REMOTE SENSING OF FOLIAR NITROGEN IN CULTIVATED GRASSLANDS OF HUMAN DOMINATED LANDSCAPES

Foliar nitrogen (N) concentration of plant canopies plays a central role in a number of important ecosystem processes and continues to be an active subject in the field of remote sensing. Previous efforts to estimate foliar N at the landscape scale have primarily focused on intact forests and grasslands using aircraft imaging spectrometry and various techniques of statistical calibration and modeling. The present study was designed to extend this work by examining the potential to estimate the foliar N concentration of residential, agricultural and other cultivated grassland areas within a suburbanizing watershed. In conjunction with ground-based vegetation sampling, we developed Partial Least Squares (PLS) models for predicting mass-based foliar N across management types using input from airborne and field based imaging spectrometers. Results yielded strong predictive relationships for both ground- and aircraft-based sensors across sites that included turf grass, grazed pasture, hayfields and fallow fields. We also report on relationships between imaging spectrometer data and other important variables such as canopy height, biomass, and water content, results from which show strong promise for detection with high quality imaging spectrometry data and suggest that cultivated grassland offer opportunity for empirical study of canopy light dynamics. Finally, we discuss the potential for application of our results, and potential challenges, with data from the planned HyspIRI satellite, which will provide global coverage of data useful for vegetation N estimation

Phantom distribution functions for some stationary sequences

The notion of a phantom distribution function (phdf) was introduced by O'Brien (1987). We show that the existence of a phdf is a quite common phenomenon for stationary weakly dependent sequences. It is proved that any $\alpha$-mixing stationary sequence with continuous marginals admits a continuous phdf. Sufficient conditions are given for stationary sequences exhibiting weak dependence, what allows the use of attractive models beyond mixing. The case of discontinuous marginals is also discussed for $\alpha$-mixing. Special attention is paid to examples of processes which admit a continuous phantom distribution function while their extremal index is zero. We show that Asmussen (1998) and Roberts et al. (2006) provide natural examples of such processes. We also construct a non-ergodic stationary process of this type

Holography for inflation using conformal perturbation theory

We provide a precise and quantitative holographic description of a class of inflationary slow-roll models. The dual QFT is a deformation of a three-dimensional CFT by a nearly marginal operator, which, in the models we consider, generates an RG flow to a nearby IR fixed point. These models describe hilltop inflation, where the inflaton rolls from a local maximum of the potential in the infinite past (corresponding to the IR fixed point of the dual QFT) to reach a nearby local minimum in the infinite future (corresponding to the UV of the dual QFT). Through purely holographic means, we compute the spectra and bispectra of scalar and tensor cosmological perturbations. The QFT correlators to which these observables map holographically may be calculated using conformal perturbation theory, even when the dual QFT is strongly coupled. Both the spectra and the bispectra may be expressed this way in terms of CFT correlators that are fixed, up to a few constants, by conformal invariance. The form of slow-roll inflationary correlators is thus determined by the perturbative breaking of the de Sitter isometries away from the fixed point. Setting the constants to their values obtained by AdS/CFT at the fixed point, we find exact agreement with known expressions for the slow-roll power spectra and non-Gaussianities.Comment: 44 pp, 3 fig

The disability football player pathway: aiming to improve participation rates at the University of Lincoln

The Lincolnshire FA aims to support players with disabilities play football either as a part of a structured club, a team that plays in the school games, within the Lincolnshire Ability Counts League or more recreationally learning how to play. However, despite the FA’s best efforts and their disability football strategy 2010-2012, only 141,000 disabled players are involved in the game, from a total population of 11 million disabled people in the UK. (The Football Association, 2012, p.12). Indeed, although football is arguably the most popular sport in the country, the participation rates with Lincoln are relatively low. This project presents data from a programme evaluation (Rossi et al 2004, Evaluation: A systematic approach) of a project delivered in partnership with the Lincolnshire county F.A which aimed to investigate the barriers which prevent students which are partially sighted, blind, or those that suffer cerebral palsy, from participating in football. Furthermore, the study aimed to evaluate the impact of football taster sessions designed to increase participation among disabled children through the use of the ‘Mars play’ scheme. This scheme provides qualified coaches, who set up a football session for an hour, with no commitments for the players. However, the intention is that, if players were talented enough, they could be directed into of the disability player pathway in local player development centres. The primary aim of this research was to complete a programme evaluation of the scheme in order to investigate whether it met disabled students’ expectations of disability football during the ‘Mars Play’ scheme at the University of Lincoln. Participants completed questionnaires which aimed to discover why participants’ perceived barriers to participation in disability football, what is preventing them from playing, whether they were aware of how they can begin to participate and is whether they perceived disability football to be an appropriate activity for them. Once the results from the questionnaires had been analysed, interviews were completed with participants in the scheme in order to assess their perceptions of disability football, and to examine whether their perceived barriers had been addressed by our actions. With regards to the programme evaluation, the data will take both quantitative and qualitative forms with the intention of discovering whether or not the project met the intended aims. The implications of study findings were discussed in relation to the FA’s strategy for inclusion in disability football