33 research outputs found
Contributing Factors to the Existence of Right-to-Work Laws in Two Southern States
Providing explanations of why governments or political systems adopt the public policies they do is and has been a goal of political science for some time. The purpose of this paper is to investigate one specific policy out-come -- so called right-to- work laws -- in the context of the political environment provided by two Southern states: Arkansas and Louisiana.1 Specifically, an effort will be made to determine what environmental factors have tended to encourage the adoption of right-to-work laws and how the proponents and opponents of such laws have attempted to influence their passage or repeal
The upper airway response to pollen is enhanced by exposure to combustion particulates: a pilot human experimental challenge study.
Although human experimental studies have shown that gaseous pollutants enhance the inflammatory response to allergens, human data on whether combustion particulates enhance the inflammatory response to allergen are limited. Therefore, we conducted a human experimental study to investigate whether combustion particulates enhance the inflammatory response to aeroallergens. "Enhancement" refers to a greater-than-additive response when combustion particulates are delivered with allergen, compared with the responses when particulates and allergen are delivered alone. Eight subjects, five atopic and three nonatopic, participated in three randomized exposure-challenge sessions at least 2 weeks apart (i.e., clean air followed by allergen, particles followed by no allergen, or particles followed by allergen). Each session consisted of nasal exposure to combustion particles (target concentration of 1.0 mg/m3) or clean air for 1 hr, followed 3 hr later by challenge with whole pollen grains or placebo. Nasal lavage was performed immediately before particle or clean air exposure, immediately after exposure, and 4, 18 and 42 hr after pollen challenge. Cell counts, differentials, and measurement of cytokines were performed on each nasal lavage. In atopic but not in nonatopic subjects, when allergen was preceded by particulates, there was a significant enhancement immediately after pollen challenge in nasal lavage leukocytes and neutrophils (29.7 X 10(3) cells/mL and 25.4 X 10(3) cells/mL, respectively). This represents a 143% and 130% enhancement, respectively. The enhanced response for interleukin-4 was 3.23 pg/mL (p = 0.06), a 395% enhancement. In atopic subjects there was evidence of an enhanced response when particulates, as compared to clean air, preceded the allergen challenge
Recommended from our members
The Upper Airway Response to Pollen is Enhanced by Exposure to Combustion Particulates: A Pilot Human Experimental Challenge Study.
Although human experimental studies have shown that gaseous pollutants enhance the inflammatory response to allergens, human data on whether combustion particulates enhance the inflammatory response to allergen are limited. Therefore, we conducted a human experimental study to investigate whether combustion particulates enhance the inflammatory response to aeroallergens. "Enhancement" refers to a greater-than-additive response when combustion particulates are delivered with allergen, compared with the responses when particulates and allergen are delivered alone. Eight subjects, five atopic and three nonatopic, participated in three randomized exposure-challenge sessions at least 2 weeks apart (i.e., clean air followed by allergen, particles followed by no allergen, or particles followed by allergen). Each session consisted of nasal exposure to combustion particles (target concentration of 1.0 mg/m) or clean air for 1 hr, followed 3 hr later by challenge with whole pollen grains or placebo. Nasal lavage was performed immediately before particle or clean air exposure, immediately after exposure, and 4, 18 and 42 hr after pollen challenge. Cell counts, differentials, and measurement of cytokines were performed on each nasal lavage. In atopic but not in nonatopic subjects, when allergen was preceded by particulates, there was a significant enhancement immediately after pollen challenge in nasal lavage leukocytes and neutrophils (29.7 X 10 cells/mL and 25.4 X 10 cells/mL, respectively). This represents a 143% and 130% enhancement, respectively. The enhanced response for interleukin-4 was 3.23 pg/mL (p = 0.06), a 395% enhancement. In atopic subjects there was evidence of an enhanced response when particulates, as compared to clean air, preceded the allergen challenge
The role of phosphodiesterase 12 (PDE12) as a negative regulator of the innate immune response and the discovery of antiviral inhibitors
2',5'-Oligoadenylate synthetase (OAS) enzymes and RNase-L constitute a major effector arm of interferon (IFN)-mediated antiviral defense. OAS produces a unique oligonucleotide second messenger, 2',5'-oligoadenylate (2-5A), that binds and activates RNase-L. This pathway is down-regulated by virus- and host-encoded enzymes that degrade 2-5A. Phosphodiesterase 12 (PDE12) was the first cellular 2-5A- degrading enzyme to be purified and described at a molecular level. Inhibition of PDE12 may up-regulate the OAS/RNase-L pathway in response to viral infection resulting in increased resistance to a variety of viral pathogens. We generated a PDE12-null cell line, HeLaΔPDE12, using transcription activator-like effector nuclease-mediated gene inactivation. This cell line has increased 2-5A levels in response to IFN and poly(I-C), a double-stranded RNA mimic compared with the parental cell line. Moreover, HeLaΔPDE12 cells were resistant to viral pathogens, including encephalomyocarditis virus, human rhinovirus, and respiratory syncytial virus. Based on these results, we used DNA-encoded chemical library screening to identify starting points for inhibitor lead optimization. Compounds derived from this effort raise 2-5A levels and exhibit antiviral activity comparable with the effects observed with PDE12 gene inactivation. The crystal structure of PDE12 complexed with an inhibitor was solved providing insights into the structure-activity relationships of inhibitor potency and selectivity
POLITICAL STRUCTURE AND POLITICAL REPRESENTATION ON URBAN CITY COUNCILS
Most of the previous studies examining the consequences of different political structures among U.S. cities have analyzed some indicator of aggregate policy results. Using a nationwide sample of almost 1,000 city council members in cities over 50,000 population, this dissertation looks at the consequences of structure at the individual level in terms of who is elected to office, and their behaviors and attitudes. District versus at-large and partisan versus nonpartisan local election structures are compared across several dimensions of political representation as they affect the individual office holder. Council members are evaluated in terms of descriptive representation, service representation, representational focus, policy representation, and allocative representation. After controlling for environmental differences among the cities, election structure was found to have a bearing upon each of the dimensions of representation except for policy representation. Structure seemed to be of greatest consequence on what might be termed styles of behavior, especially the tendency for the representative to act as an ombudsman for constituents and to adopt one constituency focus or another. Otherwise, either or both structural dimensions had a relatively modest impact on the socio-economic characteristics of those elected, their partisan identity (under some conditions), and the amount of conflict on the council. Particularly noteworthy were differences in the role of a Democrat v. Republican cleavage in legally partisan as opposed to legally nonpartisan cities. Such a cleavage was the most often cited as the principal source of factionalism on the council by partisan elected representatives but the least likely cited source of factionalism among nonpartisan council members. Since no differences are found in the level of conflict between the two groups, a strong argument could be made that partisan systems are conducive to the establishment of a more coherent and accountable policy process
Ecological Niche Modeling and Sustainable Agroforestry: Climate Change Mitigation for Guatemalan Coffee
Coffea arabica is a species with far-reaching impacts on the global economy. Nevertheless, climate-related challenges threaten the coffee industry at its source: its growing regions. The coffee industry is a significant economic driver in Guatemala, but farmers are increasingly reporting losses in crop yield and arable land due to climate-related challenges. Ecological niche modeling (ENM) can be employed to make predictions about the current and future suitability of regions for a species by identifying significant biotic or abiotic indicators. An ENM was used to project suitable land into the future using climate change projection models known as representative concentration pathways (RCPs), for the coffee plant and a number of other species. Due to the potential of shade trees to lessen heat stress on coffee plants, common shade trees for the region were modeled. Additionally, a fungus species responsible for detrimental coffee leaf rust was modeled. Results of these models indicated potential for substantial climate-related habitat losses for the coffee plant in the coming decades. Examination of model predictions allow for greater understanding of the climate-related variables affecting the ecology of the coffee plant, and the potential risks to the industry, in a changing climate. Additionally, ENM models for coffee rust and shade trees can help Guatemalan farmers make informed decisions about farm management