bluuebunny/crossref_metadata_2025 huggingface dataset:
Role for stress fiber contraction in surface tension development and stretch-activated channel regulation in C2C12 myoblasts
Authors: Sbrana Francesca , Sassoli Chiara , Meacci Elisabetta , Nosi Daniele , Squecco Roberta , Paternostro Ferdinando , Tiribilli Bruno , Zecchi-Orlandini Sandra , Francini Fabio , Formigli Lucia
Published: May 2008

Membrane-cytoskeleton interaction regulates transmembrane currents through stretch-activated channels (SACs); however, the mechanisms involved have not been tested in living cells. We combined atomic force microscopy, confocal immunofluorescence, and patch-clamp analysis to show that stress fibers (SFs) in C2C12 myoblasts behave as cables that, tensed by myosin II motor, activate SACs by modifying the topography and the viscoelastic (Young's modulus and hysteresis) and electrical passive (membrane capacitance, Cm) properties of the cell surface. Stimulation with sphingosine 1-phosphate to elicit SF formation, the inhibition of Rho-dependent SF formation by Y-27632 and of myosin II-driven SF contraction by blebbistatin, showed that not SF polymerization alone but the generation of tensional forces by SF contraction were involved in the stiffness response of the cell surface. Notably, this event was associated with a significant reduction in the amplitude of the cytoskeleton-mediated corrugations in the cell surface topography, suggesting a contribution of SF contraction to plasma membrane stretching. Moreover, Cm, used as an index of cell surface area, showed a linear inverse relationship with cell stiffness, indicating participation of the actin cytoskeleton in plasma membrane remodeling and the ability of SF formation to cause internalization of plasma membrane patches to reduce Cm and increase membrane tension. SF contraction also increased hysteresis. Together, these data provide the first experimental evidence for a crucial role of SF contraction in SAC activation. The related changes in cell viscosity may prevent SAC from abnormal activation.
Mouse Ae1 E699Q mediates SO42−i/aniono exchange with [SO42−]i-dependent reversal of wild-type pHo sensitivity
Authors: Chernova Marina N. , Stewart Andrew K. , Barry Parul N. , Jennings Michael L. , Alper Seth L.
Published: May 2008

The SLC4A1/AE1 gene encodes the electroneutral Cl−/HCO3− exchanger of erythrocytes and renal type A intercalated cells. AE1 mutations cause familial spherocytic and stomatocytic anemias, ovalocytosis, and distal renal tubular acidosis. The mutant mouse Ae1 polypeptide E699Q expressed in Xenopus oocytes cannot mediate Cl−/HCO3− exchange or 36Cl− efflux but exhibits enhanced dual sulfate efflux mechanisms: electroneutral exchange of intracellular sulfate for extracellular sulfate (SO42−i/SO42−o exchange), and electrogenic exchange of intracellular sulfate for extracellular chloride (SO42−i/Cl−o exchange). Whereas wild-type AE1 mediates 1:1 H+/SO42− cotransport in exchange for either Cl− or for the H+/SO42− ion pair, mutant Ae1 E699Q transports sulfate without cotransport of protons, similar to human erythrocyte AE1 in which the corresponding E681 carboxylate has been chemically converted to the alcohol (hAE1 E681OH). We now show that in contrast to the normal cis-stimulation by protons of wild-type AE1-mediated SO42− transport, both SO42−i/Cl−o exchange and SO42−i/SO42−o exchange mediated by mutant Ae1 E699Q are inhibited by acidic pHo and activated by alkaline pHo. hAE1 E681OH displays a similarly altered pHo dependence of SO42−i/Cl−o exchange. Elevated [SO42−]i increases the K1/2 of Ae1 E699Q for both extracellular Cl− and SO42−, while reducing inhibition of both exchange mechanisms by acid pHo. The E699Q mutation also leads to increased potency of self-inhibition by extracellular SO42−. Study of the Ae1 E699Q mutation has revealed the existence of a novel pH-regulatory site of the Ae1 polypeptide and should continue to provide valuable paths toward understanding substrate selectivity and self-inhibition in SLC4 anion transporters.
Comparative study of ezrin phosphorylation among different tissues: more is good; too much is bad
Authors: Zhu Lixin , Hatakeyama Jason , Chen Cheng , Shastri Aditi , Poon Kevin , Forte John G.
Published: May 2008

In a comparison of three different tissues, the membrane cytoskeleton linker protein ezrin was found to assume high levels of phosphorylation on threonine-567 (T567) in the brush border membranes of renal proximal tubule cells and small intestine enterocytes, in contrast to the apical canalicular membrane of gastric parietal cells. Together with an earlier observation that increased T567 phosphorylation is associated with more elaborate microvilli in parietal cells, this comparative study suggested a higher phosphorylation level requirement for the denser and more uniform distribution of microvilli at brush border surfaces. Using a kinase inhibitor, staurosporin, and metabolic inhibitor, sodium azide, relatively high turnover of ezrin T567 phosphorylation was observed in all three epithelia. Aiming to understand the role of phosphorylation turnover in these tissues, detergent extraction analysis of gastric glands and proximal tubules revealed that an increased phosphorylation on ezrin T567 greatly enhanced its association with F-actin, while ezrin-membrane interaction persisted regardless of the changes of phosphorylation level on ezrin T567. Finally, expression of Thr567Asp mutant ezrin, which mimics the phospho-ezrin state but does not allow turnover, caused aberrant growth of membrane projections in cultured proximal tubule cells, consistent with what had previously been observed in several cell lines and gastric parietal cells. These results fit into a model of surface plasticity, which posits that the turnover of phosphorylation on T567 empowers ezrin to relax and reposition membrane to the underlying cytoskeleton under varying conditions of filament growth or rapid membrane expansion (or depletion).
Hormonal and metabolic rhythms associated with the daily scheduled nursing in rabbit pups
Authors: Morgado Elvira , Gordon M. Kathleen , del Carmen Miñana-Solis María , Meza Enrique , Levine Seymour , Escobar Carolina , Caba Mario
Published: May 2008

Young rabbits are nursed every 24 h for a period of 3–5 min. As a consequence, pups are synchronized to this nursing event; this synchronization is characterized by increased locomotor activity and a peaking of core temperature and plasma corticosterone in anticipation of the daily meal. Ghrelin is a hormone suggested to play a role in meal initiation and to promote food intake. The present study explored the role of ghrelin in food-entrained conditions. Newborn rabbits were maintained in constant darkness and nursed once daily at 1000 by the lactating dam. On postnatal day 7, rabbits were killed at six different time points to complete a 24-h cycle. All pups developed locomotor rhythms entrained by mealtime and exhibited anticipatory activity. Food-entrained rhythms in plasma corticosterone and free fatty acids were observed even if two meals were omitted. In contrast, daily food-driven rhythms in stomach weight, plasma glucose, liver glycogen, and ghrelin did not persist when two meals were omitted. Peak ghrelin levels were observed at the moment in the cycle when the stomach weight was lowest, i.e., before initiation of anticipation. The present data are in agreement with previous data from rabbit pups maintained in light-dark conditions and provide evidence that 7- to 9-day-old rabbits in constant darkness can exhibit metabolic and hormonal rhythms mainly driven by the restricted daily nursing.
Modulation of the cough reflex by antitussive agents within the caudal aspect of the nucleus tractus solitarii in the rabbit
Authors: Mutolo Donatella , Bongianni Fulvia , Cinelli Elenia , Fontana Giovanni A. , Pantaleo Tito
Published: May 2008

We have previously shown that ionotropic glutamate receptors in the caudal portion of the nucleus tractus solitarii (NTS), especially in the commissural NTS, play a prominent role in the mediation of tracheobronchial cough and that substance P potentiates this reflex. This NTS region could be a site of action of some centrally acting antitussive agents and a component of a drug-sensitive gating mechanism of cough. To address these issues, we investigated changes in baseline respiratory activity and cough responses to tracheobronchial mechanical stimulation following microinjections (30–50 nl) of centrally acting antitussive drugs into the caudal NTS of pentobarbitone-anesthetized, spontaneously breathing rabbits. [d-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (DAMGO) and baclofen decreased baseline respiratory frequency because of increases in the inspiratory time only at the higher concentration employed (5 mM and 1 mM, respectively). DAMGO (0.5 mM) and baclofen (0.1 mM) significantly decreased cough number, peak abdominal activity, peak tracheal pressure, and increased cough-related total cycle duration. At the higher concentrations, these agents suppressed the cough reflex. The effects of these two drugs were counteracted by specific antagonists (10 mM naloxone and 25 mM CGP-35348, respectively). The neurokinin-1 (NK1) receptor antagonist CP-99,994 (10 mM) abolished cough responses, whereas the NK2receptor antagonist MEN 10376 (5 mM) had no effect. The results indicate that the caudal NTS is a site of action of some centrally acting drugs and a likely component of a neural system involved in cough regulation. A crucial role of substance P release in the mediation of reflex cough is also suggested.
Tea catechin ingestion combined with habitual exercise suppresses the aging-associated decline in physical performance in senescence-accelerated mice
Authors: Murase Takatoshi , Haramizu Satoshi , Ota Noriyasu , Hase Tadashi
Published: May 2008

Catechins, which are abundant in green tea, possess a variety of biologic actions, and their clinical application has been extensively investigated. In this study, we examined the effects of tea catechins and regular exercise on the aging-associated decline in physical performance in senescence-accelerated prone mice (SAMP1) and age-matched senescence-accelerated resistant mice (SAMR1). The endurance capacity of SAMR1 mice, measured as the running time to exhaustion, tended to increase over the 8-wk experimental period, whereas that of SAMP1 mice decreased by 17%. On the other hand, the endurance capacity of SAMP1 mice fed 0.35% (wt/wt) catechins remained at the initial level and was significantly higher than that of SAMP1 mice not fed catechins. In SAMP1 mice fed catechins and given exercise, oxygen consumption was significantly increased, and there was an increase in skeletal muscle fatty acid β-oxidation. The mRNA levels of mitochondria-related molecules, such as peroxisome proliferator-activated receptor-γ coactivator-1, cytochrome c oxidase-II, III, and IV in skeletal muscle were also higher in SAMP1 mice given both catechins and exercise. Moreover, oxidative stress measured as thiobarbituric reactive substances was lower in SAMP1 groups fed catechins than in the SAMP1 control group. These results suggest that long-term intake of catechins, together with habitual exercise, is beneficial for suppressing the aging-related decline in physical performance and energy metabolism and that these effects are due, at least in part, to improved mitochondrial function in skeletal muscle.
Nephrin binds to the COOH terminus of a large-conductance Ca2+-activated K+ channel isoform and regulates its expression on the cell surface
Authors: Kim Eun Young , Choi Kyoung-Jae , Dryer Stuart E.
Published: May 2008

We carried out a yeast two-hybrid screen to identify proteins that interact with large-conductance Ca2+-activated K+ (BKCa) channels encoded by the Slo1 gene. Nephrin, an essential adhesion and scaffolding molecule expressed in podocytes, emerged in this screen. The Slo1-nephrin interaction was confirmed by coimmunoprecipitation from the brain and kidney, from HEK-293T cells expressing both proteins, and by glutathione S-transferase pull-down assays. We detected nephrin binding to the Slo1VEDEC splice variant, which is typically retained in intracellular stores, and to the β4-subunit. However, we did not detect significant binding of nephrin to the Slo1QEERL or Slo1EMVYR splice variants. Coexpression of nephrin with Slo1VEDEC increased expression of functional BKCa channels on the surface of HEK-293T cells but did not affect steady-state surface expression of the other COOH-terminal Slo1 variants. Nephrin did not affect the kinetics or voltage dependence of channel activation in HEK-293T cells expressing Slo1. Stimulation of Slo1VEDEC surface expression in HEK-293T cells was also observed by coexpressing a small construct encoding only the distal COOH-terminal domains of nephrin that interact with Slo1. Reduction of endogenous nephrin expression by application of small interfering RNA to differentiated cells of an immortalized podocyte cell line markedly reduced the steady-state surface expression of Slo1 as assessed by electrophysiology and cell-surface biotinylation assays. Nephrin therefore plays a role in organizing the surface expression of ion channel proteins in podocytes and may play a role in outside-in signaling to allow podocytes to adapt to mechanical or neurohumoral stimuli originating in neighboring cells.
Upregulation of apical sodium-chloride cotransporter and basolateral chloride channels is responsible for the maintenance of salt-sensitive hypertension
Authors: Capasso Giovambattista , Rizzo Maria , Garavaglia Maria Lisa , Trepiccione Francesco , Zacchia Miriam , Mugione Alessandra , Ferrari Patrizia , Paulmichl Markus , Lang Florian , Loffing Johannes , Carrel Monique , Damiano Sara , Wagner Carsten A. , Bianchi Giuseppe , Meyer Giuliano
Published: May 2008

We investigated which of the NaCl transporters are involved in the maintenance of salt-sensitive hypertension. Milan hypertensive (MHS) rats were studied 3 mo after birth. In MHS, compared with normotensive strain (MNS), mRNA abundance, quantified by competitive PCR on isolated tubules, was unchanged, both for Na+/H+isoform 3 (NHE3) and Na+-K+-2Cl−(NKCC2), but higher (119%, n = 5, P < 0.005) for Na+-Cl−(NCC) in distal convoluted tubules (DCT). These results were confirmed by Western blots, which revealed: 1) unchanged NHE3 in the cortex and NKCC2 in the outer medulla; 2) a significant increase (52%, n = 6, P < 0.001) of NCC in the cortex; 3) α- and β-sodium channels [epithelial Na+channel (ENaC)] unaffected in renal cortex and slightly reduced in the outer medulla, while γ-ENaC remained unchanged. Pendrin protein expression was unaffected. The role of NCC was reinforced by immunocytochemical studies showing increased NCC on the apical membrane of DCT cells of MHS animals, and by clearance experiments demonstrating a larger sensitivity ( P < 0.001) to bendroflumethiazide in MHS rats. Kidney-specific chloride channels (ClC-K) were studied by Western blot experiments on renal cortex and by patch-clamp studies on primary culture of DCT dissected from MNS and MHS animals. Electrophysiological characteristics of ClC-K channels were unchanged in MHS rats, but the number of active channels in a patch was 0.60 ± 0.21 ( n = 35) in MNS rats and 2.17 ± 0.59 ( n = 23) in MHS rats ( P < 0.05). The data indicate that, in salt-sensitive hypertension, there is a strong upregulation, both of NCC and ClC-K along the DCT, which explains the persistence of hypertension.
Inhibitory Network Interactions Shape the Auditory Processing of Natural Communication Signals in the Songbird Auditory Forebrain
Authors: Pinaud Raphael , Terleph Thomas A. , Tremere Liisa A. , Phan Mimi L. , Dagostin André A. , Leão Ricardo M. , Mello Claudio V. , Vicario David S.
Published: May 2008

The role of GABA in the central processing of complex auditory signals is not fully understood. We have studied the involvement of GABAA-mediated inhibition in the processing of birdsong, a learned vocal communication signal requiring intact hearing for its development and maintenance. We focused on caudomedial nidopallium (NCM), an area analogous to parts of the mammalian auditory cortex with selective responses to birdsong. We present evidence that GABAA-mediated inhibition plays a pronounced role in NCM's auditory processing of birdsong. Using immunocytochemistry, we show that approximately half of NCM's neurons are GABAergic. Whole cell patch-clamp recordings in a slice preparation demonstrate that, at rest, spontaneously active GABAergic synapses inhibit excitatory inputs onto NCM neurons via GABAAreceptors. Multi-electrode electrophysiological recordings in awake birds show that local blockade of GABAA-mediated inhibition in NCM markedly affects the temporal pattern of song-evoked responses in NCM without modifications in frequency tuning. Surprisingly, this blockade increases the phasic and largely suppresses the tonic response component, reflecting dynamic relationships of inhibitory networks that could include disinhibition. Thus processing of learned natural communication sounds in songbirds, and possibly other vocal learners, may depend on complex interactions of inhibitory networks.
Synergistic Effects of D1/5 and 5-HT1A/7 Receptor Agonists on Locomotor Movement Induction in Complete Spinal Cord–Transected Mice
Authors: Lapointe Nicolas P. , Guertin Pierre A.
Published: May 2008

Monoamines are well known to modulate locomotion in several vertebrate species. Coapplication of dopamine (DA) and serotonin (5-HT) has also been shown to potently induce fictive locomotor rhythms in isolated spinal cord preparations. However, a synergistic contribution of these monoamines to locomotor rhythmogenesis in vivo has never been examined. Here, we characterized the effects induced by selective DA and 5-HT receptor agonists on hindlimb movement induction in completely spinal cord transected (adult) mice. Administration of the lowest effective doses of SKF-81297 (D1/5 agonist, 1–2 mg/kg, ip) or 8-OH-DPAT (5-HT1A/7 agonist, 0.5 mg/kg, ip) acutely elicited some locomotor-like movements (LM) (5.85 ± 1.22 and 3.67 ± 1.44 LM/min, respectively). Coadministration of the same doses of SKF-81297 and 8-OH-DPAT led to a significant increase (7- to 10-fold) of LM (37.70 ± 5.01 LM/min). Weight-bearing and plantar foot placement capabilities were also found with the combination treatment only (i.e., with no assistance or other forms of stimulation). These results clearly show that D1/5 and 5-HT1A/7 receptor agonists can synergistically activate spinal locomotor networks and thus generate powerful basic stepping movements in complete paraplegic animals. Although previous work from this laboratory has reported the partial rhythmogenic potential of monoamines in vivo, the present study shows that drug combinations such as SKF-81297 and 8-OH-DPAT can elicit weight-bearing stepping.
Real-Time and Secure Wireless Health Monitoring
Authors: Dağtaş S. , Pekhteryev G. , Şahinoğlu Z. , Çam H. , Challa N.
Published: May 2008

We present a framework for a wireless health monitoring system using wireless networks such as ZigBee. Vital signals are collected and processed using a 3-tiered architecture. The first stage is the mobile device carried on the body that runs a number of wired and wireless probes. This device is also designed to perform some basic processing such as the heart rate and fatal failure detection. At the second stage, further processing is performed by a local server using the raw data transmitted by the mobile device continuously. The raw data is also stored at this server. The processed data as well as the analysis results are then transmitted to the service provider center for diagnostic reviews as well as storage. The main advantages of the proposed framework are (1) the ability to detect signals wirelessly within a body sensor network (BSN), (2) low-power and reliable data transmission through ZigBee network nodes, (3) secure transmission of medical data over BSN, (4) efficient channel allocation for medical data transmission over wireless networks, and (5) optimized analysis of data using an adaptive architecture that maximizes the utility of processing and computational capacity at each platform.
Synthesis of Nanometer‐Sized WO3 Particles by Facile Wet Process and Their Photocatalytic Properties
Authors: Iwasaki Mitsunobu , Park Won-kyu
Published: May 2008

Nanometer‐sized WO3 particles were prepared from alkaline alcohol‐water mixture with WCI6 and NH3 under reflux. The resultant particles at various NH3/W mole ratios were well crystallized ranging 5–20 nm in diameter and the surface area was in the range of 13.70–32.50 m2g−1. Samples synthesized at NH3/W = 3.2 and 12.9 ratio (mol/mol) had an absorption edge in the visible light range and showed the photocatalytic activity under the irradiation of visible light, and the surface area and the crystallinity of those powders had a strong effect on the photocatalytic degradation. When ln(C0/C)(C0: initial concentration of acetaldehyde, C: final concentration of acetaldehyde after irradiation) was plotted against photoirradiation time, the degradation velocity constant (k) against acetaldehyde estimated from the slope of lines was 12.4 h−1g−1 at NH3/W = 3.2 and 13.9 h−1g−1 at NH3/W = 12.9 ratio (mol/mol), respectively.
A Comparison of Genetic Programming with Genetic Algorithms for Wire Antenna Design
Authors: Williams P. J. , Molteno T. C. A.
Published: May 2008

This work compares the performance of genetic
programming (GP) against traditional fixed‐length
genome GA approaches on the optimization of wire
antenna designs. We describe the implementation of
a GP electromagnetic optimization system for wire
structures. The results are compared with the traditional
GA approach. Although the dimensionality
of the search space is much higher for GP than GA,
we find that the GP approach gives better results
than GA for the same computational effort. In addition,
we find that a more expressive antenna structure
grammar, dramatically, improves the performance of
the GP approach.
Dual Feed, Single Element Antenna for WiMAX MIMO Application
Authors: Caimi Frank M. , Mongomery Mark
Published: May 2008

A novel u‐shaped single element antenna having two feed ports is compared with two equal length monopoles separated by a distance equivalent to the width. A discussion of relative performance metrics is provided for MIMO applications, and measured data is given for comparison. Good impedance match and isolation of greater than −10 dB are observed over the operating bandwidth from 2.3 to 2.39 GHz. The antenna patterns are highly uncorrelated, as illustrated by computation of the antenna pattern correlation coefficient for the two comparison monopoles.
Hybrid Silicon Photonics for Low‐Cost High‐Bandwidth Link Applications
Authors: Luff B. Jonathan , Feng Dazeng , Lee Daniel C. , Qian Wei , Liang Hong , Asghari Mehdi
Published: May 2008

Current discrete optical solutions for high data‐rate link applications, even with potentially high manufacturing volumes, are too costly. Highly integrated, multifunction modules are a key part of the solution, reducing size and cost while providing improved reliability. Silicon, with its proven manufacturability and reliability, offers a solid foundation for building a cost‐efficient path to successful products. In this paper, recent work on the development of silicon photonic enabling components for multichannel high data‐rate links is presented.
Ultrashort Laser Pulse Heating of Nanoparticles: Comparison of Theoretical Approaches
Authors: Letfullin Renat R. , George Thomas F. , Duree Galen C. , Bollinger Brett M.
Published: May 2008

The interaction between nanoparticles and ultrashort laser pulses holds great interest in laser nanomedicine, introducing such possibilities as selective cell targeting to create highly localized cell damage. Two models are studied to describe the laser pulse interaction with nanoparticles in the femtosecond, picosecond, and nanosecond regimes. The first is a two‐temperature model using two coupled diffusion equations: one describing the heat conduction of electrons, and the other that of the lattice. The second model is a one‐temperature model utilizing a heat diffusion equation for the phonon subsystem and applying a uniform heating approximation throughout the particle volume. A comparison of the two modeling strategies shows that the two‐temperature model gives a good approximation for the femtosecond mode, but fails to accurately describe the laser heating for longer pulses. On the contrary, the simpler one‐temperature model provides an adequate description of the laser heating of nanoparticles in the femtosecond, picosecond, and nanosecond modes.
Generalized Load Sharing for Homogeneous Networks of Distributed Environment
Authors: Satheesh A. , Kumar K. Vimal , Krishnaveni S.
Published: May 2008

We propose a method for job migration policies by considering effective usage of global memory
in addition to CPU load sharing in distributed systems. When a node is identified for lacking
sufficient memory space to serve jobs, one or more jobs of the node will be migrated to remote
nodes with low memory allocations. If the memory space is sufficiently large, the jobs will be
scheduled by a CPU‐based load sharing policy. Following the principle of sharing both CPU and
memory resources, we present several load sharing alternatives. Our objective is to reduce the
number of page faults caused by unbalanced memory allocations for jobs among distributed
nodes, so that overall performance of a distributed system can be significantly improved. We have
conducted trace‐driven simulations to compare CPU‐based load sharing policies with our policies.
We show that our load sharing policies not only improve performance of memory bound jobs, but
also maintain the same load sharing quality as the CPU‐based policies for CPU‐bound jobs. Regarding
remote execution and preemptive migration strategies, our experiments indicate that a strategy
selection in load sharing is dependent on the amount of memory demand of jobs, remote
execution is more effective for memory‐bound jobs, and preemptive migration is more effective for
CPU‐bound jobs. Our CPU‐memory‐based policy using either high performance or high throughput
approach and using the remote execution strategy performs the best for both CPU‐bound and
memory‐bound job in homogeneous networks of distributed environment.
SBWR Model for Steady-State and Transient Analysis
Authors: Espinosa-Paredes Gilberto , Nuñez-Carrera Alejandro
Published: May 2008

This paper presents a model of a simplified boiling water reactor (SBWR) to analyze the steady-state and transient behavior. The SBWR model is based on approximations of lumped and distributed parameters to consider neutronics and natural circulation processes. The main components of the model are vessel dome, downcomer, lower plenum, core (channel and fuel), upper plenum, pressure, and level controls. Further consideration of the model is the natural circulation path in the internal circuit of the reactor, which governs the safety performance of the SBWR. To demonstrate the applicability of the model, the predictions were compared with plant data, manufacturer_s predictions, and RELAP5 under steady-state and transient conditions of a typical BWR. In steady-state conditions, the profiles of the main variables of the SBWR core such as superficial velocity, void fraction, temperatures, and convective heat transfer coefficient are presented and analyzed. The transient behavior of SBWR was analyzed during the closure of all main steam line isolation valves (MSIVs). Our results in this transient show that the cooling system due to natural circulation in the SBWR is around 70% of the rated core flow. According to the results shown here, one of the main conclusions of this work is that the simplified model could be very helpful in the licensing process.
Development of a Novel Contactless Mechanocardiograph Device
Authors: Tavakolian Kouhyar , Zadeh Faranak M. , Chuo Yindar , Vaseghi Ali , Kaminska Bozena
Published: May 2008

A novel method of detecting mechanical movement of the heart, Mechanocardiography (MCG), with no connection to the subject's body is presented. This measurement is based on radar technology and it has been proven through this research work that the acquired signal is highly correlated to the phonocardiograph signal and acceleration-based ballistocardiograph signal (BCG) recorded directly from the sternum. The heart rate and respiration rate have been extracted from the acquired signal as two possible physiological monitoring applications of the radar-based MCG device.
Frequency of Certain Established Risk Factors in Soft Tissue Sarcomas in Adults: A Prospective Descriptive Study of 658 Cases
Authors: Penel Nicolas , Grosjean Jessica , Robin Yves Marie , Vanseymortier Luc , Clisant Stéphanie , Adenis Antoine
Published: May 2008

Soft tissue sarcomas are rare tumours with infrequent identified aetiological factors. Several genetic syndromes as well as previous radiation therapy and/or chronic lymphoedema have been suspected to predispose to some soft tissue sarcomas. Between January 1997 and September 2005, we carried out a prospective descriptive study to estimate the frequency of some particular etiological factors among 658 patients with soft tissue sarcomas. Sarcomas associated with a clinically identified genetic disease represent 2.8% out of all cases (95%CI: 1.5–3.8%). Most of these cases (14/19) are related to Recklinghausen neurofibromatosis. Radiation-induced sarcomas represent 3.3% out of all cases (95%CI: 1.7–5.1%). Most of these cases (9/22) are related to prior breast cancer treatment. We had observed only 1 case of Stewart-Treves syndrome. Liposarcoma, the most frequent histological subtype observed, is not associated with any particular aetiological entity. Finally, most of the adult soft tissue sarcomas are not related to any classical clinically identified genetic disease or previous radiation therapy and/or chronic lymphoedema risk factors. Frequency of underlying genetic syndrome which may predispose to soft tissue sarcomas could be higher than previously reported.
The Crystal Water Affect in the Interaction between the Tenebrio Molitor Alpha‐Amylase and Its Inhibitor
Authors: Zhi-Fei Zhu , Ting-Ting Ning , Zu-Min Xu , Ge-Xin Zhang , Yan-He Ma
Published: May 2008

Molecular dynamics simulation of the interaction between the Tenebrio molitor alpha‐amylase and its inhibitor at different proportion of crystal water was carried out with OPLS force field by hyperchem 7.5 software. In the correlative study, the optimal temperature of wheat monomeric and dimeric protein inhibitors was from 273 K to 318 K. The the average temperature of experimentation is 289 K. (1) The optimal temperature of interaction between alpha‐amylase and its inhibitors was 280 K without crystal water that was close to the results of experimentation. The forming of enzyme‐water and inhibitor‐water was easy, but incorporating third monomer was impossible. (2) Having analyzed the potential energy data, the optimal temperature of interaction energy between alpha‐amylase and its inhibitors covering 9 : 1, 5 : 5, 4 : 6, and 1 : 9 proportion crystal water was 290 K. (3) We compared the correlative QSAR properties. The proportion of crystal water was close to the data of polarizability (12.4%) in the QSAR properties. The optimal temperature was 280 K. This result was close to 289 K. These findings have theoretical and practical implications.
A Role for PPARβ/δ in Tumor Stroma and Tumorigenesis
Authors: Müller Rolf , Kömhoff Martin , Peters Jeffrey M. , Müller-Brüsselbach Sabine
Published: May 2008

Peroxisome proliferator‐activated receptor‐β/δ (PPARβ/δ) is a transcription factor that is activated by endogenous fatty acid ligands and by synthetic agonists. Its role in the regulation of skeletal muscle fatty acid catabolism, glucose homeostasis, and cellular differentiation has been established in multiple studies. On the contrary, a role for PPARβ/δ in tumorigenesis is less clear because there are contradictory reports in the literature. However, the majority of these studies have not examined the role of PPARβ/δ in the tumor stroma. Recent evidence suggests that stromal PPARβ/δ regulates tumor endothelial cell proliferation and promotes differentiation leading to the properly orchestrated events required for tumor blood vessel formation. This review briefly summarizes the significance of these studies that may provide clues to help explain the reported discrepancies in the literature regarding the role of PPARβ/δ in tumorigenesis.
Euler Numbers and Polynomials Associated with Zeta Functions
Authors: Kim Taekyun
Published: May 2008

For s ∈ ℂ, the Euler zeta function and the Hurwitz‐type Euler zeta
function are defined by , and . Thus, we note that the Euler zeta functions are entire functions in whole complex s‐plane, and these zeta functions have the values of the Euler numbers or the Euler
polynomials at negative integers. That is, , and . We give some interesting identities between the Euler numbers and the zeta functions. Finally, we will give the new values of the Euler zeta function at positive even integers.
Experimental and Numerical Modeling of Screws Used for Rigid Internal Fixation of Mandibular Fractures
Authors: Chaudhary Naresh , Lovald Scott T. , Wagner Jon , Khraishi Tariq , Baack Bret
Published: May 2008

Experimental and numerical methods are used to explore the stresses generated around bone screws used in rigid internal fixation of mandibular fractures. These results are intended to aid in decisions concerning both the design and the use of these bone screws. A finite element (FE) model of a human mandible is created with a fixated fracture in the parasymphyseal region. The mandibular model is anatomically loaded, and the forces exerted by the fixation plate onto the simplified screws are obtained and transferred to another finite element submodel of a screw implant embedded in a trilaminate block with material properties of cortical and cancellous bone. The stress in the bone surrounding the screw implant is obtained and compared for different screw configurations. The submodel analyses are further compared to and validated with simple axial experimental and numerical screw pull‐out models. Results of the screw FE analysis (FEA) submodel show that a unicortical screw of 2.6 mm major diameter and 1.0 mm pitch will cause less bone damage than a bicortical screw of 2.3 mm major diameter and 1.0 mm pitch. The results of this study suggest that bicortical drilling can be avoided by using screws of a larger major diameter.
A Strong Limit Theorem for Functions of Continuous Random Variables and an Extension of the Shannon‐McMillan Theorem
Authors: Li Gaorong , Chen Shuang , Feng Sanying
Published: May 2008

By means of the notion of likelihood ratio, the limit properties of the sequences of arbitrary‐dependent continuous random variables are studied, and a kind of strong limit theorems represented by inequalities with random bounds for functions of continuous random variables is established. The Shannon‐McMillan theorem is extended to the case of arbitrary continuous information sources. In the proof, an analytic technique, the tools of Laplace transform, and moment generating functions to study the strong limit theorems are applied.
A High‐Throughput Random Access Protocol for Multiuser MIMO Systems
Authors: Guo Haiyou , Hu Honglin , Zhang Yan
Published: May 2008

We propose a high‐throughput random access protocol for 2 × 2 multiuser multiple‐input multiple‐output (MIMO) systems. The cross‐layer mechanism utilizes the packets combining technique to exploit the advantages of both spatial multiplexing and multipacket reception. Analytical result indicates that the proposed scheme achieves 0.669 per spatial degree of freedom in stable throughput, which is much higher than those in the existed studies.
Data and Pilot Combining for Composite GNSS Signal Acquisition
Authors: Borio Daniele , Lo Presti Letizia
Published: May 2008

With the advent of new global navigation satellite systems (GNSS), such as the European Galileo, the
Chinese Compass and the modernized GPS, the presence of new modulations allows the use of special
techniques specifically tailored to acquire and track the new signals. Of particular interest are the new
composite GNSS signals that will consist of two different components, the data and pilot channels. Two
strategies for the joint acquisition of the data and pilot components are compared. The first technique,
noncoherent combining, is from the literature and it is used as a comparison term, whereas the analysis
of the second one, coherent combining with sign recovery, represents the innovative contribution of this
paper. Although the analysis is developed with respect to the Galileo E1 Open Service (OS) modulation,
the obtained results are general and can be applied to other GNSS signals.
On Using Curvature to Demonstrate Stability
Authors: McCluskey C. Connell
Published: May 2008

A new approach for demonstrating the global stability of ordinary differential equations
is given. It is shown that if the curvature of solutions is bounded on some set, then
any nonconstant orbits that remain in the set, must contain points that lie some minimum
distance apart from each other. This is used to establish a negative‐criterion for periodic
orbits. This is extended to give a method of proving an equilibrium to be globally stable. The
approach can also be used to rule out the sudden appearance of large‐amplitude periodic orbits.
Generalized Moisil‐Théodoresco Systems and Cauchy Integral Decompositions
Authors: Abreu Blaya Ricardo , Bory Reyes Juan , Delanghe Richard , Sommen Frank
Published: May 2008

Let be the space of s‐vectors (0 ≤ s ≤ m + 1) in the Clifford
algebra ℝ0,m+1 constructed over the quadratic vector space ℝ0,m+1, let r, p, q ∈ ℕ with 0 ≤ r ≤ m + 1,  0 ≤ p ≤ q, and r + 2q ≤ m + 1, and let . Then, an ‐valued smooth function W defined in an open subset Ω ⊂ ℝm+1 is said to satisfy the generalized
Moisil‐Théodoresco system of type (r, p, q) if ∂xW = 0 in Ω, where ∂x is the Dirac operator in ℝm+1. A structure theorem is proved
for such functions, based on the construction of conjugate harmonic
pairs. Furthermore, if Ω is bounded with boundary Γ, where Γ is
an Ahlfors‐David regular surface, and if W is a ‐valued Hölder
continuous function on Γ, then necessary and sufficient conditions are
given under which W admits on Γ a Cauchy integral decomposition
W = W+ + W−.
Performance of a Self-Paced Brain Computer Interface on Data Contaminated with Eye-Movement Artifacts and on Data Recorded in a Subsequent Session
Authors: Fatourechi Mehrdad , Ward Rabab K. , Birch Gary E.
Published: May 2008

The performance of a specific self-paced BCI (SBCI) is investigated using two different datasets to determine its suitability for using online: (1) data contaminated with large-amplitude eye movements, and (2) data recorded in a session subsequent to the original sessions used to design the system. No part of the data was rejected in the subsequent session. Therefore, this dataset can be regarded as a “pseudo-online” test set. The SBCI under investigation uses features extracted from three specific neurological phenomena. Each of these neurological phenomena belongs to a different frequency band. Since many prominent artifacts are either of mostly low-frequency (e.g., eye movements) or mostly high-frequency nature (e.g., muscle movements), it is expected that the system shows a fairly robust performance over artifact-contaminated data. Analysis of the data of four participants using epochs contaminated with large-amplitude eye-movement artifacts shows that the system's performance deteriorates only slightly. Furthermore, the system's performance during the session subsequent to the original sessions remained largely the same as in the original sessions for three out of the four participants. This moderate drop in performance can be considered tolerable, since allowing artifact-contaminated data to be used as inputs makes the system available for users at ALL times.
Theorems on Positive Data: On the Uniqueness of NMF
Authors: Laurberg Hans , Christensen Mads Græsbøll , Plumbley Mark D. , Hansen Lars Kai , Jensen Søren Holdt
Published: May 2008

We investigate the conditions for which nonnegative matrix factorization (NMF) is unique and introduce several theorems which can determine whether the decomposition is in fact unique or not. The theorems are illustrated by several examples showing the use of the theorems and their limitations. We have shown that corruption of a unique NMF matrix by additive noise leads to a noisy estimation of the noise-free unique solution. Finally, we use a stochastic view of NMF to analyze which characterization of the underlying model will result in an NMF with small estimation errors.
Robust Object Recognition under Partial Occlusions Using NMF
Authors: Soukup Daniel , Bajla Ivan
Published: May 2008

In recent years, nonnegative matrix factorization (NMF) methods of a reduced image data representation attracted the attention of computer vision community. These methods are considered as a convenient part-based representation of image data for recognition tasks with occluded objects. A novel modification in NMF recognition tasks is proposed which utilizes the matrix sparseness control introduced by Hoyer. We have analyzed the influence of sparseness on recognition rates (RRs) for various dimensions of subspaces generated for two image databases, ORL face database, and USPS handwritten digit database. We have studied the behavior of four types of distances between a projected unknown image object and feature vectors in NMF subspaces generated for training data. One of these metrics also is a novelty we proposed. In the recognition phase, partial occlusions in the test images have been modeled by putting two randomly large, randomly positioned black rectangles into each test image.
Probabilistic Latent Variable Models as Nonnegative Factorizations
Authors: Shashanka Madhusudana , Raj Bhiksha , Smaragdis Paris
Published: May 2008

This paper presents a family of probabilistic latent variable models that can be used for analysis of nonnegative data. We show that there are strong ties between nonnegative matrix factorization and this family, and provide some straightforward extensions which can help in dealing with shift invariances, higher-order decompositions and sparsity constraints. We argue through these extensions that the use of this approach allows for rapid development of complex statistical models for analyzing nonnegative data.
Targeting CUB Domain-Containing Protein 1 with a Monoclonal Antibody Inhibits Metastasis in a Prostate Cancer Model
Authors: Siva Amara C. , Wild Martha A. , Kirkland Richard E. , Nolan Mary Jean , Lin Bing , Maruyama Toshiaki , Yantiri-Wernimont Ferda , Frederickson Shana , Bowdish Katherine S. , Xin Hong
Published: May 2008

Through a whole-cell panning approach, we previously identified a panel of antibodies that bound to prostate cancer cell surface antigens. One such antigen, CUB domain-containing protein 1 (CDCP1), was recognized by monoclonal antibody 25A11 and is a single transmembrane molecule highly expressed in several metastatic cancers as well as on CD34+CD133+ myeloid leukemic blast cells. We show CDCP1 expression on prostate cancer cell lines by real-time quantitative PCR (RT-qPCR), flow cytometry, and immunohistochemistry and on prostate cancer patient samples by RT-qPCR and immunohistochemical staining. In cell-based assays, antibody 25A11 inhibited prostate cancer cell migration and invasion in vitro. Further characterization showed that CDCP1 is internalized on antibody binding. When 25A11 was coupled to the cytotoxin saporin either directly or via a secondary antibody, both resulted in prostate cancer cell killing in vitro. In vivo targeting studies with an anti-CDCP1 immunotoxin showed significant inhibition of primary tumor growth as well as metastasis in a mouse xenograft model. These data provide support for continued evaluation of anti-CDCP1 therapy for potential use in cancer in primary and metastatic disease. [Cancer Res 2008;68(10):3759–66]
Rap1GAP Promotes Invasion via Induction of Matrix Metalloproteinase 9 Secretion, Which Is Associated with Poor Survival in Low N-Stage Squamous Cell Carcinoma
Authors: Mitra Raj S. , Goto Mitsuo , Lee Julia S. , Maldonado Diana , Taylor Jeremy M.G. , Pan Quintin , Carey Thomas E. , Bradford Carol R. , Prince Mark E. , Cordell Kitrina G. , Kirkwood Keith L. , D'Silva Nisha J.
Published: May 2008

The objective of the current study was to investigate the effects of Rap1GAP on invasion and progression of head and neck squamous cell carcinoma (SCC) and the role of matrix metalloproteinase (MMP) 9 and MMP2 in this process. Rap1GAP functions by switching off Rap1, the Ras-like protein that has been associated with carcinogenesis. Previous findings suggest that Rap1GAP acts as a tumor suppressor protein in SCC by delaying the G1-S transition of the cell cycle. However, cells transfected with Rap1GAP exhibit a more invasive phenotype than corresponding vector-transfected control cells. MMP2 and MMP9 are enzymes that mediate SCC invasion via degradation of the extracellular matrix. Using SCC cells transfected with empty vector or Rap1GAP, cell invasion and MMP secretion were determined by Matrigel assays and gelatin zymography, respectively. Rap1GAP up-regulated transcription and secretion of MMP2 and MMP9, as assayed by quantitative reverse transcription-PCR and zymography. Furthermore, chemical and RNA interference blockade of MMP2/MMP9 inhibited invasion by Rap1GAP-transfected cells. Immunohistochemical staining of a human oropharyngeal SCC tissue microarray showed that Rap1GAP and MMP9 expression and staining intensity are correlated (P < 0.0001) and that, in early N-stage lesions of SCC, high MMP9 is prognostic of poor disease-specific survival (P < 0.05). Furthermore, Rap1GAP staining is correlated with MMP2 (P < 0.03). MMP2 in combination with N stage has a prognostic effect on time to indication of surgery at primary site. MMP2 intensity is also positively correlated with T stage (P < 0.015). In conclusion, Rap1GAP inhibits tumor growth but induces MMP2- and MMP9-mediated SCC invasion and tumor progression, suggesting a role for this protein as a biomarker for early N-stage, aggressive SCCs. [Cancer Res 2008;68(10):3959–69]
Activation of Estrogen Receptor-α by the Anion Nitrite
Authors: Veselik David J. , Divekar Shailaja , Dakshanamurthy Sivanesan , Storchan Geoffrey B. , Turner Jasmine M.A. , Graham Kelly L. , Huang Li , Stoica Adriana , Martin Mary Beth
Published: May 2008

In this study, the ability of nitrite and nitrate to mimic the effects of estradiol on growth and gene expression was measured in the human breast cancer cell line MCF-7. Similar to estradiol, treatment of MCF-7 cells with either 1 μmol/L nitrite or 1 μmol/L nitrate resulted in ∼4-fold increase in cell growth and 2.3-fold to 3-fold increase in progesterone receptor (PgR), pS2, and cathepsin D mRNAs that were blocked by the antiestrogen ICI 182,780. The anions also recruited estrogen receptor-α (ERα) to the pS2 promoter and activated exogenously expressed ERα when tested in transient cotransfection assays. To determine whether nitrite or nitrate was the active anion, diphenyleneiodonium was used to inhibit oxidation/reduction reactions in the cell. The ability of diphenyleneiodonium to block the effects of nitrate, but not nitrite, on the induction of PgR mRNA and the activation of exogenously expressed ERα suggests that nitrite is the active anion. Concentrations of nitrite, as low as 100 nmol/L, induced a significant increase in PgR mRNA, suggesting that physiologically and environmentally relevant doses of the anion activate ERα. Nitrite activated the chimeric receptor Gal-ER containing the DNA-binding domain of GAL-4 and the ligand-binding domain of ERα and blocked the binding of estradiol to the receptor, suggesting that the anion activates ERα through the ligand-binding domain. Mutational analysis identified the amino acids Cys381, His516, Lys520, Lys529, Asn532, and His547 as important for nitrite activation of the receptor. [Cancer Res 2008;68(10):3950–8]