scholarly journals Mathematical modelling of oxygen concentration in bovine and murine cumulus–oocyte complexes

Reproduction ◽  
2006 ◽  
Vol 131 (6) ◽  
pp. 999-1006 ◽  
Author(s):  
A R Clark ◽  
Y M Stokes ◽  
M Lane ◽  
J G Thompson
Keyword(s):  
Mathematical Model ◽  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Consumption Rate ◽  
Cumulus Cells ◽  
Common Boundary ◽  
Nonlinear Variation ◽  
Cumulus Oocyte Complex ◽  
Atp Generation ◽  
Metabolic Data

Immature oocytes benefit from nutrient modification of the follicular environment by the surrounding cumulus mass. However, the oxygen concentration that the oocyte may be exposed to could be lower than the antral follicular concentration due to the metabolism of surrounding cumulus cells. Using metabolic data previously determined, we have developed a mathematical model of O2diffusion across the bovine and murine cumulus–oocyte complex. From this we have determined that across a physiological range of external pO2, less than 0.25% and 0.5% O2is removed by cumulus cells within the bovine and murine cumulus–oocyte complex respectively. Our model differs from others as it: incorporates a term that allows for nonlinear variation of the oxygen consumption rate with oxygen concentration; considers two regions (oocyte and cumulus) sharing a common boundary, both of which consume oxygen at different non linear rates. Cumulus cells therefore remove little O2, thus sparing this essential gas for the oocyte, which is dependent on ATP generation via oxidative phosphorylation.

scholarly journals Follicle Structure Influences the Availability of Oxygen to the Oocyte in Antral Follicles

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
A. R. Clark ◽  
Y. M. Stokes
Keyword(s):  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Oxygen Transport ◽  
Follicular Fluid ◽  
Antral Follicle ◽  
Antral Follicles ◽  
Cumulus Oocyte Complex ◽  
The Mean ◽  
Size And Structure

The ability of an oocyte to successfully mature is highly dependent on intrafollicular conditions, including the size and structure of the follicle. Here we present a mathematical model of oxygen transport in the antral follicle. We relate mean oxygen concentration in follicular fluid of bovine follicles to the concentration in the immediate vicinity of the cumulus-oocyte complex (COC). The model predicts that the oxygen levels within the antral follicle are dependent on the size and structure of the follicle and that the mean level of dissolved oxygen in follicular fluid does not necessarily correspond to that reaching the COC.

scholarly journals Oxygen consumption of Litopenaeus vannamei juveniles in heterotrophic medium with zero water exchange

2009 ◽  
Vol 44 (5) ◽  
pp. 534-538 ◽  
Author(s):  
Luis Vinatea ◽  
Alfredo Olivera Gálvez ◽  
Jesús Venero ◽  
John Leffler ◽  
Craig Browdy
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Litopenaeus Vannamei ◽  
Water Exchange ◽  
Consumption Rate ◽  
Light Conditions ◽  
Dissolved Oxygen Concentration ◽  
Dark Conditions ◽  
Over Time

This work aimed at determining the dissolved oxygen consumption rate of Litopenaeus vannamei juveniles maintained in a microbial biofloc raceway system at high density with no aeration. Three 4 L bottles were filled for each treatment, sealed hermetically, and placed in an enclosed greenhouse raceway system. Four shrimp (13.2±1.42 g) were assigned to two sets of the bottles, which underwent the following treatments: light conditions with no shrimp; dark conditions with no shrimp; light conditions with shrimp; and dark conditions with shrimp. Dissolved oxygen content was measured every 10 min for 30 min. A quadratic behavior was observed in dissolved oxygen concentration over time. Significant differences for oxigen consumption were observed only at 10 and 20 min between shrimp maintained in the dark and those under light conditions. At 10 min, a higher value was observed in shrimp maintained under light, and at 20 min, in the dark. Significant differences between 10 and 20 min and between 10 and 30 min were observed when oxygen consumption was analyzed over time in the presence of light. Under dark conditions there were significant differences only between 20 and 30 min. Lethal oxygen concentration (0.65 mg L-1) would be reached in less than one hour either under light or dark conditions with no aeration.

scholarly journals Oxygen Consumption by Phalaenopsis Plantlets and Chrysanthemum Cuttings as a Function of Temperature and Time: Model Structure Validation

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 237
Author(s):  
Lieven Van de Vondel ◽  
Annelies Christiaens ◽  
An Vermeulen ◽  
Marie-Christine Van Labeke ◽  
Frank Devlieghere ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Plant Species ◽  
Respiration Rate ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Storage Temperature ◽  
Modified Atmosphere Packaging ◽  
Modified Atmosphere ◽  
Model Structure

Phalaenopsis spp. and Chrysanthemum are ornamentals with an important economic value. Currently, quality loss during storage and transport of plantlets and cuttings is a limiting factor for spreading the workload, broadening the export range, and the use of slower but more environmentally friendly transport. In the agro-food sector, equilibrium modified atmosphere packaging has enhanced the shelf-life of minimally processed produce. The required properties for an equilibrium modified atmosphere packaging system can be estimated from the respiration rate of the packaged commodity under specified atmospheric composition and storage temperature. In this work, a model structure is validated to estimate the respiration rate as a function of oxygen concentration and temperature for Phalaenopsis and Chrysanthemum. The oxygen concentration as a function of time was monitored in a closed system for different storage temperatures. The models show a good fit to the data. The model coefficients were dependent on the plant species and characteristics. The resulting formulae can be used to estimate the oxygen consumption rate of the produce under a range of oxygen concentrations and a temperature range from 15 °C to 32 °C for Phalaenopsis and from 2 °C to 14 °C for Chrysanthemum. The oxygen concentrations for which the formulae are valid depend on the storage temperature and plant species. The models can be used to estimate a dynamic oxygen consumption rate profile during storage and transport.

The relationships between ambient oxygen concentration, temperature, body weight, and oxygen consumption for Mysis relicta (Malacostraca: Mysidacea)

1980 ◽  
Vol 58 (6) ◽  
pp. 1032-1036 ◽  
Author(s):  
I. M. Sandeman ◽  
D. C. Lasenby
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Mysis Relicta ◽  
Ambient Oxygen ◽  
Kootenay Lake ◽  
Oxygen Concentrations

The relationships between ambient oxygen concentration, temperature, body weight, and oxygen consumption for Mysis relicta in Kootenay Lake, B.C. are examined. Mysis oxygen consumption rate declined with both decreasing temperatures and ambient oxygen concentrations.

Benthic Oxygen dynamics: Influence of pore water advection and microphytobenthos in a permeable sediment

2021 ◽  
Author(s):  
Werna Werna ◽  
Stefan Forster
Keyword(s):  
Oxygen Consumption ◽  
Penetration Depth ◽  
Oxygen Concentration ◽  
Pore Water ◽  
Consumption Rate ◽  
Flow Simulation ◽  
Laboratory Simulation ◽  
Advective Transport ◽  
Permeable Sediment ◽  
Oxygen Dynamics

<p>The benthic oxygen consumption rate (OCR) has been widely used to measure the total benthic organic carbon degradation rate, while the oxygen distribution provides the general biogeochemistry state of marine sediments. In shallow coastal environments the light driven photosynthesis by benthic microalgae, resulting in large diurnal oscillations of oxygen concentration, further affects the oxygenation of the sediment. Yet, for permeable sediments, studies incorporating pore water advection driven by physical forces into oxygen consumption and distribution measurements are  still limited. Here we examine the combined effect of benthic oxygen production and advective oxygen transport on oxygen dynamics and consumption rate in a microphytobenthos-dominated sediment (permeability <em>k </em>=2 x 10<sup>-11</sup> to 5 x 10<sup>-11</sup> m<sup>2</sup>) in a laboratory simulation with stirred benthic chambers at 40 rpm. Under alternating light (50 μE m<sup>−2</sup> s<sup>-1</sup>) and flow regimes, oxygen concentration, penetration depth and consumption rates were monitored by means of micro-profiling and planar optode measurements. In all cases, we found that oxygen penetration depth increased up to a factor of 2 with pore water flow simulation. On the other hand, advective transport was found to reduce maximum oxygen concentration in the sediment by up to 30 %.  The OCR were up to 2-times higher with only light (28 ± 3.5 µM/min) compared to combined light and flow simulation, however the total oxygen uptake was generally uniform in all chambers (41.83 ± 5.9 mmol/m<sup>2 </sup>d<sup>-1</sup>), suggesting the local redistribution of oxygen with flow without marked overall changes in O<sub>2</sub> consumption. Our result emphasized the importance of advective transport controlling benthic oxygenation in photic permeable sediment.</p>

scholarly journals Measuring and Modeling Oxygen Transport and Consumption in 3D Hydrogels Containing Chondrocytes and Stem Cells of Different Tissue Origins

2021 ◽  
Vol 9 ◽  
Author(s):  
Simon F. Carroll ◽  
Conor T. Buckley ◽  
Daniel J. Kelly
Keyword(s):  
Stem Cells ◽  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Cartilage Matrix ◽  
Matrix Synthesis ◽  
Cellular Oxygen ◽  
Local Oxygen ◽  
Consumption Profile

Understanding how the local cellular environment influences cell metabolism, phenotype and matrix synthesis is crucial to engineering functional tissue grafts of a clinically relevant scale. The objective of this study was to investigate how the local oxygen environment within engineered cartilaginous tissues is influenced by factors such as cell source, environmental oxygen tension and the cell seeding density. Furthermore, the subsequent impact of such factors on both the cellular oxygen consumption rate and cartilage matrix synthesis were also examined. Bone marrow derived stem cells (BMSCs), infrapatellar fat pad derived stem cells (FPSCs) and chondrocytes (CCs) were seeded into agarose hydrogels and stimulated with transforming growth factor-β3 (TGF- β3). The local oxygen concentration was measured within the center of the constructs, and numerical modeling was employed to predict oxygen gradients and the average oxygen consumption rate within the engineered tissues. The cellular oxygen consumption rate of hydrogel encapsulated CCs remained relatively unchanged with time in culture. In contrast, stem cells were found to possess a relatively high initial oxygen consumption rate, but adopted a less oxidative, more chondrocyte-like oxygen consumption profile following chondrogenic differentiation, resulting in net increases in engineered tissue oxygenation. Furthermore, a greater reduction in oxygen uptake was observed when the oxygen concentration of the external cell culture environment was reduced. In general, cartilage matrix deposition was found to be maximal in regions of low oxygen, but collagen synthesis was inhibited in very low (less than 2%) oxygen regions. These findings suggest that promoting an oxygen consumption profile similar to that of chondrocytes might be considered a key determinant to the success of stem cell-based cartilage tissue engineering strategies.

Microbial efficiency in a meromictic reservoir

2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Release Rate ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Metabolic Efficiency ◽  
Sulphur Compounds ◽  
Carbon Dioxide Release ◽  
Microbial Efficiency ◽  
Ion Contents

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.

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