354 research outputs found
Antiguas explotaciones de estaño-wolframio en Arteixo y Laracha (resumen)
[Resumen] En los términos municipales de Arteixo y Laracha se conocen
una serie de pequeñas explotaciones sobre yacimientos de
wolframita-casiterita, de escaso interés tomándolos por separados,
pero con importancia potencial en su conjunto. Todos estos
yacimientos fueron trabajados de forma muy rudimentaria entre los años 1940 a 1968, fecha en que cerró la última mina de la zona. El único estudio conocido sobre alguno de estos yacimientos corresponde a uno realizado por el Instituto Geológico y Minero, que investigó por medio de prospección geoquímica para Sn-W en la zona de Monteagudo-Lendo, clasificando la zona de Laracha como de interés medio a escaso para estas sustancias
Germinación de conidios de Botryosphaeria dothidea Mough.: Fr (Ces. & De Not.) y alteraciones histológicas en tallos de pitahaya (Hylocereus undatus) (Haworth) Britton & Rose
Conidial germination of Botryosphaeria
dothidea (anamorph: Fusicoccum) in sterile
distilled water and 1% sterile dextrose solution
was evaluated at 4, 6, 12, 24 and 36 h after
incubation. Also, it was described the anatomical
changes on pitahaya stems induced by this
fungus, collected in the field and artificially
inoculated in the laboratory. Conidial germination
was less than 30% in water and it was improved
when 1% dextrose was added to the water.
In 1% dextrose solution the germination was
90% after 4h of incubation and 100% at 6 h.
Pathogen germ tubes had entered through
wounds and sometimes through stomata and
hyphae colonized intra and intercellularly in
the parenchyma-chlorenchyma tissues. On
naturally and artificially diseased stems the
main alterations were: destruction of cuticle,
hyperplasia of epidermal and collenchymatous
hypodermal cells and conform the advance
of the pathogen a layer of lignified periderm
was formed surrounding the damaged tissues;
however, it couldn't stop the advance of the
pathogen and the cells that surrounded the
lesion suffered necrosis.Se evaluó la germinación de conidios
de Botryosphaeria dothidea (anamorfo:
Fusicoccum) en agua destilada estéril y en una
solución de dextrosa 1% a las 4, 6, 12, 24 y
36 h de incubación. También, se describieron
los cambios anatómicos en tallos de pitahaya
inducidos por este hongo, tanto aquellos
naturalmente infectados en campo como
inoculados artificialmente en laboratorio. La
germinación de conidios en agua estéril solo
alcanzó el 30%, mientras que la adición de
dextrosa al 1% mejoró la germinación. En una
solución de dextrosa al 1% la germinación a las
4 h fue de 90% y del 100% a las 6 h. Los tubos
germinativos del hongo penetraron a través de las
heridas y algunas veces a través de los estomas
y se multiplicaron inter e intracelularmente en
los tejidos del parénquima-clorénquima. En
tallos enfermos natural y artificialmente, las
principales alteraciones fueron: destrucción de la
cutícula, hiperplasia de las células epidermales
e hipodermales colenquimatosas. Conforme
el avance del patógeno se formó una capa
de peridermis lignificada que rodeó el tejido
dañado; sin embargo, no se detuvo el avance
del patógeno y las células que rodeaban la lesión
se necrosaron.Fil: Valencia-Botín, Alberto J..
Universidad de Guadalajara (México)Fil: Cisneros-López, María E..Fil: Ruíz-Sánchez, Esaú.
Instituto Tecnológico de Conkal (México
Germinación de conidios de Botryosphaeria dothidea Mough.: Fr (Ces. & De Not.) y alteraciones histológicas en tallos de pitahaya (Hylocereus undatus) (Haworth) Britton & Rose
Conidial germination of Botryosphaeria dothidea (anamorph: Fusicoccum) in sterile distilled water and 1% sterile dextrose solutionwas evaluated at 4, 6, 12, 24 and 36 h after incubation. Also, it was described the anatomical changes on pitahaya stems induced by this fungus, collected in the field and artificially inoculated in the laboratory. Conidial germination was less than 30% in water and it was improved when 1% dextrose was added to the water. In 1% dextrose solution the germination was 90% after 4h of incubation and 100% at 6 h. Pathogen germ tubes had entered through wounds and sometimes through stomata and hyphae colonized intra and intercellularly in the parenchyma-chlorenchyma tissues. On naturally and artificially diseased stems the main alterations were: destruction of cuticle, hyperplasia of epidermal and collenchymatous hypodermal cells and conform the advance of the pathogen a layer of lignified periderm was formed surrounding the damaged tissues; however, it couldn't stop the advance of the pathogen and the cells that surrounded the lesion suffered necrosis.Conidial germination of Botryosphaeria dothidea (anamorph: Fusicoccum) in sterile distilled water and 1% sterile dextrose solutionwas evaluated at 4, 6, 12, 24 and 36 h after incubation. Also, it was described the anatomical changes on pitahaya stems induced by this fungus, collected in the field and artificially inoculated in the laboratory. Conidial germination was less than 30% in water and it was improved when 1% dextrose was added to the water. In 1% dextrose solution the germination was 90% after 4h of incubation and 100% at 6 h. Pathogen germ tubes had entered through wounds and sometimes through stomata and hyphae colonized intra and intercellularly in the parenchyma-chlorenchyma tissues. On naturally and artificially diseased stems the main alterations were: destruction of cuticle, hyperplasia of epidermal and collenchymatous hypodermal cells and conform the advance of the pathogen a layer of lignified periderm was formed surrounding the damaged tissues; however, it couldn't stop the advance of the pathogen and the cells that surrounded the lesion suffered necrosis
Optimization in the production of fat for the obtainment of biodiesel from sludge from treatment plants wastewater
Motivation: Most of the energy sources currently used is derived from fossil fuels, whose reserves are limited. On the other hand, millions of tonnes of waste are generated worldwide from urban water treatment. Sewerage water is treated in wastewater treatment plants (WWTP) and passed through a depuration process that generates a waste in form of sludge. In an attempt to solve those two problems we are using a strategy which involve the nematode Caenorhabditis elegans. C. elegans is a free-living nematode used as a model organism for basic biological research. Its successful as model organism for biomedical research relay in several features: it is easy to manipulate, it has a small size, a fast life cycle, a small genome and a simple anatomy. Among other traits, the ability of generating and accumulating fat and the wide range of bacteria in its diet are remarkable for this project. The general aim of this research project is to optimize the production of nematode fat useful for biodiesel, using the sludge from water depuration plant as medium to growth the nematodes. During the develop of this project, three fundamental bottlenecks have been detected: first, the sludge is not completely assimilated by the nematodes. Second, each sludge sample is diverse and generates diverse nematode production and third, In regular medium is necessary to add seven fundamental components (NaCl, KH2PO4, cholesterol, Potassium citrate, Trace Metals, CaCl2, MgSO4) to have an optimal growth of C. elegans, which is an important economical-cost.Methods: To overcome those problems, we have studied the effect of applying to the sludge a pretreatment and we are analyzing which of the components can be eliminated without affecting population growth. We also will analyze the amount of fat produced by the nematode with the Soxhlet method.Results: The following results were obtained: Microwave pretreatment increase the number of the nematode in the sludge. Addition of NaCl, KH2PO4 and Potassium citrate generates a similar nematode growth than the addition of seven components.Conclusions: We observed that it is necessary the addition of the NaCl, KH2PO4 and Potassium citrate to get an optimal growth of C.elegans in the sludge and microwave treatment generate an increase of nematode production in the sludge
Notas sobre flora y vegetación en el sector oriental del Sistema Central
Este trabajo contiene un total de 107 citas recogidas en el macizo de Ayilón y zonas próximas, acompañadas por una síntesis de la información previa disponible acerca de cada especie en la zona y por referencias mesológicas básicas de cada emplazamiento. En la segunda parte se incluye una descripción botánica de la l1arnada Acebeda de Becerril, ubicada en el monte núm. 64 del CUP de Segovia
Modelo de decisión para determinar fuentes de retorno, incentivos y capacidad en un sistema de remanufactura
This research proposes a decision model to manage the purchase of new and used components in a re-manufacturing system. New components are purchased from a supplier who offers discounts based on the reserved capacity. The used components comes from various sources, where the quantity to be received from each source depends on the incentive provided. The model considers two stochastic elements: the return level per source (for used components) and the possibility that the shipment of new components is not received. A sensitivity analysis is performed based on a numerical example. The results demonstrate significant relationships between the costs to operate the return sources, the probability of low returns, and the incentive levels assigned to each source. The experiments also indicate how the incentives and the reserved capacity depends on the probability that the new components are not received.Esta investigación propone un modelo de decisión para gestionar la compra de componentes nuevos y usados en un sistema de manufactura. Los componentes nuevos se adquieren de un proveedor el cual ofrece descuentos que dependen de la capacidad reservada. Los componentes usados provienen de varias fuentes, donde la cantidad que se recibirá de cada fuente depende del incentivo suministrado. El modelo considera dos elementos estocásticos, el nivel de retorno por fuente (para componentes usados) y la posibilidad de que no se reciba el envío del proveedor de componentes nuevos. Se realiza un análisis de sensibilidad basándose en un ejemplo numérico. Los resultados demuestran relaciones significativas entre los costos de operación de las fuentes de retorno, la probabilidad de retornos bajos y el número de fuentes usados, y el nivel de incentivo asignado por fuente. Los experimentos también indican como los incentivos y la capacidad reservada dependen de la probabilidad de que no se reciban las unidades nuevas. La aplicación en la práctica del modelo y de los resultados apoyaría a que las empresas con sistemas de remanufactura de componentes seleccionen el mejor nivel de incentivos a ofrecer, determinar su capacidad y decidir cuales fuentes de retornos usar de manera minimicen sus costos totales
Synergic Effect of Metal and Fluorine Doping on the Structural and Electrical Properties of La5.4MoO11.1-Based Materials.
Cationic and anionic frameworks of La5.4MoO11.1 proton
conductors have been modified by means of metal (Ti4+, Zr4+, and Nb5+) and
fluorine (F−) doping. This synergic effect leads to the stabilization of highsymmetry
and single-phase polymorphs. The materials have been fully
characterized by structural techniques, such as X-ray and neutron powder
diffraction and transmission electron microscopy. The fluorine content was
determined by ion chromatography. Impedance spectroscopy analysis under
different atmospheres (dry and wet N2 and O2 and wet 5% H2−Ar) showed
an improvement in the electronic conductivity under reducing conditions,
making these materials potential candidates for hydrogen separation
membranes
Pierre Duhem and scientific truth: contextual, partial and real
Mariano Artigas understood scientific truth as real, but at the same time contextual and partial. Artigas shared some research interests and a general outlook with Pierre Duhem. We summarize the evaluation of Duhem’s thought by relevant authors and demonstrate how the way Artigas understood scientific truth in actual scientific research offers a suitable framework for capturing the realism towards which Duhem tended. This reading of Duhem runs counter to tendencies of the philosophy of science in Duhem’s time which employed expressions that sometimes framed him as a conventionalist
Scanning Electron Microscope Study of Wohlfahrtia magnifica (Schiner, 1862) (Diptera: Sarcophagidae) I. Structures with Parasitic and Possible Taxonomic Meaning
The larval development of Wohlfahrtia magnifica (the most important dipteran causing sheep myiasis in the Palearctic region) has been studied by means of scanning electron microscopy. The ultrastructure of mouth-hooks, oral ridges, labial lobes, body spines and anterior and posterior peritremes is described for the first time. Their possible adaptations to a parasitic lifeway are also discussed. Thus, the use of new structures in the Sarcophagidae taxonomy is proposed from the point of view of their ultrastructure and adaptative morphology
- …