1,011 research outputs found
Measurements and Assessment of Structural Members in Selected Spans of Amtrakâs Susquehanna River Bridge
Patterns of Land Use Change, Land Governance, and the Supply of Ecosystem Services in a Multifunctional Landscape: A Case Study from Upstate SC, USA
Urban expansion and development continue to increase globally, threatening rural multifunctional landscapes that provide a diversity of direct and indirect ecological benefits. However, not all landscapes are equally impacted, thus making conservation planning more difficult. We used 8âyears of land use and land cover to understand this change in Greenville Co. SC, a region experiencing rapid expansion of development into rural landscapes. Regression models helped explain the relationships between development predictor variables and rural response variables. To explore where these changes were occurring, we determined which size categories of land parcels were the most developed and how this is changing over time. Developed open space was revealed to significantly impact rural character, pasture, and evergreen forest most frequently. It was also found to be most prevalent in the smallest parcels. Determining relationships between development, rural character, and multifunctionality will aid in potential solutions for the conservation of multifunctional landscapes
Report to the Pennsylvania Tank Collapse Task Force on the Failure of the Ashland Oil Storage Tank
A Global Plate Model Including Lithospheric Deformation Along Major Rifts and Orogens Since the Triassic
Global deepâtime plate motion models have traditionally followed a classical rigid plate approach, even though plate deformation is known to be significant. Here we present a global MesozoicâCenozoic deforming plate motion model that captures the progressive extension of all continental margins since the initiation of rifting within Pangea at ~240 Ma. The model also includes major failed continental rifts and compressional deformation along collision zones. The outlines and timing of regional deformation episodes are reconstructed from a wealth of published regional tectonic models and associated geological and geophysical data. We reconstruct absolute plate motions in a mantle reference frame with a joint global inversion using hot spot tracks for the last 80 million years and minimizing global trench migration velocities and net lithospheric rotation. In our optimized model, net rotation is consistently below 0.2°/Myr, and trench migration scatter is substantially reduced. Distributed plate deformation reaches a Mesozoic peak of 30 Ă 106 km2 in the Late Jurassic (~160â155 Ma), driven by a vast network of rift systems. After a midâCretaceous drop in deformation, it reaches a high of 48 x 106 km2 in the Late Eocene (~35 Ma), driven by the progressive growth of plate collisions and the formation of new rift systems. About a third of the continental crustal area has been deformed since 240 Ma, partitioned roughly into 65% extension and 35% compression. This community plate model provides a framework for building detailed regional deforming plate networks and form a constraint for models of basin evolution and the plateâmantle system
Identification of a selective G1-phase benzimidazolone inhibitor by a senescence-targeted virtual screen using artificial neural networks
Cellular senescence is a barrier to tumorigenesis in normal cells and tumour cells undergo senescence responses to genotoxic stimuli, which is a potential target phenotype for cancer therapy. However, in this setting, mixed-mode responses are common with apoptosis the dominant effect. Hence, more selective senescence inducers are required. Here we report a machine learning-based in silico screen to identify potential senescence agonists. We built profiles of differentially affected biological process networks from expression data obtained under induced telomere dysfunction conditions in colorectal cancer cells and matched these to a panel of 17 protein targets with confirmatory screening data in PubChem. We trained a neural network using 3517 compounds identified as active or inactive against these targets. The resulting classification model was used to screen a virtual library of ~2M lead-like compounds. 147 virtual hits were acquired for validation in growth inhibition and senescence-associated β-galactosidase (SA-β-gal) assays. Among the found hits a benzimidazolone compound, CB-20903630, had low micromolar IC50 for growth inhibition of HCT116 cells and selectively induced SA-β-gal activity in the entire treated cell population without cytotoxicity or apoptosis induction. Growth suppression was mediated by G1 blockade involving increased p21 expression and suppressed cyclin B1, CDK1 and CDC25C. Additionally, the compound inhibited growth of multicellular spheroids and caused severe retardation of population kinetics in long term treatments. Preliminary structure-activity and structure clustering analyses are reported and expression analysis of CB-20903630 against other cell cycle suppressor compounds suggested a PI3K/AKT-inhibitor-like profile in normal cells, with different pathways affected in cancer cells
Adsorption of vapors by silica gels of different structures
1. 1. Isothermals were obtained at 25[deg]C. for the adsorption of the vapors of methyl alcohol, ethyl alcohol, n-propyl alcohol, benzene, carbon tetrachloride, hexane, and water by silica gels of different apparent densities. For certain of these systems additional isotherms at 40 or 45[deg]C. were obtained.2. 2. The specific surface area of each gel was determined by three independent methods as follows: (a) by application of the BET equation to the low temperature nitrogen adsorption isotherms, (b) by the method based upon the assumption of the existence of uniform circular capillaries (i.e., ), and (c) by treatment of the gravimetric data according to the free surface energy method of Fu and Bartell.3. 3. For each system the values of the adhesion tension, work of adhesion, and initial spreading coefficient were calculated from the adsorption data by means of the Gibbs equation which interrelates surface area, surface tension, surface excess and chemical potential.4. 4. It was found that the free surface energy changes which occurred when unit areas of the different porous solids were replaced by unit areas of given solid-liquid or solid-saturated vapor interfaces were independent of the apparent densities of the adsorbent, i.e., the adhesion tension values calculated for a given liquid against a series of silica gels which differed in average pore radius, pore volume, and specific surface area were practically the same.5. 5. Inasmuch as six different organic liquids, possessing widely different surface tensions as well as widely different interaction energies against silica gave for a given gel similar values for surface area, which values were in good agreement with values obtained with other accepted methods, it appears justifiable to conclude that the free surface energy method of Fu and Bartell is generally applicable.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32543/1/0000654.pd
Measurements and Assessment of Stresses in Structural Members of the Saw Mill Run Bridge, Pittsburgh, PA
Branch-selective, iridium-catalyzed hydroarylation of monosubstituted alkenes via a cooperative destabilization strategy
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