scholarly journals Mercury Exchange at the Air-Water-Soil Interface: An Overview of Methods

2002 ◽  
Vol 2 ◽  
pp. 1597-1602
Author(s):  
Fengman Fang ◽  
Qichao Wang ◽  
Ruhai Liu
Keyword(s):  
Soil Water ◽  
Current Knowledge ◽  
Terrestrial Ecosystems ◽  
Present Knowledge ◽  
Existing Problems ◽  
The Past ◽  
Emission Fluxes ◽  
Soil Interface ◽  
Soil And Water ◽  
Made In

An attempt is made to assess the present knowledge about the methods of determining mercury (Hg) exchange at the air-water-soil interface during the past 20 years. Methods determining processes of wet and dry removal/deposition of atmospheric Hg to aquatic and terrestrial ecosystems, as well as methods determining Hg emission fluxes to the atmosphere from natural surfaces (soil and water) are discussed. On the basis of the impressive advances that have been made in the areas relating to Hg exchange among air-soil-water interfaces, we analyzed existing problems and shortcomings in our current knowledge. In addition, some important fields worth further research are discussed and proposed.

Aspects of the geomorphology, genesis and environmental significance of earth hummocks (thúfur, pounus): miniature cryogenic mounds

2005 ◽  
Vol 29 (2) ◽  
pp. 139-155 ◽  
Author(s):  
Stefan Grab
Keyword(s):  
Current Knowledge ◽  
Thermal Characteristics ◽  
Environmental Research ◽  
Environmental Significance ◽  
Research Gaps ◽  
Frozen Ground ◽  
The Past ◽  
Internal Morphology ◽  
Differential Frost Heave ◽  
Made In

Miniature varieties of cryogenic mounds that are capable of forming in seasonally frozen ground are commonly referred to as earth hummocks (e.g., North America), thúfur (e.g., Greenland and Iceland) and pounus (Fennoscandia). Over the past few decades there has been a consistent interest to study earth hummocks from a variety of environmental settings. This review summarizes the current knowledge of earth hummocks, highlighting aspects on the external and internal morphology, and thermal characteristics, which may assist to explain hummock formation. Several hypotheses have been proposed for the genesis of earth hummocks, including the ‘cryoexpulsion’ of clasts, hydrostatic and cryostatic pressure, cellular circulation, and differential frost heave. These hypotheses are critically evaluated and some research gaps identified. It emerges that considerable advances have been made towards an improved understanding of earth hummock development, modification and disintegration. Much progress has been made in the application of earth hummock studies to a variety of environmental research approaches such as palaeoenvironmental reconstructions and assessing their impact on hillslope drainage.

Soil and water conservation on the Loess Plateau in China: review and perspective

2007 ◽  
Vol 31 (4) ◽  
pp. 389-403 ◽  
Author(s):  
Liding Chen ◽  
Wei Wei ◽  
Bojie Fu ◽  
Yihe Lü
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Loess Plateau ◽  
Water Conservation ◽  
Vegetation Restoration ◽  
Soil And Water Conservation ◽  
The Loess Plateau ◽  
The Past ◽  
Soil And Water ◽  
Made In

The Loess Plateau, China, has long been suffering from serious soil erosion. About 2000 years ago, larger areas were used for grain production and soil erosion was thus becoming severe with increase in human activity. Severe soil and water loss led to widespread land degradation. During the past decades, great efforts were made in vegetation restoration to reduce soil erosion. However, the efficiency of vegetation restoration was not as satisfactory as expected due to water shortage. China initiated another state-funded scheme, the `Grain-for-Green' project in 1999, on the Loess Plateau to reduce soil erosion and improve land quality. However, the control of soil erosion effectively by land-use modification raised problems. In this paper, the lessons and experiences regarding soil and water conservation in the Loess Plateau in the past decades are analysed first. Urgent problems are then elaborated, such as the contradiction between land resource and human population, shortage of water both in amount and tempospatial distribution for vegetation growth, weak awareness of the problems of soil conservation by local officials, and poor public participation in soil and water conservation. Finally, suggestions regarding soil and water conservation in the Loess Plateau are given. In order to control soil erosion and improve vegetation, a scientific and detailed land-use plan for the Loess Plateau has to be made, in the first instance, and then planning for wise use of water resources should be undertaken to control mass movement effectively and to improve land productivity. Methods of improving public awareness of environmental conservation and public involvement in vegetation rehabilitation are also important.

scholarly journals Tooth Bioengineering and Regenerative Dentistry

2019 ◽  
Vol 98 (11) ◽  
pp. 1173-1182 ◽  
Author(s):  
P.C. Yelick ◽  
P.T. Sharpe
Keyword(s):  
Tissue Engineering ◽  
Current Knowledge ◽  
Basic Research ◽  
Dental Tissue ◽  
Dental Tissues ◽  
The Past ◽  
Tremendous Progress ◽  
Regenerative Dentistry ◽  
Dental Tissue Engineering ◽  
Made In

Over the past 100 y, tremendous progress has been made in the fields of dental tissue engineering and regenerative dental medicine, collectively known as translational dentistry. Translational dentistry has benefited from the more mature field of tissue engineering and regenerative medicine (TERM), established on the belief that biocompatible scaffolds, cells, and growth factors could be used to create functional, living replacement tissues and organs. TERM, created and pioneered by an interdisciplinary group of clinicians, biomedical engineers, and basic research scientists, works to create bioengineered replacement tissues that provide at least enough function for patients to survive until donor organs are available and, at best, fully functional replacement organs. Ultimately, the goal of both TERM and regenerative dentistry is to bring new and more effective therapies to the clinic to treat those in need. Very recently, the National Institutes of Health/National Institute of Dental and Craniofacial Research invested $24 million over a 3-y period to create dental oral and craniofacial translational resource centers to facilitate the development of more effective therapies to treat edentulism and other dental-related diseases over the next decade. This exciting era in regenerative dentistry, particularly for whole-tooth tissue engineering, builds on many key successes over the past 100 y that have contributed toward our current knowledge and understanding of signaling pathways directing natural tooth and dental tissue development—the foundation for current strategies to engineer functional, living replacement dental tissues and whole teeth. Here we use a historical perspective to present key findings and pivotal advances made in the field of translational dentistry over the past 100 y. We will first describe how this process has evolved over the past 100 y and then hypothesize on what to expect over the next century.

scholarly journals Irrigation Scheduling for Agriculture in the United States: The Progress Made and the Path Forward

2020 ◽  
Vol 63 (5) ◽  
pp. 1603-1618
Author(s):  
Saleh Taghvaeian ◽  
Allan A. Andales ◽  
L. Niel Allen ◽  
Isaya Kisekka ◽  
Susan A. O’Shaughnessy ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Status ◽  
The United States ◽  
Irrigation Scheduling ◽  
Crop Modeling ◽  
Soil Water Status ◽  
The Past ◽  
Plant Characteristics ◽  
Scheduling Strategies ◽  
Made In

HighlightsThe progress made in agricultural irrigation scheduling in the past ten years and the current challenges are discussed.The main scientific scheduling strategies are based on soil water status, plant characteristics, and crop modeling.Challenges include large time and data requirements and availability of decision support systems.Opportunities include integration of scheduling strategies and demonstrating their effectiveness through local studies.Abstract. Irrigation scheduling is the process of determining the appropriate amount and timing of water application to achieve desired crop yield and quality, maximize water conservation, and minimize possible negative effects on the environment, such as nutrient leaching below the crop root zone. Effective irrigation scheduling has been shown to save water, save energy, and help agricultural producers achieve improved yields and quality. However, scientific irrigation scheduling methods generally have remained limited to mostly research applications with relatively low adoption by irrigators. There are several main approaches to irrigation scheduling, including those based on soil water status, plant characteristics, and/or crop modeling. Each of these approaches has advantages as well as limitations and sources of uncertainty and variability, depending on application conditions. This article summarizes progress made in the U.S. in each of the main scheduling approaches in the past ten years (since the 2010 Decennial Irrigation Symposium) and existing challenges and opportunities that should be considered moving forward. This article is intended to guide future research and extension projects in improving adoption of scientific irrigation scheduling approaches. Keywords: Computer modeling, Plant characteristics, Soil water status.

Actinobacillus pleuropneumoniaevaccines: from bacterins to new insights into vaccination strategies

2008 ◽  
Vol 9 (1) ◽  
pp. 25-45 ◽  
Author(s):  
Mahendrasingh Ramjeet ◽  
Vincent Deslandes ◽  
Julien Gouré ◽  
Mario Jacques
Keyword(s):  
Bacterial Infections ◽  
Current Knowledge ◽  
Economic Losses ◽  
Swine Industry ◽  
Porcine Pleuropneumonia ◽  
Vaccination Strategies ◽  
The Past ◽  
Genomic Tools ◽  
Potential Vaccine ◽  
Made In

AbstractWith the growing emergence of antibiotic resistance and rising consumer demands concerning food safety, vaccination to prevent bacterial infections is of increasing relevance.Actinobacillus pleuropneumoniaeis the etiological agent of porcine pleuropneumonia, a respiratory disease leading to severe economic losses in the swine industry. Despite all the research and trials that were performed withA. pleuropneumoniaevaccination in the past, a safe vaccine that offers complete protection against all serotypes has yet not reached the market. However, recent advances made in the identification of new potential vaccine candidates and in the targeting of specific immune responses, give encouraging vaccination perspectives. Here, we review past and current knowledge onA. pleuropneumoniaevaccines as well as the newly available genomic tools and vaccination strategies that could be useful in the design of an efficient vaccine againstA. pleuropneumoniaeinfection.

The molecular biology of temperature-dependent sex determination

1995 ◽  
Vol 350 (1333) ◽  
pp. 297-304 ◽  
Keyword(s):  
Sex Determination ◽  
Molecular Basis ◽  
Current Knowledge ◽  
Temperature Dependent ◽  
The Past ◽  
Egg Incubation ◽  
Heteromorphic Sex Chromosomes ◽  
Substantial Progress ◽  
Common Molecular Basis ◽  
Made In

Many reptiles do not have heteromorphic sex chromosomes and for these species sex is determined during embryogenesis by the temperature of egg incubation rather than at conception. The phenomenon of temperature- dependent sex determination (TSD) was discovered almost thirty years ago, but few advances have been made towards the elucidation of its mechanism. In the past few years substantial progress has been made in the understanding of the molecular basis of XY chromosomal (genetic) sex determination (GSD) through the discovery of SRY. It is now possible to start comparing TSD with GSD. TSD is found in some evolutionarily ancient vertebrates and has been postulated to be the ancestral process from which GSD has evolved. If this is true then the two mechanisms may share a common molecular basis. This paper details the current knowledge of GSD, our progress on the investigation of the involvement of SRY-type proteins, and finally presents some of the problems that need to be resolved to gain an understanding of the molecular basis of TSD.

scholarly journals Polysaccharide Biosynthesis: Glycosyltransferases and Their Complexes

2021 ◽  
Vol 12 ◽  
Author(s):  
Olga A. Zabotina ◽  
Ning Zang ◽  
Richard Weerts
Keyword(s):  
Protein Interactions ◽  
High Efficiency ◽  
Current Knowledge ◽  
Protein Protein Interactions ◽  
Acceptor Substrate ◽  
Plant Polysaccharide ◽  
Polysaccharide Biosynthesis ◽  
The Past ◽  
Genes Encoding ◽  
Made In

Glycosyltransferases (GTs) are enzymes that catalyze reactions attaching an activated sugar to an acceptor substrate, which may be a polysaccharide, peptide, lipid, or small molecule. In the past decade, notable progress has been made in revealing and cloning genes encoding polysaccharide-synthesizing GTs. However, the vast majority of GTs remain structurally and functionally uncharacterized. The mechanism by which they are organized in the Golgi membrane, where they synthesize complex, highly branched polysaccharide structures with high efficiency and fidelity, is also mostly unknown. This review will focus on current knowledge about plant polysaccharide-synthesizing GTs, specifically focusing on protein-protein interactions and the formation of multiprotein complexes.

scholarly journals The spectrum of the flame of carbon disulphide

1931 ◽  
Vol 132 (819) ◽  
pp. 310-330 ◽  
Keyword(s):  
Continuous Spectrum ◽  
Carbon Disulphide ◽  
Present Knowledge ◽  
The Other ◽  
The Past ◽  
Other Hand ◽  
Band Spectra ◽  
Made In

The present investigation of the spectrum of the flame of carbon disulphide was undertaken in the hope that further light might be thrown on the process of combustion of this substance. Extensive experiments have been made in the past, chiefly relating to explosions of mixtures of carbon disulphide and other gases, but a perusal of the literature suggests that the nature of the reactions which take place in such experiments, or in the ordinary flame itself, is still somewhat obscure. In connection with such experiments as have been made by chemists, the only reference to observations with the spectroscope seems to be that made by Dixon and Russell, who stated that when CS 2 was burnt in a Smithell’s flame separator, an apparently continuous spectrum was yielded by both the inner and outer cones. On the other hand, the spectrum of the CS 2 flame has been described by several spectroscopists, but the records have been incomplete and further observations seemed to be desirable. In particular, observations over a greater range of spectrum seemed to be necessary, as well as more exact measurements of the bands already known to be emitted. With such extended observations it appeared possible that our present knowledge of the band spectra associated with molecules of sulphur and carbon, and some of their compounds, might aid in tracing the reactions which precede the formation of the final products of combustion.

South Asian Developmental Crisis (Review Article)

1973 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
Rafiq Ahmad
Keyword(s):  
Second World War ◽  
World War ◽  
The Past ◽  
The Great Depression ◽  
Political Independence ◽  
Integrated Theory ◽  
Pass Through ◽  
Developed World ◽  
Second World ◽  
Made In

Like nations and civilizations, sciences also pass through period of crises when established theories are overthrown by the unpredictable behaviour of events. Economics is passing through such a crisis. The challenge thrown by the Great Depression of early 1930s took a decade before Keynes re-established the supremacy of economics. But this supremacy has again been upset by the crisis of poverty in the vast under-developed world which attained political independence after the Second World War. Poverty had always existed but never before had it been of such concern to economists as during the past twenty five years or so. Economic literature dealing with this problem has piled up but so have the agonies of poverty. No plausible and well-integrated theory of economic development or under-development has emerged so far, though brilliant advances have been made in isolated directions.

Mass Spectrometry Techniques: Principles and Practices for Quantitative Proteomics

2020 ◽  
Vol 21 ◽  
Author(s):  
Rocco J. Rotello ◽  
Timothy D. Veenstra
Keyword(s):  
Mass Spectrometry ◽  
Quantitative Proteomics ◽  
Protein Identification ◽  
Dynamic Nature ◽  
Complete Coverage ◽  
The Past ◽  
Proteome Level ◽  
A Cell ◽  
Quantitative Changes ◽  
Made In

: In the current omics-age of research, major developments have been made in technologies that attempt to survey the entire repertoire of genes, transcripts, proteins, and metabolites present within a cell. While genomics has led to a dramatic increase in our understanding of such things as disease morphology and how organisms respond to medications, it is critical to obtain information at the proteome level since proteins carry out most of the functions within the cell. The primary tool for obtaining proteome-wide information on proteins within the cell is mass spectrometry (MS). While it has historically been associated with the protein identification, developments over the past couple of decades have made MS a robust technology for protein quantitation as well. Identifying quantitative changes in proteomes is complicated by its dynamic nature and the inability of any technique to guarantee complete coverage of every protein within a proteome sample. Fortunately, the combined development of sample preparation and MS methods have made it capable to quantitatively compare many thousands of proteins obtained from cells and organisms.

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