952 resultados para vision in water
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A critical survey of the impact on public water of water multinationals, local private companies, and water-consuming multinationals.
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A comprehensive global analysis of the use of public-public partnerships in water in over 60 countries.
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Water operators need to be efficient, accountable, honest public institutions providing a universal service. Many water services however lack the institutional strength, the human resources, the technical expertise and equipment, or the financial or managerial capacity to provide these services. They need support to develop these capacities. The vast majority of water operators in the world are in the public sector – 90% of all major cities are served by such bodies. This means that the largest pool of experience and expertise, and the great majority of examples of good practice and sound institutions, are to be found in existing public sector water operators. Because they are public sector, however, they do not have any natural commercial incentive to provide international support. Their incentive stems from solidarity, not profit. Since 1990, however, the policies of donors and development banks have focussed on the private companies and their incentives. The vast resources of the public sector have been overlooked, even blocked by pro-private policies. Out of sight of these global policy-makers, however, a growing number of public sector water companies have been engaged, in a great variety of ways, in helping others develop the capacity to be effective and accountable public services. These supportive arrangements are now called 'public-public partnerships' (PUPs). A public-public partnership (PUP) is simply a collaboration between two or more public authorities or organisations, based on solidarity, to improve the capacity and effectiveness of one partner in providing public water or sanitation services. They have been described as: “a peer relationship forged around common values and objectives, which exclude profit-seeking”.1 Neither partner expects a commercial profit, directly or indirectly. This makes PUPs very different from the public–private partnerships (PPPs) which have been promoted by the international financial institutions (IFIs) like the World Bank. The problems of PPPs have been examined in a number of reports. A great advantage of PUPs is that they avoid the risks of such partnerships: transaction costs, contract failure, renegotiation, the complexities of regulation, commercial opportunism, monopoly pricing, commercial secrecy, currency risk, and lack of public legitimacy.2 PUPs are not merely an abstract concept. The list in the annexe to this paper includes over 130 PUPs in around 70 countries. This means that far more countries have hosted PUPs than host PPPs in water – according to a report from PPIAF in December 2008, there are only 44 countries with private participation in water. These PUPs cover a period of over 20 years, and been used in all regions of the world. The earliest date to the 1980s, when the Yokohama Waterworks Bureau first started partnerships to help train staff in other Asian countries. Many of the PUP projects have been initiated in the last few years, a result of the growing recognition of PUPs as a tool for achieving improvements in public water management. This paper attempts to provide an overview of the typical objectives of PUPs; the different forms of PUPs and partners involved; a series of case studies of actual PUPs; and an examination of the recent WOPs initiative. It then offers recommendations for future development of PUPs.
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Satellite-derived remote-sensing reflectance (Rrs) can be used for mapping biogeochemically relevant variables, such as the chlorophyll concentration and the Inherent Optical Properties (IOPs) of the water, at global scale for use in climate-change studies. Prior to generating such products, suitable algorithms have to be selected that are appropriate for the purpose. Algorithm selection needs to account for both qualitative and quantitative requirements. In this paper we develop an objective methodology designed to rank the quantitative performance of a suite of bio-optical models. The objective classification is applied using the NASA bio-Optical Marine Algorithm Dataset (NOMAD). Using in situRrs as input to the models, the performance of eleven semi-analytical models, as well as five empirical chlorophyll algorithms and an empirical diffuse attenuation coefficient algorithm, is ranked for spectrally-resolved IOPs, chlorophyll concentration and the diffuse attenuation coefficient at 489 nm. The sensitivity of the objective classification and the uncertainty in the ranking are tested using a Monte-Carlo approach (bootstrapping). Results indicate that the performance of the semi-analytical models varies depending on the product and wavelength of interest. For chlorophyll retrieval, empirical algorithms perform better than semi-analytical models, in general. The performance of these empirical models reflects either their immunity to scale errors or instrument noise in Rrs data, or simply that the data used for model parameterisation were not independent of NOMAD. Nonetheless, uncertainty in the classification suggests that the performance of some semi-analytical algorithms at retrieving chlorophyll is comparable with the empirical algorithms. For phytoplankton absorption at 443 nm, some semi-analytical models also perform with similar accuracy to an empirical model. We discuss the potential biases, limitations and uncertainty in the approach, as well as additional qualitative considerations for algorithm selection for climate-change studies. Our classification has the potential to be routinely implemented, such that the performance of emerging algorithms can be compared with existing algorithms as they become available. In the long-term, such an approach will further aid algorithm development for ocean-colour studies.
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Aim: To study the relation between visual impairment and ability to care for oneself or a dependant in older people with age related macular degeneration (AMD). Method: Cross sectional study of older people with visual impairment due to AMD in a specialised retinal service clinic. 199 subjects who underwent visual function assessment (fully corrected distance and near acuity and contrast sensitivity in both eyes), followed by completion of a package of questionnaires dealing with general health status (SF36), visual functioning (Daily Living Tasks Dependent on Vision, DLTV) and ability to care for self or provide care to others. The outcome measure was self reported ability to care for self and others. Three levels of self reported ability to care were identified—inability to care for self (level 1), ability to care for self but not others (level 2), and ability to care for self and others (level 3). Results: People who reported good general health status and visual functioning (that is, had high scores on SF36 and DLTV) were more likely to state that they were able to care for self and others. Similarly people with good vision in the better seeing eye were more likely to report ability to care for self and others. People with a distance visual acuity (DVA) worse than 0.4 logMAR (Snellen 6/15) had less than 50% probability of assigning themselves to care level 3 and those with DVA worse than 1.0 logMAR (Snellen 6/60) had a probability of greater than 50% or for assigning themselves to care level 1. Regression analyses with level of care as the dependent variable and demographic factors, DLTV subscales, and SF36 dimensions as the explanatory variables confirmed that the DLTV subscale 1 was the most important variable in the transition from care level 3 to care level 2. The regression analyses also confirmed that the DLTV subscale 2 was the most important in the transition from care level 3 to care level 1. Conclusions: Ability to care for self and dependants has a strong relation with self reported visual functioning and quality of life and is adversely influenced by visual impairment. The acuity at which the balance of probability shifts in the direction of diminished ability to care for self or others is lower than the level set by social care agencies for provision of support. These findings have implications for those involved with visual rehabilitation and for studies of the cost effectiveness of interventions in AMD.
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The eastern Canadian Arctic is home to Canada’s largest Indigenous population, which depends on local freshwater sources for drinking water. However, small watersheds have rarely been analyzed for long-term hydrologic response to changing climate. This study aims to address this issue by examining the Apex River, a small watershed with a long hydroclimatic record, near Iqaluit, Nunavut. Particular emphasis was placed on the long-term changes in climate and river discharge, and the seasonal variability of water sources between two snapshots in time, 1983 and 2013. Long-term hydrological data were obtained from gauge station 10UH002, operated by Environment and Climate Change Canada, and long-term meteorological data were acquired from Environment Canada–operated stations near Iqaluit Airport. Breakpoint analysis suggested that long-term mean annual surface air temperatures have increased since 1994. In contrast, no long-term total precipitation or annual discharge changes were observed. However, river flow initiation and cessation analyses of the Apex River flow season indicates that flow extended into the autumn since the 2000s. The 2013 flow season lasted 44 days longer than the 1983 flow season. Systematic river sampling was undertaken throughout the 2013 thaw season to determine contributing proportions of event (snowmelt or rainfall) and pre-event (baseflow) water to river runoff. Results from the stable isotope hydrograph separation for 2013 were compared to findings for 1983. Snow was the main source of water to the river during the snowmelt period in 1983 and 2013, however baseflow was still an important contributor. Although there was high similarity of water sources early in the season in 1983 and 2013, the two years differed during the autumn. In 2013 there was a high rainfall runoff response that was not present in 1983, suggesting high release of late-season sub-surface water storage and an increased sensitivity to late-season rainfall events in 2013. This research provides insights into the hydrologic response of the Apex River to long-term climatic change, and highlights the need for high-quality precipitation and discharge data for effective long-term hydrological assessment.