Spanish National Research Council
Recent publications
The design of cascade reactions in synthetic programs is of interest, particularly if the individual steps involve catalyzed reactions, and simple and highly available molecules such as carbon dioxide (CO2), water (H2O), and dihydrogen (H2) are employed. Herein, a three‐step sequential reaction is shown from epoxides to dehydrogenated diols, catalyzed by a combination of commercially available ionic liquids and supported Pt species on charcoal (Pt/C) in low amounts (<0.05 mol%). The process involves first carbonation of epoxides with CO2, followed by the opening of the carbonate with H2O, and then an acceptor‐less dehydrogenation reaction of the resulting diol to release H2. The inclusion of this last step in the one‐pot synthesis of diols from epoxides is, to the knowledge, unprecedented. Reactive and kinetic experiments for each individual step reveal the key role of CO2 to avoid epoxide polymerizations and enable the synthesis of a clean diol for the final dehydrogenation reaction.
This document provides the conclusions of the pest survey card that was prepared in the context of the EFSA mandate on plant pest surveillance (M‐2020‐0114) at the request of the European Commission. The full pest survey card for Apriona cinerea, A. germari and A. rugicollis is published and available online in the EFSA Pest Survey Card gallery at the following link and will be updated whenever new information becomes available: https://efsa.europa.eu/plants/planthealth/monitoring/surveillance/apriona-cinerea-germari-rugicollis
The study of extreme precipitation events has become a major research topic due to its importance in a climate change context. The determination of extreme events and their study usually depend on the estimation of daily percentiles. Therefore, this research evaluates the performance of different approaches and methods to estimate daily precipitation percentiles. To achieve this, simulations of five different climate regimes were conducted to evaluate each method's performance. Four distinctive factors were considered: the percentile to be estimated, the usage of a wet day or all days, the estimation method, and the usage of a smoothing technique after the estimation. Regarding the usage of wet days, we found that a wet-day threshold of 0 mm generally performed better than a 1 mm threshold. Moving window approaches yielded better results than methods using only the calendar day, leveraging larger data subsets. Smoothing techniques, particularly Generalized Additive Models (GAM), significantly improved performance. The choice of wet-day definition and percentile depends on research goals, affecting threshold levels and the number of extreme events, which influence statistical analyses. Higher percentiles showed decreased method performance, being less representative. Given potential biases with wet-day thresholds and minimal performance differences, we recommend using all days for percentile estimation in future research. For this case, the moving empirical percentile estimation method with GAM smoothing is advised. Nevertheless, optimal techniques may vary by climate. Lastly, the differences in the annual frequency of extreme events index derived from ERA5-Land data using different percentile estimation methods were analyzed. The findings suggest that the choice of percentile estimation method has a greater impact on analyzing time series variability but less influence on linear trend analysis.
Background and aims Glomalin-related soil protein (GRSP), is a metabolite exuded by the extraradical hyphae of arbuscular mycorrhizal fungi (AMF), which enhances soil structure and consequently is often associated with improved fertility in forest soils. This study investigates how topography and local environmental conditions influence GRSP and its ratio with soil organic carbon (GRSP/SOC) to support forest management and carbon stock conservation. Methods In a 60-ha Jianfengling tropical montane rainforest plot, we investigated the spatial patterns of GRSP and GRSP/SOC across ridges, slopes, and valleys. Using a Random Forest model that accounted for spatial autocorrelation, we assessed how GRSP and GRSP/SOC varied with respect to topography, plant diversity, and soil physicochemistry. Results GRSP and GRSP/SOC exhibited strong spatial autocorrelation, with contrasting topographic trends: GRSP peaked in ridges but was lowest in valleys, whereas GRSP/SOC was highest in valleys. Soil total nitrogen, available phosphorus, and pH were key predictors of GRSP in ridges, while pH was the critical predictor of GRSP/SOC in valleys. Notably, total tree diversity—but not AMF-associated tree abundance or biomass— was significantly correlated with the relative contribution of easily extractable GRSP to SOC. Conclusions Topography strongly influences the spatial distribution of GRSP and GRSP/SOC in tropical montane rainforests, with divergent patterns between these metrics. Total tree diversity, rather than AMF tree diversity, better predicts GRSP/SOC variations, evidence of important feedbacks between plant communities and the potential to sequester carbon in soil. These findings highlight the need to integrate landscape heterogeneity and biodiversity into forest carbon management strategies.
Leaf angle distribution (LAD) impacts plant photosynthesis, water use efficiency, and ecosystem primary productivity, which are crucial for understanding surface energy balance and climate change responses. Traditional LAD measurement methods are time‐consuming and often limited to individual sites, hindering effective data acquisition at the ecosystem scale and complicating the modeling of canopy LAD variations. We present a deep learning approach that is more affordable, efficient, automated, and less labor‐intensive than traditional methods for estimating LAD. The method uses unmanned aerial vehicle images processed with structure‐from‐motion point cloud algorithms and the Mask Region‐based convolutional neural network. Validation at the single‐leaf scale using manual measurements across three plant species confirmed high accuracy of the proposed method (Pachira glabra: R² = 0.87, RMSE = 7.61°; Ficus elastica: R² = 0.91, RMSE = 6.72°; Schefflera macrostachya: R² = 0.85, RMSE = 5.67°). Employing this method, we efficiently measured leaf angles for 57 032 leaves within a 30 m × 30 m plot, revealing distinct LAD among four representative tree species: Melodinus suaveolens (mean inclination angle 34.79°), Daphniphyllum calycinum (31.22°), Endospermum chinense (25.40°), and Tetracera sarmentosa (30.37°). The method can efficiently estimate LAD across scales, providing critical structural information of vegetation canopy for ecosystem modeling, including species‐specific leaf strategies and their effects on light interception and photosynthesis in diverse forests.
Aim Understanding the joint influence of natural disturbance regime, connectivity and biogeography on the seasonal variation of community structure. Location Drying river networks (DRN) in Europe. Time Period Present. Major Taxa Studied Aquatic macroinvertebrates. Methods We analyse the taxonomic and trait structure of 638 macroinvertebrate communities sampled across 125 reaches with perennial and intermittent streamflow, surveyed in six DRNs across Europe, up to six times over 1 year. Results Richness and trait diversity of macroinvertebrate communities decreased with increasing drying frequency, but increased with spatio‐temporal connectivity in reaches with long drying events. Communities experiencing frequent drying events had higher relative abundance of taxa with a long lifecycle and drying resistance traits. Communities experiencing long drying events compensated by high spatio‐temporal connectivity, and had more taxa with high fecundity and high dispersal ability. Taxa richness peaked in summer but that pattern was more prominent when drying frequency was high. Trait diversity decreased throughout the year, showing increasing abiotic stress as the year progressed. Communities changed from communities of mobile, fecund, short‐lived taxa in spring and autumn to communities of long‐lived taxa in summer. However, when drying frequency increased, autumn communities shifted towards communities of long‐lived taxa. Macroinvertebrate community trait structure changed across Europe. It opposed communities from Mediterranean and/or upland DRNs (with more fecund and mobile taxa) to lowland DRNs (with more long‐lived taxa). Main Conclusions Frequency and duration of drying events and spatio‐temporal connectivity drive divergent macroinvertebrate community structures, suggesting the presence of an ecological threshold that explains the variability of disturbed ecosystems across broad spatial scales. These factors also influence seasonal variations, with macroinvertebrate communities shaped by distinct trait‐filtering processes throughout the year based on drying frequency. Ultimately, spatio‐temporal connectivity plays a crucial role in sustaining species richness and trait diversity in reaches experiencing intense drying.
This study investigates fluctuations in the spatial pattern of the North Atlantic Oscillation (NAO) during the Industrial Era. NAO variability was analyzed over successive 30‐year periods, clustering its spatial patterns using two metrics: the gradient (g) between its action centres and flux direction (fd). Three distinct NAO patterns were identified, each exhibiting significant implications for NAO–precipitation modulation in the North Atlantic region. Coupled Model Intercomparison Project (CMIP6) climate models were evaluated for their ability to replicate these observed patterns. While many models accurately reproduce all three patterns, they frequently misinterpret their frequencies, favouring a disproportionately stable NAO. This bias, consistent across historical, natural‐only, and greenhouse gas forcings (GHG only), as well as piControl simulations, appears intrinsic to the models. This misinterpretation is significantly reduced in ssp585 scenarios, suggesting a potential link between forcing levels and improved multidecadal NAO variability in models. The occurrence of those different NAO patterns introduces uncertainty in precipitation projections, as this bias can persist in future scenarios. These findings highlight the need for improved model representation of NAO spatial variability to enhance the reliability of precipitation projections, particularly for Europe.
Different selection pressures acting on females and males arising from sexual selection and sexual conflict may lead to sex-specific phenotypic expression of physiological traits. Importantly, sexual selection is affected by ecological and demographic factors. We explored whether population spatial structure modulates the effect of sexual selection on male and female standard metabolic rates and oxidative stress. For this purpose, we used selection lines of the seed beetle Callosobruchus maculatus subjected to divergent evolutionary regimes in the intensity of sexual selection (high vs. low, in polygamous vs. enforced monogamous populations, respectively) and the presence of metapopulation structure (absent vs. present). We found that the evolutionary treatments impacted physiological traits in a complex way. While in the selection regimes simulating metapopulation structure (i.e., divided populations) both sexes had similar metabolic rates, in undivided (unstructured) populations males had lower rates than females. Males from polygamous and undivided populations showed the lowest levels of antioxidant enzymes quantified as SOD, resulting in strong sexual dimorphism in SOD levels in this selection regime. The oxidative damage to lipids measured as TBARS levels, instead, were highest for both males and females from monogamous and undivided populations. On the whole, our results reveal two key insights. First, physiological traits evolve differently in females and males in response to sexual selection intensity and population spatial structure. Second, such sex-specific physiological responses are linked to selective pressures acting mostly on males. We highlight the importance of considering ecological and demographic factors when evaluating whether sexual selection drives sex-specific trait evolution.
Pyrimidine nucleotide homeostasis is critical for DNA replication and cell viability, yet its regulation in Trypanosoma brucei, the causative agent of African trypanosomiasis, remains poorly understood. Here, we characterize a T. brucei cytidine deaminase-like protein (TbCDA-like), a kinetoplastid-specific enzyme absent in mammals, that harbors a deaminase domain and a zinc-finger CCCH motif. Using RNA interference (RNAi) and overexpression approaches, we demonstrate that TbCDA-like modulates pyrimidine nucleotide pools, influencing both ribonucleotide and deoxyribonucleotide profiles. Overexpression of TbCDA-like resulted in a substantial reduction of dCTP and CTP levels while elevating dTTP and UTP pools, suggesting a role in cytidine derivative deamination. Conversely, RNAi-mediated depletion of TbCDA-like caused CMP accumulation and reduced dTTP levels. Notably, overexpression induced severe cytotoxicity, growth arrest, DNA damage and cell cycle defects, evidenced by sub-G1 populations, increased nuclear H2A phosphorylation and aberrant kinetoplast and nuclear morphologies. Localization studies revealed that TbCDA-like is primarily cytosolic and relocalizes to stress granules upon nutrient deprivation, suggesting a role in RNA metabolism. These findings establish TbCDA-like as a key regulator of pyrimidine nucleotide homeostasis in T. brucei, linking nucleotide imbalances to DNA replication stress and genome instability. Given its absence in mammals, TbCDA-like presents an attractive target for therapeutic intervention against trypanosomiasis.
Lower stratospheric ozone between 60°S and 60°N has continued to decline since 1998, despite the reduction of ozone‐depleting substances following the Montreal Protocol. Previous studies have shown that, while chemistry‐climate models reproduce the negative ozone trend in the tropical lower stratosphere as a response to increased upwelling, they fail to capture the ozone decline in northern midlatitudes. This study revisits recent lower stratospheric ozone trends over the period 1998–2018 using two types of simulations from the new Chemistry Climate Model Initiative 2022 (CCMI‐2022): REF‐D1, with observed sea surface temperatures, and REF‐D2, with simulated ocean. The observed negative trend in midlatitudes falls within the range of model trends, especially when considering simulations with observed boundary conditions. There is a large spread in the simulated midlatitudes ozone trends, with some simulations showing positive and others negative trends. A multiple linear regression analysis shows that the spread in the trends is not explained by the different linear response to external forcings (solar cycle, global warming, and ozone‐depleting substances) or to the main variability modes (El Niño‐Southern Oscillation and the quasi‐biennial oscillation) but is instead attributed to internal atmospheric variability. Moreover, the fact that some models show very different trends across members, while other models show similar trends in all members, suggests fundamental differences in the representation of the internal variability of ozone transport across models. Indeed, we report substantial intermodel differences in the ozone‐transport connection on interannual timescales and we find that ozone trends are closely coupled to transport trends.
Background Vascular smooth muscle cells loaded with cholesterol (foam-VSMCs) play a crucial role in the progression of human atherosclerosis. Exchange Protein Directly Activated by cAMP 1 (EPAC1) is a critical protein in the regulation of vascular tone, endothelial function, and inflammation. Our objectives were to identify proteins specifically secreted by foam human coronary VSMCs (foam-hcVSMC) to evaluate their potential as circulating biomarkers for diagnosing coronary artery disease (CAD), and to ascertain the mechanisms underlying their levels in the blood of patients with CAD. Methods and results Differential proteomics identified EPAC1 as a differential foam-hcVSMC-secreted protein. Circulating EPAC1 levels were measured by ELISA in blood from 202 patients with suspected CAD who underwent coronary computed tomography angiography (CCTA). Blood EPAC1 levels were significantly lower in CAD patients compared to controls (p < 0.001). EPAC1 levels were reduced in both men and women with severe CAD (SIS > 4) compared to those with moderate CAD (SIS 1–4). ROC analysis identified 9.16 ng/ml as the optimal EPAC1 cut-off for severe CAD. At this threshold, EPAC1 predicted severe CAD (SIS > 4) with 69.6% sensitivity and 79.4% specificity, outperforming hs-CRP and hs-TnT in predicting CAD severity. Real-time PCR and Western blot analysis revealed that human foam-SMCs under hypoxic conditions exhibited a significant reduction in EPAC1 mRNA (p = 0.013) and protein (p < 0.001) levels. Conclusions These findings suggest that circulating EPAC1 protein levels lower than 9.16 ng/mL are predictive of severe CAD in humans. Hypoxic foam-SMCs, characteristic of advanced atherosclerotic lesions, exhibit diminished production of EPAC1, potentially contributing to the decreased circulating EPAC1 levels in patients with severe CAD.
Artificial lighting, essential for geotouristic purposes in subterranean sites, has facilitated the growth of colored photosynthetic organisms (lampenflora) on two monumental 19th‐century bas‐reliefs of the Pommery Champagne cellar ‐ a UNESCO‐protected heritage site ‐ causing significant aesthetic and physical deterioration. To sustainably preserve these stone artworks, biocidal polyoxometalate‐ionic liquids (POM‐ILs) were tested alongside the commercial biocide Preventol RI80® on three trial zones, cleaned and colonized areas of a wall, and clean stone samples positioned on a testing station within the cellar. After one year, untreated control areas exhibited growth/regrowth of green biofilms, whereas surfaces treated with POM‐ILs or Preventol RI80® remained biofilm‐free. Measurements of colorimetry and chlorophyll fluorescence confirmed the effectiveness of both biocides in controlling photosynthetic microorganisms. However, confocal fluorescence microscopy highlighted a reduced long‐term inhibition by Preventol RI80® compared to POM‐ILs, despite the latter being applied at lower concentrations. Metagenomic analysis validated the performance of POM‐ILs, showing a notable decrease in microbial richness and diversity in treated areas. While both products effectively inhibited phototrophs and fungi, their efficacy against Pseudomonadota was limited, due to microbial adaptation via antibiotic resistance genes. This study underscores the potential of POM‐ILs as a sustainable alternative for preserving cultural heritage against microbial colonization.
The role of egg nutrients in the embryonic development success of threatened marine reptiles remains relatively unexplored from a conservation perspective. This study assesses lipid and carotenoid profiles in leatherback turtle Dermochelys coriacea eggs, which have the lowest hatching success among marine turtles. Correlations between inter-individual nutrient concentrations and reproductive parameters were also investigated. Samples from 47 eggs in 18 clutches from different females were chemically examined at Playa Pacuare Reserve, Costa Rica. Carotenoid concentrations were consistently low compared to other marine turtle species and positively correlated with the proportion of eggs with yolk within each clutch. Larger females deposited eggs with higher proportions of saturated fatty acids, which correlated directly with nest fertility and hatchling size. Our results on the concentrations of lipid nutrients (carotenoids and fatty acids) and their measured correlations with persistent organic pollutants (POPs) and reproductive success indicators reveal that these factors may have a much more significant relevance to reproductive success than previously recognized and deserve further attention from conservation biologists. Integrating egg yolk nutrients into the reproductive scenario of marine turtles opens several avenues for further research. Given the spatial variability of the effects of increasing global pollution and the apparent relationship between nutrients and persistent organic pollutants in egg yolk, studies focusing on improving incubation success should carefully monitor the balance and reproductive effects of these compounds.
We investigated the role of TP53 splicing regulatory elements (SREs) using exons 3 and 6 and their downstream introns as models. Minigene microdeletion assays revealed four SRE-rich intervals: c.573_598, c.618_641, c.653_669 and c.672+14_672 + 36. A diagnostically reported deletion c.655_670del, overlapping an SRE-rich interval, induced an in-frame transcript Δ(E6q21) from new donor site usage. Deletion of at least four intron 6 G-runs led to 100% aberrant transcript expression. Additionally, assay results suggested a donor-to-branchpoint distance <50 nt for complete splicing aberration due to spatial constraint, and >75 nt for low risk of splicing abnormality. Overall, splicing data for 134 single nucleotide variants (SNVs) and 27 deletions in TP53 demonstrated that SRE-disrupting SNVs have weak splicing impact (up to 26% exon skipping), while deletions spanning multiple SREs have profound splicing effects. Our findings may prove relevant for identifying novel germline TP53 variants causing hereditary cancer predisposition and/or somatic variants contributing to tumorigenesis.
We present a 28‐year‐old Spanish female with a de novo heterozygous variant in FMR1 (NM_002024.6:c.1061_1062delAA), p.(Lys354Thrfs*15) detected by whole‐exome sequencing and confirmed by Sanger sequencing from cDNA. She was born full‐term with neonatal jaundice requiring phototherapy. At age 11, she exhibited weight and head circumference > 97th percentile, global developmental delay, mild ID (IQ: 71), and hyperactivity. FMR1 CGG analysis was normal. NGS panel of over 200 OGS‐related genes found no pathogenic variants. By age 28, she presented with macrocephaly, coarse facial features, mild joint hypermobility, left talo‐valgus, a port‐wine stain, a café‐au‐lait spot, and a piezogenic papule. Herein, we describe a clinical and molecular report of the second FXS female patient due to a heterozygous point variant. This study was approved by the ethical committee of Hospital Universitario La Paz (CEIm PI‐446), and informed consent was obtained from the patient and her parents.
Elevated temperatures during early developmental stages play a pivotal role in the fate of the adult sexual phenotype of fish populations, usually leading to male-skewed sex ratios. This is the case with European sea bass (Dicentrarchus labrax), one of the most important species in the European aquaculture industry. To unveil informative markers of the past thermal events, we investigated changes in the miRNome within the gonads of this species. Consequently, we exposed European sea bass to elevated temperatures (21ºC) during early development (from 7 to 68 days post fertilization). After one-year post-heat treatment growing at natural temperature, a miRNA-sequencing analysis was conducted in the ovaries and testes of juvenile fish. The examination of miRNA expression levels identified three and twelve miRNAs in ovaries and testes, respectively, reflecting past thermal events. To assess the evolutionary conservation of these identified miRNAs in gonads, we cross-referenced our data with miRNome public information from ovaries and testes in nine additional fish species from the FishmiRNA database. This analysis uncovered 33 potential sex-biased markers present in at least five studied species along the evolutionary timeline. For instance, miR-155, miR-429, and miR-140 were consistently female-skewed, while miR-143, miR-499, and miR-135b-3p were consistently male-skewed. In addition, among these markers, three conserved sex-skewed miRNAs proved to be informative regarding past thermal events in the ovaries (e.g., miR-192-5p, miR-146a-5p and miR-143-3p) and four in the testes (miR-129-5p, miR-724-5p, miR-143-3p, and miR-223-3p). Notably, miR-223-3p was conserved female-skewed, but showed upregulation in males exposed to high temperature, and miR-143-3p was inhibited in both heated females and males. These miRNAs could serve as markers of heat-induced masculinization. This research broadens the inventory of sex-specific miRNAs across evolution in fish, and elucidates thermosensitive miRNAs in the gonads.
This study examines the impact of synthesis parameters on the structural, optical, and catalytic properties of CuO nanoparticles, aiming to enhance their performance for applications in energy conversion, catalysis, and optoelectronics. CuO nanoparticles were synthesized through various chemical routes, and their properties were characterized using x‐ray diffraction (XRD), scanning electron microscopy (SEM), and UV–Vis spectroscopy. The findings show that synthesis conditions, including temperature, precursor concentration, and reaction time, significantly influence crystallite size, morphology, bandgap energy, and catalytic activity. Higher synthesis temperatures and longer reaction times led to improved crystallinity and reduced particle size, which in turn lowered the bandgap energy and enhanced the optical properties. Optical characterization revealed that the bandgap could be fine‐tuned by adjusting synthesis parameters, making the nanoparticles suitable for specific optoelectronic applications. Catalytic performance tests demonstrated that the CuO nanoparticles exhibited excellent activity in degrading organic pollutants, with their performance strongly dependent on synthesis conditions. This research highlights the potential of CuO nanoparticles as versatile materials, with customizable properties for use in advanced technologies. By controlling synthesis parameters, the study provides a pathway for the targeted design of CuO nanoparticles, contributing to the development of efficient and sustainable nanomaterials for future technological applications.
The direct utilization of metals from electronic waste (e‐waste) in catalysis is a barely explored concept that, however, should be feasible for reactions where the catalytically active species can be formed in situ from the e‐waste metal pieces. This approach circumvents any capture or isolation of particular metals, thus saving additional treatments (extractions, neutralization, separations, washings, …) and valorizing the e‐waste in its own. Here, it is shown that a metallic contact (≈1 mg) of a computer´s random‐access memory (RAM) catalyzes a variety of organic reactions in high yields. For instance, one RAM contact catalyzes the one‐pot esterification‐hydration reaction between acyl chlorides, propargyl alcohols, and water, at room temperature in 93–99% yields with turnover frequencies >0.5 million per hour. In this way, >50 kg of organic products could be prepared with just the RAM contacts discarded per year in the Institute´s recycling bin. These results open the way to directly use e‐waste in catalysis for organic synthesis.
Ants occupy a great variety of habitats, perform essential ecological roles, and interact with a wide variety of other organisms. However, the interaction between ants and mollusks is a lesser‐explored relationship that can be categorized into (a) ant predation on mollusks, (b) shell collection as hoarding behavior, (c) the use of shells for nesting, and (d) myrmecophilic relationships. This study reports new data about several interactions from accidental field observations, a quantitative analysis of the snail shells found in 16 Messor ant nest cleanings, and a qualitative analysis of 51 additional nests of different species. We found 1127 snail shells from 20 species, most of them belonging to juveniles of the Geomitridae and Helicidae families. Notably, Granopupa granum was the only species found alive in the collected material. Furthermore, in our qualitative assessment, we found 86.8% of the analyzed nests with shell remains in the nest cleanings of at least nine ant species. Additional observations revealed ants transporting both empty shells and live snails to the nest, some living snail species around the nest entries, and additional interactions. Our results may support cases of (a) predation of snails of certain species by ants, as many shells were found with perforations compatible with ant attacks and we have recorded direct predation, (b) the collection of empty shells to gather the body remains of snails as a trophic resource or for other purposes, and (c) the potential existence of more myrmecophilous snail species than currently known, capable of living in ant nests without being attacked, like Cecilioides acicula, Ferrussacia folliculum, or G. granum. Although more studies are necessary to understand the intriguing relationship between ants and snails, the study of ant nest wastes can also become a valuable tool for detecting rare native micromollusc, as well as invasive, non‐native, and aquatic species.
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Jose Luis Chiara
  • Instituto de Química Orgánica General
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