Dental Dam Utilization by Dentists in an Intramural Faculty Practice

Objectives: From casual observation of our colleagues, only a few individuals use the dental dam for operative procedures in their faculty practice. The purpose of this study was to obtain faculty perceptions of the dental dam, quantify its utilization in their intramural faculty practice, and determine the factors that influence dental dam usage.Materials and Methods: A survey containing 11 questions was sent to 19 faculty members who teach full time and maintain an intramural dental practice involving operative dentistry. Thirty electronic dental health records of the 19 providers were reviewed to gather the following information from restorative procedures they completed: isolation methods, tooth location and involved surfaces, and dental restorative material.Results: Overall, dental dam was utilized for 30% of all restorative procedures and was used less than 20% of the time for placement of class II and class III composite resins. Dental dam utilization rate by general dentists was 37% and 17.6% for prosthodontists. Those general dentists with prior history of military dental practice had a utilization rate of 78.6% and nonmilitary dentists only 7.6%. Eight faculty members responded to the questionnaire for a 42% return rate. Those who practiced dentistry in the military strongly agreed that the dental dam is the standard of care, improves their quality of restorative work, and should be documented in the dental record.Conclusions: There were significantly different dental dam utilization rates between general dentists and prosthodontists and between dentists with prior military experience and those without

Substantial regional variation in substitution rates in the human genome: importance of GC content, gene density and telomere-specific effects

This study presents the first global, 1 Mbp level analysis of patterns of nucleotide substitutions along the human lineage. The study is based on the analysis of a large amount of repetitive elements deposited into the human genome since the mammalian radiation, yielding a number of results that would have been difficult to obtain using the more conventional comparative method of analysis. This analysis revealed substantial and consistent variability of rates of substitution, with the variability ranging up to 2-fold among different regions. The rates of substitutions of C or G nucleotides with A or T nucleotides vary much more sharply than the reverse rates suggesting that much of that variation is due to differences in mutation rates rather than in the probabilities of fixation of C/G vs. A/T nucleotides across the genome. For all types of substitution we observe substantially more hotspots than coldspots, with hotspots showing substantial clustering over tens of Mbp's. Our analysis revealed that GC-content of surrounding sequences is the best predictor of the rates of substitution. The pattern of substitution appears very different near telomeres compared to the rest of the genome and cannot be explained by the genome-wide correlations of the substitution rates with GC content or exon density. The telomere pattern of substitution is consistent with natural selection or biased gene conversion acting to increase the GC-content of the sequences that are within 10-15 Mbp away from the telomere.Comment: 35 pages, 6 figure

MIMO Channel Correlation in General Scattering Environments

This paper presents an analytical model for the fading channel correlation in general scattering environments. In contrast to the existing correlation models, our new approach treats the scattering environment as non-separable and it is modeled using a bi-angular power distribution. The bi-angular power distribution is parameterized by the mean departure and arrival angles, angular spreads of the univariate angular power distributions at the transmitter and receiver apertures, and a third parameter, the covariance between transmit and receive angles which captures the statistical interdependency between angular power distributions at the transmitter and receiver apertures. When this third parameter is zero, this new model reduces to the well known "Kronecker" model. Using the proposed model, we show that Kronecker model is a good approximation to the actual channel when the scattering channel consists of a single scattering cluster. In the presence of multiple remote scattering clusters we show that Kronecker model over estimates the performance by artificially increasing the number of multipaths in the channel.Comment: Australian Communication Theory Workshop Proceedings 2006, Perth Western Australia. (accepted

Multiple domestications of asian rice

In their recent Correspondence about our study showingthat there were three origins of Asian rice2, Huang and Han suggest that the methodology that we used to infer multiple domestications was flawed as it did not take account of the strong genetic bottleneck in japonica

Resilience–Recovery Factors in Post-traumatic Stress Disorder Among Female and Male Vietnam Veterans: Hardiness, Postwar Social Support, and Additional Stressful Life Events

Structural equation modeling procedures were used to examine relationships among several war zone stressor dimensions, resilience-recovery factors, and post-traumatic stress disorder symptoms in a national sample of 1,632 Vietnam veterans (26% women and 74% men). A 9-factor measurement model was specified on a mixed-gender subsample of the data and then replicated on separate subsamples of female and male veterans. For both genders, the structural models supported strong mediation effects for the intrapersonal resource characteristic of hardiness, postwar structural and functional social support, and additional negative life events in the postwar period. Support for moderator effects or buffering in terms of interactions between war zone stressor level and resiliencerecovery factors was minimal

Thromboprophylaxis in atrial fibrillation and association with cognitive decline: systematic review

Objective:Atrial Fibrillation (AF) is associated with dementia. If AF-related cognitive decline is driven by cerebral embolic events, thromboprophylaxis may impact on this. This systematic review assessed the association between cognitive impairment and AF thromboprophylaxis. Methods:Two independent reviewers searched CINAHL, EMBASE, MEDLINE, PsycINFO, Web of Science Core Collection, and Cochrane Library from inception until 12th November 2014. Eligible studies compared AF thromboprophylaxis to control with an outcome measure of cognition or dementia. Where data allowed, meta-analyses describing between-group differences in cognitive test scores or rates of incident dementia were performed. Results:Nineteen studies were eligible. For two prospective studies (one RCT) comparing anticoagulation against antiplatelet therapy, change in Mini-Mental State Examination score from baseline to last follow-up (maximal duration:5.9 years) suggested a difference favouring anticoagulation (mean difference:0.90, 95% CI:0.29 to 1.51), in keeping with a trend seen in the single RCT (mean difference MMSE:0.80. 95% CI:-0.07 to 1.67). Pooled odds ratios suggested no association with incident dementia, comparing anticoagulant to antiplatelet therapy (two studies, OR:1.23, 95% CI:0.80 to 1.91) or no treatment (three studies, OR:0.89, 95%CI:0.47 to 1.69). Conclusions:Our analyses show no definitive evidence of cognitive benefit or harm from anticoagulation. We demonstrated a potential benefit of anticoagulation in comparison to antiplatelet over time. Larger-scale studies with longer follow-up are needed to determine the true cognitive impact of AF thromboprophylaxis

Application of triggered lightning numerical models to the F106B and extension to other aircraft

The goal of the F106B Thunderstorm Research Program is to characterize the lightning environment for aircraft in flight. This report describes the application of numerical electromagnetic models to this problem. Topics include: (1) Extensive application of linear triggered lightning to F106B data; (2) Electrostatic analysis of F106B field mill data; (3) Application of subgrid modeling to F106B nose region, including both static and nonlinear models; (4) Extension of F106B results to other aircraft of varying sizes and shapes; and (5) Application of nonlinear model to interaction of F106B with lightning leader-return stroke event