Inferência sobre as principais medidas estatísticas de avaliação e comparação de modelos: Rotina R.

Com grande satisfação, apresentamos o documento intitulado Inferência sobre as Principais Medidas Estatísticas de Avaliação e Comparação de Modelos: Rotina R, que trata de organizar em um único local os principais métodos utilizados de avaliação de modelos por comparações estatísticas entre variáveis observadas e simuladas. Nos documentos que geralmente tratam deste assunto, somente três medidas estatísticas de avaliação de erros (dispersão e variação) são exploradas. A razão disso, em geral, não é mencionada e podem ser diversas, como por exemplo, a falta de conhecimento técnico para averiguar a adequação de outros métodos disponíveis ou, até mesmo, a falta de ferramentas estatísticas que disponibilizem os outros métodos de avaliação existentes na literatura de maneira simples, prática e objetiva, independentemente de serem complementares ou substitutivos dos que normalmente são utilizados. No dia a dia, presenciam-se grandes desafios na agricultura, como as revoluções na biotecnologia e a renovação tecnológica que invade o campo convergindo para o que chamamos de agricultura digital. A Embrapa Cerrados é uma unidade de pesquisa cuja atuação tem sido focada no desenvolvimento de soluções, entre elas, as voltadas para o campo da bioinformática para a agricultura, acompanhando as tendências de novas ferramentas que têm sido desenvolvidas, como por exemplo, a aplicação de uma poderosa ferramenta livre chamada R, implementando projetos e ações de forma a incorporar inovações ao contexto agropecuário, devolvendo todo o investimento que tem sido feito na pesquisa

Shelf life of minimally processed cassava roots submitted to different conservation methods.

The useful life of minimally processed cassava roots submitted to different conservation methods was evalu­ated. Cassava roots in natura were physically characterized, minimally processed and stored after submission to treatments in different packaging types. During storage period, the product was submitted to physicochemi­cal, sensorial and microbiological analyzes. Storage time and treatment influenced on minimally processed cassava roots quality. When only the sensorial analysis is considered, the useful life of minimally processed cassava roots was of 28 days for all treatments, except for the roots submitted to the CONTROL and CA treat­ments, which had a 24-day shelf life. However, at 14 days of storage, CONTROL, VAC, CA, and H2O treat­ments showed high psychotrophic count. Mold and yeast counts were also high for CONTROL and VAC treat­ments at 14 days of storage. At 28 days of storage, psychrotrophs, molds and yeasts count was high for all treatments. In general, the most recommended treatments, due to having a longer shelf life, were CA and H2O reaching a maximum period of 14 days of storage. Considering the cooking time and the other physicochemical analyzes, the 2.5% H2O+CA treatment is not recommended for the commercialization of minimally processed cassava roots

Experimental Adhesion Prevention Studies: A Comparative Study in a Rabbit Model

Background: Adhesions formation after abdominal surgery is a problem that causes many complications in the patient’s future life. In this study we compare the possible individual effects of Ringer ́s lactate, Adept® and Mesofol® and the combined effects of Adept® and Mesofol® in the prevention of post surgical adhesions formation in a standardised rabbit model.Materials and Methods: 90 rabbits were divided into 9 groups. The same experimental method was used in all rabbits to produce adhesions, consisting of cecal and sigmoid abrasion and excision of parietal peritoneum. The rabbits were operated after 2 weeks to assess the adhesions occurring. The results were analysed using the chi-square test and the Fisher exact test when needed.Results: Comparison of adhesion stages demonstrated a significant difference between the control group and the Adept® groups (p<0.05) in both branches. The adhesion grade of the combined treatment groups (G5 and G9) was not statistically significant (p>0.05). In the Mesofol® group and the combined group, four and two rabbits, respectively, developed granulomas. Conclusions: Adept® used individually reduced the adhesion grade. The Adept® and Mesofol® combination was less effective in reducing adhesion formation in comparison to the Adept® group by itself. On the other hand, in our experimental study, the usage of Mesofol®, alone or in combination, caused foreign body granulomas in 6 animals. Although the literature is very sufficient in comparison several materials for decreasing adhesion formation, we believe that our study provides more valuable evidence in this area. Due to the appearance of six cases of foreign body granulomas, detailed studies focused on this matter are needed in the future. Keywords: Post-operative adhesions; comparative study; prevention; rabbit model. Introdução: A formação de aderências após a cirurgia abdominal é um problema que causa muitas complicações na vida futura do doente. Neste estudo, comparamos os possíveis efeitos individuais do Ringer lactato, Adept® e do Mesofol®, e os efeitos combinados do Adept® e do Mesofol® na prevenção da formação de aderências pós-cirúrgicas num modelo padronizado de coelhos.Materiais e Métodos: 90 coelhos foram divididos em nove grupos. O mesmo método experimental foi utilizado em todos os coelhos para favorecer a produção de aderências, realizando abrasão do cego e da sigmoideia e excisão do peritoneu parietal. Os coelhos foram operados após duas semanas para avaliar a ocorrência de aderências. Os resultados foram analisados por meio do teste do qui-quadrado e do teste exacto de Fisher, quando necessário.Resultados: A comparação em estadios de aderência demonstrou uma diferença significativa entre o grupo controlo e os grupos Adept® (p <0,05) em ambos os ramos. O grau de aderências dos grupos de tratamento combinado (G5 e G9) não foi estatisticamente significativo (p <0,05). No grupo do Mesofol® e no grupo combinado, quatro e dois coelhos, respectivamente, desenvolveram granulomas. Conclusões: Adept® utilizado individualmente reduziu o grau de aderências. O Adept® combinado com o Mesofol® foi menos eficaz na redução da formação de aderências em comparação com o grupo do Adept®, por si só. Por outro lado, o uso de Mesofol® isoladamente ou em conjunto podem aumentar o risco de granulomas. Estudos mais detalhados são necessários, e futuros estudos sobre a eficácia de um material para diminuir a formação de aderências deve incluir uma comparação de controle de diversos materiais num mesmo modelo.Palavras-Chave: aderências pós-operatórias; estudo comparativo; prevenção; modelo animal em coelhos

Assessment of the potential of tin sulphide thin films prepared by sulphurization of metallic precursors as cell absorbers

In this work, SnxSy thin films have been grown on soda-lime glass substrates by sulphurization of metallic precursors in a nitrogen plus sulphur vapour atmosphere. Different sulphurization temperatures were tested, ranging from 300 °C to 520 °C. The resulting phases were structurally investigated by X-Ray Diffraction and Raman spectroscopy. Composition was studied using Energy Dispersive Spectroscopy being then correlated with the sulphurization temperature. Optical measurements were performed to obtain transmittance and reflectance spectra, from which the energy band gaps, were estimated. The values obtained were 1.17 eV for the indirect transition and for the direct transition the values varied from 1.26 eV to 1.57 eV. Electrical characterization using Hot Point Probe showed that all samples were p-type semiconductors. Solar cells were built using the structure: SLG/Mo/SnxSy/CdS/ZnO:Ga and the best result for solar cell efficiency was 0.17%

Mo bilayer for thin film photovoltaics revisited

Thin film solar cells based on Cu(In,Ga)Se2 as an absorber layer use Mo as the back contact. This metal is widely used in research and in industry but despite this, there are only a few published studies on the properties of Mo. Properties such as low resistivity and good adhesion to soda lime glass are hard to obtain at the same time. These properties are dependent on the deposition conditions and are associated with the overall stress state of the film. In this report, a study of the deposition of a Mo bilayer is carried out by analysing first single and then bilayers. The best properties of the bilayer were achieved when the bottom layer was deposited at 10 × 10−3 mbar with a thickness of 500 nm and the top layer deposited at 1 × 10−3 mbar with a thickness of 300 nm. The films deposited under these conditions showed good adhesion and a sheet resistivity lower than 0.8

Effect of anode flow field design in direct methanol fuel cells: preliminary studies

The direct methanol fuel cells are promising candidates for portable power sources due to their high energy density, however studies continue in order to give solutions for a number of drawbacks that affect cell performance and efficiency. Achieving good fuel cell performance requires that the flowing streams of fuel and oxidizer are evenly distributed over the entire surface of the catalyst layer and also an efficient removal of reaction products. This is achieved through the optimal design of the flow field, which primarily depend upon channel pattern as well as channel (and rib) shape and size. In this work the effect of anode flow field design on the performance of an own built DMFC is studied. Preliminary results are herein presented

Agronomic and biochemical evaluation of cassava clones with roots that have pink pulp.

RESUMO: Os programas de melhoramento genético de mandioca de mesa estão focados no desenvolvimento de variedades biofortificadas que aliem aos caracteres agronômicos a presença de carotenoides nas raízes de reserva. Neste trabalho, objetivou-se avaliar características agronômicas e bioquímicas em clones de mandioca de mesa com polpa rosada. Os nove genótipos foram avaliados por duas safras em delineamento experimental de blocos casualizados com três repetições. Dentre os clones avaliados se destacaram: i) para altura da primeira ramificação (390/08, 345/08 e a testemunha IAC 576-70); ii) para altura da planta (390/08, 345/08 e 378/08); iii) para peso da parte aérea sem a cepa (390/08, 406/08, 378/08 e 341/08); iv) para porcentagem de amido nas raízes (378/08, 413/08, 390/08 e a testemunha IAC 576-70); v) para produtividade de raízes (IAC 576-70 e 341/08, 390/08, 406/08 e 387/08). Na safra 2011/2012, todos os clones cozinharam em até 30 minutos, indicando que todos apresentam boas qualidades culinárias. Com relação ao teor de carotenoides totais nas raízes, os clones que se destacaram foram 406/08 e 341/08. Todos os clones avaliados apresentaram teores de HCN nas raízes de reserva de mandioca, inferiores a 100 mg kg-1. Os clones 341/08 e 406/08 apresentam potencial agronômico e bioquímico para cultivo direto pelos produtores na região do Cerrado do Brasil Central e/ou para a utilização como genitores em programas de melhoramento genético de mandioca de mesa. ABSTRACT: Sweet cassava breeding programs are focused on the development of bio fortified cultivars that combine significant amounts of carotenoids in their reserve roots with desirable agronomic. The objective of this research was to evaluate agronomic and biochemical traits in sweet cassava clones with roots that have pink pulp. The nine genotypes were evaluated in two seasons in a randomized block design with three replications. Among the evaluated clones, the following stood out: i) for the height of the first branch (390/08, 345/08 and the control IAC 576-70); ii) for plant height (390/08, 345/08 e 378/08); iii) for shoot weight without original steam cutting (390/08, 406/08, 378/08 e 341/08); iv) for the percentage of starch in roots (378/08, 413/08, 390/08 and the control IAC 576-70); and v) for the root yield (the control IAC 576-70 and 341/08, 390/08, 406/08 e 387/08). In the 2011/2012 season, all clones cooked within 30 minutes, indicating that they all have good culinary qualities. Regarding the total carotenoid content in the roots, the clones that stood out were 406/08 and 341/08. All clones evaluated had HCN content below 100 mg kg-1. Clones 341/08 and 406/08 have agronomic and biochemical potential for direct cultivation by producers in the Cerrado region of Central Brazil and / or for use as stock in sweet cassava breeding programs.Título em português: Avaliação agronômica e bioquímica de clones de mandioca com polpa rosada