360 research outputs found

    Monetary Policy Nominalization in Chile: an Evaluation

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    In August of 2001, the Central Bank of Chile modified its main monetary policy instrument, the inflation-indexed monetary policy interest rate MPR it had used so far, to a nominal or peso-denominated rate. A number of consequences, both in the conduct of monetary policy and in the country’s financial markets, can be associated to this new way of taking monetary policy actions. This article evaluates such effects, providing theoretical support and evidence to several hypotheses, some of them found in the existing literature. The main contribution of this so-called “nominalization”—that has not been discussed earlier—is that it extends the scope of operation of monetary policy, something that becomes important when both the interest rate and the inflation rate are low, as is the case today.

    Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA

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    Inclusive photoproduction of D*+- mesons has been measured for photon-proton centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of 37 pb^-1. Total and differential cross sections as functions of the D* transverse momentum and pseudorapidity are presented in restricted kinematical regions and the data are compared with next-to-leading order (NLO) perturbative QCD calculations using the "massive charm" and "massless charm" schemes. The measured cross sections are generally above the NLO calculations, in particular in the forward (proton) direction. The large data sample also allows the study of dijet production associated with charm. A significant resolved as well as a direct photon component contribute to the cross section. Leading order QCD Monte Carlo calculations indicate that the resolved contribution arises from a significant charm component in the photon. A massive charm NLO parton level calculation yields lower cross sections compared to the measured results in a kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure

    Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA

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    Correlations between charged particles in deep inelastic ep scattering have been studied in the Breit frame with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in terms of the angular separation between current-region particles within a cone centred around the virtual photon axis. Long-range correlations between the current and target regions have also been measured. The data support predictions for the scaling behaviour of the angular correlations at high Q2 and for anti-correlations between the current and target regions over a large range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations and Monte Carlo models correctly describe the trends of the data at high Q2, but show quantitative discrepancies. The data show differences between the correlations in deep inelastic scattering and e+e- annihilation.Comment: 26 pages including 10 figures (submitted to Eur. J. Phys. C

    Hermafroditismo verdadeiro na espécie suína.

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    Resumo: Os hermafroditas verdadeiros sĂŁo animais com intersexualidade, nos quais as gĂŽnadas masculinas e femininas se desenvolvem simultaneamente no mesmo indivĂ­duo. Este trabalho relata um caso de hermafrodita na espĂ©cie suĂ­na apĂłs descarte de uma fĂȘmea por diagnĂłstico de anestro. Tratava-se de uma fĂȘmea com 222 dias de idade e 150 kg a qual havia sido selecionada para reprodução e permanecia em anestro. O indivĂ­duo foi descartado e enviado para o abate em frigorĂ­fico sob inspeção federal. ApĂłs o abate foi observado no sistema genital aspectos anatĂŽmicos sugestivos de hermafroditismo. O sistema genital foi coletado, inspecionado macroscopicamente e conservado em formol a 10% para avaliação microscĂłpica. Durante a anĂĄlise macroscĂłpica foi verificada a presença de vulva e vagina, contendo um pĂȘnis rudimentar. O Ăștero, a cĂ©rvix, os cornos uterinos e oviduto estavam presentes e com ausĂȘncia de anormalidade. Havia um ovĂĄrio esquerdo com aspectos morfolĂłgicos de ciclicidade e folĂ­culos contendo oĂłcitos de alta qualidade. À direita, entretanto, foi constatada a presença de um testĂ­culo, epidĂ­dimo e plexo pampiniforme. A avaliação histopatolĂłgica comprovou os achados macroscĂłpicos, demonstrando um ovĂĄrio contendo folĂ­culos, corpos lĂșteos e cistos foliculares; plexo pampiniforme; testĂ­culo e epidĂ­dimo com aspecto histolĂłgico normal, porĂ©m, com ausĂȘncia de cĂ©lulas espermatogĂȘnicas. Assim, com base nos achados macro e microscĂłpicos descritos nesse relato de caso, o indivĂ­duo foi considerado como hermafrodita verdadeiro. Abstract: True hermaphrodites are intersexual animals, in which both male and female gonads develop simultaneously in the same individual. This paper reports a case of a true hermaphrodite in the swine species after its culling for anestrus. The specimen was a female of 222 days of age and 150 kg of body weight, that was selected for reproduction and was permanently in anestrus. This individual was culled and sent to an abattoir under federal inspection. After slaughtering, it was observed in the reproductive tract anatomical aspects that suggested hermaphroditism. The reproductive tract was collected, evaluated macroscopically, and preserved in formaldehyde at 10 % to be evaluated by light microscopy. During the macroscopic analysis, the presence of a vulva and a vagina with a rudimentary penis was detected. The uterus, the cervix, uterine horns, and the oviduct were present and abnormalities were not detected. The left ovary exhibited morphological signs of cyclicity and contained follicles with high quality oocytes. On the right side, however, it was observed a testicle, epididymis, and a pampiniform plexus. The histopathological assessment corroborated the macroscopic findings, which demonstrated that the ovary had follicles, corpus luteum, and follicular cysts, and pampiniform plexus, testicle and epididymis were histologically normal, though with the absence of spermatogenic cells. Thus, based on the macro and microscopic findings described herein, the individual was considered a true hermaphrodite

    α-Thalassemia Impairs the Cytoadherence of Plasmodium falciparum-Infected Erythrocytes

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    α-Thalassemia results from decreased production of α-globin chains that make up part of hemoglobin tetramers (Hb; α(2)ÎČ(2)) and affects up to 50% of individuals in some regions of sub-Saharan Africa. Heterozygous (-α/αα) and homozygous (-α/-α) genotypes are associated with reduced risk of severe Plasmodium falciparum malaria, but the mechanism of this protection remains obscure. We hypothesized that α-thalassemia impairs the adherence of parasitized red blood cells (RBCs) to microvascular endothelial cells (MVECs) and monocytes--two interactions that are centrally involved in the pathogenesis of severe disease.We obtained P. falciparum isolates directly from Malian children with malaria and used them to infect αα/αα (normal), -α/αα and -α/-α RBCs. We also used laboratory-adapted P. falciparum clones to infect -/-α RBCs obtained from patients with HbH disease. Following a single cycle of parasite invasion and maturation to the trophozoite stage, we tested the ability of parasitized RBCs to bind MVECs and monocytes. Compared to parasitized αα/αα RBCs, we found that parasitized -α/αα, -α/-α and -/-α RBCs showed, respectively, 22%, 43% and 63% reductions in binding to MVECs and 13%, 33% and 63% reductions in binding to monocytes. α-Thalassemia was associated with abnormal display of P. falciparum erythrocyte membrane protein 1 (PfEMP1), the parasite's main cytoadherence ligand and virulence factor, on the surface of parasitized RBCs.Parasitized α-thalassemic RBCs show PfEMP1 display abnormalities that are reminiscent of those on the surface of parasitized sickle HbS and HbC RBCs. Our data suggest a model of malaria protection in which α-thalassemia ameliorates the pro-inflammatory effects of cytoadherence. Our findings also raise the possibility that other unstable hemoglobins such as HbE and unpaired α-globin chains (in the case of ÎČ-thalassemia) protect against life-threatening malaria by a similar mechanism
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