Are Brazilian corn farmers overconfident about prices?

This paper aims to identify signs of overconfidence among corn producers in south and central-west Brazil. Over the period from October to November 2008, farmers were chosen to answer questions regarding their knowledge of futures markets and price expectations. A large part of subjects responded they do not trade futures contracts because they do not have enough information on the subject. The results show respondents were miscalibrated when estimating directly-stated and the indirectly-stated expected prices. In addition, for certain respondents, subjective variance for corn proves to be significantly less than the market variance. Finally, the paper concludes that the overconfidence effect can partially explain the low use of futures markets by Brazilian corn producers.overconfidence, subjective probability, probability elicitation, Institutional and Behavioral Economics,

VOWEL INSERTION IN THE SPEECH OF BRAZILIAN LEARNERS OF ENGLISH: A SOURCE OF UNINTELLIGIBILITY?

Abstract Abstract Abstract Abstract Abstract This article is an attempt to answer the following question: Is vowel insertion in the speech of Brazilian learners of English likely to be a source of unintelligibility? Insights to answer this question are provided on the basis of an analysis of empirical data derived from three studies which investigated the pronunciation intelligibility of Brazilian learners' English to three different groups of listeners. Samples containing words with vowel insertion, produced by Brazilian learners of English, were presented to three different groups of listeners who have the following three characteristics: (1) British listeners living in Birmingham, England, unfamiliar with the way Brazilians pronounce English words (1 st study); (2) British and American listeners living in Brazil, familiar with the way Brazilians pronounce English words (2 nd study); and (3) a second group of American and British listeners, also familiar with the Brazilian way of pronouncing English words (3 rd study). The listeners were asked to listen to the samples once, and to carry out tasks. In one of the tasks, they were required to write down what they had heard. The analysis focused on the 134 Neide Cesar Cruz listeners' orthographic transcriptions of the samples. On the basis of the results obtained, I argue that the category vowel insertion in itself is insufficient and too broad to provide an answer to such a question. Instead, I suggest that it is necessary to specify the type of vowel inserted, as well as the strength with which it is produced, when vowel insertion is considered in Brazilian learners' pronunciation intelligibility

Phenotypic variation through ontogeny: thyroid axis disruption during larval development in the frog pleurodema borellii

Studies of the effects of thyroid hormones on larval development in the frog Xenopus spp. have provided baseline information to identify developmental constraints and elucidate genetic and hormonal mechanisms driving development, growth, and life history transitions. However, this knowledge requires data based on other anurans to complete a comprehensive approach to the understanding of larval developmental diversity and phenotypic variation through ontogeny. Mesocosm experiments provide realistic data about environmental conditions and timing; this information is useful to describe anuran larval development and/or analyze endocrine disruption. In this study, mesocosm experiments of the larval development of the frog Pleurodema borellii were conducted to explore the consequences of thyroid axis disruption; the sensitivity of tadpoles to the methimazole (2.66 mg/l) and thyroxine (T4) (1.66 μg/l) was compared. These concentrations were selected based on previous studies in Pleurodema borellii. We test the effects of methimazole and thyroxine on development in early exposure (from beginning of larval development) and late exposure, 18 days after hatching, with doses administered every 48 h. Tadpoles were evaluated 31 days after hatching. Methimazole caused moderate hypertrophy of the thyroid gland, alteration in the growth rates, differentiation without inhibition of development, and an increase of developmental variability. Thyroxine produced slight atrophy of the thyroid gland, accelerated growth rates and differentiation, and minor developmental variability. In tadpoles at stages previous to metamorphose, skull development (differentiation of olfactory capsules, appearance of dermal bones, and cartilage remodeling) seemed to be unaltered by the disruptors. Moreover, similar abnormal morphogenesis converged in specimens under methimazole and thyroxine exposures. Abnormalities occurred in pelvic and pectoral girdles, and vent tube, and could have been originated at the time of differentiation of musculoskeletal tissues of girdles. Our results indicate that premetamorphic stages (Gosner Stages 25–35) are sensitive to minimal thyroid axis disruption, which produces changes in developmental rates; these stages would also be critical for appendicular musculoskeletal morphogenesis to achieve the optimal condition to start metamorphosis.Fil: Fabrezi, Marissa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Cruz, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentin

Properties of ultra-cool dwarfs with Gaia. An assessment of the accuracy for the temperature determination

We aimed to assess the accuracy of the Gaia teff and logg estimates as derived with current models and observations. We assessed the validity of several inference techniques for deriving the physical parameters of ultra-cool dwarf stars. We used synthetic spectra derived from ultra-cool dwarf models to construct (train) the regression models. We derived the intrinsic uncertainties of the best inference models and assessed their validity by comparing the estimated parameters with the values derived in the bibliography for a sample of ultra-cool dwarf stars observed from the ground. We estimated the total number of ultra-cool dwarfs per spectral subtype, and obtained values that can be summarised (in orders of magnitude) as 400000 objects in the M5-L0 range, 600 objects between L0 and L5, 30 objects between L5 and T0, and 10 objects between T0 and T8. A bright ultra-cool dwarf (with teff=2500 K and \logg=3.5 will be detected by Gaia out to approximately 220 pc, while for teff=1500 K (spectral type L5) and the same surface gravity, this maximum distance reduces to 10-20 pc. The RMSE of the prediction deduced from ground-based spectra of ultra-cool dwarfs simulated at the Gaia spectral range and resolution, and for a Gaia magnitude G=20 is 213 K and 266 K for the models based on k-nearest neighbours and Gaussian process regression, respectively. These are total errors in the sense that they include the internal and external errors, with the latter caused by the inability of the synthetic spectral models (used for the construction of the regression models) to exactly reproduce the observed spectra, and by the large uncertainties in the current calibrations of spectral types and effective temperatures.Comment: 18 pages, 17 figures, accepted by Astronomy & Astrophysic

Despidos ilegales en Colombia durante la pandemia del Covid 19 sobre trabajadores con estabilidad laboral reforzada

El presente artículo examina dos casos concretos, en los cuales tiene aplicación la Ley 361 de 1997, mediante la cual se precisan una serie componentes sociales hacia las personas con limitación y se dictan otras disposiciones junto con la defensa de los derechos catalogados como fundamentales dentro de la Constitución Política a fin de poder identificar las principales dificultades a las que se vieron sometidos aquellos trabajadores en estado de discapacidad o de debilidad manifiesta víctimas de despidos ilegales en nuestro país durante la pandemia del COVID 19 y con lo cual se afectó no solamente el bienestar propio de estos trabajadores, sino también su ambiente psicosocial, familiar y económico que se entrelaza alrededor de estas personas.UNIVERSIDAD LIBRE -- DERECHO -- ESPECIALIZACIÓN DERECHO LABORAL Y SEGURIDAD SOCIALThis article examines two specific cases, in which Law 361 of 1997 applies, which specifies a series of social components towards persons with disabilities and other provisions are issued along with the defense of the rights catalogued as fundamental within the Political Constitution in order to identify the main difficulties to which those workers in a state of disability or manifest weakness, victims of illegal dismissals in our country during the pandemic of COVID 19, were subjected and with which not only the welfare of these workers was affected, but also their psychosocial, family and economic environment that is intertwined around these people, but also their psychosocial, family and economic environment that is intertwined around these people

Developmental changes and novelties in ceratophryid frogs

The Neotropical frog genera Ceratophrys, Chacophrys and Lepidobatrachus form the monophyletic family Ceratophryidae. Although in- and out-group relationships are not fully resolved, the monophyly of the three genera is well supported by both morphological and molecular data. Much is known about the morphology of the ceratophryids, but there is little comparative information on how modification of a common ancestral developmental pathway played a role in shaping their particular body plans. Herein, we review morphological variation during ceratophryid ontogeny in order to explore the role of development in their evolution. The ceratophryids are collectively characterized by rapid larval development with respect to other anurans, yet the three genera differ in their postmetamorphic growth rates to sexual maturity. Derived traits in the group can be divided into many homoplastic features that evolved in parallel with those of anurans with fossorial/burrowing behaviors in semiarid environments, and apomorphies. Morphological novelties have evolved in their feeding mechanism, which makes them capable of feeding on exceptional large prey. Lepidobatrachus is unusual in having reduced the ecomorphological differences between its larvae and adults. As a result, both the larvae and the frog are similarly able to capture large prey underwater. Some unique features in Lepidobatrachus are differentiated in the tadpole and then exaggerated in the adult (e.g., the posterior displaced jaw articulation) in a manner unobserved in any other anurans.Fil: Fabrezi, Marissa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Quinzio, Silvia Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Goldberg, Francisco Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Cruz, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Chuliver Pereyra, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Wassersug, Richard J.. Dalhousie University Halifax; Canad

Coenzyme q10 microparticles formation with supercritical carbon dioxide

Coenzyme Q10 is a powerful antioxidant used on cardiovascular, neurodegenerative and cancer diseases. Its hydrophobic nature do limit its applications, because human body absorbs it with dfculty, that is why it was proposed to increase its bioavailability by diminishing the particle size using supercritical carbon dioxide. It was determined experimentally the phase behavior of the coenzyme in a supercritical system. The equilibrium data and a factorial 2k experimental design were utilized to find how the shape and size of the microparticles are affected by temperature, coQ10 concentration and nozzle diameter. Microparticles were characterized using infrared spectrometry and chromatography. For verify the fundamental chemical structure, the size and the shape of the microparticles was used scanning electronic microscopy. It was found a significant decrease in particle size and a modification of physical structure. The antioxidant power of coQ10 after micronization was measured, showing an increase of this property. Finally, in order to evaluate the bioavailability, the kinetic of solubility was determined in ethanol, having a substantial increase on solubilization speed of micronized coQ10 compared with the commercial one

Propuesta de mejora en las áreas de producción y logística para incrementar la rentabilidad de la empresa productora de calzado "Inversiones Industriales del Amazonas S. A. C.", 2017

El autor no autorizó la publicación de la tesis

Registro, Aplicación y Pago del Impuesto Sobre la Renta (IR) en la Empresa Agropecuaria La Laguna S.A., Municipio, Matagalpa, Departamento Matagalpa, en el Periodo 2015

La presente investigación está enfocada en el registro aplicación y pago del Impuesto sobre la Renta (IR) en las empresas de los Departamentos de Matagalpa, Managua, y Jinotega en el periodo 2015. Tiene como propósito analizar el registro aplicación y pago del impuesto sobre la renta en las empresa agropecuaria La Laguna,S.A Municipio, Matagalpa, Departamento Matagalpa, en el año 2015. El presente trabajo es muy importante para la empresa La Laguna, S.A ya que le permite identificar debilidades asimismo fortalecer sus operaciones tanto en el registro aplicación y pago del impuesto sobre la renta, evitándose a si multas y sanciones por una mala aplicación u omisión de dicho impuesto. . Se identificó en la empresa La Laguna,S.A el registro aplicación y pago del impuesto sobre la renta (IR), también determinamos la importancia de la aplicación y pago de dicho impuesto y valoramos al momento de la aplicación del instrumento (entrevista) que la empresa no presenta debilidades en el registro aplicación y pago de impuesto ya que es una empresa que realiza sus ventas a través de la bolsa agropecuaria, la cual declara y paga sus impuestos por compra de bienes y servicios en generales así como retenciones definitivas por ventas de caf

Migración de retorno de Estados Unidos a los municipios metropolitanos del Estado de México 2000-2010

Análisis de las condiciones sociodemográficas de los migrantes retornados a México entre 2000 y 2010.La migración de mexicanos hacia otros países, principalmente a Estados Unidos de Norteamérica, es un fenómeno que ha sido estudiado desde diversos enfoques y metodologías. Uno de las dimensiones del sistema migratorio que mayor atención se ha dado desde 2008 a la fecha es el asociado a la migración de retorno, y llama la atención que los flujos de retorno se han modificado en su dinámica e intensidad, particularmente los que tienen como destino los conglomerados urbanos. Por ello, el presente estudio tiene como objeto analizar, a través de técnicas estadísticas descriptivas y de correlación de variables, las relaciones principales de la migración de retorno en los municipios metropolitanos vs los no metropolitanos del Estado de México con la intensidad migratoria, la marginación y la pobreza; así como describir las características sociodemográficas de quienes retornaron a la entidad diferenciados entre lo metropolitano y no metropolitano para con ello aportar elementos para la definición de estrategias de política públicaCentro de Investigación y Estudios Avanzados de la Población UAEMé