Hazard identification framework for water utilities with application to the city of Xalapa,Mexico

Abstract:

There is a growing need for a comprehensive approach for assessing drinking water systems that enables managers and engineers to quickly address critical hazards that impact their water supply systems and plan for system improvements. A hazard identification framework for water utilities is developed and applied to the municipal water supply system at Xalapa, Veracruz, Mexico, operated by the Comisión Municipal de Agua Potable y Saneamiento de Xalapa (CMAS Xalapa). The framework is designed to aid in the analysis of a water supply system from catchment to tap and consists of four components: system characterization, identification of hazards, assessment of the impacts of the major hazards, and determination of priority recommendations for system improvements. When the framework is applied to the CMAS Xalapa system, a number of significant hazardous events are identified including elevated turbidity events and high pressure surcharges. Recommendations for system improvements include increased data collection and analysis and enhanced management of control measures for mitigating the impacts of the hazards.     

On Oxygen Diffusion in tetragonal zirconia

Oxygen diffusion in dense scales of tetragonal zirconia at 1100–1300°C has been studied by the so-called interruption kinetic method (or the Rosenberg method). Assuming that oxygen vacancies are the predominant defects in zirconia (ZrO₂), studies by this method provide values of the oxygen self diffusion coefficient in this oxide at its lower limit of stability, D, and the value in tetragonal zirconia can be expressed as D =2.2 · 10^?3 exp (?140(kJ/mole)/RT). The studies furthermore show that the maximum non-stoichiometry in tetragonal zirconia, X in ZrO_2?x, is small and has a value about x* ～ 0.03 at 1000–1300°C.     

Cytochrome c Catalyzes the Hydrogen Peroxide‐Assisted Oxidative Desulfuration of 2‐Thiouridines in Transfer RNAs

The 5‐substituted 2‐thiouridines (R5S2Us) present in the first (wobble) position of the anticodon of transfer RNAs (tRNAs) contribute to accuracy in reading mRNA codons and tuning protein synthesis. Previously, we showed that, under oxidative stress conditions in vitro, R5S2Us were sensitive to hydrogen peroxide (H₂O₂) and that their oxidative desulfuration produced 5‐substituted uridines (R5Us) and 4‐pyrimidinone nucleosides (R5H2Us) at a ratio that depended on the pH and an R5 substituent. Here, we demonstrate that the desulfuration of 2‐thiouridines, either alone or within an RNA/tRNA chain, is catalyzed by cytochrome c (cyt c). Its kinetics are similar to those of Fenton‐type catalytic 2‐thiouridine (S2U) desulfuration. Cyt c/H₂O₂‐ and Fe^II‐mediated reactions deliver predominantly 4‐pyrimidinone nucleoside (H2U)‐type products. The pathway of the cyt c/H₂O₂‐peroxidase‐mediated S2U→H2U transformation through uridine sulfenic (U‐SOH), sulfinic (U‐SO₂H), and sulfonic (U‐SO₃H) intermediates is confirmed by LC–MS. The cyt c/H₂O₂‐mediated oxidative damage of S2U‐tRNA may have biological relevance through alteration of the cellular functions of transfer RNA.     

Editorial: Smart Objects and Technologies for Social Good (GOODTECHS 2017)

Mobile Networks and Applications -     

On the Implication of Water on Fragment‐to‐Ligand Growth in Kinase Binding Thermodynamics

A ligand‐binding study is presented focusing on thermodynamics of fragment expansion. The binding of four compounds with increasing molecular weight to protein kinase A (PKA) was analyzed. The ligands display affinities between low‐micromolar to nanomolar potency despite their low molecular weight. Binding free energies were measured by isothermal titration calorimetry, revealing a trend toward more entropic and less enthalpic binding with increase in molecular weight. All protein–ligand complexes were analyzed by crystallography and solution NMR spectroscopy. Crystal structures and solution NMR data are highly consistent, and no major differences in complex dynamics across the series are observed that would explain the differences in the thermodynamic profiles. Instead, the thermodynamic trends result either from differences in the solvation patterns of the conformationally more flexible ligand in aqueous solution prior to protein binding as molecular dynamics simulations suggest, or from local shifts of the water structure in the ligand‐bound state. Our data thus provide evidence that changes in the solvation pattern constitute an important parameter for the understanding of thermodynamic data in protein–ligand complex formation.     

Requirements Engineering and Technology Transfer: Obstacles, Incentives and Improvement Agenda

For many years, research results in requirements engineering (RE) have been developed without much interaction with, or impact on, industrial practice. Why is it so difficult to introduce RE research results into mainstream RE practice? This paper attempts to provide answers to this question by describing obstacles that researchers and practitioners have encountered when they attempted technology transfer. In addition, major incentives for using RE methods are discussed, along with ideas for improving current RE practice. The paper summarises, clarifies and extends the results of two panel discussions, one at the Twelfth Conference on Advanced information Systems Engineering (CAiSE’00) and the other at the Fourth IEEE Conference on Requirements Engineering (ICRE’00).     

Murphy's surfers or: Where is the green? lure and lore on the internet

In this paper, we explore some characteristics of the Information Superhighway and the World Wide Web metaphors in the light of the current developments in information technology. We propose that these characteristics constitute a form of conceptual slippage (often in the form of lexical leakage), which helps us detect and predict the tacit impact that the currently available information delivery systems are having on human cognition. We argue that the particular language associated with these systems evolves as a direct result of human cognitive adaptation to the demands, resources, and constraints of highly technological environments. It reflects a growing alienation of the users of computerized systems from the physical aspects of the natural environment in which the disseminated information was originally grounded. We believe that a careful investigation of the pragmatic phenomena which are operative when the information media jargon is used is appropriate to the aims of Cognitive Technology. The role of metaphor as a vehicle for self-expression, as mediated by criteria of relevance, is discussed from this perspective.     

Experimental evaluation of dynamic resource orchestration in multi-layer (packet over flexi-grid optical) networks

Network services in 5G will be rolled out as pools of virtual network functions (VNFs) exploiting the advantages of both software-defined networking and network function virtualization. In this context, 5G network services are envisaged as ordered sequences of VNFs resulting in the so-called VNF Forwarding Graphs (VNFFGs). Such VNFs can be allocated over a number of distributed but interconnected data centers (DCs). In this work, a cloud/network orchestrator is discussed to dynamically process and accommodate VNFFG requests over a pool of DCs interconnected by a multi-layer (packet/flexi-grid optical) transport network infrastructure. Two different cloud and network resource allocation algorithms are proposed aiming at: (1) minimizing the distance between the selected DCs and (2) minimizing the load (i.e., consumed cloud resources) of the chosen DCs. In the performance evaluation, the proposed algorithms are experimentally validated and compared on the CTTC ADRENALINE testbed.