bluuebunny/crossref_metadata_2025 huggingface dataset:
BASE WAVELET SELECTION FOR BEARING VIBRATION SIGNAL ANALYSIS
Authors: YAN RUQIANG , GAO ROBERT X.
Published: July 2009

A critical issue to ensuring the effectiveness of wavelet transform in machine condition monitoring and health diagnosis is the choice of the most suited base wavelet for signal decomposition and feature extraction. This paper addresses this issue by introducing a quantitative measure to select an appropriate base wavelet for analyzing vibration signals measured on rotary mechanical systems. Specifically, the measure based on energy-to-Shannon entropy ratio has been investigated. Both the simulated Gaussian-modulated sinusoidal signal and an actual ball bearing vibration signal have been used to evaluate the effectiveness of the developed measure on base wavelet selection. Experimental results demonstrate that the wavelet selected using the developed measure is better suited than other wavelets in diagnosing structural defects in the bearing. The method developed provides systematic guidance in wavelet selection.
SYNCHRONOUS ENHANCEMENT OF PERIODIC TRANSIENTS ON POLAR DIAGRAM FOR MACHINE FAULT DIAGNOSIS
Authors: ZHU Z. K. , HE ZHIYONG , WANG ANZHU , WANG SHIBIN
Published: July 2009

A periodic transient detection and representation method, termed synchronous enhancement of periodic feature (SEPF), based on the Continuous Wavelet Transform (CWT) is proposed. This method first represents a given signal in the time-scale domain through CWT and then maps the resulted wavelet coefficients into the polar diagram using the given potential periods. Transient features would thus be synchronously enhanced at a certain area if the mapping time period matches that of the transient vibrations. The simulation study and the applications in the gearbox and bearing fault diagnosis verify the effectiveness of the proposed method in detecting the periodical transient vibrations.
EVALUATION OF NONSTATIONARY VEHICLE PASSING LOUDNESS BASED ON AN ANTINOISE WAVELET PRE-PROCESSING NEURAL NETWORK MODEL
Authors: WANG Y. S. , LEE C.-M.
Published: July 2009

A new technique for sound loudness evaluation, the so-called antinoise wavelet pre-processing neural network (ANWT-NN) model, is presented in this paper. Based on passing vehicle noise, the ANWT-NN loudness model combines the techniques of wavelet analysis and neural network regression and classification. A wavelet-based, 21-point model for vehicle noise feature extraction is established. Verification shows that the trained ANWT-NN models are more accurate and effective than the WT-NN models for sound quality evaluation of nonstationary vehicle noises. The newly proposed ANWT-NN model can be applied to both the stationary and nonstationary sound signals and even to the transient ones. The ANWT-NN technique is suggested not only for the prediction, classification, and comparison of the sound quality of passing vehicle noise, but also for applications in other sound-related engineering fields, in place of the conventional psychoacoustical models.
THE FLEXIBLE GABOR-WAVELET TRANSFORM FOR CAR CRASH SIGNAL ANALYSIS
Authors: ONCHIŞ DARIAN M. , SÚAREZ SÁNCHEZ ESPERANZA M.
Published: July 2009

This paper is concerned with the spectral decomposition and the adaptive analysis of data coming from car crash simulations. The mathematical ingredient of the proposed signal processing technique is the flexible Gabor-wavelet transform or the α-transform that reliably detects both high and low frequency components of such complicated short-time signals. We go from the functional treatment of this wavelet-type transform to its numerical implementation and we show how it can be used as an improved tool for spectral investigations compared to the short-time Fourier transform or the classical wavelet transform.
MECHANICAL WATCH SIGNATURE ANALYSIS BASED ON WAVELET DECOMPOSITION
Authors: HE QINGBO , DU RUXU
Published: July 2009

The acoustic signal of mechanical watch is a distinct multi-component signal. It contains many frequency components corresponding to specific escapement motion sources with a very wide frequency range. Therefore, it is challenging for signature analysis of mechanical watch by the acoustic signal. This paper studies the time-frequency signatures of the mechanical watch based on wavelet decomposition. Two methods are proposed to improve the frequency resolution of traditional wavelet techniques by combining other beneficial techniques in the sense of decomposing specific mono- or independent components. The empirical mode decomposition (EMD) is presented to advance the wavelet packet decomposition (WPD) to decompose the mono-component signals. And the blind source separation (BSS) makes the redundancy of continuous wavelet transform (CWT) further gain good frequency resolution in the independent meaning. The decomposed signals by the two methods reveal the insight of mechanical watch movement and can contribute much simpler and clearer time-frequency signatures. Experimental results indicated the effectiveness of the two methods and the value of the time-frequency signatures in analyzing and diagnosing mechanical watch movements.
WAVELET PACKET DECOMPOSITION FOR THE IDENTIFICATION OF CORROSION TYPE FROM ACOUSTIC EMISSION SIGNALS
Authors: VAN DIJCK GERT , WEVERS MARTINE , VAN HULLE MARC M.
Published: July 2009

Corrosion causes a degradation of the structural integrity of petrochemical plants, nuclear power plants, ships, bridges and other constructions containing steel with the consequence that people and the environment may be exposed to dangerous situations. The detection of corrosion and the prediction of the type of corrosion are studied in this article by means of the acoustic emission technique. We use a wavelet packet decomposition to compute features from the acoustic emission signals. The basis functions with the highest discriminative power are selected according to the highest pair-wise Kullback–Leibler divergence between distributions of wavelet coefficients. It is proven that the pair-wise Kullback–Leibler divergence used in the local discriminant basis algorithm requires class conditional independence of the wavelet coefficients. Several classification algorithms using the most discriminative wavelet coefficients are compared for the prediction of three types of corrosion and the absence of corrosion.
A TUTORIAL OF TECHNIQUES FOR IMPROVING STANDARD HIDDEN MARKOV MODEL ALGORITHMS
Authors: GOLOD DANIIL , BROWN DANIEL G.
Published: July 2009

In this tutorial, we discuss two main algorithms for Hidden Markov Models or HMMs: the Viterbi algorithm and the expectation phase of the Baum–Welch algorithm, and we describe ways to improve their naïve implementations. For the Baum–Welch algorithm we first present an implementation of the expectation computations using constant space. We then discuss the classical implementation of this calculation and describe ways to reduce its space usage to logarithmic and [Formula: see text], with their respective CPU costs. We also note where each respective algorithm can be parallelized. For the Viterbi algorithm, we describe [Formula: see text] and logarithmic space algorithms which increase CPU use by a factor of two and by a logarithmic factor respectively. We also present two recent heuristics for decreasing space use, which in practice lead to logarithmic space use. Classical version of Viterbi cannot be parallelized by splitting sequence in several subsequences, but we show a parallelization that works if we are willing to pay a significant extra CPU cost. Finally we show a very simple parallelization trick which enables full usage of multiple CPUs/cores under the condition that they share memory.
CLUSTERING-BASED APPROACH FOR PREDICTING MOTIF PAIRS FROM PROTEIN INTERACTION DATA
Authors: LEUNG HENRY CHI-MING , SIU MAN-HUNG , YIU SIU-MING , CHIN FRANCIS YUK-LUN , SUNG KEN WING-KIN
Published: July 2009

Predicting motif pairs from a set of protein sequences based on the protein–protein interaction data is an important, but difficult computational problem. Tan et al. proposed a solution to this problem. However, the scoring function (using χ2 testing) used in their approach is not adequate and their approach is also not scalable. It may take days to process a set of 5000 protein sequences with about 20,000 interactions. Later, Leung et al. proposed an improved scoring function and faster algorithms for solving the same problem. But, the model used in Leung et al. is complicated. The exact value of the scoring function is not easy to compute and an estimated value is used in practice. In this paper, we derive a better model to capture the significance of a given motif pair based on a clustering notion. We develop a fast heuristic algorithm to solve the problem. The algorithm is able to locate the correct motif pair in the yeast data set in about 45 minutes for 5000 protein sequences and 20,000 interactions. Moreover, we derive a lower bound result for the p-value of a motif pair in order for it to be distinguishable from random motif pairs. The lower bound result has been verified using simulated data sets. Availability:
CURVE-BASED CLUSTERING OF TIME COURSE GENE EXPRESSION DATA USING SELF-ORGANIZING MAPS
Authors: CHEN XIN
Published: July 2009

There is an increasing interest in clustering time course gene expression data to investigate a wide range of biological processes. However, developing a clustering algorithm ideal for time course gene express data is still challenging. As timing is an important factor in defining true clusters, a clustering algorithm shall explore expression correlations between time points in order to achieve a high clustering accuracy. Moreover, inter-cluster gene relationships are often desired in order to facilitate the computational inference of biological pathways and regulatory networks. In this paper, a new clustering algorithm called CurveSOM is developed to offer both features above. It first presents each gene by a cubic smoothing spline fitted to the time course expression profile, and then groups genes into clusters by applying a self-organizing map-based clustering on the resulting splines. CurveSOM has been tested on three well-studied yeast cell cycle datasets, and compared with four popular programs including Cluster 3.0, GENECLUSTER, MCLUST, and SSClust. The results show that CurveSOM is a very promising tool for the exploratory analysis of time course expression data, as it is not only able to group genes into clusters with high accuracy but also able to find true time-shifted correlations of expression patterns across clusters.
FAST NONLINEAR FOURIER EXPANSIONS
Authors: WANG RUI , XU YUESHENG , ZHANG HAIZHANG
Published: July 2009

Motivated by the analytic signal approach and general construction methods by Qian et al. (accepted by Adv. Comput. Math.), we construct a class of orthonormal bases for the real signal space [Formula: see text], which have nonconstant physically meaningful instantaneous frequencies. We develop a fast algorithm for computing the Hilbert–Fourier expansion of a given function in terms of the orthonormal bases. Moreover, we study the approximation properties of the Hilbert–Fourier expansion. A numerical example is presented to demonstrate an adaptive Fourier expansion based on an optimal selection of the parameter a in the orthonormal bases according to the approximation error.
APPLICATION OF THE EMPIRICAL MODE DECOMPOSITION TO FIELD TILTMETER DATA FOR HYDRAULIC FRACTURE MAPPING
Authors: CHEN ZUORONG , JEFFREY ROBERT G.
Published: July 2009

Empirical Mode Decomposition (EMD) is a fully data-driven, adaptive technique for analyzing time series from nonlinear and nonstationary processes. The starting point of EMD is to treat the signal as a superposition of different intrinsic modes of oscillations (fast oscillations superimposed on slow oscillations). The essence of this method is to empirically identify the intrinsic oscillatory modes by their characteristic time scale imbedded in a signal, and then decompose the signal into a collection of a finite and often small number of intrinsic mode functions (IMF) through a so-called sifting process. Each IMF component then represents only one mode of both amplitude and frequency modulated oscillation of the signal at a certain time scale or frequency band, and the sum of all the IMF components as well as a residual produces a perfect reconstruction of the original signal. Partial reconstruction can be achieved by selectively removing fast or slowly varying IMFs, which provides a method to remove unwanted (noise) parts of the signal.

In this paper, the EMD is applied to quantitative analysis of field tiltmeter data collected to monitor and map hydraulic fractures. The fracture-related tilt components are extracted by identifying the relevant IMFs that contribute to them, which allows removing the noise and background trend components from the raw data. The extracted tilt data are then inverted to obtain the volume and orientation of the hydraulic fractures. Physically reasonable prediction of the hydraulic fracture volume is used to demonstrate that the application of EMD to field tiltmeter data analyzing can be successfully carried out.
THE NONLINEAR AND NONSTATIONARY PROPERTIES IN EEG SIGNALS: PROBING THE COMPLEX FLUCTUATIONS BY HILBERT–HUANG TRANSFORM
Authors: LO MEN-TZUNG , TSAI PING-HUANG , LIN PEI-FENG , LIN CHEN , HSIN YUE LOONG
Published: July 2009

The analysis of biological fluctuations provides an excellent route to probe the underlying mechanisms in maintaining internal homeostasis of the body, especially under the challenges of the ever-changing environment or disease processes. However, the features of nonlinearity and nonstationarity in physiological time series limit the reliability of the conventional analysis. Hilbert–Huang transform (HHT), based on nonlinear theory, is an innovative approach to extract the dynamic information at different time scales, in particular, from nonstationary signals. In this paper, HHT is introduced to analyze the alpha waves of human's electroencephalography (EEG), which seemly oscillate regularly between 8 and 12 Hz in healthy subject but getting irregular or disappeared in different demented status. Furthermore, conventional time–frequency analyses are adopted to collate the results from those methods and HHT. Finally, the potential usages of HHT are demonstrated in characterizing the biological signals qualitatively and quantitatively, including stationarity analysis, instantaneous frequency and amplitude modulation or correlation analysis. Such applications on EEG have successively disclosed the differences of alpha rhythms between normal and demented brains and the nonlinear characteristics of the underlying mechanisms. Hopefully, in addition to empower the studies of EEG varied in diseased, aging, and physiological processes, these methods might find other applications in EEG analysis.
Caveolin-1 plays important role in EGF-induced migration and proliferation of mouse embryonic stem cells: involvement of PI3K/Akt and ERK
Authors: Park Jae Hong , Han Ho Jae
Published: July 2009

The involvement of caveolin-1 in the regulation of embryonic stem (ES) cell growth by epidermal growth factor (EGF) is by no means clear cut. Thus we examined the relationship between EGF and caveolin-1 in mouse ES cell migration and proliferation. The results revealed that EGF increased Src, caveolin-1, focal adhesion kinase (FAK), Akt, and extracellular signal-regulated kinase-1/2 (ERK) phosphorylation levels. Especially, phosphorylation of caveolin-1 is attenuated by AG1478, herbimycin A (tyrosine kinase inhibitors), and pyrazolopyrimidine 2 (PP2, Src inhibitor) and EGF-induced ERK activation was blocked by PP2, methyl-β-cyclodextrin (MβCD), caveolin-1 small interfering RNA (siRNA), LY-294002 [phosphoinositol-3 kinase inhibitor (PI3K)], and Akt inhibitor. In addition, EGF promoted the cell migration, which was attenuated by PP2, caveolin-1 siRNA, FAK siRNA, LY-294002, Akt inhibitor, and PD-98059. EGF also increased matrix metalloproteinase (MMP-2) expression levels and EGF-induced MMP2 expression was inhibited by caveolin-1 siRNA, FAK siRNA, LY-294002, Akt inhibitor, and PD-98059. Furthermore, EGF-induced increase of cell cycle proteins expression level and [3H]thymidine incorporation was blocked by MMP inhibitor. EGF also significantly increases [3H]thymidine incorporation and cell number, which were significantly blocked by AG 1478, PP2, MβCD, caveolin-1 siRNA, FAK siRNA, LY-294002, and PD-98059 (ERK inhibitor). EGF-induced increase of protooncogenes (c- fos, c- myc, and c- Jun) and cell cycle regulatory proteins (cyclin D1, CDK4, cyclin E, and CDK2) expression levels were also attenuated by caveolin-1 siRNA and FAK siRNA. In conclusion, these results demonstrated that EGF-induced DNA synthesis and cell migration are mediated by caveolin-1, which is activated by Src, FAK, PI3K/Akt, ERK, and MMP-2 signals in mouse ES cells.
Functional characterization of two isoforms of the P2Y-like receptor GPR17: [35S]GTPγS binding and electrophysiological studies in 1321N1 cells
Authors: Pugliese Anna Maria , Trincavelli Maria Letizia , Lecca Davide , Coppi Elisabetta , Fumagalli Marta , Ferrario Silvia , Failli Paola , Daniele Simona , Martini Claudia , Pedata Felicita , Abbracchio Maria P.
Published: July 2009

The previously “orphan” G protein-coupled receptor GPR17 is structurally related to both P2Y nucleotide receptors and to receptors for cysteinyl leukotrienes. Genomic analysis revealed two putative open reading frames encoding for a “short” and a “long” receptor isoform of 339- and 367-amino acids, respectively, with the latter displaying a 28-amino acid longer NH2terminus. The short isoform has been recently “deorphanized,” revealing dual responses to uracil nucleotides and cysteinyl leukotrienes. No information regarding the ligand specificity, tissue distribution, or pathophysiological roles of the long receptor isoform is available. In the present study, we cloned human long-GPR17, determined its tissue distribution, and characterized its pharmacological specificity in 1321N1 cells by [35S]GTPγS binding (which measures the ability of G protein-coupled receptor agonists to increase GTP binding to G proteins) and whole cell patch-clamp recording measuring receptor coupling to K+channels. [35S]GTPγS binding in long-GPR17-expressing 1321N1 cells revealed concentration-dependent responses to uracil nucleotides (UDP-galactose = UDP > UDP-glucose) and cysteinyl leukotrienes (LTC4> LTD4), which were counteracted by a purinergic (cangrelor) and a cysteinyl leukotriene antagonist (montelukast), respectively. The nonhydrolyzable ATP analog ATPγS also acted as an antagonist. GPR17 coupled to Giand, to a lesser extent, Gqproteins. UDP-glucose and LTD4also induced increases in overall outward K+currents, which were antagonized by the purinergic antagonists MRS2179 and cangrelor and by montelukast. We conclude that the previously uncharacterized long-GPR17 isoform is a functional receptor that is stimulated by both uracil nucleotides and cysteinyl leukotrienes. We also show that the signaling pathway of GPR17 involves the generation of outward K+currents, an important protective mechanism that, in brain, is specifically aimed at reducing neuronal hyperexcitability and resultant neuronal injury.
Sustained stimulation of vasopressin and oxytocin release by ATP and phenylephrine requires recruitment of desensitization-resistant P2X purinergic receptors
Authors: Gomes Dayane A. , Song Zhilin , Stevens Wanida , Sladek Celia D.
Published: July 2009

Coexposure of hypothalamo-neurohypophyseal system explants to ATP and phenylephrine [PE; an α1-adrenergic receptor (α1-AR) agonist] induces an extended elevation in vasopressin and oxytocin (VP/OT) release. New evidence is presented that this extended response is mediated by recruitment of desensitization-resistant ionotropic purinergic receptor subtypes (P2X-Rs): 1) Antagonists of the P2X2/3 and P2X7-Rs truncated the sustained VP/OT release induced by ATP+PE but did not alter the transient response to ATP alone. 2) The P2X2/3 and P2X7-R antagonists did not alter either ATP or ATP+PE-induced increases in [Ca2+]i. 3) P2X2/3 and P2X7-R agonists failed to elevate [Ca2+]i, while ATP-γ-S, an agonist for P2X2-Rs increased [Ca2+]iand induced a transient increase in VP/OT release. 4) A P2Y1-R antagonist did not prevent initiation of the synergistic, sustained stimulation of VP/OT release by ATP+PE but did reduce its duration. Thus, the desensitization-resistant P2X2/3 and P2X7-R subtypes are required for the sustained, synergistic hormone response to ATP+PE, while P2X2-Rs are responsible for the initial activation of Ca2+-influx by ATP and ATP stimulation of VP/OT release. Immunohistochemistry, coimmunoprecipitation, and Western blot analysis confirmed the presence of P2X2 and P2X3, P2X2/3, and P2X7-R protein, respectively in SON. These findings support the hypothesis that concurrent activation of P2X2-R and α1-AR induces calcium-driven recruitment of P2X2/3 and 7-Rs, allowing sustained activation of a homeostatic circuit. Recruitment of these receptors may provide sustained release of VP during dehydration and may be important for preventing hemorrhagic and septic shock.
A new role for vitamin D receptor activation in chronic kidney disease
Authors: Valdivielso José M. , Cannata-Andía Jorge , Coll Blai , Fernández Elvira
Published: July 2009

Vitamin D has proven to be much more than a simple “calcium hormone.” The fact that the vitamin D receptor has been found in cells not related to mineral metabolism supports that statement. The interest of nephrologists in vitamin D and its effects beyond mineral metabolism has increased over the last few years, evidencing the importance of this so-called “sunshine hormone.” In the present review, we highlight the most recent developments in the traditional use of vitamin D in chronic kidney disease (CKD) patients, namely, the control of secondary hyperparathyroidism (sHPT). Furthermore, we also explore the data available regarding the new possible therapeutic uses of vitamin D for the treatment of other complications present in CKD patients, such as vascular calcification, left ventricular hypertrophy, or proteinuria. Finally, some still scarce but very promising data regarding a possible role of vitamin D in kidney transplant patients also are reviewed. The available data point to a potential beneficial effect of vitamin D in CKD patients beyond the control of mineral metabolism.
Temporal analysis of signaling pathways activated in a murine model of two-kidney, one-clip hypertension
Authors: Cheng Jingfei , Zhou Wei , Warner Gina M. , Knudsen Bruce E. , Garovic Vesna D. , Gray Catherine E. , Lerman Lilach O. , Platt Jeffrey L. , Romero J. Carlos , Textor Stephen C. , Nath Karl A. , Grande Joseph P.
Published: July 2009

Unilateral renal artery stenosis (RAS) leads to atrophy of the stenotic kidney and compensatory enlargement of the contralateral kidney. Although the two-kidney, one-clip (2K1C) model has been extensively used to model human RAS, the cellular responses in the stenotic and contralateral kidneys, particularly in the murine model, have received relatively little attention. We studied mice 2, 5, and 11 wk after unilateral RAS. These mice became hypertensive within 1 wk. The contralateral kidney increased in size within 2 wk after surgery. This enlargement was associated with a transient increase in expression of phospho-extracellular signal-regulated kinase (p-ERK), the proliferation markers proliferating cell nuclear antigen and Ki-67, the cell cycle inhibitors p21 and p27, and transforming growth factor-β, with return to baseline levels by 11 wk. The size of the stenotic kidney was unchanged at 2 wk but progressively decreased between 5 and 11 wk. Unlike the contralateral kidney, which showed minimal histopathological alterations, the stenotic kidney developed progressive interstitial fibrosis, tubular atrophy, and interstitial inflammation. Surprisingly, the stenotic kidney showed a proliferative response, which involved largely tubular epithelial cells. The atrophic kidney had little evidence of apoptosis, despite persistent upregulation of p53; expression of cell cycle regulatory proteins in the stenotic kidney was persistently increased through 11 wk. These studies indicate that in the 2K1C model, the stenotic kidney and contralateral, enlarged kidney exhibit a distinct temporal expression of proteins involved in cell growth, cell survival, apoptosis, inflammation, and fibrosis. Notably, an unexpected proliferative response occurs in the stenotic kidney that undergoes atrophy.
Dynamic CO2 therapy in periodic breathing: a modeling study to determine optimal timing and dosage regimes
Authors: Mebrate Yoseph , Willson Keith , Manisty Charlotte H. , Baruah Resham , Mayet Jamil , Hughes Alun D. , Parker Kim H. , Francis Darrel P.
Published: July 2009

We examine the potential to treat unstable ventilatory control (seen in periodic breathing, Cheyne-Stokes respiration, and central sleep apnea) with carefully controlled dynamic administration of supplementary CO2, aiming to reduce ventilatory oscillations with minimum increment in mean CO2. We used a standard mathematical model to explore the consequences of phasic CO2 administration, with different timing and dosing algorithms. We found an optimal time window within the ventilation cycle (covering ∼1/6 of the cycle) during which CO2 delivery reduces ventilatory fluctuations by >95%. Outside that time, therapy is dramatically less effective: indeed, for more than two-thirds of the cycle, therapy increases ventilatory fluctuations >30%. Efficiency of stabilizing ventilation improved when the algorithm gave a graded increase in CO2 dose (by controlling its duration or concentration) for more severe periodic breathing. Combining gradations of duration and concentration further increased efficiency of therapy by 22%. The (undesirable) increment in mean end-tidal CO2 caused was 300 times smaller with dynamic therapy than with static therapy, to achieve the same degree of ventilatory stabilization (0.0005 vs. 0.1710 kPa). The increase in average ventilation was also much smaller with dynamic than static therapy (0.005 vs. 2.015 l/min). We conclude that, if administered dynamically, dramatically smaller quantities of CO2 could be used to reduce periodic breathing, with minimal adverse effects. Algorithms adjusting both duration and concentration in real time would achieve this most efficiently. If developed clinically as a therapy for periodic breathing, this would minimize excess acidosis, hyperventilation, and sympathetic overactivation, compared with static treatment.
Load Type Influences Motor Unit Recruitment in Biceps Brachii During a Sustained Contraction
Authors: Baudry Stéphane , Rudroff Thorsten , Pierpoint Lauren A. , Enoka Roger M.
Published: July 2009

Twenty subjects participated in four experiments designed to compare time to task failure and motor-unit recruitment threshold during contractions sustained at 15% of maximum as the elbow flexor muscles either supported an inertial load (position task) or exerted an equivalent constant torque against a rigid restraint (force task). Subcutaneous branched bipolar electrodes were used to record single motor unit activity from the biceps brachii muscle during ramp contractions performed before and at 50 and 90% of the time to failure for the position task during both fatiguing contractions. The time to task failure was briefer for the position task than for the force task ( P = 0.0002). Thirty and 29 motor units were isolated during the force and position tasks, respectively. The recruitment threshold declined by 48 and 30% ( P = 0.0001) during the position task for motor units with an initial recruitment threshold below and above the target force, respectively, whereas no significant change in recruitment threshold was observed during the force task. Changes in recruitment threshold were associated with a decrease in the mean discharge rate (−16%), an increase in discharge rate variability (+40%), and a prolongation of the first two interspike intervals (+29 and +13%). These data indicate that there were faster changes in motor unit recruitment and rate coding during the position task than the force task despite a similar net muscle torque during both tasks. Moreover, the results suggest that the differential synaptic input observed during the position task influences most of the motor unit pool.
On the Nature of the Intrinsic Connectivity of the Cat Motor Cortex: Evidence for a Recurrent Neural Network Topology
Authors: Capaday Charles , Ethier Christian , Brizzi Laurent , Sik Attila , van Vreeswijk Carl , Gingras Denis
Published: July 2009

The details and functional significance of the intrinsic horizontal connections between neurons in the motor cortex (MCx) remain to be clarified. To further elucidate the nature of this intracortical connectivity pattern, experiments were done on the MCx of three cats. The anterograde tracer biocytin was ejected iontophoretically in layers II, III, and V. Some 30–50 neurons within a radius of ∼250 μm were thus stained. The functional output of the motor cortical point at which biocytin was injected, and of the surrounding points, was identified by microstimulation and electromyographic recordings. The axonal arborizations of the stained neurons were traced under camera lucida. The axon collaterals were extensive, reaching distances of ≤7 mm from the injection site. More importantly, the axonal branches were studded all along their course with boutons. The vast majority of boutons formed synaptic contacts on the target cells as identified by electron microscopy. The majority of these boutons made asymmetric (type I, excitatory) synapses mainly on dendritic spines. The bouton density decreased approximately monotonically with distance from the center of the injection. Cluster analysis, lagged covariance analysis, and eigenvalue decomposition showed the bouton distribution map to be unimodal. Superposition of the synaptic bouton distribution map and the motor output map revealed that motor cortical neurons don't make point-to-point connections but rather bind together the representations of a variety of muscles within a large neighborhood. This recurrent-network type connectivity strongly supports the hypothesis that the MCx controls the musculature in an integrated manner.
Comparison of radiosensitizing effects of the mammalian target of rapamycin inhibitor CCI-779 to cisplatin in experimental models of head and neck squamous cell carcinoma
Authors: Ekshyyan Oleksandr , Rong Youhua , Rong Xiaohua , Pattani Kavita M. , Abreo Fleurette , Caldito Gloria , Chang John Kai Siung , Ampil Federico , Glass Jonathan , Nathan Cherie-Ann O.
Published: July 2009

To determine if the mammalian target of rapamycin (mTOR) inhibitor CCI-779 can sensitize head and neck squamous cell carcinoma (HNSCC) to radiotherapy (XRT) and compare the radiosensitizing effects to cisplatin with its known considerable toxicity. Radiosensitizing effects of CCI-779 were assayed on HNSCC cell lines in vitro. CCI-779 (5 mg/kg), cisplatin (1 mg/kg), and XRT (2 Gy) alone and in combination were evaluated for antitumor activity in mice bearing FaDu and SCC40 xenografts. Effects of CCI-779 on radiation-induced activation of the Akt/mTOR pathway were analyzed. Although CCI-779 did not sensitize HNSCC cells to ionizing radiation in vitro, combination of CCI-779 and XRT significantly augmented the in vivo tumor growth-inhibitory effects of XRT and CCI-779 (P < 0.05). In addition, CCI-779 + XRT suppressed tumor growth more effectively than cisplatin + XRT (P < 0.05). CCI-779 + XRT significantly improved survival compared with XRT alone in both cisplatin-sensitive FaDu (P < 0.01) and cisplatin-resistant SCC40 (P < 0.05) xenograft mice. There were no additional benefits of adding cisplatin to CCI-779 + XRT. CCI-779 significantly attenuated irradiation-induced up-regulation of the mTOR pathway, increased apoptosis and displayed potent antiangiogenic activity in FaDu xenografts that was further enhanced by its combination with XRT (P < 0.05), which may explain the mechanism of its selective radiosensitizing effects in vivo and not in vitro. Antitumor activity of XRT was enhanced when combined with CCI-779 in HNSCC xenograft model. CCI-779 + XRT showed antitumor activity superior to conventional chemoradiotherapy with cisplatin. These results pave the way for clinical trials using molecular targeted therapy with CCI-779 in combination with XRT for HNSCC treatment. [Mol Cancer Ther 2009;8(8):2255–65]
Pharmacokinetics and Pharmacodynamics of the Urotensin‐II Receptor Antagonist Palosuran in Healthy Male Subjects
Authors: Sidharta Patricia N. , van Giersbergen Paul L. M. , Dingemanse Jasper
Published: July 2009

Palosuran is a new potent and specific antagonist of the human urotensin II (U‐II) receptor (UT receptor). This entry‐into‐humans study evaluated the tolerability and safety, pharmacokinetics, and pharmacodynamics of palosuran in a double‐blind, placebo‐controlled, single ascending‐dose design. Oral doses of 5 to 2000 mg were given to 9 sequential groups of 8 healthy young men (6 on active drug, 2 on placebo) each. At regular intervals, tolerability and safety parameters and plasma levels of palosuran and U‐II were determined. Urine was collected to determine excretion of sodium, potassium, creatinine, and palosuran. In this study, palosuran was well tolerated. No serious adverse events or dose‐related adverse events were reported. No treatment‐related pattern was detected for vital signs, clinical laboratory parameters, or electrocardiography parameters. After rapid absorption, palosuran displayed a plasma concentration‐time profile characterized by 2 peaks at approximately 1 and 4 hours after drug administration. The apparent terminal elimination half‐life was approximately 20 hours. AUC and Cmax values increased proportionally with doses up to 500 mg. Excretion of unchanged palosuran in urine was limited. No consistent effect was found on any of the pharmacodynamic variables measured. The results of this entry‐into‐humans study warrant further investigation of the therapeutic potential of palosuran.
Psychological Distance and Group Judgments: The Effect of Physical Distance on Beliefs about Common Goals
Authors: Henderson Marlone D.
Published: July 2009

The present research examined the consequences of physical distance on beliefs about common goals, which have been implicated in judgments of entitativeness (“groupness”) of social entities. A central feature of task groups is the degree to which its members are driven by common goals. According to construal level theory, as stimuli are removed psychologically (e.g., physically), people construe stimuli in more abstract terms, focusing more on central features of stimuli. Adopting this framework, four studies demonstrated that people are more likely to assume the behavior of task group members is driven by common goals for physically distant rather than near groups. This effect occurred when perceived identification and similarity to others were held constant. Implications for intergroup relations are discussed.
The Impact of Work Interferences on Family Caregiver Outcomes
Authors: Colin Reid R. , Stajduhar Kelli I. , Chappell Neena L.
Published: July 2009

Most research into caregiver employment and outcomes conceives of employment as a dichotomous variable—employed or not. This study examines the relationship between work interferences and caregiver burden, well-being, and self-esteem within a modified stress process model. Regression models are employed using a population-based random sample of caregivers. Employment status effects on outcomes for the total sample are estimated, followed by estimations of the effects of work interferences on the same outcomes for the employed subsample. Employment status is unrelated to outcomes in the total sample. In the employed subsample, a 13-item work interferences scale is related to burden but unrelated to well-being and self-esteem. Of the 13 items, only “performance at work was affected because of caring for a care recipient” is associated with all three caregiver outcomes. These findings suggest that subjective assessment of work interferences may play a more important role than does employment status.
Justice by Any Means Necessary: Vigilantism among Indian Women
Authors: White Aaronette , Rastogi Shagun
Published: July 2009

Through an analysis of news reports and documentary footage on the Gulabi Gang and ethnographic reports on the Mahila Aghadi, both of India, we illustrate how women who engage in violent forms of justice-seeking require us to expand social psychological concepts of retributive and restorative models of justice, women's agency, and community organizing. Our grassroots feminist analysis in an Indian context integrates: (1) feminist definitions of punishment and ethical violence; (2) research on perceptions of justice and moral convictions; and, (3) the feminist and liberatory roles that women's and poor people's movements play in the reorganization and recovery of individual and community values.
Present but Un-named: Feminist Liberation Psychology in Portugal
Authors: de Oliveira João Manuel , Neves Sofia , Nogueira Conceição , De Koning Marijke
Published: July 2009

In this article, we intend to show the paradox of Portuguese feminist liberation psychology, a discipline that is present inside the practical domain of social interventions, but remains unnamed. We aim to reveal examples of the few practices of feminist liberation psychology that exist in Portugal in order to inscribe them into the academic field. This article emphasizes some experiences from one grassroots movement that could be considered feminist psychology and liberation-psychology practices. Using a historical background, we focus on Portuguese social-political aspects including the feminist movement. Then, through a case study, we explore the grassroots movement Graal, whose projects were very influenced by the writings of Paulo Freire, on pedagogy of liberation. The concern with liberating oppressed groups is visible through the work of the Graal and shows the importance of collective action through conscientization.
Foreign accent syndrome as a first sign of multiple sclerosis
Authors: Chanson JB , Kremer S , Blanc F , Marescaux C , Namer IJ , de Seze J
Published: July 2009

Background

Foreign accent syndrome (FAS) consists of a speech rhythm disorder different from dysarthia or aphasia. It is unusually met in multiple sclerosis (MS).

Objective

We report a case of FAS as an initial symptom of a MS.

Methods

A right-handed French woman developed an isolated German foreign accent. Brain magnetic resonance imaging (MRI), SPECT and analysis of CSF were performed.

Results

Brain MRI revealed a large hypersignal on T2-weighted images in the left prerolandic white matter. Single photon emission computed tomography showed a right prerolandic hypoperfusion. Unmatched oligoclonal bands in cerebrospinal fluid and occurrence of new abnormal hypersignals on the following MRI led us to diagnose MS.

Conclusion

FAS may be the first symptom of MS. It could result from extensive disturbances of brain function involving the right hemisphere.
Extensive vasogenic edema of anti-aquaporin-4 antibody-related brain lesions
Authors: Matsushita T , Isobe N , Matsuoka T , Ishizu T , Kawano Y , Yoshiura T , Ohyagi Y , Kira J
Published: July 2009

Objective

Using neuroimaging, we analyzed the nature of extensive brain lesions in five anti-aquaporin-4 (AQP4) antibody-positive patients with neuromyelitis optica spectrum disorders.

Results

Extensive brain lesions involved white matter in three, and basal ganglia and corpus callosum in one each. Four patients showed high diffusivity on apparent diffusion coefficient maps and three demonstrated increased choline/creatine ratios and decreased N-acetyl-aspartate/creatine ratios on 1H-magnetic resonance spectroscopy. These findings suggested that the lesions were vasogenic edema associated with inflammation. Unusual brain symptoms associated with such lesions included recurrent limbic encephalitis, parkinsonism, and coma.

Conclusion

Anti-AQP4 antibody is considered to be associated with the neuroimaging appearances of vasogenic edema.
Multiple sclerosis risk: interaction between human leukocyte antigen and the environment in Sardinian population
Authors: Cocco E , Sardu C , Murru R , Frau J , Lorefice L , Mamusa E , Contu P , Marrosu MG
Published: July 2009

Background

The island of Sardinia features a high incidence of multiple sclerosis (MS) characterized by early age at onset and a progressively increasing trend. The current study was aimed at examining variations in human leukocyte antigen–risk genotypes occurring over time in a cohort of patients.

Methods

Susceptible and neutral DRB1-DQB1 genotypes were identified in 1660 patients. Age at onset was established in 1436 patients divided into two cohorts, an older cohort (subjects born before 1949, N = 233) and a younger one (subjects born from 1960 to 1989, N = 850). Patients from the older cohort were randomly assigned to patients of the same sex from the younger cohort, matched for age at onset. The final sample included 170 pairs. Logistic conditional analysis was performed to determine the probability of a neutral genotype in both cohorts. Kaplan–Meier analysis was applied to ascertain the influence of predisposing and neutral genotypes in age at onset for both cohorts.

Findings

The probability of carrying a neutral genotype was 1.76-fold higher in the younger than in the older cohort ( P = 0.02) and 3.67-fold higher in men ( P = 0.005). Kaplan–Meier analysis revealed an earlier age at onset in patients of the young cohort carrying the predisposing genotype ( P = 0.004).

Interpretation

In the Sardinian population, an environment more prone and propitious to autoimmunity may contribute toward the rising incidence of MS or anticipate overt manifestation of the disease in genetically predisposed subjects.
Heel Pain in the Athlete
Authors: Hunt Kenneth John , Anderson Robert B.
Published: July 2009

Context:

Heel pain, a relatively common problem in the athlete, can present a diagnostic and therapeutic dilemma. The purpose of this article is to review treatment techniques for common causes of heel pain in the athlete.

Evidence Acquisition:

Articles in the English literature through August 2008 were selected and reviewed in the context of the management of heel pain in the athlete. Clinical and surgical photographs are presented as an illustration of preferred techniques and pertinent pathologic findings.

Results:

Although nonoperative treatment remains the mainstay for most painful heel pathologies, a number of surgical interventions have shown encouraging results in carefully selected patients.

Conclusions:

The management of heel pain in the athlete requires diagnostic skill, appropriate imaging evaluation, and a careful, initially conservative approach to treatment. Surgical treatment can be successful in carefully selected patients.
YA is needed for proper nuclear organization to transition between meiosis and mitosis in Drosophila
Authors: Sackton Katharine L , Lopez Jacqueline M , Berman Cindy L , Wolfner Mariana F
Published: July 2009

Background

The Drosophila YA protein is required to initiate the embryonic cleavage divisions. After egg activation, YA enters nuclei and interacts with chromatin and the nuclear lamina. This study was designed to define more precisely the events prior to the first cleavage division that are dependent upon YA.

Results

We find that meiosis is completed normally in the absence of YA function. The first defects in embryos and eggs from mutant mothers first appear just after the completion of meiosis, and are seen as abnormal associations among the resultant haploid nuclei. These defects are associated with asynchronies in the cell cycle-dependent chromatin condensation state of the haploid nuclei. However, we find evidence of DNA replication in the absence of YA function.

Conclusion

Our data suggest YA function is needed at a control point, following meiosis II and the initiation of the first postmeiotic S phase, which is sensitive to the chromatin condensation state of the haploid meiotic products.
Proteins involved in difference of sorbitol fermentation rates of the toxigenic and nontoxigenic Vibrio choleraeEl Tor strains revealed by comparative proteome analysis
Authors: Wang Ruibai , Zhang Hongzhi , Qiu Haiyan , Gao Shouyi , Kan Biao
Published: July 2009

Background

The nontoxigenic V. cholerae El Tor strains ferment sorbitol faster than the toxigenic strains, hence fast-fermenting and slow-fermenting strains are defined by sorbitol fermentation test. This test has been used for more than 40 years in cholera surveillance and strain analysis in China. Understanding of the mechanisms of sorbitol metabolism of the toxigenic and nontoxigenic strains may help to explore the genome and metabolism divergence in these strains. Here we used comparative proteomic analysis to find the proteins which may be involved in such metabolic difference.

Results

We found the production of formate and lactic acid in the sorbitol fermentation medium of the nontoxigenic strain was earlier than of the toxigenic strain. We compared the protein expression profiles of the toxigenic strain N16961 and nontoxigenic strain JS32 cultured in sorbitol fermentation medium, by using fructose fermentation medium as the control. Seventy-three differential protein spots were found and further identified by MALDI-MS. The difference of product of fructose-specific IIA/FPR component gene and mannitol-1-P dehydrogenase, may be involved in the difference of sorbitol transportation and dehydrogenation in the sorbitol fast- and slow-fermenting strains. The difference of the relative transcription levels of pyruvate formate-lyase to pyruvate dehydrogenase between the toxigenic and nontoxigenic strains may be also responsible for the time and ability difference of formate production between these strains.

Conclusion

Multiple factors involved in different metabolism steps may affect the sorbitol fermentation in the toxigenic and nontoxigenic strains of V. cholerae El Tor.