scholarly journals A scoping review of chronotype and temporal patterns of eating of adults: Tools used, findings, and future directions

2021 ◽  
pp. 1-51
Author(s):  
Yan Yin Phoi ◽  
Michelle Rogers ◽  
Maxine P. Bonham ◽  
Jillian Dorrian ◽  
Alison M. Coates

Abstract Circadian rhythms, metabolic processes, and dietary intake are inextricably linked. Timing of food intake is a modifiable temporal cue for the circadian system and may be influenced by numerous factors, including individual chronotype—an indicator of an individual’s circadian rhythm in relation to the light-dark cycle. This scoping review examines temporal patterns of eating across chronotypes and assesses tools that have been used to collect data on temporal patterns of eating and chronotype. A systematic search identified thirty-six studies in which aspects of temporal patterns of eating including meal timings; meal skipping; energy distribution across the day; meal frequency; time interval between meals, or meals and wake/sleep times; midpoint of food/energy intake; meal regularity; and duration of eating window were presented in relation to chronotype. Findings indicate that compared to morning chronotypes, evening chronotypes tend to skip meals more frequently, have later mealtimes, and distribute greater energy intake towards later times of the day. More studies should explore the difference in meal regularity and duration of eating window amongst chronotypes. Currently, tools used in collecting data on chronotype and temporal patterns of eating are varied, limiting the direct comparison of findings between studies. Development of a standardised assessment tool will allow future studies to confidently compare findings to inform the development and assessment of guidelines that provide recommendations on temporal patterns of eating for optimal health.

2021 ◽  
Vol 13 (4) ◽  
pp. 490-499
Author(s):  
Paul Kukulski ◽  
James Ahn

ABSTRACT Background The standardized letter of evaluation (SLOE) is the application component that program directors value most when evaluating candidates to interview and rank for emergency medicine (EM) residency. Given its successful implementation, other specialties, including otolaryngology, dermatology, and orthopedics, have adopted similar SLOEs of their own, and more specialties are considering creating one. Unfortunately, for such a significant assessment tool, no study to date has comprehensively examined the validity evidence for the EM SLOE. Objective We summarized the published evidence for validity for the EM SLOE using Messick's framework for validity evidence. Methods A scoping review of the validity evidence of the EM SLOE was performed in 2020. A scoping review was chosen to identify gaps and future directions, and because the heterogeneity of the literature makes a systematic review difficult. Included articles were assigned to an aspect of Messick's framework and determined to provide evidence for or against validity. Results There have been 22 articles published relating to validity evidence for the EM SLOE. There is evidence for content validity; however, there is a lack of evidence for internal structure, relation to other variables, and consequences. Additionally, the literature regarding response process demonstrates evidence against validity. Conclusions Overall, there is little published evidence in support of validity for the EM SLOE. Stakeholders need to consider changing the ranking system, improving standardization of clerkships, and further studying relation to other variables to improve validity. This will be important across GME as more specialties adopt a standardized letter.


2021 ◽  
pp. 1-26
Author(s):  
Traci A. Bekelman ◽  
Corby K. Martin ◽  
Susan L. Johnson ◽  
Deborah H. Glueck ◽  
Katherine A. Sauder ◽  
...  

Abstract The limitations of self-report measures of dietary intake are well known. Novel, technology-based measures of dietary intake may provide a more accurate, less burdensome alternative to existing tools. The first objective of this study was to compare participant burden for two technology-based measures of dietary intake among school-age children: the Automated-Self Administered 24-hour Dietary Assessment Tool-2018 (ASA24-2018) and the Remote Food Photography Method (RFPM). The second objective was to compare reported energy intake for each method to the Estimated Energy Requirement for each child, as a benchmark for actual intake. Forty parent-child dyads participated in 2, 3-day dietary assessments: a parent proxy-reported version of the ASA24 and the RFPM. A parent survey was subsequently administered to compare satisfaction, ease of use and burden with each method. A linear mixed model examined differences in total daily energy intake (TDEI) between assessments, and between each assessment method and the EER. Reported energy intake was 379 kcal higher with the ASA24 than the RFPM (p=0.0002). Reported energy intake with the ASA24 was 231 kcal higher than the EER (p = 0.008). Reported energy intake with the RFPM did not differ significantly from the EER (difference in predicted means = −148 kcal, p = 0.09). Median satisfaction and ease of use scores were 5 out of 6 for both methods. A higher proportion of parents reported that the ASA24 was more time consuming than the RFPM (74.4% vs. 25.6%, p = 0.002). Utilization of both methods is warranted given their high satisfaction among parents.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gabriel Giacobone ◽  
Maria Victoria Tiscornia ◽  
Leila Guarnieri ◽  
Luciana Castronuovo ◽  
Sally Mackay ◽  
...  

Abstract Background Food cost and affordability is one of the main barriers to improve the nutritional quality of diets of the population. However, in Argentina, where over 60% of adults and 40% of children and adolescents are overweight or obese, little is known about the difference in cost and affordability of healthier diets compared to ordinary, less healthy ones. Methods We implemented the “optimal approach” proposed by the International Network for Food and Obesity/non-communicable diseases Research, Monitoring and Action Support (INFORMAS). We modelled the current diet and two types of healthy diets, one equal in energy with the current diet and one 6.3% lower in energy by linear programming. Cost estimations were performed by collecting food product prices and running a Monte Carlo simulation (10,000 iterations) to obtain a range of costs for each model diet. Affordability was measured as the percentage contribution of diet cost vs. average household income in average, poor and extremely poor households and by income deciles. Results On average, households must spend 32% more money on food to ensure equal energy intake from a healthy diet than from a current model diet. When the energy intake target was reduced by 6.3%, the difference in cost was 22%. There are no reasonably likely situations in which any of these healthy diets could cost less or the same than the current unhealthier one. Over 50% of households would be unable to afford the modelled healthy diets, while 40% could not afford the current diet. Conclusions Differential cost and affordability of healthy vs. unhealthy diets are germane to the design of effective public policies to reduce obesity and NCDs in Argentina. It is necessary to implement urgent measures to transform the obesogenic environment, making healthier products more affordable, available and desirable, and discouraging consumption of nutrient-poor, energy-rich foods.


AoB Plants ◽  
2021 ◽  
Author(s):  
Tiphaine Vidal ◽  
Hafssa Aissaoui ◽  
Sabrina Rehali ◽  
Bruno Andrieu

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.


2015 ◽  
Vol 23 (3) ◽  
pp. 485-498
Author(s):  
Martha R. Sleutel ◽  
Celestina Barbosa-Leiker ◽  
Marian Wilson

Background and Purpose: Evidence-based practice (EBP) is essential to optimal health care outcomes. Interventions to improve use of evidence depend on accurate assessments from reliable, valid, and user-friendly tools. This study reports psychometric analyses from a modified version of a widely used EBP questionnaire, the information literacy for nursing practice (ILNP). Methods: After content validity assessments by nurse researchers, a convenience sam ple of 2,439 nurses completed the revised 23-item questionnaire. We examined internal consistency and used factor analyses to assess the factor structure. Results: A modified 4-factor model demonstrated adequate fit to the data. Cronbach’s alpha was .80–.92 for the subscales. Conclusions: The shortened ILNP (renamed Healthcare EBP Assessment Tool or HEAT) demonstrated adequate content validity, construct validity, and reliability.


Geophysics ◽  
1965 ◽  
Vol 30 (3) ◽  
pp. 363-368 ◽  
Author(s):  
T. W. Spencer

The formal solution for an axially symmetric radiation field in a multilayered, elastic system can be expanded in an infinite series. Each term in the series is associated with a particular raypath. It is shown that in the long‐time limit the individual response functions produced by a step input in particle velocity are given by polynomials in odd powers of the time. For rays which suffer m reflections, the degree of the polynomials is 2m+1. The total response is obtained by summing all rays which contribute in a specified time interval. When the rays are selected indiscriminately, the difference between the magnitude of the partial sum at an intermediate stage of computation and the magnitude of the correct total sum may be greater than the number of significant figures carried by the computer. A prescription is stated for arranging the rays into groups. Each group response function varies linearly in the long‐time limit and goes to zero when convolved with a physically realizable source function.


1995 ◽  
Vol 268 (6) ◽  
pp. R1472-R1483 ◽  
Author(s):  
G. L. Gebber ◽  
S. Zhong ◽  
S. M. Barman

We used phase spectral analysis to study the relationships between the cardiac-related discharges of pairs of postganglionic sympathetic nerves in urethan-anesthetized or decerebrate cats. Phase angle when converted to a time interval should equal the difference in conduction times from the brain to the nerves (i.e., transportation lag) if their cardiac-related discharges have a common central source. Transportation lag was estimated as the difference in the onset latencies of activation of the nerves by electrical stimulation of the medulla or cervical spinal cord. The phase angle for the cardiac-related discharges of two nerves was not always equivalent in time to the transportation lag. For example, in some cases the cardiac-related discharges of the renal nerve were coincident with or led those of the inferior cardiac nerve. In contrast, the electrically evoked responses of the renal nerve lagged those of the inferior cardiac nerve by > or = 32 ms. These observations are consistent with a model of multiple and dynamically coupled brain stem generators of the cardiac-related rhythm, each controlling a different sympathetic nerve or exerting nonuniform influences on different portions of the spinal sympathetic outflow.


Author(s):  
R.J. Milner ◽  
F. Reyers ◽  
J.H. Taylor ◽  
J.S. Van den Berg

A clinical trial was designed to evaluate the effects of diminazene aceturate and its stabiliser antipyrine on serum pseudocholinesterase (PChE) and red blood cell acetylcholinesterase (RBC AChE) in dogs with babesiosis. The trial was conducted on naturally occurring, uncomplicated cases of babesiosis (n = 20) that were randomly allocated to groups receiving a standard therapeutic dose of diminazene aceturate with antipyrine stabiliser (n = 10) or antipyrine alone (n = 10). Blood was drawn immediately before and every 15 minutes for 1 hour after treatment. Plasma PChE showed a 4 % decrease between 0 and 60 min within the treatment group (p < 0.05). No statistically significant differences were found between the treatment and control groups at any of the time intervals for PChE. There was an increase in RBC AChE activity at 15 min in the treatment group (p < 0.05). No significant differences were found between the treatment and control groups at any time interval for RBC AChE. In view of the difference in PChE, samples from additional, new cases (n = 10) of canine babesiosis were collected to identify the affect of the drug over 12 hours. No significant depression was identified over this time interval. The results suggests that the underlying mechanism in producing side-effects, when they do occur, is unlikely to be through cholinesterase depression.


2017 ◽  
Vol 28 (75) ◽  
pp. 361-376 ◽  
Author(s):  
Leandro dos Santos Maciel ◽  
Rosangela Ballini

ABSTRACT This article considers range-based volatility modeling for identifying and forecasting conditional volatility models based on returns. It suggests the inclusion of range measuring, defined as the difference between the maximum and minimum price of an asset within a time interval, as an exogenous variable in generalized autoregressive conditional heteroscedasticity (GARCH) models. The motivation is evaluating whether range provides additional information to the volatility process (intraday variability) and improves forecasting, when compared to GARCH-type approaches and the conditional autoregressive range (CARR) model. The empirical analysis uses data from the main stock market indexes for the U.S. and Brazilian economies, i.e. S&P 500 and IBOVESPA, respectively, within the period from January 2004 to December 2014. Performance is compared in terms of accuracy, by means of value-at-risk (VaR) modeling and forecasting. The out-of-sample results indicate that range-based volatility models provide more accurate VaR forecasts than GARCH models.


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