Staatsfonds - neue Akteure an den Finanzmärkten?

Sovereign Wealth Funds (SWFs) have become active investors on the financial markets. This working paper meets the increasing thirst for information on the investment activities of Sovereign Wealth Funds, their legal environment and the implications on German stock listed corporations. Thus, this paper examines the history of, and reasons for establishing SWFs. Furthermore, concerns regarding transparency and investment activities of SWFs are discussed. The authors find no evidence for politicaly motivated investments or massive market intervention by SWFs. Furthermore, the authors propose that the newly established Santiago Principles will build up trust in the financial markets. The empirical part of the working paper analyzes the impact of SWFs on German stock listed corporations. Main findings of the survey include that corporations lack information on SWFs and disagree with the planned change of the Außenwirtschaftsgesetz. The Survey's results further indicate that participant corporations have no concerns about SWF investment activities. Only few SWFs were willing to participate in the survey and therefore information from the IMF was utilized to get an overview about the sector. --Sovereign wealth funds,Staatsfonds,Außenwirtschaftsgesetz,portfolioanalysis,monetary reserve,investment strategy,foreign exchange,transparency,Santiago principles

Case study of a European medium-range weather forecast bust

Nowadays even medium-range (~6 days) forecasts are mostly reliable but occasionally the quality of the forecasts collapses suddenly. During a collapse or a bust, the actual forecast is worse than a ‘forecast’ made by using climatological mean values. In this study sudden collapse of predictability will be investigated by using one example case from April 2011. OpenIFS NWP model and ERA-Interim reanalysis were used as primary tools. 13 deterministic forecasts with the best available initial conditions were run but one forecast initialized on the worst day is particularly concentrated on. One ensemble forecast of five members also initialized on the worst day is also investigated in this study. Output of OpenIFS was compared to ERA-Interim. Previous studies have shown that the reasons for European forecast busts can be found in North America. Therefore, the aim of this study is to determine if the incorrect representation of convection over North America lead to a forecast bust over Europe. Besides the main goal, this study discusses how the errors originating from North American convection lead to a forecast bust in Europe 6 days later and this study will also be looking for cause of the forecast bust from initial conditions of ensemble forecast. In this case the sudden collapse of predictability in Europe is caused by NWP models predicting change of weather regime wrong. Also OpenIFS predicts formation of a blocking high over Northern Europe although there are no signs of blocking in reanalysis. In Northern America, where the source of the error is, forecast of evolution of a cluster of thunderstorms fails so also convective forcing to large scale dynamics fails. The error grows and is transported to Europe by Rossby waves. Although none of the members of the ensemble forecast was able to forecast the weather properly in Europe, so much deviation was obtained in the outcomes that comparison of the initial conditions was meaningful. The most important finding was that deeper trough over the Rocky Mountains improves the forecast in Europe. This study was able to show evidence that misrepresented convection over North America caused the forecast to fail in Europe. Moreover, this study was able to clarify how the errors caused by misrepresented convection evolved and lead to the forecast bust in Europe. The error at the beginning of the forecast in North America grows so fast that it is unlikely that it would be due to model parameterizations but the initial conditions must contain errors. These failed forecast are difficult to avoid completely but the easiest way to reduce them is to improve quality of the observations in the Rocky mountains.Nykyaikana keskipitkätkin (~6 päivää) sääennusteet ovat pääosin luotettavia mutta toisinaan ennusteiden laatu romahtaa yhtäkkiä. Tällöin jopa ‘ennuste’, joka on tehty käyttäen ilmastollisia keskiarvoja on parempi kuin säämallin tuottama ennuste. Tässä tutkielmassa tarkastellaan tällaista yhtäkkistä sään ennustettavuuden romahdusta käyttäen esimerkkitapausta huhtikuulta 2011. Työkaluina käytettiin OpenIFS -säämallia ja ERA-Interim -uusanalyysiä. OpenIFS:llä ajettiin 13 determinististä ennustetta parhaista alkuarvoista mutta keskityttiin erityisesti yhteen ennusteeseen huonoimmalta aloituspäivältä. Lisäksi ajettiin myös yksi viiden jäsenen ryväsennuste ennustettavuudeltaan huonoimmalta päivältä. OpenIFS:n tuloksia verrattiin ERA-Interimiin. Aiemmat tutkimukset viittaavat siihen, että Euroopan sääennusteiden epäonnistumisen syyt löytyvät Pohjois-Amerikasta, joten tämän tutkimuksen päätarkoitus on selvittää, että johtaako huonosti mallinnettu konvektio Pohjois-Amerikassa 6 päivän sääennusteen epäonnistumiseen Euroopassa. Lisäksi tässä tutkimuksessa selvitetään, että miten huonosti mallinnettu konvektio johtaa tässä esimerkkitapauksessa Euroopan sääennusteiden epäonnistumiseen. Lisäksi epäonnistumisen syytä etsitään ryväsennusteen alkuarvoista. Tässä tapauksessa ennustettavuuden romahdus Euroopassa johtuu siitä, että säämallit ennakoivat säätyypin muutoksen väärin. Myös OpenIFS ennustaa sulkukorkeapaineen muodostumista, vaikka uusanalyysissä sitä ei näy. Virheen alkulähteillä Pohjois-Amerikassa voimakkaan ukkoskuuroryppään kehityksen ennustaminen menee pieleen, jolloin konvektiivinen pakote suuren mittakaavan dynamiikkaan menee pieleen. Syntynyt virhe kasvaa ja kulkeutuu Eurooppaan Rossby-aaltojen mukana. Vaikka valitusta ryväsennusteesta mikään jäsen ei kyennyt ennustamaan Euroopan säätilaa kunnolla, hajontaa saatiin silti sen verran aikaiseksi, että alkuarvojen vertailu oli mielekästä. Tärkein löydös oli, että syvempi yläsola Kalliovuorten yllä parantaa ennustetta Euroopassa. Tässä tutkimuksessa pystyttiin esittämään todisteita siitä, että Pohjois-Amerikan huonosti mallinnettu konvektio johti ennusteen epäonnistumiseen Euroopassa. Lisäksi kyettiin selvittämään, että miten konvektion ennustamisessa tapahtuvat virheet kehittyvät ja johtavat ennusteen epäonnistumiseen Euroopassa. Ennusteen virhe kasvaa ennusteen alussa Pohjois-Amerikassa niin nopeasti, että on epätodennäköistä, että se johtuisi mallin parametrisoinnista vaan alkuarvoissa täytyy olla virheitä. Tällaisia epäonnistuneita sääennusteita on vaikea täysin vältää mutta helpoin tapa vähentää niitä on parantaa säähavaintojen laatua Kalliovuorilla

Necessary conditions for algorithmic tuning of weather prediction models using OpenIFS as an example

Algorithmic model tuning is a promising approach to yield the best possible forecast performance of multi-scale multi-phase atmospheric models once the model structure is fixed. The problem is to what degree we can trust algorithmic model tuning. We approach the problem by studying the convergence of this process in a semi-realistic case. Let M (x, theta) denote the time evolution model, where x and theta are the initial state and the default model parameter vectors, respectively. A necessary condition for an algorithmic tuning process to converge is that theta is recovered when the tuning process is initialised with perturbed model parameters theta' and the default model forecasts are used as pseudo-observations. The aim here is to gauge which conditions are sufficient in a semi-realistic test setting to obtain reliable results and thus build confidence on the tuning in fully realistic cases. A large set of convergence tests is carried in semi-realistic cases by applying two different ensemble-based parameter estimation methods and the atmospheric forecast model of the Integrated Forecasting System (OpenIFS) model. The results are interpreted as general guidance for algorithmic model tuning, which we successfully tested in a more demanding case of simultaneous estimation of eight OpenIFS model parameters.Peer reviewe

Seuranta työkaluna porsastuotannon kehittämisessä

ei saatavill

Filter Likelihood as an Observation-Based Verification Metric in Ensemble Forecasting

In numerical weather prediction (NWP), ensemble forecasting aims to quantify the flow-dependent forecast uncertainty. The focus here is on observation-based verification of the reliability of ensemble forecasting systems. In particular, at short forecast lead times, forecast errors tend to be relatively small compared to observation errors and hence it is very important that the verification metric also accounts for observational uncertainties. This paper studies the so-called filter likelihood score which is deep-rooted in Bayesian estimation theory and fits naturally to the filtering setup of NWP. The filter likelihood score considers observation errors, ensemble mean skill, and ensemble spread in one metric. Importantly, it can be made multivariate and effortlessly expanded to simultaneous verification against all observation types through the observation operators contained in the parental data assimilation scheme. Here observations from the global radiosonde network and satellites (AMSU-A channel 5) are included in the verification of OpenIFS-based ensemble forecasts using different types of initial state perturbations. Our results show that the filter likelihood score is sensitive to the ensemble prediction system quality and compares consistently with other verification metrics such as the relationships between ensemble spread and ensemble mean forecast error, and Dawid-Sebastiani score. Our conclusion is that the filter likelihood score provides a very well-behaving verification metric, that can be made truly multivariate by including covariances, for ensemble prediction systems with a strong foundation in estimation theory.Peer reviewe

Ensemble prediction using a new dataset of ECMWF initial states - OpenEnsemble 1.0

Ensemble prediction is an indispensable tool in modern numerical weather prediction (NWP). Due to its complex data flow, global medium-range ensemble prediction has almost exclusively been carried out by operational weather agencies to date. Thus, it has been very hard for academia to contribute to this important branch of NWP research using realistic weather models. In order to open ensemble prediction research up to the wider research community, we have recreated all 50 + 1 operational IFS ensemble initial states for OpenIFS CY43R3. The dataset (Open Ensemble 1.0) is available for use under a Creative Commons licence and is downloadable from an https server. The dataset covers 1 year (December 2016 to November 2017) twice daily. Downloads in three model resolutions (T(L)159, T(L)399, and T(L)639) are available to cover different research needs. An open-source workflow manager, called OpenEPS, is presented here and used to launch ensemble forecast experiments from the perturbed initial conditions. The deterministic and probabilistic forecast skill of OpenIFS (cycle 40R1) using this new set of initial states is comprehensively evaluated. In addition, we present a case study of Typhoon Damrey from year 2017 to illustrate the new potential of being able to run ensemble forecasts outside of major global weather forecasting centres.Peer reviewe

Regulation of the Activity in the p53 Family Depends on the Organization of the Transactivation Domain.

Despite high sequence homology among the p53 family members, the regulation of their transactivation potential is based on strikingly different mechanisms. Previous studies revealed that the activity of TAp63α is regulated via an autoinhibitory mechanism that keeps inactive TAp63α in a dimeric conformation. While all p73 isoforms are constitutive tetramers, their basal activity is much lower compared with tetrameric TAp63. We show that the dimeric state of TAp63α not only reduces DNA binding affinity, but also suppresses interaction with the acetyltransferase p300. Exchange of the transactivation domains is sufficient to transfer the regulatory characteristics between p63 and p73. Structure determination of the transactivation domains of p63 and p73 in complex with the p300 Taz2 domain further revealed that, in contrast to p53 and p73, p63 has a single transactivation domain. Sequences essential for stabilizing the closed dimer of TAp63α have evolved into a second transactivation domain in p73 and p53.The research was funded by the DFG (DO 545/8 and DO 545/13), the Center for Biomolecular Magnetic Resonance (BMRZ), and the Cluster of Excellence Frankfurt (Macromolecular Complexes). M.T. was supported by a fellowship from the Fonds of the Chemical Industry

DARPins detect the formation of hetero-tetramers of p63 and p73 in epithelial tissues and in squamous cell carcinoma

The two p53 homologues p63 and p73 regulate transcriptional programs in epithelial tissues and several cell types in these tissues express both proteins. All members of the p53 family form tetramers in their active state through a dedicated oligomerization domain that structurally assembles as a dimer of dimers. The oligomerization domain of p63 and p73 share a high sequence identity, but the p53 oligomerization domain is more divergent and it lacks a functionally important C-terminal helix present in the other two family members. Based on these structural differences, p53 does not hetero-oligomerize with p63 or p73. In contrast, p63 and p73 form hetero-oligomers of all possible stoichiometries, with the hetero-tetramer built from a p63 dimer and a p73 dimer being thermodynamically more stable than the two homo-tetramers. This predicts that in cells expressing both proteins a p63$_{2}$/p73$_{2}$ hetero-tetramer is formed. So far, the tools to investigate the biological function of this hetero-tetramer have been missing. Here we report the generation and characterization of Designed Ankyrin Repeat Proteins (DARPins) that bind with high affinity and selectivity to the p63$_{2}$/p73$_{2}$ hetero-tetramer. Using these DARPins we were able to confirm experimentally the existence of this hetero-tetramer in epithelial mouse and human tissues and show that its level increases in squamous cell carcinoma

Was eine Data Governance für das Forschungsdatenmanagement leisten kann

In dem Fraunhofer-internen Projekt „Krisenmanagement und Resilienz – Corona“ (KResCo) wurden Maßnahmen gegen die Covid-19-Pandemie in verschiedenen Ländern sowie deren Wirksamkeit untersucht. Hierbei wurden viele Daten erzeugt und nachgenutzt, deren Management in einem eigenen Arbeitspaket gesteuert wurde. Hierzu wurde ein Data-Governance-Ansatz angewendet, im Rahmen dessen verschiedene strategische, rechtliche und operative Bausteine entwickelt und während des Projektverlaufs erprobt wurden. Der Artikel beschreibt diese Bausteine und und beurteilt deren Umsetzungsgad im Projekt anhand eines Reifegrad-Modells. Im Ergebnis zeigte sich, dass nicht alle Ziele der Data Governance im Projekt erreicht werden konnten, da keine ausreichende Akzeptanz bei den Forschenden aufgebaut werden konnte, so dass diese die Bausteine nicht im erforderlichen Umfang nutzten

Ultra-thin fluorocarbon foils optimise multiscale imaging of three-dimensional native and optically cleared specimens

In three-dimensional light microscopy, the heterogeneity of the optical density in a specimen ultimately limits the achievable penetration depth and hence the three-dimensional resolution. The most direct approach to reduce aberrations, improve the contrast and achieve an optimal resolution is to minimise the impact of changes of the refractive index along an optical path. Many implementations of light sheet fluorescence microscopy operate with a large chamber filled with an aqueous immersion medium and a further inner container with the specimen embedded in a possibly entirely different non-aqueous medium. In order to minimise the impact of the latter on the optical quality of the images, we use multi-facetted cuvettes fabricated from vacuum-formed ultra-thin fluorocarbon (FEP) foils. The ultra-thin FEP-foil cuvettes have a wall thickness of about 10–12 µm. They are impermeable to liquids, but not to gases, inert, durable, mechanically stable and flexible. Importantly, the usually fragile specimen can remain in the same cuvette from seeding to fixation, clearing and observation, without the need to remove or remount it during any of these steps. We confirm the improved imaging performance of ultra-thin FEP-foil cuvettes with excellent quality images of whole organs such us mouse oocytes, of thick tissue sections from mouse brain and kidney as well as of dense pancreas and liver organoid clusters. Our ultra-thin FEP-foil cuvettes outperform many other sample-mounting techniques in terms of a full separation of the specimen from the immersion medium, compatibility with aqueous and organic clearing media, quick specimen mounting without hydrogel embedding and their applicability for multiple-view imaging and automated image segmentation. Addit