248 research outputs found

    Caracterização do Engaço da Uva e Avaliação do seu Potencial como Matéria‐Prima Lenhocelulósica

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    Resumo O presente estudo avalia a composição química detalhada do engaço da uva de modo a encontrar novas formas para a sua valorização. O engaço da uva é um subproduto vinícola de origem lenhocelulósica, com 30-31% de celulose, 21% de hemicelulose, 17-18% de lenhina, 15-16% de taninos e cerca de 6,0% de proteínas. A análise dos monossacarídeos mostrou que, a seguir à celulose, a xilana é o segundo polissacarídeo mais abundante no engaço (ca. 12%). A celulose foi isolada pelo método Kürscher e Hoffer e foi caracterizada por difração de raios-X (DRX). Esta análise revelou a existência de uma célula unitária típica de celulose I com um elevado grau de cristalinidade (ca. 75%). Também foi possível verificar uma elevada abundância de compostos extratáveis em água (ca. 24%), atribuídos principalmente a sais inorgânicos solúveis, taninos hidrolisáveis e pectinas. A lenhina Klason foi caracterizada por espectroscopia de infravermelho e espectroscopia de ressonância magnética tendo-se verificado tratar-se de uma lenhina do tipo HGS, com predominância de unidades guaiacilo.Abstract The present study evaluates the detailed chemical composition of grape stalks to find new forms of recovery. Grape stalk is a by-product from winemaking process of lignocellulosic source with 30-31% cellulose, 21% hemicellulose, 17-18% lignin, 15-16% tannin and about 6.0% protein. Analysis of monosaccharides showed that, after cellulose, the xylan is the second most abundant polysaccharide in stalks (ca. 12%). Cellulose was isolated by the Kürscher and Hoffer method and was characterized by X-ray diffraction (XRD). This analysis revealed the existence of a typical unit cell of cellulose I with a high degree of crystallinity (ca. 75%). It was also observed a high abundance of water extractable compounds (ca. 24%), attributed to mainly soluble inorganic salts, hydrolysable tannins and pectins. Klason Lignin was characterized by infrared spectroscopy and magnetic resonance spectroscopy and it was found that this is a HGS lignin-type, predominantly with guaiacyl units

    O auditor e a deteção de fraude: uma revisão da literatura

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    mestrado em Contabilidade - AuditoriaEm sociedades cada vez mais informadas e exigentes, a fraude torna-se cada vez menos tolerada, não obstante a ideia de a mesma estar cada vez mais presente. Paradoxalmente, trata-se de um problema de resolução praticamente impossível por estar associado à condição humana, mas que poderá ser minimizado através de ações eficazes e tempestivas. A fraude pode revestir as mais diversas formas e envolver os mais diversos agentes, podendo estes fazer parte da organização, quer pertencendo à gestão de topo quer exercendo as funções mais básicas, ou serem externos à mesma (clientes, fornecedores, etc.). A fraude é frequentemente tipificada em corrupção, apropriação indevida de ativos e fraude de demonstrações financeiras. Qualquer um dos tipos de fraude é influenciado por um ou vários fatores (sociais, económicos, etc.) que conduz o indivíduo à execução do ato. Os indivíduos que cometem este tipo de atos fraudulentos têm atitudes que indicam ao auditor a possibilidade de ocorrência de algo suspeito, os denominados red flags. No âmbito da presente dissertação procurou-se identificar o papel do auditor na deteção de fraudes e que abordagem aplicar nas diferentes situações. Com a análise dos estudos empíricos sobre a aplicação e a apresentação das diferentes ferramentas que auxiliam o auditor na análise dos dados das empresas, identificaram-se como mais eficazes e de grande utilidade para os auditores na deteção de fraude de demonstrações financeiras as técnicas das redes neurais, o mapa auto-organizado, o modelo de Beneish, a lei de Benford, as redes Bayesianas, a árvore de decisão, a análise de conteúdo, o clustering e a regressão logística.In increasingly informed and demanding societies, fraud becomes less and less tolerated, despite the idea that it is increasingly present. Paradoxically, it is a problem of resolution practically impossible because it is associated with the human condition, but can be minimized through effective and timely actions. Fraud can take a variety of forms and involve a wide range of agents, who may be part of the organization, whether they belong to top management or perform the most basic functions, or be external to them (clients, suppliers, etc.). Fraud is often typified in corruption, misappropriation of assets, and fraud financial statements. Either type of fraud is influenced by one or several factors (social, economic, etc.) that leads the individual to perform the act. Individuals who commits this type of fraudulent act have attitudes that indicate to the auditor the possibility of occurrence of something suspicious, the red flags. In the scope of this dissertation, the paper sought to identify the role of the auditor in the detection of fraud and what approach to apply in different situations. With the analysis of the empirical studies on the application and presentation of the different tools that assist the auditor in the analysis of company data, they have identified themselves as more effective and of great use for the auditors in the detection of fraud of financial statements, neural networks techniques, self-organized map, Beneish model, Benford´s Law, Bayesian networks, decision tree, content analysis, clustering and logistic regression

    Physico-chemical surface characterization of a bacterial population isolated from a milking machine

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    The hydrophobicity of 26 species of bacteria representative of the main genera isolated from a rubber short milk tube, which is a constituent of a cluster from a milking machine, was determined. The materials forming the cluster namely rubber, stainless steel (SS) 316, stainless steel (SS) 304, glass and polymethylmethacrylate (PMMA) were also assayed in terms of hydrophobicity. In relation with the hydrophobicity of bacteria, all the strains of Lactobacillus lactis lactis as well as of Enterococcus faecalis are hydrophobic. Concerning Pseudomonas aeruginosa and Staphylococcus sciuri, some are hydrophobic and others are hydrophilic. All the materials are hydrophobic, being rubber, SS 316 and SS 304 the most hydrophobic surfaces while glass is the less hydrophobic. The free energy of adhesion between the bacteria and the materials in aqueous medium was calculated and used to predict which material of the cluster has a higher ability for biofilm formation and by this way contribute for milk contamination due to the release of bacteria from the deposit. For all the situations studied, adhesion is thermodynamically favourable to SS 316, SS 304 and rubber and less favourable to PMMA and glass.Ministério da Agricultura, do Desenvolvimento Rural e das Pescas (INIAP) - Project AGRO 205

    Assist-as-needed impedance control strategy for a wearable ankle robotic orthosis

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    The use of robots in rehabilitation attempts an effective, compliant, and time-efficient gait recovery while adapting the assistance to the user's needs. Assist-as-needed strategies (AAN), such as adaptive impedance control, have been reported as prominent strategies to enable this recovery effects. This study proposes an interaction-based assist-as-needed impedance control strategy for an ankle robotic orthosis that adapts the robotic assistance by changing the Human-Robot interaction stiffness. The adaptability of the interaction stiffness allows the real-time passage from passive assistance to an active one, approaching AAN gait training. The interaction stiffness was successfully estimated by linear regression of the Human-Robot interaction torque vs angle trajectory curve. From the validation with seven able-bodied subjects, we verified the suitability of this adaptive impedance control for a more compliant, natural, and comfortable motion than the trajectory tracking control. Moreover, the proposed strategy considers the users' motion intention and encourages them to interact closely with the robotic device while guiding their ankle trajectory according to desired trajectories. These achievements contribute to AAN gait training.This work has been supported by the FEDER Funds through the Programa Operacional Regional do Norte and national funds from Fundação para a Ciência e Tecnologia with the project SmartOs under Grant NORTE-01-0145-FEDER-030386, and through the COMPETE 2020—Programa Operacional Competitividade e Internacionalização (POCI)—with the Reference Project under Grant POCI-01-0145-FEDER-006941

    Monitoring cell detachment by surfactants in a parallel plate flow chamber

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    The efficacy of the surfactants SDS and CTAB in detaching P. fluorescens from glass surface was evaluated in a parallel plate flow chamber. This device enables “in situ” determinations of cells detachment following the application of surfactants under well controlled hydrodynamic conditions. The results showed that SDS was able to remove almost all adhering bacteria in a short period of time, whereas CTAB did not promote much cell desorption. On the contrary, this surfactant increased the adhesion strength between cells and glass. Both surfactants promoted different alterations of cell surface properties, which explains their dissimilar effectiveness as cleansing agents.programme SAPIEN

    Non-invasive Pneumococcal pneumonia in Portugal : serotype distribution and antimicrobial resistance

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    Copyright: © 2014 Horácio et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.There is limited information on the serotypes causing non-invasive pneumococcal pneumonia (NIPP). Our aim was to characterize pneumococci causing NIPP in adults to determine recent changes in serotype prevalence, the potential coverage of pneumococcal vaccines and changes in antimicrobial resistance. Serotypes and antimicrobial susceptibility profiles of a sample of 1300 isolates recovered from adult patients (≥18 yrs) between 1999 and 2011 (13 years) were determined. Serotype 3 was the most frequent cause of NIPP accounting for 18% of the isolates. The other most common serotypes were 11A (7%), 19F (7%), 19A (5%), 14 (4%), 22F (4%), 23F (4%) and 9N (4%). Between 1999 and 2011, there were significant changes in the proportion of isolates expressing vaccine serotypes, with a steady decline of the serotypes included in the 7-valent conjugate vaccine from 31% (1999-2003) to 11% (2011) (P<0.001). Taking together the most recent study years (2009-2011), the potential coverage of the 13-valent conjugate vaccine was 44% and of the 23-valent polysaccharide vaccine was 66%. While erythromycin resistance increased from 8% in 1999-2003 to 18% in 2011 (P<0.001), no significant trend was identified for penicillin non-susceptibility, which had an average value of 18.5%. The serotype distribution found in this study for NIPP was very different from the one previously described for IPD, with only two serotypes in common to the ones responsible for half of each presentation in 2009-2011 - serotypes 3 and 19A. In spite of these differences, the overall prevalence of resistant isolates was similar in NIPP and in IPD.A.N. Horácio was supported by grant SFRH/BD/81205/2011, from Fundação para a Ciência e Tecnologia, Portugal. This work was partially supported by Fundação para a Ciência e Tecnologia, Portugal (PTDC/DTP-EPI/1759/2012) and unrestricted research grants from Pfizer and GlaxoSmithKline.info:eu-repo/semantics/publishedVersio

    Serotype 3 Remains the Leading Cause of Invasive Pneumococcal Disease in Adults in Portugal (2012-2014) Despite Continued Reductions in Other 13-Valent Conjugate Vaccine Serotypes

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    Since 2010 the 13-valent pneumococcal conjugate vaccine (PCV13) replaced the 7-valent vaccine (PCV7) as the leading pneumococcal vaccine used in children through the private sector. Although, neither of the PCVs were used significantly in adults, changes in adult invasive pneumococcal disease (IPD) were expected due to herd protection. We characterized n = 1163 isolates recovered from IPD in adults in 2012-2014 with the goal of documenting possible changes in serotype prevalence and antimicrobial resistance. Among the 54 different serotypes detected, the most frequent, accounting for half of all IPD, were serotypes: 3 (14%), 8 (11%), 19A (7%), 22F (7%), 14 (6%), and 7F (5%). The proportion of IPD caused by PCV7 serotypes remained stable during the study period (14%), but was smaller than in the previous period (19% in 2009-2011, p = 0.003). The proportion of IPD caused by PCV13 serotypes decreased from 51% in 2012 to 38% in 2014 (p < 0.001), mainly due to decreases in serotypes 7F and 19A. However, PCV13 serotype 3 remained relatively stable and the most frequent cause of adult IPD. Non-PCV13 serotypes continued the increase initiated in the late post-PCV7 period, with serotypes 8 and 22F being the most important emerging serotypes. Serotype 15A increased in 2012-2014 (0.7% to 3.5%, p = 0.011) and was strongly associated with antimicrobial resistance. However, the decreases in resistant isolates among serotypes 14 and 19A led to an overall decrease in penicillin non-susceptibility (from 17 to 13%, p = 0.174) and erythromycin resistance (from 19 to 13%, p = 0.034). Introduction of PCV13 in the NIP for children, as well as its availability for adults may further alter the serotypes causing IPD in adults in Portugal and lead to changes in the proportion of resistant isolates.info:eu-repo/semantics/publishedVersio

    Deep learning-based energy expenditure estimation in assisted and non-assisted gait using inertial, EMG, and heart rate wearable sensors

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    Energy expenditure is a key rehabilitation outcome and is starting to be used in robotics-based rehabilitation through human-in-the-loop control to tailor robot assistance towards reducing patients’ energy effort. However, it is usually assessed by indirect calorimetry which entails a certain degree of invasiveness and provides delayed data, which is not suitable for controlling robotic devices. This work proposes a deep learning-based tool for steady-state energy expenditure estimation based on more ergonomic sensors than indirect calorimetry. The study innovates by estimating the energy expenditure in assisted and non-assisted conditions and in slow gait speeds similarly to impaired subjects. This work explores and benchmarks the long short-term memory (LSTM) and convolutional neural network (CNN) as deep learning regressors. As inputs, we fused inertial data, electromyography, and heart rate signals measured by on-body sensors from eight healthy volunteers walking with and without assistance from an ankle-foot exoskeleton at 0.22, 0.33, and 0.44 m/s. LSTM and CNN were compared against indirect calorimetry using a leave-one-subject-out cross-validation technique. Results showed the suitability of this tool, especially CNN, that demonstrated root-mean-squared errors of 0.36 W/kg and high correlation (ρ > 0.85) between target and estimation (R¯2 = 0.79). CNN was able to discriminate the energy expenditure between assisted and non-assisted gait, basal, and walking energy expenditure, throughout three slow gait speeds. CNN regressor driven by kinematic and physiological data was shown to be a more ergonomic technique for estimating the energy expenditure, contributing to the clinical assessment in slow and robotic-assisted gait and future research concerning human-in-the-loop control.This work has been supported in part by the FEDER Funds through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI) and P2020 with the Reference Project SmartOs Grant POCI-01-0247-FEDER-039868, and by FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020, under the FCT scholarship with reference 2020.05708.BD, and under the Stimulus of Scientific Employment with the grant 2020.03393.CEECIND

    Low Serum Levels of DKK2 Predict Incident Low-Impact Fracture in Older Women

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    There are currently no robust noninvasive markers of fragility fractures. Secreted frizzled related protein-1 (sFRP-1), dickkopf-related protein 1 (DKK1) and DKK2, and sclerostin (SOST) inhibit Wnt signaling and interfere with osteoblast-mediated bone formation. We evaluated associations of serum levels of sFRP-1, DKK1, DKK2, and SOST with incident low-impact fracture and BMD in 828 women aged ≥65 years from EpiDoC, a longitudinal population-based cohort. A structured questionnaire during a baseline clinical appointment assessed prevalent fragility fractures and clinical risk factors (CRFs) for fracture. Blood was collected to measure serum levels of bone turnover markers and Wnt regulators. Lumbar spine and hip BMD were determined by DXA scanning. Follow-up assessment was performed through a phone interview; incident fragility fracture was defined by any new self-reported low-impact fracture. Multivariate Cox proportional hazard models were used to analyze fracture risk adjusted for CRFs and BMD. During a mean follow-up of 2.3 ± 1.0 years, 62 low-impact fractures were sustained in 58 women. A low serum DKK2 level (per 1 SD decrease) was associated with a 1.5-fold increase in fracture risk independently of BMD and CRFs. Women in the two lowest DKK2 quartiles had a fracture incidence rate of 32 per 1000 person-years, whereas women in the two highest quartiles had 14 fragility fractures per 1000 person-years. A high serum sFRP1 level was associated with a 1.6-fold increase in fracture risk adjusted for CRFs, but not independently of BMD. Serum levels of SOST (r = 0.191; p = 0.0025) and DKK1(r = -0.1725; p = 0.011) were correlated with hip BMD, but not with incident fragility fracture. These results indicate that serum DKK2 and sFRP1 may predict low-impact fracture. The low number of incident fractures recorded is a limitation and serum levels of Wnt regulators should be further studied in other populations as potential noninvasive markers of fragility fractures. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.publishersversionpublishe

    Identifying a quick and efficient method of removing organic matter without damaging microplastic samples

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    Natural organic matter may confound the detection of microplastics, requiring a removal step. However, most available protocols are long and lack information on removal efficiency and polymer degradation. Thus, we have determined the digestion efficiency (%) for a pool of organic matter (algae, driftwood, feathers, fish muscle, paraffin, palm oil) for five digestion solutions, hydrogen peroxide (H2O2), hydrogen peroxide with iron catalyst (H2O2 + Fe), potassium hydroxide (KOH), nitric acid (HNO3), and sodium dodecyl sulphate (SDS), under two temperatures (room temperature at 25 °C, 50 °C) and two periods (1, 6 h). H2O2 + Fe and KOH at 50 °C for 1 h had the highest digestion efficiencies, of 65.9% and 58.3% respectively (mostly limited by driftwood and paraffin). Further testing revealed that H2O2 + Fe is more appropriate for plant material and KOH for animal tissue. Weight loss (%), Fourier transform infrared spectrometry and carbonyl index of 9 virgin and 6 weathered polymers (polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, cellulose acetate, nylon) revealed that only identification of cellulose acetate was hindered. Filters were also tested revealing that quartz and glass fibre filters are resistant to these protocols. Thus, a digestion protocol based on H2O2 + Fe or KOH at 50 °C for 1 h may be used on microplastic samples.publishe
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