Temperature effects on embryogenesis in Smittia spec. (Diptera, chironomidae): Q10-values of normal development and frequency of ?double abdomens? after UV irradiation

1971 ◽  
Vol 168 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Klaus Kalthoff
Keyword(s):  
Uv Irradiation ◽  
Temperature Effects ◽  
Normal Development ◽  
Q10 Values

scholarly journals Two UV-sensitive targets in dorsoanterior specification of frog embryos

Development ◽  
1989 ◽  
Vol 106 (3) ◽  
pp. 511-518 ◽  
Author(s):  
R.P. Elinson ◽  
P. Pasceri
Keyword(s):  
Uv Irradiation ◽  
Normal Development ◽  
Lithium Treatment ◽  
Dorsoventral Polarity ◽  
Prophase I ◽  
Uv Dose ◽  
Metaphase I

Previous work has shown that ultraviolet (UV) irradiation of fertilized frog eggs yields embryos that lack dorsal and anterior structures. The eggs fail to undergo the cortical/cytoplasmic rotation that specifies dorsoventral polarity, and they lack an array of parallel microtubules associated with the rotation. These eggs can be rescued by tilting with respect to gravity, and normal dorsoanterior development occurs. We find here that UV irradiation of Xenopus prophase I oocytes or Rana metaphase I oocytes also causes the dorsoanterior deficient syndrome, but the UV target is different from that in fertilized eggs. Tilting eggs, irradiated as oocytes, with respect to gravity, does not rescue dorsoanterior development, although lithium treatment does. The UV dose required to produce dorsoanterior deficiency for Rana metaphase I oocytes is much less than that for fertilized eggs, and the oocytes can form the array of parallel microtubules and undergo the cortical/cytoplasmic rotation after fertilization. Despite these features of normal development, no dorsoanterior structures form. While the UV target in fertilized eggs is thought to be the parallel microtubules (Elinson & Rowning, 1988; Devl Biol. 128, 185–197), the UV target in the oocytes may be a dorsal determinant.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

Electron Microscopy of Silicon Deposits in Foliar Idioblasts of Magnolia Grandiflora

1976 ◽  
Vol 34 ◽  
pp. 374-375
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscopy ◽  
Water Loss ◽  
Normal Development ◽  
Magnolia Grandiflora ◽  
Plant Body ◽  
Normal Metabolism ◽  
Hydrated Oxide

Silicon occurs naturally in plants in the form of its hydrated oxide (SiO2.nH2O) commonly called silica. Silica has been shown to be a necessary element in the normal development of many plants, playing an array of roles including strengthening, protection, and reduction of water loss. Deposition of silica in various portions of the plant body, especially the leaves, may also be viewed as a way for the plant to dispose of any excess silica taken up beyond that necessary for normal metabolism.Studies of this “opaline” silica have thus far been limited to species of the Cyperaceae and Gramineae known to possess significant quantities of silica. Within the Magnoliaceae, certain “glistening” idioblast cells at the foliar veinlet termini and vein sheaths of Magnolia grandiflora (1) have been suspected to be siliceous in nature.

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

Lexical Comprehension in Young Children With Developmental Delays

1994 ◽  
Vol 3 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Theresa A. Kouri
Keyword(s):  
Young Children ◽  
Developmental Delays ◽  
Normal Development ◽  
Clinical Applications ◽  
Group Status ◽  
Novel Object ◽  
Related Information ◽  
Comprehension Skills ◽  
Lexical Items ◽  
Lexical Concepts

Lexical comprehension skills were examined in 20 young children (aged 28–45 months) with developmental delays (DD) and 20 children (aged 19–34 months) with normal development (ND). Each was assigned to either a story-like script condition or a simple ostensive labeling condition in which the names of three novel object and action items were presented over two experimental sessions. During the experimental sessions, receptive knowledge of the lexical items was assessed through a series of target and generalization probes. Results indicated that all children, irrespective of group status, acquired more lexical concepts in the ostensive labeling condition than in the story narrative condition. Overall, both groups acquired more object than action words, although subjects with ND comprehended more action words than subjects with DD. More target than generalization items were also comprehended by both groups. It is concluded that young children’s comprehension of new lexical concepts is facilitated more by a context in which simple ostensive labels accompany the presentation of specific objects and actions than one in which objects and actions are surrounded by thematic and event-related information. Various clinical applications focusing on the lexical training of young children with DD are discussed.

The Animal Models for Hemorrhage and Thrombosis in the Neonate

1987 ◽  
Vol 57 (01) ◽  
pp. 118-122 ◽  
Author(s):  
C Thomas Kisker
Keyword(s):  
Animal Models ◽  
Normal Development ◽  
Relevant Information ◽  
Relevant Model ◽  
Current Information ◽  
Single Animal ◽  
Hemostatic Disorders ◽  
Thrombotic Diseases

SummaryAnimal models have added significantly to our understanding of adult hemorrhagic and thrombotic diseases. Few models, however, have been developed for studies of the hemostatic disorders in the fetus and newborn. This report reviews the current information on animal models of fetal and neonatal hemostasis. The requirements of a relevant model are addressed and previous studies using fetal and neonatal animal models are reviewed. A recommendation of a single animal for all studies of fetal and neonatal hemostasis is not possible. However, the lamb has been the most frequently studied and appears to provide relevant information regarding normal development and the factors which may adversely influence hemostasis in the fetus and newborn.

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