Kalman tracking linear predictor for vowel intelligibility enhancement on european portuguese HMM based speech synthesis

The recent developments on Hidden Markov Models (HMM) based speech synthesis showed that this is a promising technology fully capable of competing with other established techniques. However some issues still lack a solution. Several authors report an over-smoothing phenomenon on both time and frequencies which decreases naturalness and sometimes intelligibility. In this work we present a new vowel intelligibility enhancement algorithm that uses a discrete Kalman filter (DKF) for tracking frame based parameters. The inter-frame correlations are modelled by an autoregressive structure which provides an underlying time frame dependency and can improve time-frequency resolution. The system’s performance has been evaluated using objective and subjective tests and the proposed methodology has led to improved results.

Adaptive filtering for high quality HMM based speech synthesis

In this work an adaptive filtering scheme based on a dual Discrete Kalman Filtering (DKF) is proposed for Hidden Markov Model (HMM) based speech synthesis quality enhancement. The objective is to improve signal smoothness across HMMs and their related states and to reduce artifacts due to acoustic model's limitations. Both speech and artifacts are modelled by an autoregressive structure which provides an underlying time frame dependency and improves time-frequency resolution. Themodel parameters are arranged to obtain a combined state-space model and are also used to calculate instantaneous power spectral density estimates. The quality enhancement is performed by a dual discrete Kalman filter that simultaneously gives estimates for the models and the signals. The system's performance has been evaluated using mean opinion score tests and the proposed technique has led to improved results.

Induction of phagocytic activity and nitric-oxide production in natural populations of Trypanosoma Cruzi I and II from the state of Paraná, Brazil

Twelve strains of Trypanosoma cruzi isolated from wild reservoirs, triatomines, and chronic chagasic patients in the state of Paraná, southern Brazil, and classified as T. cruzi I and II, were used to test the correlation between genetic and biological diversity. The Phagocytic Index (PI) and nitric-oxide (NO) production in vitro were used as biological parameters. The PI of the T. cruzi I and II strains did not differ significantly, nor did the PI of the T. cruzi strains isolated from humans, triatomines, or wild reservoirs. There was a statistical difference in the inhibition of NO production between T. cruzi I and II and between parasites isolated from humans and the strains isolated from triatomines and wild reservoirs, but there was no correlation between genetics and biology when the strains were analyzed independently of the lineages or hosts from which the strains were isolated. There were significant correlations for Randomly Amplified Polymorphic Deoxyribonucleic acid (RAPD) and biological parameters for T. cruzi I and II, and for humans or wild reservoirs when the lineages or hosts were considered individually.

Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films

Dissertation to obtain the degree of master in Bioorganic

Vulvar Lichen Sclerosus: Efficacy of Photodynamic Therapy Under Conscious Sedation with Inhaled 50% Nitrous Oxide and Oxygen Mixture

Anogenital lichen sclerosus is a chronic, inflammatory, mucocutaneous disorder of significant morbidity. Common symptoms include pruritus, pain, dysuria, and dyspareunia, frequently of difficult control. Photodynamic therapy (PDT) may be an effective therapeutic option in selected cases refractory to first--‐line treatment options. However, procedure--‐related pain is a limiting factor in patient adherence to treatment. Conscious sedation and analgesia with a ready--‐to--‐use gas mixture of nitrous oxide and oxygen is useful in short--‐term procedures. It provides a rapid, effective, and short--‐lived effect, without the need for anesthesiology support. A 75--‐year--‐old woman presented with a highly symptomatic, histologically confirmed vulvar lichen sclerosus, with at least 15 years of evolution. Pain, pruritus, and dysuria were intense and disabling. Treatment with ultrapotent topical corticosteroids proved to be ineffective despite patient compliance. She was then referred for PDT. A total of 3 sessions were performed, held at a mean interval of 9 weeks, and under the analgesic and sedative effect of nitrous oxide/oxygen gas. Response to treatment was evaluated through a daily, self--‐reported pain rating scale. Dysuria remitted completely after the first PDT session. An 80% reduction in pruritus and pain was observed after the third session, and has been sustained for the past six months without further need for topical corticotherapy. Treatment sessions were well tolerated and pain-- free, with no side effects to report. PDT appears to be effective in the symptomatic treatment of vulvar lichen sclerosus. To the authors’ knowledge this is the first case reporting the use of inhaled nitrous oxide/oxygen gas mixture during PDT performed in the genital area. Its analgesic and sedative effects may increase patients’ adherence to this painful procedure. Furthermore, given its safety, it can be easily managed in outpatient clinics by trained dermatologists.

ANTIFUNGAL ACTIVITY OF SILVER NANOPARTICLES OBTAINED BY GREEN SYNTHESIS

Silver nanoparticles (AgNPs) are metal structures at the nanoscale. AgNPs have exhibited antimicrobial activities against fungi and bacteria; however synthesis of AgNPs can generate toxic waste during the reaction process. Accordingly, new routes using non-toxic compounds have been researched. The proposal of the present study was to synthesize AgNPs using ribose as a reducing agent and sodium dodecyl sulfate (SDS) as a stabilizer. The antifungal activity of these particles against C. albicans and C. tropicalis was also evaluated. Stable nanoparticles 12.5 ± 4.9 nm (mean ± SD) in size were obtained, which showed high activity against Candida spp. and could represent an alternative for fungal infection treatment.

Insights into cell wall synthesis and cell division in Staphylococcus aureus

Dissertation presented to obtain the Ph.D degree in Biology

Quantum dots: synthesis, functionalization and bioconjugation for biological applications

Dissertation presented to obtain the Ph.D degree in Engineering Sciences and Technology

The electron transfer complex between nitrous oxide reductase and its electron donors

J Biol Inorg Chem (2011) 16:1241–1254 DOI 10.1007/s00775-011-0812-9

Low-Spin Heme b3 in the Catalytic Center of Nitric Oxide Reductase from Pseudomonas nautica

Biochemistry, 2011, 50 (20), pp 4251–4262 DOI: 10.1021/bi101605p

The tetranuclear copper active site of nitrous oxide reductase: the CuZ center

J Biol Inorg Chem (2011) 16:183–194 DOI 10.1007/s00775-011-0753-3

A new CuZ active form in the catalytic reduction of N2O by nitrous oxide reductase from Pseudomonas nautica

J Biol Inorg Chem (2010) 15:967–976 DOI 10.1007/s00775-010-0658-6

Camelid nanobodies raised against an integral membrane enzyme, nitric oxide reductase

Protein Sci. 2009 Mar;18(3):619-28. doi: 10.1002/pro.69.

Electron transfer complex between nitrous oxide reductase and cytochrome c552 from Pseudomonas nautica: kinetic, nuclear magnetic resonance, and docking studies

Biochemistry. 2008 Oct 14;47(41):10852-62. doi: 10.1021/bi801375q

Activation of N2O reduction by the fully reduced micro4-sulfide bridged tetranuclear Cu Z cluster in nitrous oxide reductase

J. Am. Chem. Soc., 2003, 125 (51), pp 15708–15709 DOI: 10.1021/ja038344n