5,453 research outputs found
Curvaton Scenario with Affleck-Dine Baryogenesis
We discuss the curvaton scenario with the Affleck-Dine baryogenesis. In this
scenario, non-vanishing baryonic entropy fluctuation may be generated even
without primordial fluctuation of the Affleck-Dine field. Too large entropy
fluctuation is inconsistent with the observations and hence constraints on the
curvaton scenario with the Affleck-Dine baryogenesis are obtained. We calculate
the baryonic entropy fluctuation (as well as other cosmological density
fluctuations) in this case and derive constraints. Implications to some of the
models of the curvaton are also discussed.Comment: 16 pages,2 figure
Bigger is fitter? Quantitative genetic decomposition of selection reveals an adaptive evolutionary decline of body mass in a wild rodent population
This is the final version of the article. Available from the publisher via the DOI in this record.In natural populations, quantitative trait dynamics often do not appear to follow evolutionary predictions. Despite abundant examples of natural selection acting on heritable traits, conclusive evidence for contemporary adaptive evolution remains rare for wild vertebrate populations, and phenotypic stasis seems to be the norm. This so-called "stasis paradox" highlights our inability to predict evolutionary change, which is especially concerning within the context of rapid anthropogenic environmental change. While the causes underlying the stasis paradox are hotly debated, comprehensive attempts aiming at a resolution are lacking. Here, we apply a quantitative genetic framework to individual-based long-term data for a wild rodent population and show that despite a positive association between body mass and fitness, there has been a genetic change towards lower body mass. The latter represents an adaptive response to viability selection favouring juveniles growing up to become relatively small adults, i.e., with a low potential adult mass, which presumably complete their development earlier. This selection is particularly strong towards the end of the snow-free season, and it has intensified in recent years, coinciding which a change in snowfall patterns. Importantly, neither the negative evolutionary change, nor the selective pressures that drive it, are apparent on the phenotypic level, where they are masked by phenotypic plasticity and a non causal (i.e., non genetic) positive association between body mass and fitness, respectively. Estimating selection at the genetic level enabled us to uncover adaptive evolution in action and to identify the corresponding phenotypic selective pressure. We thereby demonstrate that natural populations can show a rapid and adaptive evolutionary response to a novel selective pressure, and that explicitly (quantitative) genetic models are able to provide us with an understanding of the causes and consequences of selection that is superior to purely phenotypic estimates of selection and evolutionary change.The study was funded by a Swiss
National Science Foundation (http://www.snf.ch)
project grant (31003A_141110) awarded to EP
Comparing the effectiveness of small-particle versus large-particle inhaled corticosteroid in COPD
Dirkje S Postma,1 Nicolas Roche,2 Gene Colice,3 Elliot Israel,4 Richard J Martin,5 Willem MC van Aalderen,6 Jonathan Grigg,7 Anne Burden,8 Elizabeth V Hillyer,8 Julie von Ziegenweidt,8 Gokul Gopalan,9 David Price8,10 1University of Groningen, Department of Pulmonary Medicine and Tuberculosis, University Medical Center Groningen, Groningen, the Netherlands; 2Respiratory and Intensive Care Medicine, Cochin Hospital Group, APHP, Paris-Descartes University (EA2511), Paris, France; 3Pulmonary, Critical Care and Respiratory Services, Washington Hospital Center and George Washington University School of Medicine, Washington DC, USA; 4Pulmonary and Critical Care Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; 5Department of Medicine, National Jewish Health, Denver, CO, USA; 6Dept of Pediatric Respiratory Medicine and Allergy, Emma Children's Hospital AMC, Amsterdam, the Netherlands; 7Blizard Institute, Queen Mary University London, London, UK; 8Research in Real Life, Ltd, Cambridge, UK; 9Respiratory, Global Scientific Affairs, Teva Pharmaceuticals, Frazer, PA, USA; 10Academic Primary Care, Division of Applied Health Sciences, University of Aberdeen, Aberdeen, UK Purpose: Small airway changes and dysfunction contribute importantly to airway obstruction in chronic obstructive pulmonary disease (COPD), which is currently treated with inhaled corticosteroids (ICS) and long-acting bronchodilators at Global initiative for Obstructive Lung Disease (GOLD) grades 2–4. This retrospective matched cohort analysis compared effectiveness of a representative small-particle ICS (extrafine beclomethasone) and larger-particle ICS (fluticasone) in primary care patients with COPD. Patients and methods: Smokers and ex-smokers with COPD ≥40 years old initiating or stepping-up their dose of extrafine beclomethasone or fluticasone were matched 1:1 for demographic characteristics, index prescription year, concomitant therapies, and disease severity during 1 baseline year. During 2 subsequent years, we evaluated treatment change and COPD exacerbations, defined as emergency care/hospitalization for COPD, acute oral corticosteroids, or antibiotics for lower respiratory tract infection. Results: Mean patient age was 67 years, 57%–60% being male. For both initiation (n=334:334) and step-up (n=189:189) patients, exacerbation rates were comparable between extrafine beclomethasone and fluticasone cohorts during the 2 year outcome period. Odds of treatment stability (no exacerbation or treatment change) were significantly greater for patients initiating extrafine beclomethasone compared with fluticasone (adjusted odds ratio 2.50; 95% confidence interval, 1.32–4.73). Median ICS dose exposure during 2 outcome years was significantly lower (P<0.001) for extrafine beclomethasone than fluticasone cohorts (315 µg/day versus 436 µg/day for initiation, 438 µg/day versus 534 µg/day for step-up patients). Conclusion: We observed that small-particle ICS at significantly lower doses had comparable effects on exacerbation rates as larger-particle ICS at higher doses, whereas initiation of small-particle ICS was associated with better odds of treatment stability during 2-years' follow-up. Keywords: COPD exacerbation, extrafine particle, matched cohort analysis, real life, small airway
Bodemweerbaarheid als alternatief voor chemie
Bodems die planten beschermen tegen bodemziekten en -plagen? Ze bestaan. De kunst is om dit verschijnsel in alle bodems op te roepen. Stap voor stap ontrafelen onderzoekers van Wageningen UR het mechanisme en ontwikkelen ze praktische toepassingen
Cost benefit and cost effectiveness of antifungal prophylaxis in immunocompromised patients treated for haematological malignancies:reviewing the available evidence
There has been a large increase in the incidence of invasive fungal infections (IFIs) over the past decades, largely because of the increasing size of the population at risk. One of the major risk groups for IFIs are patients with haematological malignancies treated with cytotoxic chemotherapy or undergoing haematopoietic stem cell transplantation. These IFIs are associated with high morbidity and mortality rates. Consequently, as the diagnosis of IFIs is difficult, antifungal prophylaxis is desirable in high-risk patients. Furthermore, as the economic impact of IFIs is also significant, it is important to assess the cost benefit and cost effectiveness of each prophylactic agent in order to aid decisions concerning which prophylactic agent provides the best value for limited healthcare resources. This article systematically reviews the available pharmacoeconomic evidence regarding antifungal prophylaxis in immunocompromised patients treated for haematological malignancies. Furthermore, specific points of interest concerning economic analyses of antifungal prophylaxis are briefly discussed. Considering the available evidence, antifungal prophylaxis in immunocompromised patients treated for haematological malignancies seems to be an intervention with favourable cost-benefit, cost-effectiveness and cost-saving potential. Furthermore, recently introduced antifungal agents seem to be attractive alternatives to fluconazole from a pharmacoeconomic point of view. However, due to wide heterogeneity in patient characteristics, underlying diseases, hospital settings and study methods in the included economic studies, as well as the lack of 'head-to-head' trials, it is difficult to find clear evidence of the economic advantages of a single prophylactic agent. Furthermore, we show that the results of cost-effectiveness analyses are highly dependent on several crucial factors that influence the baseline IFI incidence rates and, therefore, differ per patient population or region
The impact of introducing patient co-payments in Germany on the use of IVF and ICSI:a price-elasticity of demand assessment
BACKGROUND: Authorities concerned by rising healthcare costs have a tendency to target reproductive treatments because of the perception that infertility is a low priority. In 2004 German health authorities introduced a 50% co-payment for patients, in an effort to save cost. We explored the impact of this pricing policy on the utilization of reproductive treatments in Germany. METHODS: Using aggregated annual in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycle data in Germany, we evaluated the relationship between changes in the number of cycles in relation to changes in costs faced by consumers following the introduction of a patient co-payment from 'no fees' to (sic)1500-2000 by estimating the short-run price-elasticity of demand. The impact of introducing patient co-payments for IVF/ICSI on the likelihood of switching to other low-cost fertility treatments was evaluated using the cross-price elasticity methodology. RESULTS: The reduction in demand for IVF and ICSI cycles in the year following the introduction of patient co-payments resulted in elasticities of -0.41 and -0.34, respectively. The price-elasticity for the combined reduction of IVF/ICSI in relation to the co-payment was estimated to be -0.36. The cross-price elasticity for clomifene was close to zero (-0.01) suggesting that demand for these interventions are independent of each other and no substitution occurred. CONCLUSIONS: We report price elasticities for IVF and ICSI of -0.41 and -0.34 after introducing a (sic)1500-2000 co-payment. These findings likely represent short-run elasticities that are likely to vary over time as factors that influence the supply and demand for fertility treatments change
Palaeoflow and Sediment Delivery Reconstructions from Martian Delta Morphology by Combined Modelling and HRSC DTM Analysis
have been formed by sapping. On the left of the delta there is a second lobe that may have formed as an initial drowned delta or alluvial fan. Summary: The size and shape of alluvial fans and deltas contain information on their formative time scale, sediment supply and the amount of water involved. A new numerical morphological model is presented that allows quantitative comparison of morphological predictions and HRSC DTMdata of six deltas. As morphology is uniquely coupled to water and sediment flux, the model also discriminates between dense flows (slurries) and dilute flows (rivers). We demonstrate that two Gilbert (Fig. 1) and three stepped fan deltas may have formed by dilute flows into filling lakes in less than 10 years. Introduction: Alluvial fans and deltas on Mars record past hydrological conditions. Until now these conditions were inferre
Burden of early, advanced and metastatic breast cancer in The Netherlands
BACKGROUND: The aim of this study was to estimate the total economic and health related burden of breast cancer in the Netherlands. METHODS: Data on incidence, prevalence, mortality and survival were extracted from the Dutch National Cancer Registry and were used to calculate the economic and health related burden of breast cancer for overall, DCIS (stage 0), early- (stage I), locally advanced- (stage II-III) and metastatic- (stage IV) breast cancer by age groups and by year (if applicable). RESULTS: The overall incidence of breast cancer increased from 103.4 up to 153.2 per 100,000 women between 1990 and 2014. The increase was driven by DCIS and early breast cancer as the incidence of locally advanced and metastatic breast cancer remained stable. Between 1990 and 2014, ten-year overall survival rates increased from 87% to 93% for early breast cancer, 41% to 62% for locally advanced- and from 6% to 9% for metastatic disease. Annually, breast cancer in the Netherlands is responsible for approximately 3100 deaths, 26,000 life years lost, 65,000 Disability Adjusted Life Years (DALYs) and an economic burden of €1.27 billion. CONCLUSIONS: This study provides a comprehensive assessment of the burden of breast cancer and subsequent trends over time in the Netherlands
M-flation and its spectators
M-flation is an implementation of assisted inflation, in which the inflaton
fields are three N_c x N_c non-abelian hermitean matrices. The model can be
consistently truncated to an effectively single field inflation model, with all
``spectator'' fields fixed at the origin. We show that starting with random
initial conditions for all fields the truncated sector is not a late-time
attractor, but instead the system evolves towards quadratic assisted inflation
with all fields mass degenerate. Demanding the energy density during inflation
to be below the effective quantum gravity scale, we find that the number of
fields, and thus the assisted effect, is bounded N_c < 10^2.Comment: 26 pages, published versio
Parity Violation in Neutron Resonances in 107,109Ag
Parity nonconservation (PNC) was studied in p-wave resonances in Ag by measuring the helicity dependence of the neutron total cross section. Transmission measurements on natural Ag were performed in the energy range 32 to 422 eV with the time-of-flight method at the Manuel Lujan Neutron Scattering Center at Los Alamos National Laboratory. A total of 15 p-wave neutron resonances were studied in 107Ag and ninep-wave resonances in 109Ag. Statistically significant asymmetries were observed for eight resonances in 107Ag and for four resonances in109Ag. An analysis treating the PNC matrix elements as random variables yields a weak spreading width of Γw=(2.67-1.21+2.65)×10-7 eV for107Ag and Γw=(1.30-0.74+2.49)×10-7 eV for 109Ag
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