Construction of Full-Depth Asphaltic Concrete Pavements

Considerable attention has been devoted to the design and use of full-depth asphaltic concrete pavements. An experimental full-depth pavement was constructed on the Cannonsburg-Ashland Road (US 60), and the mechanical response of each asphaltic concrete layer to static and dynamic loading has been tested during construction. This report is a documentation of section designs and construction procedures and summarily presents construction test results to be used in future analyses

Geology of the East Lake Creek Area, Eagle County, Colorado

The East Lake Creek area is in the northwest part of central Colorado, west of the Continental Divide. The area consists of about 40 square miles of Paleozoic sedimentary rocks which dip off the extreme north end of the Sawatch Range. The medium-grained, nearly white Upper Cambrian Sawatch quartzite is about 190 feet thick, and grades into brown, sandy dolomite of the Peerless formation which is 80 to 100 feet thick. The Lower Ordovician Manitou dolomite rests unconformably on the Peerless, and is dark gray and medium to coarsely crystalline. The Manitou is absent east of East Lake Creek, but is up to 40 feet in thickness to the west. It is separated by an angular unconformity from the Middle Ordovician Harding quartzite. The Harding is a nearly white, medium-grained orthoquartzite with some grayish yellow green sandstone lenses, and is up to 20 feet in thickness. A prominent unconformity separates the Ordovician sediments from the Upper Devonian Chaffee formation. The white, vitreous, coarse-grained Parting quartzite member is about 75 feet thick. It differs from the quartzites of the Sawatch and Harding by its coarseness and more angular grains. The upper member of the Chaffee formation is the Dyer dolomite, which is uniform, finely crystalline, light gray, and approximately 100 feet thick. The Mississippian Leadville limestone disconformably overlies the Dyer, and is a gray, lithographic limestone, varying from 70 to 120 feet in thickness. The base of the Leadville is a grayish brown, dolomitic sandstone locally called the Gilman member. The Belden formation of Early Pennsylvanian age disconformably overlies the Leadville. It is about 400 feet thick, and is composed of alternating beds of dark gray, aphanitic limestone and gray to black, fissile shale. It is highly fossiliferous, while the older sediments yielded no fossils. Its fauna includes abundant specimens belonging to the genera Amphissites, Millerella, Climacammina, Lophophyllidium, Stereostylus, Fenestrellina, Rhombopora, Chonetes, Marginifera, Dictyoclostus, Spirifer, Composita, Echinocrinus, Stylophycus, and several others which were not identified. Abundant Millerella occur in a zone 100 feet thick above the middle of the formation. The presence of the Millerella, and the absence of more advanced fusulinids has led to the conclusion that at least this part of the Belden is of Morrowan age. The Belden grades into the Minturn formation which contains about 1000 feet of gray and brown, micaceous siltstones, fine to coarse gray sandstones, and thin partings of gray shale. This lower zone is overlain by several hundred feet of gray, massive beds of gypsum and anhydrite, with thin beds of dolomite, siltstone, and shale. Two reverse faults and one anticline trend about N45E across the southern part of the area; the faults have stratigraphic throws of 1200 to 1500 feet and can be traced for about 8 miles, and the anticline can be traced for about 5 miles. The structures all appear to be the result of a local compressive force applied to the sediments during the uplift of the Sawatch Range

Comparative Evaluation of RAYGO 404 Vibratory Roller

Roller evaluations are rather phenomenological -- that is, one must rely somewhat on observations. Density measurements following each excursion of the compactor may not relate directly to the work done in compressing the layer. When no increase in density is realized, no work is accomplished. Work is defined here in the classical sense. Energy expended without producing an increase in density is wasted. Thereafter, the only way additional classical work can be done on the layer is to reduce density. The number of excursions necessary to achieve an acceptable or comparable density generally reflects efficiency of the compactor. Much may depend on weight, speed, size of wheels, and modes of operation. When viscous traction (time-dependent resistance to densification) is involved, the dwell time (or dwell time x number of excursions) becomes very significant. Dwell time is proportional to speed; but, in a vibrating mode, bearing stress of the roller wheel varies

Weigh Station Bypassing

A Study was initiated in May of 1990 to investigate the problem of trucks bypassing or avoiding weigh/enforcement stations in Kentucky. A literature review identified two major studies (Wisconsin and Florida) on the subject, both of which are summarized in this report. In addition, a 1989, limited-scope study of truck bypassing of weigh stations in Kentucky was reviewed and summarized. The primary data collection effort for this study took place in the fall of 1990, centered around the Simpson County enforcement station on Interstate-55. Three potential bypass routes were identified. Automatic vehicle classification (AVC) and weight-in-motion (WIM) equipment was installed on 1-65 and on all three bypass routes. Data collection took place over a three-week period, with enforcement on the bypass routes during the second week. Significant conclusions of the study include: 1) While weigh station bypassing does occur in Kentucky, there was no indication of significant numbers of trucks modifying their route choices due to enforcement activity on the bypass routes; 2) Average truck weights and the percentage of trucks overweight are higher on bypass routes than on Interstate routes, but this is not primarily a result of bypassing activity; 3) The majority of trucks on bypass routes have legitimate reasons (in terms of origin or destination) to be on those routes; 4) A high percentage of trucks on bypass routes have violations, regardless of whether the trucks have a local origin/destination along the route; 5) The most common inspection violations on bypass routes are safety-related equipment violations, followed by driver violations; 6) Temporary enforcement efforts on bypass routes can be effective and can be self-supporting through citation revenues; 7) Due to accuracy limitations, high speed WIM data may not be appropriate for certain uses. The following recommendations were developed: 1) A statewide enforcement plan should be developed with increased emphasis on enforcement for non- Interstate routes; 2) Innovative options should be investigated to simplify or expedite weigh station operations; 3) Enforcement efforts on non-Interstate routes should be randomized and unpredictable and should include weighing of trucks; 4) Effectiveness measures should be developed and used to monitor non-Interstate enforcement efforts; 5) The accuracy of statewide WIM data should be assessed; 6) The potential for using statewide WIM data to identify problem areas and direct enforcement efforts should be explored, and a formal process should be established to foster this cooperative effort

Advanced sensors technology survey

This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed

Truck Design and Usage Related to Highway Pavement Performance

The function of a pavement is to serve traffic safely, comfortably, and efficiently at reasonable costs. Automobile traffic typically accounts for the major volume of traffic using high-type facilities. However, heavy truck traffic accounts for the major portion of accumulated fatigue and therefore requires greater structural designs. Truck design and usage has tended toward larger vehicles and greater payloads. The impact of elements of truck design and usage (such as suspension systems, floating axles, axle configurations, uniformity of loading, payloads, etc.) on fatigue damage are illustrated. The effects of increasing vehicle loadings and increased tire pressures are related to potential for rutting of asphaltic concrete pavements. Mechanisms for implementation of vehicle damage factors and accumulated pavement fatigue in the assessment and allocation of costs to highway users also are presented

Closing achievement gaps: Roles and tasks of elementary school counselors

Achievement gaps among racial‐ethnic and socioeconomic status groups are an enduring, pervasive, and multifaceted phenomenon. Therefore, efforts aimed at understanding and addressing these gaps must be developmentally and environmentally broad, involving numerous school counselor roles and tasks, including leadership, advocacy, collaboration, and strategic interventions. In this article, we first document achievement gap trends and then provide a framework for understanding and sequencing outcomes that quantify student achievement gaps. Finally, we present research that identifies critical variables influencing achievement gaps and important school counselor roles and tasks aimed at closing these gaps. The article focuses on outcomes across the developmental spectrum from elementary school through postsecondary education

Telomerase and breast cancer

Current therapies for breast cancer include treatments that are toxic and often result in drug resistance. Telomerase, a cellular reverse transcriptase that maintains the ends of chromosomes (telomeres), is activated in the vast majority of breast cancers (over 90% of breast carcinomas) but not in normal adjacent tissues. Telomerase is thus an attractive target for both diagnosis and therapy because of its distinct pattern of expression. We address the use of telomerase in the diagnostics of breast pathology, as well as the use of telomerase inhibitors in the treatment and prevention of breast cancer

Super-resolution fight club: assessment of 2D and 3D single-molecule localization microscopy software

With the widespread uptake of two-dimensional (2D) and three-dimensional (3D) single-molecule localization microscopy (SMLM), a large set of different data analysis packages have been developed to generate super-resolution images. In a large community effort, we designed a competition to extensively characterize and rank the performance of 2D and 3D SMLM software packages. We generated realistic simulated datasets for popular imaging modalities—2D, astigmatic 3D, biplane 3D and double-helix 3D—and evaluated 36 participant packages against these data. This provides the first broad assessment of 3D SMLM software and provides a holistic view of how the latest 2D and 3D SMLM packages perform in realistic conditions. This resource allows researchers to identify optimal analytical software for their experiments, allows 3D SMLM software developers to benchmark new software against the current state of the art, and provides insight into the current limits of the field

The emergence and diversification of a zoonotic pathogen from within the microbiota of intensively farmed pigs

The expansion and intensification of livestock production is predicted to promote the emergence of pathogens. As pathogens sometimes jump between species, this can affect the health of humans as well as livestock. Here, we investigate how livestock microbiota can act as a source of these emerging pathogens through analysis of Streptococcus suis, a ubiquitous component of the respiratory microbiota of pigs that is also a major cause of disease on pig farms and an important zoonotic pathogen. Combining molecular dating, phylogeography, and comparative genomic analyses of a large collection of isolates, we find that several pathogenic lineages of S. suis emerged in the 19th and 20th centuries, during an early period of growth in pig farming. These lineages have since spread between countries and continents, mirroring trade in live pigs. They are distinguished by the presence of three genomic islands with putative roles in metabolism and cell adhesion, and an ongoing reduction in genome size, which may reflect their recent shift to a more pathogenic ecology. Reconstructions of the evolutionary histories of these islands reveal constraints on pathogen emergence that could inform control strategies, with pathogenic lineages consistently emerging from one subpopulation of S. suis and acquiring genes through horizontal transfer from other pathogenic lineages. These results shed light on the capacity of the microbiota to rapidly evolve to exploit changes in their host population and suggest that the impact of changes in farming on the pathogenicity and zoonotic potential of S. suis is yet to be fully realized