scholarly journals MICROTUBULES IN THE FORMATION AND DEVELOPMENT OF THE PRIMARY MESENCHYME IN ARBACIA PUNCTULATA

1969 ◽  
Vol 41 (1) ◽  
pp. 227-250 ◽  
Author(s):  
Lewis G. Tilney ◽  
John R. Gibbins
Keyword(s):  
Hydrostatic Pressure ◽  
Sea Urchin ◽  
Cell Shape ◽  
Preceding Paper ◽  
Careful Analysis ◽  
The Other ◽  
Arbacia Punctulata ◽  
Cell Form ◽  
Cytoplasmic Microtubules ◽  
Made In

To experimentally test the suggestion made in the preceding paper that the microtubules are involved in cell shape development during the formation and differentiation of the primary mesenchyme, we applied to the embryos two types of agents which affect cytoplasmic microtubules: (a) colchicine and hydrostatic pressure, which cause the microtubules to disassemble, and (b) D2O, which tends to stabilize them. When the first type of agent is applied to sea urchin gastrulae, the development of the primary mesenchyme ceases, the microtubules disappear, and the cells tend to spherulate. With D2O development also ceases, but the tubules appear "frozen," and the cell asymmetries persist unaltered. These agents appear to block development by primarily interfering with the sequential disassembly and/or reassembly of microtubules into new patterns. The microtubules, therefore, appear to be influential in the development of cell form. On the other hand through a careful analysis of the action of these agents and others on both intra- and extracellular factors, we concluded that the microtubules do rather little for the maintenance of cell shape in differentiated tissues.

scholarly journals MICROTUBULE BIOGENESIS AND CELL SHAPE IN OCHROMONAS

1973 ◽  
Vol 56 (2) ◽  
pp. 360-378 ◽  
Author(s):  
David L. Brown ◽  
G. Benjamin Bouck
Keyword(s):  
Cell Shape ◽  
Preceding Paper ◽  
Cell Organelles ◽  
Site Function ◽  
Specific Shape ◽  
Cytoplasmic Microtubules ◽  
Normal Shape ◽  
Species Specific ◽  
Anterior Direction ◽  
Made In

The proposal made in the preceding paper that the species-specific shape of Ochromonas is mediated by cytoplasmic microtubules which are related to two nucleating sites has been experimentally verified. Exposure of cells to colchicine or hydrostatic pressure causes microtubule disassembly and a correlative loss of cell shape in a posterior to anterior direction. Upon removal of colchicine or release of pressure, cell shape regenerates and microtubules reappear, first in association with the kineto-beak site concomitant with regeneration of the anterior asymmetry, and later at the rhizoplast site concomitant with formation of the posterior tail. It is concluded that two separate sets of cytoplasmic tubules function in formation and maintenance of specific portions of the total cell shape. On the basis of the following observations, we further suggest that the beak and rhizoplast sites could exert control over the position and timing of the appearance, the orientation, and the pattern of microtubule distribution in Ochromonas. (a) the two sites are accurately positioned in the cell relative to other cell organelles; (b) in regenerating cells microtubules reform first at these sites and appear to elongate to the cell posterior; (c) microtubules initially reappear in the orientation characteristic of the fully differentiated cell; (d) the two sets of tubules are polymerized at different times, in the same sequence, during reassembly or resynthesis of the microtubular system. Experiments using cycloheximide, after a treatment with colchicine, have demonstrated that Ochromonas cannot reassume its normal shape without new protein synthesis. This suggests that microtubule protein once exposed to colchicine cannot be reassembled into microtubules. Pressure-treated cells, on the other hand, reassemble tubules and regenerate the normal shape in the presence or absence of cycloheximide. The use of these two agents in analyzing nucleating site function and the independent processes of synthesis and assembly of microtubules is discussed.

scholarly journals NUCLEATING SITES FOR THE ASSEMBLY OF CYTOPLASMIC MICROTUBULES IN THE ECTODERMAL CELLS OF BLASTULAE OF ARBACIA PUNCTULATA

1970 ◽  
Vol 46 (3) ◽  
pp. 564-575 ◽  
Author(s):  
Lewis G. Tilney ◽  
Janette Goddard
Keyword(s):  
Low Temperature ◽  
Sea Urchin ◽  
Basal Body ◽  
Preliminary Report ◽  
Apical Part ◽  
Basal Region ◽  
Serial Sections ◽  
Arbacia Punctulata ◽  
Early Stages ◽  
Cytoplasmic Microtubules

In the ectodermal cells of sea urchin blastulae, the microtubules converge and appear to make contact with three distinct cytoplasmic foci or satellites associated with the basal body of the cilium. Beneath the nucleus, which lies in the apical end of the cell, the microtubules are aligned predominantly parallel to the cell's long axis and could thus make contact with the satellites as is directly suggested by observations on sections at or near the planes of the satellites. After the embryos are treated with low temperature (0°C), the microtubules disassemble; however, the satellites can still be recognized. Upon rewarming, the microtubules reappear. In early stages of reformation, when the tubules in the cell consist of short segments, tubules have only been found in the apical part of the cell. One end of each microtubule appears to make contact with its respective satellite, or is aligned so that it could contact one of the satellites, provided serial sections were cut and collected in order. After longer periods of recovery, the microtubules elongate; as before, one end of each makes contact with a satellite or is aligned so that it could attach to a satellite. Segments of microtubules seen in the basal region of the cell are aligned parallel to the long axis of the cell as in the untreated ectodermal cells and are therefore interpreted as extensions of those tubules making contact with one of the satellites. On the basis of these observations, we suggest that assembly of microtubules is initiated at the satellites. These sites, perhaps best referred to as "nucleating sites," thereby could exert considerable control over the distribution of microtubules in cells. It is hoped that this preliminary report will be followed up by a more detailed study using serial sections.

Microtubules and Filaments in the Filopodia of the Secondary Mesenchyme Cells of Arbacia Punctulata and Echinarachnius Parma

1969 ◽  
Vol 5 (1) ◽  
pp. 195-210
Author(s):  
L. G. TILNEY ◽  
J. R. GIBBINS
Keyword(s):  
Fine Structure ◽  
Hydrostatic Pressure ◽  
Cell Body ◽  
The Other ◽  
Arbacia Punctulata ◽  
Contraction Process ◽  
Other Hand ◽  
Mesenchyme Cells

In an attempt to understand the mechanism of contraction of the filopodia of the secondary mesenchyme cells and thus secondary invagination of the archenteron, the fine structure of these processes was examined. Whereas microtubules are commonly encountered in the cell body and at the base of the filopodia, very few (one or two) are present near the tip of the filopodia. Instead the slender processes are filled with 50-Å filaments. Colchicine and hydrostatic pressure were applied to the embryos to elucidate the action of these different fibrous elements. Both agents cause cessation of archenteron movement and the disassembly of the microtubules. Hydrostatic pressure causes the disappearance of the filaments as well. Because of the small numbers of microtubules in the slender filopodia and the fact that in no other system is there any evidence for contraction of these elements, it was concluded that they do not function in the contraction process, but are probably involved in the formation of these cell extensions: hence the effect of colchicine on archenteron movement. The 50-Å filaments, on the other hand, are likely candidates for the contraction process.

scholarly journals High Hydrostatic Pressure as a Tool to Reduce Formation of Biogenic Amines in Artisanal Spanish Cheeses

Foods ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 137 ◽  
Author(s):  
Diana Espinosa-Pesqueira ◽  
Maria Hernández-Herrero ◽  
Artur Roig-Sagués
Keyword(s):  
Amino Acids ◽  
Hydrostatic Pressure ◽  
Biogenic Amines ◽  
High Hydrostatic Pressure ◽  
Free Amino ◽  
Raw Milk ◽  
The Other ◽  
Microbial Counts ◽  
Control Samples ◽  
Made In

Two artisanal varieties of cheese made in Spain, one made of ewes’ raw milk and the other of goats’ raw milk were selected to evaluate the effect of a high hydrostatic pressure (HHP) treatment at 400 MPa during 10 min at 2 °C on the formation of biogenic amines (BA). These conditions were applied at the beginning of the ripening (before the 5th day; HHP1) and in the case of ewes’ milk cheeses also after 15th days (HHP15). BA formation was greatly influenced by HHP treatments in both types of cheese. HHP1 treatments significantly reduced the amounts of BA after ripening, being tyramine and putrescine the most affected BA in goats’ milk cheeses and tyramine and cadaverine in ewes’ milk cheeses. The BA reduction in the HHP1 samples could be explained by the significant decrease in microbiological counts, especially in the LAB, enteroccocci and enterobacteria groups at the beginning of ripening. The proteolysis in these samples was also affected reducing the amount of free amino acids. Although proteolysis in ewes’ milk cheeses HHP15 was similar than in control samples a reduction of BA was observed probably because the decrease caused on microbial counts.

On the Future of the Financial Redistribution across Member States in the EU

2006 ◽  
Vol 56 (1) ◽  
pp. 1-43
Author(s):  
Sándor Richter
Keyword(s):  
Value Added ◽  
The Other ◽  
Current Debate ◽  
Member States ◽  
New Member States ◽  
Financial Position ◽  
Cross Member ◽  
Expenditure Structure ◽  
The Eu ◽  
Made In

The order and modalities of cross-member state redistribution as well as the net financial position of the member states are one of the most widely discussed aspects of European integration. The paper addresses selected issues in the current debate on the EU budget for the period 2007 to 2013 and introduces four scenarios. The first is identical to the European Commission's proposal; the second is based on reducing the budget to 1% of the EU's GNI, as proposed by the six net-payer countries, while maintaining the expenditure structure of the Commission's proposal. The next two scenarios represent radical reforms: one of them also features a '1% EU GNI'; however, the expenditures for providing 'EU-wide value-added' are left unchanged and it is envisaged that the requisite cuts will be made in the expenditures earmarked for cohesion. The other reform scenario is different from the former one in that the cohesion-related expenditures are left unchanged and the expenditures for providing 'EU-wide value-added' are reduced. After the comparison of the various scenarios, the allocation of transfers to the new member states in terms of the conditions prevailing in the different scenarios is analysed.

Physical and Mechanical Properties of Tenun Pahang Fabrics using Alternative Yarns

2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Silk Fabrics ◽  
Recovery Angle ◽  
Made In

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.

Intermedialität

2006 ◽  
Vol 51 (2) ◽  
pp. 52-78 ◽  
Author(s):  
Corina Caduff ◽  
Sabina Gebhardt Fink ◽  
Florian Keller ◽  
Steffen Schmidt
Keyword(s):  
Visual Arts ◽  
The Other ◽  
Systematic Description ◽  
Artistic Representations ◽  
Music Literature ◽  
Music Film ◽  
Made In

Intermedialität wird hier systematisch an Musik, Literatur, visuelle Kunst und Film dargestellt. Den Anfang machen allgemeine Überlegungen zu Materialität und Medium in diesen verschiedenen Künsten. Im Weiteren werden unter dem Aspekt ›Bimedialität‹ verschiedene Beispiele vorgestellt, die jeweils aus zwei Medien bestehen (z.B. Musikfilm, das Lied oder Schriftbilder). Dabei folgen wir der Frage, ob und wie jeweils eines der beiden Medien eine Vorrangstellung bekommt. Der abschließende Teil behandelt „intermediale Bezüge in Monomedialität“. Hier geht es um monomediale Darstellungen, denen aber eine Beschäftigung mit einem anderen Medium vorangegangen ist. Das ist etwa dann der Fall, wenn ein Schriftsteller über ein Bild schreibt, ohne daß dieses (im Text) zu sehen ist. In this article, we offer a systematic description of intermedia relations across music, literature, the visual arts, and film. Beginning with some general reflections on materiality and medium in these diverse fields of art, we then offer various examples consisting of two media (e.g. music film, song, images in writing). We pursue the question if, and how, one of the two media may take priority over the other. In our conclusion, we deal with „intermedia relations in monomediality“. This section focuses on artistic representations made in one medium, but based on reflections on another medium. For instance, this is the case when a novelist writes about a picture without having this picture reprinted in the text.

RECYCLED BRICK SOUNDPROOF TEST AS AN ALTERNATIVE SUSTAINABLE MATERIAL

2020 ◽  
Vol 13 (2) ◽  
pp. 44-54
Author(s):  
Hendrico Firzandy Latupeirissa ◽  
Gierlang Bhakti Putra ◽  
Niki Prastomo
Keyword(s):  
Waste Disposal ◽  
Sound Source ◽  
Building Material ◽  
Building Materials ◽  
Negative Impact ◽  
The Other ◽  
Human Comfort ◽  
Construction Waste ◽  
Coarse Grains ◽  
Made In

Brick debris that makes up the majority of construction waste has not received proper waste disposal in Indonesia. On the other hand, brick debris could be potentially reused as non-structural building materials to reduce its negative impact on the environment. This study aims to test the effectiveness of soundproofing on recycled brick debris. The soundproof test was carried out on brick debris in the form of fine and coarse grains. The simulation box is then used as a support for the brickwork material and then the box is exposed to a sound source with a certain level of noise that is considered disturbing human comfort. Noise level measurements are made in the outside and inside the box. These measurements are tabulated and then analyzed to see the success of the two aggregates in reducing noise. Basically, the brickwork material has succeeded in becoming a recycled building material that can absorb noise, although further research must be carried out to be able to state that this material is truly ready to be used as an alternative building material with good acoustic capabilities.

Call Your "Mutha"

2020 ◽  
Author(s):  
Jane Caputi
Keyword(s):  
African American ◽  
Popular Culture ◽  
The Other ◽  
Political Class ◽  
Mother Nature ◽  
And Gender ◽  
Mother Earth ◽  
Made In

The proposed new geological era, The Anthropocene (a.k.a. Age of Humans, Age of Man), marking human domination of the planet long called Mother Earth, is truly The Age of the Motherfucker. The ecocide of the Anthropocene is the responsibility of Man, the Western- and masculine-identified corporate, military, intellectual, and political class that masks itself as the exemplar of the civilized and the human. The word motherfucker was invented by the enslaved children of White slave masters to name their mothers’ rapist/owners. Man’s strategic motherfucking, from the personal to the planetary, is invasion, exploitation, spirit-breaking, extraction and toxic wasting of individuals, communities, and lands, for reasons of pleasure, plunder, and profit. Ecocide is attempted deicide of Mother Nature-Earth, reflecting Man’s goal to become the god he first made in his own image. The motivational word Motherfucker has a flip side, further revealing the Anthropocene as it signifies an outstanding, formidable, and inexorable force. Mother Nature-Earth is that “Mutha’ ”—one defying translation into heteropatriarchal classifications of gender, one capable of overwhelming Man, and not the other way around. Drawing upon Indigenous and African American scholarship; ecofeminism; ecowomanism; green activism; femme, queer, and gender non-binary philosophies; literature and arts; Afrofuturism; and popular culture, Call Your “Mutha’ ” contends that the Anthropocene is not evidence of Man’s supremacy over nature, but that Mother Nature-Earth, faced with disrespect, is going away. It is imperative now to call the “Mutha’ ” by decolonizing land, bodies, and minds, ending rapism, feeding the green, renewing sustaining patterns, and affirming devotion to Mother Nature-Earth.

scholarly journals Whither Magnetic Hyperthermia? A Tentative Roadmap

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 706
Author(s):  
Irene Rubia-Rodríguez ◽  
Antonio Santana-Otero ◽  
Simo Spassov ◽  
Etelka Tombácz ◽  
Christer Johansson ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Nanoparticle Synthesis ◽  
Careful Analysis ◽  
Magnetic Hyperthermia ◽  
Lessons Learned ◽  
In Vivo Testing ◽  
Evolution Of Science ◽  
Made In ◽  
Critical Aspects

The scientific community has made great efforts in advancing magnetic hyperthermia for the last two decades after going through a sizeable research lapse from its establishment. All the progress made in various topics ranging from nanoparticle synthesis to biocompatibilization and in vivo testing have been seeking to push the forefront towards some new clinical trials. As many, they did not go at the expected pace. Today, fruitful international cooperation and the wisdom gain after a careful analysis of the lessons learned from seminal clinical trials allow us to have a future with better guarantees for a more definitive takeoff of this genuine nanotherapy against cancer. Deliberately giving prominence to a number of critical aspects, this opinion review offers a blend of state-of-the-art hints and glimpses into the future of the therapy, considering the expected evolution of science and technology behind magnetic hyperthermia.

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