1,560 research outputs found

    Owners\u27 Equivalent Rent and the Consumer Price Index: 30 Years and Counting

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    The objective of the Consumer Price Index (CPI) is to measure the change in expenditures required to maintain a given standard of living. For expenditures on houses, this leads to a measurement objective that focuses on the shelter services provided by a house over a period of time. A house is a capital asset that provides a flow of services over a substantial period of time, not a one-time consumption item. The Bureau of Labor Statistics (BLS) explored two major approaches to determine how to estimate the cost of shelter services for owner-occupied dwellings. The first approach attempts to estimate the flow of shelter services for an owned dwelling from items related to living in it. This approach is called “user cost” and includes items such as real estate taxes, insurance, and an interest estimate based on the market value of the house. The second approach attempts to estimate the flow of services for an owner dwelling based on market rents for rented dwellings. This research led to a method referred to as “rental equivalence.” This method measures the rate of change in the amount an owner would need to pay in order to rent on the open market. It is based on actual market rents collected from a sample of renter-occupied housing units that are identified to be representative of owner-occupied housing. On October 27, 1981, Commissioner Janet Norwood announced that BLS would convert the CPI for All Urban Consumers (CPI-U) to a rental equivalence measure for homeowner costs, effective with data for January 1983. The CPI for Urban Wage Earners and Clerical Workers (CPI-W) would be converted to the new method, effective with the January 1985 data. This announcement was consistent with general BLS practice of giving at least 1-year’s notice before making a major methodological change. The change also meant that the CPI-U for 1983 and 1984—the first years the CPI was to be used in the escalation of personal income tax brackets and exemptions—would use the new methodology. The longer period of notice for the CPI-W was provided, because the CPI-W continued to be the primary index used in cost-of-living adjustments in collective bargaining agreements and in the escalation of government entitlement payments. It was felt that sufficient time needed to be provided for users to adapt to the change. The transition to the new method was smooth, in large part, owing to the open way it was done and the extensive public information effort

    350 ÎŒm dust emission from high-redshift quasars

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    We report detections of six high-redshift (1.8 ≀ z ≀ 6.4), optically luminous, radio-quiet quasars at 350 ÎŒm, using the SHARC II bolometer camera at the Caltech Submillimeter Observatory. Our observations double the number of high-redshift quasars for which 350 ÎŒm photometry is available. By combining the 350 ÎŒm measurements with observations at other submillimeter/millimeter wavelengths, for each source we have determined the temperature of the emitting dust (ranging from 40 to 60 K) and the far-infrared luminosity [(0.6-2.2) × 10^(13) L⊙]. The combined mean spectral energy distribution of all high-redshift quasars with two or more rest-frame far-infrared photometric measurements is best fit with a graybody with temperature of 47 ± 3 K and a dust emissivity power-law spectral index of ÎČ = 1.6 ± 0.1. This warm dust component is a good tracer of the starburst activity of the quasar host galaxy. The ratio of the far-infrared to radio luminosities of infrared-luminous, radio-quiet high-redshift quasars is consistent with that found for local star-forming galaxies

    Extended h-Index Parameterized Data Structures for Computing Dynamic Subgraph Statistics

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    We present techniques for maintaining subgraph frequencies in a dynamic graph, using data structures that are parameterized in terms of h, the h-index of the graph. Our methods extend previous results of Eppstein and Spiro for maintaining statistics for undirected subgraphs of size three to directed subgraphs and to subgraphs of size four. For the directed case, we provide a data structure to maintain counts for all 3-vertex induced subgraphs in O(h) amortized time per update. For the undirected case, we maintain the counts of size-four subgraphs in O(h^2) amortized time per update. These extensions enable a number of new applications in Bioinformatics and Social Networking research

    Invasive alien species in the food chain : advancing risk assessment models to address climate change, economics and uncertainty

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    Economic globalization depends on the movement of people and goods between countries. As these exchanges increase, so does the potential for translocation of harmful pests, weeds, and pathogens capable of impacting our crops, livestock and natural resources (Hulme 2009), with concomitant impacts on global food security (Cook et al. 2011)

    Retrieval Consistency between LST CCI Satellite Data Products over Europe and Africa

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    The assessment of satellite-derived land surface temperature (LST) data is essential to ensure their high quality for climate applications and research. This study intercompared seven LST products (i.e., ATSR_3, MODISA, MODIST, SLSTRA, SLSTRB, SEVIR2 and SEVIR4) of the European Space Agency’s (ESA) LST Climate Change Initiative (LST_cci) project, which are retrieved for polar and geostationary orbit satellites, and three operational LST products: NASA’s MODIS MOD11/MYD11 LST and ESA’s AATSR LST. All data were re-gridded on to a common spatial grid of 0.05° and matched for concurrent overpasses within 5 min. The matched data were analysed over Europe and Africa for monthly and seasonally aggregated median differences and studied for their dependence on land cover class and satellite viewing geometry. For most of the data sets, the results showed an overall agreement within ±2 K for median differences and robust standard deviation (RSD). A seasonal variation of median differences between polar and geostationary orbit sensor data was observed over Europe, which showed higher differences in summer and lower in winter. Over all land cover classes, NASA’s operational MODIS LST products were about 2 K colder than the LST_cci data sets. No seasonal differences were observed for the different land covers, but larger median differences between data sets were seen over bare soil land cover classes. Regarding the viewing geometry, an asymmetric increase of differences with respect to nadir view was observed for day-time data, which is mainly caused by shadow effects. For night-time data, these differences were symmetric and considerably smaller. Overall, despite the differences in the LST retrieval algorithms of the intercompared data sets, a good consistency between the LST_cci data sets was determined

    A combined diffraction (XRD, electron and neutron) and dielectric study of Na3MoO3F3

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    For the dielectric measurements, Na3MoO3F3 ceramics were cut and polished down to a disc with a thickness of 0.5 mm and a diameter of 4.79 mm. Gold electrodes were then sputtered onto both surfaces of the sample. Its polarisation hysteresis loop was characterised by a ferro- and piezo-electric measuring system (TA Analyser 2000, aixACT). The temperature dependence of the dielectric constant and the dissipation factor of Na3MoO3F3 was investigated at 10KHz by a high precision LCR meter (3522, Hioki) between room temperature and 180oC using a scan rate of 5oC/min

    Comprehensive In Situ Validation of Five Satellite Land Surface Temperature Data Sets over Multiple Stations and Years

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    Global land surface temperature (LST) data derived from satellite-based infrared radiance measurements are highly valuable for various applications in climate research. While in situ validation of satellite LST data sets is a challenging task, it is needed to obtain quantitative information on their accuracy. In the standardised approach to multi-sensor validation presented here for the first time, LST data sets obtained with state-of-the-art retrieval algorithms from several sensors (AATSR, GOES, MODIS, and SEVIRI) are matched spatially and temporally with multiple years of in situ data from globally distributed stations representing various land cover types in a consistent manner. Commonality of treatment is essential for the approach: all satellite data sets are projected to the same spatial grid, and transformed into a common harmonized format, thereby allowing comparison with in situ data to be undertaken with the same methodology and data processing. The large data base of standardised satellite LST provided by the European Space Agency’s GlobTemperature project makes previously difficult to perform LST studies and applications more feasible and easier to implement. The satellite data sets are validated over either three or ten years, depending on data availability. Average accuracies over the whole time span are generally within ±2.0 K during night, and within ± 4.0 K during day. Time series analyses over individual stations reveal seasonal cycles. They stem, depending on the station, from surface anisotropy, topography, or heterogeneous land cover. The results demonstrate the maturity of the LST products, but also highlight the need to carefully consider their temporal and spatial properties when using them for scientific purposes

    Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile

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    © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 5 (2014): 543, doi:10.3389/fmicb.2014.00543.Molecular surveys are revealing diverse eukaryotic assemblages in oxygen-limited ocean waters. These communities may play pivotal ecological roles through autotrophy, feeding, and a wide range of symbiotic associations with prokaryotes. We used 18S rRNA gene sequencing to provide the first snapshot of pelagic microeukaryotic community structure in two cellular size fractions (0.2–1.6 ÎŒm, >1.6 ÎŒm) from seven depths through the anoxic oxygen minimum zone (OMZ) off northern Chile. Sequencing of >154,000 amplicons revealed contrasting patterns of phylogenetic diversity across size fractions and depths. Protist and total eukaryote diversity in the >1.6 ÎŒm fraction peaked at the chlorophyll maximum in the upper photic zone before declining by ~50% in the OMZ. In contrast, diversity in the 0.2–1.6 ÎŒm fraction, though also elevated in the upper photic zone, increased four-fold from the lower oxycline to a maximum at the anoxic OMZ core. Dinoflagellates of the Dinophyceae and endosymbiotic Syndiniales clades dominated the protist assemblage at all depths (~40–70% of sequences). Other protist groups varied with depth, with the anoxic zone community of the larger size fraction enriched in euglenozoan flagellates and acantharean radiolarians (up to 18 and 40% of all sequences, respectively). The OMZ 0.2–1.6 ÎŒm fraction was dominated (11–99%) by Syndiniales, which exhibited depth-specific variation in composition and total richness despite uniform oxygen conditions. Metazoan sequences, though confined primarily to the 1.6 ÎŒm fraction above the OMZ, were also detected within the anoxic zone where groups such as copepods increased in abundance relative to the oxycline and upper OMZ. These data, compared to those from other low-oxygen sites, reveal variation in OMZ microeukaryote composition, helping to identify clades with potential adaptations to oxygen-depletion.This work is a contribution of the Center for Microbial Oceanography: Research and Education (C-MORE) and was made possible by generous support from the National Science Foundation (1151698 to Frank J. Stewart and EF0424599 to Edward F. DeLong), the Alfred P. Sloan Foundation (Frank Stewart), the Gordon and Betty Moore Foundation (Edward F. DeLong), and the Agouron Institute (Edward F. DeLong). Edgcomb's involvement was supported by contributions from the Woods Hole Oceanographic Institution Director of Research and Ocean Life Institute

    A review of the current state of the art of physiologically-based tests for measuring human dermal in vitro bioavailability of polycyclic aromatic hydrocarbons (PAH) in soil

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    Polycyclic Aromatic Hydrocarbons are classed as Persistent Organic Pollutants, a large group of compounds that share similar characteristics. They are lipophilic, resistant to degradation in the environment and harmful to human and environmental health. Soil has been identified as the primary reservoir for Polycyclic Aromatic Hydrocarbons in the United Kingdom. This study reviews the literature associated with, or is relevant to, the measurement and modelling of dermal absorption of Polycyclic Aromatic Hydrocarbons from soils. The literature illustrates the use of in vivo, in vitro and in silico methods from a wide variety of scientific disciplines including occupational and environmental exposure, medical, pharmaceutical and cosmetic research and associated mathematical modelling. The review identifies a number of practical shortcomings which must be addressed if dermal bioavailability tests are to be applied to laboratory analysis of contaminated soils for human health risk assessment

    Lower alpha frequency of intraoperative frontal EEG is associated with postoperative delirium: A secondary propensity-matched analysis.

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    BACKGROUND Postoperative delirium (POD) is a serious complication of surgery, especially in the elderly patient population. It has been proposed that decreasing the amount of anesthetics by titrating to an EEG index will lower POD rate, but clear evidence is missing. A strong age-dependent negative correlation has been reported between the peak oscillatory frequency of alpha waves and end-tidal anesthetic concentration, with older patients generating slower alpha frequencies. We hypothesized, that slower alpha oscillations are associated with a higher rate of POD. METHOD Retrospective analysis of patients` data from a prospective observational study in cardiac surgical patients approved by the Bernese Ethics committee. Frontal EEG was recorded during Isoflurane effect-site concentrations of 0.7 to 0.8 and peak alpha frequency was measured at highest power between 6 and 17 Hz. Delirium was assessed by chart review. Demographic and clinical characteristics were compared between POD and non-POD groups. Selection bias was addressed using nearest neighbor propensity score matching (PSM) for best balance. This incorporated 18 variables, whereas patients with missing variable information or without an alpha oscillation were excluded. RESULT Of the 1072 patients in the original study, 828 were included, 73 with POD, 755 without. PSM allowed 328 patients into the final analysis, 67 with, 261 without POD. Before PSM, 8 variables were significantly different between POD and non-POD groups, none thereafter. Mean peak alpha frequency was significantly lower in the POD in contrast to non-POD group before and after matching (7.9 vs 8.9 Hz, 7.9 vs 8.8 Hz respectively, SD 1.3, p < 0.001). CONCLUSION Intraoperative slower frontal peak alpha frequency is independently associated with POD after cardiac surgery and may be a simple intraoperative neurophysiological marker of a vulnerable brain for POD. Further studies are needed to investigate if there is a causal link between alpha frequency and POD
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