Spline histogram method for reconstruction of probability density function of clusters of galaxies

We describe the spline histogram algorithm which is useful for visualization of the probability density function setting up a statistical hypothesis for a test. The spline histogram is constructed from discrete data measurements using tensioned cubic spline interpolation of the cumulative distribution function which is then differentiated and smoothed using the Savitzky-Golay filter. The optimal width of the filter is determined by minimization of the Integrated Square Error function. The current distribution of the TCSplin algorithm written in f77 with IDL and Gnuplot visualization scripts is available from http://www.virac.lv/en/soft.htmlComment: 8 pages, 3 figures, to be published in "Galaxies and Chaos: Theory and Observations", eds. N.Voglis, G.Contoupoulos, conference proceedings (CD version), uses Springer Verlag svmult.cls style file

Bond Strength of an Amorphous Calcium Phosphate–Containing Orthodontic Adhesive

Objective: To determine whether an amorphous calcium phosphate (ACP)-containing adhesive has an acceptable level of shear bond strength to be used as an orthodontic adhesive. Materials and Methods: Sixty extracted premolars were randomly divided into three groups for orthodontic bonding. Group 1 used a composite resin adhesive (Transbond XT), group 2 was bonded with an ACP-containing adhesive (Aegis Ortho), and group 3 used a resin-modified glass ionomer (Fuji Ortho LC). All bonded teeth were stored in distilled water at 37°C for 40 ± 2 hours prior to debonding. Shear bond strength and adhesive remnant index (ARI) were recorded for each specimen. Results: The mean shear bond strengths for the three test groups were: group 1 (15.2 ± 3.6 MPa), group 2 (6.6 ± 1.5 MPa), and group 3 (8.3 ± 2.8 MPa). A one-way analysis of variance showed a significant difference in bond strengths between the groups. A post hoc Tukey test showed group 1 to be significantly (P \u3c .001) greater than groups 2 and 3. A Kruskal-Wallis test and a Mann-Whitney U-test showed groups 1 and 3 exhibited lower ARI scores than group 2, but a majority of specimens in each group had greater than 50% of the cement removed along with the bracket during debonding. Conclusions: The ACP-containing adhesive demonstrated a low, but satisfactory bond strength needed to function as an orthodontic adhesive

Effect of Additives on Mineral Trioxide Aggregate Setting Reaction Product Formation

Introduction Mineral trioxide aggregate (MTA) sets via hydration of calcium silicates to yield calcium silicate hydrates and calcium hydroxide (Ca[OH]2). However, a drawback of MTA is its long setting time. Therefore, many additives have been suggested to reduce the setting time. The effect those additives have on setting reaction product formation has been ignored. The objective was to examine the effect additives have on MTA\u27s setting time and setting reaction using differential scanning calorimetry (DSC). Methods MTA powder was prepared with distilled water (control), phosphate buffered saline, 5% calcium chloride (CaCl2), 3% sodium hypochlorite (NaOCl), or lidocaine in a 3:1 mixture and placed in crucibles for DSC evaluation. The setting exothermic reactions were evaluated at 37°C for 8 hours to determine the setting time. Separate samples were stored and evaluated using dynamic DSC scans (37°C→640°C at10°C/min) at 1 day, 1 week, 1 month, and 3 months (n = 9/group/time). Dynamic DSC quantifies the reaction product formed from the amount of heat required to decompose it. Thermographic peaks were integrated to determine enthalpy, which was analyzed with analysis of variance/Tukey test (α = 0.05). Results Isothermal DSC identified 2 main exothermal peaks occurring at 44 ± 12 and 343 ± 57 minutes for the control. Only the CaCl2 additive was an accelerant, which was observed by a greater exothermic peak at 101 ± 11 minutes, indicating a decreased setting time. The dynamic DSC scans produced an endothermic peak around 450°C–550°C attributed to Ca(OH)2 decomposition. The use of a few additives (NaOCl and lidocaine) resulted in significantly less Ca(OH)2 product formation. Conclusions DSC was used to discriminate calcium hydroxide formation in MTA mixed with various additives and showed NaOCl and lidocaine are detrimental to MTA reaction product formation, whereas CaCl2 accelerated the reaction

The Adequacy of PA Didactic Psychiatric Education

With a shortage of mental health specialists, primary care providers, which increasingly include physician assistants (PAs), must be able to adequately recognize, diagnose, and treat common mental health disorders. Unfortunately, providers are not currently able to meet this challenge and frequently underdiagnose and undertreat psychiatric conditions. This paper examined the amount of didactic education in psychodiagnostics PA students receive compared to the amount of didactic psychodiagnostics training psychotherapists students receive in graduate school. Results indicated that while psychotherapists have, on average, more classroom time, the difference in seat time between PAs and psychotherapists is less than double, but the assigned readings are more than triple for psychotherapists. Moreover, PA programs are not taught directly from the industry standard, the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5). This suggests that PAs have adequate time to be taught psychodiagnosis, but that that the reading assignments are not sufficient. Following from the research, the differences between the biomedical and the biopsychosocial model of health and wellness are explored. Finally, suggestions for further and future research are discussed

Time integration errors and energy conservation properties of the Stormer Verlet method applied to MPM

The success of the Material Point Method (MPM) in solving many challenging problems nevertheless raises some open questions regarding the fundamental properties of the methodsuchastheenergyconservationsincebeingaddressedbyBardenhagenandbyLoveand Sulsky. Similarly while low order symplectic time integration techniques are used with MPM, higher order methods have not been used. For this reason the Stormer Verlet method, a popular and widely-used symplectic method is applied to MPM. Both the time integration error and the energy conservation properties of this method applied to MPM are considered. The method is showntohavelocallythirdorderaccuracyofenergyconservationintime. Thisisincontrastto the locally second order accuracy in energy conservation of the methods that are used in many MPM calculations. This third accuracy accuracy is demonstrated both locally and globally on a standard MPM test example

Nonlinear stability of the mpm method

The Material Point Method (MPM) has been very successful in providing solutions to many challenging problems involving large deformations. The nonlinear nature of MPM makes it necessary to use a full nonlinear stability analysis to determine a stable timestep. The stability analysis of Spigler and Vianello is adapted to MPM and used to derive a stable timestep bound for a model problem. This bound is contrasted against a traditional CFL bound