Microbially induced palygorskite-sepiolite authigenesis in modern hypersaline lakes (Central Spain)

This study gives insight into the mechanisms of formation of palygorskite-sepiolite minerals that have remained elusive for many years. The occurrence of palygorskite-sepiolite and minor smectite in association with a variety of authigenic sulphates and Ca-Mg carbonate mineral deposits was identified in silicon-poor, saline to hypersaline ephemeral lakes in Central Spain. By a combination of sedimentological, mineralogical and petrological techniques (XRD, SEM, FEGSEM and TEM) it is shown that very small, poorly ordered palygorskite-sepiolite crystals resulted from the aggregation of nanocrystals within the matrix of the microbial mats (EPS) as it dehydrates. The Mg-rich clays nucleated on Mg-enriched EPS that also contain variable amounts of Si, Mg, Al and Fe, mostly derived from the degradation of siliciclastic minerals. The crystals have a broad compositional and textural range, from poorly ordered palygorskite laths to pure sepiolite bundles, suggesting that they grow through successive stages. Changes in the chemical composition of the fibers occur even at microscale, which is explained by the variability of the biogeochemical conditions prevailing in the microenvironments where the crystals grow. The overall results provide evidence for a biomediated-crystallization of palygorskite-sepiolite in microbial sediments

Evolution of Clays in Cretaceous Marly Series (Álava Block, Basque Cantabrian Basin, Spain): Diagenesis and Detrital Input Control

Two stratigraphic sections of carbonate sediments with significant thickness differences and without appreciable tectonic deformation were studied near the trough and on a threshold zone at the Álava Trough. Such characteristics make them appropriate to analyze the influence of a slow progression of the diagenesis over the original clay suite. X Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Analytical Electron Microscopy (AEM) techniques were applied in natural and alkylammonium-treated samples. Diagenesis slightly modified the clay mineralogy, the disappearance of smectite, and the variation in the content and ordering of the I/S mixed layer, with burial being the most noteworthy process. The total charge in the 2:1 expandable layers of smectite and I/S shows a slight increase, preferentially located on tetrahedral sheets, with depth. The data suggest a moderate diagenesis grade for the studied materials. The combination of techniques allowed identification of several types of detrital micaceous phases, as well-crystallized K-rich micas, Na-K micas, mica-chlorite stacks, and illites, with an expandable behaviour after the alkylammonium treatment. The total charge of illites did not change with diagenesis, suggesting their detrital origin. This research shows that the detrital assemblage masks the diagenetic evolution in the basin, which indicates the importance of the combination of different techniques to infer correctly the diagenetic grade in a sedimentary basin.This research was funded by the Spanish Government FEDER project CGL 2015-65404-R/BTE, CGL2016-75679-P, by the Basque Government project IT930-16, Research Group RNM-179 of the Junta de Andalucía and the Aragon Government project E18_17R

Blastocystis spp. en perdiz, codorniz y aves esteparias. Posible efecto del estrés y subtipo zoonótico en perdices de granja

Resumen del trabajo presentado al I Congreso Ibérico de Ciencia Aplicada a los Recursos Cinegéticos (CICARC), celebrado en Ciudad Real (España) del 1 al 4 de julio de 2019.Peer reviewe

Hydrothermal processes with REE enrichment in Fuerteventura carbonatites: evidences in accessory minerals

Los diques carbonatíticos que afloran en la parte centro-occidental del Complejo Basal de Fuerteventura (Ajuy, Punta de la Nao), fueron afectados por el evento intrusivo mioceno responsable del metamorfismo de contacto y fusión parcial de parte del complejo alcalino-carbonatítico. Las características texturales, los procesos de formación de monacita enriquecida en LREE (La, Ce, Nd) en microfracturas que afectan a los cristales de zircón, evidencian interacciones de las carbonatitas con fluidos hidrotermales y removilización parcial de REE. El pirocloro es el principal mineral reservorio de tierras raras (suma REE=216694 ppm), con valores elevados de LREE (LaN=185816 y CeN=165209) respecto a las HREE (YbN=2589 y LuN=1814) con un espectro bastante inclinado (La/Yb)N=72 en el diagrama de abundancia de REE. La paragénesis mineral representada por los interestratificados illita/esmectita, clorita y vermiculita permite encuadrar el evento hidrotermal en facies de las ceolitas (Ta ≈ 100-200 °C)Carbonatitic dykes that crop out in the central western part of Fuerteventura Basal Complex (Ajuy, Punta de la Nao), were affected by the Miocene intrusive event responsible for contact metamorphism and partial melting of part of the alkaline-carbonatitic complex. Textural characteristics, monazite enriched in LREE (La, Ce, Nd) formation processes in microfractures that affect zircon crystals, show carbonatite interactions with hydrothermal fluids and partial REE remobilization. Pyrochlore is the main mineral carrier of rare earth elements (sum REE=216694 ppm), with high LREE (LaN=185816 y CeN=165209) with respect to HREE (YbN=2589 y LuN=1814) with a rather steep pattern (La/Yb)N=72 in REE diagram. The mineral paragenesis represented by the interstratified illite/smectite, chlorite and vermiculite allows to frame the hydrothermal event in zeolite facies (T° ≈ 100-200 °C

Analysis of unexpected leaks in AISI 316L stainless steel pipes used for water conduction in a port area

This paper clarifies the causes of a corrosion process observed in austenitic stainless-steel pipes, grade 316L, used for conducting freshwater in a port area. During the pressure test of the installation, before it was put into service, about five months after its construction, a loss of pressure was detected due to leaks of the fluid contained and the presence of corrosion damage on the wall of the tubes, in some cases even passing through the thickness of the tube. An analysis of the chemical composition of the pipe material was carried out, as well as semi-quantitative analysis of the chemical composition of the deposits in the defects, and a culture of sulfate-reducing bacteria (SRB) in Kliguer medium of the stagnant waters within the facility. All this makes it possible to conclude that the observed process fits within the so-called microbiologically induced corrosion (MIC), and, in all probability, it can be affirmed that this process is promoted by the presence and proliferation of sulfate-reducing bacteria (SRB)

Protein-based salivary biomarkers for the diagnosis of periodontal diseases: Systematic review and meta-analysis

Objective: This systematic review and meta-analysis was aimed at determining differentially expressed protein-based biomarkers detectable in the saliva for the diagnosis of major periodontal diseases. Methods: A literature review was conducted through January 31, 2022. The methodological quality and risk of bias were assessed with the Newcastle-Ottawa scale for case-control studies. Heterogeneity among studies was analysed with the Q statistical test and the I2 test. p-values lower than 0.10 and I2 values higher than 50% indicated high heterogeneity among studies; therefore, the random-effects model was used. The analysis of biological pathways associated with the differentially expressed protein markers was performed with the STITCH integration analysis tool and was limited to interactions with high confidence levels (0.7). Results: Of all protein-based biomarkers detected, 12 were suitable for meta-analysis: IL-1beta, MIP-1alpha, albumin, TNF-alpha, ICTP, Ig-A, lactoferrin, MMP-8, IL-6, IL-8, IL-17 and PGE2. The salivary markers with high applicability were IL-1beta for differentiating patients with chronic periodontal disease from patients with gingivitis with an OE=73.5pg/mL; ICTP for differentiating patients with chronic periodontal disease from healthy control patients with an OE=0.091ng/mL; and PGE2 for differentiating patients with chronic periodontal disease from healthy control patients with an OE=36.3pg/mL. Conclusions: The biomarkers with the highest differential expression and the greatest potential for clinical applicability are IL-1beta for differentiating periodontitis from gingivitis, and ICTP and PGE2 for differentiating periodontitis from healthy status

The feeding of American plaice (Hippoglossoides platessoides), Redfish (Sebastes marinus) and Cod (Gadus morhua) in the Flemish Cap during July 1988

A randomly stratified bottom-trawl survey was realized in the Flemish Cap (NAFO Div. 3M) in July 1988. The stomach contents of three species were studied: 320 of American plaice (Hippoglossoides platessoides), 203 of redfish (Sebastes Marinus) and 468 of cod (Gadus morhua). The cod specimens were classified taking into account age groups; in the case of other species by length classes. The food items, the prey occurrence index and the diversity index were determined too. The Schoener overlap index was calculated to study the intraspecific diet overlap in cod and the interspecific diet overlap between the three species. The relation between predator size (cod) and prey size (redfish) was also studied

Caracterización geoquímica y mineralógica de sondeos de la Bahía de Portmán (Murcia, España)

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

A step back to move forward: a geological re-evaluation of the El Castillo Cave Middle Palaeolithic lithostratigraphic units (Cantabria, northern Iberia)

El Castillo Cave is one of the most important sites for understanding the Middle and Upper Palaeolithic in Europe. Despite its importance, the absence of a widely used stratigraphic section with detailed lithostratigraphic descriptions and correlations between the different geological and archaeological interpretations has led to confusion in the correct identification of lithostratigraphic units in the lowermost, Middle Palaeolithic sequence. This study establishes a new lithostratigraphic framework for the site, which can be accurately correlated to previous geological and archaeological studies and generates a solid working basis for framing the Mousterian of El Castillo Cave in the Cantabrian region and southwestern Europe. The geological re-evaluation of Unit XX (‘Mousterian Alpha’) has expanded its chronology, now ranging from 49 130–43 260 cal bp to 70 400 ± 9600 bp. Unit XXII (‘Mousterian Bet’) would consequently yield an age older than 70 400 ± 9600 bp and younger than the underlying speleothem (Unit XXIIIb), dated to 89 000 +11 000/-10 000 bp