165 research outputs found
Distance Functions and Normalization Under Stream Scenarios
Data normalization is an essential task when modeling a classification
system. When dealing with data streams, data normalization becomes especially
challenging since we may not know in advance the properties of the features,
such as their minimum/maximum values, and these properties may change over
time. We compare the accuracies generated by eight well-known distance
functions in data streams without normalization, normalized considering the
statistics of the first batch of data received, and considering the previous
batch received. We argue that experimental protocols for streams that consider
the full stream as normalized are unrealistic and can lead to biased and poor
results. Our results indicate that using the original data stream without
applying normalization, and the Canberra distance, can be a good combination
when no information about the data stream is known beforehand.Comment: Paper accepted to the 2023 International Joint Conference on Neural
Network
Expressão e análise antigênica da proteína RTP36 recombinante da amostra São Paulo de Ehrlichia canis para testes sorológicos
Ehrlichia canis is the main etiological agent of canine monocytic ehrlichiosis (CME), a globally canine infectious disease. In Brazil, CME is considered to be endemic, and its prevalence can reach 65% in some states. The diagnosis of ehrlichiosis is important for treatment and epidemiological purposes. The E. canis TRP36 (Tandem Repeat Protein) protein elicits the earliest acute-phase antibody response observed during the course of the disease. This study aimed to generate the recombinant TRP36 protein from E. canis São Paulo strain and to evaluate its potential as a tool for the serologic diagnosis of CME. The E. canis São Paulo isolate was cultivated in DH82 lineage cells, and its genomic DNA was obtained. The bacterial DNA fragment encoding the entire ORF of TRP36 was cloned into the pBAD/Thio-TOPO vector and transformed into Escherichia coli DH10B competent cells with the trp36-bearing plasmid for protein expression. To evaluate the protein antigenicity, 16 canine serum samples were previously tested (by PCR and the commercial SNAP4Dx serological test). The results were in accordance with the SNAP4Dx test. Experiments using this recombinant protein as an antigen, targeting the development of a serologic test based on ELISA methodology, are the next step to produce a reliable, affordable and useful diagnostic tool for CME in Brazil.Ehrlichia canis é o principal agente etiológico da erliquiose monocítica canina (EMC), uma doença infecciosa canina globalmente dispersa. No Brasil, a EMC é considerada endêmica, e a infecção pode atingir 65% em cães em alguns estados. O diagnóstico de erliquiose é importante para fins de tratamento e epidemiológicos. A proteína TRP36 de E. canis leva a uma resposta humoral com produção de anticorpos em fase aguda, encontrada durante o curso da doença. O objetivo deste estudo foi obter a proteína TRP36 recombinante da amostra São Paulo de E. canis e avaliar seu potencial como ferramenta para o diagnóstico sorológico da CME. O isolado de E. canis São Paulo foi cultivado em células da linhagem DH82 e o DNA genômico foi obtido. O fragmento de DNA bacteriano que codifica toda a ORF de TRP36 foi clonado no vetor pBAD / Thio-TOPO e transformado em células competentes Escherichia coli DH10B, com o plasmídeo portador de trp36 para expressão de proteínas. Para avaliar a antigenicidade da proteína, 16 amostras de soro canino foram previamente analisadas (por PCR e teste sorológico comercial SNAP4Dx). Os resultados estavam de acordo com o teste SNAP4Dx. Os experimentos que utilizam essa proteína recombinante como antígeno, visando ao desenvolvimento de um teste sorológico baseado no ELISA, são o próximo passo para produzir um teste de diagnóstico confiável, acessível e útil para o diagnóstico da EMC no Brasil
Progresso genético com a seleção recorrente recíproca para híbridos interpopulacionais de milho
Economic viability of the use of crude glycerin supplements in diets for grazing crossbred calves
Bryophyte flora in upland forests at different successional stages and in the various strata of host trees in northeastern Pará, Brazil
Comparative evaluation of the pH of calcium hydroxide powder in contact with carbon dioxide (CO2)
Antioxidant activities of sulfated polysaccharides from brown and red seaweeds
The in vitro antioxidant activities of the following six sulfated polysaccharides were investigated: iota, kappa and lambda carrageenans, which are widely used in the food industry, fucoidan (homofucan) from the edible seaweed Fucus vesiculosus and fucans (heterofucans) F0.5 and F1.1 from the seaweed Padina gymnospora. With respect to the inhibition of superoxide radical formation, fucoidan had an IC50 (the half maximal inhibitory concentration) of 0.058 mg·mL−1, while the IC50 for the kappa, iota and lambda carrageenans were 0.112, 0.332 and 0.046 mg·mL−1, respectively. All of the samples had an inhibitory effect on the formation of hydroxyl radicals. The results of peroxidation tests showed that fucoidan had an IC50 of 1.250 mg·mL−1 and that the kappa, iota and lambda carrageenans had an IC50 of 2.753 and 2.338 and 0.323 mg·mL−1, respectively. Fucan fractions showed low antioxidant activity relative to fucoidan. These results clearly indicate the beneficial effect of algal polysaccharides as antioxidants
ESTUDO QUANTITATIVO DA VARIAÇÃO ESTRUTURAL MORFOLÓGICA NA MADEIRA DE Calophyllum brasiliense
Desafíos políticos de los países de inmigración
13 págs.-- Publicado en "Confluencia XXI. Revista de Pensamiento Político" (México), nº 3 (Oct-Dic 2008) bajo el título monográfico "Migrantes: ¿Por qué se van? ¿Por qué se quedan?".Las migraciones, una práctica tan antigua como la propia condición humana, se han
convertido en un factor estructural de primer orden, en uno de los macrofenómenos
más definitorios de nuestra época y en un complejo reto para las sociedades
contemporáneas. En prácticamente todos los países del mundo, todo lo que concierne a este complejo fenómeno ocupa un lugar
destacado en la agenda política. La gestión, el control y la integración de los movimientos internacionales de personas se presentan como un policy field de creciente y prioritaria relevancia. No se trata, sin embargo, de una cuestión de mera moda: el
número de países implicados de manera significativa en las migraciones internacionales ha aumentado considerablemente, hasta el punto de que resulta realmente difícil encontrar algún
Estado que no sea bien un país de inmigración, bien un país de emigración
o bien ambas cosas a la vez, cuando no al menos un país de tránsito. No ha de extrañar
entonces que la mayoría de los gobiernos haya tomado conciencia de la necesidad
de ofrecer una respuesta en términos legales e institucionales a un fenómeno
de carácter permanente que puede llegar a alterar la estructura demográfica, social,
cultural, económica y laboral de un país. Dada la complejidad de la cuestión, y por cuestiones de economía argumentativa, aquí se abordará de manera fundamental desde la perspectiva de los países receptores, que, por lo demás, es también la adoptada en forma habitual por los países europeos que registran mayor inmigración. Sin embargo,
el fenómeno migratorio es fundamentalmente transnacional y tiene fehacientes
repercusiones en los países de emigración.Peer reviewe
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