Autismo e normotipicita' : analisi modellistica dei processi sensoriali

Negli ultimi anni molti studi sui fenomeni percettivi si sono concentrati sul problema dell’integrazione multisensoriale, ovvero la capacità del cervello di unire informazioni provenienti da modalità sensoriali diverse. Tale capacità può tuttavia essere compromessa nei soggetti autistici. Se nei soggetti normotipici, non vengono riscontrati problemi integrativi, nei soggetti affetti da disturbi dello spettro autistico(DSA), le capacità integrative sono altamente compromesse, specialmente nei bambini. In questo progetto di Tesi, attraverso l’utilizzo di una rete neurale, sono state simulate le risposte dei soggetti autistici e della loro controparte normotipica. Attraverso le varie simulazioni, si è visto che la causa delle possibili differenze tra i due soggetti risiede nell’indebolimento delle sinapsi feedforward, ovvero le sinapsi che si stabiliscono tra le aree unisensoriali e l’area multisensoriale, specificatamente le sinapsi tra l’area corticale visiva e l’area multisensoriale

Photon Scattering by an Electric Field in Noncommutative Spacetime

As is known, the existence of a small noncommutativity between coordinates would generate nonlocal self-interactions in the electromagnetic theory. To explore some consequences of this effect on the propagation of photons we consider Moyal space half-filled with a static and homogeneous electric field and analyze electromagnetic fluctuations on top of this step-like background. Both the localization of photons and the possibility of photon production by strong electric fields are addressed. Several aspects of the Klein paradox in this setup are discussed as well.Comment: 27 pages, 13 figure

Affine Killing vector fields on homogeneous surfaces with torsion

Many  extensions  of  General  Relativity  are  based  on  considering  metric  and  affine  structures as independent properties of spacetime.  This leads to the possibility of introducing torsion as an independent degree of freedom.  In this article we examine the effects of torsion on the affine Killing vectors of two-dimensional manifolds.  We give a complete description of the Lie algebras of affine Killing vector fields on homogeneous surfaces.  This can be used in the search of non-metrizable surfaces of interest.Fil: D'ascanio, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Gilkey, Peter. Mathematics Department, University Of Oregon; Estados UnidosFil: González Pisani, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentin

Renormalization on noncommutative torus

We study a self-interacting scalar φ4 theory on the d-dimensional noncommutative torus. We determine, for the particular cases d= 2 and d= 4 , the counterterms required by one-loop renormalization. We discuss higher loops in two dimensions and two-loop contributions to the self-energy in four dimensions. Our analysis points toward the absence of any problems related to the ultraviolet/infrared mixing and thus to renormalizability of the theory. However, we find another potentially troubling phenomenon which is a wild behavior of the two-point amplitude as a function of the noncommutativity matrix θ.Instituto de Física La Plat

Homocysteine, vitamin determinants and neurological diseases.

This review focuses on the putative role of hyper-homocysteinemia in the pathogenesis of different diseases affecting the nervous system, including stroke, Alzheimer's disease, Parkinson's disease, epilepsy, multiple sclerosis and amyotrophic lateral sclerosis. However, a firm pathogenic role of homocysteine in these diseases has never been established. Lowering plasma homocysteine levels trough vitamin therapy failed to prevent vascular diseases. Conversely, normalization of hyper-homocysteinemia caused improvement in patients with cognitive impairment. B vitamin deficiency is the main determinant of homocysteine levels. However, it has been hypothesized that homocysteine might be a mere marker of vitamin deficiency or an indicator of disease rather than a risk factor. A more consistent use of thresholds to define deficiency is needed to recommend routine screening, monitoring and supplementation of B vitamins to ameliorate the prognosis of the above mentioned disorders. To date, data are insufficient to firmly establish which one of the hypotheses made is correct and the question concerning the real meaning of hyper-homocysteinemia in the pathology of the nervous system still remains an intriguing medical dilemma

Intraoperative radiotherapy in gynaecological and genito-urinary malignancies: Focus on endometrial, cervical, renal, bladder and prostate cancers

Intraoperative radiotherapy (IORT) refers to the delivery of a single radiation dose to a limited volume of tissue during a surgical procedure. A literature review was performed to analyze the role of IORT in gynaecological and genito-urinary cancer including endometrial, cervical, renal, bladder and prostate cancers. Literature search was performed by Pubmed and Scopus, using the words "intraoperative radiotherapy/IORT", "gynaecological cancer", "uterine/endometrial cancer", "cervical/cervix cancer", "renal/kidney cancer", "bladder cancer" and "prostate cancer". Forty-seven articles were selected from the search databases, analyzed and briefly described. Literature data show that IORT has been used to optimize local control rate in genito-urinary tumours mainly in retrospective studies. The results suggest that IORT could be advantageous in the setting of locally advanced and recurrent disease although further prospective trials are needed to confirm this findings

Affine Killing vector fields on homogeneous surfaces with torsion

Many extensions of general relativity are based on considering metric and affine structures as independent properties of spacetime. This leads to the possibility of introducing torsion as an independent degree of freedom. In this article we examine the effects of torsion on the affine Killing vectors of two-dimensional manifolds. We give a complete description of the Lie algebras of affine Killing vector fields on homogeneous surfaces. This can be used in the search of non-metrizable surfaces of interest.Instituto de Física La Plat

Renormalization on noncommutative torus

We study a self-interacting scalar φ4 theory on the d-dimensional noncommutative torus. We determine, for the particular cases d= 2 and d= 4 , the counterterms required by one-loop renormalization. We discuss higher loops in two dimensions and two-loop contributions to the self-energy in four dimensions. Our analysis points toward the absence of any problems related to the ultraviolet/infrared mixing and thus to renormalizability of the theory. However, we find another potentially troubling phenomenon which is a wild behavior of the two-point amplitude as a function of the noncommutativity matrix θ.Instituto de Física La Plat

Quality of life in patients treated by adjuvant radiotherapy for endometrial and cervical cancers: correlation with dose\u2013volume parameters

INTRODUCTION: Modern multidisciplinary cancer treatments aim at obtaining minimal influence on patients' quality of life (QoL). The purpose of this study was to assess QoL and correlate it with dose-volume parameters of organ at risks (OARs) in patients who received adjuvant radiotherapy for endometrial and cervical cancers. MATERIALS AND METHODS: We administered the EORTC QLQ-C30 and EN24 or CX24 questionnaires to 124 patients, 100 with endometrial cancer and 24 with cervical cancer treated with postoperative radiotherapy \ub1 chemotherapy in regular follow-up. Bladder function, fecal incontinence or urgency and sexual functioning were investigated and correlated with dose-volume parameters of OAR by multiple linear regression analysis. This correlation was assessed by R (2) value. RESULTS: QoL was very high in the majority of patients (82.3 % of patients). Few patients referred urinary incontinence (3.2 %) or abdominal discomfort of high grade (4.0 %). We found a significant correlation between bladder V40, i.e., absolute percentage of bladder volume that received a dose of 40 Gy, and global health status (p < 0.05, R (2) = 0.17), urinary urgency (p < 0.05, R (2) = 0.24), urinary incontinence (p < 0.05, R (2) = 0.23) and dyspareunia (p < 0.05, R (2) = 0.04). We found also a correlation between global health status and mean dose to vagina (p < 0.05, R (2) = 0.17) and between maximum dose to lumbo-sacral plexus and abdominal pain (p < 0.05, R (2) = 0.07). CONCLUSIONS: Women treated with surgery and adjuvant radiotherapy for endometrial and cervical cancers have good QoL with minimal limitations of daily activities. QoL was correlated with dose-volume parameters such as bladder V40, mean dose to vagina, maximum dose to trigone and LSP