Research Triangle Park

About: Research Triangle Park is a nonprofit organization based out in Durham, North Carolina, United States. It is known for research contribution in the topics: Population & Receptor. The organization has 24961 authors who have published 35800 publications receiving 1684504 citations. The organization is also known as: RTP.

Endocrine profiling and prioritization of environmental chemicals using ToxCast data.

Abstract: BackgroundThe prioritization of chemicals for toxicity testing is a primary goal of the U.S. Environmental Protection Agency (EPA) ToxCast™ program. Phase I of ToxCast used a battery of 467 in vitr...

Seasonal variations in air pollution particle-induced inflammatory mediator release and oxidative stress.

Abstract: Health effects associated with particulate matter (PM) show seasonal variations. We hypothesized that these heterogeneous effects may be attributed partly to the differences in the elemental composition of PM. Normal human bronchial epithelial (NHBE) cells and alveolar macrophages (AMs) were exposed to equal mass of coarse [PM with aerodynamic diameter of 2.5–10 μm (PM2.5–10)], fine (PM2.5), and ultrafine (PM < 0.1) ambient PM from Chapel Hill, North Carolina, during October 2001 (fall) and January (winter), April (spring), and July (summer) 2002. Production of interleukin (IL)-8, IL-6, and reactive oxygen species (ROS) was measured. Coarse PM was more potent in inducing cytokines, but not ROSs, than was fine or ultrafine PM. In AMs, the October coarse PM was the most potent stimulator for IL-6 release, whereas the July PM consistently stimulated the highest ROS production measured by dichlorofluorescein acetate and dihydrorhodamine 123 (DHR). In NHBE cells, the January and the October PM were consistently the strongest stimulators for IL-8 and ROS, respectively. The July PM increased only ROS measured by DHR. PM had minimal effects on chemiluminescence. Principal-component analysis on elemental constituents of PM of all size fractions identified two factors, Cr/Al/Si/Ti/Fe/Cu and Zn/As/V/Ni/Pb/Se, with only the first factor correlating with IL-6/IL-8 release. Among the elements in the first factor, Fe and Si correlated with IL-6 release, whereas Cr correlated with IL-8 release. These positive correlations were confirmed in additional experiments with PM from all 12 months. These results indicate that elemental constituents of PM may in part account for the seasonal variations in PM-induced adverse health effects related to lung inflammation.

Scaling the bandwidth wall: challenges in and avenues for CMP scaling

Abstract: As transistor density continues to grow at an exponential rate in accordance to Moore's law, the goal for many Chip Multi-Processor (CMP) systems is to scale the number of on-chip cores proportionally. Unfortunately, off-chip memory bandwidth capacity is projected to grow slowly compared to the desired growth in the number of cores. This creates a situation in which each core will have a decreasing amount of off-chip bandwidth that it can use to load its data from off-chip memory. The situation in which off-chip bandwidth is becoming a performance and throughput bottleneck is referred to as the bandwidth wall problem.In this study, we seek to answer two questions: (1) to what extent does the bandwidth wall problem restrict future multicore scaling, and (2) to what extent are various bandwidth conservation techniques able to mitigate this problem. To address them, we develop a simple but powerful analytical model to predict the number of on-chip cores that a CMP can support given a limited growth in memory traffic capacity. We find that the bandwidth wall can severely limit core scaling. When starting with a balanced 8-core CMP, in four technology generations the number of cores can only scale to 24, as opposed to 128 cores under proportional scaling, without increasing the memory traffic requirement. We find that various individual bandwidth conservation techniques we evaluate have a wide ranging impact on core scaling, and when combined together, these techniques have the potential to enable super-proportional core scaling for up to 4 technology generations.

Solid-fuel household cook stoves: characterization of performance and emissions.

Abstract: In this study, 14 solid-fuel household cook stove and fuel combinations, including 10 stoves and four fuels, were tested for performance and pollutant emissions using a WBT (Water Boiling Test) protocol. Results from the testing showed that some stoves currently used in the field have improved fuel efficiency and lower pollutant emissions compared with traditional cooking methods. Stoves with smaller-mass components exposed to the heat of fuel combustion tended to take lesser time to boil, have better fuel efficiency, and lower pollutant emissions. The challenge is to design stoves with smaller-mass components that also have acceptable durability, affordable cost, and meet user needs. Results from this study provide stove performance and emissions information to practitioners disseminating stove technology in the field. This information may be useful for improving the design of existing stoves and for developing new stove designs. Comparison of results between laboratories shows that results can be replicated between labs when the same stove and fuel are tested using the WBT protocol. Recommendations were provided to improve the ability to replicate results between labs. Implications of better solid-fuel cook stoves are improved human health, reduced fuel use, reduced deforestation, and reduced global climate change.