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1.
Med Phys ; 51(3): 2277-2292, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37991110

RESUMEN

BACKGROUND: A Faraday cup (FC) facilitates a quite clean measurement of the proton fluence emerging from clinical spot-scanning nozzles with narrow pencil-beams. The utilization of FCs appears to be an attractive option for high dose rate delivery modes and the source models of Monte-Carlo (MC) dose engines. However, previous studies revealed discrepancies of 3%-6% between reference dosimetry with ionization chambers (ICs) and FC-based dosimetry. This has prevented the widespread use of FCs for dosimetry in proton therapy. PURPOSE: The current study aims at bridging the gap between FC dosimetry and IC dosimetry of proton fields delivered with spot-scanning treatment heads. Particularly, a novel method to evaluate FC measurements is introduced. METHODS: A consistency check is formulated, which makes use of the energy balance and the reciprocity theorem. The measurement data comprise central-axis depth distributions of the absorbed dose of quasi-monochromatic fields with a width of about 28.5 cm and FC measurements of the reciprocal fields with a single spot. These data are complemented by a look-up of energy-range tables, the average Q-value of transmutations, and the escape energy carried away by neutrons and photons. The latter data are computed by MC simulations, which in turn are validated with measurements of the distal dose tail and neutron out-of-field doses. For comparison, the conventional approach of FC evaluation is performed, which computes absorbed dose from the product of fluence and stopping power. The results from the FC measurements are compared with the standard dosimetry protocols and improved reference dosimetry methods. RESULTS: The deviation between the conventional FC-based dosimetry and the IC-based one according to standard dosimetry protocols was -4.7 ( ± $\pm$ 3.3)% for a 100 MeV field and -3.6 ( ± $\pm$ 3.5)% for 200 MeV, thereby agreeing within the reported uncertainties. The deviations could be reduced to -4.0 ( ± $\pm$ 2.9)% and -3.0 ( ± $\pm$ 3.1)% by adopting state-of-the-art reference dosimetry methods. The alternative approach using the energy balance gave deviations of only -1.9% (100 MeV) and -2.6% (200 MeV) using state-of-the-art dosimetry. The standard uncertainty of this novel approach was estimated to be about 2%. CONCLUSIONS: An alternative concept has been established to determine the absorbed dose of monoenergetic proton fields with an FC. It eliminates the strong dependence of the conventional FC-based approach on the MC simulation of the stopping-power and of the secondary ions, which according to the study at hand is the major contributor to the underestimation of the absorbed dose. Some contributions to the uncertainty of the novel approach could potentially be reduced in future studies. This would allow for accurate consistency tests of conventional dosimetry procedures.


Asunto(s)
Terapia de Protones , Protones , Radiometría/métodos , Simulación por Computador , Calibración , Método de Montecarlo , Dosificación Radioterapéutica
2.
Sci Data ; 10(1): 622, 2023 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-37704660

RESUMEN

The potential impacts that video games might have on players' well-being are under increased scrutiny but poorly understood empirically. Although extensively studied, a level of understanding required to address concerns and advise policy is lacking, at least partly because much of this science has relied on artificial settings and limited self-report data. We describe a large and detailed dataset that addresses these issues by pairing video game play behaviors and events with in-game well-being and motivation reports. 11,080 players (from 39 countries) of the first person PC game PowerWash Simulator volunteered for a research version of the game that logged their play across 10 in-game behaviors and events (e.g. task completion) and 21 variables (e.g. current position), and responses to 6 psychological survey instruments via in-game pop-ups. The data consists of 15,772,514 gameplay events, 726,316 survey item responses, and 21,202,667 additional gameplay status records, and spans 222 days. The data and codebook are publicly available with a permissive CC0 license.

3.
R Soc Open Sci ; 9(7): 220411, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35911206

RESUMEN

Video games are a massively popular form of entertainment, socializing, cooperation and competition. Games' ubiquity fuels fears that they cause poor mental health, and major health bodies and national governments have made far-reaching policy decisions to address games' potential risks, despite lacking adequate supporting data. The concern-evidence mismatch underscores that we know too little about games' impacts on well-being. We addressed this disconnect by linking six weeks of 38 935 players' objective game-behaviour data, provided by seven global game publishers, with three waves of their self-reported well-being that we collected. We found little to no evidence for a causal connection between game play and well-being. However, results suggested that motivations play a role in players' well-being. For good or ill, the average effects of time spent playing video games on players' well-being are probably very small, and further industry data are required to determine potential risks and supportive factors to health.

4.
Sci Rep ; 12(1): 61, 2022 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-34992220

RESUMEN

It is often assumed that traditional forms of media such as books enhance well-being, whereas new media do not. However, we lack evidence for such claims and media research is mainly focused on how much time people spend with a medium, but not whether someone used a medium or not. We explored the effect of media use during one week on well-being at the end of the week, differentiating time spent with a medium and use versus nonuse, over a wide range of different media types: music, TV, films, video games, (e-)books, (digital) magazines, and audiobooks. Results from a six-week longitudinal study representative of the UK population 16 years and older (N = 2159) showed that effects were generally small; between-person relations but rarely within-person effects; mostly for use versus nonuse and not time spent with a medium; and on affective well-being, not life satisfaction.

5.
R Soc Open Sci ; 8(2): 202049, 2021 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-33972879

RESUMEN

People have never played more video games, and many stakeholders are worried that this activity might be bad for players. So far, research has not had adequate data to test whether these worries are justified and if policymakers should act to regulate video game play time. We attempt to provide much-needed evidence with adequate data. Whereas previous research had to rely on self-reported play behaviour, we collaborated with two games companies, Electronic Arts and Nintendo of America, to obtain players' actual play behaviour. We surveyed players of Plants vs. Zombies: Battle for Neighborville and Animal Crossing: New Horizons for their well-being, motivations and need satisfaction during play, and merged their responses with telemetry data (i.e. logged game play). Contrary to many fears that excessive play time will lead to addiction and poor mental health, we found a small positive relation between game play and affective well-being. Need satisfaction and motivations during play did not interact with play time but were instead independently related to well-being. Our results advance the field in two important ways. First, we show that collaborations with industry partners can be done to high academic standards in an ethical and transparent fashion. Second, we deliver much-needed evidence to policymakers on the link between play and mental health.

6.
J Exp Psychol Gen ; 150(3): 431-445, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32881564

RESUMEN

Human behavior can be classified into 2 basic categories: execution of responses and withholding responses. This classification is used in go/no-go training, where people respond to some objects and withhold their responses to other objects. Despite its simplicity, there is now substantial evidence that such training is powerful in changing human behavior toward such objects. However, it is poorly understood how simple responses can influence behavior. Contrary to the remarkably tenacious idea that go/no-go training changes behavior by strengthening inhibitory control, we propose that the training changes behavior via changes in explicit liking of objects. In two preregistered experiments, we show that go/no-go training influences explicit liking for smartphone apps (Experiments 1 and 2) and that this liking partially mediates the effect of the training on consequential choices for using these apps 1 day later (Experiment 2). The results highlight the role of evaluations when examining how motor response training influences behavior. This knowledge can inform development of more effective applied motor response training procedures and raises new theoretical questions on the relation between motor responses and affect. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Asunto(s)
Emociones/fisiología , Inhibición Psicológica , Aplicaciones Móviles , Teléfono Inteligente , Adolescente , Adulto , Femenino , Humanos , Masculino , Adulto Joven
7.
Appetite ; 155: 104812, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-32827576

RESUMEN

The production of meat is a main contributor to current dangerous levels of greenhouse gas emissions. However, the shift to more plant-based diets is hampered by consumers finding meat-based foods more attractive than plant-based foods. How can plant-based foods best be described to increase their appeal to consumers? Based on the grounded cognition theory of desire, we suggest that descriptions that trigger simulations, or re-experiences, of eating and enjoying a food will increase the attractiveness of a food, compared to descriptions emphasizing ingredients. In Study 1, we first examined the descriptions of ready meals available in four large UK supermarkets (N = 240). We found that the labels of meat-based foods contained more references to eating simulations than vegetarian foods, and slightly more than plant-based foods, and that this varied between supermarkets. In Studies 2 and 3 (N = 170, N = 166, pre-registered), we manipulated the labels of plant-based and meat-based foods to either include eating simulation words or not. We assessed the degree to which participants reported that the description made them think about eating the food (i.e., induced eating simulations), and how attractive they found the food. In Study 2, where either sensory or eating context words were added, we found no differences with control labels. In Study 3, however, where simulation-based labels included sensory, context, and hedonic words, we found that simulation-based descriptions increased eating simulations and attractiveness. Moreover, frequent meat eaters found plant-based foods less attractive, but this was attenuated when plant-based foods were described with simulation-inducing words. We suggest that language that describes rewarding eating experiences can be used to facilitate the shift toward healthy and sustainable diets.


Asunto(s)
Dieta , Carne , Preferencias Alimentarias , Humanos , Comidas , Recompensa
8.
Dialogues Clin Neurosci ; 22(2): 135-142, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32699513

RESUMEN

This review provides an overview of the literature regarding digital technology use and adolescent well-being. Overall, findings imply that the general effects are on the negative end of the spectrum but very small. Effects differ depending on the type of use: whereas procrastination and passive use are related to more negative effects, social and active use are related to more positive effects. Digital technology use has stronger effects on short-term markers of hedonic well-being (eg, negative affect) than long-term measures of eudaimonic well-being (eg, life satisfaction). Although adolescents are more vulnerable, effects are comparable for both adolescents and adults. It appears that both low and excessive use are related to decreased well-being, whereas moderate use is related to increased well-being. The current research still has many limitations: High-quality studies with large-scale samples, objective measures of digital technology use, and experience sampling of well-being are missing.
.


Esta revisión entrega una panorámica de la literatura acerca del empleo de la tecnología digital y el bienestar de los adolescentes. En general, los resultados traducen que los efectos globales son negativos, aunque muy insignificantes. Los efectos difieren según el tipo de empleo: la procastinación y el empleo pasivo están relacionados con efectos más negativos; en cambio, el empleo social y activo se asocia con efectos más positivos. El empleo de la tecnología digital tiene efectos más potentes en los indicadores de corto plazo del bienestar hedónico (como los afectos negativos) que las mediciones a largo plazo del bienestar eudaimónico (como la satisfacción con la vida). Aunque los adolescentes son más vulnerables, los efectos son comparables para adolescentes y adultos. Parece que tanto el empleo reducido como el excesivo están relacionados con una disminución del bienestar, mientras que el empleo moderado se vincula con un mayor bienestar. La investigación actual todavía tiene muchas limitaciones: faltan estudios de alta calidad con muestras numerosas, mediciones objetivas del empleo de tecnología digital y muestras de experiencia de bienestar.


Nous proposons ici une revue de la littérature sur la pratique des technologies numériques et le bien-être de l'adolescent. Les données générales sont en faveur d'un effet négatif mais qui reste négligeable. L'usage définit la nature de l'effet : la procrastination et la passivité sont associées à un effet plus négatif alors qu'une pratique active et tournée vers la socialisation s'associe à un effet plus positif. Les effets sont plus importants sur les marqueurs à court terme du bien-être hédonique (comme les affects négatifs) que sur ceux à long terme du bien-être eudémonique (épanouissement personnel) ; ils sont comparables chez les adultes et les adolescents, même si ces derniers sont plus fragiles. Une utilisation excessive ou à l'inverse insuffisante semble diminuer le bien-être, alors qu'une pratique modérée l'augmenterait. Cependant, la recherche actuelle manque encore d'études de qualité élevée à grande échelle, de mesures objectives de la pratique des technologies numériques et d'expérience d'échantillonnage du bien-être.


Asunto(s)
Conducta del Adolescente/psicología , Salud del Adolescente/tendencias , Tecnología Digital/tendencias , Internet/tendencias , Adolescente , Conducta del Adolescente/fisiología , Humanos
9.
Cyberpsychol Behav Soc Netw ; 21(12): 761-767, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30499683

RESUMEN

As mobile technology allows users to be online anywhere and at all times, a growing number of users report feeling constantly alert and preoccupied with online streams of online information and communication-a phenomenon that has recently been termed online vigilance. Despite its growing prevalence, consequences of this constant orientation toward online streams of information and communication for users' well-being are largely unclear. In the present study, we investigated whether being constantly vigilant is related to cognitive consequences in the form of increased mind-wandering and decreased mindfulness and examined the resulting implications for well-being. To test our assumptions, we estimated a path model based on survey data (N = 371). The model supported the majority of our preregistered hypotheses: online vigilance was indeed related to mind-wandering and mindfulness, but only mindfulness mediated the relationship with decreased well-being. Thus, those mentally preoccupied with online communication were overall less satisfied with their lives and reported less affective well-being when they also experienced reduced mindfulness.


Asunto(s)
Atención , Atención Plena , Medios de Comunicación Sociales , Adulto , Concienciación , Comunicación , Femenino , Humanos , Encuestas y Cuestionarios , Adulto Joven
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