bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverse analysis–based interpretation of sand behavior from triaxial compression tests subjected to full end restraint
Authors: Hashash Youssef M.A. , Fu Qingwei , Ghaboussi Jamshid , Lade Poul V. , Saucier Christopher
Published: July 2009

Current laboratory testing often imposes or assumes uniform stress and strain distribution in a specimen for convenient data reduction to interpret soil behavior. This paper presents an inverse analysis framework, Self-learning Simulations (SelfSim), to interpret the drained behavior of sand from triaxial compression tests with fully frictional loading platens. The frictional platens result in significant bulging of and nonuniform stresses and strains within sand specimens. SelfSim treats the specimen as a boundary value problem (BVP) and extracts these nonuniform stresses and strains from within each specimen using external load and displacement measurements. The extracted behavior shows significant principal stress rotation, variation of intermediate principal stress, and nonuniform volume change throughout the specimen. Mobilized friction angles are interpreted on the two-dimensional slip surface associated with the Mohr–Coulomb failure criterion, on the octahedral plane associated with the Drucker–Prager failure criterion, and on the spatially mobilized plane (SMP) associated with the Matsuoka–Nakai failure criterion. The extracted stress–strain behavior is used to examine the sand’s stress-dilatancy characteristics. Proposed integration of SelfSim inverse analysis with laboratory testing opens the way for new and efficient approaches to soil behavior characterization under general loading conditions, needed for the solution of general geotechnical boundary value problems, from readily available laboratory tests.
Time-domain reflectometry — parametric study for the evaluation of physical properties in soils
Authors: Schneider Jeffrey M. , Fratta Dante
Published: July 2009

Time-domain reflectometry (TDR) has become a commonly used method in geotechnical engineering to measure the volumetric water content and electrical conductivity in soils. The ability of TDR to accurately determine soil properties depends on the proper understanding of the parameters that affect the propagation of an electromagnetic pulse along the TDR waveguide. The purpose of this paper is to document a parametric study and analyses aimed at gaining a better understanding of TDR measurements and to evaluate the limits in the measurement technique. A parametric study on TDR signals was performed by determining the effects of heterogeneities in the dielectric permittivity, conductivity, and magnetic permeability in sand and gravel specimens. Impedance differences in the probe head were found to contribute to inaccurate travel-time measurements that affect material dielectric permittivity calculations. The calculated relative dielectric permittivity may also be dependent on local changes in porosity near the probes. Tests performed in layered materials indicate that TDR can be used to find abrupt changes in material permittivity, such as the depth to saturation. However, problems in the determination of capillary rise may contribute to uncertainties in the proper determination of permittivity and thicknesses of layers. The presence of ferromagnetic materials was found to change the measured electromagnetic wave velocity. However, the properties of materials outside the radius defined by the probes and beneath the probes minimally affected the TDR results in the two-rod probe used.
Use of instantaneous profile and statistical methods to determine permeability functions of unsaturated soils
Authors: Krisdani Henry , Rahardjo Harianto , Leong Eng-Choon
Published: July 2009

This paper presents the determination of permeability functions by direct and indirect methods. The direct method used in this study was the instantaneous profile method, while the indirect method used was the statistical method. The instantaneous profile method was adopted to calculate permeability functions of residual soils used in laboratory slope models. Pore-water pressure measured using tensiometers along the slope models and independently measured soil-water characteristic curves (SWCCs) were used for the instantaneous profile calculation. To obtain a continuous permeability function, the instantaneous profile results were then fitted using the statistical method.
The application of the ONIOM hybrid method to the cycloaddition reactions of bromo-substituted 2(H)-pyran-2-ones
Authors: Larkin Susan M. , Vreven Thom , Bearpark Michael J. , Morokuma Keiji
Published: July 2009

We investigate the performance of Our own N-layered Integrated molecular Orbital and molecular Mechanics (ONIOM) hybrid computational method applied to Diels–Alder reactions of bromo-2(H)-pyran-2-ones, combining the B3LYP/6–31G(d) method with a variety of low-level methods. We show that ONIOM is able to reproduce full B3LYP calculations, including the prediction of the stereoselectivity, which requires accurate potentials. We focus on the various ways in which the performance and potential errors of ONIOM can be analyzed, and show that the best method combination depends on the property one is interested in.
Energetics of naphthynes — Performance of reduced multi-reference coupled-cluster methods for diradicals
Authors: Li Xiangzhu , Paldus Josef
Published: July 2009

The energetics of all the possible isomers of the didehydronaphthalene (naphthalyne or naphthyne) diradical has been examined using the reduced multi-reference (RMR) coupled-cluster (CC) method with singles and doubles (RMR CCSD) that employs a modest size MR CISD wave function as an external source of the most important (primary) triples and quadruples to account for nondynamic correlation effects in the presence of quasi-degeneracy, as well as by its perturbatively corrected version for the secondary triples, the RMR CCSD(T) method. The resulting energies are compared with those obtained by the standard single-reference (SR) CCSD and CCSD(T) approaches. In all cases, we used both the cc-pVDZ basis set, as well as its restricted version cc-pVDZ* with deleted p-functions on hydrogens. Once the optimal geometry for each isomer was found, we computed the energy of the lowest-lying singlet and triplet states using the above mentioned CC methods, as well as the implied singlet–triplet splittings. These results enabled us to classify the isomers into three groups according to their stability and to determine, whenever possible, the spin multiplicity of the ground state. Finally, we point out the relationship between the extent of the diradical character of naphthyne isomers, the degree of their MR nature, the distance separating the radical centers, and, finally, the size of the largest doubly-excited cluster amplitude in their CC wave functions.
The response of extended systems to electrostatic fields
Authors: Springborg Michael , Kirtman Bernard
Published: July 2009

The response to electrostatic fields by finite systems, which contain a large central region of chemically identical building blocks, is shown not to depend on the boundaries of the system. Consequently, we can determine this response from that of the corresponding infinite periodic system and a vector potential theoretical–computational approach is presented for doing so. Both the electronic and structural response can be obtained with our approach. In many cases, neglecting the structural response is a poor approximation. To illustrate the performance of our treatment, extensive calculations have been carried out for simple model systems. Selected results are reported.
Effect of midrotation fertilization on growth and specific gravity of loblolly pine
Authors: Antony Finto , Jordan Lewis , Daniels Richard F. , Schimleck Laurence R. , Clark Alexander , Hall Daniel B.
Published: July 2009

Wood properties and growth were measured on breast-height cores and on disks collected at different heights from a thinned and fertilized midrotation loblolly pine ( Pinus taeda L.) plantation in the lower Coastal Plain of North Carolina. The study was laid out in a randomized complete-block design receiving four levels of nitrogen (N) fertilizer: unfertilized control and 112, 224, and 336 kg/ha plus 28 kg/ha of phosphorus with each treatment. The effect of fertilization was analyzed for the whole-disk and for a 4 year average following fertilization on data collected from breast-height cores and from disks. The fertilization treatments did not significantly affect whole-disk wood properties but significantly increased radial growth. Fertilization rate of 336 kg/ha N significantly reduced 4 year average ring specific gravity and latewood specific gravity. Wood properties of trees that received 112 and 224 kg/ha N were not affected following treatment. There was no height related trend in wood property changes due to fertilization. Fertilization significantly increased ring basal area and earlywood basal area. In summary, there was a decline in wood properties and an increase in basal area growth immediately after fertilization; both depended on the rate of fertilizer applied irrespective of height.
Impact of carbon value on the profitability of slash pine plantations in the southern United States: an integrated life cycle and Faustmann analysis
Authors: Dwivedi Puneet , Alavalapati Janaki R.R. , Susaeta Andres , Stainback Andrew
Published: July 2009

The emergence of voluntary carbon markets provides an additional income opportunity to nonindustrial private forest (NIPF) landowners because of the carbon sequestered in forest biomass. This study integrates life cycle analysis and the modified Faustmann model to assess the impact of carbon payments on the optimum rotation age and profitability of 1 ha of privately owned but intensely managed slash pine ( Pinus elliottii Engelm.) plantation in the southern United States. Guidelines of the Chicago Climate Exchange were followed for carbon payments. When carbon payments were included, land expectation values (LEVs) were found to be about $1384·ha–1 and $1063·ha–1 for the with and without thinning scenarios, respectively. When payment for carbon sequestered in the live forest biomass was included, LEVs increased to about $2807·ha–1 and $2765·ha–1 for the aforementioned scenarios, respectively. No significant change in the optimum rotation age was observed in the presence of carbon payments. Results suggest that voluntary carbon markets could play a key role in improving the financial returns to NIPF landowners.
Assessing effects of positioning errors and sample plot size on biophysical stand properties derived from airborne laser scanner data
Authors: Gobakken Terje , Næsset Erik
Published: July 2009

Canopy height distributions were created from small-footprint airborne laser scanner data with an average sampling density of 1.1 points·m–2 collected over 132 sample plots and 61 stands. Field measurements of each plot were carried out within two concentric circles (200 m2 and 300 or 400 m2). The plot positions were altered randomly with Monte Carlo simulations. For various metrics derived from the canopy height distributions, the mean and the standard deviation (SD) of the differences between incorrect plot positions and ground-truth positions were compared. In general, SD was smaller for large field plots than for small plots, and the variation in SD among the Monte Carlo repetitions was smaller for large sample plots. The combined effects of field plot size and sample plot position error on the accuracy of mean tree height (hL), stand basal area (G), and stand volume (V) predicted at stand level using a two-stage procedure combining field training data and laser data were assessed. Standard deviation of the differences between predicted and observed hL was quite stable and of similar size for position errors up to 5 m. However, for G and V the influence of plot position error was more pronounced.
Oak contribution to litter nutrient dynamics in an Appalachian forest receiving elevated nitrogen and dolomite
Authors: Piatek K.B. , Munasinghe P. , Peterjohn W.T. , Adams M.B. , Cumming J.R.
Published: July 2009

Ecosystem nitrogen (N), phosphorus (P), and calcium (Ca) fluxes are affected by inputs of atmospheric N. Oak litter may additionally affect these fluxes because of its high-lignin content. We analyzed nutrient dynamics in ambient mixed-species litter in an aggrading hardwood stand at the Fernow Experimental Forest in West Virginia. We separated oak from the mix for analysis (oak) and compared it with total litter (all species) to understand how oak affects nutrient fluxes in the litter layer. The study was conducted under ambient atmospheric deposition, under elevated atmospheric deposition, and under elevated deposition plus mitigation with dolomite. N flux between litterfall and 12 months later indicated a net loss in all-species litter of up to 7.3 kg N·ha–1 and a retention of up to 0.6 kg N·ha–1 in oak. P flux included losses in all species in ambient and in dolomite treatments of up to 0.19 kg P·ha–1 and gains of up to 0.12 kg P·ha–1 in oak in all treatments. Oak mineralized Ca at an average across treatments of 4.6 kg Ca·ha–1 compared with 16 kg Ca·ha–1 in all species, with half of that when trees were dormant. Percent immobilization and release over initial litter were greater in oak than in all species, but nutrient fluxes were lower in oak than in all species because of low oak litter mass. Elevated deposition lowered N and increased P immobilization. Dolomite appeared to affect early N dynamics only. With an increase in litterfall mass when forests mature, these effects are also likely to increase.
Potential effects of climate change on ecosystem distribution in Alberta
Authors: Schneider Richard R. , Hamann Andreas , Farr Dan , Wang Xianli , Boutin Stan
Published: July 2009

We propose a new and relatively simple modification to extend the utility of bioclimatic envelope models for land-use planning and adaptation under climate change. In our approach, the trajectory of vegetation change is set by a bioclimatic envelope model, but the rate of transition is determined by a disturbance model. We used this new approach to explore potential changes in the distribution of ecosystems in Alberta, Canada, under alternative climate and disturbance scenarios. The disturbance model slowed the rate of ecosystem transition, relative to the raw projections of the bioclimatic envelope model. But even with these transition lags in place, a northward shift of grasslands into much of the existing parkland occurred over the 50 years of our simulation. There was also a conversion of 12%–21% of Alberta’s boreal region to parkland. In addition to aspatial projections, our simulations provide testable predictions about where ecosystem changes as a result of climate change are most likely to be initially observed. We also conducted an investigation of model uncertainty that provides an indication of the robustness of our findings and identifies fruitful avenues for future research.
Chapter 11 Physics of Soft Pions and the Lightest Scalars at BES-III
Authors: Bian Jian-Ming , Bytev Vladimir , Chen Ying , Jin Hong-Ying , Jin Shan , Qin Hu , Shen Xiao-Yan , Wu Ning , Xu Guo-Fa , Zhang Zhen-Xia , Zhao Qiang , Zhemchugov Alexey , Zheng Han-Qing , Zhu Shi-Lin , Zou Bing-Song
Published: July 2009

The following sections are included:

Partially Conserved Vector Current (PCAC) and Soft Pions

Beyond the Breit–Wigner Description of a Broad Resonance

Final State Interaction Theorem and Omnés Solution

On the Nature of the Lightest Scalar Resonances
ELECTRON PARAMAGNETIC RESONANCE STUDIES OF (VO4)+2 IONS DOPED IN REDUCED Pb10-xCax(VO4)1(PO4)5(OH)2 APATITES [x = 0.0, 2.0, 4.0, 6.0, 8.0, AND 10.0]
Authors: IKRAM M. , AMBARDAR R. , ROSSI A. M. , EON J. G.
Published: July 2009

Polycrystalline solid solution of phosphate and vanadate lead calcium apatites Pb 10 -x Ca x( VO 4)1( PO 4)5( OH )2 apatites [x = 0.0, 2.0, 4.0, 6.0, 8.0, and 10.0] was reduced with hydrogen gas at the temperature of 300 and 400°C for 1 h. All these compounds were investigated by XRD and ESR spectroscopy. Only one reduced oxidation state V +4 was detected. Two types of species like isolated vanadium (+4) and clusters of V 4+ had been observed. The stability of the apatites increases and the particle size of the crystal decreases with calcium doping concentrations. As the concentrations of Ca increase the intensity of ESR lines deviates due to the spin–lattice relaxation interactions. The deviation in the intensity of ESR spectra can be attributed as the coexistence of paramagnetic and antiferromagnetic phases in the apatites.
ON THE THEORETICAL JUSTIFICATION OF POCKLINGTON'S EQUATION
Authors: CLAEYS XAVIER
Published: July 2009

Pocklington's model consists in a one-dimensional integral equation relating the current at the surface of a straight finite wire to the tangential trace of an incident electromagnetic field. It is a simplification of the more usual single layer potential equation posed on a two-dimensional surface. We are interested in estimating the error between the solution of the exact integral equation and the solution of Pocklington's model. We address this problem for the model case of acoustics in a smooth geometry using results of asymptotic analysis.
STUDY OF THE η-7Be INTERACTION NEAR THRESHOLD IN p-6Li FUSION
Authors: UPADHYAY N. J. , KELKAR N. G. , KHEMCHANDANI K. P. , JAIN B. K.
Published: July 2009

We present a calculation for η production in the p-6Li fusion near threshold including the η-7Be final state interaction (FSI). We consider the 6Li and 7Be nuclei as α-d and α-3He clusters respectively. The calculations are done for the lowest states of 7 Be with [Formula: see text] resulting from the L = 1 radial wave function. The η-7Be interaction is incorporated through the η-7BeT–matrix, constructed from the medium modified matrices for the η-3He and η-α systems. These medium modified matrices are obtained by solving few body equations, where the scattering in nuclear medium is taken into account.
Optimal dynamic vertical ray shooting in rectilinear planar subdivisions
Authors: Giora Yoav , Kaplan Haim
Published: July 2009

We consider the dynamic vertical ray shooting problem against horizontal disjoint segments, that is, the task of maintaining a dynamic set
S
of
n
nonintersecting horizontal line segments in the plane under a query that reports the first segment in
S
intersecting a vertical ray from a query point. We develop a linear-size structure that supports queries, insertions, and deletion in
O
(log
n
) worst-case time. Our structure works in the comparison model on a random access machine.
Distributed middleware framework using aspects
Authors: Dahiya Deepak , Batra Usha
Published: July 2009

In this paper we discuss the characteristics of Aspect Oriented Programming (AOP) and the need to introduce aspects for distributed computing. The evolution of a revolutionary programming paradigm that promises to have a profound effect on the way we interact with computers, people and places is now a days well known as Aspect Oriented Programming. Middleware platforms, such as RMI, CORBA, DCOM, J2EE and .NET platform, offer abstractions for the complex distributed environment. Distributed middleware [1,2,3,4] are difficult to build and implement because the distributed frameworks impose a large code overhead due to the specific distributed systems programming conventions. Further, this paper discusses the impact of AOP on the distributed computing environment and hence its contribution towards the design of a distributed middleware framework.
Version management and composition of software components in different phases of software development life cycle
Authors: Kaur Parminder , Singh Hardeep
Published: July 2009

The key factor of component-based software development is the composition of pre-fabricated components. Although research efforts have focused on this issue, yet the optimal performance of component-based systems has not been achieved. If the concept of version management is introduced along with composition technology then it will help in locating the component mismatch in the earlier stages of software development life cycle. This paper analyses the significance of version management and composition of software components in different phases like analysis phase, design phase and deployment phase of software development life cycle. A comparative analysis of different available component models like COM, .NET, Enterprise JavaBeans (EJB), CORBA, SOFA, UML 2.0 and Web Services with respect to these two issues is also discussed.
Component assessment and proactive model for support of dynamic integration in self adaptive system
Authors: Mishra Arun , Misra A. K.
Published: July 2009

Component Based Software Engineering (CBSE) is a paradigm in use by most of the software developers. In a multi component system, each component is a probable point of malfunction. Typical work to make such system more vigorous and safe are both brittle and time intense. A model has been designed for self-adaptive system that automates the component integration process at runtime by accessing the equivalent component from diversified set of components that may be needed in future. The proposed general model is for proactive adaptation, which pre-fetch the component from the pre available repository. This model integrates the caching technique to reduce the amount of time that has been spent during search of best-fitted component to replace the required one, when a system fails to respond due to component failure. To pre-fetch the required component we perform the component assessment on the basis of numerical metadata for each component present in the repository. In the computation of numerical metadata we design an algorithm which uses the concept of Abstract Syntax Tree. To ensure the consistency in the system after the modification, we have used a technique which is used in GUI based component architecture model. To asses the component at run-time, we provide prototype in .Net technology using its attribute feature, which support run-time component evolution without its execution.
Inspired software design early jackson methods to thread architectures
Authors: Sandén Bo
Published: July 2009

This is a somewhat personal account of a journey starting with assembly coding based on
Jackson Structured Programming (JSP)
and ending with the design of thread architectures for reactive software systems using
entity-life modeling (ELM)
. As the level of abstraction rises, the basic concepts remain the same: The software takes its shape from structures in the problem domain. JSP bases control structures on regular expressions describing data streams.
Jackson System Development (JSD)
introduces long-running processes patterned on the life histories of entities in the problem domain. Unfortunately, implementing long-running processes in sequential programs leads to awkward solutions. ELM lets us im-plement the processes as threads. This is a natural fit, which re-moves the awkwardness.
Dependency analysis for component-based software systems
Authors: Sharma Arun , Grover P. S. , Kumar Rajesh
Published: July 2009

Interaction in component-based systems (CBS) happens when a component provides an interface and other components use it, and also when a component submits an event and other component receives it. Interactions promote dependencies. Higher dependency leads to a complex system, which results in poor understanding and a higher maintenance cost. Usually, dependency is represented by an adjacency matrix used in graph theory. However, this representation can check only for the presence of dependency between components and does not consider the type of interactions between these components. Interaction type can have a significant contribution to the complexity of the system. This paper proposes a link-list based dependency representation and implements it by using Hash Map in Java. This representation can store the dependency along with other information like, provided and required interfaces of components along with their types. This information can be used to analyze several interaction and dependency related issues. This paper also presents the results of an experiment of the proposed approach and measures the interaction densities and dependency level of an individual component and for the system The results show that the proposed metrics can also be used to identify the most critical and isolated components in the system, which can lead to better understanding and easy system maintenance.
Advances in multicore software engineering
Authors: Pankratius Victor , Porter Adam , Votta Larry
Published: July 2009

In the beautiful city of Vancouver, ICSE2009 hosted several events devoted to advancing the state-of-the-art in multicore software engineering. Realizing that future performance increases will come form parallelism, the software engineering community is organizing to tackle the problems in this important field. Researchers and practitioners got together to present newest results and discuss future directions.
The Pathologies of Big Data
Authors: Jacobs Adam
Published: July 2009

What is "big data" anyway? Gigabytes? Terabytes? Petabytes? A brief personal memory may provide some perspective. In the late 1980s at Columbia University I had the chance to play around with what at the time was a truly enormous "disk": the IBM 3850 MSS (Mass Storage System). The MSS was actually a fully automatic robotic tape library and associated staging disks to make random access, if not exactly instantaneous, at least fully transparent. In Columbia’s configuration, it stored a total of around 100 GB. It was already on its way out by the time I got my hands on it, but in its heyday, the early to mid-1980s, it had been used to support access by social scientists to what was unquestionably "big data" at the time: the entire 1980 U.S. Census database.
Information technology in social entrepreneurship
Authors: Burley Diana
Published: July 2009

Social entrepreneurship is increasingly seen as a critical component of the global conversation on volunteerism and civic engagement. The purpose of this article is to lay the groundwork for a larger conversation on the role of information technology in social entrepreneurship by summarizing the discussions among participants of a recent conference on the subject. Social networking and information sharing were identified as the most critical roles of IT in support of social entrepreneurship. However, in order to realize the full potential of these roles, conference participants suggested that four key challenges must be addressed: access, capacity, commonality, and the scholar-practitioner link.
Ethical awareness of computer use among undergraduate students
Authors: Masrom Maslin , Ismail Zuraini , Hussein Ramlah
Published: July 2009

This study investigates the ethical awareness of computer use among undergraduate computer science students at two public Malaysian universities. One hundred and fifty-nine students were asked to evaluate the code of ethics pertaining to computer ethics. A comparison of undergraduate computer science students between two public universities was done to determine the level of ethical awareness of computer use. Independent Samples
t-tests
for differences were performed across four distinct groups: university, gender, age, and duration of computer use. The results of the tests conducted indicate that the ethical awareness of computer use of the students differ most significantly on the basis of the university itself. There were minimal differences across gender, age and duration of computer use. This suggests that computer ethics awareness training is needed for university users. The results are discussed and the implications for studies in an educational context are outlined.
Central NMU signaling in body weight and energy balance regulation: evidence from NMUR2 deletion and chronic central NMU treatment in mice
Authors: Egecioglu Emil , Ploj Karolina , Xu Xiufeng , Bjursell Mikael , Salomé Nicolas , Andersson Niklas , Ohlsson Claes , Taube Magdalena , Hansson Caroline , Bohlooly-Y Mohammad , Morgan David G. A. , Dickson Suzanne L.
Published: July 2009

To investigate the role of the central neuromedin U (NMU) signaling system in body weight and energy balance regulation, we examined the effects of long-term intracerebroventricular (icv) infusion of NMU in C57Bl/6 mice and in mice lacking the gene encoding NMU receptor 2. In diet-induced obese male and female C57BL/6 mice, icv infusion of NMU (8 μg·day−1·mouse−1) for 7 days decreased body weight and total energy intake compared with vehicle treatment. However, these parameters were unaffected by NMU treatment in lean male and female C57BL/6 mice fed a standard diet. In addition, female (but not male) NMUR2-null mice had increased body weight and body fat mass when fed a high-fat diet but lacked a clear body weight phenotype when fed a standard diet compared with wild-type littermates. Furthermore, female (but not male) NMUR2-null mice fed a high-fat diet were protected from central NMU-induced body weight loss compared with littermate wild-type mice. Thus, we provide the first evidence that long-term central NMU treatment reduces body weight, food intake, and adiposity and that central NMUR2 signaling is required for these effects in female but not male mice.
Mouse GLUT9: evidences for a urate uniporter
Authors: Bibert Stéphanie , Hess Solange Kharoubi , Firsov Dmitri , Thorens Bernard , Geering Käthi , Horisberger Jean-Daniel , Bonny Olivier
Published: July 2009

GLUT9 (SLC2A9) is a newly described urate transporter whose function, characteristics, and localization have just started to be elucidated. Some transport properties of human GLUT9 have been studied in the Xenopus laevis oocyte expression system, but the type of transport (uniport, coupled transport system, stoichiometry … .) is still largely unknown. We used the same experimental system to characterize in more detail the transport properties of mouse GLUT9, its sensitivity to several uricosuric drugs, and the specificities of two splice variants, mGLUT9a and mGLUT9b. [14C]urate uptake measurements show that both splice variants are high-capacity urate transporters and have a Km of ∼650 μM. The well-known uricosuric agents benzbromarone (500 μM) and losartan (1 mM) inhibit GLUT9-mediated urate uptake by 90 and 50%, respectively. Surprisingly, phloretin, a glucose-transporter blocker, inhibits [14C]urate uptake by ∼50% at 1 mM. Electrophysiological measurements suggest that urate transport by mouse GLUT9 is electrogenic and voltage dependent, but independent of the Na+ and Cl− transmembrane gradients. Taken together, our results suggest that GLUT9 works as a urate (anion) uniporter. Finally, we show by RT-PCR performed on RNA from mouse kidney microdissected tubules that GLUT9a is expressed at low levels in proximal tubules, while GLUT9b is specifically expressed in distal convoluted and connecting tubules. Expression of mouse GLUT9 in the kidney differs from that of human GLUT9, which could account for species differences in urate handling.
Multilevel Simulation of Heterogeneous Reconfigurable Platforms
Authors: Picard Damien , Lagadec Loic
Published: July 2009

This paper presents a general system‐level simulation and testing methodology for reconfigurable System‐on‐Chips, starting from behavioral specifications of system activities to multilevel simulations of accelerated tasks running on the reconfigurable circuit. The system is based on a common objectoriented environment that offers valuable debugging and probing facilities as well as integrated testing features. Our system brings these benefits to the hardware simulation, while enforcing validation through characterization tests and interoperability through on‐demand mainstream tools connections. This framework has been partially developed in the scope of the EU Morpheus project and is used to validate our contribution to the spatial design task.
The Use of MTM-SVD Technique to Explore the Joint Spatiotemporal Modes of Wind and Sea Surface Variability in the North Indian Ocean during 1993–2005
Authors: Rojsiraphisal Thaned , Rajagopalan Balaji , Kantha Lakshmi
Published: July 2009

Sea surface height (SSH) and sea surface temperature (SST) in the North Indian Ocean are affected predominantly by the seasonally reversing monsoons and in turn feed back on monsoon variability. In this study, a set of data generated from a data-assimilative ocean model is used to examine coherent spatiotemporal modes of variability of winds and surface parameters using a frequency domain technique, Multiple Taper Method with Singular Value Decomposition (MTM-SVD). The analysis shows significant variability at annual and semiannual frequencies in these fields individually and jointly. The joint variability of winds and SSH is significant at interannual (2-3 years) timescale related to the ENSO mode—with a “/dipole/” like spatial pattern. Joint variability with SST showed similar but somewhat weaker behavior. Winds appear to be the driver of variability in both SSH and SST at these frequency bands. This offers prospects for long-lead projections of the North Indian Ocean climate.
The Dynamics of the Pulse Birth in an SIR Epidemic Model with Standard Incidence
Authors: Zhang Juping , Jin Zhen , Xue Yakui , Li Youwen
Published: July 2009

An SIR epidemic model with pulse birth and
standard incidence is presented. The dynamics of the epidemic model
is analyzed. The basic reproductive number R∗ is defined. It is
proved that the infection‐free periodic solution is global asymptotically stable if R∗ < 1. The infection‐free periodic
solution is unstable and the disease is uniform persistent if R∗ > 1. Our theoretical results are confirmed by numerical simulations.
Compact Operators Defined on 2‐Normed and 2‐Probabilistic Normed Spaces
Authors: Lael Fatemeh , Nourouzi Kourosh
Published: July 2009

The compact operators defined on 2‐normed
spaces are investigated, and then the main ideas are generalized to operators
defined on 2‐probabilistic normed spaces.
Tonic Pupil Following Pars Plana Vitrectomy and Endolaser
Authors: Ebrahim Benyamin , Frohman Larry , Zarbin Marco , Bhagat Neelakshi
Published: July 2009

Tonic pupil was observed in a 67 year-old patient following a retinal detachment repair with pars plana vitrectomy, endolaser and silicone oil tamponade performed under retrobulbar anesthesia. The probable location of disturbance is the postganglionic parasympathetic fibers in the short ciliary nerves along their course to the pupil in the suprachoroidal space. A likely explanation for this phenomenon is injury to short ciliary nerves by endolaser treatment.
Overexpression of Platelet-Derived Growth Factor-BB Increases Tumor Pericyte Content via Stromal-Derived Factor-1α/CXCR4 Axis
Authors: Song Nan , Huang Yujie , Shi Hubing , Yuan Shaopeng , Ding Yanping , Song Xiaomin , Fu Yan , Luo Yongzhang
Published: July 2009

Platelet-derived growth factor-BB (PDGF-BB) is a well-characterized growth factor displaying potent biological effects on angiogenesis. Recent studies reveal that overexpression of PDGF-BB within tumors results in increased pericyte coverage, suggesting that PDGF-BB signaling is also essential for the cancerous pericyte recruitment process. However, the molecular mechanism underlying this regulation remains obscure. In the current study, we show that tumor-derived PDGF-BB induces SDF-1α expression in endothelial cells (EC), resulting in the formation of SDF-1α chemotaxis gradient, which coincides with the PDGF-BB–induced pericyte recruitment during angiogenesis. PDGF-BB dramatically up-regulates SDF-1α secretion through the activation of PDGFRβ in tumor-associated ECs, whereas this up-regulation can be substantially inhibited by either blockade of the phosphatidylinositol 3-kinase/Akt/mTOR pathway with chemical inhibitors or the inactivation of HIF-1α through small interfering RNA interference. On the other hand, we reveal that SDF-1α can increase pericytes motility in vitro. Blockade of the SDF-1α/CXCR4 axis prevents the PDGF-BB–induced pericyte recruitment not only in three in vitro recruitment models but also in the PDGF-BB–overexpressing tumor xenograft models. These results highlight that the involvement of SDF-1α/CXCR4 axis is essential for the pericyte recruitment within the PDGF-BB–overexpressing tumors and raise the possibility that blockade of the SDF-1α/CXCR4 axis may provide a therapeutic synergy with antiangiogenic molecules that selectively target ECs. [Cancer Res 2009;69(15):6057–64]
Epithelial to Mesenchymal Transition Contributes to Drug Resistance in Pancreatic Cancer
Authors: Arumugam Thiruvengadam , Ramachandran Vijaya , Fournier Keith F. , Wang Huamin , Marquis Lauren , Abbruzzese James L. , Gallick Gary E. , Logsdon Craig D. , McConkey David J. , Choi Woonyoung
Published: July 2009

A better understanding of drug resistance mechanisms is required to improve outcomes in patients with pancreatic cancer. Here, we characterized patterns of sensitivity and resistance to three conventional chemotherapeutic agents with divergent mechanisms of action [gemcitabine, 5-fluorouracil (5-FU), and cisplatin] in pancreatic cancer cells. Four (L3.6pl, BxPC-3, CFPAC-1, and SU86.86) were sensitive and five (PANC-1, Hs766T, AsPC-1, MIAPaCa-2, and MPanc96) were resistant to all three agents based on GI50 (50% growth inhibition). Gene expression profiling and unsupervised hierarchical clustering revealed that the sensitive and resistant cells formed two distinct groups and differed in expression of specific genes, including several features of “epithelial to mesenchymal transition” (EMT). Interestingly, an inverse correlation between E-cadherin and its transcriptional suppressor, Zeb-1, was observed in the gene expression data and was confirmed by real-time PCR. Independent validation experiment using five new pancreatic cancer cell lines confirmed that an inverse correlation between E-cadherin and Zeb-1 correlated closely with resistance to gemcitabine, 5-FU, and cisplatin. Silencing Zeb-1 in the mesenchymal lines not only increased the expression of E-cadherin but also other epithelial markers, such as EVA1 and MAL2, and restored drug sensitivity. Importantly, immunohistochemical analysis of E-cadherin and Zeb-1 in primary tumors confirmed that expression of the two proteins was mutually exclusive (P = 0.012). Therefore, our results suggest that Zeb-1 and other regulators of EMT may maintain drug resistance in human pancreatic cancer cells, and therapeutic strategies to inhibit Zeb-1 and reverse EMT should be evaluated. [Cancer Res 2009;69(14):5820–8]
Computational Identification of a p38SAPK-Regulated Transcription Factor Network Required for Tumor Cell Quiescence
Authors: Adam Alejandro P. , George Ajish , Schewe Denis , Bragado Paloma , Iglesias Bibiana V. , Ranganathan Aparna C. , Kourtidis Antonis , Conklin Douglas S. , Aguirre-Ghiso Julio A.
Published: July 2009

The stress-activated kinase p38 plays key roles in tumor suppression and induction of tumor cell dormancy. However, the mechanisms behind these functions remain poorly understood. Using computational tools, we identified a transcription factor (TF) network regulated by p38α/β and required for human squamous carcinoma cell quiescence in vivo. We found that p38 transcriptionally regulates a core network of 46 genes that includes 16 TFs. Activation of p38 induced the expression of the TFs p53 and BHLHB3, while inhibiting c-Jun and FoxM1 expression. Furthermore, induction of p53 by p38 was dependent on c-Jun down-regulation. Accordingly, RNAi down-regulation of BHLHB3 or p53 interrupted tumor cell quiescence, while down-regulation of c-Jun or FoxM1 or overexpression of BHLHB3 in malignant cells mimicked the onset of quiescence. Our results identify components of the regulatory mechanisms driving p38-induced cancer cell quiescence. These may regulate dormancy of residual disease that usually precedes the onset of metastasis in many cancers. [Cancer Res 2009;69(14):5664–72]
Kruppel-Associated Box Domain-Associated Protein-1 as a Latency Regulator for Kaposi's Sarcoma-Associated Herpesvirus and Its Modulation by the Viral Protein Kinase
Authors: Chang Pei-Ching , Fitzgerald Latricia D. , Van Geelen Albert , Izumiya Yoshihiro , Ellison Thomas J. , Wang Don-Hong , Ann David K. , Luciw Paul A. , Kung Hsing-Jien
Published: July 2009

Kaposi's sarcoma-associated herpesvirus (KSHV) has been linked to the development of Kaposi's sarcoma, a major AIDS-associated malignancy, and to hematologic malignancies, including primary effusion lymphoma and multicentric Castleman's disease. Like other herpesviruses, KSHV is capable of both latent and lytic replication. Understanding the molecular details associated with this transition from latency to lytic replication is key to controlling virus spread and can affect the development of intervention strategies. Here, we report that Kruppel-associated box domain-associated protein-1 (KAP-1)/transcriptional intermediary factor 1β, a cellular transcriptional repressor that controls chromosomal remodeling, participates in the process of switching viral latency to lytic replication. Knockdown of KAP-1 by small interfering RNA leads to KSHV reactivation mediated by K-Rta, a key transcriptional regulator. In cells harboring latent KSHV, KAP-1 was associated with the majority of viral lytic-gene promoters. K-Rta overexpression induced the viral lytic cycle with concomitant reduction of KAP-1 binding to viral promoters. Association of KAP-1 with heterochromatin was modulated by both sumoylation and phoshorylation. During lytic replication of KSHV, KAP-1 was phosphorylated at Ser824. Several lines of evidence directly linked the viral protein kinase to this post-translational modification. Additional studies showed that this phosphorylation of KAP-1 produced a decrease in its sumoylation, consequently decreasing the ability of KAP-1 to condense chromatin on viral promoters. In summary, the cellular transcriptional repressor KAP-1 plays a role in regulating KSHV latency, and viral protein kinase modulates the chromatin remodeling function of this repressor. [Cancer Res 2009;69(14):5681–9]
Positive Feedback Activation of Estrogen Receptors by the CXCL12-CXCR4 Pathway
Authors: Sauvé Karine , Lepage Julie , Sanchez Mélanie , Heveker Nikolaus , Tremblay André
Published: July 2009

Induction of estrogen-regulated gene transcription by estrogen receptors ERα and ERβ plays an important role in breast cancer development and growth. High expression of the chemokine receptor CXCR4 and its ligand CXCL12/stromal cell-derived factor 1 (SDF-1) has also been correlated with aggressive breast tumor phenotypes. Here, we describe a positive regulatory loop between the CXCR4/SDF-1 signaling pathway and ER transcriptional competence in human breast cancer cells. Treatment of breast carcinoma MCF-7 cells with SDF-1 increased ER transcriptional activity and expression of ER target genes, including SDF-1 itself. These effects were blocked by the antiestrogen ICI-182780 and by CXCR4 silencing and, conversely, estrogen-induced gene expression and growth of MCF-7 cells were impaired on CXCR4 inhibition. Both ERα and ERβ were activated by SDF-1 in the presence of CXCR4 and by overexpression of a constitutively active CXCR4, indicating that CXCR4 signals to both receptors. In particular, ERβ was able to translate the effects of SDF-1 on its own expression, as well as enhance activator protein 1 (AP-1) containing genes cyclin D1 and c-Myc in the presence of tamoxifen. This correlated with an increased ERβ occupancy of responsive promoters at both estrogen-responsive and AP-1 elements. Ser-87, a conserved mitogen-activated protein kinase site in ERβ, was highly phosphorylated by SDF-1, revealing an essential role of the AF-1 domain in response to CXCR4 activation. These results identify a complete autocrine loop between the CXCR4/SDF-1 and ERα/ERβ signaling pathways that dictates ER-dependent gene expression and growth of breast cancer cells. [Cancer Res 2009;69(14):5793–800]
The Emerging Role of EpCAM in Cancer and Stem Cell Signaling
Authors: Munz Markus , Baeuerle Patrick A. , Gires Olivier
Published: July 2009

Initially discovered as a dominant antigen on colon carcinomas, the epithelial cell adhesion molecule (EpCAM) was considered a mere cell adhesion molecule and reliable surface-binding site for therapeutic antibodies. Recent findings can better explain the relevance of EpCAM's high-level expression on human cancers and cancer propagating cells, and its negative prognostic potential for survival of patients with certain cancers. EpCAM has oncogenic potential and is activated by release of its intracellular domain, which can signal into the cell nucleus by engagement of elements of the wnt pathway. [Cancer Res 2009;69(14):5627–9]
Prevalence of TMPRSS2-ERG Fusion Prostate Cancer among Men Undergoing Prostate Biopsy in the United States
Authors: Mosquera Juan-Miguel , Mehra Rohit , Regan Meredith M. , Perner Sven , Genega Elizabeth M. , Bueti Gerri , Shah Rajal B. , Gaston Sandra , Tomlins Scott A. , Wei John T. , Kearney Michael C. , Johnson Laura A. , Tang Jeffrey M. , Chinnaiyan Arul M. , Rubin Mark A. , Sanda Martin G.
Published: July 2009

Purpose: Fusion of the TMPRSS2 prostate-specific gene with the ERG transcription factor is a putatively oncogenic gene rearrangement that is commonly found in prostate cancer tissue from men undergoing prostatectomy. However, the prevalence of the fusion was less common in samples of transurethral resection of the prostate from a Swedish cohort of patients with incidental prostate cancer followed by watchful waiting, raising the question as to whether the high prevalence in prostatectomy specimens reflects selection bias. We sought to determine the prevalence of TMPRSS2-ERG gene fusion among prostate-specific antigen–screened men undergoing prostate biopsy in the United States.

Experimental Design: We studied 140 prostate biopsies from the same number of patients for TMPRSS2-ERG fusion status with a fluorescent in situ hybridization assay. One hundred and thirty-four samples (100 cancer and 34 benign) were assessable.

Results: ERG gene rearrangement was detected in 46% of prostate biopsies that were found to have prostate cancer and in 0% of benign prostate biopsies (P < 0.0001). Evaluation of morphologic features showed that cribriform growth, blue-tinged mucin, macronucleoli, and collagenous micronodules were significantly more frequent in TMPRSS2-ERG fusion–positive prostate cancer biopsies than gene fusion–negative prostate cancer biopsies (P ≤ 0.04). No significant association with Gleason score was detected. In addition, non-Caucasian patients were less likely to have positive fusion status (P = 0.02).

Conclusions: This is the first prospective North American multicenter study to characterize TMPRSS2-ERG prostate cancer prevalence in a cohort of patients undergoing needle biopsy irrespective of whether or not they subsequently undergo prostatectomy. Our results show that this gene rearrangement is common among North American men who have prostate cancer on biopsy, is absent in benign prostate biopsy, and is associated with specific morphologic features. These findings indicate a need for prospective studies to evaluate the relationship of TMPRSS2-ERG rearrangement with clinical course of screening-detected prostate cancer in North American men, and a need for the development of noninvasive screening tests to detect TMPRSS2-ERG rearrangement.