297 research outputs found
Regionalisation and the rescaling of agro-food governance: case study evidence from two English regions
Copyright © 2012 Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Political Geography, 2012, Vol. 31 Issue 2, pp. 83 – 93 DOI: 10.1016/j.polgeo.2011.10.007Some researchers detected a new-found subsidiarity in rural policy after England’s 2001 Foot and Mouth Disease epidemic, with regional and sub-regional institutions working together to implement an economic recovery strategy. While such research began to link debates on the new regionalism and the re-scaling of agro-food governance, its conception of the latter focused too narrowly on the ‘turn to quality’, thereby overlooking other important aspects of food relocalisation. Based on interviews conducted in England’s South West and West Midlands regions, this paper examines whether the attitudes of key actors from regional and sub-regional governance institutions provided a sound basis for partnership working on the food relocalisation policies recommended in the Government’s Strategy for Sustainable Farming and Food. It finds different attitudes on the part of regional and sub-regional actors, with the former favouring regional foods and the latter local foods. Despite scepticism from both groups about the ability of the England Rural Development Programme (2000-2006) to promote food relocalisation, grants were awarded to both regional and local food entrepreneurs, suggesting that the programme contributed more to food relocalisation than previously thought
Changes in trabecular bone, hematopoiesis and bone marrow vessels in aplastic anemia, primary osteoporosis, and old age
Retrospective histologic analyses of bone biopsies and of post mortem samples from normal persons of different age groups, and of bone biopsies of age- and sex-matched groups of patients with primary osteoporosis and aplastic anemia show characteristic age dependent as well as pathologic changes including atrophy of osseous trabeculae and of hematopoiesis, and changes in the sinusoidal and arterial capillary compartments. These results indicate the possible role of a microvascular defect in the pathogenesis of osteoporosis and aplastic anemia
Eruptive shearing of tube pumice: pure and simple
Abstract. Understanding the physico-chemical conditions extant and mechanisms operative during explosive volcanism is essential for reliable forecasting and mitigation of volcanic events. Rhyolitic pumices reflect highly vesiculated magma whose bubbles can serve as a strain indicator for inferring the state of stress operative immediately prior to eruptive fragmentation. Obtaining the full kinematic picture reflected in bubble population geometry has been extremely difficult, involving dissection of a small number of delicate samples. The advent of reliable high-resolution tomography has changed this situation radically. Here we demonstrate via the use of tomography how a statistically powerful picture of the shapes and connectivity of thousands of individual bubbles within a single sample of tube pumice emerges. The strain record of tube pumice is dominated by simple shear (not pure shear) in the late deformational history of vesicular magma before eruption. This constraint in turn implies that magma ascent is conditioned by a velocity gradient at the point of origin of tube pumice. Magma ascent accompanied by simple shear should enhance high eruption rates inferred independently for these highly viscous systems. </jats:p
Seismicity and dynamics of the Upper Rhinegraben
In this paper we present the results of a 10-year period (1971-1980) of research on the seismicity of the Upper Rhinegraben. Our investigations are exclusively based on instrumentally recorded earthquakes with local magnitudes between 0.5 < ML < 5. The increase in the number of high-gain seismic stations during the past 2 decades improved the quality of the observations considerably, thus allowing detailed recognition of the spatial distribution of the earthquake loci in focal areas deduced from the analysis of historical events. No region, regarded up to now as aseismic, revealed itself as seismic, not even at the level of microearthquakes. Excluding the focal area of the Swabian Jura, the northernmost and southernmost parts of the Upper Rhinegraben show the highest degree of seismic activity. The middle part of the Rhinegraben, between Strasbourg and Karlsruhe, reveals only modest activity, somewhat in contrast to the historical record. The number of earthquakes increases towards the east of the river Rhine relative to the west. An even more pronounced asymmetry is shown in the southern graben by different maximum focal depths perpendicular to the strike of the Rhinegraben. In the Vosges mountains and in the graben proper, depths of 13 and 16 km, respectively, are not exceeded. Maximum depths down to about 20 km are found in the Black Forest. No earthquake was detected in the lower gabbroic crust or in the mantle. The maximum focal depth seems to be governed by variations in the temperature-depth distribution. Fault plane solutions of more than 30 earthquakes demonstrate that the seismic dislocations take place predominantly as strike slip mechanisms in the southern graben area whereas normal faulting prevails in the north. In the northern graben, most of the seismic dislocations occur on fault segments striking N30°W whereas in the south a strike ofN20°E or N60°W (the conjugate direction) is dominant. Furthermore, the fault plane solutions indicate a clockwise rotation of the principle stress directions from north to south by about 40°.
ARK: https://n2t.net/ark:/88439/y060010
Permalink: https://geophysicsjournal.com/article/81
 
Public opinion on energy crops in the landscape: considerations for the expansion of renewable energy from biomass
Public attitudes were assessed towards two dedicated biomass crops – Miscanthus and Short Rotation Coppice (SRC), particularly regarding their visual impacts in the landscape. Results are based on responses to photographic and computer-generated images as the crops are still relatively scarce in the landscape. A questionnaire survey indicated little public concern about potential landscape aesthetics but more concern about attendant built infrastructure. Focus group meetings and interviews indicated support for biomass end uses that bring direct benefits to local communities. Questions arise as to how well the imagery used was able to portray the true nature of these tall, dense, perennial plants but based on the responses obtained and given the caveat that there was limited personal experience of the crops, it appears unlikely that wide-scale planting of biomass crops will give rise to substantial public concern in relation to their visual impact in the landscape
Valoriser et conserver le pin de Salzmann en France -
Cet article fait le point sur l'état des connaissances disponibles sur le pin de Salzmann, dans les domaines écologique, sylvicole et de diversité génétique. Il fait aussi état des risques qui menacent cette ressource française originale, caractéristique de la forêt méditerranéenne et indique quelles sont les stratégies actuelles employées pour sauvegarder et utiliser durablement les populations naturelles
Recommended from our members
How predation and landscape fragmentation affect vole population dynamics
Background: Microtine species in Fennoscandia display a distinct north-south gradient from regular cycles to stable
populations. The gradient has often been attributed to changes in the interactions between microtines and their predators.
Although the spatial structure of the environment is known to influence predator-prey dynamics of a wide range of species,
it has scarcely been considered in relation to the Fennoscandian gradient. Furthermore, the length of microtine breeding
season also displays a north-south gradient. However, little consideration has been given to its role in shaping or generating
population cycles. Because these factors covary along the gradient it is difficult to distinguish their effects experimentally in
the field. The distinction is here attempted using realistic agent-based modelling.
Methodology/Principal Findings: By using a spatially explicit computer simulation model based on behavioural and
ecological data from the field vole (Microtus agrestis), we generated a number of repeated time series of vole densities
whose mean population size and amplitude were measured. Subsequently, these time series were subjected to statistical
autoregressive modelling, to investigate the effects on vole population dynamics of making predators more specialised, of
altering the breeding season, and increasing the level of habitat fragmentation. We found that fragmentation as well as the
presence of specialist predators are necessary for the occurrence of population cycles. Habitat fragmentation and predator
assembly jointly determined cycle length and amplitude. Length of vole breeding season had little impact on the
oscillations.
Significance: There is good agreement between our results and the experimental work from Fennoscandia, but our results
allow distinction of causation that is hard to unravel in field experiments. We hope our results will help understand the
reasons for cycle gradients observed in other areas. Our results clearly demonstrate the importance of landscape
fragmentation for population cycling and we recommend that the degree of fragmentation be more fully considered in
future analyses of vole dynamics
- …