114 research outputs found
At the Confluence of Science and Power: Water Struggles of New Orleans in the Nineteenth Century
New Orleans failed to solve its water infrastructure problems in the nineteenth century because a shifting locus of power in a variable political and financial environment hampered wise decision making, while technology choices were limited by contemporary knowledge, scientists\u27 ignorance, or by technicians\u27 poor presentation skills for new ideas. And, selection was often governed by prejudice: personal, racial, or against technology. New Orleans was able to deal with its water difficulties only when those with the power to make or influence decisions had an available technology capable of handling the problem and they chose to use it. Power and science had to flow together. New Orleans\u27 situation is excellent: a crossroads of trade, an entrepot for the agricultural heartland, the Mississippi River\u27s premier port. And yet, the city\u27s site is dreadful. New Orleans sits in a bowl of land rimmed by water, with the river and the brackish Lake Pontchartrain on either side, amid swampy environs in a hot and wet climate. This city exists only because of the complex system by which it deals with water. The conundrum of New Orleans lies at the confluence of science and power. Whoever holds the power can choose the science and technology with which New Orleans handles water, its everpresent best friend and worst enemy. From the colonial era to the twentieth century, the power to make those choices shifted from the private sector to the public sector and back, with the press and, eventually, women ultimately having influence. Under the fading Spanish empire, from the age of Jefferson to the era of Jacksonian democracy, during the Civil War and Reconstruction, through the dawn of Progressivism: New Orleans confronted the problems of flood prevention, drainage, the omni-present need for a dependable water source for its citizens, and eventually sewerage disposal. This study investigates how those problems were faced, what technology was used and how the work was financed; and also illuminates the lives of those who dealt with New Orleans and water during that time
Trickle by trickle: municipalization of the New Orleans water system in the nineteenth and early twentieth centuries
Regionalism is being explored by a wide variety of community players who include representatives from the public, private, and not-for-profit sectors (Dodge 1996, 1). Intermunicipal agreements, county service expansion, new region-wide special purpose governments, and multi-sector coalitions of civic regionalists have proliferated throughout the country during the last decade, even though the benefits of regional cooperation remain elusive in many ways (Foster 1997, 375). Hence, the question remains: Do greater metropolitan planning efforts lead to higher levels of community prosperity and quality? Nelson and Foster (1999) have found some evidence that more coordinated regional governing structures, particularly regional utilities, seem to promote higher levels of economic welfare. But more coordination in service delivery does not necessarily stem from, or lead to, more coordination in planning. In fact, Foster (1997) has pointed out that it is easier for regions to develop coordinative mechanisms around systems maintenance functions, such as transportation and sewer system operation. However, these represent only two of the many inputs that are required to generate local investment and business growth. This paper attempts to answer the question
First Spitzer Space Telescope Observations of Magnetic Cataclysmic Variables: Evidence for Excess Emission at 3--8 microns
We present the first observations of magnetic cataclysmic variables with the
Spitzer Space Telescope. We used the Infrared Array Camera to obtain photometry
of the polars EF Eri, GG Leo, V347 Pav, and RX J0154.0-5947 at 3.6, 4.5, 5.8,
and 8.0 m. In all of our targets, we detect excess mid-infrared emission
over that expected from the component stars alone. We explore the origin of
this IR excess by examining bremsstrahlung, cyclotron emission, circumbinary
dust, and L/T brown dwarf secondary stars. Bremsstrahlung and cyclotron
emission appear unlikely to be significant contributors to the observed fluxes.
At present, the most likely candidate for the excess emission is dust that is
probably located in a circumbinary disk with an inner temperature near 800 K.
However, a simple dust disk plus any reasonable low mass or brown dwarf-like
secondary star is unable to fully explain the observed flux densities in the
3--8 m region.Comment: Accepted to ApJ Letter
The Ursinus Weekly, May 8, 1975
From the cluttered desk of the U.S.G.A. President • Band finishes • B.C. to A.D. • Record review: Straight shooter - Bad Company • Letters to the editor • Parents\u27 Day plea: Donations for care • Spring Parents\u27 Day events scheduled • Track team takes fourth • Lantern elects • Placement Office active for students • Award to Noar • Telethon • Night school • How to Succeed • Suds abound in Shampoo • Baseball drops two • Girls winhttps://digitalcommons.ursinus.edu/weekly/1038/thumbnail.jp
Role of "external facilitation" in implementation of research findings: a qualitative evaluation of facilitation experiences in the Veterans Health Administration
BACKGROUND: Facilitation has been identified in the literature as a potentially key component of successful implementation. It has not, however, either been well-defined or well-studied. Significant questions remain about the operational definition of facilitation and about the relationship of facilitation to other interventions, especially to other change agent roles when used in multi-faceted implementation projects. Researchers who are part of the Quality Enhancement Research Initiative (QUERI) are actively exploring various approaches and processes, including facilitation, to enable implementation of best practices in the Veterans Health Administration health care system – the largest integrated healthcare system in the United States. This paper describes a systematic, retrospective evaluation of implementation-related facilitation experiences within QUERI, a quality improvement program developed by the US Department of Veterans Affairs. METHODS: A post-hoc evaluation was conducted through a series of semi-structured interviews to examine the concept of facilitation across several multi-site QUERI implementation studies. The interview process is based on a technique developed in the field of education, which systematically enhances learning through experience by stimulating recall and reflection regarding past complex activities. An iterative content analysis approach relative to a set of conceptually-based interview questions was used for data analysis. FINDINGS: Findings suggest that facilitation, within an implementation study initiated by a central change agency, is a deliberate and valued process of interactive problem solving and support that occurs in the context of a recognized need for improvement and a supportive interpersonal relationship. Facilitation was described primarily as a distinct role with a number of potentially crucial behaviors and activities. Data further suggest that external facilitators were likely to use or integrate other implementation interventions, while performing this problem-solving and supportive role. PRELIMINARY CONCLUSIONS: This evaluation provides evidence to suggest that facilitation could be considered a distinct implementation intervention, just as audit and feedback, educational outreach, or similar methods are considered to be discrete interventions. As such, facilitation should be well-defined and explicitly evaluated for its perceived usefulness within multi-intervention implementation projects. Additionally, researchers should better define the specific contribution of facilitation to the success of implementation in different types of projects, different types of sites, and with evidence and innovations of varying levels of strength and complexity
Observations of V592 Cassiopeiae with the Spitzer Space Telescope - Dust in the Mid-Infrared
We present the ultraviolet-optical-infrared spectral energy distribution of
the low inclination novalike cataclysmic variable V592 Cassiopeiae, including
new mid-infrared observations from 3.5-24 microns obtained with the Spitzer
Space Telescope. At wavelengths shortward of 8 microns, the spectral energy
distribution of V592 Cas is dominated by the steady state accretion disk, but
there is flux density in excess of the summed stellar components and accretion
disk at longer wavelengths. Reproducing the observed spectral energy
distribution from ultraviolet to mid-infrared wavelengths can be accomplished
by including a circumbinary disk composed of cool dust, with a maximum inner
edge temperature of ~500 K. The total mass of circumbinary dust in V592 Cas
(~10^21 g) is similar to that found from recent studies of infrared excess in
magnetic CVs, and is too small to have a significant effect on the long-term
secular evolution of the cataclysmic variable. The existence of circumbinary
dust in V592 Cas is possibly linked to the presence of a wind outflow in this
system, which can provide the necessary raw materials to replenish the
circumbinary disk on relatively short timescales, and/or could be a remnant
from the common envelope phase early in the formation history of the system.Comment: Accepted for publication in the Astrophysical Journa
Cysteine Redox Potential Determines Pro-Inflammatory IL-1β Levels
Cysteine (Cys) and its disulfide, cystine (CySS) represent the major extracellular thiol/disulfide redox control system. The redox potential (E(h)) of Cys/CySS is centered at approximately -80 mV in the plasma of healthy adults, and oxidation of E(h) Cys/CySS is implicated in inflammation associated with various diseases.The purpose of the present study was to determine whether oxidized E(h) Cys/CySS is a determinant of interleukin (IL)-1beta levels. Results showed a 1.7-fold increase in secreted pro-IL-1beta levels in U937 monocytes exposed to oxidized E(h) Cys/CySS (-46 mV), compared to controls exposed to a physiological E(h) of -80 mV (P<0.01). In LPS-challenged mice, preservation of plasma E(h) Cys/CySS from oxidation by dietary sulfur amino acid (SAA) supplementation, was associated with a 1.6-fold decrease in plasma IL-1beta compared to control mice fed an isonitrogenous SAA-adequate diet (P<0.01). Analysis of E(h) Cys/CySS and IL-1beta in human plasma revealed a significant positive association between oxidized E(h) Cys/CySS and IL-1beta after controlling for age, gender, and BMI (P<0.001).These data show that oxidized extracellular E(h) Cys/CySS is a determinant of IL-1beta levels, and suggest that strategies to preserve E(h) Cys/CySS may represent a means to control IL-1beta in inflammatory disease states
Reactivity of Biarylazacyclooctynones in Copper-Free Click Chemistry
The 1,3-dipolar cycloaddition of cyclooctynes with azides, also called "copper-free click chemistry", is a bioorthogonal reaction with widespread applications in biological discovery. The kinetics of this reaction are of paramount importance for studies of dynamic processes, particularly in living subjects. Here we performed a systematic analysis of the effects of strain and electronics on the reactivity of cyclooctynes with azides through both experimental measurements and computational studies using a density functional theory (DFT) distortion/interaction transition state model. In particular, we focused on biarylazacyclooctynone (BARAC) because it reacts with azides faster than any other reported cyclooctyne and its modular synthesis facilitated rapid access to analogues. We found that substituents on BARAC's aryl rings can alter the calculated transition state interaction energy of the cycloaddition through electronic effects or the calculated distortion energy through steric effects. Experimental data confirmed that electronic perturbation of BARAC's aryl rings has a modest effect on reaction rate, whereas steric hindrance in the transition state can significantly retard the reaction. Drawing on these results, we analyzed the relationship between alkyne bond angles, which we determined using X-ray crystallography, and reactivity, quantified by experimental second-order rate constants, for a range of cyclooctynes. Our results suggest a correlation between decreased alkyne bond angle and increased cyclooctyne reactivity. Finally, we obtained structural and computational data that revealed the relationship between the conformation of BARAC's central lactam and compound reactivity. Collectively, these results indicate that the distortion/interaction model combined with bond angle analysis will enable predictions of cyclooctyne reactivity and the rational design of new reagents for copper-free click chemistry
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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