scholarly journals Large-scale death of retinal astrocytes during normal development is non-apoptotic and implemented by microglia

PLoS Biology ◽  
2019 ◽  
Vol 17 (10) ◽  
pp. e3000492 ◽  
Author(s):  
Vanessa M. Puñal ◽  
Caitlin E. Paisley ◽  
Federica S. Brecha ◽  
Monica A. Lee ◽  
Robin M. Perelli ◽  
...  
Keyword(s):  
Large Scale ◽  
Normal Development ◽  
Retinal Astrocytes

scholarly journals Large-scale death of retinal astrocytes during normal development mediated by microglia

2019 ◽  
Author(s):  
Vanessa M. Puñal ◽  
Caitlin E. Paisley ◽  
Federica S. Brecha ◽  
Monica A. Lee ◽  
Robin M. Perelli ◽  
...  
Keyword(s):  
Cell Death ◽  
Large Scale ◽  
Normal Development ◽  
Retinal Hemorrhage ◽  
Genetic Ablation ◽  
Retinal Astrocytes ◽  
Naturally Occurring ◽  
Major Cell Type ◽  
The Central Nervous System ◽  
Developmental Cell Death

Naturally-occurring cell death is a fundamental developmental mechanism for regulating cell numbers and sculpting developing organs. This is particularly true in the central nervous system, where large numbers of neurons and oligodendrocytes are eliminated via apoptosis during normal development. Given the profound impact of death upon these two major cell populations, it is surprising that developmental death of another major cell type – the astrocyte – has rarely been studied. It is presently unclear whether astrocytes are subject to significant amounts of developmental death, or how it occurs. Here we address these questions using mouse retinal astrocytes as our model system. We show that the total number of retinal astrocytes declines by over 3-fold during a death period spanning postnatal days 5-14. Surprisingly, these astrocytes do not die by apoptosis, the canonical mechanism underlying the vast majority of developmental cell death. Instead, we find that microglia kill and engulf astrocytes to mediate their developmental removal. Genetic ablation of microglia inhibits astrocyte death, leading to a larger astrocyte population size at the end of the death period. However, astrocyte death is not completely blocked in the absence of microglia, apparently due to the ability of astrocytes to engulf each other. Nevertheless, mice lacking microglia showed significant anatomical changes to the retinal astrocyte network, with functional consequences for the astrocyte-associated vasculature leading to retinal hemorrhage. These results establish a novel modality for naturally-occurring cell death, and demonstrate its importance for formation and integrity of the retinal gliovascular network.

Influence of medical epidemic prevention and control on the development of sports events based on FPGA system and machine learning

2021 ◽  
pp. 1-13
Author(s):  
Wu Jing
Keyword(s):  
Machine Learning ◽  
Prevention And Control ◽  
Large Scale ◽  
Normal Development ◽  
Basic Knowledge ◽  
Chinese Government ◽  
Relevant Model ◽  
Sports Events ◽  
Specific Scheme ◽  
And Control

In year 2020, a large-scale outbreak of pneumonia caused by new coronavirus has affected the development of many industries and enterprises in China. Under the strong leadership of the Chinese government, the development of the epidemic situation in China has been well controlled. The development of various industries also began to show a good situation, many large-scale sports competitions also need to be restored. In order to ensure the normal development of large-scale sports events, we need to consider the development of epidemic situation to determine the time of sports events. Based on the study of FPGA theory, this paper designs a specific scheme of programming and system debugging, which includes a variety of program operations. In order to better predict the situation of the epidemic situation, this paper also uses the basic knowledge of machine learning to establish a relevant model to evaluate the situation of large-scale sports events under the development of the epidemic situation, and provide feasible suggestions for the recovery of large-scale sports events under the epidemic situation.

“Physiological genomics”: mutant screens in zebrafish

1998 ◽  
Vol 275 (1) ◽  
pp. H1-H7 ◽  
Author(s):  
Kerri S. Warren ◽  
Mark C. Fishman
Keyword(s):  
Cardiovascular System ◽  
Danio Rerio ◽  
Large Scale ◽  
Normal Development ◽  
Single Gene ◽  
Gene Mutations ◽  
Genetic System ◽  
Developing Heart ◽  
Developmental Physiology ◽  
Large Scale Screening

Large-scale mutagenesis screens have proved essential in the search for genes that are important to development in the fly, worm, and yeast. Here we present the power of large-scale screening in a vertebrate, the zebrafish Danio rerio, and propose the use of this genetic system to address fundamental questions of vertebrate developmental physiology. As an example, we focus on zebrafish mutations that reveal single genes essential for normal development of the cardiovascular system. These single gene mutations disrupt specific aspects of rate, rhythm, conduction, or contractility of the developing heart.

scholarly journals Mutations affecting development of the notochord in zebrafish

Development ◽  
1996 ◽  
Vol 123 (1) ◽  
pp. 117-128 ◽  
Author(s):  
D.L. Stemple ◽  
L. Solnica-Krezel ◽  
F. Zwartkruis ◽  
S.C. Neuhauss ◽  
A.F. Schier ◽  
...  
Keyword(s):  
Large Scale ◽  
Normal Development ◽  
Paraxial Mesoderm ◽  
Skeletal Element ◽  
Additional Insight ◽  
Genetic Pathway ◽  
Complementation Groups ◽  
Vertebrate Embryos ◽  
Insight Into

The notochord is critical for the normal development of vertebrate embryos. It serves both as the major skeletal element of the embryo and as a signaling source for the establishment of pattern within the neurectoderm, the paraxial mesoderm and other tissues. In a large-scale systematic screen of mutations affecting embryogenesis in zebrafish we identified 65 mutations that fall into 29 complementation groups, each leading to a defect in the formation and/or maintenance of the notochord. These mutations produce phenotypic abnormalities at numerous stages of notochord development, thereby establishing a phenotypic pathway, which in turn suggests a genetic pathway for the development of the notochord. Perturbations within adjacent tissues in mutant embryos further indicate the importance of notochord-derived signals for patterning within the embryo and suggest that these mutations will yield additional insight into the cues that regulate these patterning processes.

scholarly journals Molecular mechanisms of experience-dependent plasticity in visual cortex

2008 ◽  
Vol 364 (1515) ◽  
pp. 341-355 ◽  
Author(s):  
Daniela Tropea ◽  
Audra Van Wart ◽  
Mriganka Sur
Keyword(s):  
Visual Cortex ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Normal Development ◽  
Current Knowledge ◽  
Feedback Regulation ◽  
Dependent Plasticity ◽  
Genetic Manipulations ◽  
Pathological Conditions ◽  
The Central Nervous System

A remarkable amount of our current knowledge of mechanisms underlying experience-dependent plasticity during cortical development comes from study of the mammalian visual cortex. Recent advances in high-resolution cellular imaging, combined with genetic manipulations in mice, novel fluorescent recombinant probes, and large-scale screens of gene expression, have revealed multiple molecular mechanisms that underlie structural and functional plasticity in visual cortex. We situate these mechanisms in the context of a new conceptual framework of feed-forward and feedback regulation for understanding how neurons of the visual cortex reorganize their connections in response to changes in sensory inputs. Such conceptual advances have important implications for understanding not only normal development but also pathological conditions that afflict the central nervous system.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

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.

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