2,438 research outputs found
When All the World\u27s a Stage: The Impact of Events on News Coverage of South Africa, 1979-1985
A time series analysis was used to investigate: (1) whether a significant increase in news coverage of South Africa occurred during the critical years of 1979-1985 ; (2) whether the geographic origin and/or sociopolitical impact of events, rather than deaths per se, caused the increase; and (3) the manner in which the increase occurred. Results indicated that two symbolic events (i.e., a series of riots in twenty-one South African townships, internal to South Africa; and the awarding of the Nobel Prize to Bishop Desmond Tutu, external to South Africa) cumulatively were responsible for a significant rise in news coverage of South Africa. The relationship of these symbolic sociopolitical events to the forces that shape short-term news headlines and long-term social change in general, including the imminent demise of apartheid in particular is discussed
Doctor of Philosophy
dissertationBryostatin 1 is a large macrocyclic polyketide natural product that was isolated from the marine bryozoan Bugula neritina. Bryostatin was found to have many interesting biological properties stemming from its extremely high affinity for protein kinase C (PKC) isozymes. Bryostatin 1 has attracted increased attention due to its anticancer and immune system stimulating properties. In recent years, bryostatin 1 has been found to have properties that may lead to effective treatments for Alzheimer’s disease and HIV. Several high affinity PKC ligands are potent tumor promoters; however, bryostatin 1 does not display any of these properties and even antagonizes the effects of phorbol esters, which are potent tumor promoters. Due to the continued interest in bryostatin 1, attention has been focused on the synthesis of simplified analogs in order to study structure-function relationships. Most of this work has focused on the synthesis of analogs with simplified AB top-halfs, while very little attention has been applied towards the synthesis of analogs with simplified C-ring binding domains. Extensive work has been conducted on the synthesis of diacylglycerol (DAG) lactone analogs, which are simple high affinity PKC ligands. The focus of this work involves the substitution of a DAG lactone for the C-ring in a bryostatin analog, resulting in the synthesis of 3 bryostatin analogs. Biological evaluation indicates that significant binding affinity in the first analog was lost as compared to the natural product even though all structural elements were present that are thought to be required for good affinity. Molecular modeling studies indicate that the planer conformation of the top-half of the natural product was lost in these new analogs, resulting in a conformation unfavorable for effective binding. The binding domain orientation of the analog was reversed, resulting in a slight increase in affinity, but at the cost of lower stability under biological conditions, due to the diester linkage used to assemble the first two analogs. Building upon these results, a third-generation analog with increased lipophilicity and lacking the diester linker was synthesized. The third-generation analog had a much higher affinity for PKC as well as an improved biological profile as compared to the first 2 analogs
Polymodal TRPV1 and TRPV4 sensors colocalize but do not functionally interact in a subpopulation of mouse retinal ganglion cells
Human Health Countermeasures (HHC) Element Management Plan: Human Research Program
NASA s Human Research Program (HRP) is an applied research and technology program within the Human Exploration and Operations Mission Directorate (HEOMD) that addresses human health and performance risk mitigation strategies in support of exploration missions. The HRP research and technology development is focused on the highest priority risks to crew health and safety with the goal of ensuring mission success and maintaining long-term crew health. Crew health and performance standards, defined by the NASA Chief Health and Medical Officer (CHMO), set the acceptable risk level for exploration missions. The HRP conducts research to inform these standards as well as provide deliverables, such as countermeasures, that ensure standards can be met to maximize human performance and mission success. The Human Health Countermeasures (HHC) Element was formed as part of the HRP to develop a scientifically-based, integrated approach to understanding and mitigating the health risks associated with human spaceflight. These health risks have been organized into four research portfolios that group similar or related risks. A fifth portfolio exists for managing technology developments and infrastructure projects. The HHC Element portfolios consist of: a) Vision and Cardiovascular; b) Exercise and Performance; c) Multisystem; d) Bone; and e) Technology and Infrastructure. The HHC identifies gaps associated with the health risks and plans human physiology research that will result in knowledge required to more fully understand risks and will result in validated countermeasures to mitigate risks
Transitory Effects of Dimethyl Sulfoxide on the Electrical Properties of Isolated Frog Skin
The experiments indicate that when DMSO-Ringer\u27s solutions are applied to the outside of the frog skin, the electrical potential difference across the skin decreases while the short circuiting current increases slightly. Ringer\u27s solutions containing DMSO applied to the inside of the skin caused both the short circuiting current and the potential difference across the skin to decrease. These observations appear to be directly related to the concentration of DMSO-Ringer\u27s applied. The observed effects are discussed with respect to possible changes in the skin brought about by the DMSO and the relationships of these phenomena to active transport functions of the skin
Monopoly Power with a Short Selling Constraint
We show if a speculator can benefit from reducing a monopoly’s rents through short selling, then a speculator may take a short position in a monopoly, overcome the barriers to entry, and compete with the monopoly. The competition drives down the monopoly’s rents, and as a result, the short position becomes profitable and covers the cost of entry. If entry is impossible, then the speculator may coordinate and pay the firm’s counter-parties to stop trading with the monopoly rather than entering. Either way, increasing a speculator’s ability to short a firm’s rents results in a constraint on the monopoly and forces it to act more like a price taker. The mechanism is a market based approach to antitrust
The InproTK 2012 release
Baumann T, Schlangen D. The InproTK 2012 release. In: Eskenazi M, Black A, Traum D, eds. SDCTD '12 NAACL-HLT Workshop on Future Directions and Needs in the Spoken Dialog Community: Tools and Data. Stroudsburg, PA: ACL; 2012: 29-32
Exploration Medical Capability (ExMC) Projects
During missions to the Moon or Mars, the crew will need medical capabilities to diagnose and treat disease as well as for maintaining their health. The Exploration Medical Capability Element develops medical technologies, medical informatics, and clinical capabilities for different levels of care during space missions. The work done by team members in this Element is leading edge technology, procedure, and pharmacological development. They develop data systems that protect patient's private medical information, aid in the diagnosis of medical conditions, and act as a repository of relevant NASA life sciences experimental studies. To minimize the medical risks to crew health the physicians and scientists in this Element develop models to quantify the probability of medical events occurring during a mission. They define procedures to treat an ill or injured crew member who does not have access to an emergency room and who must be cared for in a microgravity environment where both liquids and solids behave differently than on Earth. To support the development of these medical capabilities, the Element manages the development of medical technologies that prevent, monitor, diagnose, and treat an ill or injured crewmember. The Exploration Medical Capability Element collaborates with the National Space Biomedical Research Institute (NSBRI), the Department of Defense, other Government-funded agencies, academic institutions, and industry
Exploration Medical Capability
Exploration Medical Capability (ExMC) is an element of NASA's Human Research Program (HRP). ExMC's goal is to address the risk of the Inability to Adequately Recognize or Treat an Ill or Injured Crewmember. This poster highlights the approach ExMC has taken to address this goal and our current areas of interest. The Space Medicine Exploration Medical Condition List (SMEMCL) was created to identify medical conditions of concern during exploration missions. The list was derived from space flight medical incidents, the shuttle medical checklist, the International Space Station medical checklist, and expert opinion. The conditions on the list were prioritized according to mission type by a panel comprised of flight surgeons, physician astronauts, engineers, and scientists. From the prioritized list, the ExMC element determined the capabilities needed to address the medical conditions of concern. Where such capabilities were not currently available, a gap was identified. The element s research plan outlines these gaps and the tasks identified to achieve the desired capabilities for exploration missions. This poster is being presented to inform the audience of the gaps and tasks being investigated by ExMC and to encourage discussions of shared interests and possible future collaborations
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