7,096 research outputs found

    Exchange Rate Determination with Systematic and Unsystematic Policy Regime Changes: Evidence From the Yen/Dollar Rate

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    This paper presents results of estimating an exchange rate equation in light of theoretical considerations regarding changes in sterilization and intervention policy and tax policy which imply that the coefficients in the equation will not behave as fixed parameters in a given sample period,as standard econometric practice assumes. We compare the results of ordinary least squares and a random coefficients model of the Japanese Yen-- U.S. dollar exchange rate during the floating period of July 1973 through June 1982.When systematic end of year policy changes affecting Japanese reserves are explicitly modeled, both OLS and the random coefficients model show increased explanatory power. The random coefficients model appears to be superior to OLS however; by allowing the coefficients to vary over time as required by the economic theory discussed above, estimates of the mean response coefficients for the floating period all have the hypothesized sign, and explanatory power is sharply increased.

    Future monitoring of charged particle energy deposition into the upper atmosphere and comments on possible relationships between atmospheric phenomena and solar and/or geomagnetic activity

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    Monitoring of earth's atmosphere was conducted for several years utilizing the ITOS series of low-altitude, polar-orbiting weather satellites. A space environment monitoring package was included in these satellites to perform measurements of a portion of earth's charged particle environment. The charged particle observations proposed for the low-altitude weather satellite TIROS N, are described which will provide the capability of routine monitoring of the instantaneous total energy deposition into the upper atmosphere by the precipitation of charged particles from higher altitudes. Such observations may be of use in future studies of the relationships between geomagnetic activity and atmospheric weather pattern developments. Estimates are given to assess the potential importance of this type of energy deposition. Discussion and examples are presented illustrating the importance of distinguishing between solar and geomagnetic activity as possible causative sources. Such differentiation is necessary because of the widely different spatial and time scales involved in the atmospheric energy input resulting from these various sources of activity

    Adjustment of the Elderly in Retirement Homes in Eastern South Dakota

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    In South Dakota, particularly, growing numbers of older citizens give cause for increasing concern with their problems. While the total population of South Dakota declined by 5.8% between 1930 and 1950, during the same period the number of persons 65 years old and older increased by 49.8%.3 By 1958, 10.1% of the state\u27s total population was 65 years old and older, compared with the national figure of 8.8%. A consideration of the preceding discussion makes understandable the increasing interest in life in the later years. This increased interest has stimulated research, concerned not only with problems like medical care, housing, and finances, but concerned also with more subtle problems involving the maintenance of the older person as an integrated, well-functioning personality

    Pulsed beams as field probes for precision measurement

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    We describe a technique for mapping the spatial variation of static electric, static magnetic, and rf magnetic fields using a pulsed atomic or molecular beam. The method is demonstrated using a beam designed to measure the electric dipole moment of the electron. We present maps of the interaction region, showing sensitivity to (i) electric field variation of 1.5 V/cm at 3.3 kV/cm with a spatial resolution of 15 mm; (ii) magnetic field variation of 5 nT with 25 mm resolution; (iii) radio-frequency magnetic field amplitude with 15 mm resolution. This new diagnostic technique is very powerful in the context of high-precision atomic and molecular physics experiments, where pulsed beams have not hitherto found widespread application.Comment: 6 pages, 12 figures. Figures heavily compressed to comply with arxiv's antediluvian file-size polic

    Improved alkaline extraction method for biogenic silica determination in volcanic soils

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    Here we present the first results obtained with an innovative technique aiming at measuring biogenic and lithogenic amorphous silica contents in soils developed on basaltic parent material. Biogenic silica (BSi) has become important to many research domains like soil science, biogeochemistry, aquatic sciences, palaeoecology, and agricultural sciences. In most soils, BSi is a small but highly reactive Si pool in comparison to lithogenic Si sources. This high reactivity makes it a key component of the soil-plant Si cycle. In the last decade, the continental cycle of Si has been increasingly studied, because of (1) the importance of Si as a nutrient for plants and diatoms (studies include e.g., impact of land-use change, export through harvest, influence on crops resistance to various kinds of stress) and (2) the major role of Si during chemical weathering. Constraining Si reservoirs in soils is, however, not an easy task due to the ubiquity of Si. Many methods have been developed to quantify BSi content in soils (mostly alkaline extraction techniques) and other Si pools in soils (e.g., mobile Si, adsorbed Si, … with the sequential Si extraction by Georgiadis et al. 2013 [1]). BSi extraction methods that are based only on solubility are, however, difficult to apply to environments where large amounts of lithogenic amorphous or poorly crystalline aluminosilicates are present, like e.g. in volcanic soils, as their solubility is close to that of BSi. In order to study the soil/plant Si cycle in such soils, leaching methods, quasi-continuously analysing both the dissolution kinetics and the chemistry of the dissolving phases, provide better control of the dissolving Si sources. Several authors successfully used methods similar to the one applied here on various materials. This is however the first study that applies such method with quasi-continuous monitoring of released elements on the challenging material that is volcanic soils

    Unraveling the molecular basis of subunit specificity in P pilus assembly by mass spectrometry

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    P pili are multisubunit fibers essential for the attachment of uropathogenic Escherichia coli to the kidney. These fibers are formed by the noncovalent assembly of six different homologous subunit types in an array that is strictly defined in terms of both the number and order of each subunit type. Assembly occurs through a mechanism termed “donor-strand exchange (DSE)” in which an N-terminal extension (Nte) of one subunit donates a β-strand to an adjacent subunit, completing its Ig fold. Despite structural determination of the different subunits, the mechanism determining specificity of subunit ordering in pilus assembly remained unclear. Here, we have used noncovalent mass spectrometry to monitor DSE between all 30 possible pairs of P pilus subunits and their Ntes. We demonstrate a striking correlation between the natural order of subunits in pili and their ability to undergo DSE in vitro. The results reveal insights into the molecular mechanism by which subunit ordering during the assembly of this complex is achieved

    Cavity QED with optically transported atoms

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    Ultracold 87^{87}Rb atoms are delivered into a high-finesse optical micro-cavity using a translating optical lattice trap and detected via the cavity field. The atoms are loaded into an optical lattice from a magneto-optic trap (MOT) and transported 1.5 cm into the cavity. Our cavity satisfies the strong-coupling requirements for a single intracavity atom, thus permitting real-time observation of single atoms transported into the cavity. This transport scheme enables us to vary the number of intracavity atoms from 1 to >>100 corresponding to a maximum atomic cooperativity parameter of 5400, the highest value ever achieved in an atom--cavity system. When many atoms are loaded into the cavity, optical bistability is directly measured in real-time cavity transmission.Comment: 4 figures, 4 page

    Cavity QED in a molecular ion trap

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    We propose an approach for studying quantum information and performing high resolution spectroscopy of rotational states of trapped molecular ions using an on-chip superconducting microwave resonator. Molecular ions have several advantages over neutral molecules. Ions can be loaded into deep (1 eV) RF traps and are trapped independent of the electric dipole moment of their rotational transition. Their charge protects them from motional dephasing and prevents collisional loss, allowing 1 s coherence times when used as a quantum memory, with detection of single molecules possible in <10 ms. An analysis of the detection efficiency and coherence properties of the molecules is presented.Comment: 9 pages, 1 figur

    Measurement of the electron electric dipole moment using YbF molecules

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    The most sensitive measurements of the electron electric dipole moment d_e have previously been made using heavy atoms. Heavy polar molecules offer a greater sensitivity to d_e because the interaction energy to be measured is typically 10^3 times larger than in a heavy atom. We report the first measurement of this kind, for which we have used the molecule YbF. Together, the large interaction energy and the strong tensor polarizability of the molecule make our experiment essentially free of the systematic errors that currently limit d_e measurements in atoms. Our first result d_e = (- 0.2 \pm 3.2) x 10^-26 e.cm is less sensitive than the best atom measurement, but is limited only by counting statistics and demonstrates the power of the method.Comment: 4 pages, 4 figures. v2. Minor corrections and clarifications made in response to referee comment
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