3,166 research outputs found
Economic Impacts of Regional Approaches to Rural Development: Initial Evidence on the Delta Regional Authority
This study assesses the initial economic outcomes of the Delta Regional Authority (DRA), which began funding rural development projects in the Mississippi Delta region in 2002. The study focuses on non-metropolitan DRA counties and similar counties elsewhere in the Mississippi Delta region and the southeast, using a quasi-experimental approach that combines matching methods, double and triple difference and switching regression estimation. We find that per capita income and transfer payments grew more rapidly in DRA counties than similar non-DRA counties, and that these impacts are larger in counties in which DRA spending was larger. Each additional dollar of DRA spending per capita is associated with an increase of 8 in earnings (primarily in the health care and social services sector) and $5 in transfer payments. The increase in transfer payments is mainly due to increased medical transfer payments. We also find that the number of hospital beds per capita increased more in counties where DRA spending per capita was greater. These findings suggest that investments supported by the DRA in improved medical facilities are promoting additional health sector earnings and medical transfer payments.rural economic development programs, economic impacts, Mississippi Delta, Delta Regional Authority, matching estimators, double difference, triple difference estimation, switching regression, Community/Rural/Urban Development, Research Methods/ Statistical Methods, R58, R11, O18, C21,
Greetings from the SOB Room
After a lapse of a year, the Seminar for the Older Brethren was restored for the Texas FiAAACEta, and was notable for breaking the sex barrier. Three women braved the Seminar for a couple of hours. Their presence changed the tone of the meeting which was probably a good thing
The Space Agent
Nothing has frightened me more through the years than the anticipatory commendation, as in my wife\u27s Will the rest of the house look as good as the side you painted last spring? Or as in Dr. Brice Ratchford\u27s July AAACE meeting comment, Editors tend to be audience conscious
Photos by J. C. Allen & Son
At the 1974 AAACE meeting in Indiana, 93-year-old John Allen showed up and took a bow
Operational benefits from the terminal configured vehicle
The NASA Terminal Configured Vehicle is a flying laboratory used to conduct research and development on improved airborne systems (including avionics) and operational flight procedures, with particular emphasis on utilization in the terminal area environment. The objectives of this technology development activity, focused on conventional transport aircraft, are to develop and demonstrate improvements which can lead to increased airport and runway capacity, increased air traffic controller productivity, energy efficient terminal area operations, reduced weather minima with safety, and reduced community noise by use of appropriate procedures. This paper discusses some early results of this activity in addition to defining present efforts and future research plans
Summary of a flight-test evaluation of the CL-84 tilt-wing V/STOL aircraft
Flight test evaluation of second generation CL-84 tilt-wing aircraft in hover, transition, and cruise mode
Laterally pumped GaAs/AlGaAs quantum wells as sources of broadband terahertz radiation
In this work we consider lateral current pumped GaAs/AlGaAs quantum wells as sources of incoherent terahertz radiation. The lateral field heats the electrons in a two-dimensional quantum layer and increases the population of higher subbands, hence also increasing the radiation power generated in spontaneous intersubband emission processes. Digitally graded quasi-parabolic and simple square quantum wells are considered, and the advantages of both types are discussed. Calculations at lattice temperatures of 77 K and 300 K, for electric fields up to 10 kV/cm, show that the optical output power of ~100−200 W/m2 may be achieved for the 7 THz source. The main peak of the spectrum, at 7 THz, of the quasi-parabolic quantum well exceeds the black body radiation at 300 K by approximately a factor of two and by two orders of magnitude at 77 K
The Other First Days of School: A Case Study of Two Teachers in an Urban School Setting
The first days of school are critical for many teachers across the country. They are often set aside to establish routines, expectations, the tone of the class, and begin developing the learning space for the year. As a result of high stakes accountability culture, many teachers revert to top-down management methods for establishing normative behaviors in their classes. This case study examines two mathematics teachers in an urban high school who approach their first days of school through alternative, democratic methods and learning spaces. Their examples include sharing ownership of their physical space, co-creating norms and building positive relationships with students, and providing students with opportunities to learn in ways that work best for them
Engineering tyrosine-based electron flow pathways in proteins: The case of aplysia myoglobin
Tyrosine residues can act as redox cofactors that provide an electron transfer ("hole-hopping") route that enhances the rate of ferryl heme iron reduction by externally added reductants, for example, ascorbate. Aplysia fasciata myoglobin, having no naturally occurring tyrosines but 15 phenylalanines that can be selectively mutated to tyrosine residues, provides an ideal protein with which to study such through-protein electron transfer pathways and ways to manipulate them. Two surface exposed phenylalanines that are close to the heme have been mutated to tyrosines (F42Y, F98Y). In both of these, the rate of ferryl heme reduction increased by up to 3 orders of magnitude. This result cannot be explained in terms of distance or redox potential change between donor and acceptor but indicates that tyrosines, by virtue of their ability to form radicals, act as redox cofactors in a new pathway. The mechanism is discussed in terms of the Marcus theory and the specific protonation/deprotonation states of the oxoferryl iron and tyrosine. Tyrosine radicals have been observed and quantified by EPR spectroscopy in both mutants, consistent with the proposed mechanism. The location of each radical is unambiguous and allows us to validate theoretical methods that assign radical location on the basis of EPR hyperfine structure. Mutation to tyrosine decreases the lipid peroxidase activity of this myoglobin in the presence of low concentrations of reductant, and the possibility of decreasing the intrinsic toxicity of hemoglobin by introduction of these pathways is discussed. © 2012 American Chemical Society
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Low prevalence of an acute phase response in asymptomatic children from a malaria-endemic area of Papua New Guinea
Levels of C-reactive protein (CRP), a classic marker for the acute phase response (APR), were measured in children with asymptomatic malaria infection in the Amele region of Papua New Guinea (PNG). Despite the presence of parasitemia, the prevalence of CRP levels consistent with an APR (CRP > 10 (xg/mL) was very low (< 10%). Splenomegaly was significantly associated with increased parasitemia (P < 0.001) and CRP levels (P < 0.001), highlighting the importance of splenomegaly as an indicator of recent high density infection in this population. Multivariate analysis showed that CRP levels were significantly associated with splenomegaly, fever, hemoglobin, and age (P < 0.002). CRP levels also increased with increasing parasitemia (P < 0.001) but remained < 3.5 (xg/mL. The low levels of CRP indicate that children in the Amele modulate inflammation associated with malaria
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