104 research outputs found
Living in Living Cities
This paper presents an overview of current and potential applications of
living technology to some urban problems. Living technology can be described as
technology that exhibits the core features of living systems. These features
can be useful to solve dynamic problems. In particular, urban problems
concerning mobility, logistics, telecommunications, governance, safety,
sustainability, and society and culture are presented, while solutions
involving living technology are reviewed. A methodology for developing living
technology is mentioned, while supraoptimal public transportation systems are
used as a case study to illustrate the benefits of urban living technology.
Finally, the usefulness of describing cities as living systems is discussed.Comment: 40 pages, 4 figures, overview pape
Optimal behavior of responsive residential demand considering hybrid phase change materials
Due to communication and technology developments, residential consumers are enabled to participate inΓΒ Demand Response Programs (DRPs), control their consumption and decrease their cost by usingΓΒ Household Energy Management (HEM) systems. On the other hand, capability of energy storage systemsΓΒ to improve the energy efficiency causes that employing Phase Change Materials (PCM) as thermal storageΓΒ systems to be widely addressed in the building applications. In this paper, an operational model of HEMΓΒ system considering the incorporation of more than one type of PCM in plastering mortars (hybrid PCM) isΓΒ proposed not only to minimize the customerΓ’ s cost in different DRPs but also to guaranty the habitantsΓ’ ΓΒ satisfaction. Moreover, the proposed model ensures the technical and economic limits of batteries andΓΒ electrical appliances. Different case studies indicate that implementation of hybrid PCM in the buildingsΓΒ can meaningfully affect the operational pattern of HEM systems in different DRPs. The results reveal thatΓΒ the customerΓ’ s electricity cost can be reduced up to 48% by utilizing the proposed model.The work of M. Shafie-khah and J.P.S. CatalΓ£o was supported by
FEDER funds through COMPETE and by Portuguese funds through FCT, under FCOMP-01-0124-FEDER-020282 (Ref. PTDC/EEA-EEL/118519/2010) and UID/CEC/50021/2013, and also by the EU 7th Framework Programme FP7/2007-2013 under Grant agreement No. 309048 (project SiNGULAR)
A Prokaryotic S1P Lyase Degrades Extracellular S1P In Vitro and In Vivo: Implication for Treating Hyperproliferative Disorders
Sphingosine-1-phosphate (S1P) regulates a broad spectrum of fundamental cellular processes like proliferation, death, migration and cytokine production. Therefore, elevated levels of S1P may be causal to various pathologic conditions including cancer, fibrosis, inflammation, autoimmune diseases and aberrant angiogenesis. Here we report that S1P lyase from the prokaryote Symbiobacterium thermophilum (StSPL) degrades extracellular S1P in vitro and in blood. Moreover, we investigated its effect on cellular responses typical of fibrosis, cancer and aberrant angiogenesis using renal mesangial cells, endothelial cells, breast (MCF-7) and colon (HCT 116) carcinoma cells as disease models. In all cell types, wild-type StSPL, but not an inactive mutant, disrupted MAPK phosphorylation stimulated by exogenous S1P. Functionally, disruption of S1P receptor signaling by S1P depletion inhibited proliferation and expression of connective tissue growth factor in mesangial cells, proliferation, migration and VEGF expression in carcinoma cells, and proliferation and migration of endothelial cells. Upon intravenous injection of StSPL in mice, plasma S1P levels rapidly declined by 70% within 1 h and then recovered to normal 6 h after injection. Using the chicken chorioallantoic membrane model we further demonstrate that also under in vivo conditions StSPL, but not the inactive mutant, inhibited tumor cell-induced angiogenesis as an S1P-dependent process. Our data demonstrate that recombinant StSPL is active under extracellular conditions and holds promise as a new enzyme therapeutic for diseases associated with increased levels of S1P and S1P receptor signaling
Intracellular S1P Generation Is Essential for S1P-Induced Motility of Human Lung Endothelial Cells: Role of Sphingosine Kinase 1 and S1P Lyase
Earlier we have shown that extracellular sphingosine-1-phosphate (S1P) induces migration of human pulmonary artery endothelial cells (HPAECs) through the activation of S1P(1) receptor, PKCΞ΅, and PLD2-PKCΞΆ-Rac1 signaling cascade. As endothelial cells generate intracellular S1P, here we have investigated the role of sphingosine kinases (SphKs) and S1P lyase (S1PL), that regulate intracellular S1P accumulation, in HPAEC motility
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