298 research outputs found
An assessment of lessons learned in the communication and dissemination of emerging scientific issues to environmental policymakers. Part 1: Comprehensive Report
The relationship between science and policy is often seen as difficult. Yet from climate change to food security, many of the biggest challenges facing the world today rely upon effective policy making, based upon the best science and evidence. We need to make sure that we have established the right level of communication and relationship between these two groups. This research project sets out to look at that communication process: to examine closely the communications involved in real-life science-to-policy case studies and to identify the lessons from the past that can help us deal with scientific issues that are emerging now and those that will emerge in the future
Comparison of aromatic hydrocarbon measurements made by PTR-MS, DOAS and GC-FID during the MCMA 2003 Field Experiment
A comparison of aromatic hydrocarbon measurements is reported for the CENICA supersite in the district of Iztapalapa during the Mexico City Metropolitan Area field experiment in April 2003 (MCMA 2003). Data from three different measurement methods were compared: a Proton Transfer Reaction Mass Spectrometer (PTR-MS), long path measurements using a UV Differential Optical Absorption Spectrometer (DOAS), and Gas Chromatography-Flame Ionization analysis (GC-FID) of canister samples. The principle focus was on the comparison between PTR-MS and DOAS data. Lab tests established that the PTR-MS and DOAS calibrations were consistent for a suite of aromatic compounds including benzene, toluene, p-xylene, ethylbenzene, 1,2,4-trimethylbenzene, phenol and styrene. The point sampling measurements by the PTR-MS and GC-FID showed good correlations (r=0.6), and were in reasonable agreement for toluene, C2-alkylbenzenes and C3-alkylbenzenes. The PTR-MS benzene data were consistently high, indicating interference from ethylbenzene fragmentation for the 145 Td drift field intensity used in the experiment. Correlations between the open-path data measured at 16-m height over a 860-m path length (retroreflector in 430 m distance), and the point measurements collected at 37-m sampling height were best for benzene (r=0.61), and reasonably good for toluene, C2-alkylbenzenes, naphthalene, styrene, cresols and phenol (r>0.5). There was good agreement between DOAS and PTR-MS measurements of benzene after correction for the PTR-MS ethylbenzene interference. Mixing ratios measured by DOAS were on average a factor of 1.7 times greater than the PTR-MS data for toluene, C2-alkylbenzenes, naphthalene and styrene. The level of agreement for the toluene data displayed a modest dependence on wind direction, establishing that spatial gradients – horizontal, vertical, or both – in toluene mixing ratios were significant, and up to a factor of 2 despite the fact that all measurements were conducted above roof level. Our analysis highlights a potential problem in defining a VOC sampling strategy that is meaningful for the comparison with photochemical transport models: meaningful measurements require a spatial fetch that is comparable to the grid cell size of models, which is typically a few 10 km2. Long-path DOAS measurements inherently average over a larger spatial scale than point measurements. The spatial representativeness can be further increased if observations are conducted outside the surface roughness sublayer, which might require measurements at altitudes as high as 10 s of metres above roof level.Alexander von Humboldt-Stiftung (Feodor Lynen fellowship)Henry & Camille Dreyfus Foundation (Postdoctral Fellowship in Environmental Chemistry
Pre-Congestion Notification marking
Pre-Congestion Notification (PCN) builds on the concepts of RFC 3168, "The addition of Explicit Congestion Notification to IP". However, Pre-Congestion Notification aims at providing notification before any congestion actually occurs. Pre-Congestion Notification is applied to \ud
real-time flows (such as voice, video and multimedia streaming) in DiffServ networks. As described in [CL-DEPLOY], it enables "pre" congestion control through two procedures, flow admission control and flow pre-emption. The draft proposes algorithms that determine when a \ud
PCN-enabled router writes Admission Marking and Pre-emption Marking in a packet header, depending on the traffic level. The draft also proposes how to encode these markings. We present simulation results with PCN working in an edge-to-edge scenario using the marking algorithms described. Other marking algorithms will be investigated in the future. \u
Being alone or becoming lonely? The complexity of portraying ‘unaccompanied children’ as being alone in Sweden
Recommended from our members
Asian outflow and trans-Pacific transport of carbon monoxide and ozone pollution: An integrated satellite, aircraft, and model perspective
Satellite observations of carbon monoxide (CO) from the Measurements of Pollution in the Troposphere (MOPITT) instrument are combined with measurements from the Transport and Chemical Evolution Over the Pacific (TRACE-P) aircraft mission over the northwest Pacific and with a global three-dimensional chemical transport model (GEOS-CHEM) to quantify Asian pollution outflow and its trans-Pacific transport during spring 2001. Global CO column distributions in MOPITT and GEOS-CHEM are highly correlated (R2 = 0.87), with no significant model bias. The largest regional bias is over Southeast Asia, where the model is 18% too high. A 60% decrease of regional biomass burning emissions in the model (to 39 Tg yr−1) would correct the discrepancy; this result is consistent with TRACE-P observations. MOPITT and TRACE-P also give consistent constraints on the Chinese source of CO from fuel combustion (181 Tg CO yr−1). Four major events of trans-Pacific transport of Asian pollution in spring 2001 were seen by MOPITT, in situ platforms, and GEOS-CHEM. One of them was sampled by TRACE-P (26–27 February) as a succession of pollution layers over the northeast Pacific. These layers all originated from one single event of Asian outflow that split into northern and southern plumes over the central Pacific. The northern plume (sampled at 6–8 km off California) had no ozone enhancement. The southern subsiding plume (sampled at 2–4 km west of Hawaii) contained a 8–17 ppbv ozone enhancement, driven by decomposition of peroxyacetylnitrate (PAN) to nitrogen oxides (NOx). This result suggests that PAN decomposition in trans-Pacific pollution plumes subsiding over the United States could lead to significant enhancements of surface ozone
Estrogen Receptor-Beta Gene Polymorphism in women with Breast Cancer at the Imam Khomeini Hospital Complex, Iran
ER-alpha and ER-beta genes have been proven to play a significant role in breast cancer. Epidemiologic studies have revealed that age-incidence patterns of breast cancer in Middle East differ from those in the Western countries. Two selected coding regions in the ER-β gene (exons 3 and 7) were scanned in Iranian women with breast cancer (150) and in healthy individuals (147). PCR single-strand conformation polymorphism was performed. A site of silent single nucleotide polymorphism was found only on exon 7. The SNP was found only in breast cancer patients (5.7%) (χ2 = 17.122, P = 0.01). Codon 392 (C1176G) of allele 1 was found to have direct association with the occurrence of lymph node metastasis. Our data suggest that ER-β polymorphism in exon 7 codon 392 (C1176G) is correlated with various aspects of breast cancer and lymph node metastasis in our group of patients
Critical, engaged and change-oriented scholarship in environmental communication. Six methodological dilemmas to think with
This is the final version. Available from Taylor & Francis via the DOI in this record. While calls for critical, engaged and change-oriented scholarship in environmental communication (EC) abound, few articles discuss what this may practically entail. With this article, we aim to contribute to a discussion in EC about the methodological implications of such scholarship. Based on our combined experience in EC research and drawing from a variety of academic fields, we describe six methodological dilemmas that we encounter in our research practice and that we believe are inherent to such scholarship. These dilemmas are (1) grasping communication; (2) representing others; (3) involving people in research; (4) co-producing knowledge; (5) engaging critically; and (6) relating to conflict. This article does not offer solutions to these complex dilemmas. Rather, our dilemma descriptions are meant to help researchers think through methodological issues in critical, engaged and change-oriented EC research. The article also helps to translate the dilemmas to the reality of research projects through a set of questions, aimed to support a sensitivity to, and understanding of, the dilemmas in context.Svenska Forskningsrådet FormasVINNOV
Free exopolysaccharide from Mycoplasma mycoides subsp. mycoides possesses anti-inflammatory properties
In this study we explored the immunomodulatory properties of highly purified free galactan, the soluble exopolysaccharide secreted by Mycoplasma mycoides subsp. mycoides (Mmm). Galactan was shown to bind to TLR2 but not TLR4 using HEK293 reporter cells and to induce the production of the anti-inflammatory cytokine IL-10 in bovine macrophages, whereas low IL-12p40 and no TNF-α, both pro-inflammatory cytokines, were induced in these cells. In addition, pre-treatment of macrophages with galactan substantially reduced lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines TNF- and IL-12p40 while increasing LPS-induced secretion of immunosuppressive IL-10. Also, galactan did not activate naïve lymphocytes and induced only low production of the Th1 cytokine IFN-γ in Mmm-experienced lymphocytes. Finally, galactan triggered weak recall proliferation of CD4+ T lymphocytes from contagious bovine pleuropneumonia-infected animals despite having a positive effect on the expression of co-stimulatory molecules on macrophages. All together, these results suggest that galactan possesses anti-inflammatory properties and potentially provides Mmm with a mechanism to evade host innate and adaptive cell-mediated immune responses. (Résumé d'auteur
- …