Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Biol Theory ; 6(4): 293-300, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23396655

RESUMEN

My brand of evolutionary economics recognizes, highlights, that modern economies are always in the process of changing, never fully at rest, with much of the energy coming from innovation. This perspective obviously draws a lot from Schumpeter. Continuing innovation, and the creative destruction that innovation engenders, is driving the system. There are winners and losers in the process, but generally the changes can be regarded as progress. The processes through which economic activity and performance evolve has a lot in common with evolution in biology. In particular, at any time the economy is marked by considerable variety, there are selection forces winnowing on that variety, but also continuing emergence of new ways of doing things and often economic actors. But there also are important differences from biological evolution. In particular, both innovation and selection are to a considerable degree purposive activities, often undertaken on the basis of relatively strong knowledge.

2.
Catheter Cardiovasc Interv ; 68(2): 183-92, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16810699

RESUMEN

OBJECTIVES: We wished to determine the feasibility and early safety of external beam radiation therapy (EBRT) used following balloon aortic valvuloplasty (BAV) to prevent restenosis. BACKGROUND: BAV for calcific aortic stenosis (AS) has been largely abandoned because of high restenosis rates, i.e., > 80% at 1 year. Radiation therapy is useful in preventing restenosis following vascular interventions and treating other benign noncardiovascular disorders. METHODS: We conducted a 20-patient, pilot study evaluating EBRT to prevent restenosis following BAV in elderly patients with calcific AS. Total doses ranging from 12-18 Gy were delivered in fractions over a 3-5 day post-op period to the aortic valve. Echocardiography was performed pre and 2 days post-op, 1, 6, and 12 months following BAV. RESULTS: One-year follow-up is completed (age 89 +/- 4). There were no complications related to EBRT. Eight patients died prior to 1 year; 5 of 10 (50%) in the low-dose (12 Gy) group and 3 of 10 (30%) in the high-dose (15-18 Gy) group. None of these 8 patients had restenosis, i.e., > 50% loss of the initial AVA gain, and only three deaths were cardiac in origin. One patient underwent aortic valve replacement and none repeated BAV. By 1 year, 3 of the initial 10 (30%) in the low-dose group and 1 of 9 (11%) in the high-dose group demonstrated restenosis (21% overall). CONCLUSIONS: EBRT following BAV in elderly patients with AS is feasible, free of early complications, and holds promise in reducing the 1 year restenosis rate in a dose-dependent fashion.


Asunto(s)
Estenosis de la Válvula Aórtica/prevención & control , Braquiterapia , Cateterismo , Anciano de 80 o más Años , Aorta/efectos de la radiación , Estenosis de la Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/terapia , Terapia Combinada , Femenino , Humanos , Masculino , Proyectos Piloto , Estudios Prospectivos , Radioterapia/métodos , Dosificación Radioterapéutica , Recurrencia
3.
Philos Trans A Math Phys Eng Sci ; 361(1809): 1635-53, 2003 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-12952678

RESUMEN

Modern humans possess an enormous amount of 'know-how' that enables them to do things that early humans could not dream of doing. This paper explores some promising connections between two bodies of empirical research and theorizing that bear on technological know-how and its advance. Cognitive science is concerned with the nature and mechanisms of human knowing. The focus traditionally has not been on the knowledge involved in complex technologies, nor on the processes through which human know-how has advanced over time. However, certain recent developments in this field provide a nice linkage with the implicit cognitive theorizing used by scholars who study the advance of technology. And a number of the debates in the two fields are similar.


Asunto(s)
Evolución Biológica , Comprensión , Evolución Cultural , Conocimiento , Aprendizaje , Evaluación de la Tecnología Biomédica , Tecnología/tendencias , Cognición , Humanos
4.
Philos Trans A Math Phys Eng Sci ; 361(1809): 1691-708, 2003 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-12952681

RESUMEN

The advance of technology proceeds through an evolutionary process, with many different new departures in competition with each other and with prevailing practice, and with ex-post selection determining the winners and losers. In modern times what gives power to the process is the strong base of scientific and technological understanding and technique that guides the efforts of those seeking to advance the technology. Most of that base is part of a commons open to all who have expertise in a field. The proprietary aspects of technology traditionally have comprised a small topping on the commons. But recently parts of the commons have become privatized. While the justification for the policies and actions that have spurred privatization of the commons is that this will spur technological progress, the argument here is that the result can be just the opposite.


Asunto(s)
Difusión de la Información/ética , Patentes como Asunto , Política Pública , Ciencia/métodos , Ciencia/tendencias , Transferencia de Tecnología , Tecnología/tendencias , Difusión de la Información/legislación & jurisprudencia , Difusión de la Información/métodos , Propiedad , Sector Público/ética , Sector Público/tendencias , Ciencia/ética , Ciencia/legislación & jurisprudencia , Tecnología/economía , Tecnología/ética , Tecnología/métodos
5.
Acad Med ; 77(12 Pt 2): 1392-9, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12480650

RESUMEN

The authors examine the presumption that basic scientific research is most effectively utilized when the findings of that research are openly disseminated without significant restriction, while research with more practical application should be the prerogative of private enterprise. However, many fields, including molecular biology generally and genomics in particular, lie in the intersection between basic research and application. Moreover, institutional boundaries that once reasonably sharply demarcated basic research from technological development have grown porous, with more academic research finding application in industry. The authors consider the Human Genome Project and rival industry sequencing efforts as a case in point of the new political economy of scientific research. Since the inception of the Human Genome Project, there has been general agreement among researchers that the project would be most advantageous to science if the sequence data were made publicly available, quickly and without restriction. Many of these arrangements required federal agencies and some universities to "maneuver around" the Bayh-Dole Act. In several cases, most notably genomic sequences and the SNPs (i.e., single nucleotide polymorphisms) consortium, it was the pharmaceutical industry that initiated or helped enable the project to ensure open and unencumbered access to information, the type of access that has historically been the provenance of academia and the raison d'être of academic research. The authors conclude by reasserting the value of public science as a broadly valuable and enabling social commitment, not limited simply to the products or technologies it spawns.


Asunto(s)
Genoma Humano , Propiedad/legislación & jurisprudencia , Patentes como Asunto/legislación & jurisprudencia , Sector Privado/legislación & jurisprudencia , Sector Público/legislación & jurisprudencia , Conducta Cooperativa , Regulación Gubernamental , Humanos , Estados Unidos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...