The impact of first pregnancy and delivery on pelvic floor dysfunction

Background: The first childbirth has the greatest impact on a woman’s pelvic floor when major changes occur. The aim of this study was to comprehensively describe pelvic floor dysfunction (PFD) in young nulliparous women, and its correlation with postnatal pathology. Methods: A prospective study was performed at Cork University Maternity Hospital, Ireland. Initially 1484 nulliparous women completed the validated Australian Pelvic Floor Questionnaire at 15 weeks’ gestation and repeatedly at one year postnatally (N=872). In the second phase, at least one year postnatally, 202 participants without subsequent pregnancies attended the clinical follow up which included: pelvic organ prolapse quantification, a 3D-Transperineal ultrasound scan and collagen level assessment. Results: A high pre-pregnancy prevalence of various types of PFD was detected, which in the majority of cases persisted postnatally and included multiple types of PFD. The first birth had a negative impact on severity of pre-pregnancy symptoms in <15% of cases. Apart from prolapse, vaginal delivery, including instrumental delivery did not increase the risk of PFD symptoms, where as Caesarean section was protective for all types of PFD. The first birth had a bigger impact on pre-existing symptoms of overactive bladder compared to stress urinary incontinence. Pelvic organ prolapse is extremely prevalent in young primiparous women, however usually it is low grade and asymptomatic. Congenital factors and high collagen type III levels play an important role in the aetiology of pelvic organs prolapse. Levator ani trauma is present in one in three women after the first pregnancy and delivery. Conclusion: The main damage to the pelvic floor most likely occurs due to an undiagnosed congenital intrinsic weakness of the pelvic floor structures. PFD is highly associated with first childbirth, however it seems that pregnancy and delivery are contributing factors only which unmask the congenital intrinsic weakness of the pelvic floor support.

Optimised crystal morphologies for active pharmaceutical ingredients and related studies

The majority of active pharmaceutical ingredients (APIs) are crystalline solids in their pure forms. Crystalline solids have definable morphologies, i.e. shape and size. Crystal morphology is determined by both the internal structure of the crystals and external factors during growth from solution. The morphology of a crystal batch can affect key processes during manufacturing. Companies generally accept whatever morphology the manufacturing process provides and deal with any subsequent problems by costly trouble‒shooting. Rational design of optimised morphologies for crystalline pharmaceutical solids would be a very significant technical and commercial advance. Chapter one introduces the concept of crystal nucleation and growth. The phenomenon of polymorphism alongside the causes and impact is discussed. A summary of the scope of instrumentation used in the investigation of crystal polymorphism and morphology, including crystal size distribution (CSD), is also included. Chapter two examines the research carried out during an exploration of the optimum crystallisation parameters of phenacetin. Following a morphological study, the impact this induces on particle density and flow properties is examined. The impact of impurities on the crystallisation properties of phenacetin is investigated. Significantly, the location of impurities within individual crystals is also studied. The third chapter describes an industrial collaboration looking at the resolution and polymorphic study of trometamol and lysine salts of ketoprofen and 2‒phenylpropionic acid (2‒PPA). Chapter four incorporates a solid state study on three separate compounds: 2‒chloro‒4‒nitroaniline, 4‒hydroxy‒N‒phenylbenzenesulfonamide and N‒acetyl‒D‒glucosamine‒6‒O‒sulfate. 2‒Chloro‒4‒nitroaniline and 4‒hydroxy‒N‒phenylbenzenesulfonamide both produced interesting, extreme morphologies which warranted further investigation as part of a collaborative study. Following a summarisation of results in chapter five, chapter six contains the full experimental details, incorporating spectral and other analytical data for all compounds synthesised during the course of the research.

Public evaluations of novel food technologies: a qualitative citizen-scientist deliberative discourse approach

This qualitative research expands understanding of how information about a range of Novel Food Technologies (NFTs) is used and assimilated, and the implications of this on the evolution of attitudes and acceptance. This work enhances theoretical and applied understanding of citizens’ evaluative processes around these technologies. The approach applied involved observations of interactive exchanges between citizens and information providers (i.e. food scientists), during which they discussed a specific technology. This flexible, yet structured, approach revealed how individuals construct meaning around information about specific NFTs. A rich dataset of 42 ‘deliberate discourse’ and 42 postdiscourse transcripts was collected. Data analysis encompassed three stages: an initial descriptive account of the complete dataset based on the top-down bottom-up (TDBU) model of attitude formation, followed by inductive and deductive thematic analysis across the selected technology groups. The hybrid thematic analysis undertaken identified a Conceptual Model, which represents a holistic perspective on the influences and associated features directing ‘sense-making’ and ultimate evaluations around the technology clusters. How individuals make sense of these technologies is shaped by: their beliefs, values and personal characteristics; their perceptions of power and control over the application of the technology; and, the assumed relevance of the technology and its applications within different contexts. These influences form the frame for the creation of sense-making around the technologies. Internal negotiations between these influences are evident and evaluations are based on the relative importance of each influence to the individual, which tend to contribute to attitude ambivalence and instability. The findings indicate the processes of forming and changing attitudes towards these technologies are: complex; dependent on characteristics of the individual, technology, application and product; and, impacted by the nature and forms of information provided. Challenges are faced in engaging with the public about these technologies, as levels of knowledge, understanding and interest vary.

Chamber investigations of atmospheric mercury oxidation chemistry

Mercury is a potent neurotoxin even at low concentrations. The unoxidised metal has a high vapour pressure and can circulate through the atmosphere, but when oxidised can deposit and be accumulated through the food chain. This work aims to investigate the oxidation processes of atmospheric Hg0(g). The first part describes efforts to make a portable Hg sensor based on Cavity Enhanced Absorption Spectroscopy (CEAS). The detection limit achieved was 66 ngm−3 for a 10 second averaging time. The second part of this work describes experiments carried out in a temperature controlled atmospheric simulation chamber in the Desert Research Institute, Reno, Nevada, USA. The chamber was built around an existing Hg CRDS system that could measure Hg concentrations in the chamber of<100 ngm−3 at 1 Hz enabling reactions to be followed. The main oxidant studied was bromine, which was quantified with a LED based CEAS system across the chamber. Hg oxidation in the chamber was found to be mostly too slow for current models to explain. A seven reaction model was developed and tested to find which parameters were capable of explaining the deviation. The model was overdetermined and no unique solution could be found. The most likely possibility was that the first oxidation step Hg + Br →HgBr was slower than the preferred literature value by a factor of two. However, if the more uncertain data at low [Br2] was included then the only parameter that could explain the experiments was a fast, temperature independent dissociation of HgBr some hundreds of times faster than predicted thermolysis or photolysis rates. Overall this work concluded that to quantitatively understand the reaction of Hg with Br2, the intermediates HgBr and Br must be measured. This conclusion will help to guide the planning of future studies of atmospheric Hg chemistry.

Subterfuge-safe trust management for delegation of permissions in open environments

Open environments involve distributed entities interacting with each other in an open manner. Many distributed entities are unknown to each other but need to collaborate and share resources in a secure fashion. Usually resource owners alone decide who is trusted to access their resources. Since resource owners in open environments do not have a complete picture of all trusted entities, trust management frameworks are used to ensure that only authorized entities will access requested resources. Every trust management system has limitations, and the limitations can be exploited by malicious entities. One vulnerability is due to the lack of globally unique interpretation for permission specifications. This limitation means that a malicious entity which receives a permission in one domain may misuse the permission in another domain via some deceptive but apparently authorized route; this malicious behaviour is called subterfuge. This thesis develops a secure approach, Subterfuge Safe Trust Management (SSTM), that prevents subterfuge by malicious entities. SSTM employs the Subterfuge Safe Authorization Language (SSAL) which uses the idea of a local permission with a globally unique interpretation (localPermission) to resolve the misinterpretation of permissions. We model and implement SSAL with an ontology-based approach, SSALO, which provides a generic representation for knowledge related to the SSAL-based security policy. SSALO enables integration of heterogeneous security policies which is useful for secure cooperation among principals in open environments where each principal may have a different security policy with different implementation. The other advantage of an ontology-based approach is the Open World Assumption, whereby reasoning over an existing security policy is easily extended to include further security policies that might be discovered in an open distributed environment. We add two extra SSAL rules to support dynamic coalition formation and secure cooperation among coalitions. Secure federation of cloud computing platforms and secure federation of XMPP servers are presented as case studies of SSTM. The results show that SSTM provides robust accountability for the use of permissions in federation. It is also shown that SSAL is a suitable policy language to express the subterfuge-safe policy statements due to its well-defined semantics, ease of use, and integrability.

Beyond simple imaging with energetic beams – nanopatterning, correlative microscopy and statistical analysis of inclusions

Electron microscopy (EM) has advanced in an exponential way since the first transmission electron microscope (TEM) was built in the 1930’s. The urge to ‘see’ things is an essential part of human nature (talk of ‘seeing is believing’) and apart from scanning tunnel microscopes which give information about the surface, EM is the only imaging technology capable of really visualising atomic structures in depth down to single atoms. With the development of nanotechnology the demand to image and analyse small things has become even greater and electron microscopes have found their way from highly delicate and sophisticated research grade instruments to key-turn and even bench-top instruments for everyday use in every materials research lab on the planet. The semiconductor industry is as dependent on the use of EM as life sciences and pharmaceutical industry. With this generalisation of use for imaging, the need to deploy advanced uses of EM has become more and more apparent. The combination of several coinciding beams (electron, ion and even light) to create DualBeam or TripleBeam instruments for instance enhances the usefulness from pure imaging to manipulating on the nanoscale. And when it comes to the analytic power of EM with the many ways the highly energetic electrons and ions interact with the matter in the specimen there is a plethora of niches which evolved during the last two decades, specialising in every kind of analysis that can be thought of and combined with EM. In the course of this study the emphasis was placed on the application of these advanced analytical EM techniques in the context of multiscale and multimodal microscopy – multiscale meaning across length scales from micrometres or larger to nanometres, multimodal meaning numerous techniques applied to the same sample volume in a correlative manner. In order to demonstrate the breadth and potential of the multiscale and multimodal concept an integration of it was attempted in two areas: I) Biocompatible materials using polycrystalline stainless steel and II) Semiconductors using thin multiferroic films. I) The motivation to use stainless steel (316L medical grade) comes from the potential modulation of endothelial cell growth which can have a big impact on the improvement of cardio-vascular stents – which are mainly made of 316L – through nano-texturing of the stent surface by focused ion beam (FIB) lithography. Patterning with FIB has never been reported before in connection with stents and cell growth and in order to gain a better understanding of the beam-substrate interaction during patterning a correlative microscopy approach was used to illuminate the patterning process from many possible angles. Electron backscattering diffraction (EBSD) was used to analyse the crystallographic structure, FIB was used for the patterning and simultaneously visualising the crystal structure as part of the monitoring process, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to analyse the topography and the final step being 3D visualisation through serial FIB/SEM sectioning. II) The motivation for the use of thin multiferroic films stems from the ever-growing demand for increased data storage at lesser and lesser energy consumption. The Aurivillius phase material used in this study has a high potential in this area. Yet it is necessary to show clearly that the film is really multiferroic and no second phase inclusions are present even at very low concentrations – ~0.1vol% could already be problematic. Thus, in this study a technique was developed to analyse ultra-low density inclusions in thin multiferroic films down to concentrations of 0.01%. The goal achieved was a complete structural and compositional analysis of the films which required identification of second phase inclusions (through elemental analysis EDX(Energy Dispersive X-ray)), localise them (employing 72 hour EDX mapping in the SEM), isolate them for the TEM (using FIB) and give an upper confidence limit of 99.5% to the influence of the inclusions on the magnetic behaviour of the main phase (statistical analysis).

The human papillomavirus and cancer: a multiphase study investigating preventative behaviours in young males

Background: The Human Papillomavirus (HPV) is one of the world’s most common sexually transmitted infections, and a causative factor of oropharyngeal, anal and penile cancers in males. Worldwide, an estimated 39,000 HPV-associated cancers occur each year in men. The highest rates of HPV infection are found in adults aged 18 to 28 years. Clinical evidence indicates that use of a condom in addition to obtaining the HPV vaccine provides the greatest protection from HPV infections. Aim: To explore young men’s attitudes, beliefs, and behavioural intention in relation to receiving the HPV vaccine and using a condom correctly and consistently. Collectively, both behaviours are linked to the prevention of HPV transmission and associated infections with HPV. Method: A multi- phase study, underpinned by the Theory of Planned Behaviour, involving a qualitative belief elicitation, pilot, and quantitative cross-sectional study was conducted. A belief elicitation (n=12) phase was used to generate items to include in a newly developed research instrument. Post pilot the research instrument was utilised in a cross sectional online survey to explore the attitudes, beliefs, and behavioural intention of young men (n= 359) with regard to receiving the HPV vaccine, and using a condom correctly and consistently. Data Collection: Data collection took place over a three month time frame. Male participants were recruited from a university in Southern Ireland via a student email system, as well as posting advertisements on numerous health, social and sports websites. Sample: Three hundred and fifty nine male participants aged 18- 28 years completed the online questionnaire. Data Analysis: Data were analysed using SPSS. Descriptive, correlational, multiple and hierarchical regression analysis were performed on the indirect and direct variables of the Theory of Planned Behaviour i.e. attitude, subjective norm, perceived behavioural control, and intention. Status variables were also included in descriptive analysis and hierarchical regressions. Findings are presented through text and graphical representation. Results: Alarming sexual health statistics identified that only 44.3% of participants always used a condom, and 78.6% never used a condom for oral sex. Furthermore, findings reveal that the constructs of the Theory of Planned Behaviour adequately measure male’s attitudes, beliefs and behavioural intention with regard to both behaviours. The Theory of Planned Behaviour has assisted in identifying how social pressures play an influential role in relation to males receiving the HPV vaccine. Attitudes presented as the most significant predictor of male’s intentions to use a condom correctly and consistently. Intention to perform both behaviours was identified as moderate to high. Conclusion: This study has contributed to the field of HPV research, as it is the first piece of research to explore preventative HPV behaviours i.e. receiving the HPV vaccine, and condom use, amongst young males, utilising the Theory of Planned Behaviour. A deeper understanding of young male’s attitudes, beliefs, and behavioural intention on this topic has been achieved. Additionally, a new robust research instrument has been constructed. Findings from this study will undoubtedly help in the implementation of the HPV vaccine in Ireland, as well as influence health promotion campaigns aimed at young males, addressing the topic of condom use.

Impurity exclusion and retention during crystallisation and recrystallisation - the phenacetin by ethylation of paracetamol process

Science Foundation Ireland (05/PICA/B802/EC07, 07/SRC/B1158 and 12/RC/227505); Irish Research Council (Enterprise Partnership Scheme (IRSCET-Clarochem-2010-02)); University College Cork (UCC 2013 Strategic Research Fund); Clarochem (Ireland) Ltd

Investigating the role of Fas (CD95) signalling in the modification of innate immune induced inflammation

Background/Aim: It has been demonstrated that a number of pathologies occur as a result of dysregulation of the immune system. Whilst classically associated with apoptosis, the Fas (CD95) signalling pathway plays a role in inflammation. Studies have demonstrated that Fas activation augments TLR4-mediated MyD88-dependent cytokine production. Studies have also shown that the Fas adapter protein FADD is required for RIG-I-induced IFNβ production. As a similar signalling pathway exists between RIG-I, TLR3 and the MyD88- independent of TLR4, we hypothesised that Fas activation may modulate both TLR3- and TLR4-induced cytokine production. Results: Fas activation reduced poly I:C-induced IFNβ, IL-8, IL-10 and TNFα production whilst augmenting poly I:C-, poly A:U- and Sendai virus-induced IP-10 production. TLR3-, RIG-I- and MDA5-induced IP-10 luciferase activation were inhibited by the Fas adapter protein FADD using overexpression studies. Poly I:C-induced phosphorylation of p-38 and JNK MAPK were reduced by Fas activation. Overexpression of FADD induced AP-1 luciferase activation. Point mutations in the AP-1 binding site enhanced poly I:C-induced IP- 10 production. LPS-induced IL-10, IL-12, IL-8 and TNFα production were enhanced by Fas activation, whilst reducing LPS-induced IFNβ production. Absence of FADD using FADD-/- MEFs resulted in impaired IFNβ production. Overexpression studies using FADD augmented TLR4-, MyD88- and TRIF-induced IFNβ luciferase activation. Overexpression studies also suggested that enhanced TLR4-induced IFNβ production was independent of NFκB activation. Conclusion: Viral-induced IP-10 production is augmented by Fas activation by reducing the phosphorylation of p-38 and JNK MAPKs, modulating AP-1 activation. The Fas adapterprotein FADD is required for TLR4-induced IFNβ production. Studies presented here demonstrate that the Fas signalling pathway can therefore modulate the immune response. Our data demonstrates that this modulatory effect is mediated by its adapter protein FADD, tailoring the immune response by acting as a molecular switch. This ensures the appropriate immune response is mounted, thus preventing an exacerbated immune response.

Na marbhnaí do Shéamas Óg Mac Coitir (1689-1720)

Go príomha, is tráchtas é seo a dhéanann staidéar ar ghné de litríocht iar-chlasaiceach na Gaeilge. Baineann sé go háirithe leis an sraith chaointe nó marbhnaí i bhfoirm véarsaíochta a cumadh do Shéamas Óg Mac Coitir (1689-1720), duine uasal Caitliceach ó Charraig Tuathail, Co. Chorcaí, nuair a ciontaíodh é in éigniú Elizabeth Squibb, bean de Chumann na gCarad; nuair a cuireadh pionós an bháis air; agus nuair a crochadh é i gCathair Chorcaí an 7 Bealtaine, 1720. Ó thaobh na staire de, scrúdaítear Clann Choitir mar shampla de theaghlach nár cheil a ndílseacht do chúis pholaitiúil na Stíobhartach agus a sheas an fód go cróga faoi mar a bhí a ngreim polaitiúil á dhaingniú ag an gCinsealacht Phrotastúnach ó dheireadh an 17ú haois amach. Tagraítear do sheicteachas na sochaí comhaimseartha agus don teannas idir an pobal Caitliceach agus an pobal Protastúnach ag an am. Déantar scagadh ar an véarsaíocht mar fhoinse luachmhar do dhearcadh míshásta an mhóraimh Chaitlicigh ar struchtúr polaitiúil chontae Chorcaí (agus na hÉireann) i dtosach an 18ú haois. Is feiniméan liteartha an dlús véarsaíochta seo a bhaineann go háirithe le traidisiún liteartha Chorcaí. Tá na dánta curtha in eagar agus aistriúchán go Béarla curtha ar fáil: is é seo croí an tráchtais. Tá an t-eagrán bunaithe ar scrúdú cuimsitheach ar thraidisiún na lsí; pléitear modheolaíocht na heagarthóireachta. Déantar iarracht ar na dánta a shuíomh sa traidisiún casta liteartha sa tráchtaireacht tosaigh; sa chuid eile den bhfearas scoláiriúil, scrúdaítear ceisteanna a bhaineann le cúrsaí teanga, foclóra, meadarachta agus stíle. Tá innéacsanna agus liosta foinsí le fáil i ndeireadh an tráchtais.

Langmuir-Blodgett assembly of colloidal crystals combined with controlled infiltration of conducting metal oxides

Colloidal photonic crystals (PhCs) possess a periodic dielectric structure which gives rise to a photonic band gap (PBG) and offer great potential in the ability to modify or control light at visible wavelengths. Although the refractive index contrast between the void or infill and the matrix material is paramount for photonics applications, integration into real optoelectronics devices will require a range of added functionalities such as conductivity. As such, colloidal PhCs can be used as templates to direct infiltration of other functional materials using a range of deposition strategies. The work in this thesis seeks to address two challenges; first to develop a reproducible strategy based on Langmuir-Blodgett (LB) deposition to assemble high quality colloidal PhCs based on silica with precise film thickness as most other assembly methods suffer from a lack of reproducibility thickness control. The second is to investigate the use of LBdeposited colloidal PhCs as templates for infiltration with conducting metal oxide materials using vapor phase deposition techniques. Part of this work describes the synthesis and assembly of colloidal silica spheres with different surface chemical functionalities at the air-water interface in preparation for LB deposition. Modification of surface funtionality conferred varying levels of hydrophobicity upon the particles. The behaviour of silica monolayer films at the air-water interface was characterised by Brewster Angle Microscopy and surface pressure isotherms with a view to optimising the parameters for LB deposition of multilayer colloidal PhC films. Optical characterisation of LB-fabricated colloidal PhCs indicated high quality photonic behaviour, exhibiting a pseudo PBG with a sharp Bragg diffraction peak in the visible region and reflectance intensities greater than 60%. Finally the atomic layer deposition (ALD) of nominally undoped ZnO and aluminium “doped” ZnO (Al-doped ZnO) inside the pores of a colloidal PhC assembled by the LB technique was carried out. ALD growth in this study was performed using trimethyl aluminium (TMA) and water as precursors for the alumina and diethyl zinc (DEZn) and water for the ZnO. The ZnO:Al films were grown in a laminate mode, where DEZn pulses were substituted for TMA pulses in the sequences with a Zn:Al ratio 19:1. The ALD growth of ZnO and ZnO:Al in colloidal PhCs was shown to be highly conformal, tuneable and reproducible whilst maintaining excellent photonic character. Furthermore, at high levels of infiltration the opal composite films demonstrated significant conductivity.

Development of block copolymer lithography for device structure fabrication

This thesis investigated well-ordered block copolymer (BCP) thin film characteristics and their use for nanoscale pattern formation using a series of polystyrene-block-polymethylmethacrylate (PS-b-PMMA), polystyrene-blockpolydimethylsiloxane (PS-b-PDMS) and polystyrene-block-poly(ethylene oxide) (PS-b-PEO) systems of various molecular weights. BCP thin films, which act as an ‘on-chip’ etch mask and material templates, are highly promising self-assembling process for future scalable nanolithography. Unlike conventional BCP processing methods, the work in this thesis demonstrates that well-ordered patterns can be achieved in a few seconds compared to several hours by use of a non-conventional microwave assisted technique. As a result, well-ordered BCP nanoscale structures can be developed in industry appropriate periods facilitating their incorporation into current technologies. An optimised and controlled plasma dry etch process was used for successful pattern transfer to the underlying silicon substrate. Long range ordered BCP templates were further modified by selective metal inclusion technique to form a hard mask template towards fabrication of high aspect ratio nanopillars and nanowires. The work described here is centred on how these templates might be used to generate function at substrate surfaces. Herein we describe a number of innovations which might allow their successful uptake in a number of applications.

The ecology of the Irish stoat

The Irish stoat, Mustela erminea hibernica (Thomas and Barrett-Hamilton), has been regarded as an intermediate between the British stoat and the weasel. In this study Irish stoats, mainly from road casualties, were collected and studied. A small number were also live-trapped and radio-tracked. Thus information was gathered on the stoat’s ecology, in particular its form (size and coat colours), reproduction, food habits, parasites, habitat utilisation mortality and predation. The Irish stoats studied were clearly not intermediate in size between British stoats and weasels. They showed considerable size overlap with British stoats, and marked size variation within Ireland. It is argued that size of stoats is determined by food supply early in life. The ventral coat pattern of Irish stoats is apparently unique in the Palaearctic, being similar to that of some stoats found on the west coast of North America. It is argued that this is an example of parallel evolution resulting from adaptation to similar climatic conditions. The stoats were reproductively active in spring and summer. Food consisted mainly of rabbits, but rats, birds, shrews mice and voles were also consumed. Mites were the most numerous ectoparasites, followed by lice, ticks and fleas. Damage by the parasitic nematode Skrjabingylus nasicola was found more frequently in female stoat skulls. Stoats were frequently found in a variety of habitats, both open and wooded. Some of the radio-tracked stoats climbed trees. Dens used were often rat holes. Only one home range, that of a breeding female, was considered to have been accurately measured. It was 22 ha. in size. Mortality is known to have been caused by road accidents and domestic carnivores. It is argued that predation by raptorial birds is important to stoat populations. Results of this study are compared with information available from elsewhere.

Counterstories: who counts as lesbian?

Coming out midlife is a profound and life‐changing experience—it is an experience of self‐shattering that entails the destabilisation of identity, and of family relationships. Entailing a displacement from social insider to outsider, it is a difficult, but also exhilarating, journey of self, and sexual, discovery. This thesis is an examination of the experiences of nine women who undertook that journey. This dissertation is very much a search for understanding—for understanding how one can be lesbian, and how one can not have known, following a lifetime of heterosexual identification—as well as a search for why those questions arise in the first place. I argue that the experience of coming out midlife exposes the fundamental ambiguity of sexuality; and has a significance that ranges beyond the particularity of the participants’ experiences and speaks to the limitations of the hegemonic sexual paradigm itself. Using the theoretical lens of three diverse conceptual approaches—the dynamic systems theory of sexual fluidity; liminality; and narrative identity—to illuminate their transition, I argue that the event of coming out midlife should be viewed not merely as an atypical experience, but rather we should ask what such events can tell us about women’s sexuality in particular, and the sexual paradigm more generally. I argue that women who come out midlife challenge those dominant discourses of sexuality that would entail that women who come out midlife were either in denial of their “true” sexuality throughout their adult lives; or that they are not really lesbian now. The experiences of the women I interviewed demonstrate the inadequacy of the sexual paradigm as a framework within which to understand and research the complexity of human sexuality; they also challenge hegemonic understandings of sexuality as innate and immutable. In this thesis, I explore that challenge.

Micro and nanostructured impedance sensors for biological and biomedical applications

This thesis work covered the fabrication and characterisation of impedance sensors for biological applications aiming in particular to the cytotoxicity monitoring of cultured cells exposed to different kind of chemical compounds and drugs and to the identification of different types of biological tissue (fat, muscles, nerves) using a sensor fabricated on the tip of a commercially available needle during peripheral nerve block procedures. Gold impedance electrodes have been successfully fabricated for impedance measurement on cells cultured on the electrode surface which was modified with the fabrication of gold nanopillars. These nanostructures have a height of 60nm or 100nm and they have highly ordered layout as they are fabricated through the e-beam technique. The fabrication of the threedimensional structures on the interdigitated electrodes was supposed to improve the sensitivity of the ECIS (electric cell-substrate impedance sensing) measurement while monitoring the cytotoxicity effects of two different drugs (Antrodia Camphorata extract and Nicotine) on three different cell lines (HeLa, A549 and BALBc 3T3) cultured on the impedance devices and change the morphology of the cells growing on the nanostructured electrodes. The fabrication of the nanostructures was achieved combining techniques like UV lithography, metal lift-off, evaporation and e-beam lithography techniques. The electrodes were packaged using a pressure sensitive, medical grade adhesive double-sided tape. The electrodes were then characterised with the aid of AFM and SEM imaging which confirmed the success of the fabrication processes showing the nanopillars fabricated with the right layout and dimensions figures. The introduction of nanopillars on the impedance electrodes, however, did not improve much the sensitivity of the assay with the exception of tests carried out with Nicotine. HeLa and A549 cells appeared to grow in a different way on the two surfaces, while no differences where noticed on the BALBc 3T3 cells. Impedance measurements obtained with the dead cells on the negative control electrodes or the test electrodes with the drugs can be compared to those done on the electrodes containing just media in the tested volume (as no cells are attached and cover the electrode surface). The impedance figures recorded using these electrodes were between 1.5kΩ and 2.5 kΩ, while the figures recorded on confluent cell layers range between 4kΩ and 5.5kΩ with peaks of almost 7 kΩ if there was more than one layer of cells growing on each other. There was then a very clear separation between the values of living cell compared to the dead ones which was almost 2.5 - 3kΩ. In this way it was very easy to determine whether the drugs affected the cells normal life cycle on not. However, little or no differences were noticed in the impedance analysis carried out on the two different kinds of electrodes using cultured cells. An increase of sensitivity was noticed only in a couple of experiments carried out on A549 cells growing on the nanostructured electrodes and exposed to different concentration of a solution containing Nicotine. More experiments to achieve a higher number of statistical evidences will be needed to prove these findings with an absolute confidence. The smart needle project aimed to reduce the limitations of the Electrical Nerve Stimulation (ENS) and the Ultra Sound Guided peripheral nerve block techniques giving the clinicians an additional tool for performing correctly the peripheral nerve block. Bioimpedance, as measured at the needle tip, provides additional information on needle tip location, thereby facilitating detection of intraneural needle placement. Using the needle as a precision instrument and guidance tool may provide additional information as to needle tip location and enhance safety in regional anaesthesia. In the time analysis, with the frequency fixed at 10kHz and the samples kept at 12°C, the approximate range for muscle bioimpedance was 203 – 616 Ω, the approximate bioimpedance range for fat was 5.02 - 17.8 kΩ and the approximate range for connective tissue was 790 Ω – 1.55 kΩ. While when the samples were heated at 37°C and measured again at 10kHz, the approximate bioimpedance range for muscle was 100-175Ω. The approximate bioimpedance range of fat was 627 Ω - 3.2 kΩ and the range for connective tissue was 221-540Ω. In the experiments done on the fresh slaughtered lamb carcass, replicating a scenario close to the real application, the impedance values recorded for fat were around 17 kΩ, for muscle and lean tissue around 1.3 kΩ while the nervous structures had an impedance value of 2.9 kΩ. With the data collected during this research, it was possible to conclude that measurements of bioimpedance at the needle tip location can give valuable information to the clinicians performing a peripheral nerve block procedure as the separation (in terms of impedance figures) was very marked between the different type of tissues. It is then feasible to use an impedance electrode fabricated on the needle tip to differentiate several tissues from the nerve tissue. Currently, several different methods are being studied to fabricate an impedance electrode on the surface of a commercially available needle used for the peripheral nerve block procedure.