502 research outputs found

    California Water Reallocation: Where\u27d You Get That?

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    When thirsty, Californians often avoid going to the market for more water. Instead, they might borrow some from their rich neighbors, they might sue them or more commonly, they simply take more from users without much of a voice (e.g. the fish or future generations). These alternatives are often superior to using markets. Within markets, a surprising detail emerges – it is uncommon for farmers to fallow fields in order to sell water to another user. Rather, many water transfers are structured so sellers can have their cake and eat it too. While some of these transfers rightly bring about jealousy and criticism, they likely do facilitate efficient water use. In discussing these points, I provide a more holistic description of how water users reallocate water as well as a richer understanding of how California’s water market actually works

    California’s Flawed Surface Water Rights

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    California sprang into existence following the discovery of gold in 1848. Aside from domestic use, the first major use of water in California was in mining. The first mining consisted of placer mining of alluvial deposits in stream beds throughout the Sierra foothills. As those deposits were depleted, hydraulic mining arose, in which high-pressure jets of water were used to remove overlying earth from upland gold- bearing deposits. That type of mining, first employed in 1853, required substantial water diversions. When California entered the Union in 1850, the English common law was adopted as the “rule of decision” in courts, including the doctrine of riparian rights for surface water1 (it was also the governing doctrine in the rest of the Union). Riparian rights entitle the owner of land bordering a surface water body (“riparian” land) to use the water on his or her riparian land. This is a right to use water, not a right of ownership, and it inheres only in riparian lands. Riparian rights remain with the riparian land regardless of changes in ownership. Water under a riparian right cannot be used on nonriparian land.2 The right is shared equally among all riparians: they own access to the stream as “tenants in common.” They can divert water as long as this does not impair the rights of other riparians. No specific quantity attaches to a riparian right. If a riparian originally applied X, this does not preclude him from applying 5X later. Nonuse does not terminate the right. There is no recording of the volume diverted. No institution administers the ripar- ian right. Disputes are resolved through litigation among riparians. The riparian doctrine was logical where it originated, in a humid region with plentiful streamflow. Streamflow is treated as a common pool to be shared among all riparian landowners. But in an arid region like California, where rivers can run dry by the late summer and annual streamflow can vary by an order of magnitude, there needs to be a specific mechanism for allocating limited streamflow. The riparian right lacks this

    Empirically derived guidance for social scientists to influence environmental policy

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    Failure to stem trends of ecological disruption and associated loss of ecosystem services worldwide is partly due to the inadequate integration of the human dimension into environmental decision-making. Decision-makers need knowledge of the human dimension of resource systems and of the social consequences of decision-making if environmental management is to be effective and adaptive. Social scientists have a central role to play, but little guidance exists to help them influence decision-making processes. We distil 348 years of cumulative experience shared by 31 environmental experts across three continents into advice for social scientists seeking to increase their influence in the environmental policy arena. Results focus on the importance of process, engagement, empathy and acumen and reveal the importance of understanding and actively participating in policy processes through co-producing knowledge and building trust. The insights gained during this research might empower a science-driven cultural change in science-policy relations for the routine integration of the human dimension in environmental decision making; ultimately for an improved outlook for earth’s ecosystems and the billions of people that depend on them

    Increased oxidative metabolism following hypoxia in the type 2 diabetic heart, despite normal hypoxia signalling and metabolic adaptation

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    Hypoxia activates the hypoxia-inducible factor (HIF), promoting glycolysis and suppressing mitochondrial respiration. In the type 2 diabetic heart, glycolysis is suppressed whereas fatty acid metabolism is promoted. The diabetic heart experiences chronic hypoxia as a consequence of increased obstructive sleep apnoea and cardiovascular disease. Given the opposing metabolic effects of hypoxia and diabetes, we questioned whether diabetes affects cardiac metabolic adaptation to hypoxia. Control and type 2 diabetic rats were housed for 3 weeks in normoxia or 11% oxygen. Metabolism and function were measured in the isolated perfused heart using radiolabelled substrates. Following chronic hypoxia, both control and diabetic hearts upregulated glycolysis, lactate efflux and glycogen content and decreased fatty acid oxidation rates, with similar activation of HIF signalling pathways. However, hypoxia-induced changes were superimposed on diabetic hearts that were metabolically abnormal in normoxia, resulting in glycolytic rates 30% lower, and fatty acid oxidation 36% higher, in hypoxic diabetic hearts than hypoxic controls. Peroxisome proliferator-activated receptor α target proteins were suppressed by hypoxia, but activated by diabetes. Mitochondrial respiration in diabetic hearts was divergently activated following hypoxia compared with controls. These differences in metabolism were associated with decreased contractile recovery of the hypoxic diabetic heart following an acute hypoxic insult. In conclusion, type 2 diabetic hearts retain metabolic flexibility to adapt to hypoxia, with normal HIF signalling pathways. However, they are more dependent on oxidative metabolism following hypoxia due to abnormal normoxic metabolism, which was associated with a functional deficit in response to stress

    Role of structural dynamics at the receptor G protein interface for signal transduction

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    GPCRs catalyze GDP/GTP exchange in the α-subunit of heterotrimeric G proteins (Gαßγ) through displacement of the Gα C-terminal α5 helix, which directly connects the interface of the active receptor (R*) to the nucleotide binding pocket of G. Hydrogen-deuterium exchange mass spectrometry and kinetic analysis of R* catalysed G protein activation have suggested that displacement of α5 starts from an intermediate GDP bound complex (R*•GGDP). To elucidate the structural basis of receptor-catalysed displacement of α5, we modelled the structure of R*•GGDP. A flexible docking protocol yielded an intermediate R*•GGDP complex, with a similar overall arrangement as in the X-ray structure of the nucleotide free complex (R*•Gempty), however with the α5 C-terminus (GαCT) forming different polar contacts with R*. Starting molecular dynamics simulations of GαCT bound to R* in the intermediate position, we observe a screw-like motion, which restores the specific interactions of α5 with R* in R*•Gempty. The observed rotation of α5 by 60° is in line with experimental data. Reformation of hydrogen bonds, water expulsion and formation of hydrophobic interactions are driving forces of the α5 displacement. We conclude that the identified interactions between R* and G protein define a structural framework in which the α5 displacement promotes direct transmission of the signal from R* to the GDP binding pocket

    The modulating effect of education on semantic interference during healthy aging

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    Aging has traditionally been related to impairments in name retrieval. These impairments have usually been explained by a phonological transmission deficit hypothesis or by an inhibitory deficit hypothesis. This decline can, however, be modulated by the educational level of the sample. This study analyzed the possible role of these approaches in explaining both object and face naming impairments during aging. Older adults with low and high educational level and young adults with high educational level were asked to repeatedly name objects or famous people using the semantic-blocking paradigm. We compared naming when exemplars were presented in a semantically homogeneous or in a semantically heterogeneous context. Results revealed significantly slower rates of both face and object naming in the homogeneous context (i.e., semantic interference), with a stronger effect for face naming. Interestingly, the group of older adults with a lower educational level showed an increased semantic interference effect during face naming. These findings suggest the joint work of the two mechanisms proposed to explain age-related naming difficulties, i.e., the inhibitory deficit and the transmission deficit hypothesis. Therefore, the stronger vulnerability to semantic interference in the lower educated older adult sample would possibly point to a failure in the inhibitory mechanisms in charge of interference resolution, as proposed by the inhibitory deficit hypothesis. In addition, the fact that this interference effect was mainly restricted to face naming and not to object naming would be consistent with the increased age-related difficulties during proper name retrieval, as suggested by the transmission deficit hypothesis.This research was supported by grants PSI2013-46033-P to A.M., PSI2015-65502-C2-1-P to M.T.B., PCIN-2015-165-C02-01 to D.P., PSI2017-89324-C2-1-P to DP from the Spanish Ministry of Economy and Competitiveness (http://www.mineco.gob.es/)
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