15 research outputs found
Present-day and future lightning, and its impact on tropospheric chemistry
No full textLightning represents a key interaction with climate through its production of
nitrogen oxides (NOx) which lead to ozone production. These NOx emissions are
generally calculated interactively in chemistry-climate models but there has been
little development of the representation of the lightning processes since the 1990s.
In most models the parametrisation of lightning is based upon simulated cloud-top
height. The aims of the thesis are: to explore existing schemes, and develop
a new process-based scheme, to parametrise lightning; to use a new process-based
lightning scheme to give insights regarding the role of lightning NOx in
tropospheric chemistry; and to use alternative lightning schemes to improve the
understanding of the response of lightning to climate change, and the consequent
impacts on tropospheric chemistry.
First, a new lightning parametrisation is developed using reanalysis data and
satellite lightning observations which is based on upward cloud ice flux. This
parametrisation is more closely linked to thunderstorm charging theory. It greatly
improves the simulated zonal distribution of lightning compared to the cloud-top
height approach, which overestimates lightning in the tropics. The new lightning
scheme is then implemented in a chemistry-climate model, the UK Chemistry
and Aerosol model (UKCA). It is evaluated against ozone sonde measurements
with broad global coverage and improves the simulation of the annual cycle of
upper tropospheric ozone concentration, compared to ozone simulated with the
cloud-top height approach. This improvement in simulated ozone is attributed to
the change in ozone production associated with the improved zonal distribution
of simulated lightning.
Subsequently, data from a chemistry-climate model intercomparison project (ACCMIP)
are used to study the state-of-the-art in lightning NOx parametrisation
along with its response to climate change. It is found that the models using the
cloud-top height approach produce a very similar response of lightning NOx to
changes in global mean surface temperature of +0.44± 0.05 TgNK-1, for a baseline
emission of 5 TgN yr-1. However, two models using two alternative lightning
schemes produce a weaker and a negative response of lightning to climate change.
Finally, simulations in a future climate scenario for year 2100 in the UKCA model
were performed with the cloud-top height and the ice flux parametrisations. The
lightning response to climate change when using the cloud-top height scheme is
in good agreement with the positive response found in the multi-model results
of the cloud-top height approach. However, the new ice flux approach suggests
that lightning will decrease in future. These opposing responses introduce large
uncertainty into the projections of tropospheric ozone and methane lifetime in the
future scenario. An analysis of the radiative forcing from these two species also
shows the large uncertainty in the individual methane and ozone radiative forcings
in the future. Due to the opposite effect that lightning NOx has on methane (loss)
and ozone (production) the net radiative forcing effect of lightning in present-day
and future is found to be close to zero. However, there is a small positive feedback
suggested by the results of the cloud-top height approach, whereas no feedback is
evident with the ice flux approach.
These results show there are large and crucial uncertainties introduced by
lightning parametrisation choice, not only in terms of the actual lightning
distribution but also atmospheric composition and radiative forcing. The new
ice-based parametrisation developed here offers a good alternative to the widely-used
approach and can be used in future to model lightning and develop the
understanding of associated uncertainties
Memory Ireland. : 4. James Joyce and cultural memory /
No full textIn the fourth and final volume of the Memory Ireland series, Frawley and O'Callaghan explore the manifestations and values of cultural memory in Joyce's Ireland, both real and imagined. An exemplary author to consider in relation to questions of how it is that history is remembered and recycled, Joyce creates characters that confront particularly the fraught relationship between the individual and the historical past; the crisis of colonial history in relation to the colonized state; and the relationship between the individual's memory of his or her own past and the past of the broader culture. The collection includes leading Joyce scholars including Luke Gibbons, Vincent Cheng, and Declan Kiberd and considers such topics as Jewish memory in Ulysses, history and memory in Finnegans Wake, and Joyce and the Bible.Includes bibliographical references (pages 205-220) and index.In the fourth and final volume of the Memory Ireland series, Frawley and O'Callaghan explore the manifestations and values of cultural memory in Joyce's Ireland, both real and imagined. An exemplary author to consider in relation to questions of how it is that history is remembered and recycled, Joyce creates characters that confront particularly the fraught relationship between the individual and the historical past; the crisis of colonial history in relation to the colonized state; and the relationship between the individual's memory of his or her own past and the past of the broader culture. The collection includes leading Joyce scholars including Luke Gibbons, Vincent Cheng, and Declan Kiberd and considers such topics as Jewish memory in Ulysses, history and memory in Finnegans Wake, and Joyce and the Bible
Development of polymeric biodegradable materials with optimised mechanical properties for the freeforming plastic deposition of ureteral stents
No full textMais de 1,5 milhão de stents ureterais são implantados globalmente a cada ano, entretanto, mais de 80% falham devido a complicações como refluxo ureterovesical, irritação tecidual e formação de biofilme cristalino infeccioso. Essas falhas resultam em dor e desconforto significativos para os pacientes, frequentemente exigindo reintervenções cirúrgicas, o que reduz ainda mais a qualidade de vida dos pacientes e aumenta os custos dos serviços de saúde. Embora a maioria dos stents comerciais seja fabricada a partir de polímeros não biodegradáveis (por exemplo, silicone ou poliuretano), períodos prolongados de permanência (superiores a quatro semanas) intensificam os riscos de incrustação mediada por biofilme, influenciada por fatores como o material do stent, comorbidades do paciente e composição da urina. Há uma necessidade crítica de desenvolver materiais biodegradáveis que mantenham o desempenho funcional durante o tratamento e se degradem de forma segura posteriormente, evitando assim procedimentos de remoção secundária e reduzindo complicações associadas ao biofilme.
Para enfrentar essas limitações, esta pesquisa teve como objetivo projetar, fabricar e caracterizar um novo stent urinário biodegradável utilizando misturas de ácido polilático (PLA), polihidroxibutirato (PHB) e policaprolactona (PCL), modificadas com aditivos funcionais para melhorar o desempenho. Os aditivos investigados incluíram nanotubos de haloisita para reforço mecânico, nanopartículas de ZnO/Ag e SiO2/Ag pelas suas propriedades antimicrobianas, além de polietilenoglicol (PEG) e óleo de soja epoxidado (ESO) para efeito compatibilizante. Esses aditivos foram incorporados para aprimorar a miscibilidade das misturas, a eficácia antimicrobiana e a citocompatibilidade. A extrusão por fusão a quente (HME) foi empregada para processar as misturas, priorizando testes mecânicos voltados para a flexibilidade do material, uma propriedade crítica para a funcionalidade dos stents ureterais. Embora muitas formulações tenham apresentado desempenho mecânico insuficiente ou citotoxicidade, as formulações otimizadas que demonstraram maior flexibilidade foram selecionadas para desenvolvimento adicional. Essas formulações foram processadas via Arburg Plastic Freeforming (APF), uma tecnologia de impressão 3D de alta precisão que exigiu otimização meticulosa de parâmetros (temperatura da rosca e do bico, altura da camada, razão de aspecto das gotas, ângulo de deposição, taxa de descarga, entre outros) para garantir a precisão dimensional e a integridade estrutural das peças impressas. Por meio da APF, um novo design de stent foi prototipado, divergindo do tradicional stent duplo J introduzido por Finney em 1978, que ainda apresenta limitações como desconforto ao paciente devido à rigidez e ao ajuste anatômico inadequado. Estudos de degradação in vitro demonstraram que o novo stent se biodegrada dentro de seis a oito semanas em urina artificial, alinhando-se aos períodos clínicos relevantes de permanência. Durante as oito semanas, os stents biodegradáveis apresentaram degradação controlada, com redução significativa da incrustação em comparação com os stents comerciais, que exibiram incrustação completa já na quarta semana. A caracterização analítica por microscopia eletrônica de varredura (MEV) e espectroscopia de emissão óptica com plasma acoplado indutivamente (ICP-OES) confirmou que os depósitos de incrustação nos stents comerciais continham fosfato de cálcio, oxalato e estruvita. Em contrapartida, os stents biodegradáveis mantiveram alta viabilidade celular e biocompatibilidade, abordando diretamente as principais limitações dos modelos existentes. Testes comparativos contra stents comerciais de poliuretano demonstraram redução significativa na formação de biofilme e incrustação, validando seu potencial para mitigar complicações inerentes aos modelos atuais.
Este estudo avança no desenvolvimento de stents ureterais biodegradáveis ao integrar materiais biodegradáveis avançados, manufatura aditiva para prototipagem rápida e um design centrado no paciente. Ao abordar as limitações dos stents duplo J atuais, como desconforto e recorrência de complicações, esta pesquisa estabelece as bases para avanços na área de desenvolvimento de stents ureterais, com o objetivo final de melhorar a qualidade de vida dos pacientes. [resumo fornecido pelo autor]Over 1.5 million ureteral stents are implanted globally each year, yet more than 80% are reported to fail due to complications such as ureterovesical reflux, tissue irritation, and infectious crystalline biofilm formation. These failures result in significant patient pain and discomfort, frequently necessitating surgical re-intervention, which further lessens patients' quality of life and escalates healthcare costs. While most commercial stents are fabricated from non-biodegradable polymers (e.g., silicone or polyurethane), prolonged indwelling periods (over four weeks) exacerbate risks of biofilm-mediated encrustation, influenced by factors such as stent material, patient comorbidities, and urine composition. There is a critical need for the development of biodegradable materials that maintain functional performance during treatment while biodegrading safely afterward, thereby avoiding secondary removal procedures and reducing biofilm-associated complications. To address these limitations, this research aimed to design, construct, and characterise a novel biodegradable ureteral stent using blends of polylactic acid (PLA), polyhydroxybutyrate (PHB), and polycaprolactone (PCL), modified with functional additives to enhance performance. Investigated additives included halloysite nanotubes for mechanical reinforcement, ZnO/Ag and SiO2/Ag nanoparticles for their antimicrobial properties, and polyethylene glycol (PEG) and epoxidised soybean oil (ESO) for their compatibilising effect. These were incorporated to improve blend miscibility, antimicrobial efficacy, and cytocompatibility. Hot melt extrusion (HME) was employed to process the blends, with mechanical testing prioritising material flexibility, a critical property for ureteral stent functionality. While many blends exhibited insufficient mechanical performance or cytotoxicity, optimised formulations achieving higher flexibility were selected for further development. These were processed via Arburg Plastic Freeforming (APF), a high-precision 3D printing technology requiring methodical parameter optimisation (screw and nozzle temperature, layer height, drop aspect ratio, deposition angle, discharge rate, etc.) to ensure dimensional accuracy and structural integrity in printed parts. Using APF, a novel stent design was prototyped, departing from the conventional double J stent design introduced in 1978 by Finney, which remains prone to patient discomfort due to rigidity and poor anatomical fit. In vitro degradation studies demonstrated that the novel stent biodegrades within six to eight weeks in artificial urine, aligning with clinically relevant indwelling periods. Over the eight-week period, the biodegradable stents demonstrated controlled degradation, with significantly reduced encrustation compared to commercial stents, which exhibited complete encrustation by week four. Analytical characterisation using scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) confirmed that encrustation deposits on commercial stents presented calcium phosphate, oxalate, and struvite. In contrast, the biodegradable stents maintained high cell viability and biocompatibility, directly addressing key limitations of existing models. Comparative testing against commercial polyurethane stents showed significantly reduced biofilm formation and encrustation, validating its potential to mitigate complications inherent to current models. This research study advances the development of biodegradable ureteral stents by integrating advanced biodegradable materials, additive manufacturing for fast prototyping, and patient-centric design. By addressing the limitations of current double J stents, such as patient discomfort and recurrent complications, this research lays the groundwork for advancements in the field of ureteral stents development, with the ultimate purpose of enhancing patient's quality of life. [resumo fornecido pelo autor
An archaeology of Irish cinema: Ireland's subaltern, migrant and feminist film cultures (1973-87)
No full textThis thesis examines the development of an Irish film avant-garde, from the mid 1970s to the late 1980s. The thesis argues that this period was marked by an historically specific intersection between Irish and international film cultures, which can be traced through contemporary film theory, cultural policy and critical practice. This period witnessed a revitalisation of indigenous production, and new initiatives in Irish arts policy, but many important Irish filmmakers trained or began their careers in London and New York, while others were supported by cultural and political agencies outside the state. The thesis focuses on the work of five filmmakers (Bob Quinn, Joe Comerford, Thaddeus O’Sullivan, Vivienne Dick and Pat Murphy) and on three key areas of intersection between Irish and international film culture, associated with the ‘subaltern’, migration and feminism. Through close readings of specific films, supported by interviews with selected filmmakers, distributors and archivists, the thesis develops an expanded model of practice, which extends beyond production to address issues of distribution and exhibition. This archaeology of Irish cinema is informed by post-structural critiques of the archive, as well as theories of the avantgarde, and it argues that the reception of Irish avant-garde film has been structured by the institutional discourses of the museum and the academy
Author Correction: Comprehensive analysis of chromothripsis in 2,658 human cancers using whole-genome sequencing
No full textauthor correctio
Music in words : the music of Anthony Burgess, and the role of music in his literature
No full textTheý principal focus of the thesis is Anthony Burgess, a prolific novelist whose first and
enduring creative passion was music in general and composition in particular. Burgess
criticism is limited and largely out-of-date, showing little recognition of the aural or musical
elements in his fiction, and virtually no specialist commentary on the music and its
relationships with the literature. The main aim of the thesis, therefore, is to demonstrate the
variety and strength of the widespread musical elements in Burgess's literature, including the
importance he attaches to the sonic basis of language, and to show that these are supported by
the musical sensibility and technical competence evident in his. compositions. It is suggested
that in the inevitable reassessmenot f his work following his death in 1993, the effects of his
musicianship on his literary work should play a greater part than hitherto, and the thesis makes
a contribution to this reassessmenbt oth through its original critical commentaries on his music
and through the music-orientated discussion of his literature.
After an introduction and literature review, the first chapter examines three examples of
Burgess's little-known music. All are associated with verbal texts, though the range is
otherwise wide, and through them it is possible to draw conclusions about the competence of
his handling of musical language and structure. The second and third chapters examine the
more familiar work of Burgess the acclaimed author, but from the unfamiliar viewpoint of its
musical content, including not only surface references but also hidden allusions and technical
puzzles aimed at the musician reader. Two instances of music serving as a structural template
for literature are analysed in detail, and attention is also drawn to Burgess's awareness of
musical elements in the content and language of the, work of some. of his predecessors. The
final core-chapter,e xamines the fusion of Burgess's literary and,m usical skills in the context of
his music and words for stage and radio.
What emerges is the clear intermeshing of his parallel careers;, and the production within his
distinctive literary output of work which, due to the radical extent of its musicalisation, has to
be viewed as musically-aware literature for specialised readers, at times evincing, it is
proposed, a logic which springs primarily from music
Author Correction: Pan-cancer analysis of whole genomes
No full textCell adhesion molecules are ubiquitous in multicellular organisms, specifying precise cell-cell interactions in processes as diverse as tissue development, immune cell trafficking and the wiring of the nervous system(1-4). Here we show that a wide array of synthetic cell adhesion molecules can be generated by combining orthogonal extracellular interactions with intracellular domains from native adhesion molecules, such as cadherins and integrins. The resulting molecules yield customized cell-cell interactions with adhesion properties that are similar to native interactions. The identity of the intracellular domain of the synthetic cell adhesion molecules specifies interface morphology and mechanics, whereas diverse homotypic or heterotypic extracellular interaction domains independently specify the connectivity between cells. This toolkit of orthogonal adhesion molecules enables the rationally programmed assembly of multicellular architectures, as well as systematic remodelling of native tissues. The modularity of synthetic cell adhesion molecules provides fundamental insights into how distinct classes of cell-cell interfaces may have evolved. Overall, these tools offer powerful abilities for cell and tissue engineering and for systematically studying multicellular organization. Synthetic cell adhesion molecules yield customized cell-cell interactions with adhesion properties that are similar to native interactions, and offer abilities for cell and tissue engineering and for systematically studying multicellular organization
Author Correction: Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
No full text: Correction to this paper has been published: https://doi.org/10.1038/s41467-020-20128-w
A multimodal neural signature of face processing in autism within the fusiform gyrus
No full textInternational audienceAtypical face processing is commonly reported in autism. Its neural correlates have been explored extensively across single neuroimaging modalities within key regions of the face processing network, such as the fusiform gyrus (FFG). Nonetheless, it is poorly understood how variation in brain anatomy and function jointly impacts face processing and social functioning. Here we leveraged a large multimodal sample to study the cross-modal signature of face processing within the FFG across four imaging modalities (structural magnetic resonance imaging (MRI), resting-state functional magnetic resonance imaging, task-functional magnetic resonance imaging and electroencephalography) in 204 autistic and nonautistic individuals aged 7-30 years (case-control design). We combined two methodological innovations-normative modeling and linked independent component analysis-to integrate individual-level deviations across modalities and assessed how multimodal components differentiated groups and informed social functioning in autism. Groups differed significantly in a multimodal component driven by bilateral resting-state functional MRI, bilateral structure, right task-functional MRI and left electroencephalography loadings in face-selective and retinotopic FFG. Multimodal components outperformed unimodal ones in differentiating groups. In autistic individuals, multimodal components were associated with cognitive and clinical features linked to social, but not nonsocial, functioning. These findings underscore the importance of elucidating multimodal neural associations of social functioning in autism, offering potential for the identification of mechanistic and prognostic biomarkers
