Impacts of the Teach For America Investing in Innovation Scale-Up

In 2010, Teach For America (TFA) launched a major expansion effort, funded in part by a five-year Investing in Innovation (i3) scale-up grant of $50 million from the U.S. Department of Education. Using a rigorous random assignment design to examine the effectiveness of TFA elementary school teachers in the second year of the i3 scale-up, Mathematica Policy Research found that first- and second-year corps members recruited and trained during the scale-up were as effective as other teachers in the same high-poverty schools in both reading and math. To estimate the effectiveness of TFA teachers relative to the comparison teachers, we compared end-of-year test scores of students assigned to the TFA teachers and those assigned to the comparison teachers. Because students in the study were randomly assigned to teachers, we can attribute systematic differences in achievement at the end of the study school year to the relative effectiveness of TFA and comparison teachers, rather than to the types of students taught by these two different groups of teachers. In addition to the impact analysis described in this report, the evaluation included an implementation analysis that describes key features of TFA's program model and its implementation of the i3 scale-up

Assessing the Effectiveness of Teach For America's Investing in Innovation Scale-Up

In 2010, TFA launched a major expansion effort, funded in part by a five-year Investing in Innovation (i3) scale-up grant of $50 million from the U.S. Department of Education. By the 2012 -- 2013 school year -- the second year of the scale-up -- TFA had expanded its placements of first- and second-year corps members by 25 percent. This study examines the effectiveness of TFA elementary school teachers hired during the first two years of the i3 scale-up, relative to other teachers in the same grades and school

Farm-Level Impacts of Banning Growth- Promoting Antibiotic Use in U.S. Pig Grower/Finisher Operations

Antibiotics have been used by pig producers for several decades, and are now used routinely. This study documents the current productivity and economic impacts of the use of antibiotics for growth promotion (AGP) by pig grower/finishers at the farm level. We evaluate the impacts of an AGP ban, and use of AGP by all pig grower/finishers for 61S90 days (a more production-efficient level), using data from the National Animal Health Monitoring System Swine 2000 Survey. Findings indicate that pig productivity improves with AGP. Relative to current use, an AGP ban would decrease producer profits by $1,400 per 1,020-head barn, and profits would increase by$1,992 for each grower/finisher barn when AGP is fed for 61 to 90 days. There is increasing concern about the use of antibiotics in animal production, partly because of the selection for antibiotic resistance. Thus, a careful examination of the value of AGP in pork production is warranted.antibiotics, antimicrobial resistance, growth promotion, pigs, production, Agricultural and Food Policy, Health Economics and Policy, Livestock Production/Industries,

PRODUCER INCENTIVES FOR ANTIBIOTIC USE IN U.S. PORK PRODUCTION

Antibiotics have been used in animal production for several decades. Antibiotics are used routinely now in pork production (NAHMS 2002). There is increasing concern about the use of antibiotics in animal production. There is no hard evidence supporting the link of antibiotic use in animals to observations of antibiotic resistance infections in people. Nonetheless a careful examination of the value of continued antibiotic use in agricultural, and in pork production in particular is warranted. Therefore, the objective of our study is to validate the productivity and economic impacts of antibiotic use for pig producers at the farm level. We use data from the NAHMS 2000 swine survey. We estimate the combined affects from antibiotics used for growth promotion (AGP) and antibiotics used for disease prevention (ADP) on 4 productivity measures. We also estimate the economic impact of AGP and ADP for individual pig producers. We estimate these 4 productivity measures using seemingly unrelated regression analysis. We evaluate 4 scenarios which ban antibiotic use, and use a simple synthetic firm partial budget to estimate the economic consequences of these scenarios. We find that pig productivity is improved with AGP, but decreased with ADP. A total ban on AGP would cost pig producers $1,271 in lost profits per 1,020 head pig barn. A total ban on ADP however, would result in pig producers improving profits slightly. This occurs because productivity is negatively influenced by ADP. A ban of both AGP and ADP results in a small loss of producer profits ($376/1,020 head barn) because of the offsetting effects of ADP compared to AGP. Producers have higher profits when AGP and ADP are applied at levels where pig productivity is maximized. In this case, producers gain $4,146 for each 1,020 head barn compared to no antibiotic use.Livestock Production/Industries,

How much more can sunspots tell us about the solar dynamo?

Sunspot observations inspired solar dynamo theory and continue to do so. Simply counting them established the sunspot cycle and its period. Latitudinal distributions introduced the tough constraint that the source of sunspots moves equator-ward as the cycle progresses. Observations of Hale's polarity law mandated hemispheric asymmetry. How much more can sunspots tell us about the solar dynamo? We draw attention to a few outstanding questions raised by inherent sunspot properties. Namely, how to explain sunspot rotation rates, the incoherence of follower spots, the longitudinal spacing of sunspot groups, and brightness trends within a given sunspot cycle. After reviewing the first several topics, we then present new results on the brightness of sunspots in Cycle 24 as observed with the Helioseismic Magnetic Imager (HMI). We compare these results to the sunspot brightness observed in Cycle 23 with the Michelson Doppler Imager (MDI). Next, we compare the minimum intensities of five sunspots simultaneously observed by the Hinode Solar Optical Telescope Spectropolarimeter (SOT-SP) and HMI to verify that the minimum brightness of sunspot umbrae correlates well to the maximum field strength. We then examine 90 and 52 sunspots in the north and south hemisphere, respectively, from 2010 - 2012. Finally, we conclude that the average maximum field strengths of umbra 40 Carrington Rotations into Cycle 24 are 2690 Gauss, virtually indistinguishable from the 2660 Gauss value observed at a similar time in Cycle 23 with MDI

Interacting Dipoles from Matrix Formulation of Noncommutative Gauge Theories

We study the IR behavior of noncommutative gauge theory in the matrix formulation. We find that in this approach, the nature of the UV/IR mixing is easily understood, which allows us to perform a reliable calculation of the quantum effective action for the long wavelength modes of the noncommutative gauge field. At one loop, we find that our description is weakly coupled only in the supersymmetric theory. At two loops, we find non-trivial interaction terms suggestive of dipole degrees of freedom. These dipoles exhibit a channel duality reminiscent of string theory.Comment: LaTeX 11 pages, 4 figures; v.2 minor changes and some references added; v.3 many more technical details added and significantly different presentation, use REVTeX 4, to appear in PR