Oxfordian and Kimmeridgian "Aspidoceras" in the Mediterranean. A methodological approach

In this study we present a contrastive analysis of the Null Hypothesis, established as the methodological basis for the evolutive investigation of Mediterranean "Aspidoceras" (Checa & Olóriz, 1985). This contrast is carried out using new data, and is part of a research programme which has been carefully planned. Paleogeographic, sedimentological. stratigraphic and palcobiological considerations have provided new evolutive models which in turn lead to a structural reorganization of thc Null Hypothesis. In this new structure, the Basic Evolutionary Conformations are no longer considcred as mere morphological groupings, the result of a direct reading of thc fossil record. In this way we propose morphological blocks, representing evolutive units which can be related to one another.En el presente trabajo se lleva a cabo un análisis contrastador de la Hipótesis Nula establecida como base metodológica para la investigación evolutiva de los"Aspidoceras" mediterráneos (Checa & Olóriz, 1985). Esta contrastación se lleva a cabo integrando nuevos datos y forma parte de un programa de investigación cuidadosamente planificado. Las diversas consideraciones paleogeográficas, sedimentológicas, estratigráficas y paleobiológicas han proporcionado nuevos modelos evolutivos que suponen una sustancial reorganización estructural de la Hipótesis Nula. En esta estructuración, las Configuraciones Evolutivas Básicas no son consideradas como meros grupos morfológicos, resultado de una lectura del registro fósil, sino que constituyen unidades evolutivas que pueden, por tanto, relacionarse entre sí

Arndt compositions: a generating functions approach

We use generating functions to enumerate Arndt compositions, that is, integer compositions where there is a descent between every second pair of parts, starting with the first and second part, and so on. In 2013, J\"org Arndt noted that this family of compositions is counted by the Fibonacci sequence. We provide an approach that is purely based on generating functions to prove this observation. We also enumerate these compositions with respect to the number of parts and the last part. From this approach, we can generalize some recent results given by Hopkins and Tangboonduangjit in 2023. Finally, we study some possible generalizations of this counting problem

Notes on the natural history of six nymphalid butterfly species from an Ecuadorian dry forest

Article published in the journal Tropical Lepidoptera Researc

Mapping spectroscopic uncertainties into prospective methane retrieval errors from Sentine-5 and its precursor

Sentinel-5 (S5) and its precursor (S5P) are future European satellite missions aiming at global monitoring of methane (CH4) column average dry air mole fractions (XCH4). The spectrometers to be deployed on-board the satellites record spectra of sunlight backscattered from the Earth\u27s surface and atmosphere. In particular, they exploit CH4 absorption in the shortwave infrared spectral range around 1.65 µm (S5 only) and 2.35 µm (both, S5 and S5P) wavelength. Given an accuracy goal of better than 2% for XCH4 to be delivered on regional scales, assessment and reduction of potential sources of systematic error such as spectroscopic uncertainties is crucial. Here, we investigate how spectroscopic errors propagate into retrieval errors on the global scale. To this end, absorption spectra of a ground-based Fourier Transform Spectrometer (FTS) operating at very high spectral resolution serve as estimate for the quality of the spectroscopic parameters. Feeding the FTS fitting residuals as a perturbation into a global ensemble of simulated S5 and S5P-like spectra at relatively low spectral resolution, XCH4 retrieval errors exceed 1% in large parts of the world and show systematic correlations on regional scales, calling for improved spectroscopic parameters

Ultrastructure of the Interlamellar Membranes of the Nacre of the Bivalve Pteria hirundo, Determined by Immunolabelling

The current model for the ultrastructure of the interlamellar membranes of molluscan nacre imply that they consist of a core of aligned chitin fibers surrounded on both sides by acidic proteins. This model was based on observations taken on previously demineralized shells, where the original structure had disappeared. Despite other earlier claims, no direct observations exist in which the different components can be unequivocally discriminated. We have applied different labeling protocols on non-demineralized nacreous shells of the bivalve Pteria. With this method, we have revealed the disposition and nature of the different fibers of the interlamellar membranes that can be observed on the surface of the nacreous shell of the bivalve Pteria hirundo by high resolution scanning electron microscopy (SEM). The minor chitin component consists of very thin fibers with a high aspect ratio and which are seemingly disoriented. Each fiber has a protein coat, which probably forms a complex with the chitin. The chitin-protein-complex fibers are embedded in an additional proteinaceous matrix. This is the first time in which the sizes, positions and distribution of the chitin fibers have been observed in situ.AJOM was financed by a PhD Grant of the FPI program from the Spanish Ministerio de Ciencia e Innovación; TCB's PhD Grant belonged to the FPU Program of the same Ministry. AJOM and AGC were supported by Projects CGL2010-20748-C02-01 and CGL2013-48247-P of the mentioned Ministry, and RNM6433 of the Consejería de Economía, Innovación y Ciencia of the Junta de Andalucía. The European COST Action TD0903 contributed via two Short Term Scientific Missions to AJOM in FM's lab in Dijon

Formation of the BiAg2 surface alloy on lattice-mismatched interfaces

We report on the growth of a monolayer-thick BiAg2 surface alloy on thin Ag films grown on Pt(111) and Cu(111). Using low energy electron diffraction (LEED), angle resolved photoemission spectroscopy (ARPES), and scanning tunneling microscopy (STM) we show that the surface structure of the 13 ML Bi/x-ML Ag/Pt(111) system (x=2) is strongly affected by the annealing temperature required to form the alloy. As judged from the characteristic (3×3)R30 LEED pattern, the BiAg2 alloy is partially formed at room temperature. A gentle, gradual increase in the annealing temperatures successively results in the formation of a pure BiAg2 phase, a combination of that phase with a (2×2) superstructure, and finally the pure (2×2) phase, which persists at higher annealing temperatures. These results complement recent work reporting the (2×2) as a predominant phase, and attributing the absence of BiAg2 alloy to the strained Ag/Pt interface. Likewise, we show that the growth of the BiAg2 alloy on similarly lattice-mismatched 1 and 2 ML Ag-Cu(111) interfaces also requires a low annealing temperature, whilst higher temperatures result in BiAg2 clustering and the formation of a BiCu2 alloy. The demonstration that the BiAg2 alloy can be formed on thin Ag films on different substrates presenting a strained interface has the prospect of serving as bases for technologically relevant systems, such as Rashba alloys interfaced with magnetic and semiconductor substrates

La Formación de Bellmunt (Unidad del Cadí, Pirineo oriental): aportaciones bioestratigráficas de los sistemas lacustres y palustres asociados

The Bellmunt Fm is an alluvial synorogenic unit which was deposited under the influence of the southward displacement of succesive pyrenean nappes. This unit includes, in the boundary between its lower and middle part, many lacustrine and palustrine beds with an abundant fossil fauna and flora. This fossil record allows to recognize thepaleoenviromental andpaleoclimatic scenary. Charophytes and fossil mammals indicate a Middle and Lower Bartonian age for this Formation

Estimación de la generación y composición de residuos sólidos en Papalotla, Tlaxcala

The objective of this work was to estimate the generation and composition of solid waste in the Colonies and Sections of Papalotla de Xicohténcat Municipality, Tlaxcala; in order to generate relevant information for the development of plans and management of solid waste in the study area. The samplings were carried out from April 22 to 29, 2019, in three randomly selected Colonies (El Potrero, Xilotzinco and San Buenaventura). The generation estimation was carried out using the procedure described in NMX-AA-61, with modifications in the sampling, since garbage collection trucks from the Municipal Services area were used. The characterization was carried out in accordance with NMX-AA-15-1985, which establishes the quartering method for municipal solid waste. With the average values of per capita generation, the generation for the rest of the colonies was estimated for different periods of time, in the same way we proceeded with the solid waste composition data. The results showed that Papalotla, Tlaxcala generates 44.3 tons of waste daily, of which 41% are organic materials, 20% plastic, 14% infectious biological material, 12% cardboard and paper, 7.5% glass, and the rest metals.El objetivo de este trabajo fue estimar la generación y composición de residuos sólidos de las Colonias y Secciones del Municipio de Papalotla de Xicohténcatl, Tlaxcala; con la finalidad de generar información pertinente para la elaboración de planes y manejo de residuos sólidos en la zona de estudio. Los muestreos se realizaron del 22 al 29 de abril del 2019, en tres Colonias seleccionadas al azar (El Potrero, Xilotzinco y San Buenaventura). La estimación de la generación se realizó empleando el procedimiento descrito en la NMX-AA-61, con modificaciones en el muestreo, ya que se utilizaron los camiones recolectores de basura del área de Servicios Municipales. La caracterización se realizó de acuerdo con la NMX-AA-15-1985, que establece el método de cuarteo para residuos sólidos municipales. Con los valores promedio de la generación per cápita, se estimó la generación para el resto de las colonias para diferentes periodos de tiempo, de igual forma se procedió con los datos de composición de residuos sólidos. Los resultados mostraron que Papalotla, Tlaxcala se generan diariamente 44.3 toneladas de residuos, de los cuales 41% son materiales orgánicos, 20% plásticos, 14 % material biológico infeccioso, 12% cartón y papel, 7.5% vidrio y el resto metales

The extracellular chaperone Clusterin enhances Tau aggregate seeding in a cellular model

Spreading of aggregate pathology across brain regions acts as a driver of disease progression in Tau-related neurodegeneration, including Alzheimer’s disease (AD) and frontotemporal dementia. Aggregate seeds released from affected cells are internalized by naïve cells and induce the prion-like templating of soluble Tau into neurotoxic aggregates. Here we show in a cellular model system and in neurons that Clusterin, an abundant extracellular chaperone, strongly enhances Tau aggregate seeding. Upon interaction with Tau aggregates, Clusterin stabilizes highly potent, soluble seed species. Tau/Clusterin complexes enter recipient cells via endocytosis and compromise the endolysosomal compartment, allowing transfer to the cytosol where they propagate aggregation of endogenous Tau. Thus, upregulation of Clusterin, as observed in AD patients, may enhance Tau seeding and possibly accelerate the spreading of Tau pathology