo


    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  6. 基于最小费用最大流理论的 CCN 多路径路由算法%A Multipath Routing Algorithm for CCN Networks Based on the Minimum Cost Maximum Flow Theory

    雷苏娇; 李俊; 吴海博; 冯宗明


    Multipath routing is a new feature in CCN (Content-Centric Networking) which can be used to enhance the efifciency of network resources usage and balance network congestion. Based on the minimum cost maximum flow theory, we propose a multipath routing algorithm which aims to minimize delay and maximize bandwidth. It can choose different routing paths automatically according to the difference of network bandwidth environment and delay between links to achieve optimal bandwidth utilization of the entire network. The simulation experiment shows that our algorithm can reduce packet loss rate, decrease the bottleneck link load by approximately 60%, and alleviate network congestion.%在CCN (Content-Centric Networking,内容中心网络)中,多路径路由是一个新的特性,采用多路径路由可以更高效地利用网络资源,平衡网络拥塞。本文基于最小费用最大流理论,提出了一种适用于CCN网络的最小时延最大带宽多路径路由算法。该算法可以根据网络链路的带宽差异和链路的时延来选择不同的路由路径,达到整个网络的带宽最优利用。仿真实验表明,该算法与最短路径算法相比可以减少网络丢包,将瓶颈链路的负载量降低60%左右,缓解网络拥塞。

  7. International Prostatic Symptom Score-voiding/storage subscore ratio in association with total prostatic volume and maximum flow rate is diagnostic of bladder outlet-related lower urinary tract dysfunction in men with lower urinary tract symptoms.

    Yuan-Hong Jiang

    Full Text Available OBJECTIVES: The aim of this study was to investigate the predictive values of the total International Prostate Symptom Score (IPSS-T and voiding to storage subscore ratio (IPSS-V/S in association with total prostate volume (TPV and maximum urinary flow rate (Qmax in the diagnosis of bladder outlet-related lower urinary tract dysfunction (LUTD in men with lower urinary tract symptoms (LUTS. METHODS: A total of 298 men with LUTS were enrolled. Video-urodynamic studies were used to determine the causes of LUTS. Differences in IPSS-T, IPSS-V/S ratio, TPV and Qmax between patients with bladder outlet-related LUTD and bladder-related LUTD were analyzed. The positive and negative predictive values (PPV and NPV for bladder outlet-related LUTD were calculated using these parameters. RESULTS: Of the 298 men, bladder outlet-related LUTD was diagnosed in 167 (56%. We found that IPSS-V/S ratio was significantly higher among those patients with bladder outlet-related LUTD than patients with bladder-related LUTD (2.28±2.25 vs. 0.90±0.88, p1 or >2 was factored into the equation instead of IPSS-T, PPV were 91.4% and 97.3%, respectively, and NPV were 54.8% and 49.8%, respectively. CONCLUSIONS: Combination of IPSS-T with TPV and Qmax increases the PPV of bladder outlet-related LUTD. Furthermore, including IPSS-V/S>1 or >2 into the equation results in a higher PPV than IPSS-T. IPSS-V/S>1 is a stronger predictor of bladder outlet-related LUTD than IPSS-T.

  8. Maximum information photoelectron metrology

    Hockett, P; Wollenhaupt, M; Baumert, T


    Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are a high-information, coherent observable. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, 3D, photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyse the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett et. al., Phys. Rev. Lett. 112, 223001 (2014)] over the main spectral features, but also indicate unexpected symmetry-breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum information measurements of th...

  9. Mitigation of maximum world oil production: Shortage scenarios

    Hirsch, Robert L. [Management Information Services, Inc., 723 Fords Landing Way, Alexandria, VA 22314 (United States)


    A framework is developed for planning the mitigation of the oil shortages that will be caused by world oil production reaching a maximum and going into decline. To estimate potential economic impacts, a reasonable relationship between percent decline in world oil supply and percent decline in world GDP was determined to be roughly 1:1. As a limiting case for decline rates, giant fields were examined. Actual oil production from Europe and North America indicated significant periods of relatively flat oil production (plateaus). However, before entering its plateau period, North American oil production went through a sharp peak and steep decline. Examination of a number of future world oil production forecasts showed multi-year rollover/roll-down periods, which represent pseudoplateaus. Consideration of resource nationalism posits an Oil Exporter Withholding Scenario, which could potentially overwhelm all other considerations. Three scenarios for mitigation planning resulted from this analysis: (1) A Best Case, where maximum world oil production is followed by a multi-year plateau before the onset of a monatomic decline rate of 2-5% per year; (2) A Middling Case, where world oil production reaches a maximum, after which it drops into a long-term, 2-5% monotonic annual decline; and finally (3) A Worst Case, where the sharp peak of the Middling Case is degraded by oil exporter withholding, leading to world oil shortages growing potentially more rapidly than 2-5% per year, creating the most dire world economic impacts. (author)

  10. Maximum Likelihood Associative Memories

    Gripon, Vincent; Rabbat, Michael


    Associative memories are structures that store data in such a way that it can later be retrieved given only a part of its content -- a sort-of error/erasure-resilience property. They are used in applications ranging from caches and memory management in CPUs to database engines. In this work we study associative memories built on the maximum likelihood principle. We derive minimum residual error rates when the data stored comes from a uniform binary source. Second, we determine the minimum amo...

  11. Maximum likely scale estimation

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo


    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and....../or having different derivative orders. Although the principle is applicable to a wide variety of image models, the main focus here is on the Brownian model and its use for scale selection in natural images. Furthermore, in the examples provided, the simplifying assumption is made that the behavior...... of the measurements is completely characterized by all moments up to second order....

  12. Economics and Maximum Entropy Production

    Lorenz, R. D.


    Price differentials, sales volume and profit can be seen as analogues of temperature difference, heat flow and work or entropy production in the climate system. One aspect in which economic systems exhibit more clarity than the climate is that the empirical and/or statistical mechanical tendency for systems to seek a maximum in production is very evident in economics, in that the profit motive is very clear. Noting the common link between 1/f noise, power laws and Self-Organized Criticality with Maximum Entropy Production, the power law fluctuations in security and commodity prices is not inconsistent with the analogy. There is an additional thermodynamic analogy, in that scarcity is valued. A commodity concentrated among a few traders is valued highly by the many who do not have it. The market therefore encourages via prices the spreading of those goods among a wider group, just as heat tends to diffuse, increasing entropy. I explore some empirical price-volume relationships of metals and meteorites in this context.

  13. Canton Fair: Decline, but Optimistic


    @@ The Canton Fair, long regarded as an important weather vane for China's foreign trade, this year faced bitter, cold winds. Trade volume of main "export products such as machines and light industrial products all saw a decline, although the degree of decline differed in different sectors. The total trade volume in this Canton Fair dropped 16.9% below the previous one.

  14. Maximum Entropy Fundamentals

    F. Topsøe


    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  15. Regularized maximum correntropy machine

    Wang, Jim Jing-Yan


    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  16. Ecological consequences of sea-ice decline.

    Post, Eric; Bhatt, Uma S; Bitz, Cecilia M; Brodie, Jedediah F; Fulton, Tara L; Hebblewhite, Mark; Kerby, Jeffrey; Kutz, Susan J; Stirling, Ian; Walker, Donald A


    After a decade with nine of the lowest arctic sea-ice minima on record, including the historically low minimum in 2012, we synthesize recent developments in the study of ecological responses to sea-ice decline. Sea-ice loss emerges as an important driver of marine and terrestrial ecological dynamics, influencing productivity, species interactions, population mixing, gene flow, and pathogen and disease transmission. Major challenges in the near future include assigning clearer attribution to sea ice as a primary driver of such dynamics, especially in terrestrial systems, and addressing pressures arising from human use of arctic coastal and near-shore areas as sea ice diminishes.

  17. Equalized near maximum likelihood detector


    This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.

  18. Generalized Maximum Entropy

    Cheeseman, Peter; Stutz, John


    A long standing mystery in using Maximum Entropy (MaxEnt) is how to deal with constraints whose values are uncertain. This situation arises when constraint values are estimated from data, because of finite sample sizes. One approach to this problem, advocated by E.T. Jaynes [1], is to ignore this uncertainty, and treat the empirically observed values as exact. We refer to this as the classic MaxEnt approach. Classic MaxEnt gives point probabilities (subject to the given constraints), rather than probability densities. We develop an alternative approach that assumes that the uncertain constraint values are represented by a probability density {e.g: a Gaussian), and this uncertainty yields a MaxEnt posterior probability density. That is, the classic MaxEnt point probabilities are regarded as a multidimensional function of the given constraint values, and uncertainty on these values is transmitted through the MaxEnt function to give uncertainty over the MaXEnt probabilities. We illustrate this approach by explicitly calculating the generalized MaxEnt density for a simple but common case, then show how this can be extended numerically to the general case. This paper expands the generalized MaxEnt concept introduced in a previous paper [3].

  19. Cognitive decline affects diabetic women

    Perzyński Adam


    Full Text Available Introduction: DM provokes peripheral complications and changes in central nervous system. Central changes in the course of diabetes mellitus (DM include changes in brain tissue structure, electrophysiological abnormalities but also disturbances in neurotransmission leading to cognitive decline.

  20. Dispersal and gene flow in the rare, parasitic Large Blue butterfly Maculinea arion

    Ugelvig, Line Vej; Andersen, Anne; Boomsma, Jacobus Jan


    decline throughout Europe and extinction in Britain followed by reintroduction of a seed population from the Swedish island of Öland. We find that populations are highly structured genetically, but that gene flow occurs over distances 15 times longer than the maximum distance recorded from mark...

  1. Modifications of the maximum expiratory flow in bronchial asthma treatment using Intal and Ketotifeno. Modificaciones del flujo expiratorio máximo en el tratamiento del asma bronquial con intal y ketotifeno.

    Marylin Aroche Quintana


    Full Text Available Introduction: The studies of the lung function are essential for the diagnosis, classification and treatment of the Bronchial Asthma and inside them the mensuration of the flow maximum expiratory (FEM it provides a quantitative value of the obstruction of the air roads. Methods: It was carried out a study in two stages, the first one descriptive in which was included the 15 year-old patients and more with diagnostic of Bronchial Asthma and belonging to the CMF #26 of the Policlínico Area V of the Municipality Cienfuegos, with the objective of determining the modifications of the value of the FEM according to outline of treatment used intercrisis. The sample was constituted for 37 patients, to those that were applied a form of data where it was included the age, sex, clinical characteristics of its illness and the current treatment. In the second stage two groups were created selected by the simple random method. The first one received treatment with Intal Spray (four aplications per day and the second with Ketotifeno (tab. 1 mg. /2tab par day egining to make mensurations from FEM to the three, six, nine and twelve months of having implemented the treatment. Results: They in our patient prevailed the ages of 15- 24 years and of 25- 34 years and the feminine sex, the Salbutamol was the more utilized in the previous treatments, initially the greater number of asthmatic they were classified like moderates and upon concluding the 12mo month the 72.9% they of the total of the pattern behaved like light; they with both treatments improved the courages of FEM, although the group of patient that you received treatment with Intal you showed an improvement in statements security much more rapid. Conclusions: That patient that they utilized Intal had a more rapid elevation of the FEM.

    Introducción: Los estudios de la función pulmonar son

  2. Cognitive decline and amyloid accumulation in patients with mild cognitive impairment

    Koivunen, Jaana; Karrasch, Mira; Scheinin, Noora M


    was associated with faster decline in verbal learning. Higher baseline uptake in the caudate nucleus was related to faster decline in memory consolidation, and higher temporal uptake was associated with decline in executive function. Conclusion: Higher (11)C-PIB uptake in the caudate nucleus and temporal lobe...... was related to decline in memory and executive functions, whereas lower frontal uptake was related to decline in verbal learning. The results indicate that in prodromal AD, frontal amyloid accumulation reaches its maximum in the MCI stage, characterized by memory problems without full-blown dementia....

  3. Maximum Profit Configurations of Commercial Engines

    Yiran Chen


    An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m)] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by t...

  4. Bibliography on Decline and Retrenchment.

    National Center for Higher Education Management Systems, Boulder, CO.

    A bibliography on decline and retrenchment in higher education is presented that includes publications from the fields of higher education, the organization sciences, and public administration. The objective is to make available the reference tools that have been useful in conducting the National Center for Higher Education Management Systems'…

  5. Declining Enrollment--A Blessing.

    Imhof, Howard E.

    This report describes how a New York school district took advantage of a decline in elementary school enrollment to restructure the district's educational program, reduce staff requirements, and eliminate double shifting at the district's junior high and high school. The district's plan involved closing one of the three elementary schools and…

  6. Strong families and declining fertility

    Hilevych, Yuliya


    This dissertation focuses on the role of family and social relationships in individuals’ reproductive careers during the fertility decline in Soviet Ukraine from around 1950 to 1975. These three decades after the Second World War signified the end of the First Demographic Transition in Ukraine

  7. Declining Efficiency in the Economy

    Nørgaard, Jørgen


    The paper discusses the concept of resource efficiency in the economy as a whole. This implies some unfoldings of the simple definition of efficiency as human satisfaction over throughput of resources. It is suggested, that the efficiency of the economic systems is declining in the countries...

  8. French Wines on the Decline?:

    Steiner, Bodo


    French wines, differentiated by geographic origin, served for many decades as a basis for the French success in the British wine market. However in the early 1990s, market share began to decline. This article explores the values that market participants placed on labelling information on French...

  9. Chinese culture and fertility decline.

    Wu, C; Jia, S


    Coale has suggested that cultural factors exert a significant influence on fertility reduction; countries in the "Chinese cultural circle" would be the first to show fertility decline. In China, the view was that traditional Chinese culture contributed to increased population. This paper examines the nature of the relationship between Chinese culture and fertility. Attention was directed to a comparison of fertility rates of developing countries with strong Chinese cultural influence and of fertility within different regions of China. Discussion was followed by an explanation of the theoretical impact of Chinese culture on fertility and direct and indirect beliefs and practices that might either enhance or hinder fertility decline. Emigration to neighboring countries occurred after the Qing dynasty. Fertility after the 1950s declined markedly in Japan, Singapore, Hong Kong, South Korea, Taiwan, and mainland China: all countries within the Chinese cultural circle. Other countries within the Chinese circle which have higher fertility, yet lower fertility than other non-Chinese cultural countries, are Malaysia, Thailand, and Indonesia. Within China, regions with similar fertility patterns are identified as coastal regions, central plains, and mountainous and plateau regions. The Han ethnic group has lower fertility than that of ethnic minorities; regions with large Han populations have lower fertility. Overseas Chinese in East Asian countries also tend to have lower fertility than their host populations. Chinese culture consisted of the assimilation of other cultures over 5000 years. Fertility decline was dependent on the population's desire to limit reproduction, favorable social mechanisms, and availability of contraception: all factors related to economic development. Chinese culture affects fertility reduction by affecting reproductive views and social mechanisms directly, and indirectly through economics. Confucianism emphasizes collectivism, self

  10. The Most Slowly Declining Type Ia Supernova 2001ay

    Krisciunas, Kevin; Matheson, Thomas; Howell, C Andrew; Stritzinger, Maximilian; Aldering, Greg; Berlind, Perry L; Calkins, M; Challis, Peter; Chornock, Ryan; Conley, Alexander; Filippenko, Alexei V; Ganeshalingam, Mohan; Germany, Lisa; Gonzalez, Sergio; Gooding, Samuel D; Hsiao, Eric; Kasen, Daniel; Kirshner, Robert P; Marion, G H "Howie"; Muena, Cesar; Nugent, Peter E; Phelps, M; Phillips, Mark M; Qiu, Yulei; Quimby, Robert; Rines, K; Silverman, Jeffrey M; Suntzeff, Nicholas B; Thomas, Rollin C; Wang, Lifan


    We present optical and near-infrared photometry, as well as ground-based optical spectra and Hubble Space Telescope ultraviolet spectra, of the Type Ia supernova (SN) 2001ay. At maximum light the Si II and Mg II lines indicated expansion velocities of 14,000 km/sec, while Si III and S II showed velocities of 9,000 km/sec There is also evidence for some unburned carbon at 12,000 km/sec. SN 2001ay exhibited a decline-rate parameter Delta m_15(B) = 0.68 \\pm 0.05 mag; this and the B-band photometry at t > +25 d past maximum make it the most slowly declining Type Ia SN yet discovered. Three of four super-Chandrasekhar-mass candidates have decline rates almost as slow as this. After correction for Galactic and host-galaxy extinction, SN 2001ay had M_B = -19.19 and M_V = -19.17 mag at maximum light; thus, it was not overluminous in optical bands. In near-infrared bands it was overluminous only at the 2-sigma level at most. For a rise time of 18 d (explosion to bolometric maximum) the implied Ni-56 yield was (0.58 \\p...

  11. The cultural evolution of fertility decline

    Colleran, Heidi


    Cultural evolutionists have long been interested in the problem of why fertility declines as populations develop. By outlining plausible mechanistic links between individual decision-making, information flow in populations and competition between groups, models of cultural evolution offer a novel and powerful approach for integrating multiple levels of explanation of fertility transitions. However, only a modest number of models have been published. Their assumptions often differ from those in other evolutionary approaches to social behaviour, but their empirical predictions are often similar. Here I offer the first overview of cultural evolutionary research on demographic transition, critically compare it with approaches taken by other evolutionary researchers, identify gaps and overlaps, and highlight parallel debates in demography. I suggest that researchers divide their labour between three distinct phases of fertility decline—the origin, spread and maintenance of low fertility—each of which may be driven by different causal processes, at different scales, requiring different theoretical and empirical tools. A comparative, multi-level and mechanistic framework is essential for elucidating both the evolved aspects of our psychology that govern reproductive decision-making, and the social, ecological and cultural contingencies that precipitate and sustain fertility decline. PMID:27022079

  12. Cardiovascular Prevention of Cognitive Decline

    Jean-Jacques Monsuez


    Full Text Available Midlife cardiovascular risk factors, including diabetes, hypertension, dyslipemia, and an unhealthy lifestyle, have been linked to subsequent incidence, delay of onset, and progression rate of Alzheimer disease and vascular dementia. Conversely, optimal treatment of cardiovascular risk factors prevents and slows down age-related cognitive disorders. The impact of antihypertensive therapy on cognitive outcome in patients with hypertension was assessed in large trials which demonstrated a reduction in progression of MRI white matter hyperintensities, in cognitive decline and in incidence of dementia. Large-scale database correlated statin use and reduction in the incidence of dementia, mainly in patients with documented atherosclerosis, but clinical trials failed to reach similar conclusions. Whether a multitargeted intervention would substantially improve protection, quality of life, and reduce medical cost expenditures in patients with lower risk profile has not been ascertained. This would require appropriately designed trials targeting large populations and focusing on cognitive decline as a primary outcome endpoint.

  13. Decline of radionuclides in Columbia River biota

    Cushing, C.E.; Watson, D.G.; Scott, A.J.; Gurtisen, J.M.


    In January 1971, the last of nine plutonium production reactors using direct discharge of once-through cooling waters into the Columbia River was closed. Sampling was initiated at three stations on the Columbia River to document the decline of the radionuclide body burdens in the biota of the Columbia River ecosystem. The data show that in a river-reservoir complex, the measurable body burden of fission-produced radionuclides decreased to essentially undetectable levels within 18 to 24 mo after cessation of discharge of once-through cooling water into the river. On the basis of data from the free-flowing station, we believe that this decrease would be even more rapid in an unimpounded river.

  14. The method of the maximum entropy for the reconstruction of the distribution bolt the bolt of the neutrons flow in a fuel element; O metodo da maxima entropia para a reconstrucao da distribuicao pino a pino do fluxo de neutrons em um elemento combustivel

    Ancalla, Lourdes Pilar Zaragoza


    The reconstruction of the distribution of density of potency pin upright in a heterogeneous combustible element, of the nucleus of a nuclear reactor, it is a subject that has been studied inside by a long time in Physics of Reactors area. Several methods exist to do this reconstruction, one of them is Maximum Entropy's Method, that besides being an optimization method that finds the best solution of all the possible solutions, it is a method also improved that uses multipliers of Lagrange to obtain the distribution of the flows in the faces of the combustible element. This distribution of the flows in the faces is used then as a contour condition in the calculations of a detailed distribution of flow inside the combustible element. In this work, in first place it was made the homogenization of the heterogeneous element. Soon after the factor of the multiplication executes and the medium values of the flow and of the liquid current they are computed, with the program NEM2D. These values medium nodal are, then, used upright in the reconstruction of the distribution pin of the flow inside the combustible element. The obtained results were acceptable, when compared with those obtained using fine mesh. (author)

  15. The fertility decline in Kenya.

    Robinson, W C; Harbison, S F


    In Sub-Saharan Africa Kenya is a prime example of a country experiencing a rapid decline in fertility and greater contraceptive prevalence. These changes have occurred since 1980 when fertility was high at 8.0 children per woman. In 1993 the total fertility rate (TFR) was 5.4, and the growth rate declined to about 2.0%. This transition is swifter than any country in contemporary Asia or historical Europe. The likely projection for Kenya is attainment of replacement level fertility during the 2020s and a leveling of population at about 100 million persons. Fertility has declined the most in urban areas and central and eastern regions. Bongaarts' proximate determinants (TFR, total marital fertility rate, total natural marital fertility rate, and total fecundity) are reduced to the proportion of currently married women using contraception, the proportion in lactational nonfecund status, and the proportion currently married. Actual fertility change is accounted for by total fertility change of 3.0 children. Lactational infecundability accounts for 0.5 potential births, and changes in marital fertility account for 1.0 reduced births per woman. About 70% of fertility reduction is accounted for by contraception and abortion. During 1977-78 80% of fertility control was due to lactational nonfecundity, 10% to nonmarriage, and 10% to contraception. In 1993 lactational nonfecundity accounted for 50% of the reduction, nonmarriage for 20%, and abortion about 30%. Future fertility is expected to be dependent on contraceptive prevalence. Kenya has experienced the Coale paradigm of preconditions necessary for demographic transition (willing, ready, and able). High fertility in Africa is not intractable. Creating the change in attitudes that leads to readiness is linked to education, health, and exposure to modernizing media and urban lifestyles. The public sector family planning program in Kenya has created the opportunity for access and availability of contraception. The key

  16. Declining Efficiency in the Economy

    Nørgaard, Jørgen


    The paper discusses the concept of resource efficiency in the economy as a whole. This implies some unfoldings of the simple definition of efficiency as human satisfaction over throughput of resources. It is suggested, that the efficiency of the economic systems is declining in the countries...... with a high material standard of living. Examples are presented as are suggestions for how to improve the efficiency. These improvements, however, have a tendency to reduce the gross domestic product and hence are conflicting with the conventional political goals of growing GDP....

  17. OECD Maximum Residue Limit Calculator

    With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.

  18. Clinical value of urine flow acceleration and maximum urinary flow-rate in diagnosing bladder outlet obstruction of patients with benign prostate hyperplasia%尿流加速度和最大尿流率诊断膀胱出口梗阻的价值

    文建国; 崔林刚; 孟庆军; 任川川; 李金升; 吕宇涛; 张艳


    目的 比较尿流加速度(UFA)和最大尿流率(Qmax)诊断膀胱出口梗阻(BOO)的价值. 方法 分别选取50例前列腺增生(BPH)患者和50例健康者进行前列腺体积、UFA和Qmax测定.以P-Q图梗阻区作为参考标准,比较UFA和Qmax诊断BOO的灵敏度和特异性. 结果 BPH组UFA明显低于非BPH组(P<0.05).以UFA<2 ml/s2和Qmax<10 ml/s作为诊断BOO参考标准,灵敏度和特异度分别为88%、75%与81%、63%,与参考标准P-Q图提示梗阻一致性分析Kappa值分别为0.55比0.35. 结论 UFA可以作为诊断BPH患者BOO的依据之一.%Objective To assess the value of the urine flow acceleration(UFA)versus maximum urinary flow rate (Qmax) for diagnosis of bladder outlet obstruction (BOO) in benign prostate hyperplasia (BPH).Methods A total of 50 men with BPH and 50 normal men were included in this study.Urodynamic examinations were performed in all patients according to the recommendations of the International Continence Society.Prostate volume,UFA and Qmax of each patient were analyzed and the results were compared between two groups.Results The UFA and Qmax of BPH group were much lower than that of the control group [(2.05±0.85)ml/s2 vs.(4.60±1.25)ml/s2 ; (8.50±1.05)ml/s vs.(13.00±3.35)ml/s,P<0.05].The prostate volume in BPH group was increased compared with control group [(28.6±9.8) ml vs.(24.2±7.6)ml,P<0.05].As diagnosis standard of UFA<2.05 ml/s2 and Qmax< 10 ml/s,the sensitivity and specificity of UFA and Qmax in diagnosing BOO were (88%,75 %)vs.(81%,63%).While compared with the result of P-Q chart,the Kappa values in correspondence analysis were 0.55 vs.0.35.The sensitivity,specificity and Kappa value of UFA in diagnosing BOO in BPHs were slightly higher than that of Qmax in comparison with the gold standard (BOO diagnosed by P-Q figure).Conclusions The UFA is a useful urodynamics parameter in diagnosing BOO of BPH.

  19. Maximum Profit Configurations of Commercial Engines

    Yiran Chen


    Full Text Available An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by the initial conditions and the inherent characteristics of two subsystems; while the different ways of transfer affect the model in respects of the specific forms of the paths of prices and the instantaneous commodity flow, i.e., the optimal configuration.

  20. Maximum ceasing angle of inclination and flux formula for granular orifice flow%颗粒孔洞流的最大休止倾角和流量公式

    彭政; 蒋亦民


    This work measured mass flux of a granular sample (glass beads) discharged from an inclined orifice for various inclination angles and orifice diameters. It is found that irrespective the orifice sizes, the fluxes all vary linearly with cosine of the inclination angle, and the linearly extrapolated angle of zero-flux, namely the critical angle of flow ceasing,increases linearly with ratio between grain and orifice diameter, tends to the angle of repose in the limit of infinite orifice diameter within an approximation of the Bagnold angle. The results show that the flux formula varying linearly with cosine of inclination angle is capable to reveal behaviors of the critical ceasing angle, a property that the Beverloo formula of which parameters vary with cosine of inclination angle can not describe.%实验测量了重力驱动下的玻璃珠颗粒样品通过不同倾角和孔径的圆形孔洞的卸载流量.发现无论孔径大小,流量均与倾角的余弦呈良好的线性关系;线性外推得到的零流量角,即流量休止临界角随颗粒粒径与孔洞直径之比的减小而线性增加;在无穷大孔径极限下,此临界角在Bagnold角的误差范围内与样品的安息角一致.这些结果表明流量随倾角余弦线性变化的经验公式能揭示临界角的行为和特性,这是参数随倾角变化的Beverloo公式所不能描述的.

  1. Decline Curve Analysis for Production Forecast and Optimization of Liquid-Dominated Geothermal Reservoir

    Hidayat, I.


    Power projects in the geothermal field has a long span of about 30 years. The power supply should be maintained at a certain value across a range of time. A geothermal field, however, has the characteristics of natural production decline with time. In a geothermal field, development of decline curve model of steam production is important for forecasting production decline in the future. This study was developed using decline curve by production data along 3 years liquid-dominated geothermal reservoir in Ulubelu field. Decline curve in geothermal field based on decline curve in petroleum industry. The decline curve was correlated by reservoir management in geothermal. The purposes of this study to get best match model decline curve and forecasting production in the future. Based on decline curve analysis by production data in Ulubelu field, the result model decline curve is exponential model. From the model, we can get the value of decline rate in the field is 9.4 %/year. Then, the formula of forecasting steam flow used exponent decline to forecast in the future. By using separated system cycle in Ulubelu field, the minimal steam flowrate towards turbine was 502018.4 ton/month. Based on formula of forecasting production and minimal steam flowrate, we can get the time make up wells to maintain steam supply for stability in generator power capacity.

  2. Climate Variations and Alaska Tundra Vegetation Productivity Declines in Spring

    Bhatt, U. S.; Walker, D. A.; Bieniek, P.; Raynolds, M. K.; Epstein, H. E.; Comiso, J. C.; Pinzon, J. E.; Tucker, C. J.


    While sea ice has continued to decline, vegetation productivity increases have declined particularly during spring in Alaska as well as many parts of the Arctic tundra. To understand the processes behind these features we investigate spring climate variations that includes temperature, circulation patterns, and snow cover to determine how these may be contributing to spring browning. This study employs remotely sensed weekly 25-km sea ice concentration, weekly surface temperature, and bi-weekly NDVI from 1982 to 2014. Maximum NDVI (MaxNDVI, Maximum Normalized Difference Vegetation Index), Time Integrated NDVI (TI-NDVI), Summer Warmth Index (SWI, sum of degree months above freezing during May-August), atmospheric reanalysis data, dynamically downscaled climate data, meteorological station data, and snow water equivalent (GlobSnow, assimilated snow data set). We analyzed the data for the full period (1982-2014) and for two sub-periods (1982-1998 and 1999-2014), which were chosen based on the declining Alaska SWI since 1998. MaxNDVI has increased from 1982-2014 over most of the Arctic but has declined from 1999 to 2014 southwest Alaska. TI-NDVI has trends that are similar to those for MaxNDVI for the full period but display widespread declines over the 1999-2014 period. Therefore, as the MaxNDVI has continued to increase overall for the Arctic, TI-NDVI has been declining since 1999 and these declines are particularly noteworthy during spring in Alaska. Spring declines in Alaska have been linked to increased spring snow cover that can delay greenup (Bieniek et al. 2015) but recent ground observations suggest that after an initial warming and greening, late season freezing temperature are damaging the plants. The late season freezing temperature hypothesis will be explored with meteorological climate/weather data sets for Alaska tundra regions. References P.A. Bieniek, US Bhatt, DA Walker, MK Raynolds, JC Comiso, HE Epstein, JE Pinzon, CJ Tucker, RL Thoman, H Tran, N M

  3. Can Occupational Therapy Slow Alzheimer's Decline?

    ... news/fullstory_162135.html Can Occupational Therapy Slow Alzheimer's Decline? Patients, caregivers may reap some benefits, but ... slow down the physical decline that comes with Alzheimer's disease, a new clinical trial suggests. The study ...

  4. Who fears and who welcomes population decline?

    Hendrik P. Van Dalen


    Full Text Available European countries are experiencing population decline and the tacit assumption in most analyses is that the decline may have detrimental welfare effects. In this paper we use a survey among the population in the Netherlands to discover whether population decline is always met with fear. A number of results stand out: population size preferences differ by geographic proximity: at a global level the majority of respondents favors a (global population decline, but closer to home one supports a stationary population. Population decline is clearly not always met with fear: 31 percent would like the population to decline at the national level and they generally perceive decline to be accompanied by immaterial welfare gains (improvement environment as well as material welfare losses (tax increases, economic stagnation. In addition to these driving forces it appears that the attitude towards immigrants is a very strong determinant at all geographical levels: immigrants seem to be a stronger fear factor than population decline.

  5. Nonlinear decline-rate dependence and intrinsic variation of typeIa supernova luminosities

    Wang, Lifan; Strovink, Mark; Conley, Alexander; Goldhaber,Gerson; Kowalski, Marek; Perlmutter, Saul; Siegrist, James


    Published B and V fluxes from nearby Type Ia supernova are fitted to light-curve templates with 4-6 adjustable parameters. Separately, B magnitudes from the same sample are fitted to a linear dependence on B-V color within a post-maximum time window prescribed by the CMAGIC method. These fits yield two independent SN magnitude estimates B{sub max} and B{sub BV}. Their difference varies systematically with decline rate {Delta}m{sub 15} in a form that is compatible with a bilinear but not a linear dependence; a nonlinear form likely describes the decline-rate dependence of B{sub max} itself. A Hubble fit to the average of B{sub max} and B{sub BV} requires a systematic correction for observed B-V color that can be described by a linear coefficient R = 2.59 {+-} 0.24, well below the coefficient R{sub B} {approx} 4.1 commonly used to characterize the effects of Milky Way dust. At 99.9% confidence the data reject a simple model in which no color correction is required for SNe that are clustered at the blue end of their observed color distribution. After systematic corrections are performed, B{sub max} and B{sub BV} exhibit mutual rms intrinsic variation equal to 0.074 {+-} 0.019 mag, of which at least an equal share likely belongs to B{sub BV}. SN magnitudes measured using maximum-luminosity or cmagic methods show comparable rms deviations of order {approx}0.14 mag from the Hubble line. The same fit also establishes a 95% confidence upper limit of 486 km s{sup -1} on the rms peculiar velocity of nearby SNe relative to the Hubble flow.

  6. Decline in breast cancer mortality

    Njor, Sisse Helle; Schwartz, Walter; Blichert-Toft, Mogens


    OBJECTIVES: When estimating the decline in breast cancer mortality attributable to screening, the challenge is to provide valid comparison groups and to distinguish the screening effect from other effects. In Funen, Denmark, multidisciplinary breast cancer management teams started before screening...... was introduced; both activities came later in the rest of Denmark. Because Denmark had national protocols for breast cancer treatment, but hardly any opportunistic screening, Funen formed a "natural experiment", providing valid comparison groups and enabling the separation of the effect of screening from other...... factors. METHODS: Using Poisson regression we compared the observed breast cancer mortality rate in Funen after implementation of screening with the expected rate without screening. The latter was estimated from breast cancer mortality in the rest of Denmark controlled for historical differences between...

  7. Declining Sunshine for Phoenix Lander


    The yellow line on this graphic indicates the number of hours of sunlight each sol, or Martian day, at the Phoenix landing site's far-northern latitude, beginning with the entire Martian day (about 24 hours and 40 minutes) for the first 90 sols, then declining to no sunlight by about sol 300. The blue tick mark indicates that on Sol 124 (Sept. 29, 2008), the sun is above the horizon for about 20 hours. The brown vertical bar represents the period from Nov. 18 to Dec. 24, 2008, around the 'solar conjunction,' when the sun is close to the line between Mars and Earth, affecting communications. The green vertical rectangle represents the period from February to November 2009 when the Phoenix lander is expected to be encased in carbon-dioxide ice.

  8. Maximum margin Bayesian network classifiers.

    Pernkopf, Franz; Wohlmayr, Michael; Tschiatschek, Sebastian


    We present a maximum margin parameter learning algorithm for Bayesian network classifiers using a conjugate gradient (CG) method for optimization. In contrast to previous approaches, we maintain the normalization constraints on the parameters of the Bayesian network during optimization, i.e., the probabilistic interpretation of the model is not lost. This enables us to handle missing features in discriminatively optimized Bayesian networks. In experiments, we compare the classification performance of maximum margin parameter learning to conditional likelihood and maximum likelihood learning approaches. Discriminative parameter learning significantly outperforms generative maximum likelihood estimation for naive Bayes and tree augmented naive Bayes structures on all considered data sets. Furthermore, maximizing the margin dominates the conditional likelihood approach in terms of classification performance in most cases. We provide results for a recently proposed maximum margin optimization approach based on convex relaxation. While the classification results are highly similar, our CG-based optimization is computationally up to orders of magnitude faster. Margin-optimized Bayesian network classifiers achieve classification performance comparable to support vector machines (SVMs) using fewer parameters. Moreover, we show that unanticipated missing feature values during classification can be easily processed by discriminatively optimized Bayesian network classifiers, a case where discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.

  9. Maximum Entropy in Drug Discovery

    Chih-Yuan Tseng


    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  10. Declining caries trends: are we satisfied?

    M.D. Lagerweij; C. van Loveren


    WHO data suggest that all over the world the prevalence of caries has declined at the end of the previous and in the first decade of the present century. This decline started wherever the use of effective fluoride toothpaste became commonplace. Even though the decline is considerable with a 90 % red

  11. Declining caries trends: are we satisfied?

    Lagerweij, M.D.; van Loveren, C.


    WHO data suggest that all over the world the prevalence of caries has declined at the end of the previous and in the first decade of the present century. This decline started wherever the use of effective fluoride toothpaste became commonplace. Even though the decline is considerable with a 90 %

  12. The Maximum Density of Water.

    Greenslade, Thomas B., Jr.


    Discusses a series of experiments performed by Thomas Hope in 1805 which show the temperature at which water has its maximum density. Early data cast into a modern form as well as guidelines and recent data collected from the author provide background for duplicating Hope's experiments in the classroom. (JN)

  13. Abolishing the maximum tension principle

    Dabrowski, Mariusz P


    We find the series of example theories for which the relativistic limit of maximum tension $F_{max} = c^2/4G$ represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.

  14. Abolishing the maximum tension principle

    Mariusz P. Da̧browski


    Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.

  15. Maximum Genus of Strong Embeddings

    Er-ling Wei; Yan-pei Liu; Han Ren


    The strong embedding conjecture states that any 2-connected graph has a strong embedding on some surface. It implies the circuit double cover conjecture: Any 2-connected graph has a circuit double cover.Conversely, it is not true. But for a 3-regular graph, the two conjectures are equivalent. In this paper, a characterization of graphs having a strong embedding with exactly 3 faces, which is the strong embedding of maximum genus, is given. In addition, some graphs with the property are provided. More generally, an upper bound of the maximum genus of strong embeddings of a graph is presented too. Lastly, it is shown that the interpolation theorem is true to planar Halin graph.

  16. [Concentration or decline in Puebla?].

    Cabrera Becerra, V


    Some doubts have been expressed over whether the slowing pace of urbanization suggested by the 1990 census of Mexico was an accurate reflection of changing conditions, or whether it resulted from some intentional or unintended bias. Comparison of data from succeeding censuses indicates that the growth rate of the city of Puebla declined from 6.32% in 1980 to 2.63% in 1990. This work argues that, in Puebla, a trend to deconcentration of the population within the city of Puebla during the 1980s was accompanied by rapid growth in smaller and medium sized nearby cities, resulting in increased overall concentration in Puebla's metropolitan area. The absolute population of the city of Puebla increased from 772,908 in 1980 to 1,007,170 in 1990. The central area of the state of Puebla, which surrounds the city, increased its share of the state population from 51.67% in 1980 to 52.21% in 1990. The number of places with over 5000 inhabitants in the area surrounding the city of Puebla increased from 27 in 1980 to 39 in 1990. Construction of the Puebla-Atlixco highway will undoubtedly attract growth to the area southwest of Puebla. Small cities to the east of Puebla have shown significant growth although their region remains strongly rural. The same process of deconcentration of population in Puebla and concentration in its surrounding metropolitan regions can probably also be detected in patterns of investment of public funds. The trend is likely to continue through the 1990s.

  17. D(Maximum)=P(Argmaximum)

    Remizov, Ivan D


    In this note, we represent a subdifferential of a maximum functional defined on the space of all real-valued continuous functions on a given metric compact set. For a given argument, $f$ it coincides with the set of all probability measures on the set of points maximizing $f$ on the initial compact set. This complete characterization lies in the heart of several important identities in microeconomics, such as Roy's identity, Sheppard's lemma, as well as duality theory in production and linear programming.

  18. The Change in the Maximum Wind Speed and the Impact of it on Agricultural Production

    WU Jian-mei; SUN Jin-sen; SUI Gui-ling; XIE Su-he; WANG Meng


    Using the data on the maximum wind speed within ten minutes every month in the period 1971-2009 in Zhucheng City of Shandong Province, we conduct statistical analysis of the maximum wind speed in Zhucheng City. The results show that over thirty-nine years, the annual maximum wind speed in four seasons in Zhucheng City tends to decline. The annual maximum wind speed declines at the rate of 1.45 m/s every 10 years. It falls fastest in winter, with decline rate of 1.73 m/s every 10 years; it is close to the average annual maximum wind speed in spring and autumn, with decline rate of 1.44 m/s and 14.8 m/s every 10 years, respectively; it falls slowest in summer, and the extreme value of the maximum wind speed occurs mainly in spring. The curve of changes in the monthly maximum wind speed in Zhucheng City assumes diminishing shape of "two peaks and one trough". We conduct preliminary analysis of the windy weather situation, and put forth specific defensive measures against the hazards of strong winds in the different periods.

  19. Mass mortality of the vermetid gastropod Ceraesignum maximum

    Brown, A. L.; Frazer, T. K.; Shima, J. S.; Osenberg, C. W.


    Ceraesignum maximum (G.B. Sowerby I, 1825), formerly Dendropoma maximum, was subject to a sudden, massive die-off in the Society Islands, French Polynesia, in 2015. On Mo'orea, where we have detailed documentation of the die-off, these gastropods were previously found in densities up to 165 m-2. In July 2015, we surveyed shallow back reefs of Mo'orea before, during and after the die-off, documenting their swift decline. All censused populations incurred 100% mortality. Additional surveys and observations from Mo'orea, Tahiti, Bora Bora, and Huahine (but not Taha'a) suggested a similar, and approximately simultaneous, die-off. The cause(s) of this cataclysmic mass mortality are currently unknown. Given the previously documented negative effects of C. maximum on corals, we expect the die-off will have cascading effects on the reef community.

  20. The Testability of Maximum Magnitude

    Clements, R.; Schorlemmer, D.; Gonzalez, A.; Zoeller, G.; Schneider, M.


    Recent disasters caused by earthquakes of unexpectedly large magnitude (such as Tohoku) illustrate the need for reliable assessments of the seismic hazard. Estimates of the maximum possible magnitude M at a given fault or in a particular zone are essential parameters in probabilistic seismic hazard assessment (PSHA), but their accuracy remains untested. In this study, we discuss the testability of long-term and short-term M estimates and the limitations that arise from testing such rare events. Of considerable importance is whether or not those limitations imply a lack of testability of a useful maximum magnitude estimate, and whether this should have any influence on current PSHA methodology. We use a simple extreme value theory approach to derive a probability distribution for the expected maximum magnitude in a future time interval, and we perform a sensitivity analysis on this distribution to determine if there is a reasonable avenue available for testing M estimates as they are commonly reported today: devoid of an appropriate probability distribution of their own and estimated only for infinite time (or relatively large untestable periods). Our results imply that any attempt at testing such estimates is futile, and that the distribution is highly sensitive to M estimates only under certain optimal conditions that are rarely observed in practice. In the future we suggest that PSHA modelers be brutally honest about the uncertainty of M estimates, or must find a way to decrease its influence on the estimated hazard.

  1. Alternative Multiview Maximum Entropy Discrimination.

    Chao, Guoqing; Sun, Shiliang


    Maximum entropy discrimination (MED) is a general framework for discriminative estimation based on maximum entropy and maximum margin principles, and can produce hard-margin support vector machines under some assumptions. Recently, the multiview version of MED multiview MED (MVMED) was proposed. In this paper, we try to explore a more natural MVMED framework by assuming two separate distributions p1( Θ1) over the first-view classifier parameter Θ1 and p2( Θ2) over the second-view classifier parameter Θ2 . We name the new MVMED framework as alternative MVMED (AMVMED), which enforces the posteriors of two view margins to be equal. The proposed AMVMED is more flexible than the existing MVMED, because compared with MVMED, which optimizes one relative entropy, AMVMED assigns one relative entropy term to each of the two views, thus incorporating a tradeoff between the two views. We give the detailed solving procedure, which can be divided into two steps. The first step is solving our optimization problem without considering the equal margin posteriors from two views, and then, in the second step, we consider the equal posteriors. Experimental results on multiple real-world data sets verify the effectiveness of the AMVMED, and comparisons with MVMED are also reported.

  2. Entrainment and maximum vapour flow rate of trays

    Van Sinderen, AH; Wijn, EF; Zanting, RWJ

    This is a report on free entrainment measurements in a small (0.20 m x 0.20 in) air-water column. An adjustable weir controlled the liquid height on a test tray. Several sieve and valve trays were studied. The results were interpreted with a two- or three-layer model of the two-phase mixture on the

  3. Perioperative Cognitive Decline in the Aging Population

    Terrando, Niccolò; Brzezinski, Marek; Degos, Vincent; Eriksson, Lars I.; Kramer, Joel H.; Leung, Jacqueline M.; Miller, Bruce L.; Seeley, William W.; Vacas, Susana; Weiner, Michael W.; Yaffe, Kristine; Young, William L.; Xie, Zhongcong; Maze, Mervyn


    Elderly patients who have an acute illness or who undergo surgery often experience cognitive decline. The pathophysiologic mechanisms that cause neurodegeneration resulting in cognitive decline, including protein deposition and neuroinflammation, also play a role in animal models of surgery-induced cognitive decline. With the aging of the population, surgical candidates of advanced age with underlying neurodegeneration are encountered more often, raising concerns that, in patients with this combination, cognitive function will precipitously decline postoperatively. This special article is based on a symposium that the University of California, San Francisco, convened to explore the contributions of surgery and anesthesia to the development of cognitive decline in the aged patient. A road map to further elucidate the mechanisms, diagnosis, risk factors, mitigation, and treatment of postoperative cognitive decline in the elderly is provided. PMID:21878601

  4. Review on Causes of Forest Decline



    Site degradation and yield decline of forest have attracted increasing attention from forest managers and scientists. Studies conducted by researchers from a variety of disciplines and perspectives have led to a variety of competing hypotheses concerning the causes of the problem. In this paper we review evidence of such a yield decline and examine the problem and its possible way to identify the individual contributions of the many determinants of yield decline, and their interactions.

  5. Cacti with maximum Kirchhoff index

    Wang, Wen-Rui; Pan, Xiang-Feng


    The concept of resistance distance was first proposed by Klein and Randi\\'c. The Kirchhoff index $Kf(G)$ of a graph $G$ is the sum of resistance distance between all pairs of vertices in $G$. A connected graph $G$ is called a cactus if each block of $G$ is either an edge or a cycle. Let $Cat(n;t)$ be the set of connected cacti possessing $n$ vertices and $t$ cycles, where $0\\leq t \\leq \\lfloor\\frac{n-1}{2}\\rfloor$. In this paper, the maximum kirchhoff index of cacti are characterized, as well...

  6. Generic maximum likely scale selection

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo


    The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...... on second order moments of multiple measurements outputs at a fixed location. These measurements, which reflect local image structure, consist in the cases considered here of Gaussian derivatives taken at several scales and/or having different derivative orders....

  7. Aging, Terminal Decline, and Terminal Drop

    Palmore, Erdman; Cleveland, William


    Data from a 20-year longitudinal study of persons over 60 were analyzed by step-wise multiple regression to test for declines in function with age, for terminal decline (linear relationship to time before death), and for terminal drop (curvilinear relationship to time before death). There were no substantial terminal drop effects. (Author)

  8. NIDI scenario. Strong population decline in China

    de Beer, J.A.A.


    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario projects less population growth in Nigeria and sharp population decline in China.

  9. How China Survives a Global Economic Decline


    Dark clouds are looming over the global economy. The Euro zone may only manage a paltry 1.5 percent growth next year. Meanwhile in the United States, labor, residential and consumer markets have all experienced a decline in growth. With rising fuel prices, a growing debt burden and a negative savings rate, the United States also is poised for further decline in consumption.

  10. Multitime maximum principle approach of minimal submanifolds and harmonic maps

    Udriste, Constantin


    Some optimization problems coming from the Differential Geometry, as for example, the minimal submanifolds problem and the harmonic maps problem are solved here via interior solutions of appropriate multitime optimal control problems. Section 1 underlines some science domains where appear multitime optimal control problems. Section 2 (Section 3) recalls the multitime maximum principle for optimal control problems with multiple (curvilinear) integral cost functionals and $m$-flow type constraint evolution. Section 4 shows that there exists a multitime maximum principle approach of multitime variational calculus. Section 5 (Section 6) proves that the minimal submanifolds (harmonic maps) are optimal solutions of multitime evolution PDEs in an appropriate multitime optimal control problem. Section 7 uses the multitime maximum principle to show that of all solids having a given surface area, the sphere is the one having the greatest volume. Section 8 studies the minimal area of a multitime linear flow as optimal c...

  11. Objects of maximum electromagnetic chirality

    Fernandez-Corbaton, Ivan


    We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.

  12. Maximum mutual information regularized classification

    Wang, Jim Jing-Yan


    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  13. The strong maximum principle revisited

    Pucci, Patrizia; Serrin, James

    In this paper we first present the classical maximum principle due to E. Hopf, together with an extended commentary and discussion of Hopf's paper. We emphasize the comparison technique invented by Hopf to prove this principle, which has since become a main mathematical tool for the study of second order elliptic partial differential equations and has generated an enormous number of important applications. While Hopf's principle is generally understood to apply to linear equations, it is in fact also crucial in nonlinear theories, such as those under consideration here. In particular, we shall treat and discuss recent generalizations of the strong maximum principle, and also the compact support principle, for the case of singular quasilinear elliptic differential inequalities, under generally weak assumptions on the quasilinear operators and the nonlinearities involved. Our principal interest is in necessary and sufficient conditions for the validity of both principles; in exposing and simplifying earlier proofs of corresponding results; and in extending the conclusions to wider classes of singular operators than previously considered. The results have unexpected ramifications for other problems, as will develop from the exposition, e.g. two point boundary value problems for singular quasilinear ordinary differential equations (Sections 3 and 4); the exterior Dirichlet boundary value problem (Section 5); the existence of dead cores and compact support solutions, i.e. dead cores at infinity (Section 7); Euler-Lagrange inequalities on a Riemannian manifold (Section 9); comparison and uniqueness theorems for solutions of singular quasilinear differential inequalities (Section 10). The case of p-regular elliptic inequalities is briefly considered in Section 11.

  14. Maximum capacities of the 100-B water plant

    Strand, N.O.


    Increases in process water flows will be needed as the current program of increasing pile power levels continues. The future process water flows that will be required are known to be beyond the present maximum capacities of component parts of the water system. It is desirable to determine the present maximum capacities of each major component part so that plans can be mode for modifications and/or additions to the present equipment to meet future required flows. The apparent hydraulic limit of the present piles is about 68,000 gpm. This figure is based on a tube inlet pressure of 400 psi, a tube flow of 34 gpm, and 2,000 effective tubes. In this document the results of tests and calculations to determine the present maximum capacities of each major component part of the 100-B water system will be presented. Emergency steam operated pumps will not be considered as it is doubtful of year around operation of a steam driven pump could be economically justified. Some possible ways to increase the process water flows of each component part of the water system to the ultimate of 68,000 gpm are given.

  15. A comparison of two formulas of topical menthol on vascular responses and perceived intensity prior to and follow a bout of maximum voluntary muscular contractions (MVMCs).

    Topp, Robert; Ng, Alex; Cybulski, Alyson; Skelton, Katalin; Papanek, Paula


    The purpose of this study was to compare the vascular responses in the brachial artery and perceived intensity of two different formulas of topical menthol gels prior to and following a bout of maximum voluntary muscular contractions (MVMCs). 18 adults completed the same protocol on different days using blinded topical menthol gels (Old Formula and New Formula). Heart rate, brachial artery blood flow (ml/min), vessel diameter and reported intensity of sensation were measured at baseline (T1), at 5 min after application of the gel to the upper arm (T2), and immediately following five MVMCs hand grips (T3). The New Formula exhibited a significant decline in blood flow (-22.6%) between T1 and T2 which was not different than the nonsignificant declines under the Old Formula 1 (-21.8%). Both formulas resulted in a significant increase in perceived intensity of sensation between T1 and T2. Blood flow increased significantly with the New Formula (488%) between T2 and T3 and nonsignificantly with the Old Formula (355%).

  16. Asymmetric disassembly and robustness in declining networks.

    Saavedra, Serguei; Reed-Tsochas, Felix; Uzzi, Brian


    Mechanisms that enable declining networks to avert structural collapse and performance degradation are not well understood. This knowledge gap reflects a shortage of data on declining networks and an emphasis on models of network growth. Analyzing >700,000 transactions between firms in the New York garment industry over 19 years, we tracked this network's decline and measured how its topology and global performance evolved. We find that favoring asymmetric (disassortative) links is key to preserving the topology and functionality of the declining network. Based on our findings, we tested a model of network decline that combines an asymmetric disassembly process for contraction with a preferential attachment process for regrowth. Our simulation results indicate that the model can explain robustness under decline even if the total population of nodes contracts by more than an order of magnitude, in line with our observations for the empirical network. These findings suggest that disassembly mechanisms are not simply assembly mechanisms in reverse and that our model is relevant to understanding the process of decline and collapse in a broad range of biological, technological, and financial networks.

  17. Early-Transition Output Decline Revisited

    Crt Kostevc


    Full Text Available In this paper we revisit the issue of aggregate output decline that took place in the early transition period. We propose an alternative explanation of output decline that is applicable to Central- and Eastern-European countries. In the first part of the paper we develop a simple dynamic general equilibrium model that builds on work by Gomulka and Lane (2001. In particular, we consider price liberalization, interpreted as elimination of distortionary taxation, as a trigger of the output decline. We show that price liberalization in interaction with heterogeneous adjustment costs and non-employment benefits lead to aggregate output decline and surge in wage inequality. While these patterns are consistent with actual dynamics in CEE countries, this model cannot generate output decline in all sectors. Instead sectors that were initially taxed even exhibit output growth. Thus, in the second part we consider an alternative general equilibrium model with only one production sector and two types of labor and distortion in a form of wage compression during the socialist era. The trigger for labor mobility and consequently output decline is wage liberalization. Assuming heterogeneity of workers in terms of adjustment costs and non-employment benefits can explain output decline in all industries.

  18. Drivers and moderators of business decline

    Marius Pretorius


    Full Text Available Purpose: Reports of business failure elicit various reactions, while research in this domain often appears to be limited by a lack of access to information about failure and by the negativity that surrounds it. Those who have experienced failure do not readily talk about it, or they disappear from the radar screen of researchers. Yet failure is preceded by decline which, when focused on strategically, can reduce eventual failures if early action is taken. The main purpose of this study is to develop a conceptual framework or typology of the drivers and moderators of business decline. Design/methodology/approach: After applying the "grounded theory" approach to the academic literature on decline and failure, a conceptual framework for the variables that drive and moderate business decline is proposed. Findings: The study proposes that decline has three core drivers, three peripheral drivers and four moderators. The core drivers identified are: resource munificence; leadership as origin; and causality (strategic versus operational origin of decline. The three peripheral drivers are: unique preconditions; continuous decisions impact; and extremes dichotomy. The study describes four moderators of the drivers: life cycle stage; stakeholder perspective; quantitative versus qualitative nature of signs and causes; and finally the age and size effects. Research limitations/implications: The proposed conceptual framework is based on literature only, although it has found support during discussions with practitioners. It is proposed to readers of this journal for scrutiny and validation. Practical implications: Strategists need to understand what drives decline in order to act timeously; practitioners who have an insight into the moderators with their impacts could make better decisions in response to decline in organisations and possibly avoid business failure. Originality/Value: Understanding business decline is still a huge theoretical challenge, which

  19. The decline of hysterectomy for benign disease.

    Horgan, R P


    Hysterectomy is one of the most common gynaecological surgical procedures performed but there appears to be a decline in the performance of this procedure in Ireland in recent times. We set out to establish the extent of the decline of hysterectomy and to explore possible explanations. Data for hysterectomy for benign disease from Ireland was obtained from the Hospital In-Patient Enquiry Scheme (HIPE) section of the Economic and Social Research Institute for the years 1999 to 2006. The total number of hysterectomies performed for benign disease showed a consistent decline during this time. There was a 36% reduction in the number of abdominal hysterectomy procedures performed.

  20. Maximum entropy production in daisyworld

    Maunu, Haley A.; Knuth, Kevin H.


    Daisyworld was first introduced in 1983 by Watson and Lovelock as a model that illustrates how life can influence a planet's climate. These models typically involve modeling a planetary surface on which black and white daisies can grow thus influencing the local surface albedo and therefore also the temperature distribution. Since then, variations of daisyworld have been applied to study problems ranging from ecological systems to global climate. Much of the interest in daisyworld models is due to the fact that they enable one to study self-regulating systems. These models are nonlinear, and as such they exhibit sensitive dependence on initial conditions, and depending on the specifics of the model they can also exhibit feedback loops, oscillations, and chaotic behavior. Many daisyworld models are thermodynamic in nature in that they rely on heat flux and temperature gradients. However, what is not well-known is whether, or even why, a daisyworld model might settle into a maximum entropy production (MEP) state. With the aim to better understand these systems, this paper will discuss what is known about the role of MEP in daisyworld models.

  1. Maximum stellar iron core mass

    F W Giacobbe


    An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is significantly different from a more typical Chandrasekhar mass limit approach. This technique produced a maximum stellar iron core mass value of 2.69 × 1030 kg (1.35 solar masses). This mass value is very near to the typical mass values found for neutron stars in a recent survey of actual neutron star masses. Although slightly lower and higher neutron star masses may also be found, lower mass neutron stars are believed to be formed as a result of enhanced iron core compression due to the weight of non-ferrous matter overlying the iron cores within large stars. And, higher mass neutron stars are likely to be formed as a result of fallback or accretion of additional matter after an initial collapse event involving an iron core having a mass no greater than 2.69 × 1030 kg.

  2. Maximum Matchings via Glauber Dynamics

    Jindal, Anant; Pal, Manjish


    In this paper we study the classic problem of computing a maximum cardinality matching in general graphs $G = (V, E)$. The best known algorithm for this problem till date runs in $O(m \\sqrt{n})$ time due to Micali and Vazirani \\cite{MV80}. Even for general bipartite graphs this is the best known running time (the algorithm of Karp and Hopcroft \\cite{HK73} also achieves this bound). For regular bipartite graphs one can achieve an $O(m)$ time algorithm which, following a series of papers, has been recently improved to $O(n \\log n)$ by Goel, Kapralov and Khanna (STOC 2010) \\cite{GKK10}. In this paper we present a randomized algorithm based on the Markov Chain Monte Carlo paradigm which runs in $O(m \\log^2 n)$ time, thereby obtaining a significant improvement over \\cite{MV80}. We use a Markov chain similar to the \\emph{hard-core model} for Glauber Dynamics with \\emph{fugacity} parameter $\\lambda$, which is used to sample independent sets in a graph from the Gibbs Distribution \\cite{V99}, to design a faster algori...

  3. 76 FR 1504 - Pipeline Safety: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure...


    ...: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure Using Record Evidence, and... facilities of their responsibilities, under Federal integrity management (IM) regulations, to perform... system, especially when calculating Maximum Allowable Operating Pressure (MAOP) or Maximum Operating...

  4. Atrial Fibrillation, Cognitive Decline And Dementia

    Alonso, Alvaro; Arenas de Larriva, Antonio P.


    Atrial fibrillation (AF) is a common cardiac arrhythmia. Growing evidence supports a role for AF as a risk factor for cognitive decline and dementia. In this review, we summarize epidemiologic observations linking AF with cognitive outcomes, describe potential mechanisms, and explore the impact of AF treatments on cognitive decline and dementia. Community-based, observational studies show a consistent higher rate of cognitive decline and risk of dementia in persons with AF. These associations are partly due to the increased risk of clinical stroke in AF, but other mechanisms, including incidence of silent cerebral infarcts, microbleeds, and cerebral hypoperfusion, are likely additional contributors. Adequate oral anticoagulation and improved management of the overall cardiovascular risk profile in persons with AF offer the promise of reducing the impact of AF on cognitive decline and dementia. PMID:27547248

  5. Understanding Amphibian Declines Through Geographic Approaches

    Gallant, Alisa


    Growing concern over worldwide amphibian declines warrants serious examination. Amphibians are important to the proper functioning of ecosystems and provide many direct benefits to humans in the form of pest and disease control, pharmaceutical compounds, and even food. Amphibians have permeable skin and rely on both aquatic and terrestrial ecosystems during different seasons and stages of their lives. Their association with these ecosystems renders them likely to serve as sensitive indicators of environmental change. While much research on amphibian declines has centered on mysterious causes, or on causes that directly affect humans (global warming, chemical pollution, ultraviolet-B radiation), most declines are the result of habitat loss and habitat alteration. Improving our ability to characterize, model, and monitor the interactions between environmental variables and amphibian habitats is key to addressing amphibian conservation. In 2000, the U.S. Geological Survey (USGS) initiated the Amphibian Research and Monitoring Initiative (ARMI) to address issues surrounding amphibian declines.

  6. Global pollinator declines: trends, impacts and drivers.

    Potts, Simon G; Biesmeijer, Jacobus C; Kremen, Claire; Neumann, Peter; Schweiger, Oliver; Kunin, William E


    Pollinators are a key component of global biodiversity, providing vital ecosystem services to crops and wild plants. There is clear evidence of recent declines in both wild and domesticated pollinators, and parallel declines in the plants that rely upon them. Here we describe the nature and extent of reported declines, and review the potential drivers of pollinator loss, including habitat loss and fragmentation, agrochemicals, pathogens, alien species, climate change and the interactions between them. Pollinator declines can result in loss of pollination services which have important negative ecological and economic impacts that could significantly affect the maintenance of wild plant diversity, wider ecosystem stability, crop production, food security and human welfare. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  7. The global financial crisis and neighborhood decline

    Zwiers, M.D.; Bolt, G.; Van Ham, M.; Van Kempen, R.


    Neighborhood decline is a complex and multidimensional process. National and regional variations in economic and political structures (including varieties in national welfare state arrangements), combined with differences in neighborhood history, development, and population composition, make it impo

  8. The Sherpa Maximum Likelihood Estimator

    Nguyen, D.; Doe, S.; Evans, I.; Hain, R.; Primini, F.


    A primary goal for the second release of the Chandra Source Catalog (CSC) is to include X-ray sources with as few as 5 photon counts detected in stacked observations of the same field, while maintaining acceptable detection efficiency and false source rates. Aggressive source detection methods will result in detection of many false positive source candidates. Candidate detections will then be sent to a new tool, the Maximum Likelihood Estimator (MLE), to evaluate the likelihood that a detection is a real source. MLE uses the Sherpa modeling and fitting engine to fit a model of a background and source to multiple overlapping candidate source regions. A background model is calculated by simultaneously fitting the observed photon flux in multiple background regions. This model is used to determine the quality of the fit statistic for a background-only hypothesis in the potential source region. The statistic for a background-plus-source hypothesis is calculated by adding a Gaussian source model convolved with the appropriate Chandra point spread function (PSF) and simultaneously fitting the observed photon flux in each observation in the stack. Since a candidate source may be located anywhere in the field of view of each stacked observation, a different PSF must be used for each observation because of the strong spatial dependence of the Chandra PSF. The likelihood of a valid source being detected is a function of the two statistics (for background alone, and for background-plus-source). The MLE tool is an extensible Python module with potential for use by the general Chandra user.

  9. Vestige: Maximum likelihood phylogenetic footprinting

    Maxwell Peter


    Full Text Available Abstract Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational

  10. Problems Associated with Declining National Oil Production

    Jackson, J. S.


    Forecasts of peak oil production have focussed on the global impacts of declining production. Meanwhile, national oil production has declined in 20 countries, leading to local problems that receive little comment outside of the effected regions. Two problems deserve wider recognition: declining state revenues and fuel substitution. Most oil producing countries with large reserves adopted licensing practices that provide significant revenues to the host governments such that oil revenues generate from 40 to 80 percent of total government funds. Typically these governments allocate a fraction of this revenue to their state oil companies, utilizing the remainder for other activities. As oil revenues decline with falling production, host governments face a dilemma: either to increase state oil company budgets in order to stem the decline, or to starve the state oil company while maintaining other government programs. The declining oil revenues in these states can significantly reduce the government's ability to address important national issues. Mexico, Indonesia, and Yemen illustrate this situation in its early phases. Fuel substitution occurs whenever one fuel proves less expensive than another. The substitution of coal for wood in the eighteenth century and oil for coal in the twentieth century are classic examples. China and India appear to be at peak oil production, while their economies generate increasing demand for energy. Both countries are substituting coal and natural gas for oil with attendant environmental impacts. Coal-to-liquids projects are proposed in in both China, which will require significant water resources if they are executed. These examples suggest that forecasting the impact of peak oil at a regional level requires more than an assessment of proven-probable-possible reserves and a forecast of supply-demand scenarios. A range of government responses to declining oil income scenarios must also be considered, together with scenarios describing

  11. Are infant mortality rate declines exponential? The general pattern of 20th century infant mortality rate decline

    Opuni Marjorie


    Full Text Available Abstract Background Time trends in infant mortality for the 20th century show a curvilinear pattern that most demographers have assumed to be approximately exponential. Virtually all cross-country comparisons and time series analyses of infant mortality have studied the logarithm of infant mortality to account for the curvilinear time trend. However, there is no evidence that the log transform is the best fit for infant mortality time trends. Methods We use maximum likelihood methods to determine the best transformation to fit time trends in infant mortality reduction in the 20th century and to assess the importance of the proper transformation in identifying the relationship between infant mortality and gross domestic product (GDP per capita. We apply the Box Cox transform to infant mortality rate (IMR time series from 18 countries to identify the best fitting value of lambda for each country and for the pooled sample. For each country, we test the value of λ against the null that λ = 0 (logarithmic model and against the null that λ = 1 (linear model. We then demonstrate the importance of selecting the proper transformation by comparing regressions of ln(IMR on same year GDP per capita against Box Cox transformed models. Results Based on chi-squared test statistics, infant mortality decline is best described as an exponential decline only for the United States. For the remaining 17 countries we study, IMR decline is neither best modelled as logarithmic nor as a linear process. Imposing a logarithmic transform on IMR can lead to bias in fitting the relationship between IMR and GDP per capita. Conclusion The assumption that IMR declines are exponential is enshrined in the Preston curve and in nearly all cross-country as well as time series analyses of IMR data since Preston's 1975 paper, but this assumption is seldom correct. Statistical analyses of IMR trends should assess the robustness of findings to transformations other than the log

  12. A maximum in the strength of nanocrystalline copper

    Schiøtz, Jakob; Jacobsen, Karsten Wedel


    We used molecular dynamics simulations with system sizes up to 100 million atoms to simulate plastic deformation of nanocrystalline copper. By varying the grain size between 5 and 50 nanometers, we show that the flow stress and thus the strength exhibit a maximum at a grain size of 10 to 15...... nanometers. This maximum is because of a shift in the microscopic deformation mechanism from dislocation-mediated plasticity in the coarse-grained material to grain boundary sliding in the nanocrystalline region. The simulations allow us to observe the mechanisms behind the grain-size dependence...

  13. Population Dynamics Following the Last Glacial Maximum in Two Sympatric Lizards in Northern China

    Yanfu QU; Qun ZHAO; Hongliang LU; Xiang JI


    Phylogeographic studies ofEremias lizards (Lacertidae) in East Asia have been limited, and the impact of major climatic events on their population dynamics remains poorly known. This study aimed to investigate population histories and refugia during the Last Glacial Maximum of two sympatricEremias lizards (E. argus andE. brenchleyi) inhabiting northern China. We sequenced partial mitochondrial DNA from theND4 gene for 128 individuals ofE. argus from nine localities, and 46 individuals ofE. brenchleyi from ifve localities. Forty-fourND4 haplotypes were determined fromE. argus samples, and 33 fromE. brenchleyi samples. Population expansion events began about 0.0044 Ma inE. argus, and 0.031 Ma inE. brenchleyi. The demographic history ofE. brenchleyi indicates a long-lasting population decline since the most recent common ancestor, while that ofE. argusindicates a continuous population growth. Among-population structure was signiifcant in both species, and there were multiple refugia across their range. Intermittent gene flow occurred among expanded populations across multiple refugia during warmer phases of the glacial period, and this may explain why the effective population size has remained relatively stable inE. brenchleyi and grown inE. argus.

  14. Periodontitis and Cognitive Decline in Alzheimer's Disease.

    Ide, Mark; Harris, Marina; Stevens, Annette; Sussams, Rebecca; Hopkins, Viv; Culliford, David; Fuller, James; Ibbett, Paul; Raybould, Rachel; Thomas, Rhodri; Puenter, Ursula; Teeling, Jessica; Perry, V Hugh; Holmes, Clive


    Periodontitis is common in the elderly and may become more common in Alzheimer's disease because of a reduced ability to take care of oral hygiene as the disease progresses. Elevated antibodies to periodontal bacteria are associated with an increased systemic pro-inflammatory state. Elsewhere raised serum pro-inflammatory cytokines have been associated with an increased rate of cognitive decline in Alzheimer's disease. We hypothesized that periodontitis would be associated with increased dementia severity and a more rapid cognitive decline in Alzheimer's disease. We aimed to determine if periodontitis in Alzheimer's disease is associated with both increased dementia severity and cognitive decline, and an increased systemic pro inflammatory state. In a six month observational cohort study 60 community dwelling participants with mild to moderate Alzheimer's Disease were cognitively assessed and a blood sample taken for systemic inflammatory markers. Dental health was assessed by a dental hygienist, blind to cognitive outcomes. All assessments were repeated at six months. The presence of periodontitis at baseline was not related to baseline cognitive state but was associated with a six fold increase in the rate of cognitive decline as assessed by the ADAS-cog over a six month follow up period. Periodontitis at baseline was associated with a relative increase in the pro-inflammatory state over the six month follow up period. Our data showed that periodontitis is associated with an increase in cognitive decline in Alzheimer's Disease, independent to baseline cognitive state, which may be mediated through effects on systemic inflammation.

  15. Periodontitis and Cognitive Decline in Alzheimer's Disease.

    Mark Ide

    Full Text Available Periodontitis is common in the elderly and may become more common in Alzheimer's disease because of a reduced ability to take care of oral hygiene as the disease progresses. Elevated antibodies to periodontal bacteria are associated with an increased systemic pro-inflammatory state. Elsewhere raised serum pro-inflammatory cytokines have been associated with an increased rate of cognitive decline in Alzheimer's disease. We hypothesized that periodontitis would be associated with increased dementia severity and a more rapid cognitive decline in Alzheimer's disease. We aimed to determine if periodontitis in Alzheimer's disease is associated with both increased dementia severity and cognitive decline, and an increased systemic pro inflammatory state. In a six month observational cohort study 60 community dwelling participants with mild to moderate Alzheimer's Disease were cognitively assessed and a blood sample taken for systemic inflammatory markers. Dental health was assessed by a dental hygienist, blind to cognitive outcomes. All assessments were repeated at six months. The presence of periodontitis at baseline was not related to baseline cognitive state but was associated with a six fold increase in the rate of cognitive decline as assessed by the ADAS-cog over a six month follow up period. Periodontitis at baseline was associated with a relative increase in the pro-inflammatory state over the six month follow up period. Our data showed that periodontitis is associated with an increase in cognitive decline in Alzheimer's Disease, independent to baseline cognitive state, which may be mediated through effects on systemic inflammation.

  16. Evaluating Maximum Wind Energy Exploitation in Active Distribution Networks

    Siano, Pierluigi; Chen, Peiyuan; Chen, Zhe;


    The increased spreading of distributed and renewable generation requires moving towards active management of distribution networks. In this paper, in order to evaluate maximum wind energy exploitation in active distribution networks, a method based on a multi-period optimal power flow (OPF) analy...... distribution system, confirmed the effectiveness of the proposed method in evaluating the optimal applications of active management schemes to increase wind energy harvesting without costly network reinforcement for the connection of wind generation.......The increased spreading of distributed and renewable generation requires moving towards active management of distribution networks. In this paper, in order to evaluate maximum wind energy exploitation in active distribution networks, a method based on a multi-period optimal power flow (OPF...

  17. Life-history traits and population decline of the Atlantic mackerel Scomber scombrusin the Adriatic Sea.

    Meneghesso, C; Riginella, E; La Mesa, M; Donato, F; Mazzoldi, C


    This study investigated demographic structure and reproductive characteristics of the Atlantic mackerel Scomber scombrus, in relation to landing trends in the northern-central Adriatic Sea. Results highlighted the occurrence of only small-sized and young-age individuals, and a marked decline from the 1990s to the present in maximum age (from 8 to 3 years) and total length (L(T); from 420 to 360 mm). Fecundity ranged between 40,000 and 190,000 eggs, and was related to female L(T). High levels of atresia implied lower values of actual fecundity. Sexual maturity was attained by 72·8% of individuals in their first year of life at 200 mm. The reduction in maximum L(T) resulted in a marked decline in the population egg production, while the reduction in maximum age implied that females participated in fewer spawning events.

  18. Biomarkers of cognitive decline in Parkinson's disease.

    Lin, Chin-Hsien; Wu, Ruey-Meei


    Cognitive impairment is a frequent and devastating non-motor symptom of Parkinson's disease (PD). Impaired cognition has a major impact on either quality of life or mortality in patients with PD. Notably, the rate of cognitive decline and pattern of early cognitive deficits in PD are highly variable between individuals. Given that the underlying mechanisms of cognitive decline or dementia associated with PD remain unclear, there is currently no mechanism-based treatment available. Identification of biological markers, including neuroimaging, biofluids and common genetic variants, that account for the heterogeneity of PD related cognitive decline could provide important insights into the pathological processes that underlie cognitive impairment in PD. These combined biomarker approaches will enable early diagnosis and provide indicators of cognitive progression in PD patients. This review summarizes recent advances in the development of biomarkers for cognitive impairments in PD.

  19. Approximate maximum-entropy moment closures for gas dynamics

    McDonald, James G.


    Accurate prediction of flows that exist between the traditional continuum regime and the free-molecular regime have proven difficult to obtain. Current methods are either inaccurate in this regime or prohibitively expensive for practical problems. Moment closures have long held the promise of providing new, affordable, accurate methods in this regime. The maximum-entropy hierarchy of closures seems to offer particularly attractive physical and mathematical properties. Unfortunately, several difficulties render the practical implementation of maximum-entropy closures very difficult. This work examines the use of simple approximations to these maximum-entropy closures and shows that physical accuracy that is vastly improved over continuum methods can be obtained without a significant increase in computational cost. Initially the technique is demonstrated for a simple one-dimensional gas. It is then extended to the full three-dimensional setting. The resulting moment equations are used for the numerical solution of shock-wave profiles with promising results.

  20. Mind the bubbles: achieving stable measurements of maximum hydraulic conductivity through woody plant samples.

    Espino, Susana; Schenk, H Jochen


    The maximum specific hydraulic conductivity (k(max)) of a plant sample is a measure of the ability of a plants' vascular system to transport water and dissolved nutrients under optimum conditions. Precise measurements of k(max) are needed in comparative studies of hydraulic conductivity, as well as for measuring the formation and repair of xylem embolisms. Unstable measurements of k(max) are a common problem when measuring woody plant samples and it is commonly observed that k(max) declines from initially high values, especially when positive water pressure is used to flush out embolisms. This study was designed to test five hypotheses that could potentially explain declines in k(max) under positive pressure: (i) non-steady-state flow; (ii) swelling of pectin hydrogels in inter-vessel pit membranes; (iii) nucleation and coalescence of bubbles at constrictions in the xylem; (iv) physiological wounding responses; and (v) passive wounding responses, such as clogging of the xylem by debris. Prehydrated woody stems from Laurus nobilis (Lauraceae) and Encelia farinosa (Asteraceae) collected from plants grown in the Fullerton Arboretum in Southern California, were used to test these hypotheses using a xylem embolism meter (XYL'EM). Treatments included simultaneous measurements of stem inflow and outflow, enzyme inhibitors, stem-debarking, low water temperatures, different water degassing techniques, and varied concentrations of calcium, potassium, magnesium, and copper salts in aqueous measurement solutions. Stable measurements of k(max) were observed at concentrations of calcium, potassium, and magnesium salts high enough to suppress bubble coalescence, as well as with deionized water that was degassed using a membrane contactor under strong vacuum. Bubble formation and coalescence under positive pressure in the xylem therefore appear to be the main cause for declining k(max) values. Our findings suggest that degassing of water is essential for achieving stable and

  1. Identifying functional decline: a methodological challenge

    Grimmer K


    Full Text Available Karen Grimmer, Kate Beaton, Kevan Hendry International Centre for Allied Health Evidence, University of South Australia, Adelaide, SA, Australia Background: Functional decline (FD in older people has commonly been measured in the hospital setting with instruments which have been validated on decrease over time in capacity to undertake basic activities of daily living (ADL. In a nonhospitalized sample of older people (independently community dwelling, but potentially on the cusp of FD, it is possible that other measures could be used to predict decline. Early, accurate, and efficient identification of older community-dwelling people who are on the cusp of FD can assist in identifying appropriate interventions to slow the rate of decline. Methods: This paper reports on associations between four outcome measures which have been associated with FD (instrumental ADLs [IADLs], quality of life, hospitalizations and falls. The sample was older individuals who were discharged from one large metropolitan emergency department (ED during 2011–2012, without an inpatient admission. Results: Of 597 individuals aged 65+ who provided baseline information, 148 subjects provided four outcome measures at both 1 and 3 months follow up. Overall, approximately 24% demonstrated decreased IADL scores over the 3 months, with domains of home activities, laundry, shopping, and getting places declining the most. Over this time, 18% fell often, and 11% were consistently hospitalized. Between 1 and 3 months follow up, 41% declined in mental component scores, and 50% declined in physical component scores. Low mental and physical component quality of life scores were associated with downstream increased falls and hospitalizations, and decreased quality of life and IADLs. However, change in the four outcome measures was largely independent in factor analysis. Conclusion: Measuring the four outcome measures over 3 months post-discharge from an ED presentation, showed that

  2. Receiver function estimated by maximum entropy deconvolution

    吴庆举; 田小波; 张乃铃; 李卫平; 曾融生


    Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.

  3. Maximum Power from a Solar Panel

    Michael Miller


    Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

  4. Phylogenetic escalation and decline of plant defense strategies.

    Agrawal, Anurag A; Fishbein, Mark


    As the basal resource in most food webs, plants have evolved myriad strategies to battle consumption by herbivores. Over the past 50 years, plant defense theories have been formulated to explain the remarkable variation in abundance, distribution, and diversity of secondary chemistry and other defensive traits. For example, classic theories of enemy-driven evolutionary dynamics have hypothesized that defensive traits escalate through the diversification process. Despite the fact that macroevolutionary patterns are an explicit part of defense theories, phylogenetic analyses have not been previously attempted to disentangle specific predictions concerning (i) investment in resistance traits, (ii) recovery after damage, and (iii) plant growth rate. We constructed a molecular phylogeny of 38 species of milkweed and tested four major predictions of defense theory using maximum-likelihood methods. We did not find support for the growth-rate hypothesis. Our key finding was a pattern of phyletic decline in the three most potent resistance traits (cardenolides, latex, and trichomes) and an escalation of regrowth ability. Our neontological approach complements more common paleontological approaches to discover directional trends in the evolution of life and points to the importance of natural enemies in the macroevolution of species. The finding of macroevolutionary escalating regowth ability and declining resistance provides a window into the ongoing coevolutionary dynamics between plants and herbivores and suggests a revision of classic plant defense theory. Where plants are primarily consumed by specialist herbivores, regrowth (or tolerance) may be favored over resistance traits during the diversification process.

  5. Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha

    Farrell, A P; Steffensen, J F


    The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...... a statistically significant 35.5% reduction in maximum swimming speed. We conclude that the coronary circulation is important for maximum aerobic swimming and implicit in this conclusion is that maximum cardiac performance is probably necessary for maximum aerobic swimming performance....

  6. Political Factors in Public School Decline.

    Peltzman, Sam


    Teacher unionization, centralization of financial control, desegregation, and weakening in business involvement are among the political factors that have contributed to the decline in public school performance between 1965 and 1980. Research into these factors confirms the importance of political influences on schooling and suggests that…

  7. Why Do Patients with COPD Decline Rehabilitation

    Mathar, Helle; Fastholm, Pernille; Hansen, Ida Rode


    AIM: This paper aimed to suggest possible answers to the question: Why do patients with COPD decline pulmonary rehabilitation (PR)? METHOD: The study is a metasynthesis inspired by Noblit of the existing qualitative research on the area. The data were collected during 2014. Six studies were found...

  8. Afterword: The Management and Consequences of Decline.

    Boyd, William Lowe


    Stresses the need for aggressive, farsighted management of decline and for more Federal and State aid to local school administrators to combat the negative effects of school closures and retrenchment, and to ensure that retrenched school systems still serve children effectively. (Author/MJL)

  9. The Decline of Literature: A Public Perspective

    Albalawi, Mohammed


    After centuries of dominance, literature has not been in a robust health for the last few decades. Several scholars have addressed the decline of literature in a number of books and articles attributing it to institutional and economic reasons. However, a major factor has not been taken into account. It is the larger audience who receives and…

  10. Prevalence of Hunger Declines in Rural Households.

    Nord, Mark; Winicki, F. Joshua


    The prevalence of hunger in rural households declined slightly from 1995 to 1998, and food insecurity rates stayed constant. Food insecurity was almost three times as prevalent among rural Blacks as among rural Whites. For rural Hispanics, the rate was about twice that of Whites. Food insecurity was higher in single-parent families than in any…

  11. NIDI scenario. Strong population decline in China

    de Beer, J.A.A.


    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario

  12. Student Writing: Strategies to Reverse Ongoing Decline

    Carter, Michael J.; Harper, Heather


    This article reports on the decline in writing ability skills in secondary and higher education students. The author discusses changes that have affected student writing skills over the recent decades and offers recommendations for improving these skills, such as: implementing intensive freshman writing courses; adjusting existing course…

  13. The Decline in China Textile Exports Narrowed


    This is a crucial moment for China’s textile export industry, which is in the midst of deep economic downturn. In the January-Novem- ber 2009 period, the decline in accumulated textile and apparel exports was being constantly reduced and the tendency of rebound is

  14. Episodic memory decline and healthy aging

    Wang, W.C.; Daselaar, S.M.; Cabeza, R.


    One of the cognitive functions most affected by the aging process is our memory for personally experienced past events or episodic memory (EM). The advent of functional neuroimaging has greatly advanced our knowledge of the neural basis of EM and its decline with age. The current chapter revi

  15. Exploring the Global Decline of Music Education

    Aróstegui, José Luis


    This article seeks to explain the disjuncture between the decline of music education in schools and the importance music has in popular youth culture and in creativity within the new knowledge economy. The data discussed in this article have been derived from analyses of major documents on curriculum reform as well as e-mail responses from music…

  16. Why Employee Motivation Has Declined in America.

    Grant, Philip C.


    Examines possible reasons for declining employee motivation: greater instability and diversity of values; more guaranteed rewards; inability of rewards to satisfy emerging needs; disappearing work ethic; reduced costs of failure; rising income and progressive taxation; more group production and problem solving; decreased employee loyalty; less…

  17. Cholesterol and late-life cognitive decline.

    van Vliet, Peter


    High cholesterol levels are a major risk factor for cardiovascular disease, but their role in dementia and cognitive decline is less clear. This review highlights current knowledge on the role of cholesterol in late-life cognitive function, cognitive decline, and dementia. When measured in midlife, high cholesterol levels associate with an increased risk of late-life dementia and cognitive decline. However, when measured in late-life, high cholesterol levels show no association with cognitive function, or even show an inverse relation. Although statin treatment has been shown to associate with a lower risk of dementia and cognitive decline in observational studies, randomized controlled trials show no beneficial effect of statin treatment on late-life cognitive function. Lowering cholesterol levels may impair brain function, since cholesterol is essential for synapse formation and maturation and plays an important role in the regulation of signal transduction through its function as a component of the cell membrane. However, membrane cholesterol also plays a role in the formation and aggregation of amyloid-β. Factors that influence cholesterol metabolism, such as dietary intake, are shown to play a role in late-life cognitive function and the risk of dementia. In conclusion, cholesterol associates with late-life cognitive function, but the association is strongly age-dependent. There is no evidence that treatment with statins in late-life has a beneficial effect on cognitive function.

  18. Migratory diversity predicts population declines in birds.

    Gilroy, James J; Gill, Jennifer A; Butchart, Stuart H M; Jones, Victoria R; Franco, Aldina M A


    Declines in migratory species are a pressing concern worldwide, but the mechanisms underpinning these declines are not fully understood. We hypothesised that species with greater within-population variability in migratory movements and destinations, here termed 'migratory diversity', might be more resilient to environmental change. To test this, we related map-based metrics of migratory diversity to recent population trends for 340 European breeding birds. Species that occupy larger non-breeding ranges relative to breeding, a characteristic we term 'migratory dispersion', were less likely to be declining than those with more restricted non-breeding ranges. Species with partial migration strategies (i.e. overlapping breeding and non-breeding ranges) were also less likely to be declining than full migrants or full residents, an effect that was independent of migration distance. Recent rates of advancement in Europe-wide spring arrival date were greater for partial migrants than full migrants, suggesting that migratory diversity may also help facilitate species responses to climate change. © 2016 John Wiley & Sons Ltd/CNRS.

  19. The Decline of Direct Newspaper Competition.

    Rosse, James N.


    Describes the decline of direct newspaper competition in terms of the loss of effective newspaper market segmentation. Examines the following influences on market segmentation: shift in advertising demand, advertiser preferences for differentiated audiences, shift in subscriber demand, growth of alternative media, increasing production costs, and…

  20. [Forest degradation/decline: research and practice].

    Zhu, Jiao-Jun; Li, Feng-Qin


    As one of the most critical environmental problems in the 21st century, forest degradation has been facing worldwide. There are many definitions about forest degradation, but its common features are the permanent loss of forests, stand structure destructed, forest quality decreased, and forest functions lowered. Forest decline or tree decline in fact is one of the causes of forest degradation, which includes the general reduction of trees in vigor, low level growth of trees in productivity, death of trees, and even, decline of soil fertility. Many researches indicated that deforestation is the permanent loss of forests in area, which is shifted to other land uses. Deforestation is the product of the interactions between environmental, social, economic, cultural, and political forces at work in any given country/region, and thus, more and more attention is focused on the negative socioeconomic and environmental effects after forest degradation, especially on the reduction of forest area induced by deforestation. The effects of any decisions or policies in national and international levels on forest degradation induced by deforestation have been paid attention as well. How to make efforts and strengthen the worldwide cooperation to combat the forest degradation induced by deforestation must be challenged to find appropriate solutions. There are many researches on forest decline, because of its complexity and uncertainties. The major causes of forest decline include: 1) pollution from both industry and agriculture, 2) stress factors, e.g., desiccation, 3) changes in stand dynamics, 4) decline disease of forest or diseases of complex etiology, 5) degradation of productivity and/or soil fertility in pure plantation forests. Forest degradation in China is similar to that all over the world, but with the characteristics in forest components, i.e., 1) secondary forests are the major forest resources, 2) China has the most plantation forests in the world, some of which have

  1. Maximum permissible voltage of YBCO coated conductors

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)


    Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  2. Metabolic Syndrome and 16-year Cognitive Decline in Community-Dwelling Older Adults

    McEvoy, Linda K.; Laughlin, Gail A.; Barrett-Connor, Elizabeth; Bergstrom, Jaclyn; Kritz-Silverstein, Donna; Der-Martirosian, Claudia; von Mühlen, Denise


    PURPOSE To determine whether metabolic syndrome is associated with accelerated cognitive decline in community-dwelling older adults. METHODS Longitudinal study of 993 adults (mean 66.8 ± 8.7 years) from the Rancho Bernardo Study. Metabolic syndrome components, defined by 2001 NCEP-ATP III criteria, were measured in 1984–87. Cognitive function was first assessed in 1988–92. Cognitive assessments were repeated approximately every four years, for a maximum 16-year follow-up. Mixed-effects models examined longitudinal rate of cognitive decline by metabolic syndrome status, controlling for factors plausibly associated with cognitive function (diabetes, inflammation). RESULTS Metabolic syndrome was more common in men than women (14% vs. 9%, p=0.01). In women, metabolic syndrome was associated with greater executive function and long term memory decline. These associations did not differ by inflammatory biomarker levels. Diabetes did not alter the association of metabolic syndrome with long-term recall but modified the association with executive function: metabolic syndrome was associated with accelerated executive function decline in diabetic women only. Metabolic syndrome was not related to rate of decline on any cognitive measure in men. CONCLUSIONS Metabolic syndrome was a risk factor for accelerated cognitive decline, but only in women. Prevention of metabolic syndrome may aid in maintenance of cognitive function with age. PMID:22285865

  3. Neuromuscular determinants of maximum walking speed in well-functioning older adults.

    Clark, David J; Manini, Todd M; Fielding, Roger A; Patten, Carolynn


    Maximum walking speed may offer an advantage over usual walking speed for clinical assessment of age-related declines in mobility function that are due to neuromuscular impairment. The objective of this study was to determine the extent to which maximum walking speed is affected by neuromuscular function of the lower extremities in older adults. We recruited two groups of healthy, well functioning older adults who differed primarily on maximum walking speed. We hypothesized that individuals with slower maximum walking speed would exhibit reduced lower extremity muscle size and impaired plantarflexion force production and neuromuscular activation during a rapid contraction of the triceps surae muscle group (soleus (SO) and gastrocnemius (MG)). All participants were required to have usual 10-meter walking speed of >1.0m/s. If the difference between usual and maximum 10m walking speed was 0.6m/s, the individual was assigned to the "Faster" group (n=12). Peak rate of force development (RFD) and rate of neuromuscular activation (rate of EMG rise) of the triceps surae muscle group were assessed during a rapid plantarflexion movement. Muscle cross sectional area of the right triceps surae, quadriceps and hamstrings muscle groups was determined by magnetic resonance imaging. Across participants, the difference between usual and maximal walking speed was predominantly dictated by maximum walking speed (r=.85). We therefore report maximum walking speed (1.76 and 2.17m/s in Slower and Faster, ptriceps surae (p=.44), quadriceps (p=.76) and hamstrings (p=.98). MG rate of EMG rise was positively associated with RFD and maximum 10m walking speed, but not the usual 10m walking speed. These findings support the conclusion that maximum walking speed is limited by impaired neuromuscular force and activation of the triceps surae muscle group. Future research should further evaluate the utility of maximum walking speed for use in clinical assessment to detect and monitor age

  4. Inferring species decline from collection records

    Carpaneto, Giuseppe Maria; Mazziotta, Adriano; Valerio, Laura


    The decline of roller dung beetles (Coleoptera, Scarabaeidae) in Italy, at national and regional level, was described using a database of both literature and unpublished data, since the late of 19th century. The probability of finding roller species was assessed for each decade of the 20th century...... UTM cells dropped by 23%. Six roller species showed a significant decline in Italy from the first to the second part of the 20th century, and nine in the last 30years. Other two species disappeared from the majority of the northern regions. Finally, the values of all the extinction indexes were...... strongly correlated and detected a high risk of extinction in Italy for six species. A gradual change in land use during the last three decades, consisting of a reduced extension of grasslands in favour of either intensive agriculture or reforestation after abandonment of livestock raising, was likely...

  5. The Rise and Decline of Japanese Pacifism

    Yuan Cai


    Full Text Available The Japanese pacifist constitution has been a symbol of Japan’s commitment to peace and more importantly its renunciation of wartime militarism. There has been strong support for its continuing existence amongst the Japanese populace despite persistent attempts by the Japanese government to amend it. However, the prevalent pacifist sentiment is showing signs of fading vitality in recent times. This article purports to examine the underlying forces that contributed to the development and the decline of Japanese pacifism. A host of domestic and international factors were responsible for the growth of pacifism and its subsequent decline, but only three important domestic factors will be examined in detail: the concept of victimhood in the development of pacifism and its implication for its continuing strength, the importance of peace education and the role played by the influential Japan’s Teachers’ Union on the formation of pacifist conscience and finally, the influence of leftist organisations on the organised peace movement.

  6. Inferring species decline from collection records

    Carpaneto, Giuseppe Maria; Mazziotta, Adriano; Valerio, Laura


    increased clearly as a consequence of the escalation of entomological surveys. Nevertheless, comparing R species (rollers) with all the scarab dung beetles from the first to the last quarter of the 20th century, the relative frequency of roller records decreased by 31%, while the relative number of occupied......The decline of roller dung beetles (Coleoptera, Scarabaeidae) in Italy, at national and regional level, was described using a database of both literature and unpublished data, since the late of 19th century. The probability of finding roller species was assessed for each decade of the 20th century...... UTM cells dropped by 23%. Six roller species showed a significant decline in Italy from the first to the second part of the 20th century, and nine in the last 30years. Other two species disappeared from the majority of the northern regions. Finally, the values of all the extinction indexes were...

  7. Functional and cognitive decline in hospitalized elderly



    Full Text Available ABSTRACT Aim – Understand if functional and cognitive decline is accentuated during hospitalization in elderly patients. Method – It was design a descriptive and correlational study. The Functional Independence Measure (FIM and the Mini-Mental State Examination (MMSE were used. Results – Were evaluated at admission and discharge 51 elderly (75.53 ± 7.16 years, 53% women, admitted in an internal medicine unit with a length of stay of 14.27±6.45 days. For FIM and MMSE were found statistically significant differences with lower scores from admission to discharge. Negative correlations between age and length of stay and the scores of all measures were found. Except for the Cognitive FIM at admission, all elderly residents at home fared better than the institutionalized in all measures. Conclusions – The hospitalization contributes to a greater weakness/frailty of the elderly and is considered high risk for decline in physical fitness and cognitive function.

  8. The rise (and decline?) of biotechnology.

    Kinch, Michael S


    Since the 1970s, biotechnology has been a key innovator in drug development. An analysis of FDA-approved therapeutics demonstrates pharmaceutical companies outpace biotechs in terms of new approvals but biotechnology companies are now responsible for earlier-stage activities (patents, INDs or clinical development). The number of biotechnology organizations that contributed to an FDA approval began declining in the 2000s and is at a level not seen since the 1980s. Whereas early biotechnology companies had a decade from first approval until acquisition, the average acquisition of a biotechnology company now occurs months before their first FDA approval. The number of hybrid organizations that arise when pharmaceutical companies acquire biotechnology is likewise declining, raising questions about the sustainability of biotechnology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Analysis of production decline in geothermal reservoirs

    Zais, Elliot J.; Bodvarsson, Gunnar


    The major objectives of the Decline Curve project were to: (1) test the decline analysis methods used in the petroleum industry on geothermal production data; (2) examine and/or develop new analysis methods; and (3) develop a standard operating procedure for analyzing geothermal production data. Various analysis methods have long been available but they have not been tested on geothermal data because of the lack of publicly available data. The recent release to publication of substantial data sets from Wairakei, New Zealand, Cerro Prieto, Mexico and The Geysers, USA has made this study possible. Geothermal reservoirs are quite different from petroleum reservoirs in many ways so the analysis methods must be tested using geothermal data.

  10. Lithuania: Fertility decline and its determinants

    Aiva Jasilioniene


    Full Text Available Since the beginning of the 1990s, Lithuania has been undergoing significant transformations in family life and has experienced a precipitous decline in fertility. The determinants of the changes are diverse in character and are associated with socioeconomic transformations, economic difficulties faced by the post-Soviet society, inadequate social and family policies and changing value orientations and life styles. This article traces the fertility trends in Lithuania from the period and cohort perspective, providing adjusted TFR estimates that reveal the significance of the tempo effect on the recent decline in fertility. Furthermore, the main factors leading to the recently observed changes in family and fertility are identified and analysed. Finally, the characteristic features and necessary improvements of current Lithuanian family policy and its possible effects on individual behaviour and fertility trends are discussed.

  11. Dehydroepiandrosterone and age-related cognitive decline

    Sorwell, Krystina G.; Urbanski, Henryk F.


    In humans the circulating concentrations of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) decrease markedly during aging, and have been implicated in age-associated cognitive decline. This has led to the hypothesis that DHEA supplementation during aging may improve memory. In rodents, a cognitive anti-aging effect of DHEA and DHEAS has been observed but it is unclear whether this effect is mediated indirectly through conversion of these steroids to estradiol. Moreover, despite the de...

  12. MIND diet slows cognitive decline with aging

    Morris, Martha Clare; Tangney, Christy C.; Wang, Yamin; Sacks, Frank Martin; Barnes, Lisa L.; Bennett, David William; Aggarwal, Neelum T


    INTRODUCTION: The Mediterranean and dash diets have been shown to slow cognitive decline; however, neither diet is specific to the nutrition literature on dementia prevention. METHODS: We devised the Mediterranean-Dietary Approach to Systolic Hypertension (DASH) diet intervention for neurodegenerative delay (MIND) diet score that specifically captures dietary components shown to be neuroprotective and related it to change in cognition over an average 4.7 years among 960 participants ...

  13. The Decline of Air Assault Operations


    criticality of mission focus to the success of air assaults . However, 31 1st Infantry Division, AAR—Operation Junction City for 22 February 1967 to 15...product life cycle theory is a great way to visualize the fifty-year life of air assault operations; however, its explanatory powers are limited. The 1962...The Decline of Air Assault Operations A Monograph by MAJ Jason S. Raub United States Army School of

  14. Instantaneous Flow Structures and Opportunities for Larval Settlement: Barnacle Larvae Swim to Settle.

    Ann I Larsson

    Full Text Available Water flow affects settlement of marine larvae on several scales. At the smallest scale local flow regime may control the probability of adhesion to the substrate. Our aim was to mechanistically understand the transition from suspended to attached larvae in turbulent flow. Recently it was proposed that opportunities for larval settlement in turbulent boundary layers depend on time windows with suitable instantaneous flow properties. In flume flow we characterized the proportion of suitable time windows in a series of flow velocities with focus on the near-bed flow. The change in the proportion of potential settling windows with increasing free-stream velocities was compared to the proportion of temporary attachment of barnacle cypris larvae at different flow velocities. We found large instantaneous flow variations in the near-bed flow where cyprid attachment took place. The probability of temporary attachment in cyprids declined with local flow speed and this response was compatible with a settling window lasting at least 0.1 s with a maximum local flow speed of 1.9-2.4 cm s-1. Cyprids swam against the near-bed flow (negative rheotaxis and the swimming speed (1.8 cm s-1 was close to the critical speed that permitted temporary attachment. We conclude that temporary attachment in barnacle cyprids requires upstream swimming to maintain a fixed position relative to the substrate for at least 0.1 s. This behaviour may explain the ability of barnacles to recruit to high-flow environments and give cyprids flexibility in the pre-settlement choice of substrates based on flow regime.

  15. Family planning programs and fertility decline.

    Cuca, R


    A recently completed World Bank statistical study of family planning in 63 developing countries indicated that countries which experienced a large decline in birth rates between 1960-1977 were more likely to have a family planning program, an official population policy aimed at decreasing the birth rate, and a relatively high level of development than countries which experienced smaller or no decline in birth rates. The 65 countries represented 95% of the population of the developing world. Birth rate declines of 10% or more between 1960-1977 were experienced by: 1) 10 of the 26 countries which had a family planning program and a policy aimed at reducing the birth rate; 2) 6 of the 19 countries which had a family planning program but lacked clearly defined population objectives; and 3) 2 of the 18 countries without any population policy or program. Furthermore, the implementation of a family planning program and the adoption of a population policy were directly related to the development level of the country. This finding suggested that countries need to reach a certain level of development before they have the capacity to develop population programs and policies. When a country is sufficiently advanced to collect population data, awareness of population problems increases and they are more likely to adopt a population policy. In addition, government efficiency increases as development proceeds and governments must have a certain level of efficiency before they can implement effective programs.

  16. Farmer's lung is now in decline.

    Arya, A


    Farmer\\'s lung incidence in Ireland was constant until 1996, even though hay making methods were revolutionised in late 1980\\'s. We undertook this study to find out the incidence of farmer\\'s lung in Ireland from 1982-2002 and its correlation with rainfall and the effect of changing farm practices. The primary cases of farmer\\'s lung were identified from Hospital in Patients Enquiry (HIPE) unit of the national Economic & Social Research Institute (ESRI) Dublin. Rainfall data were obtained from Met Eireann whereas population, hay production and silage production were obtained from the Central Statistics Office, Dublin. As the farming population is in decline, we used the annual working unit (AWU), which reflects the true population at risk. An AWU is the equivalent of 1800 hours per farm worker per year. The incidence rates were constant from 1982-1996, but from 1997-2002 a marked decline was observed. There was strong positive correlation with hay production (r = 0.81) and strong negative correlation with silage production (r = -0.82). This study indicates that the incidence of farmer\\'s lung is now in decline.

  17. Generalised maximum entropy and heterogeneous technologies

    Oude Lansink, A.G.J.M.


    Generalised maximum entropy methods are used to estimate a dual model of production on panel data of Dutch cash crop farms over the period 1970-1992. The generalised maximum entropy approach allows a coherent system of input demand and output supply equations to be estimated for each farm in the sam

  18. 20 CFR 229.48 - Family maximum.


    ... month on one person's earnings record is limited. This limited amount is called the family maximum. The family maximum used to adjust the social security overall minimum rate is based on the employee's Overall..., when any of the persons entitled to benefits on the insured individual's compensation would, except...

  19. The maximum rotation of a galactic disc

    Bottema, R


    The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously

  20. Boundary condition effects on maximum groundwater withdrawal in coastal aquifers.

    Lu, Chunhui; Chen, Yiming; Luo, Jian


    Prevention of sea water intrusion in coastal aquifers subject to groundwater withdrawal requires optimization of well pumping rates to maximize the water supply while avoiding sea water intrusion. Boundary conditions and the aquifer domain size have significant influences on simulating flow and concentration fields and estimating maximum pumping rates. In this study, an analytical solution is derived based on the potential-flow theory for evaluating maximum groundwater pumping rates in a domain with a constant hydraulic head landward boundary. An empirical correction factor, which was introduced by Pool and Carrera (2011) to account for mixing in the case with a constant recharge rate boundary condition, is found also applicable for the case with a constant hydraulic head boundary condition, and therefore greatly improves the usefulness of the sharp-interface analytical solution. Comparing with the solution for a constant recharge rate boundary, we find that a constant hydraulic head boundary often yields larger estimations of the maximum pumping rate and when the domain size is five times greater than the distance between the well and the coastline, the effect of setting different landward boundary conditions becomes insignificant with a relative difference between two solutions less than 2.5%. These findings can serve as a preliminary guidance for conducting numerical simulations and designing tank-scale laboratory experiments for studying groundwater withdrawal problems in coastal aquifers with minimized boundary condition effects.

  1. Duality of Maximum Entropy and Minimum Divergence

    Shinto Eguchi


    Full Text Available We discuss a special class of generalized divergence measures by the use of generator functions. Any divergence measure in the class is separated into the difference between cross and diagonal entropy. The diagonal entropy measure in the class associates with a model of maximum entropy distributions; the divergence measure leads to statistical estimation via minimization, for arbitrarily giving a statistical model. The dualistic relationship between the maximum entropy model and the minimum divergence estimation is explored in the framework of information geometry. The model of maximum entropy distributions is characterized to be totally geodesic with respect to the linear connection associated with the divergence. A natural extension for the classical theory for the maximum likelihood method under the maximum entropy model in terms of the Boltzmann-Gibbs-Shannon entropy is given. We discuss the duality in detail for Tsallis entropy as a typical example.

  2. Climatic Variation and River Flows in Himalayan Basins Upstream of Large Dams

    Eaton, D.; Collins, D. N.


    High specific discharges from Himalayan headwater basins feed major reservoirs generating hydropower and supplying water to irrigation schemes across the Punjab plains of north-west India and Pakistan. Flow arises from seasonal winter snow cover, summer monsoon precipitation and melting glacier ice in varying proportions and differing absolute quantities along west -east axes of the Karakoram and western Himalaya. Discharge records for stations above Tarbela (Indus), Mangla (Jhelum), Marala (Chenab) and Bhakra (Sutlej) dams have been examined for periods between 1920 and 2009, together with precipitation and air temperature data for stations with long records (within the period 1893 to 2013) at elevations between 234 and 3015 m a.s.l. Ice-cover age in the basins above the dams was between 1 and 12 %. Flows in the Sutlej, Chenab and Jhelum reached maxima in the 1950s before declining to the 1970s. Flow in the Chenab and Jhelum increased to 1950s levels in the 1990s, before falling steeply into the 2000s mimicking variations in winter and monsoon precipitation. Discharge in the Indus at Tarbela increased from the 1970s, reaching a maximum in the late 1980s/early 1990s, before declining back to 1970s levels in the 2000s, flow being influenced not only by precipitation fluctuations but also by changes in air temperature affecting glacier melt in headwater basins. Runoff at Bhakra was augmented by flow from the Beas-Sutlej link canal after 1977, but natural flow in the Sutlej above Luhri reduced considerably from the 1990s influenced by declining flows in the relatively dry but large Tibetan portion of the basin area. Large year-to-year fluctuations of reservoir inflows are nonetheless based on significant sustained underlying discharge levels at all four reservoirs.

  3. Estimating the maximum potential revenue for grid connected electricity storage :

    Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.


    The valuation of an electricity storage device is based on the expected future cash flow generated by the device. Two potential sources of income for an electricity storage system are energy arbitrage and participation in the frequency regulation market. Energy arbitrage refers to purchasing (stor- ing) energy when electricity prices are low, and selling (discharging) energy when electricity prices are high. Frequency regulation is an ancillary service geared towards maintaining system frequency, and is typically procured by the independent system operator in some type of market. This paper outlines the calculations required to estimate the maximum potential revenue from participating in these two activities. First, a mathematical model is presented for the state of charge as a function of the storage device parameters and the quantities of electricity purchased/sold as well as the quantities o ered into the regulation market. Using this mathematical model, we present a linear programming optimization approach to calculating the maximum potential revenue from an elec- tricity storage device. The calculation of the maximum potential revenue is critical in developing an upper bound on the value of storage, as a benchmark for evaluating potential trading strate- gies, and a tool for capital nance risk assessment. Then, we use historical California Independent System Operator (CAISO) data from 2010-2011 to evaluate the maximum potential revenue from the Tehachapi wind energy storage project, an American Recovery and Reinvestment Act of 2009 (ARRA) energy storage demonstration project. We investigate the maximum potential revenue from two di erent scenarios: arbitrage only and arbitrage combined with the regulation market. Our analysis shows that participation in the regulation market produces four times the revenue compared to arbitrage in the CAISO market using 2010 and 2011 data. Then we evaluate several trading strategies to illustrate how they compare to the


    Mursula, K.; Holappa, L. [ReSoLVE Centre of Excellence, Department of Physics, University of Oulu (Finland); Lukianova, R., E-mail: [Geophysical Center of Russian Academy of Science, Moscow (Russian Federation)


    In the declining phase of the solar cycle (SC), when the new-polarity fields of the solar poles are strengthened by the transport of same-signed magnetic flux from lower latitudes, the polar coronal holes expand and form non-axisymmetric extensions toward the solar equator. These extensions enhance the occurrence of high-speed solar wind (SW) streams (HSS) and related co-rotating interaction regions in the low-latitude heliosphere, and cause moderate, recurrent geomagnetic activity (GA) in the near-Earth space. Here, using a novel definition of GA at high (polar cap) latitudes and the longest record of magnetic observations at a polar cap station, we calculate the annually averaged SW speeds as proxies for the effective annual occurrence of HSS over the whole Grand Modern Maximum (GMM) from 1920s onward. We find that a period of high annual speeds (frequent occurrence of HSS) occurs in the declining phase of each of SCs 16-23. For most cycles the HSS activity clearly reaches a maximum in one year, suggesting that typically only one strong activation leading to a coronal hole extension is responsible for the HSS maximum. We find that the most persistent HSS activity occurred in the declining phase of SC 18. This suggests that cycle 19, which marks the sunspot maximum period of the GMM, was preceded by exceptionally strong polar fields during the previous sunspot minimum. This gives interesting support for the validity of solar dynamo theory during this dramatic period of solar magnetism.

  5. Triadic conceptual structure of the maximum entropy approach to evolution.

    Herrmann-Pillath, Carsten; Salthe, Stanley N


    Many problems in evolutionary theory are cast in dyadic terms, such as the polar oppositions of organism and environment. We argue that a triadic conceptual structure offers an alternative perspective under which the information generating role of evolution as a physical process can be analyzed, and propose a new diagrammatic approach. Peirce's natural philosophy was deeply influenced by his reception of both Darwin's theory and thermodynamics. Thus, we elaborate on a new synthesis which puts together his theory of signs and modern Maximum Entropy approaches to evolution in a process discourse. Following recent contributions to the naturalization of Peircean semiosis, pointing towards 'physiosemiosis' or 'pansemiosis', we show that triadic structures involve the conjunction of three different kinds of causality, efficient, formal and final. In this, we accommodate the state-centered thermodynamic framework to a process approach. We apply this on Ulanowicz's analysis of autocatalytic cycles as primordial patterns of life. This paves the way for a semiotic view of thermodynamics which is built on the idea that Peircean interpretants are systems of physical inference devices evolving under natural selection. In this view, the principles of Maximum Entropy, Maximum Power, and Maximum Entropy Production work together to drive the emergence of information carrying structures, which at the same time maximize information capacity as well as the gradients of energy flows, such that ultimately, contrary to Schrödinger's seminal contribution, the evolutionary process is seen to be a physical expression of the Second Law.

  6. Maximum Safety Regenerative Power Tracking for DC Traction Power Systems

    Guifu Du


    Full Text Available Direct current (DC traction power systems are widely used in metro transport systems, with running rails usually being used as return conductors. When traction current flows through the running rails, a potential voltage known as “rail potential” is generated between the rails and ground. Currently, abnormal rises of rail potential exist in many railway lines during the operation of railway systems. Excessively high rail potentials pose a threat to human life and to devices connected to the rails. In this paper, the effect of regenerative power distribution on rail potential is analyzed. Maximum safety regenerative power tracking is proposed for the control of maximum absolute rail potential and energy consumption during the operation of DC traction power systems. The dwell time of multiple trains at each station and the trigger voltage of the regenerative energy absorbing device (READ are optimized based on an improved particle swarm optimization (PSO algorithm to manage the distribution of regenerative power. In this way, the maximum absolute rail potential and energy consumption of DC traction power systems can be reduced. The operation data of Guangzhou Metro Line 2 are used in the simulations, and the results show that the scheme can reduce the maximum absolute rail potential and energy consumption effectively and guarantee the safety in energy saving of DC traction power systems.

  7. Maximum work extraction and implementation costs for nonequilibrium Maxwell's demons

    Sandberg, Henrik; Delvenne, Jean-Charles; Newton, Nigel J.; Mitter, Sanjoy K.


    We determine the maximum amount of work extractable in finite time by a demon performing continuous measurements on a quadratic Hamiltonian system subjected to thermal fluctuations, in terms of the information extracted from the system. The maximum work demon is found to apply a high-gain continuous feedback involving a Kalman-Bucy estimate of the system state and operates in nonequilibrium. A simple and concrete electrical implementation of the feedback protocol is proposed, which allows for analytic expressions of the flows of energy, entropy, and information inside the demon. This let us show that any implementation of the demon must necessarily include an external power source, which we prove both from classical thermodynamics arguments and from a version of Landauer's memory erasure argument extended to nonequilibrium linear systems.

  8. Optimal Control of Polymer Flooding Based on Maximum Principle

    Yang Lei


    Full Text Available Polymer flooding is one of the most important technologies for enhanced oil recovery (EOR. In this paper, an optimal control model of distributed parameter systems (DPSs for polymer injection strategies is established, which involves the performance index as maximum of the profit, the governing equations as the fluid flow equations of polymer flooding, and the inequality constraint as the polymer concentration limitation. To cope with the optimal control problem (OCP of this DPS, the necessary conditions for optimality are obtained through application of the calculus of variations and Pontryagin’s weak maximum principle. A gradient method is proposed for the computation of optimal injection strategies. The numerical results of an example illustrate the effectiveness of the proposed method.

  9. Coronal Dynamic Activities in the Declining Phase of a Solar Cycle

    Jang, Minhwan; Hong, Sunhak; Choe, G S


    It has been known that some solar activity indicators show a double-peak feature in their evolution through a solar cycle, which is not conspicuous in sunspot number. In this letter, we investigate the high solar dynamic activity in the declining phase of the sunspot cycle by examining the evolution of polar and low latitude coronal hole areas and the statistics of splitting and merging events of coronal holes and coronal mass ejections detected by SOHO/LASCO C3 in solar cycle 23. Although the total coronal hole area is at its maximum near the sunspot minimum, in which polar coronal holes prevail, it shows a comparable second maximum in the declining phase of the cycle, in which low latitude coronal holes are dominant. The events of coronal hole splitting or merging, which are attributed to surface motions of magnetic fluxes, are also mostly populated in the declining phase of the cycle. The far-reaching C3 coronal mass ejections are also over-populated in the declining phase of the cycle. From these results ...

  10. Effective soil hydraulic conductivity predicted with the maximum power principle

    Westhoff, Martijn; Erpicum, Sébastien; Archambeau, Pierre; Pirotton, Michel; Zehe, Erwin; Dewals, Benjamin


    Drainage of water in soils happens for a large extent through preferential flowpaths, but these subsurface flowpaths are extremely difficult to observe or parameterize in hydrological models. To potentially overcome this problem, thermodynamic optimality principles have been suggested to predict effective parametrization of these (sub-grid) structures, such as the maximum entropy production principle or the equivalent maximum power principle. These principles have been successfully applied to predict heat transfer from the Equator to the Poles, or turbulent heat fluxes between the surface and the atmosphere. In these examples, the effective flux adapts itself to its boundary condition by adapting its effective conductance through the creation of e.g. convection cells. However, flow through porous media, such as soils, can only quickly adapt its effective flow conductance by creation of preferential flowpaths, but it is unknown if this is guided by the aim to create maximum power. Here we show experimentally that this is indeed the case: In the lab, we created a hydrological analogue to the atmospheric model dealing with heat transport between Equator and poles. The experimental setup consists of two freely draining reservoirs connected with each other by a confined aquifer. By adding water to only one reservoir, a potential difference will build up until a steady state is reached. From the steady state potential difference and the observed flow through the aquifer, and effective hydraulic conductance can be determined. This observed conductance does correspond to the one maximizing power of the flux through the confined aquifer. Although this experiment is done in an idealized setting, it opens doors for better parameterizing hydrological models. Furthermore, it shows that hydraulic properties of soils are not static, but they change with changing boundary conditions. A potential limitation to the principle is that it only applies to steady state conditions

  11. The analysis and kinetic energy balance of an upper-level wind maximum during intense convection

    Fuelberg, H. E.; Jedlovec, G. J.


    The purpose of this paper is to analyze the formation and maintenance of the upper-level wind maximum which formed between 1800 and 2100 GMT, April 10, 1979, during the AVE-SESAME I period, when intense storms and tornadoes were experienced (the Red River Valley tornado outbreak). Radiosonde stations participating in AVE-SESAME I are plotted (centered on Oklahoma). National Meteorological Center radar summaries near the times of maximum convective activity are mapped, and height and isotach plots are given, where the formation of an upper-level wind maximum over Oklahoma is the most significant feature at 300 mb. The energy balance of the storm region is seen to change dramatically as the wind maximum forms. During much of its lifetime, the upper-level wind maximum is maintained by ageostrophic flow that produces cross-contour generation of kinetic energy and by the upward transport of midtropospheric energy. Two possible mechanisms for the ageostrophic flow are considered.

  12. Intraguild predation and native lady beetle decline.

    Mary M Gardiner

    Full Text Available Coccinellid communities across North America have experienced significant changes in recent decades, with declines in several native species reported. One potential mechanism for these declines is interference competition via intraguild predation; specifically, increased predation of native coccinellid eggs and larvae following the introduction of exotic coccinellids. Our previous studies have shown that agricultural fields in Michigan support a higher diversity and abundance of exotic coccinellids than similar fields in Iowa, and that the landscape surrounding agricultural fields across the north central U.S. influences the abundance and activity of coccinellid species. The goal of this study was to quantify the amount of egg predation experienced by a native coccinellid within Michigan and Iowa soybean fields and explore the influence of local and large-scale landscape structure. Using the native lady beetle Coleomegilla maculata as a model, we found that sentinel egg masses were subject to intense predation within both Michigan and Iowa soybean fields, with 60.7% of egg masses attacked and 43.0% of available eggs consumed within 48 h. In Michigan, the exotic coccinellids Coccinella septempunctata and Harmonia axyridis were the most abundant predators found in soybean fields whereas in Iowa, native species including C. maculata, Hippodamia parenthesis and the soft-winged flower beetle Collops nigriceps dominated the predator community. Predator abundance was greater in soybean fields within diverse landscapes, yet variation in predator numbers did not influence the intensity of egg predation observed. In contrast, the strongest predictor of native coccinellid egg predation was the composition of edge habitats bordering specific fields. Field sites surrounded by semi-natural habitats including forests, restored prairies, old fields, and pasturelands experienced greater egg predation than fields surrounded by other croplands. This study shows

  13. Antihypertensive treatments, cognitive decline, and dementia.

    Duron, Emmanuelle; Hanon, Olivier


    Chronic hypertension is associated with an increased risk of both vascular dementia and Alzheimer's disease (AD). In this context, the role of anti-hypertensive therapy for the prevention and delay of cognitive decline and dementia is of central importance. Most longitudinal studies have shown a significant inverse association between anti-hypertensive therapies and dementia incidence and for some of these, particularly in AD. Seven randomized, double blind placebo-controlled trials have evaluated the benefit of antihypertensive treatments on cognition. Three of them found positive results in term of prevention of dementia (SYST-EUR) or cognitive decline (PROGRESS, HOPE). Others disclosed non-significant results (MRC, SHEP, SCOPE, HYVET-COG). This discrepancy emphasizes the difficulty to perform such trials: the follow-up has to be long enough to disclose a benefit, a large number of patients is needed for these studies, and because of ethical reasons some anti-hypertensive treatments are often prescribed in the placebo group. Results of the two more recent meta-analyses are inconsistent, possibly due to methodological issues. Antihypertensive treatments could be beneficial to cognitive function by lowering blood pressure and/or by specific neuroprotective effect. Three main antihypertensive subclasses have been associated with a beneficial effect on cognitive function beyond blood pressure reduction (calcium channel blockers, angiotensin converting enzyme inhibitor, angiotensin-AT1-receptor-blockers). Further long-term randomized trials, designed especially to assess a link between antihypertensive therapy and cognitive decline or dementia are therefore needed with cognition as the primary outcome. A low blood pressure threshold that could be deleterious for cognitive function should also be determined.


    LUO Wan-Jing; WANG Xiao-dong


    In a low permeability reservoir,the existence of a moving boundary is considered in the study of the transient porous flow with threshold pressure gradient.The transmission of the moving boundary directly indicates the size of the drainage area as well as the apparent influences on the pressure behavior.The nonlinear transient flow mathematical model in which the threshold pressure gradient and the moving boundary are incorporated is solved by advanced mathematical methods.This paper presents some new analytical solutions describing the pressure distribution at a constant rate and the production decline in a constant pressure production with the boundary propagation.It is shown that the greater the threshold pressure gradient,the slower the transmission of the moving boundary,the larger the pressure loss will be,and there is no radial flow in the middle and later phases of the wellface pressure for a well at a constant rate.We have the the maximum moving boundary at a specific drawdown pressure for a low permeability reservoir.The greater the threshold pressure gradient,the smaller the maximum moving boundary distance,the quieker the production decline for a well in a constant pressure production will be.The type curve charts for the modem well test analysis and the rate transient analysis with a moving boundary are obtained and the field test and the production data are interpreted as examples to illustrate how to use our new results.

  15. Differentiated decline in Danish outskirt areas

    Laursen, Lea Louise Holst; Andersson, Lasse


    The latest figures show that minor Danish villages and rural areas through the last 20 years have suffered from depopulation and economical decline, and it is a development that seems to accelerate. The negative consequences of this development are low house prizes, a higher unemployment rate tha...... life by rethinking existing structures into new landscape based spaces. This paper argues that a process oriented approach in landscape urbanism (Waldheim 2006, Corner 1999) and cultural planning (Evans 2001, Bianchini 1993) is useful when operating in smaller Danish communities....

  16. Decline in male circumcision in South Korea

    Kim DaiSik


    Full Text Available Abstract Background To investigate the changing circumcision rate in South Korea in the last decade and to propose underlying causes for this change, in the context of the present fluctuating world-wide trends in circumcision. Methods From 2009 to 2011, 3,296 South Korean males (or their parents aged 0–64 years were asked about their circumcision status, their age at circumcision, and their information level regarding circumcision. We employed non-probability sampling considering the sensitive questions on the study theme. Results Currently the age-standardized circumcision rate for South Korean males aged 14–29 is found to be 75.8%. In an earlier study performed in 2002, the rate for the same age group was 86.3%. Of particular interest, males aged 14–16 show a circumcision rate of 56.4%, while the same age group 10 years ago displayed a much higher percentage, at 88.4%. In addition, the extraordinarily high circumcision rate of 95.2% found 10 years ago for the 17–19 age group is now reduced to 74.4%. Interestingly, of the circumcised males, the percentage circumcised in the last decade was only 25.2%; i.e., the majority of the currently circumcised males had undergone the operation prior to 2002, indicating that the actual change in the last decade is far greater. Consistent with this conjecture, the 2002 survey showed that the majority of circumcised males (75.7% had undergone the operation in the decade prior to that point. Focusing on the flagship age group of 14–16, this drop suggests that, considering the population structure of Korean males, approximately one million fewer circumcision operations have been performed in the last decade relative to the case of non-decline. This decline is strongly correlated with the information available through internet, newspapers, lectures, books, and television: within the circumcised population, both the patients and their parents had less prior knowledge regarding circumcision, other than

  17. A dual method for maximum entropy restoration

    Smith, C. B.


    A simple iterative dual algorithm for maximum entropy image restoration is presented. The dual algorithm involves fewer parameters than conventional minimization in the image space. Minicomputer test results for Fourier synthesis with inadequate phantom data are given.

  18. Maximum Throughput in Multiple-Antenna Systems

    Zamani, Mahdi


    The point-to-point multiple-antenna channel is investigated in uncorrelated block fading environment with Rayleigh distribution. The maximum throughput and maximum expected-rate of this channel are derived under the assumption that the transmitter is oblivious to the channel state information (CSI), however, the receiver has perfect CSI. First, we prove that in multiple-input single-output (MISO) channels, the optimum transmission strategy maximizing the throughput is to use all available antennas and perform equal power allocation with uncorrelated signals. Furthermore, to increase the expected-rate, multi-layer coding is applied. Analogously, we establish that sending uncorrelated signals and performing equal power allocation across all available antennas at each layer is optimum. A closed form expression for the maximum continuous-layer expected-rate of MISO channels is also obtained. Moreover, we investigate multiple-input multiple-output (MIMO) channels, and formulate the maximum throughput in the asympt...

  19. Photoemission spectromicroscopy with MAXIMUM at Wisconsin

    Ng, W.; Ray-Chaudhuri, A.K.; Cole, R.K.; Wallace, J.; Crossley, S.; Crossley, D.; Chen, G.; Green, M.; Guo, J.; Hansen, R.W.C.; Cerrina, F.; Margaritondo, G. (Dept. of Electrical Engineering, Dept. of Physics and Synchrotron Radiation Center, Univ. of Wisconsin, Madison (USA)); Underwood, J.H.; Korthright, J.; Perera, R.C.C. (Center for X-ray Optics, Accelerator and Fusion Research Div., Lawrence Berkeley Lab., CA (USA))


    We describe the development of the scanning photoemission spectromicroscope MAXIMUM at the Wisoncsin Synchrotron Radiation Center, which uses radiation from a 30-period undulator. The article includes a discussion of the first tests after the initial commissioning. (orig.).

  20. Maximum-likelihood method in quantum estimation

    Paris, M G A; Sacchi, M F


    The maximum-likelihood method for quantum estimation is reviewed and applied to the reconstruction of density matrix of spin and radiation as well as to the determination of several parameters of interest in quantum optics.

  1. The maximum entropy technique. System's statistical description

    Belashev, B Z


    The maximum entropy technique (MENT) is applied for searching the distribution functions of physical values. MENT takes into consideration the demand of maximum entropy, the characteristics of the system and the connection conditions, naturally. It is allowed to apply MENT for statistical description of closed and open systems. The examples in which MENT had been used for the description of the equilibrium and nonequilibrium states and the states far from the thermodynamical equilibrium are considered

  2. 19 CFR 114.23 - Maximum period.


    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Maximum period. 114.23 Section 114.23 Customs... CARNETS Processing of Carnets § 114.23 Maximum period. (a) A.T.A. carnet. No A.T.A. carnet with a period of validity exceeding 1 year from date of issue shall be accepted. This period of validity cannot be...

  3. Maximum-Likelihood Detection Of Noncoherent CPM

    Divsalar, Dariush; Simon, Marvin K.


    Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.


    Pandya A M


    Full Text Available Sexual identification from the skeletal parts has medico legal and anthropological importance. Present study aims to obtain values of maximum femoral length and to evaluate its possible usefulness in determining correct sexual identification. Study sample consisted of 184 dry, normal, adult, human femora (136 male & 48 female from skeletal collections of Anatomy department, M. P. Shah Medical College, Jamnagar, Gujarat. Maximum length of femur was considered as maximum vertical distance between upper end of head of femur and the lowest point on femoral condyle, measured with the osteometric board. Mean Values obtained were, 451.81 and 417.48 for right male and female, and 453.35 and 420.44 for left male and female respectively. Higher value in male was statistically highly significant (P< 0.001 on both sides. Demarking point (D.P. analysis of the data showed that right femora with maximum length more than 476.70 were definitely male and less than 379.99 were definitely female; while for left bones, femora with maximum length more than 484.49 were definitely male and less than 385.73 were definitely female. Maximum length identified 13.43% of right male femora, 4.35% of right female femora, 7.25% of left male femora and 8% of left female femora. [National J of Med Res 2011; 1(2.000: 67-70

  5. Magnetic observations during the recent declining phase of solar activity

    Smith, E. J.

    Changes in the heliospheric magnetic field during the recent declining phase in solar activity are reviewed and compared with observations during past sunspot cycles. The study is based principally on data obtained by IMP-8 and Ulysses. The field magnitude is found to have increased during the declining phase until it reached a maximum value of 11.5nT in approximately 1991.5, approximately two years after sunspot maximum. The field of the sun's south pole became negative after a reversal in early 1990. The sector structure disappeared at Ulysses in April 1993 when the latitude of the spacecraft was -30 deg revealing a low inclination of the heliospheric current sheet. A large outburst of solar activity in March 1991 caused four Coronal Mass Ejections (CMEs) and numerious shocks at the location of Ulysses. Following a delay of more than a year, a series of recurrent high speed streams and Corotating Interaction Regions commenced in July 1992 which were observed by IMP-8, Ulysses and Voyager 2. In all these respects, the behavior of the magnetic field mimics that seen in the two earlier sunspot cycles. The comprehensive data set suggests a correlation between the absolute value of B and sunspot number. The major solar cycle variations in the radial component (and magnitude) of the field have been successfully reproduced by a recent model consisting of a tilted solar dipole, whose strength and tilt undergo characteristic changes over the sunspot cycle, and the heliospheric current sheet. The large outbursts of activity in mid-1972, mid-1982 and the first quarter of 1991 may represent a characteristic last 'gasp' of solar activity before the sun evolves to a different state. The recurrent high speed streams in 1973, 1984 and 1992 accompany the developemnt of large asymetrical polar coronal holes and the growth in intensity of the polar cap fields. After they endure for about one year, the polar coronal holes recede and the high speed streams are replaced by weaker

  6. The impact of freedom on fertility decline.

    Campbell, Martha M; Prata, Ndola; Potts, Malcolm


    Although fertility decline often correlates with improvements in socioeconomic conditions, many demographers have found flaws in demographic transition theories that depend on changes in distal factors such as increased wealth or education. Human beings worldwide engage in sexual intercourse much more frequently than is needed to conceive the number of children they want, and for women who do not have access to the information and means they need to separate sex from childbearing, the default position is a large family. In many societies, male patriarchal drives to control female reproduction give rise to unnecessary medical rules constraining family planning (including safe abortion) or justifying child marriage. Widespread misinformation about contraception makes women afraid to adopt modern family planning. The barriers to family planning can be so deeply infused that for many women the idea of managing their fertility is not considered an option. Conversely, there is evidence that once family planning is introduced into a society, then it is normal consumer behaviour for individuals to welcome a new technology they had not wanted until it became realistically available. We contend that in societies free from child marriage, wherever women have access to a range of contraceptive methods, along with correct information and backed up by safe abortion, family size will always fall. Education and wealth can make the adoption of family planning easier, but they are not prerequisites for fertility decline. By contrast, access to family planning itself can accelerate economic development and the spread of education.

  7. The Decline of Traditional Banking Activities

    Gabriela Cornelia Piciu


    Full Text Available The decline of traditional banking activities raise the issue of efficiency of financial stability, in terms ofquantitative and qualitative aspects – the increasing danger of banking failures as well as of susceptibility due toincreased propensity of banking institutions to assume additional to risks either in the form of riskier loans offer orengaging in other "non-traditional" financial activities which give a promise for greater profitability, but also higherrisks. Non-traditional activities of banking as financial products dealers (financial derivatives, generate an increasingrisks and vulnerabilities in the form of moral hazard issues. That is the reason why and these activities should beregulated as well as are the traditional activities. Challenges posed by the decline of traditional banking activities istwofold: the stability of the banking system must be maintained, while the banking system needs to be restructured toachieve financial stability in the long run. One possible way is an appropriate regulatory framework to encourage atransition period of changing the structure of banking activity(reduction of traditional activities and expanding nontraditional activities to enable banking institutions to perform a deep methodic analysis of non traditional activities,oriented to the financial banking efficiency.

  8. Dehydroepiandrosterone and age-related cognitive decline.

    Sorwell, Krystina G; Urbanski, Henryk F


    In humans the circulating concentrations of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) decrease markedly during aging, and have been implicated in age-associated cognitive decline. This has led to the hypothesis that DHEA supplementation during aging may improve memory. In rodents, a cognitive anti-aging effect of DHEA and DHEAS has been observed but it is unclear whether this effect is mediated indirectly through conversion of these steroids to estradiol. Moreover, despite the demonstration of correlations between endogenous DHEA concentrations and cognitive ability in certain human patient populations, such correlations have yet to be convincingly demonstrated during normal human aging. This review highlights important differences between rodents and primates in terms of their circulating DHEA and DHEAS concentrations, and suggests that age-related changes within the human DHEA metabolic pathway may contribute to the relative inefficacy of DHEA replacement therapies in humans. The review also highlights the value of using nonhuman primates as a pragmatic animal model for testing the therapeutic potential of DHEA for age-associate cognitive decline in humans.

  9. Declining suburbs in Europe and Latin America.

    Audirac, Ivonne; Cunningham-Sabot, Emmanuèle; Fol, Sylvie; Moraes, Sergio Torres


    Suburban shrinkage, understood as a degenerative urban process stemming from the demise of the Fordist mode of urbanism, is generally manifested in a decline in population, industry and employment. It is also intimately linked to the global restructuring of industrial organization associated with the rise of the post-Fordist mode of urbanism and, more recently, the thrust of Asian industrialization. Framed in the discourse of industrial urbanism, this article examines the first ring of industrial suburbs that developed around large cities in their most rapid Fordist urbanization phase. These industrial suburbs, although they were formed at different times, are today experiencing specific mutations and undergoing profound restructuring on account of their particular spatial position between the central area and the expanding peripheries of the post-Fordist metropolis. This article describes and compares suburban decline in two European cities (Glasgow and Paris) and two Latin American Cities (São Paulo, Brazil and Guadalajara, Mexico), as different instances of places asymmetrically and fragmentarily integrated into the geography of globalization.

  10. Musculoskeletal health, frailty and functional decline.

    Milte, R; Crotty, M


    Frailty in older people is associated with a vulnerability to adverse events. While ageing is associated with a loss of physiological reserves, identifying those with the syndrome of frailty has the potential to assist clinicians to tailor treatments to those at the risk of future decline into disability with an increased risk of complications, morbidity and mortality. Sarcopenia is a key component of the frailty syndrome and on its own puts older people at risk of fragility fractures; however, the clinical syndrome of frailty affects the musculoskeletal and non-musculoskeletal systems. Hip fractures are becoming a prototype condition in the study of frailty. Following a hip fracture, many of the interventions are focused on limiting mobility disability and restoring independence with activities of daily living, but there are multiple factors to be addressed including osteoporosis, sarcopenia, delirium and weight loss. Established techniques of geriatric evaluation and management allow systematic assessment and intervention on multiple components by multidisciplinary teams and deliver the best outcomes. Using the concept of frailty to identify older people with musculoskeletal problems as being at the risk of a poor outcome assists in treatment planning and is likely to become more important as effective pharmacological treatments for sarcopenia emerge. This review will focus on the concept of frailty and its relationship with functional decline, as well as describing its causes, prevalence, risk factors, potential clinical applications and treatment strategies.

  11. Status and trends of amphibian declines and extinctions worldwide.

    Stuart, Simon N; Chanson, Janice S; Cox, Neil A; Young, Bruce E; Rodrigues, Ana S L; Fischman, Debra L; Waller, Robert W


    The first global assessment of amphibians provides new context for the well-publicized phenomenon of amphibian declines. Amphibians are more threatened and are declining more rapidly than either birds or mammals. Although many declines are due to habitat loss and overutilization, other, unidentified processes threaten 48% of rapidly declining species and are driving species most quickly to extinction. Declines are nonrandom in terms of species' ecological preferences, geographic ranges, and taxonomic associations and are most prevalent among Neotropical montane, stream-associated species. The lack of conservation remedies for these poorly understood declines means that hundreds of amphibian species now face extinction.

  12. Solar-Cycle Variation of Subsurface-Flow Divergence: A Proxy of Magnetic Activity?

    Komm, R.; Howe, R.; Hill, F.


    We study the solar-cycle variation of subsurface flows from the surface to a depth of 16 Mm. We have analyzed Global Oscillation Network Group (GONG) Dopplergrams with a ring-diagram analysis covering about 15 years and Helioseismic and Magnetic Imager (HMI) Dopplergrams covering more than 6 years. After subtracting the average rotation rate and meridional flow, we have calculated the divergence of the horizontal residual flows from the maximum of Solar Cycle 23 through the declining phase of Cycle 24. The subsurface flows are mainly divergent at quiet regions and convergent at locations of high magnetic activity. The relationship is essentially linear between divergence and magnetic activity at all activity levels at depths shallower than about 10 Mm. At greater depths, the relationship changes sign at locations of high activity; the flows are increasingly divergent at locations with a magnetic activity index (MAI) greater than about 24 G. The flows are more convergent by about a factor of two during the rising phase of Cycle 24 than during the declining phase of Cycle 23 at locations of medium and high activity (about 10 to 40 G MAI) from the surface to at least 10 Mm. The subsurface divergence pattern of Solar Cycle 24 first appears during the declining phase of Cycle 23 and is present during the extended minimum. It appears several years before the magnetic pattern of the new cycle is noticeable in synoptic maps. Using linear regression, we estimate the amount of magnetic activity that would be required to generate the precursor pattern and find that it should be almost twice the amount of activity that is observed.

  13. Flow Based Algorithm

    T. Karpagam


    Full Text Available Problem statement: Network topology design problems find application in several real life scenario. Approach: Most designs in the past either optimize for a single criterion like shortest or cost minimization or maximum flow. Results: This study discussed about solving a multi objective network topology design problem for a realistic traffic model specifically in the pipeline transportation. Here flow based algorithm focusing to transport liquid goods with maximum capacity with shortest distance, this algorithm developed with the sense of basic pert and critical path method. Conclusion/Recommendations: This flow based algorithm helps to give optimal result for transporting maximum capacity with minimum cost. It could be used in the juice factory, milk industry and its best alternate for the vehicle routing problem.

  14. The maximum rotation of a galactic disc

    Bottema, R


    The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously rising rotation curve until the outermost measured radial position. That is why a general relation has been derived, giving the maximum rotation for a disc depending on the luminosity, surface brightness, and colour of the disc. As a physical basis of this relation serves an adopted fixed mass-to-light ratio as a function of colour. That functionality is consistent with results from population synthesis models and its absolute value is determined from the observed stellar velocity dispersions. The derived maximum disc rotation is compared with a number of observed maximum rotations, clearly demonstrating the need for appreciable amounts of dark matter in the disc region and even more so for LSB galaxies. Matters h...

  15. Maximum permissible voltage of YBCO coated conductors

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.


    Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  16. Computing Rooted and Unrooted Maximum Consistent Supertrees

    van Iersel, Leo


    A chief problem in phylogenetics and database theory is the computation of a maximum consistent tree from a set of rooted or unrooted trees. A standard input are triplets, rooted binary trees on three leaves, or quartets, unrooted binary trees on four leaves. We give exact algorithms constructing rooted and unrooted maximum consistent supertrees in time O(2^n n^5 m^2 log(m)) for a set of m triplets (quartets), each one distinctly leaf-labeled by some subset of n labels. The algorithms extend to weighted triplets (quartets). We further present fast exact algorithms for constructing rooted and unrooted maximum consistent trees in polynomial space. Finally, for a set T of m rooted or unrooted trees with maximum degree D and distinctly leaf-labeled by some subset of a set L of n labels, we compute, in O(2^{mD} n^m m^5 n^6 log(m)) time, a tree distinctly leaf-labeled by a maximum-size subset X of L that all trees in T, when restricted to X, are consistent with.

  17. Maximum magnitude earthquakes induced by fluid injection

    McGarr, Arthur F.


    Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.

  18. Maximum magnitude earthquakes induced by fluid injection

    McGarr, A.


    Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.

  19. Relation between age-related decline in intelligence and cerebral white-matter hyperintensities in healthy octogenarians: a longitudinal study

    Garde, E; Mortensen, E L; Krabbe, K


    , but no participant scored more than 75% of maximum for deep white-matter hyperintensities. Neither type was related to the WAIS IQs of the 80-year assessment, but both were significantly associated with decline in performance IQ from age 50 to age 80 years (bivariate correlation coefficients 0.32, p=0.0087, and 0...

  20. Mathematical Modeling of Electrolyte Flow Dynamic Patterns and Volumetric Flow Penetrations in the Flow Channel over Porous Electrode Layered System in Vanadium Flow Battery with Serpentine Flow Field Design

    Ke, Xinyou; Alexander, J Iwan D; Savinell, Robert F


    In this work, a two-dimensional mathematical model is developed to study the flow patterns and volumetric flow penetrations in the flow channel over the porous electrode layered system in vanadium flow battery with serpentine flow field design. The flow distributions at the interface between the flow channel and porous electrode are examined. It is found that the non-linear pressure distributions can distinguish the interface flow distributions under the ideal plug flow and ideal parabolic flow inlet boundary conditions. However, the volumetric flow penetration within the porous electrode beneath the flow channel through the integration of interface flow velocity reveals that this value is identical under both ideal plug flow and ideal parabolic flow inlet boundary conditions. The volumetric flow penetrations under the advection effects of flow channel and landing/rib are estimated. The maximum current density achieved in the flow battery can be predicted based on the 100% amount of electrolyte flow reactant ...


    This study identified the factors responsible for the decline of native amphibians in the U.S. The type of land use, the introduction of exotic animal species, and chemical contamination were identified as the most likely causes of decline.

  2. Maximum Entropy for the International Division of Labor.

    Lei, Hongmei; Chen, Ying; Li, Ruiqi; He, Deli; Zhang, Jiang


    As a result of the international division of labor, the trade value distribution on different products substantiated by international trade flows can be regarded as one country's strategy for competition. According to the empirical data of trade flows, countries may spend a large fraction of export values on ubiquitous and competitive products. Meanwhile, countries may also diversify their exports share on different types of products to reduce the risk. In this paper, we report that the export share distribution curves can be derived by maximizing the entropy of shares on different products under the product's complexity constraint once the international market structure (the country-product bipartite network) is given. Therefore, a maximum entropy model provides a good fit to empirical data. The empirical data is consistent with maximum entropy subject to a constraint on the expected value of the product complexity for each country. One country's strategy is mainly determined by the types of products this country can export. In addition, our model is able to fit the empirical export share distribution curves of nearly every country very well by tuning only one parameter.

  3. Maximum Multiflow in Wireless Network Coding

    Zhou, Jin-Yi; Jiang, Yong; Zheng, Hai-Tao


    In a multihop wireless network, wireless interference is crucial to the maximum multiflow (MMF) problem, which studies the maximum throughput between multiple pairs of sources and sinks. In this paper, we observe that network coding could help to decrease the impacts of wireless interference, and propose a framework to study the MMF problem for multihop wireless networks with network coding. Firstly, a network model is set up to describe the new conflict relations modified by network coding. Then, we formulate a linear programming problem to compute the maximum throughput and show its superiority over one in networks without coding. Finally, the MMF problem in wireless network coding is shown to be NP-hard and a polynomial approximation algorithm is proposed.

  4. The Wiener maximum quadratic assignment problem

    Cela, Eranda; Woeginger, Gerhard J


    We investigate a special case of the maximum quadratic assignment problem where one matrix is a product matrix and the other matrix is the distance matrix of a one-dimensional point set. We show that this special case, which we call the Wiener maximum quadratic assignment problem, is NP-hard in the ordinary sense and solvable in pseudo-polynomial time. Our approach also yields a polynomial time solution for the following problem from chemical graph theory: Find a tree that maximizes the Wiener index among all trees with a prescribed degree sequence. This settles an open problem from the literature.

  5. Maximum confidence measurements via probabilistic quantum cloning

    Zhang Wen-Hai; Yu Long-Bao; Cao Zhuo-Liang; Ye Liu


    Probabilistic quantum cloning (PQC) cannot copy a set of linearly dependent quantum states.In this paper,we show that if incorrect copies are allowed to be produced,linearly dependent quantum states may also be cloned by the PQC.By exploiting this kind of PQC to clone a special set of three linearly dependent quantum states,we derive the upper bound of the maximum confidence measure of a set.An explicit transformation of the maximum confidence measure is presented.

  6. Maximum floodflows in the conterminous United States

    Crippen, John R.; Bue, Conrad D.


    Peak floodflows from thousands of observation sites within the conterminous United States were studied to provide a guide for estimating potential maximum floodflows. Data were selected from 883 sites with drainage areas of less than 10,000 square miles (25,900 square kilometers) and were grouped into regional sets. Outstanding floods for each region were plotted on graphs, and envelope curves were computed that offer reasonable limits for estimates of maximum floods. The curves indicate that floods may occur that are two to three times greater than those known for most streams.

  7. Revealing the Maximum Strength in Nanotwinned Copper

    Lu, L.; Chen, X.; Huang, Xiaoxu


    The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  8. The Maximum Resource Bin Packing Problem

    Boyar, J.; Epstein, L.; Favrholdt, L.M.


    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

  9. Maximum entropy analysis of EGRET data

    Pohl, M.; Strong, A.W.


    EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....

  10. Revealing the Maximum Strength in Nanotwinned Copper

    Lu, L.; Chen, X.; Huang, Xiaoxu


    The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  11. Maximum phytoplankton concentrations in the sea

    Jackson, G.A.; Kiørboe, Thomas


    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collected...... in the North Atlantic as part of the Bermuda Atlantic Time Series program as well as data collected off Southern California as part of the Southern California Bight Study program. The observed maximum particulate organic carbon and volumetric particle concentrations are consistent with the predictions...

  12. Depressed Mood Mediates Decline in Cognitive Processing Speed in Caregivers

    Vitaliano, Peter P.; Zhang, Jianping; Young, Heather M.; Caswell, Lisa W.; Scanlan, James M.; Echeverria, Diana


    Purpose: Very few studies have examined cognitive decline in caregivers versus noncaregivers, and only 1 study has examined mediators of such decline. We evaluated the relationship between caregiver status and decline on the digit symbol test (DST; a measure of processing speed, attention, cognitive-motor translation, and visual scanning) and…

  13. 32 CFR 776.35 - Declining or terminating representation.


    ... 32 National Defense 5 2010-07-01 2010-07-01 false Declining or terminating representation. 776.35... ADVOCATE GENERAL Rules of Professional Conduct § 776.35 Declining or terminating representation. (a) Declining or terminating representation: (1) Except as stated in paragraph (a)(3) of this section, a covered...

  14. Sewing Machine Manufacturing Enterprises Saw Serious Profit Declines


    The raw materials that sewing machinery manufacturing required saw a decline in prices decline this year, but the market demand for sewing machinery falls sharply as well as the reduced demand in the international market, prices of the sewing machine parts are in a downturn trend. Therefore, the corporate profits decline seriously.

  15. The Test Score Decline: A Review and Annotated Bibliography


    J.R., The Test Score Decline: Are the Public Schools the Scapegoat? Part Two =129. K%’apfer. P., Kapfer , M., & Woodruff, A., Declining Test Scores...Michigan State University, August 1976. 129. Kapfer , P.F., Kapfer , M.B., & Woodruff, A.D., Declining test scores: Inter- pretations, issues, and relationship

  16. Satellite-derived estimates of forest leaf area index in southwest Western Australia are not tightly coupled to interannual variations in rainfall: implications for groundwater decline in a drying climate.

    Smettem, Keith R J; Waring, Richard H; Callow, John N; Wilson, Melissa; Mu, Qiaozhen


    There is increasing concern that widespread forest decline could occur in regions of the world where droughts are predicted to increase in frequency and severity as a result of climate change. The average annual leaf area index (LAI) is an indicator of canopy cover and the difference between the annual maximum and minimum LAI is an indicator of annual leaf turnover. In this study, we analyzed satellite-derived estimates of monthly LAI across forested coastal catchments of southwest Western Australia over a 12 year period (2000-2011) that included the driest year on record for the last 60 years. We observed that over the 12 year study period, the spatial pattern of average annual satellite-derived LAI values was linearly related to mean annual rainfall. However, interannual changes to LAI in response to changes in annual rainfall were far less than expected from the long-term LAI-rainfall trend. This buffered response was investigated using a physiological growth model and attributed to availability of deep soil moisture and/or groundwater storage. The maintenance of high LAIs may be linked to a long-term decline in areal average underground water storage and diminished summer flows, with an emerging trend toward more ephemeral flow regimes.

  17. Maximum-power-point tracking control of solar heating system

    Huang, Bin-Juine


    The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

  18. Analysis of Photovoltaic Maximum Power Point Trackers

    Veerachary, Mummadi

    The photovoltaic generator exhibits a non-linear i-v characteristic and its maximum power point (MPP) varies with solar insolation. An intermediate switch-mode dc-dc converter is required to extract maximum power from the photovoltaic array. In this paper buck, boost and buck-boost topologies are considered and a detailed mathematical analysis, both for continuous and discontinuous inductor current operation, is given for MPP operation. The conditions on the connected load values and duty ratio are derived for achieving the satisfactory maximum power point operation. Further, it is shown that certain load values, falling out of the optimal range, will drive the operating point away from the true maximum power point. Detailed comparison of various topologies for MPPT is given. Selection of the converter topology for a given loading is discussed. Detailed discussion on circuit-oriented model development is given and then MPPT effectiveness of various converter systems is verified through simulations. Proposed theory and analysis is validated through experimental investigations.

  19. On maximum cycle packings in polyhedral graphs

    Peter Recht


    Full Text Available This paper addresses upper and lower bounds for the cardinality of a maximum vertex-/edge-disjoint cycle packing in a polyhedral graph G. Bounds on the cardinality of such packings are provided, that depend on the size, the order or the number of faces of G, respectively. Polyhedral graphs are constructed, that attain these bounds.

  20. Hard graphs for the maximum clique problem

    Hoede, Cornelis


    The maximum clique problem is one of the NP-complete problems. There are graphs for which a reduction technique exists that transforms the problem for these graphs into one for graphs with specific properties in polynomial time. The resulting graphs do not grow exponentially in order and number. Gra

  1. Maximum Likelihood Estimation of Search Costs

    J.L. Moraga-Gonzalez (José Luis); M.R. Wildenbeest (Matthijs)


    textabstractIn a recent paper Hong and Shum (forthcoming) present a structural methodology to estimate search cost distributions. We extend their approach to the case of oligopoly and present a maximum likelihood estimate of the search cost distribution. We apply our method to a data set of online p

  2. Weak Scale From the Maximum Entropy Principle

    Hamada, Yuta; Kawana, Kiyoharu


    The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\

  3. Weak scale from the maximum entropy principle

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu


    The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.

  4. Global characterization of the Holocene Thermal Maximum

    Renssen, H.; Seppä, H.; Crosta, X.; Goosse, H.; Roche, D.M.V.A.P.


    We analyze the global variations in the timing and magnitude of the Holocene Thermal Maximum (HTM) and their dependence on various forcings in transient simulations covering the last 9000 years (9 ka), performed with a global atmosphere-ocean-vegetation model. In these experiments, we consider the i

  5. Instance Optimality of the Adaptive Maximum Strategy

    L. Diening; C. Kreuzer; R. Stevenson


    In this paper, we prove that the standard adaptive finite element method with a (modified) maximum marking strategy is instance optimal for the total error, being the square root of the squared energy error plus the squared oscillation. This result will be derived in the model setting of Poisson’s e

  6. Maximum phonation time: variability and reliability.

    Speyer, Renée; Bogaardt, Hans C A; Passos, Valéria Lima; Roodenburg, Nel P H D; Zumach, Anne; Heijnen, Mariëlle A M; Baijens, Laura W J; Fleskens, Stijn J H M; Brunings, Jan W


    The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia versus a group of healthy control subjects matched by age and gender. Over a period of maximally 6 weeks, three video recordings were made of five subjects' maximum phonation time trials. A panel of five experts were responsible for all measurements, including a repeated measurement of the subjects' first recordings. Patients showed significantly shorter maximum phonation times compared with healthy controls (on average, 6.6 seconds shorter). The averaged interclass correlation coefficient (ICC) over all raters per trial for the first day was 0.998. The averaged reliability coefficient per rater and per trial for repeated measurements of the first day's data was 0.997, indicating high intrarater reliability. The mean reliability coefficient per day for one trial was 0.939. When using five trials, the reliability increased to 0.987. The reliability over five trials for a single day was 0.836; for 2 days, 0.911; and for 3 days, 0.935. To conclude, the maximum phonation time has proven to be a highly reliable measure in voice assessment. A single rater is sufficient to provide highly reliable measurements.

  7. Maximum Phonation Time: Variability and Reliability

    R. Speyer; H.C.A. Bogaardt; V.L. Passos; N.P.H.D. Roodenburg; A. Zumach; M.A.M. Heijnen; L.W.J. Baijens; S.J.H.M. Fleskens; J.W. Brunings


    The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia v

  8. Maximum likelihood estimation of fractionally cointegrated systems

    Lasak, Katarzyna

    In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment...

  9. Maximum likelihood estimation for integrated diffusion processes

    Baltazar-Larios, Fernando; Sørensen, Michael

    EM-algorithm to obtain maximum likelihood estimates of the parameters in the diffusion model. As part of the algorithm, we use a recent simple method for approximate simulation of diffusion bridges. In simulation studies for the Ornstein-Uhlenbeck process and the CIR process the proposed method works...

  10. Maximum gain of Yagi-Uda arrays

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.


    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  11. Birthspacing and fertility decline in Costa Rica

    Víctor Gómez


    Full Text Available RESUMENEste trabajo utiliza datos de las Encuestas Comparativas de Fecundidad de América Latina, así como de la Encuesta Mundial de Fecundidad para estudiar las tendencias y diferenciales en el espaciamiento de los nacimientos entre las mujeres alguna vez casadas en Costa Rica durante el período 1945-1974. Una buena parte de la atención se pone en el ritmo de la fecundidad en las etapas umbral, temprana y tardía de la disminución de la fecundidad que este país experimentó durante los años sesenta y principios de los setenta. Los resultados muestran bastante similitud en el tempo de la reproducción en los diferentes niveles paridez y áreas geográficas. Sin embargo, un análisis de las variables del entorno que afectan espaciamiento de los nacimientos muestra diferencias entre las zonas urbanas y rurales. Por último, se postula que el reciente estancamiento en las tasas de período puede ser una consecuencia de los cambios en el tempo de construcción de la familia, con mujeres de baja paridez que postergan los nacimientos, lo que contrarresta las tendencias de descenso que generan las mujeres de mayor paridez quienes aún pueden estar restringiendo su reproducción.ABSTRACTThis paper uses data from the Latin American Comparative Fertility Surveys as well as from the World Fertility Survey to study trends and differentials in birthspacing among ever married women in Costa Rica during the period 1945-1974. A good deal of attention is placed on the pace of fertility in threshold, early and late stages of the fertility decline that this country experienced during the sixties and early seventies. The results show a good deal of similarity in the tempo of reproduction across parities and geographical areas.However, an analysis of the background variables affecting birthspacing shows differences between urban and rural zones. Finally, it is postulated that the recent plateau in period rates may be a consequence of changes in the tempo of

  12. Declining death rates reflect progress against cancer.

    Ahmedin Jemal

    Full Text Available BACKGROUND: The success of the "war on cancer" initiated in 1971 continues to be debated, with trends in cancer mortality variably presented as evidence of progress or failure. We examined temporal trends in death rates from all-cancer and the 19 most common cancers in the United States from 1970-2006. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed trends in age-standardized death rates (per 100,000 for all cancers combined, the four most common cancers, and 15 other sites from 1970-2006 in the United States using joinpoint regression model. The age-standardized death rate for all-cancers combined in men increased from 249.3 in 1970 to 279.8 in 1990, and then decreased to 221.1 in 2006, yielding a net decline of 21% and 11% from the 1990 and 1970 rates, respectively. Similarly, the all-cancer death rate in women increased from 163.0 in 1970 to 175.3 in 1991 and then decreased to 153.7 in 2006, a net decline of 12% and 6% from the 1991 and 1970 rates, respectively. These decreases since 1990/91 translate to preventing of 561,400 cancer deaths in men and 205,700 deaths in women. The decrease in death rates from all-cancers involved all ages and racial/ethnic groups. Death rates decreased for 15 of the 19 cancer sites, including the four major cancers, with lung, colorectum and prostate cancers in men and breast and colorectum cancers in women. CONCLUSIONS/SIGNIFICANCE: Progress in reducing cancer death rates is evident whether measured against baseline rates in 1970 or in 1990. The downturn in cancer death rates since 1990 result mostly from reductions in tobacco use, increased screening allowing early detection of several cancers, and modest to large improvements in treatment for specific cancers. Continued and increased investment in cancer prevention and control, access to high quality health care, and research could accelerate this progress.

  13. Inverse feasibility problems of the inverse maximum flow problems

    Adrian Deaconu; Eleonor Ciurea


    A linear time method to decide if any inverse maximum flow (denoted General Inverse Maximum Flow problems (IMFG)) problem has solution is deduced. If IMFG does not have solution, methods to transform IMFG into a feasible problem are presented. The methods consist of modifying as little as possible the restrictions to the variation of the bounds of the flow. New inverse combinatorial optimization problems are introduced and solved.

  14. The growth and decline of cryonics

    David Sanders Stodolsky


    Full Text Available Cryogenic storage has become known as an alternative to burial. While a substantial fraction of the public finds cryonics acceptable, enrollment remains miniscule. One of the greatest unknowns is whether cryonics companies will be able to operate continuously until reanimation of those in storage becomes possible. Two failure modes are considered; organizational decline and political attack. The cryonics industry has adopted a strategy that implicitly targets atheist millionaires and alienates women. This is a result of neglecting science in its marketing efforts. American cryonics organizations have also incurred an avoidable political risk by refusing to use the funeral industry as a sales channel. Two alternative strategies are suggested that could minimize failure risk by reversing the stagnation of the industry. A “repackaging” of cryonics could accelerate growth and improve services, as well as the political position of the industry. This repackaging includes a restructuring of the channels for funding cryonics. Integration with the mainstream assumes using the funeral industry as a sales channel. While both political experiences and research results have made the need for these developments apparent, pioneers of the industry have resisted them.

  15. Electrical stimulation counteracts muscle decline in seniors.

    Kern, Helmut; Barberi, Laura; Löfler, Stefan; Sbardella, Simona; Burggraf, Samantha; Fruhmann, Hannah; Carraro, Ugo; Mosole, Simone; Sarabon, Nejc; Vogelauer, Michael; Mayr, Winfried; Krenn, Matthias; Cvecka, Jan; Romanello, Vanina; Pietrangelo, Laura; Protasi, Feliciano; Sandri, Marco; Zampieri, Sandra; Musaro, Antonio


    The loss in muscle mass coupled with a decrease in specific force and shift in fiber composition are hallmarks of aging. Training and regular exercise attenuate the signs of sarcopenia. However, pathologic conditions limit the ability to perform physical exercise. We addressed whether electrical stimulation (ES) is an alternative intervention to improve muscle recovery and defined the molecular mechanism associated with improvement in muscle structure and function. We analyzed, at functional, structural, and molecular level, the effects of ES training on healthy seniors with normal life style, without routine sport activity. ES was able to improve muscle torque and functional performances of seniors and increased the size of fast muscle fibers. At molecular level, ES induced up-regulation of IGF-1 and modulation of MuRF-1, a muscle-specific atrophy-related gene. ES also induced up-regulation of relevant markers of differentiating satellite cells and of extracellular matrix remodeling, which might guarantee shape and mechanical forces of trained skeletal muscle as well as maintenance of satellite cell function, reducing fibrosis. Our data provide evidence that ES is a safe method to counteract muscle decline associated with aging.

  16. Cognitive decline and the default American lifestyle.

    Mirowsky, John


    Upward trends in IQ, education, and mental work suggest that cognitive function among seniors should be rising strongly across cohorts. There is little sign of such improvement in recent decades, and some analyses find poorer function in the newer cohorts. This essay explores possible explanations of the anomaly. Major long-term trends that might increase cognitive impairment are reviewed, and their implications are considered. Physical activity is declining, food is increasingly manufactured, body fat is increasing, diabetes and metabolic syndrome are on the rise, the number of prescription drugs per person is increasing, and the proportion of the population either old or obese is growing. Technological and economic development may lower the cognitive function needed for survival. They also lower physical activity in daily life. Sedentary work, transportation, and leisure undermine the aerobic and metabolic fitness required for the brain to perform well. Some prescription drugs impair cognitive function, and others do so when taken for many years or in combination with others. The growing fraction of the population that is either old or obese may further lower physical activity norms and requirements and substitute medical intervention for health, accelerating a trend toward cognitive impairment.

  17. Neotropical Amphibian Declines Affect Stream Ecosystem Properties

    Connelly, S.; Pringle, C. M.; Bixby, R. J.; Whiles, M. R.; Lips, K. R.; Brenes, R.; Colon-Gaud, J. C.; Kilham, S.; Hunte-Brown, M.


    Global declines of amphibians are well documented, yet effects of these dramatic losses on ecosystem structure and function are poorly understood. As part of a larger collaborative project, we compared two upland Panamanian streams. Both streams are biologically and geologically similar; however, one stream (Fortuna) has recently experienced almost complete extirpation of stream-dwelling frogs, while the other (Cope) still has intact populations. We experimentally excluded tadpoles from localized areas in each stream. We then compared chlorophyll a, algal community composition, ash-free dry mass (AFDM), inorganic matter, and insect assemblages in control and exclusion areas. Additionally, we sampled the natural substrate of both streams monthly for chlorophyll a, algal community composition, AFDM, and inorganic matter. At Cope, chlorophyll a, AFDM, and inorganic matter were greater in areas where tadpoles were excluded than in their presence. Numbers of dominant algal species (e.g., Nupela praecipua and Eunotia siolii) were greater in the exclusion versus control treatments. Monthly sampling of natural substrate indicated higher chlorophyll a and AFDM at Cope compared to Fortuna. Our data suggest that stream-dwelling anuran larvae have significant impacts on algal communities. These results also have implications for predicting the relevance of short-term experimental manipulations to long-term, whole-stream processes.

  18. Model Selection Through Sparse Maximum Likelihood Estimation

    Banerjee, Onureena; D'Aspremont, Alexandre


    We consider the problem of estimating the parameters of a Gaussian or binary distribution in such a way that the resulting undirected graphical model is sparse. Our approach is to solve a maximum likelihood problem with an added l_1-norm penalty term. The problem as formulated is convex but the memory requirements and complexity of existing interior point methods are prohibitive for problems with more than tens of nodes. We present two new algorithms for solving problems with at least a thousand nodes in the Gaussian case. Our first algorithm uses block coordinate descent, and can be interpreted as recursive l_1-norm penalized regression. Our second algorithm, based on Nesterov's first order method, yields a complexity estimate with a better dependence on problem size than existing interior point methods. Using a log determinant relaxation of the log partition function (Wainwright & Jordan (2006)), we show that these same algorithms can be used to solve an approximate sparse maximum likelihood problem for...

  19. Maximum-entropy description of animal movement.

    Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M


    We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.

  20. Pareto versus lognormal: a maximum entropy test.

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano


    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  1. Maximum Variance Hashing via Column Generation

    Lei Luo


    item search. Recently, a number of data-dependent methods have been developed, reflecting the great potential of learning for hashing. Inspired by the classic nonlinear dimensionality reduction algorithm—maximum variance unfolding, we propose a novel unsupervised hashing method, named maximum variance hashing, in this work. The idea is to maximize the total variance of the hash codes while preserving the local structure of the training data. To solve the derived optimization problem, we propose a column generation algorithm, which directly learns the binary-valued hash functions. We then extend it using anchor graphs to reduce the computational cost. Experiments on large-scale image datasets demonstrate that the proposed method outperforms state-of-the-art hashing methods in many cases.

  2. The Maximum Resource Bin Packing Problem

    Boyar, J.; Epstein, L.; Favrholdt, L.M.


    algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find......Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... the competitive ratio of various natural algorithms. We study the general versions of the problems as well as the parameterized versions where there is an upper bound of on the item sizes, for some integer k....

  3. Nonparametric Maximum Entropy Estimation on Information Diagrams

    Martin, Elliot A; Meinke, Alexander; Děchtěrenko, Filip; Davidsen, Jörn


    Maximum entropy estimation is of broad interest for inferring properties of systems across many different disciplines. In this work, we significantly extend a technique we previously introduced for estimating the maximum entropy of a set of random discrete variables when conditioning on bivariate mutual informations and univariate entropies. Specifically, we show how to apply the concept to continuous random variables and vastly expand the types of information-theoretic quantities one can condition on. This allows us to establish a number of significant advantages of our approach over existing ones. Not only does our method perform favorably in the undersampled regime, where existing methods fail, but it also can be dramatically less computationally expensive as the cardinality of the variables increases. In addition, we propose a nonparametric formulation of connected informations and give an illustrative example showing how this agrees with the existing parametric formulation in cases of interest. We furthe...

  4. Zipf's law, power laws and maximum entropy

    Visser, Matt


    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified.

  5. Zipf's law, power laws, and maximum entropy

    Visser, Matt


    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines - from astronomy to demographics to economics to linguistics to zoology, and even warfare. A recent model of random group formation [RGF] attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present article I argue that the cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified.

  6. Regions of constrained maximum likelihood parameter identifiability

    Lee, C.-H.; Herget, C. J.


    This paper considers the parameter identification problem of general discrete-time, nonlinear, multiple-input/multiple-output dynamic systems with Gaussian-white distributed measurement errors. Knowledge of the system parameterization is assumed to be known. Regions of constrained maximum likelihood (CML) parameter identifiability are established. A computation procedure employing interval arithmetic is proposed for finding explicit regions of parameter identifiability for the case of linear systems. It is shown that if the vector of true parameters is locally CML identifiable, then with probability one, the vector of true parameters is a unique maximal point of the maximum likelihood function in the region of parameter identifiability and the CML estimation sequence will converge to the true parameters.

  7. A Maximum Radius for Habitable Planets.

    Alibert, Yann


    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  8. A stochastic maximum principle via Malliavin calculus

    Øksendal, Bernt; Zhou, Xun Yu; Meyer-Brandis, Thilo


    This paper considers a controlled It\\^o-L\\'evy process where the information available to the controller is possibly less than the overall information. All the system coefficients and the objective performance functional are allowed to be random, possibly non-Markovian. Malliavin calculus is employed to derive a maximum principle for the optimal control of such a system where the adjoint process is explicitly expressed.

  9. Tissue radiation response with maximum Tsallis entropy.

    Sotolongo-Grau, O; Rodríguez-Pérez, D; Antoranz, J C; Sotolongo-Costa, Oscar


    The expression of survival factors for radiation damaged cells is currently based on probabilistic assumptions and experimentally fitted for each tumor, radiation, and conditions. Here, we show how the simplest of these radiobiological models can be derived from the maximum entropy principle of the classical Boltzmann-Gibbs expression. We extend this derivation using the Tsallis entropy and a cutoff hypothesis, motivated by clinical observations. The obtained expression shows a remarkable agreement with the experimental data found in the literature.

  10. Maximum Estrada Index of Bicyclic Graphs

    Wang, Long; Wang, Yi


    Let $G$ be a simple graph of order $n$, let $\\lambda_1(G),\\lambda_2(G),...,\\lambda_n(G)$ be the eigenvalues of the adjacency matrix of $G$. The Esrada index of $G$ is defined as $EE(G)=\\sum_{i=1}^{n}e^{\\lambda_i(G)}$. In this paper we determine the unique graph with maximum Estrada index among bicyclic graphs with fixed order.

  11. Maximum privacy without coherence, zero-error

    Leung, Debbie; Yu, Nengkun


    We study the possible difference between the quantum and the private capacities of a quantum channel in the zero-error setting. For a family of channels introduced by Leung et al. [Phys. Rev. Lett. 113, 030512 (2014)], we demonstrate an extreme difference: the zero-error quantum capacity is zero, whereas the zero-error private capacity is maximum given the quantum output dimension.

  12. Automatic maximum entropy spectral reconstruction in NMR.

    Mobli, Mehdi; Maciejewski, Mark W; Gryk, Michael R; Hoch, Jeffrey C


    Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system.

  13. Maximum entropy analysis of cosmic ray composition

    Nosek, Dalibor; Vícha, Jakub; Trávníček, Petr; Nosková, Jana


    We focus on the primary composition of cosmic rays with the highest energies that cause extensive air showers in the Earth's atmosphere. A way of examining the two lowest order moments of the sample distribution of the depth of shower maximum is presented. The aim is to show that useful information about the composition of the primary beam can be inferred with limited knowledge we have about processes underlying these observations. In order to describe how the moments of the depth of shower maximum depend on the type of primary particles and their energies, we utilize a superposition model. Using the principle of maximum entropy, we are able to determine what trends in the primary composition are consistent with the input data, while relying on a limited amount of information from shower physics. Some capabilities and limitations of the proposed method are discussed. In order to achieve a realistic description of the primary mass composition, we pay special attention to the choice of the parameters of the sup...

  14. A Maximum Resonant Set of Polyomino Graphs

    Zhang Heping


    Full Text Available A polyomino graph P is a connected finite subgraph of the infinite plane grid such that each finite face is surrounded by a regular square of side length one and each edge belongs to at least one square. A dimer covering of P corresponds to a perfect matching. Different dimer coverings can interact via an alternating cycle (or square with respect to them. A set of disjoint squares of P is a resonant set if P has a perfect matching M so that each one of those squares is M-alternating. In this paper, we show that if K is a maximum resonant set of P, then P − K has a unique perfect matching. We further prove that the maximum forcing number of a polyomino graph is equal to the cardinality of a maximum resonant set. This confirms a conjecture of Xu et al. [26]. We also show that if K is a maximal alternating set of P, then P − K has a unique perfect matching.

  15. The maximum rate of mammal evolution

    Evans, Alistair R.; Jones, David; Boyer, Alison G.; Brown, James H.; Costa, Daniel P.; Ernest, S. K. Morgan; Fitzgerald, Erich M. G.; Fortelius, Mikael; Gittleman, John L.; Hamilton, Marcus J.; Harding, Larisa E.; Lintulaakso, Kari; Lyons, S. Kathleen; Okie, Jordan G.; Saarinen, Juha J.; Sibly, Richard M.; Smith, Felisa A.; Stephens, Patrick R.; Theodor, Jessica M.; Uhen, Mark D.


    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.

  16. Minimal Length, Friedmann Equations and Maximum Density

    Awad, Adel


    Inspired by Jacobson's thermodynamic approach[gr-qc/9504004], Cai et al [hep-th/0501055,hep-th/0609128] have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar--Cai derivation [hep-th/0609128] of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure $p(\\rho,a)$ leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature $k$. As an example w...

  17. Maximum saliency bias in binocular fusion

    Lu, Yuhao; Stafford, Tom; Fox, Charles


    Subjective experience at any instant consists of a single ("unitary"), coherent interpretation of sense data rather than a "Bayesian blur" of alternatives. However, computation of Bayes-optimal actions has no role for unitary perception, instead being required to integrate over every possible action-percept pair to maximise expected utility. So what is the role of unitary coherent percepts, and how are they computed? Recent work provided objective evidence for non-Bayes-optimal, unitary coherent, perception and action in humans; and further suggested that the percept selected is not the maximum a posteriori percept but is instead affected by utility. The present study uses a binocular fusion task first to reproduce the same effect in a new domain, and second, to test multiple hypotheses about exactly how utility may affect the percept. After accounting for high experimental noise, it finds that both Bayes optimality (maximise expected utility) and the previously proposed maximum-utility hypothesis are outperformed in fitting the data by a modified maximum-salience hypothesis, using unsigned utility magnitudes in place of signed utilities in the bias function.

  18. The maximum rate of mammal evolution

    Evans, Alistair R.; Jones, David; Boyer, Alison G.; Brown, James H.; Costa, Daniel P.; Ernest, S. K. Morgan; Fitzgerald, Erich M. G.; Fortelius, Mikael; Gittleman, John L.; Hamilton, Marcus J.; Harding, Larisa E.; Lintulaakso, Kari; Lyons, S. Kathleen; Okie, Jordan G.; Saarinen, Juha J.; Sibly, Richard M.; Smith, Felisa A.; Stephens, Patrick R.; Theodor, Jessica M.; Uhen, Mark D.


    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous–Paleogene (K–Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes. PMID:22308461

  19. Maximum-biomass prediction of homofermentative Lactobacillus.

    Cui, Shumao; Zhao, Jianxin; Liu, Xiaoming; Chen, Yong Q; Zhang, Hao; Chen, Wei


    Fed-batch and pH-controlled cultures have been widely used for industrial production of probiotics. The aim of this study was to systematically investigate the relationship between the maximum biomass of different homofermentative Lactobacillus and lactate accumulation, and to develop a prediction equation for the maximum biomass concentration in such cultures. The accumulation of the end products and the depletion of nutrients by various strains were evaluated. In addition, the minimum inhibitory concentrations (MICs) of acid anions for various strains at pH 7.0 were examined. The lactate concentration at the point of complete inhibition was not significantly different from the MIC of lactate for all of the strains, although the inhibition mechanism of lactate and acetate on Lactobacillus rhamnosus was different from the other strains which were inhibited by the osmotic pressure caused by acid anions at pH 7.0. When the lactate concentration accumulated to the MIC, the strains stopped growing. The maximum biomass was closely related to the biomass yield per unit of lactate produced (YX/P) and the MIC (C) of lactate for different homofermentative Lactobacillus. Based on the experimental data obtained using different homofermentative Lactobacillus, a prediction equation was established as follows: Xmax - X0 = (0.59 ± 0.02)·YX/P·C.

  20. The maximum rate of mammal evolution.

    Evans, Alistair R; Jones, David; Boyer, Alison G; Brown, James H; Costa, Daniel P; Ernest, S K Morgan; Fitzgerald, Erich M G; Fortelius, Mikael; Gittleman, John L; Hamilton, Marcus J; Harding, Larisa E; Lintulaakso, Kari; Lyons, S Kathleen; Okie, Jordan G; Saarinen, Juha J; Sibly, Richard M; Smith, Felisa A; Stephens, Patrick R; Theodor, Jessica M; Uhen, Mark D


    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.

  1. A Realization of Theoretical Maximum Performance in IPSec on Gigabit Ethernet

    Onuki, Atsushi; Takeuchi, Kiyofumi; Inada, Toru; Tokiniwa, Yasuhisa; Ushirozawa, Shinobu

    This paper describes “IPSec(IP Security) VPN system" and how it attains a theoretical maximum performance on Gigabit Ethernet. The Conventional System is implemented by software. However, the system has several bottlenecks which must be overcome to realize a theoretical maximum performance on Gigabit Ethernet. Thus, we newly propose IPSec VPN System with the FPGA(Field Programmable Gate Array) based hardware architecture, which transmits a packet by the pipe-lined flow processing and has 6 parallel structure of encryption and authentication engines. We show that our system attains the theoretical maximum performance in the short packet which is difficult to realize until now.

  2. An extensive optical study of V2491 Cyg (Nova Cyg 2008 N.2), from maximum brightness to return to quiescence

    Munari, U; Dallaporta, S; Cherini, G; Valisa, P; Tomasella, L


    The photometric and spectroscopic evolution of the He/N and very fast Nova Cyg 2008 N2 (V2491 Cyg) is studied in detail. A primary maximum was reached at V=7.45 +/-0.05 on April 11.37 (+/-0.1) 2008 UT, followed by a smooth decline characterized by t2(V)=4.8 days, and then a second maximum was attained at V=9.49 +/-0.03, 14.5 days after the primary one. This is the only third nova to have displayed a secondary maximum, after V2362 Cyg and V1493 Aql. The development and energetics of the secondary maximum is studied in detail. The smooth decline that followed was accurately monitored until day +144 when the nova was 8.6 mag fainter than maximum brightness, well into its nebular phase, with its line and continuum emissivity declining as t-3. The reddening affecting the nova was E(B-V)=0.23 +/-0.01, and the distance of 14 kpc places the nova at a height above the galactic plane of 1.1 kpc, larger than typical for He/N novae. The expansion velocity of the bulk of ejecta was 2000 km/sec, with complex emission profi...

  3. The lognormal handwriter: learning, performing and declining.

    Réjean ePlamondon


    Full Text Available The generation of handwriting is a complex neuromotor skill requiring the interaction of many cognitive processes. It aims at producing a message to be imprinted as an ink trace left on a writing medium. The generated trajectory of the pen tip is made up of strokes superimposed over time. The Kinematic Theory of rapid human movements and its family of lognormal models provide analytical representations of these strokes, often considered as the basic unit of handwriting. This paradigm has not only been experimentally confirmed in numerous predictive and physiologically significant tests but it has also been shown to be the ideal mathematical description for the impulse response of a neuromuscular system. This latter demonstration suggests that the lognormality of the velocity patterns can be interpreted as reflecting the behaviour of subjects who are in perfect control of their movements. To illustrate this interpretation, we present a short overview of the main concepts behind the Kinematic Theory and briefly describe how its models can be exploited, using various software tools, to investigate these ideal lognormal behaviors. We emphasize that the parameters extracted during various tasks can be used to analyze some underlying processes associated with their realization. To investigate the operational convergence hypothesis, we report on two original studies. First, we focus on the early steps of the motor learning process as seen as a converging behaviour toward the production of more precise lognormal patterns as young children practicing handwriting start to become more fluent writers. Second, we illustrate how aging affects handwriting by pointing out the increasing departure from the ideal lognormal behaviour as the control of the fine motricity begins to decline. Overall, the paper highlights this developmental process of merging toward a lognormal behaviour with learning, mastering this behaviour to succeed in performing a given task

  4. Conifer Decline and Mortality in Siberia

    Kharuk, V.; Im, S.; Ranson, K.


    "Dark needle conifer" (DNC: Abies sibirica, Pinus sibirica and Picea obovata) decline and mortality increase were documented in Russia during recent decades. Here we analyzed causes and scale of Siberian pine and fir mortality in Altai-Sayan and Baikal Lake Regions and West Siberian Plane based on in situdata and remote sensing (QuickBird, Landsat, GRACE). Geographically, mortality began on the margins of the DNC range (i.e., within the forest-steppe and conifer-broadleaf ecotones) and on terrain features with maximal water stress risk (narrow-shaped hilltops, convex steep south facing slopes, shallow well-drained soils). Within ridges, mortality occurred mainly along mountain passes, where stands faced drying winds. Regularly mortality was observed to decrease with elevation increase with the exception of Baikal Lake Mountains, where it was minimal near the lake shore and increased with elevation (up to about 1000 m a.s.l.). Siberian pine and fir mortality followed a drying trend with consecutive droughts since the 1980s. Dendrochronology analysis showed that mortality was correlated with vapor pressure deficit increase, drought index, soil moisture decrease and occurrence of late frosts. In Baikal region Siberian pine mortality correlated with Baikal watershed meteorological variables. An impact of previous year climate conditions on the current growth was found (r2 = 0.6). Thus, water-stressed trees became sensitive to bark beetles and fungi impact (including Polygraphus proximus and Heterobasidion annosum). At present, an increase in mortality is observed within the majority of DNC range. Results obtained also showed a primary role of water stress in that phenomenon with a secondary role of bark beetles and fungi attacks. In future climate with increased drought severity and frequency Siberian pine and fir will partly disappear from its current range, and will be substituted by drought-tolerant species (e.g., Pinus silvestris, Larix sibirica).

  5. Local and global influences on population declines of coastal waders: Purple Sandpiper Calidris maritima numbers in the Moray Firth, Scotland

    Summers, Ron W.; Foster, Simon; Swann, Bob; Etheridge, Brian


    Declines in numbers by several wader species in Britain have been linked to climate change, but the mechanism for the declines has rarely been explored. Britain lies at the northern end of the East Atlantic Flyway, and supports 1.3 million out of the Flyway's 8.5 million coastal waders (Charadrii) in winter and the Purple Sandpiper is one of the species whose numbers have declined. Here, we examine the dynamics of the decline as observed in the Moray Firth, northeast Scotland, investigating whether the decline was due to poorer apparent survival (return rate) or poorer recruitment of young birds. The maximum number in the Moray Firth declined from 860 in 1987/88 to 236 in 2006/07, with some increase during winters 2007/08 and 2008/09. At the three main high-tide roosts (Balintore, Lossiemouth and Buckie) the maximum combined number declined from 574 to 90. Changes in survival and recruitment (percentage of first-year birds) were examined at these roosts from captured samples, which were ringed and recaptured. There were no significant changes between winters in survival rates, nor were there differences between the survival rates of age groups (first-year and adult) or bill size groups, which represented birds of different sex and breeding origin. Annual survival estimates for the three roosts ranged from 72 to 77%. The percentage of first-year birds varied among roosts and years; the lowest values were during the late 1980s/early 1990s and early 2000s. A free-running population model incorporating varying percentages of first-year birds and constant mortality for each roost provided a plausible explanation for the decline. Although modelled numbers followed the observed pattern, a discrepancy in one year was carried forward in subsequent years, so that the fit with the observed numbers was parallel rather than similar. However, it seems that the decline in numbers was largely due to poorer recruitment. We discuss whether breeding success had declined, whether the

  6. The Reddening-Free Decline Rate Versus Luminosity Relationship for Type Ia Supernovae

    Phillips, M M; Suntzeff, N B; Schommer, R A; Hamuy, M; Maza, J


    We develop a method for estimating the host galaxy dust extinction for type Ia supernovae based on an observational coincidence first noted by Lira (1995), who found that the B-V evolution during the period from 30-90 days after V maximum is remarkably similar for all events, regardless of light curve shape. This fact is used to calibrate the dependence of the B(max)-V(max) and V(max)-I(max) colors on the light curve decline rate parameter delta-m15, which can, in turn, be used to separately estimate the host galaxy extinction. Using these methods to eliminate the effects of reddening, we reexamine the functional form of the decline rate versus luminosity relationship and provide an updated estimate of the Hubble constant of Ho = 63.3 +- 2.2(internal) +- 3.5(external) km/s/Mpc.

  7. Accelerated decline in lung function in smoking women with airway obstruction: SAPALDIA 2 cohort study

    Zemp Elisabeth


    Full Text Available Abstract Background The aim was to determine if effects from smoking on lung function measured over 11 years differ between men and women. Methods In a prospective population based cohort study (Swiss Study on Air Pollution and Lung Diseases in Adults current smokers in 1991 (18 – 60 yrs were reassessed in 2002 (n = 1792. Multiple linear regression was used to estimate effects from pack-years of cigarettes smoked to 1991 and mean packs of cigarettes smoked per day between 1991 and 2002 on change in lung volume and flows over the 11 years. Results In both sexes, packs smoked between assessments were related to lung function decline but pack-years smoked before 1991 were not. Mean annual decline in FEV1 was -10.4 mL(95%CI -15.3, -5.5 per pack per day between assessments in men and -13.8 mL(95%CI-19.5,-8.1 in women. Decline per pack per day between 1991 and 2002 was lower in women who smoked in 1991 but quit before 2002 compared to persistent smokers (-6.4 vs -11.6 mL, p = 0.05 but this was not seen in men (-14.3 vs -8.8 mL p = 0.49. Smoking related decline was accelerated in men and women with airway obstruction, particularly in women where decline in FEV1 was three fold higher in participants with FEV1/FVC Conclusion There are differences in effects from smoking on lung function between men and women. Lung function recovers faster in women quitters than in men. Women current smokers with airway obstruction experience a greater smoking related decline in lung function than men.

  8. Declines in swimming performance with age: a longitudinal study of Masters swimming champions

    Rubin RT


    Full Text Available Robert T Rubin,1,2 Sonia Lin,3 Amy Curtis,4 Daniel Auerbach,5 Charlene Win6 1Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; 2UCLA Bruin Masters Swim Club, Los Angeles, CA, USA; 3Saint Louis University School of Medicine, Saint Louis, MO, USA; 4Indiana University School of Medicine, Indianapolis, IN, USA; 5University of California, Berkeley, CA, USA; 6Loyola Marymount University, Los Angeles, CA, USA Introduction: Because of its many participants and thorough records, competitive Masters swimming offers a rich data source for determining the rate of physical decline associated with aging in physically fit individuals. The decline in performance among national champion swimmers, both men and women and in short and long swims, is linear, at about 0.6% per year up to age 70–75, after which it accelerates in quadratic fashion. These conclusions are based primarily on cross-sectional studies, and little is known about individual performance declines with aging. Herein we present performance profiles of 19 male and 26 female national and international champion Masters swimmers, ages 25 to 96 years, participating in competitions for an average of 23 years. Methods and results: Swimmers’ longitudinal data were compared with the fastest times of world record holders across ages 35–100 years by two regression methods. Neither method proved to accurately model this data set: compared with the rates of decline estimated from the world record data, which represent the best recorded times at given ages, there was bias toward shallower rates of performance decline in the longitudinal data, likely owing to a practice effect in some swimmers as they began their Masters programs. In swimmers’ later years, once maximum performance had been achieved, individual profiles followed the decline represented in the world records, and a few swimmers became the world record holders. In some instances

  9. Can the Maximum Power Principle predict Effective Conductivities of a Confined Aquifer? A Lab Experiment

    Westhoff, M.; Erpicum, S.; Archambeau, P.; Pirotton, M.; Zehe, E.; Dewals, B.


    Power can be performed by a system driven by a potential difference. From a given potential difference, the power that can be subtracted is constraint by the Carnot limit, which follows from the first and second laws of thermodynamics. If the system is such that the flux producing power (with power being the flux times its driving potential difference) also influences the potential difference, a maximum in power can be obtained as a result of the trade-off between the flux and the potential difference. This is referred to as the maximum power principle. It has already been shown that the atmosphere operates close to this maximum power limit when it comes to heat transport from the Equator to the poles, or vertically, from the surface to the atmospheric boundary layer. To reach this state of maximum power, the effective thermal conductivity of the atmosphere is adapted by the creation of convection cells. The aim of this study is to test if the soil's effective hydraulic conductivity also adapts in such a way that it produces maximum power. However, the soil's hydraulic conductivity adapts differently; for example by the creation of preferential flow paths. Here, this process is simulated in a lab experiment, which focuses on preferential flow paths created by piping. In the lab, we created a hydrological analogue to the atmospheric model dealing with heat transport between Equator and poles, with the aim to test if the effective hydraulic conductivity of the sand bed can be predicted with the maximum power principle. The experimental setup consists of two freely draining reservoir connected with each other by a confined aquifer. By adding water to only one reservoir, a potential difference will build up until a steady state is reached. The results will indicate whether the maximum power principle does apply for groundwater flow and how it should be applied. Because of the different way of adaptation of flow conductivity, the results differ from that of the

  10. Plankton communities and summertime declines in algal abundance associated with low dissolved oxygen in the Tualatin River, Oregon

    Carpenter, Kurt D.; Rounds, Stewart A.


    Phytoplankton populations in the Tualatin River in northwestern Oregon are an important component of the dissolved oxygen (DO) budget of the river and are critical for maintaining DO levels in summer. During the low-flow summer period, sufficient nutrients and a long residence time typically combine with ample sunshine and warm water to fuel blooms of cryptophyte algae, diatoms, green and blue-green algae in the low-gradient, slow-moving reservoir reach of the lower river. Algae in the Tualatin River generally drift with the water rather than attach to the river bottom as a result of moderate water depths, slightly elevated turbidity caused by suspended colloidal material, and dominance of silty substrates. Growth of algae occurs as if on a “conveyor belt” of streamflow, a dynamic system that is continually refreshed with inflowing water. Transit through the system can take as long as 2 weeks during the summer low-flow period. Photosynthetic production of DO during algal blooms is important in offsetting oxygen consumption at the sediment-water interface caused by the decomposition of organic matter from primarily terrestrial sources, and the absence of photosynthesis can lead to low DO concentrations that can harm aquatic life. The periods with the lowest DO concentrations in recent years (since 2003) typically occur in August following a decline in algal abundance and activity, when DO concentrations often decrease to less than State standards for extended periods (nearly 80 days). Since 2003, algal populations have tended to be smaller and algal blooms have terminated earlier compared to conditions in the 1990s, leading to more frequent declines in DO to levels that do not meet State standards. This study was developed to document the current abundance and species composition of phytoplankton in the Tualatin River, identify the possible causes of the general decline in algae, and evaluate hypotheses to explain why algal blooms diminish in midsummer. Plankton

  11. Maximum power operation of interacting molecular motors

    Golubeva, Natalia; Imparato, Alberto


    We study the mechanical and thermodynamic properties of different traffic models for kinesin which are relevant in biological and experimental contexts. We find that motor-motor interactions play a fundamental role by enhancing the thermodynamic efficiency at maximum power of the motors......, as compared to the non-interacting system, in a wide range of biologically compatible scenarios. We furthermore consider the case where the motor-motor interaction directly affects the internal chemical cycle and investigate the effect on the system dynamics and thermodynamics....

  12. Maximum a posteriori decoder for digital communications

    Altes, Richard A. (Inventor)


    A system and method for decoding by identification of the most likely phase coded signal corresponding to received data. The present invention has particular application to communication with signals that experience spurious random phase perturbations. The generalized estimator-correlator uses a maximum a posteriori (MAP) estimator to generate phase estimates for correlation with incoming data samples and for correlation with mean phases indicative of unique hypothesized signals. The result is a MAP likelihood statistic for each hypothesized transmission, wherein the highest value statistic identifies the transmitted signal.

  13. Kernel-based Maximum Entropy Clustering

    JIANG Wei; QU Jiao; LI Benxi


    With the development of Support Vector Machine (SVM),the "kernel method" has been studied in a general way.In this paper,we present a novel Kernel-based Maximum Entropy Clustering algorithm (KMEC).By using mercer kernel functions,the proposed algorithm is firstly map the data from their original space to high dimensional space where the data are expected to be more separable,then perform MEC clustering in the feature space.The experimental results show that the proposed method has better performance in the non-hyperspherical and complex data structure.

  14. The sun and heliosphere at solar maximum.

    Smith, E J; Marsden, R G; Balogh, A; Gloeckler, G; Geiss, J; McComas, D J; McKibben, R B; MacDowall, R J; Lanzerotti, L J; Krupp, N; Krueger, H; Landgraf, M


    Recent Ulysses observations from the Sun's equator to the poles reveal fundamental properties of the three-dimensional heliosphere at the maximum in solar activity. The heliospheric magnetic field originates from a magnetic dipole oriented nearly perpendicular to, instead of nearly parallel to, the Sun's rotation axis. Magnetic fields, solar wind, and energetic charged particles from low-latitude sources reach all latitudes, including the polar caps. The very fast high-latitude wind and polar coronal holes disappear and reappear together. Solar wind speed continues to be inversely correlated with coronal temperature. The cosmic ray flux is reduced symmetrically at all latitudes.

  15. Conductivity maximum in a charged colloidal suspension

    Bastea, S


    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  16. Maximum entropy signal restoration with linear programming

    Mastin, G.A.; Hanson, R.J.


    Dantzig's bounded-variable method is used to express the maximum entropy restoration problem as a linear programming problem. This is done by approximating the nonlinear objective function with piecewise linear segments, then bounding the variables as a function of the number of segments used. The use of a linear programming approach allows equality constraints found in the traditional Lagrange multiplier method to be relaxed. A robust revised simplex algorithm is used to implement the restoration. Experimental results from 128- and 512-point signal restorations are presented.




    Full Text Available Ship squat is a combined effect of ship’s draft and trim increase due to ship motion in limited navigation conditions. Over time, researchers conducted tests on models and ships to find a mathematical formula that can define squat. Various forms of calculating squat can be found in the literature. Among those most commonly used are of Barrass, Millward, Eryuzlu or ICORELS. This paper presents a comparison between the squat formulas to see the differences between them and which one provides the most satisfactory results. In this respect a cargo ship at different speeds was considered as a model for maximum squat calculations in canal navigation conditions.

  18. Multi-Channel Maximum Likelihood Pitch Estimation

    Christensen, Mads Græsbøll


    In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristics....... This essentially means that the model allows for different conditions in the various channels, like different signal-to-noise ratios, microphone characteristics and reverberation. Moreover, the method does not assume that a certain array structure is used but rather relies on a more general model and is hence...

  19. Maximum entropy PDF projection: A review

    Baggenstoss, Paul M.


    We review maximum entropy (MaxEnt) PDF projection, a method with wide potential applications in statistical inference. The method constructs a sampling distribution for a high-dimensional vector x based on knowing the sampling distribution p(z) of a lower-dimensional feature z = T (x). Under mild conditions, the distribution p(x) having highest possible entropy among all distributions consistent with p(z) may be readily found. Furthermore, the MaxEnt p(x) may be sampled, making the approach useful in Monte Carlo methods. We review the theorem and present a case study in model order selection and classification for handwritten character recognition.

  20. CORA: Emission Line Fitting with Maximum Likelihood

    Ness, Jan-Uwe; Wichmann, Rainer


    CORA analyzes emission line spectra with low count numbers and fits them to a line using the maximum likelihood technique. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise, the software derives the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. CORA has been applied to an X-ray spectrum with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory.

  1. Dynamical maximum entropy approach to flocking

    Cavagna, Andrea; Giardina, Irene; Ginelli, Francesco; Mora, Thierry; Piovani, Duccio; Tavarone, Raffaele; Walczak, Aleksandra M.


    We derive a new method to infer from data the out-of-equilibrium alignment dynamics of collectively moving animal groups, by considering the maximum entropy model distribution consistent with temporal and spatial correlations of flight direction. When bird neighborhoods evolve rapidly, this dynamical inference correctly learns the parameters of the model, while a static one relying only on the spatial correlations fails. When neighbors change slowly and the detailed balance is satisfied, we recover the static procedure. We demonstrate the validity of the method on simulated data. The approach is applicable to other systems of active matter.

  2. Maximum Temperature Detection System for Integrated Circuits

    Frankiewicz, Maciej; Kos, Andrzej


    The paper describes structure and measurement results of the system detecting present maximum temperature on the surface of an integrated circuit. The system consists of the set of proportional to absolute temperature sensors, temperature processing path and a digital part designed in VHDL. Analogue parts of the circuit where designed with full-custom technique. The system is a part of temperature-controlled oscillator circuit - a power management system based on dynamic frequency scaling method. The oscillator cooperates with microprocessor dedicated for thermal experiments. The whole system is implemented in UMC CMOS 0.18 μm (1.8 V) technology.

  3. Zipf's law and maximum sustainable growth

    Malevergne, Y; Sornette, D


    Zipf's law states that the number of firms with size greater than S is inversely proportional to S. Most explanations start with Gibrat's rule of proportional growth but require additional constraints. We show that Gibrat's rule, at all firm levels, yields Zipf's law under a balance condition between the effective growth rate of incumbent firms (which includes their possible demise) and the growth rate of investments in entrant firms. Remarkably, Zipf's law is the signature of the long-term optimal allocation of resources that ensures the maximum sustainable growth rate of an economy.

  4. Distribution of phytoplankton groups within the deep chlorophyll maximum

    Latasa, Mikel


    The fine vertical distribution of phytoplankton groups within the deep chlorophyll maximum (DCM) was studied in the NE Atlantic during summer stratification. A simple but unconventional sampling strategy allowed examining the vertical structure with ca. 2 m resolution. The distribution of Prochlorococcus, Synechococcus, chlorophytes, pelagophytes, small prymnesiophytes, coccolithophores, diatoms, and dinoflagellates was investigated with a combination of pigment-markers, flow cytometry and optical and FISH microscopy. All groups presented minimum abundances at the surface and a maximum in the DCM layer. The cell distribution was not vertically symmetrical around the DCM peak and cells tended to accumulate in the upper part of the DCM layer. The more symmetrical distribution of chlorophyll than cells around the DCM peak was due to the increase of pigment per cell with depth. We found a vertical alignment of phytoplankton groups within the DCM layer indicating preferences for different ecological niches in a layer with strong gradients of light and nutrients. Prochlorococcus occupied the shallowest and diatoms the deepest layers. Dinoflagellates, Synechococcus and small prymnesiophytes preferred shallow DCM layers, and coccolithophores, chlorophytes and pelagophytes showed a preference for deep layers. Cell size within groups changed with depth in a pattern related to their mean size: the cell volume of the smallest group increased the most with depth while the cell volume of the largest group decreased the most. The vertical alignment of phytoplankton groups confirms that the DCM is not a homogeneous entity and indicates groups’ preferences for different ecological niches within this layer.

  5. Exploring the Constrained Maximum Edge-weight Connected Graph Problem

    Zhen-ping Li; Shi-hua Zhang; Xiang-Sun Zhang; Luo-nan Chen


    Given an edge weighted graph,the maximum edge-weight connected graph (MECG) is a connected subgraph with a given number of edges and the maximal weight sum.Here we study a special case,i.e.the Constrained Maximum Edge-Weight Connected Graph problem (CMECG),which is an MECG whose candidate subgraphs must include a given set of k edges,then also called the k-CMECG.We formulate the k-CMECG into an integer linear programming model based on the network flow problem.The k-CMECG is proved to be NP-hard.For the special case 1-CMECG,we propose an exact algorithm and a heuristic algorithm respectively.We also propose a heuristic algorithm for the k-CMECG problem.Some simulations have been done to analyze the quality of these algorithms.Moreover,we show that the algorithm for 1-CMECG problem can lead to the solution of the general MECG problem.

  6. What distinguishes passive recipients from active decliners of sales flyers

    Jensen, Birger Boutrup; Orquin, Jacob Lund; Bech-Larsen, Tino


    While sales flyer ad spending in Denmark has increased over the last decade ,the proportion of consumers declining to receive such flyers has been ever-increasing. To address this paradox, attitudinal and behavioural factors distinguishing passive recipients from active decliners of sales flyers...... on the Internet.To reach the decliners, retailers could focus on the possibilities of the Internet, but to stop the trend of escalating numbers of decliners, retailers will have to address the perceived inconvenience and uselessness of sales flyers....

  7. Fast renal decline to end-stage renal disease

    Krolewski, Andrzej S.; Skupien, Jan; Rossing, Peter


    A new model of diabetic nephropathy in type 1 diabetes emerged from our studies of Joslin Clinic patients. The dominant feature is progressive renal decline, not albuminuria. This decline is a unidirectional process commencing while patients have normal renal function and, in the majority, progre...... for markers predictive of the rate of renal decline yield findings that may make detection of fast decliners feasible. Identifying such patients will be the foundation for developing effective individualized methods to prevent or delay onset of ESRD in diabetes....... progression as rate of eGFR declines > 5 ml/min/year, a value exceeded by 80% of patients in Joslin's type 1 diabetes ESRD cohort. The extraordinary range of slopes within the rapid progression category prompted us to partition it into “very fast,” “fast” and “moderate” decline. We showed, for the first time......, that very fast and fast decline from normal eGFR to ESRD within 2 to 10 years constitutes 50% of the Joslin cohort. In this review we present data about frequency of fast decliners in both diabetes types, survey some mechanisms underlying fast renal decline, discuss methods of identifying patients at risk...

  8. The Decline in Black Teenage Employment: 1950-1970

    Cogan, John F.


    This paper examines the causes of the decline in black male teenage employment from 1950 to 1970. During this period, the employment-to-population ratio of black youth (age 16-19) declined from 46.8 percent to 27 percent. The white teenage employment ratio, in contrast, remained constant. The primary source of the decline is traced to the virtual demise of the market for low-skilled agricultural labor. All of the black teenage employment decline during this period occurs in the South. The emp...

  9. Evaluating the Association between Diabetes, Cognitive Decline and Dementia

    Omorogieva Ojo


    Full Text Available The aim of this article is to review the association between diabetes mellitus, cognitive decline and dementia, including the effects of cognitive decline and dementia on self management of diabetes. This is a literature review of primary research articles. A number of contemporary research articles that met the inclusion criteria were selected for this review paper. These articles were selected using a number of search strategies and electronic databases, such as EBSCOhost Research and SwetsWise databases. The duration of diabetes, glycated haemoglobin levels and glycaemic fluctuations were associated with cognitive decline and dementia. Similarly, hypoglycaemia was significantly related to increased risk of developing cognitive decline and dementia. Furthermore, cognitive decline and dementia were associated with poorer diabetes management. There is evidence of the association between diabetes, cognitive decline and dementia including the shared pathogenesis between diabetes and Alzheimer’s disease. In addition, the self management of diabetes is affected by dementia and cognitive decline. It could be suggested that the association between diabetes and dementia is bidirectional with the potential to proceed to a vicious cycle. Further studies are needed in order to fully establish the relationship between diabetes, cognitive decline and dementia. Patients who have diabetes and dementia could benefit from structured education strategies, which should involve empowerment programmes and lifestyle changes. The detection of cognitive decline should highlight the need for education strategies.

  10. Plankton communities and summertime declines in algal abundance associated with low dissolved oxygen in the Tualatin River, Oregon

    Carpenter, Kurt D.; Rounds, Stewart A.


    Phytoplankton populations in the Tualatin River in northwestern Oregon are an important component of the dissolved oxygen (DO) budget of the river and are critical for maintaining DO levels in summer. During the low-flow summer period, sufficient nutrients and a long residence time typically combine with ample sunshine and warm water to fuel blooms of cryptophyte algae, diatoms, green and blue-green algae in the low-gradient, slow-moving reservoir reach of the lower river. Algae in the Tualatin River generally drift with the water rather than attach to the river bottom as a result of moderate water depths, slightly elevated turbidity caused by suspended colloidal material, and dominance of silty substrates. Growth of algae occurs as if on a “conveyor belt” of streamflow, a dynamic system that is continually refreshed with inflowing water. Transit through the system can take as long as 2 weeks during the summer low-flow period. Photosynthetic production of DO during algal blooms is important in offsetting oxygen consumption at the sediment-water interface caused by the decomposition of organic matter from primarily terrestrial sources, and the absence of photosynthesis can lead to low DO concentrations that can harm aquatic life. The periods with the lowest DO concentrations in recent years (since 2003) typically occur in August following a decline in algal abundance and activity, when DO concentrations often decrease to less than State standards for extended periods (nearly 80 days). Since 2003, algal populations have tended to be smaller and algal blooms have terminated earlier compared to conditions in the 1990s, leading to more frequent declines in DO to levels that do not meet State standards. This study was developed to document the current abundance and species composition of phytoplankton in the Tualatin River, identify the possible causes of the general decline in algae, and evaluate hypotheses to explain why algal blooms diminish in midsummer. Plankton

  11. Post-glacial ocean acidification and the decline of reefal microbial crusts

    Riding, R.; Liang, L.; Braga, J.


    Data from Pacific, Indian Ocean and Caribbean coral reefs indicate marked Late Pleistocene to Holocene decline in the maximum thickness of microbial carbonate crusts in reef cavities. Using estimated values of pH, temperature, CO2, and ionic composition, we calculated calcite saturation ratio (Ωcalcite) of tropical surface seawater for the past 16 Ka. This shows a declining trend of Ωcalcite, paralleling that of reefal microbial crust thickness. We suggest that thinning of reefal microbial crusts could reflect decrease in seawater carbonate saturation due to ocean acidification in response to deglacial CO2 increase. Previously, decline in reefal microbial crusts, for example at Tahiti in the Pacific Ocean, has mainly been attributed to changes in nutrient supply associated with ocean upwelling and/or terrestrial run-off. Ocean acidification does not preclude such effects on microbial crust development produced by localized changes, but two features in particular are consistent with a global link with carbonate saturation state. Firstly, post-glacial decline in reefal microbial crust thickness affected tropical coral reefs in several oceans. Secondly, seawater carbonate saturation is a major long-term control on microbial carbonate abundance; microbially-induced biocalcification requires elevated seawater saturation for CaCO3 minerals and can be expected to fluctuate with carbonate saturation. In addition to compiling published crust thickness data, we measured thicknesses of microbial carbonate crusts in cavities in Tahiti reefs sampled by Integrated Ocean Drilling Program coring in 2005. This indicates halving of maximum crust thickness, during the same period as steep decline in mean-ocean calcite saturation, near the Pleistocene-Holocene transition. Reefal microbial crusts have been common since skeletal reefs became widespread during the Ordovician Period, 475 Ma ago. The habitat for cryptic crusts expanded as scleractinian corals developed cavernous

  12. Maximum Spin of Black Holes Driving Jets

    Benson, Andrew J


    Unbounded outflows in the form of highly collimated jets and broad winds appear to be a ubiquitous feature of accreting black hole systems. The most powerful jets are thought to derive a significant fraction, if not the majority, of their power from the rotational energy of the black hole. Whatever the precise mechanism that causes them, these jets must therefore exert a braking torque on the black hole. We calculate the spin-up function for an accreting black hole, accounting for this braking torque. We find that the predicted black hole spin-up function depends only on the black hole spin and dimensionless parameters describing the accretion flow. Using recent relativistic magnetohydrodynamical numerical simulation results to calibrate the efficiency of angular momentum transfer in the flow, we find that an ADAF flow will spin a black hole up (or down) to an equilibrium value of about 96% of the maximal spin value in the absence of jets. Combining our ADAF system with a simple model for jet power, we demons...

  13. Accurate structural correlations from maximum likelihood superpositions.

    Douglas L Theobald


    Full Text Available The cores of globular proteins are densely packed, resulting in complicated networks of structural interactions. These interactions in turn give rise to dynamic structural correlations over a wide range of time scales. Accurate analysis of these complex correlations is crucial for understanding biomolecular mechanisms and for relating structure to function. Here we report a highly accurate technique for inferring the major modes of structural correlation in macromolecules using likelihood-based statistical analysis of sets of structures. This method is generally applicable to any ensemble of related molecules, including families of nuclear magnetic resonance (NMR models, different crystal forms of a protein, and structural alignments of homologous proteins, as well as molecular dynamics trajectories. Dominant modes of structural correlation are determined using principal components analysis (PCA of the maximum likelihood estimate of the correlation matrix. The correlations we identify are inherently independent of the statistical uncertainty and dynamic heterogeneity associated with the structural coordinates. We additionally present an easily interpretable method ("PCA plots" for displaying these positional correlations by color-coding them onto a macromolecular structure. Maximum likelihood PCA of structural superpositions, and the structural PCA plots that illustrate the results, will facilitate the accurate determination of dynamic structural correlations analyzed in diverse fields of structural biology.

  14. Maximum entropy production and the fluctuation theorem

    Dewar, R C [Unite EPHYSE, INRA Centre de Bordeaux-Aquitaine, BP 81, 33883 Villenave d' Ornon Cedex (France)


    Recently the author used an information theoretical formulation of non-equilibrium statistical mechanics (MaxEnt) to derive the fluctuation theorem (FT) concerning the probability of second law violating phase-space paths. A less rigorous argument leading to the variational principle of maximum entropy production (MEP) was also given. Here a more rigorous and general mathematical derivation of MEP from MaxEnt is presented, and the relationship between MEP and the FT is thereby clarified. Specifically, it is shown that the FT allows a general orthogonality property of maximum information entropy to be extended to entropy production itself, from which MEP then follows. The new derivation highlights MEP and the FT as generic properties of MaxEnt probability distributions involving anti-symmetric constraints, independently of any physical interpretation. Physically, MEP applies to the entropy production of those macroscopic fluxes that are free to vary under the imposed constraints, and corresponds to selection of the most probable macroscopic flux configuration. In special cases MaxEnt also leads to various upper bound transport principles. The relationship between MaxEnt and previous theories of irreversible processes due to Onsager, Prigogine and Ziegler is also clarified in the light of these results. (letter to the editor)

  15. Thermodynamic hardness and the maximum hardness principle

    Franco-Pérez, Marco; Gázquez, José L.; Ayers, Paul W.; Vela, Alberto


    An alternative definition of hardness (called the thermodynamic hardness) within the grand canonical ensemble formalism is proposed in terms of the partial derivative of the electronic chemical potential with respect to the thermodynamic chemical potential of the reservoir, keeping the temperature and the external potential constant. This temperature dependent definition may be interpreted as a measure of the propensity of a system to go through a charge transfer process when it interacts with other species, and thus it keeps the philosophy of the original definition. When the derivative is expressed in terms of the three-state ensemble model, in the regime of low temperatures and up to temperatures of chemical interest, one finds that for zero fractional charge, the thermodynamic hardness is proportional to T-1(I -A ) , where I is the first ionization potential, A is the electron affinity, and T is the temperature. However, the thermodynamic hardness is nearly zero when the fractional charge is different from zero. Thus, through the present definition, one avoids the presence of the Dirac delta function. We show that the chemical hardness defined in this way provides meaningful and discernible information about the hardness properties of a chemical species exhibiting integer or a fractional average number of electrons, and this analysis allowed us to establish a link between the maximum possible value of the hardness here defined, with the minimum softness principle, showing that both principles are related to minimum fractional charge and maximum stability conditions.

  16. Maximum Likelihood Analysis in the PEN Experiment

    Lehman, Martin


    The experimental determination of the π+ -->e+ ν (γ) decay branching ratio currently provides the most accurate test of lepton universality. The PEN experiment at PSI, Switzerland, aims to improve the present world average experimental precision of 3 . 3 ×10-3 to 5 ×10-4 using a stopped beam approach. During runs in 2008-10, PEN has acquired over 2 ×107 πe 2 events. The experiment includes active beam detectors (degrader, mini TPC, target), central MWPC tracking with plastic scintillator hodoscopes, and a spherical pure CsI electromagnetic shower calorimeter. The final branching ratio will be calculated using a maximum likelihood analysis. This analysis assigns each event a probability for 5 processes (π+ -->e+ ν , π+ -->μ+ ν , decay-in-flight, pile-up, and hadronic events) using Monte Carlo verified probability distribution functions of our observables (energies, times, etc). A progress report on the PEN maximum likelihood analysis will be presented. Work supported by NSF grant PHY-0970013.

  17. Comparison of in situ and airborne spectral measurements of the blue shift associated with forest decline

    Rock, B. N.; Hoshizaki, T.; Miller, J. R.


    Visible IR Intelligent Spectrometer (VIRIS) reflectance data have been found to have similar features that are related to air-pollution-induced forest decline and visible damage in both the red spruce of Vermont and the Norway spruce of Baden-Wuerttemberg; the similarity suggests a common source of damage. Spectra of both species include a 5-nm blueshifting of the red-edge inflection point, while pigment data for both species indicate a loss of total chlorophylls. The blue shift of the chlorophyll absorption maximum, as well as the increased red radiance and decreased near-IR radiance of the damaged spruce, may be used to delineate and map damage areas.

  18. Influence of subglottic stenosis on the flow-induced vibration of a computational vocal fold model

    Smith, Simeon L.; Thomson, Scott L.


    The effect of subglottic stenosis on vocal fold vibration is investigated. An idealized stenosis is defined, parameterized, and incorporated into a two-dimensional, fully coupled finite element model of the vocal folds and laryngeal airway. Flow-induced responses of the vocal fold model to varying severities of stenosis are compared. The model vibration was not appreciably affected by stenosis severities of up to 60% occlusion. Model vibration was altered by stenosis severities of 90% or greater, evidenced by decreased superior model displacement, glottal width amplitude, and flow rate amplitude. Predictions of vibration frequency and maximum flow declination rate were also altered by high stenosis severities. The observed changes became more pronounced with increasing stenosis severity and inlet pressure, and the trends correlated well with flow resistance calculations. Flow visualization was used to characterize subglottal flow patterns in the space between the stenosis and the vocal folds. Underlying mechanisms for the observed changes, possible implications for human voice production, and suggestions for future work are discussed.

  19. Paddle River Dam : review of probable maximum flood

    Clark, D. [UMA Engineering Ltd., Edmonton, AB (Canada); Neill, C.R. [Northwest Hydraulic Consultants Ltd., Edmonton, AB (Canada)


    The Paddle River Dam was built in northern Alberta in the mid 1980s for flood control. According to the 1999 Canadian Dam Association (CDA) guidelines, this 35 metre high, zoned earthfill dam with a spillway capacity sized to accommodate a probable maximum flood (PMF) is rated as a very high hazard. At the time of design, it was estimated to have a peak flow rate of 858 centimetres. A review of the PMF in 2002 increased the peak flow rate to 1,890 centimetres. In light of a 2007 revision of the CDA safety guidelines, the PMF was reviewed and the inflow design flood (IDF) was re-evaluated. This paper discussed the levels of uncertainty inherent in PMF determinations and some difficulties encountered with the SSARR hydrologic model and the HEC-RAS hydraulic model in unsteady mode. The paper also presented and discussed the analysis used to determine incremental damages, upon which a new IDF of 840 m{sup 3}/s was recommended. The paper discussed the PMF review, modelling methodology, hydrograph inputs, and incremental damage of floods. It was concluded that the PMF review, involving hydraulic routing through the valley bottom together with reconsideration of the previous runoff modeling provides evidence that the peak reservoir inflow could reasonably be reduced by approximately 20 per cent. 8 refs., 5 tabs., 8 figs.

  20. Stress and decline with forest trees. Stress und Decline bei Waldbaeumen

    Tesche, M. (Technische Univ. Dresden, Tharandt (Germany, F.R.). Abt. Forstwirtschaft)


    Stress and decline are two terms used in a different manner in connection with current forest damages. Using examples, it is demonstrated that effects of complex environmental stress do not only depend upon the genotypic reaction capability of plants and the intensity of stress, but also on the combination and constellation as well as the way of influence exerted by individual stressors; low stress intensities lasting for a limited time can result in an adaption stimulation for plants, which should be called eustress and complex stress situations do not necessarily lead to an intensification of the effect caused by individual stressors and thus not to distress. Investigations carried out during or immediately after the impact of stress (instant effects) are not sufficient for diagnosing defence or adaptation reactions. Effects of this kind (memory effects) can only be identified in long-term experiments. From the results one can conclude that the 'decline-spiral-model' by MANION (1981) simplifies things too much, because it does not consider the defence and adaptation potential of plants. (orig.).

  1. Lake Basin Fetch and Maximum Length/Width

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  2. Production decline analysis for a multi-fractured horizontal well considering elliptical reservoir stimulated volumes in shale gas reservoirs

    Wei, Mingqiang; Duan, Yonggang; Fang, Quantang; Zhang, Tiantian


    Multi-fractured horizontal wells (MFHWs) are an effective technique for developing shale gas reservoirs. After fracturing, stimulated reservoir volumes (SRVs) invariably exist around the wellbore. In this paper, a composite elliptical SRV model for each hydraulic fracturing stage is established, based on micro-seismic events. Both the SRV and the outer regions are assumed as single-porosity media with different formation physical parameters. Based on unstructured perpendicular bisection (PEBI) grids, a mathematical model considering Darcy flow, diffusion and adsorption/desorption in shale gas reservoirs is presented. The numerical solution is obtained by combining the control volume finite element method with the fully implicit method. The model is verified by a simplified model solution. The MFHW Blasingame production decline curves, which consider elliptical SRVs in shale gas reservoirs, are plotted by computer programming. The flow regions can be divided into five flow regimes: early formation linear flow, radial flow in the SRV region, transient flow, pseudo radial flow and boundary dominated flow. Finally, the effect of six related parameters, including the SRV area size, outer region permeability, SRV region permeability, Langmuir pressure, Langmuir volume and diffusion coefficient, are analyzed on type curves. The model presented in this paper can expand our understanding of MFHW production decline behaviors in shale gas reservoirs and can be applied to estimate reservoir properties, the SRV area, and reserves in these types of reservoirs by type curve matching.

  3. Temperature decline thermography for laminar-turbulent transition detection in aerodynamics

    von Hoesslin, Stefan; Stadlbauer, Martin; Gruendmayer, Juergen; Kähler, Christian J.


    Detailed knowledge about laminar-turbulent transition and heat transfer distribution of flows around complex aerodynamic components are crucial to achieve highest efficiencies in modern aerodynamical systems. Several measurement techniques have been developed to determine those parameters either quantitatively or qualitatively. Most of them require extensive instrumentation or give unreliable results as the boundary conditions are often not known with the required precision. This work introduces the simple and robust temperature decline method to qualitatively detect the laminar-turbulent transition and the respective heat transfer coefficients on a surface exposed to an air flow, according to patent application Stadlbauer et al. (Patentnr. WO2014198251 A1, 2014). This method provides results which are less sensitive to control parameters such as the heat conduction into the blade material and temperature inhomogeneities in the flow or blade. This method was applied to measurements with NACA0018 airfoils exposed to the flow of a calibration-free jet at various Reynolds numbers and angles of attack. For data analysis, a post-processing method was developed and qualified to determine a quantity proportional to the heat transfer coefficient into the flow. By plotting this quantity for each pixel of the surface, a qualitative, two-dimensional heat transfer map was obtained. The results clearly depicted the areas of onset and end of transition over the full span of the model and agreed with the expected behavior based on the respective flow condition. To validate the approach, surface hotfilm measurements were conducted simultaneously on the same NACA profile. Both techniques showed excellent agreement. The temperature decline method allows to visualize laminar-turbulent transitions on static or moving parts and can be applied on a very broad range of scales—from tiny airfoils up to large airplane wings.

  4. Is the gender wage gap declining in the Netherlands?

    van der Meer, P.H.


    In this paper I try to answer the question whether the gender wage gap in the Netherlands is declining. I posed this question because on several other indicators labour market differences between men and women in the Netherlands declined or disappeared altogether. First of all the labour market part

  5. Does Child Labor Decline with Improving Economic Status?

    Edmonds, Eric V.


    The rapid economic growth of Vietnam provides an interesting insight into the sharp decline in child labor. A study of the rising economic status of the population across Vietnam shows that children returned to school or stopped working as their family incomes grew. The decline in child labor is steep in poor households as they emerged from…

  6. Did the Decline in Social Connections Depress Americans' Happiness?

    Bartolini, Stefano; Bilancini, Ennio; Pugno, Maurizio


    During the last 30 years US citizens experienced, on average, a decline in reported happiness, social connections, and confidence in institutions. We show that a remarkable portion of the decrease in happiness is predicted by the decline in social connections and confidence in institutions. We carry out our investigation in three steps. First, we…

  7. Serum cholesterol decline and depression in the postpartum period

    Dam, van R.M.; Schuit, A.J.; Schouten, E.G.; Vader, H.L.; Pop, V.J.M.


    We examined the relation between total serum cholesterol decline and depression in the postpartum period in a prospective study of 266 Dutch women, who were followed until 34 weeks after delivery. The decline in serum cholesterol between week 32 of pregnancy and week 10 postpartum was similar for wo

  8. Creative Management in a Time of Economic Decline.

    Millett, John D.

    Economic decline is indicated by productivity per man-hour of work, per capita real personal income, and real gross national product. Unless new technology overcomes the force of a stable population and develops new sources of raw materials and of energy, economic decline seems a likely possibility. Creative management is a process of planning,…


    Amphibian population declines have been noted on both local and global scales. Causes for these declines are unknown although many hypotheses have been offered. In areas adjacent to human development, loss of habitat is a fairly well accepted cause. However in isolated, seemingl...

  10. Predicting cognitive decline in Alzheimer's disease: an integrated analysis

    Lopez, Oscar L; Schwam, Elias; Cummings, Jeffrey


    Numerous patient- and disease-related factors increase the risk of rapid cognitive decline in patients with Alzheimer's disease (AD). The ability of pharmacological treatment to attenuate this risk remains undefined.......Numerous patient- and disease-related factors increase the risk of rapid cognitive decline in patients with Alzheimer's disease (AD). The ability of pharmacological treatment to attenuate this risk remains undefined....

  11. Predicting cognitive decline in Alzheimer's disease: an integrated analysis

    Lopez, Oscar L; Schwam, Elias; Cummings, Jeffrey


    Numerous patient- and disease-related factors increase the risk of rapid cognitive decline in patients with Alzheimer's disease (AD). The ability of pharmacological treatment to attenuate this risk remains undefined.......Numerous patient- and disease-related factors increase the risk of rapid cognitive decline in patients with Alzheimer's disease (AD). The ability of pharmacological treatment to attenuate this risk remains undefined....

  12. Does Child Labor Decline with Improving Economic Status?

    Edmonds, Eric V.


    The rapid economic growth of Vietnam provides an interesting insight into the sharp decline in child labor. A study of the rising economic status of the population across Vietnam shows that children returned to school or stopped working as their family incomes grew. The decline in child labor is steep in poor households as they emerged from…

  13. Identification of older hospitalized patients at risk for functional decline

    Hoogerduijn, J.G.


    Between 30% and 60% of older patients experience functional decline after hospitalization, resulting in a decline in health-related quality of life and autonomy. This is associated with increased risk of readmission, nursing home placement and mortality, increased length of hospital stay and

  14. Did the Decline in Social Connections Depress Americans' Happiness?

    Bartolini, Stefano; Bilancini, Ennio; Pugno, Maurizio


    During the last 30 years US citizens experienced, on average, a decline in reported happiness, social connections, and confidence in institutions. We show that a remarkable portion of the decrease in happiness is predicted by the decline in social connections and confidence in institutions. We carry out our investigation in three steps. First, we…




    The population of African elephant (Loxodonta africana (Blumenbach)) in Lake Manyara National Park, northern Tanzania, declined from about 500 individuals in 1984, to about 150 in 1988 due to poaching (mortality rate about 60% p.a.). In 1991 the population had declined further to about 60 individual

  16. Assessment of Loblolly Pine Decline in Central Alabama

    Nolan J. Hess; William J. Otrosina; Emily A. Carter; Jim R. Steinman; John P. Jones; Lori G. Eckhardt; Ann M. Weber; Charles H. Walkinshaw


    Loblolly pine (Pinus taeda L.) decline has been prevalent on upland sites of central Alabama since the 1960's. The purpose of this study was to compare Forest Health Monitoring (FHM) standards and protocols with root health evaluations relative to crown, stem, and site measurements. Thirty-nine 1/6 acre plots were established on loblolly decline...

  17. Relapse in FEV1 Decline After Steroid Withdrawal in COPD

    Kunz, Lisette I. Z.; Postma, Dirkje S.; Klooster, Karin; Lapperre, Therese S.; Vonk, Judith M.; Sont, Jacob K.; Kerstjens, Huib A. M.; Snoeck-Stroband, Jiska B.; Hiemstra, Pieter S.; Sterk, Peter J.


    BACKGROUND: We previously observed that 30 months of inhaled corticosteroid (ICS) treatment can attenuate FEV1 decline in COPD, but it is unclear whether withdrawal induces a relapse. We hypothesized that FEV1 decline, airway hyperresponsiveness (AHR), and quality of life (QOL) deteriorate after ICS

  18. Declining Trends in Student Performance in Lower Secondary Education

    Wijsman, Lindy A.; Warrens, Matthijs J.; Saab, Nadira; van Driel, Jan H.; Westenberg, P. Michiel


    Student performance is related to motivation to learn. As motivation generally declines during lower secondary education, one might expect performance to decline as well during this period. Though, until now, it has been unclear whether this pattern exists. In the present study, we examined student performance during the early years of secondary…

  19. Maximum entropy principle and texture formation

    Arminjon, M; Arminjon, Mayeul; Imbault, Didier


    The macro-to-micro transition in a heterogeneous material is envisaged as the selection of a probability distribution by the Principle of Maximum Entropy (MAXENT). The material is made of constituents, e.g. given crystal orientations. Each constituent is itself made of a large number of elementary constituents. The relevant probability is the volume fraction of the elementary constituents that belong to a given constituent and undergo a given stimulus. Assuming only obvious constraints in MAXENT means describing a maximally disordered material. This is proved to have the same average stimulus in each constituent. By adding a constraint in MAXENT, a new model, potentially interesting e.g. for texture prediction, is obtained.

  20. MLDS: Maximum Likelihood Difference Scaling in R

    Kenneth Knoblauch


    Full Text Available The MLDS package in the R programming language can be used to estimate perceptual scales based on the results of psychophysical experiments using the method of difference scaling. In a difference scaling experiment, observers compare two supra-threshold differences (a,b and (c,d on each trial. The approach is based on a stochastic model of how the observer decides which perceptual difference (or interval (a,b or (c,d is greater, and the parameters of the model are estimated using a maximum likelihood criterion. We also propose a method to test the model by evaluating the self-consistency of the estimated scale. The package includes an example in which an observer judges the differences in correlation between scatterplots. The example may be readily adapted to estimate perceptual scales for arbitrary physical continua.

  1. Maximum Segment Sum, Monadically (distilled tutorial

    Jeremy Gibbons


    Full Text Available The maximum segment sum problem is to compute, given a list of integers, the largest of the sums of the contiguous segments of that list. This problem specification maps directly onto a cubic-time algorithm; however, there is a very elegant linear-time solution too. The problem is a classic exercise in the mathematics of program construction, illustrating important principles such as calculational development, pointfree reasoning, algebraic structure, and datatype-genericity. Here, we take a sideways look at the datatype-generic version of the problem in terms of monadic functional programming, instead of the traditional relational approach; the presentation is tutorial in style, and leavened with exercises for the reader.

  2. Maximum Information and Quantum Prediction Algorithms

    McElwaine, J N


    This paper describes an algorithm for selecting a consistent set within the consistent histories approach to quantum mechanics and investigates its properties. The algorithm uses a maximum information principle to select from among the consistent sets formed by projections defined by the Schmidt decomposition. The algorithm unconditionally predicts the possible events in closed quantum systems and ascribes probabilities to these events. A simple spin model is described and a complete classification of all exactly consistent sets of histories formed from Schmidt projections in the model is proved. This result is used to show that for this example the algorithm selects a physically realistic set. Other tentative suggestions in the literature for set selection algorithms using ideas from information theory are discussed.

  3. Maximum process problems in optimal control theory

    Goran Peskir


    Full Text Available Given a standard Brownian motion (Btt≥0 and the equation of motion dXt=vtdt+2dBt, we set St=max0≤s≤tXs and consider the optimal control problem supvE(Sτ−Cτ, where c>0 and the supremum is taken over all admissible controls v satisfying vt∈[μ0,μ1] for all t up to τ=inf{t>0|Xt∉(ℓ0,ℓ1} with μ0g∗(St, where s↦g∗(s is a switching curve that is determined explicitly (as the unique solution to a nonlinear differential equation. The solution found demonstrates that the problem formulations based on a maximum functional can be successfully included in optimal control theory (calculus of variations in addition to the classic problem formulations due to Lagrange, Mayer, and Bolza.

  4. Maximum Spectral Luminous Efficacy of White Light

    Murphy, T W


    As lighting efficiency improves, it is useful to understand the theoretical limits to luminous efficacy for light that we perceive as white. Independent of the efficiency with which photons are generated, there exists a spectrally-imposed limit to the luminous efficacy of any source of photons. We find that, depending on the acceptable bandpass and---to a lesser extent---the color temperature of the light, the ideal white light source achieves a spectral luminous efficacy of 250--370 lm/W. This is consistent with previous calculations, but here we explore the maximum luminous efficacy as a function of photopic sensitivity threshold, color temperature, and color rendering index; deriving peak performance as a function of all three parameters. We also present example experimental spectra from a variety of light sources, quantifying the intrinsic efficacy of their spectral distributions.

  5. Maximum entropy model for business cycle synchronization

    Xi, Ning; Muneepeerakul, Rachata; Azaele, Sandro; Wang, Yougui


    The global economy is a complex dynamical system, whose cyclical fluctuations can mainly be characterized by simultaneous recessions or expansions of major economies. Thus, the researches on the synchronization phenomenon are key to understanding and controlling the dynamics of the global economy. Based on a pairwise maximum entropy model, we analyze the business cycle synchronization of the G7 economic system. We obtain a pairwise-interaction network, which exhibits certain clustering structure and accounts for 45% of the entire structure of the interactions within the G7 system. We also find that the pairwise interactions become increasingly inadequate in capturing the synchronization as the size of economic system grows. Thus, higher-order interactions must be taken into account when investigating behaviors of large economic systems.

  6. Quantum gravity momentum representation and maximum energy

    Moffat, J. W.


    We use the idea of the symmetry between the spacetime coordinates xμ and the energy-momentum pμ in quantum theory to construct a momentum space quantum gravity geometry with a metric sμν and a curvature tensor Pλ μνρ. For a closed maximally symmetric momentum space with a constant 3-curvature, the volume of the p-space admits a cutoff with an invariant maximum momentum a. A Wheeler-DeWitt-type wave equation is obtained in the momentum space representation. The vacuum energy density and the self-energy of a charged particle are shown to be finite, and modifications of the electromagnetic radiation density and the entropy density of a system of particles occur for high frequencies.

  7. Video segmentation using Maximum Entropy Model

    QIN Li-juan; ZHUANG Yue-ting; PAN Yun-he; WU Fei


    Detecting objects of interest from a video sequence is a fundamental and critical task in automated visual surveillance.Most current approaches only focus on discriminating moving objects by background subtraction whether or not the objects of interest can be moving or stationary. In this paper, we propose layers segmentation to detect both moving and stationary target objects from surveillance video. We extend the Maximum Entropy (ME) statistical model to segment layers with features, which are collected by constructing a codebook with a set of codewords for each pixel. We also indicate how the training models are used for the discrimination of target objects in surveillance video. Our experimental results are presented in terms of the success rate and the segmenting precision.

  8. The Gulf: a young sea in decline.

    Sheppard, Charles; Al-Husiani, Mohsen; Al-Jamali, F; Al-Yamani, Faiza; Baldwin, Rob; Bishop, James; Benzoni, Francesca; Dutrieux, Eric; Dulvy, Nicholas K; Durvasula, Subba Rao V; Jones, David A; Loughland, Ron; Medio, David; Nithyanandan, M; Pilling, Graham M; Polikarpov, Igor; Price, Andrew R G; Purkis, Sam; Riegl, Bernhard; Saburova, Maria; Namin, Kaveh Samimi; Taylor, Oliver; Wilson, Simon; Zainal, Khadija


    This review examines the substantial changes that have taken place in marine habitats and resources of the Gulf over the past decade. The habitats are especially interesting because of the naturally high levels of temperature and salinity stress they experience, which is important in a changing world climate. However, the extent of all natural habitats is changing and their condition deteriorating because of the rapid development of the region and, in some cases from severe, episodic warming episodes. Major impacts come from numerous industrial, infrastructure-based, and residential and tourism development activities, which together combine, synergistically in some cases, to cause the observed deterioration in most benthic habitats. Substantial sea bottom dredging for material and its deposition in shallow water to extend land or to form a basis for huge developments, directly removes large areas of shallow, productive habitat, though in some cases the most important effect is the accompanying sedimentation or changes to water flows and conditions. The large scale of the activities compared to the relatively shallow and small size of the water body is a particularly important issue. Important from the perspective of controlling damaging effects is the limited cross-border collaboration and even intra-country collaboration among government agencies and large projects. Along with the accumulative nature of impacts that occur, even where each project receives environmental assessment or attention, each is treated more or less alone, rarely in combination. However, their combination in such a small, biologically interacting sea exacerbates the overall deterioration. Very few similar areas exist which face such a high concentration of disturbance, and the prognosis for the Gulf continuing to provide abundant natural resources is poor. Copyright 2009. Published by Elsevier Ltd.

  9. Evaluation of pliers' grip spans in the maximum gripping task and sub-maximum cutting task.

    Kim, Dae-Min; Kong, Yong-Ku


    A total of 25 males participated to investigate the effects of the grip spans of pliers on the total grip force, individual finger forces and muscle activities in the maximum gripping task and wire-cutting tasks. In the maximum gripping task, results showed that the 50-mm grip span had significantly higher total grip strength than the other grip spans. In the cutting task, the 50-mm grip span also showed significantly higher grip strength than the 65-mm and 80-mm grip spans, whereas the muscle activities showed a higher value at 80-mm grip span. The ratios of cutting force to maximum grip strength were also investigated. Ratios of 30.3%, 31.3% and 41.3% were obtained by grip spans of 50-mm, 65-mm, and 80-mm, respectively. Thus, the 50-mm grip span for pliers might be recommended to provide maximum exertion in gripping tasks, as well as lower maximum-cutting force ratios in the cutting tasks.

  10. Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

    Hall, Alex


    We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with very promising results. We find that the introduction of an intrinsic shape prior mitigates noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely sub-dominant. We show how biases propagate to shear estima...

  11. Bottleneck flows in networks

    Punnen, Abraham P


    The bottleneck network flow problem (BNFP) is a generalization of several well-studied bottleneck problems such as the bottleneck transportation problem (BTP), bottleneck assignment problem (BAP), bottleneck path problem (BPP), and so on. In this paper we provide a review of important results on this topic and its various special cases. We observe that the BNFP can be solved as a sequence of $O(\\log n)$ maximum flow problems. However, special augmenting path based algorithms for the maximum flow problem can be modified to obtain algorithms for the BNFP with the property that these variations and the corresponding maximum flow algorithms have identical worst case time complexity. On unit capacity network we show that BNFP can be solved in $O(\\min \\{{m(n\\log n)}^{{2/3}}, m^{{3/2}}\\sqrt{\\log n}\\})$. This improves the best available algorithm by a factor of $\\sqrt{\\log n}$. On unit capacity simple graphs, we show that BNFP can be solved in $O(m \\sqrt {n \\log n})$ time. As a consequence we have an $O(m \\sqrt {n \\l...

  12. Basis for the Age-related Decline in Intestinal Mucosal Immunity

    Douglas L. Schmucker


    Full Text Available The elderly are characterized by mucosal immunosenescence and high rates of morbidity and mortality associated with infectious diseases of the intestinal tract. Little is known about how the differentiation of immunoglobulin A (IgA plasma cells in Peyer's patches (PPs and their subsequent homing to the small intestinal lamina propria (LP is affected by aging. Quantitative immunohistochemical analyses demonstrated a 2-fold increase in the number of IgA+ cells in the PPs, coupled with significant declines in the numbers of IgA+ and antibody-positive cells in the intestinal LP of senescent rats compared to young adult animals. These data suggest that aging diminishes the emigration of IgA immunoblasts from these lymphoid aggregates, as well as their migration to the intestinal LP. Flow cytometry and lymphocyte adoptive transfer studies showed 3- to 4-fold age-related declines in the homing of antibody-containing cells and mesenteric lymph node lymphocytes to the small intestines of rhesus macaques and rats, respectively. The number of peripheral blood IgA immunoblasts expressing the homing molecule α4β7 declined 30% in senescent rats. This was accompanied by a >17% decrease in the areal density of LP blood vessels staining positive for the cell adhesion molecule MAdCAM-1. Cumulatively, declines in expression of these homing molecules constitute a substantial age-related diminution of IgA immunoblast homing potential. In vitro antibody secretion by LP plasma cells, i.e. antibody secreted per antibody-positive cell, remains unchanged as a function of donor age. Intestinal mucosal immunosenescence is a consequence of reduced homing of IgA plasma cells to the intestinal LP as a result of declines in homing molecule expression.

  13. The relationship between the Guinea Highlands and the West African offshore rainfall maximum

    Hamilton, H. L.; Young, G. S.; Evans, J. L.; Fuentes, J. D.; Núñez Ocasio, K. M.


    Satellite rainfall estimates reveal a consistent rainfall maximum off the West African coast during the monsoon season. An analysis of 16 years of rainfall in the monsoon season is conducted to explore the drivers of such copious amounts of rainfall. Composites of daily rainfall and midlevel meridional winds centered on the days with maximum rainfall show that the day with the heaviest rainfall follows the strongest midlevel northerlies but coincides with peak low-level moisture convergence. Rain type composites show that convective rain dominates the study region. The dominant contribution to the offshore rainfall maximum is convective development driven by the enhancement of upslope winds near the Guinea Highlands. The enhancement in the upslope flow is closely related to African easterly waves propagating off the continent that generate low-level cyclonic vorticity and convergence. Numerical simulations reproduce the observed rainfall maximum and indicate that it weakens if the African topography is reduced.

  14. 20 CFR 211.14 - Maximum creditable compensation.


    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Maximum creditable compensation. 211.14... CREDITABLE RAILROAD COMPENSATION § 211.14 Maximum creditable compensation. Maximum creditable compensation... Employment Accounts shall notify each employer of the amount of maximum creditable compensation applicable...

  15. 49 CFR 230.24 - Maximum allowable stress.


    ... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

  16. Rapid cognitive decline in Alzheimer's disease. Consensus paper.

    Soto, M E; Andrieu, S; Arbus, C; Ceccaldi, M; Couratier, P; Dantoine, T; Dartigues, J-F; Gillette-Guyonnet, S; Nourhashemi, F; Ousset, P-J; Poncet, M; Portet, F; Touchon, J; Vellas, B


    The rate of cognitive decline in Alzheimer's disease (AD) varies considerably between individuals, with some subjects showing substantial deterioration and others showing little or no change over the course of the disease. These wide variations support the relatively new concept of Rapid Cognitive Decline (RCD). Patients with an accelerated rate of cognitive decline have showed to present a worse evolution in terms of mortality, loss of autonomy and institutionalisation. The conclusions from RCD studies conducted in the past years remain very heterogeneous and sometimes contradictory. This is possibly due to methodological differences, mainly the different "a priori" definitions of RCD used to identify rapid decliners. Consequently of this, there is considerable variation in reported frequency of patients with RCD which may vary from 9.5% to 54%. The lack of both consensus definition and consensual clinical assessment tools is one of the major barriers for establishing an appropriated management of rapid decliners in clinical practice. Presently, management of rapid decliners in AD remains to be a challenge waiting to better know predictive factors of a RCD. To date no specific guidelines exist to follow-up or to treat patients with this condition. This consensus paper proposes the loss of 3 points or greater in Mini-Mental State Examination (MMSE) during six months as an empirical definition of rapid cognitive decline to be used in routine medical practice and to be relevant for clinical-decision making in patients with mild to moderately-severe AD.

  17. Tree decline and the future of Australian farmland biodiversity.

    Fischer, Joern; Zerger, Andre; Gibbons, Phil; Stott, Jenny; Law, Bradley S


    Farmland biodiversity is greatly enhanced by the presence of trees. However, farmland trees are declining worldwide, including in North America, Central America, and parts of southern Europe. We show that tree decline and its likely consequences are particularly severe in Australia's temperate agricultural zone, which is a threatened ecoregion. Using field data on trees, remotely sensed imagery, and a demographic model for trees, we predict that by 2100, the number of trees on an average farm will contract to two-thirds of its present level. Statistical habitat models suggest that this tree decline will negatively affect many currently common animal species, with predicted declines in birds and bats of up to 50% by 2100. Declines were predicted for 24 of 32 bird species modeled and for all of six bat species modeled. Widespread declines in trees, birds, and bats may lead to a reduction in economically important ecosystem services such as shade provision for livestock and pest control. Moreover, many other species for which we have no empirical data also depend on trees, suggesting that fundamental changes in ecosystem functioning are likely. We conclude that Australia's temperate agricultural zone has crossed a threshold and no longer functions as a self-sustaining woodland ecosystem. A regime shift is occurring, with a woodland system deteriorating into a treeless pasture system. Management options exist to reverse tree decline, but new policy settings are required to encourage their widespread adoption.

  18. Healthy eating and reduced risk of cognitive decline

    Dehghan, Mahshid; O'Donnell, Martin; Anderson, Craig; Teo, Koon; Gao, Peggy; Sleight, Peter; Dagenais, Gilles; Probstfield, Jeffrey L.; Mente, Andrew; Yusuf, Salim


    Objective: We sought to determine the association of dietary factors and risk of cognitive decline in a population at high risk of cardiovascular disease. Methods: Baseline dietary intake and measures of the Mini-Mental State Examination were recorded in 27,860 men and women who were enrolled in 2 international parallel trials of the ONTARGET (Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial) and TRANSCEND (Telmisartan Randomised Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease) studies. We measured diet quality using the modified Alternative Healthy Eating Index. Cox proportional hazards regression was used to determine the association between diet quality and risk of ≥3-point decline in Mini-Mental State Examination score, and reported as hazard ratio with 95% confidence intervals with adjustment for covariates. Results: During 56 months of follow-up, 4,699 cases of cognitive decline occurred. We observed lower risk of cognitive decline among those in the healthiest dietary quintile of modified Alternative Healthy Eating Index compared with lowest quintile (hazard ratio 0.76, 95% confidence interval 0.66–0.86, Q5 vs Q1). Lower risk of cognitive decline was consistent regardless of baseline cognitive level. Conclusion: We found that higher diet quality was associated with a reduced risk of cognitive decline. Improved diet quality represents an important potential target for reducing the global burden of cognitive decline. PMID:25948720

  19. Theoretical Estimate of Maximum Possible Nuclear Explosion

    Bethe, H. A.


    The maximum nuclear accident which could occur in a Na-cooled, Be moderated, Pu and power producing reactor is estimated theoretically. (T.R.H.) 2O82 Results of nuclear calculations for a variety of compositions of fast, heterogeneous, sodium-cooled, U-235-fueled, plutonium- and power-producing reactors are reported. Core compositions typical of plate-, pin-, or wire-type fuel elements and with uranium as metal, alloy, and oxide were considered. These compositions included atom ratios in the following range: U-23B to U-235 from 2 to 8; sodium to U-235 from 1.5 to 12; iron to U-235 from 5 to 18; and vanadium to U-235 from 11 to 33. Calculations were performed to determine the effect of lead and iron reflectors between the core and blanket. Both natural and depleted uranium were evaluated as the blanket fertile material. Reactors were compared on a basis of conversion ratio, specific power, and the product of both. The calculated results are in general agreement with the experimental results from fast reactor assemblies. An analysis of the effect of new cross-section values as they became available is included. (auth)

  20. Proposed principles of maximum local entropy production.

    Ross, John; Corlan, Alexandru D; Müller, Stefan C


    Articles have appeared that rely on the application of some form of "maximum local entropy production principle" (MEPP). This is usually an optimization principle that is supposed to compensate for the lack of structural information and measurements about complex systems, even systems as complex and as little characterized as the whole biosphere or the atmosphere of the Earth or even of less known bodies in the solar system. We select a number of claims from a few well-known papers that advocate this principle and we show that they are in error with the help of simple examples of well-known chemical and physical systems. These erroneous interpretations can be attributed to ignoring well-established and verified theoretical results such as (1) entropy does not necessarily increase in nonisolated systems, such as "local" subsystems; (2) macroscopic systems, as described by classical physics, are in general intrinsically deterministic-there are no "choices" in their evolution to be selected by using supplementary principles; (3) macroscopic deterministic systems are predictable to the extent to which their state and structure is sufficiently well-known; usually they are not sufficiently known, and probabilistic methods need to be employed for their prediction; and (4) there is no causal relationship between the thermodynamic constraints and the kinetics of reaction systems. In conclusion, any predictions based on MEPP-like principles should not be considered scientifically founded.

  1. Maximum entropy production and plant optimization theories.

    Dewar, Roderick C


    Plant ecologists have proposed a variety of optimization theories to explain the adaptive behaviour and evolution of plants from the perspective of natural selection ('survival of the fittest'). Optimization theories identify some objective function--such as shoot or canopy photosynthesis, or growth rate--which is maximized with respect to one or more plant functional traits. However, the link between these objective functions and individual plant fitness is seldom quantified and there remains some uncertainty about the most appropriate choice of objective function to use. Here, plants are viewed from an alternative thermodynamic perspective, as members of a wider class of non-equilibrium systems for which maximum entropy production (MEP) has been proposed as a common theoretical principle. I show how MEP unifies different plant optimization theories that have been proposed previously on the basis of ad hoc measures of individual fitness--the different objective functions of these theories emerge as examples of entropy production on different spatio-temporal scales. The proposed statistical explanation of MEP, that states of MEP are by far the most probable ones, suggests a new and extended paradigm for biological evolution--'survival of the likeliest'--which applies from biomacromolecules to ecosystems, not just to individuals.

  2. Maximum likelihood continuity mapping for fraud detection

    Hogden, J.


    The author describes a novel time-series analysis technique called maximum likelihood continuity mapping (MALCOM), and focuses on one application of MALCOM: detecting fraud in medical insurance claims. Given a training data set composed of typical sequences, MALCOM creates a stochastic model of sequence generation, called a continuity map (CM). A CM maximizes the probability of sequences in the training set given the model constraints, CMs can be used to estimate the likelihood of sequences not found in the training set, enabling anomaly detection and sequence prediction--important aspects of data mining. Since MALCOM can be used on sequences of categorical data (e.g., sequences of words) as well as real valued data, MALCOM is also a potential replacement for database search tools such as N-gram analysis. In a recent experiment, MALCOM was used to evaluate the likelihood of patient medical histories, where ``medical history`` is used to mean the sequence of medical procedures performed on a patient. Physicians whose patients had anomalous medical histories (according to MALCOM) were evaluated for fraud by an independent agency. Of the small sample (12 physicians) that has been evaluated, 92% have been determined fraudulent or abusive. Despite the small sample, these results are encouraging.

  3. Maximum life spiral bevel reduction design

    Savage, M.; Prasanna, M. G.; Coe, H. H.


    Optimization is applied to the design of a spiral bevel gear reduction for maximum life at a given size. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial values. Gear tooth bending strength and minimum contact ratio under load are included in the active constraints. The optimal design of the spiral bevel gear reduction includes the selection of bearing and shaft proportions in addition to gear mesh parameters. System life is maximized subject to a fixed back-cone distance of the spiral bevel gear set for a specified speed ratio, shaft angle, input torque, and power. Significant parameters in the design are: the spiral angle, the pressure angle, the numbers of teeth on the pinion and gear, and the location and size of the four support bearings. Interpolated polynomials expand the discrete bearing properties and proportions into continuous variables for gradient optimization. After finding the continuous optimum, a designer can analyze near optimal designs for comparison and selection. Design examples show the influence of the bearing lives on the gear parameters in the optimal configurations. For a fixed back-cone distance, optimal designs with larger shaft angles have larger service lives.

  4. CORA - emission line fitting with Maximum Likelihood

    Ness, J.-U.; Wichmann, R.


    The advent of pipeline-processed data both from space- and ground-based observatories often disposes of the need of full-fledged data reduction software with its associated steep learning curve. In many cases, a simple tool doing just one task, and doing it right, is all one wishes. In this spirit we introduce CORA, a line fitting tool based on the maximum likelihood technique, which has been developed for the analysis of emission line spectra with low count numbers and has successfully been used in several publications. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise we derive the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. As an example we demonstrate the functionality of the program with an X-ray spectrum of Capella obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory and choose the analysis of the Ne IX triplet around 13.5 Å.

  5. Finding maximum JPEG image block code size

    Lakhani, Gopal


    We present a study of JPEG baseline coding. It aims to determine the minimum storage needed to buffer the JPEG Huffman code bits of 8-bit image blocks. Since DC is coded separately, and the encoder represents each AC coefficient by a pair of run-length/AC coefficient level, the net problem is to perform an efficient search for the optimal run-level pair sequence. We formulate it as a two-dimensional, nonlinear, integer programming problem and solve it using a branch-and-bound based search method. We derive two types of constraints to prune the search space. The first one is given as an upper-bound for the sum of squares of AC coefficients of a block, and it is used to discard sequences that cannot represent valid DCT blocks. The second type constraints are based on some interesting properties of the Huffman code table, and these are used to prune sequences that cannot be part of optimal solutions. Our main result is that if the default JPEG compression setting is used, space of minimum of 346 bits and maximum of 433 bits is sufficient to buffer the AC code bits of 8-bit image blocks. Our implementation also pruned the search space extremely well; the first constraint reduced the initial search space of 4 nodes down to less than 2 nodes, and the second set of constraints reduced it further by 97.8%.

  6. Maximum likelihood estimates of pairwise rearrangement distances.

    Serdoz, Stuart; Egri-Nagy, Attila; Sumner, Jeremy; Holland, Barbara R; Jarvis, Peter D; Tanaka, Mark M; Francis, Andrew R


    Accurate estimation of evolutionary distances between taxa is important for many phylogenetic reconstruction methods. Distances can be estimated using a range of different evolutionary models, from single nucleotide polymorphisms to large-scale genome rearrangements. Corresponding corrections for genome rearrangement distances fall into 3 categories: Empirical computational studies, Bayesian/MCMC approaches, and combinatorial approaches. Here, we introduce a maximum likelihood estimator for the inversion distance between a pair of genomes, using a group-theoretic approach to modelling inversions introduced recently. This MLE functions as a corrected distance: in particular, we show that because of the way sequences of inversions interact with each other, it is quite possible for minimal distance and MLE distance to differently order the distances of two genomes from a third. The second aspect tackles the problem of accounting for the symmetries of circular arrangements. While, generally, a frame of reference is locked, and all computation made accordingly, this work incorporates the action of the dihedral group so that distance estimates are free from any a priori frame of reference. The philosophy of accounting for symmetries can be applied to any existing correction method, for which examples are offered. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Hierarchical Linear Modeling with Maximum Likelihood, Restricted Maximum Likelihood, and Fully Bayesian Estimation

    Boedeker, Peter


    Hierarchical linear modeling (HLM) is a useful tool when analyzing data collected from groups. There are many decisions to be made when constructing and estimating a model in HLM including which estimation technique to use. Three of the estimation techniques available when analyzing data with HLM are maximum likelihood, restricted maximum…

  8. The story of a 'maverick': Bulgaria's fertility decline.

    Botev, N


    Analysis of the fertility decline in Bulgaria shows that the perception of Bulgaria as an 'anomaly' in terms of its demographic development is based on a conservative interpretatiion of the demographic transition theory. The features that distinguish Bulgaria from the western European countries (faster decline, persistence of early and universal marriages, etc.) are generally accounted for by the specific social, economic, cultural, and political conditions. These findings suggest that the speed of the fertility decline and the means through which it is achieved are affected by a complex interaction between cultural and economic factors that are often difficult to distinguish in terms of primacy.

  9. A New Comprehensive Approach for Predicting Injectivity Decline during Waterflooding

    Yuan, Hao; Nielsen, Sidsel Marie; Shapiro, Alexander

    Injectivity decline during sea waterflooding or produced water re-injection is widely observed in North Sea, Gulf of Mexico and Campos Basin fields. The formation damage occurs mainly due to the deposition of suspended solids around injectors and the build-up the external filter cakes in the well...... injectivity decline during water flooding is proposed. The deep bed filtration is described by novel stochastic random walk equations. The injectivity decline model takes into account the reservoir heterogeneity and the distribution of solid particles by sizes. It also accounts for the later formation...

  10. Financial Declines, Financial Behaviors, and Relationship Satisfaction during the Recession

    Jeffrey P. Dew


    Full Text Available Using nationally-representative data collected during the summer of 2009 (N = 575, this study examines how reports of financial declines are associated with financial behaviors and how financial behaviors are associated with relationship satisfaction among cohabiting and married participants. Findings suggested that financial declines were only negatively associated with sound financial management behavior if participants also experienced feelings of economic pressure. Sound financial management behavior was found to be positively associated with marital satisfaction. Finally, sound financial management behavior also moderated the association between financial declines, economic pressure, and relationship satisfaction.

  11. Analysis of the Velocity Distribution in Partially-Filled Circular Pipe Employing the Principle of Maximum Entropy.

    Jiang, Yulin; Li, Bin; Chen, Jie


    The flow velocity distribution in partially-filled circular pipe was investigated in this paper. The velocity profile is different from full-filled pipe flow, since the flow is driven by gravity, not by pressure. The research findings show that the position of maximum flow is below the water surface, and varies with the water depth. In the region of near tube wall, the fluid velocity is mainly influenced by the friction of the wall and the pipe bottom slope, and the variation of velocity is similar to full-filled pipe. But near the free water surface, the velocity distribution is mainly affected by the contractive tube wall and the secondary flow, and the variation of the velocity is relatively small. Literature retrieval results show relatively less research has been shown on the practical expression to describe the velocity distribution of partially-filled circular pipe. An expression of two-dimensional (2D) velocity distribution in partially-filled circular pipe flow was derived based on the principle of maximum entropy (POME). Different entropies were compared according to fluid knowledge, and non-extensive entropy was chosen. A new cumulative distribution function (CDF) of partially-filled circular pipe velocity in terms of flow depth was hypothesized. Combined with the CDF hypothesis, the 2D velocity distribution was derived, and the position of maximum velocity distribution was analyzed. The experimental results show that the estimated velocity values based on the principle of maximum Tsallis wavelet entropy are in good agreement with measured values.

  12. Using maximum entropy to predict suitable habitat for the endangered dwarf wedgemussel in the Maryland Coastal Plain

    Campbell, Cara; Hilderbrand, Robert H.


    Species distribution modelling can be useful for the conservation of rare and endangered species. Freshwater mussel declines have thinned species ranges producing spatially fragmented distributions across large areas. Spatial fragmentation in combination with a complex life history and heterogeneous environment makes predictive modelling difficult.A machine learning approach (maximum entropy) was used to model occurrences and suitable habitat for the federally endangered dwarf wedgemussel, Alasmidonta heterodon, in Maryland's Coastal Plain catchments. Landscape-scale predictors (e.g. land cover, land use, soil characteristics, geology, flow characteristics, and climate) were used to predict the suitability of individual stream segments for A. heterodon.The best model contained variables at three scales: minimum elevation (segment scale), percentage Tertiary deposits, low intensity development, and woody wetlands (sub-catchment), and percentage low intensity development, pasture/hay agriculture, and average depth to the water table (catchment). Despite a very small sample size owing to the rarity of A. heterodon, cross-validated prediction accuracy was 91%.Most predicted suitable segments occur in catchments not known to contain A. heterodon, which provides opportunities for new discoveries or population restoration. These model predictions can guide surveys toward the streams with the best chance of containing the species or, alternatively, away from those streams with little chance of containing A. heterodon.Developed reaches had low predicted suitability for A. heterodon in the Coastal Plain. Urban and exurban sprawl continues to modify stream ecosystems in the region, underscoring the need to preserve existing populations and to discover and protect new populations.

  13. Maximum likelihood molecular clock comb: analytic solutions.

    Chor, Benny; Khetan, Amit; Snir, Sagi


    Maximum likelihood (ML) is increasingly used as an optimality criterion for selecting evolutionary trees, but finding the global optimum is a hard computational task. Because no general analytic solution is known, numeric techniques such as hill climbing or expectation maximization (EM), are used in order to find optimal parameters for a given tree. So far, analytic solutions were derived only for the simplest model--three taxa, two state characters, under a molecular clock. Four taxa rooted trees have two topologies--the fork (two subtrees with two leaves each) and the comb (one subtree with three leaves, the other with a single leaf). In a previous work, we devised a closed form analytic solution for the ML molecular clock fork. In this work, we extend the state of the art in the area of analytic solutions ML trees to the family of all four taxa trees under the molecular clock assumption. The change from the fork topology to the comb incurs a major increase in the complexity of the underlying algebraic system and requires novel techniques and approaches. We combine the ultrametric properties of molecular clock trees with the Hadamard conjugation to derive a number of topology dependent identities. Employing these identities, we substantially simplify the system of polynomial equations. We finally use tools from algebraic geometry (e.g., Gröbner bases, ideal saturation, resultants) and employ symbolic algebra software to obtain analytic solutions for the comb. We show that in contrast to the fork, the comb has no closed form solutions (expressed by radicals in the input data). In general, four taxa trees can have multiple ML points. In contrast, we can now prove that under the molecular clock assumption, the comb has a unique (local and global) ML point. (Such uniqueness was previously shown for the fork.).

  14. Prey size and availability limits maximum size of rainbow trout in a large tailwater: insights from a drift-foraging bioenergetics model

    Dodrill, Michael J.; Yackulic, Charles B.; Kennedy, Theodore A.; Haye, John W


    The cold and clear water conditions present below many large dams create ideal conditions for the development of economically important salmonid fisheries. Many of these tailwater fisheries have experienced declines in the abundance and condition of large trout species, yet the causes of these declines remain uncertain. Here, we develop, assess, and apply a drift-foraging bioenergetics model to identify the factors limiting rainbow trout (Oncorhynchus mykiss) growth in a large tailwater. We explored the relative importance of temperature, prey quantity, and prey size by constructing scenarios where these variables, both singly and in combination, were altered. Predicted growth matched empirical mass-at-age estimates, particularly for younger ages, demonstrating that the model accurately describes how current temperature and prey conditions interact to determine rainbow trout growth. Modeling scenarios that artificially inflated prey size and abundance demonstrate that rainbow trout growth is limited by the scarcity of large prey items and overall prey availability. For example, shifting 10% of the prey biomass to the 13 mm (large) length class, without increasing overall prey biomass, increased lifetime maximum mass of rainbow trout by 88%. Additionally, warmer temperatures resulted in lower predicted growth at current and lower levels of prey availability; however, growth was similar across all temperatures at higher levels of prey availability. Climate change will likely alter flow and temperature regimes in large rivers with corresponding changes to invertebrate prey resources used by fish. Broader application of drift-foraging bioenergetics models to build a mechanistic understanding of how changes to habitat conditions and prey resources affect growth of salmonids will benefit management of tailwater fisheries.

  15. Flow regime effects on mature Populus fremontii (Fremont cottonwood) productivity on two contrasting dryland river floodplains

    Andersen, Douglas C.


    I compared riparian cottonwood (Populus fremontii) productivity-discharge relationships in a relictual stand along the highly regulated Green River and in a naturally functioning stand along the unregulated Yampa River in semiarid northwest Colorado. I used multiple regression to model flow effects on annual basal area increment (BAI) from 1982 to 2011, after removing any autocorrelation present. Each BAI series was developed from 20 trees whose mean size (67 cm diameter at breast height [DBH]) was equivalent in the two stands. BAI was larger in the Yampa River stand except in 2 y when defoliating leaf beetles were present there. I found no evidence for a Yampa flood-magnitude threshold above which BAI declined. Flow variables explained ∼45% of residual BAI variability, with most explained by current-year maximum 90-d discharge (QM90) in the Yampa River stand and by a measure of the year-to-year change in QM90 in the Green River stand. The latter reflects a management-imposed ceiling on flood magnitude—Flaming Gorge Dam power plant capacity—infrequently exceeded during the study period. BAI in the relictual stand began to trend upward in 1992 when flows started to mimic a natural flow regime. Mature Fremont cottonwoods appear to be ecologically resilient. Their productivity along regulated rivers might be optimized using multiyear environmental flow designs.


    V. E. Kulikov


    Full Text Available Aim. To study extra- and intracranial hemodynamics in patients with chronic hepatitis of different activity.Material and methods. Ultrasonography of the cerebral blood flow was performed in 576 patients with chronic hepatitis.Results. Contralateral hemyspherical asymmetry (more than 30 % of the maximum linear rate of blood flow in the medium cerebral arteries and decrease in resistance index (0,55±0,09 and pulsativity index (1,34±0,66 were found in 33,8 % of patients with chronic hepatitis of high activity. Collateral blood flow reduction through connecting arteries of Willis circle was revealed in 13,8 % of patients. The tortuosity of arteries and thickening of intima-media complex was found in patients with chronic hepatitis (mainly of high activity. It leads to decline of cerebral blood flow.Conclusion. Symptomatic and asymptomatic cerebral blood flow disturbances were observed in 23,2% and 38,8% of patients with active chronic hepatitis respectively.


    V. E. Kulikov


    Full Text Available Aim. To study extra- and intracranial hemodynamics in patients with chronic hepatitis of different activity.Material and methods. Ultrasonography of the cerebral blood flow was performed in 576 patients with chronic hepatitis.Results. Contralateral hemyspherical asymmetry (more than 30 % of the maximum linear rate of blood flow in the medium cerebral arteries and decrease in resistance index (0,55±0,09 and pulsativity index (1,34±0,66 were found in 33,8 % of patients with chronic hepatitis of high activity. Collateral blood flow reduction through connecting arteries of Willis circle was revealed in 13,8 % of patients. The tortuosity of arteries and thickening of intima-media complex was found in patients with chronic hepatitis (mainly of high activity. It leads to decline of cerebral blood flow.Conclusion. Symptomatic and asymptomatic cerebral blood flow disturbances were observed in 23,2% and 38,8% of patients with active chronic hepatitis respectively.

  18. Caries decline before fluoride toothpaste was available: earlier and greater decline in the rural north than in southwestern Norway.

    Birkeland, J M; Haugejorden, O


    The purpose of this study was to evaluate factors related to caries in 6-17-year-olds in 2 groups of Norwegian counties between 1966 and 1983. The average number of surfaces filled and permanent teeth extracted due to caries declined in the 4 northern counties from 1967. An increase was recorded in the 7 southwestern counties until 1971, then a decline. In the 1960s significantly more surfaces were filled and teeth extracted in the north compared to the southwest. Based on intra-county comparisons, the decline in surfaces treated was greater in the north between 1967 and 1983; 5.4 +/- 0.4 vs 3.7 +/- 0.7, P Higher infant mortality, lower percentage of people with completed senior secondary education, and more inhabitants per doctor and per dentist in the north indicate a less favorable situation than in the southwest. School-based fluoride programs had been implemented in both groups from the mid-1960s and around 60% participated when fluoride toothpaste became freely marketed in 1971. More fluoride programs and more fluoride tablets were available to children in the north; this may indicate a preventive attitude among dentists. The decline of caries started at different times in different parts of Norway. In the rural north with the most unfavorable situation, the decline was greater and started years before fluoride toothpaste came on to the market. The early decline may partly be ascribed to the school-based fluoride programs, the continued decline to several factors.

  19. Recent Declines in Warming and Vegetation Greening Trends over Pan-Arctic Tundra

    Igor V. Polyakov


    Full Text Available Vegetation productivity trends for the Arctic tundra are updated for the 1982–2011 period and examined in the context of land surface temperatures and coastal sea ice. Understanding mechanistic links between vegetation and climate parameters contributes to model advancements that are necessary for improving climate projections. This study employs remote sensing data: Global Inventory Modeling and Mapping Studies (GIMMS Maximum Normalized Difference Vegetation Index (MaxNDVI, Special Sensor Microwave Imager (SSM/I sea-ice concentrations, and Advanced Very High Resolution Radiometer (AVHRR radiometric surface temperatures. Spring sea ice is declining everywhere except in the Bering Sea, while summer open water area is increasing throughout the Arctic. Summer Warmth Index (SWI—sum of degree months above freezing trends from 1982 to 2011 are positive around Beringia but are negative over Eurasia from the Barents to the Laptev Seas and in parts of northern Canada. Eastern North America continues to show increased summer warmth and a corresponding steady increase in MaxNDVI. Positive MaxNDVI trends from 1982 to 2011 are generally weaker compared to trends from 1982–2008. So to better understand the changing trends, break points in the time series were quantified using the Breakfit algorithm. The most notable break points identify declines in SWI since 2003 in Eurasia and 1998 in Western North America. The Time Integrated NDVI (TI-NDVI, sum of the biweekly growing season values of MaxNDVI has declined since 2005 in Eurasia, consistent with SWI declines. Summer (June–August sea level pressure (slp averages from 1999–2011 were compared to those from 1982–1998 to reveal higher slp over Greenland and the western Arctic and generally lower pressure over the continental Arctic in the recent period. This suggests that the large-scale circulation is likely a key contributor to the cooler temperatures over Eurasia through increased summer cloud

  20. Volumetric Concentration Maximum of Cohesive Sediment in Waters: A Numerical Study

    Jisun Byun


    Full Text Available Cohesive sediment has different characteristics compared to non-cohesive sediment. The density and size of a cohesive sediment aggregate (a so-called, floc continuously changes through the flocculation process. The variation of floc size and density can cause a change of volumetric concentration under the condition of constant mass concentration. This study investigates how the volumetric concentration is affected by different conditions such as flow velocity, water depth, and sediment suspension. A previously verified, one-dimensional vertical numerical model is utilized here. The flocculation process is also considered by floc in the growth type flocculation model. Idealized conditions are assumed in this study for the numerical experiments. The simulation results show that the volumetric concentration profile of cohesive sediment is different from the Rouse profile. The volumetric concentration decreases near the bed showing the elevated maximum in the cases of both current and oscillatory flow. The density and size of floc show the minimum and the maximum values near the elevation of volumetric concentration maximum, respectively. This study also shows that the flow velocity and the critical shear stress have significant effects on the elevated maximum of volumetric concentration. As mechanisms of the elevated maximum, the strong turbulence intensity and increased mass concentration are considered because they cause the enhanced flocculation process. This study uses numerical experiments. To the best of our knowledge, no laboratory or field experiments on the elevated maximum have been carried out until now. It is of great necessity to conduct well-controlled laboratory experiments in the near future.

  1. Declining amphibian populations: a global phenomenon in conservation biology

    Gardner, T.


    Full Text Available The majority of the recent reductions in the Earth's biodiversity can be attributed to direct human impacts on the environment. An increasing number of studies over the last decade have reported declines in amphibian populations in areas of pristine habitat. Such reports suggest the role of indirect factors and a global effect of human activities on natural systems. Declines in amphibian populations bear significant implications for the functioning of many terrestrial ecosystems, and may signify important implications for human welfare. A wide range of candidates have been proposed to explain amphibian population declines. However, it seems likely that the relevance of each factor is dependent upon the habitat type and species in question, and that complex synergistic effects between a number of environmental factors is of critical importance. Monitoring of amphibian populations to assess the extent and cause of declines is confounded by a number of ecological and methodological limitations.

  2. When can the cause of a population decline be determined?

    Hefley, Trevor J.; Hooten, Mevin B.; Drake, John M.; Russell, Robin E.; Walsh, Daniel P.


    Inferring the factors responsible for declines in abundance is a prerequisite to preventing the extinction of wild populations. Many of the policies and programmes intended to prevent extinctions operate on the assumption that the factors driving the decline of a population can be determined. Exogenous factors that cause declines in abundance can be statistically confounded with endogenous factors such as density dependence. To demonstrate the potential for confounding, we used an experiment where replicated populations were driven to extinction by gradually manipulating habitat quality. In many of the replicated populations, habitat quality and density dependence were confounded, which obscured causal inference. Our results show that confounding is likely to occur when the exogenous factors that are driving the decline change gradually over time. Our study has direct implications for wild populations, because many factors that could drive a population to extinction change gradually through time.

  3. Neighborhood Decline and the Economic Crisis (discussion paper)

    Zwiers, M.D.; Bolt, G.; Van Ham, M.; Van Kempen, R.


    Neighborhood decline is a complex and multidimensional process. National and regional variation in economic and political structures (including variety in national welfare state arrangements), combined with differences in neighborhood history, development and population composition, makes it

  4. U.S. Cancer Deaths Decline Over Three Decades

    ... page: U.S. Cancer Deaths Decline Over Three Decades But clusters ... Medicine, the National Institutes of Health, or the U.S. Department of Health and Human Services. More Health ...

  5. Where Medical Pot Is Legal, Fatal Car Crashes Often Decline

    ... 162675.html Where Medical Pot Is Legal, Fatal Car Crashes Often Decline It's possible that these state ... and Human Services. More Health News on: Marijuana Motor Vehicle Safety Recent Health News Related MedlinePlus Health ...

  6. Episodic Memory Decline in Huntington's Disease, A Binding Deficit?

    El Haj, M.; Caillaud, M.; Fasotti, L.; Verny, C.; Allain, P.


    Background: Huntington's disease (HD) is characterized by episodic memory deterioration. Objective: Our paper investigates the cognitive mechanisms that might underlie this decline. To this aim, we tested two executive hypotheses, the binding and the inhibition hypotheses. Methods: Fifteen HD patien


    Alien species (also referred to as exotic, invasive, introduced, or normative species) have been implicated as causal agents in population declines of many amphibian species. Herein, we evaluate the relative contributions of alien species and other factors in adversely affecting ...

  8. Molecular survey of the Texas Phoenix decline phytoplasma ...


    symptoms of Texas Phoenix decline (TPD) in West Central Florida. The IGS region was .... DNA from a healthy plant, and a water control (no DNA template). The PCR .... supplement sequencing data which may be subject to sequencing errors.

  9. Longitudinal Decline in Lung Function Measurements among Saskatchewan Grain Workers

    Punam Pahwa


    Full Text Available OBJECTIVE: To evaluate the relationship between the long term effects of grain dust and decline in lung function among grain elevator workers in Saskatchewan, studied over a 15-year period.

  10. Hospital marketing: strategy reassessment in a declining market.

    Van Doren, D C; Spielman, A P


    Despite continued significant increases in the nation's spending for health care, use of inpatient hospital services has declined. The authors use the product life cycle to analyze the market for inpatient hospital services and to examine competitive strategies for hospital marketing success. The product life cycle literature suggests at least four strategies for products in decline. The authors analyze the advantages and disadvantages of these strategies as they relate to the hospital market.

  11. The Soviet economic decline : historical and republican data

    Easterly, William; Fischer, Stanley; DEC


    Soviet growth for 1960-89 was the worst in the world, after controlling for investment and human capital. And relative performance worsens over time. The authors explain the declining Soviet growth rate from 1950 to 1987 by the declining marginal product of capital. The rate of total factor productivity growth is roughly constant over that period. Although the Soviet slowdown has conventionally been attributed to extensive growth (rising capital-to-output ratios), extensive growth is also a f...

  12. The Soviet Economic Decline: Historical and Republican Data

    William Easterly; Stanley Fischer


    Soviet growth over 1960-89 was the worst in the world after we control for investment and human capital; the relative performance worsens over time. The declining Soviet growth rate over 1950-87 is explained by the declining marginal product of capital; the rate of TFP growth is roughly constant over that period. While the Soviet slowdown has conventionally been attributed to extensive growth (rising capital to output ratios), extensive growth is also a feature of market-oriented economies li...

  13. Wild Pigs: inciting factor in southern pine decline?

    Lori G. Eckhardt; Roger D. Menard; Stephen S. Ditchkoff


    During an investigation into southern pine decline at Fort Benning Georgia, the possibility of wild pigs (Sus scrofa) as an inciting factor became evident. Their rooting activity caused significant root damage on sites showing symptoms of pine decline. It was thought that perhaps the pigs may be moving around pathogenic fungi during their rooting activity in Pinus...

  14. The historical decline of fertility in Eastern Europe.

    Leasure, J W


    Quantitative data from the Princeton European Fertility Project were used to explain the determinants of change in attitudes which lead to use of birth control within marriage and fertility decline in terms of the growth of autonomy over one's political, personal, religious, economic, and reproductive life. The following countries, which are arranged by their chronological order of marital fertility decline, were used in the primarily quantitative analysis: Hungary, Czechoslovakia, Greece, Yugoslavia, Poland, Romania, Bulgaria, and Albania. Prior research had identified an association between a decline in the birth rate and the presence of revolutions nationalist independence movements, or democratic reform movements. The connection is that once control over one's political and economic destiny is made, there is an extension into one's reproductive behavior. Further refinement has occurred. Autonomy is grounded in reason, the natural rights of individuals, and independence of thought. Reflective of this autonomous spirit were affiliations with Congregational, Presbyterian, Quaker, Unitarian, and Universalist religions. The present analysis is historical and describes the events surrounding the decline in marital fertility. These events might have preceded, been concurrent with, or followed the decline, but the thesis remains that the growth in autonomy contributes to political changes and fertility decline. The primary measure of fertility is Ig developed by Coale, and sustained decline maps of Coale and Watkins. Crude birth rate and total fertility rate were also used. the provincial analysis was impeded by lack of long time series for some countries and boundary changes. The hypothesis is generally supported, except in the case of Yugoslavia which varies too much. Support for the thesis was stronger in some countries than in others. Sustained decline occurred by each country in different periods, e.g., in Hungary it began between 1850-60 while in Albania it began

  15. Economic reasons behind the decline of the Ottoman empire

    Duranoglu, Erkut; Okutucu, Guzide


    This study addresses the economic reasons of the decline and fall of the Ottoman Empire. On the contrary to the previous researches, by undertaking both global and domestic developments, the paper examines the decline of the empire from an economical point of perspective. Although international developments such as industrialization in European countries, pressure on the Ottomans in terms of integrating with the world economy, global economic factors like depressions and war...

  16. The Prediction of Maximum Amplitudes of Solar Cycles and the Maximum Amplitude of Solar Cycle 24


    We present a brief review of predictions of solar cycle maximum ampli-tude with a lead time of 2 years or more. It is pointed out that a precise predictionof the maximum amplitude with such a lead-time is still an open question despiteprogress made since the 1960s. A method of prediction using statistical character-istics of solar cycles is developed: the solar cycles are divided into two groups, ahigh rising velocity (HRV) group and a low rising velocity (LRV) group, dependingon the rising velocity in the ascending phase for a given duration of the ascendingphase. The amplitude of Solar Cycle 24 can be predicted after the start of thecycle using the formula derived in this paper. Now, about 5 years before the startof the cycle, we can make a preliminary prediction of 83.2-119.4 for its maximumamplitude.

  17. Autobiographical memory decline in Alzheimer’s Disease

    EL HAJ, Mohamad; Antoine, Pascal; Nandrino, Jean-Louis; Kapogiannis, Dimitrios


    Autobiographical memory, or memory for personal experiences, allows individuals to define themselves and construct a meaningful life story. Decline of this ability, as observed in Alzheimer’s Disease (AD), results in an impaired sense of self and identity. We present a critical review of theories and findings regarding cognitive and neuroanatomical underpinnings of autobiographical memory and its decline in AD and highlight studies on its clinical rehabilitation. We propose that autobiographical recall in AD is mainly characterized by loss of associated episodic information, which leads to de-contextualisation of autobiographical memories and a shift from reliving past events to a general sense of familiarity. This decline refers to retrograde, but also anterograde amnesia that affects newly acquired memories besides remote ones. One consequence of autobiographical memory decline in AD is decreased access to memories that shape self-consciousness, self-knowledge, and self-images, leading to a diminished sense of self and identity. The link between autobiographical decline and compromised sense of self in AD can also manifest itself as low correspondence and coherence between past memories and current goals and beliefs. By linking cognitive, neuroanatomical, and clinical aspects of autobiographical decline in AD, our review provides a theoretical foundation, which may lead to better rehabilitation strategies. PMID:26876367

  18. The cause of global amphibian declines: a developmental endocrinologist's perspective.

    Hayes, T B; Falso, P; Gallipeau, S; Stice, M


    Greater than 70% of the world's amphibian species are in decline. We propose that there is probably not a single cause for global amphibian declines and present a three-tiered hierarchical approach that addresses interactions among and between ultimate and proximate factors that contribute to amphibian declines. There are two immediate (proximate) causes of amphibian declines: death and decreased recruitment (reproductive failure). Although much attention has focused on death, few studies have addressed factors that contribute to declines as a result of failed recruitment. Further, a great deal of attention has focused on the role of pathogens in inducing diseases that cause death, but we suggest that pathogen success is profoundly affected by four other ultimate factors: atmospheric change, environmental pollutants, habitat modification and invasive species. Environmental pollutants arise as likely important factors in amphibian declines because they have realized potential to affect recruitment. Further, many studies have documented immunosuppressive effects of pesticides, suggesting a role for environmental contaminants in increased pathogen virulence and disease rates. Increased attention to recruitment and ultimate factors that interact with pathogens is important in addressing this global crisis.

  19. Minimal models of growth and decline of microbial populations.

    Juška, Alfonsas


    Dynamics of growth and decline of microbial populations were analysed and respective models were developed in this investigation. Analysis of the dynamics was based on general considerations concerning the main properties of microorganisms and their interactions with the environment which was supposed to be affected by the activity of the population. Those considerations were expressed mathematically by differential equations or systems of the equations containing minimal sets of parameters characterizing those properties. It has been found that: (1) the factors leading to the decline of the population have to be considered separately, namely, accumulation of metabolites (toxins) in the medium and the exhaustion of resources; the latter have to be separated again into renewable ('building materials') and non-renewable (sources of energy); (2) decline of the population is caused by the exhaustion of sources of energy but no decline is predicted by the model because of the exhaustion of renewable resources; (3) the model determined by the accumulation of metabolites (toxins) in the medium does not suggest the existence of a separate 'stationary phase'; (4) in the model determined by the exhaustion of energy resources the 'stationary' and 'decline' phases are quite discernible; and (5) there is no symmetry in microbial population dynamics, the decline being slower than the rise. Mathematical models are expected to be useful in getting insight into the process of control of the dynamics of microbial populations. The models are in agreement with the experimental data.

  20. Trajectory of Mobility Decline by Type of Dementia.

    Tolea, Magdalena I; Morris, John C; Galvin, James E


    Cognitive and physical aspects of functionality are closely related. However, whether physical decline differs by dementia type and progression rate is debatable. To address these issues, we conducted a longitudinal study of 766 older adults whose physical performance and cognitive status were assessed annually with standard assessment tools [eg, Physical Performance Test, Clinical Dementia Rate (CDR)] for 8 years. Compared with participants who remained cognitively normal, those progressing to later-stage dementia (CDR=1) declined in their mobility by a factor of 2.82 (Pdementia (slope=-1.20, Pdementia (slope=-0.39, P=0.038) suggesting a steeper physical decline with dementia progression, particularly in those with the fastest disease progression. Although all types of dementia experienced mobility decline, those progressing to non-Alzheimer disease (AD) dementias, especially vascular dementia declined faster than those who remained normal (slope=-2.70, Pdementia patients particularly those with non-AD subtypes should be targeted for interventions to maintain or improve gait/balance and prevent functional decline and disability although AD patients may also benefit.

  1. CMB Maximum Temperature Asymmetry Axis: Alignment with Other Cosmic Asymmetries

    Mariano, Antonio


    We use a global pixel based estimator to identify the axis of the residual Maximum Temperature Asymmetry (MTA) (after the dipole subtraction) of the WMAP 7 year Internal Linear Combination (ILC) CMB temperature sky map. The estimator is based on considering the temperature differences between opposite pixels in the sky at various angular resolutions (4 degrees-15 degrees and selecting the axis that maximizes this difference. We consider three large scale Healpix resolutions (N_{side}=16 (3.7 degrees), N_{side}=8 (7.3 degrees) and N_{side}=4 (14.7 degrees)). We compare the direction and magnitude of this asymmetry with three other cosmic asymmetry axes (\\alpha dipole, Dark Energy Dipole and Dark Flow) and find that the four asymmetry axes are abnormally close to each other. We compare the observed MTA axis with the corresponding MTA axes of 10^4 Gaussian isotropic simulated ILC maps (based on LCDM). The fraction of simulated ILC maps that reproduces the observed magnitude of the MTA asymmetry and alignment wit...

  2. Mixed integer linear programming for maximum-parsimony phylogeny inference.

    Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell


    Reconstruction of phylogenetic trees is a fundamental problem in computational biology. While excellent heuristic methods are available for many variants of this problem, new advances in phylogeny inference will be required if we are to be able to continue to make effective use of the rapidly growing stores of variation data now being gathered. In this paper, we present two integer linear programming (ILP) formulations to find the most parsimonious phylogenetic tree from a set of binary variation data. One method uses a flow-based formulation that can produce exponential numbers of variables and constraints in the worst case. The method has, however, proven extremely efficient in practice on datasets that are well beyond the reach of the available provably efficient methods, solving several large mtDNA and Y-chromosome instances within a few seconds and giving provably optimal results in times competitive with fast heuristics than cannot guarantee optimality. An alternative formulation establishes that the problem can be solved with a polynomial-sized ILP. We further present a web server developed based on the exponential-sized ILP that performs fast maximum parsimony inferences and serves as a front end to a database of precomputed phylogenies spanning the human genome.

  3. [A decline in the French demographic situation in the context of a Europe also in demographic decline].

    Calot, G


    The author analyzes the decline in French fertility which has occurred over the past two years using data from official sources. Some comparisons are made with fertility trends in other European countries.

  4. Pattern formation, logistics, and maximum path probability

    Kirkaldy, J. S.


    The concept of pattern formation, which to current researchers is a synonym for self-organization, carries the connotation of deductive logic together with the process of spontaneous inference. Defining a pattern as an equivalence relation on a set of thermodynamic objects, we establish that a large class of irreversible pattern-forming systems, evolving along idealized quasisteady paths, approaches the stable steady state as a mapping upon the formal deductive imperatives of a propositional function calculus. In the preamble the classical reversible thermodynamics of composite systems is analyzed as an externally manipulated system of space partitioning and classification based on ideal enclosures and diaphragms. The diaphragms have discrete classification capabilities which are designated in relation to conserved quantities by descriptors such as impervious, diathermal, and adiabatic. Differentiability in the continuum thermodynamic calculus is invoked as equivalent to analyticity and consistency in the underlying class or sentential calculus. The seat of inference, however, rests with the thermodynamicist. In the transition to an irreversible pattern-forming system the defined nature of the composite reservoirs remains, but a given diaphragm is replaced by a pattern-forming system which by its nature is a spontaneously evolving volume partitioner and classifier of invariants. The seat of volition or inference for the classification system is thus transferred from the experimenter or theoretician to the diaphragm, and with it the full deductive facility. The equivalence relations or partitions associated with the emerging patterns may thus be associated with theorems of the natural pattern-forming calculus. The entropy function, together with its derivatives, is the vehicle which relates the logistics of reservoirs and diaphragms to the analog logistics of the continuum. Maximum path probability or second-order differentiability of the entropy in isolation are

  5. Evaluation of long-term water-level declines in basalt aquifers near Mosier, Oregon

    Burns, Erick R.; Morgan, David S.; Lee, Karl K.; Haynes, Jonathan V.; Conlon, Terrence D.


    are not sustainable, (2) well construction practices that have resulted in leakage from aquifers into springs and streams, and (3) reduction in aquifer recharge resulting from long-term climate variations. Historical well construction practices, specifically open, unlined, uncased boreholes that result in cross-connecting (or commingling) multiple aquifers, allow water to flow between these aquifers. Water flowing along the path of least resistance, through commingled boreholes, allows the drainage of aquifers that previously stored water more efficiently. The study area is in the eastern foothills of the Cascade Range in north central Oregon in a transitional zone between the High Cascades to the west and the Columbia Plateau to the east. The 78-square mile (mi2) area is defined by the drainages of three streams - Mosier Creek (51.8 mi2), Rock Creek (13.9 mi2), and Rowena Creek (6.9 mi2) - plus a small area that drains directly to the Columbia River.The three major components of the study are: (1) a 2-year intensive data collection period to augment previous streamflow and groundwater-level measurements, (2) precipitation-runoff modeling of the watersheds to determine the amount of recharge to the aquifer system, and (3) groundwater-flow modeling and analysis to evaluate the cause of groundwater-level declines and to evaluate possible water resource management strategies. Data collection included the following: 1. Water-level measurements were made in 37 wells. Bi-monthly or quarterly measurements were made in 30 wells, and continuous water-level monitoring instruments were installed in 7 wells. The measurements principally were made to capture the seasonal patterns in the groundwater system, and to augment the available long-term record. 2. Groundwater pumping was measured, reported, or estimated from irrigation, municipal and domestic wells. Flowmeters were installed on 74 percent of all high-capacity irrigation wells in the study area. 3. Borehole geophysical data

  6. The Optimum Plate to Plate Spacing for Maximum Heat Transfer Rate from a Flat Plate Type Heat Exchanger

    Ambarita, Himsar; Kishinami, Koki; Daimaruya, Mashashi; Tokura, Ikuo; Kawai, Hideki; Suzuki, Jun; Kobiyama, Mashayosi; Ginting, Armansyah

    The present paper is a study on the optimum plate to plate spacing for maximum heat transfer rate from a flat plate type heat exchanger. The heat exchanger consists of a number of parallel flat plates. The working fluids are flowed at the same operational conditions, either fixed pressure head or fixed fan power input. Parallel and counter flow directions of the working fluids were considered. While the volume of the heat exchanger is kept constant, plate number was varied. Hence, the spacing between plates as well as heat transfer rate will vary and there exists a maximum heat transfer rate. The objective of this paper is to seek the optimum plate to plate spacing for maximum heat transfer rate. In order to solve the problem, analytical and numerical solutions have been carried out. In the analytical solution, the correlations of the optimum plate to plate spacing as a function of the non-dimensional parameters were developed. Furthermore, the numerical simulation is carried out to evaluate the correlations. The results show that the optimum plate to plate spacing for a counter flow heat exchanger is smaller than parallel flow ones. On the other hand, the maximum heat transfer rate for a counter flow heat exchanger is bigger than parallel flow ones.

  7. Optimum air-demand ratio for maximum aeration efficiency in high-head gated circular conduits.

    Ozkan, Fahri; Tuna, M Cihat; Baylar, Ahmet; Ozturk, Mualla


    Oxygen is an important component of water quality and its ability to sustain life. Water aeration is the process of introducing air into a body of water to increase its oxygen saturation. Water aeration can be accomplished in a variety of ways, for instance, closed-conduit aeration. High-speed flow in a closed conduit involves air-water mixture flow. The air flow results from the subatmospheric pressure downstream of the gate. The air entrained by the high-speed flow is supplied by the air vent. The air entrained into the flow in the form of a large number of bubbles accelerates oxygen transfer and hence also increases aeration efficiency. In the present work, the optimum air-demand ratio for maximum aeration efficiency in high-head gated circular conduits was studied experimentally. Results showed that aeration efficiency increased with the air-demand ratio to a certain point and then aeration efficiency did not change with a further increase of the air-demand ratio. Thus, there was an optimum value for the air-demand ratio, depending on the Froude number, which provides maximum aeration efficiency. Furthermore, a design formula for aeration efficiency was presented relating aeration efficiency to the air-demand ratio and Froude number.

  8. The effect of maximum open height on operating characteristics of polymer injected pump poppet valve

    Zhang, S. C.; Chen, X. D.; Deng, H. Y.


    Reciprocating polymer injected pump is the key injection equipment of tertiary oil recovery, the poppet valve in it exists the problem of large vibration noise, low efficiency and short life when transportation high viscosity medium. So the CFD technique is adopted to simulate and analyze the inner flow fields of fluid end poppet valve. According to the practical structure of the poppet valve, a simplified 2D axis-symmetry geometry model of the flow field is established. Combined with pump speed, plunger stroke and plunger diameter, given the boundary condition of the inlet valve, then the numerical simulation of flow field under six different maximum open heights is done depending on software Fluent. The relationship between open height to valve gap flow velocity, hydraulic loss and lag angle is obtained. The results indicate that, with the increase of open height, the valve gap flow velocity decreases, inlet outlet pressure differential decreases and hydraulic loss decreases. But the lag angle is continuously increasing with the increase of maximum open height, the valve has a good work performance when the open height is 1, 1.5, 2, 2.5, 3mm, but when it reaches 3.5mm, the valve performance becomes poor. The study can offer certain reference to understand operating characteristics of poppet valve, help to reduce the hydraulic losses and raise volume efficiency of the pump.

  9. Menopause Is Associated with Accelerated Lung Function Decline.

    Triebner, Kai; Matulonga, Bobette; Johannessen, Ane; Suske, Sandra; Benediktsdóttir, Bryndís; Demoly, Pascal; Dharmage, Shyamali C; Franklin, Karl A; Garcia-Aymerich, Judith; Gullón Blanco, José Antonio; Heinrich, Joachim; Holm, Mathias; Jarvis, Debbie; Jõgi, Rain; Lindberg, Eva; Moratalla Rovira, Jesús Martínez; Muniozguren Agirre, Nerea; Pin, Isabelle; Probst-Hensch, Nicole; Puggini, Luca; Raherison, Chantal; Sánchez-Ramos, José Luis; Schlünssen, Vivi; Sunyer, Jordi; Svanes, Cecilie; Hustad, Steinar; Leynaert, Bénédicte; Gómez Real, Francisco


    Menopause is associated with changes in sex hormones, which affect immunity, inflammation, and osteoporosis and may impair lung function. Lung function decline has not previously been investigated in relation to menopause. To study whether lung function decline, assessed by FVC and FEV1, is accelerated in women who undergo menopause. The population-based longitudinal European Community Respiratory Health Survey provided serum samples, spirometry, and questionnaire data about respiratory and reproductive health from three study waves (n = 1,438). We measured follicle-stimulating hormone and luteinizing hormone and added information on menstrual patterns to determine menopausal status using latent class analysis. Associations with lung function decline were investigated using linear mixed effects models, adjusting for age, height, weight, pack-years, current smoking, age at completed full-time education, spirometer, and including study center as random effect. Menopausal status was associated with accelerated lung function decline. The adjusted mean FVC decline was increased by -10.2 ml/yr (95% confidence interval [CI], -13.1 to -7.2) in transitional women and -12.5 ml/yr (95% CI, -16.2 to -8.9) in post-menopausal women, compared with women menstruating regularly. The adjusted mean FEV1 decline increased by -3.8 ml/yr (95% CI, -6.3 to -2.9) in transitional women and -5.2 ml/yr (95% CI, -8.3 to -2.0) in post-menopausal women. Lung function declined more rapidly among transitional and post-menopausal women, in particular for FVC, beyond the expected age change. Clinicians should be aware that respiratory health often deteriorates during reproductive aging.

  10. Functional network integrity presages cognitive decline in preclinical Alzheimer disease.

    Buckley, Rachel F; Schultz, Aaron P; Hedden, Trey; Papp, Kathryn V; Hanseeuw, Bernard J; Marshall, Gad; Sepulcre, Jorge; Smith, Emily E; Rentz, Dorene M; Johnson, Keith A; Sperling, Reisa A; Chhatwal, Jasmeer P


    To examine the utility of resting-state functional connectivity MRI (rs-fcMRI) measurements of network integrity as a predictor of future cognitive decline in preclinical Alzheimer disease (AD). A total of 237 clinically normal older adults (aged 63-90 years, Clinical Dementia Rating 0) underwent baseline β-amyloid (Aβ) imaging with Pittsburgh compound B PET and structural and rs-fcMRI. We identified 7 networks for analysis, including 4 cognitive networks (default, salience, dorsal attention, and frontoparietal control) and 3 noncognitive networks (primary visual, extrastriate visual, motor). Using linear and curvilinear mixed models, we used baseline connectivity in these networks to predict longitudinal changes in preclinical Alzheimer cognitive composite (PACC) performance, both alone and interacting with Aβ burden. Median neuropsychological follow-up was 3 years. Baseline connectivity in the default, salience, and control networks predicted longitudinal PACC decline, unlike connectivity in the dorsal attention and all noncognitive networks. Default, salience, and control network connectivity was also synergistic with Aβ burden in predicting decline, with combined higher Aβ and lower connectivity predicting the steepest curvilinear decline in PACC performance. In clinically normal older adults, lower functional connectivity predicted more rapid decline in PACC scores over time, particularly when coupled with increased Aβ burden. Among examined networks, default, salience, and control networks were the strongest predictors of rate of change in PACC scores, with the inflection point of greatest decline beyond the fourth year of follow-up. These results suggest that rs-fcMRI may be a useful predictor of early, AD-related cognitive decline in clinical research settings. © 2017 American Academy of Neurology.

  11. Subjective cognitive decline: The first clinical manifestation of Alzheimer's disease?

    Adalberto Studart Neto

    Full Text Available ABSTRACT Background: Mild cognitive impairment is considered as the first clinical manifestation of Alzheimer's disease (AD, when the individual exhibits below performance on standardized neuropsychological tests. However, some subjects before having a lower performance on cognitive assessments already have a subjective memory complaint. Objective: A review about subjective cognitive decline, the association with AD biomarkers and risk of conversion to dementia. Methods: We performed a comprehensive non-systematic review on PubMed. The keywords used in the search were terms related to subjective cognitive decline. Results: Subjective cognitive decline is characterized by self-experience of deterioration in cognitive performance not detected objectively through formal neuropsychological testing. However, various terms and definitions have been used in the literature and the lack of a widely accepted concept hampers comparison of studies. Epidemiological data have shown that individuals with subjective cognitive decline are at increased risk of progression to AD dementia. In addition, there is evidence that this group has a higher prevalence of positive biomarkers for amyloidosis and neurodegeneration. However, Alzheimer's disease is not the only cause of subjective cognitive decline and various other conditions can be associated with subjective memory complaints, such as psychiatric disorders or normal aging. The features suggestive of a neurodegenerative disorder are: onset of decline within the last five years, age at onset above 60 years, associated concerns about decline and confirmation by an informant. Conclusion: These findings support the idea that subjective cognitive complaints may be an early clinical marker that precedes mild cognitive impairment due to Alzheimer's disease.

  12. Cardiorespiratory Fitness of Inmates of a Maximum Security Prison ...


    Maximum Security Prison; and also to determine the effects of age, gender, and period of incarceration on CRF. A total of 247 apparently healthy inmates of Maiduguri Maximum Security ... with different types of cardiovascular and metabolic.

  13. Maximum likelihood polynomial regression for robust speech recognition

    LU Yong; WU Zhenyang


    The linear hypothesis is the main disadvantage of maximum likelihood linear re- gression (MLLR). This paper applies the polynomial regression method to model adaptation and establishes a nonlinear model adaptation algorithm using maximum likelihood polyno

  14. Numerical optimization using flow equations.

    Punk, Matthias


    We develop a method for multidimensional optimization using flow equations. This method is based on homotopy continuation in combination with a maximum entropy approach. Extrema of the optimizing functional correspond to fixed points of the flow equation. While ideas based on Bayesian inference such as the maximum entropy method always depend on a prior probability, the additional step in our approach is to perform a continuous update of the prior during the homotopy flow. The prior probability thus enters the flow equation only as an initial condition. We demonstrate the applicability of this optimization method for two paradigmatic problems in theoretical condensed matter physics: numerical analytic continuation from imaginary to real frequencies and finding (variational) ground states of frustrated (quantum) Ising models with random or long-range antiferromagnetic interactions.

  15. Little impact of the Three Gorges Dam on recent decadal lake decline across China's Yangtze Plain

    Wang, Jida; Sheng, Yongwei; Wada, Yoshihide


    The ubiquitous lakes across China's Yangtze Plain (YP) are indispensable freshwater resources sustaining ecosystems and socioeconomics for nearly half a billion people. Our recent survey revealed a widespread net decline in the total YP lake inundation area during 2000-2011 (a cumulative decrease of ˜10%), yet its mechanism remained contentious. Here we uncover the impacts of climate variability and anthropogenic activities including (i) Yangtze flow and sediment alterations by the Three Gorges Dam (TGD) and (ii) human water consumption in agricultural, industrial, and domestic sectors throughout the downstream Yangtze Basin. Results suggest that climate variability is the dominant driver of this decadal lake decline, whereas studied human activities, despite varying seasonal impacts that peak in fall, contribute marginal fraction (˜10-20% or less) to the interannual lake area decrease. Given that the TGD impacts on the total YP lake area and its seasonal variation are both under ˜5%, we also dismiss the speculation that the TGD might be responsible for evident downstream climate change by altering lake surface extent and thus open water evaporation. Nevertheless, anthropogenic impacts exhibited a strengthening trend during the past decade. Although the TGD has reached its full-capacity water regulation, the negative impacts of human water consumption and TGD-induced net channel erosion, which are already comparable to that of TGD's flow regulation, may continue to grow as crucial anthropogenic factors to future YP lake conservation.

  16. Flow visualization

    Merzkirch, Wolfgang


    Flow Visualization describes the most widely used methods for visualizing flows. Flow visualization evaluates certain properties of a flow field directly accessible to visual perception. Organized into five chapters, this book first presents the methods that create a visible flow pattern that could be investigated by visual inspection, such as simple dye and density-sensitive visualization methods. It then deals with the application of electron beams and streaming birefringence. Optical methods for compressible flows, hydraulic analogy, and high-speed photography are discussed in other cha

  17. Communication: Maximum caliber is a general variational principle for nonequilibrium statistical mechanics.

    Hazoglou, Michael J; Walther, Valentin; Dixit, Purushottam D; Dill, Ken A


    There has been interest in finding a general variational principle for non-equilibrium statistical mechanics. We give evidence that Maximum Caliber (Max Cal) is such a principle. Max Cal, a variant of maximum entropy, predicts dynamical distribution functions by maximizing a path entropy subject to dynamical constraints, such as average fluxes. We first show that Max Cal leads to standard near-equilibrium results—including the Green-Kubo relations, Onsager's reciprocal relations of coupled flows, and Prigogine's principle of minimum entropy production—in a way that is particularly simple. We develop some generalizations of the Onsager and Prigogine results that apply arbitrarily far from equilibrium. Because Max Cal does not require any notion of "local equilibrium," or any notion of entropy dissipation, or temperature, or even any restriction to material physics, it is more general than many traditional approaches. It also applicable to flows and traffic on networks, for example.

  18. Statistical optimization for passive scalar transport: maximum entropy production vs. maximum Kolmogorov–Sinay entropy

    M. Mihelich


    Full Text Available We derive rigorous results on the link between the principle of maximum entropy production and the principle of maximum Kolmogorov–Sinai entropy using a Markov model of the passive scalar diffusion called the Zero Range Process. We show analytically that both the entropy production and the Kolmogorov–Sinai entropy seen as functions of f admit a unique maximum denoted fmaxEP and fmaxKS. The behavior of these two maxima is explored as a function of the system disequilibrium and the system resolution N. The main result of this article is that fmaxEP and fmaxKS have the same Taylor expansion at first order in the deviation of equilibrium. We find that fmaxEP hardly depends on N whereas fmaxKS depends strongly on N. In particular, for a fixed difference of potential between the reservoirs, fmaxEP(N tends towards a non-zero value, while fmaxKS(N tends to 0 when N goes to infinity. For values of N typical of that adopted by Paltridge and climatologists (N ≈ 10 ~ 100, we show that fmaxEP and fmaxKS coincide even far from equilibrium. Finally, we show that one can find an optimal resolution N* such that fmaxEP and fmaxKS coincide, at least up to a second order parameter proportional to the non-equilibrium fluxes imposed to the boundaries. We find that the optimal resolution N* depends on the non equilibrium fluxes, so that deeper convection should be represented on finer grids. This result points to the inadequacy of using a single grid for representing convection in climate and weather models. Moreover, the application of this principle to passive scalar transport parametrization is therefore expected to provide both the value of the optimal flux, and of the optimal number of degrees of freedom (resolution to describe the system.

  19. 20 CFR 617.14 - Maximum amount of TRA.


    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Maximum amount of TRA. 617.14 Section 617.14... FOR WORKERS UNDER THE TRADE ACT OF 1974 Trade Readjustment Allowances (TRA) § 617.14 Maximum amount of TRA. (a) General rule. Except as provided under paragraph (b) of this section, the maximum amount of...

  20. 40 CFR 94.107 - Determination of maximum test speed.


    ... specified in 40 CFR 1065.510. These data points form the lug curve. It is not necessary to generate the... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Determination of maximum test speed... Determination of maximum test speed. (a) Overview. This section specifies how to determine maximum test...

  1. 14 CFR 25.1505 - Maximum operating limit speed.


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not...

  2. Maximum Performance Tests in Children with Developmental Spastic Dysarthria.

    Wit, J.; And Others


    Three Maximum Performance Tasks (Maximum Sound Prolongation, Fundamental Frequency Range, and Maximum Repetition Rate) were administered to 11 children (ages 6-11) with spastic dysarthria resulting from cerebral palsy and 11 controls. Despite intrasubject and intersubject variability in normal and pathological speakers, the tasks were found to be…

  3. Maximum physical capacity testing in cancer patients undergoing chemotherapy

    Knutsen, L.; Quist, M; Midtgaard, J


    BACKGROUND: Over the past few years there has been a growing interest in the field of physical exercise in rehabilitation of cancer patients, leading to requirements for objective maximum physical capacity measurement (maximum oxygen uptake (VO(2max)) and one-repetition maximum (1RM)) to determine...

  4. Particle retention in porous media: Applications to water injectivity decline

    Wennberg, Kjell Erik


    This thesis studies the problem of migration and deposition of colloidal particles within porous media, theoretically and by computerized simulation. Special emphasis is put on the prediction of injectivity decline in water injection wells due to inherent particles in the injection water. The study of particle deposition within porous media requires a correct prediction of the deposition rate or filtration coefficient. A thorough review of the modeling approaches used in the past are combined with new ideas in order to arrive at an improved model for the prediction of the filtration coefficient. A new way of determining the transition time for the dominant deposition mechanism to change from internal deposition to external cake formation is proposed. From this fundamental theory, equations are given for water injectivity decline predictions. A computer program called WID for water injectivity decline predictions was developed. Using water quality, formation properties, injection rate/pressure and completion information as input, WID predicts decline in vertical and horizontal injection wells with openhole, perforated and fractured completions. The calculations agree fairly well with field data; in some cases the agreement is excellent. A poor match in a few cases indicates that more mechanisms may be responsible for injectivity decline than those presently accounted for by the simulator. The second part of the study deals with a theoretical investigation of the multi-dimensional nature of particle deposition in porous media. 112 refs., 100 figs., 9 tabs.

  5. Global amphibian declines: perspectives from the United States and beyond

    Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.


    Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed for amphibian declines. Still other underlying factors may include infectious diseases caused by the chytrid fungus Batrachochytrium dendrobatidis, pathogenic viruses (Ranavirus), and other agents. It is nearly certain that more than one etiology is to blame for the majority of the global amphibian declines, and that these causal factors include some combination of climatological or physical habitat destabilization and infectious disease, most notably chytridiomycosis. Scientific research efforts are aimed at elucidating these etiologies on local, regional, and global scales that we might better understand and counteract the driving forces behind amphibian declines. Conservation efforts as outlined in the Amphibian Conservation Action Plan of 2005 are also being made to curtail losses and prevent further extinctions wherever possible.

  6. Factors affecting the decline of ventilatory function in chronic bronchitis

    Campbell, A.H.; Barter, C.E.; O' Connell, J.M.; Huggins, R.


    Ninety six middle aged male patients with chronic bronchitis with relatively well preserved ventilatory function who were resident in Queensland, New South Wales, or Victoria took part in a prospective study to determine the relationship of various factors to the rate of decline of the Forced Expiratory Volume (FEV1). Thirty of the subjects withdrew, leaving 66 to be followed for four to six years. The mean rate of decline of the Forced Expiratory Volume (FEV1) was 58.6 ml/year. The subjects ventilatory responses to bronchodilator and to methacholine were significantly related to each other and to sputum eosinophilia. With a linear model for the data on 57 patients who had methacholine and skin tests the rate of decline of the FEV1 was found, after adjustment had been made for other variables, to be significantly related to state of residence, current smoking, response to bronchodilator, age, and occupational exposure to dust. Response to bronchodilator was interchangeable with response to methacholine. When data from all 66 subjects were introduced into the model, in addition to the five significant individual variables (FEV1/VC% X response to bronchodilator) was significantly related to the rate of decline of the FEV1. Of these prognostic indices, response to bronchodilator was independent of the initial FEV1, FEV/VC%, and FEV1% predicted. The difference between states, which was not explained by differences due to sampling or withdrawal of subjects, was due to a low rate of decline in Queensland.

  7. Detecting insect pollinator declines on regional and global scales

    Lubuhn, Gretchen; Droege, Sam; Connor, Edward F.; Gemmill-Herren, Barbara; Potts, Simon G.; Minckley, Robert L.; Griswold, Terry; Jean, Robert; Kula, Emanuel; Roubik, David W.; Cane, Jim; Wright, Karen W.; Frankie, Gordon; Parker, Frank


    Recently there has been considerable concern about declines in bee communities in agricultural and natural habitats. The value of pollination to agriculture, provided primarily by bees, is >$200 billion/year worldwide, and in natural ecosystems it is thought to be even greater. However, no monitoring program exists to accurately detect declines in abundance of insect pollinators; thus, it is difficult to quantify the status of bee communities or estimate the extent of declines. We used data from 11 multiyear studies of bee communities to devise a program to monitor pollinators at regional, national, or international scales. In these studies, 7 different methods for sampling bees were used and bees were sampled on 3 different continents. We estimated that a monitoring program with 200-250 sampling locations each sampled twice over 5 years would provide sufficient power to detect small (2-5%) annual declines in the number of species and in total abundance and would cost U.S.$2,000,000. To detect declines as small as 1% annually over the same period would require >300 sampling locations. Given the role of pollinators in food security and ecosystem function, we recommend establishment of integrated regional and international monitoring programs to detect changes in pollinator communities.

  8. Segmentation d'images par l'algorithme des flot maximum continu


    In recent years, with the advance of computing equipment and image acquisition techniques, the sizes, dimensions and content of acquired images have increased considerably. Unfortunately as time passes there is a steadily increasing gap between the classical and parallel programming paradigms and their actual performance on modern computer hardware. In this thesis we consider in depth one particular algorithm, the continuous maximum flow computation. We review in detail why this algorithm is ...

  9. Growth decline assessment in Pinus sylvestris L. and Pinus nigra Arnold. forest by using 3-PG model

    Navarro-Cerrillo, R.M.; Beira, J.; Suarez, J.; Xenakis, G.; Sánchez-Salguero, R.; Hernández-Clemente, R.


    Aim of the study: We assessed the ability of the 3-PG process-based model to accurately predict growth of Pinus sylvestris and P. nigra plantations across a range of sites, showing declining growth trends, in southern Spain. Area of study: The study area is located in “Sierra de Los Filabres” (Almería). Material and methods: The model was modified in fifteen parameters to predict diameter (DBH, cm), basal area increment (BAI, cm2 yr-1) and leaf area index (LAI, m2 m-2) in healthy trees and trees showing declining growth. We assumed that a set of specific physiological parameters (stem partitioning ratio-pFS20, maximum litterfall rate-γFx, maximum canopy conductance-gCx, specific leaf area for mature aged stands-σ1, age at which specific leaf area = ½ (σ0 + σ1), age at full canopy cover-tc, and canopy boundary layer conductance-gB) included in 3-PG would be suitable for predicting growth decline related to climate conditions. The calibrated model was evaluated using dendrochronological and LAI data obtained from plots. Main results: Observed and simulated DBH showed a high correlation (R2 > 0.99) between modelled and measured values for both species. In contrast, modelled and observed BAI showed lower correlation (R2 < 0.68). Sensitivity analysis on 3-PG outputs showed that the foliage parameters - maximum litterfall rate, maximum canopy conductance, specific leaf area for mature aged stands, age at which specific leaf area, and age at full canopy cover - were important for DBH and BAI predictions under drought stress. Research highlights: Our overall results indicated that the 3-PG model could predict growth response of pine plantations to climatic stress with desirable accuracy in southern Spain by using readily available soil and climatic data with physiological parameters derived from experiments. (Author)

  10. Analysis of the maximum discharge of karst springs

    Bonacci, Ognjen


    Analyses are presented of the conditions that limit the discharge of some karst springs. The large number of springs studied show that, under conditions of extremely intense precipitation, a maximum value exists for the discharge of the main springs in a catchment, independent of catchment size and the amount of precipitation. Outflow modelling of karst-spring discharge is not easily generalized and schematized due to numerous specific characteristics of karst-flow systems. A detailed examination of the published data on four karst springs identified the possible reasons for the limitation on the maximum flow rate: (1) limited size of the karst conduit; (2) pressure flow; (3) intercatchment overflow; (4) overflow from the main spring-flow system to intermittent springs within the same catchment; (5) water storage in the zone above the karst aquifer or epikarstic zone of the catchment; and (6) factors such as climate, soil and vegetation cover, and altitude and geology of the catchment area. The phenomenon of limited maximum-discharge capacity of karst springs is not included in rainfall-runoff process modelling, which is probably one of the main reasons for the present poor quality of karst hydrological modelling. Résumé. Les conditions qui limitent le débit de certaines sources karstiques sont présentées. Un grand nombre de sources étudiées montrent que, sous certaines conditions de précipitations extrêmement intenses, il existe une valeur maximale pour le débit des sources principales d'un bassin, indépendante des dimensions de ce bassin et de la hauteur de précipitation. La modélisation des débits d'exhaure d'une source karstique n'est pas facilement généralisable, ni schématisable, à cause des nombreuses caractéristiques spécifiques des écoulements souterrains karstiques. Un examen détaillé des données publiées concernant quatre sources karstiques permet d'identifier les raisons possibles de la limitation de l'écoulement maximal: (1

  11. Improved parameterized complexity of the maximum agreement subtree and maximum compatible tree problems.

    Berry, Vincent; Nicolas, François


    Given a set of evolutionary trees on a same set of taxa, the maximum agreement subtree problem (MAST), respectively, maximum compatible tree problem (MCT), consists of finding a largest subset of taxa such that all input trees restricted to these taxa are isomorphic, respectively compatible. These problems have several applications in phylogenetics such as the computation of a consensus of phylogenies obtained from different data sets, the identification of species subjected to horizontal gene transfers and, more recently, the inference of supertrees, e.g., Trees Of Life. We provide two linear time algorithms to check the isomorphism, respectively, compatibility, of a set of trees or otherwise identify a conflict between the trees with respect to the relative location of a small subset of taxa. Then, we use these algorithms as subroutines to solve MAST and MCT on rooted or unrooted trees of unbounded degree. More precisely, we give exact fixed-parameter tractable algorithms, whose running time is uniformly polynomial when the number of taxa on which the trees disagree is bounded. The improves on a known result for MAST and proves fixed-parameter tractability for MCT.

  12. Has contemporary climate change played a role in population declines of the lizard Ctenophorus decresii from semi-arid Australia?

    Walker, Samantha; Stuart-Fox, Devi; Kearney, Michael R


    Whilst contemporary climatic changes are small in magnitude compared to those predicted for the coming decades, they have already been linked to species range shifts and local extinctions. Elucidating the drivers behind species' responses to contemporary climate change will better inform management strategies for vulnerable and pest species alike. A recent proposal to explain worldwide local extinctions in lizards is that increasing maximum temperatures have constrained lizard activity time in the breeding season beyond extinction thresholds. Here we document a significant population decline and potential local extinction at the warm (northern) range margin of the tawny dragon, Ctenophorus decresii, a rock-dwelling lizard from the Flinders Ranges in semi-arid Australia. We developed and tested a biophysical model of tawny dragon thermoregulatory behaviour and drove the model with daily weather data for the period 1990-2009 across the Flinders Ranges. Our results indicate that potential annual activity time has likely increased over this period throughout the historic range, with within-season declines only in the summer months at the northern range limit. However, populations that have declined since 2000 have also likely experienced higher active body temperatures and more stringent retreat-site requirements (deeper crevices) than have regions where the species remains common, during a period of declining rainfall. Our laboratory estimates of thermal preference in this species were insensitive to altered nutritional and hydric state. Thus it is possible that recent population declines are linked to desiccation stress driven by higher body temperatures and declining rainfall. Our study illustrates that simple indices of the impact of climate warming on animals, such as activity restriction, may in fact reflect a variety of potential mechanisms whose ultimate outcome will be contingent on other factors such as water and shelter availability.

  13. On the decline of biodiversity due to area loss.

    Keil, Petr; Storch, David; Jetz, Walter


    Predictions of how different facets of biodiversity decline with habitat loss are broadly needed, yet challenging. Here we provide theory and a global empirical evaluation to address this challenge. We show that extinction estimates based on endemics-area and backward species-area relationships are complementary, and the crucial difference comprises the geometry of area loss. Across three taxa on four continents, the relative loss of species, and of phylogenetic and functional diversity, is highest when habitable area disappears inward from the edge of a region, lower when it disappears from the centre outwards, and lowest when area is lost at random. In inward destruction, species loss is almost proportional to area loss, although the decline in phylogenetic and functional diversity is less severe. These trends are explained by the geometry of species ranges and the shape of phylogenetic and functional trees, which may allow baseline predictions of biodiversity decline for underexplored taxa.

  14. Invasive alien predator causes rapid declines of native European ladybirds

    Roy, Helen E.; Adriaens, Tim; Isaac, Nick J.B.


    Aim Invasive alien species (IAS) are recognized as major drivers of biodiversity loss, but few causal relationships between IAS and species declines have been documented. In this study, we compare the distribution (Belgium and Britain) and abundance (Belgium, Britain and Switzerland) of formerly...... common and widespread native ladybirds before and after the arrival of Harmonia axyridis, a globally rapidly expanding IAS. Location Europe Methods We used generalized linear mixed-effects models (GLMMs) to assess the distribution trends of eight conspicuous and historically widespread and common species...... surveys of deciduous trees in Belgium, Britain and Switzerland. Results Five (Belgium) and seven (Britain) of eight species studied show substantial declines attributable to the arrival of H. axyridis. Indeed, the two-spot ladybird, Adalia bipunctata, declined by 30% (Belgium) and 44% (Britain) over 5...

  15. Declining numbers of pancreas transplantations but significant improvements in outcome.

    Gruessner, A C; Gruessner, R W G


    In the United States, over the past 8 years, the number of pancreas transplantations has steadily declined. This decline comes as a surprise, because patient and graft outcomes have substantially improved during the same period of time. Patient survival rates at 1 year in all 3 recipient categories are >96%; graft survival rates are 82%-89%. Changes in immunosuppressive therapy have had a positive impact on outcome, as have better pancreas donor and recipient selection criteria and refined post-transplantation patient care. Although different factors may have contributed to the declining pancreas transplantation numbers, a more effective process of publicly promoting and widely communicating the improved results of pancreas transplantation is warranted.

  16. Analysis of FEV1 decline in relatively healthy heavy smokers

    Thomsen, Laura H.; Dirksen, Asger; Shaker, Saher B.;


    Progressive decline in lung function has been widely accepted as the hallmark of chronic obstructive pulmonary disease (COPD); however, recent evidence indicates that the rate of decline measured as decline in forced expiratory volume in one second (FEV1) is higher in mild to moderate COPD than...... in severe COPD. Usually changes in FEV1 are measured in ml that is "absolute"; however, changes can also be measured "relative" as a percentage of the actual FEV1. We hypothesize that relative measurements could be more appropriate than absolute measurements for describing changes in lung function. We...... analyzed data from 3,218 relatively healthy heavy smokers who participated in the Danish Lung Cancer Screening Trial. The influences of age, sex, height, body mass index, smoking, and severity of airflow limitation on FEV1 were analyzed in mixed effects models. In absolute terms those with the best lung...

  17. Dynamics of Motorized Vehicle Flow under Mixed Traffic Circumstance*

    GUO nong-Wei; GAO Zi-You; ZHAO Xiao-Mei; XIE Dong-Fan


    To study the dynamics of mixed traffic flow consisting of motorized and non-motorized vehicles, a carfollowing model based on the principle of collision free and cautious driving is proposed.Lateral friction and overlapping driving are introduced to describe the interactions between motorized vehicles and non-motorized vehicles.By numerical simulations, the flux-density relation, the temporal-spatial dynamics, and the velocity evolution are investigated in detail.The results indicate non-motorized vehicles have a significant impact on the motorized vehicle flow and cause the maximum flux to decline by about 13%.Non-motorized vehicles can decrease the motorized vehicle velocity and cause velocity oscillation when the motorized vehicle density is low.Moreover, non-motorized vehicles show a significant damping effect on the oscillating velocity when the density is medium and high, and such an effect weakens as motorized vehicle densityincreases.The results also stress the necessity for separating motorized vehicles from non-motorized vehicles.

  18. Numerical Simulation of Natural Gas Flow in Anisotropic Shale Reservoirs

    Negara, Ardiansyah


    Shale gas resources have received great attention in the last decade due to the decline of the conventional gas resources. Unlike conventional gas reservoirs, the gas flow in shale formations involves complex processes with many mechanisms such as Knudsen diffusion, slip flow (Klinkenberg effect), gas adsorption and desorption, strong rock-fluid interaction, etc. Shale formations are characterized by the tiny porosity and extremely low-permeability such that the Darcy equation may no longer be valid. Therefore, the Darcy equation needs to be revised through the permeability factor by introducing the apparent permeability. With respect to the rock formations, several studies have shown the existence of anisotropy in shale reservoirs, which is an essential feature that has been established as a consequence of the different geological processes over long period of time. Anisotropy of hydraulic properties of subsurface rock formations plays a significant role in dictating the direction of fluid flow. The direction of fluid flow is not only dependent on the direction of pressure gradient, but it also depends on the principal directions of anisotropy. Therefore, it is very important to take into consideration anisotropy when modeling gas flow in shale reservoirs. In this work, the gas flow mechanisms as mentioned earlier together with anisotropy are incorporated into the dual-porosity dual-permeability model through the full-tensor apparent permeability. We employ the multipoint flux approximation (MPFA) method to handle the full-tensor apparent permeability. We combine MPFA method with the experimenting pressure field approach, i.e., a newly developed technique that enables us to solve the global problem by breaking it into a multitude of local problems. This approach generates a set of predefined pressure fields in the solution domain in such a way that the undetermined coefficients are calculated from these pressure fields. In other words, the matrix of coefficients

  19. Recent widespread tree growth decline despite increasing atmospheric CO2.

    Lucas C R Silva

    Full Text Available BACKGROUND: The synergetic effects of recent rising atmospheric CO(2 and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. METHODOLOGY/PRINCIPAL FINDINGS: Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE and growth of two deciduous and two coniferous tree species along a 9 degrees latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment--BAI has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. CONCLUSIONS: Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios.

  20. Predicting functional decline and survival in amyotrophic lateral sclerosis.

    Ong, Mei-Lyn; Tan, Pei Fang; Holbrook, Joanna D


    Better predictors of amyotrophic lateral sclerosis disease course could enable smaller and more targeted clinical trials. Partially to address this aim, the Prize for Life foundation collected de-identified records from amyotrophic lateral sclerosis sufferers who participated in clinical trials of investigational drugs and made them available to researchers in the PRO-ACT database. In this study, time series data from PRO-ACT subjects were fitted to exponential models. Binary classes for decline in the total score of amyotrophic lateral sclerosis functional rating scale revised (ALSFRS-R) (fast/slow progression) and survival (high/low death risk) were derived. Data was segregated into training and test sets via cross validation. Learning algorithms were applied to the demographic, clinical and laboratory parameters in the training set to predict ALSFRS-R decline and the derived fast/slow progression and high/low death risk categories. The performance of predictive models was assessed by cross-validation in the test set using Receiver Operator Curves and root mean squared errors. A model created using a boosting algorithm containing the decline in four parameters (weight, alkaline phosphatase, albumin and creatine kinase) post baseline, was able to predict functional decline class (fast or slow) with fair accuracy (AUC = 0.82). However similar approaches to build a predictive model for decline class by baseline subject characteristics were not successful. In contrast, baseline values of total bilirubin, gamma glutamyltransferase, urine specific gravity and ALSFRS-R item score-climbing stairs were sufficient to predict survival class. Using combinations of small numbers of variables it was possible to predict classes of functional decline and survival across the 1-2 year timeframe available in PRO-ACT. These findings may have utility for design of future ALS clinical trials.

  1. Recent widespread tree growth decline despite increasing atmospheric CO2.

    Silva, Lucas C R; Anand, Madhur; Leithead, Mark D


    The synergetic effects of recent rising atmospheric CO(2) and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE) and growth of two deciduous and two coniferous tree species along a 9 degrees latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment--BAI) has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios.

  2. Effects of surface wind speed decline on hydrology in China

    Liu, X.; Zhang, X.; Tang, Q.; Zhang, X.


    Surface wind speed decline in China has been widely reported, but its effects on hydrology have not been fully evaluated to date. In this study, we evaluate the effects of wind speed decline on hydrology in China during 1966-2011 by using the Variable Infiltration Capacity (VIC) hydrological model. Two model experiments, i.e. VIC simulations with the observed (EXP1) and detrended wind speed (EXP2), are performed in the major river basins in China. The differences between the two experiments are analyzed to assess the effects of wind speed decline on hydrology. Results show that wind speed has decreased by 29% of its mean in China, even by 80% for some areas in the northern China. The wind speed decline have resulted in a decrease of evapotranspiration by 1-3% of mean annual evapotranspiration and an increase of runoff by 1-6% of mean annual runoff at most basins in China. The effect of wind speed on runoff and soil moisture is large in the northern basins where small change in hydrological conditions would have significant implications for water management. In addition, Wind speed decline has offset the expansion of the drought area in China. It has contributed to a reduction of drought areas by 21%, 17%, 15% and 12% for the mean drought area in the Songhuajiang River, Hai River, Liao River and Yellow River basins, respectively, and by 8.8% of the mean drought area over China. The effect of wind speed decline on soil moisture drought is large in most basins in China expect for the Southwest and Pearl River basins.

  3. Decline of a Hydrothermal Vent Field - Escanaba Trough 12 Years Later

    Zierenberg, R. A.; Clague, D. A.; Davis, A. S.; Lilley, M. D.; McClain, J. S.; Olson, E. S.; Ross, S. L.; Von Damm, K. L.


    Hydrothermal venting was discovered in Escanaba Trough, the southern sediment-covered portion of the Gorda Ridge, in 1988. Large pyrrhotite-rich massive sulfide mounds are abundant at each of the volcanic/intrusive centers that have been investigated in Escanaba Trough, but the only area of known hydrothermal venting is the NESCA site along the ridge axis at 41\\deg N. Hydrothermal fluids venting at 217\\deg C and 108\\deg C were sampled in 1988 on two sulfide mounds separated by about 275 m. The end-member fluid compositions were indistinguishable within analytical errors. Several sulfide mounds were observed in 1988 which had diffusely venting low temperature (holes were drilled in the NESCA area in 1996 on ODP Leg 169, including Hole 1036I that penetrated to basaltic basement at 405 m below sea floor (mbsf). Surveys of the area using the drill string camera located only one area of active venting at the same mound where 217\\deg C vent fluids were sampled from two active vents in 1988. Drill hole 1036A was spudded between the two active vents on this sulfide mound (approximately 4 and 8 m away) and penetrated to 115 mbsf. The NESCA site was revisited in 2000 using MBARI's R/V Western Flyer and ROV Tiburon. The hydrothermal vents appeared essentially identical to observations made from the drill string camera in 1996 despite the presence of a drill hole within meters of the two vents. The maximum vent temperature measured in 2000 was 212\\deg C. Fluid samples have major element and isotopic compositions very similar to those collected in 1988. The vent fluids have higher methane ( ~19 mmol/kg) than those from the geologically similar Middle Valley vent field, but lower values than those at Guaymas Basin. Drill hole 1036A was weakly venting, but the diffuse hydrothermal fluids could not be sampled with the equipment available. The walls of the drill hole were colonized by palm worms, limpets, and snails. Four other drill holes showed no hydrothermal flow nor

  4. Effects of loading and size on maximum power output and gait characteristics in geckos.

    Irschick, Duncan J; Vanhooydonck, Bieke; Herrel, Anthony; Andronescu, Anemone


    Stride length, stride frequency and power output are all factors influencing locomotor performance. Here, we first test whether mass-specific power output limits climbing performance in two species of geckos (Hemidactylus garnoti and Gekko gecko) by adding external loads to their bodies. We then test whether body size has a negative effect on mass-specific power output. Finally, we test whether loading affects kinematics in both gecko species. Lizards were induced to run vertically on a smooth wooden surface with loads of 0-200% of body mass (BM) in H. garnoti and 0-100% BM in G. gecko. For each stride, we calculated angular and linear kinematics (e.g. trunk angle, stride length), performance (maximum speed) and mean mass-specific power output per stride. The addition of increasingly large loads caused an initial increase in maximum mass-specific power output in both species, but for H. garnoti, mass-specific power output remained constant at higher loads (150% and 200% BM), even though maximum velocity declined. This result, in combination with the fact that stride frequency showed no evidence of leveling off as speed increased in either species, suggests that power limits maximum speed. In addition, the large gecko (G. gecko) produced significantly less power than the smaller H. garnoti, despite the fact that both species ran at similar speeds. This difference disappeared, however, when we recalculated power output based on higher maximum speeds for unloaded G. gecko moving vertically obtained by other researchers. Finally, the addition of external loads did not affect speed modulation in either species: both G. gecko and H. garnoti increase speed primarily by increasing stride frequency, regardless of loading condition. For a given speed, both species take shorter but more strides with heavier loads, but for a given load, G. gecko attains similar speeds to H. garnoti by taking longer but fewer strides.

  5. The future of species under climate change: resilience or decline?

    Moritz, Craig; Agudo, Rosa


    As climates change across already stressed ecosystems, there is no doubt that species will be affected, but to what extent and which will be most vulnerable remain uncertain. The fossil record suggests that most species persisted through past climate change, whereas forecasts of future impacts predict large-scale range reduction and extinction. Many species have altered range limits and phenotypes through 20th-century climate change, but responses are highly variable. The proximate causes of species decline relative to resilience remain largely obscure; however, recent examples of climate-associated species decline can help guide current management in parallel with ongoing research.

  6. Amphibian decline: An integrated analysis of multiple stressor effects

    Linder, G.; Krest, S.K.; Sparling, D. W.; Linder, G.; Krest, S.K.; Sparling, D.W.


    Capturing the attention and imagination of the public and the scientific community alike, the mysterious decline in amphibian populations drew scientists and resource managers from ecotoxicology and chemistry, ecology and field biology, conservation biology, and natural resource policy to a SETAC–Johnson Foundation workshop. Facilitating environmental stewardship, increasing capacity of the sciences to explain complex stressors, and educating the public on relationships among communities of all types motivated these experts to address amphibian decline and the role of various stressors in these losses.


    Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Arons, Jonathan, E-mail: [Department of Astronomy, Department of Physics, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)


    The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 {approx}< {sigma} {approx}< 10{sup -1}. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is {sigma} {approx}< 10{sup -3}. For electron-ion plasmas, the transition to efficient acceleration occurs for {sigma} {approx}< 3 Multiplication-Sign 10{sup -5}. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as {epsilon}{sub max}{proportional_to}t {sup 1/2}. This scaling is shallower than the so-called (and commonly assumed) Bohm limit {epsilon}{sub max}{proportional_to}t, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value {epsilon}{sub sat}/{gamma}{sub 0} m{sub i}c {sup 2} {approx} {sigma}{sup -1/4}, where {gamma}{sub 0} m{sub i}c {sup 2} is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness {proportional_to}{sigma}{sup -1/2} around the shock. Our results can provide physically

  8. Non-invasive body temperature measurement of wild chimpanzees using fecal temperature decline.

    Jensen, Siv Aina; Mundry, Roger; Nunn, Charles L; Boesch, Christophe; Leendertz, Fabian H


    New methods are required to increase our understanding of pathologic processes in wild mammals. We developed a noninvasive field method to estimate the body temperature of wild living chimpanzees habituated to humans, based on statistically fitting temperature decline of feces after defecation. The method was established with the use of control measures of human rectal temperature and subsequent changes in fecal temperature over time. The method was then applied to temperature data collected from wild chimpanzee feces. In humans, we found good correspondence between the temperature estimated by the method and the actual rectal temperature that was measured (maximum deviation 0.22 C). The method was successfully applied and the average estimated temperature of the chimpanzees was 37.2 C. This simple-to-use field method reliably estimates the body temperature of wild chimpanzees and probably also other large mammals.

  9. Peat bogs in northern Alberta, Canada reveal decades of declining atmospheric Pb contamination

    Shotyk, William; Appleby, Peter G.; Bicalho, Beatriz; Davies, Lauren; Froese, Duane; Grant-Weaver, Iain; Krachler, Michael; Magnan, Gabriel; Mullan-Boudreau, Gillian; Noernberg, Tommy; Pelletier, Rick; Shannon, Bob; Bellen, Simon; Zaccone, Claudio


    Peat cores were collected from six bogs in northern Alberta to reconstruct changes in the atmospheric deposition of Pb, a valuable tracer of human activities. In each profile, the maximum Pb enrichment is found well below the surface. Radiometric age dating using three independent approaches (14C measurements of plant macrofossils combined with the atmospheric bomb pulse curve, plus 210Pb confirmed using the fallout radionuclides 137Cs and 241Am) showed that Pb contamination has been in decline for decades. Today, the surface layers of these bogs are comparable in composition to the "cleanest" peat samples ever found in the Northern Hemisphere, from a Swiss bog ~ 6000 to 9000 years old. The lack of contemporary Pb contamination in the Alberta bogs is testimony to successful international efforts of the past decades to reduce anthropogenic emissions of this potentially toxic metal to the atmosphere.

  10. Possible environmental factors underlying amphibian decline in eastern Puerto Rico: Analysis of U.S. government data archives

    Stallard, R.F.


    The past three decades have seen major declines in populations of several species of amphibians at high elevations in eastern Puerto Rico, a region unique in the humid tropics because of the degree of environmental monitoring that has taken place through the efforts of U.S. government agencies. I examined changes in environmental conditions by examining time-series data sets that extend back at least into the 1980s, a period when frog populations were declining. The data include forest cover; annual mean, minimum, and maximum daily temperature; annual rainfall; rain and stream chemistry; and atmospheric-dust transport. I examined satellite imagery and air-chemistry samples from a single National Aeronautics and Space Administration aircraft flight across the Caribbean showing patches of pollutants, described as thin sheets or lenses, in the lower troposphere. The main source of these pollutants appeared to be fires from land clearing and deforestation, primarily in Africa. Some pollutant concentrations were high and, in the case of ozone, approached health limits set for urban air. Urban pollution impinging on Puerto Rico, dust generation from Africa (potential soil pathogens), and tropical forest burning (gaseous pollutants) have all increased during the last three decades, overlapping the timing of amphibian declines in eastern Puerto Rico. None of the data sets pointed directly to changes so extreme that they might be considered a direct lethal cause of amphibian declines in Puerto Rico. More experimental research is required to link any of these environmental factors to this problem.

  11. The Dynamics of Son Preference, Technology Diffusion, and Fertility Decline Underlying Distorted Sex Ratios at Birth: A Simulation Approach.

    Kashyap, Ridhi; Villavicencio, Francisco


    We present a micro-founded simulation model that formalizes the "ready, willing, and able" framework, originally used to explain historical fertility decline, to the practice of prenatal sex selection. The model generates sex ratio at birth (SRB) distortions from the bottom up and attempts to quantify plausible levels, trends, and interactions of son preference, technology diffusion, and fertility decline that underpin SRB trajectories at the macro level. Calibrating our model for South Korea, we show how even as the proportion with a preference for sons was declining, SRB distortions emerged due to rapid diffusion of prenatal sex determination technology combined with small but growing propensities to abort at low birth parities. Simulations reveal that relatively low levels of son preference (about 20 % to 30 % wanting one son) can result in skewed SRB levels if technology diffuses early and steadily, and if fertility falls rapidly to encourage sex-selective abortion at low parities. Model sensitivity analysis highlights how the shape of sex ratio trajectories is particularly sensitive to the timing and speed of prenatal sex-determination technology diffusion. The maximum SRB levels reached in a population are influenced by how the readiness to abort rises as a function of the fertility decline.

  12. Present and Last Glacial Maximum climates as states of maximum entropy production

    Herbert, Corentin; Kageyama, Masa; Dubrulle, Berengere


    The Earth, like other planets with a relatively thick atmosphere, is not locally in radiative equilibrium and the transport of energy by the geophysical fluids (atmosphere and ocean) plays a fundamental role in determining its climate. Using simple energy-balance models, it was suggested a few decades ago that the meridional energy fluxes might follow a thermodynamic Maximum Entropy Production (MEP) principle. In the present study, we assess the MEP hypothesis in the framework of a minimal climate model based solely on a robust radiative scheme and the MEP principle, with no extra assumptions. Specifically, we show that by choosing an adequate radiative exchange formulation, the Net Exchange Formulation, a rigorous derivation of all the physical parameters can be performed. The MEP principle is also extended to surface energy fluxes, in addition to meridional energy fluxes. The climate model presented here is extremely fast, needs very little empirical data and does not rely on ad hoc parameterizations. We in...

  13. Cerebrovascular resistance: effects on cognitive decline, cortical atrophy, and progression to dementia.

    Yew, Belinda; Nation, Daniel A


    See Markus (doi:10.1093/awx161) for a scientific commentary on this article.Evidence for vascular contributions to Alzheimer's disease has been increasingly identified, with increased blood pressure and decreased cerebral blood flow both linked to in vivo biomarkers and clinical progression of Alzheimer's disease. We therefore hypothesized that an elevated ratio of blood pressure to cerebral blood flow, indicative of cerebrovascular resistance, would exhibit earlier and more widespread associations with Alzheimer's disease than cerebral blood flow alone. Further, we predicted that increased cerebrovascular resistance and amyloid retention would synergistically influence cognitive performance trajectories, independent of neuronal metabolism. Lastly, we anticipated associations between cerebrovascular resistance and later brain atrophy, prior to amyloid accumulation. To evaluate these hypotheses, we investigated associations between cerebrovascular resistance and amyloid retention, cognitive decline, and brain atrophy, controlling for neuronal metabolism. North American older adults (n = 232) underwent arterial spin labelling magnetic resonance imaging to measure regional cerebral blood flow in brain regions susceptible to ageing and Alzheimer's disease. An estimated cerebrovascular resistance index was then calculated as the ratio of mean arterial pressure to regional cerebral blood flow. Positron emission tomography with 18F-florbetapir and fludeoxyglucose was used to quantify amyloid retention and neuronal metabolism, respectively. Cognitive performance was evaluated via annual assessments of global cognition, memory, and executive function. Results indicated diminished inferior parietal and temporal cerebral blood flow for patients with Alzheimer's disease (n = 33) relative to both non-demented groups, but no cerebral blood flow differences between non-demented amyloid-positive (n = 87) and amyloid-negative (n = 112) cases. In contrast, the cerebrovascular

  14. The mechanics of granitoid systems and maximum entropy production rates.

    Hobbs, Bruce E; Ord, Alison


    A model for the formation of granitoid systems is developed involving melt production spatially below a rising isotherm that defines melt initiation. Production of the melt volumes necessary to form granitoid complexes within 10(4)-10(7) years demands control of the isotherm velocity by melt advection. This velocity is one control on the melt flux generated spatially just above the melt isotherm, which is the control valve for the behaviour of the complete granitoid system. Melt transport occurs in conduits initiated as sheets or tubes comprising melt inclusions arising from Gurson-Tvergaard constitutive behaviour. Such conduits appear as leucosomes parallel to lineations and foliations, and ductile and brittle dykes. The melt flux generated at the melt isotherm controls the position of the melt solidus isotherm and hence the physical height of the Transport/Emplacement Zone. A conduit width-selection process, driven by changes in melt viscosity and constitutive behaviour, operates within the Transport Zone to progressively increase the width of apertures upwards. Melt can also be driven horizontally by gradients in topography; these horizontal fluxes can be similar in magnitude to vertical fluxes. Fluxes induced by deformation can compete with both buoyancy and topographic-driven flow over all length scales and results locally in transient 'ponds' of melt. Pluton emplacement is controlled by the transition in constitutive behaviour of the melt/magma from elastic-viscous at high temperatures to elastic-plastic-viscous approaching the melt solidus enabling finite thickness plutons to develop. The system involves coupled feedback processes that grow at the expense of heat supplied to the system and compete with melt advection. The result is that limits are placed on the size and time scale of the system. Optimal characteristics of the system coincide with a state of maximum entropy production rate.

  15. Early-Onset, Regular Cannabis Use Is Linked to IQ Decline

    ... Is Linked to IQ Decline Early-Onset, Regular Cannabis Use Is Linked to IQ Decline Email Facebook ... that cannabis use may harm the developing brain. Cannabis Use Correlates With Cognitive Decline The study participants ...


    Foley, Ryan J.; Marion, G. Howie; Challis, Peter; Kirshner, Robert P.; Berta, Zachory K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kromer, Markus; Taubenberger, Stefan; Hillebrandt, Wolfgang; Roepke, Friedrich K.; Ciaraldi-Schoolmann, Franco; Seitenzahl, Ivo R. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, D-85748 Garching bei Muenchen (Germany); Pignata, Giuliano [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Stritzinger, Maximilian D. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C (Denmark); Filippenko, Alexei V.; Li Weidong; Silverman, Jeffrey M. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Folatelli, Gaston [Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583 (Japan); Hsiao, Eric Y.; Morrell, Nidia I. [Carnegie Observatories, Las Campanas Observatory, La Serena (Chile); Simcoe, Robert A., E-mail: [MIT-Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37-664D Cambridge, MA 02139 (United States); and others


    We present the first maximum-light ultraviolet (UV) through near-infrared (NIR) Type Ia supernova (SN Ia) spectrum. This spectrum of SN 2011iv was obtained nearly simultaneously by the Hubble Space Telescope at UV/optical wavelengths and the Magellan Baade telescope at NIR wavelengths. These data provide the opportunity to examine the entire maximum-light SN Ia spectral energy distribution. Since the UV region of an SN Ia spectrum is extremely sensitive to the composition of the outer layers of the explosion, which are transparent at longer wavelengths, this unprecedented spectrum can provide strong constraints on the composition of the SN ejecta, and similarly the SN explosion and progenitor system. SN 2011iv is spectroscopically normal, but has a relatively fast decline ({Delta}m{sub 15}(B) = 1.69 {+-} 0.05 mag). We compare SN 2011iv to other SNe Ia with UV spectra near maximum light and examine trends between UV spectral properties, light-curve shape, and ejecta velocity. We tentatively find that SNe with similar light-curve shapes but different ejecta velocities have similar UV spectra, while those with similar ejecta velocities but different light-curve shapes have very different UV spectra. Through a comparison with explosion models, we find that both a solar-metallicity W7 and a zero-metallicity delayed-detonation model provide a reasonable fit to the spectrum of SN 2011iv from the UV to the NIR.

  17. Strong Solar Control of Infrared Aurora on Jupiter: Correlation Since the Last Solar Maximum

    Kostiuk, T.; Livengood, T. A.; Hewagama, T.


    Polar aurorae in Jupiter's atmosphere radiate throughout the electromagnetic spectrum from X ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based spectroscopic measurements of Jupiter's northern mid-IR aurora, acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane emission brightness and solar 10.7 cm radio flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high solar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the Europa Jupiter System Mission. Results of observations at the Infrared Telescope Facility (IRTF) operated by the University of Hawaii under Cooperative Agreement no. NCC5-538 with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program. This work was supported by the NASA Planetary Astronomy Program.

  18. Evaluation of the Charm maximum residue limit β-lactam and tetracycline test for the detection of antibiotics in ewe and goat milk

    Beltrán, M C; Romero, T; Althaus, R L; Molina, M P


    The Charm maximum residue limit β-lactam and tetracycline test (Charm MRL BLTET; Charm Sciences Inc., Lawrence, MA) is an immunoreceptor assay utilizing Rapid One-Step Assay lateral flow technology that detects...

  19. Thermal physiology, disease, and amphibian declines on the eastern slopes of the Andes.

    Catenazzi, Alessandro; Lehr, Edgar; Vredenburg, Vance T


    Rising temperatures, a widespread consequence of climate change, have been implicated in enigmatic amphibian declines from habitats with little apparent human impact. The pathogenic fungus Batrachochytrium dendrobatidis (Bd), now widespread in Neotropical mountains, may act in synergy with climate change causing collapse in thermally stressed hosts. We measured the thermal tolerance of frogs along a wide elevational gradient in the Tropical Andes, where frog populations have collapsed. We used the difference between critical thermal maximum and the temperature a frog experiences in nature as a measure of tolerance to high temperatures. Temperature tolerance increased as elevation increased, suggesting that frogs at higher elevations may be less sensitive to rising temperatures. We tested the alternative pathogen optimal growth hypothesis that prevalence of the pathogen should decrease as temperatures fall outside the optimal range of pathogen growth. Our infection-prevalence data supported the pathogen optimal growth hypothesis because we found that prevalence of Bd increased when host temperatures matched its optimal growth range. These findings suggest that rising temperatures may not be the driver of amphibian declines in the eastern slopes of the Andes. Zoonotic outbreaks of Bd are the most parsimonious hypothesis to explain the collapse of montane amphibian faunas; but our results also reveal that lowland tropical amphibians, despite being shielded from Bd by higher temperatures, are vulnerable to climate-warming stress.

  20. Millennial-scale ocean acidification and late Quaternary decline of cryptic bacterial crusts in tropical reefs.

    Riding, R; Liang, L; Braga, J C


    Ocean acidification by atmospheric carbon dioxide has increased almost continuously since the last glacial maximum (LGM), 21,000 years ago. It is expected to impair tropical reef development, but effects on reefs at the present day and in the recent past have proved difficult to evaluate. We present evidence that acidification has already significantly reduced the formation of calcified bacterial crusts in tropical reefs. Unlike major reef builders such as coralline algae and corals that more closely control their calcification, bacterial calcification is very sensitive to ambient changes in carbonate chemistry. Bacterial crusts in reef cavities have declined in thickness over the past 14,000 years with largest reduction occurring 12,000-10,000 years ago. We interpret this as an early effect of deglacial ocean acidification on reef calcification and infer that similar crusts were likely to have been thicker when seawater carbonate saturation was increased during earlier glacial intervals, and thinner during interglacials. These changes in crust thickness could have substantially affected reef development over glacial cycles, as rigid crusts significantly strengthen framework and their reduction would have increased the susceptibility of reefs to biological and physical erosion. Bacterial crust decline reveals previously unrecognized millennial-scale acidification effects on tropical reefs. This directs attention to the role of crusts in reef formation and the ability of bioinduced calcification to reflect changes in seawater chemistry. It also provides a long-term context for assessing anticipated anthropogenic effects. © 2014 John Wiley & Sons Ltd.