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Oxygen in the Universe

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ISBN: 9782759807109 Year: Language: English
Publisher: EDP SCIENCES
Subject: Chemical Technology
Added to DOAB on : 2014-07-31 12:11:29
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This book, written by a group of specialists in the different areas involved, summarises what we understand of the production and distribution of oxygen, the most abundant metal in the Universe. After presenting the methods of oxygen abundance determination in various media, it traces a panorama of oxygen in the Universe, describes the mechanisms and sites of oxygen production and finally discusses the chemical evolution of oxygen in different galactic and extra galactic contexts. An appendix thoroughly discusses the oxygen atomic data.

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Oxygen

New Concepts in Imaging: Optical and Statistical Models

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ISBN: 9782759809585 Year: Language: English
Publisher: EDP SCIENCES
Subject: Biology
Added to DOAB on : 2014-07-31 12:13:46
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Abstract

This book, written by a group of specialists in the different areas involved, summarises what we understand of the production and distribution of oxygen, the most abundant metal in the Universe. After presenting the methods of oxygen abundance determination in various media, it traces a panorama of oxygen in the Universe, describes the mechanisms and sites of oxygen production and finally discusses the chemical evolution of oxygen in different galactic and extra galactic contexts. An appendix thoroughly discusses the oxygen atomic data.

Keywords

Oxygen

Plant responses to flooding

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193042 Year: Pages: 142 DOI: 10.3389/978-2-88919-304-2 Language: English
Publisher: Frontiers Media SA
Subject: Botany --- Physiology --- Science (General)
Added to DOAB on : 2016-02-05 17:24:33
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Global warming has dramatically increased the frequency and severity of flooding events worldwide. As a result, many man-made and natural ecosystems have become flood-prone. For plants, the main consequence of flooding is the drastic reduction of oxygen availability that restricts respiratory energy production and finally affects survival. Flooding can negatively influence crop production and wild plant distributions, since most plants are sensitive to excessively wet conditions. However, plants have evolved a broad spectrum of adaptive responses to oxygen deficiency that eventually leads to tolerance. Many of these morphological and physiological adaptations have been described in some crops and wild plant species and considerable progress has been made in understanding the molecular aspects governing tolerance traits. Moreover, the molecular mechanism of plant oxygen sensing has been recently elucidated. However, many other aspects concerning plant acclimation responses to flooding remain unanswered. With this research topic we seek to build an online collection of articles addressing various aspects relating to “plant responses to flooding’’ which will reflect the exciting new developments and current state of the art in this vibrant and dynamic research field. All kinds of articles, including original research articles, short reviews, methods and opinions are welcome, in the attempt to broadly and freely disseminate research information, tools and protocols.

Keywords

Anoxia --- flooding --- hypoxia --- low oxygen --- submergence --- waterlogging

Melatonin in Plants

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889453115 Year: Pages: 297 DOI: 10.3389/978-2-88945-311-5 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Botany
Added to DOAB on : 2018-02-27 16:16:45
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This topic focuses on distribution, synthesis, metabolism, and the in vivo roles of melatonin in plants, with 1 editorial, 3 reviews, 21 original research studies and 1 corrigendum.

Novel Non-Precious Metal Electrocatalysts for Oxygen Electrode Reactions

Authors: --- ---
ISBN: 9783039215409 / 9783039215416 Year: Pages: 190 DOI: 10.3390/books978-3-03921-541-6 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Physics (General)
Added to DOAB on : 2019-12-09 11:49:16
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Research on alternative energy harvesting technologies, conversion and storage systems with high efficiency, cost-effective and environmentally friendly systems, such as fuel cells, rechargeable metal-air batteries, unitized regenerative cells, and water electrolyzers has been stimulated by the global demand on energy. The conversion between oxygen and water plays a key step in the development of oxygen electrodes: oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), processes activated mostly by precious metals, like platinum. Their scarcity, their prohibitive cost, and declining activity greatly hamper large-scale applications. This issue reports on novel non-precious metal electrocatalysts based on the innovative design in chemical compositions, structure, and morphology, and supports for the oxygen reaction.

The role of arginase in endothelial dysfunction

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194407 Year: Pages: 115 DOI: 10.3389/978-2-88919-440-7 Language: English
Publisher: Frontiers Media SA
Subject: Allergy and Immunology --- Medicine (General)
Added to DOAB on : 2016-02-05 17:24:33
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In recent years, an increasing number of manuscripts have been published addressing the deleterious role of arginase in endothelial dysfunction. ROS have been shown to play a crucial role in arginase activation, which in turn leads to eNOS dysfunction.

Origin and spatiotemporal dynamics of the peroxisomal endomembrane system

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194643 Year: Pages: 148 DOI: 10.3389/978-2-88919-464-3 Language: English
Publisher: Frontiers Media SA
Subject: Physiology --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
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The peroxisome is an organelle with essential roles in lipid metabolism, maintenance of reactive oxygen species homeostasis, and anaplerotic replenishment of tricarboxylic acid cycle intermediates destined for mitochondria. Peroxisomes constitute a dynamic endomembrane system. The homeostatic state of this system is upheld via two pathways for assembling and maintaining the diverse peroxisomal compartments constituting it; the relative contribution of each pathway to preserving such system may vary in different organisms and under various physiological conditions. One pathway begins with the targeting of certain peroxisomal membrane proteins to an endoplasmic reticulum template and their exit from the template via pre-peroxisomal carriers; these carriers mature into metabolically active peroxisomes containing the entire complement of membrane and matrix proteins. Another pathway operates via growth and maturation of pre-existing peroxisomal precursors that do not originate from the endoplasmic reticulum; mature peroxisomes proliferate by undergoing fission. Recent studies have uncovered new roles for the peroxisomal endomembrane system in orchestrating important developmental decisions and defining organismal longevity. This Frontiers Special Topic Issue is focused on the advances in our understanding of how evolutionarily distant organisms coordinate the formation, maturation, proliferation, maintenance, inheritance and quality control of the peroxisomal endomembrane system and how peroxisomal endomembranes communicate with other cellular compartments to orchestrate complex biological processes and various developmental programs from inside the cell.

ROS Regulation during Plant Abiotic Stress Responses

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889450541 Year: Pages: 306 DOI: 10.3389/978-2-88945-054-1 Language: English
Publisher: Frontiers Media SA
Subject: Botany --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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Plants are continuously exposed to a wide range of environmental conditions, including cold, drought, salt, heat, which have major impact on plant growth and development. To survive, plants have evolved complex physiological and biochemical adaptations to cope with a variety of adverse environmental stresses. Among them, reactive oxygen species (ROS) are key regulators and play pivotal roles during plant stress responses, which are thought to function as early signals during plant abiotic stress responses. ROS were long regarded as unwanted and toxic by-products of physiological metabolism. However, ROS are now recognized as central players in the complex signaling network of cells. Therefore, a fine-tuning control between ROS production and scavenging pathways is essential to maintain non-toxic levels in planta under stressful conditions through enzymatic and non-enzymatic antioxidant defense systems. We focus on the roles of ROS during plant abiotic stress responses in this Research Topic. Plant responses to multiple abiotic stresses and effects of hormones and chemicals on plant stress responses have been carefully studies. Although functions of several stress responsive genes have been characterized and possible interactions between hormones and ROS are discussed, future researches are needed to functionally characterize ROS regulatory and signaling transduction pathways.Plants are continuously exposed to a wide range of environmental conditions, including cold, drought, salt, heat, which have major impact on plant growth and development. To survive, plants have evolved complex physiological and biochemical adaptations to cope with a variety of adverse environmental stresses. Among them, reactive oxygen species (ROS) are key regulators and play pivotal roles during plant stress responses, which are thought to function as early signals during plant abiotic stress responses. ROS were long regarded as unwanted and toxic by-products of physiological metabolism. However, ROS are now recognized as central players in the complex signaling network of cells. Therefore, a fine-tuning control between ROS production and scavenging pathways is essential to maintain non-toxic levels in planta under stressful conditions through enzymatic and non-enzymatic antioxidant defense systems. We focus on the roles of ROS during plant abiotic stress responses in this Research Topic. Plant responses to multiple abiotic stresses and effects of hormones and chemicals on plant stress responses have been carefully studies. Although functions of several stress responsive genes have been characterized and possible interactions between hormones and ROS are discussed, future researches are needed to functionally characterize ROS regulatory and signaling transduction pathways.

Interplay between NO Signalling, ROS, and the Antioxidant System in Plants

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889450695 Year: Pages: 206 DOI: 10.3389/978-2-88945-069-5 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Botany --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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Over the last decades, nitric oxide (NO) has emerged as an essential player in redox signalling. Reactive oxygen species (ROS) also act as signals throughout all stages of plant life. Because they are potentially harmful for cellular integrity, ROS and NO levels must be tightly controlled, especially by the classical antioxidant system and additional redox-active metabolites and proteins. Recent work provided evidence that NO and ROS influence each other’s biosynthesis and removal. Moreover, novel signalling molecules resulting from the chemical reaction between NO, ROS and plant metabolites have been highlighted, including N2O3, ONOO-, NO2, S-nitrosoglutathione and 8-NO2 cGMP. They are involved in diverse plant physiological processes, the best characterized being stomata regulation and stress defense. Taken together, these new data demonstrate the complex interactions between NO, ROS signalling and the antioxidant system. This Frontiers in Plant Science Research Topic aims to provide an updated and complete overview of this important and rapidly expanding area through original article and detailed reviews.

Microenvironment-Derived Stem Cell Plasticity

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889453443 Year: Pages: 114 DOI: 10.3389/978-2-88945-344-3 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Biology --- Medicine (General) --- Allergy and Immunology
Added to DOAB on : 2018-02-27 16:16:45
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Plasticity is the hallmark of stem cells. At the same time, stem cells, like any other cell type, are influenced by their microenvironment and respond to it accordingly. A specific microenvironment is defined by a variety of factors, including biological and chemical factors, cell-cell interactions, but also metabolic and mechanical cues. Such dynamic and specialized microenvironment where the stem cells reside is considered a stem cell niche. Tissue injury as well as malignant tissue alterations lead to changes in the niche influencing the plasticity and biology of residing stem cells. Similarly, the niche changes upon tissue damage, which eventually induces differentiation of stem cells and ultimately regeneration of the tissue.

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