bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptivity with moving grids
Authors: Budd Chris J. , Huang Weizhang , Russell Robert D. 
Published: May 2009

In this article we surveyr-adaptive (or moving grid) methods for solving time-dependent partial differential equations (PDEs). Although these methods have received much less attention than theirh- andp-adaptive counterparts, particularly within the finite element community, we review the substantial progress that has been made in developing more robust and reliable algorithms and in understanding the basic principles behind these methods, and we give some numerical examples illustrative of the wide classes of problems for which these methods are suitable alternatives to the traditional ones.More specifically, we first examine the basic geometric properties of moving meshes in both one and higher spatial dimensions, and discuss the discretization process for PDEs on such moving meshes (both structured and unstructured). In particular, we consider the issues of mesh regularity, equidistribution, alignment, and associated variational methods. An overview is given of the general interpolation error analysis for a function or a truncation error on such an adaptive mesh. Guided by these principles, we show how to design effective moving mesh strategies. We then examine in more detail how these strategies can be implemented in practice. The first class of methods which we consider are based upon controlling mesh density and hence are called position-based methods. These make use of a so-called moving mesh PDE (MMPDE) approach and variational methods, as well as optimal transport methods. This is followed by an analysis of methods which have a more Lagrange-like interpretation, and due to this focus are called velocity-based methods. These include the moving finite element method (MFE), the geometric conservation law (GCL) methods, and the deformation map method. Finally, we present a number of specific types of examples for which the use of a moving mesh method is particularly effective in applications. These include scale-invariant problems, blow-up problems, problems with moving fronts and problems in meteorology. We conclude that, whilstr-adaptive methods are still in their relatively early stages of development, with many outstanding questions remaining, they have enormous potential and indeed can produce an optimal form of adaptivity for many problems.
Distributional determinants of household air pollution in China
Authors: PAPINEAU MAYA , AUNAN KRISTIN , BERNTSEN TERJE 
Published: May 2009

ABSTRACTSolid fuel burning in households is a leading health risk for people in developing countries. Several studies of indoor air pollution from solid fuels have analyzed the problem at the village and household level, but to design effective policies it is important to understand the large-scale socioeconomic drivers of household air pollution (HAP). Using county-level data covering all of China, we examine relationships between socioeconomic variables and ambient concentrations of PM and SO2 resulting from household energy use. Applying both non-parametric and parametric techniques, we find that income and education are robust determinants of HAP; structural characteristics affect the HAP turning points; and the poorest counties bear a disproportionate amount of total pollution, especially urban counties and counties located in the coastal provinces.
The utility of radioiodine uptake and thyroid scintigraphy in the diagnosis and management of hyperthyroidism
Authors: Okosieme O. E. , Chan D. , Price S. A. , Lazarus J. H. , Premawardhana L. D. K. E. 
Published: May 2009

SummaryBackground and objectives  The value and practice of thyroid radionuclide imaging in the diagnosis and management of hyperthyroidism is unsettled. Our objectives were to determine the influence of thyroid uptake and scintigraphy on the diagnosis of hyperthyroidism and the prediction of outcome following radioiodine therapy.Patients and design  We reviewed records and scintigraphic studies on 881 hyperthyroid patients carried out between 2000 and 2007. The agreement between the clinical and scintigraphic diagnosis was evaluated by kappa statistics. We determined the relationship between 4‐h 123I uptake and the outcome of 131I treatment in 626 patients. A multiple logistic regression model was used to determine variables influencing treatment outcome in 1 year.Results  The diagnostic categories were Graves’ disease (GD, n = 383), toxic multinodular goitre (n = 253), solitary toxic nodule (n = 164) and Graves’ disease coexisting with nodules (n = 81). The mean age of the patients was 58 ± 17, (M:F 160:721). There was good agreement between clinical and scintigraph diagnosis (K = 0·60, 95% CI 0·57–0·64, P < 0·001); and they were correctly matched in 74%; mismatched in 6% and indeterminate in 20% of patients. Treatment outcome was not associated with scintigraph diagnosis (P = 0·98) or radioiodine uptake at 4 h (P = 0·2). The use of antithyroid medications before treatment predicted treatment failure (odds ratio 2·0, 95% CI 1·2–3·6, P = 0·01).Conclusion  Thyroid scintigraphy and uptake studies did not influence diagnosis or treatment outcomes in most cases of hyperthyroidism. Our findings in this retrospective study do not justify their routine use. Selective scanning will reduce cost and exposure to radioisotopes without compromising diagnostic accuracy or treatment outcomes.
Climate‐related differences in the dominance of submerged macrophytes in shallow lakes
Authors: KOSTEN SARIAN , KAMARAINEN AMY , JEPPESEN ERIK , VAN NES EGBERT H. , PEETERS EDWIN T. H. M. , MAZZEO NÉSTOR , SASS LAURA , HAUXWELL JENNIFER , HANSEL‐WELCH NICOLE , LAURIDSEN TORBEN L. , SØNDERGAARD MARTIN , BACHMANN ROGER W. , LACEROT GISSELL , SCHEFFER MARTEN 
Published: May 2009

AbstractIt has been suggested that shallow lakes in warm climates have a higher probability of being turbid, rather than macrophyte dominated, compared with lakes in cooler climates, but little field evidence exists to evaluate this hypothesis. We analyzed data from 782 lake years in different climate zones in North America, South America, and Europe. We tested if systematic differences exist in the relationship between the abundance of submerged macrophytes and environmental factors such as lake depth and nutrient levels. In the pooled dataset the proportion of lakes with substantial submerged macrophyte coverage (> 30% of the lake area) decreased in a sigmoidal way with increasing total phosphorus (TP) concentration, falling most steeply between 0.05 and 0.2 mg L−1. Substantial submerged macrophyte coverage was also rare in lakes with total nitrogen (TN) concentrations above 1–2 mg L−1, except for lakes with very low TP concentrations where macrophytes remain abundant until higher TN concentrations. The deviance reduction of logistic regression models predicting macrophyte coverage from nutrients and water depth was generally low, and notably lowest in tropical and subtropical regions (Brazil, Uruguay, and Florida), suggesting that macrophyte coverage was strongly influenced by other factors. The maximum TP concentration allowing substantial submerged macrophyte coverage was clearly higher in cold regions with more frost days. This is in agreement with other studies which found a large influence of ice cover duration on shallow lakes' ecology through partial fish kills that may improve light conditions for submerged macrophytes by cascading effects on periphyton and phytoplankton. Our findings suggest that, in regions where climatic warming is projected to lead to fewer frost days, macrophyte cover will decrease unless the nutrient levels are lowered.
Solar UVB and warming affect decomposition and earthworms in a fen ecosystem in Tierra del Fuego, Argentina
Authors: ZALLER JOHANN G. , CALDWELL MARTYN M. , FLINT STEPHAN D. , BALLARÉ CARLOS L. , SCOPEL ANA L. , SALA OSVALDO E. 
Published: May 2009

AbstractCombined effects of co‐occurring global climate changes on ecosystem responses are generally poorly understood. Here, we present results from a 2‐year field experiment in aCarexfen ecosystem on the southernmost tip of South America, where we examined the effects of solar ultraviolet B (UVB, 280–315 nm) and warming on above‐ and belowground plant production, C : N ratios, decomposition rates and earthworm population sizes. Solar UVB radiation was manipulated using transparent plastic filter films to create a near‐ambient (90% of ambient UVB) or a reduced solar UVB treatment (15% of ambient UVB). The warming treatment was imposed passively by wrapping the same filter material around the plots resulting in a mean air and soil temperature increase of about 1.2 °C. Aboveground plant production was not affected by warming, and marginally reduced at near‐ambient UVB only in the second season. Aboveground plant biomass also tended to have a lower C : N ratio under near‐ambient UVB and was differently affected at the two temperatures (marginal UVB × temperature interaction). Leaf decomposition of one dominant sedge species (Carex curta) tended to be faster at near‐ambient UVB than at reduced UVB. Leaf decomposition of a codominant species (Carex decidua) was significantly faster at near‐ambient UVB; root decomposition of this species tended to be lower at increased temperature and interacted with UVB. We found, for the first time in a field experiment that epigeic earthworm density and biomass was 36% decreased by warming but remained unaffected by UVB radiation. Our results show that present‐day solar UVB radiation and modest warming can adversely affect ecosystem functioning and engineers of this fen. However, results on plant biomass production also showed that treatment manipulations of co‐occurring global change factors can be overridden by the local climatic situation in a given study year.
Influence of intracoronal bleaching agents on the ultimate strength and ultrastructure morphology of dentine
Authors: Cavalli V. , Shinohara M. S. , Ambrose W. , Malafaia F. M. , Pereira P. N. R. , Giannini M. 
Published: May 2009

AbstractObjective  To evaluate the effects of intracoronal bleaching on ultimate tensile strength (UTS) of sound and etched dentine and its ultrastructure morphology.Methodology  Bovine dentine specimens with (e) or without previous etching with 37% phosphoric acid for 15 s were used for the intracoronal bleaching experiments. Teeth were randomly assigned to five treatments (n = 10): (C) control – no bleaching, (SP) sodium perborate, (CP) 35% carbamide peroxide, (25% HP) 25% hydrogen peroxide and (35% HP) 35% hydrogen peroxide. Bleaching was performed four times within a 72 h interval and afterwards, dentine pulp chamber blocks were obtained. The blocks were sectioned in 0.7 mm‐thick slices and these were trimmed to reduce the inner dentine to a dumbbell shape with a cross‐sectional area of 0.8 mm2. Specimens were tested with the microtensile method (0.5 mm min−1) and data were analysed (two‐way anova‐Tukey test, P < 0.05). Additional teeth were prepared for transmission electron microscopy (TEM) to evaluate dentine ultramorphology.Results  The mean values of the UTS (SD) in MPa for sound dentine were: C = 48.3(8.5)a, SP = 34.6 (8.2)b, CP = 32.9 (8.9)b, 25% HP = 28.0(4.6)b, 35% HP = 26.4(6.6)b, and pre‐etched dentine: Ce = 38.9(13.8)a, SPe = 31.3 (9.3)ab, CPe = 28.4 (6.2)ab, 25% HPe = 30.0 (7.9)ab, 35% HPe =  19.9(4.6)b. Significant differences between the means are indicated by the letters. TEM observations exhibited demineralization areas for all bleaching treatments.Conclusion  Bleaching decreased dentine UTS after treatment. Pre‐etched not‐bleached dentine (Ce) presented UTS similar to pre‐etched bleached dentine, except for 35% HPe. The decrease of UTS of bleached dentine could be attributed to ultrastructural alterations such as loss of inorganic components.
Partial pulpotomy on caries‐free teeth using enamel matrix derivative or calcium hydroxide: a randomized controlled trial
Authors: Kiatwateeratana T. , Kintarak S. , Piwat S. , Chankanka O. , Kamaolmatyakul S. , Thearmontree A. 
Published: May 2009

AbstractAim  To compare the effect of enamel matrix derivative (EMD) and calcium hydroxide [Ca(OH)2] on exposed human pulp.Methodology  Fifteen pairs of human contralateral premolars were intentionally and partially pulpotomized. The exposed pulps were randomly capped with either EMDgel (Emdogain®) or a mix of Ca(OH)2 and sterile water. The subjects recorded pain or discomfort during the first 10 days and were also interviewed and examined by a blinded examiner at 1 day, 2 weeks, 3 and 6 months post‐operation. Periapical radiographs were taken prior to the operation, and 3 and 6 months post‐operation. After 6 months, the teeth were extracted and processed for histological evaluation. The data were described and analysed using McNemar test and Kaplan–Meier survival analysis.Results  The EMDgel‐treated teeth had significantly less tooth hypersensitivity than the Ca(OH)2‐treated teeth during the first 2 weeks (P = 0.031) but were not significantly different after 2 weeks (P = 0.125). No detectable periapical radiographic changes were observed in any teeth and radiographic evidence of dentine bridge formation from both groups were not significantly different during the follow‐up periods (P > 0.05). Histological evaluation demonstrated that the Ca(OH)2‐treated teeth had less inflammation and more dentine bridge formation than those in the EMDgel‐treated teeth.Conclusions  After 6 months, healthy pulps capped with Ca(OH)2 had more favourable results than counterparts capped with EMDgel. However, similar clinical and radiographic results were seen in both groups.
On the local applications of antibiotics and antibiotic‐based agents in endodontics and dental traumatology
Authors: Mohammadi Z. , Abbott P. V. 
Published: May 2009

AbstractAntibiotics are a valuable adjunctive to the armamentarium available to health professionals for the management of bacterial infections. During endodontic treatment and when managing trauma to the teeth, antibiotics may be applied systemically (orally and/or parenterally) or locally (i.e. intra‐dentally via irrigants and medicaments). Due to the potential risk of adverse effects following systemic application, and the ineffectiveness of systemic antibiotics in necrotic pulpless teeth and the periradicular tissues, the local application of antibiotics may be a more effective mode for delivery in endodontics. The aim of this article was to review the history, rationale and applications of antibiotic‐containing irrigants and medicaments in endodontics and dental traumatology. The search was performed from 1981 to 2008 and was limited to English‐language papers. The keywords searched on Medline were ‘Antibiotics AND endodontics’, ‘Antibiotics AND root canal irrigation’, ‘Antibiotics AND intra‐canal medicament’, ‘Antibiotics AND Dental trauma’ and ‘Antibiotics AND root resorption’. The reference section of each article was manually searched to find other suitable sources of information. It seems that local routes of antibiotic administration are a more effective mode than systemic applications. Various antibiotics have been tested in numerous studies and each has some advantages. Tetracyclines are a group of bacteriostatic antibiotics with antibacterial substantivity for up to 12 weeks. They are typically used in conjunction with corticosteroids and these combinations have anti‐inflammatory, anti‐bacterial and anti‐resorptive properties, all of which help to reduce the periapical inflammatory reaction including clastic‐cell mediated resorption. Tetracyclines have also been used as part of irrigating solutions but the substantivity is only for 4 weeks. Clindamycin and a combination of three antibiotics (metronidazole, ciprofloxacin and minocycline) have also been reported to be effective at reducing bacterial numbers in the root canal systems of infected teeth.
Comparative study of biocompatibility of newly developed calcium phosphate‐based root canal sealers on fibroblasts derived from primary human gingiva and a mouse L929 cell line
Authors: Khashaba R. M. , Chutkan N. B. , Borke J. L. 
Published: May 2009

AbstractAim  To determine biocompatibility of three calcium phosphate cement (CPC) sealers, and to compare the cytotoxic response of human gingival fibroblasts (HGF) and one mouse fibroblast cell line (L929) to these materials.Methodology  Monocalcium phosphate, calcium oxide and synthetic hydroxyapatite were combined with one of three aqueous solutions: modified polyacrylic acid, glass–ionomer liquid or 35% w/w polymethyl vinyl ether maleic acid to obtain Types I, IIa and III CPCs, respectively. Commercial Ca(OH)2 sealer was used as a control. The materials were packed into Teflon molds (5.5 × 3 mm), and cellular function was assessed using MTT assay. The specimens were placed immediately in contact with cells, then evaluated at (24 h, 1 week, 2 week, 3 week, 4 week, 5 week).Results  All materials showed significant cytotoxicity for both L929 and HGF cells at 24 h except for Type III. Type I was severely toxic initially, but improved significantly (P < 0.05) over the 5 week evaluation. Types II and Ca(OH)2 were both cytotoxic over the 5 weeks. Type III CPC was equivalent to Teflon the entire time. The results showed the same rank of cytotoxicity in both cultures. The cytotoxic response decreased in the order of Type II > Ca(OH)2 > Type I > Type III overtime. L929 cells were generally more sensitive than HGF cells to the calcium hydroxide‐based sealer (Acroseal).Conclusion  Types I and III have acceptable biologic properties for endodontic applications.
A 5‐year review of teeth filled with the noninstrumentation technology
Authors: Suter B. , Portmann P. , Lussi A. 
Published: May 2009

AbstractAim  The aim of this Case Series was to evaluate the radiographic quality of root fillings performed 5 years previously using the noninstrumentation technology (NIT)‐obturation method and to assess radiographically the outcome of these root canal treatments.Methodology  Seventeen patients requiring root canal treatment participated in this study and were re‐evaluated after 5 years. After instrumentation with K‐Flexofiles, Calcium‐Hydroxide inter‐appointment dressing, re‐entry and copious irrigation with NaOCl, the teeth were root filled using the NIT.Results  Immediately after obturation the root fillings were (−0.78 ± 0.11 mm) short when taking the radiographic apex as a reference point. After 60 months these values were −0.85 ± 0.11 mm. No statistical difference was found (P > 0.05). In the periapical region, PAI rating 1 and 2 increased from 20.1% to 75.6% after 60 months.Conclusions  • This prospective Case Series demonstrated the performance of the NIT‐obturation method in vivo.• Root canals filled by the reduced‐pressure method using sealer combined with gutta‐percha cones showed good radiographic quality.• Periapical healing after 5 years was comparable with conventional filling techniques.
A project management perspective on student's declarative commitments to goals established within asynchronous communication
Authors: Chiocchio F. , Lafrenière A. 
Published: May 2009

AbstractTeamwork and technology, even as people are seeing their increased use in organizations, are becoming important components of problem‐based learning in academic settings. Yet, fostering computer‐assisted teamwork is complex and time consuming. Knowing how and when to intervene would prove useful. This study draws from the field of project management to explore how students commit to project goals using collective asynchronous text‐based communication technology. Declarative commitments – goal‐orientated public, voluntary, explicit and non‐retractable messages comprised of a term, an objective and a focus – made by 34 teams during a four‐phase 13‐week project were analysed qualitatively and quantitatively. Qualitative results show that declarative commitments voluntarily and formally package information about project constraints into a relatively potent message about tasks, coordination and project completion. Team members' suggestions as to what should be carried out in the project and requests for help often preceded others' declarative commitments. As with persuasive communication (i.e. aimed at changing beliefs, attitudes and behaviours), declarative commitments were followed by demands for clarification, new declarative commitments, confirmations of upheld commitments and clear approvals of what was committed to. Looking at project progression from a broader perspective, quantitative analyses show that declarative commitments did partially mediate the relationship between frequencies of task issues and of task solutions. This was particularly pronounced in the mid‐point of the project, but it was not the case during the initial or final phases of the project. Taken together, these results suggest that teachers can facilitate computer‐assisted learning and project goal attainment by monitoring asynchronous electronic discussions, and by eliciting and structuring declarative commitments.
ANTI‐HSP60 and ANTI‐HSP70 antibody levels and micro/ macrovascular complications in type 1 diabetes: the EURODIAB Study
Authors: Gruden G. , Bruno G. , Chaturvedi N. , Burt D. , Pinach S. , Schalkwijk C. , Stehouwer C. D. , Witte D. R. , Fuller J. H. , Cavallo‐Perin P. ,   EURODIAB Prospective Complications Study Group
Published: May 2009

Abstract.Objectives.  The heat shock proteins 60 and 70 (HSP60, HSP70) play an important role in cytoprotection. Under stress conditions they are released into the circulation and elicit an immune response. Anti‐HSP60 and anti‐HSP70 antibody levels have been associated with cardiovascular disease. Type 1 diabetes is associated with a greatly increased risk of micro‐ and macrovascular complications. Therefore, we investigated whether anti‐HSP60 and anti‐HSP70 antibody levels were associated with micro‐ and macrovascular complications in type 1 diabetic patients.Design.  A cross‐sectional nested case‐control study from the EURODIAB Study of 531 type 1 diabetic patients was performed.Subjects.  Cases (n = 363) were defined as those with one or more complications of diabetes; control subjects (n = 168) were all those with no evidence of any complication. We measured anti‐HSP60 and anti‐HSP70 antibody levels and investigated their cross‐sectional associations with diabetic complications.Results.  Anti‐HSP70 antibody levels were significantly greater in control than in case subjects, whereas anti‐HSP60 antibody levels were similar in the two groups. In logistic regression analysis, anti‐HSP70 levels in the upper quartiles were associated with a 47% reduced odds ratio of micro/macrovascular complications, independently of conventional risk factors, markers of inflammation and endothelial dysfunction [odds ratio(OR) = 0.53, 95% confidence intervals(CI): 0.28–1.02].Conclusions.  In this large cohort of type 1 diabetic subjects, we found an independent and inverse association between serum anti‐HSP70 antibody levels and diabetic micro/macrovascular complications. This suggests that anti‐HSP70 antibody levels may be a novel marker of protection from chronic diabetic complications.