bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzymatic kinetic parameters for polyfluorinated alkyl phosphate hydrolysis by alkaline phosphatase
Authors: Jackson Derek A. , Mabury Scott A. 
Published: June 2012

Abstract
The hydrolysis kinetics of three polyfluorinated alkyl phosphate monoesters (monoPAPs), differing in fluorinated chain length, were measured using bovine intestinal alkaline phosphatase to catalyze the reaction. Kinetic values were also measured for analogous hydrogenated phosphate monoesters to elucidate the effects of the fluorinated chain on the rate of enzymatic hydrolysis. Michaelis constants (Km) were obtained by a competition kinetics technique in the presence of p-nitrophenyl phosphate (PNPP) using UV-vis spectroscopy. Compared with Km (PNPP), Michaelis constants for monoPAPs ranged from 0.9 to 2.1 compared with hydrogenated phosphates, which ranged from 4.0 to 13.0. Apparent bimolecular rate constants (kcat/Km) were determined by monitoring rates of product alcohol formation at low substrate concentrations using gas chromatography–mass spectrometry. The experimental values for kcat/Km averaged as 1.1 × 107 M−1s−1 for monoPAPs compared with 3.8 × 105 M−1s−1 for hexyl phosphate. This suggests that the electron-withdrawing nature of the fluorinated chain enhanced the alcohol leaving group ability. The results were used in a simple model to suggest that monoPAPs in a typical mammalian digestive tract would hydrolyze in approximately 100 s, supporting a previous study that showed its absence after a dosing study in rats. Environ. Toxicol. Chem. 2012; 31: 1966–1971. © 2012 SETAC
Dynamic relay‐location‐oriented group management in MMR WiMAX networks
Authors: Sendín‐Raña Pablo , González‐Castaño Francisco J. , Gil‐Castiñeira Felipe , Rodríguez‐Hernández Pedro S. 
Published: June 2012

ABSTRACTMultihop wireless systems outperform single‐hop ones in terms of coverage and capacity. The IEEE 802.16 standard, also known as Worldwide Interoperability for Microwave Access (WiMAX), is one of the latest broadband wireless access technologies over long distances. Mobile multihop relay (MMR) WiMAX networks introduce relay stations (RS) to improve range and performance at low cost.Providing multimedia capabilities to groups defined by node proximity is an interesting feature in tactical communications, which MMR WiMAX networks may support. This paper presents a dynamic group management scheme at the Medium Access Control (MAC) layer based on RS position, with dynamic RS selection, suitable for military environments where communications between close nodes are prioritary. The proposal is evaluated analytically and by simulations. Copyright © 2012 John Wiley & Sons, Ltd.
Outage probability scaling laws for SISO and MIMO ad‐hoc networks
Authors: Keshavarz Hengameh , Ahmadi‐Shokouh Javad 
Published: June 2012

ABSTRACTIn this paper, the outage probability scaling laws for ad‐hoc networks with an arbitrary topology is studied. In single‐input single‐output ad‐hoc networks, the outage probability is tightly bounded as the number of users goes to infinity in case that channel gains are independent and identically distributed (i.i.d.). If channel gains are not i.i.d. or calculating the distribution function is complicated because path loss, it is still possible to bound the outage probability if the distances between transmitter–receiver pairs are bounded. However, there is a gap between the upper and lower bounds. Unlike previous results, our analysis is completely general and is not limited to specific node and fading distributions. In multiple‐input multiple‐output ad‐hoc networks, the calculations are much more complicated, and it is hard to tightly bound the outage probability. For a special case of i.i.d. Gaussian channel matrices, the outage probability is asymptotically bounded in terms of Chi‐square distribution functions. Finally, as an application, the outage probability analysis is utilized to study delay scaling laws in random ad‐hoc networks. Simulation results show accuracy of this estimation for different scenarios. Copyright © 2012 John Wiley & Sons, Ltd.
Network‐wide energy efficiency in wireless networks with multiple access points
Authors: Ozel Omur , Uysal‐Biyikoglu Elif 
Published: June 2012

ABSTRACTThis paper presents a distributed mechanism for improving the overall energy efficiency of a wireless network where users can control their uplink transmit power targeted to the multiple access points in the network. This mechanism lets the network achieve a trade‐off between energy efficiency and spectral efficiency through the use of suitably designed utility functions. A user's utility is a function of throughput and average transmission power. Throughput is assumed to be a sigmoidal function of signal‐to‐interference‐plus‐noise ratio. Each user, being selfish and rational, acts to maximise its utility in response to signal‐to‐interference‐plus‐noise ratio by adjusting its power. The resulting mechanism is a distributed power control scheme that can incline towards energy‐efficient or spectrally efficient operating points depending on the choice of utility function. Existence and uniqueness of Nash equilibrium points in this game are shown via convergence of the distributed power iterations. It is shown that, in the best‐response strategy, each user selects a single access point. An extension of this result for a multicarrier system is considered, and the corresponding power levels used for various priorities between energy efficiency and spectral efficiency are characterised. Finally, several numerical studies are presented to illustrate the analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Bin size determination for the measurement of mean flow velocity in molecular dynamics simulations
Authors: Karimian S. M. H. , Izadi S. 
Published: June 2012

SUMMARYExtracting macroscopic properties from molecular simulation of fluids is required in most of the molecular dynamics problems. However, methods used for this purpose, their accuracy, and their dependence on the sampling and averaging schemes are still ambiguous. Macroscopic properties at any point of a molecular domain can be extracted via sampling and averaging of molecular behavior within a control region around that point, called a bin. The size of this bin has a significant impact on the accuracy of the macroscopic properties' measurement. In this research, we will focus on the measurement of mean flow velocity using ‘binning method’. On the basis of the results of this study, the most appropriate range of the bin size in which mean velocity can be measured accurately is determined. Although this range is determined based on the measurement of mean flow velocity, we believe that it can be used to estimate the proper range for the measurement of other flow quantities as well. Copyright © 2012 John Wiley & Sons, Ltd.
An implicit meshless method for application in computational fluid dynamics
Authors: Kennett D. J. , Timme S. , Angulo J. , Badcock K. J. 
Published: June 2012

SUMMARYAn implicit meshless scheme is developed for solving the Euler equations, as well as the laminar and Reynolds‐averaged Navier–Stokes equations. Spatial derivatives are approximated using a least squares method on clouds of points. The system of equations is linearised, and solved implicitly using approximate, analytical Jacobian matrices and a preconditioned Krylov subspace iterative method. The details of the spatial discretisation, linear solver and construction of the Jacobian matrix are discussed; and results that demonstrate the performance of the scheme are presented for steady and unsteady two dimensional fluid flows. Copyright © 2012 John Wiley & Sons, Ltd.
Detection of EML4‐ALK fusion genes in non‐small cell lung cancer patients with clinical features associated with EGFR mutations
Authors: Shaozhang Zhou , Xiaomei Lin , Aiping Zeng , Jianbo He , Xiangqun Song , Qitao Yu 
Published: June 2012

AbstractEML4‐ALK fusion genes have been recognized as novel “driver mutations” in a small subset of non‐small cell lung cancers (NSCLC). The frequency of EML4‐ALK fusions in NSCLC patients who have clinical characteristics related to EGFR mutation remains unknown. We screened 102 Chinese patients with NSCLC based on one or more of the following characteristics: female, no or light smoking history, and adenocarcinoma histology. EML4‐ALK fusion genes were identified by RT‐PCR, whereas EGFR (Exons 18–21) and KRAS (Exons 1 and 2) mutations were detected by DNA sequencing. Eight specimens (8%) were positive for EML4‐ALK fusions, with seven being Variant 1 and one Variant 2. There were 44 (43%) and 17 (16%) patients harboring EGFR and KRAS mutations, respectively. Thirty‐one (31%) cases were wild type for EML4‐ALK, EGFR, and KRAS mutations. Of the eight patients with EML4‐ALK, none had an EGFR mutation, whereas a KRAS mutation was detected in one patient. Histologically, five of the EML4‐ALK positive tumors were adenocarcinoma and two were mixed adenosquamous carcinoma; only one was a squamous carcinoma. Our data support the conclusion that the EML4‐ALK fusion gene defines a new molecular subset of NSCLC with distinct pathologic features. © 2012 Wiley Peiodicals, Inc.
Torino subsoil characterization by combining site investigations and numerical modelling / Charakterisierung des Turiner Untergrunds mithilfe von Feldstudien und numerischer Modellierungen
Authors: Barla Marco , Barla Giovanni 
Published: June 2012

AbstractThis paper presents the results of the studies undertaken to assess the geotechnical parameters of the Torino subsoil (Italy). The ground conditions are characterized by a sand and gravel deposit, ranging from medium to highly dense, down to a depth of 8 to 10 m, and cemented soil (in cases a conglomerate), due to calcareous deposition processes, below this depth. The random distribution of cementation in the ground is a key factor in design and construction of underground works. To assess the ground properties as a function of the cementation degree, continuum and discontinuum numerical modelling were used. These were closely linked to the results of the characterization studies carried out so far in the laboratory and in the field (monitored drilling, SPT, large diameter pits, plate loading tests).In diesem Artikel werden die Ergebnisse mehrerer Untersuchungen der geotechnischen Parameter des Turiner Untergrunds (Italien) vorgestellt. Der Turiner Boden zeichnet sich durch eine mitteldicht‐ bis dichtgelagerte Sand‐ und Kiesablagerung aus, die in einer Tiefe von 8 bis 10 m ansteht; darunter liegt zementierter Boden (in einigen Fällen als Konglomerat), der auf Kalkablagerungsprozesse zurückzuführen ist. Die zufällige Verteilung der Bodenzementierung ist einer der wesentlichen Faktoren, die die Bemessung und die Durchführung von unterirdischen Bauvorhaben beeinflusst. Um die Charakteristika des Bodens in Abhängigkeit vom Zementierungsgrad zu untersuchen, wurden kontinuums‐ und diskontinuumsmechanische numerische Modellierungen durchgeführt. Diese Modelle stehen in direktem Zusammenhang mit den Ergebnissen von Versuchsreihen, die bis dahin im Labor und in situ ausgearbeitet wurden (Bohraufzeichnungen, SPT, großflächige Schürfe, Plattendruckversuche).
Torino Metro Line 1 south extension – modelling and settlement monitoring / Süderweiterung der Turiner Metro Linie 1 – Modellierung und Monitoring der Setzungen
Authors: Barla Marco , Barla Giovanni , Gianoglio Gianluca 
Published: June 2012

AbstractThe excavation of a 3.6 km long tunnel for the Torino Metro Line 1 South Extension was recently completed by a 7.8 m diameter EPB TBM. A critical section of the tunnel was near Corso Spezia, in the Lingotto area, where the main difficulties were the presence of the water table and the poor ground conditions encountered. Another concern was the effect of the excavation on two five‐storey masonry buildings adjacent to the tunnel alignment, which were constructed in 1930 and suffered severe damage during World War II. Continuous monitoring was undertaken during excavation as time dependent settlements occurred. 2D Finite Element modelling was used to simulate the excavation and its effects on the buildings. This paper describes the most significant performance monitoring data, which is compared with the results of modelling.Kürzlich wurde der Vortrieb eines 3,6 km langen Tunnels für die Süderweiterung der Turiner Metro Linie 1 mittels einer EPB‐Tunnelbohrmaschine mit einem Durchmesser von 7,8 m abgeschlossen. Ein kritischer Abschnitt des Tunnels lag nahe dem Corso Spezia, im Lingotto Bereich. Die Hauptschwierigkeiten dort waren die Lage des Grundwasserspiegels und die schlechten angetroffenen Bodenverhältnissen. Eine weitere Sorge galt den Auswirkungen des Tunnelvortriebs auf zwei nahe der Tunneltrasse gelegene, fünfstöckige Mauerwerksgebäude, die in den 1930er Jahren erbaut wurden und bereits im zweiten Weltkrieg erhebliche Schäden erlitten hatten. Während des Vortriebs wurde daher eine kontinuierliche Überwachung der auftretenden zeitabhängigen Setzungen durchgeführt. Eine 2D Finite‐Elemente Modellierung diente der Simulation des Vortriebsvorgangs und dessen Auswirkungen auf die Gebäude. Im vorliegenden Beitrag werden die wichtigsten Daten des Monitorings dargestellt und mit den Modellierungsergebnissen verglichen.
Multiple P2Y subtypes in spinal microglia are involved in neuropathic pain after peripheral nerve injury
Authors: Kobayashi Kimiko , Yamanaka Hiroki , Yanamoto Fujio , Okubo Masamichi , Noguchi Koichi 
Published: June 2012

AbstractA prominent signaling pathway in the development of neuropathic pain involves ATP acting on microglial purinergic receptors. Among the P2Y metabotropic receptors, we reported before that the P2Y12 receptor is upregulated in microglia following nerve injury and involved in the phosphorylation of p38 MAPK, and in the development of pain behavior. In this study, we examined the expression of P2Y6, P2Y13, and P2Y14 receptors in the spinal cord and whether these receptors are involved in the pathogenesis of neuropathic pain following peripheral nerve injury. We found that spared nerve injury induced a dramatic increase of not only P2Y12, but also P2Y6, 13, and 14 receptor mRNA expression in spinal microglia. The increase continued for at least 2 weeks after injury. To determine whether p38 MAPK can induce the expression of P2Y receptors, we administered intrathecally the p38 MAPK inhibitor SB203580 and found that it significantly suppressed P2Y6, P2Y13, and P2Y14 but not P2Y12 mRNAs. Intrathecal injection of the specific P2Y6 antagonist MRS2578, specific P2Y13 antagonist MRS2211 or P2Y14 antisense LNA, attenuated mechanical pain hypersensitivity. Themixture of three antagonists for P2Y6, 12, and 13 showed a longer suppressive effect on pain behavior than the individual treatments. Our data demonstrate that ATP and other nucleotides may stimulate activated microglia with the upregulation of P2Y6, P2Y12, P2Y13, and P2Y14 receptors following nerve injury and these receptors are involved in the development of neuropathic pain. © 2012 Wiley Periodicals, Inc.
CaMKII, MAPK, and CREB are coactivated in identified neurons in a neocortical circuit required for performing visual shape discriminations
Authors: Zhang Guo‐Rong , Zhao Hua , Choi Eui M. , Svestka Michael , Wang Xiaodan , Cook Robert G. , Geller Alfred I. 
Published: June 2012

AbstractCurrent theories postulate that the essential information for specific cognitive tasks is widely dispersed in multiple forebrain areas. Nonetheless, synaptic plasticity and neural network theories hypothesize that activation of specific signaling pathways, in specific neurons, modifies synaptic strengths, thereby encoding essential information for performance in localized circuits. Consistent with these latter theories, we have shown that gene transfer of a constitutively active protein kinase C into several hundred glutamatergic and GABAergic neurons in rat postrhinal cortex enhances choice accuracy in visual shape discriminations, and the genetically‐modified circuit encodes some of the essential information for performance. However, little is known about the role of specific signaling pathways required for learning, in specific neurons within a critical circuit. Here we show that three learning‐associated signaling pathways are coactivated in the transduced neurons during both learning and performance. After gene transfer, but before learning a new discrimination, the calcium/calmodulin‐dependent protein kinase (CaMKII), MAP kinase, and CREB pathways were inactive. During learning, these three pathways were coactivated in the transduced neurons. During later performance of the discrimination, CaMKII activity declined, but MAP kinase and CREB activity persisted. Because the transduced neurons are part of a circuit that encodes essential information for performance, activation of these learning‐associated signaling pathways, in these identified neurons, is likely important for both learning and performance. © 2012 Wiley Periodicals, Inc.
Motivation of human resources for health: a case study at rural district level in Tanzania
Authors: Zinnen Véronique , Paul Elisabeth , Mwisongo Aziza , Nyato Daniel , Robert Annie 
Published: June 2012

SUMMARYAn increasing number of studies explore the association between financial and non‐financial incentives and the retention of health workers in developing countries. This study aims to contribute to empirical evidence on human resource for health motivation factors to assist policy makers in promoting effective and realistic interventions. A cross‐sectional survey was conducted in four rural Tanzanian districts to explore staff stability and health workers' motivation. Data were collected using qualitative and quantitative techniques, covering all levels and types of health facilities. Stability of staff was found to be quite high. Public institutions remained very attractive with better job security, salary and retirement benefits. Satisfaction over working conditions was very low owing to inadequate working equipment, work overload, lack of services, difficult environment, favouritism and ‘empty promotions’. Positive incentives mentioned were support for career development and supportive supervision. Attracting new staff in rural areas appeared to be more difficult than retaining staff in place. The study concluded that strategies to better motivate health personnel should focus on adequate remuneration, positive working and living environment and supportive management. However, by multiplying health facilities, the latest Tanzanian human resource for health plan could jeopardize current positive results. Copyright © 2012 John Wiley & Sons, Ltd.
Soil moisture and rainfall intensity thresholds for runoff generation in southwestern Wisconsin agricultural watersheds
Authors: Radatz Timothy F. , Thompson Anita M. , Madison Frederick W. 
Published: June 2012

AbstractThe goal of this study was to improve understanding of the factors that influence runoff generation during non‐frozen ground periods in small agricultural watersheds in southwestern Wisconsin where the landscapes are controlled by dolostone bedrock in order to provide agricultural producers with a manure management tool. Six small watersheds (ranging from 6 to 17 ha) within two southwestern Wisconsin farm sites (Discovery Farms Program (DFP) and Pioneer Farm (PF)) were instrumented, and surface runoff was continuously monitored from 2004 to 2007. The soils in all watersheds were formed in deep (~1 m) loessial sites. A direct‐plant management strategy and corn‐soybean crop rotation were utilized within watersheds at DFP. A conventional tillage system (chisel plow in the fall followed by soil finisher in the spring) and a corn‐oat‐alfalfa crop rotation were utilized within watersheds at PF. At PF, the amount of precipitation leaving the landscape as surface runoff (1.8%) was two times greater compared to DFP (0.9%), indicating that the direct‐plant management system was better at retaining precipitation than the chisel plow/soil finisher system. Using breakpoint regression analysis, a non‐linear response in runoff generation with antecedent soil moisture (ASM) was observed with a threshold ASM of 0.39 cm3cm−3(approximately 80% of total porosity) for all six watersheds. Below this threshold, runoff coefficients were near zero. Above this threshold, runoff coefficients increased with ASM. A non‐linear response in runoff generation with maximum 30 min rainfall intensity (I30) was also observed, and threshold I30 values increased as ASM decreased and as crop cover increased. Copyright © 2012 John Wiley & Sons, Ltd.
NOS‐2 signaling and cancer therapy
Authors: Bian Ka , Ghassemi Farshid , Sotolongo Alex , Siu Alan , Shauger Lauren , Kots Alex , Murad Ferid 
Published: June 2012

AbstractThe role of NO and cGMP signaling in tumor biology has been extensively studied during the past three decades. However, whether the pathway is beneficial or detrimental in cancer is still open to question. We suggest several reasons for this ambiguity: first, although NO participates in normal signaling (e.g., vasodilation and neurotransmission), NO is also a cytotoxic or apoptotic molecule when produced at high concentrations by inducible nitric‐oxide synthase (iNOS or NOS‐2). In addition, the cGMP‐dependent (NO/sGC/cGMP pathway) and cGMP‐independent (NO oxidative pathway) components may vary among different tissues and cell types. Furthermore, solid tumors contain two compartments: the parenchyma (neoplastic cells) and the stroma (nonmalignant supporting tissues including connective tissue, blood vessels, and inflammatory cells) with different NO biology. Thus, the NO/sGC/cGMP signaling molecules in tumors as well as the surrounding tissue must be further characterized before targeting this signaling pathway for tumor therapy. In this review, we focus on the NOS‐2 expression in tumor and surrounding cells and summarized research outcome in terms of cancer therapy. We propose that a normal function of the sGC‐cGMP signaling axis may be important for the prevention and/or treatment of malignant tumors. Inhibiting NOS‐2 overexpression and the tumor inflammatory microenvironment, combined with normalization of the sGC/cGMP signaling may be a favorable alternative to chemotherapy and radiotherapy for malignant tumors. © 2012 IUBMB IUBMB Life, 64(8): 676–683, 2012
TRAF3 negatively regulates calcineurin‐NFAT pathway by targeting calcineurin B subunit for degradation
Authors: Wang Xinyu , Huang Yi , Li Li , Wei Qun 
Published: June 2012

AbstractCalcineurin (CN) is the only serine/threonine specific protein phosphatase regulated by Ca2+/calmodulin (CaM), which is composed of catalytic A subunit (CNA) and regulatory B subunit (CNB). Tumor necrosis factor (TNF) receptor associated factor 3 (TRAF3) is an essential component in the Toll like receptors and TNF receptors (TNFRs) pathways. The TRAF domain of TRAF3 interacts with a large range of proteins, which share consensus sequences known as TRAF interacting motifs (TIMs). By sequence alignment, we identified two potential TIMs in CNB. However, the relation between TRAF3 and CN has not been reported before. To explore this, we highly expressed the former insoluble TRAF domain of TRAF3 in soluble form by using CaM fusion system for the first time. We demonstrated that the TRAF domain of TRAF3 interacted with CNB. On further investigation, over‐expression of TRAF3 inhibited endogenous CN's activity, which decreased NFAT reporter activity and IL‐2 production. Knock‐down of TRAF3 partially enhanced CN's activity. The possible mechanism was that TRAF3 functioned as ubiquitin E3 ligase for CN and promoted its degradation. © 2012 IUBMB IUBMB Life IUBMB Life, 64(9): 748–756, 2012