69,809 research outputs found

    Metaphors of London fog, smoke and mist in Victorian and Edwardian Art and Literature

    Get PDF
    Julian Wolfreys has argued that after 1850 writers employed stock images of the city without allowing them to transform their texts. This thesis argues, on the contrary, that metaphorical uses of London fog were complex and subtle during the Victorian and Edwardian periods, at least until 1914. Fog represented, in particular, formlessness and the dissolution of boundaries. Examining the idea of fog in literature, verse, newspaper accounts and journal articles, as well as in the visual arts, as part of a common discourse about London and the state of its inhabitants, this thesis charts how the metaphorical appropriation of this idea changed over time. Four of Dickens's novels are used to track his use of fog as part of a discourse of the natural and unnatural in individual and society, identifying it with London in progressively more negative terms. Visual representations of fog by Constable, Turner, Whistler, Monet, Markino, O'Connor, Roberts and Wyllie and Coburn showed an increasing readiness to engage with this discourse. Social tensions in the city in the 1880s were articulated in art as well as in fiction. Authors like Hay and Barr showed the destruction of London by its fog because of its inhabitants' supposed degeneracy. As the social threat receded, apocalyptic scenarios gave way to a more optimistic view in the work of Owen and others. Henry James used fog as a metaphorical representation of the boundaries of gendered behaviour in public, and the problems faced by women who crossed them. The dissertation also examines fog and individual transgression, in novels and short stories by Lowndes, Stevenson, Conan Doyle and Joseph Conrad. After 1914, fog was no more than a crude signifier of Victorian London in literature, film and, later, television, deployed as a cliche instead of the subtle metaphorical idea discussed in this thesis

    Desarrollo de materiales bioactivos con potencial aplicaci贸n odontol贸gica mediante impregnaci贸n asistida por CO2 supercr铆tico

    Get PDF
    Tesis (DCI)--FCEFN-UNC, 2021En esta tesis se estudi贸 el proceso de incorporaci贸n de eugenol en fibras de poliamida 6 (PA6) mediante la impregnaci贸n asistida por CO2 supercr铆tico para desarrollar un material con propiedades antimicrobianas con una potencial aplicaci贸n odontol贸gica. Para este prop贸sito, se construy贸 un equipo de alta presi贸n en el que se llevaron a cabo m煤ltiples ensayos de impregnaci贸n de eugenol y de sorci贸n de CO2 en un hilo dental comercial de PA6 en distintas condiciones de presi贸n y temperatura (40 鈥 60 掳C y 8 鈥 12 MPa). Con el fin de encontrar las mejores condiciones del proceso de impregnaci贸n, se evalu贸 la influencia de diferentes variables operativas (presi贸n, temperatura, tiempo de contacto y velocidad de despresurizaci贸n) sobre la cantidad de eugenol impregnada en el material. Adem谩s, se estudiaron los principales fen贸menos difusivos que ocurren en el proceso de impregnaci贸n del eugenol en condiciones supercr铆ticas. Para ello, se hicieron ensayos de cin茅tica de sorci贸n del CO2 y del eugenol en PA6 a diferentes condiciones de presi贸n y temperatura y se determin贸 el coeficiente de difusi贸n aparente para ambas especies en este pol铆mero. Por otra parte, se evaluaron las propiedades finales del material impregnado, analizando las propiedades mec谩nicas, t茅rmicas y morfol贸gicas del material original, presurizado con CO2 e impregnado con eugenol. Adicionalmente se evalu贸 la actividad antimicrobiana del material impregnado frente a dos bacterias comunes (Escherichia coli y Staphylococcus aureus). Asimismo, se estudi贸 la migraci贸n del compuesto activo impregnado en aire y en saliva artificial, obteniendo datos importantes para el potencial desarrollo de un producto comercial, como la estimaci贸n de la vida 煤til, el tipo de envase, y tipo de aplicaci贸n del producto. Finalmente, se hizo un dise帽o y dimensionamiento de un proceso industrial para la impregnaci贸n de eugenol en bobinas de fibras de PA6 en CO2 supercr铆tico, a partir de los datos de eficiencia de impregnaci贸n y par谩metros difusivos del hilo impregnado con eugenol previamente obtenidos, realizando el dise帽o de la bobina, el equipo impregnador y los c谩lculos de sus principales requerimientos de masa y energ铆a.Fil: Mosquera Ruiz, Jos茅 Euliser. Universidad Nacional de C贸rdoba. Facultad de Ciencias Exactas, F铆sicas y Naturales; Argentina.Fil: Mosquera Ruiz, Jos茅 Euliser. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Instituto de Investigaci贸n y Desarrollo en Ingenier铆a de Procesos y Qu铆mica Aplicada; Argentina

    CFD Combustion Simulations and Experiments on the Blended Biodiesel Two-Phase Engine Flows

    Get PDF
    Biodiesels are the promising sources of alternative energy. Combustion phenomenon of blended biodiesels differs to those of diesel due to changes in physio-chemical properties. Experimental investigations are costly and time-consuming process, whereas mathematical modeling of the reactive flows is involved. This chapter deals with combustion simulations on four-stroke single-cylinder direct injection compression ignition engine running at a constant speed of 1500聽rpm, injection timing of 25掳 BTDC with diesel and 20% blend of Jatropha biodiesel. Standard finite volume method of computational fluid dynamics (CFD) is capable of simulating two-phase engine flows by solving three-dimensional Navier鈥揝tokes equations with k-蔚 turbulence model. Combustion simulations have been carried out for half-cycle by considering the two strokes compression and expansion at zero load condition. The model mesh consists of 557,558 elements with 526,808 nodes. Fuel injection begins at 725掳 and continues till 748掳 of the crank angle. Charge motion within the cylinder, turbulent kinetic energy, peak pressure, penetration length, and apparent heat release rate are analyzed with respect to the crank angle for diesel and its B-20 Jatropha blend. Experimental data supports the simulation results. B-20 Jatropha blend possesses similar characteristics of diesel and serves as an alternative to diesel

    The Cerebral Plasticity Prospect of Stingless Bee Honey-Polyphenols Supplementation in Rehabilitation of Post-Stroke Vascular Cognitive Impairment

    Get PDF
    The neuroprotective potential of stingless bee honey (SBH) is still to be documented from numerous studies including that of its effect on cerebrovascular event. This review should guide stroke rehabilitation specialties to a high understanding of the overall circuit changes post-stroke, the clinical relevance of this change in stroke to cognitive impairment and dementia, and SBH as a supplementation in modern stroke rehabilitation in progresses. However, the potential of SBH as a supplementation therapy and highlights treatment to induced plasticity for post-stroke vascular cognitive impairment (PSVCI) remains largely unexplored. This Chapter attempts to deliberate on recent evidence that highlight the therapeutic properties of honey and SBH, the features of PSVCI, and proposing the plausible mechanism of action for SBH as a supplementation during stroke rehabilitation that could halt the progression of PSVCI. It is hoped that such an approach could complement the existing evidence-based stroke care, and which will help in the development of future direction of brain plasticity to delay the progression of cognitive impairment post-stroke

    Identification of Hindbrain Neural Substrates for Motor Initiation in the hatchling Xenopus laevis Tadpole

    Get PDF
    Animal survival profoundly depends on the ability to detect stimuli in the environment, process them and respond accordingly. In this respect, motor responses to a sensory stimulation evolved into a variety of coordinated movements, which involve the control of brain centres over spinal locomotor circuits. The hatchling Xenopus tadpole, even in its embryonic stage, is able to detect external sensory information and to swim away if the stimulus is considered noxious. To do so, the tadpole relies on well-known ascending sensory pathway, which carries the sensory information to the brain. When the stimulus is strong enough, descending interneurons are activated, leading to the excitation of spinal CPG neurons, which causes the undulatory movement of swimming. However, the activation of descending interneurons that marks the initiation of motor response appears after a long delay from the sensory stimulation. Furthermore, the long-latency response is variable in time, as observed in the slow-summating excitation measured in descending interneurons. These two features, i.e. long-latency and variability, cannot be explained by the firing time and pattern of the ascending sensory pathway of the Xenopus tadpole. Therefore, a novel neuronal population has been proposed to lie in the hindbrain of the tadpole, and being able to 'hold' the sensory information, thus accounting for the long and variable delay of swim initiation. In this work, the role of the hindbrain in the maintenance of the long and variable response to trunk skin stimulation is investigated in the Xenopustadpole at developmental stage 37/38. A multifaceted approach has been used to unravel the neuronal mechanisms underlying the delayed motor response, including behavioural experiments, electrophysiology analysis of fictive swimming, hindbrain extracellular recordings and imaging experiments. Two novel neuronal populations have been identified in the tadpole's hindbrain, which exhibit activation patterns compatible with the role of delaying the excitation of the spinal locomotor circuit. Future work on cellular properties and synaptic connections of these newly discovered populations might shed light on the mechanism of descending control active at embryonic stage. Identifying supraspinal neuronal populations in an embryonic organism could aid in understanding mechanisms of descending motor control in more complex vertebrates

    Bioinformatic characterization of a triacylglycerol lipase produced by Aspergillus flavus isolated from the decaying seed of Cucumeropsis mannii

    Get PDF
    Lipases are enzymes of industrial importance responsible for the hydrolysis of ester bonds of triglycerides. A lipolytic fungus was isolated and subsequently identified based on the ITS sequence analysis as putative Aspergillus flavus with accession number LC424503. The gene coding for extracellular triacylglycerol lipase was isolated from Aspergillus flavus species, sequenced, and characterised using bioinformatics tools. An open reading frame of 420 amino acid sequence was obtained and designated as Aspergillus flavus lipase (AFL) sequence. Alignment of the amino acid sequence with other lipases revealed the presence GHSLG sequence which is the lipase consensus sequence Gly-X1-Ser-X2-Gly indicating that it a classical lipase. A catalytic active site lid domain composed of TYITDTIIDLS amino acids sequence was also revealed. This lid protects the active site, control the catalytic activity and substrate selectivity in lipases. The 3-Dimensional structural model shared 34.08% sequence identity with a lipase from Yarrowia lipolytica covering 272 amino acid residues of the template model. A search of the lipase engineering database using AFL sequence revealed that it belongs to the class GX-lipase, superfamily abH23 and homologous family abH23.02, molecular weight and isoelectric point values of 46.95鈥塊Da and 5.7, respectively. N-glycosylation sites were predicted at residues 164, 236 and 333, with potentials of 0.7250, 0.7037 and 0.7048, respectively. O-glycosylation sites were predicted at residues 355, 358, 360 and 366. A signal sequence of 37 amino acids was revealed at the N-terminal of the polypeptide. This is a short peptide sequence that marks a protein for transport across the cell membrane and indicates that AFL is an extracellular lipase. The findings on the structural and molecular properties of Aspergillus flavus lipase in this work will be crucial in future studies aiming at engineering the enzyme for biotechnology applications

    The JCMT BISTRO Survey: Multi-wavelength polarimetry of bright regions in NGC 2071 in the far-infrared/submillimetre range, with POL-2 and HAWC+

    Get PDF
    Polarized dust emission is a key tracer in the study of interstellar medium and of star formation. The observed polarization, however, is a product of magnetic field structure, dust grain properties and grain alignment efficiency, as well as their variations in the line of sight, making it difficult to interpret polarization unambiguously. The comparison of polarimetry at multiple wavelengths is a possible way of mitigating this problem. We use data from HAWC+/SOFIA and from SCUBA-2/POL-2 (from the BISTRO survey) to analyse the NGC 2071 molecular cloud at 154, 214 and 850 渭m. The polarization angle changes significantly with wavelength over part of NGC 2071, suggesting a change in magnetic field morphology on the line of sight as each wavelength best traces different dust populations. Other possible explanations are the existence of more than one polarization mechanism in the cloud or scattering from very large grains. The observed change of polarization fraction with wavelength, and the 214-to-154 渭m polarization ratio in particular, are difficult to reproduce with current dust models under the assumption of uniform alignment efficiency. We also show that the standard procedure of using monochromatic intensity as a proxy for column density may produce spurious results at HAWC+ wavelengths. Using both long-wavelength (POL-2, 850 渭m) and short-wavelength (HAWC+, 鈮200渭m) polarimetry is key in obtaining these results. This study clearly shows the importance of multi-wavelength polarimetry at submillimeter bands to understand the dust properties of molecular clouds and the relationship between magnetic field and star formation

    Uso de las histonas circulantes y sus modificaciones post-traduccionales como biomarcadores en sepsis y shock s茅ptico

    Get PDF
    La sepsis es una afecci贸n potencialmente mortal causada por una respuesta anormal del hu茅sped a una infecci贸n, produciendo respuestas fisiol贸gicas alteradas que da帽an los propios tejidos del paciente y pueden provocar disfunci贸n org谩nica e incluso la muerte. Asimismo, algunos pacientes s茅pticos progresan a shock s茅ptico, caracterizado por alteraciones circulatorias, celulares y metab贸licas sustanciales que aumentan el riesgo de mortalidad. A pesar de que la sepsis se caracteriza por un mal funcionamiento del sistema inmunol贸gico, lo que a su vez conduce a una respuesta inmune alterada e inmunosupresi贸n, la alta complejidad de la fisiopatolog铆a de la sepsis requiere una mayor investigaci贸n para comprender las respuestas inmunes que ocurren durante la sepsis. Asimismo, las histonas extracelulares circulantes han ganado relevancia como mediadores citot贸xicos en la sepsis, ya que act煤an como patrones moleculares asociados a da帽o, que inducen estr茅s oxidativo y activan el inflamasoma NLRP3. Estos mecanismos median la activaci贸n de la piroptosis, un mecanismo de muerte celular programada que produce inflamaci贸n mediante la expresi贸n de IL-18, IL-1尾 and IL-1伪. Sin embargo, a pesar de la evidencia de activaci贸n del inflamasoma en las c茅lulas inmunes durante la sepsis, se desconoce si las histonas extracelulares son capaces de activar los inflamasomas endoteliales y sus consecuencias. En este trabajo destacamos el papel previamente desconocido de las histonas extracelulares, mediando la activaci贸n del inflamasoma NLRP3 y la piroptosis en las c茅lulas endoteliales, contribuyendo a la disfunci贸n endotelial y la desregulaci贸n de la respuesta inmune mediada por el endotelio. Asimismo, tambi茅n demostramos c贸mo la acetilaci贸n de histonas disminuye la activaci贸n de la piroptosis. Adem谩s, demostramos que la piroptosis se produce en pacientes con shock s茅ptico y los niveles de histonas circulantes se correlacionan con la expresi贸n de citoquinas proinflamatorias y citoquinas piropt贸ticas, la liberaci贸n de factores de adhesi贸n endotelial y la gravedad de la enfermedad. Proponemos la piroptosis mediada por histonas como un nuevo objetivo para desarrollar intervenciones cl铆nicas. De manera similar, hemos analizado las respuestas inmunorelacionadas que ocurren durante las primeras etapas de la sepsis con el objetivo de proporcionar nuevos datos comparando las cantidades de citoquinas, inmunomoduladores y otros mediadores endoteliales en pacientes cr铆ticamente enfermos no s茅pticos, s茅pticos y de shock s茅ptico. Nuestro enfoque ayudar谩 a caracterizar r谩pidamente las respuestas inmunes alteradas en pacientes s茅pticos y de shock s茅ptico ingresados en la Unidad de Cuidados Intensivos. Finalmente analizamos el papel de la metilaci贸n del ADN en el control del sistema inmune s茅ptico. Nuestros resultados demostraron el papel central de la metilaci贸n del ADN modulando la respuesta molecular en los pacientes de shock s茅ptico y contribuyendo a la inmunosupresi贸n, a trav茅s de la alteraci贸n de los patrones de metilaci贸n de los promotores de IL-10 y TREM-2.Sepsis is a life-threatening condition caused by an abnormal host response to an infection that produce altered physiological responses which damages own tissues of the patient and can result in organ dysfunction and in some cases death. Likewise, a subset of septic patients progresses to septic shock, characterized by substantial circulatory, cellular and metabolic abnormalities, which substantially increase the risk of mortality. Sepsis is characterized by a malfunction of the immune system and it can lead to an altered immune response and immunosuppression. Moreover, the high complexity of the pathophysiology of sepsis requires of further investigation to characterize the immune responses in sepsis and septic shock. Likewise, circulating extracellular histones have gained relevance as cytotoxic mediators in sepsis pathophysiology, since they act as damage-associated molecular patterns, which induce oxidative stress and activate NLRP3 inflammasome. Subsequently, inflammasome mediates pyroptosis activation, a programmed cell death mechanism that produces inflammation through the release of IL-18, IL-1尾 and IL-1伪. However, despite inflammasome activation may occur in immune cells during sepsis, it is unknown if this process also takes place in endothelial cells and particularly whether extracellular histones are capable of activating endothelial inflammasomes and their consequences. In this work we highlight a previously unknown role for extracellular histones, that mediates the activation of NLRP3 inflammasome and pyroptosis in endothelial cells by contributing to endothelial dysfunction and the dysregulation of the immune response mediated by endothelium. Likewise, we demonstrated how histone acetylation decreases pyroptosis activation. Furthermore, we show how pyroptosis occurs in septic shock patients and how circulating histone levels correlate with the expression of pro-inflammatory and pyroptotic cytokines, the release of endothelial adhesion factors and septic shock severity. We propose histone-mediated pyroptosis as a new target to develop clinical interventions. Similarly, we have analyzed the immune-related responses occurring during the early stages of sepsis with the aim of providing new data by comparing the amounts of cytokines, immune modulators and other endothelial mediators in critically-ill non-septic patients, septic and septic shock patients. Our approach will help to rapidly characterize the altered immune responses in septic and septic shock patients admitted in the Intensive Care Unit. Finally, we also analyzed the role of DNA methylation in the control of septic immune system. Our results demonstrated the central role of DNA methylation modulating the molecular response in septic shock patients and contributing to immunosuppression, through the alteration of DNA methylation patterns of IL-10 and TREM2 promoters
    corecore