A Study of Nuclei and Intercellular Ground Substance during the in situ Differentiation of Somites in Taricha torosa

Development ◽  
1961 ◽  
Vol 9 (4) ◽  
pp. 650-660
Author(s):  
Cyril V. Finnegan
Keyword(s):  
Morphological Changes ◽  
Periodic Acid ◽  
Ground Substance ◽  
Tail Bud ◽  
Interphase Nuclei ◽  
Taricha Torosa ◽  
Intercellular Matrix ◽  
Schiff Reagent

In order better to evaluate results obtained in this laboratory concerning the responses of differentiating postneurula somite tissue to other mesoderm tissue placed in its immediate vicinity (Finnegan, unpublished), it was necessary to examine somite differentiation in situ. A qualitative examination of somite interphase nuclei of tail-bud and later stages was performed to note their morphological changes since it was assumed, as suggested by Briggs & King (1955), that such changes indicate cellular differentiation and, conversely, that absence of such changes indicates that the cells are not actively differentiating. Because of the possible role of the intercellular matrix in histogenesis (see Grobstein, 1954, 1959; and Edds, 1958) a study was made of the development in the somite of that portion of the intercellular matrix which is demonstrable histochemically with the periodic acid-Schirf (PAS) technique. The visual clarity of the results has been materially aided by the fluorescent Schiff reagent of Culling & Vassar (1961) which makes possible a fluorescent Feulgen and a fluorescent PAS reaction.

In situobservation of morphological changes of γ′ precipitates in a pre-deformed single-crystal Ni-base superalloy

2011 ◽  
Vol 44 (5) ◽  
pp. 935-944 ◽  
Author(s):  
Pavel Strunz ◽  
Gerhard Schumacher ◽  
Hellmuth Klingelhöffer ◽  
Albrecht Wiedenmann ◽  
Jan Šaroun ◽  
...  
Keyword(s):  
External Load ◽  
Morphological Changes ◽  
The Past ◽  
Subsequent Heating ◽  
Detailed Evaluation ◽  
The Matrix ◽  
Base Superalloy

Exposure of a superalloy to an external load results in anisotropic coarsening of the γ′ precipitates, so-called rafting. It was reported in the past that γ′ rafting can also occur as a result of purely thermal treatment, without the simultaneous presence of an external load, if the specimen has been pre-deformed at relatively low temperature. The evolution of γ′ morphology in pre-deformed specimens of SCA425 Ni-base superalloy was examined in the present study. Unlike in the previous experiments, the compressive stress was used for pre-straining.In situsmall-angle neutron scattering (SANS) was employed, which enabled the determination of the morphology directly at high temperature. Both for strong and for weak pre-straining, rounding of the originally cuboidal precipitates towards an ellipsoidal shape on heating was observed. Weak pre-straining (0.1, 0.5%) does not cause rafting on subsequent heating. On the other hand, the detailed evaluation of SANS data provides some indication of rafting during the subsequent heating after severe compressive pre-straining (2%). The experiment indicates the role of dislocation rearrangement at the matrix/precipitate interface during pre-straining.

scholarly journals 271.Role of homeobox gene HLX expression in normal placental development

2004 ◽  
Vol 16 (9) ◽  
pp. 271
Author(s):  
P. Murthi ◽  
M. D. Bates ◽  
G. Sankaran ◽  
S. P. Brennecke ◽  
B. Kalionis
Keyword(s):  
Alkaline Phosphatase ◽  
Morphological Changes ◽  
Homeobox Gene ◽  
Giant Cells ◽  
Placental Development ◽  
Structural Support ◽  
Alkaline Phosphatase Staining ◽  
Phd Thesis

In a screen for homeobox genes in the human placenta, we cloned and characterised HLX1 (also known as HB24) (1). Furthermore, we provided evidence that HLX1 may be a regulator of human placental develolpment (2). We have since shown that the mouse homologue of HLX1, called Hlx, is expressed in the murine placenta. In situ mRNA hybridisation studies and antibody localisation of Hlx revealed expression in the labyrinth layer (LL), secondary giant cells (GC) and in the spongiotrophoblast layer (STL) (3). The STL is required for structural support of the placenta. Targeted gene mutation of Hlx resulted in embryonic defects in the developing gut and the liver (4) but the effects on placental development were not investigated. Histological preparations of placental tissues collected from Days 10.5, 13.5 and 19.5 from Hlx mutant mice were investigated for morphological changes. Our preliminary observations reveal that by haematoxylin and eosin staining the STL of the mutant murine placenta is severely disrupted but the overlying GC layer appears to be unaffected. Endogenous alkaline phosphatase staining of the LL further confirmed that the highly vascularised LL where fetal- maternal exchange occurs, is disorganised and expands into the region normally occupied by the STL. These observations indicate that Hlx is essential for normal placental development. (1) Quinn LM, Kalionis B. (1997) Gene 187, 55–61. (2) Quinn LM, Kalionis B. (1997) Repro. Dev. 9, 617–623. (3) Johnson B (1999) PhD Thesis, University of Adelaide. (4) Hentsch B, Harvey RP (1996) Gene Dev. 10, 70–79.

Quantification of biofilm exopolysaccharides using an in situ assay with periodic acid–Schiff reagent

2016 ◽  
Vol 500 ◽  
pp. 12-14 ◽  
Author(s):  
I. Randrianjatovo-Gbalou ◽  
E. Girbal-Neuhauser ◽  
C.-E. Marcato-Romain
Keyword(s):  
Periodic Acid ◽  
Periodic Acid Schiff ◽  
Schiff Reagent ◽  
In Situ Assay

High-Pressure Ignition of Oil Sands Samples in Oxygen Atmospheres Containing Various Concentrations of Diluents

1990 ◽  
Vol 112 (4) ◽  
pp. 264-267 ◽  
Author(s):  
S. A. Mehta ◽  
G. A. Karim
Keyword(s):  
High Pressure ◽  
Oil Sands ◽  
Morphological Changes ◽  
Pure Oxygen ◽  
Experimental Program ◽  
Nickel Chromium ◽  
Ignition Characteristics ◽  
Combustion Processes

In-situ recovery of oil from oil sands deposits by combustion requires the injection of vast quantities of oxygen into the bed of deposits. Accordingly, there is a need to establish the ignition characteristics of high-grade Athabasca oil sands in environments containing pure oxygen at high-pressure and including the role of the presence of various diluents with the oxygen. A high-pressure constant volume bomb with a water calorimeter was employed as the test apparatus over the pressure range of 0.1 MPa to 4.0 MPa at ambient temperature. The role of the presence of the diluents, helium, nitrogen and carbon dioxide, with the oxygen, was also considered. Controlled ignition was achieved by employing electrically fusable nickel-chromium wire looped around the sample. Moreover, the presence of an ignition promotor such as benzoic acid was also considered. The paper presents the results of an experimental program that examined the effects of changes in the pressure, amounts of diluents and ignition energy on the ignition limits and subsequent combustion processes at ambient initial temperature. Moreover, the morphological changes to the samples at various stages of the process were also examined and discussed.

The Role of Microtubule Organization in Chondrocyte Response to Osmotic Loading

2007 ◽  
Author(s):  
Elizabeth S. Oswald ◽  
Pen-hsiu Grace Chao ◽  
J. Chloe Bulinski ◽  
Gerard A. Ateshian ◽  
Clark T. Hung
Keyword(s):  
Intracellular Transport ◽  
Morphological Changes ◽  
Cellular Responses ◽  
Microtubule Organization ◽  
Osmotic Loading ◽  
Volume Response ◽  
Cytoplasmic Organization

The cytoskeleton, including actin filaments and microtubules, provides chondrocytes with structure, cytoplasmic organization, and intracellular transport. The cytoskeleton is known to be involved in cellular responses to physiologic mechanical and osmotic loading signals, including morphological changes and mechanostransduction [1, 2]. Here, we examine microtubule (MT) involvement in volume response of chondrocytes to osmotic loading, as well as organization of stable MT with hypoosmotic loading. We also explore the hypothesis that chondrocytes from different zones of cartilage possess cytoskeletons with different properties, which help explain variations in their volume response to osmotic loading in situ and in vitro [3].

Exploring the relationship between interphase gene positioning, transcriptional regulation and the nuclear matrix

2010 ◽  
Vol 38 (1) ◽  
pp. 263-267 ◽  
Author(s):  
Lauren S. Elcock ◽  
Joanna M. Bridger
Keyword(s):  
Nuclear Matrix ◽  
Local Scale ◽  
Proliferating Cells ◽  
Interphase Nuclei ◽  
Gene Positioning ◽  
Global Organization ◽  
Spatial Positioning ◽  
The Relationship

Since the advent of FISH (fluorescence in situ hybridization), there have been major advances in our understanding of how the genome is organized in interphase nuclei. Indeed, this organization is found to be non-random and individual chromosomes occupy discrete regions known as territories. Determining the factors that drive the spatial positioning of these territories within nuclei has caused much debate; however, in proliferating cells, there is evidently a correlation between radial positioning and gene density. Indeed, gene-poor chromosomes tend to be located towards the nuclear edge, while those that are more gene-rich are positioned more internally. These observations pose a number of questions: first, what is the function of this global organization and, secondly, is it representative of that occurring at a more local scale? During the course of this review, these questions will be considered, in light of the current literature regarding the role of transcription factories and the nuclear matrix in interphase genome organization.

{10-12} Twinning Mechanism During In Situ Micro-Tensile Loading of Pure Mg: Role of Basal Slip and Twin-Twin Boundary Interaction

2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  
Keyword(s):  
Twin Boundary ◽  
Basal Slip ◽  
Tensile Loading ◽  
Boundary Interaction

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

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