The Mechanism of Hardening of the Salmonid Egg Membrane after Fertilization or Spontaneous Activation

Development ◽  
1958 ◽  
Vol 6 (4) ◽  
pp. 546-568
Author(s):  
A. I. Zotin
Keyword(s):  
Mechanical Property ◽  
Embryonic Development ◽  
Mechanical Damage ◽  
Mechanical Injury ◽  
External Factors ◽  
Salmonid Fishes ◽  
Egg Membrane ◽  
Spontaneous Activation

The embryonic development of fishes proceeds under the protection of rigid egg membranes which preserve the embryo from mechanical injury. Salmonid fishes bury their eggs in sandy and stony ground so that they are particularly liable to mechanical damage. This is apparently the reason why the membrane of the salmonid embryo is extremely strong, resisting a load of 3–4 kg. per ovum (Gray, 1932; Hayes, 1942, 1949; Hayes & Armstrong, 1942; Zotin, 1953a). This mechanical property of the membrane does not appear immediately after fertilization or activation but is preceded by a whole set of processes which are elicited in the membrane by external factors and by the fertilized or activated egg itself. Thus, according to Manery, Fisher, & Moore (1947), hardening of the egg membranes in the speckled trout sets in 2 hours after the release of the egg into water.

The embryonic development of the swimming behavior of Daphnia pulex (Crustacea: Cladocera)

1972 ◽  
Vol 50 (7) ◽  
pp. 969-973 ◽  
Author(s):  
Michael Berrill ◽  
Colin Henderson
Keyword(s):  
Embryonic Development ◽  
Daphnia Pulex ◽  
Swimming Behavior ◽  
Egg Membrane ◽  
First Time

The embryo of Daphnia pulex sheds two egg membranes and then molts once before completing its development. The second antennae, used for swimming by the fully developed individual, move for the first time shortly before the shedding of the second egg membrane. These antennal movements occur in bouts which appear to be pseudo-rhythmic in organization. The antennae are not raised to their swimming positions until several hours before the molt which terminates embryonic development, at which time they become increasingly active. The onset and subsequent elaboration of antennal activity is therefore closely correlated with the shedding of embryonic membranes.

Inter-specific Transfers of Eggs Between Rat and Mouse

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 476-495
Author(s):  
Andrzej K. Tarkowski
Keyword(s):  
Embryonic Development ◽  
Early Development ◽  
External Factors ◽  
Available Information ◽  
Mammalian Eggs

Inter-Specific transplantations of mammalian eggs offer one possible way of studying the significance of intrinsic and external factors in embryonic development and their mutual interactions. The variety of problems which can be attacked by this method is dependent, of course, on the length of time during which development can proceed with a given combination of donor and recipient. The development of an egg in a specifically foreign animal can be adversely affected from the very beginning, though this is more likely to occur from the time of implantation onwards when all morphological, physiological,, and immunological differences between the embryo and the mother come to action. The available information, though very scanty, supports the view that during early development up to the formation of the blastocyst, the egg is highly tolerant of a foreign environment.

Posttraumatic Dissecting Aneurysm of the Anterior Cerebral Artery: Case Report

Neurosurgery ◽  
1988 ◽  
Vol 23 (2) ◽  
pp. 221-225 ◽  
Author(s):  
Masaharu Amagasa ◽  
So Sato ◽  
Kazunori Otabe
Keyword(s):  
Case Report ◽  
Head Injury ◽  
Corpus Callosum ◽  
Cerebral Infarction ◽  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Mechanical Damage ◽  
Dissecting Aneurysm ◽  
Mechanical Injury ◽  
A Minor

ABSTRACT A case of cerebral infarction in the territory of the anterior cerebral artery after a minor head injury is reported. It is possible that direct or mechanical damage by the edge of the falx or stretching and shearing of the anterior cerebral artery after an acute shift of the corpus callosum caused the localized lesion of the left anterior cerebral artery. We think that this mechanical injury caused a dissecting aneurysm or a cerebral arterial dissection, which was diagnosed by sequential angiographic changes.

scholarly journals Conventional PKCs regulate the temporal pattern of Ca2+ oscillations at fertilization in mouse eggs

2004 ◽  
Vol 164 (7) ◽  
pp. 1033-1044 ◽  
Author(s):  
Guillaume Halet ◽  
Richard Tunwell ◽  
Scott J. Parkinson ◽  
John Carroll
Keyword(s):  
Embryonic Development ◽  
Temporal Pattern ◽  
Physiological Function ◽  
Egg Activation ◽  
Present Evidence ◽  
Downstream Effectors ◽  
Living Mouse ◽  
Egg Membrane ◽  
Mammalian Eggs ◽  
Mouse Eggs

In mammalian eggs, sperm-induced Ca2+ oscillations at fertilization are the primary trigger for egg activation and initiation of embryonic development. Identifying the downstream effectors that decode this unique Ca2+ signal is essential to understand how the transition from egg to embryo is coordinated. Here, we investigated whether conventional PKCs (cPKCs) can decode Ca2+ oscillations at fertilization. By monitoring the dynamics of GFP-labeled PKCα and PKCγ in living mouse eggs, we demonstrate that cPKCs translocate to the egg membrane at fertilization following a pattern that is shaped by the amplitude, duration, and frequency of the Ca2+ transients. In addition, we show that cPKC translocation is driven by the C2 domain when Ca2+ concentration reaches 1–3 μM. Finally, we present evidence that one physiological function of activated cPKCs in fertilized eggs is to sustain long-lasting Ca2+ oscillations, presumably via the regulation of store-operated Ca2+ entry.

scholarly journals Effects of mechanical injury and insect feeding on volatiles emitted by wheat plants

2019 ◽  
Vol 21 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Dariusz Piesik ◽  
Anna Wenda-Piesik ◽  
Robert Lamparski ◽  
Piotr Tabaka ◽  
Tomasz Ligor ◽  
...  
Keyword(s):  
Mechanical Damage ◽  
Green Leaf Volatiles ◽  
Mechanical Injury ◽  
Green Leaf ◽  
Insect Feeding ◽  
Volatile Emission ◽  
Leaf Volatiles ◽  
Hexenyl Acetate ◽  
Oulema Melanopus ◽  
Low Concentrations

We report on changes in the volatiles emitted by wheat plants of the cultivar ‘Tonacja’ after the plants were scraped, pierced or damaged by adults of Oulema melanopus (Linnaeus). The blend of volatiles was dominated by typical green leaf volatiles and in addition contained linalool and B-caryophyllene, but the latter two were released in large amounts only after more than one day of insect feeding. Overall, the plants that had been damaged by the insect released more odors than the plants that were subjected to mechanical damage. Moreover, control plants released significantly lower amounts of volatiles. Scraping of leaves induced higher volatile emission than puncturing the leaves. A Y-tube bioassay was used to evaluate upwind orientation ofadult cereal leafbeetles. Greater number of female 0. melanopus was attracted to (Z)-3-hexenal and (Z)-3 -hexenyl acetate at low concentrations. Higher concentration of these compounds and linalool significantly repelled both females and males.

scholarly journals Mechanical Injury during Postharvest Handling of `Solo' Papaya Fruit

1993 ◽  
Vol 118 (5) ◽  
pp. 618-622 ◽  
Author(s):  
Maria Eloisa G. Quintana ◽  
Robert E. Paull
Keyword(s):  
Heat Treatment ◽  
Core Temperature ◽  
Steel Plate ◽  
Mechanical Damage ◽  
Mechanical Injury ◽  
Skin Injury ◽  
Handling System ◽  
Fruit Samples ◽  
Postharvest Handling ◽  
Impact Injury

`Solo' papaya (Carica papaya L.) fruit removed at different points from a commercial packing house showed that skin injury due to mechanical damage increased as fruit moved through the handling system. The occurrence of “green islands” -areas of skin that remain green and sunken when the fruit was fully ripe-apparently were induced by mechanical injury. Skin injury was seen in fruit samples in contact with the sides of field bins, but not in fruit taken from the center of the bins. Bruise-free fruit at different stages of ripeness (5% to 50% yellow) were dropped from heights of 0 to 100 cm onto a smooth steel plate to simulate drops and injury incurred during commercial handling. No skin injury occurred, although riper fruit showed internal injury when dropped from higher than 75 cm. Fruit (10% to 15% yellow) dropped onto sandpaper from a height of 10 cm had skin injury symptoms similar to those seen on fruit from the commercial handling system. These results suggest that abrasion and puncture injury were more important than impact injury for papaya fruit. Heating fruit at 48C for ≈6 hours or until fruit core temperature (FCT) reached 47.5C aggravated the severity of skin injury. Delays in the application of heat treatment from dropping did not reduce the severity of skin injury significantly, except for fruit heated 24 hours after dropping. Waxing fruit alleviated the severity of skin injury, whether applied before or after the heat treatment. Skin injury to papaya was caused by abrasion and puncture damage-not impact-and increased during postharvest handling of the fruit. The injury was associated mainly with fruit hitting the walls of wooden bins-bin liners may reduce this injury.

Thermomechanical Treatment of a 4340 Ni-Cr-Mo Alloy Steel

1981 ◽  
Vol 39 ◽  
pp. 314-315 ◽  
Author(s):  
M.T. Jahn ◽  
J.C. Yang ◽  
C.M. Wan
Keyword(s):  
Mechanical Property ◽  
Chemical Composition ◽  
Alloy Steel ◽  
Thermomechanical Treatment ◽  
Room Temperature ◽  
Good Combination ◽  
Thermal Treatments ◽  
Low Carbon ◽  
4340 Steel ◽  
Good Improvement

4340 Ni-Cr-Mo alloy steel is widely used due to its good combination of strength and toughness. The mechanical property of 4340 steel can be improved by various thermal treatments. The influence of thermomechanical treatment (TMT) has been studied in a low carbon Ni-Cr-Mo steel having chemical composition closed to 4340 steel. TMT of 4340 steel is rarely examined up to now. In this study we obtain good improvement on the mechanical property of 4340 steel by TMT. The mechanism is explained in terms of TEM microstructures4340 (0.39C-1.81Ni-0.93Cr-0.26Mo) steel was austenitized at 950°C for 30 minutes. The TMTed specimen (T) was obtained by forging the specimen continuously as the temperature of the specimen was decreasing from 950°C to 600°C followed by oil quenching to room temperature. The thickness reduction ratio by forging is 40%. The conventional specimen (C) was obtained by quenching the specimen directly into room temperature oil after austenitized at 950°C for 30 minutes. All quenched specimens (T and C) were then tempered at 450, 500, 550, 600 or 650°C for four hours respectively.

Live Confocal Analysis of Fertilization and Early Development

2001 ◽  
Vol 7 (S2) ◽  
pp. 1012-1013
Author(s):  
Uyen Tram ◽  
William Sullivan
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
Real Time ◽  
Early Development ◽  
Fluorescent Probes ◽  
Primary Defect ◽  
Fluorescent Analysis ◽  
Dynamic Event ◽  
Enormous Amount ◽  
Fluorescent Studies

Embryonic development is a dynamic event and is best studied in live animals in real time. Much of our knowledge of the early events of embryogenesis, however, comes from immunofluourescent analysis of fixed embryos. While these studies provide an enormous amount of information about the organization of different structures during development, they can give only a static glimpse of a very dynamic event. More recently real-time fluorescent studies of living embryos have become much more routine and have given new insights to how different structures and organelles (chromosomes, centrosomes, cytoskeleton, etc.) are coordinately regulated. This is in large part due to the development of commercially available fluorescent probes, GFP technology, and newly developed sensitive fluorescent microscopes. For example, live confocal fluorescent analysis proved essential in determining the primary defect in mutations that disrupt early nuclear divisions in Drosophila melanogaster. For organisms in which GPF transgenics is not available, fluorescent probes that label DNA, microtubules, and actin are available for microinjection.

Interactive Experience and Identification as Predictors of Attributing Responsibility in Video Games

2018 ◽  
Vol 30 (1) ◽  
pp. 3-15
Author(s):  
Nathan Walter ◽  
Yariv Tsfati
Keyword(s):  
Video Game ◽  
Psychological Research ◽  
External Factors ◽  
Theoretical Expectation ◽  
Main Character ◽  
Attribution Of Responsibility ◽  
Attributions Of Responsibility ◽  
Violent Video Game ◽  
Grand Theft Auto Iv ◽  
Interactive Experience

Abstract. This study examines the effect of interactivity on the attribution of responsibility for the character’s actions in a violent video game. Through an experiment, we tested the hypothesis that identification with the main character in Grand Theft Auto IV mediates the effect of interactivity on attributions of responsibility for the main character’s antisocial behavior. Using the framework of the fundamental attribution error, we demonstrated that those who actually played the game, as opposed to those who simply watched someone else playing it, identified with the main character. In accordance with the theoretical expectation, those who played the game and came to identify with the main character attributed the responsibility for his actions to external factors such as “living in a violent society.” By contrast, those who did not interact with the game attributed responsibility for the character’s actions to his personality traits. These findings could be viewed as contrasting with psychological research suggesting that respondents should have distanced themselves from the violent protagonist rather than identifying with him, and with Iyengar’s (1991) expectation that more personalized episodic framing would be associated with attributing responsibility to the protagonist.

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