Max Planck Society

About: Max Planck Society is a nonprofit organization based out in Munich, Germany. It is known for research contribution in the topics: Galaxy & Population. The organization has 148289 authors who have published 406224 publications receiving 19522268 citations. The organization is also known as: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V. & MPG.

Gas chromatography mass spectrometry–based metabolite profiling in plants

Abstract: The concept of metabolite profiling has been around for decades, but technical innovations are now enabling it to be carried out on a large scale with respect to the number of both metabolites measured and experiments carried out. Here we provide a detailed protocol for gas chromatography mass spectrometry (GC-MS)-based metabolite profiling that offers a good balance of sensitivity and reliability, being considerably more sensitive than NMR and more robust than liquid chromatography-linked mass spectrometry. We summarize all steps from collecting plant material and sample handling to derivatization procedures, instrumentation settings and evaluating the resultant chromatograms. We also define the contribution of GC-MS-based metabolite profiling to the fields of diagnostics, gene annotation and systems biology. Using the protocol described here facilitates routine determination of the relative levels of 300-500 analytes of polar and nonpolar extracts in approximately 400 experimental samples per week per machine.

The Impact of Prior Entrepreneurial Exposure on Perceptions of New Venture Feasibility and Desirability

Abstract: Tests Shapero's intentions-based model of new venture initiation. This model assumes that the intent to start a new business is the result of perceived desirability, feasibility, and the individual's propensity to act upon opportunities. Entrepreneurial intention is defined as the commitment to starting a new business. An understanding of these intentions is important as it helps to identify key characteristics for new firms. The decision to start a new business requires the perception that starting a new business is credible and some type of precipitating event. Data used in the analysis were collected from 126 upper-division university business students – 75 males and 51 females. The data itself show perception measures and propensity to act have a significant correlation with entrepreneurial intentions. Breadth of experience has a strong correlation to perceived feasibility while positiveness of experience is strongly correlated with perceived desirability. Results demonstrate support for Shapero's model and further indicate that measures of prior entrepreneurial exposure can be added. Implications of this analysis for researchers, training entrepreneurs, and practitioners are discussed. (SRD)

The ninth data release of the sloan digital sky survey: First spectroscopic data from the sdss-iii baryon oscillation spectroscopic survey

Abstract: The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z ~ 0.52), 102,100 new quasar spectra (median z ~ 2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T eff -0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SEGUE-2. The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the APOGEE along with another year of data from BOSS, followed by the final SDSS-III data release in 2014 December.

The EMT-activator ZEB1 promotes tumorigenicity by repressing stemness-inhibiting microRNAs

Abstract: Invasion and metastasis of carcinomas is promoted by the activation of the embryonic 'epithelial to mesenchymal transition' (EMT) program, which triggers cellular mobility and subsequent dissemination of tumour cells. We recently showed that the EMT-activator ZEB1 (zinc finger E-box binding homeobox 1) is a crucial promoter of metastasis and demonstrated that ZEB1 inhibits expression of the microRNA-200 (miR-200) family, whose members are strong inducers of epithelial differentiation. Here, we report that ZEB1 not only promotes tumour cell dissemination, but is also necessary for the tumour-initiating capacity of pancreatic and colorectal cancer cells. We show that ZEB1 represses expression of stemness-inhibiting miR-203 and that candidate targets of miR-200 family members are also stem cell factors, such as Sox2 and Klf4. Moreover, miR-200c, miR-203 and miR-183 cooperate to suppress expression of stem cell factors in cancer cells and mouse embryonic stem (ES) cells, as demonstrated for the polycomb repressor Bmi1. We propose that ZEB1 links EMT-activation and stemness-maintenance by suppressing stemness-inhibiting microRNAs (miRNAs) and thereby is a promoter of mobile, migrating cancer stem cells. Thus, targeting the ZEB1-miR-200 feedback loop might form the basis of a promising treatment for fatal tumours, such as pancreatic cancer.