The synergic relationship between physiology, ecology, and evolutionary process makes the body-si... more The synergic relationship between physiology, ecology, and evolutionary process makes the body-size distribution (BSD) an essential component of the community ecology. Body size is highly susceptible to environmental change, and extreme upheavals, such as during a mass extinction event, could exert drastic changes on a taxon's BSD. It has been hypothesized that the Late Triassic mass extinction event (LTE) was triggered by intense global warming, linked to massive volcanic activity associated with the Central Atlantic Magmatic Province. We test the effects of the LTE on the BSD of fossil bivalve assemblages from three study sites spanning the Triassic/Jurassic boundary in the United Kingdom. Our results show that the effects of the LTE were rapid and synchronous across sites, and the BSDs of the bivalves record drastic changes associated with species turnover. No phylogenetic signal of size selectivity was recorded, although semi-infaunal species were apparently most susceptible...
En este artículo se analiza el modo en que René Zavaleta utilizó y desarrolló el pensamiento de G... more En este artículo se analiza el modo en que René Zavaleta utilizó y desarrolló el pensamiento de Gramsci en el contexto político-social latinoamericano, en especial el boliviano, la manera en que integró la teoría del valor de Marx con la teoría de la hegemonía de Gramsci incorporando la idea de que la política es un conjunto de prácticas de articulación de lo social en un proceso de construcción histórica y de organización de la cultura, es decir, de articulación de una totalidad social. Zavaleta entendía por forma primordial el grado en que se produce la articulación entre Estado y sociedad civil, y el conjunto de mediaciones a través de las cuales ésta se realiza. Reelaboró la idea de lo nacional-popular utilizando los conceptos de bloque histórico y reforma intelectual y moral desarrollados por Gramsci. No obstante, Zavaleta va más allá en cuanto a la noción de masa y centralidad proletaria. Bajo el concepto de masa, pensó una situación en que la acción política tiene formas auto...
ACUTE appendicitis is one of the most important surgical emergencies. Too often there is lack of ... more ACUTE appendicitis is one of the most important surgical emergencies. Too often there is lack of appreciation of the fact that acute appendicitis is common to all ages, that it is the most frequent cause of acute surgical abdominal disease and may be one of the most treacherous. The mortality attending appendicitis becomes significant when perforation occurs. This fact continues to make this subject of paramount surgical interest. Although the recent decline in appendicitis mortality in this country is striking, yet nearly 5000 persons died of perforated appendicitis in the United States last year.2 This decline has occurred partly because of a more universal awareness of the seriousness and the rapid progress which the disease process in the appendix may take, with the result that appendectomy is being done with increasing frequency before perforation occurs. The reduced mortality from acute perforative appendicitis must be credited to better management of these difficult cases. The treatment includes not only proper operative procedures but the use of antibiotics, blood plasma, parenteral fluids and improved anesthesia. Ochsner 1o believes that to our discredit we have become complacent about appendicitis because of our increasing interest in more complicated and dramatic surgery. Death from nonperforative acute appendicitis is usually attributable to secondary factors, such as embolism, cardiovascular disease, pulmonary complications and untoward effects of anesthesia. When appendectomy is performed before rupture, the mortality is 0.3 per cent or less, even when deaths from all causes are included. In sharp contrast to this favorable picture is the high mortality and morbidity attendant upon acute ruptured appendicitis. Following per
At no time during the registration for the degree of Doctor of Philosophy has the author, Luis Fe... more At no time during the registration for the degree of Doctor of Philosophy has the author, Luis Felipe Opazo Mella, been registered for any other University award without prior agreement of the Graduate Committee. This study was financed with the aid of CONICYT, an official body of the Chilean government and the ALBAN Program of European community scholarships. A programme of advanced study was undertaken, which included the extensive reading of literature relevant to the research project and attendance at international conferences on:
The synergic relationship between physiology, ecology, and evolutionary process makes the body-si... more The synergic relationship between physiology, ecology, and evolutionary process makes the body-size distribution (BSD) an essential component of the community ecology. Body size is highly susceptible to environmental change, and extreme upheavals, such as during a mass extinction event, could exert drastic changes on a taxon's BSD. It has been hypothesized that the Late Triassic mass extinction event (LTE) was triggered by intense global warming, linked to massive volcanic activity associated with the Central Atlantic Magmatic Province. We test the effects of the LTE on the BSD of fossil bivalve assemblages from three study sites spanning the Triassic/Jurassic boundary in the United Kingdom. Our results show that the effects of the LTE were rapid and synchronous across sites, and the BSDs of the bivalves record drastic changes associated with species turnover. No phylogenetic signal of size selectivity was recorded, although semi-infaunal species were apparently most susceptible...
En este artículo se analiza el modo en que René Zavaleta utilizó y desarrolló el pensamiento de G... more En este artículo se analiza el modo en que René Zavaleta utilizó y desarrolló el pensamiento de Gramsci en el contexto político-social latinoamericano, en especial el boliviano, la manera en que integró la teoría del valor de Marx con la teoría de la hegemonía de Gramsci incorporando la idea de que la política es un conjunto de prácticas de articulación de lo social en un proceso de construcción histórica y de organización de la cultura, es decir, de articulación de una totalidad social. Zavaleta entendía por forma primordial el grado en que se produce la articulación entre Estado y sociedad civil, y el conjunto de mediaciones a través de las cuales ésta se realiza. Reelaboró la idea de lo nacional-popular utilizando los conceptos de bloque histórico y reforma intelectual y moral desarrollados por Gramsci. No obstante, Zavaleta va más allá en cuanto a la noción de masa y centralidad proletaria. Bajo el concepto de masa, pensó una situación en que la acción política tiene formas auto...
ACUTE appendicitis is one of the most important surgical emergencies. Too often there is lack of ... more ACUTE appendicitis is one of the most important surgical emergencies. Too often there is lack of appreciation of the fact that acute appendicitis is common to all ages, that it is the most frequent cause of acute surgical abdominal disease and may be one of the most treacherous. The mortality attending appendicitis becomes significant when perforation occurs. This fact continues to make this subject of paramount surgical interest. Although the recent decline in appendicitis mortality in this country is striking, yet nearly 5000 persons died of perforated appendicitis in the United States last year.2 This decline has occurred partly because of a more universal awareness of the seriousness and the rapid progress which the disease process in the appendix may take, with the result that appendectomy is being done with increasing frequency before perforation occurs. The reduced mortality from acute perforative appendicitis must be credited to better management of these difficult cases. The treatment includes not only proper operative procedures but the use of antibiotics, blood plasma, parenteral fluids and improved anesthesia. Ochsner 1o believes that to our discredit we have become complacent about appendicitis because of our increasing interest in more complicated and dramatic surgery. Death from nonperforative acute appendicitis is usually attributable to secondary factors, such as embolism, cardiovascular disease, pulmonary complications and untoward effects of anesthesia. When appendectomy is performed before rupture, the mortality is 0.3 per cent or less, even when deaths from all causes are included. In sharp contrast to this favorable picture is the high mortality and morbidity attendant upon acute ruptured appendicitis. Following per
At no time during the registration for the degree of Doctor of Philosophy has the author, Luis Fe... more At no time during the registration for the degree of Doctor of Philosophy has the author, Luis Felipe Opazo Mella, been registered for any other University award without prior agreement of the Graduate Committee. This study was financed with the aid of CONICYT, an official body of the Chilean government and the ALBAN Program of European community scholarships. A programme of advanced study was undertaken, which included the extensive reading of literature relevant to the research project and attendance at international conferences on:
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