A biogeochemical model for North and Northwest Iberia: some applications

The Coastal and Ocean modeling group at the Spanish Institute of Oceanography (IEO) has a broad experience in hydrodynamic modeling with ROMS in the area of West and North Iberia. Our main task consists of providing insight on the coastal and ocean dynamics in support to the intense IEO ecosystem and fisheries research in the area. The NW coast of Iberia is characterized by high levels of primary production that result from relatively frequent and intense inputs of nutrients caused by upwelling, especially in spring and summer. Primary production sustains wealthy fisheries and aquaculture industries, which constitute a prime economic activity in the region. As a first approach to understand the ecosystem variability in the area we focused on the spring bloom. A high resolution (~3 km) configuration of the ROMS physical model with atmospheric forcing coming from the regional agency Meteogalicia (http://www.meteogalicia.es), which has shown to represent the main features of the shelf and slope circulation in the area, was run coupled to the Fasham-type Fennel biogeochemical model (N2PZD2). Any biogeochemical model aimed at providing a reliable representation of the dynamics of a certain area should be tuned according to its characteristics. In an upwelling system, the composition of phytoplankton varies from the beginning to the end of the bloom. When nutrients and irradiance are high, diatoms are the dominant group, whereas flagellates become more important when upwelling relaxes and, consequently, nutrients and light intensity decrease. In the NW Iberian coast, it has been found that Chaetoceros socialis is the dominant diatom species during the spring bloom (Bode et al, 1996, 1998). For this reason, we have decided to use parameters that are characteristic of plankton at the spring bloom. In particular, the parameters of Chaetoceros socialis have been considered for the unique phytoplankton class of the model. We will show comparisons of the model results for 2006 and 2007 with observations at weekly and daily time scales (MODIS chlorophyll-a images, in situ observations from the “Instituto Español de Oceanografía” Pelacus cruises). The spring bloom is reasonably reproduced in the NW and N coasts in time, space and intensity. The variability between the primary production in 2006 and 2007 can be related to the oceanographic conditions thanks to the use of a numerical model. The results are promising and encourage us to move forward to increase the complexity of our models and broaden their range of application. We will show some examples of the use of the IEO models to get some insight on sardine recruitment variability and harmful algal bloom prediction

The IEO coastal observatory: understanding variability of coastal circulation and ecosystem response off North and North West Iberia

ATLANTOS; GAI

Modeling Iberian sardine Early Life Stages dynamics

The Iberian sardine (Sardina pilchardus) constitutes a traditional target species in western Iberia that remains to be economically important in Portugal and, to a lesser extent, in Galicia (NW Spain). The time series of recruitment shows ups and downs in the last decades. According to the ICES Advice 2013 for regions VIII and IXa, the biomass of age 1 sardine and older has decreased since 2006 and recruitment has been below the long term average since 2005. In order to understand these fluctuations, a Lagrangian model to simulate sardine Early Life Stages (ELS), this is, egg and larvae stages, has been set up. The results of a high resolution hydrodynamic model for North and Northwest Iberia have been used as an input of the Lagrangian model Ichthyop (Lett et al., (2008)) to simulate ELS advection and dispersion. Ichthyop has been adapted to sardine by including some biological behavior. A biogeochemical model coupled to the hydrodynamic model was also used to get some insight on recruitment for years 2006 2007

Episodic synchronization in dynamically driven neurons

We examine the response of type II excitable neurons to trains of synaptic pulses, as a function of the pulse frequency and amplitude. We show that the resonant behavior characteristic of type II excitability, already described for harmonic inputs, is also present for pulsed inputs. With this in mind, we study the response of neurons to pulsed input trains whose frequency varies continuously in time, and observe that the receiving neuron synchronizes episodically to the input pulses, whenever the pulse frequency lies within the neuron's locking range. We propose this behavior as a mechanism of rate-code detection in neuronal populations. The results are obtained both in numerical simulations of the Morris-Lecar model and in an electronic implementation of the FitzHugh-Nagumo system, evidencing the robustness of the phenomenon.Comment: 7 pages, 8 figure

Effect of Abiotic Climatic Factors on the Gonadal Maturation of the Biocontrol Agent Sphaerophoria rueppellii (Wiedemann, 1830) (Diptera: Syrphidae)

The hoverfly Sphaerophoria rueppellii is currently one of the most effective predators commercially available for aphid pest control. However, knowledge of the reproductive system of males and females of this syrphid is limited. The present article aims to report how changes in the temperature and photoperiod may affect development of the gonads (ovaries and testes), oviposition, and fecundity during the lifespan of S. rueppellii. Four environmental conditions (14L:10D, T: 20 ± 1 °C; 12L:12D, T: 20 ± 1 °C; 14L:10D, T: 25 ± 1 °C; and 12L:12D, T: 25 ± 1 °C) were used to determine oviposition, hatching percentage, and lifespan during a period of 30 days after the adult emergence. The maturation of the ovaries was done under three treatments (barley leaves with aphids always available; barley leaves two days per week with aphids available; no barley leaves available), and in the same environmental conditions noted above. Males at 14L:10D, 20 ± 1 °C; and 14L:10D, 25 ± 1 °C; were used to analyze and study the maturation of the testes. Females at 14L:10D; T: 25 ± 1 °C showed a significant difference in oviposition, percentage of hatching, and rate of eggs. A detailed description of the male and female gonads was undertaken, and it was determined that the conditions in which males sexually mature early are at 14L:10D, 25 ± 1 °C. These results will improve the application of S. rueppellii in crops, for the control of aphid pests

Investigation of Coulomb dipole polarization effects on reactions involving exotic nuclei

We have analyzed elastic scattering angular distributions and total reaction cross sections of the exotic nuclei Li9,11 on Pb208, at energies below and above the Coulomb barrier. For this purpose, we have used an optical potential with no adjustable parameters, composed by the nuclear São Paulo potential, derived from the nonlocal nature of the interaction, and the Coulomb dipole polarization potential, derived from the semiclassical theory of Coulomb excitation. Within this formalism, we identified an unusual long-range absorption for the Li11+Pb208 system, which is dominated by the Coulomb interaction. We compare it to the absorption mechanisms observed for He6+Pb208 which, unlike those of Li11+Pb208, take place at small interacting distances, where both Coulomb and nuclear interactions are important. The proposed approach shows to be a fundamental basis to study reactions involving exotic nuclei

Modelling the hydrodynamic conditions associated with Dinophysis blooms in Galicia (NW Spain)

The northwestern Iberian coast (Galician Rías and shelf) is frequently affected by toxic harmful algal blooms (HABs) (mainly Dinophysis spp.), leading to lengthy harvesting closures in a region where aquaculture has a strong socioeconomic impact. The project ASIMUTH (http://www.asimuth.eu) aimed to develop forecasting capabilities to warn of impending HABs along the European Atlantic coast. Simulations with the ROMS model (hydrodynamical and ecological simulations complemented with Lagrangian particle tracking simulations) of the Galician coastal circulation have been performed in the framework of the ASIMUTH project to characterize and forecast oceanographic conditions before and during HAB periods. In this work, we present the Galician ASIMUTH forecast system and demonstrate its skill in predicting HAB transport and its usefulness to provide assessment for the management of the areas affected by toxic outbreaks. Experience gained during DSP events in 2005 and 2013 is shown. We also describe the Galician pilot HAB bulletins, aimed at distributing forecasts of HAB events that might induce closures of harvesting areas or, when the areas are already closed, at giving information on forthcoming oceanographic conditions that could favour or hamper the opening of an area. Our results show that the model forecasts and the bulletins can provide early warning of the risk of Dinophysis spp. events and the risk of closures linked to the presence of DSP toxins above regulatory levels in harvesting areas.Versión del editor3,083

Numerical simulations with the ASIMUTH forecast system for understanding and forecasting HAB events in Galicia (NW Spain)

Simulations with the model ROMS (hydrodynamical and ecological simulations complemented with Lagrangian particle-tracking simulations) have been performed in the framework of the project ASIMUTH (http://www.asimuth.eu) which aims to develop forecasting capabilities to warn of impending harmful algal blooms (HABs) along the European Atlantic coast. In this contribution, we will report on the skill of the ASIMUTH forecast system in predicting transport of HABs and in assessing the area affected by HABs in the upwelling-influenced Galician rias (NW Spain) with the experience gained in years 2013 and 2014.ASIMUTH FP7/26186

Osteomielitis subaguda en paciente con diabetes mellitus complicada

La osteomielitis subaguda es una infección hematógena del hueso definida como una forma de osteomielitis no supurativa esclerosante que habitualmente pasa desapercibida en estadios precoces dada su clínica insidiosa caracterizada por buen estado del paciente, así como una historia de dolor de larga evolución.Presentamos un caso de osteomielitis subaguda que, por la edad de presentación, la patología asociada del paciente y la localización de la misma, debe hacer replantearnos las distintas opciones de tratamiento asumiendo las posibles complicaciones y fracasos.Subacute osteomyelitis is a haematogenous infection of bone defined as a non-suppurative, sclerosing form of osteomyelitis which usually escapes detection in its early stages because of its insidious clinical features (good general condition of the patient and a long-lasting history of pain). We report one case of subacute osteomyelitis which, because of its location, the age at presentation and the patient's associated pathology should prompt consideration of the various therapeutic options and assumption of the possible complications and therapeutic failures

Protein delivery based on uncoated and chitosan-coated mesoporous silicon microparticles

Mesoporous silicon is a biocompatible, biodegradable material that is receiving increased attention for pharmaceutical applications due to its extensive specific surface. This feature enables to load a variety of drugs in mesoporous silicon devices by simple adsorption-based procedures. In this work, we have addressed the fabrication and characterization of two new mesoporous silicon devices prepared by electrochemistry and intended for protein delivery, namely: (i) mesoporous silicon microparticles and (ii) chitosan-coated mesoporous silicon microparticles. Both carriers were investigated for their capacity to load a therapeutic protein (insulin) and a model antigen (bovine serum albumin) by adsorption. Our results show that mesoporous silicon microparticles prepared by electrochemical methods present moderate affinity for insulin and high affinity for albumin. However, mesoporous silicon presents an extensive capacity to load both proteins, leading to systems were protein could represent the major mass fraction of the formulation. The possibility to form a chitosan coating on the microparticles surface was confirmed both qualitatively by atomic force microscopy and quantitatively by a colorimetric method. Mesoporous silicon microparticles with mean pore size of 35 nm released the loaded insulin quickly, but not instantaneously. This profile could be slowed to a certain extent by the chitosan coating modification. With their high protein loading, their capacity to provide a controlled release of insulin over a period of 60-90 min, and the potential mucoadhesive effect of the chitosan coating, these composite devices comprise several features that render them interesting candidates as transmucosal protein delivery systems