The effectiveness of Atraumatic Restorative Treatment versus conventional restorative treatment for permanent molars and premolars A critical assessment of existing systematic reviews and report of a new systematic review

Available for download at: http://mahara.qmul.ac.uk/view/view.php?id=16447Available for download at: http://mahara.qmul.ac.uk/view/view.php?id=16447Available for download at: http://mahara.qmul.ac.uk/view/view.php?id=16447Available for download at: http://mahara.qmul.ac.uk/view/view.php?id=16447Available for download at: http://mahara.qmul.ac.uk/view/view.php?id=16447Available for download at: http://mahara.qmul.ac.uk/view/view.php?id=16447Available for download at: http://mahara.qmul.ac.uk/view/view.php?id=16447Background: Atraumatic Restorative Treatment (ART) is the removal of caries using hand instruments and restoration of the resulting cavity using an adhesive restorative material. It was designed to restore teeth in communities without access to conventional dental clinics in poorer countries but has come to be used by dentists in the developed world too, as an alternative to conventional restorative treatment. Objectives: 1) to assess the scope and the methodological and reporting quality of existing systematic reviews of the effectiveness of ART compared to conventional restorative treatment; 2) to evaluate the effectiveness of ART compared to conventional treatment in permanent teeth with class I and II cavities. Methods: Searches: 1) for the assessment of existing systematic reviews: Electronic searches were conducted of OVID Medline, OVID Embase, The Cochrane Database of Systematic Reviews (CDSR), the Centre for Reviews and Dissemination (CRD) databases (DARE, NHSEED and HTA), Google Scholar, and the CNKI and CAOD Chinese databases; 2) for the systematic reviews of ART in permanent teeth: the above searches were supplemented by searches of the Cochrane Central Register of Controlled Trials (CENTRAL), LILAC, BBO, IMEAR (WHO Index Medicus for South East Region), WPRIM (WHO Western Pacific Region Index Medicus) and IndMed, Current Controlled Trials, Clinical Trials, OpenSIGLE, IADR conference abstracts and NLM Gateway. Hand searches were conducted of six dental journals known to have reported ART studies. References from retrieved systematic reviews, trials and other related papers were searched for additional reports. Authors were contacted. There were no language restrictions. Selection criteria: 1) for the assessment of existing systematic reviews: systematic reviews that compared ART to conventional treatment for the restoration of dental cavities; 2) for the systematic reviews of ART in permanent teeth: randomised controlled trials that compared ART using any adhesive material to conventional treatment using amalgam or any adhesive material Data collection: 1) for the assessment of existing systematic reviews: Reviews were selected and data was extracted by a single reviewer using a custom made data extraction sheet. Scope was assessed in terms of materials used, teeth and cavity type. Methodological quality was assessed using AMSTAR. Reporting quality was assessed using the PRISMA guidelines; 2) for the systematic reviews of ART in permanent teeth: reports of trials were screened and selected independently by two reviewers and data would have been extracted on a custom made data extraction sheet had there been eligible trials. Results: 1) for the assessment of existing systematic reviews: three systematic reviews were identified. Two of these were restricted to comparing ART with glass-ionomer to conventional treatment with amalgam; two allowed for inclusion of all cavity types in both deciduous and permanent teeth. None was of high methodological quality and reporting quality was good in one of the reviews only; 2) for the systematic reviews of ART in permanent teeth: no eligible trials were identified. Author’s conclusions: 1) existing systematic reviews do not have sufficient scope to allow for the inclusion of potentially eligible trials that would assess ARTs effectiveness and they have been of high to medium risk of bias; 2) it is disappointing that there are no properly conducted randomised controlled trials comparing ART to conventional treatment in class I and II cavities in the permanent dentition

What use are male hosts? The dynamics of maternally inherited bacteria showing sexual transmission or male killing

Closely related pathogens and parasites often have distinctly different strategies for transmission. In some cases, presence of one potential mode of transmission reduces the rate of or forbids another. In these cases, one can ask what the conditions are that favor the use of one mode of transmission over the other. We constructed a mathematical model to examine this issue for the case of maternally inherited endosymbionts of insects. Here, killing males (to enhance transmission through the female line by reducing sibling competition) and retaining live males as a vehicle for sexual transmission are mutually exclusive strategies. Our model indicates that sexual transmission of a maternally inherited parasite can exclude a male-killing strain, provided that a sexually transmitted infection can take over an infection by a male-killing strain either following exposure or when male killing is incomplete and sexual transmission is efficient. The presence of sexual transmission may also explain why secondary symbionts do not degrade toward the evolution of male killing but remain as "beneficial partners" to both male and female hosts. This stabilization may be fundamental to the evolution toward obligate mutualism, and thus it is important in the ecology and evolution of many arthropod groups

Investigating children\u27s multiplicative thinking: implications for teaching

Multiplicative thinking is a \u27big idea\u27 of mathematics that underpins much of the mathematics learned beyond the early primary school years. This article reports on a recent study that utilised an interview tool and a written quiz to gather data about children\u27s multiplicative thinking. Our research has so far revealed that many primary aged children have a procedural view of multiplicative thinking which we believe inhibits their progress. There are two aspects to this article. First, we present some aspects of the interview tool and written quiz, along with some of findings, and we consider the implications of those findings. Second, we present a key teaching idea and an associated task that has been developed from our research. The main purpose of the article is to promote the development of conceptual understanding of the multiplicative situation as opposed to the teaching of procedures. In doing so, we encourage the explicit teaching of the many connections within the multiplicative situation and between it and other \u27big ideas\u27 such as proportional reasoning and algebraic thinking

Glueball Spin

The spin of a glueball is usually taken as coming from the spin (and possibly the orbital angular momentum) of its constituent gluons. In light of the difficulties in accounting for the spin of the proton from its constituent quarks, the spin of glueballs is reexamined. The starting point is the fundamental QCD field angular momentum operator written in terms of the chromoelectric and chromomagnetic fields. First, we look at the restrictions placed on the structure of glueballs from the requirement that the QCD field angular momentum operator should satisfy the standard commutation relationships. This can be compared to the electromagnetic charge/monopole system, where the quantization of the field angular momentum places restrictions (i.e. the Dirac condition) on the system. Second, we look at the expectation value of this operator under some simplifying assumptions.Comment: 11 pages, 0 figures; added references and some discussio

Transcriptional coupling of neighbouring genes and gene expression noise: evidence that gene orientation and non-coding transcripts are modulators of noise

For some genes, notably essential genes, expression when expression is needed is vital hence low noise in expression is favourable. For others noise is necessary for coping with stochasticity or for providing dice-like mechanisms to control cell fate. But how is noise in gene expression modulated? We hypothesise that gene orientation may be crucial, as for divergently organized gene pairs expression of one gene could affect chromatin of a neighbour thereby reducing noise. Transcription of antisense non-coding RNA from a shared promoter is similarly argued to be a noise-reduction mechanism. Stochastic simulation models confirm the expectation. The model correctly predicts: that protein coding genes with bi-promoter architecture, including those with a ncRNA partner, have lower noise than other genes; divergent gene pairs uniquely have correlated expression noise; distance between promoters predicts noise; ncRNA divergent transcripts are associated with genes that a priori would be under selection for low noise; essential genes reside in divergent orientation more than expected; bi-promoter pairs are rare subtelomerically, cluster together and are enriched in essential gene clusters. We conclude that gene orientation and transcription of ncRNAs, even if unstable, are candidate modulators of noise levels

Annotated Bibliography of Generic Commodity Promotion Research (Revised)

A.E. Res. 91-

Improving measurements of SF6 for the study of atmospheric transport and emissions

Sulfur hexafluoride (SF6) is a potent greenhouse gas and useful atmospheric tracer. Measurements of SF6 on global and regional scales are necessary to estimate emissions and to verify or examine the performance of atmospheric transport models. Typical precision for common gas chromatographic methods with electron capture detection (GC-ECD) is 1–2%. We have modified a common GC-ECD method to achieve measurement precision of 0.5% or better. Global mean SF6 measurements were used to examine changes in the growth rate of SF6 and corresponding SF6 emissions. Global emissions and mixing ratios from 2000–2008 are consistent with recently published work. More recent observations show a 10% decline in SF6 emissions in 2008–2009, which seems to coincide with a decrease in world economic output. This decline was short-lived, as the global SF6 growth rate has recently increased to near its 2007–2008 maximum value of 0.30±0.03 pmol mol−1 (ppt) yr−1 (95% C.L.)