Carbon nanotubes as fire gas sensors

Multi walled carbon nanotubes (MWCNTs) possess properties that make them particularly relevant for sensing applications in both the gas and liquid phase. This study presents an evaluation of cheap readily available CVD grown MWCNTs for use as fire gas sensors. Current fire detectors exploit heat and smoke detectors and it is hoped that the inclusion of gas detectors will increase the speed and reliability of detection. In order to prepare a variety of different MWCNTs a range of CVD synthesis were employed including an injected catalyst method where MWCNTs grew in dense mats from quartz substrates, MWCNTs were also synthesised using a sputtered Fe catalyst layer with acetylene as the carbon source which enabled control over the positioning of the growth. In each case, the growth parameters were varied until aligned growth was achieved. Doping of MWCNTs was also carried out as this may enhance and enable some control over the electrical properties of the CNTs; nitrogen was also added as a dopant by including 1,4-diazine as a precursor, and the effects on morphology of the MWCNTs produced were studied. The chemistry of the surface is also known to affect the sensing properties of CNTs. A batch of MWCNTs produced via the injected catalyst method were purifed by acid reflux, base washing and high temperature vacuum annealing, then modified with platinum or palladium metal nanoparticles via a reduction of the metal salts under hydrogen. MWCNTs were also coated with the polymer polyethyleneimine and with copperphthalocyanine. Prototype sensor devices were fabricated by electrophoretic deposition of these modified MWCNTs, and gas testing was carried out with the gases NO2, NH3, CO, H2 and C3H6. The mechanisms of sensing were investigated by repeating the tests at different temperatures, which revealed which sensing mechanisms were dominant and responses were compared between the differently modified MWCNTs. Sensor response was also investigated with a series of vapours to probe the dispersive and polar interactions on the MWCNT walls

The Genotype-Phenotype Correlation of the key features of Non-Proliferative Diabetic Retinopathy

Diabetic Retinopathy (DR) is a leading cause of visual impairment but its pathophysiology is not well understood. Moderate/severe non-proliferative DR (NPDR) is characterised by the presence of three features: deep haemorrhages (DH), venous beading (VB) and intraretinal microvascular abnormalities (IRMA). They are grouped together as risk factors for progression to sight threatening DR. It remains unclear whether these individual features have similar pathophysiologies, and whether they respond equally to anti-VEGF, a new therapy for NPDR. Optomap images of 504 NPDR eyes were examined to evaluate the distribution and prevalence of these three features. DNA samples from 199 patients with NPDR and 397 diabetic patients with no DR were collected. The genotype of specific candidate genes were evaluated in patients with DR, VB or IRMA vs no DR. Optical coherence tomography angiography (OCTA) images of 30 patients were examined for focal ischemia adjacent to VB and IRMA. The responses of these three features to anti-VEGF treatment were also re-examined in the images from the CLARITY trial. DH were present in most cases of NPDR. VB and IRMA did not always co-exist in the same eye and when they do, were often in different locations. VEGF, TGFb-1 and ARHGAP22 polymorphisms (ischaemia-related genes) were more common in patients with DR and IRMA, but not VB. Areas of focal ischaemia were more frequently adjacent to IRMA than to VB. DH and IRMA responded to anti-VEGF therapy but VB did not. These findings suggest that VB and IRMA do not share the same pathophysiology, and that IRMA are more likely to be ischaemic driven. Nonetheless, some IRMA may not be driven by ischaemia as they have no adjacent ischaemia on OCTA, do not carry the specific genotype, and do not respond to anti-VEGF. Furthermore, patients with VB may not benefit from anti-VEGF therapy

Journal d’automne de Louis MacNeice

Louis MacNeice’s long poem Autumn Journal appeared in 1939, to be finally translated into French by Adolphe Haberer and published in 2013 by Éditions Anagrammes as a bilingual edition, in its entirety. Individual sections only of this poem have appeared in earlier published translations in France. The journal consists of MacNeice’s reflections on autumn 1938 as it unfolded, both personal and political, and thus it is valuable as a poetic and historic ..

The role of auxiliary subunits in AMPA receptor function

Glutamate receptors of the AMPA-subtype mediate the majority of fast excitatory neurotransmission in the central nervous system (CNS). These receptors are associated with auxiliary proteins that have been shown to affect AMPA receptor (AMPAR) properties. Transmembrane AMPAR Regulatory Proteins (TARPs) were the first identified AMPAR auxiliary subunits, and since then, further auxiliary subunits continue to be identified. In this thesis, I investigate the effects of a novel auxiliary protein candidate – FRRS1L – on AMPAR function, as well as the involvement of TARPs in mediating AMPAR plasticity in a model of ischaemic stroke. I show that when co-expressed with both homomeric GluA1 and heteromeric GluA1/GluA2 AMPAR subunits in tsA201 cells, FRRS1L slows recovery from receptor desensitization, without significant effect on other AMPAR properties. When the prototypical TARP stargazin is additionally co-expressed, the effect of FRRS1L is lost and the receptor properties appear as if only stargazin were associated. I examine the endogenous expression of FRRS1L in the CNS, and find that it is highly abundant in multiple brain regions including the hippocampus, cortex and cerebellum. In cultured hippocampal neurons, overexpressed FRRS1L does not influence mEPSC amplitude or frequency. In a model of ischaemic stroke, direct ASIC1-a activation through lowering of the pH (acidosis) is sufficient to drive AMPAR plasticity in cultured hippocampal neurons. This manifests as a decrease in the GluA2 subunit, resulting in an increase of CP-AMPARs in the membrane. I show that this change in AMPAR subunit expression following acidosis is likely accompanied by an increase in TARP γ-8 expression. Using various techniques, I explore the change in CPAMPAR expression and cell excitability. I show that following acidosis, there is an increase in Ca2+ entry into the cells, which is likely mediated through CPAMPARs

Are income-related differences in active travel associated with physical environmental characteristics? A multi-level ecological approach

Background: Rates of active travel vary by socio-economic position, with higher rates generally observed among less affluent populations. Aspects of both social and built environments have been shown to affect active travel, but little research has explored the influence of physical environmental characteristics, and less has examined whether physical environment affects socio-economic inequality in active travel. This study explored income-related differences in active travel in relation to multiple physical environmental characteristics including air pollution, climate and levels of green space, in urban areas across England. We hypothesised that any gradient in the relationship between income and active travel would be least pronounced in the least physically environmentally-deprived areas where higher income populations may be more likely to choose active transport as a means of travel.<p></p> Methods: Adults aged 16+ living in urban areas (n = 20,146) were selected from the 2002 and 2003 waves of the UK National Travel Survey. The mode of all short non-recreational trips undertaken by the sample was identified (n = 205,673). Three-level binary logistic regression models were used to explore how associations between the trip being active (by bike/walking) and three income groups, varied by level of multiple physical environmental deprivation.<p></p> Results: Likelihood of making an active trip among the lowest income group appeared unaffected by physical environmental deprivation; 15.4% of their non-recreational trips were active in both the least and most environmentally-deprived areas. The income-related gradient in making active trips remained steep in the least environmentally-deprived areas because those in the highest income groups were markedly less likely to choose active travel when physical environment was ‘good’, compared to those on the lowest incomes (OR = 0.44, 95% CI = 0.22 to 0.89).<p></p> Conclusions: The socio-economic gradient in active travel seems independent of physical environmental characteristics. Whilst more affluent populations enjoy advantages on some health outcomes, they will still benefit from increasing their levels of physical activity through active travel. Benefits of active travel to the whole community would include reduced vehicle emissions, reduced carbon consumption, the preservation or enhancement of infrastructure and the presentation of a ‘normalised’ behaviour

In Touch with Things: Tourist Arts and the Mediation of Maori/European Relationships

This study re-evaluates theoretical approaches to the study of art forms and the mediation of social relationships in anthropology, through exploration of the emergence of tourist art forms in the Rotorua region of New Zealand, ancestral lands of the Arawa Maori people. Tourism began in Rotorua in the mid-nineteenth century, when Europeans visited to experience geothermal scenery, witness Maori social life and collect cultural artefacts as souvenirs. Returning to the scene of encounter to consider Maori/European negotiations surrounding the creation and acquisition of cultural artefacts, the research reconsiders items in museums and private collections in Britain and New Zealand as 'artefacts of encounter', to reveal ways in which acquisition was locally enabled and constrained. A case study of gifts presented to imperial authorities by Maori groups as a means of political negotiation points out the incommensurability of cross-cultural understandings of property, and the inequitable power relations that rendered such negotiations ineffectual. Throughout the twentieth century, the effects of European patronage relations upon Maori art forms are considered through comparative analyses of carved, woven and other souvenir forms and tour guiding services, concluding that whilst European patrons were frequently mean and belittling, their commissions opened up a space for a degree of innovation and experimentation not possible under customary Maori patronage. Engagements with new forms and technologies are explored through consideration of Maori adoption of photographic portraiture, popularised through the circulation of postcards since the late nineteenth century. Portraiture is compared to fibre arts, explored as a collective oeuvre formed between weavers linked through the transmission of skills passed down from the ancestral past into the present, a network which incorporates museum collections and non-Maori weavers. The concept of network is then deployed to query conventional approaches to art and material culture in anthropological thinking and museological practice

Iodine and Pregnancy

Iodine is a necessary element for the production of thyroid hormone. We will review the impact of dietary iodine status on thyroid function in pregnancy. We will discuss iodine metabolism, homeostasis, and nutritional recommendations for pregnancy. We will also discuss the possible effects of environmental contaminants on iodine utilization in pregnant women

Clinical Reasoning to Advance Medication Safety by Senior Nursing Students

Nursing students in their final year of their nursing education program are expected to administer medications to patients safely and competently. Currently, there is a lack of research with regard to how senior nursing students are using clinical reasoning to support medication safety in the clinical setting. This qualitative descriptive case study explored how senior nursing students applied critical thinking and clinical reasoning to support medication safety in their final clinical practicums. The study took place in 2019 and consisted of 13 face-to-face interviews with senior nursing students in their final clinical rotation. Six themes emerged from the interviews. Students described (1) administering medications safely by recognizing and clustering cues, (2) administering medications safely to the right patient in the context of care, (3) administering medications safely by determining the correct action, (4) administering medications safely to patients for the right reason, (5) reflecting on clinical reasoning experiences that supported medication safety, and (6) unit culture impact clinical reasoning about medication safety. Nursing students described how they used their clinical reasoning to support safe medication management and administration in clinical settings. Based on the findings from this study, we recommend that nursing education programs enhance opportunities for students to develop and reflect on their clinical reasoning about safe medication administration in clinical settings. Résumé Il est attendu que les étudiantes en sciences infirmières qui terminent leur formation soient en mesure d’administrer des médicaments de façon sécuritaire et compétente. Les recherches sur la façon dont les étudiantes finissantes en sciences infirmières utilisent le raisonnement clinique pour soutenir la sécurité pharmacologique en milieu clinique sont actuellement insuffisantes. Cette étude de cas descriptive et qualitative a exploré la manière dont ces étudiantes exerçaient la pensée critique et le raisonnement clinique pour assurer la sécurité pharmacologique au cours de leur dernier stage clinique. L’étude a été effectuée en 2019 et comprenait 13 entretiens individuels avec des étudiantes en sciences infirmières de 4e année lors de leur dernier stage en milieu clinique. Six thèmes sont ressortis de l’analyse de ces entretiens. Les étudiantes ont décrit administrer des médicaments de manière sécuritaire (1) en reconnaissant et en regroupant les indices, (2) en les administrant au bon patient dans le contexte des soins, (3) en déterminant la bonne action, (4) en les administrant aux patients pour la bonne raison,(5) en réfléchissant sur les expériences de raisonnement clinique qui ont soutenu la sécurité pharmacologique et (6) la culture de l’unité a eu un impact sur le raisonnement clinique concernant la sécurité pharmacologique. Les étudiantes en sciences infirmières ont expliqué comment elles ont utilisé leur raisonnement clinique pour favoriser la gestion et l’administration sécuritaires de médicaments dans les milieux cliniques. Compte tenu des résultats de cette étude, nous recommandons que les programmes de formation en sciences infirmières fournissent davantage d’occasions permettant aux étudiantes de développer et de réfléchir à leur raisonnement clinique en matière d’administration sécuritaire des médicaments dans les milieux de soins