circular structures
Recently Published Documents


TOTAL DOCUMENTS

96
(FIVE YEARS 17)

H-INDEX

15
(FIVE YEARS 1)

Author(s):  
María Camila Romero ◽  
Paola Lara ◽  
Jorge Villalobos

The business is an abstraction of the way in which value is created and delivered. The concrete representation is the business model, expressed by a group of artifacts built with different languages. It serves to describe, explain, analyze, design, and evaluate the business. The set of concepts, construction rules, artifacts, and languages required to express it, are defined by a Meta-Business Model (MBM). Multiple authors have proposed different MBMs, each one with a specific motivation and objective. Some of these MBMs are widely recognized and have been applied in contexts like innovation and entrepreneurship. Due to new challenges, such as sustainability, being faced by businesses and given new ways of producing and delivering value, like the sharing economy, Novel Complex Businesses (NCBs) are emerging. NCBs are businesses characterized by circular structures made out of numerous inter-related components, and by creating value out of the product/service schema. While existing MBMs fulfill certain purposes, they do not have the expressiveness required to describe NCBs precisely enough to describe and analyze them. This paper introduces an MBM with the concepts, construction rules, and graphical notation needed to represent NCBs. We also illustrate an NCB and present the results of the validation for our MBM.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10703 ◽  
Author(s):  
Christian Klug ◽  
Gianpaolo Di Silvestro ◽  
Rene Hoffmann ◽  
Guenter Schweigert ◽  
Dirk Fuchs ◽  
...  

Because of physiology of coleoids, their fossils preserve soft-tissue-remains more often than other cephalopods. Sometimes, the phosphatized soft-tissues, particularly parts of the muscular mantle, display dark circular patterns. Here, we showcase that these patterns, here documented for fossil coleoids from the Jurassic of Germany and the Cretaceous of Lebanon, superficially resemble chromatophores (which enable living coleoids to alter their coloration). We examined and chemically analyzed the circular structures in these specimens, describe them, and discuss their genesis. Based on their structure and color, we visually differentiate between three types of circles. By comparison with similar structures, we suggest that these structures are not biogenic but Liesegang rings, which formed due to reaction-diffusion processes very soon after death.


2020 ◽  
Vol 17 (8) ◽  
pp. 687-697
Author(s):  
Nana Ma ◽  
Wei Zhang ◽  
Jun Wan

Circular RNAs (circRNAs) are a kind of non-coding RNA molecule with highly stable circular structures. CircRNAs are primarily composed of exons and/or introns. Recently, a lot of exciting studies showed that circRNA played an essential role in the development of nervous system diseases. Here, classification, characteristics, biogenesis, and the association of circRNA dysregulation with nervous system diseases, such as Alzheimer’s disease, are summarized. The review not only contributes to a better understanding of circRNAs, but also provides new research directions toward the diagnosis, treatment, and prevention of nervous system diseases.


2020 ◽  
Vol 31 (18) ◽  
pp. 2128-2136
Author(s):  
Shuai Liu ◽  
Qing-Sheng Yang ◽  
Ran Tao

Inspired by the origami, a series of smart circular structures with large folding ratio was designed and fabricated by four-dimensional printing in this article. The structure consists of the crease and plate parts by embedding the Miura-ori into a folding fan, and has the characteristics of bi-stable states and self-deployment by introducing soft and hard shape memory polymers. The shape memory polymer material parameters were obtained by the dynamic-mechanical analyzer, and then the constitutive equation can be determined. To demonstrate the folding and deployment performance of the smart structures, the experiment and finite element simulation was carried out. It is shown that the structures can repeatedly be folded and deployed by temperature-controlled shape memory effect of shape memory polymer. This design can be applied to the large-scale and multiple level smart structures such as antennas and deployable solar sails.


Author(s):  
V. Klochkov ◽  
S. Klochkov

The paper formulates a new vision of the reasons for the formation of the modern structural-geological appearance of the Northern Black Sea and the offshore area of the Azov Sea. The catastrophic events in the Northern Black Sea, during the Permian-Triassic period, about 250 million years ago, allegedly occurred. Giant asteroid exploded (or just collapsed) when it entered the dense layers of the atmosphere, and its multifarious debris formed numerous circular structures on the Northern Black Sea during the fall. It has suggested that this space catastrophe is the forerunner of the famous Permian extinction of the terrestrial biota.  Graphically and descriptively, it has been proved that approximately along the Bataisk-Krasnoperekopsk-Izmail line, according to the RSD, 3 large circular structures and up to 20 small ones are decoded. It is proved – the line corresponds to the Northern suture zone, which separates the East-European platform from the Scythian epiorogenic zone. The suture area has been active for approximately 250 million years. It has been theoretically proved that it is the invasive effect of the cosmic body that is the root cause of the fault zone, which in Cimmeria evolved into the Northern suture zone. Using modern RSD made it possible to identify large circular structures of the Northern Black Sea Region. These are Azov, Bataisk and Kalamitska. Major research interest in the segments of the Azov astrobleme in the context of the oil and gas exploration work is determined. It is proved by retrospective geological information that the identifying structures have a significant depth of occurrence and here the earth’s crust should be saturated with a significant number of supply channels (decompression zones) favorable for hydrocarbon migration.


2020 ◽  
Author(s):  
Chiara Merigliano ◽  
Romina Burla ◽  
Mattia La Torre ◽  
Simona Del Giudice ◽  
Hsiang Ling Teo ◽  
...  

AbstractTo complete mitosis, the intercellular bridge that links daughter cells needs to be cleaved. This abscission step is carried out by the sequential recruitment of ESCRT proteins at the midbody. We report here that a new factor, named AKTIP, works in association with ESCRTs. We find that AKTIP binds to the ESCRT I subunit VPS28, and show by high resolution microscopy that AKTIP forms a ring in the dark zone of the intercellular bridge. This ring is positioned in between the circular structures formed by ESCRTs type III. Functionally, we observe that the reduction of AKTIP impinges on the recruitment of the ESCRT III member IST1 at the midbody and causes abscission defects. Taken together, these data indicate that AKTIP is a new factor that contributes to the formation of the ESCRT complex at the midbody and is implicated in the performance of the ESCRT machinery during cytokinetic abscission.


Sign in / Sign up

Export Citation Format

Share Document