Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

Relationship of Skeletal Muscle Atrophy to Functional Status: A Systematic Research Review

2000 ◽  
Vol 2 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Kathleen Michael
Keyword(s):  
Muscle Atrophy ◽  
Elderly Women ◽  
Functional Limitation ◽  
Skeletal Muscle Atrophy ◽  
Research Review ◽  
Systematic Research ◽  
Form And Function ◽  
And Function ◽  
Relationship Of ◽  
The Relationship

In the realm of muscle atrophy research, many studies address minute details of molecular function but few examine the effects of atrophy in terms of mobility, strength, endurance, and performance of activities of daily living. The relationship between impairment and functional limitation is the focus of this research review. A wide array of studies constitute this area of inquiry, including investigations as diverse and widely disparate as molecular chemistry and space travel and populations as different as rats, healthy young men, and elderly women. Thirty-four studies were selected based on their fit with the Enabling-Disabling Model. Three paradigms of atrophy and function emerged. Adaptation reflects the plastic nature of muscle when placed under certain conditions, ranging from disuse to high-resistance exercise. Injury/loss describes damage to muscle tissue from ischemia, medications, or reloading or reperfusion trauma. Also in this category is the loss of muscle that is seen with aging. Integrity relates to the muscle’s tendency to protect itself and maintain structural adjacencies and cellular proportions. Based on the 3 muscle research paradigms, the relationship of muscle atrophy to function is portrayed as a bidirectional interaction wherein form and function have an influence on each other by way of physical changes, including those of adaptation, injury/loss, or integrity. A conceptual model is constructed to reflect this relationship.

Verb inflection in Ancient Greek and Sanskrit and auxiliation patterns in French and Italian

2009 ◽  
Vol 32 (1) ◽  
pp. 55-76 ◽  
Author(s):  
Nunzio La Fauci ◽  
Liana Tronci
Keyword(s):  
Complex Interaction ◽  
Ancient Greek ◽  
Form And Function ◽  
European Languages ◽  
Verb Inflection ◽  
The Subject ◽  
The Difference ◽  
Verb Inflections ◽  
And Function ◽  
The Relationship

This paper deals with the complex interaction between form and function in the verb morphosyntax of four Indo-European languages (French, Italian, Ancient Greek and Sanskrit). Beyond the difference in form, auxiliation patterns in French and Italian, and verb inflections in Ancient Greek and Sanskrit correlate, thanks to the agreement for number and person, to the expression of the relationship with the Subject. The different auxiliation patterns (sum and habeo) and the different inflections (middle and active) correlate to different properties of the Subject. In particular, these forms depend on the syntactic opposition between middle and non-middle. The ways of this dependency are regulated and systematic, although they appear fuzzy and chaotic, not only if the four languages are compared to each other, but also if different morphosyntactic combinations, inside the same language, are concerned.

Towards a pragmatic approach to the study of languages in contact

Pragmatics ◽  
1991 ◽  
Vol 1 (4) ◽  
pp. 465-480 ◽  
Author(s):  
Joan A. Argente ◽  
Lluís Payrató
Keyword(s):  
Language Contact ◽  
Communicative Competence ◽  
Form And Function ◽  
Languages In Contact ◽  
The Social ◽  
Interactive Strategies ◽  
And Function ◽  
Adaptation Processes ◽  
The Relationship ◽  
New Distribution

The study of language contact has been traditionally carried out from a structural perspective (synchronic or diachronic), from a sociolinguistic perspective and/or from a rather psychological perspective, centered on the linguistic and communicative competence of the multilingual individual. However, a great number of linguistic and sociolinguistic topics that appear in language contact situations may be productively tackled from a pragmatic viewpoint. This pragmatic perspective takes into account linguistic use in communication contexts and raises, at a different level, questions that deal with the structures and the evolution of the codes in contact. The main aim of this presentation is the analysis of some of the specific problems that arise in given language contact situations from a pragmatic perspective, considering the adaptation processes of the speakers, their particular interactive strategies and the social meaning generated. Understanding pragmatics in its original sense, i.e. as the study of the relationship between linguistic signs and speakers (users of certain resources), these phenomena should be understood as the result of speakers’ adaptation to changing sociocultural circumstances. This adaptation creates a new distribution of the verbal resources (or linguistic economy) of the community and, consequently, modifies its varieties as far as form and function are concerned.

English as a Lingua Franca: form follows function

English Today ◽  
2008 ◽  
Vol 24 (3) ◽  
pp. 58-61 ◽  
Author(s):  
Alessia Cogo
Keyword(s):  
Research Field ◽  
World Englishes ◽  
Lingua Franca ◽  
Form And Function ◽  
The World ◽  
And Function ◽  
The Relationship

ABSTRACTIn this paper I wish to respond to the article published in ET94 by Saraceni while at the same time providing some clarifications concerning the concept of English as a Lingua Franca (henceforth ELF). In his article Saraceni raises three main questions (and a number of related debatable comments which I will quickly deal with in my final remarks) regarding: 1) the nature of ELF and its speakers, 2) the relationship between ELF and the World Englishes (henceforth WE) paradigm, and 3) the distinction between form and function. I will address each of these questions, and in so doing consider a number of notions concerning the ELF research field.

Scanning Tunneling Microscopy Study of α,ω-Dihexylsexithiophene Adlayers on Au(111): A Chiral Separation Induced by a Surface

2012 ◽  
Vol 18 (4) ◽  
pp. 885-891 ◽  
Author(s):  
Yonghai Song ◽  
Yu Wang ◽  
Lingli Wan ◽  
Shuhong Ye ◽  
Haoqing Hou ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
Room Temperature ◽  
Three Dimensional ◽  
Microscopy Study ◽  
Molecular Structures ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Left Handed ◽  
Bulk Structure

AbstractThe self-assembly of α,ω-dihexylsexithiophene molecules on an Au(111) surface was examined by using scanning tunneling microscopy at room temperature, revealing the internal molecular structures of the sexithiophene backbones and the hexyl side chains. The α,ω-dihexylsexithiophene formed a large and well-ordered monolayer in which the molecule lay flatly on the Au(111) surface and was separated into two chiral domains. A detailed observation reveals that the admolecules were packed in one lamellae with their molecular axis aligned along the main axis of the Au(111) substrate with their hexyl chains deviated from ⟨110⟩ direction of the Au(111) substrate by 12 ± 0.5°. In contrast to the behavior in the three-dimensional bulk structure, flat-lying adsorption introduced molecular chirality: right- and left-handed molecules separate into domains of two different orientations, which are mirror symmetric with respect to the ⟨121⟩ direction of the Au(111) substrate. Details of the adlayer structure and the chiral self-assembly were discussed here.

scholarly journals Examining Form and Function of Dendritic Spines

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kevin F. H. Lee ◽  
Cary Soares ◽  
Jean-Claude Béïque
Keyword(s):  
Dendritic Spines ◽  
Laser Scanning ◽  
Molecular Mechanisms ◽  
Laser Scanning Microscopy ◽  
Spine Morphology ◽  
Functional Changes ◽  
Form And Function ◽  
Spine Structure ◽  
And Function ◽  
The Relationship

The majority of fast excitatory synaptic transmission in the central nervous system takes place at protrusions along dendrites called spines. Dendritic spines are highly heterogeneous, both morphologically and functionally. Not surprisingly, there has been much speculation and debate on the relationship between spine structure and function. The advent of multi-photon laser-scanning microscopy has greatly improved our ability to investigate the dynamic interplay between spine form and function. Regulated structural changes occur at spines undergoing plasticity, offering a mechanism to account for the well-described correlation between spine size and synapse strength. In turn, spine structure can influence the degree of biochemical and perhaps electrical compartmentalization at individual synapses. Here, we review the relationship between dendritic spine morphology, features of spine compartmentalization and synaptic plasticity. We highlight emerging molecular mechanisms that link structural and functional changes in spines during plasticity, and also consider circumstances that underscore some divergence from a tight structure-function coupling. Because of the intricate influence of spine structure on biochemical and electrical signalling, activity-dependent changes in spine morphology alone may thus contribute to the metaplastic potential of synapses. This possibility asserts a role for structural dynamics in neuronal information storage and aligns well with current computational models.

scholarly journals Material approaches to exploring the borders of paratext

2019 ◽  
Vol 11 (1-2) ◽  
pp. 106-129
Author(s):  
Sirkku Inkeri Ruokkeinen ◽  
Aino Liira
Keyword(s):  
Early Modern ◽  
Book History ◽  
Form And Function ◽  
Gray Area ◽  
Theoretical Approaches ◽  
Starting Point ◽  
Good Starting Point ◽  
And Function ◽  
Relationship Of ◽  
The Relationship

This article examines the relationship of material text (text of the document) and paratext in light of fourteenth to sixteenth century evidence. Despite the wealth of interest generated by paratexts and paratextuality in recent years, especially in the fields of literary studies, book history, and translation studies, theoretical approaches to paratexts and paratextuality remain scarce. The paratextual status of an element is typically determined by its function, in combination with its distance from the material text: elements within the codex which do not share space with the text are part of the paratext. Less studied, however, is the gray area of elements which are located within the codex and share the space with the text. We examine this border between text and paratext through an analysis of late medieval and early modern initials, typeface, script and notes. While the form and function of the element are a good starting point, we propose that gauging the optionality of the element, in relation to the abstract text of the work and the material text of the document, is a better indicator of its paratextual status. Optionality should therefore be taken into consideration as evidence of a type of contemporary paratextual understanding.

scholarly journals A Short History and Demonstration of the Dynamic Table of Contexts

2013 ◽  
Vol 3 (4) ◽  
Author(s):  
Brent Nelson ◽  
Stéfan Sinclair ◽  
Susan Brown ◽  
Milena Radzikowska ◽  
Mark Bieber ◽  
...  
Keyword(s):  
Interface Design ◽  
Theoretical Framework ◽  
Common Element ◽  
Textual Studies ◽  
Short History ◽  
Digital Medium ◽  
Form And Function ◽  
New Knowledge ◽  
And Function ◽  
The Relationship

This paper presents a brief account of the form and function of the “table of contents” to establish a theoretical framework for understanding the form and function of this common element of book architecture with the aim of informing the development of a dynamic table of contexts for books and reading in the digital medium. This paper will thus theorize the relationship between textual studies and interface design in INKE, a project for Implementing New Knowledge Environments.

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