9,159 research outputs found
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
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
Zooming in on Justice: The Case for Virtual Bioethics Conferencing.
Jecker et al. discuss principles for international bioethics conferencing that purportedly seek to make bioethics more global in scope. In particular, they address what they have perceived to be Islamophobia within bioethics. We agree that anti-discrimination and inclusivity should serve as core commitments for the field. Yet, we also see the need for the conversation to be broadened. So, while Islamophobia may be a real occurrence within mainstream bioethics, it may be better understood within a context of generalized religious aversion. In response, we propose an alternative interpretation of their principles for international bioethics conferencing—no longer holding in-person bioethics conferences. Whilst this proposal has some limitations, they are outweighed by the benefits of widening participation for minority and disadvantaged groups, removing significant cost barriers to attendance, promoting epistemic justice, and resulting in significantly diminished environmental degradation. If an obligation to move towards virtual conferencing is rejected, conference organizers must propose an alternative ethical framework for conferencing that avoids the implications of Jecker et al’s framework. Personal preference is not a sufficiently weighty reason to continue organizing in-person bioethics conferences
The structural and diagenetic evolution of injected sandstones: examples from the Kimmeridgian of NE Scotland
Abstract: Injected sandstones occurring in the Kimmeridgian of NE Scotland along the bounding Great Glen
and Helmsdale faults formed when basinal fluids moved upward along the fault zones, fluidizing Oxfordian
sands encountered at shallow depth and injecting them into overlying Kimmeridgian strata. The orientation of
dykes, in addition to coeval faults and fractures, was controlled by a stress state related to dextral strike-slip
along the bounding fault zones. Diagenetic studies of cements allow the reconstruction of the fluid flow
history. The origin of deformation bands in sandstone dykes and sills was related to the contraction of the
host-rocks against dyke and sill walls following the initial stage of fluidized flow, and these deformation bands
are the earliest diagenetic imprint. Early non-ferroan calcite precipitated in injection structures at temperatures
between 70 and 100 8C, indicating that it precipitated from relatively hot basinal fluids that drove injection.
Coeval calcite-filled fractures show similar temperatures, suggesting that relatively hot fluids were responsible
for calcite precipitation in any permeable pathway created by dextral simple shear along the faults. During
progressive burial, percolating sea water was responsible for completely cementing the still relatively porous
injected sandstones with a second generation of ferroan calcite, which contains fluid inclusions with
homogenization temperatures below 50 8C. During this phase, depositional host sandstones were also
cemented
Evolutionary genomics and the reach of selection
Unexpected findings in evolutionary genomics both question the role of selection in genome evolution and clarify how genomes work
In vivo and in vitro comparisons of selected grass silages
A three-year study with growing-finishing beef heifers was conducted to determine: (1) if grass or small grain silage can be effectively harvested and fed during the summer to slaughter heifers; (2) if there are differences in feeding value between stages.of maturity and/or the species of grass used; (3) if the results using laboratory techniques for estimating the feeding value of silages are similar to those obtained in the feedlot; (4) whether the digestibility of grass would be different if harvested either earlier or later than the usual recommended harvesting times? Each year 48 or 56 heifers weighing 400-500 pounds and grading medium or good were allotted into eight lots of six or seven each. Two lots were randomly assigned to treatment. The total finishing period was divided into a silage phase and a concentrate phase. When the heifers reached weights of 700-900 pounds and an average condition grade of Good, they were slaughtered. Statistical analysis proved there was no significant difference (P \u3e .05) in average daily gain (ADC) or feed efficiency between the small grain silages (oat and wheat) and permanent grass silages (alfalfa-orchardgrass and ladino-orchardgrass). There was also no significant difference (P \u3e .05) in ADG or feed efficiency between the two ensiled stages of maturity. The digestible dry matter (DDM) difference between samples air dried or freeze dried was nonsignificant (P \u3e .05). Samples fermented in simulated and conventional silos did not have significantly different (P \u3e .05) DDM. Silage harvested before the recommended harvesting time had significantly higher (P \u3c .05) DDM. This early-cut silage also had a higher proximate analysis. The proximate analysis decreased for harvesting at later maturity stages except for the last two stages which increased slightly
Abradable compressor and turbine seals, volume 1
The application and advantages of abradable coatings as gas-path seals in a general aviation turbine engine were evaluated for use on the high-pressure compressor, the high-pressure turbine, and the low-pressure turbine shrouds. Topics covered include: (1) the initial selection of candidate materials for interim full-scale engine testing; (2) interim engine testing of the initially selected materials and additional candidate materials; (3) the design of the component required to adapt the hardware to permit full-scale engine testing of the most promising materials; (4) finalization of the fabrication methods used in the manufacture of engine test hardware; and (5) the manufacture of the hardware necessary to support the final full-scale engine tests
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