Periodicals
Adaptive Environmental Assessment and Management
[no abstract]
Agriculture• 1980• Oxford University Press
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Periodicals
Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations
Nanomaterials (NMs) have gained prominence in technological advancements due to their tunable physical, chemical and biological properties with enhanced performance over their bulk counterparts. NMs are categorized depending on their size, composition, shape, and origin. The ability to predict the unique properties of NMs increases the value of each classification. Due to increased growth of production of NMs and their industrial applications, issues relating to toxicity are inevitable. The aim of this review is to compare synthetic (engineered) and naturally occurring nanoparticles (NPs) and nanostructured materials (NSMs) to identify their nanoscale properties and to define the specific knowledge gaps related to the risk assessment of NPs and NSMs in the environment. The review presents an overview of the history and classifications of NMs and gives an overview of the various sources of NPs and NSMs, from natural to synthetic, and their toxic effects towards mammalian cells and tissue. Additionally, the types of toxic reactions associated with NPs and NSMs and the regulations implemented by different countries to reduce the associated risks are also discussed.
Agriculture• 2018• Beilstein Institute for the Advancement of Chemical Sciences
Periodicals
The Effect of Credit Market Competition on Lending Relationships
This paper provides a simple framework showing that the extent of competition in credit markets is important in determining the value of lending relationships. Creditors are more likely to finance credit-constrained firms when credit markets are concentrated because it is easier for these creditors to internalize the benefits of assisting the firms. The paper offers evidence from small business data in support of this hypothesis.
Agriculture• 1995• Oxford University Press
Periodicals
Shifting the limits in wheat research and breeding using a fully annotated reference genome
An annotated reference sequence representing the hexaploid bread wheat genome in 21 pseudomolecules has been analyzed to identify the distribution and genomic context of coding and noncoding elements across the A, B, and D subgenomes. With an estimated coverage of 94% of the genome and containing 107,891 high-confidence gene models, this assembly enabled the discovery of tissue- and developmental stage-related coexpression networks by providing a transcriptome atlas representing major stages of wheat development. Dynamics of complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. This community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding.
Agriculture• 2018• American Association for the Advancement of Science
Periodicals
Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being
Distributions of Earth's species are changing at accelerating rates, increasingly driven by human-mediated climate change. Such changes are already altering the composition of ecological communities, but beyond conservation of natural systems, how and why does this matter? We review evidence that climate-driven species redistribution at regional to global scales affects ecosystem functioning, human well-being, and the dynamics of climate change itself. Production of natural resources required for food security, patterns of disease transmission, and processes of carbon sequestration are all altered by changes in species distribution. Consideration of these effects of biodiversity redistribution is critical yet lacking in most mitigation and adaptation strategies, including the United Nation's Sustainable Development Goals.
Agriculture• 2017• American Association for the Advancement of Science
Periodicals
Paris Agreement climate proposals need a boost to keep warming well below 2 °C
[no abstract]
Agriculture• 2016• Nature Portfolio
Periodicals
Do Domestic Firms Benefit from Direct Foreign Investment? Evidence from Venezuela
Governments often promote inward foreign investment to encourage technology “spillovers” from foreign to domestic firms. Using panel data on Venezuelan plants, we find that foreign equity participation is positively correlated with plant productivity (the “own-plant” effect), but this relationship is only robust for small enterprises. We then test for spillovers from joint ventures to plants with no foreign investment. Foreign investment negatively affects the productivity of domestically owned plants. The net impact of foreign investment, taking into account these two offsetting effects, is quite small. The gains from foreign investment appear to be entirely captured by joint ventures. (JEL F2, O1, O3).
Agriculture• 1999• American Economic Association
Periodicals
Statistical estimations in enzyme kinetics
Although elementary statistical methods such as the calculation of means and their standard errors are commonly employed, application of the statistical methods of regression analysis in enzyme kinetic studies has received little attention. In estimating the kinetic parameters of the Michaelis-Menten equation, for instance, graphical methods such as the double-reciprocal plot (Lineweaver & Burk, 1934) are generally used, without supple- mentary statistical calculations. These methods have been reviewed by Dixon & Webb (1958).
Agriculture• 1961• Portland Press
Periodicals
Yield Trends Are Insufficient to Double Global Crop Production by 2050
Several studies have shown that global crop production needs to double by 2050 to meet the projected demands from rising population, diet shifts, and increasing biofuels consumption. Boosting crop yields to meet these rising demands, rather than clearing more land for agriculture has been highlighted as a preferred solution to meet this goal. However, we first need to understand how crop yields are changing globally, and whether we are on track to double production by 2050. Using ∼2.5 million agricultural statistics, collected for ∼13,500 political units across the world, we track four key global crops-maize, rice, wheat, and soybean-that currently produce nearly two-thirds of global agricultural calories. We find that yields in these top four crops are increasing at 1.6%, 1.0%, 0.9%, and 1.3% per year, non-compounding rates, respectively, which is less than the 2.4% per year rate required to double global production by 2050. At these rates global production in these crops would increase by ∼67%, ∼42%, ∼38%, and ∼55%, respectively, which is far below what is needed to meet projected demands in 2050. We present detailed maps to identify where rates must be increased to boost crop production and meet rising demands.
Agriculture• 2013• Public Library of Science
Periodicals
Drought under global warming: a review
Abstract This article reviews recent literature on drought of the last millennium, followed by an update on global aridity changes from 1950 to 2008. Projected future aridity is presented based on recent studies and our analysis of model simulations. Dry periods lasting for years to decades have occurred many times during the last millennium over, for example, North America, West Africa, and East Asia. These droughts were likely triggered by anomalous tropical sea surface temperatures (SSTs), with La Niña‐like SST anomalies leading to drought in North America, and El‐Niño‐like SSTs causing drought in East China. Over Africa, the southward shift of the warmest SSTs in the Atlantic and warming in the Indian Ocean are responsible for the recent Sahel droughts. Local feedbacks may enhance and prolong drought. Global aridity has increased substantially since the 1970s due to recent drying over Africa, southern Europe, East and South Asia, and eastern Australia. Although El Niño‐Southern Oscillation (ENSO), tropical Atlantic SSTs, and Asian monsoons have played a large role in the recent drying, recent warming has increased atmospheric moisture demand and likely altered atmospheric circulation patterns, both contributing to the drying. Climate models project increased aridity in the 21 st century over most of Africa, southern Europe and the Middle East, most of the Americas, Australia, and Southeast Asia. Regions like the United States have avoided prolonged droughts during the last 50 years due to natural climate variations, but might see persistent droughts in the next 20–50 years. Future efforts to predict drought will depend on models' ability to predict tropical SSTs. WIREs Clim Change 2011 2 45–65 DOI: 10.1002/wcc.81 This article is categorized under: Paleoclimates and Current Trends > Detection and Attribution Paleoclimates and Current Trends > Modern Climate Change Assessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change Assessing Impacts of Climate Change > Observed Impacts of Climate Change
Agriculture• 2010• Wiley
Periodicals
More than 75 percent decline over 27 years in total flying insect biomass in protected areas
Global declines in insects have sparked wide interest among scientists, politicians, and the general public. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxonomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape.
Agriculture• 2017• Public Library of Science
Periodicals
GISAID: Global initiative on sharing all influenza data – from vision to reality
No description supplied
Agriculture• 2017• European Centre for Disease Prevention and Control
Periodicals
Corporate social responsibility and access to finance
We investigate whether superior performance on corporate social responsibility ( CSR ) strategies leads to better access to finance. We hypothesize that better access to finance can be attributed to (1) reduced agency costs due to enhanced stakeholder engagement and (2) reduced informational asymmetry due to increased transparency. Using a large cross‐section of firms, we find that firms with better CSR performance face significantly lower capital constraints. We provide evidence that both better stakeholder engagement and transparency around CSR performance are important in reducing capital constraints. The results are further confirmed using several alternative measures of capital constraints, a paired analysis based on a ratings shock to CSR performance, an instrumental variables approach, and a simultaneous equations approach. Finally, we show that the relation is driven by both the social and environmental dimension of CSR . Copyright © 2013 John Wiley & Sons, Ltd.
Agriculture• 2013• Wiley
Periodicals
Organic aerosol and global climate modelling: a review
Abstract. The present paper reviews existing knowledge with regard to Organic Aerosol (OA) of importance for global climate modelling and defines critical gaps needed to reduce the involved uncertainties. All pieces required for the representation of OA in a global climate model are sketched out with special attention to Secondary Organic Aerosol (SOA): The emission estimates of primary carbonaceous particles and SOA precursor gases are summarized. The up-to-date understanding of the chemical formation and transformation of condensable organic material is outlined. Knowledge on the hygroscopicity of OA and measurements of optical properties of the organic aerosol constituents are summarized. The mechanisms of interactions of OA with clouds and dry and wet removal processes parameterisations in global models are outlined. This information is synthesized to provide a continuous analysis of the flow from the emitted material to the atmosphere up to the point of the climate impact of the produced organic aerosol. The sources of uncertainties at each step of this process are highlighted as areas that require further studies.
Agriculture• 2005• Copernicus Publications
Periodicals
Short Chain Fatty Acids (SCFAs)-Mediated Gut Epithelial and Immune Regulation and Its Relevance for Inflammatory Bowel Diseases
Ulcerative colitis (UC) and Crohn's disease (CD), collectively known as Inflammatory Bowel Diseases (IBD), are caused by a complex interplay between genetic, immunologic, microbial and environmental factors. Dysbiosis of the gut microbiome is increasingly considered to be causatively related to IBD and is strongly affected by components of a Western life style. Bacteria that ferment fibers and produce short chain fatty acids (SCFAs) are typically reduced in mucosa and feces of patients with IBD, as compared to healthy individuals. SCFAs, such as acetate, propionate and butyrate, are important metabolites in maintaining intestinal homeostasis. Several studies have indeed shown that fecal SCFAs levels are reduced in active IBD. SCFAs are an important fuel for intestinal epithelial cells and are known to strengthen the gut barrier function. Recent findings, however, show that SCFAs, and in particular butyrate, also have important immunomodulatory functions. Absorption of SCFAs is facilitated by substrate transporters like MCT1 and SMCT1 to promote cellular metabolism. Moreover, SCFAs may signal through cell surface G-protein coupled receptors (GPCRs), like GPR41, GPR43, and GPR109A, to activate signaling cascades that control immune functions. Transgenic mouse models support the key role of these GPCRs in controlling intestinal inflammation. Here, we present an overview of microbial SCFAs production and their effects on the intestinal mucosa with specific emphasis on their relevance for IBD. Moreover, we discuss the therapeutic potential of SCFAs for IBD, either applied directly or by stimulating SCFAs-producing bacteria through pre- or probiotic approaches.
Agriculture• 2019• Frontiers Media
Periodicals
Estimation of the molecular weights of proteins by Sephadex gel-filtration
When a mixture of molecules is passed through a column of porous gel granules, the molecules may appear in the effluent in order of decreasing size. Fractionation is believed to occur when diffusion of the molecules into the gel pores is restricted but not prevented because of their size, and because they pass through the column at rates that are related inversely to the fluid volume accessible to them within the column. Lathe & Ruthven (1956) suggested that the dimensions of protein and poly- saccharide molecules might be estimated by this technique, now widely known as gel-filtration. However, evaluation of their suggestion is difficult because of uncertainty about the size and shape of macromolecules in solution (Schachman, 1960). Although molecular weight is unlikely to be a good approximation for size in comparing such dis- similar molecules as proteins and polysaccharides, the correlation between molecular weights and gelfiltration behaviour of dextrans (Granath & Flodin, 1961) indicates that, for a homogeneous series of macromolecules, size and molecular weight are closely related. Andrews (1962) obtained evidence from experiments with agar-gel columns that this was also true for a number of proteins, and showed that gel-filtration can be used as a comparative method to give useful estimates of the molecular weights of proteins.
Agriculture• 1964• Portland Press
Periodicals
The growing use of herbal medicines: issues relating to adverse reactions and challenges in monitoring safety
The use of herbal medicinal products and supplements has increased tremendously over the past three decades with not less than 80% of people worldwide relying on them for some part of primary healthcare. Although therapies involving these agents have shown promising potential with the efficacy of a good number of herbal products clearly established, many of them remain untested and their use are either poorly monitored or not even monitored at all. The consequence of this is an inadequate knowledge of their mode of action, potential adverse reactions, contraindications, and interactions with existing orthodox pharmaceuticals and functional foods to promote both safe and rational use of these agents. Since safety continues to be a major issue with the use of herbal remedies, it becomes imperative, therefore, that relevant regulatory authorities put in place appropriate measures to protect public health by ensuring that all herbal medicines are safe and of suitable quality. This review discusses toxicity-related issues and major safety concerns arising from the use of herbal medicinal products and also highlights some important challenges associated with effective monitoring of their safety.
Agriculture• 2014• Frontiers Media
Periodicals
The map-based sequence of the rice genome
[no abstract]
Agriculture• 2005• Nature Portfolio
Periodicals
Going back to the roots: the microbial ecology of the rhizosphere
[no abstract]
Agriculture• 2013• Nature Portfolio
Periodicals
Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches
Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.
Agriculture• 2024• Taylor & Francis
Periodicals
River plastic emissions to the world’s oceans
Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies.
Agriculture• 2017• Nature Portfolio
Periodicals
Belowground biodiversity and ecosystem functioning
[no abstract]
Agriculture• 2014• Nature Portfolio
Periodicals
The grapevine genome sequence suggests ancestral hexaploidization in major angiosperm phyla
The fourth genome sequence of a flowering plant, the second of a woody plant species and the first for a fruit crop. These important boxes are ticked by the genome sequence published in this issue. The new sequence is particularly revealing about the role of gene duplication in the evolution of the flowering plants. But the reason why non-geneticists will turn to it is more to do with its commercial application: the crop is the grapevine (Vitis vinifera) and the variety is Pinot Noir. A French and Italian consortium has produced sequence and analysis of Vitis vinifera PN40024, a grapevine originally derived from Pinot Noir. As you might expect, the grapevine has twice as many terpene synthases as other sequenced plants; these enzymes contribute to resins, essential oils and aromas. The analysis of the first plant genomes provided unexpected evidence for genome duplication events in species that had previously been considered as true diploids on the basis of their genetics1,2,3. These polyploidization events may have had important consequences in plant evolution, in particular for species radiation and adaptation and for the modulation of functional capacities4,5,6,7,8,9,10. Here we report a high-quality draft of the genome sequence of grapevine (Vitis vinifera) obtained from a highly homozygous genotype. The draft sequence of the grapevine genome is the fourth one produced so far for flowering plants, the second for a woody species and the first for a fruit crop (cultivated for both fruit and beverage). Grapevine was selected because of its important place in the cultural heritage of humanity beginning during the Neolithic period11. Several large expansions of gene families with roles in aromatic features are observed. The grapevine genome has not undergone recent genome duplication, thus enabling the discovery of ancestral traits and features of the genetic organization of flowering plants. This analysis reveals the contribution of three ancestral genomes to the grapevine haploid content. This ancestral arrangement is common to many dicotyledonous plants but is absent from the genome of rice, which is a monocotyledon. Furthermore, we explain the chronology of previously described whole-genome duplication events in the evolution of flowering plants.
Agriculture• 2007• Nature Portfolio
Periodicals
Impacts of climate change on the future of biodiversity
Many studies in recent years have investigated the effects of climate change on the future of biodiversity. In this review, we first examine the different possible effects of climate change that can operate at individual, population, species, community, ecosystem and biome scales, notably showing that species can respond to climate change challenges by shifting their climatic niche along three non-exclusive axes: time (e.g. phenology), space (e.g. range) and self (e.g. physiology). Then, we present the principal specificities and caveats of the most common approaches used to estimate future biodiversity at global and sub-continental scales and we synthesise their results. Finally, we highlight several challenges for future research both in theoretical and applied realms. Overall, our review shows that current estimates are very variable, depending on the method, taxonomic group, biodiversity loss metrics, spatial scales and time periods considered. Yet, the majority of models indicate alarming consequences for biodiversity, with the worst-case scenarios leading to extinction rates that would qualify as the sixth mass extinction in the history of the earth.
Agriculture• 2012• Wiley