1,666 research outputs found

    Inflation and Unemployment In EMU and the United States. ACES Working Papers No. 10, 2008

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    The original purpose of this paper was to see why the Phillips Curve numbers seem to be so much worse for the EMU countries than the United States since EMU was began operation in 1990. The problem is that there is no evidence of a Phillips curve relationship in EMU or in the United States during this seventeen year period. As can be seen in Figures 1 and 2, it just is not there. In about half the years unemployment and inflation moved in the opposite direction, as Phillips would predict, but in other half of the years they moved in the same direction. This may be a matter of time lags, with unemployment lagging inflation, but it seems clear that the Phillips curve is a poor tool for explaining these year to year outcomes in Europe or the United States

    Observational manifestations of solar magneto-convection -- center-to-limb variation

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    We present the first center-to-limb G-band images synthesized from high resolution simulations of solar magneto-convection. Towards the limb the simulations show "hilly" granulation with dark bands on the far side, bright granulation walls and striated faculae, similar to observations. At disk center G-band bright points are flanked by dark lanes. The increased brightness in magnetic elements is due to their lower density compared with the surrounding intergranular medium. One thus sees deeper layers where the temperature is higher. At a given geometric height, the magnetic elements are cooler than the surrounding medium. In the G-band, the contrast is further increased by the destruction of CH in the low density magnetic elements. The optical depth unity surface is very corrugated. Bright granules have their continuum optical depth unity 80 km above the mean surface, the magnetic elements 200-300 km below. The horizontal temperature gradient is especially large next to flux concentrations. When viewed at an angle, the deep magnetic elements optical surface is hidden by the granules and the bright points are no longer visible, except where the "magnetic valleys" are aligned with the line of sight. Towards the limb, the low density in the strong magnetic elements causes unit line-of-sight optical depth to occur deeper in the granule walls behind than for rays not going through magnetic elements and variations in the field strength produce a striated appearance in the bright granule walls.Comment: To appear in ApJL. 6 pages 4 figure

    Functional Analysis of Subunit e of the F\u3csub\u3e1\u3c/sub\u3eF\u3csub\u3eo\u3c/sub\u3e-ATP Synthase of the Yeast \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e: Importance of the N-Terminal Membrane Anchor Region

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    Mitochondrial F1Fo-ATP synthase complexes do not exist as physically independent entities but rather form dimeric and possibly oligomeric complexes in the inner mitochondrial membrane. Stable dimerization of two F1Fo-monomeric complexes involves the physical association of two membrane-embedded Fo-sectors. Previously, formation of the ATP synthase dimeric-oligomeric network was demonstrated to play a critical role in modulating the morphology of the mitochondrial inner membrane. In Saccharomyces cerevisiae, subunit e (Su e) of the Fo-sector plays a central role in supporting ATP synthase dimerization. The Su e protein is anchored to the inner membrane via a hydrophobic region located at its N-terminal end. The hydrophilic C-terminal region of Su e resides in the intermembrane space and contains a conserved coiled-coil motif. In the present study, we focused on characterizing the importance of these regions for the function of Su e. We created a number of C-terminal-truncated derivatives of the Su e protein and expressed them in the Su e null yeast mutant. Mitochondria were isolated from the resulting transformant strains, and a number of functions of Su e were analyzed. Our results indicate that the N-terminal hydrophobic region plays important roles in the Su e-dependent processes of mitochondrial DNA maintenance, modulation of mitochondrial morphology, and stabilization of the dimer-specific Fo subunits, subunits g and k. Furthermore, we show that the C-terminal coiled-coil region of Su e functions to stabilize the dimeric form of detergent-solubilized ATP synthase complexes. Finally, we propose a model to explain how Su e supports the assembly of the ATP synthase dimers-oligomers in the mitochondrial membrane

    Dual detection high-speed capillary electrophoresis for simultaneous serum protein analysis and immunoassays

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    Serum protein electrophoresis (SPE) separates serum proteins into bands whose shape and amplitude can alert clinicians to a range of disorders. This is followed by more specific immunoassays to quantify important antigens and confirm a diagnosis. Here we develop a high-speed capillary electrophoresis (HSCE) platform capable of simultaneous SPE and immunoassay measurements. A single laser excitation source is focused into the detection zone of the capillary to measure both refractive index (SPE) and fluorescence signals (immunoassays). The refractive index signal measures characteristic SPE profiles for human serum separated in 100 mM boric acid (pH 10), 100 mM arginine (pH 11), and 20 mM CHES (pH 10). For the immunoassay, the fluorescence electropherograms reveal that CHES provides the optimal buffer for measuring the immunocomplex and separating it from the free antigen. Immunoassays in CHES yield a LOD of 23 nM and a LOQ of 70 nM for the detection of fluorescein. The high pH reduces protein adsorption but reduces antibody affinity. Preliminary studies carried out in 50 mM barbital at pH 8 show improved stability of the immunocomplex and better separation for immunoassay quantification. Further optimization will open new capabilities for measuring orthogonal diagnostic signals in seconds with HSCE

    Single molecule detection and underwater fluorescence imaging with cantilevered near-field fiber optic probes

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    This is the published version, also available here: http://dx.doi.org/10.1063/1.121505.Tapping-mode near-field scanning optical microscopy (NSOM) employing a cantilevered fiber optic probe is utilized to image the fluorescence from single molecules and samples in aqueous environments. The single molecule fluorescenceimages demonstrate both the subdiffraction limit spatial resolution and low detection limit capabilities of the cantilevered probe design. Images taken as a function of tip oscillation drive amplitude reveal a degradation in the resolution as the amplitude is increased. With all cantilevered probes studied, however, a minimum plateau region in the resolution is reached as the drive amplitude is decreased, indicating that the tapping mode of operation does not reduce the optical resolution. Images of fluorescently dopedlipid films illustrate the ability of the probe to track small height changes (<1.5 nm) in ambient and aqueous environments, while maintaining high resolution in the fluorescenceimage. When the tip is immersed in water (1.3 mm), the cantilevered NSOM tip resonance, 25–50 kHz, shifts approximately 100–150 Hz, the amplitude dampens less than 40% and the Q factor is reduced from 300–500 to 100–200

    EMU Convergence: Reason for Encouragement. ACES Working Paper (Report) No. 6, 2007

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    The purpose of this paper is to investigate whether convergence is actually occurring within Europe, which groups of countries are converging, and the macroeconomic indicators for which such convergence is apparent. Free trade and a single currency should lead to convergence in rates of inflation, but perhaps not in unemployment rates or in GDP growth. These latter aspects of economic performance are politically important, because the voters become decidedly displeased if unemployment is high and growth slow, as has been the case in France, Germany, and Italy during recent years

    HadISD: a quality-controlled global synoptic report database for selected variables at long-term stations from 1973--2011

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    [Abridged] This paper describes the creation of HadISD: an automatically quality-controlled synoptic resolution dataset of temperature, dewpoint temperature, sea-level pressure, wind speed, wind direction and cloud cover from global weather stations for 1973--2011. The full dataset consists of over 6000 stations, with 3427 long-term stations deemed to have sufficient sampling and quality for climate applications requiring sub-daily resolution. As with other surface datasets, coverage is heavily skewed towards Northern Hemisphere mid-latitudes. The dataset is constructed from a large pre-existing ASCII flatfile data bank that represents over a decade of substantial effort at data retrieval, reformatting and provision. These raw data have had varying levels of quality control applied to them by individual data providers. The work proceeded in several steps: merging stations with multiple reporting identifiers; reformatting to netCDF; quality control; and then filtering to form a final dataset. Particular attention has been paid to maintaining true extreme values where possible within an automated, objective process. Detailed validation has been performed on a subset of global stations and also on UK data using known extreme events to help finalise the QC tests. Further validation was performed on a selection of extreme events world-wide (Hurricane Katrina in 2005, the cold snap in Alaska in 1989 and heat waves in SE Australia in 2009). Although the filtering has removed the poorest station records, no attempt has been made to homogenise the data thus far. Hence non-climatic, time-varying errors may still exist in many of the individual station records and care is needed in inferring long-term trends from these data. A version-control system has been constructed for this dataset to allow for the clear documentation of any updates and corrections in the future.Comment: Published in Climate of the Past, www.clim-past.net/8/1649/2012/. 31 pages, 23 figures, 9 pages. For data see http://www.metoffice.gov.uk/hadobs/hadis

    Counting ants (Hymenoptera: Formicidae): Biodiversity sampling and statistical analysis for myrmecologists

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    Biodiversity sampling is labor intensive and is especially challenging for myrmecologists, because the sampling units (individual workers) do not correspond in a simple way to the natural units of diversity (individual nests). Because it is usually not possible to reach a sampling asymptote for ants, comparisons of species richness among collections have to be carefully standardized for the number of individuals and number of samples examined. Asymptotic estimators allow for extrapolation to an estimated asymptote of species richness, and rarefaction curves permit meaningful comparisons of samples by interpolating data to a standardized number of sampling units. Winkler sacks of leaf litter and specialized traps for arboreal ants often yield distinctive sets of species in tropical and subtropical latitudes. These microhabitats are best treated as distinctive assemblages that can be compared with stratified sampling. Within other habitat types, different baiting and sampling methods yield similar, but not identical sets of species, and many authors have advocated using a diversity of methods to gain the greatest coverage of species. However, many of the distinctive species that are sampled by a particular method are rare, and are just as likely to have been found with other sampling methods. The estimated similarity in composition of ants sampled by different methods in the same habitat is probably greater than has been appreciated. Recent published comparisons of sampling efficiency have shown that hand collecting accumulates species more efficiently than the more commonly used pitfall traps or baits. However, if hand-collected samples are to be analyzed quantitatively, hand sampling must be standardized to a constant plot size that is searched for a fixed amount of time, and all nests encountered must be sampled and counted. For comparative studies of ant assemblages across habitats, hand collecting may be superior to either litter sampling or pitfall traps because it can be used in sites that have no leaf litter or are too environmentally sensitive, too rocky, too steep, or contain too much human and domestic animal traffic for pitfall trapping. Data from hand sampling and grids of pitfall traps lend themselves to slightly different kinds of analyses. Hand sampling probably gives the best estimates of the true frequency of nests of different species in an area, and the data can be used with individual-based rarefaction curves and many standard parametric statistical tests. Data from pitfalltrap grids should usually be treated as sample-based occurrences, and analyzed with sample-based rarefaction and diversity estimators. For the purposes of estimating diversity, myrmecologists should avoid the temptation to analyze the underlying counts of individual workers. Data from replicated grids of pitfall traps can be analyzed with hierarchical occupancy models. These newly developed models provide useful estimates of probabilities of occurrence and probabilities of detection for each species in the assemblage. Biogeographic patterns of ant diversity, such as latitudinal gradients of species richness, are comparable to those seen in other taxa, and the data collected by myrmecologists can contribute in important ways to our general understanding of biodiversity patterns
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