266 research outputs found

    Three Essays in Labor Economics with Applications to Sports

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    This dissertation research focuses on the intersection of labor and sports economics. All three chapters seek to answer or explore labor economics questions in the context of sports-related data.The first chapter addresses the substantial public debate regarding whether or not college athletes—specifically basketball and football players—should be compensated above the value of an athletic scholarship. In this paper, we estimate a panel data model with institution-level fixed effects and find that the annual value of a premium college basketball player at a major college program is approximately 380,000.Theseestimatesarelowerthanthosefoundinthepreviousliterature,whereyearlyvaluesoftenexceeded380,000. These estimates are lower than those found in the previous literature, where yearly values often exceeded 1 million. Furthermore, we find that yearly changes in winning percentage have no effect on revenue at major programs which limits the ability of non-premium players to significantly contribute to team revenue. The second chapter examines strategic bargaining which is an important tool used in business and employment settings. Participants in a bargaining situation can use a variety of strategies to maximize contract value. In this paper, we analyze the effect of delaying contractual agreement (or holding out) on NFL rookie contract values. Using an instrumental variables approach, we find that a player who delays agreement and signs a contract after the start of his team’s training camp receives an increase in total contract value of nearly 120,000,onaverage.Wealsofindthatthiseffectissubstantiallylargerforplayerswhoareselectedinearlyroundsofthedraftandsignlargercontracts,increasingtoanaverageeffectofaround120,000, on average. We also find that this effect is substantially larger for players who are selected in early rounds of the draft and sign larger contracts, increasing to an average effect of around 430,000 for first round draft picks.The third chapter studies the potential labor market impacts of sports teams and arenas. As professional sports continue to grow in popularity, the teams involved are competing for public funds in order to build the biggest and brightest stadiums and arenas. As this trend continues it is increasingly important to quantify the labor market impacts of sports teams and arenas to determine whether or not they are a sound public investment. This paperexpands on the current literature in two ways. First, by evaluating labor market effects at a narrower geographic level (by ZIP code), the data allow for a more precise examination of the potential for differing effects by proximity to the stadium/arena. Second, this paper deviates from the previous literature by estimating the impact of sports arenas that do not serve a major professional team, and instead focusing primarily on arenas that host minor league hockey teams in the AHL and ECHL. The results mirror the previous literature in that we fail to find any convincing evidence which supports the notion that construction of a new sports arena improves local labor market conditions

    Patient selection for partial breast irradiation by intraoperative radiation therapy: Can magnetic resonance imaging be useful?- perspective from radiation oncology point of view

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    The guidelines of the European and American Societies of Radiation Oncology (GEC-ESTRO and ASTRO) defined the selection criteria to offer partial breast irradiation (PBI) after lumpectomy in patients with low risk breast cancer regardless pre-operative staging. A recent publication by Tallet et al. explored the impact of preoperative magnetic resonance imaging (MRI) on patient eligibility for PBI. From their study, an ipsilateral BC was detected in 4% of patients, excluding these patients from intraoperative radiotherapy (IORT). The authors suggested that preoperative MRI should be used routinely for patient's candidate to IORT, because of the rate of ipsilateral breast cancer detected. In view of Tallet's article, we analyzed some aspects of this issue in order to envisage some possible perspective on how to better identify those patients who could benefit from PBI, especially using IORT. From historical studies, the risk of breast cancer recurrence outside index quadrant without irradiation is in the range of 1.5-3.5%. MRI sensitivity for detection of invasive cancer is reported up to 100%, and it is particularly useful in dense breast. Other imaging technique did not achieve the same sensibility and specificity as conventional MRI. Of note, none of randomized trials published and ongoing on PBI included preoperative MRI as part of staging. To perform a preoperative MRI in PBI setting is an interesting issue, but the available data suggest that this issue should be preferably studied in the setting of prospective clinical trials to clarify the role of MRI and the clinical meaning of the discovered additional foci. \ua9 Journal of Thoracic Disease

    Hydrophobic organization of membrane proteins

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    Membrane-exposed residues are more hydrophobic than buried interior residues in the transmembrane regions of the photosynthetic reaction center from Rhodobacter sphaeroides. This hydrophobic organization is opposite to that of water-soluble proteins. The relative polarities of interior and surface residues of membrane and water soluble proteins are not simply reversed, however. The hydrophobicities of interior residues of both membrane and water-soluble proteins are comparable, whereas the bilayer-exposed residues of membrane proteins are more hydrophobic than the interior residues, and the aqueous-exposed residues of water-soluble proteins are more hydrophilic than the interior residues. A method of sequence analysis is described, based on the periodicity of residue replacement in homologous sequences, that extends conclusions derived from the known atomic structure of the reaction center to the more extensive database of putative transmembrane helical sequences

    Gerentes Innovadoras Exitosas en Colombia.

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    Reconocer el papel de la mujer gerente desde el impacto generado a través de la gestión empresarial.En Colombia, hace no más de 80 años, la mujer era relegada únicamente para las labores del hogar, la concepción y crianza de los hijos; esta representaba los valores de la familia y dependía de ella ser la base de esta, solamente cuando faltaba el padre cabeza de familia la mujer tomaba las riendas del hogar y de los medios de generación de recursos del mismo. Pero con el paso de los años, las mujeres década tras década han demostraron sus capacidades en la gestión empresarial y hoy en día se puede observar el rol fundamental del desarrollo empresarial gracias a sus habilidades como la flexibilidad, la comunicación asertiva, la optimización de los recursos, innovación y sobre todo su capacidad de liderazgo, compromiso y persistencia. Es así como las organizaciones ahora optan por tener dentro de sus equipos directivos al menos una mujer para tener un grupo de trabajo sólido e integral. En Colombia, la realidad es que según La República, las juntas directivas están compuestas en 65% hombres y el restante 35% por mujeres; lo que evidencia que la brecha de ocupación y participación empresarial es un tema que perdura con el paso del tiempo, dado que solo hay un 11% de mujeres en cargos directivos en el país, lo que representa un porcentaje por menos de la mitad de algunos países de Europa que tienen hasta un 30%

    Análisis de estrategias y medidas de adaptación a la variabilidad climática en cultivos de café en Colombia.

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    El presente documento explora bajo una agenda internacional y nacional en materia de cambio climático, el escenario de vulnerabilidad del sector cafetero ante los fenómenos de variabilidad climática, “La Niña” y “El Niño”. Un sector clave para Colombia, si se tiene en cuenta que cerca de la mitad del aporte al Producto Interno Bruto (PIB) agrícola, proviene de la caficultura. Esta importancia del sector ante la agenda climática, puede valorarse además en el número de familias que se dedican a esta actividad, la mayoría representadas en pequeños productores que son altamente vulnerables, así como, empleos indirectos relacionados con la cadena de valor -comercialización, trilla, transporte, industrialización y exportación-, y costo de oportunidad de la caficultura, es decir, lo que el país perdería si desapareciera o se afectara esta actividad. Bajo este contexto, la adaptación se convierte en una prioridad y al mismo tiempo en un desafío para Colombia. Desde esta dimensión, este documento busca dar su aporte compilando el conjunto de estrategias y medidas institucionales, de asistencia técnica y financiera, que se han promovido en torno a la protección y gestión hacia un sector cafetero colombiano más resiliente al clima, a escalas nacional, regional y local. Lo anterior, para formular recomendaciones que contribuyan a la reducción de los riesgos y combinen objetivos de producción, conservación y adaptación de los sistemas para la toma de decisionesThis document explores under an international and national agenda on climate change, the scenario of vulnerability of the coffee sector to the phenomenon of climatic variability, of "La Niña" and "El Niño". A key sector for Colombia, considering that about half of the contribution to the agricultural gross domestic product (GDP) comes from coffee. This importance of the sector to the climate agenda can also be assessed in the number of families engaged in this activity, most of them represented in small producers who are highly vulnerable, as well as indirect jobs related to the value chain-marketing, threshing, transport, industrialization and export-, and opportunity cost of coffee, that is, what the country would lose if this activity disappeared or affected. In this context, adaptation becomes a priority and at the same time a challenge for Colombia. From this dimension, this document seeks to give its contribution by compiling the set of institutional strategies and measures, of technical and financial assistance, that have been promoted around the protection and management towards a Colombian coffee sector more resilient to the Climate, at national, regional and local scales. The foregoing, to formulate recommendations that contribute to the reduction of risks and combine objectives of production, conservation and adaptation of systems for decision-making

    Diseño e implementación de sistema de control de Nivel para tanques acoplados de almacenamiento de Hipoclorito

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    En la mejora de procesos industriales, es requerido disminuir tiempos de producción para que las empresas sean más competitivas. En la planta de producción se desarrolló el sistema de control, un operario supervisaba y controlaba el nivel de líquido de los tanques de almacenamiento de forma manual, por lo tanto, tenía un porcentaje alto de riesgo de sobrepasar los niveles y producir pérdidas económicas para la empresa. En este trabajo, se desarrolla el modelado del sistema actual con las condiciones de operación de la planta y se compara con los datos experimentales. Además se implementó el sistema de adquisición de datos, conexión de actuadores y sensores, además del diseño del algoritmo de control secuencial implementado en un controlador lógico programado, para realizar la supervisión y control del nivel de los tanques de almacenamiento de hipoclorito.Se describe la planta, la instalación de la instrumentación, el diseño de la interfaz gráfica y la programación del algoritmo de control en el PLC (Controlador Lógico Programable). Se obtiene una aproximación del modelo matemático respecto los datos experimentales siendo 0.43% para el tanque 1 y 0.86% para el tanqueIn the improvement of industrial processes, it is required to reduce production times for companies to be more competitive. In the clean product’s industry which was developed the control system, an operator supervised and controlled the liquid level of the storage tanks manually, therefore, had a high percentage of risk of exceeding the levels and produce economic losses for the company. In this work, the system of data acquisition, connection of actuators and sensors was implemented, as well as the design of the sequential control algorithm implemented in a programmer logic controller, to perform the monitoring and control of the level of the hypochlorite storage tanks. It describes the plant, the installation of the instrumentation, the design of the graphic interface and the programming of the control algorithm in the PLC (Programmable Logic Controller). The practical results obtained from the performance of the level control system of the coupled tank plant are shown.Universidad Libre de Colombia - Facultad de ingeniería - Ingeniería mecánic

    Gerentes Innovadoras Exitosas en Colombia.

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    Reconocer el papel de la mujer gerente desde el impacto generado a través de la gestión empresarial.En Colombia, hace no más de 80 años, la mujer era relegada únicamente para las labores del hogar, la concepción y crianza de los hijos; esta representaba los valores de la familia y dependía de ella ser la base de esta, solamente cuando faltaba el padre cabeza de familia la mujer tomaba las riendas del hogar y de los medios de generación de recursos del mismo. Pero con el paso de los años, las mujeres década tras década han demostraron sus capacidades en la gestión empresarial y hoy en día se puede observar el rol fundamental del desarrollo empresarial gracias a sus habilidades como la flexibilidad, la comunicación asertiva, la optimización de los recursos, innovación y sobre todo su capacidad de liderazgo, compromiso y persistencia. Es así como las organizaciones ahora optan por tener dentro de sus equipos directivos al menos una mujer para tener un grupo de trabajo sólido e integral. En Colombia, la realidad es que según La República, las juntas directivas están compuestas en 65% hombres y el restante 35% por mujeres; lo que evidencia que la brecha de ocupación y participación empresarial es un tema que perdura con el paso del tiempo, dado que solo hay un 11% de mujeres en cargos directivos en el país, lo que representa un porcentaje por menos de la mitad de algunos países de Europa que tienen hasta un 30%

    Intraoperative radiotherapy in gynaecological and genito-urinary malignancies: Focus on endometrial, cervical, renal, bladder and prostate cancers

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    Intraoperative radiotherapy (IORT) refers to the delivery of a single radiation dose to a limited volume of tissue during a surgical procedure. A literature review was performed to analyze the role of IORT in gynaecological and genito-urinary cancer including endometrial, cervical, renal, bladder and prostate cancers. Literature search was performed by Pubmed and Scopus, using the words "intraoperative radiotherapy/IORT", "gynaecological cancer", "uterine/endometrial cancer", "cervical/cervix cancer", "renal/kidney cancer", "bladder cancer" and "prostate cancer". Forty-seven articles were selected from the search databases, analyzed and briefly described. Literature data show that IORT has been used to optimize local control rate in genito-urinary tumours mainly in retrospective studies. The results suggest that IORT could be advantageous in the setting of locally advanced and recurrent disease although further prospective trials are needed to confirm this findings

    FDG-PET/CT imaging for staging and radiotherapy treatment planning of head and neck carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Positron emission tomography (PET) has a potential improvement for staging and radiation treatment planning of various tumor sites. We analyzed the use of <sup>18</sup>F-fluorodeoxyglucose (FDG)-PET/computed tomography (CT) images for staging and target volume delineation of patients with head and neck carcinoma candidates for radiotherapy.</p> <p>Methods</p> <p>Twenty-two patients candidates for primary radiotherapy, who did not receive any curative surgery, underwent both CT and PET/CT simulation. Gross Tumor Volume (GTV) was contoured on CT (CT-GTV), PET (PET-GTV), and PET/CT images (PET/CT-GTV). The resulting volumes were analyzed and compared.</p> <p>Results</p> <p>Based on PET/CT, changes in TNM categories and clinical stage occurred in 5/22 cases (22%). The difference between CT-GTV and PET-GTV was not statistically significant (p = 0.2) whereas the difference between the composite volume (PET/CT-GTV) and CT-GTV was statistically significant (p < 0.0001).</p> <p>Conclusion</p> <p>PET/CT fusion images could have a potential impact on both tumor staging and treatment planning.</p
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