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Sample records for anti-correlated signals quantified

Effects of coarse-graining on the scaling behavior of long-range correlated and anti-correlated signals

OpenAIRE

Xu, Yinlin; Ma, Qianli D.Y.; Schmitt, Daniel T.; Bernaola-Galván, Pedro; Ivanov, Plamen Ch.

2011-01-01

We investigate how various coarse-graining methods affect the scaling properties of long-range power-law correlated and anti-correlated signals, quantified by the detrended fluctuation analysis. Specifically, for coarse-graining in the magnitude of a signal, we consider (i) the Floor, (ii) the Symmetry and (iii) the Centro-Symmetry coarse-graining methods. We find, that for anti-correlated signals coarse-graining in the magnitude leads to a crossover to random behavior at large scales, and th...
Effects of coarse-graining on the scaling behavior of long-range correlated and anti-correlated signals.

Science.gov (United States)

Xu, Yinlin; Ma, Qianli D Y; Schmitt, Daniel T; Bernaola-Galván, Pedro; Ivanov, Plamen Ch

2011-11-01

We investigate how various coarse-graining (signal quantization) methods affect the scaling properties of long-range power-law correlated and anti-correlated signals, quantified by the detrended fluctuation analysis. Specifically, for coarse-graining in the magnitude of a signal, we consider (i) the Floor, (ii) the Symmetry and (iii) the Centro-Symmetry coarse-graining methods. We find that for anti-correlated signals coarse-graining in the magnitude leads to a crossover to random behavior at large scales, and that with increasing the width of the coarse-graining partition interval Δ, this crossover moves to intermediate and small scales. In contrast, the scaling of positively correlated signals is less affected by the coarse-graining, with no observable changes when Δ 1 a crossover appears at small scales and moves to intermediate and large scales with increasing Δ. For very rough coarse-graining (Δ > 3) based on the Floor and Symmetry methods, the position of the crossover stabilizes, in contrast to the Centro-Symmetry method where the crossover continuously moves across scales and leads to a random behavior at all scales; thus indicating a much stronger effect of the Centro-Symmetry compared to the Floor and the Symmetry method. For coarse-graining in time, where data points are averaged in non-overlapping time windows, we find that the scaling for both anti-correlated and positively correlated signals is practically preserved. The results of our simulations are useful for the correct interpretation of the correlation and scaling properties of symbolic sequences.
Early anti-correlated BOLD signal changes of physiologic origin.

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Bright, Molly G; Bianciardi, Marta; de Zwart, Jacco A; Murphy, Kevin; Duyn, Jeff H

2014-02-15

Negative BOLD signals that are synchronous with resting state fluctuations have been observed in large vessels in the cortical sulci and surrounding the ventricles. In this study, we investigated the origin of these negative BOLD signals by applying a Cued Deep Breathing (CDB) task to create transient hypocapnia and a resultant global fMRI signal decrease. We hypothesized that a global stimulus would amplify the effect in large vessels and that using a global negative (vasoconstrictive) stimulus would test whether these voxels exhibit either inherently negative or simply anti-correlated BOLD responses. Significantly anti-correlated, but positive, BOLD signal changes during respiratory challenges were identified in voxels primarily located near edges of brain spaces containing CSF. These positive BOLD responses occurred earlier than the negative CDB response across most of gray matter voxels. These findings confirm earlier suggestions that in some brain regions, local, fractional changes in CSF volume may overwhelm BOLD-related signal changes, leading to signal anti-correlation. We show that regions with CDB anti-correlated signals coincide with most, but not all, of the regions with negative BOLD signal changes observed during a visual and motor stimulus task. Thus, the addition of a physiological challenge to fMRI experiments can help identify which negative BOLD signals are passive physiological anti-correlations and which may have a putative neuronal origin. Published by Elsevier Inc.
The impact of global signal regression on resting state correlations: are anti-correlated networks introduced?

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Murphy, Kevin; Birn, Rasmus M; Handwerker, Daniel A; Jones, Tyler B; Bandettini, Peter A

2009-02-01

Low-frequency fluctuations in fMRI signal have been used to map several consistent resting state networks in the brain. Using the posterior cingulate cortex as a seed region, functional connectivity analyses have found not only positive correlations in the default mode network but negative correlations in another resting state network related to attentional processes. The interpretation is that the human brain is intrinsically organized into dynamic, anti-correlated functional networks. Global variations of the BOLD signal are often considered nuisance effects and are commonly removed using a general linear model (GLM) technique. This global signal regression method has been shown to introduce negative activation measures in standard fMRI analyses. The topic of this paper is whether such a correction technique could be the cause of anti-correlated resting state networks in functional connectivity analyses. Here we show that, after global signal regression, correlation values to a seed voxel must sum to a negative value. Simulations also show that small phase differences between regions can lead to spurious negative correlation values. A combination breath holding and visual task demonstrates that the relative phase of global and local signals can affect connectivity measures and that, experimentally, global signal regression leads to bell-shaped correlation value distributions, centred on zero. Finally, analyses of negatively correlated networks in resting state data show that global signal regression is most likely the cause of anti-correlations. These results call into question the interpretation of negatively correlated regions in the brain when using global signal regression as an initial processing step.
Anti-correlated networks, global signal regression, and the effects of caffeine in resting-state functional MRI.

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Wong, Chi Wah; Olafsson, Valur; Tal, Omer; Liu, Thomas T

2012-10-15

Resting-state functional connectivity magnetic resonance imaging is proving to be an essential tool for the characterization of functional networks in the brain. Two of the major networks that have been identified are the default mode network (DMN) and the task positive network (TPN). Although prior work indicates that these two networks are anti-correlated, the findings are controversial because the anti-correlations are often found only after the application of a pre-processing step, known as global signal regression, that can produce artifactual anti-correlations. In this paper, we show that, for subjects studied in an eyes-closed rest state, caffeine can significantly enhance the detection of anti-correlations between the DMN and TPN without the need for global signal regression. In line with these findings, we find that caffeine also leads to widespread decreases in connectivity and global signal amplitude. Using a recently introduced geometric model of global signal effects, we demonstrate that these decreases are consistent with the removal of an additive global signal confound. In contrast to the effects observed in the eyes-closed rest state, caffeine did not lead to significant changes in global functional connectivity in the eyes-open rest state. Copyright © 2012 Elsevier Inc. All rights reserved.
Anti-correlated cortical networks of intrinsic connectivity in the rat brain.

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Schwarz, Adam J; Gass, Natalia; Sartorius, Alexander; Risterucci, Celine; Spedding, Michael; Schenker, Esther; Meyer-Lindenberg, Andreas; Weber-Fahr, Wolfgang

2013-01-01

In humans, resting-state blood oxygen level-dependent (BOLD) signals in the default mode network (DMN) are temporally anti-correlated with those from a lateral cortical network involving the frontal eye fields, secondary somatosensory and posterior insular cortices. Here, we demonstrate the existence of an analogous lateral cortical network in the rat brain, extending laterally from anterior secondary sensorimotor regions to the insular cortex and exhibiting low-frequency BOLD fluctuations that are temporally anti-correlated with a midline "DMN-like" network comprising posterior/anterior cingulate and prefrontal cortices. The primary nexus for this anti-correlation relationship was the anterior secondary motor cortex, close to regions that have been identified with frontal eye fields in the rat brain. The anti-correlation relationship was corroborated after global signal removal, underscoring this finding as a robust property of the functional connectivity signature in the rat brain. These anti-correlated networks demonstrate strong anatomical homology to networks identified in human and monkey connectivity studies, extend the known preserved functional connectivity relationships between rodent and primates, and support the use of resting-state functional magnetic resonance imaging as a translational imaging method between rat models and humans.
Continuous detection of weak sensory signals in afferent spike trains: the role of anti-correlated interspike intervals in detection performance.

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Goense, J B M; Ratnam, R

2003-10-01

An important problem in sensory processing is deciding whether fluctuating neural activity encodes a stimulus or is due to variability in baseline activity. Neurons that subserve detection must examine incoming spike trains continuously, and quickly and reliably differentiate signals from baseline activity. Here we demonstrate that a neural integrator can perform continuous signal detection, with performance exceeding that of trial-based procedures, where spike counts in signal- and baseline windows are compared. The procedure was applied to data from electrosensory afferents of weakly electric fish (Apteronotus leptorhynchus), where weak perturbations generated by small prey add approximately 1 spike to a baseline of approximately 300 spikes s(-1). The hypothetical postsynaptic neuron, modeling an electrosensory lateral line lobe cell, could detect an added spike within 10-15 ms, achieving near ideal detection performance (80-95%) at false alarm rates of 1-2 Hz, while trial-based testing resulted in only 30-35% correct detections at that false alarm rate. The performance improvement was due to anti-correlations in the afferent spike train, which reduced both the amplitude and duration of fluctuations in postsynaptic membrane activity, and so decreased the number of false alarms. Anti-correlations can be exploited to improve detection performance only if there is memory of prior decisions.
Signal correlations in biomass combustion. An information theoretic analysis

Energy Technology Data Exchange (ETDEWEB)

Ruusunen, M.

2013-09-01

Increasing environmental and economic awareness are driving the development of combustion technologies to efficient biomass use and clean burning. To accomplish these goals, quantitative information about combustion variables is needed. However, for small-scale combustion units the existing monitoring methods are often expensive or complex. This study aimed to quantify correlations between flue gas temperatures and combustion variables, namely typical emission components, heat output, and efficiency. For this, data acquired from four small-scale combustion units and a large circulating fluidised bed boiler was studied. The fuel range varied from wood logs, wood chips, and wood pellets to biomass residue. Original signals and a defined set of their mathematical transformations were applied to data analysis. In order to evaluate the strength of the correlations, a multivariate distance measure based on information theory was derived. The analysis further assessed time-varying signal correlations and relative time delays. Ranking of the analysis results was based on the distance measure. The uniformity of the correlations in the different data sets was studied by comparing the 10-quantiles of the measured signal. The method was validated with two benchmark data sets. The flue gas temperatures and the combustion variables measured carried similar information. The strongest correlations were mainly linear with the transformed signal combinations and explicable by the combustion theory. Remarkably, the results showed uniformity of the correlations across the data sets with several signal transformations. This was also indicated by simulations using a linear model with constant structure to monitor carbon dioxide in flue gas. Acceptable performance was observed according to three validation criteria used to quantify modelling error in each data set. In general, the findings demonstrate that the presented signal transformations enable real-time approximation of the studied
Decoherence-induced transition from photon correlation to anti-correlation

International Nuclear Information System (INIS)

Xu, Q

2014-01-01

Decoherence tends to induce the quantum-to-classical transition, which leads to a crucial obstacle in the realization of reliable quantum information processing. Counterintuitively, we propose that the decoherence due to phase decay brings about the switch from photon correlation to anti-correlation. Stronger decoherence also gives rise to an enhancement of the transition from photon correlation to anti-correlation. This breaks the conventional correlation of strong decoherence with fast decorrelation. (letters)
Quantifying the range of cross-correlated fluctuations using a q- L dependent AHXA coefficient

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Wang, Fang; Wang, Lin; Chen, Yuming

2018-03-01

Recently, based on analogous height cross-correlation analysis (AHXA), a cross-correlation coefficient ρ×(L) has been proposed to quantify the levels of cross-correlation on different temporal scales for bivariate series. A limitation of this coefficient is that it cannot capture the full information of cross-correlations on amplitude of fluctuations. In fact, it only detects the cross-correlation at a specific order fluctuation, which might neglect some important information inherited from other order fluctuations. To overcome this disadvantage, in this work, based on the scaling of the qth order covariance and time delay L, we define a two-parameter dependent cross-correlation coefficient ρq(L) to detect and quantify the range and level of cross-correlations. This new version of ρq(L) coefficient leads to the formation of a ρq(L) surface, which not only is able to quantify the level of cross-correlations, but also allows us to identify the range of fluctuation amplitudes that are correlated in two given signals. Applications to the classical ARFIMA models and the binomial multifractal series illustrate the feasibility of this new coefficient ρq(L) . In addition, a statistical test is proposed to quantify the existence of cross-correlations between two given series. Applying our method to the real life empirical data from the 1999-2000 California electricity market, we find that the California power crisis in 2000 destroys the cross-correlation between the price and the load series but does not affect the correlation of the load series during and before the crisis.
Quantifying meta-correlations in financial markets

Science.gov (United States)

Kenett, Dror Y.; Preis, Tobias; Gur-Gershgoren, Gitit; Ben-Jacob, Eshel

2012-08-01

Financial markets are modular multi-level systems, in which the relationships between the individual components are not constant in time. Sudden changes in these relationships significantly affect the stability of the entire system, and vice versa. Our analysis is based on historical daily closing prices of the 30 components of the Dow Jones Industrial Average (DJIA) from March 15th, 1939 until December 31st, 2010. We quantify the correlation among these components by determining Pearson correlation coefficients, to investigate whether mean correlation of the entire portfolio can be used as a precursor for changes in the index return. To this end, we quantify the meta-correlation - the correlation of mean correlation and index return. We find that changes in index returns are significantly correlated with changes in mean correlation. Furthermore, we study the relationship between the index return and correlation volatility - the standard deviation of correlations for a given time interval. This parameter provides further evidence of the effect of the index on market correlations and their fluctuations. Our empirical findings provide new information and quantification of the index leverage effect, and have implications to risk management, portfolio optimization, and to the increased stability of financial markets.
Mimicking anti-correlations with classical interference

International Nuclear Information System (INIS)

Godoy, S; Seifert, B; Wallentowitz, S

2013-01-01

It is shown how classical laser light impinging on a beam splitter with internal reflections may mimic anti-correlations of the detected outputs, similar to those observed for anti-bunched light. The experimentally observed anti-correlation may be interpreted as a classical Hong–Ou–Mandel dip. (paper)
Two-particle correlations from droplet formation in high multiplicity anti pp events

International Nuclear Information System (INIS)

Ruuskanen, P.V.; Seibert, D.

1988-01-01

We study the correlations that arise from the formation of plasma droplets in high multiplicity events observed in recent FNAL anti pp collisions at √s=1.8 TeV. We show how the correlation between the final particles depends on the droplet size and density and on correlations between the droplets. We find that the two-particle correlation function R 2 could provide a clear signal for the formation of droplets. (orig.)
Quantification of the impact of a confounding variable on functional connectivity confirms anti-correlated networks in the resting-state.

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Carbonell, F; Bellec, P; Shmuel, A

2014-02-01

The effect of regressing out the global average signal (GAS) in resting state fMRI data has become a concern for interpreting functional connectivity analyses. It is not clear whether the reported anti-correlations between the Default Mode and the Dorsal Attention Networks are intrinsic to the brain, or are artificially created by regressing out the GAS. Here we introduce a concept, Impact of the Global Average on Functional Connectivity (IGAFC), for quantifying the sensitivity of seed-based correlation analyses to the regression of the GAS. This voxel-wise IGAFC index is defined as the product of two correlation coefficients: the correlation between the GAS and the fMRI time course of a voxel, times the correlation between the GAS and the seed time course. This definition enables the calculation of a threshold at which the impact of regressing-out the GAS would be large enough to introduce spurious negative correlations. It also yields a post-hoc impact correction procedure via thresholding, which eliminates spurious correlations introduced by regressing out the GAS. In addition, we introduce an Artificial Negative Correlation Index (ANCI), defined as the absolute difference between the IGAFC index and the impact threshold. The ANCI allows a graded confidence scale for ranking voxels according to their likelihood of showing artificial correlations. By applying this method, we observed regions in the Default Mode and Dorsal Attention Networks that were anti-correlated. These findings confirm that the previously reported negative correlations between the Dorsal Attention and Default Mode Networks are intrinsic to the brain and not the result of statistical manipulations. Our proposed quantification of the impact that a confound may have on functional connectivity can be generalized to global effect estimators other than the GAS. It can be readily applied to other confounds, such as systemic physiological or head movement interferences, in order to quantify their
Buspirone anti-dyskinetic effect is correlated with temporal normalization of dysregulated striatal DRD1 signalling in L-DOPA-treated rats.

Science.gov (United States)

Azkona, Garikoitz; Sagarduy, Ainhoa; Aristieta, Asier; Vazquez, Nerea; Zubillaga, Verónica; Ruíz-Ortega, José Angel; Pérez-Navarro, Esther; Ugedo, Luisa; Sánchez-Pernaute, Rosario

2014-04-01

Dopamine replacement with l-DOPA is the most effective therapy in Parkinson's disease. However, with chronic treatment, half of the patients develop an abnormal motor response including dyskinesias. The specific molecular mechanisms underlying dyskinesias are not fully understood. In this study, we used a well-characterized animal model to first establish the molecular differences between rats that did and did not develop dyskinesias. We then investigated the molecular substrates implicated in the anti-dyskinetic effect of buspirone, a 5HT1A partial agonist. Striatal protein expression profile of dyskinetic animals revealed increased levels of the dopamine receptor (DR)D3, ΔFosB and phospho (p)CREB, as well as an over-activation of the DRD1 signalling pathway, reflected by elevated ratios of phosphorylated DARPP32 and ERK2. Buspirone reduced the abnormal involuntary motor response in dyskinetic rats in a dose-dependent fashion. Buspirone (4 mg/kg) dramatically reduced the presence and severity of dyskinesias (by 83%) and normalized DARPP32 and ERK2 phosphorylation ratios, while the increases in DRD3, ΔFosB and pCREB observed in dyskinetic rats were not modified. Pharmacological experiments combining buspirone with 5HT1A and DRD3 antagonists confirmed that normalization of both pDARPP32 and pERK2 is required, but not sufficient, for blocking dyskinesias. The correlation between pDARPP32 ratio and dyskinesias was significant but not strong, pointing to the involvement of convergent factors and signalling pathways. Our results suggest that in dyskinetic rats DRD3 striatal over-expression could be instrumental in the activation of DRD1-downstream signalling and demonstrate that the anti-dyskinetic effect of buspirone in this model is correlated with DRD1 pathway normalization. Copyright © 2013 Elsevier Ltd. All rights reserved.
Measurement of b anti b correlations at the CERN p anti p collider

International Nuclear Information System (INIS)

Albajar, C.; Ankoviak, K.; Bartha, S.; Bezaguet, A.; Boehrer, A.; Bos, K.; Buchanan, C.; Buschbeck, B.; Castilla-Valdez, H.; Cennini, P.; Cittolin, S.; Clayton, E.; Cline, D.; Caughlan, J.A.; Dau, D.; Daum, C.; Della Negra, M.; Demoulin, M.; Denegri, D.; Dibon, H.; Dorenbosch, J.; Dowell, J.D.; Eggert, K.; Eisenhandler, E.; Ellis, N.; Evans, H.; Faissner, H.; Fensome, I.F.; Fortson, L.; Garvey, J.; Geiser, A. Givernaud, A.; Gonidec, A.; Gonzalez, B.; Gronberg, J.; Holthuizen, D.J.; Jank, W.; Jorat, G.; Kalmus, P.I.P.; Karimaeki, V.; Kenyon, I.; Kinnunen, R.; Krammer, M.; Lammel, S.; Landon, M.P.J.; Lemoigne, Y.; Levegruen, S.; Lipa, P.; Markou, C.; Markytan, M.; Maurin, G.; McMahon, S.; Merlo, J.P.; Meyer, T.; Moers, T.; Mohammadi, M.; Morsch, A.; Moulin, A.; Norton, A.; Otwinowski, S.; Pancheri, G.; Pietarinen, E.; Pimiae, M.; Placci, A.; Porte, J.P.; Priem, R.; Prosi, R.; Radermacher, E.; Rauschkolb, M.; Reithler, H.; Revol, J.P.; Robinson, D.; Rubbia, C.; Samyn, D.; Schinzel, D.; Schleichert, R.; Schroeder, M.; Seez, C.; Shah, T.P.; Sphicas, P.; Sumorok, K.; Szoncso, F.; Tan, C.H.; Taurok, A.; Taylor, L.; Tether, S.; Teykal, H.; Thompson, G.; Tuchscherer, H.; Tuominiemi, J.; Van de Guchte, W.; Van Dijk, A.; Vargas, M.; Virdee, T.S.; Schlippe, W. von; Vuillemin, V.; Wacker, K.; Wagner, H.; Walzel, G.; Wulz, C.E.; Zotto, P.; NIKHEF-H, Amsterdam; Birmingham Univ.; CERN, Geneva; Helsinki Univ.; Kiel Univ.; Blackett Lab., Imperial Coll., London; Queen Mary and Westfield Coll., London; MIT, Cambridge, MA; Rutherford Appleton Lab., Chilton; DPHPE/SEPh, CEN Saclay, Gif-sur-Yvette; California Univ., Los Angeles, CA; Oesterreichische Akademie der Wissenschaften, Vienna

1994-01-01

We report on measurements of correlated b anti b production in p anti p at √s=630 GeV, using dimuon data to tag both the b and anti b quarks. Starting from an inclusive dimuon sample we obtain improved cross-sections for single inclusive beauty production and confirm our earlier results on B 0 - anti B 0 mixing. From a study of b anti b correlations we derive explicit cross-sections for semi-differential b anti b production. We compare the measured cross-sections and correlations to OMIKRON (α s 3 ) QCD predictions and find good quantitative agreement. From the measured angular distributions we establish a sizeable contribution from higher order QCD processes with a significance of about seven standard deviations. A large nonperturbative contribution to these higher order corrections is excluded. (orig.)
Stress Redistribution Explains Anti-correlated Subglacial Pressure Variations

Directory of Open Access Journals (Sweden)

Pierre-Marie Lefeuvre

2018-01-01

Full Text Available We used a finite element model to interpret anti-correlated pressure variations at the base of a glacier to demonstrate the importance of stress redistribution in the basal ice. We first investigated two pairs of load cells installed 20 m apart at the base of the 210 m thick Engabreen glacier in Northern Norway. The load cell data for July 2003 showed that pressurisation of a subglacial channel located over one load cell pair led to anti-correlation in pressure between the two pairs. To investigate the cause of this anti-correlation, we used a full Stokes 3D model of a 210 m thick and 25–200 m wide glacier with a pressurised subglacial channel represented as a pressure boundary condition. The model reproduced the anti-correlated pressure response at the glacier bed and variations in pressure of the same order of magnitude as the load cell observations. The anti-correlation pattern was shown to depend on the bed/surface slope. On a flat bed with laterally constrained cross-section, the resulting bridging effect diverted some of the normal forces acting on the bed to the sides. The anti-correlated pressure variations were then reproduced at a distance >10–20 m from the channel. In contrast, when the bed was inclined, the channel support of the overlying ice was vertical only, causing a reduction of the normal stress on the bed. With a bed slope of 5 degrees, the anti-correlation occurred within 10 m of the channel. The model thus showed that the effect of stress redistribution can lead to an opposite response in pressure at the same distance from the channel and that anti-correlation in pressure is reproduced without invoking cavity expansion caused by sliding.
Anti-correlations in the degree distribution increase stimulus detection performance in noisy spiking neural networks.

Science.gov (United States)

Martens, Marijn B; Houweling, Arthur R; E Tiesinga, Paul H

2017-02-01

Neuronal circuits in the rodent barrel cortex are characterized by stable low firing rates. However, recent experiments show that short spike trains elicited by electrical stimulation in single neurons can induce behavioral responses. Hence, the underlying neural networks provide stability against internal fluctuations in the firing rate, while simultaneously making the circuits sensitive to small external perturbations. Here we studied whether stability and sensitivity are affected by the connectivity structure in recurrently connected spiking networks. We found that anti-correlation between the number of afferent (in-degree) and efferent (out-degree) synaptic connections of neurons increases stability against pathological bursting, relative to networks where the degrees were either positively correlated or uncorrelated. In the stable network state, stimulation of a few cells could lead to a detectable change in the firing rate. To quantify the ability of networks to detect the stimulation, we used a receiver operating characteristic (ROC) analysis. For a given level of background noise, networks with anti-correlated degrees displayed the lowest false positive rates, and consequently had the highest stimulus detection performance. We propose that anti-correlation in the degree distribution may be a computational strategy employed by sensory cortices to increase the detectability of external stimuli. We show that networks with anti-correlated degrees can in principle be formed by applying learning rules comprised of a combination of spike-timing dependent plasticity, homeostatic plasticity and pruning to networks with uncorrelated degrees. To test our prediction we suggest a novel experimental method to estimate correlations in the degree distribution.
Quantifying the non-Gaussianity in the EoR 21-cm signal through bispectrum

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Majumdar, Suman; Pritchard, Jonathan R.; Mondal, Rajesh; Watkinson, Catherine A.; Bharadwaj, Somnath; Mellema, Garrelt

2018-05-01

The epoch of reionization (EoR) 21-cm signal is expected to be highly non-Gaussian in nature and this non-Gaussianity is also expected to evolve with the progressing state of reionization. Therefore the signal will be correlated between different Fourier modes (k). The power spectrum will not be able capture this correlation in the signal. We use a higher order estimator - the bispectrum - to quantify this evolving non-Gaussianity. We study the bispectrum using an ensemble of simulated 21-cm signal and with a large variety of k triangles. We observe two competing sources driving the non-Gaussianity in the signal: fluctuations in the neutral fraction (x_{H I}) field and fluctuations in the matter density field. We find that the non-Gaussian contribution from these two sources varies, depending on the stage of reionization and on which k modes are being studied. We show that the sign of the bispectrum works as a unique marker to identify which among these two components is driving the non-Gaussianity. We propose that the sign change in the bispectrum, when plotted as a function of triangle configuration cos θ and at a certain stage of the EoR can be used as a confirmative test for the detection of the 21-cm signal. We also propose a new consolidated way to visualize the signal evolution (with evolving \\bar{x}_{H I} or redshift), through the trajectories of the signal in a power spectrum and equilateral bispectrum i.e. P(k) - B(k, k, k) space.
Signatures of Quantum Transport Through Two-Dimensional Structures With Correlated and Anti-Correlated Interfaces

OpenAIRE

Low, Tony; Ansari, Davood

2008-01-01

Electronic transport through a 2D deca-nanometer length channel with correlated and anti-correlated surfaces morphologies is studied using the Keldysh non-equilibrium Green function technique. Due to the pseudo-periodicity of these structures, the energy-resolved transmission possesses pseudo-bands and pseudo-gaps. Channels with correlated surfaces exhibit wider pseudo-bands than their anti-correlated counterparts. By surveying channels with various combinations of material parameters, we fou...

Effects of Perfectly Correlated and Anti-Correlated Noise in a Logistic Growth Model

International Nuclear Information System (INIS)

Zhang Li; Cao Li

2011-01-01

The logistic growth model with correlated additive and multiplicative Gaussian white noise is used to analyze tumor cell population. The effects of perfectly correlated and anti-correlated noise on the stationary properties of tumor cell population are studied. As in both cases the diffusion coefficient has zero point in real number field, some special features of the system are arisen. It is found that in both cases, the increase of the multiplicative noise intensity cause tumor cell extinction. In the perfectly anti-correlated case, the stationary probability distribution as a function of tumor cell population exhibit two extrema. (general)
OPTIMAL CORRELATION ESTIMATORS FOR QUANTIZED SIGNALS

International Nuclear Information System (INIS)

Johnson, M. D.; Chou, H. H.; Gwinn, C. R.

2013-01-01

Using a maximum-likelihood criterion, we derive optimal correlation strategies for signals with and without digitization. We assume that the signals are drawn from zero-mean Gaussian distributions, as is expected in radio-astronomical applications, and we present correlation estimators both with and without a priori knowledge of the signal variances. We demonstrate that traditional estimators of correlation, which rely on averaging products, exhibit large and paradoxical noise when the correlation is strong. However, we also show that these estimators are fully optimal in the limit of vanishing correlation. We calculate the bias and noise in each of these estimators and discuss their suitability for implementation in modern digital correlators.
OPTIMAL CORRELATION ESTIMATORS FOR QUANTIZED SIGNALS

Energy Technology Data Exchange (ETDEWEB)

Johnson, M. D.; Chou, H. H.; Gwinn, C. R., E-mail: michaeltdh@physics.ucsb.edu, E-mail: cgwinn@physics.ucsb.edu [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

2013-03-10

Using a maximum-likelihood criterion, we derive optimal correlation strategies for signals with and without digitization. We assume that the signals are drawn from zero-mean Gaussian distributions, as is expected in radio-astronomical applications, and we present correlation estimators both with and without a priori knowledge of the signal variances. We demonstrate that traditional estimators of correlation, which rely on averaging products, exhibit large and paradoxical noise when the correlation is strong. However, we also show that these estimators are fully optimal in the limit of vanishing correlation. We calculate the bias and noise in each of these estimators and discuss their suitability for implementation in modern digital correlators.
Wavelet Correlation Coefficient of 'strongly correlated' financial time series

OpenAIRE

Razdan, Ashok

2003-01-01

In this paper we use wavelet concepts to show that correlation coefficient between two financial data's is not constant but varies with scale from high correlation value to strongly anti-correlation value This studies is important because correlation coefficient is used to quantify degree of independence between two variables. In econophysics correlation coefficient forms important input to evolve hierarchial tree and minimum spanning tree of financial data.
Anti-carbamylated Protein Antibody Levels Correlate with Anti-Sa (Citrullinated Vimentin) Antibody Levels in Rheumatoid Arthritis.

Science.gov (United States)

Challener, Gregory J; Jones, Jonathan D; Pelzek, Adam J; Hamilton, B JoNell; Boire, Gilles; de Brum-Fernandes, Artur José; Masetto, Ariel; Carrier, Nathalie; Ménard, Henri A; Silverman, Gregg J; Rigby, William F C

2016-02-01

The presence of anticitrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) indicates a breach in immune tolerance. Recent studies indicate that this breach extends to homocitrullination of lysines with the formation of anti-carbamylated protein (anti-CarP) antibodies. We analyzed the clinical and serologic relationships of anti-CarP in 2 RA cohorts. Circulating levels of immunoglobulin G anti-CarP antibodies were determined by ELISA in established (Dartmouth-Hitchcock Medical Center) and early (Sherbrooke University Hospital Center) cohorts and evaluated for anticyclic citrullinated peptide antibodies (anti-CCP), specific ACPA, and rheumatoid factor (RF) levels using the Student t test and correlation analysis. We identified elevated anti-CarP antibodies titers in 47.0% of seropositive patients (Dartmouth, n = 164), with relationships to anti-CCP (p < 0.0001) and IgM-RF (p = 0.001). Similarly, 38.2% of seropositive patients from the Sherbrooke cohort (n = 171) had elevated anti-CarP antibodies; titers correlated to anti-CCP (p = 0.01) but not IgM-RF (p = 0.09). A strong correlation with anti-Sa was observed: 47.9% anti-Sa+ patients were anti-CarP antibodies+ versus only 25.4% anti-Sa- in the Sherbrooke cohort (p = 0.0002), and 62.6% anti-Sa+ patients versus 26.9% anti-Sa- were anti-CarP antibodies+ in Dartmouth (p < 0.0001). We found a more variable response for reactivity to citrullinated fibrinogen or to citrullinated peptides from fibrinogen and α enolase. In 2 North American RA cohorts, we observed a high prevalence of anti-CarP antibody positivity. We also describe a surprising and unexpected association of anti-CarP with anti-Sa antibodies that could not be explained by cross-reactivity. Further, considerable heterogeneity exists between anti-CarP reactivity and other citrullinated peptide reactivity, raising the question of how the pathogenesis of antibody responses for carbamylated proteins and citrullinated proteins may be linked in vivo.
Observation of correlated anti-Stokes emissions by multiwave mixing in sodium vapor

International Nuclear Information System (INIS)

Motomura, Koji; Tsukamoto, Mayumi; Wakiyama, Akira; Harada, Ken-ichi; Mitsunaga, Masaharu

2005-01-01

We study experimentally nonlinear optical processes in which Stokes and anti-Stokes fields build up under strong, resonant, counterpropagating pump laser excitation in atomic sodium vapor. We find that, at some pump frequency, two off-axis anti-Stokes emissions propagating along reflection-symmetric directions are strongly temporally correlated, with a correlation time of 0.5 μs and a correlation range of 1 mrad. It is shown by the numerical analysis based on six-wave mixing process involving pump, Stokes, and anti-Stokes waves in the forward and the backward directions that such correlated anti-Stokes emissions are possible when the medium is opaque for the Stokes field and transparent for the anti-Stokes field. Possibilities of quantum correlation for entangled photon generation using this system are discussed
Spectral Correlation of Multicarrier Modulated Signals and Its Application for Signal Detection

Directory of Open Access Journals (Sweden)

Zhang Haijian

2010-01-01

Full Text Available Spectral correlation theory for cyclostationary time-series signals has been studied for decades. Explicit formulas of spectral correlation function for various types of analog-modulated and digital-modulated signals are already derived. In this paper, we investigate and exploit the cyclostationarity characteristics for two kinds of multicarrier modulated (MCM signals: conventional OFDM and filter bank based multicarrier (FBMC signals. The spectral correlation characterization of MCM signal can be described by a special linear periodic time-variant (LPTV system. Using this LPTV description, we have derived the explicit theoretical formulas of nonconjugate and conjugate cyclic autocorrelation function (CAF and spectral correlation function (SCF for OFDM and FBMC signals. According to theoretical spectral analysis, Cyclostationary Signatures (CS are artificially embedded into MCM signal and a low-complexity signature detector is, therefore, presented for detecting MCM signal. Theoretical analysis and simulation results demonstrate the efficiency and robustness of this CS detector compared to traditionary energy detector.
Diametrical clustering for identifying anti-correlated gene clusters.

Science.gov (United States)

Dhillon, Inderjit S; Marcotte, Edward M; Roshan, Usman

2003-09-01

Clustering genes based upon their expression patterns allows us to predict gene function. Most existing clustering algorithms cluster genes together when their expression patterns show high positive correlation. However, it has been observed that genes whose expression patterns are strongly anti-correlated can also be functionally similar. Biologically, this is not unintuitive-genes responding to the same stimuli, regardless of the nature of the response, are more likely to operate in the same pathways. We present a new diametrical clustering algorithm that explicitly identifies anti-correlated clusters of genes. Our algorithm proceeds by iteratively (i). re-partitioning the genes and (ii). computing the dominant singular vector of each gene cluster; each singular vector serving as the prototype of a 'diametric' cluster. We empirically show the effectiveness of the algorithm in identifying diametrical or anti-correlated clusters. Testing the algorithm on yeast cell cycle data, fibroblast gene expression data, and DNA microarray data from yeast mutants reveals that opposed cellular pathways can be discovered with this method. We present systems whose mRNA expression patterns, and likely their functions, oppose the yeast ribosome and proteosome, along with evidence for the inverse transcriptional regulation of a number of cellular systems.
An Adaptive Model for Calculating the Correlation Degree of Multiple Adjacent Signalized Intersections

Directory of Open Access Journals (Sweden)

Linhong Wang

2013-01-01

Full Text Available As an important component of the urban adaptive traffic control system, subarea partition algorithm divides the road network into some small subareas and then determines the optimal signal control mode for each signalized intersection. Correlation model is the core of subarea partition algorithm because it can quantify the correlation degree of adjacent signalized intersections and decides whether these intersections can be grouped into one subarea. In most cases, there are more than two intersections in one subarea. However, current researches only focus on the correlation model for two adjacent intersections. The objective of this study is to develop a model which can calculate the correlation degree of multiple intersections adaptively. The cycle lengths, link lengths, number of intersections, and path flow between upstream and downstream coordinated phases were selected as the contributing factors of the correlation model. Their jointly impacts on the performance of the coordinated control mode relative to the isolated control mode were further studied using numerical experiments. The paper then proposed a correlation index (CI as an alternative to relative performance. The relationship between CI and the four contributing factors was established in order to predict the correlation, which determined whether adjacent intersections could be partitioned into one subarea. A value of 0 was set as the threshold of CI. If CI was larger than 0, multiple intersections could be partitioned into one subarea; otherwise, they should be separated. Finally, case studies were conducted in a real-life signalized network to evaluate the performance of the model. The results show that the CI simulates the relative performance well and could be a reliable index for subarea partition.
Pion correlation from Skyrmion--anti-Skyrmion annihilation

International Nuclear Information System (INIS)

Lu, Y.; Amado, R.D.

1995-01-01

We study two pion correlations from Skyrmion and anti-Skyrmion collision, using the product ansatz and an approximate random grooming method for nucleon projection. The spatial-isospin coupling inherent in the Skyrme model, along with empirical averages, leads to correlations not only among pions of like charges but also among unlike charge types
Reversed stereo depth and motion direction with anti-correlated stimuli.

Science.gov (United States)

Read, J C; Eagle, R A

2000-01-01

We used anti-correlated stimuli to compare the correspondence problem in stereo and motion. Subjects performed a two-interval forced-choice disparity/motion direction discrimination task for different displacements. For anti-correlated 1d band-pass noise, we found weak reversed depth and motion. With 2d anti-correlated stimuli, stereo performance was impaired, but the perception of reversed motion was enhanced. We can explain the main features of our data in terms of channels tuned to different spatial frequencies and orientation. We suggest that a key difference between the solution of the correspondence problem by the motion and stereo systems concerns the integration of information at different orientations.
Correlation of mRNA Expression and Signal Variability in Chronic Intracortical Electrodes.

Science.gov (United States)

Falcone, Jessica D; Carroll, Sheridan L; Saxena, Tarun; Mandavia, Dev; Clark, Alexus; Yarabarla, Varun; Bellamkonda, Ravi V

2018-01-01

The goal for this research was to identify molecular mechanisms that explain animal-to-animal variability in chronic intracortical recordings. Microwire electrodes were implanted into Sprague Dawley rats at an acute (1 week) and a chronic (14 weeks) time point. Weekly recordings were conducted, and action potentials were evoked in the barrel cortex by deflecting the rat's whiskers. At 1 and 14 weeks, tissue was collected, and mRNA was extracted. mRNA expression was compared between 1 and 14 weeks using a high throughput multiplexed qRT-PCR. Pearson correlation coefficients were calculated between mRNA expression and signal-to-noise ratios at 14 weeks. At 14 weeks, a positive correlation between signal-to-noise ratio (SNR) and NeuN and GFAP mRNA expression was observed, indicating a relationship between recording strength and neuronal population, as well as reactive astrocyte activity. The inflammatory state around the electrode interface was evaluated using M1-like and M2-like markers. Expression for both M1-like and M2-like mRNA markers remained steady from 1 to 14 weeks. Anti-inflammatory markers, CD206 and CD163, however, demonstrated a significant positive correlation with SNR quality at 14 weeks. VE-cadherin, a marker for adherens junctions, and PDGFR-β, a marker for pericytes, both partial representatives of blood-brain barrier health, had a positive correlation with SNR at 14 weeks. Endothelial adhesion markers revealed a significant increase in expression at 14 weeks, while CD45, a pan-leukocyte marker, significantly decreased at 14 weeks. No significant correlation was found for either the endothelial adhesion or pan-leukocyte markers. A positive correlation between anti-inflammatory and blood-brain barrier health mRNA markers with electrophysiological efficacy of implanted intracortical electrodes has been demonstrated. These data reveal potential mechanisms for further evaluation to determine potential target mechanisms to improve
Investigating the time-correlation properties in self-potential signals recorded in a seismic area of Irpinia, southern Italy

International Nuclear Information System (INIS)

Telesca, Luciano; Balasco, Marianna; Lapenna, Vincenzo

2007-01-01

Recent studies have shown that many natural phenomena are characterized by temporal fluctuations with long-range power-law correlations, suggesting a fractal geometry of the underlying dynamical system. The presence of power-law correlations are detected in four time series of self-potential signals, measured in a seismic area of southern Italy, by means of the Detrended Fluctuation Analysis (DFA), a method that permits the detection of long-range correlations in nonstationary time series. Results show scaling behaviour for all the signals recorded, indicating the presence of fractal features expressing a long-term correlation quantified by the numerical value of the scaling exponents. Our findings suggest a possible correlation between the earthquakes occurred in the area investigated and the relative maxima/minima of the mean and the standard deviation of the scaling exponents. Furthermore, the normalized average and standard deviation curves for all the signals tend to converge in correspondence with an earthquake
Global and system-specific resting-state fMRI fluctuations are uncorrelated: principal component analysis reveals anti-correlated networks.

Science.gov (United States)

Carbonell, Felix; Bellec, Pierre; Shmuel, Amir

2011-01-01

The influence of the global average signal (GAS) on functional-magnetic resonance imaging (fMRI)-based resting-state functional connectivity is a matter of ongoing debate. The global average fluctuations increase the correlation between functional systems beyond the correlation that reflects their specific functional connectivity. Hence, removal of the GAS is a common practice for facilitating the observation of network-specific functional connectivity. This strategy relies on the implicit assumption of a linear-additive model according to which global fluctuations, irrespective of their origin, and network-specific fluctuations are super-positioned. However, removal of the GAS introduces spurious negative correlations between functional systems, bringing into question the validity of previous findings of negative correlations between fluctuations in the default-mode and the task-positive networks. Here we present an alternative method for estimating global fluctuations, immune to the complications associated with the GAS. Principal components analysis was applied to resting-state fMRI time-series. A global-signal effect estimator was defined as the principal component (PC) that correlated best with the GAS. The mean correlation coefficient between our proposed PC-based global effect estimator and the GAS was 0.97±0.05, demonstrating that our estimator successfully approximated the GAS. In 66 out of 68 runs, the PC that showed the highest correlation with the GAS was the first PC. Since PCs are orthogonal, our method provides an estimator of the global fluctuations, which is uncorrelated to the remaining, network-specific fluctuations. Moreover, unlike the regression of the GAS, the regression of the PC-based global effect estimator does not introduce spurious anti-correlations beyond the decrease in seed-based correlation values allowed by the assumed additive model. After regressing this PC-based estimator out of the original time-series, we observed robust anti-correlations
Selecting the optimal anti-aliasing filter for multichannel biosignal acquisition intended for inter-signal phase shift analysis

International Nuclear Information System (INIS)

Keresnyei, Róbert; Hejjel, László; Megyeri, Péter; Zidarics, Zoltán

2015-01-01

The availability of microcomputer-based portable devices facilitates the high-volume multichannel biosignal acquisition and the analysis of their instantaneous oscillations and inter-signal temporal correlations. These new, non-invasively obtained parameters can have considerable prognostic or diagnostic roles. The present study investigates the inherent signal delay of the obligatory anti-aliasing filters. One cycle of each of the 8 electrocardiogram (ECG) and 4 photoplethysmogram signals from healthy volunteers or artificially synthesised series were passed through 100–80–60–40–20 Hz 2–4–6–8th order Bessel and Butterworth filters digitally synthesized by bilinear transformation, that resulted in a negligible error in signal delay compared to the mathematical model of the impulse- and step responses of the filters. The investigated filters have as diverse a signal delay as 2–46 ms depending on the filter parameters and the signal slew rate, which is difficult to predict in biological systems and thus difficult to compensate for. Its magnitude can be comparable to the examined phase shifts, deteriorating the accuracy of the measurement. As a conclusion, identical or very similar anti-aliasing filters with lower orders and higher corner frequencies, oversampling, and digital low pass filtering are recommended for biosignal acquisition intended for inter-signal phase shift analysis. (note)
Influence of meditation on anti-correlated networks in the brain

Directory of Open Access Journals (Sweden)

Zoran eJosipovic

2012-01-01

Full Text Available Human experience can be broadly divided into those that are external and related to interaction with the environment, and experiences that are internal and self-related. The cerebral cortex appears to be divided into two corresponding systems: an extrinsic system composed of brain areas that respond more to external stimuli and tasks and an intrinsic system composed of brain areas that respond less to external stimuli and tasks. These two broad brain systems seem to compete with each other, such that their activity levels over time is usually anti-correlated, even when subjects are at rest and not performing any task. This study used meditation as an experimental manipulation to test whether this competition (anti-correlation can be modulated by cognitive strategy. Participants either fixated without meditation (fixation, or engaged in nondual awareness (NDA or focused attention (FA meditations. We computed inter-area correlations (functional connectivity between pairs of brain regions within each system, and between the entire extrinsic and intrinsic systems. Anti-correlation between extrinsic vs. intrinsic systems was stronger during FA meditation and weaker during NDA meditation in comparison to fixation (without mediation. However, correlation between areas within each system did not change across conditions. These results suggest that the anti-correlation found between extrinsic and intrinsic systems is not an immutable property of brain organization and that practicing different forms of meditation can modulate this gross functional organization in profoundly different ways.
Influence of meditation on anti-correlated networks in the brain.

Science.gov (United States)

Josipovic, Zoran; Dinstein, Ilan; Weber, Jochen; Heeger, David J

2011-01-01

Human experiences can be broadly divided into those that are external and related to interaction with the environment, and experiences that are internal and self-related. The cerebral cortex appears to be divided into two corresponding systems: an "extrinsic" system composed of brain areas that respond more to external stimuli and tasks and an "intrinsic" system composed of brain areas that respond less to external stimuli and tasks. These two broad brain systems seem to compete with each other, such that their activity levels over time is usually anti-correlated, even when subjects are "at rest" and not performing any task. This study used meditation as an experimental manipulation to test whether this competition (anti-correlation) can be modulated by cognitive strategy. Participants either fixated without meditation (fixation), or engaged in non-dual awareness (NDA) or focused attention (FA) meditations. We computed inter-area correlations ("functional connectivity") between pairs of brain regions within each system, and between the entire extrinsic and intrinsic systems. Anti-correlation between extrinsic vs. intrinsic systems was stronger during FA meditation and weaker during NDA meditation in comparison to fixation (without mediation). However, correlation between areas within each system did not change across conditions. These results suggest that the anti-correlation found between extrinsic and intrinsic systems is not an immutable property of brain organization and that practicing different forms of meditation can modulate this gross functional organization in profoundly different ways.
Simultaneous stability and sensitivity in model cortical networks is achieved through anti-correlations between the in- and out-degree of connectivity

Directory of Open Access Journals (Sweden)

Juan Carlos Vasquez

2013-11-01

Full Text Available Neuronal networks in rodent barrel cortex are characterized by stable low baseline firing rates. However, they are sensitive to the action potentials of single neurons as suggested by recent single-cell stimulation experiments that report quantifiable behavioral responses in response to short spike trains elicited in single neurons. Hence, these networks are stable against internally generated fluctuations in firing rate but at the same time remain sensitive to similarly-sized externally induced perturbations. We investigated stability and sensitivity in a simple recurrent network of stochastic binary neurons and determined numerically the effects of correlation between the number of afferent (‘in-degree’ and efferent (‘out-degree’ connections in neurons. The key advance reported in this work is that anti-correlation between in-/out-degree distributions increased the stability of the network in comparison to networks with no correlation or positive correlations, while being able to achieve the same level of sensitivity. The experimental characterization of degree distributions is difficult because all presynaptic and postsynaptic neurons have to be identified and counted. We explored whether the statistics of network motifs, which requires the characterization of connections between small subsets of neurons, could be used to detect evidence for degree anti-correlations. We find that the sample frequency of the 3-neuron ‘ring’ motif (1→2→3→1, can be used to detect degree anti-correlation for sub-networks of size 30 using about 50 samples, which is of significance because the necessary measurements are achievable experimentally in the near future.Taken together, we hypothesize that barrel cortex networks exhibit degree anti-correlations and specific network motif statistics.
Random Walks with Anti-Correlated Steps

OpenAIRE

Wagner, Dirk; Noga, John

2005-01-01

We conjecture the expected value of random walks with anti-correlated steps to be exactly 1. We support this conjecture with 2 plausibility arguments and experimental data. The experimental analysis includes the computation of the expected values of random walks for steps up to 22. The result shows the expected value asymptotically converging to 1.
Anti-synthetase syndrome associated with anti PL-12 and anti-Signal recognition particle antibodies and a necrotizing auto-immune myositis.

Science.gov (United States)

Malkan, Ashish; Cappelen-Smith, Cecilia; Beran, Roy; Griffith, Neil; Toong, Catherine; Wang, Min-Xia; Cordato, Dennis

2015-02-01

We report a 37-year-old woman with a 2 month history of proximal muscle weakness and extremely high creatine kinase (21,808 U/L) due to necrotizing auto-immune myositis (NAM) in association with anti-synthetase syndrome. Myositis-specific auto-immune antibody panel was positive for anti-Signal recognition particle and anti-PL-12. CT scan of the chest confirmed interstitial lung disease. Prednisolone, intravenous immunoglobulin and cyclophosphamide therapy was given with gradual improvement. This patient is notable for the unusual combination of NAM and anti-synthetase syndrome with the rare finding of two myositis-specific autoantibodies, which directed testing for associated extramuscular features and management with more aggressive immunotherapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Correlation between the signal-to-noise ratio improvement factor (KSNR) and clinical image quality for chest imaging with a computed radiography system

International Nuclear Information System (INIS)

Moore, C S; Wood, T J; Saunderson, J R; Beavis, A W

2015-01-01

This work assessed the appropriateness of the signal-to-noise ratio improvement factor (K SNR ) as a metric for the optimisation of computed radiography (CR) of the chest. The results of a previous study in which four experienced image evaluators graded computer simulated chest images using a visual grading analysis scoring (VGAS) scheme to quantify the benefit of using an anti-scatter grid were used for the clinical image quality measurement (number of simulated patients = 80). The K SNR was used to calculate the improvement in physical image quality measured in a physical chest phantom. K SNR correlation with VGAS was assessed as a function of chest region (lung, spine and diaphragm/retrodiaphragm), and as a function of x-ray tube voltage in a given chest region. The correlation of the latter was determined by the Pearson correlation coefficient. VGAS and K SNR image quality metrics demonstrated no correlation in the lung region but did show correlation in the spine and diaphragm/retrodiaphragmatic regions. However, there was no correlation as a function of tube voltage in any region; a Pearson correlation coefficient (R) of −0.93 (p = 0.015) was found for lung, a coefficient (R) of −0.95 (p = 0.46) was found for spine, and a coefficient (R) of −0.85 (p = 0.015) was found for diaphragm. All demonstrate strong negative correlations indicating conflicting results, i.e. K SNR increases with tube voltage but VGAS decreases. Medical physicists should use the K SNR metric with caution when assessing any potential improvement in clinical chest image quality when introducing an anti-scatter grid for CR imaging, especially in the lung region. This metric may also be a limited descriptor of clinical chest image quality as a function of tube voltage when a grid is used routinely. (paper)
Azimuthal correlations in anti pp interactions at 22.4 GeV/c

International Nuclear Information System (INIS)

Reimer, P.

Data are presented on azimuthal two particle correlations and the effect is estimated of resonance production on these correlations in anti pp interactions at 22.4 GeV/c. Attention is paid to correlations between two charged pions produced in the process anti p+p→ two charged pions + anything. The dependence is described of the azimuthal asymmetry parameter on rapidity difference. (Z.J.)
Signal Digitizer and Cross-Correlation Application Specific Integrated Circuit

Science.gov (United States)

Baranauskas, Dalius (Inventor); Baranauskas, Gytis (Inventor); Zelenin, Denis (Inventor); Kangaslahti, Pekka (Inventor); Tanner, Alan B. (Inventor); Lim, Boon H. (Inventor)

2017-01-01

According to one embodiment, a cross-correlator comprises a plurality of analog front ends (AFEs), a cross-correlation circuit and a data serializer. Each of the AFEs comprises a variable gain amplifier (VGA) and a corresponding analog-to-digital converter (ADC) in which the VGA receives and modifies a unique analog signal associates with a measured analog radio frequency (RF) signal and the ADC produces digital data associated with the modified analog signal. Communicatively coupled to the AFEs, the cross-correlation circuit performs a cross-correlation operation on the digital data produced from different measured analog RF signals. The data serializer is communicatively coupled to the summing and cross-correlating matrix and continuously outputs a prescribed amount of the correlated digital data.
No-signaling, perfect bipartite dichotomic correlations and local randomness

International Nuclear Information System (INIS)

Seevinck, M. P.

2011-01-01

The no-signaling constraint on bi-partite correlations is reviewed. It is shown that in order to obtain non-trivial Bell-type inequalities that discern no-signaling correlations from more general ones, one must go beyond considering expectation values of products of observables only. A new set of nontrivial no-signaling inequalities is derived which have a remarkably close resemblance to the CHSH inequality, yet are fundamentally different. A set of inequalities by Roy and Singh and Avis et al., which is claimed to be useful for discerning no-signaling correlations, is shown to be trivially satisfied by any correlation whatsoever. Finally, using the set of newly derived no-signaling inequalities a result with potential cryptographic consequences is proven: if different parties use identical devices, then, once they have perfect correlations at spacelike separation between dichotomic observables, they know that because of no-signaling the local marginals cannot but be completely random.
Correlation of Respiratory Signals and Electrocardiogram Signals via Empirical Mode Decomposition

KAUST Repository

El Fiky, Ahmed Osama

2011-05-24

Recently Electrocardiogram (ECG) signals are being broadly used as an essential diagnosing tool in different clinical applications as they carry a reliable representation not only for cardiac activities, but also for other associated biological processes, like respiration. However, the process of recording and collecting them has usually suffered from the presence of some undesired noises, which in turn affects the reliability of such representations.Therefore, de-noising ECG signals became a hot research field for signal processing experts to ensure better and clear representation of the different cardiac activities. Given the nonlinear and non-stationary properties of ECGs, it is not a simple task to cancel the undesired noise terms without affecting the biological physics of them. In this study, we are interested in correlating the ECG signals with respiratory parameters, specifically the lung volume and lung pressure. We have focused on the concept of de-noising ECG signals by means of signal decomposition using an algorithm called the Empirical Mode Decomposition (EMD) where the original ECG signals are being decomposed into a set of intrinsic mode functions (IMF). Then, we have provided criteria based on which some of these IMFs have been adapted to reconstruct de-noised ECG version. Finally, we have utilized de-noised ECGs as well as IMFs for to study the correlation with lung volume and lung pressure. These correlation studies have showed some clear resemblance especially between the oscillations of ECGs and lung pressures.
Ultrasonic correlator versus signal averager as a signal to noise enhancement instrument

Science.gov (United States)

Kishoni, Doron; Pietsch, Benjamin E.

1989-01-01

Ultrasonic inspection of thick and attenuating materials is hampered by the reduced amplitudes of the propagated waves to a degree that the noise is too high to enable meaningful interpretation of the data. In order to overcome the low Signal to Noise (S/N) ratio, a correlation technique has been developed. In this method, a continuous pseudo-random pattern generated digitally is transmitted and detected by piezoelectric transducers. A correlation is performed in the instrument between the received signal and a variable delayed image of the transmitted one. The result is shown to be proportional to the impulse response of the investigated material, analogous to a signal received from a pulsed system, with an improved S/N ratio. The degree of S/N enhancement depends on the sweep rate. This paper describes the correlator, and compares it to the method of enhancing S/N ratio by averaging the signals. The similarities and differences between the two are highlighted and the potential advantage of the correlator system is explained.
Frontal parietal control network regulates the anti-correlated default and dorsal attention networks.

Science.gov (United States)

Gao, Wei; Lin, Weili

2012-01-01

Recent reports demonstrate the anti-correlated behaviors between the default (DF) and the dorsal attention (DA) networks. We aimed to investigate the roles of the frontal parietal control (FPC) network in regulating the two anti-correlated networks through three experimental conditions, including resting, continuous self-paced/attended sequential finger tapping (FT), and natural movie watching (MW), respectively. The two goal-directed tasks were chosen to engage either one of the two competing networks-FT for DA whereas MW for default. We hypothesized that FPC will selectively augment/suppress either network depending on how the task targets the specific network; FPC will positively correlate with the target network, but negatively correlate with the network anti-correlated with the target network. We further hypothesized that significant causal links from FPC to both DA and DF are present during all three experimental conditions, supporting the initiative regulating role of FPC over the two opposing systems. Consistent with our hypotheses, FPC exhibited a significantly higher positive correlation with DA (P = 0.0095) whereas significantly more negative correlation with default (P = 0.0025) during FT when compared to resting. Completely opposite to that observed during FT, the FPC was significantly anti-correlated with DA (P = 2.1e-6) whereas positively correlated with default (P = 0.0035) during MW. Furthermore, extensive causal links from FPC to both DA and DF were observed across all three experimental states. Together, our results strongly support the notion that the FPC regulates the anti-correlated default and DA networks. Copyright © 2011 Wiley Periodicals, Inc.
Coherent anti-Stokes Raman scattering microscopy of single nanodiamonds

Science.gov (United States)

Pope, Iestyn; Payne, Lukas; Zoriniants, George; Thomas, Evan; Williams, Oliver; Watson, Peter; Langbein, Wolfgang; Borri, Paola

2014-11-01

Nanoparticles have attracted enormous attention for biomedical applications as optical labels, drug-delivery vehicles and contrast agents in vivo. In the quest for superior photostability and biocompatibility, nanodiamonds are considered one of the best choices due to their unique structural, chemical, mechanical and optical properties. So far, mainly fluorescent nanodiamonds have been utilized for cell imaging. However, their use is limited by the efficiency and costs in reliably producing fluorescent defect centres with stable optical properties. Here, we show that single non-fluorescing nanodiamonds exhibit strong coherent anti-Stokes Raman scattering (CARS) at the sp3 vibrational resonance of diamond. Using correlative light and electron microscopy, the relationship between CARS signal strength and nanodiamond size is quantified. The calibrated CARS signal in turn enables the analysis of the number and size of nanodiamonds internalized in living cells in situ, which opens the exciting prospect of following complex cellular trafficking pathways quantitatively.
Coherent anti-Stokes Raman scattering microscopy of single nanodiamonds.

Science.gov (United States)

Pope, Iestyn; Payne, Lukas; Zoriniants, George; Thomas, Evan; Williams, Oliver; Watson, Peter; Langbein, Wolfgang; Borri, Paola

2014-11-01

Nanoparticles have attracted enormous attention for biomedical applications as optical labels, drug-delivery vehicles and contrast agents in vivo. In the quest for superior photostability and biocompatibility, nanodiamonds are considered one of the best choices due to their unique structural, chemical, mechanical and optical properties. So far, mainly fluorescent nanodiamonds have been utilized for cell imaging. However, their use is limited by the efficiency and costs in reliably producing fluorescent defect centres with stable optical properties. Here, we show that single non-fluorescing nanodiamonds exhibit strong coherent anti-Stokes Raman scattering (CARS) at the sp(3) vibrational resonance of diamond. Using correlative light and electron microscopy, the relationship between CARS signal strength and nanodiamond size is quantified. The calibrated CARS signal in turn enables the analysis of the number and size of nanodiamonds internalized in living cells in situ, which opens the exciting prospect of following complex cellular trafficking pathways quantitatively.
(Anti-)deuteron formation and neutron-proton correlation

International Nuclear Information System (INIS)

Mrowczynski, S.

1995-01-01

The neutron-proton correlation, deuteron and antideuteron formation in nuclear collisions are all due to the final state interactions. The neutron-proton correlation function and the (anti-)deuteron formation rate are calculated in parallel. These quantities are expressed through the space-time parameters of the particle source created in nucleus-nucleus collisions. In the case of baryon reach sources, the nucleons are emitted from the whole source volume while the antinucleons dominantly from the surface due to the antinucleon absorption in the baryon environment. Thus, the shape of the antinucleon source is different from the nucleon one, and consequently the antideuteron formation rate is substantially smaller than that one of deuterons. The correlation function satisfies the sum rule, which, in particular, connects the number of correlated neutron-proton pairs with the number of produced deuterons. (author). 18 refs., 4 figs
Correlation anlaysis of plasma fluctuation signals

International Nuclear Information System (INIS)

Wan Baonian; Wang Zhaoshen

1987-01-01

The application of correlation analysis to identify waves and instabilities in plasma is presented. First, the principle of correlation analysis and its application to diagnose plasma fluctuation signals are given. Then, the data acqusition system, application program and calibration method are described. Finally, experimental results from a mirror device are given
Processing of cell-surface signalling anti-sigma factors prior to signal recognition is aconserved autoproteolytic mechanism that produces two functional domains.

NARCIS (Netherlands)

Bastiaansen, K.C.J.T.; Otero-Asman, J.R.; Luirink, J.; Bitter, W.; Llamas, M.A.

2015-01-01

Cell-surface signalling (CSS) enables Gram-negative bacteria to transduce an environmental signal into a cytosolic response. This regulatory cascade involves an outer membrane receptor that transmits the signal to an anti-sigma factor in the cytoplasmic membrane, allowing the activation of an
Particle image velocimetry correlation signal-to-noise ratio metrics and measurement uncertainty quantification

International Nuclear Information System (INIS)

Xue, Zhenyu; Charonko, John J; Vlachos, Pavlos P

2014-01-01

In particle image velocimetry (PIV) the measurement signal is contained in the recorded intensity of the particle image pattern superimposed on a variety of noise sources. The signal-to-noise-ratio (SNR) strength governs the resulting PIV cross correlation and ultimately the accuracy and uncertainty of the resulting PIV measurement. Hence we posit that correlation SNR metrics calculated from the correlation plane can be used to quantify the quality of the correlation and the resulting uncertainty of an individual measurement. In this paper we extend the original work by Charonko and Vlachos and present a framework for evaluating the correlation SNR using a set of different metrics, which in turn are used to develop models for uncertainty estimation. Several corrections have been applied in this work. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations by applying a subtraction of the minimum correlation value to remove the effect of the background image noise. In addition, the notion of a ‘valid’ measurement is redefined with respect to the correlation peak width in order to be consistent with uncertainty quantification principles and distinct from an ‘outlier’ measurement. Finally the type and significance of the error distribution function is investigated. These advancements lead to more robust and reliable uncertainty estimation models compared with the original work by Charonko and Vlachos. The models are tested against both synthetic benchmark data as well as experimental measurements. In this work, U 68.5 uncertainties are estimated at the 68.5% confidence level while U 95 uncertainties are estimated at 95% confidence level. For all cases the resulting calculated coverage factors approximate the expected theoretical confidence intervals, thus demonstrating the applicability of these new models for estimation of uncertainty for individual PIV measurements. (paper)
Particle image velocimetry correlation signal-to-noise ratio metrics and measurement uncertainty quantification

Science.gov (United States)

Xue, Zhenyu; Charonko, John J.; Vlachos, Pavlos P.

2014-11-01

In particle image velocimetry (PIV) the measurement signal is contained in the recorded intensity of the particle image pattern superimposed on a variety of noise sources. The signal-to-noise-ratio (SNR) strength governs the resulting PIV cross correlation and ultimately the accuracy and uncertainty of the resulting PIV measurement. Hence we posit that correlation SNR metrics calculated from the correlation plane can be used to quantify the quality of the correlation and the resulting uncertainty of an individual measurement. In this paper we extend the original work by Charonko and Vlachos and present a framework for evaluating the correlation SNR using a set of different metrics, which in turn are used to develop models for uncertainty estimation. Several corrections have been applied in this work. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations by applying a subtraction of the minimum correlation value to remove the effect of the background image noise. In addition, the notion of a ‘valid’ measurement is redefined with respect to the correlation peak width in order to be consistent with uncertainty quantification principles and distinct from an ‘outlier’ measurement. Finally the type and significance of the error distribution function is investigated. These advancements lead to more robust and reliable uncertainty estimation models compared with the original work by Charonko and Vlachos. The models are tested against both synthetic benchmark data as well as experimental measurements. In this work, {{U}68.5} uncertainties are estimated at the 68.5% confidence level while {{U}95} uncertainties are estimated at 95% confidence level. For all cases the resulting calculated coverage factors approximate the expected theoretical confidence intervals, thus demonstrating the applicability of these new models for estimation of uncertainty for individual PIV measurements.
Spin correlation in t anti t production from p anti p collisions at √s = 1.8 TeV

International Nuclear Information System (INIS)

Suyong Choi

2000-01-01

The Standard Model predicts that the lifetime of the top quark is shorter than the typical time scale at which hadronization process occurs, and the spin information at its production is preserved. Spin correlation of the t anti t system from p anti p collisions at the Tevatron is analyzed using 6 events in the dilepton channels collected using the D0 detector. Spin correlation factor of κ > minus 0.25 at 68% CL is obtained from the data
A new method for quantifying the performance of EEG blind source separation algorithms by referencing a simultaneously recorded ECoG signal.

Science.gov (United States)

Oosugi, Naoya; Kitajo, Keiichi; Hasegawa, Naomi; Nagasaka, Yasuo; Okanoya, Kazuo; Fujii, Naotaka

2017-09-01

Blind source separation (BSS) algorithms extract neural signals from electroencephalography (EEG) data. However, it is difficult to quantify source separation performance because there is no criterion to dissociate neural signals and noise in EEG signals. This study develops a method for evaluating BSS performance. The idea is neural signals in EEG can be estimated by comparison with simultaneously measured electrocorticography (ECoG). Because the ECoG electrodes cover the majority of the lateral cortical surface and should capture most of the original neural sources in the EEG signals. We measured real EEG and ECoG data and developed an algorithm for evaluating BSS performance. First, EEG signals are separated into EEG components using the BSS algorithm. Second, the EEG components are ranked using the correlation coefficients of the ECoG regression and the components are grouped into subsets based on their ranks. Third, canonical correlation analysis estimates how much information is shared between the subsets of the EEG components and the ECoG signals. We used our algorithm to compare the performance of BSS algorithms (PCA, AMUSE, SOBI, JADE, fastICA) via the EEG and ECoG data of anesthetized nonhuman primates. The results (Best case >JADE = fastICA >AMUSE = SOBI ≥ PCA >random separation) were common to the two subjects. To encourage the further development of better BSS algorithms, our EEG and ECoG data are available on our Web site (http://neurotycho.org/) as a common testing platform. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Correlation of anti C1Q antibodies with disease activity in patients with systemic lupus erythematosus

International Nuclear Information System (INIS)

Riaz, M.O.; Ahmed, T.A.

2016-01-01

Objective: To study the correlation of anti C1q antibodies with disease activity in patients with systemic lupus erythematosus (SLE). Study Design: Cross sectional, observational study. Place and Duration of study: The Department of Immunology, Armed Forces Institute of Pathology, Rawalpindi in collaboration with Military Hospital, Rawalpindi, Pakistan Institute of Medical Sciences, Islamabad and Benazir Bhutto Hospital, Rawalpindi, from Jan 2012 to Dec 2013. Material and Methods: Patients with a clinical diagnosis of SLE were included in the study on fulfilling revised American College of Rheumatology (ACR) criteria (1997). Main outcome measures were SLE disease activity index (SLEDAI) score and anti C1q antibody levels in serum. SLEDAI scores were calculated for each patient on the basis of physical examination, patient interviews and previous clinical records. Anti C1q antibody levels in the serum were determined by enzyme-linked immunosorbent assay (ELISA) and correlated with the SLEDAI scores by calculating Pearson's correlation coefficient 'r'. The cutoff value for anti C1q antibody positivity in the serum was determined by evaluating the serum levels of anti C1q antibodies in 25 healthy subjects and was 12 U/ml. Results: Six male and forty nine female SLE patients with an age range of 16-47 years (mean 34.5 years) and 8-70 years (mean 31.7 years) respectively were studied. The correlation between anti C1q levels and SLEDAI scores in all patients was demonstrated by calculating the correlation coefficient and was not significant (r=0.19, p=0.14). However, there was an inverse correlation between anti C1q levels and SLEDAI scores in patients with severe disease and this was statistically significant (r=-0.448, p=0.037). The difference in anti C1q antibody positivity between patients with and without nephritis was not significant. The anti C1q antibody levels correlated poorly with anti double stranded deoxyribonucleic acid (dsDNA) antibody positivity. A
Influence of type I IFN signaling on anti-MOG antibody-mediated demyelination

DEFF Research Database (Denmark)

Berg, Carsten Tue; Khorooshi, Reza M. H.; Asgari, Nasrin

2017-01-01

Background Antibodies with specificity for myelin oligodendrocyte glycoprotein (MOG) are implicated in multiple sclerosis and related diseases. The pathogenic importance of anti-MOG antibody in primary demyelinating pathology remains poorly characterized. Objective The objective of this study...... is to investigate whether administration of anti-MOG antibody would be sufficient for demyelination and to determine if type I interferon (IFN) signaling plays a similar role in anti-MOG antibody-mediated pathology, as has been shown for neuromyelitis optica-like pathology. Methods Purified IgG2a monoclonal anti...... demyelination in wild-type and IFNAR1-KO mice. Conclusions Anti-MOG antibody and complement was sufficient to induce callosal demyelination, and pathology was dependent on type I IFN. Induction of EAE in IFNAR1-KO mice overcame the dependence on type I IFN for anti-MOG and complement-mediated demyelination....
Secrecy extraction from no-signaling correlations

International Nuclear Information System (INIS)

Scarani, Valerio; Gisin, Nicolas; Brunner, Nicolas; Masanes, Lluis; Pino, Sergi; Acin, Antonio

2006-01-01

Quantum cryptography shows that one can guarantee the secrecy of correlation on the sole basis of the laws of physics, that is, without limiting the computational power of the eavesdropper. The usual security proofs suppose that the authorized partners, Alice and Bob, have a perfect knowledge and control of their quantum systems and devices; for instance, they must be sure that the logical bits have been encoded in true qubits and not in higher dimensional systems. In this paper, we present an approach that circumvents this strong assumption. We define protocols, both for the case of bits and for generic d-dimensional outcomes, in which the security is guaranteed by the very structure of the Alice-Bob correlations, under the no-signaling condition. The idea is that if the correlations cannot be produced by shared randomness, then Eve has poor knowledge of Alice's and Bob's symbols. The present study assumes on the one hand that the eavesdropper Eve performs only individual attacks (this is a limitation to be removed in further work), and on the other hand that Eve can distribute any correlation compatible with the no-signaling condition (in this sense her power is greater than what quantum physics allows). Under these assumptions, we prove that the protocols defined here allow extracting secrecy from noisy correlations, when these correlations violate a Bell-type inequality by a sufficiently large amount. The region in which secrecy extraction is possible extends within the region of correlations achievable by measurements on entangled quantum states
Anti-correlation and subsector structure in financial systems

Science.gov (United States)

Jiang, X. F.; Zheng, B.

2012-02-01

With the random matrix theory, we study the spatial structure of the Chinese stock market, the American stock market and global market indices. After taking into account the signs of the components in the eigenvectors of the cross-correlation matrix, we detect the subsector structure of the financial systems. The positive and negative subsectors are anti-correlated with respect to each other in the corresponding eigenmode. The subsector structure is strong in the Chinese stock market, while somewhat weaker in the American stock market and global market indices. Characteristics of the subsector structures in different markets are revealed.

Frontal Parietal Control Network Regulates the Anti-Correlated Default and Dorsal Attention Networks

OpenAIRE

Gao, Wei; Lin, Weili

2011-01-01

Recent reports demonstrate the anti-correlated behaviors between the default and the dorsal attention (DA) networks. We aimed to investigate the roles of the frontal parietal control (FPC) network in regulating the two anti-correlated networks through three experimental conditions, including resting, continuous self-paced/attended sequential finger tapping (FT), and natural movie watching (MW), respectively. The two goal-directed tasks were chosen to engage either one of the two competing net...
Cross-Correlation-Function-Based Multipath Mitigation Method for Sine-BOC Signals

Directory of Open Access Journals (Sweden)

H. H. Chen

2012-06-01

Full Text Available Global Navigation Satellite Systems (GNSS positioning accuracy indoor and urban canyons environments are greatly affected by multipath due to distortions in its autocorrelation function. In this paper, a cross-correlation function between the received sine phased Binary Offset Carrier (sine-BOC modulation signal and the local signal is studied firstly, and a new multipath mitigation method based on cross-correlation function for sine-BOC signal is proposed. This method is implemented to create a cross-correlation function by designing the modulated symbols of the local signal. The theoretical analysis and simulation results indicate that the proposed method exhibits better multipath mitigation performance compared with the traditional Double Delta Correlator (DDC techniques, especially the medium/long delay multipath signals, and it is also convenient and flexible to implement by using only one correlator, which is the case of low-cost mass-market receivers.
Quantifying the importance of orbital over spin correlations in delta-Pu within density-functional theory

International Nuclear Information System (INIS)

Soderlind, P

2008-01-01

The electronic structure of plutonium is studied within the density-functional theory (DFT) model. Key features of the electronic structure are correctly modeled and bonding, total energy, and electron density of states are all consistent with measure data, although the prediction of magnetism is not consistent with many observations. Here we analyze the contributions to the electronic structure arising from spin polarization, orbital polarization, and spin-orbit interaction. These effects give rise to spin and orbital moments that are of nearly equal magnitude, but anti-parallel, suggesting a magnetic-moment cancellation with a zero total moment. Quantifying the spin versus orbital effects on the bonding, total energy, and electron spectra it becomes clear that the spin polarization is much less important than the orbital correlations. Consequently, a restricted DFT approach with a non-spin polarized electronic structure can produce reasonable equation-of-state and electron spectra for (delta)-Pu when the orbital effects are accounted for. Hence, we present two non-magnetic models. One in which the spin moment is canceled by the orbital moment and another in which the spin moment (and therefore the orbital moment) is restricted to zero
Spin Correlations of Lambda anti-Lambda Pairs as a Probe of Quark-Antiquark Pair Production

CERN Document Server

Ellis, John

2012-01-01

The polarizations of Lambda and anti-Lambda are thought to retain memories of the spins of their parent s quarks and antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of Lambda and anti-Lambda produced at low relative momenta may therefore be used to probe the spin states of s anti-s pairs produced during hadronization. We consider the possibilities that they are produced in a 3P_0 state, as might result from fluctuations in the magnitude of , a 1S_0 state, as might result from chiral fluctuations, or a 3S_1 or other spin state, as might result from production by a quark-antiquark or gluon pair. We provide templates for the p anti-p angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s anti-s production mechanisms in pp and heavy-ion collisions.
Correlation of pharmacodynamic activity, pharmacokinetics, and anti-product antibody responses to anti-IL-21R antibody therapeutics following IV administration to cynomolgus monkeys

Directory of Open Access Journals (Sweden)

Spaulding Vikki

2010-04-01

Full Text Available Abstract Background Anti-IL-21R antibodies are potential therapeutics for the treatment of autoimmune diseases. This study evaluated correlations between the pharmacodynamic (PD activity, pharmacokinetics, and anti-product antibody responses of human anti-IL-21R antibodies Ab-01 and Ab-02 following IV administration to cynomolgus monkeys. Methods The PD assay was based on the ability of recombinant human IL-21 (rhuIL-21 to induce expression of the IL-2RA gene in cynomolgus monkey whole blood samples ex vivo. Monkeys screened for responsiveness to rhuIL-21 stimulation using the PD assay, were given a single 10 mg/kg IV dosage of Ab-01, Ab-02, or a control antibody (3/group, and blood samples were evaluated for PD activity (inhibition of IL-2RA expression for up to 148 days. Anti-IL-21R antibody concentrations and anti-product antibody responses were measured in serum using immunoassays and flow cytometry. Results Following IV administration of Ab-01 and Ab-02 to cynomolgus monkeys, PD activity was observed as early as 5 minutes (first time point sampled. This PD activity had good correlation with the serum concentrations and anti-product antibody responses throughout the study. The mean terminal half-life (t1/2 was ~10.6 and 2.3 days for Ab-01 and Ab-02, respectively. PD activity was lost at ~5-13 weeks for Ab-01 and at ~2 weeks for Ab-02, when serum concentrations were relatively low. The estimated minimum concentrations needed to maintain PD activity were ~4-6 nM for Ab-01 and ~2.5 nM for Ab-02, and were consistent with the respective KD values for binding to human IL-21R. For Ab-01, there was noticeable inter-animal variability in t1/2 values (~6-14 days and the resulting PD profiles, which correlated with the onset of anti-product antibody formation. While all three Ab-01-dosed animals were positive for anti-Ab-01 antibodies, only one monkey (with the shortest t1/2 and the earliest loss of PD activity had evidence of neutralizing anti-Ab-01
Cognitive reserve moderates the association between functional network anti-correlations and memory in MCI.

Science.gov (United States)

Franzmeier, Nicolai; Buerger, Katharina; Teipel, Stefan; Stern, Yaakov; Dichgans, Martin; Ewers, Michael

2017-02-01

Cognitive reserve (CR) shows protective effects on cognitive function in older adults. Here, we focused on the effects of CR at the functional network level. We assessed in patients with amnestic mild cognitive impairment (aMCI) whether higher CR moderates the association between low internetwork cross-talk on memory performance. In 2 independent aMCI samples (n = 76 and 93) and healthy controls (HC, n = 36), CR was assessed via years of education and intelligence (IQ). We focused on the anti-correlation between the dorsal attention network (DAN) and an anterior and posterior default mode network (DMN), assessed via sliding time window analysis of resting-state functional magnetic resonance imaging (fMRI). The DMN-DAN anti-correlation was numerically but not significantly lower in aMCI compared to HC. However, in aMCI, lower anterior DMN-DAN anti-correlation was associated with lower memory performance. This association was moderated by CR proxies, where the association between the internetwork anti-correlation and memory performance was alleviated at higher levels of education or IQ. In conclusion, lower DAN-DMN cross-talk is associated with lower memory in aMCI, where such effects are buffered by higher CR. Copyright © 2016 Elsevier Inc. All rights reserved.
Monitoring low molecular weight heparins at therapeutic levels: dose-responses of, and correlations and differences between aPTT, anti-factor Xa and thrombin generation assays.

Directory of Open Access Journals (Sweden)

Owain Thomas

Full Text Available Low molecular weight heparins (LMWH's are used to prevent and treat thrombosis. Tests for monitoring LMWH's include anti-factor Xa (anti-FXa, activated partial thromboplastin time (aPTT and thrombin generation. Anti-FXa is the current gold standard despite LMWH's varying affinities for FXa and thrombin.To examine the effects of two different LMWH's on the results of 4 different aPTT-tests, anti-FXa activity and thrombin generation and to assess the tests' concordance.Enoxaparin and tinzaparin were added ex-vivo in concentrations of 0.0, 0.5, 1.0 and 1.5 anti-FXa international units (IU/mL, to blood from 10 volunteers. aPTT was measured using two whole blood methods (Free oscillation rheometry (FOR and Hemochron Jr (HCJ and an optical plasma method using two different reagents (ActinFSL and PTT-Automat. Anti-FXa activity was quantified using a chromogenic assay. Thrombin generation (Endogenous Thrombin Potential, ETP was measured on a Ceveron Alpha instrument using the TGA RB and more tissue-factor rich TGA RC reagents.Methods' mean aPTT at 1.0 IU/mL LMWH varied between 54s (SD 11 and 69s (SD 14 for enoxaparin and between 101s (SD 21 and 140s (SD 28 for tinzaparin. ActinFSL gave significantly shorter aPTT results. aPTT and anti-FXa generally correlated well. ETP as measured with the TGA RC reagent but not the TGA RB reagent showed an inverse exponential relationship to the concentration of LMWH. The HCJ-aPTT results had the weakest correlation to anti-FXa and thrombin generation (Rs0.62-0.87, whereas the other aPTT methods had similar correlation coefficients (Rs0.80-0.92.aPTT displays a linear dose-response to LMWH. There is variation between aPTT assays. Tinzaparin increases aPTT and decreases thrombin generation more than enoxaparin at any given level of anti-FXa activity, casting doubt on anti-FXa's present gold standard status. Thrombin generation with tissue factor-rich activator is a promising method for monitoring LMWH's.
Gating based on internal/external signals with dynamic correlation updates

International Nuclear Information System (INIS)

Wu Huanmei; Zhao Qingya; Berbeco, Ross I; Nishioka, Seiko; Shirato, Hiroki; Jiang, Steve B

2008-01-01

Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.
Gating based on internal/external signals with dynamic correlation updates

Energy Technology Data Exchange (ETDEWEB)

Wu Huanmei [Purdue School of Engineering and Technology, Indiana University School of Informatics, IUPUI, Indianapolis, IN (United States); Zhao Qingya [School of Health Sciences, Purdue University, West Lafayette, IN (United States); Berbeco, Ross I [Department of Radiation Oncology, Dana-Farber/Brigham and Womens Cancer Center and Harvard Medical School, Boston, MA (United States); Nishioka, Seiko [NTT East-Japan Sapporo Hospital, Sapporo (Japan); Shirato, Hiroki [Hokkaido University Graduate School of Medicine, Sapporo (Japan); Jiang, Steve B [Department of Radiation Oncology, School of Medicine, University of California, San Diego, CA (United States)], E-mail: hw9@iupui.edu, E-mail: sbjiang@ucsd.edu

2008-12-21

Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.
Quantifying the nonlocality of Greenberger-Horne-Zeilinger quantum correlations by a bounded communication simulation protocol.

Science.gov (United States)

Branciard, Cyril; Gisin, Nicolas

2011-07-08

The simulation of quantum correlations with finite nonlocal resources, such as classical communication, gives a natural way to quantify their nonlocality. While multipartite nonlocal correlations appear to be useful resources, very little is known on how to simulate multipartite quantum correlations. We present a protocol that reproduces tripartite Greenberger-Horne-Zeilinger correlations with bounded communication: 3 bits in total turn out to be sufficient to simulate all equatorial Von Neumann measurements on the tripartite Greenberger-Horne-Zeilinger state.
Spin correlations of Λanti Λ pairs as a probe of quark-antiquark pair production

International Nuclear Information System (INIS)

Ellis, John; Hwang, Dae Sung

2012-01-01

The polarizations of Λ and anti Λ are thought to retain memories of the spins of their parent s quarks and anti s antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of Λ and anti Λ produced at low relative momenta may therefore be used to probe the spin states of s anti s pairs produced during hadronization. We consider the possibilities that they are produced in a 3 P 0 state, as might result from fluctuations in the magnitude of left angle anti ss right angle, a 1 S 0 state, as might result from chiral fluctuations, or a 3 S 1 or other spin state, as might result from production by a quark-antiquark or gluon pair. We provide templates for the p anti p angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s anti s production mechanisms in pp and heavy-ion collisions. (orig.)
Spin correlations of {lambda}anti {lambda} pairs as a probe of quark-antiquark pair production

Energy Technology Data Exchange (ETDEWEB)

Ellis, John [King' s College London, Theoretical Particle Physics and Cosmology Group, Physics Department, London (United Kingdom); CERN, Theory Division, Physics Department, Geneva 23 (Switzerland); Hwang, Dae Sung [Sejong University, Department of Physics, Seoul (Korea, Republic of)

2012-02-15

The polarizations of {lambda} and anti {lambda} are thought to retain memories of the spins of their parent s quarks and anti s antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of {lambda} and anti {lambda} produced at low relative momenta may therefore be used to probe the spin states of s anti s pairs produced during hadronization. We consider the possibilities that they are produced in a {sup 3}P{sub 0} state, as might result from fluctuations in the magnitude of left angle anti ss right angle, a {sup 1}S{sub 0} state, as might result from chiral fluctuations, or a {sup 3}S{sub 1} or other spin state, as might result from production by a quark-antiquark or gluon pair. We provide templates for the p anti p angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s anti s production mechanisms in pp and heavy-ion collisions. (orig.)
Ultrasonic Detection Using Correlation Images (Preprint)

National Research Council Canada - National Science Library

Cepel, Raini; Ho, K. C; Rinker, Brett A; Palmer, Donald D; Neal, Steven P

2006-01-01

.... In this paper, we describe an amplitude independent approach for imaging and detection based on the similarity of adjacent signals, quantified by the correlation coefficient calculated between A-scans...
Geographic and demographic correlates of autism-related anti-vaccine beliefs on Twitter, 2009-15.

Science.gov (United States)

Tomeny, Theodore S; Vargo, Christopher J; El-Toukhy, Sherine

2017-10-01

This study examines temporal trends, geographic distribution, and demographic correlates of anti-vaccine beliefs on Twitter, 2009-2015. A total of 549,972 tweets were downloaded and coded for the presence of anti-vaccine beliefs through a machine learning algorithm. Tweets with self-disclosed geographic information were resolved and United States Census data were collected for corresponding areas at the micropolitan/metropolitan level. Trends in number of anti-vaccine tweets were examined at the national and state levels over time. A least absolute shrinkage and selection operator regression model was used to determine census variables that were correlated with anti-vaccination tweet volume. Fifty percent of our sample of 549,972 tweets collected between 2009 and 2015 contained anti-vaccine beliefs. Anti-vaccine tweet volume increased after vaccine-related news coverage. California, Connecticut, Massachusetts, New York, and Pennsylvania had anti-vaccination tweet volume that deviated from the national average. Demographic characteristics explained 67% of variance in geographic clustering of anti-vaccine tweets, which were associated with a larger population and higher concentrations of women who recently gave birth, households with high income levels, men aged 40 to 44, and men with minimal college education. Monitoring anti-vaccination beliefs on Twitter can uncover vaccine-related concerns and misconceptions, serve as an indicator of shifts in public opinion, and equip pediatricians to refute anti-vaccine arguments. Real-time interventions are needed to counter anti-vaccination beliefs online. Identifying clusters of anti-vaccination beliefs can help public health professionals disseminate targeted/tailored interventions to geographic locations and demographic sectors of the population. Copyright © 2017 Elsevier Ltd. All rights reserved.
Whistler-mode signals: Group delay by cross correlation

International Nuclear Information System (INIS)

Thomson, N.R.

1975-01-01

Group travel times of 18.6 kHz whistler-mode signals from NLK, Seattle, to Wellington, New Zealand, are now being measured using the normal FSK transmissions. This is done using a mini-computer programmed to perform real-time cross correlations between two receivers: one receiver gets its signal from a whip aerial on which the ground wave (subionospheric mode) dominates, while the other gets its signal from a loop oriented for minimum ground wave. Group travel time can thus be measured continuously while there are whistler-mode signals present. Delays of 0.2--0.8 seconds have been found
Anti-signal recognition particle autoantibody ELISA validation and clinical associations.

Science.gov (United States)

Aggarwal, Rohit; Oddis, Chester V; Goudeau, Danielle; Fertig, Noreen; Metes, Ilinca; Stephens, Chad; Qi, Zengbiao; Koontz, Diane; Levesque, Marc C

2015-07-01

The aim of this study was to develop and validate a quantitative anti-signal recognition particle (SRP) autoantibody serum ELISA in patients with myositis and longitudinal association with myositis disease activity. We developed a serum ELISA using recombinant purified full-length human SRP coated on ELISA plates and a secondary antibody that bound human IgG to detect anti-SRP binding. Protein immunoprecipitation was used as the gold standard for the presence of anti-SRP. Serum samples from three groups were analysed: SRP(+) myositis subjects by immunoprecipitation, SRP(-) myositis subjects by immunoprecipitation and non-myositis controls. The ELISA's sensitivity, specificity, positive predictive value and negative predictive value were evaluated. Percentage agreement and test-retest reliability were assessed. Serial samples from seven SRP immunoprecipitation-positive subjects were also tested, along with serum muscle enzymes and manual muscle testing. Using immunoprecipitation, we identified 26 SRP(+) myositis patients and 77 SRP(-) controls (including 38 patients with necrotizing myopathy). Non-myositis control patients included SLE (n = 4) and SSc (n = 7) patients. Anti-SRP positivity by ELISA showed strong agreement (97.1%) with immunoprecipitation (κ = 0.94). The sensitivity, specificity, positive predictive value, and negative predictive value of the anti-SRP ELISA were 88, 100, 100 and 96, respectively. The area under the curve was 0.94, and test-retest reliability was strong (r = 0.91, P < 0.001). Serial samples showed that anti-SRP levels paralleled changes in muscle enzymes and manual muscle testing. We developed a quantitative ELISA for detecting serum anti-SRP autoantibodies and validated the assay in myositis. Longitudinal assessment of SRP levels by ELISA may be a useful biomarker for disease activity. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions
Correlation analysis of respiratory signals by using parallel coordinate plots.

Science.gov (United States)

Saatci, Esra

2018-01-01

The understanding of the bonds and the relationships between the respiratory signals, i.e. the airflow, the mouth pressure, the relative temperature and the relative humidity during breathing may provide the improvement on the measurement methods of respiratory mechanics and sensor designs or the exploration of the several possible applications in the analysis of respiratory disorders. Therefore, the main objective of this study was to propose a new combination of methods in order to determine the relationship between respiratory signals as a multidimensional data. In order to reveal the coupling between the processes two very different methods were used: the well-known statistical correlation analysis (i.e. Pearson's correlation and cross-correlation coefficient) and parallel coordinate plots (PCPs). Curve bundling with the number intersections for the correlation analysis, Least Mean Square Time Delay Estimator (LMS-TDE) for the point delay detection and visual metrics for the recognition of the visual structures were proposed and utilized in PCP. The number of intersections was increased when the correlation coefficient changed from high positive to high negative correlation between the respiratory signals, especially if whole breath was processed. LMS-TDE coefficients plotted in PCP indicated well-matched point delay results to the findings in the correlation analysis. Visual inspection of PCB by visual metrics showed range, dispersions, entropy comparisons and linear and sinusoidal-like relationships between the respiratory signals. It is demonstrated that the basic correlation analysis together with the parallel coordinate plots perceptually motivates the visual metrics in the display and thus can be considered as an aid to the user analysis by providing meaningful views of the data. Copyright © 2017 Elsevier B.V. All rights reserved.
Adaptive endpoint detection of seismic signal based on auto-correlated function

International Nuclear Information System (INIS)

Fan Wanchun; Shi Ren

2001-01-01

Based on the analysis of auto-correlation function, the notion of the distance between auto-correlation function was quoted, and the characterization of the noise and the signal with noise were discussed by using the distance. Then, the method of auto- adaptable endpoint detection of seismic signal based on auto-correlated similarity was summed up. The steps of implementation and determining of the thresholds were presented in detail. The experimental results that were compared with the methods based on artificial detecting show that this method has higher sensitivity even in a low signal with noise ratio circumstance
Proton-proton, anti-proton-anti-proton, proton-anti-proton correlations in Au+Au collisions measured by STAR at RHIC

International Nuclear Information System (INIS)

Gos, H.P.

2007-01-01

The analysis of two-particle correlations provides a powerful tool to study the properties of hot and dense matter created in heavy-ion collisions at ultra-relativistic energies. Applied to identical and non-identical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced from identical pion studies, providing complete information about the source characteristics. In this paper we present the correlation functions obtained for identical and non-identical baryon pairs of protons and anti-protons. The data were collected recently in Au+Au collisions at √(s NN )=62 GeV and √(s NN )=200 GeV by the STAR detector at the RHIC accelerator. We introduce corrections to the baryon-baryon correlations taking into account: residual correlations from weak decays, particle identification probability and the fraction of primary baryons. Finally we compare our results to theoretical predictions. (orig.)
Hedgehog Signals Mediate Anti-Cancer Drug Resistance in Three-Dimensional Primary Colorectal Cancer Organoid Culture

Directory of Open Access Journals (Sweden)

Tatsuya Usui

2018-04-01

Full Text Available Colorectal cancer is one of the most common causes of cancer death worldwide. In patients with metastatic colorectal cancer, combination treatment with several anti-cancer drugs is employed and improves overall survival in some patients. Nevertheless, most patients with metastatic disease are not cured owing to the drug resistance. Cancer stem cells are known to regulate resistance to chemotherapy. In the previous study, we established a novel three-dimensional organoid culture model from tumor colorectal tissues of human patients using an air–liquid interface (ALI method, which contained numerous cancer stem cells and showed resistance to 5-fluorouracil (5-FU and Irinotecan. Here, we investigate which inhibitor for stem cell-related signal improves the sensitivity for anti-cancer drug treatment in tumor ALI organoids. Treatment with Hedgehog signal inhibitors (AY9944, GANT61 decreases the cell viability of organoids compared with Notch (YO-01027, DAPT and Wnt (WAV939, Wnt-C59 signal inhibitors. Combination treatment of AY9944 or GANT61 with 5-FU, Irinotecan or Oxaliplatin decreases the cell viability of tumor organoids compared with each anti-cancer drug alone treatment. Treatment with AY9944 or GANT61 inhibits expression of stem cell markers c-Myc, CD44 and Nanog, likely through the decrease of their transcription factor, GLI-1 expression. Combination treatment of AY9944 or GANT61 with 5-FU or Irinotecan also prevents colony formation of colorectal cancer cell lines HCT116 and SW480. These findings suggest that Hedgehog signals mediate anti-cancer drug resistance in colorectal tumor patient-derived ALI organoids and that the inhibitors are useful as a combinational therapeutic strategy against colorectal cancer.

Compressed Sensing with Linear Correlation Between Signal and Measurement Noise

DEFF Research Database (Denmark)

Arildsen, Thomas; Larsen, Torben

2014-01-01

reconstruction algorithms, but is not known in existing literature. The proposed technique reduces reconstruction error considerably in the case of linearly correlated measurements and noise. Numerical experiments confirm the efficacy of the technique. The technique is demonstrated with application to low......Existing convex relaxation-based approaches to reconstruction in compressed sensing assume that noise in the measurements is independent of the signal of interest. We consider the case of noise being linearly correlated with the signal and introduce a simple technique for improving compressed...... sensing reconstruction from such measurements. The technique is based on a linear model of the correlation of additive noise with the signal. The modification of the reconstruction algorithm based on this model is very simple and has negligible additional computational cost compared to standard...
Evasion of anti-growth signaling: a key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds

Science.gov (United States)

Amin, A.R.M. Ruhul; Karpowicz, Phillip A.; Carey, Thomas E.; Arbiser, Jack; Nahta, Rita; Chen, Zhuo G.; Dong, Jin-Tang; Kucuk, Omer; Khan, Gazala N.; Huang, Gloria S.; Mi, Shijun; Lee, Ho-Young; Reichrath, Joerg; Honoki, Kanya; Georgakilas, Alexandros G.; Amedei, Amedeo; Amin, Amr; Helferich, Bill; Boosani, Chandra S.; Ciriolo, Maria Rosa; Chen, Sophie; Mohammed, Sulma I.; Azmi, Asfar S.; Keith, W Nicol; Bhakta, Dipita; Halicka, Dorota; Niccolai, Elena; Fujii, Hiromasa; Aquilano, Katia; Ashraf, S. Salman; Nowsheen, Somaira; Yang, Xujuan; Bilsland, Alan; Shin, Dong M.

2015-01-01

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally-occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally-occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting. PMID:25749195
Multifractal temporally weighted detrended cross-correlation analysis to quantify power-law cross-correlation and its application to stock markets

Science.gov (United States)

Wei, Yun-Lan; Yu, Zu-Guo; Zou, Hai-Long; Anh, Vo

2017-06-01

A new method—multifractal temporally weighted detrended cross-correlation analysis (MF-TWXDFA)—is proposed to investigate multifractal cross-correlations in this paper. This new method is based on multifractal temporally weighted detrended fluctuation analysis and multifractal cross-correlation analysis (MFCCA). An innovation of the method is applying geographically weighted regression to estimate local trends in the nonstationary time series. We also take into consideration the sign of the fluctuations in computing the corresponding detrended cross-covariance function. To test the performance of the MF-TWXDFA algorithm, we apply it and the MFCCA method on simulated and actual series. Numerical tests on artificially simulated series demonstrate that our method can accurately detect long-range cross-correlations for two simultaneously recorded series. To further show the utility of MF-TWXDFA, we apply it on time series from stock markets and find that power-law cross-correlation between stock returns is significantly multifractal. A new coefficient, MF-TWXDFA cross-correlation coefficient, is also defined to quantify the levels of cross-correlation between two time series.
Understanding the amplitudes of noise correlation measurements

Science.gov (United States)

Tsai, Victor C.

2011-01-01

Cross correlation of ambient seismic noise is known to result in time series from which station-station travel-time measurements can be made. Part of the reason that these cross-correlation travel-time measurements are reliable is that there exists a theoretical framework that quantifies how these travel times depend on the features of the ambient noise. However, corresponding theoretical results do not currently exist to describe how the amplitudes of the cross correlation depend on such features. For example, currently it is not possible to take a given distribution of noise sources and calculate the cross correlation amplitudes one would expect from such a distribution. Here, we provide a ray-theoretical framework for calculating cross correlations. This framework differs from previous work in that it explicitly accounts for attenuation as well as the spatial distribution of sources and therefore can address the issue of quantifying amplitudes in noise correlation measurements. After introducing the general framework, we apply it to two specific problems. First, we show that we can quantify the amplitudes of coherency measurements, and find that the decay of coherency with station-station spacing depends crucially on the distribution of noise sources. We suggest that researchers interested in performing attenuation measurements from noise coherency should first determine how the dominant sources of noise are distributed. Second, we show that we can quantify the signal-to-noise ratio of noise correlations more precisely than previous work, and that these signal-to-noise ratios can be estimated for given situations prior to the deployment of seismometers. It is expected that there are applications of the theoretical framework beyond the two specific cases considered, but these applications await future work.
Depth perception not found in human observers for static or dynamic anti-correlated random dot stereograms.

Directory of Open Access Journals (Sweden)

Paul B Hibbard

Full Text Available One of the greatest challenges in visual neuroscience is that of linking neural activity with perceptual experience. In the case of binocular depth perception, important insights have been achieved through comparing neural responses and the perception of depth, for carefully selected stimuli. One of the most important types of stimulus that has been used here is the anti-correlated random dot stereogram (ACRDS. In these stimuli, the contrast polarity of one half of a stereoscopic image is reversed. While neurons in cortical area V1 respond reliably to the binocular disparities in ACRDS, they do not create a sensation of depth. This discrepancy has been used to argue that depth perception must rely on neural activity elsewhere in the brain. Currently, the psychophysical results on which this argument rests are not clear-cut. While it is generally assumed that ACRDS do not support the perception of depth, some studies have reported that some people, some of the time, perceive depth in some types of these stimuli. Given the importance of these results for understanding the neural correlates of stereopsis, we studied depth perception in ACRDS using a large number of observers, in order to provide an unambiguous conclusion about the extent to which these stimuli support the perception of depth. We presented observers with random dot stereograms in which correlated dots were presented in a surrounding annulus and correlated or anti-correlated dots were presented in a central circular region. While observers could reliably report the depth of the central region for correlated stimuli, we found no evidence for depth perception in static or dynamic anti-correlated stimuli. Confidence ratings for stereoscopic perception were uniformly low for anti-correlated stimuli, but showed normal variation with disparity for correlated stimuli. These results establish that the inability of observers to perceive depth in ACRDS is a robust phenomenon.
Depth perception not found in human observers for static or dynamic anti-correlated random dot stereograms.

Science.gov (United States)

Hibbard, Paul B; Scott-Brown, Kenneth C; Haigh, Emma C; Adrain, Melanie

2014-01-01

One of the greatest challenges in visual neuroscience is that of linking neural activity with perceptual experience. In the case of binocular depth perception, important insights have been achieved through comparing neural responses and the perception of depth, for carefully selected stimuli. One of the most important types of stimulus that has been used here is the anti-correlated random dot stereogram (ACRDS). In these stimuli, the contrast polarity of one half of a stereoscopic image is reversed. While neurons in cortical area V1 respond reliably to the binocular disparities in ACRDS, they do not create a sensation of depth. This discrepancy has been used to argue that depth perception must rely on neural activity elsewhere in the brain. Currently, the psychophysical results on which this argument rests are not clear-cut. While it is generally assumed that ACRDS do not support the perception of depth, some studies have reported that some people, some of the time, perceive depth in some types of these stimuli. Given the importance of these results for understanding the neural correlates of stereopsis, we studied depth perception in ACRDS using a large number of observers, in order to provide an unambiguous conclusion about the extent to which these stimuli support the perception of depth. We presented observers with random dot stereograms in which correlated dots were presented in a surrounding annulus and correlated or anti-correlated dots were presented in a central circular region. While observers could reliably report the depth of the central region for correlated stimuli, we found no evidence for depth perception in static or dynamic anti-correlated stimuli. Confidence ratings for stereoscopic perception were uniformly low for anti-correlated stimuli, but showed normal variation with disparity for correlated stimuli. These results establish that the inability of observers to perceive depth in ACRDS is a robust phenomenon.
Characterizing scaling properties of complex signals with missed data segments using the multifractal analysis

Science.gov (United States)

Pavlov, A. N.; Pavlova, O. N.; Abdurashitov, A. S.; Sindeeva, O. A.; Semyachkina-Glushkovskaya, O. V.; Kurths, J.

2018-01-01

The scaling properties of complex processes may be highly influenced by the presence of various artifacts in experimental recordings. Their removal produces changes in the singularity spectra and the Hölder exponents as compared with the original artifacts-free data, and these changes are significantly different for positively correlated and anti-correlated signals. While signals with power-law correlations are nearly insensitive to the loss of significant parts of data, the removal of fragments of anti-correlated signals is more crucial for further data analysis. In this work, we study the ability of characterizing scaling features of chaotic and stochastic processes with distinct correlation properties using a wavelet-based multifractal analysis, and discuss differences between the effect of missed data for synchronous and asynchronous oscillatory regimes. We show that even an extreme data loss allows characterizing physiological processes such as the cerebral blood flow dynamics.
Anti-correlated Soft Lags in the Intermediate State of Black Hole Source GX 339-4

OpenAIRE

Sriram, K.; Rao, A. R.; Choi, C. S.

2010-01-01

We report the few hundred second anti-correlated soft lags between soft and hard energy bands in the source GX 339-4 using RXTE observations. In one observation, anti-correlated soft lags were observed using the ISGRI/INTEGRAL hard energy band and the PCA/RXTE soft energy band light curves. The lags were observed when the source was in hard and soft intermediate states, i.e., in a steep power-law state.We found that the temporal and spectral properties were changed during the lag timescale. T...
Quantum Zeno and anti-Zeno effects on quantum and classical correlations

International Nuclear Information System (INIS)

Francica, F.; Plastina, F.; Maniscalco, S.

2010-01-01

In this paper we study the possibility of modifying the dynamics of both quantum correlations, such as entanglement and discord, and classical correlations of an open bipartite system by means of the quantum Zeno effect. We consider two qubits coupled to a common boson reservoir at zero temperature. This model describes, for example, two atoms interacting with a quantized mode of a lossy cavity. We show that when the frequencies of the two atoms are symmetrically detuned from that of the cavity mode, oscillations between the Zeno and anti-Zeno regimes occur. We also calculate analytically the time evolution of both classical correlations and quantum discord, and we compare the Zeno dynamics of entanglement with the Zeno dynamics of classical correlations and discord.
Altered Global Signal Topography in Schizophrenia.

Science.gov (United States)

Yang, Genevieve J; Murray, John D; Glasser, Matthew; Pearlson, Godfrey D; Krystal, John H; Schleifer, Charlie; Repovs, Grega; Anticevic, Alan

2017-11-01

Schizophrenia (SCZ) is a disabling neuropsychiatric disease associated with disruptions across distributed neural systems. Resting-state functional magnetic resonance imaging has identified extensive abnormalities in the blood-oxygen level-dependent signal in SCZ patients, including alterations in the average signal over the brain-i.e. the "global" signal (GS). It remains unknown, however, if these "global" alterations occur pervasively or follow a spatially preferential pattern. This study presents the first network-by-network quantification of GS topography in healthy subjects and SCZ patients. We observed a nonuniform GS contribution in healthy comparison subjects, whereby sensory areas exhibited the largest GS component. In SCZ patients, we identified preferential GS representation increases across association regions, while sensory regions showed preferential reductions. GS representation in sensory versus association cortices was strongly anti-correlated in healthy subjects. This anti-correlated relationship was markedly reduced in SCZ. Such shifts in GS topography may underlie profound alterations in neural information flow in SCZ, informing development of pharmacotherapies. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Sound card based digital correlation detection of weak photoelectrical signals

International Nuclear Information System (INIS)

Tang Guanghui; Wang Jiangcheng

2005-01-01

A simple and low-cost digital correlation method is proposed to investigate weak photoelectrical signals, using a high-speed photodiode as detector, which is directly connected to a programmably triggered sound card analogue-to-digital converter and a personal computer. Two testing experiments, autocorrelation detection of weak flickering signals from a computer monitor under background of noisy outdoor stray light and cross-correlation measurement of the surface velocity of a motional tape, are performed, showing that the results are reliable and the method is easy to implement
Correlator of fundamental and anti-symmetric Wilson loops in AdS/CFT correspondence

International Nuclear Information System (INIS)

Tai, T.-S.; Yamaguchi, Satoshi

2007-01-01

We study the two circular Wilson loop correlator in which one is of anti-symmetric representation, while the other is of fundamental representation in 4-dimensional N = 4 super Yang-Mills theory. This correlator has a good AdS dual, which is a system of a D5-brane and a fundamental string. We calculated the on-shell action of the string, and clarified the Gross-Ooguri transition in this correlator. Some limiting cases are also examined
Strange particle correlations measured by the Star experiment in ultra-relativistic heavy ion collisions a RHIC; Etude des correlations de particules etranges mesurees par l'experience STAR dans les collisions d'ions lourds ultra-relativistes au RHIC

Energy Technology Data Exchange (ETDEWEB)

Renault, G

2004-09-01

Non-identical correlation functions allow to study the space-time evolution of the source of particles formed in ultra-relativistic heavy ion collisions. The STAR experiment is dedicated to probe the formation of a new state of nuclear matter called Quark Gluon Plasma. The proton - lambda correlation function is supposed to be more sensitive to bigger source sizes than the proton - proton because of the absence of the final state Coulomb interaction. In this thesis, proton - lambda, anti-proton - anti-lambda, anti-proton - lambda and proton - anti-lambda correlation functions are studied in Au+Au collisions at {radical}S{sub NN} = 200 GeV using an analytical model. The proton - lambda and anti-proton - anti-lambda correlation functions exhibit the same behavior as in previous measurements. The anti-proton - lambda and proton - anti-lambda correlation functions, measured for the first time, show a very strong signal corresponding to the baryon - anti-baryon annihilation channel. Parameterizing the correlation functions has allowed to characterize final state interactions. (author)
Total focusing method with correlation processing of antenna array signals

Science.gov (United States)

Kozhemyak, O. A.; Bortalevich, S. I.; Loginov, E. L.; Shinyakov, Y. A.; Sukhorukov, M. P.

2018-03-01

The article proposes a method of preliminary correlation processing of a complete set of antenna array signals used in the image reconstruction algorithm. The results of experimental studies of 3D reconstruction of various reflectors using and without correlation processing are presented in the article. Software ‘IDealSystem3D’ by IDeal-Technologies was used for experiments. Copper wires of different diameters located in a water bath were used as a reflector. The use of correlation processing makes it possible to obtain more accurate reconstruction of the image of the reflectors and to increase the signal-to-noise ratio. The experimental results were processed using an original program. This program allows varying the parameters of the antenna array and sampling frequency.
Correlated statistical uncertainties in coded-aperture imaging

International Nuclear Information System (INIS)

Fleenor, Matthew C.; Blackston, Matthew A.; Ziock, Klaus P.

2015-01-01

In nuclear security applications, coded-aperture imagers can provide a wealth of information regarding the attributes of both the radioactive and nonradioactive components of the objects being imaged. However, for optimum benefit to the community, spatial attributes need to be determined in a quantitative and statistically meaningful manner. To address a deficiency of quantifiable errors in coded-aperture imaging, we present uncertainty matrices containing covariance terms between image pixels for MURA mask patterns. We calculated these correlated uncertainties as functions of variation in mask rank, mask pattern over-sampling, and whether or not anti-mask data are included. Utilizing simulated point source data, we found that correlations arose when two or more image pixels were summed. Furthermore, we found that the presence of correlations was heightened by the process of over-sampling, while correlations were suppressed by the inclusion of anti-mask data and with increased mask rank. As an application of this result, we explored how statistics-based alarming is impacted in a radiological search scenario
R-2HG Exhibits Anti-tumor Activity by Targeting FTO/m6A/MYC/CEBPA Signaling.

Science.gov (United States)

Su, Rui; Dong, Lei; Li, Chenying; Nachtergaele, Sigrid; Wunderlich, Mark; Qing, Ying; Deng, Xiaolan; Wang, Yungui; Weng, Xiaocheng; Hu, Chao; Yu, Mengxia; Skibbe, Jennifer; Dai, Qing; Zou, Dongling; Wu, Tong; Yu, Kangkang; Weng, Hengyou; Huang, Huilin; Ferchen, Kyle; Qin, Xi; Zhang, Bin; Qi, Jun; Sasaki, Atsuo T; Plas, David R; Bradner, James E; Wei, Minjie; Marcucci, Guido; Jiang, Xi; Mulloy, James C; Jin, Jie; He, Chuan; Chen, Jianjun

2018-01-11

R-2-hydroxyglutarate (R-2HG), produced at high levels by mutant isocitrate dehydrogenase 1/2 (IDH1/2) enzymes, was reported as an oncometabolite. We show here that R-2HG also exerts a broad anti-leukemic activity in vitro and in vivo by inhibiting leukemia cell proliferation/viability and by promoting cell-cycle arrest and apoptosis. Mechanistically, R-2HG inhibits fat mass and obesity-associated protein (FTO) activity, thereby increasing global N 6 -methyladenosine (m 6 A) RNA modification in R-2HG-sensitive leukemia cells, which in turn decreases the stability of MYC/CEBPA transcripts, leading to the suppression of relevant pathways. Ectopically expressed mutant IDH1 and S-2HG recapitulate the effects of R-2HG. High levels of FTO sensitize leukemic cells to R-2HG, whereas hyperactivation of MYC signaling confers resistance that can be reversed by the inhibition of MYC signaling. R-2HG also displays anti-tumor activity in glioma. Collectively, while R-2HG accumulated in IDH1/2 mutant cancers contributes to cancer initiation, our work demonstrates anti-tumor effects of 2HG in inhibiting proliferation/survival of FTO-high cancer cells via targeting FTO/m 6 A/MYC/CEBPA signaling. Copyright © 2017 Elsevier Inc. All rights reserved.
Discriminative analysis of early Alzheimer's disease based on two intrinsically anti-correlated networks with resting-state fMRI.

Science.gov (United States)

Wang, Kun; Jiang, Tianzi; Liang, Meng; Wang, Liang; Tian, Lixia; Zhang, Xinqing; Li, Kuncheng; Liu, Zhening

2006-01-01

In this work, we proposed a discriminative model of Alzheimer's disease (AD) on the basis of multivariate pattern classification and functional magnetic resonance imaging (fMRI). This model used the correlation/anti-correlation coefficients of two intrinsically anti-correlated networks in resting brains, which have been suggested by two recent studies, as the feature of classification. Pseudo-Fisher Linear Discriminative Analysis (pFLDA) was then performed on the feature space and a linear classifier was generated. Using leave-one-out (LOO) cross validation, our results showed a correct classification rate of 83%. We also compared the proposed model with another one based on the whole brain functional connectivity. Our proposed model outperformed the other one significantly, and this implied that the two intrinsically anti-correlated networks may be a more susceptible part of the whole brain network in the early stage of AD.
The nontoxic natural compound Curcumin exerts anti-proliferative, anti-migratory, and anti-invasive properties against malignant gliomas

International Nuclear Information System (INIS)

Senft, Christian; Polacin, Margareth; Priester, Maike; Seifert, Volker; Kögel, Donat; Weissenberger, Jakob

2010-01-01

New drugs are constantly sought after to improve the survival of patients with malignant gliomas. The ideal substance would selectively target tumor cells without eliciting toxic side effects. Here, we report on the anti-proliferative, anti-migratory, and anti-invasive properties of the natural, nontoxic compound Curcumin observed in five human glioblastoma (GBM) cell lines in vitro. We used monolayer wound healing assays, modified Boyden chamber trans-well assays, and cell growth assays to quantify cell migration, invasion, and proliferation in the absence or presence of Curcumin at various concentrations. Levels of the transcription factor phospho-STAT3, a potential target of Curcumin, were determined by sandwich-ELISA. Subsequent effects on transcription of genes regulating the cell cycle were analyzed by quantitative real-time PCR. Effects on apoptosis were determined by caspase assays. Curcumin potently inhibited GBM cell proliferation as well as migration and invasion in all cell lines contingent on dose. Simultaneously, levels of the biologically active phospho-STAT3 were decreased and correlated with reduced transcription of the cell cycle regulating gene c-Myc and proliferation marking Ki-67, pointing to a potential mechanism by which Curcumin slows tumor growth. Curcumin is part of the diet of millions of people every day and is without known toxic side effects. Our data show that Curcumin bears anti-proliferative, anti-migratory, and anti-invasive properties against GBM cells in vitro. These results warrant further in vivo analyses and indicate a potential role of Curcumin in the treatment of malignant gliomas
PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of post-traumatic epilepsy.

Science.gov (United States)

Berdichevsky, Yevgeny; Dryer, Alexandra M; Saponjian, Yero; Mahoney, Mark M; Pimentel, Corrin A; Lucini, Corrina A; Usenovic, Marija; Staley, Kevin J

2013-05-22

mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an anti-epileptogenic, or merely anticonvulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long-term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordings, and cell death was quantified with lactate dehydrogenase (LDH) release measurements and Nissl-stained neuron counts. Lactate and LDH measurements were well correlated with electrographic activity and neuron counts, respectively. Inhibition of PI3K and Akt prevented activation of mTOR, and was as effective as inhibition of mTOR in reducing ictal activity and cell death. A dual inhibitor of PI3K and mTOR, NVP-BEZ235, was also effective. Inhibition of mTOR with rapamycin reduced axon sprouting. Late start of rapamycin treatment was effective in reducing epileptic activity and cell death, while early termination of rapamycin treatment did not result in increased epileptic activity or cell death. The conclusions of the study are as follows: (1) the organotypic hippocampal culture model of post-traumatic epilepsy comprises a rapid assay of anti-epileptogenic and neuroprotective activities and, in this model (2) mTOR activation depends on PI3K-Akt signaling, and (3) transient inhibition of mTOR has sustained effects on epilepsy.
Online Epileptic Seizure Prediction Using Wavelet-Based Bi-Phase Correlation of Electrical Signals Tomography.

Science.gov (United States)

Vahabi, Zahra; Amirfattahi, Rasoul; Shayegh, Farzaneh; Ghassemi, Fahimeh

2015-09-01

Considerable efforts have been made in order to predict seizures. Among these methods, the ones that quantify synchronization between brain areas, are the most important methods. However, to date, a practically acceptable result has not been reported. In this paper, we use a synchronization measurement method that is derived according to the ability of bi-spectrum in determining the nonlinear properties of a system. In this method, first, temporal variation of the bi-spectrum of different channels of electro cardiography (ECoG) signals are obtained via an extended wavelet-based time-frequency analysis method; then, to compare different channels, the bi-phase correlation measure is introduced. Since, in this way, the temporal variation of the amount of nonlinear coupling between brain regions, which have not been considered yet, are taken into account, results are more reliable than the conventional phase-synchronization measures. It is shown that, for 21 patients of FSPEEG database, bi-phase correlation can discriminate the pre-ictal and ictal states, with very low false positive rates (FPRs) (average: 0.078/h) and high sensitivity (100%). However, the proposed seizure predictor still cannot significantly overcome the random predictor for all patients.

Comparison of short-range rapidity correlations in anti pp and pp interactions at √S = 53 GeV

International Nuclear Information System (INIS)

Breakstone, A.; Crawley, H.B.; Firestone, A.; Gorbics, M.; Lamsa, J.W.; Meyer, W.T.

1982-01-01

Measurements are presented of two-particle rapidity correlations in anti pp and pp at √S = 53 GeV. The data were recorded at the CERN-ISR using the Split Field Magnet spectrometer with a minimum bias trigger. Short range correlations in normal inelastic events with measured charged multiplicities nsub(ch) >= 4 are observed for pairs of charged particles in all charge combinations. Within the experimental errors no differences are observed between the analogous correlations in pp and anti pp interactions. (orig.)
Photon correlation in single-photon frequency upconversion.

Science.gov (United States)

Gu, Xiaorong; Huang, Kun; Pan, Haifeng; Wu, E; Zeng, Heping

2012-01-30

We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.
Isorhynchophylline, a Potent Plant Alkaloid, Induces Apoptotic and Anti-Metastatic Effects in Human Hepatocellular Carcinoma Cells through the Modulation of Diverse Cell Signaling Cascades.

Science.gov (United States)

Lee, Hanwool; Baek, Seung Ho; Lee, Jong Hyun; Kim, Chulwon; Ko, Jeong-Hyeon; Lee, Seok-Geun; Chinnathambi, Arunachalam; Alharbi, Sulaiman Ali; Yang, Woong Mo; Um, Jae-Young; Sethi, Gautam; Ahn, Kwang Seok

2017-05-19

Isorhynchophylline (Rhy) is an active pharmacological component of Uncaria rhynchophylla that has been reported previously to exert significant antihypertensive and neuroprotective effects. However, very little is known about its potential anti-cancer activities. This study was carried out to evaluate the anticancer effects of Rhy against various human carcinoma cell lines. We found that Rhy exhibited substantial cytotoxic effect against human hepatocellular carcinoma HepG2 cells when compared with other human carcinoma cell lines including those of lung, pancreas, prostate, head and neck, breast, multiple myeloma, brain and renal cell carcinoma. Rhy induced apoptosis as characterized by accumulation of cells in sub G1 phase; positive Annexin V binding; activation of caspase-8, -9, and -3; and cleavage of PARP (poly-ADP ribose polymerase). This effect of Rhy correlated with the down-regulation of various proteins that mediated cell proliferation, cell survival, metastasis, and angiogenesis. Moreover, cell proliferation, migration, and constitutive CXCR4 (C-X-C chemokine receptor type 4), MMP-9 (Matrix metallopeptidase-9), and MMP-2 expression were inhibited upon Rhy treatment. We further investigated the effect of Rhy on the oncogenic cell signaling cascades through phospho-kinase array profiling assay. Rhy was found to abrogate phospho-p38, ERK, JNK, CREB, c-Jun, Akt, and STAT3 signals, but interestingly enhanced phospho-p53 signal. Overall, our results indicate, for the first time, that Rhy could exert anticancer and anti-metastatic effects through regulation of multiple signaling cascades in hepatocellular carcinoma cells.
Requirement for aspartate-cleaved bid in apoptosis signaling by DNA-damaging anti-cancer regimens

NARCIS (Netherlands)

Werner, Arlette B.; Tait, Stephen W. G.; de Vries, Evert; Eldering, Eric; Borst, Jannie

2004-01-01

Lymphoid malignancies can escape from DNA-damaging anti-cancer drugs and gamma-radiation by blocking apoptosis-signaling pathways. How these regimens induce apoptosis is incompletely defined, especially in cells with nonfunctional p53. We report here that the BH3-only Bcl-2 family member Bid is
A KST framework for correlation network construction from time series signals

Science.gov (United States)

Qi, Jin-Peng; Gu, Quan; Zhu, Ying; Zhang, Ping

2018-04-01

A KST (Kolmogorov-Smirnov test and T statistic) method is used for construction of a correlation network based on the fluctuation of each time series within the multivariate time signals. In this method, each time series is divided equally into multiple segments, and the maximal data fluctuation in each segment is calculated by a KST change detection procedure. Connections between each time series are derived from the data fluctuation matrix, and are used for construction of the fluctuation correlation network (FCN). The method was tested with synthetic simulations and the result was compared with those from using KS or T only for detection of data fluctuation. The novelty of this study is that the correlation analyses was based on the data fluctuation in each segment of each time series rather than on the original time signals, which would be more meaningful for many real world applications and for analysis of large-scale time signals where prior knowledge is uncertain.
Mixed signal learning by spike correlation propagation in feedback inhibitory circuits.

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Naoki Hiratani

2015-04-01

Full Text Available The brain can learn and detect mixed input signals masked by various types of noise, and spike-timing-dependent plasticity (STDP is the candidate synaptic level mechanism. Because sensory inputs typically have spike correlation, and local circuits have dense feedback connections, input spikes cause the propagation of spike correlation in lateral circuits; however, it is largely unknown how this secondary correlation generated by lateral circuits influences learning processes through STDP, or whether it is beneficial to achieve efficient spike-based learning from uncertain stimuli. To explore the answers to these questions, we construct models of feedforward networks with lateral inhibitory circuits and study how propagated correlation influences STDP learning, and what kind of learning algorithm such circuits achieve. We derive analytical conditions at which neurons detect minor signals with STDP, and show that depending on the origin of the noise, different correlation timescales are useful for learning. In particular, we show that non-precise spike correlation is beneficial for learning in the presence of cross-talk noise. We also show that by considering excitatory and inhibitory STDP at lateral connections, the circuit can acquire a lateral structure optimal for signal detection. In addition, we demonstrate that the model performs blind source separation in a manner similar to the sequential sampling approximation of the Bayesian independent component analysis algorithm. Our results provide a basic understanding of STDP learning in feedback circuits by integrating analyses from both dynamical systems and information theory.
Methodological Framework for Estimating the Correlation Dimension in HRV Signals

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Juan Bolea

2014-01-01

Full Text Available This paper presents a methodological framework for robust estimation of the correlation dimension in HRV signals. It includes (i a fast algorithm for on-line computation of correlation sums; (ii log-log curves fitting to a sigmoidal function for robust maximum slope estimation discarding the estimation according to fitting requirements; (iii three different approaches for linear region slope estimation based on latter point; and (iv exponential fitting for robust estimation of saturation level of slope series with increasing embedded dimension to finally obtain the correlation dimension estimate. Each approach for slope estimation leads to a correlation dimension estimate, called D^2, D^2⊥, and D^2max. D^2 and D^2max estimate the theoretical value of correlation dimension for the Lorenz attractor with relative error of 4%, and D^2⊥ with 1%. The three approaches are applied to HRV signals of pregnant women before spinal anesthesia for cesarean delivery in order to identify patients at risk for hypotension. D^2 keeps the 81% of accuracy previously described in the literature while D^2⊥ and D^2max approaches reach 91% of accuracy in the same database.
Anti-Correlated Cerebrospinal Fluid Biomarker Trajectories in Preclinical Alzheimer's Disease.

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Gomar, Jesus J; Conejero-Goldberg, Concepcion; Davies, Peter; Goldberg, Terry E

2016-01-01

The earliest stage of preclinical Alzheimer's disease (AD) is defined by low levels of cerebrospinal fluid (CSF) amyloid-β (Aβ42). However, covariance in longitudinal dynamic change of Aβ42 and tau in incipient preclinical AD is poorly understood. To examine dynamic interrelationships between Aβ42 and tau in preclinical AD. We followed 47 cognitively intact participants (CI) with available CSF data over four years in ADNI. Based on longitudinal Aβ42 levels in CSF, CI were classified into three groups: 1) Aβ42 stable with normal levels of Aβ42 over time (n = 15); 2) Aβ42 declining with normal Aβ42 levels at baseline but showing decline over time (n = 14); and 3) Aβ42 levels consistently abnormal (n = 18). In the Aβ42 declining group, suggestive of incipient preclinical AD, CSF phosphorylated tau (p-tau) showed a similar longitudinal pattern of increasing abnormality over time (p = 0.0001). Correlation between longitudinal slopes of Aβ42 and p-tau confirmed that both trajectories were anti-correlated (rho = -0.60; p = 0.02). Regression analysis showed that Aβ42 slope (decreasing Aβ42) predicted p-tau slope (increasing p-tau) (R2 = 0.47, p = 0.03). Atrophy in the hippocampus was predicted by the interaction of Aβ42 and p-tau slopes (p anti-correlated trajectory, i.e., as Aβ42 declined, p-tau increased, and thus was suggestive of strong temporal coincidence. Rapid pathogenic cross-talk between Aβ42 and p-tau thus may be evident in very early stages of preclinical AD.
Calibration of Correlation Radiometers Using Pseudo-Random Noise Signals

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Sebastián Pantoja

2009-08-01

Full Text Available The calibration of correlation radiometers, and particularly aperture synthesis interferometric radiometers, is a critical issue to ensure their performance. Current calibration techniques are based on the measurement of the cross-correlation of receivers’ outputs when injecting noise from a common noise source requiring a very stable distribution network. For large interferometric radiometers this centralized noise injection approach is very complex from the point of view of mass, volume and phase/amplitude equalization. Distributed noise injection techniques have been proposed as a feasible alternative, but are unable to correct for the so-called “baseline errors” associated with the particular pair of receivers forming the baseline. In this work it is proposed the use of centralized Pseudo-Random Noise (PRN signals to calibrate correlation radiometers. PRNs are sequences of symbols with a long repetition period that have a flat spectrum over a bandwidth which is determined by the symbol rate. Since their spectrum resembles that of thermal noise, they can be used to calibrate correlation radiometers. At the same time, since these sequences are deterministic, new calibration schemes can be envisaged, such as the correlation of each receiver’s output with a baseband local replica of the PRN sequence, as well as new distribution schemes of calibration signals. This work analyzes the general requirements and performance of using PRN sequences for the calibration of microwave correlation radiometers, and particularizes the study to a potential implementation in a large aperture synthesis radiometer using an optical distribution network.
A jackknife approach to quantifying single-trial correlation between covariance-based metrics undefined on a single-trial basis.

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Richter, Craig G; Thompson, William H; Bosman, Conrado A; Fries, Pascal

2015-07-01

The quantification of covariance between neuronal activities (functional connectivity) requires the observation of correlated changes and therefore multiple observations. The strength of such neuronal correlations may itself undergo moment-by-moment fluctuations, which might e.g. lead to fluctuations in single-trial metrics such as reaction time (RT), or may co-fluctuate with the correlation between activity in other brain areas. Yet, quantifying the relation between moment-by-moment co-fluctuations in neuronal correlations is precluded by the fact that neuronal correlations are not defined per single observation. The proposed solution quantifies this relation by first calculating neuronal correlations for all leave-one-out subsamples (i.e. the jackknife replications of all observations) and then correlating these values. Because the correlation is calculated between jackknife replications, we address this approach as jackknife correlation (JC). First, we demonstrate the equivalence of JC to conventional correlation for simulated paired data that are defined per observation and therefore allow the calculation of conventional correlation. While the JC recovers the conventional correlation precisely, alternative approaches, like sorting-and-binning, result in detrimental effects of the analysis parameters. We then explore the case of relating two spectral correlation metrics, like coherence, that require multiple observation epochs, where the only viable alternative analysis approaches are based on some form of epoch subdivision, which results in reduced spectral resolution and poor spectral estimators. We show that JC outperforms these approaches, particularly for short epoch lengths, without sacrificing any spectral resolution. Finally, we note that the JC can be applied to relate fluctuations in any smooth metric that is not defined on single observations. Copyright © 2015. Published by Elsevier Inc.
Adaptive endpoint detection of seismic signal based on auto-correlated function

International Nuclear Information System (INIS)

Fan Wanchun; Shi Ren

2000-01-01

There are certain shortcomings for the endpoint detection by time-waveform envelope and/or by checking the travel table (both labelled as the artificial detection method). Based on the analysis of the auto-correlation function, the notion of the distance between auto-correlation functions was quoted, and the characterizations of the noise and the signal with noise were discussed by using the distance. Then, the method of auto-adaptable endpoint detection of seismic signal based on auto-correlated similarity was summed up. The steps of implementation and determining of the thresholds were presented in detail. The experimental results that were compared with the methods based on artificial detecting show that this method has higher sensitivity even in a low SNR circumstance
A New Wavelet Threshold Determination Method Considering Interscale Correlation in Signal Denoising

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Can He

2015-01-01

Full Text Available Due to simple calculation and good denoising effect, wavelet threshold denoising method has been widely used in signal denoising. In this method, the threshold is an important parameter that affects the denoising effect. In order to improve the denoising effect of the existing methods, a new threshold considering interscale correlation is presented. Firstly, a new correlation index is proposed based on the propagation characteristics of the wavelet coefficients. Then, a threshold determination strategy is obtained using the new index. At the end of the paper, a simulation experiment is given to verify the effectiveness of the proposed method. In the experiment, four benchmark signals are used as test signals. Simulation results show that the proposed method can achieve a good denoising effect under various signal types, noise intensities, and thresholding functions.
Correlating behavioral responses to FMRI signals from human prefrontal cortex: examining cognitive processes using task analysis.

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DeSouza, Joseph F X; Ovaysikia, Shima; Pynn, Laura

2012-06-20

The aim of this methods paper is to describe how to implement a neuroimaging technique to examine complementary brain processes engaged by two similar tasks. Participants' behavior during task performance in an fMRI scanner can then be correlated to the brain activity using the blood-oxygen-level-dependent signal. We measure behavior to be able to sort correct trials, where the subject performed the task correctly and then be able to examine the brain signals related to correct performance. Conversely, if subjects do not perform the task correctly, and these trials are included in the same analysis with the correct trials we would introduce trials that were not only for correct performance. Thus, in many cases these errors can be used themselves to then correlate brain activity to them. We describe two complementary tasks that are used in our lab to examine the brain during suppression of an automatic responses: the stroop(1) and anti-saccade tasks. The emotional stroop paradigm instructs participants to either report the superimposed emotional 'word' across the affective faces or the facial 'expressions' of the face stimuli(1,2). When the word and the facial expression refer to different emotions, a conflict between what must be said and what is automatically read occurs. The participant has to resolve the conflict between two simultaneously competing processes of word reading and facial expression. Our urge to read out a word leads to strong 'stimulus-response (SR)' associations; hence inhibiting these strong SR's is difficult and participants are prone to making errors. Overcoming this conflict and directing attention away from the face or the word requires the subject to inhibit bottom up processes which typically directs attention to the more salient stimulus. Similarly, in the anti-saccade task(3,4,5,6), where an instruction cue is used to direct only attention to a peripheral stimulus location but then the eye movement is made to the mirror opposite position
Isorhynchophylline, a Potent Plant Alkaloid, Induces Apoptotic and Anti-Metastatic Effects in Human Hepatocellular Carcinoma Cells through the Modulation of Diverse Cell Signaling Cascades

Directory of Open Access Journals (Sweden)

Hanwool Lee

2017-05-01

Full Text Available Isorhynchophylline (Rhy is an active pharmacological component of Uncaria rhynchophylla that has been reported previously to exert significant antihypertensive and neuroprotective effects. However, very little is known about its potential anti-cancer activities. This study was carried out to evaluate the anticancer effects of Rhy against various human carcinoma cell lines. We found that Rhy exhibited substantial cytotoxic effect against human hepatocellular carcinoma HepG2 cells when compared with other human carcinoma cell lines including those of lung, pancreas, prostate, head and neck, breast, multiple myeloma, brain and renal cell carcinoma. Rhy induced apoptosis as characterized by accumulation of cells in sub G1 phase; positive Annexin V binding; activation of caspase-8, -9, and -3; and cleavage of PARP (poly-ADP ribose polymerase. This effect of Rhy correlated with the down-regulation of various proteins that mediated cell proliferation, cell survival, metastasis, and angiogenesis. Moreover, cell proliferation, migration, and constitutive CXCR4 (C-X-C chemokine receptor type 4, MMP-9 (Matrix metallopeptidase-9, and MMP-2 expression were inhibited upon Rhy treatment. We further investigated the effect of Rhy on the oncogenic cell signaling cascades through phospho-kinase array profiling assay. Rhy was found to abrogate phospho-p38, ERK, JNK, CREB, c-Jun, Akt, and STAT3 signals, but interestingly enhanced phospho-p53 signal. Overall, our results indicate, for the first time, that Rhy could exert anticancer and anti-metastatic effects through regulation of multiple signaling cascades in hepatocellular carcinoma cells.
Isorhynchophylline, a Potent Plant Alkaloid, Induces Apoptotic and Anti-Metastatic Effects in Human Hepatocellular Carcinoma Cells through the Modulation of Diverse Cell Signaling Cascades

Science.gov (United States)

Lee, Hanwool; Baek, Seung Ho; Lee, Jong Hyun; Kim, Chulwon; Ko, Jeong-Hyeon; Lee, Seok-Geun; Chinnathambi, Arunachalam; Alharbi, Sulaiman Ali; Yang, Woong Mo; Um, Jae-Young; Sethi, Gautam; Ahn, Kwang Seok

2017-01-01

Isorhynchophylline (Rhy) is an active pharmacological component of Uncaria rhynchophylla that has been reported previously to exert significant antihypertensive and neuroprotective effects. However, very little is known about its potential anti-cancer activities. This study was carried out to evaluate the anticancer effects of Rhy against various human carcinoma cell lines. We found that Rhy exhibited substantial cytotoxic effect against human hepatocellular carcinoma HepG2 cells when compared with other human carcinoma cell lines including those of lung, pancreas, prostate, head and neck, breast, multiple myeloma, brain and renal cell carcinoma. Rhy induced apoptosis as characterized by accumulation of cells in sub G1 phase; positive Annexin V binding; activation of caspase-8, -9, and -3; and cleavage of PARP (poly-ADP ribose polymerase). This effect of Rhy correlated with the down-regulation of various proteins that mediated cell proliferation, cell survival, metastasis, and angiogenesis. Moreover, cell proliferation, migration, and constitutive CXCR4 (C-X-C chemokine receptor type 4), MMP-9 (Matrix metallopeptidase-9), and MMP-2 expression were inhibited upon Rhy treatment. We further investigated the effect of Rhy on the oncogenic cell signaling cascades through phospho-kinase array profiling assay. Rhy was found to abrogate phospho-p38, ERK, JNK, CREB, c-Jun, Akt, and STAT3 signals, but interestingly enhanced phospho-p53 signal. Overall, our results indicate, for the first time, that Rhy could exert anticancer and anti-metastatic effects through regulation of multiple signaling cascades in hepatocellular carcinoma cells. PMID:28534824
Characteristics of the process K+p→K+anti ppp at 12 GeV/c

International Nuclear Information System (INIS)

Armstrong, T.A.; Frame, D.; Hughes, I.S.; Kumar, B.R.; Lewis, G.M.; Macallister, J.B.; Stewart, D.T.; Turnbull, R.M.

1979-01-01

Data are presented on the reaction K + p→K + anti ppp at 12 GeV/c from an experiment using the OMEGA spectrometer at CERN. A clear Λ(1520) signal is observed in the process K + p→anti Λ(1520)pp and angular distributions and correlations are presented for this process. The angular distributions for the reaction in which anti Λ(1520) is not produced show an appreciable backward K + peak. (Auth.)
Neural Correlates of Success and Failure Signals During Neurofeedback Learning.

Science.gov (United States)

Radua, Joaquim; Stoica, Teodora; Scheinost, Dustin; Pittenger, Christopher; Hampson, Michelle

2018-05-15

Feedback-driven learning, observed across phylogeny and of clear adaptive value, is frequently operationalized in simple operant conditioning paradigms, but it can be much more complex, driven by abstract representations of success and failure. This study investigates the neural processes involved in processing success and failure during feedback learning, which are not well understood. Data analyzed were acquired during a multisession neurofeedback experiment in which ten participants were presented with, and instructed to modulate, the activity of their orbitofrontal cortex with the aim of decreasing their anxiety. We assessed the regional blood-oxygenation-level-dependent response to the individualized neurofeedback signals of success and failure across twelve functional runs acquired in two different magnetic resonance sessions in each of ten individuals. Neurofeedback signals of failure correlated early during learning with deactivation in the precuneus/posterior cingulate and neurofeedback signals of success correlated later during learning with deactivation in the medial prefrontal/anterior cingulate cortex. The intensity of the latter deactivations predicted the efficacy of the neurofeedback intervention in the reduction of anxiety. These findings indicate a role for regulation of the default mode network during feedback learning, and suggest a higher sensitivity to signals of failure during the early feedback learning and to signals of success subsequently. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.
Anti-mutated citrullinated vimentin (anti-MCV) and anti-65 kDa heat shock protein (anti-hsp65): new biomarkers in ankylosing spondylitis.

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Bodnár, Nóra; Szekanecz, Zoltán; Prohászka, Zoltán; Kemény-Beke, Adám; Némethné-Gyurcsik, Zsuzsanna; Gulyás, Katalin; Lakos, Gabriella; Sipka, Sándor; Szántó, Sándor

2012-01-01

Citrullination as well as anti-citrullinated protein/peptide antibodies (ACPA) have been implicated in the pathogenesis of rheumatoid arthritis (RA). While ACPAs are specific and sensitive markers for RA, there have been hardly any reports regarding ACPAs in ankylosing spondylitis (AS). The possible role of antibodies to Mycobacterial 65 kDa heat shock protein (hsp65) has not been characterized in AS. As new laboratory biomarkers of AS are needed, we investigated the prevalence of anti-mutated citrullinated vimentin (MCV) and anti-hsp65 antibodies in AS. Altogether 43 AS and 44 healthy controls were included in the study. Anti-MCV and anti-hsp65 were determined in sera by commercial and in-house ELISA, respectively. Serum autoantibody levels were correlated with ESR, CRP, HLA-B27 status, smoking habits, pain intensity, BASDAI, BASFI and BASMI indices. Patients with AS had significantly higher serum anti-MCV levels (17.3 U/mL, range: 8.3-31.5 U/mL) in comparison to healthy subjects (8.9 U/mL, range: 5.4-13.3 U/mL) (p20 U/mL). The mean anti-hsp65 concentration in AS sera was 124.8 AU/mL (range: 27.2-1000 AU/mL), while controls exerted significantly lower anti-hsp65 levels (mean: 51.8 AU/mL; range: 22.5-88.5 AU/mL) (p<0.001). Correlation analysis revealed that both anti-MCV positivity (r=0.613; p=0.012) and absolute serum anti-MCV levels (r=0.553; p=0.021) correlated with anti-hsp65 levels. Anti-MCV positivity also correlated with ESR (r=0.437; p=0.03). Anti-MCV and anti-hsp65 may be novel biomarkers in AS. Copyright © 2011. Published by Elsevier SAS.
On the possibility to detect the Higgs decay H → b anti b in the associated Z + b anti b production at the LHC

International Nuclear Information System (INIS)

Lipatov, A.V.; Zotov, N.P.

2015-01-01

We investigate the possibility to detect the scalar Higgs boson decay H → b anti b in the associated Z and b anti b production at the LHC using the k T -factorization QCD approach. Our consideration is based on the off-shell (i.e. depending on the transverse momenta of initial quarks and gluons) production amplitudes of q* anti q* → ZH → Zq' anti q', q* anti q* → Zq' anti q', and g*g* → Zq' anti q' partonic subprocesses supplemented with the Catani.Ciafoloni.Fiorani. Marchesini (CCFM) dynamics of parton densities in a proton. We argue that the H → b anti b signal could be observed at large transverse momenta near the Higgs boson peak despite the overwhelming QCD background, and we point out the important role of angular correlations between the produced Z boson and b-quarks. (orig.)
Correlation between laser-induced breakdown spectroscopy signal and moisture content

International Nuclear Information System (INIS)

Liu, Yuan; Gigant, Lionel; Baudelet, Matthieu; Richardson, Martin

2012-01-01

The possibility of using Laser-Induced Breakdown Spectroscopy (LIBS) for measuring the moisture content of fresh food samples is studied. The normalized line emission of oxygen is highly correlated with the moisture content of the sample, cheese in our case, and can be used as a moisture marker in situations where oxygen interference from the matrix is not a critical issue. The linear correlation between the oxygen signal and the moisture content in the sample shows great potential for using LIBS as an alternative spectroscopic method for moisture monitoring. - Highlights: ► Quantitative moisture measurement by LIBS. ► Use of matrix effects and normalization for physical information on the sample. ► Use of signal from oxygen and CN radical in air background for moisture measurement.

PDK1 in NF-κB signaling is a target of Xanthium strumarium methanolic extract-mediated anti-inflammatory activities.

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Hossen, Muhammad Jahangir; Cho, Jae Youl; Kim, Daewon

2016-08-22

Xanthium strumarium L. (Asteraceae) has traditionally been used to treat bacterial infections, nasal sinusitis, urticaria, arthritis, chronic bronchitis and rhinitis, allergic rhinitis, edema, lumbago, and other ailments. However, the molecular mechanisms by which this plant exerts its anti-inflammatory effects are poorly characterized. Here we studied the immunopharmacological activities of the methanolic extract of the aerial parts of this plant (Xs-ME) and validated its pharmacological targets. To evaluate the anti-inflammatory activity of Xs-ME, we employed lipopolysaccharide (LPS)-treated macrophages and an HCl/EtOH-induced mouse model of gastritis. We also used HPLC to identify the potentially active anti-inflammatory components of this extract. The molecular mechanisms of its anti-inflammatory activity were studied by kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) were both suppressed by Xs-ME. Moreover, orally administered Xs-ME ameliorated HCl/EtOH-induced gastric lesions. Furthermore, this extract downregulated the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 and reduced the nuclear levels of NF-κB. Signaling events upstream of NF-κB translocation, such as phosphorylation of AKT and the formation of PDK1-AKT signaling complexes, were also inhibited by Xs-ME. Moreover, Xs-ME suppressed the enzymatic activity of PDK1. Additionally, PDK1-induced luciferase activity and Akt phosphorylation were both inhibited by Xs-ME. We also identified the polyphenol resveratrol as a likely active anti-inflammatory component in Xs-ME that targets PDK1. Xs-ME exerts anti-inflammatory activity in vitro and in vivo by inhibiting PDK1 kinase activity and blocking signaling to its downstream transcription factor, NF-κB. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Visualization of synchronization of the uterine contraction signals: running cross-correlation and wavelet running cross-correlation methods.

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Oczeretko, Edward; Swiatecka, Jolanta; Kitlas, Agnieszka; Laudanski, Tadeusz; Pierzynski, Piotr

2006-01-01

In physiological research, we often study multivariate data sets, containing two or more simultaneously recorded time series. The aim of this paper is to present the cross-correlation and the wavelet cross-correlation methods to assess synchronization between contractions in different topographic regions of the uterus. From a medical point of view, it is important to identify time delays between contractions, which may be of potential diagnostic significance in various pathologies. The cross-correlation was computed in a moving window with a width corresponding to approximately two or three contractions. As a result, the running cross-correlation function was obtained. The propagation% parameter assessed from this function allows quantitative description of synchronization in bivariate time series. In general, the uterine contraction signals are very complicated. Wavelet transforms provide insight into the structure of the time series at various frequencies (scales). To show the changes of the propagation% parameter along scales, a wavelet running cross-correlation was used. At first, the continuous wavelet transforms as the uterine contraction signals were received and afterwards, a running cross-correlation analysis was conducted for each pair of transformed time series. The findings show that running functions are very useful in the analysis of uterine contractions.
Exploring anti-correlated radio/X-ray modes in transitional millisecond pulsars

Science.gov (United States)

Jaodand, Amruta

2017-09-01

Recently, using coordinated VLA+Chandra observations, Bogdanov et al.(2017) have uncovered a stunning anti-correlation in the LMXB state of the tMSP PSR J1023+0038. They see that radio luminosity consistently peaks during the X-ray `low' luminosity modes. Also, we have found a promising candidate tMSP, 3FGL J1544-1125(J1544) (Bogdanov and Halpern 2015; currently only tMSP candidate apart from J1023 in a persistent LMXB state). Using VLA and simultaneous Swift observations we see that it lies on the proposed tMSP track in radio vs. X-ray luminosity (L_ R/L_X) diagram. This finding strengthens its classification as a tMSP and provides an excellent opportunity to a)determine universality of radio/X-ray brightness anti-correlatio and b)understand jet/outflow formation in tMSPs.
Burst-induced anti-Hebbian depression acts through short-term synaptic dynamics to cancel redundant sensory signals.

Science.gov (United States)

Harvey-Girard, Erik; Lewis, John; Maler, Leonard

2010-04-28

Weakly electric fish can enhance the detection and localization of important signals such as those of prey in part by cancellation of redundant spatially diffuse electric signals due to, e.g., their tail bending. The cancellation mechanism is based on descending input, conveyed by parallel fibers emanating from cerebellar granule cells, that produces a negative image of the global low-frequency signals in pyramidal cells within the first-order electrosensory region, the electrosensory lateral line lobe (ELL). Here we demonstrate that the parallel fiber synaptic input to ELL pyramidal cell undergoes long-term depression (LTD) whenever both parallel fiber afferents and their target cells are stimulated to produce paired burst discharges. Paired large bursts (4-4) induce robust LTD over pre-post delays of up to +/-50 ms, whereas smaller bursts (2-2) induce weaker LTD. Single spikes (either presynaptic or postsynaptic) paired with bursts did not induce LTD. Tetanic presynaptic stimulation was also ineffective in inducing LTD. Thus, we have demonstrated a form of anti-Hebbian LTD that depends on the temporal correlation of burst discharge. We then demonstrated that the burst-induced LTD is postsynaptic and requires the NR2B subunit of the NMDA receptor, elevation of postsynaptic Ca(2+), and activation of CaMKIIbeta. A model incorporating local inhibitory circuitry and previously identified short-term presynaptic potentiation of the parallel fiber synapses further suggests that the combination of burst-induced LTD, presynaptic potentiation, and local inhibition may be sufficient to explain the generation of the negative image and cancellation of redundant sensory input by ELL pyramidal cells.
Blockade of Wnt-1 signaling leads to anti-tumor effects in hepatocellular carcinoma cells

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Grepper Susan

2009-09-01

Full Text Available Abstract Background Hepatocellular carcinoma (HCC is an aggressive cancer, and is the third leading cause of cancer death worldwide. Standard therapy is ineffective partly because HCC is intrinsically resistant to conventional chemotherapy. Its poor prognosis and limited treatment options make it critical to develop novel and selective chemotherapeutic agents. Since the Wnt/β-catenin pathway is essential in HCC carcinogenesis, we studied the inhibition of Wnt-1-mediated signaling as a potential molecular target in HCC. Results We demonstrated that Wnt-1 is highly expressed in human hepatoma cell lines and a subgroup of human HCC tissues compared to paired adjacent non-tumor tissues. An anti-Wnt-1 antibody dose-dependently decreased viability and proliferation of Huh7 and Hep40 cells over-expressing Wnt-1 and harboring wild type β-catenin, but did not affect normal hepatocytes with undetectable Wnt-1 expression. Apoptosis was also observed in Huh7 and Hep40 cells after treatment with anti-Wnt-1 antibody. In these two cell lines, the anti-Wnt-1 antibody decreased β-catenin/Tcf4 transcriptional activities, which were associated with down-regulation of the endogenous β-catenin/Tcf4 target genes c-Myc, cyclin D1, and survivin. Intratumoral injection of anti-Wnt-1 antibody suppressed in vivo tumor growth in a Huh7 xenograft model, which was also associated with apoptosis and reduced c-Myc, cyclin D1, and survivin expressions. Conclusion Our results suggest that Wnt-1 is a survival factor for HCC cells, and that the blockade of Wnt-1-mediated signaling may offer a potential pathway-specific therapeutic strategy for the treatment of a subgroup of HCC that over-expresses Wnt-1.
The diagnostic value of small bowel wall vascularity after sulfur hexafluoride-filled microbubble injection in patients with Crohn's disease. Correlation with the therapeutic effectiveness of specific anti-inflammatory treatment

International Nuclear Information System (INIS)

Quaia, Emilio; Migaleddu, Vincenzo; Baratella, Elisa; Pizzolato, Riccardo; Rossi, Alexia; Grotto, Maurizio; Cova, Maria Assunta

2009-01-01

Purpose: To assess the value of small bowel wall vascularity after microbubble contrast agent injection in evaluating the therapeutic effectiveness of specific anti-inflammatory treatment in patients with Crohn's disease. Materials and methods: Fifteen patients (7 male and 8 female; mean age ± SD, 40 years ± 6) with a biopsy-proven diagnosis of Crohn's disease - Crohn's disease activity index (CDAI) > 150 (n = 12 patients) or 5 mm) were included. In each patient the terminal loop was scanned by contrast-enhanced ultrasound (CEUS) after sulfur hexafluoride-filled microbubble injection before and after 6-month anti-inflammatory treatment. The vascularity of the terminal loop was quantified in gray-scale levels (0-255) by a manually drawn ROI encompassing the thickened bowel wall and it was correlated with CDAI. Result: Before the beginning of the specific treatment all patients revealed diffuse transparietal contrast enhancement after microbubble injection, except for 3 patients who revealed contrast enhancement limited to the submucosa. In 13 patients the slope of the first ascending tract and the area under the enhancement curve were significantly lower after anti-inflammatory treatment (P < 0.05; Wilcoxon test) with a significant correlation with the CDAI score (ρ = 0.85, P < 0.05). In 2 patients no significant vascularity changes were found even though a mild reduction of CDAI score was identified (from 200 to 150 gray-scale levels). Conclusion: CEUS is a useful method to assess the therapeutic effectiveness of specific medical anti-inflammatory treatment in patients with Crohn's disease.
ANTI-CORRELATED SOFT LAGS IN THE INTERMEDIATE STATE OF BLACK HOLE SOURCE GX 339-4

International Nuclear Information System (INIS)

Sriram, K.; Choi, C. S.; Rao, A. R.

2010-01-01

We report the few hundred second anti-correlated soft lags between soft and hard energy bands in the source GX 339-4 using RXTE observations. In one observation, anti-correlated soft lags were observed using the ISGRI/INTEGRAL hard energy band and the PCA/RXTE soft energy band light curves. The lags were observed when the source was in hard and soft intermediate states, i.e., in a steep power-law state. We found that the temporal and spectral properties were changed during the lag timescale. The anti-correlated soft lags are associated with spectral variability during which the geometry of the accretion disk is changed. The observed temporal and spectral variations are explained using the framework of truncated disk geometry. We found that during the lag timescale, the centroid frequency of quasi-periodic oscillation is decreased, the soft flux is decreased along with an increase in the hard flux, and the power-law index steepens together with a decrease in the disk normalization parameter. We argue that these changes could be explained if we assume that the hot corona condenses and forms a disk in the inner region of the accretion disk. The overall spectral and temporal changes support the truncated geometry of the accretion disk in the steep power-law state or in the intermediate state.
Overview of frequency bandwidth determination techniques of useful signal in case of leaks detection by correlation method

International Nuclear Information System (INIS)

Faerman, V A; Avramchuk, V S; Luneva, E E

2014-01-01

In this paper an overview of useful signal detection methods on the background of intense noise and limits determination methods of useful signal is presented. The following features are considered: peculiarities of usage of correlation analysis, cross-amplitude spectrum, coherence function, cross-phase spectrum, time-frequency correlation function in case of frequency limits determination as well as leaks detection in pipelines. The possibility of using time-frequency correlation function for solving above named issues is described. Time- frequency correlation function provides information about the signals correlation for each of the investigated frequency bands. Data about location of peaks on the surface plot of a time- frequency correlation function allows making an assumption about the spectral composition of useful signal and its frequency boundaries
Circulating levels of chromatin fragments are inversely correlated with anti-dsDNA antibody levels in human and murine systemic lupus erythematosus

DEFF Research Database (Denmark)

Jørgensen, Mariann H; Rekvig, Ole Petter; Jacobsen, Rasmus S

2011-01-01

Anti-dsDNA antibodies represent a central pathogenic factor in Lupus nephritis. Together with nucleosomes they deposit as immune complexes in the mesangial matrix and along basement membranes within the glomeruli. The origin of the nucleosomes and when they appear e.g. in circulation is not known...... an inverse correlation between anti-dsDNA antibodies and the DNA concentration in the circulation in both murine and human serum samples. High titer of anti-DNA antibodies in human sera correlated with reduced levels of circulating chromatin, and in lupus prone mice with deposition within glomeruli....... The inverse correlation between DNA concentration and anti-dsDNA antibodies may reflect antibody-dependent deposition of immune complexes during the development of lupus nephritis in autoimmune lupus prone mice. The measurement of circulating DNA in SLE sera by using qPCR may indicate and detect...
Analysis of pairwise correlations in multi-parametric PET/MR data for biological tumor characterization and treatment individualization strategies

Energy Technology Data Exchange (ETDEWEB)

Leibfarth, Sara; Moennich, David; Thorwarth, Daniela [University Hospital Tuebingen, Section for Biomedical Physics, Department of Radiation Oncology, Tuebingen (Germany); Simoncic, Urban [University Hospital Tuebingen, Section for Biomedical Physics, Department of Radiation Oncology, Tuebingen (Germany); University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana (Slovenia); Jozef Stefan Institute, Ljubljana (Slovenia); Welz, Stefan; Zips, Daniel [University Hospital Tuebingen, Department of Radiation Oncology, Tuebingen (Germany); Schmidt, Holger; Schwenzer, Nina [University Hospital Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

2016-07-15

The aim of this pilot study was to explore simultaneous functional PET/MR for biological characterization of tumors and potential future treatment adaptations. To investigate the extent of complementarity between different PET/MR-based functional datasets, a pairwise correlation analysis was performed. Functional datasets of N=15 head and neck (HN) cancer patients were evaluated. For patients of group A (N=7), combined PET/MR datasets including FDG-PET and ADC maps were available. Patients of group B (N=8) had FMISO-PET, DCE-MRI and ADC maps from combined PET/MRI, an additional dynamic FMISO-PET/CT acquired directly after FMISO tracer injection as well as an FDG-PET/CT acquired a few days earlier. From DCE-MR, parameter maps K{sup trans}, v{sub e} and v{sub p} were obtained with the extended Tofts model. Moreover, parameter maps of mean DCE enhancement, ΔS{sub DCE}, and mean FMISO signal 0-4 min p.i., anti A{sub FMISO}, were derived. Pairwise correlations were quantified using the Spearman correlation coefficient (r) on both a voxel and a regional level within the gross tumor volume. Between some pairs of functional imaging modalities moderate correlations were observed with respect to the median over all patient datasets, whereas distinct correlations were only present on an individual basis. Highest inter-modality median correlations on the voxel level were obtained for FDG/FMISO (r = 0.56), FDG/ anti A{sub FMISO} (r = 0.55), anti A{sub FMISO}/ΔS{sub DCE} (r = 0.46), and FDG/ADC (r = -0.39). Correlations on the regional level showed comparable results. The results of this study suggest that the examined functional datasets provide complementary information. However, only pairwise correlations were examined, and correlations could still exist between combinations of three or more datasets. These results might contribute to the future design of individually adapted treatment approaches based on multiparametric functional imaging.
Noise correlations in cosmic microwave background experiments

Science.gov (United States)

Dodelson, Scott; Kosowsky, Arthur; Myers, Steven T.

1995-01-01

Many analysis of microwave background experiments neglect the correlation of noise in different frequency of polarization channels. We show that these correlations, should they be present, can lead to serve misinterpretation of an experiment. In particular, correlated noise arising from either electronics or atmosphere may mimic a cosmic signal. We quantify how the likelihood function for a given experiment varies with noise correlation, using both simple analytic models and actual data. For a typical microwave background anisotropy experiment, noise correlations at the level of 1% of the overall noise can seriously reduce the significance of a given detection.
Correlation between laser-induced breakdown spectroscopy signal and moisture content

Energy Technology Data Exchange (ETDEWEB)

Liu, Yuan [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States); Gigant, Lionel [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States); Universite Bordeaux 1, 351 cours de la Liberation 33405 Talence Cedex (France); Baudelet, Matthieu, E-mail: baudelet@creol.ucf.edu [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States); Richardson, Martin [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States)

2012-07-15

The possibility of using Laser-Induced Breakdown Spectroscopy (LIBS) for measuring the moisture content of fresh food samples is studied. The normalized line emission of oxygen is highly correlated with the moisture content of the sample, cheese in our case, and can be used as a moisture marker in situations where oxygen interference from the matrix is not a critical issue. The linear correlation between the oxygen signal and the moisture content in the sample shows great potential for using LIBS as an alternative spectroscopic method for moisture monitoring. - Highlights: Black-Right-Pointing-Pointer Quantitative moisture measurement by LIBS. Black-Right-Pointing-Pointer Use of matrix effects and normalization for physical information on the sample. Black-Right-Pointing-Pointer Use of signal from oxygen and CN radical in air background for moisture measurement.
Correlation and anti-correlation of the East Asian summer and winter monsoons during the last 21,000 years.

Science.gov (United States)

Wen, Xinyu; Liu, Zhengyu; Wang, Shaowu; Cheng, Jun; Zhu, Jiang

2016-06-22

Understanding the past significant changes of the East Asia Summer Monsoon (EASM) and Winter Monsoon (EAWM) is critical for improving the projections of future climate over East Asia. One key issue that has remained outstanding from the paleo-climatic records is whether the evolution of the EASM and EAWM are correlated. Here, using a set of long-term transient simulations of the climate evolution of the last 21,000 years, we show that the EASM and EAWM are positively correlated on the orbital timescale in response to the precessional forcing, but are anti-correlated on millennial timescales in response to North Atlantic melt water forcing. The relation between EASM and EAWM can differ dramatically for different timescales because of the different response mechanisms, highlighting the complex dynamics of the East Asian monsoon system and the challenges for future projection.
Correlation techniques for the improvement of signal-to-noise ratio in measurements with stochastic processes

CERN Document Server

Reddy, V R; Reddy, T G; Reddy, P Y; Reddy, K R

2003-01-01

An AC modulation technique is described to convert stochastic signal variations into an amplitude variation and its retrieval through Fourier analysis. It is shown that this AC detection of signals of stochastic processes when processed through auto- and cross-correlation techniques improve the signal-to-noise ratio; the correlation techniques serve a similar purpose of frequency and phase filtering as that of phase-sensitive detection. A few model calculations applied to nuclear spectroscopy measurements such as Angular Correlations, Mossbauer spectroscopy and Pulse Height Analysis reveal considerable improvement in the sensitivity of signal detection. Experimental implementation of the technique is presented in terms of amplitude variations of harmonics representing the derivatives of normal spectra. Improved detection sensitivity to spectral variations is shown to be significant. These correlation techniques are general and can be made applicable to all the fields of particle counting where measurements ar...
Detailed L3 measurements of Bose-Einstein correlations and a region of anti-correlations in hadronic $Z^0$ decays at LEP

CERN Document Server

Csorgo, T.; Kittel, W.; Novak, T.

2010-01-01

L3 preliminary data of two-particle Bose-Einstein correlations are reported for hadronic Z^0 decays in e+e- annihilation at LEP. The invariant relative momentum Q is identified as the eigenvariable of the measured correlation function. Significant anti-correlations are observed in the Bose-Einstein correlation function in a broad region of 0.5 - 1.6 GeV with a minimum at Q close to 0.8 GeV. Absence of Bose-Einstein correlations is demonstrated in the region above Q >= 1.6 GeV. The effective source size is found to decrease with increasing value of the transverse mass of the pair, similarly to hadron-hadron and heavy ion reactions. These feautes and our data are described well by the non-thermal tau-model, which is based on strong space-time momentum-correlations.
Anti-apoptotic signaling and failure of apoptosis in the ischemic rat hippocampus

DEFF Research Database (Denmark)

Müller, Georg Johannes; Lassmann, Hans; Johansen, Flemming Fryd

2007-01-01

Several anti-apoptotic proteins are induced in CA1 neurons after transient forebrain ischemia (TFI), but fail to protect the majority of these cells from demise. Correlating cell death morphologies (apoptosis-like and necrosis-like death) with immunohistochemistry (IHC), we investigated whether...... anti-apoptosis contributes to survival, compromises apoptosis effector functions and/or delays death in CA1 neurons 1-7 days after TFI. As surrogate markers for bioenergetic failure, the IHC of respiratory chain complex (RCC) subunits was investigated. Dentate granule cell (DGC) apoptosis following...... colchicine injection severed as a reference for classical apoptosis. Heat shock protein 70 (Hsp70), neuronal apoptosis inhibitory protein (NAIP) and manganese superoxide dismutase (MnSOD) were upregulated in the majority of intact CA1 neurons paralleling the occurrence of CA1 neuronal death (days 3...
Quantifying NMR relaxation correlation and exchange in articular cartilage with time domain analysis

Science.gov (United States)

Mailhiot, Sarah E.; Zong, Fangrong; Maneval, James E.; June, Ronald K.; Galvosas, Petrik; Seymour, Joseph D.

2018-02-01

Measured nuclear magnetic resonance (NMR) transverse relaxation data in articular cartilage has been shown to be multi-exponential and correlated to the health of the tissue. The observed relaxation rates are dependent on experimental parameters such as solvent, data acquisition methods, data analysis methods, and alignment to the magnetic field. In this study, we show that diffusive exchange occurs in porcine articular cartilage and impacts the observed relaxation rates in T1-T2 correlation experiments. By using time domain analysis of T2-T2 exchange spectroscopy, the diffusive exchange time can be quantified by measurements that use a single mixing time. Measured characteristic times for exchange are commensurate with T1 in this material and so impacts the observed T1 behavior. The approach used here allows for reliable quantification of NMR relaxation behavior in cartilage in the presence of diffusive fluid exchange between two environments.
Quantifying brain microstructure with diffusion MRI

DEFF Research Database (Denmark)

Novikov, Dmitry S.; Jespersen, Sune N.; Kiselev, Valerij G.

2016-01-01

the potential to quantify the relevant length scales for neuronal tissue, such as the packing correlation length for neuronal fibers, the degree of neuronal beading, and compartment sizes. The second avenue corresponds to the long-time limit, when the observed signal can be approximated as a sum of multiple non......-exchanging anisotropic Gaussian components. Here the challenge lies in parameter estimation and in resolving its hidden degeneracies. The third avenue employs multiple diffusion encoding techniques, able to access information not contained in the conventional diffusion propagator. We conclude with our outlook...... on the future research directions which can open exciting possibilities for developing markers of pathology and development based on methods of studying mesoscopic transport in disordered systems....
Anti-helminth compound niclosamide downregulates Wnt Signaling and elicits antitumor responses in tumors with activating APC mutations

Science.gov (United States)

Osada, Takuya; Chen, Minyong; Yang, Xiao Yi; Spasojevic, Ivan; Vandeusen, Jeffrey B.; Hsu, David; Clary, Bryan M.; Clay, Timothy M.; Chen, Wei; Morse, Michael A.; Lyerly, H. Kim

2011-01-01

Wnt/β-catenin pathway activation caused by APC mutations occurs in approximately 80% of sporadic colorectal cancers. The anti-helminth compound niclosamide downregulates components of the Wnt pathway, specifically Dishevelled-2 (Dvl2) expression, resulting in diminished downstream β-catenin signaling. In this study, we determined if niclosamide could inhibit the Wnt/ β-catenin pathway in human colorectal cancers and whether its inhibition might elicit antitumor effects in the presence of APC mutations. We found that niclosamide inhibited Wnt/ β-catenin pathway activation, downregulated Dvl2, decreased downstream β-catenin signaling and exerted anti-proliferative effects in human colon cancer cell lines and colorectal cancer cells isolated by surgical resection of metastatic disease, regardless of mutations in APC. In contrast, inhibition of NF-κB or mTOR did not exert similar anti-proliferative effects in these colorectal cancer model systems. In mice implanted with human colorectal cancer xenografts, orally administered niclosamide was well tolerated, achieved plasma and tumor levels associated with biologic activity and led to tumor control. Our findings support clinical explorations to reposition niclosamide for treatment of colorectal cancer. PMID:21531761
Circulating 25-hydroxy vitamin D correlates with serum level of anti-Müllerian hormone in male patients with chronic kidney disease.

Science.gov (United States)

Abdel Hamid, F F; Soliman, A F; Lashin, F E S

2018-02-14

This study was designed to assess the relationship between serum levels of anti-Müllerian hormone and 25-hydroxy vitamin D in chronic kidney disease male patients. For that, serum 25-hydroxy vitamin D and anti-Müllerian hormone along with follicle-stimulating hormone, luteinising hormone, prolactin, total testosterone and estradiol were assayed in 59 patients with different stages of chronic kidney disease and 21 healthy participants. Compared to controls, serum levels of anti-Müllerian hormone and 25-hydroxy vitamin D were significantly decreased in patients with chronic kidney disease. The decreased anti-Müllerian hormone level correlated positively with estimated glomerular filtration rate and serum levels of testosterone and 25-hydroxy vitamin D. Meanwhile, it was negatively correlated with age and serum levels of urea, creatinine, follicle-stimulating hormone, luteinising hormone and prolactin. 25-Hydroxy vitamin D and luteinising hormone explained the 65.9% variability of anti-Müllerian hormone in a multiple linear regression model. However, anti-Müllerian hormone in crude correlation was more strongly associated with serum 25-hydroxy vitamin D than luteinising hormone. In conclusion, serum level of 25-hydroxy vitamin D might be a determinant factor of anti-Müllerian hormone level, and their relationship might explain in part the dysfunction of Sertoli cells and the impaired testicular functions in chronic kidney disease male patients. © 2018 Blackwell Verlag GmbH.

Agatha: Disentangling period signals from correlated noise in a periodogram framework

Science.gov (United States)

Feng, F.; Tuomi, M.; Jones, H. R. A.

2018-04-01

Agatha is a framework of periodograms to disentangle periodic signals from correlated noise and to solve the two-dimensional model selection problem: signal dimension and noise model dimension. These periodograms are calculated by applying likelihood maximization and marginalization and combined in a self-consistent way. Agatha can be used to select the optimal noise model and to test the consistency of signals in time and can be applied to time series analyses in other astronomical and scientific disciplines. An interactive web implementation of the software is also available at http://agatha.herts.ac.uk/.
Digital timing: sampling frequency, anti-aliasing filter and signal interpolation filter dependence on timing resolution

International Nuclear Information System (INIS)

Cho, Sanghee; Grazioso, Ron; Zhang Nan; Aykac, Mehmet; Schmand, Matthias

2011-01-01

The main focus of our study is to investigate how the performance of digital timing methods is affected by sampling rate, anti-aliasing and signal interpolation filters. We used the Nyquist sampling theorem to address some basic questions such as what will be the minimum sampling frequencies? How accurate will the signal interpolation be? How do we validate the timing measurements? The preferred sampling rate would be as low as possible, considering the high cost and power consumption of high-speed analog-to-digital converters. However, when the sampling rate is too low, due to the aliasing effect, some artifacts are produced in the timing resolution estimations; the shape of the timing profile is distorted and the FWHM values of the profile fluctuate as the source location changes. Anti-aliasing filters are required in this case to avoid the artifacts, but the timing is degraded as a result. When the sampling rate is marginally over the Nyquist rate, a proper signal interpolation is important. A sharp roll-off (higher order) filter is required to separate the baseband signal from its replicates to avoid the aliasing, but in return the computation will be higher. We demonstrated the analysis through a digital timing study using fast LSO scintillation crystals as used in time-of-flight PET scanners. From the study, we observed that there is no significant timing resolution degradation down to 1.3 Ghz sampling frequency, and the computation requirement for the signal interpolation is reasonably low. A so-called sliding test is proposed as a validation tool checking constant timing resolution behavior of a given timing pick-off method regardless of the source location change. Lastly, the performance comparison for several digital timing methods is also shown.
CROSS-CORRELATIONS AS A COSMOLOGICAL CARBON MONOXIDE DETECTOR

International Nuclear Information System (INIS)

Pullen, Anthony R.; Doré, Olivier; Chang, Tzu-Ching; Lidz, Adam

2013-01-01

We present a new procedure to measure the large-scale carbon monoxide (CO) emissions across cosmic history. As a tracer of large-scale structure (LSS), the CO gas content as a function of redshift can be quantified by its three-dimensional fluctuation power spectra. Furthermore, cross-correlating CO emission with other LSS tracers offers a way to measure the emission as a function of scale and redshift. Here we introduce the model relevant for such a cross-correlation measurement between CO and other LSS tracers, and between different CO rotational lines. We propose a novel use of cosmic microwave background (CMB) data and attempt to extract redshifted CO emissions embedded in the Wilkinson Microwave Anisotropy Probe (WMAP) data set. We cross-correlate the all-sky WMAP7 data with LSS data sets, namely, the photometric quasar sample and the luminous red galaxy sample from the Sloan Digital Sky Survey Data Releases 6 and 7, respectively. We are unable to detect a cross-correlation signal with either CO(1-0) or CO(2-1) lines, mainly due to the instrumental noise in the WMAP data. However, we are able to rule out models more than three times greater than our more optimistic model. We discuss the cross-correlation signal from the thermal Sunyaev-Zeldovich effect and dust as potential contaminants, and quantify their impact for our CO measurements. We discuss forecasts for current CMB experiments and a hypothetical future CO-focused experiment, and propose to cross-correlate CO temperature data with the Hobby-Eberly Telescope Dark Energy Experiment Lyα-emitter sample, for which a signal-to-noise ratio of 58 is possible.
Atypical Diabetic Foot Ulcer Keratinocyte Protein Signaling Correlates with Impaired Wound Healing

Science.gov (United States)

Hoke, Glenn D.; Ramos, Corrine; Hoke, Nicholas N.; Crossland, Mary C.; Shawler, Lisa G.

2016-01-01

Diabetes mellitus is associated with chronic diabetic foot ulcers (DFUs) and wound infections often resulting in lower extremity amputations. The protein signaling architecture of the mechanisms responsible for impaired DFU healing has not been characterized. In this preliminary clinical study, the intracellular levels of proteins involved in signal transduction networks relevant to wound healing were non-biasedly measured using reverse-phase protein arrays (RPPA) in keratinocytes isolated from DFU wound biopsies. RPPA allows for the simultaneous documentation and assessment of the signaling pathways active in each DFU. Thus, RPPA provides for the accurate mapping of wound healing pathways associated with apoptosis, proliferation, senescence, survival, and angiogenesis. From the study data, we have identified potential diagnostic, or predictive, biomarkers for DFU wound healing derived from the ratios of quantified signaling protein expressions within interconnected pathways. These biomarkers may allow physicians to personalize therapeutic strategies for DFU management on an individual basis based upon the signaling architecture present in each wound. Additionally, we have identified altered, interconnected signaling pathways within DFU keratinocytes that may help guide the development of therapeutics to modulate these dysregulated pathways, many of which parallel the therapeutic targets which are the hallmarks of molecular therapies for treating cancer. PMID:27840833
Atypical Diabetic Foot Ulcer Keratinocyte Protein Signaling Correlates with Impaired Wound Healing.

Science.gov (United States)

Hoke, Glenn D; Ramos, Corrine; Hoke, Nicholas N; Crossland, Mary C; Shawler, Lisa G; Boykin, Joseph V

2016-01-01

Diabetes mellitus is associated with chronic diabetic foot ulcers (DFUs) and wound infections often resulting in lower extremity amputations. The protein signaling architecture of the mechanisms responsible for impaired DFU healing has not been characterized. In this preliminary clinical study, the intracellular levels of proteins involved in signal transduction networks relevant to wound healing were non-biasedly measured using reverse-phase protein arrays (RPPA) in keratinocytes isolated from DFU wound biopsies. RPPA allows for the simultaneous documentation and assessment of the signaling pathways active in each DFU. Thus, RPPA provides for the accurate mapping of wound healing pathways associated with apoptosis, proliferation, senescence, survival, and angiogenesis. From the study data, we have identified potential diagnostic, or predictive, biomarkers for DFU wound healing derived from the ratios of quantified signaling protein expressions within interconnected pathways. These biomarkers may allow physicians to personalize therapeutic strategies for DFU management on an individual basis based upon the signaling architecture present in each wound. Additionally, we have identified altered, interconnected signaling pathways within DFU keratinocytes that may help guide the development of therapeutics to modulate these dysregulated pathways, many of which parallel the therapeutic targets which are the hallmarks of molecular therapies for treating cancer.
Quantifying sound quality in loudspeaker reproduction

NARCIS (Netherlands)

Beerends, John G.; van Nieuwenhuizen, Kevin; van den Broek, E.L.

2016-01-01

We present PREQUEL: Perceptual Reproduction Quality Evaluation for Loudspeakers. Instead of quantifying the loudspeaker system itself, PREQUEL quantifies the overall loudspeakers' perceived sound quality by assessing their acoustic output using a set of music signals. This approach introduces a
Foundations for a time reliability correlation system to quantify human reliability

International Nuclear Information System (INIS)

Dougherty, E.M. Jr.; Fragola, J.R.

1988-01-01

Time reliability correlations (TRCs) have been used in human reliability analysis (HRA) in conjunction with probabilistic risk assessment (PRA) to quantify post-initiator human failure events. The first TRCs were judgmental but recent data taken from simulators have provided evidence for development of a system of TRCs. This system has the equational form: t = tau R X tau U , where the first factor is the lognormally distributed random variable of successful response time, derived from the simulator data, and the second factor is a unitary lognormal random variable to account for uncertainty in the model. The first random variable is further factored into a median response time and a factor to account for the dominant type of behavior assumed to be involved in the response and a second factor to account for other influences on the reliability of the response
ADCC responses and blocking of EGFR-mediated signaling and cell growth by combining the anti-EGFR antibodies imgatuzumab and cetuximab in NSCLC cells

NARCIS (Netherlands)

Kol, Arjan; Terwisscha van Scheltinga, Anton; Pool, Martin; Gerdes, Christian; de Vries, Elisabeth; de Jong, Steven

2017-01-01

Imgatuzumab is a novel glycoengineered anti-epidermal growth factor receptor (EGFR) monoclonal antibody optimized to induce both antibody-dependent cellular cytotoxicity (ADCC) and EGFR signal transduction inhibition. We investigated antiEGFR monoclonal antibodies imgatuzumab and cetuximab-induced
Comparison of algorithms to quantify muscle fatigue in upper limb muscles based on sEMG signals.

Science.gov (United States)

Kahl, Lorenz; Hofmann, Ulrich G

2016-11-01

This work compared the performance of six different fatigue detection algorithms quantifying muscle fatigue based on electromyographic signals. Surface electromyography (sEMG) was obtained by an experiment from upper arm contractions at three different load levels from twelve volunteers. Fatigue detection algorithms mean frequency (MNF), spectral moments ratio (SMR), the wavelet method WIRM1551, sample entropy (SampEn), fuzzy approximate entropy (fApEn) and recurrence quantification analysis (RQA%DET) were calculated. The resulting fatigue signals were compared considering the disturbances incorporated in fatiguing situations as well as according to the possibility to differentiate the load levels based on the fatigue signals. Furthermore we investigated the influence of the electrode locations on the fatigue detection quality and whether an optimized channel set is reasonable. The results of the MNF, SMR, WIRM1551 and fApEn algorithms fell close together. Due to the small amount of subjects in this study significant differences could not be found. In terms of disturbances the SMR algorithm showed a slight tendency to out-perform the others. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.
Low Computational Signal Acquisition for GNSS Receivers Using a Resampling Strategy and Variable Circular Correlation Time

Directory of Open Access Journals (Sweden)

Yeqing Zhang

2018-02-01

Full Text Available For the objective of essentially decreasing computational complexity and time consumption of signal acquisition, this paper explores a resampling strategy and variable circular correlation time strategy specific to broadband multi-frequency GNSS receivers. In broadband GNSS receivers, the resampling strategy is established to work on conventional acquisition algorithms by resampling the main lobe of received broadband signals with a much lower frequency. Variable circular correlation time is designed to adapt to different signal strength conditions and thereby increase the operation flexibility of GNSS signal acquisition. The acquisition threshold is defined as the ratio of the highest and second highest correlation results in the search space of carrier frequency and code phase. Moreover, computational complexity of signal acquisition is formulated by amounts of multiplication and summation operations in the acquisition process. Comparative experiments and performance analysis are conducted on four sets of real GPS L2C signals with different sampling frequencies. The results indicate that the resampling strategy can effectively decrease computation and time cost by nearly 90–94% with just slight loss of acquisition sensitivity. With circular correlation time varying from 10 ms to 20 ms, the time cost of signal acquisition has increased by about 2.7–5.6% per millisecond, with most satellites acquired successfully.
Low Computational Signal Acquisition for GNSS Receivers Using a Resampling Strategy and Variable Circular Correlation Time

Science.gov (United States)

Zhang, Yeqing; Wang, Meiling; Li, Yafeng

2018-01-01

For the objective of essentially decreasing computational complexity and time consumption of signal acquisition, this paper explores a resampling strategy and variable circular correlation time strategy specific to broadband multi-frequency GNSS receivers. In broadband GNSS receivers, the resampling strategy is established to work on conventional acquisition algorithms by resampling the main lobe of received broadband signals with a much lower frequency. Variable circular correlation time is designed to adapt to different signal strength conditions and thereby increase the operation flexibility of GNSS signal acquisition. The acquisition threshold is defined as the ratio of the highest and second highest correlation results in the search space of carrier frequency and code phase. Moreover, computational complexity of signal acquisition is formulated by amounts of multiplication and summation operations in the acquisition process. Comparative experiments and performance analysis are conducted on four sets of real GPS L2C signals with different sampling frequencies. The results indicate that the resampling strategy can effectively decrease computation and time cost by nearly 90–94% with just slight loss of acquisition sensitivity. With circular correlation time varying from 10 ms to 20 ms, the time cost of signal acquisition has increased by about 2.7–5.6% per millisecond, with most satellites acquired successfully. PMID:29495301
Serial EEG findings in anti-NMDA receptor encephalitis: correlation between clinical course and EEG.

Science.gov (United States)

Ueda, Jun; Kawamoto, Michi; Hikiami, Ryota; Ishii, Junko; Yoshimura, Hajime; Matsumoto, Riki; Kohara, Nobuo

2017-12-01

Anti-NMDA receptor encephalitis is a paraneoplastic encephalitis characterised by psychiatric features, involuntary movement, and autonomic instability. Various EEG findings in patients with anti-NMDA receptor encephalitis have been reported, however, the correlation between the EEG findings and clinical course of anti-NMDA receptor encephalitis remains unclear. We describe a patient with anti-NMDA receptor encephalitis with a focus on EEG findings, which included: status epilepticus, generalised rhythmic delta activity, excess beta activity, extreme delta brush, and paroxysmal alpha activity upon arousal from sleep, which we term"arousal alpha pattern". Initially, status epilepticus was observed on the EEG when the patient was comatose with conjugate deviation. The EEG then indicated excess beta activity, followed by the emergence of continuous slow activity, including generalised rhythmic delta activity and extreme delta brush, in the most severe phase. Slow activity gradually faded in parallel with clinical amelioration. Excess beta activity persisted, even after the patient became almost independent in daily activities, and finally disappeared with full recovery. In summary, our patient with anti-NMDA receptor encephalitis demonstrated slow activity on the EEG, including extreme delta brush during the most severe phase, which gradually faded in parallel with clinical amelioration, with excess beta activity persisting into the recovery phase.
Correlation of anti-stress ability of nuclear power plant operators with physiological and psychological indexes

International Nuclear Information System (INIS)

Liao Haihong; Liu Yulong; Li Yuan; Dai Tingting; Qiu Mengyue; Bian Huahui; Chen Weibo; Liu Chunfeng

2012-01-01

Objective: To explore the correlation of the anti-stress ability of nuclear power plant operators with their heart rate, blood pressure and mental health. Methods: A total of 136 male nuclear power plant operators received the continuous performance test (CPT) and mental health test (MHT), while 37 male senior students were used as the control group. Heart rate and blood pressure were recorded before and after the test. The nuclear power plant operators were divided to high score group and low score group by CPT scores. The correlation of the anti-stress ability and blood pressure,heart rate and their mental health was analyzed. Results: The scores of CPT and MHT test with the operators were significantly higher than those of the control group (t=-1.25, 6.25, P<0.05). After the test, the heart rate, systolic pressure and diastolic pressure of the operators were all significantly lower than those of the control group (t=-2.07, 3.28, 2.74, P<0.05). The CPT score of the high score group was lower in the heart rate, systolic pressure and diastolic pressure than the low score group (t=-3.15, -2.78, -2.54, P<0.05), while the scores of CPT and MHT were better (t=0.63, 6.90, P<0.05). CPT scores were negatively correlated with the increasing range of the heart rate, systolic pressure and diastolic pressure (r=- 0.69, -0.94, and -0.62, P<0.05), and positively correlated with the MHT scores (r=0.54, P<0.05). Conclusions: To a certain extent, CPT and MHT test can reflect the anti-stress ability and be used as one of the bases to select nuclear power plant operators and to assess their competence. (authors)
A Detection Algorithm for the BOC Signal Based on Quadrature Channel Correlation

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Bo Qian

2018-01-01

Full Text Available In order to solve the problem of detecting a BOC signal, which uses a long-period pseudo random sequence, an algorithm is presented based on quadrature channel correlation. The quadrature channel correlation method eliminates the autocorrelation component of the carrier wave, allowing for the extraction of the absolute autocorrelation peaks of the BOC sequence. If the same lag difference and height difference exist for the adjacent peaks, the BOC signal can be detected effectively using a statistical analysis of the multiple autocorrelation peaks. The simulation results show that the interference of the carrier wave component is eliminated and the autocorrelation peaks of the BOC sequence are obtained effectively without demodulation. The BOC signal can be detected effectively when the SNR is greater than −12 dB. The detection ability can be improved further by increasing the number of sampling points. The higher the ratio of the square wave subcarrier speed to the pseudo random sequence speed is, the greater the detection ability is with a lower SNR. The algorithm presented in this paper is superior to the algorithm based on the spectral correlation.
Validation of a raw data-based synchronization signal (kymogram) for phase-correlated cardiac image reconstruction

International Nuclear Information System (INIS)

Ertel, Dirk; Kachelriess, Marc; Kalender, Willi A.; Pflederer, Tobias; Achenbach, Stephan; Steffen, Peter

2008-01-01

Phase-correlated reconstruction is commonly used in computed tomography (CT)-based cardiac imaging. Alternatively to the commonly used ECG, the raw data-based kymogram function can be used as a synchronization signal. We used raw data of 100 consecutive patient exams to compare the performance of kymogram function to the ECG signal. For objective validation the correlation of the ECG and the kymogram was assessed. Additionally, we performed a double-blinded comparison of ECG-based and kymogram-based phase-correlated images. The two synchronization signals showed good correlation indicated by a mean difference in the detected heart rate of negligible 0.2 bpm. The mean image quality score was 2.0 points for kymogram-correlated images and 2.3 points for ECG-correlated images, respectively (3: best; 0: worst). The kymogram and the ECG provided images adequate for diagnosis for 93 and 97 patients, respectively. For 50% of the datasets the kymogram provided an equivalent or even higher image quality compared with the ECG signal. We conclude that an acceptable image quality can be assured in most cases by the kymogram. Improvements of image quality by the kymogram function were observed in a noticeable number of cases. The kymogram can serve as a backup solution when an ECG is not available or lacking in quality. (orig.)
Analysis of cerebral vessels dynamics using experimental data with missed segments

Science.gov (United States)

Pavlova, O. N.; Abdurashitov, A. S.; Ulanova, M. V.; Shihalov, G. M.; Semyachkina-Glushkovskaya, O. V.; Pavlov, A. N.

2018-04-01

Physiological signals often contain various bad segments that occur due to artifacts, failures of the recording equipment or varying experimental conditions. The related experimental data need to be preprocessed to avoid such parts of recordings. In the case of few bad segments, they can simply be removed from the signal and its analysis is further performed. However, when there are many extracted segments, the internal structure of the analyzed physiological process may be destroyed, and it is unclear whether such signal can be used in diagnostic-related studies. In this paper we address this problem for the case of cerebral vessels dynamics. We perform analysis of simulated data in order to reveal general features of quantifying scaling features of complex signals with distinct correlation properties and show that the effects of data loss are significantly different for experimental data with long-range correlations and anti-correlations. We conclude that the cerebral vessels dynamics is significantly less sensitive to missed data fragments as compared with signals with anti-correlated statistics.
Correlated and uncorrelated invisible temporal white noise alters mesopic rod signaling.

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Hathibelagal, Amithavikram R; Feigl, Beatrix; Kremers, Jan; Zele, Andrew J

2016-03-01

We determined how rod signaling at mesopic light levels is altered by extrinsic temporal white noise that is correlated or uncorrelated with the activity of one (magnocellular, parvocellular, or koniocellular) postreceptoral pathway. Rod and cone photoreceptor excitations were independently controlled using a four-primary photostimulator. Psychometric (Weibull) functions were measured for incremental rod pulses (50 to 250 ms) in the presence (or absence; control) of perceptually invisible subthreshold extrinsic noise. Uncorrelated (rod) noise facilitates rod detection. Correlated postreceptoral pathway noise produces differential changes in rod detection thresholds and decreases the slope of the psychometric functions. We demonstrate that invisible extrinsic noise changes rod-signaling characteristics within the three retinogeniculate pathways at mesopic illumination depending on the temporal profile of the rod stimulus and the extrinsic noise type.
Anti-Cyclic Citrullinated Peptide (Anti-CCP and Anti-Mutated Citrullinated Vimentin (Anti-MCV Relation with Extra-Articular Manifestations in Rheumatoid Arthritis

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Laura Gonzalez-Lopez

2014-01-01

Full Text Available We evaluated the association between anti-cyclic citrullinated peptide antibodies (anti-CCP and anti-mutated citrullinated vimentin antibodies (anti-MCV with the presence of extra-articular (ExRA manifestations in 225 patients with rheumatoid arthritis (RA. Ninety-five patients had ExRA and 130 had no ExRA. There was no association of anti-CCP and anti-MCV levels with the presence of ExRA as total group (P=0.40 and P=0.91, resp.. Making an analysis of individual manifestations, rheumatoid nodules were associated with positivity for rheumatoid factor (RF; (P=0.01, anti-CCP (P=0.048, and anti-MCV (P=0.02. Instead, RF, anti-CCP, or anti-MCV were not associated with SS, chronic anemia, or peripheral neuropathy. Levels of anti-CCP correlated with the score of the Health Assessment Questionnaire-Disability Index (HAQ-Di (r=0.154, P=0.03, erythrocyte sedimentation rate (ESR; (r=0.155, P=0.03, and RF (P=0.254, P<0.001, whereas anti-MCV titres only correlated with RF (r=0.169, P=0.02. On adjusted analysis, ExRA was associated with longer age (P=0.015, longer disease duration (P=0.007, higher DAS-28 score (P=0.002, and higher HAQ-DI score (P=0.007, but serum levels of anti-CCP and anti-MCV were not associated. These findings show the need to strengthen the evaluation of the pathogenic mechanisms implied in each specific ExRA manifestation.
Correlations Between Bone Mechanical Properties and Bone Composition Parameters in Mouse Models of Dominant and Recessive Osteogenesis Imperfecta and the Response to Anti-TGF-β Treatment.

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Bi, Xiaohong; Grafe, Ingo; Ding, Hao; Flores, Rene; Munivez, Elda; Jiang, Ming Ming; Dawson, Brian; Lee, Brendan; Ambrose, Catherine G

2017-02-01

Osteogenesis imperfecta (OI) is a group of genetic disorders characterized by brittle bones that are prone to fracture. Although previous studies in animal models investigated the mechanical properties and material composition of OI bone, little work has been conducted to statistically correlate these parameters to identify key compositional contributors to the impaired bone mechanical behaviors in OI. Further, although increased TGF-β signaling has been demonstrated as a contributing mechanism to the bone pathology in OI models, the relationship between mechanical properties and bone composition after anti-TGF-β treatment in OI has not been studied. Here, we performed follow-up analyses of femurs collected in an earlier study from OI mice with and without anti-TGF-β treatment from both recessive (Crtap -/- ) and dominant (Col1a2 +/P.G610C ) OI mouse models and WT mice. Mechanical properties were determined using three-point bending tests and evaluated for statistical correlation with molecular composition in bone tissue assessed by Raman spectroscopy. Statistical regression analysis was conducted to determine significant compositional determinants of mechanical integrity. Interestingly, we found differences in the relationships between bone composition and mechanical properties and in the response to anti-TGF-β treatment. Femurs of both OI models exhibited increased brittleness, which was associated with reduced collagen content and carbonate substitution. In the Col1a2 +/P.G610C femurs, reduced hydroxyapatite crystallinity was also found to be associated with increased brittleness, and increased mineral-to-collagen ratio was correlated with increased ultimate strength, elastic modulus, and bone brittleness. In both models of OI, regression analysis demonstrated that collagen content was an important predictor of the increased brittleness. In summary, this work provides new insights into the relationships between bone composition and material properties in
Correlation between the Quantifiable Parameters of Whole Solitary Pulmonary Nodules Perfusion Imaging Derived with Dynamic CT and Nodules Size

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Shiyuan LIU

2009-05-01

Full Text Available Background and objective The solitary pulmonary nodules (SPNs is one of the most common findings on chest radiographs. The blood flow patterns of the biggest single SPNs level has been studied. This assessment may be only a limited sample of the entire region of interest (ROI and is unrepresentative of the SPNs as a volume. Ideally, SPNs volume perfusion should be measured. The aim of this study is to evaluate the correlation between the quantifiableparameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size. Methods Sixty-five patients with SPNs (diameter≤3 cm; 42 malignant; 12 active inflammatory; 11 benign underwent multi-location dynamic contrast material-enhanced serial CT scanning mode with stable table were performed; The mean values of valid sections were calculated, as the quantifiable parameters of volume SPNs perfusion imaging derived with16-slice spiral CT and 64-slice spiral CT. The correlation between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size were assessed by means of linear regression analysis. Results No significant correlations were found between the nodules size and each of the peak height (PHSPN (32.15 Hu±14.55 Hu，ratio of peak height of the SPN to that of the aorta (SPN-to-A ratio(13.20±6.18%, perfusion(PSPN (29.79±19.12 mLmin-1100 g-1 and mean transit time (12.95±6.53 s (r =0.081, P =0.419; r =0.089, P =0.487; r =0.167, P =0.077; r =0.023, P =0.880. Conclusion No significant correlations were found between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size.

Quantifying non-classical and beyond-quantum correlations in the unified operator formalism

International Nuclear Information System (INIS)

Geller, Joshua; Piani, Marco

2014-01-01

Acin et al (2010 Phys. Rev. Lett. 104 140404) introduced a unified framework for the study of no-signalling correlations. Such a framework is based on the notion of local quantum measurements, but, in order to account for beyond-quantum correlations, global pseudo-states that are not positive semidefinite are allowed. After a short review of the formalism, we consider its use in the quantification of both general non-local and beyond-quantum correlations. We argue that the unified framework for correlations provides a simple approach to such a quantification, in particular when the quantification is meant to be operational and meaningful in a resource-theory scenario, i.e., when considering the processing of resources by means of non-resources. We relate different notions of robustness of correlations, both at the level of (pseudo-)states and abstract probability distributions, with particular focus on the beyond-quantum robustness of correlations and pseudo-states. We revisit known results and argue that, within the unified framework, the relation between the two levels—that of operators and that of probability distributions—is very strict. We point out how the consideration of robustness at the two levels leads to a natural framework for the quantification of entanglement in a device-independent way. Finally, we show that the beyond-quantum robustness of the non-positive operators needed to achieve beyond-quantum correlations coincides with their negativity and their distance from the set of quantum states. As an example, we calculate the beyond-quantum robustness for the case of a noisy Popescu–Rohrlich box. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘50 years of Bell’s theorem’. (paper)
Activation of anti-oxidant Nrf2 signaling by enone analogues of curcumin.

Science.gov (United States)

Deck, Lorraine M; Hunsaker, Lucy A; Vander Jagt, Thomas A; Whalen, Lisa J; Royer, Robert E; Vander Jagt, David L

2018-01-01

Inflammation and oxidative stress are common in many chronic diseases. Targeting signaling pathways that contribute to these conditions may have therapeutic potential. The transcription factor Nrf2 is a major regulator of phase II detoxification and anti-oxidant genes as well as anti-inflammatory and neuroprotective genes. Nrf2 is widespread in the CNS and is recognized as an important regulator of brain inflammation. The natural product curcumin exhibits numerous biological activities including ability to induce the expression of Nrf2-dependent phase II and anti-oxidant enzymes. Curcumin has been examined in a number of clinical studies with limited success, mainly owing to limited bioavailability and rapid metabolism. Enone analogues of curcumin were examined with an Nrf2 reporter assay to identify Nrf2 activators. Analogues were separated into groups with a 7-carbon dienone spacer, as found in curcumin; a 5-carbon enone spacer with and without a ring; and a 3-carbon enone spacer. Activators of Nrf2 were found in all three groups, many of which were more active than curcumin. Dose-response studies demonstrated that a range of substituents on the aromatic rings of these enones influenced not only the sensitivity to activation, reflected in EC 50 values, but also the extent of activation, which suggests that multiple mechanisms are involved in the activation of Nrf2 by these analogues. Copyright © 2017. Published by Elsevier Masson SAS.
The Cross-Correlation and Reshuffling Tests in Discerning Induced Seismicity

Science.gov (United States)

Schultz, Ryan; Telesca, Luciano

2018-05-01

In recent years, cases of newly emergent induced clusters have increased seismic hazard and risk in locations with social, environmental, and economic consequence. Thus, the need for a quantitative and robust means to discern induced seismicity has become a critical concern. This paper reviews a Matlab-based algorithm designed to quantify the statistical confidence between two time-series datasets. Similar to prior approaches, our method utilizes the cross-correlation to delineate the strength and lag of correlated signals. In addition, use of surrogate reshuffling tests allows for the dynamic testing against statistical confidence intervals of anticipated spurious correlations. We demonstrate the robust nature of our algorithm in a suite of synthetic tests to determine the limits of accurate signal detection in the presence of noise and sub-sampling. Overall, this routine has considerable merit in terms of delineating the strength of correlated signals, one of which includes the discernment of induced seismicity from natural.
Quantifying uncertainties of climate signals related to the 11-year solar cycle

Science.gov (United States)

Kruschke, T.; Kunze, M.; Matthes, K. B.; Langematz, U.; Wahl, S.

2017-12-01

Although state-of-the-art reconstructions based on proxies and (semi-)empirical models converge in terms of total solar irradiance, they still significantly differ in terms of spectral solar irradiance (SSI) with respect to the mean spectral distribution of energy input and temporal variability. This study aims at quantifying uncertainties for the Earth's climate related to the 11-year solar cycle by forcing two chemistry-climate models (CCMs) - CESM1(WACCM) and EMAC - with five different SSI reconstructions (NRLSSI1, NRLSSI2, SATIRE-T, SATIRE-S, CMIP6-SSI) and the reference spectrum RSSV1-ATLAS3, derived from observations. We conduct a unique set of timeslice experiments. External forcings and boundary conditions are fixed and identical for all experiments, except for the solar forcing. The set of analyzed simulations consists of one solar minimum simulation, employing RSSV1-ATLAS3 and five solar maximum experiments. The latter are a result of adding the amplitude of solar cycle 22 according to the five reconstructions to RSSV1-ATLAS3. Our results show that the climate response to the 11y solar cycle is generally robust across CCMs and SSI forcings. However, analyzing the variance of the solar maximum ensemble by means of ANOVA-statistics reveals additional information on the uncertainties of the mean climate signals. The annual mean response agrees very well between the two CCMs for most parts of the lower and middle atmosphere. Only the upper mesosphere is subject to significant differences related to the choice of the model. However, the different SSI forcings lead to significant differences in ozone concentrations, shortwave heating rates, and temperature throughout large parts of the mesosphere and upper stratosphere. Regarding the seasonal evolution of the climate signals, our findings for short wave heating rates, and temperature are similar to the annual means with respect to the relative importance of the choice of the model or the SSI forcing for the
Removal of artifacts in knee joint vibroarthrographic signals using ensemble empirical mode decomposition and detrended fluctuation analysis

International Nuclear Information System (INIS)

Wu, Yunfeng; Yang, Shanshan; Zheng, Fang; Cai, Suxian; Lu, Meng; Wu, Meihong

2014-01-01

High-resolution knee joint vibroarthrographic (VAG) signals can help physicians accurately evaluate the pathological condition of a degenerative knee joint, in order to prevent unnecessary exploratory surgery. Artifact cancellation is vital to preserve the quality of VAG signals prior to further computer-aided analysis. This paper describes a novel method that effectively utilizes ensemble empirical mode decomposition (EEMD) and detrended fluctuation analysis (DFA) algorithms for the removal of baseline wander and white noise in VAG signal processing. The EEMD method first successively decomposes the raw VAG signal into a set of intrinsic mode functions (IMFs) with fast and low oscillations, until the monotonic baseline wander remains in the last residue. Then, the DFA algorithm is applied to compute the fractal scaling index parameter for each IMF, in order to identify the anti-correlation and the long-range correlation components. Next, the DFA algorithm can be used to identify the anti-correlated and the long-range correlated IMFs, which assists in reconstructing the artifact-reduced VAG signals. Our experimental results showed that the combination of EEMD and DFA algorithms was able to provide averaged signal-to-noise ratio (SNR) values of 20.52 dB (standard deviation: 1.14 dB) and 20.87 dB (standard deviation: 1.89 dB) for 45 normal signals in healthy subjects and 20 pathological signals in symptomatic patients, respectively. The combination of EEMD and DFA algorithms can ameliorate the quality of VAG signals with great SNR improvements over the raw signal, and the results were also superior to those achieved by wavelet matching pursuit decomposition and time-delay neural filter. (paper)
An improved method based on wavelet coefficient correlation to filter noise in Doppler ultrasound blood flow signals

Science.gov (United States)

Wan, Renzhi; Zu, Yunxiao; Shao, Lin

2018-04-01

The blood echo signal maintained through Medical ultrasound Doppler devices would always include vascular wall pulsation signal .The traditional method to de-noise wall signal is using high-pass filter, which will also remove the lowfrequency part of the blood flow signal. Some scholars put forward a method based on region selective reduction, which at first estimates of the wall pulsation signals and then removes the wall signal from the mixed signal. Apparently, this method uses the correlation between wavelet coefficients to distinguish blood signal from wall signal, but in fact it is a kind of wavelet threshold de-noising method, whose effect is not so much ideal. In order to maintain a better effect, this paper proposes an improved method based on wavelet coefficient correlation to separate blood signal and wall signal, and simulates the algorithm by computer to verify its validity.
Photon anti bunching versus phantom anti bunching?

International Nuclear Information System (INIS)

Miranowicz, A.; Ekert, A.; Ekert, A.; Bajer, J.; Leonski, W.

1997-01-01

Photon anti bunching defined by two-time correlation functions has hitherto, to our best knowledge, been considered to constitute a unique, well defined effect. We show explicitly that this is by no means the case. We analyze two of the most famous definitions showing that both anti bunching and bunching effects according to one definition can be accompanied by arbitrary photon correlation effects according to another. As an example we discuss a model of parametric frequency conversion. (authors)
Improved quantification of a commercial enzyme-linked immunosorbent assay kit for measuring anti-MDA5 antibody.

Science.gov (United States)

Gono, Takahisa; Okazaki, Yuka; Murakami, Akihiro; Kuwana, Masataka

2018-04-09

To compare the quantitative performance for measuring anti-MDA5 antibody titer of two enzyme-linked immunosorbent assay (ELISA) systems: an in-house ELISA and the commercial MESACUP TM anti-MDA5 test. Anti-MDA5 antibody titer was measured in sera from 70 patients with dermatomyositis using an in-house ELISA and the MESACUP TM anti-MDA5 test side-by-side. For the commercial ELISA kit, serum samples diluted 1:101 were used according to the manufacturer's protocol, but serial dilutions of sera were also examined to identify the optimal serum dilution for quantification. The anti-MDA5 antibody titers measured by the in-house and commercial ELISAs were positively correlated with each other (r = 0.53, p = .0001), but the antibody titer measured by the commercial ELISA was less sensitive to change after medical treatment, and 37 (80%) of 46 anti-MDA5-positive sera had antibody titer exceeding the quantification range specified by the manufacturer (≥150 index). Experiments using diluted serum samples revealed that diluting the sera 1:5050 improved the quantitative performance of the MESACUP TM anti-MDA5 test, including a better correlation with the in-house ELISA results and an increased sensitivity to change. We improved the ability of the commercial ELISA kit to quantify anti-MDA5 antibody titer by altering its protocol.
Updating signal typing in voice: addition of type 4 signals.

Science.gov (United States)

Sprecher, Alicia; Olszewski, Aleksandra; Jiang, Jack J; Zhang, Yu

2010-06-01

The addition of a fourth type of voice to Titze's voice classification scheme is proposed. This fourth voice type is characterized by primarily stochastic noise behavior and is therefore unsuitable for both perturbation and correlation dimension analysis. Forty voice samples were classified into the proposed four types using narrowband spectrograms. Acoustic, perceptual, and correlation dimension analyses were completed for all voice samples. Perturbation measures tended to increase with voice type. Based on reliability cutoffs, the type 1 and type 2 voices were considered suitable for perturbation analysis. Measures of unreliability were higher for type 3 and 4 voices. Correlation dimension analyses increased significantly with signal type as indicated by a one-way analysis of variance. Notably, correlation dimension analysis could not quantify the type 4 voices. The proposed fourth voice type represents a subset of voices dominated by noise behavior. Current measures capable of evaluating type 4 voices provide only qualitative data (spectrograms, perceptual analysis, and an infinite correlation dimension). Type 4 voices are highly complex and the development of objective measures capable of analyzing these voices remains a topic of future investigation.
Quantifying Short-Chain Chlorinated Paraffin Congener Groups.

Science.gov (United States)

Yuan, Bo; Bogdal, Christian; Berger, Urs; MacLeod, Matthew; Gebbink, Wouter A; Alsberg, Tomas; de Wit, Cynthia A

2017-09-19

Accurate quantification of short-chain chlorinated paraffins (SCCPs) poses an exceptional challenge to analytical chemists. SCCPs are complex mixtures of chlorinated alkanes with variable chain length and chlorination level; congeners with a fixed chain length (n) and number of chlorines (m) are referred to as a "congener group" C n Cl m . Recently, we resolved individual C n Cl m by mathematically deconvolving soft ionization high-resolution mass spectra of SCCP mixtures. Here we extend the method to quantifying C n Cl m by introducing C n Cl m specific response factors (RFs) that are calculated from 17 SCCP chain-length standards with a single carbon chain length and variable chlorination level. The signal pattern of each standard is measured on APCI-QTOF-MS. RFs of each C n Cl m are obtained by pairwise optimization of the normal distribution's fit to the signal patterns of the 17 chain-length standards. The method was verified by quantifying SCCP technical mixtures and spiked environmental samples with accuracies of 82-123% and 76-109%, respectively. The absolute differences between calculated and manufacturer-reported chlorination degrees were -0.9 to 1.0%Cl for SCCP mixtures of 49-71%Cl. The quantification method has been replicated with ECNI magnetic sector MS and ECNI-Q-Orbitrap-MS. C n Cl m concentrations determined with the three instruments were highly correlated (R 2 > 0.90) with each other.
The effects of graded levels of calorie restriction: VI. Impact of short-term graded calorie restriction on transcriptomic responses of the hypothalamic hunger and circadian signaling pathways.

Science.gov (United States)

Derous, Davina; Mitchell, Sharon E; Green, Cara L; Chen, Luonan; Han, Jing-Dong J; Wang, Yingchun; Promislow, Daniel E L; Lusseau, David; Speakman, John R; Douglas, Alex

2016-04-01

Food intake and circadian rhythms are regulated by hypothalamic neuropeptides and circulating hormones, which could mediate the anti-ageing effect of calorie restriction (CR). We tested whether these two signaling pathways mediate CR by quantifying hypothalamic transcripts of male C57BL/6 mice exposed to graded levels of CR (10 % to 40 %) for 3 months. We found that the graded CR manipulation resulted in upregulation of core circadian rhythm genes, which correlated negatively with circulating levels of leptin, insulin-like growth factor 1 (IGF-1), insulin, and tumor necrosis factor alpha (TNF-α). In addition, key components in the hunger signaling pathway were expressed in a manner reflecting elevated hunger at greater levels of restriction, and which also correlated negatively with circulating levels of insulin, TNF-α, leptin and IGF-1. Lastly, phenotypes, such as food anticipatory activity and body temperature, were associated with expression levels of both hunger genes and core clock genes. Our results suggest modulation of the hunger and circadian signaling pathways in response to altered levels of circulating hormones, that are themselves downstream of morphological changes resulting from CR treatment, may be important elements in the response to CR, driving some of the key phenotypic outcomes.
Noise reduction in Lidar signal using correlation-based EMD combined with soft thresholding and roughness penalty

Science.gov (United States)

Chang, Jianhua; Zhu, Lingyan; Li, Hongxu; Xu, Fan; Liu, Binggang; Yang, Zhenbo

2018-01-01

Empirical mode decomposition (EMD) is widely used to analyze the non-linear and non-stationary signals for noise reduction. In this study, a novel EMD-based denoising method, referred to as EMD with soft thresholding and roughness penalty (EMD-STRP), is proposed for the Lidar signal denoising. With the proposed method, the relevant and irrelevant intrinsic mode functions are first distinguished via a correlation coefficient. Then, the soft thresholding technique is applied to the irrelevant modes, and the roughness penalty technique is applied to the relevant modes to extract as much information as possible. The effectiveness of the proposed method was evaluated using three typical signals contaminated by white Gaussian noise. The denoising performance was then compared to the denoising capabilities of other techniques, such as correlation-based EMD partial reconstruction, correlation-based EMD hard thresholding, and wavelet transform. The use of EMD-STRP on the measured Lidar signal resulted in the noise being efficiently suppressed, with an improved signal to noise ratio of 22.25 dB and an extended detection range of 11 km.
Osteoarthritis of the knee: correlation of subchondral MR signal abnormalities with histopathologic and radiographic features

International Nuclear Information System (INIS)

Bergman, A.G.; Willen, H.K.; Lindstrand, A.L.; Pettersson, H.T.A.

1994-01-01

Subchondral signal abnormalities are often present on magnetic resonance (MR) images of patients with osteoarthritis, but no study correlating these changes with histopathology has been published. We selected nine consecutive patients with clinical and radiographic diagnosis of moderate to severe osteoarthritis of the knee scheduled to under go joint replacement surgery, and performed MR imaging and conventional radiographs pre-operatively. After surgery, the resected portions of the femur and tibia underwent gross and microscopic examination, and the findings were correlated with the corresponding findings on the imaging studies. Subchondral MR signal abnormalities of the femur or tibia were present in seven of the nine patients, with intermediate signal on T1-weighted images and low or isointense signal on T2-weighted images. The subchondral signal abnormalities were hemispherical in configuration and corresponded predominantly to fibrous tissue replacing the fatty marrow. A component of trabecular thickening was also present. (orig.)
The anti-aging and anti-oxidation effects of tea water extract in Caenorhabditis elegans.

Science.gov (United States)

Fei, Tianyi; Fei, Jian; Huang, Fang; Xie, Tianpei; Xu, Jifeng; Zhou, Yi; Yang, Ping

2017-10-15

Tea includes puer tea, black tea, green tea and many others. By using model organism Caenorhabditis elegans, the anti-aging and anti-oxidation effects of tea water extract were systemically examined in this study. We found that water extract of puer tea, black tea and green tea all increased the lifespan of worms, postponed Aβ-induced progressive paralysis in Alzheimer's disease transgenic worms, and improved the tolerance of worms to the oxidative stress induced by heavy metal Cr 6+ . Moreover, the anti-oxidation effects of tea water extract at low concentration were different among 4 kinds of brands of green tea. The underlying mechanisms were further explored using genetically manipulated-mutant worms. The anti-oxidative stress effects of green tea water extract depend on the dietary restriction and germline signaling pathways, but not the FOXO and mitochondrial respiratory chain signals. Therefore, tea water extract provides benefits of anti-aging, anti-AD and anti-oxidation. Copyright © 2017. Published by Elsevier Inc.
Using nonlocal coherence to quantify quantum correlation

OpenAIRE

Pei, Pei; Wang, Wei; Li, Chong; Song, He-Shan

2010-01-01

We reexamine quantum correlation from the fundamental perspective of its consanguineous quantum property, the coherence. We emphasize the importance of specifying the tensor product structure of the total state space before discussing quantum correlation. A measure of quantum correlation for arbitrary dimension bipartite states using nonlocal coherence is proposed, and it can be easily generalized to the multipartite case. The quantification of non-entangled component within quantum correlati...
Correlation between imaging findings and autoantibody levels and prognosis in patients with neuropsychiatric systemic lupus erythematosus

International Nuclear Information System (INIS)

Zhou Guangyu; Han Xuemei; Jin Ling

2013-01-01

Objective: To investigate the correlation between cranial magnetic resonance imaging (MRI) findings and autoantibody levels in patients with neuropsychiatric systemic lupus erythematosus (NPSLE), and to elucidate the role of MRI findings in predicting the prognosis of NPSLE. Methods: In total, 36 well-documented cases of NPSLE diagnosed definitely were selected. All the patients were divided into survival group (n=27) and dead group (n=9). Anti-nuclear antibodies and anti-dsDNA antibodies in serum were detected by indirect immunofluorescence and colloidal gold spot penetration method, respectively. Immunoblotting method was used to detect anti-Sm, anti-SSA, anti-SSB, anti U1-RNP, and anti-ribosomal P protein antibodies. Anti-cardiolipin antibody (ACL) was detected byELISA method. The correlation between MRI findings of cerebral lesions and autoantibodies, and prognosis was analyzed. Results: Cranial MRI scans on admission were abnormal in 32 patients (88.9% ), among which 21 cases showed diffuse manifestations, 10 cases showed focal lesion in brain and 1 case showed brain atrophy. The diffuse lesion on MRI showed multiple spotty or patchy normal intensity signal on T 1 -weighted image (T 1 WI) and high-intensity signal changes on T 2 -weighted image (T 2 WI). The focal lesion showed single spotty or patchy normal intensity signal on T 1 WI and high-intensity signal changes on T 2 WI. The lesion sites included basal ganglia, subcortical white matter, anterior and posterior horn of lateral ventricle, semiovale center, cerebral cortex, brainstem and cerebellum. Of 9 patients in dead group, 6 cases presented with focal lesion and the percentage of focal lesion cases in dead group was significantly higher than that in survival group (P<0.01). The percentages of lesion number in brainstem and basal ganglia in dead group were 11.5% and 26.9% , respectively, which were significantly higher than those in survival group (P<0.05 or P<0.01). The positive rate of ACL in cases
A compact clinical instrument for quantifying suppression.

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Black, Joanne M; Thompson, Benjamin; Maehara, Goro; Hess, Robert F

2011-02-01

We describe a compact and convenient clinical apparatus for the measurement of suppression based on a previously reported laboratory-based approach. In addition, we report and validate a novel, rapid psychophysical method for measuring suppression using this apparatus, which makes the technique more applicable to clinical practice. By using a Z800 dual pro head-mounted display driven by a MAC laptop, we provide dichoptic stimulation. Global motion stimuli composed of arrays of moving dots are presented to each eye. One set of dots move in a coherent direction (termed signal) whereas another set of dots move in a random direction (termed noise). To quantify performance, we measure the signal/noise ratio corresponding to a direction-discrimination threshold. Suppression is quantified by assessing the extent to which it matters which eye sees the signal and which eye sees the noise. A space-saving, head-mounted display using current video technology offers an ideal solution for clinical practice. In addition, our optimized psychophysical method provided results that were in agreement with those produced using the original technique. We made measures of suppression on a group of nine adult amblyopic participants using this apparatus with both the original and new psychophysical paradigms. All participants had measurable suppression ranging from mild to severe. The two different psychophysical methods gave a strong correlation for the strength of suppression (rho = -0.83, p = 0.006). Combining the new apparatus and new psychophysical method creates a convenient and rapid technique for parametric measurement of interocular suppression. In addition, this apparatus constitutes the ideal platform for suppressors to combine information between their eyes in a similar way to binocularly normal people. This provides a convenient way for clinicians to implement the newly proposed binocular treatment of amblyopia that is based on antisuppression training.
Experiment to investigate anti ν/sub μ/ → anti ν/sub e/ oscillations at Los Alamos Meson Physics Facility

International Nuclear Information System (INIS)

Kruse, H.W.; Toevs, J.W.

1981-01-01

An experiment, being planned at LAMPF, aims to investigate a possible neutrino oscillation channel, anti ν/sub μ/ → anti ν/sub e/. If anti ν/sub μ/, produced in the LAMPF beam stop, oscillate to anti ν/sub e/, then interactions anti ν/sub e/ + p → e + + n, may be detected. A large volume liquid scintillator (4470 liter) emplaced at 33 m from the beam stop, detects e + and n, after moderation in the hydrogenous liquid and capture in Gd, loaded into the scintillator. Our anticipated signal rate is currently estimated at 1.67 (sigma m 2 ) 2 /day assuming full amplitude oscillation. The corresponding counting rate, assuming all anti ν/sub μ/ have oscillated to anti ν/sub e/ at the detector is 1.5/day. Cosmic rates are estimated at 0.033/day. Correlated backgrounds from the beam stop are calculated to be small in comparison to cosmic events, except for reactions of ν/sub e/ in Pb. These reactions may be reduced with an Fe shield within the detector. With the above rate, a limit on the sensitivity of our experiment for the value of sigma m 2 is estimated at 0.12 eV 2 with 70 days of counting. Detector features, estimated background rates, and sensitivity values are discussed
Photoplethysmogram signal quality estimation using repeated Gaussian filters and cross-correlation

International Nuclear Information System (INIS)

Karlen, W; Kobayashi, K; Dumont, G A; Ansermino, J M

2012-01-01

Pulse oximeters are monitors that noninvasively measure heart rate and blood oxygen saturation (SpO 2 ). Unfortunately, pulse oximetry is prone to artifacts which negatively impact the accuracy of the measurement and can cause a significant number of false alarms. We have developed an algorithm to segment pulse oximetry signals into pulses and estimate the signal quality in real time. The algorithm iteratively calculates a signal quality index (SQI) ranging from 0 to 100. In the presence of artifacts and irregular signal morphology, the algorithm outputs a low SQI number. The pulse segmentation algorithm uses the derivative of the signal to find pulse slopes and an adaptive set of repeated Gaussian filters to select the correct slopes. Cross-correlation of consecutive pulse segments is used to estimate signal quality. Experimental results using two different benchmark data sets showed a good pulse detection rate with a sensitivity of 96.21% and a positive predictive value of 99.22%, which was equivalent to the available reference algorithm. The novel SQI algorithm was effective and produced significantly lower SQI values in the presence of artifacts compared to SQI values during clean signals. The SQI algorithm may help to guide untrained pulse oximeter users and also help in the design of advanced algorithms for generating smart alarms. (paper)
Photoplethysmogram signal quality estimation using repeated Gaussian filters and cross-correlation.

Science.gov (United States)

Karlen, W; Kobayashi, K; Ansermino, J M; Dumont, G A

2012-10-01

Pulse oximeters are monitors that noninvasively measure heart rate and blood oxygen saturation (SpO2). Unfortunately, pulse oximetry is prone to artifacts which negatively impact the accuracy of the measurement and can cause a significant number of false alarms. We have developed an algorithm to segment pulse oximetry signals into pulses and estimate the signal quality in real time. The algorithm iteratively calculates a signal quality index (SQI) ranging from 0 to 100. In the presence of artifacts and irregular signal morphology, the algorithm outputs a low SQI number. The pulse segmentation algorithm uses the derivative of the signal to find pulse slopes and an adaptive set of repeated Gaussian filters to select the correct slopes. Cross-correlation of consecutive pulse segments is used to estimate signal quality. Experimental results using two different benchmark data sets showed a good pulse detection rate with a sensitivity of 96.21% and a positive predictive value of 99.22%, which was equivalent to the available reference algorithm. The novel SQI algorithm was effective and produced significantly lower SQI values in the presence of artifacts compared to SQI values during clean signals. The SQI algorithm may help to guide untrained pulse oximeter users and also help in the design of advanced algorithms for generating smart alarms.

Pro- and anti-apoptotic CD95 signaling in T cells

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Janssen Ottmar

2011-04-01

Full Text Available Abstract The TNF receptor superfamily member CD95 (Fas, APO-1, TNFRSF6 is known as the prototypic death receptor in and outside the immune system. In fact, many mechanisms involved in apoptotic signaling cascades were solved by addressing consequences and pathways initiated by CD95 ligation in activated T cells or other "CD95-sensitive" cell populations. As an example, the binding of the inducible CD95 ligand (CD95L to CD95 on activated T lymphocytes results in apoptotic cell death. This activation-induced cell death was implicated in the control of immune cell homeostasis and immune response termination. Over the past years, however, it became evident that CD95 acts as a dual function receptor that also exerts anti-apoptotic effects depending on the cellular context. Early observations of a potential non-apoptotic role of CD95 in the growth control of resting T cells were recently reconsidered and revealed quite unexpected findings regarding the costimulatory capacity of CD95 for primary T cell activation. It turned out that CD95 engagement modulates TCR/CD3-driven signal initiation in a dose-dependent manner. High doses of immobilized CD95 agonists or cellular CD95L almost completely silence T cells by blocking early TCR-induced signaling events. In contrast, under otherwise unchanged conditions, lower amounts of the same agonists dramatically augment TCR/CD3-driven activation and proliferation. In the present overview, we summarize these recent findings with a focus on the costimulatory capacity of CD95 in primary T cells and discuss potential implications for the T cell compartment and the interplay between T cells and CD95L-expressing cells including antigen-presenting cells.
Quantification of anti-nutritional factors and their correlations with protein and oil in soybeans.

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Bueno, Rafael D; Borges, Leandro L; God, Pedro I V Good; Piovesan, Newton D; Teixeira, Arlindo I; Cruz, Cosme Damião; Barros, Everaldo G DE

2018-01-01

Soybeans contain about 30% carbohydrate, mainly consisting of non-starch polysaccharides (NSP) and oligosaccharides. NSP are not hydrolyzed in the gastrointestinal tract of monogastric animals. These NSP negatively affect the development of these animals, especially the soluble fraction. This work aimed to establish a method to quantify NSP in soybeans, using high performance liquid chromatography (HPLC), and to estimate correlations between NSP, oligosaccharides, protein and oil. Sucrose, raffinose + stachyose, soluble and insoluble NSP contents were determined by HPLC. Oil and protein contents were determined by near-infrared spectroscopy (NIRS). The soluble PNAs content showed no significant correlation with protein, oil, sucrose and raffinose + stachyose contents, but oligosaccharides showed a negative correlation with protein content. These findings open up the possibility of developing cultivars with low soluble NSP content, aiming to develop feed for monogastric animals.
Detrended fluctuation analysis made flexible to detect range of cross-correlated fluctuations

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Kwapień, Jarosław; Oświecimka, Paweł; DroŻdŻ, Stanisław

2015-11-01

The detrended cross-correlation coefficient ρDCCA has recently been proposed to quantify the strength of cross-correlations on different temporal scales in bivariate, nonstationary time series. It is based on the detrended cross-correlation and detrended fluctuation analyses (DCCA and DFA, respectively) and can be viewed as an analog of the Pearson coefficient in the case of the fluctuation analysis. The coefficient ρDCCA works well in many practical situations but by construction its applicability is limited to detection of whether two signals are generally cross-correlated, without the possibility to obtain information on the amplitude of fluctuations that are responsible for those cross-correlations. In order to introduce some related flexibility, here we propose an extension of ρDCCA that exploits the multifractal versions of DFA and DCCA: multifractal detrended fluctuation analysis and multifractal detrended cross-correlation analysis, respectively. The resulting new coefficient ρq not only is able to quantify the strength of correlations but also allows one to identify the range of detrended fluctuation amplitudes that are correlated in two signals under study. We show how the coefficient ρq works in practical situations by applying it to stochastic time series representing processes with long memory: autoregressive and multiplicative ones. Such processes are often used to model signals recorded from complex systems and complex physical phenomena like turbulence, so we are convinced that this new measure can successfully be applied in time-series analysis. In particular, we present an example of such application to highly complex empirical data from financial markets. The present formulation can straightforwardly be extended to multivariate data in terms of the q -dependent counterpart of the correlation matrices and then to the network representation.
The default mode network and the working memory network are not anti-correlated during all phases of a working memory task.

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Piccoli, Tommaso; Valente, Giancarlo; Linden, David E J; Re, Marta; Esposito, Fabrizio; Sack, Alexander T; Di Salle, Francesco

2015-01-01

The default mode network and the working memory network are known to be anti-correlated during sustained cognitive processing, in a load-dependent manner. We hypothesized that functional connectivity among nodes of the two networks could be dynamically modulated by task phases across time. To address the dynamic links between default mode network and the working memory network, we used a delayed visuo-spatial working memory paradigm, which allowed us to separate three different phases of working memory (encoding, maintenance, and retrieval), and analyzed the functional connectivity during each phase within and between the default mode network and the working memory network networks. We found that the two networks are anti-correlated only during the maintenance phase of working memory, i.e. when attention is focused on a memorized stimulus in the absence of external input. Conversely, during the encoding and retrieval phases, when the external stimulation is present, the default mode network is positively coupled with the working memory network, suggesting the existence of a dynamically switching of functional connectivity between "task-positive" and "task-negative" brain networks. Our results demonstrate that the well-established dichotomy of the human brain (anti-correlated networks during rest and balanced activation-deactivation during cognition) has a more nuanced organization than previously thought and engages in different patterns of correlation and anti-correlation during specific sub-phases of a cognitive task. This nuanced organization reinforces the hypothesis of a direct involvement of the default mode network in cognitive functions, as represented by a dynamic rather than static interaction with specific task-positive networks, such as the working memory network.
Scandoside Exerts Anti-Inflammatory Effect Via Suppressing NF-κB and MAPK Signaling Pathways in LPS-Induced RAW 264.7 Macrophages

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Jingyu He

2018-02-01

Full Text Available The iridoids of Hedyotis diffusa Willd play an important role in the anti-inflammatory process, but the specific iridoid with anti-inflammatory effect and its mechanism has not be thoroughly studied. An iridoid compound named scandoside (SCA was isolated from H. diffusa and its anti-inflammatory effect was investigated in lipopolysaccharide (LPS-induced RAW 264.7 macrophages. Its anti-inflammatory mechanism was confirmed by in intro experiments and molecular docking analyses. As results, SCA significantly decreased the productions of nitric oxide (NO, prostaglandin E2 (PGE2, tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6 and inhibited the levels of inducible nitric oxide synthase (iNOS, cyclooxygenase-2 (COX-2, TNF-α and IL-6 messenger RNA (mRNA expression in LPS-induced RAW 264.7 macrophages. SCA treatment suppressed the phosphorylation of inhibitor of nuclear transcription factor kappa-B alpaha (IκB-α, p38, extracellular signal-regulated kinase (ERK and c-Jun N-terminal kinase (JNK. The docking data suggested that SCA had great binding abilities to COX-2, iNOS and IκB. Taken together, the results indicated that the anti-inflammatory effect of SCA is due to inhibition of pro-inflammatory cytokines and mediators via suppressing the nuclear transcription factor kappa-B (NF-κB and mitogen-activated protein kinase (MAPK signaling pathways, which provided useful information for its application and development.
Task effects on BOLD signal correlates of implicit syntactic processing

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Caplan, David

2010-01-01

BOLD signal was measured in sixteen participants who made timed font change detection judgments in visually presented sentences that varied in syntactic structure and the order of animate and inanimate nouns. Behavioral data indicated that sentences were processed to the level of syntactic structure. BOLD signal increased in visual association areas bilaterally and left supramarginal gyrus in the contrast of sentences with object- and subject-extracted relative clauses without font changes in which the animacy order of the nouns biased against the syntactically determined meaning of the sentence. This result differs from the findings in a non-word detection task (Caplan et al, 2008a), in which the same contrast led to increased BOLD signal in the left inferior frontal gyrus. The difference in areas of activation indicates that the sentences were processed differently in the two tasks. These differences were further explored in an eye tracking study using the materials in the two tasks. Issues pertaining to how parsing and interpretive operations are affected by a task that is being performed, and how this might affect BOLD signal correlates of syntactic contrasts, are discussed. PMID:20671983
PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of posttraumatic epilepsy

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Berdichevsky, Yevgeny; Dryer, Alexandra M.; Saponjian, Yero; Mahoney, Mark M.; Pimentel, Corrin A.; Lucini, Corrina A.; Usenovic, Marija; Staley, Kevin J.

2013-01-01

mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an antiepileptogenic, or merely anti-convulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordings, and cell death was quantified with LDH release measurements and Nissl-stained neuron counts. Lactate and LDH measurements were well-correlated with electrographic activity and neuron counts, respectively. Inhibition of PI3K and Akt prevented activation of mTOR, and was as effective as inhibition of mTOR in reducing ictal activity and cell death. A dual inhibitor of PI3K and mTOR, NVP-BEZ235, was also effective. Inhibition of mTOR with rapamycin reduced axon sprouting. Late start of rapamycin treatment was effective in reducing epileptic activity and cell death, while early termination of rapamycin treatment did not result in increased epileptic activity or cell death. The conclusions of the study are: (1), the organotypic hippocampal culture model of posttraumatic epilepsy comprises a rapid assay of antiepileptogenic and neuroprotective activities and, in this model (2), mTOR activation depends on PI3K-Akt signaling, and (3) transient inhibition of mTOR has sustained effects on epilepsy. PMID:23699517
The role of circulating anti-p53 antibodies in patients with advanced non-small cell lung cancer and their correlation to clinical parameters and survival

International Nuclear Information System (INIS)

Bergqvist, Michael; Brattström, Daniel; Larsson, Anders; Hesselius, Patrik; Brodin, Ola; Wagenius, Gunnar

2004-01-01

Lung cancer causes approximately one million deaths each year worldwide and protein p53 has been shown to be involved in the intricate processes regulating response to radiation and/or chemotherapeutic treatment. Consequently, since antibodies against p53 (anti-p53 antibodies) are associated with mutations within the p53 gene it seems likely that these antibodies could, hypothetically, be correlated with prognosis. Serum samples from patients with non-small cell lung cancer (NSCLC) admitted to the Department of Oncology, University Hospital, Uppsala, Sweden, during 1983–1996 were studied. Anti-p53 abs were measured using a sandwich ELISA (Dianova, Hamburg, Germany). The present study included 84 patients with stage IIIA-IV (advanced NSCLC). At least three serum samples from each patient were collected and altogether 529 serum samples were analysed for the presence of anti-p53 antibodies. The median value of anti-p53 antibodies was 0.06 (range 0 – 139.8). Seventeen percent of investigated NSCLC first serum samples (n = 84) expressed elevated levels of anti-p53 antibodies. Anti-p53 antibodies were not correlated to tumour volume or platelets. Survival analysis showed that anti-p53 antibodies were not associated with survival as revealed by univariate analysis (p = 0.29). However, patients with adenocarcinoma had a significantly poorer survival if they expressed anti-p53 antibodies (p = 0.01), whereas this was not found for patients with squamous cell carcinoma (p = 0.13). In patients where the blood samples were collected during radiation therapy, a statistically significant correlation towards poorer survival was found (p = 0.05) when elevated anti-p53 antibodies levels were present. No correlations to survival were found for serum samples collected prior to radiation therapy, during chemotherapy, or during follow-up. When anti-p53 antibodies were measured continuously, no increase in median anti-p53 values was observed the closer the individual patient come to
Acupuncture mobilizes the brain's default mode and its anti-correlated network in healthy subjects.

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Hui, Kathleen K S; Marina, Ovidiu; Claunch, Joshua D; Nixon, Erika E; Fang, Jiliang; Liu, Jing; Li, Ming; Napadow, Vitaly; Vangel, Mark; Makris, Nikos; Chan, Suk-Tak; Kwong, Kenneth K; Rosen, Bruce R

2009-09-01

Previous work has shown that acupuncture stimulation evokes deactivation of a limbic-paralimbic-neocortical network (LPNN) as well as activation of somatosensory brain regions. This study explores the activity and functional connectivity of these regions during acupuncture vs. tactile stimulation and vs. acupuncture associated with inadvertent sharp pain. Acupuncture during 201 scans and tactile stimulation during 74 scans for comparison at acupoints LI4, ST36 and LV3 was monitored with fMRI and psychophysical response in 48 healthy subjects. Clusters of deactivated regions in the medial prefrontal, medial parietal and medial temporal lobes as well as activated regions in the sensorimotor and a few paralimbic structures can be identified during acupuncture by general linear model analysis and seed-based cross correlation analysis. Importantly, these clusters showed virtual identity with the default mode network and the anti-correlated task-positive network in response to stimulation. In addition, the amygdala and hypothalamus, structures not routinely reported in the default mode literature, were frequently involved in acupuncture. When acupuncture induced sharp pain, the deactivation was attenuated or became activated instead. Tactile stimulation induced greater activation of the somatosensory regions but less extensive deactivation of the LPNN. These results indicate that the deactivation of the LPNN during acupuncture cannot be completely explained by the demand of attention that is commonly proposed in the default mode literature. Our results suggest that acupuncture mobilizes the anti-correlated functional networks of the brain to mediate its actions, and that the effect is dependent on the psychophysical response.
Halofuginone has anti-proliferative effects in acute promyelocytic leukemia by modulating the transforming growth factor beta signaling pathway.

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Lorena L de Figueiredo-Pontes

Full Text Available Promyelocytic leukemia-retinoic acid receptor alpha (PML-RARα expression in acute promyelocytic leukemia (APL impairs transforming growth factor beta (TGFβ signaling, leading to cell growth advantage. Halofuginone (HF, a low-molecular-weight alkaloid that modulates TGFβ signaling, was used to treat APL cell lines and non-obese diabetic/severe combined immunodeficiency (NOD/SCID mice subjected to transplantation with leukemic cells from human chorionic gonadotrophin-PML-RARα transgenic mice (TG. Cell cycle analysis using incorporated bromodeoxyuridine and 7-amino-actinomycin D showed that, in NB4 and NB4-R2 APL cell lines, HF inhibited cellular proliferation (P<0.001 and induced apoptosis (P = 0.002 after a 24-hour incubation. Addition of TGFβ revealed that NB4 cells were resistant to its growth-suppressive effects and that HF induced these effects in the presence or absence of the cytokine. Cell growth inhibition was associated with up-regulation of TGFβ target genes involved in cell cycle regulation (TGFB, TGFBRI, SMAD3, p15, and p21 and down-regulation of MYC. Additionally, TGFβ protein levels were decreased in leukemic TG animals and HF in vivo could restore TGFβ values to normal. To test the in vivo anti-leukemic activity of HF, we transplanted NOD/SCID mice with TG leukemic cells and treated them with HF for 21 days. HF induced partial hematological remission in the peripheral blood, bone marrow, and spleen. Together, these results suggest that HF has anti-proliferative and anti-leukemic effects by reversing the TGFβ blockade in APL. Since loss of the TGFβ response in leukemic cells may be an important second oncogenic hit, modulation of TGFβ signaling may be of therapeutic interest.
Non-linear canonical correlation for joint analysis of MEG signals from two subjects

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Cristina eCampi

2013-06-01

Full Text Available We consider the problem of analysing magnetoencephalography (MEG data measured from two persons undergoing the same experiment, and we propose a method that searches for sources with maximally correlated energies. Our method is based on canonical correlation analysis (CCA, which provides linear transformations, one for each subject, such that the correlation between the transformed MEG signals is maximized. Here, we present a nonlinear version of CCA which measures the correlation of energies. Furthermore, we introduce a delay parameter in the modelto analyse, e.g., leader-follower changes in experiments where the two subjects are engaged in social interaction.
Quantification of anti-nutritional factors and their correlations with protein and oil in soybeans

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RAFAEL D. BUENO

Full Text Available ABSTRACT Soybeans contain about 30% carbohydrate, mainly consisting of non-starch polysaccharides (NSP and oligosaccharides. NSP are not hydrolyzed in the gastrointestinal tract of monogastric animals. These NSP negatively affect the development of these animals, especially the soluble fraction. This work aimed to establish a method to quantify NSP in soybeans, using high performance liquid chromatography (HPLC, and to estimate correlations between NSP, oligosaccharides, protein and oil. Sucrose, raffinose + stachyose, soluble and insoluble NSP contents were determined by HPLC. Oil and protein contents were determined by near-infrared spectroscopy (NIRS. The soluble PNAs content showed no significant correlation with protein, oil, sucrose and raffinose + stachyose contents, but oligosaccharides showed a negative correlation with protein content. These findings open up the possibility of developing cultivars with low soluble NSP content, aiming to develop feed for monogastric animals.
Analysis of cross-correlations in electroencephalogram signals as an approach to proactive diagnosis of schizophrenia

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Timashev, Serge F.; Panischev, Oleg Yu.; Polyakov, Yuriy S.; Demin, Sergey A.; Kaplan, Alexander Ya.

2012-02-01

We apply flicker-noise spectroscopy (FNS), a time series analysis method operating on structure functions and power spectrum estimates, to study the clinical electroencephalogram (EEG) signals recorded in children/adolescents (11 to 14 years of age) with diagnosed schizophrenia-spectrum symptoms at the National Center for Psychiatric Health (NCPH) of the Russian Academy of Medical Sciences. The EEG signals for these subjects were compared with the signals for a control sample of chronically depressed children/adolescents. The purpose of the study is to look for diagnostic signs of subjects' susceptibility to schizophrenia in the FNS parameters for specific electrodes and cross-correlations between the signals simultaneously measured at different points on the scalp. Our analysis of EEG signals from scalp-mounted electrodes at locations F3 and F4, which are symmetrically positioned in the left and right frontal areas of cerebral cortex, respectively, demonstrates an essential role of frequency-phase synchronization, a phenomenon representing specific correlations between the characteristic frequencies and phases of excitations in the brain. We introduce quantitative measures of frequency-phase synchronization and systematize the values of FNS parameters for the EEG data. The comparison of our results with the medical diagnoses for 84 subjects performed at NCPH makes it possible to group the EEG signals into 4 categories corresponding to different risk levels of subjects' susceptibility to schizophrenia. We suggest that the introduced quantitative characteristics and classification of cross-correlations may be used for the diagnosis of schizophrenia at the early stages of its development.
A Saccharomyces cerevisiae assay system to investigate ligand/AdipoR1 interactions that lead to cellular signaling.

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Mustapha Aouida

Full Text Available Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used to study both AdipoRs separately. Agonist-AdipoR1 interactions are detected using a split firefly luciferase assay based on reconstitution of firefly luciferase (Luc activity due to juxtaposition of its N- and C-terminal fragments, NLuc and CLuc, by ligand induced interaction of the chimeric proteins CLuc-AdipoR1 and APPL1-NLuc (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif 1-NLuc in a S. cerevisiae strain lacking the yeast homolog of AdipoRs (Izh2p. The assay monitors the earliest known step in the adiponectin-AdipoR anti-diabetic signaling cascade. We demonstrate that reconstituted Luc activity can be detected in colonies or cells using a CCD camera and quantified in cell suspensions using a microplate reader. AdipoR1-APPL1 interaction occurs in absence of ligand but can be stimulated specifically by agonists such as adiponectin and the tobacco protein osmotin that was shown to have AdipoR-dependent adiponectin-like biological activity in mammalian cells. To further validate this assay, we have modeled the three dimensional structures of receptor-ligand complexes of membrane-embedded AdipoR1 with cyclic peptides derived from osmotin or osmotin-like plant proteins. We demonstrate that the calculated AdipoR1-peptide binding energies correlate with the peptides' ability to behave as AdipoR1 agonists in the split luciferase assay. Further, we demonstrate agonist-AdipoR dependent activation of protein kinase A (PKA signaling and AMP activated protein kinase (AMPK phosphorylation in S. cerevisiae, which are
Correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size

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Chenshi ZHANG

2008-02-01

Full Text Available Background and Objective The solitary pulmonary nodules (SPNs is one of the most common findings on chest radiographs. It becomes possible to provide more accurately quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs with multi-slice spiral computed tomography (MSCT. The aim of this study is to evaluate the correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size. Methods 68 patients with maliagnant solitary pulmonary nodules (SPNs (diameter <=4 cmunderwent multi-location dynamic contrast material-enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4mL/s by an autoinjector, 4*5mm or 4*2.5mm scanning mode with stable table were performed. serial CT. Precontrast and postcontrast attenuation on every scan was recorded. Perfusion (PSPN, peak height (PHSPNratio of peak height of the SPN to that of the aorta (SPN-to-A ratioand mean transit time(MTT were calculated. The correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size were assessed by means of linear regression analysis. Results No significant correlations were found between the tumor size and each of the peak height (PHSPN ratio of peak height of the SPN to that of the aorta (SPN-to-A ratio perfusion(PSPNand mean transit time (r=0.18, P=0.14; r=0.20,P=0.09; r=0.01, P=0.95; r=0.01, P=0.93. Conclusion No significant correlation is found between the tumor size and each of the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules.
Detection of non-stationary leak signals at NPP primary circuit by cross-correlation analysis

International Nuclear Information System (INIS)

Shimanskij, S.B.

2007-01-01

A leak-detection system employing high-temperature microphones has been developed for the RBMK and ATR (Japan) reactors. Further improvement of the system focused on using cross-correlation analysis of the spectral components of the signal to detect a small leak at an early stage of development. Since envelope processes are less affected by distortions than are wave processes, they give a higher-degree of correlation and can be used to detect leaks with lower signal-noise ratios. Many simulation tests performed at nuclear power plants have shown that the proposed methods can be used to detect and find the location of a small leak [ru
The correlation of serum asymmetric dimethylarginine and anti-Müllerian hormone in primary dysmenorrhea

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Nermin Akdemir

2016-08-01

Full Text Available In this study, we aimed to investigate the association of serum asymmetric dimethylarginine (ADMA and anti-Müllerian hormone (AMH levels in primary dysmenorrhea patients. The study employed a cross-sectional design. Eighty-nine female university students with primary dysmenorrhea were included in the study. All patients underwent complete clinical and laboratory investigations, including serum ADMA, AMH levels, pelvic ultrasonography, electrocardiography, and echocardiography. Pearson correlation and linear regression analysis were used to evaluate associations between continuous data. Categorical associations were evaluated using χ2 test. Correlation analysis between serum ADMA and AMH levels in the study group showed a highly significant positive relationship (Pearson correlation = 0.978, p = 0.01. Our study has shown a significant positive correlation between serum ADMA and AMH levels in primary dysmenorrhea. Serum ADMA levels may have the potential to demonstrate ovarian reserve.
Correlation of non-mass-like abnormal MR signal intensity with pathological findings surrounding pediatric osteosarcoma and Ewing's sarcoma

International Nuclear Information System (INIS)

Masrouha, Karim Z.; Haidar, Rachid; Saghieh, Said; Musallam, Khaled M.; Samra, Alexis Bou; Tawil, Ayman; Chakhachiro, Zaher; Abdallah, Abeer; Khoury, Nabil J.; Saab, Raya; Muwakkit, Samar; Abboud, Miguel R.

2012-01-01

The aim of this work was to determine the role of MRI in interpreting abnormal signals within bones and soft tissues adjacent to tumor bulk of osteosarcoma and Ewing's sarcoma in a pediatric population by correlating MR findings with histopathology. Thirty patients met the inclusion criteria, which included (1) osteosarcoma or Ewing's sarcoma, (2) MR studies no more than 2 months prior to surgery, (3) presence of abnormal MR signal surrounding the tumor bulk, (4) pathological material from resected tumor. The patients received standard neoadjuvant chemotherapy. Using grid maps on gross pathology specimens, the abnormal MR areas around the tumor were matched with the corresponding grid sections. Histopathology slides of these sections were then analyzed to determine the nature of the regions of interest. The MR/pathological correlation was evaluated using Mann-Whitney U test and Fisher's exact test. Twenty-seven patients had osteosarcoma and three patients had Ewing's sarcoma. Of the studied areas, 17.4% were positive for tumor (viable or necrotic). There was no statistically significant correlation between areas positive for tumor and age, gender, signal extent and intensity on MRI, or tissue type. There was, however, a statistically significant correlation between presence of tumor and the appearance of abnormal soft tissue signals. A feathery appearance correlated with tumor-negative areas whereas a bulky appearance correlated with tumor-positive regions. MR imaging is helpful in identifying the nature of abnormal signal areas surrounding bone sarcomas that are more likely to be tumor-free, particularly when the signal in the soft tissues surrounding the tumor is feathery and edema-like in appearance. (orig.)
Evolution of anti-Trypanosoma cruzi antibody production in patients with chronic Chagas disease: Correlation between antibody titers and development of cardiac disease severity.

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Ingebourg Georg

2017-07-01

Full Text Available Chagas disease is one of the most important endemic infections in Latin America affecting around 6-7 million people. About 30-50% of patients develop the cardiac form of the disease, which can lead to severe cardiac dysfunction and death. In this scenario, the identification of immunological markers of disease progression would be a valuable tool for early treatment and reduction of death rates. In this observational study, the production of anti-Trypanosoma cruzi antibodies through a retrospective longitudinal follow-up in chronic Chagas disease patients´ cohort and its correlation with disease progression and heart commitment was evaluated. Strong inverse correlation (ρ = -0.6375, p = 0.0005 between anti-T. cruzi IgG1 titers and left ventricular ejection fraction (LVEF in chronic Chagas cardiomyopathy (CCC patients were observed after disease progression. Elevated levels of anti-T. cruzi IgG3 titers were detected in all T. cruzi-infected patients, indicating a lack of correlation of this IgG isotype with disease progression. Furthermore, low levels of anti-T. cruzi IgG2, IgG4, and IgA were detected in all patients through the follow-up. Although without statistical significance anti-T. cruzi IgE tends to be more reactive in patients with the indeterminate form (IND of the disease (p = 0.0637. As this study was conducted in patients with many years of chronic disease no anti-T. cruzi IgM was detected. Taken together, these results indicate that the levels of anti-T. cruzi IgG1 could be considered to seek for promising biomarkers to predict the severity of chronic Chagas disease cardiomyopathy.
Muscle MRI STIR signal intensity and atrophy are correlated to focal lower limb neuropathy severity.

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Deroide, N; Bousson, V; Mambre, L; Vicaut, E; Laredo, J D; Kubis, Nathalie

2015-03-01

The objective is to determine if muscle MRI is useful for assessing neuropathy severity. Clinical, MRI and electromyography (EMG) examinations were performed in 17 patients with focal lower limb neuropathies. MRI Short Tau Inversion Recovery (STIR) signal intensity, amyotrophy, and muscle fatty infiltration measured after T1-weighted image acquisition, EMG spontaneous activity (SA), and maximal voluntary contraction (MVC) were graded using semiquantitative scores and quantitative scores for STIR signal intensity and were correlated to the Medical Research Council (MRC) score for testing muscle strength. Within this population, subgroups were selected according to severity (mild versus severe), duration (subacute versus chronic), and topography (distal versus proximal) of the neuropathy. EMG SA and MVC MRI amyotrophy and quantitative scoring of muscle STIR intensity were correlated with the MRC score. Moreover, MRI amyotrophy was significantly increased in severe, chronic, and proximal neuropathies along with fatty infiltration in chronic lesions. Muscle MRI atrophy and quantitative evaluation of signal intensity were correlated to MRC score in our study. Semiquantitative evaluation of muscle STIR signal was sensitive enough for detection of topography of the nerve lesion but was not suitable to assess severity. Muscle MRI could support EMG in chronic and proximal neuropathy, which showed poor sensitivity in these patients.

Muscle MRI STIR signal intensity and atrophy are correlated to focal lower limb neuropathy severity

Energy Technology Data Exchange (ETDEWEB)

Deroide, N.; Mambre, L.; Kubis, Nathalie [Service de Physiologie Clinique-Explorations Fonctionnelles, AP-HP, Hopital Lariboisiere, Paris (France); Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); Bousson, V.; Laredo, J.D. [Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); Radiologie Osteo-articulaire, AP-HP, Hopital Lariboisiere, Paris (France); Vicaut, E. [Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); URC, AP-HP, Hopital Lariboisiere, Paris (France)

2014-09-26

The objective is to determine if muscle MRI is useful for assessing neuropathy severity. Clinical, MRI and electromyography (EMG) examinations were performed in 17 patients with focal lower limb neuropathies. MRI Short Tau Inversion Recovery (STIR) signal intensity, amyotrophy, and muscle fatty infiltration measured after T1-weighted image acquisition, EMG spontaneous activity (SA), and maximal voluntary contraction (MVC) were graded using semiquantitative scores and quantitative scores for STIR signal intensity and were correlated to the Medical Research Council (MRC) score for testing muscle strength. Within this population, subgroups were selected according to severity (mild versus severe), duration (subacute versus chronic), and topography (distal versus proximal) of the neuropathy. EMG SA and MVC MRI amyotrophy and quantitative scoring of muscle STIR intensity were correlated with the MRC score. Moreover, MRI amyotrophy was significantly increased in severe, chronic, and proximal neuropathies along with fatty infiltration in chronic lesions. Muscle MRI atrophy and quantitative evaluation of signal intensity were correlated to MRC score in our study. Semiquantitative evaluation of muscle STIR signal was sensitive enough for detection of topography of the nerve lesion but was not suitable to assess severity. Muscle MRI could support EMG in chronic and proximal neuropathy, which showed poor sensitivity in these patients. (orig.)
Multiplicities and forward-backward correlations in anti pp interactions at 22.4 GeV/c

International Nuclear Information System (INIS)

Boos, E.G.; Samojlov, V.V.; Tashimov, M.A.

1977-01-01

Forward-backward multiplicity correlations in anti pp -interactions at 22.4 GeV/c and multiplicities in a simple icle multiplicity distribution is divided into even and odd components, the probability of producting an odd state is found to be higher than that of producing an even state, which may be interpreted to be due to diffraction forward-backward and to everall multiplicities is discussed
Development and Validation of a Novel Dual Luciferase Reporter Gene Assay to Quantify Ebola Virus VP24 Inhibition of IFN Signaling

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Elisa Fanunza

2018-02-01

Full Text Available The interferon (IFN system is the first line of defense against viral infections. Evasion of IFN signaling by Ebola viral protein 24 (VP24 is a critical event in the pathogenesis of the infection and, hence, VP24 is a potential target for drug development. Since no drugs target VP24, the identification of molecules able to inhibit VP24, restoring and possibly enhancing the IFN response, is a goal of concern. Accordingly, we developed a dual signal firefly and Renilla luciferase cell-based drug screening assay able to quantify IFN-mediated induction of Interferon Stimulated Genes (ISGs and its inhibition by VP24. Human Embryonic Kidney 293T (HEK293T cells were transiently transfected with a luciferase reporter gene construct driven by the promoter of ISGs, Interferon-Stimulated Response Element (ISRE. Stimulation of cells with IFN-α activated the IFN cascade leading to the expression of ISRE. Cotransfection of cells with a plasmid expressing VP24 cloned from a virus isolated during the last 2014 outbreak led to the inhibition of ISRE transcription, quantified by a luminescent signal. To adapt this system to test a large number of compounds, we performed it in 96-well plates; optimized the assay analyzing different parameters; and validated the system by calculating the Z′- and Z-factor, which showed values of 0.62 and 0.53 for IFN-α stimulation assay and VP24 inhibition assay, respectively, indicative of robust assay performance.
Histologic correlation of MR signal intensity in parathyroid adenomas

International Nuclear Information System (INIS)

Rumancik, W.M.; Khan, A.; Mir, R.N.; Attie, J.N.; Davis, J.E.; Ashtari, M.; Herman, P.G.

1988-01-01

The classic MR signal intensity pattern of parathyroid adenoma (PTA) is bright enhancement on T2-weighted images. However, variations in SI pattern have been observed in clinical practice. The purpose of this report is to describe the histologic characteristics of surgically removed PTAs as correlated with their in vivo MR imaging appearance. From May 1987 to April 1988, 51 consecutive patients with primary hyperparathyroidism were evaluated with MR imaging for preoperative localization of PTA. Surgical confirmation was obtained in all patients, with histologic evaluation available in 40. MR imaging was performed on 1.0-T system (Siemens, Magnetom) using a Helmhotz surface coil positioned at the neck. Spin-echo T1-weighted and T2-weighted multisection images were evaluated retrospectively. Signal intensities of PTA, adjacent thyroid, fat, and skeletal muscle were obtained (1) from direct region of interest determinations, and (2) visually as respective relationships of PTA to thyroid, fat, and muscle. Histologic classification was graded for (1) predominant cell type (i.e., chief or oxyphil cells), (2) acinar or solid growth pattern, (3) cystic change, (4) presence or absence of residual fat, (5) cell count per high power field, (6) heterogeneous histology, (7) gland weight, and (8) giant size (≥3 cm). The relationship of MR signal intensity to histology appears multifactorial
Quantum-correlated two-photon transitions to excitons in semiconductor quantum wells.

Science.gov (United States)

Salazar, L J; Guzmán, D A; Rodríguez, F J; Quiroga, L

2012-02-13

The dependence of the excitonic two-photon absorption on the quantum correlations (entanglement) of exciting biphotons by a semiconductor quantum well is studied. We show that entangled photon absorption can display very unusual features depending on space-time-polarization biphoton parameters and absorber density of states for both bound exciton states as well as for unbound electron-hole pairs. We report on the connection between biphoton entanglement, as quantified by the Schmidt number, and absorption by a semiconductor quantum well. Comparison between frequency-anti-correlated, unentangled and frequency-correlated biphoton absorption is addressed. We found that exciton oscillator strengths are highly increased when photons arrive almost simultaneously in an entangled state. Two-photon-absorption becomes a highly sensitive probe of photon quantum correlations when narrow semiconductor quantum wells are used as two-photon absorbers.
Developmental changes of BOLD signal correlations with global human EEG power and synchronization during working memory.

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Lars Michels

Full Text Available In humans, theta band (5-7 Hz power typically increases when performing cognitively demanding working memory (WM tasks, and simultaneous EEG-fMRI recordings have revealed an inverse relationship between theta power and the BOLD (blood oxygen level dependent signal in the default mode network during WM. However, synchronization also plays a fundamental role in cognitive processing, and the level of theta and higher frequency band synchronization is modulated during WM. Yet, little is known about the link between BOLD, EEG power, and EEG synchronization during WM, and how these measures develop with human brain maturation or relate to behavioral changes. We examined EEG-BOLD signal correlations from 18 young adults and 15 school-aged children for age-dependent effects during a load-modulated Sternberg WM task. Frontal load (in-dependent EEG theta power was significantly enhanced in children compared to adults, while adults showed stronger fMRI load effects. Children demonstrated a stronger negative correlation between global theta power and the BOLD signal in the default mode network relative to adults. Therefore, we conclude that theta power mediates the suppression of a task-irrelevant network. We further conclude that children suppress this network even more than adults, probably from an increased level of task-preparedness to compensate for not fully mature cognitive functions, reflected in lower response accuracy and increased reaction time. In contrast to power, correlations between instantaneous theta global field synchronization and the BOLD signal were exclusively positive in both age groups but only significant in adults in the frontal-parietal and posterior cingulate cortices. Furthermore, theta synchronization was weaker in children and was--in contrast to EEG power--positively correlated with response accuracy in both age groups. In summary we conclude that theta EEG-BOLD signal correlations differ between spectral power and
Ocular manifestations of rheumatoid arthritis and their correlation with anti-cyclic citrullinated peptide antibodies

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Vignesh AP

2015-02-01

Full Text Available Ammapati Paul Pandian Vignesh, Renuka Srinivasan Department of Ophthalmology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India Purpose: To study the ocular manifestations of rheumatoid arthritis and to correlate the role of anti-cyclic citrullinated peptide antibody (anti-CCP antibody with the ocular manifestations.Methods: Three-hundred and ninety-two eyes of the 196 rheumatoid arthritis patients who attended the ophthalmology outpatient department underwent a detailed ocular examination using slit lamp biomicroscopy and ophthalmoscopy. The tear function of all the patients was assessed using Schirmer’s test, tear film break-up time and ocular surface staining. The anti-CCP antibody titers for all the rheumatoid arthritis patients were estimated using enzyme-linked immunosorbent assay tests.Results: Seventy-seven patients (135 eyes, 39% out of the 196 patients studied had ocular manifestations typical of rheumatoid arthritis. Dry eye was the most common manifestation (28%, 54 patients. Of the patients, 78% was females (60 patients. The mean duration of rheumatoid arthritis in patients with ocular manifestations was 5.4±2.7 years and without ocular manifestations was 2.1±1.6years. Three percent of the patients had episcleritis (six patients. Scleritis was present in 2% of the patients (four patients. Peripheral ulcerative keratitis and sclerosing keratitis was present in 1% of the population each (two patients each. Eighty-five percent (66 patients had bilateral manifestations 15% (eleven patients had unilateral manifestations. There was a strong association between the presence of anti-CCP antibodies and ocular manifestations of rheumatoid arthritis which was shown by the statistically significant P-value of <0.0001.Conclusion: Ocular manifestations are a significant part of the extra-articular manifestation of rheumatoid arthritis. Dry eye was the most common ocular manifestation. There was a
Electrophysiological correlates of the BOLD signal for EEG-informed fMRI

Science.gov (United States)

Murta, Teresa; Leite, Marco; Carmichael, David W; Figueiredo, Patrícia; Lemieux, Louis

2015-01-01

Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are important tools in cognitive and clinical neuroscience. Combined EEG–fMRI has been shown to help to characterise brain networks involved in epileptic activity, as well as in different sensory, motor and cognitive functions. A good understanding of the electrophysiological correlates of the blood oxygen level-dependent (BOLD) signal is necessary to interpret fMRI maps, particularly when obtained in combination with EEG. We review the current understanding of electrophysiological–haemodynamic correlates, during different types of brain activity. We start by describing the basic mechanisms underlying EEG and BOLD signals and proceed by reviewing EEG-informed fMRI studies using fMRI to map specific EEG phenomena over the entire brain (EEG–fMRI mapping), or exploring a range of EEG-derived quantities to determine which best explain colocalised BOLD fluctuations (local EEG–fMRI coupling). While reviewing studies of different forms of brain activity (epileptic and nonepileptic spontaneous activity; cognitive, sensory and motor functions), a significant attention is given to epilepsy because the investigation of its haemodynamic correlates is the most common application of EEG-informed fMRI. Our review is focused on EEG-informed fMRI, an asymmetric approach of data integration. We give special attention to the invasiveness of electrophysiological measurements and the simultaneity of multimodal acquisitions because these methodological aspects determine the nature of the conclusions that can be drawn from EEG-informed fMRI studies. We emphasise the advantages of, and need for, simultaneous intracranial EEG–fMRI studies in humans, which recently became available and hold great potential to improve our understanding of the electrophysiological correlates of BOLD fluctuations. PMID:25277370
Histopathologic correlation of magnetic resonance imaging signal patterns in a spinal cord injury model.

Science.gov (United States)

Weirich, S D; Cotler, H B; Narayana, P A; Hazle, J D; Jackson, E F; Coupe, K J; McDonald, C L; Langford, L A; Harris, J H

1990-07-01

Magnetic resonance imaging (MRI) provides a noninvasive method of monitoring the pathologic response to spinal cord injury. Specific MR signal intensity patterns appear to correlate with degrees of improvement in the neurologic status in spinal cord injury patients. Histologic correlation of two types of MR signal intensity patterns are confirmed in the current study using a rat animal model. Adult male Sprague-Dawley rats underwent spinal cord trauma at the midthoracic level using a weight-dropping technique. After laminectomy, 5- and 10-gm brass weights were dropped from designated heights onto a 0.1-gm impounder placed on the exposed dura. Animals allowed to regain consciousness demonstrated variable recovery of hind limb paraplegia. Magnetic resonance images were obtained from 2 hours to 1 week after injury using a 2-tesla MRI/spectrometer. Sacrifice under anesthesia was performed by perfusive fixation; spinal columns were excised en bloc, embedded, sectioned, and observed with the compound light microscope. Magnetic resonance axial images obtained during the time sequence after injury demonstrate a distinct correlation between MR signal intensity patterns and the histologic appearance of the spinal cord. Magnetic resonance imaging delineates the pathologic processes resulting from acute spinal cord injury and can be used to differentiate the type of injury and prognosis.
Correlation of BOLD Signal with Linear and Nonlinear Patterns of EEG in Resting State EEG-Informed fMRI

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Galina V. Portnova

2018-01-01

Full Text Available Concurrent EEG and fMRI acquisitions in resting state showed a correlation between EEG power in various bands and spontaneous BOLD fluctuations. However, there is a lack of data on how changes in the complexity of brain dynamics derived from EEG reflect variations in the BOLD signal. The purpose of our study was to correlate both spectral patterns, as linear features of EEG rhythms, and nonlinear EEG dynamic complexity with neuronal activity obtained by fMRI. We examined the relationships between EEG patterns and brain activation obtained by simultaneous EEG-fMRI during the resting state condition in 25 healthy right-handed adult volunteers. Using EEG-derived regressors, we demonstrated a substantial correlation of BOLD signal changes with linear and nonlinear features of EEG. We found the most significant positive correlation of fMRI signal with delta spectral power. Beta and alpha spectral features had no reliable effect on BOLD fluctuation. However, dynamic changes of alpha peak frequency exhibited a significant association with BOLD signal increase in right-hemisphere areas. Additionally, EEG dynamic complexity as measured by the HFD of the 2–20 Hz EEG frequency range significantly correlated with the activation of cortical and subcortical limbic system areas. Our results indicate that both spectral features of EEG frequency bands and nonlinear dynamic properties of spontaneous EEG are strongly associated with fluctuations of the BOLD signal during the resting state condition.
Anti-Inflammatory Prostanoids: Focus on the Interactions between Electrophile Signaling and Resolution of Inflammation

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Beatriz Díez-Dacal

2010-01-01

Full Text Available Prostanoids are products of cyclooxygenase biosynthetic pathways and constitute a family of lipidic mediators of widely diverse structures and biological actions. Besides their known proinflammatory role, numerous works have revealed the anti-inflammatory effects of various prostanoids and established their role in the resolution of inflammation. Among these, prostaglandins with cyclopentenone structure (cyPG are electrophilic lipids that may act through various mechanisms, including the activation of nuclear and membrane receptors and, importantly, direct addition to protein cysteine residues and modification of protein function. Due to their ability to influence cysteine modification–mediated signaling, cyPG may play a critical role in the interplay between redox and inflammatory signaling pathways. Moreover, cellular redox status modulates cyPG addition to proteins; thus, a reciprocal regulation exists between these two factors. After initial controversy, it is becoming clear that endogenous cyPG are generated at concentrations sufficient to promote inflammatory resolution. As for other prostanoids, cyPG effects are highly dependent on context factors and they may exert pro- or anti-inflammatory actions in a cell type–dependent manner, or even biphasic or dual actions in a given cell type or tissue. In light of the growing number of cyPG protein targets identified, cyPG resemble other pleiotropic mediators acting through protein modification. However, their complex structure results in an inter- and intramolecular selectivity of the residues being modified, thus opening the way for structure-activity and drug discovery studies. Detailed characterization of cyPG interactions with cellular proteins will help us to understand their mechanism of action fully and establish their therapeutic potential in inflammation.
A Method for Vibration-Based Structural Interrogation and Health Monitoring Based on Signal Cross-Correlation

International Nuclear Information System (INIS)

Trendafilova, I

2011-01-01

Vibration-based structural interrogation and health monitoring is a field which is concerned with the estimation of the current state of a structure or a component from its vibration response with regards to its ability to perform its intended function appropriately. One way to approach this problem is through damage features extracted from the measured structural vibration response. This paper suggests to use a new concept for the purposes of vibration-based health monitoring. The correlation between two signals, an input and an output, measured on the structure is used to develop a damage indicator. The paper investigates the applicability of the signal cross-correlation and a nonlinear alternative, the average mutual information between the two signals, for the purposes of structural health monitoring and damage assessment. The suggested methodology is applied and demonstrated for delamination detection in a composite beam.
Performance of Narrowband Signal Detection under Correlated Rayleigh Fading Based on Synthetic Array

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Ali Broumandan

2009-01-01

design parameters of probability of detection (Pd and probability of false alarm (Pfa. An optimum detector based on Estimator-Correlator (EC is developed, and its performance is compared with that of suboptimal Equal-Gain (EG combiner in different channel correlation scenarios. It is shown that in moderate channel correlation scenarios the detection performance of EC and EG is identical. The sensitivity of the proposed method to knowledge of motion parameters is also investigated. An extensive set of measurements based on CDMA-2000 pilot signals using the static antenna and synthetic array are used to experimentally verify these theoretical findings.
Linear correlation between fractal dimension of surface EMG signal from Rectus Femoris and height of vertical jump

International Nuclear Information System (INIS)

Ancillao, Andrea; Galli, Manuela; Rigoldi, Chiara; Albertini, Giorgio

2014-01-01

Fractal dimension was demonstrated to be able to characterize the complexity of biological signals. The EMG time series are well known to have a complex behavior and some other studies already tried to characterize these signals by their fractal dimension. This paper is aimed at studying the correlation between the fractal dimension of surface EMG signal recorded over Rectus Femoris muscles during a vertical jump and the height reached in that jump. Healthy subjects performed vertical jumps at different heights. Surface EMG from Rectus Femoris was recorded and the height of each jump was measured by an optoelectronic motion capture system. Fractal dimension of sEMG was computed and the correlation between fractal dimension and eight of the jump was studied. Linear regression analysis showed a very high correlation coefficient between the fractal dimension and the height of the jump for all the subjects. The results of this study show that the fractal dimension is able to characterize the EMG signal and it can be related to the performance of the jump. Fractal dimension is therefore an useful tool for EMG interpretation
A new similarity index for nonlinear signal analysis based on local extrema patterns

Science.gov (United States)

Niknazar, Hamid; Motie Nasrabadi, Ali; Shamsollahi, Mohammad Bagher

2018-02-01

Common similarity measures of time domain signals such as cross-correlation and Symbolic Aggregate approximation (SAX) are not appropriate for nonlinear signal analysis. This is because of the high sensitivity of nonlinear systems to initial points. Therefore, a similarity measure for nonlinear signal analysis must be invariant to initial points and quantify the similarity by considering the main dynamics of signals. The statistical behavior of local extrema (SBLE) method was previously proposed to address this problem. The SBLE similarity index uses quantized amplitudes of local extrema to quantify the dynamical similarity of signals by considering patterns of sequential local extrema. By adding time information of local extrema as well as fuzzifying quantized values, this work proposes a new similarity index for nonlinear and long-term signal analysis, which extends the SBLE method. These new features provide more information about signals and reduce noise sensitivity by fuzzifying them. A number of practical tests were performed to demonstrate the ability of the method in nonlinear signal clustering and classification on synthetic data. In addition, epileptic seizure detection based on electroencephalography (EEG) signal processing was done by the proposed similarity to feature the potentials of the method as a real-world application tool.
Data interpolation for vibration diagnostics using two-variable correlations

International Nuclear Information System (INIS)

Branagan, L.

1991-01-01

This paper reports that effective machinery vibration diagnostics require a clear differentiation between normal vibration changes caused by plant process conditions and those caused by degradation. The normal relationship between vibration and a process parameter can be quantified by developing the appropriate correlation. The differences in data acquisition requirements between dynamic signals (vibration spectra) and static signals (pressure, temperature, etc.) result in asynchronous data acquisition; the development of any correlation must then be based on some form of interpolated data. This interpolation can reproduce or distort the original measured quantity depending on the characteristics of the data and the interpolation technique. Relevant data characteristics, such as acquisition times, collection cycle times, compression method, storage rate, and the slew rate of the measured variable, are dependent both on the data handling and on the measured variable. Linear and staircase interpolation, along with the use of clustering and filtering, provide the necessary options to develop accurate correlations. The examples illustrate the appropriate application of these options
Sinomenine attenuates renal fibrosis through Nrf2-mediated inhibition of oxidative stress and TGFβ signaling

Energy Technology Data Exchange (ETDEWEB)

Qin, Tian [School of Life Science & Technology, China Pharmaceutical University, Nanjing 210009 (China); Yin, Shasha; Yang, Jun; Zhang, Qin; Liu, Yangyang [Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing 210093 (China); Huang, Fengjie, E-mail: hfj@cpu.edu.cn [School of Life Science & Technology, China Pharmaceutical University, Nanjing 210009 (China); Cao, Wangsen, E-mail: wangsencao@nju.edu.cn [Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing 210093 (China)

2016-08-01

Renal fibrosis is the common feature of chronic kidney disease and mainly mediated by TGFβ-associated pro-fibrogenic signaling, which causes excessive extracellular matrix accumulation and successive loss of kidney functions. Sinomenine (SIN), an alkaloid derived from medicinal herb extensively used in treatment of rheumatoid arthritis and various inflammatory disorders, displays renal protective properties in experimental animals; however its pharmacological potency against renal fibrosis is not explored. In this study we report that SIN possesses strong anti-renal fibrosis functions in kidney cell and in mouse fibrotic kidney. SIN beneficially modulated the pro-fibrogenic protein expression in TGFβ-treated kidney cells and attenuated the renal fibrotic pathogenesis incurred by unilateral ureteral obstruction (UUO), which correlated with its activation of Nrf2 signaling - the key defender against oxidative stress with anti-fibrotic potentials. Further investigation on its regulation of Nrf2 downstream events revealed that SIN significantly balanced oxidative stress via improving the expression and activity of anti-oxidant and detoxifying enzymes, and interrupted the pro-fibrogenic signaling of TGFβ/Smad and Wnt/β-catenin. Even more impressively SIN achieved its anti-fibrotic activities in an Nrf2-dependent manner, suggesting that SIN regulation of Nrf2-associated anti-fibrotic activities constitutes a critical component of SIN's renoprotective functions. Collectively our studies have demonstrated a novel anti-fibrotic property of SIN and its upstream events and provided a molecular basis for SIN's potential applications in treatment of renal fibrosis-associated kidney disorders. - Highlights: • Sinomenine has strong potency of inhibiting renal fibrosis in UUO mouse kidney. • Sinomenine attenuates the expression of profibrogenic proteins. • Sinomenine balances renal fibrosis-associated oxidative stress. • Sinomenine mitigates profibrogenic
A systematic review of anti-rotavirus serum IgA antibody titer as a potential correlate of rotavirus vaccine efficacy.

Science.gov (United States)

Patel, Manish; Glass, Roger I; Jiang, Baoming; Santosham, Mathuram; Lopman, Ben; Parashar, Umesh

2013-07-15

Identifying an immunological correlate of protection for rotavirus vaccines (Rotarix [RV1] and RotaTeq [RV5]) would substantially facilitate testing of interventions for improving efficacy in developing countries and evaluating additional candidate rotavirus vaccines. We accessed PubMed and ClinicalTrials.gov to identify immunogenicity and efficacy trials for RV1 and RV5 to correlate anti-rotavirus serum immunoglobulin A (IgA) antibody titers vs efficacy in regions stratified by all-cause under-5 mortality rates (u5MR). We established a cutoff point for IgA geometric mean concentration or titer (GMC) that predicted lower efficacy and calculated pooled vaccine efficacy among countries with high vs low IgA titers. We observed an inverse correlation between u5MR and IgA titers for RV1 (r(2) = 0.72; P efficacy and IgA titers for both vaccines (r(2) = 0.56; P = .005). Postimmunization anti-rotavirus IgA GMC vaccine efficacy. Efficacy during first 2 years of life was significantly lower among countries with IgA GMC 90 (85%; 95% CI, 82-88). We observed a significant correlation between IgA titers and rotavirus vaccine efficacy and hypothesize that a critical level of IgA antibody titer is associated with a sufficient level of sustained protection after rotavirus vaccination.
Correlation dynamics and enhanced signals for the identification of serial biomolecules and DNA bases

International Nuclear Information System (INIS)

Ahmed, Towfiq; Haraldsen, Jason T; Balatsky, Alexander V; Rehr, John J; Di Ventra, Massimiliano; Schuller, Ivan

2014-01-01

Nanopore-based sequencing has demonstrated a significant potential for the development of fast, accurate, and cost-efficient fingerprinting techniques for next generation molecular detection and sequencing. We propose a specific multilayered graphene-based nanopore device architecture for the recognition of single biomolecules. Molecular detection and analysis can be accomplished through the detection of transverse currents as the molecule or DNA base translocates through the nanopore. To increase the overall signal-to-noise ratio and the accuracy, we implement a new ‘multi-point cross-correlation’ technique for identification of DNA bases or other molecules on the single molecular level. We demonstrate that the cross-correlations between each nanopore will greatly enhance the transverse current signal for each molecule. We implement first-principles transport calculations for DNA bases surveyed across a multilayered graphene nanopore system to illustrate the advantages of the proposed geometry. A time-series analysis of the cross-correlation functions illustrates the potential of this method for enhancing the signal-to-noise ratio. This work constitutes a significant step forward in facilitating fingerprinting of single biomolecules using solid state technology. (paper)
Correlation dynamics and enhanced signals for the identification of serial biomolecules and DNA bases

Science.gov (United States)

Ahmed, Towfiq; Haraldsen, Jason T.; Rehr, John J.; Di Ventra, Massimiliano; Schuller, Ivan; Balatsky, Alexander V.

2014-03-01

Nanopore-based sequencing has demonstrated a significant potential for the development of fast, accurate, and cost-efficient fingerprinting techniques for next generation molecular detection and sequencing. We propose a specific multilayered graphene-based nanopore device architecture for the recognition of single biomolecules. Molecular detection and analysis can be accomplished through the detection of transverse currents as the molecule or DNA base translocates through the nanopore. To increase the overall signal-to-noise ratio and the accuracy, we implement a new ‘multi-point cross-correlation’ technique for identification of DNA bases or other molecules on the single molecular level. We demonstrate that the cross-correlations between each nanopore will greatly enhance the transverse current signal for each molecule. We implement first-principles transport calculations for DNA bases surveyed across a multilayered graphene nanopore system to illustrate the advantages of the proposed geometry. A time-series analysis of the cross-correlation functions illustrates the potential of this method for enhancing the signal-to-noise ratio. This work constitutes a significant step forward in facilitating fingerprinting of single biomolecules using solid state technology.

Habitat-induced degradation of sound signals: Quantifying the effects of communication sounds and bird location on blur ratio, excess attenuation, and signal-to-noise ratio in blackbird song

DEFF Research Database (Denmark)

Dabelsteen, T.; Larsen, O N; Pedersen, Simon Boel

1993-01-01

measures were calculated from changes of the amplitude functions (i.e., envelopes) of the degraded songs using a new technique which allowed a compensation for the contribution of the background noise to the amplitude values. Representative songs were broadcast in a deciduous forest without leaves......The habitat-induced degradation of the full song of the blackbird (Turdus merula) was quantified by measuring excess attenuation, reduction of the signal-to-noise ratio, and blur ratio, the latter measure representing the degree of blurring of amplitude and frequency patterns over time. All three...
Detection of anti-aquaporin-4 autoantibodies in the sera of Chinese neuromyelitis optica patients

Institute of Scientific and Technical Information of China (English)

Miao Li; Weiheng Su; Jie Wang; Francesco Pisani; Antonio Frigeri; Tonghui Ma

2013-01-01

In this study, we recruited 10 neuromyelitis optica patients, two multiple sclerosis patients and two myelitis patients. Chinese hamster lung fibroblast (V79) cells transfected with a human aquaporin-4-mCherry fusion protein gene were used to detect anti-aquaporin-4 antibody in neuromyelitis optica patient sera by immunofluorescence. Anti-aquaporin-4 autoantibody was stably detected by immunofluorescence in neuromyelitis optica patient sera exclusively. The sensitivity of the assay for neuromyelitis optica was 90% and the specificity for neuromyelitis optica was 100%. The anti-aquaporin-4 antibody titers in sera were tested with serial dilutions until the signal disappeared. A positive correlation was detected between Expanded Disability Status Scale scores and serum anti-aquaporin-4 antibody titers. The anti-aquaporin-4 antibody assay is highly sensitive and specific in the sera of Chinese neuromyelitis optica patients. Detection of aquaporin-4 autoantibody is important for the diagnosis and treatment of neuromyelitis optica.
Detection of anti-aquaporin-4 autoantibodies in the sera of Chinese neuromyelitis optica patients.

Science.gov (United States)

Li, Miao; Su, Weiheng; Wang, Jie; Pisani, Francesco; Frigeri, Antonio; Ma, Tonghui

2013-03-15

In this study, we recruited 10 neuromyelitis optica patients, two multiple sclerosis patients and two myelitis patients. Chinese hamster lung fibroblast (V79) cells transfected with a human aquaporin-4-mCherry fusion protein gene were used to detect anti-aquaporin-4 antibody in neuromyelitis optica patient sera by immunofluorescence. Anti-aquaporin-4 autoantibody was stably detected by immunofluorescence in neuromyelitis optica patient sera exclusively. The sensitivity of the assay for neuromyelitis optica was 90% and the specificity for neuromyelitis optica was 100%. The anti-aquaporin-4 antibody titers in sera were tested with serial dilutions until the signal disappeared. A positive correlation was detected between Expanded Disability Status Scale scores and serum anti-aquaporin-4 antibody titers. The anti-aquaporin-4 antibody assay is highly sensitive and specific in the sera of Chinese neuromyelitis optica patients. Detection of aquaporin-4 autoantibody is important for the diagnosis and treatment of neuromyelitis optica.
Detection of anti-aquaporin-4 autoantibodies in the sera of Chinese neuromyelitis optica patients★

Science.gov (United States)

Li, Miao; Su, Weiheng; Wang, Jie; Pisani, Francesco; Frigeri, Antonio; Ma, Tonghui

2013-01-01

In this study, we recruited 10 neuromyelitis optica patients, two multiple sclerosis patients and two myelitis patients. Chinese hamster lung fibroblast (V79) cells transfected with a human aquaporin-4-mCherry fusion protein gene were used to detect anti-aquaporin-4 antibody in neuromyelitis optica patient sera by immunofluorescence. Anti-aquaporin-4 autoantibody was stably detected by immunofluorescence in neuromyelitis optica patient sera exclusively. The sensitivity of the assay for neuromyelitis optica was 90% and the specificity for neuromyelitis optica was 100%. The anti-aquaporin-4 antibody titers in sera were tested with serial dilutions until the signal disappeared. A positive correlation was detected between Expanded Disability Status Scale scores and serum anti-aquaporin-4 antibody titers. The anti-aquaporin-4 antibody assay is highly sensitive and specific in the sera of Chinese neuromyelitis optica patients. Detection of aquaporin-4 autoantibody is important for the diagnosis and treatment of neuromyelitis optica. PMID:25206717
Novel Junction-specific and Quantifiable In Situ Detection of AR-V7 and its Clinical Correlates in Metastatic Castration-resistant Prostate Cancer.

Science.gov (United States)

Zhu, Yezi; Sharp, Adam; Anderson, Courtney M; Silberstein, John L; Taylor, Maritza; Lu, Changxue; Zhao, Pei; De Marzo, Angelo M; Antonarakis, Emmanuel S; Wang, Mindy; Wu, Xingyong; Luo, Yuling; Su, Nan; Nava Rodrigues, Daniel; Figueiredo, Ines; Welti, Jonathan; Park, Emily; Ma, Xiao-Jun; Coleman, Ilsa; Morrissey, Colm; Plymate, Stephen R; Nelson, Peter S; de Bono, Johann S; Luo, Jun

2018-05-01

Androgen receptor splice variant 7 (AR-V7) has been implicated in resistance to abiraterone and enzalutamide treatment in men with metastatic castration-resistant prostate cancer (mCRPC). Tissue- or cell-based in situ detection of AR-V7, however, has been limited by lack of specificity. To address current limitations in precision measurement of AR-V7 by developing a novel junction-specific AR-V7 RNA in situ hybridization (RISH) assay compatible with automated quantification. We designed a RISH method to visualize single splice junctions in cells and tissue. Using the validated assay for junction-specific detection of the full-length AR (AR-FL) and AR-V7, we generated quantitative data, blinded to clinical data, for 63 prostate tumor biopsies. We evaluated clinical correlates of AR-FL/AR-V7 measurements, including association with prostate-specific antigen progression-free survival (PSA-PFS) and clinical and radiographic progression-free survival (PFS), in a subset of patients starting treatment with abiraterone or enzalutamide following biopsy. Quantitative AR-FL/AR-V7 data were generated from 56 of the 63 (88.9%) biopsy specimens examined, of which 44 were mCRPC biopsies. Positive AR-V7 signals were detected in 34.1% (15/44) mCRPC specimens, all of which also co-expressed AR-FL. The median AR-V7/AR-FL ratio was 11.9% (range 2.7-30.3%). Positive detection of AR-V7 was correlated with indicators of high disease burden at baseline. Among the 25 CRPC biopsies collected before treatment with abiraterone or enzalutamide, positive AR-V7 detection, but not higher AR-FL, was significantly associated with shorter PSA-PFS (hazard ratio 2.789, 95% confidence interval 1.12-6.95; p=0.0081). We report for the first time a RISH method for highly specific and quantifiable detection of splice junctions, allowing further characterization of AR-V7 and its clinical significance. Higher AR-V7 levels detected and quantified using a novel method were associated with poorer response to
Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite

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A. Rozhnoi

2008-10-01

Full Text Available In our earlier papers we have found the effect of VLF transmitter signal depression over epicenters of the large earthquakes from observation on the French DEMETER satellite that can be considered as new method of global diagnostics of seismic influence on the ionosphere. At present paper we investigate a possibility VLF signal-ionospheric turbulence interaction using additional characteristic of VLF signal-spectrum broadening. This characteristic is important for estimation of the interaction type: linear or nonlinear scattering. Our main results are the following:
– There are two zones of increased spectrum broadening, which are centered near magnetic latitudes Φ=±10° and Φ=±40°. Basing on the previous case study research and ground ionosonde registrations, probably it is evidence of nonlinear (active scattering of VLF signal on the ionospheric turbulence. However occurrence rate of spectrum broadening in the middle-latitude area is higher than in the near-equatorial zone (~15–20% in comparison with ~100% in former area that is probably coincides with the rate of ionospheric turbulence.
– From two years statistics of observation in the selected 3 low-latitude regions and 1 middle-latitude region inside reception area of VLF signal from NWC transmitter we find a correlation of spectrum broadening neither with ion-cyclotron noise (f=150–500 Hz, which possibly means poor representation of the turbulence by the noise due to its mixture with natural ELF emission (which correlates with whistler, nor with magnetic storm activity.
– We find rather evident correlation of ion-cyclotron frequency noise, VLF signal depression and weak correlation of spectrum broadening with seismicity in the middle-latitude region over Japan. But in the low-latitude regions we do not find such a correlation. Statistical decrease of VLF signal supports our previous case study results. However rather weak spectrum broadening
Correlating Nitrile IR Frequencies to Local Electrostatics Quantifies Noncovalent Interactions of Peptides and Proteins.

Science.gov (United States)

Deb, Pranab; Haldar, Tapas; Kashid, Somnath M; Banerjee, Subhrashis; Chakrabarty, Suman; Bagchi, Sayan

2016-05-05

Noncovalent interactions, in particular the hydrogen bonds and nonspecific long-range electrostatic interactions are fundamental to biomolecular functions. A molecular understanding of the local electrostatic environment, consistently for both specific (hydrogen-bonding) and nonspecific electrostatic (local polarity) interactions, is essential for a detailed understanding of these processes. Vibrational Stark Effect (VSE) has proven to be an extremely useful method to measure the local electric field using infrared spectroscopy of carbonyl and nitrile based probes. The nitrile chemical group would be an ideal choice because of its absorption in an infrared spectral window transparent to biomolecules, ease of site-specific incorporation into proteins, and common occurrence as a substituent in various drug molecules. However, the inability of VSE to describe the dependence of IR frequency on electric field for hydrogen-bonded nitriles to date has severely limited nitrile's utility to probe the noncovalent interactions. In this work, using infrared spectroscopy and atomistic molecular dynamics simulations, we have reported for the first time a linear correlation between nitrile frequencies and electric fields in a wide range of hydrogen-bonding environments that may bridge the existing gap between VSE and H-bonding interactions. We have demonstrated the robustness of this field-frequency correlation for both aromatic nitriles and sulfur-based nitriles in a wide range of molecules of varying size and compactness, including small molecules in complex solvation environments, an amino acid, disordered peptides, and structured proteins. This correlation, when coupled to VSE, can be used to quantify noncovalent interactions, specific or nonspecific, in a consistent manner.
On the Nature of the mHz X-Ray QPOs from ULX M82 X-1: Evidence for Timing-Spectral (anti) Correlation

Science.gov (United States)

Pasham, Dheeraj R.; Strohmayer, Tod E.

2013-01-01

Using all the archival XMM-Newton X-ray (3-10 keV) observations of the ultraluminous X-ray source (ULX) M82 X-1 we searched for a correlation between its variable mHz quasi-periodic oscillation (QPO) frequency and its energy spectral power-law index. These quantities are known to correlate in stellar mass black holes (StMBHs) exhibiting Type-C QPOs (approx 0.2-15 Hz). The detection of such a correlation would strengthen the identification of its mHz QPOs as Type-C and enable a more reliable mass estimate by scaling its QPO frequencies to those of Type-C QPOs in StMBHs of known mass. We resolved the count rates of M82 X-1 and a nearby bright ULX (source 5/X42.3+59) through surface brightness modeling and identify observations in which M82 X-1 was at least as bright as source 5. Using only those observations, we detect QPOs in the frequency range of 36-210 mHz during which the energy spectral power-law index varied from 1.7-2.2. Interestingly, we find evidence for an anti-correlation (Pearsons correlation coefficient = -0.95) between the power-law index and the QPO centroid frequency. While such an anti-correlation is observed in StMBHs at high Type-C QPO frequencies (approx 5-15 Hz), the frequency range over which it holds in StMBHs is significantly smaller (factor of approx 1.5-3) than the QPO range reported here from M82 X-1 (factor of 6). However, it remains possible that contamination from source 5 can bias our result. Joint Chandra/XMM-Newton observations in the future can resolve this problem and confirm the timing-spectral anti-correlation reported here.
Widespread correlation patterns of fMRI signal across visual cortex reflect eccentricity organization

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Arcaro, Michael J; Honey, Christopher J; Mruczek, Ryan EB; Kastner, Sabine; Hasson, Uri

2015-01-01

The human visual system can be divided into over two-dozen distinct areas, each of which contains a topographic map of the visual field. A fundamental question in vision neuroscience is how the visual system integrates information from the environment across different areas. Using neuroimaging, we investigated the spatial pattern of correlated BOLD signal across eight visual areas on data collected during rest conditions and during naturalistic movie viewing. The correlation pattern between areas reflected the underlying receptive field organization with higher correlations between cortical sites containing overlapping representations of visual space. In addition, the correlation pattern reflected the underlying widespread eccentricity organization of visual cortex, in which the highest correlations were observed for cortical sites with iso-eccentricity representations including regions with non-overlapping representations of visual space. This eccentricity-based correlation pattern appears to be part of an intrinsic functional architecture that supports the integration of information across functionally specialized visual areas. DOI: http://dx.doi.org/10.7554/eLife.03952.001 PMID:25695154
[Anti-angiogenic drugs].

Science.gov (United States)

Sato, Yasufumi

2010-06-01

Angiogenesis or neovascularization, the formation of neo-vessels, is a physiological phenomenon endued in vasculature, but is involved in various pathological conditions. Angiogenesis is required for tumor growth and metastasis, and thus constitutes an important target for the control of tumor progression. Indeed, the recent development of bevacizumab, a neutralizing anti-VEGF monoclonal antibody as the first anti-angiogenic drug, legalized the clinical merit of anti-angiogenesis in cancers. Thereafter, various drugs targeting VEGF-mediated signals have been developed to control tumor angiogenesis. Thus, anti-angiogenic drugs are now recognized in the clinic as a major step forward for the treatment of cancers. This review focuses on the current status of antiangiogenesis treatment in cancers.
Bleed-through correction for rendering and correlation analysis in multi-colour localization microscopy

International Nuclear Information System (INIS)

Kim, Dahan; Curthoys, Nikki M; Parent, Matthew T; Hess, Samuel T

2013-01-01

Multi-colour localization microscopy has enabled sub-diffraction studies of colocalization between multiple biological species and quantification of their correlation at length scales previously inaccessible with conventional fluorescence microscopy. However, bleed-through, or misidentification of probe species, creates false colocalization and artificially increases certain types of correlation between two imaged species, affecting the reliability of information provided by colocalization and quantified correlation. Despite the potential risk of these artefacts of bleed-through, neither the effect of bleed-through on correlation nor methods for its correction in correlation analyses have been systematically studied at typical rates of bleed-through reported to affect multi-colour imaging. Here, we present a reliable method of bleed-through correction applicable to image rendering and correlation analysis of multi-colour localization microscopy. Application of our bleed-through correction shows that our method accurately corrects the artificial increase in both types of correlation studied (Pearson coefficient and pair correlation), at all rates of bleed-through tested, in all types of correlation examined. In particular, anti-correlation could not be quantified without our bleed-through correction, even at rates of bleed-through as low as 2%. While it is demonstrated with dichroic-based multi-colour FPALM here, our presented method of bleed-through correction can be applied to all types of localization microscopy (PALM, STORM, dSTORM, GSDIM, etc), including both simultaneous and sequential multi-colour modalities, provided the rate of bleed-through can be reliably determined. (special issue article)
Biospectroscopy for studying the influences of anti-diabetic metals (V, Cr, Mo, and W) to the insulin signaling pathway

Science.gov (United States)

Safitri, Anna; Levina, Aviva; Lee, Joonsup; Carter, Elizabeth A.; Lay, Peter A.

2017-03-01

The prevalence of diabetes, particularly with respect to type 2 diabetes, has reached epidemic proportions and continues to grow worldwide. One of the potential therapeutic targets in the treatment of type 2 diabetes involves the role of protein tyrosine phosphatases in the negative regulation of insulin signaling. The complexes of V(V/IV), Cr(III), W(VI), and Mo(VI), have all been proposed as possible drugs in the treatment of diabetes mellitus. Anti-diabetic activities of V(V/IV), Cr(III), Mo(VI), and W(VI) compounds are likely to be based on similar mechanisms, which involve phosphorylation/dephosphorylation reactions in the glucose uptake and metabolism. In order to clearly understand biological activities and phosphorylation/dephosphorylation reactions involved in anti-diabetic actions of Cr(III), V(V/IV), Mo(VI), and W(VI) complexes, the current research involves the use of cultured insulin-sensitive cells treated with these compounds. These reactions were investigated through vibrational spectroscopy. Protein phosphorylation/dephosphorylation induced conformational changes in secondary protein structure from α-helix to β-sheet, and these changes were detected by the IR spectra, which showed changes in the wavenumber and intensities of signals within the composite protein amide I band.
Correlation analysis of motor current and chatter vibration in grinding using complex continuous wavelet coherence

International Nuclear Information System (INIS)

Liu, Yao; Wang, Xiufeng; Lin, Jing; Zhao, Wei

2016-01-01

Motor current is an emerging and popular signal which can be used to detect machining chatter with its multiple advantages. To achieve accurate and reliable chatter detection using motor current, it is important to make clear the quantitative relationship between motor current and chatter vibration, which has not yet been studied clearly. In this study, complex continuous wavelet coherence, including cross wavelet transform and wavelet coherence, is applied to the correlation analysis of motor current and chatter vibration in grinding. Experimental results show that complex continuous wavelet coherence performs very well in demonstrating and quantifying the intense correlation between these two signals in frequency, amplitude and phase. When chatter occurs, clear correlations in frequency and amplitude in the chatter frequency band appear and the phase difference of current signal to vibration signal turns from random to stable. The phase lead of the most correlated chatter frequency is the largest. With the further development of chatter, the correlation grows up in intensity and expands to higher order chatter frequency band. The analyzing results confirm that there is a consistent correlation between motor current and vibration signals in the grinding chatter process. However, to achieve accurate and reliable chatter detection using motor current, the frequency response bandwidth of current loop of the feed drive system must be wide enough to response chatter effectively. (paper)
Correlation of non-mass-like abnormal MR signal intensity with pathological findings surrounding pediatric osteosarcoma and Ewing's sarcoma

Energy Technology Data Exchange (ETDEWEB)

Masrouha, Karim Z.; Haidar, Rachid; Saghieh, Said [American University of Beirut Medical Center, Department of Surgery, Beirut (Lebanon); Musallam, Khaled M. [American University of Beirut Medical Center, Internal Medicine Division of Hematology and Oncology, Beirut (Lebanon); Samra, Alexis Bou; Tawil, Ayman; Chakhachiro, Zaher [American University of Beirut Medical Center, Pathology, Beirut (Lebanon); Abdallah, Abeer; Khoury, Nabil J. [American University of Beirut Medical Center, Diagnostic Radiology, Beirut (Lebanon); Saab, Raya; Muwakkit, Samar; Abboud, Miguel R. [American University of Beirut Medical Center, Children' s Cancer Center of Lebanon, Beirut (Lebanon)

2012-11-15

The aim of this work was to determine the role of MRI in interpreting abnormal signals within bones and soft tissues adjacent to tumor bulk of osteosarcoma and Ewing's sarcoma in a pediatric population by correlating MR findings with histopathology. Thirty patients met the inclusion criteria, which included (1) osteosarcoma or Ewing's sarcoma, (2) MR studies no more than 2 months prior to surgery, (3) presence of abnormal MR signal surrounding the tumor bulk, (4) pathological material from resected tumor. The patients received standard neoadjuvant chemotherapy. Using grid maps on gross pathology specimens, the abnormal MR areas around the tumor were matched with the corresponding grid sections. Histopathology slides of these sections were then analyzed to determine the nature of the regions of interest. The MR/pathological correlation was evaluated using Mann-Whitney U test and Fisher's exact test. Twenty-seven patients had osteosarcoma and three patients had Ewing's sarcoma. Of the studied areas, 17.4% were positive for tumor (viable or necrotic). There was no statistically significant correlation between areas positive for tumor and age, gender, signal extent and intensity on MRI, or tissue type. There was, however, a statistically significant correlation between presence of tumor and the appearance of abnormal soft tissue signals. A feathery appearance correlated with tumor-negative areas whereas a bulky appearance correlated with tumor-positive regions. MR imaging is helpful in identifying the nature of abnormal signal areas surrounding bone sarcomas that are more likely to be tumor-free, particularly when the signal in the soft tissues surrounding the tumor is feathery and edema-like in appearance. (orig.)
PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of posttraumatic epilepsy

OpenAIRE

Berdichevsky, Yevgeny; Dryer, Alexandra M.; Saponjian, Yero; Mahoney, Mark M.; Pimentel, Corrin A.; Lucini, Corrina A.; Usenovic, Marija; Staley, Kevin J.

2013-01-01

mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an antiepileptogenic, or merely anti-convulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordi...
Spatio-temporal image correlation spectroscopy and super-resolution microscopy to quantify molecular dynamics in T cells.

Science.gov (United States)

Ashdown, George W; Owen, Dylan M

2018-02-02

Many cellular processes are regulated by the spatio-temporal organisation of signalling complexes, cytoskeletal components and membranes. One such example is at the T cell immunological synapse where the retrograde flow of cortical filamentous (F)-actin from the synapse periphery drives signalling protein microclusters towards the synapse centre. The density of this mesh however, makes visualisation and analysis of individual actin fibres difficult due to the resolution limit of conventional microscopy. Recently, super-resolution methods such as structured illumination microscopy (SIM) have surpassed this resolution limit. Here, we apply SIM to better visualise the dense cortical actin meshwork in T cell synapses formed against activating, antibody-coated surfaces and image under total-internal reflection fluorescence (TIRF) illumination. To analyse the observed molecular flows, and the relationship between them, we apply spatio-temporal image correlation spectroscopy (STICS) and its cross-correlation variant (STICCS). We show that the dynamic cortical actin mesh can be visualised with unprecedented detail and that STICS/STICCS can output accurate, quantitative maps of molecular flow velocity and directionality from such data. We find that the actin flow can be disrupted using small molecule inhibitors of actin polymerisation. This combination of imaging and quantitative analysis may provide an important new tool for researchers to investigate the molecular dynamics at cellular length scales. Here we demonstrate the retrograde flow of F-actin which may be important for the clustering and dynamics of key signalling proteins within the plasma membrane, a phenomenon which is vital to correct T cell activation and therefore the mounting of an effective immune response. Copyright © 2018. Published by Elsevier Inc.
QUANTIFYING THE SHORT LIFETIME WITH TCSPC-FLIM: FIRST MOMENT VERSUS FITTING METHODS

Directory of Open Access Journals (Sweden)

LINGLING XU

2013-10-01

Full Text Available Combing the time-correlated single photon counting (TCSPC with fluorescence lifetime imaging microscopy (FLIM provides promising opportunities in revealing important information on the microenvironment of cells and tissues, but the applications are thus far mainly limited by the accuracy and precision of the TCSPC-FLIM technique. Here we present a comprehensive investigation on the performance of two data analysis methods, the first moment (M1 method and the conventional least squares (Fitting method, in quantifying fluorescence lifetime. We found that the M1 method is more superior than the Fitting method when the lifetime is short (70 ~ 400 ps or the signal intensity is weak (<103 photons.
Musical Imagery Involves Wernicke's Area in Bilateral and Anti-Correlated Network Interactions in Musicians.

Science.gov (United States)

Zhang, Yizhen; Chen, Gang; Wen, Haiguang; Lu, Kun-Han; Liu, Zhongming

2017-12-06

Musical imagery is the human experience of imagining music without actually hearing it. The neural basis of this mental ability is unclear, especially for musicians capable of engaging in accurate and vivid musical imagery. Here, we created a visualization of an 8-minute symphony as a silent movie and used it as real-time cue for musicians to continuously imagine the music for repeated and synchronized sessions during functional magnetic resonance imaging (fMRI). The activations and networks evoked by musical imagery were compared with those elicited by the subjects directly listening to the same music. Musical imagery and musical perception resulted in overlapping activations at the anterolateral belt and Wernicke's area, where the responses were correlated with the auditory features of the music. Whereas Wernicke's area interacted within the intrinsic auditory network during musical perception, it was involved in much more complex networks during musical imagery, showing positive correlations with the dorsal attention network and the motor-control network and negative correlations with the default-mode network. Our results highlight the important role of Wernicke's area in forming vivid musical imagery through bilateral and anti-correlated network interactions, challenging the conventional view of segregated and lateralized processing of music versus language.
Interictal functional connectivity of human epileptic networks assessed by intracerebral EEG and BOLD signal fluctuations.

Directory of Open Access Journals (Sweden)

Gaelle Bettus

Full Text Available In this study, we aimed to demonstrate whether spontaneous fluctuations in the blood oxygen level dependent (BOLD signal derived from resting state functional magnetic resonance imaging (fMRI reflect spontaneous neuronal activity in pathological brain regions as well as in regions spared by epileptiform discharges. This is a crucial issue as coherent fluctuations of fMRI signals between remote brain areas are now widely used to define functional connectivity in physiology and in pathophysiology. We quantified functional connectivity using non-linear measures of cross-correlation between signals obtained from intracerebral EEG (iEEG and resting-state functional MRI (fMRI in 5 patients suffering from intractable temporal lobe epilepsy (TLE. Functional connectivity was quantified with both modalities in areas exhibiting different electrophysiological states (epileptic and non affected regions during the interictal period. Functional connectivity as measured from the iEEG signal was higher in regions affected by electrical epileptiform abnormalities relative to non-affected areas, whereas an opposite pattern was found for functional connectivity measured from the BOLD signal. Significant negative correlations were found between the functional connectivities of iEEG and BOLD signal when considering all pairs of signals (theta, alpha, beta and broadband and when considering pairs of signals in regions spared by epileptiform discharges (in broadband signal. This suggests differential effects of epileptic phenomena on electrophysiological and hemodynamic signals and/or an alteration of the neurovascular coupling secondary to pathological plasticity in TLE even in regions spared by epileptiform discharges. In addition, indices of directionality calculated from both modalities were consistent showing that the epileptogenic regions exert a significant influence onto the non epileptic areas during the interictal period. This study shows that functional
Validation of a rapid, non-radioactive method to quantify internalisation of G-protein coupled receptors.

Science.gov (United States)

Jongsma, Maikel; Florczyk, Urszula M; Hendriks-Balk, Mariëlle C; Michel, Martin C; Peters, Stephan L M; Alewijnse, Astrid E

2007-07-01

Agonist exposure can cause internalisation of G-protein coupled receptors (GPCRs), which may be a part of desensitisation but also of cellular signaling. Previous methods to study internalisation have been tedious or only poorly quantitative. Therefore, we have developed and validated a quantitative method using a sphingosine-1-phosphate (S1P) receptor as a model. Because of a lack of suitable binding studies, it has been difficult to study S1P receptor internalisation. Using a N-terminal HisG-tag, S1P(1) receptors on the cell membrane can be visualised via immunocytochemistry with a specific anti-HisG antibody. S1P-induced internalisation was concentration dependent and was quantified using a microplate reader, detecting either absorbance, a fluorescent or luminescent signal, depending on the antibodies used. Among those, the fluorescence detection method was the most convenient to use. The relative ease of this method makes it suitable to measure a large number of data points, e.g. to compare the potency and efficacy of receptor ligands.

Correlation Between Electromagnetic Signals and Seismic Events on Central Colombia Region to Establish Seismic Precursors Existence

Science.gov (United States)

Caneva, A.; Vargas Jiménez, C. A.; Solano Fino, J. M.

2017-12-01

It was already shown by several authors around the world some kinds of correlation between electric and magnetic signals and seismic events looking for precursors to the last ones emitted from the seismic source. This investigation tends to establish a correlation between electro-magnetic (EM) signals on the ground surface and seismic events on the Colombian lithospheric system. The events correlation was made with data from the Seismological Network of the Sabana de Bogotá (RSSB for its acronym in Spanish), a temporal seismological network on Chichimene (Acacías, Meta, Colombia) and the National Seismological Network of Colombia (RSNC, for its acronym in Spanish). The project involved the design, construction and preliminary tests for the necessary instruments added to the RSSB as multi-parameter stations with seismic broadband, electric polarizing and non-polarizing dipoles and Earth's magnetic field sensors. Correlations were made considering time, frequency and `natural time' domains with filtering and preprocessing algorithms. Among the main results are the almost complete lack of electric disturbances known as Seismic Electric Signals (SES) and very few of the magnetic kind. However, another kind of long period magnetic disturbances for some stations and events where found. More instruments have to be deployed in order to get a better understanding of these disturbances and develop a robust model.
Oleoylethanolamide exerts anti-inflammatory effects on LPS-induced THP-1 cells by enhancing PPARα signaling and inhibiting the NF-κB and ERK1/2/AP-1/STAT3 pathways.

Science.gov (United States)

Yang, Lichao; Guo, Han; Li, Ying; Meng, Xianglan; Yan, Lu; Dan Zhang; Wu, Sangang; Zhou, Hao; Peng, Lu; Xie, Qiang; Jin, Xin

2016-10-10

The present study aimed to examine the anti-inflammatory actions of oleoylethanolamide (OEA) in lipopolysaccharide (LPS)-induced THP-1 cells. The cells were stimulated with LPS (1 μg/ml) in the presence or absence of OEA (10, 20 and 40 μM). The pro-inflammatory cytokines were evaluated by qRT-PCR and ELISA. The THP-1 cells were transiently transfected with PPARα small-interfering RNA, and TLR4 activity was determined with a blocking test using anti-TLR4 antibody. Additionally, a special inhibitor was used to analyse the intracellular signaling pathway. OEA exerted a potent anti-inflammatory effect by reducing the production of pro-inflammatory cytokines and TLR4 expression, and by enhancing PPARα expression. The modulatory effects of OEA on LPS-induced inflammation depended on PPARα and TLR4. Importantly, OEA inhibited LPS-induced NF-κB activation, IκBα degradation, expression of AP-1, and the phosphorylation of ERK1/2 and STAT3. In summary, our results demonstrated that OEA exerts anti-inflammatory effects by enhancing PPARα signaling, inhibiting the TLR4-mediated NF-κB signaling pathway, and interfering with the ERK1/2-dependent signaling cascade (TLR4/ERK1/2/AP-1/STAT3), which suggests that OEA may be a therapeutic agent for inflammatory diseases.
Understanding volatility correlation behavior with a magnitude cross-correlation function

Science.gov (United States)

Jun, Woo Cheol; Oh, Gabjin; Kim, Seunghwan

2006-06-01

We propose an approach for analyzing the basic relation between correlation properties of the original signal and its magnitude fluctuations by decomposing the original signal into its positive and negative fluctuation components. We use this relation to understand the following phenomenon found in many naturally occurring time series: the magnitude of the signal exhibits long-range correlation, whereas the original signal is short-range correlated. The applications of our approach to heart rate variability signals and high-frequency foreign exchange rates reveal that the difference between the correlation properties of the original signal and its magnitude fluctuations is induced by the time organization structure of the correlation function between the magnitude fluctuations of positive and negative components. We show that this correlation function can be described well by a stretched-exponential function and is related to the nonlinearity and the multifractal structure of the signals.
Understanding volatility correlation behavior with a magnitude cross-correlation function.

Science.gov (United States)

Jun, Woo Cheol; Oh, Gabjin; Kim, Seunghwan

2006-06-01

We propose an approach for analyzing the basic relation between correlation properties of the original signal and its magnitude fluctuations by decomposing the original signal into its positive and negative fluctuation components. We use this relation to understand the following phenomenon found in many naturally occurring time series: the magnitude of the signal exhibits long-range correlation, whereas the original signal is short-range correlated. The applications of our approach to heart rate variability signals and high-frequency foreign exchange rates reveal that the difference between the correlation properties of the original signal and its magnitude fluctuations is induced by the time organization structure of the correlation function between the magnitude fluctuations of positive and negative components. We show that this correlation function can be described well by a stretched-exponential function and is related to the nonlinearity and the multifractal structure of the signals.
Anti-correlation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323

Science.gov (United States)

Yang, Jun; Zezas, Andreas; Coe, Malcolm J.; Drake, Jeremy J.; Hong, JaeSub; Laycock, Silas G. T.; Wik, Daniel R.

2018-05-01

We report the evidence for the anti-correlation between pulsed fraction (PF) and luminosity of the X-ray pulsar SXP 1323, found for the first time in a luminosity range 1035-1037 erg s-1 from observations spanning 15 years. The phenomenon of a decrease in X-ray PF when the source flux increases has been observed in our pipeline analysis of other X-ray pulsars in the Small Magellanic Cloud (SMC). It is expected that the luminosity under a certain value decreases as the PF decreases due to the propeller effect. Above the propeller region, an anti-correlation between the PF and flux might occur either as a result of an increase in the un-pulsed component of the total emission or a decrease of the pulsed component. Additional modes of accretion may also be possible, such as spherical accretion and a change in emission geometry. At higher mass accretion rates, the accretion disk could also extend closer to the neutron star (NS) surface, where a reduced inner radius leads to hotter inner disk emission. These modes of plasma accretion may affect the change in the beam configuration to fan-beam dominant emission.
Detection of anomalous signals in temporally correlated data (Invited)

Science.gov (United States)

Langbein, J. O.

2010-12-01

Detection of transient tectonic signals in data obtained from large geodetic networks requires the ability to detect signals that are both temporally and spatially coherent. In this report I will describe a modification to an existing method that estimates both the coefficients of temporally correlated noise model and an efficient filter based on the noise model. This filter, when applied to the original time-series, effectively whitens (or flattens) the power spectrum. The filtered data provide the means to calculate running averages which are then used to detect deviations from the background trends. For large networks, time-series of signal-to-noise ratio (SNR) can be easily constructed since, by filtering, each of the original time-series has been transformed into one that is closer to having a Gaussian distribution with a variance of 1.0. Anomalous intervals may be identified by counting the number of GPS sites for which the SNR exceeds a specified value. For example, during one time interval, if there were 5 out of 20 time-series with SNR>2, this would be considered anomalous; typically, one would expect at 95% confidence that there would be at least 1 out of 20 time-series with an SNR>2. For time intervals with an anomalously large number of high SNR, the spatial distribution of the SNR is mapped to identify the location of the anomalous signal(s) and their degree of spatial clustering. Estimating the filter that should be used to whiten the data requires modification of the existing methods that employ maximum likelihood estimation to determine the temporal covariance of the data. In these methods, it is assumed that the noise components in the data are a combination of white, flicker and random-walk processes and that they are derived from three different and independent sources. Instead, in this new method, the covariance matrix is constructed assuming that only one source is responsible for the noise and that source can be represented as a white
A Saccharomyces cerevisiae Assay System to Investigate Ligand/AdipoR1 Interactions That Lead to Cellular Signaling

KAUST Repository

Aouida, Mustapha

2013-06-07

Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used to study both AdipoRs separately. Agonist-AdipoR1 interactions are detected using a split firefly luciferase assay based on reconstitution of firefly luciferase (Luc) activity due to juxtaposition of its N- and C-terminal fragments, NLuc and CLuc, by ligand induced interaction of the chimeric proteins CLuc-AdipoR1 and APPL1-NLuc (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif 1-NLuc) in a S. cerevisiae strain lacking the yeast homolog of AdipoRs (Izh2p). The assay monitors the earliest known step in the adiponectin-AdipoR anti-diabetic signaling cascade. We demonstrate that reconstituted Luc activity can be detected in colonies or cells using a CCD camera and quantified in cell suspensions using a microplate reader. AdipoR1-APPL1 interaction occurs in absence of ligand but can be stimulated specifically by agonists such as adiponectin and the tobacco protein osmotin that was shown to have AdipoR-dependent adiponectin-like biological activity in mammalian cells. To further validate this assay, we have modeled the three dimensional structures of receptor-ligand complexes of membrane-embedded AdipoR1 with cyclic peptides derived from osmotin or osmotin-like plant proteins. We demonstrate that the calculated AdipoR1-peptide binding energies correlate with the peptides\\' ability to behave as AdipoR1 agonists in the split luciferase assay. Further, we demonstrate agonist-AdipoR dependent activation of protein kinase A (PKA) signaling and AMP activated protein kinase (AMPK) phosphorylation in S. cerevisiae, which are homologous to
Measurement of spin correlations in t anti t events from pp collisions at √(s)=7 TeV in the lepton+jets final state with the ATLAS detector

International Nuclear Information System (INIS)

Lemmer, Boris

2014-01-01

The top quark decays before it hadronises. Before its spin state can be changed in a process of strong interaction, it is directly transferred to the top quark decay products. The top quark spin can be deduced by studying angular distributions of the decay products. The Standard Model predicts the top/anti-top quark (t anti t) pairs to have correlated spins. The degree is sensitive to the spin and the production mechanisms of the top quark. Measuring the spin correlation allows to test the predictions. New physics effects can be reflected in deviations from the prediction. In this thesis the spin correlation of t anti t pairs, produced at a centre-of-mass energy of √(s)=7 TeV and reconstructed with the ATLAS detector, is measured. The dataset corresponds to an integrated luminosity of 4.6 fb -1 . t anti t pairs are reconstructed in the l+jets channel using a kinematic likelihood fit offering the identification of light up- and down-type quarks from the t→bW→bq anti q' decay. The spin correlation is measured via the distribution of the azimuthal angle Δφ between two top quark spin analyzers in the laboratory frame. It is expressed as the degree of t anti t spin correlation predicted by the Standard Model, f SM . The results of f SM (Δφ(charged lepton,down-type quark))=1.53±0.14(stat.)±0.32(syst.), f SM (Δφ(charged lepton,b-quark))=0.53±0.18(stat.)±0.49(syst.), f SM (Δφ(combined))=1.12±0.11(stat.)±0.22(syst.), are consistent with the Standard Model prediction of f SM =1.0.
Detection of Signal Regulatory Protein α in Saimiri sciureus (Squirrel Monkey) by Anti-Human Monoclonal Antibody

Science.gov (United States)

de Souza, Hugo Amorim dos Santos; Costa-Correa, Edmar Henrique; Bianco-Junior, Cesare; Andrade, Márcia Cristina Ribeiro; Lima-Junior, Josué da Costa; Pratt-Riccio, Lilian Rose; Daniel-Ribeiro, Cláudio Tadeu; Totino, Paulo Renato Rivas

2017-01-01

Non-human primates (NHP) are suitable models for studying different aspects of the human system, including pathogenesis and protective immunity to many diseases. However, the lack of specific immunological reagents for neo-tropical monkeys, such as Saimiri sciureus, is still a major factor limiting studies in these models. An alternative strategy to circumvent this obstacle has been the selection of immunological reagents directed to humans, which present cross-reactivity with NHP molecules. In this context and considering the key role of inhibitory immunoreceptors—such as the signal regulatory protein α (SIRPα)—in the regulation of immune responses, in the present study, we attempted to evaluate the ability of anti-human SIRPα monoclonal antibodies to recognize SIRPα in antigen-presenting S. sciureus peripheral blood mononuclear cells (PBMC). As shown by flow cytometry analysis, the profile of anti-SIRPα staining as well as the levels of SIRPα-positive cells in PBMC from S. sciureus were similar to those observed in human PBMC. Furthermore, using anti-SIRPα monoclonal antibody, it was possible to detect a decrease of the SIRPα levels on surface of S. sciureus cells after in vitro stimulation with lipopolysaccharides. Finally, using computed-based analysis, we observed a high degree of conservation of SIRPα across six species of primates and the presence of shared epitopes in the extracellular domain between humans and Saimiri genus that could be targeted by antibodies. In conclusion, we have identified a commercially available anti-human monoclonal antibody that is able to detect SIRPα of S. sciureus monkeys and that, therefore, can facilitate the study of the immunomodulatory role of SIRPα when S. sciureus is used as a model. PMID:29312325
Detection of Signal Regulatory Protein α in Saimiri sciureus (Squirrel Monkey by Anti-Human Monoclonal Antibody

Directory of Open Access Journals (Sweden)

Hugo Amorim dos Santos de Souza

2017-12-01

Full Text Available Non-human primates (NHP are suitable models for studying different aspects of the human system, including pathogenesis and protective immunity to many diseases. However, the lack of specific immunological reagents for neo-tropical monkeys, such as Saimiri sciureus, is still a major factor limiting studies in these models. An alternative strategy to circumvent this obstacle has been the selection of immunological reagents directed to humans, which present cross-reactivity with NHP molecules. In this context and considering the key role of inhibitory immunoreceptors—such as the signal regulatory protein α (SIRPα—in the regulation of immune responses, in the present study, we attempted to evaluate the ability of anti-human SIRPα monoclonal antibodies to recognize SIRPα in antigen-presenting S. sciureus peripheral blood mononuclear cells (PBMC. As shown by flow cytometry analysis, the profile of anti-SIRPα staining as well as the levels of SIRPα-positive cells in PBMC from S. sciureus were similar to those observed in human PBMC. Furthermore, using anti-SIRPα monoclonal antibody, it was possible to detect a decrease of the SIRPα levels on surface of S. sciureus cells after in vitro stimulation with lipopolysaccharides. Finally, using computed-based analysis, we observed a high degree of conservation of SIRPα across six species of primates and the presence of shared epitopes in the extracellular domain between humans and Saimiri genus that could be targeted by antibodies. In conclusion, we have identified a commercially available anti-human monoclonal antibody that is able to detect SIRPα of S. sciureus monkeys and that, therefore, can facilitate the study of the immunomodulatory role of SIRPα when S. sciureus is used as a model.
Redshift distortions of galaxy correlation functions

International Nuclear Information System (INIS)

Fry, J.N.; Florida Univ., Gainesville, FL; Gaztanaga, E.; Oxford Univ.

1993-01-01

To examine how peculiar velocities can affect the 2-, 3-, and 4-point correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We present the results as the correlation length r 0 and power index γ of the 2-point correlation, anti Ξ 2 = (r 0 /r) γ , and as the hierarchical amplitudes of the 3- and 4-point functions, S 3 = anti Ξ 3 /anti Ξ 2 2 and S 4 = anti Ξ/anti Ξ 2 3 . We find a characteristic distortion for anti Ξ 2 : The slope γ is flatter and the correlation length is larger in redshift space than in real space; that is, redshift distortions ''move'' correlations from small to large scales. At the largest scales, extra power in the redshift distribution is compatible with Ω 4/7 /b ∼ 1; we find 0.53 ± 0.15, 1.10 ± 0.16 and 0.84 ± 0.45 for the CfA, SSRS and IRAS catalogs. Higher order correlations anti Ξ 3 and anti Ξ 4 suffer similar redshift distortions, but in such a way that, within the accuracy of our analysis, the normalized amplitudes S 3 and S 4 are insensitive to this effect. The hierarchical amplitudes S 3 and S 4 are constant as a function of scale between 1-12 h -1 Mpc and have similar values in all samples and catalogues, S 3 ∼ 2 and S 4 ∼ 6, despite the fact that anti Ξ 2 , anti Ξ 3 , and anti Ξ 4 differ from one sample to another by large factors. The agreement between the independent estimations of S 3 and S 4 is remarkable given the different criteria in the selection of galaxies and also the difference in the resulting range of densities, luminosities and locations between samples
Anti-idiotypic antibodies directed against anti-HBs among the patients with chronic hepatitis B.

Science.gov (United States)

Kobayashi, K; Suzuki, H; Ueno, Y; Nagatomi, R; Kanno, A; Otsuki, M; Toyota, T

1990-08-01

Anti-idiotypic antibodies (anti-Id) against anti-HBs were found in the sera of patients with chronic hepatitis type B. Anti-idiotypic antibodies were detected by an enzyme-linked immunosorbent assay using horseradish peroxidase conjugated mouse monoclonal anti-HBs. Ten of 72 HBsAg positive sera contained anti-Id (13.9%). The prevalence of anti-Id did not appear to correlate with HBeAg/anti-HBe system. However, HB virus specific DNA polymerase activity was significantly higher in anti-Id positive sera. In the sera obtained from the patients treated with predonisolone before, anti-Id positive rate was higher than that in the patients without a history of predonisolone therapy. These results suggest that anti-Id may be related to the immunoregulatory mechanism of HB virus replication.
Establishing the diffuse correlation spectroscopy signal relationship with blood flow.

Science.gov (United States)

Boas, David A; Sakadžić, Sava; Selb, Juliette; Farzam, Parisa; Franceschini, Maria Angela; Carp, Stefan A

2016-07-01

Diffuse correlation spectroscopy (DCS) measurements of blood flow rely on the sensitivity of the temporal autocorrelation function of diffusively scattered light to red blood cell (RBC) mean square displacement (MSD). For RBCs flowing with convective velocity [Formula: see text], the autocorrelation is expected to decay exponentially with [Formula: see text], where [Formula: see text] is the delay time. RBCs also experience shear-induced diffusion with a diffusion coefficient [Formula: see text] and an MSD of [Formula: see text]. Surprisingly, experimental data primarily reflect diffusive behavior. To provide quantitative estimates of the relative contributions of convective and diffusive movements, we performed Monte Carlo simulations of light scattering through tissue of varying vessel densities. We assumed laminar vessel flow profiles and accounted for shear-induced diffusion effects. In agreement with experimental data, we found that diffusive motion dominates the correlation decay for typical DCS measurement parameters. Furthermore, our model offers a quantitative relationship between the RBC diffusion coefficient and absolute tissue blood flow. We thus offer, for the first time, theoretical support for the empirically accepted ability of the DCS blood flow index ([Formula: see text]) to quantify tissue perfusion. We find [Formula: see text] to be linearly proportional to blood flow, but with a proportionality modulated by the hemoglobin concentration and the average blood vessel diameter.
Real-Time EEG Signal Enhancement Using Canonical Correlation Analysis and Gaussian Mixture Clustering

Directory of Open Access Journals (Sweden)

Chin-Teng Lin

2018-01-01

Full Text Available Electroencephalogram (EEG signals are usually contaminated with various artifacts, such as signal associated with muscle activity, eye movement, and body motion, which have a noncerebral origin. The amplitude of such artifacts is larger than that of the electrical activity of the brain, so they mask the cortical signals of interest, resulting in biased analysis and interpretation. Several blind source separation methods have been developed to remove artifacts from the EEG recordings. However, the iterative process for measuring separation within multichannel recordings is computationally intractable. Moreover, manually excluding the artifact components requires a time-consuming offline process. This work proposes a real-time artifact removal algorithm that is based on canonical correlation analysis (CCA, feature extraction, and the Gaussian mixture model (GMM to improve the quality of EEG signals. The CCA was used to decompose EEG signals into components followed by feature extraction to extract representative features and GMM to cluster these features into groups to recognize and remove artifacts. The feasibility of the proposed algorithm was demonstrated by effectively removing artifacts caused by blinks, head/body movement, and chewing from EEG recordings while preserving the temporal and spectral characteristics of the signals that are important to cognitive research.
A randomized trial to assess anti-HIV activity in female genital tract secretions and soluble mucosal immunity following application of 1% tenofovir gel.

Directory of Open Access Journals (Sweden)

Marla J Keller

2011-01-01

Full Text Available Preclinical and early phase clinical microbicide studies have not consistently predicted the outcome of efficacy trials. To address this gap, candidate biomarkers of microbicide pharmacodynamics and safety were evaluated in a double-blind, placebo-controlled trial of tenofovir gel, the first microbicide to demonstrate significant protection against HIV acquisition.30 women were randomized to apply a single daily dose of tenofovir or placebo gel for 14 consecutive days. Anti-HIV activity was measured in cervicovaginal lavage (CVL on Days 0, 3, 7, 14 and 21 by luciferase assay as a surrogate marker of pharmacodynamics. Endogenous activity against E. coli and HSV-2 and concentrations of immune mediators were quantified in CVL as candidate biomarkers of safety. Tenofovir levels were measured in CVL and blood.A significant increase in anti-HIV activity was detected in CVL from women who applied tenofovir gel compared to their endogenous anti-HIV activity in genital tract secretions on Day 0 and compared to activity in CVL from women in the placebo group. The activity correlated significantly with CVL concentration of tenofovir (r = 0.6, p<0.001 and fit a sigmoid E(max pharmacodynamic model. Anti-HIV activity in CVL from women who applied tenofovir persisted when virus was introduced in semen, whereas endogenous anti-HIV activity decreased. Tenofovir did not trigger an inflammatory response or induce sustained loss in endogenous antimicrobial activity or immune mediators.Tenofovir gel had no deleterious impact on soluble mucosal immunity. The increased anti-HIV activity in CVL, which persisted in the presence of semen and correlated with tenofovir concentration, is consistent with the efficacy observed in a recent clinical trial. These results promote quantified CVL anti-HIV activity as a surrogate of tissue pharmacodynamics and as a potential biomarker of adherence to product. This simple, feasible and inexpensive bioassay may promote the development
Anti-inflammatory effects of exercise

DEFF Research Database (Denmark)

Pedersen, Bente Klarlund

2017-01-01

and IL-10 is provoked by exercise and exerts direct anti-inflammatory effects by an inhibition of TNF-α and by stimulating IL-1ra, thereby limiting IL-1β signalling. Moreover, muscle-derived IL-6 appears to have direct anti-inflammatory effects and serves as a mechanism to improve glucose tolerance....... In addition, indirect anti-inflammatory effects of long-term exercise are mediated via improvements in body composition. CONCLUSION: Physical activity represents a natural, strong anti-inflammatory strategy with minor side effects and should be integrated in the management of patients with cardiometabolic...
Quantifying and modeling long-range cross correlations in multiple time series with applications to world stock indices.

Science.gov (United States)

Wang, Duan; Podobnik, Boris; Horvatić, Davor; Stanley, H Eugene

2011-04-01

We propose a modified time lag random matrix theory in order to study time-lag cross correlations in multiple time series. We apply the method to 48 world indices, one for each of 48 different countries. We find long-range power-law cross correlations in the absolute values of returns that quantify risk, and find that they decay much more slowly than cross correlations between the returns. The magnitude of the cross correlations constitutes "bad news" for international investment managers who may believe that risk is reduced by diversifying across countries. We find that when a market shock is transmitted around the world, the risk decays very slowly. We explain these time-lag cross correlations by introducing a global factor model (GFM) in which all index returns fluctuate in response to a single global factor. For each pair of individual time series of returns, the cross correlations between returns (or magnitudes) can be modeled with the autocorrelations of the global factor returns (or magnitudes). We estimate the global factor using principal component analysis, which minimizes the variance of the residuals after removing the global trend. Using random matrix theory, a significant fraction of the world index cross correlations can be explained by the global factor, which supports the utility of the GFM. We demonstrate applications of the GFM in forecasting risks at the world level, and in finding uncorrelated individual indices. We find ten indices that are practically uncorrelated with the global factor and with the remainder of the world indices, which is relevant information for world managers in reducing their portfolio risk. Finally, we argue that this general method can be applied to a wide range of phenomena in which time series are measured, ranging from seismology and physiology to atmospheric geophysics.
Quantifying and modeling long-range cross correlations in multiple time series with applications to world stock indices

Science.gov (United States)

Wang, Duan; Podobnik, Boris; Horvatić, Davor; Stanley, H. Eugene

2011-04-01

We propose a modified time lag random matrix theory in order to study time-lag cross correlations in multiple time series. We apply the method to 48 world indices, one for each of 48 different countries. We find long-range power-law cross correlations in the absolute values of returns that quantify risk, and find that they decay much more slowly than cross correlations between the returns. The magnitude of the cross correlations constitutes “bad news” for international investment managers who may believe that risk is reduced by diversifying across countries. We find that when a market shock is transmitted around the world, the risk decays very slowly. We explain these time-lag cross correlations by introducing a global factor model (GFM) in which all index returns fluctuate in response to a single global factor. For each pair of individual time series of returns, the cross correlations between returns (or magnitudes) can be modeled with the autocorrelations of the global factor returns (or magnitudes). We estimate the global factor using principal component analysis, which minimizes the variance of the residuals after removing the global trend. Using random matrix theory, a significant fraction of the world index cross correlations can be explained by the global factor, which supports the utility of the GFM. We demonstrate applications of the GFM in forecasting risks at the world level, and in finding uncorrelated individual indices. We find ten indices that are practically uncorrelated with the global factor and with the remainder of the world indices, which is relevant information for world managers in reducing their portfolio risk. Finally, we argue that this general method can be applied to a wide range of phenomena in which time series are measured, ranging from seismology and physiology to atmospheric geophysics.
Anti-correlated cortical networks arise from spontaneous neuronal dynamics at slow timescales.

Science.gov (United States)

Kodama, Nathan X; Feng, Tianyi; Ullett, James J; Chiel, Hillel J; Sivakumar, Siddharth S; Galán, Roberto F

2018-01-12

In the highly interconnected architectures of the cerebral cortex, recurrent intracortical loops disproportionately outnumber thalamo-cortical inputs. These networks are also capable of generating neuronal activity without feedforward sensory drive. It is unknown, however, what spatiotemporal patterns may be solely attributed to intrinsic connections of the local cortical network. Using high-density microelectrode arrays, here we show that in the isolated, primary somatosensory cortex of mice, neuronal firing fluctuates on timescales from milliseconds to tens of seconds. Slower firing fluctuations reveal two spatially distinct neuronal ensembles, which correspond to superficial and deeper layers. These ensembles are anti-correlated: when one fires more, the other fires less and vice versa. This interplay is clearest at timescales of several seconds and is therefore consistent with shifts between active sensing and anticipatory behavioral states in mice.
Anti-correlated spectral motion in bisphthalocyanines: evidence for vibrational modulation of electronic mixing.

Science.gov (United States)

Prall, Bradley S; Parkinson, Dilworth Y; Ishikawa, Naoto; Fleming, Graham R

2005-12-08

We exploit a coherently excited nuclear wave packet to study nuclear motion modulation of electronic structure in a metal bridged phthalocyanine dimer, lutetium bisphthalocyanine, which displays two visible absorption bands. We find that the nuclear coordinate influences the energies of the underlying exciton and charge resonance states as well as their interaction; the interplay of the various couplings creates unusual anti-correlated spectral motion in the two bands. Excited state relaxation dynamics are the same regardless of which transition is pumped, with decay time constants of 1.5 and 11 ps. The dynamics are analyzed using a three-state kinetic model after relaxation from one or two additional states faster than the experimental time resolution of 50-100 fs.

Effects of signal modulation and coloured cross-correlation of coloured noises on the diffusion of a harmonic oscillator

Institute of Scientific and Technical Information of China (English)

Liu Li; Zhang Liang-Ying; Cao Li

2009-01-01

The diffusion in a harmonic oscillator driven by coloured noises ζ(t) and η(t) with coloured cross-correlation in which one of the noises is modulated by a biased periodic signal is investigated. The exact expression of diffusion coefficient d as a function of noise parameter, signal parameter, and oscillator frequency is derived. The findings in this paper are as follows. 1) The curves of d versus noise intensity D and d versus noises cross-correlation time τ_3 exist as two different phases. The transition between the two phases arises from the change of the cross-correlation coefficient λ of the two Orustein-Uhlenbeck (O-U) noises. 2) Changing the value of τ3, the curves of d versus Q, the intensity of colored noise that is modulated by the signal, can transform from a phase having a minimum to a monotonic phase. 3)Changing the value of signal amplitude A, d versus Q curves can transform from a phase having a minimum to a monotonic phase. The above-mentioned results demonstrate that a like noise-induced transition appears in the model.
Effects of signal modulation and coloured cross-correlation of coloured noises on the diffusion of a harmonic oscillator

International Nuclear Information System (INIS)

Li, Liu; Li, Cao; Liang-Ying, Zhang

2009-01-01

The diffusion in a harmonic oscillator driven by coloured noises ζ(t) and η(t) with coloured cross-correlation in which one of the noises is modulated by a biased periodic signal is investigated. The exact expression of diffusion coefficient d as a function of noise parameter, signal parameter, and oscillator frequency is derived. The findings in this paper are as follows. 1) The curves of d versus noise intensity D and d versus noises cross-correlation time τ 3 exist as two different phases. The transition between the two phases arises from the change of the cross-correlation coefficient λ of the two Ornstein–Uhlenbeck (O-U) noises. 2) Changing the value of τ 3 , the curves of d versus Q, the intensity of colored noise that is modulated by the signal, can transform from a phase having a minimum to a monotonic phase. 3) Changing the value of signal amplitude A, d versus Q curves can transform from a phase having a minimum to a monotonic phase. The above-mentioned results demonstrate that a like noise-induced transition appears in the model. (general)
Anti-Inflammatory Action of an Antimicrobial Model Peptide That Suppresses the TRIF-Dependent Signaling Pathway via Inhibition of Toll-Like Receptor 4 Endocytosis in Lipopolysaccharide-Stimulated Macrophages.

Directory of Open Access Journals (Sweden)

Do-Wan Shim

Full Text Available Antimicrobial peptides (AMPs, also called host defense peptides, particularly those with amphipathic helical structures, are emerging as target molecules for therapeutic development due to their immunomodulatory properties. Although the antimicrobial activity of AMPs is known to be exerted primarily by permeation of the bacterial membrane, the mechanism underlying its anti-inflammatory activity remains to be elucidated. We report potent anti-inflammatory activity of WALK11.3, an antimicrobial model peptide with an amphipathic helical conformation, in lipopolysaccharide (LPS-stimulated RAW264.7 cells. This peptide inhibited the expression of inflammatory mediators, including nitric oxide, COX-2, IL-1β, IL-6, INF-β, and TNF-α. Although WALK11.3 did not exert a major effect on all downstream signaling in the MyD88-dependent pathway, toll-like receptor 4 (TLR4- mediated pro-inflammatory signals were markedly attenuated in the TRIF-dependent pathway due to inhibition of the phosphorylation of STAT1 by attenuation of IRF3 phosphorylation. WALK11.3 specifically inhibited the endocytosis of TLR4, which is essential for triggering TRIF-mediated signaling in macrophage cells. Hence, we suggest that specific interference with TLR4 endocytosis could be one of the major modes of the anti-inflammatory action of AMPs. Our designed WALK11 peptides, which possess both antimicrobial and anti-inflammatory activities, may be promising molecules for the development of therapies for infectious inflammation.
Diabetes alters activation and repression of pro- and anti- inflammatory signalling pathways in the vasculature

Directory of Open Access Journals (Sweden)

Elyse eDi Marco

2013-06-01

Full Text Available A central mechanism driving vascular disease in diabetes is immune cell-mediated inflammation. In diabetes, enhanced oxidation and glycation of macromolecules, such as lipoproteins, insults the endothelium and activates both innate and adaptive arms of the immune system by generating new antigens for presentation to adaptive immune cells. Chronic inflammation of the endothelium in diabetes leads to continuous infiltration and accumulation of leukocytes at sites of endothelial cell injury. We will describe the central role of the macrophage as a source of signalling molecules and damaging by-products which activate infiltrating lymphocytes in the tissue and contribute to the pro-oxidant and pro-inflammatory micro-environment. An important aspect to be considered is the diabetes- associated defects in the immune system, such as fewer or dysfunctional athero-protective leukocyte subsets in the diabetic lesion compared to non-diabetic lesions. This review will discuss the key pro-inflammatory signalling pathways responsible for leukocyte recruitment and activation in the injured vessel, with particular focus on pro- and anti-inflammatory pathways aberrantly activated or repressed in diabetes. We aim to describe the interaction between advanced glycation end products (AGEs and their principle receptor RAGE, Angiotensin II (Ang II and the Ang II type 1 receptor (AT1R, in addition to reactive oxygen species (ROS production by NADPH oxidase (Nox enzymes that are relevant to vascular and immune cell function in the context of diabetic vasculopathy. Furthermore, we will touch on recent advances in epigenetic medicine that have revealed high glucose-mediated changes in the transcription of genes with known pro-inflammatory downstream targets. Finally, novel anti-atherosclerosis strategies that target the vascular immune interface will be explored; such as vaccination against modified LDL and pharmacological inhibition of ROS producing enzymes.
Quantifying signal changes in nano-wire based biosensors

DEFF Research Database (Denmark)

De Vico, Luca; Sørensen, Martin Hedegård; Iversen, Lars

2011-01-01

In this work, we present a computational methodology for predicting the change in signal (conductance sensitivity) of a nano-BioFET sensor (a sensor based on a biomolecule binding another biomolecule attached to a nano-wire field effect transistor) upon binding its target molecule. The methodolog...
A novel coefficient for detecting and quantifying asymmetry of California electricity market based on asymmetric detrended cross-correlation analysis.

Science.gov (United States)

Wang, Fang

2016-06-01

In order to detect and quantify asymmetry of two time series, a novel cross-correlation coefficient is proposed based on recent asymmetric detrended cross-correlation analysis (A-DXA), which we called A-DXA coefficient. The A-DXA coefficient, as an important extension of DXA coefficient ρDXA, contains two directional asymmetric cross-correlated indexes, describing upwards and downwards asymmetric cross-correlations, respectively. By using the information of directional covariance function of two time series and directional variance function of each series itself instead of power-law between the covariance function and time scale, the proposed A-DXA coefficient can well detect asymmetry between the two series no matter whether the cross-correlation is significant or not. By means of the proposed A-DXA coefficient conducted over the asymmetry for California electricity market, we found that the asymmetry between the prices and loads is not significant for daily average data in 1999 yr market (before electricity crisis) but extremely significant for those in 2000 yr market (during the crisis). To further uncover the difference of asymmetry between the years 1999 and 2000, a modified H statistic (MH) and ΔMH statistic are proposed. One of the present contributions is that the high MH values calculated for hourly data exist in majority months in 2000 market. Another important conclusion is that the cross-correlation with downwards dominates over the whole 1999 yr in contrast to the cross-correlation with upwards dominates over the 2000 yr.
A novel coefficient for detecting and quantifying asymmetry of California electricity market based on asymmetric detrended cross-correlation analysis

Science.gov (United States)

Wang, Fang

2016-06-01

In order to detect and quantify asymmetry of two time series, a novel cross-correlation coefficient is proposed based on recent asymmetric detrended cross-correlation analysis (A-DXA), which we called A-DXA coefficient. The A-DXA coefficient, as an important extension of DXA coefficient ρ D X A , contains two directional asymmetric cross-correlated indexes, describing upwards and downwards asymmetric cross-correlations, respectively. By using the information of directional covariance function of two time series and directional variance function of each series itself instead of power-law between the covariance function and time scale, the proposed A-DXA coefficient can well detect asymmetry between the two series no matter whether the cross-correlation is significant or not. By means of the proposed A-DXA coefficient conducted over the asymmetry for California electricity market, we found that the asymmetry between the prices and loads is not significant for daily average data in 1999 yr market (before electricity crisis) but extremely significant for those in 2000 yr market (during the crisis). To further uncover the difference of asymmetry between the years 1999 and 2000, a modified H statistic (MH) and ΔMH statistic are proposed. One of the present contributions is that the high MH values calculated for hourly data exist in majority months in 2000 market. Another important conclusion is that the cross-correlation with downwards dominates over the whole 1999 yr in contrast to the cross-correlation with upwards dominates over the 2000 yr.
Quantifying the strength of quorum sensing crosstalk within microbial communities.

Directory of Open Access Journals (Sweden)

Kalinga Pavan T Silva

2017-10-01

Full Text Available In multispecies microbial communities, the exchange of signals such as acyl-homoserine lactones (AHL enables communication within and between species of Gram-negative bacteria. This process, commonly known as quorum sensing, aids in the regulation of genes crucial for the survival of species within heterogeneous populations of microbes. Although signal exchange was studied extensively in well-mixed environments, less is known about the consequences of crosstalk in spatially distributed mixtures of species. Here, signaling dynamics were measured in a spatially distributed system containing multiple strains utilizing homologous signaling systems. Crosstalk between strains containing the lux, las and rhl AHL-receptor circuits was quantified. In a distributed population of microbes, the impact of community composition on spatio-temporal dynamics was characterized and compared to simulation results using a modified reaction-diffusion model. After introducing a single term to account for crosstalk between each pair of signals, the model was able to reproduce the activation patterns observed in experiments. We quantified the robustness of signal propagation in the presence of interacting signals, finding that signaling dynamics are largely robust to interference. The ability of several wild isolates to participate in AHL-mediated signaling was investigated, revealing distinct signatures of crosstalk for each species. Our results present a route to characterize crosstalk between species and predict systems-level signaling dynamics in multispecies communities.
Notch1 and 4 Signaling Responds to an Increasing Vascular Wall Shear Stress in a Rat Model of Arteriovenous Malformations

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Jian Tu

2014-01-01

Full Text Available Notch signaling is suggested to promote the development and maintenance of cerebral arteriovenous malformations (AVMs, and an increasing wall shear stress (WSS contributes to AVM rupture. Little is known about whether WSS impacts Notch signaling, which is important for understanding the angiogenesis of AVMs. WSS was measured in arteriovenous fistulas (AVF surgically created in 96 rats at different time points over a period of 84 days. The expression of Notch receptors 1 and 4 and their ligands, Delta1 and 4, Jagged1, and Notch downstream gene target Hes1 was quantified in “nidus” vessels. The interaction events between Notch receptors and their ligands were quantified using proximity ligation assay. There was a positive correlation between WSS and time (r=0.97; P<0.001. The expression of Notch receptors and their ligands was upregulated following AVF formation. There was a positive correlation between time and the number of interactions between Notch receptors and their ligands aftre AVF formation (r=0.62, P<0.05 and a positive correlation between WSS and the number of interactions between Notch receptors and their ligands (r=0.87, P<0.005. In conclusion, an increasing WSS may contribute to the angiogenesis of AVMs by activation of Notch signaling.
Quantifying antiviral activity optimizes drug combinations against hepatitis C virus infection

Energy Technology Data Exchange (ETDEWEB)

Koizumi, Yoshiki [School of Medicine, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Ishikawa, Japan; Nakajim, Syo [Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan; Department of Applied Biological Sciences, Faculty of Science and Technology, Tokyo University of Sciences, Chiba, J; Ohash, Hirofumi [Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan: Department of Applied Biological Sciences, Faculty of Science and Technology, Tokyo University of Sciences, Chiba, J; Tanaka, Yasuhito [Department of Virology and Liver Unit, Nagoya City University Graduate School of Medicinal Sciences, Nagoya, Japan; Wakita, Takaji [Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan; Perelson, Alan S. [Los Alamos National Laboratory; Iwami, Shingo [Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan: PRESTO, JST, Saitama, Japan: CREST, JST, Saitama, Japan; Watashi, Koichi [Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan: Department of Applied Biological Sciences, Faculty of Science and Technology, Tokyo University of Sciences, Chiba, J

2016-03-21

Cell culture study combing a mathematical model and computer simulation quantifies the anti-hepatitis C virus drug efficacy at any concentrations and any combinations in preclinical settings, and can obtain rich basic evidences for selecting optimal treatments prior to costly clinical trials.
Weak correlations between hemodynamic signals and ongoing neural activity during the resting state

Science.gov (United States)

Winder, Aaron T.; Echagarruga, Christina; Zhang, Qingguang; Drew, Patrick J.

2017-01-01

Spontaneous fluctuations in hemodynamic signals in the absence of a task or overt stimulation are used to infer neural activity. We tested this coupling by simultaneously measuring neural activity and changes in cerebral blood volume (CBV) in the somatosensory cortex of awake, head-fixed mice during periods of true rest, and during whisker stimulation and volitional whisking. Here we show that neurovascular coupling was similar across states, and large spontaneous CBV changes in the absence of sensory input were driven by volitional whisker and body movements. Hemodynamic signals during periods of rest were weakly correlated with neural activity. Spontaneous fluctuations in CBV and vessel diameter persisted when local neural spiking and glutamatergic input was blocked, and during blockade of noradrenergic receptors, suggesting a non-neuronal origin for spontaneous CBV fluctuations. Spontaneous hemodynamic signals reflect a combination of behavior, local neural activity, and putatively non-neural processes. PMID:29184204
Anti-Stokes Luminescence in High Quality Quantum Wells

Science.gov (United States)

Vinattieri, A.; Bogani, F.; Miotto, A.; Ceccherini, S.

1997-11-01

We present a detailed investigation of the anti-Stokes (AS) luminescence which originates from exciton recombination when below gap excitation is used, in a set of high quality quantum well structures. We observe strong excitonic resonances in the AS signal as measured from photoluminescence and photoluminescence excitation spectra. We demonstrate that neither the electromagnetic coupling between the wells nor the morphological disorder can explain this up-conversion effect. Time-resolved luminescence data after ps excitation and fs correlation spectroscopy results provide clear evidence of the occurrence of a two-step absorption which is assisted by the exciton population resonantly excited by the first photon.
Quantified terminal ileal motility during MR enterography as a potential biomarker of Crohn's disease activity: a preliminary study

International Nuclear Information System (INIS)

Menys, Alex; Atkinson, David; Ahmed, Asia; Punwani, Shonit; Halligan, Steve; Odille, Freddy; Novelli, Marco; Rodriguez-Justo, Manuel; Proctor, Ian; Taylor, Stuart A.

2012-01-01

To compare quantified terminal ileal (TI) motility during MR enterography (MRE) with histopathological severity of acute inflammation in Crohn's disease. A total of 28 Crohn's patients underwent MRE and endoscopic TI biopsy. Axial and coronal TrueFISP, HASTE and post-gadolinium VIBE images were supplemented by multiple coronal TrueFISP cine motility sequences through the small bowel volume. TI motility index (MI) was quantified using validated software; an acute inflammation score (eAIS; 0-6) was assigned to the biopsy. Two observers qualitatively scored mural thickness, T2 signal, contrast enhancement and perimural oedema (0-3) to produce an activity score (aMRIs) based on anatomical MRI. The association among the MI, eAIS and aMRIs was tested using Spearman's rank correlation. Wilcoxon rank sum test compared motility in subjects with and without histopathological inflammation. Mean MI and mean eAIS were 0.27 (range 0.06-0.55) and 1.5 (range 0-5), respectively. There was a significant difference in MI between non-inflamed (mean 0.37, range 0.13-0.55) and inflamed (mean 0.19, range 0.06-0.44) TI, P = 0.002, and a significant negative correlation between MI and both eAIS (Rho = -0.52, P = 0.005) and aMRIs (R = -0.7, P < 0.001). Quantified TI motility negatively correlates with histopathological measures of disease activity and existing anatomical MRI activity biomarkers. (orig.)
In vitro anti-inflammatory and anti-cancer activities of Cuscuta reflexa Roxb.

Science.gov (United States)

Suresh, V; Sruthi, V; Padmaja, B; Asha, V V

2011-04-12

To determine anti-inflammatory and anti-cancer activities of Cuscuta reflexa in cell lines (in vitro). Anti-inflammatory activity of the water extract was analysed in vitro using lipopolysaccharide (LPS) induced inflammatory reactions in murine macrophage cell line RAW264.7. The expression of COX-2 and TNF-α genes involved in inflammation was analysed by SQ RT-PCR. EMSA was conducted to analyse the influence of the extract on NF-κB signalling. Anti-cancer activity was analysed on Hep3B cells by MTT assay, DAPI staining, annexin V staining and SQ-RT PCR analysis of BAX, Bcl-2, p53 and survivin. The extract down regulated LPS induced over expression of TNF-α and COX-2 in RAW264.7 cells; blocked NF-κB binding to its motifs and induced apoptosis in Hep3B cells as evidenced from MTT, DAPI staining and annexin V staining assays. The extract up regulated pro-apoptotic factors BAX and p53, and down regulated anti-apoptotic factors Bcl-2 and survivin. The study showed that Cuscuta reflexa inhibits LPS induced inflammatory responses in RAW264.7 cells through interplay of TNF-α, COX-2 and NF-κB signalling. It induced apoptosis in Hep3B cells through the up regulation of p53, BAX and down regulation of Bcl-2 and survivin. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Anti-VEGF drugs: evidence for effectiveness

OpenAIRE

Evans, Jennifer; Virgili, Gianni

2014-01-01

Anti-vascular endothelial growth factors (anti-VEGF) are targeted biological drugs (e.g. monoclonal antibodies) that prevent the growth of new vessels by inhibiting VEGF. VEGF is a cytokine (cell-signalling protein) that promotes the growth of, and leakage from, new vessels. Currently there are three anti-VEGF drugs licensed for use in eye disease: pegaptanib, aflibercept, ranibizumab and one that is not licensed but is commonly used off-label (bevacizumab).
Correlations in Werner States

International Nuclear Information System (INIS)

Luo Shunlong; Li Nan

2008-01-01

Werner states are paradigmatic examples of quantum states and play an innovative role in quantum information theory. In investigating the correlating capability of Werner states, we find the curious phenomenon that quantum correlations, as quantified by the entanglement of formation, may exceed the total correlations, as measured by the quantum mutual information. Consequently, though the entanglement of formation is so widely used in quantifying entanglement, it cannot be interpreted as a consistent measure of quantum correlations per se if we accept the folklore that total correlations are measured (or rather upper bounded) by the quantum mutual information.
Quantifying the predictability of diaphragm motion during respiration with a noninvasive external marker

International Nuclear Information System (INIS)

Vedam, S.S.; Kini, V.R.; Keall, P.J.; Ramakrishnan, V.; Mostafavi, H.; Mohan, R.

2003-01-01

The aim of this work was to quantify the ability to predict intrafraction diaphragm motion from an external respiration signal during a course of radiotherapy. The data obtained included diaphragm motion traces from 63 fluoroscopic lung procedures for 5 patients, acquired simultaneously with respiratory motion signals (an infrared camera-based system was used to track abdominal wall motion). During these sessions, the patients were asked to breathe either (i) without instruction, (ii) with audio prompting, or (iii) using visual feedback. A statistical general linear model was formulated to describe the relationship between the respiration signal and diaphragm motion over all sessions and for all breathing training types. The model parameters derived from the first session for each patient were then used to predict the diaphragm motion for subsequent sessions based on the respiration signal. Quantification of the difference between the predicted and actual motion during each session determined our ability to predict diaphragm motion during a course of radiotherapy. This measure of diaphragm motion was also used to estimate clinical target volume (CTV) to planning target volume (PTV) margins for conventional, gated, and proposed four-dimensional (4D) radiotherapy. Results from statistical analysis indicated a strong linear relationship between the respiration signal and diaphragm motion (p<0.001) over all sessions, irrespective of session number (p=0.98) and breathing training type (p=0.19). Using model parameters obtained from the first session, diaphragm motion was predicted in subsequent sessions to within 0.1 cm (1 σ) for gated and 4D radiotherapy. Assuming a 0.4 cm setup error, superior-inferior CTV-PTV margins of 1.1 cm for conventional radiotherapy could be reduced to 0.8 cm for gated and 4D radiotherapy. The diaphragm motion is strongly correlated with the respiration signal obtained from the abdominal wall. This correlation can be used to predict diaphragm
Hedgehog Signaling Inhibitors as Anti-Cancer Agents in Osteosarcoma

International Nuclear Information System (INIS)

Ram Kumar, Ram Mohan; Fuchs, Bruno

2015-01-01

Osteosarcoma is a rare type of cancer associated with a poor clinical outcome. Even though the pathologic characteristics of OS are well established, much remains to be understood, particularly at the molecular signaling level. The molecular mechanisms of osteosarcoma progression and metastases have not yet been fully elucidated and several evolutionary signaling pathways have been found to be linked with osteosarcoma pathogenesis, especially the hedgehog signaling (Hh) pathway. The present review will outline the importance and targeting the hedgehog signaling (Hh) pathway in osteosarcoma tumor biology. Available data also suggest that aberrant Hh signaling has pro-migratory effects and leads to the development of osteoblastic osteosarcoma. Activation of Hh signaling has been observed in osteosarcoma cell lines and also in primary human osteosarcoma specimens. Emerging data suggests that interference with Hh signal transduction by inhibitors may reduce osteosarcoma cell proliferation and tumor growth thereby preventing osteosarcomagenesis. From this perspective, we outline the current state of Hh pathway inhibitors in osteosarcoma. In summary, targeting Hh signaling by inhibitors promise to increase the efficacy of osteosarcoma treatment and improve patient outcome
Analysis of Correlation in MEMS Gyroscope Array and its Influence on Accuracy Improvement for the Combined Angular Rate Signal

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Liang Xue

2018-01-01

Full Text Available Obtaining a correlation factor is a prerequisite for fusing multiple outputs of a mircoelectromechanical system (MEMS gyroscope array and evaluating accuracy improvement. In this paper, a mathematical statistics method is established to analyze and obtain the practical correlation factor of a MEMS gyroscope array, which solves the problem of determining the Kalman filter (KF covariance matrix Q and fusing the multiple gyroscope signals. The working principle and mathematical model of the sensor array fusion is briefly described, and then an optimal estimate of input rate signal is achieved by using of a steady-state KF gain in an off-line estimation approach. Both theoretical analysis and simulation show that the negative correlation factor has a favorable influence on accuracy improvement. Additionally, a four-gyro array system composed of four discrete individual gyroscopes was developed to test the correlation factor and its influence on KF accuracy improvement. The result showed that correlation factors have both positive and negative values; in particular, there exist differences for correlation factor between the different units in the array. The test results also indicated that the Angular Random Walk (ARW of 1.57°/h0.5 and bias drift of 224.2°/h for a single gyroscope were reduced to 0.33°/h0.5 and 47.8°/h with some negative correlation factors existing in the gyroscope array, making a noise reduction factor of about 4.7, which is higher than that of a uncorrelated four-gyro array. The overall accuracy of the combined angular rate signal can be further improved if the negative correlation factors in the gyroscope array become larger.
Investigating correlations of local seismicty with anomalous geoelectrical, hydrogeological and geochemical signals jointly recorded in Basilicata Region (Southern Italy

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M. Mucciarelli

2007-06-01

Full Text Available This paper presents the preliminary results analysing the correlation between local seismicity and geoelectrical, hydrogeological and geochemical signals concomitantly recorded in Basilicata Region, one of the most seismically active areas in Southern Italy. The signals were recorded by two stations: Tito and Tramutola. Tito station measures vertically the Self-Potential field (SP by an array of five no-polarizable electrodes equally spaced with the common electrode at 20 m depth as well as water-level, water-temperature and electrical-conductivity. Tramutola station measures self-potential signals in soil surface, gas flow and water temperature in a thermal-water well, as well as atmospheric barometric pressure and ambient temperature. Correlations were found between the sharp variability of the signals recorded by both stations and the seismic sequence that occurred on September 3 to 4, 2004, allowing us to link these anomalies with the tectonic evolution of the investigated area.

Anti-Inflammatory Effects of 81 Chinese Herb Extracts and Their Correlation with the Characteristics of Traditional Chinese Medicine

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Chang-Liang Chen

2014-01-01

Full Text Available Inducible nitrogen oxide synthase (iNOS is the primary contributor of the overproduction of nitric oxide and its inhibitors have been actively sought as effective anti-inflammatory agents. In this study, we prepared 70% ethanol extracts from 81 Chinese herbs. These extracts were subsequently evaluated for their effect on nitrogen oxide (NO production and cell growth in LPS/IFNγ-costimulated and unstimulated murine macrophage RAW264.7 cells by Griess reaction and MTT assay. Extracts of Daphne genkwa Sieb.et Zucc, Caesalpinia sappan L., Iles pubescens Hook.et Arn, Forsythia suspensa (Thunb. Vahl, Zingiber officinale Rosc, Inula japonica Thunb., and Ligusticum chuanxiong Hort markedly inhibited NO production (inhibition > 90% at 100 μg/mL. Among active extracts (inhibition > 50% at 100 μg/mL, Rubia cordifolia L., Glycyrrhiza glabra L., Iles pubescens Hook.et Arn, Nigella glandulifera Freyn et Sint, Pueraria lobata (Willd. Ohwi, and Scutellaria barbata D. Don displayed no cytotoxicity to unstimulated RAW246.7 cells while increasing the growth of LPS/IFNγ-costimulated cells. By analyzing the correlation between their activities and their Traditional Chinese Medicine (TCM characteristics, herbs with pungent flavor displayed potent anti-inflammatory capability. Our study provides a series of potential anti-inflammatory herbs and suggests that herbs with pungent flavor are candidates of effective anti-inflammatory agents.
Saturated excitation of Fluorescence to quantify excitation enhancement in aperture antennas

KAUST Repository

Aouani, Heykel

2012-07-23

Fluorescence spectroscopy is widely used to probe the electromagnetic intensity amplification on optical antennas, yet measuring the excitation intensity amplification is a challenge, as the detected fluorescence signal is an intricate combination of excitation and emission. Here, we describe a novel approach to quantify the electromagnetic amplification in aperture antennas by taking advantage of the intrinsic non linear properties of the fluorescence process. Experimental measurements of the fundamental f and second harmonic 2f amplitudes of the fluorescence signal upon excitation modulation are used to quantify the electromagnetic intensity amplification with plasmonic aperture antennas. © 2012 Optical Society of America.
Saturated excitation of Fluorescence to quantify excitation enhancement in aperture antennas

KAUST Repository

Aouani, Heykel; Hostein, Richard; Mahboub, Oussama; Devaux, Eloï se; Rigneault, Hervé ; Ebbesen, Thomas W.; Wenger, Jé rô me

2012-01-01

Fluorescence spectroscopy is widely used to probe the electromagnetic intensity amplification on optical antennas, yet measuring the excitation intensity amplification is a challenge, as the detected fluorescence signal is an intricate combination of excitation and emission. Here, we describe a novel approach to quantify the electromagnetic amplification in aperture antennas by taking advantage of the intrinsic non linear properties of the fluorescence process. Experimental measurements of the fundamental f and second harmonic 2f amplitudes of the fluorescence signal upon excitation modulation are used to quantify the electromagnetic intensity amplification with plasmonic aperture antennas. © 2012 Optical Society of America.
Dynamic brain glucose metabolism identifies anti-correlated cortical-cerebellar networks at rest.

Science.gov (United States)

Tomasi, Dardo G; Shokri-Kojori, Ehsan; Wiers, Corinde E; Kim, Sunny W; Demiral, Şukru B; Cabrera, Elizabeth A; Lindgren, Elsa; Miller, Gregg; Wang, Gene-Jack; Volkow, Nora D

2017-12-01

It remains unclear whether resting state functional magnetic resonance imaging (rfMRI) networks are associated with underlying synchrony in energy demand, as measured by dynamic 2-deoxy-2-[ 18 F]fluoroglucose (FDG) positron emission tomography (PET). We measured absolute glucose metabolism, temporal metabolic connectivity (t-MC) and rfMRI patterns in 53 healthy participants at rest. Twenty-two rfMRI networks emerged from group independent component analysis (gICA). In contrast, only two anti-correlated t-MC emerged from FDG-PET time series using gICA or seed-voxel correlations; one included frontal, parietal and temporal cortices, the other included the cerebellum and medial temporal regions. Whereas cerebellum, thalamus, globus pallidus and calcarine cortex arose as the strongest t-MC hubs, the precuneus and visual cortex arose as the strongest rfMRI hubs. The strength of the t-MC linearly increased with the metabolic rate of glucose suggesting that t-MC measures are strongly associated with the energy demand of the brain tissue, and could reflect regional differences in glucose metabolism, counterbalanced metabolic network demand, and/or differential time-varying delivery of FDG. The mismatch between metabolic and functional connectivity patterns computed as a function of time could reflect differences in the temporal characteristics of glucose metabolism as measured with PET-FDG and brain activation as measured with rfMRI.
Anti-Saccharomyces cerevisiae and perinuclear anti-neutrophil cytoplasmic antibodies in coeliac disease before and after gluten-free diet.

Science.gov (United States)

Granito, A; Zauli, D; Muratori, P; Muratori, L; Grassi, A; Bortolotti, R; Petrolini, N; Veronesi, L; Gionchetti, P; Bianchi, F B; Volta, U

2005-04-01

Anti-Saccharomyces cerevisiae and perinuclear anti-neutrophil cytoplasmic autoantibodies are markers of Crohn's disease and ulcerative colitis respectively. To determine the prevalence of anti-S. cerevisiae and perinuclear anti-neutrophil cytoplasmic autoantibodies in a large series of coeliac disease patients before and after gluten free diet, and to correlate anti-S. cerevisiae-positivity with intestinal mucosal damage. One hundred and five consecutive coeliac disease patients and 141 controls (22 ulcerative colitis, 24 Crohn's disease, 30 primary sclerosing cholangitis, 15 postenteritis syndrome, 50 blood donors) were tested for anti-S. cerevisiae by enzyme-linked immunosorbent assay and for perinuclear anti-neutrophil cytoplasmic autoantibodies by indirect immunofluorescence. In coeliac disease anti-S. cerevisiae (immunoglobulin G and/or immunoglobulin A) were slightly less frequent (59%) than in Crohn's disease (75%, P = 0.16) and significantly more frequent than in ulcerative colitis (27%), primary sclerosing cholangitis (30%), postenteritis syndrome (26%) and blood donors (4%) (P = 0.009, P = 0.0002, P = 0.025, P < 0.0001). No correlation was found between anti-S. cerevisiae and degree of mucosal damage. Perinuclear anti-neutrophil cytoplasmic autoantibodies were detected only in one coeliac. After gluten free diet the disappearance of anti-S. cerevisiae-immunoglobulin A (93%) was more frequent than that of immunoglobulin G (17%, P = 0.0001); perinuclear anti-neutrophil cytoplasmic autoantibodies disappeared in the only coeliac positive at diagnosis. More than half of untreated coeliacs are anti-S. cerevisiae-positive irrespective of the severity of mucosal damage. Differently from immunoglobulin A, anti-S. cerevisiae-immunoglobulin G persisted in more than 80% after gluten free diet. The high prevalence of anti-S. cerevisiae in coeliac disease suggests that they may be the effect of a non-specific immune response in course of chronic small bowel disease.
Anti-tumor and anti-angiogenic ergosterols from Ganoderma lucidum

Science.gov (United States)

Chen, Shaodan; Yong, Tianqiao; Zhang, Yifang; Su, Jiyan; Jiao, Chunwei; Xie, Yizhen

2017-10-01

This study was carried out to isolate chemical constituents from the lipid enriched fraction of Ganoderma lucidum extract and to evaluate their anti-proliferative effect on cancer cell lines and human umbilical vein endothelial cells. Ergosterol derivatives (1-14) were isolated from the lipid enriched fraction of G. lucidum. Their structures were established on the basis of spectroscopic analyses or by comparison of mass and NMR spectral data with those reported previously. Amongst, compound 1 was isolated and identified as a new compound. All the compounds were evaluated for their inhibitory effect on tumor cells and human umbilical vein endothelial cells in vitro. Compounds 9-13 displayed inhibitory activity against two tumor cell lines and human umbilical vein endothelial cells, which indicated that these four compounds had both anti-tumor and anti-angiogenesis activities. Compound 2 had significant selective inhibition against two tumor cell lines, while 3 exhibited selective inhibition against human umbilical vein endothelial cells. The structure–activity relationships for inhibiting human HepG2 cells were revealed by 3D-QASR. Ergosterol content in different parts of the raw material and products of G. lucidum was quantified. This study provides a basis for further development and utilization of ergosterol derivatives as natural nutraceuticals and functional food ingredients, or as source of new potential antitumor or anti-angiogenesis chemotherapy agent.
Expression of BAFF receptors in muscle tissue of myositis patients with anti-Jo-1 or anti-Ro52/anti-Ro60 autoantibodies.

Science.gov (United States)

Kryštůfková, Olga; Barbasso Helmers, Sevim; Venalis, Paulius; Malmström, Vivianne; Lindroos, Eva; Vencovský, Jiří; Lundberg, Ingrid E

2014-10-10

Anti-Jo-1 and anti-Ro52 autoantibodies are common in patients with myositis, but the mechanisms behind their production are not known. Survival of autoantibody-producing cells is dependent on B-cell-activating factor of the tumour necrosis factor family (BAFF). BAFF levels are elevated in serum of anti-Jo-1-positive myositis patients and are influenced by type-I interferon (IFN). IFN-producing cells and BAFF mRNA expression are present in myositis muscle. We investigated expression of the receptors for BAFF in muscle tissue in relation to anti-Jo-1 and anti-Ro52/anti-Ro60 autoantibodies and type-I IFN markers. Muscle biopsies from 23 patients with myositis selected based on autoantibody profile and 7 healthy controls were investigated for expression of BAFF receptor (BAFF-R), B-cell maturation antigen (BCMA) and transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI). Nineteen samples were assessed for plasma (CD138) and B-cell (CD19) markers. The numbers of positive cells per area were compared with the expression of plasmacytoid dendritic cell (pDC) marker blood dendritic cell antigen-2 (BDCA-2) and IFNα/β-inducible myxovirus resistance-1 protein (MX-1). BAFF-R, BCMA and TACI were expressed in five, seven and seven patients, respectively, and more frequently in anti-Jo-1-positive and/or anti-Ro52/anti-Ro60-positive patients compared to controls and to patients without these autoantibodies (P = BAFF-R: 0.007, BCMA: 0.03 and TACI: 0.07). A local association of receptors with B and plasma cells was confirmed by confocal microscopy. The numbers of CD138-positive and BCMA-positive cells were correlated (r = 0.79; P = 0.001). Expression of BDCA-2 correlated with numbers of CD138-positive cells and marginally with BCMA-positive cells (r = 0.54 and 0.42, respectively; P = 0.04 and 0.06, respectively). There was a borderline correlation between the numbers of positively stained TACI cells and MX-1 areas (r = 0.38, P = 0.08). The expression
In silico design of anti-atherogenic biomaterials.

Science.gov (United States)

Lewis, Daniel R; Kholodovych, Vladyslav; Tomasini, Michael D; Abdelhamid, Dalia; Petersen, Latrisha K; Welsh, William J; Uhrich, Kathryn E; Moghe, Prabhas V

2013-10-01

Atherogenesis, the uncontrolled deposition of modified lipoproteins in inflamed arteries, serves as a focal trigger of cardiovascular disease (CVD). Polymeric biomaterials have been envisioned to counteract atherogenesis based on their ability to repress scavenger mediated uptake of oxidized lipoprotein (oxLDL) in macrophages. Following the conceptualization in our laboratories of a new library of amphiphilic macromolecules (AMs), assembled from sugar backbones, aliphatic chains and poly(ethylene glycol) tails, a more rational approach is necessary to parse the diverse features such as charge, hydrophobicity, sugar composition and stereochemistry. In this study, we advance a computational biomaterials design approach to screen and elucidate anti-atherogenic biomaterials with high efficacy. AMs were quantified in terms of not only 1D (molecular formula) and 2D (molecular connectivity) descriptors, but also new 3D (molecular geometry) descriptors of AMs modeled by coarse-grained molecular dynamics (MD) followed by all-atom MD simulations. Quantitative structure-activity relationship (QSAR) models for anti-atherogenic activity were then constructed by screening a total of 1164 descriptors against the corresponding, experimentally measured potency of AM inhibition of oxLDL uptake in human monocyte-derived macrophages. Five key descriptors were identified to provide a strong linear correlation between the predicted and observed anti-atherogenic activity values, and were then used to correctly forecast the efficacy of three newly designed AMs. Thus, a new ligand-based drug design framework was successfully adapted to computationally screen and design biomaterials with cardiovascular therapeutic properties. Copyright © 2013 Elsevier Ltd. All rights reserved.
Generalized Wavelet Fisher’s Information of 1/fα Signals

Directory of Open Access Journals (Sweden)

Julio Ramírez-Pacheco

2015-01-01

Full Text Available This paper defines the generalized wavelet Fisher information of parameter q. This information measure is obtained by generalizing the time-domain definition of Fisher’s information of Furuichi to the wavelet domain and allows to quantify smoothness and correlation, among other signals characteristics. Closed-form expressions of generalized wavelet Fisher information for 1/fα signals are determined and a detailed discussion of their properties, characteristics and their relationship with wavelet q-Fisher information are given. Information planes of 1/f signals Fisher information are obtained and, based on these, potential applications are highlighted. Finally, generalized wavelet Fisher information is applied to the problem of detecting and locating weak structural breaks in stationary 1/f signals, particularly for fractional Gaussian noise series. It is shown that by using a joint Fisher/F-Statistic procedure, significant improvements in time and accuracy are achieved in comparison with the sole application of the F-statistic.
Decoding visual object categories from temporal correlations of ECoG signals.

Science.gov (United States)

Majima, Kei; Matsuo, Takeshi; Kawasaki, Keisuke; Kawai, Kensuke; Saito, Nobuhito; Hasegawa, Isao; Kamitani, Yukiyasu

2014-04-15

How visual object categories are represented in the brain is one of the key questions in neuroscience. Studies on low-level visual features have shown that relative timings or phases of neural activity between multiple brain locations encode information. However, whether such temporal patterns of neural activity are used in the representation of visual objects is unknown. Here, we examined whether and how visual object categories could be predicted (or decoded) from temporal patterns of electrocorticographic (ECoG) signals from the temporal cortex in five patients with epilepsy. We used temporal correlations between electrodes as input features, and compared the decoding performance with features defined by spectral power and phase from individual electrodes. While using power or phase alone, the decoding accuracy was significantly better than chance, correlations alone or those combined with power outperformed other features. Decoding performance with correlations was degraded by shuffling the order of trials of the same category in each electrode, indicating that the relative time series between electrodes in each trial is critical. Analysis using a sliding time window revealed that decoding performance with correlations began to rise earlier than that with power. This earlier increase in performance was replicated by a model using phase differences to encode categories. These results suggest that activity patterns arising from interactions between multiple neuronal units carry additional information on visual object categories. Copyright © 2013 Elsevier Inc. All rights reserved.
Misfit-guided self-organization of anti-correlated Ge quantum dot arrays on Si nanowires

Science.gov (United States)

Kwon, Soonshin; Chen, Zack C.Y.; Kim, Ji-Hun; Xiang, Jie

2012-01-01

Misfit-strain guided growth of periodic quantum dot (QD) arrays in planar thin film epitaxy has been a popular nanostructure fabrication method. Engineering misfit-guided QD growth on a nanoscale substrate such as the small curvature surface of a nanowire represents a new approach to self-organized nanostructure preparation. Perhaps more profoundly, the periodic stress underlying each QD and the resulting modulation of electro-optical properties inside the nanowire backbone promise to provide a new platform for novel mechano-electronic, thermoelectronic, and optoelectronic devices. Herein, we report a first experimental demonstration of self-organized and self-limited growth of coherent, periodic Ge QDs on a one dimensional Si nanowire substrate. Systematic characterizations reveal several distinctively different modes of Ge QD ordering on the Si nanowire substrate depending on the core diameter. In particular, Ge QD arrays on Si nanowires of around 20 nm diameter predominantly exhibit an anti-correlated pattern whose wavelength agrees with theoretical predictions. The correlated pattern can be attributed to propagation and correlation of misfit strain across the diameter of the thin nanowire substrate. The QD array growth is self-limited as the wavelength of the QDs remains unchanged even after prolonged Ge deposition. Furthermore, we demonstrate a direct kinetic transformation from a uniform Ge shell layer to discrete QD arrays by a post-growth annealing process. PMID:22889063
A quark-gluon plasma search in anti p-p at √s=1.8 TeV

International Nuclear Information System (INIS)

Turkot, F.; Alexopoulos, T.; Erwin, A.R.; Findeisen, C.; Nelson, K.; Thompson, M.A.; Banerjee, S.; Beerv, P.D.; Bishop, J.; Biswas, N.N.; Kenney, V.P.; LoSecco, J.M.; McManus, A.P.; Piekarz, J.; Stampke, S.R.; Zuong, H.; Bhat, P.; Carter, T.; Goshaw, A.T.; Loomis, C.; Oh, S.H.; Robertson, W.R.; Walker, W.D.; Wesson, D.K.; DeCarlo, V.

1991-01-01

We present a survey of the recent results of E-735 in its search for QGP signals at the Fermilab Collider. The basic data are the inclusive P t distributions of centrally produced π, K, anti p and Λ 0 as a function of total charged multiplicity in the collision; the variation of [P t ] and particle ratios are derived. Preliminary results on π-π correlations and inclusive photon production are also presented. (orig.)
Quantified terminal ileal motility during MR enterography as a potential biomarker of Crohn's disease activity: a preliminary study

Energy Technology Data Exchange (ETDEWEB)

Menys, Alex; Atkinson, David; Ahmed, Asia; Punwani, Shonit; Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); Odille, Freddy [INSERM U947, Nancy University, Nancy (France); Novelli, Marco; Rodriguez-Justo, Manuel; Proctor, Ian [University College London, Histopathology, London (United Kingdom); Taylor, Stuart A. [University College London, Centre for Medical Imaging, London (United Kingdom); University College London Hospital, Department of Specialist Radiology, London (United Kingdom)

2012-11-15

To compare quantified terminal ileal (TI) motility during MR enterography (MRE) with histopathological severity of acute inflammation in Crohn's disease. A total of 28 Crohn's patients underwent MRE and endoscopic TI biopsy. Axial and coronal TrueFISP, HASTE and post-gadolinium VIBE images were supplemented by multiple coronal TrueFISP cine motility sequences through the small bowel volume. TI motility index (MI) was quantified using validated software; an acute inflammation score (eAIS; 0-6) was assigned to the biopsy. Two observers qualitatively scored mural thickness, T2 signal, contrast enhancement and perimural oedema (0-3) to produce an activity score (aMRIs) based on anatomical MRI. The association among the MI, eAIS and aMRIs was tested using Spearman's rank correlation. Wilcoxon rank sum test compared motility in subjects with and without histopathological inflammation. Mean MI and mean eAIS were 0.27 (range 0.06-0.55) and 1.5 (range 0-5), respectively. There was a significant difference in MI between non-inflamed (mean 0.37, range 0.13-0.55) and inflamed (mean 0.19, range 0.06-0.44) TI, P = 0.002, and a significant negative correlation between MI and both eAIS (Rho = -0.52, P = 0.005) and aMRIs (R = -0.7, P < 0.001). Quantified TI motility negatively correlates with histopathological measures of disease activity and existing anatomical MRI activity biomarkers. (orig.)
ON THE ANTI-CORRELATION BETWEEN SPECTRAL LINE BROADENING AND INTENSITY IN CORONAL STRUCTURES OBSERVED WITH EIS

International Nuclear Information System (INIS)

Scott, J. T.; Martens, P. C. H.

2011-01-01

The advance in spectral resolution of the Extreme Ultraviolet Imaging (EIS) spectrometer on board Hinode has allowed for more detailed analysis of coronal spectral lines. Large line broadening and blueshifted velocities have been found in the periphery of active region (AR) cores and near the footpoints of coronal loops. This line broadening is yet to be understood. We study the correlation of intensity and line width for entire ARs and sub-regions selected to include coronal features. The results show that although a slight positive correlation can be found when considering whole images, many sub-regions have a negative correlation between intensity and line width. Sections of a coronal loop display some of the largest anti-correlations found for this study with the increased line broadening occurring directly adjacent to the footpoint section of the loop structure, not at the footpoint itself. The broadened lines may be due to a second Doppler-shifted component that is separate from the main emitting feature such as a coronal loop, but related in their excitation. The small size of these features forces the considerations of investigator and instrumental effects. Preliminary analyses are shown that indicate the possibility of a point-spread function that is not azimuthally symmetric and may affect velocity and line profile measurements.
EPPUR SI MUOVE: POSITIONAL AND KINEMATIC CORRELATIONS OF SATELLITE PAIRS IN THE LOW Z UNIVERSE

International Nuclear Information System (INIS)

Ibata, Rodrigo A.; Famaey, Benoit; Martin, Nicolas; Lewis, Geraint F.; Ibata, Neil G.

2015-01-01

We have recently shown that pairs of satellite galaxies located diametrically opposite to each other around their host possess predominantly anti-correlated velocities. This is consistent with a scenario in which ≳50% of satellite galaxies belong to kinematically coherent rotating planar structures. Here we extend this analysis, examining satellites of giant galaxies drawn from an SDSS photometric redshift catalog. We find that there is a ∼17% overabundance (>3σ significance) of candidate satellites at positions diametrically opposite to a spectroscopically confirmed satellite. We show that ΛCDM cosmological simulations do not possess this property when contamination is included. After subtracting contamination, we find ∼2 times more satellites diametrically opposed to a spectroscopically confirmed satellite than at 90° from it, at projected distances ranging from 100 to 150 kpc from the host. This independent analysis thus strongly supports our previous results on anti-correlated velocities. We also find that those satellite pairs with anti-correlated velocities have a strong preference (∼3:1) to align with the major axis of the host whereas those with correlated velocities display the opposite behavior. We finally show that repeating a similar analysis to Ibata et al. with same-side satellites is generally hard to interpret, but is not inconsistent with our previous results when strong quality cuts are applied on the sample. This addresses all of the concerns recently raised by Cautun et al., who did not uncover any flaw in our previous analysis, but may simply have hinted at the physical extent of planar satellite structures by pointing out that the anti-correlation signal weakens at radii >150 kpc. All these unexpected positional and kinematic correlations strongly suggest that a substantial fraction of satellite galaxies are causally linked in their formation and evolution
EPPUR SI MUOVE: POSITIONAL AND KINEMATIC CORRELATIONS OF SATELLITE PAIRS IN THE LOW Z UNIVERSE

Energy Technology Data Exchange (ETDEWEB)

Ibata, Rodrigo A.; Famaey, Benoit; Martin, Nicolas [Observatoire astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France); Lewis, Geraint F. [Sydney Institute of Astronomy, School of Physics A28, University of Sydney, NSW 2006 (Australia); Ibata, Neil G., E-mail: rodrigo.ibata@astro.unistra.fr [Trinity College, Trinity Street, Cambridge, CB2 1TQ (United Kingdom)

2015-05-20

We have recently shown that pairs of satellite galaxies located diametrically opposite to each other around their host possess predominantly anti-correlated velocities. This is consistent with a scenario in which ≳50% of satellite galaxies belong to kinematically coherent rotating planar structures. Here we extend this analysis, examining satellites of giant galaxies drawn from an SDSS photometric redshift catalog. We find that there is a ∼17% overabundance (>3σ significance) of candidate satellites at positions diametrically opposite to a spectroscopically confirmed satellite. We show that ΛCDM cosmological simulations do not possess this property when contamination is included. After subtracting contamination, we find ∼2 times more satellites diametrically opposed to a spectroscopically confirmed satellite than at 90° from it, at projected distances ranging from 100 to 150 kpc from the host. This independent analysis thus strongly supports our previous results on anti-correlated velocities. We also find that those satellite pairs with anti-correlated velocities have a strong preference (∼3:1) to align with the major axis of the host whereas those with correlated velocities display the opposite behavior. We finally show that repeating a similar analysis to Ibata et al. with same-side satellites is generally hard to interpret, but is not inconsistent with our previous results when strong quality cuts are applied on the sample. This addresses all of the concerns recently raised by Cautun et al., who did not uncover any flaw in our previous analysis, but may simply have hinted at the physical extent of planar satellite structures by pointing out that the anti-correlation signal weakens at radii >150 kpc. All these unexpected positional and kinematic correlations strongly suggest that a substantial fraction of satellite galaxies are causally linked in their formation and evolution.
Molecular insights into the differences in anti-inflammatory activities of green tea catechins on IL-1β signaling in rheumatoid arthritis synovial fibroblasts.

Science.gov (United States)

Fechtner, Sabrina; Singh, Anil; Chourasia, Mukesh; Ahmed, Salahuddin

2017-08-15

In this study, we found that catechins found in green tea (EGCG, EGC, and EC) differentially interfere with the IL-1β signaling pathway which regulates the expression of pro-inflammatory mediators (IL-6 and IL-8) and Cox-2 in primary human rheumatoid arthritis synovial fibroblasts (RASFs). EGCG and EGC inhibited IL-6, IL-8, and MMP-2 production and selectively inhibited Cox-2 expression. EC did not exhibit any inhibitory effects. When we looked at the expression of key signaling proteins in the IL-1β signaling pathway, we found all the tested catechins could inhibit TAK-1 activity. Therefore, the consumption of green tea offers an overall anti-inflammatory effect. Molecular docking analysis confirms that EGCG, EGC, and EC all occupy the active site of the TAK1 kinase domain. However, EGCG occupies the majority of the TAK1 active site. In addition to TAK1 inhibition, EGCG can also inhibit P38 and nuclear NF-κB expression whereas EC and EGC were not effective inhibitors. Our findings suggest one of the main health benefits associated with the consumption of green tea are due to the activity of EGCG and EGC which are both present at higher amounts. Although EGCG is the most effective catechin at inhibiting downstream inflammatory signaling, its effectiveness could be hindered by the presence of EC. Therefore, varying EC content in green tea may reduce the anti-inflammatory effects of other potential catechins in green tea. Copyright © 2017. Published by Elsevier Inc.
Clinical relevance of quantified fundus autofluorescence in diabetic macular oedema.

Science.gov (United States)

Yoshitake, S; Murakami, T; Uji, A; Unoki, N; Dodo, Y; Horii, T; Yoshimura, N

2015-05-01

To quantify the signal intensity of fundus autofluorescence (FAF) and evaluate its association with visual function and optical coherence tomography (OCT) findings in diabetic macular oedema (DMO). We reviewed 103 eyes of 78 patients with DMO and 30 eyes of 22 patients without DMO. FAF images were acquired using Heidelberg Retina Angiograph 2, and the signal levels of FAF in the individual subfields of the Early Treatment Diabetic Retinopathy Study grid were measured. We evaluated the association between quantified FAF and the logMAR VA and OCT findings. One hundred and three eyes with DMO had lower FAF signal intensity levels in the parafoveal subfields compared with 30 eyes without DMO. The autofluorescence intensity in the parafoveal subfields was associated negatively with logMAR VA and the retinal thickness in the corresponding subfields. The autofluorescence levels in the parafoveal subfield, except the nasal subfield, were lower in eyes with autofluorescent cystoid spaces in the corresponding subfield than in those without autofluorescent cystoid spaces. The autofluorescence level in the central subfield was related to foveal cystoid spaces but not logMAR VA or retinal thickness in the corresponding area. Quantified FAF in the parafovea has diagnostic significance and is clinically relevant in DMO.
Correlation between CD105 expression and postoperative recurrence and metastasis of hepatocellular carcinoma

Directory of Open Access Journals (Sweden)

Wang Wei

2006-05-01

correlation between microscopic venous invasion and CD105-MVD, but not CD34-MVD, was also statistically significant (r = 0.254, P = 0.018. Univariate analysis showed that CD105-MVD was significantly correlated with the 2-year overall survival rate (P = 0.014; CD34-MVD was not (P = 0.601. Multivariate analysis confirmed that CD105-MVD was an independent prognostic factor and that CD34-MVD was not. Conclusion The anti-CD105 mAb is an ideal instrument to quantify new microvessels in HCC as compared with anti-CD34 mAb. CD105-MVD as compared with CD34-MVD is relevant a significant and independent prognostic indicator for recurrence and metastasis in HCC patients.
Observation of B0-anti B0 mixing

International Nuclear Information System (INIS)

Albrecht, H.; Andam, A.A.; Binder, U.; Boeckmann, P.; Glaeser, R.; Harder, G.; Nippe, A.; Schaefer, M.; Schmidt-Parzefall, W.; Schroeder, H.; Schulz, H.D.; Wurth, R.; Yagil, A.; Donker, J.P.; Drescher, A.; Kamp, D.; Kolanoski, H.; Matthiesen, U.; Scheck, H.; Spaan, B.; Spengler, J.; Wegener, D.; Frisken, W.R.; Gilkinson, D.J.; Gingrich, D.M.; Kim, P.C.H.; Kutschke, R.; McKenna, J.A.; Orr, R.S.; Padley, P.; Parsons, J.A.; Prentice, J.D.; Seywerd, H.C.J.; Swain, J.D.; Yoon, T.S.; MacFarlane, D.B.; McLean, K.W.; Nilsson, A.W.; Patel, P.M.; Tsipolitis, G.; Ammar, R.; Coppage, D.; Davis, R.; Kanekal, S.; Kwak, N.; Bostjancic, B.; Kernel, G.; Plesko, M.; Childers, R.; Darden, C.W.; Oku, Y.; Gennow, H.

1987-01-01

Using the ARGUS detector at the DORIS II storage ring we have searched in three different ways for B 0 -anti B 0 mixing in Υ (4S) decays. One explicitly mixed event, a decay Υ (4S) → B 0 B 0 , has been completely reconstructed. Furthermore, we observe a 4.0 standard deviation signal of 24.8 events with like-sign lepton pairs and a 3.0 standard deviation signal of 4.1 events containing one reconstructed B 0 (anti B 0 ) and an additional fast l + (l - ). This leads to the conclusion that B 0 -anti B 0 mixing is substantial. For the mixing parameter we obtain r = 0.21±0.08. (orig.)

Rapid phospho-turnover by receptor tyrosine kinases impacts downstream signaling and drug binding.

Science.gov (United States)

Kleiman, Laura B; Maiwald, Thomas; Conzelmann, Holger; Lauffenburger, Douglas A; Sorger, Peter K

2011-09-02

Epidermal growth factor receptors (ErbB1-4) are oncogenic receptor tyrosine kinases (RTKs) that regulate diverse cellular processes. In this study, we combine measurement and mathematical modeling to quantify phospho-turnover at ErbB receptors in human cells and to determine the consequences for signaling and drug binding. We find that phosphotyrosine residues on ErbB1 have half-lives of a few seconds and therefore turn over 100-1000 times in the course of a typical immediate-early response to ligand. Rapid phospho-turnover is also observed for EGF-activated ErbB2 and ErbB3, unrelated RTKs, and multiple intracellular adaptor proteins and signaling kinases. Thus, the complexes formed on the cytoplasmic tail of active receptors and the downstream signaling kinases they control are highly dynamic and antagonized by potent phosphatases. We develop a kinetic scheme for binding of anti-ErbB1 drugs to receptors and show that rapid phospho-turnover significantly impacts their mechanisms of action. Copyright © 2011 Elsevier Inc. All rights reserved.
Stimfit: quantifying electrophysiological data with Python

Directory of Open Access Journals (Sweden)

Segundo Jose Guzman

2014-02-01

Full Text Available Intracellular electrophysiological recordings provide crucial insights into elementary neuronal signals such as action potentials and synaptic currents. Analyzing and interpreting these signals is essential for a quantitative understanding of neuronal information processing, and requires both fast data visualization and ready access to complex analysis routines. To achieve this goal, we have developed Stimfit, a free software package for cellular neurophysiology with a Python scripting interface and a built-in Python shell. The program supports most standard file formats for cellular neurophysiology and other biomedical signals through the Biosig library. To quantify and interpret the activity of single neurons and communication between neurons, the program includes algorithms to characterize the kinetics of presynaptic action potentials and postsynaptic currents, estimate latencies between pre- and postsynaptic events, and detect spontaneously occurring events. We validate and benchmark these algorithms, give estimation errors, and provide sample use cases, showing that Stimfit represents an efficient, accessible and extensible way to accurately analyze and interpret neuronal signals.
Signals, systems, transforms, and digital signal processing with Matlab

CERN Document Server

Corinthios, Michael

2009-01-01

Continuous-Time and Discrete-Time Signals and SystemsIntroductionContinuous-Time SignalsPeriodic FunctionsUnit Step FunctionGraphical Representation of FunctionsEven and Odd Parts of a FunctionDirac-Delta ImpulseBasic Properties of the Dirac-Delta ImpulseOther Important Properties of the ImpulseContinuous-Time SystemsCausality, StabilityExamples of Electrical Continuous-Time SystemsMechanical SystemsTransfer Function and Frequency ResponseConvolution and CorrelationA Right-Sided and a Left-Sided FunctionConvolution with an Impulse and Its DerivativesAdditional Convolution PropertiesCorrelation FunctionProperties of the Correlation FunctionGraphical InterpretationCorrelation of Periodic FunctionsAverage, Energy and Power of Continuous-Time SignalsDiscrete-Time SignalsPeriodicityDifference EquationsEven/Odd DecompositionAverage Value, Energy and Power SequencesCausality, StabilityProblemsAnswers to Selected ProblemsFourier Series ExpansionTrigonometric Fourier SeriesExponential Fourier SeriesExponential versus ...
Baicalin Inhibits Lipopolysaccharide-Induced Inflammation Through Signaling NF-κB Pathway in HBE16 Airway Epithelial Cells.

Science.gov (United States)

Dong, Shou-jin; Zhong, Yun-qing; Lu, Wen-ting; Li, Guan-hong; Jiang, Hong-li; Mao, Bing

2015-08-01

Baicalin, a flavonoid monomer derived from Scutellaria baicalensis called Huangqin in mandarin, is the main active ingredient contributing to S. baicalensis' efficacy. It is known in China that baicalin has potential therapeutic effects on inflammatory diseases. However, its anti-inflammatory mechanism has still not been fully interpreted. We aim to investigate the anti-inflammatory effect of baicalin on lipopolysaccharide (LPS)-induced inflammation in HBE16 airway epithelial cells and also to explore the underlying signaling mechanisms. The anti-inflammatory action of baicalin was evaluated in human airway epithelial cells HBE16 treated with LPS. Airway epithelial cells HBE16 were pretreated with a range of concentrations of baicalin for 30 min and then stimulated with 10 μg/ml LPS. The secretions of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) in cell culture supernatants were quantified by enzyme-linked immunosorbent assay (ELISA). The messenger RNA (mRNA) expressions of IL-6, IL-8, and TNF-α were tested by quantitative real-time polymerase chain reaction (real-time RT-PCR). Furthermore, Western blotting was used to determine whether the signaling pathway NF-κB was involved in the anti-inflammatory action of baicalin. The inflammatory cell model was successfully built with 10 μg/ml LPS for 24 h in our in vitro experiments. Both the secretions and the mRNA expressions of IL-6, IL-8, and TNF-α were significantly inhibited by baicalin. Moreover, the expression levels of phospho-IKKα/β and phospho-NF-κB p65 were downregulated, and the phospho-IκB-α level was upregulated by baicalin. These findings suggest that the anti-inflammatory properties of baicalin may be resulted from the inhibition of IL-6, IL-8, and TNF-α expression via preventing signaling NF-κB pathway in HBE16 airway epithelial cells. In addition, this study provides evidence to understand the therapeutic effects of baicalin on inflammatory diseases in
Correlated inter-regional variations in low frequency local field potentials and resting state BOLD signals within S1 cortex of monkeys.

Science.gov (United States)

Wilson, George H; Yang, Pai-Feng; Gore, John C; Chen, Li Min

2016-08-01

The hypothesis that specific frequency components of the spontaneous local field potentials (LFPs) underlie low frequency fluctuations of resting state fMRI (rsfMRI) signals was tested. The previous analyses of rsfMRI signals revealed differential inter-regional correlations among areas 3a, 3b, and 1 of primary somatosensory cortex (S1) in anesthetized monkeys (Wang et al. [2013]: Neuron 78:1116-1126). Here LFP band(s) which correlated between S1 regions, and how these inter-regional correlation differences covaried with rsfMRI signals were examined. LFP signals were filtered into seven bands (delta, theta, alpha, beta, gamma low, gamma high, and gamma very high), and then a Hilbert transformation was applied to obtain measures of instantaneous amplitudes and temporal lags between regions of interest (ROI) digit-digit pairs (areas 3b-area 1, area 3a-area 1, area 3a-area 3b) and digit-face pairs (area 3b-face, area 1-face, and area 3a-face). It was found that variations in the inter-regional correlation strengths between digit-digit and digit-face pairs in the delta (1-4 Hz), alpha (9-14 Hz), beta (15-30 Hz), and gamma (31-50 Hz) bands parallel those of rsfMRI signals to varying degrees. Temporal lags between digit-digit area pairs varied across LFP bands, with area 3a mostly leading areas 1/2 and 3b. In summary, the data demonstrates that the low and middle frequency range (1-50 Hz) of spontaneous LFP signals similarly covary with the low frequency fluctuations of rsfMRI signals within local circuits of S1, supporting a neuronal electrophysiological basis of rsfMRI signals. Inter-areal LFP temporal lag differences provided novel insights into the directionality of information flow among S1 areas at rest. Hum Brain Mapp 37:2755-2766, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Laryngeal carcinoma after radiation therapy: correlation of abnormal MR imaging signal patterns in laryngeal cartilage with the risk of recurrence

NARCIS (Netherlands)

Castelijns, J. A.; van den Brekel, M. W.; Tobi, H.; Smit, E. M.; Golding, R. P.; van Schaik, C.; Snow, G. B.

1996-01-01

To correlate abnormal magnetic resonance (MR) imaging signal patterns in cartilage with the effectiveness of radiation treatment. Eighty previously untreated patients underwent MR imaging and radiation therapy with a curative intent. Cartilage was considered to have an abnormal signal pattern if it
Quadratic Frequency Modulation Signals Parameter Estimation Based on Two-Dimensional Product Modified Parameterized Chirp Rate-Quadratic Chirp Rate Distribution.

Science.gov (United States)

Qu, Zhiyu; Qu, Fuxin; Hou, Changbo; Jing, Fulong

2018-05-19

In an inverse synthetic aperture radar (ISAR) imaging system for targets with complex motion, the azimuth echo signals of the target are always modeled as multicomponent quadratic frequency modulation (QFM) signals. The chirp rate (CR) and quadratic chirp rate (QCR) estimation of QFM signals is very important to solve the ISAR image defocus problem. For multicomponent QFM (multi-QFM) signals, the conventional QR and QCR estimation algorithms suffer from the cross-term and poor anti-noise ability. This paper proposes a novel estimation algorithm called a two-dimensional product modified parameterized chirp rate-quadratic chirp rate distribution (2D-PMPCRD) for QFM signals parameter estimation. The 2D-PMPCRD employs a multi-scale parametric symmetric self-correlation function and modified nonuniform fast Fourier transform-Fast Fourier transform to transform the signals into the chirp rate-quadratic chirp rate (CR-QCR) domains. It can greatly suppress the cross-terms while strengthening the auto-terms by multiplying different CR-QCR domains with different scale factors. Compared with high order ambiguity function-integrated cubic phase function and modified Lv's distribution, the simulation results verify that the 2D-PMPCRD acquires higher anti-noise performance and obtains better cross-terms suppression performance for multi-QFM signals with reasonable computation cost.
Aging-related changes in the default mode network and its anti-correlated networks: a resting-state fMRI study.

Science.gov (United States)

Wu, Jing-Tao; Wu, Hui-Zhen; Yan, Chao-Gan; Chen, Wen-Xin; Zhang, Hong-Ying; He, Yong; Yang, Hai-Shan

2011-10-17

Intrinsic brain activity in a resting state incorporates components of the task negative network called default mode network (DMN) and task-positive networks called attentional networks. In the present study, the reciprocal neuronal networks in the elder group were compared with the young group to investigate the differences of the intrinsic brain activity using a method of temporal correlation analysis based on seed regions of posterior cingulate cortex (PCC) and ventromedial prefrontal cortex (vmPFC). We found significant decreased positive correlations and negative correlations with the seeds of PCC and vmPFC in the old group. The decreased coactivations in the DMN network components and their negative networks in the old group may reflect age-related alterations in various brain functions such as attention, motor control and inhibition modulation in cognitive processing. These alterations in the resting state anti-correlative networks could provide neuronal substrates for the aging brain. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Can I solve my structure by SAD phasing? Planning an experiment, scaling data and evaluating the useful anomalous correlation and anomalous signal.

Science.gov (United States)

Terwilliger, Thomas C; Bunkóczi, Gábor; Hung, Li Wei; Zwart, Peter H; Smith, Janet L; Akey, David L; Adams, Paul D

2016-03-01

A key challenge in the SAD phasing method is solving a structure when the anomalous signal-to-noise ratio is low. Here, algorithms and tools for evaluating and optimizing the useful anomalous correlation and the anomalous signal in a SAD experiment are described. A simple theoretical framework [Terwilliger et al. (2016), Acta Cryst. D72, 346-358] is used to develop methods for planning a SAD experiment, scaling SAD data sets and estimating the useful anomalous correlation and anomalous signal in a SAD data set. The phenix.plan_sad_experiment tool uses a database of solved and unsolved SAD data sets and the expected characteristics of a SAD data set to estimate the probability that the anomalous substructure will be found in the SAD experiment and the expected map quality that would be obtained if the substructure were found. The phenix.scale_and_merge tool scales unmerged SAD data from one or more crystals using local scaling and optimizes the anomalous signal by identifying the systematic differences among data sets, and the phenix.anomalous_signal tool estimates the useful anomalous correlation and anomalous signal after collecting SAD data and estimates the probability that the data set can be solved and the likely figure of merit of phasing.
Widespread anti-sense transcription in apple is correlated with siRNA production and indicates a large potential for transcriptional and/or post-transcriptional control.

Science.gov (United States)

Celton, Jean-Marc; Gaillard, Sylvain; Bruneau, Maryline; Pelletier, Sandra; Aubourg, Sébastien; Martin-Magniette, Marie-Laure; Navarro, Lionel; Laurens, François; Renou, Jean-Pierre

2014-07-01

Characterizing the transcriptome of eukaryotic organisms is essential for studying gene regulation and its impact on phenotype. The realization that anti-sense (AS) and noncoding RNA transcription is pervasive in many genomes has emphasized our limited understanding of gene transcription and post-transcriptional regulation. Numerous mechanisms including convergent transcription, anti-correlated expression of sense and AS transcripts, and RNAi remain ill-defined. Here, we have combined microarray analysis and high-throughput sequencing of small RNAs (sRNAs) to unravel the complexity of transcriptional and potential post-transcriptional regulation in eight organs of apple (Malus × domestica). The percentage of AS transcript expression is higher than that identified in annual plants such as rice and Arabidopsis thaliana. Furthermore, we show that a majority of AS transcripts are transcribed beyond 3'UTR regions, and may cover a significant portion of the predicted sense transcripts. Finally we demonstrate at a genome-wide scale that anti-sense transcript expression is correlated with the presence of both short (21-23 nt) and long (> 30 nt) siRNAs, and that the sRNA coverage depth varies with the level of AS transcript expression. Our study provides a new insight on the functional role of anti-sense transcripts at the genome-wide level, and a new basis for the understanding of sRNA biogenesis in plants. © 2014 INRA. New Phytologist © 2014 New Phytologist Trust.
Full-field wrist pulse signal acquisition and analysis by 3D Digital Image Correlation

Science.gov (United States)

Xue, Yuan; Su, Yong; Zhang, Chi; Xu, Xiaohai; Gao, Zeren; Wu, Shangquan; Zhang, Qingchuan; Wu, Xiaoping

2017-11-01

Pulse diagnosis is an essential part in four basic diagnostic methods (inspection, listening, inquiring and palpation) in traditional Chinese medicine, which depends on longtime training and rich experience, so computerized pulse acquisition has been proposed and studied to ensure the objectivity. To imitate the process that doctors using three fingertips with different pressures to feel fluctuations in certain areas containing three acupoints, we established a five dimensional pulse signal acquisition system adopting a non-contacting optical metrology method, 3D digital image correlation, to record the full-field displacements of skin fluctuations under different pressures. The system realizes real-time full-field vibration mode observation with 10 FPS. The maximum sample frequency is 472 Hz for detailed post-processing. After acquisition, the signals are analyzed according to the amplitude, pressure, and pulse wave velocity. The proposed system provides a novel optical approach for digitalizing pulse diagnosis and massive pulse signal data acquisition for various types of patients.
Adaptive filtration of speech signals in the presence of correlated noise with random variation of probabilistic characteristics

OpenAIRE

M. O. Partala; S. Ya. Zhuk

2007-01-01

On the base of mixed Markoff process in discrete time optimal and quasioptimal algorithms is designed for adaptive filtration of speech signals in the presence of correlated noise with random variation of probabilistic characteristics.
Correlative intravital imaging of cGMP signals and vasodilation in mice

Directory of Open Access Journals (Sweden)

Martin eThunemann

2014-10-01

Full Text Available Cyclic guanosine monophosphate (cGMP is an important signaling molecule and drug target in the cardiovascular system. It is well known that stimulation of the vascular nitric oxide (NO-cGMP pathway results in vasodilation. However, the spatiotemporal dynamics of cGMP signals themselves and the cGMP concentrations within specific cardiovascular cell types in health, disease, and during pharmacotherapy with cGMP-elevating drugs are largely unknown. To facilitate the analysis of cGMP signaling in vivo, we have generated transgenic mice that express fluorescence resonance energy transfer (FRET-based cGMP sensor proteins. Here, we describe two models of intravital FRET/cGMP imaging in the vasculature of cGMP sensor mice: (1 epifluorescence-based ratio imaging in resistance-type vessels of the cremaster muscle and (2 ratio imaging by multiphoton microscopy within the walls of subcutaneous blood vessels accessed through a dorsal skinfold chamber. Both methods allow simultaneous monitoring of NO-induced cGMP transients and vasodilation in living mice. Detailed protocols of all steps necessary to perform and evaluate intravital imaging experiments of the vasculature of anesthetized mice including surgery, imaging, and data evaluation are provided. An image segmentation approach is described to estimate FRET/cGMP changes within moving structures such as the vessel wall during vasodilation. The methods presented herein should be useful to visualize cGMP or other biochemical signals that are detectable with FRET-based biosensors, such as cyclic adenosine monophosphate or Ca2+, and to correlate them with respective vascular responses. With further refinement and combination of transgenic mouse models and intravital imaging technologies, we envision an exciting future, in which we are able to ‘watch’ biochemistry, (patho physiology, and pharmacotherapy in the context of a living mammalian organism.
Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: Implications for resilience

Science.gov (United States)

Gothe, Emma; Sandin, Leonard; Allen, Craig R.; Angeler, David G.

2014-01-01

The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.
Application of lag-k autocorrelation coefficient and the TGA signals approach to detecting and quantifying adulterations of extra virgin olive oil with inferior edible oils

Energy Technology Data Exchange (ETDEWEB)

Torrecilla, Jose S., E-mail: jstorre@quim.ucm.es [Department of Chemical Engineering, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid (Spain); Garcia, Julian; Garcia, Silvia; Rodriguez, Francisco [Department of Chemical Engineering, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid (Spain)

2011-03-04

The combination of lag-k autocorrelation coefficients (LCCs) and thermogravimetric analyzer (TGA) equipment is defined here as a tool to detect and quantify adulterations of extra virgin olive oil (EVOO) with refined olive (ROO), refined olive pomace (ROPO), sunflower (SO) or corn (CO) oils, when the adulterating agents concentration are less than 14%. The LCC is calculated from TGA scans of adulterated EVOO samples. Then, the standardized skewness of this coefficient has been applied to classify pure and adulterated samples of EVOO. In addition, this chaotic parameter has also been used to quantify the concentration of adulterant agents, by using successful linear correlation of LCCs and ROO, ROPO, SO or CO in 462 EVOO adulterated samples. In the case of detection, more than 82% of adulterated samples have been correctly classified. In the case of quantification of adulterant concentration, by an external validation process, the LCC/TGA approach estimates the adulterant agents concentration with a mean correlation coefficient (estimated versus real adulterant agent concentration) greater than 0.90 and a mean square error less than 4.9%.
Application of lag-k autocorrelation coefficient and the TGA signals approach to detecting and quantifying adulterations of extra virgin olive oil with inferior edible oils

International Nuclear Information System (INIS)

Torrecilla, Jose S.; Garcia, Julian; Garcia, Silvia; Rodriguez, Francisco

2011-01-01

The combination of lag-k autocorrelation coefficients (LCCs) and thermogravimetric analyzer (TGA) equipment is defined here as a tool to detect and quantify adulterations of extra virgin olive oil (EVOO) with refined olive (ROO), refined olive pomace (ROPO), sunflower (SO) or corn (CO) oils, when the adulterating agents concentration are less than 14%. The LCC is calculated from TGA scans of adulterated EVOO samples. Then, the standardized skewness of this coefficient has been applied to classify pure and adulterated samples of EVOO. In addition, this chaotic parameter has also been used to quantify the concentration of adulterant agents, by using successful linear correlation of LCCs and ROO, ROPO, SO or CO in 462 EVOO adulterated samples. In the case of detection, more than 82% of adulterated samples have been correctly classified. In the case of quantification of adulterant concentration, by an external validation process, the LCC/TGA approach estimates the adulterant agents concentration with a mean correlation coefficient (estimated versus real adulterant agent concentration) greater than 0.90 and a mean square error less than 4.9%.
Recent ice cap snowmelt in Russian High Arctic and anti-correlation with late summer sea ice extent

International Nuclear Information System (INIS)

Zhao, Meng; Ramage, Joan; Semmens, Kathryn; Obleitner, Friedrich

2014-01-01

Glacier surface melt dynamics throughout Novaya Zemlya (NovZ) and Severnaya Zemlya (SevZ) serve as a good indicator of ice mass ablation and regional climate change in the Russian High Arctic. Here we report trends of surface melt onset date (MOD) and total melt days (TMD) by combining multiple resolution-enhanced active and passive microwave satellite datasets and analyze the TMD correlations with local temperature and regional sea ice extent. The glacier surface snowpack on SevZ melted significantly earlier (−7.3 days/decade) from 1992 to 2012 and significantly longer (7.7 days/decade) from 1995 to 2011. NovZ experienced large interannual variability in MOD, but its annual mean TMD increased. The snowpack melt on NovZ is more sensitive to temperature fluctuations than SevZ in recent decades. After ruling out the regional temperature influence using partial correlation analysis, the TMD on both archipelagoes is statistically anti-correlated with regional late summer sea ice extent, linking land ice snowmelt dynamics to regional sea ice extent variations. (letter)
Temporal separation of the density fluctuation signal measured by light scattering

International Nuclear Information System (INIS)

Antar, G.; Devynk, P.; Laviron, C.; Garbet, X.; Sabot, R.; Fenzi, C.; Hennequin, P.; Truc, A.; Quemeneur, A.; Honore, C.; Gervais, F.

1999-02-01

On Tore Supra, the frequency spectra of the turbulent fluctuations often have two peaks centered on some positive and negative values. These two peaks correspond to a poloidal motion of electron turbulence in opposite directions. In this paper, a criterion is elaborated allowing us to distinguish, in time, density fluctuations convected in the parallel from those in the anti-parallel direction with respect to the analysing wavevector. Two signals are thus extracted out of one. The validity of our model is experimentally checked up by comparing the auto-correlation coefficients and the frequency spectra computed for the whole and the separated signals. Consequently, the frequency spectrum is studied in detail as a function of the analysing wavenumber leading to an accurate determination of some plasma properties. (authors)
Correlation Functions and Power Spectra

DEFF Research Database (Denmark)

Larsen, Jan

2006-01-01

The present lecture note is a supplement to the textbook Digital Signal Processing by J. Proakis and D.G. Manolakis used in the IMM/DTU course 02451 Digital Signal Processing and provides an extended discussion of correlation functions and power spectra. The definitions of correlation functions...... and spectra for discrete-time and continuous-time (analog) signals are pretty similar. Consequently, we confine the discussion mainly to real discrete-time signals. The Appendix contains detailed definitions and properties of correlation functions and spectra for analog as well as discrete-time signals....... It is possible to define correlation functions and associated spectra for aperiodic, periodic and random signals although the interpretation is different. Moreover, we will discuss correlation functions when mixing these basic signal types. In addition, the note include several examples for the purpose...
Effect of downed woody debris on small mammal anti-predator behavior

Science.gov (United States)

Travis M. Hinkelman; John L. Orrock; Susan C Loeb

2011-01-01

Anti-Predator behavior can affect prey growth, reproduction, survival, and generate emergent effects in food webs. Small mammals often lower the cost of predation by altering their behavior in response to shrubs, but the importance of other microhabitat features, such as downed woody debris, for anti-predator behavior is unknown. We used giving-up densities to quantify...

Anti-inflammatory and anti-cancer activity of mulberry (Morus alba L.) root bark

Science.gov (United States)

2014-01-01

Background Root bark of mulberry (Morus alba L.) has been used in herbal medicine as anti-phlogistic, liver protective, kidney protective, hypotensive, diuretic, anti-cough and analgesic agent. However, the anti-cancer activity and the potential anti-cancer mechanisms of mulberry root bark have not been elucidated. We performed in vitro study to investigate whether mulberry root bark extract (MRBE) shows anti-inflammatory and anti-cancer activity. Methods In anti-inflammatory activity, NO was measured using the griess method. iNOS and proteins regulating NF-κB and ERK1/2 signaling were analyzed by Western blot. In anti-cancer activity, cell growth was measured by MTT assay. Cleaved PARP, ATF3 and cyclin D1 were analyzed by Western blot. Results In anti-inflammatory effect, MRBE blocked NO production via suppressing iNOS over-expression in LPS-stimulated RAW264.7 cells. In addition, MRBE inhibited NF-κB activation through p65 nuclear translocation via blocking IκB-α degradation and ERK1/2 activation via its hyper-phosphorylation. In anti-cancer activity, MRBE deos-dependently induced cell growth arrest and apoptosis in human colorectal cancer cells, SW480. MRBE treatment to SW480 cells activated ATF3 expression and down-regulated cyclin D1 level. We also observed that MRBE-induced ATF3 expression was dependent on ROS and GSK3β. Moreover, MRBE-induced cyclin D1 down-regulation was mediated from cyclin D1 proteasomal degradation, which was dependent on ROS. Conclusions These findings suggest that mulberry root bark exerts anti-inflammatory and anti-cancer activity. PMID:24962785
The level of CD147 expression correlates with cyclophilin-induced signalling and chemotaxis

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Constant Stephanie

2011-10-01

Full Text Available Abstract Background Previous studies identified CD147 as the chemotactic receptor on inflammatory leukocytes for extracellular cyclophilins (eCyp. However, CD147 is not known to associate with signal transducing molecules, so other transmembrane proteins, such as proteoglycans, integrins, and CD98, were suggested as receptor or co-receptor for eCyp. CD147 is ubiquitously expressed on many cell types, but relationship between the level of CD147 expression and cellular responses to eCyp has never been analyzed. Given the role of eCyp in pathogenesis of many diseases, it is important to know whether cellular responses to eCyp are regulated at the level of CD147 expression. Results Here, we manipulated CD147 expression levels on HeLa cells using RNAi and investigated the signalling and chemotactic responses to eCypA. Both Erk activation and chemotaxis correlated with the level of CD147 expression, with cells exhibiting low level expression being practically unresponsive to eCypA. Conclusions Our results provide the first demonstration of a chemotactic response of HeLa cells to eCypA, establish a correlation between the level of CD147 expression and the magnitude of cellular responses to eCypA, and indicate that CD147 may be a limiting factor in the receptor complex determining cyclophilin-induced Erk activation and cell migration.
Effective capacity of multiple antenna channels: Correlation and keyhole

KAUST Repository

Zhong, Caijun

2012-01-01

In this study, the authors derive the effective capacity limits for multiple antenna channels which quantify the maximum achievable rate with consideration of link-layer delay-bound violation probability. Both correlated multiple-input single-output and multiple-input multiple-output keyhole channels are studied. Based on the closed-form exact expressions for the effective capacity of both channels, the authors look into the asymptotic high and low signal-to-noise ratio regimes, and derive simple expressions to gain more insights. The impact of spatial correlation on effective capacity is also characterised with the aid of a majorisation theory result. It is revealed that antenna correlation reduces the effective capacity of the channels and a stringent quality-of-service requirement causes a severe reduction in the effective capacity but can be alleviated by increasing the number of antennas. © 2012 The Institution of Engineering and Technology.
Quantifying linguistic coordination

DEFF Research Database (Denmark)

Fusaroli, Riccardo; Tylén, Kristian

task (Bahrami et al 2010, Fusaroli et al. 2012) we extend to linguistic coordination dynamical measures of recurrence employed in the analysis of sensorimotor coordination (such as heart-rate (Konvalinka et al 2011), postural sway (Shockley 2005) and eye-movements (Dale, Richardson and Kirkham 2012......). We employ nominal recurrence analysis (Orsucci et al 2005, Dale et al 2011) on the decision-making conversations between the participants. We report strong correlations between various indexes of recurrence and collective performance. We argue this method allows us to quantify the qualities...
Additive Effects of Quorum Sensing Anti-Activators on Pseudomonas aeruginosa Virulence Traits and Transcriptome

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Kyle L. Asfahl

2018-01-01

Full Text Available In the opportunistic pathogen Pseudomonas aeruginosa, quorum sensing (QS via acyl-homoserine lactone (AHL signals coordinates virulence gene expression. AHL signals must reach a critical threshold before enough is bound by cognate regulators LasR and RhlR to drive transcription of target genes. In addition, three anti-activator proteins, QteE, QscR, and QslA, sequester QS regulators to increase the threshold for induction and delay expression of QS target genes. It remains unclear how multiple anti-activators work together to achieve the quorum threshold. Here, we employed a combination of mutational, kinetic, phenotypic, and transcriptomic analysis to examine regulatory effects and interactions of the three distinct anti-activators. We observed combinatorial, additive effects on QS gene expression. As measured by reporter gene fusion, individual deletion of each anti-activator gene increased lasB expression and QS-controlled virulence factor production. Deletion of qslA in combination with the deletion of any other anti-activator gene resulted in the greatest increase and earliest activation of lasB gene expression. Western analysis revealed that relative increases in soluble LasR in anti-activator mutants correlate with increased lasB expression and QS-controlled virulence factor production. RNA-seq of the previously uncharacterized QslA and QteE regulons revealed overlapping, yet distinct groups of differentially expressed genes. Simultaneous inactivation of qteE and qslA had the largest effect on gene expression with 999 genes induced and 798 genes repressed in the double mutant vs. wild-type. We found that LasR and RhlR-activated QS genes formed a subset of the genes induced in the qteE, qslA, and double mutant. The activation of almost all of these QS genes was advanced from stationary phase to log phase in the qteE qslA double mutant. Taken together, our results identify additive effects of anti-activation on QS gene expression, likely
[CORRELATION OF ANTI-MULLERIAN HORMONE WITH HORMONAL AND OVARIAN MORPHOLOGICAL CHARACTERISTICS IN PATIENTS WITH POLYCYSTIC OVARY SYNDROME WITH AND WITHOUT INSULIN RESISTANCE].

Science.gov (United States)

Asanidze, E; Khristesashvili, J; Pkhaladze, L; Barbakadze, L

2018-02-01

PCOS has a leading place in women's infertility. Based on the data of recent researches, Anti-Mullerian hormone (AMH) has been considered as one of the diagnostic criteria for PCOS. The aim of study was to determine the correlation of Anti-Mullerian hormone with hormonal and ovarian morphological characteristics in patients with PCOS, with and without insulin resistance. 110 women with diagnosis of PCOS were involved in the study. Patients were divided into two groups: PCOS patients with insulin resistance (60 women) and PCOS patients without insulin resistance (50 women). All patients underwent hormonal investigation (AMH, FSH, LH, T, FT, HOMA- IR, FAI and SHBG). The volume of ovaries and the number of antral follicles (AFC) were determined by ultrasound imaging. Сorrelation between AMH and the ovarian hormonal and morphological characteristics has been shown. In particular, a significant positive correlation between AMH and the volume of the ovaries in both groups was demonstrated. In the group of patients with PCOS and insulin resistance a positive correlation between AMH and the volum of ovary, AFC was shown, as well as a negative correlation between AMH and SHBG. In the same group a tendency of the positive correlation between AMH and TT, HOMA-IR and IRI was seen. In the group of patients with PCOS without insulin resistence a positive correlation between AMH and the volum of ovary was observed, as well as the tendency of positive correlation between AMH and AFC, TT, HOMA-IR, IRI. Additionally, a negative correlation between AMH and SHBG was seen in the later patient group. Increased levels of AMH in all PCOS patients in our study, in comparison with the accepted norm, indicates on possibility of using this data in the diagnosis of PCOS. AMH levels in PCOS patients with and without insulin resistance do not differ significantly. The correlation between AMH and the morphological characteristics of ovaries has been established.
Anti-Angiogenics: Current Situation and Future Perspectives.

Science.gov (United States)

Zirlik, Katja; Duyster, Justus

2018-01-01

Angiogenesis, the process leading to the formation of new blood vessels, is one of the hallmarks of cancer. Extensive studies established that i) vascular endothelial growth factor (VEGF) is a key driver of sprouting angiogenesis, ii) VEGF is overexpressed in most solid cancers, and iii) inhibition of VEGF can suppress tumor growth in animal models. This has led to the development of pharmacological agents for anti-angiogenesis to disrupt the vascular supply and starve the tumor of nutrients and oxygen, primarily through the blockade of VEGF/VEGF receptor signaling. This effort has resulted in 11 anti-VEGF drugs approved for certain advanced cancers, either alone or in combination with chemotherapy and other targeted therapies. However, inhibition of VEGF signaling is not effective in all cancers, and anti-angiogenics have often only limited impact on overall survival of cancer patients. This review focuses on the current status of FDA-approved anti-angiogenic antibodies and tyrosine kinase inhibitors and summarizes the progress and future directions of VEGF-targeted therapy. © 2018 S. Karger GmbH, Freiburg.
Anti-angiogenesis effect of the novel anti-inflammatory and pro-resolving lipid mediators.

Science.gov (United States)

Jin, Yiping; Arita, Makoto; Zhang, Qiang; Saban, Daniel R; Chauhan, Sunil K; Chiang, Nan; Serhan, Charles N; Dana, Reza

2009-10-01

Resolvins and lipoxins are lipid mediators generated from essential polyunsaturated fatty acids that are the first dual anti-inflammatory and pro-resolving signals identified in the resolution phase of inflammation. Here the authors investigated the potential of aspirin-triggered lipoxin (LX) A4 analog (ATLa), resolving (Rv) D1, and RvE1, in regulating angiogenesis in a murine model. ATLa and RvE1 receptor expression was tested in different corneal cell populations by RT-PCR. Corneal neovascularization (CNV) was induced by suture or micropellet (IL-1 beta, VEGF-A) placement. Mice were then treated with ATLa, RvD1, RvE1, or vehicle, subconjunctivally at 48-hour intervals. Infiltration of neutrophils and macrophages was quantified after immunofluorescence staining. The mRNA expression levels of inflammatory cytokines, VEGFs, and VEGFRs were analyzed by real-time PCR. CNV was evaluated intravitally and morphometrically. The receptors for LXA4, ALX/Fpr-rs-2 and for RvE1, ChemR23 were each expressed by epithelium, stromal keratocytes, and infiltrated CD11b(+) cells in corneas. Compared to the vehicle-treated eye, ATLa-, RvD1-, and RvE1-treated eyes had reduced numbers of infiltrating neutrophils and macrophages and reduced mRNA expression levels of TNF-alpha, IL-1 alpha, IL-1 beta, VEGF-A, VEGF-C, and VEGFR2. Animals treated with these mediators had significantly suppressed suture-induced or IL-1 beta-induced hemangiogenesis (HA) but not lymphangiogenesis. Interestingly, only the application of ATLa significantly suppressed VEGF-A-induced HA. ATLa, RvE1, and RvD1 all reduce inflammatory corneal HA by early regulation of resolution mechanisms in innate immune responses. In addition, ATLa directly inhibits VEGF-A-mediated angiogenesis and is the most potent inhibitor of NV among this new genus of dual anti-inflammatory and pro-resolving lipid mediators.
Cooperative ethylene receptor signaling

OpenAIRE

Liu, Qian; Wen, Chi-Kuang

2012-01-01

The gaseous plant hormone ethylene is perceived by a family of five ethylene receptor members in the dicotyledonous model plant Arabidopsis. Genetic and biochemical studies suggest that the ethylene response is suppressed by ethylene receptor complexes, but the biochemical nature of the receptor signal is unknown. Without appropriate biochemical measures to trace the ethylene receptor signal and quantify the signal strength, the biological significance of the modulation of ethylene responses ...
Quantifying Correlation Uncertainty Risk in Credit Derivatives Pricing

Directory of Open Access Journals (Sweden)

Colin Turfus

2018-04-01

Full Text Available We propose a simple but practical methodology for the quantification of correlation risk in the context of credit derivatives pricing and credit valuation adjustment (CVA, where the correlation between rates and credit is often uncertain or unmodelled. We take the rates model to be Hull–White (normal and the credit model to be Black–Karasinski (lognormal. We summarise recent work furnishing highly accurate analytic pricing formulae for credit default swaps (CDS including with defaultable Libor flows, extending this to the situation where they are capped and/or floored. We also consider the pricing of contingent CDS with an interest rate swap underlying. We derive therefrom explicit expressions showing how the dependence of model prices on the uncertain parameter(s can be captured in analytic formulae that are readily amenable to computation without recourse to Monte Carlo or lattice-based computation. In so doing, we crucially take into account the impact on model calibration of the uncertain (or unmodelled parameters.
Modeling of non-steroidal anti-inflammatory drug effect within signaling pathways and miRNA-regulation pathways.

Directory of Open Access Journals (Sweden)

Jian Li

Full Text Available To date, it is widely recognized that Non-Steroidal Anti-Inflammatory Drugs (NSAIDs can exert considerable anti-tumor effects regarding many types of cancers. The prolonged use of NSAIDs is highly associated with diverse side effects. Therefore, tailoring down the NSAID application onto individual patients has become a necessary and relevant step towards personalized medicine. This study conducts the systemsbiological approach to construct a molecular model (NSAID model containing a cyclooxygenase (COX-pathway and its related signaling pathways. Four cancer hallmarks are integrated into the model to reflect different developmental aspects of tumorigenesis. In addition, a Flux-Comparative-Analysis (FCA based on Petri net is developed to transfer the dynamic properties (including drug responsiveness of individual cellular system into the model. The gene expression profiles of different tumor-types with available drug-response information are applied to validate the predictive ability of the NSAID model. Moreover, two therapeutic developmental strategies, synthetic lethality and microRNA (miRNA biomarker discovery, are investigated based on the COX-pathway. In conclusion, the result of this study demonstrates that the NSAID model involving gene expression, gene regulation, signal transduction, protein interaction and other cellular processes, is able to predict the individual cellular responses for different therapeutic interventions (such as NS-398 and COX-2 specific siRNA inhibition. This strongly indicates that this type of model is able to reflect the physiological, developmental and pathological processes of an individual. The approach of miRNA biomarker discovery is demonstrated for identifying miRNAs with oncogenic and tumor suppressive functions for individual cell lines of breast-, colon- and lung-tumor. The achieved results are in line with different independent studies that investigated miRNA biomarker related to diagnostics of cancer
Phase synchronization of instrumental music signals

Science.gov (United States)

Mukherjee, Sayan; Palit, Sanjay Kumar; Banerjee, Santo; Ariffin, M. R. K.; Bhattacharya, D. K.

2014-06-01

Signal analysis is one of the finest scientific techniques in communication theory. Some quantitative and qualitative measures describe the pattern of a music signal, vary from one to another. Same musical recital, when played by different instrumentalists, generates different types of music patterns. The reason behind various patterns is the psycho-acoustic measures - Dynamics, Timber, Tonality and Rhythm, varies in each time. However, the psycho-acoustic study of the music signals does not reveal any idea about the similarity between the signals. For such cases, study of synchronization of long-term nonlinear dynamics may provide effective results. In this context, phase synchronization (PS) is one of the measures to show synchronization between two non-identical signals. In fact, it is very critical to investigate any other kind of synchronization for experimental condition, because those are completely non identical signals. Also, there exists equivalence between the phases and the distances of the diagonal line in Recurrence plot (RP) of the signals, which is quantifiable by the recurrence quantification measure τ-recurrence rate. This paper considers two nonlinear music signals based on same raga played by two eminent sitar instrumentalists as two non-identical sources. The psycho-acoustic study shows how the Dynamics, Timber, Tonality and Rhythm vary for the two music signals. Then, long term analysis in the form of phase space reconstruction is performed, which reveals the chaotic phase spaces for both the signals. From the RP of both the phase spaces, τ-recurrence rate is calculated. Finally by the correlation of normalized tau-recurrence rate of their 3D phase spaces and the PS of the two music signals has been established. The numerical results well support the analysis.
Interference Cancellation Technique Based on Discovery of Spreading Codes of Interference Signals and Maximum Correlation Detection for DS-CDMA System

Science.gov (United States)

Hettiarachchi, Ranga; Yokoyama, Mitsuo; Uehara, Hideyuki

This paper presents a novel interference cancellation (IC) scheme for both synchronous and asynchronous direct-sequence code-division multiple-access (DS-CDMA) wireless channels. In the DS-CDMA system, the multiple access interference (MAI) and the near-far problem (NFP) are the two factors which reduce the capacity of the system. In this paper, we propose a new algorithm that is able to detect all interference signals as an individual MAI signal by maximum correlation detection. It is based on the discovery of all the unknowing spreading codes of the interference signals. Then, all possible MAI patterns so called replicas are generated as a summation of interference signals. And the true MAI pattern is found by taking correlation between the received signal and the replicas. Moreover, the receiver executes MAI cancellation in a successive manner, removing all interference signals by single-stage. Numerical results will show that the proposed IC strategy, which alleviates the detrimental effect of the MAI and the near-far problem, can significantly improve the system performance. Especially, we can obtain almost the same receiving characteristics as in the absense of interference for asynchrnous system when received powers are equal. Also, the same performances can be seen under any received power state for synchronous system.
Whole-body vibration improves the anti-inflammatory status in elderly subjects through toll-like receptor 2 and 4 signaling pathways.

Science.gov (United States)

Rodriguez-Miguelez, Paula; Fernandez-Gonzalo, Rodrigo; Collado, Pilar S; Almar, Mar; Martinez-Florez, Susana; de Paz, José A; González-Gallego, Javier; Cuevas, María J

2015-09-01

Regular physical exercise has anti-inflammatory effects in elderly subjects. Yet, the inflammatory responses after whole body vibration (WBV) training, a popular exercise paradigm for the elderly, remain to be elucidated. This study assessed the effects of WBV training on the inflammatory response associated with toll-like receptors (TLRs) signaling pathways. Twenty-eight subjects were randomized to a training group (TG) or a control group (CG). TG followed an 8-week WBV training program. Blood samples were obtained before and after the training period in both groups. Peripheral blood mononuclear cells were isolated, and mRNA and protein levels of makers involved in the TLR2/TLR4 myeloid differentiation primary response gen 88 (MyD88) and TIR domain-containing adaptor inducing interferon (TRIF)-dependent pathways were analyzed. Plasma TNFα and C-reactive protein levels were also assessed. The WBV program reduced protein expression of TLR2, TLR4, MyD88, p65, TRIF and heat shock protein (HSP) 60, while HSP70 content increased. IL-10 mRNA level and protein concentration were upregulated, and TNFα protein content decreased, after WBV training. Plasma concentration of C-reactive protein and TNFα decreased in the TG. The current data suggest WBV may improve the anti-inflammatory status of elderly subjects through an attenuation of MyD88- and TRIF-dependent TLRs signaling pathways. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Control mechanism to prevent correlated message arrivals from degrading signaling no. 7 network performance

Science.gov (United States)

Kosal, Haluk; Skoog, Ronald A.

1994-04-01

Signaling System No. 7 (SS7) is designed to provide a connection-less transfer of signaling messages of reasonable length. Customers having access to user signaling bearer capabilities as specified in the ANSI T1.623 and CCITT Q.931 standards can send bursts of correlated messages (e.g., by doing a file transfer that results in the segmentation of a block of data into a number of consecutive signaling messages) through SS7 networks. These message bursts with short interarrival times could have an adverse impact on the delay performance of the SS7 networks. A control mechanism, Credit Manager, is investigated in this paper to regulate incoming traffic to the SS7 network by imposing appropriate time separation between messages when the incoming stream is too bursty. The credit manager has a credit bank where credits accrue at a fixed rate up to a prespecified credit bank capacity. When a message arrives, the number of octets in that message is compared to the number of credits in the bank. If the number of credits is greater than or equal to the number of octets, then the message is accepted for transmission and the number of credits in the bank is decremented by the number of octets. If the number of credits is less than the number of octets, then the message is delayed until enough credits are accumulated. This paper presents simulation results showing delay performance of the SS7 ISUP and TCAP message traffic with a range of correlated message traffic, and control parameters of the credit manager (i.e., credit generation rate and bank capacity) are determined that ensure the traffic entering the SS7 network is acceptable. The results show that control parameters can be set so that for any incoming traffic stream there is no detrimental impact on the SS7 ISUP and TCAP message delay, and the credit manager accepts a wide range of traffic patterns without causing significant delay.
Tracking molecular dynamics without tracking: image correlation of photo-activation microscopy

International Nuclear Information System (INIS)

Pandžić, Elvis; Rossy, Jérémie; Gaus, Katharina

2015-01-01

Measuring protein dynamics in the plasma membrane can provide insights into the mechanisms of receptor signaling and other cellular functions. To quantify protein dynamics on the single molecule level over the entire cell surface, sophisticated approaches such as single particle tracking (SPT), photo-activation localization microscopy (PALM) and fluctuation-based analysis have been developed. However, analyzing molecular dynamics of fluorescent particles with intermittent excitation and low signal-to-noise ratio present at high densities has remained a challenge. We overcame this problem by applying spatio-temporal image correlation spectroscopy (STICS) analysis to photo-activated (PA) microscopy time series. In order to determine under which imaging conditions this approach is valid, we simulated PA images of diffusing particles in a homogeneous environment and varied photo-activation, reversible blinking and irreversible photo-bleaching rates. Further, we simulated data with high particle densities that populated mobile objects (such as adhesions and vesicles) that often interfere with STICS and fluctuation-based analysis. We demonstrated in experimental measurements that the diffusion coefficient of the epidermal growth factor receptor (EGFR) fused to PAGFP in live COS-7 cells can be determined in the plasma membrane and revealed differences in the time-dependent diffusion maps between wild-type and mutant Lck in activated T cells. In summary, we have developed a new analysis approach for live cell photo-activation microscopy data based on image correlation spectroscopy to quantify the spatio-temporal dynamics of single proteins. (paper)
Tracking molecular dynamics without tracking: image correlation of photo-activation microscopy

Science.gov (United States)

Pandžić, Elvis; Rossy, Jérémie; Gaus, Katharina

2015-03-01

Measuring protein dynamics in the plasma membrane can provide insights into the mechanisms of receptor signaling and other cellular functions. To quantify protein dynamics on the single molecule level over the entire cell surface, sophisticated approaches such as single particle tracking (SPT), photo-activation localization microscopy (PALM) and fluctuation-based analysis have been developed. However, analyzing molecular dynamics of fluorescent particles with intermittent excitation and low signal-to-noise ratio present at high densities has remained a challenge. We overcame this problem by applying spatio-temporal image correlation spectroscopy (STICS) analysis to photo-activated (PA) microscopy time series. In order to determine under which imaging conditions this approach is valid, we simulated PA images of diffusing particles in a homogeneous environment and varied photo-activation, reversible blinking and irreversible photo-bleaching rates. Further, we simulated data with high particle densities that populated mobile objects (such as adhesions and vesicles) that often interfere with STICS and fluctuation-based analysis. We demonstrated in experimental measurements that the diffusion coefficient of the epidermal growth factor receptor (EGFR) fused to PAGFP in live COS-7 cells can be determined in the plasma membrane and revealed differences in the time-dependent diffusion maps between wild-type and mutant Lck in activated T cells. In summary, we have developed a new analysis approach for live cell photo-activation microscopy data based on image correlation spectroscopy to quantify the spatio-temporal dynamics of single proteins.
Experimental determination of the complete spin structure for anti-proton + proton -> anti-\\Lambda + \\Lambda at anti-proton beam momentum of 1.637 GeV/c

CERN Document Server

Paschke, K.D.; Berdoz, A.; Franklin, G.B.; Khaustov, P.; Meyer, C.A.; Bradtke, C.; Gehring, R.; Goertz, S.; Harmsen, J.; Meier, A.; Meyer, W.; Radtke, E.; Reicherz, G.; Dutz, H.; Pluckthun, M.; Schoch, B.; Dennert, H.; Eyrich, W.; Hauffe, J.; Metzger, A.; Moosburger, M.; Stinzing, F.; Wirth, St.; Fischer, H.; Franz, J.; Heinsius, F.H.; Kriegler, E.; Schmitt, H.; Bunker, B.; Hertzog, D.; Jones, T.; Tayloe, R.; Broders, R.; Geyer, R.; Kilian, K.; Oelert, W.; Rohrich, K.; Sachs, K.; Sefzick, T.; Bassalleck, B.; Eilerts, S.; Fields, D.E.; Kingsberry, P.; Lowe, J.; Stotzer, R.; Johansson, T.; Pomp, S.; Wirth, St.

2006-01-01

The reaction anti-proton + proton -> anti-\\Lambda + \\Lambda -> anti-proton + \\pi^+ + proton + \\pi^- has been measured with high statistics at anti-proton beam momentum of 1.637 GeV/c. The use of a transversely-polarized frozen-spin target combined with the self-analyzing property of \\Lambda/anti-\\Lambda decay allows access to unprecedented information on the spin structure of the interaction. The most general spin-scattering matrix can be written in terms of eleven real parameters for each bin of scattering angle, each of these parameters is determined with reasonable precision. From these results all conceivable spin-correlations are determined with inherent self-consistency. Good agreement is found with the few previously existing measurements of spin observables in anti-proton + proton -> anti-\\Lambda + \\Lambda near this energy. Existing theoretical models do not give good predictions for those spin-observables that had not been previously measured.
Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: implications for resilience

Directory of Open Access Journals (Sweden)

Emma Göthe

2014-09-01

Full Text Available The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.
Analysis of foot structural damage in rheumatoid arthritis: clinical evaluation by validated measures and serological correlations

Directory of Open Access Journals (Sweden)

E. Bartoloni Bocci

2011-06-01

Full Text Available Objective: To examine foot involvement in rheumatoid arthritis (RA and to characterize structural alterations in patients with anti-cyclic citrullinated peptide (CCP antibody-positive and -negative disease. Methods: Seventy-eight patients with RA with foot pain were consecutively enrolled. The Manchester Hallux Valgus (MHV rating scale was used to evaluate the hallux valgus deformity degree. The Foot Posture Index (FPI6, a novel, foot-specific outcome measure, was adopted in order to quantify variation in the position of the foot. The findings were correlated with disease duration and presence or absence of anti-CCP antibodies. Results: About 84.6% patients had different degrees of hallux valgus and 65.4% subjects had a pronated foot. These two foot alterations were prevalently found in patients with long-standing disease and circulating anti-CCP antibodies. On the contrary, RA patients without anti-CCP and early disease essentially displayed a supinated foot without relevant hallux valgus deformity. Conclusion: Our findings allowed to identify different anatomic foot alterations in RA patients according to disease duration and negative prognostic factors such as anti-CCP antibodies. Our findings support the role of an accurate analysis of foot structural damage and may suggest the usefulness of a correct plantar orthosis prescription also in early phases of the disease.

Designing a neurofeedback device to quantify attention levels using coffee as a reward system.

Science.gov (United States)

Cheng, Kok Suen; Lee, Jun Xiang; Lee, Poh Foong

2018-05-09

Work performance is closely related to one's attention level. In this study, a brain-computer interface (BCI) device suitable for office usage was chosen to quantify the individual's attention levels. A BCI system was adopted to interface brainwave signals to a coffee maker via three ascending levels of laser detectors. The preliminary test with this prototype was to characterize the attention level through the collected coffee amount. Here, the preliminary testing was comparing the correlation between the attention level and the participants' cumulative grade point average (CGPA) and scores from the 21-item depression, anxiety, and stress scale (DASS-21) and the attentional control scale (ACS) using ordinal regression. It was assumed that a greater CGPA would generate a greater attention level. The generated coffee amount from the BCI system had a significant positive correlation with the CGPA (p = 0.004), mild depression (p = 0.019) and mild and extremely severe anxiety (p = 0.044 and p = 0.019, respectively) and a negative correlation with the ACS score (p = 0.042). This simple and cost-effective prototype has the potential to enable everyone to know their immediate attention level and predict the possible correlation to their mental state.
Low order anti-aliasing filters for sparse signals in embedded ...

Indian Academy of Sciences (India)

The computation load increases only linearly with the number of signals, N since the ... We have considered, for simulation, the simple case of acquiring two signals .... Oppenheim A V and Schafer R W 1989 Discrete-time signal processing.
MRI signal changes of the bone marrow in HIV-infected patients with lipodystrophy: correlation with clinical parameters

International Nuclear Information System (INIS)

Garcia, Ana I.; Tomas, Xavier; Pomes, Jaume; Amo, Montserrat del; Milinkovic, Ana; Perez, Inaki; Mallolas, Josep; Rios, Jose; Vidal-Sicart, Sergi

2011-01-01

To assess the prevalence, imaging appearance, and clinical significance, of bone marrow MR signal changes in a group of human immunodeficiency virus (HIV)-infected patients with lipodystrophy syndrome. Twenty-eight HIV-infected patients with lipodystrophy syndrome treated with highly active antiretroviral therapy, and 12 HIV-negative controls underwent MRI of the legs. Whole-body MRI, SPECT/CT, and a complete radiographic skeletal survey were obtained in subjects with signal changes in bone marrow. MRI and clinical evaluations were reviewed 6 months after baseline to determine changes after switching from thymidine analogs (TA) to tenofovir-DF (TDF). MRI results correlated with clinical parameters. We observed foci of a serous-like pattern (low signal and no enhancement on T1-weighted, high signal on T2-weighted images) in 4 out of 28 patients (14.3%) and an intermediate signal on T1-weighted images in 4 out of 28 patients (14.3%). Serous-like lesions were located in the lower limbs and scattered in the talus, calcaneus, femurs, and humeral bones; they showed slight uptake on SPECT bone scans and were normal on CT and radiographs. Patients with serous-like lesions had significantly lower peripheral and total fat at baseline than other groups (P < 0.05). No changes at 6 months were observed on MRI, and the serous-like lesion group showed good peripheral fat recovery after changing drug treatment. A serous-like MRI pattern is observed in the peripheral skeletons of HIV-infected patients with lipodystrophy, which correlates with peripheral lipoatrophy, and should not be misdiagnosed as malignant or infectious diseases. Although the MR lesions did not improve after switching the treatment, there was evidence of lipoatrophy recovery. (orig.)
Quantifying uncertainty in soot volume fraction estimates using Bayesian inference of auto-correlated laser-induced incandescence measurements

Science.gov (United States)

Hadwin, Paul J.; Sipkens, T. A.; Thomson, K. A.; Liu, F.; Daun, K. J.

2016-01-01

Auto-correlated laser-induced incandescence (AC-LII) infers the soot volume fraction (SVF) of soot particles by comparing the spectral incandescence from laser-energized particles to the pyrometrically inferred peak soot temperature. This calculation requires detailed knowledge of model parameters such as the absorption function of soot, which may vary with combustion chemistry, soot age, and the internal structure of the soot. This work presents a Bayesian methodology to quantify such uncertainties. This technique treats the additional "nuisance" model parameters, including the soot absorption function, as stochastic variables and incorporates the current state of knowledge of these parameters into the inference process through maximum entropy priors. While standard AC-LII analysis provides a point estimate of the SVF, Bayesian techniques infer the posterior probability density, which will allow scientists and engineers to better assess the reliability of AC-LII inferred SVFs in the context of environmental regulations and competing diagnostics.
Cross-correlations between Renminbi and four major currencies in the Renminbi currency basket

Science.gov (United States)

Wang, Gang-Jin; Xie, Chi

2013-03-01

We investigate the cross-correlations between Renminbi (CNY) and four major currencies (USD, EUR, JPY, and KRW) in the Renminbi currency basket, i.e., the cross-correlations of CNY-USD, CNY-EUR, CNY-JPY, and CNY-KRW. Qualitatively, using a statistical test in analogy to the Ljung-Box test, we find that cross-correlations significantly exist in CNY-USD, CNY-EUR, CNY-JPY, and CNY-KRW. Quantitatively, employing the detrended cross-correlation analysis (DCCA) method, we find that the cross-correlations of CNY-USD, CNY-EUR, CNY-JPY, and CNY-KRW are weakly persistent. We use the DCCA cross-correlation coefficient ρ to quantify the level of cross-correlations and find the currency weight in the Renminbi currency basket is arranged in the order of USD>EUR>JPY >KRW. Using the method of rolling windows, which can capture the time-varying cross-correlation scaling exponents, we find that: (i) CNY and USD are positively cross-correlated over time, but the cross-correlations of CNY-USD are anti-persistent during the US sub-prime crisis and the European debt crisis. (ii) The cross-correlation scaling exponents of CNY-EUR have the cyclical fluctuation with a nearly two-year cycle. (iii) CNY-JPY has long-term negative cross-correlations, during the European debt crisis, but CNY and KRW are positively cross-correlated.
Correlation between plasma endothelin-1 levels and severity of septic liver failure quantified by maximal liver function capacity (LiMAx test. A prospective study.

Directory of Open Access Journals (Sweden)

Magnus F Kaffarnik

Full Text Available To investigate the relationship between the degree of liver dysfunction, quantified by maximal liver function capacity (LiMAx test and endothelin-1, TNF-α and IL-6 in septic surgical patients.28 septic patients (8 female, 20 male, age range 35-80y were prospectively investigated on a surgical intensive care unit. Liver function, defined by LiMAx test, and measurements of plasma levels of endothelin-1, TNF-α and IL-6 were carried out within the first 24 hours after onset of septic symptoms, followed by day 2, 5 and 10. Patients were divided into 2 groups (group A: LiMAx ≥100 μg/kg/h, moderate liver dysfunction; group B: LiMAx <100 μg/kg/h, severe liver dysfunction for analysis and investigated regarding the correlation between endothelin-1 and the severity of liver failure, quantified by LiMAx test.Group B showed significant higher results for endothelin-1 than patients in group A (P = 0.01, d5; 0.02, d10. For TNF-α, group B revealed higher results than group A, with a significant difference on day 10 (P = 0.005. IL-6 showed a non-significant trend to higher results in group B. The Spearman's rank correlation coefficient revealed a significant correlation between LiMAx and endothelin-1 (-0.434; P <0.001, TNF-α (-0.515; P <0.001 and IL-6 (-0.590; P <0.001.Sepsis-related hepatic dysfunction is associated with elevated plasma levels of endothelin-1, TNF-α and IL-6. Low LiMAx results combined with increased endothelin-1 and TNF-α and a favourable correlation between LiMAx and cytokine values support the findings of a crucial role of Endothelin-1 and TNF-α in development of septic liver failure.
Di-Jet Conical Correlations Associated with Heavy Quark Jets in anti-de Sitter Space/Conformal Field Theory Correspondence

International Nuclear Information System (INIS)

Noronha, Jorge; Gyulassy, Miklos; Torrieri, Giorgio

2009-01-01

We show that far zone Mach and diffusion wake 'holograms' produced by supersonic strings in anti-de Sitter space/conformal field theory (AdS/CFT) correspondence do not lead to observable conical angular correlations in the strict N c →∞ supergravity limit if Cooper-Frye hadronization is assumed. However, a special nonequilibrium 'neck' zone near the jet is shown to produce an apparent sonic boom azimuthal angle distribution that is roughly independent of the heavy quark's velocity. Our results indicate that a measurement of the dependence of the away-side correlations on the velocity of associated identified heavy quark jets at the BNL Relativistic Heavy Ion Collider and CERN LHC will provide a direct test of the nonperturbative dynamics involved in the coupling between jets and the strongly coupled quark-gluon plasma implied by AdS/CFT correspondence
Di-jet conical correlations associated with heavy quark jets in anti-de sitter space/conformal field theory correspondence.

Science.gov (United States)

Noronha, Jorge; Gyulassy, Miklos; Torrieri, Giorgio

2009-03-13

We show that far zone Mach and diffusion wake "holograms" produced by supersonic strings in anti-de Sitter space/conformal field theory (AdS/CFT) correspondence do not lead to observable conical angular correlations in the strict N_{c}-->infinity supergravity limit if Cooper-Frye hadronization is assumed. However, a special nonequilibrium "neck" zone near the jet is shown to produce an apparent sonic boom azimuthal angle distribution that is roughly independent of the heavy quark's velocity. Our results indicate that a measurement of the dependence of the away-side correlations on the velocity of associated identified heavy quark jets at the BNL Relativistic Heavy Ion Collider and CERN LHC will provide a direct test of the nonperturbative dynamics involved in the coupling between jets and the strongly coupled quark-gluon plasma implied by AdS/CFT correspondence.
Toddlers' bias to look at average versus obese figures relates to maternal anti-fat prejudice.

Science.gov (United States)

Ruffman, Ted; O'Brien, Kerry S; Taumoepeau, Mele; Latner, Janet D; Hunter, John A

2016-02-01

Anti-fat prejudice (weight bias, obesity stigma) is strong, prevalent, and increasing in adults and is associated with negative outcomes for those with obesity. However, it is unknown how early in life this prejudice forms and the reasons for its development. We examined whether infants and toddlers might display an anti-fat bias and, if so, whether it was influenced by maternal anti-fat attitudes through a process of social learning. Mother-child dyads (N=70) split into four age groups participated in a preferential looking paradigm whereby children were presented with 10 pairs of average and obese human figures in random order, and their viewing times (preferential looking) for the figures were measured. Mothers' anti-fat prejudice and education were measured along with mothers' and fathers' body mass index (BMI) and children's television viewing time. We found that older infants (M=11months) had a bias for looking at the obese figures, whereas older toddlers (M=32months) instead preferred looking at the average-sized figures. Furthermore, older toddlers' preferential looking was correlated significantly with maternal anti-fat attitudes. Parental BMI, education, and children's television viewing time were unrelated to preferential looking. Looking times might signal a precursor to explicit fat prejudice socialized via maternal anti-fat attitudes. Copyright © 2015 Elsevier Inc. All rights reserved.
Analysis of Maneuvering Targets with Complex Motions by Two-Dimensional Product Modified Lv's Distribution for Quadratic Frequency Modulation Signals.

Science.gov (United States)

Jing, Fulong; Jiao, Shuhong; Hou, Changbo; Si, Weijian; Wang, Yu

2017-06-21

For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM) signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR) and the quadratic chirp rate (QCR) are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed. In this paper, by employing a novel multi-scale parametric symmetric self-correlation function (PSSF) and modified scaled Fourier transform (mSFT), an effective parameter estimation algorithm is proposed-referred to as the Two-Dimensional product modified Lv's distribution (2D-PMLVD)-for QFM signals. The 2D-PMLVD is simple and can be easily implemented by using fast Fourier transform (FFT) and complex multiplication. These measures are analyzed in the paper, including the principle, the cross term, anti-noise performance, and computational complexity. Compared to the other three representative methods, the 2D-PMLVD can achieve better anti-noise performance. The 2D-PMLVD, which is free of searching and has no identifiability problems, is more suitable for multicomponent situations. Through several simulations and analyses, the effectiveness of the proposed estimation algorithm is verified.
Correlation of Serum Anti- Helicobacter pylori Immunoglobulin A (IGA)

African Journals Online (AJOL)

Background: The seroprevalence of anti-H. pylori IgA antibodies has been reported to vary among populations and in relation to strains of Helicobacter pylori bacterium. However, there has been conflicting reports on the association between IgA serological status and the histological variables of chronic gastritis. This study ...
Problem of quantifying quantum correlations with non-commutative discord

Science.gov (United States)

Majtey, A. P.; Bussandri, D. G.; Osán, T. M.; Lamberti, P. W.; Valdés-Hernández, A.

2017-09-01

In this work we analyze a non-commutativity measure of quantum correlations recently proposed by Guo (Sci Rep 6:25241, 2016). By resorting to a systematic survey of a two-qubit system, we detected an undesirable behavior of such a measure related to its representation-dependence. In the case of pure states, this dependence manifests as a non-satisfactory entanglement measure whenever a representation other than the Schmidt's is used. In order to avoid this basis-dependence feature, we argue that a minimization procedure over the set of all possible representations of the quantum state is required. In the case of pure states, this minimization can be analytically performed and the optimal basis turns out to be that of Schmidt's. In addition, the resulting measure inherits the main properties of Guo's measure and, unlike the latter, it reduces to a legitimate entanglement measure in the case of pure states. Some examples involving general mixed states are also analyzed considering such an optimization. The results show that, in most cases of interest, the use of Guo's measure can result in an overestimation of quantum correlations. However, since Guo's measure has the advantage of being easily computable, it might be used as a qualitative estimator of the presence of quantum correlations.
Simultaneous Chandra and VLA Observations of the Transitional Millisecond Pulsar PSR J1023+0038: Anti-correlated X-Ray and Radio Variability

Science.gov (United States)

Bogdanov, Slavko; Deller, Adam T.; Miller-Jones, James C. A.; Archibald, Anne M.; Hessels, Jason W. T.; Jaodand, Amruta; Patruno, Alessandro; Bassa, Cees; D’Angelo, Caroline

2018-03-01

We present coordinated Chandra X-ray Observatory and Karl G. Jansky Very Large Array observations of the transitional millisecond pulsar PSR J1023+0038 in its low-luminosity accreting state. The unprecedented five hours of strictly simultaneous X-ray and radio continuum coverage for the first time unambiguously show a highly reproducible, anti-correlated variability pattern. The characteristic switches from the X-ray high mode into a low mode are always accompanied by a radio brightening with a duration that closely matches the X-ray low mode interval. This behavior cannot be explained by a canonical inflow/outflow accretion model where the radiated emission and the jet luminosity are powered by, and positively correlated with, the available accretion energy. We interpret this phenomenology as alternating episodes of low-level accretion onto the neutron star during the X-ray high mode that are interrupted by rapid ejections of plasma by the active rotation-powered pulsar, possibly initiated by a reconfiguration of the pulsar magnetosphere, that cause a transition to a less X-ray luminous mode. The observed anti-correlation between radio and X-ray luminosity has an additional consequence: transitional MSPs can make excursions into a region of the radio/X-ray luminosity plane previously thought to be occupied solely by black hole X-ray binary sources. This complicates the use of this luminosity relation for identifying candidate black holes, suggesting the need for additional discriminants when attempting to establish the true nature of the accretor.
Quantifying the Arousal Threshold Using Polysomnography in Obstructive Sleep Apnea.

Science.gov (United States)

Sands, Scott A; Terrill, Philip I; Edwards, Bradley A; Taranto Montemurro, Luigi; Azarbarzin, Ali; Marques, Melania; de Melo, Camila M; Loring, Stephen H; Butler, James P; White, David P; Wellman, Andrew

2018-01-01

Precision medicine for obstructive sleep apnea (OSA) requires noninvasive estimates of each patient's pathophysiological "traits." Here, we provide the first automated technique to quantify the respiratory arousal threshold-defined as the level of ventilatory drive triggering arousal from sleep-using diagnostic polysomnographic signals in patients with OSA. Ventilatory drive preceding clinically scored arousals was estimated from polysomnographic studies by fitting a respiratory control model (Terrill et al.) to the pattern of ventilation during spontaneous respiratory events. Conceptually, the magnitude of the airflow signal immediately after arousal onset reveals information on the underlying ventilatory drive that triggered the arousal. Polysomnographic arousal threshold measures were compared with gold standard values taken from esophageal pressure and intraoesophageal diaphragm electromyography recorded simultaneously (N = 29). Comparisons were also made to arousal threshold measures using continuous positive airway pressure (CPAP) dial-downs (N = 28). The validity of using (linearized) nasal pressure rather than pneumotachograph ventilation was also assessed (N = 11). Polysomnographic arousal threshold values were correlated with those measured using esophageal pressure and diaphragm EMG (R = 0.79, p < .0001; R = 0.73, p = .0001), as well as CPAP manipulation (R = 0.73, p < .0001). Arousal threshold estimates were similar using nasal pressure and pneumotachograph ventilation (R = 0.96, p < .0001). The arousal threshold in patients with OSA can be estimated using polysomnographic signals and may enable more personalized therapeutic interventions for patients with a low arousal threshold. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
Quantifying Quantum-Mechanical Processes.

Science.gov (United States)

Hsieh, Jen-Hsiang; Chen, Shih-Hsuan; Li, Che-Ming

2017-10-19

The act of describing how a physical process changes a system is the basis for understanding observed phenomena. For quantum-mechanical processes in particular, the affect of processes on quantum states profoundly advances our knowledge of the natural world, from understanding counter-intuitive concepts to the development of wholly quantum-mechanical technology. Here, we show that quantum-mechanical processes can be quantified using a generic classical-process model through which any classical strategies of mimicry can be ruled out. We demonstrate the success of this formalism using fundamental processes postulated in quantum mechanics, the dynamics of open quantum systems, quantum-information processing, the fusion of entangled photon pairs, and the energy transfer in a photosynthetic pigment-protein complex. Since our framework does not depend on any specifics of the states being processed, it reveals a new class of correlations in the hierarchy between entanglement and Einstein-Podolsky-Rosen steering and paves the way for the elaboration of a generic method for quantifying physical processes.
Evaluation of Serum Fibrinogen, Plasminogen, α2-Anti-Plasmin, and Plasminogen Activator Inhibitor Levels (PAI and Their Correlation with Presence of Retinopathy in Patients with Type 1 DM

Directory of Open Access Journals (Sweden)

Sefika Burcak Polat

2014-01-01

Full Text Available Background. Diabetic retinopathy (DR is the leading cause of blindness in the world. Retinopathy can still progress despite optimal metabolic control. The aim of the study was to determine whether different degrees of DR (proliferative or nonproliferative were associated with abnormally modulated hemostatic parameters in patients with T1DM. Method. 52 T1DM patients and 40 healthy controls were enrolled in the study. Patients were subdivided into three categories. Group I was defined as those without retinopathy, group II with NPRP, and group III with PRP. We compared these subgroups with each other and the control group (Group IV according to the serum fibrinogen, plasminogen, alpha2-anti-plasmin (α2-anti-plasmin, and PAI. Results. We detected that PAI-1, serum fibrinogen, and plasminogen levels were similar between the diabetic and control groups (P=0.209, P=0.224, and P=0.244, resp., whereas α2-anti-plasmin was higher in Groups I, II, and III compared to the control group (P<0.01, P<0.05, and P<0.001, resp.. There was a positive correlation between serum α2-anti-plasmin and HbA1c levels (r=0,268, P=0.031. Conclusion. To our knowledge there is scarce data in the literature about α2-anti-plasmin levels in type 1 diabetes. A positive correlation between α2-anti-plasmin with HbA1c suggests that fibrinolytic markers may improve with disease regulation and better glycemic control.
Correlation between neurohypophyseal vasopressin content and signal intensity on T1-weighted magnetic resonance images. An experimental study of vasopressin depletion model using dehydrated rabbits

International Nuclear Information System (INIS)

Kurokawa, Hiroaki; Nakano, Yoshihisa; Ikeda, Koshi; Tanaka, Yoshimasa; Fujisawa, Ichiro

1998-01-01

We investigated the correlation between the signal intensity on T 1 -weighted MR images and vasopressin (VP) content in the posterior pituitary lobe. Fourteen rabbits were studied. There were 12 water-deprived rabbits (48, 72, 96, 120, 144 and 168 hours: 2 each) and 2 controls. Sagittal T 1 -weighted SE (spin-echo) MR images were obtained before and after dehydration. The signal intensity ratio of the posterior pituitary lobe to the pons was correlated with the VP content in the posterior lobe as measured by radioimmunoassay. Before water deprivation, high signal intensity in the posterior lobe was demonstrated clearly in all 14 rabbits. After water deprivation, the hyperintense signal gradually decreased and became indistinguishable from anterior lobe in four animals. The mean signal intensity ratio before water deprivation was 1.55±0.12 (mean±SD) and after water deprivation, gradually decreased over time and reached to 1.19 after 168 hours of water deprivation. Pituitary VP content and concentration decreased in parallel with the signal intensity ratio of the posterior pituitary. Significantly correlation was observed between the signal intensity ratio and VP concentration of posterior pituitary (r=0.809, p 1 -weighted image may reflect a indicator of pituitary VP content and thus may enable evaluation of disorders of water metabolism. (author)
Antioxidants Impair Anti-Tumoral Effects of Vorinostat, but Not Anti-Neoplastic Effects of Vorinostat and Caspase-8 Downregulation

OpenAIRE

Bergadà, Laura; Yeramian, Andree; Sorolla, Annabel; Matias-Guiu, Xavier; Dolcet, Xavier

2014-01-01

We have recently demonstrated that histone deacetylase inhibitor, Vorinostat, applied as a single therapy or in combination with caspase-8 downregulation exhibits high anti-tumoral activity on endometrial carcinoma cell lines. In the present study, we have assessed the signalling processes underlying anti-tumoral effects of Vorinostat. Increasing evidence suggests that reactive oxygen species are responsible for histone deacetylase inhibitor-induced cell killing. We have found that Vorinostat...
TIM-1 signaling in B cells regulates antibody production

International Nuclear Information System (INIS)

Ma, Juan; Usui, Yoshihiko; Takeda, Kazuyoshi; Harada, Norihiro; Yagita, Hideo; Okumura, Ko; Akiba, Hisaya

2011-01-01

Highlights: → TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. → Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. → TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3 + anti-CD28-stimulated CD4 + T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.
TIM-1 signaling in B cells regulates antibody production

Energy Technology Data Exchange (ETDEWEB)

Ma, Juan [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Usui, Yoshihiko [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Ophthalmology, Tokyo Medical University, 6-7-1 Nishi-shinjuku-ku, Tokyo 160-0023 (Japan); Takeda, Kazuyoshi [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Harada, Norihiro [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Respiratory Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Research Institute for Diseases of Old Ages, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Yagita, Hideo; Okumura, Ko [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Akiba, Hisaya, E-mail: hisaya@juntendo.ac.jp [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan)

2011-03-11

Highlights: {yields} TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. {yields} Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. {yields} TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3{sup +} anti-CD28-stimulated CD4{sup +} T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.

Packaging signals in single-stranded RNA viruses: nature's alternative to a purely electrostatic assembly mechanism.

Science.gov (United States)

Stockley, Peter G; Twarock, Reidun; Bakker, Saskia E; Barker, Amy M; Borodavka, Alexander; Dykeman, Eric; Ford, Robert J; Pearson, Arwen R; Phillips, Simon E V; Ranson, Neil A; Tuma, Roman

2013-03-01

The formation of a protective protein container is an essential step in the life-cycle of most viruses. In the case of single-stranded (ss)RNA viruses, this step occurs in parallel with genome packaging in a co-assembly process. Previously, it had been thought that this process can be explained entirely by electrostatics. Inspired by recent single-molecule fluorescence experiments that recapitulate the RNA packaging specificity seen in vivo for two model viruses, we present an alternative theory, which recognizes the important cooperative roles played by RNA-coat protein interactions, at sites we have termed packaging signals. The hypothesis is that multiple copies of packaging signals, repeated according to capsid symmetry, aid formation of the required capsid protein conformers at defined positions, resulting in significantly enhanced assembly efficiency. The precise mechanistic roles of packaging signal interactions may vary between viruses, as we have demonstrated for MS2 and STNV. We quantify the impact of packaging signals on capsid assembly efficiency using a dodecahedral model system, showing that heterogeneous affinity distributions of packaging signals for capsid protein out-compete those of homogeneous affinities. These insights pave the way to a new anti-viral therapy, reducing capsid assembly efficiency by targeting of the vital roles of the packaging signals, and opens up new avenues for the efficient construction of protein nanocontainers in bionanotechnology.
From micro-correlations to macro-correlations

International Nuclear Information System (INIS)

Eliazar, Iddo

2016-01-01

Random vectors with a symmetric correlation structure share a common value of pair-wise correlation between their different components. The symmetric correlation structure appears in a multitude of settings, e.g. mixture models. In a mixture model the components of the random vector are drawn independently from a general probability distribution that is determined by an underlying parameter, and the parameter itself is randomized. In this paper we study the overall correlation of high-dimensional random vectors with a symmetric correlation structure. Considering such a random vector, and terming its pair-wise correlation “micro-correlation”, we use an asymptotic analysis to derive the random vector’s “macro-correlation” : a score that takes values in the unit interval, and that quantifies the random vector’s overall correlation. The method of obtaining macro-correlations from micro-correlations is then applied to a diverse collection of frameworks that demonstrate the method’s wide applicability.
Involvement of PKA and HO-1 signaling in anti-inflammatory effects of surfactin in BV-2 microglial cells

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Park, Sun Young; Kim, Ji-Hee [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of); Lee, Sang Joon [Department of Microbiology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of); Kim, YoungHee, E-mail: yheekim@pusan.ac.kr [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of)

2013-04-01

Surfactin, one of the most powerful biosurfactants, is a bacterial cyclic lipopeptide. Here, we investigated the anti-neuroinflammatory properties of surfactin in lipoteichoic acid (LTA)-stimulated BV-2 microglial cells. Surfactin significantly inhibited excessive production of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), prostaglandin E{sub 2} (PGE{sub 2}), nitric oxide (NO) and reactive oxygen species (ROS), and suppressed the expression of matrix metalloproteinase-9 (MMP-9), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequent mechanistic studies revealed that surfactin inhibited LTA-induced nuclear factor-kappaB (NF-κB) and signal transducer and activator of transcription-1 (STAT-1) activation. However, surfactin increases the phosphorylation of the STAT-3, a component of the homeostatic mechanism causing anti-inflammatory events. We also demonstrated that surfactin induces heme oxygenase-1 (HO-1) expression and nuclear factor-regulated factor-2 (Nrf-2) activation, and that the anti-inflammatory effects of surfactin are abrogated by small interfering RNA-mediated knock-down of HO-1 or Nrf-2. Interestingly, we found that surfactin increased the level of cAMP and induced phosphorylation of cAMP responsive element binding protein (CREB) in microglial cells. Furthermore, treatment with the protein kinase A (PKA) inhibitor, H-89, blocked HO-1 induction by surfactin and abolished surfactin's suppressive effects on ROS and NO production. These results indicate that HO-1 and its upstream effector, PKA, play a pivotal role in the anti-neuroinflammatory response of surfactin in LTA-stimulated microglia. Therefore, surfactin might have therapeutic potential for neuroprotective agents to treat inflammatory and neurodegenerative diseases. - Highlights: ► Surfactin inhibits proinflammatory mediator synthesis in LTA-activated BV-2 cells. ► Surfactin suppresses NF-κB and STAT-1, but potentiates
Involvement of PKA and HO-1 signaling in anti-inflammatory effects of surfactin in BV-2 microglial cells

International Nuclear Information System (INIS)

Park, Sun Young; Kim, Ji-Hee; Lee, Sang Joon; Kim, YoungHee

2013-01-01

Surfactin, one of the most powerful biosurfactants, is a bacterial cyclic lipopeptide. Here, we investigated the anti-neuroinflammatory properties of surfactin in lipoteichoic acid (LTA)-stimulated BV-2 microglial cells. Surfactin significantly inhibited excessive production of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), prostaglandin E 2 (PGE 2 ), nitric oxide (NO) and reactive oxygen species (ROS), and suppressed the expression of matrix metalloproteinase-9 (MMP-9), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequent mechanistic studies revealed that surfactin inhibited LTA-induced nuclear factor-kappaB (NF-κB) and signal transducer and activator of transcription-1 (STAT-1) activation. However, surfactin increases the phosphorylation of the STAT-3, a component of the homeostatic mechanism causing anti-inflammatory events. We also demonstrated that surfactin induces heme oxygenase-1 (HO-1) expression and nuclear factor-regulated factor-2 (Nrf-2) activation, and that the anti-inflammatory effects of surfactin are abrogated by small interfering RNA-mediated knock-down of HO-1 or Nrf-2. Interestingly, we found that surfactin increased the level of cAMP and induced phosphorylation of cAMP responsive element binding protein (CREB) in microglial cells. Furthermore, treatment with the protein kinase A (PKA) inhibitor, H-89, blocked HO-1 induction by surfactin and abolished surfactin's suppressive effects on ROS and NO production. These results indicate that HO-1 and its upstream effector, PKA, play a pivotal role in the anti-neuroinflammatory response of surfactin in LTA-stimulated microglia. Therefore, surfactin might have therapeutic potential for neuroprotective agents to treat inflammatory and neurodegenerative diseases. - Highlights: ► Surfactin inhibits proinflammatory mediator synthesis in LTA-activated BV-2 cells. ► Surfactin suppresses NF-κB and STAT-1, but potentiates phosphorylation
Time of correlation of low-frequency fluctuations in the regional laser Doppler flow signal from human skin

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Folgosi-Correa, M. S.; Nogueira, G. E. C.

2012-06-01

The laser Doppler flowmetry allows the non-invasive assessment of the skin perfusion in real-time, being an attractive technique to study the human microcirculation in clinical settings. Low-frequency oscillations in the laser Doppler blood flow signal from the skin have been related to the endothelial, endothelial-metabolic, neurogenic and myogenic mechanisms of microvascular flow control, in the range 0.005-0.0095 Hz, 0.0095-0.021 Hz, 0.021-0.052 Hz and 0.052- 0.145 Hz respectively. The mean Amplitude (A) of the periodic fluctuations in the laser Doppler blood flow signal, in each frequency range, derived from the respective wavelet-transformed coefficients, has been used to assess the function and dysfunctions of each mechanism of flow control. Known sources of flow signal variances include spatial and temporal variability, diminishing the discriminatory capability of the technique. Here a new time domain method of analysis is proposed, based on the Time of Correlation (TC) of flow fluctuations between two adjacent sites. Registers of blood flow from two adjacent regions, for skin temperature at 32 0C (basal) and thermally stimulated (42 0C) of volar forearms from 20 healthy volunteers were collected and analyzed. The results obtained revealed high time of correlation between two adjacent regions when thermally stimulated, for signals in the endothelial, endothelial-metabolic, neurogenic and myogenic frequency ranges. Experimental data also indicate lower variability for TC when compared to A, when thermally stimulated, suggesting a new promising parameter for assessment of the microvascular flow control.
Correlative SEM SERS for quantitative analysis of dimer nanoparticles.

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Timmermans, F J; Lenferink, A T M; van Wolferen, H A G M; Otto, C

2016-11-14

A Raman microscope integrated with a scanning electron microscope was used to investigate plasmonic structures by correlative SEM-SERS analysis. The integrated Raman-SEM microscope combines high-resolution electron microscopy information with SERS signal enhancement from selected nanostructures with adsorbed Raman reporter molecules. Correlative analysis is performed for dimers of two gold nanospheres. Dimers were selected on the basis of SEM images from multi aggregate samples. The effect of the orientation of the dimer with respect to the polarization state of the laser light and the effect of the particle gap size on the Raman signal intensity is observed. Additionally, calculations are performed to simulate the electric near field enhancement. These simulations are based on the morphologies observed by electron microscopy. In this way the experiments are compared with the enhancement factor calculated with near field simulations and are subsequently used to quantify the SERS enhancement factor. Large differences between experimentally observed and calculated enhancement factors are regularly detected, a phenomenon caused by nanoscale differences between the real and 'simplified' simulated structures. Quantitative SERS experiments reveal the structure induced enhancement factor, ranging from ∼200 to ∼20 000, averaged over the full nanostructure surface. The results demonstrate correlative Raman-SEM microscopy for the quantitative analysis of plasmonic particles and structures, thus enabling a new analytical method in the field of SERS and plasmonics.
Anti-HIV activity in cervical-vaginal secretions from HIV-positive and -negative women correlate with innate antimicrobial levels and IgG antibodies.

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Mimi Ghosh

2010-06-01

Full Text Available We investigated the impact of antimicrobials in cervicovaginal lavage (CVL from HIV(+ and HIV(- women on target cell infection with HIV. Since female reproductive tract (FRT secretions contain a spectrum of antimicrobials, we hypothesized that CVL from healthy HIV(+ and (- women inhibit HIV infection.CVL from 32 HIV(+ healthy women with high CD4 counts and 15 healthy HIV(- women were collected by gently washing the cervicovaginal area with 10 ml of sterile normal saline. Following centrifugation, anti-HIV activity in CVL was determined by incubating CVL with HIV prior to addition to TZM-bl cells. Antimicrobials and anti-gp160 HIV IgG antibodies were measured by ELISA. When CXCR4 and CCR5 tropic HIV-1 were incubated with CVL from HIV(+ women prior to addition to TZM-bl cells, anti-HIV activity in CVL ranged from none to 100% inhibition depending on the viral strains used. CVL from HIV(- controls showed comparable anti-HIV activity. Analysis of CH077.c (clone of an R5-tropic, mucosally-transmitted founder virus viral inhibition by CVL was comparable to laboratory strains. Measurement of CVL for antimicrobials HBD2, trappin-2/elafin, SLPI and MIP3alpha indicated that each was present in CVL from HIV(+ and HIV(- women. HBD2 and MIP3alpha correlated with anti-HIV activity as did anti-gp160 HIV IgG antibodies in CVL from HIV(+ women.These findings indicate that CVL from healthy HIV(+ and HIV(- women contain innate and adaptive defense mechanisms that inhibit HIV infection. Our data suggest that innate endogenous antimicrobials and HIV-specific IgG in the FRT can act in concert to contribute toward the anti-HIV activity of the CVL and may play a role in inhibition of HIV transmission to women.
Green's function for anti--de Sitter space gravity

International Nuclear Information System (INIS)

Kleppe, G.

1994-01-01

We solve for the retarded Green's function for linearized gravity in a background with a negative cosmological constant, anti--de Sitter space. In this background, it is possible for a signal to reach spatial infinity in a finite time. Therefore the form of the Green's function depends on a choice of boundary condition at spatial infinity. We take as our condition that a signal which reaches infinity should be lost, not reflected back. We calculate the Green's function associated with this condition, and show that it reproduces the correct classical solution for a point mass at the origin, the anti--de Sitter--Schwarzschild solution
Correlation between MEG and BOLD fMRI signals induced by visual flicker stimuli

Institute of Scientific and Technical Information of China (English)

Chu Renxin; Holroyd Tom; Duyn Jeff

2007-01-01

The goal of this work was to investigate how the MEG signal amplitude correlates with that of BOLD fMRI.To investigate the correlation between fMRI and macroscopic electrical activity, BOLD fMRI and MEG was performed on the same subjects (n =5). A visual flicker stimulus of varying temporal frequency was used to elicit neural responses in early visual areas. A strong similarity was observed in frequency tuning curves between both modalities.Although, averaged over subjects, the BOLD tuning curve was somewhat broader than MEG, both BOLD and MEG had maxima at a flicker frequency of 10 Hz. Also, we measured the first and second harmonic components as the stimuli frequency by MEG. In the low stimuli frequency (less than 6 Hz), the second harmonic has comparable amplitude with the first harmonic, which implies that neural frequency response is nonlinear and has more nonlinear components in low frequency than in high frequency.
Development and Characterization of a Humanized Anti-HER2 Antibody HuA21 with Potent Anti-Tumor Properties in Breast Cancer Cells

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Ruilin Li

2016-04-01

Full Text Available Human epidermal growth factor receptor 2 (HER2 is one of the most studied tumor-associated antigens for cancer immunotherapy. An engineered anti-HER-2 chimeric A21 antibody (chA21 is a chimeric antibody targeted to subdomain I of the HER2 extracellular domain. Here, we report the anti-tumor activity of the novel engineered monoclonal antibody humanized chA21 (HuA21 that targets HER2 on the basis of chA21, and we describe the underlying mechanisms. Our results reveal that HuA21 markedly inhibits the proliferation and migration of HER2-overexpressing breast cancer cells and causes enhanced antibody-dependent cell-mediated cytotoxicity potency against HER2-overexpressing tumor cells. In particular, HuA21, but not trastuzumab (Tra, markedly suppresses growth and enhances the internalization of the antibody in Tra-resistant BT-474 breast cancer cells. These characteristics are highly associated with the intrinsic ability of HuA21 to down-regulate HER2 activation and inhibit the extracellular signal-regulated kinase 1/2 (ERK1/2 and protein kinase B (Akt signaling pathways. Furthermore, the combination of HuA21 with Tra synergistically enhances the anti-tumor effects in vitro and in vivo and inhibits HER2 activation and the ERK1/2 and Akt signaling pathways. Altogether, our results suggest that HuA21 may represent a unique anti-HER2 antibody with potential as a therapeutic candidate alone or in combination with other anti-HER2 reagents in cancer therapy.
A Tensor Statistical Model for Quantifying Dynamic Functional Connectivity.

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Zhu, Yingying; Zhu, Xiaofeng; Kim, Minjeong; Yan, Jin; Wu, Guorong

2017-06-01

Functional connectivity (FC) has been widely investigated in many imaging-based neuroscience and clinical studies. Since functional Magnetic Resonance Image (MRI) signal is just an indirect reflection of brain activity, it is difficult to accurately quantify the FC strength only based on signal correlation. To address this limitation, we propose a learning-based tensor model to derive high sensitivity and specificity connectome biomarkers at the individual level from resting-state fMRI images. First, we propose a learning-based approach to estimate the intrinsic functional connectivity. In addition to the low level region-to-region signal correlation, latent module-to-module connection is also estimated and used to provide high level heuristics for measuring connectivity strength. Furthermore, sparsity constraint is employed to automatically remove the spurious connections, thus alleviating the issue of searching for optimal threshold. Second, we integrate our learning-based approach with the sliding-window technique to further reveal the dynamics of functional connectivity. Specifically, we stack the functional connectivity matrix within each sliding window and form a 3D tensor where the third dimension denotes for time. Then we obtain dynamic functional connectivity (dFC) for each individual subject by simultaneously estimating the within-sliding-window functional connectivity and characterizing the across-sliding-window temporal dynamics. Third, in order to enhance the robustness of the connectome patterns extracted from dFC, we extend the individual-based 3D tensors to a population-based 4D tensor (with the fourth dimension stands for the training subjects) and learn the statistics of connectome patterns via 4D tensor analysis. Since our 4D tensor model jointly (1) optimizes dFC for each training subject and (2) captures the principle connectome patterns, our statistical model gains more statistical power of representing new subject than current state
Anti-Inflammatory Activity of Bee Venom in BV2 Microglial Cells: Mediation of MyD88-Dependent NF-κB Signaling Pathway.

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Im, Eun Ju; Kim, Su Jung; Hong, Seung Bok; Park, Jin-Kyu; Rhee, Man Hee

2016-01-01

Bee venom has long been used as a traditional folk medicine in Korea. It has been reportedly used for the treatment of arthritis, cancer, and inflammation. Although its anti-inflammatory activity in lipopolysaccharide- (LPS-) stimulated inflammatory cells has been reported, the exact mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, the aim of this study was to investigate the anti-inflammatory mechanism of bee venom in BV2 microglial cells. We first investigated whether NO production in LPS-activated BV2 cells was inhibited by bee venom, and further iNOS mRNA and protein expressions were determined. The mRNA and protein levels of proinflammatory cytokines were examined using semiquantitative RT-PCR and immunoblotting, respectively. Moreover, modulation of the transcription factor NF-κB by bee venom was also investigated using a luciferase assay. LPS-induced NO production in BV2 microglial cells was significantly inhibited in a concentration-dependent manner upon pretreatment with bee venom. Bee venom markedly reduced the mRNA expression of COX-2, TNF-α, IL-1β, and IL-6 and suppressed LPS-induced activation of MyD88 and IRAK1 and phosphorylation of TAK1. Moreover, NF-κB translocation by IKKα/β phosphorylation and subsequent IκB-α degradation were also attenuated. Thus, collectively, these results indicate that bee venom exerts its anti-inflammatory activity via the IRAK1/TAK1/NF-κB signaling pathway.
[(Modic) signal alterations of vertebral endplates and their correlation to a minimally invasive treatment of lumbar disc herniation using epidural injections].

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Liphofer, J P; Theodoridis, T; Becker, G T; Koester, O; Schmid, G

2006-11-01

To study the influence of (Modic) signal alterations (SA) of the cartilage endplate (CEP) of vertebrae L3-S1 on the outcome of an in-patient minimally invasive treatment (MIT) using epidural injections on patients with lumbar disc herniation (LDH). The MR images of 59 consecutive patients with LDH within segments L3/L4 - L5/S1 undergoing in-patient minimally invasive treatment with epidural injections were evaluated in a clinical study. The (Modic) signal alterations of the CEP were recorded using T1- and T2-weighted sagittal images. On the basis of the T2-weighted sagittal images, the extension and distribution of the SA were measured by dividing each CEP into 9 areas. The outcome of the MIT was recorded using the Oswestry Disability Index (ODI) before and after therapy and in a 3-month follow-up. Within a subgroup of patients (n = 35), the distribution and extension of the signal alterations were correlated with the development of the ODI. Segments with LDH showed significantly more (p < 0.001) SA of the CEP than segments without LDH. Although the extension of the SA was not dependent on sex, it did increase significantly with age (p = 0.017). The outcome after MIT did not depend on the sex and age of the patients nor on the type of LDH. The SA extension tended to have a negative correlation with the outcome after MIT after 3 months (p = 0.071). A significant negative correlation could be established between the SA extension in the central section of the upper endplate and the outcome after 3 months (p = 0.019). 1. Lumbar disc herniation is clearly associated with the prevalence of (Modic) signal alterations. 2. Extensive signal alterations tend to correlate with a negative outcome of an MIT using epidural injections. 3. Such SA in the central portion of the upper CEP correlate significantly with a negative treatment result. 4. The central portion of the upper CEP being extensively affected by (Modic) SA is a negative predictor for the success of a minimally
Clinical input of anti-D quantitation by continuous-flow analysis on autoanalyzer in the management of high-titer anti-D maternal alloimmunization.

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Toly-Ndour, Cécile; Mourtada, Haifa; Huguet-Jacquot, Stéphanie; Maisonneuve, Emeline; Friszer, Stéphanie; Pernot, Françoise; Thomas, Pauline; Jouannic, Jean-Marie; Carbonne, Bruno; Cortey, Anne; Mailloux, Agnès

2018-02-01

In addition to titration by indirect antiglobulin test most widely used, anti-D quantitation by continuous-flow analysis (CFA) may be performed to assess severity of maternal immunization. Only five studies have reported its added value in the management of pregnancies complicated by anti-D immunization. A retrospective study of 74 severe anti-D-immunized pregnancies was conducted from January 1, 2013, to December 31, 2014, in the Trousseau Hospital in Paris (France). Concentration of maternal anti-D was measured by titration and by CFA two-stages method (2SM; total amount of anti-D) and one-stage method (1SM; high-affinity IgG1 anti-D). These biologic data were analyzed according to the severity of the hemolytic disease of the fetus and the newborn. The value of 5 IU anti-D/mL in maternal serum is validated as a threshold to trigger ultrasonographic and Doppler fetal close follow-up. A high 1SM/2SM ratio was associated with a higher risk of intrauterine transfusion (IUT). For pregnancies requiring IUT and without increasing titer, maternal 1SM anti-D concentration tends to correlate with the precocity of fetal anemia. In the "without-IUT" group 1SM and 2SM anti-D concentrations correlate significantly with cord bilirubin levels of the newborn at birth. Altogether our results underline the importance of anti-D quantitation by CFA to optimize the management of anti-D-alloimmunized pregnancies. © 2017 AABB.
Quorum Quenching Revisited—From Signal Decays to Signalling Confusion

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Kok-Gan Chan

2012-04-01

Full Text Available In a polymicrobial community, while some bacteria are communicating with neighboring cells (quorum sensing, others are interrupting the communication (quorum quenching, thus creating a constant arms race between intercellular communication. In the past decade, numerous quorum quenching enzymes have been found and initially thought to inactivate the signalling molecules. Though this is widely accepted, the actual roles of these quorum quenching enzymes are now being uncovered. Recent evidence extends the role of quorum quenching to detoxification or metabolism of signalling molecules as food and energy source; this includes “signalling confusion”, a term coined in this paper to refer to the phenomenon of non-destructive modification of signalling molecules. While quorum quenching has been explored as a novel anti-infective therapy targeting, quorum sensing evidence begins to show the development of resistance against quorum quenching.
The role of neuroimmune signaling in alcoholism.

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Crews, Fulton T; Lawrimore, Colleen J; Walter, T Jordan; Coleman, Leon G

2017-08-01

Alcohol consumption and stress increase brain levels of known innate immune signaling molecules. Microglia, the innate immune cells of the brain, and neurons respond to alcohol, signaling through Toll-like receptors (TLRs), high-mobility group box 1 (HMGB1), miRNAs, pro-inflammatory cytokines and their associated receptors involved in signaling between microglia, other glia and neurons. Repeated cycles of alcohol and stress cause a progressive, persistent induction of HMGB1, miRNA and TLR receptors in brain that appear to underlie the progressive and persistent loss of behavioral control, increased impulsivity and anxiety, as well as craving, coupled with increasing ventral striatal responses that promote reward seeking behavior and increase risk of developing alcohol use disorders. Studies employing anti-oxidant, anti-inflammatory, anti-depressant, and innate immune antagonists further link innate immune gene expression to addiction-like behaviors. Innate immune molecules are novel targets for addiction and affective disorders therapies. This article is part of the Special Issue entitled "Alcoholism". Copyright © 2017 Elsevier Ltd. All rights reserved.
Adrenal phaeochromocytoma: correlation of MRI appearances with histology and function

International Nuclear Information System (INIS)

Jacques, Audrey E.T.; Sahdev, Anju; Sandrasagara, Madrika; Rockall, Andrea G.; Reznek, Rodney H.; Goldstein, Rick; Chew, Shern; Berney, Daniel

2008-01-01

The purpose of this study was to describe the range of appearances of adrenal phaeochromocytomas on T2-weighted MRI, correlate appearances with histopathology, and quantify the incidence of the previously described hyperintense appearance. The appearance and MR characteristics of 44 phaeochromocytomas were reviewed retrospectively. T2-weighted appearances were grouped: (1) 'classical', homogeneous, high signal intensity, isointense to CSF; (2) homogeneous, isointense or minimally hyperintense to spleen, hypointense to CSF; (3) heterogeneous, marbled appearance; (4) heterogeneous, multiple high signal intensity pockets. All 44 adrenal phaeochromocytomas were well circumscribed, 1.2-15 cm in maximum diameter, with no visual or quantitative signal loss on chemical shift imaging. On T2-weighted MRI 5/44 (11%) had group 1 appearance; 15/44 (34%) group 2, 7/44 (16%) group 3; and 17/44 (39%) group 4. Homogeneous group 1 and 2 lesions were smaller (mean 4.5 cm) than heterogeneous group 3 and 4 lesions (mean 6.3 cm). Increasing MRI heterogeneity correlated pathologically with increasing amounts of haemorrhage, necrosis and fibrosis. No MRI features were predictive of malignancy. Non-functioning phaeochromocytomas were larger than functioning lesions. No size difference was seen between syndrome and sporadic lesions. In this large series we report a wide range of appearances of adrenal phaeochromocytomas on T2-weighted MRI. The previously described classical hyperintense phaeochromocytoma is relatively uncommon. (orig.)
Signal and noise in financial correlation matrices

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Burda, Zdzisław; Jurkiewicz, Jerzy

2004-12-01

Using Random Matrix Theory one can derive exact relations between the eigenvalue spectrum of the covariance matrix and the eigenvalue spectrum of its estimator (experimentally measured correlation matrix). These relations will be used to analyze a particular case of the correlations in financial series and to show that contrary to earlier claims, correlations can be measured also in the “random” part of the spectrum. Implications for the portfolio optimization are briefly discussed.
Correlation between neurohypophyseal vasopressin content and signal intensity on T{sub 1}-weighted magnetic resonance images. An experimental study of vasopressin depletion model using dehydrated rabbits

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Kurokawa, Hiroaki; Nakano, Yoshihisa; Ikeda, Koshi; Tanaka, Yoshimasa [Kansai Medical Univ., Moriguchi, Osaka (Japan); Fujisawa, Ichiro

1998-06-01

We investigated the correlation between the signal intensity on T{sub 1}-weighted MR images and vasopressin (VP) content in the posterior pituitary lobe. Fourteen rabbits were studied. There were 12 water-deprived rabbits (48, 72, 96, 120, 144 and 168 hours: 2 each) and 2 controls. Sagittal T{sub 1}-weighted SE (spin-echo) MR images were obtained before and after dehydration. The signal intensity ratio of the posterior pituitary lobe to the pons was correlated with the VP content in the posterior lobe as measured by radioimmunoassay. Before water deprivation, high signal intensity in the posterior lobe was demonstrated clearly in all 14 rabbits. After water deprivation, the hyperintense signal gradually decreased and became indistinguishable from anterior lobe in four animals. The mean signal intensity ratio before water deprivation was 1.55{+-}0.12 (mean{+-}SD) and after water deprivation, gradually decreased over time and reached to 1.19 after 168 hours of water deprivation. Pituitary VP content and concentration decreased in parallel with the signal intensity ratio of the posterior pituitary. Significantly correlation was observed between the signal intensity ratio and VP concentration of posterior pituitary (r=0.809, p<0.001) . In conclusion, the results indicate that the signal intensity ratio on T{sub 1}-weighted image may reflect a indicator of pituitary VP content and thus may enable evaluation of disorders of water metabolism. (author)
Highly active microbial phosphoantigen induces rapid yet sustained MEK/Erk- and PI-3K/Akt-mediated signal transduction in anti-tumor human gammadelta T-cells.

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Daniel V Correia

Full Text Available BACKGROUND: The unique responsiveness of Vgamma9Vdelta2 T-cells, the major gammadelta subset of human peripheral blood, to non-peptidic prenyl pyrophosphate antigens constitutes the basis of current gammadelta T-cell-based cancer immunotherapy strategies. However, the molecular mechanisms responsible for phosphoantigen-mediated activation of human gammadelta T-cells remain unclear. In particular, previous reports have described a very slow kinetics of activation of T-cell receptor (TCR-associated signal transduction pathways by isopentenyl pyrophosphate and bromohydrin pyrophosphate, seemingly incompatible with direct binding of these antigens to the Vgamma9Vdelta2 TCR. Here we have studied the most potent natural phosphoantigen yet identified, (E-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP, produced by Eubacteria and Protozoa, and examined its gammadelta T-cell activation and anti-tumor properties. METHODOLOGY/PRINCIPAL FINDINGS: We have performed a comparative study between HMB-PP and the anti-CD3epsilon monoclonal antibody OKT3, used as a reference inducer of bona fide TCR signaling, and followed multiple cellular and molecular gammadelta T-cell activation events. We show that HMB-PP activates MEK/Erk and PI-3K/Akt pathways as rapidly as OKT3, and induces an almost identical transcriptional profile in Vgamma9(+ T-cells. Moreover, MEK/Erk and PI-3K/Akt activities are indispensable for the cellular effects of HMB-PP, including gammadelta T-cell activation, proliferation and anti-tumor cytotoxicity, which are also abolished upon antibody blockade of the Vgamma9(+ TCR Surprisingly, HMB-PP treatment does not induce down-modulation of surface TCR levels, and thereby sustains gammadelta T-cell activation upon re-stimulation. This ultimately translates in potent human gammadelta T-cell anti-tumor function both in vitro and in vivo upon transplantation of human leukemia cells into lymphopenic mice, CONCLUSIONS/SIGNIFICANCE: The development of

Antioxidation, anti-inflammation and anti-apoptosis by paeonol in LPS/d-GalN-induced acute liver failure in mice.

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Gong, Xiaobao; Yang, You; Huang, Ligua; Zhang, Qingyan; Wan, Rong-Zhen; Zhang, Peng; Zhang, Baoshun

2017-05-01

To evaluate the hepatoprotective effects and potential mechanisms of paeonol (Pae) against acute liver failure (ALF) induced by lipopolysaccharide (LPS)/d-galactosamine (d-GalN) in mice, we examined anti-oxidative, anti-inflammatory and anti-apoptotic activities of Pae. We found that Pae pretreatment markedly reduced the activities of alanine transaminase and aspartate transaminase as well as the histopathological changes induced by LPS/d-GalN. Catalase, glutathione and superoxide dismutase activities increased and reactive oxygen species activity decreased after Pae treatment compared with LPS/d-GalN treatment. Pretreatment with Pae also significantly inhibited the expression levels of iNOS, nitric oxide (NO), COX-2 and prostaglandin E 2 (PGE 2 ). In addition, Pae administration prevented the phosphorylated expression of IκB kinase, inhibitor kappa B in the nuclear factor-kappa B (NF-κB) signaling pathway, and suppressed the phosphorylated expression of extracellular signal-regulated kinase (ERK), c-jun-N-terminal kinase and p38 in the MAPK signaling pathway. Pretreatment with Pae also inhibited hepatocyte apoptosis by reducing the expression of caspases 3, 8, 9, and Bax, and increasing Bcl-2. In total, protective effects of Pae against LPS/d-GalN-induced ALF in mice are attributed to its antioxidative effect, inflammatory suppression in NF-κB and MARK signaling pathways, and inhibition of hepatocyte apoptosis inhibition. Therefore, Pae can be a potential therapeutic agent in attenuating LPS/d-GalN-induced ALF in the future. Copyright © 2017. Published by Elsevier B.V.
Membrane Transfer from Mononuclear Cells to Polymorphonuclear Neutrophils Transduces Cell Survival and Activation Signals in the Recipient Cells via Anti-Extrinsic Apoptotic and MAP Kinase Signaling Pathways.

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Li, Ko-Jen; Wu, Cheng-Han; Shen, Chieh-Yu; Kuo, Yu-Min; Yu, Chia-Li; Hsieh, Song-Chou

2016-01-01

The biological significance of membrane transfer (trogocytosis) between polymorphonuclear neutrophils (PMNs) and mononuclear cells (MNCs) remains unclear. We investigated the biological/immunological effects and molecular basis of trogocytosis among various immune cells in healthy individuals and patients with active systemic lupus erythematosus (SLE). By flow cytometry, we determined that molecules in the immunological synapse, including HLA class-I and-II, CD11b and LFA-1, along with CXCR1, are exchanged among autologous PMNs, CD4+ T cells, and U937 cells (monocytes) after cell-cell contact. Small interfering RNA knockdown of the integrin adhesion molecule CD11a in U937 unexpectedly enhanced the level of total membrane transfer from U937 to PMN cells. Functionally, phagocytosis and IL-8 production by PMNs were enhanced after co-culture with T cells. Total membrane transfer from CD4+ T to PMNs delayed PMN apoptosis by suppressing the extrinsic apoptotic molecules, BAX, MYC and caspase 8. This enhancement of activities of PMNs by T cells was found to be mediated via p38- and P44/42-Akt-MAP kinase pathways and inhibited by the actin-polymerization inhibitor, latrunculin B, the clathrin inhibitor, Pitstop-2, and human immunoglobulin G, but not by the caveolin inhibitor, methyl-β-cyclodextrin. In addition, membrane transfer from PMNs enhanced IL-2 production by recipient anti-CD3/anti-CD28 activated MNCs, and this was suppressed by inhibitors of mitogen-activated protein kinase (PD98059) and protein kinase C (Rottlerin). Of clinical significance, decreased total membrane transfer from PMNs to MNCs in patients with active SLE suppressed mononuclear IL-2 production. In conclusion, membrane transfer from MNCs to PMNs, mainly at the immunological synapse, transduces survival and activation signals to enhance PMN functions and is dependent on actin polymerization, clathrin activation, and Fcγ receptors, while membrane transfer from PMNs to MNCs depends on MAP kinase and
Membrane Transfer from Mononuclear Cells to Polymorphonuclear Neutrophils Transduces Cell Survival and Activation Signals in the Recipient Cells via Anti-Extrinsic Apoptotic and MAP Kinase Signaling Pathways.

Directory of Open Access Journals (Sweden)

Ko-Jen Li

Full Text Available The biological significance of membrane transfer (trogocytosis between polymorphonuclear neutrophils (PMNs and mononuclear cells (MNCs remains unclear. We investigated the biological/immunological effects and molecular basis of trogocytosis among various immune cells in healthy individuals and patients with active systemic lupus erythematosus (SLE. By flow cytometry, we determined that molecules in the immunological synapse, including HLA class-I and-II, CD11b and LFA-1, along with CXCR1, are exchanged among autologous PMNs, CD4+ T cells, and U937 cells (monocytes after cell-cell contact. Small interfering RNA knockdown of the integrin adhesion molecule CD11a in U937 unexpectedly enhanced the level of total membrane transfer from U937 to PMN cells. Functionally, phagocytosis and IL-8 production by PMNs were enhanced after co-culture with T cells. Total membrane transfer from CD4+ T to PMNs delayed PMN apoptosis by suppressing the extrinsic apoptotic molecules, BAX, MYC and caspase 8. This enhancement of activities of PMNs by T cells was found to be mediated via p38- and P44/42-Akt-MAP kinase pathways and inhibited by the actin-polymerization inhibitor, latrunculin B, the clathrin inhibitor, Pitstop-2, and human immunoglobulin G, but not by the caveolin inhibitor, methyl-β-cyclodextrin. In addition, membrane transfer from PMNs enhanced IL-2 production by recipient anti-CD3/anti-CD28 activated MNCs, and this was suppressed by inhibitors of mitogen-activated protein kinase (PD98059 and protein kinase C (Rottlerin. Of clinical significance, decreased total membrane transfer from PMNs to MNCs in patients with active SLE suppressed mononuclear IL-2 production. In conclusion, membrane transfer from MNCs to PMNs, mainly at the immunological synapse, transduces survival and activation signals to enhance PMN functions and is dependent on actin polymerization, clathrin activation, and Fcγ receptors, while membrane transfer from PMNs to MNCs depends on
The exchange of correlated pions and kaons in the baryon-baryon interaction

International Nuclear Information System (INIS)

Reuber, A.G.

1995-09-01

The exchange of two correlated pions or kaons provides the main part of the intermediate-range attraction between two baryons. In this work, a dynamical model for correlated two-pion and two-kaon exchange in the baryon-baryon interaction is presented, both in the scalar-isoscalar (σ) and the vector-isovector (ρ) channel. The contribution of correlated ππ and K anti K exchange is derived from the amplitudes for the transition of a baryon-antibaryon state (B anti B') to a ππ or K anti K state in the pseudophysical region by applying dispersion theory and unitarity. For the B anti B'→ππ, K anti K amplitudes a microscopic model is constructed, which is based on the hadron-exchange picture. The Born terms include contributions from baryon-exchange as well as ρ-pole diagrams. The correlations between the two pseudoscalar mesons are taken into account exactly by means of ππ-K anti K amplitudes derived likewise from a meson-exchange model, which is in line with the empirical ππ data. The parameters of the B anti B'→ππ, K anti K model, which are related to each other by the assumption of SU(3) symmetry, are determined by the adjustment to the quasiempirical N anti N→ππ amplitudes in the pseudophysical region. It is found that correlated K anti K exchange being negligible in the NN interaction plays an important role in the σ-channel for baryon-baryon states with non-vanishing strangeness. The strength of correlated ππ plus K anti K exchange in the σ-channel decreases with the strangeness of the baryon-baryon system becoming more negative. Due to the admixture of baryon-exchange processes to the SU(3)-symmetric ρ-pole contributions the results for correlated ππ-exchange in the vector-isovector channel deviate from what is expected in the naive SU(3) picture for genuine ρ-exchange. (orig.)
Correlated cone noise decreases rod signal contributions to the post-receptoral pathways.

Science.gov (United States)

Hathibelagal, Amithavikram R; Feigl, Beatrix; Zele, Andrew J

2018-04-01

This study investigated how invisible extrinsic temporal white noise that correlates with the activity of one of the three [magnocellular (MC), parvocellular (PC), or koniocellular (KC)] post-receptoral pathways alters mesopic rod signaling. A four-primary photostimulator provided independent control of the rod and three cone photoreceptor excitations. The rod contributions to the three post-receptoral pathways were estimated by perceptually matching a 20% contrast rod pulse by independently varying the LMS (MC pathway), +L-M (PC pathway), and S-cone (KC pathway) excitations. We show that extrinsic cone noise caused a predominant decrease in the overall magnitude and ratio of the rod contributions to each pathway. Thus, the relative cone activity in the post-receptoral pathways determines the relative mesopic rod inputs to each pathway.
GC-MS analysis, evaluation of phytochemicals, anti-oxidant, thrombolytic and anti-inflammatory activities of Exacum bicolor

Directory of Open Access Journals (Sweden)

Appaji Mahesh Ashwini

2015-12-01

Full Text Available The aim of the present study was to investigate the GC-MS analysis, phytochemical screening, anti-oxidant, thrombolytic and anti-inflammatory activities of methanol extract of leaves of Exacum bicolor. FTIR analysis confirmed the presence of alcohol, phenols, alkanes, aromatic compounds, aldehyde and ethers. GC-MS analysis revealed the presence of eight phyto-constituents. The total phenol, flavonoid and alkaloid contents were 18.0 ± 0.2 mg/GAE/g, 13.1 ± 0.4 mg QE/g and 108.0 ± 1.2 mg AE/g respectively. The DPPH assay exhibited potent anti-oxidant abilities with IC50 8.8 µg/mL. Significant thrombolytic activity was demonstrated by clot lysis method (45.1 ± 0.8%. The methanol extract showed significant membrane stabilization on human red blood cell with IC50 value of 37.4 µg/mL. There was a significant correlation (R2>0.98 with total phenolic content versus anti-oxidant and anti-inflammatory activity. The above results confirmed that E. bicolor could be a promising anti-oxidant, thrombolytic and anti-inflammatory agent.
Ovarian morphology in polycystic ovary syndrome: estimates from 2D and 3D ultrasound and magnetic resonance imaging and their correlation to anti-Müllerian hormone.

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Nylander, Malin; Frøssing, Signe; Bjerre, Anne H; Chabanova, Elizaveta; Clausen, Helle V; Faber, Jens; Skouby, Sven O

2017-08-01

Background Due to improved ultrasound scanners, new three-dimensional (3D) modalities, and novel Anti-Müllerian hormone (AMH)-assays, the ultrasound criteria for polycystic ovarian morphology are under debate and the appropriate thresholds are often requested. Purpose To quantify the differences in estimates of ovarian volume and antral follicle count (AFC) from two-dimensional (2D) and 3D transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI). Material and Methods A cross-sectional study on 66 overweight women with polycystic ovary syndrome (PCOS) according to Rotterdam criteria. Ovarian volume and AFC were estimated from MRI, 2D TVUS, and 3D TVUS, and serum AMH levels were assessed. Bland-Altman statistics were used for comparison. Results Participants had a median age of 29 years (age range, 19-44 years) with a mean BMI of 32.7 kg/m 2 (SD 4.5). Ovarian volume from 2D TVUS was 1.48 mL (95% confidence interval [CI], 0.94-2.03; P ovarian volume and AFC as compared with 3D TVUS and MRI. Serum AMH correlated best with AFC from 3D TVUS, followed by MRI and 2D TVUS. The advantage of 3D TVUS might be of minor clinical importance when diagnosing PCOS, but useful when the actual AFC are of interest, e.g. in fertility counseling and research.
Anti-Transgender Prejudice: A Structural Equation Model of Associated Constructs

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Tebbe, Esther N.; Moradi, Bonnie

2012-01-01

This study aimed to identify theoretically relevant key correlates of anti-transgender prejudice. Specifically, structural equation modeling was used to test the unique relations of anti-lesbian, gay, and bisexual (LGB) prejudice; traditional gender role attitudes; need for closure; and social dominance orientation with anti-transgender prejudice.…
Spatial organization and correlation properties quantify structural changes on mesoscale of parenchymatous plant tissue

Energy Technology Data Exchange (ETDEWEB)

Valous, N. A.; Delgado, A.; Sun, D.-W., E-mail: dawen.sun@ucd.ie [School of Biosystems Engineering, University College Dublin, National University of Ireland, Belfield, Dublin 4, Dublin (Ireland); Drakakis, K. [Complex and Adaptive Systems Laboratory, University College Dublin, National University of Ireland, Belfield, Dublin 4, Dublin (Ireland)

2014-02-14

The study of plant tissue parenchyma's intercellular air spaces contributes to the understanding of anatomy and physiology. This is challenging due to difficulty in making direct measurements of the pore space and the complex mosaic of parenchymatous tissue. The architectural complexity of pore space has shown that single geometrical measurements are not sufficient for characterization. The inhomogeneity of distribution depends not only on the percentage content of phase, but also on how the phase fills the space. The lacunarity morphometric, as multiscale measure, provides information about the distribution of gaps that correspond to degree of spatial organization in parenchyma. Additionally, modern theories have suggested strategies, where the focus has shifted from the study of averages and histograms to the study of patterns in data fluctuations. Detrended fluctuation analysis provides information on the correlation properties of the parenchyma at different spatial scales. The aim is to quantify (with the aid of the aforementioned metrics), the mesostructural changes—that occur from one cycle of freezing and thawing—in the void phase of pome fruit parenchymatous tissue, acquired with X-ray microcomputed tomography. Complex systems methods provide numerical indices and detailed insights regarding the freezing-induced modifications upon the arrangement of cells and voids. These structural changes have the potential to lead to physiological disorders. The work can further stimulate interest for the analysis of internal plant tissue structures coupled with other physico-chemical processes or phenomena.
Spatial organization and correlation properties quantify structural changes on mesoscale of parenchymatous plant tissue

International Nuclear Information System (INIS)

Valous, N. A.; Delgado, A.; Sun, D.-W.; Drakakis, K.

2014-01-01

The study of plant tissue parenchyma's intercellular air spaces contributes to the understanding of anatomy and physiology. This is challenging due to difficulty in making direct measurements of the pore space and the complex mosaic of parenchymatous tissue. The architectural complexity of pore space has shown that single geometrical measurements are not sufficient for characterization. The inhomogeneity of distribution depends not only on the percentage content of phase, but also on how the phase fills the space. The lacunarity morphometric, as multiscale measure, provides information about the distribution of gaps that correspond to degree of spatial organization in parenchyma. Additionally, modern theories have suggested strategies, where the focus has shifted from the study of averages and histograms to the study of patterns in data fluctuations. Detrended fluctuation analysis provides information on the correlation properties of the parenchyma at different spatial scales. The aim is to quantify (with the aid of the aforementioned metrics), the mesostructural changes—that occur from one cycle of freezing and thawing—in the void phase of pome fruit parenchymatous tissue, acquired with X-ray microcomputed tomography. Complex systems methods provide numerical indices and detailed insights regarding the freezing-induced modifications upon the arrangement of cells and voids. These structural changes have the potential to lead to physiological disorders. The work can further stimulate interest for the analysis of internal plant tissue structures coupled with other physico-chemical processes or phenomena
Intestinal Hedgehog signaling in tumors and inflammation

NARCIS (Netherlands)

Büller, N.V.J.A.

2015-01-01

In this thesis we investigated the role of Hedgehog signaling in tumors and inflammation. By using an inducible Indian Hedgehog (Ihh) knockout mouse we show that Ihh signals via the mesenchyme to the proliferating cells in the crypt to attenuate proliferation. Despite its anti-proliferative role in
Correlation of Respiratory Signals and Electrocardiogram Signals via Empirical Mode Decomposition

KAUST Repository

El Fiky, Ahmed Osama

2011-01-01

research field for signal processing experts to ensure better and clear representation of the different cardiac activities. Given the nonlinear and non-stationary properties of ECGs, it is not a simple task to cancel the undesired noise terms without
Ultra-high-performance liquid chromatography-Time-of-flight high resolution mass spectrometry to quantify acidic drugs in wastewater.

Science.gov (United States)

Becerra-Herrera, Mercedes; Honda, Luis; Richter, Pablo

2015-12-04

A novel analytical approach involving an improved rotating-disk sorptive extraction (RDSE) procedure and ultra-high-performance liquid chromatography (UHPLC) coupled to an ultraspray electrospray ionization source (UESI) and time-of-flight mass spectrometry (TOF/MS), in trap mode, was developed to identify and quantify four non-steroidal anti-inflammatory drugs (NSAIDs) (naproxen, ibuprofen, ketoprofen and diclofenac) and two anti-cholesterol drugs (ACDs) (clofibric acid and gemfibrozil) that are widely used and typically found in water samples. The method reduced the amount of both sample and reagents used and also the time required for the whole analysis, resulting in a reliable and green analytical strategy. The analytical eco-scale was calculated, showing that this methodology is an excellent green analysis, increasing its ecological worth. The detection limits (LOD) and precision (%RSD) were lower than 90ng/L and 10%, respectively. Matrix effects and recoveries were studied using samples from the influent of a wastewater treatment plant (WWTP). All the compounds exhibited suppression of their signals due to matrix effects, and the recoveries were approximately 100%. The applicability and reliability of this methodology were confirmed through the analysis of influent and effluent samples from a WWTP in Santiago, Chile, obtaining concentrations ranging from 1.1 to 20.5μg/L and from 0.5 to 8.6μg/L, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.
Geometric correlations and multifractals

International Nuclear Information System (INIS)

Amritkar, R.E.

1991-07-01

There are many situations where the usual statistical methods are not adequate to characterize correlations in the system. To characterize such situations we introduce mutual correlation dimensions which describe geometric correlations in the system. These dimensions allow us to distinguish between variables which are perfectly correlated with or without a phase lag, variables which are uncorrelated and variables which are partially correlated. We demonstrate the utility of our formalism by considering two examples from dynamical systems. The first example is about the loss of memory in chaotic signals and describes auto-correlations while the second example is about synchronization of chaotic signals and describes cross-correlations. (author). 19 refs, 6 figs
Mycobacterial r32-kDa antigen-specific T-cell responses correlate with successful treatment and a heightened anti-microbial response in human leprosy patients.

Science.gov (United States)

Neela, Venkata Sanjeev Kumar; Devalraju, Kamakshi Prudhula; Pydi, Satya Sudheer; Sunder, Sharada Ramaseri; Adiraju, Kameswara Rao; Singh, Surya Satyanarayana; Anandaraj, M P J S; Valluri, Vijaya Lakshmi

2016-09-01

Immunological characterization of mycobacterial peptides may help not only in the preparation of a vaccine for leprosy but also in developing in vitro T-cell assays that could perhaps be used as an in vitro correlate for treatment outcome. The main goal of this study was to evaluate the use of Mycobacterium bovis recombinant 32-kDa protein (r32-kDa) antigen-stimulated T-cell assay as a surrogate marker for treatment outcome and monitor vitamin D receptor (VDR)-mediated anti-microbial responses during multidrug therapy (MDT) in leprosy. Newly diagnosed tuberculoid and lepromatous leprosy patients were enrolled and followed up during their course of MDT at 6 and 12 months. IFN-γ, IL-10, IL-17 and IL-23 levels in culture supernatants and expression of VDR, TLR2, LL37 and DEFB in r32-kDa-stimulated PBMCs were measured. Controls comprised household contacts (HHCs) and healthy endemic subjects (HCs). Significant differences were observed in the levels of IFN-γ, IL-17, IL-23, VDR and anti-microbial peptides LL37 and DEFB after treatment and when compared with that of HHCs and HCs, respectively. These findings suggest that responses to r32-kDa antigen reflect an improved immunological and anti-microbial response in leprosy patients during therapy, thereby indicating its potential use as an immune correlate in the treatment of leprosy patients. © The Japanese Society for Immunology. 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
A role for Toll-like receptor mediated signals in neutrophils in the pathogenesis of the anti-phospholipid syndrome.

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Gerd Gladigau

Full Text Available The anti-phospholipid syndrome (APS is characterized by recurrent thrombosis and occurrence of anti-phospholipid antibodies (aPL. aPL are necessary, but not sufficient for the clinical manifestations of APS. Growing evidence suggests a role of innate immune cells, in particular polymorphonuclear neutrophils (PMN and Toll-like receptors (TLR to be additionally involved. aPL activate endothelial cells and monocytes through a TLR4-dependent signalling pathway. Whether this is also relevant for PMN in a similar way is currently not known. To address this issue, we used purified PMN from healthy donors and stimulated them in the presence or absence of human monoclonal aPL and the TLR4 agonist LPS monitoring neutrophil effector functions, namely the oxidative burst, phagocytosis, L-Selectin shedding and IL-8 production. aPL alone were only able to induce minor activation of PMN effector functions at high concentrations. However, in the additional presence of LPS the activation threshold was markedly lower indicating a synergistic activation pathway of aPL and TLR in PMN. In summary, our results indicate that PMN effector functions are directly activated by aPL and boosted by the additional presence of microbial products. This highlights a role for PMN as important innate immune effector cells that contribute to the pathophysiology of APS.
Anti-c-MET Nanobody - a new potential drug in multiple myeloma treatment.

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Slørdahl, Tobias Schmidt; Denayer, Tinneke; Moen, Siv Helen; Standal, Therese; Børset, Magne; Ververken, Cedric; Rø, Torstein Baade

2013-11-01

c-MET is the tyrosine kinase receptor of the hepatocyte growth factor (HGF). HGF-c-MET signaling is involved in many human malignancies, including multiple myeloma (MM). Recently, multiple agents have been developed directed to interfere at different levels in HGF-c-MET signaling pathway. Nanobodies are therapeutic proteins based on the smallest functional fragments of heavy-chain-only antibodies. In this study, we wanted to determine the anticancer effect of a novel anti-c-MET Nanobody in MM. We examined the effects of an anti-c-MET Nanobody on thymidine incorporation, migration, adhesion of MM cells, and osteoblastogenesis in vitro. Furthermore, we investigated the effects of the Nanobody on HGF-dependent c-MET signaling by Western blotting. We show that the anti-c-MET Nanobody effectively inhibited thymidine incorporation of ANBL-6 MM cells via inhibition of an HGF autocrine growth loop and thymidine incorporation in INA-6 MM cells induced by exogenous HGF. HGF-induced migration and adhesion of INA-6 were completely and specifically blocked by the Nanobody. Furthermore, the Nanobody abolished the inhibiting effect of HGF on bone morphogenetic protein-2-induced alkaline phosphatase activity and the mineralization of human mesenchymal stem cells. Finally, we show that the Nanobody reduced phosphorylation of tyrosine residues in c-MET, MAPK, and Akt. We also compared the Nanobody with anti-c-MET monoclonal antibodies and revealed the similar or better effect. The anti-c-MET Nanobody inhibited MM cell migration, thymidine incorporation, and adhesion, and blocked the HGF-mediated inhibition of osteoblastogenesis. The anti-c-MET Nanobody might represent a novel therapeutic agent in the treatment of MM and other cancers driven by HGF-c-MET signaling. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Oxidized LDL-induced angiogenesis involves sphingosine 1-phosphate: prevention by anti-S1P antibody.

Science.gov (United States)

Camaré, Caroline; Trayssac, Magali; Garmy-Susini, Barbara; Mucher, Elodie; Sabbadini, Roger; Salvayre, Robert; Negre-Salvayre, Anne

2015-01-01

Neovascularization occurring in atherosclerotic lesions may promote plaque expansion, intraplaque haemorrhage and rupture. Oxidized LDL (oxLDL) are atherogenic, but their angiogenic effect is controversial; both angiogenic and anti-angiogenic effects have been reported. The angiogenic mechanism of oxLDL is partly understood, but the role of the angiogenic sphingolipid, sphingosine 1-phosphate (S1P), in this process is not known. Thus, we investigated whether S1P is involved in the oxLDL-induced angiogenesis and whether an anti-S1P monoclonal antibody can prevent this effect. Angiogenesis was assessed by capillary tube formation by human microvascular endothelial cells (HMEC-1) cultured on Matrigel and in vivo by the Matrigel plug assay in C57BL/6 mice. Human oxLDL exhibited a biphasic angiogenic effect on HMEC-1; low concentrations were angiogenic, higher concentrations were cytotoxic. The angiogenic response to oxLDL was blocked by the sphingosine kinase (SPHK) inhibitor, dimethylsphingosine, by SPHK1-siRNA and by an anti-S1P monoclonal antibody. Moreover, inhibition of oxLDL uptake and subsequent redox signalling by anti-CD36 and anti-LOX-1 receptor antibodies and by N-acetylcysteine, respectively, blocked SPHK1 activation and tube formation. In vivo, in the Matrigel plug assay, low concentrations of human oxLDL or murine oxVLDL also triggered angiogenesis, which was prevented by i.p. injection of the anti-S1P antibody. These data highlight the role of S1P in angiogenesis induced by oxLDL both in HMEC-1 cultured on Matrigel and in vivo in the Matrigel plug model in mice, and demonstrate that the anti-S1P antibody effectively blocks the angiogenic effect of oxLDL. © 2014 The British Pharmacological Society.
Analysis of Maneuvering Targets with Complex Motions by Two-Dimensional Product Modified Lv’s Distribution for Quadratic Frequency Modulation Signals

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Fulong Jing

2017-06-01

Full Text Available For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR and the quadratic chirp rate (QCR are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed. In this paper, by employing a novel multi-scale parametric symmetric self-correlation function (PSSF and modified scaled Fourier transform (mSFT, an effective parameter estimation algorithm is proposed—referred to as the Two-Dimensional product modified Lv’s distribution (2D-PMLVD—for QFM signals. The 2D-PMLVD is simple and can be easily implemented by using fast Fourier transform (FFT and complex multiplication. These measures are analyzed in the paper, including the principle, the cross term, anti-noise performance, and computational complexity. Compared to the other three representative methods, the 2D-PMLVD can achieve better anti-noise performance. The 2D-PMLVD, which is free of searching and has no identifiability problems, is more suitable for multicomponent situations. Through several simulations and analyses, the effectiveness of the proposed estimation algorithm is verified.
Numerical Evaluation of Parameter Correlation in the Hartmann-Tran Line Profile

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Adkins, Erin M.; Reed, Zachary; Hodges, Joseph T.

2017-06-01

The partially correlated quadratic, speed-dependent hard-collision profile (pCqSDHCP), for simplicity referred to as the Hartmann-Tran profile (HTP), has been recommended as a generalized lineshape for high resolution spectroscopy. The HTP parameterizes complex collisional effects such as Dicke narrowing, speed dependent narrowing, and correlations between velocity-changing and dephasing collisions, while also simplifying to simpler profiles that are widely used, such as the Voigt profile. As advanced lineshape profiles are adopted by more researchers, it is important to understand the limitations that data quality has on the ability to retrieve physically meaningful parameters using sophisticated lineshapes that are fit to spectra of finite signal-to-noise ratio. In this work, spectra were simulated using the HITRAN Application Programming Interface (HAPI) across a full range of line parameters. Simulated spectra were evaluated to quantify the precision with which fitted lineshape parameters can be determined at a given signal-to-noise ratio, focusing on the numerical correlation between the retrieved Dicke narrowing frequency and the velocity-changing and dephasing collisions correlation parameter. Tran, H., N. Ngo, and J.-M. Hartmann, Journal of Quantitative Spectroscopy and Radiative Transfer 2013. 129: p. 89-100. Tennyson, et al., Pure Appl. Chem. 2014, 86: p. 1931-1943. Kochanov, R.V., et al., Journal of Quantitative Spectroscopy and Radiative Transfer 2016. 177: p. 15-30. Tran, H., N. Ngo, and J.-M. Hartmann, Journal of Quantitative Spectroscopy and Radiative Transfer 2013. 129: p. 199-203.

Extraction and quantification of "condensed tannins" as a measure of plant anti-herbivore defence? Revisiting an old problem.

Science.gov (United States)

Heil, Martin; Baumann, Birgit; Andary, Claude; Linsenmair, K Eduard; McKey, Doyle

2002-11-01

Contents of phenolic compounds in leaf extracts often serve as a measure of plant anti-herbivore defence. This method suffers from the multifunctionality of phenolics and from problems with their colorimetric quantification. Here we present further evidence for the pertinence of these problems. Contents of condensed tannins (CCT) were spectrophotometrically quantified in leaf extracts of 11 closely related mimosoid species, and Spodoptera littoralis caterpillars were reared on artificial diet containing these extracts. The relationship of CCT with caterpillar growth differed considerably among plant species, since both positive and negative correlations were detected. There was, however, a negative correlation of CCT with fungal spore germination, indicating a role of these compounds in resistance to fungi. Detailed knowledge on the structure and biological function of defensive compounds and on the overall composition of leaves is required to estimate a plant's defensive efficacy against a particular group of enemies.
Ultrasensitive electrochemical immunoassay of staphylococcal enterotoxin B in food using enzyme-nanosilica-doped carbon nanotubes for signal amplification.

Science.gov (United States)

Tang, Dianping; Tang, Juan; Su, Biling; Chen, Guonan

2010-10-27

A new sandwich-type electrochemical immunoassay for ultrasensitive detection of staphylococcal enterotoxin B (SEB) in food was developed using horseradish peroxidase-nanosilica-doped multiwalled carbon nanotubes (HRPSiCNTs) for signal amplification. Rabbit polyclonal anti-SEB antibodies immobilized on the screen-printed carbon electrode (SPCE) and covalently bound to the HRPSiCNTs were used as capture antibodies and detection antibodies, respectively. In the presence of SEB analyte, the sandwich-type immunocomplex could be formed between the immobilized anti-SEB on the SPCE and anti-SEB-labeled HRPSiCNTs, and the carried HRP could catalyze the electrochemical reduction of H2O2 with the help of thionine. The high content of HRP in the HRPSiCNTs could greatly amplify the electrochemical signal. Under optimal conditions, the reduction current increased with the increase of SEB in the sample, and exhibited a dynamic range of 0.05-15 ng/mL with a low detection limit (LOD) of 10 pg/mL SEB (at 3σ). Intra- and interassay coefficients of variation were below 10%. In addition, the assay was evaluated with SEB spiked samples including watermelon juice, soymilk, apple juice, and pork food, receiving excellent correlation with results from commercially available enzyme-linked immunosorbent assay (ELISA).
Using optical fibers with different modes to improve the signal-to-noise ratio of diffuse correlation spectroscopy flow-oximeter measurements

OpenAIRE

He, Lian; Lin, Yu; Shang, Yu; Shelton, Brent J.; Yu, Guoqiang

2013-01-01

The dual-wavelength diffuse correlation spectroscopy (DCS) flow-oximeter is an emerging technique enabling simultaneous measurements of blood flow and blood oxygenation changes in deep tissues. High signal-to-noise ratio (SNR) is crucial when applying DCS technologies in the study of human tissues where the detected signals are usually very weak. In this study, single-mode, few-mode, and multimode fibers are compared to explore the possibility of improving the SNR of DCS flow-oximeter measure...
Walloons as General or Specific Others? A Comparison of anti-Walloon and anti-immigrant Attitudes in Flanders

Directory of Open Access Journals (Sweden)

Bart Meuleman

2017-11-01

Full Text Available This study attempts to shed light on the structure, the prevalence and the determinants of anti-Walloon attitudes in Flanders. For this purpose, we contrast anti-Walloon prejudice with prejudice against a relatively well-understood and archetypical out-group, namely immigrants. Our theoretical approach draws on insights from two paradigms of intergroup relations: the Group-Focused Enmity approach stressing that specific prejudices have a strong common denominator, and the Differentiated Threat model arguing that specific prejudices are contingent on the context of intergroup relations as well as the involved types of threat. To assess the (dissimilarities in anti-Walloon and anti-immigrant prejudice, we use the Flemish dataset of the Belgian National Election Study (BNES 2010. Comparable measurement instruments for both forms of prejudice are analyzed by means of structural equation modeling. Our results reveal a nuanced picture regarding the similarities and differences between anti-Walloon and anti-immigrant attitudes in Flanders. One the one hand, anti-Walloon and anti-immigration attitudes are strongly correlated and rooted in economic threat perceptions. On the other hand, anti-Walloon attitudes are less outspoken in the Flemish population than anti-immigrant attitudes, are less founded on cultural threat perceptions and are more closely linked to feelings of identification with the Flemish in-group.
Anti-HER2 CD4(+) T-helper type 1 response is a novel immune correlate to pathologic response following neoadjuvant therapy in HER2-positive breast cancer.

Science.gov (United States)

Datta, Jashodeep; Berk, Erik; Xu, Shuwen; Fitzpatrick, Elizabeth; Rosemblit, Cinthia; Lowenfeld, Lea; Goodman, Noah; Lewis, David A; Zhang, Paul J; Fisher, Carla; Roses, Robert E; DeMichele, Angela; Czerniecki, Brian J

2015-05-23

A progressive loss of circulating anti-human epidermal growth factor receptor-2/neu (HER2) CD4(+) T-helper type 1 (Th1) immune responses is observed in HER2(pos)-invasive breast cancer (IBC) patients relative to healthy controls. Pathologic complete response (pCR) following neoadjuvant trastuzumab and chemotherapy (T + C) is associated with decreased recurrence and improved prognosis. We examined differences in anti-HER2 Th1 responses between pCR and non-pCR patients to identify modifiable immune correlates to pathologic response following neoadjuvant T + C. Anti-HER2 Th1 responses in 87 HER2(pos)-IBC patients were examined using peripheral blood mononuclear cells pulsed with 6 HER2-derived class II peptides via IFN-γ ELISPOT. Th1 response metrics were anti-HER2 responsivity, repertoire (number of reactive peptides), and cumulative response across 6 peptides (spot-forming cells [SFC]/10(6) cells). Anti-HER2 Th1 responses of non-pCR patients (n = 4) receiving adjuvant HER2-pulsed type 1-polarized dendritic cell (DC1) vaccination were analyzed pre- and post-immunization. Depressed anti-HER2 Th1 responses observed in treatment-naïve HER2(pos)-IBC patients (n = 22) did not improve globally in T + C-treated HER2(pos)-IBC patients (n = 65). Compared with adjuvant T + C receipt, neoadjuvant T + C - utilized in 61.5 % - was associated with higher anti-HER2 Th1 repertoire (p = 0.048). While pCR (n = 16) and non-pCR (n = 24) patients did not differ substantially in demographic/clinical characteristics, pCR patients demonstrated dramatically higher anti-HER2 Th1 responsivity (94 % vs. 33 %, p = 0.0002), repertoire (3.3 vs. 0.3 peptides, p vs. 22.4 SFC/10(6), p non-pCR patients. After controlling for potential confounders, anti-HER2 Th1 responsivity remained independently associated with pathologic response (odds ratio 8.82, p = 0.016). This IFN-γ(+) immune disparity was mediated by anti-HER2 CD4(+)T-bet(+)IFN-γ(+) (i.e., Th1) - not CD4(+)GATA-3(+)IFN-γ(+) (i.e., Th2
Vitamin D as an anti-microbial and anti-inflammatory therapy for Cystic Fibrosis.

Science.gov (United States)

Herscovitch, K; Dauletbaev, N; Lands, Larry C

2014-06-01

Cystic fibrosis (CF) is characterized by chronic infection and inflammation in the airways that lead to progressive lung damage and early death. Current anti-inflammatory therapies are limited by extensive adverse effects or insufficient efficacy. There is a large body of studies indicating beneficial anti-microbial and anti-inflammatory properties of vitamin D. Since most patients with CF present with vitamin D deficiency, and serum vitamin D levels demonstrate a positive correlation with lung function and negative correlation with airway inflammation and infection, correcting vitamin D deficiency may be an attractive therapeutic strategy in CF. The function of vitamin D is intricately tied to its metabolism, which may be impaired at multiple steps in patients with CF, with a potential to limit the efficacy of vitamin D supplementation. It is likely that the aforementioned beneficial properties of vitamin D require supplementation with doses of vitamin D markedly higher than those recommended to maintain proper bone function. This review will illustrate the potential for supplementation with vitamin D or its metabolites to modulate inflammation and improve defence against chronic infection in CF lung, as well as appropriate vitamin D supplementation strategies for improving lung function in CF. Copyright © 2013 Elsevier Ltd. All rights reserved.
Determination of signal intensity affected by Gaussian noise

International Nuclear Information System (INIS)

Blostein, Jeronimo J.; Bennun, Leonardo

1999-01-01

A methodology based on maximum likelihood criteria, to identify and quantify an arbitrary signal affected by Gaussian noise is shown. To use this methodology it is necessary to know the position in the spectrum where the signal of interest should appear, and the shape of the signal when the background is null or unappreciable. (author)
Fixation stability and implication for multifocal electroretinography in patients with neovascular age-related macular degeneration after anti-VEGF treatment

DEFF Research Database (Denmark)

Pedersen, Karen Bjerg; Sjølie, Anne Katrin; Vestergaard, Anders Højslet

2016-01-01

Purpose: To quantify fixation stability in patients with neovascular age-related macular degeneration (nAMD) at baseline, 3 and 6 months after anti-vascular endothelial growth factor (anti-VEGF) treatment and furthermore asses the implications of an unsteady fixation for multifocal...
[A spectrum of neurological diseases with anti-VGKC antibody].

Science.gov (United States)

Arimura, Kimiyoshi; Watanabe, Osamu; Nagado, Tatsui

2007-11-01

Anti-VGKC antibody causing peripheral nerve hyperexcitability is already an established clinical entity. Recently, many patients with non-herpetic limbic encephalitis (NHLE) with anti-VGKC antibody have been reported. The characteristic clinical features are low serum Na+ concentration and good response to immunotherapy. Anti-VGK antibody positive NHLE is relatively frequent among immune-mediated NHLE. It is important to know that this disease is responsive to immunotherapy. Furthermore, anti-VGKC antibody is also positive in some intractable epilepsies. These findings suggest that anti-VGKC is correlated with hyperexcitability in both the peripheral and central nervous system and that the spectrum of anti-VGKC antibody syndrome is now expanding.
Anti-influenza A virus activity of rhein through regulating oxidative stress, TLR4, Akt, MAPK, and NF-κB signal pathways.

Directory of Open Access Journals (Sweden)

Qian-Wen Wang

Full Text Available Rhein, an anthraquinone compound existing in many traditional herbal medicines, has anti-inflammatory, antioxidant, antitumor, antiviral, hepatoprotective, and nephroprotective activities, but its anti-influenza A virus (IAV activity is ambiguous. In the present study, through plaque inhibition assay, time-of-addition assay, antioxidant assay, qRT-PCR, ELISA, and western blotting assays, we investigated the anti-IAV effect and mechanism of action of rhein in vitro and in vivo. The results showed that rhein could significantly inhibit IAV adsorption and replication, decrease IAV-induced oxidative stress, activations of TLR4, Akt, p38, JNK MAPK, and NF-κB pathways, and production of inflammatory cytokines and matrix metalloproteinases in vitro. Oxidant H2O2 and agonists of TLR4, Akt, p38/JNK and IKK/NF-κB could significantly antagonize the inhibitory effects of rhein on IAV-induced cytopathic effect (CPE and IAV replication. Through an in vivo test in mice, we also found that rhein could significantly improve the survival rate, lung index, pulmonary cytokines, and pulmonary histopathological changes. Rhein also significantly decreased pulmonary viral load at a high dose. In conclusion, rhein can inhibit IAV adsorption and replication, and the mechanism of action to inhibit IAV replication may be due to its ability to suppress IAV-induced oxidative stress and activations of TLR4, Akt, p38, JNK MAPK, and NF-κB signal pathways.
A Cyber-Vigilance System for Anti-Terrorist Drives Based on an Unmanned Aerial Vehicular Networking Signal Jammer for Specific Territorial Security

Directory of Open Access Journals (Sweden)

Dhiman Chowdhury

2018-05-01

Full Text Available During sudden anti-terrorist drives conducted by the law enforcement agencies, a localized cyber security system happens to be a special tactic to avert the unprecedented massacre and gruesome fatalities against the residents of that area by disconnecting the affected territory from the rest of the world; so that the militants and their outside accomplices cannot communicate with each other and also the terrorists cannot go through the ongoing apprehensive operation via wireless communications. This paper presents a novel framework of an unmanned aerial vehicular networking signal jammer which is oriented to block incoming and outgoing signals of all frequencies transmitted from a specifically marginalized territory scanned and explored by the aerial vehicle. During such a cyber-vigilance operation, the aerial vehicle is equipped with a transmitter and an auto-tuning band-pass filter module with automatic regulation of center frequencies according to the surrounding networking signals, which are considered to be the suppressing noise parameters. In order to restrict the signal blocking operation within the militant hub, the aerial vehicle with the network terminator is controlled to navigate within a particular boundary of a residential area and its navigation is continuously mapped and stored for effective evacuation process directed to save the innocent stranded people. A very low frequency (VLF metal detector has been designed to trace the explosives and buried landmines inside the exploration arena. An algorithm for 3-D mapping of the metal traces detected by the aerial navigator has been presented in this paper. Signal blocking, metal tracing and stable confined movements have been tested where the testbed is provided with signals of different frequencies along with variation in dimensions of the testing region to evaluate the reliability of the proposed framework.
Low Offset AC Correlator.

Science.gov (United States)

This patent describes a low offset AC correlator avoids DC offset and low frequency noise by frequency operating the correlation signal so that low...noise, low level AC amplification can be substituted for DC amplification. Subsequently, the high level AC signal is demodulated to a DC level. (Author)
The expression of ER, PR in endometrial cancer and analysis of their correlation with ERK signaling pathway.

Science.gov (United States)

Luo, Lan; Xu, Lina; Tang, Liang

2017-12-12

Endometrial carcinoma (EC) is a common malignant tumor in gynecology. Its incidence and development are closely associated with the levels of estrogenic and progesterone hormone. Extracellular signal-regulated kinase (ERK) signaling pathway abnormity is associated with a variety of tumors. This study detected estrogen receptor (ER), progesterone receptor (PR), ERK1, and ERK2 expression in EC and analyzed their correlations. A total of 40 EC patients in our hospital were selected as test group, while another 40 healthy volunteers were enrolled as control group. ER, PR, ERK1, and ERK2 expression in EC tissue, para-carcinoma tissue, and normal endometrial tissue were detected by immunohistochemistry and Western blot. The positive rate of ER, PR, ERK1, and ERK2 in the test group was 50%, 40%, 60%, and 65%, respectively, which were significantly higher than those in the control (PPR, ERK1, and ERK2 protein expressions in EC cell were significantly higher than those in the control (PPR (PPR, which were correlated with higher levels of ERK1 and ERK2, suggesting they might be involved in the pathogenesis of EC.
Anti-jamming Technology in Small Satellite Communication

Science.gov (United States)

Jia, Zixiang

2018-01-01

Small satellite communication has an increasingly important position among the wireless communications due to the advantages of low cost and high technology. However, in view of the case that its relay station stays outside the earth, its uplink may face interference from malicious signal frequently. Here this paper classified enumerates existing interferences, and proposes channel signals as main interference by comparison. Based on a basic digital communication process, then this paper discusses the possible anti - jamming techniques that commonly be realized at all stages in diverse processes, and comes to the conclusion that regarding the spread spectrum technology and antenna anti-jamming technology as fundamental direction of future development. This work provides possible thought for the design of new small satellite communication system with the coexistence of multi - technologies. This basic popular science can be consulted for people interested in small satellite communication.
Mechanisms of anti-D action in the prevention of hemolytic disease of the fetus and newborn.

Science.gov (United States)

Brinc, Davor; Lazarus, Alan H

2009-01-01

Anti-D is routinely and effectively used to prevent hemolytic disease of the fetus and newborn (HDFN) caused by the antibody response to the D antigen on fetal RBCs. Anti-D is a polyclonal IgG product purified from the plasma of D-alloimmunized individuals. The mechanism of anti-D has not been fully elucidated. Antigenic epitopes are not fully masked by anti-D and are available for immune system recognition. However, a correlation has frequently been observed between anti-D-mediated RBC clearance and prevention of the antibody response, suggesting that anti-D may be able to destroy RBCs without triggering the adaptive immune response. Anti-D-opsonized RBCs may also elicit inhibitory FcgammaRIIB signaling in B cells and prevent B cell activation. The ability of antigen-specific IgG to inhibit antibody responses has also been observed in a variety of animal models immunized with a vast array of different antigens, such as sheep RBCs (SRBC). This effect has been referred to as antibody-mediated immune suppression (AMIS). In animal models, IgG inhibits the antibody response, but the T-cell response and memory may still be intact. IgG does not mask all epitopes, and IgG-mediated RBC clearance or FcgammaRIIB-mediated B-cell inhibition do not appear to mediate the AMIS effect. Instead, IgG appears to selectively disrupt B cell priming, although the exact mechanism remains obscure. While the applicability of animal models of AMIS to understanding the true mechanism of anti-D remains uncertain, the models have nevertheless provided us with insights into the possible IgG effects on the immune response.
EVOLUTION OF THE CROSS-CORRELATION AND TIME LAG OF 4U 1735-44 ALONG THE BRANCHES

International Nuclear Information System (INIS)

Lei Yajuan; Zhang Haotong; Zhang Chengmin; Yuan Hailong; Dong Yiqiao; Zhao Yongheng; Zhang Yanxia; Qu Jinlu; Song Liming; Wang Dehua; Yin Hongxing

2013-01-01

We analyze the cross-correlation function between the soft and hard X-rays of atoll source 4U 1735-44 with RXTE data, and find anti-correlated soft and hard time lags of about a hecto-second. In the island state, the observations do not show any obvious correlations, and most observations of the banana branch show a positive correlation. However, anti-correlations are detected in the upper banana branch. These results are different from those of Z-sources (Cyg X-2, GX 5-1), where anti-correlations are detected in the horizontal branch and upper normal branch. In this case, the lag timescales of both this atoll and Z-sources are found to be similar, at a magnitude of several tens to hundreds of seconds. As a comparison, it is noted that anti-correlated lags lasting thousands of seconds have been reported from several black hole candidates in their intermediate states. In addition, for an observation containing four segments that show positive or anti-correlation, we analyze the spectral evolution with the hybrid model. In the observation, the anti-correlation is detected at the highest flux. The fitting results show that the Comptonized component is not the lowest at the highest flux, which suggests that the anti-correlation corresponds to the transition between the soft and hard states. Finally, we compare the corresponding results of atoll source 4U 1735-44 with those observed in Z-sources and black hole candidates, and the possible origins of the anti-correlated time lags are discussed
EVOLUTION OF THE CROSS-CORRELATION AND TIME LAG OF 4U 1735-44 ALONG THE BRANCHES

Energy Technology Data Exchange (ETDEWEB)

Lei Yajuan; Zhang Haotong; Zhang Chengmin; Yuan Hailong; Dong Yiqiao; Zhao Yongheng; Zhang Yanxia [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Qu Jinlu; Song Liming [Particle Astrophysics Center, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wang Dehua [Astronomy Department, Beijing Normal University, Beijing 100875 (China); Yin Hongxing, E-mail: leiyjcwmy@163.com [School of Space Science and Physics, Shandong University, Weihai 264209 (China)

2013-09-15

We analyze the cross-correlation function between the soft and hard X-rays of atoll source 4U 1735-44 with RXTE data, and find anti-correlated soft and hard time lags of about a hecto-second. In the island state, the observations do not show any obvious correlations, and most observations of the banana branch show a positive correlation. However, anti-correlations are detected in the upper banana branch. These results are different from those of Z-sources (Cyg X-2, GX 5-1), where anti-correlations are detected in the horizontal branch and upper normal branch. In this case, the lag timescales of both this atoll and Z-sources are found to be similar, at a magnitude of several tens to hundreds of seconds. As a comparison, it is noted that anti-correlated lags lasting thousands of seconds have been reported from several black hole candidates in their intermediate states. In addition, for an observation containing four segments that show positive or anti-correlation, we analyze the spectral evolution with the hybrid model. In the observation, the anti-correlation is detected at the highest flux. The fitting results show that the Comptonized component is not the lowest at the highest flux, which suggests that the anti-correlation corresponds to the transition between the soft and hard states. Finally, we compare the corresponding results of atoll source 4U 1735-44 with those observed in Z-sources and black hole candidates, and the possible origins of the anti-correlated time lags are discussed.
Quantifying radionuclide signatures from a γ–γ coincidence system

International Nuclear Information System (INIS)

Britton, Richard; Jackson, Mark J.; Davies, Ashley V.

2015-01-01

A method for quantifying gamma coincidence signatures has been developed, and tested in conjunction with a high-efficiency multi-detector system to quickly identify trace amounts of radioactive material. The γ–γ system utilises fully digital electronics and list-mode acquisition to time–stamp each event, allowing coincidence matrices to be easily produced alongside typical ‘singles’ spectra. To quantify the coincidence signatures a software package has been developed to calculate efficiency and cascade summing corrected branching ratios. This utilises ENSDF records as an input, and can be fully automated, allowing the user to quickly and easily create/update a coincidence library that contains all possible γ and conversion electron cascades, associated cascade emission probabilities, and true-coincidence summing corrected γ cascade detection probabilities. It is also fully searchable by energy, nuclide, coincidence pair, γ multiplicity, cascade probability and half-life of the cascade. The probabilities calculated were tested using measurements performed on the γ–γ system, and found to provide accurate results for the nuclides investigated. Given the flexibility of the method, (it only relies on evaluated nuclear data, and accurate efficiency characterisations), the software can now be utilised for a variety of systems, quickly and easily calculating coincidence signature probabilities. - Highlights: • Monte-Carlo based software developed to easily create/update a coincidence signal library for environmental radionuclides. • Coincidence library utilised to accurately quantify gamma coincidence signatures. • All coincidence signature probabilities are corrected for cascade summing, conversion electron emission and pair production. • Key CTBTO relevant radionuclides have been tested to verify the calculated correction factors. • Accurately quantifying coincidence signals during routine analysis will allow dramatically improved detection
Circulating anti-retinal antibodies in response to anti-angiogenic therapy in exudative age-related macular degeneration.

Science.gov (United States)

Kubicka-Trząska, Agnieszka; Wilańska, Joanna; Romanowska-Dixon, Bożena; Sanak, Marek

2014-12-01

To determine changes in anti-retinal antibodies (ARAs) during anti-VEGF therapy in patients with exudative age-related macular degeneration (AMD) and to assess the correlations between ARAs and disease activity. The study comprised 98 patients treated with intravitreal bevacizumab. The ophthalmic examination included best corrected visual acuity (BCVA), slit lamp biomicroscopy, fundoscopy, fluorescein angiography (FA), and optical coherence tomography (OCT). Serum ARAs levels were assessed by indirect immunofluorescence (IIF) on normal monkey retina substrate. These studies were repeated at 4 week intervals within 8 months of a follow-up. The sera of 50 sex- and age-matched healthy subjects were used as controls. At baseline examination, 94 (95.5%) of the 98 patients were positive for ARAs. The ARAs titres were significantly higher (p = 0.0000) than in controls. A positive correlation was found between titres of ARAs and the diameter of choroidal neovascularization (CNV) as measured by FA (p = 0.0000), and central retinal thickness (CRT) assessed by OCT (p = 0.0000). A positive correlation was also found between the diameter of CNV, CRT and the complexity of circulating ARAs. Following treatment all patients demonstrated significant decrease in ARAs levels as well as improvement of BCVA, reduction of subretinal fluid on OCT and decreased leakage on FA. Changes in serum ARAs levels occurred in parallel with clinical outcomes of anti-VEGF therapy. Treatment reduced serum levels of ARAs, with the greatest reduction occurring during the 'loading' phase. This study demonstrated that ARAs may act as a serum biomarker of the efficacy of anti-VEGF therapy. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.
Matching and correlation computations in stereoscopic depth perception.

Science.gov (United States)

Doi, Takahiro; Tanabe, Seiji; Fujita, Ichiro

2011-03-02

A fundamental task of the visual system is to infer depth by using binocular disparity. To encode binocular disparity, the visual cortex performs two distinct computations: one detects matched patterns in paired images (matching computation); the other constructs the cross-correlation between the images (correlation computation). How the two computations are used in stereoscopic perception is unclear. We dissociated their contributions in near/far discrimination by varying the magnitude of the disparity across separate sessions. For small disparity (0.03°), subjects performed at chance level to a binocularly opposite-contrast (anti-correlated) random-dot stereogram (RDS) but improved their performance with the proportion of contrast-matched (correlated) dots. For large disparity (0.48°), the direction of perceived depth reversed with an anti-correlated RDS relative to that for a correlated one. Neither reversed nor normal depth was perceived when anti-correlation was applied to half of the dots. We explain the decision process as a weighted average of the two computations, with the relative weight of the correlation computation increasing with the disparity magnitude. We conclude that matching computation dominates fine depth perception, while both computations contribute to coarser depth perception. Thus, stereoscopic depth perception recruits different computations depending on the disparity magnitude.

Anti-correlated X-ray and Radio Variability in the Transitional Millisecond Pulsar PSR J1023+0038

Science.gov (United States)

Bogdanov, Slavko; Deller, Adam; Miller-Jones, James; Archibald, Anne; Hessels, Jason W. T.; Jaodand, Amruta; Patruno, Alessandro; Bassa, Cees; D'Angelo, Caroline

2018-01-01

The PSR J1023+0038 binary system hosts a 1.69-ms neutron star and a low-mass, main-sequence-like star. The system underwent a transformation from a rotation-powered to a low-luminosity accreting state in 2013 June, in which it has remained since. We present an unprecedented set of strictly simultaneous Chandra X-ray Observatory and Karl G. Jansky Very Large Array observations, which for the first time reveal a highly reproducible, anti-correlated variability pattern. Rapid declines in X-ray flux are always accompanied by a radio brightening with duration that closely matches the low X-ray flux mode intervals. We discuss these findings in the context of accretion and jet outflow physics and their implications for using the radio/X-ray luminosity plane to distinguish low-luminosity candidate black hole binary systems from accreting transitional millisecond pulsars.
Probing two-field open inflation by resonant signals in correlation functions

Energy Technology Data Exchange (ETDEWEB)

Battefeld, Thorsten; Niemeyer, Jens C.; Vlaykov, Dimitar, E-mail: tbattefe@astro.physik.uni-goettingen.de, E-mail: niemeyer@astro.physik.uni-goettingen.de, E-mail: vlaykov@astro.physik.uni-goettingen.de [Institute for Astrophysics, University of Goettingen, Friedrich Hund Platz 1, D-37077 Goettingen (Germany)

2013-05-01

We derive oscillatory signals in correlation functions in two-field open inflation by means of the in-in formalism; such signatures are caused by resonances between oscillations in the tunnelling field and fluctuations in the inflaton during the curvature dominated, intermediate and subsequent inflationary regime. While amplitudes are model-dependent, we find distinct oscillations in the power and bi-spectrum that can act as a direct probe of the curvature dominated phase and thus, indirectly, strengthen the claim of the string landscape if they were observed. We comment on the prospects of detecting these tell-tale signs in current experiments, which is challenging, but not impossible. At the technical level, we pay special attention to the applicability conditions for truncating fluctuations to the light (inflaton) field and derive upper limits on the oscillation amplitude of the heavy field. A violation of these bounds requires a multi-field analysis at the perturbed level.
Feasibility of correlation mapping optical coherence tomography (cmOCT) for anti-spoof sub-surface fingerprinting.

Science.gov (United States)

Zam, Azhar; Dsouza, Roshan; Subhash, Hrebesh M; O'Connell, Marie-Louise; Enfield, Joey; Larin, Kirill; Leahy, Martin J

2013-09-01

We propose the use of correlation mapping optical coherence tomography (cmOCT) to deliver additional biometrics associated with the finger that could complement existing fingerprint technology for law enforcement applications. The current study extends the existing fingerprint paradigm by measuring additional biometrics associated with sub-surface finger tissue such as sub-surface fingerprints, sweat glands, and the pattern of the capillary bed to yield a user-friendly cost effective and anti-spoof multi-mode biometric solution associated with the finger. To our knowledge no other method has been able to capture sub-surface fingerprint, papillary pattern and horizontal vessel pattern in a single scan or to show the correspondence between these patterns in live adult human fingertip. Unlike many current technologies this approach incorporates 'liveness' testing by default. The ultimate output is a biometric module which is difficult to defeat and complements fingerprint scanners that currently are used in border control and law enforcement applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Metric distances derived from cosine similarity and Pearson and Spearman correlations

OpenAIRE

van Dongen, Stijn; Enright, Anton J.

2012-01-01

We investigate two classes of transformations of cosine similarity and Pearson and Spearman correlations into metric distances, utilising the simple tool of metric-preserving functions. The first class puts anti-correlated objects maximally far apart. Previously known transforms fall within this class. The second class collates correlated and anti-correlated objects. An example of such a transformation that yields a metric distance is the sine function when applied to centered data.
The anti-proliferative and anti-angiogenic effect of the methanol extract from brittle star.

Science.gov (United States)

Baharara, Javad; Amini, Elaheh; Mousavi, Marzieh

2015-04-01

Anti-angiogenic therapy is a crucial step in cancer treatment. The discovery of new anti-angiogenic compounds from marine organisms has become an attractive concept in anti-cancer therapy. Because little data correlated to the pro- and anti-angiogenic efficacies of Ophiuroidea, which include brittle star, the current study was designed to explore the anti-angiogenic potential of brittle star methanol extract in vitro and in vivo. The anti-proliferative effect of brittle star extract on A2780cp cells was examined by MTT assays, and transcriptional expression of VEGF and b-FGF was evaluated by RT-PCR. In an in vivo model, 40 fertilized Ross eggs were divided into control and three experimental groups. The experimental groups were incubated with brittle star extract at concentrations of 25, 50 and 100 µg/ml, and photographed by photo-stereomicroscopy. Ultimately, numbers and lengths of vessels were measured by Image J software. Data were analyzed with SPSS software (pstar extract exerted a dose- and time-dependent anti-proliferative effect on A2780cp cancer cells. In addition, VEGF and b-FGF expression decreased with brittle star methanol extract treatment. Macroscopic evaluations revealed significant changes in the second and third experimental group compared to controls (pstar methanol extract in vitro and in vivo confer novel insight into the application of natural marine products in angiogenesis-related pathologies.
Impact of substance P on the correlation of spike train evoked by electro acupuncture

International Nuclear Information System (INIS)

Jin, Chen; Zhang, Xuan; Wang, Jiang; Guo, Yi; Zhao, Xue; Guo, Yong-Ming

2016-01-01

Highlights: • We analyze spike trains induced by EA before and after inhibiting SP in PC6 area. • Inhibiting SP leads to an increase of spiking rate of median nerve. • SP may modulate membrane potential to affect the spiking rate. • SP has an influence on long-range correlation of spike train evoked by EA. • SP play an important role in EA-induced neural spiking and encoding. - Abstract: Substance P (SP) participates in the neural signal transmission evoked by electro-acupuncture (EA). This paper investigates the impact of SP on the correlation of spike train in the median nerve evoked by EA at 'Neiguan' acupoint (PC6). It shows that the spiking rate and interspike interval (ISI) distribution change obviously after inhibiting SP. This variation of spiking activity indicates that SP affects the temporal structure of spike train through modulating the action potential on median nerve filaments. Furtherly, the correlation coefficient and scaling exponent are considered to measure the correlation of spike train. Scaled Windowed Variance (SWV) method is applied to calculate scaling exponent which quantifies the long-range correlation of the neural electrical signals. It is found that the correlation coefficients of ISI increase after inhibiting SP released. In addition, the scaling exponents of neuronal spike train have significant differences between before and after inhibiting SP. These findings demonstrate that SP has an influence on the long-range correlation of spike train. Our results indicate that SP may play an important role in EA-induced neural spiking and encoding.
Magnetic resonance enterography changes after antibody to tumor necrosis factor (anti-TNF) alpha therapy in Crohn’s disease: correlation with SES-CD and clinical-biological markers

International Nuclear Information System (INIS)

Stoppino, Luca Pio; Della Valle, Nicola; Rizzi, Stefania; Cleopazzo, Elsa; Centola, Annarita; Iamele, Donatello; Bristogiannis, Christos; Stoppino, Giuseppe; Vinci, Roberta; Macarini, Luca

2016-01-01

In recent years, the use of MRI in patients with Crohn’s disease (CD) has increased. However, few data are available on how MRI parameters of active disease change during treatment with anti-TNF and whether these changes correspond to symptoms, serum biomarkers, or endoscopic appearance. The aim of this study was to determine the changes over time in MRI parameters during treatment with anti-TNF in patients with CD, and to verify the correlation between MRI score, endoscopic appearance and clinical-biological markers. We performed a prospective single centre study of 27 patients with active CD (18 males and 9 females; median age of 27,4 ys; age range, 19–49). All patients underwent ileocolonoscopy and MRI at baseline and 26 weeks after anti-TNF therapy. Endoscopic severity was graded according to the Simple Endoscopic Score for Crohn’s Disease (SES-CD) and Magnetic Resonance Index of Activity (MaRIA) was calculated. Patients underwent clinical evaluation (CDAI) and the C-reactive protein (CRP) level was measured. The associations between variables were assessed with Pearson’s bivariate correlation analysis. A total of 135 intestinal segments were studied. The median patient age was 27,4 years, 67 % were male and the mean disease duration was 6,1 years. For induction of remission, 18 patients were treated with infliximab and 9 with adalimumab. The mean SES-CD and MaRIA scores significantly changed at week 26 (SES-CD: 14,7 ± 8,9 at baseline vs. 4,4 ± 4,6 at 26 weeks - p < 0.001; MaRIA: 41,1 ± 14,8 at baseline vs. 32,8 ± 11,7 at 26 weeks - p < 0.001). Also the CDAI and serum levels of CRP decreased significantly following treatment (p < 0.001). The overall MaRIA correlated with endoscopic score and with clinical activity (CDAI) both at baseline and at week 26 (p < 0.05). The correlation between overall MaRIA and CRP was significant only at week 26 (p < 0.001). The MaRIA has a good correlation with SES-CD, a high accuracy for prediction of endoscopic
Evolution of Diffusion-Weighted Magnetic Resonance Imaging Signal Abnormality in Sporadic Creutzfeldt-Jakob Disease, With Histopathological Correlation.

Science.gov (United States)

Eisenmenger, Laura; Porter, Marie-Claire; Carswell, Christopher J; Thompson, Andrew; Mead, Simon; Rudge, Peter; Collinge, John; Brandner, Sebastian; Jäger, Hans R; Hyare, Harpreet

2016-01-01

Prion diseases represent the archetype of brain diseases caused by protein misfolding, with the most common subtype being sporadic Creutzfeldt-Jakob disease (sCJD), a rapidly progressive dementia. Diffusion-weighted imaging (DWI) has emerged as the most sensitive magnetic resonance imaging (MRI) sequence for the diagnosis of sCJD, but few studies have assessed the evolution of MRI signal as the disease progresses. To assess the natural history of the MRI signal abnormalities on DWI in sCJD to improve our understanding of the pathogenesis and to investigate the potential of DWI as a biomarker of disease progression, with histopathological correlation. Gray matter involvement on DWI was assessed among 37 patients with sCJD in 26 cortical and 5 subcortical subdivisions per hemisphere using a semiquantitative scoring system of 0 to 2 at baseline and follow-up. A total brain score was calculated as the summed scores in the individual regions. In 7 patients, serial mean diffusivity measurements were obtained. Age at baseline MRI, disease duration, atrophy, codon 129 methionine valine polymorphism, Medical Research Council Rating Scale score, and histopathological findings were documented. The study setting was the National Prion Clinic, London, England. All participants had a probable or definite diagnosis of sCJD and had at least 2 MRI studies performed during the course of their illness. The study dates were October 1, 2008 to April 1, 2012. The dates of our analysis were January 19 to April 20, 2012. Correlation of regional and total brain scores with disease duration. Among the 37 patients with sCJD in this study there was a significant increase in the number of regions demonstrating signal abnormality during the study period, with 59 of 62 regions showing increased signal intensity (SI) at follow-up, most substantially in the caudate and putamen (P disease duration (r = 0.47, P = .003 at baseline and r = 0.35, P = .03 at follow-up), and the left
High prevalence of human anti-bovine IgG antibodies as the major cause of false positive reactions in two-site immunoassays based on monoclonal antibodies

DEFF Research Database (Denmark)

Andersen, Ditte C; Koch, Claus; Jensen, Charlotte H

2004-01-01

were purified by protein G affinity chromatography from culture supernatant containing 10% (v/v) fetal calf serum (FCS). Human anti-animal IgG (bovine, mouse, horse, and swine) antibodies and human anti-bovine serum albumin antibodies were measured using an ELISA design, with direct bridging...... of the solid phase and biotinylated antigens. The false positive reactions were abolished by addition of 1% (v/v) bovine serum to the dilution buffer (DB). Human anti-bovine IgG antibodies (HABIA) were detected in 99 out of 104 sera from blood donors (50 females; 54 males). HABIA levels in male sera (n = 54......) were positively correlated to the false positive signals in the PP14 ELISA (r = 0.923; p detected in the donor sera, but levels and frequencies were lower compared to that of HABIA. Furthermore, HABIA were...
Aberrant Signaling Pathways in Glioma

International Nuclear Information System (INIS)

Nakada, Mitsutoshi; Kita, Daisuke; Watanabe, Takuya; Hayashi, Yutaka; Teng, Lei; Pyko, Ilya V.; Hamada, Jun-Ichiro

2011-01-01

Glioblastoma multiforme (GBM), a WHO grade IV malignant glioma, is the most common and lethal primary brain tumor in adults; few treatments are available. Median survival rates range from 12–15 months. The biological characteristics of this tumor are exemplified by prominent proliferation, active invasiveness, and rich angiogenesis. This is mainly due to highly deregulated signaling pathways in the tumor. Studies of these signaling pathways have greatly increased our understanding of the biology and clinical behavior of GBM. An integrated view of signal transduction will provide a more useful approach in designing novel therapies for this devastating disease. In this review, we summarize the current understanding of GBM signaling pathways with a focus on potential molecular targets for anti-signaling molecular therapies
Diagnostic and prognostic significance of measuring antibodies to alpha-fodrin compared to anti-Ro-52, anti-Ro-60, and anti-La in primary Sjogren's syndrome

DEFF Research Database (Denmark)

Pelck, R.; Manthorpe, R.; Locht, Henning

2008-01-01

OBJECTIVE: To compare sensitivity and specificity of autoantibodies to alpha-fodrin with conventional anti-Ro and anti-La antibodies in patients with primary Sjogren's syndrome (pSS). Data on internal organ manifestations were correlated with presence of autoantibodies. METHODS: We collected...... clinical and laboratory data from 321 patients with pSS (Copenhagen criteria), of which 205 fulfilled the new American-European 2002 consensus criteria. Sera were tested for autoantibodies against alpha-fodrin and recombinant Ro-52, Ro-60, and La proteins. RESULTS: Antibodies to alpha-fodrin were...
The combination of anti-KIR monoclonal antibodies with anti-PD-1/PD-L1 monoclonal antibodies could be a critical breakthrough in overcoming tumor immune escape in NSCLC

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He YY

2018-04-01

increase in expression of inhibitory KIR, and three showed no change. Conclusions: PD-1 expression was correlated with KIR 2D (L1, L3, L4, S4 on tumor cells or TILs. The resistance to anti-PD-1 monoclonal antibody treatment might be related to KIR. The inhibitory HLA/KIR could combine with the PD-1/PD-L1 signaling pathway negatively regulating NSCLC tumor immunity. Keywords: non-small cell lung cancer, immune therapy, HLA/KIR, PD-1/PD-L1, tumor immune escape
CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR QUANTIFYING CYTOMETRIC APPLICATIONS WITH SPECTROSCOPIC INSTRUMENTS

Science.gov (United States)

The confocal laser-scanning microscopy (CLSM) has enormous potential in many biological fields. The goal of a CLSM is to acquire and quantify fluorescence and in some instruments acquire spectral characterization of the emitted signal. The accuracy of these measurements demands t...
Anti-inflammatory and apoptotic effects of the polyphenol curcumin on human fibroblast-like synoviocytes.

Science.gov (United States)

Kloesch, Burkhard; Becker, Tatjana; Dietersdorfer, Elisabeth; Kiener, Hans; Steiner, Guenter

2013-02-01

It has recently been reported that the polyphenol curcumin has pronounced anti-carcinogenic, anti-inflammatory and pro-apoptotic properties. This study investigated possible anti-inflammatory and apoptotic effects of curcumin on the human synovial fibroblast cell line MH7A, and on fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis (RA). MH7A cells and RA-FLS were stimulated either with interleukin (IL)-1β or phorbol 12-myristate 13 acetate (PMA), and treated simultaneously or sequentially with increasing concentrations of curcumin. Release of interleukin (IL)-6 and vascular endothelial growth factor (VEGF)-A was quantified by enzyme-linked immunosorbent assays (ELISAs). In MH7A cells, modulation of the transcription factor nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinases (MAPKs) such as p38 and extracellular-signal regulated kinase (ERK1/2) were analysed by a reporter gene assay and Western blot, respectively. Pro-apoptotic events were monitored by Annexin-V/7-AAD based assay. Cleavage of pro-caspase-3 and -7 was checked with specific antibodies. Curcumin effectively blocked IL-1β and PMA-induced IL-6 expression both in MH7A cells and RA-FLS. VEGF-A expression could only be detected in RA-FLS and was induced by PMA, but not by IL-1β. Furthermore, curcumin inhibited activation of NF-κB and induced dephosphorylation of ERK1/2. Treatment of FLS with high concentrations of curcumin was associated with a decrease in cell viability and induction of apoptosis. The natural compound curcumin represents strong anti-inflammatory properties and induces apoptosis in FLS. This study provides an insight into possible molecular mechanisms of this substance and suggests it as a natural remedy for the treatment of chronic inflammatory diseases like RA. Copyright © 2013 Elsevier B.V. All rights reserved.
Identifying and quantifying main components of physiological noise in functional near infrared spectroscopy on prefrontal cortex

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Evgeniya eKirilina

2013-12-01

Full Text Available Functional Near-Infrared Spectroscopy (fNIRS is a promising method to study functional organization of the prefrontal cortex. However, in order to realize the high potential of fNIRS, effective discrimination between physiological noise originating from forehead skin haemodynamic and cerebral signals is required. Main sources of physiological noise are global and local blood flow regulation processes on multiple time scales. The goal of the present study was to identify the main physiological noise contributions in fNIRS forehead signals and to develop a method for physiological de-noising of fNIRS data. To achieve this goal we combined concurrent time-domain fNIRS and peripheral physiology recordings with wavelet coherence analysis. Depth selectivity was achieved by analyzing moments of photon time-of-flight distributions provided by time-domain fNIRS. Simultaneously, mean arterial blood pressure (MAP, heart rate (HR, and skin blood flow (SBF on the forehead were recorded. Wavelet coherence analysis was employed to quantify the impact of physiological processes on fNIRS signals separately for different time scales. We identified three main processes contributing to physiological noise in fNIRS signals on the forehead. The first process with the period of about 3 s is induced by respiration. The second process is highly correlated with time lagged MAP and HR fluctuations with a period of about 10 s often referred as Mayer waves. The third process is local regulation of the facial skin blood flow time locked to the task-evoked fNIRS signals. All processes affect oxygenated haemoglobin concentration more strongly than that of deoxygenated haemoglobin. Based on these results we developed a set of physiological regressors, which were used for physiological de-noising of fNIRS signals. Our results demonstrate that proposed de-noising method can significantly improve the sensitivity of fNIRS to cerebral signals.
Leptin levels are negatively correlated with 2-arachidonoylglycerol in the cerebrospinal fluid of patients with osteoarthritis.

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James Nicholson

Full Text Available There is compelling evidence in humans that peripheral endocannabinoid signaling is disrupted in obesity. However, little is known about the corresponding central signaling. Here, we have investigated the relationship between gender, leptin, body mass index (BMI and levels of the endocannabinoids anandamide (AEA and 2-arachidonoylglycerol (2-AG in the serum and cerebrospinal fluid (CSF of primarily overweight to obese patients with osteoarthritis.Patients (20 females, 15 males, age range 44-78 years, BMI range 24-42 undergoing total knee arthroplasty for end-stage osteoarthritis were recruited for the study. Endocannabinoids were quantified by liquid chromatography - mass spectrometry. AEA and 2-AG levels in the serum and CSF did not correlate with either age or BMI. However, 2-AG levels in the CSF, but not serum, correlated negatively with CSF leptin levels (Spearman's ρ -0.48, P=0.0076, n=30. No such correlations were observed for AEA and leptin.In the patient sample investigated, there is a negative association between 2-AG and leptin levels in the CSF. This is consistent with pre-clinical studies in animals, demonstrating that leptin controls the levels of hypothalamic endocannabinoids that regulate feeding behavior.
Leptin levels are negatively correlated with 2-arachidonoylglycerol in the cerebrospinal fluid of patients with osteoarthritis.

Science.gov (United States)

Nicholson, James; Azim, Syed; Rebecchi, Mario J; Galbavy, William; Feng, Tian; Reinsel, Ruth; Rizwan, Sabeen; Fowler, Christopher J; Benveniste, Helene; Kaczocha, Martin

2015-01-01

There is compelling evidence in humans that peripheral endocannabinoid signaling is disrupted in obesity. However, little is known about the corresponding central signaling. Here, we have investigated the relationship between gender, leptin, body mass index (BMI) and levels of the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in the serum and cerebrospinal fluid (CSF) of primarily overweight to obese patients with osteoarthritis. Patients (20 females, 15 males, age range 44-78 years, BMI range 24-42) undergoing total knee arthroplasty for end-stage osteoarthritis were recruited for the study. Endocannabinoids were quantified by liquid chromatography - mass spectrometry. AEA and 2-AG levels in the serum and CSF did not correlate with either age or BMI. However, 2-AG levels in the CSF, but not serum, correlated negatively with CSF leptin levels (Spearman's ρ -0.48, P=0.0076, n=30). No such correlations were observed for AEA and leptin. In the patient sample investigated, there is a negative association between 2-AG and leptin levels in the CSF. This is consistent with pre-clinical studies in animals, demonstrating that leptin controls the levels of hypothalamic endocannabinoids that regulate feeding behavior.
Quantum correlation games

International Nuclear Information System (INIS)

Iqbal, Azhar; Weigert, Stefan

2004-01-01

A new approach to play games quantum mechanically is proposed. We consider two players who perform measurements in an EPR-type setting. The payoff relations are defined as functions of correlations, i.e. without reference to classical or quantum mechanics. Classical bi-matrix games are reproduced if the input states are classical and perfectly anti-correlated, that is, for a classical correlation game. However, for a quantum correlation game, with an entangled singlet state as input, qualitatively different solutions are obtained. For example, the Prisoners' Dilemma acquires a Nash equilibrium if both players apply a mixed strategy. It appears to be conceptually impossible to reproduce the properties of quantum correlation games within the framework of classical games
Roles of circulating WNT-signaling proteins and WNT-inhibitors in human adiposity, insulin resistance, insulin secretion, and inflammation.

Science.gov (United States)

Almario, R U; Karakas, S E

2015-02-01

Wingless-type MMTV integration site family member (WNT) signaling and WNT-inhibitors have been implicated in regulation of adipogenesis, insulin resistance, pancreatic function, and inflammation. Our goal was to determine serum proteins involved in WNT signaling (WNT5 and WISP2) and WNT inhibition (SFRP4 and SFRP5) as they relate to obesity, serum adipokines, insulin resistance, insulin secretion, and inflammation in humans. Study population comprised 57 insulin resistant women with polycystic ovary syndrome (PCOS) and 27 reference women. In a cross-sectional study, blood samples were obtained at fasting, during oral, and frequently sampled intravenous glucose tolerance tests. Serum WNT5, WISP2, and SFRP4 concentrations did not differ between PCOS vs. reference women. Serum WNT5 correlated inversely with weight both in PCOS and reference women, and correlated directly with insulin response during oral glucose tolerance test in PCOS women. Serum WISP2 correlated directly with fatty acid binding protein 4. Serum SFRP5 did not differ between obese (n=32) vs. nonobese (n=25) PCOS women, but reference women had lower SFRP5 (pPCOS groups). Serum SFRP5 correlated inversely with IL-1β, TNF-α, cholesterol, and apoprotein B. These findings demonstrated that WNT5 correlated inversely with adiposity and directly with insulin response, and the WNT-inhibitor SFRP5 may be anti-inflammatory. Better understanding of the role of WNT signaling in obesity, insulin resistance, insulin secretion, lipoprotein metabolism, and inflammation is important for prevention and treatment of metabolic syndrome, diabetes and cardiovascular disease. © Georg Thieme Verlag KG Stuttgart · New York.
Studies of the Correlation Between Ionospheric Anomalies and Seismic Activities in the Indian Subcontinent

International Nuclear Information System (INIS)

Sasmal, S.; Chakrabarti, S. K.; Chakrabarti, S.

2010-01-01

in terminator shift takes place up to a couple of days prior to the seismic event. We introduce a new method where we find the effects of the seismic activities on D-layer preparation time (DLPT) and the D-layer disappearance time (DLDT). We identify those days in which DLPT and DLDT exhibit deviations from the average value and we correlate those days with seismic events. Separately, we compute the energy release by the earthquakes and using this, we compute the total energy released locally from distant earthquakes and find correlations of the deviations with them. In this case also we find pre-cursors a few days before the seismic events. In a third approach, we consider the nighttime fluctuation method (differently quantified than the conventional way). We analyzed the nighttime data for the year 2007 to check the correlation between the night time fluctuation of the signal amplitude and the seismic events. Using the statistical method for all the events of the year and for the individual individual earthquakes (Magnitude > 5) we found that the night time signal amplitude becomes very high on three days prior to the seismic events.

Correlation ion mobility spectroscopy

Science.gov (United States)

Pfeifer, Kent B [Los Lunas, NM; Rohde, Steven B [Corrales, NM

2008-08-26

Correlation ion mobility spectrometry (CIMS) uses gating modulation and correlation signal processing to improve IMS instrument performance. Closely spaced ion peaks can be resolved by adding discriminating codes to the gate and matched filtering for the received ion current signal, thereby improving sensitivity and resolution of an ion mobility spectrometer. CIMS can be used to improve the signal-to-noise ratio even for transient chemical samples. CIMS is especially advantageous for small geometry IMS drift tubes that can otherwise have poor resolution due to their small size.
Conception and fabrication of a real time automatic correlator (multi-correlator)

International Nuclear Information System (INIS)

Berthier, D.

1967-10-01

The purpose of this work is to elaborate a specific computer able to display the real.time correlation function of two variables represented by two electrical signals. The various functions to be done are dealt with the best suited technology: delays from numerical method, hybrid multiplication, analog integration. This method proved very versatile so that it has been possible to modify the circuits with more performing components without changing the general conception of the whole system. In particular, the bandwidth, which was originally 125 kHz (1966) is now 1 MHz and will be 5 MHz, January 1968. Many results are obtained from the correlator such as: - determination of pulse responses of linear systems (1. and 2. order filters, oscillating circuits); - extraction of signals from noise; - measurement of time and space correlation in a turbulent plasma; - treatment of electro-biological signals. (author) [fr
Friedelane-type triterpenoids as selective anti-inflammatory agents by regulation of differential signaling pathways in LPS-stimulated macrophages

Energy Technology Data Exchange (ETDEWEB)

Villar-Lorenzo, Andrea, E-mail: avillar@iib.uam.es [Instituto de Investigaciones Biomédicas Alberto Sols (IIBm) (CSIC/UAM), C/ Arturo Duperier 4, 28029 Madrid (Spain); Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), ISCIII, 28029 Madrid (Spain); Ardiles, Alejandro E., E-mail: ale_csic@gmail.com [Instituto Universitario de Bio-Orgánica Antonio González, Departamento de Química Orgánica, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez 2, 38206 La Laguna, Tenerife (Spain); Facultad de Ciencias de la Salud, Universidad Arturo Prat, Casilla 121, Iquique 1110939 (Chile); Arroba, Ana I., E-mail: aarroba@iib.uam.es [Instituto de Investigaciones Biomédicas Alberto Sols (IIBm) (CSIC/UAM), C/ Arturo Duperier 4, 28029 Madrid (Spain); Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), ISCIII, 28029 Madrid (Spain); Hernández-Jiménez, Enrique, E-mail: enheji@gmail.com [Tumor Immunology Laboratory (IdiPAZ), 28029 Madrid (Spain); Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERres), ISCIII, 28029 Madrid (Spain); and others

2016-12-15

A series of 31 pentacyclic triterpenoids isolated from the root barks of Celastrus vulcanicola and Maytenus jelskii were tested for cytotoxicity and inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 18 (C18) and 25 (C25) exhibited significant inhibition of LPS-induced NO release at 50 and 25 μM concentrations, respectively, and decreased mRNAs of pro-inflammatory cytokines. At the molecular level, C18 neither inhibited LPS-mediated phosphorylation of mitogen activated protein kinases (MAPKs) nor nuclear translocation of nuclear factor kappa beta (NFκB). Instead, C18 enhanced and prolonged nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and increased the expression of its target genes including hemeoxigenase 1 (HO1). C25 efficiently inhibited LPS-mediated phosphorylation of JNK, p38 and ERK, without affecting NFκB or Nrf2 signaling pathways. Both compounds reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β (IL1β) proform, reflecting their ability to target the inflammasome. C25 also counteracted LPS effects on iNOS expression and pro-inflammatory cytokines mRNA levels in Bv-2 microglial cells. The anti-inflammatory effect of both compounds was also assessed in human macrophages. Our results suggest that triterpenoids C18 and C25 possess anti-inflammatory effects, which may be therapeutically relevant for diseases linked to inflammation. - Highlights: • Compounds 18 (C18) and 25 (C25) exert anti-inflammatory effects in macrophages. • C18 enhanced nuclear translocation of Nrf2 and increased HO1 expression. • C25 inhibited the phosphorylation of JNK, p38 and ERK, members of the MAPKs family. • C25 reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β. • C18 and C25 may be therapeutic agents for diseases linked to inflammation.
Friedelane-type triterpenoids as selective anti-inflammatory agents by regulation of differential signaling pathways in LPS-stimulated macrophages

International Nuclear Information System (INIS)

Villar-Lorenzo, Andrea; Ardiles, Alejandro E.; Arroba, Ana I.; Hernández-Jiménez, Enrique

2016-01-01

A series of 31 pentacyclic triterpenoids isolated from the root barks of Celastrus vulcanicola and Maytenus jelskii were tested for cytotoxicity and inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 18 (C18) and 25 (C25) exhibited significant inhibition of LPS-induced NO release at 50 and 25 μM concentrations, respectively, and decreased mRNAs of pro-inflammatory cytokines. At the molecular level, C18 neither inhibited LPS-mediated phosphorylation of mitogen activated protein kinases (MAPKs) nor nuclear translocation of nuclear factor kappa beta (NFκB). Instead, C18 enhanced and prolonged nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and increased the expression of its target genes including hemeoxigenase 1 (HO1). C25 efficiently inhibited LPS-mediated phosphorylation of JNK, p38 and ERK, without affecting NFκB or Nrf2 signaling pathways. Both compounds reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β (IL1β) proform, reflecting their ability to target the inflammasome. C25 also counteracted LPS effects on iNOS expression and pro-inflammatory cytokines mRNA levels in Bv-2 microglial cells. The anti-inflammatory effect of both compounds was also assessed in human macrophages. Our results suggest that triterpenoids C18 and C25 possess anti-inflammatory effects, which may be therapeutically relevant for diseases linked to inflammation. - Highlights: • Compounds 18 (C18) and 25 (C25) exert anti-inflammatory effects in macrophages. • C18 enhanced nuclear translocation of Nrf2 and increased HO1 expression. • C25 inhibited the phosphorylation of JNK, p38 and ERK, members of the MAPKs family. • C25 reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β. • C18 and C25 may be therapeutic agents for diseases linked to inflammation.
Anti-Allergic Inflammatory Activity of Interleukin-37 Is Mediated by Novel Signaling Cascades in Human Eosinophils

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Jing Zhu

2018-06-01

Full Text Available IL-1 family regulatory cytokine IL-37b can suppress innate immunity and inflammatory activity in inflammatory diseases. In this study, IL-37b showed remarkable in vitro suppression of inflammatory tumor necrosis factor-α, IL-1β, IL-6, CCL2, and CXCL8 production in the coculture of human primary eosinophils and human bronchial epithelial BEAS-2B cells with the stimulation of bacterial toll-like receptor-2 ligand peptidoglycan, while antagonizing the activation of intracellular nuclear factor-κB, PI3K–Akt, extracellular signal-regulated kinase 1/2, and suppressing the gene transcription of allergic inflammation-related PYCARD, S100A9, and CAMP as demonstrated by flow cytometry, RNA-sequencing, and bioinformatics. Results therefore elucidated the novel anti-inflammation-related molecular mechanisms mediated by IL-37b. Using the house dust mite (HDM-induced humanized asthmatic NOD/SCID mice for preclinical study, intravenous administration of IL-37b restored the normal plasma levels of eosinophil activators CCL11 and IL-5, suppressed the elevated concentrations of Th2 and asthma-related cytokines IL-4, IL-6, and IL-13 and inflammatory IL-17, CCL5, and CCL11 in lung homogenate of asthmatic mice. Histopathological results of lung tissue illustrated that IL-37b could mitigate the enhanced mucus, eosinophil infiltration, thickened airway wall, and goblet cells. Together with similar findings using the ovalbumin- and HDM-induced allergic asthmatic mice further validated the therapeutic potential of IL-37b in allergic asthma. The above results illustrate the novel IL-37-mediated regulation of intracellular inflammation mechanism linking bacterial infection and the activation of human eosinophils and confirm the in vivo anti-inflammatory activity of IL-37b on human allergic asthma.
Anti-troponin I antibodies in renal transplant patients.

Science.gov (United States)

Nunes, José Pedro L; Sampaio, Susana; Cerqueira, Ana; Kaya, Ziya; Oliveira, Nuno Pardal

2015-02-01

To characterize the prevalence and clinical correlates of anti-troponin I antibodies in renal transplant patients. A group of 48 consecutive renal transplant patients under immunosuppressive therapy were studied. Anti-troponin I antibodies were measured and clinical data were retrieved. An anti-troponin I antibody titer renal transplant patients, and are not associated with the presence of clinical heart disease, but are associated with lack of statin therapy. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.
Heavy quark spin correlations in e+e- annihilations

International Nuclear Information System (INIS)

Dalitz, R.H.; Goldstein, G.R.

1988-01-01

It is pointed out that in e + e - annihilation the physical situation is especially favourable for the observation of the strong spin correlation between the D * and anti D * in opposing c- and anti c-jets, predicted by QCD. Some assessment is given of the possibility of observing this in PEP and PETRA data, and with LEP. The possibilities for similar observations for (B * , anti B * ) and (T * , anti T * ) are briefly discussed. (orig.)
Aquatic Eddy Correlation: Quantifying the Artificial Flux Caused by Stirring-Sensitive O

NARCIS (Netherlands)

Holtappels, M.; Noss, C.; Hancke, K.; Cathalot, C.; McGinnis, D.F.; Lorke, A.; Glud, R.N.

2015-01-01

In the last decade, the aquatic eddy correlation (EC) technique has proven to be a powerful approach for non-invasive measurements of oxygen fluxes across the sediment water interface. Fundamental to the EC approach is the correlation of turbulent velocity and oxygen concentration fluctuations
Correlation model to analyze dependent failures for probabilistic risk assessment

International Nuclear Information System (INIS)

Dezfuli, H.

1985-01-01

A methodology is formulated to study the dependent (correlated) failures of various abnormal events in nuclear power plants. This methodology uses correlation analysis is a means for predicting and quantifying the dependent failures. Appropriate techniques are also developed to incorporate the dependent failure in quantifying fault trees and accident sequences. The uncertainty associated with each estimation in all of the developed techniques is addressed and quantified. To identify the relative importance of the degree of dependency (correlation) among events and to incorporate these dependencies in the quantification phase of PRA, the interdependency between a pair of events in expressed with the aid of the correlation coefficient. For the purpose of demonstrating the methodology, the data base used in the Accident Sequence Precursor Study (ASP) was adopted and simulated to obtain distributions for the correlation coefficients. A computer program entitled Correlation Coefficient Generator (CCG) was developed to generate a distribution for each correlation coefficient. The method of bootstrap technique was employed in the CCG computer code to determine confidence limits of the estimated correlation coefficients. A second computer program designated CORRELATE was also developed to obtain probability intervals for both fault trees and accident sequences with statistically correlated failure data
Does anti-malarial drug knowledge predict anti-malarial dispensing practice in drug outlets? A survey of medicine retailers in western Kenya

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Rusk Andria

2012-08-01

Full Text Available Abstract Background Malaria is a major cause of morbidity and mortality in Kenya, where it is the fifth leading cause of death in both children and adults. Effectively managing malaria is dependent upon appropriate treatment. In Kenya, between 17 to 83 percent of febrile individuals first seek treatment for febrile illness over the counter from medicine retailers. Understanding medicine retailer knowledge and behaviour in treating suspected malaria and dispensing anti-malarials is crucial. Methods To investigate medicine retailer knowledge about anti-malarials and their dispensing practices, a survey was conducted of all retail drug outlets that sell anti-malarial medications and serve residents of the Webuye Health and Demographic Surveillance Site in the Bungoma East District of western Kenya. Results Most of the medicine retailers surveyed (65% were able to identify artemether-lumefantrine (AL as the Kenyan Ministry of Health recommended first-line anti-malarial therapy for uncomplicated malaria. Retailers who correctly identified this treatment were also more likely to recommend AL to adult and paediatric customers. However, the proportion of medicine retailers who recommend the correct treatment is disappointingly low. Only 48% would recommend AL to adults, and 37% would recommend it to children. It was discovered that customer demand has an influence on retailer behaviour. Retailer training and education were found to be correlated with anti-malarial drug knowledge, which in turn is correlated with dispensing practices. Medicine retailer behaviour, including patient referral practice and dispensing practices, are also correlated with knowledge of the first-line anti-malarial medication. The Kenya Ministry of Health guidelines were found to influence retailer drug stocking and dispensing behaviours. Conclusion Most medicine retailers could identify the recommended first-line treatment for uncomplicated malaria, but the percentage that could
Below-unitarity-threshold branch cut in the left angle anti q q right angle coefficient of the axial-vector two-current correlation function

International Nuclear Information System (INIS)

Elias, V.; Univ. of Western Ontario, London, ON; Murison, J.L.; Scadron, M.D.; Steele, T.G.

1993-01-01

The dimension-3 quark-condensate component of the flavour-diagonal axial-vector two-current correlation function is evaluated to all orders in the quark mass m qk through use of the quark-condensate component of the nonperturbative fermion propagator. The result obtained is analytic in p 2 except for a branch cut for 0 2 qk ) 2 , corresponding to a branch cut occurring helow the anti qq kinematic threshold. The deep Euclidean region of the longitudinal component of this correlation function is utilized to obtain leading and subleading contributions to the QCD sum-rule relating m qk to . These same sum-rule results are obtained by means of an alternative derivation involving integration over the discontinuity in the correlation function along the branch cut, demonstrating the consistency of the physical-momentum-region branch cut with results obtained via standard means in the deep Euclidean region. (orig.)
Quantitative evaluation of deep and shallow tissue layers' contribution to fNIRS signal using multi-distance optodes and independent component analysis.

Science.gov (United States)

Funane, Tsukasa; Atsumori, Hirokazu; Katura, Takusige; Obata, Akiko N; Sato, Hiroki; Tanikawa, Yukari; Okada, Eiji; Kiguchi, Masashi

2014-01-15

To quantify the effect of absorption changes in the deep tissue (cerebral) and shallow tissue (scalp, skin) layers on functional near-infrared spectroscopy (fNIRS) signals, a method using multi-distance (MD) optodes and independent component analysis (ICA), referred to as the MD-ICA method, is proposed. In previous studies, when the signal from the shallow tissue layer (shallow signal) needs to be eliminated, it was often assumed that the shallow signal had no correlation with the signal from the deep tissue layer (deep signal). In this study, no relationship between the waveforms of deep and shallow signals is assumed, and instead, it is assumed that both signals are linear combinations of multiple signal sources, which allows the inclusion of a "shared component" (such as systemic signals) that is contained in both layers. The method also assumes that the partial optical path length of the shallow layer does not change, whereas that of the deep layer linearly increases along with the increase of the source-detector (S-D) distance. Deep- and shallow-layer contribution ratios of each independent component (IC) are calculated using the dependence of the weight of each IC on the S-D distance. Reconstruction of deep- and shallow-layer signals are performed by the sum of ICs weighted by the deep and shallow contribution ratio. Experimental validation of the principle of this technique was conducted using a dynamic phantom with two absorbing layers. Results showed that our method is effective for evaluating deep-layer contributions even if there are high correlations between deep and shallow signals. Next, we applied the method to fNIRS signals obtained on a human head with 5-, 15-, and 30-mm S-D distances during a verbal fluency task, a verbal working memory task (prefrontal area), a finger tapping task (motor area), and a tetrametric visual checker-board task (occipital area) and then estimated the deep-layer contribution ratio. To evaluate the signal separation
Radiation-hardened fast acquisition/weak signal tracking system and method

Science.gov (United States)

Winternitz, Luke (Inventor); Boegner, Gregory J. (Inventor); Sirotzky, Steve (Inventor)

2009-01-01

A global positioning system (GPS) receiver and method of acquiring and tracking GPS signals comprises an antenna adapted to receive GPS signals; an analog radio frequency device operatively connected to the antenna and adapted to convert the GPS signals from an analog format to a digital format; a plurality of GPS signal tracking correlators operatively connected to the analog RF device; a GPS signal acquisition component operatively connected to the analog RF device and the plurality of GPS signal tracking correlators, wherein the GPS signal acquisition component is adapted to calculate a maximum vector on a databit correlation grid; and a microprocessor operatively connected to the plurality of GPS signal tracking correlators and the GPS signal acquisition component, wherein the microprocessor is adapted to compare the maximum vector with a predetermined correlation threshold to allow the GPS signal to be fully acquired and tracked.
Signals for supersymmetry at HERA

International Nuclear Information System (INIS)

Dreiner, H.; Morawitz, P.

1994-07-01

We consider the baryon parity signals at HERA for the case of the MSSM production mechanisms and the decays via the lepton number violating couplings L i Q anti D. We can probe very small Yukawa couplings λ'> or ∼3.10 -6 , limited only by the decay length of the LSP. We assume the LSP to be the lightest neutralino and study its decays in detail. We present the matrix element squared for the tree-level decay amplitude of a generally mixed neutralino explicitly. We find that the branching fraction to charged leptons strongly depends on the SUSY parameters and can differ significantly from the naively expected 50%. The SUSY mass reaches of the studied processes in the ZEUS detector at HERA were found to be: (m(e, anti ν)+m( anti q)) ≤ 170 GeV, 195 GeV and 205 GeV for the L t Q anti D, L μ Q anti D and L e Q anti D couplings respectively. These are well above existing limits on R-parity violating (R p ) SUSY from previous experiments. We conclude that HERA offers a very promising discovery potential for R p SUSY. (orig.)
Determination of pseudo multi-pulse production rate in GM counters by correlation analysis between signal pulses

International Nuclear Information System (INIS)

Hashimoto, Kengo; Ueda, Taizou

1996-01-01

A technique, based on the correlation analysis of signal pulses in time sequence, is proposed to determine the production rate of the pseudo multi-pulse in Geiger-Mueller (GM) counter. With a multi-channel scaler initiated by a signal pulse, subsequent pulses are recorded in sequence. The production of the multi-pulse increases the counting probability immediately after the initiation. By examining the deviation of the measured probability from the ideal counting probability, the production rate and the average lag time to produce the multi-pulse can be determined. By the use of the present technique, the production rate and the average lag time were obtained for the various GM tubes. These results indicate that the consumption of the quench gas results in a significant increase in the production rate but little variation in the lag time, and that the lag time strongly depends on the tube diameter. (author)
Robust Frame Synchronization for Low Signal-to-Noise Ratio Channels Using Energy-Corrected Differential Correlation

Directory of Open Access Journals (Sweden)

Kim Pansoo

2009-01-01

Full Text Available Recent standards for wireless transmission require reliable synchronization for channels with low signal-to-noise ratio (SNR as well as with a large amount of frequency offset, which necessitates a robust correlator structure for the initial frame synchronization process. In this paper, a new correlation strategy especially targeted for low SNR regions is proposed and its performance is analyzed. By utilizing a modified energy correction term, the proposed method effectively reduces the variance of the decision variable to enhance the detection performance. Most importantly, the method is demonstrated to outperform all previously reported schemes by a significant margin, for SNRs below 5 dB regardless of the existence of the frequency offsets. A variation of the proposed method is also presented for further enhancement over the channels with small frequency errors. The particular application considered for the performance verification is the second generation digital video broadcasting system for satellites (DVB-S2.
Goat anti-rabbit IgG conjugated fluorescent dye-doped silica nanoparticles for human breast carcinoma cell recognition.

Science.gov (United States)

Chen, Min-Yan; Chen, Ze-Zhong; Wu, Ling-Ling; Tang, Hong-Wu; Pang, Dai-Wen

2013-11-12

We report an indirect method for cancer cell recognition using photostable fluorescent silica nanoprobes as biological labels. The dye-doped fluorescent silica nanoparticles were synthesized using the water-in-oil (W/O) reverse microemulsion method. The silica matrix was produced by the controlled hydrolysis of tetraethylorthosilicate (TEOS) in water nanodroplets with the initiation of ammonia (NH3·H2O). Fluorescein isothiocyanate (FITC) or rhodamine B isothiocyanate conjugated with dextran (RBITC-Dextran) was doped in silica nanoparticles (NPs) with a size of 60 ± 5 nm as a fluorescent signal element by covalent bonding and steric hindrance, respectively. The secondary antibody, goat anti-rabbit IgG, was conjugated on the surface of the PEG-terminated modified FITC-doped or RBITC-Dextran-doped silica nanoparticles (PFSiNPs or PBSiNPs) by covalent binding to the PEG linkers using the cyanogen bromide method. The concentrations of goat anti-rabbit IgG covering the nanoprobes were quantified via the Bradford method. In the proof-of-concept experiment, an epithelial cell adhesion molecule (EpCAM) on the human breast cancer SK-Br-3 cell surface was used as the tumor marker, and the nanoparticle functionalized with rabbit anti-EpCAM antibody was employed as the nanoprobe for cancer cell recognition. Compared with fluorescent dye labeled IgG (FITC-IgG and RBITC-IgG), the designed nanoprobes display dramatically increased stability of fluorescence as well as photostability under continuous irradiation.
Autoantibody levels in myositis patients correlate with clinical response during B cell depletion with rituximab.

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Aggarwal, Rohit; Oddis, Chester V; Goudeau, Danielle; Koontz, Diane; Qi, Zengbiao; Reed, Ann M; Ascherman, Dana P; Levesque, Marc C

2016-06-01

To determine the longitudinal trends in serum levels of four myositis-associated autoantibodies: anti-Jo-1, -transcription intermediary factor 1 γ (TIF1-γ), -signal recognition particle (SRP) and -Mi-2, after B cell depletion with rituximab, and to determine the longitudinal association of these autoantibody levels with disease activity as measured by myositis core-set measures (CSMs). Treatment-resistant adult and pediatric myositis subjects (n = 200) received rituximab in the 44-week Rituximab in Myositis Trial. CSMs [muscle enzymes, manual muscle testing (MMT), physician and patient global disease activity, HAQ, and extramuscular disease activity] were evaluated monthly and anti-Jo-1 (n = 28), -TIF1-γ (n = 23), -SRP (n = 25) and -Mi-2 (n = 26) serum levels were measured using validated quantitative ELISAs. Temporal trends and the longitudinal relationship between myositis-associated autoantibodies levels and CSM were estimated using linear mixed models. Following rituximab, anti-Jo-1 levels decreased over time (P myositis subjects decreased after B cell depletion and were correlated with changes in disease activity, whereas anti-SRP levels were only associated with longitudinal muscle enzyme levels. The strong association of anti-Jo-1 levels with clinical outcomes suggests that anti-Jo-1 autoantibodies may be a good biomarker for disease activity. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Nuclear translocation of glutathione S-transferase {pi} is mediated by a non-classical localization signal

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Kawakatsu, Miho [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523 (Japan); Goto, Shinji, E-mail: sgoto@nagasaki-u.ac.jp [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523 (Japan); Yoshida, Takako; Urata, Yoshishige; Li, Tao-Sheng [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523 (Japan)

2011-08-12

Highlights: {yields} Nuclear translocation of GST{pi} is abrogated by the deletion of the last 16 amino acid residues in the carboxy-terminal region, indicating that residues 195-208 of GST{pi} are required for nuclear translocation. {yields} The lack of a contiguous stretch of positively charged amino acid residues within the carboxy-terminal region of GST{pi}, suggests that the nuclear translocation of GST{pi} is mediated by a non-classical nuclear localization signal. {yields} An in vitro transport assay shows that the nuclear translocation of GST{pi} is dependent on cytosolic factors and ATP. -- Abstract: Glutathione S-transferase {pi} (GST{pi}), a member of the GST family of multifunctional enzymes, is highly expressed in human placenta and involved in the protection of cellular components against electrophilic compounds or oxidative stress. We have recently found that GST{pi} is expressed in the cytoplasm, mitochondria, and nucleus in some cancer cells, and that the nuclear expression of GST{pi} appears to correlate with resistance to anti-cancer drugs. Although the mitochondrial targeting signal of GST{pi} was previously identified in the amino-terminal region, the mechanism of nuclear translocation remains completely unknown. In this study, we find that the region of GST{pi}195-208 is critical for nuclear translocation, which is mediated by a novel and non-classical nuclear localization signal. In addition, using an in vitro transport assay, we demonstrate that the nuclear translocation of GST{pi} depends on the cytosolic extract and ATP. Although further experiments are needed to understand in depth the precise mechanism of nuclear translocation of GST{pi}, our results may help to establish more efficient anti-cancer therapy, especially with respect to resistance to anti-cancer drugs.
Correlations between Motor Symptoms across Different Motor Tasks, Quantified via Random Forest Feature Classification in Parkinson’s Disease

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Andreas Kuhner

2017-11-01

Full Text Available BackgroundObjective assessments of Parkinson’s disease (PD patients’ motor state using motion capture techniques are still rarely used in clinical practice, even though they may improve clinical management. One major obstacle relates to the large dimensionality of motor abnormalities in PD. We aimed to extract global motor performance measures covering different everyday motor tasks, as a function of a clinical intervention, i.e., deep brain stimulation (DBS of the subthalamic nucleus.MethodsWe followed a data-driven, machine-learning approach and propose performance measures that employ Random Forests with probability distributions. We applied this method to 14 PD patients with DBS switched-off or -on, and 26 healthy control subjects performing the Timed Up and Go Test (TUG, the Functional Reach Test (FRT, a hand coordination task, walking 10-m straight, and a 90° curve.ResultsFor each motor task, a Random Forest identified a specific set of metrics that optimally separated PD off DBS from healthy subjects. We noted the highest accuracy (94.6% for standing up. This corresponded to a sensitivity of 91.5% to detect a PD patient off DBS, and a specificity of 97.2% representing the rate of correctly identified healthy subjects. We then calculated performance measures based on these sets of metrics and applied those results to characterize symptom severity in different motor tasks. Task-specific symptom severity measures correlated significantly with each other and with the Unified Parkinson’s Disease Rating Scale (UPDRS, part III, correlation of r2 = 0.79. Agreement rates between different measures ranged from 79.8 to 89.3%.ConclusionThe close correlation of PD patients’ various motor abnormalities quantified by different, task-specific severity measures suggests that these abnormalities are only facets of the underlying one-dimensional severity of motor deficits. The identification and characterization of this underlying motor deficit

Artificial Neural Network-Based Early-Age Concrete Strength Monitoring Using Dynamic Response Signals.

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Kim, Junkyeong; Lee, Chaggil; Park, Seunghee

2017-06-07

Concrete is one of the most common materials used to construct a variety of civil infrastructures. However, since concrete might be susceptible to brittle fracture, it is essential to confirm the strength of concrete at the early-age stage of the curing process to prevent unexpected collapse. To address this issue, this study proposes a novel method to estimate the early-age strength of concrete, by integrating an artificial neural network algorithm with a dynamic response measurement of the concrete material. The dynamic response signals of the concrete, including both electromechanical impedances and guided ultrasonic waves, are obtained from an embedded piezoelectric sensor module. The cross-correlation coefficient of the electromechanical impedance signals and the amplitude of the guided ultrasonic wave signals are selected to quantify the variation in dynamic responses according to the strength of the concrete. Furthermore, an artificial neural network algorithm is used to verify a relationship between the variation in dynamic response signals and concrete strength. The results of an experimental study confirm that the proposed approach can be effectively applied to estimate the strength of concrete material from the early-age stage of the curing process.
Anti-CD20 B-cell depletion enhances monocyte reactivity in neuroimmunological disorders

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Hohlfeld Reinhard

2011-10-01

Full Text Available Abstract Background Clinical trials evaluating anti-CD20-mediated B-cell depletion in multiple sclerosis (MS and neuromyelitis optica (NMO generated encouraging results. Our recent studies in the MS model experimental autoimmune encephalomyelitis (EAE attributed clinical benefit to extinction of activated B-cells, but cautioned that depletion of naïve B-cells may be undesirable. We elucidated the regulatory role of un-activated B-cells in EAE and investigated whether anti-CD20 may collaterally diminish regulatory B-cell properties in treatment of neuroimmunological disorders. Methods Myelin oligodendrocyte glycoprotein (MOG peptide-immunized C57Bl/6 mice were depleted of B-cells. Functional consequences for regulatory T-cells (Treg and cytokine production of CD11b+ antigen presenting cells (APC were assessed. Peripheral blood mononuclear cells from 22 patients receiving anti-CD20 and 23 untreated neuroimmunological patients were evaluated for frequencies of B-cells, T-cells and monocytes; monocytic reactivity was determined by TNF-production and expression of signalling lymphocytic activation molecule (SLAM. Results We observed that EAE-exacerbation upon depletion of un-activated B-cells closely correlated with an enhanced production of pro-inflammatory TNF by CD11b+ APC. Paralleling this pre-clinical finding, anti-CD20 treatment of human neuroimmunological disorders increased the relative frequency of monocytes and accentuated pro-inflammatory monocyte function; when reactivated ex vivo, a higher frequency of monocytes from B-cell depleted patients produced TNF and expressed the activation marker SLAM. Conclusions These data suggest that in neuroimmunological disorders, pro-inflammatory APC activity is controlled by a subset of B-cells which is eliminated concomitantly upon anti-CD20 treatment. While this observation does not conflict with the general concept of B-cell depletion in human autoimmunity, it implies that its safety and
Anti-C1q autoantibodies in patients with neuromyelitis optica spectrum disorders.

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Yoshikura, Nobuaki; Kimura, Akio; Hayashi, Yuichi; Inuzuka, Takashi

2017-09-15

We examined anti-complement C1q (C1q) autoantibody levels in serum and cerebrospinal fluid (CSF) samples of patients with neuromyelitis optica spectrum disorders (NMOSD). We analyzed the correlations between anti-C1q autoantibody levels and the clinical and other CSF characteristics of NMOSD. Serum and CSF anti-C1q autoantibody levels increased during the acute phase of NMOSD, reverting to the same levels as controls during remission. CSF anti-C1q autoantibody levels during the acute phase correlated with several markers reflecting disease severity, Expanded Disability Status Scale worsening, spinal cord lesion length in cases with myelitis, CSF protein and interleukin-6 levels, and CSF/serum albumin ratios. Copyright © 2017 Elsevier B.V. All rights reserved.
Auto-correlation in the motor/imaginary human EEG signals: A vision about the FDFA fluctuations.

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Gilney Figueira Zebende

Full Text Available In this paper we analyzed, by the FDFA root mean square fluctuation (rms function, the motor/imaginary human activity produced by a 64-channel electroencephalography (EEG. We utilized the Physionet on-line databank, a publicly available database of human EEG signals, as a standardized reference database for this study. Herein, we report the use of detrended fluctuation analysis (DFA method for EEG analysis. We show that the complex time series of the EEG exhibits characteristic fluctuations depending on the analyzed channel in the scalp-recorded EEG. In order to demonstrate the effectiveness of the proposed technique, we analyzed four distinct channels represented here by F332, F637 (frontal region of the head and P349, P654 (parietal region of the head. We verified that the amplitude of the FDFA rms function is greater for the frontal channels than for the parietal. To tabulate this information in a better way, we define and calculate the difference between FDFA (in log scale for the channels, thus defining a new path for analysis of EEG signals. Finally, related to the studied EEG signals, we obtain the auto-correlation exponent, αDFA by DFA method, that reveals self-affinity at specific time scale. Our results shows that this strategy can be applied to study the human brain activity in EEG processing.
Specific intracellular signal transduction pathways downstream of CSF-1 receptors: their relationship to breast cancer local recurrence and distant relapse in vivo. Potential targets for the development of new, specific anti-breast cancer therapies to improve local control and block metastatic spread?

International Nuclear Information System (INIS)

Kacinski, Barry M.; Sapi, Eva; Flick, Maryann B.; Turner, Bruce; Perrotta, Peter; Maher, M. Grey; Carter, Darryl; Haffy, Bruce

1997-01-01

analogues such as Matrigel. Agents which pharmacologically mimic a TYR-721 →PHE mutation by interfering with the activation of elements of intracellular signal transduction downstream of this tyrosine (PI-3 kinase. pp70-S6kinase) produced similar effects. In contrast, a TYR-809→PHE mutation was without effect on anchorage independent growth or the generation of pulmonary metastases but did completely abolish protease production and rendered the transfected cells unable to invade basement membrane analogues. In a parallel line of research, we employed antibodies which recognized CSF-1R and a novel antibody we prepared to recognize CSF-1R only when phosphorylated on TYR-721 in a study of 80 T1 and T2 breast cancer patients treated with tylectomy and primary radiation therapy. Strong staining with the generic anti-CSF-1R antibody correlated strongly with local relapse (P values <.03) in this patient cohort. Staining with the antibody specific for CSF-1R phosphorylated at TYR-721 was not associated with local relapse but did correlate with the development of distant metastases in this cohort of patients, particularly in axillary node-negative patients (P < .006). Conclusion: In summary, our observations demonstrate that CSF-1R activation and phosphorylation at specific tyrosines regulates invasiveness, anchorage, independent growth and tumorigenicity in vitro and in animal models and correlates with metastatic relapse in vivo. They also suggest that such intracellular signaling pathways--particularly those triggered by the phosphorylation of TYR-721 of CSF-1R--are logical targets for the development of a new class of anti-cancer agents which specifically block breast cancer cell metastatic potential without perturbing other normal cellular metabolic processes
Contribution of correlated noise and selective decoding to choice probability measurements in extrastriate visual cortex.

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Gu, Yong; Angelaki, Dora E; DeAngelis, Gregory C

2014-07-01

Trial by trial covariations between neural activity and perceptual decisions (quantified by choice Probability, CP) have been used to probe the contribution of sensory neurons to perceptual decisions. CPs are thought to be determined by both selective decoding of neural activity and by the structure of correlated noise among neurons, but the respective roles of these factors in creating CPs have been controversial. We used biologically-constrained simulations to explore this issue, taking advantage of a peculiar pattern of CPs exhibited by multisensory neurons in area MSTd that represent self-motion. Although models that relied on correlated noise or selective decoding could both account for the peculiar pattern of CPs, predictions of the selective decoding model were substantially more consistent with various features of the neural and behavioral data. While correlated noise is essential to observe CPs, our findings suggest that selective decoding of neuronal signals also plays important roles.
Correlation between detrended fluctuation analysis and the Lempel-Ziv complexity in nonlinear time series analysis

International Nuclear Information System (INIS)

Tang You-Fu; Liu Shu-Lin; Jiang Rui-Hong; Liu Ying-Hui

2013-01-01

We study the correlation between detrended fluctuation analysis (DFA) and the Lempel-Ziv complexity (LZC) in nonlinear time series analysis in this paper. Typical dynamic systems including a logistic map and a Duffing model are investigated. Moreover, the influence of Gaussian random noise on both the DFA and LZC are analyzed. The results show a high correlation between the DFA and LZC, which can quantify the non-stationarity and the nonlinearity of the time series, respectively. With the enhancement of the random component, the exponent a and the normalized complexity index C show increasing trends. In addition, C is found to be more sensitive to the fluctuation in the nonlinear time series than α. Finally, the correlation between the DFA and LZC is applied to the extraction of vibration signals for a reciprocating compressor gas valve, and an effective fault diagnosis result is obtained
The Essence of Nonclassicality: Non-Vanishing Signal Deficit

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Aravinda, S.; Srikanth, R.

2015-12-01

Nonclassical properties of correlations- like unpredictability, no-cloning and uncertainty- are known to follow from two assumptions: nonlocality and no-signaling. For two-input-two-output correlations, we derive these properties from a single, unified assumption: namely, the excess of the communication cost over the signaling in the correlation. This is relevant to quantum temporal correlations, resources to simulate quantum correlations and extensions of quantum mechanics. We generalize in the context of such correlations the nonclassicality result for nonlocal-nonsignaling correlations (Masanes et al., Phys. Rev. A 73, 012112 (2006)) and the uncertainty bound on nonlocality (Oppenheim and Wehner, Science 330(6007), 1072 (2010)), when the no-signaling condition is relaxed.
Towards rationally redesigning bacterial signaling systems using information encoded in abundant sequence data

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Cheng, Ryan; Morcos, Faruck; Levine, Herbert; Onuchic, Jose

2014-03-01

An important challenge in biology is to distinguish the subset of residues that allow bacterial two-component signaling (TCS) proteins to preferentially interact with their correct TCS partner such that they can bind and transfer signal. Detailed knowledge of this information would allow one to search sequence-space for mutations that can systematically tune the signal transmission between TCS partners as well as re-encode a TCS protein to preferentially transfer signals to a non-partner. Motivated by the notion that this detailed information is found in sequence data, we explore the mutual sequence co-evolution between signaling partners to infer how mutations can positively or negatively alter their interaction. Using Direct Coupling Analysis (DCA) for determining evolutionarily conserved interprotein interactions, we apply a DCA-based metric to quantify mutational changes in the interaction between TCS proteins and demonstrate that it accurately correlates with experimental mutagenesis studies probing the mutational change in the in vitro phosphotransfer. Our methodology serves as a potential framework for the rational design of TCS systems as well as a framework for the system-level study of protein-protein interactions in sequence-rich systems. This research has been supported by the NSF INSPIRE award MCB-1241332 and by the CTBP sponsored by the NSF (Grant PHY-1308264).
Machine learning approaches to evaluate correlation patterns in allosteric signaling: A case study of the PDZ2 domain

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Botlani, Mohsen; Siddiqui, Ahnaf; Varma, Sameer

2018-06-01

Many proteins are regulated by dynamic allostery wherein regulator-induced changes in structure are comparable with thermal fluctuations. Consequently, understanding their mechanisms requires assessment of relationships between and within conformational ensembles of different states. Here we show how machine learning based approaches can be used to simplify this high-dimensional data mining task and also obtain mechanistic insight. In particular, we use these approaches to investigate two fundamental questions in dynamic allostery. First, how do regulators modify inter-site correlations in conformational fluctuations (Cij)? Second, how are regulator-induced shifts in conformational ensembles at two different sites in a protein related to each other? We address these questions in the context of the human protein tyrosine phosphatase 1E's PDZ2 domain, which is a model protein for studying dynamic allostery. We use molecular dynamics to generate conformational ensembles of the PDZ2 domain in both the regulator-bound and regulator-free states. The employed protocol reproduces methyl deuterium order parameters from NMR. Results from unsupervised clustering of Cij combined with flow analyses of weighted graphs of Cij show that regulator binding significantly alters the global signaling network in the protein; however, not by altering the spatial arrangement of strongly interacting amino acid clusters but by modifying the connectivity between clusters. Additionally, we find that regulator-induced shifts in conformational ensembles, which we evaluate by repartitioning ensembles using supervised learning, are, in fact, correlated. This correlation Δij is less extensive compared to Cij, but in contrast to Cij, Δij depends inversely on the distance from the regulator binding site. Assuming that Δij is an indicator of the transduction of the regulatory signal leads to the conclusion that the regulatory signal weakens with distance from the regulatory site. Overall, this
Search for two-photon production of resonances decaying into K anti K and K anti K. pi

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Althoff, M; Braunschweig, W; Kirschfink, F J; Martyn, H U; Rosskamp, R; Siebke, H; Wallraff, W; Eisenmann, J; Fischer, H M; Hartmann, H

1985-11-01

An analysis of the production of Ksub(s)/sup 0/Ksub(s)/sup 0/ and Ksup(+-)Ksub (s)/sup 0/..pi..sup(-+) by two quasi-real photons is presented. The cross section for ..gamma gamma..->K/sup 0/ anti K/sup 0/, which is given for the ..gamma gamma.. invariant mass range from K anti K threshold to 2.5 GeV, is dominated by the f'(1,525) resonance and an enhancement near the K anti K threshold. Upper limits on the product of the two-photon width times the branching ratio into K anti K pairs are given for THETA(1,700), h(2,030), and zeta(2,220). For exclusive two-photon production of Ksup(+-)Ksub(s)/sup 0/..pi..-+ no significant signal was observed. Upper limits are given on the cross section of ..gamma gamma..->K/sup +/ anti K/sup 0/..pi../sup -/ or K/sup -/K/sup 0/..pi../sup +/ between 1.4 and 3.2 GeV and on the product of the ..gamma gamma.. width times the branching ratio into the Kanti K..pi.. final states for the etasub(c)(2,980) and the iota(1,440), yielding GAMMA(..gamma gamma..->iota(1,440)) . BR(iota(1,440)-> K anti K..pi..) < 2.2keV at 95% C.L.
Ultrasound Elasticity Imaging Predicts Therapeutic Outcomes of Patients With Crohn's Disease Treated With Anti-Tumour Necrosis Factor Antibodies.

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Orlando, Stefania; Fraquelli, Mirella; Coletta, Marina; Branchi, Federica; Magarotto, Andrea; Conti, Clara Benedetta; Mazza, Stefano; Conte, Dario; Basilisco, Guido; Caprioli, Flavio

2018-01-05

Ultrasound elasticity imaging is a non-invasive technique developed to evaluate fibrosis. Measuring tissue strain by ultrasound elasticity imaging can reliably detect severe ileal fibrosis in patients with Crohn's disease [CD]. We have hypothesised that a more severe range of fibrosis might influence the therapeutic response to anti-tumour necrosis factor [TNF] treatment. The aim of this study was to assess the ability of ultrasound elasticity imaging to predict the therapeutic outcome for CD patients. Consecutive patients with ileal/ileocolonic CD, starting anti-TNF treatment, were enrolled for the study. These patients underwent bowel ultrasound and ultrasound elasticity imaging at baseline and at 14 and 52 weeks after anti-TNF treatment. Bowel wall stiffness was quantified by calculating the strain ratio between the mesenteric tissue and the bowel wall. Strain ratio ≥ 2 was used to identify severe ileal fibrosis. Transmural healing at 14 and 52 weeks was defined as bowel wall thickness ≤ 3 mm. Thirty patients with CD were enrolled. Five patients underwent surgery for bowel obstruction. The frequency of surgeries was significantly greater in patients with a strain ratio ≥ 2 at baseline [p = 0.003]. A significant reduction of the bowel thickness was observed after 14 and 52 weeks of anti-TNF treatment [p < 0.005]. A significant inverse correlation was observed between the strain ratio values at baseline and the thickness variations following anti-TNF therapy [p = 0.007]; 27% of patients achieved transmural healing at 14 weeks. The baseline strain ratio was significantly lower in patients with transmural healing [p < 0.05]. This study shows that ultrasound elasticity imaging predicts therapeutic outcomes for CD patients treated with anti-TNF. Copyright © 2017 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com
Asymmetric and symmetric meta-correlations in financial markets

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Li Xiaohui; Shen Xiangying; Huang Jiping

2016-01-01

In financial markets, the relation between fluctuations of stock prices and trading behaviors is complex. It is intriguing to quantify this kind of meta-correlation between market fluctuations and the synchronous behaviors. We refine the theoretical index leverage model proposed by Reigneron et al. , to exactly quantify the meta-correlation under various levels of price fluctuations [Reigneron P A, Allez R and Bouchaud J P 2011 Physica A 390 3026]. The characteristics of meta-correlations in times of market losses, are found to be significantly different in Chinese and American financial markets. In addition, unlike the asymmetric results at the daily scale, the correlation behaviors are found to be symmetric at the high-frequency scale. (paper)
The "Fermi hole" and the correlation introduced by the symmetrization or the anti-symmetrization of the wave function.

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Giner, Emmanuel; Tenti, Lorenzo; Angeli, Celestino; Malrieu, Jean-Paul

2016-09-28

The impact of the antisymmetrization is often addressed as a local property of the many-electron wave function, namely that the wave function should vanish when two electrons with parallel spins are in the same position in space. In this paper, we emphasize that this presentation is unduly restrictive: we illustrate the strong non-local character of the antisymmetrization principle, together with the fact that it is a matter of spin symmetry rather than spin parallelism. To this aim, we focus our attention on the simplest representation of various states of two-electron systems, both in atomic (helium atom) and molecular (H 2 and the π system of the ethylene molecule) cases. We discuss the non-local property of the nodal structure of some two-electron wave functions, both using analytical derivations and graphical representations of cuttings of the nodal hypersurfaces. The attention is then focussed on the impact of the antisymmetrization on the maxima of the two-body density, and we show that it introduces strong correlation effects (radial and/or angular) with a non-local character. These correlation effects are analyzed in terms of inflation and depletion zones, which are easily identifiable, thanks to the nodes of the orbitals composing the wave function. Also, we show that the correlation effects induced by the antisymmetrization occur also for anti-parallel spins since all M s components of a given spin state have the same N-body densities. Finally, we illustrate that these correlation effects occur also for the singlet states, but they have strictly opposite impacts: the inflation zones in the triplet become depletion zones in the singlet and vice versa.
Correlation of histological examination of meniscus with MR images; Focused on high signal intensity of the meniscus not caused by definite meniscal tear and impact on MR diagnosis of tears

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Li, Chun Ai; Kim, Min Ki; Kim, In Hwan; Lee, Ju Hong; Jang, Kyu Yun; Lee, Sang Yong [Chonbuk National University Hospital, Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

2013-12-15

To document the causes of high signal intensity of the meniscus which is not caused by definite meniscal tears on MR imaging, through correlation with histological examination. For the correlation between the MR image and histology, we obtained prospectively 31 meniscal specimens from 21 patients. Proton density-weighted turbo spin-echo MR images were used. Minimal tear, thinning of the lamellar layer, degeneration of the central layer, and radial tie fibers were detected upon histological examination, and were correlated with the corresponding MR images. Minimal tear of the lamellar layer was seen in 60 zones out of 100 slides. On MR images, 29 (48.3%) of these 60 zones had high signal intensity. Thinning of the lamellar layer was seen in 24 zones, with 7 (29.2%) having high signal intensity. 57 central zones showed degenerative change in the central layer and high signal intensity on all corresponding MR images. Radial tie fibers in the central layer appeared as high signal intensity areas. Minimal tear and thinning of the lamellar layer, degeneration and radial tie fibers of the central layer of the meniscus cause high signal intensity on MR images.
MOTION ARTIFACT REDUCTION IN FUNCTIONAL NEAR INFRARED SPECTROSCOPY SIGNALS BY AUTOREGRESSIVE MOVING AVERAGE MODELING BASED KALMAN FILTERING

Directory of Open Access Journals (Sweden)

MEHDI AMIAN

2013-10-01

Full Text Available Functional near infrared spectroscopy (fNIRS is a technique that is used for noninvasive measurement of the oxyhemoglobin (HbO2 and deoxyhemoglobin (HHb concentrations in the brain tissue. Since the ratio of the concentration of these two agents is correlated with the neuronal activity, fNIRS can be used for the monitoring and quantifying the cortical activity. The portability of fNIRS makes it a good candidate for studies involving subject's movement. The fNIRS measurements, however, are sensitive to artifacts generated by subject's head motion. This makes fNIRS signals less effective in such applications. In this paper, the autoregressive moving average (ARMA modeling of the fNIRS signal is proposed for state-space representation of the signal which is then fed to the Kalman filter for estimating the motionless signal from motion corrupted signal. Results are compared to the autoregressive model (AR based approach, which has been done previously, and show that the ARMA models outperform AR models. We attribute it to the richer structure, containing more terms indeed, of ARMA than AR. We show that the signal to noise ratio (SNR is about 2 dB higher for ARMA based method.
Fermi-Dirac Correlations in $\\Lambda$ Pairs in Hadronic Z Decays

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Barate, R; Ghez, P; Goy, C; Lees, J P; Martin, F; Merle, E; Minard, M N; Pietrzyk, B; Alemany, R; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Pacheco, A; Riu, I; Ruiz, H; Colaleo, A; Creanza, D; De Palma, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Boix, G; Buchmüller, O L; Cattaneo, M; Cerutti, F; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Greening, T C; Halley, A W; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Leroy, O; Mato, P; Minten, Adolf G; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tournefier, E; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Rougé, A; Rumpf, M; Swynghedauw, M; Verderi, M; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Teixeira-Dias, P; Thompson, A S; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Marinelli, N; Sciabà, A; Sedgbeer, J K; Thomson, E; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Buck, P G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Robertson, N A; Williams, M I; Giehl, I; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Wachsmuth, H W; Zeitnitz, C; Aubert, Jean-Jacques; Bonissent, A; Carr, J; Coyle, P; Payre, P; Rousseau, D; Aleppo, M; Antonelli, M; Ragusa, F; Büscher, V; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Le Diberder, F R; Lefrançois, J; Lutz, A M; Schune, M H; Veillet, J J; Videau, I; Zerwas, D; Bagliesi, G; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Ferrante, I; Foà, L; Giassi, A; Gregorio, A; Ligabue, F; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sguazzoni, G; Tenchini, Roberto; Venturi, A; Verdini, P G; Blair, G A; Cowan, G D; Green, M G; Medcalf, T; Strong, J A; Botterill, David R; Clifft, R W; Edgecock, T R; Norton, P R; Thompson, J C; Tomalin, I R; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Grupen, Claus; Hess, J; Misiejuk, A; Prange, G; Sieler, U; Giannini, G; Gobbo, B; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Von Wimmersperg-Töller, J H; Wu Sau Lan; Wu, X; Zobernig, G

2000-01-01

Two-particle correlations of Lambda Lambda and Anti-Lambda Anti-Lambda pairshave been studied in multihadronic Z decays recorded with the ALEPH detector at LEP in the years from 1992 to 1995. The correlations were measured as a function of the four-momentum difference Q of the pair. A depletion of events is observed in the region Q 2 GeV the fraction of pairs with spin one is consistent with the value of 0.75 expected for a statistical spin mixture, whilst for Q < 2 GeV this fraction is found to be lower. For Lambda Anti-Lambda pairs, where no Fermi-Dirac correlations are expected, the spin one fraction is measured to be consistent with 0.75 over the entire analysed Q range.
Characterization of organic materials by LIBS for exploration of correlation between molecular and elemental LIBS signals

Directory of Open Access Journals (Sweden)

Shikha Rai

2011-12-01

Full Text Available The present study is performed for the preparation of a database by accumulating LIBS spectra of 4-nitroaniline and 4-nitrotoluene in air and argon. Changes in the behavior of the molecular bands of the C2 Swan system and CN violet system as well as of atomic lines of C, H and N in the LIBS signal are appreciable in argon. In order to explore the correlation between observed LIBS signal and molecular composition of these materials, normalized intensities of the emission lines have been estimated for each compound. It has been found that the relative rates of increase/decrease in the normalized intensities for all sets are higher for 4-nitrotoluene in argon. The cause of the higher rate for 4-nitrotoluene might be due to the possession of a distinctive functional group. The ultimate goal behind the whole study is to use this data-base as input for the discrimination of energetic materials.
Evaluation of a modified IRMA for anti-D quantitation, using 3H protein A

International Nuclear Information System (INIS)

Dumasia, A.; Gupte, S.

1993-01-01

A modified immunoradiometric assay (IRMA) using tritiated ( 3 H) protein A was developed to estimate anti-D concentration. The main advantages of the assay were longer shelf life of the labelled reagent (more than two years); minimum radiation hazard and; low non specific binding. Levels of anti-D were estimated in 23 Rh (D) immunized women. A good correlation of anti-D concentration (μg/ml) with Rh antibody titre was observed (r=+ 0.89, P 3 H protein A IRMA correlated well with the severity of Rh-HDN. This assay could quantitate anti-D in sera having exclusively IgG 3 subtype. (author). 20 refs., 2 figs., 2 tabs
Broad, Intense Anti-Human Immunodeficiency Virus (HIV) Ex Vivo CD8+ Responses in HIV Type 1-Infected Patients: Comparison with Anti-Epstein-Barr Virus Responses and Changes during Antiretroviral Therapy

Science.gov (United States)

Dalod, Marc; Dupuis, Marion; Deschemin, Jean-Christophe; Sicard, Didier; Salmon, Dominique; Delfraissy, Jean-Francois; Venet, Alain; Sinet, Martine; Guillet, Jean-Gerard

1999-01-01

The ex vivo antiviral CD8+ repertoires of 34 human immunodeficiency virus (HIV)-seropositive patients with various CD4+ T-cell counts and virus loads were analyzed by gamma interferon enzyme-linked immunospot assay, using peptides derived from HIV type 1 and Epstein-Barr virus (EBV). Most patients recognized many HIV peptides, with markedly high frequencies, in association with all the HLA class I molecules tested. We found no correlation between the intensity of anti-HIV CD8+ responses and the CD4+ counts or virus load. In contrast, the polyclonality of anti-HIV CD8+ responses was positively correlated with the CD4+ counts. The anti-EBV responses were significantly less intense than the anti-HIV responses and were positively correlated with the CD4+ counts. Longitudinal follow-up of several patients revealed the remarkable stability of the anti-HIV and anti-EBV CD8+ responses in two patients with stable CD4+ counts, while both antiviral responses decreased in two patients with obvious progression toward disease. Last, highly active antiretroviral therapy induced marked decreases in the number of anti-HIV CD8+ T cells, while the anti-EBV responses increased. These findings emphasize the magnitude of the ex vivo HIV-specific CD8+ responses at all stages of HIV infection and suggest that the CD8+ hyperlymphocytosis commonly observed in HIV infection is driven mainly by virus replication, through intense, continuous activation of HIV-specific CD8+ T cells until ultimate progression toward disease. Nevertheless, highly polyclonal anti-HIV CD8+ responses may be associated with a better clinical status. Our data also suggest that a decrease of anti-EBV CD8+ responses may occur with depletion of CD4+ T cells, but this could be restored by highly active antiretroviral treatment. PMID:10438796

On-Chip Correlator for Passive Wireless SAW Multisensor Systems

Directory of Open Access Journals (Sweden)

Liqiang Xie

2016-01-01

Full Text Available For decoding the asynchronous superposition of response signals from different sensors, it is a challenge to achieve correlation in a code division multiplexing (CDM based passive wireless surface acoustic wave (SAW multisensor system. Therefore, an on-chip correlator scheme is developed in this paper. In contrast to conventional CDM-based systems, this novel scheme enables the correlations to be operated at the SAW sensors, instead of the reader. Thus, the response signals arriving at the reader are the result of cross-correlation on the chips. It is then easy for the reader to distinguish the sensor that is matched with the interrogating signal. The operation principle, signal analysis, and simulation of the novel scheme are described in the paper. The simulation results show the response signals from the correlations of the sensors. A clear spike pulse is presented in the response signals, when a sensor code is matched with the interrogating code. Simulations verify the feasibility of the on-chip correlator concept.
Quantifying Matter

CERN Document Server

Angelo, Joseph A

2011-01-01

Quantifying Matter explains how scientists learned to measure matter and quantify some of its most fascinating and useful properties. It presents many of the most important intellectual achievements and technical developments that led to the scientific interpretation of substance. Complete with full-color photographs, this exciting new volume describes the basic characteristics and properties of matter. Chapters include:. -Exploring the Nature of Matter. -The Origin of Matter. -The Search for Substance. -Quantifying Matter During the Scientific Revolution. -Understanding Matter's Electromagnet
Detection of a dynamic topography signal in last interglacial sea-level records.

Science.gov (United States)

Austermann, Jacqueline; Mitrovica, Jerry X; Huybers, Peter; Rovere, Alessio

2017-07-01

Estimating minimum ice volume during the last interglacial based on local sea-level indicators requires that these indicators are corrected for processes that alter local sea level relative to the global average. Although glacial isostatic adjustment is generally accounted for, global scale dynamic changes in topography driven by convective mantle flow are generally not considered. We use numerical models of mantle flow to quantify vertical deflections caused by dynamic topography and compare predictions at passive margins to a globally distributed set of last interglacial sea-level markers. The deflections predicted as a result of dynamic topography are significantly correlated with marker elevations (>95% probability) and are consistent with construction and preservation attributes across marker types. We conclude that a dynamic topography signal is present in the elevation of last interglacial sea-level records and that the signal must be accounted for in any effort to determine peak global mean sea level during the last interglacial to within an accuracy of several meters.
Anomalous Quantum Correlations of Squeezed Light

Science.gov (United States)

Kühn, B.; Vogel, W.; Mraz, M.; Köhnke, S.; Hage, B.

2017-04-01

Three different noise moments of field strength, intensity, and their correlations are simultaneously measured. For this purpose a homodyne cross-correlation measurement [1] is implemented by superimposing the signal field and a weak local oscillator on an unbalanced beam splitter. The relevant information is obtained via the intensity noise correlation of the output modes. Detection details like quantum efficiencies or uncorrelated dark noise are meaningless for our technique. Yet unknown insight in the quantumness of a squeezed signal field is retrieved from the anomalous moment, correlating field strength with intensity noise. A classical inequality including this moment is violated for almost all signal phases. Precognition on quantum theory is superfluous, as our analysis is solely based on classical physics.
Detection of anti-lactoferrin antibodies and anti-myeloperoxidase antibodies in autoimmune hepatitis: a retrospective study.

Science.gov (United States)

Tan, Liming; Zhang, Yuhong; Peng, Weihua; Chen, Juanjuan; Li, Hua; Ming, Feng

2014-01-01

Anti-lactoferrin antibodies (ALA) and anti-myeloperoxidase antibodies (AMPA) are specific serological markers for autoimmune hepatitis (AIH). The project aimed to detect ALA and AMPA and explore their clinical significances in AIH patients. 59 AIH patients, 217 non AIH patients, and 50 healthy controls were enrolled in this study. ALA and AMPA were detected by ELISA. Antineutropil cytoplasmic antibodies (ANCA) and anti-smooth muscle antibodies (ASMA) were examined by indirect immunofluorescence. Antimitochondrial antibody M2 subtype (AMA-M2), anti-liver kidney microsomal antibody Type 1 (LKM1), anti-liver cytosol antibody Type 1 (LC1), and anti-soluble liver antigen/liver-pancreas antibodies (SLA/LP) were tested by immunoblot. The positivity for ALA was 18.6% in AIH group, only one patient in non-AIH group was positive for ALA; the positivity for AMPA was 59.3% in AIH group, with significant differences (P < 0.01) compared with other groups. The specificities for ALA and AMPA were 99.63% and 97.75%; the sensitivities were 18.64% and 59.32%; and the accuracy rates were 84.97% and 90.80%, respectively. A certain correlation was observed between ALA and SLA/LP, AMPA and ANCA, ASMA in AIH group. ALA and AMPA were associated with AIH, and had high clinical diagnostic value. Co-detection with other relative autoantibodies could play an important role in differential diagnosis of AIH.
Real-time algorithm for the measurement of liquid metal coolant flow velocity with correlated thermal signals

International Nuclear Information System (INIS)

Moazzeni, Taleb; Jiang, Yingtao; Ma, Jian; Li, Ning

2009-01-01

One flow meter was developed especially for the environment of high irradiation, pressure, and temperature. The transit time of natural random temperature fluctuation in process, for example nuclear reactor, can be obtained based on the cross-correlation method, which has already been shown that it is capable in situations where no other flow meter can be used. Thereby, the flow rate can be derived in pipe flow if the area of cross-section is known. In practice, the evaluation of the integrals over the measurement time in cross-correlation method will lead errors caused by peak detection from flat cross correlation coefficient distribution or additional peaks. One Auto-Adaptive Impulse Response Function estimation is introduced and significantly narrower peak will be obtained. Fiber optic sensors are advantageous for temperature measurements in the reactor pressure vessels. However, the corrosive coolant (as liquid lead/lead alloy or molten salt coolant) is a barrier of the optic sensor in such application. Thermocouple with grounded stainless steel shielding material would have same life time with structure material in reactor, although thermocouple has relatively slow response. The degradation due to corrosion/erosion will not introduce measurement error or necessary calibration, because only the correlation between signals is taken into consideration during measurements. Experiments conducted in a testing hydraulic facility approved the considerable improvement of accuracy by this new algorithm using thermocouple temperature sensors. (author)
Newer anti-epileptic drugs, vitamin status and neuropathy: A cross-sectional analysis.

Science.gov (United States)

Cahill, V; McCorry, D; Soryal, I; Rajabally, Y A

Whether new antiepileptic drugs (AEDs) may result in neuropathy is unknown but possible given their effects on vitamin metabolism. This analysis aimed to determine frequency and correlates of neuropathy in subjects treated with new AEDs in relation to drug used, length of exposure and serum vitamin B12 and folate levels. We performed a cross-sectional study of 52 consecutive epileptic subjects. Presence of neuropathy was determined using the Utah Early Neuropathy Score (UENS). Exposure to anti-epileptic drugs was quantified. Serum vitamin B12 and folate levels were measured. Commonly used AEDs were levetiracetam (28/52), carbamazepine (20/52), lamotrigine (20/52), sodium valproate (10/52) and zonisamide (10/52). Eight of 52 (15.4%) patients had neuropathy. There was no association with any particular AED. Neuropathy correlated with age (P=0.038) and total exposure to AEDs (P=0.032). UENS correlated with age (P=0.001), total AED exposure (P=0.001) and serum vitamin B12L (P=0.018). Independent association of neuropathy was found with total AED exposure (P=0.032), but not age. UENS was independently associated with total exposure to AEDs (Pvitamin B12L (P=0.002), but not age. Serum vitamin B12 and folate levels were highly inter-correlated (Pvitamin B12 and folate metabolism. Although further research from controlled studies is needed and despite the presence of other possible confounding factors, monitoring for neuropathy and vitamin B12 and folate levels merits consideration in patients on long-term treatment with new AEDs. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Lumber intervertebral disk; Correlation with the signal intensity of magnetic resonance imaging and the histological changes

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Uchida, Ryusei; Takahashi, Sadao; Ando, Tadashi; Kumano, Kiyoshi; Hiranuma, Kenji; Kanazawa, Yousuke; Konishi, Seiji; Eguchi, Masanobu; Tanioka, Hisaya (KantoRosai Hospital, Kawasaki, Kanagawa (Japan))

1989-11-01

We studied to provide precise correlations between the intensity of MRI signals and the degenerative changes of the nucleus pulposes of the L4/5 intervertebral disk herniations. 23 cases with the L4/5 intervertebral disk herniations having surgical treatment were examined using Magnetom H 15 (1.5 tesla) with surface coil. The images were obtained with T2 images (long TR (1000{approx}1600 msec), TE (60{approx}90 msec)). The intensity was measured using FUJI densitometer FD 101 at the lumber vertebral body and the intervertebral disk. We calculated the L4/5 intervertebral disk degeneration ratio (determined by comparing the modified L4/5 MR signal intensity with the modified L2/3 MR signal itensity). Histological changes were examined in the cellular components of the nucleus pulposus (such as the number of the nucleus cells, nucleus cell nesting and HE stainability of the nucleus cell) and the matrics substance (such as fibrillation, hyaline degeneration and granular degeneration). Histochemical studies were performed using Scott's Method (AB-0.4 M MgCl{sub 2} Alcinophilia, AB-09 M, MgCl{sub 2} Alcinophilia) to investigate glycosaminoglycans of the nucleus pulposus. We compared the histological and histochemical changes with the MR L4/5 intervetebral disk degeneration ratio. The decreasing MRI signal intensity of the nucleous pulposus was (1) corresponded to the pathological changes such as the increasing number of the cell nesting, fibrillation and hyaline degeneration of the nucleus polposus. (2) corresponded to the decrease in the total glycosaminoglycans of the nucleus pulposus. (3) corresponded to the early stage of degeneration of the nucleus polposus, but in aging when all levels of intervertebral disk degeneration appeared, we could not know the degree of the disk degeneration from the signal intensity of MRI. (J.P.N.).
Multiscale Characterization of PM2.5 in Southern Taiwan based on Noise-assisted Multivariate Empirical Mode Decomposition and Time-dependent Intrinsic Correlation

Science.gov (United States)

Hsiao, Y. R.; Tsai, C.

2017-12-01

As the WHO Air Quality Guideline indicates, ambient air pollution exposes world populations under threat of fatal symptoms (e.g. heart disease, lung cancer, asthma etc.), raising concerns of air pollution sources and relative factors. This study presents a novel approach to investigating the multiscale variations of PM2.5 in southern Taiwan over the past decade, with four meteorological influencing factors (Temperature, relative humidity, precipitation and wind speed),based on Noise-assisted Multivariate Empirical Mode Decomposition(NAMEMD) algorithm, Hilbert Spectral Analysis(HSA) and Time-dependent Intrinsic Correlation(TDIC) method. NAMEMD algorithm is a fully data-driven approach designed for nonlinear and nonstationary multivariate signals, and is performed to decompose multivariate signals into a collection of channels of Intrinsic Mode Functions (IMFs). TDIC method is an EMD-based method using a set of sliding window sizes to quantify localized correlation coefficients for multiscale signals. With the alignment property and quasi-dyadic filter bank of NAMEMD algorithm, one is able to produce same number of IMFs for all variables and estimates the cross correlation in a more accurate way. The performance of spectral representation of NAMEMD-HSA method is compared with Complementary Empirical Mode Decomposition/ Hilbert Spectral Analysis (CEEMD-HSA) and Wavelet Analysis. The nature of NAMAMD-based TDICC analysis is then compared with CEEMD-based TDIC analysis and the traditional correlation analysis.
A method to determine the necessity for global signal regression in resting-state fMRI studies.

Science.gov (United States)

Chen, Gang; Chen, Guangyu; Xie, Chunming; Ward, B Douglas; Li, Wenjun; Antuono, Piero; Li, Shi-Jiang

2012-12-01

In resting-state functional MRI studies, the global signal (operationally defined as the global average of resting-state functional MRI time courses) is often considered a nuisance effect and commonly removed in preprocessing. This global signal regression method can introduce artifacts, such as false anticorrelated resting-state networks in functional connectivity analyses. Therefore, the efficacy of this technique as a correction tool remains questionable. In this article, we establish that the accuracy of the estimated global signal is determined by the level of global noise (i.e., non-neural noise that has a global effect on the resting-state functional MRI signal). When the global noise level is low, the global signal resembles the resting-state functional MRI time courses of the largest cluster, but not those of the global noise. Using real data, we demonstrate that the global signal is strongly correlated with the default mode network components and has biological significance. These results call into question whether or not global signal regression should be applied. We introduce a method to quantify global noise levels. We show that a criteria for global signal regression can be found based on the method. By using the criteria, one can determine whether to include or exclude the global signal regression in minimizing errors in functional connectivity measures. Copyright © 2012 Wiley Periodicals, Inc.
Statistics of the derivatives of complex signal derived from Riesz transform and its application to pseudo-Stokes vector correlation for speckle displacement measurement

DEFF Research Database (Denmark)

Zhang, Shun; Yang, Yi; Hanson, Steen Grüner

2015-01-01

for the superiority of the proposed PSVC technique, we study the statistical properties of the spatial derivatives of the complex signal representation generated from the Riesz transform. Under the assumption of a Gaussian random process, a theoretical analysis for the pseudo Stokes vector correlation has been...... provided. Based on these results, we show mathematically that PSVC has a performance advantage over conventional intensity-based correlation technique....
Correlations between histology and neuronal activity recorded by microelectrodes implanted chronically in the cerebral cortex

Science.gov (United States)

McCreery, Douglas; Cogan, Stuart; Kane, Sheryl; Pikov, Victor

2016-06-01

Objective. To quantify relations between the neuronal activity recorded with chronically-implanted intracortical microelectrodes and the histology of the surrounding tissue, using radial distance from the tip sites and time after array implantation as parameters. Approach. ‘Utah’-type intracortical microelectrode arrays were implanted into cats’ sensorimotor cortex for 275-364 days. The brain tissue around the implants was immuno-stained for the neuronal marker NeuN and for the astrocyte marker GFAP. Pearson’s product-moment correlations were used to quantify the relations between these markers and the amplitudes of the recorded neuronal action potentials (APs) and their signal-to-noise ratios (S/N). Main results. S/N was more stable over post-implant time than was AP amplitude, but its increased correlation with neuronal density after many months indicates ongoing loss of neurons around the microelectrodes. S/N was correlated with neuron density out to at least 140 μm from the microelectrodes, while AP amplitude was correlated with neuron density and GFAP density within ˜80 μm. Correlations between AP amplitude and histology markers (GFAP and NeuN density) were strongest immediately after implantation, while correlation between the neuron density and S/N was strongest near the time the animals were sacrificed. Unlike AP amplitude, there was no significant correlation between S/N and density of GFAP around the tip sites. Significance. Our findings indicate an evolving interaction between changes in the tissue surrounding the microelectrodes and the microelectrode’s electrical properties. Ongoing loss of neurons around recording microelectrodes, and the interactions between their delayed electrical deterioration and early tissue scarring around the tips appear to pose the greatest threats to the microelectrodes’ long-term functionality.
Quorum sensing Inhibitors as anti-pathogenic drugs

DEFF Research Database (Denmark)

Rasmussen, Thomas Bovbjerg; Givskov, Michael Christian

2006-01-01

as well as elevated tolerance to the activity of the innate immune system. Gram-negative bacteria commonly use N-acyl homoserine lactones (AHL) as QS signal molecules. The use of signal molecule based drugs to attenuate bacterial pathogenecity rather than bacterial growth is attractive for several reasons......, particularly considering the emergence of increasingly antibiotic-resistant bacteria. Compounds capable of this type of interference have been termed anti-pathogenic drugs. A large variety of synthetic AHL analogues and natural products libraries have been screened and a number of QS inhibitors (QSI) have been...
Quantifying the microvascular origin of BOLD-fMRI from first principles with two-photon microscopy and an oxygen-sensitive nanoprobe.

Science.gov (United States)

Gagnon, Louis; Sakadžić, Sava; Lesage, Frédéric; Musacchia, Joseph J; Lefebvre, Joël; Fang, Qianqian; Yücel, Meryem A; Evans, Karleyton C; Mandeville, Emiri T; Cohen-Adad, Jülien; Polimeni, Jonathan R; Yaseen, Mohammad A; Lo, Eng H; Greve, Douglas N; Buxton, Richard B; Dale, Anders M; Devor, Anna; Boas, David A

2015-02-25

The blood oxygenation level-dependent (BOLD) contrast is widely used in functional magnetic resonance imaging (fMRI) studies aimed at investigating neuronal activity. However, the BOLD signal reflects changes in blood volume and oxygenation rather than neuronal activity per se. Therefore, understanding the transformation of microscopic vascular behavior into macroscopic BOLD signals is at the foundation of physiologically informed noninvasive neuroimaging. Here, we use oxygen-sensitive two-photon microscopy to measure the BOLD-relevant microvascular physiology occurring within a typical rodent fMRI voxel and predict the BOLD signal from first principles using those measurements. The predictive power of the approach is illustrated by quantifying variations in the BOLD signal induced by the morphological folding of the human cortex. This framework is then used to quantify the contribution of individual vascular compartments and other factors to the BOLD signal for different magnet strengths and pulse sequences. Copyright © 2015 the authors 0270-6474/15/353663-13$15.00/0.
Quantitative measurement of intervertebral disc signal using MRI

International Nuclear Information System (INIS)

Niemelaeinen, R.; Videman, T.; Dhillon, S.S.; Battie, M.C.

2008-01-01

Aim: To investigate the spinal cord as an alternative intra-body reference to cerebrospinal fluid (CSF) in evaluating thoracic disc signal intensity. Materials and methods: T2-weighted magnetic resonance imaging (MRI) images of T6-T12 were obtained using 1.5 T machines for a population-based sample of 523 men aged 35-70 years. Quantitative data on the signal intensities were acquired using an image analysis program (SpEx (copy right) ). A random sample of 30 subjects and intraclass correlation coeffcients (ICC) were used to examine the repeatability of the spinal cord measurements. The validity of using the spinal cord as a reference was examined by correlating cord and CSF samples. Finally, thoracic disc signal was validated by correlating it with age without adjustment and adjusting for either cord or CSF. Pearson's r was used for correlational analyses. Results: The repeatability of the spinal cord signal measurements was extremely high (≥0.99). The correlations between the signals of spinal cord and CSF by level were all above 0.9. The spinal cord-adjusted disc signal and age correlated similarly with CSF-adjusted disc signal and age (r = -0.30 to -0.40 versus r = -0.26 to -0.36). Conclusion: Adjacent spinal cord is a good alternative reference to the current reference standard, CSF, for quantitative measurements of disc signal intensity. Clearly fewer levels were excluded when using spinal cord as compared to CSF due to missing reference samples
Quantitative measurement of intervertebral disc signal using MRI

Energy Technology Data Exchange (ETDEWEB)

Niemelaeinen, R. [Faculty of Rehabilitation Medicine, University of Alberta, Edmonton (Canada)], E-mail: riikka.niemelainen@ualberta.ca; Videman, T. [Faculty of Rehabilitation Medicine, University of Alberta, Edmonton (Canada); Dhillon, S.S. [Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton (Canada); Battie, M.C. [Faculty of Rehabilitation Medicine, University of Alberta, Edmonton (Canada)

2008-03-15

Aim: To investigate the spinal cord as an alternative intra-body reference to cerebrospinal fluid (CSF) in evaluating thoracic disc signal intensity. Materials and methods: T2-weighted magnetic resonance imaging (MRI) images of T6-T12 were obtained using 1.5 T machines for a population-based sample of 523 men aged 35-70 years. Quantitative data on the signal intensities were acquired using an image analysis program (SpEx (copy right) ). A random sample of 30 subjects and intraclass correlation coeffcients (ICC) were used to examine the repeatability of the spinal cord measurements. The validity of using the spinal cord as a reference was examined by correlating cord and CSF samples. Finally, thoracic disc signal was validated by correlating it with age without adjustment and adjusting for either cord or CSF. Pearson's r was used for correlational analyses. Results: The repeatability of the spinal cord signal measurements was extremely high ({>=}0.99). The correlations between the signals of spinal cord and CSF by level were all above 0.9. The spinal cord-adjusted disc signal and age correlated similarly with CSF-adjusted disc signal and age (r = -0.30 to -0.40 versus r = -0.26 to -0.36). Conclusion: Adjacent spinal cord is a good alternative reference to the current reference standard, CSF, for quantitative measurements of disc signal intensity. Clearly fewer levels were excluded when using spinal cord as compared to CSF due to missing reference samples.
Geneva University: On our way to anti-hydrogen at rest

CERN Multimedia

Geneva University

2010-01-01

Ecole de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 GENEVA 4 Tel: (022) 379 62 73 Fax: (022) 379 69 92 Wednesday 28 April 2010 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium On our way to anti-hydrogen at rest Prof. Walter Oelert, Research Center Jülich, Germany Trapped cold atoms of anti-hydrogen are optimal for testing possible CPT violations in comparison of spectral lines and gravitational effects on matter and anti-matter. For this reason it is mandatory to optimize the properties of the clouds of anti-protons and positrons used to produce the anti-hydrogen atoms. The ATRAP-collaboration at CERNs AD did perform such experiments by studying the temperature of these clouds and their stability at different conditions. Though detailed tests have been performed to verify the trapping of anti-hydrogen atoms in a magnetic gradient field no statistically significant signal was detected yet. Re...
Celecoxib alleviates tamoxifen-instigated angiogenic effects by ROS-dependent VEGF/VEGFR2 autocrine signaling

International Nuclear Information System (INIS)

Kumar, B N Prashanth; Rajput, Shashi; Dey, Kaushik Kumar; Parekh, Aditya; Das, Subhasis; Mazumdar, Abhijit; Mandal, Mahitosh

2013-01-01

Tamoxifen (TAM) is widely used in the chemotherapy of breast cancer and as a preventive agent against recurrence after surgery. However, extended TAM administration for breast cancer induces increased VEGF levels in patients, promoting new blood vessel formation and thereby limiting its efficacy. Celecoxib (CXB), a selective COX-2 inhibitor, suppresses VEGF gene expression by targeting the VEGF promoter responsible for its inhibitory effect. For this study, we had selected CXB as non-steroidal anti-inflammatory drug in combination with TAM for suppressing VEGF expression and simultaneously reducing doses of both the drugs. The effects of CXB combined with TAM were examined in two human breast cancer cell lines in culture, MCF7 and MDA-MB-231. Assays of proliferation, apoptosis, angiogenesis, metastasis, cell cycle distribution, and receptor signaling were performed. Here, we elucidated how the combination of TAM and CXB at nontoxic doses exerts anti-angiogenic effects by specifically targeting VEGF/VEGFR2 autocrine signaling through ROS generation. At the molecular level, TAM-CXB suppresses VHL-mediated HIF-1α activation, responsible for expression of COX-2, MMP-2 and VEGF. Besides low VEGF levels, TAM-CXB also suppresses VEGFR2 expression, confirmed through quantifying secreted VEGF levels, luciferase and RT-PCR studies. Interestingly, we observed that TAM-CXB was effective in blocking VEGFR2 promoter induced expression and further 2 fold decrease in VEGF levels was observed in combination than TAM alone in both cell lines. Secondly, TAM-CXB regulated VEGFR2 inhibits Src expression, responsible for tumor progression and metastasis. FACS and in vivo enzymatic studies showed significant increase in the reactive oxygen species upon TAM-CXB treatment. Taken together, our experimental results indicate that this additive combination shows promising outcome in anti-metastatic and apoptotic studies. In a line, our preclinical studies evidenced that this additive
Polyphenolic acetates: A newer anti-Mycobacterial therapeutic option

African Journals Online (AJOL)

Anti acetyl lysine polyclonal antibody was purchased from Cell Signaling. ... acetyl group from various polyphenolic peracetate (PA) to certain receptor proteins such as cytochromes P-450, NADPH cytochrome reductase, nitric oxide synthase (NOS) has been established in various eukaryotic as well as prokaryotic sources.
Anti-Mullerian hormone and ovarian dysfunction

NARCIS (Netherlands)

Broekmans, Frank J.; Visser, Jenny A.; Laven, Joop S. E.; Broer, Simone L.; Themmen, Axel P. N.; Fauser, Bart C.

2008-01-01

Anti-Mullerian hormone (AMH) has important roles in postnatal ovarian function. Produced by ovarian granulosa cells, AMH is involved in initial follicle development. In fact, serum AMH level correlates with ovarian follicle number. In patients with polycystic ovary syndrome (PCOS), AMH levels are

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