332 research outputs found
Near-linear dynamics in KdV with periodic boundary conditions
Near linear evolution in Korteweg de Vries (KdV) equation with periodic
boundary conditions is established under the assumption of high frequency
initial data. This result is obtained by the method of normal form reduction
Die VWL in Deutschland und den USA: eine ländervergleichende Analyse
Die Studie erfasst in Deutschland 569 (Vollerhebung) und in den USA 570 (Stichprobe) VWL-Universitätsprofessor_innen an 102 Standorten. Der Frauenanteil ist in Deutschland (13,36%) und in den USA (12,81%) gering. In beiden Ländern nimmt die mikroökonomisch orientierte Forschung eine dominante Stellung ein. Über 90 % der Professor_innen folgen dem ökonomischen Mainstream. Abweichende, heterodoxe Sichtweisen sind v.a. an kleinen Universitäten vertreten. Die Trennung zwischen Mainstream und Heterodoxie ist in den USA weiter fortgeschritten. Wesentliche inhaltliche und methodische Veränderungen innerhalb des Mainstreams betreffen v.a. die Verhaltensökonomie und Experimentelle Ökonomie. Die jüngere Generation in Deutschland ist noch stärker an der Mikroökonomie und am ökonomischen Mainstream orientiert; ordoliberale Ideen verlieren an Bedeutung. Die außerakademische Vernetzung erfolgt in Deutschland über Wirtschaftsforschungsinstitute. Zudem engagieren sich viele deutsche Ökonom_innen in ordo- bzw. neoliberalen Think Tanks. In den USA existiert eine klare Blockbildung aus demokratisch vs. republikanisch orientierten Ökonom_innen auf medial-politischer Ebene, wobei der demokratische Block deutlich größer ist. Demgegenüber sind konservative und libertäre Think Tanks größer und umfangreicher vernetzt. Deutsche wirtschaftswissenschaftliche Beratungsgremien weisen auf Personenebene eine ausgeprägte ordoliberale Schlagseite auf
Facephenes and rainbows: Causal evidence for functional and anatomical specificity of face and color processing in the human brain
Neuroscientists have long debated whether some regions of the human brain are exclusively engaged in a single specific mental process. Consistent with this view, fMRI has revealed cortical regions that respond selectively to certain stimulus classes such as faces. However, results from multivoxel pattern analyses (MVPA) challenge this view by demonstrating that category-selective regions often contain information about “nonpreferred” stimulus dimensions. But is this nonpreferred information causally relevant to behavior? Here we report a rare opportunity to test this question in a neurosurgical patient implanted for clinical reasons with strips of electrodes along his fusiform gyri. Broadband gamma electrocorticographic responses in multiple adjacent electrodes showed strong selectivity for faces in a region corresponding to the fusiform face area (FFA), and preferential responses to color in a nearby site, replicating earlier reports. To test the causal role of these regions in the perception of nonpreferred dimensions, we then electrically stimulated individual sites while the patient viewed various objects. When stimulated in the FFA, the patient reported seeing an illusory face (or “facephene”), independent of the object viewed. Similarly, stimulation of color-preferring sites produced illusory “rainbows.” Crucially, the patient reported no change in the object viewed, apart from the facephenes and rainbows apparently superimposed on them. The functional and anatomical specificity of these effects indicate that some cortical regions are exclusively causally engaged in a single specific mental process, and prompt caution about the widespread assumption that any information scientists can decode from the brain is causally relevant to behavior.National Institutes of Health (U.S.) (Grant DP1HD091947
Netzwerke, Paradigmen, Attitüden: Der deutsche Sonderweg im Fokus; Paradigmatische Ausrichtung und politische Orientierung von deutschen und US-amerikanischen Ökonom_innen im Vergleich
Inhalt dieser Studie ist eine vergleichende Bestandsaufnahme des aktuellen Profils sowie zukünftiger Entwicklungstendenzen der Volkswirtschaftslehre in Deutschland und den USA vor dem Hintergrund der Frage nach einem deutschen Sonderweg in der Ökonomie. Mittels einer indikatorbasierten Typologisierung wurden die derzeit in den beiden Ländern wirkenden Universitätsprofessor_innen im Hinblick auf ihre thematischen und inhaltlichen Forschungsschwerpunkte sowie ihre akademischen und außeruniversitären Mitgliedschaften in wirtschaftspolitischen Institutionen und Think-Tanks untersucht. Während das Forschungsprofil in beiden Ländern weitgehend homogenisiert ist, wurden v. a. auf der Ebene des wirtschaftspolitischen Wirkungsspektrums länderspezifische Unterschiede identifiziert, die auf einen deutschen Sonderweg in der Wirtschaftspolitik hinweisen.he central subject of this study is a comparative analysis of the current state as well as development trends in German and US economics, to check the thesis of a German special path.Therefore we conducted an empirical analysis of full professors of economics in the countries chosen. The main focus of our analysis is on their publications in economic journals (research profile) as well as on their scientific and political connections (policy making). The data collection was realized through a multilevel survey, which consists of qualitative and quantitative variables. A main result of the study is that while the research profile (e. g. the paradigmatic orientation) of economists in the two countries is fairly similar, differences potentially indicating a special path of German economics can be found on the level of politico-economic networks in economic policy advice
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Inhibition of acetyl-CoA carboxylase suppresses fatty acid synthesis and tumor growth of non-small-cell lung cancer in preclinical models.
Continuous de novo fatty acid synthesis is a common feature of cancer that is required to meet the biosynthetic demands of a growing tumor. This process is controlled by the rate-limiting enzyme acetyl-CoA carboxylase (ACC), an attractive but traditionally intractable drug target. Here we provide genetic and pharmacological evidence that in preclinical models ACC is required to maintain the de novo fatty acid synthesis needed for growth and viability of non-small-cell lung cancer (NSCLC) cells. We describe the ability of ND-646-an allosteric inhibitor of the ACC enzymes ACC1 and ACC2 that prevents ACC subunit dimerization-to suppress fatty acid synthesis in vitro and in vivo. Chronic ND-646 treatment of xenograft and genetically engineered mouse models of NSCLC inhibited tumor growth. When administered as a single agent or in combination with the standard-of-care drug carboplatin, ND-646 markedly suppressed lung tumor growth in the Kras;Trp53-/- (also known as KRAS p53) and Kras;Stk11-/- (also known as KRAS Lkb1) mouse models of NSCLC. These findings demonstrate that ACC mediates a metabolic liability of NSCLC and that ACC inhibition by ND-646 is detrimental to NSCLC growth, supporting further examination of the use of ACC inhibitors in oncology
New Perspectives on Institutionalist Pattern Modeling: Systemism, Complexity, and Agent-Based Modeling
This paper focuses on the complementarity between original institutional economics, Mario Bunge’s framework of systemism, and the formal tools developed by complexity economists, especially in the context of agent-based modeling. Thereby, we assert that original institutional economics might profit from exploiting this complementarity
Impact Factor: outdated artefact or stepping-stone to journal certification?
A review of Garfield's journal impact factor and its specific implementation
as the Thomson Reuters Impact Factor reveals several weaknesses in this
commonly-used indicator of journal standing. Key limitations include the
mismatch between citing and cited documents, the deceptive display of three
decimals that belies the real precision, and the absence of confidence
intervals. These are minor issues that are easily amended and should be
corrected, but more substantive improvements are needed. There are indications
that the scientific community seeks and needs better certification of journal
procedures to improve the quality of published science. Comprehensive
certification of editorial and review procedures could help ensure adequate
procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table
Invariance and variability in interaction error-related potentials and their consequences for classification
© 2017 IOP Publishing Ltd. Objective. This paper discusses the invariance and variability in interaction error-related potentials (ErrPs), where a special focus is laid upon the factors of (1) the human mental processing required to assess interface actions (2) time (3) subjects. Approach. Three different experiments were designed as to vary primarily with respect to the mental processes that are necessary to assess whether an interface error has occurred or not. The three experiments were carried out with 11 subjects in a repeated-measures experimental design. To study the effect of time, a subset of the recruited subjects additionally performed the same experiments on different days. Main results. The ErrP variability across the different experiments for the same subjects was found largely attributable to the different mental processing required to assess interface actions. Nonetheless, we found that interaction ErrPs are empirically invariant over time (for the same subject and same interface) and to a lesser extent across subjects (for the same interface). Significance. The obtained results may be used to explain across-study variability of ErrPs, as well as to define guidelines for approaches to the ErrP classifier transferability problem
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Modelling climate and societal resilience in the Eastern Mediterranean in the last Millennium
This article analyses high-quality hydroclimate proxy records and spatial reconstructions from the Central and Eastern Mediterranean and compares them with two Earth System Model simulations (CCSM4, MPI-ESM-P) for the Crusader period in the Levant (1095–1290 CE), the Mamluk regime in Transjordan (1260–1516 CE) and the Ottoman crisis and Celâlî Rebellion(1580–1610 CE). During the three time intervals, environmental and climatic stress tested the resilience of complex societies.We find that the multidecadal precipitation and drought variations in the Central and Eastern Mediterranean cannot be explained by external forcings (solar variations, tropical volcanism); rather they were driven by internal climate dynamics. Our research emphasises the challenges, opportunities and limitations of linking proxy records, palaeoreconstructions and model simulations to better understand how climate can affect human history
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