221 research outputs found

    Automatic Phrase Continuation from Guitar and Bass guitar Melodies

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    A framework is proposed for generating interesting, musically similar variations of a given monophonic melody. The focus is on pop/rock guitar and bass guitar melodies with the aim of eventual extensions to other instruments and musical styles. It is demonstrated here how learning musical style from segmented audio data can be formulated as an unsupervised learning problem to generate a symbolic representation. A melody is first segmented into a sequence of notes using onset detection and pitch estimation. A set of hierarchical, coarse-to-fine symbolic representations of the melody is generated by clustering pitch values at multiple similarity thresholds. The variance ratio criterion is then used to select the appropriate clustering levels in the hierarchy. Note onsets are aligned with beats, considering the estimated meter of the melody, to create a sequence of symbols that represent the rhythm in terms of onsets/rests and the metrical locations of their occurrence. A joint representation based on the cross-product of the pitch cluster indices and metrical locations is used to train the prediction model, a variable-length Markov chain. The melodies generated by the model were evaluated through a questionnaire by a group of experts, and received an overall positive response. </jats:p

    Quality of vision and outcomes after bilateral implantation of pseudo-non diffracting beam IOL

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    Purpose: To analyze the objective and subjective visual performances of a new hybrid refractive/aspheric extended depth of focus (EDOF) intraocular lens (IOL). Methods: In this monocentric prospective study patients with bilateral cataracts underwent cataract surgery and were implanted with a Lucidis IOL (SAV-IOL SA, Neuchâtel, Switzerland) in both eyes, 1 week apart from each other. At 3 months from implantation postoperative evaluations included monocular and binocular uncorrected and distance-corrected distant (4 m), intermediate (80 cm, 67 cm) and near (40 cm) visual acuities (UDVA/DCVA, UI80-67VA/DCI80-67VA, UNVA/DCNVA), binocular defocus curves, halometry, contrast sensitivity and objective quality-of-vision measurements. Also, patients were also asked to complete the national eye institute refractive error quality of life (NEI-RQL-42) questionnaire. Results: Twenty-five patients (50 eyes) were included. The mean postoperative binocular UDVA, UI80VA, UI67VA and UNVA were-0.02 ± 0.13, 0.05 ± 0.09, 0.05 ± 0.08 and 0.03 ± 0.1 LogMar, and did not significantly differ from their corrected counterparts. On binocular defocus curves a VA ≥0.05LogMar was found between +0.50 and - 2.50 D of vergence, whereas the mean distance from the central stimulus on halometry was 1.23 ± 0.01. Mean ocular and corneal radical mean square at 4 mm were 0.31 ± 0.28 and 0.19 ± 0.07, respectively; whereas the mean Strehl ratio was 0.2 ± 0.09. Conclusion: Lucidis IOLs demonstrated excellent visual performances, especially at close distances while maintain good quality of vision, contrast sensitivity, and overall patient-satisfaction

    Mitogen-activated protein kinase kinase 5 regulates proliferation and biosynthetic processes in procyclic forms of Trypanosoma brucei

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    The pathogenic protozoan T. brucei alternates into distinct developmental stages in the mammalian and insect hosts. The mitogen-activated protein kinase (MAPK) signaling pathways transduce extracellular stimuli into a range of cellular responses, which ultimately lead to the adaptation to the external environment. Here, we combined a loss of function approach with stable isotope labeling with amino acids in cell culture (SILAC)-based mass spectrometry (MS) to investigate the role of the mitogen-activated protein kinase kinase 5 (MKK5) in T. brucei. The silencing of MKK5 significantly decreased the proliferation of procyclic forms of T. brucei. To shed light on the molecular alterations associated with this phenotype, we measured the total proteome and phosphoproteome of cells silenced for MKK5. In the total proteome, we observed a general decrease in proteins related to ribosome and translation as well as down-regulation of several components of the fatty acids biosynthesis pathway. In addition, we observed alterations in the protein levels and phosphorylation of key metabolic enzymes, which point toward a suppression of the oxidative metabolism. Taken together, our findings show that the silencing of MKK5 alters cell growth, energy metabolism, protein and fatty acids biosynthesis in procyclic T. brucei

    The role of topical povidone-iodine in the management of infectious keratitis: a pilot study

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    The aim of this prospective explorative study was to evaluate the safety and the effectiveness of topical polyvinylpyrrolidone-iodine (PVP-I) administered during the time-to-results period for pathogen identification and susceptibility testing in patients with infectious keratitis (IK). A corneal swab (CS) for antimicrobial evaluation was performed at enrollment (T0) and topical 0.66%-PVP-I was administered until the laboratory results were available (T1). Ulcer and infiltrate areas and infiltrate depths were compared between T0 and T1 (i.e., time-to-result period). Patients were then shifted to a specific antimicrobial therapy and followed up until resolution of their infiltrates (Tlast-TL). Twenty-five eyes were enrolled, and none showed clinical worsening leading to protocol withdrawal. At T1, ulcer and infiltrate areas showed significant improvement in Gram-positive IK (n = 13-52%; p = 0.027 and p = 0.019, respectively), remained stable in fungal IK (n = 5-20%; both p = 0.98) and increased in those with Gram-negative bacteria (n = 4-16%; p = 0.58 and p = 0.27). Eyes with negative cultures (n = 3-12%) showed complete resolution at T1 and did not initiate any additional antimicrobial therapy. The administration of 0.66% PVP-I during the time-to-result period seems to be a safe strategy in patients with IK while often sparing broad-spectrum antimicrobial agents. In addition, it showed to be effective in eyes with a Gram-positive bacterial infection

    In vivo confocal microscopy study of corneal nerve alterations in children and youths with Type 1 Diabetes

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    Objective: To determine whether children and youths with type 1 diabetes (T1D) have early alterations of the corneal subbasal nerve plexus detectable with In vivo confocal microscopy (IVCM) and to investigate the role of longitudinally measured major risk factors for diabetes complications associated with these alterations. Methods: One hundred and fifty children and youths with T1D and 51 age-matched controls were enrolled and underwent IVCM. Corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal fiber total branch density (CTBD), and corneal fiber fractal dimension (CNFrD) were measured. Risk factors for diabetes complications (blood pressure, BMI, HbA1c, lipoproteins, urinary albumin-creatinine ratio) were recorded at IVCM and longitudinally since T1D onset. Unpaired t-test was used to compare variables between the groups. Multiple regression models were calculated using IVCM parameters as dependent variables and risk factors as independent variables. Results: All IVCM parameters, except CTBD, were significantly lower in the T1D patients. Glycometabolic control (HbA1c, visit-to-visit HbA1c variability, and mean HbA1c), and blood pressure were inversely correlated with IVCM parameters. Multiple regression showed that part of the variability in CNFL, CNFD, CTBD, and CNFraD was explained by HbA1c, blood pressure percentiles, and age at IVCM examination, independent of diabetes duration, BMI percentile, and LDL cholesterol. Comparable results were obtained using the mean value of risk factors measured longitudinally since T1D onset. Conclusions: Early signs of corneal nerve degeneration were found in children and youths with T1D. Glycometabolic control and blood pressure were the major risk factors for these alterations. This article is protected by copyright. All rights reserved

    Rat subcutaneous tissue response to MTA Fillapex® and Portland cement

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    The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (?=0.05). Statistically significant difference (p<0.05) was found only between PCPG at 15 days and ZOEI at 7 days groups. No significant differences were observed among the other groups/periods (p>0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.O objetivo deste estudo foi avaliar a resposta do tecido subcutâneo de rato ao MTA Fillapex® (Angelus), a um cimento endodôntico experimental à base de cimento Portland e propilenoglicol, e à pasta de óxido de zinco e eugenol com iodofórmio. Estes materiais foram colocados em tubos de polietileno e implantados no tecido conjuntivo do dorso de ratos Wistar, por 7 e 15 dias. Os espécimes foram corados com hematoxilina e eosina e os parâmetros de reação inflamatória foram avaliados em microscópio óptico. A intensidade da resposta inflamatória provocada pelos cimentos foi analisada em todos os períodos por dois observadores previamente calibrados (kappa 0,96) e sem conhecimento dos grupos experimentais. O exame histológico mostrou que todos os materiais provocaram reação inflamatória moderada aos 7 dias que regrediu com o tempo. A maior resposta inflamatória do tecido foi observada aos 7 dias, nos tubos preenchidos com pasta de Óxido de Zinco e Eugenol com Iodofórmio. Os tubos com MTA Fillapex apresentaram algumas células gigantes, macrófagos e linfócitos após 7 dias. Aos 15 dias, a presença de fibroblastos e fibras de colágenas foi observada, indicando processo de cicatrização do tecido. Os tubos com o cimento Portland mostraram resultados semelhantes aos observados no grupo MTA Fillapex. Aos 15 dias, a reação inflamatória apresentada foi praticamente ausente, com muitas fibras colágenas, indicando cicatrização normal do tecido. A análise estatística mostrou diferença estatisticamente significante entre o grupo de cimento Portland (15 dias) e óxido de zinco eugenol com Iodofórmio (7 dias) (p<0,05). Nos outros grupos não houve diferença estatística significante. MTA Fillapex e cimento Portland são mais biocompatíveis do que os outros cimentos testados

    A high-throughput cloning system for reverse genetics in Trypanosoma cruzi

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    <p>Abstract</p> <p>Background</p> <p>The three trypanosomatids pathogenic to men, <it>Trypanosoma cruzi</it>, <it>Trypanosoma brucei </it>and <it>Leishmania major</it>, are etiological agents of Chagas disease, African sleeping sickness and cutaneous leishmaniasis, respectively. The complete sequencing of these trypanosomatid genomes represented a breakthrough in the understanding of these organisms. Genome sequencing is a step towards solving the parasite biology puzzle, as there are a high percentage of genes encoding proteins without functional annotation. Also, technical limitations in protein expression in heterologous systems reinforce the evident need for the development of a high-throughput reverse genetics platform. Ideally, such platform would lead to efficient cloning and compatibility with various approaches. Thus, we aimed to construct a highly efficient cloning platform compatible with plasmid vectors that are suitable for various approaches.</p> <p>Results</p> <p>We constructed a platform with a flexible structure allowing the exchange of various elements, such as promoters, fusion tags, intergenic regions or resistance markers. This platform is based on Gateway<sup>® </sup>technology, to ensure a fast and efficient cloning system. We obtained plasmid vectors carrying genes for fluorescent proteins (green, cyan or yellow), and sequences for the <it>c-myc </it>epitope, and tandem affinity purification or polyhistidine tags. The vectors were verified by successful subcellular localization of two previously characterized proteins (<it>Tc</it>Rab7 and PAR 2) and a putative centrin. For the tandem affinity purification tag, the purification of two protein complexes (ribosome and proteasome) was performed.</p> <p>Conclusions</p> <p>We constructed plasmids with an efficient cloning system and suitable for use across various applications, such as protein localization and co-localization, protein partner identification and protein expression. This platform also allows vector customization, as the vectors were constructed to enable easy exchange of its elements. The development of this high-throughput platform is a step closer towards large-scale trypanosome applications and initiatives.</p
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