119 research outputs found
A critical evaluation of network and pathway based classifiers for outcome prediction in breast cancer
Recently, several classifiers that combine primary tumor data, like gene
expression data, and secondary data sources, such as protein-protein
interaction networks, have been proposed for predicting outcome in breast
cancer. In these approaches, new composite features are typically constructed
by aggregating the expression levels of several genes. The secondary data
sources are employed to guide this aggregation. Although many studies claim
that these approaches improve classification performance over single gene
classifiers, the gain in performance is difficult to assess. This stems mainly
from the fact that different breast cancer data sets and validation procedures
are employed to assess the performance. Here we address these issues by
employing a large cohort of six breast cancer data sets as benchmark set and by
performing an unbiased evaluation of the classification accuracies of the
different approaches. Contrary to previous claims, we find that composite
feature classifiers do not outperform simple single gene classifiers. We
investigate the effect of (1) the number of selected features; (2) the specific
gene set from which features are selected; (3) the size of the training set and
(4) the heterogeneity of the data set on the performance of composite feature
and single gene classifiers. Strikingly, we find that randomization of
secondary data sources, which destroys all biological information in these
sources, does not result in a deterioration in performance of composite feature
classifiers. Finally, we show that when a proper correction for gene set size
is performed, the stability of single gene sets is similar to the stability of
composite feature sets. Based on these results there is currently no reason to
prefer prognostic classifiers based on composite features over single gene
classifiers for predicting outcome in breast cancer
Modes of Foreign Entry under Asymmetric Information about Potential Technology Spillovers
This paper studies the effect of technology spillovers on the entry decision of a multinational enterprise into a foreign market. Two alternative entry modes for a foreign direct investment are considered: Greenfield investment versus acquisition. We find that with quantity competition a spillover makes acquisitions less attractive, while with price competition acquisitions become more attractive. Asymmetric information about potential spillovers always reduces the number of
acquisitions independently of whether the host country or the entrant has private information. Interestingly, we find that asymmetric information always hurts the entrant, while it sometimes is in favor of the host country
An overview of progress in electrolytes for secondary zinc-air batteries and other storage systems based on zinc
The revived interest and research on the development of novel energy storage systems with exceptional inherent
safety, environmentally benign and low cost for integration in large scale electricity grid and electric
vehicles is now driven by the global energy policies. Within various technical challenges yet to be resolved
and despite extensive studies, the low cycle life of the zinc anode is still hindering the implementation of
rechargeable zinc batteries at industrial scale. This review presents an extensive overview of electrolytes for
rechargeable zinc batteries in relation to the anode issues which are closely affected by the electrolyte nature.
Widely studied aqueous electrolytes, from alkaline to acidic pH, as well as non-aqueous systems including
polymeric and room temperature ionic liquids are reported. References from early rechargeable Zn-air research
to recent results on novel Zn hybrid systems have been analyzed. The ambition is to identify the challenges
of the electrolyte system and to compile the proposed improvements and solutions. Ultimately, all the
technologies based on zinc, including the more recently proposed novel zinc hybrid batteries combining the
strong points of lithium-ion, redox-flow and metal-air systems, can benefit from this compilation in order to
improve secondary zinc based batteries performance.Basque Country University
(ZABALDUZ2012 program), and the Basque Country Government
(Project: CIC energiGUNÉ16 of the ELKARTEK program) and the
European Commission through the project ZAS: “Zinc Air Secondary
innovative nanotech based batteries for efficient energy storage”
(Grant Agreement 646186
Discovery of a novel tumour metastasis-promoting gene, NVM-1
We have previously reported that over-expression of a panel of 119 genes correlates with the metastatic potential of pancreatic carcinoma cells. We sought to identify and functionally characterize candidate tumour metastasis promoting genes among this library using a secondary phenotype-assisted screen. Here we report the discovery of the metastasis-promoting function of a hitherto not characterized gene located on chromosome 14 (ORF138), which we have named 'novel metastasis-promoting gene 1' (NVM-1). The NVM-1 transcript is extensively alternatively spliced, is expressed endogenously in a number of different tissues, and is strongly over-expressed at the protein level in a variety of human tumour types. Importantly, NVM-1 expression stimulates the migratory and invasive behaviour of tumour cells and promotes metastasis formation in experimental animals in vivo. Up-regulation of FMNL2 and MT1E and down-regulation of TIMP4 and MHC-I is observed as a consequence of NVM-1 expression. Together these data identify NVM-1 as a gene that is functionally involved in tumour metastasis, and suggest that NVM-1 may constitute a promising therapeutic target for inhibition of tumour metastasis
Dichotome Differenzen und antirassistische Praxis
Die Autoren untersuchen Konzept und Methoden der US-amerikanischen Antirassismus-Trainerin Jane Elliott. Dabei hinterfragen sie, ob die zuvor genannte Einschätzung der Trainerin zu antirassistischen Lernzielen zu teilen ist und ob die vorgeschlagenen Mittel geeignet sind, diese zu erreichen. „Zuvor geht es um einen wichtigen Unterschied interkultureller und antirassistischer Konzepte: Beide beanspruchen, geeignete Mittel gegen rassistische Diskriminierung bereitzustellen, allerdings haben sie einen unterschiedlichen Differenz-Begriff, was Konsequenzen für die jeweilige Praxis hat. Gleichzeitig – so wird deutlich – scheinen einige antirassistische Konzepte eine dichotome Differenzstruktur zu konstruieren, die ebenfalls problematisch ist. Zum Schluss fragen (… die Autoren), wie geeignete antirassistische Konzepte im Bereich pädagogischer Arbeitsfelder aussehen könnten.“ (DIPF/ ssch
9 Schimpfen als Krankheit – Das Phänomen der Koprolalie bei Patienten mit Tourette-Syndrom
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