Combined effects of temperature and biodiversity on phytoplankton communities

Biodiversität besitzt das Potential, negative Effekte externer Umweltveränderungen durch gesteigerte Produktion und Ressourcennutzungskapazität und die daraus resultierende Erhöhung der Resilienz und Resistenz eines Ökosystems zu regulieren. In Folge des global stattfindenden Klimawandels ist die Diversität von Phytoplanktongemeinschaften vor allem in Gewässern kleiner bis mittlerer Größe (Teiche, seichte Seen, kleine Bäche, Flussauen) jedoch stark gefährdet, unter anderem aufgrund steigender Wassertemperaturen und verstärkt auftretender extremer Hitzeereignisse. In dieser Studie wurden die interaktiven Effekte von Temperatur und Artenvielfalt beziehungsweise Diversität auf das Wachstum, die Nährstoffdynamik, sowie die Artenzusammensetzung von Phytoplankton untersucht. Unter kontrollierten Laborbedingungen wurden Monokulturen von 15 Süßwasser-Phytoplanktontaxa der funktionellen Gruppen Chlorophyceae (Grünalgen), Cyanophyceae (Cyanobakterien) und Bacillariophyceae (Kieselalgen), sowie 25 gemischte Gemeinschaften unterschiedlicher Artenanzahl (2, 3, 6, 9, und 12 Arten) und Artenzusammensetzung zwei Wochen lang an die drei Temperaturen von 12°C, 18°C und 24°C adaptiert und im Anschluss über 7 Tage hinweg täglichen 7-stündigen Temperaturerhöhungen (Peaks) um +4°C ausgesetzt um die Einwirkung extremer Hitzeereignisse zu simulieren. Wachstumsraten, molare C:P-Verhältnisse und die Ressourcennutzungseffizienz des Phytoplankton wurden als Funktion der Temperatur beziehungsweise der Diversität bestimmt. Höhere Artenzahlen hatten einen stimulierenden Effekt auf alle gemessenen Parameter und auf allen Temperaturstufen, vor allem nach den Temperatur-Peaks. Letztere führten andererseits zu einer Verringerung der Diversität. Höhere Temperaturen stellten sich außerdem als vorteilhaft für Cyanobakterien heraus. Diese Studie konnte einen wichtigen, zweifach negativen Effekt erhöhter Wassertemperaturen auf Phytoplanktongemeinschaften aufzeigen: die Verringerung der Diversität und Artenanzahl einerseits, sowie andererseits bzw. als Folge davon, die Verringerung des Potentials höher diverser Gemeinschaften, extreme Hitzeereignisse in sensiblen aquatischen Systemen wirkungsvoll abzupuffern.Biodiversity has been shown to serve as an insurance to regulate responses to environmental changes by enhancing productivity and resource use efficiency and thus the resistance and resilience of ecosystems. However, as a consequence to climate change, phytoplankton diversity is at risk due to increasing water temperatures and extreme heat events, especially in small- to medium-scale water bodies such as ponds, shallow lakes, little streams, or river floodplain backwaters. In this study, we investigated the combined effects of temperature and species diversity on phytoplankton growth performance, nutrient dynamics, and community composition. In a controlled lab experiment, monocultures of 15 freshwater phytoplankton taxa from the functional groups Chlorophyceae, Cyanophyceae, and Bacillariophyceae, as well as 25 mixed communities of different species richness (2, 3, 6, 9, and 12 species) and taxa composition were adapted to 12°C, 18°C, and 24°C, and thereafter exposed to short-term daily temperature peaks of +4°C to simulate extreme heat events. Growth rates, molar C:P ratios, and resource use efficiency were determined as a function of temperature and diversity, respectively. Increased species richness had a positive, enhancing effect on all parameters measured at all temperature levels, most strongly after short-term temperature peaks. However, temperature peaks had an overall negative effect on diversity and higher temperatures increasingly selected for cyanobacteria as the most heat-tolerant experimental group. This study revealed a significant double negative impact of increased water temperatures by diminishing phytoplankton diversity and, as a consequence, minimizing the potential to mitigate extreme heat events in sensitive aquatic systems

Ökologische Konzepte in der europäischen Politik

Die Umweltbranche boomt und ökologische Innovationen sind in aller Munde. Doch finden diese theoretischen Konzepte und innovativen Technologien wirklich Eingang in die politische Praxis? Und wie können diese Ansatzpunkte zur politischen Ausgestaltung einer nachhaltigen Entwicklung beitragen

Fibulin-5 mutations link inherited neuropathies, age-related macular degeneration and hyperelastic skin

To identify the disease-causing gene responsible for an autosomal dominantly inherited Charcot-Marie-Tooth neuropathy subtype in a family excluded for mutations in the common Charcot-Marie-Tooth genes, we used array-based sequence capture to simultaneously analyse the disease-linked protein coding exome at chromosome 14q32. A missense mutation in fibulin-5, encoding a widely expressed constituent of the extracellular matrix that has an essential role in elastic fibre assembly and has been shown to cause cutis laxa, was detected as the only novel non-synonymous sequence variant within the disease interval. Screening of 112 index probands with unclassified Charcot-Marie-Tooth neuropathies detected two further fibulin-5 missense mutations in two families with Charcot-Marie-Tooth disease and hyperextensible skin. Since fibulin-5 mutations have been described in patients with age-related macular degeneration, an additional 300 probands with exudative age-related macular degeneration were included in this study. Two further fibulin-5 missense mutations were identified in six patients. A mild to severe peripheral neuropathy was detected in the majority of patients with age-related macular degeneration carrying mutations in fibulin-5. This study identifies fibulin-5 as a gene involved in Charcot-Marie-Tooth neuropathies and reveals heterozygous fibulin-5 mutations in 2% of our patients with age-related macular degeneration. Furthermore, it adumbrates a new syndrome by linking concurrent pathologic alterations affecting peripheral nerves, eyes and skin to mutations in the fibulin-5 gen

Autophagy Protects From Uremic Vascular Media Calcification

Chronic kidney disease and diabetes mellitus are associated with extensive media calcification, which leads to increased cardiovascular morbidity and mortality. Here, we investigated the role of autophagy in the pathogenesis of uremic vascular media calcification. DBA/2 mice were fed with high-phosphate diet (HPD) in order to cause vascular calcification. DBA/2 mice on standard chow diet were used as control. In parallel, autophagy and its response to rapamycin, 3-methyladenine (3-MA), and bafilomycin were studied in an in vitro model using mouse vascular smooth muscle cells (MOVAS). DBA/2 mice on HPD developed severe vascular media calcification, which is mirrored in vitro by culturing MOVAS under calcifying conditions. Both, in vitro and in vivo, autophagy significantly increased in MOVAS under calcifying conditions and in aortas of HPD mice, respectively. Histologically, autophagy was located to the aortic Tunica media, but also vascular endothelial cells, and was found to continuously increase during HPD treatment. 3-MA as well as bafilomycin blocked autophagy in MOVAS and increased calcification. Vice versa, rapamycin treatment further increased autophagy and resulted in a significant decrease of vascular calcification in vitro and in vivo. Rapamycin reduced Runx2 transcription levels in aortas and MOVAS to control levels, whereas it increased α-smooth muscle actin and Sm22α transcription in MOVAS to control levels. Furthermore, rapamycin-treated HPD mice survived significantly longer compared to HPD controls. These findings indicate that autophagy is an endogenous response of vascular smooth muscle cells (VSMC) to protect from calcification in uremia. Induction of autophagy by rapamycin protects cells and mice from uremic media calcification possibly by inhibiting osteogenic transdifferentiation of VSMC

SNP array-based whole genome homozygosity mapping as the first step to a molecular diagnosis in patients with Charcot-Marie-Tooth disease

Considerable non-allelic heterogeneity for autosomal recessively inherited Charcot-Marie-Tooth (ARCMT) disease has challenged molecular testing and often requires a large amount of work in terms of DNA sequencing and data interpretation or remains unpractical. This study tested the value of SNP array-based whole-genome homozygosity mapping as a first step in the molecular genetic diagnosis of sporadic or ARCMT in patients from inbred families or outbred populations with the ancestors originating from the same geographic area. Using 10 K 2.0 and 250 K Nsp Affymetrix SNP arrays, 15 (63%) of 24 CMT patients received an accurate genetic diagnosis. We used our Java-based script eHoPASA CMT—easy Homozygosity Profiling of SNP arrays for CMT patients to display the location of homozygous regions and their extent of marker count and base-pairs throughout the whole genome. CMT4C was the most common genetic subtype with mutations detected in SH3TC2, one (p.E632Kfs13X) appearing to be a novel founder mutation. A sporadic patient with severe CMT was homozygous for the c.250G > C (p.G84R) HSPB1 mutation which has previously been reported to cause autosomal dominant dHMN. Two distantly related CMT1 patients with early disease onset were found to carry a novel homozygous mutation in MFN2 (p.N131S). We conclude that SNP array-based homozygosity mapping is a fast, powerful, and economic tool to guide molecular genetic testing in ARCMT and in selected sporadic CMT patients

Personaleinführung von Führungskräften in der Sozialwirtschaft : Eine quantitative Befragung von Führungskräften sozialwirtschaftlicher Organisationen in Österreich

Die vorliegende Masterarbeit beschäftigt sich mit der Personaleinführung von Führungskräften in sozialwirtschaftlichen Situationen in Österreich. Ziel ist es, die Phase des beruflichen Einstiegs in die Führungsfunktion aus Sicht der Führungskräfte abzubilden, Herausforderungen und Hürden, welche sich in diesem Zeitraum ergeben aufzuzeigen und unterstützende Maßnahmen, welche seitens der Organisation zum Einsatz kommen, zu identifizieren. Auf Grundlage einer theoretischen Auseinandersetzung mit den Konzepten der Personaleinführung und des bestehenden Forschungsstandes, wurde im Sinne eines quantitativen Zugangs eine Mixed-Mode Befragung mit 110 Führungskräften, welche in sozialwirtschaftlichen Organisationen beschäftigt sind, durchgeführt. Die Ergebnisse dieser Studie sollen Handlungsanregungen für sozialwirtschaftliche Organisationen, im speziellen für die Personalabteilungen, darstellen und ein möglichen Veränderungsbedarf in diesem Bereich aufzeigen.The following master thesis evolves around the staff introduction of executive roles in social economy situations in Austria. The goal of this paper is to display this introduction phase in the point of view of the executive roles themselves. It is therefore aiming towards recognizing challenges and problems of that stage and to finding solutions to these from an organizational point of view. Based on a theoretical interaction with the concepts of the staff introduction and the current state of research, a mixed mode questionnaire was created, using a quantitative access with 110 leading managers which are working in social economy organizations. The results of this study should provide suggestions for institutions of that kind and specifically it should help to visualize the possible requirements of change for their human resources departments.vorgelegt von: Julia SchabhüttlWien, FH Campus Wien, Masterarb., 2020(VLID)491704

Bilanzanalyse deutscher Energiekonzerne in Hinblick auf die Auswirkungen der Energiewende

In den letzten 20 Jahren veränderte sich die Energiewirtschaft in Kontinentaleuropa dramatisch schnell. Zuerst durch die Liberalisierung des Strommarktes, initiiert von der Europäischen Union, später durch den politischen Willen, erneuerbare Energien in Deutschland stärker zu fördern.Am 29. März 2000 wurde die erste Fassung des Erneuerbare-Energien-Gesetzes in Deutschland beschlossen. Dabei sollten (noch) unrentable Erneuerbare-Energien-Kraftwerke gefördert werden, damit sich diese am liberalisierten Markt durchsetzen können und somit Investitionsanreize geschafften werden. Die Folgen dieser Förderpolitik führten jedoch zu starken Verwerfungen in der Branche. Energiekonzerne mit einem hohen Anteil an konventionellen Kraftwerken kommen nun verstärkt unter Druck.In den ersten Kapiteln werden überblicksmäßig die Vorgänge der Liberalisierung des deutschen Strommarktes dargestellt. Anschließend wird die Förderpolitik der erneuerbaren Energien und deren Auswirkung auf den Börsenpreis für Strom betrachtet. Darauf folgend wird die Veränderung der Rentabilität von konventionellen Kraftwerken untersucht.Ziel dieser Arbeit ist es, die Auswirkungen der Energiewende auf die großen vier deutschen Stromerzeuger (E.ON, EnBW, RWE, Vattenfall) zu analysieren. Als theoretisches Instrument wird dabei die Geschäftsberichtsanalyse gewählt. Die Geschäftsberichtsanalyse wird in erfolgswirtschaftliche, finanzwirtschaftliche und marktwertorientierte Jahresabschlussanalyse eingeteilt. Der Schwerpunkt liegt hier in der Betrachtung der Auswirkungen der hohen Abschreibungen auf konventionelle Kraftwerke, verursacht durch die eingebrochenen Großhandelspreise für Strom.Weiter wird ein Ausblick über die zukünftigen Entwicklungen der Energiewirtschaft gegeben. Dabei werden die Herausforderungen, welche den Energiekonzernen in den nächsten Jahren bevorstehen, aufgezeigt und analysiert.The liberalization of the European energy markets and the governmental promotion of renewable energy generation led to disruptive tendencies in the energy sector over the last 15 years.On the 29th of March in 2000, the first version of the renewable-energy-policy was agreed by the German government. Therefore, renewable power plants, which have higher costs than fossil-fuelled power plants, received a financial promotion. After that, the investments in renewables increased dramatically. As a result, the price for power on the energy exchange plummeted and conventional power plants are now less profitable than before. This causes immense pressure on energy companies with a high amount of conventional power plants in their portfolio.The first chapters give an overview about the liberalization of the German energy market followed by a roundup of policies on subsidies for renewable energy and their impact on the exchange prices for wholesale power. The next chapters show the influence of the lower wholesale prices on the business conduct of the energy sector.The aim of this paper is to analyse the effect of the energy turnaround in Germany on the four big utility companies (E.ON, EnBW, RWE, Vattenfall) in the country. As a theoretical tool, a balance sheet analysis has been chosen. The balance sheet analysis is sectioned into a profitability, financial and market based view on the annual financial statements for the period between 2011 and 2015. The focus here should be the inspection of the influence of the high depreciations on conventional power plants for the energy companies, caused by the decreased prices for power on the wholesale market.At the end of this paper, a prospect of future progresses in the energy sector will be given and challenges for energy companies for the next years should be identified.Thomas SchabhüttlAbweichender Titel laut Übersetzung des Verfassers/der VerfasserinZusammenfassungen in Deutsch und EnglischKarl-Franzens-Universität Graz, Masterarbeit, 2017(VLID)224618

Phytoplankton responses to temperature increases are constrained by abiotic conditions and community composition

Effects of temperature changes on phytoplankton communities seem to be highly context-specific, but few studies have analyzed whether this context specificity depends on differences in the abiotic conditions or in species composition between studies. We present an experiment that allows disentangling the contribution of abiotic and biotic differences in shaping the response to two aspects of temperature change: permanent increase of mean temperature versus pulse disturbance in form of a heat wave. We used natural communities from six different sites of a floodplain system as well as artificially mixed communities from laboratory cultures and grew both, artificial and natural communities, in water from the six different floodplain lakes (sites). All 12 contexts (2 communities × 6 sites) were first exposed to three different temperature levels (12, 18, 24 °C, respectively) and afterward to temperature pulses (4 °C increase for 7 h day(-1)). Temperature-dependent changes in biomass and community composition depended on the initial composition of phytoplankton communities. Abiotic conditions had a major effect on biomass of phytoplankton communities exposed to different temperature conditions, however, the effect of biotic and abiotic conditions together was even more pronounced. Additionally, phytoplankton community responses to pulse temperature effects depended on the warming history. By disentangling abiotic and biotic effects, our study shows that temperature-dependent effects on phytoplankton communities depend on both, biotic and abiotic constraints