A COMPREHENSIVE VALIDATION OF ACTIVITY TRACKERS FOR ESTIMATING PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOR IN FREE-LIVING SETTINGS

The aim of study one of this dissertation was to compare consumer activity trackers (ATs) with the research-grade ActiGraph™ GT3X-BT accelerometer (AG) in estimating energy expenditure (EE) and steps during orbital shaking at different frequencies. To address this aim, we utilized an electronic orbital shaking protocol (twenty-four, 3-minute trials; 2-hour trials). For all comparisons, the AG served as the reference measure. In the 3-min protocol, we showed that on average, the NL-1000 pedometer (NL) produced the lowest error (-9 steps/3-min) at 0.9 Hz (corresponding to moderate intensity). The magnitude of the error for the NL was 14 steps/3-min at a 3.0 Hz frequency (corresponding to very vigorous intensity). For the 2-hr protocol, estimates from all others were equivocal, with some overestimating steps (bias range: 1,331 steps/2-hrs for the Misfit Shine to 1,921 steps/2-hrs for the Misfit Flash [MFF]). For estimated EE bias ranged from26.6 kcals/2-hrs for the MFF to 45.8 kcals/2-hrs for the Misfit Shine. For other ATs, steps were underestimated (bias range: -5,770 steps/2-hrs for the Garmin Vivofit [GV] to -570 steps/2-hrs for the NL). For EE, the bias ranged from -436.8 kcals/2-hrs for the GV to -261.7 kcals/2-hrs for the Fitbit Flex [FBF]). This study provides evidence about the differences in prediction algorithms by device across a broad range of oscillation frequencies that corresponded to different PA intensity levels. For study two, we sought determine the accuracy and precision of activity trackers (ATs) in estimating steps, EE, activity minutes and sedentary time compared to direct observation (DO)-derived measures (criterion measures) in free-living settings. We also validated commonly used research-grade devices (e.g. hip-worn AG (AGhip), wrist-worn AG (AGwrist). Thirty-two healthy men and women (50% female, 37.5% minority; mean ± SD: Age = 32.3 ± 13.3 years; BMI = 24.4 ± 3.3 kg∙m-2) were directly observed while completing three, 2-hour visits on different days while wearing ten ATs, three research-grade devices and a biometric shirt. A validated DO system was used to derive criterion measures for activity and sedentary time (ST) outcomes. ATs were accurate with varying precision in estimating physical activity (PA) behaviors in free-living settings. Additionally, ATs and research-grade accelerometers performed similarly (e.g. more accurate in estimating steps and less accurate in estimating moderate-to-vigorous PA [MVPA] minutes). For all devices, step estimates were accurate and strongly correlated (r range: 0.91 for the Apple iWatch to 0.97 for the AGhip) with criterion measures but EE and MVPA estimates were less accurate and more variable (EE: r = 0.32 [GV] to r = 0.85 [AGhip]; MVPA: r = 0.2 [NL] to r = 0.75 [AGhip]). For ATs, estimates of sedentary time were the least accurate and weakly correlated (r=0.06 Fitbit One [FBO] and FBF) with criterion measures derived from DO. Implications from this study are that consumers and the research community using ATs such as Fitbit (FB) to track steps can be confident in estimating steps but less confident in estimating sedentary time. This study advances our understanding of the performance characteristics of ATs in free-living natural settings using a validated DO method to derive PA and ST measures. This work significantly advances the field of activity monitor validation that should set the standard for future work. The aims of study three were: 1) to examine the ability of ATs to detect change in PA and ST in free-living settings and 2) to examine the ability of research-grade accelerometers to detect change in PA and ST in free-living settings. To address these aims, we used an innovative approach to analyze data from study two. We defined change as a visit-to-visit difference that was greater than the within-subject standard deviation of the criterion measure (estimated by a linear-mixed model). Confusion matrices were used to examine percent agreement between DO visit-to-visit change and device visit-to-visit change. Key findings were focused on the widely used FBO and FBF and research-grade devices. We showed that, there was similar agreement between the hip-worn FBO and FBF with AGhip and AGwrist in estimates of change in steps (89.1% FBO, 88.8% FBF and 88.3% AGwrist, 91.4% AGhip correct classification), EE (73.4% FBO, 70.6% FBF and 77.0% AGhip correct classification) and MVPA minutes (accept FBF) (79.7% FBO, 65.2% FBF and 71.2% AGwrist, 77.0% AGhip correct classification) with criterion measured change. However, change in ST was more difficult to detect for the FB and AGhip (46.8% FBO, 42.3% FBF, 53.1% AGhip and 72.7% AGwrist correct classification). This novel study provides evidence that as an alternative to research-grade accelerometers, researchers may employ FB to measure step accumulation pre- and post-intervention and have a satisfactory level of confidence in FB change detection. This work significantly advances the field of activity monitor validation research and informs intervention practices that should set the standard for future work. This body of work provides the first comprehensive validation of ATs from highly controlled orbital shaker testing to directly-observed free-living settings. This translational research which has broad applications for using ATs for surveillance and intervention research and by the consumer

Show me your friends: a survey experiment on the effect of coalition signals

Recent studies of coalition-directed voting suggest that what political parties say during a campaign can influence voter perceptions of the likelihood of certain coalitions and that this, in turn, may foster strategic voting in multiparty systems. Here, we expand this argument, and show that pre-election coalition signals also have the potential to influence voter perceptions of the parties themselves. By revealing their coalition preferences, parties provide information on where they stand on the political continuum. We test our argument using a survey experiment run during a regional election campaign in Spain in which we manipulated the coalition signals emitted by two parties: one, a traditional, social-democratic party and, the second, a new, liberal party. Results show how coalition signals can significantly influence the party's position and, ultimately, affect voters' stated probability of voting, especially in the case of the recently founded party

Unexpected event during surveys design: promise and pitfalls for causal inference

An increasing number of studies exploit the occurrence of unexpected events during the fieldwork of public opinion surveys to estimate causal effects. In this paper we discuss the use of this identification strategy based on unforeseen and salient events that split the sample of respondents into treatment and control groups: the Unexpected Event during Surveys Design (UESD). In particular we focus on the assumptions under which unexpected events can be exploited to estimate causal effects and we discuss potential threats to identification, paying especial attention to the observable and testable implications of these assumptions. We propose a series of best practices in the form of various estimation strategies and robustness checks that can be used to lend credibility to the causal estimates. Drawing on data from the European Social Survey we illustrate the discussion of this method with an original study of the impact of the Charlie Hebdo terrorist attacks (Paris, 01/07/2015) on French citizens' satisfaction with their national governmen

Gobierno digital y gestión administrativa en la Municipalidad Provincial de Alto Amazonas, 2022

De acuerdo con el análisis de la realidad se ha considerado como objetivo general determinar la relación que existe entre el gobierno digital y la gestión administrativa en la Municipalidad Provincial de Alto Amazonas. Y para ello, se consideró una metodología, estudio básico, enfoque cuantitativo, diseño no experimental de corte transversal, y de alcance correlación, donde la población y la muestra lo conformaron 103 colaboradores entre servidores y funcionarios públicos, asimismo la técnica aplicada fue la encuesta y el instrumento fue el cuestionario. Entre los resultados más relevantes se encuentran, que el gobierno digital ocupo un nivel bajo en un 44% y la gestión administrativa obtuvo un nivel medio en un 54%. Conclusión: Los resultados comprobaron la relación entre el gobierno digital y la gestión administrativa con una correlación positiva baja, donde el valor de significancia fue 0.000 y el coeficiente rho 0.399. Además, las dimensiones acceso a la Información, servicio al Ciudadano, transparencia de la Información y participación Ciudadana guardan relación con la gestión administrativa, ya que el valor de significancia resultó menor a 0.05

Youth Oriented Activity Trackers: Comprehensive Laboratory- and Field-Based Validation

Background: Commercial activity trackers are growing in popularity among adults and some are beginning to be marketed to children. There is, however, a paucity of independent research examining the validity of these devices to detect physical activity of different intensity levels. Objectives: The purpose of this study was to determine the validity of the output from 3 commercial youth-oriented activity trackers in 3 phases: (1) orbital shaker, (2) structured indoor activities, and (3) 4 days of free-living activity. Methods: Four units of each activity tracker (Movband [MB], Sqord [SQ], and Zamzee [ZZ]) were tested in an orbital shaker for 5-minutes at three frequencies (1.3, 1.9, and 2.5 Hz). Participants for Phase 2 (N=14) and Phase 3 (N=16) were 6-12 year old children (50% male). For Phase 2, participants completed 9 structured activities while wearing each tracker, the ActiGraph GT3X+ (AG) research accelerometer, and a portable indirect calorimetry system to assess energy expenditure (EE). For Phase 3, participants wore all 4 devices for 4 consecutive days. Correlation coefficients, linear models, and non-parametric statistics evaluated the criterion and construct validity of the activity tracker output. Results: Output from all devices was significantly associated with oscillation frequency (r=.92-.99). During Phase 2, MB and ZZ only differentiated sedentary from light intensity (PPr=.76, .86, and .59 for the MB, SQ, and ZZ, respectively). Conclusions: Across study phases, the SQ demonstrated stronger validity than the MB and ZZ. The validity of youth-oriented activity trackers may directly impact their effectiveness as behavior modification tools, demonstrating a need for more research on such devices

Assessing the economic impacts of IT service shutdown during the York flood of 2015 in the UK

In this paper we focus on the ‘Christmas’ flood in York (UK), 2015. The case is special in the sense that little infrastructure was lost or damaged, while a single industry (IT services) was completely knocked out for a limited time. Due to these characteristics, the standard modelling techniques are no longer appropriate. An alternative option is provided by the Hypothetical Extraction Method, or HEM. However, there are restrictions in using the HEM, one being that no realistic substitutes exist for inputs from industries that were affected. In this paper we discuss these restrictions and show that the HEM performs well in the York flood case. In the empirical part of this paper we show that a three-day shutdown of the IT services caused a £3.24 m to £4.23 m loss in York, which is equivalent to 10% of the three days' average GVA (Gross Value Added) of York city. The services sector (excluding IT services) sustained the greatest loss at £0.80 m, where the business support industry which was predominantly hit. This study is the first to apply a HEM in this type of flood on a daily basis

A Comparison of Wrist and Hip Accelerometer Output at Different Walking Speeds

Physical activity has been objectively measured using hip-worn accelerometers for decades. However, wrist-worn accelerometers are currently used in large-scale studies. Differences in wrist and hip dynamics during locomotion may affect monitor output, which may impact how prediction models are built. PURPOSE: To compare ActiGraph™ wrist and hip accelerations (g’s) at varying locomotion speeds. METHODS: Participants (N = 7) wore ActiGraph™ GT3X+ accelerometers on the dominant wrist and hip (sampling rate 80Hz). They performed three 5-minute trials at self-paced (SP), slow (SL), and fast (F) over-ground walking speeds. Mean and standard deviation of the vector magnitude (VM) were calculated from two 20-s data windows per condition. Linear mixed-effects models were used to determine if the relationship was different between speed and vector VM at the hip and wrist. RESULTS: Significant differences were found between the slopes (speed vs VM) of the hip m = 0.052 (95% CI: 0.033, 0.103) compared to the wrist m = 0.195 (95% CI: 0.160, 0.230) p\u3c0.001. DISCUSSION: The results show that ActiGraph™ wrist and hip accelerations (g’s) differ at varying locomotion speeds. There is a curvilinear increase in VM at the wrist as locomotion speed increases, whereas there is a linear increase in VM at the hip as locomotion speed increases. The pattern of change of wrist VM is different and more variable between subjects compared to hip VM, which may impact measurement error and model development. Additionally, wrist VM is more responsive to changes in speed than hip VM, suggesting that a wrist worn accelerometer may be more sensitive to locomotion intensity

Uso de las TIC (tecnologías de la información y de la comunicación) en la formación inicial y permanente del profesorado

Abordaremos brevemente cuatro cuestiones: ¿Cómo pueden contribuir las TIC a la formación inicial y permanente del profesorado? ¿Por qué es imprescindible que el profesorado actual esté familiarizado con las TIC? ¿Hay ejemplos que muestren que las TIC mejoran el proceso de enseñanza / aprendizaje? ¿Qué necesita saber el profesor para llevar las TIC al aula y a su quehacer docente, y sentirse suficientemente cómodo con ellas? Comentaremos algunos ejemplos ~e aplicación de las TIC en la enseñanza presencial y no presencial, y en cursos de formación del profesorado. Presentaremos algunas experiencias con el objetivo de animar a los profesores de ciencias (y de cualquier otra disciplina) al uso de las TIC