bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Reservoir Data Assimilation With an Efficient, Dimension-Reduced Kalman Filter
Authors: Zhang Dongxiao , Lu Zhiming , Chen Yan 
Published: March 2007

Summary
Kalman filter-based methods have been widely applied for assimilating new measurements to continuously update the estimate of state variables, such as reservoir properties and responses. The standard Kalman filtering scheme requires computing and storing the covariance matrix of state variables, which is computationally expensive for large-scale problems with millions of gridblocks. In the ensemble Kalman filter (EnKF), this problem is alleviated with sampling from a limited number of realizations and computing the required subset of the covariance matrix at each update. However, the goodness of the (ensemble) covariance approximated from the limited ensemble depends on the number of realizations used and the representativity of a given ensemble. In this study, we propose an efficient, dimension-reduced Kalman filtering scheme based on Karhunen-Loeve (KL) and other orthogonal polynomial decompositions of the state variables. We consider flow in heterogeneous reservoirs with spatially variable permeability. The reservoir responses such as pressure are measured at some locations at various time intervals. The aim is to dynamically characterize the reservoir properties and to predict the reservoir performance and its uncertainty at future times. In our scheme, the covariance of the reservoir properties is approximated by a small set of eigenvalues and eigenfunctions using the KL decomposition and the reconstruction of the covariance from the KL decomposition can be done whenever needed. In each update, the forecast step is solved using the KL-based moment method, giving a set of functions from which the mean and covariance of the state variables can be constructed, when needed. The statistics of both the reservoir properties and the reservoir responses are then updated with the available measurements at this time using the auto-and cross-covariances obtained from the forecast step. The new approach is illustrated on a heterogeneous reservoir with dynamic measurements and the results are compared with those from the EnKF method, in terms of accuracy and efficiency.
Modeling Thermally Induced Compaction in Diatomite
Authors: Dietrich J. K. , Scott J. D. 
Published: March 2007

SummaryDiatoms and radiolarians are microorganisms that precipitate Opal-A to form siliceous tests that accumulate on the seafloor to form siliceous oozes. Progressive diagenesis of these deposits during burial results in thick, highly compressible reservoirs of exceptionally high porosity and low permeability, not unlike the chalk reservoirs of the North Sea. During burial and over time, the amorphous silica phase (Opal-A) becomes unstable and gradually changes in its structure to more stable, ordered Opal-A′ and crystalline forms or phases of silica, namely Opal-CT and quartz. The Opal-A→Opal-A′→Opal-CT→quartz transformation results in a naturally occurring densification and compaction process that is accelerated by an application of heat. Reservoir compaction and surface subsidence can usually be controlled by injecting fluid to control the effective stress. However, in heavy-oil diatomite reservoirs undergoing steam injection, the injected fluid causes competing effects: it controls effective stress to some degree, yet at the same time it accelerates compaction and subsidence.This paper describes selected results of a diatomite laboratory testing program and features of a unique thermal reservoir simulator formulated to handle the effects on compaction caused by stress, temperature, and time-dependent strain (creep). Elevated temperature in amorphous Opal-A diatomite is shown to be capable of causing a sample compression of 25% or more and a severe reduction in permeability. The effects of thermally induced compaction are expected to accelerate surface subsidence as diatomite steam projects mature.
Use of Outpatient Physical Therapy Services by People With Musculoskeletal Conditions
Authors: Carter Stephanie K , Rizzo John A 
Published: March 2007

Background and PurposeBecause musculoskeletal conditions contribute to functional decline and activity limitation, physical therapy intervention may be an appropriate health care resource. The purpose of this research was to identify determinants of outpatient physical therapy use by people with musculoskeletal conditions.SubjectsThe subjects were adult noninstitutionalized civilians who participated in the Medical Expenditure Panel Survey from 1996 to 2000 and who had at least one musculoskeletal condition (N=18,546).MethodsLogistic regression was used to identify predisposing, need, and enabling variables associated with receiving outpatient physical therapy services.ResultsFactors that were positively associated with receiving physical therapy services were having more than one musculoskeletal condition, having some limitation in function, having 7 or more ICD-9 (International Classification of Diseases, 9th Revision) codes, having a college or advanced degree, and residing in an urban area. Factors that were negatively associated with receiving physical therapy services were being older than 65 years of age, having no high school degree, Hispanic ethnicity, African-American race, having public insurance or no insurance, and living in any US census region besides the Northeast.Discussion and ConclusionThe results of this study indicate that health- and non–health-related factors influence outpatient physical therapy use.
Implementation of a Strength Training Program for a 5-Year-Old Child With Poor Body Awareness and Developmental Coordination Disorder
Authors: Kaufman Linda B , Schilling Denise L 
Published: March 2007

Background and PurposeThis case report describes how a strength (muscle force-generating capacity) training program was associated with changes in muscle strength, motor function, and proprioceptive position sense in a young child with poor body awareness and a diagnosis of developmental coordination disorder.Case DescriptionAssessment of a prekindergarten child referred for physical therapy because of behaviors compatible with poor body awareness revealed muscle weakness, poor performance on the Bruininks-Oseretsky Test of Motor Proficiency, and poor proprioception. Physical therapy testing done when the child was 5 years of age contributed to a pediatrician-assigned diagnosis of developmental coordination disorder. A 12-week strength training program was initiated.OutcomesImprovements were noted in muscle strength, gross motor function, and proprioception.DiscussionResearch indicates that muscles provide information about joint position. Evidence suggests that muscle strength gains seen in children are the result of neuromuscular learning and neural adaptations; therefore, a structured strength training program may have contributed to proprioceptive changes in this child.
Strain Accommodation during Phase Transformations in Olivine‐Based Cathodes as a Materials Selection Criterion for High‐Power Rechargeable Batteries
Authors: Meethong N. , Huang H.‐Y. S. , Speakman S. A. , Carter W. C. , Chiang Y.‐M. 
Published: March 2007

AbstractHigh energy lithium‐ion batteries have improved performance in a wide variety of mobile electronic devices. A new goal in portable power is the achievement of safe and durable high‐power batteries for applications such as power tools and electric vehicles. Towards this end, olivine‐based positive electrodes are amongst the most important and technologically enabling materials. While certain lithium metal phosphate olivines have been shown to be promising, not all olivines demonstrate beneficial properties. The mechanisms allowing high power in these compounds have been extensively debated. Here we show that certain high rate capability olivines are distinguished by having extended lithium nonstoichiometry (up to ca. 20 %), with which is correlated a reduced lattice misfit as the material undergoes an electrochemically driven, reversible, first‐order phase transformation. The rate capability in several other intercalation oxides can also be correlated with lattice strain, and suggests that nanomechanics plays an important and previously unrecognized role in determining battery performance.
Design of solvents for optimal reaction rate constants
Authors: Folić Milica , Adjiman Claire S. , Pistikopoulos Efstratios N. 
Published: March 2007

AbstractA hybrid experimental/computer‐aided methodology for the design of solvents for reactions is presented. It is based on the use of a few reaction rate measurements to build a reaction model, followed by the formulation and solution of an optimal computer‐aided molecular design problem (CAMD) in which the reaction rate under given conditions is maximized. In order to verify the suitability of the solvent candidates identified in the CAMD step, and to assess the reliability of the model used, feedback can be introduced. When the reliability of the model is found to be insufficient, experimental rate data for the candidate solvents are obtained and added to the original data set to create an updated reaction model, which can be used to find new candidate solvents. Since very few measurements are used to build the reaction model, we perform a sensitivity analysis on the model to assess the impact of uncertainty. Using this information to generate scenarios, we then solve a stochastic optimization problem, which aims to determine the solvents that give the best average performance. The final output consists of a list of candidate solvents which can be targeted for experimentation. This methodology is illustrated, step by step, through application to a solvolysis reaction. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Taylor‐Couette unit with a lobed inner cylinder cross section
Authors: Soos Miroslav , Wu Hua , Morbidelli Massimo 
Published: March 2007

AbstractA new mixing unit, based on a modification of the classical Taylor‐Couette (TC) unit is proposed, where a lobed profile of the inner cylinder cross section is used. The shear rate distribution of the lobed Taylor‐Couette (LTC) unit have been computed through computational fluid dynamic simulations and compared with those of the TC unit and a standard stirred tank (ST). It is found that since the flow pattern of the LTC units becomes temporal‐periodic at each point with respect to the nonrotational outer cylinder, it reduces the formation of the low velocity gradient (low shear rate) region, typically generated in the vortex core of the TC units. The obtained distributions of the shear rate are substantially narrower than those of the TC and the ST units. Variation of the ratio between the maximum and the minimum gap widths can lead to significant changes in the shear rate distribution, and there exists an optimal range of such ratio, where the shear rate distribution is not only very narrow but also insensitive to the variation of the gap widths. © 2007 American Institute of Chemical Engineers AIChE J, 2007
The dynamics of interactive information retrieval, Part II: An empirical study from the activity theory perspective
Authors: Xu Yunjie , Liu Chengliang 
Published: March 2007

AbstractHuman information‐seeking behavior is complicated. Activity theory is a powerful theoretical instrument to untangle the “complications.” Based on activity theory, a comprehensive framework is proposed in Part I (Y. Xu, 2007) of this report to describe interactive information retrieval (IIR) behavior. A set of propositions is also proposed to describe the mechanisms governing users' cognitive activity and the interaction between users' cognitive states and manifested retrieval behavior. An empirical study is carried out to verify the propositions. The authors' experimental simulation of 81 participants in one search session indicates the propositions are largely supported. Their findings indicate IIR behavior is planned. Users adopt a divide‐and‐conquer strategy in information retrieval. The planning of information retrieval activity is also partially manifested in query revision tactics. Users learn from previously read documents. A user's interaction with a system ultimately changes the user's information need and the resulting relevance judgment, but the dynamics of topicality perception and novelty perception occur at different paces.
Liquid chromatographic–mass spectrometry analysis and pharmacokinetic studies of a novel rabeprazole formulation, sterile powder for injection, in dogs and rats
Authors: Shao Feng , Sun Jianguo , Wang Guangji , Xie Haitang , Zhu Xiaoyan , Zhang Jingwei 
Published: March 2007

AbstractRabeprazole is among the most potent proton pump inhibitors (PPI) identified to date and it has been demonstrated that it is effective in such diseases as gastroesophageal reflux disease (GERD), duodenal ulcer and gastric ulcer. There is currently interest in developing a new formulation: rabeprazole sterile powder for injection (RSPI). This investigation was conducted to evaluate the preclinical pharmacokinetics of RSPI in rats and at the same time a comparative study was carried out in dogs between RSPI and Pariet® tablets using liquid chromatographic–mass spectrometry analysis.The liquid chromatographic–mass spectrometry method was first conducted and validated as being specific, and having accuracy, precision, sensitivity and a satisfactory recovery. After intravenous administration of RSPI (i.v.: 2, 6 and 18 mg/kg) to rats, no significant dose‐dependency was found in the CL (4.20–5.72 l/h/kg), Varead (0.94–1.32 l/kg), dose‐normalized AUC (197.20–245.82 µg/l*h based on 1 mg/kg) and t1/2 (p>0.05). In the dog, a randomized, open‐label, crossover experiment was carried out to show that the mean area under the plasma concentration‐time curve (AUC0–∞) after i.v. administration of RSPI was at least four times larger than that following oral administration of Pariet® tablet at an equivalent dose but the elimination half‐life of these two formulation was similar (p>0.05). The results showed that the pharmacokinetics of RSPI was linear (r2 = 0.98) in the dose range 2–18 mg/kg and the RSPI had a much higher AUC0–∞ and similar t1/2 values compared with the enteric‐coated tablet. Copyright © 2007 John Wiley & Sons, Ltd.
In vitro and in vivo comparative study of itraconazole bioavailability when formulated in highly soluble self‐emulsifying system and in solid dispersion
Authors: Park Mi‐Jin , Ren Shan , Lee Beom‐Jin 
Published: March 2007

AbstractA semisolid self‐emulsifying system (SES) of itraconazole consisting of oleic acid, polysorbate 80 and coajuvant (citric acid) was prepared by a hot‐melt technique and then compared with hydroxypropylmethylcellulose (HPMC) solid dispersion (SD) coated onto inert sugar spheres as a reference formulation for in vitro and in vivo disposition in rats. The optimal SES greatly increased dissolution rates in gastric (pH 1.2) and intestinal fluid (pH 6.8) by forming a microemulsion (150–250 nm), whereas that of SD was minimal. The tissue uptake of itraconazole from SES in whole intestine, liver and Peyer's patches of the rats was more favorable than that from SD and linearly increased as a function of administering dose. Interestingly, the uptake ratio of Peyer's patches relative to liver also increased linearly in the case of SES while that of SD was almost unchanged. After repeated dosing for 1 week, both SES and SD increased the areas of Peyer's patch region in intestinal tissues but no distinct histopathological damage of the intestine was observed except the hepatocytes. Due to the biopharmaceutical differences of SES in terms of efficient solubilization, easy dispersibility and higher lymphatic transport, the in vivo bioavailability of SES was about twice greater than that of SD in rats. Copyright © 2007 John Wiley & Sons, Ltd.
Application of the automated spatial surveillance program to birth defects surveillance data
Authors: Gardner Bennett R. , Strickland Matthew J. , Correa Adolfo 
Published: March 2007

AbstractBACKGROUND: Although many birth defects surveillance programs incorporate georeferenced records into their databases, practical methods for routine spatial surveillance are lacking. We present a macroprogram written for the software package R designed for routine exploratory spatial analysis of birth defects data, the Automated Spatial Surveillance Program (ASSP), and present an application of this program using spina bifida prevalence data for metropolitan Atlanta. METHODS: Birth defects surveillance data were collected by the Metropolitan Atlanta Congenital Defects Program. We generated ASSP maps for two groups of years that correspond roughly to the periods before (1994–1998) and after (1999–2002) folic acid fortification of flour. ASSP maps display census tract–specific spina bifida prevalence, smoothed prevalence contours, and locations of statistically elevated prevalence. We used these maps to identify areas of elevated prevalence for spina bifida. RESULTS: We identified a large area of potential concern in the years following fortification of grains and cereals with folic acid. This area overlapped census tracts containing large numbers of Hispanic residents. CONCLUSIONS: The potential utility of ASSP for spatial disease monitoring was demonstrated by the identification of areas of high prevalence of spina bifida and may warrant further study and monitoring. We intend to further develop ASSP so that it becomes practical for routine spatial monitoring of birth defects. Birth Defects Research (Part A), 2007. © 2007 Wiley‐Liss, Inc.
R‐spondin1—discovery of the long‐missing, mammalian female‐determining gene?
Authors: Wilhelm Dagmar 
Published: March 2007

AbstractUntil recently, sex determination in mammals has often been described as a male determination process, with male differentiation being the active and dominant pathway, and only in its absence is the passive female pathway followed. This picture has been challenged recently with the discovery that the gene encoding R‐spondin1 is mutated in human patients with female‐to‐male sex reversal.1 These findings might place R‐spondin1 in the exceptional position of being the female‐determining gene in mammals. In this review, possible roles of R‐spondin1 during sex determination as well as questions arising from this study will be discussed. BioEssays 29:314–318, 2007. © 2007 Wiley Periodicals, Inc.
Does genetic conflict drive rapid molecular evolution of nuclear transport genes in Drosophila?
Authors: Presgraves Daven C. 
Published: March 2007

AbstractThe Segregation Distorter (SD) system of Drosophila melanogaster is one the best‐characterized meiotic drive complexes known. SD gains an unfair transmission advantage through heterozygous SD/SD+ males by incapacitating SD+‐bearing spermatids so that virtually all progeny inherit SD. Segregation distorter (Sd), the primary distorting locus in the SD complex, is a truncated duplication of the RanGAP gene, a major regulator of the small GTPase Ran, which has several functions including the maintenance of the nucleocytoplasmic RanGTP concentration gradient that mediates nuclear transport. The truncated Sd‐RanGAP protein is enzymatically active but mislocalizes to the nucleus where it somehow causes distortion. Here I present data consistent with the idea that wild‐type RanGAP, and possibly other loci able to influence the RanGTP gradient, has been caught up in an ancient genetic conflict that predates the SD complex. The legacy of this conflict could include the unexpectedly rapid evolution of nuclear transport‐related proteins, the accumulation of chromosomal inversions, the recruitment of gene duplications, and the turnover of repetitive sequences in the centric heterochromatin. BioEssays 29:386–391, 2007. © 2007 Wiley Periodicals, Inc.
DNA replication and models for the origin of piRNAs
Authors: Bateman Jack R. , Wu Chao‐ting 
Published: March 2007

AbstractThe piRNA class of small RNAs are distinct from other small RNAs by their ∼26–31 nucleotide size, single‐strandedness and strand‐specificity as well as by the clustered arrangement of their origins. Here, we highlight how these features are reminiscent of the mechanisms of DNA replication, and then present three models suggesting that the origin of piRNAs may be mechanistically similar to key processes in DNA replication. BioEssays 29:382–385, 2007. © 2007 Wiley Periodicals, Inc.
Structural study of the zinc and cadmium complexes of a type 2 plant (Quercus suber) metallothionein: Insights by vibrational spectroscopy
Authors: Domènech Jordi , Tinti Anna , Capdevila Mercè , Atrian Silvia , Torreggiani Armida 
Published: March 2007

AbstractZn‐ and Cd‐complexes of Quercus suber metallothionein (QsMT) were obtained by in vivo‐synthesis, in order to obtain physiologically representative aggregates, and characterized by spectrometric and spectroscopic methods. The secondary structure elements and the coordination environments of the metal binding sites of the two aggregates were determined, as well as the main metal‐containing species formed. The results obtained from the analysis of the Raman and IR spectra reveal that these metal‐MT complexes predominantly contain β‐sheet elements (about 60%), whereas they lack α‐helices. These structural features slightly depend on the divalent metal bound. In particular, CdII binding to QsMT induces a slight increase of the β‐sheet percentage, as well as a decrease in β‐turn elements with respect to ZnII binding. Conversely, the in vivo capability of QsMT to inglobe metal and sulfide ions is metal‐depending. Spectroscopic vibrational data also confirm the presence of sulfide ligands in the metal clusters of both Zn‐ and Cd‐QsMT, while the participation of the spacer His residue in metal coordination was only found in Cd‐QsMT, in agreement with the CD results. Overall data suggest different coordination environments for ZnII and CdII ions in QsMT. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 240–248, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
β‐sheet folding of 11‐kDa fibrillogenic polypeptide is completely aggregation driven
Authors: Topilina Natalya I. , Ermolenkov Vladimir V. , Higashiya Seiichiro , Welch John T. , Lednev Igor K. 
Published: March 2007

AbstractA de novo polypeptide GH6[(GA)3GY(GA)3GE]8GAH6 (YE8) was designed and genetically engineered to form antiparallel β‐strands of GAGAGA repeats. Modulation of pH enables control of solubility, folding, and aggregation of YE8 by control of the overall polypeptide charge, a consequence of the protonation or deprotonation of the glutamic acid and histidine residues. YE8 exhibits all the major properties of a fibrillogenic protein providing an excellent model for detailed study of the fibrillation. At neutral pH, YE8 is soluble in disordered form, yet at pH 3.5 folds into a predominantly β‐sheet conformation that is fibrillogenic. Atomic force microscopy and transmission electron microscopy indicated the formation of fibrillar aggregates on well‐defined, hydrophobic surfaces. The β‐sheet folding of YE8 exhibited a lag phase that could be eliminated by seeding or stirring. The strong dependence of lag time on polypeptide concentration established the limiting step in aggregation as initiation of β‐sheet folding. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 261–264, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com