bluuebunny/crossref_metadata_2025 huggingface dataset:
HANDLING RESOURCE SHARING PROBLEM USING PROPERTY-PRESERVING PLACE FUSIONS OF PETRI NETS
Authors: JIAO LI , HUANG HEJIAO , CHEUNG TO-YAT
Published: January 2009

Resource sharing is a very complex task in system design because it may induce undesirable properties such as deadlocks and overflows. This paper proposes a method for handling this task. Resource sharing is formulated as a place fusion on a Petri net specification that satisfies a designated set of properties and includes some duplicated places representing accesses to the resources. If this fusion satisfies some conditions, the obtained net will preserve the original properties after the incorporation of resource sharing. This paper considers two classes of property-preserving place fusions. Each class specifies the Petri net type to be used, the structural relationship among the resource places and possibly some additional conditions for the place fusion to preserve a designated set of properties. As an illustration, these place fusion approaches are applied to solve a resource sharing problem in the design of manufacturing systems.
NEW Z-DOMAIN CONTINUED FRACTION EXPANSIONS BASED ON AN INFINITE NUMBER OF MIRROR-IMAGE AND ANTI-MIRROR-IMAGE POLYNOMIAL DECOMPOSITIONS
Authors: RAMACHANDRAN V. , RAMACHANDRAN RAVI P. , GARGOUR C. S.
Published: January 2009

A magnitude response preserving modification of the denominator polynomial of a causal and stable digital transfer function leads to an infinite number of decompositions into a mirror-image polynomial (MIP) and an anti-mirror-image polynomial (AMIP). Properties and identifications of the MIP and AMIP are given. The identifications of Schussler and Davis, and the line spectral frequency formulation are special cases of the general MIP and AMIP decompositions introduced in this paper. Two types of Discrete Reactance Functions (DRF) are constructed. From these DRFs, five new continued fraction expansions (CFE) are developed, and some properties are obtained.
SIMPLE STRUCTURES FOR UNIMODULAR FILTER BANKS WITH REGULARITY
Authors: VIJAYAKUMAR ASHA , ABHILASH G.
Published: January 2009

In this paper we propose two new parameterizations for unimodular filter banks (UMFBs) by exploiting the canonical forms of the nilpotent matrix present in the factorization of UMFBs. A judicious choice of the canonical structure leads to simple implementation. The use of Discrete Walsh Hadamard Transform (DWHT) saves a major amount of multiplication. The presence of the nilpotent matrix also facilitates the design of filter banks with unequal length analysis and synthesis filters. The structures ensure perfect reconstruction (PR) with minimal delay in the McMillan sense. The free parameters can be obtained through unconstrained optimization, which is hardly possible with the existing design methods. Design examples are presented based on the proposed structures. Although there is a significant reduction in the number of free parameters, the performances of these structures are found to be comparable with and better than the existing design techniques for UMFBs. The design of a class of decomposable higher order UMFBs with unequal lengths of analysis and synthesis filters is done. Also, the design of a one-regular filter bank based on the simplest structure proposed is presented.
ON NONLINEAR OSCILLATOR DESIGN
Authors: ACHO LEONARDO
Published: January 2009

The objective of this short report is to present an intuitive methodology on second-order dynamic oscillator design based on divergence and curl vectorial calculus operations.
A FAST AND EFFECTIVE TIMING-DRIVEN PLACEMENT TOOL FOR FPGAs
Authors: KHALID MOHAMMED A. S. , XU YONGHONG
Published: January 2009

In this paper, we present TQPF, a Timing-Driven Quadratic-based Placement Tool for FPGAs. Quadratic placement algorithms try to minimize total squared wire length by solving linear equations. The resulting placement tends to locate all cells near the center of the chip with a large amount of overlap. Also, since squared wire length is only an indirect measure of linear wire length, the resulting total wire length may not be minimized. We propose methods to alleviate the above two problems that give high-quality results while minimizing the total run time. We incorporate multiple iterations of equation-solving process together with a technique for pulling nodes out of the dense area while minimizing linear wire length. Experimental results using 20 Microelectronics Center of North Carolina (MCNC) benchmark circuits show that, on average, TQPF is approximately three times faster than the well-known Versatile Placement and Routing tool for FPGAs (VPR). The estimated total wire length, on average, is only 1.4% longer, and the critical path delay is 4.9% lower.
HISTORY AND PROGRESS OF THE KERWIN–HUELSMAN–NEWCOMB FILTER GENERATION AND OP AMP REALIZATIONS
Authors: SOLIMAN AHMED M.
Published: January 2009

The history of Kerwin–Huelsman–Newcomb (KHN) second-order filter is reviewed. A generation method of the KHN filter from passive RLC filter is presented. Two alternative forms of the KHN circuit using operational amplifier are reviewed. The effect of finite gain-bandwidth of the op amps is considered and expressions of the actual ω0and Q are given. Two KHN circuits with inherently stable Q factor are also included. Two new partially compensated inverted KHN circuits are introduced. Active compensation methods to improve the KHN and the inverted KHN circuit performance for high Q designs are summarized. Spice simulation results are given. The progress of the KHN realizations using the current conveyor is also summarized briefly.
OPTIMAL DESIGN OF BINARY WEIGHTED k-OUT-OF-n SYSTEMS
Authors: LI WEI , ZUO MING J. , DING YI
Published: January 2009

In this paper, we consider the optimal design of the binary weighted k-out-of-n system. The binary weighted k-out-of-n: G system works if and only if the total utility of all working components is at least k. In the design process, we need to evaluate system reliability repetitively. The universal generating function (UGF) approach is used for this purpose when the system size is small or moderate. When the size of the system is large, the recursive approach is used, which is more efficient. Two optimal models are formulated. One is to minimize the expected total cost while guaranteeing the system reliability higher than a pre-specified value; the other is to maximize the system reliability with the constraints on total system cost. Genetic algorithms (GA) and Tabu Search (TS) methods are both used to solve the proposed optimization models. Since the key to a good TS algorithm is usually quite problem-specific policies and memory structures, there is no existing general TS tool available. Therefore more details of the TS approach used in this paper are discussed than the GA approach. The results obtained with these two methods are compared. The results illustrate that both methods are powerful tools for solving these kinds of problems. However TS is more efficient than GA in computation. The materials in this paper have been published in 19.
INTEGRATING DATA MINING TO A PROCESS DESIGN USING THE ROBUST BAYESIAN APPROACH
Authors: JEONG HEAJIN , SONG SUHILL , SHIN SANGMUN , RAE CHO BYUNG
Published: January 2009

Although process design optimization issues have received considerable attention from researchers for more than several decades, and a number of methodologies for modeling and optimizing the process have been developed, there is still ample room for improvement. Most research work has rarely considered the use of raw data from a manufacturing process database into the process design. However, the use of cumulative raw data can be a vital component in optimizing processes. To address this, we propose a new process design procedure called robust-Bayesian data mining (RBDM). First, we show how data mining techniques and a correlation-based feature selection (CBFS) method can be applied effectively to the selection of significant factors. Second, we then show how RBDM can be incorporated into robust design. Third, we present how the proposed RBDM estimates process parameters by considering the concept of robustness of the estimated parameters while incorporating the concept of noise factors. Finally, we present numerical examples to illustrate the efficiency of the proposed RBDM as a design tool for optimizing manufacturing processes.
Impact of Tick-Size Reduction on the Market Liquidity — Evidence from the Emerging Order-Driven Market
Authors: Hsieh Tzung-Yuan , Chuang Shaung-Shii , Lin Ching-Chung
Published: January 2009

Empirical studies on the influence of tick-size reduction towards market liquidity have focused almost exclusively on quote-driven markets in developed nations, and generally their findings are based on time periods of less than one year. This work investigates the influence of tick-size reduction and the relaxations of binding-constraint probability on market liquidity in the Taiwanese stock market, an emerging order-driven market, starting on March 1, 2005. The empirical results show that the spread, depth, market liquidity, and binding-constraint probability all decrease following the tick-size reduction, especially for low-priced stocks. These results can be attributed to relaxation of binding constraints. Additionally, stocks that are frequently traded, have larger market capitalization, or have restrictive binding constraints, experience considerable declines in spread, depth, and market liquidity following tick-size reduction. Trading activity plays an important role in explaining changes in spread, depth, market liquidity, and binding constraints. Thus, tick-size reduction in the Taiwanese Stock Market can increase market efficiency and reduce the investors' trading costs.
FACTORS THAT IMPACT TECHNOLOGY INNOVATION ADOPTION AMONG IRISH PROFESSIONAL SERVICE SECTOR SMES
Authors: RAMSEY ELAINE , IBBOTSON PATRICK , MCCOLE PATRICK
Published: January 2009

This paper disseminates the findings from a study into the factors impacting technological innovation adoption and diffusion specific to the deployment of electronic-commerce strategies within professional service sector SMEs in Ireland. Confirmatory factor analysis was performed and seven factors relating to a firm's external/internal environment were found to underpin adoption. These are: electronic-commerce capability; willingness to change/rate of response to new technologies; technological opportunity recognition; customer orientation; sensitivity to competitive/customer environments; perceptions of technology feasibility; and e-skills development mechanisms. t-tests revealed differences between adopters and non-adopters, and forward stepwise logistic regression is used to assess the extent to which these seven factors actually predict electronic-commerce adoption. It was found that electronic-commerce capability and the willingness to change/rate of response to new technologies are the two most important factors affecting adoption behaviours.
FACTORS INFLUENCING AN ORGANISATION'S ABILITY TO MANAGE INNOVATION: A STRUCTURED LITERATURE REVIEW AND CONCEPTUAL MODEL
Authors: SMITH MARISA , BUSI MARCO , BALL PETER , VAN DER MEER ROBERT
Published: January 2009

Management literature prescribes innovation as a stimulus for sustained competitive advantage in companies; however, the nature of the development in this field has resulted in the literature being broad and fragmented. This paper focuses on the body of literature concerned with the factors which influence innovation management in organisations. The aim of this research is to present a holistic view of the factors that affect innovation management. Using a systematic literature review approach, using over 100 papers, this research identifies nine key factors that impact on an organisation's ability to manage innovation. These nine factors have been identified as management style and leadership, resources, organisational structure, corporate strategy, technology, knowledge management, employees and innovation process. This paper then discusses the inductively derived model that presents the important relationships identified between the factors to present a holistic view of innovation management. From this, we open up the debate on innovation management as a systemic approach rather than being focused on the singular factors. We can therefore conclude that a number of dominant relationships exist between the factors with the innovation process being the only endogenous factor within the model.
A FRAMEWORK FOR MANAGING THE FORECASTING PROCESS
Authors: DAIM TUGRUL U. , HERNANDEZ ABRAHAM
Published: January 2009

Technological innovation is used by many companies as a means of sustaining their competitive advantage. The environments in which this innovation occurs is usually uncertain, therefore, many companies perform technological forecasting in association with their technological innovation processes. While many researchers have studied the innovation process and many more forecasting methods, there is little research connecting the two within the strategic context of the firm. To do this, a model of the forecasting process is needed. The purpose of this paper is to present a model based on a literature review. Previous models which formed the basis for the proposed model will be discussed followed by an explanation of the model and conclusion. Finally, a case study is presented to observe and test the proposed model.
SEGMENTATION OF LUNG PATTERNS IN HIGH-RESOLUTION COMPUTED TOMOGRAPHY IMAGES OF THE LUNG
Authors: SHAMSHEYEVA ALENA , SOWMYA ARCOT , WILSON PETER
Published: January 2009

An automated method is presented for segmentation of two-dimensional HRCT images of the lung into regions of four lung patterns: normal, emphysema, honeycombing, and ground-glass opacity (GGO). Segmentation was implemented in two stages. At the first stage, pixel-wise classification of the lung area was performed using local textural features extracted by the wavelet transform. At the second stage, classification results were refined by application of knowledge-based rules. Performance of the method was compared on two sets of HRCT images: one included HRCT images with characteristic examples of lung patterns and the other consisted of unselected HRCT images that represented a model of routine operations at a general radiology practice. On the first set of images, sensitivity of the method ranged from 0.92 to 0.99, and specificity ranged from 0.96 to 0.99. On the second set of images, sensitivity and specificity were, respectively, 0.49 and 0.95 for emphysema, 0.87 and 0.55 for normal, 0.34 and 0.99 for honeycombing, and 0.57 and 0.94 for GGO. The two-stage approach allowed for simple and effective application of high-level knowledge about appearance of lung patterns on HRCT images and did not require feature and region of interest size selection for the first stage of pixel-wise lung pattern classification.
ON THE COMPLEXITY AND ENERGY ANALYSES IN EEG BETWEEN ALCOHOLIC AND CONTROL SUBJECTS DURING DELAYED MATCHING TO SAMPLE PARADIGM
Authors: BALLI TUGCE , PALANIAPPAN RAMASWAMY
Published: January 2009

In this study, we have investigated the electrophysiological differences between alcoholic and control subjects using two different approaches namely complexity and energy (power) analyses. The electroencephalogram data used in this study were recorded from 77 alcoholic and 44 control subjects while the subjects were performing delayed matching to sample object recognition task for three types of stimuli. These were a single stimulus and a second matching or nonmatching stimulus that followed the single stimulus after a delay. The experimental paradigm evokes object recognition, visual short-term memory, and decision-making abilities. The results indicated that all regions (i.e. frontal, central, temporal, parietal, and occipital) in the brain exhibit more complexity and less energy for alcoholic subjects as compared to controls. When different visual stimuli pairs were compared among alcoholic and control subjects, the results from energy analysis showed groupwise differences in occipital and parietal regions. These results provide a strong indication on the impairment in brain's electrophysiological activity for alcoholic subjects due to a history of long-term alcohol abuse.
INTELLIGENT DATA ANALYSIS FOR THE CLASSIFICATION OF BODY SURFACE POTENTIAL MAPS
Authors: DONNELLY MARK P. , NUGENT CHRIS D. , FINLAY DEWAR D. , BLACK NORMAN D.
Published: January 2009

Body surface potential maps were investigated to identify a set of optimal recording sites required to discriminate between several diseases. Specifically, recordings captured from subjects exhibiting myocardial infarction or left ventricular hypertrophy, as well as a control group consisting of healthy subjects, were investigated. Owing to the fact that multi-class problems are inherently difficult to solve we divided the problem into several two-class scenarios. Six data sets were generated from the available 744 records, each viewing the available data differently, to form several two-class problems. A data-driven selection algorithm was applied to each of the generated data sets to produce six classification models, each utilizing as features those recording sites offering most to the discrimination task being investigated. Subsequently, a framework was introduced to facilitate the combination of outputs from each classifier. Essentially, the framework used the outputs from half of the classification models to determine which of the remaining models would be employed to form a final decision. A benchmark, in the form of a multi-group classifier, was introduced to evaluate the perceived benefits of the proposed approach. An improvement of approximately 10% upon the benchmark was observed resulting in an overall accuracy of 79.19%.
PREDICTION OF ELBOW TRAJECTORY FROM SHOULDER ANGLES USING NEURAL NETWORKS
Authors: KALIKI RAHUL R. , DAVOODI RAHMAN , LOEB GERALD E.
Published: January 2009

Patients with transhumeral amputations and C5/C6 quadriplegia may be able to use voluntary shoulder motion as command signals for powered prostheses and functional electrical stimulation, respectively. Spatiotemporal synergies exist between the shoulder and elbow joints for goal-oriented reaching movements as performed by able-bodied subjects. We are using a multi-layer perceptron neural network to discover and embody these synergies. Such a network could be used as a high-level controller that could predict the desired distal arm joint kinematics from the voluntary movements of the shoulder joint of an able-bodied subject. We evaluated this for a task that involved reaching to 16 targets in a horizontal plane. After reaching reasonable offline prediction accuracy for our neural networks, we then deployed the best network to make real-time predictions of the elbow angles and examined its performance on both inter- and intra-subject trials. Finally, we extended the model to utilize the five degrees-of-freedom at the shoulder to control the five degrees-of-freedom required for a prosthetic arm and hand to reach and grasp variously oriented objects in the extrapersonal workspace. Such a system, although very simple, was readily controllable for a reach and grasp task presented to the subject in a virtual reality environment.
Gsα deficiency in skeletal muscle leads to reduced muscle mass, fiber-type switching, and glucose intolerance without insulin resistance or deficiency
Authors: Chen Min , Feng Han-Zhong , Gupta Divakar , Kelleher James , Dickerson Kathryn E. , Wang Jie , Hunt Desmond , Jou William , Gavrilova Oksana , Jin Jian-Ping , Weinstein Lee S.
Published: January 2009

The ubiquitously expressed G protein α-subunit Gsα is required for receptor-stimulated intracellular cAMP responses and is an important regulator of energy and glucose metabolism. We have generated skeletal muscle-specific Gsα-knockout (KO) mice (MGsKO) by mating Gsα-floxed mice with muscle creatine kinase-cre transgenic mice. MGsKO mice had normal body weight and composition, and their serum glucose, insulin, free fatty acid, and triglyceride levels were similar to that of controls. However, MGsKO mice were glucose intolerant despite the fact that insulin sensitivity and glucose-stimulated insulin secretion were normal, suggesting an insulin-independent mechanism. Isolated muscles from MGsKO mice had increased basal glucose uptake and normal responses to a stimulator of AMP-activated protein kinase (AMPK), which indicates that AMPK and its downstream pathways are intact. Compared with control mice, MGsKO mice had reduced muscle mass with decreased cross-sectional area and force production. In addition, adult MGsKO mice showed an increased proportion of type I (slow-twitch, oxidative) fibers based on kinetic properties and myosin heavy chain isoforms, despite the fact that these muscles had reduced expression of peroxisome proliferator-activated receptor coactivator protein-1α (PGC-1α) and reduced mitochondrial content and oxidative capacity. Therefore Gsα deficiency led to fast-to-slow fiber-type switching, which appeared to be dissociated from the expected change in oxidative capacity. MGsKO mice are a valuable model for future studies of the role of Gsα signaling pathways in skeletal muscle adaptation and their effects on whole body metabolism.
Protein kinase B activity is required for the effects of insulin on lipid metabolism in adipocytes
Authors: Berggreen Christine , Gormand Amélie , Omar Bilal , Degerman Eva , Göransson Olga
Published: January 2009

Protein kinase B (PKB) is known to mediate a number of biological responses to insulin and growth factors, its role in glucose uptake being one of the most extensively studied. In this work, we have employed a recently described allosteric inhibitor of PKB, Akti, to clarify the role of PKB in lipid metabolism in adipocytes—a subject that has received less attention. Pretreatment of primary rat and 3T3L1 adipocytes with Akti resulted in dose-dependent inhibition of PKB phosphorylation and activation in response to insulin, without affecting upstream insulin signaling [insulin receptor (IR), insulin receptor substrate (IRS)] or the insulin-induced phosphoinositide 3-kinase (PI3K)-dependent activation of the ERK/p90 ribosomal kinase (RSK) pathway. PKB activity was required for the insulin-induced activation of phosphodiesterase 3B (PDE3B) and for the antilipolytic action of insulin. Moreover, inhibition of PKB activity resulted in a reduction in de novo lipid synthesis and in the ability of insulin to stimulate this process. The regulation of the rate-limiting lipogenic enzyme acetyl-CoA carboxylase (ACC) by insulin through dephosphorylation of S79, which is a target for AMP-activated protein kinase (AMPK), was dependent on the presence of active PKB. Finally, AMPK was shown to be phosphorylated by PKB on S485 in response to insulin, and this was associated with a reduction in AMPK activity. In summary, we propose that PKB is required for the positive effects of insulin on lipid storage and that regulation of PDE3B and AMPK by PKB is important for these effects.
Amino acid transceptors: gate keepers of nutrient exchange and regulators of nutrient signaling
Authors: Hundal Harinder S. , Taylor Peter M.
Published: January 2009

Amino acid transporters at the surface of cells are in an ideal location to relay nutritional information, as well as nutrients themselves, to the cell interior. These transporters are able to modulate signaling downstream of intracellular amino acid receptors by regulating intracellular amino acid concentrations through processes of coupled transport. The concept of dual-function amino acid transporter/receptor (or “transceptor”) proteins is well established in primitive eukaryotes such as yeast, where detection of extracellular amino acid deficiency leads to upregulation of proteins involved in biosynthesis and transport of the deficient amino acid(s). The evolution of the “extracellular milieu” and nutrient-regulated endocrine controls in higher eukaryotes, alongside their frequent inability to synthesize all proteinaceous amino acids (and, hence, the requirement for indispensable amino acids in their diet), appears to have lessened the priority of extracellular amino acid sensing as a stimulus for metabolic signals. Nevertheless, recent studies of amino acid transporters in flies and mammalian cell lines have revealed perhaps unanticipated “echoes” of these transceptor functions, which are revealed by cellular stresses (notably starvation) or gene modification/silencing. APC-transporter superfamily members, including slimfast, path, and SNAT2 all appear capable of sensing and signaling amino acid availability to the target of rapamycin (TOR) pathway, possibly through PI 3-kinase-dependent mechanisms. We hypothesize (by extrapolation from knowledge of the yeast Ssy1 transceptor) that, at least for SNAT2, the transceptor discriminates between extracellular and intracellular amino acid stimuli when evoking a signal.
UDP-glucose modulates gastric function through P2Y14 receptor-dependent and -independent mechanisms
Authors: Bassil Anna K. , Bourdu Sophie , Townson Karen A. , Wheeldon Alan , Jarvie Emma M. , Zebda Noureddine , Abuin Alejandro , Grau Evelyn , Livi George P. , Punter Lorraine , Latcham Judith , Grimes Angela M. , Hurp David P. , Downham Kelly M. , Sanger Gareth J. , Winchester Wendy J. , Morrison Alastair D. , Moore Gary B. T.
Published: January 2009

P2Y receptors have been reported to modulate gastrointestinal functions. The newest family member is the nucleotide-sugar receptor P2Y14. P2ry14 mRNA was detected throughout the rat gut, with the highest level being in the forestomach. We investigated the role of the receptor in stomach motility using cognate agonists and knockout (KO) mice. In rat isolated forestomach, 100 μM UDP-glucose and 100 μM UDP-galactose both increased the baseline muscle tension (BMT) by 6.2 ± 0.6 and 1.6 ± 0.6 mN ( P < 0.05, n = 3–4), respectively, and the amplitude of contractions during electrical field stimulation (EFS) by 3.7 ± 1.7 and 4.3 ± 2.5 mN ( P < 0.05, n = 3–4), respectively. In forestomach from wild-type (WT) mice, 100 μM UDP-glucose increased the BMT by 1.0 ± 0.1 mN ( P <0.05, n = 6) but this effect was lost in the KO mice (change of −0.1 ± 0.1 mN, n = 6). The 100 μM UDP-glucose also increased the contraction amplitude during EFS in this tissue from the WT animals (0.9 ± 0.4 mN, P < 0.05, n = 6) but not from the KO mice (0.0 ± 0.2 mN, n = 6). In vivo, UDP-glucose at 2,000 mg/kg ip reduced gastric emptying in rats by 49.7% ( P < 0.05, n = 4–6) and in WT and KO mice by 56.1 and 66.2%, respectively ( P < 0.05, n = 7–10) vs. saline-treated control animals. There was no significant difference in gastric emptying between WT and KO animals receiving either saline or d-glucose. These results demonstrate a novel function of the P2Y14 receptor associated with contractility in the rodent stomach that does not lead to altered gastric emptying after receptor deletion and an ability of UDP-glucose to delay gastric emptying without involving the P2Y14 receptor.
Expression of intracellular cytokines, HSP72, and apoptosis in monocyte subsets during exertional heat stress in trained and untrained individuals
Authors: Selkirk G. A. , McLellan T. M. , Wright H. E. , Rhind S. G.
Published: January 2009

This study examined intracellular cytokine, heat shock protein (HSP) 72, and cellular apoptosis in classic and inflammatory CD14+monocyte subsets during exertional heat stress (EHS). Subjects were divided into endurance-trained [TR; n = 12, peak aerobic power (V̇o2peak) = 70 ± 2 ml·kg lean body mass (LBM)−1·min−1] and sedentary-untrained (UT; n = 11, V̇o2peak= 50 ± 1 ml·kg LBM−1·min−1) groups before walking at 4.5 km/h with 2% elevation in a climatic chamber (40°C, 30% relative humidity) wearing protective clothing until exhaustion (Exh). Venous blood samples at baseline and 0.5°C rectal temperature increments (38.0, 38.5, 39.0, 39.5, and 40.0°C/Exh) were analyzed for cytokines (TNF-α, IL-1β, IL-6, IL-1ra, and IL-10) in CD14++CD16−/CD14+CD16+and HSP72/apoptosis in CD14Bri/CD14Dimsubsets. In addition, serum levels of extracellular (e)HSP72 were also examined. Baseline and Exh samples were separately stimulated with LPS (1 μg/ml) or heat shocked (42°C) and cultured in vitro for 2 h. A greater temperature-dependent increase in CD14+CD16+cells was observed in TR compared with UT subjects as well as a greater LPS tolerance following in vitro LPS stimulation. TNF-α and IL-1β cytokine expression was elevated in CD14+CD16+but not in CD14++CD16−cells. A greater induction of intracellular HSP72 and eHSP72 was observed in TR compared with UT subjects, which coincided with reduced apoptosis at Exh and following in vitro heat shock. Induced HSP in vitro was not uniform across CD14+subsets. Findings suggest that circulating CD14+CD16+, but not CD14++CD16−monocytes, contribute to the proinflammatory cytokine profiles observed during EHS. In addition, the enhanced HSP72 response in endurance-trained individuals may confer improved heat tolerance through both anti-inflammatory and anti-apoptotic mechanisms.
SGK1-sensitive renal tubular glucose reabsorption in diabetes
Authors: Ackermann Teresa F. , Boini Krishna M. , Völkl Harald , Bhandaru Madhuri , Bareiss Petra M. , Just Lothar , Vallon Volker , Amann Kerstin , Kuhl Dietmar , Feng Yuxi , Hammes Hans-Peter , Lang Florian
Published: January 2009

The hyperglycemia of diabetes mellitus increases the filtered glucose load beyond the maximal tubular transport rate and thus leads to glucosuria. Sustained hyperglycemia, however, may gradually increase the maximal renal tubular transport rate and thereby blunt the increase of urinary glucose excretion. The mechanisms accounting for the increase of renal tubular glucose transport have remained ill-defined. A candidate is the serum- and glucocorticoid-inducible kinase SGK1. The kinase has been shown to stimulate Na+-coupled glucose transport in vitro and mediate the stimulation of electrogenic intestinal glucose transport by glucocorticoids in vivo. SGK1 expression is confined to glomerula and distal nephron in intact kidneys but may extend to the proximal tubule in diabetic nephropathy. To explore whether SGK1 modifies glucose transport in diabetic kidneys, Akita mice ( akita+/−), which develop spontaneous diabetes, have been crossbred with gene-targeted mice lacking SGK1 on one allele ( sgk1+/−) to eventually generate either akita+/−/ sgk1−/−or akita+/−/ sgk1+/+mice. Both akita+/−/ sgk1−/−and akita+/−/ sgk1+/+mice developed profound hyperglycemia (>20 mM) within ∼6 wk. Body weight and plasma glucose concentrations were not significantly different between these two genotypes. However, urinary excretion of glucose and urinary excretion of fluid, Na+, and K+, as well as plasma aldosterone concentrations, were significantly higher in akita+/−/ sgk1−/−than in akita+/−/ sgk1+/+mice. Studies in isolated perfused proximal tubules revealed that the electrogenic glucose transport was significantly lower in akita+/−/ sgk1−/−than in akita+/−/ sgk1+/+mice. The data provide the first evidence that SGK1 participates in the stimulation of renal tubular glucose transport in diabetic kidneys.
Representation of Dynamic Interaural Phase Difference in Auditory Cortex of Awake Rhesus Macaques
Authors: Scott Brian H. , Malone Brian J. , Semple Malcolm N.
Published: January 2009

Neurons in auditory cortex of awake primates are selective for the spatial location of a sound source, yet the neural representation of the binaural cues that underlie this tuning remains undefined. We examined this representation in 283 single neurons across the low-frequency auditory core in alert macaques, trained to discriminate binaural cues for sound azimuth. In response to binaural beat stimuli, which mimic acoustic motion by modulating the relative phase of a tone at the two ears, these neurons robustly modulate their discharge rate in response to this directional cue. In accordance with prior studies, the preferred interaural phase difference (IPD) of these neurons typically corresponds to azimuthal locations contralateral to the recorded hemisphere. Whereas binaural beats evoke only transient discharges in anesthetized cortex, neurons in awake cortex respond throughout the IPD cycle. In this regard, responses are consistent with observations at earlier stations of the auditory pathway. Discharge rate is a band-pass function of the frequency of IPD modulation in most neurons (73%), but both discharge rate and temporal synchrony are independent of the direction of phase modulation. When subjected to a receiver operator characteristic analysis, the responses of individual neurons are insufficient to account for the perceptual acuity of these macaques in an IPD discrimination task, suggesting the need for neural pooling at the cortical level.
Position Sensitivity of Feline Paraspinal Muscle Spindles to Vertebral Movement in the Lumbar Spine
Authors: Cao Dong-Yuan , Pickar Joel G. , Ge Weiginq , Ianuzzi Allyson , Khalsa Partap S.
Published: January 2009

Muscle spindles contribute to sensorimotor control by supplying feedback regarding muscle length and consequently information about joint position. While substantial study has been devoted to determining the position sensitivity of spindles in limb muscles, there appears to be no data on their sensitivity in the low back. We determined the relationship between lumbar paraspinal muscle spindle discharge and paraspinal muscle lengthening estimated from controlled cranialward movement of the L6vertebra in anesthetized cats. Ramp (0.4 mm/s) and hold displacements (0.2, 0.4, 0.6, 0.8, and 1.2 mm for 2.5 s) were applied at the L6spinous process. Position sensitivity was defined as the slope of the relationship between the estimated increase in muscle length and mean instantaneous frequency at each length. To enable comparisons with appendicular muscle spindles where joint angle was measured, we also calculated sensitivity in terms of the L6and L7intervertebral flexion angle (IVA). This angle was estimated from measurements of facet joint capsule strain (FJC) based on a previously established relationship between IVA and FJC strain in the cat lumbar vertebral column during lumbar flexion. Single-unit recordings were obtained from 12 muscle spindle afferents. Longissimus and multifidus muscles contained the receptive field of 10 and 2 afferents, respectively. Mean position sensitivity was 16.3 imp·s−1·mm−1[10.6–22.1, 95% confidence interval (CI), P < 0.001]. Mean angular sensitivity was 5.2 imp·s−1·°−1(2.6–8.0, P < 0.003). These slope estimates were more than 3.5 times greater compared with appendicular muscle spindles, and their CIs did not contain previous slope estimates for the sensitivity of appendicular spindles from the literature. Potential reasons for and the significance of the apparently high position sensitivity in the lumbar spine are discussed.
Mapping and Identification of GABAergic Neurons in Transgenic Mice Projecting to Cardiac Vagal Neurons in the Nucleus Ambiguus Using Photo-Uncaging
Authors: Frank J. G. , Jameson H. S. , Gorini C. , Mendelowitz D.
Published: January 2009

The neural control of heart rate is determined primarily by the activity of preganglionic parasympathetic cardiac vagal neurons (CVNs) originating in the nucleus ambiguus (NA) in the brain stem. GABAergic inputs to CVNs play an essential role in determining the activity of these neurons including a robust inhibition during each inspiratory burst. The origin of GABAergic innervation has yet to be determined however. A transgenic mouse line expressing green florescent protein (GFP) in GABAergic cells was used in conjunction with caged glutamate to identify both clusters and individual GABAergic neurons that evoke inhibitory GABAergic synaptic responses in CVNs. Transverse slices were taken with CVNs patch-clamped in the whole cell configuration. Sections containing both the pre-Botzinger complex as well as the calamus scriptorius were divided into ∼90 quadrants, each 200 × 200 μm and were sequentially photostimulated. Inhibitory post synaptic currents (IPSCs) were recorded in CVNs after a 5-ms photostimulation of 50 μM caged glutamate. The four areas that contained GABAergic cells projecting to CVNs were 200 μm medial, 400 μm medial, 200 μm ventral, and 1,200 μm dorsal and 1,000 μm medial to patched CVNs. Once foci of GABAergic cells projecting to CVNs were determined, photostimulation of individual GABAergic neurons was conducted. The results from this study suggest that GABAergic cells located in four specific areas project to CVNs, and that these cells can be individually identified and stimulated using photouncaging to recruit GABAergic neurotransmission to CVNs.
Sudden Drop in Ground Support Produces Force-Related Unload Response in Human Overground Walking
Authors: af Klint Richard , Nielsen Jens Bo , Sinkjaer Thomas , Grey Michael J.
Published: January 2009

Humans maneuver easily over uneven terrain. To maintain smooth and efficient gait the motor system needs to adapt the locomotor output to the walking environment. In the present study we investigate the role of sensory feedback in adjusting the soleus muscle activity during overground walking in 19 healthy volunteers. Subjects walked unrestrained over a hydraulically actuated platform. On random trials the platform was accelerated downward at 0.8 g, unloading the plantar flexor muscles in midstance or late stance. The drop of the platform resulted in a significant depression of the soleus muscle activity of −17.9% (SD 2) and −21.4% (SD 2), with an onset latency of 49 ms (SD 1) and 45 ms (SD 1) in midstance and late stance, respectively. Input to the vestibular apparatus (i.e., the head acceleration) occurred at a latency 10.0 ms (SD 2.4) following the drop and ankle dorsiflexion velocity was decreased starting 22 ms (SD 15) after the drop. To investigate the role of length- and velocity-sensitive afferents on the depression in soleus muscle activity, the ankle rotation was arrested by using an ankle foot orthotic as the platform was dropped. Preventing the ankle movement did not significantly change the soleus depression in late stance [−18.2% (SD 15)], whereas the depression in midstance was removed [+4.9% (SD 13)]. It is concluded that force feedback from ankle extensors increases the locomotor output through positive feedback in late stance. In midstance the effect of force feedback was not observed, suggesting that spindle afferents may have a more significant effect on the output during this phase of the step cycle.
Glu298Asp eNOS gene polymorphism causes attenuation in nonexercising muscle vasodilatation
Authors: Dias Rodrigo G. , Alves Maria-Janieire N. N. , Pereira Alexandre C. , Rondon Maria Urbana P. B. , dos Santos Marcelo R. , Krieger José E. , Krieger Marta H. , Negrão Carlos E.
Published: January 2009

The influence of Glu298Asp endothelial nitric oxide synthase (eNOS) polymorphism in exercise-induced reflex muscle vasodilatation is unknown. We hypothesized that nonexercising forearm blood flow (FBF) responses during handgrip isometric exercise would be attenuated in individuals carrying the Asp298 allele. In addition, these responses would be mediated by reduced eNOS function and NO-mediated vasodilatation or sympathetic vasoconstriction. From 287 volunteers previously genotyped, we selected 33 healthy individuals to represent three genotypes: Glu/Glu [ n = 15, age 43 ± 3 yr, body mass index (BMI) 22.9 ± 0.3 kg/m2], Glu/Asp ( n = 9, age 41 ± 3 yr, BMI 23.7 ± 1.0 kg/m2), and Asp/Asp ( n = 9, age 40 ± 4 yr, BMI 23.5 ± 0.9 kg/m2). Heart rate (HR), mean blood pressure (MBP), and FBF (plethysmography) were recorded for 3 min at baseline and 3 min during isometric handgrip exercise. Baseline HR, MBP, FBF, and forearm vascular conductance (FVC) were similar among genotypes. FVC responses to exercise were significantly lower in Asp/Asp when compared with Glu/Asp and Glu/Glu (Δ = 0.07 ± 0.14 vs. 0.64 ± 0.20 and 0.57 ± 0.09 units, respectively; P = 0.002). Further studies showed that intra-arterial infusion of NG-monomethyl-l-arginine (l-NMMA) did not change FVC responses to exercise in Asp/Asp, but significantly reduced FVC in Glu/Glu (Δ = 0.79 ± 0.14 vs. 0.14 ± 0.09 units). Thus the differences between Glu/Glu and Asp/Asp were no longer observed ( P = 0.62). l-NMMA + phentolamine increased similarly FVC responses to exercise in Glu/Glu and Asp/Asp ( P = 0.43). MBP and muscle sympathetic nerve activity increased significant and similarly throughout experimental protocols in Glu/Glu and Asp/Asp. Individuals who are homozygous for the Asp298 allele of the eNOS enzyme have attenuated nonexercising muscle vasodilatation in response to exercise. This genotype difference is due to reduced eNOS function and NO-mediated vasodilatation, but not sympathetic vasoconstriction.
Eventually Periodic Solutions for Difference Equations with Periodic Coefficients and Nonlinear Control Functions
Authors: Hou Chengmin , Cheng Sui Sun
Published: January 2009

For nonlinear difference equations of the form xn = F(n, xn−1, …, xn−m), it is usually difficult to find periodic solutions. In this paper, we consider a class of difference equations of
the form xn = anxn−1 + bnf(xn−k), where {an},   {bn} are periodic sequences and f is a nonlinear filtering function, and show how periodic solutions can be constructed. Several examples are also included to illustrate our results.
Extra‐High‐Voltage DC‐DC Boost Converters Topology with Simple Control Strategy
Authors: Sanjeevikumar P. , Rajambal K.
Published: January 2009

This paper presents the topology of operating DC‐DC buck converter in boost mode for extra‐high‐voltage applications. Traditional DC‐DC boost converters are used in high‐voltage applications, but they are not economical due to the limited output voltage, efficiency and they require two sensors with complex control algorithm. Moreover, due to the effect of parasitic elements the output voltage and power transfer efficiency of DC‐DC converters are limited. These limitations are overcome by using the voltage lift technique, opens a good way to improve the performance characteristics of DC‐DC converter. The technique is applied to DC‐DC converter and a simplified control algorithm in this paper. The performance of the controller is studied for both line and load disturbances. These converters perform positive DC‐DC voltage increasing conversion with high power density, high efficiency, low cost in simple structure, small ripples, and wide range of control. Simulation results along theoretical analysis are provided to verify its performance.
An Agent Infrastructure over HLA for Distributed Simulation of Reconfigurable Systems and its Application to UAV Coordination*
Authors: Cicirelli Franco , Furfaro Angelo , Nigro Libero
Published: January 2009

This paper proposes an agent infrastructure (Theatre) centered on Java for distributed simulations over High-Level Architecture/RunTime Infrastructure (HLA/RTI). The architecture rests on actors (agents) as the basic building blocks. Actors have a public message interface and encapsulate a state of local variables and a behavior patterned as a finite state machine. Actors interact with one another by asynchronous message passing. At the system level, theatres are used as the execution platforms for actors. Theatres naturally map on to HLA federates. Actors can migrate between theatres for load-balancing concerns, or in response to (re)configuration operations of dynamic structure systems. The paper introduces Theatre and demonstrates its application to a complex simulation model based on unmanned aerial vehicles (UAVs). The case study is an open agent-based distributed model where mobile agents follow communication patterns established at runtime.
An Underwater Vehicle Simulator with Immersive Interface using X3D and HLA
Authors: Hur Pilwon , Yang Jeongsam , Han Soonhung , Yoo Byounghyun
Published: January 2009

Training war fighters how to maneuver a submarine is very important, but the use of real submarines in such training is expensive and hindered by regional and temporal limitations. Modeling and simulation (M&S) can be a good alternative to costly training. However, the use of existing M&S for submarines has limitations. For instance, the commercial software and hardware need to be kept in a secure place. Depending on the location of the protected software, war fighters may travel far and take a considerable amount of time to get to these places. Long-distance travel also means they have a limited amount of time to train on the M&S machines. Furthermore, many types of M&S have only a one-channel display system, which reduces immersiveness. Another problem is that few heterogeneous simulators can be used as an integrated system. One solution to these problems involves the use of extensible 3D (X3D) graphics, a platform-independent and open standard graphic file format, which can be used with general purpose PCs. The immersiveness is increased by means of a multichannel display system and a motion chair. Finally, the individual components of a simulator can be integrated with the high level architecture and run time infrastructure (HLA/RTI). We demonstrate the proposed method through experiments with an underwater vehicle simulator.
The Study of Sorption of Toxic Basic Dyes from Aqueous Solutions on H2O 2 Treated Recycled Wool-based Nonwoven Material and Related Toxicity Analysis
Authors: Ilić Vesna , Radojević Darinka , Mihailović Darka , Radetić Maja , Jovančić Petar , Farré Marinella , Barceló Damià
Published: January 2009

The aim of this study was to investigate the potential use of recycled wool-based nonwoven material for removal of basic dyes C.I. Basic Yellow 28 and C.I. Basic Red 46 from aqueous solutions. To improve the sorption properties, the recycled wool-based nonwoven material was treated with hydrogen peroxide. The sorption capacity, the sorption kinetics, and the influence of initial dye concentration and pH on the sorption were studied. The acute toxicity of dyes was evaluated using a ToxAlert® 100 biological test, which is based on inhibition of the bioluminescence of Vibrio fischeri . The percent of inhibition ( %I) before and after the sorption, 50 % effective concentration ( EC50) and toxicity units ( TU) were determined. The results indicated that recycled wool-based nonwoven material can be used as an efficient sorbent for removal of investigated basic dyes. Hydrogen peroxide treatment considerably improved the sorption properties of the material for both dyes. The sorption kinetics of dyes on the hydrogen peroxide treated material obeyed pseudo-second order kinetic model. The Freundlich sorption isotherm was found to represent well the experimental sorption data. The increase of initial dye concentration and pH positively affected the sorption of basic dyes. An ion exchange mechanism of dye sorption was confirmed by desorption studies. The toxicity decreased after the sorption of both dyes.
Depigmentation of Pigmented Wool
Authors: Montazer Majid , Zargaran Moghdeh , Rahimi Ameneh
Published: January 2009

Pigmented wool yarn contains an excessive amount of melanin responsible for its black or brown color. Depigmented wool yarns were prepared by pre-mordanting then acidic rinsing and finally bleaching. Some of the physical and chemical properties of the treated yarns such as color, strength and alkali solubility were tested. The results showed that the oxidative/reductive bleaching process produced wool yarns with better optical properties than the oxidative bleaching process, but increasing concentrations of thiourea further decreased the yarn tensile strength. Scanning electron microscopy confirmed fiber surface damage was greatest following the oxidative/reductive bleaching process. The results also indicated that minimal fiber damage could be obtained using commercial ferrous sulfate in acidic media (citric acid) with improved iron absorbency.