Refine
Year of publication
Document Type
- Article (29885)
- Part of Periodical (11829)
- Book (8221)
- Doctoral Thesis (5576)
- Part of a Book (3622)
- Working Paper (3369)
- Review (2857)
- Contribution to a Periodical (2278)
- Preprint (1799)
- Report (1545)
Language
- German (41965)
- English (28277)
- French (1067)
- Portuguese (722)
- Multiple languages (304)
- Croatian (302)
- Spanish (301)
- Italian (193)
- mis (174)
- Turkish (148)
Is part of the Bibliography
- no (73778) (remove)
Keywords
- Deutsch (1037)
- Literatur (798)
- taxonomy (737)
- Deutschland (541)
- Rezension (491)
- new species (437)
- Frankfurt <Main> / Universität (341)
- Rezeption (320)
- Geschichte (291)
- Linguistik (268)
Institute
- Medizin (7333)
- Präsidium (5082)
- Physik (4108)
- Extern (2661)
- Wirtschaftswissenschaften (2656)
- Gesellschaftswissenschaften (2366)
- Biowissenschaften (2101)
- Biochemie und Chemie (1941)
- Center for Financial Studies (CFS) (1608)
- Informatik (1576)
Der Koalitionsvertrag 2021 sieht eine generationengerechte Absicherung des Rentenniveaus durch eine teilweise aus Haushaltsmitteln finanzierte Kapitaldeckung vor. Um dieses Ziel zu verwirklichen, wird hier die Einführung einer Generationenrente ab Geburt vorgeschlagen. Dabei wird aus Haushaltsmitteln ein Betrag von € 5.000 für jedes Neugeborene nach Grundsätzen des professionellen Anlagemanagements am globalen Kapitalmarkt angelegt. Konzeptionell soll sich diese Generationenrente am Modell der Basisrente(§10 Abs. 1 Nr. 2 b EStG) orientieren, d.h. die akkumulierten Gelder sind weder beleihbar, vererbbar noch übertragbar und können frühestens ab Alter 63 zugunsten einer lebenslangen Monatsrente verwendet werden. Unsere Berechnungen zeigen, dass durch die hier vorgeschlagene Generationenrente unabhängig vom Verlauf der individuellen Erwerbsbiographie, Altersarmut für die vom demographischen Wandel besonders betroffenen zukünftigen Generationen vermieden wird.
Real estate is an important asset, but as a direct investment subject to several difficulties. Shares of public open end funds or of real estate stock corporations represent a possible way for an investor to avoid these problems. The focus of this paper is the analysis of inflation risk of European real estate securities. An overview of the institutional frameworks regarding these companies is given. The returns of real estate securities in France, Germany, Switzerland and the United Kingdom are examined for the period 1980:1-1998:12. Besides the classical Fama/Schwert-approach, shortfall risk measurements have been used. In this context, transaction costs in particular have been taken into account.
The focus of this article is the analysis of the inflation risk of European real estate securities. Following both a causal and a final understanding of risk, the analysis is twofold. First, to examine the causal influence of inflation on short- and long-term asset returns, different regression approaches are employed based on the methodology of Fama and Schwert (1977). Hedging capacities against expected inflation are found only for German open-end funds. Secondly, different shortfall risk measures are used to study whether an investment in European real estate securities protects against a negative real return at the end of a given investment period.
The purpose of this paper is to compare three different index construction methodologies of commercial property investments. We examine for different European countries (i) appraisal-based indices and methods of „unsmoothing“ the corresponding return series, (ii) indices that trace average ex-post transaction prices over time, and (iii) indices based on Real Estate Investment Trust share prices.
This article presents an overview of the contemporary German insurance market, its structure, players, and development trends. First, brief information about the history of the insurance industry in Germany is provided. Second, the contemporary market is analyzed in terms of its legal and economic structure, with statistics on the number of companies, insurance density and penetration, the role of insurers in the capital markets, premiums split, and main market players and their market shares. Furthermore, the three biggest insurance lines—life, health, and property and casualty—are considered in more detail, such as product range, country specifics, and insurance and investment results. A section on regulation outlines its implementation in the insurance sector, offering information on the underlying legislative basis, supervisory body, technical procedures, expected developments, and sources of more detailed information.
Versicherungsunternehmen haben bei der Auswahl ihrer Vermögensanlagen die gesetzlichen Restriktionen des Versicherungsaufsichtsgesetzes einzuhalten. Neben einer strukturierten Darstellung der zahlreichen Regulierungstatbestände werden aus Sicht der Finanzierungstheorie sowie den empirischen Verhältnissen an den Kapitalmärkten die im VAG enthaltenen Rahmenbedingungen einer kritischen Bewertung unterzogen.
Dynamics of life course family transitions in Germany: exploring patterns, process and relationships
(2023)
This paper explores dynamics of family life events in Germany using discrete time event history analysis based on SOEP data. We find that higher educational attainment, better income level, and marriage emerge as salient protective factors mitigating the risk of mortality; better education also reduces the likelihood of first marriage whereas, lower educational attainment, protracted period, and presence of children act as protective factors against divorce. Our key finding shows that disparity in mean life expectancies between individuals from low- and high-income brackets is observed to be 9 years among males and 6 years among females, thereby illustrating the mortality inequality attributed to income disparities. Our estimates show that West Germans have low risk of death, less likelihood of first marriage, and they have a high risk of divorce and remarriage compared to East Germans.
As past research suggest, currency exposure risk is a main source of overall risk of international diversified portfolios. Thus, controlling the currency risk is an important instrument for controlling and improving investment performance of international investments. This study examines the effectiveness of controlling the currency risk for international diversified mixed asset portfolios via different hedge tools. Several hedging strategies, using currency forwards and currency options, were evaluated and compared with each other. Therefore, the stock and bond markets of the, United Kingdom, Germany, Japan, Switzerland, and the U.S, in the time period of January 1985 till December 2002, are considered. This is done form the point of view of a German investor. Due to highly skewed return distributions of options, the application of the traditional mean-variance framework for portfolio optimization is doubtful when options are considered. To account for this problem, a mean-LPM model is employed. Currency trends are also taken into account to check for the general dependence of time trends of currency movements and the relative potential gains of risk controlling strategies.
In recent years, several neuronal differentiation protocols were published that circumvent the requirement of embryoid body (EB) formation under serum-deprivation and simplified medium conditions. But a neuronal default model to establish an approach that works efficiently for all pluripotent cells and neuronal precursors is still lacking. Whether such a default neural mechanism exist and how this is implemented across a broad spectrum of cell source, is addressed in several studies and still controversially discussed. It was proposed that the default neuronal fate is initiated in the absence of extrinsic signals and is achieved by eliminating extracellular inhibitors of neuroectodermal fate and suppressing cell-cell signalling through limited cell density. Previous studies reported that ESC and ECC grown at low density and in absence of exogenous factors or feeder layers die within 24 h but acquire a neural identity as indicated by expression of the neural marker Nestin. Thus, this application is not suitable for generating neural cultures. Furthermore, it was reported that P19 cells survive and express neuroectodermal marker genes in serum-free DMEM/F12 medium containing transferrin, insulin, and selenite, although no neurites were identified.
Based on this background, in this study, a novel approach to induce neuronal differentiation in vitro was developed that implements a nutrient-poor environment, which, in contrast to previous studies, ensures the survival of neuronally differentiated cells over a long period of time and allows normal formation of neurites. Neither the formation of free-floating aggregates nor supplementation of growth factors or known inducers was required to establish a reliable neuronal differentiation protocol. A simple medium, consisting of DMEM/F12+N2 that was highly diluted in salt solution, was sufficient to drive a fast neuronal differentiation in monolayer cultures. Serum deprivation and strong dilution of DMEM/F12+N2 medium cause a nutrient-poor environment in which the influence of growth factors and inducers is minimized. This medium creates a metabolically defined environment that is presumably free of extrinsic signals that prevent the decision of neuronal fate. Analysis of the medium components discovered no actual inducer. Hence, it was suggested that the metabolic composition of the medium exclusively covers specific cell requirements of neurons, therefore ensures their survival, and drives the switch from pluripotent cells to neurons. The self-developed method was established by usage of the murine embryonal carcinoma cell line P19 and could be transferred to murine ESC. Consequently, the method could provide a feasible protocol for a generally valid neuronal default model.
The established protocol provides several advantages such as the possibility to generate stable pure neuronal cultures by a fast, simple, and highly reproducible one-step induction under defined medium conditions with a minimum of exogen effectors. The method is characterised by clear and steady medium conditions that makes the investigation of specific cell requirements during differentiation accessible. It is therefore expected to be a useful tool to investigate the molecular basis of neuronal differentiation as well as for high throughput screenings. The phenotype of mature postmitotic neurons was arising within one week and cultures were shown to stay stable at least for three weeks. The neuronal identity was confirmed by expression of neuronal markers through immunofluorescence staining and mass spectrometry analysis. Furthermore, increased levels of axon markers were detected in early neuronal differentiation and functionality of the synapses of the P19-derived neurons was ascertained by detection of calcium activity. Axonal laser ablation, immediately followed by fast regrowth of connections in the neuronal network, revealed a strong regeneration potential under the given conditions. Furthermore, the generated neurons showed a morphologically distinct phenotype and the formation of neural rosettes. Immunofluorescence staining demonstrated the generation of pure and homogeneous neuronal cultures, free of glial cells.
Retinoic acid (RA) plays an essential role in cell signalling during embryogenesis and efficiently induces neuronal differentiation in vitro in a concentration dependent manner. Neither retinol nor retinoic acid was included in any of the components of the self-prepared medium in this work. However, I observed, dependence on RARβ- and/or RARγ-regulated RA signalling in serum-free monolayer cultures. Nevertheless, neuronal differentiation in serum-free monolayer cultures was assumed to be RARα-independent because (i) RARα was slightly downregulated after neuronal induction, (ii) the truncated RARα of the RAC65 mutant had no effect on induction efficiency, and (iii) a pan-RAR inhibitor suppressed neuronal differentiation. In contrast to serum-free monolayer cultures, the truncated RARα prevented neuronal differentiation by application of the conventional protocol where cells are grown in free floating cell aggregates in serum-containing medium. Proteome analysis of P19 cells, treated by the self-developed differentiation protocol over five days showed increased levels of cellular RA binding proteins that mediate the cellular RA transport and are involved in canonical as well as non-canonical RA signalling.
...
Objective: Current literature debates the role of newly developed three-dimensional (3D) Exoscopes in the daily routine of neurosurgical practice. So far, only a small number of cadaver lab studies or case reports have examined the novel Aesculap Aeos Three-Dimensional Robotic Digital Microscope. This study aims to evaluate the grade of satisfaction and intraoperative handling of this novel system in neurosurgery. Methods: Nineteen neurosurgical procedures (12 cranial, 6 spinal and 1 peripheral nerve) performed over 9 weeks using the Aeos were analyzed. Ten neurosurgeons of varying levels of training were included after undergoing device instruction and training. Following every surgery, a questionnaire consisting of 43 items concerning intraoperative handling was completed. The questionnaires were analyzed using descriptive statistics. Results: No intraoperative complications occurred. Surgical satisfaction was ranked high (78.95%). In total, 84.21% evaluated surgical ergonomics as satisfactory, while 78.95% of the surgeons would like to use this system frequently. Image quality, independent working zoom function and depth of field were perceived as suboptimal by several neurosurgeons. Conclusion: The use of Aeos is feasible and safe in microsurgical procedures, and surgical satisfaction was ranked high among most neurosurgeons in our study. The system might offer advanced ergonomic conditions in comparison to conventional ocular-based microscopes.