Clemson University

About: Clemson University is a education organization based out in Clemson, South Carolina, United States. It is known for research contribution in the topics: Population & Control theory. The organization has 20556 authors who have published 42518 publications receiving 1170779 citations. The organization is also known as: Clemson Agricultural College of South Carolina.

Utilization of waste fibers in stone matrix asphalt mixtures

Abstract: Waste fibers produced from manufacturing processes such as scrap tire processing and automotive carpet manufacturing are sometimes used in other applications, but commonly are disposed of in landfills. If these fibers could be beneficially utilized in any application, it would reduce the load on the nation’s landfills. Also, since these are waste materials, the cost of using these fibers compared to fibers manufactured for a specific application could be considerably less. The major objective of this research was to determine the feasibility of utilizing waste tire and carpet fibers in stone matrix asphalt (SMA). Many states utilize such rut resistant SMA mixtures on heavily traveled highways. Fibers are included in SMA mixtures as a stabilizing additive to prevent excessive draindown caused by relatively high contents of polymer modified asphalt binder. The common types of fiber used in SMA include cellulose and mineral fibers. This study compared the performance of SMA mixtures containing waste tire and carpet fibers with mixes made with commonly used cellulose and other polyester fibers produced specifically for use in hot mix asphalt (HMA). No significant difference in permanent deformation or moisture susceptibility was found in mixtures containing waste fibers compared to cellulose or polyester. Also, the tire, carpet, and polyester fibers significantly improved the toughness of the mixtures compared to the cellulose fibers.

An Expanded Maize Gene Expression Atlas based on RNA Sequencing and its Use to Explore Root Development

Abstract: Comprehensive and systematic transcriptome profiling provides valuable insight into biological and developmental processes that occur throughout the life cycle of a plant. We have enhanced our previously published microarray-based gene atlas of maize ( L.) inbred B73 to now include 79 distinct replicated samples that have been interrogated using RNA sequencing (RNA-seq). The current version of the atlas includes 50 original array-based gene atlas samples, a time-course of 12 stalk and leaf samples postflowering, and an additional set of 17 samples from the maize seedling and adult root system. The entire dataset contains 4.6 billion mapped reads, with an average of 20.5 million mapped reads per biological replicate, allowing for detection of genes with lower transcript abundance. As the new root samples represent key additions to the previously examined tissues, we highlight insights into the root transcriptome, which is represented by 28,894 (73.2%) annotated genes in maize. Additionally, we observed remarkable expression differences across both the longitudinal (four zones) and radial gradients (cortical parenchyma and stele) of the primary root supported by fourfold differential expression of 9353 and 4728 genes, respectively. Among the latter were 1110 genes that encode transcription factors, some of which are orthologs of previously characterized transcription factors known to regulate root development in (L.) Heynh., while most are novel, and represent attractive targets for reverse genetics approaches to determine their roles in this important organ. This comprehensive transcriptome dataset is a powerful tool toward understanding maize development, physiology, and phenotypic diversity.

Oil and Conflict: What Does the Cross Country Evidence Really Show?

Abstract: This paper re-examines the effect of oil wealth on political violence. Using a unique historical panel dataset of oil discoveries, we show that simply controlling for country fixed effects removes the statistical association between the value of oil reserves and civil war onset. Other macro-political violence measures, such as coup attempts, are also uncorrelated with oil wealth. To further address endogeneity concerns, we exploit changes in oil reserves due to randomness in the success of oil explorations. We find little robust evidence that oil discoveries increase the likelihood of political violence. Rather, oil discoveries increase military spending in nondemocratic countries. (JEL D74, H56, O17, Q34, Q41) D oes oil wealth corrupt or strengthen regimes? The conventional wisdom dating back to at least Malthus is that resource scarcity triggers conflict. Since the end of the Cold War, however, resource abundance—particularly when that resource is oil—has been blamed for many civil wars in developing countries, and for political instability in the Middle East. If civil strife is caused by resource scarcity and poverty, why should oil revenues weaken states by fueling separatism and causing political instability? The puzzle is intensified by another popular argument for the oil curse—oil wealth enhances the stability and durability of authoritarian regimes because it strengthens dictators by funding patronage and repressive apparatuses. This paper uses data on historical oil explorations and discoveries to provide new evidence on the effect of oil wealth on political violence. In particular, we re-examine the “oil-fuels-war” hypothesis, and provide the first systematic analysis of the impact of oil wealth on coup attempts, irregular leadership transitions, and military spending, using a unique industrial dataset describing worldwide oil explorations, discoveries, extractions, and endowments since 1930.