An extension of the momentum transfer model to time-dependent pipe turbulence

We analyze a possible extension of Gioia and Chakraborty's momentum transfer model of friction in steady turbulent pipe flows (Phys. Rev. Lett. 96, 044502 (2006)) to the case of time and/or space dependent turbulent flows. The end result is an expression for the stress at the wall as the sum of an steady and a dynamic component. The steady part is obtained by using the instantaneous velocity in the expression for the stress at the wall of a stationary flow. The unsteady part is a weighted average over the history of the flow acceleration, with a weighting function similar to that proposed by Vardy and Brown (Journal of Sound and Vibration 259, 1011 (2003); ibid. 270, 233 (2004)), but naturally including the effect of spatial derivatives of the mean flow, as in the Brunone model (B. Brunone et al., J. of Water Resources Planning and Management 236 (2000)).Comment: 15 pages. 2 figures (included) arXiv admin note: text overlap with arXiv:1005.040

MicroRNA profiles discriminate among colon cancer metastasis

MicroRNAs are being exploited for diagnosis, prognosis and monitoring of cancer and other diseases. Their high tissue specificity and critical role in oncogenesis provide new biomarkers for the diagnosis and classification of cancer as well as predicting patients' outcomes. MicroRNAs signatures have been identified for many human tumors, including colorectal cancer (CRC). In most cases, metastatic disease is difficult to predict and to prevent with adequate therapies. The aim of our study was to identify a microRNA signature for metastatic CRC that could predict and differentiate metastatic target organ localization. Normal and cancer tissues of three different groups of CRC patients were analyzed. RNA microarray and TaqMan Array analysis were performed on 66 Italian patients with or without lymph nodes and/or liver recurrences. Data obtained with the two assays were analyzed separately and then intersected to identify a primary CRC metastatic signature. Five differentially expressed microRNAs (hsa-miR-21, -103, -93, -31 and -566) were validated by qRT-PCR on a second group of 16 American metastatic patients. In situ hybridization was performed on the 16 American patients as well as on three distinct commercial tissues microarray (TMA) containing normal adjacent colon, the primary adenocarcinoma, normal and metastatic lymph nodes and liver. Hsa-miRNA-21, -93, and -103 upregulation together with hsa-miR-566 downregulation defined the CRC metastatic signature, while in situ hybridization data identified a lymphonodal invasion profile. We provided the first microRNAs signature that could discriminate between colorectal recurrences to lymph nodes and liver and between colorectal liver metastasis and primary hepatic tumor

Strategic Research Agenda of the EERA Joint Programme Hydropower

The launch of a new EERA Joint Programme on Hydropower is good news for energy system in Europe and beyond. The clean energy transition is necessary, demanding and accelerating. Hydropower in Europe and worldwide represents a significant tool for achieving this change sustainably. Hydropower holds capabilities for energy supply, storage, and regulation that are unique. These characteristics are needed to deliver security of supply, stability in the grid, and for green growth. Increasing the flexibility of the hydropower fleet through innovation and modernisation is fundamental for these objectives. Hydropower has a lot to offer. It can provide water management capabilities, mitigating damage from flood and drought events; it will provide clean energy and available capacity for stable and secure supplies; it will balance intermittent production from solar and wind, and it is capable of storing energy, both in short and long-term horizons. Hydropower rates very well in comparison to other renewable electricity production sources, including storage: energy-payback ratio, life-cycle assessment, greenhouse-gas emissions, water footprint, and more. Adding to that, hydropower has the highest energy-conversion efficiency and longest operating life. Without research, demonstration and investment, none of these roles will be optimised for the future. Europe is instrumental in leading the way towards decarbonisation through competence building and innovation. And the Joint Programme on hydropower represents a renewed focus on new roles and priorities for hydropower; we can no longer rely only on the mature solutions and methods; we need to bring our existing knowledge further. What happens in a power plant that shall handle thirty starts and stops each day? How can we utilise rotating mass to provide instant regulation for the system? How will power peaking affect the watercourse, and how can we integrate water management solutions together with power production, recreation and navigation? New challenges present new opportunities, but also new needs for research and innovation. The Joint Programme on Hydropower in EERA comprises a large group of excellent and dedicated R&D-communities in Europe. Our joint eff orts will be a major hub for renewed research, supporting eff orts to modernise the European fleet and assist the rest of the world, where the largest potential for new hydropower development lies. My hopes and expectations for this initiative is that it will expand globally and be a platform for research on topics related to hydropower in a world-wide perspective. The need for this initiative is clear, and everyone involved should be very proud of the launch of this platform