scholarly journals Dynamic product-precursor relationships underlie cuticular lipid accumulation on maize silks

2021 ◽  
Author(s):  
Keting Chen ◽  
Liza E. Alexander ◽  
Umnia Mahgoub ◽  
Yozo Okazaki ◽  
Yasuhiro Higashi ◽  
...  
Keyword(s):  
Chain Length ◽  
Lipid Accumulation ◽  
Complex Dynamics ◽  
Cuticular Hydrocarbon ◽  
Cuticular Lipid ◽  
Plant Genotype ◽  
Lipid Profiling ◽  
Spatio Temporal ◽  
Maize Silks ◽  
Precursor Chain

ABSTRACTThe hydrophobic cuticle is the first line of defense between aerial portions of a plant and the external environment. On maize silks, the cuticular cutin matrix is infused with cuticular lipids, consisting of a homologous series of very-long-chain fatty acids (VLCFAs), aldehydes, and hydrocarbons that serve as precursors, intermediates, and end-products of the elongation, reduction, and decarbonylation reactions of the hydrocarbon-producing pathway. To deconvolute the potentially confounding impacts of the silk microenvironment and silk development on the hydrocarbon-producing pathway, spatio-temporal cuticular lipid profiling was conducted on the agronomically important inbreds B73 and Mo17, and their reciprocal hybrids. Statistical interrogation via multivariate analyses of the metabolite abundances of the hydrocarbon-producing pathway demonstrate that the cellular VLCFA pool is positively correlated with the cuticular lipid metabolome, and this metabolome is primarily affected by the silk microenvironment and the plant genotype. Moreover, genotype has a major effect on the pathway, with increased cuticular hydrocarbon and concomitant reduction of cuticular VLCFA accumulation on B73 silks, suggesting that conversion of VLCFAs to hydrocarbons is more effective in B73 than Mo17. Statistical modeling of the ratios between cuticular hydrocarbons and cuticular VLCFAs reveals the complexity of the product-precursor ratio relationship, demonstrating a significant role of precursor chain length. Longer-chain VLCFAs are preferentially utilized as precursors for hydrocarbon biosynthesis. Collectively, these findings demonstrate maize silks as an effective and novel system for dissection of the complex dynamics of cuticular lipid accumulation in plants.One-sentence SummaryThe product-precursor ratios in the cuticular hydrocarbon-producing pathway are impacted by fatty acid precursor chain length, plant genotype and the spatio-temporal dynamic gradients of maize silks.

Lipid profiling of human diabetic myocardium reveals differences in triglyceride fatty acyl chain length and degree of saturation

2020 ◽  
Vol 320 ◽  
pp. 106-111
Author(s):  
Elias Björnson ◽  
Ylva Östlund ◽  
Marcus Ståhlman ◽  
Martin Adiels ◽  
Elmir Omerovic ◽  
...  
Keyword(s):  
Chain Length ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Degree Of Saturation ◽  
Fatty Acyl Chain ◽  
Lipid Profiling ◽  
Acyl Chain Length ◽  
Diabetic Myocardium

scholarly journals Sensitivity of a data-assimilation system for reconstructing three-dimensional cardiac electrical dynamics

2020 ◽  
Vol 378 (2173) ◽  
pp. 20190388 ◽  
Author(s):  
Matthew J. Hoffman ◽  
Elizabeth M. Cherry
Keyword(s):  
Data Assimilation ◽  
Temporal Dynamics ◽  
Complex Dynamics ◽  
Three Dimensional ◽  
Model Error ◽  
Model Parameters ◽  
Ensemble Spread ◽  
Spatio Temporal ◽  
System States ◽  
Parameter Values

Modelling of cardiac electrical behaviour has led to important mechanistic insights, but important challenges, including uncertainty in model formulations and parameter values, make it difficult to obtain quantitatively accurate results. An alternative approach is combining models with observations from experiments to produce a data-informed reconstruction of system states over time. Here, we extend our earlier data-assimilation studies using an ensemble Kalman filter to reconstruct a three-dimensional time series of states with complex spatio-temporal dynamics using only surface observations of voltage. We consider the effects of several algorithmic and model parameters on the accuracy of reconstructions of known scroll-wave truth states using synthetic observations. In particular, we study the algorithm’s sensitivity to parameters governing different parts of the process and its robustness to several model-error conditions. We find that the algorithm can achieve an acceptable level of error in many cases, with the weakest performance occurring for model-error cases and more extreme parameter regimes with more complex dynamics. Analysis of the poorest-performing cases indicates an initial decrease in error followed by an increase when the ensemble spread is reduced. Our results suggest avenues for further improvement through increasing ensemble spread by incorporating additive inflation or using a parameter or multi-model ensemble. This article is part of the theme issue ‘Uncertainty quantification in cardiac and cardiovascular modelling and simulation’.

Greenhouse gas dynamics in drained peatlands: CH4 and N2O fluxes from tree stems and soil

2021 ◽  
Author(s):  
Reti Ranniku ◽  
Thomas Schindler ◽  
Eliisa Lehtme ◽  
Ülo Mander ◽  
Katerina Machacova ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Complex Dynamics ◽  
Ghg Emissions ◽  
Research Station ◽  
Flux Data ◽  
Biological Variables ◽  
Birch Trees ◽  
Downy Birch ◽  
Spatio Temporal ◽  
Ch4 And N2o

<p>Peatland soils are considered the dominating source of nitrous oxide (N<sub>2</sub>O) and methane (CH<sub>4</sub>) to the atmosphere. However, there are high spatio-temporal uncertainties regarding the budgets of these greenhouse gases (GHG) from peatlands due to complex dynamics between the chemical, physical and biological variables occurring in the soil. GHG fluxes from peatland soils are relatively well studied, however, tree stems have received far less attention and are often overlooked in GHG models and assessments. It is necessary to study relationships between stem and soil fluxes, and their chemical, physical and biological drivers to understand the fluxes' origin.</p><p>Our ongoing project focuses on measuring GHGs from tree stems and soil in the Agali Birch Forest Research Station in Estonia, representing a drained peatland with Downy Birch (<em>Betula pubescens</em>) and Norway Spruce (<em>Picea abies</em>) trees. Twelve representative sub-sites were selected in the study area. One half consist of an adjacent set of a Downy Birch and a Norway Spruce tree with manual tree stem chambers, plus one automatic dynamic soil chamber. The remaining sub-sites are set pairs of birch trees and soil chambers. Six birch trees and all six spruce trees have stem chambers installed at 10, 80 and 170 cm above the ground to measure stem fluxes' vertical profile. Chambers on the six remaining birch trees were only installed at the lowest height. During the weekly ongoing sampling campaigns that started in October 2020, we use manual static gas extraction from rigid stem chambers to analyse hourly changes in chamber headspace concentrations of CH<sub>4</sub> and N<sub>2</sub>O. The gas samples are analysed in the laboratory within two weeks of collection using gas chromatography. Automated soil chambers collect CH<sub>4</sub> and N<sub>2</sub>O flux data every two hours per chamber, and a connected Picarro measuring unit analyses the gas samples in-situ.</p><p>When extrapolated, our results can help understand stem and soil GHG emissions on an ecosystem level and acknowledge the role of tree stems for local and regional GHG budgets. Within a larger research framework, these GHG flux data will be joined with detailed soil biogeochemistry and microbial dynamics to further improve process-based modelling of peatland GHG emissions. We plan to continue our measurements for one full year to understand the seasonal changes in CH<sub>4</sub> and N<sub>2</sub>O emissions patterns.</p>

scholarly journals Learning and discrimination of cuticular hydrocarbons in a social insect

2011 ◽  
Vol 8 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Ellen van Wilgenburg ◽  
Antoine Felden ◽  
Dong-Hwan Choe ◽  
Robert Sulc ◽  
Jun Luo ◽  
...  
Keyword(s):  
Chain Length ◽  
Social Insect ◽  
Species Recognition ◽  
Cuticular Hydrocarbon ◽  
Mate Recognition ◽  
Olfactory Conditioning ◽  
Argentine Ants ◽  
Nest Mate ◽  
Chemical Signalling ◽  
Branching Patterns

Social insect cuticular hydrocarbon (CHC) mixtures are among the most complex chemical cues known and are important in nest-mate, caste and species recognition. Despite our growing knowledge of the nature of these cues, we have very little insight into how social insects actually perceive and discriminate among these chemicals. In this study, we use the newly developed technique of differential olfactory conditioning to pure, custom-designed synthetic colony odours to analyse signal discrimination in Argentine ants, Linepithema humile . Our results show that tri-methyl alkanes are more easily learned than single-methyl or straight-chain alkanes. In addition, we reveal that Argentine ants can discriminate between hydrocarbons with different branching patterns and the same chain length, but not always between hydrocarbons with the same branching patterns but different chain length. Our data thus show that biochemical characteristics influence those compounds that ants can discriminate between, and which thus potentially play a role in chemical signalling and nest-mate recognition.

Effect of cobalt carboxylate precursor chain length on Fischer-Tröpsch cobalt/alumina catalysts

2007 ◽  
Vol 326 (2) ◽  
pp. 164-172 ◽  
Author(s):  
Kalala Jalama ◽  
Neil J. Coville ◽  
Diane Hildebrandt ◽  
David Glasser ◽  
Linda L. Jewell
Keyword(s):  
Chain Length ◽  
Fischer Tropsch ◽  
Precursor Chain ◽  
Alumina Catalysts

Effect of precursor chain-length on the formation and stability of poly(ethylene glycol)-based supramolecular star polymers

2012 ◽  
Vol 50 (12) ◽  
pp. 2415-2420 ◽  
Author(s):  
Ikhlas Gadwal ◽  
Swati De ◽  
Mihaiela C. Stuparu ◽  
Se Gyu Jang ◽  
Roey J. Amir ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Chain Length ◽  
Star Polymers ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Precursor Chain

scholarly journals Numerical model of the spatio-temporal dynamics in a water strider group

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Kovalev ◽  
Alexander E. Filippov ◽  
Stanislav N. Gorb
Keyword(s):  
Loss Rate ◽  
Temporal Dynamics ◽  
Complex Dynamics ◽  
Point Of View ◽  
Stored Energy ◽  
Water Strider ◽  
Population Status ◽  
Appearance Rate ◽  
Spatio Temporal ◽  
Food Assimilation

AbstractThe water strider group demonstrates a very complex dynamics consisting of competition for the food items, territoriality and aggression to the conspecific individuals, escaping from the predators, etc. The situation is even more complex due to the presence of different instars, which in most water strider species live in the same habitat and occupy the same niche. The presented swarm model of water striders demonstrates the realistic population dynamics. For the swarm formation in the model, attraction and repulsion forces were used. Animal motion in the model takes into account inertia and kinetic energy dissipation effects. The model includes three different rates related to the growth of individuals: food appearance rate, food assimilation rate, and stored energy loss rate. The results of our modeling show that the size distribution of individuals seems to be an adequate measure for population status, and it has a characteristic shape for different model parameter combinations. Distribution of the distances between nearest neighbors is other important measure of the population density and its dynamics. Parameters of the model can be tuned in such a way, that the shape of both distributions in a steady phase coincides with that shape observed in a natural population, which helps to understand the factors leading to particular momentary distribution of both parameters (size and distance) in the population. From this point of view, the model can predict how both distributions can further develop from certain state depending on particular combination of factors.

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