Two devices, each of which measure water velocity; on the right is an acoustic device that is permanently maintained at Gumbo Limbo by PI Rene Price; on the left is a 3D camera with a long fiberoptic lens, deployed for testing purposes by collaborator Evan Variano.

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Sasha Wagner collects surface water samples to assess dissolved organic matter sources and reactivity along the Harney River

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Hydrologic measurements and implications for tree island formation within Everglades National Park

Tree islands in the Shark River Slough of the Everglades National Park (ENP), in the southern state of Florida in the United States, are part of a wetland system of densely vegetated ridges interspersed within relatively open sloughs. Human alteration of this system has had dramatic negative effects on the landscape of the region and restoration efforts will require adjusting the hydrology of the region to assure the preservation of these important ecologic features. The primary objectives of this study were to document the hydrology in the vicinity of tree islands in ENP by measuring velocities in time and space and by characterizing suspended sediments. The results of such measurements were interpreted with respect to factors that may limit tree island growth. The measurements were conducted in the vicinity of three tree islands known as Black Hammock (BH), Gumbo Limbo (GL), and an unnamed island that was named for this study as Satin Leaf (SL). Acoustical Doppler Velocity (ADV) meters were used for measuring the low velocities of the Everglades water flow. Properties of suspended sediments were characterized through measurements of particle size distribution, turbidity, concentration and particle density. Mean velocities observed at each of the tree islands varied from 0.9 to 1.4 cm/s. Slightly higher mean velocities were observed during the wet season (1.2–1.6 cm/s) versus the dry season (0.8–1.3 cm/s). Maximum velocities of more than 4 cm/s were measured in areas of Cladium jamaicense die-off and at the hardwood hammock (head) of the islands. At the island’s head, water is channelized around obstructions such as tree trunks in relatively rapid flow, which may limit the lateral extent of tree island growth. Channelization is facilitated by shade from the tree canopy, which limits the growth of underwater vegetation thereby minimizing the resistance to flow and limiting sediment deposition. Suspended sediment concentrations were low (0.5–1.5 mg/L) at all study sites and were primarily of organic origin. The mean particle size of the suspended sediments was 3 μm with a distribution that was exponential. Critical velocities needed to cause re-suspension of these particles were estimated to be above the actual velocities observed. Sediment transport within the water column appears to be at a near steady state during the conditions evaluated with low rates of sediment loss balanced by presumably the release of equivalent quantities of particles of organic origin. Existing hydrologic conditions do not appear to transport sufficient suspended sediments to result in the formation of tree islands. Of interest would be to collect hydrologic and sediment transport data during extreme hydrologic events to determine if enough sediment is transported under these conditions to promote sufficient sediment accumulations.

Impacts of hurricanes on surface water flow within a wetland

Between 2001 and 2005, seven category 3 or higher major hurricanes made landfall within the US. The hydrologic impacts of these distinct climatic phenomena frequently occurring in wetland watersheds, however, are not well understood. The focus of this study was to evaluate the impacts of hurricane wind and rainfall conditions on water velocity and water elevations within the study wetland, the Florida Everglades. Specifically water velocity data was measured near two tree islands (Gumbo Limbo (GL) and Satin Leaf (SL)) and wind speed, water elevation, and rainfall were obtained from nearby wind observation stations. During the direct impacts of the hurricanes (Hurricanes Katrina and Wilma), water speed, flow direction, and hydraulic gradients were altered, and the extent of variation was positively related to wind characteristics, with significant alterations in flow direction at depth during Hurricane Wilma due to higher wind speeds. After the direct impacts, the longer lasting effect of hurricanes (time scale of a few days) resulted in altered flow speeds that changed by 50% or less. These longer lasting changes in flow speeds may be due to the redistribution of emergent vegetation.

Queensland flood inquiry recalled as victims left in limbo

"The recalling of the Queensland Flood Commission of Inquiry for another nine days of hearings from today has renewed fears of Grantham residents that the review has not had sufficient time to properly investigate the causes of the 12 deaths in the town on January 10 last year. Grantham businesswoman Lisa Spierling, who has been liaising with the families of the flood victims, says recalling the inquiry to determine what operational strategy was being used by Wivenhoe Dam managers in the days before Ipswich and Brisbane flooded last year, is more than four times the entire sitting time that was allocated to the Lockyer Valley. The inquiry heard less than two days of evidence in April last year about the events in the Lockyer Valley, including Grantham."

El limbo de la penalización de la dosis personal

Trabajo de grado que aborda la problemática de la penalización de la dosis personal de droga en Colombia

¿Punto final al limbo legal de las actividades de inteligencia en Colombia?

Los servicios de inteligencia en Colombia han operado durante casi sesenta años sin una regulación integral que demarque sus funciones y sus límites. Recientemente fue aprobado en el Congreso de la República, y en gran parte avalado por la Corte Constitucional, un proyecto de ley que pretende poner fin a esta omisión histórica. El presente artículo tiene como propósito revisar qué tan adecuada resulta la regulación que este proyecto de ley hace de dos aspectos relacionados con los servicios de inteligencia –el alcance del secreto y los controles a su funcionamiento– de cara a la protección de derechos como la intimidad, el acceso a la información y la verdad. La tesis que se defiende es que este proyecto de ley prevé aspectos positivos con relación a los dos temas mencionados, pero deja abiertos vacíos importantes que pueden llevar a que los servicios de inteligencia se aparten de sus funciones y sean utilizados para desconocer los derechos de las personas.

Limbo, hiperuranio, ciudadanía, humor y risa.

El uso del sentido del humor en las aulas mejora los niveles de motivación y de atención de los alumnos. Por ello se realiza un análisis comparando técnicas tradicionales con el uso didáctico de la risa. El sentido del humor mejora la autoestima de los profesores puesto que mejoran las relaciones con los alumnos y se reducen los problemas de rebeldía en las aulas. Además describen una serie de aplicaciones prácticas del sentido del humor y un conjunto de mejoras observadas en los alumnos: promueve la creatividad y el manejo de emociones; se puede usar satisfactoriamente en la resolución de conflictos. Finalmente se describen una serie de ejemplos de actuaciones que pueden llevarse a cabo en el aula.

El limbo educativo.

El autor hace unas reflexiones sobre el riesgo de que la educación se convierta en un código de conocimientos inadecuados a las circunstancias actuales. Espera de la escuela que se adecue a la realidad, que prepare para vivir descubriendo la realidad para, si aun es posible, modificarla. Educar para vivir, no solo para saber, tarea que compete a educadores, políticos y padres; porque lo que no se puede es seguir en el limbo de la marginación.

Lives in limbo : voices of refugees under temporary protection

Lives in Limbo contains the words of 35 recognised refugees languishing in Australia on temporary protection visas. But it is not merely a succession of stories. It locates these experiences solidly within the historical, political and legal context in which they are endured.

Estimativa da área foliar de crotalaria juncea l. a partir de dimensões lineares do limbo foliar

Knowledge of the leaf area plant are needed for agronomic and physiological studies involving plant growth. The aim of this study was to obtain a mathematical model using linear measures of leaf dimensions, which will allow the estimation of leaf area of Crotalaria juncea L. Correlation studies were conducted involving real leaf area (Sf) and leaf length (C), maximum leaf width (L) and the product between C and L. All tested models (linear, exponential or geometric) provided good estimation of leaf area (above 87%). The better fit was attained using linear model, passing or not through the origin. From a practical viewpoint, it is suggested to use the linear model involving the C and L product, using a linear coefficient equal to zero. Estimation of leaf area of Crotalaria juncea L. can be obtained using the model Sf = 0.7160 x (C*L) with a determination coefficient of 0.9712.