Multiple Collections

This paper describes my interest in the artist’s multiple and the thesis body of work created in the exploration of them. I was especially interested in the relationship of individual components I could combine to form a singular object and how the resulting object had the ability to change through various methods of production and presentation. Also, in contrast to the idea that multiples are exact copies of each other I was interested in exploring the idea of the multiple being seen as an individual object. My interest in history and collecting unique objects from the past have heavily influenced the development of this work. Often, those objects at one time had a utilitarian function, but now because a certain amount of time has passed the objects have taken on the role of artifact. They have become a precious object that can no longer be used for the purpose they were created. This is a quality that I find fascinating. As an artist I find myself collecting these objects at an astounding level. This obsession with collecting has a direct connection with my current interest in multiples. The inspiration for this work came from many areas which include, but are not limited to the work of other artists, architects, graphic designers and specific periods of time when a certain visual aesthetic was highly valued, such as art nouveau, art deco, the arts and crafts movement, futurism, fluxus and modernism

Effects of wheat and oat-based whole grain foods on serum lipoprotein size and distribution in overweight middle aged people : a randomised controlled trial

Peer reviewedPublisher PD

The influence of structure and morphology on ion permeation in commercial silicone hydrogel contact lenses

The importance of the microstzructure of silicone hydrogels is widely appreciated but is poorly understood and minimally investigated. To ensure comfort and eye health, these materials must simultaneously exhibit both high oxygen and high water permeability. In contrast with most conventional hydrogels, the water content and water structuring within silicone hydrogels cannot be solely used to predict permeability. The materials achieve these opposing requirements based on a composite of nanoscale domains of oxygen‐permeable (silicone) and water‐permeable hydrophilic components. This study correlated characteristic ion permeation coefficients of a selection of commercially available silicone hydrogel contact lenses with their morphological structure and chemical composition. Differential scanning calorimetry measured the water structuring properties through subdivision of the freezing water component into polymer‐associated water (loosely bound to the polymer matrix) and ice‐like water (unimpeded with a melting point close to that of pure water). Small‐angle x‐ray scattering, and environmental scanning electron microscopy techniques were used to investigate the structural morphology of the materials over a range of length scales. Significant, and previously unrecognized, differences in morphology between individual materials at nanometer length scales were determined; this will aid the design and performance of the next generation of ocular biomaterials, capable of maintaining ocular homeostasis

A pilot in vivo evaluation of Sb(III) and Sb(V) genotoxicity using comet assay and micronucleus test on the freshwater fish, silver perch Bidyanus bidyanus (Mitchell, 1838)

Antimony (Sb) is a priority water pollutant known to be toxic to aquatic organisms at high concentrations. Environmental exposure, however, occurs most often at sub-lethal concentrations but very limited information is available on effects of sub-lethal, chronic exposure to Sb, which hinders reliable risk assessment and the setting of protective guidelines. In this pilot study, in vivo screening for Sb genotoxicity in the erythrocytes of the freshwater fish, silver perch (Bidyanus bidyanus) was conducted where fish were exposed to environmentally relevant and sub-lethal Sb concentrations of 0.4, 0.9 and 1.8 mg L−1 Sb(III), and 0.9, 2 and 5 mg L−1 Sb(V), for 14 d. Genotoxicity was assessed by both a single cell gel electrophoresis (SCGE) assay and a micronucleus (MN) test. The SCGE assay showed that all Sb(III) exposure concentrations induced a statistically significant non-dose-related increase in DNA damage after 2 d of exposure after which there was no further increase in DNA damage evident in relation to the control. Mortality of fish was 100 % in all Sb(III) exposures by 14 d. Clastogenic and/or aneugenic effects were not observed. The 1.8 mg L−1 Sb(III) exposure was the only Sb concentration at which a significant increase in the cytotoxicity index as measured by the ratio of polychromatic erythrocytes (PCEs) to normochromatic erythrocytes (NCE) was induced at 2 d exposure. For Sb(V) exposures, no significant genotoxic effects were observed using either assay, nor was the PCE/NCE altered. This pilot investigation has indicated that sub-lethal waterborne Sb(III) exposure manifests in genotoxic effects in freshwater fish species, which may have consequences for resilience and survival. Further study is needed for deeper insight into the relationship between Sb(III) and genotoxicity and the multiple biomarker responses that need assessment to evidence effects

Keeper Wear Mechanisms in the XIPS © 25-cm Neutralizer Cathode Assembly

Abstract: The 25-cm Xenon Ion Propulsion System (XIPS © ) thruster has been life tested for over 16,000 hours for communication satellite station keeping applications. The neutralizer cathode assembly (NCA) was observed to experience a significant amount of erosion by the end of the life test. While the NCA competed the test successfully and the life exceeds the requirement for the Boeing 702 satellite orbit-raising and station-keeping mission, erosion of the NCA keeper is a concern for longer duration NASA missions. The performance of a 25-cm neutralizer cathode has been investigated in the JPL cathode test facilities to determine the mechanisms responsible for the observed erosion in the thruster life test. Experiments with fast scanning emissive probes showed that the thruster life test started in the 4.5 kW high power mode with the neutralizer cathode operating normally in the quiescent "spot mode" where low erosion rates are observed. After 2880 hours of operation in the high power mode, the thruster operation was changed to the 2 kW low power station-keeping mode and continued in that mode for remaining 13,370 hours of the test. The emissive probe measurements indicate that the neutralizer cathode started out in the low power mode with significant plasma oscillations in the near cathode region. This behavior is indicative of "plume-mode" operation, which produces energetic ions and is well correlated to high keeper and cathode electrode erosion rates. A reduction in the neutralizer cathode orifice diameter was effective in re-establishing the spot-mode operation and eliminating the oscillations responsible for energetic ion production. Additional wear reduction can be achieved using alternative materials with lower sputtering yields. A wear test is now underway of a modified version of this neutralizer cathode that incorporates the smaller orifice diameter and a replacement of the standard molybdenum keeper material by tantalum. The wear test, combined with JPL's validated neutralizer cathode life models, is intended to show that the erosion rate of the present keeper and of the smaller cathode-plate orifice is insignificant thereby demonstrating sufficient neutralizer life for deep space missions

Canonical Wnt signals combined with suppressed TGFβ/BMP pathways promote renewal of the native human colonic epithelium

Background: A defining characteristic of the human intestinal epithelium is that it is the most rapidly renewing tissue in the body. However, the processes underlying tissue renewal and the mechanisms that govern their coordination have proved difficult to study in the human gut. Objective: To investigate the regulation of stem cell-driven tissue renewal by canonical Wnt and TGFβ/bone morphogenetic protein (BMP) pathways in the native human colonic epithelium. Design: Intact human colonic crypts were isolated from mucosal tissue samples and placed into 3D culture conditions optimised for steady-state tissue renewal. High affinity mRNA in situ hybridisation and immunohistochemistry were complemented by functional genomic and bioimaging techniques. The effects of signalling pathway modulators on the status of intestinal stem cell biology, crypt cell proliferation, migration, differentiation and shedding were determined. Results: Native human colonic crypts exhibited distinct activation profiles for canonical Wnt, TGFβ and BMP pathways. A population of intestinal LGR5/OLFM4-positive stem/progenitor cells were interspersed between goblet-like cells within the crypt-base. Exogenous and crypt cell-autonomous canonical Wnt signals supported homeostatic intestinal stem/progenitor cell proliferation and were antagonised by TGFβ or BMP pathway activation. Reduced Wnt stimulation impeded crypt cell proliferation, but crypt cell migration and shedding from the crypt surface were unaffected and resulted in diminished crypts. Conclusions: Steady-state tissue renewal in the native human colonic epithelium is dependent on canonical Wnt signals combined with suppressed TGFβ/BMP pathways. Stem/progenitor cell proliferation is uncoupled from crypt cell migration and shedding, and is required to constantly replenish the crypt cell population

Increasing SARS-CoV-2 seroprevalence among UK pediatric patients on dialysis and kidney transplantation between January 2020 and August 2021

Background Coronavirus disease 2019 (COVID-19) was officially declared a pandemic by the World Health Organisation (WHO) on 11 March 2020, as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly across the world. We investigated the seroprevalence of anti-SARS-CoV-2 antibodies in pediatric patients on dialysis or kidney transplantation in the UK.MethodsExcess sera samples were obtained prospectively during outpatient visits or haemodialysis sessions and analysed using a custom immunoassay calibrated with population age-matched healthy controls. Two large pediatric centres contributed samples.ResultsIn total, 520 sera from 145 patients (16 peritoneal dialysis, 16 haemodialysis, 113 transplantation) were analysed cross-sectionally from January 2020 until August 2021. No anti-SARS-CoV-2 antibody positive samples were detected in 2020 when lockdown and enhanced social distancing measures were enacted. Thereafter, the proportion of positive samples increased from 5% (January 2021) to 32% (August 2021) following the emergence of the Alpha variant. Taking all patients, 32/145 (22%) were seropositive, including 8/32 (25%) with prior laboratory-confirmed SARS-CoV-2 infection and 12/32 (38%) post-vaccination (one of whom was also infected after vaccination). The remaining 13 (41%) seropositive patients had no known stimulus, representing subclinical cases. Antibody binding signals were comparable across patient ages and dialysis versus transplantation and highest against full-length spike protein versus spike subunit-1 and nucleocapsid protein.ConclusionsAnti-SARS-CoV-2 seroprevalence was low in 2020 and increased in early 2021. Serological surveillance complements nucleic acid detection and antigen testing to build a greater picture of the epidemiology of COVID-19 and is therefore important to guide public health responses

Serum Levels of Proinflammatory Lipid Mediators and Specialized Proresolving Molecules Are Increased in Patients With Severe Acute Respiratory Syndrome Coronavirus 2 and Correlate With Markers of the Adaptive Immune Response

BACKGROUND: Specialized proresolution molecules (SPMs) halt the transition to chronic pathogenic inflammation. We aimed to quantify serum levels of pro- and anti-inflammatory bioactive lipids in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients, and to identify potential relationships with innate responses and clinical outcome. METHODS: Serum from 50 hospital admitted inpatients (22 female, 28 male) with confirmed symptomatic SARS-CoV-2 infection and 94 age- and sex-matched controls collected prior to the pandemic (SARS-CoV-2 negative), were processed for quantification of bioactive lipids and anti-nucleocapsid and anti-spike quantitative binding assays. RESULTS: SARS-CoV-2 serum had significantly higher concentrations of omega-6-derived proinflammatory lipids and omega-6- and omega-3-derived SPMs, compared to the age- and sex-matched SARS-CoV-2-negative group, which were not markedly altered by age or sex. There were significant positive correlations between SPMs, proinflammatory bioactive lipids, and anti-spike antibody binding. Levels of some SPMs were significantly higher in patients with an anti-spike antibody value >0.5. Levels of linoleic acid and 5,6-dihydroxy-8Z,11Z,14Z-eicosatrienoic acid were significantly lower in SARS-CoV-2 patients who died. CONCLUSIONS: SARS-CoV-2 infection was associated with increased levels of SPMs and other pro- and anti-inflammatory bioactive lipids, supporting the future investigation of the underlying enzymatic pathways, which may inform the development of novel treatments

Perceptions and Experiences of the University of Nottingham Pilot SARS-CoV-2 Asymptomatic Testing Service: A Mixed-Methods Study

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. We aimed to explore student and staff perceptions and experiences of a pilot SARS-CoV-2 asymptomatic testing service (P-ATS) in a UK university campus setting. This was a mixed-method study comprised of an online survey, and thematic analysis of qualitative data from interviews and focus groups conducted at the mid-point and end of the 12-week P-ATS programme. Ninety-nine students (84.8% female, 70% first year; 93.9% P-ATS participants) completed an online survey, 41 individuals attended interviews or focus groups, including 31 students (21 first year; 10 final year) and 10 staff. All types of testing and logistics were highly acceptable (virus: swab, saliva; antibody: finger prick) and 94.9% would participate again. Reported adherence to weekly virus testing was high (92.4% completed ≥6 tests; 70.8% submitted all 10 swabs; 89.2% completed ≥1 saliva sample) and 76.9% submitted ≥3 blood samples. Students tested to “keep campus safe”, “contribute to national efforts to control COVID-19”, and “protect others”. In total, 31.3% had high anxiety as measured by the Generalized Anxiety Disorder scale (GAD-7) (27.1% of first year). Students with lower levels of anxiety and greater satisfaction with university communications around P-ATS were more likely to adhere to virus and antibody tests. Increased adherence to testing was associated with higher perceived risk of COVID-19 to self and others. Qualitative findings revealed 5 themes and 13 sub-themes: “emotional responses to COVID-19”, “university life during COVID-19”, “influences on testing participation”, “testing physical and logistical factors” and “testing effects on mental wellbeing”. Asymptomatic COVID-19 testing (SARS-CoV-2 virus/antibodies) is highly acceptable to students and staff in a university campus setting. Clear communications and strategies to reduce anxiety are likely to be important for testing uptake and adherence. Strategies are needed to facilitate social connections and mitigate the mental health impacts of COVID-19 and self-isolation

Perceptions and Experiences of the University of Nottingham Pilot Asymptomatic Testing Service: A Mixed-Methods Study

We aimed to explore student and staff perceptions and experiences of a pilot COVID-19 asymptomatic testing service (P-ATS) in a UK university campus setting. This was a mixed-method study comprised of an online survey, and thematic analysis of qualitative data from interviews and focus groups conducted at the end of the 12-week P-ATS programme. Ninety-nine students (84.8% female, 70% first year; 93.9% P-ATS participants) completed an online survey, 41 individuals attended interviews or focus groups, including 31 students (21 first year; 10 final year) and 10 staff. All types of testing and logistics were highly acceptable (virus: swab, saliva; antibody: finger prick) and 94.9% would participate again. Reported adherence to weekly virus testing was high (92.4% completed ≥6 tests; 70.8% submitted all 10 swabs; 89.2% completed ≥1 saliva sample) and 76.9% submitted ≥3 blood samples. Students tested to ‘keep campus safe’, ‘contribute to national efforts to control COVID-19’, and ‘protect others’. 31.3% had high anxiety as measured by the Generalized Anxiety Disorder scale (GAD-7) (27.1% of first year). Students with lower levels of anxiety and greater satisfaction with university communications around P-ATS were more likely to adhere to virus and antibody tests. Increased adherence to testing was associated with higher perceived risk of COVID-19 to self (virus) and others (antibody). Qualitative findings revealed 5 themes and 13 sub-themes: ‘emotional responses to COVID-19’, ‘university life during COVID-19’, ‘influences on testing participation’, ‘testing physical and logistical factors’ and ‘testing effects on mental wellbeing’. Asymptomatic COVID-19 testing (virus/antibodies) is highly acceptable to students and staff in a university campus setting. Clear communications and support for mental wellbeing is likely to be important for testing uptake and adherence. Strategies are needed to facilitate social connections and mitigate the mental health impacts of COVID-19 and self-isolation