Replicability of data collected for empirical estimation of relative pollen productivity

The effects of repeated survey and fieldwork timing on data derived from a recently proposed standard field methodology for empirical estimation of relative pollen productivity (RPP) have been tested. Seasonal variations in vegetation and associated pollen assemblages were studied in three contrasting cultural habitat types; semi-natural ancient woodlands, lowland heaths, and unimproved, traditionally managed hay meadows. Results show that in woodlands and heathlands the standard method generates vegetation data with a reasonable degree of similarity throughout the field season, though in some instances additional recording of woodland canopy cover should be undertaken, and differences were greater for woodland understorey taxa than for arboreal taxa. Large differences in vegetation cover were observed over the field season in the grassland community, and matching the phenological timing of surveys within and between studies is clearly important if RPP estimates from these sites are to be comparable. Pollen assemblages from closely co-located moss polsters collected on different visits are shown to be variable in all communities, to a greater degree than can be explained by the sampling error associated with pollen counting, and further study of moss polsters as pollen traps is recommended

Critical Dynamics of Dimers: Implications for the Glass Transition

The Adam-Gibbs view of the glass transition relates the relaxation time to the configurational entropy, which goes continuously to zero at the so-called Kauzmann temperature. We examine this scenario in the context of a dimer model with an entropy vanishing phase transition, and stochastic loop dynamics. We propose a coarse-grained master equation for the order parameter dynamics which is used to compute the time-dependent autocorrelation function and the associated relaxation time. Using a combination of exact results, scaling arguments and numerical diagonalizations of the master equation, we find non-exponential relaxation and a Vogel-Fulcher divergence of the relaxation time in the vicinity of the phase transition. Since in the dimer model the entropy stays finite all the way to the phase transition point, and then jumps discontinuously to zero, we demonstrate a clear departure from the Adam-Gibbs scenario. Dimer coverings are the "inherent structures" of the canonical frustrated system, the triangular Ising antiferromagnet. Therefore, our results provide a new scenario for the glass transition in supercooled liquids in terms of inherent structure dynamics

American Cultural Values : A Look at One\u27s Own Cultural Identity

This paper is presented in two sections. Part A sets out a 16-lesson course for American ESL teachers in which people will look at personal and cultural values, with the goal of achieving an objective insight into the values of their culture and developing ways of incorporating this awareness in the ESL classroom. Should this course be used by non-American teachers there is another course outline (see Alternative Course Outline for Non-native Speakers of English) that has been developed. Part B is an articulation of some major values pertinent to American society. Areas covered are success, time, work, individualism, equality, world view and moral orientation

Seeing the wood for the trees:Recent advances in the reconstruction of woodland in archaeological landscapes using pollen data

Pollen sequences record the vegetation cover of past landscapes, but translating a pollen diagram into a landscape reconstruction is not straightforward. This paper reviews recent advances in the reconstruction of woodland cover from palynological data and shows how they have been used to address three archaeologically relevant problems: • The detection of woodland presence and extent in a largely open landscape • The reconstruction of the habitat context of a specific archaeological site • The detection of woodland management Pollen surface samples which can be directly related to contemporary vegetation cover are shown to be useful both in their own right and as the basis for calibration of models of pollen dispersal and deposition. These models can be used as a foundation for quantitative reconstruction of past landscapes, for example using the Multiple Scenario Approach, or as a tool for construction and testing of hypotheses and to inform selection of coring sites. We argue that surface sample studies and simulation approaches are improving the scientific basis of reconstruction of past landscapes, and that these approaches offer new opportunities for communication and collaboration between archaeologists and environmental specialists

Do local habitat conditions affect estimates of relative pollen productivity and source area in heathlands?

Relative Pollen Productivity is an essential parameter for quantitative reconstruction of past land cover from pollen records, but published studies have produced a range of different values for the same taxa. Heathland habitats have limited plant diversity and strong spatial patterning, therefore are useful case studies to investigate aspects of pollen dispersal and deposition, but the estimated spatial area “sensed” by pollen records in these habitats also varies widely between studies. In this study, we estimate pollen productivity from two different microhabitats in a heathland ecosystem in order to investigate the role of local environmental conditions in any observed differences.Vegetation survey was carried out using the Crackles Bequest Project method, pollen assemblages from moss samples counted using standard methods, and relative pollen productivity and estimated source area derived using Extended R-Value analysis. Analysis of the data suggests that at least two pollen source areas exist at the sites studied, reflecting scales of landscape organisation. Microhabitat does not appear to have a marked effect on estimates of Relative Pollen Productivity in this heathland system. This study confirms earlier findings that the estimates obtained for some taxafrom heathlands are substantially different than those from gricultural landscapes,especially Poaceae. The findings suggest that the factors controlling Relative Pollen Productivity are still not fully understood, and that differences between locations may reflect real, habitat-led differences. Further investigation of this parameter, whichis central to reconstruction of past land cover from pollen records whether overtly incorporated via an algebraic model or less explicitly present via ecological narrative, biomisation or modern analog approaches, is clearly necessary

Assessing the impact of deliberation and information on opinion change: a quasi-experiment in public deliberation

Deliberative democracy has become fashionable for many and it has been used in some places to solve real-world policy problems. However measuring the ‘success’ of deliberative democracy is not clearly achievable. For most ‘success’ is measured in terms of opinion change, but these are only rarely measured against control groups, and in particular there is no way of knowing if the opinion change took place because of the deliberation or because of information they received through the deliberation process. Exercises in deliberation seem to represent one big treatment. But we would want to separate out the component parts of the treatment. This paper outlines the results of an experiment in which deliberation took place in a pilot Citizens’ Assembly in Ireland. As part of this we measured the impact using pre and post-test controls, including a control group given the information the CA participants received, but without the deliberation. The results of the experiment reveal that there is a deliberation effect separate to the information effect