Towards A Short to Medium Term Mitigation Strategy to Address the External Air and Sea Connectivity Challenges posed by the COVID-19 Pandemic for Northern Ireland

The overall aim of the research is the preparation of a short to medium term Access Mitigation Strategy to respond to the challenges posed for the business, travel, leisure and tourism sectors by the physical and psychological impacts on travel access to/from Northern Ireland during/post the COVID-19 Pandemic. The research programme reflects the need to understand the implications of the COVID-19 crisis on accessibility to/from Northern Ireland given the region’s heavy reliance on air and sea access for trade, Foreign Direct Investment (FDI) and tourism. This includes the fall-out from COVID-19 (and additional factors including Flybe, Brexit) on the capacity of air and sea routes, how demand has and will be impacted in the future because of changing behaviours and what actions need to be taken to minimise these effects and keep Northern Ireland open for business. The project objectives are as follows: To establish the current position and near to medium term prospects for air and sea connectivity to Northern Ireland (including Irish Sea ports and airports); review the contribution of air and sea links to the performance of the Northern Ireland Economy and Wider Society; assess the factors shaping this position and their impact on demand for external travel before, during and post the Coronavirus Pandemic; develop a range of future scenarios around passenger transport by air and sea to inform the development of a range of mitigation policy interventions to maximise the accessibility of the region; table recommendations for a mitigation policy to maximise accessibility of the region; and assess the potential for funding and financing a Short to Medium Term Access Mitigation Strategy for the region. The research findings and its recommendations are informed by robust empirical evidence bases and include proven public policy interventions to maximise the region’s access and openness to business and tourism related travel going forward

Overexpression of Mcl-1 exacerbates lymphocyte accumulation and autoimmune kidney disease in lpr mice

Cell death by apoptosis has a critical role during embryonic development and in maintaining tissue homeostasis. In mammals, there are two converging apoptosis pathways: the ‘extrinsic’ pathway, which is triggered by engagement of cell surface ‘death receptors’ such as Fas/APO-1; and the ‘intrinsic’ pathway, which is triggered by diverse cellular stresses, and is regulated by prosurvival and pro-apoptotic members of the Bcl-2 family of proteins. Pro-survival Mcl-1, which can block activation of the proapoptotic proteins, Bax and Bak, appears critical for the survival and maintenance of multiple haemopoietic cell types. To investigate the impact on haemopoiesis of simultaneously inhibiting both apoptosis pathways, we introduced the vavP-Mcl-1 transgene, which causes overexpression of Mcl-1 protein in all haemopoietic lineages, into Faslpr/lpr mice, which lack functional Fas and are prone to autoimmunity. The combined mutations had a modest impact on myelopoiesis, primarily an increase in the macrophage/monocyte population in Mcl-1tg/lpr mice compared with lpr or Mcl-1tg mice. The impact on lymphopoiesis was striking, with a marked elevation in all major lymphoid subsets, including the non-conventional double-negative (DN) T cells (TCRβ+ CD4– CD8– B220+ ) characteristic of Faslpr/lpr mice. Of note, the onset of autoimmunity was markedly accelerated in Mcl-1tg/lpr mice compared with lpr mice, and this was preceded by an increase in immunoglobulin (Ig)-producing cells and circulating autoantibodies. This degree of impact was surprising, given the relatively mild phenotype conferred by the vavP-Mcl-1 transgene by itself: a two- to threefold elevation of peripheral B and T cells, no significant increase in the non-conventional DN T-cell population and no autoimmune disease. Comparison of the phenotype with that of other susceptible mice suggests that the development of autoimmune disease in Mcl-1tg/lpr mice may be influenced not only by Ig-producing cells but also other haemopoietic cell types

Theory and optimisation of 1.3 and 1.55 μm (Al)InGaAs metamorphic quantum well lasers

The use of InGaAs metamorphic buffer layers (MBLs) to facilitate the growth of lattice-mismatched heterostructures constitutes an attractive approach to developing long-wavelength semiconductor lasers on GaAs substrates, since they offer the improved carrier and optical confinement associated with GaAs-based materials. We present a theoretical study of GaAs-based 1.3 and 1.55 μm (Al)InGaAs quantum well (QW) lasers grown on InGaAs MBLs. We demonstrate that optimised 1.3 μm metamorphic devices offer low threshold current densities and high differential gain, which compare favourably with InP-based devices. Overall, our analysis highlights and quantifies the potential of metamorphic QWs for the development of GaAs-based long-wavelength semiconductor lasers, and also provides guidelines for the design of optimised devices

Brain Volume and Neuropsychological Differences in Extremely Preterm Adolescents

Although findings have revealed that preterm subjects are at higher risk of brain abnormalities and adverse cognitive outcome, very few studies have investigated the long-term effects of extreme prematurity on regional brain structures, especially in adolescence. The current study aims to investigate the volume of brain structures of 88 extremely preterm born 19-year old adolescents and 54 age- and socioeconomically-matched full-term born subjects. In addition, we examine the hypothesis that the volume of grey matter regions where a significant group or group-sex differences are found would be connected with the neurodevelopmental outcome. The results of the analysis show regional brain difference linked to extreme prematurity with reduced grey matter content in the subcortical regions and larger grey matter volumes distributed around the medial prefrontal cortex and anterior medial cortex. Premature birth and the volume of the left precuneus and the right posterior cingulate gyrus accounts for 34% of the variance in FSIQ. The outcome of this analysis reveals that structural brain differences persist into adolescence in extremely preterm subjects and that they correlate with cognitive functions

Neural Network Analysis of the Effects of Rainfall Variability and Groundwater Usage on the Hydrologic System in a Karst Terrain, Central Florida, USA

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Polarization Response in InAs Quantum Dots: Theoretical Correlation between Composition and Electronic Properties

III-V growth and surface conditions strongly influence the physical structure and resulting optical properties of self-assembled quantum dots (QDs). Beyond the design of a desired active optical wavelength, the polarization response of QDs is of particular interest for optical communications and quantum information science. Previous theoretical studies based on a pure InAs QD model failed to reproduce experimentally observed polarization properties. In this work, multi-million atom simulations are performed to understand the correlation between chemical composition and polarization properties of QDs. A systematic analysis of QD structural parameters leads us to propose a two layer composition model, mimicking In segregation and In-Ga intermixing effects. This model, consistent with mostly accepted compositional findings, allows to accurately fit the experimental PL spectra. The detailed study of QD morphology parameters presented here serves as a tool for using growth dynamics to engineer the strain field inside and around the QD structures, allowing tuning of the polarization response.Comment: 8 pages, 6 figures; accepted for publication in IOP Nanotechnology journa

Theory and design of Inx_{x}Ga1−x_{1-x}As1−y_{1-y}Biy_{y} mid-infrared semiconductor lasers: type-I quantum wells for emission beyond 3 μ\mum on InP substrates

We present a theoretical analysis and optimisation of the properties and performance of mid-infrared semiconductor lasers based on the dilute bismide alloy In$_{x}$Ga$_{1-x}$As$_{1-y}$Bi$_{y}$, grown on conventional (001) InP substrates. The ability to independently vary the epitaxial strain and emission wavelength in this quaternary alloy provides significant scope for band structure engineering. Our calculations demonstrate that structures based on compressively strained In$_{x}$Ga$_{1-x}$As$_{1-y}$Bi$_{y}$ quantum wells (QWs) can readily achieve emission wavelengths in the 3 -- 5 $\mu$m range, and that these QWs have large type-I band offsets. As such, these structures have the potential to overcome a number of limitations commonly associated with this application-rich but technologically challenging wavelength range. By considering structures having (i) fixed QW thickness and variable strain, and (ii) fixed strain and variable QW thickness, we quantify key trends in the properties and performance as functions of the alloy composition, structural properties, and emission wavelength, and on this basis identify routes towards the realisation of optimised devices for practical applications. Our analysis suggests that simple laser structures -- incorporating In$_{x}$Ga$_{1-x}$As$_{1-y}$Bi$_{y}$ QWs and unstrained ternary In$_{0.53}$Ga$_{0.47}$As barriers -- which are compatible with established epitaxial growth, provide a route to realising InP-based mid-infrared diode lasers.Comment: Submitted versio

Functional degradable polymers by radical ring-opening copolymerization of MDO and vinyl bromobutanoate : synthesis, degradability and post-polymerization modification

The synthesis of vinyl bromobutanoate (VBr), a new vinyl acetate monomer derivative obtained by the palladium-catalyzed vinyl exchange reaction between vinyl acetate (VAc) and 4-bromobutyric acid is reported. The homopolymerization of this new monomer using the RAFT/MADIX polymerization technique leads to the formation of novel well-defined and controlled polymers containing pendent bromine functional groups able to be modified via postpolymerization modification. Furthermore, the copolymerization of vinyl bromobutanoate with 2-methylene-1,3-dioxepane (MDO) was also performed to deliver a range of novel functional degradable copolymers, poly(MDO-co-VBr). The copolymer composition was shown to be able to be tuned to vary the amount of ester repeat units in the polymer backbone, and hence determine the degradability, while maintaining a control of the final copolymers’ molar masses. The addition of functionalities via simple postpolymerization modifications such as azidation and the 1,3-dipolar cycloaddition of a PEG alkyne to an azide is also reported and proven by 1H NMR spectroscopy, FTIR spectroscopy, and SEC analyses. These studies enable the formation of a novel class of hydrophilic functional degradable copolymers using versatile radical polymerization methods

Lifestyle travellers: Backpacking as a way of life

Scholarship on backpackers speculates some individuals may extend backpacking to a way of life. This article empirically explores this proposition using lifestyle consumption as its framing concept and conceptualises individuals who style their lives around the enduring practice of backpacking as ‘lifestyle travellers’. Ethnographic interviews with lifestyle travellers in India and Thailand offer an emic account of the practices, ideologies and social identity that characterise lifestyle travel as a distinctive subtype within backpacking. Departing from the drifter construct, which (re)constitutes this identity as socially deviant, the concept of lifestyle allows for a contemporary appraisal of these individuals’ patterns of meaningful consumption and wider insights into how ongoing mobility can lead to different ways of understanding identities and relating to place. Keywords: lifestyle consumption; backpacker; mobility; drifter; identit