Physical Equivalence Research Articles

The Negative Effects of Long Time Physical Activity Calorie Equivalent Labeling on Purchase Intention for Unhealthy Food.

(1) Background: Obesity has become a global epidemic that arouse much attention from governments, companies and scholar. Physical activity calorie equivalent (PACE) labels are introduced as a more effective nudge invention on less-calorie ordering. However, the effects of PACE labels are controversial in previous literature, thus, the research objective is to explore the effects of different PACE labels and furtherly to explore the underlying psychological mechanism; (2) Methods: Across four scenario-based experiments, involving potato chips, chocolate and cookies, this study manipulated the three calorie-information labeling (standard calorie label, long time PACE and short time PACE labels). Meanwhile, the mediating mechanism of the effects involving anticipatory guilt and the moderation effects between consumers’ future self-continuity and PACE labels are also measured; (3) Results: Results show that compared with the short time PACE and calorie labels, the longtime PACE labels have more negative influence on consumers’ purchase intention for unhealthy food. What’s more, the anticipatory guilt has negative effect of PACE labels as consumers are often prone to feeling guilty in the process of unhealthy food consumption. In addition, individuals with high future self-continuity have higher self-control and take more consideration of future outcomes, they are reluctant to choose unhealthy food than others; (4) Conclusions: Unhealthy food with a long time PACE label has more negative effect on consumers’ purchase intention rather than a short time PACE label. At the same time, companies that produce healthy foods should actively participate in the movement to label calories through the PACE labels.

Arguments from scientific practice in the debate about the physical equivalence of symmetry-related models

In the recent philosophical literature, several counterexamples to the interpretative principle that symmetry-related models are physically equivalent have been suggested (Belot, in: Batterman (ed) The Oxford handbook of philosophy of physics, Oxford University Press, Oxford, 2013, Noûs 52(4):946–981, 2018; Fletcher in Found Phys 50:228–249, 2020). Arguments based on these counterexamples can be understood as arguments from scientific practice of roughly the following form: because in scientific practice such-and-such symmetry-related models are treated as representing distinct physical situations, these models indeed represent distinct physical situations. In this paper, a strategy for analysing arguments of this type is presented and applied to the examples that can be found in the literature. I argue that if we are exclusively interested in models understood as representing entire possible worlds (not their subsystems), arguments from scientific practice should involve some additional assumptions to guarantee they are relevant for models understood in this way. However, none of the examples presented in the literature satisfy all these additional assumptions, which leads to the conclusion that arguments from scientific practice based on these examples do not undermine the interpretative principle that different symmetry-related models represent the same possible world.

Experimental setup for beams with adjustable rotational stiffness: An educational perspective

AbstractIn structural analysis, the rotations of beams' supports are considered either completely fixed or completely free. Therefore, supports are idealized as fixed, pinned (hinged), or roller. In real structures, regarding rotation, the support behavior is neither fully rigid nor completely free and shows a semi‐rigid behavior in most cases. In this study, an educational test setup was created for a beam with semi‐rigid supports to examine the effect of semi‐rigid support on structural behavior. In this experimental setup, support conditions with different rotational stiffness can be obtained from pinned support to fixed support, which can be easily changed between the pinned and the fixed support. The physical equivalent of the rotational stiffness concept is shown in an easy and understandable way with the theoretical equations. A simulation tool based on the derived analytical equation is also developed using Mathematica Software. The simulation tool provides the users with a way to visualize the deformation of the system. The results of beam tests with different support conditions were compared with the results of the simulation, and the effects of semi‐rigid support on the beam behavior were shown. The results revealed that the semi‐rigid supported beam assembly created can also be used to examine the behavior of frame beams under vertical load. These simple novel experimental setup and simulation tools provided are convenient and useful approaches to demonstrate the structural concepts, including the semi‐rigid support and behavior of beams in a frame structure.

The Beauty of Terror

For several decades I had a series of recurring numinous dreams about drowning and tidal waves. Curious about their symbolic significance, and inspired by Jung’s theory of archetypes, I responded imaginally to a spectacular wild site known as “The Gap” on the south coast of Western Australia. I chose this site because—as a physical equivalent of the abyss and an imaginal embodiment of the Void—it elicited similar emotional responses to my numinous dreams. This is an account of my journey as I peered into that physical void and entered an imaginal one.

On physical and social-cost-based CO2 equivalents for transient albedo-induced forcing

Analyzing land-based climate mitigation measures requires the joint examination of the effects of multiple forcing agents. Non-CO2 forcing agents are often converted into “physical” CO2 equivalents, i.e., expressed in terms of how much CO2 would be required to inflict the same climate forcing as one unit of the agent. Similar conversions can also be based on equal social cost. Social-cost-based CO2 equivalents are ideal for economic applications, as they retain the correct social cost ratio between forcing agents. We present two kinds of social-cost-based CO2 equivalents for albedo-induced (or any other transient) forcing. The emission equivalent expresses transient forcing as equivalent CO2 emissions (tCO2yr−1). The stock equivalent expresses it as an equivalent reduction in the terrestrial carbon stock (tCO2). We compare physical and social-cost-based CO2 equivalents, showing that social-cost-based the emission equivalent is a generalization of its physical counterpart, whereas social-cost-based stock equivalent is not. Nevertheless, the two stock equivalents are structurally similar and of roughly the same magnitude. We discuss how the equivalents can be applied in economic analysis, provide numerical multiplier values for converting transient forcing into emission and stock equivalents, and assess the extent to which physical CO2 equivalents distort the social valuation of transient forcing.

АНАЛИЗ ФИЗИЧЕСКОЙ И РАДИОБИОЛОГИЧЕСКОЙ ЭКВИВАЛЕНТНОСТИ РАССЧИТАННЫХ И ИЗМЕРЕННЫХ ДОЗОВЫХ РАСПРЕДЕЛЕНИЙ ДЛЯ СТЕРЕОТАКСИЧЕСКОЙ ТЕРАПИИ ПРЕДСТАТЕЛЬНОЙ ЖЕЛЕЗЫ

Purpose: Carrying out the analysis of the physical and radiobiological equivalence of dose distributions obtained during the planning of hypofractionated stereotactic radiation therapy of the prostate cancer and verification using a three-dimensional cylindrical dosimeter.
 Material and Methods: Based on the anatomical data of twelve patients diagnosed with prostate carcinoma, stage T2N0M0 with low risk, plans were developed for stereotactic radiation therapy with volumetric modulates arc therapy (VMAT). The dose per fraction was 7,25 Gy for 5 fractions (total dose 36,25 Gy) with a normal photon energy of 10 MV. The developed plans were verified using a three-dimensional cylindrical ArcCHECK phantom. During the verification process, the three-dimensional dose distribution in the phantom was measured, based on which the values of the three-dimensional gamma index and the dose–volume histogram within each contoured anatomical structures were calculated with 3DVH software.
 The gamma index value γ (3 %, 2 mm, GN) at a threshold equal to 20 % of the dose maximum of the plan and the percentage of coincidence of points at least 95 % was chosen as a criterion of physical convergence of the calculated and measured dose distribution according to the recommendations of AAPM TG-218. To analyze the radiobiological equivalence of the calculated and measured dose distribution, the local control probability (TCP) and normal tissue complication probability (NTCP) criteria were used based on the calculated and measured dose–volume histograms. Contours of the target (PTV) and the anterior wall of the rectum were used for the analysis. The approach based on the concept of equivalent uniform dose (EUD) by A. Niemierko was used to calculate the values of TCP/NTCP criteria.
 Results: The results of physical convergence of plans for all patients on the contour of the whole body were higher than 95 % for the criteria γ (3 %, 2 mm, GN). The convergence along the PTV contour is in the range (75.5–95.2)%. The TCP and NTCP values obtained from the measured dose-volume histograms were higher than the planned values for all patients. It was found that the accelerator delivered a slightly higher dose to the PTV and the anterior wall of the rectum than originally planned.
 Conclusion: The capabilities of modern dosimetric equipment allow us move to the verification of treatment plans based on the analysis of TCP / NTCP radiobiological equivalence, taking into account the individual characteristics of the patient and the capabilities of radiation therapy equipment.

Topological vectors as a fingerprinting system for 2D-material flake distributions

The production of 2D material flakes in large quantities is a rapidly evolving field and a cornerstone for their industrial applicability. Although flake production has advanced in a fast pace, its statistical characterization is somewhat slower, with few examples in the literature which may lack either modelling uniformity and/or physical equivalence to actual flake dimensions. The present work brings a methodology for 2D material flake characterization with a threefold target: (i) propose a set of morphological shape parameters that correctly map to actual and relevant flake dimensions; (ii) find a single distribution function that efficiently describes all these parameter distributions; and (iii) suggest a representation system—topological vectors—that uniquely characterizes the statistical flake morphology within a given distribution. The applicability of such methodology is illustrated via the analysis of tens of thousands flakes of graphene/graphite and talc, which were submitted to different production protocols. The richness of information unveiled by this universal methodology may help the development of necessary standardization procedures for the imminent 2D-materials industry.

The effect of calorie and physical activity equivalent labelling of alcoholic drinks on drinking intentions in participants of higher and lower socioeconomic position: An experimental study.

The primary objective of the study was to examine the effect of calorie labelling and physical activity equivalence labelling of alcoholic drinks on drinking intentions in participants of lower and higher socioeconomic position (SEP). Participants (N = 1,084) of higher and lower SEP were recruited into an online study and randomized into one of three drink label conditions; Control (standard alcohol labelling), kcal labelling (standard labelling plus drink kilocalorie information), or kcal + PACE labelling (standard labelling and kilocalorie information, plus information on physical activity needed to compensate for drink calories). After viewing drink labels, participants reported alcohol drinking intentions. Participants also completed measures of alcoholic drink energy content estimation, beliefs about how calorie labelling would affect health behaviour and support for calorie labelling of alcoholic drinks. kcal labelling (d = 0.31) and kcal + PACE labelling (d = 0.38) conditions had significantly lower drinking intentions compared to the control condition (ps < .001). There was no evidence that effect of labelling condition on drinking intentions was moderated by SEP. A subset of participants also reported that they believed calorie labelling would be likely to positively change their eating and exercise behaviour. Estimates of the energy content of alcoholic drinks tended to be inaccurate and the majority of participants supported the introduction of calorie labelling on alcoholic drinks. Calorie labelling of alcoholic drinks resulted in small reductions to intended drinking and testing of the effect calorie labelling has on behaviour in real-world settings is now warranted.

A Novel Grid Forming Control Scheme Revealing a True Inertia Principle

This article proposes an unconventional strategy for a grid forming converter, based on a phase restoring control concept by which a constant steady state frequency is achieved. This control scheme is inherently without a phase-locked loop (PLL) and keeps the power system frequency at its nominal value. Under disturbance, the control response mimics infinite virtual inertia since the power system frequency always returns to its nominal value. Therefore, this control presents a physical equivalence to a power system response with substantial inertia provided by synchronous machines. The understanding of frequency drift as a local phenomenon and power system frequency as a global aspect is briefly introduced. Further, the inherent discretization of a converter control as part of the feedback loop over the continuous network system is also considered. The concept has been mathematically investigated in a realistic test bench and global stability of the control is displayed based on the necessary boundary conditions. Simulation results supporting the mathematical hypothesis and visualizing the controller actions are presented. As a beneficial coincidence of these ideas, the control structure ensures similar responses in both electromagnetic transients (EMT) and root mean square (RMS) simulations.

Identification of genetic loci affecting body mass index through interaction with multiple environmental factors using structured linear mixed model

Multiple environmental factors could interact with a single genetic factor to affect disease phenotypes. We used Struct-LMM to identify genetic variants that interacted with environmental factors related to body mass index (BMI) using data from the Korea Association Resource. The following factors were investigated: alcohol consumption, education, physical activity metabolic equivalent of task (PAMET), income, total calorie intake, protein intake, carbohydrate intake, and smoking status. Initial analysis identified 7 potential single nucleotide polymorphisms (SNPs) that interacted with the environmental factors (P value < 5.00 × 10−6). Of the 8 environmental factors, PAMET score was excluded for further analysis since it had an average Bayes Factor (BF) value < 1 (BF = 0.88). Interaction analysis using 7 environmental factors identified 11 SNPs (P value < 5.00 × 10−6). Of these, rs2391331 had the most significant interaction (P value = 7.27 × 10−9) and was located within the intron of EFNB2 (Chr 13). In addition, the gene-based genome-wide association study verified EFNB2 gene significantly interacting with 7 environmental factors (P value = 5.03 × 10−10). BF analysis indicated that most environmental factors, except carbohydrate intake, contributed to the interaction of rs2391331 on BMI. Although the replication of the results in other cohorts is warranted, these findings proved the usefulness of Struct-LMM to identify the gene–environment interaction affecting disease.

The Differential Effects of Physical Activity Calorie Equivalent Labeling on Consumer Preferences for Healthy and Unhealthy Food Products: Evidence from a Choice Experiment.

Background: Since numerical calorie labels have limited effects on less-calorie food ordering, an alternative called physical activity calorie equivalent (PACE) labels, which exhibit calories using visible symbols and the minutes of exercise to burn off the calories, may be more effective in reducing calories ordered. Methods: By using a choice experiment (CE) approach, the aims of this study were to estimate the effects of PACE labels on consumer preferences for healthy and unhealth food. Red date walnuts and potato chips were used as the representatives of healthy and unhealthy foods respectively in this study. Moreover, future time perspective (FTP) is an individual trait variable of consumers, which has been recognized as a significant driver of healthy behaviors. We also included FTP into the interaction with PACE labels. Results: Firstly, the results were opposite between the healthy and unhealthy food groups. Respondents showed significantly more positive attitudes toward red date walnuts (i.e., healthy food) with PACE labels, while they showed significantly more negative preferences for chips (i.e., unhealthy food) with PACE labels. Secondly, people with higher FTP are preferred red date walnuts with PACE labels, while PACE labels on chips could undermine the preferences of respondents with higher FTP. Thirdly, we found that women (vs. men) were less inclined to choose healthy food with standard calorie labels and labels showing the minutes of running to burn off the calories, as well as that the elderly (vs. younger) people in the healthy food group preferred the labels showing the minutes of running to burn off the calories. People with a higher body mass index (BMI) were reluctant to purchase walnuts with the information about the minutes of walking. Conclusions: Results from this study showed that PACE labels have significant effects on consumers’ preferences for food products.

Quantum corrections to generic branes: DBI, NLSM, and more

We study quantum corrections to hypersurfaces of dimension d + 1 > 2 embedded in generic higher-dimensional spacetimes. Manifest covariance is maintained throughout the analysis and our methods are valid for arbitrary co-dimension and arbitrary bulk metric. A variety of theories which are prominent in the modern amplitude literature arise as special limits: the scalar sector of Dirac-Born-Infeld theories and their multi-field variants, as well as generic non-linear sigma models and extensions thereof. Our explicit one-loop results unite the leading corrections of all such models under a single umbrella. In contrast to naive computations which generate effective actions that appear to violate the non-linear symmetries of their classical counterparts, our efficient methods maintain manifest covariance at all stages and make the symmetry properties of the quantum action clear. We provide an explicit comparison between our compact construction and other approaches and demonstrate the ultimate physical equivalence between the superficially different results.

Thermally induced vibration suppression in a thermoelastic beam structure

In this paper, the problem of thermally induced vibration suppression in a thermoelastic beam is studied. Physical equivalent of the present problem is that a thermoelastic beam is suddenly entering into daylight zone and vibrations are induced due to heating on the upper surface of the beam or thermoelastic beam in a spacecraft enters to intensive sunlight area just after leaving a shadow of a planet. Thermally induced vibrations are suppressed by means of minimum using of control forces to be applied to dynamic space actuators. Objective functional of the problem is chosen as a modified quadratical functional of the kinetic energy of the thermoelastic beam. Necessary optimality condition to be satisfied by an optimal control force is derived in the form of maximum principle, which converts the optimal vibration suppression problem to solving a system of distributed parameters system linked by initial-boundary-terminal conditions. Solution of the system is achieved via MATLAB? and simulated results reveal that thermally induced vibration suppression by means of dynamic space actuators are very effective and robust.

ОЦІНКА ПАРАМЕТРІВ ШОРСТКОСТІ ЗЕМНОЇ ПОВЕРХНІ ЗА ДВОХПОЛЯРИЗАЦІЙНИМ РАДІОЛОКАЦІЙНИМ ВІДБИТТЯМ МЕТОДОМ ЗВОРОТНОГО МОДЕЛЮВАННЯ

Радіолокаційне дистанційне зондування є сучасним та ефективним методом аерокосмічних досліджень Землі. Масове впровадження нових радіолокаційних систем високої розрізненності на основі радіолокаторів з синтезованою апертурою (РСА) значно розширило можливості радарного знімання. Доцільність застосування даного методу було підтверджено в сферах, що традиційно використовують дані дистанційного зондування – картографії, сільському і лісовому господарстві, пошуку корисних копалини, охорони навколишнього середовища, моніторингу надзвичайних ситуацій, обороні. Основним фізичним параметром земної поверхні, який реєструється неінтерферометричними РСА, є коефіцієнт зворотного розсіяння (сигма-нуль). Прийнятий радарний сигнал є джерелом для складного моделювання процесів зворотного розсіяння та оцінки вторинних фізичних і біофізичних характеристик земної поверхні -- текстури, зволоженості, діелектричної проникності, структури рослинного покриву тощо. При цьому шорсткість земної поверхні, яка описується середньоквадратичним відхиленням її вертикальних нерегулярностей, виступає одним з найбільш значущих чинників будь-якого моделювання. Отже, задача відновлення шорсткості земної поверхні за даними радіолокаційного дистанційного зондування є досить актуальною. Шорсткість земної поверхні – це незалежна фізична величина, що багато в чому визначає радіолокаційне зворотне розсіяння. Проте радіус кореляції шорсткості залежить від поляризації радіолокаційного сигналу. У статті описується кількісний підхід до відновлення шорсткості земної поверхні за двохполяризаційними зображеннями РСА на основі узгодження вимірів незалежної фізичної величини – діелектричної проникності в різних поляризаціях. Використовується запропонована Багдаді та ін. напівемпіричне калібрування IEM радіолокаційного зворотного розсіяння з урахуванням поляризаційно-залежної величини радіуса кореляції для забезпечення фізичної еквівалентності вимірів діелектричної проникності земної поверхні в різних поляризаціях. Крім того, приведені необхідні розрахункові співвідношення та приклад обробки реального радіолокаційного зображення Sentinel-1. Одержані результати в цілому відповідають відомим фізичним закономірностям і ландшафтним особливостям території дослідження.

Gravitational contact interactions and the physical equivalence of Weyl transformations in effective field theory

Theories of scalars and gravity, with non-minimal interactions, $\sim (M_P^2 +F(\phi) )R +L(\phi)$, have graviton exchange induced contact terms. These terms arise in single particle reducible diagrams with vertices $\propto q^2$ that cancel the Feynman propagator denominator $1/q^2$ and are familiar in various other physical contexts. In gravity these lead to additional terms in the action such as $\sim F(\phi) T_\mu^\mu(\phi)/M_P^2$ and $F(\phi)\partial^2 F(\phi)/M_P^2$. The contact terms are equivalent to induced operators obtained by a Weyl transformation that removes the non-minimal interactions, leaving a minimal Einstein-Hilbert gravitational action. This demonstrates explicitly the equivalence of different representations of the action under Weyl transformations, both classically and quantum mechanically. To avoid such "hidden contact terms" one is compelled to go to the minimal Einstein-Hilbert representation.

Solar System tests in Brans\u2013Dicke and Palatini f({mathcal {R}})-theories

We compare Mercury’s precession test in standard general relativity, Brans–Dicke theories (BD), and Palatini f({mathcal {R}})-theories. We avoid post-Newtonian approximation and compute exact precession in these theories. We show that the well-known mathematical equivalence between Palatini f({mathcal {R}})-theories and a specific subset of BD theories does not extend to a really physical equivalence among theories since equivalent models still allow a different incompatible precession for Mercury depending on the solution one chooses. As a result one cannot use BD equivalence to rule out Palatini f({mathcal {R}})-theories. On the contrary, we directly discuss that Palatini f({mathcal {R}})-theories can (and specific models do) easily pass Solar System tests as Mercury’s precession.

A randomized controlled trial testing the effects of a positive front-of-pack label with or without a physical activity equivalent label on food purchases

BackgroundPositive front-of-pack (FOP) labels, including Singapore’s Healthier Choice Symbol (HCS), target a subset of healthier products whose consumption is to be encouraged. However, this may inadvertently lead to excess caloric intake, which could be addressed by including an additional label identifying calories per serving. We test this hypothesis by adding a Physical Activity Equivalent (PAE) label, an indicator of calorie content, to all products available in an on-line grocery store. MethodsWe conducted a randomized controlled trial using a 3 arm within-subject crossover design in adult Singapore residents recruited online. Participants shopped once in each condition in an experimental online grocery store in random order: 1) no FOP label (Control); 2) Select products displaying HCS labels (HCS-only); 3) Condition 2 with additional information displaying PAEs per serving on every product (HCS+PAE). 117 participants were recruited and data from 317 shops were analyzed. We used first-differenced regressions to assess the impact of the conditions on calories per serving (primary) and on other measures of diet quality. ResultsThe HCS-only condition led to a statistically significant five-percentage point increase in the proportion of HCS products purchased (95% CI, 1%: 9%). However, neither the HCS-only (3.45; 95% CI, −12.52: 19.43) nor HCS + PAE (8.14; 95% CI, −5.25: 21.54) condition led to a change in the number of calories per serving purchased or changes in other measures of diet quality. ConclusionsPositive labels, like the HCS, are likely to increase purchases of labelled products. However, these changes may not lead to improvements in diet quality or calorie intake. Combining positive labels with additional PAE information does not appear to address this concern.

A Mobile Technology for Collecting Patient-Reported Physical Activity and Distress Outcomes: Cross-Sectional Cohort Study.

BackgroundElectronic patient-reported outcome (PROs) provides a fast and reliable assessment of a patient’s health-related quality of life. Nevertheless, using PRO in the traditional paper format is not practical for clinical practice due to the limitations associated with data analysis and management. A questionnaire app was developed to address the need for a practical way to group and use distress and physical activity assessment tools.ObjectiveThe purpose of this study was to assess the level of agreement between electronic (mobile) and paper-and-pencil questionnaire responses.MethodsWe validated the app version of the distress thermometer (DT), International Physical Activity Questionnaire (IPAQ), and Patient Health Questionnaire–9 (PHQ-9). A total of 102 participants answered the paper and app versions of the DT and IPAQ, and 96 people completed the PHQ-9. The study outcomes were the correlation of the data between the paper-and-pencil and app versions.ResultsA total of 106 consecutive breast cancer patients were enrolled and analyzed for validation of paper and electronic (app) versions. The Spearman correlation values of paper and app surveys for patients who responded to the DT questionnaire within 7 days, within 3 days, and on the same day were .415 (P<.001), .437 (P<.001), and .603 (P<.001), respectively. Similarly, the paper and app survey correlation values of the IPAQ total physical activity metabolic equivalent of task (MET; Q2-6) were .291 (P=.003), .324 (P=.005), and .427 (P=.01), respectively. The correlation of the sum of the Patient Health Questionnaire–9 (Q1-9) according to the time interval between the paper-based questionnaire and the app-based questionnaire was .469 for 14 days (P<.001), .574 for 7 days (P<.001), .593 for 3 days (P<.001), and .512 for the same day (P=.03). These were all statistically significant. Similarly, the correlation of the PHQ (Q10) value according to the time interval between the paper-based questionnaire and the app-based questionnaire was .283 for 14 days (P=.005), .409 for 7 days (P=.001), .415 for 3 days (P=.009), and .736 for the same day (P=.001). These were all statistically significant. In the overall trend, the shorter the interval between the paper-and-pencil questionnaire and the app-based questionnaire, the higher the correlation value.ConclusionsThe app version of the distress and physical activity questionnaires has shown validity and a high level of association with the paper-based DT, IPAQ (Q2-6), and PHQ-9. The app-based questionnaires were not inferior to their respective paper versions and confirm the feasibility for their use in clinical practice. The high correlation between paper and mobile app data allows the use of new mobile apps to benefit the overall health care system.Trial RegistrationClinicalTrials.gov NCT03072966; https://clinicaltrials.gov/ct2/show/NCT03072966

An issue with the classification of the scalar–tensor theories of gravity

In the bibliography, a certain confusion arises in what regards to the classification of the gravitational theories into scalar–tensor theories (STT) and general relativity with a scalar field either minimally or nonminimally coupled to matter. Higher-derivatives Horndeski and beyond Horndeski theories that at first sight do not look like STT only add to the confusion. To further complicate things, the discussion on the physical equivalence of the different conformal frames in which a given scalar–tensor theory may be formulated, makes even harder to achieve a correct classification. In this paper, we propose a specific criterion for an unambiguous identification of STT and discuss its impact on the conformal transformations issue. The present discussion carries not only pedagogical but also scientific interest since an incorrect classification of a given theory as a scalar–tensor theory of gravity may lead to conceptual issues and to the consequent misunderstanding of its physical implications.

Physical Inactivity among Ghanaians in Ghana and Ghanaian Migrants in Europe.

There is a paucity of data on physical activity (PA) among migrants from sub-Saharan Africa, yet physical inactivity is a key risk factor for noncommunicable diseases. We examined the levels of physical inactivity and its determinants among Ghanaians in different geographical locations. We used the Research on Obesity and Diabetes among African Migrants data of Ghanaian adults (n = 4760) age 25-70 yr in rural and urban Ghana and three European cities (Amsterdam, London, and Berlin). Using total physical activity metabolic equivalent of task, physical inactivity was defined as total physical activity metabolic equivalent of task minutes per week less than 600. Logistic regression was used to examine the differences in the levels and the determinants of physical inactivity across sites. Physical inactivity was higher among Ghanaian migrants (14.6% in Amsterdam, 24.1% in Berlin, and 36.6% in London) and urban Ghanaians (29.0%) compared with rural Ghanaians (11.2%). After adjustment for covariates (age, sex, education, health status, smoking status, body mass index, and social network) using rural Ghanaians as the comparator group, the odds ratios for physical inactivity in men ranged from 3.67 (95% confidence interval, 2.19-6.16) in urban Ghanaians to 10.37 (5.96-18.02) in London Ghanaians, and from 3.27 (2.46-4.35) in urban Ghanaians to 4.41 (3.12-6.22) in London Ghanaians in women. Migrants in London and Berlin had higher odds of physical inactivity compared with Amsterdam. Increased age, university education, and overweight/obesity were positively associated with physical inactivity, whereas social support was inversely associated with physical inactivity with variability across sites. Findings indicate high prevalence of physical inactivity among Ghanaians in all sites, particularly among Ghanaians in Europe. Hence, there is the need to take local context into account to improve PA.