Cavity optoelectromechanical regenerative amplification

Cavity optoelectromechanical regenerative amplification is demonstrated. An optical cavity enhances mechanical transduction, allowing sensitive measurement even for heavy oscillators. A 27.3 MHz mechanical mode of a microtoroid was linewidth narrowed to 6.6\pm1.4 mHz, 30 times smaller than previously achieved with radiation pressure driving in such a system. These results may have applications in areas such as ultrasensitive optomechanical mass spectroscopy

Expression of ECM proteins fibulin-1 and -2 in acute and chronic liver disease and in cultured rat liver cells

Fibulin-2 has previously been considered as a marker to distinguish rat liver myofibroblasts from hepatic stellate cells. The function of other fibulins in acute or chronic liver damage has not yet been investigated. The aim of this study has been to evaluate the expression of fibulin-1 and -2 in models of rat liver injury and in human liver cirrhosis. Their cellular sources have also been investigated. In normal rat liver, fibulin-1 and -2 were both mainly present in the portal field. Fibulin-1-coding transcripts were detected in total RNA of normal rat liver, whereas fibulin-2 mRNA was only detected by sensitive, real-time quantitative polymerase chain reaction. In acute liver injury, the expression of fibulin-1 was significantly increased (17.23-fold after 48 h), whereas that of fibulin-2 was not modified. The expression of both fibulin-1 and -2 was increased in experimental rat liver cirrhosis (19.16- and 26.47-fold, respectively). At the cellular level, fibulin-1 was detectable in hepatocytes, “activated” hepatic stellate cells, and liver myofibroblasts (2.71-, 122.65-, and 469.48-fold over the expression in normal rat liver), whereas fibulin-2 was restricted to liver myofibroblasts and was regulated by transforming growth factor beta-1 (TGF-β1) in 2-day-old hepatocyte cultures and in liver myofibroblasts. Thus, fibulin-1 and -2 respond differentially to single and repeated damaging noxae, and their expression is differently present in liver cells. Expression of the fibulin-2 gene is regulated by TGF-β1 in liver myofibroblasts

Metabolic capabilities of microorganisms involved in and associated with the anaerobic oxidation of methane

In marine sediments the anaerobic oxidation of methane with sulfate as electron acceptor (AOM) is responsible for the removal of a major part of the greenhouse gas methane. AOM is performed by consortia of anaerobic methane-oxidizing archaea (ANME) and their specific partner bacteria. The physiology of these organisms is poorly understood, which is due to their slow growth with doubling times in the order of months and the phylogenetic diversity in natural and in vitro AOM enrichments. Here we study sediment-free long-term AOM enrichments that were cultivated from seep sediments sampled off the Italian Island Elba (20◦C; hereon called E20) and from hot vents of the Guaymas Basin, Gulf of California, cultivated at 37◦C (G37) or at 50◦C (G50). These enrichments were dominated by consortia of ANME-2 archaea and Seep-SRB2 partner bacteria (E20) or by ANME-1, forming consortia with Seep-SRB2 bacteria (G37) or with bacteria of the HotSeep-1 cluster (G50). We investigate lipid membrane compositions as possible factors for the different temperature affinities of the different ANME clades and show autotrophy as characteristic feature for both ANME clades and their partner bacteria. Although in the absence of additional substrates methane formation was not observed, methanogenesis from methylated substrates (methanol and methylamine) could be quickly stimulated in the E20 and the G37 enrichment. Responsible for methanogenesis are archaea from the genus Methanohalophilus and Methanococcoides, which are minor community members during AOM (1–7h of archaeal 16S rRNA gene amplicons). In the same two cultures also sulfur disproportionation could be quickly stimulated by addition of zero-valent colloidal sulfur. The isolated partner bacteria are likewise minor community members (1–9h of bacterial 16S rRNA gene amplicons), whereas the dominant partner bacteria (Seep-SRB1a, Seep-SRB2, or HotSeep-1) did not grow on elemental sulfur. Our results support a functioning of AOM as syntrophic interaction of obligate methanotrophic archaea that transfer non-molecular reducing equivalents (i.e., via direct interspecies electron transfer) to obligate sulfate-reducing partner bacteria. Additional katabolic processes in these enrichments but also in sulfate methane interfaces are likely performed by minor community members

Cavity Optomechanical Magnetometer

A cavity optomechanical magnetometer is demonstrated where the magnetic field induced expansion of a magnetostrictive material is transduced onto the physical structure of a highly compliant optical microresonator. The resulting motion is read out optically with ultra-high sensitivity. Detecting the magnetostrictive deformation of Terfenol-D with a toroidal whispering gallery mode (TWGM) resonator a peak sensitivity of 400 nT/Hz^.5 was achieved with theoretical modelling predicting that sensitivities of up to 500 fT/Hz^.5 may be possible. This chip-based magnetometer combines high-sensitivity and large dynamic range with small size and room temperature operation

Interferometric detection of mode splitting for whispering gallery mode biosensors

Sensors based on whispering gallery mode resonators can detect single nanoparticles and even single molecules. Particles attaching to the resonator induce a doublet in the transmission spectrum which provides a self-referenced detection signal. However, in practice this spectral feature is often obscured by the width of the resonance line which hides the doublet structure. This happens particularly in liquid environments that reduce the effective Q factor of the resonator. In this paper we demonstrate an interferometric set-up that allows the direct detection of the hidden doublet and thus provides a pathway for developing practical sensor applications.Comment: 9 page

Barriers and Ways Forward to Climate Risk Management Against Indirect Effects of Natural Disasters: A Case Study on Flood Risk in Austria

Natural disasters, such as floods, can have severe consequences, especially as economies are becoming ever more interlinked and complex so that the cascading effects of disasters can amplify direct impacts. These trends are expected to continue in the future due to climate change and changing socio-economic structures. It is therefore important to promote climate risk management strategies that also deal with indirect effects due to natural disaster events in a proactive manner. However, there is a lack of studies which investigate the agents involved in climate risk management geared towards the indirect effects of disasters and how these indirect effects are or can be dealt with. We address this gap via a detailed case study of the Austrian flood risk management apparatus. Based on a detailed stakeholder analysis, we compile a stakeholder map of those potentially involved in indirect flood risk management as well as the relationships (or the lack thereof) among them. We further discuss current and future indirect risk management strategies and corresponding implementation barriers. Finally, based on the results obtained from the stakeholder process, we discuss and suggest possible ways forward to overcome these barriers to enable proactive management strategies for indirect climate risks. We find that although indirect risks are being considered in the Austrian flood risk management, they are managed to a marginal degree. To remedy this, we call for increased efforts in data collection, modelling and awareness raising and the revision of current financial as well as institutional structures. Greater focus should be put on interdependencies within systems as well as the adoption of long-term visions for establishing more integrated climate risk management against indirect effects

Revealing the indirect risks of flood events: A multi-model assessment for Austria

Flood events and the associated damages trigger direct as well as indirect effects due to economy-wide linkages. Hence, flood events pose indirect risks to complex socioeconomic systems and their individual agents. Despite their increasing importance in the light of ongoing climate change impacts, such indirect risks are not well understood. Using a set of three different economy-wide models – an input output model, a computable general equilibrium (CGE) model and an agent-based model – we reveal and study indirect risks of flood events for the case of Austria. The three models are fed with high resolution data on sector-specific capital stock damages, which is a major improvement with respect to existing approaches in disaster and climate change impact assessment. We find that indirect risks are very high for most economic sectors and that only the minority of sectors can gain from flood events. Furthermore, on the side of private households we find that floods pose a risk in terms of unequal distributional effects, since capital rents tend to increase while wages tend to decrease in the aftermath of a flood, leading to a re-distribution of income from highto low-income households. The study thus offers highly relevant leverage points for indirect risk management options in Austria. The used methodologies can be transferred to other regions