bluuebunny/crossref_metadata_2025_split huggingface dataset:
The time window of MRI of murine atherosclerotic plaques after administration of CB2 receptor targeted micelles: inter‐scan variability and relation between plaque signal intensity increase and gadolinium content of inversion recovery prepared versus non‐prepared fast spin echo
Authors: te Boekhorst B. C. M. , Bovens S. M. , van de Kolk C. W. A. , Cramer M. J. M. , Doevendans P. A. F. M. , ten Hove M. , van der Weerd L. , Poelmann R. , Strijkers G. J. , Pasterkamp G. , van Echteld C. J. A. 
Published: June 2010

AbstractSingle fast spin echo scans covering limited time frames are mostly used for contrast‐enhanced MRI of atherosclerotic plaque biomarkers. Knowledge on inter‐scan variability of the normalized enhancement ratio of plaque (NERplaque) and relation between NERplaque and gadolinium content for inversion‐recovery fast spin echo is limited. Study aims were: evaluation of (1) timing of MRI after intravenous injection of Cannabinoid‐2 receptor (CB2‐R) (expressed by human and mouse plaque macrophages) targeted micelles; (2) inter‐scan variability of inversion‐recovery fast spin echo and fast spin echo; (3) relation between NERplaque and gadolinium content for inversion‐recovery fast spin echo and fast spin echo. Inversion‐recovery fast spin echo/fast spin echo imaging was performed before and every 15 min up to 48 h after injection of CB2‐R targeted or control micelles using several groups of mice measured in an interleaved fashion. NERplaque (determined on inversion‐recovery fast spin echo images) remained high (∼2) until 48 h after injection of CB2‐R targeted micelles, whereas NERplaque decreased after 36 h in the control group. The inter‐scan variability and relation between NERplaque and gadolinium (assessed with inductively coupled plasma‐ mass spectrometry) were compared between inversion‐recovery fast spin echo and fast spin echo. Inter‐scan variability was higher for inversion‐recovery fast spin echo than for fast spin echo. Although gadolinium and NERplaque correlated well for both techniques, the NER of plaque was higher for inversion‐recovery fast spin echo than for fast spin echo. In mice injected with CB2‐R targeted micelles, NERplaque can be best evaluated at 36–48 h post‐injection. Because NERplaque was higher for inversion‐recovery fast spin echo than for fast spin echo, but with high inter‐scan variability, repeated inversion‐recovery fast spin echo imaging and averaging of the obtained NERplaque values is recommended. Copyright © 2010 John Wiley & Sons, Ltd.
Theoretical models of the diffusion weighted MR signal
Authors: Yablonskiy Dmitriy A. , Sukstanskii Alexander L. 
Published: June 2010

AbstractDiffusion MRI plays a very important role in studying biological tissue structure and functioning both in health and disease. Proper interpretation of experimental data requires development of theoretical models that connect the diffusion MRI signal to salient features of tissue microstructure at the cellular level. In this review, we present some models (mostly, relevant to the brain) for describing diffusion attenuated MR signals. These range from the simplest approach, where the signal is described in terms of an apparent diffusion coefficient, to rather complicated models, where consideration is given to signals originating from extra‐ and intracellular spaces and where account is taken of the specific geometry and orientation distribution of cells. To better understand the characteristics of the diffusion attenuated MR signal arising from the complex structure of whole tissue, it is instructive to appreciate first the characteristics of the signal arising from simple single‐cell‐like structures. For this purpose, we also present here a theoretical analysis of models allowing exact analytical calculation of the MR signal, specifically, a single‐compartment model with impermeable boundaries and a periodic structure of identical cells separated by permeable membranes. Such pure theoretical models give important insights into mechanisms contributing to the MR signal formation in the presence of diffusion. In this review we targeted both scientists just entering the MR field and more experienced MR researchers interested in applying diffusion methods to study biological tissues. Copyright © 2010 John Wiley & Sons, Ltd.
Improved R2* measurement accuracy with absolute SNR truncation and optimal coil combination
Authors: Yin Xiaoming , Shah Saurabh , Katsaggelos Aggelos K. , Larson Andrew C. 
Published: June 2010

AbstractAccurate R2* measurements are critical for many abdominal imaging applications. Conventionally, R2* maps are derived via the monoexponential fitting of signal decay within a series of gradient‐echo (GRE) images reconstructed from multichannel datasets combined using a root sum‐of‐squares (RSS) approach. However, the noise bias at low‐SNR TEs from RSS‐reconstructed data often causes the underestimation of R2* values. In phantom, ex vivo animal model and normal volunteer studies, we investigated the accuracy of low‐SNR R2* measurement when combining truncation and coil combination methods. The accuracy for R2* estimations was shown to be affected by the intrinsic R2* value, SNR level and the chosen reconstruction method. The R2* estimation error was found to decrease with increasing SNR level, decreasing R2* value and the use of the optimal B1‐weighted combined (OBC) image reconstruction method. Data truncation based on rigorous voxel‐wise SNR estimates can reduce R2* measurement error in the setting of low SNR with fast signal decay. When optimal SNR truncation thresholds are unknown, the OBC method can provide optimal R2* measurements given the minimal truncation requirements. Copyright © 2010 John Wiley & Sons, Ltd.
Design of ℋ︁∞ fuzzy controllers for nonlinear systems with random data dropouts
Authors: Zhang Jinhui , Xia Yuanqing 
Published: June 2010

AbstractThe problem of ℋ︁∞ control of nonlinear networked control systems subject to random data dropout is concerned in this paper. The random data dropout, because of the limited bandwidth of the network channels, could exist in the communication channels both from the sensor to the controller and from the controller to the actuator simultaneously. The nonlinear plant is represented by the well‐known Takagi–Sugeno fuzzy model and the random data dropout is expressed by the Bernoulli random binary distribution. In the presence of random data dropout, two control schemes, state feedback and static output feedback, are proposed to design ℋ︁∞ controllers such that the closed‐loop system is stochastically stable and preserves a guaranteed ℋ︁∞ performance. The addressed controller design problem is transformed to an auxiliary convex optimization problem, which can be solved by a linear matrix inequality approach. Three examples are provided to illustrate the applicability and less conservativeness of the developed theoretical results. It is easy to see that our approach is simple but our results are much less conservative than the recently published results. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis, structural, electrochemical, and photophysical properties of 4,2′‐thiopyrylogens – a novel class of sensitizers for photoinduced electron transfer reactions
Authors: Warrier Ajaya Kumar Sankara , Clennan Edward L. 
Published: June 2010

AbstractThe first three examples of the thioanalog of the 4,2′‐pyrylogen ring system are reported. The influence of the sulfur atom on the structural, electrochemical, and photophysical behavior of this ring system is discussed. In addition, these 4,2′‐thiopyrylogens are compared to their previously reported 4,4′‐isomers and their 4,4′‐ and 4,2′‐oxygen analogs. Copyright © 2010 John Wiley & Sons, Ltd.
Remote sensing and field‐based mapping of permafrost distribution along the Alaska Highway corridor, interior Alaska
Authors: Panda Santosh K. , Prakash Anupma , Solie Diana N. , Romanovsky Vladimir E. , Jorgenson M. Torre 
Published: June 2010

AbstractWe employed an integrated approach that combined remote sensing techniques with field measurements to predict the presence/absence of near‐surface permafrost in a section of the Alaska Highway corridor. We investigated the correlative relationships among vegetation type, topography, moss thickness, tussock condition and near‐surface permafrost in the study area. Analysis of moss thickness and active‐layer depth in low‐lying plains (slope <8°) showed an inverse relationship in different vegetation classes. The maximum likelihood classification of remotely sensed data mapped 80% of the study area as covered with vegetation. We developed an empirical‐statistical (Binary Logistic Regression) model to establish the statistical relationship between surface variables and permafrost. The statistical relationships between the surface variables (vegetation, aspect and elevation classes) and permafrost were used within a spatial model to estimate the probability of permafrost presence at any given location (or pixel) in the study area. The statistical model yielded an overall classification accuracy of 80%. The spatial model mapped 62% of the total vegetated area as underlain by permafrost, including 99.5% of the scattered short spruce, 92.5% of the dense tall spruce, and 35.8% of the mixed spruce and deciduous vegetation classes. Comparison of our probabilistic permafrost map with an independently produced photo‐interpreted permafrost map showed 75% agreement for the continuously frozen class and very close agreement for the discontinuously frozen class. Copyright © 2010 John Wiley & Sons, Ltd.
Small gain problem in coupled differential‐difference equations, time‐varying delays, and direct Lyapunov method
Authors: Gu Keqin , Zhang Yashun , Xu Shengyuan 
Published: June 2010

AbstractThis article presents a Lyapunov–Krasovskii formulation of scaled small gain problem for systems described by coupled differential‐difference equations. This problem includes H∞ problem with block‐diagonal uncertainty as a special case. A discretization may be applied to reduce the conditions into linear matrix inequalities. As an application, the stability problem of systems with time‐varying delays is transformed into the scaled small gain problem through a process of either one‐term approximation or two‐term approximation. The cases of time‐varying delays with and without derivative upper‐bound are compared. Finally, it is shown that similar conditions can also be obtained by a direct Lyapunov–Krasovskii functional method for coupled differential‐functional equations. Numerical examples are presented to illustrate the effectiveness of the method in tackling systems with time‐varying delays. Copyright © 2010 John Wiley & Sons, Ltd.
Coherence, contradiction, and the development of school science identities
Authors: Olitsky Stacy , Flohr Linda Loman , Gardner Jessica , Billups Markita 
Published: June 2010

AbstractThis study demonstrates the potential for collaborative research among participants in local settings to effect positive change in urban settings characterized by diversity. It describes an interpretive case study of a racially, ethnically, and socioeconomically diverse eighth grade science classroom in an urban magnet school in order to explore why some of the students did not achieve at high levels and identify with school science although they were both interested in and knowledgeable about science. The results of this study indicated that structural issues such as the school's selection process, the discourses perpetuated by teachers, administrators, and peers regarding “who belongs” at the school, and negative stereotype threat posed obstacles for students by highlighting rather than mitigating the inequalities in students' educational backgrounds. We explore how a methodology based on the use of cogenerative dialogues provided some guidance to teachers wishing to alter structures in their classrooms to be more conducive to all of their students developing identities associated with school science. Based on the data analysis, we also argue that a perspective on classrooms as communities of practice in which learning is socially situated rather than as forums for competitive displays, and a view of students as valued contributors rather than as recipients of knowledge, could address some of the obstacles. Recommendations include a reduced emphasis on standardized tasks and hierarchies, soliciting unique student contributions, and encouraging learning through peripheral participation, thereby enabling students to earn social capital in the classroom. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 1209–1228, 2010
Simulating the aerodynamic performance and wake dynamics of a vertical‐axis wind turbine
Authors: Scheurich Frank , Fletcher Timothy M. , Brown Richard E. 
Published: June 2010

AbstractThe accurate prediction of the aerodynamics and performance of vertical‐axis wind turbines is essential if their design is to be improved but poses a significant challenge to numerical simulation tools. The cyclic motion of the blades induces large variations in the angle of attack of the blades that can manifest as dynamic stall. In addition, predicting the interaction between the blades and the wake developed by the rotor requires a high‐fidelity representation of the vortical structures within the flow field in which the turbine operates. The aerodynamic performance and wake dynamics of a Darrieus‐type vertical‐axis wind turbine consisting of two straight blades is simulated using Brown's Vorticity Transport Model. The predicted variation with azimuth of the normal and tangential force on the turbine blades compares well with experimental measurements. The interaction between the blades and the vortices that are shed and trailed in previous revolutions of the turbine is shown to have a significant effect on the distribution of aerodynamic loading on the blades. Furthermore, it is suggested that the disagreement between experimental and numerical data that has been presented in previous studies arises because the blade–vortex interactions on the rotor were not modelled with sufficient fidelity. Copyright © 2010 John Wiley & Sons, Ltd.
“Big Organisations” Supporting “Small Involvement”: Lessons from Bosnia and Herzegovina on Enabling Community‐Based Participation of Children Through PAR
Authors: Maglajlic Reima Ana 
Published: June 2010

AbstractThe article presents the process and the outcomes of child participatory action research (PAR) conducted in Bosnia and Herzegovina (BiH), as part of UNICEF activities in this country. The study was implemented through children acting as co‐researchers, organised in so‐called Children's PAR Groups, initiated in three BiH municipalities. Children collaborated with a Support Group in each of the municipalities, comprised of adults who helped children implement their activities. Children chose to focus their research on community participation and ensured a number of outcomes in a relatively brief period. The value of PAR in the development of child participation was highlighted by children and adults who took part in the study. Prejudices that children have toward adults, and vice versa, were issues identified as main barriers for wider children's participation. This article also reviews a number of ethical challenges highlighted in the study, such as the organisational barriers to children's participation and project‐based support for its development.
Synthesis, Characterization and Surface Properties of Series Sulfobetaine Surfactants
Authors: Qu Guangmiao , Cheng Jiecheng , Wei Jijun , Yu Tao , Ding Wei , Luan Huoxin 
Published: June 2010

AbstractA series of surface active sulfo‐propane betaines and sulfo‐butane betaines were synthesized with high yields by the reaction of an appropriate N,N‐dimethyl alkylamine with an excess of 1,3‐propane sultone and 1,4‐butane sultone. The structures were characterized by 1H‐NMR spectroscopy and elemental analysis. The micellar properties of these compounds were determined by surface tension methods. Surface tension measurements also provide information about the dependence of the surface tension at the CMC (γcmc), pC20 (negative logarithm of the surfactant molar concentration C20 required to reduce the surface tension by 20 mN/m), the surface excess (Γmax) at air/solution interface, the minimum area per surfactant molecule at the air solution interface (A).
Spontaneous preterm birth in women with chronic hepatitis B virus infection
Authors: Elefsiniotis Ioannis , Tsoumakas Konstantinos , Vezali Elena , Glynou Irene , Drakoulis Nikolaos , Saroglou George 
Published: June 2010

AbstractObjectiveTo determine whether chronic hepatitis B virus (HBV) infection, as evidenced by serum levels of HBsAg and HBV DNA, is a risk factor for spontaneous preterm birth (SPB).MethodThe prevalence of HBV infection and the SPB rate were prospectively investigated among 1826 pregnant women, 30.89% Albanian and the remainder of other European origins.ResultsOverall, 70 (3.8%) of the women were chronically infected with HBV. HBsAg status was strongly linked to SPB, which incurred to 5 (7.3%) of 64 women with circulating HBsAg compared with 28 (1.6%) of 1703 without current HBV infection (odds ratio, 5.2; P = 0.007). SPB, however, was linked neither to HBsAg levels, nor to HBV DNA levels, nor to the presence or absence of viremia.ConclusionPregnant women were found to be at higher risk for SPB if they had circulating HBsAg, and the risk did not seem to be influenced by the levels of HBsAg or HBV DNA.
Lost opportunities for effective management of obstetric conditions to reduce maternal mortality and severe maternal morbidity in Argentina and Uruguay
Authors: Karolinski Ariel , Mazzoni Agustina , Belizán José M. , Althabe Fernando , Bergel Eduardo , Buekens Pierre 
Published: June 2010

AbstractObjectiveTo review the use of evidence‐based practices in the care of mothers who died or had severe morbidity attending public hospitals in two Latin American countries.MethodsThis study is part of a multicenter intervention to increase the use of evidence‐based obstetric practice. Data on maternal deaths and women admitted to intensive care units whose deliveries occurred in 24 hospitals in Argentina and Uruguay were analyzed. Primary outcomes were use rates of effective interventions to reduce maternal mortality (MM) and severe maternal morbidity (SMM).ResultsA total of 106 women were included: 26 maternal deaths and 80 women with SMM. Some effective interventions for severe acute hemorrhage had a high use rate, such as blood transfusion (91%) and timely cesarean delivery (75%), while active management of the third stage of labor (25%) showed a lower rate. The overall use rate of effective interventions was 58% (95% CI, 49%–67%). This implies that 42% of the women did not receive one of the effective interventions to reduce MM and SMM.ConclusionThis study shows a low use of effective interventions to reduce MM and SMM in public hospitals in Argentina and Uruguay. Dissemination and implementation of evidence‐based practices must be guaranteed to effectively achieve progress on maternal health.
The Pragmatic Sources of Modern Power
Authors: Konings Martijn 
Published: June 2010

AbstractMuch work in present-day political economy still adheres to an economistic understanding of how markets operate - evident above all in the tendency to concentrate on the disciplinary and constraining effects of globalization. Using American power in financial affairs as an example, this essay proposes a shift of focus towards the constitution of actor capacities, which will permit more accurate conceptualizations of highly leveraged forms of agency. To this end, it turns to the philosophical foundations of the American pragmatist tradition, exploring the way in which it can inform a deeper understanding of the enabling qualities of institutions, the processes through which actor capacities emerge and the operation of power.
Dispersive magnetized waves in the solar wind plasma
Authors: DASGUPTA B. , SHAIKH DASTGEER , SHUKLA P. K. 
Published: June 2010

AbstractWe derive a generalized linear dispersion relation of waves in a strongly magnetized, compressible, homogeneous and isotropic quasi-neutral plasma. Starting from a two-fluid model, describing distinguishable electron and ion fluids, we obtain a six-order linear dispersion relation of magnetized waves that contains effects due to electron and ion inertia, finite plasma beta and angular dependence of phase speed. We investigate propagation characteristics of these magnetized waves in a regime where scale lengths are comparable with electron and ion inertial length scales. This regime corresponds essentially to the solar wind plasma, where length scales, comparable with ion cyclotron frequency, lead to dispersive effects. These scales in conjunction with linear waves present a great deal of challenges in understanding the high-frequency, small-scale dynamics of turbulent fluctuations in the solar wind plasma.
Zero-temperature limit of one-dimensional Gibbs states via renormalization: the case of locally constant potentials
Authors: CHAZOTTES J.-R. , GAMBAUDO J.-M. , UGALDE E. 
Published: June 2010

AbstractLet A be a finite set and let ϕ:Aℤ→ℝ be a locally constant potential. For each β>0 (‘inverse temperature’), there is a unique Gibbs measure μβϕ. We prove that as β→+∞, the family (μβϕ)β>0 converges (in the weak-* topology) to a measure that we characterize. This measure is concentrated on a certain subshift of finite type, which is a finite union of transitive subshifts of finite type. The two main tools are an approximation by periodic orbits and the Perron–Frobenius theorem for matrices à la Birkhoff. The crucial idea we bring is a ‘renormalization’ procedure which explains convergence and provides a recursive algorithm for computing the weights of the ergodic decomposition of the limit.
Estado de mis investigaciones sobre Pablo de Olavide
Authors: Blas Luis Perdices 
Published: June 2010

Pablo de Qlavide es conocido, en primer lugar, por ser el director de las empresas colonizadoras emprendidas en Andalucía entre 1767 y 1776 y, en segundo lugar, por el «autillo de fe» celebrado en 1778.Cayetano Alcázar Molina es el primero que hace un estudio monográfico destacable sobre Olavide titulado Los hombres del Reinado de Carlos III. Pablo de Olavide (1927). Los estudios publicados entre 1927 y 1959 repiten las ideas de Alcázar Molina. En 1959 Defourneaux publica su libro titulado Pablo de Olavide ou l'afrancesado (1725–1803) (traducido en 1965), que es una de las mejores biografías sobre un pensador del setecientos. De este libro parten todos los estudios posteriores sobre la vida, obra y pensamiento económico de Pablo de Olavide.
La cliometría en Colombia: una revolución interrumpida, 1971–1999
Authors: Roca Adolfo Meisel 
Published: June 2010

RESUMENEste artículo discute los desarrollos en los estudios sobre historia económica de Colombia en los últimos cincuenta años a través de cinco trabajos fundamentales. Durante este período los estudios en este campo han estado dominados por el marxismo, la historia institucional tradicional, los Annales y la dependencia. Sin embargo, en la década de 1990 se ha producido una pérdida de interés por este tema de parte de los historiadores y, simultáneamente, una producción creciente de los economistas que trabajan dentro de la tradición neoclásica.