An Introduction And Case History Review Of Active Magnetic Bearings.

LecturePg. 121-126The concept of magnetic levitation is not a new one and can be easily traced back to the 1800s [1). It is only recently, however, that the congruous technologies of electronic control systems, power electronics, and magnetic materials have begun to merge to make the magnetic suspension device a viable product. A brief overview is presented of an active magnetic bearing technology [2]. The required systems engineering interface with the machine designer is discussed. Finally, case histories of various turbomachinery in North America presently operating on magnetic bearings are reviewed

characterization of determinants with an agent-based land use model

Wood is a limited resource which is exposed to a continuously growing global demand not least because of a politically fostered bioenergy use. One approach to master the challenge to sustainably meet this increasing wood demand is short rotation forestry (SRF). However, SRF is only gradually evolving and it is not fully understood which determinants hamper its expansion. This study provides theoretical insights into economic and environmental determinants of an SRF expansion and their interplay. This assessment requires the incorporation of farmers' decision-making based on an explicit investment appraisal. Therefore, we use an agent-based model to depict the decision- making of profit-maximizing farmers facing the choice between SRF, the cultivation of conventional annual agricultural crops and abstaining from cultivation (fallow land). The land use decisions are influenced by general economic determinants, such as market prices for wood and annual crops, and by site-dependent determinants, such as the environmental site quality. We found that the willingness to pay for SRF-based products and for annual crops most strongly influences the coverage of SRF in the landscape. SRF will in most cases be established on sites with low productivity. However, a decrease in the willingness to pay for annual crops will lead to a reallocation of SRF plantations to sites with higher productivity. Furthermore, our model results indicate that the impact of the distance to processing plants on farmers' decisions strongly depends on general economic determinants and the given spatial structure of the underlying natural landscape. Analysing the relative importance of different determinants of an SRF expansion, this study gives insights into the approach of using SRF to sustainably meet the growing wood demand. Moreover, these insights are taken as a starting point for the design of effective government interventions to promote SRF

Eurokrise, Energiewende, Konjunkturabkühlung: Ende des deutschen Jobwunders?

Welche Determinanten sind für das »deutsche Jobwunder« verantwortlich? Dieter Hundt, Bundesvereinigung der Deutschen Arbeitgeberverbände, sieht hinter dem Erfolg das verantwortliche Handeln der Tarifpartner, die Nutzung von Arbeitszeitkonten und richtige politische Entscheidungen etwa beim Kurzarbeitergeld. Dies zeige, dass die Tarifautonomie in Deutschland selbst unter extremen Bedingungen gut funktioniert. Frank-Jürgen Weise, Bundesagentur für Arbeit, Nürnberg, geht davon aus, dass es auch 2012 noch eine positive Entwicklung am Arbeitsmarkt geben wird und die Arbeitslosenzahl unter der Marke von 3 Millionen bleibt. Die gute Arbeitsmarktentwicklung lässt sich nach Ansicht von Hagen Lesch, Institut der deutschen Wirtschaft Köln, auf drei Einflüsse zurückführen: auf das Horten von Arbeitskräften während der Krise, auf eine moderate Lohnpolitik und auf die Arbeitsmarktreformen der Jahre 2003 bis 2005. Wolfgang Lechthaler, Institut für Weltwirtschaft, und Christian Merkl, Universität Erlangen-Nürnberg, erwarten, unter der Bedingung einer glaubwürdigen Haushaltskonsolidierung in Südeuropa bei gleichzeitiger Reduktion der Leistungsbilanzdefizite, nur moderate rezessive Schocks für Deutschland. Der deutsche Arbeitsmarkt verfüge über die Voraussetzungen, um einen sanften Abschwung zu absorbieren.Arbeitsmarkt, Arbeitsmarktflexibilität, Deutschland

Induced pluripotent stem cells and cerebral organoids from the critically endangered Sumatran rhinoceros

Less than 80 Sumatran rhinos (SR, Dicerorhinus sumatrensis) are left on earth. Habitat loss and limited breeding possibilities are the greatest threats to the species and lead to a continuous population decline. To stop the erosion of genetic diversity, reintroduction of genetic material is indispensable. However, as the propagation rate of captive breeding is far too low, innovative technologies have to be developed. Induced pluripotent stem cells (iPSCs) are a powerful tool to fight extinction. They give rise to each cell within the body including gametes and provide a unique modality to preserve genetic material across time. Additionally, they enable studying species-specific developmental processes. Here, we generate iPSCs from the last male Malaysian SR Kertam, who died in 2019, and characterize them comprehensively. Differentiation in cells of the three germ layers and cerebral organoids demonstrate their high quality and great potential for supporting the rescue of this critically endangered species

A novel reverse transduction adenoviral array for the functional analysis of shRNA libraries

<p>Abstract</p> <p>Background</p> <p>The identification of novel drug targets by assessing gene functions is most conveniently achieved by high-throughput loss-of-function RNA interference screening. There is a growing need to employ primary cells in such screenings, since they reflect the physiological situation more closely than transformed cell lines do. Highly miniaturized and parallelized approaches as exemplified by reverse transfection or transduction arrays meet these requirements, hence we verified the applicability of an adenoviral microarray for the elucidation of gene functions in primary cells.</p> <p>Results</p> <p>Here, we present microarrays of infectious adenoviruses encoding short hairpin RNA (shRNA) as a new tool for gene function analysis. As an example to demonstrate its application, we chose shRNAs directed against seven selected human protein kinases, and we have performed quantitative analysis of phenotypical responses in primary human umbilical vein cells (HUVEC). These microarrays enabled us to infect the target cells in a parallelized and miniaturized procedure without significant cross-contamination: Viruses were reversibly immobilized in spots in such a way that the seeded cells were confined to the area of the viral spots, thus simplifying the subsequent addressing of genetically modified cells for analysis. Computer-assisted image analysis of fluorescence images was applied to analyze the cellular response after shRNA expression. Both the expression level of knock-down target proteins as well as the functional output as measured by caspase 3 activity and DNA fractionation (TUNEL) were quantified.</p> <p>Conclusion</p> <p>We have developed an adenoviral microarray technique suitable for miniaturized and parallelized analysis of gene function. The practicability of this technique was demonstrated by the analysis of several kinases involved in the activation of programmed cell death, both in tumor cells and in primary cells.</p

Molecular characterization of hematopoietic stem cells after in vitro amplification on biomimetic 3D PDMS cell culture scaffolds

Hematopoietic stem cell (HSC) transplantation is successfully applied since the late 1950s. However, its efficacy can be impaired by insufficient numbers of donor HSCs. A promising strategy to overcome this hurdle is the use of an advanced ex vivo culture system that supports the proliferation and, at the same time, maintains the pluripotency of HSCs. Therefore, we have developed artificial 3D bone marrow-like scaffolds made of polydimethylsiloxane (PDMS) that model the natural HSC niche in vitro. These 3D PDMS scaffolds in combination with an optimized HSC culture medium allow the amplification of high numbers of undifferentiated HSCs. After 14 days in vitro cell culture, we performed transcriptome and proteome analysis. Ingenuity pathway analysis indicated that the 3D PDMS cell culture scaffolds altered PI3K/AKT/mTOR pathways and activated SREBP, HIF1α and FOXO signaling, leading to metabolic adaptations, as judged by ELISA, Western blot and metabolic flux analysis. These molecular signaling pathways can promote the expansion of HSCs and are involved in the maintenance of their pluripotency. Thus, we have shown that the 3D PDMS scaffolds activate key molecular signaling pathways to amplify the numbers of undifferentiated HSCs ex vivo effectively

MatriGrid® based biological morphologies: tools for 3D cell culturing

Recent trends in 3D cell culturing has placed organotypic tissue models at another level. Now, not only is the microenvironment at the cynosure of this research, but rather, microscopic geometrical parameters are also decisive for mimicking a tissue model. Over the years, technologies such as micromachining, 3D printing, and hydrogels are making the foundation of this field. However, mimicking the topography of a particular tissue-relevant substrate can be achieved relatively simply with so-called template or morphology transfer techniques. Over the last 15 years, in one such research venture, we have been investigating a micro thermoforming technique as a facile tool for generating bioinspired topographies. We call them MatriGrid ® s. In this research account, we summarize our learning outcome from this technique in terms of the influence of 3D micro morphologies on different cell cultures that we have tested in our laboratory. An integral part of this research is the evolution of unavoidable aspects such as possible label-free sensing and fluidic automatization. The development in the research field is also documented in this account