3,282 research outputs found
Forces and moments generated by alignerâtype appliances for orthodontic tooth movement: A systematic review and metaâanalysis
The aim of this review was to systematically appraise the evidence on aligner mechanics and forces and moments generated across difference types of aligners. In vitro- laboratory studies for model simulated tooth movement with aligners. Database searches within Medline via Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), LILACS via BIREME Virtual Health Library. Unpublished literature was also searched in Open Grey, ClinicalTrials.gov (www.clinicaltrials.gov), the National Research Register (www.controlled-trials.com) and Center for Open Science (Open Science Framework), using the terms "aligner" AND "orthodontic". Risk of bias assessment was based on the Cochrane Risk of Bias tool. Random effects meta-analyses were conducted. A total of 447 studies were identified through electronic search and after careful consideration of pre- defined eligibility criteria, 13 deemed eligible for inclusion, while 2 were included in the quantitative synthesis. When palatal tipping of the upper central incisor through PET-G aligners was considered, aligner thickness of 0.5, 0.625 or 0.75 mm was not associated with a significantly different moment to force (M/F) ratio, given a common gingival edge width of 3-4 mm. Aligner thickness does not appear to possess a significant role in forces and moments generated by clear aligners under specific settings, while the most commonly examined tooth movements are tipping and rotation. The findings of this review may be applicable to certain conditions in laboratory settings.
Keywords: aligner; force; meta-analysis; moment; systematic review; tooth movement
HIPAD - A Hybrid Interior-Point Alternating Direction algorithm for knowledge-based SVM and feature selection
We consider classification tasks in the regime of scarce labeled training
data in high dimensional feature space, where specific expert knowledge is also
available. We propose a new hybrid optimization algorithm that solves the
elastic-net support vector machine (SVM) through an alternating direction
method of multipliers in the first phase, followed by an interior-point method
for the classical SVM in the second phase. Both SVM formulations are adapted to
knowledge incorporation. Our proposed algorithm addresses the challenges of
automatic feature selection, high optimization accuracy, and algorithmic
flexibility for taking advantage of prior knowledge. We demonstrate the
effectiveness and efficiency of our algorithm and compare it with existing
methods on a collection of synthetic and real-world data.Comment: Proceedings of 8th Learning and Intelligent OptimizatioN (LION8)
Conference, 201
Altruism can proliferate through group/kin selection despite high random gene flow
The ways in which natural selection can allow the proliferation of
cooperative behavior have long been seen as a central problem in evolutionary
biology. Most of the literature has focused on interactions between pairs of
individuals and on linear public goods games. This emphasis led to the
conclusion that even modest levels of migration would pose a serious problem to
the spread of altruism in group structured populations. Here we challenge this
conclusion, by analyzing evolution in a framework which allows for complex
group interactions and random migration among groups. We conclude that
contingent forms of strong altruism can spread when rare under realistic group
sizes and levels of migration. Our analysis combines group-centric and
gene-centric perspectives, allows for arbitrary strength of selection, and
leads to extensions of Hamilton's rule for the spread of altruistic alleles,
applicable under broad conditions.Comment: 5 pages, 2 figures. Supplementary material with 50 pages and 26
figure
Mammographic density, breast cancer risk and risk prediction
In this review, we examine the evidence for mammographic density as an independent risk factor for breast cancer, describe the risk prediction models that have incorporated density, and discuss the current and future implications of using mammographic density in clinical practice. Mammographic density is a consistent and strong risk factor for breast cancer in several populations and across age at mammogram. Recently, this risk factor has been added to existing breast cancer risk prediction models, increasing the discriminatory accuracy with its inclusion, albeit slightly. With validation, these models may replace the existing Gail model for clinical risk assessment. However, absolute risk estimates resulting from these improved models are still limited in their ability to characterize an individual's probability of developing cancer. Promising new measures of mammographic density, including volumetric density, which can be standardized using full-field digital mammography, will likely result in a stronger risk factor and improve accuracy of risk prediction models
Institutions and Functions
What is an institution? And what distinguishes one type of institution from another? We answer these questions using a functionalist approach: types of institutions are identified by their function, or the coordination problems they solve; token institutions are specific solutions to these problems, or equilibria of strategic games. The functionalist approach provides some insights into the limits of reform, or the extent to which institutions \u2013 like marriage, property, or democracy \u2013 can be modified without turning them into entities of a different kind
Acceleration of generalized hypergeometric functions through precise remainder asymptotics
We express the asymptotics of the remainders of the partial sums {s_n} of the
generalized hypergeometric function q+1_F_q through an inverse power series z^n
n^l \sum_k c_k/n^k, where the exponent l and the asymptotic coefficients {c_k}
may be recursively computed to any desired order from the hypergeometric
parameters and argument. From this we derive a new series acceleration
technique that can be applied to any such function, even with complex
parameters and at the branch point z=1. For moderate parameters (up to
approximately ten) a C implementation at fixed precision is very effective at
computing these functions; for larger parameters an implementation in higher
than machine precision would be needed. Even for larger parameters, however,
our C implementation is able to correctly determine whether or not it has
converged; and when it converges, its estimate of its error is accurate.Comment: 36 pages, 6 figures, LaTeX2e. Fixed sign error in Eq. (2.28), added
several references, added comparison to other methods, and added discussion
of recursion stabilit
The Salmonella Genomic Island 1 Is Specifically Mobilized In Trans by the IncA/C Multidrug Resistance Plasmid Family
BACKGROUND: The Salmonella genomic island 1 (SGI1) is a Salmonella enterica-derived integrative mobilizable element (IME) containing various complex multiple resistance integrons identified in several S. enterica serovars and in Proteus mirabilis. Previous studies have shown that SGI1 transfers horizontally by in trans mobilization in the presence of the IncA/C conjugative helper plasmid pR55. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the ability of different prevalent multidrug resistance (MDR) plasmids including extended-spectrum β-lactamase (ESBL) gene-carrying plasmids to mobilize the multidrug resistance genomic island SGI1. Through conjugation experiments, none of the 24 conjugative plasmids tested of the IncFI, FII, HI2, I1, L/M, N, P incompatibility groups were able to mobilize SGI1 at a detectable level (transfer frequency <10(-9)). In our collection, ESBL gene-carrying plasmids were mainly from the IncHI2 and I1 groups and thus were unable to mobilize SGI1. However, the horizontal transfer of SGI1 was shown to be specifically mediated by conjugative helper plasmids of the broad-host-range IncA/C incompatibility group. Several conjugative IncA/C MDR plasmids as well as the sequenced IncA/C reference plasmid pRA1 of 143,963 bp were shown to mobilize in trans SGI1 from a S. enterica donor to the Escherichia coli recipient strain. Depending on the IncA/C plasmid used, the conjugative transfer of SGI1 occurred at frequencies ranging from 10(-3) to 10(-6) transconjugants per donor. Of particular concern, some large IncA/C MDR plasmids carrying the extended-spectrum cephalosporinase bla(CMY-2) gene were shown to mobilize in trans SGI1. CONCLUSIONS/SIGNIFICANCE: The ability of the IncA/C MDR plasmid family to mobilize SGI1 could contribute to its spread by horizontal transfer among enteric pathogens. Moreover, the increasing prevalence of IncA/C plasmids in MDR S. enterica isolates worldwide has potential implications for the epidemic success of the antibiotic resistance genomic island SGI1 and its close derivatives
Evolutionary biology: a basic science for psychiatry?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65529/1/j.1600-0447.1992.tb03234.x.pd
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