Evolution and the nature of time

The concept of time is critical in evolutionary thought, but rarely has it been considered as an object of theoretical research by evolutionary biologists. Evolution is an organism’s possibility of access to the future; in other words, evolutionary reward is paid out as increased time. Replicating entities are granted time, but for them, time only serves to allow replication and evolution, and to further expand the frontier of time. The present review discusses the possible influence of considering time not as a pure dimension (or an a priori intuitive condition of human experience) but as an object in itself. At least as a metaphor, time can be considered as a self-replicating entity rooted in physical (including biological) beings, with the result of producing dimensional time. Time self-replication forces beings to replicate, which, in turn, further sustains the replication of time. In that sense, time-replication may constitute the driving force, i.e., the basic engine, providing directional energy to the evolutionary process. The philosophical roots, caveats, and perspectives of this hypothesis are presented here. The metaphor of replicating-time plays with the possibility of viewing time not as a merely regulatory component of scientific inquiry but instead, as a real and creative constituent of nature and, for this reason, an object worthy of research in the natural sciences. [Int Microbiol 2005; 8(2):81-91

On the Shifting Balance: the Case of Staphylococcus aureus CC398

The recent study by L. Price et al. [mBio, 3(1):e00305-11, 2012] demonstrating the human origin of the livestock-associated CC398 Staphylococcus aureus provides an excellent example of how bacterial populations can explore a wide range of potential niches and acquire optimal adaptations for life in alternative hosts. The shifting balance theory proposed by Sewall Wright 80 years ago serves as a perfect model for understanding the observed facts: a possibly large CC398 population optimally positioned on the top of a fitness peak for living in a human host probably began evolving long ago by variation, drift, and migration, until it reached the low fitness edge of a neighboring alternative peak in the fitness landscape, one in a livestock host. The bacterial population then evolved again, moving uphill to reach a novel optimal “top of the peak” position in livestock. In the case of CC398, it is worrisome to think that it might readapt to human hosts without losing fitness in livestock; a double-host-adapted organism could certainly be in an optimal position for increasing its virulence and antibiotic resistance

Principales determinantes del precio de los servicios de voz de Telefonía Móvil en Colombia

Este trabajo estudia cuales son algunas de las principales variables que explican los precios de los servicios de voz fijados por las empresas de telefonía móvil en Colombia -- Mediante el análisis de distintas variables que caracterizan este sector, como los precios históricos de todos los operadores, las inversiones realizadas en redes, la participación de mercado y las medidas regulatorias -- Se plantea un modelo de panel de datos, entre el periodo 2005 – 2011, que permite evidenciar la interdependencia que hay entre las distintas compañías a la hora de fijar sus tarifas -- También se evidencia el liderazgo de uno de los competidores y la existencia de una guerra de precios entre los operadore

A Distributed Model Predictive Control (D-MPC) for modular robots in chain configuration

Ingeniero (a) ElectrónicoPregrad

Un ecosistema malalt: la lluita contra la resistència a antibiòtics des d’una perspectiva global

La producció antropogènica d'antibiòtics ha provocat una malaltia dels ecosistemes microbians de dimensió planetària, la repercussió més immediata de la qual per a l'home és la intractabilitat de les infeccions. La comprensió del fenomen i les possibilitats d'intervenció requereixen nous mètodes conceptuals, analítics i tecnològics

Tumor fibroso localizado da pleura: análise de 11 novos casos

ABSTRACTWe present a retrospective revision of a pathology, rare in his incidence (5% of the pleural tumours) and singular in his characteristics, analyzing the presentation forms, surgical treatment and results.The solitary tumours of the pleura are a rare entity, whose biological behaviour is not related with immunohistochemical characteristics; although considered benign, they present sensitive recidivation index and metastization, independently of the volume that they present.The surgery is the only available treatment, and complete surgical excision is decisive.From August 1995 to January 2003, in the casuistry of the Department of Cardiothoracic Surgery in Santa Marta’s Hospital, were analyzed all the patients with the diagnosis of localized fibrous tumour of the pleura (TFLP). In this context, were identified 11 patients with a medium age of 57,54 years old, 6 of them females, in which the diagnosis of located fibrous tumour of the pleura was established; 6 of the tumours were classified as malignant.All the patients were submitted to surgical excision, with different techniques, without significant intra-operative mortality or intra-hospital morbidity, despite the difficulty of surgery in the most voluminous tumours (one of the tumours weight was 2,5 kg).The follow up elapsed between 4 and 84 months (average – 39,4 months).One patient died 13 months after the surgery, after several crises of lung embolism (that began without determinable relationship with the surgery or the initial pathology), despite the controlled ambulatory anti-coagulation.REV PORT PNEUMOL 2003; IX (6): 493-50

Formación ciudadana en Colombia: una propuesta para la universidad desde la perspectiva teórica de Jürgen Habermas

La formación ciudadana se constituye hoy en Colombia en una de las principales problemáticas de la formación universitaria actual. Las cambiantes condiciones del entorno social nacional e internacional, suscitadas por fenómenos como la globalización, las nuevas tecnologías de la información y las comunicaciones, la disminución del papel del estado, entre otros, exigen una movilización y una participación cada vez más activa de ciudadanos íntegros, críticos y reflexivos, responsables y partícipes tanto en la formulación, como en la implementación de políticas públicas, esto supone necesariamente que resulte imprescindible comprender que el ámbito de lo público no se ciñe de manera exclusiva al espacio privilegiado para el ejercicio de las responsabilidades administrativas y la práctica de principios éticos, provenientes de entes de carácter público, sino que éste, en un sentido más amplio, debe manifestarse como el espacio público donde el ejercicio de la opinión pública y la discusión crítica cobren especial importancia en la construcción de aquellas políticas públicas, que dada su pretensión de legitimidad y validez se obligan a la aprobación y al asentimiento ciudadano, constituyendo así su principio y su fi