THE ROLE OF PHYSICAL AND GEOMETRICAL FACTORS IN THE GROWTH OF LIVING ORGANISMS

2010 ◽  
Vol 05 (01) ◽  
pp. 43-58 ◽  
Author(s):  
YURI K. SHESTOPALOFF
Keyword(s):  
Experimental Data ◽  
Growth Potential ◽  
Physical Growth ◽  
Physical Work ◽  
Growth Equation ◽  
Mathematical Basis ◽  
Growth Ratio ◽  
Geometrical Form ◽  
Geometrical Factors ◽  
The Impact

The relationship between the organism's growth and its geometrical form was suggested by many ancient and modern thinkers. Many other factors influence growth and replication. All these numerous factors, such as biochemical, physical, work in cooperation. In this paper, we consider the impact of geometrical and physical characteristics of organisms, such as surface, volume and geometrical form, on organisms' growth and replication. The mathematical basis of our study is the growth equation, which describes growth from the physical perspective. First, we model the growth of cells by different shapes, and compare theoretical results to experimental data. We discover that the growth dependencies produced by the growth equation fit experimental data very accurately if we take into account two considerations. First, the cell, or a multicellular growing object, can switch into a replication phase before its physical growth potential is exhausted. Second, the inflow of substance through a unit of the membrane's surface increases during growth, because the cell's growing volume allows it to process more nutrients. Then, we consider overgrowth from the physical perspective, introduce the notion of a growth ratio as an important geometrical characteristic of the growth and overgrowth processes, and generalize our findings.

A MATHEMATICAL MODEL OF THE PHYSICAL GROWTH MECHANISM AND GEOMETRICAL CHARACTERIZATION OF GROWING FORMS

2011 ◽  
Vol 04 (01) ◽  
pp. 35-53 ◽  
Author(s):  
YURI K. SHESTOPALOFF
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Growth Mechanism ◽  
Growth Suppression ◽  
Physical Growth ◽  
Geometrical Parameters ◽  
Growth Equation ◽  
Software Application ◽  
Multicellular Organisms

The article introduces a mathematical model of the physical growth mechanism which is based on the relationships of the physical and geometrical parameters of the growing object, in particular its surface and volume. This growth mechanism works in cooperation with the biochemical and other growth factors. We use the growth equation, which mathematically describes this mechanism, and study its adequacy to real growth phenomena. The growth model very accurately fits experimental data on growth of Amoeba, Schizosaccharomyces pombe, E.coli. Study discovered a new growth suppression mechanism created by certain geometry of the growing object. This result was proved by experimental data. The existence of the growth suppression phenomenon confirms the real workings and universality of the growth mechanism and the adequacy of its mathematical description. The introduced equation is also applicable to the growth of multicellular organisms and tumors. Another important result is that the growth equation introduces mathematical characterization of geometrical forms that can biologically grow. The material is supported by software application, which is released to public domain.

scholarly journals GENERAL LAW OF GROWTH AND REPLICATION, GROWTH EQUATION AND ITS APPLICATIONS

2012 ◽  
Vol 07 (01n02) ◽  
pp. 71-120 ◽  
Author(s):  
YURI K. SHESTOPALOFF
Keyword(s):  
Biomass Production ◽  
Growth Curves ◽  
Growth Cycle ◽  
Physical Growth ◽  
Growth Equation ◽  
Wild Type ◽  
Growth Ratio ◽  
General Law ◽  
Living Organisms ◽  
Scientific Value

We present significantly advanced studies of the previously introduced physical growth mechanism and unite it with biochemical growth factors. Obtained results allowed formulation of the general growth law which governs growth and evolutional development of all living organisms, their organs and systems. It was discovered that the growth cycle is predefined by the distribution of nutritional resources between maintenance needs and biomass production. This distribution is quantitatively defined by the growth ratio parameter, which depends on the geometry of an organism, phase of growth and, indirectly, the organism's biochemical machinery. The amount of produced biomass, in turn, defines the composition of biochemical reactions. Changing amount of nutrients diverted to biomass production is what forces organisms to proceed through the whole growth and replication cycle. The growth law can be formulated as follows: the rate of growth is proportional to influx of nutrients and growth ratio. Considering specific biochemical components of different organisms, we find influxes of required nutrients and substitute them into the growth equation; then, we compute growth curves for amoeba, wild type fission yeast, and fission yeast's mutant. In all cases, predicted growth curves correspond very well to experimental data. Obtained results prove validity and fundamental scientific value of the discovery.

scholarly journals Weight Status and Visceral Adiposity Mediate the Relationship between Exclusive Breastfeeding Duration and Skin Carotenoids in Later Childhood

2021 ◽  
Author(s):  
Ruyu Liu ◽  
Caitlyn G Edwards ◽  
Corinne N Cannavale ◽  
Isabel R Flemming ◽  
Morgan R Chojnacki ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Exclusive Breastfeeding ◽  
Weight Status ◽  
Mediating Effect ◽  
Physical Growth ◽  
Breastfeeding Duration ◽  
Whole Body ◽  
Controlled Clinical Trial ◽  
The Impact ◽  
The Relationship

Abstract Background Breastfeeding is associated with healthier weight and nutrient status in early life. However, the impact of breastfeeding on carotenoid status beyond infancy, and the influence of adiposity, is unknown. Objective The aim of the study was to retrospectively investigate the relationship between breastfeeding and carotenoid status, and the mediating effect of weight status and adiposity on this relationship among school-aged children. Methods This was a secondary analysis of baseline data collected from a randomized-controlled clinical trial. (ClinicalTrials.gov Identifier: NCT03521349). 7–12-year-old (n = 81) children were recruited from East-Central Illinois. Dual-energy x-ray absorptiometry (DXA) was used to assess visceral adipose tissue (VAT) and whole-body adiposity (%Fat). Weight was obtained to calculated body mass index percentile (BMI %ile). Skin carotenoids were assessed via reflection spectroscopy. Macular carotenoids were assessed as macular pigment optical density (MPOD). Dietary, birth, and breastfeeding information was self-reported by parents. Results Skin carotenoids were inversely related to %Fat (P < 0.01), VAT (P < 0.01) and BMI %ile (P < 0.01). VAT and BMI %ile significantly mediated this relationship between exclusive breastfeeding duration and skin carotenoids, following adjustment for dietary carotenoids, energy intake, and mother education. Conclusions Weight status and adipose tissue distribution mediate the positive correlation between exclusive breastfeeding duration and skin carotenoids among children aged 7–12 years. The results indicate the need to support breastfeeding and healthy physical growth in childhood for optimal carotenoid status.

scholarly journals Age-Dependent Decline in Neuron Growth Potential and Mitochondria Functions in Cortical Neurons

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1625
Author(s):  
Theresa C. Sutherland ◽  
Arthur Sefiani ◽  
Darijana Horvat ◽  
Taylor E. Huntington ◽  
Yuanjiu Lei ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Traumatic Injury ◽  
Axon Growth ◽  
Neurite Growth ◽  
Growth Potential ◽  
Mitochondrial Functions ◽  
Cord Injury ◽  
Age Dependent ◽  
Mitochondria Functions ◽  
The Impact

The age of incidence of spinal cord injury (SCI) and the average age of people living with SCI is continuously increasing. However, SCI is extensively modeled in young adult animals, hampering translation of research to clinical applications. While there has been significant progress in manipulating axon growth after injury, the impact of aging is still unknown. Mitochondria are essential to successful neurite and axon growth, while aging is associated with a decline in mitochondrial functions. Using isolation and culture of adult cortical neurons, we analyzed mitochondrial changes in 2-, 6-, 12- and 18-month-old mice. We observed reduced neurite growth in older neurons. Older neurons also showed dysfunctional respiration, reduced membrane potential, and altered mitochondrial membrane transport proteins; however, mitochondrial DNA (mtDNA) abundance and cellular ATP were increased. Taken together, these data suggest that dysfunctional mitochondria in older neurons may be associated with the age-dependent reduction in neurite growth. Both normal aging and traumatic injury are associated with mitochondrial dysfunction, posing a challenge for an aging SCI population as the two elements can combine to worsen injury outcomes. The results of this study highlight this as an area of great interest in CNS trauma.

scholarly journals Research on the Economic Development Threshold Effect of the Employment Density of the Shanghai Consumer Goods Industry in the Context of New Manufacturing, Based on the Experience Comparison with International Metropolis

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 969
Author(s):  
Lei Shen ◽  
Xi Zhang ◽  
Hongda Liu ◽  
Pinbo Yao
Keyword(s):  
Economic Development ◽  
Population Density ◽  
Consumer Goods ◽  
Inflection Point ◽  
Growth Potential ◽  
Positive Trend ◽  
Employment Density ◽  
Consumer Goods Industry ◽  
The Impact ◽  
Development Threshold

With the rise of a new generation of technology and industrial changes, the service-oriented manufacturing industry has become the direction of future development. With the background of new manufacturing, this paper constructs an economic development threshold model of employment density of consumer goods industry based on data from Shanghai and Tokyo from 2007 to 2016, and empirically analyzes the impact of the employment density of the consumer goods industry on urban economic development under different population densities. At the same time, by comparing the experience of Tokyo, the development status and prospects of Shanghai’s consumer goods industry are explored. The study found that the threshold of Tokyo’s consumer goods industry is 0.608. When population density is lower than this threshold, the consumer goods industry continues to promote the economic development of Tokyo; however, when the population density is higher than this threshold, the consumer goods industry begins to inhibit the economic development of Tokyo. The Shanghai consumer goods industry threshold is 0.329. Under the threshold, most of the consumer goods industry contributions to the economy are negative, but above the threshold, they begin to show a positive trend. The inflection point of the effect curve of Tokyo’s consumer goods industry on economic development has appeared, but the inflection point of Shanghai’s consumer goods industry has not yet appeared. Compared with Tokyo, the economic vitality of Shanghai’s consumer goods industry has not yet been fully released. With the continued increase of population density in Shanghai, the growth potential of the consumer goods industry is huge, and it is expected to reshape the flourishing age of Shanghai’s light industry brand.

SOME CHARACTERISTICS OF THE COMPOUND MULTIPLICITY IN HIGH-ENERGY NUCLEUS–NUCLEUS INTERACTIONS

2011 ◽  
Vol 20 (08) ◽  
pp. 1735-1754 ◽  
Author(s):  
M. MOHERY ◽  
M. ARAFA
Keyword(s):  
Experimental Data ◽  
Impact Parameter ◽  
Mass Number ◽  
Multiplicity Distribution ◽  
High Energy ◽  
Projectile Nucleus ◽  
Target Mass ◽  
Compound Multiplicity ◽  
Multiplicity Distributions ◽  
The Impact

The present paper deals with the interactions of 22 Ne and 28 Si nuclei at (4.1–4.5)A GeV /c with emulsion. Some characteristics of the compound multiplicity nc given by the sum of the number of shower particles ns and grey particles ng have been investigated. The present experimental data are compared with the corresponding ones calculated according to modified cascade evaporation model (MCEM). The results reveal that the compound multiplicity distributions for these two reactions are consistent with the corresponding ones of MCEM data. It can also be seen that the peak of these distributions shifts towards a higher value of nc with increasing projectile mass. It may further be seen that the compound multiplicity distributions becomes broader with increasing target size and its width increases with the size of the projectile nucleus. In addition, it has been found that the MCEM can describe the compound multiplicity characteristics of the different projectile, target and the correlation between different emitted particles. The values of average compound multiplicity increase with increasing mass of the projectile. Furthermore, it is observed that while the value of 〈nc〉 depends on the mass number of the projectile Ap and the target mass number At, the value of the ratio 〈nc〉/D(nc) seems to be independent of Ap and At. The impact parameter is found to affect the shape of the compound multiplicity distribution. Finally, the dependence of the average compound multiplicity on the numbers of grey and black particles, and the sum of them, is obvious. The values of the slope have been found to be independent of the projectile nucleus.

The penetration and ricochet of ogive-nosed rigid projectiles obliquely impacting metallic targets

2021 ◽  
pp. 204141962110377
Author(s):  
Yaniv Vayig ◽  
Zvi Rosenberg
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Dynamic Pressure ◽  
Oblique Impacts ◽  
Simulation Results ◽  
The Impact ◽  
Penetration Depths ◽  
Resistance To Penetration ◽  
Good Agreement

A large number of 3D numerical simulations were performed in order to follow the trajectory changes of rigid CRH3 ogive-nosed projectiles, impacting semi-infinite metallic targets at various obliquities. These trajectory changes are shown to be related to the threshold ricochet angles of the projectile/target pairs. These threshold angles are the impact obliquities where the projectiles end up moving in a path parallel to the target’s face. They were found to depend on a non-dimensional entity which is equal to the ratio between the target’s resistance to penetration and the dynamic pressure exerted by the projectile upon impact. Good agreement was obtained by comparing simulation results for these trajectory changes with experimental data from several published works. In addition, numerically-based relations were derived for the penetration depths of these ogive-nosed projectiles at oblique impacts, which are shown to agree with the simulation results.

Early Physical Therapy Effects on the High-Risk Infant: A Randomized Controlled Trial

PEDIATRICS ◽  
1986 ◽  
Vol 78 (2) ◽  
pp. 216-224
Author(s):  
Martha C. Piper ◽  
V. Ildiko Kunos ◽  
Diana M. Willis ◽  
Barbara L. Mazer ◽  
Maria Ramsay ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Physical Therapy ◽  
High Risk ◽  
Motor Development ◽  
Controlled Trial ◽  
Physical Growth ◽  
Control Group ◽  
Randomized Controlled ◽  
Early Physical Therapy ◽  
The Impact

A prospective, randomized, controlled trial was conducted to assess the effects of early physical therapy on infants at risk for neurologic sequelae and to evaluate the impact of such early treatment on the prevention or minimization of future handicaps. A cohort of 134 infants who had received care in two Montreal inborn neonatal intensive care units was identified prospectively. Infants were stratified according to prognosis and birth weight and were randomly assigned to either an experimental or control group. Babies assigned to the experimental group received early physical therapy, whereas those allocated to the control group received conventional follow-up care. Outcome measures were administered by independent evaluators at 12 months and included measures of neurologic status, motor and overall development, and physical growth. No statistically significant differences on any of the measured outcomes at 12 months were found between the experimental and control groups. Infants weighing less than 750 g at birth, regardless of group assignment, consistently demonstrated significant delays in their growth and development when compared with their heavier peers. The early physical therapy program investigated in this study was not efficacious in altering the pattern of motor development in those high-risk infants participating in the trial.

Ozone Production With Plasma Discharge: Comparisons Between Activated Air and Activated Fuel/Air Mixture

2021 ◽  
Author(s):  
Ghazanfar Mehdi ◽  
Maria Grazia De Giorgi ◽  
Donato Fontanarosa ◽  
Sara Bonuso ◽  
Antonio Ficarella
Keyword(s):  
Experimental Data ◽  
Plasma Chemistry ◽  
Kinetic Scheme ◽  
Plasma Discharge ◽  
Chemical Kinetic ◽  
Ozone Production ◽  
Air Plasma ◽  
Flammability Limits ◽  
Combustion Enhancement ◽  
The Impact

Abstract This study focused on the comparative analysis about the production of ozone and active radicals in presence of nanopulsed plasma discharge on air and on fuel/air mixture to investigate its effect on combustion enhancement. This analysis is based on numerical modeling of air and methane/air plasma discharge with different repetition rates (100 Hz, 1000 Hz and 10000 Hz). To this purpose, a two-step approach has been proposed based on two different chemistry solvers: a 0-D plasma chemistry solver (ZDPlasKin toolbox) and a combustion chemistry solver (CHEMKIN software suite). Consequently, a comprehensive chemical kinetic scheme was generated including both plasma excitation reactions and gas phase reactions. Validation of air and methane/air mechanisms was performed with experimental data. Kinetic models of both air and methane/air provides good fitting with experimental data of O atom generation and decay process. ZDPlasKin results were introduced in CHEMKIN in order to analyze combustion enhancement. It was found that the concentrations of O3 and O atom in air are higher than the methane/air activation. However, during the air activation peak concentration of ozone was significantly increased with repetition rates and maximum was observed at 10000 Hz. Furthermore, ignition timings and flammability limits were also improved with air and methane/air activation but the impact of methane/air activation was comparatively higher.

Abstract P457: Systems Analysis To Understand The Impact Of The CDK Module On Cardiomyocyte Proliferation

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Bryana N Harris ◽  
Laura Woo ◽  
Jeffrey J Saucerman
Keyword(s):  
Experimental Data ◽  
Cell Cycle ◽  
Transcription Factor ◽  
Dna Synthesis ◽  
Current Knowledge ◽  
Cycle Phase ◽  
Cyclin D ◽  
Cardiomyocyte Proliferation ◽  
The Core ◽  
The Impact

Rationale: Heart failure is caused by the inability of adult mammalian hearts to overcome the loss of cardiomyocytes (CMs). This is due partly to the limited proliferative capacity of CMs, which exit the cell cycle and do not undergo cell division. Current knowledge in cardiac regeneration lacks an understanding of the molecular regulatory networks that determine whether CMs will progress through the cell cycle to proliferate. Our goal is to use computational modeling to understand the expression and activation levels of the core cell cycle network, specifically cyclins and cyclin-cyclin-dependent kinase (CDK) complexes. Methods: A model of core cell cycle dynamics was curated using previously published studies of CM proliferation regulators. This model incorporates those regulators known to stimulate G1/S and G2/M transitions through the core CDKs. The activity of each of the 22 network nodes (22 reactions) was predicted using a logic-based differential equation approach. The CDK model was then coupled with a minimal ODE model of cell cycle phase distributions and validated based on descriptions and experimental data from the literature. To prioritize key nodes for experimental validation, we performed a sensitivity analysis by stimulating individual knockdown for every node in the network, measuring the fractional activity of all nodes. Results: Our model confirmed that the knockdown of p21 and Rb protein and the overexpression of E2F transcription factor and cyclinD-cdk4 showed an increase in cells going through DNA synthesis and entering mitosis. A combined knockdown of p21 and p27 showed an increase of cells entering mitosis. Cyclin D-cdk4 and p21 overexpression showed a decrease and increase of Rb expression, respectively. Of the 14 model predictions, 12 agreed with experimental data in the literature. A comprehensive knockdown of the model nodes suggests that E2F (a key transcription factor driving DNA synthesis) is positively regulated by cyclin D while negatively regulated by GSK3B, SMAD3, and pRB. Conclusion: This model enables us to predict how cardiomyocytes respond to stimuli in the CDK network and identify potential therapeutic regulators that induce cardiomyocyte proliferation.

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