An approach to facilitate problem solving: Individualizing the problem proposition

This paper addresses one of the many facets of the problem-solving activity: the challenge inherent in the problem proposition. We have identified the problem proposition as a core element in obtaining efficient problem solving. The Educational Dimension Portfolio, EDP, is our proposal for individualizing the problem proposition. This paper presents EDP's characteristics and implications through testing the results of 491 IESE Business School executives from the European Union (EU) and Latin America (LA). We enumerate five working hypotheses and show their results. We also propose an Educational Delivery Approach (EDA) to help managers become manager-educators. We present the Socratic educational process, the apprenticeship process and the providing alternatives process as a guide to become a manager-educator.problem solving; problem proposition; operations management; manager-educator;

Un recorrido necesario sobre los estudios de juventudes en Argentina

El presente artículo es de carácter teórico y busca reconstruir el abordaje que han tenido las juventudes en Nuestra América. El objetivo es obtener insumos para desarrollar una propuesta teórico-metodológica para el abordaje de las prácticas y los discursos que los y las jóvenes de sectores populares. El mismo parte desde los orígenes del concepto juventud, su desarrollo en las Ciencias Sociales y ofrece una clasificación de los estudios sectoriales sobre jóvenes en Argentina. Se presta especial atención a aquellos que abordan la relación de los y las jóvenes con la política, en sus distintos formatos y colores. Con el fin de marcar algunos trazos para el abordaje de las prácticas de los y las jóvenes.This article is a theoretical approach that wants explore inside the youth studies in Latin America. The goal is to get inputs to develop a proposal for theoretical and methodological approach to the practices and discourses of young people from working class.We analyze the origins of the concept ‘youth’, its development in Social Sciences and we make a classification of youth’s sectorial studies in Argentina. We take special attention to those that study the relationship between politics and youth. Finally, we show some elements to make youth studies.Fil: Seca, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentina. Universidad Nacional de Cuyo; Argentin

The Taxation of Capital and Labor Through the Self-Employment Tax

[Excerpt] Since 1950, self-employed individuals have been covered by the Social Security system. In many regards, their obligation to pay Self-Employment Contributions Act (SECA) taxes into the Old-Age, Survivors, and Disability Insurance (OASDI) and Hospital Insurance (HI) trust funds and their entitlement to Social Security and Medicare benefits parallel those of workers who are not self-employed and who thus are covered under the Federal Insurance Contributions Act (FICA). In both cases, the OASDI tax base is limited to income below a certain threshold, and the HI tax base is not constrained by any income ceiling. The two systems, however, diverge in an important way: The FICA tax is based solely on income from labor, but the SECA tax is based on net business income, which can also include income from capital. Such a difference in the tax code (say, among businesses providing the same goods and services) can prompt people to make choices that they would not otherwise make about self-employment or the organizational form of a business, thereby reducing the efficient allocation of resources. For this analysis, the Congressional Budget Office (CBO) decomposed the SECA tax bases for HI and OASDI into their labor and capital components, but the discussion focuses on the HI tax base because it is unconstrained by the income ceiling of the OASDI tax. CBO estimates that approximately 40 percent of the SECA-HI tax base (the amount of self-employment income subject to the HI tax) derives from capital, and the remainder derives from labor. Furthermore, more than half of the labor income of self-employed people—that is, the portion of their business income that would be subject to the FICA-HI tax if the business was incorporated instead of being a sole proprietorship or a partnership—is not included in the SECA-HI tax base. That occurs because when net income from all of a taxpayer’s businesses is less than the labor income from those businesses, the excess labor income is excluded from the SECA tax base. There is no similar exclusion from the FICA tax base. With both the taxed capital income and the excluded labor income accounted for, the total SECA-HI tax base is roughly three-quarters of the amount of income that would be taxable under the FICA-HI rules. Lawmakers could change the SECA tax base to try to align it more closely with the rules governing the FICA tax base. CBO analyzed three options for alignment that would modify the SECA tax base by either reducing the share of capital income or increasing the share of labor income included in that base. No option by itself would accomplish both of those objectives when applied to both sole proprietorships and partnerships, but one option would do so if applied only to partnerships. Two of the options would reduce the size of the SECA tax base—in one case by more than half—whereas the third option would increase the SECA tax base by a little

Mobility of the SecA 2-helix-finger is not essential for polypeptide translocation via the SecYEG complex

The bacterial ATPase SecA and protein channel complex SecYEG form the core of an essential protein translocation machinery. The nature of the conformational changes induced by each stage of the hydrolytic cycle of ATP and how they are coupled to protein translocation are not well understood. The structure of the SecA–SecYEG complex revealed a 2-helix-finger (2HF) of SecA in an ideal position to contact the substrate protein and push it through the membrane. Surprisingly, immobilization of this finger at the edge of the protein channel had no effect on translocation, whereas its imposition inside the channel blocked transport. This analysis resolves the stoichiometry of the active complex, demonstrating that after the initiation process translocation requires only one copy each of SecA and SecYEG. The results also have important implications on the mechanism of energy transduction and the power stroke driving transport. Evidently, the 2HF is not a highly mobile transducing element of polypeptide translocation

Design and control of parallel three phase voltage source Inverters in low voltage AC microgrid

Design and hierarchical control of three phase parallel Voltage Source Inverters are developed in this paper. The control scheme is based on synchronous reference frame and consists of primary and secondary control levels. The primary control consists of the droop control and the virtual output impedance loops. This control level is designed to share the active and reactive power correctly between the connected VSIs in order to avoid the undesired circulating current and overload of the connected VSIs. The secondary control is designed to clear the magnitude and the frequency deviations caused by the primary control. The control structure is validated through dynamics simulations.The obtained results demonstrate the effectiveness of the control structure

Four dimensions to induce learning: The challenge profile.

Knowledge generation is critical for company survival and managers need to face a new role: becoming educators. This requires an understanding of how knowledge is generated and what triggers individual learning. We propose that each individual has a personal predisposition to use a particular learning profile. Our findings show the Educational Dimensions Portfolio (EDP) as a gallery of profiles that match each individual's problem-solving challenge. A manager-educator can use the EDP model for triggering individual learning. We have verified, using statistical methods, that there are four EDP dimensions. They are related to both David Kolb's and Peter Honey's learning styles. We have verified that each individual has a personal predisposition to use a particular profile. We call it the challenge profile. That specific combination provides the individual's gateway not only to his own learning but also to inducing learning in others.manager as educator; innovation; challenge; learning styles; knowledge management;

Structure of the substrate-engaged SecA-SecY protein translocation machine.

The Sec61/SecY channel allows the translocation of many proteins across the eukaryotic endoplasmic reticulum membrane or the prokaryotic plasma membrane. In bacteria, most secretory proteins are transported post-translationally through the SecY channel by the SecA ATPase. How a polypeptide is moved through the SecA-SecY complex is poorly understood, as structural information is lacking. Here, we report an electron cryo-microscopy (cryo-EM) structure of a translocating SecA-SecY complex in a lipid environment. The translocating polypeptide chain can be traced through both SecA and SecY. In the captured transition state of ATP hydrolysis, SecAs two-helix finger is close to the polypeptide, while SecAs clamp interacts with the polypeptide in a sequence-independent manner by inducing a short β-strand. Taking into account previous biochemical and biophysical data, our structure is consistent with a model in which the two-helix finger and clamp cooperate during the ATPase cycle to move a polypeptide through the channel

Role of a Conserved Glutamate Residue in the \u3cem\u3eEscherichia coli\u3c/em\u3e SecA ATPase Mechanism

Escherichia coli SecA uses ATP to drive the transport of proteins across cell membranes. Glutamate 210 in the “DEVD” Walker B motif of the SecA ATP-binding site has been proposed as the catalytic base for ATP hydrolysis (Hunt, J. F., Weinkauf, S., Henry, L., Fak, J. J., McNicholas, P., Oliver, D. B., and Deisenhofer, J. (2002) Science 297, 2018–2026). Consistent with this hypothesis, we find that mutation of glutamate 210 to aspartate results in a 90-fold reduction of the ATP hydrolysis rate compared with wild type SecA, 0.3 s–1versus 27 s–1, respectively. SecA-E210D also releases ADP at a slower rate compared with wild type SecA, suggesting that in addition to serving as the catalytic base, glutamate 210 might aid turnover as well. Our results contradict an earlier report that proposed aspartate 133 as the catalytic base (Sato, K., Mori, H., Yoshida, M., and Mizushima, S. (1996) J. Biol. Chem. 271, 17439–17444). Re-evaluation of the SecA-D133N mutant used in that study confirms its loss of ATPase and membrane translocation activities, but surprisingly, the analogous SecA-D133A mutant retains full activity, revealing that this residue does not play a key role in catalysis