The Seven-parameter Diffusion Model: an Implementation in Stan for Bayesian Analyses.

Diffusion models have been widely used to obtain information about cognitive processes from the analysis of responses and response-time data in two-alternative forced-choice tasks. We present an implementation of the seven-parameter diffusion model, incorporating inter-trial variabilities in drift rate, non-decision time, and relative starting point, in the probabilistic programming language Stan. Stan is a free, open-source software that gives the user much flexibility in defining model properties such as the choice of priors and the model structure in a Bayesian framework. We explain the implementation of the new function and how it is used in Stan. We then evaluate its performance in a simulation study that addresses both parameter recovery and simulation-based calibration. The recovery study shows generally good recovery of the model parameters in line with previous findings. The simulation-based calibration study validates the Bayesian algorithm as implemented in Stan.

The Dirichlet Dual Response Model: An Item Response Model for Continuous Bounded Interval Responses.

Standard response formats such as rating or visual analogue scales require respondents to condense distributions of latent states or behaviors into a single value. Whereas this is suitable to measure central tendency, it neglects the variance of distributions. As a remedy, variability may be measured using interval-response formats, more specifically the dual-range slider (RS2). Given the lack of an appropriate item response model for the RS2, we develop the Dirichlet dual response model (DDRM), an extension of the beta response model (BRM; Noel & Dauvier in Appl Psychol Meas, 31:47-73, 2007). We evaluate the DDRM's performance by assessing parameter recovery in a simulation study. Results indicate overall good parameter recovery, although parameters concerning interval width (which reflect variability in behavior or states) perform worse than parameters concerning central tendency. We also test the model empirically by jointly fitting the BRM and the DDRM to single-range slider (RS1) and RS2 responses for two Extraversion scales. While the DDRM has an acceptable fit, it shows some misfit regarding the RS2 interval widths. Nonetheless, the model indicates substantial differences between respondents concerning variability in behavior. High correlations between person parameters of the BRM and DDRM suggest convergent validity between the RS1 and the RS2 interval location. Both the simulation and the empirical study demonstrate that the latent parameter space of the DDRM addresses an important issue of the RS2 response format, namely, the scale-inherent interdependence of interval location and interval width (i.e., intervals at the boundaries are necessarily smaller).

An adaptive rejection sampler for sampling from the Wiener diffusion model.

The Wiener diffusion model with two absorbing boundaries is one of the most frequently applied models for jointly modeling responses and response latencies in psychological research. We consider four methods for sampling from the model with and without variability in drift rate, starting point, and non-decision time: Inverse transform sampling, rejection sampling, and two new methods based on adaptive rejection sampling (ARS). We implement these four methods in an R package, validate the methods, and compare their sampling speed in different settings. All four implemented methods provide samples that follow the intended distributions. The ARS-based methods, however, outperform the other methods in sampling speed as the requested sample size increases. We provide guidelines for when using ARS is more efficient than using traditional methods and vice versa.

Avaliação da efetividade da esterilização por luz ultravioleta em aerossóis contaminados por Sars-Cov-2 / Evaluation of the effectiveness of ultraviolet light sterilization in aerosols contaminated by Sars-Cov-2 / Evaluación de la eficacia de la esterilización por luz ultravioleta en aerosoles contaminados por Sars-Cov-2

O contato direto e a disseminação aérea são os principais mecanismos de transmissão do SARS-CoV-2. Uma abordagem direta para limitar as transmissões virais no ar é inativá-las dentro de um curto período de tempo após sua produção é a luz ultravioleta C (UVC). Neste sentido, o objetivo do presente estudo foi de avaliar a efetividade do uso de luz ultravioleta na esterilização de aerossóis contaminados pelo SARS-CoV-2. Para o estudo foram analisados todos os pacientes que estavam internados na enfermaria COVID com resultados dos swabs positivos. O paciente escolhido para o estudo encontrava-se com resultado positivo e com 8 dias de sintomas. As medições de contaminação da deposição de aerossol na mesa de tomografia foram realizadas em triplicatas, utilizando swabs estéreis com meio de transporte viral. O paciente foi mantido sozinho dentro desta sala por 30 minutos produzindo aerossóis para que pudesse ocorrer contaminação do ar. Após, foram realizadas as medições utilizando a exposição à luz ultravioleta C, coletada nos minutos 0, 5, 10, 15, 30, 60, 120 e 180, após o paciente ter deixado a sala de tomografia. Esta sequência de medições foi realizada por 6 dias, sendo o primeiro dia sem a exposição da luz UVC e 5 dias com a exposição da luz UVC. Após a coleta dos dados, foi realizada a análise dos swabs para os resultados através do método RT-PCR. Os resultados encontrados das coletas desde o tempo 0 até 180 minutos foram negativos para os 6 dias de estudo. Os resultados dos swabs do paciente seguiram positivos do primeiro até o último dia de estudo. Sendo assim, conclui-se a efetividade da utilização da luz ultravioleta como uma forma de descontaminação, juntamente com a ação antimicrobiana do desinfetante, pois a ausência do vírus vivo evidencia a importância de cuidados de higienização para evitar a reincidência da contaminação após a limpeza.

Direct contact and aerial dissemination are the main transmission mechanisms of SARS-CoV-2. A direct approach to limiting airborne viral transmissions is to inactivate them within a short period of time after their production is ultraviolet C (UVC) light. In this sense, the objective of the present study was to evaluate the effectiveness of using ultraviolet light in the sterilization of aerosols contaminated by SARS-CoV-2. For the study, all patients who were admitted to the COVID ward with positive swab results were analyzed. The patient chosen for the study had a positive result and had had 8 days of symptoms. Measurements of contamination from aerosol deposition on the CT table were performed in triplicate, using sterile swabs with viral transport medium. The patient was kept alone inside this room for 30 minutes, producing aerosols so that air contamination could occur. Afterwards, measurements were performed using exposure to ultraviolet C light, collected at 0, 5, 10, 15, 30, 60, 120 and 180 minutes, after the patient had left the tomography room. This sequence of measurements was carried out in 6 days, the first day being without exposure to UVC light and 5 days with exposure to UVC light. After data collection, swab analysis was performed for the results using the RT-PCR method. The results found for collections from time 0 to 180 minutes were negative for the 6 days of study. The patient's swab results were positive from the first to the last day of the study. Thus, the effectiveness of using ultraviolet light as a form of decontamination is concluded, along with the antimicrobial action of the disinfectant, as the absence of the live virus highlights the importance of hygiene care to prevent the recurrence of contamination after cleaning.

El contacto directo y el contagio por vía aérea son los principales mecanismos de transmisión del SRAS-CoV-2. Un enfoque directo para limitar las transmisiones virales en el aire es inactivarlas en un corto período de tiempo después de su producción es la luz ultravioleta C (UVC). En este sentido, el objetivo del presente estudio fue evaluar la eficacia del uso de la luz ultravioleta en la esterilización de aerosoles contaminados con el SARS-CoV-2. Se analizaron todos los pacientes ingresados en la sala COVID con resultados positivos de los hisopos. El paciente elegido para el estudio era positivo y llevaba 8 días con síntomas. Las mediciones de la contaminación por deposición de aerosoles en la mesa de TC se realizaron por triplicado utilizando hisopos estériles con medio de transporte viral. El paciente se mantuvo solo dentro de esta habitación durante 30 minutos produciendo aerosoles para que se produjera la contaminación del aire. A continuación, se realizaron mediciones mediante la exposición a la luz ultravioleta C, recogidas a los 0, 5, 10, 15, 30, 60, 120 y 180 minutos después de que el paciente saliera de la sala de tomografía. Esta secuencia de mediciones se realizó durante 6 días, el primer día sin exposición a la luz UVC y 5 días con exposición a la luz UVC. Tras la recogida de datos, se realizó el análisis de los hisopos para obtener los resultados mediante el método RT-PCR. Los resultados encontrados en las recolecciones desde el tiempo 0 hasta los 180 minutos fueron negativos para los 6 días de estudio. Los resultados de los hisopos de los pacientes siguieron siendo positivos desde el primer hasta el último día del estudio. Así, se concluye la eficacia del uso de la luz ultravioleta como forma de descontaminación, junto con la acción antimicrobiana del desinfectante, ya que la ausencia de virus vivos pone de manifiesto la importancia de los cuidados higiénicos para evitar la reaparición de la contaminación tras la limpieza.

rtmpt: An R package for fitting response-time extended multinomial processing tree models.

Response-time extended multinomial processing tree models (RT-MPT; Klauer and Kellen, Journal of Mathematical Psychology, 82, 111-130 2018) provide estimates of process-completion times for cognitive processes modeled by means of multinomial processing tree (MPT) models (Batchelder and Riefer, Psychonomic Bulletin & Review, 6, 57-86 1999). We present the R package rtmpt with which it is possible to fit RT-MPT models easily. The package is free and open source, it can be used with two established MPT syntaxes, and has a number of useful features, such as suppressing process-completion times for specific process outcomes, holding process probabilities constant, and changing some prior parameters. In the background of the R package, an altered version of the original C++ code is used for the MCMC sampling. We provide a guide to using rtmpt, validate the underlying hierarchical Bayesian algorithm of rtmpt using simulation-based calibration and show that previously reported results can be reproduced using rtmpt.

Atenolol prevents the formation of expansive hematoma after rhytidoplasty.

OBJECTIVE: To evaluate the perioperative use of atenolol in reducing the incidence of hematoma after rhytidoplasty. METHODS: Between January 2007 and February 2013, 80 patients were randomized into two groups: Group A (n = 26) received perioperative atenolol in order to maintain heart rate (PR) around 60 per minute; Group B (n = 54) did not receive atenolol. Both groups underwent the same anesthetic and surgical technique. We monitored blood pressure (BP), HR, hematoma formation and the need for drainage. Patients were followed-up until the 90th postoperative day. The variables were compared between the groups using the ANOVA test. Continuous variables were presented as mean ± standard deviation and the differences were compared with the Student's t test. Values of p d" 0.05 were considered significant. RESULTS: In group A the mean BP (110-70 mm Hg ± 7.07) and HR (64 / min ± 5) were lower (p d" 0.05) than in group B (135-90 mm Hg ± 10.6) and (76 / min ± 7.5), respectively. There were four cases of expansive hematoma in group B, all requiring reoperation for drainage, and none in group A (p d" 0,001). CONCLUSION: The perioperative use of atenolol caused a decrease in blood pressure and heart rate and decreased the incidence of expanding hematoma after rhytidectomy.

Atenolol prevents the formation of expansive hematoma after rhytidoplasty / O atenolol previne a formação de hematoma expansivo após ritidoplastia

Objective: To evaluate the perioperative use of atenolol in reducing the incidence of hematoma after rhytidoplasty. Methods: Between January 2007 and February 2013, 80 patients were randomized into two groups: Group A (n = 26) received perioperative atenolol in order to maintain heart rate (PR) around 60 per minute; Group B (n = 54) did not receive atenolol. Both groups underwent the same anesthetic and surgical technique. We monitored blood pressure (BP), HR, hematoma formation and the need for drainage. Patients were followed-up until the 90th postoperative day. The variables were compared between the groups using the ANOVA test. Continuous variables were presented as mean ± standard deviation and the differences were compared with the Student's t test. Values of p d" 0.05 were considered significant. Results: In group A the mean BP (110-70mmHg ± 7.07) and HR (64 / min ± 5) were lower (p d" 0.05) than in group B (135-90mmHg ± 10.6) and (76 / min ± 7.5), respectively. There were four cases of expansive hematoma in group B, all requiring reoperation for drainage, and none in group A (p d" 0,001). Conclusion: The perioperative use of atenolol caused a decrease in blood pressure and heart rate and decreased the incidence of expanding hematoma after rhytidectomy. .

Objetivo: avaliar o uso perioperatório do atenolol na redução da incidência de hematoma pós-ritidoplastia. Métodos: entre janeiro de 2007 e fevereiro de 2013 foram randomizados 80 pacientes em dois grupos: Grupo A (n=26) recebeu atenolol perioperatório com objetivo de manter frequência de pulso (FP) ± 60 por minuto, Grupo B (n=54) não recebeu atenolol. Ambos os grupos foram submetidos à mesma técnica anestésico-cirúrgica. A pressão arterial (PA) e FP, formação de hematoma e a necessidade de drenagem foram monitorizados. Houve seguimento até o 90º dia de pós-operatório. As variáveis foram analisadas entre os dois grupos utilizando-se o teste de ANOVA. As variáveis contínuas foram apresentadas como média (± Desvio-padrão) e as diferenças foram comparadas utilizando-se o t de Student. Foram considerados significantes os valores p<0,05. Resultados: as médias no grupo A de PA (110-70mmHg ± 7,07) e FP (64 /min ± 5) foram menores (p<0,05) em relação ao grupo B (135-90mmHg ± 10,6) e (76/min ± 7,5), respectivamente. Houve quatro casos de hematoma expansivo no grupo B, todos com necessidade de reoperação para a sua drenagem e nenhum no grupo A (p<0,001). Conclusão: o uso do atenolol perioperatório promoveu a redução de pressão arterial e frequência de pulso e diminuiu a incidência de hematoma expansivo pós-ritidoplastia. .