21 research outputs found
Geospatial dimensions of the renewable energy transition — The importance of prioritisation
The renewable energy transition is a priority for many researchers, policy makers, and political leaders because it is projected to stop the dependence of economic growth on increasing fossil fuel use and thus curtail climate change. This study examines how expert judgments affect development decisions to enable the renewable energy transition. Geospatial Multi-Criteria Decision Analyses (MCDA) are frequently used to select offshore wind energy (OWE) sites, however, they are often weak and/or often rely on limited judgement. The Analytical Hierarchy Process is used here with 25 diverse experts to assess the variability in priorities for OWE siting criteria. A geospatial MCDA is implemented using experts' individual priorities, aggregated weights and Monte Carlo simulations. Case study results reveal large variations in expert opinions and bias strongly affecting MCDAs weighted by single decision-makers. A group-decision approach is proposed to strengthen consent for OWE, underpinning the renewable energy transition
Plectranthus zeylanicus: A rich source of secondary metabolites with antimicrobial, disinfectant and anti-inflammatory activities
Plectranthus zeylanicus Benth is used in Sri Lankan folk medicine as a remedy for inflammatory conditions and microbial infections. Our previous investigations revealed potent 5-lipoxygenase (5-LO) inhibitory activity in lipophilic extracts of this plant, supporting its anti-inflammatory potential. In-depth studies on the antimicrobial activity have not been conducted and the bioactive ingredients remained elusive. As a continuation of our previous work, the present investigation was undertaken to evaluate the antimicrobial activity of different extracts of P. zeylanicus and to isolate and characterize bioactive secondary metabolites. Different organic extracts of this plant were analyzed for their antibacterial activity, and the most active extract, i.e., dichloromethane extract, was subjected to bioactivity-guided fractionation, which led to the isolation of 7α-acetoxy-6β-hydroxyroyleanone. This compound displayed strong antibacterial activity against methicillin-resistant Staphylococcus aureus with a minimum inhibitory concentration of 62.5 µg/mL, and its disinfectant capacity was comparable to the potency of a commercial disinfectant. Moreover, 7α-acetoxy-6β-hydroxyroyleanone inhibits 5-LO with IC50 values of 1.3 and 5.1 µg/mL in cell-free and cell-based assays, respectively. These findings rationalize the ethnopharmacological use of P. zeylanicus as antimicrobial and anti-inflammatory remedy
Schumpeter and Venture Finance: Radical Theorist, Broke Investor and Enigmatic Teacher
Schumpeter's relation to venture finance constitutes a fascinating yet so far unacknowledged chapter of his biography and financial history. Presenting new historical evidence and pointing out connections that have so far escaped attention, we first discuss Schumpeter's venture theory of money and banking, then his personal history as a broke investor in Vienna, and finally his influence on the emerging venture industry during his later years at Harvard. We show how the theoretical vision inspired his failed effort as a venture investor in the 1920s, and provided a powerful intellectual frame for the later development of venture finance in the 1940s
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A Multisite Preregistered Paradigmatic Test of the Ego-Depletion Effect
We conducted a preregistered multilaboratory project (k = 36; N = 3,531) to assess the size and robustness of ego-depletion effects using a novel replication method, termed the paradigmatic replication approach. Each laboratory implemented one of two procedures that was intended to manipulate self-control and tested performance on a subsequent measure of self-control. Confirmatory tests found a nonsignificant result (d = 0.06). Confirmatory Bayesian meta-analyses using an informed-prior hypothesis (δ = 0.30, SD = 0.15) found that the data were 4 times more likely under the null than the alternative hypothesis. Hence, preregistered analyses did not find evidence for a depletion effect. Exploratory analyses on the full sample (i.e., ignoring exclusion criteria) found a statistically significant effect (d = 0.08); Bayesian analyses showed that the data were about equally likely under the null and informed-prior hypotheses. Exploratory moderator tests suggested that the depletion effect was larger for participants who reported more fatigue but was not moderated by trait self-control, willpower beliefs, or action orientation
MOEMS EC-QCL for real-time identification of chemical compounds
Real-time MIR spectroscopic sensing using a MOEMS based external cavity quantum cascade laser is demonstrated by transmission measurements on polystyrene absorber sheets as well as reflectance measurements on active pharmaceutical ingredients
Miniaturisierte Laserlichtquelle für Infrarotspektroskopie
Breitbandig durchstimmbare Infrarotstrahlung im mittleren Wellenlängenbereich von etwa 3 bis 10 μm bzw. 1000 bis3200 Wellenzahlen ist ein hochinteressantes Mittel zur spektroskopischen Untersuchung gasförmiger, flüssiger oderfester Stoffe und Gemische. In diesem Beitrag wird eine weit durchstimmbare Infrarotlichtquelle auf Basis eines Quantenkaskadenlasers(QCL) und eines mikro-opto-elektro-mechanischen (MOEMS) Gitters vorgestellt. Dieses Konzeptvereint Vorteile breitbandiger Quellen mit Vorteilen kohärenter Laserquellen in einem miniaturisierten Aufbau. Als mögliche Anwendungen werden aktuell berührungslose und zerstörungsfreie Echtzeit-Identifikation explosiver Substanzen sowie online und inline Detektion von Öl-Kontaminationen in Wasser untersucht und entwickelt
Lipophilic extracts of Leucas zeylanica, a multi-purpose medicinal plant in the tropics, inhibit key enzymes involved in inflammation and gout
Ethnopharmacological relevance Leucas zeylanica (L.) W.T. Aiton is a popular, multi-purpose medicinal plant in Sri Lanka but the pharmacological potential and the chemical profile have not been systematically investigated to understand and rationalize the reported ethnobotanical significance. Aim of the study The present study was undertaken to scientifically validate the traditional usage of this plant for the treatment of inflammatory conditions, gout and microbial infections. Inhibition of 5-lipoxygenase (5-LO), microsomal prostaglandin E2 synthase (mPGES)−1 and xanthine oxidase (XO) by different extracts of L. zeylanica was investigated to determine the anti-inflammatory and anti-gout activity, respectively. The antibacterial and antifungal activities were also studied and the relevant constituents in the bioactive extracts were tentatively identified. Materials and Methods Cell-free and/or cell-based assays were employed in order to investigate the effects of the extracts against the activity of human 5-LO, mPGES-1 and XO as well as to assess antioxidant properties. The antibacterial activity of the extracts was determined by the broth micro-dilution method against Gram positive and Gram negative bacteria including methicillin-resistant Staphylococcus aureus while the agar dilution method was employed to determine the anti-Candida activity. Gas chromatography coupled to mass spectrometric (GC-MS) analysis enabled the characterization of secondary metabolites in the extracts. Results A dichloromethane extract of L. zeylanica efficiently inhibited 5-LO activity in stimulated human neutrophils (IC50 = 5.5 µg/mL) and isolated human 5-LO and mPGES-1 (IC50 = 2.2 and 0.4 µg/mL). Potent inhibition of XO was observed by the same extract (IC50 = 47.5 μg/mL), which is the first report of XO-inhibitory activity of a Sri Lankan medicinal plant. Interestingly, significant radical scavenging activity was not observed by this extract. Only the n-hexane extract exhibited antibacterial activity against Staphylococcus aureus and Staphylococcus saprophyticus with a MIC of 250 µg/mL while the anti-Candida activity was moderate. GC-MS analysis revealed the presence of phytosterols, fatty acids, sesquiterpenes, diterpenes and several other types of secondary metabolites. Potent inhibition of 5-LO, mPGES-1 and XO rationalizes the ethnopharmacological use of L. zeylanica as anti-inflammatory and anti-gout remedy. Interestingly, the antimicrobial activities were not prominent, despite its wide utility as an antimicrobial medication
The anti-inflammatory and antimicrobial potential of selected ethnomedicinal plants from Sri Lanka
Traditional folk medicine in Sri Lanka is mostly based on plants and plant-derived products, however, many of these medicinal plant species are scientifically unexplored. Here, we evaluated the anti-inflammatory and antimicrobial potency of 28 different extracts prepared from seven popular medicinal plant species employed in Sri Lanka. The extracts were subjected to cell-based and cell-free assays of 5-lipoxygenase (5-LO), microsomal prostaglandin E-2 synthase (mPGES)-1, and nitric oxide (NO) scavenging activity. Moreover, antibacterial and disinfectant activities were assessed. Characterization of secondary metabolites was achieved by gas chromatography coupled to mass spectrometric (GC-MS) analysis. n-Hexane- and dichloromethane-based extracts of Garcinia cambogia efficiently suppressed 5-LO activity in human neutrophils (IC50 = 0.92 and 1.39 mu g/mL), and potently inhibited isolated human 5-LO (IC50 = 0.15 and 0.16 mu g/mL) and mPGES-1 (IC50 = 0.29 and 0.49 mu g/mL). Lipophilic extracts of Pothos scandens displayed potent inhibition of mPGES-1 only. A methanolic extract of Ophiorrhiza mungos caused significant NO scavenging activity. The lipophilic extracts of G. cambogia exhibited prominent antibacterial and disinfectant activities, and GC-MS analysis revealed the presence of fatty acids, sesquiterpenes and other types of secondary metabolites. Together, our results suggest the prospective utilization of G. cambogia as disinfective agent with potent anti-inflammatory properties