Lower bounds for the number of limit cycles of trigonometric Abel equations

"Vegeu el resum a l'inici del document del fitxer adjunt"

On the depth of blowup algebras of ideals with analytic deviation one

Let I be an ideal in a local Cohen-Macaulay ring (A, m). Assume I to be generically a complete intersection of positive height. We compute the depth of the Rees algebra and the form ring of I when the analytic deviation of I equals one and its reduction number is also at most one. The formu- las we obtain coincide with the already known formulas for almost complete intersection ideals.

Characterization of larval moulting cycles in Maja brachydactyla (Brachyura, Majidae) reared in the laboratory

The moulting cycles of all larval instars (zoea I, zoea II, and megalopa) of the spider crab Maja brachydactyla Balss 1922 were studied in laboratory rearing experiments. Morphological changes in the epidermis and cuticle were photographically documented in daily intervals and assigned to successive stages of the moulting cycle (based on Drach's classification system). Our moult-stage characterizations are based on microscopical examination of integumental modifications mainly in the telson, using epidermal condensation, the degree of epidermal retraction (apolysis), and morphogenesis (mainly setagenesis) as criteria. In the zoea II and megalopa, the formation of new setae was also observed in larval appendages including the antenna, maxillule, maxilla, second maxilliped, pleopods, and uropods. As principal stages within the zoea I moulting cycle, we describe postmoult (Drach's stages A–B combined), intermoult (C), and premoult (D), the latter with three substages (D0, D1, and D2). In the zoea II and megalopa, D0 and D1 had to be combined, because morphogenesis (the main characteristic of D1) was unclear in the telson and did not occur synchronically in different appendices. The knowledge of the course and time scale of successive moult-cycle events can be used as a tool for the evaluation of the developmental state within individual larval instars, providing a morphological reference system for physiological and biochemical studies related to crab aquaculture.

The Brauer group and the second Abel-Jacobi map for 0-cycles on algebraic varieties

This paper focuses on the connection between the Brauer group and the 0-cycles of an algebraic variety. We give an alternative construction of the second l-adic Abel-Jacobi map for such cycles, linked to the algebraic geometry of Severi-Brauer varieties on X. This allows us then to relate this Abel-Jacobi map to the standard pairing between 0-cycles and Brauer groups (see [M], [L]), completing results from [M] in this direction. Second, for surfaces, it allows us to present this map according to the more geometrical approach devised by M. Green in the framework of (arithmetic) mixed Hodge structures (see [G]). Needless to say, this paper owes much to the work of U. Jannsen and, especially, to his recently published older letter [J4] to B. Gross.

Marine and transitional Middle/Upper Eocenen units of the Southeastern Pyrenean Foreland Basin (NE Spain)

The stratigraphic basis of this work has allowed the use of larger foraminifers in the biostratigraphic characterisation of the new Shallow Benthic Zones (SBZ). This part of the volume presents a description of the sedimentary cycles formed by the transgressive-regressive systems of the Lutetian and Bartonian in the southeastern sector of the Ebro Foreland Basin. Concerning the Lutetian deposits studied in the Amer-Vic and Empordà areas, four sedimentary cycles have been characterised. The first and second are found within the Tavertet/Girona Limestone Formation (Reguant, 1967; Pallí, 1972), while the third and fourth cycles cover the Coll de Malla Marl Formation (Clavell et al., 1970), the Bracons Formation (Gich, 1969, 1972), the Banyoles Marl Formation (Almela and Ríos, 1943), and the Bellmunt Formation (Gich, 1969, 1972). In the Bartonian deposits studied in the Igualada area, two transgressive-regressive sedimentary cycles have been characterised in the Collbàs Formation (Ferrer, 1971), the Igualada Formation (Ferrer, 1971), and the Tossa Formation (Ferrer, 1971). The Shallow Benthic Zones (SBZs) recognised within the Lutetian are the following: SBZ 13, from the Early Lutetian, in the transgressive system of the first cycle; SBZ 14, from the Middle Lutetian, in the second cycle and the lower part of the transgressive system of the third cycle; SBZ 15, from the Middle Lutetian, in the remaining parts of the third system; SBZ 16, from the Late Lutetian, throughout the fourth cycle. The association of larger foraminifers in the first and second cycles of the Bartonian in the Igualada area has been used as the basis for the definition of SBZs 17 and 18 recognised in the Bartonian of the western Tethys.

Self-similarity of complex networks and hidden metric spaces

We demonstrate that the self-similarity of some scale-free networks with respect to a simple degree-thresholding renormalization scheme finds a natural interpretation in the assumption that network nodes exist in hidden metric spaces. Clustering, i.e., cycles of length three, plays a crucial role in this framework as a topological reflection of the triangle inequality in the hidden geometry. We prove that a class of hidden variable models with underlying metric spaces are able to accurately reproduce the self-similarity properties that we measured in the real networks. Our findings indicate that hidden geometries underlying these real networks are a plausible explanation for their observed topologies and, in particular, for their self-similarity with respect to the degree-based renormalization.

On the configuration of Herman rings of meromorphic functions

We prove some results concerning the possible configuration s of Herman rings for transcendental meromorphic functions. We show that one pole is enough to obtain cycles of Herman rings of arbitrary period a nd give a sufficient condition for a configuration to be realizable.

Marine and transitional Middle/Upper Eocenen units of the Southeastern Pyrenean Foreland Basin (NE Spain)

The stratigraphic basis of this work has allowed the use of larger foraminifers in the biostratigraphic characterisation of the new Shallow Benthic Zones (SBZ). This part of the volume presents a description of the sedimentary cycles formed by the transgressive-regressive systems of the Lutetian and Bartonian in the southeastern sector of the Ebro Foreland Basin. Concerning the Lutetian deposits studied in the Amer-Vic and Empordà areas, four sedimentary cycles have been characterised. The first and second are found within the Tavertet/Girona Limestone Formation (Reguant, 1967; Pallí, 1972), while the third and fourth cycles cover the Coll de Malla Marl Formation (Clavell et al., 1970), the Bracons Formation (Gich, 1969, 1972), the Banyoles Marl Formation (Almela and Ríos, 1943), and the Bellmunt Formation (Gich, 1969, 1972). In the Bartonian deposits studied in the Igualada area, two transgressive-regressive sedimentary cycles have been characterised in the Collbàs Formation (Ferrer, 1971), the Igualada Formation (Ferrer, 1971), and the Tossa Formation (Ferrer, 1971). The Shallow Benthic Zones (SBZs) recognised within the Lutetian are the following: SBZ 13, from the Early Lutetian, in the transgressive system of the first cycle; SBZ 14, from the Middle Lutetian, in the second cycle and the lower part of the transgressive system of the third cycle; SBZ 15, from the Middle Lutetian, in the remaining parts of the third system; SBZ 16, from the Late Lutetian, throughout the fourth cycle. The association of larger foraminifers in the first and second cycles of the Bartonian in the Igualada area has been used as the basis for the definition of SBZs 17 and 18 recognised in the Bartonian of the western Tethys.

Quantitative developmental response to the length of exposure to long photoperiod in wheat and barley

The present study was designed to analyse the effect of the length of exposure to a long photoperiod imposed c. 3 weeks after sowing in spring wheat (cv. UQ189) and barley (cv. Arapiles) to (i) establish whether the response to the number of cycles of exposure is quantitative or qualitative, (ii) determine the existence of a commitment to particular stages well before the stage has been observable, and (iii) study the interrelationships between the effects on final leaf number and phyllochron when the stimulus is provided several days after seedling emergence. Both wheat and barley seemed to respond quantitatively to the number of long-day cycles they were exposed to. However, wheat showed a requirement of approximately 4 long-day cycles to be able to produce a significant response in time to heading. The barley cultivar used in the study was responsive to the minimum length of exposure. The response to extended photoperiod cycles during the stem elongation phase was due to the ‘ memory’ photoperiod effects being related, in the case of wheat, to the fact that the pre-terminal spikelet appearance phase saturated its photoperiod response well before that stage was reached. Therefore, the commitment to the terminal spikelet appearance in wheat may be reached well before this stage could be recognized. As the response in duration to heading exceeded that of the final leaf number, and the stem elongation phase responded to memory effects of photoperiod, the phyllochron of both cereals was responsive to the treatments accelerating the average phyllochron when exposed to longer periods of long days. The response in average phyllochron was due to a switch from bi-linear to linear models of leaf number v. time when the conditions were increasingly inductive, with the phyllochron of the initial (6–8) leaves being similar for all treatments (within each species), and from then on increased.

Valor pronóstico de la densidad microvascular y de la expresión del VEGF, EGFR y HIF-1 en pacientes con cáncer de cérvix localmente avanzado tratados con quimioradiación

Introducción: Colombia cuenta con poca información sobre el comportamiento del cáncer, no obstante, el carcinoma de cuello uterino representa la segunda causa de muerte por la enfermedad entre las mujeres de nuestro entorno. El patrón epidemiológico de la enfermedad es preocupante porque los estados localmente avanzados constituyen el estado más frecuente al momento del diagnóstico y la mortalidad siendo bastante alta a pesar de la presencia de un programa de cribado organizado. Objetivo: Describir el valor pronóstico de la densidad microvascular (DMV) y de la expresión proteica de varios genes relacionados con la supervivencia y proliferación del cáncer de cérvix localmente avanzado en un grupo de mujeres tratadas con quimioradiación y braquiterapia intracavitaria. Se estimaron la tasa de respuesta global (TRG), la supervivencia libre de progresión (SLP) y la supervivencia global (SG). Resultados: Se incluyeron 61 mujeres con una edad media de 52 ± 10 años; todas tenían diagnóstico de cáncer de cérvix localmente avanzado (IIA 2.3%/IIB 47.5%/IIIA 4.9%/IIIB 37.7%/IVA 3.3%/no definido 3.3%), con un volumen tumoral promedio de 6.4cm (DE ± 1.8cm) e infección por VPH en 46% de los casos; 58 sujetos (95%) tenían un patrón escamoso, dos fueron adenocarcinomas y &50% presentaba neoplasias moderada o pobremente diferenciadas. Todas fueron tratadas con quimioradiación (interrupción transitoria en teleterapia por toxicidad y otras causas en 19% y 21.4%, respectivamente/media de ciclos de platino concomitante 4.8 series ± 1.0) y braquiterapia (77% completaron el tratamiento intracavitario). La mediana para la SLP y global fue de 6.6 meses (r, 4.0-9.1) y 30 meses (r, 11-48), respectivamente. Ninguna de las variables tuvo un efecto positivo sobre la SLP, mientras el análisis multivariado demostró que los niveles de expresión del VEGF (P=0.026), EGFR (P=0.030), y el volumen tumoral menor de 6 cm (P=0.02) influyeron positivamente sobre éste desenlace. Conclusión: Existe una influencia positiva sobre el pronóstico, de la tipificación en el cáncer de cérvix localmente avanzado tratado con quimioradiación basada en platino.

Els apareguts i el culte de les ànimes del Purgatori (segles XIV-XVII). Estudi i edició de textos catalans

Report for the scientific sojourn carried out at the Institut National d'Histoire de l'Art (INHA), France, from 2010 to 2012. It has focused on the analysis and editing of tales of human apparitions from the other world belonging to the Catalan culture or referring to it. We have studied and edited different versions of the process of Esperança Alegre (Lleida, 1500) and the Peregrinació del Venturós Pelegrí. These medieval works have been preserved in sources of the late sixteenth century or later. We have located a manuscript of the Esperança Alegre's tale, unknown to us at the beginning of this research (Biblioteca Nacional de España, ms. 1701), which differs from the version of ms. Baluze 238 of the Bibliothèque Nationale de France. The scribe of the ms. 1701 adds several paragraphs where considers the case as a diabolical phantasmagoria. About the Venturós Pelegrí, we have tried to establish firm criteria for the classification of many editions from the seventeenth to nineteenth centuries. We have been looking for printed books in the libràries of the world and we have made several requests for photographic reproductions, in order to classify undated editions by comparing woodcuts and other decorative elements. In the legend of Prince Charles of Viana (1421-1461), the appearances of his ghost are accompanied by rumors of his poisoning and of his sanctity. In addition, we have studied the cycles of masses for the souls in Purgatory linked to the hagiographies of St. Amadour and St. Vincent Ferrer, as well as the appearances described in L'Ànima d’Oliver of Francesc Moner, in the Carmelite chronicles of Father John of St. Joseph (1642-1718) and in some folktales collected from the eighteenth to the twentieth century. All this have allowed us to verify the evolution of certain cultural paradigms since the Middle Ages to the present.

Noves metodologies d’anàlisi de compostos volàtils mitjançant trampes d’agulla. Aplicació a l’anàlisi d’alè, atmosfèrica i d’aigües

New methodologies for the analysis of volatile compoundsusing needle traps. Applications to breath, atmospheric andwater analysis. A new preconcentration technique has been developed for the analysis of volatile compounds based on the use of needle traps. These traps are based on stainless steel needles filled with one or more adsorbents, which allows the preconcentration of the anilities inside the trap by passing a gas flow through the needle. The parameters affecting the sorption/desorption process have been assessed (e.g. needle and liner dimensions, injector temperature, split less time, memory effects, and stability inside the needle). For liquid samples, four different sampling methodologies were studied, including passive and active sampling methods. The best results, considering the simplicity and sensitivity, are obtained by sampling the headspace volume using various cycles of a small and fix volume. Once the best conditions of analysis have been found, the method has been validated for gas and liquid samples. The results obtained show that needle traps are a good analytical methodology for the analysis of breath, environmental and liquid samples

A survey on the inverse integrating factor

The relation between limit cycles of planar differential systems and the inverse integrating factor was first shown in an article of Giacomini, Llibre and Viano appeared in 1996. From that moment on, many research articles are devoted to the study of the properties of the inverse integrating factor and its relationwith limit cycles and their bifurcations. This paper is a summary of all the results about this topic. We include a list of references together with the corresponding related results aiming at being as much exhaustive as possible. The paper is, nonetheless, self-contained in such a way that all the main results on the inverse integrating factor are stated and a complete overview of the subject is given. Each section contains a different issue to which the inverse integrating factor plays a role: the integrability problem, relation with Lie symmetries, the center problem, vanishing set of an inverse integrating factor, bifurcation of limit cycles from either a period annulus or from a monodromic ω-limit set and some generalizations.