Mathematical modeling in energy homeostasis, appetite control and food intake with a special attention to ghrelin

Mathematical modeling in energy homeostasis, appetite control and food intake with a special attention to ghrelin PDF Author: Jorge Guerra Pires
Publisher: Jorge Guerra Pires
ISBN:
Category : Science
Languages : en
Pages : 341

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Book Description
The elegant ‘interconnected mechanisms’ by which the gastrointestinal (GI) tract regulates food intake are a marvel of biology, but the redundancy (e.g., several hormones seem to have effects in food intake) of both GI (by means of hormones) and central nervous system (CNS, by means of satiety/satiation signals) pathways governing energy homeostasis poses formidable challenges for scientists trying to take a clear glimpse of this machinery, e.g. for designing anti-obesity and alike pharmaceuticals. In essence, notwithstanding the astonishing advancements made over the past few decades in unscrambling many of the molecular pathways involved in energy (homeostasis) regulation, a rather cloudy understanding of “how all the pieces fit together to function as an integrated system” is what can be found for the most part in the scientific community; we discuss that in part II of the work, in a single chapter divided in several sections for numerous imperative hormones, e.g. cholecystokinin. The current work is divided into three parts: part I is regarding fundamentals of physiology and mathematical modeling employed all over the work; part II is more generic and concerns several hormones (what we have called a “web of hormones”) and part III (divided into three chapters) is more specific, concerning a single hormone (i.e., ghrelin). The core of the work is part III, and to a certain extent part II, bearing mind we provide a literature review based on papers scattered/dispersed all over the medical science literature. The main objective of this work is proposing a mathematical model for ghrelin dynamics (Figure 70), a model centered on the gastrointestinal tract (stomach + small intestine, a two-compartment model), with daily-like dynamics, short-term dynamics; and, simultaneously, proposing a prototype for a systems biology like model (igure 40), a model based on numerous hormones, for understanding mathematically food intake/bodyweight control. Ghrelin is a quite powerful orexigenic hormone discovered in the late 1990s that controls appetite and energy homeostasis, alongside leptin and other hormones still to be investigated in depth by the medical sciences literature. Accordingly, we provide a (simple) mathematical model, consisting of a set of ordinary differential equations detailing ghrelin dynamics combined to gastrointestinal signals due to meals. Numerical simulations are able to replicate in silico available data from the literature; additionally, we were able to fit a reduced version of the basal model to experimental data. The model is developed as a module for a bigger potential multi-compartmental structure, detailing food and energy homeostasis within a sort of "a web of hormones" (see part II and the last chapter of part III). The present contribute is to recommend a primary mathematical model for ghrelin dynamics centered in the gastrointestinal tract, with potentiality to be applied also for postabsorptive states, left mainly as future works. We go on with the model by presenting mainly two variations, further unfolding is left as future endeavor: tastants and stochastic version. We test several optimization routines for the parameter estimation procedure, hybrid algorithms (global + local search), for parameter estimation, based on data published for humans (three meals a day). For all the routines, the best is a hybrid composed of simulating annealing as global search and pattern search as local search. In the objective function (sum of the squared errors, SSE), we apply artificial neural networks (a two-layer feedforward neural network) for generating new data from the data already published, a strategy adopted to increase the data set. In the last part of the chapter about ghrelin modeling (part III), we propose several prototypes for future works based on the basal models; the model used for parameter estimation is a “minimal/reduced” model; we also provide discussions and future works for the minimal model and parameter estimation. Key-words. Ghrelin; leptin; mathematical modelling; food intake; appetite; parameter estimation.

Mathematical modeling in energy homeostasis, appetite control and food intake with a special attention to ghrelin

Mathematical modeling in energy homeostasis, appetite control and food intake with a special attention to ghrelin PDF Author: Jorge Guerra Pires
Publisher: Jorge Guerra Pires
ISBN:
Category : Science
Languages : en
Pages : 341

Get Book Here

Book Description
The elegant ‘interconnected mechanisms’ by which the gastrointestinal (GI) tract regulates food intake are a marvel of biology, but the redundancy (e.g., several hormones seem to have effects in food intake) of both GI (by means of hormones) and central nervous system (CNS, by means of satiety/satiation signals) pathways governing energy homeostasis poses formidable challenges for scientists trying to take a clear glimpse of this machinery, e.g. for designing anti-obesity and alike pharmaceuticals. In essence, notwithstanding the astonishing advancements made over the past few decades in unscrambling many of the molecular pathways involved in energy (homeostasis) regulation, a rather cloudy understanding of “how all the pieces fit together to function as an integrated system” is what can be found for the most part in the scientific community; we discuss that in part II of the work, in a single chapter divided in several sections for numerous imperative hormones, e.g. cholecystokinin. The current work is divided into three parts: part I is regarding fundamentals of physiology and mathematical modeling employed all over the work; part II is more generic and concerns several hormones (what we have called a “web of hormones”) and part III (divided into three chapters) is more specific, concerning a single hormone (i.e., ghrelin). The core of the work is part III, and to a certain extent part II, bearing mind we provide a literature review based on papers scattered/dispersed all over the medical science literature. The main objective of this work is proposing a mathematical model for ghrelin dynamics (Figure 70), a model centered on the gastrointestinal tract (stomach + small intestine, a two-compartment model), with daily-like dynamics, short-term dynamics; and, simultaneously, proposing a prototype for a systems biology like model (igure 40), a model based on numerous hormones, for understanding mathematically food intake/bodyweight control. Ghrelin is a quite powerful orexigenic hormone discovered in the late 1990s that controls appetite and energy homeostasis, alongside leptin and other hormones still to be investigated in depth by the medical sciences literature. Accordingly, we provide a (simple) mathematical model, consisting of a set of ordinary differential equations detailing ghrelin dynamics combined to gastrointestinal signals due to meals. Numerical simulations are able to replicate in silico available data from the literature; additionally, we were able to fit a reduced version of the basal model to experimental data. The model is developed as a module for a bigger potential multi-compartmental structure, detailing food and energy homeostasis within a sort of "a web of hormones" (see part II and the last chapter of part III). The present contribute is to recommend a primary mathematical model for ghrelin dynamics centered in the gastrointestinal tract, with potentiality to be applied also for postabsorptive states, left mainly as future works. We go on with the model by presenting mainly two variations, further unfolding is left as future endeavor: tastants and stochastic version. We test several optimization routines for the parameter estimation procedure, hybrid algorithms (global + local search), for parameter estimation, based on data published for humans (three meals a day). For all the routines, the best is a hybrid composed of simulating annealing as global search and pattern search as local search. In the objective function (sum of the squared errors, SSE), we apply artificial neural networks (a two-layer feedforward neural network) for generating new data from the data already published, a strategy adopted to increase the data set. In the last part of the chapter about ghrelin modeling (part III), we propose several prototypes for future works based on the basal models; the model used for parameter estimation is a “minimal/reduced” model; we also provide discussions and future works for the minimal model and parameter estimation. Key-words. Ghrelin; leptin; mathematical modelling; food intake; appetite; parameter estimation.

Regulation of Body Weight

Regulation of Body Weight PDF Author: Claude Bouchard
Publisher:
ISBN:
Category : Medical
Languages : en
Pages : 352

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Book Description
The fact that about 30-40% of the adults in the Western world are overweight or obese testifies to the frequency of the disturbances in body weight regulation. Scientists have established that caloric intake, macronutrient composition of the diet, basal and resting metabolic rate, thermic response to food, energy expenditure associated with movement and physical activity, and preferential storage of the surplus of calories as fat or lean tissues are critical determinants of energy balance and body weight. While much has been learned, the field is poised for major advances with the advent of a variety of imaging techniques, progress in quantitative and molecular genetics, use of transgenic rodent models and of breeding experiments with informative inbred strains, availability of stable isotopes for metabolic and behavioral studies, and a growing number of useful experimental animal and human models. This volume takes an integrative approach to obesity. It is structured around four major topics: (1) the animal and human models currently available for the study of body weight regulation with their strengths and limitations, (2) the molecular and genetic basis of the regulation of body weight, (3) the metabolic and physiological mechanisms involved, and (4) the behavioral and social determinants. The 13 background papers provide a critical overview of the present knowledge base while the group reports summarize the extensive deliberations of 38 international experts. Particular emphasis has been given to promising research areas and on the advances needed to ensure a better understanding of the biological and behavioral mechanisms of the regulation of body weight, with a particular emphasis on overweight and obesity.

Active Inference

Active Inference PDF Author: Thomas Parr
Publisher: MIT Press
ISBN: 0262362287
Category : Science
Languages : en
Pages : 313

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Book Description
The first comprehensive treatment of active inference, an integrative perspective on brain, cognition, and behavior used across multiple disciplines. Active inference is a way of understanding sentient behavior—a theory that characterizes perception, planning, and action in terms of probabilistic inference. Developed by theoretical neuroscientist Karl Friston over years of groundbreaking research, active inference provides an integrated perspective on brain, cognition, and behavior that is increasingly used across multiple disciplines including neuroscience, psychology, and philosophy. Active inference puts the action into perception. This book offers the first comprehensive treatment of active inference, covering theory, applications, and cognitive domains. Active inference is a “first principles” approach to understanding behavior and the brain, framed in terms of a single imperative to minimize free energy. The book emphasizes the implications of the free energy principle for understanding how the brain works. It first introduces active inference both conceptually and formally, contextualizing it within current theories of cognition. It then provides specific examples of computational models that use active inference to explain such cognitive phenomena as perception, attention, memory, and planning.

Principles of Nutrigenetics and Nutrigenomics

Principles of Nutrigenetics and Nutrigenomics PDF Author: Raffaele De Caterina
Publisher: Academic Press
ISBN: 0128045876
Category : Medical
Languages : en
Pages : 588

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Book Description
Principles of Nutrigenetics and Nutrigenomics: Fundamentals for Individualized Nutrition is the most comprehensive foundational text on the complex topics of nutrigenetics and nutrigenomics. Edited by three leaders in the field with contributions from the most well-cited researchers conducting groundbreaking research in the field, the book covers how the genetic makeup influences the response to foods and nutrients and how nutrients affect gene expression. Principles of Nutrigenetics and Nutrigenomics: Fundamentals for Individualized Nutrition is broken into four parts providing a valuable overview of genetics, nutrigenetics, and nutrigenomics, and a conclusion that helps to translate research into practice. With an overview of the background, evidence, challenges, and opportunities in the field, readers will come away with a strong understanding of how this new science is the frontier of medical nutrition. Principles of Nutrigenetics and Nutrigenomics: Fundamentals for Individualized Nutrition is a valuable reference for students and researchers studying nutrition, genetics, medicine, and related fields. - Uniquely foundational, comprehensive, and systematic approach with full evidence-based coverage of established and emerging topics in nutrigenetics and nutrigenomics - Includes a valuable guide to ethics for genetic testing for nutritional advice - Chapters include definitions, methods, summaries, figures, and tables to help students, researchers, and faculty grasp key concepts - Companion website includes slide decks, images, questions, and other teaching and learning aids designed to facilitate communication and comprehension of the content presented in the book

The Tiger That Isn't

The Tiger That Isn't PDF Author: Andrew Dilnot
Publisher: Profile Books
ISBN: 1847650791
Category : Mathematics
Languages : en
Pages : 237

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Book Description
Mathematics scares and depresses most of us, but politicians, journalists and everyone in power use numbers all the time to bamboozle us. Most maths is really simple - as easy as 2+2 in fact. Better still it can be understood without any jargon, any formulas - and in fact not even many numbers. Most of it is commonsense, and by using a few really simple principles one can quickly see when maths, statistics and numbers are being abused to play tricks - or create policies - which can waste millions of pounds. It is liberating to understand when numbers are telling the truth or being used to lie, whether it is health scares, the costs of government policies, the supposed risks of certain activities or the real burden of taxes.

High Calorie Diet and the Human Brain

High Calorie Diet and the Human Brain PDF Author: Akhlaq A. Farooqui
Publisher: Springer
ISBN: 3319152548
Category : Medical
Languages : en
Pages : 325

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Book Description
The purpose of this monograph is to present readers with a comprehensive and cutting edge description of neurochemical effects of diet (beneficial and harmful effects) in normal human brain and to discuss how present day diet promotes pathogenesis of stroke, AD, PD, and depression in a manner that is useful not only to students and teachers but also to researchers, dietitians, nutritionists and physicians. A diet in sufficient amount and appropriate macronutrients is essential for optimal health of human body tissues. In brain, over-nutrition, particularly with high-calorie diet, not only alters cellular homeostasis, but also results in changes in the intensity of signal transduction processes in reward centers of the brain resulting in food addiction. Over-nutrition produces detrimental effects on human health in general and brain health in particular because it chronically increases the systemic and brain inflammation and oxidative stress along with induction of insulin resistance and leptin resistance in the brain as well as visceral organs. Onset of chronic inflammation and oxidative stress not only leads to obesity and heart disease, but also promotes type II diabetes and metabolic syndrome, which are risk factors for both acute neural trauma (stroke) and chronic age-related neurodegenerative and neuropsychological disorders, such as Alzheimer disease (AD), Parkinson disease (PD) and depression.

Appetite and Body Weight

Appetite and Body Weight PDF Author: Tim Kirkham
Publisher: Elsevier
ISBN: 008046646X
Category : Science
Languages : en
Pages : 385

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Book Description
There is now enough basic work to sketch out the principal systems at all levels of the brain, from prefrontal cortex to lower brainstem, which are orchestrated to provide control of food selection, preference and consumption. At the same time, the complex interplay between central systems and signals generated from peripheral systems include the gut, liver and fat stores, as well as the interactions with the neuroendocrine system can be described in some detail. A continuing theme throughout the book is that the functional analysis of appetite and food intake cannot be limited to a single focus, e.g. hypothalamic neuropeptides and their interactions, but must be based on a fully integrated view of the several contributing systems. Appetite and Body Weight: Integrative Systems and the Development of Anti-Obesity Drugs provides an expert guide to the neural, neurochemical, autonomic and endocrine interrelations which underpin appetite and the controls of food intake and body weight. The book covers many of the neurochemical entities that are currently under investigation, including: neuropeptides, leptin, insulin, monoamines and endogenous cannabinoids in relation to appetite and body-weight control. In addition to the neuroscience analysis, there are also chapters that provide an expert guide to some of the key psychological concepts that the researchers believe are essential in trying to understand the phenomena under investigation. The volume will also serve as an authoritative guide to the current emphasis on the development of novel, efficacious anti-obesity medication. - Provides an integrative view of the many systems involved in appetite how they interact to effect food intake (i.e. the brain, endocrine, gut, liver etc.) - Considers psychological aspects such as incentive, preference, liking and palatability, and sets these concepts in their behavioural, pharmacological and neural contexts - Examines the development of novel anti-obesity drugs, drawing on experience of pharmacological development work, pre-clinical tests for anti-obesity efficacy, and clinical trials of candidate anti-obesity compounds

Nutrition and Cardiometabolic Health

Nutrition and Cardiometabolic Health PDF Author: Nathalie Bergeron
Publisher: CRC Press
ISBN: 1351645722
Category : Medical
Languages : en
Pages : 781

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Book Description
Nutrition plays a key role in prevention of cardiovascular disease, the leading cause of death worldwide. Diet influences a broad spectrum of cardiometabolic risk factors, notably a cluster including excess adiposity, dyslipidemia, impaired glucose metabolism and high blood pressure. In the face of the rapidly increasing incidence of obesity and diabetes, maintaining cardiometabolic health through adoption of a healthy lifestyle is a top public health priority. In this book, Nutrition and Cardiometabolic Health, international experts present state-of-the-art scholarly reviews of dietary and lifestyle effects on metabolic systems associated with cardiovascular health and disease. It covers a broad range of topics including biological and behavioral processes regulating food intake; lifestyle and surgical approaches to weight loss; nutritional considerations for optimal cardiometabolic health across the lifespan; the relationship of macronutrients, whole foods and dietary patterns to diabetes and cardiovascular disease; and diet as a modulator of gene expression, epigenetics and the gut microbiome and the relationship of these traits to disorders of metabolism. This book provides its readers with an authoritative view of the present state of knowledge of dietary effects on cardiometabolic health and will be of interest to nutrition and healthcare professionals alike.

Methods in Consumer Research, Volume 2

Methods in Consumer Research, Volume 2 PDF Author: Gaston Ares
Publisher: Woodhead Publishing
ISBN: 0081017448
Category : Technology & Engineering
Languages : en
Pages : 498

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Book Description
Methods for Consumer Research, Volume Two: Alternative Approaches and Special Applications brings together world leading experts in global consumer research who provide a fully comprehensive state-of-the-art coverage of emerging methodologies and their innovative application. The book puts consumer research in-context with coverage of immersive techniques and virtual reality, while also looking at health-related Issues in consumer science, including sections on food intake and satiation. Other sections delve into physiological measurements within the context of consumer research and how to design studies for specific populations. In conjunction with the first volume, which covers new approaches to classical methodology, this book is an invaluable reference for academics working in the fields of in-sensory and consumer science, psychology, marketing and nutrition. With examples of the methodology being applied throughout, it serves as a practical guide to research and development managers in both food and non-food companies. - Presents comprehensive coverage of new and emerging techniques in consumer science - Provides examples of successful application of the methodologies presented throughout - Identifies how to design research for special populations, including children, the elderly and low-income consumers - Discusses sensitivity to cross-cultural populations and emerging markets - Includes research design for food, cosmetic and household products - Highlights both psychological and physiological consumer measurements

Polycystic Ovary Syndrome

Polycystic Ovary Syndrome PDF Author: Andrea Dunaif
Publisher: Springer Science & Business Media
ISBN: 1597451088
Category : Medical
Languages : en
Pages : 361

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Book Description
This volume includes the latest diagnostic criteria for PCOS and comprises the most up-to-date information about the genetic features and pathogenesis of PCOS. It critically reviews the methodological approaches and the evidence for various PCOS susceptibility genes. The book also discusses additional familial phenotypes of PCOS and their potential genetic basis. All four editors of this title are extremely prominent in the field of PCOS.