The biology of appetite control: Do resting metabolic rate and fat-free mass drive energy intake?

The prevailing model of homeostatic appetite control envisages two major inputs; signals from adipose tissue and from peptide hormones in the gastrointestinal tract. This model is based on the presumed major influence of adipose tissue on food intake. However, recent studies have indicated that in obese people fat-free mass (FFM) is strongly positively associated with daily energy intake and with meal size. This effect has been replicated in several independent groups varying in cultural and ethnic backgrounds, and appears to be a robust phenomenon. In contrast fat mass (FM) is weakly, or mildly negatively associated with food intake in obese people. In addition resting metabolic rate (RMR), a major component of total daily energy expenditure, is also associated with food intake. This effect has been replicated in different groups and is robust. This action is consistent with the proposal that energy requirements — reflected in RMR (and other aspects of energy expenditure) constitute a biological drive to eat. Consistent with its storage function, FM has a strong inhibitory effect on food intake in lean subjects, but this effect appears to weaken dramatically as adipose tissue increases. This formulation can account for several features of the development and maintenance of obesity and provides an alternative, and transparent, approach to the biology of appetite control

Contract Farming, Ecological Change and the Transformations of Reciprocal Gendered Social Relations in Eastern India

Debates on gender and the commodification of land highlight the loss of land rights, intensification of demands on women’s labour, and decline in their decision-making control. Supported by ‘extra-economic forces’ of religious nationalism (Hindutva), such neoliberal interventions are producing new gender ideologies involving a subtle shift from relations of reciprocity to those of subordination. Using data from fine grained fieldwork in Koraput district, Odisha, we analyse the tensions and transformations created jointly by corporate interventions (contract farming of eucalyptus by the paper industry) and religious nationalism in the local landscape. We examine how these phenomena are reshaping relations of asymmetric mutuality between nature and society, and between men and women

Association between knee alignment and knee pain in patients surgically treated for medial knee osteoarthritis by high tibial osteotomy. A one year follow-up study

<p>Abstract</p> <p>Background</p> <p>The association between knee alignment and knee pain in knee osteoarthritis (OA) is unclear. High tibial osteotomy, a treatment option in knee OA, alters load from the affected to the unaffected compartment of the knee by correcting malalignment. This surgical procedure thus offers the possibility to study the cross-sectional and longitudinal association of alignment to pain. The aims were to study 1) the preoperative association of knee alignment to preoperative knee pain and 2) the association of change in knee alignment with surgery to change in knee pain over time in patients operated on for knee OA by high tibial osteotomy.</p> <p>Methods</p> <p>182 patients (68% men) mean age 53 years (34 - 69) with varus alignment having tibial osteotomy by the hemicallotasis technique for medial knee OA were consecutively included. Knee alignment was assessed by the Hip-Knee-Ankle (HKA) angle from radiographs including the hip and ankle joints. Knee pain was measured by the subscale pain (0 - 100, worst to best scale) of the Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and at one year follow-up. To estimate the association between knee alignment and knee pain multivariate regression analyses were used.</p> <p>Results</p> <p>Mean preoperative varus alignment was 170 degrees (153 - 178) and mean preoperative KOOS pain was 42 points (3 - 86). There was no association between preoperative varus alignment and preoperative KOOS pain, crude analysis 0.02 points (95% CI -0.6 - 0.7) change in pain with every degree of HKA angle, adjusted analysis 0.3 points (95% CI -1.3 - 0.6).</p> <p>The mean postoperative knee alignment was 184 degrees (171 - 185). The mean change in knee alignment was 13 degrees (0 - 30). The mean change in KOOS pain was 32 (-16 - 83). There was neither any association between change in knee alignment and change in KOOS pain over time, crude analysis 0.3 point (95% CI -0.6 - 1.2), adjusted analysis 0.4 points (95% CI 0.6 - 1.4).</p> <p>Conclusion</p> <p>We found no association between knee alignment and knee pain in patients with knee OA indicating that alignment and pain are separate entities, and that the degree of preoperative malalignment is not a predictor of knee pain after high tibial osteotomy.</p

The Psychobiology of Hunger – A Scientific Perspective

From a scientific perspective, hunger can be regarded as an identifiable conscious sensation which can be distinguished from other conscious states (e.g., pain, fear). The hunger state can be measured and is a marker of the existence of underlying biological processes. Measured hunger is functional and is normally associated with the act of eating. However, the conscious state of hunger, although driven physiologically, is not exclusively determined by biology; there is an environmental influence that can modulate its intensity and periodicity, and cultural factors that shape the appropriateness of the expression of hunger. Within a psychobiological framework, hunger can be considered as the expression of a ‘need state’ which mediates between biological requirements and environmental (nutritional) satisfaction. Our empirical studies show that hunger is clearly associated with biological signals (e.g., resting metabolic rate and some gastrointestinal peptides) and is central to the relationship between energy expenditure and energy intake

Reducing Calorie Intake May Not Help You Lose Body Weight

Background Previously a meta-analysis found that multi-vitamin/mineral supplementation reduced mild psychiatric symptoms. To establish mechanisms, and to pin-point the individuals most likely to benefit, the role of various polymorphisms were examined. Supplementation was found to influence mild-psychiatric symptoms depending on the form of particular genes: genes that are risk factors for psychiatric disease and influence mechanisms by which drugs act. Methods In a double-blind trial young healthy males rated psychiatric symptoms, before and after taking vitamin/mineral supplements for three months, and the response was related to single nucleotide polymorphisms associated with catecholamines and serotonin. Outcomes With rs1800497 (Taq1A; dopamine D2 receptor), those with the CT allele benefitted from a vitamin/mineral supplement. Similarly with rs1800955 (DRD4 – dopamine D4 receptor), the mood of those with the CC allele benefitted selectively. With rs6296 (HTR1B) only those with the GC alleles responded, and with rs6311 (HTR2A) supplementation produced a beneficial response in those with the GG allele. With rs1050565 (5HTT gene - Human Serotonin Transporter gene) supplementation increased the mental health of those with the AA allele. Interpretation In a situation where a substantial proportion of patients do not benefit from drug therapy, and there is an element of trial and error when prescribing, it was proposed that future work should consider distinguishing patients depending on various polymorphisms and micro-nutrient status. In those with particular alleles, we should consider if drug administration and vitamin / mineral status interact synergistically to influence the therapeutic outcom

Absolute Single-Molecule Entropies from Quasi-Harmonic Analysis of Microsecond Molecular Dynamics: Correction Terms and Convergence Properties

The convergence properties of the absolute single-molecule configurational entropy and the correction terms used to estimate it are investigated using microsecond molecular dynamics simulation of a peptide test system and an improved methodology. The results are compared with previous applications for systems of diverse chemical nature. It is shown that (i) the effect of anharmonicity is small, (ii) the effect of pairwise correlation is typically large, and (iii) the latter affects to a larger extent the entropy estimate of thermodynamic states characterized by a higher motional correlation. The causes of such deviations from a quasi-harmonic behavior are explained. This improved approach provides entropies also for molecular systems undergoing conformational transitions and characterized by highly frustrated energy surfaces, thus not limited to systems sampling a single quasi-harmonic basin. Overall, this study emphasizes the need for extensive phase-space sampling in order to obtain a reliable estimation of entropic contributions

Neuer Kopf, alte Ideen? : "Normalisierung" des Front National unter Marine Le Pen

In this article, it is investigated whether vibrational entropy (VE) is an important contribution to the free energy of globular proteins at ambient conditions. VE represents the major configurational-entropy contribution of these proteins. By definition, it is an average of the configurational entropies of the protein within single minima of the energy landscape, weighted by their occupation probabilities. Its large part originates from thermal motion of flexible torsion angles giving rise to the finite peak widths observed in torsion angle distributions. While VE may affect the equilibrium properties of proteins, it is usually neglected in numerical calculations as its consideration is difficult. Moreover, it is sometimes believed that all well-packed conformations of a globular protein have similar VE anyway. Here, we measure explicitly the VE for six different conformations from simulation data of a test protein. Estimates are obtained using the quasi-harmonic approximation for three coordinate sets, Cartesian, bond-angle-torsion (BAT), and a new set termed rotamer-degeneracy lifted BAT coordinates by us. The new set gives improved estimates as it overcomes a known shortcoming of the quasi-harmonic approximation caused by multiply populated rotamer states, and it may serve for VE estimation of macromolecules in a very general context. The obtained VE values depend considerably on the type of coordinates used. However, for all coordinate sets we find large entropy differences between the conformations, of the order of the overall stability of the protein. This result may have important implications on the choice of free energy expressions used in software for protein structure prediction, protein design, and NMR refinement

Expanding understanding of service exchange and value co-creation: A social construction approach

According to service-dominant logic (S-D logic), all providers are service providers, and service is the fundamental basis of exchange. Value is co-created with customers and assessed on the basis of value-in-context. However, the extensive literature on S-D logic could benefit from paying explicit attention to the fact that both service exchange and value co-creation are influenced by social forces. The aim of this study is to expand understanding of service exchange and value co-creation by complementing these central aspects of S-D logic with key concepts from social construction theories (social structures, social systems, roles, positions, interactions, and reproduction of social structures). The study develops and describes a new framework for understanding how the concepts of service exchange and value co-creation are affected by recognizing that they are embedded in social systems. The study contends that value should be understood as value-in-social-context and that value is a social construction. Value co-creation is shaped by social forces, is reproduced in social structures, and can be asymmetric for the actors involved. Service exchanges are dynamic, and actors learn and change their roles within dynamic service systems

Parameterization of a coarse-grained model of cholesterol with point-dipole electrostatics

© 2018, Springer Nature Switzerland AG. We present a new coarse-grained (CG) model of cholesterol (CHOL) for the electrostatic-based ELBA force field. A distinguishing feature of our CHOL model is that the electrostatics is modeled by an explicit point dipole which interacts through an ideal vacuum permittivity. The CHOL model parameters were optimized in a systematic fashion, reproducing the electrostatic and nonpolar partitioning free energies of CHOL in lipid/water mixtures predicted by full-detailed atomistic molecular dynamics simulations. The CHOL model has been validated by comparison to structural, dynamic and thermodynamic properties with experimental and atomistic simulation reference data. The simulation of binary DPPC/cholesterol mixtures covering the relevant biological content of CHOL in mammalian membranes is shown to correctly predict the main lipid behavior as observed experimentally