How Does the Limited Base Acre Provision in the 2008 Farm Act Affect Small Farms?

Under the Food, Conservation, and Energy Act of 2008 (Farm Act), U.S. farms with 10 or fewer base acres became ineligible to receive Direct and Countercyclical Payment (DCP) or Average Crop Revenue Election (ACRE) program payments(Section 1101(d) and 1302(d)) from USDA. Limited resource and socially disadvantaged owners are exempt from this “base 10” provision. Eliminating payments on farms with 10 or fewer base acres reduces payments made by USDA Farm Service Agency (FSA) and the cost of administering the DCP and ACRE programs. We examine the characteristics of the farms affected by the limited base acre provision and answer the question: How does the provision affect small farms?US Farm Policy, Limited Base Acres Provision, 2008 Farm Act, Agricultural and Food Policy,

Chiral Symmetry and s-wave Low-Lying Meson-Baryon Resonances

The $s-$wave meson-baryon scattering is analyzed for the isospin-strangeness $I=1/2, S=0$ and $I=0,S=-1$ sectors, in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry. For both sectors, four channels have been considered: $\pi N$, $\eta N$, $K \Lambda$, $K \Sigma$ and $\pi \Sigma$, $\bar K N$, $\eta \Lambda$, $K \Xi$, respectively. The needed two particle irreducible matrix amplitudes are taken from lowest order Chiral Perturbation Theory in a relativistic formalism. There appear undetermined low energy constants, as a consequence of the renormalization of the amplitudes, which are obtained from fits to the available data: elastic $\pi N$ phase-shifts, $\pi^- p \to \eta n$ and $\pi^- p \to K^0 \Lambda$ cross sections and to $\pi\Sigma\to\pi\Sigma$ mass-spectrum, the elastic $\bar K N \to \bar K N$ and $\bar K N\to \pi \Sigma$ $t$--matrices and to the $K^- p \to \eta \Lambda$ cross section data. The position and residues of the complex poles in the second Riemann sheet of the scattering amplitude determine masses, widths and branching ratios of the $S_{11}-$ $N$(1535) and $-N$(1650) and $S_{01}-$ $\Lambda$(1405) and $-\Lambda$(1670) resonances, in reasonable agreement with experiment. A good overall description of data, from threshold up to around 2 GeV is achieved despite the fact that three-body channels have not been explicitly included.Comment: 5 Pages, 2 figures, invited contribution to Focus Session on Nature of Threshold N*, to be published in Proceedings of Nstar 2002, Pittsburgh, USA, October 9-12, 2002 (World Scientific

Renormalization of chiral two pion exchange NN interactions with delta excitations: correlations in the partial wave expansion

In this work we consider the renormalization of the chiral two-pion exchange potential with explicit delta-excitations for nucleon-nucleon scattering at next-to-leading (NLO) and next-to-next-to-leading order (N2LO). Due to the singular nature of the chiral potentials, correlations between different partial waves are generated. In particular we show that two-body scattering by a short distance power like singular attractive interaction can be renormalized in all partial waves with a single counterterm, provided the singularities are identical. A parallel statement holds in the presence of tensor interactions when the eigenpotentials in the coupled channel problem also coincide. While this construction reduces the total number of counterterms to eleven in the case of nucleon-nucleon scattering with chiral two-pion exchange interactions with delta degrees of freedom, the differences in the scattering phases as compared to the case with the uncorrelated partial wave renormalization become smaller as the angular momentum is increased in the elastic scattering region.Comment: 20 pages, 8 figures, a section has been added discussing cut-off dependence. Accepted for publication in PR

Polyakov loop in chiral quark models at finite temperature

We describe how the inclusion of the gluonic Polyakov loop incorporates large gauge invariance and drastically modifies finite temperature calculations in chiral quark models after color neutral states are singled out. This generates an effective theory of quarks and Polyakov loops as basic degrees of freedom. We find a strong suppression of finite temperature effects in hadronic observables triggered by approximate triality conservation (Polyakov cooling), so that while the center symmetry breaking is exponentially small with the constituent quark mass, chiral symmetry restoration is exponentially small with the pion mass. To illustrate the point we compute some low energy observables at finite temperature and show that the finite temperature corrections to the low energy coefficients are $N_c$ suppressed due to color average of the Polyakov loop. Our analysis also shows how the phenomenology of chiral quark models at finite temperature can be made compatible with the expectations of chiral perturbation theory. The implications for the simultaneous center symmetry breaking-chiral symmetry restoration phase transition are also discussed.Comment: 24 pages, 8 ps figures. Figure and appendix added. To appear in Physical Review

Chiral Lagrangian at finite temperature from the Polyakov-Chiral Quark Model

We analyze the consequences of the inclusion of the gluonic Polyakov loop in chiral quark models at finite temperature. Specifically, the low-energy effective chiral Lagrangian from two such quark models is computed. The tree level vacuum energy density, quark condensate, pion decay constant and Gasser-Leutwyler coefficients are found to acquire a temperature dependence. This dependence is, however, exponentially small for temperatures below the mass gap in the full unquenched calculation. The introduction of the Polyakov loop and its quantum fluctuations is essential to achieve this result and also the correct large $N_c$ counting for the thermal corrections. We find that new coefficients are introduced at ${\cal O}(p^4)$ to account for the Lorentz breaking at finite temperature. As a byproduct, we obtain the effective Lagrangian which describes the coupling of the Polyakov loop to the Goldstone bosons.Comment: 16 pages, no figure

Materiales silico-carbonosos en el Precámbrico de Sierra Morena

[Resumen] Se aborda, por primera vez, un estudio comparativo de las cuarcitas negras del Precámbrico de Sierra Morena, evidenciando su carácter de rocas sílico-carbonosas, asociadas a sucesiones con importantes aportes volcánicos y producidas por precipitaci6n química-bioquímica de sílice en medios marinos someros y restringidos. Se discute su distribuci6n, valor en la correlación es tratigráfica, evoluci6n textural con el aumento del metamorfismo y la deformación y algunos de los caracteres generales de su quimismo y mineralogíaAbstract] A comparative study of the black quarzites of the Precambrian of Sierra ~orena is atte~pted here for the 'first time, which reveals their character of silicacarbonaceous rocks related to succesion with important volcanic contributions and produced by chemical-biochemical precipitacion of silica in restricted and shallow marine environments. It is discussed their distribution value in .stratigraphical correlation, textural evolution with increasing rnetamorfism ando deformation, and sorne of the general character of its chemistry and mineralog

Evaluation of two protocols developed for Xanthomonas albilineas molecular detection in sugarcane

Leaf scald disease caused by Xanthomonas albilineans (Ashby) Dowson is one of the most devastating diseases of sugarcane which has a direct impact on production and manufacturing quality. Currently, molecular tests have been proposed for the detection of this phytopathogen. In this work, two PCR's protocols developed by Pan et al. in 1997 and 1999 were evaluated, with primers that amplify a fragment of the ITS region between the ribosomal genes 16S and 23S. The search of X. albilineans was done from the juice obtained of 35 asymptomatic and symptomatic plants of sugarcane cultivated in localities of the provinces of Misiones and Corrientes, Argentina. X. albilineans was detected in only one of the symptomatic samples but in any of the asymptomatic ones. The protocol developed in 1999 was the one that gave the best results. It is important to emphasize the detection of this phytopathogen in the province of Misiones.Fil: Arriola Benitez, Paula Constanza. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales. Departamento de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liotta, Domingo Javier. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales. Laboratorio de Biología Molecular Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Padovan, C.. Programa de Desarrollo de Áreas Rurales; ArgentinaFil: Quiroga, Marina Inés. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales. Departamento de Microbiología; Argentin

Fail-Safe Controller Architectures for Quadcopter with Motor Failures

A fail-safe algorithm in case of motor failure was developed, simulated, and tested. For practical fail-safe flight, the quadcopter may fly with only three or two opposing propellers. Altitude for two-propeller architecture was maintained by a PID controller that is independent from the inner and outer controllers. A PID controller on propeller force deviations from equilibrium was augmented to the inner controller of the three-propeller architecture. Both architectures used LQR for the inner attitude controller and a damped second order outer controller that zeroes the error along the horizontal coordinates. The restrictiveness, stability, robustness, and symmetry of these architectures were investigated with respect to their output limits, initial conditions, and controller frequencies. Although the three-propeller architecture allows for distribution of propeller forces, the two-propeller architecture is more efficient, robust, and stable. The two-propeller architecture is also robust to model uncertainties. It was shown that higher yaw rate leads to greater stability when operating in fail-safe mode.Comment: 7 pages, 9 figures, published in the 2020 6th International Conference on Control, Automation and Robotics (ICCAR) Proceeding