845 research outputs found

    The Impact of Monetary Union on Trade Prices

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    Two seemingly unconnected empirical results suggest an intriguing mechanism. First, economic integration helps harmonize prices internationally, with trade being the primary channel (Rogoff 1996, Goldberg and Knetter 1997). Second, monetary union may greatly increase the amount of trade among members (Rose 2001). Putting these together, we see that formation of a monetary union may induce changes that help harmonise inflation rates. The effect might be large if the elimination of exchange rate volatility simultaneously leads to a large increase in intra-union trade and a big increase in the speed at which price shocks are transmitted across members' goods markets. The problem is that standard estimates of price transmission speed suggest that trade's price-homogenising effect operates too slowly to matter much. Some new empirical evidence, however, suggests that a reduction in exchange rate variability reduces the variability of international price differences. Moreover, the effect seems to be highly nonlinear, and monetary union seems to have an effect even controlling for exchange rate volatility. This paper is a first attempt to piece together part of this mechanism, namely the impact of monetary union (and exchange rate volatility more generally) on the international transmission of price shocks via the imported/exported inflation channel. In doing this we generate specific testable hypotheses and confront these with a number of data sets on European trade prices.price arbitrage, exchange rate volatility, monetary union, market segmentation, non-linearities, no-arbitrage bands, harmonisation of price movements

    The impact of monetary union on trade prices

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    Two seemingly unconnected empirical results suggest an intriguing mechanism. First, economic integration helps harmonize prices internationally, with trade being the primary channel (Rogoff 1996, Goldberg and Knetter 1997). Second, monetary union may greatly increase the amount of trade among members (Rose 2001). Putting these together, we see that formation of a monetary union may induce changes that help harmonise inflation rates. The effect might be large if the elimination of exchange rate volatility simultaneously leads to a large increase in intra-union trade and a big increase in the speed at which price shocks are transmitted across members' goods markets. This paper investigates part of this mechanism and finds that monetary union may indeed result in faster cross-border transmission of price movements via the import and export price channel which, in turn, would tend to homogenise price movements across the member countries of a monetary union. JEL Classification: D40, F15, F31Exchange rate volatility, harmonisation of price movements, market segmentation, monetary union, no-arbitrage bands

    Internal evaluation of a physically-based distributed model using data from a Mediterranean mountain catchment

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    An evaluation of the performance of a physically-based distributed model of a small Mediterranean mountain catchment is presented. This was carried out using hydrological response data, including measurements of runoff, soil moisture, phreatic surface level and actual evapotranspiration. <i>A-priori</i> model parameterisation was based as far as possible on property data measured in the catchment. Limited model calibration was required to identify an appropriate value for terms controlling water loss to a deeper regional aquifer. The model provided good results for an initial calibration period, when judged in terms of catchment discharge. However, model performance for runoff declined substantially when evaluated against a consecutive, rather drier, period of data. Evaluation against other catchment responses allowed identification of the problems responsible for the observed lack of model robustness in flow simulation. In particular, it was shown that an incorrect parameterisation of the soil water model was preventing adequate representation of drainage from soils during hydrograph recessions. This excess moisture was then being removed via an overestimation of evapotranspiration. It also appeared that the model underestimated canopy interception. The results presented here suggest that model evaluation against catchment scale variables summarising its water balance can be of great use in identifying problems with model parameterisation, even for distributed models. Evaluation using spatially distributed data yielded less useful information on model performance, owing to the relative sparseness of data points, and problems of mismatch of scale between the measurement and the model grid.</p> <p style='line-height: 20px;'><b>Keywords: </b>physically-based distributed model, SHETRAN, parameterisation, Mediterranean mountain catchment, internal evaluation, multi-respons

    IL-10 permits transient activation of dendritic cells to tolerize T cells and protect from central nervous system autoimmune disease

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    Dendritic cells (DCs) are key players in the development of immunity. They can direct both the size and the quality of an immune response and thus are attractive tools to mediate immunotherapy. DC function has been thought to reflect the cells' maturation, with immunosuppressive agents such as IL-10 understood to retain DCs in an immature and tolerogenic state. Here we report that DC activated in the presence of IL-10 do show functional and phenotypic maturation. Their activation is transient and occurs earlier and more briefly than in cells matured with LPS alone. Despite initially equivalent up-regulation of surface MHC and co-stimulation, the IL-10-treated DCs expressed little IL-12 and failed to stimulate T cell proliferation both in vitro and in vivo. Interaction with IL-10-treated DCs rendered antigen-specific T cells unresponsive to subsequent challenge and their injection reduced the severity of experimental autoimmune disease. Our data suggest that IL-10 acts not by inhibiting maturation but instead by controlling the kinetics and the quality of DC activation. This alternative pathway of DC differentiation offers significant therapeutic promise

    Whatever happened to "always cite the source?" a study of source citing and other issues related to telephone reference

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    Reference & User Services Quarterly, 47(1): pp. 44-54.This article presents a study of source citing in telephone reference service at the twenty-five largest public library systems in the United States and Canada. The results showed that in eighty-six out of the 125 total reference transactions analyzed (68.8 percent of the cases), respondents gave no sources for their answers. The article also discusses a number of additional issues uncovered during the study that are not related to source citing but that have important itnplications for reference services. The authors conclude that best reference practices are not being followed in many instances of public library telephone reference, and they close with a number of simple suggestions for improving telephone, face-to-face, and digital reference services

    Pliocene-Pleistocene marine cyclothems, Wanganui Basin, New Zealand: a lithostratigraphic framework

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    The Rangitikei River valley between Mangaweka and Vinegar Hill and the surrounding Ohingaiti region in eastern Wanganui Basin contains a late Pliocene to early Pleistocene (c. 2.6-1.7 Ma), c. 1100 m thick, southward-dipping (4-9deg.), marine cyclothemic succession. Twenty sedimentary cycles occur within the succession, each of which contains coarse-grained (siliciclastic sandstone and coquina) and fine-grained (siliciclastic siltstone) units. Nineteen of the cycles are assigned to the Rangitikei Group (new). Six new formations are defined within the Rangitikei Group, and their distribution in the Ohingaiti region is represented in a new geologic map. The new formations are named: Mangarere, Tikapu, Makohine, Orangipongo, Mangaonoho, and Vinegar Hill. Each formation comprises one or more cyclothems and includes a previously described and named distinctive basal horizon. Discrete sandstones, siltstones, and coquinas within formations are assigned member status and correspond to systems tracts in sequence stratigraphic nomenclature. The members provide the link between the new formational lithostratigraphy and the sequence stratigraphy of the Rangitikei Group. Base of cycle coquina members accumulated during episodes of sediment starvation associated with stratigraphic condensation on an open marine shelf during sea-level transgressions. Siltstone members accumulated in mid-shelf environments (50-100 m water depth) during sea-level highstands, whereas the overlying sandstone members are ascribed to inner shelf and shoreface environments (0-50 m water depth) and accumulated during falling eustatic sea-level conditions. Repetitive changes in water depth of 50-100 m magnitude are consistent with a glacio-eustatic origin for the cyclothems, which correspond to an interval of Earth history when successive glaciations in the Northern Hemisphere are known to have occurred. Moreover, the chronology of the Rangitikei River section indicates that Rangitikei Group cyclothems accumulated during short duration, 41 ka cycles in continental ice volume attributed to the dominance of the Milankovitch obliquity orbital parameter. The Ohingaiti region has simple postdepositional structure. The late Pliocene formations dip generally to the SSW between 4deg. and 9deg.. Discernible discordances of c. 1deg. between successively younger formations are attributed to synsedimentary tilting of the shelf concomitant with migration of the tectonic hingeline southward into the basin. The outcrop distribution of the Rangitikei Group is strongly influenced by this regional tilt and also by three major northeast-southwest oriented, high-angle reverse faults (Rauoterangi, Pakihikura, and Rangitikei Faults)

    Negative Selection during the Peripheral Immune Response to Antigen

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    Thymic selection depends on positive and negative selective mechanisms based on the avidity of T cell interaction with antigen–major histocompatibility complex complexes. However, peripheral mechanisms for the recruitment and clonal expansion of the responding T cell repertoire remain obscure. Here we provide evidence for an avidity-based model of peripheral T cell clonal expansion in response to antigenic challenge. We have used the encephalitogenic, H-2 Au-restricted, acetylated NH2-terminal nonameric peptide (Ac1-9) epitope from myelin basic protein as our model antigen. Peptide analogues were generated that varied in antigenic strength (as assessed by in vitro assay) based on differences in their binding affinity for Au. In vivo, these analogues elicited distinct repertoires of T cells that displayed marked differences in antigen sensitivity. Immunization with the weakest (wild-type) antigen expanded the high affinity T cells required to induce encephalomyelitis. In contrast, immunization with strongly antigenic analogues led to the elimination of T cells bearing high affinity T cell receptors by apoptosis, thereby preventing disease development. Moreover, the T cell repertoire was consistently tuned to respond to the immunizing antigen with the same activation threshold. This tuning mechanism provides a peripheral control against the expansion of autoreactive T cells and has implications for immunotherapy and vaccine design

    Netrin-3 and Netrin-4-Like Proteins are Secreted from \u3cem\u3eTetrahymena thermophila\u3c/em\u3e

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    Netrins are signaling proteins, acting as chemorepellants or chemoattractants, and their role is especially important in early growth in organisms. In studies involving Tetrahymena thermophila, netrin proteins often act as chemorepellants, so research centered around verifying if this was also true for Netrin-4 protein. Since Netrin-1 and Netrin-3 have been shown to influence neurological and developmental growth in organisms, the implications for discovering the cellular effects of Netrin-4 are significant for human health and research. Through behavioral assays, we were able to confirm that Netrin4 does act as a chemorepellant. In addition, our ELISA and Western blots also helped substantiate the idea that Tetrahymena produce Netrin-4 for physiological functions, as they possess receptors for these proteins. The exact purposes of Netrin-4 for this organism is unknown up to this point, so further testing is needed to determine the cellular mechanisms with which Netrin-4 is involved
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