scholarly journals Exploiting nanobodies and Affimers for superresolution imaging in light microscopy

2019 ◽  
Vol 30 (22) ◽  
pp. 2737-2740 ◽  
Author(s):  
Glenn Carrington ◽  
Darren Tomlinson ◽  
Michelle Peckham

Antibodies have long been the main approach used for localizing proteins of interest by light microscopy. In the past 5 yr or so, and with the advent of superresolution microscopy, the diversity of tools for imaging has rapidly expanded. One main area of expansion has been in the area of nanobodies, small single-chain antibodies from camelids or sharks. The other has been the use of artificial scaffold proteins, including Affimers. The small size of nanobodies and Affimers compared with the traditional antibody provides several advantages for superresolution imaging.

Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


Author(s):  
Prakash Rao

Image shifts in out-of-focus dark field images have been used in the past to determine, for example, epitaxial relationships in thin films. A recent extension of the use of dark field image shifts has been to out-of-focus images in conjunction with stereoviewing to produce an artificial stereo image effect. The technique, called through-focus dark field electron microscopy or 2-1/2D microscopy, basically involves obtaining two beam-tilted dark field images such that one is slightly over-focus and the other slightly under-focus, followed by examination of the two images through a conventional stereoviewer. The elevation differences so produced are usually unrelated to object positions in the thin foil and no specimen tilting is required.In order to produce this artificial stereo effect for the purpose of phase separation and identification, it is first necessary to select a region of the diffraction pattern containing more than just one discrete spot, with the objective aperture.


Author(s):  
D. R. Abrahamson ◽  
P. L. St.John ◽  
E. W. Perry

Antibodies coupled to tracers for electron microscopy have been instrumental in the ultrastructural localization of antigens within cells and tissues. Among the most popular tracers are horseradish peroxidase (HRP), an enzyme that yields an osmiophilic reaction product, and colloidal gold, an electron dense suspension of particles. Some advantages of IgG-HRP conjugates are that they are readily synthesized, relatively small, and the immunolabeling obtained in a given experiment can be evaluated in the light microscope. In contrast, colloidal gold conjugates are available in different size ranges and multiple labeling as well as quantitative studies can therefore be undertaken through particle counting. On the other hand, gold conjugates are generally larger than those of HRP but usually can not be visualized with light microscopy. Concern has been raised, however, that HRP reaction product, which is exquisitely sensitive when generated properly, may in some cases distribute to sites distant from the original binding of the conjugate and therefore result in spurious antigen localization.


1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.


2010 ◽  
Vol 51 (1-2) ◽  
pp. 215-224
Author(s):  
Alexander Carpenter

This paper explores Arnold Schoenberg’s curious ambivalence towards Haydn. Schoenberg recognized Haydn as an important figure in the German serious music tradition, but never closely examined or clearly articulated Haydn’s influence and import on his own musical style and ethos, as he did with many other major composers. This paper argues that Schoenberg failed to explicitly recognize Haydn as a major influence because he saw Haydn as he saw himself, namely as a somewhat ungainly, paradoxical figure, with one foot in the past and one in the future. In his voluminous writings on music, Haydn is mentioned by Schoenberg far less frequently than Bach, Mozart, or Beethoven, and his music appears rarely as examples in Schoenberg’s theoretical texts. When Schoenberg does talk about Haydn’s music, he invokes — with tacit negativity — its accessibility, counterpoising it with more recondite music, such as Beethoven’s, or his own. On the other hand, Schoenberg also praises Haydn for his complex, irregular phrasing and harmonic exploration. Haydn thus appears in Schoenberg’s writings as a figure invested with ambivalence: a key member of the First Viennese triumvirate, but at the same time he is curiously phantasmal, and is accorded a peripheral place in Schoenberg’s version of the canon and his own musical genealogy.


2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Kempe Ronald Hope

Countries with positive per capita real growth are characterised by positive national savings—including government savings, increases in government investment, and strong increases in private savings and investment. On the other hand, countries with negative per capita real growth tend to be characterised by declines in savings and investment. During the past several decades, Kenya’s emerging economy has undergone many changes and economic performance has been epitomised by periods of stability, decline, or unevenness. This article discusses and analyses the record of economic performance and public finance in Kenya during the period 1960‒2010, as well as policies and other factors that have influenced that record in this emerging economy. 


1999 ◽  
Vol 150 (12) ◽  
pp. 484-488 ◽  
Author(s):  
Wolf Hockenjos

Concepts of near-natural forestry are in great demand these days. Most German forest administrations and private forest enterprises attach great importance to being as «near-natural» as possible. This should allow them to make the most of biological rationalisation. The concept of near-natural forestry is widely accepted, especially by conservationists. However, it is much too early to analyse how successful near-natural forestry has been to date, and therefore to decide whether an era of genuine near-natural forest management has really begun. Despite wide-spread recognition, near-natural forestry is jeopardised by mechanised timber harvesting, and particularly by the large-timber harvester. The risk is that machines, which are currently just one element of the timber harvest will gain in importance and gradually become the decisive element. The forest would then be forced to meet the needs of machinery, not the other way round. Forests would consequently become so inhospitable that they would bear no resemblance to the sylvan image conjured up by potential visitors. This could mean taking a huge step backwards: from a near-natural forest to a forest dominated by machinery. The model of multipurpose forest management would become less viable, and the forest would become divided into areas for production, and separate areas for recreation and ecology. The consequences of technical intervention need to be carefully considered, if near-natural forestry is not to become a thing of the past.


Author(s):  
Daiva Milinkevičiūtė

The Age of Enlightenment is defined as the period when the universal ideas of progress, deism, humanism, naturalism and others were materialized and became a golden age for freemasons. It is wrong to assume that old and conservative Christian ideas were rejected. Conversely, freemasons put them into new general shapes and expressed them with the help of symbols in their daily routine. Symbols of freemasons had close ties with the past and gave them, on the one hand, a visible instrument, such as rituals and ideas to sense the transcendental, and on the other, intense gnostic aspirations. Freemasons put in a great amount of effort to improve themselves and to create their identity with the help of myths and symbols. It traces its origins to the biblical builders of King Solomon’s Temple, the posterity of the Templar Knights, and associations of the medieval craft guilds, which were also symbolical and became their link not only to each other but also to the secular world. In this work we analysed codified masonic symbols used in their rituals. The subject of our research is the universal Masonic idea and its aspects through the symbols in the daily life of the freemasons in Vilnius. Thanks to freemasons’ signets, we could find continuity, reception, and transformation of universal masonic ideas in the Lithuanian freemasonry and national characteristics of lodges. Taking everything into account, our article shows how the universal idea of freemasonry spread among Lithuanian freemasonry, and which forms and meanings it incorporated in its symbols. The objective of this research is to find a universal Masonic idea throughout their visual and oral symbols and see its impact on the daily life of the masons in Vilnius. Keywords: Freemasonry, Bible, lodge, symbols, rituals, freemasons’ signets.


Worldview ◽  
1960 ◽  
Vol 3 (9) ◽  
pp. 7-8
Author(s):  
Will Herberg

John Courtney Murray's writing cannot fail to be profound and instructive, and I have profited greatly from it in the course of the past decade. But I must confess that his article, "Morality and Foreign Policy" (Worldview, May), leaves me in a strange confusion of mixed feelings. On the one hand, I can sympathize with what I might call the historical intention of the natural law philosophy he espouses, which I take to be the effort to establish enduring structures of meaning and value to serve as fixed points of moral decision in the complexities of the actual situation. On the other hand, I am rather put off by the calm assurance he exhibits when he deals with these matters, as though everything were at bottom unequivocally rational and unequivocally accessible to the rational mind. And I am really distressed at what seems to 3ie to be his woefully inadequate appreciation of the position of the "ambiguists," among whom I cannot deny I count myself.


2020 ◽  
Vol 8 (4) ◽  
pp. 389-397
Author(s):  
Meghan J. Dudley ◽  
Jenna Domeischel

ABSTRACTAlthough we, as archaeologists, recognize the value in teaching nonprofessionals about our discipline and the knowledge it generates about the human condition, there are few of these specialists compared to the number of archaeologists practicing today. In this introductory article to the special section titled “Touching the Past to Learn the Past,” we suggest that, because of our unique training as anthropologists and archaeologists, each of us has the potential to contribute to public archaeology education. By remembering our archaeological theory, such as social memory, we can use the artifacts we engage with on a daily basis to bridge the disconnect between what the public hopes to gain from our interactions and what we want to teach them. In this article, we outline our perspective and present an overview of the other three articles in this section that apply this approach in their educational endeavors.


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