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U-Pb-age from undeformed granite pebbles in Carboniferous Culm conglomerates: new geochronological constrains on the Variscan events in the Pyrenees
No full textU-Pb ages of zircon and apatite in undeformed granite pebbles of synorogenic Carboniferous Culm conglomerates confirm the existence of an early Carboniferous (Visean to Bashkirian) magmatic event in the core of the Pyrenees. In this so-called Axial Zone, early Carboniferous magmatism developed in at least two main pulses, at ca. 340 Ma and ca. 320 Ma. Obtained ages constrain a mid-Bashkirian maximum age (ca. 320 Ma) for the base of Bellver Culm conglomerates. Together with the well-expressed late Variscan Moscovian-Asselian (ca. 310 to 295 Ma) granites that crosscut Culm rocks, this Visean to Bashkirian magmatism depicts three pulses of Variscan magmatism, grouped in two cycles of magmatic and tectono-thermal events recorded in the basement rocks of the Pyrenean Axial Zone. This complex Variscan evolution argues against previously proposed models claiming for a synkinematic emplacement of the Moscovian-Asselian granites linked to the main Variscan deformational events. Data obtained confirm the occurrence of Variscan events from the Visean to the Moscovian-Asselian in the Pyrenees. In this way, the Variscan basement rocks of the Pyrenees exhibit an evolution that aligns with that described for the rest of the European Variscan realm
Envers la síntesis de cicloalcans benzofusionats quirals mitjançant hidrogenació asimètrica catalitzada per iridi
No full textTreballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2025, Tutors: Xavier Verdaguer Espaulella, Martí Sidro InglésEnantioenriched chiral organic compounds, such as benzofused cycloalkanes, are key structures present in a large number of biologically active compounds, like natural products or pharmaceuticals. To answer this demand, asymmetric synthesis has gained a lot of interest in the last few years. So far, asymmetric hydrogenation has become one of the most relevant methodologies in the field, given its many benefits. However, it is still underdeveloped as a strategy for the synthesis of benzofused cycloheptanes.
Motivated by this, our group has worked on developing a new methodology towards the synthesis of these chiral compounds, through an iridium catalyzed asymmetric hydrogenation.
In this work, a benzofused methylene cycloheptane has been synthesized, and its asymmetric hydrogenation studied using different Ir-catalysts. Moreover, kinetic studies were conducted in order to analyze the effect of different catalysts in the isomerization process of the substrates. The results obtained led to the preparation of a new catalyst, Ir-NoaPHOX, that proved optimal by affording no isomerization process. Finally, Ir-NoaPHOX was tested on the asymmetric hydrogenation of benzofused methylene cycloheptanes, providing an enantiomeric excess of 89%.
Additionally, derivate benzofused methylene cycloheptanes substrates were prepared, to broaden the scope of the methodolog
In vitro exebacase (CF-301) activity against methicillin-susceptible or methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci strains isolated from patients with infective endocarditis
No full textBackground: Infective endocarditis (IE) is a severe infection mainly caused by Staphylococcus aureus, Enterococcus faecalis and viridans streptococci. Coagulase-negative staphylococci (CoNS), especially methicillin-resistant Staphylococcus epidermidis (MRSE), are major pathogens in prosthetic valves and devices. Exebacase is a first-in-class, antistaphylococcal lysin with rapid bactericidal and antibiofilm activity.
Objective: To assess the in vitro activity of exebacase and standard IE antibiotics against S. aureus and CoNS isolates from IE patients in a university hospital (2010-2020).
Methods: A total of 211 consecutive strains were analysed: S. aureus [n = 103 (82 MSSA, 21 MRSA)], S. epidermidis [n = 76 (20 MSSE, 56 MRSE)] and other CoNS species (n = 32, Staphylococcus haemolyticus, Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus capitis, Staphylococcus schleiferi, Staphylococcus caprae, Staphylococcus pasteuri). Broth microdilution MICs were determined for exebacase and comparators (cloxacillin, ceftaroline, vancomycin, daptomycin, gentamicin, rifampicin).
Results: Exebacase inhibited all S. aureus at ≤1 mg/L. Geometric mean (GM) MICs were 0.56 mg/L for MSSA and 0.49 mg/L for MRSA, with MIC50/90 of 0.5/1 mg/L. For S. epidermidis, GM MICs were 3.03 mg/L (MSSE) and 3.40 mg/L (MRSE), with MIC50/90 of 4/16 and 4/8 mg/L, respectively. Other CoNS showed GM MICs ranging from 0.49 mg/L (S. capitis) to 2.59 mg/L (S. lugdunensis), with intermediate values for S. haemolyticus (1.15), S. hominis (1.0) and S. schleiferi (0.79). Exebacase activity was comparable to β-lactams, vancomycin and daptomycin and remained unaffected by resistance.
Conclusions: Exebacase activity was independent of methicillin resistance and consistently higher against S. aureus than S. epidermidis. Further research is warranted to explore lysins in combination against staphylococcal infections
Audio-synchronized textual enhancement in foreign language pronunciation learning from videos
No full textThe benefits of multimodal input on foreign language listening comprehension and vocabulary learning are well-established, but only recently has its impact on pronunciation been explored. In this study, we audio-synchronized the highlighting of target words in captions to promote the activation of their phonolexical representations at the time they are auditorily processed and improve phonological updating in the mental lexicon. We recorded the eye movements of 58 L1-Spanish/Catalan learners of English as they watched two videos with target words (TWs) highlighted 500 ms or 300 ms before auditory onset, highlighted from caption onset or, alternatively, under one of two control conditions (unenhanced and uncaptioned). We assessed updating of phonolexical forms in terms of more accurate and faster rejection of mispronunciations of the TWs from pre-to post-test. Results showed that 300 ms synchronized enhancement and unsynchronized enhancement led to longer fixation duration, unsynchronized enhancement reduced TW skipping probability, and both synchronized conditions promoted higher audio-visual synchrony in learners' caption reading. While only the unsynchronized condition resulted in more accurate responses at post-test, all enhancement conditions led to significantly faster rejection of mispronunciations. These initial findings call for further research on audio-synchronized enhancement and its potential benefits for L2 pronunciation learning
Desenvolupament i validació de calibratges NIRS per l’anàlisi d’additius per a productes de nutrició animal
No full textTreballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2025, Tutors: Raimundo Gargallo Gómez, Josefa Aguilar ReinaThis final degree project focuses on the application of Near-Infrared Reflectance Spectroscopy (NIRS) as an alternative analytical technique to traditional methods for the analysis of additives intended for animal nutrition. It is a fast and non-destructive analytical technique that is becoming increasingly relevant in this industrial sector.
The main objective of this project is to design multivariate calibration models using NIRS, applying the mathematical methods mPLS and PCA, for the determination and quantification of various parameters, such as moisture and antioxidant content.
To achieve this objective, a robust database was built by analyzing the maximum number of available samples and assigning to each sample the reference values obtained using traditional analytical techniques, such as coulometric titration for moisture determination using Karl Fischer and gas chromatography (GC) for the quantification of different types of antioxidants.
Once all data were entered into the system, predictive models were developed using specific software, with the aim of correlating the NIRS spectra obtained from the analysis of the samples with their corresponding reference values. Subsequently, the models were
validated through the analysis of new samples, assessing their accuracy, precision, and robustness. Deviations were also identified and corrected to improve the prediction model.
The results obtained showed a high correlation (R² > 0.95) and low prediction errors, lower than those associated with traditional analytical methods, both in the determination of moisture and in the quantification of the two types of antioxidants, demonstrate the viability of NIRS as an alternative analytical metho
Síntesis y estudio cinético de procesos de fotoisomerización de compuestos de Pd(II) y Pt(II) solubles en agua
No full textTreballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2025, Tutora: Montserrat Sofía Ferrer GarcíaThis study focuses on the synthesis and characterization of water-soluble square-planar Pd(II) and Pt(II) complexes containing azobenzene ligands, specifically 4-phenylazopyridine (Phpy) and 4-aminoazopyridine (Ampy), with the aim of studying the cis-trans isomerization mechanism of the azo ligand coordinated to the metal center.
Once the indicated azo derivatives were synthesized and characterized, the corresponding Pd(II) derivatives [Pd(TMEDA)(Ampy)2](NO3)2 and [Pd(TMEDA)(Phpy)2](NO3)2 were obtained through substitution reactions. In the case of [Pd(TMEDA)(Ampy)2](NO3)2, an equilibrium is observed when dissolved in water, whereas for [Pd(TMEDA)(Phpy)2](NO3)2, exhibits this phenomenon in water and methanol.
To prevent the observed de-coordination, Pt(II), a more inert metal center than Pd(II), was employed. However, when the square-planar complex [Pt(TMEDA)(NO3)2] was reacted with the Ampy ligand under the same conditions used for Pd(II), the desired Pt(II) diazo complex could not be obtained.
Despite the de-coordination equilibrium, the kinetics of the cis-trans isomerization of the diazo complex [Pd(TMEDA)(Phpy)2](NO3)2 and the corresponding Phpy ligand were studied by UV/Vis spectroscopy and the apparent rate constants as well as the activation parameters ΔH‡ and ΔS‡ were determined. Unfortunately, for the [Pd(TMEDA)(Ampy)2](NO3)2 the cis-trans isomerization process resulted so fast that it could not be monitored with the equipment available in the laborator
Tax Reform and Network Effects
No full textThis paper investigates the effects of a tax reform that eliminates tax rate heterogeneity and cumulative taxation using a general equilibrium model with multiple sectors with market power. Industries are connected through input-output linkages, and changes in taxation are not confined within industries. We calibrate the model to Brazil, a country with a highly distorted tax system. The revenue-neutral tax reform generates gains of 7.9% of GDP and 1.8% of welfare. Just eliminating VAT rate dispersion leads to a 6.0% increase in GDP. Due to propagation effects, in 10 sectors direct taxes increased but output and profits did not fall
Antiguo Oriente y marxismo : vigencia en español de la lectura marxista de las fuentes escritas
No full textPara analizar las fuentes escritas y su tradición, es conveniente que los historiadores eviten proyectar hacia el pasado los fenómenos del presente. Así, desde un planteamiento crítico, este libro analiza la lectura marxista de las fuentes escritas del Antiguo Oriente Próximo que se publicó en España en las últimas décadas del siglo xx. ¿Es aún válida la propuesta de interpretación marxista? La valoración que aquí se presenta no solo lleva a reexaminar los rasgos generales desde los que hoy entendemos la compleja realidad histórica del Antiguo Oriente, sino también a revisar a fondo nuestra actual percepción del marxismo como teoría de interpretación y como corriente historiográfica que, con salvedades, puede todavía aplicarse a una historia crítica del Antiguo Oriente Próximo
Linseed oil-based oleogels with wax versus behenate-based glycerides: crystal polymorphism, microstructure, and gel stability
No full textAlthough oleogels are promising substitutes for saturated fats, their widespread adoption is hindered by multiple factors, among which an insufficient understanding of their crystallization behavior remains a key barrier. This work presents the first systematic analysis of the crystallization behavior in thermo-reversible linseed oil (LO)-based oleogels. The investigation combines in situ X-ray diffraction with thermal and microscopic analyses across a wide temperature range (-80 °C to 80 °C). We compared three natural waxes, sunflower wax (SFW), candelilla wax (CDW), and rice bran wax (RBW), along with two behenate-based glycerides, glyceryl behenate (GB) and fully hydrogenated high erucic acid rapeseed oil (FHR), as gelators for structuring LO. While LO itself exhibited both sub-α and β′ polymorphs, wax-based oleogels predominantly stabilized the β′ form. In contrast, oleogels with FHR or GB showed coexisting α/β′ and α/sub-α forms, respectively. Additionally, a β′ to β transformation was observed upon further heating in FHR-containing oleogels. Although most oleogels exhibited higher oil-binding capacity (OBC) at 5 °C than at 25–35 °C, the GB-containing oleogel achieved the highest OBC at 35 °C. These findings highlight the essential role of gelator polymorphism and crystal morphology in tailoring oleogel properties, guiding the rational design of functional oleogels for specific applications
Westerlies migrations and volcanic records over the past 4,000 years from the Azores lacustrine sequences. Exploring correlations and impacts on Western Europe
No full textThe Azores region plays a crucial role as a pathway for precipitation fronts traversing the North Atlantic from west to east, driven by the prevailing westerly winds. Variations in the strength of the Azores High affect the dynamics of the North Atlantic Oscillation (NAO), leading to latitudinal shifts in the trajectory of the westerlies and jet stream current over time. Throughout the Holocene and Late Pleistocene, the Azores islands experienced numerous highly explosive eruptions. Volcanic ash from these events was primarily dispersed to the east, carried by the North Atlantic Jet Stream, with cryptotephras being found across the British Isles and Northern-Central Europe. To investigate how NAO variations influenced the latitudinal position of the westerlies and in the ash dispersal towards Europe during the Late Holocene, we analysed the stratigraphy and sedimentology from 20 lake sediment sequences across five islands of Azores and revise highstand/lowstand periods in several lakes in Europe. Our facies analysis of Azorean lakes revelated three long-term phases highstand at 0-0.6, 2.6-1.5 and >4.2-3.4 cal ka BP and two lowstand phases at 1.5-0.6 and 2.6-3.3 cal ka BP which are ultimately related to paleo-NAO intensity and signal variations. By modelling spatial and temporal climate variability between Azores and Europe, we tracked changes in the westerlies' latitudinal position over the last 4,200 years. Additionally, we characterized tephra deposits in Azorean lakes, creating a preliminary database to support future tephrostratigraphic and tephrochronological research. This framework can also be useful for recognising distal cryptotephra layers in Europe and North Africa.