Intermediate Kinematics Produce Inferior Feeding Performance in a Classic Case of Natural Hybridization

Selection on naturally occurring hybrid individuals is a key component of speciation theory, but few studies examine the functional basis of hybrid performance. We examine the functional consequences of hybridization in nature, using the freshwater sunfishes (Centrarchidae), where natural hybrids have been studied for more than a century and a half. We examined bluegill (Lepomis macrochirus), green sunfish (Lepomis cyanellus), and their naturally occurring hybrid, using prey-capture kinematics and morphology to parameterize suction-feeding simulations on divergent parental resources. Hybrid individuals exhibited kinematics intermediate between those of the two parental species. However, performance assays indicated that hybrids display performance most similar to the worse-performing species for a given parental resource. Our results show that intermediate hybrid phenotypes can be impaired by a less-than-intermediate performance and hence suffer a larger loss in fitness than could be inferred from morphology alone.

The Effects of Density, Spatial Pattern, and Competitive Symmetry on Size Variation in Simulated Plant Populations

Patterns of size inequality in crowded plant populations are often taken to be indicative of the degree of size asymmetry of competition, but recent research suggests that some of the patterns attributed to size‐asymmetric competition could be due to spatial structure. To investigate the theoretical relationships between plant density, spatial pattern, and competitive size asymmetry in determining size variation in crowded plant populations, we developed a spatially explicit, individual‐based plant competition model based on overlapping zones of influence. The zone of influence of each plant is modeled as a circle, growing in two dimensions, and is allometrically related to plant biomass. The area of the circle represents resources potentially available to the plant, and plants compete for resources in areas in which they overlap. The size asymmetry of competition is reflected in the rules for dividing up the overlapping areas. Theoretical plant populations were grown in random and in perfectly uniform spatial patterns at four densities under size‐asymmetric and size‐symmetric competition. Both spatial pattern and size asymmetry contributed to size variation, but their relative importance varied greatly over density and over time. Early in stand development, spatial pattern was more important than the symmetry of competition in determining the degree of size variation within the population, but after plants grew and competition intensified, the size asymmetry of competition became a much more important source of size variation. Size variability was slightly higher at higher densities when competition was symmetric and plants were distributed nonuniformly in space. In a uniform spatial pattern, size variation increased with density only when competition was size asymmetric. Our results suggest that when competition is size asymmetric and intense, it will be more important in generating size variation than is local variation in density. Our results and the available data are consistent with the hypothesis that high levels of size inequality commonly observed within crowded plant populations are largely due to size‐asymmetric competition, not to variation in local density.

Volume 11, Number 4: November/December 2005

Page 2 - The vice provost for University Libraries writes about the many efforts underway to archive electronic resources for future use. • The director of the Tri-Campus Libraries comments on freedom of speech & the academic library. Page 3 - Manuscripts from Archives & Special Collections record the recollections of a Civil War nurse, a Connecticut naturalist, and a prosecutor at the Nuremberg Trials. Page 4 - A WPA mural by James Daugherty is rescued and installed in the Jeremy Richard Library. • Access Services finds new ways to improve services for library users. Page 5 - A renovated UConn Health Center Library is transformed from a warehouse for print into an information commons. Page 6 - Staff news

La presencia de Darwin en William Henry Hudson

W. H. Hudson tuvo un contacto muy temprano con El origen de las especies; probablemente haya leído el libro el mismo año de su aparición (1859). Esta lectura lo acercó a una filosofía naturalista que, a la vez, lo alejó de la formación materna en cuestión religiosa, y lo condujo a asumir una posición evolucionista crítica. De hecho, contradijo observaciones de Darwin que éste revisó, además de mencionarlo en la segunda edición de El origen de las especies (1888). Asimismo, son numerosas las citas que Hudson hace de Darwin en sus textos. Aunque pueden marcarse diferencias, ciertos tópicos generales del evolucionismo, son fácilmente reconocibles a lo largo de su producción. El trabajo pretende avanzar sobre estos aspectos para identificar cuán profundamente caló en su concepción del mundo la perspectiva evolucionista.

Telurismo, Vanguardia y Tiempo Literario en Doña Bárbara

Para legitimar su propia modernidad, los escritores y críticos asociados al Boom solían describir a Rómulo Gallegos como un autor arcaico, neonaturalista o neorromántico, todavía activo en el siglo XX. Este artículo se propone reconstruir el horizonte de expectativas que cimentó el prestigio inicial de Doña Bárbara. Se argumenta que su éxito se debió al menos parcialmente a la proximidad —que después dejaría de percibirse con claridad— entre el regionalismo o mundonovismo y la estética de vanguardia. La comprensión del interés de Gallegos en la cinematografía resulta esencial para entender dichas afinidades.

David Hume y su adhesión inconsciente al escepticismo pirrónico

Por sus propias palabras y por las de la mayoría de sus intérpretes, se ha considerado a Hume un escéptico mitigado. Sin embargo, la distinción hecha por el filósofo entre escepticismo pirrónico y académico no es correcta en absoluto. El objetivo de este trabajo es mostrar que quizá la filosofía escéptico-naturalista de Hume no se halla tan distanciada del pirronismo auténtico como lo afirma su propio autor. En tal sentido, intentaremos desentrañar si el 'mitigado' escepticismo del escocés no esconde cierto pirronismo inconsciente, señalando que la clave puede hallarse en el desenlace del escepticismo humeano: la 'cura de la naturaleza'

David Hume y su adhesión inconsciente al escepticismo pirrónico

Por sus propias palabras y por las de la mayoría de sus intérpretes, se ha considerado a Hume un escéptico mitigado. Sin embargo, la distinción hecha por el filósofo entre escepticismo pirrónico y académico no es correcta en absoluto. El objetivo de este trabajo es mostrar que quizá la filosofía escéptico-naturalista de Hume no se halla tan distanciada del pirronismo auténtico como lo afirma su propio autor. En tal sentido, intentaremos desentrañar si el 'mitigado' escepticismo del escocés no esconde cierto pirronismo inconsciente, señalando que la clave puede hallarse en el desenlace del escepticismo humeano: la 'cura de la naturaleza'

David Hume y su adhesión inconsciente al escepticismo pirrónico

Por sus propias palabras y por las de la mayoría de sus intérpretes, se ha considerado a Hume un escéptico mitigado. Sin embargo, la distinción hecha por el filósofo entre escepticismo pirrónico y académico no es correcta en absoluto. El objetivo de este trabajo es mostrar que quizá la filosofía escéptico-naturalista de Hume no se halla tan distanciada del pirronismo auténtico como lo afirma su propio autor. En tal sentido, intentaremos desentrañar si el 'mitigado' escepticismo del escocés no esconde cierto pirronismo inconsciente, señalando que la clave puede hallarse en el desenlace del escepticismo humeano: la 'cura de la naturaleza'

Data compilation of respiration, feeding, and growth rates of marine pelagic organisms

The metabolic rate of organisms may either be viewed as a basic property from which other vital rates and many ecological patterns emerge and that follows a universal allometric mass scaling law; or it may be considered a property of the organism that emerges as a result of the organism's adaptation to the environment, with consequently less universal mass scaling properties. Data on body mass, maximum ingestion and clearance rates, respiration rates and maximum growth rates of animals living in the ocean epipelagic were compiled from the literature, mainly from original papers but also from previous compilations by other authors. Data were read from tables or digitized from graphs. Only measurements made on individuals of know size, or groups of individuals of similar and known size were included. We show that clearance and respiration rates have life-form-dependent allometries that have similar scaling but different elevations, such that the mass-specific rates converge on a rather narrow size-independent range. In contrast, ingestion and growth rates follow a near-universal taxa-independent ~3/4 mass scaling power law. We argue that the declining mass-specific clearance rates with size within taxa is related to the inherent decrease in feeding efficiency of any particular feeding mode. The transitions between feeding mode and simultaneous transitions in clearance and respiration rates may then represent adaptations to the food environment and be the result of the optimization of tradeoffs that allow sufficient feeding and growth rates to balance mortality.

Metodologia para reconhecimento de perfil cognitivo: uma abordagem computacional pautada pela teoria das inteligências múltiplas.

A área da Tecnologia da Informação no Brasil sofre um problema latente com a falta de planejamento e atrasos constantes em projetos, determinando para os profissionais vinculados a ela um ambiente altamente desmotivador para a condução de seus trabalhos. Supõe-se que o que possa corroborar para tal problema seja a formação educacional deficitária dos indivíduos que atuam neste segmento, principalmente aqueles relacionados a cargos executivos e que estejam exercendo atividades de gestão. De acordo com teóricos como Edgard Morin (2004), em se tratando de educação fundamental, média ou superior os aspectos educacionais podem ser considerados deficitários justamente porque, ao segmentar o conhecimento, eles promovem uma alienação do indivíduo, eliminando sua capacidade criativa e reflexiva. Seria interessante, portanto, que ao avaliar a capacidade cognitiva de uma pessoa, a inteligência a ser mensurada não seja abordada através de um único espectro de conhecimento, mas através de muitos deles. A teoria das Inteligências Múltiplas, desenvolvida por Howard Gardner vem de encontro a essa necessidade, pois de acordo com o autor, a inteligência de um indivíduo deve ser mensurada através de uma gama de nove espectros: Linguística, Musical, Lógico-Matemática, Espacial, Corporal Cinestésica, Interpessoal, Intrapessoal, Naturalista e Existencial. Isto posto, este trabalho aborda uma metodologia computacional para classificação e descoberta de padrões em indivíduos, sejam esses alunos ou profissionais graduados, de uma determinada área. Além da metodologia, foi proposto um estudo de caso, considerando cursos superiores relacionados à área de Computação no Brasil.

An history of fungusses, growing about Halifax ... By James Bolton.

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An history of fungusses, growing about Halifax ... By James Bolton.

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