The Profitability Of The U.S. Food Supply Chain: Financial Indicators, Cross-Section And Time-Series Effects

This study examines the U.S. agribusiness’ profitability from 1986 to 2008. By using regression analysis, we model accounting returns as a function of diverse financial indicators. To select the explanatory variables we further decompose the DuPont equation and perform some ad hoc transformations to model return on investment (rather than return on equity). In addition, using a two-way fixed effects model, we test within sectors and time effects of returns. We compare time effects with the three most recent economic recessions

Thorium and uranium isotopes in a manganese nodule from the Peru basin determined by alpha spectrometry and thermal ionization mass spectrometry (TIMS): Are manganese supply and growth related to climate?

Thorium- and uranium isotopes were measured in a diagenetic manganese nodule from the Peru basin applying alpha- and thermal ionization mass spectrometry (TIMS). Alpha-counting of 62 samples was carried out with a depth resolution of 0.4 mm to gain a high-resolution230Thexcess profile. In addition, 17 samples were measured with TIMS to obtain precise isotope concentrations and isotope ratios. We got values of 0.06–0.59 ppb (230Th), 0.43–1.40 ppm (232Th), 0.09–0.49 ppb (234U) and 1.66–8.24 ppm (238U). The uranium activity ratio in the uppermost samples (1–6 mm) and in two further sections in the nodule at 12.5±1.0 mm and 27.3–33.5 mm comes close to the present ocean water value of 1.144±0.004. In two other sections of the nodule, this ratio is significantly higher, probably reflecting incorporation of diagenetic uranium. The upper 25 mm section of the Mn nodule shows a relatively smooth exponential decrease in the230Thexcess concentration (TIMS). The slope of the best fit yields a growth rate of 110 mm/Ma up to 24.5 mm depth. The section from 25 to 30.3 mm depth shows constant230Thexcess concentrations probably due to growth rates even faster than those in the top section of the nodule. From 33 to 50 mm depth, the growth rate is approximately 60 mm/Ma. Two layers in the nodule with distinct laminations (11–15 and 28–33 mm depth) probably formed during the transition from isotopic stage 8 to 7 and in stage 5e, respectively. The Mn/Fe ratio shows higher values during interglacials 5 and 7, and lower ones during glacials 4 and 6. A comparison of our data with data from adjacent sediment cores suggests (a) a variable supply of hydrothermal Mn to sediments and Mn nodules of the Peru basin or (b) suboxic conditions at the water sediment interface during periods with lower Mn/Fe ratios

The portafolio as an instrument for evaluating a teaching training programme

Este trabajo presenta los resultados de un estudio que utilizó el portafolio como instrumento para la evaluación de profesores que participaron en un programa de formación docente en el sureste de México. Los resultados del estudio indican que la metodología utilizada fue valiosa para evaluar el desempeño de los docentes e identificar áreas de mejora. La investigación es parte del proyecto Modelo para el desarrollo y evaluación de competencias académicas de la Red de Desarrollo y Evaluación de Competencias Académicas (PROMEP).Este trabalho apresenta os resultados de um estudo que usado o portfólio como uma ferramenta para a avaliação de professores que participou de um programa de formação de professores de Sudeste do México. Os resultados do estudo indicam que a metodologia foi valiosa para avaliar o desempenho dos professores e identificar áreas para melhoria. A pesquisa é parte do projeto modelo para o desenvolvimento e a avaliação das competências académicas da rede de desenvolvimento e avaliação das competências académicas (PROMEP).This paper presents the findings of a study that used a teacher portfolio as instrument for evaluating faculty members who participated in a preparation program in Southeast Mexico. Findings of the study indicate that portfolios were valuable both for evaluation and for improvement purposes. The study is part of a larger research endeavor: Model fro the development and assessment of academic competencies developed by the Red de Desarrollo y Evaluación de Competencias Académicas (PROMEP)

The relationship between accruals, earnings, and cash flows: evidence from latin america

The relationships between earnings, accruals, and cash flows for selected Latin American countries (Mexico, Chile, and Argentina) are investigated in this study from 1990 to 2009. We find a negative relationship between accruals and cash flow across decile portfolios. More importantly, firms reporting the highest level of accruals, have the worst level of cash flows, but not the worst level of earnings. This relationship is of economic importance given that investors are very oriented towards firms yielding high earnings and might fail to realize that earnings are not always accompanied by strong levels of cash flows. Results are disaggregated by years and countries, and compared to previous results for U.S. firms.ITESO, A.C.UPSoutheastern Louisiana UniversityUniversity of Florid

Accruals for latin american firms

The relationships among earnings, accruals, and cash flows for selected Latin American countries (Mexico, Chile, and Argentina) are investigated in this study from 1990 to 2009. We find a negative relationship between accruals and cash flow across decile portfolios. More importantly, firms in decile portfolio 10 reporting relative high level of earnings relative to assets, 6.5%, have the worst level of cash flows (negative 9.7%). Results are compared to previous results for U.S. firms. Given the level of sophistication of these capital markets, results for Latin American firms are less stable than for the U.S.Results disaggregated by years show that high-accruals portfolios consistently report relative high levels of earnings but low levels of cash flow. Further, the gap between earnings and cash flow is higher after 2000. This relationship is of economic importance given that investors are very oriented towards firms yielding high earnings and might fail to realize that earnings are not always accompanied by strong levels of cash flows.ITESO, A.C.UPSoutheastern Louisiana UniversityUniversity of Florid

Métaheuristiques pour la classification de bouchons naturels en liège

We study heuristic methods for a classification problem encountered in cork industry. More precisely, we want to optimize the parameters of the classification rule that is daily used to classify corks. We experimented several metaheuristics and compared their performance on a real test case. The obtained results improve the current classification rate. We propose also, from our observations, new directions that may lead to further improvement for a still better classification.

Developing ICT Skills of STEM Teachers in Mexico: The Key Role of the Tutorial Function

It is well documented in distance education literature that one of the factors that are considered essential to the success of an online course is the tutorial function. The role of counselor consists of assisting and encouraging students, building learning activities, and developing support strategies for the use of technology. The tutor thus was assessed as one element of great importance in on-line education, and, to some, an essential feature of this mode. In this paper, the importance of the tutorial function and its effect on the development of skills for using information and communication technology (ICT) in science, technology, engineering and mathematics (STEM) teachers was analyzed. The results showed that on average the treatment contributed to improving the skills of teachers, as 100% of those analyzed for competence increased their scores. Interpolation lines were used for three domains, and demonstrated the effectiveness of the tutor function. The implications of this work are discussed in the context of the National Development Plan of Mexico (2003-2018), and more specifically, under the recommendations of the inclusion of ICT competency standards for teachers of UNESCO

The Gould's Belt Very Large Array Survey III. The Orion region

We present results from a high-sensitivity (60 $\mu$Jy), large-scale (2.26 square degree) survey obtained with the Karl G. Jansky Very Large Array as part of the Gould's Belt Survey program. We detected 374 and 354 sources at 4.5 and 7.5 GHz, respectively. Of these, 148 are associated with previously known Young Stellar Objects (YSOs). Another 86 sources previously unclassified at either optical or infrared wavelengths exhibit radio properties that are consistent with those of young stars. The overall properties of our sources at radio wavelengths such as their variability and radio to X-ray luminosity relation are consistent with previous results from the Gould's Belt Survey. Our detections provide target lists for followup VLBA radio observations to determine their distances as YSOs are located in regions of high nebulosity and extinction, making it difficult to measure optical parallaxes.Comment: Accepted for publication in ApJ; 51 pages, 15 figures, 5 table