bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vanadyl(IV) complexes with saccharides. Bioactivity in osteoblast-like cells in cultureThis paper is one of a selection of papers published in this Special issue, enititled Second Messengers and Phosphoproteins—12th International Conference.
Authors: Barrio Daniel A. , Cattáneo Elizabeth R. , Apezteguía María C. , Etcheverry Susana B. 
Published: September 2006

Complexes of vanadyl(IV) with 4 monosaccharides and 5 disaccharides were tested in 2 osteoblast-like cell lines (MC3T3E1 and UMR106). Many complexes caused stimulation of UMR106 proliferation (120% basal) in the range of 2.5 to 25 µmol/L. In the nontransformed osteoblasts, some vanadyl–saccharide complexes stimulated the mitogenesis (115% basal) in the same range of concentration. The glucose and sucrose complexes were the most efficient inhibitory agents (65% and 88% of inhibition vs. basal, respectively) for tumoral cells at 100 µmol/L. The galactose and turanose complexes exerted a similar effect in the nontransformed osteoblasts. On the other hand, all the complexes promoted the phosphorylation of the extracellular regulated kinases (ERKs). All together, these results indicate that the stimulation of ERKs is not the only factor that plays a role in the proliferative effects of vanadium derivatives since some compounds were inhibitory proliferating agents. Cell differentiation was evaluated by alkaline phosphatase specific activity and collagen synthesis in UMR106 cells. All the complexes inhibited alkaline phosphatase activity, with galactose complex as the most effective compound (IC50= 43 µmol/L). The complex with the trehalose TreVO was the most effective agent to stimulate collagen synthesis (142% basal) and glucose consumption (132% basal). A cytosolic tyrosine protein kinase and the kinase-3 of glycogen synthase seem to be involved in the stimulation of glucose consumption by vanadium derivatives. In this series, only TreVO gathered the characteristics of a good insulin mimetic and osteogenic drug. In addition, this complex was a good promoting agent of nontransformed osteoblast proliferation, whereas it inhibited tumoral osteoblasts. GluVO, the complex with glucose, was also more toxic for tumoral than for nontransformed cells. These 2 vanadium derivatives are good potential antitumoral drugs. All the results suggest that the biological effects of vanadium compounds are a complex phenomenon influenced by the complexation, the dose, and the nature of the ligands and the cells.
Activation of Preexisting and Acquired Face Representations: The N250 Event-related Potential as an Index of Face Familiarity
Authors: Tanaka James W. , Curran Tim , Porterfield Albert L. , Collins Daniel 
Published: September 2006

Abstract
Electrophysiological studies using event-related potentials have demonstrated that face stimuli elicit a greater negative brain potential in right posterior recording sites 170 msec after stimulus onset (N170) relative to nonface stimuli. Results from repetition priming paradigms have shown that repeated exposures of familiar faces elicit a larger negative brainwave (N250r) at inferior temporal sites compared to repetitions of unfamiliar faces. However, less is known about the time course and learning conditions under which the N250 face representation is acquired. In the familiarization phase of the Joe/no Joe task, subjects studied a target “Joe” face (“Jane” for female subjects) and, during the course of the experiment, identified a series of sequentially presented faces as either Joe or not Joe. The critical stimulus conditions included the subject's own face, a same-sex Joe ( Jane) face and a same-sex “other” face. The main finding was that the subject's own face produced a focal negative deflection (N250) in posterior channels relative to nontarget faces. The task-relevant Joe target face was not differentiated from other nontarget faces in the first half of the experiment. However, in the second half, the Joe face produced an N250 response that was similar in magnitude to the own face. These findings suggest that the N250 indexes two types of face memories: a preexperimentally familiar face representation (i.e., the “own face” and a newly acquired face representation (i.e., the Joe/Jane face) that was formed during the course of the experiment.
Contribution of Familiarity and Recollection to Associative Recognition Memory: Insights from Event-related Potentials
Authors: Opitz Bertram , Cornell Sonia 
Published: September 2006

Abstract
Within the dual-process perspective of recognition memory, it has been claimed that familiarity is sufficient to support recognition of single items, but recollection is necessary for associative recognition of item pairs. However, there are some reports suggesting that familiarity might support associative recognition judgments when the items form an easy to access bound representation. In contrast, recollection seems to be required for the recognition of bindings that might be flexibly rearranged in novel situations. We investigated whether both forms of binding are mediated by different mechanisms as reflected by a qualitatively different spatiotemporal eventrelated potential (ERP) pattern. In a recognition memory experiment, subjects gave old/new judgments to words learned by focusing either on interitem associations or on size relation of word triplets. Results revealed higher hit rates in the relational condition as compared to the associative condition. In addition, the proportion of triplets from which all three items were remembered was significantly larger in the relational condition suggesting that memory retrieval in this condition relies primarily on bound representations of word triplets. The ERP revealed a late parietal old/new effect for both conditions, with relational processing resulting in a greater effect. In contrast, an early frontal old/new effect was solely present in the associative condition. Taken together, these data provide evidence that familiarity might support associative recognition if the associated components are coherently encoded into a bound representation. Recollection might foster the recognition of relational bindings among items. This indicates that the contribution of familiarity and recollection to associative recognition depends on the kind of binding operations performed on the items rather than on the single versus multiple item distinction.
Blessed Men and Tribal Politics: Notes on Political Culture in the Indo-Afghan World
Authors: Green Nile 
Published: September 2006

AbstractThis article examines some of the foundations of the political culture of the Afghan communities of medieval North India through analysing the roles of Sufis and Sayyids in the arbitration of disputes. The social roles of such 'blessed men' are interpreted as part of a wider political culture in which places, objects and persons of mediation functioned on both the small scale of private quarrels and the grander scale of tribal and 'state' diplomacy. In both cases, the origins of this political culture are seen as a reflection of the segmentary society of the Indo-Afghan frontier and a response to the recurring interaction of its mobile social groups in India and beyond. Cet article s'attache à élucider les fondements de la culture politique des communautés afghanes de l'Inde médiévale en examinant les rôles qu'ont joués les soufies et les sayyids dans l'arbitrage des disputes. Ces 'hommes bénis' font partie intégrante d'une culture politique au sein de laquelle circulent objets, lieux et personnes médiatrices ; leur in fluence s'exerce tant au niveau des querelles personnelles qu'au niveau de la diplomatie de la tribu et de 'l'état'. Dans les deux cas, les origines de cette culture politique sont perçues comme re flet de la société segmentée de la frontière indo-afghane et comme réponse à l'interaction répétée de ces groupes sociaux en Inde et ailleurs.
Orographic Enhancement of Precipitation over Low Mountain Ranges. Part I: Model Formulation and Idealized Simulations
Authors: Kunz Michael , Kottmeier Christoph 
Published: September 2006

Abstract
A diagnostic model for simulating orographic precipitation over low mountain ranges is presented. It is based on linear theory of hydrostatic flow over mountains and calculates condensation rates from vertical lifting at the different model layers. Several other physical processes, such as hydrometeor drifting, evaporation, and moisture loss, are incorporated in the model by simple parameterizations. Idealized simulations of precipitation with different model performances provide insight into the physical processes of orographic precipitation. Evaporation, in combination with hydrometeor drifting into descent regions, is identified as one of the key aspects that primarily determine the spatial distribution of precipitation. The variability in orographic precipitation that results from changes in model parameters and ambient conditions is investigated in sensitivity studies. Simulated intensities as well as their spatial distributions are very sensitive to the temperature T0 at the lowest layer and to the variables that define the Froude number Frm: the horizontal wind speed U, static stability Nm, and mountain height H. Most of the parameters exhibit a nonlinear relation to the simulated precipitation intensities. Relative to ambient conditions, orographic precipitation is found to be less sensitive to changes in formation time tice, terminal velocity of ice particles υice, and melting level Δz. In each case, the sensitivities of simulation results strongly depend on the location in the model domain.
Extending the Predictability of Hydrometeorological Flood Events Using Radar Rainfall Nowcasting
Authors: Vivoni Enrique R. , Entekhabi Dara , Bras Rafael L. , Ivanov Valeriy Y. , Van Horne Matthew P. , Grassotti Christopher , Hoffman Ross N. 
Published: September 2006

Abstract
The predictability of hydrometeorological flood events is investigated through the combined use of radar nowcasting and distributed hydrologic modeling. Nowcasting of radar-derived rainfall fields can extend the lead time for issuing flood and flash flood forecasts based on a physically based hydrologic model that explicitly accounts for spatial variations in topography, surface characteristics, and meteorological forcing. Through comparisons to discharge observations at multiple gauges (at the basin outlet and interior points), flood predictability is assessed as a function of forecast lead time, catchment scale, and rainfall spatial variability in a simulated real-time operation. The forecast experiments are carried out at temporal and spatial scales relevant for operational hydrologic forecasting. Two modes for temporal coupling of the radar nowcasting and distributed hydrologic models (interpolation and extended-lead forecasting) are proposed and evaluated for flood events within a set of nested basins in Oklahoma. Comparisons of the radar-based forecasts to persistence show the advantages of utilizing radar nowcasting for predicting near-future rainfall during flood event evolution.
Stochastic Modeling of Daily Summertime Rainfall over the Southwestern United States. Part I: Interannual Variability
Authors: Wang Jingyun , Anderson Bruce T. , Salvucci Guido D. 
Published: September 2006

Abstract
The interannual variability of summertime daily precipitation at 78 stations in the southwestern United States is studied using chain-dependent models and nonparametric empirical distributions of daily rainfall amounts. Modeling results suggest that a second-order chain-dependent model can optimally portray the temporal structure of the summertime daily precipitation process over the southwestern United States. The unconditioned second-order chain-dependent model, in turn, can explain approximately 75% of the interannual variance in the seasonal total wet days over the region and 83% of the interannual variance in the seasonal total precipitation. In addition, only a small fraction (generally smaller than 20%) of the observed years at any given station show statistically significant changes in the occurrence and intensity characteristics, related to either the number of seasonal total wet days or the distributions of daily rainfall amounts. Investigations of the year-to-year variations in the occurrence and intensity characteristics indicate that both variations are random (on interannual time scales), and they display similar significance in explaining the remaining 17% of interannual variance of seasonal total precipitation over the region. However, numerical tests suggest that the interannual variations of the two are not independent for the summertime monsoon precipitation, and that complex covariability that cannot be described with simple stochastic statistical models may exist between them.
Multimodel Combination Techniques for Analysis of Hydrological Simulations: Application to Distributed Model Intercomparison Project Results
Authors: Ajami Newsha K. , Duan Qingyun , Gao Xiaogang , Sorooshian Soroosh 
Published: September 2006

Abstract
This paper examines several multimodel combination techniques that are used for streamflow forecasting: the simple model average (SMA), the multimodel superensemble (MMSE), modified multimodel superensemble (M3SE), and the weighted average method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All of the multimodel combination results were obtained using uncalibrated DMIP model simulations and were compared against the best-uncalibrated as well as the best-calibrated individual model results. The purpose of this study is to understand how different combination techniques affect the accuracy levels of the multimodel simulations. This study revealed that the multimodel simulations obtained from uncalibrated single-model simulations are generally better than any single-member model simulations, even the best-calibrated single-model simulations. Furthermore, more sophisticated multimodel combination techniques that incorporated bias correction step work better than simple multimodel average simulations or multimodel simulations without bias correction.
Noise Reduction of Atmospheric Emitted Radiance Interferometer (AERI) Observations Using Principal Component Analysis
Authors: Turner D. D. , Knuteson R. O. , Revercomb H. E. , Lo C. , Dedecker R. G. 
Published: September 2006

Abstract
A principal component noise filter has been applied to ground-based high-spectral-resolution infrared radiance observations collected by the Atmospheric Emitted Radiance Interferometers (AERIs) deployed by the Atmospheric Radiation Measurement (ARM) program. The technique decomposes the radiance observations into their principal components, selects the ones that describe the most variance in the data, and reconstructs the data from these components. An empirical function developed for chemical analysis is utilized to determine the number of principal components to be used in the reconstruction of the data. Statistical analysis of the noise-filtered minus original radiance data, as well as side-by-side analysis of data from two AERI systems utilizing different temporal sampling, demonstrates the ability of the noise filter using this empirical function to retain most of the atmospheric signal above the AERI noise level in the filtered data. The noise filter is applied to data collected at ARM’s tropical, midlatitude, and Arctic sites, demonstrating that the random variability in the data is reduced by 5% to over 450%, depending on the spectral element and location of the instrument. A seasonal analysis of the number of principal components required by the noise filter for each site shows a strong seasonal dependence in the atmospheric variability at the Arctic and midlatitude sites but not at the tropical site.
Entrainment and Transport in Idealized Three-Dimensional Gravity Current Simulation
Authors: Tseng Yu-Heng , Dietrich David E. 
Published: September 2006

Abstract
A purely z-coordinate Dietrich/Center for Air Sea Technology (DieCAST) ocean model is applied to the Dynamics of Overflow Mixing and Entrainment (DOME) idealized bottom density current problem that is patterned after the Denmark Strait. The numerical results show that the background viscosity plays a more important role than the chosen coordinate system in the entrainment and mixing if the background viscosity is not small enough. Both higher horizontal viscosity and coarser resolution leads to slower along-slope propagation. Reducing vertical mixing parameterization also leads to slower along-slope propagation with thicker plume size vertically. The simulation gives consistent results for the moderate- and fine-resolution runs. At a very coarse grid the dense water descends more slowly and is mainly dominated by diffusion. Time-averaged downstream transport and entrainment are not very sensitive to viscosity after the flow reaches its quasi-steady status. However, more realistic eddies and flow structures are found in low-viscosity runs. The results show good convergence of the resolved flow as expected and clarify the effects of numerical dissipation/mixing on overflow modeling. Larger numerical dissipation is not required nor recommended in z-coordinate models.
Comparison of Impacts of WRF Dynamic Core, Physics Package, and Initial Conditions on Warm Season Rainfall Forecasts
Authors: Gallus William A. , Bresch James F. 
Published: September 2006

Abstract
A series of simulations for 15 events occurring during August 2002 were performed using the Weather Research and Forecasting (WRF) model over a domain encompassing most of the central United States to compare the sensitivity of warm season rainfall forecasts with changes in model physics, dynamics, and initial conditions. Most simulations were run with 8-km grid spacing. The Advanced Research WRF (ARW) and the nonhydrostatic mesoscale model (NMM) dynamic cores were used. One physics package (denoted NCEP) used the Betts–Miller–Janjic convective scheme with the Mellor–Yamada–Janjic planetary boundary layer (PBL) scheme and GFDL radiation package; the other package (denoted NCAR) used the Kain–Fritsch convective scheme with the Yonsei University PBL scheme and the Dudhia rapid radiative transfer model radiation. Other physical schemes were the same (e.g., the Noah land surface model, Ferrier et al. microphysics) in all runs. Simulations suggest that the sensitivity of the model to changes in physics is a function of which the dynamic core is used, and the sensitivity to the dynamic core is a function of the physics used. The greatest sensitivity in general is associated with a change in physics packages when the NMM core is used. Sensitivity to a change in physics when the ARW core is used is noticeably less. For light rainfall, the spread in the rainfall forecasts when physics are changed under the ARW core is actually less at most times than when the dynamic core is changed while NCAR physics are used. For light rainfall, the WRF model using NCAR physics is much more sensitive to a change in dynamic core than the WRF model using NCEP physics. For heavier rainfall, the opposite is true with a greater sensitivity occurring when NCEP physics is used. Sensitivity to initial conditions (Eta versus the Rapid Update Cycle with an accompanying small change in grid spacing) is generally less substantial than the sensitivity to changes in dynamic core or physics, except in the first 6–12 h of the forecast when it is comparable. As might be expected for warm season rainfall, the finescale structure of rainfall forecasts is more affected by the physics used than the dynamic core used. Surprisingly, however, the overall areal coverage and rain volume within the domain may be more influenced by the dynamic core choice than the physics used.
Smad1 expands the hemangioblast population within a limited developmental window
Authors: Zafonte Brian T. , Liu Susanna , Lynch-Kattman Macarena , Torregroza Ingrid , Benvenuto Luke , Kennedy Marion , Keller Gordon , Evans Todd 
Published: September 2006

AbstractBone morphogenetic protein (BMP) signaling is an important regulator of hematovascular development. However, the progenitor population that responds to BMP signaling is undefined, and the relative role of downstream mediators including Smad1 is unclear. We find that Smad1 shows a distinctive expression profile as embryonic stem (ES) cells undergo differentiation in the embryoid body (EB) system, with peak levels in cell populations enriched for the hemangioblast. To test the functional relevance of this observation, we generated an ES cell line that allows temporal control of ectopic Smad1 expression. Continuous expression of Smad1 from day 2 of EB culture does not disturb hematopoiesis, according to colony assays. In contrast, a pulse of Smad1 expression exclusively between day 2 and day 2.25 expands the population of progenitors for primitive erythroblasts and other hematopoietic lineages. This effect correlates with increased levels of transcripts encoding markers for the hemangioblast, including Runx1, Scl, and Gata2. Indeed, the pulse of Smad1 induction also expands the blast colony-forming cell (BL-CFC) population at a level that is fully sufficient to explain subsequent increases in hematopoiesis. Our data demonstrate that Smad1 expression is sufficient to expand the number of cells that commit to hemangioblast fate.
Low rhodamine 123 retention identifies long-term human hematopoietic stem cells within the Lin−CD34+CD38− population
Authors: McKenzie Joby L. , Takenaka Katsuto , Gan Olga I. , Doedens Monica , Dick John E. 
Published: September 2006

AbstractProgress to uncover the molecular and cellular regulators that govern human hematopoietic stem cell (HSC) fate has been impeded by an inability to obtain highly purified fractions of HSCs. We report that the rhodamine 123 (Rho 123) dye effluxing fraction of the Lin−CD34+CD38− population contains SCID-repopulating cells (SRCs) capable of long-term repopulation in primary nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Purification based on Rho uptake led to a 4-fold enrichment of SRCs in the Lin−CD34+CD38− fraction, with a frequency of 1 SRC in 30 Lin−CD34+CD38−Rholo cells. The Lin−CD34+CD38−Rholo fraction also possesses long-term self-renewal capacity as measured by serial transplantation totaling more than 20 weeks. We conclude that Rho dye efflux provides an additional means of purifying human HSCs in the quest to achieve homogeneous populations of primitive cells for both experimental and therapeutic applications.