Testing for Main Random Effects in Two-Way Random and Mixed Effects Models: Modifying the Statistic

A procedure for testing the significance of the main random effect is proposed under a model which does not require the traditional assumptions of symmetry, homoscedasticity, and normality for the error term and random effects. To accommodate this level of model generality, and also unbalanced designs, suitable adjustments to the F-test are made. The extensive simulations performed under the random effects model, and the unrestricted and restricted versions of the mixed effects model, indicate that the classical F procedure is extremely liberal under heteroscedasticity and unbalancedness. The proposed test procedure performs well in all settings and is comparable to the classical F-test when the classical assumptions are met. An analysis of a dataset from the Mussel Watch Project is presented

A 6-Year Experience of Laser Treatments for Burn Scars in a Regional Burn Center-Safety, Efficacy, and Quality Improvement

Laser treatments have long been used as a treatment method for burn scars. Since 2012, more than 1800 laser treatments were performed at Lehigh Valley Health Network Burn Center, far exceeding any previous cohort in studies exploring laser treatments for burn scars. Although previous research has looked at improving scar appearance and physiology with laser treatments, very few have focused on safety. The purpose of the study was to determine whether laser treatments are a safe treatment option for burn scars. Four hundred and fourteen patients who had undergone at least one laser treatment in the outpatient burn center since 2012 were analyzed. Electronic medical records (EPIC) were reviewed. The data were entered in REDCap and later exported to Microsoft Excel and R Studio for statistical analysis. Most of the complications found were related to the moderate sedation during the procedures and were mild, ie, nausea. The most common adverse effect was prolonged recovery time, which can affect practice flow. The overall postoperative complication rate for laser treatments with and without moderate sedation was minimal at 2.2% and 1.4%, respectively. Pain during and after the procedure averaged 3.9 and 1.7, respectively, on a 1 to 10 scale. The Vancouver Scar Scale showed modest improvement in scar appearance over time with an average improvement of 1.4. The high variability of the Vancouver Scar Scale observed in this series underlines its lack of sensitivity. The study results show that laser treatments for burn scars in the outpatient setting generally are safe for patients in need of burn scar intervention. Some practice flow adjustments need to be taken into consideration when offering these procedures in an outpatient setting

Quiet Supersonic Flights 2018 (QSF18) Test: Galveston, Texas Risk Reduction for Future Community Testing with a Low-Boom Flight Demonstration Vehicle

The Quiet Supersonic Flights 2018 (QSF18) Program was designed to develop tools and methods for demonstration of overland supersonic flight with an acceptable sonic boom, and collect a large dataset of responses from a representative sample of the population. Phase 1 provided the basis for a low amplitude sonic boom testing in six different climate regions that will enable international regulatory agencies to draft a noise-based standard for certifying civilian supersonic overland flight. Phase 2 successfully executed a large scale test in Galveston, Texas, developed well documented data sets, calculated dose response relationships, yielded lessons, and identified future risk reduction activities

Waveforms and Sonic Boom Perception and Response (WSPR): Low-Boom Community Response Program Pilot Test Design, Execution, and Analysis

The Waveforms and Sonic boom Perception and Response (WSPR) Program was designed to test and demonstrate the applicability and effectiveness of techniques to gather data relating human subjective response to multiple low-amplitude sonic booms. It was in essence a practice session for future wider scale testing on naive communities, using a purpose built low-boom demonstrator aircraft. The low-boom community response pilot experiment was conducted in California in November 2011. The WSPR team acquired sufficient data to assess and evaluate the effectiveness of the various physical and psychological data gathering techniques and analysis methods

Quiet Supersonic Flights 2018 (QSF18) Test: Galveston, Texas Risk Reduction for Future Community Testing with a Low-Boom Flight Demonstration Vehicle

The Quiet Supersonic Flights 2018 (QSF18) Program was designed to develop tools and methods for demonstration of overland supersonic flight with an acceptable sonic boom, and collect a large dataset of responses from a representative sample of the population. Phase 1 provided the basis for a low amplitude sonic boom testing in six different climate regions that will enable international regulatory agencies to draft a noise-based standard for certifying civilian supersonic overland flight. Phase 2 successfully executed a large scale test in Galveston, Texas, developed well documented data sets, calculated dose response relationships, yielded lessons, and identified future risk reduction activities

Beef in an Optimal Lean Diet study: effects on lipids, lipoproteins, and apolipoproteins123

Background: A Step I diet with lean beef compared with lean white meat both decrease LDL cholesterol. To our knowledge, no studies have evaluated a low–saturated fatty acid (SFA) (<7% calories) diet that contains lean beef

Testing for Main Random Effects in Two-Way Random and Mixed Effects Models: Modifying the Statistic

A procedure for testing the significance of the main random effect is proposed under a model which does not require the traditional assumptions of symmetry, homoscedasticity, and normality for the error term and random effects. To accommodate this level of model generality, and also unbalanced designs, suitable adjustments to the F-test are made. The extensive simulations performed under the random effects model, and the unrestricted and restricted versions of the mixed effects model, indicate that the classical F procedure is extremely liberal under heteroscedasticity and unbalancedness. The proposed test procedure performs well in all settings and is comparable to the classical F-test when the classical assumptions are met. An analysis of a dataset from the Mussel Watch Project is presented

Testing for Main Random Effects in Two-Way Random and Mixed Effects Models: Modifying the F Statistic

A procedure for testing the significance of the main random effect is proposed under a model which does not require the traditional assumptions of symmetry, and homoscedasticity and normality for the error term and random effects. To accommodate this level of model generality, and also unbalanced designs, suitable adjustments to the F test are made. The extensive simulations performed under the random effects model, and the unrestricted and restricted versions of the mixed effects model, indicate that the classical F procedure is extremely liberal under heteroscedasticity and unbalancedness. The proposed test procedure performs well in all settings and is comparable to the classical F test when the classical assumptions are met. An analysis of a dataset from the Mussel Watch Project is presented.</p