Yield Reserve Program Costs in the Virginia Coastal Plain

A proposed Yield Reserve Program designed to compensate farmers for any reduced yields resulting from nitrogen (N) application rates reduced to below recommended rates is evaluated. Assuming that farmers currently follow Extension recommendations for applying N, Yield Reserve Program participation reduces expected net revenue by $10 to$13/ha. The Yield Reserve Program reduces expected net revenue by $17 to$20/ha for farmers who apply N to maximize expected net revenue. Farmers’ costs of participation increase with lower probabilities of inadequate rainfall and higher corn prices and decline with higher N prices. The Yield Reserve Program can significantly reduce N applications to cropland, which may reduce N content of surface waters, but the costs to taxpayers and farmers will depend on how the program is implemented.compliance cost, nitrogen fertilizer, nonpoint source pollution, policy, yield response function, Agricultural and Food Policy, Crop Production/Industries,

Effects of Opportunistic Shooting on Trap Visitation by Wild Pigs

Wild pigs (Sus scrofa) are a non-native, invasive species that cause in excess of $1.5 billion of damage annually in the United States. Although lethal removal by trapping is oftentimes the most cost- and time-effective means for managing local wild pig populations, many landowners and natural resource professionals implement additional non-trapping techniques such as opportunistic daytime shooting, night shooting, hunting with dogs, and shooting over bait to further enhance removal rates. However, these non-trapping techniques may significantly alter the behavior of wild pigs and subsequently reduce trapping success. Our objective was to provide a preliminary assessment of the effects non-trapping techniques on wild pig visitation to traps. During the summer of 2012, we monitored trap visitation of wild pig sounders and boars using game cameras at 26 corral traps on 6 study sites in Alabama. We implemented combinations of non-trapping removal techniques (recreational stalk hunting, night shooting, and shooting of pigs at traps) coupled with increase vehicular (ATV and truck) traffic along property trails (hereafter collectively termed disturbance) for 3-5 days on 3 study sites while continually monitoring sounder and boar visitation to traps on all 6 study sites. On each site, we prebaited traps for ≥2 weeks to condition approximately 3-4 sounders to visit traps and used game cameras to determine sounder composition. Once sounders became conditioned to visiting traps daily, we recorded the total number of days traps were visited, number of visits per 24-hour period, and the duration (min) of all visits during a one-week period prior to the implementation of disturbance. Repeated trap visits were segregated by ≥ 1 hour absence of pigs between image recordings and visit duration began when the first pig of a sounder was recorded on camera until after the last pig of the sounder left the trap. After one week of monitoring visitation metrics, we applied disturbance to one of each pair of sites. We classified non-trapping removal techniques as either direct or indirect disturbance. Indirect disturbance was a combination of non-trapping removal techniques that were not knowingly applied directly to wild pigs, such as stalk hunting and the periodic discharge of firearms and cracker shells in the immediate vicinity of traps and increased vehicular traffic. Direct disturbances were applied directly to specific wild pigs, mainly the shooting of non-trapped pigs while they are at a trap which is somewhat of a common practice among novice pig control operators. To simulate this direct disturbance, we set several traps to capture a portion of pigs from a sounder. Once captured, we then released the pigs while discharging several rounds as the pigs exited the trap. After disturbance was implemented, we continued monitoring trap visitation metrics on both sites within each pair of study sites. We used a Before-AfterControl-Impact (BACI) design to test for interaction effects among the visitation metrics between treatment and control sites before and after disturbance implementation. We monitored trap visitation of 16 sounders and 8 boars and 10 sounders and 8 boars on treatment and control sites, respectively. Overall, we applied 39 hours of indirect disturbance and 3 hours of direct disturbance (via use of dogs) including the discharge of 112 cracker shells and 63 high-powered rifle rounds on treatment (disturbance) sites. Additionally, we simulated the shooting of pigs while at traps (direct disturbance) on an additional 6 sounders. Total number of days (P=0.349) and total number of visits (P=0.130) 1-week before and after disturbance on treatment and control sites were similar; however, total visit duration differed before and after disturbance on treatment and control sites (P=0.038), demonstrating a change in pig behavior in response to disturbance. Although we did not detect treatment effects for total days visited and total number of visits, we speculate this may be due to our relatively small sample sizes coupled with inherent variability in pig response. Moreover, we only applied disturbance for a relatively short period of time (3-5 days) with somewhat minimal levels of disturbance. Within the context of one year of data, we suggest non-trapping techniques be implemented cautiously, and strategically, when conducting wild pig removal as these techniques may reduce overall trapping success

How Do Bacteria Move Through Soil?

The contamination of water supplies by fecal bacteria is an important water quality issue in Kentucky. Contamination may come from point sources, such as straight pipes depositing raw sewage into streams, or nonpoint sources, such as manure runoff from cropland. A direct cost of contaminating water supplies is the expense that homesteads or water companies incur to chlorinate, filter, and otherwise treat water to make it potable. Indirect costs are the time lost to illness from drinking inadequately treated water, slower weight gain in livestock drinking contaminated water, and the degradation of aquatic habitats

Prospectus, May 28, 1979

HERE WE GO AGAIN: REGISTRATION HASSLES; Stugo takes action; \u27Chaos\u27 to highlight beginning of school; Commuter program will help Parkland people save gas; Stugo elections for ten seats is 12-13; Dedication features teleconferencing; Women to show defense; Computer majors eligible for ICP scholarship; Gammon on top of Comm. Dept.; Volunteers are wanted at UI; After registration, it can only get better; More music plays at PC; A quiz from abroad; Honor students total 46; IOC will meet next Tuesday; Dupe dept. is expanding; VA rules upheld in courts; ID rules listed; Slick can hurt Midwest; Parking regulations listed; Top 10 List from WPCD Radio; Athletic schedules: Golf Schedule -- 1979, Cross Country Schedule -- 1979, Women\u27s Volleyball Schedule -- 1979; Roueche suggests using videotapes of lectures; Pres. Staerkel greets students; PC lists job opportunities; Classified Advertising; Advertising Policy; Tickets are on sale on operas; New organization \u27flocks\u27 with others; Tenant Union plant sale will be held next weekend; Women\u27s b-ball to have meeting; Student organizations listed; Fast Freddy forecasts againhttps://spark.parkland.edu/prospectus_1979/1015/thumbnail.jp

Type II supernova spectral diversity, II: spectroscopic and photometric correlations

We present an analysis of observed trends and correlations between a large range of spectral and photometric parameters of more than 100 type II supernovae (SNe II), during the photospheric phase. We define a common epoch for all SNe of 50 days post-explosion, where the majority of the sample is likely to be under similar physical conditions. Several correlation matrices are produced to search for interesting trends between more than 30 distinct light-curve and spectral properties that characterize the diversity of SNe II. Overall, SNe with higher expansion velocities are brighter, have more rapidly declining light curves, shorter plateau durations, and higher 56Ni masses. Using a larger sample than previous studies, we argue that "Pd" - the plateau duration from the transition of the initial to "plateau" decline rates to the end of the "plateau" - is a better indicator of the hydrogen envelope mass than the traditionally used optically thick phase duration (OPTd: explosion epoch to end of plateau). This argument is supported by the fact that Pd also correlates with s 3, the light-curve decline rate at late times: lower Pd values correlate with larger s 3 decline rates. Large s 3 decline rates are likely related to lower envelope masses, which enables gamma-ray escape. We also find a significant anticorrelation between Pd and s 2 (the plateau decline rate), confirming the long standing hypothesis that faster declining SNe II (SNe IIL) are the result of explosions with lower hydrogen envelope masses and therefore have shorter Pd values.Fil: Gutiérrez, Claudia P.. Universidad de Chile; Chile. University of Southampton; Reino Unido. European Southern Observatory Santiago; Chile. Millennium Institute Of Astrophysics; ChileFil: Anderson, Joseph P.. European Southern Observatory Santiago; ChileFil: Hamuy, Mario. Millennium Institute Of Astrophysics; Chile. Universidad de Chile; ChileFil: González Gaitan, Santiago. Universidad de Chile; Chile. Universidade de Lisboa; Portugal. Millennium Institute Of Astrophysics; ChileFil: Galbany, Lluis. University of Pittsburgh at Johnstown; Estados Unidos. University of Pittsburgh; Estados UnidosFil: Dessart, Luc. Universidad de Chile; ChileFil: Stritzinger, Maximilian D.. University Aarhus; DinamarcaFil: Phillips, Mark M.. Las Campanas Observatory; ChileFil: Morrell, Nidia. Las Campanas Observatory; ChileFil: Folatelli, Gaston. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

Fixing the U-band photometry of Type Ia supernovae

We present previously unpublished photometry of supernovae 2003gs and 2003hv. Using spectroscopically-derived corrections to the U-band photometry, we reconcile U-band light curves made from imagery with the Cerro Tololo 0.9-m, 1.3-m and Las Campanas 1-m telescopes. Previously, such light curves showed a 0.4 mag spread at one month after maximum light. This gives us hope that a set of corrected ultraviolet light curves of nearby objects can contribute to the full utilization of rest frame U-band data of supernovae at redshift ~0.3 to 0.8. As pointed out recently by Kessler et al. in the context of the Sloan Digital Sky Survey supernova search, if we take the published U-band photometry of nearby Type Ia supernovae at face value, there is a 0.12 mag U-band anomaly in the distance moduli of higher redshift objects. This anomaly led the Sloan survey to eliminate from their analyses all photometry obtained in the rest frame U-band. The Supernova Legacy Survey eliminated observer frame U-band photometry, which is to say nearby objects observed in the U-band, but they used photometry of high redshift objects no matter in which band the photons were emitted.Comment: 25 pages, 9 figures, accepted for publication in the Astronomical Journa

Using Tactile Pressure Sensors to Measure Lateral Spreading Induced Earth Pressures Against a Large, Rigid Foundation

Two centrifuge tests were performed at the NEES facility at Rensselaer Polytechnic Institute (RPI) to observe lateral earth pressures mobilized against a rigid foundation element during liquefaction-induced lateral spreading, as part of a larger NEESR study aimed at developing novel approaches to mitigate the effects of seismically-induced ground failures on large, rigid foundation elements. Models were constructed in a laminar box to allow unimpeded downslope soil displacement, and the sand in the model was liquefied during the centrifuge test. Lateral pressures prior to, during, and after shaking and liquefaction were directly measured using a novel device: tactile pressure sensors. Prior to testing the production models, several 1g and centrifuge experiments were conducted to determine whether the tactile pressure sensors would accurately measure pressures. Using the tactile pressure sensor and configuration described in this paper, geostatic pressures measured prior to the shaking agreed well with the anticipated theoretical at-rest earth pressures. In this paper, we describe these initial tests, the challenges that were encountered, methods employed to overcome these challenges, and the production centrifuge tests

Saturation of intersubband transitions in p-doped GaAs/AlGaAs quantum wells

Optical saturation experiments have been performed on hh1-hh2 intersubband transitions in two samples of p-doped GaAs/AlGaAs quantum wells. The transitions had energies of 183 and 160 meV and the measured population relaxation times were 2±1.5 and 0.3±0.1 ps, respectively. Modeling of the quantum wells with a 6×6 k·p method shows that intersubband scattering by LO phonons can account for these relaxation times. The valence bandstructure is typically more complicated than the conduction bandstructure in a quantum well but these measurements show that LO phonons are the dominant intersubband scattering mechanism in both cases