Influence of albumen on aggregation and O-2 evolution of protoplasm from Bryopsis hypnoides Lamourou

The extruded protoplasm from the coenocytic green alga, Bryopsis hypnoides Lamouroux, was able to reform a cell wall and develop further into a mature alga in seawater. In this paper, the influence of albumen on the ability of aggregation and on the photosynthesis of protoplasm was examined. Results show that the protoplasm of B. hypnoides could aggregate in either albumen or chicken egg, which is similar to that in seawater. However unlike in seawater, the aggregation from B. hypnoides in albumen and chicken egg failed to develop into a mature individual. Interestingly, the protoplasm of B. hypnoides could maintain its photosynthetic O-2 evolution in albumen and chicken egg, while the time in chicken egg was longer than that in albumen.

Assembly of the protoplasm of Codium fragile (Bryopsidales, Chlorophyta) into new protoplasts

The cell organelles of the coenocytic alga Codium fragile (Sur.) Hariot aggregated rapidly and protoplasts were formed when its protoplasm was extruded out in seawater. Continuous observation showed that there were long and gelatinous threads connecting the cell organelles. The threads contracted, and thus the cell organelles aggregated into protoplasmic masses. The enzyme digestion experiments and Coomassie Brilliant Blue and Anthrone stainings showed that the long and gelatinous threads involved in the formation of the protoplasts might include protein and saccharides as structure components. Nile Red staining indicated that the protoplast primary envelope was non-lipid at first, and then lipid materials integrated into its surface gradually. The fluorescent brightener staining indicated that the cell wall did not regenerate in the newly formed protoplasts and they all disintegrated within 72 h after formation. Transmission electron microscopy of the cell wall of wild C. fragile showed electron-dense material embedded in the whole cell wall at regular intervals. The experiments indicated that C. fragile would be a suitable model alga for studying the formation of protoplasts.

On the continuity of the protoplasm through the walls of vegetable cells

By Walter Gardiner

As regards protoplasm / by James Hutchison Stirling.

This new ed. completed by addition of pt. II, in reference to Mr. Huxley's 2d issue; and of Preface, in reply to Mr. Huxley in "Yeast".

Investigations on microscopic foams and on protoplasm : experiments & observations directed towards a solution of the question of the physical conditions of the phenomena of life /

"Literature": p. [331]-340.

Protoplasm: its origin, varieties, and functions.

"The substance of this essay formed a paper on "The origin and nature of matter and force, and life and mind,' read before the Literary and scientific society of Birkenhead, November, 1901."--Pref.

A coupled SPH-DEM model for fluid and solid mechanics of apple parenchyma cells during drying

A coupled SPH-DEM based two-dimensional (2-D) micro-scale single cell model is developed to predict basic cell-level shrinkage effects of apple parenchyma cells during air drying. In this newly developed drying model, Smoothed Particle Hydrodynamics (SPH) is used to model the low Reynolds Number fluid motions of the cell protoplasm, and a Discrete Element Method (DEM) is employed to simulate the polymer-like cell wall. Simulations results reasonably agree with published experimental drying results on cellular shrinkage properties such as cellular area, diameter and perimeter. These preliminary results indicate that the model is effective for the modelling and simulation of apple parenchyma cells during air drying.

Porohyperelastic analysis to explore mechanical properties of chondrocytes using numerical modeling and experiments : a finite element study

There are many continuum mechanical models have been developed such as liquid drop models, solid models, and so on for single living cell biomechanics studies. However, these models do not give a fully approach to exhibit a clear understanding of the behaviour of single living cells such as swelling behaviour, drag effect, etc. Hence, the porohyperelastic (PHE) model which can capture those aspects would be a good candidature to study cells behaviour (e.g. chondrocytes in this study). In this research, an FEM model of single chondrocyte cell will be developed by using this PHE model to simulate Atomic Force Microscopy (AFM) experimental results with the variation of strain rate. This material model will be compared with viscoelastic model to demonstrate the advantages of PHE model. The results have shown that the maximum value of force applied of PHE model is lower at lower strain rates. This is because the mobile fluid does not have enough time to exude in case of very high strain rate and also due to the lower permeability of the membrane than that of the protoplasm of chondrocyte. This behavior is barely observed in viscoelastic model. Thus, PHE model is the better model for cell biomechanics studies.

Simulation of plant cell shrinkage during drying : A SPH–DEM approach

Plant based dried food products are popular commodities in global market where much research is focused to improve the products and processing techniques. In this regard, numerical modelling is highly applicable and in this work, a coupled meshfree particle-based two-dimensional (2-D) model was developed to simulate micro-scale deformations of plant cells during drying. Smoothed Particle Hydrodynamics (SPH) was used to model the viscous cell protoplasm (cell fluid) by approximating it to an incompressible Newtonian fluid. The visco-elastic characteristic of the cell wall was approximated to a Neo-Hookean solid material augmented with a viscous term and modelled with a Discrete Element Method (DEM). Compared to a previous work [H. C. P. Karunasena, W. Senadeera, Y. T. Gu and R. J. Brown, Appl. Math. Model., 2014], this study proposes three model improvements: linearly decreasing positive cell turgor pressure during drying, cell wall contraction forces and cell wall drying. The improvements made the model more comparable with experimental findings on dried cell morphology and geometric properties such as cell area, diameter, perimeter, roundness, elongation and compactness. This single cell model could be used as a building block for advanced tissue models which are highly applicable for product and process optimizations in Food Engineering.

A particle based model to simulate microscale morphological changes of plant tissues during drying

Fundamental understanding on microscopic physical changes of plant materials is vital to optimize product quality and processing techniques, particularly in food engineering. Although grid-based numerical modelling can assist in this regard, it becomes quite challenging to overcome the inherited complexities of these biological materials especially when such materials undergo critical processing conditions such as drying, where the cellular structure undergoes extreme deformations. In this context, a meshfree particle based model was developed which is fundamentally capable of handling extreme deformations of plant tissues during drying. The model is built by coupling a particle based meshfree technique: Smoothed Particle Hydrodynamics (SPH) and a Discrete Element Method (DEM). Plant cells were initiated as hexagons and aggregated to form a tissue which also accounts for the characteristics of the middle lamella. In each cell, SPH was used to model cell protoplasm and DEM was used to model the cell wall. Drying was incorporated by varying the moisture content, the turgor pressure, and cell wall contraction effects. Compared to the state of the art grid-based microscale plant tissue drying models, the proposed model can be used to simulate tissues under excessive moisture content reductions incorporating cell wall wrinkling. Also, compared to the state of the art SPH-DEM tissue models, the proposed model better replicates real tissues and the cell-cell interactions used ensure efficient computations. Model predictions showed good agreement both qualitatively and quantitatively with experimental findings on dried plant tissues. The proposed modelling approach is fundamentally flexible to study different cellular structures for their microscale morphological changes at dehydration.

Plasmatic Transformation

The session examines the role of the metaphysical and physical in art and animation and how this relates to natural spaces. Soviet Russian film director and theorist Sergei Eisenstein saw animation as possessing an ability called “plasmaticity”, the capacity for a being to assume any conceivable form dynamically. He saw each being as “primordial protoplasm, not yet possessing a ‘stable’ form, but capable of assuming any form” (Eisenstein 1989, 21). He was enamoured by the capacity of animation to transform and be liberated, of being able to escape from a fixed and static identity—to embody a "rejection of the once-­‐and-­‐forever allotted form" in which we are held (Eisenstein 1989, 21). Czech Surrealist animator Jan Švankmajer uses a metaphysical approach based on a belief in animism to art and animation. He believes that objects possess a conscious life or spirit, he says ‘Objects conceal within themselves the events they’ve witnessed. I don’t actually animate objects. I coerce their inner life out of them.’ (Švankmajer in Imre 2009, 214) In this animistic world there are no boundaries or rules, no physical or conceptual restrictions; anything is possible, with inanimate objects and places able to become animate and transact in a conscious relationship with humans and each other. This session invites artists, animators and theorists to discuss their conceptions and approaches to using visuals to promote and provoke transformation.

El plancton de Mar del Plata durante el período 1961-1962 (Buenos Aires, Argentina)

The first part presents a general picture of the composition of the coastal plankton near Mar del Plata (Buenos Aires prov., Argentina) between August 1961-August 1962. Especially noted is the abundance of Noctiluca from October to the end of March. The second part deals with the plankton collected during a short cruise, named Operación Mar del Plata 1, planned to survey coastal waters. In the third part the author gives the descriptions of some new or interesting species. A chain-forming Gymnodinium is reported as G. catenatum; some differences with Graham description, could be due to the fact that he studied only preserved material. Oblea baculifera is a new species belonging to the new genus Oblea, of the Diplopsalis group, created for some species previ¬ously known as Peridiniopsis. A key of the included species is given. The other new species are Peridinium aspidiotum, P. anomaloplaxum, P. lipopodium and Gonyaulax fratercula, all of them carefully described and depicted. Sticholonche zanclea (Radiolaria), Calsiosolenia sinuosa (Coccolithophoridae) and Tintinnopsis levigata (Tintinnida) are reported for the first time in the South-Atlantic. For T. levigata ?, Balech, 1939, a new name has been created: T. tregouboffi. Some unknown details of the protoplasm of the silicoflagellate Dictyocha octonaria are described. In the fourth part the author compares the plankton taken in Mar del Plata with the previously studied at Pto. Quequén. The plankton of March-April points to an invasion of oceanic warm waters from the Brazilian Current System.

Assembly of the subcellular parts of Bryopsis hypnoides Lamouroux into new protoplasts

The chloroplasts, mitochondria, and protoplasm devoid of mature chloroplasts (PMC) of Bryopsis hypnoides Lamouroux were isolated by low-speed and sucrose density centrifugation. The PMC aggregated in artificial seawater, and then protoplasts without mature chloroplasts (PtMCs) were formed. Transmission electron microscopy and cytochemical studies indicated that there were mitochondria, nuclei, vesicles, and other small cell organelles in the PtMCs. Scanning electron microscopy showed that there were holes on the surface of 1-h PtMCs and then fewer holes on the surface of 24-h PtMCs, suggesting that a healing process occurred. The plasma membrane was formed over the surface of the PtMCs. However, the cell wall was not regenerated, and the newly formed PtMCs were ruptured and died in 3 days. Light intensity during alga maintenance before use influenced significantly (one-way ANOVA, P < 0.0001) on the number of PtMCs formed; the highest number of PtMCs was formed at 20A mu mol/(m(2) s). When isolated chloroplasts were transferred into seawater, there were only two or three chloroplasts aggregated together. However, isolated mitochondria and the mixed six layers of cell organelles (separated by sucrose density centrifugation) could not aggregate in the artificial seawater. This indicates that the conjunction of cell organelles is important for their aggregation.