bluuebunny/crossref_metadata_2025 huggingface dataset:
Reductions in laminin β2 mRNA translation are responsible for impaired IGFBP-5-mediated mesangial cell migration in the presence of high glucose
Authors: Schaeffer Valerie , Hansen Kim M. , Morris David R. , Abrass Christine K.
Published: October 2009

Insulin-like growth factor binding protein-5 (IGFBP-5) mediates mesangial cell migration through activation of cdc42, and laminin421 binding to α6β1-integrin (Berfield AK, Hansen KM, Abrass CK. Am J Physiol Cell Physiol 291: C589–C599, 2006). Because glomerular expression of laminin β2is reduced in diabetic rats (Abrass CK, Spicer D, Berfield AK, St. John PL, Abrahamson DR. Am J Pathol 151: 1131–1140, 1997), we directly examined the effect of hyperglycemia on mesangial cell migration and laminin β2 expression. Migration mediated by IGFBP-5 is impaired in the presence of 25 mM glucose. This reduction in migration was found to result from a loss in mesangial cell synthesis of laminin421, and IGFBP-5-induced migration could be restored by replacing laminin421. Additional studies showed that there was selective reduction in mRNA translation of laminin β2 in the presence of high glucose. Preserved synthesis of laminin β1 indicates that not all proteins are reduced by high glucose and confirms prior data showing that laminin411 cannot substitute for laminin421 in IGFBP-5-mediated migration. Given the importance of mesangial migration in the reparative response to diabetes-associated mesangiolysis, these findings provide new insights into abnormalities associated with diabetic nephropathy and the potential importance of differential control of protein translation in determination of alterations of protein expression.
Oxidative stress and gamma radiation-induced cancellous bone loss with musculoskeletal disuse
Authors: Kondo Hisataka , Yumoto Kenji , Alwood Joshua S. , Mojarrab Rose , Wang Angela , Almeida Eduardo A. C. , Searby Nancy D. , Limoli Charles L. , Globus Ruth K.
Published: October 2009

Exposure of astronauts in space to radiation during weightlessness may contribute to subsequent bone loss. Gamma irradiation of postpubertal mice rapidly increases the number of bone-resorbing osteoclasts and causes bone loss in cancellous tissue; similar changes occur in skeletal diseases associated with oxidative stress. Therefore, we hypothesized that increased oxidative stress mediates radiation-induced bone loss and that musculoskeletal disuse changes the sensitivity of cancellous tissue to radiation exposure. Musculoskeletal disuse by hindlimb unloading (1 or 2 wk) or total body gamma irradiation (1 or 2 Gy of 137Cs) of 4-mo-old, male C57BL/6 mice each decreased cancellous bone volume fraction in the proximal tibiae and lumbar vertebrae. The extent of radiation-induced acute cancellous bone loss in tibiae and lumbar vertebrae was similar in normally loaded and hindlimb-unloaded mice. Similarly, osteoclast surface in the tibiae increased 46% as a result of irradiation, 47% as a result of hindlimb unloading, and 64% as a result of irradiation + hindlimb unloading compared with normally loaded mice. Irradiation, but not hindlimb unloading, reduced viability and increased apoptosis of marrow cells and caused oxidative damage to lipids within mineralized tissue. Irradiation also stimulated generation of reactive oxygen species in marrow cells. Furthermore, injection of α-lipoic acid, an antioxidant, mitigated the acute bone loss caused by irradiation. Together, these results showed that disuse and gamma irradiation, alone or in combination, caused a similar degree of acute cancellous bone loss and shared a common cellular mechanism of increased bone resorption. Furthermore, irradiation, but not disuse, may increase the number of osteoclasts and the extent of acute bone loss via increased reactive oxygen species production and ensuing oxidative damage, implying different molecular mechanisms. The finding that α-lipoic acid protected cancellous tissue from the detrimental effects of irradiation has potential relevance to astronauts and radiotherapy patients.
Arterial properties along the upper arm in humans: age-related effects and the consequence of anatomical location
Authors: Bjarnegård Niclas , Länne Toste
Published: October 2009

The normal aging process of the brachial artery (BA) wall is of specific interest since it is often selected as a model artery in studies of vascular function. With echo-tracking ultrasound, diameter, absolute diameter change, and intima-media thickness (IMT) were registered in 60 healthy subjects, 21–86 yr (30 men), at a proximal, upper third, and distal arterial site along the upper arm. Blood pressure was recorded noninvasively, and the distensibility coefficient (DC) was calculated. The diameter at the proximal site increased with age from 5.5 ± 0.2 mm in the young subjects to 6.9 ± 0.3 mm ( P < 0.01) in the elderly subjects, concomitantly as IMT increased from 0.40 ± 0.01 to 0.65 ± 0.03 mm ( P < 0.001). The diameter at the other sites was similar in the young and elderly subjects, whereas IMT increased slightly with age. At the proximal site, DC decreased dramatically from 40.7 ± 2.2 to 10.1 ± 0.8 10−3/kPa ( P < 0.001) with age, whereas hardly no change was seen in the distal upper arm. The principal transit zone between elastic to predominantly muscular artery behavior seems to be located within the proximal part of the brachial artery, emphasizing the importance of carefully defining the arterial examination site.
Dose-dependent relationship between severity of pediatric obesity and blunting of the growth hormone response to exercise
Authors: Oliver Stacy R. , Rosa Jaime S. , Minh Timothy D. C. , Pontello Andria M. , Flores Rebecca L. , Barnett Marcia , Galassetti Pietro R.
Published: October 2009

In children, exercise modulates systemic anabolism, muscle growth, and overall physiological development through the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis. GH secretion, at rest and during exercise, changes with age and maturational status and can be blunted by hyperlipidemia and obesity, with possible negative effects on physiological growth. However, little is known about the effect of progressively more severe pediatric obesity on the GH response to exercise and its relationship to pubertal status. We therefore studied 48 early- or late-pubertal obese children [body mass index (BMI) >95th percentile, separated in tertiles with progressively greater BMI] and 42 matched controls (BMI <85th percentile), who performed ten 2-min cycling bouts at ∼80% of maximal O2 consumption, separated by 1-min rest intervals. Plasma GH and IGF-I were measured at baseline and end exercise. GH responses were systematically blunted in obese children, with more pronounced blunting paralleling increasing BMI. Although overall the GH response to exercise was greater in late-pubertal than in younger children, this blunting pattern was observed in early- and late-pubertal children. Our results reveal insight into the interaction between pediatric obesity and key modulators of physiological growth and development and underscore the necessity of optimizing physical activity strategies for specific pediatric dysmetabolic conditions.
Role of AMPA and NMDA Receptors and Back-Propagating Action Potentials in Spike Timing–Dependent Plasticity
Authors: Fuenzalida Marco , Fernández de Sevilla David , Couve Alejandro , Buño Washington
Published: October 2009

The cellular mechanisms that mediate spike timing–dependent plasticity (STDP) are largely unknown. We studied in vitro in CA1 pyramidal neurons the contribution of AMPA and N-methyl-d-aspartate (NMDA) components of Schaffer collateral (SC) excitatory postsynaptic potentials (EPSPs; EPSPAMPA and EPSPNMDA) and of the back-propagating action potential (BAP) to the long-term potentiation (LTP) induced by a STDP protocol that consisted in pairing an EPSP and a BAP. Transient blockade of EPSPAMPA with 7-nitro-2,3-dioxo-1,4-dihydroquinoxaline-6-carbonitrile (CNQX) during the STDP protocol prevented LTP. Contrastingly LTP was induced under transient inhibition of EPSPAMPA by combining SC stimulation, an imposed EPSPAMPA-like depolarization, and BAP or by coupling the EPSPNMDA evoked under sustained depolarization (approximately −40 mV) and BAP. In Mg2+-free solution EPSPNMDA and BAP also produced LTP. Suppression of EPSPNMDA or BAP always prevented LTP. Thus activation of NMDA receptors and BAPs are needed but not sufficient because AMPA receptor activation is also obligatory for STDP. However, a transient depolarization of another origin that unblocks NMDA receptors and a BAP may also trigger LTP.
Relationships Between the Threshold and Slope of Psychometric and Neurometric Functions During Perceptual Learning: Implications for Neuronal Pooling
Authors: Gold Joshua I. , Law Chi-Tat , Connolly Patrick , Bennur Sharath
Published: October 2009

Perceptual learning involves long-lasting improvements in the ability to perceive simple sensory stimuli. Some forms of perceptual learning are thought to involve an increasingly selective readout of sensory neurons that are most sensitive to the trained stimulus. Here we report novel changes in the relationship between the threshold and slope of the psychometric function during learning that are consistent with such changes in readout and can provide insights into the underlying neural mechanisms. In monkeys trained on a direction-discrimination task, perceptual improvements corresponded to lower psychometric thresholds and slightly shallower slopes. However, this relationship between threshold and slope was much weaker in comparable, ideal-observer “neurometric” functions of neurons in the middle temporal (MT) area, which represent sensory information used to perform the task and whose response properties did not change with training. We propose a linear/nonlinear pooling scheme to account for these results. According to this scheme, MT responses are pooled via linear weights that change with training to more selectively read out responses from the most sensitive neurons, thereby reducing predicted thresholds. An additional nonlinear (power-law) transformation does not change with training and causes the predicted psychometric function to become shallower as uninformative neurons are eliminated from the pooled signal. We show that this scheme is consistent with the measured changes in psychometric threshold and slope throughout training. The results suggest that some forms of perceptual learning involve improvements in a process akin to selective attention that pools the most informative neural signals to guide behavior.
Neurons in Both Pallidal Segments Change Their Firing Properties Similarly Prior to Closure of the Eyes
Authors: Adler Avital , Joshua Mati , Rivlin-Etzion Michal , Mitelman Rea , Marmor Odeya , Prut Yifat , Bergman Hagai
Published: October 2009

Current anatomical models of the cortico–basal ganglia (BG) network predict reciprocal discharge patterns between the external and internal segments of the globus pallidus (GPe and GPi, respectively), as well as cortical driving of BG activity. However, physiological studies revealing similarity in the transient responses of GPe and GPi neurons cast doubts on these predictions. Here, we studied the discharge properties of GPe, GPi, and primary motor cortex neurons of two monkeys in two distinct states: when eyes are open versus when they are closed. Both pallidal populations exhibited decreased discharge rates in the “eye closed” state accompanied by elevated values of the coefficient of variation (CV) of their interspike interval (ISI) distributions. The pallidal modulations in discharge patterns were partially attributable to larger fractions of longer ISIs in the “eye closed” state. In addition, the pallidal discharge modulations were gradual, starting prior to closing of the eyes. Cortical neurons, as opposed to pallidal neurons, increased their discharge rates steeply on closure of the eyes. Surprisingly, the cortical rate modulations occurred after pallidal modulations. However, as in the pallidum, the CV values of cortical ISI distributions increased in the “eye closed” state, indicating a more bursty discharge pattern in that state. Thus changes in GPe and GPi discharge properties were positively correlated, suggesting that the subthalamic nucleus and/or the striatum constitute the main common driving force for both pallidal segments. Furthermore, the early, unexpected changes in the pallidum are better explained by a subcortical rather than a cortical loop through the BG.
Behavioral Time Course of Microstimulation in Cortical Area MT
Authors: Masse Nicolas Y. , Cook Erik P.
Published: October 2009

Electrical stimulation of the brain is a valuable research tool and has shown therapeutic promise in the development of new sensory neural prosthetics. Despite its widespread use, we still do not fully understand how current passed through a microelectrode interacts with functioning neural circuits. Past behavioral studies have suggested that weak electrical stimulation (referred to as microstimulation) of sensory areas of cortex produces percepts that are similar to those generated by normal sensory stimuli. In contrast, electrophysiological studies using in vitro or anesthetized preparations have shown that neural activity produced by brief microstimulation is radically different and longer lasting than normal responses. To help reconcile these two aspects of microstimulation, we examined the temporal properties that microstimulation has on visual perception. We found that brief application of subthreshold microstimulation in the middle temporal (MT) area of visual cortex produced smaller and longer-lasting effects on motion perception compared with an equivalent visual stimulus. In agreement with past electrophysiological studies, a computer simulation reproduced our behavioral effects when the time course of a single microstimulation pulse was modeled with three components: an immediate fast strong excitatory component, followed by a weaker inhibitory component, and then followed by a long duration weak excitatory component. Overall, these results suggest the behavioral effects of microstimulation in our experiments were caused by the unique and long-lasting temporal effects microstimulation has on functioning cortical circuits.
Spectrum and Generation of Solutions of the Toda Lattice
Authors: Barrios Rolanía D. , Gascón Márquez J. R.
Published: October 2009

Sufficient conditions for constructing a set of solutions of the Toda lattice are
analyzed. First, under certain conditions the invariance of the spectrum of J(t) is
established in the complex case. Second, given the tri‐diagonal matrix J(t) defining a Toda lattice solution, the dynamic behavior of zeros of polynomials associated to J(t) is analyzed. Finally, it is shown by means of an example how to apply our results to
generate complex solutions of the Toda lattice starting with a given solution.
Strong Convergence of Monotone Hybrid Method for Maximal Monotone Operators and Hemirelatively Nonexpansive Mappings
Authors: Klin-eam Chakkrid , Suantai Suthep
Published: October 2009

We prove strong convergence theorems for finding a common element of the zero point set of a maximal monotone operator and the fixed point set of a hemirelatively nonexpansive mapping in a Banach space by using monotone hybrid iteration method. By using these results, we obtain new convergence results for resolvents of maximal monotone operators and hemirelatively nonexpansive mappings in a Banach space.
Strong Convergence of Two Iterative Algorithms for Nonexpansive Mappings in Hilbert Spaces
Authors: Yao Yonghong , Liou Yeong Cheng , Marino Giuseppe
Published: October 2009

We introduce two iterative algorithms for nonexpansive mappings in Hilbert spaces. We prove that the proposed algorithms strongly converge to a fixed point of a nonexpansive mapping "Equation missing".
Plastic Optical Fibre Sensors for Structural Health Monitoring: A Review of Recent Progress
Authors: Kuang K. S. C. , Quek S. T. , Koh C. G. , Cantwell W. J. , Scully P. J.
Published: October 2009

While a number of literature reviews have been published in recent times on the applications of optical fibre sensors in smart structures research, these have mainly focused on the use of conventional glass‐based fibres. The availability of inexpensive, rugged, and large‐core plastic‐based optical fibres has resulted in growing interest amongst researchers in their use as low‐cost sensors in a variety of areas including chemical sensing, biomedicine, and the measurement of a range of physical parameters. The sensing principles used in plastic optical fibres are often similar to those developed in glass‐based fibres, but the advantages associated with plastic fibres render them attractive as an alternative to conventional glass fibres, and their ability to detect and measure physical parameters such as strain, stress, load, temperature, displacement, and pressure makes them suitable for structural health monitoring (SHM) applications. Increasingly their applications as sensors in the field of structural engineering are being studied and reported in literature. This article will provide a concise review of the applications of plastic optical fibre sensors for monitoring the integrity of engineering structures in the context of SHM.
When Salpingectomy Is Not Salpingectomy—Ipsilateral Recurrence of Tubal Pregnancy
Authors: Fischer Simona , Keirse Marc J. N. C.
Published: October 2009

Theoretically, total salpingectomy eliminates the risk of an ipsilateral tubal pregnancy. However, total salpingectomy is difficult to achieve using endoloops alone. We describe a situation where this resulted in an ipsilateral recurrence of tubal pregnancy which required emergency intervention and removal of the tubal remnants.
Transarterial Chemoembolization of Metastatic Colorectal Carcinoma with Drug-Eluting Beads, Irinotecan (DEBIRI): Multi-Institutional Registry
Authors: Martin Robert C. G. , Joshi Jonathan , Robbins Ken , Tomalty Dana , O’Hara Ryan , Tatum Cliff
Published: October 2009

The purpose of this study was to evaluate the patient tolerance and efficacy of delivering locoregional chemotherapy to metastatic colorectal (MC) hepatic metastases via hepatic trans-arterial approach using irinotecan loaded drug eluting beads. This open-label, multi-center, single arm study included 30 MC patients, who had failed first line therapy. Of the 57 total embolization sessions, 12 (21% of sessions) were associated with adverse reactions during or after the treatment. After a median followup of 9 months, response rates by modified RECIST were 75% at 3 months and 66% at 6 months. Hepatic trans-arterial therapy using Irinotecan loaded DCBeadTMwas safe and effective in the treatment of MCC as demonstrated by a minimal complication rate and acceptable tumor response.
A Novel Biosensor to Detect MicroRNAs Rapidly
Authors: Liao Jie-Ying , Yin James Q. , Yue Jia-Chang
Published: October 2009

δ‐free F0F1‐ATPase within chromatophore was constructed as a novel biosensor to detect miRNA targets. Specific miRNA probes were linked to each rotary β subunits of F0F1‐ATPase. Detection of miRNAs was based on the proton flux change induced by light‐driven rotation of δ‐free F0F1‐ATPase. The hybridization reaction was indicated by changes in the fluorescent intensity of pH‐sensitive CdTe quantum dots. Our results showed that the assay was attomole sensitivities (1.2 × 10−18 mol) to target miRNAs and capable of distinguishing among miRNA family members. Moreover, the method could be used to monitor real‐time hybridization without any complicated fabrication before hybridization. Thus, the rotary biosensor is not only sensitive and specific to detect miRNA target but also easy to perform. The δ‐free F0F1‐ATPase‐based rotary biosensor may be a promising tool for the basic research and clinical application of miRNAs.
The Roles of Platelet GPIIb/IIIa and αvβ3 Integrins during HeLa Cells Adhesion, Migration, and Invasion to Monolayer Endothelium under Static and Dynamic Shear Flow
Authors: Liu Yiyao , Zhao Fenglong , Gu Wentian , Yang Haishiu , Meng Quoquan , Zhang Yunxiang , Yang Hong , Duan Qi
Published: October 2009

During their passage through the circulatory system, tumor cells undergo extensive interactions with various host cells including endothelial cells and platelets. Mechanisms mediating tumor cell adhesion, migration, and metastasis to vessel wall under flow condition are largely unknown. The aim of this study was to investigate the potential roles of GPIIb/IIIa and αvβ3 integrins underlying the HeLa‐endothelium interaction in static and dynamic flow conditions. HeLa cell migration and invasion were studied by using Millicell cell culture insert system. The numbers of transmigrated or invaded HeLa cells significantly increased by thrombin‐activated platelets and reduced by eptifibatide, a platelet inhibitor. Meanwhile, RGDWE peptides, a specific inhibitor of αvβ3 integrin, also inhibited HeLa cell transmigration. Interestingly, the presence of endothelial cells had significant effect on HeLa cell migration regardless of static or cocultured flow condition. The adhesion capability of HeLa cells to endothelial monolayer was also significantly affected by GPIIb/IIIa and αvβ3 integrins. The arrested HeLa cells increased nearly 5‐fold in the presence of thrombin‐activated platelets at shear stress condition (1.84 dyn/cm2 exposure for 1 hour) than the control (static). Our findings showed that GPIIb/IIIa and αvβ3 integrins are important mediators in the pathology of cervical cancer and provide a molecular basis for the future therapy, and the efficient antitumor benefit should target multiple receptors on tumor cells and platelets.
A Seminalytical Approach to Large Deflections in Compliant Beams under Point Load
Authors: Tolou N. , Herder J. L.
Published: October 2009

The deflection of compliant mechanism (CM) which involves geometrical nonlinearity due to large
deflection of members continues to be an interesting problem in mechanical systems. This paper deals
with an analytical investigation of large deflections in compliant mechanisms. The main objective is to
propose a convenient method of solution for the large deflection problem in CMs in order to overcome
the difficulty and inaccuracy of conventional methods, as well as for the purpose of mathematical
modeling and optimization. For simplicity, an element is considered which is a cantilever beam out of
linear elastic material under vertical end point load. This can further be used as a building block in
more complex compliant mechanisms. First, the governing equation has been obtained for the
cantilever beam; subsequently, the Adomian decomposition method (ADM) has been utilized to obtain
a semianalytical solution. The vertical and horizontal displacements of a cantilever beam can
conveniently be obtained in an explicit analytical form. In addition, variations of the parameters that
affect the characteristics of the deflection have been examined. The results reveal that the proposed
procedure is very accurate, efficient, and convenient for cantilever beams, and can probably be applied
to a large class of practical problems for the purpose of analysis and optimization.
Plant-Soil Relationships ofBromus tectorumL.: Interactions among Labile Carbon Additions, Soil Invasion Status, and Fertilizer
Authors: Blank Robert R. , Young James A.
Published: October 2009

Invasion of western North America by the annual exotic grassBromus tectorumL. (cheatgrass) has been an ecological disaster. High soil bioavailability of nitrogen is a contributing factor in the invasive potential ofB. tectorum. Application of labile carbon sources to the soil can immobilize soil nitrogen and favor native species. We studied the interaction of labile carbon addition (sucrose), with soil invasion status and fertilizer addition on the growth ofB. tectorum. Soils were noninvaded (BNI) andB. tectoruminvaded (BI). Treatments were control, sucrose, combined fertilizer, and sucrose + fertilizer. The greenhouse experiment continued for 3 growth-cycles. After the 1st growth-cycle, sucrose addition reducedB. tectorumaboveground mass almost 70 times for the BI soil but did not significantly reduce growth in the BNI soil.B. tectorumaboveground mass, after the 1st growth-cycle, was over 27 times greater for BI control soils than BNI control soils. Although sucrose addition reduced soil-solution , tissue N was not significantly lowered, suggesting that reduction of soil available N may not be solely responsible for reduction inB. tectorumgrowth. Noninvaded soil inhibits growth ofB. tectorum. Understanding this mechanism may lead to viable control strategies.
Physical Models of Plasma Microfield
Authors: Demura A. V.
Published: October 2009

The present review is devoted to the current status of microfield notion that was so successful
and profitable for experimental and theoretical studies of plasma in gas discharges and thermonuclear
modeling installations for many decades. The physical aspects and ideas of the main generally
used microfield models are described and analyzed in detail. The review highlights the remaining
vague and unclear questions in the subject.
Detecting Cognitive Change in the Math Skills of Low-Achieving Adolescents
Authors: Cho Sun-Joo , Bottge Brian A. , Cohen Allan S. , Kim Seock-Ho
Published: October 2009

Current methods for detecting growth of students’ problem-solving skills in math focus mainly on analyzing changes in test scores. Score-level analysis, however, may fail to reflect subtle changes that might be evident at the item level. This article demonstrates a method for studying item-level changes using data from a multiwave experiment with a teaching method called enhanced anchored instruction (EAI). The analysis combines a mixture Rasch model for detecting individual differences within latent groups with a latent transition analysis model for tracking changes in latent group membership over the course of EAI. The analysis clearly indicates the effects of EAI and how they differ for members of each latent class. Comparisons are provided with a standard analysis of changes in test scores. Implications of the new approach are discussed for detecting subtle transformations in the math performance of students across a range of ability levels.
Measuring Tourists’ Emotional Experiences toward Hedonic Holiday Destinations
Authors: Hosany Sameer , Gilbert David
Published: October 2009

Destinations are more likely to be successful if they recognize the experiential qualities of their offerings. However, with some exceptions, research into the emotional content of the destination experience remains largely underexplored. This current research addresses this lacuna and empirically investigates the dimensions of tourists’ emotional experiences toward hedonic holiday destinations. Adopting a rigorous scale development procedure, exploratory and confirmatory factor analyses identify three salient dimensions to represent the Destination Emotion Scale, namely, joy, love, and positive surprise. In addition, tourists’ emotional experiences are related to satisfaction, which in turn has a significant influence on behavioral intentions. Findings offer important implications for destination marketers in relation to branding and emotional experience management.
Tourism-Receiving Countries in Connotative Google Space
Authors: Mazanec Josef A.
Published: October 2009

Emotion-carrying connotations are regarded as constituents of destination images. The connotative word items symptomatically associated with country names are likely to influence the emotional state and hence arousal level of Web users when browsing through tourism-related pages. The co-occurrence frequencies of connotative nouns and tourism-receiving country names in Web content serve as a basis for portraying the countries’ positions in connotative space. Transforming the raw frequencies into Normalized Google Distances makes them comparable. Automated data retrieval operates for the Web domain defined by “tourism OR tourist OR travel OR trip.” Visualizing the destination countries’ similarity in terms of Web-projected connotative profiles highlights one aspect of competitive threat. It is demonstrated with disjunctive and nondisjunctive hierarchical clustering, network analysis, and Sammon mapping.
Reachability analysis of multi-affine systems
Authors: Kloetzer Marius , Belta Calin
Published: October 2009

We present a computationally attractive technique to study the reachability of rectangular regions by trajectories of continuous multi-affine systems. The method is iterative. At each step, finer partitions and finite quotients that over-approximate the reachability properties of the initial system are produced. We exploit some convexity properties of multi-affine functions on rectangles to show that the construction of the quotient at each step requires only the evaluation of the vector field at the set of all vertices of all rectangles in the partition and finding the roots of a finite set of scalar affine functions. This methodology can be used for formal analysis of biochemical networks, aircraft and underwater vehicles, where multi-affine models are widely used.
A fuzzy Petri net-based reasoning method for rescheduling
Authors: Fei Qiao  , Qidi Wu  , Li Li  , Zuntong Wang  , Bin Shi
Published: October 2009

Because of the high possibility of uncertain production disturbances, an established optimized schedule may not keep its optimality or even feasibility. Production rescheduling, which gives attention to both optimal scheduling and dynamic scheduling, is proposed in this background. One of the most important issues in rescheduling research is the rescheduling strategy that refers to rescheduling start-up decision making and rescheduling methodology adoption. It is ill structured, and involves some fuzzy and random information. In order to solve it, a fuzzy Petri net model for rescheduling (FPN-R) is proposed. Based on it, a fuzzy reasoning approach for rescheduling decision-making is discussed. Finally, a case study from a wafer fabrication plant is used to show the application and feasibility of the proposed FPN-R model and reasoning approach.
Dynamic feedback tracking control of non-holonomic mobile robots with unknown camera parameters
Authors: Chaoli Wang  , Yingchun Mei  , Zhenying Liang  , Qingwei Jia
Published: October 2009

In this paper we investigate the tracking control of non-holonomic mobile robots with uncertainties. Non-holonomic kinematic systems with visual feedback are uncertain and more involved in comparison with common kinematic systems. Barbalat’s theorem and Lyapunov techniques are exploited to craft a dynamic feedback robust controller that enables tracking of the mobile robot configuration despite the lack of depth information and the lack of precise visual parameters. The most interesting feature of this paper is that the problem is discussed in the image frame and the inertial frame, which makes the problem easy and useful. The convergence of the error system by using the proposed method is proved rigorously. A simulation is given to show the effectiveness of the presented controllers.
Position error signal detection from the user sector for high position update rate in patterned media recording technology
Authors: Wai Ee Wong  , Songhua Zhang  , Kheong Sann Chan
Published: October 2009

Achievable high recording track density in hard disk drives (HDDs) is often limited by the servo performance and the presence of disturbances and instability in the HDDs’ structures. For better servo performance, the position error signal (PES) sampling rate should be increased, as it is closer to the corresponding continuous time controller. However, the fixed number of servo sectors within the embedded servo system and the spinning speed limits the upper bound for the PES sampling rate. In this paper, a new PES detection strategy through direct measurement of the head position from the frequency-encoded user data channel is proposed in order to increase measurement accuracy and position update rate, in particular for embedded servo systems. Having a higher sampling rate will be very crucial in order to achieve more than the 1600 kTPI required for the 10 terabits per square inch areal density targeted by the Information Storage Industry Consortium (INSIC). The ability to extract positioning information within the user data sector will allow accurate read back and assist in writing processes.
Expertise-Based Intuition and Decision Making in Organizations
Authors: Salas Eduardo , Rosen Michael A. , DiazGranados Deborah
Published: October 2009

There has been a growing popular fascination with how experts make rapid and effective decisions. This interest has been paralleled in various scientific research communities. Across these disciplinary boundaries, researchers have found that intuition plays a critical role in expert decision making. Therefore, an understanding of how experts develop and use intuition effectively within organizations has the potential to greatly influence organizational practices and effectiveness. The purpose of this review is to integrate the extant literature related to expertise-based intuition—intuition rooted in extensive experience within a specific domain—in decision making. To that end, this review addresses four specific goals. First, the authors review the scientific literature on expertise and intuition to define expertise-based intuition, the type of intuition of most value to organizations. Second, the authors propose a set of descriptive developmental and performance mechanisms of expertise-based intuition in decision making. Third, the authors discuss the multilevel nature of expertise-based intuition. Fourth, the authors propose future directions for research and application.
Does CO 2 flushing of the empty CPB circuit decrease the number of gaseous emboli in the prime?
Authors: Nyman J. , Rundby C. , Svenarud P. , van der Linden J.
Published: October 2009

Twenty (20) CPB-circuits were randomized to a CO2 group or a control group. In the CO 2 group, each circuit was flushed with CO2 (10L/min) at the top of the venous reservoir for 5 minutes, after which priming fluid was added without interruption of the CO2 inflow. Control group circuits were not flushed and contained air. A perfusionist, blinded to the study, started the pump (5L/min), ventilated the oxygenator (3L O2/min), and knocked on the oxygenator 20 times during the first and 14th minutes. Arterial line microemboli counts were registered with a Doppler for 15 minutes. In both groups, the median number of microemboli was highest during the first minute, 380.5 (288.75/422.25, 25th/75th percentile) counts in the control group versus 264.5 (171.75/422.25) counts in the CO 2 group (p=0.01). Throughout the experiment, the median microembolic count minute by minute in the CO2 group remained lower (p≤ 0 .004) than in the control group. Knocking on the reservoir (14th minute) increased the microemboli counts in both groups (p<0.01). The median values during the 15th minute were 15.5 and 0.5 in the control and the CO2 groups, respectively, which were 9% (15.5/173) and 0.5% (0.5/87), respectively, of the values registered after 14 minutes. In conclusion, CO 2 flushing of the empty circuit decreases the number of gaseous emboli in the prime compared with a conventional circuit that contains air before being primed with fluid. Knocking of the oxygenator releases gaseous emboli and the duration of re-circulating the circuit with prime influences the number of microemboli.
Platelet-Rich Plasma
Authors: Foster Timothy E. , Puskas Brian L. , Mandelbaum Bert R. , Gerhardt Michael B. , Rodeo Scott A.
Published: October 2009

Platelet-rich plasma (PRP) has been utilized in surgery for 2 decades; there has been a recent interest in the use of PRP for the treatment of sports-related injuries. PRP contains growth factors and bioactive proteins that influence the healing of tendon, ligament, muscle, and bone. This article examines the basic science of PRP, and it describes the current clinical applications in sports medicine. This study reviews and evaluates the human studies that have been published in the orthopaedic surgery and sports medicine literature. The use of PRP in amateur and professional sports is reviewed, and the regulation of PRP by antidoping agencies is discussed.
Use of Eight-node Curvilinear Domains in Discrete Singular Convolution Method for Free Vibration Analysis of Annular Sector Plates with Simply Supported Radial Edges
Authors: Civalek Ö.
Published: October 2009

Free vibration analysis of annular sector plate is studied using an eight-node curvilinear domain. The method of discrete singular convolution (DSC) is used for computations. Radial edges of plates are simply supported; however, various edge conditions are taken into account for circumferential edge. In the proposed approach, an irregular physical domain is transformed into a rectangular domain by using geometric coordinate transformation. The DSC procedures are then applied to discretization of the transformed set of governing equations and boundary conditions. The effects of mode numbers, vertex angle, boundary conditions and outer-to-inner radius ratio on the vibration frequencies are investigated. It is seen that the results obtained by DSC method shows very good agreement with that of other available analytical and numerical solutions for the plate problems under investigation.
Mathematical Theory of Autodriver for Autonomous Vehicles
Authors: Jazar Reza N.
Published: October 2009

Introducing an independent four-wheel-steering (4WS) system, we are able to design an autodriver to keep an autonomous vehicle on a given road. The kinematic condition of steering can be used to set the steer angles such that the kinematic center of rotation be at any desired point. The road and tire characteristics, along with the dynamics of a moving vehicle cause the vehicle to turn about an actual point that is not necessarily at the road curvature center. The position of the dynamic turning center can be controlled by adjusting the steer angles such that it coincides with the road curvature center. Such a vehicle will move on the desired road autonomously.
Command Shaping for Nonlinear Crane Dynamics
Authors: Blackburn D. , Singhose W. , Kitchen J. , Patrangenaru V. , Lawrence J. , Kamoi Tatsuaki , Taura Ayako
Published: October 2009

Motion-induced vibration can be greatly reduced by properly shaping the reference command. Input shaping is one type of reference shaping method that is based largely on linear superposition. In this paper we document the impact of nonlinear crane dynamics on the effectiveness of input shaping. As typical bridge cranes are driven using Cartesian motions, they behave nearly linearly for low- and moderate-velocity motions. On the other hand, the natural rotational motions of tower cranes make them more nonlinear. The nonlinear equations of motion for both bridge and tower cranes are presented and experimentally verified using two portable cranes. The effectiveness of input shaping on the near-linear bridge crane is explained. Then, a command-shaping algorithm is developed to improve vibration reduction during the more nonlinear slewing motions of the tower crane. Experimental results demonstrate the effectiveness of the proposed approach over a wide range of operating conditions.
Disordered aldosterone-volume relationship in end-stage kidney disease
Authors: Bomback Andrew S , Kshirsagar Abhijit V , Ferris Maria E , Klemmer Philip J
Published: October 2009

Introduction. Sodium loading, and subsequent volume expansion, suppresses aldosterone levels in individuals with normal renal function. We hypothesised that loss of renal function impairs this volume-aldosterone relationship.

Materials and methods. With multifrequency bioimpedance spectroscopy, we measured total body water (TBW), extracellular volume (ECV), and intracellular volume in five haemodialysis patients at varied states of hydration and in five healthy volunteers during low-, normal-, and high-salt diets. Serum aldosterone, potassium, and C-reactive protein were measured simultaneously. Scatterplots and general estimating equations were used to examine the relationship among these variables.

Results. In healthy volunteers with salt loading, and in haemodialysis subjects with increased inter-dialytic weight gain, expansion of ECV led to reciprocal declines in serum aldosterone concentrations. The relationship was more profound in healthy volunteers (p<0.001) than in haemodialysis subjects (p=0.1). Notably, haemodialysis subjects posted consistently higher levels of ECV (median 49.6% TBW, IQR 43.9—51.8% compared to 41.1%, 39.9—42.8% in volunteers) and serum aldosterone (median 26.7 ng/dl, IQR 19.8—29.6 compared to 12.4 ng/dl, 8.8—16.0 in volunteers). Serum potassium did not appear to influence aldosterone concentration (p=0.9).

Conclusions. The shift of the volume-aldosterone curve in haemodialysis subjects suggests that end-stage kidney disease is a state of high volume and inappropriately high aldosterone. These data have important clinical implications, as dialysis patients may benefit from both volume reduction and mineralocorticoid receptor blockade.
Metabolic syndrome, aging, physical inactivity, and incidence of type 2 diabetes in general African population
Authors: Longo-Mbenza B. , Kasiam Lasi On'kin JB , Nge Okwe A. , Kangola Kabangu N. , Mbungu Fuele S.
Published: October 2009

The first objective of this study was to determine the baseline prevalence of metabolic syndrome and its individual components using the NCEP-R/ATPIII criteria, IDF criteria for Europe, and IDF criteria for Africa: waist circumference of at least 94 cm for men and women. The second objective was to investigate the incidence and the determinants of type 2 diabetes in a prospective cohort of 807 non-diabetic Central Africans aged ≥ 40 years from December 2004 to September 2008. During 3,156 person-years of median follow up, there were 93 type 2 diabetes cases (11.5%), corresponding to an incidence of 29 (95% CI 15—43) per 1,000 person-years. The independent predictors of incident type 2 diabetes were age ≥ 45 years, physical inactivity, non-diabetic hyperglycaemia and metabolic syndrome regardless of criteria used. In conclusion, urgent prevention strategies are needed to curb the type 2 diabetes epidemic in Africa.
Cognitive Behavior Therapy and Worry Reduction in an Outpatient With Generalized Anxiety Disorder
Authors: Khodarahimi Siamak , Pole Nnamdi
Published: October 2009

This article describes the treatment of a 27-year-old female with a particularly challenging manifestation of generalized anxiety disorder (GAD) with prominent worry. A manualized cognitive—behavioral therapy (CBT) protocol, including problem-solving training, cognitive restructuring, and relaxation training techniques, was tailored to the patient’s presenting profile. Several self-report measures administered during the pretreatment, post-treatment, and follow-up periods, including: the Penn State Worry Questionnaire (PSWQ), the Why Worry-II (WW-II), the Ahwaz Worry Inventory (AWI), and the Intolerance of Uncertainty Scale (IUS), indicated significant worry reduction following treatment. Many difficulties were encountered, most notably designing and monitoring homework. Treatment implications are discussed.
Mta3-NuRD complex is a master regulator for initiation of primitive hematopoiesis in vertebrate embryos
Authors: Li Xiang , Jia Shunji , Wang Shaohe , Wang Yuemeng , Meng Anming
Published: October 2009

Metastasis-associated antigens 1/2/3 (Mta1/2/3) are components of nucleosome remodeling and deacetylase (NuRD) complexes and have been found to play roles in embryonic development and homeostasis. However, their functions in primitive hematopoiesis are unknown. In this study, we demonstrate that knockdown of mta3 by antisense morpholinos abolishes primitive hematopoietic lineages and causes abnormal angiogenesis in zebrafish embryos. However, the expression of the pronephric duct and paraxial mesoderm markers is unaltered and the specification of angioblasts is unaffected in mta3 morphants. The results suggest that mta3 is specifically required for primitive hematopoiesis. Furthermore, inhibition of deacetylase activity with the inhibitors valproic acid (VPA) or trichostatin A (TSA) in zebrafish embryos completely blocks primitive hematopoiesis, resulting in hematopoietic defects almost identical to those seen in mta3 morphants. Importantly, overexpression of scl or scl and lmo2, 2 master genes for primitive hematopoiesis, is able to overturn effects of mta3 knockdown or VPA/TSA treatment; and overexpression of mta3, and human MBD3 or HDAC1, 2 other components of NuRD complex, enhances the expression of scl and lmo2 in the posterior lateral plate mesoderm during early primitive hematopoiesis. We conclude that Mta3-NuRD complex is essential for the initiation of primitive hematopoiesis. Thus, our findings provide new insight into the regulatory hierarchy of primitive hematopoiesis in vertebrates.
Editorial: Liver X receptor α (LXRα) as a therapeutic target in chronic lymphocytic leukemia (CLL)
Authors: Christopherson Kent W. , Landay Alan
Published: October 2009

The potential application of LXR agonists as negative regulators of proliferation and survival of B-cells from CLL patients is discussed.
A laboratory study of NMR relaxation times and pore coupling in heterogeneous media
Authors: Grunewald Elliot , Knight Rosemary
Published: October 2009

Nuclear magnetic resonance (NMR) relaxation times of geologic materials are closely related to pore geometry. In heterogeneous media, however, the details of this relationship are poorly understood because of a phenomenon known as pore coupling, which arises when diffusing protons sample multiple pores before relaxing. Laboratory experiments allow us to explore whether surface geochemistry can influence pore coupling and how this process affects the observed relaxation-time distribution. Measurements of the NMR response for microporous silica gel packs, treated with varying amounts of surface-coating iron, demonstrate that samples with less iron exhibit stronger pore coupling than those with abundant iron. When pore coupling is strong, the relaxation-time distribution grossly misrepresents the underlying bimodal pore-size distribution of micropores and macropores. Specifically, the bimodal relaxation-time distribution becomes merged and the relative amplitude of the peaks fails to reflect the true macropore and micropore volume. A reduction in pore coupling, observed with increasing iron content, is attributed to a decrease in the distance protons are able to diffuse before relaxing. Basic parameters describing the shape of the relaxation-time distributions for this range of samples are well-predicted by a 1D analytical model. Experimental results conclusively demonstrate that surface geochemistry is an important factor determining the degree to which pore coupling occurs and illustrate how this phenomenon can affect the interpretation of NMR relaxation measurements in heterogeneous porous media.
Intellectual Property
Authors: Walker David A.
Published: October 2009

The Intellectual Property department in each issue of Geophysics provides U.S. patent abstracts, published patent abstracts of U.S. patent applications, and published abstracts filed under the Patent Cooperation Treaty (PCT).