bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electromagnetic induction calibration using apparent electrical conductivity modelling based on electrical resistivity tomography
Authors: Lavoué F. , van der Krak J. , Rings J. , André F. , Moghadas D. , Huisman J.A. , Lambot S. , Weiherrnüller L. , Vanderborght J. , Vereecken H. 
Published: January 2011

ABSTRACTElectromagnetic parameters of the subsurface such as electrical conductivity are of great interest for non‐destructive determination of soil properties (e.g., clay content) or hydrologic state variables (e.g., soil water content). In the past decade, several non‐invasive geophysical methods have been developed to measure subsurface parameters in situ. Among these methods, electromagnetic (EM) induction appears to be the most efficient one that is able to cover large areas in a short time. However, this method currently does not provide absolute values of electrical conductivity due to calibration problems, which hinders a quantitative analysis of the measurement. In this study, we propose to calibrate EM induction measurements with electrical conductivity values measured with electrical resistivity tomography (ERT). EM induction measures an apparent electrical conductivity at the surface, which represents a weighted average of the electrical conductivity distribution over a certain depth range, whereas ERT inversion can provide absolute values for local conductivities as a function of depth. EM induction and ERT measurements were collected along a 120‐metre‐long transect. To reconstruct the apparent electrical conductivity measured with EM induction, the inverted ERT data were used as input in an electromagnetic forward modelling tool for magnetic dipoles over a horizontally layered medium considering the frequencies and offsets used by the EM induction instruments. Comparison of the calculated and measured apparent electrical conductivities shows very similar trends but a shift in absolute values, which is attributed to system calibration problems. The observed shift can be corrected for by linear regression. This new calibration strategy for EM induction measurements now enables the quantitative mapping of electrical conductivity values over large areas.
2D sections of porosity and water saturation from integrated resistivity and seismic surveys
Authors: Mota R. , Monteiro Santos F.A. 
Published: January 2011

ABSTRACTPorosity and degree of saturation – or the water content – are important parameters for hydrogeological, geotechnical and environmental studies. Geophysical methods, especially the resistivity method, are routinely employed to study the spatial variations of these parameters. Resistivity is highly influenced by the presence of water in pore spaces and hence is well suited for studying the presence of fluids on a site and its saturation condition. However, the non‐uniqueness of the solution of resistivity models has led to the joint use of more than one geophysical method in order to reach more accurate geophysical models. In this research, we combined resistivity and seismic refraction profiles. The integration of these methods was particularly aimed to obtain 2D sections for estimating the porosity, water saturation and volumetric water content rather than to obtain a better geophysical solution.Independently inverted resistivity and P‐wave refraction sections are the input data to an iterative analysis process using simulated annealing. Empirical equations taken from the literature are used to relate both the seismic velocity and the electrical resistivity with porosity and water saturation. Several parameters, such as the resistivity of water and clay; the velocity of water, clay, air and matrix; clay percentage and Archie’s parameters remain constant throughout the process. The values considered for each parameter are derive from both the literature and laboratory measurements.Resistivity and seismic refraction profiles were performed on a site located within the LNEC campus. At this site, field measurements of void ratio and volumetric water content were performed at different depths. Soil samples were also collected at three different depths in order to perform laboratory measurements of these parameters and to determine soil composition. The laboratory results were compared with the 2D sections of each parameter. The proposed approach was also applied to two other locations with different and well characterized geology. These tests also allowed us to characterize the dependency of the clay content on the resistivity.This research has potential fields of application in environmental studies, in particular, the determination of probable pathways of pollutants; in hydrological investigations, where it can be useful to transport of nutrients studies; and in geotechnical studies, where, for example, it will be able to give a continuous image of the saturation degree of an embankment.
Evaluation of the multi‐channel surface wave analysis approach for the monitoring of multiple soil‐stiffening columns
Authors: Madun A. , Jefferson I. , Chapman D.N. , Culshaw M.G. , Foo K.Y. , Atkins P.R. 
Published: January 2011

ABSTRACTSurface wave spectral analysis is a well‐known technique in the characterization of layered media, where individual layers are assumed to be laterally homogeneous. This technique was later extended into the multi‐channel surface wave analysis approach by using an array of sensors to offer higher signal‐to‐noise ratio and faster data collection as well as in aiding the identification of surface wave propagation from the source. The objective of this article is to assess the performance of the MASW technique for the monitoring of multiple soil‐stiffening columns. The key difference in this application is the strong lateral heterogeneity due to the columns, while being relatively homogeneous in depth. The application of this technique may alleviate the constraints associated with traditional field techniques such as plate loading tests, dynamic probing and field vane shear tests. A laboratory‐scale experiment was carried out using materials with controlled properties in order to validate the proposed technique. Two concrete mortar blocks were built, one as a control and another with mild‐steel columns installed. A piezo‐ceramic transducer was acoustically coupled to the block using a padded weight in order to introduce a stepped‐frequency excitation from the surface. Four accelerometers were used to capture the excitation signal. Data were collected from multiple excitations and averaging was then applied to maximize the signal‐to‐noise ratio. By reconfiguration of the exciter and receivers’ arrangement, the area containing the columns was sequentially surveyed. The experimental measurements were processed to obtain the phase velocity as a function of wavelength. Approximated inversion was then applied in order to obtain the phase velocity versus depth and this was repeated for all survey points in order to build a 2D plot of phase‐velocity across the line of survey and with respect to depth. The results provided experimental evidence on the performance of this technique in the assessment of stiffening columns, evaluated against the requirements of spatial resolution of columns, the consistency of phase‐velocities within the columns and the comparison of the measured stiffness profile against known empirical values.
Non‐destructive methodologies for the evaluation of moisture content in sawn timber structures: ground‐penetrating radar and ultrasound techniques
Authors: Rodríguez‐Abad I. , Martínez‐Sala R. , García‐García F. , Capuz‐Lladró R. 
Published: January 2011

ABSTRACTThe moisture content is a critical parameter for most physical and chemical pathologies of timber and, in the case of structural wood, a can be dangerous for any load‐bearing construction. The complexity of evaluating while timber is in use by means of the current methods (oven‐drying and resistance wood meter) led us to test non‐destructive techniques to evaluate this parameter on site.With this in mind, measurements with two non‐destructive techniques, ground‐penetrating radar (GPR) and ultrasound, were carried out on joists of Pinus pinaster Ait. from their initial green state until the point of hygroscopic equilibrium moisture content. In particular, the analysis presented in this paper focuses on the capacity of each technique to register the velocity variations of their waves during the timber drying process.Prior to the GPR analysis, it was necessary to distinguish between differences in the propagation velocity of electromagnetic waves attributable to the wood anisotropy and those due to variations in . The propagation velocity of the electromagnetic waves was always found to be lower when the electrical field was parallel to the grain of the wood than when it was perpendicular to it. However, when the field was perpendicular, its direction whether radial or tangential, did not significantly affect the . The direct measurements illustrate the ability of the GPR technique to characterize the of timber as a clear decrease in the resulted in an increase in the . A strong correlation was obtained between the two parameters with coefficients of determination, .Longitudinal elastic wave velocities were assessed by means of a ultrasound technique during the timber drying process. Despite the fact that the increased with the decreasing of each joist, the determination coefficient between these two variables was very low.The analysis presented in this paper is a successful application of the GPR technique to the study of wood’s physical properties and has a promising future for the non‐destructive, on‐site analysis of timber .
Full‐waveform inversion of cross‐hole ground‐penetrating radar data to characterize a gravel aquifer close to the Thur River, Switzerland
Authors: Klotzsche Anja , van der Kruk Jan , Angelo Meles Giovanni , Doetsch Joseph , Maurer Hansruedi , Linde Niklas 
Published: January 2011

ABSTRACTCross‐hole radar tomography is a useful tool for mapping shallow subsurface electrical properties viz. dielectric permittivity and electrical conductivity. Common practice is to invert cross‐hole radar data with ray‐based tomographic algorithms using first arrival traveltimes and first cycle amplitudes. However, the resolution of conventional standard ray‐based inversion schemes for cross‐hole ground‐penetrating radar (GPR) is limited because only a fraction of the information contained in the radar data is used. The resolution can be improved significantly by using a full‐waveform inversion that considers the entire waveform, or significant parts thereof. A recently developed 2D time‐domain vectorial full‐waveform cross‐hole radar inversion code has been modified in the present study by allowing optimized acquisition setups that reduce the acquisition time and computational costs significantly. This is achieved by minimizing the number of transmitter points and maximizing the number of receiver positions. The improved algorithm was employed to invert cross‐hole GPR data acquired within a gravel aquifer (4–10 m depth) in the Thur valley, Switzerland. The simulated traces of the final model obtained by the full‐waveform inversion fit the observed traces very well in the lower part of the section and reasonably well in the upper part of the section. Compared to the ray‐based inversion, the results from the full‐waveform inversion show significantly higher resolution images. At either side, 2.5 m distance away from the cross‐hole plane, borehole logs were acquired. There is a good correspondence between the conductivity tomograms and the natural gamma logs at the boundary of the gravel layer and the underlying lacustrine clay deposits. Using existing petrophysical models, the inversion results and neutron‐neutron logs are converted to porosity. Without any additional calibration, the values obtained for the converted neutron‐neutron logs and permittivity results are very close and similar vertical variations can be observed. The full‐waveform inversion provides in both cases additional information about the subsurface. Due to the presence of the water table and associated refracted/reflected waves, the upper traces are not well fitted and the upper 2 m in the permittivity and conductivity tomograms are not reliably reconstructed because the unsaturated zone is not incorporated into the inversion domain.
What do students do? Training, research and learning: developing skills for the next generation of near‐surface geophysicists
Authors: Cassidy Nigel J. , Pringle Jamie K. 
Published: January 2011

ABSTRACTIn the past decade, degree programmes throughout Europe have changed dramatically and near‐surface geophysics is now commonly taught as a minor component of other undergraduate geoscience and related degree programmes. As a consequence, there has been a distinct change in the nature, scope and content of geophysical degrees and the skills set that graduates obtain throughout their studies. As an introduction to the Special Issue on Student‐based Research, this commentary article discusses the expectations of employers, the competencies and skills of our undergraduate and postgraduate students and how these have changed over time. We highlight skill gaps and suggest ways in which the near‐surface geophysical community can address these needs in a pragmatic and cost efficient manner. We hope to illustrate that a greater collaboration between industry and academia is the way forward and that innovative, cross‐sector approaches to student learning and research are the solution to at least some of our problems.
Regulatory T Cells Require Mammalian Target of Rapamycin Signaling To Maintain Both Homeostasis and Alloantigen-Driven Proliferation in Lymphocyte-Replete Mice
Authors: Wang Ying , Camirand Geoffrey , Lin Yan , Froicu Monica , Deng Songyan , Shlomchik Warren D. , Lakkis Fadi G. , Rothstein David M. 
Published: January 2011

AbstractRapamycin (Rapa), an immunosuppressive drug that acts through mammalian target of Rapa inhibition, broadly synergizes with tolerogenic agents in animal models of transplantation and autoimmunity. Rapa preferentially inhibits conventional CD4+ Foxp3− T cells (Tconv) and promotes outgrowth of CD4+Foxp3+ regulatory T cells (Treg) during in vitro expansion. Moreover, Rapa is widely perceived as augmenting both expansion and conversion of Treg in vivo. However, most quantitative studies were performed in lymphopenic hosts or in graft-versus-host disease models. We show in this study that in replete wild-type mice, Rapa significantly inhibits both homeostatic and alloantigen-induced proliferation of Treg, and promotes their apoptosis. Together, these lead to significant Treg depletion. Tconv undergo depletion to a similar degree, resulting in no change in the percent of Treg among CD4 cells. Moreover, in this setting, there was no evidence of conversion of Tconv into Treg. However, after withdrawal of Rapa, Treg recover Ag-induced proliferation more quickly than Tconv, leading to recovery to baseline numbers and an increase in the percent of Treg compared with Tconv. These findings suggest that the effects of Rapa on Treg survival, homeostasis, and induction, depend heavily on the cellular milieu and degree of activation. In vivo, the resistance of Treg to mammalian target of Rapa inhibition is relative and results from lymphopenic and graft-versus-host disease models cannot be directly extrapolated to settings more typical of solid organ transplantation or autoimmunity. Moreover, these results have important implications for the timing of Rapa therapy with tolerogenic agents designed to increase the number of Treg in vivo.
Immune Evasion ofMoraxella catarrhalisInvolves Ubiquitous Surface Protein A-Dependent C3d Binding
Authors: Hallström Teresia , Nordström Therése , Tan Thuan Tong , Manolov Taras , Lambris John D. , Isenman David E. , Zipfel Peter F. , Blom Anna M. , Riesbeck Kristian 
Published: January 2011

AbstractThe complement system plays an important role in eliminating invading pathogens. Activation of complement results in C3b deposition (opsonization), phagocytosis, anaphylatoxin (C3a, C5a) release, and consequently cell lysis. Moraxella catarrhalis is a human respiratory pathogen commonly found in children with otitis media and in adults with chronic obstructive pulmonary disease. The species has evolved multiple complement evasion strategies, which among others involves the ubiquitous surface protein (Usp) family consisting of UspA1, A2, and A2 hybrid. In the present study, we found that the ability of M. catarrhalis to bind C3 correlated with UspA expression and that C3 binding contributed to serum resistance in a large number of clinical isolates. Recombinantly expressed UspA1 and A2 inhibit both the alternative and classical pathways, C3b deposition, and C3a generation when bound to the C3 molecule. We also revealed that the M. catarrhalis UspA-binding domain on C3b was located to C3d and that the major bacterial C3d-binding domains were within UspA1299–452 and UspA2165–318. The interaction with C3 was not species specific since UspA-expressing M. catarrhalis also bound mouse C3 that resulted in inhibition of the alternative pathway of mouse complement. Taken together, the binding of C3 to UspAs is an efficient strategy of Moraxella to block the activation of complement and to inhibit C3a-mediated inflammation.
The Dual Functions of IL-1 Receptor-Associated Kinase 2 in TLR9-Mediated IFN and Proinflammatory Cytokine Production
Authors: Wan Youzhong , Kim Tae Whan , Yu Minjia , Zhou Hao , Yamashita Michifumi , Kang Zizhen , Yin Weiguo , Wang Jian-an , Thomas James , Sen Ganes C. , Stark George R. , Li Xiaoxia 
Published: January 2011

Abstract
Bone marrow-derived plasmacytoid dendritic cells (pDCs) from IL-1R–associated kinase (IRAK)2-deficient mice produced more IFNs than did wild-type pDCs upon stimulation with the TLR9 ligand CpG. Furthermore, in CpG-stimulated IRAK2-deficient pDCs there was increased nuclear translocation of IFN regulatory factor 7, the key transcription factor for IFN gene transcription in these cells. In IRAK2-deficient macrophages, enhanced NF-κB activation and increased expression of CpG-induced genes were detected within 2 h after treatment. However, at later times, NF-κB activation was decreased and, in contrast to the results with IFN, there was less secretion of other proinflammatory cytokines (such as TNF-α) and chemokines in CpG-stimulated IRAK2-deficient pDCs and macrophages. Therefore, although IRAK2 is a negative regulator of TLR9-mediated IFN production through its modulation of the transcriptional activity of IFN regulatory factor 7, it is also a positive regulator of TLR9-mediated proinflammatory cytokine and chemokine production at some level subsequent to transcription.
5-Lipoxygenase–Deficient Mice Infected withBorrelia burgdorferiDevelop Persistent Arthritis
Authors: Blaho Victoria A. , Zhang Yan , Hughes-Hanks Jennifer M. , Brown Charles R. 
Published: January 2011

AbstractThe enzyme 5-lipoxygenase (5-LO) catalyzes the conversion of arachidonic acid into the leukotrienes, which are critical regulators of inflammation and inflammatory diseases, such as asthma and arthritis. Although leukotrienes are present in the synovial fluid of Lyme disease patients, their role in the development of Lyme arthritis has not been determined. In the current study, we used a murine model of Lyme arthritis to investigate the role 5-LO products might have in the development of this inflammatory disease. After infection of Lyme arthritis-susceptible C3H/HeJ mice with Borrelia burgdorferi, mRNA expression of 5-LO and 5-LO–activating protein was induced in the joints, and the 5-LO product leukotriene B4 was produced. Using C3H 5-LO–deficient mice, we demonstrated that 5-LO activity was not necessary for the induction of Lyme arthritis, but that its deficiency resulted in earlier joint swelling and an inability to resolve arthritis as demonstrated by sustained arthritis pathology through day 60 postinfection. Although production of anti-Borrelia IgG was decreased in 5-LO–deficient mice, bacterial clearance from the joints was unaffected. Phagocytosis of B. burgdorferi and efferocytosis of apoptotic neutrophils was defective in macrophages from 5-LO–deficient mice, and uptake of opsonized spirochetes by neutrophils was reduced. These results demonstrate that products of the 5-LO metabolic pathway are not required for the development of disease in all models of arthritis and that caution should be used when targeting 5-LO as therapy for inflammatory diseases.
The Haar System in the Preduals of Hyperfinite Factors
Authors: Potapov D. , Sukochev F. 
Published: January 2011

AbstractWe shall present examples of Schauder bases in the preduals to the hyperfinite factors of types II1, II∞, IIIλ, 0 ≤ 1. In the semifinite (respectively, purely infinite) setting, these systems form Schauder bases in any associated separable symmetric space of measurable operators (respectively, in any non-commutative Lp-space).
The Stirrings of a Stubborn and Difficult Freedom: Assimilation, Education, and Levinas’s Crisis of Humanism
Authors: Katz Claire 
Published: January 2011

In several places, Levinas identifies the problem that concerns him as a “crisis of humanism.” This problem finds its seeds in modernity but comes to fruition in the inhumanities of the 20th century. Like his philosophical predecessors, Levinas offers an educational model as a solution to a problem he has identified. But this model--Jewish education—is uniquely different from those offered by those who came before him. This essay examines Levinas‘s interest in Jewish education as a solution to this crisis in humanism and considers what the implications of this solution are for his project as a whole.
Ultrasound Biomicroscopic Assessment of Angle Parameters in Patients with Primary Angle Closure Glaucoma Undergoing Phacoemulsification
Authors: Dada Tanuj , Mohan Shalini , Bali Shveta Jindal , Bhartiya Shibal , Sobti Amit , Panda Anita 
Published: January 2011

Purpose To evaluate the effect of phacoemulsification and foldable intraocular lens (IOL) implantation on biometric determinants of the anterior chamber angle in primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM). Methods Forty-six eyes of 46 patients with chronic PACG and cataract having a patent laser iridotomy were included in this prospective, interventional case series. Angle parameters were measured using UBM before surgery and 3 months after phacoemulsification with IOL implantation. Intraocular pressure (IOP) was measured by applanation tonometer and records of glaucoma medication administered were maintained. Main outcome measures were IOP, central anterior chamber depth (ACD), trabecular iris angle (TIA), and angle opening distance at 250 and 500 μm from scleral spur (AOD250 and AOD500). Results The mean age of study participants was 56.5±9.9 years (range 44–75). The preoperative mean IOP was 25.0±5.4 mmHg on maximum antiglaucoma medication, which was reduced to 15.8±3.8 mmHg (p=0.0001) at 3 months. Number of antiglaucoma medications also decreased from 2.4±1.1 to 0.4±1.1 (p=0.0001). There was a significant widening of the anterior chamber angle with the TIA increasing significantly after phacoemulsification (p<0.001) with an associated increase in AOD250, AOD500, and ACD (p<0.001). Conclusions Phacoemulsification in eyes with PACG results in significant widening of the anterior chamber angle. This results in better IOP control after surgery and decreases the need for glaucoma medications. These findings are of clinical significance in obviating the need for simultaneous filtering surgery in eyes with PACG undergoing phacoemulsification cataract surgery.