Price setting in a leading Swiss online supermarket

We study a newly released data set of scanner prices for food products in a large Swiss online supermarket. We find that average prices change about every two months, but when we exclude temporary sales, prices are extremely sticky, changing on average once every three years. Non-sale price behavior is broadly consistent with menu cost models of sticky prices. When we focus specifically on the behavior of sale prices, however, we find that the characteristics of price adjustment seems to be substantially at odds with standard theory.Pricing ; Profit

Price setting in a leading Swiss online supermarket

We study a newly released data set of scanner prices for food products in a large Swiss online supermarket. We find that average prices change about every two months, but when we exclude temporary sales, prices are extremely sticky, changing on average once every three years. Non-sale price behavior is broadly consistent with menu cost models of sticky prices. When we focus specifically on the behavior of sale prices, however, we find that the characteristics of price adjustment seems to be substantially at odds with standard theory

Price Setting in a Leading Swiss Online Supermarket

We study a newly released data set of scanner prices for food products in a large Swiss online supermarket. We find that average prices change about every two months, but when we exclude temporary sales, prices are extremely sticky, changing on average once every three years. Non-sale price behavior is broadly consistent with menu cost models of sticky prices. When we focus specifically on the behavior of sale prices, however, we find that the characteristics of price adjustment seems to be substantially at odds with standard theory.

Revised masses of dust and gas of SLUGS FIR bright galaxies based on a recent CO survey

Recent CO measurements of an essentially complete sub-sample of galaxies from the SCUBA Local Universe Survey (SLUGS) are used to examine their implications for dust and gas masses in this sample. Estimates of dust masses are affected by a contribution to the SCUBA brightness measurements by CO(3-2) emission, and molecular gas masses by the use of a modified value of the CO-to-H_2 conversion factor X. The average dust mass is reduced by 25-38 per cent, which has no bearing on earlier conclusions concering the shapes of the dust mass luminosity function derived from the SLUGS. The value of X found from the CO survey, when applied together with the reduction in dust masses, leads to lower estimates for the mean gas-to-dust mass ratios, where the gas includes both H_2 and HI. For the CO sample, the mean global ratio is reduced from approximately 430 to about 320-360, but is further reduced to values near 50 when applied to the nuclear regions relevant to the CO observations. We discuss these results and suggest that the differences between the nuclear and outer regions may simply reflect differences in metallicity or the existence of considerable amounts of unobserved cold dust in the outer regions of these galaxiies.Comment: 18 pages, 2 tables, 4 figures, accepted for publication in MNRA

The Origin of the Hubble Sequence in Lambda-CDM Cosmology

The Galform semi-analytic model of galaxy formation is used to explore the mechanisms primarily responsible for the three types of galaxies seen in the local universe: bulge, bulge+disk and disk, identified with the visual morphological types E, S0/a-Sbc, and Sc-Scd, respectively. With a suitable choice of parameters the Galform model can accurately reproduce the observed local K_s-band luminosity function (LF) for galaxies split by visual morphological type. The successful set of model parameters is used to populate the Millennium Simulation with 9.4 million galaxies and their dark matter halos. The resulting catalogue is then used to explore the evolution of galaxies through cosmic history. The model predictions concur with recent observational results including the galaxy merger rate, the star formation rate and the seemingly anti-hierarchical evolution of ellipticals. However, the model also predicts significant evolution of the elliptical galaxy LF that is not observed. The discrepancy raises the possibility that samples of z~1 galaxies which have been selected using colour and morphological criteria may be contaminated with galaxies that are not actually ellipticals.Comment: Accepted for publication in MNRAS. Missing reference adde

Climate Change, Food Security and Disaster Risk Management: Issues paper for the Expert Meeting on Climate Change and Disaster Risk Management, FAO, Rome, 28-29 February 2008

In late 2007, the Intergovernmental Panel on Climate Change released their fourth Assessment Report (AR4), drawing together the scientific evidence on climate change. This report states unequivocally the manifold evidence that climate change is occurring. Global average air temperatures are rising, with eleven of the last twelve years (1995-2006) ranking amongst the twelve warmest years in the instrumental record of global surface temperatur

Quantitative planar and volumetric cardiac measurements using 64 mdct and 3t mri vs. Standard 2d and m-mode echocardiography: does anesthetic protocol matter?

Cross‐sectional imaging of the heart utilizing computed tomography and magnetic resonance imaging (MRI) has been shown to be superior for the evaluation of cardiac morphology and systolic function in humans compared to echocardiography. The purpose of this prospective study was to test the effects of two different anesthetic protocols on cardiac measurements in 10 healthy beagle dogs using 64‐multidetector row computed tomographic angiography (64‐MDCTA), 3T magnetic resonance (MRI) and standard awake echocardiography. Both anesthetic protocols used propofol for induction and isoflourane for anesthetic maintenance. In addition, protocol A used midazolam/fentanyl and protocol B used dexmedetomedine as premedication and constant rate infusion during the procedure. Significant elevations in systolic and mean blood pressure were present when using protocol B. There was overall good agreement between the variables of cardiac size and systolic function generated from the MDCTA and MRI exams and no significant difference was found when comparing the variables acquired using either anesthetic protocol within each modality. Systolic function variables generated using 64‐MDCTA and 3T MRI were only able to predict the left ventricular end diastolic volume as measured during awake echocardiogram when using protocol B and 64‐MDCTA. For all other systolic function variables, prediction of awake echocardiographic results was not possible (P = 1). Planar variables acquired using MDCTA or MRI did not allow prediction of the corresponding measurements generated using echocardiography in the awake patients (P = 1). Future studies are needed to validate this approach in a more varied population and clinically affected dogs

Comparison of m-mode echocardiographic left ventricular mass measured using digital and strip chart readings: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND: Epidemiological and clinical studies frequently use echocardiography to measure LV wall thicknesses and chamber dimension for estimating quantitative measures of LV mass. While echocardiographic M-mode LV images have traditionally been measured using hand-held calipers and strip-chart paper tracings, digitized M-mode LV image measurements made directly on the computer screen using electronic calipers have become standard practice. We sought to determine if systematic differences in LV mass occur between the two methods by comparing LV mass measured from simultaneous M-mode strip chart recordings and digitized recordings. METHODS: The Atherosclerosis Risk in Communities study applied the latter method. To determine if systematic differences in LV mass occur between the two methods, LV mass was measured from simultaneous M-mode strip chart recordings and digitized recordings. RESULTS: We found no difference in LV mass (p > .25) and a strong correlation in LV mass between the two methods (r = 0.97). Neither age, sex, nor hypertension status affected the correlation of LV mass between the two methods. CONCLUSIONS: We conclude that digital estimates of LV mass provide unbiased estimates comparable to the strip-chart method

Agreement among optometrists and ophthalmologists in estimating limbal anterior chamber depth using the van Herick method

Purpose To evaluate the inter-observer agreement for measuring limbal anterior chamber depth (LACD) using the van Herick test in community optometrists, glaucoma specialist optometrists and ophthalmologists. Methods The study was divided into two phases. In the first phase, a random sample of 100 UK community optometrists were given an opportunity to select and grade eight digital slit-lamp images of anterior chamber angles using the original van Herick 4 point grading scale. The images were included in a clinical decision making study using computerised virtual case vignettes. In the second phase, hospital-based glaucoma specialist optometrists and glaucoma sub-specialist ophthalmologists graded the LACD of the right eye using a 7-point % grading scale in 57 consecutively presenting patients with suspect glaucoma. Inter-observer agreement was assessed using linearly weighted kappa (κw). Results Inter-observer agreement for community optometrists was moderate, with a mean κw for grading photographic images of 0.50 (95% confidence interval (CI) 0.43–0.57). Overall, ninety-two percent of observations were within one grade of the actual grade, although grading of narrow angles was associated with a 13% false negative error rate (based on a ≤ grade 2 threshold). For Phase 2 of the study, pairwise comparisons between optometrists and ophthalmologists showed that agreement was moderate to substantial (mean κw = 0.54–0.65) with a false negative rate of 1.9% (based on a ≤ 25% threshold). Grading accuracy of specialist optometrists and ophthalmologists were equivalent. Conclusions In summary, the present study found that community optometrists showed moderate inter-observer agreement for grading LACD. Glaucoma specialist optometrists showed moderate to substantial agreement with weighted kappa values that were equivalent to sub-specialist ophthalmologists. The augmented 7-point % grading scale is intuitive and potentially offers greater accuracy for grading narrow angles than the traditional 4-point scale for grading LACD