C∞\mathcal{C}^{\infty}-structures in the integration of involutive distributions

For a system of ordinary differential equations (ODEs) or, more generally, an involutive distribution of vector fields, the problem of its integration is considered. Among the many approaches to this problem, solvable structures provide a systematic procedure of integration via Pfaffian equations that are integrable by quadratures. In this paper structures more general than solvable structures (named cinf-structures) are considered. The symmetry condition in the concept of solvable structure is weakened for cinf-structures by requiring their vector fields be just cinf-symmetries. For cinf-structures there is also an integration procedure, but the corresponding Pfaffian equations, although completely integrable, are not necessarily integrable by quadratures. The well-known result on the relationship between integrating factors and Lie point symmetries for first-order ODEs is generalized for cinf-structures and involutive distributions of arbitrary corank by introducing symmetrizing factors. The role of these symmetrizing factors on the integrability by quadratures of the Pfaffian equations associated with the \cinf-structure is also established. Some examples that show how these objects and results can be applied in practice are also presented

C∞\mathcal{C}^{\infty}-symmetries of distributions and integrability

An extension of the notion of solvable structure for involutive distributions of vector fields is introduced. The new structures are based on a generalization of the concept of symmetry of a distribution of vector fields, inspired in the extension of Lie point symmetries to $\mathcal{C}^{\infty}$-symmetries for ODEs developed in the recent years. These new objects, named $\mathcal{C}^{\infty}$-structures, play a fundamental role in the integrability of the distribution: the knowledge of a $\mathcal{C}^{\infty}$-structure for a corank $k$ involutive distribution permits to find its integral manifolds by solving $k$ successive completely integrable Pfaffian equations. These results have important consequences for the integrability of differential equations. In particular, we derive a new procedure to integrate an $m$th-order ordinary differential equation by splitting the problem into $m$ completely integrable Pfaffian equations. This step-by-step integration procedure is applied to integrate completely several equations that cannot be solved by standard procedures

Genética de poblaciones amazónicas: la historia evolutiva del jaguar, ocelote, delfín rosado, mono lanudo y piurí, reconstruida a partir de sus genes

The Amazon has more than the half of the world's biodiversity. Nevertheless, the major fraction of the Amazon species has unknown evolutionary histories. This is also certain for mammals and birds. Population genetics, employing molecular markers and theoretical mathematics models, can reconstruct these evolutionary histories and offer very powerful tools for the application of correct conservation politics. Herein, we show a comparative view of population genetics results obtained for Amazon populations of jaguar, ocelot, pink river dolphin, woolly monkey and wattled curassow and provide recommendation for their biological conservation. Each species showed its own specific evolutionary particularities, characteristics that were not shared by the other species. This finding should be taken into consideration for any effective biological conservation program. Key words: Amazon, Population genetics, Panthera, Leopardus, Inia, Lagothrix, Crax.El Amazonas contiene más de la mitad de la biodiversidad a escala mundial. Sin embargo, muchas de las especies que alberga, poseen historias evolutivas totalmente desconocidas. Esto incluye el caso de los mamíferos y de las aves. La genética de poblaciones, mediante el uso de marcadores moleculares, modelos y metodologías matemáticas, puede intentar reconstruir esa historia evolutiva y ofrecer herramientas efectivas para la aplicación de políticas correctas de conservación. Se muestra aquí un resumen de los estudios genético realizados en poblaciones amazónicas de jaguar, ocelote, delfín rosado, mono lanudo y piurí y se proponen algunas recomendaciones para su conservación biológica. En cada especie se observaron particularidades evolutivas propias no compartidas por las otras especies. Este hecho debe ser recogido por cualquier programa de conservación que pretenda ser efectivo. Palabras clave: Amazonas, Genética de poblaciones, Panthera, Leopardus, Inia, Lagothrix, Crax

Nuevos registros de licofitas y helechos para el estado de Puebla, México

Antecedentes y Objetivos: Son pocos los trabajos florísticos que se han publicado sobre licofitas y helechos (pteridofitas en conjunto) de Puebla, México, por lo que se considera muy probable que la riqueza de especies en el estado sea mayor a la que se tiene documentada hasta el momento. El objetivo de este trabajo es reportar nuevos registros de este grupo de plantas para la entidad, incluyendo su distribución municipal y altitudinal, así como el tipo de vegetación en que se presentan. Métodos: De 2010 a 2018 se efectuaron diversos viajes de recolección a distintas localidades de Puebla, durante los cuales se recolectaron y herbori­zaron ejemplares de licofitas y helechos, que fueron identificados y depositados en el Herbario de la Universidad Autónoma Metropolitana-Iztapalapa (UAMIZ). La información generada se confrontó con la lista de especies reportadas en la literatura para la entidad, lo que permitió reconocer los nuevos registros. Resultados clave: Se documenta por primera vez para Puebla la presencia de 32 especies y un híbrido de licofitas y helechos, la mayoría de las cuales pertenecen a las familias Pteridaceae, Dryopteridaceae y Aspleniaceae, crecen en bosque mesófilo de montaña y vegetación derivada de bosque tropical perennifolio, entre 250 y 2500 m de altura. Conclusiones: Los nuevos registros incrementan de 335 a 367 el número de especies de licofitas y helechos que habitan en el estado de Puebla y ponen en evidencia la necesidad de continuar con el trabajo de exploración en la entidad.Background and Aims: There are few published floristic contributions about the lycophytes and ferns (pteridophytes) from Puebla, so it is considered very likely that the specific richness of this group in the state is greater than what has been documented currently. The goal of this paper is to document the new records of this plant group for the state, including information about their municipal and altitudinal distribution and the type of vegetation they inhabit. Methods: Between 2010 and 2018, several collection trips to different localities of the state of Puebla were made to collect specimens of lycophytes and ferns. The material was identified and deposited in the Herbarium of the Universidad Autónoma Metropolitana-Iztapalapa (UAMIZ). The information obtained was compared with the list of species of Puebla reported in the literature, allowing recognition of the new records. Key results: The presence of 32 species and a hybrid of lycophytes and ferns was documented for the first time for Puebla, most of which belong to the families Pteridaceae, Dryopteridaceae and Aspleniaceae, growing in cloud forest and vegetation derived from tropical evergreen forest, between elevations of 250 and 2500 m. Conclusions: The new records increase the number of species of lycophytes and ferns reported for Puebla from 335 to 367 and highlight the need to continue with the exploration and field work in the state

Control of trace metal distribution and variability in an interdunal wetland

Trace elements are serious pollutants in the natural environment and are of increasing concern due to the adverse effects at global scale. To refine the current understanding of trace metal distribution and variability in natural environments, concentrations of dissolved trace metals (Ag, Al, As, B, Ba, Be, Co, Cr, Cd, Cu, Fe, Hg, Mo, Ni, Pb, Sb, Se, Th,Tl, U, V, Mn, Zn), major ions, inorganic nutrients (NO3, PO4), TOC and stable isotopes of water were determined in water samples from rainwater, seven piezometers and a pond in the coastal Doñana wetland during four sampling campaigns between 2017 and 2019. Results show clear evaporation signatures of stable isotopes in the pond but not in the groundwater. Hydrochemical analyses yield significant, systematic changes in groundwater trace metal and nutrient composition along the flowpath from the dune belt to the pond, controlled by organic matter in the sediments. Whereas major ions reached maximum concentrations in the pond due to evapoconcentration, most trace metals showed highest concentrations at sites with lower redox levels, except for B, As and U, which showed very high concentrations in the pond. Cu, Zn, Ni, Sb and Tl yielded higher median concentrations in rainwater than in most of the groundwater points and in case of Cu and Zn higher even than in surface water which points to an atmospheric input source of these elements. Temporal variability of trace metals was related to lower hydraulic heads after an elongated dry period which led to lower redox levels and higher concentrations of most of the trace elements whereas major ions showed more constant concentration levels. This is of special concern regarding climate change and the predicted higher frequency of prolonged dry periods, which could modify the natural hydrochemical patterns in undisturbed wetlands systemsThis work has been financed by the CLIGRO Project (MICINN, CGL2016-77473-C3-1-R) of the Spanish National Plan for Scientific and Technical Research and Innovation. The infrastructure has been cofinanced by European Research Funds (SE Scientific Infrastructures and Techniques and Equipment 388 2013, IGME13-1E-2113). We are especially grateful for the technical support of Lidia Molano Leno and Daniel Jesus Martinez Suárez. The contracts of Lidia Molano Leno (PEJ-2014-A-68763) and Daniel Jesus Martinez Suárez (PTA2014-09579-I) were financed by the Ministry of Economy, Industry and Competitiveness of Spain (MINECO) and co-financed by the European Investment Bank (EIB) and the European Social Fund (ESF). The contract of Carmen Serrano Hidalgo was funded by the Industrial PhD grant supported by the Autonomous Region of Madrid, Spain (IND2018/AMB-9553). This work is also a contribution to the Andalusian research groups RNM-308 (Group of Hydrogeology) and RNM-126 (Group of water resources), the Lower Guadalquivir Basin convention between the CN IGME CSIC and Confederación Hidrológica del Guadalquivir (CHG) as well as the convention between Pablo de Olavide University and the Guadalquivir River Basin Board (Hydrological monitoring and modeling in Doñana temporary ponds

Development of High-Specificity Fluorescent Probes to Enable Cannabinoid Type 2 Receptor Studies in Living Cells.

Pharmacological modulation of cannabinoid type 2 receptor (CB2R) holds promise for the treatment of numerous conditions, including inflammatory diseases, autoimmune disorders, pain, and cancer. Despite the significance of this receptor, researchers lack reliable tools to address questions concerning the expression and complex mechanism of CB2R signaling, especially in cell-type and tissue-dependent contexts. Herein, we report for the first time a versatile ligand platform for the modular design of a collection of highly specific CB2R fluorescent probes, used successfully across applications, species, and cell types. These include flow cytometry of endogenously expressing cells, real-time confocal microscopy of mouse splenocytes and human macrophages, as well as FRET-based kinetic and equilibrium binding assays. High CB2R specificity was demonstrated by competition experiments in living cells expressing CB2R at native levels. The probes were effectively applied to FACS analysis of microglial cells derived from a mouse model relevant to Alzheimer’s disease.pre-print2,41 M

Relativistic effects on the nuclear magnetic shielding tensor

A new approach for calculating relativistic corrections to the nuclear magnetic shieldings is presented. Starting from a full relativistic second order perturbation theory expression a two-component formalism is constructed by transforming matrix elements using the elimination of small component scheme and separating out the contributions from the no-virtual pair and the virtual pair part of the second order corrections to the energy. In this way we avoid a strong simplification used previously in the literature. We arrive at final expressions for the relativistic corrections which are equivalent to those of Fukui et al. J. Chem Phys. 105, 3175 (1996) and at some other additional terms correcting both the paramagnetic and the diamagnetic part of the nuclear magnetic shielding. Results for some relativistic corrections to the shieldings of the heavy and light nuclei in HX and CHȝX (X=Br,I) at both random phase and second order polarization propagator approach levels are given.Fil: Melo, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Ruiz de Azua, Martín César. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Giribet, Claudia Gloria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Aucar, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; ArgentinaFil: Romero, Rodolfo Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; Argentin

Current state of dental autotransplantation

The aim of this study is to analyse the current situation in dental autotransplantations within the different therapeutic alternatives that the dentist has available to replace a tooth in the dental arcade. For some authors this is an option headed for failure, whereas for others, it is an alternative to keep in mind. In this study we analyse the factors related to the predictability of the technique, based on an analysis of research work published in the scientific literature up to date. We also present two clinical cases performed by our team and their subsequent evaluation. In spite of the satisfactory results seen when reviewing the existing literature, we cannot say that dental autotransplantation is currently the technique of choice when a tooth is lost, given the predictability of osteointegrated implants. © Medicina Oral S. L