130 research outputs found
Switching on electricity demand response: Evidence for German households
Empirical evidence on the response of German households to electricity price
changes is sparse. Using panel data originating from Germany’s Residential Energy
Consumption Survey (GRECS), we fill this void by employing an instrumental variable
approach to cope with the endogeneity of the consumers’ tariff choice. By additionally
exploiting our information on the households’ knowledge about power prices, we also
employ an Endogenous Switching Regression Model to estimate price elasticities for
two groups of households, finding that only those households that are informed about
prices are sensitive to price changes, whereas the electricity demand of uninformed
households is entirely price-inelastic
Bodenschutz in der Landwirtschaft: Einfache Bodenbeurteilung für Praxis, Beratung und Forschung
Nach einer kurzen Einführung zur aktuellen Gefährdung der Böden in den durch eine industrielle Landwirtschaft geprägten Ländern folgt ein methodischer Teil. In diesem wird nach einer kurzen bodenkundlichen Grundlageneinführung erklärt, wie verschiedene Merkmale des Bodens mit jeweils sowohl einfachsten Schätzmethoden als auch auswertbaren Boniturmethoden zur Beurteilung des ökologischen Zustands herangezogen und ausgewertet werden können. Die Spatendiagnose spielt dabei eine besondere Rolle. Die Vorgehensweise wird genau erklärt und durch Beispiele veranschaulicht. Für die Einordnung der Ergebnisse werden Interpretationshilfen gegeben. Der Interessierte findet Empfehlungen zur weiterführenden Literatur. In einem dritten Teil finden sich Forschungsbeispiele und Erfahrensberichte aus der Beratung und der Praxis
The price response of residential electricity demand in Germany: A dynamic approach
Due to growing concerns about climate change, policy-makers from all
around the world establish measures, such as carbon taxes, to lower electricity demand
and energy consumption in general. Drawing on household panel data from
the German Residential Energy Consumption Survey (GRECS) that span over nine
years (2006-2014) and employing the sum of regulated price components as an instrument
for the likely endogenous electricity price, we gauge the response of residential
electricity demand to price increases on the basis of the dynamic Blundell-Bond estimator
to account for potential simultaneity and endogeneity problems, as well as
the Nickell bias. Estimating short- and long-run price elasticities of -0.44 and -0.66,
respectively, our results indicate that price measures may be effective in dampening
residential electricity consumption, particularly in the long run. Yet, we also find that
responses to price changes are very heterogeneous across household groups
Climate policy in times of the corona pandemic: Empirical evidence from Germany
Given the dramatic changes triggered by the Corona pandemic, the question arises whether it
has displaced people’s concerns about climate change and whether Corona-related financial losses among
affected households can influence their assessment of climate change. Based on a survey among more
than 6,000 German household heads conducted in the period spanning from May 18 to June 14, 2020, this
paper provides empirical evidence on the impact of the pandemic on perceptions of climate change and
climate policy, as well as the extent to which respondents are affected in terms of health and finances.
Although the majority of almost 77% of the respondents is concerned about their own health and that of
their families, according to our descriptive results, climate change appears to remain an important issue:
only six percent of the respondents feel that climate change has become less important since the beginning
of 2020, while about 70% of the respondents see no change in the importance of the issue. Yet, employing
discrete-choice models, our estimation results indicate that households that suffered from Coronarelated
financial losses consider climate change to be less important than households that remained unaffected
in this respect. In accord with Engler et al. (2020), we thus conclude that lowering individual financial
losses is not only relevant from a social perspective, but it is also critical for the acceptance of
climate policy measures
SPIKE: Secure and Private Investigation of the Kidney Exchange problem
Background: The kidney exchange problem (KEP) addresses the matching of
patients in need for a replacement organ with compatible living donors. Ideally
many medical institutions should participate in a matching program to increase
the chance for successful matches. However, to fulfill legal requirements
current systems use complicated policy-based data protection mechanisms that
effectively exclude smaller medical facilities to participate. Employing secure
multi-party computation (MPC) techniques provides a technical way to satisfy
data protection requirements for highly sensitive personal health information
while simultaneously reducing the regulatory burdens.
Results: We have designed, implemented, and benchmarked SPIKE, a secure
MPC-based privacy-preserving KEP which computes a solution by finding matching
donor-recipient pairs in a graph structure. SPIKE matches 40 pairs in cycles of
length 2 in less than 4 minutes and outperforms the previous state-of-the-art
protocol by a factor of 400x in runtime while providing medically more robust
solutions.
Conclusions: We show how to solve the KEP in a robust and privacy-preserving
manner achieving practical performance. The usage of MPC techniques fulfills
many data protection requirements on a technical level, allowing smaller health
care providers to directly participate in a kidney exchange with reduced legal
processes.Comment: 26 pages, 6 figure
Klimapolitik während der Corona-Pandemie: Ergebnisse einer Haushaltserhebung
Dieser Beitrag liefert erste umfassende empirische Evidenz darüber, welchen Einfluss die Pandemie auf die Wahrnehmung von Klimawandel und Klimapolitik hat, inwieweit die Befragten gesundheitlich und finanziell betroffen sind sowie zur Einschätzung von klimapolitischen Aspekten bei wirtschaftspolitischen Maßnahmen, die zur Überwindung der Folgen der Corona-Krise ergriffen werden. Die wesentlichen Ergebnisse lauten wie folgt: Obwohl bislang nur wenige der Befragten direkt vom Coronavirus betroffen waren, macht sich eine Mehrheit Sorgen um die Auswirkungen der Pandemie. Knapp 77 % der Befragten sorgen sich zumindest „mäßig“ um die eigene Gesundheit und die der Familie. Gut 86 % sind mindestens „mäßig besorgt“ über die Folgen für den gesellschaftlichen Zusammenhalt. Dennoch bleibt auch der Klimawandel ein wichtiges Thema: Nur sechs Prozent der Befragten finden, dass der Klimawandel seit Jahresbeginn an Bedeutung verloren habe. 70 % sehen keine Veränderung in der Wichtigkeit des Themas. 23 % sind sogar der Meinung, der Klimawandel habe in den vergangenen Monaten an Bedeutung gewonnen. Gleichwohl weisen erste Korrelations- und Regressionsanalysen darauf hin, dass Haushalte mit Corona-bedingten finanziellen Einbußen den Klimawandel als weniger bedeutsam einschätzen als nicht betroffene Haushalte
Time fluctuations in a population model of adaptive dynamics
International audienceWe study the dynamics of phenotypically structured populations in environments with fluctuations. In particular, using novel arguments from the theories of Hamilton-Jacobi equations with constraints and homogenization, we obtain results about the evolution of populations in environments with time oscillations, the development of concentrations in the form of Dirac masses, the location of the dominant traits and their evolution in time. Such questions have already been studied in time homogeneous environments. More precisely we consider the dynamics of a phenotypically structured population in a changing environment under mutations and competition for a single resource. The mathematical model is a non-local parabolic equation with a periodic in time reaction term. We study the asymptotic behavior of the solutions in the limit of small diffusion and fast reaction. Under concavity assumptions on the reaction term, we prove that the solution converges to a Dirac mass whose evolution in time is driven by a Hamilton-Jacobi equation with constraint and an effective growth/death rate which is derived as a homogenization limit. We also prove that, after long-time, the population concentrates on a trait where the maximum of an effective growth rate is attained. Finally we provide an example showing that the time oscillations may lead to a strict increase of the asymptotic population size
Genetic noise control via protein oligomerization
Gene expression in a cell entails random reaction events occurring over
disparate time scales. Thus, molecular noise that often results in phenotypic
and population-dynamic consequences sets a fundamental limit to biochemical
signaling. While there have been numerous studies correlating the architecture
of cellular reaction networks with noise tolerance, only a limited effort has
been made to understand the dynamic role of protein-protein interactions. Here
we have developed a fully stochastic model for the positive feedback control of
a single gene, as well as a pair of genes (toggle switch), integrating
quantitative results from previous in vivo and in vitro studies. We find that
the overall noise-level is reduced and the frequency content of the noise is
dramatically shifted to the physiologically irrelevant high-frequency regime in
the presence of protein dimerization. This is independent of the choice of
monomer or dimer as transcription factor and persists throughout the multiple
model topologies considered. For the toggle switch, we additionally find that
the presence of a protein dimer, either homodimer or heterodimer, may
significantly reduce its random switching rate. Hence, the dimer promotes the
robust function of bistable switches by preventing the uninduced (induced)
state from randomly being induced (uninduced). The specific binding between
regulatory proteins provides a buffer that may prevent the propagation of
fluctuations in genetic activity. The capacity of the buffer is a non-monotonic
function of association-dissociation rates. Since the protein oligomerization
per se does not require extra protein components to be expressed, it provides a
basis for the rapid control of intrinsic or extrinsic noise
Structural basis for the specificity of bipartite nuclear localization sequence binding by importin-α
Importin-alpha is the nuclear import receptor that recognizes cargo proteins carrying conventional basic monopartite and bipartite nuclear localization sequences (NLSs) and facilitates their transport into the nucleus. Bipartite NLSs contain two clusters of basic residues, connected by linkers of variable lengths. To determine the structural basis of the recognition of diverse bipartite NLSs by mammalian importin-alpha, we co-crystallized a non-autoinhibited mouse receptor protein with peptides corresponding to the NLSs from human retinoblastoma protein and Xenopus laevis phosphoprotein N1N2, containing diverse sequences and lengths of the linker. We show that the basic clusters interact analogously in both NLSs, but the linker sequences adopt different conformations, whereas both make specific contacts with the receptor. The available data allow us to draw general conclusions about the specificity of NLS binding by importin-alpha and facilitate an improved definition of the consensus sequence of a conventional basic/bipartite NLS (KRX10-12KRRK) that can be used to identify novel nuclear proteins
Transcriptional Activity and Nuclear Localization of Cabut, the Drosophila Ortholog of Vertebrate TGF-β-Inducible Early-Response Gene (TIEG) Proteins
BackgroundCabut (Cbt) is a C2H2-class zinc finger transcription factor involved in embryonic dorsal closure, epithelial regeneration and other developmental processes in Drosophila melanogaster. Cbt orthologs have been identified in other Drosophila species and insects as well as in vertebrates. Indeed, Cbt is the Drosophila ortholog of the group of vertebrate proteins encoded by the TGF-ß-inducible early-response genes (TIEGs), which belong to Sp1-like/Krüppel-like family of transcription factors. Several functional domains involved in transcriptional control and subcellular localization have been identified in the vertebrate TIEGs. However, little is known of whether these domains and functions are also conserved in the Cbt protein.Methodology/Principal FindingsTo determine the transcriptional regulatory activity of the Drosophila Cbt protein, we performed Gal4-based luciferase assays in S2 cells and showed that Cbt is a transcriptional repressor and able to regulate its own expression. Truncated forms of Cbt were then generated to identify its functional domains. This analysis revealed a sequence similar to the mSin3A-interacting repressor domain found in vertebrate TIEGs, although located in a different part of the Cbt protein. Using β-Galactosidase and eGFP fusion proteins, we also showed that Cbt contains the bipartite nuclear localization signal (NLS) previously identified in TIEG proteins, although it is non-functional in insect cells. Instead, a monopartite NLS, located at the amino terminus of the protein and conserved across insects, is functional in Drosophila S2 and Spodoptera exigua Sec301 cells. Last but not least, genetic interaction and immunohistochemical assays suggested that Cbt nuclear import is mediated by Importin-α2.Conclusions/SignificanceOur results constitute the first characterization of the molecular mechanisms of Cbt-mediated transcriptional control as well as of Cbt nuclear import, and demonstrate the existence of similarities and differences in both aspects of Cbt function between the insect and the vertebrate TIEG proteins
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