bluuebunny/crossref_metadata_2025 huggingface dataset:
Acylcarnitines activate proinflammatory signaling pathways
Authors: Rutkowsky Jennifer M. , Knotts Trina A. , Ono-Moore Kikumi D. , McCoin Colin S. , Huang Shurong , Schneider Dina , Singh Shamsher , Adams Sean H. , Hwang Daniel H.
Published: April 2014

Incomplete β-oxidation of fatty acids in mitochondria is a feature of insulin resistance and type 2 diabetes mellitus (T2DM). Previous studies revealed that plasma concentrations of medium- and long-chain acylcarnitines (by-products of incomplete β-oxidation) are elevated in T2DM and insulin resistance. In a previous study, we reported that mixed d,l isomers of C12- or C14-carnitine induced an NF-κB-luciferase reporter gene in RAW 264.7 cells, suggesting potential activation of proinflammatory pathways. Here, we determined whether the physiologically relevant l-acylcarnitines activate classical proinflammatory signaling pathways and if these outcomes involve pattern recognition receptor (PRR)-associated pathways. Acylcarnitines induced the expression of cyclooxygenase-2 in a chain length-dependent manner in RAW 264.7 cells. l-C14 carnitine (5–25 μM), used as a representative acylcarnitine, stimulated the expression and secretion of proinflammatory cytokines in a dose-dependent manner. Furthermore, l-C14 carnitine induced phosphorylation of JNK and ERK, common downstream components of many proinflammatory signaling pathways including PRRs. Knockdown of MyD88, a key cofactor in PRR signaling and inflammation, blunted the proinflammatory effects of acylcarnitine. While these results point to potential involvement of PRRs, l-C14 carnitine promoted IL-8 secretion from human epithelial cells (HCT-116) lacking Toll-like receptors (TLR)2 and -4, and did not activate reporter constructs in TLR overexpression cell models. Thus, acylcarnitines have the potential to activate inflammation, but the specific molecular and tissue target(s) involved remain to be identified.
Regulation of the chemosensory control of breathing by Kölliker-Fuse neurons
Authors: Damasceno Rosélia S. , Takakura Ana C. , Moreira Thiago S.
Published: April 2014

The Kölliker-Fuse region (KF) and the lateral parabrachial nucleus (LPBN) have been implicated in the maintenance of cardiorespiratory control. Here, we evaluated the involvement of the KF region and the LPBN in cardiorespiratory responses elicited by chemoreceptor activation in unanesthetized rats. Male Wistar rats (280–330 g; n = 5–9/group) with bilateral stainless-steel guide cannulas implanted in the KF region or the LPBN were used. Injection of muscimol (100 and 200 pmol/100 nl) in the KF region decreased resting ventilation (1,140 ± 68 and 978 ± 100 vs. saline: 1,436 ± 155 ml·kg−1·min−1), without changing mean arterial pressure (MAP) and heart rate (HR). Bilateral injection of the GABA-A antagonist bicuculline (1 nmol/100 nl) in the KF blocked the inhibitory effect on ventilation (1,418 ± 138 vs. muscimol: 978 ± 100 ml·kg−1·min−1) elicited by muscimol. Muscimol injection in the KF reduced the increase in ventilation produced by hypoxia (8% O2) (1,827 ± 61 vs. saline: 3,179 ± 325 ml·kg−1·min−1) or hypercapnia (7% CO2) (1,488 ± 277 vs. saline: 3,539 ± 374 ml·kg−1·min−1) in unanesthetized rats. Bilateral injection of bicuculline in the KF blocked the decrease in ventilation produced by muscimol in the KF during peripheral or central chemoreflex activation. Bilateral injection of muscimol in the LPBN did not change resting ventilation or the increase in ventilation elicited by hypoxia or hypercapnia. The results of the present study suggest that the KF region, but not the LPBN, has mechanisms to control ventilation in resting, hypoxic, or hypercapnic conditions in unanesthetized rats.
Circulating bilirubin and defense against kidney disease and cardiovascular mortality: mechanisms contributing to protection in clinical investigations
Authors: Boon Ai-Ching , Bulmer Andrew C. , Coombes Jeff S. , Fassett Robert G.
Published: April 2014

Unconjugated bilirubin is an endogenous circulating antioxidant, bound to albumin, and therefore is retained in the vascular compartment. Bilirubin has well-documented neurotoxic effects in infants; however, current evidence indicates mildly elevated bilirubin is associated with protection from cardiovascular disease and all-cause mortality in adults. Recent clinical studies show mildly elevated bilirubin is associated with protection from kidney damage and dysfunction, in addition to cardiovascular events and all-cause mortality in patients undergoing hemodialysis. This is the first review to examine the clinical evidence and summarize the potential mechanisms of action that link bilirubin to protection from kidney damage, subsequent kidney failure, and dialysis-related mortality. With this understanding, it is hoped that new therapies will be developed to prevent renal dysfunction and mortality from cardiovascular disease in at-risk individuals.
NADPH oxidase-derived reactive oxygen species contribute to impaired cutaneous microvascular function in chronic kidney disease
Authors: DuPont Jennifer J. , Ramick Meghan G. , Farquhar William B. , Townsend Raymond R. , Edwards David G.
Published: April 2014

Oxidative stress promotes vascular dysfunction in chronic kidney disease (CKD). We utilized the cutaneous circulation to test the hypothesis that reactive oxygen species derived from NADPH oxidase and xanthine oxidase impair nitric oxide (NO)-dependent cutaneous vasodilation in CKD. Twenty subjects, 10 stage 3 and 4 patients with CKD (61 ± 4 yr; 5 men/5 women; eGFR: 39 ± 4 ml·min−1·1.73 m−2) and 10 healthy controls (55 ± 2 yr; 4 men/6 women; eGFR: >60 ml·min−1·1.73 m−2) were instrumented with 4 intradermal microdialysis fibers for the delivery of 1) Ringer solution (Control), 2) 10 μM tempol (scavenge superoxide), 3) 100 μM apocynin (NAD(P)H oxidase inhibition), and 4) 10 μM allopurinol (xanthine oxidase inhibition). Skin blood flow was measured via laser-Doppler flowmetry during standardized local heating (42°C). Ng-nitro-l-arginine methyl ester (l-NAME; 10 mM) was infused to quantify the NO-dependent portion of the response. Cutaneous vascular conductance (CVC) was calculated as a percentage of the maximum CVC achieved during sodium nitroprusside infusion at 43°C. Cutaneous vasodilation was attenuated in patients with CKD (77 ± 3 vs. 88 ± 3%, P = 0.01), but augmented with tempol and apocynin (tempol: 88 ± 2 ( P = 0.03), apocynin: 91 ± 2% ( P = 0.001). The NO-dependent portion of the response was reduced in patients with CKD (41 ± 4 vs. 58 ± 2%, P = 0.04), but improved with tempol and apocynin (tempol: 58 ± 3 ( P = 0.03), apocynin: 58 ± 4% ( P = 0.03). Inhibition of xanthine oxidase did not alter cutaneous vasodilation in either group ( P > 0.05). These data suggest that NAD(P)H oxidase is a source of reactive oxygen species and contributes to microvascular dysfunction in patients with CKD.
Competitive inhibition of SGLT2 by tofogliflozin or phlorizin induces urinary glucose excretion through extending splay in cynomolgus monkeys
Authors: Nagata Takumi , Suzuki Masayuki , Fukazawa Masanori , Honda Kiyofumi , Yamane Mizuki , Yoshida Ayae , Azabu Hiroko , Kitamura Hidekazu , Toyota Naoto , Suzuki Yoshiyuki , Kawabe Yoshiki
Published: April 2014

Sodium-glucose cotransporter 2 (SGLT2) inhibitors showed a glucose lowering effect in type 2 diabetes patients through inducing renal glucose excretion. Detailed analysis of the mechanism of the glucosuric effect of SGLT2 inhibition, however, has been hampered by limitations of clinical study. Here, we investigated the mechanism of urinary glucose excretion using nonhuman primates with SGLT inhibitors tofogliflozin and phlorizin, both in vitro and in vivo. In cells overexpressing cynomolgus monkey SGLT2 (cSGLT2), both tofogliflozin and phlorizin competitively inhibited uptake of the substrate (α-methyl-d-glucopyranoside; AMG). Tofogliflozin was found to be a selective cSGLT2 inhibitor, inhibiting cSGLT2 more strongly than did phlorizin, with selectivity toward cSGLT2 1,000 times that toward cSGLT1; phlorizin was found to be a nonselective cSGLT1/2 inhibitor. In a glucose titration study in cynomolgus monkeys under conditions of controlled plasma drug concentration, both tofogliflozin and phlorizin increased fractional excretion of glucose (FEG) by up to 50% under hyperglycemic conditions. By fitting the titration curve using a newly introduced method that avoids variability in estimating the threshold of renal glucose excretion, we found that tofogliflozin and phlorizin lowered the threshold and extended the splay in a dose-dependent manner without significantly affecting the tubular transport maximum for glucose (TmG). Our results demonstrate the contribution of SGLT2 to renal glucose reabsorption (RGR) in cynomolgus monkeys and demonstrate that competitive inhibition of cSGLT2 exerts a glucosuric effect by mainly extending splay and lowering threshold without affecting TmG.
Neutral aminoaciduria in cystathionine β-synthase-deficient mice, an animal model of homocystinuria
Authors: Akahoshi Noriyuki , Kamata Shotaro , Kubota Masashi , Hishiki Takako , Nagahata Yoshiko , Matsuura Tomomi , Yamazaki Chiho , Yoshida Yuka , Yamada Hidenori , Ishizaki Yasuki , Suematsu Makoto , Kasahara Tadashi , Ishii Isao
Published: April 2014

The kidney is one of the major loci for the expression of cystathionine β-synthase (CBS) and cystathionine γ-lyase (CTH). While CBS-deficient ( Cbs−/−) mice display homocysteinemia/methioninemia and severe growth retardation, and rarely survive beyond the first 4 wk, CTH-deficient ( Cth−/−) mice show homocysteinemia/cystathioninemia but develop with no apparent abnormality. This study examined renal amino acid reabsorption in those mice. Although both 2-wk-old Cbs−/−and Cth−/−mice had normal renal architecture, their serum/urinary amino acid profiles largely differed from wild-type mice. The most striking feature was marked accumulation of Met and cystathionine in serum/urine/kidney samples of Cbs−/−and Cth−/−mice, respectively. Levels of some neutral amino acids (Val, Leu, Ile, and Tyr) that were not elevated in Cbs−/−serum were highly elevated in Cbs−/−urine, and urinary excretion of other neutral amino acids (except Met) was much higher than expected from their serum levels, demonstrating neutral aminoaciduria in Cbs−/−(not Cth−/−) mice. Because the bulk of neutral amino acids is absorbed via a B0AT1 transporter and Met has the highest substrate affinity for B0AT1 than other neutral amino acids, hypermethioninemia may cause hyperexcretion of neutral amino acids.
Development of dendritic tonic GABAergic inhibition regulates excitability and plasticity in CA1 pyramidal neurons
Authors: Groen Martine R. , Paulsen Ole , Pérez-Garci Enrique , Nevian Thomas , Wortel J. , Dekker Marinus P. , Mansvelder Huibert D. , van Ooyen Arjen , Meredith Rhiannon M.
Published: April 2014

Synaptic plasticity rules change during development: while hippocampal synapses can be potentiated by a single action potential pairing protocol in young neurons, mature neurons require burst firing to induce synaptic potentiation. An essential component for spike timing-dependent plasticity is the backpropagating action potential (BAP). BAP along the dendrites can be modulated by morphology and ion channel composition, both of which change during late postnatal development. However, it is unclear whether these dendritic changes can explain the developmental changes in synaptic plasticity induction rules. Here, we show that tonic GABAergic inhibition regulates dendritic action potential backpropagation in adolescent, but not preadolescent, CA1 pyramidal neurons. These developmental changes in tonic inhibition also altered the induction threshold for spike timing-dependent plasticity in adolescent neurons. This GABAergic regulatory effect on backpropagation is restricted to distal regions of apical dendrites (>200 μm) and mediated by α5-containing GABA(A) receptors. Direct dendritic recordings demonstrate α5-mediated tonic GABA(A) currents in adolescent neurons which can modulate BAPs. These developmental modulations in dendritic excitability could not be explained by concurrent changes in dendritic morphology. To explain our data, model simulations propose a distally increasing or localized distal expression of dendritic α5 tonic inhibition in mature neurons. Overall, our results demonstrate that dendritic integration and plasticity in more mature dendrites are significantly altered by tonic α5 inhibition in a dendritic region-specific and developmentally regulated manner.
Activity of fixation neurons in the monkey frontal eye field during smooth pursuit eye movements
Authors: Izawa Yoshiko , Suzuki Hisao
Published: April 2014

We recorded the activity of fixation neurons in the frontal eye field (FEF) in trained monkeys and analyzed their activity during smooth pursuit eye movements. Fixation neurons were densely located in the area of the FEF in the caudal part of the arcuate gyrus facing the inferior arcuate sulcus where focal electrical stimulation suppressed the generation of saccades and smooth pursuit in bilateral directions at an intensity lower than the threshold for eliciting electrically evoked saccades. Whereas fixation neurons discharged tonically during fixation, they showed a variety of discharge patterns during smooth pursuit, ranging from a decrease in activity to an increase in activity. Of these, more than two-thirds were found to show a reduction in activity during smooth pursuit in the ipsilateral and bilateral directions. The reduction in activity of fixation neurons began at pursuit initiation and continued during pursuit maintenance. When catch-up saccades during the initiation of pursuit were eliminated by a step-ramp target routine, the reduced activity of fixation neurons remained. The reduction in activity during pursuit was not dependent on the activity during fixation without a target. Based on these results, we discuss the role of the FEF at maintaining fixation in relation to various other brain areas. We suggest that fixation neurons in the FEF contribute to the suppression of smooth pursuit. These results suggest that FEF fixation neurons are part of a more generalized visual fixation system through which suppressive control is exerted on smooth pursuit, as well as saccades.
A Unified Model Considering Effects of Droplet Break‐Up and Air Entrainment at the Initial Stage of Fuel Spray Penetration
Authors: Jafarmadar S. , Jalilpour B. , Ganji D. D. , Taghavifar H.
Published: April 2014

This paper proposes a new unified single model that considers droplet break‐up and air entrainment impact on three flow regimes (namely, Stokes, Allen, and Newton) in the initial stage of fuel spray penetration. Homotopy perturbation method was used to obtain semianalytical solutions of unified single model on diesel fuel’s spray penetration when the influence of air entrainment is small (up to 0.1‐0.2 ms after the start of injection). It is demonstrated that the applied analytical method is very straightforward in comparison with existing techniques. Furthermore, it is decidedly effectual in terms of accuracy and rapid convergence. The formulation of the problem is presented in the text as well as the analytical and numerical procedures.
Transient Stability Improvement for Combined Heat and Power System Using Load Shedding
Authors: Chen Hung-Cheng , Chang Long-Yi , Shang Li-Qun
Published: April 2014

The purpose of the paper is to analyze and improve the transient stability of an industrial combined heat and power (CHP) system in a high‐tech science park in Taiwan. The CHP system installed two 161 kV/161 kV high‐impendence transformers to connect with Taipower System (TPS) for both decreasing the short‐circuit fault current and increasing the fault critical clearing time. The transient stabilities of three types of operation modes in CHP units, 3G1S, 2G1S, and 1G1S, are analyzed. Under the 3G1S operation mode, the system frequency is immediately restored to 60 Hz after tie line tripping with the TPS. Under the 1G1S and 2G1S operation modes, the system frequencies will continuously decrease and eventually become unstable. A novel transient stability improvement approach using load shedding technique based on the change in frequency is proposed to improve the transient stability.
Financial Time Series Forecasting Using Directed‐Weighted Chunking SVMs
Authors: Cai Yongming , Song Lei , Wang Tingwei , Chang Qing
Published: April 2014

Support vector machines (SVMs) are a promising alternative to traditional regression estimation approaches. But, when dealing with massive‐scale data set, there exist many problems, such as the long training time and excessive demand of memory space. So, the SVMs algorithm is not suitable to deal with financial time series data. In order to solve these problems, directed‐weighted chunking SVMs algorithm is proposed. In this algorithm, the whole training data set is split into several chunks, and then the support vectors are obtained on each subset. Furthermore, the weighted support vector regressions are calculated to obtain the forecast model on the new working data set. Our directed‐weighted chunking algorithm provides a new method of support vectors decomposing and combining according to the importance of chunks, which can improve the operation speed without reducing prediction accuracy. Finally, IBM stock daily close prices data are used to verify the validity of the proposed algorithm.
Performance Analysis of Short Journal Bearing under Thin Film Lubrication
Authors: Soni Sandeep , Vakharia D. P.
Published: April 2014

The steady state performance analysis of short circular journal bearing is conducted using the viscosity correction model under thin film lubrication conditions. The thickness of adsorbed molecular layers is the most critical factor in studying thin film lubrication, and is the most essential parameter that distinguishes thin film from thick film lubrication analysis. The interaction between the lubricant and the surface within a very narrow gap has been considered. The general Reynolds equation has been derived for calculating thin film lubrication parameters affecting the performance of short circular journal bearing. Investigation for the load carrying capacity, friction force, torque, and power loss for the short circular journal bearing under the consideration of adsorbed layer thickness (2δ) has been carried out. The analysis is carried out for the short bearing approximation (L/D=0.5) using Gumbel’s boundary condition. It has been found that the steady state performance parameters are comparatively higher for short circular journal bearing under the consideration of adsorbed layer thickness than for plain circular journal bearing. The load carrying capability of adsorbed layer thickness considered bearing is observed to be high for the specified operating conditions. This work could promote the understanding and research for the mechanism of the nanoscale thin film lubrication.
Microstructure Changes of Ti‐Al‐C Films Deposited by Filtered Cathodic Vacuum Arc
Authors: Pang Xianjuan , Liu Xiaoqiang , Jin Bo
Published: April 2014

Nanocomposite Ti‐Al‐C films were deposited by filtered cathodic vacuum arc (FCVA) at different CH4 flows. The deposited films were characterized in terms of elemental and phase compositions, chemical bonds, and texture as a function of CH4 flow rate by XRD, XPS, HRTEM, Raman spectroscopy, and IR spectroscopy. The results show that the TiC grain size decreases from 4.2 to 2.9 nm as the CH4 flow rate increases from 30 to 80 sccm. The analysis of XPS, HRTEM, and Raman spectroscopy shows that the microstructure of deposited films turns from a TiC dominant TiC‐C film to a carbon network dominant TiAl‐doped a‐C film structure as the CH4 flow increases from 30 sccm to 80 sccm. IR spectroscopy shows that most of the hydrogen atoms in the deposited films are bonded to the sp3‐hybridized C atoms. All the composition and microstructure change can be explained by considering the plasma conditions and the effect of CH4 flow.
On Homoclinic Solutions for First-Order Superquadratic Hamiltonian Systems with Spectrum Point Zero
Authors: Li Feng , Sun Juntao
Published: April 2014

The existence and multiplicity of homoclinic solutions for a class of first-order periodic Hamiltonian systems with spectrum point zero are obtained. The proof is based on two critical point theorems for strongly indefinite functionals. Some recent results are improved and extended.
Sparse-View Ultrasound Diffraction Tomography Using Compressed Sensing with Nonuniform FFT
Authors: Hua Shaoyan , Ding Mingyue , Yuchi Ming
Published: April 2014

Accurate reconstruction of the object from sparse-view sampling data is an appealing issue for ultrasound diffraction tomography (UDT). In this paper, we present a reconstruction method based on compressed sensing framework for sparse-view UDT. Due to the piecewise uniform characteristics of anatomy structures, the total variation is introduced into the cost function to find a more faithful sparse representation of the object. The inverse problem of UDT is iteratively resolved by conjugate gradient with nonuniform fast Fourier transform. Simulation results show the effectiveness of the proposed method that the main characteristics of the object can be properly presented with only 16 views. Compared to interpolation and multiband method, the proposed method can provide higher resolution and lower artifacts with the same view number. The robustness to noise and the computation complexity are also discussed.
Application of Firefly Algorithm in Voltage Stability Environment Incorporating Circuit Element Model of SSSC with Variable Susceptance Model of SVC
Authors: Jebaraj Luke , Christober Asir Rajan Charles , Sriram Kumar
Published: April 2014

This paper proposes an application of firefly algorithm (FA) based extended voltage stability margin and minimization of active (or) real power loss incorporating Series-Shunt flexible AC transmission system (FACTS) controller named as static synchronous series compensator (SSSC) combined with static var compensator (SVC). A circuit model of SSSC and variable susceptance model of SVC are utilized to control the line power flows and bus voltage magnitudes, respectively, for real power loss minimization and voltage stability limit improvement. The line quality proximity index (LQP) is used to assess the voltage stability of a power system. The values of voltage profile improvement, real power loss minimization, and the location and size of FACTS devices were optimized by FA. The results are obtained from the IEEE 14- and 30-bus test case systems under different operating conditions and compared with other leading evolutionary techniques such as shuffled frog leaping algorithm (SFLA), differential evolution (DE) and particle swarm optimization (PSO).
Robust Switched Predictive Braking Control for Rollover Prevention in Wheeled Vehicles
Authors: Rodríguez Licea Martín Antonio , Cervantes Ilse
Published: April 2014

The aim of this paper is to propose a differential braking rollover mitigation strategy for wheeled vehicles. The strategy makes use of a polytopic (piecewise linear) description of the vehicle and includes translational and rotational dynamics, as well as suspension effects. The braking controller is robust and the system states are predicted to estimate the rollover risk up to a given time horizon. In contrast to existing works, the switched predictive nature of the control allows it to be applied only when risk of rollover is foreseen, interfering a minimum with driver’s actions. The stability of the strategy is analyzed and its robustness is illustrated via numerical simulations using CarSim for a variety of vehicles.
Pricing of Equity Indexed Annuity under Fractional Brownian Motion Model
Authors: Xu Lin , Shen Guangjun , Yao Dingjun
Published: April 2014

Fractional Brownian motion with Hurst exponentH∈(1/2,1)is a good candidate for modeling financial time series with long-range dependence and self-similarity. The main purpose of this paper is to address the valuation of equity indexed annuity (EIA) designs under the market driven by fractional Brownian motion. As a result, this paper presents an explicit pricing expression for point-to-point EIA design and bounds for the pricing of high-water-marked EIA design. Some numerical examples are given to illustrate the impact of the parameters involved in the pricing problems.
A Novel Approach to the Fabrication of CdSe Quantum Dots in Aqueous Solution: Procedures for Controlling Size, Fluorescence Intensity, and Stability over Time
Authors: Almendral-Parra M. J. , Alonso-Mateos A. , Boyero-Benito J. F. , Sánchez-Paradinas S. , Rodríguez-Fernández E.
Published: April 2014

This paper report a straightforward approach for the synthesis of CdSe quantum dots (CdSe QDs) in aqueous solution. This method, performed in homogeneous phase, affords optimal sizes and high quantum yields for each application desired. It is an a la carte procedure for the synthesis of nanoparticles aimed at their later application. By controlling the experimental conditions, CdSe QDs of sizes ranging between 2 and 6 nm can be obtained. The best results were achieved in an ice‐bath thermostated at 4°C, using mercaptoacetic acid as dispersant. Under these conditions, a slow growth of quantum nanocrystals was generated and this was controlled kinetically by the hydrolysis of to generate Se2−   in situ, one of the forming species of the nanocrystal. The organic dispersant mercaptoacetate covalently binds to the Cd2+ ion, modifying the diffusion rate of the cation, and plays a key role in the stabilization of CdSe QDs. In optimum conditions, when kept in their own solution CdSe QDs remain dispersed over 4 months. The NPs obtained under optimal conditions show high fluorescence, which is a great advantage as regards their applications. The quantum efficiency is also high, owing to the formation under certain conditions of a nanoshell of Cd(OH)2, values of 60% being reached.
Damp‐Heat Induced Performance Degradation for InGaP/GaAs/Ge Triple‐Junction Solar Cell
Authors: Hong Hwen-Fen , Huang Tsung-Shiew , Uen Wu-Yih , Chen Yen-Yeh
Published: April 2014

We performed accelerated tests on sealed and nonsealed InGaP/InGaAs/Ge triple‐junction (TJ) solar cells in a complex high temperature and high humidity environment and investigated the electrical properties over time. The degradation of energy conversion efficiency in nonsealed cells was found to be more serious than that in sealed cells. The short‐circuit current (ISC), open‐circuit voltage (VOC), and fill factor (FF) of sealed cells changed very slightly, though the conversion efficiency decreased 3.6% over 500 h of exposure. This decrease of conversion efficiency was suggested to be due to the deterioration of silicone encapsulant. The ISC, VOC, and FF of nonsealed cells decreased with increasing exposure time. By EL and SEM analysis, the root causes of degradation can be attributed to the damage and cracks near the edge of cells induced by the moisture ingress. It resulted in shunt paths that lead to a deterioration of the conversion efficiency of solar cell by increasing the leakage current, as well as decreasing open‐circuit voltage and fill factor of nonsealed solar cells.
On the Sumudu Transform and Its Extension to a Class of Boehmians
Authors: Al-Omari S. K. Q.
Published: April 2014

Boehmians are used for all objects obtained by an algebraic construction similar to that of the field of quotients. In literature, several integral transforms have been extended to various Boehmian spaces but a few to the space of strong Boehmians. As shown in the work of Al-Omari (2013), this work describes certain spaces of Boehmians. The Sumudu transform is therefore established and it is one-one and continuous in the space of Boehmians. The inverse transform is given and some results are also discussed.
Measuring Service Reliability Using Automatic Vehicle Location Data
Authors: Ma Zhenliang , Ferreira Luis , Mesbah Mahmoud
Published: April 2014

Bus service reliability has become a major concern for both operators and passengers. Buffer time measures are believed to be appropriate to approximate passengers′ experienced reliability in the context of departure planning. Two issues with regard to buffer time estimation are addressed, namely, performance disaggregation and capturing passengers’ perspectives on reliability. A Gaussian mixture models based method is applied to disaggregate the performance data. Based on the mixture models distribution, a reliability buffer time (RBT) measure is proposed from passengers’ perspective. A set of expected reliability buffer time measures is developed for operators by using different spatial‐temporal levels combinations of RBTs. The average and the latest trip duration measures are proposed for passengers that can be used to choose a service mode and determine the departure time. Using empirical data from the automatic vehicle location system in Brisbane, Australia, the existence of mixture service states is verified and the advantage of mixture distribution model in fitting travel time profile is demonstrated. Numerical experiments validate that the proposed reliability measure is capable of quantifying service reliability consistently, while the conventional ones may provide inconsistent results. Potential applications for operators and passengers are also illustrated, including reliability improvement and trip planning.
Experience of Preimplantation Genetic Diagnosis with HLA Matching at the University Hospital Virgen del Rocío in Spain: Technical and Clinical Overview
Authors: Fernández Raquel María , Peciña Ana , Lozano-Arana Maria Dolores , Sánchez Beatriz , Guardiola Jordi , García-Lozano Juan Carlos , Borrego Salud , Antiñolo Guillermo
Published: April 2014

Preimplantation genetic diagnosis (PGD) of genetic diseases, combined with HLA matching (PGD-HLA), is an option for couples at risk of transmitting a genetic disease to select unaffected embryos of an HLA tissue type compatible with that of an existing affected child. Here we present the results of our PGD-HLA program at the Department of Genetics, Reproduction and Fetal Medicine of the University Hospital Virgen del Rocío in Seville. Seven couples have participated in our program because of different indications. Overall, 26 cycles were performed, providing a total of 202 embryos. A conclusive molecular diagnosis and HLA-typing could be assured in 96% of the embryos. The percentage of transfers per cycle was 26.9% and the birth rate per cycle was 7.7% per transfer. Our PGD-HLA program resulted in the birth of 2 healthy babies, HLA-identical to their affected siblings, with successful subsequent haematopoietic stem cell (HSC) transplantations. Both HSC-transplanted children are currently doing well 48 and 21 months following transplantation, respectively. All the procedures, including HSCs umbilical cord transplantation, were performed in our hospital.
A Novel Discrete Global-Best Harmony Search Algorithm for Solving 0-1 Knapsack Problems
Authors: Xiang Wan-li , An Mei-qing , Li Yin-zhen , He Rui-chun , Zhang Jing-fang
Published: April 2014

In order to better solve discrete 0-1 knapsack problems, a novel global-best harmony search algorithm with binary coding, called DGHS, is proposed. First, an initialization based on a greedy mechanism is employed to improve the initial solution quality in DGHS. Next, we present a novel improvisation process based on intuitive cognition of improvising a new harmony, in which the best harmony of harmony memory (HM) is used to guide the searching direction of evolution during the process of memory consideration, or else a harmony is randomly chosen from HM and then a discrete genetic mutation is done with some probability during the phase of pitch adjustment. Third, a two-phase repair operator is employed to repair an infeasible harmony vector and to further improve a feasible solution. Last, a new selection scheme is applied to decide whether or not a new randomly generated harmony is included into the HM. The proposed DGHS is evaluated on twenty knapsack problems with different scales and compared with other three metaheuristics from the literature. The experimental results indicate that DGHS is efficient, effective, and robust for solving difficult 0-1 knapsack problems.
Robot Calibration for Cooperative Process under Typical Installation
Authors: Gan Yahui , Dai Xianzhong , Dong Donghui
Published: April 2014

A method with easy operation procedure and simple calibration condition is presented in this paper to solve the base frame calibration problem for cooperative robots. It is carried out through constructing a series of handclasp configurations and recording coordinates of the contact points, respectively, in base frame of each robot. Then the rotation matrix and translation matrix between base frame of cooperative robots can be calculated which is just the calibration result for cooperative robots. Based on typical installation mode for industrial robot, the floor mounted, wall mounted and ceiling mounted, constraints between base frames of these robots are further explored. These constraints are used to improve the calibration results for base frame calibration problem. In order to validate the correctness and effectiveness of our method, experiments on two industrial robots (Motoman VA1400 and HP20) are carried out at the end of the paper. The calibration errors are less than 8 mm in most cases, which satisfies the requirement of positioning accuracy for most industrial process, such as arc welding, transporting, and cutting. These experiment results assert the correctness of our method which can be used effectively to solve the base frame calibration problem for cooperative robots in manufacturing process.
Thickly Syndetical Sensitivity of Topological Dynamical System
Authors: Liu Heng , Liao Li , Wang Lidong
Published: April 2014

Consider the surjective continuous mapf:X→X, whereXis a compact metric space. In this paper we give several stronger versions of sensitivity, such as thick sensitivity, syndetic sensitivity, thickly syndetic sensitivity, and strong sensitivity. We establish the following. (1) If(X,f)is minimal and sensitive, then(X,f)is syndetically sensitive. (2) Weak mixing implies thick sensitivity. (3) If(X,f)is minimal and weakly mixing, then it is thickly syndetically sensitive. (4) If(X,f)is a nonminimalM-system, then it is thickly syndetically sensitive. Devaney chaos implies thickly periodic sensitivity. (5) We give a syndetically sensitive system which is not thickly sensitive. (6) We give thickly syndetically sensitive examples but not cofinitely sensitive ones.
Global Conservative and Multipeakon Conservative Solutions for the Modified Camassa‐Holm System with Coupling Effects
Authors: Wen Huabin , Wang Yujuan , Song Yongduan , Karimi Hamid Reza
Published: April 2014

This paper investigates the continuation of solutions to the modified coupled two‐component Camassa‐Holm system after wave breaking. The underlying problem is rather challenging due to the mutual coupling effect between two components in the system. By introducing a novel transformation that makes use of a skillfully defined characteristic and a set of newly defined variables, the original system is converted into a Lagrangian equivalent system, from which the global conservative solution is obtained, which further allows for the establishment of the multipeakon conservative solution of the system. The results obtained herein are deemed useful for understanding the inevitable phenomenon near wave breaking.
Improving Cytomegalovirus-Specific T Cell Reconstitution after Haploidentical Stem Cell Transplantation
Authors: Luo Xiao-Hua , Chang Ying-Jun , Huang Xiao-Jun
Published: April 2014

Cytomegalovirus (CMV) infection and delayed immune reconstitution (IR) remain serious obstacles for successful haploidentical stem cell transplantation (haplo-SCT). CMV-specific IR varied according to whether patients received manipulated/unmanipulated grafts or myeloablative/reduced intensity conditioning. CMV infection commonly occurs following impaired IR of T cell and its subsets. Here, we discuss the factors that influence IR based on currently available evidence. Adoptive transfer of donor T cells to improve CMV-specific IR is discussed. One should choose grafts from CMV-positive donors for transplant into CMV-positive recipients (D+/R+) because this will result in better IR than would grafts from CMV-negative donors (D−/R+). Stem cell source and donor age are other important factors. Posttransplant complications, including graft-versus-host disease and CMV infection, as well as their associated treatments, should also be considered. The effects of varying degrees of HLA disparity and conditioning regimens are more controversial. As many of these factors and strategies are considered in the setting of haplo-SCT, it is anticipated that haplo-SCT will continue to advance, further expanding our understanding of IR and CMV infection.
Hopf Bifurcation and Stability Analysis of a Congestion Control Model with Delay in Wireless Access Network
Authors: Zhao Wen-bo , Sun Xiao-ke , Wang Huicheng
Published: April 2014

We drive a scalar delay differential system to model the congestion of a wireless access network setting. The Hopf bifurcation of this system is investigated using the control and bifurcation theory; it is proved that there exists a critical value of delay for the stability. When the delay value passes through the critical value, the system loses its stability and a Hopf bifurcation occurs. Furthermore, the direction and stability of the bifurcating periodic solutions are derived by applying the normal form theory and the center manifold theorem. Finally, some examples and numerical simulations are presented to show the feasibility of the theoretical results.
A Global Optimization Approach for Solving Generalized Nonlinear Multiplicative Programming Problem
Authors: Yang Lin-Peng , Shen Pei-Ping , Pei Yong-Gang
Published: April 2014

This paper presents a global optimization algorithm for solving globally the generalized nonlinear multiplicative programming (MP) with a nonconvex constraint set. The algorithm uses a branch and bound scheme based on an equivalently reverse convex programming problem. As a result, in the computation procedure the main work is solving a series of linear programs that do not grow in size from iterations to iterations. Further several key strategies are proposed to enhance solution production, and some of them can be used to solve a general reverse convex programming problem. Numerical results show that the computational efficiency is improved obviously by using these strategies.
IDH1/IDH2but NotTP53Mutations Predict Prognosis in Bulgarian Glioblastoma Patients
Authors: Stancheva Gergana , Goranova Teodora , Laleva Maria , Kamenova Margarita , Mitkova Atanaska , Velinov Nikolay , Poptodorov George , Mitev Vanio , Kaneva Radka , Gabrovsky Nikolay
Published: April 2014

Mutations in genes encoding isocitrate dehydrogenase isoforms 1 (IDH1) and 2 (IDH2) have been associated with good prognosis for patients with brain neoplasias and have been commonly found together with mutatedTP53gene. To determine the prevalence ofIDH1,IDH2, andTP53mutations and their impact on overall survival 106 glioblastoma patients were analysed.IDH1mutations were detected in 13 andIDH2mutation in one patient. Two homozygous samples with R132H mutation inIDH1gene and a novel aberration K129R inIDH2gene were found. Sixty-four percent ofIDH1/IDH2mutated tumours harboured also a mutation inTP53gene. Genetic aberrations inTP53were present in 37 patients. Statistical analysis of the impact of the studied factors on the overall survival showed that the mutations inIDH1/IDH2, but not the ones inTP53, were associated with longer survival. Also, the impact of age on prognosis was confirmed. This is the first comprehensive study on glioblastomas in Bulgaria. Our results suggest thatIDH1/IDH2but notTP53mutations together with other prognostic factors such as age might be applied in clinical practice for prediction of outcome in patients with glioblastomas.
Traveling Waves in a Diffusive Predator-Prey Model Incorporating a Prey Refuge
Authors: Wu Xiujuan , Luo Yong , Hu Yizheng
Published: April 2014

We establish the existence of traveling wave solutions and small amplitude traveling wave train solutions for a reaction-diffusion system based on a predator-prey model incorporating a prey refuge. By using the shooting argument, invariant manifold theory, and the Hopf bifurcation theorem, we analyze the dynamic behavior of this model in the three-dimensional phase space. Numerical results are also presented to illustrate the theoretical results.
Animal Models of C-Reactive Protein
Authors: Torzewski Michael , Waqar Ahmed Bilal , Fan Jianglin
Published: April 2014

As the main theme of this special issue, CRP not only is an inflammatory marker but also has diverse biological functions associated with different diseases. To investigate CRP’s physiologies and their relationship with human pathological significance, it is essential to use appropriate animal models for translational research. The most popular models for the study of CRP are transgenic mice. However, researchers should be careful when extrapolating the findings derived from these animal models. This review will discuss the current concerns on CRP transgenic mice and rabbits.
On Some Geometric Properties of a New Paranormed Sequence Space
Authors: Karakaya Vatan , Altun Fatma
Published: April 2014

We introduce a new sequence space which is defined by the operatorW=(wnk)on the sequence spaceℓ(p). We define a modular functional on this space and investigate structure of this space equipped with Luxemburg norm. Also we study some geometric properties which are called Kadec-Klee, k-NUC, and uniform Opial properties and prove that this new space possesses these properties.
Trajectory Calculation as Forecasting Support Tool for Dust Storms
Authors: Al-Yahyai Sultan , Charabi Yassine
Published: April 2014

In arid and semiarid regions, dust storms are common during windy seasons. Strong wind can blow loose sand from the dry surface. The rising sand and dust is then transported to other places depending on the wind conditions (speed and direction) at different levels of the atmosphere. Considering dust as a moving object in space and time, trajectory calculation then can be used to determine the path it will follow. Trajectory calculation is used as a forecast supporting tool for both operational and research activities. Predefined dust sources can be identified and the trajectories can be precalculated from the Numerical Weather Prediction (NWP) forecast. In case of long distance transported dust, the tool should allow the operational forecaster to perform online trajectory calculation. This paper presents a case study for using trajectory calculation based on NWP models as a forecast supporting tool in Oman Meteorological Service during some dust storm events. Case study validation results showed a good agreement between the calculated trajectories and the real transport path of the dust storms and hence trajectory calculation can be used at operational centers for warning purposes.
Sufficient and Necessary Conditions for the Permanence of a Discrete Model with Beddington-DeAngelis Functional Response
Authors: Fan Yong-Hong , Wang Lin-Lin
Published: April 2014

We give a sufficient and necessary condition for the permanence of a discrete model with Beddington-DeAngelis functional response with the formx(n+1)=x(n)exp{a(n)-b(n)x(n)-c(n)y(n)/(α(n)+β(n)x(n)+γ(n)y(n))},y(n+1)=y(n)exp{-d(n)+f(n)x(n)/(α(n)+β(n)x(n)+γ(n)y(n))},wherea(n),b(n),c(n),d(n),f(n),α(n),β(n), andγ(n)are periodic sequences with the common periodω;b(n)is nonnegative;c(n),d(n),f(n),α(n),β(n), andγ(n)are positive. It is because of the difference between the comparison theorem for discrete system and its corresponding continuous system that an additional condition should be considered. In addition, through some analysis on the limit case of this system, we find that the sequenceα(n)has great influence on the permanence.
Unavailability Analysis for k‐out‐of‐n:G Systems with Multiple Failure Modes Based on Micro‐Markov Models
Authors: Tang Shengjin , Guo Xiaosong , Sun Xiaoyan , Xue Haijian , Zhou Zhaofa
Published: April 2014

Markov models are commonly used for unavailability analysis of redundant systems. However, due to the exploding states of Markov models for redundant systems, the states need to be merged to simplify the computation, which is called micro‐Markov models. However, how to derive the failure rates and repair rates of the newly developed micro‐Markov models has not been studied thoroughly. Therefore, this paper proposes detailed explanations and rules to derive the static unavailability by the micro‐Markov models for the k‐out‐of‐n:G systems with multiple failure modes. Firstly, two properties about applying the Markov models to the repairable system with independent multiple failure modes are presented. Based on these two properties, two rules are proposed for implementing the micro‐Markov models. The micro‐Markov models provide the exact same results for the repairable k‐out‐of‐n:G system with multiple independent failure modes and repair mechanisms and approximate results for systems with multiple hybrid failure modes. A case study of safety integrity verification for safety instrumented systems is provided to illustrate the application of the proposed method. The conceptual comparison and numerical examples demonstrate the reasonability and usefulness of the proposed micro‐Markov models.
A Novel Classification Approach through Integration of Rough Sets and Back-Propagation Neural Network
Authors: Si Lei , Liu Xin-hua , Tan Chao , Wang Zhong-bin
Published: April 2014

Classification is an important theme in data mining. Rough sets and neural networks are the most common techniques applied in data mining problems. In order to extract useful knowledge and classify ambiguous patterns effectively, this paper presented a hybrid algorithm based on the integration of rough sets and BP neural network to construct a novel classification system. The attribution values were discretized through PSO algorithm firstly to establish a decision table. The attribution reduction algorithm and rules extraction method based on rough sets were proposed, and the flowchart of proposed approach was designed. Finally, a prototype system was developed and some simulation examples were carried out. Simulation results indicated that the proposed approach was feasible and accurate and was outperforming others.
Design and Analysis of a Wire-Driven Parallel Mechanism for Low-Gravity Environment Simulation
Authors: Wang Weifang , Tang Xiaoqiang , Shao Zhufeng , Yang Jiping , Yi Wangmin
Published: April 2014

Traditional simulation mechanisms are unable to meet the simulation requirements of spacecraft launcher in low-gravity environment, like in the Moon. Based on the advantages of wire-driven parallel mechanism, a 6-DOF low-gravity environment simulation device with eight wires is designed in this paper. Firstly, the configuration and dimensional design of this wire-driven parallel mechanism are carried out. To operate and control the wire-driven parallel mechanism, a force distribution algorithm is introduced and the workspace is analyzed. Then, an evaluation index named quality index is established in order to study the performance of the wire-driven parallel manipulator in its workspace and reasonable tension is obtained after analyzing the influence on quality index caused by different wire tension.