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

Development of Iron Speciation Reference Materials for Palaeoredox Analysis

The development and application of geochemical techniques to identify redox conditions in modern and ancient aquatic environments has intensified over recent years. Iron (Fe) speciation has emerged as one of the most widely used procedures to distinguish different redox regimes in both the water column and sediments, and is the main technique used to identify oxic, ferruginous (anoxic, Fe(II) containing) and euxinic (anoxic, sulfidic) water column conditions. However, an international sediment reference material has never been developed. This has led to concern over the consistency of results published by the many laboratories that now utilise the technique. Here, we report an interlaboratory comparison of four Fe speciation reference materials for palaeoredox analysis, which span a range of compositions and reflect deposition under different redox conditions. We provide an update of extraction techniques used in Fe speciation, and assess the effects of both test portion mass, and the use of different analytical procedures, on the quantification of different Fe fractions in sedimentary rocks. While atomic adsorption spectroscopy and inductively coupled plasma‐optical emission spectrometry produced comparable Fe measurements for all extraction stages, the use of ferrozine consistently underestimated Fe in the extraction step targeting mixed ferrous‐ferric minerals such as magnetite. We therefore suggest that the use of ferrozine is discontinued for this Fe pool. Finally, we report the combined data of four independent Fe speciation laboratories to characterise the Fe speciation composition of the reference materials. These reference materials are available to the community to provide an essential validation of in‐house Fe speciation measurements

Development of Iron Speciation Reference Materials for Palaeoredox Analysis

The development and application of geochemical techniques to identify redox conditions in modern and ancient aquatic environments has intensified over recent years. Iron (Fe) speciation has emerged as one of the most widely used procedures to distinguish different redox regimes in both the water column and sediments, and is the main technique used to identify oxic, ferruginous (anoxic, Fe(II) containing) and euxinic (anoxic, sulfidic) water column conditions. However, an international sediment reference material has never been developed. This has led to concern over the consistency of results published by the many laboratories that now utilise the technique. Here, we report an interlaboratory comparison of four Fe speciation reference materials for palaeoredox analysis, which span a range of compositions and reflect deposition under different redox conditions. We provide an update of extraction techniques used in Fe speciation and assess the effects of both test portion mass, and the use of different analytical procedures, on the quantification of different Fe fractions in sedimentary rocks. While atomic absorption spectroscopy and inductively coupled plasma‐optical emission spectrometry produced comparable Fe measurements for all extraction stages, the use of ferrozine consistently underestimated Fe in the extraction step targeting mixed ferrous–ferric minerals such as magnetite. We therefore suggest that the use of ferrozine is discontinued for this Fe pool. Finally, we report the combined data of four independent Fe speciation laboratories to characterise the Fe speciation composition of the reference materials. These reference materials are available to the community to provide an essential validation of in‐house Fe speciation measurements

Real-time, appliance-level electricity use feedback system: How to engage users?

Engage is a rapidly deployable, retrofit energy monitoring system developed for direct support of a novel energy use behavior investigation and a large-scale deployment in campus apartments. We describe the end-to-end system and report results related to web dashboard engagement during a year-long experiment. The objective was to determine user engagement with real-time and easily accessible information about personal energy consumption. Leveraging low-cost components, this system was designed to measure separately appliance plug load, heating and cooling, and lighting electrical load in dense-occupancy building environments. We developed and used an open source technology for measurement of plug load and developed signal processing algorithms to significantly improve measurement accuracy. We also developed proxy sensors to measure heating and cooling and lighting. Our results indicate that 90% of the dashboard activity was undertaken by 50% of the participants and that website engagement was more likely in mid-day and more effective in combination with email reminders. Energy conservation was achieved when combining the dashboard with public information about energy consumption. © 2013 Elsevier B.V. All rights reserved

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