bluuebunny/crossref_metadata_2025 huggingface dataset:
Four Visions of Constitutional Pluralism
Authors: Avbelj Matej , Komárek Jan
Published: December 2008

What is constitutional pluralism? What does it stand for? What does it expect to achieve, or change in European integration, or otherwise contribute to it? Is it a viable, desirable or perhaps even an indispensable theoretical take on European integration? These were the leading questions discussed in the Symposium ‘Four Visions of Constitutional Pluralism’ at the European University Institute in January of this year. Within the framework of the Legal Theory working group and under the auspices of the Academy of European Law the organisers, Matej Avbelj and Jan Komarek, hosted four key scholars from the field of EU legal and constitutional theory. Julio Baquero Cruz, Mattias Kumm, Miguel Poiares Maduro, and Neil Walker engaged in a groundbreaking three-hour discussion of their respective theoretical visions of European integration. This short note can provide just a taste of an extremely rich debate; however, its full transcript should soon be published by the EUI Department of Law as its working paper.
Bildgebung der Nieren und Harnwege
Authors: Dobry Eduard , Danuser Hansjörg
Published: December 2008

Bildgebende Verfahren sind in der urologischen Diagnostik äußerst wichtig. Bei der akuten Flankenkolik ist die häufigste Ursache ein obstruierender Harnleiterstein, welcher mittels Nativ-Computertomographie (CT) oder alternativ mittels intravenöser Urographie (IVU) abgeklärt wird. Bei Verdacht auf parenchymatösen Nierentumor wird eine CT durchgeführt, bei der Abklärung von Nierenbecken- oder Harnleitertumoren sind jedoch eine IVU gefolgt von einer retrograden Pyelographie mit Gewinnung einer selektiven, lokalen «Spülzytologie» der erste Schritt. Eine CT oder MRT des Abdomens/Beckens ist bei positivem Tumornachweis zum Staging (lokoregionäre oder systemischer Metastasierung?) notwendig und zeigt zudem auch die lokale Tumorsituation. Exophytische oder invasive Prozesse der Harnblase können zwar oft im CT oder Ultraschall gesehen werden, bei Verdacht auf einen Blasentumor ist die Primärdiagnostik aber die Zystoskopie, die durch die Bildgebung nicht ersetzt werden kann. Die Zystographie zeigt Verletzungen der Harnblase oder dient zusammen mit dem Miktionsbild zum Nachweis eines vesikoureteralen Refluxes. Bei Strikturen oder Verletzungen der Harnröhre ist das retro- und anterograde Urethrogramm die Abklärung der Wahl.
Bildgebung von Arterien und Venen
Authors: Frank Ulrich , Reinhart Walter H.
Published: December 2008

Für alle gut einschallbaren Arterien ist die Farbduplexsonographie die Methode der Wahl, weil sie kostengünstig, präzise und ohne Strahlenbelastung ist und neben den morphologischen auch wichtige hämodynamische Informationen liefert. Ausnahme ist die schwer zugängliche Aorta thoracica, bei der die Computertomographie erste Wahl darstellt. Bei der Untersuchung von Venen (Varikose und Thrombose) ist ebenfalls die Farbduplexsonographie erste Wahl und hat die Phlebographie obsolet werden lassen.
Bildgebung der Wirbelsäule, Knochen und Gelenke
Authors: Knüsel Otto
Published: December 2008

Die bildgebenden Verfahren sind ein wichtiger diagnostischer Eckpfeiler bei der Abklärung von Beschwerden des Bewegungsapparates. Dank der Entwicklung in den letzten 100 Jahren hat diese Form der Diagnostik enorme Fortschritte gemacht und sie wird sie weiter machen. Dank der Computertechnologie ist es möglich, nicht nur Abbildungsverfahren zu verfeinern und zu beschleunigen, sondern auch Rekonstruktionen herzustellen, die technisch hervorragend sind und für gewisse operative Indikationen notwendig sein können. Diese Entwicklung provoziert jedoch eine Ausgangssituation, die nicht mehr den heutigen Anforderungen der Wirtschaftlichkeit und Zweckmäßigkeit entspricht. Daher ist es Aufgabe jedes Anwenders dieser Techniken, dass er sich bewusst ist, was er von einer solchen Untersuchung erwarten darf, was die Aussage sein soll und wie er die erhaltenen Befunde zu interpretieren hat. Wir müssen uns bewusst sein, dass bildgebende Verfahren allein nicht eintscheidend sind für die Diagnose und den therapeutisch einzuschlagenden Weg. Es ist vielmehr das ganze Bild des Patienten mit klar erhobener Anamnese und klinischer Untersuchung. Durch diese Maßnahmen können ein Großteil der Diagnosen gestellt und eine Behandlung eingeleitet werden. Aufwändige bildgebende Verfahren haben dann einen Sinn und sind notwendig, wenn eine therapierefraktäre Situation vorliegt oder wenn klar Hinweise für eine systemische Erkrankung vorliegen wie Infektionen, Malignome oder Lähmungen.
Bildgebung beim Kind – was ist speziell?
Authors: Kellenberger Christian J.
Published: December 2008

Dieser Artikel beschreibt für die Bilddiagnostik relevante Merkmale und Besonderheiten von Kindern. Nach anatomischen Lokalisationen gegliedert wird der Einsatz der verschiedenen bildgebenden Verfahren bei typischen pädiatrischen Pathologien diskutiert. Oberstes Gebot in der Bildgebung beim Kind ist die Optimierung und Vermeidung unnötiger oder unnötig hoher Strahlenexposition. Der Ultraschall ist die Basisuntersuchung und oft als einzige bildgebende Modalität ausreichend. Für weitergehende Diagnostik des Abdomens, Zentralnervensystems und muskuloskeletalen Systems ist bei gleicher Aussagekraft eine Magnetresonanztomographie der Computertomographie (CT) vorzuziehen. Konventionelle Röntgenbilder sind das primäre Verfahren zur Abklärung des Thorax und Skeletts. Der Einsatz der CT sollte möglichst auf die weitergehende Abklärung von Veränderungen der Luftwege und Lungen sowie die Notfallsituation eines Schädel-Hirn- oder Polytraumas beschränkt sein. Jede Untersuchung mit ionisierenden Strahlen bedarf einer rechtfertigenden medizinischen Indikation. Röntgenuntersuchungen, Durchleuchtungen und CT erfordern optimierte Geräte mit speziellen Kinderprotokollen, um eine minimale Strahlenbelastung zu gewährleisten.
Separating bathymetric data representing multiscale rhythmic bed forms: A geostatistical and spectral method compared
Authors: van Dijk Thaiënne A. G. P. , Lindenbergh Roderik C. , Egberts Paul J. P.
Published: December 2008

The superimposition of rhythmic bed forms of different spatial scales is a common and natural phenomenon on sandy seabeds. The dynamics of such seabeds may interfere with different offshore activities and are therefore of interest to both scientists and offshore developers. State‐of‐the‐art echo sounding accuracy allows for the analysis of bed form dynamics on unprecedented spatial and temporal scales. However, the superimposition of bed forms complicates the automated determination of morphodynamic parameters of individual bed form components. In this research we present the extension and comparison of two well‐known, automated signal‐processing methods for the 1‐D and 2‐D separation of bathymetric data derived from multibeam echo soundings into different components that each represents a bed form of a particular length scale. One method uses geostatistical filtering, and the other uses a Fourier decomposition of the bathymetric data. The application of both methods in two case studies of the North Sea shows that both methods are successful and that results correspond well. For example, megaripples up to 0.83 m height could be separated from 1.49–2.28 m high sand waves, and regionally averaged lengths and heights of sand waves, as calculated in either method, differ only 0.42–8.2% between methods. The obtained sand wave migration rates differ 7–11% between methods. The resulting morphometric and morphodynamic bed form quantification contributes to studies of empirical behavior and morphodynamic model validation and is valuable in risk assessments of offshore human activities.
Controls on the spacing of first‐order valleys
Authors: Perron J. Taylor , Dietrich William E. , Kirchner James W.
Published: December 2008

Many landscapes are composed of ridges and valleys that are uniformly spaced, even where valley locations are not controlled by bedrock structure. Models of long‐term landscape evolution have reproduced this phenomenon, yet the process by which uniformly spaced valleys develop is not well understood, and there is no quantitative framework for predicting valley spacing. Here we use a numerical landscape evolution model to investigate the development of uniform valley spacing. We find that evenly spaced valleys arise from a competition between adjacent drainage basins for drainage area (a proxy for water flux) and that the spacing becomes more uniform as the landscape approaches a topographic equilibrium. Valley spacing is most sensitive to the relative rates of advective erosion processes (such as stream incision) and diffusion‐like mass transport (such as soil creep) and less sensitive to the magnitude of a threshold that limits the spatial extent of stream incision. Analysis of a large number of numerical solutions reveals that valley spacing scales with a ratio of characteristic diffusion and advection timescales that is analogous to a Péclet number. We use this result to derive expressions for equilibrium valley spacing and drainage basin relief as a function of the rates of advective and diffusive processes and the spatial extent of the landscape. The observed scaling relationships also provide insight into the cause of transitions from rill‐like drainage networks to branching networks, the spatial scale of first‐order drainage basins, the contributing area at which hillslopes transition into valleys, and the narrow range of width‐to‐length ratios of first‐order basins.
Assessing the representativeness of the AmeriFlux network using MODIS and GOES data
Authors: Yang Feihua , Zhu A‐Xing , Ichii Kazuhito , White Michael A. , Hashimoto Hirofumi , Nemani Ramakrishna R.
Published: December 2008

The AmeriFlux network of eddy covariance towers has played a critical role in the analysis of terrestrial water and carbon dynamics. It has been used to understand the general principles of ecosystem behaviors and to scale up those principles from sites to regions. To support the generalization from individual sites to large regions, it is essential that all major ecoregions in North America are represented in the AmeriFlux network. In this study, we examined the representativeness of the AmeriFlux network by comparing the climate and vegetation across the coterminous United States in 2004 with those at the AmeriFlux network in 2000–2004 on the basis of remote sensing products. We found that the AmeriFlux network generally captured the climatic and vegetation characteristics in the coterminous United States with under‐representations in the Rocky Mountain evergreen needleleaf forest, the Sierra Nevada Mountains, the Sonora desert, the northern Great Plains, the Great Basin Desert, and New England. In terms of site representativeness, our analysis suggested that Indiana Morgan Monroe State Forest, Indiana, and Harvard Forest, Massachusetts, were among the forest sites with high representativeness extents; while Audubon Research Ranch, Arizona, and Sky Oaks Young Chaparral were among the nonforest sites with high representativeness extents.
Geochemical and microbiological fingerprinting of airborne dust that fell in Canberra, Australia, in October 2002
Authors: De Deckker Patrick , Abed Raeid M. M. , de Beer Dirk , Hinrichs Kai‐Uwe , O'Loingsigh Tadhg , Schefuß Enno , Stuut Jan‐Berend W. , Tapper Nigel J. , van der Kaars Sander
Published: December 2008

During the night of 22–23 October 2002, a large amount of airborne dust fell with rain over Canberra, located some 200 km from Australia's east coast, and at an average altitude of 650 m. It is estimated that during that night about 6 g m−2 of aeolian dust fell. We have conducted a vast number of analyses to “fingerprint” some of the dust and used the following techniques: grain size analysis; scanning electron microscope imagery; major, trace, and rare earth elemental, plus Sr and Nd isotopic analyses; organic compound analyses with respective compound‐specific isotope analyses; pollen extraction to identify the vegetation sources; and molecular cloning of 16S rRNA genes in order to identify dust bacterial composition. DNA analyses show that most obtained 16S rRNA sequences belong mainly to three groups: Proteobacteria (25%), Bacteriodetes (23%), and gram‐positive bacteria (23%). In addition, we investigated the meteorological conditions that led to the dust mobilization and transport using model and satellite data. Grain sizes of the mineral dust show a bimodal distribution typical of proximal dust, rather than what is found over oceans, and the bimodal aspect of size distribution confirms wet deposition by rain droplets. The inorganic geochemistry points to a source along/near the Darling River in NW New South Wales, a region that is characteristically semiarid, and both the organic chemistry and palynoflora of the dust confirm the location of this source area. Meteorological reconstructions of the event again clearly identify the area near Bourke‐Cobar as being the source of the dust. This study paves the way for determining the export of Australian airborne dust both in the oceans and other continents.
A survey of methane isotope abundance (14C, 13C, 2H) from five nearshore marine basins that reveals unusual radiocarbon levels in subsurface waters
Authors: Kessler J. D. , Reeburgh W. S. , Valentine D. L. , Kinnaman F. S. , Peltzer E. T. , Brewer P. G. , Southon J. , Tyler S. C.
Published: December 2008

Methane (CH4) in the subsurface ocean is often supersaturated compared to equilibrium with the modern atmosphere. In order to investigate sources of CH4 to the subsurface ocean, isotope surveys (14C‐CH4,δ13C‐CH4, δ2H‐CH4) were conducted at five locations: Skan Bay (SB), Santa Barbara Basin (SBB), Santa Monica Basin (SMB), Cariaco Basin (CB), and the Guaymas Basin (GB). Depth distributions of CH4 concentration and isotopic abundance were determined for both the sediment and water column at the SB, SBB, SMB, and CB sites; CH4 emitted from seeps on the continental shelf adjacent to the SBB as well as seeps and decomposing clathrate hydrates in the GB was also collected, purified, and analyzed. Methane isotope distributions in the sediments were consistent with known methanogenic and methanotrophic activity; seep‐ and clathrate‐hydrate‐derived CH4 was found to be depleted in radiocarbon. However, surprising results were obtained in the water column at all sites investigated. In SB the radiocarbon content of the subsurface CH4 concentration maximum was on average 41% less than its suspected sediment CH4 source, suggesting CH4 seepage in the bay. In the SBB, SMB, and CB, the 14C‐CH4 contents in the subsurface ocean were 1.2 to 3.6 times greater than modern carbon quantities suggesting a source of 14C from atmospheric nuclear weapons testing, nuclear power plant effluents, or cosmogenic isotope production.
Dynamic response of oceanic hydrate deposits to ocean temperature change
Authors: Reagan Matthew T. , Moridis George J.
Published: December 2008

Vast quantities of methane are trapped in oceanic hydrate deposits. Because methane is a powerful greenhouse gas (about 26 times more effective than CO2), there is considerable concern that a rise in the temperature of the oceans will induce dissociation of oceanic hydrate accumulations, potentially releasing large amounts of carbon into the atmosphere. Such a release could have dramatic climatic consequences because it could amplify atmospheric and oceanic warming and possibly accelerate dissociation of the remaining hydrates. This study assesses the stability of three types of hydrates (case I, deep‐ocean deposits; case II, shallow, warm deposits; and case III, shallow, cold deposits) and simulates the dynamic behavior of these deposits under the influence of moderate ocean temperature increases. The results indicate that deep‐ocean hydrates are stable under the influence of moderate increases in ocean temperature; however, shallow deposits can be very unstable and release significant quantities of methane under the influence of as little as 1°C of seafloor temperature increase. Less permeable sediments, or burial underneath layers of hydrate‐free sediment, affect both the rate of hydrate dissociation and methane transport to the seafloor but may not prevent methane release. Higher‐saturation deposits can produce larger methane fluxes with the thermodynamics of hydrate dissociation retarding the rate of recession of the upper hydrate interface. These results suggest possible worst case scenarios for climate‐change‐induced methane release and point toward the need for detailed assessment of the hydrate hazard and the coupling of hydrate‐derived methane to regional and global ecosystems.
Ice water content of Arctic, midlatitude, and tropical cirrus
Authors: Schiller C. , Krämer M. , Afchine A. , Spelten N. , Sitnikov N.
Published: December 2008

In situ measurements of total water have been obtained during several airborne field experiments in the Arctic (POLSTAR 1997 and 1998; EUPLEX/ENVISAT 2003), at midlatitudes (ENVISAT 2002, Cirrus 2003 and 2004, TROCCINOX 2005), and in the tropics (APE‐THESEO 1999, TROCCINOX/ENVISAT 2005, SCOUT‐O3 2005) in 52 flights in cirrus using the Jülich Lyman‐α fluorescence hygrometer FISH. For a subset of 28 flights, the measurements are complemented by gas phase measurements of H2O. From the data set obtained in these experiments, the ice water content (IWC) in cirrus clouds is derived using two different approaches and functions of the minimum, mean, median, and maximum IWC are provided. The data are analyzed as a function of temperature in the range 183–250 K for Arctic, midlatitudinal, and tropical regions thus extending previous climatologies to much lower temperatures and lower detectable IWC. For each temperature, IWC covers a broad band, decreasing with temperature over the whole temperature range. In the tropics, several events of enhanced ice water content are observed which are related to recent impact of convection.
Importance of molecular Rayleigh scattering in the enhancement of clear sky reflectance in the vicinity of boundary layer cumulus clouds
Authors: Wen Guoyong , Marshak Alexander , Cahalan Robert F.
Published: December 2008

Clouds increase the complexity of atmospheric radiative transfer processes, particularly for aerosol retrievals in clear regions in the vicinity of clouds. This study focuses on identifying mechanisms responsible for the enhancement of nadir reflectance in clear regions in the vicinity of cumulus clouds and quantifies the relative importance of each mechanism. Using cloud optical properties and surface albedo derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Moderate Resolution Imaging Spectroradiometer (MODIS), we performed extensive Monte Carlo simulations of radiative transfer in two cumulus scenes in a biomass burning region in Brazil. The results show that the scattering of radiation by clouds, followed by upward Rayleigh scattering by molecules above cloud top over clear gaps, is the dominant mechanism for the enhancement of visible reflectance in clear regions in boundary layer cumulus field over dark surfaces with aerosols trapped in the boundary layer. The Rayleigh scattering contributes ∼80% and ∼50% to the total enhancement for wavelengths 0.47 μm (with aerosol optical thickness 0.2) and 0.66 μm (with aerosol optical thickness 0.1), respectively. Out of the total contribution of molecular scattering, ∼90% arises from the clear atmosphere above cloud top height. The mechanism is valid for a large range of aerosol optical thicknesses (up to 1 in this study) for 0.47 μm, and for aerosol optical thickness up to 0.2 for 0.66 μm. Our results provide a basis to develop simplifications for future aerosol remote sensing from satellite.
Exploring the error characteristics of thin ice cloud property retrievals using a Markov chain Monte Carlo algorithm
Authors: Posselt D. J. , L'Ecuyer T. S. , Stephens G. L.
Published: December 2008

It is commonly assumed that ice cloud property retrievals are well‐constrained so that a look‐up table or an optimal estimation approach can be used to provide a unique solution. However, because of nonlinearities in radiative transfer models, error characteristics of retrieved ice cloud properties are generally not well‐known. The Markov chain Monte Carlo (MCMC) approach, which represents information from prior knowledge, observations, and the forward model probabilistically, allows for an accurate assessment of the solution space and the nature of uncertainties in the retrieval. In this paper, an MCMC algorithm is used to examine the sensitivity of infrared split window retrieved ice water path and ice particle effective radius to changes in cloud top height, cloud geometric thickness, and the assumed ice crystal shape. In addition, we assess the effect of particle settling, changes to observation error magnitude, and the implementation of a log‐normal error distribution on the retrieval results. It is found that, though the effects of uncertainty in cloud top height are not insignificant, uncertainty in the ice crystal shape contributes most to the uncertainty in the retrieval and gives rise to the potential for multiple solutions. Reduction of observation error and the assumption of particle settling serve to change the preferred combination of crystal shapes in the volume but do not eliminate the potential for a multimodal result. Application of the MCMC algorithm to a scene reveals that both the nature and magnitude of retrieval errors exhibit a strong dependence on cloud optical depth.
Basinal restriction, black shales, Re‐Os dating, and the Early Toarcian (Jurassic) oceanic anoxic event
Authors: McArthur J. M. , Algeo T. J. , van de Schootbrugge B. , Li Q. , Howarth R. J.
Published: December 2008

Profiles of Mo/total organic carbon (TOC) through the Lower Toarcian black shales of the Cleveland Basin, Yorkshire, United Kingdom, and the Posidonia shale of Germany and Switzerland reveal water mass restriction during the interval from late tenuicostatum Zone times to early bifrons Zone times, times which include that of the putative Early Toarcian oceanic anoxic event. The degree of restriction is revealed by crossplots of Mo and TOC concentrations for the Cleveland Basin, which define two linear arrays with regression slopes (ppm/%) of 0.5 and 17. The slope of 0.5 applies to sediment from the upper semicelatum and exaratum Subzones. This value, which is one tenth of that for modern sediments from the Black Sea (Mo/TOC regression slope 4.5), reveals that water mass restriction during this interval was around 10 times more severe than in the modern Black Sea; the renewal frequency of the water mass was between 4 and 40 ka. The Mo/TOC regression slope of 17 applies to the overlying falciferum and commune subzones: the value shows that restriction in this interval was less severe and that the renewal frequency of the water mass was between 10 and 130 years. The more restricted of the two intervals has been termed the Early Toarcian oceanic anoxic event but is shown to be an event caused by basin restriction local to NW Europe. Crossplots of Re, Os, and Mo against TOC show similar trends of increasing element concentration with increase in TOC but with differing slopes. Together with modeling of 187Os/188Os and δ98Mo, the element/TOC trends show that drawdown of Re, Os, and Mo was essentially complete during upper semicelatum and exaratum Subzone times (Mo/TOC regression slope of 0.5). Drawdown sensitized the restricted water mass to isotopic change forced by freshwater mixing so that continental inputs of Re, Os, and Mo, via a low‐salinity surface layer, created isotopic excursions of up to 1.3‰ in δ98Mo and up to 0.6‰ for 187Os/188Os. Restriction thereby compromises attempts to date Toarcian black shales, and possibly all black shales, using Re‐Os chronology and introduces a confounding influence in the attempts to use δ98Mo and initial 187Os/188Os for palaeo‐oceanographic interpretation.
Paleogene building of the Bolivian Orocline: Tectonic restoration of the central Andes in 2‐D map view
Authors: Arriagada C. , Roperch P. , Mpodozis C. , Cobbold P. R.
Published: December 2008

Using available information on the magnitude and age of tectonic shortening, as well as paleomagnetically determined tectonic rotations, we have run a series of 2‐D map view restorations of the central Andes. Neogene shortening in the foreland belt induced only slight orogenic curvature of the central Andes. The constraints on the ages of the large observed fore‐arc rotations (average of 37° counterclockwise in southern Peru and 29° clockwise in northern Chile) indicate that the Bolivian Orocline formed during the Eocene‐Oligocene as a consequence of differential shortening focused in the Eastern Cordillera. To minimize local block rotations along the fore arc, the restoration that best fits the central Andean rotation pattern requires about 400 km of total (Paleogene plus Neogene) shortening near the Arica bend. This value corresponds to the upper bound of estimates of maximum horizontal shortening for the central Andes. Along‐strike variations in horizontal shortening in the back arc induced bending of the continental margin, block rotations with fore‐arc along‐strike extension, and/or orogen‐parallel transport of upper crustal material toward the symmetry axis of the orocline.
Mycobacterium tuberculosis infection of human monocyte‐derived macrophages leads to apoptosis of T cells
Authors: Sharma Sadhna , Sharma Monika , Bose Mridula
Published: December 2008

The induction of apoptosis of T cells by intracellular pathogen is an attractive hypothesis to explain their persistence in host cells. To test this hypothesis, human monocyte‐derived macrophages were infected with Mycobacterium tuberculosis H37Rv and cocultured with autologous T cells stimulated with nonspecific phytohemagglutinin (PHA) or specific culture filtrate protein (CFP) of M. tuberculosis. CD95 (Fas) expression, propidium iodide (PI) staining and terminal deoxy nucleotidyl transferase (TdT)‐mediated dUTP nick end labeling (TUNEL) assay of CD3 cells were studied to assess the viability. Apoptotic cells were correlated with the levels of nitric oxide (NO) and tumor necrosis factor‐α (TNF‐α). An increased CD3/PI and CD3/CD95+ PHA‐preactivated T cells in coculture with M. tuberculosis‐infected macrophages suggested Fas–Fas ligand interactions to be important in apoptosis of nonspecifically stimulated T cells. Significantly higher NO and TNF‐ α levels suggested an association of the soluble factors with apoptosis of nonspecifically activated T cells. Significantly high release of TNF‐α in the coculture of infected macrophages with CFP‐activated T cells pointed toward its association with specific T‐cell apoptosis. We show for the first time that in vitro infection of human macrophages with M. tuberculosis induces apoptosis of specific and to a much greater extent of nonspecific T cells.
Type II‐activated macrophages suppress the development of experimental autoimmune encephalomyelitis
Authors: Tierney Joanna B , Kharkrang Marie , La Flamme Anne Camille
Published: December 2008

Treatment with immune complexes, which ligate Fcγ receptors (FcγRs), suppresses the development of experimental autoimmune encephalomyelitis (EAE). To determine the mechanism of action, we investigated how these immune complexes affected type II activation of macrophages (that is, exposure to immune complexes in a proinflammatory environment). Our results show that lower doses of interferon‐γ (IFN‐γ) were more effective at priming bone marrow‐derived macrophages (BMMφ) to produce more interleukin 10 (IL‐10) and less IL‐12p40 in response to lipopolysaccharide (LPS) and immune complexes compared with LPS alone. Moreover, at the lowest level of IFN‐γ (20 U ml−1), a significant downregulation in the surface expression of CD40, CD80 and PD‐L1 was observed in LPS and immune complex‐stimulated macrophages (that is, type II activated) than macrophages stimulated with LPS alone (that is, classically activated). Finally, treatment of mice with type II‐activated macrophages protected them from developing EAE, suggesting that administration of immune complexes is protective against EAE by inducing type II‐activated macrophages.
Characterization of key residues and membrane association domains in retinol dehydrogenase 10
Authors: Takahashi Yusuke , Moiseyev Gennadiy , Farjo Krysten , Ma Jian-xing
Published: December 2008

RDH10 (retinol dehydrogenase 10) was originally identified from the retinal pigment epithelium and retinal Müller cells. It has retinoid oxidoreductase activity and is thought to play a role in the retinoid visual cycle. A recent study showed that RDH10 is essential for generating retinoic acid at early embryonic stages. The present study demonstrated that wild-type RDH10 catalysed both oxidation of all-trans-retinol and reduction of all-trans-retinal in a cofactor-dependent manner In vitro. In cultured cells, however, oxidation is the favoured reaction catalysed by RDH10. Substitution of any of the predicted key residues in the catalytic centre conserved in the RDH family abolished the enzymatic activity of RDH10 without affecting its protein level. Unlike other RDH members, however, replacement of Ser197, a key residue for stabilizing the substrate, by glycine and alanine did not abolish the enzymatic activity of RDH10, whereas RDH10 mutants S197C, S197T and S197V completely lost their enzymatic activity. These results suggest that the size of the residue at position 197 is critical for the activity of RDH10. Mutations of the three glycine residues (Gly43, Gly47 and Gly49) in the predicted cofactor-binding motif (Gly-Xaa3-Gly-Xaa-Gly) of RDH10 abolished its enzymatic activity, suggesting that the cofactor-binding motif is essential for its activity. Deletion of the two hydrophobic domains dissociated RDH10 from the membrane and abolished its activity. These studies identified the key residues for the activity of RDH10 and will contribute to the further elucidation of mechanism of this important enzyme.
Single-Myb-histone proteins from Arabidopsis thaliana: a quantitative study of telomere-binding specificity and kinetics
Authors: Hofr Ctirad , Šultesová Pavla , Zimmermann Michal , Mozgová Iva , Procházková Schrumpfová Petra , Wimmerová Michaela , Fajkus Jiří
Published: December 2008

Proteins that bind telomeric DNA modulate the structure of chromosome ends and control telomere function and maintenance. It has been shown that AtTRB (Arabidopsis thaliana telomere-repeat-binding factor) proteins from the SMH (single-Myb-histone) family selectively bind double-stranded telomeric DNA and interact with the telomeric protein AtPOT1b (A. thaliana protection of telomeres 1b), which is involved in telomere capping. In the present study, we performed the first quantitative DNA-binding study of this plant-specific family of proteins. Interactions of full-length proteins AtTRB1 and AtTRB3 with telomeric DNA were analysed by electrophoretic mobility-shift assay, fluorescence anisotropy and surface plasmon resonance to reveal their binding stoichiometry and kinetics. Kinetic analyses at different salt conditions enabled us to estimate the electrostatic component of binding and explain different affinities of the two proteins to telomeric DNA. On the basis of available data, a putative model explaining the binding stoichiometry and the protein arrangement on telomeric DNA is presented.
Arginine, citrulline and nitric oxide metabolism in sepsis
Authors: Kao Christina C. , Bandi Venkata , Guntupalli Kalpalatha K. , Wu Manhong , Castillo Leticia , Jahoor Farook
Published: December 2008

Arginine has vasodilatory effects, via its conversion by NO synthase into NO, and immunomodulatory actions which play important roles in sepsis. Protein breakdown affects arginine availability and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore affect NO synthesis in patients with sepsis. The objective of the present study was to investigate whole-body in vivo arginine and citrulline metabolism and NO synthesis rates, and their relationship to protein breakdown in patients with sepsis or septic shock and in healthy volunteers. Endogenous leucine flux, an index of whole-body protein breakdown rate, was measured in 13 critically ill patients with sepsis or septic shock and seven healthy controls using an intravenous infusion of [1-13C]leucine. Arginine flux, citrulline flux and the rate of conversion of arginine into citrulline (an index of NO synthesis) were measured with intravenous infusions of [15N2]guanidino-arginine and [5,5-2H2]citrulline. Plasma concentrations of nitrite plus nitrate, arginine, citrulline and asymmetric dimethylarginine were measured. Compared with controls, patients had a higher leucine flux and higher NO metabolites, but arginine flux, plasma asymmetric dimethylarginine concentration and the rate of NO synthesis were not different. Citrulline flux and plasma arginine and citrulline were lower in patients than in controls. Arginine production was positively correlated with the protein breakdown rate. Whole-body arginine production and NO synthesis were similar in patients with sepsis and septic shock and healthy controls. Despite increased proteolysis in sepsis, there is a decreased arginine plasma concentration, suggesting inadequate de novo synthesis secondary to decreased citrulline production.
Visual Data Mining in Spatial Interaction Analysis with Self-Organizing Maps
Authors: Yan Jun , Thill Jean-Claude
Published: December 2008

Given that many spatial interaction (SI) systems are often constituted in large databases with high thematic dimensionality, data complexity reduction tasks are essential. The opportunity exists for researchers to examine the formation of different types of SIs as well as their interdependencies by exploring the patterns embedded in the data. To circumvent the limitations of existing methods of flow data compression and visual exploration, we propose an integrated computational and visual approach, known as VISIDAMIN, for handling both SI data projection and SI data quantization at once. The computational method of self-organizing maps serves as the data mining engine in this process. Using a large domestic air travel dataset as a case study, we examine how the characteristics of the air transport system interact with the SI system to create relationships and structures within the US domestic airline market.
An Approach to Land-Use and Transportation Planning That Facilitates City and Region Cooperation
Authors: Lowry Michael B , Balling Richard J
Published: December 2008

This paper presents a new approach to land-use planning and transportation planning that provides regional planners with a means to achieve their goals without infringing upon local autonomy. The approach focuses on facilitating cooperation between city and regional planners. This is accomplished through two sequential stages: (1) the regional-planning stage and (2) the city-planning stage. In both stages, land-use planning and transportation planning are cast as multiobjective design problems and solved with a genetic algorithm. An example of the approach is presented using data for a medium-sized metropolitan region and a city within it.
Linking Planning Theories with Factors Influencing Local Environmental-Plan Quality
Authors: Tang Zhenghong , Brody Samuel D
Published: December 2008

The major planning theories provide a theoretical foundation for environmental planning. This study extends the major planning theories and develops a robust conceptual framework to measure the key factors influencing local environmental-plan quality. A random sample of forty Californian local comprehensive land-use plans and associated planning processes is analyzed to identify the critical factors influencing environmental-plan quality. Results from multiple regression analysis indicate that regular updating, environmental-information management and sharing, and planners contribute significantly to local environmental-plan quality. The findings expand established planning theories and practice by suggesting ways to improve local environmental-plan quality.
Target Visibility in the Standing Wave Illusion: Is Mask—Target Shape Similarity Important?
Authors: Pilling Michael , Gellatly Angus
Published: December 2008

The perceptibility of a flickering central bar can be dramatically reduced by the presence of two flanking bars presented in counterphase. This phenomenon, known as the ‘standing wave illusion’, has been suggested to involve local edge interactions (Macknik et al, 2000 Proceedings of the National Academy of Sciences of the USA97 7556–7560). High-level re-entrant mechanisms have also been implicated. Enns (2002, Psychonomic Bulletin & Review9 489–496) reports an association between the reported viability of the centre bar and its similarity in shape with the flanking bars. We find that this relationship between shape similarity and reported visibility seems to be contingent on the degree of experienced apparent motion. When target duration is shortened, so reducing apparent motion, reports of visibility reflect the amount of abutting contour. In a further experiment we find that luminance discriminations of the centre bar are related to the amount of abutting contour not to shape similarity. This is despite experiment 3 being conducted at stimulus durations for which experiment 2 visibility ratings indicated that shape similarity is important and contour is not. We suggest that this perceived motion may be the factor mediating shape ‘effects’ in the reported visibility task. We propose that the absence of such shape effects in the discrimination task may be because the task provides an objective measure of visibility that is immune to bias from perceived motion. We also speculate that while target luminance information may be immune to masking resulting from perceived motion, it may be subject to masking due to lateral inhibition.
View-Contingent Aftereffects Suggest Joint Coding of Face Shape and View
Authors: Welling Lisa L M , Jones Benedict C , Bestelmeyer Patricia E G , DeBruine Lisa M , Little Anthony C , Conway Claire A
Published: December 2008

While it is well established that different neural populations code different face views, behavioural evidence that these neurons also code other aspects of face shape is equivocal. For example, previous studies have interpreted the partial transfer of face aftereffects across different viewpoints as evidence for either view-specific coding of face shape or that the locus of adaptation is in face-coding mechanisms that are relatively robust to changes in face view. Here we show that it is possible to simultaneously induce aftereffects in opposite directions for 3/4 and front views of upright faces with manipulated mouth position (experiment 1). For example, simultaneous adaptation to 3/4 views with raised mouth position and front views with lowered mouth position caused raised mouth position to appear more normal for 3/4 views of novel faces, but less normal for front views. View-contingent adaptation did not occur for inverted faces, however (experiment 2). Dissociable aftereffects for different views of upright faces, but not for different views of inverted faces, suggest that neurons that code face view can also code other aspects of face shape.
Anticipated Effort in Imagined Self-Rotation
Authors: Macramalla Steven , Bridgeman Bruce
Published: December 2008

Chronometric studies provide strong support that mental imagery recruits perceptual processes [Shepard and Cooper, 1982 Mental Images and Their Transformations (Cambridge, MA: MIT Press)]. Recent studies suggest that anticipated effort influences perception (Proffitt et al, 2003 Psychological Science14 106–112). If anticipated effort influences perception and perception supports imagery, then anticipated effort may influence imagery. To examine the role of effort in mental imagery, participants in experiment 1 imagined self-rotation across two conditions of distance. Simulated rotation took 156 ms longer in larger settings, even though the amount of imagined angular rotation was the same in both settings. This finding suggests the start-to-goal arc is incorporated when imagining rotation through a given angle. Experiment 2 replicated the distance effect (232 ms) and added a variable for load. Simulated rotation took 167 ms longer with imaginary heavy loads. The results suggest that both spatial metrics and anticipated effort may play a role in the coding of mental imagery.
Topological structures in the equities market network
Authors: Leibon Gregory , Pauls Scott , Rockmore Daniel , Savell Robert
Published: December 2008

We present a new method for articulating scale-dependent topological descriptions of the network structure inherent in many complex systems. The technique is based on “partition decoupled null models,” a new class of null models that incorporate the interaction of clustered partitions into a random model and generalize the Gaussian ensemble. As an application, we analyze a correlation matrix derived from 4 years of close prices of equities in the New York Stock Exchange (NYSE) and National Association of Securities Dealers Automated Quotation (NASDAQ). In this example, we expose (i) a natural structure composed of 2 interacting partitions of the market that both agrees with and generalizes standard notions of scale (e.g., sector and industry) and (ii) structure in the first partition that is a topological manifestation of a well-known pattern of capital flow called “sector rotation.” Our approach gives rise to a natural form of multiresolution analysis of the underlying time series that naturally decomposes the basic data in terms of the effects of the different scales at which it clusters. We support our conclusions and show the robustness of the technique with a successful analysis on a simulated network with an embedded topological structure. The equities market is a prototypical complex system, and we expect that our approach will be of use in understanding a broad class of complex systems in which correlation structures are resident.
Targeting Nrf2 with the triterpenoid CDDO- imidazolide attenuates cigarette smoke-induced emphysema and cardiac dysfunction in mice
Authors: Sussan Thomas E. , Rangasamy Tirumalai , Blake David J. , Malhotra Deepti , El-Haddad Hazim , Bedja Djahida , Yates Melinda S. , Kombairaju Ponvijay , Yamamoto Masayuki , Liby Karen T. , Sporn Michael B. , Gabrielson Kathleen L. , Champion Hunter C. , Tuder Rubin M. , Kensler Thomas W. , Biswal Shyam
Published: December 2008

Chronic obstructive pulmonary disease (COPD), which comprises emphysema and chronic bronchitis resulting from prolonged exposure to cigarette smoke (CS), is a major public health burden with no effective treatment. Emphysema is also associated with pulmonary hypertension, which can progress to right ventricular failure, an important cause of morbidity and mortality among patients with COPD. Nuclear erythroid 2 p45 related factor-2 (Nrf2) is a redox-sensitive transcription factor that up-regulates a battery of antioxidative genes and cytoprotective enzymes that constitute the defense against oxidative stress. Recently, it has been shown that patients with advanced COPD have a decline in expression of the Nrf2 pathway in lungs, suggesting that loss of this antioxidative protective response is a key factor in the pathophysiological progression of emphysema. Furthermore, genetic disruption of Nrf2 in mice causes early-onset and severe emphysema. The present study evaluated whether the strategy of activation of Nrf2 and its downstream network of cytoprotective genes with a small molecule would attenuate CS-induced oxidative stress and emphysema.
Nrf2
+/+
and
Nrf2
−/−
mice were fed a diet containing the potent Nrf2 activator, 1-[2-cyano-3-,12-dioxooleana-1,9(
11
)-dien-28-oyl]imidazole (CDDO-Im), while being exposed to CS for 6 months. CDDO-Im significantly reduced lung oxidative stress, alveolar cell apoptosis, alveolar destruction, and pulmonary hypertension in
Nrf2
+/+
mice caused by chronic exposure to CS. This protection from CS-induced emphysema depended on Nrf2, as
Nrf2
−/−
mice failed to show significant reduction in alveolar cell apoptosis and alveolar destruction after treatment with CDDO-Im. These results suggest that targeting the Nrf2 pathway during the etiopathogenesis of emphysema may represent an important approach for prophylaxis against COPD.
Filament rigidity causes F-actin depletion from nonbinding surfaces
Authors: Fisher Charles I. , Kuo Scot C.
Published: December 2008

Proximity to membranes is required of actin networks for many key cell functions, including mechanics and motility. However, F-actin rigidity should hinder a filament's approach to surfaces. Using confocal microscopy, we monitor the distribution of fluorescent actin near nonadherent glass surfaces. Initially uniform, monomers polymerize to create a depletion zone where F-actin is absent at the surface but increases monotonically with distance from the surface. At its largest, depletion effects can extend >35 μm, comparable with the average, mass-weighted filament length. Increasing the rigidity of actin filaments with phalloidin increases the extent of depletion, whereas shortening filaments by using capping protein reduces it proportionally. In addition, depletion kinetics are faster with higher actin concentrations, consistent with faster polymerization and faster Brownian-ratchet-driven motion. Conversely, the extent of depletion decreases with actin concentration, suggesting that entropy is the thermodynamic driving force. Quantitatively, depletion kinetics and extent match existing actin kinetics, rigidity, and lengths. However, explaining depletion profiles and concentration dependence (power-law of −1) requires modifying the rigid rod model. Within cells, surface depletion should slow membrane-associated F-actin reactions another ≈10-fold beyond hydrodynamically slowed diffusion of filaments (≈10-fold). In addition, surface depletion should cause membranes to bend spontaneously toward filaments. Such depletion principles underlie the thermodynamics of all surface-associated reactions with mechanical structures, ranging from DNA to filaments to networks. For various functions, cells must actively resist the thermodynamics of depletion.
Explosively launched spores of ascomycete fungi have drag-minimizing shapes
Authors: Roper Marcus , Pepper Rachel E. , Brenner Michael P. , Pringle Anne
Published: December 2008

The forcibly launched spores of ascomycete fungi must eject through several millimeters of nearly still air surrounding fruiting bodies to reach dispersive air flows. Because of their microscopic size, spores experience great fluid drag, and although this drag can aid transport by slowing sedimentation out of dispersive air flows, it also causes spores to decelerate rapidly after launch. We hypothesize that spores are shaped to maximize their range in the nearly still air surrounding fruiting bodies. To test this hypothesis we numerically calculate optimal spore shapes—shapes of minimum drag for prescribed volumes—and compare these shapes with real spore shapes taken from a phylogeny of >100 species. Our analysis shows that spores are constrained to remain within 1% of the minimum possible drag for their size. From the spore shapes we predict the speed of spore launch, and confirm this prediction through high-speed imaging of ejection in
Neurospora tetrasperma
. By reconstructing the evolutionary history of spore shapes within a single ascomycete family we measure the relative contributions of drag minimization and other shape determinants to spore shape evolution. Our study uses biomechanical optimization as an organizing principle for explaining shape in a mega-diverse group of species and provides a framework for future measurements of the forces of selection toward physical optima.