bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuum and Discrete Initial-Boundary Value Problems and Einstein’s Field Equations
Authors: Sarbach Olivier , Tiglio Manuel 
Published: April 2013

AbstractMany evolution problems in physics are described by partial differential equations on an infinite domain; therefore, one is interested in the solutions to such problems for a given initial dataset. A prominent example is the binary black-hole problem within Einstein’s theory of gravitation, in which one computes the gravitational radiation emitted from the inspiral of the two black holes, merger and ringdown. Powerful mathematical tools can be used to establish qualitative statements about the solutions, such as their existence, uniqueness, continuous dependence on the initial data, or their asymptotic behavior over large time scales. However, one is often interested in computing the solution itself, and unless the partial differential equation is very simple, or the initial data possesses a high degree of symmetry, this computation requires approximation by numerical discretization. When solving such discrete problems on a machine, one is faced with a finite limit to computational resources, which leads to the replacement of the infinite continuum domain with a finite computer grid. This, in turn, leads to a discrete initial-boundary value problem. The hope is to recover, with high accuracy, the exact solution in the limit where the grid spacing converges to zero with the boundary being pushed to infinity.The goal of this article is to review some of the theory necessary to understand the continuum and discrete initial boundary-value problems arising from hyperbolic partial differential equations and to discuss its applications to numerical relativity; in particular, we present well-posed initial and initial-boundary value formulations of Einstein’s equations, and we discuss multi-domain high-order finite difference and spectral methods to solve them.
Efficacy of preparation solutions and cleansing techniques on contamination of the skin in foot and ankle surgery
Authors: Yammine K. , Harvey A. 
Published: April 2013

We report a systematic review and meta-analysis of published randomised and quasi-randomised trials evaluating the efficacy of pre-operative skin antisepsis and cleansing techniques in reducing foot and ankle skin flora. The post-preparation culture number (Post-PCN) was the primary outcome. The data were evaluated using a modified version of the Cochrane Collaboration’s tool. We identified eight trials (560 participants, 716 feet) that met the inclusion criteria. There was a significant difference in the proportions of Post-PCN between hallux nailfold (HNF) and toe web spaces (TWS) sites: 0.47 vs 0.22, respectively (95% confidence interval (CI) 0.182937 to 0.304097; p < 0.0001). Meta-analyses showed that alcoholic chlorhexidine had better efficacy than alcoholic povidone-iodine (PI) at HNF sites (risk difference 0.19 (95% CI 0.08 to 0.30); p = 0.0005); a two-step intervention using PI scrub and paint (S& P) followed by alcohol showed significantly better efficacy over PI (S& P) alone at TWS sites (risk difference 0.13 (95% CI 0.02 to 0.24); p = 0.0169); and a two-step intervention using chlorhexidine scrub followed by alcohol showed significantly better efficacy over PI (S& P) alone at the combined (HNF with TWS) sites (risk difference 0.27 (95% CI 0.13 to 0.40); p < 0.0001). No significant difference was found between cleansing techniques. Cite this article: Bone Joint J 2013;95-B:498–503.
Risk of Pneumonia in Elderly Nursing Home Residents Using Typical Versus Atypical Antipsychotics
Authors: Aparasu Rajender R , Chatterjee Satabdi , Chen Hua 
Published: April 2013

BACKGROUND Antipsychotic medications are extensively used in nursing homes for management of behavioral and psychiatric disorders in the elderly. Prior research suggests that pneumonia is one of the common causes of anti psychotic-related mortality in this population. None of the studies compared typical and atypical antipsychotics with respect to pneumonia. OBJECTIVE To examine the risk of pneumonia with use of typical versus atypical antipsychotics in dual eligible elderly nursing home residents. METHODS The study involved a retrospective cohort design matched on propensity score using Medicare and Medicaid Analytical eXtract data from 4 US states. The study population included all elderly dual eligible (Medicaid and Medicare) nursing home residents (aged ≥65 years) who initiated antipsychotics any time between July 1, 2001, and December 31, 2003. The risk of pneumonia during the 6-month follow-up period was modeled using a Cox proportional model and extended Cox hazard model stratified on matched pairs based on propensity score, using atypical agents as the reference category. RESULTS Analysis of Medicaid-Medicare data revealed that there were 49,904 new antipsychotic (46,293 atypical and 3611 typical) users in the unmatched cohort and 7218 (3609 atypical and 3609 typical) users in the matched cohort. The unadjusted rate of pneumonia was 8.17% (4.61 events per person year) for atypical users and 5.21% (5.21 events per person year) for typical users. The results of Cox regression (average hazard ratio [HR] 1.24; 95% CI 0.94–1.64) and extended regression (<50 days: HR 1.17, 95% CI 0.83–1.66; and 50–180 days: HR 1.36, 95% CI 0.87–2.14) suggest that there was no significant difference in the risk of pneumonia among typical and atypical users. CONCLUSIONS The study found no differential risk of pneumonia between typical versus atypical antipsychotic use in dual eligible nursing home residents. Given the differential risk of mortality with typical and atypical antipsychotic use in nursing homes, more research is needed to evaluate other contributory factors of mortality with respect to these 2 antipsychotic classes.
Effect of the UGT1A1*28 Allele on Unconjugated Hyperbilirubinemia in HIV-Positive Patients Receiving Atazanavir: A Systematic Review
Authors: Culley Celia L , Kiang Tony KL , Gilchrist Samuel E , Ensom Mary HH 
Published: April 2013

OBJECTIVE To systematically examine the literature assessing the effect of uridine 5′-diphospho-glucuronosyltransferase (UGT) 1A1*28 genetic polymorphisms on atazanavir-associated hyperbilirubinemia. DATA SOURCES MEDLINE (1948–November 2012), EMBASE (1980–November 2012), International Pharmaceutical Abstracts (1970–November 2012), Google, and Google Scholar were searched using combinations of the following terms: glucuronosyltransferase, glucuronosyltransferase 1A1, atazanavir, atazanavir plus ritonavir, or polymorph$. The reference lists of all identified articles were manually searched. STUDY SELECTION AND DATA EXTRACTION Studies were included if at least 1 group of patients received atazanavir therapy and assessed the effect of UGT1A1*28 variants on bilirubin concentrations or atazanavir discontinuation rates. The quality of each study was ranked according to the US Preventive Services Task Force 1996 classification system. Information extracted included study design, baseline characteristics, treatment regimens, UGT1A1*28 genotype frequencies, bilirubin concentrations, incidence of hyperbilirubinemia, and atazanavir discontinuation rates. DATA SYNTHESIS Our search produced 12 studies, of which 9 were included (6 full manuscripts [level II-2], 2 abstracts, and 1 letter to the editor [level III]). Reported UGT1A1*28 homozygote genotype frequencies (0.8–23.8%) were in general agreement with the literature for the diverse ethnic population captured in the 9 studies. An association between the incidence of hyperbilirubinemia and UGT1A1*28 genotype (homozygotes > heterozygotes > wild-type) was demonstrated in all studies that reported such data (6 of 9 studies). However, the calculated positive predictive value for homozygosity and hyperbilirubinemia from pooled data was low (40.3%). Only 2 studies (levels II-2 and III) reported rates of atazanavir discontinuation due to hyperbilirubinemia and showed some positive correlation with presence of the UGT1A1*28 allele. CONCLUSIONS Based on the available evidence, homozygosity of the UGT1A1*28 allele does not strongly predict the incidence of severe hyperbilirubinemia. Thus, until large, prospective trials demonstrate otherwise, UGT1A1*28 testing does not appear to provide additional information to aid clinical decision-making when initiating atazanavir treatment in HIV-infected patients.
Novel Targets in the Treatment of Advanced Melanoma: New First-Line Treatment Options
Authors: Culos Kathryn A , Cuellar Sandra 
Published: April 2013

OBJECTIVE To discuss the clinical efficacy and safety of ipilimumab, vemurafenib, and investigational agents for the treatment of unresectable stage III and stage IV melanoma and define current strategies of first-line treatment selection. DATA SOURCES Literature was accessed through MEDLINE and International Pharmaceutical Abstracts (1970–November 2012) using the terms melanoma, metastatic melanoma, ipilimumab, vemurafenib, dabrafenib, and trametinib. In addition, reference citations from publications identified were reviewed. STUDY SELECTION AND DATA EXTRACTION All articles published in English identified from the data sources were evaluated. Studies and abstracts including more than 10 adult patients were included in the review. DATA SYNTHESIS Treatment options for unresectable stage III and IV melanoma are poor and have remained largely unchanged for the past 40 years. Two randomized Phase 3 clinical trials have demonstrated a significant survival benefit with the use of ipilimumab compared to a melanoma vaccine (10.1 vs 6.4 months; p = 0.003) and compared to dacarbazine (11.2 months, 95% CI 9.4–13.6 vs 9.1 months, 95% CI 7.8–10.5). Additionally, long-term follow-up has revealed cases of durable responses of greater than 3 years. Response rates of 50% and greater have been described in vemurafenib-treated patients (1 Phase 1, 1 Phase 2, and 1 Phase 3 randomized trial), although duration of response has not been fully determined. Both new agents possess unique toxicity profiles including immune-related adverse events with ipilimumab and secondary cutaneous cancers reported with vemurafenib use. CONCLUSIONS Treatment strategies have changed for patients with advanced melanoma with the use of ipilimumab and vemurafenib as first-line agents. Increased clinical experience and further published data with these and investigational agents will guide the development of treatment algorithms outlining optimal drug selection and sequencing as well as improve management of their novel adverse events.
Optimal Well Placement of Usari 37B using Dynamic Data, a Material Balance Model and Simulation Results
Authors: Onwude R. J. , Obasanjo O. , Udoh E. , Ajayi O. , Brock W. R. , Chen L. 
Published: April 2013

Abstract
The Usari Intermediate reservoirs field study completed in 2006 identified several significant opportunities. One of these, a drillwell opportunity in the 5-US reservoir, carried a substantial uncertainty in remaining oil volumes and thus, economic viability. No penetration existed to allow confirmation of the oil column thickness or position prior to drilling.
Material balance and numerical simulation were used to estimate the current OWC. The varied results from material balance, numerical simulation and geological evaluation formed the range of outcomes to optimally place the pilot hole and horizontal landing section to maximize recovery.
A pilot hole was drilled to intersect the range 7147' to 7190' of possible OWC depths. The OWC was found to be very close to the most likely contact scenario. Subsequently, the producing section was landed at the optimum location for maximum recovery. This led to a successful drillwell with an initial rate &gt;8.5 kBD.
This paper will focus on how the uncertainty surrounding the remaining oil volume was addressed to obtain a successful drillwell.
Controlled Hydraulic Fracturing of Naturally Fractured Shales - A Case Study in the Marcellus Shale Examining How to Identify and Exploit Natural Fractures
Authors: Ciezobka Jordan , Salehi Iraj 
Published: April 2013

Abstract
This case study will illustrate how natural fractures were identified in real time through analysis of surface pumping parameters and confirmed with microseismic data and multiple production logs. Furthermore, subsurface natural fracture distribution will be examined in an approximately 1 square mile area using microseismic and production data. Additionally, gas shows from mud logs will be examined and correlated to production. Finally, methods for real-time fracture optimization will be explored based on natural fracture identification through analysis of fracturing parameters along the horizontal wellbore.
It is well known in the oil and gas industry that natural fractures, either open or prone to opening during hydraulic fracturing, greatly improve hydrocarbon production in tight sand and shale reservoirs. There are many techniques available to identify natural fractures; including image logs, mud logs, G-function analysis leading to pressure dependent leakoff (PDL), core analysis, and many more. However, these techniques have many limitations when used for optimizing the interaction of hydraulic fractures with natural fractures to create a complex fracture network. The limitations result from small sample size when using core analysis, inaccurate or unpredictable measurements from mud logs; or in the case of horizontal image logs, they are extremely costly and uneconomical to run regularly. Recent research related to subcritical index testing has shown that subterranean natural fractures manifest themselves in clusters that are not uniformly distributed along a horizontal wellbore. Therefore, it would be advantageous to gain insight into natural fracture occurrence and distribution before designing the fracturing program and then positively identify natural fracture clusters along the horizontal wellbore in real time and optimize hydraulic fracturing parameters on-the-fly.
Interfacial Nanoleakage and Bonding of Self-Adhesive Systems Cured with a Modified-Layering Technique to Dentin of Weakened Roots
Authors: Mobarak E , Seyam R 
Published: April 2013

SUMMARY

Objective
The purpose of the study was to evaluate the nanoleakage and bond strength of different self adhesive systems cured with a modified-layering technique (MLT) to dentin of weakened roots.

Methods
Twenty-one maxillary incisors were decoronated and then root canals were instrumented and obturated with the cold lateral compaction technique. Weakened roots were simulated by flaring root canals until only 1 mm dentin thickness remained. Teeth were distributed into three groups. The canals were backfilled with Vertise Flow (VF group), a self-adhering system, following a modified-layering technique using two light-transmitting posts, sizes 6 and 3. DT Light Post size 2 was cemented using the same material. Remaining roots were prepared and cured in the same way as the VF group. However, in the TS/MF group, Clearfil Tri-S Bond (TS) adhesive and Clearfil Majesty Flow (MF) composite were used, while in the ED/PF group, ED primer II (ED)/Panavia F2.0 (PF) were used. After one week of storage, each root was sectioned to obtain six slices (two slices from each root third: coronal, middle and apical) of 0.9 ± 0.1 mm thickness. Interfacial nanoleakage expression was analyzed using a field emission scanning electron microscope (FEG-SEM), and the micro push-out bond strength (μPOBS) was measured at different root regions. Modes of failure were also determined using SEM. Data were statistically analyzed using two-way analysis of variance with repeated measures and Tukey post hoc test (p≤0.05).

Results
With MLT, all adhesive systems showed nanoleakage. For μPOBS, there was a statistically significant effect for adhesive systems (p&lt;0.001) but not for root region (p&lt;0.64) or for their interaction (p=0.99). Tukey post hoc test revealed that the bond strength of the VF group was significantly higher than the TS/MF and ED/PF groups for all root regions.

Conclusion
All of the tested self-adhesive systems cured using MLT had slight nanoleakage and were not sensitive to root regional differences. Self-adhering systems had higher bond strength than self-etch adhesives.
Physical Property Evaluation of Four Composite Materials
Authors: Chang M , Dennison J , Yaman P 
Published: April 2013

SUMMARY

Purpose
The purpose of this study was to evaluate the physical properties of current formulations of composite resins for polymerization shrinkage, surface hardness, and flexural strength. In addition, a comparison of Knoop and Vickers hardness tests was made to determine if there was a correlation in the precision between the two tests.

Materials and Methods
Four composite resin materials were used: Filtek LS (3M-ESPE), Aelite LS (Bisco), Kalore (GC America), and Empress Direct (Ivoclar). Ten samples of each composite (shade Vita A2) were used. Polymerization shrinkage was measured with the Kaman linometer using 2-mm-thick samples, cured for 40 seconds and measured with digital calipers for sample thickness. Surface microhardness samples were prepared (2-mm thick × 12-mm diameter) and sequentially polished using 600-grit silicone carbide paper, 9 μm and 1 μm diamond polishing solutions. After 24 hours of dry storage, Knoop (200 g load, 15 seconds dwell time) and Vickers (500 g load, 15 seconds dwell time) hardness tests were conducted. Flexural strength test samples (25 × 2 × 2 mm) were stored in 100% relative humidity and analyzed using a three-point bending test with an Instron Universal Testing Machine (Instron 5565, Instron Corp) applied at a crosshead speed of 0.75 ± 0.25 mm/min. Maximum load at fracture was recorded. One-way analysis of variance and Tukey multiple comparison tests were used to determine significant differences in physical properties among materials.

Results
Filtek LS had significantly lower shrinkage (0.45 [0.39] vol%). Aelite LS demonstrated the greatest Knoop surface hardness (114.55 [8.67] KHN), followed by Filtek LS, Kalore, and Empress Direct (36.59 [1.75] KHN). Vickers surface hardness was significantly greater for Aelite LS (126.88 [6.58] VH), followed by Filtek LS, Kalore, and Empress Direct (44.14 [1.02] VH). Flexural strength (MPa) was significantly higher for Aelite LS and Filtek LS (135.75 [17.35]; 129.42 [9.48]) than for Kalore and Empress Direct (86.84 [9.04]; 92.96 [9.27]). There is a strong correlation between results obtained using Knoop and Vickers hardness tests (r=0.99), although Vickers values were significantly greater for each material.

Conclusion
Results suggest that Aelite LS possesses superior hardness and flexural strength, while Filtek LS has significantly less shrinkage compared with the other composites tested.
Effect of a Chlorhexidine-containing Adhesive on Dentin Bond Strength Stability
Authors: Sabatini C 
Published: April 2013

SUMMARY

Purpose:
The present study aimed to investigate a novel adhesive system containing 0.2% chlorhexidine digluconate (CHX) for its ability to improve the stability of the adhesive interface compared with the use of 2% CHX as a therapeutic primer. Furthermore, the study aimed to confirm the inhibitory properties of these CHX concentrations (0.2% and 2.0%) on dentin matrix metalloproteinase activity by gelatin zymography.

Methods:
Superficial dentin substrate for bonding was obtained from 120 non-carious human molars. A conventional adhesive Peak LC Bond and a CHX-containing adhesive Peak Universal Bond were used either in combination with 35% phosphoric acid (etch-and-rinse approach) or with self-etching primer (self-etch approach) for evaluation of the variables CHX treatment (2.0% therapeutic primer and 0.2% adhesive), adhesive approach (etch-and-rinse and self-etch), and storage time (24 hours and six months). A bonding jig was used to fabricate composite cylinders, which were stored for either 24 hours or six months, after which shear bond strength (SBS) was evaluated using a notched-edge testing device. A three-way analysis of variance and a Student t-test with a significance level of p&lt;0.05 were used to analyze the data. Extracts from concentrated demineralized human dentin powder were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and incubated in the presence of 0.2% and 2.0% CHX.

Results:
No significant effect of CHX treatment, adhesive approach, storage time variables, or their interactions on mean SBS was demonstrated (p&lt;0.05). No significant difference between the control and the CHX-treated groups was detected for either adhesive technique at 24 hours or six months (p&lt;0.05). No significant variation in mean SBS was detected after six months of storage (p&lt;0.05). Zymographic analysis revealed bands of enzymatic activity for the group demineralized with phosphoric acid and complete inhibition of gelatinolytic activity for the groups treated with 0.2% and 2.0% CHX.

Conclusions:
CHX demonstrated inhibition of dentin proteolytic activity. However, when CHX was incorporated into a commercially available adhesive or used as a therapeutic primer, no difference in bond strength was observed at baseline or after six months of storage relative to the control group without CHX.
Technology-Based Music Classes in High Schools in the United States
Authors: Dammers Richard J. 
Published: April 2013

AbstractThe purpose of this study was to determine the extent to which comprehensive public high schools in the United States offer music classes that are technology-based, and to describe the nature of these classes. In the first phase of the study, principals from 10% of comprehensive public high schools in the United States (n = 1830) were surveyed regarding the technology-based music offerings of their high schools. Of the respondents (n = 528), 14% indicated that their schools offered technology-based music classes. Responses varied between geographic region and community type, with suburban high schools in the Northeast being most likely to offer these classes. Sixty-six percent of principals viewed technology-based music classes as a positive offering, and 56% of respondents from schools without these classes felt it would be possible to offer such a course. Music technology teachers (n = 58), identified by their principals, were sent a follow-up survey. Their responses (n = 29) indicated that these classes were generally designed for, and taken by, nontraditional music students, and that these classes had a broad range of curricular materials and objectives. Sixty-seven percent of these classes were initiated in the past ten years, and many were created by individual music teachers.
Les Sourds ne gesticulent pas, ils « signent »
Authors: Gaucher Charles 
Published: April 2013

Réfléchir sur la spécificité langagière sourde et au sentiment identitaire qui l’accompagne, c’est d’abord et avant tout interroger le sens commun qui veut que les Sourds gesticulent pour communiquer. Pourtant, les Sourds ont une langue qui ne se résume pas à un ensemble de mouvements substituant le geste à la parole ou à des adaptations de l’oralité à la gestualité. En fait, cette différence linguistique est plurielle : il existe des langues, qui véhiculent et sont véhiculées par autant de communautés identitaires sourdes. Le rapport des Sourds à ces langues se fait à travers une rhétorique ancrant paradoxalement la différence langagière sourde dans une caractéristique qui serait naturelle aux Sourds, une sorte d’inclination spontanée ramenant bien souvent la langue des signes à des gestes quasi instinctifs et souvent conçus comme innés. La langue des signes serait en quelque sorte une essence qui relie les Sourds entre eux. Le présent article propose d’explorer trois axes d’interprétation du lien entre langues des signes et corps sourds.