Late Jurassic (Kimmeridgian) larger foraminifera from Santiago Coatepec, SE Puebla, Mexico

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Uso del conocimiento estadístico en egresados de psicología educativa de la Universidad Pedagógica Nacional

En este trabajo se describe el uso que hacen del conocimiento estadístico egresados de Psicología Educativa de la Universidad Pedagógica Nacional cuando realizan su trabajo de tesis o tesina para obtener el grado. Se llevó a cabo la revisión de los 221 trabajos realizados de 1995 a 2004. En los resultados se observa que, en general, los tesistas utilizaron los análisis estadísticos cuando su investigación lo requirió; no obstante, en un alto porcentaje la prueba estadística elegida fue inadecuada. Finalmente se concluye la necesidad de discutir la pertinencia de los contenidos, estrategias y procedimientos de instrucción y evaluación de los cursos de estadística, así mismo la reflexión acerca de cuántos cursos debe haber, en qué momento de la formación de los estudiantes

Microcausality and quantum cylindrical gravitational waves

We study several issues related to the different choices of time available for the classical and quantum treatment of linearly polarized cylindrical gravitational waves. We pay special attention to the time evolution of creation and annihilation operators and the definition of Fock spaces for the different choices of time involved. We also discuss the issue of microcausality and the use of field commutators to extract information about the causal properties of quantum spacetime. © 2003 The American Physical Society.The authors wish to thank A. Ashtekar, G. Date, and L. Garay for interesting discussions. They are especially grateful to M. Varadarajan for suggesting the subject and sharing enlightening conversations and insight. E.J.S.V. is supported by the Spanish Ministry of Education and Culture co- financed by the European Social Fund. This work was supported by the Spanish MCYT under the research projects BFM2001-0213 and BFM2002-04031-C02-02.Peer Reviewe

Concepto jurídico de secta

Ponencia presentada al III Congreso Interuniversitario de Derecho Eclesiástico para estudiantes celebrado en Córdoba, del 21 al 24 de abril de 199

On-shell equivalence of general relativity and Holst theories with nonmetricity, torsion, and boundaries

We study a generalization of the Holst action where we admit nonmetricity and torsion in manifolds with timelike boundaries (both in the metric and tetrad formalism). We prove that its space of solutions is equal to the one of the Palatini action. Therefore, we conclude that the metric sector is in fact identical to general relativity (GR), which is defined by the Einstein-Hilbert action. We further prove that, despite defining the same space of solutions, the Palatini and (the generalized) Holst Lagrangians are not cohomologically equal. Thus, the presymplectic structure and charges provided by the covariant phase space method might differ. However, using the relative bicomplex framework, we show the covariant phase spaces of both theories are equivalent (and in fact equivalent to GR), as well as their charges, clarifying some open problems regarding dual charges and their equivalence in different formulations.This work has been supported by the Spanish Ministerio de Ciencia Innovación y Universidades-Agencia Estatal de Investigación FIS2017-84440-C2-2-P and PID2020-116567GB-C22 grants. Juan Margalef-Bentabol is supported by the AARMS postdoctoral fellowship, by the NSERC Discovery Grant No. 2018-04873, and the NSERC Grant RGPIN-2018-04887. E.J.S. Villaseñor is supported by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M23), and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation)

Efecto alelopático de la invasora Acacia dealbata Link (Fabaceae) en dos especies de plantas nativas del centro-sur de Chile

Plant species that growth close to or under the canopy of Acacia dealbata Link (Fabaceae, subfamily: Mimosoideae) withinits non-native range, survive with difficulty or not at all, especially if they are native. This phenomenon has been attributedto allelopathy; one of the strategies used by A. dealbata to trigger an invasion process. Native species Quillaja saponariaMolina (tree) and Helenium aromaticum (Hook.) H.L. Bailey (herb), share A. dealbata’s range in South-central Chile. Thisstudy was performed on the Mediterranean Biobío Region of Chile. We evaluated the effect of leaves, flowers, pods andseeds of A. dealbata on the germination and early growth of these native species. Biological assays were carried out underlaboratory conditions, based on aqueous extracts and the direct effect of plant material. Leaf litter prevented the germinationof both species and seeds of the invasive species impeded the germination of Q. saponaria. Other plant parts from A.dealbata also induced reductions of hypocotyl and radicle lengths in the native species, reaching over 50 % in some treatmentvalues. All plant parts caused radicle necrosis, preventing the formation of root hairs and, consequently, jeopardizing thesurvival possibility of the recipient species. The results show that A. dealbata can interfere with the establishment of pioneerherbaceous species in ecological succession and can also affect trees if they are reached by the invasion front.Las plantas que crecen cerca o bajo el dosel de Acacia dealbata Link (Fabaceae, subfamilia: Mimosoideae), cuando esta seencuentra en el rango no nativo, sobreviven con dificultad o no lo logran, especialmente si son nativas. Este fenómeno se haatribuido a la alelopatía; una de las estrategias utilizadas por A. dealbata para promover su proceso de invasión. Las especiesnativas Quillaja saponaria Molina (arbórea) y Helenium aromaticum (Hook.) H.L. Bailey (herbácea) comparten el rango dedistribución de A. dealbata en el centro-sur de Chile. El presente trabajo se realizó en la Región del Biobío y se evaluaronlos efectos de hojas, flores, vainas y semillas de A. dealbata en la germinación y crecimiento temprano de las especiesnativas mencionadas. Los ensayos biológicos se llevaron a cabo en condiciones de laboratorio, basados en extractos acuososy efectos directos del material vegetal. Nuestros resultados indicaron que las hojas impidieron la germinación de ambasespecies nativas, pero las semillas impidieron sólo la germinación de Q. saponaria. Otras partes de la planta de A. dealbatatambién indujeron fuertes reducciones de las longitudes del hipocótilo y radícula en las especies nativas, superándose el50% en algunos tratamientos. Todas las partes de la planta causaron necrosis en la radícula, evitando la formación de pelosradicales y, por consiguiente, comprometiendo la posibilidad de supervivencia de las especies receptoras. Estos resultadosmuestran que A. dealbata puede interferir en el establecimiento de especies herbáceas pioneras en la sucesión ecológica ytambién puede afectar especies arbóreas secundarias si son alcanzadas por el frente de invasión

Hamiltonian Gotay-Nester-Hinds analysis of the parametrized unimodular extension of the Holst action

We give a detailed account of the Hamiltonian Gotay-Nester-Hinds (GNH) analysis of the parametrized unimodular extension of the Holst action. The purpose of the paper is to derive, through the clear geometric picture furnished by the GNH method, a simple Hamiltonian formulation for this model and explain why it is difficult to arrive at it in other approaches. We will also show how to take advantage of the field equations to anticipate the simple form of the constraints that we find in the paper.This work has been supported by the Spanish Ministerio de Ciencia Innovación y Universidades-Agencia Estatal de Investigación/FIS2017-84440-C2-2-P grant. Bogar Díaz was partially supported by a DGAPA-UNAM postdoctoral fellowship and acknowledges support from the CONEX-Plus program funded by Universidad Carlos III de Madrid and the European Union’s Horizon 2020 program under the Marie Sklodowska-Curie grant agreement No. 801538. Juan Margalef-Bentabol is supported by the Eberly Research Funds of Penn State, by the NSFgrant PHY-1806356 and by the Urania Stott fund of Pittsburgh foundation UN2017-92945