1,038 research outputs found

    The impact of Arctic sea ice on the Arctic energy budget and on the climate of the Northern mid-latitudes

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    The atmospheric general circulation model EC-EARTH-IFS has been applied to investigate the influence of both a reduced and a removed Arctic sea ice cover on the Arctic energy budget and on the climate of the Northern mid-latitudes. Three 40-year simulations driven by original and modified ERA-40 sea surface temperatures and sea ice concentrations have been performed at T255L62 resolution, corresponding to 79 km horizontal resolution. Simulated changes between sensitivity and reference experiments are most pronounced over the Arctic itself where the reduced or removed sea ice leads to strongly increased upward heat and longwave radiation fluxes and precipitation in winter. In summer, the most pronounced change is the stronger absorption of shortwave radiation which is enhanced by optically thinner clouds. Averaged over the year and over the area north of 70° N, the negative energy imbalance at the top of the atmosphere decreases by about 10 W/m2 in both sensitivity experiments. The energy transport across 70° N is reduced. Changes are not restricted to the Arctic. Less extreme cold events and less precipitation are simulated in sub-Arctic and Northern mid-latitude regions in winter

    Green bonds, transition to a low-carbon economy, and intergenerational fairness: Evidence from an extended DICE model

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    Perceived intergenerational unfairness is one of the obstacles for a rapid transition to a low carbon economy whereby current generations have to carry the burden of paying for mitigation, while the next generations will enjoy the benefits for free. Green bonds are believed to be able to distribute the burdens over generations more evenly. In this paper, we examine whether green bonds can indeed resolve the intergenerational inequity challenge. To do so, we employ the DICE model and supplement it with bonds and green tax through which future generations repay the debt. We show that bonds can reduce but cannot completely eliminate the intergenerational inequities. Lower interest rates shorten the initial time period when the society is worse off if a mitigation policy is implemented. Additional compensation mechanisms ensuring that the current generation retains the consumption level equal to the one without mitigation are needed to achieve a Pareto improvement of the mitigation scenario for all generations

    Stock market, interest rate and output: a model and estimation for US time series data

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    Stock market, interest rate and output: a model and estimation for US time series dat

    Extended-spectrum β-lactamase-producing and AmpC-producing Escherichia coli from livestock and companion animals, and their putative impact on public health: a global perspective

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    AbstractThe possible zoonotic spread of antimicrobial-resistant bacteria is controversial. This review discusses global molecular epidemiological data combining both analyses of the chromosomal background, using multilocus sequence typing (MLST), and analyses of plasmid (episomal) extended-spectrum β-lactamase (ESBL)/AmpC genes in Escherichia coli present in humans and animals. For consideration of major epidemiological differences, animals were separated into livestock and companion animals. MLST revealed the existence of ESBL-producing isolates thoughout the E. coli population, with no obvious association with any ancestral EcoR group. A similar distribution of major ESBL/AmpC types was apparent only in human isolates, regardless of their geographical origin from Europe, Asia, or the Americas, whereas in animals this varied extensively between animal groups and across different geographical areas. In contrast to the diversity of episomal ESBL/AmpC types, isolates from human and animals mainly shared identical sequence types (STs), suggesting transmission or parallel micro-evolution. In conclusion, the opinion that animal ESBL-producing E. coli is a major source of human infections is oversimplified, and neglects a highly complex scenario

    The impact of the climate change on discharge of Suir River Catchment (Ireland) under different climate scenarios

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    International audienceThe impact of climate change on local discharge variability is investigated in the Suir River Catchment which is located in the south-east of Ireland. In this paper, the Rossby Centre Regional Atmospheric Model (RCA) is driven by different global climate data sets. For the past climate (1961?2000), the model is driven by ECMWF reanalysis (ERA-40) data as well as by the output of the general circulation models (GCM's) ECHAM4 and ECHAM5. For the future simulation (2021?2060), the model is driven by two GCM scenarios: ECHAM4_B2 and ECHAM5_A2. To investigate the influence of changed future climate on local discharge, the precipitation of the model output is used as input for the HBV hydrological model. The calibration and validation results of our ERA-40 driven present day simulation shows that the HBV model can reproduce the discharge fairly well, except the extreme discharge is systematically underestimated by about 15?20%. Altogether the application of a high resolution regional climate model in connection with a conceptual hydrological model is capable of capturing the local variability of river discharge for present-day climate using boundary values assimilated with observations such as ERA-40 data. However, using GCM data to drive RCA and HBV suggests, that there is still large uncertainty connected with the GCM formulation: For present day climate the validation of the ECHAM4 and ECHAM5 driven simulations indicates stronger discharge compared to the observations due to overprediction of precipitation, especially for the ECHAM5 driven simulation in the summer season. Whereas according to the ECHAM4_B2 scenario the discharge generally increases ? most pronounced in the wet winter time, there are only slight increases in winter and considerable decreases in summer according to the ECHAM5_A2 scenario. This also leads to a different behaviour in the evolution of return levels of extreme discharge events: Strong increases according to the ECHAM4_B2 scenario and slight decreases according to the ECHAM5_A2 scenario

    Memorandum on a new financial architecture and new regulations

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    The financial crisis is global and is deeply rooted in a decade-long misuse of the financial market for rent-seeking. The financial industry has largely abandoned its role as a service industry, supposedly charging reasonable fees for the services of spreading risk and allocating capital and credit. Instead it provides a market for corporate control –mergers and acquisitions– and a casino for betting on or hedging practically any kind of risk –the derivatives market–.Publisher's Versio

    Об анатомическом строении членистостебельного растения Annulina Neuburgiana Radczenko

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    The purpose was to compare two approaches for the acquisition and analysis of dynamic-contrast-enhanced MRI data with respect to differences in the modelling of the arterial input-function (AIF), the dependency of the model parameters on physiological parameters and their numerical stability. Eight hundred tissue concentration curves were simulated for different combinations of perfusion, permeability, interstitial volume and plasma volume based on two measured AIFs and analysed according to the two commonly used approaches. The transfer constants (Approach 1) K (trans) and (Approach 2) k (ep) were correlated with all tissue parameters. K (trans) showed a stronger dependency on perfusion, and k (ep) on permeability. The volume parameters (Approach 1) v (e) and (Approach 2) A were mainly influenced by the interstitial and plasma volume. Both approaches allow only rough characterisation of tissue microcirculation and microvasculature. Approach 2 seems to be somewhat more robust than 1, mainly due to the different methods of CA administration

    Green bonds, transition to a low-carbon economy, and intertemporal welfare allocation: Evidence from an extended DICE model

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    Short-term reductions in social welfare, expected to be caused by a currently imposed carbon tax, are among the obstacles to a rapid transition to a low-carbon economy. Using an extended DICE model, we studied the potential of green bonds to both accelerate this transition and smoothen welfare losses and gains in a socially optimal way. We showed that green bonds can indeed accelerate the transition to a low-carbon economy and that lower interest rates on bonds speed up this acceleration. Moreover, bonds can reduce short-term welfare losses; however, to eliminate welfare losses, additional compensation mechanisms are needed. For example, bonds at a 3% interest rate can decrease the peak atmospheric carbon concentrations by about 20% and shorten the initial time, during which society is worse off from 75 to 45 years. Retaining at least the same consumption level as in the no-mitigation scenario, without using bonds, is possible only through a decrease in abatement efforts. Green bonds of sufficiently low interest rates allow improving intertemporal welfare as well as achieving a more pronounced climate change mitigation with respect to both mitigation and no-mitigation scenarios without bonds

    Better writing in scientific publications builds reader confidence and understanding

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    Scientific publications are the building blocks of discovery and collaboration, but their impact is limited by the style in which they are traditionally written. Recently, many authors have called for a switch to an engaging, accessible writing style. Here, we experimentally test how readers respond to such a style. We hypothesized that scientific abstracts written in a more accessible style would improve readers’ reported readability and confidence as well as their understanding, assessed using multiple-choice questions on the content. We created a series of scientific abstracts, corresponding to real publications on three scientific topics at four levels of difficulty – varying from the difficult, traditional style to an engaging, accessible style. We gave these abstracts to a team of readers consisting of 170 third-year undergraduate students. Then, we posed questions to measure the readers’ readability, confidence, and understanding with the content. The scientific abstracts written in a more accessible style resulted in higher readability, understanding, and confidence. These findings demonstrate that rethinking the way we communicate our science may empower a more collaborative and diverse industry.Benjamin S. Freeling, Zoë A. Doubleday, Matthew J. Dry, Carolyn Semmler and Sean D. Connel

    Rapid translocation of nanoparticles from the lung airspaces to the body

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    Nano-size particles show promise for pulmonary drug delivery, yet their behavior after deposition in the lung remains poorly understood. In this study, a series of near-infrared (NIR) fluorescent nanoparticles were systematically varied in chemical composition, shape, size and surface charge, and their biodistribution and elimination were quantified in rat models after lung instillation. We demonstrate that nanoparticles with hydrodynamic diameter (HD) less than ≈34 nm and a noncationic surface charge translocate rapidly from the lung to mediastinal lymph nodes. Nanoparticles of HD < 6 nm can traffic rapidly from the lungs to lymph nodes and the bloodstream, and then be subsequently cleared by the kidneys. We discuss the importance of these findings for drug delivery, air pollution and carcinogenesis
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