Treatment with Antiobesity Drugs in Weight Regain After Bariatric Surgery: a Retrospective Cohort Study.

BACKGROUND: Bariatric surgery is the most efficient treatment for obesity. However, in some cases, weight regain can occur. Currently, it is unknown the best antiobesity medication (AOM) for such clinical situation. This study aims to evaluate the effect of AOM in patients with weight regain after bariatric surgery. METHODS: A retrospective cohort study from December 2010 to July 2019 with patients submitted to bariatric surgery that had weight regain and received AOM for at least 2 years. RESULTS: Of 96 patients that had weight regain in the analyzed period and received AOM, 16 were excluded from the analysis due to non-compliance (n = 7), treatment failure (n = 5), intolerable side effects with all available AOM (n = 2), or interaction with other medications (n = 2). Eighty patients were included in the analysis. The mean age was 59.0 ± 10.1 years, 88.8% were female, 91.2% white, and most of them were submitted to gastric bypass (87.6%). The mean preoperative and nadir weight after surgery were 127.9 ± 25.5 kg and 84.7 ± 22.8 kg, respectively. At the initiation of AOM, the mean baseline weight was 99.4 ± 23.1 kg. After 2 years of follow-up, there was significant weight loss in the groups treated with topiramate-alone (- 3.2 kg), topiramate plus sibutramine (- 6.1kg), and orlistat-alone or in combination (- 3.9kg). No statistical difference was observed in the sibutramine-alone group. CONCLUSION: Topiramate (alone or associated with sibutramine) and orlistat (alone or in combination) promoted significant weight loss after 2 years of use in patients submitted to bariatric surgery with weight regain.

Inconsistencies between mental fatigue measures under compensatory control theories / Inconsistencias entre medidas de fatiga mental bajo las teorías del control compensatorio

Mental fatigue has traditionally been defined as a condition of reduced cognitive efficiency and performance, accompanied by a subjective feeling of fatigue. Even though we could expect to find associations between the three defining characteristic of mental fatigue (performance impairment, physiological deactivation and subjective fatigue), research has shown that the emergence of inconsistencies between measures is more frequent than one might expect: people proved capable of maintaining adequate performance levels even after having declared themselves fatigued. This could be explained under the compensatory control mechanism models, which state that humans are able to provide additional resources under demanding conditions, but only at the expense of psychophysiological cost and subjective fatigue. We tested this explanation by manipulating task complexity and time performing a simulated air-traffic control task. We collected psychophysiological, performance and subjective data. A decrease in pupil size was seen in the low-aircraft-density condition, while pupil size remained constant in the high-aircraft-density condition. Participants' task performance was optimal in both conditions, though they showed an increase in subjective feelings of fatigue, especially in the high-complexity task condition. Thus, complexity seemed to trigger compensatory mechanisms, which reallocated extra resources that physiologically activated participants in order to deal with a higher complexity task, whereas subjective fatigue could be acting as a signal to the organism of impending resource depletion. Our findings support compensatory control theories and offer an explanation of inconsistencies between fatigue measures. Further research on compensatory mechanisms is needed to enable better management of fatigue effects to prevent work-related accidents

Tradicionalmente, la fatiga mental ha sido definida como una condición de reducción en los niveles de eficiencia cognitiva y rendimiento, acompañada de una sensación subjetiva de fatiga mental. A pesar de que podríamos esperar encontrar asociaciones (convergencia) entre las tres características definitorias de la fatiga mental (deterioro en el rendimiento, reducción en los niveles de activación fisiológica y surgimiento de fatiga subjetiva), la literatura ha revelado que la aparición de inconsistencias (divergencia) entre las medidas de fatiga es más frecuente de lo esperado: la gente se muestra capaz de mantener niveles adecuados de rendimiento a pesar de haber declarado encontrarse fatigados. Esto puede explicarse a partir de los modelos del mecanismo de control compensatorio, los cuales afirman que los seres humanos son capaces de proveerse con recursos adicionales bajo condiciones de elevada demanda cognitiva, únicamente a expensas de un coste psicofisiológico y del surgimiento de la sensación subjetiva de fatiga mental. En el presente estudio, ponemos a prueba esta explicación manipulando el tiempo y la complejidad de una tarea de simulación de control de tráfico aéreo. Recabamos datos psicofisiológicos, de rendimiento y subjetivos. Nuestros resultados desvelan una disminución del diámetro pupilar en la condición de baja densidad de tráfico aéreo, en tanto que se mantiene constante en la condición de alta densidad. El nivel de rendimiento de los participantes resultó ser óptimo en ambas condiciones, a pesar de que se aprecia un incremento lineal en los niveles de fatiga subjetiva, especialmente en la condición de alta complejidad. Así, la complejidad parece activar el mecanismo compensatorio, el cual provee al organismo con recursos adicionales que mantienen fisiológicamente activados a los participantes de la condición de alta densidad de tráfico al objeto de hacer frente a una tarea de mayor dificultad, mientras que la fatiga subjetiva podría estar actuando como una señal del organismo para impedir el agotamiento de los recursos cognitivos. Nuestros hallazgos apoyan las teorías del control compensatorio y ofrecen una posible explicación sobre algunas inconsistencias entre las medidas de fatiga mental. La ciencia necesita seguir investigando el fenómeno del mecanismo compensatorio para favorecer la gestión de los efectos de la fatiga mental y prevenir los accidentes laborales

Determinants of sleepiness at work among railway control workers.

In the last two decades the control of the Portuguese railway network has become much more centralized in three centres, there integrating the functions of route flow management, electrical control and signalling. This study aimed to investigate the influence of work and individual determinants in sleepiness among railway control workers, namely socio-demographic factors, work ability, psychosocial factors, shiftwork characteristics, fatigue perception, and sleep. Sleepiness by shift was associated with quality of sleep, job satisfaction, fatigue perception, quantitative demands, and age. The results indicate a high prevalence of sleepiness during the night shift and show the relevance of the quality of sleep as a predictor in the three models of sleepiness for morning, afternoon and night shifts. This study, done at the major Portuguese railway control centre, alerted managers to the importance of schedule planning as well as sleepiness prevention plans and makes these results a reference for future research.

Effects of competing environmental variables and signage on route-choices in simulated everyday and emergency wayfinding situations.

This study examined the relative influence of environmental variables (corridor width and brightness) and signage (directional and exit signs), when presented in competition, on participants' route-choices in two situational variables (everyday vs. emergency), during indoor wayfinding in virtual environments. A virtual reality-based methodology was used. Thus, participants attempted to find a room (everyday situation) in a virtual hotel, followed by a fire-related emergency egress (emergency situation). Different behaviours were observed. In the everyday situation, for no-signs condition, participants choose mostly the wider and brighter corridors, suggesting a heavy reliance on the environmental affordances. Conversely, for signs condition, participants mostly complied with signage, suggesting a greater reliance on the signs rather than on the environmental cues. During emergency, without signage, reliance on environmental affordances seems to be affected by the intersection type. In the sign condition, the reliance on environmental affordances that started strong decreases along the egress route.

The influence of environmental features on route selection in an emergency situation.

Understanding the influence of external information at a lower level of awareness during the processes of route selection could be a key factor to predict user's movements within complex buildings, avoiding wayfinding problems and improving egress in emergency situations. This study aims to verify whether corridor intersection configuration attributes, such as width and brightness, act as factors of attraction to improve the affordance of indoor hallways during an emergency egress situation, using a VR-based methodology. The main hypotheses are that users tend to move along either, wider or brighter corridors. Thirty volunteers participated in this study, moving along 57 different corridors, according to the experimental conditions of the study. The results suggest that people prefer to follow brighter pathways in "T-type" and "F-type" intersections, and wider corridors in "T-type" intersections. In situations where these variables are in conflict, there is a preference for brighter paths in both intersection configurations.

Using environmental affordances to direct people natural movement indoors.

Understanding and predicting people's displacement movement is particularly important for professionals involved in planning complex buildings (e.g., hospitals, convention centers, subway stations and university campus). Some decisions taken by the visitors while choosing what route to follow can be influenced by some environmental cues which can act as a factor of attraction, influencing the wayfinding process. Therefore, the main objective of this study was to evaluate the hypotheses that, in the context of a simulated emergency egress, people prefer to move along either a wider and with more lighting corridor or to bear right. To collect the users' responses, a constant stimulus method was used, combined with a two forced choices method, involving the projection of stereoscopic images in a wall-screen. Results suggest that, in a "T-type" intersection, users randomly chose which direction to follow. However, if there is an increment in the width of the side corridor, users tend to follow the wider corridor. When light is inserted, users also prefer to choose the corridors with more lighting. In situations where the variables corridor width and existence of lighting are concurrent, the corridors with light are the most chosen by the users.

What should I do?--a study about conflicting and ambiguous warning messages.

Warnings are intended to reduce accidents caused by hazards. Behavioral compliance is the most important measure of warning effectiveness. However, in result of diverse circumstances (e.g., distraction, misuse, negligence), conflicting or ambiguous safety messages can be perceived. Since these are recurrent and can result in wrong behaviors encompassing severe consequences, such cases should be studied for safety purposes. We report findings on the participants' compliant behavior when performing a work-related task, while immersed in a virtual environment, and investigate the effect of conflicting messages on compliance with warnings. Two warnings (one regular and one with an appended out-of-order sign) and two types of signs (static and dynamic) were considered. The warning with the out-of-order sign configures the case of potentially conflicting messages. The gender effect was also investigated. The participants' behavior was assessed regarding to pushing a button as directed by the warnings. In the "out-of-order" warning, compliance was higher in the dynamic situation (53.3%) than in the static one (3.3%). Comparing with the non-conflicting warning, compliance was higher for both situations (static: 76.7%; dynamic: 100%). Women complied more than men. Although these results have limitations in their generalization, they are nonetheless relevant and deserve to be studied further.

Using virtual reality to assess user experience.

OBJECTIVE: The aim of this article is to discuss how user experience (UX) evaluation can benefit from the use of virtual reality (VR). BACKGROUND: UX is usually evaluated in laboratory settings. However, considering that UX occurs as a consequence of the interaction between the product, the user, and the context of use, the assessment of UX can benefit from a more ecological test setting. VR provides the means to develop realistic-looking virtual environments with the advantage of allowing greater control of the experimental conditions while granting good ecological validity. METHOD: The methods used to evaluate UX, as well as their main limitations, are identified.The currentVR equipment and its potential applications (as well as its limitations and drawbacks) to overcome some of the limitations in the assessment of UX are highlighted. RESULTS: The relevance of VR for UX studies is discussed, and a VR-based framework for evaluating UX is presented. CONCLUSION: UX research may benefit from a VR-based methodology in the scopes of user research (e.g., assessment of users' expectations derived from their lifestyles) and human-product interaction (e.g., assessment of users' emotions since the first moment of contact with the product and then during the interaction). APPLICATION: This article provides knowledge to researchers and professionals engaged in the design of technological interfaces about the usefulness of VR in the evaluation of UX.