scholarly journals Energy Balance and Control of Body Weight: Possible Effects of Meal Timing and Circadian Rhythm Dysregulation

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3276
Author(s):  
Alessio Basolo ◽  
Susanna Bechi Genzano ◽  
Paolo Piaggi ◽  
Jonathan Krakoff ◽  
Ferruccio Santini

Conservation of the energy equilibrium can be considered a dynamic process and variations of one component (energy intake or energy expenditure) cause biological and/or behavioral compensatory changes in the other part of the system. The interplay between energy demand and caloric intake appears designed to guarantee an adequate food supply in variable life contexts. The circadian rhythm plays a major role in systemic homeostasis by acting as “timekeeper” of the human body, under the control of central and peripheral clocks that regulate many physiological functions such as sleep, hunger and body temperature. Clock-associated biological processes anticipate the daily demands imposed by the environment, being synchronized under ideal physiologic conditions. Factors that interfere with the expected demand, including daily distribution of macronutrients, physical activity and light exposure, may disrupt the physiologic harmony between predicted and actual behavior. Such a desynchronization may favor the development of a wide range of disease-related processes, including obesity and its comorbidities. Evidence has been provided that the main components of 24-h EE may be affected by disruption of the circadian rhythm. The sleep pattern, meal timing and meal composition could mediate these effects. An increased understanding of the crosstalk between disruption of the circadian rhythm and energy balance may shed light on the pathophysiologic mechanisms underlying weight gain, which may eventually lead to design effective strategies to fight the obesity pandemic.

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251478
Author(s):  
Jiawei Yin ◽  
A. Agung Julius ◽  
John T. Wen

The circadian rhythm, called Process C, regulates a wide range of biological processes in humans including sleep, metabolism, body temperature, and hormone secretion. Light is the dominant synchronizer of the circadian rhythm—it has been used to regulate the circadian phase to cope with jet-lag, shift work, and sleep disorder. The homeostatic oscillation of the sleep drive is called Process S. Process C and Process S together determine the sleep-wake cycle in what is known as the two-process model. This paper addresses the regulation of both Process C and Process S by scheduling light exposure and sleep based on numerical simulations of circadian rhythm and sleep mathematical models. This is a significant step beyond the existing literature that only considers the entrainment of Process C. Regulation of the two-process model poses several unique features and challenges: 1. Process S is non-smooth, i.e., the homeostatic dynamics are different in the sleep and wake regimes; 2. Light only indirectly affects Process S through Process C; 3. Light does not affect Process C during sleep. We consider two scenarios: optimizing light intensity as the control input with spontaneous (i.e., unscheduled) sleep/wake times and jointly optimizing the light intensity and the sleep/wake times, which allows limited delayed sleep and early waking as part of the decision variables. We solve the time-optimal entrainment problem for the two-process model for both scenarios using an extension of the gradient descent algorithm to non-smooth systems. To illustrate the efficacy of our time-optimal entrainment strategies, we consider two common use cases: transmeridian travelers and shift workers. For transmeridian travelers, joint optimization of the two-process model avoids the unrealistic long wake duration when only Process C is considered. The entrainment time also decreases when both the light input and the sleep schedule are optimized compared to when only the light input is optimized. For shift workers, we show that the entrainment time is significantly shortened by optimizing the night shift working light.


2018 ◽  
pp. S409-S420 ◽  
Author(s):  
B. RÁCZ ◽  
M. DUŠKOVÁ ◽  
L. STÁRKA ◽  
V. HAINER ◽  
M. KUNEŠOVÁ

Obesity is linked to a wide range of serious illnesses. In addition to the important impact on the health of the individual, obesity also has a substantial impact on the economy. Disruption of physiological day-night cycles could contribute to the increased incidence of obesity. According to the American National Sleep Federation, the percentage of the people who reported a sleep duration of six hours or less increased from 12 to 37 % over ten years. Insufficient sleep leads not only to an increase of the total calorie intake but changes the meal preference in favor of palatable foods and meals with high carbohydrate content. A decrease of leptin and increase of ghrelin levels caused by sleep deficiency can also play a role. In addition to the higher caloric intake, the timing of food consumption should be taken into account. The same meal eaten during the night versus the day is associated with increased postprandial glucose and triglyceride levels. The gut microbiome has also been recently understood as an endocrine system, with links between the gut microbiome and circadian rhythm changes possibly influencing increased obesity.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Martin Pullinger ◽  
Jonathan Kilgour ◽  
Nigel Goddard ◽  
Niklas Berliner ◽  
Lynda Webb ◽  
...  

AbstractThe IDEAL household energy dataset described here comprises electricity, gas and contextual data from 255 UK homes over a 23-month period ending in June 2018, with a mean participation duration of 286 days. Sensors gathered 1-second electricity data, pulse-level gas data, 12-second temperature, humidity and light data for each room, and 12-second temperature data from boiler pipes for central heating and hot water. 39 homes also included plug-level monitoring of selected electrical appliances, real-power measurement of mains electricity and key sub-circuits, and more detailed temperature monitoring of gas- and heat-using equipment, including radiators and taps. Survey data included occupant demographics, values, attitudes and self-reported energy awareness, household income, energy tariffs, and building, room and appliance characteristics. Linked secondary data comprises weather and level of urbanisation. The data is provided in comma-separated format with a custom-built API to facilitate usage, and has been cleaned and documented. The data has a wide range of applications, including investigating energy demand patterns and drivers, modelling building performance, and undertaking Non-Intrusive Load Monitoring research.


Author(s):  
Lionel Roques ◽  
Mickaël D. Chekroun ◽  
Michel Cristofol ◽  
Samuel Soubeyrand ◽  
Michael Ghil

We study parameter estimation for one-dimensional energy balance models with memory (EBMMs) given localized and noisy temperature measurements. Our results apply to a wide range of nonlinear, parabolic partial differential equations with integral memory terms. First, we show that a space-dependent parameter can be determined uniquely everywhere in the PDE's domain of definition D , using only temperature information in a small subdomain E ⊂ D . This result is valid only when the data correspond to exact measurements of the temperature. We propose a method for estimating a model parameter of the EBMM using more realistic, error-contaminated temperature data derived, for example, from ice cores or marine-sediment cores. Our approach is based on a so-called mechanistic-statistical model that combines a deterministic EBMM with a statistical model of the observation process. Estimating a parameter in this setting is especially challenging, because the observation process induces a strong loss of information. Aside from the noise contained in past temperature measurements, an additional error is induced by the age-dating method, whose accuracy tends to decrease with a sample's remoteness in time. Using a Bayesian approach, we show that obtaining an accurate parameter estimate is still possible in certain cases.


Author(s):  
R. Gaudron ◽  
D. Yang ◽  
A. S. Morgans

Abstract Thermoacoustic instabilities can occur in a wide range of combustors and are prejudicial since they can lead to increased mechanical fatigue or even catastrophic failure. A well-established formalism to predict the onset, growth and saturation of such instabilities is based on acoustic network models. This approach has been successfully employed to predict the frequency and amplitude of limit cycle oscillations in a variety of combustors. However, it does not provide any physical insight in terms of the acoustic energy balance of the system. On the other hand, Rayleigh’s criterion may be used to quantify the losses, sources and transfers of acoustic energy within and at the boundaries of a combustor. However, this approach is cumbersome for most applications because it requires computing volume and surface integrals and averaging over an oscillation cycle. In this work, a new methodology for studying the acoustic energy balance of a combustor during the onset, growth and saturation of thermoacoustic instabilities is proposed. The two cornerstones of this new framework are the acoustic absorption coefficient Δ and the cycle-to-cycle acoustic energy ratio λ, both of which do not require computing integrals. Used along with a suitable acoustic network model, where the flame frequency response is described using the weakly nonlinear Flame Describing Function (FDF) formalism, these two dimensionless numbers are shown to characterize: 1) the variation of acoustic energy stored within the combustor between two consecutive cycles, 2) the acoustic energy transfers occurring at the combustor’s boundaries and 3) the sources and sinks of acoustic energy located within the combustor. The acoustic energy balance of the well-documented Palies burner is then analyzed during the onset, growth and saturation of thermoacoustic instabilities using this new methodology. It is demonstrated that this new approach allows a deeper understanding of the physical mechanisms at play. For instance, it is possible to determine when the flame acts as an acoustic energy source or sink, where acoustic damping is generated, and if acoustic energy is transmitted through the boundaries of the burner.


2021 ◽  
Vol 19 (2) ◽  
pp. 34-38
Author(s):  
A. S. SAMOYLOV ◽  
◽  
N. V. RYLOVA ◽  
A. V. ZHOLINSKIY ◽  
I. V. BOLSHAKOV ◽  
...  

The article presents data from the Russian and foreign literature of the properties of melatonin, its role in the vital activity of the body and the regulation of circadian rhythms. The features of using the drug in desynchronosis, the optimal dosage and time of administration, as well as the possibility of its use in combination with non-pharmacological treatment methods are discussed. These methods include dosed light exposure and exercise. Additionally, new studies are considered, indicating the beneficial effect of melatonin and its agonists on the immune, cardiovascular, endocrine and nervous systems. Based on the collected data, it is asserted that melatonin can significantly accelerate the process of adaptation to a new time zone without the development of side effects. Therefore, this drug is the most effective and safe treatment for desynchronosis. It is also important to note that the study of the multifaceted effects of melatonin on body functions opens up great prospects in the treatment of many diseases.


2021 ◽  
Vol 92 (2) ◽  
pp. 10-20
Author(s):  
A. V Kiriakova ◽  
◽  
V.V. Moroz ◽  

Interest in creativity as a subject of research has been growing exponentially since the second half of the 20th century in all areas of human history. A wide range of both domestic and foreign studies allows authors to assert that creativity is a personality trait, inherent to one degree or another. Whereas the development of such trait becomes an urgent necessity in the new reality. The entire evolutionary process of the social development illustrates its dependence on personal and collective creativity. The aim of this research is to study the phenomenon of creativity through the perspective of axiology, i.e. the science of values. Axiology allows us to consider the realities of the modern world from the perspective of not only external factors, circumstances and situations, but also of deep value foundations. Creativity has been studied quite deeply from the point of view of psychology: the special characteristics of a creative person, stages of the creative process, the relationship between creative and critical thinking, creativity and intelligence. Some psychologists emphasize motivation, creative skills, interdisciplinary knowledge, and the creative environment as the main components that contribute to the development of creativity. The authors of the article argue that values and value orientations towards cognition, creativity, self-realization and self-expression are the drivers of creativity. In a broad sense, values as a matrix of culture determine the attitude of society to creativity, to the development of creativity of the individual and the creative class, and to how economically successful a given society will be. Since innovation and entrepreneurship are embodied creativity. Thus, the study of creativity from the perspective of axiology combines the need for a deep study of this phenomenon and the subjective significance of creativity in the context of new realities


1982 ◽  
Vol 27 (7) ◽  
pp. 543-545
Author(s):  
Philip Barker

The two main components of child psychiatric training should be supervised clinical work of high quality and training in the questing, scientific approach to the subject. These should be combined so that residents consider the assessment and management of all their clinical cases in a critical way, at the same time looking critically also at the pertinent literature. Management and treatment methods should be selected in the context of discussion of the current state of knowledge in the area. Trainees should see and treat children and adolescents of all ages and with the full range of psychiatric disorders. Ten percent of their caseload should consist of mentally retarded children. It may be necessary to teach about some rare syndromes by the use of videotapes. Residents should be familiar with the uses, and drawbacks, of a wide range of therapies, including residential treatment, but can only be expected to develop special expertise in a few. Didactic teaching unrelated to clinical work is probably of limited value.


2019 ◽  
Author(s):  
Bouchra Ait Hssaine ◽  
Olivier Merlin ◽  
Jamal Ezzahar ◽  
Nitu Ojha ◽  
Salah Er-raki ◽  
...  

Abstract. Thermal-based two-source energy balance modeling is very useful for estimating the land evapotranspiration (ET) at a wide range of spatial and temporal scales. However, the land surface temperature (LST) is not sufficient for constraining simultaneously both soil and vegetation flux components in such a way that assumptions (on either the soil or the vegetation fluxes) are commonly required. To avoid such assumptions, a new energy balance model (TSEB-SM) was recently developed in Ait Hssaine et al. (2018a) to integrate the microwave-derived near-surface soil moisture (SM), in addition to the thermal-derived LST and vegetation cover fraction (fc). Whereas, TSEB-SM has been recently tested using in-situ measurements, the objective of this paper is to evaluate the performance of TSEB-SM in real-life using 1 km resolution MODIS (Moderate resolution imaging spectroradiometer) LST and fc data and the 1 km resolution SM data disaggregated from SMOS (Soil Moisture and Ocean Salinity) observations by using DisPATCh. The approach is applied during a four-year period (2014–2018) over a rainfed wheat field in the Tensift basin, central Morocco, during a four-year period (2014–2018). The field was seeded for the 2014–2015 (S1), 2016–2017 (S2) and 2017–2018 (S3) agricultural season, while it was not ploughed (remained as bare soil) during the 2015–2016 (B1) agricultural season. The mean retrieved values of (arss, brss) calculated for the entire study period using satellite data are (7.32, 4.58). The daily calibrated αPT ranges between 0 and 1.38 for both S1 and S2. Its temporal variability is mainly attributed to the rainfall distribution along the agricultural season. For S3, the daily retrieved αPT remains at a mostly constant value (∼ 0.7) throughout the study period, because of the lack of clear sky disaggregated SM and LST observations during this season. Compared to eddy covariance measurements, TSEB driven only by LST and fc data significantly overestimates latent heat fluxes for the four seasons. The overall mean bias values are 119, 94, 128 and 181 W/m2 for S1, S2, S3 and B1 respectively. In contrast, these errors are much reduced when using TSEB-SM (SM and LST combined data) with the mean bias values estimated as 39, 4, 7 and 62 W/m2 for S1, S2, S3 and B1 respectively.


Author(s):  
Joachim Kersten ◽  
Catharina Vogt ◽  
Branko Lobnikar

The introductory chapter of this book presents the book's structure as a whole and gives a brief overview of its single chapters and their interrelatedness. The aim of IMPRODOVA - Improving Frontline Responses toHigh Impact Domestic Violence was to deliver recommendations, toolkits and collaborative training for European police organisations and medical and social work professionals to improve and integrate theinstitutional response to high-impact domestic violence. IMPRODOVA had two main components: analysis of current institutional responses to high-impact domestic violence and the development of effectivesolutions to improve those responses. Efforts were made to avoid a one-size-fits-all approach and contextualise our solutions, tools and guidelines to make them applicable to a wide range of societies.


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