28 research outputs found
Intelligent Compaction of Soils—Data Interpretation and Role in QC/QA Specifications
This report describes a study of intelligent compaction (IC) technologies, within the context of actual construction projects, for its potential as a component of INDOT’s QC/QA for soils. The output from an IC-equipped roller compaction equipment is a real-time area mapping of the compacted lift stiffness as captured by the IC measure. Data was collected to evaluate the correlation between each of two IC measures—compaction meter value (CMV) and machine drive power (MDP)—and in situ embankment quality test measures, the chief in situ test being the dynamic cone penetrometer (DCP) test which INDOT uses for soil embankment acceptance testing. Researchers sought to understand how well the IC measures might assess embankment quality as currently evaluated by the in situ measures. Window-averaged IC measures were compared with the in situ DCP test points. For CMV, a variable correlation was found between the average CMV and DCP values from 74 in situ locations. Also, a limited head-to-head comparison of CMV and MDP with the in situ measures provided some indication that MDP should be studied further. Lessons were learned regarding the elimination of bias in future correlation studies, critical provisions to facilitate best data quality, and important aspects of data management. IC technology holds promise for monitoring the consistency of the soil compaction effort and flagging weak areas in real time during compaction operations. However, further insight is needed regarding the correlation of the DCP measure with both types of IC measures for various soil characterizations and field moisture conditions
Guidelines for Permitting Overloads, Part 2: Statistical Analysis of Overload Vehicle Effects on Indiana Highway Bridges
This report summarizes an analytical investigation carried out to develop a set of guidelines for regulation of overload vehicles in Indiana. A formula based first phase evaluation of overload permit requests is developed through statistical study of the rating of a representative sample of the highway bridges in Indiana using a representative sample of overload vehicles observed in the state in 1990 and 1991 plus the HS 20 design vehicle and the two Indiana Toll Road loadings. A sample of 148 bridges is chosen from a total population of 3700 Indiana highway bridges using a proportionate stratified random sampling process. A sample of 25 trucks, with the truck parameters uniformly distributed over their ranges is compiled from the 1990 and 1991 truck population (permit vehicles obtained from INDOT and AASHTO HS Design Vehicle). The selected trucks are used to rate bridges in the selected sample using the Bridge Analysis and Rating System (BARS) program at the operating stress level. BARS is based on elastic line girder and truss analysis. The allowable load, W, is subjected to linear regression analysis with several bridge and truck parameters as regressor or independent variables
Tumor-Associated Macrophages Derived from Circulating Inflammatory Monocytes Degrade Collagen through Cellular Uptake
Physiologic turnover of interstitial collagen is mediated by a sequential pathway in which collagen is fragmented by pericellular collagenases, endocytosed by collagen receptors, and routed to lysosomes for degradation by cathepsins. Here, we use intravital microscopy to investigate if malignant tumors, which are characterized by high rates of extracellular matrix turnover, utilize a similar collagen degradation pathway. Tumors of epithelial, mesenchymal, or neural crest origin all display vigorous endocytic collagen degradation. The cells engaged in this process are identified as tumor-associated macrophage (TAM)-like cells that degrade collagen in a mannose receptor-dependent manner. Accordingly, mannose-receptor-deficient mice display increased intratumoral collagen. Whole-transcriptome profiling uncovers a distinct extracellular matrix-catabolic signature of these collagen-degrading TAMs. Lineage-ablation studies reveal that collagen-degrading TAMs originate from circulating CCR2+ monocytes. This study identifies a function of TAMs in altering the tumor microenvironment through endocytic collagen turnover and establishes macrophages as centrally engaged in tumor-associated collagen degradation
Mechanisms of Thermal Adaptation Revealed From the Genomes of the Antarctic Archaea Methanogenium frigidum and Methanococcoides burtonii
We generated draft genome sequences for two cold-adapted Archaea, Methanogenium frigidum and Methanococcoides burtonii, to identify genotypic characteristics that distinguish them from Archaea with a higher optimal growth temperature (OGT). Comparative genomics revealed trends in amino acid and tRNA composition, and structural features of proteins. Proteins from the cold-adapted Archaea are characterized by a higher content of noncharged polar amino acids, particularly Gin and Thr and a lower content of hydrophobic amino acids, particularly Leu. Sequence data from nine methanogen genomes (OGT 15degrees-98degreesC) were used to generate IIII modeled protein structures. Analysis of the models from the cold-adapted Archaea showed a strong tendency in the solvent-accessible area for more Gin, Thr, and hydrophobic residues and fewer charged residues. A cold shock domain (CSD) protein (CspA homolog) was identified in M. frigidum, two hypothetical proteins with CSD-folds in M. burtonii, and a unique winged helix DNA-binding domain protein in M. burtonii. This suggests that these types of nucleic acid binding proteins have a critical role in cold-adapted Archaea. Structural analysis of tRNA sequences from the Archaea indicated that GC content is the major factor influencing tRNA stability in hyperthermophiles, but not in the psychrophiles, mesophiles or moderate thermophiles. Below an OGT of 60degreesC, the GC content in tRNA was largely unchanged, indicating that any requirement for flexibility of tRNA in psychrophiles is mediated by other means. This is the first time that comparisons have been performed with genome data from Archaea spanning the growth temperature extremes. from psychrophiles to hyperthermophile
Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development.
BACKGROUND: We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. RESULTS: The genome has been sequenced to 2 Ă— coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. CONCLUSIONS: Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution
ON SOME RESULTS IN BRANCHING PROCESSES AND GA/G/INFINITY QUEUE WITH AN APPLICATION TO BIOLOGY
This thesis deals with a stochastic model suggested by a life situation, the life cycle of bacteria, as well as a queueing model suggested by the life situation, and some new results in the theory of branching processes which arose out of research into the properties of the model. In Chapter I, we prove certain preliminary results for random measures as well as two strong laws of large numbers. These results are especially useful in Chapter II in proving results for the GA/G/(INFIN) queue, while one strong law is used in Chapter III in proving a theorem for age-dependent branching processes. In Chapter II, the GA/G/(INFIN) queue is introduced. The distinguishing feature of this infinite server queue is that the arrival rate converges to infinity though in a stable sense suggested by results in Chapter I. Various limit theorems are given for this queueing model. In Chapter III, the almost sure convergence of the age distribution to a non-trivial limit is proved for the case when the mean of the offspring distribution is finite for age dependent branching processes. Two interesting corollaries of this fact are also proved concerning growth properties of the process. Chapter IV contains a summary of previous mathematical models of the bacterial life cycle, as well as the postulates of our own model. Chapter V contains some mathematical development of the model as well as some qualitative comparisons with experimental data. In addition, the strengths and weaknesses of the model are presented along with suggestions for further research
Comparison of Various INDOT Testing Methods and Procedures to Quantify Variability in Measured Bituminous and Concrete Properties
This study was designed to analyze the variability associated with several test procedures used by the Indiana Department of Transportation (INDOT) in their Hot Mix Asphalt (HMA), portland cement concrete pavement (PCCP), and superstructure concrete protocols. The aim of this work was to document the variability associated with each of these test procedures toward application of this information of the development of acceptance criteria, pay factors, and pay incentives and disincentives. The studied parameters for HMA production included the air void content and VMA of the gyratory compacted mixture, in-place density, binder (asphalt) content, aggregate bulk specific gravity and water absorption, bulk specific gravity of compacted mixture, and theoretical maximum specific gravity. The analysis of existing INDOT test data and additional Purdue laboratory study indicated that testing variation was within or only slightly above the (1s) AASHTO limits for testing variation. The production variation ranged from 50 to 85% of the total variation depending on the tested parameter. The quality characteristics related to the acceptance program for PCC pavements and superstructure, which were investigated in this study, were plastic air content, flexural strength, and pavement thickness. Aggregate moisture and bulk specific gravity properties were also studied to determine what variations might be expected from a particular source. In addition to the QC/QA properties, compressive strength and split tensile strength of concrete were also studied. Based on the analysis of existing INDOT test data, it was found that all of the testing was within or only slightly above the (1s) AASHTO/ASTM testing variations. The production variation was found to range widely depending on the project. Overall, the study demonstrates that high quality testing is commonly performed in the state of Indiana and illustrates clear benefits of the technician certification programs and INDOT educational and training procedures