955 resultados para Water resources on information systems


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The electro-oxidation of ethanol on platinum in phosphoric acid opens the door to promote the oxidation reaction at higher temperatures. However, the effect of the presence of water is not well understood. In this work, the electro-oxidation of ethanol on platinum was studied in concentrated phosphoric acid containing different concentrations of water at room temperature. The results show that effect of bulk water on the rate electro-oxidation is highest at 0.60 V and decreases for increasing potentials. This was suggested as due to the increasing formation of oxygenated species on the electrode surface with potential, which in turn is more efficient than the increase of water content in the electrolyte. Altogether, these results were interpreted as an evidence of a Langmuir-Hinshelwood step involving oxygenated species as one of the adsorbed partners. (C) 2009 Elsevier B.V. All rights reserved.

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The advent of the World Wide Web (WWW) and the emergence of Internet commerce have given rise to the web as a medium of information exchange. In recent years, the phenomenon has affected the realm of transaction processing systems, as organizations are moving from designing web pages for marketing purposes, to web-based applications that support business-to-business (WEB) and business-to-consumer (B2C) interactions, integrated with databases and other back-end systems (Isakowitz, Bieber et al., 1998). Furthermore, web-enabled applications are increasingly being used to facilitate transactions even between various business units within a single enterprise. Examples of some of the more popular web-enabled applications in use today include airline reservation systems, internet banking, student enrollment systems in universities, and Human Resource (HR) and payroll systems. The prime motive behind the adoption of web-enabled applications are productivity gains due to reduced processing time, decrease in the usage of paper-based documentation and conventional modes of communication (such as letters, fax, or telephone), and improved quality of services to clients. Indeed, web-based solutions are commonly referred to as customer-centric (Li, 2000), which means that they provide user interfaces that do not necessitate high level of computer proficiency. Thus, organizations implement such systems to streamline routine transactions and gain strategic benefits in the process (Nambisan & Wang, 1999), though the latter are to be expected in the long-term. Notwithstanding the benefits of web technology adoption, the web has ample share of challenges for initiators and developers. Many of these challenges are associated with the unique nature of web-enabled applications. Research in the area of web-enabled information systems has revealed several differences with traditional applications. These differences exist with regards to system development methodology, stakeholder involvement, tasks, and technology (Nazareth, 1998). According to Fraternali (1999), web applications are commonly developed using an evolutionary prototyping approach, whereby the simplified version of the application is deployed as a pilot first, in order to gather user feedback. Thus, web-enabled applications typically undergo continuous refinement and evolution (Ginige, 1998; Nazareth, 1998; Siau, 1998; Standing, 2001). Prototype-based development also leads web-enabled information systems to have much shorter development life cycles, but which, unlike traditional applications, are regrettably developed in a rather adhoc fashion (Carstensen & Vogelsang, 2001). However, the principal difference between the two kinds of applications lies in the broad and diverse group of stakeholders associated with web-based information systems (Gordijn, Akkermans, et al., 2000; Russo, 2000; Earl & Khan, 2001; Carter, 2002; Hasselbring, 2002; Standing, 2002; Stevens & Timbrell, 2002). Stakeholders, or organizational members participating in a common business process (Freeman, 1984), vary in their computer competency, business knowledge, language and culture. This diversity is capable of causing conflict between different stakeholder groups with regards to the establishment of system requirements (Pouloudi & Whitley, 1997; Stevens & Timbrell, 2002). Since, web-based systems transcend organizational, departmental, and even national boundaries, the issue of culture poses a significant challenge to the web systems’ initiators and developers (Miles & Snow, 1992; Kumar & van Dissel, 1996; Pouloudi & Whitley, 1996; Li & Williams, 1999).

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Proceedings of 12th International Conference on Information Systems and Development, held in Melbourne, Australia, August 29-31, 2003

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This chapter overviews the existing methods of requirements analysis as prescribed by some of the best-known web-development methods. It also discusses the pre-eminent importance of stakeholder analysis, identification of stakeholder views and concerns, and the processes governing elicitation of web systems requirements. The chapter finally derives a model of concern-driven requirements evolution from several case studies undertaken in the area of web-enabled employee service systems.

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Eucalyptus crenulata is a rare species known from only two populations. The Buxton Silver Gum Reserve was set aside in 1978 for the conservation of the species, but this objective may be compromised by changes in the integrity of the landscape immediately surrounding the Reserve. A time sequence of aerial photos and Geographic Information Systems technology has been used to identify patterns of landscape change, and aid in determining appropriate management strategies to minimize negative impacts caused by landscape fragmentation and habitat exposure

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This study investigated the mRNA expression of the atrial natriuretic peptide (ANP) system (peptide and receptors) during water deprivation in the spinifex hopping mouse, Notomys alexis, a native of central and western Australia that is well adapted to survive in arid environments. Initially, ANP, NPR-A and NPR-C cDNAs (partial for receptors) were cloned and sequenced, and were shown to have high homology with those of rat and mouse. Using a semi-quantitative multiplex PCR technique, the expression of cardiac ANP mRNA and renal ANP, NPR-A, and NPR-C mRNA was determined in 7- and 14-day water-deprived hopping mice, in parallel with control mice (access to water). The levels of ANP mRNA expression in the heart remained unchanged, but in the kidney ANP mRNA levels were increased in the 7-day water-deprived mice, and were significantly decreased in the 14-day water-deprived mice. NPR-A mRNA levels were significantly higher in 7-day water-deprived mice while no change for NPR-A mRNA expression was observed in 14-day water-deprived mice. No variation in NPR-C mRNA levels was observed. This study shows that water deprivation differentially affects the expression of the ANP system, and that renal ANP expression is more important than cardiac ANP in the physiological adjustment to water deprivation.

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In mammals the natriuretic and guanylin peptides influence renal and intestinal fluid content and electrolyte transport by binding to and activating guanylyl cyclase (GC) receptors that in turn stimulate production of the intracellular second messenger guanosine 3':5'-cyclic monophospate
(cGMP). However, the role of natriuretic and guanylin peptides in desert mammals is not understood. The spinifex hopping-mouse (Notomys alexis), has a suite of behavioural and physiological mechanisms that permits survival for extended periods without access to free water. Because signalling molecules that generate cGMP are known to promote water excretion, it was predicted that natriuretic and guanylin peptide synthesis would be down regulated in water-deprived N. alexis, and thus reduce the amount of water lost in the urine and faeces. However, in the kidney ANP and GC-A mRNA levels were increased in water-deprived mice, but CNP and GC-B mRNA levels were decreased. Water deprivation increased guanylin and uroguanylin mRNA expression in the distal colon, but it remained unchanged in the kidney and proximal colon. The expression of GC-C mRNA increased in the proximal colon but not in the distal colon. This study shows that water deprivation differentially affects the expression of regulatory molecules that stimulate cGMP producti

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Geographic Information Systems (GIS) can be used to objectively measure features of the built environment that may influence adults’ physical activity, which is an important determinant of chronic disease. We describe how a previously developed index of walkability was operationalised in an Australian context, using available spatial data. The index was used to generate a stratified sampling frame for the selection of households from 32 communities for the PLACE (Physical Activity in Localities and Community Environments) study. GIS data have the potential to be used to construct measures of environmental attributes and to develop indices of walkability for cities, regions or local communities.

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IS professionals are primarily concerned with the development of a project to meet the goals of a client. Unfortunately, IS professional do not always pay close attention to the contract or to its management and are often unaware of the legal implications of the contracts to which they are assenting. Legal advice can be sought during pre-contractual processes to help ensure that the contract meets the expectations of all the parties. If the project does not meet stakeholder’s expectations, thus causing a contract to come into dispute, lawyers may be called in to review the contract and to seek a settlement. This paper reports an exploratory study of the differences in perceptions of IS development contracts that exist between IS professionals and legal practitioners.

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Information Systems have been used for many years to analyze problems and compare options in a managed environment. The introduction of computer and information security systems into such an environment is a typical example of a situation to which an Information Systems approach can be applied. In this paper, we examine the issues peculiar to implementation of security in a healthcare environment, looking specifically at one such specially designed system, SIM-ETHICS, which takes a participational approach.

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This paper discusses how interpersonal conflict between IS developers and clients can disrupt IS projects.  It is suggested how potential problems can be avoided by getting the 'soft' factors right which can lead to improvements in information systems development (ISD) processes.  However little is being done in most organisations to review success from this perspective.  Measurement of ISD quality tends to favour the product rather than the human drivers that influence the development of the product.  Several ideas are put forward that can be used to resolve conflict and tp better involve stakeholders in the ISD process.