Clinical and Immunomodulating Effects of Ketamine in Horses with Experimental Endotoxemia

Background:  Ketamine has immunomodulating effects both in vitro and in vivo during experimental endotoxemia in humans, rodents, and dogs. Hypothesis:  Subanesthetic doses of ketamine will attenuate the clinical and immunologic responses to experimental endotoxemia in horses. Animals:  Nineteen healthy mares of various breeds. Methods:  Experimental study. Horses were randomized into 2 groups: ketamine-treated horses (KET; n = 9) and saline-treated horses (SAL; n = 10). Both groups received 30 ng/kg of lipopolysaccharide (LPS, Escherichia coli, O55:B5) 1 hour after the start of a continuous rate infusion (CRI) of racemic ketamine (KET) or physiologic saline (SAL). Clinical and hematological responses were documented and plasma concentrations of tumor necrosis factor-α (TNF-α) and thromboxane B2 (TXB2) were quantified. Results:  All horses safely completed the study. The KET group exhibited transient excitation during the ketamine loading infusion (P \u3c .05) and 1 hour after discontinuation of administration (P \u3c .05). Neutrophilic leukocytosis was greater in the KET group 8 and 24 hours after administration of LPS (P \u3c .05). Minor perturbations of plasma biochemistry results were considered clinically insignificant. Plasma TNF-α and TXB2 production peaked 1.5 and 1 hours, respectively, after administration of LPS in both groups, but a significant difference between treatment groups was not demonstrated. Conclusions and Clinical Importance:  A subanesthetic ketamine CRI is well tolerated by horses. A significant effect on the clinical or immunologic response to LPS administration, as assessed by clinical observation, hematological parameters, and TNF-α and TXB2production, was not identified in healthy horses with the subanesthetic dose of racemic ketamine utilized in this study

Regional nutrient decrease drove redox stabilisation and metazoan diversification in the late Ediacaran Nama Group, Namibia

The late Ediacaran witnessed an increase in metazoan diversity and ecological complexity, marking the inception of the Cambrian Explosion. To constrain the drivers of this diversification, we combine redox and nutrient data for two shelf transects, with an inventory of biotic diversity and distribution from the Nama Group, Namibia (similar to 550 to similar to 538 Million years ago; Ma). Unstable marine redox conditions characterised all water depths in inner to outer ramp settings from similar to 550 to 547Ma, when the first skeletal metazoans appeared. However, a marked deepening of the redoxcline and a reduced frequency of anoxic incursions onto the inner to mid-ramp is recorded from similar to 547Ma onwards, with full ventilation of the outer ramp by similar to 542Ma. Phosphorus speciation data show that, whilst anoxic ferruginous conditions were initially conducive to the drawdown of bioavailable phosphorus, they also permitted a limited degree of phosphorus recycling back to the water column. A long-term decrease in nutrient delivery from continental weathering, coupled with a possible decrease in upwelling, led to the gradual ventilation of the Nama Group basins. This, in turn, further decreased anoxic recycling of bioavailable phosphorus to the water column, promoting the development of stable oxic conditions and the radiation of new mobile taxa.Peer reviewe

Adapting agricultural water use to climate change in a post-Soviet context: challenges and opportunities in southeast Kazakhstan

The convergence of climate change and post-Soviet socio-economic and institutional transformations has been underexplored so far, as have the consequences of such convergence on crop agriculture in Central Asia. This paper provides a place-based analysis of constraints and opportunities for adaptation to climate change, with a specific focus on water use, in two districts in southeast Kazakhstan. Data were collected by 2 multi-stakeholder participatory workshops, 21 semi-structured in-depth interviews, and secondary statistical data. The present-day agricultural system is characterised by enduring Soviet-era management structures, but without state inputs that previously sustained agricultural productivity. Low margins of profitability on many privatised farms mean that attempts to implement integrated water management have produced water users associations unable to maintain and upgrade a deteriorating irrigation infrastructure. Although actors engage in tactical adaptation measures, necessary structural adaptation of the irrigation system remains difficult without significant public or private investments. Market-based water management models have been translated ambiguously to this region, which fails to encourage efficient water use and hinders adaptation to water stress. In addition, a mutual interdependence of informal networks and formal institutions characterises both state governance and everyday life in Kazakhstan. Such interdependence simultaneously facilitates operational and tactical adaptation, but hinders structural adaptation, as informal networks exist as a parallel system that achieves substantive outcomes while perpetuating the inertia and incapacity of the state bureaucracy. This article has relevance for critical understanding of integrated water management in practice and adaptation to climate change in post-Soviet institutional settings more broadly

After 35 years of rebound research in economics : where do we stand?

The phenomenon of rebound effects has sparked considerable academic, policy and press debate over the effectiveness of energy efficiency policy. In recent years, a plethora of theoretical and empirical rebound studies have been published, fueling the discussion but also raising further issues and unanswered questions. At the same time it seems that there is a lack of understanding of how to treat and measure central aspects such as potential energy savings expected and the energy services impacted by an efficiency increase. Moreover, there is a lack of clarity and understanding in how we move from micro to macro levels of analysis and reporting. In terms of policy understanding the crux of the problem is that there is no such thing as a simple formula for all aspects of rebound. The aim of this chapter is to clarify the correct perspective on how to look at economic dimensions of re-bound, with particular attention to what policy-makers can do with rebound analysis and findings. Further, we attempt to synthesize existing rebound taxonomies and to provide, in a concise manner, the economic rebound mechanisms at work. We then approach the rebound theme from both micro and macro perspectives, before bringing the two angles together. Overall, we argue that both policymakers and re-searchers need to be aware that rebound is an issue that ought to be tackled at multiple levels and that there are policy trade-offs, especially between economic growth and ecological sustainability. This may be resolved at least to a certain extent by welfare considerations

Energy conservation more effective with rebound policy

This article sketches the problem of indirect energy use effects, also known as rebound, of energy conservation. There is widespread support for energy conservation, especially when it is voluntary, as this seems a cheap way to realize environmental and energy-climate goals. However, this overlooks the phenomenon of rebound. The topic of energy rebound has mainly attracted attention from energy analysts, but has been surprisingly neglected in environmental economics, even though economists generally are concerned with indirect or economy-wide impacts of technical change and policies. This paper presents definitions and interpretations of energy and environmental rebound, as well as four fundamental reasons for the existence of the rebound phenomenon. It further offers the most complete list of rebound pathways or mechanisms available in the literature. In addition, it discusses empirical estimates of rebound and addresses the implications of uncertainties and difficulties in assessing rebound. Suggestions are offered for strategies and public policies to contain rebound. It is advised that rebound evaluation is an essential part of environmental policy and project assessments. As opposed to earlier studies, this paper stresses the relevance of the distinction between energy conservation resulting from autonomous demand changes and from efficiency improvements in technology/equipment. In addition, it argues that rebound is especially relevant for developing countries. © 2010 The Author(s)

Using Incentives and Social Information to Promote Energy Conservation Behavior

Improving the efficiency in the domestic energy consumption has become a showpiece of how behavioral economics can be applied to the field of environmental economics. This study builds upon the literature by providing subjects with individual and social energy performance information at group level in a controlled field experiment setting. We aim to test whether extrinsic incentives accentuate or crowd out the intrinsic motivation to save energy and how heterogeneity in environmental attitudes also impacts on electricity conservation. Besides, we test for the persistence of energy-saving habits after the information is removed. Results suggest that the provision of individual feedback and social information increase energy conserving behavior, with this being most effective among those who signaled in a previous stage preferences for pro-environmental and sustainable living. However, treatment variations indicate that subjects overall fail to maintain “good habits” once the intervention stops, with exception of pro-environmental subjects who continue to consume less electricity in the post-intervention phase. Furthermore, our findings indicate that rewarding groups in a competitive environment may create perverse long-run effects. While providing individual and social information could improve both consumer welfare and energy demand forecasting, the timescale, frequency, and mechanism undertaken require careful scrutiny and planning if these potential benefits are to be maximized and undesirable side effects prevented