Duhemian Themes in Expected Utility Theory

This monographic chapter explains how expected utility (EU) theory arose in von Neumann and Morgenstern, how it was called into question by Allais and others, and how it gave way to non-EU theories, at least among the specialized quarters of decion theory. I organize the narrative around the idea that the successive theoretical moves amounted to resolving Duhem-Quine underdetermination problems, so they can be assessed in terms of the philosophical recommendations made to overcome these problems. I actually follow Duhem's recommendation, which was essentially to rely on the passing of time to make many experiments and arguments available, and evebntually strike a balance between competing theories on the basis of this improved knowledge. Although Duhem's solution seems disappointingly vague, relying as it does on "bon sens" to bring an end to the temporal process, I do not think there is any better one in the philosophical literature, and I apply it here for what it is worth. In this perspective, EU theorists were justified in resisting the first attempts at refuting their theory, including Allais's in the 50s, but they would have lacked "bon sens" in not acknowledging their defeat in the 80s, after the long process of pros and cons had sufficiently matured. This primary Duhemian theme is actually combined with a secondary theme - normativity. I suggest that EU theory was normative at its very beginning and has remained so all along, and I express dissatisfaction with the orthodox view that it could be treated as a straightforward descriptive theory for purposes of prediction and scientific test. This view is usually accompanied with a faulty historical reconstruction, according to which EU theorists initially formulated the VNM axioms descriptively and retreated to a normative construal once they fell threatened by empirical refutation. From my historical study, things did not evolve in this way, and the theory was both proposed and rebutted on the basis of normative arguments already in the 1950s. The ensuing, major problem was to make choice experiments compatible with this inherently normative feature of theory. Compability was obtained in some experiments, but implicitly and somewhat confusingly, for instance by excluding overtly incoherent subjects or by creating strong incentives for the subjects to reflect on the questions and provide answers they would be able to defend. I also claim that Allais had an intuition of how to combine testability and normativity, unlike most later experimenters, and that it would have been more fruitful to work from his intuition than to make choice experiments of the naively empirical style that flourished after him. In sum, it can be said that the underdetermination process accompanying EUT was resolved in a Duhemian way, but this was not without major inefficiencies. To embody explicit rationality considerations into experimental schemes right from the beginning would have limited the scope of empirical research, avoided wasting resources to get only minor findings, and speeded up the Duhemian process of groping towards a choice among competing theories

Tracing surface water dynamics and groundwater recharge at Inle Lake (Southern Shan State, Myanmar) using stable water isotopes

An isotopic monitoring (δ2H, δ18O) of the Inle lake (Southern Shan State, Myanmar) permitted to define the isotopic fingerprint of the lake in the three different seasons (rainy, winter and summer), and to support evidences of groundwater contribution to aquifer recharge in absence of precipitations

The Use of Nitrate Isotopes to Identify Contamination Sources in the Bou-Areg Aquifer (Morocco)

The Bou-Areg coastal aquifer (Morocco) is affected by high nitrate levels in groundwater, with possible consequences for the natural environment and human health. The use of environmental tracers, including delta N-15(NO3) and delta O-18(NO3), allowed identifying the main sources of nitrate contamination in groundwater samples collected in 2010. These are manure and septic effluents, especially in urban areas, and synthetic fertilizers in agricultural areas. This work represents a preliminary step for a more detailed nitrate vulnerability assessment to support groundwater management and protection in the studied region

The Sediments of Inle Lake (Southern Shan State, Myanmar): Mineralogical and Geochemical Characterisation to Tackle Origin and Depositional Processes

Inle Lake is the second largest lake in Myanmar and the most important, for its economic, touristic, agricultural and environmental value. Previous studies report that Inle lake is seriously threatened by anthropic activities on the lake sides and in its drainage basin, leading to a decrease in the open water surface, estimated to as much as 32.4% between 1935 and 2000. This is attributed to an increase in sedimentation caused by accelerated soil erosion, as a consequence of deforestation in the watershed, and to the expansion of agriculture in the form of floating gardens. [1] Ten sediment cores, ranging from 40 to 85 cm in length, were collected in March 2014 (hot dry season). Cores were cut in 5 cm slices, wrapped in polythene foil to prevent oxidation, and transported to the Department of Earth and Environment Sciences in Pavia (Italy). In the laboratory, sediment samples were dried at room temperature for 2-3 days in order to maintain the crystal structures, and ground to fine powder in an agate mortar. The mineralogical composition was determined by X-ray powder diffraction (XRPD), while the topography of some crystal structures and the elemental composition were analysed using scanning electron microscopy (SEM). Major and trace element contents were determined by Total Digestion ICP/MS. In the bulk sediment, the most abundant mineral is calcite (27 to 100%), followed by quartz (0 to 54%). Other less abundant minerals are: mica/illite (0 to 33%), kaolinite (0 to 14%), aragonite (0 to 15%) and hematite (0 to 9%). The clay fraction is mostly composed by kaolinite with lower mica/illite and chlorite, and traces of smectite. Calcite is not evenly distributed in the lake area: samples collected at or near the main inflow and at the outflow show an abundance of about 50%, generally increasing with depth, whereas within the lake calcite rises up to more than 90%. Endogenic calcite precipitation is known to occur in the warmer months, triggered by photosynthetic activity and evaporation of the water body [2], but detrital calcite is also likely present in the sediments. SEM observations showed a variety of grain morphologies and surface textures. Grains are medium to coarse in size (4-500 μm), and are commonly constituted by calcite and quartz. Sediments collected near the inflow show the abundance of detrital minerals such as feldspar, calcite and quartz, which can be attributed to soil erosion. In addition, coarse grains are dominated by mineral aggregates, also probably formed in the soil, in which calcite is associated with organic matter. Sediments from the centre of the lake, accounting for 90% of calcite, show both detrital and endogenic calcite grains, characterized by a rounded shape and by superposed layers, respectively. An apatite grain was detected in sediments from the agricultural zone, and attributed to the use of phosphate fertilizers in the floating gardens. Chemical analyses indicate that Ca is the most abundant element, in agreement with the abundance of calcite, followed by Al, Na and K, all elements contained in detrital minerals and associated heavy metals. The comparison between the elemental compositions of lake sediment with that of the rocks outcropping in the watershed confirmed that accelerated soil erosion, and the consequent detrital input to the lake, constituted a major source of potentially toxic elements to the lake

The sediments of Inle Lake (Southern Shan State, Myanmar): mineralogical and geochemical characterisation to tackle origin and depositional processes.

Inle Lake is the second largest lake in Myanmar and the most important, for its economic, touristic, agricultural and environmental value. Previous studies report that Inle lake is seriously threatened by anthropic activities on the lake sides and in its drainage basin, leading to a decrease in the open water surface, estimated to as much as 32.4% between 1935 and 2000. This is attributed to an increase in sedimentation caused by accelerated soil erosion, as a consequence of deforestation in the watershed, and to the expansion of agriculture in the form of floating gardens. [1] Ten sediment cores, ranging from 40 to 85 cm in length, were collected in March 2014 (hot dry season). Cores were cut in 5 cm slices, wrapped in polythene foil to prevent oxidation, and transported to the Department of Earth and Environment Sciences in Pavia (Italy). In the laboratory, sediment samples were dried at room temperature for 2-3 days in order to maintain the crystal structures, and ground to fine powder in an agate mortar. The mineralogical composition was determined by X-ray powder diffraction (XRPD), while the topography of some crystal structures and the elemental composition were analysed using scanning electron microscopy (SEM). Major and trace element contents were determined by Total Digestion ICP/MS. In the bulk sediment, the most abundant mineral is calcite (27 to 100%), followed by quartz (0 to 54%). Other less abundant minerals are: mica/illite (0 to 33%), kaolinite (0 to 14%), aragonite (0 to 15%) and hematite (0 to 9%). The clay fraction is mostly composed by kaolinite with lower mica/illite and chlorite, and traces of smectite. Calcite is not evenly distributed in the lake area: samples collected at or near the main inflow and at the outflow show an abundance of about 50%, generally increasing with depth, whereas within the lake calcite rises up to more than 90%. Endogenic calcite precipitation is known to occur in the warmer months, triggered by photosynthetic activity and evaporation of the water body [2], but detrital calcite is also likely present in the sediments. SEM observations showed a variety of grain morphologies and surface textures. Grains are medium to coarse in size (4-500 μm), and are commonly constituted by calcite and quartz. Sediments collected near the inflow show the abundance of detrital minerals such as feldspar, calcite and quartz, which can be attributed to soil erosion. In addition, coarse grains are dominated by mineral aggregates, also probably formed in the soil, in which calcite is associated with organic matter. Sediments from the centre of the lake, accounting for 90% of calcite, show both detrital and endogenic calcite grains, characterized by a rounded shape and by superposed layers, respectively. An apatite grain was detected in sediments from the agricultural zone, and attributed to the use of phosphate fertilizers in the floating gardens. Chemical analyses indicate that Ca is the most abundant element, in agreement with the abundance of calcite, followed by Al, Na and K, all elements contained in detrital minerals and associated heavy metals. The comparison between the elemental compositions of lake sediment with that of the rocks outcropping in the watershed confirmed that accelerated soil erosion, and the consequent detrital input to the lake, constituted a major source of potentially toxic elements to the lake

Tracing nitrification and denitrification processes in a periodically flooded shallow sandy aquifer

The study defi nes the transfer mechanisms of nutrients and heavy metals from soil to groundwater operating in periodically water saturated soils. The study site is located in Lomellina (Po plain, Northern Italy), which is intensively cultivated with rice. Soils are dominantly constituted by sands, with acidic pH and low organic carbon content. The region generally displays low nitrate contamination in shallow groundwater, despite the intensive land use, while Fe and Mn often exceed drinking water limits. Monitoring performed through a yearly cycle closely followed the water table fluctuations in response to periodical flooding and drying of cultivated fields. pH, conductivity and Eh were measured in the field. Water samples were analysed for major ions, trace elements, nutrients and stable isotopes of dissolved inorganic nitrate (DIN). Results evidence the seasonal migration of nutrients, the redox and associated metal cycling, and allow defining nitrifi ation and denitrification processes

Application of the multi-isotope approach to tackle nitrate pollution in water resources

Nitrate pollution represents a major concern in many world aqueous resources. When multiple potential nitrate sources exist, their identification and estimation of their contribution are essential to implement effective, source-oriented remediation measures. Isotope data represent a powerful tool, complementary to existing monitoring data, enabling to achieve these objectives. The potential offered by the use of this technique when tackling the environmental management of nitrate contamination is demonstrated via a number of case studies conducted in Europe and Africa, where isotope data lead to a better understanding of nitrate origin, degree of natural attenuation or transport processes in groundwater