2,263 research outputs found
Effects of habitat isolation and predation pressure on an arboreal food-web
No full textHabitat isolation is expected to reduce population densities of animals via reduced immigration. However, altered trophic interactions in isolated habitats may modify these effects, especially since the strength of isolation effects is expected to increase with trophic rank. Here, we studied effects of habitat isolation on a food-web module consisting of herbivorous beetles, predatory spiders, spider-preying wasps and arthropod-feeding birds. We compare two systems that were studied in subsequent years: a study on 29 mature apple orchards that varied in the degree of isolation from forest, and a study on 20 groups of newly planted cherry trees that showed similar variation in their degree of habitat isolation. No birds were observed on the young fruit trees. Wasps and spiders showed the expected lower abundances in isolated habitats. On mature trees, birds were present and showed lower abundances in isolated habitats. Wasps were reduced to a similar degree by habitat isolation as on the young trees. Surprisingly, spider densities on the mature trees were higher in isolated than in connected habitat. This contrasting response of spiders to habitat isolation is likely to be due to release from bird predation in isolated mature orchards. In both study systems, beetles showed no significant effect of habitat isolation. Our results confirm that the sensitivity to fragmentation increases with trophic rank, and suggest that trophic interactions should receive more attention in fragmentation studies.Swiss National Science foundation [3100A0-114058
Species richness-environment relationships of European arthropods at two spatial grains: habitats and countries
No full textWe study how species richness of arthropods relates to theories concerning net primary productivity, ambient energy, water-energy dynamics and spatial environmental heterogeneity. We use two datasets of arthropod richness with similar spatial extents (Scandinavia to Mediterranean), but contrasting spatial grain (local habitat and country). Samples of ground-dwelling spiders, beetles, bugs and ants were collected from 32 paired habitats at 16 locations across Europe. Species richness of these taxonomic groups was also determined for 25 European countries based on the Fauna Europaea database. We tested effects of net primary productivity (NPP), annual mean temperature (T), annual rainfall (R) and potential evapotranspiration of the coldest month (PETmin) on species richness and turnover. Spatial environmental heterogeneity within countries was considered by including the ranges of NPP, T, R and PETmin. At the local habitat grain, relationships between species richness and environmental variables differed strongly between taxa and trophic groups. However, species turnover across locations was strongly correlated with differences in T. At the country grain, species richness was significantly correlated with environmental variables from all four theories. In particular, species richness within countries increased strongly with spatial heterogeneity in T. The importance of spatial heterogeneity in T for both species turnover across locations and for species richness within countries suggests that the temperature niche is an important determinant of arthropod diversity. We suggest that, unless climatic heterogeneity is constant across sampling units, coarse-grained studies should always account for environmental heterogeneity as a predictor of arthropod species richness, just as studies with variable area of sampling units routinely consider area
Het creëren van een vastgoedportfolio in de beleveniseconomie; over een mogelijke toekomst van vastgoedmanagement
No full textIn het onderzoek wordt gezocht naar een verband tussen ontwikkelingen in de economie en filosofie en veranderingen in het vakgebied vastgoedmanagement. Het resultaat van dit onderzoek is een model dat verwachtingen beschrijft hoe organisaties in de toekomst in de beleveniseconomie een vastgoedportfolio zullen gaan creëren. Beleveniseconomie is het fenomeen van een verschuiving van aandacht in de economie op drie thema's: de toename van de waardering van de immateriële aspect, de actievere rol van de klant in het creëren van de belevenis en de toename van de individualiteit van de belevenis. De Nederlandse filosoof Arnold Cornelis beschrijft in zijn boek "Logica van het gevoel" eenzelfde soort verschuiving van aandacht. Echter richt hij zich niet op de economie, maar op mens en maatschappij als geheel: een hoger abstractieniveau. Hij beschrijft dat mens en maatschappij in een transitie leven van het sociaal regelsysteem naar communicatieve zelfsturing. In het sociaal regelsysteem, zo beschrijft Cornelis, wordt veel waarde gehecht aan feiten, materiële en wetenschappelijke aspecten van de werkelijkheid. Mensen zoeken naar een vervulling van materiële behoeften en het individu wordt gestuurd door de buitenwereld, de mens wordt gevormd door de cultuur. Het individu neemt een passieve rol aan. Een communicatief zelfsturend individu hecht veel waarde aan persoonlijke waarden, het niet tast-bastbare innerlijke van de mens. Een communicatief zelfsturend individu is in staat haar eigen cultuur te vormen door communicatie op een gelijkwaardige basis. Het volgt niet zwijgzaam alle regels op die de individu van buitenaf krijgt opgelegd, maar gaat in discussie over het "waarom". Op zowel economisch gebied als in de mens en maatschappij is dus sprake van een transformatie. In de oude systemen wordt veel aandacht wordt gehecht aan materiele zaken en feiten, vindt weinig communicatie op een gelijkwaardige basis plaats en de mens en maatschappij worden gevormd door de regels die van buitenaf worden opgelegd. Het nieuwe systeem kenmerkt zich door communicatie op een gelijkwaardige basis met alle partijen, er wordt veel waarde gehecht aan persoonlijke waarden en de mens begint weer haar eigen cultuur te vormen in plaats van andersom. In vastgoedmanagement wordt ook veel waarde gehecht aan feiten en materialistische zaken, zo blijkt uit een intensieve literatuurstudie. Ook blijkt uit die studie dat er weinig aandacht lijkt voor communicatie. Maar enkele case studies, waarin bedrijven zijn onderzocht die vooruitstrevend zijn in de beleveniseconomie, tonen aan dat binnen die bedrijven de manier waarop vastgoedmanagement bedreven wordt overeenkomt met de kenmerken van de beleveniseconomie en het communicatief zelfsturend systeem. Aan de hand van deze nieuwe theoretische en praktische kennis is het "Model voor het creëren van een vastgoedportfolio met Mensen" ontworpen. Dit model geeft dus aan wat de verwachtingen zijn van de kernpunten van vastgoedmanagement in de toekomst. Wanneer deze verschuiving binnen het vastgoedmanagement precies plaats zal gaan plaatsvinden is onbekend. Het is ook niet gegarandeerd dat deze verschuiving precies op deze manier plaats zal gaan vinden. Het "Model voor het Creëren van een Vastgoedportfolio met Mensen" kan voor de vastgoedmanager die geïnteresseerd is in deze theorie een leidraad en inspiratiebron zijn om in zijn werk toe te passen. -Cornelis, A., Logica van het gevoel, stabiliteitslagen in de cultuur als nesteling der emoties, 1993, Amsterdam / Brussel / Middelburg, Uitgave Stichting Essence, 747 pag., ISBN 90-72258-02-9Architectur
Author Correction: New perspectives on Neanderthal dispersal and turnover from Stajnia Cave (Poland)
No full textThe Author contributions section now reads:“W.N., A.N. and S.T. designed research; A.P., M.H., W.N., S.B., M.U., A.M., H.F., M.D.B., P.S., K.S., M.Ż., A.W., A.N. and S.T. performed research; A.P., M.H., W.N., S.B., M.U., A.M., H.F., M.D.B., P.S., K.S., M.Ż., A.W., A.N. and S.T. analysed data; A.P., M.H., S.T., W.N. and S.B. wrote the paper with the collaboration of all the co-authors.
Announcement of the National Academy of Science's establishment of an office at Camp Kilmer
No full textAfter the Soviets suppressed the Revolution in Hungary in 1956, approximately 200,000 Hungarians fled the country. Many Hungarian refugees came to New Jersey, some of whom were housed at Camp Kilmer, a military post near New Brunswick. Many members of the nearby Rutgers University community worked to help the refugees. In this document, the National Academy of Sciences announces its establishment of an office at the refugee center at Camp Kilmer. The point of the office is to interview Hungarian scientists and engineers in order to evaluate their areas and levels of expertise. Based on the evaluations, the Hungarians will be assisted with employment and research opportunities
Structure, function and management of semi-natural habitats for conservation biological control : A review of European studies
No full textDifferent semi-natural habitats occur on farmland, and it is the vegetation's traits and structure that subsequently determine their ability to support natural enemies and their associated contribution to conservation biocontrol. New habitats can be created and existing ones improved with agri-environment scheme funding in all EU member states. Understanding the contribution of each habitat type can aid the development of conservation control strategies. Here we review the extent to which the predominant habitat types in Europe support natural enemies, whether this results in enhanced natural enemy densities in the adjacent crop and whether this leads to reduced pest densities. Considerable variation exists in the available information for the different habitat types and trophic levels. Natural enemies within each habitat were the most studied, with less information on whether they were enhanced in adjacent fields, while their impact on pests was rarely investigated. Most information was available for woody and herbaceous linear habitats, yet not for woodland which can be the most common semi-natural habitat in many regions. While the management and design of habitats offer potential to stimulate conservation biocontrol, we also identified knowledge gaps. A better understanding of the relationship between resource availability and arthropod communities across habitat types, the spatiotemporal distribution of resources in the landscape and interactions with other factors that play a role in pest regulation could contribute to an informed management of semi-natural habitats for biocontrol.</p
Editorial
No full textEditorialGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Real Estate Managemen
Ultra-thin ferroelectrics
No full textDevice applications of ferroelectrics have not only utilized the switchable polarization but also adopted myriads of emerging physical properties. In particular, ferroelectrics in ultra-thin limit have recently attracted considerable scientific and technological interest owing to the increasing demand for miniaturization of electronic devices. In the last two decades, ultra-thin ferroelectrics have rapidly developed with the advances in the theoretical calculations, synthesis, and characterization techniques. However, atomic-scale realization and rigorous characterization of ultra-thin ferroelectricity remain challenging. In this review, we summarize state-of-the-art researches on ultra-thin ferroelectrics. We provide a brief overview of the history and underlying mechanism of ferroelectrics in the context of ultra-thin ferroelectrics. In particular, we discuss complex transition metal oxide ultra-thin ferroelectrics, ferroelectric two-dimensional materials, and fluorite HfO2-based ultra-thin ferroelectrics. Further, we discuss the characterization techniques used to verify the ultra-thin limit of ferroelectricity, followed by device applications based on various emergent properties of ultra-thin ferroelectrics. Finally, we provide a brief conclusion and outlook. © 2021 The Author(s)N
The role of open access data in geospatial electrification planning and the achievement of SDG7. an OnSSET-based case study for Malawi (vol 12, 1395, 2019)
No full textThe authors wish to make a change in author names (adding new author—Dimitrios Mentis) to this paper [1]: Author Contributions On page 19, author contributions are updated as follows: Conceptualization, A.K., D.M. and M.H.; Methodology, A.K., A.S., B.K. and D.M.; Software, A.K., B.K., A.S. and C.A.; Validation, M.H.; Formal Analysis, A.K.; Investigation, A.K.; Resources, A.K. and B.K.; Data Curation, A.K., B.K. and A.S.; Writing—Original Draft Preparation, A.K.; Writing—Review and Editing, A.K., D.M., M.H., C.A.; Visualization, A.K. and B.K.; Supervision, M.H.; Project Administration, M.H.; Funding Acquisition, M.H., D.M. and A.K. All authors have read and agreed to the published version of the manuscript. Funding On page 19, funding sources are updated as follows: This research was funded by the World Bank under the contract number 7185716 and partially by (a) the Swedish Center for Smart Grids and Energy Storage (SweGRIDS-ABB) under grant VF-2015-0018 and (b) the ÅForsk Foundation under grant 17-604. The authors would like to apologize for any inconvenience caused to the readers and contributors by these changes. The changes do not a ect the scientific results. The manuscript will be updated, and the original will remain online on the article webpage, with a reference to this correction.</p
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