173 research outputs found
Funktionsweise und Replikationstil europäischer Exchange Traded Funds auf Aktienindices
Exchange Traded Funds (ETF) were established in Europe in 2000 and have grown to a size of over 200 bn US$. Some issuers use a full replication strategy while others prefer a swap based approach. The ETF are dealt parallelly in the primary and in the secondary market, as new ETFs can be created at any time. Therefore, the market is very liquid with small ask bid spreads. The fees are considerably lower compared to active managed fonds. For liquid share indices both strategies can replicate the index convincingly. In the EUROSTOXX the ETF can outperform the Index due to dividend and tax optimization. This was not possible for the Dax. For illiquid large indices (MSCI Emerging Markets), there was a considerable difference between the monthly returns of the index compared to the ETFs. Both strategies have counterparty risk. The full replication uses security lending to enhance the performance. The synthetic strategy can have losses up to 10% if the swap partner defaults
Funktionsweise und Replikationstil europäischer Exchange Traded Funds auf Aktienindices
Exchange Traded Funds (ETF) were established in Europe in 2000 and have grown to a size of over 200 bn US$. Some issuers use a full replication strategy while others prefer a swap based approach. The ETF are dealt parallelly in the primary and in the secondary market, as new ETFs can be created at any time. Therefore, the market is very liquid with small ask bid spreads. The fees are considerably lower compared to active managed fonds. For liquid share indices both strategies can replicate the index convincingly. In the EUROSTOXX the ETF can outperform the Index due to dividend and tax optimization. This was not possible for the Dax. For illiquid large indices (MSCI Emerging Markets), there was a considerable difference between the monthly returns of the index compared to the ETFs. Both strategies have counterparty risk. The full replication uses security lending to enhance the performance. The synthetic strategy can have losses up to 10% if the swap partner defaults. --ETF,Exchange Traded Funds,Full Replication,Swap Replication,ETF Performance,ETF Risk
Regulation of the cytosolic stress response
The cytosolic stress response, also known as the heat-shock response (HSR), is one of the major defense mechanisms activated by cells to maintain the integrity of the cellular proteome under proteotoxic environmental conditions. It is characterized by the increased synthesis of heat-shock proteins (Hsps), mainly molecular chaperones and proteases which prevent the aggregation of misfolded proteins and mediate their refolding or degradation. It is generally accepted that the induction of the HSR is coordinated by the heat-shock transcription factor 1 (HSF1). However, many mechanistic aspects of the HSF1 regulation remain unclear.
In the present study, a genome-wide RNA interference screen was combined with an extensive biochemical analysis and quantitative proteomics to better understand the regulation of the HSR upon thermal stress. In the screening experiments novel positive and negative modulators of the stress response were identified, including proteins involved in chromatin remodeling, transcription, mRNA splicing, DNA damage repair, and proteolytic degradation. The diversity of the identified regulators suggests that induction and attenuation of the HSR integrate signals from different cellular pathways and are rather multi-factorial processes than single gene/protein events. The modulator proteins are localized in multiple cellular compartments with the majority having their primary location in the nucleus. A protein-protein interaction analysis revealed a HSR regulatory network, with chromatin modifiers and nuclear protein quality control components occupying hub positions. These observations are supported by quantitative proteomics experiments, which showed specific stress-induced reorganizations of the nuclear proteome, including the transient accumulation of chaperones and proteasomal subunits.
The histone acetyltransferase EP300 was shown to specifically control the cellular level of HSF1 by stabilizing it against proteasomal turnover under normal conditions. Moreover, the ubiquitin-proteasome system (UPS) was found to participate in the attenuation of the HSR by degrading stress-activated, hyperphosphorylated HSF1. Since HSF1 competes with stress-denatured proteins for access to the proteasome, the extent of cellular protein damage modulates the rate of HSR attenuation.
In addition to thermal stress, various other proteotoxic stresses are known to induce the HSR such as the proteasome inhibitor MG132 and the triterpenoid celastrol, which activates HSF1 by an unknown mechanism. Therefore, the networks regulating HSF1 activation upon thermal stress, proteasome inhibition and celastrol treatment were compared in this study. Whereas there is a large overlap between the sets of regulatory factors activated after heat stress and proteasomal impairment, HSF1 activation after celastrol treatment seems to bypass the HSR regulatory network to a large extent. Nevertheless, comparison of the regulatory networks under different proteotoxic conditions revealed a set of HSR core components, including factors involved in chromatin remodeling, DNA damage repair, RNA transport, transcription, and ion transport. The various cellular functions and localizations of these core components reinforce the multifaceted nature of the HSR regulation.
The results obtained in this study can help to identify potential targets for the pharmacologic manipulation of the HSR in the treatment of aggregate deposition diseases and cancer
Rethinking Hybrid Teaching: The Hybrid Rhombus Model as an Approach to Understanding Hybrid Settings
[EN] After extended periods of remote-only teaching at university, lecturers tried to come back to lecture halls. Due to restrictions not all students could participate on-site. Therefore, hybrid teaching models proliferated. To reflect the transformative effects on teaching practice, we conducted focus groups with lecturers and found that didactic models aimed at capturing dynamics of the in-situ learning experience do not provide sufficient understanding of the bifurcated nature of hybrid teaching. The hybrid rhombus model is an approach to conceptual understanding of the newly developed situation of teaching in a hybrid way. This paper gives a brief description of the model description and the empirical background, to contribute to the debate of hybrid teaching in relation to digital or on-site teaching.Handle-Pfeiffer, D.; Winter, C.; Löw, C.; Hackl, C. (2022). Rethinking Hybrid Teaching: The Hybrid Rhombus Model as an Approach to Understanding Hybrid Settings. En 8th International Conference on Higher Education Advances (HEAd'22). Editorial Universitat Politècnica de València. 1367-1375. https://doi.org/10.4995/HEAd22.2022.146021367137
Pictures in Your Mind: Using Interactive Gesture-Controlled Reliefs to Explore Art
Tactile reliefs offer many benefits over the more classic raised line drawings or tactile diagrams, as depth, 3D shape, and surface textures are directly perceivable. Although often created for blind and visually impaired (BVI) people, a wider range of people may benefit from such multimodal material. However, some reliefs are still difficult to understand without proper guidance or accompanying verbal descriptions, hindering autonomous exploration.
In this work, we present a gesture-controlled interactive audio guide (IAG) based on recent low-cost depth cameras that can be operated directly with the hands on relief surfaces during tactile exploration. The interactively explorable, location-dependent verbal and captioned descriptions promise rapid tactile accessibility to 2.5D spatial information in a home or education setting, to online resources, or as a kiosk installation at public places.
We present a working prototype, discuss design decisions, and present the results of two evaluation studies: the first with 13 BVI test users and the second follow-up study with 14 test users across a wide range of people with differences and difficulties associated with perception, memory, cognition, and communication. The participant-led research method of this latter study prompted new, significant and innovative developments
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