title: Urban outdoor water use and response to drought assessed through mobile energy balance and vegetation greenness measurements

authors: Liang, Liyin L.

subjects: Science & Technology

abstract: Urban vegetation provides many highly valued ecosystem services but also requires extensive urban water resources. Increasingly, cities are experiencing water limitations and managing outdoor urban water use is an important concern. Quantifying the water lost via evapotranspiration (ET) is critical for urban water management and conservation, especially in arid or semi-arid regions. In this study, we deployed a mobile energy balance platform to measure evaporative fraction throughout Riverside, California, a warm, semi-arid, city. We observed the relationship between evaporative fraction and satellite derived vegetation index across 29 sites, which was then used to map whole-city ET for a representative mid-summer period. Resulting ET distributions were strongly associated with both neighborhood population density and income. By comparing 2014 and 2015 summer-period water uses, our results show 7.8% reductions in evapotranspiration, which were also correlated with neighborhood demographic characteristics. Our findings suggest a mobile energy balance measurement platform coupled with satellite imagery could serve as an effective tool in assessing the outdoor water use at neighborhood to whole city scales.

text: Urban outdoor water use and response to drought assessed through mobile energy balance and vegetation greenness measurements Urban vegetation provides many highly valued ecosystem services but also requires extensive urban water resources. Increasingly, cities are experiencing water limitations and managing outdoor urban water use is an important concern. Quantifying the water lost via evapotranspiration (ET) is critical for urban water management and conservation, especially in arid or semi-arid regions. In this study, we deployed a mobile energy balance platform to measure evaporative fraction throughout Riverside, California, a warm, semi-arid, city. We observed the relationship between evaporative fraction and satellite derived vegetation index across 29 sites, which was then used to map whole-city ET for a representative mid-summer period. Resulting ET distributions were strongly associated with both neighborhood population density and income. By comparing 2014 and 2015 summer-period water uses, our results show 7.8% reductions in evapotranspiration, which were also correlated with neighborhood demographic characteristics. Our findings suggest a mobile energy balance measurement platform coupled with satellite imagery could serve as an effective tool in assessing the outdoor water use at neighborhood to whole city scales.

year: 2017-08-01

title: Tests of predictions made by the Equilibrium Model for the effect of temperature on enzyme activity

authors: Oudshoorn, Matthew Leslie

subjects: enzymes

abstract: The Classical Model describing the effects of temperature on enzyme activity consists of two processes: the catalytic reaction defined by ΔG cat and irreversible inactivation defined by ΔG inact, this model however, does not account for the observed temperature- dependant behaviour of enzymes. The recent development of the Equilibrium Model is governed not only by ΔG cat and ΔG inact but also by two new intrinsic parameters ΔHeq and Teq, which describe the enthalpy and the temperature of the midpoint, respectively, of a active and reversibly inactive enzyme transition. Teq is central to the physiological adaptation of an enzyme to its environmental temperature and links the molecular, physiological and environmental aspects of life to temperature in a way that has not been previously possible. The Equilibrium Model is therefore a more complete and accurate description of the effects of temperature on enzymes, it has provided new tools for describing and investigating enzyme thermal adaptation and possibly new biotechnological tools.

The effects of the incorporating in the new Model of the parameters Teq and ΔH eq yield major differences from the Classical Model, with simulated data calculated according to the Equilibrium Model fitting well to experimental data and showing an initial rate temperature optimum that is independent of assay duration. Simulated data simulated according to the Classical Model can not be fitted to experimental data. All enzymes so far studied (gt30) display behaviour predicted by the Equilibrium Model.

The research described here has set out to: experimentally test observations made by Eisenthal et al., on the basis of enzyme reactor data simulated according to the Equilibrium Model; to test the Equilibrium Model using an unusual (rapidly renaturable) enzyme, RNAase; and to test the proposed molecular basis of the Equilibrium Model by examining the effect of a change at the enzymes active site.

The experimental results gathered here on the effect of time and temperature on enzyme reactor output confirm the predictions made by Eisenthal et al. (2006) and indicate that the Equilibrium Model can be a useful aid in predicting reactor performance. The Equilibrium Model depends upon the acquisition of data on the variation of the Vmax of an enzyme with time and temperature, and the non-ideal behaviour of RNase A made it impossible to collect such data for this enzyme, as a result the Equilibrium Model could not be applied. The disulfide bond within the active site cleft of A.k 1 protease was cleaved as a probe of the mechanism of the Equilibrium Model, which is proposed to arise from molecular changes at the enzymes active site. Support for the proposed mechanism was gained through the comparison of experimentally determined temperature dependence of the native and reduced forms of the enzyme and application of this data to the Equilibrium Model.

text: Tests of predictions made by the Equilibrium Model for the effect of temperature on enzyme activity The Classical Model describing the effects of temperature on enzyme activity consists of two processes: the catalytic reaction defined by ΔG cat and irreversible inactivation defined by ΔG inact, this model however, does not account for the observed temperature- dependant behaviour of enzymes. The recent development of the Equilibrium Model is governed not only by ΔG cat and ΔG inact but also by two new intrinsic parameters ΔHeq and Teq, which describe the enthalpy and the temperature of the midpoint, respectively, of a active and reversibly inactive enzyme transition. Teq is central to the physiological adaptation of an enzyme to its environmental temperature and links the molecular, physiological and environmental aspects of life to temperature in a way that has not been previously possible. The Equilibrium Model is therefore a more complete and accurate description of the effects of temperature on enzymes, it has provided new tools for describing and investigating enzyme thermal adaptation and possibly new biotechnological tools.

The effects of the incorporating in the new Model of the parameters Teq and ΔH eq yield major differences from the Classical Model, with simulated data calculated according to the Equilibrium Model fitting well to experimental data and showing an initial rate temperature optimum that is independent of assay duration. Simulated data simulated according to the Classical Model can not be fitted to experimental data. All enzymes so far studied (gt30) display behaviour predicted by the Equilibrium Model.

The research described here has set out to: experimentally test observations made by Eisenthal et al., on the basis of enzyme reactor data simulated according to the Equilibrium Model; to test the Equilibrium Model using an unusual (rapidly renaturable) enzyme, RNAase; and to test the proposed molecular basis of the Equilibrium Model by examining the effect of a change at the enzymes active site.

The experimental results gathered here on the effect of time and temperature on enzyme reactor output confirm the predictions made by Eisenthal et al. (2006) and indicate that the Equilibrium Model can be a useful aid in predicting reactor performance. The Equilibrium Model depends upon the acquisition of data on the variation of the Vmax of an enzyme with time and temperature, and the non-ideal behaviour of RNase A made it impossible to collect such data for this enzyme, as a result the Equilibrium Model could not be applied. The disulfide bond within the active site cleft of A.k 1 protease was cleaved as a probe of the mechanism of the Equilibrium Model, which is proposed to arise from molecular changes at the enzymes active site. Support for the proposed mechanism was gained through the comparison of experimentally determined temperature dependence of the native and reduced forms of the enzyme and application of this data to the Equilibrium Model.

year: 2008

title: Respecting and recognising Indigenous rights when challenged by commercial activities

authors: Toki, Valmaine

abstract: The United Nations Declaration on the Rights of Indigenous Peoples was hailed as a triumph among Indigenous peoples, signalling a long-awaited recognition of their fundamental human rights. Despite this, many violations of these basic rights continue, particularly in relation to extractive industries and business activities. In response, a business reference guide seeks to inform industries of their responsibilities. This article examines the tenuous relationship between Indigenous rights, state responsibilities and business expectations.

text: Respecting and recognising Indigenous rights when challenged by commercial activities The United Nations Declaration on the Rights of Indigenous Peoples was hailed as a triumph among Indigenous peoples, signalling a long-awaited recognition of their fundamental human rights. Despite this, many violations of these basic rights continue, particularly in relation to extractive industries and business activities. In response, a business reference guide seeks to inform industries of their responsibilities. This article examines the tenuous relationship between Indigenous rights, state responsibilities and business expectations.

year: 2018