3,422 research outputs found
Terrorism and the global supply chain: where are your weak links?
For many years, managers have chosen to ignore the risks associated with acts of terrorism that can potentially and catastrophically affect the global supply chain. As producers and suppliers become more tightly tied through long term relationships, common communications and information technology, events affecting one member of the supply chain can have a profound impact on the ability of the rest of the network to operate. The purpose of this discourse is to highlight the linkages which leave a supply chain vulnerable in the case of direct or indirect disruption caused by unexpected terrorist activity
Predicting Residential Satisfaction: A Comparative Case Study
This is a comparative case study that focuses on resident satisfaction in three buildings renovated for housing. A survey based on environment-behavior factors that can contribute to resident satisfaction was developed and distributed to the buildings\u27 residents. Residents in fifty-two percent (52.5%) of the units in the three buildings responded (N = 64). Index variables used were: management, perception, wayfinding, safety. comfort. and adequacy. There was a significant relationship between resident satisfaction and age for one building. Safety and perception were significant for all buildings. Safety, perception and comfort were significant in different ways for each of the three buildings
Parasites Alter Community Structure
Parasites often play an important role in modifying the physiology and behavior of their hosts and may, consequently, mediate the influence hosts have on other components of an ecological community. Along the northern Atlantic coast of North America, the dominant herbivorous snail Littorina littorea structures rocky intertidal communities through strong grazing pressure and is frequently parasitized by the digenean trematode Cryptocotyle lingua. We hypothesized that the effects of parasitism on host physiology would induce behavioral changes in L. littorea, which in turn would modulate L. littorea\u27s influence on intertidal community composition. Specifically, we hypothesized that C. lingua infection would alter the grazing rate of L. littorea and, consequently, macroalgal communities would develop differently in the presence of infected versus uninfected snails. Our results show that uninfected snails consumed 40% more ephemeral macroalgal biomass than infected snails in the laboratory, probably because the digestive system of infected snails is compromised by C. lingua infection. In the field, this weaker grazing by infected snails resulted in significantly greater expansion of ephemeral macroalgal cover relative to grazing by uninfected snails. By decreasing the per-capita grazing rate of the dominant herbivore, C. lingua indirectly affects the composition of the macroalgal community and may in turn affect other species that depend on macroalgae for resources or habitat structure. In light of the abundance of parasites across systems, we suggest that, through trait-mediated indirect effects, parasites may be a common determinant of structure in ecological communities
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Phase Chemistry of Tank Sludge Residual Components
About four or five distinct reprocessing technologies were used at various times in Hanford's history. After removing U and Pu (or later 137Cs and 90Sr), the strongly acidic HLW was ''neutralized'' to high pH (>13) and stored in steel-lined tanks. High pH was necessary to prevent tank corrosion. While each technology produced chemically distinct waste, all wastes were similar in that they were high pH, concentrated, aqueous solutions. Dominant dissolved metals were Fe and/or Al, usually followed by Ni, Mn, or Cr. In an effort to reduce waste volume, many of the wastes were placed in evaporators or allowed to ''self-boil'' from the heat produced by their own radioactive decay. Consequently, today's HLW has been aging at temperatures ranging from 20 to 160 C. Previous studies of synthetic HLW sludge analogues have varied in their exact synthesis procedures and recipes, although each involved ''neutralization'' of acidic nitrate salt solutions by concentrated NaOH. Some recipes included small amounts of Si, SO4 2-, CO3 2-, and other minor chemical components in the Hanford sludges. The work being conducted at the University of Colorado differs from previous studies and from parallel current investigations at Sandia National Laboratories in the simplicity of the synthetic sludge we are investigating. We are emphasizing the dominant role of Fe and Al, and secondarily, the effects of Ni and Si on the aging kinetics of the solid phases in the sludge
Moving interpretations : using drama-based arts strategies to deepen learning about The diary of a young girl.
Three drama-based arts strategies enhanced middle grades teachers’ and students’ engagement with Anne Frank’s diary and historical circumstances
Evaluating Disparities in the U.S. Technology Transfer Ecosystem to Improve Bench to Business Translation
Background: A large number of highly impactful technologies originated from academic research, and the transfer of inventions from academic institutions to private industry is a major driver of economic growth, and a catalyst for further discovery. However, there are significant inefficiencies in academic technology transfer. In this work, we conducted a data-driven assessment of translational activity across United States (U.S.) institutions to better understand how effective universities are in facilitating the transfer of new technologies into the marketplace. From this analysis, we provide recommendations to guide technology transfer policy making at both the university and national level.
Methods: Using data from the Association of University Technology Managers U.S. Licensing Activity Survey, we defined a commercialization pipeline that reflects the typical path intellectual property takes; from initial research funding to startup formation and gross income. We use this pipeline to quantify the performance of academic institutions at each step of the process, as well as overall, and identify the top performing institutions via mean reciprocal rank. The corresponding distributions were visualized and disparities quantified using the Gini coefficient.
Results: We found significant discrepancies in commercialization activity between institutions; a small number of institutions contribute to the vast majority of total commercialization activity. By examining select top performing institutions, we suggest improvements universities and technology transfer offices could implement to emulate the environment at these high-performing institutions.
Conclusion: Significant disparities in technology transfer performance exist in which a select set of institutions produce a majority share of the total technology transfer activity. This disparity points to missed commercialization opportunities, and thus, further investigation into the distribution of technology transfer effectiveness across institutions and studies of policy changes that would improve the effectiveness of the commercialization pipeline is warranted
The Effect of Substructure on Mass Estimates of Galaxies
Large galaxies are thought to form hierarchically, from the accretion and
disruption of many smaller galaxies. Such a scenario should naturally lead to
galactic phase-space distributions containing some degree of substructure. We
examine the errors in mass estimates of galaxies and their dark halos made
using the projected phase-space distribution of a tracer population (such as a
globular cluster system or planetary nebulae) due to falsely assuming that the
tracers are distributed randomly. The level of this uncertainty is assessed by
applying a standard mass estimator to samples drawn from 11 random realizations
of galaxy halos containing levels of substructure consistent with current
models of structure formation. We find that substructure will distort our mass
estimates by up to ~20% - a negligible error compared to statistical and
measurement errors in current derivations of masses for our own and other
galaxies. However, this represents a fundamental limit to the accuracy of any
future mass estimates made under the assumption that the tracer population is
distributed randomly, regardless of the size of the sample or the accuracy of
the measurements.Comment: 9 pages, 8 figures, Astrophysical Journal, in pres
Trophic Cascades, Nutrients, and Lake Productivity: Whole-Lake Experiments
Responses of zooplankton, pelagic primary producers, planktonic bacteria, and CO2 exchange with the atmosphere were measured in four lakes with contrasting food webs under a range of nutrient enrichments during a seven-year period. Prior to enrichment, food webs were manipulated to create contrasts between piscivore dominance and planktivore dominance. Nutrient enrichments of inorganic nitrogen and phosphorus exhibited ratios of N:P \u3e 17:1, by atoms, to maintain P limitation. An unmanipulated reference lake, Paul Lake, revealed baseline variability but showed no trends that could confound the interpretation of changes in the nearby manipulated lakes. Herbivorous zooplankton of West Long Lake (piscivorous fishes) were large-bodied Daphnia spp., in contrast to the small-bodied grazers that predominated in Peter Lake (planktivorous fishes). At comparable levels of nutrient enrichment, Peter Lake\u27s areal chlorophyll and areal primary production rates exceeded those of West Long Lake by factors of approximately three and six, respectively. Grazers suppressed pelagic primary producers in West Long Lake, relative to Peter Lake, even when nutrient input rates were so high that soluble reactive phosphorus accumulated in the epilimnions of both lakes during summer. Peter Lake also had higher bacterial production (but not biomass) than West Long Lake. Hydrologic changes that accompanied manipulation of East Long Lake caused concentrations of colored dissolved organic carbon to increase, leading to considerable variability in fish and zooplankton populations. Both trophic cascades and water color appeared to inhibit the response of primary producers to nutrients in East Long Lake. Carbon dioxide was discharged to the atmosphere by Paul Lake in all years and by the other lakes prior to nutrient addition. During nutrient addition, only Peter Lake consistently absorbed CO2 from the atmosphere, due to high rates of carbon fixation by primary producers. In contrast, CO2 concentrations of West Long Lake shifted to near-atmospheric levels, and net fluxes were near zero, while East Long Lake continued to discharge CO2 to the atmosphere
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