The fuzzy structure of populations

2002 ◽  
Vol 80 (12) ◽  
pp. 2235-2241 ◽  
Author(s):  
James A Schaefer ◽  
Chris C Wilson
Keyword(s):  
Rangifer Tarandus ◽  
Human Perception ◽  
Fuzzy Classification ◽  
Resolving Power ◽  
Biological Organization ◽  
Philosophical Foundations ◽  
Living Things ◽  
Biological World ◽  
Multiple Clusters ◽  
Management And Conservation

The human perception of biological organization has profound implications for the study, management, and conservation of living things. Traditional methods of classification, which imply all-or-nothing group membership, are inconsistent with the modern synthesis, which stresses variability and unique individuals. We propose that fuzzy classification, which allows fractional membership in multiple clusters, can more realistically denote many forms of biological organization, such as populations. We used fuzzy clustering to depict the ambiguous structure of a migratory caribou (Rangifer tarandus) herd, based on affinities in space use, and walleye (Stizostedion vitreum) stocks, based on genetic dissimilarities among multilocus genotypes. In both cases, fuzzy memberships conveyed the degree of uncertainty of belonging while resolving cluster memberships for unambiguous and problematic individuals. Vagueness implies that borderline group identity cannot be remedied with more resolving power. Fuzzy classification is more in tune with the empirical and philosophical foundations of our discipline and can reconcile our need to classify with an inherently vague biological world.

scholarly journals Standards. The building blocks of complexity

2021 ◽  
Author(s):  
Juli Peretó ◽  
Manuel Porcar
Keyword(s):  
Synthetic Biology ◽  
Mechanical Design ◽  
Building Blocks ◽  
Open Science ◽  
Research And Innovation ◽  
Living Things ◽  
Key Factor ◽  
Cellular Context ◽  
Cultural Standards ◽  
Biological World

Without standards, the world as we know it would not be possible. International and supra-cultural standards and norms have been a key factor in engineering, as well as in the development of industrial societies. Despite the obvious successes in electronic and mechanical design, other technological areas present difficulties for the application of standards. In the field of biotechnology and synthetic biology – which aims at studying living things from an engineering perspective – standards are desirable, but whether they can be widely adopted remains to be proved. This monograph reviews the sociological and scientific aspects of standardisation and delves into the more problematic facets of universal standardisation, especially in the biological field. Are standards possible in synthetic biology at all? What are the limitations to the universal use of modular and interchangeable parts in a cellular context? Could it be that the biological world resists standardisation, similarly to the field of software engineering, where these attempts have not progressed? And should some kind of standard be applicable in synthetic biology, what qualities might be required in an environment of open science and responsible research and innovation?

scholarly journals The pace of life: Time, temperature, and a biological theory of relativity

2019 ◽  
Author(s):  
Anna B. Neuheimer
Keyword(s):  
Biological Theory ◽  
Life Time ◽  
Special Theory ◽  
Theory Of Relativity ◽  
Calendar Time ◽  
Biological Time ◽  
Biological Phenomena ◽  
Living Things ◽  
Biological World ◽  
Future Work

AbstractFor living things, time proceeds relative to body temperature. In this contribution, I describe the biochemical underpinnings of this “biological time” and formalize the Biological Theory of Relativity (BTR). Paralleling Einstein’s Special Theory of Relativity, the BTR describes how time progresses across temporal frames of reference, contrasting temperature-scaled biological time with our more familiar (and constant) “calendar” time measures. By characterizing the relationship between these two time frames, the BTR allows us to position observed biological variability on a relevant time-scale. In so doing, we are better able to explain observed variation (both temperature-dependent and -independent), make predictions about the timing of biological phenomena, and even manipulate the biological world around us. The BTR presents a theoretical framework to direct future work regarding an entire landscape of fundamental biological questions across space, time and species.

Bioorganic Synthesis Engineering

2001 ◽  
Author(s):  
L. K. Doraiswamy
Keyword(s):  
Organic Synthesis ◽  
Heterogeneous Catalysts ◽  
Wide Spectrum ◽  
Chemical Transformations ◽  
Biological Organization ◽  
Organic Cosolvents ◽  
Living Things ◽  
Wide Range ◽  
Bioorganic Synthesis ◽  
Unique Ability

Biological processes, from the simplest to the most complex, can broadly be classified as those caused by the catalytic action of living entities known as microorganisms or microbes, and those promoted and catalyzed by “lifeless substances” produced by microorganisms, known as enzymes. The two together are often referred to as biocatalysts. The microbial kingdom of living entities consists of all living things with a very simple biological organization. Both microbes and enzymes can be used to promote or selectively achieve a wide range of chemical transformations. Indeed, biocatalysts occupy a unique position in the wide spectrum of catalysts used in organic technology and synthesis. One of the chief beneficiaries of the rising emphasis on environmentally friendly processes is the enzyme, for it is being increasingly pressed into service to generate technologies that are both highly selective and pollution free. As catalysts, enzymes accelerate the rates of reactions at milder conditions, are highly selective, are biodegradable, and can be used in “free” solution form or as immobilized heterogeneous catalysts. The last feature, their use in immobilized form, has been a major factor in the movement of the enzyme from laboratory to industry. Two main shortcomings of the conventional enzyme that have limited its application in organic synthesis are its restriction to reactions in the aqueous phase and to very mild temperatures and pressures. Research in the last few years has “released” the enzyme from these restrictions (see Govardhan and Margolin, 1995; Adams et al., 1995). Thus now it is possible to use enzymes in aqueous solutions containing water-miscible organic cosolvents, aqueous organic biphasic mixtures, and anhydrous organic solvents. Research has also uncovered microorganisms from a variety of unconventional habitats such as the biosphere and the depths of the oceans that have the unique ability to accomplish chemical transformations at extreme conditions covering a wide range of temperatures, pressures, and salt concentrations. Hence it seems almost certain that enzymes will play an increasingly important role in industrial organic synthesis.

Preparatory Procedures for Electron Microscopic Analysis at the Molecular Level of Resolution

1978 ◽  
Vol 36 (3) ◽  
pp. 516-520
Author(s):  
F.J. Sjostrand
Keyword(s):  
Electron Microscope ◽  
Molecular Level ◽  
Microscopic Analysis ◽  
Resolving Power ◽  
Cellular Structures ◽  
Electron Microscopic ◽  
Systematic Analysis ◽  
Technical Developments ◽  
Thin Sectioning ◽  
Obvious Reason

In the 1940's and 1950's electron microscopy conferences were attended with everybody interested in learning about the latest technical developments for one very obvious reason. There was the electron microscope with its outstanding performance but nobody could make very much use of it because we were lacking proper techniques to prepare biological specimens. The development of the thin sectioning technique with its perfectioning in 1952 changed the situation and systematic analysis of the structure of cells could now be pursued. Since then electron microscopists have in general become satisfied with the level of resolution at which cellular structures can be analyzed when applying this technique. There has been little interest in trying to push the limit of resolution closer to that determined by the resolving power of the electron microscope.

Introduction to Cell Membranes at Molecular Resolution

1978 ◽  
Vol 36 (3) ◽  
pp. 497-502
Author(s):  
R.J. Barrnett
Keyword(s):  
Cell Membranes ◽  
International Federation ◽  
Mountain Range ◽  
Cellular Membranes ◽  
Short History ◽  
Biological Organization ◽  
Macromolecular Assemblies ◽  
The Past

This subject, is like observing the panorama of a mountain range, magnificent towering peaks, but it doesn't take much duration of observation to recognize that they are still in the process of formation. The mountains consist of approaches, materials and methods and the rocky substance of information has accumulated to such a degree that I find myself concentrating on the foothills in the foreground in order to keep up with the advance; the edifices behind form a wonderous, substantive background. It's a short history for such an accumulation and much of it has been moved by the members of the societies that make up this International Federation. My panel of speakers are here to provide what we hope is an interesting scientific fare, based on the fact that there is a continuum of biological organization from biochemical molecules through macromolecular assemblies and cellular membranes to the cell itself. Indeed, this fact explains the whole range of towering peaks that have emerged progressively during the past 25 years.

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

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