Middleware-level collaborative resource discovery for large clusters

2005 ◽  
Author(s):  
J. Al-Jaroodi ◽  
N. Mohamed
Keyword(s):  
Resource Discovery ◽  
Large Clusters

Chromospheric activity as a function of age in main-sequence stars

1966 ◽  
Vol 24 ◽  
pp. 40-43
Author(s):  
O. C. Wilson ◽  
A. Skumanich
Keyword(s):  
Main Sequence ◽  
The Sun ◽  
Main Sequence Stars ◽  
Tentative Conclusion ◽  
Chromospheric Activity ◽  
General Field ◽  
Large Clusters

Evidence previously presented by one of the authors (1) suggests strongly that chromospheric activity decreases with age in main sequence stars. This tentative conclusion rests principally upon a comparison of the members of large clusters (Hyades, Praesepe, Pleiades) with non-cluster objects in the general field, including the Sun. It is at least conceivable, however, that cluster and non-cluster stars might differ in some fundamental fashion which could influence the degree of chromospheric activity, and that the observed differences in chromospheric activity would then be attributable to the circumstances of stellar origin rather than to age.

Triple Fixation For Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 90-91 ◽  
Author(s):  
M. A. Hayat
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Plasma Membrane ◽  
Myelin Sheath ◽  
Good Deal ◽  
Granular Structure ◽  
Oxidizing Agent ◽  
Fixation Technique ◽  
Large Clusters

Potassium permanganate has been successfully employed to study membranous structures such as endoplasmic reticulum, Golgi, plastids, plasma membrane and myelin sheath. Since KMnO4 is a strong oxidizing agent, deposition of manganese or its oxides account for some of the observed contrast in the lipoprotein membranes, but a good deal of it is due to the removal of background proteins either by dehydration agents or by volatalization under the electron beam. Tissues fixed with KMnO4 exhibit somewhat granular structure because of the deposition of large clusters of stain molecules. The gross arrangement of membranes can also be modified. Since the aim of a good fixation technique is to preserve satisfactorily the cell as a whole and not the best preservation of only a small part of it, a combination of a mixture of glutaraldehyde and acrolein to obtain general preservation and KMnO4 to enhance contrast was employed to fix plant embryos, green algae and fungi.

The interaction of a manganese-oxidising bacterium as part of a biofilm growing on distribution pipe materials

2000 ◽  
Vol 41 (4-5) ◽  
pp. 295-300 ◽  
Author(s):  
F. Murdoch ◽  
P.G. Smith
Keyword(s):  
Biofilm Formation ◽  
Bacterial Activity ◽  
Confocal Laser ◽  
Pipe Surface ◽  
X Ray ◽  
Pseudomonas Spp ◽  
Eds Analysis ◽  
Large Clusters ◽  
Pipe Materials ◽  
Confocal Laser Microscope

The deposition of manganese within a biofilm growing on the surface of high-density polyethlene (HDPE) and polyvinychloride (PVC) was studied over a period of four months. The manganese rich water used in the study was inoculated with a manganese oxidising Pseudomonas spp. The level of Mn2+ in the water was monitored and was found to decrease as the biofilm formation increased. This was confirmed by energy dispersive X-ray spectroscopy (EDS) analysis which showed the detection of manganese was dependent on the presence of a biofilm. After two months a 100% removal of Mn2+ was observed in all the flasks inoculated by the Pseudomonas spp. and manganese micro-nodules, the formation of which were reported in Murdoch and Smith (1999), were being formed in large clusters across the surfaces of both the HDPE and PVC. The manganese peak area from the EDS spectrum analysis of the micro-nodules was significantly larger than was measured in the biofilm when these micro-nodules were absent. The scanning confocal laser microscope (SCLM) images of three-week samples showed high bacterial activity around areas where manganese micro-nodules were starting to form on the pipe surface.

TEACH THE EARTH’S DECENTRALIZED MODEL FOR CENTRALIZED EDUCATIONAL RESOURCE DISCOVERY

2016 ◽  
Author(s):  
Rory R. McFadden ◽  
◽  
Sean P. Fox ◽  
Sean P. Fox ◽  
Cathryn A. Manduca ◽  
...  
Keyword(s):  
Resource Discovery ◽  
Educational Resource ◽  
Decentralized Model

scholarly journals User-driven efforts in creating knowledge graph information system

2020 ◽  
Vol 36 (2) ◽  
pp. 97-111
Author(s):  
Stanislava Gardasevic
Keyword(s):  
Information System ◽  
Information Seeking ◽  
Information Needs ◽  
Resource Discovery ◽  
The Body ◽  
Knowledge Graph ◽  
Structured Interviews ◽  
Community Members ◽  
Study Objective ◽  
Content Type

Purpose This paper presents the results of a qualitative study that involved students of an interdisciplinary PhD program. The study objective was to gather requirements to create a knowledge graph information system. The purpose of this study was to determine information-seeking practices and information needs of this community, to inform the functionalities of a proposed system, intended to help students with relevant resource discovery and decision-making. Design/methodology/approach The study design included semi-structured interviews with eight members of the community, followed by a website usability study with the same student participants. Findings Two main information-seeking styles are recognized and reported through user personas of international and domestic (USA) students. The findings show that the useful information resides within the community and not so much on the program website. Students rely on peer communication, although they report lack of opportunities to connect. Students’ information needs and information seeking are dependent on their progress through the program, as well as their motivation and the projected timeline. Practical implications Considering the current information needs and practices, a knowledge graph hosting both information on social networks and the knowledge produced by the activities of the community members would be useful. By recording data on their activities (for example, collaboration with professors and coursework), students would reveal further useful system functionalities and facilitate transfer of tacit knowledge. Originality/value Aside from the practical value of this research that is directly influencing the design of a system, it contributes to the body of knowledge on interdisciplinary PhD programs.

scholarly journals EphA2 super-enhancer promotes tumor progression by recruiting FOSL2 and TCF7L2 to activate the target gene EphA2

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Shuang Cui ◽  
Qiong Wu ◽  
Ming Liu ◽  
Mu Su ◽  
ShiYou Liu ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Tumor Cells ◽  
Target Gene ◽  
Super Enhancer ◽  
Proliferation And Metastasis ◽  
Active Transcription ◽  
Hct 116 ◽  
Large Clusters

AbstractSuper-enhancers or stretch enhancers (SEs) consist of large clusters of active transcription enhancers which promote the expression of critical genes that define cell identity during development and disease. However, the role of many super-enhancers in tumor cells remains unclear. This study aims to explore the function and mechanism of a new super-enhancer in various tumor cells. A new super-enhancer that exists in a variety of tumors named EphA2-Super-enhancer (EphA2-SE) was found using multiple databases and further identified. CRISPR/Cas9-mediated deletion of EphA2-SE results in the significant downregulation of its target gene EphA2. Mechanistically, we revealed that the core active region of EphA2-SE comprises E1 component enhancer, which recruits TCF7L2 and FOSL2 transcription factors to drive the expression of EphA2, induce cell proliferation and metastasis. Bioinformatics analysis of RNA-seq data and functional experiments in vitro illustrated that EphA2-SE deletion inhibited cell growth and metastasis by blocking PI3K/AKT and Wnt/β-catenin pathway in HeLa, HCT-116 and MCF-7 cells. Overexpression of EphA2 in EphA2-SE−/− clones rescued the effect of EphA2-SE deletion on proliferation and metastasis. Subsequent xenograft animal model revealed that EphA2-SE deletion suppressed tumor proliferation and survival in vivo. Taken together, these findings demonstrate that EphA2-SE plays an oncogenic role and promotes tumor progression in various tumors by recruiting FOSL2 and TCF7L2 to drive the expression of oncogene EphA2.

scholarly journals On the scaling of fragmentation and energy dissipation in collisions of dust aggregates

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Philipp Umstätter ◽  
Herbert M. Urbassek
Keyword(s):  
Energy Dissipation ◽  
Collision Energy ◽  
Velocity Range ◽  
Collision Velocity ◽  
Granular Mechanics ◽  
Extra Factor ◽  
Cluster Fragmentation ◽  
Silica Clusters ◽  
Large Clusters ◽  
Small Clusters

Abstract Fragmentation of granular clusters may be studied by experiments and by granular mechanics simulation. When comparing results, it is often assumed that results can be compared when scaled to the same value of $$E/E_{\mathrm{sep}}$$ E / E sep , where E denotes the collision energy and $$E_{\mathrm{sep}}$$ E sep is the energy needed to break every contact in the granular clusters. The ratio $$E/E_{\mathrm{sep}}\propto v^2$$ E / E sep ∝ v 2 depends on the collision velocity v but not on the number of grains per cluster, N. We test this hypothesis using granular-mechanics simulations on silica clusters containing a few thousand grains in the velocity range where fragmentation starts. We find that a good parameter to compare different systems is given by $$E/(N^{\alpha }E_{\mathrm{sep}})$$ E / ( N α E sep ) , where $$\alpha \sim 2/3$$ α ∼ 2 / 3 . The occurrence of the extra factor $$N^{\alpha }$$ N α is caused by energy dissipation during the collision such that large clusters request a higher impact energy for reaching the same level of fragmentation than small clusters. Energy is dissipated during the collision mainly by normal and tangential (sliding) forces between grains. For large values of the viscoelastic friction parameter, we find smaller cluster fragmentation, since fragment velocities are smaller and allow for fragment recombination. Graphic abstract

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