2,330 research outputs found

    How Sales Taxes Affect Customer and Firm Behavior: The Role of Search on the Internet

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    When a multichannel retailer opens its first retail store in a state, the firm is obligated to collect sales taxes on all Internet and catalog orders shipped to that state. This article assesses how opening a store affects Internet and catalog demand. The authors analyze purchase behavior among customers who live far from the retail store but must now pay sales taxes on catalog and Internet purchases. A comparable group of customers in a neighboring state serves as a control. The results show that Internet sales decrease significantly, but catalog sales are unaffected. Further investigation indicates that the difference in these outcomes is partly attributable to the ease with which customers can search for lower prices at competing retailers. The authors extend the analysis to a panel of multichannel firms and show that retailers that earn a large proportion of their revenue from direct channels avoid opening a first store in high-tax states. They conclude that current U.S. sales taxes laws have significant effects on both customer and firm behavior

    A Study of the Quasi-elastic (e,e'p) Reaction on 12^{12}C, 56^{56}Fe and 97^{97}Au

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    We report the results from a systematic study of the quasi-elastic (e,e'p) reaction on 12^{12}C, 56^{56}Fe and 197^{197}Au performed at Jefferson Lab. We have measured nuclear transparency and extracted spectral functions (corrected for radiation) over a Q2^2 range of 0.64 - 3.25 (GeV/c)2^2 for all three nuclei. In addition we have extracted separated longitudinal and transverse spectral functions at Q2^2 of 0.64 and 1.8 (GeV/c)2^2 for these three nuclei (except for 197^{197}Au at the higher Q2^2). The spectral functions are compared to a number of theoretical calculations. The measured spectral functions differ in detail but not in overall shape from most of the theoretical models. In all three targets the measured spectral functions show considerable excess transverse strength at Q2^2 = 0.64 (GeV/c)2^2, which is much reduced at 1.8 (GeV/c)2^2.Comment: For JLab E91013 Collaboration, 19 pages, 20 figures, 3 table

    Iron Deficiency and the Well-being of Older Adults: Early Results From a Randomized Nutrition Intervention

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    Iron deficiency is widespread throughout the developing world. We provide new evidence on the effect of iron deficiency on economic and social prosperity of older adults drawing on data from a random assignment treatment-control design intervention. The Work and Iron Status Evaluation is an on-going study following over 17,000 individuals in Central Java, Indonesia. Half the respondents receive a treatment of 120 mg of iron every week for a year; the controls receive a placebo. Compliance is monitored carefully. Results from the first six months of the intervention are presented for adults age 30 through 70 years. Males who were iron deficient prior to the intervention and who are assigned to the treatment are better off in terms of physical health, psycho-social health and economic success. These men are more likely to be working, sleep less, lose less work time to illness, are more energetic, more able to conduct physically arduous activities and their psycho-social health is better. There is evidence that economic productivity of these males also increased. Among iron-deficient males assigned to the treatment who were also self-employed prior to the baseline, hourly earnings rose substantially and so they earned more on a monthly basis. Benefits for women are in the same direction but the effects are more muted. The results provide unambiguous evidence in support of the hypothesis that health has a causal effect on economic prosperity of males during middle and older ages

    Complete Genome Sequences of Chop, DelRio, and GrandSlam, Three Gordonia Phages Isolated from Soil in Central Arkansas

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    Chop, DelRio, and GrandSlam are phage with a Siphoviridae morphotype isolated from soil in Arkansas using the host Gordonia terrae 3612. All three are temperate, and their genomes share at least 96% nucleotide identity. These phage are assigned to cluster DI based on gene content similarity to other sequenced actinobacteriophage

    Radiological response heterogeneity is of prognostic significance in metastatic renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy

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    Background: Response evaluation criteria in solid tumours (RECIST) is widely used to assess tumour response but is limited by not considering disease site or radiological heterogeneity (RH). Objective: To determine whether RH or disease site has prognostic significance in patients with metastatic clear-cell renal cell carcinoma (ccRCC). Design, setting, and participants: A retrospective analysis was conducted of a second-line phase II study in patients with metastatic ccRCC (NCT00942877), evaluating 138 patients with 458 baseline lesions. Intervention: The phase II trial assessed vascular endothelial growth factor-targeted therapy ± Src inhibition. Outcome measurements and statistical analysis: RH at week 8 was assessed within individual patients with two or more lesions to predict overall survival (OS) using Kaplan-Meier method and Cox regression model. We defined a high heterogeneous response as occurring when one or more lesion underwent a ≥10% reduction and one or more lesion underwent a ≥10% increase in size. Disease progression was defined by RECIST 1.1 criteria. Results and limitations: In patients with a complete/partial response or stable disease by RECIST 1.1 and two or more lesions at week 8, those with a high heterogeneous response had a shorter OS compared to those with a homogeneous response (hazard ratio [HR] 2.01; 95% confidence interval [CI]: 1.39–2.92; p < 0.001). Response by disease site at week 8 did not affect OS. At disease progression, one or more new lesion was associated with worse survival compared with >20% increase in sum of target lesion diameters only (HR 2.12; 95% CI: 1.43–3.14; p < 0.001). Limitations include retrospective study design. Conclusions: RH and the development of new lesions may predict survival in metastatic ccRCC. Further prospective studies are required. Patient summary: We looked at individual metastases in patients with kidney cancer and showed that a variable response to treatment and the appearance of new metastases may be associated with worse survival. Further studies are required to confirm these findings

    CAMEMBERT: A Mini-Neptunes GCM Intercomparison, Protocol Version 1.0. A CUISINES Model Intercomparison Project

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    With an increased focus on the observing and modelling of mini-Neptunes, there comes a need to better understand the tools we use to model their atmospheres. In this paper, we present the protocol for the CAMEMBERT (Comparing Atmospheric Models of Extrasolar Mini-neptunes Building and Envisioning Retrievals and Transits) project, an intercomparison of general circulation models (GCMs) used by the exoplanetary science community to simulate the atmospheres of mini-Neptunes. We focus on two targets well studied both observationally and theoretically with planned JWST Cycle 1 observations: the warm GJ~1214b and the cooler K2-18b. For each target, we consider a temperature-forced case, a clear sky dual-grey radiative transfer case, and a clear sky multi band radiative transfer case, covering a range of complexities and configurations where we know differences exist between GCMs in the literature. This paper presents all the details necessary to participate in the intercomparison, with the intention of presenting the results in future papers. Currently, there are eight GCMs participating (ExoCAM, Exo-FMS, FMS PCM, Generic PCM, MITgcm, RM-GCM, THOR, and the UM), and membership in the project remains open. Those interested in participating are invited to contact the authors.Comment: Accepted to PS

    Measurements of Deuteron Photodisintegration up to 4.0 GeV

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    The first measurements of the differential cross section for the d(gamma,p)n reaction up to 4.0 GeV were performed at Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. We report the cross sections at the proton center-of-mass angles of 36, 52, 69 and 89 degrees. These results are in reasonable agreement with previous measurements at lower energy. The 89 and 69 degree data show constituent-counting-rule behavior up to 4.0 GeV photon energy. The 36 and 52 degree data disagree with the counting rule behavior. The quantum chromodynamics (QCD) model of nuclear reactions involving reduced amplitudes disagrees with the present data.Comment: 5 pages (REVTeX), 1 figure (postscript

    The HLA class II allele DRB1*1501 is over-represented in patients with idiopathic pulmonary fibrosis

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    Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and medically refractory lung disease with a grim prognosis. Although the etiology of IPF remains perplexing, abnormal adaptive immune responses are evident in many afflicted patients. We hypothesized that perturbations of human leukocyte antigen (HLA) allele frequencies, which are often seen among patients with immunologic diseases, may also be present in IPF patients. Methods/Principal Findings: HLA alleles were determined in subpopulations of IPF and normal subjects using molecular typing methods. HLA-DRB1*15 was over-represented in a discovery cohort of 79 Caucasian IPF subjects who had lung transplantations at the University of Pittsburgh (36.7%) compared to normal reference populations. These findings were prospectively replicated in a validation cohort of 196 additional IPF subjects from four other U.S. medical centers that included both ambulatory patients and lung transplantation recipients. High-resolution typing was used to further define specific HLA-DRB1*15 alleles. DRB1*1501 prevalence in IPF subjects was similar among the 143 ambulatory patients and 132 transplant recipients (31.5% and 34.8%, respectively, p = 0.55). The aggregate prevalence of DRB1*1501 in IPF patients was significantly greater than among 285 healthy controls (33.1% vs. 20.0%, respectively, OR 2.0; 95%CI 1.3-2.9, p = 0.0004). IPF patients with DRB1*1501 (n = 91) tended to have decreased diffusing capacities for carbon monoxide (DLCO) compared to the 184 disease subjects who lacked this allele (37.8±1.7% vs. 42.8±1.4%, p = 0.036). Conclusions/Significance: DRB1*1501 is more prevalent among IPF patients than normal subjects, and may be associated with greater impairment of gas exchange. These data are novel evidence that immunogenetic processes can play a role in the susceptibility to and/or manifestations of IPF. Findings here of a disease association at the HLA-DR locus have broad pathogenic implications, illustrate a specific chromosomal area for incremental, targeted genomic study, and may identify a distinct clinical phenotype among patients with this enigmatic, morbid lung disease

    The Structure of the Homunculus. II. Modeling the physical conditions in Eta Car's molecular shell

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    We present models that reproduce the observed double-shell structure of the Homunculus Nebula around eta Carinae, including the stratification of infrared H2 and [FeII] emission seen in data obtained with the Phoenix spectrograph on Gemini South, as well as the corresponding stratified grain temperature seen in thermal-infrared data. Tuning the model to match the observed shell thickness allows us to determine the threshold density which permits survival of H2. An average hydrogen density of n_H=(0.5-1)x10^7 cm-3 in the outer zone is required to allow H2 to exist at all latitudes in the nebula, and for Fe+ to recombine. This gives independent confirmation of the very large mass of the Homunculus, indicating a total of roughly 15--35 Msun (although we note reasons why the lower end of this range is favored). At the interface between the atomic and molecular zones, we predict a sharp drop in the dust temperature, in agreement with the bimodal dust color temperatures observed in the two zones. In the outer molecular shell, the dust temperature drops to nearly the blackbody temperature, and becomes independent of grain size because of self-shielding at shorter UV wavelengths and increased heating at longer wavelengths. This relaxes constraints on large grain sizes suggested by near-blackbody color temperatures. Finally, from the strength of infrared [FeII] emission in the inner shell we find that the gas-phase Fe abundance is roughly solar. This is astonishing in such a dusty object, where one normally expects gaseous iron to be depleted by two orders of magnitude.Comment: 18 pages, 5 figures. Accepted by Ap
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