Long Run Projections for Climate Change Scenarios

The prediction of future temperature increases depends critically on the projections of future greenhouse gas emissions. Yet there is a vigorous debate about how these projections should be undertaken and how reasonable is the approach of the Special Report on Emissions Scenarios (SRES) published by the Intergovernmental Panel on Climate Change (IPCC) which forms the basis of nearly all recent analyses of the impacts of climate change. In particular there has been significant criticism by Ian Castles and David Henderson regarding the plausibility of some scenarios. This paper explores a range of methodological issues surrounding projecting greenhouse emissions over the next century. It points out that understanding future emissions, requires a framework that deals with the sources of economic growth and allows for endogenous structural change. It also explores the role of “convergence” assumptions and the debate regarding the use of purchasing power parity (PPP) measurement versus market exchange rate (MER) measurement of income differentials. Using the G-Cubed multi-country model we show that emission projections based on convergence assumptions defined in MER terms, are 40% higher by 2100 than emissions generated using a PPP comparison of income differentials between economies. This result illustrates the argument by Castles and Henderson that the use of MER convergence assumptions will likely overestimate emissions projections, taking many other issues as given. However it is not clear what this means for the SRES projections given that it might be argued that in some models in the SRES, there could be endogenous changes in technology that will offset this result. We do not have access to those models to explore this issue and can only show what this particular assumption implies in the G-Cubed model. It is also ambiguous exactly what was done in the SRES report regarding convergence assumptions in some scenarios. Either way these results do not imply that climate change is not an issue but that there is a great deal of uncertainty about future climate projections and it is very unhelpful to presume that all futures are equally likely. In order to deal with this we also propose as a better guide to policymakers a methodology that calculates probabilities for future projections rather than the approach of SRES which is based on storylines without any assessment of plausibility. It is unfortunate that some analyses of the impacts of future climate change are based on the extreme outliers from the SRES without any understanding of the probability of these outcomes. This alternative approach could be done using the economic approach proposed in the G-Cubed model as outlined in this paper, or it could be done with the existing range of SRES scenarios to better inform the debate on likely future greenhouse scenarios.Climate change, Kyoto Protocol, G-Cubed, model, projections, SRES, PPP versus MER

Polybridge Season 3: Ecosystem effects of polychaete-assisted sand filters

This study is an extension of research undertaken in the first two seasons of the Polybridge Project (2013-2016: for results see Palmer et al., 2016), which sought to investigate operational aspects of polychaete-assisted sand filters (PASF) when deployed for scaled prawn farm recirculation at the Bribie Island Research Centre (BIRC). The aims of the present work were to assess its functionality with increased organic loading rates provided by higher prawn stocking densities than previously trialled, and to assess the ecological effects on this integrated farming system when using PASF to initially fill ponds for a range of biosecurity purposes. Using prawn postlarval stocking densities in excess of 44 m-2, prawn production of up to 12 tonnes ha-1 was achieved without discharge of any wastewater during the production season (2015-16). However, the average production for the two ponds was 9.4 tonnes ha-1, which was lower than in the previous season (9.9 tonnes ha-1 in 2014/15) which used a lower prawn stocking density (37.5 postlarvae m-2). The prawns and worms produced were again healthy and of high commercial quality and value, but slower prawn growth (particularly after 140 d) and lower worm survival limited overall production in the fully-recirculated system. There were also several concerning aspects to this closed-system approach that need to be highlighted. Firstly, nutrient levels in the pond waters rose to particularly high levels, and some of the more toxic parameters, such as ammonia, reached critical levels that could be considered dangerous for routine prawn culture operations. Worm production in the PASF beds also suffered from the very rich wastewaters in the integrated system, and the capacity of PASF to filter water via percolation was limited by excessive sand clogging and a build-up of organic matter on the upper surface of the sand beds. The resultant excessive anoxic conditions created in the sand beds appeared to reduce worm productivity which, in turn, reduced their sand cleansing actions, for an overall lower functionality in terms of nutrient (and particularly nitrogen) removal rates. Alternatively, within the confines of the overall study, there were no significant deleterious effects on worm production or nutrient removal efficacies from using the PASF beds to initially fill the prawn production pond. The apparent effect of this on pond plankton communities was: 1) to slow the development of copepod populations; and 2) change the assemblage of algal species in the first few weeks after filling. This slower development of natural feed organisms in the PASF-filled pond may have provided lower survival of the particularly-young (PL 13) prawn seedstock used to stock the pond. Importantly however, there may be several potential remedies to this issue. These include management for a longer period for bloom development after fill and before stocking, and assuming a greater reliance on artificial feeds more suited to small prawns. As expected, this pond-fill strategy appeared to beneficially help exclude some problematic algal species, and greatly reduced barnacle fouling, though tube worm fouling did not appear overly affected. The project successfully demonstrated a third successive season of zero-water discharge from an integrated prawn/ worm production system, though ultimately, the water in ponds with some residual nutrients were discharged. The expansion of prawn farming in Australia is limited by nutrient discharge issues, and biosecurity measures are also of increasing interest to this industry. In this legacy project, polychaete-assisted sand filters are further demonstrated to hold potential for biosecurity controls whilst minimising nutrient discharge

Protocol for a randomised control trial of methylnaltrexone for the treatment of opioid-induced constipation and gastrointestinal stasis in intensive care patients (MOTION)

Gastrointestinal dysmotility and constipation are common problems in intensive care patients. The majority of critical care patients are sedated with opioids to facilitate tolerance of endotracheal tubes and mechanical ventilation, which inhibit gastrointestinal motility and lead to adverse outcomes. Methylnaltrexone is a peripheral opioid antagonist that does not cross the blood-brain barrier and can reverse the peripheral side effects of opioids without affecting the desired central properties. This trial will investigate whether methylnaltrexone can reverse opioid-induced constipation and gastrointestinal dysmotility.This is a single-centre, multisite, double-blind, randomised, placebo-controlled trial. 84 patients will be recruited from 4 intensive care units (ICUs) within Imperial College Healthcare NHS Trust. Patients will receive intravenous methylnaltrexone or placebo on a daily basis if they are receiving opioid infusion to facilitate mechanical ventilation and have not opened their bowels for 48 hours. All patients will receive standard laxatives as per the clinical ICU bowel protocol prior to randomisation. The primary outcome of the trial will be time to significant rescue-free laxation following randomisation. Secondary outcomes will include tolerance of enteral feed, gastric residual volumes, incidence of pneumonia, blood stream and Clostridium difficile infection, and any reversal of central opioid effects.The trial protocol, the patient/legal representative information sheets and consent forms have been reviewed and approved by the Harrow Research Ethics Committee (REC Reference 14/LO/2004). An independent Trial Steering Committee and Data Monitoring Committee are in place, with patient representation. On completion, the trial results will be published in peer-reviewed journals and presented at national and international scientific meetings.2014-004687-37; Pre-results

Variable X-ray Absorption in the Seyfert 2 Galaxy Mrk 348

We present RXTE monitoring observations of the Seyfert 2 galaxy Mrk 348 spanning a 6 month period. The time-averaged spectrum in the 3-20 keV band shows many features characteristic of a Compton-thin Seyfert 2 galaxy, namely a hard underlying power-law continuum (photon index = 1.8) with heavy soft X-ray absorption (N_h ~ 10^23 cm^-2) plus measureable iron line emission (equivalent width ~ 100 eV) and, at high energy, evidence for a reflection component (R < 1). During the first half of the monitoring period the X-ray continuum flux from Mrk 348 remained relatively steady. However this was followed by a significant brightening of the source (by roughly a factor of 4) with the fastest change corresponding to a doubling of its X-ray flux on a timescale of about 20 days. The flux increase was accompanied by a marked softening of X-ray spectrum most likely attributable to a factor 3 decline in the intrinsic line-of-sight column density. In contrast the iron line and the reflection components showed no evidence of variability. These observations suggest a scenario in which the central X-ray source is surrounded by a patchy distribution of absorbing material located within about a light-week of the nucleus of Mrk 348. The random movement of individual clouds within the absorbing screen, across our line of sight, produces substantial temporal variations in the measured column density on timescales of weeks to months and gives rise to the observed X-ray spectral variability. However, as viewed from the nucleus the global coverage and typical thickness of the cloud layer remains relatively constant.Comment: 19 pages, 3 figures Accepted for publication in the Astrophysical Journa

Lessons learned from the global orthopaedic registry: study design, current practice patterns, and future directions

The previous articles in this supplement have recounted, in detail, a number of the findings of the Global Orthopaedic Registry (GLORY) and placed them within the context of current knowl-edge regarding anticoagulation in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). Furthermore, because of the multinational nature of GLORY, we have been able to provide a preliminary view of some of the geographical differences in orthopedic practices that occur

Mucosal Vaccination with a Self-Adjuvanted Lipopeptide Is Immunogenic and Protective against Mycobacterium tuberculosis

Tuberculosis (TB) remains a staggering burden on global public health. Novel preventative tools are desperately needed to reach the targets of the WHO post-2015 End-TB Strategy. Peptide or protein-based subunit vaccines offer potential as safe and effective generators of protection, and enhancement of local pulmonary immunity may be achieved by mucosal delivery. We describe the synthesis of a novel subunit vaccine via native chemical ligation. Two immunogenic epitopes, ESAT61−20 and TB10.43−11 from Mycobacterium tuberculosis (Mtb), were covalently conjugated to the TLR2-ligand Pam2Cys to generate a self-adjuvanting lipopeptide vaccine. When administered mucosally to mice, the vaccine enhanced pulmonary immunogenicity, inducing strong Th17 responses in the lungs and multifunctional peripheral T-lymphocytes. Mucosal, but not peripheral vaccination, provided substantial protection against Mtb infection, emphasizing the importance of delivery route for optimal efficacy.NHMR

Biogeography of a plant invasion: drivers of latitudinal variation in enemy release

© 2016 John Wiley & Sons Ltd Aim: The relationship between herbivory and latitude may differ between native and invasive plant taxa, which can generate biogeographical heterogeneity in the strength of enemy release. Our aim was to compare latitudinal gradients in herbivory between native and invasive plants and investigate whether gradients are driven by local adaptation or phenotypic plasticity. Location: North America. Methods: Using sympatric native and invasive lineages of the wetland grass Phragmites australis and the specialist gall-fly Lipara rufitarsis, we conducted a field survey to examine whether the relationship between herbivory (the proportion of stems galled) and latitude was parallel between lineages. In a subsequent common garden experiment, we assessed whether latitudinal gradients in herbivory were genetically based or driven by phenotypic plasticity. Results: In the field, L. rufitarsis herbivory on the native P. australis lineage increased from 27% of stems galled in southern populations (36.5°) to 37% in northern populations (43.6°), whereas there was no relationship for the invasive lineage. Similar relationships were evident in the common garden experiment, indicating a genetic basis to latitudinal variation in herbivory. Moreover, the invasive lineage suffered five times less herbivory than the native lineage on average, supporting the enemy release hypothesis. However, a genetic basis to this pattern was absent in the common garden experiment, suggesting that local environmental conditions were responsible for the enemy release observed in nature. Specifically, stem height, diameter and density during the L. rufitarsis oviposition period appeared to be important drivers of herbivory. Main conclusions: Non-parallel gradients in herbivory may help explain the equivocal results of other studies that examine enemy release and biotic resistance at local scales, and can be an important mechanism promoting biogeographical variation in invasion success. We suggest that these latitudinal patterns in herbivory and other species interactions are likely to be a common phenomenon across a range of invaded systems

Oleophobic composite films based on multi-layer graphitic scaffolding

A new oleophobic composite material synthesised by utilising plasma-exfoliated multi-layered graphitic (MLG) material as scaffolding is presented herein. The composite consisted of a polyelectrolyte/fluorosurfactant complex derived from polydiallyldimethylammonium chloride (PDDA) and sodium perfluorooctanoate (PFO) and was used to prepare free-standing MLG composite films