18,203 research outputs found
Framing effectiveness in impact assessment: Discourse accommodation in controversial infrastructure development
There is ongoing debate about the effectiveness of impact assessment tools, which matters both because of the threat to future practice of the tools which are frequently perceived to be ineffective, and because of the disillusionment that can ensue, and controversy generated, amongst stakeholders in a decision context where opportunities for meaningful debate have not been provided. In this article we regard debate about the meaning of effectiveness in impact assessment as an inevitable consequence of increased participation in environmental decision-making, and therefore frame effectiveness based on an inclusive democracy role to mean the extent to which impact assessment can accommodate civil society discourse. Our aim is to investigate effectiveness based on this framing by looking at one type of impact assessment - environmental impact assessment (EIA) - in two controversial project proposals: the HS2 rail network in England; and the A4DS motorway in the Netherlands. Documentary analysis and interviews held with key civil society stakeholders have been deployed to identify discourses that were mobilised in the cases. EIA was found to be able to accommodate only one out of four discourses that were identified; for the other three it did not provide the space for the arguments that characterised opposition. The conclusion in relation to debate on framings of effectiveness is that EIA will not be considered effective by the majority of stakeholders. EIA was established to support decision-making through a better understanding of impacts, so its ineffectiveness is unsurprising when its role is perceived to be broader. However, there remains a need to map discourses in different decision contexts and to analyse the extent to which the range of discourses are accommodated throughout the decision process, and the role of impact assessment in those processes, before recommendations can be made to either improve impact assessment effectiveness, or whether it is simply perceptions of effectiveness that need to be improved
Spray-on technique simplifies fabrication of complex thermal insulation blanket
Spray-on process constructs molds used in forming sections of thermal insulation blankets. The process simplifies the fabrication of blankets by eliminating much of the equipment formerly required and decreasing the time involved
Extent and duration of marine anoxia during the Frasnian– Famennian (Late Devonian) mass extinction in Poland, Germany, Austria and France
Abstract – The intensity and extent of anoxia during the two Kellwasser anoxic events has been
investigated in a range of European localities using amultidisciplinary approach (pyrite framboid assay,
gamma-ray spectrometry and sediment fabric analysis). The results reveal that the development of the
Lower Kellwasser Horizon in the early Late rhenana Zone (Frasnian Stage) in German type sections
does not always coincide with anoxic events elsewhere in Europe and, in some locations, seafloor
oxygenation improves during this interval. Thus, this anoxic event is not universally developed. In
contrast, the Upper Kellwasser Horizon, developed in the Late linguiformis Zone (Frasnian Stage) in
Germany correlates with a European-wide anoxic event that is manifest as an intensification of anoxia
in basinal locations to the point that stable euxinic conditionswere developed (for example, in the basins
of the Holy Cross Mountains, Poland). The interval also saw the spread of dysoxic waters into very
shallow water (for instance, reefal) locations, and it seems reasonable to link the contemporaneous
demise of many marine taxa to this phase of intense and widespread anoxia. In basinal locations,
euxinic conditions persisted into the earliest Famennian with little change of depositional conditions.
Only in the continental margin location of Austria was anoxia not developed at any time in the Late
Devonian. Consequently it appears that the Upper Kellwasser anoxic event was an epicontinental
seaway phenomenon, caused by the upward expansion of anoxia from deep basinal locales rather than
an ‘oceanic’ anoxic event that has spilled laterally into epicontinental settings
Insight into tube-building behaviour and palaeoecology of some agglutinating worms from the Upper Devonian of Nevada, USA
Agglutinated worm tubes from the Upper Devonian of the Devils Gate section in Nevada, USA are reported for the first time, filling a major gap in their Palaeozoic fossil record. Two small (5 mm and 6.7 mm in length) tubes are composed entirely of tentaculitid shells, and one large tube (55 mm in length) is formed from particles including ostracode carapaces, echinoderm ossicles, tentaculitid shells and putative bryozoan fragments aligned perpendicularly to the tube’s long axis. The tubes, in particular the large one have a cylindrical, curved and tapering tube morphology that is very similar to that of modern agglutinating polychaetes of the families Terebellidae and Pectinariidae. The large tube is dominated by objects that fall within a certain size-range, and although built from different types of particles, echinoderm ossicles are prevalent in the posterior part, whereas ostracode carapaces dominate in the middle and anterior parts of the tube. Tentaculitid shells are relatively rare in the large tube, despite being abundant in the surrounding host deposit. The faunal assemblage composing the tube suggests that the worm animal was rather specific in its selection of particles with a certain morphology. This is common behaviour amongst many modern agglutinating terebellid and pectinariid polychaetes. The preservation of such fragile tubes was enhanced by rapid burial, likely caused by gravity flow of sediment in a deep-slope setting
Large igneous provinces and mass extinctions: an update
The temporal link between mass extinctions and large igneous provinces is well known. Here, we examine this link by focusing on the potential climatic effects of large igneous province eruptions during several extinction crises that show the best correlation with mass volcanism: the Frasnian-Famennian (Late Devonian), Capitanian (Middle Permian), end-Permian, end-Triassic, and Toarcian (Early Jurassic) extinctions. It is clear that there is no direct correlation between total volume of lava and extinction magnitude because there is always sufficient recovery time between individual eruptions to negate any cumulative effect of successive flood basalt eruptions. Instead, the environmental and climatic damage must be attributed to single-pulse gas effusions. It is notable that the best-constrained examples of death-by-volcanism record the main extinction pulse at the onset of (often explosive) volcanism (e.g., the Capitanian, end-Permian, and end-Triassic examples), suggesting that the rapid injection of vast quantities of volcanic gas (CO 2 and SO 2 ) is the trigger for a truly major biotic catastrophe. Warming and marine anoxia feature in many extinction scenarios, indicating that the ability of a large igneous province to induce these proximal killers (from CO 2 emissions and thermogenic greenhouse gases) is the single most important factor governing its lethality. Intriguingly, many voluminous large igneous province eruptions, especially those of the Cretaceous oceanic plateaus, are not associated with significant extinction losses. This suggests that the link between the two phenomena may be controlled by a range of factors, including continental configuration, the latitude, volume, rate, and duration of eruption, its style and setting (continental vs. oceanic), the preexisting climate state, and the resilience of the extant biota to change
Signal-to-Noise Eigenmode Analysis of the Two-Year COBE Maps
To test a theory of cosmic microwave background fluctuations, it is natural
to expand an anisotropy map in an uncorrelated basis of linear combinations of
pixel amplitudes --- statistically-independent for both the noise and the
signal. These -eigenmodes are indispensible for rapid Bayesian analyses of
anisotropy experiments, applied here to the recently-released two-year COBE
{\it dmr} maps and the {\it firs} map. A 2-parameter model with an overall
band-power and a spectral tilt describes well inflation-based
theories. The band-powers for {\it all} the {\it dmr} + GHz
and {\it firs} 170 GHz maps agree, , and
are largely independent of tilt and degree of (sharp) -filtering. Further,
after optimal -filtering, the {\it dmr} maps reveal the same
tilt-independent large scale features and correlation function. The unfiltered
{\it dmr} + index is ; increasing the
-filtering gives a broad region at (1.0--1.2)0.5, a jump to
(1.4--1.6)0.5, then a drop to 0.8, the higher values clearly seen to be
driven by -power spectrum data points that do not fit single-tilt models.
These indices are nicely compatible with inflation values (0.8--1.2), but
not overwhelmingly so.Comment: submitted to Phys.Rev.Letters, 4 pages, uuencoded compressed
PostScript; also bdmr2.ps.Z, via anonymous ftp to ftp.cita.utoronto.ca, cd to
/pub/dick/yukawa; CITA-94-2
Knowledge development for organic systems: An example of weed management
Despite the large amount information on weed biology and specific weed control measures produced by researchers, organic farmers still prioritise weeds as an important area for further research. A recent project investigating weed management in organic farming systems has established that knowledge and learning are key requirements for this to be effective. Development of relevant, practically useful knowledge depends on access to information generated ‘scientifically’ by researchers and also to knowledge generated as a result of farmer experience with weeds. This requires that farmers, advisors and researchers take a participatory approach to collecting and processing information on weed management, using it to develop new and relevant knowledge. The appropriate framework for knowledge development is thus a collegiate one in which all stakeholders’ value and learn from the observations and experience of others. These findings have implications for the way in which research is conducted and funded
Geochemical and ecological aspects of lower Frasnian pyrite-ammonoid level at Kostomłoty (Holy Cross Mountains, Poland)
The lower Frasnian (transitans Zone with Ancyrodella priamosica = MN 4 Zone) rhythmic basin succession of marly limestones and
shales (upper Szydlówek Beds) at Kostomloty, western Holy CrossMts., Central Poland, contains a record of the transgressive-hypoxic
Timan Event in this drowned part of southern Laurussian shelf. The unique facies consists of organic-rich marly shales and a distinctive
pyritic, goniatite level, 1.6m thick. The faunal assemblage is dominated by pyritized shells of diminutivemollusks with cephalopods (including
goniatites Epitornoceras and Acanthoclymenia), buchioline bivalves (Glyptohallicardia) and styliolinids. This interval is
marked by moderately low Th/U ratios and pyrite framboid size distributions suggestive of dysoxic rather than permanent euxinic conditions.
The scarcity of infauna and bioturbation resulted in finely laminated sedimentary fabrics, as well as the low diversity of the presumed
pioneer benthos (mostly brachiopods). In the topmost part of the Szydlówek Beds, distinguished by the Styliolina coquina
interbedded between limestone-biodetrital layers, the above geochemical proxies and C-isotope positive shift indicate a tendency to
somewhat increased bottom oxygen deficiency and higher carbon burial rate linked with a bloom of pelagic biota during high-productivity
pulse. The geochemical and community changes are a complex regional record of the initial phase of a major perturbation in the
earth-ocean system during a phase of intermittently rising sea level in the early to middle Frasnian, and associated with the highest positive
C-isotope ratios of the Devonian
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