1522 research outputs found
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Einstein's Oxford Blackboard : A Unique Historical Artefact
Get PDFEinstein's blackboard is a well-known exhibit at the History of Science Museum at Oxford University. However, it is much less well known that the writing on the board provides a neat summary of a work of historic importance, Einstein's 1931 model of the expanding universe. As a visual representation of one of the earliest models of the universe to be proposed in the wake of Hubble's observations of the nebulae, the blackboard provides an intriguing snapshot of a key moment in modern astronomy and cosmology. In addition, one line on the blackboard that is not in Einstein's 1931 paper casts useful light on some anomalies in the calculations of that paper
Circulating Angiogenic and Senescent T Cells in Ageing and Frailty
No full textAgeing and frailty represent an increasing challenge for societies worldwide, with a growing emphasis on identifying their underlying pathophysiologies and prospects for intervention. Although not part of frailty based on some definitions employed, there is an important cardiovascular dimension to frailty. T lymphocyte subsets have been implicated both positively and negatively in vascular health and age-related vascular disease. There is evidence a circulating T cell subset exists (CD31+ angiogenic T cells) which may play a role in vascular maintenance and repair. On the other hand, there also exists a population of T cells that display pro-inflammatory function (CD28NULL senescent T cells). Ageing, an established cardiovascular risk factor has been linked with decreasing numbers of circulating CD31+ T cells and increases in CD28NULL T cells. Using flow cytometry, we have examined the effects of ageing and frailty on these cells and their discrete subsets. We have also isolated CD31+ and CD31- T cells from young adults, investigated their cytokine secretion profile and T cell differentiation state. Our key findings include (1) a progressive decrease in CD31+ T cells with ageing and a paradoxical increase in age-matched frail older adults, (2) increased CD28NULL T cells in frail older adults, which is particularly prominent in the CD8+ T cell pool (3) higher secretion of angiogenic and pro-inflammatory cytokines from CD31+ than CD31- T cells (4) CD31+ T cells exist across the T cell differentiation spectrum with considerable proportions present in the senescent T cell pool. Overall, our findings indicate that CD31+ T cells have more complex functional and phenotypic characteristics than previously described, and these characteristics should be considered in future studies investigating these cells in disease states. We have identified CD8+CD28NULL T cells as a frailty associated biomarker that may be used to track immune changes in intervention studies concerning frail populations
PRINTING OF DISSOLVING MICRONEEDLE ARRAYS USING AEROSOL JET PRINTING TECHNOLOGY FOR TRANSDERMAL DELIVERY
Get PDFMicroneedles have been extensively studied for the transdermal delivery of drugs over the last number of decades. They are an attractive means for drug delivery as they are painless and can facilitate the delivery of drugs which would not ordinarily penetrate the skin. In recent times, additive manufacturing techniques such as stereolithography have been used to fabricate microneedles. However, research to date is limited to solid, hollow and coated microneedles 1, 2 . Stereolithography methods do not lend themselves well to dissolving microneedle fabrication. The traditional method of fabricating dissolving microneedles by micro-moulding techniques has its drawbacks such as variability in the administered dose, non reproducibility, needle breakage upon removing from moulds and long curing times. Aerosol Jet Printing is an additive manufacturing technique which may overcome these issues due to its high reproducibility and precision. Structures are formed as the instrument creates an aerosol mist and deposits the ink dropwise in a controlled manner onto a substrate, thus building up layers to form a microneedle array. The instrument gives freedom of design, in terms of needle shape and spacing, allows for increased drug loading capacity as no backing layer is present and can print formulations with a wide range of viscosities. Here we report the manufacture of the first dissolving microneedle array fabricated by Aerosol Jet Printing. The formulation is a mixture containing PVP, trehalose, glycerol and water. The formulation characteristics include a measured viscosity of 3.82 ± 0.22 cP and surface tension of 63.76 ± 0.25 mN/m. The formulation was deposited onto a double sided polished silicon wafer via ultrasonic atomisation. The printed microneedle array consisted of 64 needles which was made up of 75 layers of the deposited formulation. Print times for a full array is less than 150 min. The fabricated needles are printed at temperatures below 50° C, therefore, the technique is suitable for many thermolabile active ingredients. The potential for the fabricated microneedle arrays to penetrate porcine skin is currently being evaluated. Future work will focus on the inclusion of therapeutic peptide molecules into the microneedle array and the study of the release properties from the array using Franz diffusion cells
Creating a transdisciplinary landscape biography of Kilrossanty parish, Comeragh Mountains, Ireland, using GIS mapping
Get PDFLandscape biographies have gained in popularity in recent years as a holistic assessment tool to enable local government planning and also to promote a community’s sense of place and identity. The approach however, has yet to be applied to the Republic of Ireland’s unique historic and cultural landscape. This thesis aims to address this omission by exploring how previous biographical approaches can be adapted and applied to Ireland, by using the region of Kilrossanty parish, situated in County Waterford in the south east of the island, as a case study. The new methodology intends to complement the current governmental approach to landscape assessment in Ireland which focuses solely on Landscape Character Assessments. The thesis argues that the complexities of the Irish historical background require a more layered approach for which a biography is more appropriate. By conducting transdisciplinary fieldwork, an Irish landscape biographical model has been produced focusing upon the landscape’s structural transformations and identification of its authors who have been categories to better reflect the societal and political strata of this formerly colonised country
Deep Learning for Autonomic SLA Management of NFV Resources towards Next Generation Networks
Get PDFRecent advancements in the domain of Network Function Virtualization (NFV), and the
rollout of next-generation networks have led to a new era of applications delivered via a
paradigm of flexible and softwarized communication networks. This has opened the market
to a wider movement towards virtualized applications and services in key verticals such
as automated vehicles, smart grid, virtual reality (VR), Internet of Things (IoT), industry
4.0, telecommunications, etc. This has necessitated the requirement for the upkeep of
latency-critical application architectures in future networks and communications. While
Cloud service providers recognize the evolving mission-critical requirements in latency
sensitive verticals, there is a wide gap to bridge the Quality of Service (QoS) constraints
for the end-user experience. Most latency-critical services are over-provisioned on all
fronts to offer reliability, which is inefficient towards scalability in the long run.
The research presented in this work aims to address the challenges behind effectively
managing the trade-off between efficiency and reliability when considering latency critical
applications based in a high-availability network slice in next-generation softwarized
networks. In the course of research done in this work, we design and develop algorithms
to address the complexity towards meeting QoS demands in serving upcoming verticals
through the softwarised network architecture, and develop deep learning based frameworks
for proactive SLA management in the use-case of a latency-critical NFV application. We
utilize data from a real-world deployment to configure and draft a realistic set of Service
Level Objectives (SLOs) for a voice based NFV application, and leverage various machine
learning based methodologies to proactively identify and predict multiple categories of
SLO breaches associated with an application state. With this, we aim to gain granular
SLA and SLO violation insights, enabling us to study and mitigate their impact and inform
precision in drafting proactive scaling policies in future
A bibliometric analysis of the literature on the market orientation of higher education institutions
Get PDFPurpose The purpose of this paper is to provide a bibliometric analysis of the research on market orientation (MO) as it relates to higher education institutions (HEI). Methodology The Scopus database was used to identify 170 relevant publications over a thirty-year period. The Scopus database functionality and VOSviewer software were subsequently used to address the research purpose. Findings Identifies the journal that has published the maximum number of papers on market orientation as it relates to higher education; the years which have the maximum number of papers published; the most cited papers, authors and journals; the most prolific authors and the most prolific higher education institutions and countries; the authors which have co-authored the maximum, with other authors; the countries’ authors which have co-authored the maximum with the authors of other countries; the most frequently appearing keywords and which citations, journals, authors have been co-cited to the greatest degree. Research Implications This study contributes to the existing literature on MO in HE. A comprehensive and reliable picture of the research area is provided using bibliometric techniques. The results can help in guiding authors interested in conducting future research on this topic
Enantioselective Synthesis of Biologically Relevant Molecules Using Catalysis in Continuous Flow
Get PDFThe overarching aim of this work was to engineer and develop a continuous flow process for the synthesis of 3-substituted-3-hydroxyoxindoles which are core moieties of biological importance. The first part of this work involved transferring the L-leucinol catalysed aldol reaction of isatin with acetone from batch to continuous flow for the first time. An initial batch solvent screening revealed neat acetone as the media best suited in flow. Solvents with Kamlet-Taft basicity (β)>0.6 and proticity (α) ≈ 0 had a higher solubility of isatin but poor reaction performance while solvents with β<0.2 and α< 0.6 performed excellently in the reaction albeit with poor isatin solubility. Addition of 10 equivalents of water improved the neat reaction to afford 94% yield in 93% ee at 20°C after 48 h.
Having identified an ideal solvent in the batch screening, a PTFE tubing reactor was fabricated, and the identified optimal batch conditions transferred to flow and optimised. Complete conversions were obtained in 12 h residence time at 40°C without a loss in enantioselectivity. Other variants of isatin were also tested in batch and flow and in all cases, the reaction proceeded excellently with the flow reaction outperforming that in batch. Some isatin derivatives required a 4-fold dilution to achieve a solubility transferable to continuous flow, however, excellent yields and enantioselectivities were obtained in most cases.
A second part of the substrate scope studies sought to examine the diastereoselective and regioselective potentials of the L-leucinol catalysed reactions of isatin with enolisable ketones for the first time. Reactions with symmetrical ketones, unsymmetrical ketones and cyclic ketones were carried out in batch and interestingly, high enantioselectivity and diastereoselectivity was observed with symmetrical ketones and cyclic ketones. Reactions with unsymmetrical ketones also proceeded smoothly but afforded two regioisomers indicating leucinol is a non-regioselective organocatalyst.
Another major part of this work involved the use of aerosol jet printing and stereolithography (SLA) 3D printing for rapid prototyping of moulds which would be utilised for soft lithography fabrication of microfluidic devices. Moulds with the desired channels size (300 μm width and height) were printed using the SLA 3D printer, silanised and successfully used to fabricate PDMS based microfluidic devices. While reactions through our PDMS device were not successful, the proof of concept was demonstrated and could be extended to other replica moulding techniques which utilise polymers with better solvent and chemical resistant properties
Aging research and design thinking: How interdisciplinary collaboration and stakeholder engagement can drive trainees’ research impact
Get PDFAging research is increasingly seeking to solve complex challenges in a context where discovery to implementation and impact may take decades. Design thinking is an approach to problem solving that can accelerate impact by incorporating multiple perspectives, including those of interdisciplinary colleagues, stakeholders and end-users (including older adults), into research development and implementation. The objective of this study was to measure the research impact for 26 trainees (graduate students and postdoctoral fellows) who received funding and in-kind support from a central aging research institute for at least one year over the course of a five-year period (2017-2021). Trainees had varying uptake of these approaches to their aging research. Trainee respondents completed a survey that asked about interdisciplinary collaboration and design thinking approaches, including engagement with older adults, caregivers, and other stakeholders. Here we describe how these approaches were related to patterns in trainee success; trainees whose funded research involved more new collaborators - both within and outside of their discipline – reported more publications, conference presentations and invited talks associated with their research. Further, qualitative responses to survey questions regarding the impact of interdisciplinary and stakeholder interactions describe how trainees were able to make adaptive changes to methods, variables included for analysis, knowledge translation and implementation strategies. We conclude that, in this sample, trainees who engaged in greater interdisciplinary and stakeholder engagement had greater research impact, as measured via traditional academic metrics and more nuanced assessment of knowledge mobilization and implementatio
Whey protein microgels for stabilisation of foams
Get PDFRheological, foaming and foam textural properties of whey protein isolate (WPI) microgels formed via cold-set gelation were investigated and compared with those of native WPI foams. The effect of CaCl2 concentration and cross-linking time on microgel formation was studied assessing particle size, rheology and foamability. Foams, produced by mechanical whipping, were assessed by overrun, stability and texture. WPI had lower viscosity than the microgels, producing foams with greater overrun. For microgels, higher concentrations of CaCl2 formed smaller particles and decreased microgel viscosity, causing higher overrun. Increasing cross-linking time from 0 to 24 h significantly (P 2 years. This demonstrates that WPI microgels can be used as a novel functional application for creating ultra-stable foams for use in the food industry
Aspects of low fertiliser nitrogen input seasonal pasture-based milk production
Get PDFSynthetic fertiliser nitrogen (N) is a significant contributor to the environmental footprints of dairy products from pasture-based systems. Biological N fixation (BNF) in association with white clover can reduce dependency on fertiliser N and consequently lower environmental footprints. This thesis investigated aspects of white clover management strategies in seasonal pasture-based dairy production. One experiment quantified the supply of background N in Irish permanent grasslands. Another investigated the productivity of white clover-based grassland for milk production based on several systems-scale studies. A third experiment examined the effect of fertiliser N input to grass-clover swards and calving date on the productivity of pasture-based dairy production. Mean background N was 141 kg ha-1 across Irish grasslands and varied both temporally and spatially during the growing season. The background N was influenced by soil physical and chemical properties along with meteorological factors. Dairy production based on low-input clover-based grassland receiving fertiliser N input of approximately 97 kg N ha-1 was similar to N-fertilised grass-only receiving 244 kg N ha-1 in several systems-scale studies. Mean annual and seasonal pasture production per ha and milk production per cow was similar between these two grassland systems. Sward white clover and BNF decreased with increasing annual N fertilisation. A mean calving date in mid-February is recommended for zero-fertiliser N input white clover-based systems. A later than typical calving date (in mid-April) resulted in inefficient use of pasture for milk production in a zero-fertiliser N white clover-based system. Extending lactation into the following winter resulted in lower concentrations of milk constituents and affected processing characteristics of late lactation milk. Nevertheless, maximising overwintering of stolon and root dry matter mass by tight winter grazing increased white clover productivity and persistence in grassland. There is considerable potential for milk production on clover-based swards receiving low or no input of fertiliser N