A quiet revolution? Beneath the surface of Ireland's alternative food initiatives

Getting food to our plates has become a highly complex, industrialised and globalised process. However, transformations in how our food is supplied are not without resistance. Initiatives are emerging that take a step back to simpler, alternative methods of food supply, bringing the producer and consumer closer together. Alternative food initiatives which are commonly found in Ireland include allotments, community gardens, farmers' markets, farm shops and on-farm food enterprises. Understanding alternative food activities as a social movement can illuminate a fresh perspective on their nature and potential. While briefly considering the broad dynamics of alternative food activity in Ireland, this exploratory paper looks at the question of the nature of resistance and whether a collective vision may exist across initiatives, illustrated by two examples, a community garden and consumer food co-op. Finally some conclusions as to how alternative food initiatives may play a transformative role within the contemporary food system are discussed.     

Reconstructing the 3-D Trajectories of CMEs in the Inner Heliosphere

A method for the full three-dimensional (3-D) reconstruction of the trajectories of coronal mass ejections (CMEs) using Solar TErrestrial RElations Observatory (STEREO) data is presented. Four CMEs that were simultaneously observed by the inner and outer coronagraphs (COR1 and 2) of the Ahead and Behind STEREO satellites were analysed. These observations were used to derive CME trajectories in 3-D out to ～?15?R _⊙. The reconstructions using COR1/2 data support a radial propagation model. Assuming pseudo-radial propagation at large distances from the Sun (15?–?240?R _⊙), the CME positions were extrapolated into the Heliospheric Imager (HI) field-of-view. We estimated the CME velocities in the different fields-of-view. It was found that CMEs slower than the solar wind were accelerated, while CMEs faster than the solar wind were decelerated, with both tending to the solar wind velocity.     

Analysis of flow processes in fractured chalk under pumped and ambient conditions (UK)

An integrated set of different measurements has been used to study the behavior of groundwater in an observation well in a fractured rock formation, the UK Chalk, under pumped and ambient conditions. Under pumped conditions, the response of the open borehole was relatively straightforward with flow mainly concentrated along four discrete flow horizons. Furthermore, excellent correspondence was observed between the three methods of borehole flow velocity measurement: impeller flowmeter, heat-pulse flowmeter and dilution testing. Under ambient conditions, the system appeared more complicated. Specifically, in the upper half of the borehole, the impeller flowmeter exhibited substantial downward flow and the heat-pulse flowmeter exhibited almost negligible upward flow, whilst dilution testing indicated significant dilution. It was concluded that this was due to cross-flow occurring over the upper 29 m. Analysis of drawdown data, recovery data and a Drost analysis of the ambient cross-flow data yielded aquifer transmissivity estimates of 2,049, 2,928 and > 4,388 m²/day respectively. The discrepancy between the drawdown and recovery estimates was attributed to non-linear head-losses associated with turbulence and inertial effects. The difference between the pumping test and Drost results was explained by the flow during the pumping test bypassing this aforementioned 29 m region of rock.     

Recent chronologies for tree rings and terrestrial archives using C bomb fallout history

Tree rings representing the period from the mid-1950s up to 2001 were studied as part of an investigation of anthropogenic radionuclide input to terrestrial systems. A live specimen of Pinus sylvestris from the east coast of Ireland was felled, sampled and analysed for comparison with a similar tree felled close to the Atlantic seaboard on the west coast of Ireland. Data for the tree ring sequences were examined relative to the radionuclide content of peat profiles sampled in close proximity to the locations of the studied Pine trees.The data indicate that ¹⁴C concentrations in tree ring sequences from the east and west coasts of Ireland are virtually identical. The sequences show maximum ¹⁴C concentrations (185 and 189 pMC at east and west coast sites, respectively) that correspond closely with published data for atmospheric levels during the height of the nuclear weapons test period (1945-1980). The tree ring count for the specimen from the east coast places the ¹⁴C peak precisely at 1964, the year following the known peak in atmospheric concentrations due to above ground testing of nuclear weapons. However, ¹⁴C data show that simple ring counting of the west coast tree did not provide an accurate chronology. The data demonstrate the importance of applying dendrodating techniques using replicated site chronologies, and the value of the ¹⁴C bomb fallout curve for the construction of recent chronologies. Data show no evidence of enhanced uptake at the east coast that might suggest incorporation of output from the Sellafield nuclear complex or from the release of radioactivity resulting from an accidental fire at the plant in 1957.     

Bayesian Mixture Modelling in Geochronology via Markov Chain Monte Carlo

In this paper we develop a generalized statistical methodology for characterizing geochronological data, represented by a distribution of single mineral ages. The main characteristics of such data are the heterogeneity and error associated with its collection. The former property means that mixture models are often appropriate for their analysis, in order to identify discrete age components in the overall distribution. We demonstrate that current methods (e.g., Sambridge and Compston, 1994) for analyzing such problems are not always suitable due to the restriction of the class of component densities that may be fitted to the data. This is of importance, when modelling geochronological data, as it is often the case that skewed and heavy tailed distributions will fit the data well. We concentrate on developing (Bayesian) mixture models with flexibility in the class of component densities, using Markov chain Monte Carlo (MCMC) methods to fit the models. Our method allows us to use any component density to fit the data, as well as returning a probability distribution for the number of components. Furthermore, rather than dealing with the observed ages, as in previous approaches, we make the inferences of components from the “true” ages, i.e., the ages had we been able to observe them without measurement error. We demonstrate our approach on two data sets: uranium-lead (U-Pb) zircon ages from the Khorat basin of northern Thailand and the Carrickalinga Head formation of southern Australia.     

Rhizome growth dynamics of native and exotic haplotypes ofPhragmites australis (Common reed)

Phragmites australis (common reed), a clonal grass, has expanded from a minor component of the mid-Atlantic wetlands to a dominant species. It has been suggested that invasive populations ofPhragmites are an exotic haplotype responsible for the dramatic increase in the distribution of the species. We used field observations and measurements and a greenhouse assay to compare native (haplotype F) and exotic (haplotype M) populations, growing adjacent to one another in a brackish marsh near Odessa, Delaware. In the marsh, shoots of the exotic strain emerged from the rhizomes earlier than those of the native and by March there was an order of magnitude more new shoots of the exotic strain than the native. In August, the exotic strain was 30% taller than the native, had twice the leaf biomass, and twice the total biomass. Nine of ten morphological and biomass characteristics measured differed significantly between the native and exotic strains. A greenhouse assay was conducted by planting rhizomes collected in March in shallow trays and growing them for 70 d followed by shoot harvest (Harvest 1). Rhizomes were measured, replanted, and grown for 35 d after which time they were measured and shoots were harvested (Harvest 2). At Harvest 1, shoot height was approximately 80% greater in the exotic strain, shoot biomass was three times higher, aboveground to belowground biomass ratio was twice as high, and rhizome internode length was 50% greater in the exotic strain than the native. These traits, in addition to number of shoots, were also greater in the exotic strain at Harvest 2. The number of rhizome buds at Harvest 1 was three times greater in the native than in the exotic strain. The greater number of rhizome buds in the native would seem to be an advantage, but it did not result in more shoot production. Buds were maintained in an inactive state that does not allow this strain to compete well in a wetland environment inhabited by a more efficient spreader. The earlier emergence of new shoots from the rhizomes, the greater aboveground structure, the greater rhizome internode length, and the quick transition of rhizome buds to shoot or rhizome explain in part the exotic strain's advantage over the native and the mechanisms for its invasive nature.