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Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889450817 Year: Pages: 242 DOI: 10.3389/978-2-88945-081-7 Language: English
Publisher: Frontiers Media SA
Subject: Chemistry (General) --- Geography --- Oceanography --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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A substantial increase in the number of studies using the optical properties (absorbance and fluorescence) of dissolved organic matter (DOM) as a proxy for its chemical properties in estuaries and the coastal and open ocean has occurred during the last decade. We are making progress on finding the actual chemical compounds or phenomena responsible for DOM’s optical properties. Ultrahigh resolution mass spectrometry, in particular, has made important progress in making the key connections between optics and chemistry. But serious questions remain and the last major special issue on DOM optics and chemistry occurred nearly 10 years ago. Controversies remain from the non-specific optical properties of DOM that are not linked to discrete sources, and sometimes provide conflicting information. The use of optics, which is relatively easier to employ in synoptic and high resolution sampling to determine chemistry, is a critical connection to make and can lead to major advances in our understanding of organic matter cycling in all aquatic ecosystems. The contentions and controversies raised by our poor understanding of the linkages between optics and chemistry of DOM are bottlenecks that need to be addressed and overcome.

Quantitative Biology: Dynamics of Living Systems

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889452132 Year: Pages: 136 DOI: 10.3389/978-2-88945-213-2 Language: English
Publisher: Frontiers Media SA
Subject: Biology --- Neurology --- Physiology --- Science (General)
Added to DOAB on : 2017-10-13 14:57:01
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With the emergence of Systems Biology, there is a greater realization that the whole behavior of a living system may not be simply described as the sum of its elements. To represent a living system using mathematical principles, practical quantities with units are required. Quantities are not only the bridge between mathematical description and biological observations; they often stand as essential elements similar to genome information in genetics. This important realization has greatly rejuvenated research in the area of Quantitative Biology. Because of the increased need for precise quantification, a new era of technological development has opened. For example, spatio-temporal high-resolution imaging enables us to track single molecule behavior in vivo. Clever artificial control of experimental conditions and molecular structures has expanded the variety of quantities that can be directly measured. In addition, improved computational power and novel algorithms for analyzing theoretical models have made it possible to investigate complex biological phenomena. This research topic is organized on two aspects of technological advances which are the backbone of Quantitative Biology: (i) visualization of biomolecules, their dynamics and function, and (ii) generic technologies of model optimization and numeric integration. We have also included articles highlighting the need for new quantitative approaches to solve some of the long-standing cell biology questions. In the first section on visualizing biomolecules, four cutting-edge techniques are presented. Ichimura et al. provide a review of quantum dots including their basic characteristics and their applications (for example, single particle tracking). Horisawa discusses a quick and stable labeling technique using click chemistry with distinct advantages compared to fluorescent protein tags. The relatively small physical size, stability of covalent bond and simple metabolic labeling procedures in living cells provides this type of technology a potential to allow long-term imaging with least interference to protein function. Obien et al. review strategies to control microelectrodes for detecting neuronal activity and discuss techniques for higher resolution and quality of recordings using monolithic integration with on-chip circuitry. Finally, the original research article by Amariei et al. describes the oscillatory behavior of metabolites in bacteria. They describe a new method to visualize the periodic dynamics of metabolites in large scale cultures populations. These four articles contribute to the development of quantitative methods visualizing diverse targets: proteins, electrical signals and metabolites. In the second section of the topic, we have included articles on the development of computational tools to fully harness the potential of quantitative measurements through either calculation based on specific model or validation of the model itself. Kimura et al. introduce optimization procedures to search for parameters in a quantitative model that can reproduce experimental data. They present four examples: transcriptional regulation, bacterial chemotaxis, morphogenesis of tissues and organs, and cell cycle regulation. The original research article by Sumiyoshi et al. presents a general methodology to accelerate stochastic simulation efforts. They introduce a method to achieve 130 times faster computation of stochastic models by applying GPGPU. The strength of such accelerated numerical calculation are sometimes underestimated in biology; faster simulation enables multiple runs and in turn improved accuracy of numerical calculation which may change the final conclusion of modeling study. This also highlights the need to carefully assess simulation results and estimations using computational tools.

Fluorescence Probes for Sensing

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ISBN: 9783038429272 9783038429289 Year: Pages: VIII, 306 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Environmental Sciences
Added to DOAB on : 2018-05-08 13:04:30
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The rapid progress in sensor science in recent years has resulted in the development of fluorescence probes with enhanced analytical capabilities. Because of the vast evolution of this research field, therefore, we have decided to combine all the research articles published in "Fluorescence Probes and Sensors" for a Special Issue (SI) book of Sensors which was focusing on the important role sensors play in “Fluorescent Probes and Sensors”. Fluorescence novel Probes make an ideal candidate for promising applications in biological analytes and environmental monitoring. Fluorescent probes along with metal complexes have been developed as a new class of fluorophores with excellent properties. This book illustrating the suitability of newly developed sensors for fluorescent analysis applications, as well as describing novel applications of established sensors in solving real life analytical problems.

Molecular Organization of Membranes: Where Biology Meets Biophysics

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889454099 Year: Pages: 150 DOI: 10.3389/978-2-88945-409-9 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Biology
Added to DOAB on : 2018-11-16 17:17:57
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Biological membranes protect cells and organelles from the surrounding environment, but serve also as organising platforms for physiological processes such as cell signalling. The hydrophobic core of membranes is composed of lipids and proteins influencing each other. Local membrane composition and properties define its molecular organisation and, in this way, regulate the function of all associated molecules. Therefore, studying interactions of components, biophysical properties and overall membrane dynamics provides essential information on its function in the context of cell activities. Such knowledge can contribute to biomedical fields such as pharmacology, immunology, neurobiology and many others. The goal of the Research Topic entitled ‘Molecular organisation of membranes: where biology meets biophysics’ was to provide a comprehensive platform for publishing articles, reviews and opinions focused on membrane organisation and the forces behind its heterogeneous and dynamic structure. We collected 11 works which cover topics as diverse as general membrane organisation models, membrane trafficking and signalling regulation, biogenesis of caveolae, protein-lipid interactions and the importance of membrane-associated tetraspanins networks. The prevalent theme was the existence of membrane nanodomains. To this point, new emerging technologies are presented which own the power to bring a novel insight on how membrane nanodomains are formed and maintained and what is their function. We believe that the collection of works in this Research Topic brings forward some important questions which will stimulate further research in this difficult but exciting field.

Gas transfer at the air-water interface in a turbulent flow environment

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Book Series: Dissertationsreihe am Institut für Hydromechanik der Universität Karlsruhe (TH) ISSN: 14394111 ISBN: 3937300740 Year: Volume: 2005,4 Pages: IX, 128 p. DOI: 10.5445/KSP/1000003544 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: General and Civil Engineering
Added to DOAB on : 2019-07-30 20:01:58
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The gas transfer process across the air-water interface in a ottom-shear-induced turbulent environment was investigated to gain improved fundamental understanding of the physical mechanisms that control the process. For this purpose, it is necessary to reveal the hydrodynamics of the flow field as well as the molecular diffusion and the turbulent transport contributions to the total flux. Therefore, detailed laboratory experiments were conducted to obtain these information.The experiments were performed in a grid-stirred tank using a combined Particle Image Velocimetry - Laser Induced Fluorescence (PIV-LIF) technique that has been developed for these near surface gas transfer measurements. The turbulence characteristics of the velocity near the interface were acquired from the PIV measurements and showed generally good agreement with the theoretical profiles from Hunt & Graham (1978). The LIF technique enabled visualization of the planar concentration fields which provided more insight into the gas transfer mechanisms. The high data resolution allowed detailed quantification of the concentration distribution within the thin aqueous boundary layer. The mean and turbulent fluctuation characteristics of the concentration could be elucidated and the molecular diffusion contribution to the total flux across the interface could be determined. With the combined PIV-LIF technique, which enables simultaneous and spatially synoptic measurements of 2D velocity and concentration fields, the turbulent mass flux term cw and also the total mass flux across the air-water interface could be quantified directly. For the first time, a particular trend can be inferred from the measured mean cw profiles. It could also be shown that the contribution of the turbulent mass flux to the total gas flux is significant. The co-spectra indicated different behavior for the cases with lower and higher turbulent Reynolds numbers.The interrelated interpretation of the obtained results suggest that the gas transfer process is controlled by a spectrum of different eddy sizes and the gas transfer at different turbulence levels can be associated to certain eddy sizes. For high turbulence levels the gas transfer should be asymptotic to the small eddy model, whereas for low turbulence level to the large eddy model. The new results of turbulent mass flux should aid as an excellent database in refining numerical models and developing more accurate models for the prediction of the transfer velocity.

Replication-Competent Reporter-Expressing Viruses

ISBN: 9783038422587 9783038422594 Year: Pages: XVI, 322 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biology
Added to DOAB on : 2016-10-31 16:58:45
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Recombinant viruses expressing reporter fluorescent or bioluminescent proteins are an excellent option to evaluate the dynamics of viral infection progression in both cultured cells and/or validated animal models of viral infection. Reporter proteins are valid surrogates for direct detection of infected cells in vitro and in vivo, without the use of secondary methodologies to identify infected cells. By eliminating the need of secondary labeling, tractable replicating-competent, reporter-expressing viruses provide an ideal approach to monitor viral infections in real time, representing a significant advance in the study of the biology of viruses, to evaluate vaccination approaches, and to identify new therapeutics against viral infections using high-throughput screening settings. In this Special Issue “Replication-Competent Reporter-Expressing Viruses” we review replication-competent, reporter-expressing viruses belonging to different families, methods of characterization, and applications to facilitate the study of in vitro and in vivo viral infections. We also seek to discuss disadvantages and limitations associated with these reporter-expressing viruses. Finally, we provide rational future perspectives and additional avenues for the development, characterization, and applications of recombinant, reporter-expressing, competent viruses.

Neue Perspektiven für geochemische Untersuchungen von neolithischen Steingeräten. Ein Methodenvergleich zwischen portabler energiedispersiver Röntgenfluoreszenzanalyse (P-ED-RFA) und wellenlängendispersiver Röntgenfluoreszenzanalyse (WD-RFA) am Beispiel von bandkeramischen Dechselklingen aus Diemarden (Südniedersachsen)

Authors: ---
ISBN: 9783943423051 Year: Pages: 130 DOI: 10.15460/HUP.129 Language: German
Publisher: Hamburg University Press
Subject: History
Added to DOAB on : 2019-01-15 13:33:22

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Shoe-last celts (Dechselklingen) are characteristic legacies of the -iddle European Old and Middle Neolithic. They are important sources of economic and social archaeological investigations. This requires the determination of the used raw materials and their origin. In recent years, extensive geochemical and petrographic investigations of interchangeable blades have been carried out. Within the scope of various projects, a database with geochemical analyses of wmuch more than 500 blades and raw material pieces has been created. The analyses were all generated by wavelength dispersive X-ray fluorescence analysis (WD-RFA). The petrographic and geochemical examination was always accompanied by a sampling of the investigated pieces, which resulted in more or less severe damage to the artifacts. The portable energy dispersive X-ray fluorescence analysis (P-ED-RFA), which has recently been used in archaeometric ceramic analysis, can non-destructiveally determine the geochemical composition of vascular ceramics. In contrast to all the methods used so far, the sample does not have to be prepared in the laboratory, but can be carried out directly on site in a relatively short time. Thus, a time- and thus cost-effective procedure is available.

Analysis of Peptides and Proteins by Electrophoretic Techniques

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ISBN: 9783039212279 / 9783039212286 Year: Pages: 110 DOI: 10.3390/books978-3-03921-228-6 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-08-28 11:21:27
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The characterization of peptides and proteins is central to understanding their function and expression in biological matrices. Moreover, these macromolecules are important biomarkers of many human diseases. In recent years, the performance of separation techniques based on electromigration have significantly increased. The development of microdevices has reduced sample consumption and waste production while high-sensitivity detectors, such as mass spectrometry (MS) or laser-induced fluorescence (LIF), have significantly improved with regards to separation efficiency and detection limits. All of these advancements have led to appreciably enlarged fields of application. Nowadays, a multitude of studies using separation techniques based on electromigration to study proteins and peptides from numerous real matrices are available in the literature. This Special Issue covers the most recent knowledge and advances in the study of peptides and proteins using several electrophoresis techniques, as well as the characterization of relevant proteins and peptides in application areas such as clinical studies, functional foods, and toxicology.

Plasmonics and its Applications

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ISBN: 9783038979142 / 9783038979159 Year: Pages: 196 DOI: 10.3390/books978-3-03897-915-9 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General)
Added to DOAB on : 2019-06-26 08:44:06
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Plasmonics is a rapidly developing field that combines fundamental research and applications ranging from areas such as physics to engineering, chemistry, biology, medicine, food sciences, and the environmental sciences. Plasmonics appeared in the 1950s with the discovery of surface plasmon polaritons. Plasmonics then went through a novel propulsion in the mid-1970s, when surface-enhanced Raman scattering was discovered. Nevertheless, it is in this last decade that a very significant explosion of plasmonics and its applications has occurred. Thus, this book provides a snapshot of the current advances in these various areas of plasmonics and its applications, such as engineering, sensing, surface-enhanced fluorescence, catalysis, and photovoltaic devices.

Biological and Biogenic Crystallization

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ISBN: 9783038975212 Year: Pages: 106 DOI: 10.3390/books978-3-03897-522-9 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology
Added to DOAB on : 2019-03-08 11:42:05
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The intention of the Special Issue ""Biological and Biogenic Crystallization"" was to create an international platform aimed at covering a broad field of results involving the crystallization of biological molecules, including virus and protein crystallization, biogenic crystallization including physiological and pathological crystallization taking place in living organisms (human beings, animals, plants, bacteria, etc.), and bio-inspired crystallization. Despite many years of research on biological and biogenic crystals, there are still open questions as well as hot and timely topics. This Special Issue contains seven articles that present a cross-section of the current research activities in the of field of biological and biogenic crystals. The authors of the presented articles prove the vibrant and topical nature of this field. We hope that this Special Issue will serve as a source of inspiration for future investigations, and will be useful for scientists and researchers who work on the exploration of biological and biogenic crystals.

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