Effect of workload history on vigilance performance.

Effects of sudden transitions in workload level on performance indices were investigated within the newly emerging paradigm of workload history. It has been previously reported that a sudden decrease in workload level results in a significant immediate decrement in performance (Cumming & Croft, 1973; Goldberg & Stewart, 1980; Matthews, 1986). Study 1 consisted of 198 participants who completed a protocol of training, baseline and test trials designed to examine the effects of workload history on performance. Specifically, this study tested for the reported general decrement in performance and investigated the nature of the decrement. Results indicated that a sudden decrease in workload level results in an immediate significant decrement in response time, total errors, etc., while a sudden increase fails to result in the same immediate decrement. This study reports new findings, i.e., either a sudden increase or decrease could lead to a loss in accuracy and a slowing of response time in a longer time course. An explanation of the decrement is offered in terms of a resource adaptation-depletion model. Study 2 tested whether time on task or fatigue might have been responsible for the decrement in performance following sudden transitions in workload (reported in Study 1). No significant results were found; therefore, it appears that the decrement in performance following workload transitions is a result of something inherent in the workload shift rather than an effect of time on task or fatigue

Effect of Workload History on Task Performance

Objective: This study investigated the effects of workload history (specifically, sudden shifts in workload) on performance. Background: In 1993 the National Research Council identified workload transition as an important concern for human factors researchers. The study of workload history suggests that what an individual has been doing prior to a point in time has an effect on subsequent performance. One trend emerging from workload history studies is that a general decrement in performance is most likely to occur following a decrease in task demand. Method: The 198 participants were randomly assigned to a high-to-low or low-to-high condition. Participants performed a version of the Bakan Vigilance Task while correct responses, response times, and total errors were recorded. Results: Results supported previous research suggesting a workload decrease results in a performance decrement. More importantly, this study reports that either a sudden increase or decrease could lead to a loss in accuracy and a slowing of response time in a longer time course. Conclusion: An explanation of the decrement is offered in terms of adaptation models. In addition, a follow-up study suggested that the decrement is a result of something inherent in the workload shift rather than an effect of fatigue. Application: Workload history (more specifically, a workload shift) has significant implications for many work environments. These implications are particularly salient in occupations where individuals are confronted with varying levels of workload demand, especially safety-sensitive occupations.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Contentious histories and the perception of threat:China, the United States, and the Korean War- an experimental analysis

Chinese and Korean protests over "revisionist" Japanese histories of World War II are well known. The impact of contested Chinese and US histories of the Korean War on US-China relations today has received less attention. More broadly, there has been little research seeking to systematically explore just how history textbook controversies matter for international relations. This article experimentally manipulates the impact of nation (US/China), of source (in-group/out-group textbooks), and of valence (positive/negative historical narratives) on measures of beliefs about the past, emotions, collective self-esteem, and threat perception in present-day US-China relations. A 2 x 2 x 2 design exposed randomized groups of Chinese and US university students to fictional high school history textbook accounts of the Korean War. Findings reveal significant effects of nation, source, and valence and suggest that the "historical relevance" of a shared past to national identities in the present has a dramatic impact on how historical controversies affect threat perception.Social Sciences, InterdisciplinarySSCI2ARTICLE3433-465

Effects of Steroidal and Non Steroidal Drugs on the Neovascularization Response Induced by Tumoral TA3 Supernatant on CAM from Chick Embryo

Angiogenesis, the development of new blood vessels from the existing vascular network, may result as a consequence of the increase or decrease of proangiogenic or antiangiogenic factors, respectively. The tumor itself could up-regulate the production of angiogenic factors. Recently, we established that the steroidal drug betamethasone in low concentration inhibit the neovascularization promoted by TA3 Ts on CAM of chick embryos. We describe here the effects of the non-steroidal drug ketoprofen, alone or in association with betamethasone, on the angiogenesis promoted by TA3 Ts on CAM. The main finding reported here is that the formation of new blood vessels is strongly inhibited by low concentrations of ketoprofen. The association of both drugs produced a synergistic effect, significantly decreasing tumoral supernatant angiogenesis. It is known that steroidal anti-inflammatory drugs inhibit the enzymes required for the production of prostaglandins through a nuclear GR mediated mechanism. This may operate as a general mechanism in endothelial cells as well. Considering that the induction of COX 1 and COX2 are inhibited by ketoprofen, and that these enzymes are located in the stromal compartment of the CAM, we propose that its antiangiogenic effect may occur via inhibition of the two COX isoforms. In fact, we found that ketoprofen induced apoptosis in both the stromal fibroblast and endotelial cells. The potentiated effect of the combination of betamethasone and ketoprofen may have some therapeutic projections in the control of pathological angiogenesi

Efecto inmediato de la terapia de tracto vocal semiocluido en los parámetros acústicos en los procesos de masculinización y feminización de la voz

El propósito de este estudio es determinar, describir y comparar el efecto inmediato de la Terapia de tracto vocal semiocluido (TVSO) sobre los parámetros acústicos en los procesos de feminización y masculinización de la voz de 40 transexuales de entre 18 y 40 años. Corresponde a un estudio de tipo cuantitativo, con un diseño preexperimental con pre y post prueba, con una dimensión de temporalidad trasversal y un alcance descriptivo y comparativo. El instrumento utilizado para medir los parámetros acústicos fue el programa de análisis acústico de la voz PRAAT (Boersma y Weenink, 2018). Los resultados indican que, aunque en las transexuales femeninas los valores de los parámetros acústicos disminuyeron, sólo existió efecto inmediato en los parámetros acústicos Jitter local, Jitter APQ5, Relación armónico-ruido y Frecuencia fundamental (F0), por tanto, lo que indica que las voces se agudizaron. En transexuales masculinos, se modificó la F0 luego de la terapia, entonces la voz se hizo más grave. Se concluye que la terapia de TVSO tiene efecto inmediato principalmente en el Jitter y en el F0 y puede considerarse una alternativa, viable y complementaria en el proceso de masculinización y feminización de la vo

Immediate effect of semioccluded vocal tract therapy on acoustic parameters in the processes of masculinization and feminization of the voice

El propósito de este estudio es determinar, describir y comparar el efecto inmediato de la Terapia de tracto vocal semiocluido (TVSO) sobre los parámetros acústicos en los procesos de feminización y masculinización de la voz de 40 transexuales de entre 18 y 40 años. Corresponde a un estudio de tipo cuantitativo, con un diseño preexperimental con pre y post prueba, con una dimensión de temporalidad trasversal y un alcance descriptivo y comparativo. El instrumento utilizado para medir los parámetros acústicos fue el programa de análisis acústico de la voz PRAAT (Boersma y Weenink, 2018). Los resultados indican que, aunque en las transexuales femeninas los valores de los parámetros acústicos disminuyeron, sólo existió efecto inmediato en los parámetros acústicos Jitter local, Jitter APQ5, Relación armónico-ruido y Frecuencia fundamental (F0), por tanto, lo que indica que las voces se agudizaron. En transexuales masculinos, se modificó la F0 luego de la terapia, entonces la voz se hizo más grave. Se concluye que la terapia de TVSO tiene efecto inmediato principalmente en el Jitter y en el F0 y puede considerarse una alternativa, viable y complementaria en el proceso de masculinización y feminización de la voz.The purpose of this study is to determine, describe and compare the immediate effect of Semioccluded Vocal Tract Therapy (TVSO) on acoustic parameters in the processes of feminization and masculinization of the voice of 40 transsexuals between 18 and 40 years old. It corresponds to a quantitative study, with a preexperimental design with pre and post test, with a dimension of transversal temporality and a descriptive and comparative scope. The instrument used to measure acoustic parameters was the acoustic voice analysis program PRAAT (Boersma and Weenink, 2018).The results indicate that although in the female transsexuals the values of the acoustic parameters decreased; there was only immediate effect in Local Jitter, Jitter APQ5, Harmonic-noise ratio and Fundamental frequency (F0); that shows that the female’s voice became high-pitched. In male transsexuals, F0 was modified after therapy, then the voice became more deep. It is concluded that TVSO therapy has an immediate effect mainly on Jitter and F0 and can be considered an alternative, viable and complementary therapy in the process of masculinization and feminization of voic

Violencia: razones y sinrazones

Es altamente probable que este siglo que está recién comenzando supere al siglo XX descrito por Hobsbawm como el más sanguinario del que la Historia tenga registro; juicio éste compartido por personajes tan dispares como René Dumont, William Golding e Isaiah Berlin. Vivimos en tiempos violentos. Hemos hasta llegado a perder la capacidad de asombro frente a las diversas manifestaciones de violencia que nos hacen conocer los programas cotidianos de noticias... Hemos querido profundizar en el conocimiento de la diversas formas de violencia no sólo las manifiestas, sino también las ocultas, las estructurales, aquéllas que se nos han hecho incluso tan habituales que ni siquiera somos capaces de reconocerlas. Aquellas a las cuales Barcellona se refiere cuando dice: “Esta violencia cotidiana y difusa no es la violencia del ángel exterminador ni la del vengador justiciero; es una violencia sin rostro y sin objetivo, anónima e indeterminada: se parece a la contaminación atmosférica y a la desertización de los campos, y nada en absoluto a la revuelta social y a la rebelión de protesta”