Development: Pattern and Process

1988 ◽  
Author(s):  
Keith Stewart Thomson
Keyword(s):  
Biological Systems ◽  
Gas Diffusion ◽  
Raw Material ◽  
Interactive System ◽  
Development Pattern ◽  
Gregory Bateson ◽  
Pattern And Process ◽  
Gene Level ◽  
General Physical ◽  
Special Circumstances

In a hierarchical system, the manifestations of pattern at one level tend to become the components of process at the next, an alternation that is repeated again and again. The processes of molecular genetics produce, under the special circumstances applying at the genomic level, a pattern of gene activity that is carried forward to the organism level. Here new developmental processes based on these gene-level patterns build new organism-level patterns, and these then become the raw material for deme-level processes acting at the next level. This duality of pattern and process operates in any interactive system and was addressed particularly by Gregory Bateson (1979). It requires that we discuss the phenomena of process and pattern separately, as well as discovering their interdependence especially when, as in biological systems, there is additional complexity present in the form of feedback of causations among levels. Implicit in any hierarchical analysis is the assumption that process always involves a lawful set of mechanisms. In all biological systems this lawfulness will be derived from two sources: from the immanent properties of the systems themselves, and from even more general laws applying across all biological systems. For example, the salivary glands and lungs of vertebrates are both constructed in part according to a strict set of developmental rules applying to mechanics of epithelia; these are examples of developmental constraints (Chapter 7). But the size and shape of the lungs also follow more general physical rules such as the gas diffusion laws or volume-surface area relationships that determine how big a lung is required for an animal of a given size. These are structure-function constraints. Biological systems also derive a major set of consistencies from the historical connectedness, through relation by descent, of the organisms concerned. These consistencies are often called “phyletic constraints” (Chapter 7). It is a basic approach in biology to use the analysis of pattern to approach an understanding of process, often first in terms of deriving the “rules” from study of consistency and regularity. This is where the great power of the comparative-analytical method lies.

Modules in Biological Networks

2013 ◽  
pp. 637-663
Author(s):  
Bing Zhang ◽  
Zhiao Shi
Keyword(s):  
Biological Networks ◽  
Protein Complex ◽  
Protein Function ◽  
Protein Function Prediction ◽  
Single Gene ◽  
Biological Systems ◽  
Function Prediction ◽  
Diverse Group ◽  
Biological Studies ◽  
Gene Level

One of the most prominent properties of networks representing complex systems is modularity. Network-based module identification has captured the attention of a diverse group of scientists from various domains and a variety of methods have been developed. The ability to decompose complex biological systems into modules allows the use of modules rather than individual genes as units in biological studies. A modular view is shaping research methods in biology. Module-based approaches have found broad applications in protein complex identification, protein function prediction, protein expression prediction, as well as disease studies. Compared to single gene-level analyses, module-level analyses offer higher robustness and sensitivity. More importantly, module-level analyses can lead to a better understanding of the design and organization of complex biological systems.

scholarly journals Russian exporters in the economic crisis caused by the COVID-19 pandemic

2021 ◽  
Vol 52 (4) ◽  
pp. 252-257
Author(s):  
N.A. Volchkova ◽  
Keyword(s):  
Survey Data ◽  
Economic Crisis ◽  
Market Access ◽  
Foreign Market ◽  
Raw Material ◽  
Negative Effects ◽  
Significant Difference ◽  
Input Side ◽  
Output Side ◽  
Special Circumstances

We report results of the analysis of the survey data collected from Russian non-raw material exporters in 2020. Survey data allows defining the main channels through which pandemic crisis affected firms’ performance and identifying measures the firms applied to adjust to the new shocks. About three quarters of the surveyed exporters reported negative effects of the crisis on their operations. At the same time, firms’ international exposure on input side did not increase the degree of companies’ vulnerability to the crisis: supply delays were equally likely to occur on the part of domestic and foreign partners. However, there was a statistically significant difference on output side: exporting companies faced growth opportunities in domestic market more often than in foreign destinations, while significant losses happened more often in the foreign markets. These results allow us to conclude that the international exposure of exporting companies in special circumstances of economic crisis, caused by COVID-19 pandemic, created additional risks on the sales side, but not on the input side. This is consistent with the increase in foreign market access costs due to the ban on international travels.

Modules in Biological Networks

2011 ◽  
pp. 248-274
Author(s):  
Bing Zhang ◽  
Zhiao Shi
Keyword(s):  
Biological Networks ◽  
Protein Complex ◽  
Protein Function ◽  
Protein Function Prediction ◽  
Single Gene ◽  
Biological Systems ◽  
Function Prediction ◽  
Diverse Group ◽  
Biological Studies ◽  
Gene Level

One of the most prominent properties of networks representing complex systems is modularity. Network-based module identification has captured the attention of a diverse group of scientists from various domains and a variety of methods have been developed. The ability to decompose complex biological systems into modules allows the use of modules rather than individual genes as units in biological studies. A modular view is shaping research methods in biology. Module-based approaches have found broad applications in protein complex identification, protein function prediction, protein expression prediction, as well as disease studies. Compared to single gene-level analyses, module-level analyses offer higher robustness and sensitivity. More importantly, module-level analyses can lead to a better understanding of the design and organization of complex biological systems.

Analysis of Coconut Carbon Fibers for Gas Diffusion Layer Material

2011 ◽  
Vol 462-463 ◽  
pp. 937-942 ◽  
Author(s):  
Nanik Indayaningsih ◽  
Dedi Priadi ◽  
Anne Zulfia ◽  
Suprapedi
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Diffusion Layer ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Raw Material ◽  
Inert Gas ◽  
Basic Material ◽  
Powder Density

The main compound of natural fibers is a hydrocarbon. The heating of hydrocarbon in inert gas produces charcoal or carbon. Carbon materials are widely used for several purposes depending on the physical and electric properties, for example for hydrogen storage, conductive or reinforced plastics, catalyst supports, batteries and fuel cells. The main raw material of Gas diffusion Layer (GDL) of the Proton Exchange Membrane Fuel Cell (PEMFC) is a carbon. The properties of GDL are porous and electron-conductive material, because of the function of GDL is to distribute the gas as fuel and electricity conductors. This study aims to analyze the carbon fibers made from coconut fibers for the application of GDL materials. The carbon fiber was made using pyrolysis process in the inert gas (nitrogen) at a certain temperature according to the analysis of Differential Thermal Analysis (DTA) 3000C, 4000C, 5000C, 6000C, and 9000C. The crystalstructure, carbon content, powder density and morphology of carbon fibers were observed using X-Ray Diffraction (XRD), fixed carbon according to ASTM D 1762-64, Archimedes method (BS 19202 Part 1A), and Scanning Electron Microscope (SEM), respectively. The results showed that the structure of carbon was amorphous, and content of 51% ̶ 71%, powder density of 0.42g/cm3 ̶ 0.71g/cm3. The morphology having many parallel hollows like a tube that are close to each other with diameters of 2m ̶ 10m, and in the wall of tube there are some porous with sizes around 1m. According to this analysis, the coconut carbon fiber enables to be applied as candidate for a basic material of GDL.

scholarly journals Stability and its manifestation in the chemical and biological worlds

2015 ◽  
Vol 51 (90) ◽  
pp. 16160-16165 ◽  
Author(s):  
Robert Pascal ◽  
Addy Pross
Keyword(s):  
Biological Systems ◽  
Second Law ◽  
Darwinian Selection ◽  
Physical Chemical ◽  
Logical Principle ◽  
General Physical

A logical principle that connects Boltzmann's second law and Darwinian selection places biological systems within a general physical/chemical framework.

scholarly journals ABOUT POSSIBILITIES OF THE SECONDARY WASTEWATER USING OF THE BIOENERGETIC COMPLEX

2020 ◽  
Vol 86 (8) ◽  
pp. 126-133
Author(s):  
Oleksandr Boychuk ◽  
Katherine Pershina ◽  
Olga Bystryk ◽  
Olga Gayday ◽  
Oleksandr Lyashevsky ◽  
...  
Keyword(s):  
Organic Matter ◽  
Biological Treatment ◽  
Suspended Particles ◽  
Raw Material ◽  
Recreational Water ◽  
Sulfonic Acids ◽  
Chemical Indicators ◽  
Wastewater Samples ◽  
General Physical ◽  
Physical And Chemical

The analysis of the general physical and chemical indicators and the maintenance of heavy metals of sewage of a bioenergy complex is carried out. It is established that the sedimentation rate of suspended particles in wastewater depends on the location of filtration fields with wastewater from the source of contamination. At the source, there is a maximum excess of the number of suspended particles with a minimum deposition rate. In all wastewater samples, the indicators of chemical and biological oxygen consumption exceeded the permissible standards by three orders of magnitude for reservoirs for recreational water use and those located within the settlements. Thus, this water cannot be discharged into any natural water basin and requires additional purification from organic matter. Also for this water, the use of biological treatment methods without additional chemicals is ineffective. The presence of a complex of macro- and microelements in wastewater in combination with a high content of organic matter (humus and sulfonic acids) may be the basis for their use as raw material for fertilizer production.

The influence of total pressure in the reactor and carrier gas on the chemical vapor deposition of Al from tri-isobutyl aluminum

1997 ◽  
Vol 12 (7) ◽  
pp. 1866-1871 ◽  
Author(s):  
Takakazu Suzuki
Keyword(s):  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Total Pressure ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Chemical Vapor ◽  
Gas Diffusion ◽  
Raw Material ◽  
Carrier Gas

The influence of total pressure in the chamber and carrier gases on the chemical vapor deposition of aluminum using tri-isobutyl aluminum was studied. The superior penetrability of chemical vapor deposition is expected to make it effective for aluminum deposition onto complex-shaped materials such as turbo-charger rotors, fibrous preform, and multifilament. It may also be a suitable method for the development of fiber-reinforced composite materials. The apparatus was composed of a raw material gas supply system, a three-zone electric furnace, a reaction chamber, an auto pressure controller, and an exhaust system. Aluminum was deposited onto a graphite fiber in the quartz reactor. The results show that, in the diffusion rate-determining stage of aluminum thermal decomposition, the rate of deposition for aluminum shows a marked increase as the pressure increases; in contrast, in the reaction rate-determining stage, this tendency is limited. This can be explained by the fact that, as the total pressure decreases, the gas diffusion coefficient becomes larger, and there is an increase in the uniformity of film formation. On the other hand, as the carrier gas flow rate increases, the amount of raw material supplied increases; consequently, a higher rate of deposition is obtained. Moreover, in the diffusion rate-determining stage, there is a tendency for an increase in flow rate to elevate the probability of arrival of the raw material, and, in combination with high temperatures, for nucleus generation to be accelerated and the average diameter of aluminum granules to become smaller. In the reaction rate-determining stage, there appears to be hardly any dependency of granule diameter on the flow rate. When Ar or He is used as the carrier gas, under the same conditions argon, rather than helium, is seen to increase the rate of deposition.

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.

Imaging molecules adsorbed onto electrodes under potential control by scanning probe microscopy

1991 ◽  
Vol 49 ◽  
pp. 376-377 ◽  
Author(s):  
N.J. Tao ◽  
J.A. DeRose ◽  
P.I. Oden ◽  
S.M. Lindsay
Keyword(s):  
Surface Charge ◽  
Environmental Effects ◽  
Scanning Probe Microscopy ◽  
Statistical Significance ◽  
Electrochemical Methods ◽  
Surface Structures ◽  
Scanning Probe ◽  
Potential Control ◽  
Afm Imaging ◽  
Special Circumstances

Clemmer and Beebe have pointed out that surface structures on graphite substrates can be misinterpreted as biopolymer images in STM experiments. We have been using electrochemical methods to react DNA fragments onto gold electrodes for STM and AFM imaging. The adsorbates produced in this way are only homogeneous in special circumstances. Searching an inhomogeneous substrate for ‘desired’ images limits the value of the data. Here, we report on a reversible method for imaging adsorbates. The molecules can be lifted onto and off the substrate during imaging. This leaves no doubt about the validity or statistical significance of the images. Furthermore, environmental effects (such as changes in electrolyte or surface charge) can be investigated easily.

Freeze-fracture cytochemistry: A goal set by Russell Steere in 1957

1993 ◽  
Vol 51 ◽  
pp. 60-61
Author(s):  
Nicholas J Severs
Keyword(s):  
Chemical Nature ◽  
Biological Systems ◽  
Freeze Fracture ◽  
Structural Components ◽  
Major Goal ◽  
Membrane Biology ◽  
Routine Application ◽  
The Future ◽  
Freeze Etching

In his pioneering demonstration of the potential of freeze-etching in biological systems, Russell Steere assessed the future promise and limitations of the technique with remarkable foresight. Item 2 in his list of inherent difficulties as they then stood stated “The chemical nature of the objects seen in the replica cannot be determined”. This defined a major goal for practitioners of freeze-fracture which, for more than a decade, seemed unattainable. It was not until the introduction of the label-fracture-etch technique in the early 1970s that the mould was broken, and not until the following decade that the full scope of modern freeze-fracture cytochemistry took shape. The culmination of these developments in the 1990s now equips the researcher with a set of effective techniques for routine application in cell and membrane biology.Freeze-fracture cytochemical techniques are all designed to provide information on the chemical nature of structural components revealed by freeze-fracture, but differ in how this is achieved, in precisely what type of information is obtained, and in which types of specimen can be studied.

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