Are Canadian Farmers Overconfident?

wheat, marketing, overconfidence, Agribusiness, Institutional and Behavioral Economics, Marketing,

Phase transitions and crossovers in reaction-diffusion models with catalyst deactivation

The activity of catalytic materials is reduced during operation by several mechanisms, one of them being poisoning of catalytic sites by chemisorbed impurities or products. Here we study the effects of poisoning in two reaction-diffusion models in one-dimensional lattices with randomly distributed catalytic sites. Unimolecular and bimolecular single-species reactions are considered, without reactant input during the operation. The models show transitions between a phase with continuous decay of reactant concentration and a phase with asymptotic non-zero reactant concentration and complete poisoning of the catalyst. The transition boundary depends on the initial reactant and catalyst concentrations and on the poisoning probability. The critical system behaves as in the two-species annihilation reaction, with reactant concentration decaying as t^{-1/4} and the catalytic sites playing the role of the second species. In the unimolecular reaction, a significant crossover to the asymptotic scaling is observed even when one of those parameters is 10% far from criticality. Consequently, an effective power-law decay of concentration may persist up to long times and lead to an apparent change in the reaction kinetics. In the bimolecular single-species reaction, the critical scaling is followed by a two-dimensional rapid decay, thus two crossovers are found.Comment: 8 pages, 7 figure

Urban-regional administration in a globalizad scenery : new chalenges for its teaching

Se revisa la situación y el papel de los programas de formación de recursos humanos para la gestión del desarrollo urbano y regional de América Latina, a la luz de las transformaciones ocasionadas en las últimas décadas por los avances de la reestructuración productiva y la globalización. Con tal propósito considera su impacto sobre las condiciones que encuadran a este tipo de gestión, tratando de identificar sus principales efectos en la orientación, el contenido y la efectividad de dichos programas. En esa dirección analiza las implicancias de dichas transformaciones, tanto sobre el propio escenario de la acción social, como sobre las explicaciones teóricas sobre la generación del crecimiento económico, tratando de mostrar como ello altera las coordenadas básicas tanto de la gestión, como de los respectivos programas de formación urbano-regionales.In this lectura Dr. Carlos De Mattos checks the situation and the role of the human resources formation programmes for the administration of Latin America’s urban and regional development. He considers the impact that this reality has over administration, trying to identify its main effects on the orientation, content and the implemented programmes effectiveness. To the light of the changes caused in the last decades by the productive restructuring advances and the globalization, he analyzes these changes implications in the social action scenery, as well as over the theoretical explanations regarding economic growth generation, trying to show how it alters the basic coordinates of both the administration as much as the respective urban-regional formation programmes.Fil: De Mattos, Carlos A.

Características físicas, químicas e anatômicas das madeira de Araucaria angustifolia.

Organizado por Patrícia Póvoa de Mattos, Celso Garcia Auer, Paulo César Botosso e Rejane Stumpf Sberze

Características microbianas e degradação do pirazosulfuron-etil em um solo cultivado com arroz no sistema pré-germinado.

bitstream/item/30589/1/boletim-120.pd

Behavioral and cardiopulmonary effects of dexmedetomidine alone and in combination with butorphanol, methadone, morphine or tramadol in conscious sheep

Objective: To compare cardiopulmonary and sedative effects following administration of dexmedetomidine alone or with butorphanol, methadone, morphine or tramadol in healthy sheep. Study design: Randomized crossover study. Animals: Six Santa Inês sheep, five females, one male, aged 12–28 months and weighing 40.1 ± 6.2 kg. Methods: Sheep were assigned treatments of dexmedetomidine (0.005 mg kg−1; D); D and butorphanol (0.15 mg kg−1; DB); D and methadone (0.5 mg kg−1; DM); D and morphine (0.5 mg kg−1; DMO); or D and tramadol (5.0 mg kg−1; DT). All drugs were administered intravenously with at least 7 days between each treatment. Rectal temperature, heart rate (HR), respiratory rate (fR), invasive arterial pressure, blood gases and electrolytes were measured prior to administration of drugs (baseline, T0) and every 15 minutes following drug administration for 120 minutes (T15–T120). Sedation was scored by three observers blinded to treatment. Results: HR decreased in all treatments and fR decreased in DM at T30 and DMO at T30 and T45. PaCO2 was increased in D, DB and DM compared with baseline, and PaO2 decreased in D at T15 and T45; in DB at T15 to T75; in DM at T15 to T60; in DMO at T15; and in DT at T15, T30 and T75. There was a decrease in temperature in D, DB and DM. An increased pH was measured in D at all time points and in DT at T30–T120. inline image and base excess were increased in all treatments compared with baseline. There were no statistical differences in sedation scores. Conclusions and clinical relevance: The combination of dexmedetomidine with butorphanol, methadone, morphine or tramadol resulted in similar changes in cardiopulmonary function and did not improve sedation when compared with dexmedetomidine alone

Marketing Contracts, Overconfidence, and Timing in the Canadian Wheat Market

This paper investigates factors that impact marketing performance in the Canadian wheat market. Using data provided by the Canadian Wheat Board (CWB) for six crop years, results indicate that producers were not able to profitably use all marketing contracts offered by the CWB, earlier pricing tended to generate better performance, there was a negative relationship between activeness and performance (suggesting overconfidence in marketing skills), and performance was generally worse in volatile crop years. Further analysis reveals some of these findings differ when outperforming and underperforming producers are investigated separately, particularly with respect to activeness and volatility

Generation of nonclassical states of light via truncation of mixed states

A possible way of generating nonclassical states of light, especially non-Gaussian states, is via the truncation of a given state in the Fock basis. In recent work, we presented an alternative scheme for such quantum scissors [Phys. Rev. A 104, 033715 (2021)], employing a nondegenerate parametric amplifier, a beam splitter and photodetectors. An advantage of this setup is that it does not require the generation of Fock states beforehand, as in previous proposals. Here we extend this treatment to mixed input states. We show the possibilities of generating truncated states with either a maximum Fock number N or states having a minimum Fock number N. We discuss two specific examples of states to be truncated: i) the thermal state, and ii) the phase-diffused coherent state. In both cases, we show that the generated states can have significant sub-Poissonian statistics as well as non-Gaussian character. The degree of such nonclassical properties, as well as the success probabilities, can be changed by adjusting the parametric amplifier strength and the beam splitter transmittance.Comment: 13 pages, 11 figure