Volkswagen Foundation

About: Volkswagen Foundation is a nonprofit organization based out in Hanover, Germany. It is known for research contribution in the topics: Aluminide & Coating. The organization has 22 authors who have published 18 publications receiving 789 citations. The organization is also known as: VolkswagenStiftung.

Transforming growth factor-beta1 is a negative modulator of adult neurogenesis.

Abstract: Transforming growth factor (TGF)-beta1 has multiple functions in the adult central nervous system (CNS). It modulates inflammatory responses in the CNS and controls proliferation of microglia and astrocytes. In the diseased brain, TGF-beta1 expression is upregulated and, depending on the cellular context, its activity can be beneficial or detrimental regarding regeneration. We focus on the role of TGF-beta1 in adult neural stem cell biology and neurogenesis. In adult neural stem and progenitor cell cultures and after intracerebroventricular infusion, TGF-beta1 induced a long-lasting inhibition of neural stem and progenitor cell proliferation and a reduction in neurogenesis. In vitro, although TGF-beta1 specifically arrested neural stem and progenitor cells in the G0/1 phase of the cell cycle, it did not affect the self-renewal capacity and the differentiation fate of these cells. Also, in vivo, TGF-beta1 did not influence the differentiation fate of newly generated cells as shown by bromo-deoxyuridine incorporation experiments. Based on these data, we suggest that TGF-beta1 is an important signaling molecule involved in the control of neural stem and progenitor cell proliferation in the CNS. This might have potential implications for neurogenesis in a variety of TGF-beta1-associated CNS diseases and pathologic conditions.

Human Wild-Type α-Synuclein Impairs Neurogenesis

Abstract: Neurodegenerative diseases classified as synucleinopathies are characterized by alpha-synuclein inclusions. In these disorders, alpha-synuclein accumulates within glial or neuronal cells in the brain including regions of adult neurogenesis. We hypothesized a pathophysiological role for alpha-synuclein in newly generated cells of the adult brain and in this study examined regions of neurogenesis in adult mice overexpressing human wild-type alpha-synuclein under the control of the platelet-derived growth factor promoter. The number of proliferating cells and the fate of newly generated cells were analyzed in the olfactory bulb system and in the hippocampal dentate gyrus. There were no effects on proliferation detectable; however, significantly less neurogenesis and fewer neurons were observed in the olfactory bulb as well as in the hippocampus of adult human alpha-synuclein mice compared to control littermates. This effect was almost exclusively due to diminished survival of neuronal precursors in the target regions of neurogenesis. Our data imply that the finely tuned equilibrium of neuronal cell birth and death in neurogenic regions may be altered in human alpha-synuclein-overexpressing mice. We hypothesize that reduced adult neurogenesis in the olfactory bulb may contribute to olfactory deficits in neurodegenerative disorders associated with alpha-synuclein inclusions.

Signatures of human regulatory T cells: an encounter with old friends and new players

Abstract: Background Naturally occurring CD4+CD25+ regulatory T cells (TReg) are involved in the control of autoimmune diseases, transplantation tolerance, and anti-tumor immunity. Thus far, genomic studies on TReg cells were restricted to murine systems, and requirements for their development, maintenance, and mode of action in humans are poorly defined.

Ecological restoration as a real-world experiment: designing robust implementation strategies in an urban environment

Abstract: The concept of real-world experiments is a framework to understand environmental design projects under real world conditions. Contrary to laboratory experiments that are generally thought to exclude the public, real-world experiments involve combinations of social and natural factors. In this paper the theory of real-world experiments is applied to the fieldwork of ecological restoration. The case discussed here is an ecological design process at Montrose Point, a peninsula built on landfill in Lake Michigan on the North Side of Chicago. It illustrates how, in the practice of ecological restoration, the idea of experiment can be understood as being built on processes of recursive learning that include different parts of the wider society and nature. The paper outlines a concept of robust implementation strategies in which public involvement is a pivotal part of a more encompassing activity of ecological practice. This is undertaken to aim at a better understanding of learning processes taking place in nat...

Oxidation-resistant aluminide coatings on γ-TiAl

Abstract: The long-term application of TiAl alloys based on the γ-phase at temperatures above 750–800°C requires suitable surface coatings to provide the needed oxidation resistance. Without a coating, these alloys, containing large amounts of titanium, suffer from rapid oxidation attack at elevated temperatures. The pack-cementation coating process was used to aluminize the surface region of a Ti–50 at.% Al alloy to TiAl3, the most promising, oxidation-resistant phase in the Ti–Al system. The isothermal oxidation behavior of the coated alloy was studied in the temperature range 800–1000°C in air for up to 300 hr. The aluminide coating greatly improves the oxidation resistance of γ-TiAl, forming a protective alumina scale. The rapid aluminum interdiffusion between the TiAl3 coating and the γ-TiAl substrate determined the effective life of the coating. In addition, the oxidation behavior of the TiAl2 phase formed by interdiffusion of the coating system was studied by oxidation of cross sections.