The Development of METAL-WRF Regional Model for the Description of Dust Mineralogy in the Atmosphere
The mineralogical composition of airborne dust particles is an important but often neglected parameter for several physiochemical processes, such as atmospheric radiative transfer and ocean biochemistry. We present the development of the METAL-WRF module for the simulation of the composition of desert dust minerals in atmospheric aerosols. The new development is based on the GOCART-AFWA dust module of WRF-Chem. A new wet deposition scheme has been implemented in the dust module alongside the existing dry deposition scheme. The new model includes separate prognostic fields for nine (9) minerals: illite, kaolinite, smectite, calcite, quartz, feldspar, hematite, gypsum, and phosphorus, derived from the GMINER30 database and also iron derived from the FERRUM30 database. Two regional model sensitivity studies are presented for dust events that occurred in August and December 2017, which include a comparison of the model versus elemental dust composition measurements performed in the North Atlantic (at Izaña Observatory, Tenerife Island) and in the eastern Mediterranean (at Agia Marina Xyliatos station, Cyprus Island). The results indicate the important role of dust minerals, as dominant aerosols, for the greater region of North Africa, South Europe, the North Atlantic, and the Middle East, including the dry and wet depositions away from desert sources. Overall, METAL-WRF was found to be capable of reproducing the relative abundances of the different dust minerals in the atmosphere. In particular, the concentration of iron (Fe), which is an important element for ocean biochemistry and solar absorption, was modeled in good agreement with the corresponding measurements at Izaña Observatory (22% overestimation) and at Agia Marina Xyliatos site (4% overestimation). Further model developments, including the implementation of newer surface mineralogical datasets, e.g., from the NASA-EMIT satellite mission, can be implemented in the model to improve its accuracy.
Solomos, Stavros; Spyrou, Christos; Barreto, África; Rodríguez, Sergio; González, Yenny; Neophytou, Marina K. A.; Mouzourides, Petros; Bartsotas, Nikolaos S.; Kalogeri, Christina; Nickovic, Slobodan; Vukovic Vimic, Ana; Vujadinovic Mandic, Mirjam; Pejanovic, Goran; Cvetkovic, Bojan; Amiridis, Vassilis; Sykioti, Olga; Gkikas, Antonis; Zerefos, Christos.
Combining in-situ monitoring and remote sensing to detect spatial patterns of volcanic sulphur impact on pine needles
Volcanic eruptions have a strong environmental impact on surrounding forests. Trees are affected by mechanical damage, tephra deposition and volcanic gases. Oceanic islands are shaped by relatively frequent volcanic eruptions and thus offer the opportunity to study the effect of volcanic activity on biodiversity. We investigate the impact of volcanic gas emissions and tephra deposition during the 2021 Tajogaite eruption on the Canary Pine forests of the island of La Palma, Spain, characterized by monospecific stands of the endemic pine species Pinus canariensis C. Sm. ex D.C. Large quantities of volcanic sulphur dioxide caused chlorotic damage up to approximately 7 km around the crater, followed by widespread resprouting of P. canariensis. To detect the spatial pattern of impacts, we sampled P. canariensis needles from all over the island of La Palma and analyzed their sulphur (S), nitrogen (N) and carbon (C) content. We found a strong increase of S needle content close to the crater, while C decreased significantly. S levels were strongly related to distance to the crater, C and N were mostly influenced by S content. Trees affected by volcanic gases allocate resources to resprouting, leading to lower levels of C due to translocation of C as a building block. Surprisingly, we found higher N levels in needles with high levels of S and a less clear pattern compared to C, likely due to a multitude of environmental factors influencing N needle levels. We investigated how canopy damage patterns detected in Sentinel-2 remote sensing imagery after the eruption correlated to the in-situ needle contents. However, we did not find a clear correlation between in-situ needle values and spectral responses in remote sensing. While satellite images were well suited to analyse large scale patterns of canopy damage following the eruption, needle levels varied strongly on a local, tree-based level, which is not reflected in remote sensing imagery.
Weiser, Frank; Walentowitz, Anna; Baumann, Esther; Shatto, Christopher; Guerrero-Campos, María; Jentsch, Anke; Nogales, Manuel; Medina, Félix Manuel; Vetaas, Ole Reidar; Beierkuhnlein, Carl.
Conformational control enables boroxine-to-boronate cage metamorphosis
The discovery of molecular organic cages (MOCs) is inhibited by the limited organic-chemical space of the building blocks designed to fulfill strict geometric requirements for efficient assembly. Using intramolecular attractive or repulsive non-covalent interactions to control the conformation of flexible systems can effectively augment the variety of building blocks, ultimately facilitating the exploration of new MOCs. In this study, we introduce a set of boronic acid tripods that were designed using rational design principles. Conformational control was induced by extending the tripod's arms by a 2,3-dimethylbenzene unit, leading to the efficient formation of a tetrapodal nanometer-sized boroxine cage. The new building block's versatility was demonstrated by performing cage metamorphosis upon adding an aromatic tetraol. This led to a quantitative boroxine-to-boronate transformation and a topological shift from tetrahedral to trigonal bipyramidal.
Rondelli, Manuel; Delgado-Hernández, Samuel; Hernández Daranas, Antonio; Martín, Tomás.
La imperiosa necesidad de programar la asistencia a urgencias, atendiendo al cambio climático y las crisis de calidad del aire
El cambio climático y la crisis global de calidad del aire son fenómenos que están teniendo impactos en numerosos aspectos de la sociedad, incluyendo la atención médica en general y en los servicios de urgencias en particular. En 2021 la Organización Mundial de la Salud declaró que el cambio climático es “la mayor amenaza para la salud a la que enfrenta la humanidad”1, motivo por el que este organismo publicó nuevas directrices de calidad del aire, recomendando reducir drásticamente los niveles de contaminación en el aire ambiente. Recientemente, y en relación a los escenarios meteorológicos que estamos viviendo en este nuevo escenario climático, el secretario general de la ONU declaro “la humanidad ha abierto las puertas del infierno”.
Benito Lozano, Miguel; Rodríguez, Sergio.
TBS-pyrrole as an “universal” reference to quantify artemisinin and structurally-diverse natural products in plants extracts by NMR
The commercial production of artemisinin and other valuable bioactive natural products depends on their plant sources, which may provide variable amounts of the compound depending on plant variety, the period of the year, abiotic stress and other factors. Therefore, it requires a method for large-scale, low-cost natural product quantification. The standard HPLC and UHPLC methods are accurate but the analysis are costly and require different optimization for structurally-diverse products. An alternative method using NMR with TBS-pyrrole as a novel “universal” reference affords a simple, fast method to quantify many different products. The method is shown with antimalarial artemisinin, whose yield using conventional and novel extraction procedures was determined by standard UHPLC-MS procedures and by our NMR protocol, with similar quantification results. The novel reference compound does not interfere with artemisinin or extract signals, only needs a small amount of the extract, is accurate and operationally simple, and a large volume of samples can be processed in little time. Moreover, bioactive terpenes, steroids, alkaloids, aromatic compounds, and quinones, among others, were quantified in a model vegetal extract with this “universal” reference with excellent accuracy.
García-García, Ana L.; Hernández, Dácil C; Santana-Mayor, Álvaro; Jiménez-Arias, David; Boto, Alicia.
Síntesis de éteres cíclicos naturales
Se presenta un resumen de algunos métodos utilizados en la síntesis de productos naturales bioactivos de origen marino. El artículo se estructura acorde al orden en que son introducidos los enlaces más importantes en los heterociclos oxigenados. Se discute asimismo la similitud de algunos métodos sintéticos utilizados con los usados por los organismos vivos productores.
Betancort, Juan M.; Carrillo Fumero, Romen; Díaz Díaz, David; García, Celina; Martín, Tomás; Padrón, Juan I.; Padrón, José M.; Ramírez, Miguel Á.; Martín, Víctor S.
Ligand-Directed Chemistry on Glycoside Hydrolases – A Proof of Concept Study
Selective covalent labelling of enzymes using small molecule probes has advanced the scopes of protein profiling. The covalent bond formation to a specific target is the key step of activity-based protein profiling (ABPP), a method which has become an indispensable tool for measuring enzyme activity in complex matrices. With respect to carbohydrate processing enzymes, strategies for ABPP so far involve labelling the active site of the enzyme, which results in permanent loss of activity. Here, we report in a proof of concept study the use of ligand-directed chemistry (LDC) for labelling glycoside hydrolases near – but not in – the active site. During the labelling process, the competitive inhibitor is cleaved from the probe, departs the active site and the enzyme maintains its catalytic activity. To this end, we designed a building block synthetic concept for small molecule probes containing iminosugar-based reversible inhibitors for labelling of two model β-glucosidases. The results indicate that the LDC approach can be adaptable for covalent proximity labelling of glycoside hydrolases.
Prasch, Herwig; Wolfsgruber, Andreas; Thonhofer, Martin; Culum, André; Mandl, Christoph; Weber, Patrick; Zündel, Melanie; Nasseri, Seyed A.; González Santana, Andrés; Tegl, Gregor; Nidetzky, Bernd; Gruber, Karl; Stütz, Arnold E.; Withers, Stephen G.; Wrodnigg, Tanja M.
Biostimulant activity of Galaxaura rugosa seaweed extracts against water deficit stress in tomato seedlings involves activation of ABA signaling
Water scarcity is a serious constraint for agriculture, and global warming and climate change can exacerbate it in many areas. Therefore, sustainable approaches must be implemented to deal with current and future water scarcity scenarios. Genetic and chemical approaches are being applied to manage this limitation and maintain crop yields. In particular, biostimulants obtained from natural sources such as marine algae are promising aids for coping with water deficit stress in agriculture. Here we present a bioprospection study of extracts of the macroalgae Bonnemaisonia hamifera, Galaxaura rugosa, Dasycladus vermicularis, Ulva clathrata, Cystoseira foeniculacea, Cystoseira humilis, Lobophora dagamae, Colpomenia sinuosa and Halopteris scoparia from the north coast of Tenerife, in the Canary Islands. The aqueous extracts of Bonnemaisonia hamifera, Galaxaura rugosa, Dasycladus vermicularis and Cystoseira humilis show biostimulant activity against water deficit stress in tomato seedlings under controlled conditions, providing higher tolerance than the mock-treated control. The Galaxaura rugosa extract showed the highest biostimulant activity against water deficit stress. We demonstrate that this positive effect involves the activation of the abscisic acid (ABA) pathway in Arabidopsis thaliana (arabidopsis) and Solanum lycopersicum (tomato). Application of G. rugosa extract to the root system by drenching tomato seedlings subjected to water deficit leads to improved CO2 assimilation and water use efficiency (WUEp), compared to mock-treated plants. These results highlight a new potential seaweed source of substances with osmoprotectant properties, useful for biostimulant development. Future studies may provide further insight into which components of the seaweed extract induce activation of the ABA pathway.
Morales-Sierra, Sarai; Cristo Luis, Juan; Jiménez-Arias, David; Rancel-Rodríguez, Nereida M.; Coego, Alberto; Rodriguez, Pedro L.; Cueto, Mercedes; Borges, Andrés A.
Bubble-enhanced basanite–tephrite mixing in the early stages of the Cumbre Vieja 2021 eruption, La Palma, Canary Islands
Syneruptive magma mixing is widespread in volcanic eruptions, affecting explosivity and composition of products, but its evidence in basaltic systems is usually cryptic. Here we report direct evidence of mixing between basanitic and tephritic magmas in the first days of the 2021 Tajogaite eruption of Cumbre Vieja, La Palma. Groundmass glass in tephritic tephra from the fifth day of the eruption is locally inhomogeneous, showing micron-scale filamentary structures of Si-poor and Fe-, Mg-rich melt, forming complex filaments attached to bubbles. Their compositional distribution attests the presence of primitive basanitic magma, with compositions similar to late-erupted melts, interacting with an evolved tephritic melt during the first week of the event. From filament morphology, we suggest their generation by dragging and folding of basanitic melt during bubble migration through melt interfaces. Semi-quantitative diffusion modelling indicates that the filamentary structures are short-lived, dissipating in timescales of tens of seconds. In combination with thermobarometric constraints, we suggest a mixing onset by sub-Moho remobilization of a tephritic reservoir by basanite input, followed by turbulent ascent of a mingled magma. In the shallow conduit or lava fountain, bubble nucleation and migration triggered further mingling of the distinct melt-phases. This phenomenon might have enhanced the explosive behaviour of the eruption in such period, where violent strombolian explosions were common.
González-García, Diego; Boulesteix, Thomas; Klügel, Andreas; Holtz, François.
Diastereoselective Halogenation Reactions
A review of the last 10 years of diastereoselective halogenation methods is presented. They have been divided by reactions into alkenes, alkynes, and heterocycles. In many of the cases, the use of transition metals is described. In all of them, the mechanistic approach proposed by the authors and justifying the obtained diastereoselection is discussed. A miscellaneous section is also included in which allylic fluorinations, double bond isomerizations, ring expansion, and ring-opening halogenations are discussed.
Cruz, Daniel A.; Sinka, Victoria; Padrón, Juan I.