Latitudinal and seasonal egg-size variation of the anchoveta (Engraulis ringens) off the Chilean coast

The anchoveta Engraulis ringens is widely distributed along the eastern South Pacific (from 4° to 42°S; Serra et al., 1979) and it has also supported one of the largest fisheries of the world over the last four decades. However, there are few interpopulation comparisons for either the adult or the younger stages. Reproductive traits, such as fecundity or spawning season length, are known to vary with latitude for some fish species (Blaxter and Hunter, 1982; Conover, 1990; Fleming and Gross, 1990; Castro and Cowen, 1991), and latitudinal trends for some early life history traits, such as egg size and larval growth rates, have been reported for others clupeiforms and other fishes (Blaxter and Hempel, 1963; Ciechomski, 1973; Imai and Tanaka, 1987, Conover 1990, Houde 1989). However, there is no published information on potential latitudinal trends during the adult or the early life history of the anchoveta, even though this type of information may help in understanding recruitment variability, especially during recurring large scale events (such as El Niño or La Niña) that affect the entire species range

Variabilidad en el tamaño de ovocitos y fecundidad parcial de anchoveta (Engraulis ringens, Jenyns 1842) en dos áreas de desove de la costa de Chile

Utilising histological preparations of ovaries from Engraulis ringens females collected in two contrasting spawning habitats along the Chilean coast, we assess the variability in oocyte size and batch fecundity during the peak spawning seasons in three years. The effects of female size (length and weight), batch fecundity and mean sea surface temperature on oocyte size were also examined. Results showed larger oocytes and lower batch fecundity in females from the southern area. Oocyte volume differences persisted inter-annually and were not explained by differences in female sizes. Since ovary weight was similar between areas, the cost of producing larger oocytes in the south population seems to be a fecundity reduction. The latitudinal variations in oocyte number and size seem to be determined by the predominant environmental conditions in each habitat. Hence, female E. ringens seem to adapt their reproductive tactics by producing eggs sizes and quantities that favour survival of their offspring under the environmental conditions in which they are to develop.Utilizando preparaciones histológicas de ovarios de anchovetas (Engraulis ringens) colectadas en dos hábitats contrastantes a lo largo de la costa de Chile, se estudia la variabilidad en tamaño de ovocitos y fecundidad parcial en la estación de máximo desove durante tres años. Los efectos de tamaño de hembra (longitud total y peso total), fecundidad parcial y temperatura superficial del mar sobre el tamaño de los ovocitos, también fueron investigados. Los resultados mostraron ovocitos más grandes y menor fecundidad en hembras de la zona sur. Las diferencias en volumen de ovocitos persistieron inter-anualmente y no fueron explicadas por diferencias en el tamaño de las hembras. Dado que los pesos de los ovarios fueron similares entre zonas, el coste de producir ovocitos más grandes en la población del sur sería la reducción en la fecundidad. Las variaciones latitudinales en número y tamaño de ovocitos parecen ser determinadas por las condiciones ambientales predominantes en cada hábitat de desove. De este modo, las hembras de E. ringens adaptarían sus tácticas reproductivas produciendo tamaño y cantidades de huevos que favorezcan la supervivencia de sus descendientes a las condiciones ambientales en las que se desarrollarán

Larvae of Dactylopsaron dimorphicum (Perciformes: Percophidae) from oceanic islands in the southeast Pacific

Percophids are a family of small marine benthic fishes common over soft bottoms from inshore to the outer slopes in tropical to temperate regions of the Atlantic and in the Indo-West and southeast Pacific (Reader and Neira, 1998; Okiyama, 2000). Five species belonging to four genera have been recorded around the Salas y Gómez Ridge in the southeast Pacific, all of which are endemic to the area except for Chrionema chryseres, a species which also occurs off the Hawaiian Islands and Japan (Parin, 1985, 1990; Parin et al., 1997). Of these five species, larval stages have been described only for Osopsaron karlik and Chrionema pallidum (Belyanina 1989, 1990)

Semantic based visualization

Visualization is the process of mapping data into visual dimensions to create a visual representation to amplify cognition. A successful visualization allows the user to gain insight into the data in other words to communicate different aspect of the data in an effective way. Even with today’s visualization systems that give the user a considerable control over the visualization process, it can be difficult to produce an effective visualization. A strategy to improve this situation is to guide the user in the selection of the parameters involved in the visualization. Our system goal of the research describe in this work is to develop a visualization that can be adapted to all data domains. By considering the semantic of the data together with the semantic of the stages through the visualization process it is intended to determinate all the characteristics of an effective visualization. This will guide the user through the stages of the visualization pipeline.Eje: Computación gráfica, visualización e imágenesRed de Universidades con Carreras en Informática (RedUNCI

A Semantics-based visualization building process

A successful visualization allows the user to gain insight into the data in an effective way. Even with today’s visualization systems that give the user a considerable control over the visualization process, it can be difficult to produce an effective visualization. This paper is a step forward to achieve a visualization system that assists the user in the configuration and preparation of the visualization by considering both the semantic of the data and the semantic of the stages, through all the visualization process. In this article we present a system for file hierarchies visualization where the color assignment and the configuration of the visualization technique are carried out by reasoning processes. This work sets the way forward for the integration of reasoning in the visualization process.Presentado en el VIII Workshop Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI

Semantic Based Visualization

Visualization is the process of mapping data into visual dimensions to create a visual representation to amplify cognition. Visual representations are essential aids to human cognitive tasks and are valued to the extent that they provide stable and external reference points upon which dynamic activities and thought processes may be calibrated and upon which models and theories can be tested and confirmed. The active use and manipulation of visual representations makes many complex and intensive cognitive tasks feasible. A visual representation is able to convey relationships among many elements in parallel and provides an individual with directly observable memory. A successful visualization allows the user to gain insight into the data, in other words to communicate different aspect of the data in an effective way. Even with today’s visualization systems that give the user a considerable control over the visualization process, it can be difficult to produce an effective visualization. To obtain useful results, a user had to know which questions to pose. Problems had to be framed in very precise terms. A strategy to improve this situation is to guide the user in the selection of the parameters involved in the visualization. Our research goal is the design of a visualization system that assist the user to do the work, by considering the semantic of the data together with the semantic of the stages through all the visualization process.Eje: Computación Gráfica, Visualización e ImágenesRed de Universidades con Carreras en Informática (RedUNCI

Semantic based visualization: a first approach

Visualization is the process of mapping data into visual dimensions to create a visual representation to amplify cognition. Visual representations are essential aids to human cognitive tasks and are valued to the extent that they provide stable and external reference points upon which dynamic activities and thought processes may be calibrated and upon which models and theories can be tested and confirmed. The active use and manipulation of visual representations makes many complex and intensive cognitive tasks feasible. A visual representation is able to convey relationships among many elements in parallel and provides an individual with directly observable memory. A successful visualization allows the user to gain insight into the data, in other words to communicate different aspect of the data in an effective way. Even with today’s visualization systems that give the user a considerable control over the visualization process, it can be difficult to produce an effective visualization. To obtain useful results, a user had to know which questions to pose. Problems had to be framed in very precise terms. A strategy to improve this situation is to guide the user in the selection of the parameters involved in the visualization. Our research goal is the design of a visualization system that assist the user to do the work, by considering the semantic of the data together with the semantic of the stages through all the visualization process.Eje: Computación Gráfica, Visualización e ImágenesRed de Universidades con Carreras en Informática (RedUNCI

Distributed system load visualization

In this article we show how the interface design for the visualization of distributed system load can benefit from the combination of concepts and techniques from Information Visualization and Human Computer Interaction (HCI). The use of visual representations and interactions to accelerate the insight into complex data is what distinguishes visual analytic software form other types of analytical tools. Visual representations translate data into a visible form that highlights important data features, including commonalities and anomalies. These visual representations helps the users to quickly perceive salient aspects of their data. Every distributed systems administrator must handle a high volume of information and the exploration and analysis of this data is becoming increasingly difficult. We propose an entirely novel approach to visualize the parameters involved in the system load for a distributed system to obtain an effective visualization tool in order to reduce the user cognitive workload and help the user to make the right decisions in a productive way.IV Workshop de Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI