The quest for corporate growth

Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1996.Includes bibliographical references (leaves 116-122).by Gabriel D. Obrador Ramos and Edmundo E. Ruiz Rodriguez.M.S

Cómo lograr longevidad con calidad de vida. Caso sector lácteos 2000-2009

En la primera década del siglo XXI, las empresas colombianas se han visto afectadas por discontinuidades de tipo tecnológico, político, demográfi co, económico que han puesto a prueba su capacidad de aprendizaje para ajustarse a dichas difi cultades y poder sobrevivir. Estas discontinuidades presentes en el entorno han generado una turbulencia en el sector de lácteos; fenómeno caracterizado por tres elementos: incertidumbre, dinamismo y complejidad. La incertidumbre se hace evidente al momento de tomar decisiones, sin lograr tener certeza sobre lo que puede pasarle a la empresa o sobre el efec to de una decisión que se tome; el dinamismo se logra observar por el cam bio per manente en las necesidades de los clientes y el surgimiento de nuevos productos, que origina incremento de la rivalidad por precio; y la complejidad puede identifi carse en el surgimiento de otros actores con los que se debe interactuar para llevar a cabo una transacción

Evaluación del desempeño de un hormigón con incorporación de vidrio reciclado finamente molido en reemplazo de cemento mediante ensayos de laboratorio

La producción de desechos en las grandes ciudades es un problema que ha conducido a la realización de una serie de estudios tendientes al aprovechamiento de los residuos. Entre los residuos urbanos más comunes se encuentra el vidrio. Este material puede reciclarse para la fabricación de nuevos envases y vajilla aunque la dificultad para transportar el vidrio de desecho desde el sitio donde se genera hacia las cristalerías que lo reciclan sugiere la posibilidad de buscar disposiciones alternativas para este material. Una de estas alternativas es integrarlo a algún proceso productivo como la fabricación de hormigón en reemplazo parcial del cemento de la mezcla.En el presente trabajo se analizó cómo afecta la incorporación de vidrio de desecho finamente molido la resistencia del hormigón y la reacción álcali-sílice de la mezcla. Siguiendo los estudios disponibles en la literatura se llevaron a cabo mezclas con distintos porcentajes de reemplazo de cemento. Los primeros resultados de este estudio, que aún se encuentra en ejecución, indican que el vidrio molido, en el tamaño utilizado, se comporta como una puzolana. Aunque el reemplazo de parte del cemento en la mezcla reduce su resistencia en edades tempranas, en comparación con mezclas sin vidrio, su resistencia es mayor a las esperadas para mezclas con igual contenido de cemento. Se encontró además que el vidrio inhibe significativamente la reacción álcali sílice, aún cuando se utilizan áridos reactivos y que la reducción de resistencia referida anteriormente no es significativa para edades avanzadas

Standardized age - Length key for east Atlantic and Mediterranean bluefin tuna based on otoliths readings.

This paper presents an age-length key (ALK) based on age estimates from otoliths following a recent standardized reading criterion. Sampling of Atlantic bluefin tuna (Thunnus thynnus) otoliths comes from the “Biological and genetic sampling and analysis" (GBYP) project and was complemented with some samples from the Spanish institute of Oceanography. Using 2010 to 2012 data improves length range and monthly sampling coverage. Variability in length at age from ALK seems acceptable and although it was developed from data pooled over three years, the bias is likely to be small. Final age was adjusted to account for the date of capture and the timing of bands formation throughout the year. Monthly formation of edge type, translucent or opaque, was inconclusive and did not allow establishing an annual formation pattern. The confidence interval of the von Bertalanffy growth model curve fitted to ALK data included currently adopted growth function for eastern bluefin stock and western stock function up to age 8. From age 9, this last western function predicts slightly older ages than the present ALK growth model.Postprint0,000

Age-length keys availability for Atlantic bluefin tuna captured in the eastern management area

This paper analyzes the available direct ageing information in the last decade from Atlantic bluefin tuna caught in the eastern management area. To investigate differences among ALKs, a standard Von Bertalanffy growth function (VB) was fit to length at age data for each stratum. A deficient convergence of VB fitting to the asymptotic length due to the scarcity of old specimens was found for all available ALKs. After these analyses some records were identified as outliers (reading methodological issues) and removed from the data base.En prensa0,000

How do galaxies populate haloes in high-density environments? An analysis of the Halo Occupation Distribution in future virialized structures

There are hints suggesting that properties of galaxy populations in dark matter haloes may depend on their large-scale environment. Recent works point out that very low-density environments influence halo occupation distribution (HOD), however there is not a similar analysis focused on high-density environments. Here we use a simulated set of future virialized superstructures (FVS) to analyse the occupation of galaxies in haloes within these high globally dense regions. We use a publicly available simulated galaxy set constructed with a semi-analytical model to identify FVS in the simulation. Then, we computed the HOD within these superstructures for different absolute magnitude thresholds and make several analysis including the comparison to the global HOD results. We study the dependence on the results on properties of the FVS such as density and volume as well as consider the morphology of galaxies. We also analysed the properties of the stellar content of galaxies and the formation time of the haloes inside FVS. We find a significant increase in the HOD inside FVS. This result is present for all absolute magnitude thresholds explored. The effect is larger in the densest regions of FVS, but does not depend on the volume of the superstructure. We also find that the stellar-mass content of galaxies considerably differs inside the superstructures. Low mass haloes have their central and satellite galaxies with a higher stellar mass content (50%), and exhibit mean star ages (20%) older than average. For massive haloes in FVS we find that only the stellar mass of satellite galaxies varies considerably corresponding to a decrease of 50%. We find a significant statistical difference between the formation times of haloes in FVS and the average population. Haloes residing in superstructures formed earlier, a fact that leads to several changes in the HOD and their member galaxy properties.Comment: 12 pages, 14 figures, the paper has been accepted to be published by the A&

Antiagregación y anticoagulación en síndromes coronarios agudos: niveles de evidencia

Management of acute coronary syndromes (ACS) has moved rapidly in parallel with our understanding of the pathophysiological basis of the disease. In the eighties, the demonstration of the pivotal role of coronary thrombosis in the etiology of a ACS led to administration of aspirin and unfractionated heparin. In recent years, new medical and invasive therapies have been developed: anti-platelets (thienopyridines and glycoprotein Ilb/IlIa inhibitors), antithrombins (low molecularweight heparins) and most recently, factor Xa inhibitors (pentasaccharides). As new treatments are rapidly added, clinicians are constantly challenged to incorporate new information and guidelines into their practices in a timely fashion

Update on indications, complications, and outcomes of scleral contact lenses

Background: The role of scleral contact lenses (SCLs) has increasingly expanded since the first lens was fitted more than a century ago. While it was initially prescribed for the management of severely compromised corneas, the indications for modern SCL use have expanded to include less severe diseases. In this review, we aimed to provide an up-to-date overview of the current indications, complications, and outcomes for the various types of SCLs. Methods: In this narrative review, we thoroughly searched the PubMed/MEDLINE database for literature published from January 1980 to November 2021. Only relevant up-to-date English references were included. Furthermore, the figures in this manuscript were derived from our unit’s patient documentation. Results: Currently, SCLs can successfully be used to manage ocular surface diseases, visually rehabilitate irregular corneas, and correct irregular refractive errors. Although newer materials have yielded the same visual outcomes with fewer complications, these consequences still occur in approximately one-third of contact lens wearers, including difficulties in insertion and/or removal, discomfort or pain, and developing either halos, blurriness, or haze. Even though most of these complications are minor and can be easily treated, a good practice is essential to avoid sight-threatening complications such as microbial keratitis. Conclusions: SCLs are indispensable in ophthalmic clinics. The development of better-quality SCLs has increased the number of indications and improved the achievable visual rehabilitation. The future of developing improvements in SCL design, materials, and fit, and the expansion of their indication range is promising

Diagnóstico y tratamiento de la trombosis venosa profunda

Deep-vein thrombosis (DVT) is a common condition that can lead to complications such as postphlebitic syndrome, pulmonary embolism and death. Currently, an algorithm strategy combining pretest probability, D-dimer testing and compression ultrasonography imaging allows for safe and convenient estimation of suspected lower-limb thrombosis. The mainstay of treatment is anticoagulation therapy. The use of low-molecular-weight heparin or pentasaccharide (fondaparinux) allows for outpatient management of most patients with DVT. The duration of anticoagulation depends on whether the primary event was idiopathic or secondary to a transient risk factor. Interventions such as thrombolysis and placement of inferior vena cava filter are reserved for special situations

Fossil Groups Origins III. Characterization of the sample and observational properties of fossil systems

(Abridged) Fossil systems are group- or cluster-sized objects whose luminosity is dominated by a very massive central galaxy. In the current cold dark matter scenario, these objects formed hierarchically at an early epoch of the Universe and then slowly evolved until present day. That is the reason why they are called {\it fossils}. We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical properties. Deep $r-$band images were taken for each candidate and optical spectroscopic observations were obtained for $\sim$ 1200 galaxies. This new dataset was completed with SDSS DR7 archival data to obtain robust cluster membership and global properties of each fossil group candidate. For each system, we recomputed the magnitude gaps between the two brightest galaxies ($\Delta m_{12}$) and the first and fourth ranked galaxies ($\Delta m_{14}$) within 0.5 $R_{{\rm 200}}$. We consider fossil systems those with $\Delta m_{12} \ge 2$ mag or $\Delta m_{14} \ge 2.5$ mag within the errors. We find that 15 candidates turned out to be fossil systems. Their observational properties agree with those of non-fossil systems. Both follow the same correlations, but fossils are always extreme cases. In particular, they host the brightest central galaxies and the fraction of total galaxy light enclosed in the central galaxy is larger in fossil than in non-fossil systems. Finally, we confirm the existence of genuine fossil clusters. Combining our results with others in the literature, we favor the merging scenario in which fossil systems formed due to mergers of $L^\ast$ galaxies. The large magnitude gap is a consequence of the extreme merger ratio within fossil systems and therefore it is an evolutionary effect. Moreover, we suggest that at least one candidate in our sample could represent a transitional fossil stage.Comment: 14 pages, 11 figures, accepted for publication in A&