Spatial Patterns of Tree Invasion in an Old Field: Implications for Restoration

In north-eastern North America, abandoned agricultural fields typically revert to forest after many decades of spontaneous succession. This process can be influenced in part by nearby available propagule sources and their natural patterns of dispersal. Ecological restoration encompasses understanding this natural process and how it may influence active or passive restoration efforts. This study attempts to determine the spatial and temporal patterns of establishing trees arising in an old field at 10 years post-cultivation and the implications of this process on restoration at rare and other similar sites. The 0.8 ha field is situated at rare, an ecological reserve in Cambridge, Ontario and is bordered by forest or hedgerow on all sides. Using Environmental Monitoring and Assessment Network (EMAN) protocols, vegetation sampling was completed in the field and adjacent forest and hedgerow. A complete tree inventory was undertaken in the field, followed by a sampling of potential seed sources in the forest and hedgerow. ESRI ArcMap, a Geographic Information System (GIS) was utilized for both spatial representation and spatial analysis. Research revealed that the application of geostatistics to ecological data here and elsewhere in the literature has some specific challenges which need to be overcome for analysis of spatial data. Currently, the old field shows early signs of woody plant invasion from the nearby forest. Both trees and shrubs have become established, though not yet dominant. The primary dispersal of these species follows spatial patterns based on method of dispersal (wind, nut, fruit and clonal) and there is a higher degree of clustering of all species closer to the forest edge. Invasive species such as Rhamnus cathartica and Rhamnus frangula have become established in the old field and may influence successional patterns. Implications for restoration include the creation of goals and objectives which incorporate these natural processes into a future management plan. Specific recommendations include: 1) Develop a management strategy for invasive species such as Rhamnus spp. which can detrimentally affect restoration goals; 2) Continue to monitor EMAN plots for the production of time-series data on the same site; 3) Identify sites with good regeneration potential based on spatial patterns identified in this research and collect additional information such as soil conditions, canopy cover, etc.; 4) Extend the current GIS database created for this thesis to become an inventory of natural and cultural features for the reserve. Advanced spatial analysis required a more extensive data set and/or custom programming

Laboratory EXAFS in a dispersive mode

A laboratory dispersive mode spectrometer, capable of operating in either the analysing crystal transmission mode or a reflection mode, is described. Extended X-ray absorption fine structure (EXAFS) spectra of Re and ReO2, obtained in the transmission mode, compare favourably with those from a scanning spectrometer at a synchrotron source. Factors affecting resolution, intensity and background in this transmission mode are discussed. Experiments with asymmetric reflection geometries, which have shown both improved resolution for X-ray absorption near edge structure (XANES) and reduced collection times, are reported. Methods of reducing backgrounds due to multiple Bragg reflections and Compton scattering are proposed

Information and communication technology solutions for outdoor navigation in dementia

INTRODUCTION: Information and communication technology (ICT) is potentially mature enough to empower outdoor and social activities in dementia. However, actual ICT-based devices have limited functionality and impact, mainly limited to safety. What is an ideal operational framework to enhance this field to support outdoor and social activities? METHODS: Review of literature and cross-disciplinary expert discussion. RESULTS: A situation-aware ICT requires a flexible fine-tuning by stakeholders of system usability and complexity of function, and of user safety and autonomy. It should operate by artificial intelligence/machine learning and should reflect harmonized stakeholder values, social context, and user residual cognitive functions. ICT services should be proposed at the prodromal stage of dementia and should be carefully validated within the life space of users in terms of quality of life, social activities, and costs. DISCUSSION: The operational framework has the potential to produce ICT and services with high clinical impact but requires substantial investment

Electron-Phonon Interaction in Tetrahedral Semiconductors

Effects of electron-phonon interactions on the band structure can be experimentally investigated in detail by measuring the temperature dependence of energy gaps or critical points (van Hove singularities) of the optical excitation spectra. These studies have been complemented in recent years by observing the dependence of such spectra on isotopic mass whenever different stable isotopes of a given atom are available at affordable prices. In crystals composed of different atoms, the effect of the vibration of each separate atom can thus be investigated by isotopic substitution. Because of the zero-point vibrations, such effects are present even at zero temperature (T = 0). In this paper we discuss state-of-the-art calculations of the dielectric function spectra and compare them with experimental results, with emphasis on the differences introduced by the electron-phonon interaction. The temperature dependence of various optical parameters will be described by means of one or two (in a few cases three) Einstein oscillators, except at the lowest temperatures where the T4 law (contrary to the Varshini T2 result) will be shown to apply. Increasing an isotopic mass increases the energy gaps, except in the case of monovalent Cu (e.g., CuCl) and possibly Ag (e.g., AgGaS2). It will be shown that the gaps of tetrahedral materials containing an element of the first row of the periodic table (C,N,O) are strongly affected by the electron-phonon interaction. It will be conjectured that this effect is related to the superconductivity recently observed in heavily boron-doped carbon.Comment: 17 pages, 17 fifure

A complex multimodal activity intervention to reduce the risk of dementia in mild cognitive impairment - ThinkingFit: : pilot and feasibility study for a randomized controlled trial

© 2014 Dannhauser et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The version of record, Thomas M. Dannhauser, Martin Cleverly, Tim J. Whitfield, Ben (C) Fletcher, and Tim Stevens, 'A complex multimodal activity intervention to reduce the risk of dementia in mild cognitive impairment - ThinkingFit: pilot and feasibility study for a randomized controlled trial', BMC Psychiatry, 2014, 14: 129, is available online via doi: 10.1186/1471-244X-14-129Dementia affects 35 million people worldwide and is currently incurable. Many cases may be preventable because regular participation in physical, mental and social leisure activities during middle age is associated with up to 47% dementia risk reduction. However, the majority of middle-aged adults are not active enough. MCI is therefore a clear target for activity interventions aimed at reducing dementia risk. An active lifestyle during middle age reduces dementia risk but it remains to be determined if increased activity reduces dementia risk when MCI is already evident. Before this can be investigated conclusively, complex multimodal activity programmes are required that (1) combine multiple health promoting activities, (2) engage people with MCI, and (3) result in sufficient adherence ratesPeer reviewedFinal Published versio

Doctoral dissertation management at the University of Granada

La Universidad de Granada (UGR) cuenta desde 2005 con el Proyecto DIGIBUG, un modelo que mejora la visibilidad y accesibilidad de su producción científica, con el objetivo de acercarla a los investigadores, doctorandos, estudiantes y a la sociedad en general, ofreciendo una nueva perspectiva de difusión, utilización, citación y seguimiento de las diferentes líneas de investigación existentes en la UGR.Since 2005 the University of Granada (UGR) has implemented the DIGIBUG Project, which aims to improve visibility of and access to its scientific output so as to bring it closer to researchers, doctorate and undergraduate students and society in general, providing a new way of disseminating, using, citing and following up the different lines of enquiry at the UGR