Retention efficiency for microplastic in a landscape estimated from empirically validated dynamic model predictions

Soils are recipients of microplastic that can be subsequently transferred to the sea. Land sources dominate inputs to the ocean, but knowledge gaps about microplastic retention by land hinder assessments of input rates. Here we present the first empirical evaluation of a dynamic microplastic fate model operating at landscape level. This mechanistic model accounts for hydrology, soil and sediment erosion, particle characteristics and behavior. We predict microplastic concentrations in water and sediments of the Henares river (Spain) within the measurement uncertainty boundaries (error factors below 2 and 10, respectively). Microplastic export from land and discharge by river fluctuates in a non-linear manner with precipitation and runoff variability. This indicates the need of accurate dynamic descriptions of soil and stream hydrology even when modeling microplastic fate and transport in generic scenarios and at low spatio-temporal resolution. A time-averaged landscape retention efficiency was calculated showing 20-50% of the microplastics added to the catchment over a multiannual period were retained. While the analysis reveals persistent uncertainties and knowledge gaps on microplastic sources to the catchment, these results contribute to the quantitative understanding of the role of terrestrial environments in accumulating microplastics, delaying their transport to the sea

Intervención en trastornos infantiles del lenguaje, habla y voz a través de las nuevas tecnologías de la información y la comunicación

Los programas multimedia son esenciales para la intervención logopédica en los trastornos infantiles del habla y forman parte ya de la práctica cotidiana. Objetivos: 1. Conseguir el máximo de desarrollo de las capacidades y habilidades de las personas en los trastornos infantiles del habla. 2. Facilitar materiales que posibiliten el acceso a la comunicación mediante la ejercitación constante en los trastornos del habla y de la voz y consecución de los procesos de habilitación al ampliar las capacidades comunicativas y lingüísticas y la mejora en la calidad de vida en la etapa infantil. 3. Investigar sobre las posibilidades de aplicación que nos ofrece las nuevas tecnologías de la información y de la comunicación, construyendo una herramienta que permita una gestión ágil y permita la mayor diversidad de recursos posibles en los procesos de re educación y rehabilitación en las distintas patologías dentro de la logopedia para los niños en la etapa infantil. 4. Cualificar al logopeda para que pueda incorporar en su actividad rehabilitadora y reeducadora estos medios tecnológicos (tarjeta de voz, soporte informático, comunicación aumentativa). Metodología: Comunicativa y práctica mediante el uso del ordenador y software con el fin de propiciar un intercambio profesional entre los alumnos. Al final se expondrán casos prácticos a través de vídeos de las distintas patologías relacionadas con los trastornos del habla en la etapa infantil. Contenidos: 1. Análisis en el ordenador una herramienta de trabajo o un elemento de ayuda a la comunicación y la terapia rehabilitadora y reeducadora en la logopedia. 2. Controlar y modular la intensidad, tono, soplo o fuerza, tiempo de fonación. 3. Interiorizar el concepto de voz asociado a estímulos visuales. 4. Coordinación sonido y respiración en la emisión de una frase. 5. Desarrollo Fonológico /Léxico /Morfosintáctico… 6. Recursos en la comunicación aumentativa y alternativa a través de internet. 7. Diseño de fichas interactivas para el desarrollo de habilidades Metalingüísticas a través de las TICs. 8. Tarjetas de voz como recurso en la rehabilitación de los trastornos del lenguaje, habla, y voz. 9. Diseño de libros móviles para la comunicación: cuentos, fichas, agenda, diseño de plafones para la comunicación alternativa y aumentativa. Conclusión: Los materiales multimedia se conforman como un aspecto fundamental del trabajo en la intervención logopédica en los trastornos infantiles del habla. Su optimización de las variables implicadas, su facilitación de los aspectos atencionales y su capacidad contrastada para mejorar la motivación de los niños con respecto a otros materiales justifica la necesidad de que los futuros logopedas adquieran una visión global acerca los programas que se utilizan en la práctica clínica con notable eficacia.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Dynamics of color and organic carbon within the Mälaren catchment

Lake Mälaren, located in eastern Sweden, supplies water for drinking use to more than two million people in Stockholm and the surroundings. Water quality is generally rather good; although concern has been raised in the last years due to observed increasing trends in both color and dissolved organic carbon (DOC) in other surface waters in Scandinavia. This may eventually occur in Lake Mälaren. DOC can carry along contaminants and toxic compounds affecting the functioning of water treatment plants. A better understanding of the DOC dynamics within the catchment is essential. This requires an investigation of the spatial and temporal patterns in DOC quality and quantity. The main aim of this project is to produce the basic knowledge that will be useful to predict DOC quality and quantity in Lake Mälaren. The project is structured in two parts: (1) areal mass transport fluxes of color and total organic carbon (TOC) within the catchment, and (2) simulation of DOC concentrations in Fyrisån subcatchment using the HBV and INCA-C models. TOC concentrations and color show similar dynamics with some differences. Catchments with lower open water proportion present browner waters due to lower retention times. TOC exports are well correlated to discharge in suggesting that TOC concentration is controlled by flow. However, there is a risk of increasing carbon concentrations after peaks in runoff, which are related to wet years. The INCA-C reproduces well the intra- and interannual variation in DOC concentration in Fyrisån, however, the model fails to capture some of the high peaks. Further studies, are needed in order to both understand the new trends in DOC concentration and develop the INCA-C model to predict these trends. Once the new studies based on this report are carried out successfully the model could be used to predict DOC concentrations in the future

Gridded climate data products are an alternative to instrumental measurements as inputs to rainfall–runoff models

Rainfall-runoff models are widely used to predict flows using observed (instrumental) time series of air temperature and precipitation as inputs. Poor model performance is often associated with difficulties in estimating catchment-scale meteorological variables from point observations. Readily available gridded climate products are an underutilized source of temperature and precipitation time series for rainfall-runoff modelling, which may overcome some of the performance issues associated with poor-quality instrumental data in small headwater monitoring catchments. Here we compare the performance of instrumental measured and E-OBS gridded temperature and precipitation time series as inputs in the rainfall-runoff models "PERSiST" and "HBV" for flow prediction in six small Swedish catchments. For both models and most catchments, the gridded data produced statistically better simulations than did those obtained using instrumental measurements. Despite the high correspondence between instrumental and gridded temperature, both temperature and precipitation were responsible for the difference. We conclude that (a) gridded climate products such as the E-OBS dataset could be more widely used as alternative input to rainfall-runoff models, even when instrumental measurements are available, and (b) the processing applied to gridded climate products appears to provide a more realistic approximation of small catchment-scale temperature and precipitation patterns needed for flow simulations. Further research on this issue is needed and encouraged

La física del pájaro bebedor

Se describe el comportamiento de un pájaro bebedor y también el de un pájaro solar, una variante iluminada y sin agua del pájaro original. Se proponen algunos experimentos que puedan servir para motivar a los alumnos a descubrir, siguiendo un método deductivo, las bases científicas del funcionamiento de ambos dispositivos.Palabras clave: Máquina térmica; Humedad relativa del aire.The physics of the drinking birdA drinking bird behavior is described, as well as a sun bird, a sunlight and dry variant of the previous. Several experiments are suggested to be used with students to stimulate them to discover the physics on which the behavior of both devices are based, following a deductive method.Keywords: Thermal engine; Relative humidity of air

Adsorción de plata con carbón activado de hueso de aceituna

Esta investigación trata sobre la capacidad de adsorción de plata utilizando carbón activado obtenido a partir de hueso de aceituna. La metodología fue experimental, se recolectó huesos de aceituna, que fueron tratados mediante la activación química con ácido fosfórico al 85% de concentración. Se utilizó un gramo de carbón activado seco, para un litro de solución con 5 ppm de plata sintética, luego se agitó en rolador de botellas por 3 horas, durante la prueba se obtuvo alícuotas de 20 ml cada quince minutos para analizar la concentración de plata en la solución, luego se realizó los cálculos evaluando con las isotermas de Freundlich-Kuster y Langmuir. Además, se evaluó el porcentaje de atrición. Los ensayos se realizaron por triplicado, y se hizo en paralelo con una muestra comercial de carbón activado de cáscara de coco. Los resultados muestran que la activación química del hueso de aceituna tiene una capacidad de adsorción de 3.19 mg Ag/g carbón (63.8%), recuperación de plata de 66.20% y 12.33% de atrición. Se concluye que el carbón activado de hueso de aceituna obtenido por activación química presenta capacidad de adsorción 20% debajo del obtenido con el carbón activado de la cascara de coco obtenido por activación térmica

Biomass Carbon and Nitrogen allocation in different tree species: do tree compartments and size affect C:N relationship?

Tree carbon (C) and nitrogen (N) concentrations and C:N ratio are critical for understanding the elemental compositions of forests, N use efficiency, productivity and the biogeochemical cycles. We evaluate differences in C and N allocation among biomass compartments of three N-fixing tree species of Espinal Argentine eco-region; the scaling relationship between C and N and the C:N ratio variation among compartments and tree size. Neltuma affinis (Spreng.) C.E. Hughes & G.P. Lewis, Neltuma nigra (Griseb.) C.E. Hughes & G.P. Lewis and Vachellia caven (Molina) Seigler & Ebinger plants (n = 30 for each species) were felled, grouped by stem basal diameterbased size classes and partitioned into 3 biomass compartments: stem (st), large branches (lb) and small branches + leaves, flowers and fruits (sbl). C and N concentrations were markedly influenced by species and biomass compartments. In general, sbl compartment presented more N than the st and lb, while C concentrations in Neltuma stems were the highest. Overall, no isometric C–N scaling relationships were found in different compartments. C:N variations in compartments were positively correlated with N concentrations but did not exhibit any significant association with C concentrations. C:N ratios differed significantly among species and biomass compartments. The C:N ratio for compartments ranked in an order of st > lb > sbl. C:N ratio variability in sbl was the least. Only in N. affinis and V. caven stems C:N relationship differed among tree size. Our results provide evidence of the importance of using in situ C and N concentration per main tree species and biomass compartments, to more accurate estimates of C and N stocks.Fil: Sione, Silvana Maria Jose. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Ledesma, Silvia. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Aceñolaza, Pablo Gilberto. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Wilson, Marcelo Germán. Instituto Nacional de Tecnología Agropecuaria; Argentin

Emergent dynamics of fast ripples in the epileptic hippocampus

Fast ripples are a type of transient high-frequency oscillations recorded from the epileptogenic regions of the hippocampus and the temporal cortex of epileptic humans and rodents. These events presumably reflect hypersynchronous bursting of pyramidal cells. However, the oscillatory spectral content of fast ripples varies from 250 to 800 Hz, well above the maximal firing frequency of most hippocampal pyramidal neurons. How such high-frequency oscillations are generated is therefore unclear. Here, we combine computational simulations of fast ripples with multisite and juxtacellular recordings in vivo to examine the underlying mechanisms in the hippocampus of epileptic rats. We show that populations of bursting cells firing individually at 100-400 Hz can create fast ripples according to two main firing regimes: (1) in-phase synchronous firing resulting in >pure> fast ripples characterized by single spectral peaks that reflect single-cell behavior and (2) out-of-phase firing that results in >emergent> fast ripples. Using simulations, we found that fast ripples generated under these two different regimes can be quantitatively separated by their spectral characteristics, and we took advantage of this separability to examine their dynamics in vivo.We found that in-phase firing can reach frequencies up to 300 Hz in the CA1and up to 400Hzin the dentate gyrus. The organization of out-of-phase firing is determined by firing delays between cells discharging at low frequencies. The two firing regimes compete dynamically, alternating randomly from one fast ripple event to the next, and they reflect the functional dynamic organization of the different regions of the hippocampus. Copyright © 2010 the authors.Peer Reviewe

Future changes in the Dominant Source Layer of riparian lateral water fluxes in a subhumid Mediterranean catchment

The 'Dominant Source Layer' (DSL) is defined as the riparian zone (RZ) depth stratum that contributes the most to water and solute fluxes to streams. The concept can be used to explain timing and amount of matter transferred from RZs to streams in forest headwaters. Here, we investigated the potential impact of future climate changes on the long-term position of the DSL in a subhumid Mediterranean headwater catchment. We used the rainfall-runoff model PERSiST to simulate reference (1981-2000) and future (2081-2100) stream runoff. The latter were simulated using synthetic temperature, precipitation, and inter-event length scenarios in order to simulate possible effects of changes in temperature, rainfall amount, and rainfall event frequency and intensity. Simulated stream runoff was then used to estimate RZ groundwater tables and the proportion of lateral water flux at every depth in the riparian profile; and hence the DSL. Our simulations indicated that future changes in temperature and precipitation will have a similar impact on the long-term DSL position. Nearly all scenarios projected that, together with reductions in stream runoff and water exports, the DSL will move down in the future, by as much as ca. 30 cm. Shallow organic-rich layers in the RZ will only be hydrologically activated during sporadic, large rainfall episodes predicted for the most extreme inter-event length scenarios. Consequently, terrestrial organic matter inputs to streams will decrease, likely reducing catchment organic matter exports and stream dissolved organic carbon concentrations. This study highlights the importance of identifying vertical, hydrologically active layers in the RZ for a better understanding of the potential impact of future climate on lateral water transfer and their relationship with surface water quality and carbon cycling