bluuebunny/crossref_metadata_2025 huggingface dataset:
Tomography of the westernmost Ryukyu subduction zone and the serpentinization of the fore‐arc mantle
Authors: Chou Han‐Chiang , Kuo Ban‐Yuan , Chiao Ling‐Yun , Zhao Dapeng , Hung Shu‐Huei
Published: November 2009

Three‐dimensional tomographic images of the subducting Philippine Sea slab and the fore‐arc mantle beneath NE Taiwan and the westernmost Ryukyu were generated in this study. More than 5600 events recorded simultaneously by seismic networks in Taiwan and Japan were relocated for the inversion for variations in VP, VS, and VP/VS. Analysis of the trade‐off between the data variance reduction and model variance helps to determine the appropriate strictness for regularization to avoid either overinterpretatioin or underinterpretation of data. The regularization parameters were also chosen to ensure suppression of artificial VP/VS anomalies. The subducting slab is characterized by high VP, high VS, and intermediate to low VP/VS. Notable in the mantle wedge is the high VP/VS anomalies that abut the surface of the subducting slab at depths of 30–80 km. The previously identified positive VP/VS channel connecting the slab and the arc volcano interpreted to be a melt pathway is not reproduced in this study. We convert VS and VP/VS to perturbations of temperature and serpentinization of the mantle. The slab is cooled by 200°C–400°C relative to the mantle, in accord with the estimates from theoretical modeling of subduction. The serpentinization reaches ∼15%, or 2% water content, at 50 km depth in the fore‐arc mantle. We interpret the peak serpentinization as hydrated by the water released from the basalt‐eclogite metamorphic reaction in the oceanic crust of the subducting Philippine Sea Plate. The spatial limitation of the present seismic networks in this region with respect to subduction zone events hinders a full description of the pattern of melting in much of the mantle wedge. Resolution tests of the tomographic inversion provide a basis to guide our interpretation to better resolved regions.
Hydrographic conditions along the western Iberian margin during marine isotope stage 2
Authors: Voelker A. H. L. , de Abreu L. , Schönfeld J. , Erlenkeuser H. , Abrantes F.
Published: November 2009

The surface water hydrography along the western Iberian margin, as part of the North Atlantic's eastern boundary upwelling system, consists of a complex, seasonally variable system of equatorward and poleward surface and subsurface currents and seasonal upwelling. Not much information exists to ascertain if the modern current and productivity patterns subsisted under glacial climate conditions, such as during marine isotope stage (MIS) 2, and how North Atlantic meltwater events, especially Heinrich events, affected them. To help answer these questions we are combining stable isotope records of surface to subsurface dwelling planktonic foraminifer species with sea surface temperature and export productivity data for four cores distributed along the western and southwestern Iberian margin (MD95‐2040, MD95‐2041, MD99‐2336, and MD99‐2339). The records reveals that with the exception of the Heinrich events and Greenland Stadial (GS) 4 hydrographic conditions along the western Iberian margin were not much different from the present. During the Last Glacial Maximum (LGM), subtropical surface and subsurface waters penetrated poleward to at least 40.6°N (site MD95‐2040). Export productivity was, in general, high on the western margin during the LGM and low in the central Gulf of Cadiz, in agreement with the modern situation. During the Heinrich events and GS 4, on the other hand, productivity was high in the Gulf of Cadiz and suppressed in the upwelling regions along the western margin where a strong halocline inhibited upwelling. Heinrich event 1 had the strongest impact on the hydrography and productivity off Iberia and was the only period when subarctic surface waters were recorded in the central Gulf of Cadiz. South of Lisbon (39°N), the impact of the other Heinrich events was diminished, and not all of them led to a significant cooling in the surface waters. Thus, climatic impacts of Heinrich events highly varied with latitude and the prevailing hydrographic conditions in this region.
Recent tectonic plate decelerations driven by mantle convection
Authors: Forte A. M. , Moucha R. , Rowley D. B. , Quéré S. , Mitrovica J. X. , Simmons N. A. , Grand S. P.
Published: November 2009

We explore recent changes in tectonic plate velocities using a model of mantle flow that is based on a new high‐resolution global tomography model derived from simultaneous inversions of global seismic, geodynamic and mineral physical data sets. This plate‐coupled mantle convection model incorporates a viscosity structure that reconciles both glacial isostatic adjustment and global convection‐related data sets. The convection model successfully reproduces present‐day plate velocities and global surface gravity and topography constraints. We predict time‐dependent changes in mantle buoyancy that give rise to present‐day decelerations of several major plates, in particular the fast‐moving Pacific and Nazca plates. We verify the plausibility of these predicted plate decelerations using space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions. These plate kinematic constraints are employed to determine a new global map of present‐day plate decelerations that agree well with the mantle flow predictions.
Increased variability of the Arctic summer ice extent in a warmer climate
Authors: Goosse H. , Arzel O. , Bitz C. M. , de Montety A. , Vancoppenolle M.
Published: November 2009

Simulations performed with general circulation models and a model of intermediate complexity show that the variability of the September sea ice extent in the Arctic of the 21st century increases first when the mean extent decreases from present‐day values. A maximum of the variance is found when the mean September ice extent is around 3 million km2. For lower extents, the variance declines with the mean extent. The behavior is clearly different in Antarctica where the variance always decreases as the mean ice extent decreases, following roughly a square‐root law compatible with very simple geometric arguments. Several mechanisms are responsible for the non‐linear behavior of the Arctic. However, the strong interhemispheric contrast suggests that the difference in geometrical setting, with an open ocean in the south and a semi‐closed basin in the north, plays a significant role.
Effects of gouge fragment shape on fault friction: New 3D modelling results
Authors: Abe Steffen , Mair Karen
Published: November 2009

The friction of granular fault gouge plays an important role in governing the mechanical behavior and hence earthquake potential of faults. Using numerical modelling, significant progress has recently been made towards understanding the micro‐mechanics that drive fault gouge evolution. Despite these insights, many previous numerical models have predicted unrealistically low macroscopic frictional strength. Here we describe modified 3D discrete element simulations of fault gouge evolution. Our particle‐based simulations, modelled on laboratory experiments, include breakable bonds between individual particles (or particle clusters) allowing fracture of aggregate grains. With accumulated strain, grains break up, evolving in size and shape to produce a textural signature reminiscent of natural faults. Cluster‐simulations, producing pseudo‐angular daughter fragments yield realistic frictional strength (0.6). Non‐cluster simulations, producing angular and spherical daughter fragments, have much lower friction levels. We therefore demonstrate that gouge fragment shape and resulting interactions dominate the frictional strength of faults.
Relative increase of record high maximum temperatures compared to record low minimum temperatures in the U.S.
Authors: Meehl Gerald A. , Tebaldi Claudia , Walton Guy , Easterling David , McDaniel Larry
Published: November 2009

The current observed value of the ratio of daily record high maximum temperatures to record low minimum temperatures averaged across the U.S. is about two to one. This is because records that were declining uniformly earlier in the 20th century following a decay proportional to 1/n (n being the number of years since the beginning of record keeping) have been declining less slowly for record highs than record lows since the late 1970s. Model simulations of U.S. 20th century climate show a greater ratio of about four to one due to more uniform warming across the U.S. than in observations. Following an A1B emission scenario for the 21st century, the U.S. ratio of record high maximum to record low minimum temperatures is projected to continue to increase, with ratios of about 20 to 1 by mid‐century, and roughly 50 to 1 by the end of the century.
Sensitivity of stable water isotopic values to convective parameterization schemes
Authors: Lee Jung‐Eun , Pierrehumbert Raymond , Swann Abigail , Lintner Benjamin R.
Published: November 2009

Convective parameterization has been argued as a principal generator of inter‐model differences in climate sensitivity, but it is difficult in practice to constrain simulated convective processes. Here we show how stable water vapor isotopes, which are sensitive to the convective condensation rates, may be useful for evaluating convective parameterizations. By varying one of the least constrained convection parameters in the NCAR Community Atmosphere Model (CAM), namely the timescale for consumption of convective available potential energy (CAPE), τ, the simulated precipitation experiences substantial changes in response to changes in both the deep and shallow convection schemes—increasing τ from the standard 2 hours to 8 hours increases the contribution from shallow convection. The lowest order effect of increasing τ is a decrease (increase) in lower (upper) tropospheric condensation rates, with approximately the opposite vertical structure for the change in simulated isotopic signature. Increasing τ from the standard 2 hours to 8 hours also provides a better match to satellite‐observed water vapor isotope ratios, albeit with some uncertainty related to the quality of currently‐available satellite measurements. Thus, the incorporation of water vapor isotopes into GCMs provides additional constraints on convective parameterizations, especially as more and better quality water vapor isotope measurements become available.
Asian anthropogenic emissions and decadal trends in springtime tropospheric ozone over Japan: 1998–2007
Authors: Tanimoto Hiroshi , Ohara Toshimasa , Uno Itsuhi
Published: November 2009

We examine springtime ozone trends at nine remote locations in Japan during the last decade. The observed decadal ozone trends are relatively small at surface sites but are substantially larger at a mountainous site. We use a regional chemistry‐transport model to explore the observed changes and how changes in Asian anthropogenic emissions have contributed to the observed increasing trends. The model with yearly‐dependent regional emissions successfully reproduces the levels, variability, and interannual variations of ozone at all the surface sites. It predicts increasing trends at the mountainous site, suggesting that increasing Asian anthropogenic emissions account for about half the observed increase. However, the discrepancy between the observation and model results after 2003 (the time of largest emission increase) suggests significant underestimation of the actual growth of the Asian anthropogenic emissions and/or incompleteness in the modeling of pollution export from continental Asia.
Temporal evolution of proton precipitation associated with the plasmaspheric plume
Authors: Spasojevic M. , Fuselier S. A.
Published: November 2009

The temporal evolution of afternoon sector proton precipitation observed by a global auroral imager is examined in detail for two case events. We focus on precipitation regions that are magnetically mapped to the plasmapause and plasmaspheric plume regions. The spatial and temporal variation of the plume‐associated precipitation, including its relationship to the main proton oval, is dependent on the prevailing solar wind and magnetospheric driving conditions. Two contrasting events are presented here in association with 1) a substorm injection and 2) a northward IMF turning. We find that proton precipitation within the plasmaspheric plume is a persistent feature during geomagnetically disturbed periods, but the precipitation regions only appear latitudinally detached from the main proton oval under specific conditions. The evolution in both time and space of the plume‐associated precipitation regions is consistent with theoretical predictions for EMIC wave scattering of protons in the ring current energy range.
Cochlear Implants: How “Team Work” Can Take the “Guess Work” Out of Patient Care
Authors: Lal Avanti , Simek Stacy , Still Jennifer , Weber Lisa
Published: November 2009

The Children's Memorial Hospital cochlear implant team believes an interdisciplinary approach is essential for the implementation of best practices when working with the pediatric cochlear implant population. Over time, we have developed a team model that builds relationships with members of the community to ensure comprehensive care for patients and their families.
Where Are the Voices of Adolescents? An Examination of Adolescent Cochlear Implant Users' Socio-Emotional Development
Authors: Neria Christy M.
Published: November 2009

The advancement of cochlear implant technology has led researchers to focus on its functionality, rather than the socio-emotional effects cochlear implants may have on young recipients. This paper will examine recent research on social-emotional development of cochlear implant recipients while discussing the importance of exploring the social emotional responses of adolescents with cochlear implants.
Frauke Melchior: How SUMO wrestles other proteins
Authors: Sedwick Caitlin
Published: November 2009

Melchior's laboratory is exploring the regulation and consequences of protein modification by the small protein SUMO.
Decreased replication origin activity in temporal transition regions
Authors: Guan Zeqiang , Hughes Christina M. , Kosiyatrakul Settapong , Norio Paolo , Sen Ranjan , Fiering Steven , Allis C. David , Bouhassira Eric E. , Schildkraut Carl L.
Published: November 2009

In the mammalian genome, early- and late-replicating domains are often separated by temporal transition regions (TTRs) with novel properties and unknown functions. We identified a TTR in the mouse immunoglobulin heavy chain (Igh) locus, which contains replication origins that are silent in embryonic stem cells but activated during B cell development. To investigate which factors contribute to origin activation during B cell development, we systematically modified the genetic and epigenetic status of the endogenous Igh TTR and used a single-molecule approach to analyze DNA replication. Introduction of a transcription unit into the Igh TTR, activation of gene transcription, and enhancement of local histone modifications characteristic of active chromatin did not lead to origin activation. Moreover, very few replication initiation events were observed when two ectopic replication origin sequences were inserted into the TTR. These findings indicate that the Igh TTR represents a repressive compartment that inhibits replication initiation, thus maintaining the boundaries between early and late replication domains.
Ube2j2 ubiquitinates hydroxylated amino acids on ER-associated degradation substrates
Authors: Wang Xiaoli , Herr Roger A. , Rabelink Martijn , Hoeben Rob C. , Wiertz Emmanuel J.H.J. , Hansen Ted H.
Published: November 2009

Ubiquitin (Ub) modification of proteins plays a prominent role in the regulation of multiple cell processes, including endoplasmic reticulum–associated degradation (ERAD). Until recently, ubiquitination of substrates was thought to occur only via isopeptide bonds, typically to lysine residues. Several recent studies suggest that Ub can also be coupled to nonlysine residues by ester/thiolester bonds; however, the molecular basis for these novel modifications remains elusive. To probe the mechanism and importance of nonlysine ubiquitination, we have studied the viral ligase murine K3 (mK3), which facilitates the polyubiquitination of hydroxylated amino acids serine/threonine on its ERAD substrate. In this paper, we identify Ube2j2 as the primary cellular E2 recruited by the mK3 ligase, and this E2–E3 pair is capable of conjugating Ub on lysine or serine residues of substrates. However, surprisingly, Ube2j2–mK3 preferentially promotes ubiquitination of hydroxylated amino acids via ester bonds even when lysine residues are present on wild-type substrates, thus establishing physiological relevance of this novel ubiquitination strategy.
An electrostatic switch displaces phosphatidylinositol phosphate kinases from the membrane during phagocytosis
Authors: Fairn Gregory D. , Ogata Koji , Botelho Roberto J. , Stahl Philip D. , Anderson Richard A. , De Camilli Pietro , Meyer Tobias , Wodak Shoshana , Grinstein Sergio
Published: November 2009

Plasmalemmal phosphatidylinositol (PI) 4,5-bisphosphate (PI4,5P2) synthesized by PI 4-phosphate (PI4P) 5-kinase (PIP5K) is key to the polymerization of actin that drives chemotaxis and phagocytosis. We investigated the means whereby PIP5K is targeted to the membrane and its fate during phagosome formation. Homology modeling revealed that all PIP5K isoforms feature a positively charged face. Together with the substrate-binding loop, this polycationic surface is proposed to constitute a coincidence detector that targets PIP5Ks to the plasmalemma. Accordingly, manipulation of the surface charge displaced PIP5Ks from the plasma membrane. During particle engulfment, PIP5Ks detached from forming phagosomes as the surface charge at these sites decreased. Precluding the change in surface charge caused the PIP5Ks to remain associated with the phagosomal cup. Chemically induced retention of PIP5K-γ prevented the disappearance of PI4,5P2 and aborted phagosome formation. We conclude that a bistable electrostatic switch mechanism regulates the association/dissociation of PIP5Ks from the membrane during phagocytosis and likely other processes.
On oscillating flows in randomly heterogeneous porous media
Authors: Trefry M. G. , McLaughlin D. , Metcalfe G. , Lester D. , Ord A. , Regenauer-Lieb K. , Hobbs B. E.
Published: November 2009

The emergence of structure in reactive geofluid systems is of current interest. In geofluid systems, the fluids are supported by a porous medium whose physical and chemical properties may vary in space and time, sometimes sharply, and which may also evolve in reaction with the local fluids. Geofluids may also experience pressure and temperature conditions within the porous medium that drive their momentum relations beyond the normal Darcy regime. Furthermore, natural geofluid systems may experience forcings that are periodic in nature, or at least episodic. The combination of transient forcing, near-critical fluid dynamics and heterogeneous porous media yields a rich array of emergent geofluid phenomena that are only now beginning to be understood. One of the barriers to forward analysis in these geofluid systems is the problem of data scarcity. It is most often the case that fluid properties are reasonably well known, but that data on porous medium properties are measured with much less precision and spatial density. It is common to seek to perform an estimation of the porous medium properties by an inverse approach, that is, by expressing porous medium properties in terms of observed fluid characteristics. In this paper, we move toward such an inversion for the case of a generalized geofluid momentum equation in the context of time-periodic boundary conditions. We show that the generalized momentum equation results in frequency-domain responses that are governed by a second-order equation which is amenable to numerical solution. A stochastic perturbation approach demonstrates that frequency-domain responses of the fluids migrating in heterogeneous domains have spatial spectral densities that can be expressed in terms of the spectral densities of porous media properties.
A study of localization limiters and mesh dependency in earthquake rupture
Authors: Olsen-Kettle Louise , Mühlhaus Hans , Baillard Christian
Published: November 2009

No complete physically consistent model of earthquake rupture exists that can fully describe the rich hierarchy of scale dependencies and nonlinearities associated with earthquakes. We study mesh sensitivity in numerical models of earthquake rupture and demonstrate that this mesh sensitivity may provide hidden clues to the underlying physics generating the rich dynamics associated with earthquake rupture. We focus on unstable slip events that occur in earthquakes when rupture is associated with frictional weakening of the fault. Attempts to simulate these phenomena directly by introducing the relevant constitutive behaviour leads to mesh-dependent results, where the deformation localizes in one element, irrespective of size. Interestingly, earthquake models with oversized mesh elements that are ill-posed in the continuum limit display more complex and realistic physics. Until now, the mesh-dependency problem has been regarded as a red herring—but have we overlooked an important clue arising from the mesh sensitivity? We analyse spatial discretization errors introduced into models with oversized meshes to show how the governing equations may change because of these error terms and give rise to more interesting physics.
Forecasting: it is not about statistics, it is about dynamics
Authors: Judd Kevin , Stemler Thomas
Published: November 2009

In 1963, the mathematician and meteorologist Edward Lorenz published a paper (Lorenz 1963
J. Atmos. Sci.
20
, 130–141) that changed the way scientists think about the prediction of geophysical systems, by introducing the ideas of chaos, attractors, sensitivity to initial conditions and the limitations to forecasting nonlinear systems. Three years earlier, the mathematician and engineer Rudolf Kalman had published a paper (Kalman 1960
Trans. ASME Ser. D, J. Basic Eng.
82
, 35–45) that changed the way engineers thought about prediction of electronic and mechanical systems. Ironically, in recent years, geophysicists have become increasingly interested in Kalman filters, whereas engineers have become increasingly interested in chaos. It is argued that more often than not the tracking and forecasting of nonlinear systems has more to do with the nonlinear dynamics that Lorenz considered than it has to do with statistics that Kalman considered. A position with which both Lorenz and Kalman would appear to agree.
A partially open porous media flow with chaotic advection: towards a model of coupled fields
Authors: Metcalfe Guy , Lester Daniel , Ord Alison , Kulkarni Pandurang , Trefry Mike , Hobbs Bruce E. , Regenaur-Lieb Klaus , Morris Jeffery
Published: November 2009

In nature, dissipative fluxes of fluid, heat and/or reacting species couple to each other and may also couple to deformation of a surrounding porous matrix. We use the well-known analogy of Hele–Shaw flow to Darcy flow to make a model porous medium with porosity proportional to local cell height. Time- and space-varying fluid injection from multiple source/sink wells lets us create many different kinds of chaotic flows and chemical concentration patterns. Results of an initial time-dependent potential flow model illustrate that this is a partially open flow, in which parts of the material transported by the flow remain in the cell forever and parts pass through with residence time and exit time distributions that have self-similar features in the control parameter space of the stirring. We derive analytically the existence boundary in stirring control parameter space between where isolated fluid regions can and cannot remain forever in the open flow. Experiments confirm the predictions.
The spatial and temporal patterning of the deep crust and implications for the process of melt extraction
Authors: Brown Michael
Published: November 2009

Volumetrically significant melt production requires crustal temperatures above approximately 800°C. At the grain scale, the former presence of melt may be inferred based on various microstructures, particularly pseudomorphs of melt pores and grain-boundary melt films. In residual migmatites and granulites, evidence of melt-extraction pathways at outcrop scale is recorded by crystallized products of melt (leucosome) and residual material from which melt has drained (melanosome). These features form networks or arrays that potentially demonstrate the temporal and spatial relations between deformation and melting. As melt volume increases at sites of initial melting, the feedback between deformation and melting creates a dynamic rheological environment owing to localization and strain-rate weakening. With increasing temperature, melt volume increases to the melt connectivity transition, in the range of 2–7 vol% melt, at which point melt may escape in the first of several melt-loss events, where each event represents a batch of melt that left the source and ascended higher in the crust. Each contributing process has characteristic length and time scales, and it is the nonlinear interactions and feedback relations among them that give rise to the dissipative structures and episodicity of melt-extraction events that are recorded as variations in the spatial and temporal patterning of the crust. Focused melt flow occurs by dilatant shear failure of low-melt fraction rocks creating melt-flow networks that allow accumulation and storage of melt, and form the link for melt flow from grain boundaries to veins allowing drainage to crustal-scale ascent conduits. Preliminary indications suggest that anatectic systems are strongly self-organized from the bottom up, becoming more ordered by decreasing the number and increasing the width of ascent conduits from the anatectic zone through the overlying subsolidus crust to the ductile-to-brittle transition zone, where the melt accumulates in plutons.
Time-dependent, irreversible entropy production and geodynamics
Authors: Regenauer-Lieb Klaus , Karrech Ali , Chua Hui Tong , Horowitz Franklin G. , Yuen Dave
Published: November 2009

We present an application of entropy production as an abstraction tool for complex processes in geodynamics. Geodynamic theories are generally based on the principle of maximum dissipation being equivalent to the maximum entropy production. This represents a restriction of the second law of thermodynamics to its upper bound. In this paper, starting from the equation of motion, the first law of thermodynamics and decomposition of the entropy into reversible and irreversible terms,

1

we come up with an entropy balance equation in an integral form. We propose that the extrema of this equation give upper and lower bounds that can be used to constrain geodynamics solutions. This procedure represents an extension of the classical limit analysis theory of continuum mechanics, which considers only stress and strain rates. The new approach, however, extends the analysis to temperature-dependent problems where thermal feedbacks can play a significant role. We apply the proposed procedure to a simple convective/conductive heat transfer problem such as in a planetary system. The results show that it is not necessary to have a detailed knowledge of the material parameters inside the planet to derive upper and lower bounds for self-driven heat transfer processes. The analysis can be refined by considering precise dissipation processes such as plasticity and viscous creep.
Entropy production and self-organized (sub)criticality in earthquake dynamics
Authors: Main Ian G. , Naylor Mark
Published: November 2009

We derive an analytical expression for entropy production in earthquake populations based on Dewar’s formulation, including flux (tectonic forcing) and source (earthquake population) terms, and apply it to the Olami–Feder–Christensen numerical model for earthquake dynamics. Assuming the commonly observed power-law rheology between driving stress and remote strain rate, we test the hypothesis that maximum entropy production (MEP) is a thermodynamic driver for self-organized ‘criticality’ (SOC) in the model. MEP occurs when the global elastic strain is near-critical, with small relative fluctuations in macroscopic strain energy expressed by a low seismic efficiency, and broad-bandwidth power-law scaling of frequency and rupture area. These phenomena, all as observed in natural earthquake populations, are hallmarks of the broad conceptual definition of SOC (which has, to date, often included self-organizing systems in a near but strictly subcritical state). In the MEP state, the strain field retains some memory of past events, expressed as coherent ‘domains’, implying a degree of predictability, albeit strongly limited in practice by the proximity to criticality and our inability to map the natural stress field at an equivalent resolution to the numerical model.
Determination of the molecular weight of proteins in solution from a single small-angle X-ray scattering measurement on a relative scale
Authors: Fischer H. , de Oliveira Neto M. , Napolitano H. B. , Polikarpov I. , Craievich A. F.
Published: November 2009

This paper describes a new and simple method to determine the molecular weight of proteins in dilute solution, with an error smaller than ∼10%, by using the experimental data of a single small-angle X-ray scattering (SAXS) curve measured on a relative scale. This procedure does not require the measurement of SAXS intensity on an absolute scale and does not involve a comparison with another SAXS curve determined from a known standard protein. The proposed procedure can be applied to monodisperse systems of proteins in dilute solution, either in monomeric or multimeric state, and it has been successfully tested on SAXS data experimentally determined for proteins with known molecular weights. It is shown here that the molecular weights determined by this procedure deviate from the known values by less than 10% in each case and the average error for the test set of 21 proteins was 5.3%. Importantly, this method allows for an unambiguous determination of the multimeric state of proteins with known molecular weights.
EVAL15: a diffraction data integration method based onab initiopredicted profiles
Authors: Schreurs Antoine M. M. , Xian Xinyi , Kroon-Batenburg Loes M. J.
Published: November 2009

A novel diffraction data integration method is presented,EVAL15, based uponab initiocalculation of three-dimensional (x,y, ω) reflection profiles from a few physical crystal and instrument parameters. Net intensities are obtained by least-squares fitting the observed profile with the calculated standard using singular value decomposition. This paper shows that profiles can be predicted satisfactorily and that accurate intensities are obtained. The detailed profile analysis has the additional advantage that specific physical properties of the crystal are revealed. TheEVAL15method is particularly useful in circumstances where other programs fail, such as regions of reciprocal space with weak scattering, crystals with anisotropic shape or anisotropic mosaicity,Kα1/Kα2peak splitting, interference from close neighbours, twin lattices, or satellite reflections of modulated structures, all of which may frustrate the customary profile learning and fitting procedures.EVAL15allows the deconvolution of overlapping reflections.
In-situsmall-angle neutron scattering study of pore filling and pore emptying in ordered mesoporous silica
Authors: Erko M. , Wallacher D. , Brandt A. , Paris O.
Published: November 2009

The capillary condensation and capillary emptying of water and perfluoropentane in ordered mesoporous SBA-15 silica is studied byin-situsmall-angle neutron scattering (SANS). The SANS data can be perfectly described by a simple analytical model for spatially random pore filling (Laue scattering) for the entire range of pore-filling fractions. From this it is concluded that recently proposed pore correlations due to elastic interactions between neighbouring pores upon capillary condensation do not play a role in this system. The pores fill randomly according to their size distribution, in perfect agreement with the classical Kelvin equation. The relation between the overall pore-filling fraction as determined from the volumetric sorption isotherm, and the fraction of completely filled pores as obtained from the fit of the SANS data, allows conclusions to be drawn about the thermodynamic metastability of the adsorption process.
xia2: an expert system for macromolecular crystallography data reduction
Authors: Winter G.
Published: November 2009

An expert system for macromolecular crystallography data reduction is presented, which builds on existing software to automate the complete data reduction process from images to merged structure factor amplitudes. This can automatically identify multi-wedge, multi-pass and multiwavelength data sets and includes explicit procedures to test for crystallographic special cases. With the push towards high-thoughput crystallography at synchrotron beamlines and automation of structure solution, the ability to reduce data with no user input fills an important gap in the pipeline.
Multipotent adult progenitor cell isolation and proliferation in cytokine and serum‐free medium conditioned by rat B104 cells
Authors: Rice Claire M. , Clavel Carlos , Mazo Manu , Prosper Felipe , Scolding Neil J.
Published: November 2009

This report describes the isolation of rodent multipotent adult progenitor cells (MAPCs) and proliferation of these cells in both standard medium and medium without exogenous serum or growth factors conditioned by the rat cell line B104. MAPCs have exacting requirements for their proliferation in vitro but once established proliferate rapidly at low seeding density, requiring almost daily passage and media exchange. Previously published methods for growth of MAPCs in vitro all used media supplemented with serum and growth factors, which adds considerable expense.
Birth defects in the sons and daughters of women who were exposed in utero to diethylstilbestrol (DES)
Authors: Titus‐Ernstoff L. , Troisi R. , Hatch E. E. , Palmer J. R. , Hyer M. , Kaufman R. , Adam E. , Noller K. , Hoover R. N.
Published: November 2009

Prenatal exposure to diethylstilbestrol (DES) is associated with adverse health outcomes, including anatomic anomalies of the reproductive tract in women and of the genitourinary tract in men. The mouse model, which replicates many DES‐related effects seen in humans, suggests that prenatal DES exposure causes alterations that may affect the next generation of offspring.

We asked women participating in a large, multi‐centre study of prenatal DES exposure to report birth defects occurring among 4029 sons and 3808 daughters (i.e., the third generation). A subcohort of 793 third generation daughters was also queried for birth defects. We used logistic regression models to generate odds ratio and 95% confidence intervals for the association between prenatal DES exposure in the mother and birth defects in the offspring.

Based on the mothers’ reports, overall birth defects were elevated in the sons (OR = 1.53; 95% CI = 1.04, 2.23) and in the daughters (OR = 2.35; 95% CI = 1.44, 3.82). Most estimates of association were imprecise, but daughters appeared to have an excess of heart conditions (OR = 4.56; 95% CI = 1.27, 16.34).

Our data suggest a possible association between the mother’s prenatal DES exposure and birth defects in their offspring, particularly in daughters. We cannot, however, rule‐out the possible influence of reporting bias. In particular, the exposed daughters’ elevated risk of cardiac defects may be as a result of the underreporting of these conditions by unexposed mothers.
Urinary bisphenol A concentrations and ovarian response among women undergoing IVF
Authors: Mok‐Lin E. , Ehrlich S. , Williams P. L. , Petrozza J. , Wright D. L. , Calafat A. M. , Ye X. , Hauser R.
Published: November 2009

Bisphenol A (BPA) is a synthetic chemical used in the manufacture of materials present in many common consumer products. In experimental animals, BPA caused oocyte aneuploidy and reduced production of oestradiol. In a prospective cohort study, we investigated the association between urinary BPA concentrations and ovarian response among women undergoing in vitro fertilization (IVF) at the Massachusetts General Hospital (MGH) Fertility Center. The geometric mean of two specific‐gravity (SG) adjusted urinary BPA concentrations collected during each IVF cycle was used as the cycle‐specific BPA exposure level. BPA concentrations were measured using online solid phase extraction coupled to isotope dilution‐high‐performance liquid chromatography‐tandem mass spectrometry. Peak serum oestradiol was measured using the Elecsys Estradiol II immunoassay kit. Multivariable mixed effect models and Poisson regression models adjusting for correlation between multiple IVF cycles in the same woman were used to evaluate the association between urinary BPA concentrations and ovarian response, adjusting for age, BMI and day 3 follicle stimulating hormone (FSH) levels, a clinical measure of ovarian reserve. Urinary BPA concentrations were measured in 84 women (mean age 35.6 years) undergoing 112 IVF cycles; 23 women (27%) contributed more than one IVF cycle. BPA concentrations ranged from <0.4 to 25.5 μg/L (geometric mean 2.52 ± SD 3.2); 15% of urine samples had concentrations <0.4 μg/L. Peak serum oestradiol levels correlated with the total number of oocytes retrieved per cycle (r = 0.65, p < 0.001). For each log unit increase in SG‐BPA, there was an average decrease of 12% (95% CI: 4, 23%; p = 0.007) in the number of oocytes retrieved and an average decrease of 213 pg/ml (95% CI: −407, −20; p = 0.03) in peak oestradiol. BPA was detected in the urine of the majority of women undergoing IVF, and was inversely associated with number of oocytes retrieved and peak oestradiol levels.
Micro‐adaptivity: protecting immersion in didactically adaptive digital educational games
Authors: Kickmeier‐Rust M.D. , Albert D.
Published: November 2009

The idea of utilizing the rich potential of today's computer games for educational purposes excites educators, scientists and technicians. Despite the significant hype over digital game‐based learning, the genre is currently at an early stage. One of the most significant challenges for research and development in this area is establishing intelligent mechanisms to support and guide the learner, and to realize a subtle balance between learning and gaming, and between challenge and ability on an individual basis. In contrast to traditional approaches of adaptive and intelligent tutoring, the key advantage of games is their immersive and motivational potential. Because of this, the psycho‐pedagogical and didactic measures must not compromise gaming experience, immersion and flow. In the present paper, we introduce the concept of micro‐adaptivity, an approach that enables an educational game to intelligently monitor and interpret the learner's behaviour in the game's virtual world in a non‐invasive manner. On this basis, micro‐adaptivity enables interventions, support, guidance or feedback in a meaningful, personalized way that is embedded in the game's flow. The presented approach was developed in the context of the European Enhanced Learning Experience and Knowledge TRAnsfer project. This project also realized a prototype game, demonstrating the capabilities, strengths and weaknesses of micro‐adaptivity.
How to determine the susceptibility of Meligethes aeneus to neonicotinoids?
Authors: Thieme T. , Gloyna K. , Drbal U. , Zellner M.
Published: November 2009

Three different bioassays were used to determine the susceptibility to the neonicotinoid Biscaya® of oilseed rape pollen beetles collected from fields in Bavaria. The one in which the test substance was applied to the inner wall of glass tubes is recommended for future studies on pollen beetles because it is not dependent on the availability of plant material and provides precise information on the amount of insecticide required per unit area.
Insecticidal activities of essential oil of Callistemon viminalis applied as fumigant and powder against two bruchids
Authors: Ndomo A. F. , Tapondjou L. A. , Ngamo L. T. , Hance T.
Published: November 2009

The fumigant and contact toxicity of essential oil (EO) extracted from the leaves of Callistemon viminalis and its aromatized clay powder (ACP) was evaluated against adults of Acanthoscelides obtectus and Callosobruchus maculatus (Coleoptera: Bruchidae). The results obtained for fumigation assays showed that C. maculatus seems to be more susceptible (LC50 = 0.019 μl/cm3) to the vapours of the essential oil than A. obtectus (LC50 = 0.011 μl/cm3) after 12 h exposure. On the other hand, A. obtectus seems to be more susceptible (LD50 = 0.133 μl/g) to the essential oil applied by contact on grains than C. maculatus (LD50 = 0.170 μl/g) after 2 days exposure. The ACP was also very toxic towards the adults of A. obtectus (LD50 = 0.100 μl/g) and C. maculatus (LD50 = 0.098 μl/g) by contact on grains. At the doses of 0.133 μl/g and 0.266 μl/g, mortalities caused by ACP on grains were higher than those caused by the same dose of EO against the two bruchids. It is also established that both the EO and the ACP caused higher inhibition of F1 progeny production of A. obtectus than that of C. maculatus. The loss of insecticidal activity of the two materials in the course of time has been observed; however, the toxicity of the ACP was more persistent than that of the oil in the course of time when applied on grains. These results suggest that EO from the leaves of C. viminalis can be used as fumigant agent against A. obtectus and C. maculatus. In addition, it could be advisable to use an adsorbent mineral material as carrier of this EO for the prolongation of its insecticidal activity in the course of time.
Haemolymph defence of an invasive herbivore: its breadth of effectiveness against predators
Authors: Lundgren J. G. , Toepfer S. , Haye T. , Kuhlmann U.
Published: November 2009

Defensive characteristics of organisms affect the trophic linkages within food webs and influence the ability of invasive species to expand their range. Diabrotica v. virgifera is one such invasive herbivore whose predator community is restricted by a larval haemolymph defence. The effectiveness of this haemolymph defence against a range of predator functional and taxonomic guilds from the recipient biota was evaluated in a series of experiments. Eight predator species (Carabidae, Lycosidae, Formicidae) were fed D. v. virgifera 3rd instars or equivalent‐sized maggots in the laboratory, and the mean times spent eating, cleaning their mouthparts, resting and walking following attacks on each prey were compared. Prey species were restrained in five Hungarian maize fields for 1 h periods beginning at 09:00 and 22:00 hours. The proportion of each species attacked and the number and identity of predators consuming each prey item were recorded. All predators spent less time eating D. v. virgifera larvae than maggots in the laboratory, and four of the eight predator species spent more time cleaning their mouthparts. The differential responses in the predator species indicate differences in susceptibility to the D. v. virgifera haemolymph defence. The predator communities (numerically dominated by Tetramorium caespitum) in the field showed clear diel patterns in their foraging behaviour, and D. v. virgifera was consumed by fewer predators than maggots. The defence of D. v. virgifera may partly explain how invasive insects that are exposed to an extensive predator community overcome biotic resistance to the invasion process.
Comparison of sampling tabanids (Diptera: Tabanidae) by four different potential attractants
Authors: Krčmar S. , Mikuška A. , Radolić V.
Published: November 2009

Synthetic and natural attractants in traps are used in many parts of the world to attract female tabanids. Certain attractants in different geographic regions may be ineffective or effective under different environmental conditions for horseflies. One‐octen‐3‐ol, as a compound present in bovine emanations, has a behavioural effect on many horsefly species and together with other phenolic compounds makes very effective attractant for this group of insects. As the attractiveness of the mixture of three chemicals (1‐octen‐3‐ol, acetone and ammonia solution in the proportions 5 : 3 : 2), aged donkey urine, lactic acid and fresh human urine is not yet known, it was studied in Eastern Croatia. The combination of those three chemicals and efficiency of natural attractants offers promising results.Tabanuswas the most represented genus with 83% of the total collected tabanids. The chi‐squared analyses of the trapping data for canopy traps revealed that each of the attractants (mixture of three chemicals, aged donkey urine, lactic acid and fresh human urine) significantly increased the number of collected horseflies in comparison to those collected in unbaited canopy traps. Some species differences in relative response to different attractants were noted. Significantly, more specimens ofHaematopota pluvialiswere collected from canopy traps baited with the mixture of three chemicals when compared with traps baited with other attractants. Canopy traps baited with aged donkey urine collected significantly moreAtylotus loewianusfemales than did traps baited with the mixture. The F‐test analysis of the trapping data for the genusTabanusshowed that there is significant difference between average number of collected specimens between mixture of three chemicals and other used attractants (lactic acid and human urine) except aged donkey urine. Finally, traps baited with the mixture of three chemicals (1‐octen‐3‐ol, acetone and ammonia solution) collected 14.5 times more tabanids than unbaited traps, whereas aged donkey urine, lactic acid, and fresh human urine‐baited traps collected 12, 3.9 and 2.5 times as many tabanids, respectively, than did unbaited traps. The mixture of three chemicals (1‐octen‐3‐ol, acetone and ammonia solution) and aged donkey urine appear to be very effective attractants for tabanids.