El campo filoniano de El Hoyo de Mestanza (Ciudad Real). Sobre el origen de las mineralizaciones B.G.P.C. asociadas con zonas de cizalla

RESUMEN: El campo filoniano de El Hoyo de Mestanza, situado en una zona tradicionalmente minera, está constituido por un conjunto de filones de cuarzo que contienen esfalerita, galena, pirita y calcopirita. Estos filones llevan una dirección muy constante ???-ESE, la que es coincidente con la dirección hercínica principal. Encajan en un sinclinal formado por materiales ordovícicos que se apoyan discordantes sobre la monótona serie del Precámbrico alto conocida con el nombre de «Alcudiense». Los filones de El Hoyo presentan una serie de características muy peculiares que le distinguen de los otros yacimientos existentes en la zona. No se trata de simples diques de cuarzo con sulfur os, sino de partes de la roca que han sufrido una intensa cataclasis, milonitización y silicificación, que presentan frecuentemente aspecto fluidal y caótico, boudinamientos y contactos muy irregulares generalmente poco marcados. Estos cuerpos están claramente controlados por los caracteres litológicos y estructurales de la formación Estratos Pochico, situados difectamente encima de la potente Cuarcita Armoricana. Tanto es así, que cuando los cuerpos mineralizados entran en las formaciones supra o infrayacentes, desaparecen rápidamente. A partir de las observaciones de campo y laboratorio, se puede afirmar que estos cuerpos se formaron y fueron tectonizados durante la primera fase de la deformación hercínica que es la principal en esta zona; razón por la cual, estas mineralizaciones no pueden relacionarse tal como se venía haciendo hasta ahora, con las intrusiones graníticas de Sierra Morena, ya que estas son posteriores a dicha fase. Por ello, teniendo en cuenta que los filones del Hoyo de Mestanza se encuentran siempre en fallas inversas, relacionadas con los pliegues más apretados de los estratos Pochico, se propone en este trabajo un modelo genético por el que se atribuye la formación de estos filones al relleno de fracturas de tensión asociadas con zonas de cizalla subparalelas al plano axial de los pliegues, y que evolucionaron según un proceso continuo, desde dúctiles (simple flexión) a frágiles (falla inversa)

Chelarctus and Crenarctus (Crustacea: Scyllaridae) from Coral Sea waters, with molecular identification of their larvae

Chelarctus Holthuis, 2002 is widely distributed throughout the Indo-West Pacific, but its biogeographic patterns are unknown because Southern Hemisphere areas, such as the Coral Sea, remained poorly explored. Recent cruises organized by the Muséum national d'Histoire naturelle of Paris and the Australian Institute of Marine Science allowed the molecular identification of Crenarctus crenatus (Whitelegge, 1900), Chelarctus aureus (Holthuis, 1963) and Chelarctus crosnieri Holthuis, 2002 phyllosomae. The Coral Sea C. crenatus larvae are identical to stages IX and X of Scyllarus sp. Z, described in detail by Webber and Booth (2001). Descriptions of phyllosoma stages VI, IX and X of Ch. aureus and stages IX and X of Ch. crosnieri are also presented here. Morphological differences between Crenarctus and Chelarctus larvae are established for the first time and previous misidentifications in the literature are re-assessed

DNA extraction from formalin-fixed tissue: new light from the Deep-Sea

DNA samples were extracted from ethanol and formalin-fixed decapod crustacean tissue using a new method based on Tetramethylsilane (TMS)-Chelex. It is shown that neither an indigestible matrix of cross-linked protein nor soluble PCR inhibitors impede PCR success when dealing with formalin-fixed material. Instead, amplification success from formalin-fixed tissue appears to depend on the presence of unmodified DNA in the extracted sample. A staining method that facilitates the targeting of samples with a high content of unmodified DNA is provided

Integrative taxonomy methods reveal high mealybug (Hemiptera: Pseudococcidae) diversity in southern Brazilian fruit crops.

The Serra Gaúcha region is the most important temperate fruit-producing area in southern Brazil. Despite mealybugs (Hemiptera: Pseudococcidae) infesting several host plants in the region, there is a lack of information about the composition of species damaging different crops. A survey of mealybug species associated with commercial fruit crops (apple, persimmon, strawberry and grapes) was performed in Serra Gaúcha between 2013 and 2015, using both morphology and DNA analyses for species identification. The most abundant species were Pseudococcus viburni (Signoret), found on all four host plant species, and Dysmicoccus brevipes (Cockerell), infesting persimmon, vines and weeds. The highest diversity of mealybug species was found on persimmon trees, hosting 20 different taxa, of which Anisococcus granarae Pacheco da Silva & Kaydan, D. brevipes, Pseudococcus sociabilis Hambleton and Ps. viburni were the most abundant. A total of nine species were recorded in vineyards. Planococcus ficus (Signoret) and Pseudococcus longispinus (Targioni Tozzetti) were observed causing damage to grapes for the first time. A single species, Ps. viburni, was found associated with apples, while both Ps. viburni and Ferrisia meridionalis Williams were found on strawberry. Four of the mealybug species found represent new records for Brazil

Las mineralizaciones litiniferas del oeste de Salamanca y Zamora

The aim of this paper is to describe the most important geological, mineralogical and geochemical features of the Li ores (bouth pegmatites and quartz veins) located in the west part of the Salamanca and Zamora provinces. The pegmatites mostly belong to the lepidolite type and they are complex and zoned. In one case, the ore in the pegmatite is litiophilite, and the pegmatite is simple. The veins are quartz rich with ambligonite and sorne feldspar and sulphides. They appear always related to granitic rocks. All these bodies are also mineralized with cassiterite, and sorne of them contain columbite tantalite too.El objeto de este trabajo es el describir las características geológicas, mineralógicas y geoquímicas más importantes de las mineralizaciones de Li (pegmatitas y filones) localizadas en el oeste de las provincias de Salamanca y Zamora. La mayor parte de las pegmatitas son de lepidolita como mena de Li, resultando todas éstas ser complejas y zonadas. En un caso, la mineralización es de litiofilita y la pegmatita que la alberga es simple. Los filones son de cuarzo con ambligonita y algo de feldespato y sulfuros. Todos los yacimientos aparecen siempre en relación con rocas graníticas. A su vez, todos los cuerpos estudiados están mineralizados en casiterita, y algunos de ellos en columbo-tantalita también

Mach-Zehnder-based measurement of light emitting diodes temporal coherence

Objectives: The main objective of this work is to validate a Mach-Zehnder based interferometric method to measure the temporal coherence length of broadband finite size light sources such as Light Emitting Diodes (LEDs), and give a qualitative value of the temporal coherence length of white LEDs, for which nor their spectral width neither their emission peak wavelength are clearly defined. Motivation: Low-coherence light sources such as LEDs have opened many possibilities in applications in which using lasers introduces coherent noise (speckle) that hinders the performance of interferometric measurement techniques. The coherence length is an important characteristic of light sources for scientific applications related to diffraction, holography, tomography, or interferometry. The spatial coherence of a source depends on the distance from the source to the observation plane and its size, while the temporal coherence is related to the emission spectral width and the emission peak wavelength. Therefore, the temporal coherence is a characteristic of each source. Methodology and results: In this work, we use a Mach-Zehnder interferometer for the first time to measure the coherence degree and the temporal coherence length of quasi-monochromatic LEDs. We validate the technique by comparing the results to those obtained directly from the spectrum. Then, we use the tested interferometric method to measure the temporal coherence length of a white LED, for which neither the width of the spectrum nor the emission peak wavelength, are clearly defined. In this case, the Wiener-Khinchin theorem is used to validate the interferometric technique. A very interesting property of the method is that the temporal coherence length is obtained from a single measurement, without needing to perform a scanning. This method can be used also for other non-coherent sources such as halogen lamps, pulsed lasers, and so on. The obtained results will improve the characterization of light sources and the applications dealing with physical optics and electromagnetic interference. © 2022 The Author

Cutting tool tracking and recognition based on infrared and visual imaging systems using principal component analysis (PCA) and discrete wavelet transform (DWT) combined with neural networks

The implementation of computerised condition monitoring systems for the detection cutting tools’ correct installation and fault diagnosis is of a high importance in modern manufacturing industries. The primary function of a condition monitoring system is to check the existence of the tool before starting any machining process and ensure its health during operation. The aim of this study is to assess the detection of the existence of the tool in the spindle and its health (i.e. normal or broken) using infrared and vision systems as a non-contact methodology. The application of Principal Component Analysis (PCA) and Discrete Wavelet Transform (DWT) combined with neural networks are investigated using both types of data in order to establish an effective and reliable novel software program for tool tracking and health recognition. Infrared and visual cameras are used to locate and track the cutting tool during the machining process using a suitable analysis and image processing algorithms. The capabilities of PCA and Discrete Wavelet Transform (DWT) combined with neural networks are investigated in recognising the tool’s condition by comparing the characteristics of the tool to those of known conditions in the training set. The experimental results have shown high performance when using the infrared data in comparison to visual images for the selected image and signal processing algorithms