Effects of the Presence of Democracy in Hegemons on Hegemonic Intervention in a Unipolar System

This paper outlines major theoretical elements of the effects of democracy and hegemony on intervention and peace. In particular, it examines the effect of the presence of democracy in hegemonic military and coercive intervention, and non-intervention. The presence of democracy in an intervening hegemon can have a significant and pronounced effect on policy-choices and success in advancing peaceful-resolution mechanisms and norms for dispute-resolution

Soil bacterial influence on alfalfa growth and health

2013 Spring.Includes bibliographical references.Soil microbial communities have demonstrated enormous potential for promotion of plant health and productivity. In particular, the diversity of the soil community may play an important role for increased plant growth. However, previous research has focused on soil fungal diversity and neglected the role that diversity of soil bacteria may play in influencing plant growth. Therefore, a greenhouse study was conducted to determine if soil bacterial community structure influences alfalfa productivity. Prior to setup, nine soils with varying physico-chemical and microbiological profiles were chemically and biologically characterized. Soil physico-chemical factors for experimental soils were quantified via standard methods of soil nutrient testing. In addition, soil microbiology was characterized using 454 pyrosequencing to determine soil diversity indices and taxonomic classification of the soil bacterial community. These microbial communities were extracted into soil suspensions and transplanted to alfalfa plants growing in a sterile substrate. Filtered (soil microorganisms removed) and non-filtered (soil microorganisms retained) soil suspensions were applied to separate soil chemical and microbiological effects. Alfalfa plants were grown in a greenhouse for 60 days post germination; then roots and shoots were harvested, dried and weighed. This experimental setup was used to answer two distinct research questions. In the first study, alfalfa biomass was correlated with both soil physico-chemical and bacterial measures to determine which soil factors influenced plant productivity. For four soils, a biologically inactive (filtered) extract included unidentified chemical factors that had a negative effect on plant biomass production. However, in two of these cases inclusion of soil microbes counteracted this negative effect and restored plant growth to a level equal to the non-amended control. Among bacterial classes, the relative abundance of Deltaproteobacteria in soils was significantly correlated with plant productivity. Correlations between plant productivity and soil bacterial richness, diversity and evenness were marginally significant and more highly correlated than soil physico-chemical factors. Results suggest that soil microbiology can compensate for negative effects on plant growth due to soil chemistry, potentially due to microbial remediation of organic soil chemical residues such as herbicides. Also, in this study, relative abundance of specific bacterial taxa was more highly correlated than bacterial diversity indices with improved plant productivity. Many species of bacteria, referred to collectively as plant growth promoting rhizobacteria (PGPR), are known to be particularly beneficial to plant health and yield. However, inconsistency in establishment of PGPR inoculants has limited their practical use in the field. While PGPR inoculation failures have been partially attributed to competition with the indigenous soil community, studies focusing on the role that indigenous soil bacteria play on the establishment of PGPR inoculants are rare. Soil bacterial diversity is known to prevent establishment of fungal pathogens and may inhibit PGPR establishment as well. Therefore a second study was conducted using four of the nine original experimental soils, which were selected to represent the largest variety of US locale and management types from collected soils. Including four soils allowed for expansion beyond previous bacterial diversity research, which utilized only one soil type, while simultaneously including inoculation treatments of two different organisms. The same experimental setup was utilized except that either a PGPR (Pseudomonas putida) or a pathogenic microorganism (Phytophthora medicaginis) was introduced for comparison to non-amended controls. Subsequently, effects on alfalfa biomass production and disease were measured. In addition, PGPR colonization by P. putida KT2440 was quantified using qPCR via detection of the gfp gene carried on the KT2440 plasmid. Results from the second study showed increases in alfalfa productivity with added PGPR were significantly larger in soils with higher soil microbial diversity. However, no differences in PGPR root colonization were observed among non-filtered treatment groups. These results suggest that the increased effectiveness of the PGPR in high diversity communities was due to increased effectiveness of other beneficial soil microorganisms. Indeed, several native PGPR and N cycling species were correlated with shoot biomass increases when adding PGPR. Conversely, disease incidence and severity caused by "P. medicaginis" was not significantly associated with soil bacterial diversity. These results emphasize the role of soil microbial community composition and its functional relationship with the invading organism in predicting effects of an introduced PGPR inoculant or soil pathogen. In conclusion, both soil chemical and biological qualities were evaluated to lend confidence that observed effects on alfalfa biomass and microbial invasion were due to biological rather than chemical influences. Soil bacteria were found to influence plant productivity by counteracting other soil factors with negative effects on plant growth. In addition, soil community diversity played a less consequential role in these experiments than the specific taxonomical and functional bacterial members. Furthermore, soil bacterial diversity significantly improved the beneficial effects of PGPR inoculants, but was not shown to significantly reduce disease incidence or severity

United States benefits of improved worldwide wheat crop information from a LANDSAT system

The value of worldwide information improvements on wheat crops, promised by LANDSAT, is measured in the context of world wheat markets. These benefits are based on current LANDSAT technical goals and assume that information is made available to all (United States and other countries) at the same time. A detailed empirical sample demonstration of the effect of improved information is given; the history of wheat commodity prices for 1971-72 is reconstructed and the price changes from improved vs. historical information are compared. The improved crop forecasting from a LANDSAT system assumed include wheat crop estimates of 90 percent accuracy for each major wheat producing region. Accurate, objective worldwide wheat crop information using space systems may have a very stabilizing influence on world commodity markets, in part making possible the establishment of long-term, stable trade relationships

Presentation of Severe Acute Respiratory Syndrome-Coronavirus 2 Infection as Cholestatic Jaundice in Two Healthy Adolescents

© 2020 Elsevier Inc. Liver abnormalities in severe acute respiratory syndrome-coronavirus 2 infection, including hepatitis and cholestasis, have been observed in adults and are associated with worse outcomes. We describe 2 adolescents with cholestasis and hepatitis with mild presentation of severe acute respiratory syndrome-coronavirus 2 lacking typical symptoms. Our intention is to raise index of suspicion for testing and protective equipment use

Shifts in microbial communities in soil, rhizosphere and roots of two major crop systems under elevated CO2 and O3

Rising atmospheric concentrations of CO2 and O3 are key features of global environmental change. To investigate changes in the belowground bacterial community composition in response to elevated CO2 and O3 (eCO2 and eO3) the endosphere, rhizosphere and soil were sampled from soybeans under eCO2 and maize under eO3. The maize rhizosphere and endosphere α-diversity was higher than soybean, which may be due to a high relative abundance of Rhizobiales. Only the rhizosphere microbiome composition of the soybeans changed in response to eCO2, associated with an increased abundance of nitrogen fixing microbes. In maize, the microbiome composition was altered by the genotype and linked to differences in root exudate profiles. The eO3 treatment did not change the microbial communities in the rhizosphere, but altered the soil communities where hybrid maize was grown. In contrast to previous studies that focused exclusively on the soil, this study provides new insights into the effects of plant root exudates on the composition of the belowground microbiome in response to changing atmospheric conditions. Our results demonstrate that plant species and plant genotype were key factors driving the changes in the belowground bacterial community composition in agroecosystems that experience rising levels of atmospheric CO2 and O3

Variables and Strategies in Development of Therapeutic Post-Transcriptional Gene Silencing Agents

Post-transcriptional gene silencing (PTGS) agents such as ribozymes, RNAi and antisense have substantial potential for gene therapy of human retinal degenerations. These technologies are used to knockdown a specific target RNA and its cognate protein. The disease target mRNA may be a mutant mRNA causing an autosomal dominant retinal degeneration or a normal mRNA that is overexpressed in certain diseases. All PTGS technologies depend upon the initial critical annealing event of the PTGS ligand to the target RNA. This event requires that the PTGS agent is in a conformational state able to support hybridization and that the target have a large and accessible single-stranded platform to allow rapid annealing, although such platforms are rare. We address the biocomplexity that currently limits PTGS therapeutic development with particular emphasis on biophysical variables that influence cellular performance. We address the different strategies that can be used for development of PTGS agents intended for therapeutic translation. These issues apply generally to the development of PTGS agents for retinal, ocular, or systemic diseases. This review should assist the interested reader to rapidly appreciate critical variables in PTGS development and facilitate initial design and testing of such agents against new targets of clinical interest