Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Accuracy versus precision in boosted top tagging with the ATLAS detector

Abstract The identification of top quark decays where the top quark has a large momentum transverse to the beam axis, known as top tagging, is a crucial component in many measurements of Standard Model processes and searches for beyond the Standard Model physics at the Large Hadron Collider. Machine learning techniques have improved the performance of top tagging algorithms, but the size of the systematic uncertainties for all proposed algorithms has not been systematically studied. This paper presents the performance of several machine learning based top tagging algorithms on a dataset constructed from simulated proton-proton collision events measured with the ATLAS detector at √ s = 13 TeV. The systematic uncertainties associated with these algorithms are estimated through an approximate procedure that is not meant to be used in a physics analysis, but is appropriate for the level of precision required for this study. The most performant algorithms are found to have the largest uncertainties, motivating the development of methods to reduce these uncertainties without compromising performance. To enable such efforts in the wider scientific community, the datasets used in this paper are made publicly available.</jats:p

N-acetylcysteine counteracts adipose tissue macrophage infiltration and insulin resistance elicited by advanced glycated albumin in healthy rats

Background: Advanced glycation endproducts elicit inflammation. However, their role in adipocyte macrophage infiltration and in the development of insulin resistance, especially in the absence of the deleterious biochemical pathways that coexist in diabetes mellitus, remains unknown. We investigated the effect of chronic administration of advanced glycated albumin (AGE-albumin) in healthy rats, associated or not with N-acetylcysteine (NAC) treatment, on insulin sensitivity, adipose tissue transcriptome and macrophage infiltration and polarization. Methods: Male Wistar rats were intraperitoneally injected with control (C) or AGE-albumin alone, or, together with NAC in the drinking water. Biochemical parameters, lipid peroxidation, gene expression and protein contents were, respectively, determined by enzymatic techniques, reactive thiobarbituric acid substances, RT-qPCR and immunohistochemistry or immunoblot. Carboxymethyllysine (CML) and pyrraline (PYR) were determined by LC/mass spectrometry (LC-MS/MS) and ELISA. Results: CML and PYR were higher in AGE-albumin as compared to C. Food consumption, body weight, systolic blood pressure, plasma lipids, glucose, hepatic and renal function, adipose tissue relative weight and adipocyte number were similar among groups. In AGE-treated animals, insulin resistance, adipose macrophage infiltration and Col12a1 mRNA were increased with no changes in M1 and M2 phenotypes as compared to C-albumin-treated rats. Total GLUT4 content was reduced by AGE-albumin as compared to C-albumin. NAC improved insulin sensitivity, reduced urine TBARS, adipose macrophage number and Itgam and Mrc mRNA and increased Slc2a4 and Ppara. CD11b, CD206, Ager, Ddost, Cd36, Nfkb1, Il6, Tnf, Adipoq, Retn, Arg, and Il12 expressions were similar among groups. Conclusions: AGE-albumin sensitizes adipose tissue to inflammation due to macrophage infiltration and reduces GLUT4, contributing to insulin resistance in healthy rats. NAC antagonizes AGE-albumin and prevents insulin resistance. Therefore, it may be a useful tool in the prevention of AGE action on insulin resistance and long-term complications of DM

A produção de plosivas por crianças de três anos falantes do português brasileiro Infant voices: the production of plosives by three-year-olds

OBJETIVO: apresentar as características fonético-acústicas de produção das consoantes plosivas vozeadas e não-vozeadas por crianças de três anos. MÉTODOS: análise qualitativa baseada na inspeção das características fonético-acústicas de eventos fônicos ocorridos no intervalo de obstrução, na liberação da plosão e na transição para a vogal e análise quantitativa das medidas do Voice Onset Time (VOT), de três repetições das seis consoantes plosivas do Português Brasileiro (PB), por quatro crianças, sendo três meninos e uma menina, falantes nativos do PB, por meio de análise fonético-acústica, em espectrograma de banda larga. Os achados foram comparados com estimativas de valores para a faixa adulta de falante nativo do PB. RESULTADOS: as crianças apresentaram produções semelhantes às que são encontradas na fala adulta, tanto para as plosivas vozeadas como para as não-vozeadas, bilabiais, alveolares e velares. Apresentaram também plosivas vozeadas com interrupção de barra de sonoridade e ocorrência de VOT positivo, e qualidade diferenciada de burst. Para as não-vozeadas, ocorreram a presença da breathy vowel no período de obstrução das plosivas e a presença de aspiração no segmento correspondente ao VOT positivo, para os três pontos de articulação pesquisados. CONCLUSÃO: as diferenças encontradas na produção das plosivas vozeadas, quanto às características da barra de sonoridade e qualidade do burst, a presença da breathy vowel nas plosivas não-vozeadas e aspiração, caracterizam a produção das plosivas nessa faixa etária. A diversidade das medidas acústicas, verificada pelos valores dos desvios-padrão sugerem que as crianças realizaram diversas tentativas, com diferentes ajustes para produzir tais sons.<br>PURPOSE: to present the phonetic-acoustic features of the production of both voiced and voiceless plosives by three-year-old children. METHODS: qualitative analysis based on the inspection of phonetic-acoustic characteristics of phonic events occurring in the obstruction interval, in the burst, and in the transition to the vowel as well as quantitative analysis of the measures of the voice onset time (VOT), of three repetitions of the six plosive consonants of Brazilian Portuguese (BP) by four native-speaker children in the three-year-old age bracket, three boys and one girl, by means of an acoustic-phonetic analysis, in a wide-band spectrogram. The findings were compared to estimates of values for the adult group of native speakers of Brazilian Portuguese (BP). RESULTS: the children showed production of plosives with VOT similar to that of adult speech both for voiced and unvoiced plosives, bilabials, alveolars and velars. They also showed productions dissimilar to adults, such as voiced plosives with interruption of the voice bar and positive VOT, besides a particular quality of burst. As regards the unvoiced plosives, there were episodes of breathy vowel during obstruction as well as of aspiration in the segment corresponding to positive VOT, in the three articulation points under study. CONCLUSION: differences found in the production of voiced plosives as regards spectral features of the voice bar and burst quality as well as the occurrence of breathy vowel in unvoiced plosives along with aspiration, characterize the production of plosives in this age bracket. The diversity of acoustic measures, observed by the values of shunting line-standards, suggest that children made several attempts, with various degrees of adjustment, to produce such sounds