bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toward Optimal Choices of Control Space Representation for Geophysical Data Assimilation
Authors: Bocquet Marc 
Published: February 2009

In geophysical data assimilation, observations shed light on a control parameter space through a model, a statistical prior, and an optimal combination of these sources of information. This control space can be a set of discrete parameters, or, more often in geophysics, part of the state space, which is distributed in space and time. When the control space is continuous, it must be discretized for numerical modeling. This discretization, in this paper called a representation of this distributed parameter space, is always fixed a priori. In this paper, the representation of the control space is considered a degree of freedom on its own. The goal of the paper is to demonstrate that one could optimize it to perform data assimilation in optimal conditions. The optimal representation is then chosen over a large dictionary of adaptive grid representations involving several space and time scales. First, to motivate the importance of the representation choice, this paper discusses the impact of a change of representation on the posterior analysis of data assimilation and its connection to the reduction of uncertainty. It is stressed that in some circumstances (atmospheric chemistry, in particular) the choice of a proper representation of the control space is essential to set the data assimilation statistical framework properly. A possible mathematical framework is then proposed for multiscale data assimilation. To keep the developments simple, a measure of the reduction of uncertainty is chosen as a very simple optimality criterion. Using this criterion, a cost function is built to select the optimal representation. It is a function of the control space representation itself. A regularization of this cost function, based on a statistical mechanical analogy, guarantees the existence of a solution. This allows numerical optimization to be performed on the representation of control space. The formalism is then applied to the inverse modeling of an accidental release of an atmospheric contaminant at European scale, using real data.
Role of activated protein C and its receptor in inhibition of tumor metastasis
Authors: Bezuhly Michael , Cullen Robyn , Esmon Charles T. , Morris Steven F. , West Kenneth A. , Johnston Brent , Liwski Robert S. 
Published: February 2009

Abstract
Engagement of endothelial protein C receptor (EPCR) by activated protein C (aPC) decreases expression of endothelial adhesion molecules implicated in tumor-endothelium interactions. We examined the role of the aPC/EPCR pathway on tumor migration and metastasis. In vitro, B16-F10 melanoma cells showed decreased adhesion to and transmigration through endothelium treated with recombinant human aPC (rhaPC). In murine B16-F10 metastasis models, transgenic EPCR overexpressing (Tie2-EPCR) mice exhibited marked reductions in liver (50%) and lung (92%) metastases compared with wild-type (WT) animals. Intravital imaging showed reduced B16-F10 entrapment within livers of Tie2-EPCR compared with WT mice. A similar reduction was observed in WT mice treated with rhaPC. Strikingly, rhaPC treatment resulted in a 44% reduction in lung metastases. This was associated with decreased lung P-selectin and TNF-α mRNA levels. These findings support an important role for the aPC/EPCR pathway in reducing metastasis via inhibition of tumor cell adhesion and transmigration.
Phase III Trial of Cisplatin Plus Gemcitabine With Either Placebo or Bevacizumab As First-Line Therapy for Nonsquamous Non–Small-Cell Lung Cancer: AVAiL
Authors: Reck Martin , von Pawel Joachim , Zatloukal Petr , Ramlau Rodryg , Gorbounova Vera , Hirsh Vera , Leighl Natasha , Mezger Jörg , Archer Venice , Moore Nicola , Manegold Christian 
Published: February 2009

Purpose Bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor, improves survival when combined with carboplatin/paclitaxel for advanced nonsquamous non–small-cell lung cancer (NSCLC). This randomized phase III trial investigated the efficacy and safety of cisplatin/gemcitabine (CG) plus bevacizumab in this setting. Patients and Methods Patients were randomly assigned to receive cisplatin 80 mg/m2 and gemcitabine 1,250 mg/m2 for up to six cycles plus low-dose bevacizumab (7.5 mg/kg), high-dose bevacizumab (15 mg/kg), or placebo every 3 weeks until disease progression. The trial was not powered to compare the two doses directly. The primary end point was amended from overall survival (OS) to progression-free survival (PFS). Between February 2005 and August 2006, 1,043 patients were randomly assigned (placebo, n = 347; low dose, n = 345; high dose, n = 351). Results PFS was significantly prolonged; the hazard ratios for PFS were 0.75 (median PFS, 6.7 v 6.1 months for placebo; P = .003) in the low-dose group and 0.82 (median PFS, 6.5 v 6.1 months for placebo; P = .03) in the high-dose group compared with placebo. Objective response rates were 20.1%, 34.1%, and 30.4% for placebo, low-dose bevacizumab, and high-dose bevacizumab plus CG, respectively. Duration of follow-up was not sufficient for OS analysis. Incidence of grade 3 or greater adverse events was similar across arms. Grade ≥ 3 pulmonary hemorrhage rates were ≤ 1.5% for all arms despite 9% of patients receiving therapeutic anticoagulation. Conclusion Combining bevacizumab (7.5 or 15 mg/kg) with CG significantly improved PFS and objective response rate. Bevacizumab plus platinum-based chemotherapy offers clinical benefit for bevacizumab-eligible patients with advanced NSCLC.
Mixtures of Fine-Grained Minerals — Kaolinite and Carbonate Grains
Authors: Palomino Angelica M. , Burns Susan E. , Santamarina J. Carlos 
Published: February 2009

AbstractThe behavior of mineral mixtures can be significantly different from the behavior of the individual components of the mixture due to differences between the mechanical and chemical properties of the individual minerals, and their ensuing effects on interparticle interactions and fabric formation. This study examines mixtures of kaolinite and calcium carbonate at different mass fractions using sedimentation, viscosity, and liquid-limit tests. These macroscale tests represent a wide range of solid-volume fractions and strain levels, with emphasis on high water-content conditions to magnify the effects of electrical forces. The results demonstrate that interparticle interactions depend on mineral surface-fluid effects, particle geometry, relative particle size, and solids content. With small solids contents, the kaolinite/calcium carbonate mixture behavior is a function of electrostatic interactions between oppositely charged mineral particles that promote flocculation; however, with large solids contents, the specific surface area of the minerals is the controlling factor. These results are relevant to many natural soil environments and to the possible development of engineered mineral mixtures for industrial applications.
The Standard Gibbs Energy of Formation of Fe(II)Fe(III) Hydroxide Sulfate Green Rust
Authors: Ayala-Luis Karina Barbara , Koch Christian Bender , Hansen Hans Christian Bruun 
Published: February 2009

AbstractMixed FeIIFeIII hydroxides, commonly referred to as ‘green rusts’ (GRs), are important reactive phases in both man-made and natural geochemical systems. Determinations of the standard Gibbs energy of formation of GRs are needed to understand and predict the occurrence and possible reactions of GRs in these systems. Slow acid titration of crystalline green rust sulfate (GRSO4\$\end{document}) with the formation of magnetite was used as a novel method to determine the standard Gibbs energy of formation of GRSO4\$\end{document}, ΔfGo(GRSO4)\$\end{document}. Aqueous suspensions of GRSO4\$\end{document}, with pH slightly >8, were titrated slowly with 1 M H2SO4 until pH = 3 under strict anoxic conditions. Powder X-ray diffraction and Mössbauer analysis revealed that magnetite was the only solid phase formed during the initial part of the titration, where the equilibrium pH was maintained above 7.0. The ratio of Fe2+ release to consumption of protons confirmed the stoichiometry of dissolution of GRSO4\$\end{document} and the formation of magnetite at equilibrium conditions. The estimate of the absolute value of ΔfGo(GRSO4)\$\end{document} was −3819.43±6.44 kJ mol−1 + y × [ΔfGo(H2O(1))], where y is the number of interlayer water molecules per formula unit. The logarithm of the solubility product, log Ksp, was estimated to be −139.2±4.8 and is invariable with y. Using the new value for ΔfGo(GRSO4)\$\end{document}, the reduction potentials of several GRSO4\$\end{document}-Fe oxide couples were evaluated, with the GRSO4\$\end{document}-magnetite half cell showing the smallest redox potential at pH 7 and free ion activities of 10−3.
The Synthesis of a Platy Chabazite Analog From Delaminated Metakaolin with the Ability to Surface Template Nanosilver Particulates
Authors: Kuznicki Steven M. , Lin Christopher C. H. , Wu Lan , Yin Haiyan , Danaie Mohsen , Mitlin David 
Published: February 2009

AbstractMineral chabazite has shown the unusual ability to surface template nanometal particles, especially Ag. A chabazite analog was synthesized from delaminated metakaolin. The chabazite formed retained the platy morphology of the base clay. This morphology is ideal for displaying surface-supported nanometal particles. The synthetic chabazite analog demonstrated the ability to form and support large concentrations of Ag nanoparticles, as observed in the related natural mineral. Due to greater Al content, the synthetic chabazite manifests significantly improved capacity for the formation of such Ag nanoparticles. As in the case of the mineral chabazite, surface Ag nanoparticles of high uniformity were observed in the range of 5–6 nm.
Sedimentological and Mineralogical Investigation of the Late Miocene Successions of Aktoprak Basin (Central Turkey): Implications for Sediment Source and Paleoclimates
Authors: Gürel Ali 
Published: February 2009

AbstractLate Miocene (Messinian) alluvial and lacustrine deposits characterize the so-called Kızılbayır Formation of the Aktoprak Basin (central Turkey) and consist of conglomerate, sandstone, mudstone, limestone, marl, and dolomite units. These sediments are composed mainly of feldspar, quartz, hornblende, diopside, olivine, serpentine, calcite, and dolomite with subordinate palygorskite, chlorite, smectite, and illite. Studies by scanning electron microscopy indicate that calcite and dolomite show both meniscus and micrite-sparite-type cements, characteristic of both vadose and phreatic zones. Chlorite, smectite, and illite are products of the alteration of the underlying Güney Formation with subsequent transportation by local streams into the Kızılbayır Formation, and therefore these are considered to be reworked materials. Authigenic palygorskite and dolomite formed as a result of the calcretion of mudstone-carbonate units under alkaline conditions, with high Si, Ca, and Mg activity, and low Al, originated from ophiolitic and carbonate units based on the increase in Ni and Co. The paragenesis and textural features of the minerals of the alluvial fan and lacustrine sediments determined in the study area indicate that precipitation probably occurred due to climate fluctuations ranging from arid and semi-arid to wet conditions.
Tracer Diffusion in Sintered Stainless Steel Filters: Measurement of Effective Diffusion Coefficients and Implications for Diffusion Studies with Compacted Clays
Authors: Glaus Martin A. , Rossé Roger , Van Loon Luc R. , Yaroshchuk Andriy E. 
Published: February 2009

AbstractThe use of porous filters is indispensable in laboratory- and field-scale diffusion studies, where sample confinement is needed for mechanical reasons. Examples are diffusion studies with compacted swelling clays or brittle clay stones. Knowledge of the diffusion properties of these filters is important in cases where they contribute significantly to the overall diffusive resistance in the experimental setup. In the present study, measurements of effective diffusion coefficients (Db) in porous, stainless steel filter discs are reported for tritiated H2O (HTO), 22Na+, Cs+, and Sr2+ before and after use of the filters in diffusion experiments with different clay minerals. The Db values for used filters were found to be less than those of the as-received filters by ∼30–50%. The Db values measured for the diffusion of HTO, 22Na+, Cs+, and Sr2+ in unused and used stainless steel filter discs correlated fairly well with the respective molecular diffusion coefficients in bulk water. Although such correlations are inherently associated with some uncertainties, they allow reasonable estimates to be made for diffusants for which no Db values are available. For the first time, a procedure is outlined that allows an integrative assessment to be made for the impact of the uncertainties in the filter diffusion properties on the combined standard uncertainties of the diffusion parameters obtained from through-diffusion experiments. This procedure can be used in the design and optimization of through-diffusion experiments in which the diffusive resistance of the porous filters must not be ignored. Shown here, as a general rule of thumb, is that, if the effective diffusion coefficient in the porous filter is at least three times larger than that in the clay, the choice of geometrical boundary conditions is rather uncritical, as long as the thickness of the clay sample is greater than that of the porous filters.
Medicinal Clay and Spiritual Healing
Authors: Ferrell Ray E. 
Published: February 2009

AbstractThe varied mineralogical composition of earthy materials and the quantity of elements extracted by simulated stomach acid substantiate the diversity of materials consumed by humans practicing geophagy. Direct consumption of ‘edible earths’ for medicinal and spiritual purposes occurs worldwide and is deeply rooted in ‘folk medicine’ and religion. The legends associated with the healing powers of the clay from Chimayo, New Mexico, provide an excellent example of the roots of geophagy. The clay mineral assemblages revealed by X-ray diffraction analysis of 22 samples from New Mexico, North America, and other parts of the world are highly variable. One might be monominerallic kaolinite or smectite, and another, a complex mixture of illite, kaolinite, smectite, and chlorite or vermiculite. The quantities of elements (Al, Si, K, Na, Ca, Mg, Fe, Mn, Ti, P, S, Ba, Sr, Pb, Zn, Cd, Co, Cu, Cr, Ni, V, Zr, Se, Mo, Be, Sb, and As) extracted by 0.12 M HCl varied from ∼1.0 mg/g to the limit of detectability, 0.0001 mg/g. Potential long-term human health effects were evaluated with the Reference Dose Ratio (RDR). It divides the quantity of the element extracted from 50 g of the total sample by the recommended reference dose (RfD) reported in the Environmental Protection Agency’s (EPA, USA) IRIS (Integrated Risk Information System) database. Median RDR values for Na, Cr, Sb, and As exceeded 1.0 indicating an abnormally high potential intake. Materials consumed by humans are so varied that caution should be used in comparing the results of one clay study with those of another without mineralogical and chemical data.
Sensitivity of Road Unevenness Indicators to Road Waviness
Authors: Múčka Peter , Kropáč Oldřich 
Published: February 2009

Abstract
Currently used single-number indicators of longitudinal road unevenness suffer from their nonuniqueness due to the ignorance of waviness, which is the measure of wavelength distribution in road profile spectrum. Six single-number unevenness indicators were taken into account, viz. unevenness index, straightedge index, International Roughness Index for two velocities (80 and 120 km/h), spectral evenness index, and equivalent unevenness index. A simulation study was conducted, in which the waviness varied in the range from w = 1.5 to 3.5. In addition two representative road vehicles, a personal car and a truck, and three different travel speeds v = 60, 90, and 120 km/h were considered. The ranges of ten different vibration responses were established and related to the reference. The lowest sensitivity to varying waviness has been found for an equivalent unevenness index, which is the standard unevenness index multiplied by a correction factor accounting for the influence of waviness, and for IRI estimated for v = 120 km/h.
Effect of Anti‐Infective Mechanical Therapy on Clinical Parameters and Cytokine Levels in Human Peri‐Implant Diseases
Authors: Duarte Poliana Mendes , de Mendonça Adriana Cutrim , Máximo Maria Beatriz Braz , Santos Vanessa Renata , Bastos Marta Ferreira , Nociti Francisco Humberto 
Published: February 2009

Background: The objectives of this study were to clinically and immunologically assess the effects of mechanical anti‐infective therapies for mucositis and peri‐implantitis and to compare the levels of cytokines in untreated and treated peri‐implant diseased sites to healthy ones.Methods: Titanium dental implants were assigned to one of the following groups: healthy (n = 10) = control; mucositis (n = 10) = mechanical debridement using abrasive sodium carbonate air‐powder and resin curets; and peri‐implantitis (n = 20) = open surgical debridement using abrasive sodium carbonate air‐powder and resin curets. Visible plaque accumulation, marginal bleeding, bleeding on probing, suppuration, and probing depth were assessed at baseline for all groups and at 3 months after therapies for diseased groups. At these times, the total amounts of interleukin (IL)‐4, −10, and −12, tumor necrosis factor‐alpha (TNF‐α), receptor activator of nuclear factor‐kappa B ligand (RANKL), and osteoprotegerin (OPG) in the peri‐implant crevicular fluid (PICF) were measured by enzyme‐linked immunosorbent assay.Results: At 3 months, the anti‐infective treatments resulted in a significant improvement in all clinical parameters for mucositis and peri‐implantitis (P <0.05). Moreover, the total amounts of TNF‐α in PICF were significantly higher in untreated diseased implants compared to healthy ones, and the OPG/RANKL ratio was higher for healthy implants than for untreated peri‐implantitis (P <0.05). TNF‐α levels were significantly reduced for both diseased groups (P <0.05), achieving the same level as the healthy group at 3 months after therapies (P >0.05).Conclusion: The proposed anti‐infective therapies may locally modulate the levels of TNF‐α and the OPG/RANKL ratio and improve clinical parameters around peri‐implant tissues.
Stability of Treated Angular and Horizontal Bony Defects: A Retrospective Radiographic Evaluation in a Private Periodontal Practice
Authors: Greenstein Benjamin , Frantz Bryan , Desai Rishin , Proskin Howard , Campbell Jillian , Caton Jack 
Published: February 2009

Background: This retrospective radiographic evaluation provided a comparative assessment of long‐term alterations of alveolar bone levels at sites with angular and horizontal bony defects that underwent open‐flap debridement and did not undergo resective or regenerative periodontal therapy.Methods: The investigation included 50 patients (27 met inclusion criteria) who had periodontal surgery and periodontal maintenance every 3 to 6 months and who presented with sites demonstrating radiographic angular defects and sites on adjacent or contralateral teeth that demonstrated horizontal bone loss. Subsequent to surgical therapy, alterations in bone levels at the alveolar crest of horizontal defects and at the base of angular defects were evaluated by comparing radiographs from the initial examination to those obtained after a period of periodontal maintenance (6 to 16 years; mean: 8.83 years).Results: After periodontal therapy, sites with angular and horizontal alveolar bone loss had additional bone loss of 5.56% and 3.88%, respectively.Conclusion: Based on a defining criterion of 10%, the angular and horizontal sites were clinically equivalent with respect to the magnitude of osseous resorption that occurred after periodontal surgery and maintenance.
Clinical Evaluation of a Modified Coronally Advanced Flap Alone or in Combination With a Platelet‐Rich Fibrin Membrane for the Treatment of Adjacent Multiple Gingival Recessions: A 6‐Month Study
Authors: Aroca Sofia , Keglevich Tibor , Barbieri Bruno , Gera Istvan , Etienne Daniel 
Published: February 2009

Background: The aim of this study was to determine whether the addition of an autologous platelet‐rich fibrin clot (PRF) to a modified coronally advanced flap (MCAF) (test group) would improve the clinical outcome compared to an MCAF alone (control group) for the treatment of multiple gingival recessions.Methods: Twenty subjects, presenting three adjacent Miller Class I or II multiple gingival recessions of similar extent on both sides of the mouth, were enrolled in the study. The mean recession value at baseline was 2.9 ± 1.1 mm for test sites and 2.5 ± 0.9 mm for control sites. Each patient was treated on both sides by an MCAF technique; the combination treatment (with a PRF membrane) was applied on the test side. Probing depth (PD), recession width, clinical attachment level (CAL), keratinized gingival width, and gingival/mucosal thickness (GTH) were measured at baseline and at 6 months post‐surgery. Gingival recession was measured at baseline and at 1, 3, and 6 months post‐surgery.Results: Mean root coverage after 1, 3, and 6 months was 81.0% ± 16.6%, 76.1% ± 17.7%, and 80.7% ± 14.7%, respectively, at the test sites and 86.7% ± 16.6%, 88.2% ± 16.9%, and 91.5% ± 11.4%, respectively, at the control sites. Differences between the two groups were statistically significant at 3 and 6 months. At 6 months, complete root coverage was obtained at 74.6% of the sites treated with the control procedure but at only 52.2% of the experimental sites. At 6 months, the increase in GTH was statistically significant when comparing the test sites (from 1.1 ± 0.3 mm at baseline to 1.4 ± 0.5 mm at 6 months) to the control sites (from 1.1 ± 0.3 mm at baseline to 1.1 ± 0.3 mm at 6 months). In the case of PD, there was no significant difference between the two groups at 6 months, but a significant CAL gain in favor of the control group was observed at that time.Conclusions: MCAF is a predictable treatment for multiple adjacent Miller Class I or II recession‐type defects. The addition of a PRF membrane positioned under the MCAF provided inferior root coverage but an additional gain in GTH at 6 months compared to conventional therapy.