Vertical variation of atrazine mineralization capacity in soils

Se estudió la variación de la capacidad de mineralización de atrazina en dos suelos de la provincia de Córdoba, Argentina. Se seleccionaron dos perfiles de suelos con (suelo adaptado) y sin (suelo no adaptado) historia de aplicación de atrazina. La evolución de atrazina fue caracterizada mediante el balance de la radioactividad del 14C del anillo triazínico identificando las fracciones mineralizada,extractable y no extractable, durante incubaciones en condiciones de laboratorio con suelo tratado con calor (T105) y sin él (Control). La disminución de la capacidad de degradación de atrazina después de la inactivación microbiana y la limitada recuperación de esa capacidad observada en el perfil de suelo adaptado sugirió que los microorganismos degradadores de atrazina estarían distribuidos en todo el perfil siendo los responsables de la mineralización de atrazina en los horizontes subsuperficiales. Contrariamente, en el perfil de suelo no adaptado,la recuperación de la mineralización de atrazina a niveles similares o ligeramente superiores a los del Control corroboró la vía cometabólica del proceso característica de suelos sin historia de uso de atrazina. La capacidad de mineralizaciónde atrazina por los horizontes subsuperficiales, donde tiende a acumularse este herbicida, en suelos con aplicaciones frecuentes de atrazina debiera ser considerada y estimulada como un mecanismo de bioremediación natural

Bioerosion and palaeoecological association of osteophagous insects in the Maastrichtian dinosaur Arenysaurus ardevoli

Bioerosions produced by the osteophagous diet of animals that fed on dinosaur bones are very scarce in the European fossil record. Herein we present bioerosion on hadrosaurid remains from the Maastrichtian Tremp Formation of the Pyrenean Basin, which is only the second such case recorded from the Iberian-Occitan Plate besides a sauropod from the Jurassic-Cretaceous of Valencia. The hadrosaurid fossil record is particularly rich in the Blasi sites of the Tremp Formation located in the municipality of Arén (Huesca, Spain). In this article, bones referred to the hadrosaurid Arenysaurus ardevoli from the Blasi-3 site are analysed to shed light on the palaeoenvironment and on the presence of a palaeoecological interaction between the hadrosaurid carcase and osteophagous tracemakers. Bioerosions recorded on the bones comprise tunnels, roundish holes, and straight notches, similar to the traces attributed to necrophagous insects (cf. Cuniculichnus seilacheri). Here, we record the first instance of the activity of these animals on dinosaur bones in the Upper Cretaceous of the Ibero-Occitan Plate. The results presented lead us to infer that the Arenysaurus bones were possibly transported by a storm or similar event to the Blasi-3 site, where they were exposed to post-mortem biotic interactions (eaten and partially decomposed by dermestid beetles) for a prolonged time period before they were completely buried. © 2021 The Authors. Lethaia published by John Wiley & Sons Ltd on behalf of Lethaia Foundatio

Thermoelectric assessment of laser peening induced effects on a metallic biomedical Ti6Al4V

Laser peening has recently emerged as a useful technique to overcome detrimental effects associated to another well-known surface modification processes such as shot peening or grit blasting used in the biomedical field. It is worth to notice that besides the primary residual stress effect, thermally induced effects might also cause subtle surface and subsurface microstructural changes that might influence corrosion resistance. Moreover, since maximum loads use to occur at the surface, they could also play a critical role in the fatigue strength. In this work, plates of Ti-6Al-4V alloy of 7 mm in thickness were modified by laser peening without using a sacrificial outer layer. Irradiation by a Q-switched Nd-YAG laser (9.4 ns pulse length) working in fundamental harmonic at 2.8 J/pulse and with water as confining medium was used. Laser pulses with a 1.5 mm diameter at an equivalent overlapping density (EOD) of 5000 cm-2 were applied. Attempts to analyze the global induced effects after laser peening were addressed by using the contacting and non-contacting thermoelectric power (TEP) techniques. It was demonstrated that the thermoelectric method is entirely insensitive to surface topography while it is uniquely sensitive to subtle variations in thermoelectric properties, which are associated with the different material effects induced by different surface modification treatments. These results indicate that the stress-dependence of the thermoelectric power in metals produces sufficient contrast to detect and quantitatively characterize regions under compressive residual stress based on their thermoelectric power contrast with respect to the surrounding intact material. However, further research is needed to better separate residual stress effects from secondary material effects, especially in the case of low-conductivity engineering materials like titanium alloys

Identification and characterization of laccase-type multicopper oxidases involved in dye-decolorization by the fungus Leptosphaerulina sp.

13 p.-4 fig.-4 tab.[Background] Fungal laccases are multicopper oxidases (MCOs) with high biotechnological potential due to their capability to oxidize a wide range of aromatic contaminants using oxygen from the air. Albeit the numerous laccase-like genes described in ascomycete fungi, ascomycete laccases have been less thoroughly studied than white-rot basidiomycetous laccases. A variety of MCO genes has recently been discovered in plant pathogenic ascomycete fungi, however little is known about the presence and function of laccases in these fungi or their potential use as biocatalysts. We aim here to identify the laccase-type oxidoreductases that might be involved in the decolorization of dyes by Leptosphaerulina sp. and to characterize them as potential biotechnological tools.[Results] A Leptosphaerulina fungal strain, isolated from lignocellulosic material in Colombia, produces laccase as the main ligninolytic oxidoreductase activity during decolorization of synthetic organic dyes. Four laccase-type MCO genes were partially amplified from the genomic DNA using degenerate primers based on laccase-specific signature sequences. The phylogenetic analysis showed the clustering of Lac1, Lac4 and Lac3 with ascomycete laccases, whereas Lac2 grouped with fungal ferroxidases (together with other hypothetical laccases). Lac3, the main laccase produced by Leptosphaerulina sp. in dye decolorizing and laccase-induced cultures (according to the shotgun analysis of both secretomes) was purified and characterized in this study. It is a sensu-stricto laccase able to decolorize synthetic organic dyes with high efficiency particularly in the presence of natural mediator compounds.[Conclusions] The searching for laccase-type MCOs in ascomycetous families where their presence is poorly known, might provide a source of biocatalysts with potential biotechnological interest and shed light on their role in the fungus. The information provided by the use of genomic and proteomic tools must be combined with the biochemical evaluation of the enzyme to prove its catalytic activity and applicability potential.This research was supported by the Program for Interuniversity Cooperation and Scientific Reasearch (PCI) from the Spanish Agency for International Cooperation and Development (AECID), Project AP/033932/11, and the Spanish Project NOESIS BIO2014-56388-R.Peer reviewe

Ga+, In+ and Tl+ Impurities in Alkali Halide Crystals: Distortion Trends

A computational study of the doping of alkali halide crystals (AX: A = Na, K; X = Cl, Br) by ns2 cations (Ga+, In+ and Tl+) is presented. Active clusters of increasing size (from 33 to 177 ions) are considered in order to deal with the large scale distortions induced by the substitutional impurities. Those clusters are embedded in accurate quantum environments representing the surrounding crystalline lattice. The convergence of the distortion results with the size of the active cluster is analyced for some selected impurity systems. The most important conclusion from this study is that distortions along the (100) and (110) crystallographic directions are not independent. Once a reliable cluster model is found, distortion trends as a function of impurity, alkali cation and halide anion are identified and discussed. These trends may be useful when analycing other cation impurities in similar host lattices.Comment: LaTeX file. 7 pages and 2 pictures. Accepted for publication in J. Chem. Phy

Estado de micorrización de árboles truferos en función de su carácter productivo y su edad. Primeros resultados del Subproyecto 1 del Plan de Desarrollo Integral de la Truficultura de Teruel

La truficultura es una actividad con clara dimensión forestal, entre otras razones porque las especies implicadas, tanto el hongo como su árbol simbionte, son de gran valor silvícola. Además, la truficultura y la selvicultura trufera son prácticas que contribuyen a la recuperación de masas forestales y zonas potencialmente boscosas, con el valor añadido de la obtención de las trufas, de modo, en la mayor parte de las ocasiones, totalmente ecológico. El Plan Específico para Teruel (PET) integra varias actuaciones promovidas por el Gobierno Español entre las que se encuentra la ejecución de un Proyecto de Investigación denominado “Desarrollo Integral de la Truficultura de Teruel”, financiado por INIA, en el que se pretende apoyar al sector trufero turolense mediante el conocimiento y la mejora de sus técnicas de cultivo, producción y comercialización. La presente comunicación resume los primeros resultados obtenidos en uno de los 7 subproyectos que lo integran y que afecta al estudio del cortejo micorrícico de los árboles de las plantaciones, productoras o no, y su relación con la producción. La composición micorrícica de los árboles truferos es un factor esencial para realizar predicciones sobre la producción futura. Tanto la ausencia de micorrizas de trufa negra como la detección de otras, capaces de desplazar a la primera de las raíces de los árboles, puede permitir el diagnóstico precoz de fracasos de plantaciones y por lo tanto el ahorro de muchos años de cuidados a la espera de las primeras recolecciones. Para el estudio, se han seleccionado 3 grupos de plantaciones por edad, con 2 localizaciones distintas. Se está desarrollando un inventario periódico de las micorrizas presentes en un total de 48 árboles. Se propone una clasificación de las mismas en función de su capacidad para comprometer la producción de trufa negra, factor que se ha determinado en base al carácter productor o no productor de cada árbol

The detector control system of the ATLAS experiment

The ATLAS experiment is one of the experiments at the Large Hadron Collider, constructed to study elementary particle interactions in collisions of high-energy proton beams. The individual detector components as well as the common experimental infrastructure are supervised by the Detector Control System (DCS). The DCS enables equipment supervision using operator commands, reads, processes and archives the operational parameters of the detector, allows for error recognition and handling, manages the communication with external control systems, and provides a synchronization mechanism with the physics data acquisition system. Given the enormous size and complexity of ATLAS, special emphasis was put on the use of standardized hardware and software components enabling efficient development and long-term maintainability of the DCS over the lifetime of the experiment. Currently, the DCS is being used successfully during the experiment commissioning phase

Genética de las poblaciones ibéricas de trufa negra (Tuber melanosporum)

La trufa negra tiene una gran importancia económica y social. En el presente artículo de divulgación científica se muestran, de manera sencilla y breve, los resultados obtenidos en el primer estudio genético conducido sobre poblaciones ibéricas silvestres de Tuber melanosporum. Se ha detectado una elevada diversidad genética, que muestra el buen estado de conservación genética, así como una alta estructura genética entre poblaciones y una clara diferenciación entre los núcleos geográficos del noreste y sureste de la península ibérica, motivadas por la presencia del Sistema Ibérico, que puede estar actuando como barrera genética. Por otra parte, los resultados permiten pensar que la mayoría de las poblaciones meridionales, y algunas del centro y norte, sobrevivieron a las glaciaciones. Este artículo constituye la base de trabajos sobre expresión diferencial de aromas, conservación de la especie y desarrollo de marcas de calidad ligadas a este producto

Determination of an optimal response cut-off able to predict progression-free survival in patients with well-differentiated advanced pancreatic neuroendocrine tumours treated with sunitinib: an alternative to the current RECIST-defined response.

BACKGROUND: Sunitinib prolongs progression-free survival (PFS) in patients with advanced pancreatic neuroendocrine tumours (pNET). Response Evaluation Criteria in Solid Tumors (RECIST)-defined partial responses (PR; classically defined as ⩾30% size decrease from baseline) are infrequent. METHODS: Individual data of pNET patients from the phase II [NCT00056693] and pivotal phase III [NCT00428597] trials of sunitinib were analysed in this investigator-initiated, post hoc study. The primary objective was to determine the optimal RECIST (v.1.0) response cut-off value to identify patients who were progression-free at 11 months (median PFS in phase III trial); and the most informative time-point (highest area under the curve (AUC) by receiver operating characteristic (ROC) analysis and logistic regression) for prediction of benefit (PFS) from sunitinib. RESULTS: Data for 237 patients (85 placebo; 152 sunitinib (n=66.50 mg \u274-weeks on/2-weeks off\u27 schedule; n=86 \u2737.5 mg continuous daily dosing (CDD)\u27)) and 788 scans were analysed. The median PFS for sunitinib and placebo were 9.3 months (95% CI 7.6-12.2) and 5.4 months (95% CI 3.5-6.01), respectively (hazard ratio (HR) 0.43 (95% CI 0.29-0.62); P CONCLUSIONS: A 10% reduction within marker lesions identifies pNET patients benefiting from sunitinib treatment with implications for maintenance of dose intensity and future trial design

Optimizing omnidirectional reflection by multilayer mirrors

Periodic layered media can reflect strongly for all incident angles and polarizations in a given frequency range. Quarter-wave stacks at normal incidence are commonplace in the design of such omnidirectional reflectors. We discuss alternative design criteria to optimize these systems.Comment: 9 pages, 6 figures. To be published in J. Opt. A: Pure and Applied Optic