scholarly journals Mathematical principles and models of plant growth mechanics: from cell wall dynamics to tissue morphogenesis

2019 ◽  
Vol 70 (14) ◽  
pp. 3587-3600 ◽  
Author(s):  
Euan T Smithers ◽  
Jingxi Luo ◽  
Rosemary J Dyson

AbstractPlant growth research produces a catalogue of complex open questions. We argue that plant growth is a highly mechanical process, and that mathematics gives an underlying framework with which to probe its fundamental unrevealed mechanisms. This review serves to illustrate the biological insights afforded by mathematical modelling and demonstrate the breadth of mathematically rich problems available within plant sciences, thereby promoting a mutual appreciation across the disciplines. On the one hand, we explain the general mathematical principles behind mechanical growth models; on the other, we describe how modelling addresses specific problems in microscale cell wall mechanics, tip growth, morphogenesis, and stress feedback. We conclude by identifying possible future directions for both biologists and mathematicians, including as yet unanswered questions within various topics, stressing that interdisciplinary collaboration is vital for tackling the challenge of understanding plant growth mechanics.

Author(s):  
Ramiro Remigio Gaibor Fernández ◽  
Abraham Adalberto Bayas Zamora ◽  
Galo Israel Muñoz Sánchez ◽  
Cristhian Adrián Rivas Santacruz

The objective of the present investigation was to evaluate the physical characteristics of the vermicompost and the quality of the purine of the red Californian (Eisenia foetida) using different substrates of feed for these worms. For this purpose, nine treatments were studied: 75% African palm rachis + 25% cattle manure, 50% African palm rachis + 50% cattle manure, 25% African palm rachis + 75% livestock manure, 50% manure of cattle, 50% of manure of cattle, 25% of manure of cattle, 50% of manure of cattle, 50% of manure of cattle, 50% of rach of coconut + 50% of manure of Livestock, 25% coccus rachis + 75% livestock manure. The substrate made up of 50% of rachis of coconut and 50% of livestock manure can be used in nurseries or nurseries for being the one that registered a value of pH 7.3 plus the closest to the neutral compared to the others, besides this (75% of oil palm rachis and 25% of cattle manure) showed a higher content of humic and fulvic acids (0.87 and 0.45 p / p, respectively), compounds that are important for agriculture by stimulating plant growth, in addition to this reflection 0.06% sulfur content, 4.0 ppm boron, 7.0 ppm copper, 47.5 ppm iron, 6.0 ppm manganese, with a presence of microorganisms of the species Trichoderma, Penicillium, Cladosporium sp. in amounts of 1.91x105 UFC / ml, however in this substrate was obtained between 13.3 and 43.5% less liquid slurry in Comparison with other treatments.


2021 ◽  
Vol 10 (2) ◽  
pp. 74
Author(s):  
Vít Pászto ◽  
Jiří Pánek ◽  
René Glas ◽  
Jasper van Vught

Simulation games, as a method of playful learning, have been used for more than 70 years in various disciplines with the economy as a leading application field. Their development has been tied with advances in computer science, and nowadays, hundreds of simulation games exist. However, simulation games are not just useful for encouraging disciplinary knowledge production; they also promise to be effective tools for interdisciplinary collaboration. To further explore these promises, we report on the design and playing of a simulation game on the boundary of geoinformatics and business and economics; an interdisciplinary field we have termed Spationomy. Within this game, students from different disciplinary (and cultural) backgrounds applied their knowledge and skills to tackle interdisciplinary problems. In this paper, we also analyze students’ feedback on the game to complement this aspect. The main goal is to discuss the design process that went into creating the game as well as experiences from play sessions in relation to this increase of interdisciplinary knowledge among students. In the end, we present a new gaming concept based on real-world data that can be played in other interdisciplinary situations. Here, students´ feedback on individual features of the game helped to identify future directions in the development of our simulation game.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1113 ◽  
Author(s):  
Liuyang Han ◽  
Xingling Tian ◽  
Tobias Keplinger ◽  
Haibin Zhou ◽  
Ren Li ◽  
...  

Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, 13C-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N2 nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of β-O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks.


2007 ◽  
Vol 72 (1) ◽  
pp. 171-206 ◽  
Author(s):  
Denis R. Hirschfeldt ◽  
Richard A. Shore

AbstractWe investigate the complexity of various combinatorial theorems about linear and partial orders, from the points of view of computability theory and reverse mathematics. We focus in particular on the principles ADS (Ascending or Descending Sequence), which states that every infinite linear order has either an infinite descending sequence or an infinite ascending sequence, and CAC (Chain-AntiChain), which states that every infinite partial order has either an infinite chain or an infinite antichain. It is wellknown that Ramsey's Theorem for pairs () splits into a stable version () and a cohesive principle (COH). We show that the same is true of ADS and CAC, and that in their cases the stable versions are strictly weaker than the full ones (which is not known to be the case for and ). We also analyze the relationships between these principles and other systems and principles previously studied by reverse mathematics, such as WKL0, DNR, and BΣ2. We show, for instance, that WKL0 is incomparable with all of the systems we study. We also prove computability-theoretic and conservation results for them. Among these results are a strengthening of the fact, proved by Cholak, Jockusch, and Slaman, that COH is -conservative over the base system RCA0. We also prove that CAC does not imply DNR which, combined with a recent result of Hirschfeldt, Jockusch. Kjos-Hanssen, Lempp, and Slaman, shows that CAC does not imply (and so does not imply ). This answers a question of Cholak, Jockusch, and Slaman.Our proofs suggest that the essential distinction between ADS and CAC on the one hand and on the other is that the colorings needed for our analysis are in some way transitive. We formalize this intuition as the notions of transitive and semitransitive colorings and show that the existence of homogeneous sets for such colorings is equivalent to ADS and CAC, respectively. We finish with several open questions.


2011 ◽  
Vol 41 (8) ◽  
pp. 1710-1721 ◽  
Author(s):  
Aaron R. Weiskittel ◽  
Nicholas L. Crookston ◽  
Philip J. Radtke

Assessing forest productivity is important for developing effective management regimes and predicting future growth. Despite some important limitations, the most common means for quantifying forest stand-level potential productivity is site index (SI). Another measure of productivity is gross primary production (GPP). In this paper, SI is compared with GPP estimates obtained from 3-PG and NASA’s MODIS satellite. Models were constructed that predict SI and both measures of GPP from climate variables. Results indicated that a nonparametric model with two climate-related predictor variables explained over 68% and 76% of the variation in SI and GPP, respectively. The relationship between GPP and SI was limited (R2 of 36%–56%), while the relationship between GPP and climate (R2 of 76%–91%) was stronger than the one between SI and climate (R2 of 68%–78%). The developed SI model was used to predict SI under varying expected climate change scenarios. The predominant trend was an increase of 0–5 m in SI, with some sites experiencing reductions of up to 10 m. The developed model can predict SI across a broad geographic scale and into the future, which statistical growth models can use to represent the expected effects of climate change more effectively.


2021 ◽  
Author(s):  
Sare Asli ◽  
Nedal Massalha ◽  
Muhamad Hugerat

Abstract AimsTo determine the effects of treated wastewater (TWW) and dialyzed TWW (DTWW) through dialysis tube with a cut-off at 6000-8000 Da, on the water transport characteristics of maize seedlings (Zea mays L). MethodsLaboratory experiments were conducted to determine the effect of TWW on the hydraulic conductivity of excised roots. Moreover, the effect on transpiration, plant growth, root cell permeability and on the plant fresh and dry weight was determined. ResultsPressurized water flow through the excised primary roots was reduced by 25%-52%, within 90 min of exposure to TWW or DTWW. In hydroponics, DTWW affected root elongation severely by 58 %, while cell-wall pore sizes of same roots were little reduced (by 6%). Additionally, the exposure to TWW or DTWW caused inhibition of both leaf growth rate by (26%-70%) and transpiration by (14%-64%). While in soil growth, the plant fresh and dry weight was also significantly affected but not with secondary DTWW. Conclusions These impacts appeared simultaneously to involve phytotoxic and physical clogging impacts. First, the inhibition in hydraulic conductivity through live roots (phytotoxic and physical effects) after exposure to secondary DTWW was by 22%, while through killed roots accepted after hot alcohol disruption of cell membranes (physical effects only); was only by 14%. Second, although DTWW affected root elongation severely by 58%, cell-wall pore sizes of same roots were little reduced by 6%. We conclude that large molecules, such as polypeptides, remained after the dialysis process, may have produced hormone-like activity that affected root water permeability.


Author(s):  
Paola Spagnoli ◽  
Cristian Balducci ◽  
Liliya Scafuri Kovalchuk ◽  
Francesco Maiorano ◽  
Carmela Buono

Although the interplay between workaholism and work engagement could explain several open questions regarding the Heavy Work Investment (HWI) phenomenon, few studies have addressed this issue. Thus, with the purpose of filling this literature gap, the present study aimed at examining a model where job-related negative affect mediates the relationship between the interplay of workaholism and work engagement, and anxiety before sleep. Since gender could have a role in the way the interplay would impact on the theorized model, we also hypothesized a moderated role of gender on the specific connection concerning the interplay between workaholism and work engagement, in relation to job-related negative affect. Conditional process analysis was conducted on a sample of 146 participants, balanced for gender. Results supported the mediating model and indicated the presence of a moderated role of gender, such that engaged workaholic women reported significantly less job-related negative affect than disengaged workaholic women. On the contrary, the interplay between workaholism and work engagement did not seem significant for men. Results are discussed in light of the limitations and future directions of the research in this field, as well as the ensuing practical implications.


2020 ◽  
Author(s):  
Colin Peter Singer Kruse ◽  
Alexander D Meyers ◽  
Proma Basu ◽  
Sarahann Hutchinson ◽  
Darron R Luesse ◽  
...  

Abstract Background: Understanding of gravity sensing and response is critical to long-term human habitation in space and can provide new advantages for terrestrial agriculture. To this end, the altered gene expression profile induced by microgravity has been repeatedly queried by microarray and RNA-seq experiments to understand gravitropism. However, the quantification of altered protein abundance in space has been minimally investigated. Results: Proteomic (iTRAQ-labelled LC-MS/MS) and transcriptomic (RNA-seq) analyses simultaneously quantified protein and transcript differential expression of three-day old, etiolated Arabidopsis thaliana seedlings grown aboard the International Space Station along with their ground control counterparts. Protein extracts were fractionated to isolate soluble and membrane proteins and analyzed to detect differentially phosphorylated peptides. In total, 968 RNAs, 107 soluble proteins, and 103 membrane proteins were identified as differentially expressed. In addition, the proteomic analyses identified 16 differential phosphorylation events. Proteomic data delivered novel insights and simultaneously provided new context to previously made observations of gene expression in microgravity. There is a sweeping shift in post-transcriptional mechanisms of gene regulation including RNA-decapping protein DCP5, the splicing factors GRP7 and GRP8, and AGO4,. These data also indicate AHA2 and FERONIA as well as CESA1 and SHOU4 as central to the cell wall adaptations seen in spaceflight. Patterns of tubulin-a 1, 3,4 and 6 phosphorylation further reveal an interaction of microtubule and redox homeostasis that mirrors osmotic response signaling elements. The absence of gravity also results in a seemingly wasteful dysregulation of plastid gene transcription. Conclusions: The datasets gathered from Arabidopsis seedlings exposed to microgravity revealed marked impacts on post-transcriptional regulation, cell wall synthesis, redox/microtubule dynamics, and plastid gene transcription. The impact of post-transcriptional regulatory alterations represents an unstudied element of the plant microgravity response with the potential to significantly impact plant growth efficiency and beyond. What’s more, addressing the effects of microgravity on AHA2, CESA1, and alpha tubulins has the potential to enhance cytoskeletal organization and cell wall composition, thereby enhancing biomass production and growth in microgravity. Finally, understanding and manipulating the dysregulation of plastid gene transcription has further potential to address the goal of enhancing plant growth in the stressful conditions of microgravity.


2015 ◽  
Vol 15 (3) ◽  
Author(s):  
Alexandria Heaton Carrico

In this article, I investigate the ways in which methodological exchange between the fields of medical ethnomusicology and music therapy (MT) creates an interdisciplinary two-way street which, on the one hand enhances therapeutic practice by adopting an ethnographic and cultural understanding of disability, and on the other enriches ethnomusicological studies by ethnographically utilizing music therapy techniques. In support of this viewpoint, I offer ethnographic accounts of my time conducting research on music and Williams Syndrome and working alongside music therapists at the Whispering Trails summer camp for children with Williams Syndrome (WS) in Grand Rapids, Michigan. Ultimately, I argue that synergistic collaboration between the fields of medical ethnomusicology and music therapy will not only augment scholarship in these areas, but will also allow ethnomusicologists and music therapists to address issues of social justice and to promote accommodation and acceptance for disability within society.


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