Limitations of integrated assessment models of climate change

The integrated assessment models (IAMs) that economists use to analyze the expected costs and benefits of climate policies frequently suggest that the “optimal” policy is to go slowly and to do relatively little in the near term to reduce greenhouse gas emissions. We trace this finding to the contestable assumptions and limitations of IAMs. For example, they typically discount future impacts from climate change at relatively high rates. This practice may be appropriate for short-term financial decisions but its extension to intergenerational environmental issues rests on several empirically and philosophically controversial hypotheses. IAMs also assign monetary values to the benefits of climate mitigation on the basis of incomplete information and sometimes speculative judgments concerning the monetary worth of human lives and ecosystems, while downplaying scientific uncertainty about the extent of expected damages. In addition, IAMs may exaggerate mitigation costs by failing to reflect the socially determined, path-dependent nature of technical change and ignoring the potential savings from reduced energy utilization and other opportunities for innovation. A better approach to climate policy, drawing on recent research on the economics of uncertainty, would reframe the problem as buying insurance against catastrophic, low-probability events. Policy decisions should be based on a judgment concerning the maximum tolerable increase in temperature and/or carbon dioxide levels given the state of scientific understanding. The appropriate role for economists would then be to determine the least-cost global strategy to achieve that target. While this remains a demanding and complex problem, it is far more tractable and epistemically defensible than the cost-benefit comparisons attempted by most IAMs

Mechanical strain causes adaptive change in bronchial fibroblasts enhancing profibrotic and inflammatory responses

Asthma is characterized by periodic episodes of bronchoconstriction and reversible airway obstruction; these symptoms are attributable to a number of factors including increased mass and reactivity of bronchial smooth muscle and extracellular matrix (ECM) in asthmatic airways. Literature has suggested changes in cell responses and signaling can be elicited via modulation of mechanical stress acting upon them, potentially affecting the microenvironment of the cell. In this study, we hypothesized that mechanical strain directly affects the (myo)fibroblast phenotype in asthma. Therefore, we characterized responses of bronchial fibroblasts, from 6 normal and 11 asthmatic non-smoking volunteers, exposed to cyclical mechanical strain using flexible silastic membranes. Samples were analyzed for proteoglycans, ?-smooth muscle actin (?SMA), collagens I and III, matrix metalloproteinase (MMP) 2 &amp; 9 and interleukin-8 (IL-8) by qRT-PCR, Western blot, zymography and ELISA. Mechanical strain caused a decrease in ?SMA mRNA but no change in either ?SMA protein or proteoglycan expression. In contrast the inflammatory mediator IL-8, MMPs and interstitial collagens were increased at both the transcriptional and protein level. The results demonstrate an adaptive response of bronchial fibroblasts to mechanical strain, irrespective of donor. The adaptation involves cytoskeletal rearrangement, matrix remodelling and inflammatory cytokine release. These results suggest that mechanical strain could contribute to disease progression in asthma by promoting inflammation and remodelling responses.<br/

Participatory politics, environmental journalism and newspaper campaigns

This is an Author's Accepted Manuscript of an article published in Journalism Studies, 13(2), 210 - 225, 2012, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/1461670X.2011.646398.This article explores the extent to which approaches to participatory politics might offer a more useful alternative to understanding the role of environmental journalism in a society where the old certainties have collapsed, only to be replaced by acute uncertainty. This uncertainty not only generates acute public anxiety about risks, it has also undermined confidence in the validity of long-standing premises about the ideal role of the media in society and journalistic professionalism. The consequence, this article argues, is that aspirations of objective reportage are outdated and ill-equipped to deal with many of the new risk stories environmental journalism covers. It is not a redrawing of boundaries that is needed but a wholesale relocation of our frameworks into approaches better suited to the socio-political conditions and uncertainties of late modernity. The exploration of participatory approaches is an attempt to suggest one way this might be done

Transforming growth factor-beta promotes rhinovirus replication in bronchial epithelial cells by suppressing the innate immune response

Rhinovirus (RV) infection is a major cause of asthma exacerbations which may be due to a deficient innate immune response in the bronchial epithelium. We hypothesized that the pleiotropic cytokine, TGF-?, influences interferon (IFN) production by primary bronchial epithelial cells (PBECs) following RV infection. Exogenous TGF-?(2) increased RV replication and decreased IFN protein secretion in response to RV or double-stranded RNA (dsRNA). Conversely, neutralizing TGF-? antibodies decreased RV replication and increased IFN expression in response to RV or dsRNA. Endogenous TGF-?(2) levels were higher in conditioned media of PBECs from asthmatic donors and the suppressive effect of anti-TGF-? on RV replication was significantly greater in these cells. Basal SMAD-2 activation was reduced when asthmatic PBECs were treated with anti-TGF-? and this was accompanied by suppression of SOCS-1 and SOCS-3 expression. Our results suggest that endogenous TGF-? contributes to a suppressed IFN response to RV infection possibly via SOCS-1 and SOCS-3

Expression of CD44 and integrins in bronchial mucosa of normal and mildly asthmatic subjects

We have investigated the expression of cell surface markers and leucocyte cell adhesion molecules by immunohistochemistry in bronchial biopsies from 10 mild atopic asthmatics and 8 normal, nonatopic subjects. Significantly increased numbers of eosinophils (p<0.01) were evident in the bronchial submucosa of asthmatic subjects. In epithelium there were more CD44+ (p<0.02) and lymphocyte function-associated antigen-1 (LFA-1)+ (p<0.06) leucocytes in asthmatics than in normal subjects. Bronchial epithelial cells stained positively with anti-CD44 monoclonal antibodies (moAb) in both groups; however, when the staining was expressed as percentage of the total basement membrane, a considerable and highly significant increase was observed in the asthmatics (median 80 vs 22%, p=0.003). Few leucocytes were positive for very late activation antigen (VLA)-1, VLA-2 and VLA-4. The moAb for VLA-6 stained the basement membrane of the bronchial epithelium; while intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were constitutively expressed in endothelium. A positive correlation was found between LFA-1+ cells and activated eosinophils (EG2+) in the submucosa (p<0.005; r(s)=0.80). We conclude that even in mild asthma there is evidence of increased expression of cell surface ligands, and suggest that adhesive mechanisms play a role both in cell recruitment and disease activity.peer-reviewe

Soluble ADAM33 initiates airway remodeling to promote susceptibility for allergic asthma in early life

Asthma is a chronic inflammatory airways disease that usually begins in early life and involves gene-environment interactions. Although most asthma exhibits allergic inflammation, many allergic individuals do not have asthma. Here, we report how the asthma gene A Disintegrin and Metalloprotease (ADAM)33, acts as local tissue susceptibility gene that promotes allergic asthma. We show that enzymatically active soluble (s)ADAM33 is increased in asthmatic airways and plays a role in airway remodeling, independent of inflammation. Furthermore, remodeling and inflammation are both suppressed in Adam33 null mice after allergen challenge. When induced in utero or added ex vivo, sADAM33 causes structural remodeling of the airways, which enhances post-natal airway eosinophilia and bronchial hyperresponsiveness following sub-threshold challenge with an aeroallergen. This substantial gene-environment interaction helps to explain the end-organ expression of allergic asthma in genetically susceptible individuals. Finally, we show that sADAM33-induced airway remodeling is reversible, highlighting the therapeutic potential of targeting ADAM33 in asthma

STIS UV spectroscopy of early B supergiants in M31

We analyze STIS spectra in the 1150-1700 Angstrom wavelength range obtained for six early B supergiants in the neighboring galaxy M31. Because of their likely high (nearly solar) abundance, these stars were originally chosen to be directly comparable to their Galactic counterparts, and represent a much-needed addition to our current sample of B-type supergiants, in our efforts to study the dependence of the Wind Momentum-Luminosity Relationship on spectral type and metallicity. As a first step to determine wind momenta we fit the P-Cygni profiles of the resonance lines of N V, Si IV and C IV with standard methods, and derive terminal velocities for all of the STIS targets. From these lines we also derive ionic stellar wind column densities. Our results are compared with those obtained previously in Galactic supergiants, and confirm earlier claims of `normal' wind line intensities and terminal velocities in M31. For half of the sample we find evidence for an enhanced maximum turbulent velocity when compared to Galactic counterparts.Comment: 15 pages, 9 figures, 2 tables. Accepted for publication in The Astrophysical Journa

X-ray Emission from Nitrogen-Type Wolf-Rayet Stars

We summarize new X-ray detections of four nitrogen-type Wolf-Rayet (WR) stars obtained in a limited survey aimed at establishing the X-ray properties of WN stars across their full range of spectral subtypes. None of the detected stars is so far known to be a close binary. We report Chandra detections of WR 2 (WN2), WR 18 (WN4), and WR 134 (WN6), and an XMM-Newton detection of WR79a (WN9ha). These observations clearly demonstrate that both WNE and WNL stars are X-ray sources. We also discuss Chandra archive detections of the WN6h stars WR 20b, WR 24, and WR 136 and ROSAT non-detections of WR 16 (WN8h) and WR 78 (WN7h). The X-ray spectra of all WN detections show prominent emission lines and an admixture of cool (kT 2 keV) plasma. The hotter plasma is not predicted by radiative wind shock models and other as yet unidentified mechanisms are at work. Most stars show X-ray absorption in excess of that expected from visual extinction (Av), likely due to their strong winds or cold circumstellar gas. Existing data suggest a falloff in X-ray luminosity toward later WN7-9 subtypes, which have higher Lbol but slower, denser winds than WN2-6 stars. This provides a clue that wind properties may be a more crucial factor in determining emergent X-ray emission levels than bolometric luminosity.Comment: 42 pages, 5 tables, 10 figure

Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity

Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria