Homeostatic Value Research Articles

Identification of spring barley genetic sources of increased and stable 1000 kernel weight performance (Hordeum vulgare L.)

The trials were conducted in 2018–2020 at the V.M. Remeslo Myronivka Institute of Wheat of NAAS. The aim of the research was to identify new spring barley genetic sources with combination of increased and stable 1000 kernel weight performance for creation initial breeding material under ecological conditions of the central part of Ukrainian Forest-steppe. There were studied 96 spring barley collection accessions originated in different ecological conditions. To identify peculiarities among genotypes within different subspecies (two-rowed and sixrowed), groups of varieties (covered and naked), as well as among two-rowed covered accessions of different ecological origin the genotypes under study were divided into six groups. Within four groups of accessions there were selected genotypes combining the maximum 1000 kernel weight performance and high homeostatic (Hom) and selection value (Sc) indexes. The other two groups of accessions were characterized with the fact that genotypes with high1000 kernel weight through three years did not have high Hom and Sc indexes due to higher variability. The analysis of variance of the AMMI model revealed almost the equal contribution to the total variance for growing season conditions (34.02%), genotype (34.67%) and their interaction (31.32%). The identified features indicate both the significant genetic diversity presented in this panel of spring barley accessions and the significant influence of weather conditions on the formation of 1000 kernel weight, as well as the different reaction of genotypes on the conditions of individual years of the research. When using statistical parameters and visualizations of the GGE biplot, new spring barley genetic sources with the optimal combination of increased and stable the trait performance were identified. In particular, to improve 1000 kernel weight the accessions Sviatovit (UKR), Dar Nosivshchyny (UKR), Smaragd (UKR), Sunshine (DEU), Lilly (DEU), and Vladlen (KGZ) are recommended to use as parental components for two-rowed covered barley varieties, the accession NSGJ-1 (SRB) is for naked barley varieties, and Yerong (AUS) is for six-rowed barley varieties.

Exploring homeostatic value of space to prevent maladaptive behaviours of people living with dementia: a narrative study

ABSTRACT The aim of this paper is to raise awareness and provide a frame of analysis to prevent environmental triggers of maladaptive behaviours of people living with dementia (PwD), for which transition to an institutional setting can cause great distress. Institutional settings are one of the main causes of maladaptive beaviours of PwD. We provide a narrative description of an environmental analogue, using thick description methodology of a design fiction situation – a long-haul flight – to illustrate similar behavioural processes taking place in a setting for all comers to understand psycho-environmental mechanisms that lead PwD to distress. Phenomenology of homeostatic value of space is discussed. We identify four main factors to apprehend homeostatic value of space: (1) Survival properties of the environment; (2) Person-Environment fit; (3) Environmental control and (4) Sensoristasis. This paper discusses environmental mechanisms of dwelling facilities for PwD that can positively influence their psychological and behavioural well-being.

Chemo-mechanical model of a cell as a stochastic active gel

While it is commonly observed that the shape dynamics of mammalian cells can undergo large random fluctuations, theoretical models aiming at capturing cell mechanics often focus on the deterministic part of the motion. In this paper, we present a framework that couples an active gel model of the cell mechanical scaffold with the complex cell metabolic system stochastically delivering the chemical energy needed to sustain an active stress in the scaffold. Our closure assumption setting the magnitude of the fluctuations is that the chemo-mechanical free energy of the cell is controlled at a target homeostatic value. Our model rationalizes the experimental observation that the cell shape fluctuations depend on the mechanical environment that constraints the cell. We apply our framework to the simple case of a cell migrating on a one dimensional track to successfully capture the different regimes of the cell mean square displacement along the track as well as the magnitude of the long time scale effective diffusive motion of the cell.

Long-Time Phase Correlations Reveal Regulation of Beating Cardiomyocytes.

Spontaneous contractions of cardiomyocytes are driven by calcium oscillations due to the activity of ionic calcium channels and pumps. The beating phase is related to the time-dependent deviation of the oscillations from their average frequency, due to noise and the resulting cellular response. Here, we demonstrate experimentally that, in addition to the short-time (1-2Hz), beat-to-beat variability, there are long-time correlations (tens of minutes) in the beating phase dynamics of isolated cardiomyocytes. Our theoretical model relates these long-time correlations to cellular regulation that restores the frequency to its average, homeostatic value in response to stochastic perturbations.

No evidence of homeostatic regulation of leaf temperature in Eucalyptus parramattensis trees: integration of CO2 flux and oxygen isotope methodologies.

Thermoregulation of leaf temperature (Tleaf ) may foster metabolic homeostasis in plants, but the degree to which Tleaf is moderated, and under what environmental contexts, is a topic of debate. Isotopic studies inferred the temperature of photosynthetic carbon assimilation to be a constant value ofc.20°C; by contrast, leaf biophysical theory suggests a strong dependence of Tleaf on environmental drivers. Can this apparent disparity be reconciled? We continuously measured Tleaf and whole-crown net CO2 uptake for Eucalyptus parramattensis trees growing in field conditions in whole-tree chambers under ambient and+3°C warming conditions, and calculated assimilation-weighted leaf temperature (TL-AW ) across 265d, varying in air temperature (Tair ) from -1 to 45°C. We compared these data to TL-AW derived from wood cellulose δ18 O. Tleaf exhibited substantial variation driven by Tair , light intensity, and vapor pressure deficit, and Tleaf was strongly linearly correlated with Tair with a slope ofc.1.0. TL-AW values calculated from cellulose δ18 O vs crown fluxes were remarkably consistent; both varied seasonally and in response to the warming treatment, tracking variation in Tair . The leaves studied here were nearly poikilothermic, with no evidence of thermoregulation of Tleaf towards a homeostatic value. Importantly, this work supports the use of cellulose δ18 O to infer TL-AW , but does not support the concept of strong homeothermic regulation of Tleaf.

A compartment size-dependent selective threshold limits mutation accumulation in hierarchical tissues

Cancer is a genetic disease fueled by somatic evolution. Hierarchical tissue organization can slow somatic evolution by two qualitatively different mechanisms: by cell differentiation along the hierarchy "washing out" harmful mutations and by limiting the number of cell divisions required to maintain a tissue. Here we explore the effects of compartment size on somatic evolution in hierarchical tissues by considering cell number regulation that acts on cell division rates such that the number of cells in the tissue has the tendency to return to its desired homeostatic value. Introducing mutants with a proliferative advantage, we demonstrate the existence of a third fundamental mechanism by which hierarchically organized tissues are able to slow down somatic evolution. We show that tissue size regulation leads to the emergence of a threshold proliferative advantage, below which mutants cannot persist. We find that the most significant determinant of the threshold selective advantage is compartment size, with the threshold being higher the smaller the compartment. Our results demonstrate that, in sufficiently small compartments, even mutations that confer substantial proliferative advantage cannot persist, but are expelled from the tissue by differentiation along the hierarchy. The resulting selective barrier can significantly slow down somatic evolution and reduce the risk of cancer by limiting the accumulation of mutations that increase the proliferation of cells.

The Ontogenetic Intelligence of Nature

The ontogenetic intelligence of nature defines the basic laws of evolution. It is a set of what can be called natural laws which rule the evolution of living beings. It was researched in order to find an approach to forecast and influence evolution. Ontogenetic intelligence is defined by two principles of nature:1) The action principle that sustains growth and evolution. It is driven by expansion. 2) The energy conservation principle, which sustains survival and avoids involution. It is driven by contraction. In the field of human behavior, the action principle gives birth to the verbal function, which makes the fulfillment of purposes possible. The entropy produced by action produces changes in the goal of purposes. To avoid changes and sustain the purpose, the energy conservation principle produces a homeostasis. The homeostatic value complements the purpose and ensures that action occurs within the established limits. But the consequence of this interaction is never deterministic. The change produced by the interaction of the living being with the environment produces evolution or involution. In nature, both principles sustain the evolution of living beings. Their effects can be observed in bacteria, viruses, cells, and other living beings.At a more operational level, besides the expansion and contraction principles, there are functions that provide security and functions that provide freedom to living beings. These functions are implicit in the upper level functions (expansion - contraction). Ontogenetic intelligence provides the basic rules to adapt to an environment. It sustains the living being’s unstable equilibrium. When, for any reasons, the ontogenetic intelligence is inhibited, the living being loses its equilibrium and its survival is endangered. These principles are active in individual beings and in the live environment they are part of.

The Unicist Logic and its Mathematics as a Complex Adaptive System

Every entity is ruled by a concept that defines its purpose, its action and the way it controls its operation so as to prevent the purpose from being altered.When dealing with living beings, concepts are intrinsic and define both the nature and evolution of that being. In the case of the elements used by the living creature, we call them extrinsic concepts which acquire sense by the being’s own intrinsic concepts.The difference between an intrinsic and an extrinsic concept lies in the ability to know and become aware of it. What is extrinsic to one may result intrinsic to another. While the logical structures of intrinsic concepts “are”, the ones of extrinsic concepts “are believed”.This is why extrinsic concepts are defined as credibility zones determined by the intrinsic functional needs of the living beings.A purpose, a procedure and an action guide describe every concept. The purpose, known as central value, sustains the natural functionality of the “object” under analysis.The procedure, known as antithetic value, aims on the one hand, at acting in relation to the environment and on the other hand, at modifying the purpose tending to a higher functionality level.The action guide, known as homeostatic value, aims at supporting the central value purpose, tending to minimize the energy consumption so as to avoid the modification of the concept functionality.The unicist logic ends up describing a unified field. If we describe the unified field for a living being in an abstract way we may say that the purpose is given by its vital functionality, the procedure by the action developing value and entropy, and the action guide by the conservation function.The unicist logic defines the logical relations among the elements above setting forth the laws that rule a system.

A unified theoretical structure for modeling interstitial growth and muscle activation in soft tissues

The objective of this paper is to develop a new unified theoretical structure for modeling interstitial growth and muscle activation in soft tissues. The model assumes a simple continuum with a single velocity field. In contrast with many other formulations, evolution equations are proposed directly for a scalar measure of elastic dilatation and a tensorial measure of elastic distortional deformation. The evolution equation for elastic dilatation includes a rate of mass supply or removal that controls volumetric growth and causes the elastic dilatation to evolve towards its homeostatic value. Similarly, the evolution equation for elastic distortional deformation includes a rate of growth that causes the elastic distortional deformation tensor to evolve towards its homeostatic value. Specific forms for these inelastic rates of growth and the associated homeostatic values have been considered for volumetric, area and fiber growth processes, as well as for muscle activation. Since the rate of growth appears in the evolution equations and not a growth tensor it is possible to model the combined effects of multiple growth and muscle activation mechanisms simultaneously. Also, robust, strongly objective, numerical algorithms have been developed to integrate the evolution equations.

Strain energy in the femoral neck during exercise

Physical activity is recommended to mitigate the incidence of hip osteoporotic fractures by improving femoral neck strength. However, results from clinical studies are highly variable and unclear about the effects of physical activity on femoral neck strength. We ranked physical activities recommended for promoting bone health based on calculations of strain energy in the femoral neck. According to adaptive bone-remodeling theory, bone formation occurs when the strain energy (S) exceeds its homeostatic value by 75%. The potential effectiveness of activity type was assessed by normalizing strain energy by the applied external load. Tensile strain provided an indication of bone fracture. External force and joint motion data for 15 low- and high-load weight-bearing and resistance-based activities were used. High-load activities included weight-bearing activities generating a ground force above 1 body-weight and maximal resistance exercises about the hip and the knee. Calculations of femoral loads were based on musculoskeletal and finite-element models. Eight of the fifteen activities were likely to trigger bone formation, with isokinetic hip extension (ΔS=722%), one-legged long jump (ΔS=572%), and isokinetic knee flexion (ΔS=418%) inducing the highest strain energy increase. Knee flexion induced approximately ten times the normalized strain energy induced by hip adduction. Strain and strain energy were strongly correlated with the hip-joint reaction force (R2=0.90–0.99; p<0.05) for all activities, though the peak load location was activity-dependent. None of the exercises was likely to cause fracture. Femoral neck mechanics is activity-dependent and maximum isokinetic hip-extension and knee-flexion exercises are possible alternative solutions to impact activities for improving femoral neck strength.

A Facial Color Transition Model to Express Character Emotion

High quality graphics for game characters has been continuously improving, spurred by the astonishing growth of the graphics technology. Despite such improvements, the current expression of emotion has limited representation because it is difficult to implement it in real-time and a large amount of storage is required to store sprites for various feelings. Since users are demanding a more expressive character to reflect emotion, such restrictions can prevent the users from getting fully indulged in a game. To address this, we propose a facial color transition model, which is a combination of the emotional colors based on the theory of emotion, the emotion-color association, and the emotional transition with personal traits. The model is implemented by using the homeostatic value, the accumulated stimulus, and nonlinear transition functions, which support diverse changes according to the character’s personality with low computational cost. The reflection of the game character’s emotion on its facial color will not only make users immerse into the game, but also enrich their fantasy in games.

Analytical and Biological Variation in Measures of Anemia and Iron Status in Patients Treated With Maintenance Hemodialysis

To make informed decisions in dosing erythropoiesis-stimulating agents and intravenous iron therapy, clinicians must determine whether differences between current and previous test results for anemia and iron status markers reflect expected variation, a significant change, or an actual trend. Prospective observational cohort study. 30 patients undergoing thrice-weekly in-center hemodialysis. Within-patient biological variations in hemoglobin (Hb) level, hematocrit (Hct), reticulocyte Hb content, transferrin saturation (TSAT), and ferritin level were determined over 12 consecutive treatment days. We separately measured same-sample analytical variation and within-patient biological variation (coefficient of variation), then calculated the number of sampling days needed to determine the true or homeostatic value for each analyte with 95% probability. We also evaluated whether results differed among the first, second, and third dialysis days of the week. Biological variation differed by analyte. Hb level (4.0%), Hct (4.0%), and reticulocyte Hb content (4.8%) showed much lower variation than TSAT (38.2%) or ferritin level (15.1%). Analytical variation ranged from 2.0%-6.9% for all analytes. We found that one sample day would be sufficient to establish the true mean Hb level or Hct within a level of closeness+/-20% and 95% probability. For the same levels of closeness and probability, one sample day would be needed for reticulocyte Hb content, 15 for TSAT, and 3 for ferritin level. No pairwise comparison for any of the 5 analytes yielded a significant difference between results obtained on the first, second, or third dialysis day of the week. These findings may not apply to other patient populations. Low biological variation renders Hb level, Hct, and reticulocyte Hb content, but not TSAT and ferritin level, suitable for trend analysis using results from 2 successive samples. TSAT and ferritin test results, unlike reticulocyte Hb content, have limited value in evaluating changes in iron status within individual hemodialysis patients.

Nonuniformity of axial and circumferential remodeling of large coronary veins in response to ligation

The pressure-induced remodeling of coronary veins is important in coronary venous retroperfusion. Our hypothesis is that the response of the large coronary veins to pressure overload will depend on the degree of myocardial support. Eleven normal Yorkshire swine from either sex, weighing 31-39 kg, were studied. Five pigs underwent ligation of the left anterior descending (LAD) vein, and six served as sham-operated controls. The ligation of the coronary vein caused an increase in pressure intermediate to arterial and venous values. After 2 wk of ligation, the animals were euthanized and the coronary vessels were perfusion-fixed with glutaraldehyde. The LAD vein was sectioned, and detailed morphometric measurements were made along its length from the point of ligation near the base down to the apex of the heart. The structural remodeling of the vein was circumferentially nonuniform because the vein is partially embedded in the myocardium; it was also axially nonuniform because it is tethered to the myocardium to different degrees along its axial length. The wall area was significantly larger in the experimental group, whereas luminal area in the proximal LAD vein was significantly smaller in the same group compared with sham-operated controls. The wall thickness-to-radius ratio was also significantly larger in the experimental group in proportion to the increase in pressure. The major conclusion of this study is that the response of the vein depends on the local wall stress, which is, in part, determined by the surrounding tissue. Furthermore, the geometric remodeling of the coronary vein restores the circumferential stress to the homeostatic value.

A constrained mixture model for arterial adaptations to a sustained step change in blood flow

A sustained change in blood flow results in an arterial adaptation that can be thought to consist of two general steps: an immediate vasoactive response that seeks to return the wall shear stress to its homeostatic value, and a long-term growth and remodeling process that seeks to restore the intramural stresses and, if needed, the wall shear stress toward their homeostatic values. Few papers present mathematical models of arterial growth and remodeling in general, and fewer yet address flow-induced changes. Of these, most prior models build upon the concept of "kinematic growth" proposed by Skalak in the early 1980s (Skalak R (1981) In: Proceedings of the IUTAM Symposium on finite elasticity. Martinus Nijhoff, The Hague, pp 347-355). Such approaches address important consequences of growth and remodeling, but not the fundamental means by which such changes occur. In this paper, therefore, we present a new approach for mathematically modeling arterial adaptations and, in particular, flow-induced alterations. The model is motivated by observations reported in the literature and is based on a locally homogenized, constrained mixture theory. Specifically, we develop a 3-D constitutive relation for stress in terms of the responses of the three primary load-bearing constituents and their time-varying mass fractions, with the latter accounting for the kinetics of the turnover of cells and extracellular matrix in changing, stressed configurations. Of particular importance is the concept that the natural configurations of the individual constituents can evolve separately and that this leads to changes in the overall material properties and empirically inferred residual stress field of the vessel. Potential applications are discussed, but there is a pressing need for new, theoretically motivated data to allow the prescription of specific functional forms of the requisite constitutive relations and the values of the associated material parameters.

A potential role of smooth muscle tone in early hypertension: a theoretical study

A conspicuous long-term consequence of hypertension is a thickening of the arterial wall, which many suggest returns the circumferential wall stress toward its normal value. This thickening results from an increase in smooth muscle and extracellular matrix, with the associated growth and remodeling processes depending on a host of regulatory signals that likely include the altered mechanical environment. Although the precise mechanotransduction pathways remain unknown, we propose that vasoconstriction may be an early response of the arterial wall to a step-change in pressure. In particular, computations suggest that such a response can decrease the magnitude and transmural gradients of the pressure-induced wall stresses and return the mean wall shear stress toward its homeostatic value. Such an initial ‘compensatory vasoconstriction’ could also help set into motion subsequent growth and remodeling responses due to growth regulatory characteristics of the vasoactive molecules (e.g., nitric oxide, endothelin-1, angiotensin-II). Although the consequences of growth and remodeling have been the focus of prior biomechanical and histological studies, early responses dictate subsequent developments and therefore deserve increased attention in vascular biomechanics and mechanobiology.

Function of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system in models of acute stress in domestic farm animals2

In response to stressors, the central nervous system of livestock (and other mammalian species) evokes physiological responses that ultimately result in activation of the hypothalamo-pituitary-adrenocortical (HPA) axis and the sympatho-adrenal axis. The responses of these major systems are presumed to have adaptive and homeostatic value during periods of stress. The major hormone regulating the synthesis and secretion of adrenal glucocorticoids is ACTH. In sheep, cattle, and pigs, both corticotropin-releasing hormone (CRH) and vasopressin (VP) participate in the regulation of secretion of ACTH, and the two peptides seem to interact to enhance that secretion. In cattle and pigs, CRH is the more potent peptide, whereas VP is the more potent in sheep. In addition to its better-known role in regulating pituitary function, CRH also may participate as a neurotransmitter acting centrally to enhance sympathetic activation of the adrenal medulla. Many experimental models of stress have been evaluated that reliably activate the HPA axis and the sympatho-adrenal medullary axis, and some of these model systems also reduce functions of cells of the immune system. Recent data support an important role of stressor-activation of the sympathetics rather than increased glucocorticoids per se in modulating some measures of immune function in response to stress. Thus, current dogma of glucocorticoids as the primary mediator of stressor-associated alteration in immune function of domestic livestock may require reevaluation.

Advocation of insulin reaction test as the screening for hypoglycemia.

A newly invented insulin sensitivity method was tested in 11 hypoglycemic cases and 80 cases of various other diseases, and recovering ability from hypoglycemia as well as the homeostatic level of blood sugar was determined. In hypoglycemic cases, all of them indicated negative recovering ability and homeostatic values were lower than 63 mg.%. In various other conditions, no case was found which showed both negative recovering ability and lower homeostatic value than 65 mg.%. Other various blood sugar curves were evaluated for the purpose of screening hypoglycemia and it was concluded that only insulin reaction test is recommendable. Author wishes to express his sincere gratitude to Dr. T. Saito, Assistant Professor of Tohoku University Medical School, for his encouragement and various suggestions.

Clinical trial of synthetic oxytocin.

Cancer is a genetic disease fueled by somatic evolution. Hierarchical tissue organization can slow somatic evolution by two qualitatively different mechanisms: by cell differentiation along the hierarchy “washing out” harmful mutations (Nowak et al. 2003, Werner et al. 2013) and by limiting the number of cell divisions required to maintain a tissue (Derényi and Szöllősi 2017). Here we explore the effects of compartment size on somatic evolution in hierarchical tissues by considering cell number regulation that acts on cell division rates such that the number of cells in the tissue has the tendency to return to its desired homeostatic value. Introducing mutants with a proliferative advantage we demonstrate the existence of a third fundamental mechanism by which hierarchically organized tissues are able to slow down somatic evolution. We show that tissue size regulation leads to the emergence of a threshold proliferative advantage, below which mutants cannot persist. We find that the most significant determinant of the threshold selective advantage is compartment size, with the threshold being higher the smaller the compartment. Our results demonstrate that in sufficiently small compartments even mutations that confer substantial proliferative advantage cannot persist, but are expelled from the tissue by differentiation along the hierarchy. The resulting selective barrier can significantly slow down somatic evolution and reduce the risk of cancer by limiting the accumulation of mutations that increase the proliferation of cells. <h3>Significance Statement</h3> Renewed tissues of multicellular organism accumulate mutations that lead to ageing and cancer. To mitigate these effects self-renewing tissues produce cells along differentiation hierarchies, which have been shown to suppress somatic evolution both by limiting the number of cell divisions, and thus reducing mutational load, and by differentiation “washing out” mutations. Our analytical results reveal the existence of a third mechanism: a compartment size dependent threshold in proliferative advantage, below which mutations cannot persist, but are rapidly expelled from the tissue by differentiation. In sufficiently small compartments the resulting selective barrier can greatly slow down somatic evolution and reduce the risk of cancer by preventing the accumulation of mutations even if even they confer substantial proliferative advantage.