El estado de esfuerzos durante el Terciario en la Depresión de Arnedo (La Rioja)

La aplicación de los métodos de analisis estadisticos en microtectónica frágil a la fracturación a escala microestructural de los materiales terciarios de la Depresión de Arnedo (La Rioja) ha dado como resultado la existencia de un régimen de compresión uniaxial y desgarre con el ejeu, horizontal en dirección 000-020, que se extiende al menos hasta el Mioceno inferior (Ageniense)

El estado de esfuerzos durante el Terciario en la Depresión de Arnedo (La Rioja)

La aplicación de los métodos de analisis estadisticos en microtectónica frágil a la fracturación a escala microestructural de los materiales terciarios de la Depresión de Arnedo (La Rioja) ha dado como resultado la existencia de un régimen de compresión uniaxial y desgarre con el ejeu, horizontal en dirección 000-020, que se extiende al menos hasta el Mioceno inferior (Ageniense)

Etiología, importancia y distribución de la seca del garbanzo en el valle del Guadalquivir

La «Seca» o «Fusariosis» del garbanzo (Cicer arietinum, L.)> fue señalada por algunos autores como la enfermedad más importante del cultivo en Andalucía, atribuyéndole importantes pérdidas de cosecha. Sin embargo, el conocimiento en nuestro país sobre su etiología, epidemiología y lucha era prácticamente inexistente, salvo por investigaciones preliminares que indicaron la posibilidad de que la «Fusariosis» incluyera un complejo de enfermedades, que denominamos Marchitez y Podredumbre de Raíz (MPR). Los objetivos generales de las investigaciones incluidas en este trabajo fueron determinar la importancia y distribución de la MPR en el valle del Guadalquivir y su naturaleza etiológica y sintomatológica. Durante 1979 a 1981, se realizaron prospecciones sistemáticas en 108 campos de garbanzo en la Campiña de Córdoba y Sevilla, con un total de más de 1.300 ha., en las que se efectuaron observaciones sobre la sintomatología, incidencia y severidad de los ataques de la MPR. Plantas afectadas con los síntomas característicos se muestrearon para completar las descripciones sintomatológicas de campo y aislar en cultivo puro e identificar los posibles agentes asociados. La patogenicidad de los organismos consistentemente aislados se investigó en inoculaciones con suelo infestado artificialmente, o por inmersión de raices o cultivo de plantas, en una suspensión de inoculo. En suelo infestado con aislamiento patogénicos de Fusarium oxysporum y F. solani, se investigó lá susceptibilidad a ellos de once especies de leguminosas cultivadas, así como las diferencias en patogenicidad para varios cultivos de garbanzo. Cinco complejos sintomatología», amarilleamiento, marchitez, podredumbre seca de raíz, enanismo amarillento y clorosis, se identificaron asociados con la MPR del garbanzo. Todos ellos estuvieron uniformemente distribuidos en la campiña de Córdoba y Sevilla, siendo amarilleamiento y marchitez los más importantes. Tres especies fúngicas, F. oxysporum, F. solani y Macrophomina phaseolina, se aislaron consistentemente de plantas afectadas de los diferentes complejos sintomatológicos y resultaron patogénicos sobre garbanzo en inoculaciones artificiales. Los aislamientos de F. oxysporum fueron clasificados en tres grupos por características morfofisiológicas y patogénicas, caracterizándose, principalmente, por el tipo de síntoma que causaron: marchitez vascular, amarilleamiento vascular y amarilleamiento no vascular con lesiones necróticas corticales en el cuello y raíz. Los dos primeros grupos mostraron especificidad patogénica para garbanzo, por lo que pueden ser considerados como F. oxysporum f. sp. ciceri. La patogenicidad diferencial de ambos grupos sobre cultivares de garbanzo indica que petenecen a diferentes razas fisiológicas. F. solani causó amarilleamiento y podredumbre negra de cuello y raíz, existiendo diferencias morfofisiológicas y de patogenicidad entre aislamientos. Uno de los más virulentos fue identificado como F. eumartii. Los aislamientos de F. solani y F. eumartii resultaron patogénicos sobre garbanzo, haba (Vicia faba L.), guisante (Pisum sativum L.), lenteja (Lens escuelenta Moench.), Lupinus albus, L. angustifolius, L. luteus y L. mutabilis, por lo que rigurosamente no pueden ser caracterizados como alguna de las formas especializadas conocidas, aunque por la reacción observada parecen mejor adaptados a garbanzo, haba y guisante que a las restantes especies. M. phaseolina causó amarilleamiento y podredumbre seca de cuello y raíz. Las infecciones en inoculaciones artificiales fueron mas severas a altas temperaturas y bajo contenido de agua en el suelo, confirmando asi las observaciones de campo. Nuestros resultados señalan a F. oxysporum como agente de la marchitez y del amarilleamiento vasculares, a F. solani como agente del amarilleamiento no vascular asociado con podredumbre negra de cuello y raíz y a M. phaseolina como agente de la podredumbre seca de raíz; si bien, en el complejo amarilleamiento estuvieron implicadas las tres especies fúngicas, así como factores abióticos. Nuestras observaciones indican, asimismo, que el enanismo amarillento puede ser causado por el virus del enrollado de las hojas del guisante (PLRV), aunque otros virus pueden estar implicados, y que la clorosis resulta de una deficiencia férricaSeveral authors have considered the «Seca or fusariosis» disease as the most important disease that causes severe losses of seed yield of chickpea (Cicer arietinum L.) in Andalucía. Nevertheless, there is little knowledge of the etiology, epidemiology and control of that disease, except for some preliminary research which indicated that «Seca» might include a disease complex hereafter named Will and Root Rot (WRR). The objetives of the present study were to determine the etiology, symptomatology, importance and distribution of WRR of chickpeas in the Guadalquivir Valley (Southern Spain). Systematic disease surveys were carried out in the Cordoba and Sevilla provinces of Andalucía, including 108 chickpea fields and 1.300 ha. Observations were made on symptomatology, incidence and severity of WRR attacks. Samples of affected plants were used for further observations and isolations. Pathogenicity of the fungi which were isolated was investigated in artificially infested soil or by dipping the roots or growing plants in a inoculum suspension. Differential pathogenicity to chickpea cultivars and pathogenicity to eleven legume species were investigated in soil artificially infested with isolates of Fusarium oxysporum and F. solani. Five symptom complexes were found associated with WRR attacks: Will, Yellowing, Dry Root Rot, Yellow Stunt and Chlorosis. All symptom complexes were widely and uniformly distributed in Cordoba and Sevilla provinces, but Will and Yellowing cxcurred with higher prevalence, incidence and severity. F. oxysporum, F. solani and Macrophomina phaseolina, were consistently isolated from plants affected by the various symptom complexes. Isolates of those fungi were found to be pathogenic to chickpea in artificial inoculation experiments. Three groups of F. oxysporum isolates were distinguished according to morphological and pathogenic characteristics. Isolates of the different groups caused either vascular will, vascular yellowing, or nonvascular yellowing along with cortical necrotic lesions of collar and root. Isolates inducing vascular wilt or yellowing showed pathogenic specialization to chickpea and may be consideres as F. oxysporum f. sp. ciceri. Those isolates also showed differential pathogenicity to chickpea cultivars, indicating that they belong to different pathogenic races. Isolates of F. solani induced foliar yellowing and black collar and root rot, but differed in morpho-physiological characteristics and virulence. One of the most virulent isolates of F. solani induced foliar yellowing and black collar and root rot, but differed in morpho-physiological characteristics and virulence. One of the most virulent isolates of F. solani was further identified as F. eumartii. Isolates of F. solani and F. eumartii were pathogenic to chickpea, faba bean (Vicia faba L.). pea (Pisum sativum L.), lentil (Lens esculenta Moench), Lupinus albus L., L. angustifolius L., L. luteus L. and L. mutabilis Sweet., and therefore cannot be considered as belonging to any of the known formae speciales of F. solani. Nevertheless, as indicated by the severity of disease reactions observed, those isolates seem to be more adapted to chickpea, faba bean and pea than to any of the other species. M. phaseolina induced yellowing and dry collar and root rot. Infections by this pathogen in artificial inoculations were most severe at high temperatures and low soil water content, thus confirming field observations on incidence and severity of the disease. Our results indicate that F. oxysporum, F. solani and M. phaseolina are, respectively, the agents of Vascular Will and Yellowing, Non-Vascular Yellowing and Black Collar and Root Rot, and Dry Root Rot, However, those three species as well as abiotic factors were involved in the etiology of the Yellowing symptom complex in the field. Also, our observations in the field indicate that the Chlorosis complex is due to an iron deficiency, and that the Yellow Stunt symptom complex might be induced by pea leaf roll virus, although other plants viruses could be involved as well

Perkinsosis in molluscs: A review

The genus Perkinsus includes protistan parasites infecting marine molluscs throughout the world, some of which are associated with mass mortalities. Life cycle involves vegetative proliferation within the host, by which a cell named trophozoite undergoes successive bipartitioning. Other stages have been observed in vitro or in vivo, depending on the species: hypnospore, zoosporangium and zoospore. Molecular taxonomy supports a close affinity between dinoflagellates and Perkinsus spp. Six species of Perkinsus are currently considered valid: P. marinus, P. olseni, P. qugwadi, P. chesapeaki, P. andrewsi and P. mediterraneus. Histology and, above all, incubation of host tissues in Ray’s fluid thioglycollate medium (RFTM) are classic diagnostic methods. In addition, more sensitive and quicker molecular diagnostic techniques based on either immunoassays or PCR have been developed for Perkinsus spp. Epizootiological studies have shown a marked influence of water temperature and salinity on P. marinus infection in oysters Crassostrea virginica, thus determining parasite geographical range and temporal disease dynamics (seasonality). In vitro cultures have been established for four Perkinsus spp. Immune response to infection varies depending on host and involves phagocytosis or encapsulation of the parasite cells by host haemocytes. A polypeptide is secreted by clam Tapes philippinarum haemocytes that could kill the parasite. In vitro cultured P. marinus cells secrete proteases that are likely involved in degradation of host tissues. P. marinus can suppress the toxic oxygen radicals produced by host haemocytes. In addition to host death, sublethal effects caused by Perkinsus spp. (reduction of fecundity, growth, and condition) may have significant ecological and economic implications. Various strategies have been assayed to mitigate the consequences of P. marinus epizootics on the oyster industry: modifications of management/culture procedures, selective breeding to obtain resistant oyster strains, and the use of triploid oysters and allochthonous oyster species. Some chemotherapeutants have been proved to inhibit or kill parasite cells in vitro

Alteraciones fisarias tras radiación láser

Ante el auge actual de la radiación láser y al no encontrar bibliografía referente al posible efecto sobre el cartílago de crecimiento, hemos decidido hacer una valoración del mismo en un modelo experimental. Se utilizaron 50 ratas, estableciéndose cinco grupos de estudio de 10 animales cada uno, dependiendo de la dosis de radiación aplicada percutáneamente sobre la fisis femoral distal. Tras el estudio ultraestructural, histoquímico y morfométrico, hemos observado una serie de alteraciones indicadoras de un daño celular directo. Los hallazgos permiten concluir que este tipo de radiación está contraindicado absolutamente durante la fase de crecimiento óseo o en el esqueleto inmaduro.In view of the present importance of Laser Radiation, and due to the lack of references about its effects on the growth cartilage, we designed an experimental model in order to asses it. A total of 50 rats were used, establishing five groups of study at 10 animals each, depending on the dosis of radiation applied percutaneously on the distal femoral phisys. After the structural, histochemical and morphometric study, we observed a series of alterations indicating a direct celular damage at the physion. From the results, it is concluded that laser radiation should be on absolute contraindication during the phase of bone growth or in the inmature skeleton

Seasonal succession of phytoplankton species on the coast of A Coruña (Galicia, northwest Spain)

Phytoplankton species composition was monitored monthly at two stations on the continental shelf off A Coruña (Galicia, northwest Spain). The deeper station (80 m) was sampled between May 1989 and December 1992. The coastal station (20 m) was studied during 1992. In each sampling, water samples were taken from selected depths throughout the water column. Microflagellates formed the bulk of phytoplankton, being dominant all year long, followed by diatoms, which dominated during phytoplankton blooms. The samples studied were arranged into five groups, according to environmental conditions defined for the main oceanographic periods in the area. Each group showed a characteristic phytoplankton species composition. The most important phytoplankton blooms occurred during spring and autumn. However, major phytoplankton abundances were also detected during upwelling events in the summer. Several species of the genus Chaetoceros, especially C. socialis (Lauder, 1864) were dominant during blooms, and accompanying species, e.g. Lauderia borealis (Gran, 1900), were important during spring and autumn. Leptocylindrus danicus (Cleve, 1889) made a major contribution to phytoplankton abundance during summer upwelling events. In contrast with studies conducted in neighbouring areas, dinoflagellates never dominated during summer stratification periods, probably because of the very frequent upwelling events, which caused destabilisation of the water column. During winter mixing and in deeper waters, we found a mixed community comprising species that are present throughout the year, but in very low densities, as well as resuspended diatoms from sediment. In 1992, at the coastal station, red-tide events occurred, and some species of dinoflagellates (e.g. Gymnodinium catenatum Graham, 1943) reached densities of well over 100 cells ml⁻¹. Considering the entire series of observations, the most noteworthy features are a decrease in the magnitude of diatom blooms during the study period and, on the contrary, an increase in the abundance of microflagellates.Se estudia la composición de especies y grupos taxonómicos de fitoplancton con una frecuencia aproximadamente mensual en dos estaciones de la plataforma continental frente a A Coruña (Galicia, noroeste de España). La estación más profunda (80 m) fue muestreada entre mayo de 1989 y diciembre de 1992. La estación costera (20 m) fue estudiada durante 1992. En cada muestreo se recogieron muestras repartidas por toda la columna de agua. El grupo de fitoplancton más numeroso fue el de los microflagelados, siempre dominantes en todas las épocas del año, seguido de las diatomeas, responsables de las principales proliferaciones de fitoplancton registradas. Las observaciones se clasificaron en cinco grupos según las características ambientales definidas para los principales periodos oceanográficos de esta zona. Cada uno de estos grupos presentó una composición de especies de fitoplancton característica. Las mayores proliferaciones de fitoplancton se produjeron en primavera y otoño, pero también se registraron elevadas abundancias durante episodios de afloramiento en verano. Varias especies del género Chaetoceros, especialmente C. socialis (Lauder, 1864), fueron las principales responsables de estas proliferaciones, acompañadas de otras especies de diatomeas como Lauderia borealis (Gran, 1900) en primavera y otoño, y Leptocylindrus danicus (Cleve, 1889) en el afloramiento de verano. A diferencia de lo encontrado en otras zonas próximas, los dinoflagelados no llegan a hacerse dominantes en el periodo de estratificación térmica de verano, probablemente debido a la frecuencia de los episodios de afloramiento. Durante el periodo de mezcla invernal y en las capas profundas de la columna de agua se encuentra una mezcla de especies presentes todo el año, aunque con bajas abundancias, y también diatomeas del sedimento resuspendidas. En 1992, especialmente en la estación costera, se produjeron episodios de marea roja durante el verano, superando algunas especies de dinoflagelados (como Gymnodinium catenatum Graham, 1943) 100 células ml⁻¹. Considerando toda la serie de observaciones, se aprecia una disminución en la magnitud de las proliferaciones de diatomeas y un incremento en la abundancia de microflagelados en los últimos años.Instituto Español de Oceanografí

Influence of décollement-cover thickness variations in fold-and-thrust belts: Insights from centrifuge analog modeling

Centrifuge analog modeling incorporating thickness variations of décollement and overlying sedimentary cover is used to study thrust-wedge evolution on salt-detached contractional systems involving tapered sedimentary cover. From simpler, layer-cake to 3D tapered décollement-cover sequences, our models constrain wedge evolution: a more advanced front, where the cover is thicker, promotes differential frontal translation and triggers vertical axis rotation of several hinterland anticlines which appear towards the thinner cover area. In all cases, the décollement level is strongly sheared and tends to migrate laterally toward the thinner cover areas. Models are compared with previous analog models under normal gravity and the natural example of the South Pyrenean Central salient. All in all, we conclude that a 3D tapered décollement-cover basin architecture, as a sole factor, can determine the formation of a thrust salient formed by increasing structural curvature (progressive arc)

Kinetics of wet peroxide oxidation of phenol with a gold/activated carbon catalyst

Gold nanoparticles supported on activated carbon (Au/AC) have been tested in catalytic wet peroxide oxidation using phenol as target pollutant. In the current work, the effect of several operating conditions, including initial pH (3.5–10.5), catalyst load (0–6 g/L), initial phenol concentration (0.1–5 g/L), hydrogen peroxide dose (4–100% of the theoretical stoichiometric amount) and reaction temperature (50–80 °C) has been investigated. The results show that the Au/AC catalyst would be useful at relatively high pollutant to catalyst ratios (at least 0.4 w/w) and it can work efficiently within a wide range of pH (3.5–7.5). The catalyst suffers rapid deactivation but its activity can be completely restored by an oxidative thermal treatment at low temperature (200 °C). A kinetic model is presented, capable of describing the experimental results. This model is based on a rate equation of order one for hydrogen peroxide consumption and two for phenol oxidation and includes the catalyst deactivation and its temperature dependenceThe authors wish to thank the Spanish MICINN for the financial support through the projects CTQ2008-03988/PPQ and CTQ2010-14807. The Comunidad Autónoma de Madrid is also gratefully acknowledged for the financial support through the project S2009/AMB-158

The carriers of AMS in remagnetized carbonates. Insights for remagnetization mechanism and basin evolution

Magnetic fabrics are usually studied to unravel the evolution of sedimentary basins, mainly focusing the attention in paramagnetic minerals. However, since basins are sometimes affected by burial-related chemical remagnetizations, magnetic fabrics can also be carried by authigenic ferromagnetic minerals related to remagnetization processes. Consequently, the study of the different types of fabrics can give complementary and valuable information about the evolution of sedimentary basins. Here, we explore, in the Jurassic carbonates of the Central High Atlas (Morocco), the role in magnetic fabrics of authigenic magnetite that grew during the Cretaceous (ca. 100 Ma) widespread remagnetization event. Magnetic fabrics are studied in 53 sites using the anisotropy of the magnetic susceptibility measured at room temperature (RT-AMS) and comparing results with sub-fabrics that alternatively enhance the paramagnetic and the ferromagnetic signal. Furthermore, an innovative analysis is proposed, comparing the magnetic fabrics before and after bedding correction (the common procedure) with fabric orientation after partial bedding correction. We use the paleomagnetic information to reconstruct the attitude of bedding at the remagnetization time and to restore the magnetic fabrics at this time. The performed analysis allows interpreting RT-AMS in terms of the contribution of different subfabrics, and the relationship between these, tectonic processes and the magnetic mineralogy. Four RT-AMS types are defined: T1 is carried by superparamagnetic magnetite that grew during the remagnetization stage and shows a horizontal lineation parallel to the extension direction at this time; T3 and T4 are carried by paramagnetic minerals and show compressive fabrics with the magnetic lineation parallel to intersection (bedding-cleavage) lineation; finally, T2 shows a mix between ferrimagnetic and paramagnetic fabrics.MINECO (Spanish Ministry of Economy and Competitiveness) cofinanced by the ERDF (European Union) (research projects CGL2012-38481 and CGL2016-77560)

Improved wet peroxide oxidation strategies for the treatment of chlorophenols

Different advanced oxidation strategies have been investigated for the treatment of chlorophenols in aqueous phase with the aim of improving the removal efficiency in terms of mineralization, remanent by-products and kinetics. Those strategies were homogeneous Fenton-like oxidation and CWPO with two different own-prepared FexOy/γ-Al2O3 catalysts. The intensification of the process by increasing the temperature has been also evaluated. CWPO of chlorophenols with those catalysts has proved to be more efficient than homogeneous Fenton-like oxidation due to a lower rate of H2O2 decomposition allowing a higher availability of hydroxyl radicals along the course of reaction. Increasing the temperature clearly improved the oxidation rate and mineralization degree of both homogeneous Fenton-like oxidation and CWPO, achieving almost 90% TOC reduction after 1h at stoichiometric H2O2 dose, 100mgL-1 initial chlorophenol concentration, 1gL-1 Fe3O4/γ-Al2O3 catalyst, pH 3 and 90°C temperature. Both FexOy/γ-Al2O3 catalysts suffered fairly low iron leaching (<5%) and a remarkable stability in a three-cycles test with 2,4,6-TCP. The use of the magnetic catalyst is preferable due to its easy separation and recovery from the liquid phase by a magnet. Its magnetic properties remained unchanged after use in CWPOThis research has been supported by the Spanish MICINN through the projects CTQ2008-03988 and CTQ2010-14807 and by the CM through the project S-2009/AMB-1588. M. Munoz thanks the Spanish Ministry of Education for a FPU research gran