scholarly journals Mathematical model for tissue stresses in growing plant cells and organs

2011 ◽  
Vol 78 (1) ◽  
pp. 19-23
Author(s):  
Mariusz Pietruszka ◽  
Sylwia Lewicka

In this study we propose a simple mathematical model based on the equilibrium equation for the materials deformed elastically. Owing to the turgor pressure of the cells, the peripheral walls of the outer tissue are under tension, while the extensible inner tissue is under compression. This well known properties of growing multicellular plant organs can be derived from the equation for equilibrium. The analytic solutions may serve as a good starting point for modeling the growth of a single plant cell or an organ.

1985 ◽  
Vol 33 (4) ◽  
pp. 345-352 ◽  
Author(s):  
D H Simmonds ◽  
R W Seagull ◽  
G Setterfield

Various modifications to the immunofluorescent labeling procedures for microtubules in plant cells have been compared using cell cultures of Vicia hajastana Grossh. Using serial section electron microscopic reconstructions as a reference, we have chosen as our standard procedure a method that maximizes both the preservation of the cytoskeleton and the proportion of cells staining, while minimizing the degree of nonspecific staining. The critical steps of the procedure include stabilization of the cytoskeleton, cell wall permeabilization, and cell extraction. To maintain structural integrity during the procedure, it is necessary to stabilize the cytoskeleton with paraformaldehyde. To facilitate antibody penetration into the cell, it was necessary that the walls be made permeable via partial enzymatic digestion. Detergent extraction of cells increased the proportion of cells staining and decreased the level of nonspecific binding of the antibodies. The procedures detailed in this article provide a good starting point for the application of immunofluorescent labeling techniques to other plant systems.


2021 ◽  
Vol 14 (3) ◽  
pp. 203 ◽  
Author(s):  
Shurong Hou ◽  
Juan Diez ◽  
Chao Wang ◽  
Christoph Becker-Pauly ◽  
Gregg B. Fields ◽  
...  

Meprin α and β are zinc-dependent proteinases implicated in multiple diseases including cancers, fibrosis, and Alzheimer’s. However, until recently, only a few inhibitors of either meprin were reported and no inhibitors are in preclinical development. Moreover, inhibitors of other metzincins developed in previous years are not effective in inhibiting meprins suggesting the need for de novo discovery effort. To address the paucity of tractable meprin inhibitors we developed ultrahigh-throughput assays and conducted parallel screening of >650,000 compounds against each meprin. As a result of this effort, we identified five selective meprin α hits belonging to three different chemotypes (triazole-hydroxyacetamides, sulfonamide-hydroxypropanamides, and phenoxy-hydroxyacetamides). These hits demonstrated a nanomolar to micromolar inhibitory activity against meprin α with low cytotoxicity and >30-fold selectivity against meprin β and other related metzincincs. These selective inhibitors of meprin α provide a good starting point for further optimization.


2021 ◽  
Vol 13 (7) ◽  
pp. 3816
Author(s):  
Javier Rodrigo-Ilarri ◽  
Camilo-A. Vargas-Terranova ◽  
María-Elena Rodrigo-Clavero ◽  
Paula-A. Bustos-Castro

For the first time in the scientific literature, this research shows an analysis of the implementation of circular economy techniques under sustainable development framework in six municipalities with a depressed economy in Colombia. The analysis is based on solid waste data production at a local scale, the valuation of the waste for subsequent recycling, and the identification and quantification of the variables associated with the treatment and final disposal of waste, in accordance with the Colombian regulatory framework. Waste generation data are obtained considering three different scenarios, in which a comparison between the simulated values and those established in the management plans are compared. Important differences have been identified between the waste management programs of each municipality, specifically regarding the components of waste collection, transportation and disposal, participation of environmental reclaimers, and potential use of materials. These differences are fundamentally associated with the different administrative processes considered for each individual municipality. This research is a good starting point for the development of waste management models based on circular economy techniques, through the subsequent implementation of an office tool in depressed regions such as those studied.


2007 ◽  
Vol 14 (4) ◽  
pp. 313-319
Author(s):  
Benedikt Buchner

AbstractIndustry-sponsored medical education is a much disputed issue. So far, there has been no regulatory framework which provides clear and definite rules as to whether and under what circumstances the sponsorship of medical education is acceptable. State regulation does not exist, or confines itself to a very general principle. Professional regulation, even though applied frequently, is rather vague and indefinite, raising the general question as to whether self-regulation is the right approach at all. Certainly, self-regulation by industry cannot and should not replace other regulatory approaches. Ultimately, advertising law in general and the European Directive 2001/83/EC specifically, might be a good starting point in providing legal certainty and ensuring the independence of medical education. Swiss advertising law illustrates how the principles of the European Directive could be implemented clearly and unambiguously.


2013 ◽  
Vol 13 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Frans M. Klis ◽  
Chris G. de Koster ◽  
Stanley Brul

ABSTRACTBionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeastSaccharomyces cerevisiaeand the polymorphic, pathogenic fungusCandida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation ofin vivovalues. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allowsC. albicansto cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species.


Sign in / Sign up

Export Citation Format

Share Document