A case study of zeolitization process: 'Tufo Rosso a Scorie Nere' (Vico Volcano, Italy). Inferences for a general model

This paper focuses on the authigenic mineralization processes acting on 'Tufo Rosso a Scorie Nere' (TRS), i.e. one of the main pyroclastic units of the Vico stratovolcano (Latium, Italy). The pyroclastic deposits appear in general massive and made of 'black vitreous vesiculated juvenile scoriae', immersed in an ashy matrix lithified after zeolitization processes. The main minerals are chabazite and phillipsite, and the zeolitic content is locally variable, reaching 68 % wt. Zeolites grow replacing both amorphous fraction and pre-existing phases, occurring inside both matrix and scoriae. Concerning scoriae, zeolitization moves from the rim to the core of the scoriaceous fragment as a function of (a) temperature of the fluids and (b) permeability (primary or secondary). Composition of parental fresh glass and that of zeolitized rocks is compatible with trachyte chemistry, lightly undersaturated in SiO2, and the alteration processes modified the parental rock chemical features. Zeolites genesis is ascribed to a 'geoautoclave-like system', and zeolites display a Si/Al ratio similar to that of the parental glasses. TRS presents promising mineralogical characteristics as supplementary cementitious material in the production of mixed cements

The role of neutrophils in pregnancy, term and preterm labour

Neutrophils are surveillance cells, and the first to react and migrate to sites of inflammation and infection following a chemotactic gradient. Neutrophils play a key role in both sterile inflammation and infection, performing a wide variety of effector functions such as degranulation, phagocytosis, ROS production and release of neutrophil extracellular traps (NETs). Healthy term labour requires a sterile pro-inflammatory process, whereas one of the most common causes of spontaneous preterm birth is microbial driven. Peripheral neutrophilia has long been described during pregnancy, and evidence exists demonstrating neutrophils infiltrating the cervix, uterus and foetal membranes during both term and preterm deliveries. Their presence supports a role in tissue remodelling via their effector functions. In this review, we describe the effector functions of neutrophils. We summarise the evidence to support their role in healthy pregnancy and labour and describe their potential contribution to microbial driven preterm birth

Chloride binding properties of a macrocyclic receptor equipped with an acetylide gold(I) complex: synthesis, characterization, reactivity, and cytotoxicity studies

In this work, we report the synthesis and characterization of a mono-nuclear “two wall” aryl-extended calix4]pyrrole receptor (2Au) decorated with an acetylide-gold(I)-PTA complex at its upper rim. We describe the1 H NMR titration experiments of 2Au and its “two wall” aryl-extended calix4]pyrrole synthetic precursors: the non-symmetric mono-iodo-mono-ethynyl 2 and the symmetric bis-iodo 3 with TBACl in dichloromethane and acetone solution. In acetone solution, we use isothermal titration calorimetry (ITC) experiments to thermodynamically characterize the formed 1:1 chloride complexes and perform pair-wise competitive binding experiments. In both solvents, we measured a decrease in the binding constant of the mono-nuclear 2Au complex for chloride compared to the parent mono-iodo-mono-ethynyl 2. In turn, receptor 2 also shows a reduction in binding affinity for chloride compared to its precursor bis-iodo calix4]pyrrole 3. The free energy differences (¿G) of the 1:1 chloride complexes cannot be exclusively attributed to their dissimilar electrostatic surface potential values either at the center of the meso-phenyl wall or its para-substituent. We conclude that solvation/desolvation processes play an important role in the stabilization of the chloride complexes. In acetone solution and in the presence of TBACl, 6Au, a reference compound for the acetylide Au(I)•PTA unit, produces a bis(alkynyl)gold(I) anionic complex 7Au]-. Thus, the observation of two separate sets of signals for the bound aromatic calix4]pyrrole protons, when more than 1 equiv. of the salt is added, is assigned to the formation of the chloride complexes of 2Au and of the “in situ” formed calix4]pyrrole anionic dimer 8Au]-. Finally, preliminary data obtained in cell viability assays of 2Au and 6Au with human cancer cells lines assign them with moderate activities showing that the calix4]pyrrole unit is not relevant. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Catalysis-free synthesis of thiazolidine–thiourea ligands for metal coordination (Au and Ag) and preliminary cytotoxic studies

The reaction of propargylamines with isothiocyanates results in the selective formation of iminothiazolidines, aminothiazolines or mixed thiazolidine–thiourea compounds under mild conditions. It has been observed that secondary propargylamines lead to the selective formation of cyclic 2-amino-2-thiazoline derivatives, while primary propargylamines form iminothiazoline species. In addition, these cyclic thiazoline derivatives can further react with an excess of isothiocyanate to give rise to thiazolidine–thiourea compounds. These species can also be achieved by reaction of propargylamines with isothiocynates in a molar ratio of 1 : 2. Coordination studies of these heterocyclic species towards silver and gold with different stoichiometries have been carried out and complexes of the type [ML(PPh3)]OTf, [ML2]OTf (M = Ag, Au) or [Au(C6F5)L] have been synthesised. Preliminary studies of the cytotoxic activity in lung cancer cells have also been performed in both ligands and complexes, showing that although the ligands do not exhibit anticancer activity, their coordination to metals, especially silver, greatly enhances the cytotoxic activity

Application of chemical geothermometers to a low temperature thermal system

The Tiermas geothermal system is one of the areas with the greatest geothermal potential in Aragón, however, its hydrogeological and geochemical features are still poorly known. In this study, the main hydrochemical features of these waters are presented and the reservoir temperature is approached by applying chemical geothermometers. These waters have a sulphate chloride sodium affinity, with nearly 40 ºC of spring temperature and an approximate flow rate of 200 l/s. The most likely aquifer seems to be located in the Paleocene and Eocene carbonates. However, due to the structural complexity of the area, the waters would also interact with the evaporitic facies present in the Eocene–Oligocene boundary. Two different hydrochemical groups have been distinguished based on their salinity, Na/Cl ratios, SO4 concentrations and TDS values. Despite the compositional variations detected in the springs, the geothermometric calculations allow to infer a reservoir temperature of 85 ± 17 °C. Good consistency has been obtained with the cationic geothermometers, which is an unusual situation for a geothermal system in carbonate–evaporitic materialsEl sistema geotermal de Tiermas representa una de las zonas con mayor potencial geotérmico de Aragón y, sin embargo, se sabe todavía poco acerca de sus características hidrológicas y geoquímicas. En este trabajo se presentan los principales rasgos hidroquímicos de estas aguas y se determina su temperatura en profundidad mediante la aplicación de geotermómetros químicos. Estas aguas tienen una afinidad clorurada sulfatada sódica, una temperatura de surgencia de casi 40 °C y un caudal de unos 200 l/s. El acuífero más probable se localizaría en los carbonatos del Paleoceno y Eoceno, pero debido a la complejidad estructural de la zona, las aguas entrarían en contacto con la facies evaporítica del tránsito Eoceno–Oligoceno, adquiriendo así dicha afinidad. Se han distinguido dos grupos hidroquímicos con una diferente salinidad, relación Na/Cl y concentraciones de SO4 y TSD. A pesar de las variaciones composicionales detectadas en las surgencias, los cálculos geotermométricos realizados permiten establecer un rango de temperaturas en el reservorio de 85 ± 17 °C, habiéndose obtenido buenos resultados con los geotermómetros catiónicos, situación poco habitual en sistemas termales instalados en materiales carbonatados – evaporítico

Contribution of water-limited ecoregions to their own supply of rainfall

The occurrence of wet and dry growing seasons in water-limited regions remains poorly understood, partly due to the complex role that these regions play in the genesis of their own rainfall. This limits the predictability of global carbon and water budgets, and hinders the regional management of naturalresources. Using novel satellite observations and atmospheric trajectory modelling, we unravel the origin and immediate drivers of growing-season precipitation, and the extent to which ecoregions themselves contribute to their own supply of rainfall. Results show that persistent anomalies in growing-season precipitation—and subsequent biomass anomalies—are caused by a complex interplay of land and ocean evaporation, air circulation and local atmospheric stability changes. For regions such as the Kalahari and Australia, the volumes of moisture recycling decline in dry years, providing a positive feedback that intensifies dry conditions. However, recycling ratios increase up to40%, pointing to the crucial role of these regions in generating their own supply of rainfall; transpiration in periods of water stress allows vegetation to partly offset the decrease in regional precipitation. Findings highlight the need to adequately represent vegetation–atmosphere feedbacks in models to predict biomass changes and to simulate the fate of water-limited regions in our warming climate

Accidental poisoning with Wedelia glauca (“sunchillo”) in a bull confirmed by analysis of rumen content

Wedelia glauca is an invasive, perennial plant of the Asteraceae family native to South America. Its toxicity is attributed to the presence of a hepatotoxic terpenoid known as atractyloside, a powerful inhibitor of cellular respiration and ATP synthesis. Cattle are the most frequently poisoned species, and the course of this poisoning is hyperacute or acute. Occasionally, it is possible to find fragments of plants in the rumen contents and indentify the dermis structure of the plants, as they do not undergo significant changes in spite of the mechanic and enzymatic activities occurring in the rumen. The macroscopic and microscopic anatomopathologic findings of a natural Wedelia glauca poisoning case in a Hereford bull are reported. It was confirmed by micrographic analysis of plant fragments found in the rumen contents and also in bales used to feed those animals

Unsupervised adaptation of deep speech activity detection models to unseen domains

Speech Activity Detection (SAD) aims to accurately classify audio fragments containing human speech. Current state-of-the-art systems for the SAD task are mainly based on deep learning solutions. These applications usually show a significant drop in performance when test data are different from training data due to the domain shift observed. Furthermore, machine learning algorithms require large amounts of labelled data, which may be hard to obtain in real applications. Considering both ideas, in this paper we evaluate three unsupervised domain adaptation techniques applied to the SAD task. A baseline system is trained on a combination of data from different domains and then adapted to a new unseen domain, namely, data from Apollo space missions coming from the Fearless Steps Challenge. Experimental results demonstrate that domain adaptation techniques seeking to minimise the statistical distribution shift provide the most promising results. In particular, Deep CORAL method reports a 13% relative improvement in the original evaluation metric when compared to the unadapted baseline model. Further experiments show that the cascaded application of Deep CORAL and pseudo-labelling techniques can improve even more the results, yielding a significant 24% relative improvement in the evaluation metric when compared to the baseline system