4,496 research outputs found
A comparison of cost-benefit analysis of biomass and natural gas CHP projects in Denmark and the Netherlands
The authors are grateful for the funding provided by the Erasmus program for financing international collaboration and to the Edgar – Macredes project for funding part of the research time.We investigate what drives differences in the project appraisal of biomass and natural gas combined heat and power (CHP) projects in two countries with very similar energy profiles. This is of importance as the European Commission is assessing the potential scope of harmonizing renewable electricity support schemes post 2020. Concurrently, it is also promoting the use of cost benefit analysis (CBA) for transnational energy infrastructure projects. We use CBA to assess the same project proposal in Denmark and the Netherlands, following the respective country's guidelines. We find that especially the fuel costs and the valuation of emissions drive the differences. Furthermore, we establish that the sensitivity of the CBA results not only from policy differences in the countries, but also from differences in the methodology used.PostprintPeer reviewe
The systematic position of Plagiochila moritziana, P. trichostoma and P. deflexa based on ITS sequence variation of nuclear ribosomal DNA, morphology, and lipophilic secondary metabolites
According to phylogenetic analyses of nrDNA ITS1 and ITS2 sequences (including the 5.8S unit) the Neotropical Plagiochila moritziana, P. rutilans var. rutilans, P. rutilans var. standleyi, P. trichostoma (= P. permista, syn. nov.), and P. subtrinitensis form a monophyletic lineage and are placed in P. sect. Rutilantes; all five taxa lack a ca 20 base pair sequence that is present in all the taxa of the other Plagiochila sections investigated. The Central American P. subtrinitensis is treated as a synonym of the Hawaiian endemic P. deflexa. Plagiochila moritziana is excluded from sect. Fuscoluteae and reduced to a variety of P. rutilans; P. sect. Permistae is treated as a synonym of P. sect. Rutilantes. The sporophytes of P. trichostoma and P. deflexa are described for the first time. Fresh material of P. rutilans var. moritziana exhibits a distinct odor of peppermint caused by the presence of several menthane monoterpenoids, principally pulegone. The Central American P. rutilans var. standleyi is reported from Ecuador, new to South America. Lectotypes are designated for P. rutilans var. moritziana, P. subtrinitensis, and P. trichostoma
Analysis of Oct4-dependent transcriptional networks regulating self-renewal and pluripotency in human embryonic stem cells
The POU domain transcription factor OCT4 is a key regulator of pluripotency in the early mammalian embryo and is highly expressed in the inner cell mass of the blastocyst. Consistent with its essential role in maintaining pluripotency, Oct4 expression is rapidly downregulated during formation of the trophoblast lineage. To enhance our understanding of the molecular basis of this differentiation event in humans, we used a functional genomics approach involving RNA interference-mediated suppression of OCT4 function in a human ESC line and analysis of the resulting transcriptional profiles to identify OCT4-dependent genes in human cells. We detected altered expression of >1,000 genes, including targets regulated directly by OCT4 either positively (NANOG, SOX2, REX1, LEFTB, LEFTA/EBAF DPPA4, THY1, and TDGF1) or negatively (CDX2, EOMES, BMP4, TBX18, Brachyury [T], DKK1, HLX1, GATA6, ID2, and DLX5), as well as targets for the OCT4-associated stem cell regulators SOX2 and NANOG. Our data set includes regulators of ACTIVIN, BMP, fibroblast growth factor, and WNT signaling. These pathways are implicated in regulating human ESC differentiation and therefore further validate the results of our analysis. In addition, we identified a number of differentially expressed genes that are involved in epigenetics, chromatin remodeling, apoptosis, and metabolism that may point to underlying molecular mechanisms that regulate pluripotency and trophoblast differentiation in humans. Significant concordance between this data set and previous comparisons between inner cell mass and trophectoderm in human embryos indicates that the study of human ESC differentiation in vitro represents a useful model of early embryonic differentiation in humans
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