bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relevance of background‐error covariance matrix localization: an application to the variational retrieval of vertical profiles from SEVIRI observations
Authors: Di Giuseppe F. , Marsigli C. , Paccagnella T. 
Published: January 2011

AbstractA method to select local statistics for background‐error covariance matrix (B) determination is presented and applied to the 1D‐Var+nudging assimilation of SEVIRI radiances in the COSMO model. The system is designed as a post‐processing algorithm of an ensemble forecast system based on multi‐model initial and boundary conditions and perturbations of physical parametrization parameters. Ensemble spread maps are combined to identify regions (‘islands’) inside the model domain of uniform and large error. Thereafter B matrices are calculated using local statistics from the identified islands assuming the ensemble spread to be representative of the background‐error dispersion. This calculation is repeated at the beginning of each assimilation cycle to ensure the time evolution of the selected regions and thus the flow‐dependency of the background‐error covariance matrix statistics.The benefit of calculating B using local statistics is then quantified by comparison to background covariance errors evaluated from global domain statistics. This is done using the same ensemble members over the whole domain, i.e. without applying the localization procedure. The standard NMC approach, which uses long time series of model departures calculated at different forecast times, is also compared for reference. Model departure statistics and comparison of the final analysis to independent observations from surface stations and satellite products highlight the relevance of the localization procedure even though the noisy structure of the variance profiles produces a substantial reduction in the number of valid retrieved profiles. The final findings show that the selective identification of areas of homogeneous spread/error is a suitable approach to characterize local error growth which can bring about sensible improvements in the forecast scores. Copyright © 2011 Royal Meteorological Society
The water vapour intercomparison effort in the framework of the Convective and Orographically‐induced Precipitation Study: airborne‐to‐ground‐based and airborne‐to‐airborne lidar systems
Authors: Bhawar R. , Di Girolamo P. , Summa D. , Flamant C. , Althausen D. , Behrendt A. , Kiemle C. , Bosser P. , Cacciani M. , Champollion C. , Di Iorio T. , Engelmann R. , Herold C. , Müller D. , Pal S. , Wirth M. , Wulfmeyer V. 
Published: January 2011

AbstractAn intensive water vapour intercomparison effort, involving airborne and ground‐based water vapour lidar systems, was carried out in the framework of the COPS experiment. The main objective of this paper is to provide accurate error estimates for these systems.Comparisons between the ground‐based Raman lidar BASIL and the airborne CNRS DIAL (Differential Absorption Lidar) indicate a mean relative bias between the two sensors, calculated with respect to the mean value of −2.13% (−0.034 g kg−1) in the altitude region 0.5–3.5 km, while comparisons between BASIL and the airborne DLR DIAL lead to a mean relative bias of 1.87% (0.018 g kg−1) in this same altitude region.Comparisons between the ground‐based UHOH DIAL and the CNRS DIAL indicate a bias of −3.2% (−0.37 × 1022 m−3) in the altitude range 1.5–4.5 km, while comparisons between the UHOH DIAL and the DLR DIAL indicate a bias of 0.83% (0.06 × 1022 m−3) in this same altitude range. Based on the available comparisons between the ground‐based Raman lidar BERTHA and the CNRS DIAL, the mean relative bias is found to be −4.37% (−0.123 g kg−1) in the altitude region 0.5–4.5 km. Comparisons between the ground‐based IGN Raman lidar and the CNRS DIAL indicate a bias of 3.18% (0.55 g kg−1) in the altitude range from 0.5 to 4.5 km, while comparisons between the CNRS DIAL and DLR DIAL result in a mean relative bias of 3.93% (1.1 × 1022 m−3) in the altitude interval 0.5–4.0 km. Based on the available statistics of comparisons, benefiting from the fact that the CNRS DIAL was able to be compared with all other lidar systems, and putting equal weight on the data reliability of each instrument, overall relative values for BASIL, BERTHA, IGN Raman lidar, UHOH DIAL, DLR DIAL, and CNRS DIAL, with respect to the mean value, are found to be −0.38, −2.60, 4.90, −1.43, −2.23 and 1.72%, respectively. Copyright © 2011 Royal Meteorological Society
Initiation of deep convection at marginal instability in an ensemble of mesoscale models: a case‐study from COPS
Authors: Barthlott Christian , Burton Ralph , Kirshbaum Daniel , Hanley Kirsty , Richard Evelyne , Chaboureau Jean‐Pierre , Trentmann Jörg , Kern Bastian , Bauer Hans‐Stefan , Schwitalla Thomas , Keil Christian , Seity Yann , Gadian Alan , Blyth Alan , Mobbs Stephen , Flamant Cyrille , Handwerker Jan 
Published: January 2011

AbstractThe present study investigates the initiation of precipitating deep convection in an ensemble of convection‐resolving mesoscale models. Results of eight different model runs from five non‐hydrostatic models are compared for a case of the Convective and Orographically‐induced Precipitation Study (COPS). An isolated convective cell initiated east of the Black Forest crest in southwest Germany, although convective available potential energy was only moderate and convective inhibition was high. Measurements revealed that, due to the absence of synoptic forcing, convection was initiated by local processes related to the orography. In particular, the lifting by low‐level convergence in the planetary boundary layer is assumed to be the dominant process on that day. The models used different configurations as well as different initial and boundary conditions. By comparing the different model performance with each other and with measurements, the processes which need to be well represented to initiate convection at the right place and time are discussed. Besides an accurate specification of the thermodynamic and kinematic fields, the results highlight the role of boundary‐layer convergence features for quantitative precipitation forecasts in mountainous terrain. Copyright © 2011 Royal Meteorological Society
Forecasting summer convection over the Black Forest: a case study from the Convective and Orographically‐induced Precipitation Study (COPS) experiment
Authors: Richard E. , Chaboureau J.‐P. , Flamant C. , Champollion C. , Hagen M. , Schmidt K. , Kiemle C. , Corsmeier U. , Barthlott C. , Di Girolamo P. 
Published: January 2011

AbstractIn the mid‐afternoon of 15 July 2007, during the Convective and Orographically‐induced Precipitation Study (COPS), in a very warm and dry environment, an isolated, short‐lived, deep convective system developed over the southern Black Forest. Most of the high‐resolution, convection‐permitting models involved in COPS were unable to capture this event whereas the Meso‐NH forecast was quite skilful. To assess the Meso‐NH performance further, the model results were carefully checked against the various and numerous COPS observations. In full agreement with clear‐air radar observations, model results underlined the triggering role of a low‐level convergence line that developed in the lee of the Feldberg. The main departure from the observations was found to be in the low‐level moisture fields, which appeared significantly moister in the model than in the observations and also slightly moister than in the other models. Sensitivity studies showed that this departure from the observations was strongly controlled by the initial surface moisture conditions. When the surface moisture was reduced by 20% or replaced by the value derived from a different analysis, the evolution of the planetary boundary layer was more accurately represented while the storm evolution was still correctly captured. These results demonstrate that the quality of the initial forecast cannot be ascribed to the moist bias of the model. It could therefore be hypothesized that the key parameters for a satisfactory forecast of this event lie more in the ability of the model to reproduce the dynamical forcing accurately than in the characteristics of the air‐mass instability. Copyright © 2011 Royal Meteorological Society
Unified treatment of dry convective and stratocumulus‐topped boundary layers in the ECMWF model
Authors: Köhler M. , Ahlgrimm M. , Beljaars A. 
Published: January 2011

AbstractThe unified parametrization of the dry boundary layer and stratocumulus in the ECMWF model is described using the eddy diffusivity mass‐flux framework. Model simulations are compared to observations at a few selected research field experiments, to ISCCP cloud cover, to LIDAR from space cloud observations, to SYNOP observations over Europe and to the climatology. It is shown that the new stratocumulus formulation improved the quality of the stratocumulus simulations rather dramatically. The key ingredients are: (i) mixing in moist conserved variables, (ii) diffusion related to cloud‐top cooling, (iii) an additional mass‐flux term, (iv) an entrainment parametrization and (v) a switching between shallow cumulus and stratocumulus based on lower tropospheric stability. To illustrate the relevance of various aspects, the sensitivity to different parameters is also presented. Copyright © 2011 Royal Meteorological Society
Cortisol outcomes among caucasian and latina/hispanic women caring for a family member with dementia: a preliminary examination of psychosocial predictors and effects of a psychoeducational intervention
Authors: Holland Jason M. , Thompson Larry W. , Cucciare Michael A. , Tsuda Akira , Okamura Hisayoshi , Spiegel David , Rasgon Natalie L. , Gallagher‐Thompson Dolores 
Published: January 2011

AbstractA host of interventions are now known to be helpful to alleviate subjective distress and improve well‐being in dementia caregivers. However, few intervention studies have focused on measures of physical health, and none have examined cortisol as an outcome—despite the fact that cortisol is regarded as a crucial biological intermediary by which chronic stress leads to disease. In this study, we examined demographic and psychosocial factors as predictors of salivary cortisol at a baseline assessment, among a sample of 175 Latino/Hispanic and Caucasian women caring for a family member with dementia. We also examined the influence of a cognitive–behaviour‐based psychoeducational intervention (Coping with Caregiving) on cortisol at a post‐treatment assessment, compared with a minimal support condition. Results revealed that caregivers with high intensity caregiving situations, characterized by long hours of care and co‐residence with the care recipient, tended to have less adaptive cortisol patterns. However, these ‘at‐risk’ caregivers benefited most from the Coping with Caregiving intervention and had more normal cortisol patterns at post‐treatment, compared with caregivers in the control condition. Copyright © 2011 John Wiley & Sons, Ltd.
Imposing resolved turbulence in CFD simulations
Authors: Gilling L. , Sørensen N. N. 
Published: January 2011

AbstractIn large‐eddy simulations, the inflow velocity field should contain resolved turbulence. This paper describes and analyzes two methods for imposing resolved turbulence in the interior of the domain in Computational Fluid Dynamics simulations. The intended application of the methods is to impose resolved turbulence immediately upstream of the region or structure of interest. Comparing to the alternative of imposing the turbulence at the inlet, there is a large potential to reduce the computational cost of the simulation by reducing the total number of cells. The reduction comes from a lower demand for mesh resolution in the upstream part of the domain. The first method uses a modification of the source terms in the discrete Navier‐Stokes equations. In the second method, an actuator is used to impose the turbulence. The methods are tested, and the most accurate is shown to be the approach of modifying the source terms. None of the two methods can impose synthetic turbulence with good results, but it is shown that by running the turbulence field through a short precursor simulation, very good results are obtained. Copyright © 2011 John Wiley & Sons, Ltd.
Multivariate random forests
Authors: Segal Mark , Xiao Yuanyuan 
Published: January 2011

AbstractRandom forests have emerged as a versatile and highly accurate classification and regression methodology, requiring little tuning and providing interpretable outputs. Here, we briefly outline the genesis of, and motivation for, the random forest paradigm as an outgrowth from earlier tree‐structured techniques. We elaborate on aspects of prediction error and attendant tuning parameter issues. However, our emphasis is on extending the random forest schema to the multiple response setting. We provide a simple illustrative example from ecology that showcases the improved fit and enhanced interpretation afforded by the random forest framework. © 2011 John Wiley & Sons, Inc. WIREs Data Mining Knowl Discov 2011 1 80‐87 DOI: 10.1002/widm.12This article is categorized under:

Algorithmic Development > Hierarchies and Trees
Algorithmic Development > Ensemble Methods
Technologies > Machine Learning
Technologies > Prediction
Multivariate image mining
Authors: Herold Julia , Loyek Christian , Nattkemper Tim W. 
Published: January 2011

AbstractBecause of recent advances in sensor technology and a rapid increase in storage capacities, a growing number of intensity values can be recorded and associated with pixel coordinates using new imaging technologies. This growth in dimension can be observed in different scientific areas and this new category of images is referred to as multivariate images (MVIs). In these images, an almost arbitrary number of variables is associated with each pixel that represent, for instance, signal values at different time points or for different spectral bands or for different imaging parameters or modalities. Thus, these images can no longer be interpreted as gray value images or red, green, blue color images, and new information technologies are needed. In this review article, we summarize the different imaging technologies and recently published approaches to MVI mining with a special focus on biomedical applications. © 2011 John Wiley & Sons, Inc.WIREs Data Mining Knowl Discov2011 1 2‐13 DOI: 10.1002/widm.4This article is categorized under:Algorithmic Development > Biological Data MiningAlgorithmic Development > Spatial and Temporal Data MiningApplication Areas > Health CareTechnologies > Structure Discovery and Clustering
Classification and regression trees
Authors: Loh Wei‐Yin 
Published: January 2011

AbstractClassification and regression trees are machine‐learning methods for constructing prediction models from data. The models are obtained by recursively partitioning the data space and fitting a simple prediction model within each partition. As a result, the partitioning can be represented graphically as a decision tree. Classification trees are designed for dependent variables that take a finite number of unordered values, with prediction error measured in terms of misclassification cost. Regression trees are for dependent variables that take continuous or ordered discrete values, with prediction error typically measured by the squared difference between the observed and predicted values. This article gives an introduction to the subject by reviewing some widely available algorithms and comparing their capabilities, strengths, and weakness in two examples. © 2011 John Wiley & Sons, Inc. WIREs Data Mining Knowl Discov 2011 1 14‐23 DOI: 10.1002/widm.8This article is categorized under:

Technologies > Classification
Technologies > Machine Learning
Technologies > Prediction
Algorithmic Development > Statistics
Accelerating data mining workloads: current approaches and future challenges in system architecture design
Authors: Choudhary Alok N. , Honbo Daniel , Kumar Prabhat , Ozisikyilmaz Berkin , Misra Sanchit , Memik Gokhan 
Published: January 2011

AbstractConventional systems based on general‐purpose processors cannot keep pace with the exponential increase in the generation and collection of data. It is therefore important to explore alternative architectures that can provide the computational capabilities required to analyze ever‐growing datasets. Programmable graphics processing units (GPUs) offer computational capabilities that surpass even high‐end multi‐core central processing units (CPUs), making them well‐suited for floating‐point‐ or integer‐intensive and data parallel operations. Field‐programmable gate arrays (FPGAs), which can be reconfigured to implement an arbitrary circuit, provide the capability to specify a customized datapath for any task. The multiple granularities of parallelism offered by FPGA architectures, as well as their high internal bandwidth, make them suitable for low complexity parallel computations. GPUs and FPGAs can serve as coprocessors for data mining applications, allowing the CPU to offload computationally intensive tasks for faster processing. Experiments have shown that heterogeneous architectures employing GPUs or FPGAs can result in significant application speedups over homogenous CPU‐based systems, while increasing performance per watt. © 2011 John Wiley & Sons, Inc.WIREs Data Mining Knowl Discov2011 1 41‐54 DOI: 10.1002/widm.9This article is categorized under:Application Areas > Data Mining Software ToolsFundamental Concepts of Data and Knowledge > Key Design Issues in Data MiningTechnologies > Computer Architectures for Data Mining
Expression and Function of a Large Non‐coding RNA Gene XIST in Human Cancer
Authors: Weakley Sarah M. , Wang Hao , Yao Qizhi , Chen Changyi 
Published: January 2011

AbstractBackgroundX inactive‐specific transcript (XIST) RNA is involved in X chromosome silencing in female cells and allows X chromosome equilibration with males. X inactive‐specific transcript expression has been found to be dysregulated in a variety of human cancers when compared to normal cells; meanwhile, the inactivated X chromosome has been noted to be conspicuously absent in human cancer specimens, whereas X chromosome duplications are widely noted. The specific pathways whereby changes in X chromosome status and XIST expression occur in cancer remain incompletely described. Nevertheless, a role for XIST in BRCA1‐mediated epigenetic activity has been proposed.MethodsHere we review the data regarding XIST expression and X chromosome status in a variety of female, male, and non–sex‐related human cancers.ConclusionsIt is not yet known whether X chromosome duplication, XIST dysregulation, and over‐expression of X‐linked genes represent important factors in tumorgenesis or are simply a consequence of overall epigenetic instability in these cancers.
Shifting sources of soil labile organic carbon after termination of plant carbon inputs in a subtropical moist forest of southwest China
Authors: Feng Wenting , Schaefer Douglas A. , Zou Xiaoming , Zhang Min 
Published: January 2011

AbstractLabile organic carbon (LOC) is a critical component of soil organic carbon (C) because of its intimate association with soil heterotrophic respiration and role in the decomposition of resistant soil organic matter. In a subtropical moist evergreen broad‐leaved forest of southwest China, we examined changes of LOC and its potential turnover time, microbial biomass C (MBC), and soil microbial activity of the organic and the 0–10 cm mineral soil layers with aboveground plant litter and belowground root treatments. In February of 2004, removal of organic layer, root‐trenching, and tree‐girdling treatments were applied alone and in combination to manipulate plant‐C inputs. In 2006, root‐trenching and tree‐girdling treatments did not significantly change LOC in the organic layer. In the 0–10 cm mineral soil layer, LOC increased substantially due to tree‐girdling treatment, especially in the plots of tree‐girdling and the combinations of three treatments, but this increase was absent in 2007. Soil MBC in these two layers generally did not change markedly after plant‐C inputs manipulations except significant increase under tree‐girdling treatment in 2006. The potential turnover times of LOC increased in all plots with the plant‐C inputs manipulations. The lack of influence of plant‐C inputs manipulations on LOC pools is likely due to high total soil organic C here, while insignificant changes of MBC suggest the soil microbes are not C limited in this forest. The changes of the potential turnover time of LOC imply that the sources of LOC have been shifted from fresh plant litter or root exudates to old soil organic C. Our results suggest that LOC recently derived from plants is preferred by microbes when available, but microbes can also use LOC from soil organic matter when fresh plant C is not available.
Dorsal Tangential View of the Wrist to Detect Screw Penetration to the Dorsal Cortex of the Distal Radius after Volar Fixed-Angle Plating
Authors: Ozer Kagan , Toker Serdar 
Published: January 2011

Background Extensor tendon irritation and attritional tendon ruptures are well-recognized complications, secondary to dorsal screw penetration following volar plating of the distal radius. Lateral and oblique views of the wrist have limited ability to detect such penetration, particularly at the ulnar side of the Lister's tubercle. In this report, we conducted an intraoperative fluoroscopic study to determine dorsal screw penetration in various positions of the wrist/forearm and compared the standard radiographic views (lateral, supination, and pronation views) with dorsal tangential view of the wrist. Materials and Method Standard lateral, oblique (in pronation and supination), and dorsal tangential views were obtained in 27 consecutive patients undergoing fixation a distal radius fractures using a volar plate. The number of penetrating screws in each dorsal compartment (second, third, fourth) was recorded in each view. Dorsal tangential view was obtained using a mini C-arm intraoperatively and sending the beam parallel to the dorsal aspect of the wrist in transverse plane. Results Of the 125 distal screws, 8 screws were seen to be penetrating the dorsal cortex in lateral and oblique views, whereas 11 screws were detected in dorsal tangential view. Conclusion The screw penetration to the third dorsal compartment was missed in standard views, but visualized in dorsal tangential view. We recommend the use of dorsal tangential view in addition to standard lateral and oblique views during volar plating of the distal radius.
Pilot Plant Recovery of Soybean Oleosome Fractions by an Enzyme‐Assisted Aqueous Process
Authors: Towa Lili T. , Kapchie Virginie N. , Hauck Catherine , Wang Hui , Murphy Patricia A. 
Published: January 2011

AbstractAn aqueous enzymatic procedure for oleosome fractionation from 25 g of soy flour was developed in our laboratory. This fractionation procedure was evaluated with 75 kg using pilot plant equipment to evaluate the effect of the scale‐up on the recovery, proximate composition, soybean storage protein profiles, and subcellular microstructure of oleosome fractions. The process included enzymatic hydrolysis, grinding, and centrifugation, respectively. Pilot‐scale grinding and centrifugation of the slurry were accomplished with a Stephan® Microcut mill grinder and a three phase decanter. A blender and swinging bucket rotor were used for the laboratory‐scale fractionation. The oleosome fractions recovered in the pilot plant were similar in oil and protein content to those obtained in the laboratory. The pilot‐scale process resulted in a significantly higher oil yield of 93.40% as total oleosomes compared to that of 76.83% achieved in the laboratory. Urea–SDS gel electrophoresis of proteins extracted from the oleosomes and supernatant from the pilot‐scale fractionation had similar profiles to those obtained in the laboratory. Electron microscopy verified that the structure of isolated oleosomes was virtually identical with that of in situ oleosomes. This work confirms that large‐scale fractionation of oleosomes from full fat soybean flour can be accomplished.