"Cloudy": un'applicazione di assistenza allo shopping basata sulle API di Marketcloud

In questo lavoro di tesi si è analizzato il problema di creare un sistema di assistenza allo shopping integrabile in applicazioni e-commerce web e mobile sviluppate con le tecnologie messe a disposizione da Marketcloud, ovvero un progetto che punta a fornire strumenti per la realizzazione, la manutenzione, la gestione, la diffusione e la pubblicizzazione di tali applicazioni limitando i costi e le problematiche di sviluppo a carico delle aziende che intendono fornire servizi di e-commerce. Dopo aver discusso gli aspetti principali del progetto Marketcloud, sono state analizzate le necessità delle aziende interessate allo sviluppo del sistema di assistenza in esame, così come le aspettative degli utenti (i clienti) finali, ed è stato discusso perché fosse necessario e preferibile, nel caso in esame, non utilizzare soluzioni già presenti sul mercato. Infine, è stata progettata ed implementata un’applicazione web che includesse tale sistema e che fosse immediatamente integrabile tra i servizi già sviluppati da Marketcloud, testandone risultati, prestazioni, problemi e possibili sviluppi futuri. Al termine del lavoro di implementazione, il sistema e l'applicazione garantiscono all'utente finale l'utilizzo di tre funzioni: ricerca per categoria, ricerca libera, recommendation di prodotti. Per gestire la ricerca libera, è stato implementato un sistema di filtri successivi, ed una rete neurale multi-livello dotata di un opportuno algoritmo di machine learning per poter apprendere dalle scelte degli utenti; per la recommendation di prodotti, è stato utilizzato un sistema di ranking (classificazione). Le prestazioni della rete neurale sono state oggetto di attenta analisi.

Analisi time history per la valutazione degli scorrimenti in strutture prefabbricate con collegamenti attritivi non progettati con criteri antisismici

In questo lavoro si è tentato di fornire un metodo per la calibrazione di modelli numerici in analisi dinamiche spettrali. Attraverso una serie di analisi time history non lineari sono stati ottenuti gli spostamenti relativi orizzontali che nascono, in corrispondenza della connessione trave-pilastro di tipo attritivo, quando una struttura prefabbricata monopiano viene investita dalla componente orizzontale e verticale del sisma. Con un procedimento iterativo su varie analisi spettrali sono state calibrate delle rigidezze equivalenti che hanno permesso di ottenere, con buona approssimazione, gli stessi risultati delle analisi time history. Tali rigidezze sono state poi restituite in forma grafica. Per riprodurre gli spostamenti relativi orizzontali con un’analisi dinamica spettrale è quindi possibile collegare le travi ai pilastri con degli elementi elastici aventi rigidezza Kcoll. I valori di rigidezza restituiti da questo studio valgono per un’ampia gamma di prefabbricati monopiano (periodo proprio 0.20s < T < 2.00s) e tre differenti livelli di intensità sismica; inoltre è stata data la possibilità di considerare la plasticizzazione alla base dei pilastri e di scegliere fra due diverse posizioni nei confronti della rottura di faglia (Near Fault System o Far Fault System). La diminuzione di forza d’attrito risultante (a seguito della variazione dell’accelerazione verticale indotta dal sisma) è stata presa in considerazione utilizzando un modello in cui fra trave e pilastro è posto un isolatore a pendolo inverso (opportunamente calibrato per funzionare come semplice appoggio ad attrito). Con i modelli lineari equivalenti si riescono ad ottenere buoni risultati in tempi relativamente ridotti: è possibile così compiere delle valutazioni approssimate sulla perdita di appoggio e sulle priorità d’intervento in una determinata zona sismica.

L'individuazione automatica di plagio fra codici sorgente

Obiettivo di questa tesi è raccogliere e ordinare le informazioni disponibili sul plagio fra codici sorgente, con particolare attenzione alla classificazione dei tipi di plagio fra codici e all’analisi dei principali tool esistenti per l’individuazione automatica. Dall’ampia letteratura disponibile sull’argomento, emerge che la rivoluzione informatica ha suscitato nel mondo giuridico un profondo dibattito in merito alla definizione del software e agli strumenti di tutela ad esso connessi, perciò ho deciso di dedicare un capitolo anche alla riflessione sul contesto giuridico e normativo, in Italia e nel mondo. Poiché non esiste una bacchetta magica per combattere il plagio, è realistico pensare che utilizzare diverse tecniche fra loro complementari possa dare risultati migliori; alcuni approcci innovativi in tal senso, derivanti principalmente da ricerche effettuate nel mondo accademico, sono descritti nel capitolo conclusivo della tesi. Un altro aspetto del problema che mi ha colpito è la questione etica connessa al plagio. Molti studiosi universitari hanno realizzato sondaggi all’interno della comunità accademica per testare il grado di sensibilità al problema del plagio e proposto diverse soluzioni volte non solo a combattere il plagio ma anche a prevenirlo, puntando sullo sviluppo di una maggiore consapevolezza del problema negli accademici (sia studenti che docenti). Anche in ambito commerciale non mancano tentativi di sfuggire alla piaga del plagio, considerato a tutti gli effetti una forma di pirateria informatica. Alcuni di questi studi, i cui risultati offrono interessanti spunti di riflessione per il futuro, sono riportati nel capitolo dedicato alle conclusioni.

Quantum Mechanical Study of Sulfuric Acid Hydration: Atmospheric Implications

The role of the binary nucleation of sulfuric acid in aerosol formation and its implications for global warming is one of the fundamental unsettled questions in atmospheric chemistry. We have investigated the thermodynamics of sulfuric acid hydration using ab initio quantum mechanical methods. For H2SO4(H2O)n where n = 1–6, we used a scheme combining molecular dynamics configurational sampling with high-level ab initio calculations to locate the global and many low lying local minima for each cluster size. For each isomer, we extrapolated the Møller–Plesset perturbation theory (MP2) energies to their complete basis set (CBS) limit and added finite temperature corrections within the rigid-rotor-harmonic-oscillator (RRHO) model using scaled harmonic vibrational frequencies. We found that ionic pair (HSO4–·H3O+)(H2O)n−1 clusters are competitive with the neutral (H2SO4)(H2O)n clusters for n ≥ 3 and are more stable than neutral clusters for n ≥ 4 depending on the temperature. The Boltzmann averaged Gibbs free energies for the formation of H2SO4(H2O)n clusters are favorable in colder regions of the troposphere (T = 216.65–273.15 K) for n = 1–6, but the formation of clusters with n ≥ 5 is not favorable at higher (T > 273.15 K) temperatures. Our results suggest the critical cluster of a binary H2SO4–H2O system must contain more than one H2SO4 and are in concert with recent findings(1) that the role of binary nucleation is small at ambient conditions, but significant at colder regions of the troposphere. Overall, the results support the idea that binary nucleation of sulfuric acid and water cannot account for nucleation of sulfuric acid in the lower troposphere.

Quantum Mechanical Study of Sulfuric Acid Hydration: Atmospheric Implications

The role of the binary nucleation of sulfuric acid in aerosol formation and its implications for global warming is one of the fundamental unsettled questions in atmospheric chemistry. We have investigated the thermodynamics of sulfuric acid hydration using ab initio quantum mechanical methods. For H2SO4(H2O)n where n = 1–6, we used a scheme combining molecular dynamics configurational sampling with high-level ab initio calculations to locate the global and many low lying local minima for each cluster size. For each isomer, we extrapolated the Møller–Plesset perturbation theory (MP2) energies to their complete basis set (CBS) limit and added finite temperature corrections within the rigid-rotor-harmonic-oscillator (RRHO) model using scaled harmonic vibrational frequencies. We found that ionic pair (HSO4–·H3O+)(H2O)n−1clusters are competitive with the neutral (H2SO4)(H2O)n clusters for n ≥ 3 and are more stable than neutral clusters for n ≥ 4 depending on the temperature. The Boltzmann averaged Gibbs free energies for the formation of H2SO4(H2O)n clusters are favorable in colder regions of the troposphere (T = 216.65–273.15 K) for n = 1–6, but the formation of clusters with n ≥ 5 is not favorable at higher (T > 273.15 K) temperatures. Our results suggest the critical cluster of a binary H2SO4–H2O system must contain more than one H2SO4 and are in concert with recent findings(1) that the role of binary nucleation is small at ambient conditions, but significant at colder regions of the troposphere. Overall, the results support the idea that binary nucleation of sulfuric acid and water cannot account for nucleation of sulfuric acid in the lower troposphere.

Product Distributions Following Hyperthermal Collisions Between C2H4 And O(3P)

Transient Diode Laser Absorption Spectroscopy (TDLAS) was used to perform vibrational state population studies of the CO2 product from the hyperthermal reaction between C2H4 and O(3P) at room temperature using O3 as the O-atom precursor. Photodissociation of O3 using a frequency quadrupled Q-switch Nd:YAG laser pulse at 266 nm produced O(3P) atoms at high velocities which subsequently reacted with C2H4, producing several primary and secondary products including CO2. The CO2 product was detected using high-resolution TDLAS under five unique sets of reaction conditions. The vibrational distribution of the CO2 product did not follow a Boltzmann distribution at all five sets of conditions. The experiments showed a distribution in which there was a surprisingly high population in the (1000) (symmetric stretching) state compared with the other states probed, all of which contained bend excitation. In general, the CO2 population in the (1000) state was about 15-20% more populated than the Boltzmann distribution predicts. A possible explanation for this result may lie in the mechanism of CO2 evolution from the C2H4 + O(3P) reaction.

Vascular dysfunction and reduced circulating endothelial progenitor cells in young healthy UK South Asian men

OBJECTIVES: The objective of this study was to examine determinants of excess coronary artery disease risk in UK South Asians, more prevalent in this population than UK Caucasians, by examining differences in risk factors, vascular function, and endothelial progenitor cells (EPCs). METHODS AND RESULTS: 24 South Asian and 25 Caucasian healthy age-matched nonsmoking men were studied. Vascular function was assessed by flow-mediated and GTN brachial artery dilatation and blood flow responses to infusion of ACh, SNP, and L-NMMA. EPC number and function were measured by flow cytometry (CD34, CD133, and KDR positive cells), and CFU/migration assays. Traditional risk factors and anthropometric measurements were similar in the groups. South Asians had higher fasting insulin levels (6.01 versus 3.62 microU/mL; P = 0.02). South Asians had lower FMD (6.9 versus 8.5%; P = 0.003), L-NMMA response (0.8 versus 1.3 mL/min/100 mL; P = 0.03), mean SNP response (9.5+/-0.6 versus 11.6+/-0.6; P = 0.02), EPC number (0.046+/-0.005% versus 0.085+/-0.009%; P = < 0.001), and CFU ability (CFU 4.29+/-1.57 versus 18.86+/-4.00; P = 0.005). EPC number was the strongest predictor of FMD. Ethnicity was the strongest predictor of EPC number. CONCLUSIONS: Healthy South Asian men are more insulin resistant, and demonstrate endothelial dysfunction and reduced EPC number and function compared with Caucasians. These abnormalities may contribute to their increased CAD risk.

Transport model of the human Na+-coupled L-ascorbic acid (vitamin C) transporter SVCT1

Vitamin C (L-ascorbic acid) is an essential micronutrient that serves as an antioxidant and as a cofactor in many enzymatic reactions. Intestinal absorption and renal reabsorption of the vitamin is mediated by the epithelial apical L-ascorbic acid cotransporter SVCT1 (SLC23A1). We explored the molecular mechanisms of SVCT1-mediated L-ascorbic acid transport using radiotracer and voltage-clamp techniques in RNA-injected Xenopus oocytes. L-ascorbic acid transport was saturable (K(0.5) approximately 70 microM), temperature dependent (Q(10) approximately 5), and energized by the Na(+) electrochemical potential gradient. We obtained a Na(+)-L-ascorbic acid coupling ratio of 2:1 from simultaneous measurement of currents and fluxes. L-ascorbic acid and Na(+) saturation kinetics as a function of cosubstrate concentrations revealed a simultaneous transport mechanism in which binding is ordered Na(+), L-ascorbic acid, Na(+). In the absence of L-ascorbic acid, SVCT1 mediated pre-steady-state currents that decayed with time constants 3-15 ms. Transients were described by single Boltzmann distributions. At 100 mM Na(+), maximal charge translocation (Q(max)) was approximately 25 nC, around a midpoint (V(0.5)) at -9 mV, and with apparent valence approximately -1. Q(max) was conserved upon progressive removal of Na(+), whereas V(0.5) shifted to more hyperpolarized potentials. Model simulation predicted that the pre-steady-state current predominantly results from an ion-well effect on binding of the first Na(+) partway within the membrane electric field. We present a transport model for SVCT1 that will provide a framework for investigating the impact of specific mutations and polymorphisms in SLC23A1 and help us better understand the contribution of SVCT1 to vitamin C metabolism in health and disease.

Proteins in silico-modeling and sampling

Proteins are linear chain molecules made out of amino acids. Only when they fold to their native states, they become functional. This dissertation aims to model the solvent (environment) effect and to develop & implement enhanced sampling methods that enable a reliable study of the protein folding problem in silico. We have developed an enhanced solvation model based on the solution to the Poisson-Boltzmann equation in order to describe the solvent effect. Following the quantum mechanical Polarizable Continuum Model (PCM), we decomposed net solvation free energy into three physical terms– Polarization, Dispersion and Cavitation. All the terms were implemented, analyzed and parametrized individually to obtain a high level of accuracy. In order to describe the thermodynamics of proteins, their conformational space needs to be sampled thoroughly. Simulations of proteins are hampered by slow relaxation due to their rugged free-energy landscape, with the barriers between minima being higher than the thermal energy at physiological temperatures. In order to overcome this problem a number of approaches have been proposed of which replica exchange method (REM) is the most popular. In this dissertation we describe a new variant of canonical replica exchange method in the context of molecular dynamic simulation. The advantage of this new method is the easily tunable high acceptance rate for the replica exchange. We call our method Microcanonical Replica Exchange Molecular Dynamic (MREMD). We have described the theoretical frame work, comment on its actual implementation, and its application to Trp-cage mini-protein in implicit solvent. We have been able to correctly predict the folding thermodynamics of this protein using our approach.

A 45nm CMOS DESIGN OF NEUROMORPHIC SYSTEM

Neuromorphic computing has become an emerging field in wide range of applications. Its challenge lies in developing a brain-inspired architecture that can emulate human brain and can work for real time applications. In this report a flexible neural architecture is presented which consists of 128 X 128 SRAM crossbar memory and 128 spiking neurons. For Neuron, digital integrate and fire model is used. All components are designed in 45nm technology node. The core can be configured for certain Neuron parameters, Axon types and synapses states and are fully digitally implemented. Learning for this architecture is done offline. To train this circuit a well-known algorithm Restricted Boltzmann Machine (RBM) is used and linear classifiers are trained at the output of RBM. Finally, circuit was tested for handwritten digit recognition application. Future prospects for this architecture are also discussed.

DEFINING THE ROLE OF EGFR ACETYLATION IN CELLULAR PROCESSES: CLINICAL IMPLICATIONS

Epidermal growth factor receptor (EGFR) is a cell membrane tyrosine kinase receptor and plays a pivotal role in regulating cell growth, differentiation, cell cycle, and tumorigenesis. Deregulation of EGFR causes many diseases including cancers. Intensive investigation of EGFR alteration in human cancers has led to profound progress in developing drugs to target EGFR-mediated cancers. While exploring possible synergistic enhancement of therapeutic efficacy by combining EGFR tyrosine kinase inhibitors (TKI) with other anti-cancer agents, we observed that suberoylanilide hydroxamic acid (SAHA, a deacetylase inhibitor) enhanced TKI-induced cancer cell death, which further led us to question whether SAHA-mediated sensitization to TKI was associated with EGFR acetylation. What we know so far is that SAHA can inhibit class I and II histone deacetylases (HDACs), which could possibly preserve acetylation of underlying HDAC-targeted proteins including both histone and non-histone proteins. In addition, it has been reported that an HDAC inhibitor, TSA, enhanced EGFR phosphorylation in ovarian cancer cells. EGFR acetylation has also been reported to play a role in the regulation of EGFR endocytosis recently. These observations indicate that there might be an intrinsic correlation between acetylation and phosphorylation of EGFR. In other words, the interplay between EGFR acetylation and phosphorylation may contribute to HDAC inhibitors (HDACi)-augmented EGFR phosphorylation. In this investigation, we showed that CBP acetyltransferase acetylated EGFR in vivo. In response to EGF stimulation, CBP rapidly translocated from the nucleus to the cytoplasm. We also demonstrated protein-protein interaction between CBP and EGFR as well as the enhancement of EGFR acetylation by CBP. Moreover, EGFR acetylation enhanced EGFR tyrosine phosphorylation and augmented its association with Src kinase. Acetylation-deficient EGFR mutant (EGFR-K3R) significantly reduced the function and activity of EGFR. Furthermore, ectopic expression of EGFR-K3R mutant abrogated its ability to respond to EGF-induced cell proliferation, DNA synthesis, and anchorage-independent growth using cell-based assays and tumor growth in nude mice. In addition, we demonstrated that EGFR expression was associated with SAHA resistance in the treatment of cancer cells that overexpress EGFR. The knockdown of EGFR in MDA-MB-468 breast cancer cells could sensitize the cells to respond to SAHA. The overexpression of EGFR in SAHA-sensitive MDA-MB-453 breast cancer cells rendered the cells resistant to SAHA. Together, these findings suggest that EGFR plays an important role in SAHA resistance in breast carcinoma cells that we tested. The combination therapy of HDACi with TKI has been proposed for treating cancers with aberrant expression of EGFR. The evidence from pre-clinical or clinical trials demonstrated significant enhancement of therapeutic efficacy by using such a combination therapy. Our in vivo study also demonstrated that the combination of SAHA and TKI for the treatment of breast cancer significantly reduced tumor burden compared with either SAHA or TKI alone. The significance of our study elucidated another possible underlying molecular mechanism by which HDACi mediated sensitization to TKI. Our results unveiled a critical role of EGFR acetylation that regulates EGFR tyrosine phosphorylation and may further provide an experiment-based rationale for combinatorial targeted therapy.

Neonatal outcomes of extremely preterm infants from the NICHD Neonatal Research Network.

OBJECTIVE: This report presents data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network on care of and morbidity and mortality rates for very low birth weight infants, according to gestational age (GA). METHODS: Perinatal/neonatal data were collected for 9575 infants of extremely low GA (22-28 weeks) and very low birth weight (401-1500 g) who were born at network centers between January 1, 2003, and December 31, 2007. RESULTS: Rates of survival to discharge increased with increasing GA (6% at 22 weeks and 92% at 28 weeks); 1060 infants died at CONCLUSION: Although the majority of infants with GAs of >or=24 weeks survive, high rates of morbidity among survivors continue to be observed.