Does Gibrat’s Law Hold for Retailing? Evidence from Sweden

Gibrat’s Law predicts that firm growth is a purely random effect and therefore should be independent of firm size. The purpose of this paper is to test Gibrat’s law within the retail industry, using a novel data-set comprising all Swedish limited liability companies active at some point between 1998 and 2004. Very few studies have previously investigated whether Gibrat’s Law seems to hold for retailing, and they are based on highly aggregated data. Our results indicate that Gibrat´s Law can be rejected for a large majority of five-digit retail industries in Sweden, since small retail firms tend to grow faster than large ones.firm dynamics; firm size; firm growth; retail

Biaxial tensile tests identify epidermis and hypodermis as the main structural elements of sweet cherry skin

The skin of developing soft and fleshy fruit is subjected to considerable growth stress, and failure of the skin is associated with impaired barrier properties in water transport and pathogen defence. The objectives were to establish a standardized, biaxial tensile test of the skin of soft and fleshy fruit and to use it to characterize and quantify mechanical properties of the sweet cherry (Prunus avium) fruit skin as a model. A segment of the exocarp (ES) comprising cuticle, epidermis, hypodermis and adhering flesh was mounted in the elastometer such that the in vivo strain was maintained. The ES was pressurized from the inner surface and the pressure and extent of associated bulging were recorded. Pressure: strain responses were almost linear up to the point of fracture, indicating that the modulus of elasticity was nearly constant. Abrading the cuticle decreased the fracture strain but had no effect on the fracture pressure. When pressure was held constant, bulging of the ES continued to increase. Strain relaxation upon releasing the pressure was complete and depended on time. Strains in longitudinal and latitudinal directions on the bulging ES did not differ significantly. Exocarp segments that released their in vivo strain before the test had higher fracture strains and lower moduli of elasticity. The results demonstrate that the cherry skin is isotropic in the tangential plane and exhibits elastic and viscoelastic behaviour. The epidermis and hypodermis, but not the cuticle, represent the structural 'backbone' in a cherry skin. This test is useful in quantifying the mechanical properties of soft and fleshy fruit of a range of species under standardized conditions.DFG/KN402/8-

Subcomponent self-assembly of circular helical Dy6_{6}(L)6_{6} and bipyramid Dy12_{12}(L)8_{8} architectures directed via second-order template effects

In situ metal-templated (hydrazone) condensation also called subcomponent self-assembly of 4,6-dihydrazino-pyrimidine, o-vanillin and dysprosium ions resulted in the formation of discrete hexa- or dodecanuclear metallosupramolecular Dy$_{6}$(L)$_{6}$ or Dy$_{12}$(L)$_{8}$ aggregates resulting from second-order template effects of the base and the lanthanide counterions used in these processes. XRD analysis revealed unique circular helical or tetragonal bipyramid architectures in which the bis(hydrazone) ligand L adopts different conformations and shows remarkable differences in its mode of metal coordination. While a molecule of trimethylamine acts as a secondary template that fills the void of the Dy$_{6}$(L)$_{6}$ assembly, sodium ions take on this role for the formation of heterobimetallic Dy$_{12}$(L)$_{8}$ by occupying vacant coordination sites, thus demonstrating that these processes can be steered in different directions upon subtle changes of reaction conditions. Furthermore, Dy$_{6}$(L)$_{6}$ shows an interesting spin-relaxation energy barrier of 435 K, which is amongst the largest values within multinuclear lanthanide single-molecular magnets

Leukoencephalopathy after prophylactic whole-brain irradiation with or without hippocampal sparing: a longitudinal magnetic resonance imaging analysis

PURPOSE Neurocognitive changes are well described after prophylactic or therapeutic whole-brain radiotherapy (WBRT) and have been reported as early as 3 months after radiotherapy (RT). Therefore, WBRT with protection of the hippocampal region (hippocampal avoidance, HA) has been proposed to preserve neurocognition. Our aim was to compare the risk of leukoencephalopathy after prophylactic cranial irradiation (PCI) with or without HA. METHODS Patients with small-cell lung cancer who received either lateral-opposed field PCI (non-HA-PCI; n = 9) or hippocampus avoidance PCI (HA-PCI; n = 9) with available magnetic resonance imaging (MRI) follow-up were identified and age matched. Pre-therapeutic and follow-up MRI after RT was analysed for leukoencephalopathy based on the Fazekas score. Bilateral cortical and subcortical brain structures were segmented and analysed for alterations in dosimetric parameters and volumes. RESULTS There was no significant difference of Fazekas scores between groups at baseline. Fazekas score differed in post-treatment with a median of 1 in the HA-PCI group and 2 in the non-HA-PCI group (p = 0.007). Significant increase of Fazekas score over time after RT was observed for HA-PCI patients (p = 0.001) but not for non-HA-PCI patients. Dmax (highest radiation dose) and brain volume receiving doses >25Gy were higher in HA-PCI patients. There were no significant volumetric differences for segmented brain structures between groups. CONCLUSION Radiological changes are more prominent after HA-PCI than after non-HA-PCI. Although no standardised neurocognitive testing was performed, the significantly increased Fazekas scores after HA-PCI are expected to interfere with neurocognitive function. Prospective long-term neurocognitive studies are warranted before HA-PCI is implemented in routine clinical practice

Evaluating key characteristics of ideal colorectal cancer screening modalities: the microsimulation approach.

BACKGROUND AND AIMS Screening for colorectal cancer (CRC) can effectively reduce CRC incidence and mortality. Besides colonoscopy, tests for the detection of biomarkers in stool, blood, or serum, including the fecal immunochemical test (FIT), ColoGuard, Epi proColon, and PolypDx, have recently been advanced. We aimed to identify the characteristics of theoretic, highly efficient screening tests and calculated the effectiveness and cost effectiveness of available screening tests. METHODS Using the microsimulation-based colon modeling open-source tool (CMOST), we simulated 142,501 theoretic screening tests with variable assumptions for adenoma and carcinoma sensitivity, specificity, test frequency, and adherence, and we identified highly efficient tests outperforming colonoscopy. For available screening tests, we simulated 10 replicates of a virtual population of 2 million individuals, using epidemiologic characteristics and costs assumptions of the United States. RESULTS Highly efficient theoretic screening tests were characterized by high sensitivity for advanced adenoma and carcinoma and high patient adherence. All simulated available screening tests were effective at 100% adherence to screening and at expected real-world adherence rates. All tests were cost effective below the threshold of 100,000 U.S. dollars per life year gained. With perfect adherence, FIT was the most effective and cost-efficient intervention, whereas Epi proColon was the most effective at expected real-world adherence rates. In our sensitivity analysis, assumptions for patient adherence had the strongest impact on effectiveness of screening. CONCLUSIONS Our microsimulation study identified characteristics of highly efficient theoretic screening tests and confirmed the effectiveness and cost-effectiveness of colonoscopy and available urine-, blood-, and stool-based tests. Better patient adherence results in superior effectiveness for CRC prevention in the whole population

Programmable quantum simulation of 2D antiferromagnets with hundreds of Rydberg atoms

Quantum simulation using synthetic systems is a promising route to solve outstanding quantum many-body problems in regimes where other approaches, including numerical ones, fail. Many platforms are being developed towards this goal, in particular based on trapped ions, superconducting circuits, neutral atoms or molecules. All of which face two key challenges: (i) scaling up the ensemble size, whilst retaining high quality control over the parameters and (ii) certifying the outputs for these large systems. Here, we use programmable arrays of individual atoms trapped in optical tweezers, with interactions controlled by laser-excitation to Rydberg states to implement an iconic many-body problem, the antiferromagnetic 2D transverse field Ising model. We push this platform to an unprecedented regime with up to 196 atoms manipulated with high fidelity. We probe the antiferromagnetic order by dynamically tuning the parameters of the Hamiltonian. We illustrate the versatility of our platform by exploring various system sizes on two qualitatively different geometries, square and triangular arrays. We obtain good agreement with numerical calculations up to a computationally feasible size (around 100 particles). This work demonstrates that our platform can be readily used to address open questions in many-body physics.Comment: Main text: 6 pages, 4 figures. Supplementary information: 10 pages, 16 figure

Because I'm happy - positive affect and its predictive value for future disease activity in patients with inflammatory bowel diseases: a retrospective cohort study

BACKGROUND: While the detrimental impact of negative emotions on the clinical course of inflammatory bowel disease (IBD) and quality of life has been extensively investigated, evidence for a potential impact of positive emotions is scarce. OBJECTIVES: We aim to analyse contributing factors of positive affect and their predictive value for disease course in IBD patients. DESIGN: In this retrospective cohort study, epidemiological, psychosocial and IBD disease characteristics of Swiss IBD cohort study patients were analysed longitudinally. METHODS: Epidemiological, psychosocial and disease characteristics were extracted from the database of the Swiss IBD cohort study. Participants' positive emotions were assessed cross-sectionally with the seven-item Marburg questionnaire (range 1-6) addressing positive affect in different aspects of daily life. Predictors of positive emotions were identified by linear regression. The quantitative longitudinal impact of positive emotions on the further disease course was analysed using a multivariable Cox proportional hazards model. RESULTS: Among 702 IBD patients, those reporting more positive emotions were found to have significantly less intense medical treatment, less pain and fewer depressive symptoms (p  3.5) experienced longer flare-free survival, also after adjusting for confounders (adjusted hazard ratio: 0.39, p < 0.05). CONCLUSIONS: The absence of pain and depressive symptoms were the strongest drivers for high positive affect. Higher scores of positive affect were associated with longer disease-free survival in IBD patients

The personality traits activity, self-reproach, and negative affect jointly predict clinical recurrence, depressive symptoms, and low quality of life in inflammatory bowel disease patients.

BACKGROUND The bidirectional "gut-brain axis" has been implicated in the pathogenesis of inflammatory bowel diseases (IBD). While the influence of stress and depressive symptoms on IBD is well-characterized, the role of personality remains insufficiently investigated. METHODS Personality was assessed in 1154 Swiss IBD cohort study (SIBDCS) patients via the NEO-Five-Factor Inventory (NEO-FFI) as well as in 2600 participants of the population-based CoLaus¦PsyCoLaus cohort study (NEO-FFI-revised). The NEO-FFI subcomponents activity, self-reproach and negative affect were associated with higher IBD disease activity and were combined to a NEO-FFI risk score. This risk score was validated and its effect on clinical IBD course and psychological endpoints was analysed in time-to-event and cumulative incidence analyses. RESULTS In time-to-event analyses, a high NEO-FFI risk score was predictive for the clinical endpoints of new extraintestinal manifestation [EIM, adjusted hazard ratio (aHR) = 1.64, corrected p value (q) = 0.036] and two established composite flare endpoints (aHR = 1.53-1.63, q = 0.003-0.006) as well as for the psychological endpoints depressive symptoms (aHR = 7.06, q < 0.001) and low quality of life (aHR = 3.06, q < 0.001). Furthermore, cumulative incidence analyses showed that patients at high NEO-FFI risk experienced significantly more episodes of active disease, new EIMs, one of the flare endpoints, depressive episodes and low disease-related quality of life. Personalities of IBD patients showed only minor differences from the general population sample (Pearson's r = 0.03-0.14). CONCLUSIONS Personality assessed by the NEO-FFI contained considerable predictive power for disease recurrence, depressive symptoms and low quality of life in IBD patients. Nevertheless, the personalities of IBD patients did not substantially differ from the general population

LOFAR/H-ATLAS: The low-frequency radio luminosity - star-formation rate relation

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.Radio emission is a key indicator of star-formation activity in galaxies, but the radio luminosity-star formation relation has to date been studied almost exclusively at frequencies of 1.4 GHz or above. At lower radio frequencies the effects of thermal radio emission are greatly reduced, and so we would expect the radio emission observed to be completely dominated by synchrotron radiation from supernova-generated cosmic rays. As part of the LOFAR Surveys Key Science project, the Herschel-ATLAS NGP field has been surveyed with LOFAR at an effective frequency of 150 MHz. We select a sample from the MPA-JHU catalogue of SDSS galaxies in this area: the combination of Herschel, optical and mid-infrared data enable us to derive star-formation rates (SFRs) for our sources using spectral energy distribution fitting, allowing a detailed study of the low-frequency radio luminosity--star-formation relation in the nearby Universe. For those objects selected as star-forming galaxies (SFGs) using optical emission line diagnostics, we find a tight relationship between the 150 MHz radio luminosity ($L_{150}$) and SFR. Interestingly, we find that a single power-law relationship between $L_{150}$ and SFR is not a good description of all SFGs: a broken power law model provides a better fit. This may indicate an additional mechanism for the generation of radio-emitting cosmic rays. Also, at given SFR, the radio luminosity depends on the stellar mass of the galaxy. Objects which were not classified as SFGs have higher 150-MHz radio luminosity than would be expected given their SFR, implying an important role for low-level active galactic nucleus activity.Peer reviewedFinal Published versio

The personality traits activity, self-reproach, and negative affect jointly predict clinical recurrence, depressive symptoms, and low quality of life in inflammatory bowel disease patients

BACKGROUND The bidirectional "gut-brain axis" has been implicated in the pathogenesis of inflammatory bowel diseases (IBD). While the influence of stress and depressive symptoms on IBD is well-characterized, the role of personality remains insufficiently investigated. METHODS Personality was assessed in 1154 Swiss IBD cohort study (SIBDCS) patients via the NEO-Five-Factor Inventory (NEO-FFI) as well as in 2600 participants of the population-based CoLaus¦PsyCoLaus cohort study (NEO-FFI-revised). The NEO-FFI subcomponents activity, self-reproach and negative affect were associated with higher IBD disease activity and were combined to a NEO-FFI risk score. This risk score was validated and its effect on clinical IBD course and psychological endpoints was analysed in time-to-event and cumulative incidence analyses. RESULTS In time-to-event analyses, a high NEO-FFI risk score was predictive for the clinical endpoints of new extraintestinal manifestation [EIM, adjusted hazard ratio (aHR) = 1.64, corrected p value (q) = 0.036] and two established composite flare endpoints (aHR = 1.53-1.63, q = 0.003-0.006) as well as for the psychological endpoints depressive symptoms (aHR = 7.06, q < 0.001) and low quality of life (aHR = 3.06, q < 0.001). Furthermore, cumulative incidence analyses showed that patients at high NEO-FFI risk experienced significantly more episodes of active disease, new EIMs, one of the flare endpoints, depressive episodes and low disease-related quality of life. Personalities of IBD patients showed only minor differences from the general population sample (Pearson's r = 0.03-0.14). CONCLUSIONS Personality assessed by the NEO-FFI contained considerable predictive power for disease recurrence, depressive symptoms and low quality of life in IBD patients. Nevertheless, the personalities of IBD patients did not substantially differ from the general population