Estudio paleontológico de los Quirópteros del Cuaternario español

Se estudia la fauna de quirópteros del Cuaternario español, a partir de los restos reconocidos en 11 yacimientos distribuidos por toda la península Ibérica. Estos yacimientos abarcan cronológicamente desde el Pleistoceno Inlerior hasta el Holoceno inicial. Se reconoce la presencia en estos yacimientos de 3 familias, 8 géneros y 15 especies de quirópteros, que se describen y estudian sistemáticamente. Para este estudio se revisan los diferentes criterios de identificación utilizados habitualmente, especialmente aquéllos basados en la observación de dientes aislados, que constituyen la mayor parte del material examinado. Se concluye que la morfología dental es un criterio de gran importancia diagnóstica, mientras que los criterios métricos presentan una validez limitada. En este sentido se observan interesantes diferencias de tamaño entre los ejemplares estudiados de algunas especies y sus representantes actuales, que pueden ser relacionadas con factores climáticos. También se interpretan como influidos por el clima los cambios, respecto a las condiciones actuales, en la distribución de las especies. El conocimiento de la ecología de los representantes actuales de las especies estudiadas permite extraer, a partir del estudio de la distribución de los fósiles, conclusiones paleoecológicas y, en particular, paleoclimáticas de gran interés La distribución estratigrálica y geográfica de las diferentes especies estudiadas es comparada con la reconocida en otros yacimientos europeos, lo que permite sacar conclusiones de índole paleobiogeográlica

The fossil Middle Pleistocene bats from the Cave of Aldène (Hérault, France)

Los restos fósiles conservados en los sedimentos del Pleistoceno Medio de la cueva de Aldène (Francia) indican que al menos ocho especies diferentes ocuparon en algún momento la cueva. Myotis myotis, es la especie más frecuente y ha sido identificada en todos los niveles con Quirópteros. La altísima proporción de dientes sin desgaste, e incluso algún elemento de la dentición decidua hallados en un par de niveles permite reconocer que la cueva se utilizó como refugio para las colonias de cría de esta especie. En cietos niveles los restos de Myotis myotis se encuentran asociados a los de otras especies de los géneros Myotis, Rhinolophus, Pipistrellus, Barbastella y Miniopterus. Alguna de estas especies, aunque representadas por un menor número de restos, son indicativas de factores climáticos y paisajísticos, aportando datos adicionales a las interpretaciones paleoecológicas realizadas a partir de los roedores. [ABSTRACT] The fossils preserved in the sediments of the cave of Aldène show that this cave was used as a roosting place by at least eight different bat species during the Middle Pleistocene. Myotis myotis is the species best represented, and occurs at all the levels with bat remains. The high proportion of unworn teeth found of this species, together with some deciduous elements preserved at two different levels suggest the cave was occupied by nursery colonies. M. myotis occasionally shared the cave with other bat species from the genera Myotis, Rhinolophus, Pipistrellus, Barbastella and Miniopterus. Although these accompanying species are not so well represented in the associations, they provide interesting data concerning variations in the climatic conditions, to be compared to the interpretations carried out on the basis of the rodent fauna

New data on bat fossils from Middle and Upper Pleistocene localities of France

We describe the bat fossils preserved in four sites from the middle and upper Pleistocene, three of them being well-known French localities: the rock shelter of Les Valerots, the caves of l’Escale at Saint Estève Janson and ‘‘du Prince’’ at Grimaldi (Italy), and the filling of Combe-Grenal, all of them containing microvertebrate assemblages with yet undescribed bat fossils. All species represented in these four localities are still presently distributed in France and had been previously recorded in other Pleistocene localities of central and western Europe, including France. The four assemblages differ both in the abundance of bat fossils as in species composition. The characteristics of each assemblage are analysed under modern insights of bat taphonomy and ecology, and compared with those of other bat-bearing French localities of similar age. The relevance of these data concerning the use of the fossil bats to infer past environmental conditions is discussed. [RÉSUMÉ] Nous décrivons les restes fossiles de chauves-souris provenant de quatre sites du Pléistocène moyen et supérieur, dont trois localités françaises bien connues : l’abri sous roche des Valerots, les grottes de l’Escale à Saint Estève Janson et du Prince à Grimaldi (Italie), et le remplissage de Combe Grenal, toutes quatre contenant des assemblages de microvertébrés avec des fossiles de chauves-souris encore non-décrits. Toutes les espèces identifiées dans ces quatre localités sont toujours présentes en France et avaient déjà été identifiées dans d’autres localités pléistocènes d’Europe centrale et occidentale, dont la France. Les quatre assemblages diffèrent tant par l’abondance des fossiles de chauves-souris que par leur composition spécifique. Les caractéristiques de chaque assemblage sont analysées à la lumière des connaissances actuelles sur la taphonomie et l’écologie des chauves-souris, en comparaison avec celles d’autres localités françaises d’âge équivalent. La pertinence de ces données en ce qui concerne l’utilisation de chauves-souris fossiles à des fins de reconstruction paléoenvironnementale est discutée

Glucocorticoid Receptor Signaling in Skin Barrier Function

Glucocorticoids (GCs) are steroid hormones that regulate the physiology of all tissues and mediate stress responses. Synthetic GCs are commonly prescribed to treat chronic inflammatory conditions including the prevalent skin diseases—psoriasis and atopic dermatitis. GCs act through the GC receptor (GR, NR3C1), a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. In skin, GC therapeutic efficacy is due to the antiproliferative and anti-inflammatory actions of GR; however, in the long term, these benefits are accompanied by adverse profiles including skin atrophy, increased fragility, dehydration, augmented susceptibility to infections, and delayed wound healing. While the therapeutic actions of GC treatments have been extensively studied, only more recently has the physiological role of GR been addressed in skin. In vivo and in vitro studies in mouse and man have revealed an important function for GR in skin homeostasis. In particular, the characterization of gain- or loss-of-function mouse models has demonstrated relevant roles for GR in skin pathophysiology. The actions of GR are context dependent, and in skin, it regulates different gene subsets and biological processes depending on developmental stage and physiological state. Finally, recent findings emphasize the relevance of local GC biosynthesis and appropriate GR expression in maintaining skin homeostasis

Atrapamiento óptico de partículas de upconversion: fundamentos y aplicaciones

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de Materiales. Fecha de lectura: 28-07-2017Esta tesis tiene embargado el acceso al texto completo hasta el 28-01-2019El tema fundamental de esta tesis doctoral es el estudio del atrapamiento óptico de partículas de upconversion y su aplicación en ensayos biológicos. El atrapamiento óptico permite la manipulación de objetos, tanto nano como micrométricos, gracias a la presión de radiación que ejerce un haz láser focalizado. De esta manera, se puede controlar la posición del objeto atrapado en las tres dimensiones del espacio, empleando fuerzas ópticas cuya magnitud se encuentra entre unos pocos femtonewtons y cientos de piconewtons. El hecho de que las fuerzas ópticas se encuentren en el intervalo de aquéllas que rigen los procesos biológicos ha propiciado que esta herramienta tenga multitud de aplicaciones en el campo de la biología. Los materiales de upconversion tienen la capacidad de emitir luz en la región visible o ultravioleta tras la absorción de radiación de menor energía (en el infrarrojo) que la emitida. Fue a principios del siglo XXI cuando su utilización se disparó gracias a la aparición de las micro y nanopartículas de upconversion. Entre todas las características que presentan se puede destacar el hecho de que la luminiscencia de ciertas partículas de upconversion dependa de las propiedades del entorno como, por ejemplo, la temperatura. Actualmente, las partículas de upconversion se emplean en multitud de aplicaciones, desde la fabricación de placas solares al desarrollo de tintas de seguridad, pasando por ensayos biomédicos. En esta tesis doctoral se ha querido unir el potencial de la manipulación óptica con las extraordinarias características luminiscentes de las partículas de upconversion. En primer lugar, se desarrolló un sistema de pinzas ópticas modificado para la medida de la luminiscencia de la partícula ópticamente atrapada. Con este equipo experimental se caracterizó tanto las propiedades luminiscentes como el atrapamiento óptico de partículas de upconversion. Se determinó la dependencia de las fuerzas ópticas con las propiedades de la partícula con el fin de determinar las condiciones óptimas de atrapamiento. Además, se realizaron estudios fundamentales sobre la luminiscencia de partículas de upconversion. Gracias al atrapamiento óptico se pudo medir la luminiscencia de una única nanopartícula de upconversion ópticamente aislada. También se determinó la dependencia de la luminiscencia de partículas de upconversion no esféricas con el ángulo de polarización. Estos estudios preliminares permitieron determinar la orientación estable de las partículas en el interior de la trampa óptica. Finalmente, se empleó todo lo aprendido del atrapamiento óptico de partículas de upconversion para la realización de experimentos in vitro. Se midió la extensión y magnitud del gradiente térmico generado en las proximidades de una célula sometida a un tratamiento fototérmico, empleando una partícula de upconversion ópticamente atrapada. También se desarrolló una técnica microreométrica para la medida de la viscosidad intracelular basada en los torques ópticos inducidos sobre la partícula atrapada.The aim of this doctoral thesis is the analysis of the optical trapping of upconverting particles and its application in biological studies. Optical trapping allows the manipulation of nano and micrometric objects by means of the radiation pressure exerted by a focused laser beam. Thus, the optically trapped object can be three-dimensionally controlled by using optical forces in the range of several femtonewtons to hundreds of piconewtons. Optical trapping has multitude of applications in the biological field, since optical forces lie in the range of those ruling the biological processes. Upconverting materials have the ability to emit light in the ultraviolet and visible ranges of the electromagnetic spectrum after the absorption of radiation of lower energy (infrared) than that emitted. Such materials boosted their use at the beginning of the 21th century, when the fist upconverting micro and nanoparticles appeared. Among all the characteristics they present, it is worth mentioning that the luminescence of certain upconverting particles depends on the properties of the surrounding medium, such as the temperature. Nowadays, upconverting particles are used in lots of different applications, form the construction of solar cells to the development of security inks, including biomedical studies. This doctoral thesis joins together the potential of optical manipulation and the outstanding characteristics of the upconverting particles. In the first place, an optical tweezers setup, which allows the detection and analysis of the luminescence of the optical trapped particle, has been developed. By using this experimental setup, the luminescent features of the upconverting particles, as well as their optical manipulation, have been studied. The dependence of the optical trapping forces on the particle characteristics has been determined in order to find the best optical trapping conditions. In addition, fundamental studies on the upconverting particle luminescence have been carried out. The luminescence of an optically isolated upconverting particle has been measured. Moreover, the dependence of the upconversion luminescence of non-spherical particles with the polarization state has been studied. These preliminary studies allowed to determine the stable orientation of the particles inside the optical trap. Finally, all the acquired knowledge about the optical trapping of upconverting particles has been used in the development of in vitro experiments. The extension and magnitude of thermal gradients created in the surroundings of a photothermally treated cell have been measured by means of an optically trapped upconverting particle. In addition, a microrheometry technique has been developed for the characterization of the intracellular viscosity. This method is based on the optical troques exerted over the trapped particle

Dripping dynamics and transitions at high Bond numbers

We report experiments on the dripping dynamics and jetting transitions that take place when a liquid is injected vertically downwards at a constant flow rate, for wide ranges of the liquid viscosity and injector radius. We explore values of the Bond number significantly larger than in previous works, revealing the existence of period-2 dripping regimes with satellite formation that do not exist at small Bond numbers. In addition, we quantify the influence of liquid viscosity on the hysteresis associated with the dripping-jetting transition, that had previously been studied only for the particular case of water.The authors thank the financial support of the Spanish MINECO through projects nos. DPI2014-59292-C03-01-P, DPI2014-59292-C03-03-P, DPI2015-71901-REDT, DPI2017-88201-C3-2-R and DPI2017-88201-C3-3-R. These research projects have been partly financed through European funds.Publicad

Epidermal inactivation of the glucocorticoid receptor triggers skin barrier defects and cutaneous inflammation.

9 páginas, 5 figuras. En material suplementario 7 figuras, 2 tablas.The glucocorticoid (GC) receptor (GR) mediates the effects of physiological and pharmacological GC ligands and has a major role in cutaneous pathophysiology. To dissect the epithelial versus mesenchymal contribution of GR in developing and adult skin, we generated mice with keratinocyte-restricted GR inactivation (GR epidermal knockout or GR(EKO) mice). Developing and early postnatal GR(EKO) mice exhibited impaired epidermal barrier formation, abnormal keratinocyte differentiation, hyperproliferation, and stratum corneum (SC) fragility. At birth, GR(EKO) epidermis showed altered levels of epidermal differentiation complex genes, proteases and protease inhibitors which participate in SC maintenance, and innate immunity genes. Many upregulated genes, including S100a8/a9 and Tslp, also have increased expression in inflammatory skin diseases. Infiltration of macrophages and degranulating mast cells were observed in newborn GR(EKO) skin, hallmarks of atopic dermatitis. In addition to increased extracellular signal-regulated kinase activation, GR(EKO) newborn and adult epidermis had increased levels of phosphorylated signal transducer and activator of transcription 3, a feature of psoriasis. Although adult GR(EKO) epidermis had a mild phenotype of increased proliferation, perturbation of skin homeostasis with detergent or phorbol ester triggered an exaggerated proliferative and hyperkeratotic response relative to wild type. Together, our results show that epidermal loss of GR provokes skin barrier defects and cutaneous inflammation.This work was supported by grant SAF2008-00540 and SAF2011-28115 of the Ministerio de Ciencia e Innovación/Economía y Competitividad from the Spanish Government and ACOMP2011/127 from Generalitat Valenciana. LMS holds a JAE-DOC contract partly supported by the EC and VL is a recipient of an FPI fellowship of MICINN (BES-2009-021944).Peer reviewe

Selective ablation of glucocorticoid receptor in mouse keratinocytes increases susceptibility to skin tumorigenesis.

9 páginas, 5 figuras. En material suplementario 5 figuras.We recently demonstrated that mice lacking the epidermal glucocorticoid (GC) receptor (GR) (GR epidermal knockout (GR(EKO)) mice) have developmental defects and sensitivity to epidermal challenge in adulthood. We examined the susceptibility of GR(EKO) mice to skin chemical carcinogenesis. GR(EKO) mice treated with a low dose of 12-dimethylbenz(a) anthracene (DMBA) followed by phorbol 12-myristate 13-acetate (PMA) promotion exhibited earlier papilloma formation with higher incidence and multiplicity relative to control littermates (CO). Augmented proliferation and inflammation and defective differentiation of GR(EKO) keratinocytes contributed to the phenotype, likely through increased AKT and STAT3 (signal transducer and activator of transcription 3) activities. GR(EKO) tumors exhibited signs of early malignization, including delocalized expression of laminin A, dermal invasion of keratin 5 (K5)-positive cells, K13 expression, and focal loss of E-cadherin. Cultured GR(EKO) keratinocytes were spindle like, with loss of E-cadherin and upregulation of smooth muscle actin (SMA) and Snail, suggesting partial epithelial-mesenchymal transition. A high DMBA dose followed by PMA promotion generated sebaceous adenomas and melanocytic foci in GR(EKO) and CO. Importantly, the number, growth kinetics, and extent of both tumor types increased in GR(EKO) mice, suggesting that in addition to regulating tumorigenesis from epidermal lineages, GR in keratinocytes is important for cross-talk with other skin cells. Altogether, our data reinforce the importance of GR in the pathogenesis of skin cancer.This work was supported by grant SAF2011-28115 of the Ministerio de Economía y Competitividad from the Spanish government. VL holds a fellowship from the MICINN (BES-2009-021944).Peer reviewe

Primeros datos sobre los micromamíferos (Roedores, Insectívoros, Quirópteros y Lagomorfos) del Solutrense (Pleistoceno Superior final) de la Cueva de Las Caldas (Oviedo, Asturias)

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu