1,425 research outputs found
Discrete Morse theory for the collapsibility of supremum sections
The Dushnik-Miller dimension of a poset is the minimal number of
linear extensions of such that is the
intersection of . Supremum sections are simplicial
complexes introduced by Scarf and are linked to the Dushnik-Miller as follows:
the inclusion poset of a simplicial complex is of Dushnik-Miller dimension at
most if and only if it is included in a supremum section coming from a
representation of dimension . Collapsibility is a topoligical property of
simplicial complexes which has been introduced by Whitehead and which resembles
to shellability. While Ossona de Mendez proved in that a particular type of
supremum sections are shellable, we show in this article that supremum sections
are in general collapsible thanks to the discrete Morse theory developped by
Forman
Industrial Ecology's Hidden Philosophy of Nature. Fundamental Underpinning to Use Nature as Model
In its scientific sense, industrial ecology represents an emerging transdisciplinary field of studying industrial systems and their fundamental linkage with natural ecosystems. As a short form, industrial ecology is called the "science of sustainability". At the bottom of industrial ecology there is a refreshingly different perspective of understanding nature as model in comparison with other scientific disciplines and concepts of understanding nature e.g. in terms of "sack of resources", "biophysical limit", "something outside", "surrounding", or just "environment" as opposed to industrial systems. The keynote of industrial ecology's specific perspective of understanding nature is to balance the development of industrial systems with the constraints of natural eco-systems, analogous to an "industrial symbiosis". The goal is to contribute for laying a fundamental underpinning for industrial ecology in its scientific sense, in this case especially for its use of nature as model. Therefore an impressive battery of philosophical arguments is provided bringing to bear against the sort of probably raised fallacies and facile or hasty proclaimed critics by sceptics, hard-liners, and mainstream-scientists who often overlook industrial ecology's stimulating role towards sustainability
Knowledge Cartography for Controversies: The Iraq Debate
In analysing controversies and debates—which would include reviewing a literature in order to plan research, or assessing intelligence to formulate policy—there is no one worldview which can be mapped, for instance as a single, coherent concept map. The cartographic challenge is to show which facts are agreed and contested, and the different kinds of narrative links that use facts as evidence to define the nature of the problem, what to do about it, and why. We will use the debate around the invasion of Iraq to demonstrate the methodology of using a knowledge mapping tool to extract key ideas from source materials, in order to classify and connect them within and across a set of perspectives of interest to the analyst. We reflect on the value that this approach adds, and how it relates to other argument mapping approaches
Umweltberichterstattung von Unternehmen im Internet. Der aktuelle Stand für Deutschland
Von den Umweltberichten deutscher Unternehmen werden bisher erst unter 3% im Internet veröffentlicht. Die Tendenz ist steigend. Hier werden die im Internet verfügbaren Umweltberichte ausgewertet und Gründe für die Nutzung des Internet für die Umweltberichterstattung vorgetragen. Der Beitrag ist in fünf Abschnitte gegliedert: Zur thematischen Einführung werden betriebliche Umweltberichte durch eine Morphologie charakterisiert (Abschnitt 2). Es schließen sich die IKT-spezifischen Herausforderungen an umweltberichterstattende Unternehmen als Ansatzpunkte für Umweltberichte im Internet an (Abschnitt 3). Damit ist die Basis für eine Systematisierung der internetbasierten Unterstützungspotenziale zur Umweltberichterstattung gelegt (Abschnitt 4). Der Systematik folgt eine detaillierte Bestandsaufnahme der Umweltberichte deutscher Unternehmen im Internet in fünffacher Hinsicht (Abschnitt 5): Die zugrunde gelegte Untersuchungsmethodik zur Bestandsaufnahme wird erläutert (Abschnitt 5.1). Die ergänzend herangezogenen empirischen Studien zu Umweltberichten im Internet werden ausgewertet (Abschnitt 5.2). Die Ergebnisse bzgl. Inhalt und Darstellung von Umweltberichten im Internet werden ausführlicher beschrieben (Abschnitt 5.3) und durch Erklärungsansätze interpretiert (Abschnitt 5.4). Abschließend werden auf der Grundlage der konzeptionell erschließbaren Unterstützungspotenziale einerseits und der empirischen Studien andererseits zentrale Tendenzen zur zukünftigen Entwicklung von Umweltberichten im Internet vorgetragen (Abschnitt 5.5)
Modelling spatial distributions of alpine vegetation : a graph theory approach to delineate ecologically-consistent species assemblages
This work was partly funded by the French Ministry of Ecology, Sustainable Development and Energy in support of the development of the CARHab project (2011-2015) on mapping the terrestrial habitats of France. In addition, this work benefited from a synergy with the Divgrass project (Plant Functional Diversity of Permanent Grasslands) (CESAB/FRB funded, France).Safeguarding biodiversity has been one of the most important issues on the environmental and forest policies agenda since the 1990's. The problem remains in terms of decisions and knowledge on where to set appropriate conservation targets. Hence, we need detailed and reliable information about habitat structure and composition and methods for estimating this information over the whole spatial domain. In answer to this target, in France, the Ministry of Ecology launched an ambitious project to map the terrestrial vegetation at a scale of 1:25 000 known as CarHab. This project initiated in 2011, will be used as a strategic spatial planning tool in answer to key issues in relation to biodiversity, conservation, green infrastructures and to report on the conservation status of habitats and species of community interest. We use species-distribution models (SDMs) to identify areas that are ecologically suitable for the presence of species based on specific habitat characteristics. Available techniques using graph theory enable identification of groups of species (assemblages) based on ecological affinities. Species co-occurrences (present within the same assessment plot), revealing a shared ecological niche, are analysed using algorithms derived from graph theory in order to define different nodes of species affinities. Thus, the resulting assemblages are based on ecological similarities. Hence, these assemblages are used to develop models of the potential distribution of alpine vegetation communities. The BIOMOD platform is used to facilitate the simultaneous implementation of different modelling approaches that can be compared in order to choose the most suitable and accurate for each species assemblage obtained from graph theory. Using the different relevant spatially explicit results provides a more comprehensive vision of the communities' spatial distributions.PostprintPeer reviewe
Non-dipping nocturnal blood pressure and psychosis parameters in Parkinson disease
Conclusion: These results suggest that, among PD patients, a non-dipping circadian rhythm is associated with more severe symptoms of psychosis than is a dipping circadian rhythm. This association warrants further investigation
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