scholarly journals Background free tracking of single RNA in living cells using catalytically inactive CasE

2019 ◽  
Author(s):  
Feng Gao ◽  
Yue Sun ◽  
Feng Jiang ◽  
Xiaoyue Bai ◽  
Chunyu Han

AbstractRNAs have important and diverse functions. Visualizing an isolated RNA in living cells provide us essential information of its roles. By now, there are two kinds of live RNA imaging systems invented, one is the MS2 system and the other is the Cas13a system. In this study, we show that when fused with split-Fp, CasE can be engineered into a live RNA tracking tool.

2021 ◽  
Vol 11 (1) ◽  
pp. 12-23
Author(s):  
Halime Turkkan

With the development of technology and the dominance of the digital world, typography has become a critical issue. Information design systems are considered as one of the significant areas of graphic design and big data provides essential information on data visualization. This research aims to analyse the effects of typographic elements on visualizing data in terms of visual communication, by discussing the value that typography gives to design space. The research discusses randomly selected 10 infographic design samples published in the last six months on google. From the results, 5 designs with typographic concern were more favourable and visually more striking and preferable than the other 5 designs in terms of design disciplines. As in all areas of graphic design, it is argued that the power of typography is an indisputable concept in data visualization, which is seen as a sub-branch of information design. Keywords: data visualization; design; typography, significance, technology


2014 ◽  
Vol 144 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Chuck R. Smallwood ◽  
Lorne Jordan ◽  
Vy Trinh ◽  
Daniel W. Schuerch ◽  
Amparo Gala ◽  
...  

Spectroscopic analyses of fluorophore-labeled Escherichia coli FepA described dynamic actions of its surface loops during binding and transport of ferric enterobactin (FeEnt). When FeEnt bound to fluoresceinated FepA, in living cells or outer membrane fragments, quenching of fluorophore emissions reflected conformational motion of the external vestibular loops. We reacted Cys sulfhydryls in seven surface loops (L2, L3, L4, L5, L7 L8, and L11) with fluorophore maleimides. The target residues had different accessibilities, and the labeled loops themselves showed variable extents of quenching and rates of motion during ligand binding. The vestibular loops closed around FeEnt in about a second, in the order L3 > L11 > L7 > L2 > L5 > L8 > L4. This sequence suggested that the loops bind the metal complex like the fingers of two hands closing on an object, by individually adsorbing to the iron chelate. Fluorescence from L3 followed a biphasic exponential decay as FeEnt bound, but fluorescence from all the other loops followed single exponential decay processes. After binding, the restoration of fluorescence intensity (from any of the labeled loops) mirrored cellular uptake that depleted FeEnt from solution. Fluorescence microscopic images also showed FeEnt transport, and demonstrated that ferric siderophore uptake uniformly occurs throughout outer membrane, including at the poles of the cells, despite the fact that TonB, its inner membrane transport partner, was not detectable at the poles.


2020 ◽  
pp. 1-13
Author(s):  
Victoria Sayles

Each Concentrate revision guide is packed with essential information, key cases, revision tips, exam Q&As, and more. Concentrates show you what to expect in a law exam, what examiners are looking for, and how to achieve extra marks. This chapter discusses proprietary rights. These govern people’s ability to use and enjoy both land they physically possess and land physically possessed by others. Whilst technically all land is owned by the Crown, holding an estate in land, and in particular a freehold estate that gives one rights to possess, enjoy, and use the land forever, is tantamount to actual ownership. The other type of proprietary right is an interest in land. Whilst an estate gives one a slice of time to use and enjoy land one physically possesses, an interest gives the right to use and enjoy land physically possessed by another. Proprietary rights can be either legal or equitable in status.


Author(s):  
Iain McDonald ◽  
Anne Street

Each Concentrate revision guide is packed with essential information, key cases, revision tips, exam Q&As, and more. Concentrates show you what to expect in a law exam, what examiners are looking for, and how to achieve extra marks. When a person transfers legal title to another, the legal title is said to vest in the other person. This chapter considers the rules for the transfer of title (ownership) in property in relation to different types of property. The general principle is that unless the property has been transferred by the correct legal rules then the transfer fails; it is said to be imperfect. The chapter begins by briefly considering the legal rules in relation to validly transferring property to another person. It then deals with equitable rules which have developed to overcome the strict application of the legal rules of vesting.


2018 ◽  
Vol 12 (1) ◽  
pp. 77-92
Author(s):  
Matthias Löwe

Abstract Heterodiegetic narrators are not present in the story they tell. That is how Gérard Genette has defined heterodiegesis. But this definition of heterodiegesis leaves open what ›absence‹ of the narrator really means: If a friend of the protagonist tells the story but does not appear in it, is he therefore heterodiegetic? Or if a narrator tells something that happened before his lifetime, is he therefore heterodiegetic? These open questions reveal the vagueness of Genette’s definition. However, Simone Elisabeth Lang has recently made a clearer proposal to define heterodiegesis. She argues that narrators should be called heterodiegetic only if they are fundamentally distinguished from the ontological status of the fictional characters: Heterodiegetic narrators are not part of the story for logical reasons, because they are presented as inventors of the story. This is, for example, the case in Johann Wolfgang Goethe’s novel Elective Affinities (1809): In the beginning of this novel the narrator presents himself as inventor of the character’s names (»Edward – so we shall call a wealthy nobleman in the prime of life – had been spending several hours of a fine April morning in his nursery-garden«). Based on that recent definition of heterodiegesis my article deals with the question whether such heterodiegetic narrators can be unreliable. My question is: How could you indicate that the inventor of a fictitious story tells something which is not correct or incomplete? In answering this question, I refer to some proposals of Janina Jacke’s article in this journal. Jacke shows that the distinction between homodiegetic and heterodiegetic narrators should not be confused with the distinction between personal and non-personal narrators or with the distinction between restricted and all-knowing narrators. If you make such differentiations, then of course heterodiegetic narrators can be unreliable: They can omit some essential information or interpret the story inappropriately. Heterodiegetic narrators of an invented story can even lie to the reader or deceive themselves about some elements of the invention. That means: A heterodiegetic narration cannot only be value-related unreliable (›discordant narration‹), but also fact-related unreliable. My article delves especially into this type of unreliability and shows that heterodiegetic narrators of a fictitious story can be fact-related unreliable, if they tell something which was not invented by themselves. In that case, the narrator himself sometimes does not really know whether he tells a true or a fictitious story. Such narrators are unreliable if they assert that the story is true, although they are suggesting at the same time that it is not. I call this type of unreliable narrator a ›fabulating chronicler‹ (›fabulierender Chronist‹): On the one hand, such narrators present themselves as chroniclers of historical facts but, on the other hand, they seem to be fabulists who tell a fairy tale. This type of unreliability occurs especially if a narrator tells a legend or a story from the Bible. My article demonstrates this case in detail with two examples, namely two novels by Thomas Mann: The Holy Sinner (1951) and Joseph and His Brothers (1933–1943). My article also discusses some cases where it is not appropriate or counter-intuitive to call a heterodiegetic narrator ›unreliable‹: i. e. the narrator of Thomas Mann’s novel The Magic Mountain (1924) and the narrator of Johann Wolfgang Goethe’s novel Wilhelm Meister’s Apprenticeship (1795/1796). On the one hand, these narrators show some characteristics of unreliability, because they omit essential pieces of information. On the other hand, these narrators are barely shaped as characters, they are nearly non-personal. However, in order to describe a narrator as unreliable, it is – in my opinion – indispensable to refer to some traces of a narrative personality: Figural traits of a narrator provoke the reader to identify all depicting, describing and commenting sentences of a narration as utterances of one and the same ›psychic system‹ (Niklas Luhmann). Only narrators who can be interpreted as such a ›psychic system‹, provoke the reader to assume the role of an analyst or ›detective‹, who perhaps identifies the narrator’s discordance or unreliability. In my article the unreliability of a narration is understood as part of the composition and meaning of a literary work. I argue that a narrator cannot be described as unreliable without designating a semantic motivation for this composition by an act of interpretation. Therefore, my suggestion is that a narration should be merely called unreliable if it encourages the reader not only to imagine the told story, but also to imagine a discordant or unreliable storyteller.


1981 ◽  
Vol 213 (1191) ◽  
pp. 139-160 ◽  

This paper is a sequel to an earlier one (Neyman & Puri 1976), which deals with a hypothetical structural stochastic model of radiation effects in living cells. This model incorporates two important details of the mechanism overlooked in its mathematical treatment by the previous workers. The first is that the passage of a single ‘primary’ radiation particle generates a ‘cluster’ of secondaries which can produce ‘hits’ that damage the living cells. The second detail concerns the time scales of radiation damage and of the subsequent repair. The events of arrival of a primary particle, its generation of secondary particles and their causing ‘hits’ on the sensitive targets within the cells, all occur for all practical purposes instantly. On the other hand the subsequent changes in the damaged cell, such as repair, appear to require measurable amounts of time. While the biological and physical justifications for some of the underlying assumptions of the model were discussed in the previous paper referred to above, the present paper is concerned mainly with the mathematical details and also with how the model attempts to explain some of the empirical findings available in the literature.


2004 ◽  
Vol 12 (2) ◽  
pp. 3-7
Author(s):  
Stephen W. Carmichael ◽  
Wilma L. Lingle

Whereas too much of a good thing can be bad, too little of a good tiling can be good. In this case, the accidental dilution of X-rhodamine tubulin injected into living cells resulted in a heterogeneous labeling of micro tubules, rather than visualization of continuous structures. This heterogeneous labeling rendered a speckled image, hence the term fluorescent speckle microscopy (FSM) was introduced. It turns out that FSM yields particularly useful information on dynamic events within living cells, for example the assembly and disassembly of microtubules.There are two recent reviews of FSM by Clare Waterman-Storer and Gaudenz Danuser, one emphasizing the biologic applications of the technique, the other emphasizing the quantitative aspects. For their purposes, they defined a “speckle” as a diffraction-limited region of the image that is significantly brighter than its immediate environment. It can be calculated from the point-spread function (which is determined by the numerical aperture of the lens) that optimally a diffraction-limited region of about 250 nm can be imaged.


2015 ◽  
Vol 31 ◽  
pp. 42-49 ◽  
Author(s):  
Anna K. Rath ◽  
Andrea Rentmeister
Keyword(s):  

The Society’s Conversaziones this year were held on Thursday, 24 May 1951 and on Thursday, 28 June 1951. At the former there were thirty exhibits and at the latter twenty-four. The exhibits ranged through physical and biological sciences and once again the Society gratefully acknowledges the contribution of the exhibitors towards making these evenings, when the Society is host to its many friends, so successful. At both Conversaziones two films were shown, one entitled ‘ The freezing and thawing of living cells ’ which illustrated the work of Mr C. Polge, Mr J. Smiles and Dr Audrey Smith of the National Institute for Medical Research, London : the other film was entitled ‘ Medical aspects of venomous snakes ’ made by the Wellcome Foundation Limited. The former film showed how suspensions of fowl spermatozoa and of rabbit blood cells in the presence of glycerol could be taken to temperatures of — 60° C and on raising the temperature, the spermatozoa resumed fertility and the red blood cells are preserved from haemolysis. The film describing the snakes was in colour : that part of the photography dealing with living snakes was made at the London Zoo—not without some interesting moments ! These films, and the exhibits for the first Soirée, were seen by some 250 scholars on the morning of Friday, 25 May. Sir David Brunt, Vice-President and Physical Secretary, welcomed these young men and women of science, and Professor Finch, Chairman of the Soiree Committee, addressed them on some of the exhibits which they were about to see. From communications received since, it is clearly evident that this invitation to science scholars in the London area is greatly appreciated.


2012 ◽  
Vol 23 (16) ◽  
pp. 3133-3142 ◽  
Author(s):  
James R. LaFountain ◽  
Christopher S. Cohan ◽  
Rudolf Oldenbourg

We report on experiments directly in living cells that reveal the regulation of kinetochore function by tension. X and Y sex chromosomes in crane fly (Nephrotoma suturalis) spermatocytes exhibit an atypical segregation mechanism in which each univalent maintains K-fibers to both poles. During anaphase, each maintains a leading fiber (which shortens) to one pole and a trailing fiber (which elongates) to the other. We used this intriguing behavior to study the motile states that X-Y kinetochores are able to support during anaphase. We used a laser microbeam to either sever a univalent along the plane of sister chromatid cohesion or knock out one of a univalent's two kinetochores to release one or both from the resistive influence of its sister's K-fiber. Released kinetochores with attached chromosome arms moved poleward at rates at least two times faster than normal. Furthermore, fluorescent speckle microscopy revealed that detached kinetochores converted their functional state from reverse pac-man to pac-man motility as a consequence of their release from mechanical tension. We conclude that kinetochores can exhibit pac-man motility, even though their normal behavior is dominated by traction fiber mechanics. Unleashing of kinetochore motility through loss of resistive force is further evidence for the emerging model that kinetochores are subject to tension-sensitive regulation.


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