777 research outputs found

    Enzymatic degradation of starch thermoplastic blends using samples of different thickness

    Get PDF
    The material studied was a thermoplastic blend of corn starch with a poly(ethylene-vinyl alcohol) copolymer, SEVA-C. The influence of both the material’s exposed surface and enzyme concentration on degradation kinetics was studied. As α-amylase is present in the blood plasma, experiments were performed, varying the material thickness and the α-amylase between 50 and 100 units/l, at 37°C, lasting up to 90 days. Four different batches using SEVA-C and starch samples of different thickness were performed. The positive correlation between degradation rate and the exposed material surface was confirmed, since thin films with larger exposed surfaces were degraded faster than thick square plates having the same total mass. The degradation extent depends on the total amount of amorphous starch present in the formulation rather than on the amount of enzyme used and the minimum thickness to ensure maximum degradation was estimated to be close to 0.25 mm

    LA EVOLUCIÓN DE LAS PERSPECTIVAS DE MEDICIÓN DE LA POBREZA

    Get PDF
    This essay refers to the measurement of poverty in the one-dimensional perspective, based on the income, and the conceptual developments that made possible the structuring of a look multidimensional interpretation of socioeconomic phenomena related to deprivation, mainly in the perspective proposed by Amartya Sen, the Approach of Capacities, split into the Human Development Index (HDI) and the Poverty Index Multidimensional (IPM).Este ensayo se refiere a medición de la pobreza en la perspectiva unidimensional, basada en el ingreso, y las evoluciones conceptuales que viabilizaron la estructuración de una mirada multidimensional de interpretación de los fenómenos socioeconómicos relacionados con la privación, principalmente en la perspectiva propuesta por Amartya Sen, el Enfoque de las Capacidades, desdoblado en el Índice de Desarrollo Humano (IDH) y en el Índice de Pobreza Multidimensional (IPM)

    Equilibrium of Global Amphibian Species Distributions with Climate

    Get PDF
    A common assumption in bioclimatic envelope modeling is that species distributions are in equilibrium with contemporary climate. A number of studies have measured departures from equilibrium in species distributions in particular regions, but such investigations were never carried out for a complete lineage across its entire distribution. We measure departures of equilibrium with contemporary climate for the distributions of the world amphibian species. Specifically, we fitted bioclimatic envelopes for 5544 species using three presence-only models. We then measured the proportion of the modeled envelope that is currently occupied by the species, as a metric of equilibrium of species distributions with climate. The assumption was that the greater the difference between modeled bioclimatic envelope and the occupied distribution, the greater the likelihood that species distribution would not be at equilibrium with contemporary climate. On average, amphibians occupied 30% to 57% of their potential distributions. Although patterns differed across regions, there were no significant differences among lineages. Species in the Neotropic, Afrotropics, Indo-Malay, and Palaearctic occupied a smaller proportion of their potential distributions than species in the Nearctic, Madagascar, and Australasia. We acknowledge that our models underestimate non equilibrium, and discuss potential reasons for the observed patterns. From a modeling perspective our results support the view that at global scale bioclimatic envelope models might perform similarly across lineages but differently across regions

    Proposta de aplicação da metodologia da Manutenção Centrada em Confiabilidade para uma Recuperadora de Minério Tipo Ponte em uma mineradora / Aplication proposal of the Reliability-Centered Maintenance methodology for a Bridge-Type Bucket Wheel reclaimer in a mining

    Get PDF
    Esse trabalho propõe atividades baseadas na metodologia da Manutenção Centrada na Confiabilidade (MCC) para uma máquina Recuperadora de Minério do Tipo Ponte, a qual opera em uma grande mineradora multinacional. Foram levantados o histórico de produção e de falhas do ativo em um período de 10 meses, em que se percebe a baixa confiabilidade da máquina em cumprir suas funções principais, pois não foram cumpridas as metas de produção orçadas para o período e, também, porque ocorreram diversos eventos de parada não programada para manutenção corretiva. Assim, com envolvimento de profissionais de diversos setores (engenharia, operação, manutenção e inspeção mecânica), foi realizado um estudo detalhado de falhas com a ferramenta FMEA (Failure Modes and Effects Analysis). Por conseguinte, foram priorizados os modos de falhas mais críticos para, no final, se propor soluções que mitiguem ou amenizem os problemas encontrados, atuando sempre nas causas fundamentais das falhas

    Fracturing ranked surfaces

    Get PDF
    Discretized landscapes can be mapped onto ranked surfaces, where every element (site or bond) has a unique rank associated with its corresponding relative height. By sequentially allocating these elements according to their ranks and systematically preventing the occupation of bridges, namely elements that, if occupied, would provide global connectivity, we disclose that bridges hide a new tricritical point at an occupation fraction p=pcp=p_{c}, where pcp_{c} is the percolation threshold of random percolation. For any value of pp in the interval pc<p1p_{c}< p \leq 1, our results show that the set of bridges has a fractal dimension dBB1.22d_{BB} \approx 1.22 in two dimensions. In the limit p1p \rightarrow 1, a self-similar fracture is revealed as a singly connected line that divides the system in two domains. We then unveil how several seemingly unrelated physical models tumble into the same universality class and also present results for higher dimensions

    Um grande surto de Legionella ausente do debate público

    Get PDF
    The Legionnaires’ disease outbreak that hit Portugal in November 2014 was the third largest worldwide and was declared a “great public health emergency”. Nonetheless, the Portuguese outbreak, despite killing 12 people and infecting 375 others did not promote extensive media coverage, nor did it make it into the political debate. We conducted a quantitative analysis of 83 news pieces on Legionella published in four national newspapers, and interviewed the journalists who covered this outbreak. The communication process was controlled by a small group of official sources and the outbreak was pushed away from news lineups due to two political scandals. The production of another news wave made the outbreak’s news wave to break prematurely.O surto de Legionella que atingiu Portugal em novembro de 2014 foi o terceiro maior em nível mundial, constituindo “uma grande emergência de saúde pública”. Ainda assim, o surto português não promoveu uma longa cobertura mediática, apesar das 12 mortes e 375 pessoas infetadas. Nem entrou no debate político. Fizemos uma análise quantitativa das 83 notícias sobre Legionella publicadas em quatro jornais nacionais, e conduzimos entrevistas com os jornalistas que cobriram este surto. O processo comunicativo foi controlado por um pequeno grupo de fontes oficiais, e o surto foi rapidamente afastado dos alinhamentos noticiosos, sendo substituído por dois escândalos políticos. A produção de outra onda noticiosa fez com que a onda noticiosa do surto de Legionella se quebrasse prematuramente.(undefined)info:eu-repo/semantics/publishedVersio

    Sarcopenia and risk of malnutrition as risk factors for complications from COVID-19

    Get PDF
    Objetivo: Este estudo teve como objetivo associar o risco nutricional e de sarcopenia com desfechos clínicos em pacientes idosos com COVID-19. Métodos: Trata-se de um estudo de coorte retrospectivo longitudinal. Idosos hospitalizados com diagnóstico de COVID-19 foram incluídos no estudo. O risco nutricional foi avaliado usando o Malnutrition Universal Screening Tool (MUST) e o risco de sarcopenia foi avaliado usando o SARC-F. As associações foram avaliadas por modelos logísticos multivariados. Resultados: No total, 127 pacientes (média de idade: 71,25 ±8,06 anos) foram acompanhados até o desfecho clínico. Risco de sarcopenia foi diagnosticado em 63,8% da amostra, enquanto risco nutricional foi observado em 72% deles. Além disso, 48,8% da amostra necessitoude internação em unidade de terapia intensiva (UTI), 38,6% necessitaram ventilação mecânica e 32,3% foram a óbito. Idosos com risco de sarcopenia tiveram maior chance de internação em UTI (OR: 5,62; IC 95%: 2,2-14,3), necessidade de ventilação mecânica (OR: 4,0; IC 95%: 1,5-10,2) e óbito (OR: 5,06; IC 95%: 1,7-14,2). O risco de desnutrição avaliado pelo MUST foi um importante fator de risco para óbito (OR = 30,15; IC 95%: 3,6-245,8; p&lt;0,01). Conclusão: O risco de sarcopenia foi fator de risco para óbito, internação em UTI e ventilação mecânica,enquanto o risco nutricional foi fator de risco para óbito.Purpose: This study aimed to associate nutritional and sarcopenia risk with clinical outcomes in elderly patients with COVID-19. Methods: This is a longitudinal retrospective cohort study. Hospitalized elderly individuals diagnosed with COVID-19 were included in the study. Nutritional risk was assessed using the Malnutrition Universal Screening Tool (MUST), and Sarcopenia risk was assessed using the SARC-F. Associations were assessed throughmultivariable logistic models. Results: In total, 127 patients (mean age: 71.25 ±8.06 years) were followed up until the clinical outcome. Sarcopenia risk was diagnosed in 63.8% of the sample, whereas nutritional risk was observed in 72%. Hospitalization in the intensive care unit (ICU) was required in 48.8% of the sample, 38.6% required mechanicalventilation, and 32.3% died. Elderly individuals with sarcopenia risk were more likely to be hospitalized inICUs (OR: 5.62; 95%CI: 2.2-14.3), require mechanical ventilation (OR: 4.0; 95% CI: 1.5-10.2), and die (OR: 5.06; 95% CI: 1.7-14.2). The risk of malnutrition assessed through MUST was an important risk factor for death (OR = 30.15; 95% CI: 3.6-245.8; p&lt;0.01). Conclusion: Sarcopenia risk was a risk factor for death, hospitalization in ICU, and mechanical ventilation, while nutritional risk was a risk factor for death

    Rizo tomia e discectomia endoscópica no tratamento da dor lombar crônica e radiculopatia aguda na síndrome da pessoa rígida- relato de caso

    Get PDF
    Introduction: Stiff Person Syndrome (SPS) is a rare neurological disorder, first described in 1956 by Moersch and Woltman. The clinical picture has an insidious onset of classic findings of episodic painful spasms, hyperreflexia, axial muscle stiffness, progressing slowly to the proximal limb muscles. Painful hyperlordosis due to lumbar spine stiffness is a diagnostic characteristic of SPS. CASE REPORT: Male, 69 years old, with SPS for 40 years, referred by the neurologist to the spine surgeon because of failure to conservative management of chronic low back pain, progressively acute leg and gait impairment.&nbsp; Physical examination is difficult to perform in SPS because it triggers spasms. MRI presented zygoapophyseal joint, intervertebral discs and muscle degeneration, including a L4L5 cranial migrated herniated disc. Once there were no other effective ways to manage his axial and radicular pain, it was decided to perform percutaneous transforaminal endoscopic discectomy for L4L5 decompression, L3 to S1 dorsal ganglion root medial branch ablative radiofrequency rhizotomy to relieve facet pain and L2 dorsal sensory ganglion pulsed radiofrequency rhizotomy for modulation of chronic low back pain. One year postoperative follow up, the patient has showed improvement in the VAS and SF-36. CONCLUSION: Chronic pain reported by a patient must be addressed in the biological, psychological and social dimensions. Understanding the multidimensionality of the factors involved with pain allows planning less aggressive and highly efficient strategies in uncommon and off label patients, as in the case of SPS.Introdução: A síndrome da pessoa rígida (SPR) é um distúrbio neurológico raro, descrito pela primeira vez em 1956 por Moersch e Woltman. O quadro clínico apresenta início insidioso de achados clássicos de espasmos dolorosos episódicos, hiperreflexia, rigidez muscular axial, progredindo lentamente para os músculos proximais dos membros. A hiperlordose dolorosa devido à rigidez da coluna lombar é uma característica diagnóstica do SPS. RELATO DO CASO: Homem, 69 anos, com SPS há 40 anos, encaminhado pelo neurologista ao cirurgião de coluna por falha no manejo conservador da lombalgia crônica, dor radicular progressivo na perna e alteração da marcha. O exame físico é difícil de realizar na SPR porque desencadeia espasmos. A ressonância magnética apresentou degeneração nas articulações zigapofisárias, nos discos intervertebrais e muscular, incluindo hérnia discal L4L5 com migração cranial. Uma vez que não havia outras maneiras eficazes de gerenciar sua dor axial e radicular, foi decidido realizar discectomia endoscópica transforaminal percutânea para descompressão de L4L5, rizotomia de radiofrequência ablativa do ramo medial do gânglio dorsal de L3 a S1 para aliviar a dor facetaria e rizotomia de radiofrequência pulsada do gânglio sensitivo dorsal L2 para modulação da dor lombar crônica. Após um ano de pós-operatório, o paciente apresentou melhora na EVA e no SF-36. CONCLUSÃO: A dor crônica relatada pelo paciente deve ser tratada nas dimensões biológica, psicológica e social. Compreender a multidimensionalidade dos fatores envolvidos com a dor permite planejar estratégias menos agressivas e altamente eficientes em pacientes incomuns e off label, como no caso do SPS

    The effectiveness of constraint-led training on skill development in interceptive sports: a systematic review (Clark, McEwan and Christie) – a commentary

    Get PDF
    Clark, McEwan and Christie's systematic review1 offers a timely examination of current literature assessing effects of a constraints-led approach (CLA) to training on ‘technical and cognitive skill in sport’, in comparison to traditional training methods. They concluded that, currently, there is strong evidence to advocate for the effects of training interventions that espouse benefits of constraints-led training on acquiring skill in interceptive actions. Clark, McEwan and Christie reported that 18 studies satisfied their proposed inclusion criteria and, of these studies, 77% provided evidence of the effectiveness of the CLA. Consequently, Clark, McEwan and Christie argued that a ‘the implementation of the constraints-led approach within interceptive sport can be advocated’ (p. 17). This is a revealing insight, which supports their claims that this finding ‘provides the opportunity for researchers to collect more compelling evidence to answer the question: “Does constraint-led training assist with the development of technical skills within interceptive sport?”’. While we endorse their call for more empirical evidence on the effectiveness of a CLA to practice and training design, we qualify it by highlighting some limitations of Clark, McEwan and Christie's systematic review

    Comparative serology techniques for the diagnosis of Trypanosoma cruzi infection in a rural population from the state of Querétaro, Mexico

    Get PDF
    Immunological diagnostic methods for Trypanosoma cruzi depend specifically on the presence of antibodies and parasitological methods lack sensitivity during the chronic and “indeterminate” stages of the disease. This study performed a serological survey of 1,033 subjects from 52 rural communities in 12 of the 18 municipalities in the state of Querétaro, Mexico. We detected anti-T. cruzi antibodies using the following tests: indirect haemagglutination assay (IHA), indirect immunofluorescence assay (IFA), ELISA and recombinant ELISA (rELISA). We also performed Western blot (WB) analysis using iron superoxide dismutase (FeSOD), a detoxifying enzyme excreted by the parasite, as the antigen. Positive test results were distributed as follows: ELISA 8%, rELISA 6.2%, IFA and IHA 5.4% in both cases and FeSOD 8%. A comparative study of the five tests was undertaken. Sensitivity levels, specificity, positive and negative predictive values, concordance percentage and kappa index were considered. Living with animals, trips to other communities, gender, age, type of housing and symptomatology at the time of the survey were statistically analysed using SPSS software v.11.5. Detection of the FeSOD enzyme that was secreted by the parasite and used as an antigenic fraction in WBs showed a 100% correlation with traditional ELISA tests
    corecore