EFFECTS OF ALTERNATIVE FARM PROGRAMS AND LEVELS OF PRICE VARIABILITY ON TEXAS COTTON FARMS

This study examines the effects of alternative government farm programs and hypothetical price variability levels on two Texas cotton farms which were simulated stochastically over a 10-year period. Results indicate that a combination of high price variability and participation in government programs stimulates growth and wealth accumulation.Public Economics,

A Surrogate Model of Gravitational Waveforms from Numerical Relativity Simulations of Precessing Binary Black Hole Mergers

We present the first surrogate model for gravitational waveforms from the coalescence of precessing binary black holes. We call this surrogate model NRSur4d2s. Our methodology significantly extends recently introduced reduced-order and surrogate modeling techniques, and is capable of directly modeling numerical relativity waveforms without introducing phenomenological assumptions or approximations to general relativity. Motivated by GW150914, LIGO's first detection of gravitational waves from merging black holes, the model is built from a set of $276$ numerical relativity (NR) simulations with mass ratios $q \leq 2$, dimensionless spin magnitudes up to $0.8$, and the restriction that the initial spin of the smaller black hole lies along the axis of orbital angular momentum. It produces waveforms which begin $\sim 30$ gravitational wave cycles before merger and continue through ringdown, and which contain the effects of precession as well as all $\ell \in \{2, 3\}$ spin-weighted spherical-harmonic modes. We perform cross-validation studies to compare the model to NR waveforms \emph{not} used to build the model, and find a better agreement within the parameter range of the model than other, state-of-the-art precessing waveform models, with typical mismatches of $10^{-3}$. We also construct a frequency domain surrogate model (called NRSur4d2s_FDROM) which can be evaluated in $50\, \mathrm{ms}$ and is suitable for performing parameter estimation studies on gravitational wave detections similar to GW150914.Comment: 34 pages, 26 figure

Afrotheria genome; overestimation of genome size and distinct chromosome GC content revealed by flow karyotyping

AbstractAfrotheria genome size is reported to be over 50% larger than that of human, but we show that this is a gross overestimate. Although genome sequencing in Afrotheria is not complete, extensive homology with human has been revealed by chromosome painting. We provide new data on chromosome size and GC content in four Afrotherian species using flow karyotyping. Genome sizes are 4.13Gb in aardvark, 4.01Gb in African elephant, 3.69Gb in golden mole and 3.31Gb in manatee, whereas published results show a mean of 5.18Gb for Afrotheria. Genome GC content shows a negative correlation with size, indicating that this is due to differences in the amount of AT-rich sequences. Low genome GC content and small variance in chromosome GC content are characteristic of aardvark and elephant and may be associated with the high degree of conserved synteny, suggesting that these are features of the Afrotherian ancestral genome

Soybean Marketing Methods and Characteristics of Arkansas Grain Handlers

Arkansas producers should acquaint themselves with all marketing methods available to them. Of particular importance is the pervasiveness of price risk within the current economic climate. This bulletin provides insights into the current structure of the grain marketing industry, soybean handler characteristics, and the availability and use of marketing alternatives in Arkansas. Arkansas soybean handlers were surveyed in 1998 to determine the marketing practices of both handlers and producers for the 1996 crop year. Particular emphasis was placed on the types of contracting methods offered by these handlers. Both facility size and corporate structure were found to play a significant role in determining the types of marketing contracts offered as well as the frequency of usage by producers