Mediana de dados não agrupados: a questão de ser pelo menos 50%

Com o presente trabalho temos como objetivo ilustrar exemplos que abrangem as diferentes situações que podem ocorrer no cálculo da mediana de uma coleção de dados. Pretendemos mostrar, com exemplos, as possíveis interpretações válidas de mediana que, de forma similar, podem ser extensíveis aos outros quartis. Com esses exemplos pretendemos discutir o eventual confronto entre a noção intuitiva de mediana e sua interpretação. Deste modo, esperamos contribuir para uma melhor compreensão de possíveis deduções, consequentes da interpretação de mediana, que por vezes causam alguma estranheza entre os estudantes, nomeadamente quando, por exemplo, existem observações repetidas e iguais à mediana numa coleção de dados

Measurement of gamma-ray production cross sections for nuclear reaction 31P(p,pγ1-0)31P

In order to implement a standard free PIGE analysis of phosphorus, the cross section of the reaction 31P(p,pγ1-0)31P, γ1-0=1266.1keV was measured for the proton energy range 2.6–4 MeV, with energy steps ranging from 1 keV on resonances to 10 keV off resonance. This data provides additional information in relation to previous works on this reaction, as a more detailed and extended (in energy) measurement was made. The results obtained in this work were compared within the common energy range with previous measurements. There is a fair agreement within the quoted uncertainties although a larger energy step was used by the other authors and some resonances were missed. Also, a validation was accomplished by introducing the measured excitation function in the ERYA code to calculate thick target phosphorus yields of Ca3(PO4)2 and comparing the calculated values with the corresponding measured yields and also with other thick target yields found in the literature. A good agreement was found.authorsversionpublishe

Effect of a sardine supplement on C-reactive protein in patients receiving hemodialysis

Objective - The study evaluated the effect of a canned sardine supplement in C-reactive protein (CRP) in patients on hemodialysis (HD) and the compliance and adherence to this supplement. Design - This was a quasi-experimental study: Participants with a serum CRP of 5 mg/dL or less volunteered to consume a sardine supplement or were maintained on the usual cheese/ham sandwich supplement. Setting - The study took place in two outpatient dialysis units in Lisbon, Portugal. Patients - The study comprised 63 patients receiving maintenance HD three times per week for at least 6 months and an initial CRP concentration of 5 mg/dL or less. Exclusion criteria included the presence of graft vascular access or history of cancer. Intervention - After a 4-week washout period, the nutritional intervention included a canned sardine sandwich for the case group (n = 31) and a cheese or ham sandwich for the control group (n = 32), to be ingested during each routine HD session, 3 times per week, for 8 weeks. Main outcome measure - Serum levels of high-sensitivity CRP were the outcome measure. Results - Only 65 patients from the invited 186 patients met the inclusion criteria and agreed to eat the sardine sandwich supplement three times per week and were involved in the study. A significant proportion of 48% (n = 31, case group) consumed the sardine sandwich supplement three times per week for 8 weeks, fulfilling the requirements and completing the study. The present investigation showed that a sardine sandwich supplement had no effect on CRP levels among patients on HD. However, when participants were stratified according to tertiles of CRP distribution values at baseline, a reduction in CRP levels was found for those in the higher tertile, being higher for the case group (P = .047). Although diabetic patients were excluded from the analysis (eight in the sardine supplementation group and seven in the control group) a significant CRP reduction was found (P = .034). Conclusion - Although a supplement of low-dose n-3 long-chain polyunsaturated fatty acids had no effect on the plasma high-sensitivity CRP of the supplemented group, a reduction in CRP levels was found when patients were stratified for tertiles of CRP (for the upper tertile) and diabetic status (for nondiabetic patients). These findings need to be further confirmed. This canned sardine supplement was accepted by an important proportion of patients, enhancing diet variety and contributing for a greater n-3 long-chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid intake

Quality of multiple choice questions in a numerical and statistical methods course

The quality control of written examination is very important in the teaching and learning process of any course. In educational assessment contexts, Item Response Theory (IRT) has been applied to measure the quality of a test in areas of knowledge like medicine, psychology, and social sciences, and its interest has been growing in other topics as well. Based on statistical models for the probability of an individual answering a question correctly, IRT can be addressed to measure examiners’ ability in an assessment test and to estimate difficulty and discrimination levels of each item in the test. In this work, IRT is applied to Numerical and Statistical Methods course to measure the quality of tests based on Multiple Choice Questions (MCQ). The present study focuses on three school years, namely 2015, 2016 and 2017, more specifically on the 1st semester of the 2nd year of the degree course. It has involved more than 300 students in each year, and it points out questions (also called items) from some chapters of the program that were evaluated through MCQ. Emphasis is given on the range of item difficulty and item discrimination parameters, estimated by IRT methodology, for each question in those exams. We show where each partial exam explores ability levels: at a passing point or at more demanding levels. After the application of IRT to each test, which was composed of eight questions, we got 48 item difficulty and item discrimination parameters. The application of standard boxplots shows few atypical responses from students in terms of extremal values of difficulty and discrimination, which corresponds to MCQ that deserve further attention. We have concluded that the vast majority of questions are well posed considering that they are designed to focus on the cut-off point (passing/not passing). A proposed reflection, about the learned benefits from ‘good’ outliers and possible causes for those ‘bad’ items, suggests future improvements to classes, study materials and exams.publishe

Two-step purification of epilactose produced by cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus

Epilactose is a functional sugar that can be produced from lactose using cellobiose 2-epimerase and it is considered a developing prebiotic. In that sense, the development of strategies to produce and purify epilactose is key for its wider use in the food industry. The aim of this work was to establish a food-grade purification strategy suitable to be scaled-up to an industrial level. Firstly, the epilactose was produced by enzymatic epimerization of lactose in a reaction catalyzed by the recombinant cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus produced by Saccharomyces cerevisiae. Then, to remove the unreacted lactose, a screening study was performed to find a suitable -galactosidase enzyme with high lactose hydrolysis capacity but low ability to convert the epilactose. The elimination of the generated monosaccharides was then attempted by microbial treatment using different microorganisms and using activated charcoal. The bakers yeast S. cerevisiae was proven to be the most suitable microorganism for glucose and galactose removal from the reaction mixture. Overall, an attractive and food-grade two-step process for epilactose recovery was established, resulting in a purity and yield of 87% and 76.4%, respectively. Additionally, the INFOGEST 2.0 static in vitro simulation of gastrointestinal food digestion was used, for the first time, to assess the resistance of epilactose (77% resistance) to the upper gastrointestinal tract conditions, reinforcing its potential to be used as prebiotic.BBC and JMF acknowledge their doctoral grants (SFRH/BD/ 132324/2017 and SFRH/BD/147286/2019, respectively) from the Portuguese Foundation of Science and Technology (FCT). This study was supported by FCT under the scope of the strategic funding of UIDB/ 04469/2020 unit.info:eu-repo/semantics/publishedVersio

Recombinant Saccharomyces cerevisiae as a microbial biocatalyst for the one-step production of prebiotic fructooligosaccharides

Fructooligosaccharides (FOS) are widely consumed prebiotics with proven beneficial effects on both human and animal health. As a result, alternative production processes with high-efficiency have been an increasing focus of interest by both academy and industry. In this work, a in vivo bioprocess approach was successfully developed for one-step production of FOS from sucrose fermentation by recombinant yeast. Saccharomyces cerevisiae YIL162W lacking the gene responsible for sucrose hydrolysis (suc2) was transformed to express the -fructofuranosidase (Ffase) INV gene from Schwanniomyces occidentalis (clone L196), and its mutated version containing a serine instead of a leucine at position 196 (clone S196), under the inducible GAL1 promotor. Clone S196 presented a 2.75-fold higher sucrolytic activity (22±3 U.mL-1), while clone L196 presented a higher efficiency towards FOS production, producing mainly 6-kestose (76±3 g.L-1) and 1-kestose (1.6±0.6 g.L- 1) after 24 h of fermentation at 30 °C and 200 rpm, in a medium containing 300 g/L of sucrose. Attending the potential of process simplification and cost-reduction, the Ffase INV gene was then expressed under the glyceraldehyde-3-phosphate dehydrogenase (GPD) constitutive promoter (clone GPD L196), resulting in a maximum FOS production of 61±4 g.L-1 ( 56±3 g.L-1 of 6-kestose and 5±31 of fructosylnystose) after 48 h of fermentation using 300 g/L of sucrose. Interestingly, the total amount of undesired glucose and fructose present in the media whenever the maximal FOS production was achieved, was 9 times lower with the GDP promoter (5.5±0.9 g.L-1). The present work demonstrates the high potential of this bioprocess approach for industrial production of prebiotic FOS in a single step. Nevertheless, there is still room for yield improvement in future work, namely through bioprocess optimization.FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit and the project FoSynBio (POCI-01-0145-FEDER-029549). The authors also acknowledge BioTecNorte operation (NORTE-01- 0145-FEDER-000004) and the project MultiBiorefinery (POCI-01-0145-FEDER-016403) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norteinfo:eu-repo/semantics/publishedVersio

Zymomonas mobilis: a promising microorganism for prebiotic production

Zymomonas mobilis (ZM) is an ethanologenic bacterium with outstanding characteristics which makes it an interesting chassis for the biotechnological production of prebiotics. Fructooligosaccharides (FOS) are promising prebiotics in the increasing market of functional food. In this work, a Box-Behnken design approach was used to optimize the medium composition and maximize the FOS content. Under optimal conditions, 45.3 g/L of FOS were obtained. Sucrose was the most significant variable; thus, its concentration was further increased to 350 g/L leading to a 1.13-fold enhance in FOS titer. Afterwards, a scale-up to bioreactor was performed resulting in a high yield, content and productivity of FOS (58 %, 156.5 g/L 4.8 g/L h). Furthermore, 45 g/L of sorbitol and 8 g/L of levan were also produced. After purification of the FOS mixture through an activated charcoal column, an in vitro model using human fecal inoculum was used to assess its prebiotic potential. The results suggest that the produced prebiotic mixture has potential to be used to improve the human health. The present work describes for the first time the production of a prebiotic mixture with ZM ZM4 in an in vivo single-step approach that has potential to be commercialized as functional food ingredient.João Rainha, Beatriz B. Cardoso and Daniela Gomes acknowledge their grants (UMINHO/BPD/4/2019, SFRH/BD/138325/2018, SFRH/BD/132324/2017, and SFRH/BD/04433/2020, respectively) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and the project FoSynBio (POCI-01-0145-FEDER-029549).info:eu-repo/semantics/publishedVersio

Agro-industrial wastes as alternative substrates for the production of prebiotic with Zymomonas mobilis

Fructooligosaccharides (FOS) are promising prebiotics in the relevant and increasing market of functional food. However, to achieve a more sustainable process, the industrial production of FOS should use cheap substrates. Zymomonas mobilis (ZM) has great potential for the production of FOS due to the presence of native enzymes (levansucrase) capable of metabolizing sucrose. In addition, ZM can use different carbon sources, such as molasses and sugarcane juice, which make the FOS production process cost-effective. In this study, sugarcane molasses (a potential replacement of sucrose) and corn step liquor (CSL) (a potential replacement of yeast extract (YE)), were used as nutrients for FOS production using ZM in an in vivo bioprocess approach. FOS production process from sucrose was first optimized and 52 g/L of FOS with a yield of 0.16 g/g was obtained. Afterwards, molasses and CSL were used as alternative nutrients. After studying different combinations of CSL and YE, the highest amount of FOS (54 g/L, with a yield of 0.18 g/g) was obtained with 12 g/L of CSL and 8 g/L of YE. In addition, 45 g/L of FOS were produced from molasses containing 200 g/L of sucrose, with a yield of 0.3 g/g. With this approach, it was possible to reduce around 5.5-times the cost associated with the FOS production medium. Moreover, this study proposed a sustainable process for the valorization of agro-industrial wastes contributing to the future Circular (Bio)Economy and the EU Green Deal.Cláudia Amorim, João Rainha, Beatriz B. Cardoso and Daniela Gomes acknowledge their grants (2020.0029.CEECIND, SFRH/BD/138325/2018, SFRH/BD/132324/2017 and SFRH/BD/04433/2020, respectively) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020.info:eu-repo/semantics/publishedVersio

Surtos de vírus Vaccinia-like nos Estados de São Paulo e Goiás, Brasil: detecção, isolamento e identificação viral

Since October 2001, the Adolfo Lutz Institute has been receiving vesicular fluids and scab specimens of patients from Paraíba Valley region in the São Paulo and Minas Gerais States and from São Patricio Valley, in the Goiás State. Epidemiological data suggested that the outbreaks were caused by Cowpox virus or Vaccinia virus. Most of the patients are dairy milkers that had vesiculo-pustular lesions on the hands, arms, forearms, and some of them, on the face. Virus particles with orthopoxvirus morphology were detected by direct electron microscopy (DEM) in samples of 49 (66.21%) patients of a total of 74 analyzed. Viruses were isolated in Vero cell culture and on chorioallantoic membrane (CAM) of embryonated chicken eggs. Among 21 samples submitted to PCR using primers for hemagglutinin (HA) gene, 19 were positive. Restriction digestion with TaqI resulted in four characteristic Vaccinia virus fragments. HA nucleotide sequences showed 99.9% similarity with Cantagalo virus, described as a strain of Vaccinia virus. The only difference observed was the substitution of one nucleotide in the position 616 leading to change in one amino acid of the protein in the position 206. The phylogenetic analysis showed that the isolates clustered together with Cantagalo virus, other Vaccinia strains and Rabbitpox virus.A partir de outubro de 2001, o Instituto Adolfo Lutz tem recebido amostras de líquido vesicular e crostas de lesões de pele de pacientes das regiões do Vale do Paraíba, Estado de São Paulo e do Vale do São Patricio, Estado de Goiás. Os dados clínicos e epidemiológicos sugeriam que os surtos poderiam ser causados por Cowpox virus ou Vaccinia virus. A maioria dos pacientes era ordenhadores que tinham lesões vesicopustulares nas mãos, braços, antebraços e alguns na face. A análise por microscopia eletrônica direta (MED) detectou partículas com morfologia de vírus do gênero Orthopoxvirus em amostras de 49 (66,21%) pacientes dos 74 analisados. Os vírus foram isolados em membrana corioalantóide (MCA) de ovo embrionado de galinha e em linhagem celular Vero com confirmação por MED e PCR. Das 21 amostras de lesões submetidas ao PCR utilizando iniciadores para o gene da hemaglutinina (HA), 19 foram positivas. A digestão por enzima de restrição TaqI resultou em quatro fragmentos característicos de Vaccinia virus. A análise nucleotídica do seqüenciamento revelou que esses vírus apresentam 99,9% de similaridade com o Cantagalo virus, descrito como uma cepa de Vaccinia virus, havendo apenas alteração de um nucleotídeo na posição 616 com mudança de um aminoácido na proteína na posição 206. A análise filogenética mostrou que os isolados se agruparam junto aos Cantagalo virus, outras cepas de Vaccinia virus e Rabbitpox virus

Zymomonas mobilis an emerging microbial cell factory to produce prebiotics

info:eu-repo/semantics/publishedVersio