bluuebunny/crossref_metadata_2025 huggingface dataset:
Concomitant neurological and orthopaedic diseases in the presence of peripheral arterial disease: A prospective study
Authors: Heidrich  , Hermann
Published: June 2006

Background: The symptoms of peripheral arterial disease (PAD) can be masked by neurological or orthopaedic diseases with identical symptoms, which may result in faulty therapy decisions, if the diagnosis is solely based on the reported complaints and angiographic or duplex ultrasonographic findings. A prospective study was therefore performed to find out how often established PAD is accompanied by neurological or orthopaedic pictures that can blend into the PAD symptoms. Patients and methods: The examination was performed in 235 patients with PAD of Fontaine’s stages II to IV, 125 were women and 110 men; the mean age was 71 years (41 to 95 years). They were systematically examined for angiologic, neurological and orthopaedic diseases. Results: 44% of the patients enrolled in the study suffered from a neurological disease, 45% from an orthopaedic disease and 24.7% from both a neurological and an orthopaedic disease. The frequency of concomitant diseases depended on the stage of PAD. In Fontaine’s stage II, alterations due to arthrosis or arthritis were found in 12% of the patients, peripheral neuropathies in 14%, radiculoneuropathies in 16% and malpositions of the foot in 16%. In Fontaine’s stage III, arthrosis and arthritis were predominant at a percentage of 38.5%; peripheral neuropathies were diagnosed in 15.4% of the patients. Patients with Fontaine’s stage IV most often showed peripheral polyneuropathies at 42.1% and malpositions of the foot at 28.4%. Conclusions: Because of the frequency of neurological and orthopaedic pictures with identical symptoms, a differential diagnosis before the initiation of a PAD therapy is imperative.
Congenital vascular malformations: The persistence of marginal and embryonal veins
Authors: Weber  , Daffinger
Published: June 2006

Background: In about 18% of cases with conginental vascular malformations we find a perspective of an atypical truncular vein, located along the outside of the leg, frequently extended from the dorsal foot up to the bottom. In presence of a normally developed system of the deep collecting veins of the lower limb and within the pelvic outflow we are talking about a persisting marginal vein (MV). Hypoplasia or even aplasia of the main deep veins in contrary defines the persisting embryonal vein (EV). Already in childhood these truncular dysplastic veins tend to develop varicose enlargement, causing severe reflux of a huge volume of blood – even more when being associated with av-fistulas (46%). In consequence a rapidly growing chronic venous insufficiency will guide to additional injuries. Patients and results: We have analysed 97 patients showing a persisting MV (n: 92 ) within a total of 102 legs. A persistent embryonal vein (EV) was seen 10 times within this clientel. The persisting truncular veins, associated with phlebectasias and typical clinical symptoms have been examined in a diagnostic “step-by-step” procedure, mainly phlebographically (ascending leg phlebography and varicography), including direct venous blood pressure measurements (phlebodynamometry) and – if needed – by arteriography, showing av-shunting fistulae in 46% of cases. CT and MRI were consulted for the exact therapy planing (frequently initially offered as a non-invasive, however, inadequate key of diagnostic). Actually now these techniques cannot replace pre-operatively the angiographic imaging techniques. Conclusions: The analysis of clinical, morphologic and functional signs, guiding to a specific therapy-relevant classification of MV’s and EV’s will be presented. And a specific strategy of surgical repair, interventional treatment of av-fistulas and conservative compressive follow-up treatment attempting palliative recompensation of the diseased venous outflow will be discussed also.
European Ice Sheet Modelling Initiative (EISMINT) model intercomparison experiments with first‐order mechanics
Authors: Saito Fuyuki , Abe‐Ouchi Ayako , Blatter Heinz
Published: June 2006

The European Ice Sheet Modelling Initiative (EISMINT) intercomparison experiments with thermomechanical coupling are repeated with an ice sheet model that applies the first‐order approximation for computing the flow field. The experiments impose radially symmetric boundary conditions. Most of the previous results have shown the loss of implied radial symmetry, i.e., the formation of distinct, regularly spaced spokes of cold ice in the simulated basal temperatures. A similar result is also observed in the presented first‐order model results. The computed velocity components scatter widely along the marginal grid points. This indicates that the spokes may be triggered by the poor representation of the margin with a regular grid, where the steep gradients in the surface enhance the numerical errors. Additionally, the generally applied second‐order discretization scheme tends to decouple even and odd numbered grid points, thus leading to wavy solutions with a wavelength of two grid cells. These patterns strongly suggest that the loss in radial symmetry is a numerical artifact.
Last stage of the Japan Sea back‐arc opening deduced from the seismic velocity structure using wide‐angle data
Authors: Sato Takeshi , Takahashi Narumi , Miura Seiichi , Fujie Gou , Kang Dong‐Hyo , Kodaira Shuichi , Kaneda Yoshiyuki
Published: June 2006

The Japan Sea is one of the most well studied back‐arc basins in the northwestern Pacific. The seismic crustal model, however, has been inadequate to elucidate the detailed opening model of the Japan Sea. In 2002, to clarify the late stage of the formation style of the Japan Sea opening, a seismic experiment using 35 ocean bottom seismographs (OBSs), an air gun array, and a multichannel hydrophone streamer was undertaken in the areas from the southwestern Yamato Basin, the Oki Ridge, and the southwestern Oki Trough to the coast of the southwestern Japan Island Arc. The crusts beneath the southwestern Yamato Basin and the Oki Ridge are estimated as having approximately 13 km and 19.5 km, respectively. The upper and lower crusts of the southwestern Yamato Basin are approximately 3.2 km and 8 km thick, respectively. Those of the Oki Ridge are approximately 8.2 km and 10.5 km thick, respectively. The upper crust of the Oki Ridge thickens more steeply than that of the southwestern Yamato Basin; however, the lower crust thickens more gently. The crustal structure of the southwestern Yamato Basin shows the extended continental crust accompanied with the opening of the Japan Sea. A remarkable structural characteristic, the upper crust being thinner than the lower crust, caused by listric or complicated normal faults developed in the upper crust of the southwestern Yamato Basin. This deformed upper crust is a common structural characteristic in the southern Japan Sea, which includes the Yamato Basin. The southern Yamato Basin, including the southwestern Yamato Basin, has the thinnest upper and lower crusts in the Japan Sea. For that reason, it is suggested that the southern Yamato Basin had the strongest deformation by a back‐arc opening and that the period of the opening in the southern Yamato Basin had been longest in the southern Japan Sea. The formation process of the southern Yamato Basin is inferred to have two stages: rifting and extension of continental crust separating the northeastern and southwestern Japan Island Arcs from the Asian continent and, further, the extension affected by the rotation of the southwestern Japan Island Arc.
Lithium isotopic composition of marine sediments
Authors: Chan Lui‐Heung , Leeman William P. , Plank Terry
Published: June 2006

To understand the role of subducted sediment in arc magmatism and the formation of the continental crust, we have determined the Li isotopic composition of marine sediments subducting at several trenches, as well as from nonconvergent margin settings. The bulk isotopic composition (δ7Li) of global sediments varies widely (from −4.3 to 14.5‰), reflecting sediment type, provenance, and diagenetic processes. Among detrital sediments (−1.5 to 5‰), clay‐rich variants are generally isotopically lighter than sands owing to isotopic fractionation during continental weathering. Sediments derived from mature continental crust are especially light. Volcanogenic sediments can have either heavier or lighter isotopic compositions than the mantle depending on alteration effects. Biogenic carbonate and silica are susceptible to recrystallization, which results in heavier isotopic compositions (6 to 14.5‰). The lightest composition was observed in hydrothermally leached sediments (−4.3‰). Slowly accumulated metalliferous sediments display anomalously high δ7Li (6 to 10‰) values due to incorporation of seawater‐derived Li. On the basis of this and previous studies, integrated δ7Li values for subducted sediment vary from arc to arc, ranging from −0.4 to 9‰. Calculated fluxes of subducted sediment‐derived Li also vary, from 1.4 to 18.2 g/yr per cm arc length. Although Li isotopic compositions of marine sediments largely overlap with those of the upper mantle and altered oceanic crust, controls on Li isotope composition of arc lavas are complex and must be understood in terms of the primary compositions and relative contributions of subducted sediments and oceanic crust, fractionation during metamorphic dehydration, and equilibration of slab‐derived fluids with the subarc mantle. Finally, although clay‐rich sediments can contribute to the light isotopic composition of continental crustal rocks, our results suggest diverse compositions of sedimentary rocks. Incorporation of sedimentary components in the formation of granitic rocks may give rise to greater heterogeneity in the composition of the upper continental crust than is currently estimated.
Ion cyclotron waves in Saturn's E ring: Initial Cassini observations
Authors: Leisner J. S. , Russell C. T. , Dougherty M. K. , Blanco‐Cano X. , Strangeway R. J. , Bertucci C.
Published: June 2006

The magnetometer onboard the Cassini spacecraft observes ion cyclotron waves produced by both water‐group (O+, OH+, H2O+, or H3O+) and O2+ ions at nearly all radial distances and local times within the E ring. These left‐hand elliptically polarized waves travel at small angles to the magnetic field and are restricted to near the equatorial plane, where they have their peak amplitudes. They are generated by pickup ions created by the ionization of the neutral exosphere surrounding the E‐ring material, and their subsequent acceleration by the electric field associated with the corotating plasma. The energy flux of these waves is proportional to the energy added to the ions when they are accelerated and enables an estimate of the rate of loss of the ring's exosphere.
Generation and life cycle of the dipole in the South China Sea summer circulation
Authors: Wang Guihua , Chen Dake , Su Jilan
Published: June 2006

The South China Sea (SCS) summer circulation often has a dipole structure associated with an eastward jet, appearing off central Vietnam. The dipole has an anticyclonic eddy (AE) south of the jet and a cyclonic eddy (CE) north of it. The life cycle of the dipole structure is analyzed using satellite altimetry data and a reduced gravity model. On average the dipole structure begins in June, peaks in strength in August or September, and disappears in October. The dipole evolution lags behind the basin scale wind by about 40 days, and 40 days are exactly what it takes for baroclinic planetary waves to cross the southern SCS. Our results show that the vorticity transports from the nonlinear effect of the western boundary currents are crucial for the generation of the dipole structure. In addition, the strength and direction of the offshore wind jet also play a significant role in determining the magnitudes and the core positions of the two concomitant eddies.
Measurements of ClONO2 by the Improved Limb Atmospheric Spectrometer (ILAS) in high‐latitude stratosphere: New products using version 6.1 data processing algorithm
Authors: Nakajima H. , Sugita T. , Irie H. , Saitoh N. , Kanzawa H. , Oelhaf H. , Wetzel G. , Toon G. C. , Sen B. , Blavier J.‐F. , Traub W. A. , Jucks K. , Johnson D. G. , Yokota T. , Sasano Y.
Published: June 2006

We report the first continuous measurements of chlorine nitrate (ClONO2) in high‐latitude regions taken by the Improved Limb Atmospheric Spectrometer (ILAS) on board the Advanced Earth Observing Satellite (ADEOS) and processed using the latest data retrieval algorithm (version 6.1). Performance of the measurements, validation with three balloon‐borne sensors, and seasonal variation of ClONO2 in the Arctic and Antarctic stratosphere are presented, as well as a brief description of the version 6.1 algorithm and data characteristics for both the Arctic and Antarctic. Although the ILAS‐measured ClONO2 data show, on average, ∼30% lower values than the validation data, they agree with validation data within the combined total error (∼20–40%) of the ClONO2 measurements at ∼15‐ to 32‐km altitudes. In the Arctic, enhancement of ClONO2 amounts was observed in spring 1997 after the appearance of polar stratospheric clouds (PSCs) inside the polar vortex. This is the result of preference for ClONO2 formation rather than HCl after the activation of ClOx in this Arctic spring of 1997. In the Antarctic, ClONO2 amounts showed strong local time/latitudinal dependence around the austral fall equinox in 1997.
Stratigraphic analysis of the distributary fan in Eberswalde crater using stereo imagery
Authors: Lewis Kevin W. , Aharonson Oded
Published: June 2006

The eroded remains of a fluvial distributary network in Eberswalde crater are uniquely well preserved among similar structures on Mars. A quantitative analysis of the exposed stratigraphy has been performed to investigate the internal structure of the deposit. Using topographic information derived from stereo pairs of high‐resolution Mars Orbiter Camera images, we have for the first time quantified the orientation of individual layers exposed along the distal end of the distributary network. In combination with topographic data from the Mars Orbiter Laser Altimeter, we have examined plausible scenarios for the formation of this structure. We find that the evidence is inconsistent with formation both as an alluvial fan and as a progradational delta. Instead, we find that an aggradational delta best fits the observed characteristics of the channel network and the Eberswalde basin as a whole. We conclude that the delta likely formed not in a stable long‐lived lake but over the course of a small number of shorter lacustrine episodes, which were not sustained at equilibrium conditions.
Effects of permafrost melting on CO2 and CH4 exchange of a poorly drained black spruce lowland
Authors: Wickland Kimberly P. , Striegl Robert G. , Neff Jason C. , Sachs Torsten
Published: June 2006

Permafrost melting is occurring in areas of the boreal forest region where large amounts of carbon (C) are stored in organic soils. We measured soil respiration, net CO2 flux, and net CH4 flux during May–September 2003 and March 2004 in a black spruce lowland in interior Alaska to better understand how permafrost thaw in poorly drained landscapes affects land‐atmosphere CO2 and CH4 exchange. Sites included peat soils underlain by permafrost at ∼0.4 m depth (permafrost plateau, PP), four thermokarst wetlands (TW) having no permafrost in the upper 2.2 m, and peat soils bordering the thermokarst wetlands having permafrost at ∼0.5 m depth (thermokarst edges, TE). Soil respiration rates were not significantly different among the sites, and 5‐cm soil temperature explained 50–91% of the seasonal variability in soil respiration within the sites. Groundcover vegetation photosynthesis (calculated as net CO2 minus soil respiration) was significantly different among the sites (TW > TE > PP), which can be partly attributed to the difference in photosynthetically active radiation reaching the ground at each site type. Methane emission rates were 15 to 28 times greater from TW than from TE and PP. We modeled annual soil respiration and groundcover vegetation photosynthesis using soil temperature and radiation data, and CH4 flux by linear interpolation. We estimated all sites as net C gas sources to the atmosphere (not including tree CO2 uptake at PP and TE), although the ranges in estimates when accounting for errors were large enough that TE and TW may have been net C sinks.
Oceanic processes as potential trigger and amplifying mechanisms for Heinrich events
Authors: Flückiger Jacqueline , Knutti Reto , White James W. C.
Published: June 2006

Marine sediments recorded a series of Heinrich events during the last glacial period, massive ice surges that deposited prominent layers of ice‐rafted debris in the North Atlantic. Here we explore oceanic mechanisms that can potentially trigger and amplify the observed ice calving events. Simulations of abrupt glacial climate change with a coupled ocean‐atmosphere‐sea ice model show a substantial regional sea level rise in the North Atlantic in response to a collapse of the Atlantic meridional overturning circulation (MOC). The increased heat uptake of the global ocean after the MOC collapse leads to an additional rise in global sea level. We hypothesize that these sea level changes have the potential to destabilize Northern Hemisphere ice shelves and ice sheets and to trigger ice surges. Sea level rise due to ice calving and subsurface ocean warming provides two positive feedback mechanisms contributing to further destabilization of ice shelves and ice sheets.
Efficient geostatistical inverse methods for structured and unstructured grids
Authors: Li Wei , Cirpka Olaf A.
Published: June 2006

The geostatistical inverse approach of Kitanidis (1995) requires the covariance matrix of a discretized spatial random variable and matrix multiplications of the covariance matrix. The explicit computation of the full covariance matrix is prohibitive for large‐scale problems. Discrete spectral methods, which help to reduce computational costs dramatically, are restricted to regular grids. To make the geostatistical inverse approach applicable to unstructured grids, which may be of great interest for practical applications, we use the functional parameterization of the spatial random field by the Karhunen‐Loève (KL) expansion, in which the spatial variable is parameterized by weighted base functions that are derived from the covariance function. In the inverse approach, the estimation of the spatial variable becomes estimating the weights of base functions. The prior covariance matrix of the weights is the identity matrix. The base functions are continuous in space and can be discretized in any fashion. For the derivation of the base functions, we embed the domain into a larger unit cell of a periodic domain. Then, the base functions are sinusoidal and can be derived by spectral methods which are independent of the discretization used for forward and inverse modeling. For illustration, we present case studies using synthetic data to estimate hydraulic conductivities on regular and unstructured grids. The results show that we can efficiently obtain a good estimate using the inverse method in conjunction with the KL expansion. We also demonstrate how to estimate structural parameters and to generate conditional realizations in the framework of our method.
Interplanetary shock in the magnetosheath: Comparison of experimental data with MHD modeling
Authors: Koval A. , Šafránková J. , Němeček Z. , Samsonov A. A. , Přech L. , Richardson J. D. , Hayosh M.
Published: June 2006

The paper continues the study of the evolution of interplanetary (IP) shocks in the solar wind and their propagation through the magnetosheath. We compare profiles of the magnetic field and plasma parameters observed experimentally by several spacecraft in the solar wind and magnetosheath with profiles of the same parameters generated by two MHD numerical models (the global 3D MHD BATS‐R‐US model and a local magnetosheath model). The experimental magnetosheath data are well reproduced by the model profiles even though the profiles exhibit complicated structure caused by the interaction of the IP shock with Earth's bow shock and magnetopause. The good agreement of experimental data with the model results suggests that kinetic effects play a minor role in these interactions.
Recent high‐latitude icy mantle in the northern plains of Mars: Characteristics and ages of emplacement
Authors: Kostama V.‐P. , Kreslavsky M. A. , Head J. W.
Published: June 2006

Martian high‐latitude zones are covered with a smooth, layered ice‐rich mantle containing characteristic polygonal patterns. The mantle is especially uniform and homogeneous in the northern plains. We performed a survey of decameter‐scale mantle textures and circular features, including impact craters, in the northern lowlands down to 50°N latitude. Strongly altered and mantled craters of impact and non‐impact origin form a population of subtle circular features below the mantle. Pits of non‐impact origin are numerous in some regions at lower latitudes. Impact craters superposed on the mantle are small and very sparse. The inferred mean crater retention age of the mantle is ∼0.1 Ma. The spatial distribution of young craters suggests an age difference between the highest latitudes (younger) and some lower‐latitude regions (older). Latitudinal trends in polygon textures agree with impact crater evidence for a latitudinal age progression of mantle properties.
A possible positive feedback of reduction of precipitation and increase in aerosols over eastern central China
Authors: Zhao Chunsheng , Tie Xuexi , Lin Yunping
Published: June 2006

In this study, observed precipitation, MODIS data and meteorological sounding data over eastern central China were analyzed. The result shows that the precipitation in this region is significantly reduced during the last 40 years and this reduction of precipitation is strongly correlated to the high concentrations of aerosols. Meteorological sounding data indicates that the atmospheric stability in the troposphere has been increasing during the last 17 years. It is speculated that the aerosol layer in the lower troposphere affects the radiative processes, which lead to changes in atmospheric stability. The enhancement in the atmospheric stability tends to depress upward motion and precipitation in this region. Because precipitation plays a major role for the sink for aerosol particles through washout process, less precipitation will lead to an increase in aerosol particles. This possible positive feed back cycle (more aerosols → less precipitation → more aerosols) will induce an acceleration process for the reduction of precipitation in eastern central China.
Winds of change?: Projections of near‐surface winds under climate change scenarios
Authors: Pryor S. C. , Schoof J. T. , Barthelmie R. J.
Published: June 2006

Changes in near–surface wind speeds due to global climate change may have profound geophysical and societal impacts. However, Global Climate Models (GCMs) are unable to replicate the historically observed magnitude and spatial variability of wind speeds, so we apply a downscaling technique to generate probability distributions of wind speeds at sites in northern Europe for historical periods (1961–1990 and 1982–2000) and two future periods (2046–2065, 2081–2100). Projections for the twenty‐first century (C21st) indicate no evidence of substantial evolution relative to the end of the twentieth century (C20th), although there is increased divergence of results from downscaling of different GCMs toward the end of C21st. Predicted changes in the downscaled mean and 90th percentile wind speeds are small (<±15%) and are comparable to the current variability manifest in downscaling from different GCMs.
On the stratospheric chemistry of hydrogen cyanide
Authors: Kleinböhl Armin , Toon Geoffrey C. , Sen Bhaswar , Blavier Jean‐François L. , Weisenstein Debra K. , Strekowski Rafal S. , Nicovich J. Michael , Wine Paul H. , Wennberg Paul O.
Published: June 2006

HCN profiles measured by solar occultation spectrometry during 10 balloon flights of the JPL MkIV instrument are presented. The HCN profiles reveal a compact correlation with stratospheric tracers. Calculations with a 2D‐model using established rate coefficients for the reactions of HCN with OH and O(1D) severely underestimate the measured HCN in the middle and upper stratosphere. The use of newly available rate coefficients for these reactions gives reasonable agreement of measured and modeled HCN. An HCN yield of ∼30% from the reaction of CH3CN with OH is consistent with the measurements.
Land use/land cover change effects on temperature trends at U.S. Climate Normals stations
Authors: Hale Robert C. , Gallo Kevin P. , Owen Timothy W. , Loveland Thomas R.
Published: June 2006

Alterations in land use/land cover (LULC) in areas near meteorological observation stations can influence the measurement of climatological variables such as temperature. Urbanization near climate stations has been the focus of considerable research attention, however conversions between non‐urban LULC classes may also have an impact. In this study, trends of minimum, maximum, and average temperature at 366 U.S. Climate Normals stations are analyzed based on changes in LULC defined by the U.S. Land Cover Trends Project. Results indicate relatively few significant temperature trends before periods of greatest LULC change, and these are generally evenly divided between warming and cooling trends. In contrast, after the period of greatest LULC change was observed, 95% of the stations that exhibited significant trends (minimum, maximum, or mean temperature) displayed warming trends.
Nonlinear ionic conductivity of lithium silicate glass studied via molecular dynamics simulations
Authors: Kunow Magnus , Heuer Andreas
Published: June 2006

Nonlinear ionic conductivity effects are studied via molecular dynamics simulations. We present numerical results for the field dependence of the current density as well as the second moment of the ion displacements. Furthermore we check whether structural changes occur upon application of strong electric fields. We obtain a complex picture of the field-dependent ion dynamics of a disordered system that is beyond simple model descriptions.
Computed lifetimes of metastable states of CO2+
Authors: Šedivcová T. , Žďánská P. R. , Špirko V. , Fišer J.
Published: June 2006

Highly correlated internally contracted multireference configuration interaction wave functions are used to calculate the potential energy and spin-orbit coupling functions for the lowest electronic states of CO2+ dication. Using these functions, the positions and lifetimes of the corresponding vibronic states are evaluated by means of log-phase-amplitude, stabilization, and complex-scaling methods within the framework of a multichannel Schrödinger analysis. For the first time in the literature, the calculated lifetimes are in good agreement with the experiment, thereby proving the reliability of the predicted characteristics and adequacy of the used theory for a theoretical study of other molecular dications.
Adaptive Q-S (lag, anticipated, and complete) time-varying synchronization and parameters identification of uncertain delayed neural networks
Authors: Yu Wenwu , Cao Jinde
Published: June 2006

In this paper, a new type of generalized Q-S (lag, anticipated, and complete) time-varying synchronization is defined. Adaptive Q-S (lag, anticipated, and complete) time-varying synchronization and parameters identification of uncertain delayed neural networks have been considered, where the delays are multiple time-varying delays. A novel control method is given by using the Lyapunov functional method. With this new and effective method, parameters identification and Q-S (lag, anticipated, and complete) time-varying synchronization can be achieved simultaneously. Simulation results are given to justify the theoretical analysis in this paper.
Dynamical noise filter and conditional entropy analysis in chaos synchronization
Authors: Wang Jiao , Lai C.-H.
Published: June 2006

It is shown that, in a chaotic synchronization system whose driving signal is exposed to channel noise, the estimation of the drive system states can be greatly improved by applying the dynamical noise filtering to the response system states. If the noise is bounded in a certain range, the estimation errors, i.e., the difference between the filtered responding states and the driving states, can be made arbitrarily small. This property can be used in designing an alternative digital communication scheme. An analysis based on the conditional entropy justifies the application of dynamical noise filtering in generating quality synchronization.
Researching the Sustainable City: Three Modes of Interdisciplinarity
Authors: Evans Robert , Marvin Simon
Published: June 2006

In this paper we explore the practice of interdisciplinarity by examining how the UK research councils addressed the problem of the sustainable city during the 1990s. In developing their research programmes, the councils recognised that the problems of the sustainable city transcended conventional disciplinary boundaries and that an interdisciplinary approach was needed. In practice, however, initially radical proposals to research the city as a complex combination of science and technology and society contracted into more cognate collaborations that emphasised either science or technology or society, with the result that interdisciplinarity came to be located within research councils rather than between them. This, in turn, led to the development of a third kind of interdisciplinarity as the responsibility for making the connections between the research programmes was outsourced to the user communities—the local authorities. Unfortunately, local authorities struggled to find the resources to conduct this work so that the radical interdisciplinarity recommended at the start of the decade remained unaccomplished at the end. In describing these events we emphasise roles of paradigms and epistemic cultures in shaping research approaches and the complications they raise for the triangulation between approaches that is assumed in the idea of interdisciplinarity. We do not wish to be entirely negative, however, and conclude by suggesting some ways in which the quality and success of this much-needed interdisciplinary work could be increased.
High floral bud abscission and lack of open flower abscission in Dendrobium cv. Miss Teen: rapid reduction of ethylene sensitivity in the abscission zone
Authors: Bunya-atichart Kanokpon , Ketsa Saichol , van Doorn Wouter G.
Published: June 2006

We studied the abscission of floral buds and open flowers in cut Dendrobium inflorescences. Abscission of floral buds was high and sensitive to ethylene in all cultivars studied. Many open flowers abscised in most cultivars, but cv. Willie exhibited only small amount of floral fall and cv. Miss Teen none. Applied ethylene (0.4 μL L–1 for 24 h at 27°C) greatly hastened abscission of open flowers in most cultivars, but had only a small effect in cv. Willie and no effect in cv. Miss Teen. Flower fall, if it occurred, was completely inhibited by 1-methylcyclopropene (1-MCP), showing that it was regulated by endogenous ethylene. Ethylene production from the abscission zones was low in all cultivars studied. In cv. Miss Teen the abscission zone changed from highly ethylene sensitive to completely insensitive in ~30 h, coinciding with floral opening. Removal of the floral buds somewhat reduced abscission in open flowers, but the lack of open flower abscission in cv. Miss Teen could not be explained by higher bud fall. The ovary did not grow in the (unpollinated) flowers, showing that lack of abscission in cvv. Willie and Miss Teen was not due to parthenocarpy. Flower removal in cv. Miss Teen had no effect on ethylene sensitivity of the abscission of the remaining pedicel. However, removal of the distal 2 cm of the 3-cm-long pedicels dramatically increased ethylene sensitivity. This suggests that the pedicel is important for the low ethylene insensitivity of abscission, in this cultivar. It is concluded that the abscission zones in the cvv. Willie and Miss Teen, in contrast with the other cultivars investigated, became rapidly insensitive to ethylene at the time of flower opening. At least part of the ethylene sensitivity in Miss Teen seems to be due to a factor in the pedicel.
Numerical study of a crown fire spreading toward a fuel break using a multiphase physical model
Authors: Dupuy Jean-Luc , Morvan Dominique
Published: June 2006

The propagation of a wildfire through a Mediterranean pine stand was simulated using a multiphase physical model of fire behaviour. The heterogeneous character of the vegetation was taken into account using families of solid particles, i.e. the solid phases (foliage, twigs, grass). The thermal decomposition of the solid fuel by drying and pyrolysis, and the combustion of chars were considered, as well as the radiative and convective heat transfer between the gas and the vegetation. In the gaseous phase, turbulence was modelled using a two transport equations model (RNG k–ϵ) and the rate of combustion, which was assumed to be controlled by the turbulent mixing of fuel and oxygen, was calculated using an eddy dissipation concept. The radiation transfer equation, which includes absorption and emission of both the gas–soot mixture and the vegetation, was solved to calculate the contribution of radiation to the energy balance equations. Numerical solutions were calculated in a two-dimensional domain (vertical plane). Results showed the ability of this approach to simulate the propagation of a crown fire and to test the efficiency of a fuel break with success. The effects of the terrain slope were also tested. Some effects on fire behaviour of vortices resulting from the interaction of the wind flow with the canopy layer are shown.
Molecular complexes in close and far away
Authors: Klemperer William , Vaida Veronica
Published: June 2006

In this review, gas-phase chemistry of interstellar media and some planetary atmospheres is extended to include molecular complexes. Although the composition, density, and temperature of the environments discussed are very different, molecular complexes have recently been considered as potential contributors to chemistry. The complexes reviewed include strongly bound aggregates of molecules with ions, intermediate-strength hydrogen bonded complexes (primarily hydrates), and weakly bonded van der Waals molecules. In low-density, low-temperature environments characteristic of giant molecular clouds, molecular synthesis, known to involve gas-phase ion-molecule reactions and chemistry at the surface of dust and ice grains is extended here to involve molecular ionic clusters. At the high density and high temperatures found on planetary atmospheres, molecular complexes contribute to both atmospheric chemistry and climate. Using the observational, laboratory, and theoretical database, the role of molecular complexes in close and far away is discussed.
Cluster dynamics transcending chemical dynamics toward nuclear fusion
Authors: Heidenreich Andreas , Jortner Joshua , Last Isidore
Published: June 2006

Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 10
15
–10
20
W·cm
−2
). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C
4+
(D
+
)
4
)

n

and (D
+
I
22+
)

n

at
I
M
= 10
18
W·cm
−2
, that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D
2
)

n

, (HT)

n

, (CD
4
)

n

, (DI)

n

, (CD
3
I)

n

, and (CH
3
I)

n

clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D
2
)

n

clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g.,
12
C(P,γ)
13
N driven by CE of (CH
3
I)

n

clusters, were explored.
AtALMT1
, which encodes a malate transporter, is identified as one of several genes critical for aluminum tolerance in
Arabidopsis
Authors: Hoekenga Owen A. , Maron Lyza G. , Piñeros Miguel A. , Cançado Geraldo M. A. , Shaff Jon , Kobayashi Yuriko , Ryan Peter R. , Dong Bei , Delhaize Emmanuel , Sasaki Takayuki , Matsumoto Hideaki , Yamamoto Yoko , Koyama Hiroyuki , Kochian Leon V.
Published: June 2006

Aluminum (Al) tolerance in
Arabidopsis
is a genetically complex trait, yet it is mediated by a single physiological mechanism based on Al-activated root malate efflux. We investigated a possible molecular determinant for Al tolerance involving a homolog of the wheat Al-activated malate transporter,
ALMT1
. This gene, named
AtALMT1
(At1g08430), was the best candidate from the 14-member
AtALMT
family to be involved with Al tolerance based on expression patterns and genomic location. Physiological analysis of a transferred DNA knockout mutant for
AtALMT1
as well as electrophysiological examination of the protein expressed in
Xenopus
oocytes showed that
AtALMT1
is critical for
Arabidopsis
Al tolerance and encodes the Al-activated root malate efflux transporter associated with tolerance. However, gene expression and sequence analysis of
AtALMT1
alleles from tolerant Columbia (Col), sensitive Landsberg
erecta
(Ler), and other ecotypes that varied in Al tolerance suggested that variation observed at
AtALMT1
is not correlated with the differences observed in Al tolerance among these ecotypes. Genetic complementation experiments indicated that the Ler allele of
AtALMT1
is equally effective as the Col allele in conferring Al tolerance and Al-activated malate release. Finally, fine-scale mapping of a quantitative trait locus (QTL) for Al tolerance on chromosome 1 indicated that
AtALMT1
is located proximal to this QTL. These results indicate that
AtALMT1
is an essential factor for Al tolerance in
Arabidopsis
but does not represent the major Al tolerance QTL also found on chromosome 1.
Redox sensor CtBP mediates hypoxia-induced tumor cell migration
Authors: Zhang Qinghong , Wang Su-Yan , Nottke Amanda C. , Rocheleau Jonathan V. , Piston David W. , Goodman Richard H.
Published: June 2006

The rapid growth and poor vascularization of solid tumors expose cancer cells to hypoxia, which promotes the metastatic phenotype by reducing intercellular adhesion and increasing cell motility and invasiveness. In this study, we found that hypoxia increased free NADH levels in cancer cells, promoting CtBP recruitment to the E-cadherin promoter. This effect was blocked by pyruvate, which prevents the NADH increase. Furthermore, hypoxia repressed E-cadherin gene expression and increased tumor cell migration, effects that were blocked by CtBP knockdown. We propose that CtBP senses levels of free NADH to control expression of cell adhesion genes, thereby promoting tumor cell migration under hypoxic stress.
Higher order nuclear organization: three-dimensional distribution of small nuclear ribonucleoprotein particles.
Authors: Spector D L
Published: June 2006

The structural and functional organization of the cell nucleus has been investigated using three-dimensional reconstruction, immunoelectron microscopy, and high-resolution in situ autoradiography. Nuclear regions enriched in small nuclear ribonucleoprotein particles (snRNPs) form a reticular network within the nucleoplasm that extends between the nucleolar surface and the nuclear envelope. The snRNPs occupy approximately 18% of the volume of CHOC 400 cell nuclei. The in situ sites of DNA replication and transcription are complementary to, rather than coincident with, the nuclear regions concentrated in snRNPs. Based on these data a three-dimensional model of the organization of the mammalian cell nucleus is presented.
Binding of substrate CO2 to the active site of human carbonic anhydrase II: a molecular dynamics study.
Authors: Liang J Y , Lipscomb W N
Published: June 2006

Molecular dynamics has been used to study binding of substrate CO2 to the active site of human carbonic anhydrase II. Three potential CO2 binding sites have been located. The first is at the active-site hydrophobic pocket (the catalytically productive site), where CO2 is approximately 3.5 A from the zinc ion and interacts with His-94, His-119, Val-121, Val-143, Leu-198, Thr-199, the zinc ion, and the zinc-bound hydroxide ion. The second CO2 binding site is approximately 6 A from the zinc ion, where CO2 interacts with His-64, His-94, Leu-198, Thr-200, Pro-201, Pro-202, and some active-site water molecules. The third CO2 binding site is approximately 10 A from the zinc ion, is largely solvated by water molecules, and interacts with His-64, Asn-67, and Gln-92. At these three CO2 binding sites, the CO2 molecule is highly localized (the average Zn-CO2 distance fluctuation is approximately 1 A) and favors the linear binding orientation toward the zinc ion. This linear binding orientation of CO2 and its electrostatic interaction with the zinc ion direct diffusion of CO2 toward the zinc ion and facilitate the nucleophilic attack from O of the zinc-bound OH- to C of CO2 in the productive hydrophobic binding site. Finally, the two CO2 binding sites outside the hydrophobic binding pocket, which may represent two intermediate states along the CO2 binding pathway, could play important roles as a CO2 relay.
Yeast Gal11 protein mediates the transcriptional activation signal of two different transacting factors, Gal4 and general regulatory factor I/repressor/activator site binding protein 1/translation upstream factor.
Authors: Nishizawa M , Suzuki Y , Nogi Y , Matsumoto K , Fukasawa T
Published: June 2006

GAL11 was first identified as a gene required for full expression of some of the galactose-inducible genes in the yeast Saccharomyces cerevisiae. A null mutation within the GAL11 locus causes defects in mating, growth on nonfermentable carbon sources, and sporulation of gal11 homozygotes. The mating defect was observed only in MAT alpha gal11 strains. Northern hybridization analysis revealed that a gal11 mutation impaired transcription of alpha-specific genes (MF alpha 1 and STE3) but not of an a-specific gene (STE2). Furthermore, this mutation reduced expression of the MAT alpha locus, suggesting that a deficiency in MAT alpha 1 protein is responsible for the reduced expression of alpha-specific genes. Since general regulatory factor I (GRFI)/repressor/activator site binding protein 1 (RAP1)/translation upstream factor (TUF) is believed to be an activator of MAT alpha expression, we examined whether PYK1, which is known to be regulated by GRFI/RAP1/TUF, is also affected by the gal11 mutation. It was determined that the level of PYK1 message was significantly lowered by the mutation. The requirement for functional GAL11 in transcriptional activation was bypassed when either the upstream activating sequence of galactose-inducible genes or of PYK1 was placed very close to the TATA box, suggesting that one of the Gal11 protein functions is to mediate the activation signal of Gal4 and GRFI/RAP1/TUF, when the respective binding site is situated at the naturally occurring distance from the TATA box.
Hypothesis: lipoprotein(a) is a surrogate for ascorbate.
Authors: Rath M , Pauling L
Published: June 2006

The concept that lipoprotein(a) [Lp(a)] is a surrogate for ascorbate is suggested by the fact that this lipoprotein is found generally in the blood of primates and the guinea pig, which have lost the ability to synthesize ascorbate, but only rarely in the blood of other animals. Properties of Lp(a) that are shared with ascorbate, in accordance with this hypothesis, are the acceleration of wound healing and other cell-repair mechanisms, the strengthening of the extracellular matrix (e.g., in blood vessels), and the prevention of lipid peroxidation. High plasma Lp(a) is associated with coronary heart disease and other forms of atherosclerosis in humans, and the incidence of cardiovascular disease is decreased by elevated ascorbate. Similar observations have been made in cancer and diabetes. We have formulated the hypothesis that Lp(a) is a surrogate for ascorbate in humans and other species and have marshaled the evidence bearing on this hypothesis.
Identification of a cleavage site directing the immunochemical detection of molecular abnormalities in type IIA von Willebrand factor.
Authors: Dent J A , Berkowitz S D , Ware J , Kasper C K , Ruggeri Z M
Published: June 2006

Proteolytic cleavage of the von Willebrand factor subunit may be important for processing and/or function of the molecule and is altered in certain subtypes of von Willebrand disease. It results in the generation of two main fragments with apparent molecular masses of 140 kDa and 176 kDa from the 225-kDa subunit. We have now obtained chemical evidence to locate the protease-sensitive bond between residues Tyr-842 and Met-843, a site that appears to reflect the specificity of calcium-dependent neutral proteases (calpains). Antibodies were raised against four synthetic peptides that represented sequences immediately preceding or following or including the cleavage site. One antibody (against the fragment from Ala-837 through Asp-851) reacted only with the intact subunit, and its epitope included the cleavage site. All others reacted specifically with either the 140-kDa or the 176-kDa fragment, demonstrating their origin from a single cleavage. In samples of purified von Willebrand factor from four of five patients with type IIA von Willebrand disease, the anti-peptide antibodies showed markedly decreased reactivity with either the 140-kDa or the 176-kDa fragment, suggesting the existence of distinct molecular abnormalities clustered around the cleavage site. Thus, in the majority of type IIA patients, a common pathogenetic mechanism may lead to the disappearance of the larger multimers as a consequence of structural changes that may expose a sensitive bond to the action of specific proteases. These studies demonstrate the use of anti-peptide antibodies directed at a relevant structural domain for the immunochemical differentiation of normal and mutant molecules.
Influenza virus hemagglutinin-specific antibodies isolated from a combinatorial expression library are closely related to the immune response of the donor.
Authors: Caton A J , Koprowski H
Published: June 2006

Antibodies specific for the influenza virus hemagglutinin have been isolated from a combinatorial expression library generated using mRNA obtained from an immunized donor mouse. Sequence analysis indicates that the antibody heavy chain variable regions were derived from members of an expanded hemagglutinin-specific B-cell clone, in conjunction with one of two light chain variable regions. Moreover, the most frequently identified heavy chain variable/light chain variable combination is extremely similar to a heavy chain variable/light chain variable combination that has previously been identified among hemagglutinin-specific hybridoma antibodies. The results, therefore, demonstrate that these antibodies bear a close relationship to the immune status of the donor mouse and suggest that simple adaptations of this procedure might allow evaluation of the immune responses of species, such as man, in which conventional hybridoma techniques have to date proven ineffective.