TY - JOUR A1 - Lehn-Stefan, Angela A1 - Peter, Andreas A1 - Machann, Jürgen A1 - Schick, Fritz A1 - Randrianarisoa, Elko A1 - Heni, Martin A1 - Wagner, Robert A1 - Birkenfeld, Andreas L. A1 - Fritsche, Andreas A1 - Schulze, Matthias Bernd A1 - Stefan, Norbert A1 - Kantartzis, Konstantinos T1 - Impaired metabolic health and low cardiorespiratory fitness independently associate with subclinical atherosclerosis in obesity JF - The journal of clinical endocrinology & metabolism N2 - Context For a given body mass index (BMI), both impaired metabolic health (MH) and reduced cardiorespiratory fitness (CRF) associate with increased risk of cardiovascular disease (CVD). Objective It remains unknown whether both risk phenotypes relate to CVD independently of each other, and whether these relationships differ in normal weight, overweight, and obese subjects. Methods Data from 421 participants from the Tubingen Diabetes Family Study, who had measurements of anthropometrics, metabolic parameters, CRF (maximal aerobic capacity [VO2max]) and carotid intima-media thickness (cIMT), an early marker of atherosclerosis, were analyzed. Subjects were divided by BMI and MH status into 6 phenotypes. Results In univariate analyses, older age, increased BMI, and a metabolic risk profile correlated positively, while insulin sensitivity and VO2max negatively with cIMT. In multivariable analyses in obese subjects, older age, male sex, lower VO2max (std. ss -0.21, P = 0.002) and impaired MH (std. ss 0.13, P = 0.02) were independent determinants of increased cIMT. After adjustment for age and sex, subjects with metabolically healthy obesity (MHO) had higher cIMT than subjects with metabolically healthy normal weight (MHNW; 0.59 +/- 0.009 vs 0.52 +/- 0.01 mm; P < 0.05). When VO2max was additionally included in this model, the difference in cIMT between MHO and MHNW groups became statistically nonsignificant (0.58 +/- 0.009 vs 0.56 +/- 0.02 mm; P > 0.05). Conclusion These data suggest that impaired MH and low CRF independently determine increased cIMT in obese subjects and that low CRF may explain part of the increased CVD risk observed in MHO compared with MHNW. KW - Metabolically healthy obesity KW - cardiorespiratory fitness KW - subclinical KW - atherosclerosis KW - obesity KW - carotid intima-media thickness KW - cardiovascular KW - disease Y1 - 2022 U6 - https://doi.org/10.1210/clinem/dgac091 SN - 0021-972X SN - 1945-7197 VL - 107 IS - 6 SP - E2417 EP - E2424 PB - Endocrine Society CY - Washington ER - TY - JOUR A1 - Allan, Eric A1 - Bossdorf, Oliver A1 - Dormann, Carsten F. A1 - Prati, Daniel A1 - Gossner, Martin M. A1 - Tscharntke, Teja A1 - Blüthgen, Nico A1 - Bellach, Michaela A1 - Birkhofer, Klaus A1 - Boch, Steffen A1 - Böhm, Stefan A1 - Börschig, Carmen A1 - Chatzinotas, Antonis A1 - Christ, Sabina A1 - Daniel, Rolf A1 - Diekötter, Tim A1 - Fischer, Christiane A1 - Friedl, Thomas A1 - Glaser, Karin A1 - Hallmann, Christine A1 - Hodac, Ladislav A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klein, Alexandra-Maria A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Krauss, Jochen A1 - Lange, Markus A1 - Morris, E. Kathryn A1 - Müller, Jörg A1 - Nacke, Heiko A1 - Pasalic, Esther A1 - Rillig, Matthias C. A1 - Rothenwoehrer, Christoph A1 - Schally, Peter A1 - Scherber, Christoph A1 - Schulze, Waltraud X. A1 - Socher, Stephanie A. A1 - Steckel, Juliane A1 - Steffan-Dewenter, Ingolf A1 - Türke, Manfred A1 - Weiner, Christiane N. A1 - Werner, Michael A1 - Westphal, Catrin A1 - Wolters, Volkmar A1 - Wubet, Tesfaye A1 - Gockel, Sonja A1 - Gorke, Martin A1 - Hemp, Andreas A1 - Renner, Swen C. A1 - Schöning, Ingo A1 - Pfeiffer, Simone A1 - König-Ries, Birgitta A1 - Buscot, Francois A1 - Linsenmair, Karl Eduard A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. A1 - Fischer, Markus T1 - Interannual variation in land-use intensity enhances grassland multidiversity JF - Proceedings of the National Academy of Sciences of the United States of America N2 - Although temporal heterogeneity is a well-accepted driver of biodiversity, effects of interannual variation in land-use intensity (LUI) have not been addressed yet. Additionally, responses to land use can differ greatly among different organisms; therefore, overall effects of land-use on total local biodiversity are hardly known. To test for effects of LUI (quantified as the combined intensity of fertilization, grazing, and mowing) and interannual variation in LUI (SD in LUI across time), we introduce a unique measure of whole-ecosystem biodiversity, multidiversity. This synthesizes individual diversity measures across up to 49 taxonomic groups of plants, animals, fungi, and bacteria from 150 grasslands. Multidiversity declined with increasing LUI among grasslands, particularly for rarer species and aboveground organisms, whereas common species and belowground groups were less sensitive. However, a high level of interannual variation in LUI increased overall multidiversity at low LUI and was even more beneficial for rarer species because it slowed the rate at which the multidiversity of rare species declined with increasing LUI. In more intensively managed grasslands, the diversity of rarer species was, on average, 18% of the maximum diversity across all grasslands when LUI was static over time but increased to 31% of the maximum when LUI changed maximally over time. In addition to decreasing overall LUI, we suggest varying LUI across years as a complementary strategy to promote biodiversity conservation. KW - biodiversity loss KW - agricultural grasslands KW - Biodiversity Exploratories Y1 - 2014 U6 - https://doi.org/10.1073/pnas.1312213111 SN - 0027-8424 VL - 111 IS - 1 SP - 308 EP - 313 PB - National Acad. of Sciences CY - Washington ER - TY - GEN A1 - de Vera, Jean-Pierre Paul A1 - Alawi, Mashal A1 - Backhaus, Theresa A1 - Baque, Mickael A1 - Billi, Daniela A1 - Boettger, Ute A1 - Berger, Thomas A1 - Bohmeier, Maria A1 - Cockell, Charles A1 - Demets, Rene A1 - de la Torre Noetzel, Rosa A1 - Edwards, Howell A1 - Elsaesser, Andreas A1 - Fagliarone, Claudia A1 - Fiedler, Annelie A1 - Foing, Bernard A1 - Foucher, Frederic A1 - Fritz, Jörg A1 - Hanke, Franziska A1 - Herzog, Thomas A1 - Horneck, Gerda A1 - Hübers, Heinz-Wilhelm A1 - Huwe, Björn A1 - Joshi, Jasmin Radha A1 - Kozyrovska, Natalia A1 - Kruchten, Martha A1 - Lasch, Peter A1 - Lee, Natuschka A1 - Leuko, Stefan A1 - Leya, Thomas A1 - Lorek, Andreas A1 - Martinez-Frias, Jesus A1 - Meessen, Joachim A1 - Moritz, Sophie A1 - Moeller, Ralf A1 - Olsson-Francis, Karen A1 - Onofri, Silvano A1 - Ott, Sieglinde A1 - Pacelli, Claudia A1 - Podolich, Olga A1 - Rabbow, Elke A1 - Reitz, Günther A1 - Rettberg, Petra A1 - Reva, Oleg A1 - Rothschild, Lynn A1 - Garcia Sancho, Leo A1 - Schulze-Makuch, Dirk A1 - Selbmann, Laura A1 - Serrano, Paloma A1 - Szewzyk, Ulrich A1 - Verseux, Cyprien A1 - Wadsworth, Jennifer A1 - Wagner, Dirk A1 - Westall, Frances A1 - Wolter, David A1 - Zucconi, Laura T1 - Limits of life and the habitability of Mars BT - the ESA space experiment BIOMEX on the ISS T2 - Astrobiology N2 - BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit. KW - EXPOSE-R2 KW - BIOMEX KW - Habitability KW - Limits of life KW - Extremophiles KW - Mars Y1 - 2019 U6 - https://doi.org/10.1089/ast.2018.1897 SN - 1531-1074 SN - 1557-8070 VL - 19 IS - 2 SP - 145 EP - 157 PB - Liebert CY - New Rochelle ER - TY - JOUR A1 - Förstner, Bernd Rainer A1 - Böttger, Sarah Jane A1 - Moldavski, Alexander A1 - Bajbouj, Malek A1 - Pfennig, Andrea A1 - Manook, Andre A1 - Ising, Marcus A1 - Pittig, Andre A1 - Heinig, Ingmar A1 - Heinz, Andreas A1 - Mathiak, Klaus A1 - Schulze, Thomas G. A1 - Schneider, Frank A1 - Kamp-Becker, Inge A1 - Meyer-Lindenberg, Andreas A1 - Padberg, Frank A1 - Banaschewski, Tobias A1 - Bauer, Michael A1 - Rupprecht, Rainer A1 - Wittchen, Hans-Ulrich A1 - Rapp, Michael A. A1 - Tschorn, Mira T1 - The associations of positive and negative valence systems, cognitive systems and social processes on disease severity in anxiety and depressive disorders JF - Frontiers in psychiatry N2 - Background Anxiety and depressive disorders share common features of mood dysfunctions. This has stimulated interest in transdiagnostic dimensional research as proposed by the Research Domain Criteria (RDoC) approach by the National Institute of Mental Health (NIMH) aiming to improve the understanding of underlying disease mechanisms. The purpose of this study was to investigate the processing of RDoC domains in relation to disease severity in order to identify latent disorder-specific as well as transdiagnostic indicators of disease severity in patients with anxiety and depressive disorders. Methods Within the German research network for mental disorders, 895 participants (n = 476 female, n = 602 anxiety disorder, n = 257 depressive disorder) were recruited for the Phenotypic, Diagnostic and Clinical Domain Assessment Network Germany (PD-CAN) and included in this cross-sectional study. We performed incremental regression models to investigate the association of four RDoC domains on disease severity in patients with affective disorders: Positive (PVS) and Negative Valance System (NVS), Cognitive Systems (CS) and Social Processes (SP). Results The results confirmed a transdiagnostic relationship for all four domains, as we found significant main effects on disease severity within domain-specific models (PVS: & beta; = -0.35; NVS: & beta; = 0.39; CS: & beta; = -0.12; SP: & beta; = -0.32). We also found three significant interaction effects with main diagnosis showing a disease-specific association. Limitations The cross-sectional study design prevents causal conclusions. Further limitations include possible outliers and heteroskedasticity in all regression models which we appropriately controlled for. Conclusion Our key results show that symptom burden in anxiety and depressive disorders is associated with latent RDoC indicators in transdiagnostic and disease-specific ways. KW - Research Domain Criteria KW - depression KW - anxiety disoders KW - disease severity KW - transdiagnostic KW - RDoC Y1 - 2023 U6 - https://doi.org/10.3389/fpsyt.2023.1161097 SN - 1664-0640 VL - 14 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Förstner, Bernd R. A1 - Tschorn, Mira A1 - Reinoso-Schiller, Nicolas A1 - Maričić, Lea Mascarell A1 - Röcher, Erik A1 - Kalman, Janos L. A1 - Stroth, Sanna A1 - Mayer, Annalina V. A1 - Schwarz, Kristina A1 - Kaiser, Anna A1 - Pfennig, Andrea A1 - Manook, André A1 - Ising, Marcus A1 - Heinig, Ingmar A1 - Pittig, Andre A1 - Heinz, Andreas A1 - Mathiak, Klaus A1 - Schulze, Thomas G. A1 - Schneider, Frank A1 - Kamp-Becker, Inge A1 - Meyer-Lindenberg, Andreas A1 - Padberg, Frank A1 - Banaschewski, Tobias A1 - Bauer, Michael A1 - Rupprecht, Rainer A1 - Wittchen, Hans-Ulrich A1 - Rapp, Michael A. T1 - Mapping research domain criteria using a transdiagnostic mini-RDoC assessment in mental disorders: a confirmatory factor analysis JF - European archives of psychiatry and clinical neuroscience N2 - This study aimed to build on the relationship of well-established self-report and behavioral assessments to the latent constructs positive (PVS) and negative valence systems (NVS), cognitive systems (CS), and social processes (SP) of the Research Domain Criteria (RDoC) framework in a large transnosological population which cuts across DSM/ICD-10 disorder criteria categories. One thousand four hundred and thirty one participants (42.1% suffering from anxiety/fear-related, 18.2% from depressive, 7.9% from schizophrenia spectrum, 7.5% from bipolar, 3.4% from autism spectrum, 2.2% from other disorders, 18.4% healthy controls, and 0.2% with no diagnosis specified) recruited in studies within the German research network for mental disorders for the Phenotypic, Diagnostic and Clinical Domain Assessment Network Germany (PD-CAN) were examined with a Mini-RDoC-Assessment including behavioral and self-report measures. The respective data was analyzed with confirmatory factor analysis (CFA) to delineate the underlying latent RDoC-structure. A revised four-factor model reflecting the core domains positive and negative valence systems as well as cognitive systems and social processes showed a good fit across this sample and showed significantly better fit compared to a one factor solution. The connections between the domains PVS, NVS and SP could be substantiated, indicating a universal latent structure spanning across known nosological entities. This study is the first to give an impression on the latent structure and intercorrelations between four core Research Domain Criteria in a transnosological sample. We emphasize the possibility of using already existing and well validated self-report and behavioral measurements to capture aspects of the latent structure informed by the RDoC matrix. KW - Diagnosis and classification KW - Research Domain Criteria KW - PD-CAN KW - Confirmatory factor analysis CFA KW - RDoC KW - Transdiagnostic Y1 - 2022 U6 - https://doi.org/10.1007/s00406-022-01440-6 SN - 0940-1334 SN - 1433-8491 VL - 273 IS - 3 SP - 527 EP - 539 PB - Springer Nature CY - Heidelberg ER - TY - THES A1 - Schulze, Andreas T1 - Demographics of supermassive black holes T1 - Demgraphie supermassereicher Schwarzer Löcher N2 - Supermassive black holes are a fundamental component of the universe in general and of galaxies in particular. Almost every massive galaxy harbours a supermassive black hole (SMBH) in its center. Furthermore, there is a close connection between the growth of the SMBH and the evolution of its host galaxy, manifested in the relationship between the mass of the black hole and various properties of the galaxy's spheroid component, like its stellar velocity dispersion, luminosity or mass. Understanding this relationship and the growth of SMBHs is essential for our picture of galaxy formation and evolution. In this thesis, I make several contributions to improve our knowledge on the census of SMBHs and on the coevolution of black holes and galaxies. The first route I follow on this road is to obtain a complete census of the black hole population and its properties. Here, I focus particularly on active black holes, observable as Active Galactic Nuclei (AGN) or quasars. These are found in large surveys of the sky. In this thesis, I use one of these surveys, the Hamburg/ESO survey (HES), to study the AGN population in the local volume (z~0). The demographics of AGN are traditionally represented by the AGN luminosity function, the distribution function of AGN at a given luminosity. I determined the local (z<0.3) optical luminosity function of so-called type 1 AGN, based on the broad band B_J magnitudes and AGN broad Halpha emission line luminosities, free of contamination from the host galaxy. I combined this result with fainter data from the Sloan Digital Sky Survey (SDSS) and constructed the best current optical AGN luminosity function at z~0. The comparison of the luminosity function with higher redshifts supports the current notion of 'AGN downsizing', i.e. the space density of the most luminous AGN peaks at higher redshifts and the space density of less luminous AGN peaks at lower redshifts. However, the AGN luminosity function does not reveal the full picture of active black hole demographics. This requires knowledge of the physical quantities, foremost the black hole mass and the accretion rate of the black hole, and the respective distribution functions, the active black hole mass function and the Eddington ratio distribution function. I developed a method for an unbiased estimate of these two distribution functions, employing a maximum likelihood technique and fully account for the selection function. I used this method to determine the active black hole mass function and the Eddington ratio distribution function for the local universe from the HES. I found a wide intrinsic distribution of black hole accretion rates and black hole masses. The comparison of the local active black hole mass function with the local total black hole mass function reveals evidence for 'AGN downsizing', in the sense that in the local universe the most massive black holes are in a less active stage then lower mass black holes. The second route I follow is a study of redshift evolution in the black hole-galaxy relations. While theoretical models can in general explain the existence of these relations, their redshift evolution puts strong constraints on these models. Observational studies on the black hole-galaxy relations naturally suffer from selection effects. These can potentially bias the conclusions inferred from the observations, if they are not taken into account. I investigated the issue of selection effects on type 1 AGN samples in detail and discuss various sources of bias, e.g. an AGN luminosity bias, an active fraction bias and an AGN evolution bias. If the selection function of the observational sample and the underlying distribution functions are known, it is possible to correct for this bias. I present a fitting method to obtain an unbiased estimate of the intrinsic black hole-galaxy relations from samples that are affected by selection effects. Third, I try to improve our census of dormant black holes and the determination of their masses. One of the most important techniques to determine the black hole mass in quiescent galaxies is via stellar dynamical modeling. This method employs photometric and kinematic observations of the galaxy and infers the gravitational potential from the stellar orbits. This method can reveal the presence of the black hole and give its mass, if the sphere of the black hole's gravitational influence is spatially resolved. However, usually the presence of a dark matter halo is ignored in the dynamical modeling, potentially causing a bias on the determined black hole mass. I ran dynamical models for a sample of 12 galaxies, including a dark matter halo. For galaxies for which the black hole's sphere of influence is not well resolved, I found that the black hole mass is systematically underestimated when the dark matter halo is ignored, while there is almost no effect for galaxies with well resolved sphere of influence. N2 - Supermassereiche Schwarze Löcher sind ein fundamentaler Bestandteil unseres Universims im Allgemeinen, und von Galaxien im Besonderen. Fast jede massereiche Galaxie beherbergt ein supermassereiches Schwarzes Loch in seinem Zentrum. Außerdem existiert eine enge Beziehung zwischen dem Wachstum des Schwarzen Loches und der Entwicklung seiner umgebenden Galaxie. Diese zeigt sich besonders in der engen Beziehung zwischen der Masse eines Schwarzen Loches und den Eigenschaften der sphäroidalen Komponente der Galaxie, beispielsweise seiner stellaren Geschwindigkeitsdispersion, seiner Leuchtkraft und seiner Masse. Diese Beziehung erklären zu können, sowie das Wachstum von Schwarzen Löchern zu verstehen, liefert einen wichtigen Beitrag zu unserem Bild der Entstehung und Entwicklung von Galaxien. In dieser Arbeit steuere ich verschiedene Beiträge dazu bei unser Verständnis des Vorkommens Schwarzer Löcher und der Beziehung zu ihren Galaxien zu verbessern. Zunächst versuche ich ein vollständiges Bild der Anzahl und Eigenschaften Schwarzer Löcher zu erhalten. Dazu beschränke ich mich auf aktive Schwarze Löcher, wie man sie im Universum als Aktive Galaxienkerne (AGN) in großen Himmelsdurchmusterungen finden kann. Ich benutze eine solche Durchmusterung, das Hamburg/ESO Survey (HES), um die AGN Population im lokalen Universum zu studieren. Dazu habe ich die optische Leuchtkraftfunktion von AGN bestimmt. Diese habe ich mit anderen Ergebnissen leuchtschwächerer AGN kombiniert um die bisher beste AGN Leuchtkraftfunktion im lokalen Universum zu erhalten. Der Vergleich mit Ergebnissen bei höherer kosmischer Rotverschiebung bestätigt unser Bild des sogenannten "AGN downsizing". Dies sagt aus, dass leuchtkräftige AGN bei hoher Rotverschiebung am häufigsten vorkommen, während leuchtschwache AGN bei niedriger Rotverschiebung am häufigsten sind. Allerdings verrät uns die AGN Leuchtkraftfunktion allein noch nicht das ganze Bild der Demographie Schwarzer Löcher. Vielmehr sind wir an den zugrunde liegenden Eigenschaften, vor allem der Masse und der Akkretionsrate der Schwarzen Löcher, sowie deren statistischen Verteilungsfunktionen, interessiert. Ich habe eine Methode entwickelt um diese beiden Verteilungsfunktionen zu bestimmen, basierend auf der Maximum-Likelihood-Methode. Ich habe diese Methode benutzt um die aktive Massenfunktion Schwarzer Löcher, sowie die Verteilungsfunktion ihrer Akkretionsraten für das lokale Universum aus dem HES zu bestimmen. Sowohl die Akkretionsraten, als auch die Massen der Schwarzen Löcher zeigen intrinsisch eine breite Verteilung, im Gegensatz zur schmaleren beobachtbaren Verteilung. Der Vergleich der aktiven Massenfunktion mit der gesamten Massenfunktion Schwarzer Löcher zeigt ebenfalls Hinweise auf "AGN downsizing". Als nächstes habe ich mich mit Untersuchungen zur zeitlichen Entwicklung in den Beziehungen zwischen Schwarzem Loch und Galaxie beschäftigt. Diese kann helfen unser theoretisches Veständnis der physikalischen Vorgänge zu verbessern. Beobachtungen sind immer auch Auswahleffekten unterworfen. Diese können die Schlussfolgerungen aus den Beobachtungen zur Entwicklung in den Beziehungen beeinflussen, wenn sie nicht entsprechend berücksichtigt werden. Ich habe den Einfluss von Auswahleffekten auf AGN Stichproben im Detail untersucht, und verschiedende möchgliche Einflussquellen identifiziert, die die Beziehung verfälschen können. Wenn die Auswahlkriterien der Stichprobe, sowie die zugrunde liegenden Verteilungen bekannt sind, so ist es möglich für die Auswahleffekte zu korrigieren. Ich habe eine Methode entwickelt, mit der man die intrinsische Beziehung zwischem Schwarzem Loch und Galaxie aus den Beobachtungen rekonstruieren kann. Schließlich habe ich mich auch inaktiven Schwarzen Löchern und der Bestimmung ihrer Massen gewidmet. Eine der wichtigsten Methoden die Masse Schwarzer Löcher in normalen Galaxien zu bestimmen ist stellardynamische Modellierung. Diese Methode benutzt photometrische und kinematische Beobachtungen, und rekonstruiert daraus das Gravitationspotenzial aus der Analyse stellarer Orbits. Bisher wurde in diesen Modellen allerdings der Einfluss des Halos aus Dunkler Materie vernachlässigt. Dieser kann aber die Bestimmung der Masse des Schwarzen Loches beeinflussen. Ich habe 12 Galaxien mit Hilfe stellardynamischer Modellierung untersucht und dabei auch den Einfluss des Halos aus Dunkler Materie berücksichtigt. Für Galaxien bei denen der Einflussbereich des Schwarzen Loches nicht sehr gut räumlich aufgelöst war, wird die Masse des Schwarzen Loches systematisch unterschätzt, wenn der Dunkle Materie Halo nicht berücksichtigt wird. Auf der anderen Seite ist der Einfluss gering, wenn die Beobachtungen diesen Einflussbereich gut auflösen können. KW - Astrophysik KW - Quasare KW - Schwarze Löcher KW - AGN KW - Statistik KW - astrophysics KW - quasars KW - black holes KW - AGN KW - statistics Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-54464 ER - TY - THES A1 - Schulze, Andreas T1 - Liberalisierung von Netzindustrien T1 - Liberalisation in network based industries BT - eine ökonomische Analyse am Beispiel der Eisenbahn, der Telekommunikation und der leitungsgebundenen Energieversorgung BT - an economic analysis by case studies of railway, telecommunication and energy utilities N2 - 1. Problemstellung Die Liberalisierung von Netzindustrien stellt eine volkswirtschaftliche Problematik dar, die einerseits eine Vielzahl theoretisch ungelöster Fragen aufwirft und für die andererseits nunmehr auch in Deutschland wirtschaftspolitische Erfahrungen vorliegen. Die Ursachen der ökonomischen Probleme sind dabei nicht nur in bestimmten Branchenbesonderheiten der Netzindustrien zu suchen, sondern auch in einer verfehlten ordnungspolitischen Sonderbehandlung der netzgebundenen Wirtschaftsbereiche in der Vergangenheit. Entgegen den für eine marktwirtschaftliche Ordnung charakteristischen Prinzipien Wettbewerb und Privateigentum wurden Netzindustrien traditionell als wettbewerbliche Ausnahmebereiche behandelt und zumeist in Form öffentlicher Unternehmen geführt. Die Folge dessen waren (staatliche) Monopole, die eine relativ hohe Ineffizienz aufwiesen. Die ordnungspolitische Konsequenz dieses Befundes lautete daher Liberalisierung von Netzindustrien durch Privatisierung und Marktöffnung, d. h. ein Abbau von Marktzutrittsschranken durch Deregulierung. Wettbewerb stößt in Netzindustrien jedoch an Grenzen, weil die zur Produktion netzgebundener Dienstleistungen erforderliche Infrastruktur typischerweise ein nicht-angreifbares, natürliches Monopol darstellt, das sich in der Hand eines im Markt eingesessenen, vertikal integrierten Anbieters befindet. Daraus ergeben sich weitreichende Möglichkeiten zur Diskriminierung von Konkurrenten, die wettbewerbspolitischen Handlungsbedarf nach sich ziehen. Diesen gilt es in der vorliegenden Arbeit zu analysieren und alternative Lösungsansätze der Diskriminierungsproblematik zu diskutieren. 2. Besonderes Forschungsziel Die vorliegende Dissertation widmet sich der Liberalisierung von Netzindustrien aus ökonomischer Sicht, wobei insbesondere die Interdependenzen zwischen der Eigentums- und der Diskriminierungsproblematik berücksichtigt werden. Gleichwohl bildet die wettbewerbliche Öffnung der Märkte für netzgebundene Dienstleistungen aus volkswirtschaftlicher Sicht das Kernproblem und somit auch den zentralen Untersuchungsgegenstand dieser Arbeit. Die theoretische Analyse bleibt dabei nicht auf einen Forschungsansatz beschränkt, sondern es werden mehrere Facetten der Liberalisierung von der Ordnungs- über die Netzökonomik bis hin zur politischen Ökonomie betrachtet. In empirischer Hinsicht haben die in Deutschland in verschiedenen Netzindustrien realisierten Marktöffnungen bislang zu unterschiedlich intensiven Wettbewerbsprozessen geführt. Daher wird ein problemorientierter, intersektoraler Vergleich der Reformen und eine wettbewerbs-politische Beurteilung anhand der drei Marktmerkmale Marktstruktur, Marktverhalten und Marktergebnis vorgenommen, um die Liberalisierung in einzelnen Netzindustrien zu bewerten. Die Telekommunikation gilt dabei als Musterbeispiel für eine erfolgreiche Liberalisierung, weil die Deregulierung hier durch eine sektorspezifische Marktmachtkontrolle begleitet wird, wofür eigens eine Regulierungsbehörde geschaffen wurde. Vor diesem Hintergrund wird der mangelnde Wettbewerb in der Strom- und vor allem in der Gasversorgung sowie im Schienenverkehr häufig auf das Fehlen solcher Institutionen zurückgeführt. Aufgrund dessen werden hier die Eisenbahn, die Telekommunikation im Festnetz und die leitungsgebundene Energieversorgung als empirische Analyseobjekte ausgewählt, um die im Laufe der Untersuchung gewonnenen theoretischen Erkenntnisse exemplarisch an diesen Netzindustrien aufzuzeigen und die im Folgenden formulierte Arbeitshypothese zu überprüfen. 3. Methodik Die Arbeit gliedert sich in einen theoretischen und einen empirischen Teil. Die theoretisch zu untersuchende Frage bei der Liberalisierung von Netzindustrien lautet: Welcher institutionellen Arrangements bedarf es in Netzindustrien, um vormals monopolistisch organisierte in kompetitive Märkte zu überführen und darin nachhaltig einen effektiven Wettbewerb zu etablieren? Auf der Grundlage der erarbeiteten ordnungs- und wettbewerbsökonomischen Erkenntnisse wird nach allgemeingültigen Kriterien gesucht, um daraus einen Bewertungsmaßstab für den intersektoralen Vergleich von Liberalisierungsprozessen in verschiedenen Netzindustrien zu entwickeln. Als Arbeitsthese der empirischen Überprüfung im zweiten Teil dient die aus verschiedenen ökonomischen Blickwinkeln gewonnene und theoretisch zu fundierende Vermutung, dass es zur wirksamen Marktöffnung in Netzindustrien einer materiellen Privatisierung sowie einer effektiven und effizienten Marktmachtkontrolle im Bereich des Zugangs zur Netzinfrastruktur bedarf. Anhand dieser These werden die Liberalisierungsprozesse in den Netzsektoren Schienenverkehr, Telekommunikation sowie Energieversorgung in der Bundesrepublik Deutschland aus volkswirtschaftlicher Sicht beurteilt, und es wird auf verbleibenden ordnungspolitischen Reformbedarf hingewiesen. Die theoretischen Ergebnisse sind indes auch auf ähnliche, hier nicht dargestellte Infrastruktursektoren übertragbar. N2 - The liberalisation of network based industries represents an economic problem, which raises on the one hand a multiplicity of theoretically unresolved questions and for which exist now on the other hand experiences in economic policy in Germany. The causes of the economic problems are not only to be found thereby in certain industry characteristics of the network based industries, but also in a missed special treatment of the network based economic sectors in the past by the economic policy. However, competition pushes in network based industries at borders, because the infrastructure necessary for the production of network based services typically represents an non-open to attack, natural monopoly in the hand of an established, vertically integrated supplier. From it extensive possibilities for the discrimination of competitors result, the competition political action need draw. It applies to analyze these in the available work and to discuss alternative solutions of the discrimination problem. KW - Deregulierung KW - Liberalisierung KW - Privatisierung KW - Regulierung KW - Wettbewerbspolitik KW - Netzindustrien KW - network based industries Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-9599 ER - TY - RPRT A1 - Schulze, Andreas T1 - Die ordnungspolitische Problematik von Netzinfrastrukturen BT - eine institutionenökonomische Analyse N2 - Inhalt - Einführung in die Netzökonomik - Theoretischer Bezugsrahmen zur normativen Analyse derMarkt- und Wettbewerbsverhältnisse in Netzindustrien - Institutionelle Arrangements der Marktorganisation von Netzen T3 - Volkswirtschaftliche Diskussionsbeiträge - 33 Y1 - 1999 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13634 ER - TY - RPRT A1 - Schulze, Andreas T1 - Liberalisierung und Re-regulierung von Netzindustrien BT - Ordnungspolitische Paradoxon oder wettbewerbsökonomische Notwendigkeit? N2 - Inhalt 1 Ziele der Liberalisierung von Netzindustrien:Privatisierung staatlicher Monopole und wettbewerbliche Marktöffnung 2 Markt- und wettbewerbstheoretische Aspekte der Netzinfrastruktur 2.1 Netze als Teil der materiellen Infrastruktur 2.2 Netzinfrastruktur als öffentliches Gut oderInstrument der Daseinsvorsorge? 2.3 Netze als natürliche Monopole? 2.3.1 Nutzenrelevante Netzeffekte 2.3.2 Kostenbestimmende Netzeffekte 2.3.3 Wettbewerbspotenziale trotz Wettbewerbsversagen 3 Wettbewerbsökonomische Implikationen für Netzindustrien 3.1 Vertikale Integration in Netzindustrien 3.1.1 Transaktionskosten versus vertikale Integration 3.1.2 Wettbewerbsökonomische Probleme 3.2 Netzzugangsmodelle 3.3 Institutionelle Ausgestaltung der Wettbewerbsaufsicht 4 Fazit T3 - Volkswirtschaftliche Diskussionsbeiträge - 53 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13847 ER - TY - RPRT A1 - Schulze, Andreas T1 - Liberalisierungen in Netzindustrien aus polit-ökonomischer Sicht BT - eine positive Analyse der Interessenbedingtheit von Privatisierungen und Marktöffnungen am Beispiel netzgebundener Wirtschaftsbereiche N2 - Inhalt 1 Politikzyklus als konzeptioneller Bezugsrahmen 2 Ökonomische Problematik von Netzindustrien und Liberalisierungsgründe 3 Privatisierung und Marktöffnung als wirtschaftspolitische Aufgaben 4 Politisierung von Liberalisierungsinteressen 4.1 Politiker als Intermediäre 4.2 Zielkonflikte und Interdependenzen mit anderen Politikfeldern 5 Rent-Seeking-Aktivitäten in Netzindustrien 5.1 Der „Markt“ für Rent-Seeking-Aktivitäten 5.2 Der „Wettbewerb“ von Interessengruppen 6 Administrative Umsetzung und Evaluierung von Liberalisierungen 7 Fazit T3 - Volkswirtschaftliche Diskussionsbeiträge - 68 Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14147 ER - TY - RPRT A1 - Schulze, Andreas T1 - Alternative Liberalisierungsansätze in Netzindustrien BT - Beitrag zum Workshop des Instituts für Wirtschaftsforschung Deregulierung in Deutschland Theoretische und empirische Analysen, Halle/Saale, 26.3.2004 N2 - Inhalt 1 Einführung und Grundlagen 1.1 Problemstellung und Vorgehensweise 1.2 Ordnungsökonomische Systematisierung 1.3 „Neue“ Besonderheitenlehre für Netzindustrien 2 Ansatzpunkte zur Liberalisierung in Netzindustrien 2.1 Liberalisierung durch Privatisierung 2.1.1 Interdependenz von Privatisierung und Marktöffnung 2.1.2 Privatisierungsstufen 2.2 Liberalisierung durch Deregulierung und Re-Regulierung 2.2.1 Abgrenzung des relevanten Marktes: Netzinfrastruktur versus Netzdienstleistungen 2.2.2 Lokalisierung und Kontrolle von Marktmacht bei Netzinfrastruktur 2.3 Modelle zur Gewährleistung eines diskriminierungsfreien Netzzugangs 2.3.1 Verhandelter Netzzugang mit Missbrauchsaufsicht im Sinne der Essential-Facilities-Doktrin 2.3.2 Staatliche Regulierung des Netzzugangs 2.4 Theorie der vertikalen (Des-)Integration 2.4.1 Allokativ-statische, wohlfahrtsökonomische Analyse vertikaler Integration 2.4.2 Institutionenökonomische Analyse vertikaler Integration 2.4.3 Dynamische, wettbewerbsökonomische Analyse vertikaler Integration 2.4.4 Konsequenz: Vertikale Desintegration 3 Institutionelle Ausgestaltung der Wettbewerbsaufsicht 3.1 Systematisierung der Träger und Kompetenzabgrenzung 3.2 Kriterien für eine effiziente Wettbewerbsaufsicht 4 Schlussfolgerungen und intersektoraler Vergleich des Liberalisierungsprozessesin Netzindustrien T3 - Volkswirtschaftliche Diskussionsbeiträge - 64 Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14068 ER - TY - JOUR A1 - Schubarth, Wilfried A1 - Schulze-Reichelt, Friederike A1 - Mauermeister, Sylvi A1 - Seidel, Andreas A1 - Apostolow, Benjamin T1 - Studieneingang optimieren! BT - Empfehlungen zur Weiterentwicklung der Studieneingangsphase an Hochschulen JF - Alles auf Anfang! Befunde und Perspektiven zum Studieneingang Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428605 SN - 978-3-86956-452-4 SN - 2192-1075 SN - 2192-1083 SP - 355 EP - 369 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Schubarth, Wilfried A1 - Schulze-Reichelt, Friederike A1 - Mauermeister, Sylvi A1 - Seidel, Andreas A1 - Hartmann, Nina T1 - Einführung in den Band JF - Alles auf Anfang! Befunde und Perspektiven zum Studieneingang Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428342 SN - 978-3-86956-452-4 SN - 2192-1075 SN - 2192-1083 SP - 13 EP - 22 PB - Universtitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Schneider, Tobias A1 - Kohl, Benjamin A1 - Sauter, Tilman A1 - Kratz, Karl A1 - Lendlein, Andreas A1 - Ertel, Wolfgang A1 - Schulze-Tanzil, Gundula T1 - Influence of fiber orientation in electrospun polymer scaffolds on viability, adhesion and differentiation of articular chondrocytes JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Degradable polymers with a tailorable degradation rate might be promising candidate materials for biomaterial-based cartilage repair. In view of the poor intrinsic healing capability of cartilage, implantation of autologous chondrocytes seeded on a biocompatible slow degrading polymer might be an encouraging approach to improve cartilage repair in the future. This study was undertaken to test if the fiber orientation (random versus aligned) of two different degradable polymers and a polymer intended for long term applications could influence primary articular chondrocytes growth and ultrastructure. A degradable copoly(ether) esterurethane (PDC) was synthesized via co-condensation of poly(p-dioxanone) diol and poly(epsilon-caprolactone) diol using an aliphatic diisocyanate as linker. Poly(p-dioxanone) (PPDO) was applied as commercially available degradable polymer, while polyetherimide (PEI) was chosen as biomaterial enabling surface functionalization. The fibrous scaffolds of PDC and PPDO were obtained by electrospinning using 1,1,1,3,3,3 hexafluoro-2-propanol (HFP), while for PEI dimethyl acetamide (DMAc) was applied as solvent. Primary porcine articular chondrocytes were seeded at different cell densities on the fibrous polymer scaffolds and analyzed for viability (fluorescein diacetate/ethidiumbromide staining), for type II collagen synthesis (immunolabelling), ultrastructure and orientation on the fibers (SEM: scanning electron microscopy). Vital chondrocytes adhered on all electrospun scaffolds irrespective of random and aligned topologies. In addition, the chondrocytes produced the cartilage-specific type II collagen on all tested polymer topologies suggesting their differentiated functions. SEM revealed an almost flattened chondrocytes shape on scaffolds with random fiber orientation: whereby chondrocytes growth remained mainly restricted to the scaffold surface. On aligned fibers the chondrocytes exhibited a more spindle-shaped morphology with rougher cell surfaces but only a minority of the cells aligned according to the fibers. As a next step the reduction of the fiber diameter of electrospun scaffolds should be addressed as an important parameter to mimic cartilage ECM structure. KW - Chondrocytes KW - electrospinning KW - scaffold KW - differentiation KW - multiblock copolymer Y1 - 2012 U6 - https://doi.org/10.3233/CH-2012-1608 SN - 1386-0291 VL - 52 IS - 2-4 SP - 325 EP - 336 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Grüter, Doris A1 - Stölting, Erhard A1 - Peitsch, Helmut A1 - Fuhrmann, Wilfried A1 - Franz, Norbert A1 - Blasius, Bernd A1 - Schulze, Andreas A1 - Plaul, Yvonne T1 - Portal = Heiße Tage: Vom Sommerloch zur gefühlten Inflation BT - Die Potsdamer Universitätszeitung N2 - Aus dem Inhalt: Heiße Tage: Vom Sommerloch zur gefühlten Inflation -Ehrung für Hasso Plattner -Gebirgsbildung in Stein geschrieben -Auf Jiddisch: Aaron Eckstaedt singt und erzählt T3 - Portal: Das Potsdamer Universitätsmagazin - 07-09/2002 Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-501487 SN - 1618-6893 VL - 2002 ER - TY - JOUR A1 - Socher, Stephanie A. A1 - Prati, Daniel A1 - Boch, Steffen A1 - Müller, Jörg A1 - Baumbach, Henryk A1 - Gockel, Sonja A1 - Hemp, Andreas A1 - Schöning, Ingo A1 - Wells, Konstans A1 - Buscot, Francois A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, Karl Eduard A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. A1 - Fischer, Markus T1 - Interacting effects of fertilization, mowing and grazing on plant species diversity of 1500 grasslands in Germany differ between regions JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - The relationship of different types of grassland use with plant species richness and composition ( functional groups of herbs, legumes, and grasses) has so far been studied at small regional scales or comprising only few components of land use. We comprehensively studied the relationship between abandonment, fertilization, mowing intensity, and grazing by different livestock types on plant diversity and composition of 1514 grassland sites in three regions in North-East, Central and South-West Germany. We further considered environmental site conditions including soil type and topographical situation. Fertilized grasslands showed clearly reduced plant species diversity (-15% plant species richness, -0.1 Shannon diversity on fertilized grasslands plots of 16m(2)) and changed composition (-3% proportion of herb species), grazing had the second largest effects and mowing the smallest ones. Among the grazed sites, the ones grazed by sheep had higher than average species richness (+27%), and the cattle grazed ones lower (-42%). Further, these general results were strongly modulated by interactions between the different components of land use and by regional context: land-use effects differed largely in size and sometimes even in direction between regions. This highlights the importance of comparing different regions and to involve a large number of plots KW - Biodiversity exploratories KW - Functional groups KW - Land use type KW - Livestock type KW - Shannon diversity Y1 - 2013 U6 - https://doi.org/10.1016/j.baae.2012.12.003 SN - 1439-1791 VL - 14 IS - 2 SP - 126 EP - 136 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Fischer, Markus A1 - Bossdorf, Oliver A1 - Gockel, Sonja A1 - Haensel, Falk A1 - Hemp, Andreas A1 - Hessenmoeller, Dominik A1 - Korte, Gunnar A1 - Nieschulze, Jens A1 - Pfeiffer, Simone A1 - Prati, Daniel A1 - Renner, Swen A1 - Schoening, Ingo A1 - Schumacher, Uta A1 - Wells, Konstans A1 - Buscot, Francois A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, Karl Eduard A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. T1 - Implementing large-scale and long-term functional biodiversity research : the biodiversity exploratories N2 - Functional biodiversity research explores drivers and functional consequences of biodiversity changes Land use change is a major driver of changes of biodiversity and of biogeochemical and biological ecosystem processes and services However, land use effects on genetic and species diversity are well documented only for a few taxa and trophic networks We hardly know how different components of biodiversity and their responses to land use change are interrelated and very little about the simultaneous, and interacting, effects of land use on multiple ecosystem processes and services Moreover, we do not know to what extent land use effects on ecosystem processes and services are mediated by biodiversity change Thus, overall goals are on the one hand to understand the effects of land use on biodiversity and on the other to understand the modifying role of biodiversity change for land-use effects on ecosystem processes, including biogeochemical cycles To comprehensively address these Important questions, we recently established a new large-scale and long-term project for functional biodiversity, the Biodiversity Exploratories (www biodiversity-exploratories de) They comprise a hierarchical set of standardized field plots in three different regions of Germany covering manifold management types and intensities in grasslands and forests They serve as a joint research platform for currently 40 projects involving over 300 people studying various aspects of the relationships between land use biodiversity and ecosystem processes through monitoring, comparative observation and experiments We introduce guiding questions, concept and design of the Biodiversity Exploratories - including main aspects of selection and implementation of field plots and project structure - and we discuss the significance of this approach for further functional biodiversity research This includes the crucial relevance of a common study design encompassing variation in both drivers and outcomes of biodiversity change and ecosystem processes, the interdisciplinary integration of biodiversity and ecosystem researchers, the training of a new generation of integrative biodiversity researchers, and the stimulation of functional biodiversity research in real landscape contexts, in Germany and elsewhere. Y1 - 2010 UR - http://www.sciencedirect.com/science/journal/14391791 U6 - https://doi.org/10.1016/j.baae.2010.07.009 SN - 1439-1791 ER - TY - JOUR A1 - Boch, Steffen A1 - Prati, Daniel A1 - Müller, Jörg A1 - Socher, Stephanie A1 - Baumbach, Henryk A1 - Buscot, Francois A1 - Gockel, Sonja A1 - Hemp, Andreas A1 - Hessenmöller, Dominik A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, K. Eduard A1 - Pfeiffer, Simone A1 - Pommer, Ulf A1 - Schöning, Ingo A1 - Schulze, Ernst-Detlef A1 - Seilwinder, Claudia A1 - Weisser, Wolfgang W. A1 - Wells, Konstans A1 - Fischer, Markus T1 - High plant species richness indicates management-related disturbances rather than the conservation status of forests JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - There is a wealth of smaller-scale studies on the effects of forest management on plant diversity. However, studies comparing plant species diversity in forests with different management types and intensity, extending over different regions and forest stages, and including detailed information on site conditions are missing. We studied vascular plants on 1500 20 m x 20 m forest plots in three regions of Germany (Schwabische Alb, Hainich-Dun, Schorfheide-Chorin). In all regions, our study plots comprised different management types (unmanaged, selection cutting, deciduous and coniferous age-class forests, which resulted from clear cutting or shelterwood logging), various stand ages, site conditions, and levels of management-related disturbances. We analyzed how overall richness and richness of different plant functional groups (trees, shrubs, herbs, herbaceous species typically growing in forests and herbaceous light-demanding species) responded to the different management types. On average, plant species richness was 13% higher in age-class than in unmanaged forests, and did not differ between deciduous age-class and selection forests. In age-class forests of the Schwabische Alb and Hainich-Dun, coniferous stands had higher species richness than deciduous stands. Among age-class forests, older stands with large quantities of standing biomass were slightly poorer in shrub and light-demanding herb species than younger stands. Among deciduous forests, the richness of herbaceous forest species was generally lower in unmanaged than in managed forests, and it was even 20% lower in unmanaged than in selection forests in Hainich-Dun. Overall, these findings show that disturbances by management generally increase plant species richness. This suggests that total plant species richness is not suited as an indicator for the conservation status of forests, but rather indicates disturbances. KW - Biodiversity Exploratories KW - Coniferous plantations KW - Disturbance KW - Ellenberg indicator values KW - Forest management KW - Selection vs. age-class forests KW - Silviculture KW - Standing biomass KW - Typical forest species KW - Unmanaged vs. managed forests Y1 - 2013 U6 - https://doi.org/10.1016/j.baae.2013.06.001 SN - 1439-1791 VL - 14 IS - 6 SP - 496 EP - 505 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Braune, Steffen A1 - Walter, M. A1 - Schulze, F. A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Changes in platelet morphology and function during 24 hours of storage JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - For in vitro studies assessing the interaction of platelets with implant materials, common and standardized protocols for the preparation of platelet rich plasma (PRP) are lacking, which may lead to non-matching results due to the diversity of applied protocols. Particularly, the aging of platelets during prolonged preparation and storage times is discussed to lead to an underestimation of the material thrombogenicity. Here, we study the influence of whole blood-and PRP-storage times on changes in platelet morphology and function. Whole blood PFA100 closure times increased after stimulation with collagen/ADP and collagen/epinephrine. Twenty four hours after blood collection, both parameters were prolonged pathologically above the upper limit of the reference range. Numbers of circulating platelets, measured in PRP, decreased after four hours, but no longer after twenty four hours. Mean platelet volumes (MPV) and platelet large cell ratios (P-LCR, 12 fL - 40 fL) decreased over time. Immediately after blood collection, no debris or platelet aggregates could be visualized microscopically. After four hours, first debris and very small aggregates occurred. After 24 hours, platelet aggregates and also debris progressively increased. In accordance to this, the CASY system revealed an increase of platelet aggregates (up to 90 mu m diameter)with increasing storage time. The percentage of CD62P positive platelets and PF4 increased significantly with storage time in resting PRP. When soluble ADP was added to stored PRP samples, the number of activatable platelets decreased significantly over storage time. The present study reveals the importance of a consequent standardization in the preparation of WB and PRP. Platelet morphology and function, particularly platelet reactivity to adherent or soluble agonists in their surrounding milieu, changed rapidly outside the vascular system. This knowledge is of crucial interest, particularly in the field of biomaterial development for cardiovascular applications, and may help to define common standards in the in vitro hemocompatibility testing of biomaterials. KW - Platelet KW - platelet function KW - platelet rich plasma KW - whole blood KW - platelet aging KW - platelet storage KW - hemocompatibility KW - biomaterials Y1 - 2014 U6 - https://doi.org/10.3233/CH-141876 SN - 1386-0291 SN - 1875-8622 VL - 58 IS - 1 SP - 159 EP - 170 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Blüthgen, Nico A1 - Dormann, Carsten F. A1 - Prati, Daniel A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Hoelzel, Norbert A1 - Alt, Fabian A1 - Boch, Steffen A1 - Gockel, Sonja A1 - Hemp, Andreas A1 - Müller, Jörg A1 - Nieschulze, Jens A1 - Renner, Swen C. A1 - Schöning, Ingo A1 - Schumacher, Uta A1 - Socher, Stephanie A. A1 - Wells, Konstans A1 - Birkhofer, Klaus A1 - Buscot, Francois A1 - Oelmann, Yvonne A1 - Rothenwöhrer, Christoph A1 - Scherber, Christoph A1 - Tscharntke, Teja A1 - Weiner, Christiane N. A1 - Fischer, Markus A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, Karl Eduard A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. T1 - A quantitative index of land-use intensity in grasslands integrating mowing, grazing and fertilization JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - Land use is increasingly recognized as a major driver of biodiversity and ecosystem functioning in many current research projects. In grasslands, land use is often classified by categorical descriptors such as pastures versus meadows or fertilized versus unfertilized sites. However, to account for the quantitative variation of multiple land-use types in heterogeneous landscapes, a quantitative, continuous index of land-use intensity (LUI) is desirable. Here we define such a compound, additive LUI index for managed grasslands including meadows and pastures. The LUI index summarizes the standardized intensity of three components of land use, namely fertilization, mowing, and livestock grazing at each site. We examined the performance of the LUI index to predict selected response variables on up to 150 grassland sites in the Biodiversity Exploratories in three regions in Germany(Alb, Hainich, Schorlheide). We tested the average Ellenberg nitrogen indicator values of the plant community, nitrogen and phosphorus concentration in the aboveground plant biomass, plant-available phosphorus concentration in the top soil, and soil C/N ratio, and the first principle component of these five response variables. The LUI index significantly predicted the principal component of all five response variables, as well as some of the individual responses. Moreover, vascular plant diversity decreased significantly with LUI in two regions (Alb and Hainich). Inter-annual changes in management practice were pronounced from 2006 to 2008, particularly due to variation in grazing intensity. This rendered the selection of the appropriate reference year(s) an important decision for analyses of land-use effects, whereas details in the standardization of the index were of minor importance. We also tested several alternative calculations of a LUI index, but all are strongly linearly correlated to the proposed index. The proposed LUI index reduces the complexity of agricultural practices to a single dimension and may serve as a baseline to test how different groups of organisms and processes respond to land use. In combination with more detailed analyses, this index may help to unravel whether and how land-use intensities, associated disturbance levels or other local or regional influences drive ecological processes. KW - Agro-ecosystems KW - Biodiversity exploratories KW - Grassland management KW - Land-use impacts KW - Livestock density KW - Meadows KW - Nitrogen KW - Pastures Y1 - 2012 U6 - https://doi.org/10.1016/j.baae.2012.04.001 SN - 1439-1791 VL - 13 IS - 3 SP - 207 EP - 220 PB - Elsevier CY - Jena ER -