460 research outputs found

    Spatial variability of soil salinity in Bohai Sea coastal wetlands, China: Partition into four management zones

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    Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0-30, 30-60 and 60-100cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland.Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0-30, 30-60 and 60-100cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland

    Application of microfluidic chips in anticancer drug screening

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    With the continuous development of drug screening technology, new screening methodologies and technologies are constantly emerging, driving drug screening into rapid, efficient and high-throughput development. Microfluidics is a rising star in the development of innovative approaches in drug discovery. In this article, we summarize the recent years' progress of microfluidic chip technology in drug screening, including the developmental history, structural design, and applications in different aspects of microfluidic chips on drug screening. Herein, the existing microfluidic chip screening platforms are summarized from four aspects: chip structure design, sample injection and drive system, cell culture technology on a chip, and efficient remote detection technology. Furthermore, this review discusses the application and developmental prospects of using microfluidic chips in drug screening, particularly in screening natural product anticancer drugs based on chemical properties, pharmacological effects, and drug cytotoxicity.Peer reviewe

    Research in Biological Control of the Formosan Subterranean Termite

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    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is a worldwide distributed pest of wooden structures and living plants that causes huge economic losses. Compared to chemical pesticides, biological control may provide a more environmentally friendly and persistent method for the control of C. formosanus. In this research, a series of studies were conducted to understand the termite-pathogen interaction and to develop a feasible biological control strategy. In the first part of the research, the toxicity of Bt toxins expressed by genetically modified maize to termites was tested. Plant tissues or extracts of three commercially planted Bt maize and two non-Bt maize were provided to termites as food. The results revealed no significant difference in survival rate, food consumption or length of tunnels among termites feeding on Bt and non-Bt maize. The following experiments show that maize cob can be used as a termite bait matrix. In the second part of the research, the susceptibility of C. formosanus to MosquitoDunks®, which contains about 10% of the entomopathogenic bacterium, Bacillus thuringiensis subspecies israelensis, was tested. No-choice and choice bioassays did not show a promising lethal effect of MosquitoDunks® on termites. Furthermore it was shown that C. formosanus can suppress the growth of B. thuringiensis. Also, clay was tested for its potential to be a termite bait matrix that can be used to encapsulate biological control agents. Choice tests showed that significantly more termites aggregated in chambers where clay was provided, indicating the possibility of clay to be used as a termite attractant. In the third part of the research, the potential to combine a biological control agent and a chemical pesticide against termites was investigated. The effect of low concentrations of lufenuron, a chitin synthesis inhibitor, on termite physiology and behavior was tested. Results showed that lufenuron significantly reduced vigor and disease resistance of termites. In the following experiments, termite mortality was significantly higher and synergistic in the combination of lufenuron and Pseudomonas aeruginosa (Schroeter) compared to treatment of lufenuron or P. aeruginosa alone. To combine lufenuron and a termite pathogen may bring a successful IPM strategy for the control of termites

    The Insecticidal Bacterial Toxins in Modern Agriculture

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    Increased awareness about environmental adverse effects of human activities has prompted the use of insecticides with low impact on systems associated to agriculture. Currently, the most successful biological products are based on protein toxins from the bacterial species Bacillus thuringiensis. Because of the remarkable properties of these proteins, their encoding genes were introduced into farming species (the so called Bt-crops), in such a way, that these plants are self-protected against some key insect pests. Despite the fact that a relatively large number of these toxins, with different toxicity ranges, have been described, it is still important to find new resources with novel capabilities to complement, or to replace in the future, the currently used ones. On another hand, it is important to continue studying their mode action in susceptible insects, and the changes occurred in resistant ones, to determine the most effective strategy for long lasting pest control. The focus of this Special Issue of Toxins is to provide updated information on the use of B. thuringiensis and their toxins on different field crops, the interactions of these toxins with other molecules, analyze the biochemical and molecular basis of emerging cases of resistance and, in general, to provide information which can contribute to an effective pest management with these toxins

    Nutrient Cycling in Forest Ecosystems

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    The long-term productivity of forest ecosystems depends on the cycling of nutrients. The effect of carbon dioxide fertilization on forest productivity may ultimately be limited by the rate of nutrient cycling. Contemporary and future disturbances such as climatic warming, N-deposition, deforestation, short rotation sylviculture, fire (both wild and controlled), and the invasion of exotic species all place strains on the integrity of ecosystem nutrient cycling. Global differences in climate, soils, and species make it difficult to extrapolate even a single important study worldwide. Despite advances in the understanding of nutrient cycling and carbon production in forests, many questions remain. The chapters in this volume reflect many contemporary research priorities. The thirteen studies in this volume are arranged in the following subject groups: • N and P resorption from foliage worldwide, along chronosequences and along elevation gradients; • Litter production and decomposition; • N and P stoichiometry as affected by N deposition, geographic gradients, species changes, and ecosystem restoration; • Effects of N and P addition on understory biomass, litter, and soil; • Effects of burning on soil nutrients; • Effects of N addition on soil fauna

    Advances in Molecular Breeding of Vegetable Crops

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    Vegetable crops provide valuable minerals and vitamins that are indispensible for human health. Scientists have been working on the genetics of vegetable crops, deciphering the molecular bases of agronomically important traits. These genetic bases and variations in vegetable traits will greatly facilitate vegetable genetic improvement. Therefore, the genes of and genetic research on vegetable crops are of great importance. This Special Issue is a collection of 13 important research papers addressing the genes, genetics, and breeding of major vegetable crops. In the present book, the authors described the genes and QTLs responsible for stress tolerance, disease resistance, vegetable yield, and quality. The 13 research papers cover germplasm enhancement and evaluation, QTL mapping, gene isolation, marker development, and gene expression as well as gene editing in a wide range of vegetable species, including broccoli, pepper, eggplant, onion, and Cucurbita species. Readers from all over the globe are expected to greatly benefit from this Special Issue collection regarding their own work and the goal of improving breeding efficiency with molecular breeding to generate environment-adaptive, high-yield, and high-quality vegetable crops with which to feed the global population of 9.7 billion in an extreme climate by 2050

    Assessing Atmospheric Pollution and Its Impacts on the Human Health

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    This reprint contains articles published in the Special Issue entitled "Assessing Atmospheric Pollution and Its Impacts on the Human Health" in the journal Atmosphere. The research focuses on the evaluation of atmospheric pollution by statistical methods on the one hand, and on the other hand, on the evaluation of the relationship between the level of pollution and the extent of its effect on the population's health, especially on pulmonary diseases

    Sustainable Cropping Systems

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    Global crop production must substantially increase to meet the needs of a rapidly growing population. This is constrained by the availability of nutrients, water, and land. There is also an urgent need to reduce the negative environmental impacts of crop production. Collectively, these issues represent one of the greatest challenges of the twenty-first century. Sustainable cropping systems based on ecological principles are the core of integrated approaches to solve this critical challenge. This special issue provides an international basis for revealing the underlying mechanisms of sustainable cropping systems to drive agronomic innovations. It includes review and original research articles that report novel scientific findings on improvement in cropping systems related to crop yields and their resistance to biotic and abiotic stressors, resource use efficiency, environmental impact, sustainability, and ecosystem services

    Afforestation and Reforestation: Drivers, Dynamics, and Impacts

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    Afforestation/reforestation (or forestation) has been implemented worldwide as an effective measure towards sustainable ecosystem services and addresses global environmental problems such as climate change. The conversion of grasslands, croplands, shrublands, or bare lands to forests can dramatically alter forest water, energy, and carbon cycles and, thus, ecosystem services (e.g., carbon sequestration, soil erosion control, and water quality improvement). Large-scale afforestation/reforestation is typically driven by policies and, in turn, can also have substantial socioeconomic impacts. To enable success, forestation endeavors require novel approaches that involve a series of complex processes and interdisciplinary sciences. For example, exotic or fast-growing tree species are often used to improve soil conditions of degraded lands or maximize productivity, and it often takes a long time to understand and quantify the consequences of such practices at watershed or regional scales. Maintaining the sustainability of man-made forests is becoming increasingly challenging under a changing environment and disturbance regime changes such as wildland fires, urbanization, drought, air pollution, climate change, and socioeconomic change. Therefore, this Special Issue focuses on case studies of the drivers, dynamics, and impacts of afforestation/reforestation at regional, national, or global scales. These new studies provide an update on the scientific advances related to forestation. This information is urgently needed by land managers and policy makers to better manage forest resources in today’s rapidly changing environments

    World Cotton Germplasm Resources

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    Preservation of plant germplasm resources is vitally important for mankind to supply food and product security in the globalization and technological advances of the 21st century. Mankind preserved a wealth of available genetic resources of many plant species worldwide. One of the such worldwide plant germplasm resources is available for cotton, a unique natural fiber producing cash crop for mankind. Worldwide cotton germplasm collections exist in Australia, Brazil, China, India, France, Pakistan, Turkey, Russia, United States of America, and Uzbekistan. The objective of World Cotton Germplasm Resources book is to present readers with updated information on existing cotton germplasm resources, highlighting detailed inventory, description, storage conditions, characterization and utilization as well as challenges and perspectives. This book should be a comprehensive encyclopedic reading source for plant research community and students to gather important information on worldwide cotton germplasm resources
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