1,658 research outputs found
What do we need for robust and quantitative health impact assessment?
Health impact assessment (HIA) aims to make the health consequences of decisions explicit. Decision-makers need to know that the conclusions of HIA are robust. Quantified estimates of potential health impacts may be more influential but there are a number of concerns. First, not everything that can be quantified is important. Second, not everything that is being quantified at present should be, if this cannot be done robustly. Finally, not everything that is important can be quantified; rigorous qualitative HIA will still be needed for a thorough assessment. This paper presents the first published attempt to provide practical guidance on what is required to perform robust, quantitative HIA. Initial steps include profiling the affected populations, obtaining evidence from for postulated impacts, and determining how differences in subgoups' exposures and suscepibilities affect impacts. Using epidemiological evidence for HIA is different from carrying out a new study. Key steps in quantifying impacts are mapping the causal pathway, selecting appropriate outcome measures and selecting or developing a statistical model. Evidence from different sources is needed. For many health impacts, evidence of an effect may be scarce and estimates of the size and nature of the relationship may be inadequate. Assumptions and uncertainties must therefore be explicit. Modelled data can sometimes be tested against empirical data but sensitivity analyses are crucial. When scientific problems occur, discontinuing the study is not an option, as HIA is usually intended to inform real decisions. Both qualitative and quantitative elements of HIA must be performed robustly to be of value
Changes in the Northern Limit of Spruce at Dubawnt Lake, Northwest Territories
Larsen described the treeline west of Hudson Bay and particularly at Ennadi, Yathkyed and Dubawnt Lakes, as clumps of spruce, relict from a former more northerly distribution. ... Evidence collected by us in 1966 on the Dubawnt River system on the Mackenzie-Keewatin border, indicates that the spruce trees are re-establishing themselves and have moved northward and closer to Dubawnt Lake during the past one hundred years. ... Larsen's view that spruce has not re-establsihed itself during the last half century does not apply at Dubawnt Lake, but may be true at the Ennadai and Yathkyed Lake regions. ... The known changes in the treeline in the Dubawnt Lake area can be summarized as follows: the south arm of the Keewatin Glacier left the lake area possibly from 7.5 to 7.9 thousands of years before the present or as late as 5.5 thousand years ago. By 4 thousand years ago, a closed canopy forest extended half way up the east shore of Lake Dubawnt, leaving fossil podzols. Individual clumps and trees probably extended further north. A southern retraction of treeline followed, but a re-extension took place c. A.D. 1100 at the "little climatic optimum". A southern retraction again occurred and by 1770 Hearne recorded dead stumps 20 miles north of the treeline. Around 1870, satisfactory growth conditions existed within 2 miles of the south end of Dubawnt Lake and a minor northward extension took place. Re-establishment of spruce by means other than layering occurred by 1931. Less favourable growth conditions may have begun again in 1960
The total assessment profile, volume 2
Appendices are presented which include discussions of interest formulas, factors in regionalization, parametric modeling of discounted benefit-sacrifice streams, engineering economic calculations, and product innovation. For Volume 1, see
The total assessment profile, volume 1
A methodology is described for the evaluation of societal impacts associated with the implementation of a new technology. Theoretical foundations for the methodology, called the total assessment profile, are established from both the economic and social science perspectives. The procedure provides for accountability of nonquantifiable factors and measures through the use of a comparative value matrix by assessing the impacts of the technology on the value system of the society
Atypical chemokine receptor ACKR2 controls branching morphogenesis in the developing mammary gland
Macrophages are important regulators of branching morphogenesis during development and postnatally in the mammary gland. Regulation of macrophage dynamics during these processes can therefore have a profound impact on development. We demonstrate here that the developing mammary gland expresses high levels of inflammatory CC-chemokines, which are essential in vivo regulators of macrophage migration. We further demonstrate that the atypical chemokine receptor ACKR2, which scavenges inflammatory CC-chemokines, is differentially expressed during mammary gland development. We have previously shown that ACKR2 regulates macrophage dynamics during lymphatic vessel development. Here, we extend these observations to reveal a novel role for ACKR2 in regulating the postnatal development of the mammary gland. Specifically, we show that Ackr2−/− mice display precocious mammary gland development. This is associated with increased macrophage recruitment to the developing gland and increased density of the ductal epithelial network. These data demonstrate that ACKR2 is an important regulator of branching morphogenesis in diverse biological contexts and provide the first evidence of a role for chemokines and their receptors in postnatal development processes
Organic nitrogen in aerosols and precipitation at Barbados and Miami: Implications regarding sources, transport and deposition to the western subtropical North Atlantic
The deposition of anthropogenic nitrogen (N) species is believed to have a significant impact on the oligotrophic North Atlantic, but the magnitude of ecological effects remains uncertain because the deposition of water soluble organic N (WSON) is poorly quantified. Here we present measurements of water soluble inorganic N (WSIN) and WSON in aerosol and rain at two subtropical North Atlantic time series sites: Barbados and Miami. WSON total deposition rates ranged from 17.9 mmol m−2 yr−1 to 49.6 mmol m−2 yr−1, contributing on average only 6–14% of total N deposition, less than half the poorly constrained global average which is typically cited as 30%. On an event basis, biomass burning and dust events yielded the largest concentrations of WSON. However, biomass burning was relatively infrequent and highly variable in composition, and much of the organic N associated with dust appeared to be externally adsorbed from pollution sources. Conversely, in Miami pollution made relatively small contributions of WSON on an event basis, but impacts were relatively frequent, making pollution one of the largest sources of WSON during the year. The largest contributor to WSON was volatile basic organic N (VBON) species, which were present at concentrations 1–2 times higher than particulate WSON. Despite VBON inputs, samples associated with pollution-source trajectories yielded much more inorganic N than WSON. Consequently, we would expect that in the future as anthropogenic N emissions increase, inorganic nitrogen will remain the dominant form of N that is deposited to the western North Atlantic
Variable cavity volume tooling for high-performance resin infusion moulding
This article describes the research carried out by Warwick under the BAE Systems/EPSRC programme ‘Flapless Aerial Vehicles Integrated Interdisciplinary Research – FLAVIIR’. Warwick's aim in FLAVIIR was to develop low-cost innovative tooling technologies to enable the affordable manufacture of complex composite aerospace structures and to help realize the aim of the Grand Challenge of maintenance-free, low-cost unmanned aerial vehicle manufacture. This article focuses on the evaluation of a novel tooling process (variable cavity tooling) to enable the complete infusion of resin throughout non-crimp fabric within a mould cavity under low (0.1 MPa) injection pressure. The contribution of the primary processing parameters to the mechanical properties of a carbon composite component (bulk-head lug section), and the interactions between parameters, was determined. The initial mould gap (di) was identified as having the most significant effect on all measured mechanical properties, but complex interactions between di, n (number of fabric layers), and vc (mould closure rate) were observed. The process capability was low due to the manual processing, but was improved through process optimization, and delivered properties comparable to high-pressure resin transfer moulding
Ambient air pollution exposure and chronic bronchitis in the Lifelines cohort
BACKGROUND: Few large studies have assessed the relationship of long-term ambient air pollution exposure with the prevalence and incidence of symptoms of chronic bronchitis and cough. METHODS: We leveraged Lifelines cohort data on 132 595 (baseline) and 65 009 (second assessment) participants linked to ambient air pollution estimates. Logistic regression models adjusted for sex, age, educational attainment, body mass index, smoking status, pack-years smoking and environmental tobacco smoke at home were used to assess associations of air pollution with prevalence and incidence of chronic bronchitis (winter cough and sputum almost daily for >/=3 months/year), chronic cough (winter cough almost daily for >/=3 months/year) and prevalence of cough and sputum symptoms, irrespective of duration. RESULTS: Associations were seen for all pollutants for prevalent cough or sputum symptoms. However, for prevalent and incident chronic bronchitis, statistically significant associations were seen for nitrogen dioxide (NO2) and black carbon (BC) but not for fine particulate matter (PM2.5). For prevalent chronic bronchitis, associations with NO2 showed OR: 1.05 (95% CI: 1.02 to 1.08) and with BC OR: 1.06 (95% CI: 1.03 to 1.09) expressed per IQR; corresponding results for incident chronic bronchitis were NO2 OR: 1.07 (95% CI: 1.02 to 1.13) and BC OR: 1.07 (95% CI: 1.02 to 1.13). In subgroup analyses, slightly stronger associations were observed among women, never smokers and younger individuals. CONCLUSION: This is the largest analysis to date to examine cross-sectional and longitudinal associations between ambient air pollution and chronic bronchitis. NO2 and BC air pollution was associated with increased odds of prevalent and incident chronic bronchitis
Assessing the apparent imbalance between geochemical and biochemical indicators of meso- and bathypelagic biological activity: What the @$#! is wrong with present calculations of carbon budgets?
Metabolic activity in the water column below the euphotic zone is ultimately fuelled by the vertical flux of organic material from the surface. Over time, the deep ocean is presumably at steady state, with sources and sinks balanced. But recently compiled global budgets and intensive local field studies suggest that estimates of metabolic activity in the dark ocean exceed the influx of organic substrates. This imbalance indicates either the existence of unaccounted sources of organic carbon or that metabolic activity in the dark ocean is being over-estimated. Budgets of organic carbon flux and metabolic activity in the dark ocean have uncertainties associated with environmental variability, measurement capabilities, conversion parameters, and processes that are not well sampled. We present these issues and quantify associated uncertainties where possible, using a Monte Carlo analysis of a published data set to determine the probability that the imbalance can be explained purely by uncertainties in measurements and conversion factors. A sensitivity analysis demonstrates that the bacterial growth efficiencies and assumed cell carbon contents have the greatest effects on the magnitude of the carbon imbalance. Two poorly quantified sources, lateral advection of particles and a population of slowly settling particles, are discussed as providing a means of closing regional carbon budgets. Finally, we make recommendations concerning future research directions to reduce important uncertainties and allow a better determination of the magnitude and causes of the unbalanced carbon budgets. (C) 2010 Elsevier Ltd. All rights reserved
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