High Percentages of Reclaimed Asphalt Affect the Performance of Asphalt Binder

More than 90 percent of the road and highway network in the United States is paved with asphalt concrete. Maintenance and periodic rehabilitation require a continuous supply of aggregates and asphalt binder, both of which are becoming increasingly scarce and expensive. Recycling and reusing these resources can reduce costs and improve sustainability. The most common recyclable material used in road construction is reclaimed asphalt pavement (RAP), which is milled asphalt surface layers that have been removed from existing pavements before new asphalt overlay is placed. Reclaimed asphalt roofing shingles (RAS) are another potential source of asphalt binder.There is growing interest in allowing significantly higher percentages of RAP and RAS in asphalt mixes used on state and local roadways. However, making this change has raised concerns regarding how these composite binders may influence the performance and durability of asphalt mixes, depending on the blends of different virgin and reused binders. Researchers at the UC Pavement Research Center investigated the use of higher percentages of RAP and RAS as a partial replacement for the virgin binder in new asphalt mixes and their effect on pavement performance in California. This research brief summarizes findings from that study.View the NCST Project Webpag

Interplay of spatial dynamics and local adaptation shapes species lifetime distributions and species-area relationships

The distributions of species lifetimes and species in space are related, since species with good local survival chances have more time to colonize new habitats and species inhabiting large areas have higher chances to survive local disturbances. Yet, both distributions have been discussed in mostly separate communities. Here, we study both patterns simultaneously using a spatially explicit, evolutionary community assembly approach. We present and investigate a metacommunity model, consisting of a grid of patches, where each patch contains a local food web. Species survival depends on predation and competition interactions, which in turn depend on species body masses as the key traits. The system evolves due to the migration of species to neighboring patches, the addition of new species as modifications of existing species, and local extinction events. The structure of each local food web thus emerges in a self-organized manner as the highly non-trivial outcome of the relative time scales of these processes. Our model generates a large variety of complex, multi-trophic networks and therefore serves as a powerful tool to investigate ecosystems on long temporal and large spatial scales. We find that the observed lifetime distributions and species-area relations resemble power laws over appropriately chosen parameter ranges and thus agree qualitatively with empirical findings. Moreover, we observe strong finite-size effects, and a dependence of the relationships on the trophic level of the species. By comparing our results to simple neutral models found in the literature, we identify the features that are responsible for the values of the exponents.Comment: Theor Ecol (2019

Deep learning extends de novo protein modelling coverage of genomes using iteratively predicted structural constraints

The inapplicability of amino acid covariation methods to small protein families has limited their use for structural annotation of whole genomes. Recently, deep learning has shown promise in allowing accurate residue-residue contact prediction even for shallow sequence alignments. Here we introduce DMPfold, which uses deep learning to predict inter-atomic distance bounds, the main chain hydrogen bond network, and torsion angles, which it uses to build models in an iterative fashion. DMPfold produces more accurate models than two popular methods for a test set of CASP12 domains, and works just as well for transmembrane proteins. Applied to all Pfam domains without known structures, confident models for 25% of these so-called dark families were produced in under a week on a small 200 core cluster. DMPfold provides models for 16% of human proteome UniProt entries without structures, generates accurate models with fewer than 100 sequences in some cases, and is freely available.Comment: JGG and SMK contributed equally to the wor

Local quantum critical point in the pseudogap Anderson model: finite-T dynamics and omega/T scaling

The pseudogap Anderson impurity model is a paradigm for locally critical quantum phase transitions. Within the framework of the local moment approach we study its finite-T dynamics, as embodied in the single-particle spectrum, in the vicinity of the symmetric quantum critical point (QCP) separating generalized Fermi-liquid (Kondo screened) and local moment phases. The scaling spectra in both phases, and at the QCP itself, are obtained analytically. A key result is that pure omega/T-scaling obtains at the QCP, where the Kondo resonance has just collapsed. The connection between the scaling spectra in either phase and that at the QCP is explored in detail.Comment: 12 pages, 7 figure

An Economic Evaluation of Research into the Improved Management of the Annual Grass Weed Vulpia in Temperate Pastures in South-Eastern Australia

NSW Agriculture has a history of research investment in managing weed problems in the temperate pasture areas. One focus of that research has been on the development of improved management practices for the major annual grass weed vulpia. Recent surveys have found that weeds comprised up to 80% of pasture biomass in some temperate areas and that typical vulpia contents are between 30 and 40% of pasture biomass. Temperate pasture degradation is recognised as being a major contributor to the wider environmental problems of soil erosion, salinity and acidity. This evaluation related to a project (1996-2002) that focussed on the vulpia problem in the New South Wales temperate pasture areas. The benefits of that research were measured as the difference in the economic returns from the project (the with-research scenario) and those that would have resulted if the project had not been initiated (the without-research scenario). The results indicated high levels of economic benefits from the vulpia project. The annual net project benefit had a mean value of $58 million. The benefit-cost analysis generated a mean NPV of$196.9 million and a mean BCR of 22.2. These results demonstrate that research by NSW Agriculture into the improved management of vulpia has the potential to generate substantial long-term economic benefits. Other socio-economic aspects of the results showed that wool producers outside the New South Wales temperate areas lost economic surplus (from a mean -$21.7 million to -$47.8 million) because they were unable to adopt the cost-reducing technology and faced a reduced wool price. All wool consumers gained from vulpia research because of expanded wool production and lower wool prices. Improved vulpia management is also considered to produce important environmental benefits by encouraging a greater use of deep-rooted perennial grasses and the beneficial effects of these on mitigating soil problems and reducing water table discharges.benefit cost analysis, research evaluation, annual grass weeds, vulpia, Research and Development/Tech Change/Emerging Technologies, Q160,

Domestic Habits of Two Flies

Recent observations indicate that, on two occasions at least, two species of wild flies came into houses and acted like species we regard as house flies. The two species are: Cochliomyia americana Cushing and Patton and Ceratoxys latiuscula (Loew), which will be discussed in the order above. Cochliomyia americana, the screw-worm fly, a Calliphorid, is usually a wild elusive, swift-flying, out-of-door creature, occasionally attacking man, but more frequently ovipositing in the wounds of domestic animals. In Utah the closest they were found to a dwelling was when two were captured feeding on a fresh deer head in a garbage can near a backdoor. In all my Iowa collecting, except at Adair, I have found this species out-of-doors and wild

The Histology of the Digestive Tract of the Cluster Fly, Pollenia rudis

Pollenia rudis (Fabricius), the cluster fly, is a common household pest in Iowa in the fall, winter, and early spring. This house fly is readily distinguished from Musca domestica L. by its thoracic pubescence of fine crinkled golden hairs, its sluggish, almost tame habits, and its parasitizing woodland earthworms of the genus Helodrilus (De Coursey 1927) instead of breeding in horse manure. The flies were readily available indoors at Ames throughout the winter, as they emerged a few at a time from hibernation in window crevices, from moldings, and from behind furniture

An Ecological Survey, as a Means of Obtaining a Background for Certain Morphological Problems

The dissection of a specimen in the laboratory needs to be supplemented by a stimulating and enriching background gained in the field. Structure is to a greater or less degree associated with function, and, disregarding the disputed effect of environment upon heredity, changes in environment can modify the functioning of somatic structures in the lifetime of a single individual. Furthermore, a morphologist, who supplements his laboratory work with ecological observation, has the pleasure of seeing in action the structures with which he works, gains the perspective which his problem should have with other problems, and discovers further channels for research in his chosen field

A comparative study of certain goblet cells

journal articleThe origin of the primordial droplets has been rightly given the primary place in the study of secretion. Bowen has limited the term secretion to the actual synthesis of these droplets from cytoplasmic materials, which limitation we shall accept. The secondary problems in this field concern chieflly extrusion or storage of these elaborated secretions. While we shall review the literature concerning goblet cells in both fields, our contributions will lie for the most part in the secondary field

Two protozoans from Great Salt Lake

journal articleThe amoeba inhabiting the waters of Great Salt Lake, which has been previously referred to Amoeba Umax (Dujard in) . Named for mv colleague at the University of Utah, Dr. Seville Flowers. Type localtiv, Garfield Beach, Great Salt Lake, Utah. Type figures 1 to 3. Small amoebae, 18 to 40 micra in diameter. Nucleus (n of fig. 2) obscure, appearing of the compact type, finely granular when stained with methylene blue. Nucleus often obscured both by food particles of a similar size and by pink and green algal cells in the cytoplasm, the green ones (a of fig. 1) probably symbiotic. The pink algal cells break down into clusters of angular granules of a bright red color (roffig-3). Dr. Flowers suggests that the intensification of the color nuiy be due to the pH of the cytoplasm