Ecophysiological Differences Among Growth Stages of Quercus laevis in a Sandhill Oak Community

1998 ◽  
Vol 125 (1) ◽  
pp. 3 ◽  
Author(s):  
Lisa A. Donovan ◽  
Rebecca A. Pappert
Keyword(s):  
Growth Stages ◽  
Quercus Laevis

Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

1978 ◽  
Vol 36 (2) ◽  
pp. 600-601
Author(s):  
Wiktor Djaczenko ◽  
Carmen Calenda Cimmino
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Early Period ◽  
Postembryonic Development ◽  
Ruthenium Red ◽  
The Body ◽  
Tubifex Tubifex ◽  
Growth Stages ◽  
Cell Processes ◽  
Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

Characterisation of multilayer materials using a position-sensitive atom probe

1990 ◽  
Vol 48 (4) ◽  
pp. 624-625
Author(s):  
RAD Mackenzie ◽  
G D W Smith ◽  
A. Cerezo ◽  
J A Liddle ◽  
CRM Grovenor ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Information ◽  
Chemical Vapour ◽  
Atom Probe ◽  
Organic Chemical ◽  
Growth Stages ◽  
Multiple Quantum ◽  
Quartz Wool ◽  
Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

Cytokinins from terminal buds of Euphoria longana during different growth stages

1997 ◽  
Vol 99 (1) ◽  
pp. 185-189
Author(s):  
Wen-Shaw Chen ◽  
Kuang-Liang Huang ◽  
Hsiao-Ching Yu
Keyword(s):  
Growth Stages ◽  
Terminal Buds ◽  
Different Growth Stages

Effect of high‐temperature AlN buffer on anisotropy of semi‐polar (11‐22) GaN with two pressure growth stages

2019 ◽  
Vol 14 (9) ◽  
pp. 972-975
Author(s):  
Jun Han ◽  
Fengfeng Shi ◽  
Yanhui Xing ◽  
Peiyuan Wan ◽  
Zhiyuan Gao ◽  
...  
Keyword(s):  
High Temperature ◽  
Growth Stages ◽  
Aln Buffer

A new species of lambdarina (rhynchonellida, brachiopoda) from the viséan of central sudetes (Poland) and its phylogenetic position

2014 ◽  
Vol 64 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Jolanta Muszer
Keyword(s):  
New Species ◽  
Full Range ◽  
Morphological Features ◽  
Phylogenetic Position ◽  
Growth Stages ◽  
Tropical Waters ◽  
Marginal Seas ◽  
Sw Poland ◽  
A New Species

Abstract A new species of micromorphic articulate brachiopod (Rhynchonellida) Lambdarina jugowiensis sp. nov., from the upper Visean (Sokolec Beds) of central Sudetes, SW Poland, is described. The studied specimens are calcified, what makes them unique in respect of their state of preservation. The material is represented by a full range of growth stages; from brephic to gerontic. Based on its morphological features and the palaeogeographical distribution of all its known species, two main evolutionary lines are proposed for the genus; the Australian and the European ones. Lambdarina was widely distributed in the equatorial-tropical waters of marginal seas of the Palaeotethys Ocean, mostly during Mississippian time.

Absorption, Distribution, and Translocation of Nitrogen at Growth Stages in Oilseed Rape Plant

2010 ◽  
Vol 36 (2) ◽  
pp. 321-326
Author(s):  
Zhen-Hua ZHANG ◽  
Hai-Xing SONG ◽  
Qiang LIU ◽  
Xiang-Min RONG ◽  
Gui-Xian XIE ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Growth Stages ◽  
Rape Plant

Effects of Meteorological Factors at Different Growth Stages on Yield Traits of Maize (Zea maysL.) in Heilonggang Basin

2013 ◽  
Vol 39 (5) ◽  
pp. 919 ◽  
Author(s):  
Bo MING ◽  
Jin-Cheng ZHU ◽  
Hong-Bin TAO ◽  
Li-Na XU ◽  
Bu-Qing GUO ◽  
...  
Keyword(s):  
Meteorological Factors ◽  
Growth Stages ◽  
Yield Traits ◽  
Different Growth Stages
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