On the Relationship between Market Power and Bank Risk Taking

We analyse risk-taking behaviour of banks in the context of spatial competition. Banks mobilise unsecured deposits by offering deposit rates, which they invest either in a prudent or a gambling asset. Limited liability along with high return of a successful gamble induce moral hazard at the bank level. We show that when the market power is low, banks invest in the gambling asset. On the other hand, for sufficiently high levels of market power, all banks choose the prudent asset to invest in. We further show that a merger of two neighboring banks increases the likelihood of prudent behaviour. Finally, introduction of a deposit insurance scheme exacerbates banks’ moral hazard problem.

Clúster creatius en entorns urbans: 22@Bcn i Shoreditch East London

La localització de les empreses de nova economia en zones urbanes, a pesar que el factor distància no sigui important, no deixa de ser considerable pels seus avantatges que els suposa estar situades conjuntament en relació amb les infraestructures, consum, beneficis socioculturals, i facilitat en les transaccions cara a cara. És inevitable que el primer quart del segle vint-i-un estigui lligat a l’economia creativa de forma similar amb que el començament del segle vint estava íntimament lligat a l’economia industrial i la invenció del sistema de producció en massa. La ciutat també va jugar un dels papers més importants per al desenvolupament de “la nova economia industrial” a les albors del segle vint, com ho és la ciutat del coneixement que acull “la nova economia creativa” al segle vint-i-un. És evident que els resultats morfològics, socials, econòmics i urbans són ben diferents en ambdós fenòmens, però l’impacte a les ciutats és molt gran. L’objectiu d’aquest estudi és analitzar els mecanismes d’aglomeració (clustering) d’activitats competitives basades en creació de coneixement i de serveis avançats que estan al darrera de desenvolupaments punters a ciutats com Barcelona, el projecte 22@bcn, i East London, el projecte Shoreditch. L’esforç que han posat les autoritats locals en crear l’entorn apropiat per atreure i crear empreses innovadores, com a motor de desenvolupament d’algunes ciutats modernes europees ha resultat en el sorgiment de nuclis o centres urbans molt dinàmics que suposadament estan preparats i acullen punts de creació de coneixement (“Urban Knowledge Hubs”), amb una demanda i llocs de treball altament qualificats. Aquest és el cas dels projectes de Barcelona (22@bcn) i East London (Shoreditch).

Trypanosomes of the subgenus Megatrypanum from armadillos (Xenarthra: Dasypodidae)

A new species of trypanosome, Trypanosoma (Megatrypanum) peba, is described from the peripheral blood of the armadillo Euphractus sexcinctus setosus from Bahia State, Brazil. Ten out of 29 specimens of the armadillo Dasypus novemcinctus from Pará State were found to have trypanosomes, including epimastigote forms, in impression smears of subcutaneous lymph nodes. The trypanosomes from D. novemcinctus are illustrated and were identified a idenrified as belonging to the subgenus Megatrypanum on the basis of their general appearance, although they failed to multiply is blood-agar culture medium and no bloodstream forms were seen. This is the first published record of trypanosomes of this subgenus from armdillos and the first demonstration of epimastigote trypanosomes in the mammalian host other than in the bloodstream, or in the anal glands of opssums.

CD28/CTLA4-B7 interaction is dispensable for T cell stimulation by mouse mammary tumor virus superantigen but not for B cell differentiation and virus dissemination.

B cells are the primary targets of infection for mouse mammary tumor virus (MMTV). However, for productive retroviral infection, T cell stimulation through the virally-encoded superantigen (SAG) is necessary. It activates B cells and leads to cell division and differentiation. To characterize the role of B cell differentiation for the MMTV life cycle, we studied the course of infection in transgenic mice deficient for CD28/CTLA4-B7 interactions (mCTLA4-H gamma 1 transgenic mice). B cell infection occurred in CTLA4-H gamma 1 transgenic mice as integrated proviral DNA could be detected in draining lymph node cells early after infection by polymerase chain reaction analysis. In mice expressing I-E, B cells were able to present the viral SAG efficiently to V beta 6+ T cells. These cells expanded specifically and were triggered to express the activation marker CD69. Further stages of progression of infection appeared to be defective. Kinetics experiments indicated that T and B cell stimulation stopped more rapidly than in control mice. B cells acquired an activated CD69+ phenotype, were induced to produce IgM but only partially switched to IgG secretion. Finally, the dissemination of infected cells to other lymph nodes and spleen was reduced and the peripheral deletion of V beta 6+ T cells was minimal. In contrast, in mice lacking I-E, T cell stimulation was also impaired and B cell activation undetectable. These data implicate B7-dependent cellular interactions for superantigenic T cell stimulation by low-affinity TCR ligands and suggest a role of B cell differentiation in viral dissemination and peripheral T cell deletion.

EEG-based functional brain networks: does the network size matter?

Functional connectivity in human brain can be represented as a network using electroencephalography (EEG) signals. These networks--whose nodes can vary from tens to hundreds--are characterized by neurobiologically meaningful graph theory metrics. This study investigates the degree to which various graph metrics depend upon the network size. To this end, EEGs from 32 normal subjects were recorded and functional networks of three different sizes were extracted. A state-space based method was used to calculate cross-correlation matrices between different brain regions. These correlation matrices were used to construct binary adjacency connectomes, which were assessed with regards to a number of graph metrics such as clustering coefficient, modularity, efficiency, economic efficiency, and assortativity. We showed that the estimates of these metrics significantly differ depending on the network size. Larger networks had higher efficiency, higher assortativity and lower modularity compared to those with smaller size and the same density. These findings indicate that the network size should be considered in any comparison of networks across studies.

Epidemiological and nosological aspects of Leishmania naiffi Lainson & Shaw, 1989

Leismania naiffi was isolated from 10 out of 64 armadillos (Dasypus novemcinctus) examined in Amazonas, Pará and Rondônia States in the Brazilian Amazon Region. The isolates were obtained in culture from samples of liver (3), spleen (3), lymph nodes (2), skin (1) and blood (1) from the infected animals. Heavy infections with the same parasite were detected for the first time in Psychodopygus squamiventris, a common man-biting phlebotomine, in amazonas and Pará. A new case of cutaneous leishmaniasis caused by L. naiffi is described from the Manaus area, making a total of three known cases of human infection by this parasite.

Deadlock avoidance with virtual channels

High Performance Computing is a rapidly evolving area of computer science which attends to solve complicated computational problems with the combination of computational nodes connected through high speed networks. This work concentrates on the networks problems that appear in such networks and specially focuses on the Deadlock problem that can decrease the efficiency of the communication or even destroy the balance and paralyze the network. Goal of this work is the Deadlock avoidance with the use of virtual channels, in the switches of the network where the problem appears. The deadlock avoidance assures that will not be loss of data inside network, having as result the increased latency of the served packets, due to the extra calculation that the switches have to make to apply the policy.

Análisis de rendimiento de aplicaciones paralelas de memoria compartida: problema N-body

Este trabajo analiza el rendimiento de cuatro nodos de cómputo multiprocesador de memoria compartida para resolver el problema N-body. Se paraleliza el algoritmo serie, y se codifica usando el lenguaje C extendido con OpenMP. El resultado son dos variantes que obedecen a dos criterios de optimización diferentes: minimizar los requisitos de memoria y minimizar el volumen de cómputo. Posteriormente, se realiza un proceso de análisis de las prestaciones del programa sobre los nodos de cómputo. Se modela el rendimiento de las variantes secuenciales y paralelas de la aplicación, y de los nodos de cómputo; se instrumentan y ejecutan los programas para obtener resultados en forma de varias métricas; finalmente se muestran e interpretan los resultados, proporcionando claves que explican ineficiencias y cuellos de botella en el rendimiento y posibles líneas de mejora. La experiencia de este estudio concreto ha permitido esbozar una incipiente metodología de análisis de rendimiento, identificación de problemas y sintonización de algoritmos a nodos de cómputo multiprocesador de memoria compartida.

Análisis y sintonización de aplicaciones paralelas/distribuidas de bioinformática: caso de estudio mpiBLAST

En termes de temps d'execució i ús de dades, les aplicacions paral·leles/distribuïdes poden tenir execucions variables, fins i tot quan s'empra el mateix conjunt de dades d'entrada. Existeixen certs aspectes de rendiment relacionats amb l'entorn que poden afectar dinàmicament el comportament de l'aplicació, tals com: la capacitat de la memòria, latència de la xarxa, el nombre de nodes, l'heterogeneïtat dels nodes, entre d'altres. És important considerar que l'aplicació pot executar-se en diferents configuracions de maquinari i el desenvolupador d'aplicacions no port garantir que els ajustaments de rendiment per a un sistema en particular continuïn essent vàlids per a d'altres configuracions. L'anàlisi dinàmica de les aplicacions ha demostrat ser el millor enfocament per a l'anàlisi del rendiment per dues raons principals. En primer lloc, ofereix una solució molt còmoda des del punt de vista dels desenvolupadors mentre que aquests dissenyen i evaluen les seves aplicacions paral·leles. En segon lloc, perquè s'adapta millor a l'aplicació durant l'execució. Aquest enfocament no requereix la intervenció de desenvolupadors o fins i tot l'accés al codi font de l'aplicació. S'analitza l'aplicació en temps real d'execució i es considra i analitza la recerca dels possibles colls d'ampolla i optimitzacions. Per a optimitzar l'execució de l'aplicació bioinformàtica mpiBLAST, vam analitzar el seu comportament per a identificar els paràmetres que intervenen en el rendiment d'ella, com ara: l'ús de la memòria, l'ús de la xarxa, patrons d'E/S, el sistema de fitxers emprat, l'arquitectura del processador, la grandària de la base de dades biològica, la grandària de la seqüència de consulta, la distribució de les seqüències dintre d'elles, el nombre de fragments de la base de dades i/o la granularitat dels treballs assignats a cada procés. El nostre objectiu és determinar quins d'aquests paràmetres tenen major impacte en el rendiment de les aplicacions i com ajustar-los dinàmicament per a millorar el rendiment de l'aplicació. Analitzant el rendiment de l'aplicació mpiBLAST hem trobat un conjunt de dades que identifiquen cert nivell de serial·lització dintre l'execució. Reconeixent l'impacte de la caracterització de les seqüències dintre de les diferents bases de dades i una relació entre la capacitat dels workers i la granularitat de la càrrega de treball actual, aquestes podrien ser sintonitzades dinàmicament. Altres millores també inclouen optimitzacions relacionades amb el sistema de fitxers paral·lel i la possibilitat d'execució en múltiples multinucli. La grandària de gra de treball està influenciat per factors com el tipus de base de dades, la grandària de la base de dades, i la relació entre grandària de la càrrega de treball i la capacitat dels treballadors.

The reasons for discrepancies in target volume delineation : a SASRO study on head-and-neck and prostate cancers.

PURPOSE: To understand the reasons for differences in the delineation of target volumes between physicians. MATERIAL AND METHODS: 18 Swiss radiooncology centers were invited to delineate volumes for one prostate and one head-and-neck case. In addition, a questionnaire was sent to evaluate the differences in the volume definition (GTV [gross tumor volume], CTV [clinical target volume], PTV [planning target volume]), the various estimated margins, and the nodes at risk. Coherence between drawn and stated margins by centers was calculated. The questionnaire also included a nonspecific series of questions regarding planning methods in each institution. RESULTS: Fairly large differences in the drawn volumes were seen between the centers in both cases and also in the definition of volumes. Correlation between drawn and stated margins was fair in the prostate case and poor in the head-and-neck case. The questionnaire revealed important differences in the planning methods between centers. CONCLUSION: These large differences could be explained by (1) a variable knowledge/interpretation of ICRU definitions, (2) variable interpretations of the potential microscopic extent, (3) difficulties in GTV identification, (4) differences in the concept, and (5) incoherence between theory (i.e., stated margins) and practice (i.e., drawn margins).

Seguretat en xarxes i aplicacions distribuïdes: MANET routing

L’objectiu del projecte és tractar de donar solució al problema d’interconnexió de dispositius mòbils, en concret de PDAs Nokia 810, en una situació on no es disposa d’un punt d’accès fixe. Per a fer-ho possible es forma una xarxa MANET, és a dir una xarxa Ad-hoc mòbil, on els nodes són els propis dispositius. Un cop establerta la connexió, s’obté un llistat actualitzat amb les adreces IP de tots els nodes visibles de la xarxa.

Keeping the leaves green above us.

The plant immune system relies to a great extent on the highly regulated expression of hundreds of defense genes encoding antimicrobial proteins, such as defensins, and antiherbivore proteins, such as lectins. The expression of many of these genes is controlled by a family of mediators known as jasmonates; these cyclic oxygenated fatty acid derivatives are reminiscent of prostaglandins. The roles of jasmonates also extend to the control of reproductive development. How are these complex events regulated? Nearly 20 members of the jasmonate family have been characterized. Some, like jasmonic acid, exist in unmodified forms, whereas others are conjugated to other lipids or to hydrophobic amino acids. Why do so many chemically different forms of these mediators exist, and do individual jasmonates have unique signaling properties or are they made to facilitate transport within and between cells? Key features of the jasmonate signal pathway have been identified and include the specific activation of E3-type ubiquitin ligases thought to target as-yet-undescribed transcriptional repressors for modification or destruction. Several classes of transcription factor are known to function in the jasmonate pathway, and, in some cases, these proteins provide nodes that integrate this network with other important defensive and developmental pathways. Progress in jasmonate research is now rapid, but large gaps in our knowledge exist. Aimed to keep pace with progress, the ensemble of jasmonate Connections Maps at the Signal Transduction Knowledge Environment describe (i) the canonical signaling pathway, (ii) the Arabidopsis signaling pathway, and (iii) the biogenesis and structures of the jasmonates themselves.

The analysis of approximate quickselect and related problems

Approximate Quickselect, a simple modification of the well known Quickselect algorithm for selection, can be used to efficiently find an element with rank k in a given range [i..j], out of n given elements. We study basic cost measures of Approximate Quickselect by computing exact and asymptotic results for the expected number of passes, comparisons and data moves during the execution of this algorithm. The key element appearing in the analysis of Approximate Quickselect is a trivariate recurrence that we solve in full generality. The general solution of the recurrence proves to be very useful, as it allows us to tackle several related problems, besides the analysis that originally motivated us. In particular, we have been able to carry out a precise analysis of the expected number of moves of the ith element when selecting the jth smallest element with standard Quickselect, where we are able to give both exact and asymptotic results. Moreover, we can apply our general results to obtain exact and asymptotic results for several parameters in binary search trees, namely the expected number of common ancestors of the nodes with rank i and j, the expected size of the subtree rooted at the least common ancestor of the nodes with rank i and j, and the expected distance between the nodes of ranks i and j.

Introduction and spreading of Biomphalaria straminea (Dunker, 1848) (Mollusca: Pulmonata: Planorbidae) in Guadeloupe, French West Indies

The finding in 1985 of a well-established population of Biomphalaria straminea in a pond in Grande Terre of Guadeloupe constitutes a new species record for the freshwater molluscan fauna of that island. The following years a rapid extension of the species was documented on Grande Terre and Marie Galante. However, it was never found in the neighboring island of Basse Terre. The invasion of the whole hydrographic system of this island by Melanoides tuberculata during the last decade and the current presence of well-established and dense populations of this snail may explain the failure of the colonization by B. straminea.

Theoretical aspects of graph models for MANETs

We survey the main theoretical aspects of models for Mobile Ad Hoc Networks (MANETs). We present theoretical characterizations of mobile network structural properties, different dynamic graph models of MANETs, and finally we give detailed summaries of a few selected articles. In particular, we focus on articles dealing with connectivity of mobile networks, and on articles which show that mobility can be used to propagate information between nodes of the network while at the same time maintaining small transmission distances, and thus saving energy.