79 research outputs found
Maturation-associated gene expression profiles during normal human bone marrow erythropoiesis
Erythropoiesis has been extensively studied using in vitro and in vivo animal models. Despite this, there is still limited data about the gene expression profiles (GEP) of primary (ex vivo) normal human bone marrow (BM) erythroid maturation. We investigated the GEP of nucleated red blood cell (NRBC) precursors during normal human BM erythropoiesis. Three maturation-associated populations of NRBC were identified and purified from (fresh) normal human BM by flow cytometry and the GEP of each purified cell population directly analyzed using DNA oligonucleotide microarrays. Overall, 6569 genes (19% of the genes investigated) were expressed in >= 1 stage of BM erythropoiesis at stable (e.g., genes involved in DNA process, cell signaling, protein organization and hemoglobin production) or variable amounts (e.g., genes related to cell differentiation, apoptosis, metabolism), the latter showing a tendency to either decrease from stage 1 to 3 (genes associated with regulation of erythroid differentiation and survival, e.g., SPI1, STAT5A) or increase from stage 2 to stage 3 (genes associated with autophagy, erythroid functions such as heme production, e.g., ALAS1, ALAS2), iron metabolism (e.g., ISCA1, SLC11A2), protection from oxidative stress (e.g., UCP2, PARK7), and NRBC enucleation (e.g., ID2, RB1). Interestingly, genes involved in apoptosis (e.g., CASP8, P2RX1) and immune response (e.g., FOXO3, TRAF6) were also unregulated in the last stage (stage 3) of maturation of NRBC precursors. Our results confirm and extend on previous observations and providing a frame of reference for better understanding the critical steps of human erythroid maturation and its potential alteration in patients with different clonal and non-clonal erythropoietic disorders.Stemcel biology/Regenerative medicine (incl. bloodtransfusion
Approximation of theoretical energy-saving potentials for the petrochemical industry using energy balances for 68 key processes
We prepared energy and carbon balances for 68 petrochemical processes in the petrochemical industry for Western Europe, the Netherlands and the world. We analysed the process energy use in relation to the heat effects of the chemical reactions and quantified in this way the sum of all energy inputs into the processes that do not end up in the useful products of the process, but are lost as waste heat to the environment. We showed that both process energy use and heat effects of reaction contribute significantly to the overall energy loss of the processes studied and recommend addressing reaction effects explicitly in energy-efficiency studies. We estimated the energy loss in Western Europe in the year 2000 at 1620 PJ of final energy and 1936 PJ of primary energy, resulting in a total of 127 Mt CO2. The losses identified can be regarded as good approximations of the theoretical energy-saving potentials of the processes analysed. The processes with large energy losses in relative (per tonne of product) and absolute (in PJ per year) terms are recommended for more detailed analysis taking into account further thermodynamic, economic, and practical considerations to identify technical and economic energy-saving potentials
Stakeholder Salience Changes in an e-Government Implementation Project
In this article we discuss in what ways an e-government project can give both expected and unexpected effects for agency employees and their working tasks. The purpose of this article is to illustrate the fact that, besides the aim to increase agency efficiency and citizen benefit, e-government implementation might also change the salience of involved stakeholders. We do this by focusing on one stakeholder group which was reluctant and hesitating in the beginning of the studied project; marginalized, passive, easily convinced, and old-fashioned. After the e-government implementation, this group had turned to satisfied, proud, influential, active, powerful, and modern IT users. The case shows how stakeholder salience might change over time in an e-government project. Stakeholder influence aspects and IT driven change aspects are intertwined. This makes it necessary for any e-government project to address the notion of stakeholder involvement in decision-making during the development and implementation phases, but also to acknowledge e-services force to change how things and people are perceived during these phases
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