Investigating the response of subtropical forests to environmental variation through the study of the Abies kawakamii treelines in Taiwan

Altitudinal treeline advance represents a sensitive and well-studied example of species response to climate warming. Although a great deal of work has been conducted globally, few studies have considered subtropical alpine treelines and little is known about their structure and function. This research aims to investigate the response of high altitude forests in Taiwan to climate variation by characterising treeline advance in the area, exploring the mechanisms driving the advance, and considering the consequences of advance for the wider community. The thesis consists of a general introduction to the topic followed by a series of papers, exploring: (1) Possible consequences of treeline shifts for biodiversity and ecosystem function. (2) The advance of the Abies kawakamii treeline through aerial photograph analysis. (3) The changes in growth rate of Abies kawakamii at treeline and the influence of altitude and temperature on growth. (4) Regeneration patterns at treeline and the importance of microclimate and topographic sheltering. (5) Consequences of the range shift for the wider forest community. The work is then concluded with a general discussion and synthesis. The main aims of this work are therefore to characterise and understand the pattern and pace of treeline advance and forest structural change throughout the Central Mountain Range of Taiwan. Treeline advance is characterised through the study of repeat aerial photographs and the mechanisms behind the observed shift are explored through the study of two key responses associated with forest advance: tree growth at treeline and seedling establishment beyond treeline. The consequences of treeline advance for the wider subalpine community are investigated through the study of epiphytic lichen communities at treeline sites. This investigation of an understudied region will allow for improved understanding of treeline response at a global scale

Metaphysics & Morals in Canadian Criminal Justice: A Pragmatic Analysis of The Conflict Between Neuroscience and Retributive Folk Psychology

The retributive justification of Canadian criminal law contains several assumptions about human nature that conflicts with what neuroscience has established regarding human behavior and the function of rationality. Interdisciplinary discourse on this conflict between law and neuroscience has unnecessarily implicated the free will debate and is further stagnated by epistemic cultural differences between the two disciplines. To avoid these roadblocks, this thesis applies the methodological principles of pragmatic philosophy. Rather than asking which description of human nature is true, pragmatic inquiry focuses on the difference either would make in practice. This analysis reveals that retributive folk psychology in practice causes various negative effects. In contrast, neuroscience offers practical insight into human behaviour that enables us to understand longstanding problems in the Canadian criminal justice system. Furthermore, coupled with compatible norms derived from alternative legal theory, it can support the development of progressive reforms in criminal justice

Ethnicity and the Mental Health Act 1983

Background Black and minority ethnic (BME) patients are disproportionately detained under the Mental Health Act 1983. There has been no systematic exploration of differences within and between ethnic groups, nor of the explanations put forward for this excess. Aims To systematically review detention and ethnicity, with meta-analyses of detention rates for BME groups, and to explore the explanations offered for ethnic differences in detention rates. Method Literature search and meta-analysis. Explanations offered were categorised, supporting literature was accessed and the strength of the evidence evaluated. Results In all, 49 studies met inclusion criteria; of these, 19 were included in the meta-analyses. Compared with White patients, Black patients were 3.83 times, BME patients 3.35 times and Asian patients 2.06 times more likely to be detained. The most common explanations related to misdiagnosis and discrimination against BME patients, higher incidence of psychosis and differences in illness expression. Many explanations, including that of racism within mental health services, were not supported by clear evidence. Conclusions Although BME status predicts psychiatric detention in the UK, most explanations offered for the excess detention of BME patients are largely unsupported

Consequences of treeline shifts for the diversity and function of high altitude ecosystems

Treeline expansion is reported as a widespread response to rising temperatures, yet few studies have considered the impact of treeline advance on the diversity and function of high altitude systems. Evidence suggests that climate change is already having a negative impact on alpine diversity and is modifying functions such as carbon sequestration and nutrient cycling. Treeline advance is likely to further affect diversity and function, yet our understanding of the processes involved is limited. Here we review and synthesize literature that assesses the impact of treeline advance into treeless ecosystems. Using published literature, we explore to what extent treeline advance will lead to the displacement of alpine species and the fragmentation of alpine habitats. While large changes will be observed in the ecosystems above the current treeline as trees migrate, it is likely that these newly forested areas will deviate substantially from the established forests from which they have developed. Consequently, at the forest community level we investigate the potential for differential response speeds of typical forest plant species, and the potential for treeline advance to lead to community disassembly. Given that changes in species presence and abundance can alter the functional composition of plant communities, we explore the potential for shifts in tree distribution to lead to changes in carbon storage, nutrient cycling, and hydrological properties of ecosystems. Despite typically being intensively studied regions, the likely impact of forest expansion above the current mountain treeline has received relatively little attention and so we identify key knowledge gaps that should act as priorities for future research in mountain systems

Is UV laser ablation a suitable tool for geochemical analysis of organic rich source materials?

Abstract not available

Potential of short wavelength laser ablation of organic materials

Although the literature contains several articles on UV laser ablation of synthetic polymers [1] and human tissue for surgical applications, to our knowledge there is no published record on organic geochemical applications for UV laser pyrolysis–gas chromatography–mass spectrometry (LA-GC-MS). In this study we have demonstrated the use of a 213 nm UV laser beam for ablating kerogens and organic rich rocks to liberate and analyse hydrocarbon signatures and compared the results against IR laser pyrolysis and traditional Py-GC-MS. It is possible to equate laser wavelength to electron volts where 1064 nm (IR) = 1.2 eV and 213 nm (UV) = 5.8 eV. Most chemical bonds have an energy between 2-4 eV and C-C bonds are ~3.6 eV. Organic materials can absorb radiation from a UV laser and chemical bonds can be cleaved cleanly by complex photochemical pathways by a single photon [2]. Ablation occurs with almost no heating of the sample and hence the term laser ablation instead of pyrolysis. Visible or IR lasers have insufficient energy to break bonds with a single photon this results in the heating of sample by the absobtion of energy into the vibrational modes of the molecule which can then result in pyrolysis. A solvent-extracted kerogen consisting mainly of higher plant material (Brownie Butte, Montanna, ~ 70 Ma) was used for initial experiments. A number of other samples have also been analysed. Laser ablation work was performed off-line in a static helium cell followed by solvent extraction of the laser cell. Separate analysis of the same samples using a more traditional flash pyrolysis approach was performed with a CDS pyroprobe and IR laser pyrolysis [3] for comparative purposes. As can be seen in Fig 1 UV laser ablation is able to liberate relatively high molecular weight fragments with no alkenes or other pyrolysis artefacts detected. SEM images of ablation pits indicate there is no obvious thermal alteration of the sample. The results of the pyrolysis techniques (on-line and IR laser pyrolysis) are similar and display a number of artefacts related to the pyrolysis process. Laser ablation of a number of samples has also shown that the distributions of biomarkers are comparable with the solvent extracts. Product yields although not quantified appear to be much higher than traditional pyrolysis technique

SUB-Depth: Self-distillation and Uncertainty Boosting Self-supervised Monocular Depth Estimation

We propose SUB-Depth, a universal multi-task training framework for self-supervised monocular depth estimation (SDE). Depth models trained with SUB-Depth outperform the same models trained in a standard single-task SDE framework. By introducing an additional self-distillation task into a standard SDE training framework, SUB-Depth trains a depth network, not only to predict the depth map for an image reconstruction task, but also to distill knowledge from a trained teacher network with unlabelled data. To take advantage of this multi-task setting, we propose homoscedastic uncertainty formulations for each task to penalize areas likely to be affected by teacher network noise, or violate SDE assumptions. We present extensive evaluations on KITTI to demonstrate the improvements achieved by training a range of existing networks using the proposed framework, and we achieve state-of-the-art performance on this task. Additionally, SUB-Depth enables models to estimate uncertainty on depth output.Comment: bmvc versio

A palaeo-glaciological reconstruction of the last Irish Ice Sheet.

An inversion of the glacial geomorphological record provides an effective means to reconstruct former ice sheets at ice sheet-scale. The last Irish Ice Sheet has a long history of investigation, but its most basic properties are debated. Much previous research, based on an incremental development of knowledge through field observation of glacigenic landforms and deposits, has locally yielded high levels of detail but this detail is spatially fragmented across the former ice sheet bed. The evidence-base for ice sheet reconstruction is therefore patchy and incomplete, and its internal inconsistencies make an ice sheet reconstruction, via this approach, problematic. This thesis explores new opportunities for palaeo-glaciological reconstruction offered by remotely sensed data. Systematic glacial landform mapping has been conducted throughout Ireland from a variety of satellite imagery and digital elevation models, and yields new Glacial Maps for Ireland comprising >39,000 landforms. These landform maps are the building blocks for a palaeo-glaciological reconstruction of the ice sheet. Adopting a 'flowset' approach, the full population of landform data is summarised as discrete cartographic units - flowsets - and their spatial, temporal and glaciodynamic information is extracted. The flowset record, integrated with the wealth of evidence and dating constraints in the literature, stimulates a reconstruction describing seven broad stages of ice sheet history. These provide a framework for the evolution of the last Irish Ice Sheet. Key elements of the reconstruction confirm and extend an early advance from a British ice source, a maximum period likely dominated by large ice streams, fragmentation of the ice sheet into separate ice bodies during retreat, and final decay in western mountain groups. The pattern of ice sheet evolution is both asymmetric and asynchronous. A range of scales of ice sheet behaviour are observed, from first-order, fundamental changes in ice sheet geometry (centres of mass and ice flow structure) to more local-scale high-frequency fluctuations of ice flow patterns. This new model acts as a framework for continued investigation of the evolution of the Irish Ice Sheet, and the observed ice sheet behaviour demands further exploration of the sensitivities and role of ice sheets in the wider ice - climate system

Seabed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier

Ice shelves are critical features in the debate about West Antarctic ice sheet change and sea level rise, both because they limit ice discharge and because they are sensitive to change in the surrounding ocean. The Pine Island Glacier ice shelf has been thinning rapidly since at least the early 1990s, which has caused its trunk to accelerate and retreat. Although the ice shelf front has remained stable for the past six decades, past periods of ice shelf collapse have been inferred from relict seabed "corrugations" (corrugated ridges), preserved 340 km from the glacier in Pine Island Trough. Here we present high-resolution bathymetry gathered by an autonomous underwater vehicle operating beneath an Antarctic ice shelf, which provides evidence of long-term change in Pine Island Glacier. Corrugations and ploughmarks on a sub-ice shelf ridge that was a former grounding line closely resemble those observed offshore, interpreted previously as the result of iceberg grounding. The same interpretation here would indicate a significantly reduced ice shelf extent within the last 11 kyr, implying Holocene glacier retreat beyond present limits, or a past tidewater glacier regime different from today. The alternative, that corrugations were not formed in open water, would question ice shelf collapse events interpreted from the geological record, revealing detail of another bed-shaping process occurring at glacier margins. We assess hypotheses for corrugation formation and suggest periodic grounding of ice shelf keels during glacier unpinning as a viable origin. This interpretation requires neither loss of the ice shelf nor glacier retreat and is consistent with a "stable" grounding-line configuration throughout the Holocene