bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Steam Circulation Strategies for SAGD Startup
Authors: Yuan Jian-Yang , McFarlane Richard 
Published: January 2011

Summary
The impact of steam quality, circulation rate and pressure difference between the well pair during SAGD initialization using steam circulation was explored through the use of numerical simulations employing a discretized wellbore model. These operating parameters appear to affect uniformity of reservoir heating, occurrence of steam breakthrough and time required to establish communication between the well pair.
The simulation results indicate that, for the given tubing and liner sizes and reservoir properties, relatively lower circulation rates at high-steam quality are more favourable for faster initialization and development of uniform temperature between the horizontal well pair. At lower steam qualities, however, higher circulation rates appear more favourable. The use of high-steam quality in combination with high-circulation rates leads to slower rates of initialization, less uniform heating along the length of the wells and possibility of premature steam breakthrough at the heel. It was also found that having a higher steam quality in the lower well than in the upper well could lead to faster initialization and more uniform heating between the well pair. A small pressure difference, offsetting the natural hydraulic pressure (50 kPa), appears to be more favourable for faster and more uniform initialization.
Repeated Measures Semiparametric Regression Using Targeted Maximum Likelihood Methodology with Application to Transcription Factor Activity Discovery
Authors: Tuglus Catherine , van der Laan Mark J. 
Published: January 2011

In longitudinal and repeated measures data analysis, often the goal is to determine the effect of a treatment or aspect on a particular outcome (e.g., disease progression). We consider a semiparametric repeated measures regression model, where the parametric component models effect of the variable of interest and any modification by other covariates. The expectation of this parametric component over the other covariates is a measure of variable importance. Here, we present a targeted maximum likelihood estimator of the finite dimensional regression parameter, which is easily estimated using standard software for generalized estimating equations.The targeted maximum likelihood method provides double robust and locally efficient estimates of the variable importance parameters and inference based on the influence curve. We demonstrate these properties through simulation under correct and incorrect model specification, and apply our method in practice to estimating the activity of transcription factor (TF) over cell cycle in yeast. We specifically target the importance of SWI4, SWI6, MBP1, MCM1, ACE2, FKH2, NDD1, and SWI5.The semiparametric model allows us to determine the importance of a TF at specific time points by specifying time indicators as potential effect modifiers of the TF. Our results are promising, showing significant importance trends during the expected time periods. This methodology can also be used as a variable importance analysis tool to assess the effect of a large number of variables such as gene expressions or single nucleotide polymorphisms.
Primary Care-Specialist Collaboration in the Care of Patients with Chronic Kidney Disease
Authors: Diamantidis Clarissa Jonas , Powe Neil R. , Jaar Bernard G. , Greer Raquel Charles , Troll Misty U. , Boulware L. Ebony 
Published: January 2011

Summary

Background and objectives
Collaboration between primary care physicians (PCPs) and nephrologists in the care of patients with chronic kidney disease (CKD) is widely advocated, but physician preferences regarding collaboration are unknown. Physicians' desires to collaborate in the care of a hypothetical patient with CKD, their preferred content of collaboration, and their perceived barriers to collaboration were assessed.

Design, setting, participants, & measurements
A questionnaire describing the care of a hypothetical patient with progressive CKD was administered to a national sample of U.S. PCPs and nephrologists. Physician characteristics and attitudes associated with desires to collaborate were identified.

Results
Among 124 PCPs and 120 nephrologists, most physicians (85% PCPs versus 94% nephrologists) desired collaboration. Nephrologists were more likely than PCPs to prefer collaboration focus on predialysis/renal replacement therapy preparation and electrolyte management (73% versus 52% and 81% versus 46%, respectively). PCPs were more likely to desire collaboration if the hypothetical patient had diabetes and hypertension (versus hypertension alone), if they believed the care they provide helps slow CKD disease progression, and if they did not perceive health insurance as a barrier to nephrology referral (adjusted percentages [95% confidence interval]: 94% [80 to 98] versus 75% [reference]), 92% [75 to 98] versus 75% [reference], 42% [9 to 85] versus 88% [reference], respectively).

Conclusions
Most PCPs and nephrologists favored collaborative care for a patient with progressive CKD, but their preferred content of collaboration differed. Collaborative models that explicitly include PCPs in the care of patients with CKD may help improve patients' clinical outcomes.
Acute Kidney Injury and Increasing Nephrotoxic-Medication Exposure in Noncritically-Ill Children
Authors: Moffett Brady S. , Goldstein Stuart L. 
Published: January 2011

Summary

Background and objectives
Acute kidney injury (AKI) in hospitalized children results in increased patient morbidity and mortality. Nephrotoxic-medication exposure is a common cause of AKI. Currently, no data exist to quantify the risks of developing AKI for various nephrotoxic medications in children. The primary aim of the current study is to assess for a potential association between nephrotoxic medications and the risk of developing AKI in hospitalized noncritically ill children with no pre-existing renal insufficiency.

Design, setting, participants, & measurements
We performed a retrospective case-control study in pediatric hospitalized noncritically ill patients aged 1 day to 18 years. The cases were patients who developed AKI, as defined by the pediatric modified RIFLE (pRIFLE) criteria; patients without AKI served as controls and were matched by age category, gender, and disease state.

Results
561/1660 (33.8%) patients identified for inclusion had AKI (441 category “R,” 117 category “I,” three category “F”); 357 cases were matched with 357 controls. Patients with AKI had longer length of hospital stay and increased hospital costs. Patients with AKI had exposure to more nephrotoxic medications for a longer period of time compared with controls. Odds of exposure for at least one nephrotoxic medication was significant for development of AKI. Exposure to more nephrotoxic medications was associated with an increased risk of AKI.

Conclusions
Increasing exposure to three or more nephrotoxic medications places pediatric patients at greater risk of acute kidney injury with resultant increased hospital costs and patient morbidity.
Avifaunal diversity and water quality analysis of an inland wetland
Authors: Sonal Deshkar , Jagruti Rathod , Geeta Padate 
Published: January 2011

The key physical and chemical parameters of one of the major habitats for birds - the wetlands are known to influence congregation of migratory and resident species of birds. The present study deals with the interactions between these abiotic factors and bird diversity of one such pond in semiarid zone of Gujarat, India. The pond was visited twice in a month. During each visit waterfowl census was carried out and water samples were also collected to document changes in physico-chemical parameters over the seasons. The aggregation of birds in the area is mainly related to the increase in migratory population of birds during winter. The variations in bird aggregations as well as physico-chemical factors are discussed. Key Words: Abiotic factors; Gujarat; physico-chemical parameters; semi-arid zone; waterfowl; wetlandDOI: 10.3126/jowe.v4i0.4151Journal of Wetlands Ecology, (2010) Vol. 4, pp 1-32
Comparison of MR imaging and FDG-PET/CT in the differential diagnosis of benign and malignant vertebral compression fractures
Authors: Cho Won-Ik , Chang Ung-Kyu 
Published: January 2011

Object
Differentiation between malignant and benign vertebral compression fractures (VCFs) is important but sometimes difficult, especially in elderly cancer patients. The authors investigated the findings of MR imaging and FDG-PET/CT for the differentiation of VCFs.

Methods
Between 2007 and 2008, the authors evaluated and treated 102 VCFs in 96 patients. The final diagnosis, based on biopsy results or clinical follow-up, was benign fracture in 67 lesions in 65 patients and malignant fracture in 35 lesions in 31 patients. Magnetic resonance images were obtained in all patients, and FDG-PET/CT was performed in 17 patients in the benign fracture group and 20 in the malignant fracture group. The prevalence of 3 significant MR imaging findings (posterior cortical bulging, epidural mass formation, and pedicle enhancement) and the presence of radiotracer uptake on FDG-PET/CT were evaluated in the 2 groups. The maximum standardized uptake value (SUVmax) on FDG-PET/CT was compared between the 2 groups, and diagnostic threshold value was sought to confirm malignancy. The diagnostic accuracy of MR imaging and FDG-PET/CT was compared in the differentiation of malignant from benign VCFs.

Results
Posterior cortical bulging was seen in 26 (74%) of 35 malignant lesions and 30 (45%) of 67 benign ones, epidural mass formation in 27 (77%) of the malignant lesions and 25% of the benign ones, and pedicle enhancement in 30 (91%) of the 33 malignant lesions and 18 (39%) of the 46 benign ones evaluated with Gd-enhanced MR imaging. These differences were statistically significant for each feature. Sensitivity and specificity for predicting malignancy were, respectively, 74% and 55% for posterior cortical bulging, 77% and 74% for epidural mass formation, and 90% and 61% for pedicle enhancement. Simultaneous occurrence of 3 significant features was found in 21 (64%) of the 33 malignant and 8 (17%) of the 46 benign lesions for which complete MR imaging data were available and showed sensitivity of 64% and specificity of 83%. The presence of radiotracer uptake on FDG-PET/CT was seen in all 20 (100%) of the 20 malignant lesions and 12 (71%) 17 of the benign lesions evaluated by FDG-PET/CT and showed a sensitivity of 100% and specificity of 29%. There was a significant difference in mean (± SD) SUVmax for the malignant (6.29 ± 3.50) and benign (2.38 ± 1.90) lesions (p < 0.001). The most reliable threshold for SUVmax was found to be 4.25, which yielded a sensitivity of 85% and a specificity of 71%.

Conclusions
When MR imaging findings are equivocal, FDG-PET/CT can be considered as an adjunctive diagnostic method for differentiating malignant from benign VCFs. In comparison with MR imaging, FDG-PET/CT showed slightly higher sensitivity and lower specificity.
Response to intracranial hypertension treatment as a predictor of death in patients with severe traumatic brain injury
Authors: Farahvar Arash , Gerber Linda M. , Chiu Ya-Lin , Härtl Roger , Froelich Matteus , Carney Nancy , Ghajar Jamshid 
Published: January 2011

Object
The normalization of increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) is assumed to limit secondary brain injury and improve outcome. Despite evidence-based recommendations for monitoring and treatment of elevated ICP, there are few studies that show an association between response to ICP-directed therapeutic regimens and adjusted mortality rate. This study utilizes a large prospective database to examine the effect of response to ICP-lowering therapy on risk of death within the first 2 weeks of injury in patients who sustained TBI and are older than 16 years.

Methods
The current study is based on 1426 patients with severe TBI (Glasgow Coma Scale [GCS] score < 9) of whom 388 were treated for elevated ICP (> 25 mm Hg) between 2000 and 2008 at 22 trauma centers enrolled in a New York State quality improvement program. This prospectively collected database also contains information including age, admission GCS score, pupillary status, CT scanning parameters, and hypotension, which are all known early prognostic indicators of death. Treatment of elevated ICP consisted of administration of mannitol, hypertonic saline, barbiturates, and/or drainage of CSF or decompressive craniectomy. The factors predicting ICP response to treatment and predicting death at 2 weeks were evaluated using logistic regression analyses.

Results
Increasing age and fewer hours of elevated ICP on Day 1 were found to be significant predictors (p = 0.001 and 0.0003, respectively) of a positive response to treatment. Response to ICP-lowering therapy (p = 0.03), younger age (p < 0.0001), fewer hours of elevated ICP (p < 0.0001), and absence of arterial hypotension on Day 1 (p = 0.001) significantly predicted reduced risk of death.

Conclusions
Patients who responded to ICP-lowering treatment had a 64% lower risk of death at 2 weeks than those who did not respond after adjusting for factors that independently predict risk of death.
Technique and outcome of endoscopy-assisted microscopic extended transsphenoidal surgery for suprasellar craniopharyngiomas
Authors: Kim Eui Hyun , Ahn Jung Yong , Kim Sun Ho 
Published: January 2011

Object
The transcranial approach has been the standard technique for removal of craniopharyngiomas for several decades. However, many reports of successful suprasellar craniopharyngioma removal accomplished using extended transsphenoidal surgery (TSS) have recently been published. In the present study, the authors describe their technique and the outcomes of removal of suprasellar craniopharyngiomas aided by the use of an operating microscope and an endoscope concurrently during extended TSS.

Methods
Between 1999 and 2008, 18 patients with suprasellar craniopharyngiomas underwent TSS. Tumors that adhered to the optic nerve were safely dissected, and fine perforating vessels were precisely preserved with the aid of a magnified, detailed microscopic view. Portions of the tumor that could not be properly visualized with the microscope were visualized with the endoscope.

Results
Total resection was achieved in all patients, and all visual symptoms improved. Preoperative hypopituitarism improved in 2 patients but persisted postoperatively in 15 patients (hormonal outcome was not available in 1 patient). Diabetes insipidus was present in 16 patients postoperatively. Cerebrospinal fluid leakage developed in 3 patients in the conventional fascia lata graft group, whereas no CSF leakage occurred after the dural suture technique with a fascia lata graft was introduced. This technique could be more precisely applied when using a microscopic view. Tumor recurrence was documented for 1 patient 2 years after surgery.

Conclusions
The authors achieved good results by using extended TSS for the removal of suprasellar craniopharyngiomas. Endoscopy-assisted microscopic extended TSS harnesses the advantages of a microscope as well as those of an endoscope. Surgeons should consider using the advantages of both surgical modalities to achieve the best result possible.
Aspectos religioso-políticos de la ideología de Espronceda : El Estudiante de Salamanca
Authors: Vasari Stephen 
Published: January 2011

La tendencia en la crítica al analizar El Estudiante de Salamanca ha sido de ver en esta obra tan sólo un tratamiento poético de una leyenda tradicional española, sin otro sentido especial. Únicamente el libro de Robert Marrast {Espronceda et son temps, París, Klinksieck, 1974) significa un cambio importante en esta actitud.
El presente artículo propone una interpretación radicalmente diferente : El Estudiante de Salamanca expresa de manera simbólico-alegórica y alusiva los conflictos ideológicos de la primera mitad del siglo diez y nueve, en especial los de los años de 1830 a 1840. El pensamiento que inspiró a Espronceda proviene esencialmente, casi exclusivamente, de Francia (el poeta vivió tres años — 1830 a 1833 — muy significativos del punto de vista religioso-políticos, en París). Los escritos de los pensadores, poetas y novelistas románticos de Francia, así como la extraordinaria figura del abate Lamennais y sus ideas, todo esto sirve de base a esta nueva interpretación de la mejor obra del gran poeta romántico español.
Ethnie, nationalité ou clan : des formes d'identité rivales ?
Authors: Blum Alain , Filipova Elena 
Published: January 2011

Les populations qui vivent sur le territoire de l'Altaï se configurent autour de formes identitaires multiples qui se combinent hors de toute hiérarchie. Une composante clanique, déterminée par une relation de parenté et des origines mythiques ; des composantes locales identifiées à travers des toponymes ; une identification ethno-culturelle des populations qui s'insère dans une démarche de description ethnographique ; une composante religieuse, complexe mais pas déterminante. Participe aussi à la définition de l'identité une « mémoire » élaborée, qui reconstruit le passé des tribus et leur histoire. Plusieurs découpages et rattachements administratifs de la région, qui ont été créés au cours du XXe siècle ont contribué à forger une composante politique, administrative et territoriale de l'identité, fondatrice de formes de nationalismes et de revendication identitaires spécifiques. Le facteur linguistique, enfin, défini par l'appartenance commune au monde turcophone implique la recherche d'une référence et d'une relation privilégiée aux autres peuples turcophones, extérieurs à la région.
Le recensement a réactivé un débat autour de ces différentes formes identitaires. Les groupes perçus auparavant, par l'ethnologie soviétique, comme ethnies secondaires (ou « sous-ethnies ») et qui ont obtenu, récemment, le statut de petits peuples indigènes, cherchent à le garder au nom des avantages politiques et financiers garantis par ce statut. Cette revendication a rencontré une forte opposition des élites du centre de la république de l'Altaï, qui craignaient une remise en cause de l'autonomie de cette unité administrative.
The cross-metathesis of methyl oleate with cis-2-butene-1,4-diyl diacetate and the influence of protecting groups
Authors: Behr Arno , Pérez Gomes Jessica 
Published: January 2011

Background: α,ω-Difunctional substrates are useful intermediates for polymer synthesis. An attractive, sustainable and selective (but as yet unused) method in the chemical industry is the oleochemical cross-metathesis with preferably symmetric functionalised substrates. The current study explores the cross-metathesis of methyl oleate (1) with cis-2-butene-1,4-diyl diacetate (2) starting from renewable resources and quite inexpensive base chemicals.Results: This cross-metathesis reaction was carried out with several phosphine and N-heterocyclic carbene ruthenium catalysts. The reaction conditions were optimised for high conversions in combination with high cross-metathesis selectivity. The influence of protecting groups present in the substrates on the necessary catalyst loading was also investigated.Conclusions: The value-added methyl 11-acetoxyundec-9-enoate (3) and undec-2-enyl acetate (4) are accessed with nearly quantitative oleochemical conversions and high cross-metathesis selectivity under mild reaction conditions. These two cross-metathesis products can be potentially used as functional monomers for diverse sustainable polymers.
Ankle-Dorsiflexion Range of Motion and Landing Biomechanics
Authors: Fong Chun-Man , Blackburn J. Troy , Norcross Marc F. , McGrath Melanie , Padua Darin A. 
Published: January 2011

AbstractContext:A smaller amount of ankle-dorsiflexion displacement during landing is associated with less knee-flexion displacement and greater ground reaction forces, and greater ground reaction forces are associated with greater knee-valgus displacement. Additionally, restricted dorsiflexion range of motion (ROM) is associated with greater knee-valgus displacement during landing and squatting tasks. Because large ground reaction forces and valgus displacement and limited knee-flexion displacement during landing are anterior cruciate ligament (ACL) injury risk factors, dorsiflexion ROM restrictions may be associated with a greater risk of ACL injury. However, it is unclear whether clinical measures of dorsiflexion ROM are associated with landing biomechanics.Objective:To evaluate relationships between dorsiflexion ROM and landing biomechanics.Design:Descriptive laboratory study.Setting:Research laboratory.Patients or Other Participants:Thirty-five healthy, physically active volunteers.Intervention(s):Passive dorsiflexion ROM was assessed under extended-knee and flexed-knee conditions. Landing biomechanics were assessed via an optical motion-capture system interfaced with a force plate.Main Outcome Measure(s):Dorsiflexion ROM was measured in degrees using goniometry. Knee-flexion and knee-valgus displacements and vertical and posterior ground reaction forces were calculated during the landing task. Simple correlations were used to evaluate relationships between dorsiflexion ROM and each biomechanical variable.Results:Significant correlations were noted between extended-knee dorsiflexion ROM and knee-flexion displacement (r  =  0.464, P  =  .029) and vertical (r  =  −0.411, P  =  .014) and posterior (r  =  −0.412, P  =  .014) ground reaction forces. All correlations for flexed-knee dorsiflexion ROM and knee-valgus displacement were nonsignificant.Conclusions:Greater dorsiflexion ROM was associated with greater knee-flexion displacement and smaller ground reaction forces during landing, thus inducing a landing posture consistent with reduced ACL injury risk and limiting the forces the lower extremity must absorb. These findings suggest that clinical techniques to increase plantar-flexor extensibility and dorsiflexion ROM may be important additions to ACL injury-prevention programs.