The Tree of life: evolution and classification of living organisms

2015 ◽  
Vol 52 (09) ◽  
pp. 52-4754-52-4754
Keyword(s):  
Tree Of Life ◽  
Living Organisms

Natural history of ABC systems: not only transporters

2011 ◽  
Vol 50 ◽  
pp. 19-42 ◽  
Author(s):  
Elie Dassa
Keyword(s):  
Common Ancestor ◽  
Three Dimensional ◽  
Last Common Ancestor ◽  
Abc Proteins ◽  
Hypothetical Scenario ◽  
History Of ◽  
Phylogenetic Perspective ◽  
Living Organisms

In recent years, our understanding of the functioning of ABC (ATP-binding cassette) systems has been boosted by the combination of biochemical and structural approaches. However, the origin and the distribution of ABC proteins among living organisms are difficult to understand in a phylogenetic perspective, because it is hard to discriminate orthology and paralogy, due to the existence of horizontal gene transfer. In this chapter, I present an update of the classification of ABC systems and discuss a hypothetical scenario of their evolution. The hypothetical presence of ABC ATPases in the last common ancestor of modern organisms is discussed, as well as the additional possibility that ABC systems might have been transmitted to eukaryotes, after the two endosymbiosis events that led to the constitution of eukaryotic organelles. I update the functional information of selected ABC systems and introduce new families of ABC proteins that have been included recently into this vast superfamily, thanks to the availability of high-resolution three-dimensional structures.

The classification of pollutants and their pathways in the atmosphere

1979 ◽  
Vol 290 (1376) ◽  
pp. 469-476 ◽  
Keyword(s):  
Boundary Layer ◽  
Human Life ◽  
Biogeochemical Cycles ◽  
Climatic Conditions ◽  
Atmospheric Pollutants ◽  
Relative Importance ◽  
Natural Sources ◽  
Living Organisms ◽  
Broad Classification

Atmospheric pollutants may damage, directly or indirectly, human life and health, other living organisms and complete ecosystems, human artefacts, and climatic conditions. The development of appropriate policies and methods for control of pollution requires, inter alia , an assessment of the routes taken by pollutants or their precursors through the atmosphere. Consideration of these routes leads to a broad classification on a local, regional or global basis associated mainly, but not exclusively, with the terrestrial boundary layer, with the troposphere and with the stratosphere respectively. This may require in some cases the perspective of total biogeochemical cycles, and in any event of the relative importance of man-made and natural sources of materials to be regarded as pollutants.

scholarly journals Recognition of Pharmacological Bi-Heterocyclic Compounds by Using Terahertz Time Domain Spectroscopy and Chemometrics

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3349 ◽  
Author(s):  
Maciej Roman Nowak ◽  
Rafał Zdunek ◽  
Edward Pliński ◽  
Piotr Świątek ◽  
Małgorzata Strzelecka ◽  
...  
Keyword(s):  
Heterocyclic Compounds ◽  
Chemical Compounds ◽  
Functional System ◽  
Support Vector ◽  
Optimal Parameters ◽  
Terahertz Time Domain Spectroscopy ◽  
Kernel Support Vector Machine ◽  
Inflammatory Drugs ◽  
Living Organisms

In this study, we presented the concept and implementation of a fully functional system for the recognition of bi-heterocyclic compounds. We have conducted research into the application of machine learning methods to correctly recognize compounds based on THz spectra, and we have described the process of selecting optimal parameters for the kernel support vector machine (KSVM) with an additional `unknown’ class. The chemical compounds used in the study contain a target molecule, used in pharmacy to combat inflammatory states formed in living organisms. Ready-made medical products with similar properties are commonly referred to as non-steroidal anti-inflammatory drugs (NSAIDs) once authorised on the pharmaceutical market. It was crucial to clearly determine whether the tested sample is a chemical compound known to researchers or is a completely new structure which should be additionally tested using other spectrometric methods. Our approach allows us to achieve 100% accuracy of the classification of the tested chemical compounds in the time of several milliseconds counted for 30 samples of the test set. It fits perfectly into the concept of rapid recognition of bi-heterocyclic compounds without the need to analyse the percentage composition of compound components, assuming that the sample is classified in a known group. The method allows us to minimize testing costs and significant reduction of the time of analysis.

scholarly journals Statistical mechanics and hydrodynamics of bacterial suspensions

2009 ◽  
Vol 106 (37) ◽  
pp. 15567-15572 ◽  
Author(s):  
Aparna Baskaran ◽  
M. Cristina Marchetti
Keyword(s):  
Physical Model ◽  
Large Scale ◽  
Hydrodynamic Interactions ◽  
Nonequilibrium Phenomena ◽  
Active Particles ◽  
Cilia And Flagella ◽  
Living Organisms ◽  
The Individual ◽  
Scale Behavior

Unicellular living organisms, such as bacteria and algae, propel themselves through a medium via cyclic strokes involving the motion of cilia and flagella. Dense populations of such “active particles” or “swimmers” exhibit a rich collective behavior at large scales. Starting with a minimal physical model of a stroke-averaged swimmer in a fluid, we derive a continuum description of a suspension of active organisms that incorporates fluid-mediated, long-range hydrodynamic interactions among the swimmers. Our work demonstrates that hydrodynamic interactions provide a simple, generic origin for several nonequilibrium phenomena predicted or observed in the literature. The continuum model derived here does not depend on the microscopic physical model of the individual swimmer. The details of the large-scale physics do, however, differ for “shakers” (particles that are active but not self-propelled, such as melanocytes) and “movers” (self-propelled particles), “pushers” (most bacteria) and “pullers” (algae like Chlamydomonas). Our work provides a classification of the large-scale behavior of all these systems.

Science and creativity

2020 ◽  
Author(s):  
Flavia Bruno
Keyword(s):  
Chemical Reactions ◽  
Scientific Conference ◽  
Scientific Terminology ◽  
Educational Standard ◽  
The Earth ◽  
Hands On ◽  
Earth Structures ◽  
Lithospheric Plates ◽  
Living Organisms

<p>I teach Natural Sciences in a Liceo Artistico, a type of secondary school in Italy. It is designed to give students the skills to progress to any university, but specifically devoted to art related topics.<br>During my career I have been following the national educational standard of the Ministero dell’Istruzione, dell’Università e della Ricerca of my Country.<br>During the years students are involved in meaningful hands-on activities   such as the study of the rocks in the country, preparation of easy chemical reactions and observations through a microscope of vegetal and animal organisms. These last ones are very interesting in a Liceo Artistico where many topics focus on the study of the morphology.<br>The theory confirms what the students learn during the practical activities, furthermore it is important to acquire a correct scientific terminology as well as to be able to express scientific issues.<br>I teach during the year the following main topics:<br>Science of Earth: the Solar System, the two motions of the Earth, structures of the Earth surface (rivers, lakes, glaciers, oceans and seas), the Earth’s Spheres, the movement of lithospheric plates.<br>Biology: the characteristics and functions of living organisms especially the cells and the biodiversity. The Evolution, Mendel’s genetic laws, organism-environment relationship in order to valorize and to maintain the biodiversity. Chemistry: state of matter, classification of matter, the Mendeleev’s Periodic Table, the main chemical reactions, atomics models, chemical bonds, chemical nomenclature.<br>The extra-curricular course proposal of my school (POFT-Piano dell’Offerta Formativa Triennale) includes my project whose title is “Science and creativity”. The achievement is to create a link between scientific subjects and the art ones in order to approach knowledge which appear distant but have really many points to share.<br>Every year some classrooms study different topics such as the Nanoparticles, Biomimetic and this year the Adaptations of the animals.<br>After a scientific conference, plastic models and graphic drawings will be realised by the students, who starting from the scientific reality, can express their creativity.<br>During the years I organize some educational visits for example to the Botanic Garden as well as to the countryside; in this way the students have opportunities to create an e-book with texts and photographs.<br>For instance two years ago my classroom created an e-book with botanical cards and the following year another one with the title “Rocce a Milano” where students took pictures and texts about this topic.<br>Many classrooms and teachers are involved in this project for example Plastic and Drawing teachers, as well as Multimedia teachers. I manage to gather the interested teachers and to realize the projects.<br>With our productions we participate in competitions and we are sometimes selected.</p>

The rich but confusing terminology of biological nomenclature: a first step towards a comprehensive glossary

Bionomina ◽  
2011 ◽  
Vol 3 (1) ◽  
pp. 63-70
Author(s):  
Alain DUBOIS
Keyword(s):  
Scientific Discipline ◽  
Human Needs ◽  
Higher Taxa ◽  
Unique System ◽  
Basic Need ◽  
The Rich ◽  
Living Organisms ◽  
Protect Study

Biology deals with billions of living organisms, which display a great diversity but also share many characters, being the result of an evolution. Designating these organisms in a universal and unambiguous way is a basic need for communication, not only among taxonomists or even biologists, but with society as a whole. It is indispensable to have a unique system for distinguishing and naming the organisms that may be used for alimentary, agronomical, veterinary or medical purposes or for any other human needs, that may be responsible for diseases, pollutions, biotic invasions, that we may wish to protect, study or admire, etc. For all these purposes, we need a scientific discipline, taxonomy, dealing not only with the classification of living organisms into millions of classificatory units, the taxa, but also with the designation and indexation of these taxa (nomenclature). Biological nomenclature has to care for the scientific naming of millions of taxa (species and higher taxa like genera or families), the inventory of which is still very far from being finished.

Classification Synopsis and Classification of Living Organisms Sybil P. Parker

BioScience ◽  
1984 ◽  
Vol 34 (5) ◽  
pp. 330-330
Author(s):  
George Hechtel
Keyword(s):  
Living Organisms

XXIV.—The Life-history and Cytology of Reticularia Lycoperdon Bull

1928 ◽  
Vol 55 (3) ◽  
pp. 555-608 ◽  
Author(s):  
Malcolm Wilson ◽  
Elsie J. Cadman
Keyword(s):  
Life History ◽  
Early Stages ◽  
Living Organisms

During the last eighty years the Mycetozoa have attracted the attention of numerous investigators, largely on account of the striking differences in structure which are exhibited at successive stages in the life-history. The fact that during the early stages of their development they consist of naked masses of protoplasm and closely resemble certain lowly animal forms, while later on in the sporangial condition they assume plant-like characters, has given rise to numerous discussions as to their position in the classification of living organisms.

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