59 research outputs found
“All the difference between the sketch and the finished work”: Percorsi Genetici e Ricerca dell’Identità nei Romanzi di Virginia Woolf.
No full textThis thesis focuses on an analysis of some recurrent themes in the work of Virginia Woolf, in the perspective of Gender Studies, Biographical Studies and Genetic Studies. It deals with some of Woolf's major novels and it also presents a comparative analysis of her masterpiece "Mrs Dalloway" and of its manuscript, "The Hours", presently kept at the British Museum's Manuscript section.La tesi si occupa dell’indagine di alcune tematiche ricorrenti nell’opera di Virginia Woolf, avvalendosi degli strumenti offerti dagli studi di genere, dalle indagini biografiche e dalla critica genetica. Nel corso dell’analisi si è fatto infatti ampio ricorso ai carteggi personali dell’autrice, ai diari e si è proceduto ad un’analisi comparatistica del manoscritto di Mrs Dalloway conservato al British Museum di Londra
“She parted the curtains; she looked”: finestre spalancate su realtà apparentemente inconciliabili in Mrs Dalloway di Virginia Woolf
No full textMrs Dalloway is probably the most multifaceted and complex novel by Virginia Woolf; this complexity derives from the writer’s desire to represent life seen both from the points of view of the insane and the sane: “the world seen by the sane and the insane side by side” (D2, 14 ottobre 1922, p. 207). The novel, thus, is structured on two main plots, whose protagonists are Mrs Dalloway on one side (representing the ‘sane truth’) and the veteran Septimus Warren-Smith on the other (representing the ‘insane truth’). During one single day, the stories of the protagonists develop without intersecting in the city of London. In such a complex design, the window becomes a strong symbol of communication and connection between these two worlds which only seem to be detached and independent. Not only that, but since the beginning of the novel the window symbolises also the passage from a time frame to another, from the present moment to a more or less distant past, thus permitting the author to linger on the past of the characters, revealing aspects of their personalities that, otherwise, would remain unknown. This essay then will present the symbology of the window in Virginia Woolf’s novel through the analysis of the most effective episodes of Mrs Dalloway, where this object becomes a mean of communication between apparently disconnected realities like sanity and madness, youth and adulthood, past and present and life and death
Dalla diversità al delitto: il lato oscuro di un’opera di Virginia Woolf
No full textVirginia Woolf is rarely associated with the noir genre. Nevertheless, the themes of crime and of social justice are widely present in her literary production. Particularly, the ideas of crime and of its equal punishment emerge almost obsessively in Mrs Dalloway, where the writer analysed and challenged, in a very modern perspective, the inability of the society of her time to deal with the otherness.
The novel, published in 1925, is structured on a double plot, in which Woolf skilfully juxtaposes a socially acceptable society – the summery, middle-class and “sane” London of Clarissa Dalloway – with a darker dimension – the post-war, visionary and “insane” London of Septimus Warren-Smith, a homosexual veteran suffering from shell-shock – where the marginalization of the individual eventually leads to crime. Such a dichotomy allowed Woolf to introduce in her novel themes that were considered taboo at the time, such as the notions of marginality – in this case related to mental illness and homosexuality – and crime.
This essay analyses the theme of crime in Mrs Dalloway focusing on the figure of Septimus Warren-Smith, in a comparative perspective and through the autobiographical resources of Woolf’s own diaries and letters
Formazione ed evoluzione dei proto-ammassi di galassie: una prospettiva sulla missione SPICA.
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Herschel-ATLAS : deep HST/WFC3 imaging of strongly lensed submillimetre galaxies
No full textThis work is supported by STFC (grants PP/D002400/1 and ST/G002533/1)We report on deep near-infrared observations obtained with the Wide Field Camera-3 (WFC3) onboard the Hubble Space Telescope (HST) of the first five confirmed gravitational lensing events discovered by the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). We succeed in disentangling the background galaxy from the lens to gain separate photometry of the two components. The HST data allow us to significantly improve on previous constraints of the mass in stars of the lensed galaxy and to perform accurate lens modelling of these systems, as described in the accompanying paper by Dye et al. We fit the spectral energy distributions of the background sources from near-IR to millimetre wavelengths and use the magnification factors estimated by Dye et al. to derive the intrinsic properties of the lensed galaxies. We find these galaxies to have star-formations rates (SFR) ∼ 400–2000 M⊙ yr−1, with ∼(6–25) × 1010 M⊙ of their baryonic mass already turned into stars. At these rates of star formation, all remaining molecular gas will be exhausted in less than ∼100 Myr, reaching a final mass in stars of a few 1011 M⊙. These galaxies are thus proto-ellipticals caught during their major episode of star formation, and observed at the peak epoch (z ∼ 1.5–3) of the cosmic star formation history of the Universe.Peer reviewe
Colour matters: the effects of lensing on the positional offsets between optical and submillimetre galaxies in Herschel★-ATLAS
No full textWe report an unexpected variation in the positional offset distributions between Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) submillimetre (submm) sources and their optical associations, depending on both 250-mu m signal-to-noise ratio and 250/350-mu m colour. We show that redder and brighter submm sources have optical associations with a broader distribution of positional offsets than would be expected if these offsets were due to random positional errors in the source extraction. The observation can be explained by two possible effects: either red submm sources trace a more clustered population than blue ones, and their positional errors are increased by confusion, or red submm sources are generally at high redshifts and are frequently associated with low-redshift lensing structures which are identified as false counterparts. We perform various analyses of the data, including the multiplicity of optical associations, the redshift and magnitude distributions in H-ATLAS in comparison to HerMES, and simulations of weak lensing, and we conclude that the effects are most likely to be explained by widespread weak lensing of Herschel-SPIRE sources by foreground structures. This has important consequences for counterpart identification and derived redshift distributions and luminosity functions of submm surveys.</p
Analysing the performance of KHFAC nerve block stimulation parameters: Developing design considerations for blocking the pudendal nerve using a new gate-dependent block determination model
No full textA major cause for voiding dysfunction is the inability to relax the urethral sphincter. KiloHertz Frequency Alternating Current (KHFAC) stimulation can block signals that are travelling through the body; applying this type of stimulation at the pudendal nerve could inhibit the pulses that lead to contraction of the urethral sphincter, and restore voiding ability. In order to design a successful KHFAC block therapy for the pudendal nerve, it is necessary to understand what impact different stimulation parameters have on efficacy, safety and power-efficiency. This thesis will therefore test earlier researched KHFAC stimulation parameters against a new quality measure, study the impact of new waveform alterations, and study how bipolar electrode design can improve KHFAC therapy. By utilizing the theory behind the mechanism of the KHFAC nerve block, a new block-determination model was developed that is over thirty times faster than the classic model. The McIntyre-Richardson-Grill model was chosen as the implementation of the axon model, and the bipolar electrode was modelled as an electric dipole. The simulation experiments revealed that the charge per phase of the KHFAC signal at block threshold could be reduced, without increasing the amplitude of the signal, by introducing interphase delays to the waveforms and by creating asymmetric charge-balanced waveforms. Triangular waveforms were shown to also require less charge per phase than a regular square wave to block, albeit with a higher amplitude. A correctly aligned bipolar electrode set-up with an interpolar distance that was about the same as the electrode-to-axon distance was shown to result in reduced block thresholds. Overall, this thesis has shown how stimulation parameters can be chosen to develop an effective KHFAC block therapy for the pudendal nerve.REValUEElectrical Engineerin
Parkisonian Resting Tremor: Source and Interaction with Movement
No full textBiologically inspired neural networks are a promising approach to understand the causes and improve the treatments of brain damage. Parkinson's disease is a progressive nervous system disorder that affects mainly movements, speech and cognitive problems. It symptoms cannot be cured, though medications can significantly improve the condition. Among the symptoms, tremor is the only one which remains unaffected by medications and is only responsive to deep-brain stimulation. A simplified, cortico-thalamo-cerebellar model will be simulated with spiking neural networks to evaluate the disease effects under dopamine depletion and connectivity weight changes. Confirming previous findings, striatal dopamine depletion was not found to cause tremor, nor its injection to affect tremor severity. The model showed evidence that parkinsonian weight changes in the pallidal inner feedback loop (GPi-GPe) are responsible of creating a suitable environment for the PD tremor oscillations to rise in the thalamus. Furthermore, both the GPi and the GPe present enhanced maximal activity coherent with muscular co-contraction onsets showing evidence of abnormal basal ganglia firing during re-emergent tremor. These findings may connect abnormal basal ganglia activity to the main parkinsonian motor impairments and may help explaining the beneficial effects of deep-brain stimulation on tremor severity
Scalable GPU Acceleration for Complex Brain Simulations
No full textComplex mathematical models are used in computational neuroscience to stimulate brain activity to understand the biological processes involved. The simulation of such models is computationally costly, and thus highperformancecomputing systems are selected as a potential solution to increase performance.This thesis aims to implement a new versatile, multi-GPU eHH simulator (mgpuHH), explore its performance and make general observations on performance scalability over different modeling and cluster configuration properties. This work offers a multinode multi-GPU solution that offers excellentscalability performance due to how the simulator is constructed, with the use of OpenMPI and CUDA. The simulator is configured with JSON configuration files, containing the neural descriptions and simulatorspecific settings. Consequently, enabling a userfriendly environment, for the neuroscientists, without the need of recompiling or understanding the source code. The gap junction calculations are identified as the critical function bottlenecking performance of the simulator. Therefore, an algorithm tailored to utilize GPU performance is implemented to decrease wallclock time for these specific calculations. For internodecommunication, OpenMPI can be configured in two ways. Eiter share all possible compartments potentials with every node in the network or only share the compartments potentials to nodes that need them. These methods rely internally on MPI Allgather and Alltoallv respectively. When available, GPUDirect, NVlink, and RDMA are supported. The implementation hides communication overhead, when possible, by concurrently executable compute kernels. A neuron model from the Inferior Olivary Nucleus is selected for benchmarking. Reported results go up to 32 Nodes with a total of 64 GPU cards. The design shows linear weak and strong scaling within the experimental setups for intranode and internode scalability. With this simulator, networks over 10 million cells become available to model on largescale GPU clusters, setting a new standard for eHH simulations. Comparisons against related work on CPU and FPGAs have been conducted, a 100x speedup is achieved versus a single cpu threaded solution. Furthermore, a 2x speedup is achieved over an FPGA solution (flexHH) and 10 fold over a multithreaded CPU (GenEHH, with 128 threads) solution, both reported speedups are for a fully connected network with 7000 IO cells.Computer Engineerin
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