54 research outputs found

    Monopole, Liberalisierung, Energiewende : Strommarktdesign zwischen Wandel und Konstanz

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    Nach einer langen Phase der StabilitĂ€t ist die Stromwirtschaft in den vergangenen 15 Jahren stark in Bewegung geraten. Mit der Liberalisierung stand zunĂ€chst der Wechsel von Gebietsmonopolen hin zu wettbewerblich organisierten Erzeuger- und VerbrauchermĂ€rkten an. Derzeit findet ein ganz Ă€hnlicher Umbruch statt, der vom Übergang von konventioneller hin zu erneuerbarer Stromerzeugung gekennzeichnet ist. Aber sind die Paradigmen der einzelnen Phasen miteinander vereinbar und hat jede fĂŒr sich noch immer ihre Daseinsberechtigung, oder ist hier eine Modifizierung notwendig? Das Strommarktdesign der Zukunft kann nicht auf einem leeren Blatt entworfen, sondern es mĂŒssen bestehende Strukturen berĂŒcksichtigt werden. Gleichzeitig ist die Frage zu beantworten, ob die Wahl zwischen regulatorischen oder marktbasierten AnsĂ€tzen sich auch anhand der mit ihnen möglichen PrĂ€zision der Steuerung unterscheidet

    Modelling the effects of variable tariffs on domestic electric load profiles by use of occupant behavior submodels

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    Emerging infrastructure for residential meter communication and data processing carries the potential to control household electrical demand within local power system constraints. Deferral of load control can be incentivised through electricity tariff price structure which can in turn reshape a daily load profile. This paper presents a stochastic bottom-up model designed to predict the change in domestic electricity profile invoked by consumer reaction to electricity unit price, with submodels comprising user behaviour, price response and dependency between behaviour and electric demand. The developed models are used to analyse the demand side management potential of the most relevant energy consuming activities through a simulated German household demonstrating that in the given scenario 8% of the annual electricity demand is shifted, leading to a 35e annual saving. However, a 7% higher than average peak load results from the structure of the tariff signal modelled herein. A discussion on selected aspects for tariff design for categories of typical household appliances is included

    Monopole, Liberalisierung, Energiewende : (Dis-)KontinuitÀten im Strommarktdesign

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    Nach einer langen Phase der StabilitĂ€t ist die Stromwirtschaft in den vergangenen 15 Jahren stark in Bewegung geraten. ZunĂ€chst stand der Wechsel von staatlich ĂŒberwachten und regulierten Gebietsmonopolen hin zu liberalisierten Erzeuger- und VerbrauchermĂ€rkten an. Im Moment befinden wir uns in einem Ă€hnlichen Umbruch, weg von konventioneller hin zu erneuerbarer Energieerzeugung. Im vorliegenden Beitrag soll der Leitfrage nachgegangen werden, ob die Paradigmen der einzelnen Phasen miteinander vereinbar sind, welche noch immer ihre Daseinsberechtigung haben und welche modifiziert werden sollten

    The rate of telomere loss is related to maximum lifespan in birds

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    Telomeres are highly conserved regions of DNA that protect the ends of linear chromosomes. The loss of telomeres can signal an irreversible change to a cell's state, including cellular senescence. Senescent cells no longer divide and can damage nearby healthy cells, thus potentially placing them at the crossroads of cancer and ageing. While the epidemiology, cellular and molecular biology of telomeres are well studied, a newer field exploring telomere biology in the context of ecology and evolution is just emerging. With work to date focusing on how telomere shortening relates to individual mortality, less is known about how telomeres relate to ageing rates across species. Here, we investigated telomere length in cross-sectional samples from 19 bird species to determine how rates of telomere loss relate to interspecific variation in maximum lifespan. We found that bird species with longer lifespans lose fewer telomeric repeats each year compared with species with shorter lifespans. In addition, phylogenetic analysis revealed that the rate of telomere loss is evolutionarily conserved within bird families. This suggests that the physiological causes of telomere shortening, or the ability to maintain telomeres, are features that may be responsible for, or co-evolved with, different lifespans observed across species.This article is part of the theme issue 'Understanding diversity in telomere dynamics'

    Quantitative and Molecular Genetic Analyses of Mutations Increasing Drosophila Life Span

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    Understanding the genetic and environmental factors that affect variation in life span and senescence is of major interest for human health and evolutionary biology. Multiple mechanisms affect longevity, many of which are conserved across species, but the genetic networks underlying each mechanism and cross-talk between networks are unknown. We report the results of a screen for mutations affecting Drosophila life span. One third of the 1,332 homozygous P–element insertion lines assessed had quantitative effects on life span; mutations reducing life span were twice as common as mutations increasing life span. We confirmed 58 mutations with increased longevity, only one of which is in a gene previously associated with life span. The effects of the mutations increasing life span were highly sex-specific, with a trend towards opposite effects in males and females. Mutations in the same gene were associated with both increased and decreased life span, depending on the location and orientation of the P–element insertion, and genetic background. We observed substantial—and sex-specific—epistasis among a sample of ten mutations with increased life span. All mutations increasing life span had at least one deleterious pleiotropic effect on stress resistance or general health, with different patterns of pleiotropy for males and females. Whole-genome transcript profiles of seven of the mutant lines and the wild type revealed 4,488 differentially expressed transcripts, 553 of which were common to four or more of the mutant lines, which include genes previously associated with life span and novel genes implicated by this study. Therefore longevity has a large mutational target size; genes affecting life span have variable allelic effects; alleles affecting life span exhibit antagonistic pleiotropy and form epistatic networks; and sex-specific mutational effects are ubiquitous. Comparison of transcript profiles of long-lived mutations and the control line reveals a transcriptional signature of increased life span

    Three-Dimensional Optical Analysis of Ferroelectric Domain Walls

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    International audienc

    Health Care Professionals’ Perception of Contraindications for Physical Activity During Cancer Treatment

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    IntroductionSuggested medical contraindications for physical activity (PA) during cancer therapy might have an influence on PA recommendation behavior of Health Care Professionals (HCP). The purpose of the present study was to examine perceptions of physicians and oncology nurses (ON) toward specific medical conditions as contraindications for PA during cancer treatment.Materials and methodsA total of 539 physicians and 386 ON were enrolled in this cross-sectional survey. HCP judged 13 medical conditions as to whether they are contraindications for PA during cancer treatment. Answering format was “no contraindication”/“potentially a contraindication”/“yes, a contraindication.”Resultsχ2 analyses revealed significant differences between general practitioners, specialized physicians, and ON in their perception of 10 medical conditions. Approximately half of the medical conditions were answered cautiously, showing high numbers on the response option potentially (36–72%). Moreover, physicians’ ratings differed significantly depending on their practical experience with particular medical conditions. Those being familiar with a specific medical condition was more permissive to PA during treatment, with effect sizes (Cramer’s V) ranging from 0.13 to 0.27.ConclusionResults indicate high cautiousness among HCP in judging medical conditions and their impact on PA during cancer treatment. However, group comparisons show that familiarity and clinical experience with potential contraindications facilitate a confident handling of safety issues, which at best leads to higher levels of PA recommendations during cancer treatment
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