Tubulin polymerization in unfertilized sea-urchin eggs induced by elevated temperature

1989 ◽  
Vol 93 (1) ◽  
pp. 9-17
Author(s):  
P.J. Harris ◽  
E.L. Clason ◽  
K.R. Prier
Keyword(s):  
Elevated Temperature ◽  
Sea Urchins ◽  
Fine Crystal ◽  
Lytechinus Pictus ◽  
Spontaneous Polymerization ◽  
Rate Of Polymerization ◽  
Normal Environment ◽  
Long Term Observation ◽  
Order Structures

Spontaneous polymerization of tubulin was induced in unfertilized eggs of the sea urchins Lytechinus pictus and Strongylocentrotus purpuratus by warming to temperatures 10–12 deg. C above the normal environment for each species. Indirect immunofluorescence microscopy showed that over a period of several hours polymerization proceeded from a fine crystal-like precipitate to larger and fewer higher-order structures. These structures differed morphologically between the two species: L. pictus formed cytasters, while S. purpuratus most often formed flame-like arrays. Nuclear cycles were not initiated, permitting long-term observation of steady-state polymer redistribution. After several hours only a few very large cytasters remained near the surface of L. pictus eggs and these tended to constrict to form protrusions or occasionally a cleavage furrow that divided the egg into two fragments. Staining with rhodamine-labeled phalloidin showed that actin was also concentrated in the cytasters, primarily at the periphery of the centrosphere-like regions. L. pictus cytasters could be recycled by repeated cooling and rewarming, and showed an accelerated rate of polymerization with each successive cycle. Cytasters could also be isolated as long as the initial procedures were carried out at the elevated temperature. Washed preparations were stable at room temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effects of long-term elevated temperature on covering, sheltering and righting behaviors of the sea urchinStrongylocentrotus intermedius

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3122 ◽  
Author(s):  
Lisheng Zhang ◽  
Lingling Zhang ◽  
Dongtao Shi ◽  
Jing Wei ◽  
Yaqing Chang ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Behavioral Responses ◽  
Ambient Water ◽  
Righting Response ◽  
New Information ◽  
Ambient Water Temperature ◽  
Local Ecosystem

Increases in ocean temperature due to climate change are predicted to change the behaviors of marine invertebrates. Altered behaviors of keystone ecosystem engineers such as echinoderms will have consequences for the fitness of individuals, which are expected to flow on to the local ecosystem. Relatively few studies have investigated the behavioral responses of echinoderms to long-term elevated temperature. We investigated the effects of exposure to long-term (∼31 weeks) elevated temperature (∼3 °C above the ambient water temperature) on covering, sheltering and righting behaviors of the sea urchinStrongylocentrotus intermedius. Long-term elevated temperature showed different effects on the three behaviors. It significantly decreased covering behavior, including both covering behavior reaction (time to first covering) and ability (number of covered sea urchins and number of shells used for covering). Conversely, exposure to long-term elevated temperature significantly increased sheltering behavior. Righting response inS. intermediuswas not significantly different between temperature treatments. The results provide new information into behavioral responses of echinoderms to ocean warming.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

Analysis of crystallite size changes in a hematite and magnetite formed on steel used in the power idustry

2017 ◽  
Vol 1 (21) ◽  
pp. 65-73
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Cross Section ◽  
X Ray ◽  
Term Operation ◽  
Diffraction Line Profile ◽  
Crystallite Sizes ◽  
Scherrer Formula ◽  
Pipe Outlet

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.

scholarly journals SAT0137 Long-term observation of fibromyalgia patients

2001 ◽  
Author(s):  
L Szczepanski ◽  
C Stepniak ◽  
B Targonska-Stepniak
Keyword(s):  
Long Term Observation

scholarly journals Phenotype of the Aging-Dependent Spontaneous Onset of Hearing Loss in DBA/2 Mice

2021 ◽  
Vol 8 (3) ◽  
pp. 49
Author(s):  
Min-Soo Seo ◽  
Byeonghyeon Lee ◽  
Kyung-Ku Kang ◽  
Soo-Eun Sung ◽  
Joo-Hee Choi ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Early Stage ◽  
Auditory Brainstem ◽  
Dependent Manner ◽  
Intrinsic Properties ◽  
Hearing Ability ◽  
Brainstem Response ◽  
Long Term Observation ◽  
Spontaneous Onset

DBA/2 mice are a well-known animal model for hearing loss developed due to intrinsic properties of these animals. However, results on the phenotype of hearing loss in DBA/2 mice have been mainly reported at an early stage in mice aged ≤7 weeks. Instead, the present study evaluated the hearing ability at 5, 13, and 34 weeks of age using DBA/2korl mice. Auditory brainstem response test was performed at 8–32 KHz at 5, 13, and 34 weeks of age, and hearing loss was confirmed to be induced in a time-dependent manner. In addition, histopathological evaluation at the same age confirmed the morphological damage of the cochlea. The findings presented herein are the results of the long-term observation of the phenotype of hearing loss in DBA/2 mice and can be useful in studies related to aging-dependent hearing loss.

scholarly journals Posterior Uveal Effusion after Cataract Surgery

2021 ◽  
pp. 62-67
Author(s):  
Annegret Abaza ◽  
Özlem Dikmetas ◽  
Irmingard Neuhann ◽  
Faik Gelisken
Keyword(s):  
Cataract Surgery ◽  
Corticosteroid Therapy ◽  
Anterior Segment ◽  
Subretinal Fluid ◽  
Posterior Pole ◽  
Functional Improvement ◽  
Long Term Observation ◽  
The Right ◽  
Uveal Effusion

We report a case of posterior uveal effusion (UE) with a long-term follow-up that has occurred following cataract surgery. A 64-year-old woman presented with diminished vision of the right eye (RE) 3 weeks after an uneventful phacoemulsification and intraocular lens implantation. Complete ophthalmic examination including fluorescein angiography (FA), indocyanine green angiography (ICGA), echography and optical coherence tomography (OCT) were performed. Best corrected visual acuity (BCVA) of the RE was 20/50. Anterior segment and intraocular pressure were unremarkable. OCT revealed prominent folds of the choroid and retina, subretinal fluid and darkening of the choroid with reduced visibility of the choroidal vessels and the scleral border. The left eye (LE) was unremarkable. BCVA of the LE was: 20/20. After topical anti-inflammatory and systemic corticosteroid therapy for 5 months, no morphological change of the macula was seen. The patient was observed without any treatment. Forty-three months after the cataract surgery and 38 months after cessation of the corticosteroid therapy, OCT revealed a normal macular morphology and the BCVA improved to 20/25. Even though rare, UE at the posterior pole may occur after modern cataract surgery. OCT examination is a reliable tool in monitoring the macular morphology. Since morphological and functional improvement can be seen in long-term, observation may be considered for some cases of posterior UE with resistance to the therapy.

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