TY - JOUR AB - Ran GTPase plays important roles in nucleocytoplasmic transport in interphase [1, 2] and in both spindle formation and nuclear envelope (NE) assembly during mitosis [3, 4, 5]. The latter functions rely on the presence of high local concentrations of GTP-bound Ran near mitotic chromatin [3, 4, 5]. RanGTP localization has been proposed to result from the association of Ran's GDP/GTP exchange factor, RCC1, with chromatin [6, 7, 8, 9], but Ran is shown here to bind directly to chromatin in two modes, either dependent or independent of RCC1, and, where bound, to increase the affinity of chromatin for NE membranes. We propose that the Ran binding capacity of chromatin contributes to localized spindle and NE assembly. AU - Bilbao-Cortés, Daniel AU - HETZER, Martin W AU - Längst, Gernot AU - Becker, Peter B. AU - Mattaj, Iain W. ID - 11124 IS - 13 JF - Current Biology KW - General Agricultural and Biological Sciences KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0960-9822 TI - Ran binds to chromatin by two distinct mechanisms VL - 12 ER - TY - JOUR AB - The small GTPase Ran is a key regulator of nucleocytoplasmic transport during interphase. The asymmetric distribution of the GTP-bound form of Ran across the nuclear envelope — that is, large quantities in the nucleus compared with small quantities in the cytoplasm — determines the directionality of many nuclear transport processes. Recent findings that Ran also functions in spindle formation and nuclear envelope assembly during mitosis suggest that Ran has a general role in chromatin-centred processes. Ran functions in these events as a signal for chromosome position. AU - HETZER, Martin W AU - Gruss, Oliver J. AU - Mattaj, Iain W. ID - 11123 IS - 7 JF - Nature Cell Biology KW - Cell Biology SN - 1465-7392 TI - The Ran GTPase as a marker of chromosome position in spindle formation and nuclear envelope assembly VL - 4 ER - TY - JOUR AB - For many years considerable efforts have been put into investigating and modelling hydrological processes of mountainous catchments. On the one hand, the complexity and intrinsically high variability of the involved processes as well as insufficient knowledge of the underlying physical mechanisms still induce large uncertainties in understanding observed phenomena and predicting the behaviour of the system. On the other hand, the demand for models that are able to simulate mountainous water resource systems is increasing because of the needs related to both water exploitation and water conservation, which clearly call for an integrated vision and modelling of these systems. Accordingly, this paper moves from a brief survey of the most significant achievements in mountain hydrology to discuss what could be future challenging issues related to the broader spectrum of questions, which hydrologic modelling of mountainous river systems may face in the next decades. Firstly, reference is made to existing methodologies for modelling alpine water systems, focussing on some specific aspects that provide a basis for the discussion of the weaknesses and perspectives of present simulation tools. The future is thus discussed, delineating some of the research challenges that may foster a comprehensive and integrated vision of water related issues in mountainous regions. AU - Burlando, Paolo AU - Pellicciotti, Francesca AU - Strasser, Ulrich ID - 12659 IS - 1 JF - Hydrology Research SN - 0029-1277 TI - Modelling mountainous water systems between learning and speculating looking for challenges VL - 33 ER - TY - CONF AB - New dyes of the type Ru(II)(bdmpp)(bpy) [where bdmpp is 2,6-bis(3,5-dimethyl-N-pyrazoyl)pyridine and bpy is 2,2′-bipyridine-4,4′-dicarboxylic acid] are prepared and characterized by infra-red (IR), mass (MS) and electrospray mass spectroscopy (ES-MS) as well as 1H NMR (1D and 2D) spectroscopies. The compounds present broad and very high intensity MLCT absorption bands in the visible and can be chemically anchored on TiO2 films via ester-like linkage involving carboxylato groups. These complexes have been tested with success as potential molecular antennas in dye-sensitized solar cells. Both opaque and transparent nanocrystalline TiO2 thin film electrodes obtained by a doctor blade technique sensitized by these complexes were incorporated in a sandwich type regenerative photoelectrochemical solar cell containing 0.1M LiI +0.01M I2 in propylene carbonate as well as a platinized conductive glass counter electrode. The cell was characterized by Raman spectroscopy under anodic and cathodic bias. Two new vibration bands were observed in the lower frequency region. The first one at 112 cm-1 is due to tri-iodide formed on the photoactive electrode, and the second one at 167 cm-1 is a sign of the dye/iodide interaction and corresponds to a vibration in a chemically stable "DI" intermediate species. Under direct sunlight illumination (solar irradiance of 60 mW/cm2) by using a composite polymer solid state electrolyte, the cell ITO/TiO2/[Ru(II)(bdmpp)(bpy)(NCS)](PF6)/electrolyte/Pt-ITO produced a continuous photocurrent as high as 4.29mA/cm2, and gave IPCE values about half of the corresponding values obtained by the standard N3 dye under the same conditions. The photovoltage is about 600 mV and the overall energy conversion cell's efficiency is as high as 1.72%. AU - Falaras, Polycarpos AU - Chryssou, Katerina AU - Stergiopoulos, Thomas AU - Arabatzis, Ioannis M AU - Georgios Katsaros AU - Catalano, Vincent J AU - Kurtaran, Raif AU - Hugot-Le Goff, Anne AU - Bernard, Marie C ID - 1738 TI - Dye-sensitization of titanium dioxide thin films by Ru(II)-bpp-bpy complexes VL - 4801 ER - TY - JOUR AB - Poly(ethylene oxide)/titania polymer electrolyte based photoelectrochemical cells have been fabricated with Ru(dcbpy)2(NCS)2 complex as the sensitizer and nanoporous TiO2 films as photoanodes. The introduction of the titania filler into the poly(ethylene oxide) matrix reduces the crystallinity of the polymer and enhances the mobility of the 1-/13 - redox couple, resulting in outstanding overall conversion efficiency (4.2% under direct sunlight illumination) of the corresponding dye-sensitized nanocrystalline TiO2 solar cell, one of the best efficiencies reported to date for a solid-state device. AU - Stergiopoulos, Thomas AU - Arabatzis, Iannis M AU - Georgios Katsaros AU - Falaras, Polycarpos ID - 1739 IS - 11 JF - Nano Letters TI - Binary Polyethylene Oxide/Titania Solid-State Redox Electrolyte for Highly Efficient Nanocrystalline TiO2 Photoelectrochemical Cells VL - 2 ER -