Tap water costs and service sustainability, a close relationship

Water is currently an essential and strategic resource for society and its importance will rise in the future due to the increasing number of threats. However, water management is not currently up to par taking into consideration this well acknowledged importance. Generally speaking, water use is not efficient and loss figures are often too high. The reasons behind this situation are complex and diverse, however, in principle, they can be divided into four categories: cultural, political, social and economic. Since the latter are of most importance, this paper focuses on water costs from source to tap. The economic analysis presented quantifies the costs of a sustainable urban water service in a structured way. The second part of the paper present a case study in which the economic losses linked to leakage are assessed as a function of how expenses are recovered. The cost of apparent losses could also be assessed in a similar way and will always be higher, since apparent losses (unlike real ones) are present throughout the whole water cycle, thus increasing the unit costs.Cabrera Marcet, E.; Pardo Picazo, MA.; Cabrera Rochera, E.; Arregui De La Cruz, F. (2013). Tap water costs and service sustainability, a close relationship. Water Resources Management. 27(1):239-253. doi:10.1007/s11269-012-0181-3S239253271Almandoz J, Cabrera E, Arregui F, Cabrera Jr E, Cobacho R (2005) Leakage assessment through water networks simulation. J Water Resour Plan Manag ASCE. Nov-Dic. 2005 pp 458–466BDEW (German Association of Energy and Water Industries) (2010) Comparison of European Water and Wastewater Prices German Association of Energy and Water Industries, BonnCabrera E, Pardo MA, Cobacho R, Arregui FJ, Cabrera Jr E (2010) Energy audit of water networks. J. Water Resour. Plan. Manag. ASCE. Nov–Dic. 2010 pp 669–677Coase RH (1960) The problem of social cost. J Law Econ, October 1960den Blanken M (2009) Asset Management. A necessary tool for a modern water company AWWA International Conference on Strategic Asset Management. Miami 11–13 November 2009EPO (Eurostat Press Office) (2010) Facts and figures on the environment: from environmental taxes to water resources. Eurostat Press Office, Luxembourg, December 2010EU (European Union) (2000) Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000. Off J Eur Communities 22.12.2000. Pp L 327/1 to L 327/72IWA (International Water Association) (2010) International statistics for water services. Montreal 2010. Canada. International Water Association, LondonKanakoudis V, Tolikas D (2001) The role of leaks and breaks in water networks: technical and economical solutions. J Water SRT - Aqua 50(2001):301–311Kanakoudis V, Tsitsifli S (2009) Water pricing policies in Greece: is there a Common Understanding?. 2nd International conference on water economics, statistics, and finance Alexandroupolis, Thrace, Greece, 3–5 July 2009.Kanakoudis V, Gonelas K, Tolikas D (2011) Basic principles for urban water value assessment and price setting towards its full cost recovery – pinpointing the role of the water losses. J Water Supply: Res Technol 60(1):27–39Logar I, Van den Berg J (2012) Methods to assess costs of drought damages and policies for drought mitigation and adaptation: Review and recommendations. Water Resour Manag. doi: 10.1007/s11269-012-0119-9Molinos-Senante M, Hernández-Sancho F, Sala-Garrido R (2012) Tariffs and cost recovery in water reuse. Water Resour Manag. doi: 10.1007/s11269-012-0111-4NRC (National Research Council) (2008) Desalination a national perspective. NAP Press, Washington, D.C. National Research Council, Ottawa, CanadaOECD (Organisation for Economic Co-operation and Development) (2010) Pricing water resources and water and sanitation services. OECD, ParisOFWAT (Office of Water Services) (2009) Future water and sewerage charges 2010-15: Final determinations. OFWAT (Office of Water Services), Birmingham UKRogers P, Bhatia R, Huber A (1998) Water as a social and economic good: How to put the principle into practice. Global Water Partnership, Swedish International Development Cooperation Agency.Roth A (2001) Water pricing in the EU. A review. European Environmental Bureau (EEB), BrusselsWonnacott P, Wonnacott R (1990) Economics, 4th edn. John Wiley, 1990Zhu X, van Ierland EC (2012) Economic modeling for water quantity and quality management: a welfare program approach. Water Resour Manag. doi: 10.1007/s11269-012-0029-

ER-Bound Protein Tyrosine Phosphatase PTP1B Interacts with Src at the Plasma Membrane/Substrate Interface

PTP1B is an endoplasmic reticulum (ER) anchored enzyme whose access to substrates is partly dependent on the ER distribution and dynamics. One of these substrates, the protein tyrosine kinase Src, has been found in the cytosol, endosomes, and plasma membrane. Here we analyzed where PTP1B and Src physically interact in intact cells, by bimolecular fluorescence complementation (BiFC) in combination with temporal and high resolution microscopy. We also determined the structural basis of this interaction. We found that BiFC signal is displayed as puncta scattered throughout the ER network, a feature that was enhanced when the substrate trapping mutant PTP1B-D181A was used. Time-lapse and co-localization analyses revealed that BiFC puncta did not correspond to vesicular carriers; instead they localized at the tip of dynamic ER tubules. BiFC puncta were retained in ventral membrane preparations after cell unroofing and were also detected within the evanescent field of total internal reflection fluorescent microscopy (TIRFM) associated to the ventral membranes of whole cells. Furthermore, BiFC puncta often colocalized with dark spots seen by surface reflection interference contrast (SRIC). Removal of Src myristoylation and polybasic motifs abolished BiFC. In addition, PTP1B active site and negative regulatory tyrosine 529 on Src were primary determinants of BiFC occurrence, although the SH3 binding motif on PTP1B also played a role. Our results suggest that ER-bound PTP1B dynamically interacts with the negative regulatory site at the C-terminus of Src at random puncta in the plasma membrane/substrate interface, likely leading to Src activation and recruitment to adhesion complexes. We postulate that this functional ER/plasma membrane crosstalk could apply to a wide array of protein partners, opening an exciting field of research

Implication of 4E-BP1 protein dephosphorylation and accumulation in pancreatic cancer cell death induced by combined gemcitabine and TRAIL

Pancreatic cancer cells show varying sensitivity to the anticancer effects of gemcitabine. However, as a chemotherapeutic agent, gemcitabine can cause intolerably high levels of toxicity and patients often develop resistance to the beneficial effects of this drug. Combination studies show that use of gemcitabine with the pro-apoptotic cytokine TRAIL can enhance the inhibition of survival and induction of apoptosis of pancreatic cancer cells. Additionally, following combination treatment there is a dramatic increase in the level of the hypophosphorylated form of the tumour suppressor protein 4E-BP1. This is associated with inhibition of mTOR activity, resulting from caspase-mediated cleavage of the Raptor and Rictor components of mTOR. Use of the pan-caspase inhibitor Z-VAD-FMK indicates that the increase in level of 4E-BP1 is also caspase-mediated. ShRNA-silencing of 4E-BP1 expression renders cells more resistant to cell death induced by the combination treatment. Since the levels of 4E-BP1 are relatively low in untreated pancreatic cancer cells these results suggest that combined therapy with gemcitabine and TRAIL could improve the responsiveness of tumours to treatment by elevating the expression of 4E-BP1