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An Empirical Study of the Cyclical Effects of Monetary Policy in Spain (1977-97)

Dolado, Juan José; María-Dolores, Ramón
Fonte: Fundación SEPI Publicador: Fundación SEPI
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em /01/2001 Português
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In this paper, we provide empirical evidece for the Spanish economy, over the period 1977-97, on wether monetary policy shocks hav had different effects on real output growth depending on the state of the business cycle. To do so, we adopt an extension of Hamilton's (1989) Markow Switching Model, as recently proposed by García and Schaller (1995), where shocks to an interest rate policy rule followed by the Bank of Spain are allowed to affect both the growth rate of output and the transition probabilities of moving from one phase to another. The analysis is carried out both at the aggregate level and the sectorial level, with the aim of addressing the following questions: (i) Does monetary policy have the same effect regardless of the current phase of economic fluctuations?, (ii) Does monetary policy only have an incremental effect on output growth rate within a given state or does it also affect the probability of a state switch, and (iii) How do the aggregate and sectorial results compare?

Acquisition of Information and Share Prices: An Empirical Investigation of Cognitive Dissonance

ARGENTESI, Elena; LUETKEPOHL, Helmut; MOTTA, Massimo
Fonte: Wiley-Blackwell Publishing, Inc Publicador: Wiley-Blackwell Publishing, Inc
Tipo: Artigo de Revista Científica
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This paper deals with the determinants of agents' acquisition of information. Our econometric evidence shows that the general index of Italian share-prices and the series of Italy's financial newspaper sales are cointegrated, and the former series Granger-causes the latter, thereby giving support to the cognitive dissonance hypothesis: (non-professional) agents tend to buy the newspaper when share prices are high and not to buy it when share prices are low. Instead, we do not find support for the hypothesis that the agents acquire information in order to trade in the stock market: we find no relationship between quantities exchanged in the market and newspaper sales, nor between stock market volatility and newspaper sales.

Testing for the Cointegrating Rank of a Vector Autoregressive Process with Uncertain Deterministic Trend Term

DEMETRESCU, Matei; LUETKEPOHL, Helmut; SAIKKONEN, Pentti
Fonte: European University Institute Publicador: European University Institute
Tipo: Trabalho em Andamento Formato: application/pdf
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When applying Johansen's procedure for determining the coin- tegrating rank to systems of variables with linear deterministic trends, there are two possible tests to choose from. One test allows for a trend in the cointegration relations and the other one restricts the trend to be orthogonal to the cointegration relations. The first test is known to have reduced power relative to the second one if there is in fact no trend in the cointegration re- lations, whereas the second one is based on a misspecified model if the linear trend is not orthogonal to the cointegration relations. Hence, the treatment of the linear trend term is crucial for the outcome of the rank determination procedure. We compare two alternative testing strategies which are appli- cable if there is uncertainty regarding the proper trend specification. In the first one a specific cointegrating rank is rejected if one of the two tests rejects and in the second one the trend term is decided upon by a pretest. The first strategy is shown to be preferable in applied work.

The cabinet: containing a collection of curious papers, relative to the present political contests in Ireland; some of which are now first published. Viz. The Earl of K----e's memorial. Barrack resolutions. Commons address to the King in 1752 ..

Fonte: Quens University Publicador: Quens University
Tipo: Livro Formato: 5109427 bytes; application/pdf
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Genetic similarity in a hybrid population of 'Montenegrina' and 'King' mandarins

Brugnara,Eduardo Cesar; Bastianel,Marinês; Weiler,Roberto Luis; Schwarz,Sergio Francisco
Fonte: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira Publicador: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2012 Português
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The objective of this work was to confirm the hybrids obtained in plants originated from the crossing between the mandarins Citrus deliciosa 'Montenegrina' and C. nobilis 'King', and to estimate the genetic similarity among hybrids, and between each hybrid and its parents. Twenty‑three pairs of microsatellite primers were tested. Fourteen of these pairs showed polymorphic bands between parents. Primers CCSM 129 and CCSME 52 were sufficient to identify the 12 nucellar clones observed in the studied population. Genetic similarity analysis of the population (hybrids and parents) showed 0.56 average similarity. Besides the 12 clones of 'Montenegrina' identified, 25 hybrids were found of which D18, C32, D06, C05 and D09 are the more similar to 'Montenegrina'.

Parasite virulence factors during falciparum malaria: rosetting, cytoadherence, and modulation of cytoadherence by cytokines.

Ringwald, P; Peyron, F; Lepers, J P; Rabarison, P; Rakotomalala, C; Razanamparany, M; Rabodonirina, M; Roux, J; Le Bras, J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1993 Português
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To determine virulence factors of isolates of Plasmodium falciparum and the potential role of cytokines in cerebral malaria, 46 Malagasy patients presenting with cerebral (n = 10), severe (n = 10), and uncomplicated (n = 26) malaria were enrolled in a study. The capacity of 21 of 46 P. falciparum isolates to form rosettes in vitro and to adhere to human umbilical vein endothelial cells (HUVECs) that express intercellular adhesion molecule-1 receptors and to C32 amelanotic melanoma cells that express mainly CD36 receptors was investigated together with the effects of tumor necrosis factor alpha (TNF-alpha), granulocyte macrophage-colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-6 alone and in two-by-two combinations on the cytoadherence of infected erythrocytes to HUVECs. Plasma levels of these cytokines were also measured in the patients at admission. The percentage of rosette formation was higher for the isolates from patients with cerebral (n = 6; 19.5%) and severe (n = 6; 30.5%) malaria than for those from patients with uncomplicated malaria (n = 9; 5%) (P < 0.002). The cytoadherence properties of the isolates did not differ among the three groups whatever the target cell used, but adherence to melanoma cells was systematically higher than that to HUVECs. Adhesion to HUVECs was increased more after TNF-alpha stimulation than after GM-CSF...

Nonspecific immunostimulant activities of synthetic trehalose-6,6'-diesters (lower homologs of cord factor).

Parant, M; Audibert, F; Parant, F; Chedid, L; Soler, E; Polonsky, J; Lederer, E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1978 Português
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Mycobacterial cord factors (6,6'-diesters of trehalose with mycolic acids ranging from C80 to C90) have been shown to protect mice effectively against infection with Klebsiella pneumoniae or with Listeria monocytogenes. Our present findings indicate that the low-molecular-weight cord factor of Corynebacterium diphtheriae (with corynomycolic acids ranging from C28 PTO C36) is equally active. Moreover, its synthetic analog (with synthetic C32 mycolic acid) has the same activity. Two lower synthetic 6,6'-diesters of trehalose with C22 acids, which are described here for the first time, as well as dipalmitate and a dioleate of sucrose, were found inactive. The synthetic C76 trehalose diesters, which are capable of enhancing nonspecific resistance to infection, increase the immune response in mice, even when injected in metabolizable oil. They induce in the injected paws an inflammatory process weaker and more transient than the natural cord factor.

Hints on the evolutionary design of a dimeric RNase with special bioactions.

Di Donato, A.; Cafaro, V.; Romeo, I.; D'Alessio, G.
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /08/1995 Português
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Residues P19, L28, C31, and C32 have been implicated (Di Donato A, Cafaro V, D'Alessio G, 1994, J Biol Chem 269:17394-17396; Mazzarella L, Vitagliano L, Zagari A, 1995, Proc Natl Acad Sci USA: forthcoming) with key roles in determining the dimeric structure and the N-terminal domain swapping of seminal RNase. In an attempt to have a clearer understanding of the structural and functional significance of these residues in seminal RNase, a series of mutants of pancreatic RNase A was constructed in which one or more of the four residues were introduced into RNase A. The RNase mutants were examined for: (1) the ability to form dimers; (2) the capacity to exchange their N-terminal domains; (3) resistance to selective cleavage by subtilisin; and (4) antitumor activity. The experiments demonstrated that: (1) the presence of intersubunit disulfides is both necessary and sufficient for engendering a stably dimeric RNase; (2) all four residues play a role in determining the exchange of N-terminal domains; (3) the exchange is the molecular basis for the RNase antitumor action; and (4) this exchange is not a prerequisite in an evolutionary mechanism for the generation of dimeric RNases.

A domain of the actin binding protein Abp140 is the yeast methyltransferase responsible for 3-methylcytidine modification in the tRNA anti-codon loop

D'Silva, Sonia; Haider, Steffen J.; Phizicky, Eric M.
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /06/2011 Português
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The 3-methylcytidine (m3C) modification is widely found in eukaryotic species of tRNASer, tRNAThr, and tRNAArg; at residue 32 in the anti-codon loop; and at residue e2 in the variable stem of tRNASer. Little is known about the function of this modification or about the specificity of the corresponding methyltransferase, since the gene has not been identified. We have used a primer extension assay to screen a battery of methyltransferase candidate knockout strains in the yeast Saccharomyces cerevisiae, and find that tRNAThr(IGU) from abp140-Δ strains lacks m3C. Curiously, Abp140p is composed of a poorly conserved N-terminal ORF fused by a programed +1 frameshift in budding yeasts to a C-terminal ORF containing an S-adenosylmethionine (SAM) domain that is highly conserved among eukaryotes. We show that ABP140 is required for m3C modification of substrate tRNAs, since primer extension is similarly affected for all tRNA species expected to have m3C and since quantitative analysis shows explicitly that tRNAThr(IGU) from an abp140-Δ strain lacks m3C. We also show that Abp140p (now named Trm140p) purified after expression in yeast or Escherichia coli has m3C methyltransferase activity, which is specific for tRNAThr(IGU) and not tRNAPhe and occurs specifically at C32. We suggest that the C-terminal ORF of Trm140p is necessary and sufficient for activity in vivo and in vitro...

Transport of an Mr approximately 300,000 Plasmodium falciparum protein (Pf EMP 2) from the intraerythrocytic asexual parasite to the cytoplasmic face of the host cell membrane

Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/05/1987 Português
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The profound changes in the morphology, antigenicity, and functional properties of the host erythrocyte membrane induced by intraerythrocytic parasites of the human malaria Plasmodium falciparum are poorly understood at the molecular level. We have used mouse mAbs to identify a very large malarial protein (Mr approximately 300,000) that is exported from the parasite and deposited on the cytoplasmic face of the erythrocyte membrane. This protein is denoted P. falciparum erythrocyte membrane protein 2 (Pf EMP 2). The mAbs did not react with the surface of intact infected erythrocytes, nor was Pf EMP 2 accessible to exogenous proteases or lactoperoxidase-catalyzed radioiodination of intact cells. The mAbs also had no effect on in vitro cytoadherence of infected cells to the C32 amelanotic melanoma cell line. These properties distinguish Pf EMP 2 from Pf EMP 1, the cell surface malarial protein of similar size that is associated with the cytoadherent property of P. falciparum-infected erythrocytes. The mAbs did not react with Pf EMP 1. In one strain of parasite there was a significant difference in relative mobility of the 125I-surface-labeled Pf EMP 1 and the biosynthetically labeled Pf EMP 2, further distinguishing these proteins. By cryo-thin-section immunoelectron microscopy we identified organelles involved in the transit of Pf EMP through the erythrocyte cytoplasm to the internal face of the erythrocyte membrane where the protein is associated with electron- dense material under knobs. These results show that the intraerythrocytic malaria parasite has evolved a novel system for transporting malarial proteins beyond its own plasma membrane...

Parasitoids use chemical footprints to track down caterpillars

Wölfling, Mirko; Rostás, Michael
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
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Parasitoid wasps in search for plant-feeding hosts display typical patterns of behavior. The braconid Cotesia marginiventris, which parasitizes young caterpillars, is guided by herbivore-induced plant volatiles to an infested plant. On the plant, the female wasp searches for further chemical residues (kairomones) originating directly from the host. We showed that caterpillars leave minute amounts of treacherous chemical footprints while walking over a plant surface. Female wasps are able to detect these residues for up to two days after their hosts have left the site. Analyses of the caterpillar footprints revealed that these consisted of linear and monomethyl-branched alkanes as well as few minor unidentified compounds. A reconstructed blend of the major footprint compounds, consisting of linear C21–C32 alkanes, induced characteristic antennation behavior. However, the artificial blend was less attractive than the original one suggesting a role for additional minor compounds in recognizing former caterpillar presence. Previous investigations using wax mutants of barley showed that the physico-chemical traits of the epicuticular leaf wax can modulate the parasitoids' response to host footprints. We hypothesize that long-chain hydrocarbons of insect and plant cuticular origin are important mediators of insect-plant interactions and believe that their role in modulating trophic cascades still awaits full appreciation.

The OH 1612 MHz maser pump rates of stellar, interstellar and post-AGB OH masers

He, J. H.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/02/2005 Português
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(Pseudo) radiative pumprate of OH 1612 MHz masers is defined for a sample of 44 OH/IR sources (infrared sources with OH 1612 MHz maser), irrespective of the real maser pumping mechanisms. The correlation between the (pseudo) maser pumprates and the evolutionary status of the maser sources reveals that the radiative pumprates of stellar OH masers are nearly fixed, which agrees with the theoretical prediction for radiatively pumped OH maser. The (pseudo) radiative pumprates of interstellar OH masers are not only very small but also varying broadly over two orders of magnitude, which is argued to be the manifestation of varying number of quiet absorbing OH cloudlets and/or various OH maser pumping mechanisms and/or competitive gain between mainline and 1612 MHz OH masers and/or anisotropy of the maser emission. The radiative pumprates of post-AGB OH masers very possibly decrease with increasing IRAS C32 color indices and distribute in an interim region between the stellar and interstellar OH masers in the pumprate-color diagram.; Comment: 17 pages, 4 figures, 4 tables

Reexamining closed-form formulae for inclusive breakup: Application to deuteron and $^6$Li induced reactions

Lei, Jin; Moro, Antonio M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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The problem of the calculation of inclusive breakup cross sections in nuclear reactions is reexamined. For that purpose, the post-form theory proposed by Ichimura, Austern and Vincent [Phys. Rev. C32, 431 (1985) is revisited, and an alternative derivation of the non-elastic breakup part of the inclusive breakup is presented, making use of the coupled-channels optical theorem. Using the DWBA version of this model, several applications to deuteron and $^6$Li reactions are presented and compared with available data. The validity of the zero-range approximation of the DWBA formula is also investigated by comparing zero-range with full finite-range calculations.; Comment: 15 pages, 8 figures, updated text and figures; published in Phys. Rev. C

Thermodynamic Properties and Pressure Effect on the Superconductivity in CaAlSi and SrAlSi

Lorenz, B.; Cmaidalka, J.; Meng, R. L.; Chu, C. W.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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Superconductivity in the C32 compounds CaAlSi and SrAlSi is investigated by heat capacity (Cp) measurements as well as high-pressure ac-susceptibility experiments. The heat capacity in the superconducting state is well explained by the BCS theory in the weak-coupling limit. The jump of Cp at the superconducting transition (compared to the normal state electronic heat capacity) is 1.62 and 1.21 for CaAlSi and SrAlSi, respectively, and agrees well with the BCS value of 1.43. The magnitudes of the superconducting gaps are estimated as 2.7 meV (CaAlSi) and 1.4 meV (SrAlSi). The pressure effect on the superconducting transition temperature, dlnTc/dp, is positive in CaAlSi (+0.026 GPa-1) but negative in SrAlSi (-0.024 GPa-1). The opposite sign of the pressure coefficients of Tc indicates distinct differences in the electronic structure and the density of states at the Fermi energy of the two compounds in agreement with recent band structure calculations.; Comment: Revised manuscript, Fig. 1 replaced, Phys. Rev. B in press

Numerical assessment of post-prior equivalence for inclusive breakup reactions

Lei, Jin; Moro, Antonio M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/11/2015 Português
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We address the problem of the post-prior equivalence in inclusive breakup reactions induced by weakly-bound nuclei. The problem is studied within the DWBA model of Ichimura, Austern, Vincent [Phys. Rev. C32, 431 (1985)]. The post and prior formulas obtained in this model are briefly recalled, and applied to several breakup reactions induced by deuterons and $^6$Li projectiles, to test their actual numerical equivalence. The different contributions of the prior-form formula are also discussed. A critical comparison with the prior-form distorted-wave Born approximation (DWBA) model of Udagawa and Tamura [Phys. Rev. C24, 1348 (1981)] is also provided.; Comment: 6 pages, 2 figures, submitted to PRC

Procedimiento para la preparación de un aceite semejante al de jojoba utilizando zeolitas ultraestables como catalizador

Aracil Mira, José; Corma, Avelino; Martínez González, Mercedes
Fonte: Conselho Superior de Investigações Científicas Publicador: Conselho Superior de Investigações Científicas
Tipo: Patente Formato: 90887 bytes; application/pdf
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Referencia OEPM: P9100429.-- Fecha de solicitud: 19/02/1991.-- Titulares: Universidad Politécnica de Valencia (UPV).; Procedimiento para la preparación de un producto análogo al aceite de jojoba por esterilización de ácido oleico con alcoholes oleicos utilizando zeolitas ultraestables como catalizador. La máxima actividad se observa con el producto desaluminizado con vapor y SiCl4. Mientras que las zeolitas ultraestables no catalizan la formación de ésteres con > C36 éstas son muy activas y selectivas para formar ésteres con C32-C36. Se describen las condiciones que ha de reunir el catalizador.; Peer reviewed

New Transmembrane Polyene Bolaamphiphiles as Fluorescent Probes in Lipid Bilayers

Quesada, Ernesto; Acuña, A. Ulises; Amat-Guerri, Francisco
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artículo Formato: 6080 bytes; image/gif
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The former view of the cell lipid membrane as a somewhat random and disordered distribution of lipids and proteins has given way to one characterized by a complex lateral organization, with nm-sized domains in which specific lipids and proteins are assembled to carry out a particular process.[1] The study of the morphology, composition, regulation, and persistence time of these structures is an experimental challenge that has been taken up by fluorescence probe methods. In the case of lipid-lipid and lipid-protein interactions, the dependence of the resonant transfer of electronic excitation on the proximity of donor and acceptor probe molecules can provide very useful information in the 10-nm range.[2] We have previously developed a series of fluorescent fatty acids that contain five conjugated double bonds at the end of a flexible linear chain.[3] These probes accurately report the changes in order and dynamics of the lipid environment in artificial and natural membranes. Furthermore, the large spectral overlap of the polyene absorption with the tryptophan fluorescence from membrane proteins and peptides is very convenient for energy-transfer experiments. However, the mobility of the energy-accepting polyene group in fluid bilayers may introduce some uncertainty into the distance evaluation. This would also be the case in other possible applications of the probes...

Models for Converging Economies

Harvey, Andrew C.; Carvalho, Vasco
Fonte: Universidade de Cambridge Publicador: Universidade de Cambridge
Tipo: Trabalho em Andamento Formato: 530269 bytes; application/pdf; application/pdf
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The aim of this article is the development of models for converging economies. After discussing models of balanced growth, univariate models of the gap between per capital income in two economies are examined. The preferred models combine unobserved components with an error correction mechanism and allow a decomposition into trend, cycle and convergence components. A new type of second-order error correction mechanism is shown to be particularly useful in this respect. The levels of per capita income in two economies may be modelled jointly by bivariate convergence models. These models generalise balanced growth models and can be based on autoregressive or unobserved components formulations. Both approaches provide coherent forecasts but the unobserved components models also yield a description of trends, cycles and convergence components. The methods are applied to data on the US and Japan. The generalisation to multivariate series is then set out.

Growth, Cycles and Convergence in US Regional Time Series

Carvalho, Vasco; Harvey, Andrew C.
Fonte: Universidade de Cambridge Publicador: Universidade de Cambridge
Tipo: Trabalho em Andamento Formato: 1053145 bytes; application/pdf; application/pdf
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Growth, Cycles and Convergence in US Regional Time Series

Cyclical Components in Economic Time Series: a Bayesian Approach

Harvey, Andrew C.; Trimbur, Thomas; van Dijk, Herman
Fonte: Universidade de Cambridge Publicador: Universidade de Cambridge
Tipo: Trabalho em Andamento Formato: 1067180 bytes; application/pdf; application/pdf
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Cyclical components in economic time series are analysed in a Bayesian framework, thereby allowing prior notions about periodicity to be used. The method is based on a general class of unobserved component models that allow relatively smooth cycles to be extracted. Posterior densities of parameters and smoothed cycles are obtained using Markov chain Monte Carlo methods. An application to estimating business cycles in macroeconomic series illustrates the viability of the procedure for both univariate and bivariate models.