bluuebunny/crossref_metadata_2025 huggingface dataset:
Sieben Arten der Lernmotivation
Authors: Urhahne Detlef
Published: October 2008

Zusammenfassung. Der Artikel vermittelt einen Überblick über zentrale theoretische Ansätze der Lernmotivationsforschung. Als integrativer Rahmen zur Darstellung dient dabei ein Handlungsmodell, das in Anlehnung an Heckhausen und Heckhausen (2006) entstanden ist. Es werden sieben Arten von Lernmotivationstheorien vorgestellt und in das Handlungsmodell eingeordnet: klassische Leistungsmotivationstheorie, erweiterte Erwartungs-Wert-Theorien, Attributionstheorien, Zielorientierungskonzepte, Theorien intrinsischer Motivation, Volitionsmodelle und Theorien sozialer Motivation. Für jede Theorieart wird aufgezeigt, an welche Prozesse im Handlungsverlauf die Motivation gebunden ist. Dadurch treten Gemeinsamkeiten und Unterschiede zwischen den Motivationstheorien deutlich hervor. Zur Veranschaulichung des Zusammenhangs zwischen Motivation und Lernleistung auf empirischer Ebene werden die Befunde aus Metaanalysen präsentiert.
A 5 million year comparison of Mg/Ca and alkenone paleothermometers
Authors: Dekens Petra S. , Ravelo Ana Christina , McCarthy Matthew D. , Edwards Christopher A.
Published: October 2008

Geochemical sea surface temperature (SST) proxies such as the magnesium to calcium ratio (Mg/Ca) in foraminifera and the alkenone unsaturation index (UK′37) are becoming widely used in pre‐Pleistocene climate records. This study quantitatively compares previously published Mg/Ca and UK′37 data from Ocean Drilling Program (ODP) site 847 in the eastern equatorial Pacific to assess the utility of these proxies to reconstruct tropical SST over the last 5 Ma. Foraminiferal Mg/Ca–SST calibrations that include a dissolution correction are most appropriate at this location because they provide SST estimates for the youngest sample that are close to modern mean annual SST. The long‐term trends in the two records are remarkably similar and confirm a ∼3.5°C cooling trend from the early Pliocene warm period to the late Pleistocene noted in previous work. Absolute temperature estimates are similar for both proxies when errors in the dissolution correction used to estimate SST from Mg/Ca are taken into account. Comparing the two SST records at ODP site 847 to other records in the region shows that the eastern equatorial Pacific was 2–4°C warmer during the early Pliocene compared to today.
The Stromboli 2002 tsunamigenic submarine slide: Characteristics and possible failure mechanisms
Authors: Chiocci Francesco L. , Romagnoli Claudia , Tommasi Paolo , Bosman Alessandro
Published: October 2008

On 30 December 2002, a major instability event, deeply involving the submarine slope, occurred on the Sciara del Fuoco, on the western flank of Stromboli volcano, in the Aeolian Islands. Tsunami waves with a maximum runup of over 10 m in Stromboli were generated, having a measurable impact as far as the Sicily coast. Just 10 months before the event, a multibeam bathymetry had been collected in the area down to 1000 m of depth. A repetition of the survey after the slide allowed the unique opportunity to verify the occurrence of a large submarine slide and to define volumes involved and morphology generated by the event, through the comparison of the preevent and postevent bathymetric grids. A morphological characterization of the slope before and after the submarine landslide is presented, showing how the preexisting features interacted with the slide event in controlling the instability. Mechanisms of the submarine failure are discussed on the basis of the geometrical characters of the landslide event, structural and stratigraphic setting of the submerged slope, and geotechnical considerations on the behavior of slope material.
Lithospheric structure of the Bohemian Massif and adjacent Variscan belt in central Europe based on profile S01 from the SUDETES 2003 experiment
Authors: Grad Marek , Guterch Aleksander , Mazur Stanisław , Keller G. Randy , Špičák Aleš , Hrubcová Pavla , Geissler Wolfram H.
Published: October 2008

The SUDETES 2003 seismic experiment investigated the lithospheric structure of the eastern part of the Variscan belt of central Europe. The key profile of this experiment (S01) was 630 km long and extended southwestward from the margin of the East European craton, across the Trans‐European suture zone (TESZ) and Sudetes, and across the Bohemian Massif that contains the active Eger (Ohře) rift, which is an element of the European Cenozoic rift system. Good quality first arrivals and later phases of refracted/reflected P and S waves were interpreted using 2‐D ray‐tracing techniques. The derived seismic model shows large variations in the internal structure of the crust, while the depth to the Moho varies in the relatively narrow depth interval of 28–35 km. Except for the Polish basin on the northeast end of the profile, the sedimentary cover is thin. The crystalline upper and middle crust with velocities of 5.9–6.4 km s−1 is about 20 km thick, and the 7–10 km thick lower crust can be divided into three regions based on P wave velocities: a low‐velocity region (6.5–6.6 km s−1 beneath Eger rift and Sudetes) that is bounded on the southwest and northeast by regions of significantly higher velocity (6.8–7.1 km s−1 beneath the Saxothuringian and Moldanubian in the southwest and Fore‐Sudetic Monocline and Polish Basin in the northeast). High‐velocity bodies (Vp > 6.5 km s−1) were delineated in the upper crust of the Eger rift region. The seismic structure along the S01 profile images a Variscan orogenic wedge resting on the down warped margin of the plate margin containing the TESZ. This situation implies the northerly directed subduction of the Rheic Ocean that existed between the southern margin of the Old Red Continent and the Armorican terranes presently accreted into the Variscan belt. Closure of this ocean produced the Rheic suture between low‐velocity crust of the Variscan orogenic wedge and higher‐velocity crust of the TESZ.
Stokes drift–induced and direct wind energy inputs into the Ekman layer within the Antarctic Circumpolar Current
Authors: Wu Kejian , Liu Bin
Published: October 2008

Theoretical analysis of energetics of the Ekman layer by incorporating the Coriolis‐Stokes forcing into the classical Ekman model shows that the wind energy input to the Ekman layer has two components: the work done by the wind stress on the surface Ekman current and that done by the Coriolis‐Stokes forcing on the whole body of water in the mixed layer. Under the assumption of constant vertical diffusivity, analytical forms of the direct wind energy input and the Stokes drift–induced energy input are derived. Assessments of relative importance of surface waves are made by comparing the wind energy input into the Ekman layer with and without wave‐induced Stokes drift effects included. Using the European Centre for Medium‐Range Weather Forecasts 40‐year reanalysis wind stress and surface wave data sets, the total rate of wind energy input into the Ekman layer within the Antarctic Circumpolar Current (ACC) is estimated to be 833 GW, in which the direct wind energy input is 650 GW (78%), and the Stokes drift–induced energy input is 183 GW (22%). The total mechanical energy input into the ACC due to wave effects is increased by approximately 4% (30 GW) compared to that into the classical Ekman layer. Long‐term variability of direct wind and Stokes drift–induced energy inputs to the ACC is also examined.
Mesoscale eddies and wind variability in the northern Gulf of California
Authors: Lopez‐Calderon Jorge , Martinez Antonio , Gonzalez‐Silvera Adriana , Santamaria‐del‐Angel Eduardo , Millan‐Nuñez Roberto
Published: October 2008

Surface mesoscale structures and wind variability in the northern Gulf of California (NGC) were analyzed using data from SeaWiFS (1 km) and QuikSCAT (1 day). The months of February and March were selected as representative of winter and the months of August and September were selected as representative of summer. Chlorophyll‐a (Chla) and wind time series were constructed using 16 points to analyze temporal variability and wind magnitude‐Chla temporal and spatial linear correlation. Wind components along and across the NGC were found to play an equally significant role regarding wind variability, contrary to what is currently recognized. Wind magnitude tended to be stronger in winter and had less wind direction variability than in summer. A bimodal wind pattern was registered for each season, each wind direction explaining less than 30% of total variability. The zone with minimum variability in wind direction and maximum variability in wind magnitude was located northwest of the NGC, the same area where wind magnitude‐Chla correlation was significant (p < 0.05). Winter and summer surface circulation patterns are more complex than currently documented. Summer is characterized by numerous plumes and eddies (especially anticyclonic), some traveling from coast to coast, enhancing the exchange of suspended material. Winter varied greatly interannualy, also showing many plumes and eddies (especially cyclonic), but was very heterogeneous, opposite to summer. Significant summer correlation was mostly positive, whereas in winter the significant correlation was equally positive and negative, maybe as a consequence of higher nutrient availability during this season.
Diagnostic analyses of a regional air quality model: Changes in modeled processes affecting ozone and chemical‐transport indicators from NOx point source emission reductions
Authors: Godowitch J. M. , Hogrefe C. , Rao S. T.
Published: October 2008

The impact of nitrogen oxide (NOx) emission reductions from major point sources on the key physical and chemical processes contributing to ozone formation and accumulation is studied, and the extent of change in the chemical regime is examined using selected photochemical indicators in the eastern United States. The Community Multiscale Air Quality (CMAQ) chemical‐transport model, equipped with the process analysis technique, was applied in modeling scenarios involving 2002 base case emissions and an emissions scenario containing real‐world point source NOx reductions implemented before the summer ozone season of 2004. Spatial patterns and temporal variations in process rates and changes in chemical‐transport indicators are highlighted from results of summer 2002 days, representative of generally southwesterly wind flows across the Midwestern source region with ozone transport toward the northeastern states. Substantial decreases exceeding 50% in O3 chemical production rates were associated with the largest NOx point source emission reductions, causing declines in ozone concentrations at the surface and aloft in downwind areas. The decreases in the various physical processes and their spatial difference patterns closely resembled the change in maximum O3 concentrations. The net ozone production efficiency was found to increase, since the decline in O3 concentrations was less than the decrease in reactive nitrogen products (NOz). The O3/NOx ratio also increased between the base case and NOx reduction scenario results, indicating a noticeable shift in the chemical regime toward more NOx‐limited conditions in plume‐impacted areas downwind of the sources. The drop in surface NOx concentrations in modeled and observed results at a location just downwind of the Ohio River Valley source region is attributable to the point source NOx emission reductions.
Effects of selective logging on tropical forest tree growth
Authors: Figueira Adelaine Michela e S. , Miller Scott D. , de Sousa Cleilim Albert D. , Menton Mary C. , Maia Augusto R. , da Rocha Humberto R. , Goulden Michael L.
Published: October 2008

We combined measurements of tree growth and carbon dioxide exchange to investigate the effects of selective logging on the Aboveground Live Biomass (AGLB) of a tropical rain forest in the Amazon. Most of the measurements began at least 10 months before logging and continued at least 36 months after logging. The logging removed ∼15% of the trees with Diameter at Breast Height (DBH) greater than 35 cm, which resulted in an instantaneous 10% reduction in AGLB. Both wood production and mortality increased following logging, while Gross Primary Production (GPP) was unchanged. The ratio of wood production to GPP (the wood Carbon Use Efficiency or wood CUE) more than doubled following logging. Small trees (10 cm < DBH < 35 cm) accounted for most of the enhanced wood production. Medium trees (35 cm < DBH < 55 cm) that were within 30 m of canopy gaps created by the logging also showed increased growth. The patterns of enhanced growth are most consistent with logging‐induced increases in light availability. The AGLB continued to decline over the study, as mortality outpaced wood production. Wood CUE and mortality remained elevated throughout the 3 years of postlogging measurements. The future trajectory of AGLB and the forest's carbon balance are uncertain, and will depend on how long it takes for heterotrophic respiration, mortality, and CUE to return to prelogging levels.
A modeling assessment of the interplay between aeolian iron fluxes and iron‐binding ligands in controlling carbon dioxide fluctuations during Antarctic warm events
Authors: Parekh Payal , Joos Fortunat , Müller Simon A.
Published: October 2008

We add a prognostic biogeochemical model to the Bern3D ocean circulation model to test the impact of increased aeolian iron fluxes in various regions of the ocean on long time scales. Atmospheric CO2 is most sensitive when modern dust flux is increased 100‐fold in the Southern Ocean for 1000 years, resulting in a reduction of 10 ppmv. Seeding the Indian Ocean and South Pacific results in increased export production and CO2 drawdown in the Southern Ocean due to interbasinal transport of iron. The non‐sea‐salt calcium record from Dome C, Antarctica, is used to scale aeolian iron deposition in the Southern Ocean in transient simulations over four Antarctic warm events of the last glacial period. Our results suggest changes in dust flux to the Southern Ocean played a limited role in modulating CO2 variations. The impact of iron fluxes on CO2 is dependent on parameter values chosen for the iron‐binding ligand.
Simulation of the Stokes vector in inhomogeneous precipitation
Authors: Adams Ian Stuart , Gaiser Peter , Jones W. Linwood
Published: October 2008

The large absorption and scattering cross sections of liquid and frozen hydrometeors, respectively, introduce appreciable signatures to measured polarized brightness temperatures, degrading the retrieval of other geophysical parameters such as near‐surface ocean winds. In particular, the retrieval of wind direction requires precise knowledge of polarization. This study investigates the fully polarized atmospheric contribution of precipitation and compares these effects with the current sensitivities of passive wind vector retrieval algorithms. A realistic microphysical cloud model supplies atmospheric parameters, including hydrometeor water contents, which are input into a vector radiative transfer model. Scattering is handled using a reverse Monte Carlo method. Radiances are simulated for three frequencies of interest to microwave polarimetry, 10.7, 18.7, and 37.0 GHz, for the four elements of the Stokes vector. The simulations show that the dichroic nature of precipitating media has a significant impact on passive wind vector retrievals.
Longer‐term effects of pine and eucalypt plantations on streamflow
Authors: Scott David F. , Prinsloo F. W.
Published: October 2008

The longer‐term effects of afforestation with Pinus radiata and Eucalyptus grandis on streamflows were analyzed using data from two paired‐catchment experiments in South Africa. The experiments are rare in that they have been maintained over longer periods than the typical rotation period for industrial timber plantations in the tropics or subtropics. In both experiments the planting treatments led to large reductions in streamflow, which increased with the age of the trees and were positively related to water availability. The pine plantation caused peak reductions in yield over a 5‐year period of 44 mm a−1 or 7.7% a−1 for each 10% of catchment planted when the trees were between 10 and 20 years old. The eucalypt plantation caused peak reductions over a 3‐year period of 48 mm a−1 and 10% a−1 for each 10% of catchment planted. However, as the plantations matured (over 30 years of age in the case of pines and over 15 years of age in the case of eucalypts) the flow reduction trend was reversed, and streamflow effects appear to be tending toward preafforestation levels. The longer‐term effects of planted forests need not be as harmful on the water yield of catchments as has been predicted from shorter‐term studies. The implication of these results is that if trees are grown on very long rotations, they may be used for restoring degraded catchments or as a means of storing carbon without completely denuding available water resources.
Small unmonitored near‐coastal catchment areas yielding large mass loading to the sea
Authors: Destouni Georgia , Hannerz Fredrik , Prieto Carmen , Jarsjö Jerker , Shibuo Yoshihiro
Published: October 2008

Continental freshwater transports and loads excess nutrients and pollutants from various land surface sources into downstream inland and coastal water environments. This study shows that even small, hydrologically unmonitored near‐coastal catchment areas may generate large nutrient and pollutant mass loading to the sea of a magnitude similar to or greater than monitored river loads. Systematic near‐coastal gaps in the monitoring of freshwater discharges to the sea may therefore mislead the quantification of coastal mass loading significantly. A methodology is presented for quantifying the mass load contributions of all the different unmonitored pathways of hydrological mass transport to the coast, including unmonitored river parts, whole unmonitored streams, and submarine groundwater discharge. This can be used for guiding future efforts to improve monitoring so that it includes the essential hydrological pathways of nutrient and pollutant loading to the sea.
Methane, manganese, and helium‐3 in newly discovered hydrothermal plumes over the Central Indian Ridge, 18°–20°S
Authors: Kawagucci Shinsuke , Okamura Kei , Kiyota Kaoru , Tsunogai Urumu , Sano Yuji , Tamaki Kensaku , Gamo Toshitaka
Published: October 2008

We have investigated newly discovered submarine hydrothermal plumes over the Central Indian Ridge, 18°–20°S. Onshore chemical analyses of methane, its carbon isotope, manganese, and helium‐3 in seawater samples obtained from the plumes revealed their detailed geochemical characteristics. One of the newly discovered hydrothermal plumes located over the western wall of the axial valley at Segment 15B (19°33′S), called the Roger Plateau, showed constant CH4/Mn and CH4/3He ratios throughout the plume. The CH4/3He ratio (4 × 106) and δ13C (−17.5‰) are consistent with those of basalt‐hosted sediment‐free hydrothermal systems, although the CH4/Mn ratio (∼1) is moderately higher. These features are thought to indicate a metal‐depleted fluid chemistry. The other hydrothermal field is located within the axial valley at the northern part of the smooth lava plain at Segment 16 (18°20′S), called the Dodo Great Lava Plain, where several plumes were detected. The CH4/Mn and CH4/3He ratios showed large variation through the plumes while δ13C values were almost constant. Geochemical characteristics of venting fluid estimated from those of the plumes were apparently high CH4/Mn (>6) and CH4/3He (>60 × 106) ratios and low δ13C values (<−27.5‰), suggesting possible influences of several methane input processes to the fluid chemistry.
A preliminary investigation of chlorine XANES in silicate glasses
Authors: Evans K. A. , Mavrogenes J. A. , O'Neill H. S. , Keller N. S. , Jang L.‐Y.
Published: October 2008

Chlorine speciation in silicate melts affects volatile exsolution, rheology, and thermodynamic properties of the melt but is poorly known. X‐Ray Absorption Near Edge Structure (XANES) spectra have been used to investigate Cl speciation in 26 silicate glasses and to test the hypothesis that Cl in silicate melts is hosted by species that combine Cl and network‐modifying cations such as Ca and Mg. Results indicate that Cl in CMAS (CaO‐MgO‐Al2O3‐SiO2) plus Na2O, K2O, or MnO silicate glasses exists as a combination of Ca‐Clx and Mg‐Clx species or, possibly, as mixed Ca‐Mgy‐Clx species. The geometry and stoichiometry of the proposed species is unknown, but there are similarities between spectra from Ca‐bearing melts and the spectra of hydrated CaCl2.2H2O, suggesting that the Ca‐Clx species could have a salt‐like atomic arrangement and ionic bonding. Further investigations using XANES, alternative spectroscopic techniques, and forward modeling approaches are required to distinguish between these possibilities.
Sulphur isotopic ratios in mosses indicating atmospheric sulphur sources in southern Chinese mountainous areas
Authors: Xiao Hua‐Yun , Tang Cong‐Guo , Liu Xue‐Yan , Xiao Hong‐Wei , Liu Cong‐Qiang
Published: October 2008

Many mountainous regions in South China have been confronted with the consequences of acidic deposition, but studies on atmospheric S sources are still very limited. In this study, isotopic ratios in mosses were used to discriminate atmospheric S sources. A continuous increase in S isotopic ratios was observed from the south to the north in mountainous mosses and in accord with the previously reported changing trends in urban mosses, indicating a contribution of local anthropogenic S from urban cities. Based on comparisons of S isotopic ratios in mountainous mosses with those in nearby urban mosses, we found that mountainous mosses had significantly higher 34S contents than urban mosses, especially in West China, reflecting an introduction of 34S‐enriched sulphur. In conjunction with cloud water data in the literature, we concluded that 34S‐enriched sulphur in northerly air masses contributed much to atmospheric S in southern Chinese mountainous areas.
Concerning the dissipation of electrically charged objects in the shadowed lunar polar regions
Authors: Farrell W. M. , Stubbs T. J. , Delory G. T. , Vondrak R. R. , Collier M. R. , Halekas J. S. , Lin R. P.
Published: October 2008

NASA recently suggested the construction of a lunar outpost at the south pole near the rim of Shackleton crater. While there are a number of advantages to such a base, the region will have periods of time when there is limited or no solar illumination ‐ thereby reducing photoelectric and solar wind plasma currents compared to most of the lunar dayside. As a consequence of this reduction in environmental currents, we find that human systems charged by contact electrification with the regolith (e.g., roving, excavation) will have increased difficulty in removing accumulated electric charge. This situation is especially true within the cold, shadowed regions adjacent to the terminator (such as within Shackleton crater itself) where there are essentially no photoelectric currents, vastly reduced plasma currents (due to the local wake) and a highly‐reduced regolith conductivity. In essence, there is no pathway for accumulated charge to “leak away” or dissipate, thereby creating an electrostatic hazard. Calculated dissipation timescales are found to be ∼1 millisecond in the weakly sunlit terminator region and dayside but could approach 100's of seconds in the “current‐starved” shadowed regions.
Effects of plasma density irregularities on the pitch angle scattering of radiation belt electrons by signals from ground based VLF transmitters
Authors: Bell T. F. , Inan U. S. , Piddyachiy D. , Kulkarni P. , Parrot M.
Published: October 2008

Recent DEMETER spacecraft observations show that VLF signals from the NPM transmitter in Hawaii often strongly excite quasi‐electrostatic whistler mode waves as the NPM signals propagate upward through plasma density irregularities. As a result of the NPM wave energy loss to the quasi‐electrostatic waves, the transmitter signals will arrive at the radiation belts with less intensity than predicted by present models of VLF wave propagation and will produce less pitch angle scattering of energetic electrons than presently believed. This type of wave energy loss may be partially responsible for the pervasive wave intensity deficit for VLF transmitter signals in the plasmasphere recently noted by Starks et al. (2008).
Response of California temperature to regional anthropogenic aerosol changes
Authors: Novakov T. , Kirchstetter T. W. , Menon S. , Aguiar J.
Published: October 2008

In this paper, we compare constructed records of concentrations of black carbon (BC) ‐ an indicator of anthropogenic aerosols ‐ with observed surface temperature trends in California. Annual average BC concentrations in major air basins in California significantly decreased after about 1990, coincident with an observed statewide surface temperature increase. Seasonal aerosol concentration trends are consistent with observed seasonal temperature trends. These data suggest that the reduction in anthropogenic aerosol concentrations contributed to the observed surface temperature increase. Conversely, high aerosol concentrations may lower surface temperature and partially offset the temperature increase of greenhouse gases.
Excess air in the noble gas groundwater paleothermometer: A new model based on diffusion in the gas phase
Authors: Sun Tie , Hall Chris M. , Castro Maria Clara , Lohmann Kyger C. , Goblet Patrick
Published: October 2008

A key assumption for calculating paleotemperatures using noble gas concentrations in groundwater is that water equilibrates with standard air. However, if the unsaturated zone is depleted in O2, the noble gas partial pressures will be elevated, resulting in a bias of noble gas temperatures (NGTs) to low values. This oxygen depletion (OD) mechanism was used to explain low NGT values for a shallow aquifer in Michigan where new O2 saturation and CO2 measurements now confirm the OD model. Measured excess He, without an expected vertical concentration gradient in the water phase, suggests that the rate of noble gas equilibration at the base of the unsaturated zone is restricted, and that transport within the gas phase may be a rate‐limiting step. A new NGT model is presented that uses the OD mechanism and that allows for partial re‐equilibration of excess air via diffusion in the gas phase.
Mass release process in the Jovian magnetosphere: Statistics on particle burst parameters
Authors: Kronberg E. A. , Woch J. , Krupp N. , Lagg A.
Published: October 2008

The Jovian magnetosphere undergoes periodic reconfiguration processes mainly driven by the fast planetary rotation and mass loading from the moon Io. These reconfiguration processes of the Jovian magnetosphere are associated with the release of plasmoids discernible as ion flow bursts associated with bipolar magnetic signatures. We investigate these plasma flows statistically using data from the Energetic Particles Detector and from the magnetometer on board Galileo. The plasma flows are observed in different magnetospheric regions: the current sheet center, the plasma sheet boundary layers, and the lobe. We show that the bulk velocity of all species is the same for most of the magnetic field bipolar signatures associated with these plasma flows. The average speed of the observed plasmoids in the plasma sheet associated with the ion flow bursts is between 350 and 500 km s−1, and the duration of the events is between 10 and 20 min. The associated plasmoid length is correspondingly ∼9 RJ. The plasmoids are moving approximately with Alfvénic speed. The convection electric field during the plasmoid release is about an order of magnitude higher than the ambient value of the Jovian convection electric field.
Regional four‐dimensional hydrological mass variations from GRACE, atmospheric flux convergence, and river gauge data
Authors: Schmidt M. , Seitz F. , Shum C. K.
Published: October 2008

The spatiotemporal behavior of the Earth's gravity field is traditionally modeled as a series expansion in terms of spherical harmonics with a number of time‐dependent coefficients. In this contribution we study regional effects, namely, hydrological mass variations observed by the Gravity Recovery And Climate Experiment (GRACE) satellite mission since 2002. As compared to the global spherical harmonics, scaling and wavelet functions are quasi‐compactly supported, i.e., highly localizing with respect to space and time. Consequently, they establish a system of base functions well suited for regional modeling. We determine a spatiotemporal regional gravity model from GRACE using the spherical wavelet technique for the spatial part and a one‐dimensional B spline expansion for the temporal variations; that is, we end up with a four‐dimensional multiresolution representation (MRR) of the geopotential over selected regional areas and time intervals. For an exemplary area consisting of three large river basins in South America we compute mass variations expressed in terms of equivalent water heights. We demonstrate that a B spline expansion for modeling the temporal behavior is more appropriate than the classical Fourier series approach. In order to corroborate the results, our storage estimates are balanced with the net effect of river discharge from gauges (outflow) and the difference of precipitation and evaporation (inflow) from the convergence of vertically integrated water vapor fluxes. Furthermore, our results are compared with monthly mass grids from GRACE spherical harmonic solution data products. We conclude that the MRR means a robust tool to maximize the observational accuracy for GRACE, it considers the spatiotemporal resolution of the observations due to resolution‐dependent highest levels, and it is applicable elsewhere globally to model hydrological or other phenomena of mass change.
Interactions between thin‐ and thick‐skinned tectonics at the northwestern front of the Jura fold‐and‐thrust belt (eastern France)
Authors: Madritsch Herfried , Schmid Stefan M. , Fabbri Olivier
Published: October 2008

This study investigates spatial and temporal interactions of thin‐ and thick‐skinned tectonics in a classical foreland setting located at the front of the Jura fold‐and‐thrust belt in eastern France. The working area coincides with the intracontinental Rhine‐Bresse Transfer Zone and represents the most external front of the deformed Alpine foreland. The investigation combines analyses of largely unpublished and newly available subsurface information with our own structural data, including an exhaustive paleostress analysis and geomorphologic observations. Results are provided in the form of a new tectonic map and a series of regional cross sections through the study area. The Besançon Zone, forming the most external part of the thin‐skinned fold‐and‐thrust belt, encroached onto the Eo‐Oligocene Rhine‐Bresse Transfer Fault System until early Pliocene times. Thrust propagation was largely controlled by the Late Paleozoic to Paleogene preexisting fault pattern that characterizes the Rhine‐Bresse Transfer Zone. Thick‐skinned deformation, dominant throughout the Avant‐Monts Zone located farther to the west, was associated with compressional to transpressional reactivation of such faults. Overprinting and crosscutting criteria of fault slip data allow distinguishing between systematically fanning maximum horizontal stress axes that define the front of the thin‐skinned Jura fold‐and‐thrust belt and consistently NW–SE directed maximum horizontal stress axes that characterize deformation of the autochthonous cover of the foreland, which is affected by thick‐skinned tectonics. Tectonic and geomorphic analyses indicate that thick‐skinned tectonics started at a very late stage of foreland deformation (post‐early Pliocene). Geomorphic observations imply that deformation between Mesozoic cover and basement is locally still decoupled. However, overprinting relationships and recent seismicity suggest that present‐day tectonic activity is thick skinned, which probably reflects ongoing tectonic underplating in the Alpine foreland.
Rheic Ocean ophiolitic remnants in southern Iberia questioned by SHRIMP U‐Pb zircon ages on the Beja‐Acebuches amphibolites
Authors: Azor A. , Rubatto D. , Simancas J. F. , González Lodeiro F. , Martínez Poyatos D. , Martín Parra L. M. , Matas J.
Published: October 2008

The Rheic Ocean was a major oceanic domain between Avalonia and Gondwana in Ordovician‐Silurian times. Most of the Paleozoic plate reconstructions assume that the Rheic Ocean suture lies within southern Iberia, coinciding with the contact between the South Portuguese Zone and the Ossa‐Morena Zone. This paper reports four Sensitive High Resolution Ion Micro‐Probe (SHRIMP) U‐Pb zircon ages from mid‐ocean ridge basalt (MORB)‐featured rocks of the Beja‐Acebuches Amphibolite unit, which crops out along the boundary between the Ossa‐Morena and the South Portuguese Zone, and is considered its most conspicuous suture unit. The obtained ages range from 332 ± 3 to 340 ± 4 Ma, corresponding to the crystallization of the mafic protoliths. These Early Carboniferous ages for the Beja‐Acebuches amphibolites imply that this unit can no longer be viewed as an ophiolite belonging to the Rheic Ocean suture, since this oceanic domain was presumably closed in Devonian times. Tectonic reconstructions joining in a single suture line the Beja‐Acebuches Amphibolite unit in southern Iberia to either the Devonian Lizard ophiolite in southern England or the root zone of the Devonian/Ordovician ophiolitic units in northwest Iberia must be therefore reconsidered because of the age difference. We interpret the Beja‐Acebuches Amphibolite unit to represent a narrow and very ephemeral realm of oceanic‐like crust that opened in Early Carboniferous times, after total consumption of the Rheic Ocean. We suggest that a mantle plume underneath southern Iberia in Early Carboniferous times is the most plausible large‐scale geodynamic scenario for the formation of these MORB‐featured rocks.
Endothelial Protein C Receptor-Assisted Transport of Activated Protein C across the Mouse Blood—Brain Barrier
Authors: Deane Rashid , LaRue Barbra , Sagare Abhay P , Castellino Francis J , Zhong Zhihui , Zlokovic Berislav V
Published: October 2008

Activated protein C (APC), a serine-protease with anticoagulant, anti-inflammatory, and cytoprotective activities, is neuroprotective and holds potential to treat different neurologic disorders. It is unknown whether APC crosses the blood—brain barrier (BBB) to reach its therapeutic targets in the brain. By using a brain vascular perfusion technique, we show that 125I-labeled plasma-derived mouse APC enters the brain from cerebrovascular circulation by a concentration-dependent mechanism. The permeability surface area product of 125I-APC (0.1 nmol/L) in different forebrain regions ranged from 3.11 to 4.13 μL/min/g brain. This was approximately 80- to 110-fold greater than for 14C-inulin, a simultaneously infused reference tracer. The Km value for APC BBB cortical transport was 1.6±0.2 nmol/L. Recombinant APC variants with reduced anticoagulant activity, 5A-APC and 3K3A-APC, but not protein C, exhibited high affinity for the APC BBB transport system. Blockade of APC-binding site on endothelial protein C receptor (EPCR), but not blockade of its protease-activated receptor-1 (PAR1) catalytic site, inhibited by > 85% APC entry into the brain. APC brain uptake was reduced by 64% in severely deficient EPCR mice, but not in PAR1 null mice. These data suggest that APC and its variants with reduced anticoagulant activity cross the BBB via EPCR-mediated saturable transport.
Two biochemically distinct and tissue-specific twinfilin isoforms are generated from the mouse Twf2 gene by alternative promoter usage
Authors: Nevalainen Elisa M. , Skwarek-Maruszewska Aneta , Braun Attila , Moser Markus , Lappalainen Pekka
Published: October 2008

Twf (twinfilin) is an evolutionarily conserved regulator of actin dynamics composed of two ADF-H (actin-depolymerizing factor homology) domains. Twf binds actin monomers and heterodimeric capping protein with high affinity. Previous studies have demonstrated that mammals express two Twf isoforms, Twf1 and Twf2, of which at least Twf1 also regulates cytoskeletal dynamics by capping actin filament barbed-ends. In the present study, we show that alternative promoter usage of the mouse Twf2 gene generates two isoforms, which differ from each other only at their very N-terminal region. Of these isoforms, Twf2a is predominantly expressed in non-muscle tissues, whereas expression of Twf2b is restricted to heart and skeletal muscle. Both proteins bind actin monomers and capping protein, as well as efficiently capping actin filament barbed-ends. However, the N-terminal ADF-H domain of Twf2b interacts with ADP-G-actin with a 5-fold higher affinity than with ATP-G-actin, whereas the corresponding domain of Twf2a binds ADP-G-actin and ATP-G-actin with equal affinities. Taken together, these results show that, like Twf1, mouse Twf2 is a filament barbed-end capping protein, and that two tissue-specific and biochemically distinct isoforms are generated from the Twf2 gene through alternative promoter usage.
The transporter CefM involved in translocation of biosynthetic intermediates is essential for cephalosporin production
Authors: Teijeira Fernando , Ullán Ricardo V. , Guerra Susana M. , García-Estrada Carlos , Vaca Inmaculada , Martín Juan F.
Published: October 2008

The cluster of early cephalosporin biosynthesis genes (pcbAB, pcbC, cefD1, cefD2 and cefT of Acremonium chrysogenum) contains all of the genes required for the biosynthesis of the cephalosporin biosynthetic pathway intermediate penicillin N. Downstream of the cefD1 gene, there is an unassigned open reading frame named cefM encoding a protein of the MFS (major facilitator superfamily) with 12 transmembrane domains, different from the previously reported cefT. Targeted inactivation of cefM by gene replacement showed that it is essential for cephalosporin biosynthesis. The disrupted mutant accumulates a significant amount of penicillin N, is unable to synthesize deacetoxy-, deacetyl-cephalosporin C and cephalosporin C and shows impaired differentiation into arthrospores. Complementation of the disrupted mutant with the cefM gene restored the intracellular penicillin N concentration to normal levels and allowed synthesis and secretion of the cephalosporin intermediates and cephalosporin C. A fused cefM-gfp gene complemented the cefM-disrupted mutant, and the CefM–GFP (green fluorescent protein) fusion was targeted to intracellular microbodies that were abundant after 72 h of culture in the differentiating hyphae and in the arthrospore chains, coinciding with the phase of intense cephalosporin biosynthesis. Since the dual-component enzyme system CefD1–CefD2 that converts isopenicillin N into penicillin N contains peroxisomal targeting sequences, it is probable that the epimerization step takes place in the peroxisome matrix. The CefM protein seems to be involved in the translocation of penicillin N from the peroxisome (or peroxisome-like microbodies) lumen to the cytosol, where it is converted into cephalosporin C.
Characterization of a phenylacetate–CoA ligase from Penicillium chrysogenum
Authors: Koetsier Martijn J. , Jekel Peter A. , van den Berg Marco A. , Bovenberg Roel A. L. , Janssen Dick B.
Published: October 2008

Enzymatic activation of PAA (phenylacetic acid) to phenylacetyl-CoA is an important step in the biosynthesis of the β-lactam antibiotic penicillin G by the fungus Penicillium chrysogenum. CoA esters of PAA and POA (phenoxyacetic acid) act as acyl donors in the exchange of the aminoadipyl side chain of isopenicillin N to produce penicillin G or penicillin V. The phl gene, encoding a PCL (phenylacetate–CoA ligase), was cloned in Escherichia coli as a maltose-binding protein fusion and the biochemical properties of the enzyme were characterized. The recombinant fusion protein converted PAA into phenylacetyl-CoA in an ATP- and magnesium-dependent reaction. PCL could also activate POA, but the catalytic efficiency of the enzyme was rather low with kcat/Km values of 0.23±0.06 and 7.8±1.2 mM−1·s−1 for PAA and POA respectively. Surprisingly, PCL was very efficient in catalysing the conversion of trans-cinnamic acids to the corresponding CoA thioesters [kcat/Km=(3.1±0.4)×102 mM−1·s−1 for trans-cinnamic acid]. Of all the substrates screened, medium-chain fatty acids, which also occur as the side chains of the natural penicillins F, DF, H and K, were the best substrates for PCL. The high preference for fatty acids could be explained by a homology model of PCL that was constructed on the basis of sequence similarity with the Japanese firefly luciferase. The results suggest that PCL has evolved from a fatty-acid-activating ancestral enzyme that may have been involved in the β-oxidation of fatty acids.
High incidence of DNA mutations and gene amplifications of the ALK gene in advanced sporadic neuroblastoma tumours
Authors: Carén Helena , Abel Frida , Kogner Per , Martinsson Tommy
Published: October 2008

ALK (anaplastic lymphoma kinase) is oncogenic in several tumours and has recently been identified as a predisposition gene for familial NB (neuroblastoma) harbouring mutations in the TKD (tyrosine kinase domain). We have analysed a large set of sporadic human NB primary tumours of all clinical stages for chromosomal re-arrangements using a CGH (comparative genomic hybridization) array (n=108) and mutations of the ALK gene (n=90), and expression of ALK and related genes (n=19). ALK amplification or in-gene re-arrangements were found in 5% of NB tumours and mutations were found in 11%, including two novel not previously published mutations in the TKD, c.3733T>A and c.3735C>A. DNA mutations in the TKD and gene amplifications were only found in advanced large primary tumours or metastatic tumours, and correlated with the expression levels of ALK and downstream genes as well as other unfavourable features, and poor outcome. The results of the present study support that the ALK protein contributes to NB oncogenesis providing a highly interesting putative therapeutic target in a subset of unfavourable NB tumours.
Will You Be My CF Mentor?
Authors: Staub Kenneth J. , McCarthy Mary Pat
Published: October 2008

This article defines “mentor” and “supervisor” as the terms relate to the Issues and Ethics Statement put forth by ASHA in 2007. In addition, the article provides the reader with a rationale for using the term “mentor” instead of “supervisor”, as well as provides a framework for establishing a mentoring relationship during the clinical fellowship experience
Successful Supervisory Training Initiatives in Formative Assessment
Authors: Varnedoe Danielle , Murphree-Holden Crystal , Dixon Sharon
Published: October 2008

Effective training of external practicum site supervisors is a challenge to university training programs. The number of sites and supervisors, distance, time and cost factors all contribute to the need to find efficient methods of providing supervisors with crucial information pertinent to clinical training. The key components to training supervisors on current certification standards and principles of formative assessment learning are the primary focus of this article. Successful methods for providing this information using both traditional formats and technological advances are described in detail. All methods are easily replicable in order to meet the specific training requirements of individual programs in speech-language pathology and audiology.
Identifying and Assisting At-Risk Graduate Students: Process and Outcome Factors
Authors: Schober-Peterson Debra , O’Rourke Colleen M.
Published: October 2008

Graduate students in Communication Disorders may be identified as “at-risk” for a variety of reasons. Challenges to successful completion of a graduate degree include academic difficulty, clinical difficulty, or inappropriate professional behavior. This article will describe the benefits of formative assessment as it relates to working with “at-risk” students and will describe the “at-risk” process used to identify, assist, and track students in the Communication Disorders program at Georgia State University. In addition, the article will provide data regarding the outcome of early identification of student difficulty over a three year period of study. Finally, we provide several observations on situations we have faced and how they have been addressed by our program faculty.
Conflict: Your Role in How It Ends
Authors: Culbertson Deborah
Published: October 2008

Conflict in the workplace is commonplace, yet many health care providers seek to either ignore conflict or confront it in a manner that might lead to personal attacks and/or prevent future collaboration. Health care practitioners and supervisors can learn about the nature of conflict, sources of conflict, and ways to manage and limit conflict. Practitioners and supervisors are jointly responsible for working toward conflict resolution. If effective strategies are used, then conflict can lead to innovative solutions and deepened trust. This article presents information about workplace conflict and strategies for effectively dealing with it.
The Coaching Process in Higher Education
Authors: Koch Carol
Published: October 2008

Excellence in teaching is a standard to which educators aspire. The developmental nature of effective teaching strategies implies the need to provide ongoing and continual support for junior level faculty. Showers (1985) described coaching as a process that involves assistance in learning. Therefore, coaching involves assistance without judgment. Through case study illustration, the coaching process framework will be examined within the context of a university instructor desiring to enhance teaching performance.
A Comparison of Three Teaching Techniques in Anatomy and Physiology
Authors: Carpenter Linda J. , Boh Andrea L.
Published: October 2008

The relative impact on student learning of three active learning strategies was studied. Sixty-three students in an undergraduate anatomy and physiology class used study guides for the respiration section, study guides combined with group quizzes for the phonation section, and study guides combined with student response systems (clickers) for the articulation and resonance section. Learning was measured by administering weekly quizzes, and student satisfaction was evaluated by a survey at the end of the third section of the course. Quiz scores were significantly higher under the clicker condition; students preferred clickers, but found the study guides to be most educationally beneficial. Study guides helped students organize information prior to class; clickers reassured them about what they had learned.
Differentiating ASD From DLD in Toddlers
Authors: Paul Rhea , Chawarska Katyrzyna , Volkmar Fred
Published: October 2008

Failure to begin speaking, or acquiring words and word combinations, is the most common presenting problem in young children. For children with very limited communication skills, it can be difficult to differentiate between children suffering from autism spectrum disorders (ASD) and those with a more circumscribed delay in language development (DLD). This article reviews evidence derived from studies of toddlers who present with poor communication and social skills and summarizes characteristics of early development in these children to assist clinicians in differentiating between ASD and DLD in toddlers.