Estimation of dynamic latent variable models using simulated nonparametric moments

Given a model that can be simulated, conditional moments at a trial parameter value can be calculated with high accuracy by applying kernel smoothing methods to a long simulation. With such conditional moments in hand, standard method of moments techniques can be used to estimate the parameter. Since conditional moments are calculated using kernel smoothing rather than simple averaging, it is not necessary that the model be simulable subject to the conditioning information that is used to define the moment conditions. For this reason, the proposed estimator is applicable to general dynamic latent variable models. Monte Carlo results show that the estimator performs well in comparison to other estimators that have been proposed for estimation of general DLV models.

Diseño de filtros con topología apilada mediante resonadores FBAR

Els continguts de la memòria es divideixen en dues parts fonamentals, precedides d’una breu explicació on s’introdueix al lector en el tema; primer s’exposen les bases d’un ressonador simple FBAR, d’on s’obtenen equacions de control vitals, i seguidament es plantegen les bases per a un ressonador apilat SCR, derivades de l’estudi previ d’un ressonador simple. La primera part fonamental del treball es centra en l’anàlisi d’un ressonador SCR. Aquest anàlisi es recolza sobre el punt de vista teòric dels paràmetres imatge, el nostre punt de sortida. Aquesta primera part és la més teòrica: obtenció i aplicació dels paràmetres imatge i obtenció dels elements discrets que conformen el circuit equivalent SCR, una xarxa de dos ports. Posteriorment, s’analitza què succeeix modificant els valors dels elements discrets sense variar determinats paràmetres imatge i finalment, es proposa una aproximació per a controlar determinades especificacions de disseny, com són l’ample de banda de transmissió de la xarxa i el factor de qualitat, en funció de les modificacions dels elements discrets. En la segona part s’analitzen, de forma qualitativa, xarxes compostes per diferents ressonadors apilats connectats en cascada. Aquest segon estudi es divideix en dues subparts. En la primera connectem N ressonadors idèntics, plantegem algunes equacions de control i analitzem les respostes. En la segona, es planteja la connexió de dos (N=2) ressonadors diferents amb freqüències de ressonància properes. Aquest segon anàlisi es també totalment qualitatiu, però ens aporta informació que amb la unió de N ressonadors iguals no aconseguíem. Finalitzant aquesta segona part, es planteja l’optimització dels resultats obtinguts per a N=2, mitjançant estructures N=3 ressonadors.

Interleukin- 2 production during murine infection by Leishmania mexicana amazonensis

Highly susceptible BALB/c mice, resistant C57B1/6 and their F1 progeny (BDF1) were infected subcutaneously in the foot pad with Leishmania mexicana amazonenesis. At various times after infection, spleen or draining popliteal lymph node cells were assayed for their capacity to generate Interleukin-2 (I1-2) by Concanavalin A (ConA) stimulation. In both BALB/c and C57B1/6 strains there was a transient increase in their capacity to produce I1-2, from the 3rd to the 10th week post-infection. Return to pre-infection levels ocurred between 13th to 16th week post-infection in all three strains. BALB/c mice always produced higher titers of 11-2 than C57B1/6, but such differences were statistically significant only at 3 and 10 weeks post-infection. BDF1 mice had titers similar to those observed in BALB/c mice. I1-2 production by ConA-stimulated lymph node cells was lower as compared to the spleen, but with a similar pattern among the three mice strains. Our data show that susceptibility to infection by l. mexicana amazonenesis is not associated with deficient ConA-stimulated I1-2 production.

Fecundity, parity, and adult feeding relationships among Nyssorhynchus malaria vectors from Venezuela

Relative to their pre-engorgement weights, nulliparous Anopheles nuneztovari consumed significantly smaller blood meals than A. marajoara, A. triannulatus or A. aquasalis. When females were deprived of sugar before blood feeding, only one-quarter of A. nuneztovari, but more than two-thirds of A. marajoara, A. triannulatus and A. aquasalis matured eggs. Sugar feeding before blood, or two sucessive blood meals by sugar-deprived females, increased the proportion of nulliparous a. nuneztovari which developed eggs, but not significantly so. Nearly all individuals of nulliparous, sugar-fed A. marajoara, A. triannulatus and A. aquasalis matured eggs after one blood feeding. Among A. nuneztovari, A. marajoara and A. aquasalis that matured some eggs in the laboratory, there were no positive correlations between the number of eggs developed and relative vlood mealsize. However, blood meals larger than the mean size significantly increased the chance that A. nuneztovari would develop some eggs. Mean fecundities of gravid A. nuneztovari and A. marajoara reared in the laboratory were significantly lower than those of the same species captured at human bait in nature. Post-engorgement access to sugar by A. nuneztovari (captured at human bait) did not influence fecundity, but significantly enhanced survivorship and the proporticon of individuals which retained eggs. Release-recapture experiments revealed that relatively small blood meals are typical of A. nuneztovari only during the first gonotrophic cycle. We suggest that multiple blood feeding, seemingly necessary for most A. nuneztovari to develop a first clutch of eggs, may increase the probability of infection with Plasmodium vivax where this mosquito species is a primary vector.

Bilateral oligopoly and quantity competition

Bilateral oligopoly is a strategic market game with two commodities, allowing strategic behavior on both sides of the market. When the number of buyers is large, such a game approximates a game of quantity competition played by sellers. We present examples which show that this is not typically a Cournot game. Rather, we introduce an alternative game of quantity competition (the market share game) and, appealing to results in the literature on contests, show that this yields the same equilibria as the many-buyer limit of bilateral oligopoly, under standard assumptions on costs and preferences. We also show that the market share and Cournot games have the same equilibria if and only if the price elasticity of the latter is one. These results lead to necessary and sufficient conditions for the Cournot game to be a good approximation to bilateral oligopoly with many buyers and to an ordering of total output when they are not satisfied.

Health care utilization among immigrants and native-born populations in 11 European countries. Results from the Survey of Health, Ageing and Retirement in Europe

Objective: This study examines health care utilization of immigrants relative to the native-born populations aged 50 years and older in eleven European countries. Methods. We analyzed data from the Survey of Health Aging and Retirement in Europe (SHARE) from 2004 for a sample of 27,444 individuals in 11 European countries. Negative Binomial regression was conducted to examine the difference in number of doctor visits, visits to General Practitioners (GPs), and hospital stays between immigrants and the native-born individuals. Results: We find evidence those immigrants above age 50 use health services on average more than the native-born populations with the same characteristics. Our models show immigrants have between 6% and 27% more expected visits to the doctor, GP or hospital stays when compared to native-born populations in a number of European countries. Discussion: Elderly immigrant populations might be using health services more intensively due to cultural reasons.

Condensation of polyhedric structures onto soap films

We study the existence of solutions to general measure-minimization problems over topological classes that are stable under localized Lipschitz homotopy, including the standard Plateau problem without the need for restrictive assumptions such as orientability or even rectifiability of surfaces. In case of problems over an open and bounded domain we establish the existence of a “minimal candidate”, obtained as the limit for the local Hausdorff convergence of a minimizing sequence for which the measure is lower-semicontinuous. Although we do not give a way to control the topological constraint when taking limit yet— except for some examples of topological classes preserving local separation or for periodic two-dimensional sets — we prove that this candidate is an Almgren-minimal set. Thus, using regularity results such as Jean Taylor’s theorem, this could be a way to find solutions to the above minimization problems under a generic setup in arbitrary dimension and codimension.

Development of Leishmania (Viannia) braziliensis Vianna, 1911 in Lutzomyia intermedia (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae) under experimental conditions

The development of Leishmania (Viannia) braziliensis in experimentally infected Lutzomyia intermedia, showed colonization of the hindgut from 48h after the infective blood-meal, and the migration flagellates to the foregut, with a massive infection of the cardia at the 5th day post infection. Up to 10 days following the infective blood-meal, very few parasites were seen in the pharynx and cibarium. The role of L. intermedia as a vector of cutaneous leishmaniasis is discussed according to the estabilished criteria.

Discontinuous Galerkin methods for the one-dimensional Vlasov-Poisson system

We construct a new family of semi-discrete numerical schemes for the approximation of the one-dimensional periodic Vlasov-Poisson system. The methods are based on the coupling of discontinuous Galerkin approximation to the Vlasov equation and several finite element (conforming, non-conforming and mixed) approximations for the Poisson problem. We show optimal error estimates for the all proposed methods in the case of smooth compactly supported initial data. The issue of energy conservation is also analyzed for some of the methods.

Estimation of dynamic latent variable models using simulated nonparametric moments

Abstract. Given a model that can be simulated, conditional moments at a trial parameter value can be calculated with high accuracy by applying kernel smoothing methods to a long simulation. With such conditional moments in hand, standard method of moments techniques can be used to estimate the parameter. Because conditional moments are calculated using kernel smoothing rather than simple averaging, it is not necessary that the model be simulable subject to the conditioning information that is used to define the moment conditions. For this reason, the proposed estimator is applicable to general dynamic latent variable models. It is shown that as the number of simulations diverges, the estimator is consistent and a higher-order expansion reveals the stochastic difference between the infeasible GMM estimator based on the same moment conditions and the simulated version. In particular, we show how to adjust standard errors to account for the simulations. Monte Carlo results show how the estimator may be applied to a range of dynamic latent variable (DLV) models, and that it performs well in comparison to several other estimators that have been proposed for DLV models.

Metropolitan Areas in Spain and Italy

Metropolitan areas concentrate the main share of population, production and consumption in OECD countries. They are likely to be the most important units for economic, social and environmental analysis as well as for the development of policy strategies. However, one of the main problems that occur when adopting metropolitan areas as units of analysis and policy in European countries is the absence of widely accepted standards for identifying them. This severe problem appeared when we tried to perform comparative research between Spain and Italy using metropolitan areas as units of analysis. The aim of this paper is to identify metropolitan areas in Spain and Italy using similar methodologies. The results allow comparing the metropolitan realities of both countries as well as providing the metropolitan units that can be used in subsequent comparative researches. Two methodologies are proposed: the Cheshire-GEMACA methodology (FUR) and an iterative version of the USA-MSA algorithm, particularly adapted to deal with polycentric metropolitan areas (DMA). Both methods show a good approximation to the metropolitan reality and produce very similar results: 75 FUR and 67 DMA in Spain (75% of total population and employment), and 81 FUR and 86 DMA in Italy (70% of total population and employment).

Discontinuous Galerkin methods for the Multi-dimensional Vlasov-Poisson problem

We introduce and analyze two new semi-discrete numerical methods for the multi-dimensional Vlasov-Poisson system. The schemes are constructed by combing a discontinuous Galerkin approximation to the Vlasov equation together with a mixed finite element method for the Poisson problem. We show optimal error estimates in the case of smooth compactly supported initial data. We propose a scheme that preserves the total energy of the system.

WebQuest per a la Farmàcia Clínica i Atenció Farmacèutica : nova metodologia mitjançant moderna tecnologia

El projecte ha estat realitzat en la Unitat de Farmàcia Clínica i Farmacoteràpia de la Facultat de Farmàcia de la Universitat de Barcelona i ha estat a desenvolupar en dos anys. La finalitat del projecte ha estat oferir a l'alumne un material docent en suport digital, adaptat a una metodologia més creativa i de treball en grup, orientat a la millora de la seva formació, autonomia i rendiment acadèmic, en els aspectes relacionats amb la Farmàcia Clínica i Farmacoteràpia i l'Atenció Farmacèutica, i que consistirà en una primera aproximació a les directrius europees. Aquest material docent en suport digital són WebQuest (WQ) estructurades per temes i via Internet, la qual cosa possibilita un sistema dinàmic de fàcil retroalimentació i en constant actualització. Mitjançant la utilització d'aquest material docent es treballen aspectes com l'ús de metodologies docents centrades en l'alumne, autoaprenentatge a distància, aprenentatge seqüencial, treball en grup, participació activa i responsabilitat de l'alumne en el procés d'ensenyament aprenentatge i l'aproximació del mateix a la realitat professional entre altres, i tot això encaminat a promoure l'adaptació dels plans docents a l'Espai Europeu d'Educació Superior (EEES). En aquest sentit podem indicar que s'han elaborat cinc WQs, els títols del qual són Sistemes Personalitzats de Dosificació, Compliment terapèutic: el gran repte actual: informació al pacient, Compliment terapèutic: el gran repte actual: informació al professional sanitari, Dispensació activa en Diabetis mellitus tipus 2 i Dispensació activa en Hipertensión arterial. Cadascuna de les WQs elaborades consta dels apartats Introducció, Tasca, Procés, Recursos, Avaluació, Conclusió, Guia Didàctica i Crèdits. Les WQs estan allotjades en la pàgina web de la Unitat de Farmàcia Clínica i Farmacoteràpia, i a elles s'accedeix a través de l'adreça web http://www.ub.és/farcli/wp0.htm

A Preliminary Analysis of Insects of Medico-legal Importance in Curitiba, State of Paraná

A survey of the carrion fauna was made at two sites in Curitiba, State of Paraná, with the objective of describing the insects associated with carrion and setting up a preliminary data-base for medico-legal purposes in south Brazil. Vertebrate exclusion experiments were carried out in each season between 1994 and 1995 with a 250 g laboratory-bred rat (Rattus norvegicus). Five stages of decomposition were identified: fresh, bloated, decaying, dry and adipocere-like. Some species showed seasonal and site preference and so could be used to identify the probable place and season where death took place. Sarconesia chlorogaster (Diptera, Calliphoridae) was restricted to an open field site and to cooler months. Hemilucilia semidiaphana (Diptera, Calliphoridae) and Pattonella resona (Diptera, Sarcophagidae) were restricted to the forest site and warmer months. Phaenicia eximia (Diptera, Calliphoridae) and Oxyletrum discicolle (Coleoptera, Silphidae) were present at both sites throughout the year and could be useful for population level analysis. Dissochaetus murray (Coleoptera, Cholevidae) was present throughout the year at the forest site and was associated with the adipocere-like stage. Ants played an important role producing post-mortem injuries to the carcasses. Insects of 32 species are reported as being useful in community level approaches

Uncovering a role for micro-RNAs in sleep homeostasis and energy metabolism

Micro-RNAs (miRNAs) are key, post-transcriptional regulators of gene expression and have been implicated in almost every cellular process investigated thus far. However, their role in sleep, in particular the homeostatic aspect of sleep control, has received little attention. We here assessed the effects of sleep deprivation on the brain miRNA transcriptome in the mouse. Sleep deprivation affected miRNA expression in a brain-region specific manner. The forebrain expression of the miRNA miR-709 was affected the most and in situ analyses confirmed its robust increase throughout the brain, especially in the cerebral cortex and the hippocampus. The hippocampus was a major target of the sleep deprivation affecting 37 miRNAs compared to 52 in the whole forebrain. Moreover, independent from the sleep deprivation condition, miRNA expression was highly region-specific with 45% of all expressed miRNAs showing higher expression in hippocampus and 55% in cortex. Next we demonstrated that down-regulation of miRNAs in Com/c2o-expressing neurons of adult mice, through a conditional and inducible Dicer knockout mice model (cKO), results in an altered homeostatic response after sleep deprivation eight weeks following the tamoxifen-induced recombination. Dicer cKO mice showed a larger increase in the electro-encephalographic (EEG) marker of sleep pressure, EEG delta power, and a reduced Rapid Eye Movement sleep rebound, compared to controls, highlighting a functional role of miRNAs in sleep homeostasis. Beside a sleep phenotype, Dicer cKO mice developed an unexpected, severe obesity phenotype associated with hyperphagia and altered metabolism. Even more surprisingly, after reaching maximum body weight 5 weeks after tamoxifen injection, obese cKO mice spontaneously started losing weight as rapidly as it was gained. Brain transcriptome analyses in obese mice identified several obesity-related pathways (e.g. leptin, somatostatin, and nemo-like kinase signaling), as well as genes involved in feeding and appetite (e.g. Pmch, Neurotensin). A gene cluster with anti-correlated expression in the cerebral cortex of post-obese compared to obese mice was enriched for synaptic plasticity pathways. While other studies have identified a role for miRNAs in obesity, we here present a unique model that allows for the study of processes involved in reversing obesity. Moreover, our study identified the cortex as a brain area important for body weight homeostasis. Together, these observations strongly suggest a role for miRNAs in the maintenance of homeostatic processes in the mouse, and support the hypothesis of a tight relationship between sleep and metabolism at a molecular - Les micro-ARNS (miARNs) sont des régulateurs post-transcriptionnels de l'expression des gènes, impliqués dans la quasi-totalité des processus cellulaires. Cependant, leur rôle dans la régulation du sommeil, et en particulier dans le maintien de l'homéostasie du sommeil, n'a reçu que très peu d'attention jusqu'à présent. Dans cette étude, nous avons étudié les conséquences d'une privation de sommeil sur l'expression cérébrale des miARNs chez la souris, et observé des changements dans l'expression de nombreux miARNs. Dans le cerveau antérieur, miR-709 est le miARN le plus affecté par la perte de sommeil, en particulier dans le cortex cérébral et l'hippocampe. L'hippocampe est la région la plus touchée avec 37 miARNs changés comparés à 52 dans le cerveau entier. Par ailleurs, indépendamment de la privation de sommeil, certains miARNs sont spécifiquement enrichis dans certaines aires cérébrales, 45% des miARNs étant surexprimés dans l'hippocampe contre 55% dans le cortex. Dans une seconde étude, nous avons observé que la délétion de DICER, enzyme essentielle à la biosynthèse des miARNs, et la perte subséquente des miARNs dans les neurones exprimant la protéine CAMK2a altère la réponse homéostatique à une privation de sommeil, 8 semaines après l'induction de la recombinaison génétique par le tamoxifen. Les souris sans Dicer (cKO) ont une plus large augmentation de l'EEG delta power, le principal marqueur électro-encéphalographique du besoin de sommeil, comparée aux contrôles, ainsi qu'un rebond en sommeil paradoxal plus petit. De façon surprenante, les souris Dicer cKO développent une obésité rapide, sévère et transitoire, associée à de l'hyperphagie et une altération de leur métabolisme énergétique. Après avoir atteint un pic maximal d'obésité, les souris cKO entrent spontanément dans une période de perte de poids rapide. L'analyse du transcriptome cérébral des souris obèses nous a permis d'identifier des voies associées à l'obésité (leptine, somatostatine et nemo-like kinase), et à la prise alimentaire (Pmch, Neurotensin), tandis que celui des souris post-obèses a révélé un groupe de gènes liés à la plasticité synaptique. Au-delà des nombreux modèles d'obésité existant chez la souris, notre étude présente un modèle unique permettant d'étudier les mécanismes sous-jacent la perte de poids. De plus, nous avons mis en évidence un rôle important du cortex cérébral dans le maintien de la balance énergétique. En conclusion, toutes ces observations soutiennent l'idée que les miARNs sont des régulateurs cruciaux dans le maintien des processus homéostatiques et confortent l'hypothèse d'une étroite relation moléculaire entre le sommeil et le métabolisme.