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Abstract The pandemic and the geopolitical conflict between Russia and Ukraine are events that have caused economic instability in Peru. Reason that was investigated on the analysis of the biological and chemical characteristics of cabbage fed with compost based on sugarcane residues. The objective was to analyze the physical, chemical and biological characteristics of cabbage from the adequate dose of compost based on sugarcane residues and distance between plants. It is based on the methodology applied with an experimental approach, for which the Completely Random Block Design with a 4x 2 factorial arrangement was used, which consisted of 3 blocks and 8 treatments that were the combination: F1 with 0, F2 with 8, T3 with 10 and F4 with 12 t/ha and spacing (D1) with 0.30 m between plants and 0.60 m between rows and (D2) with 0.35 m between plants and 0.60 m between rows. The physical characteristics of cabbage were evaluated and processed by analysis of variance, nutrient concentrations in leaves and stomatal density were analyzed. The results determined that T7 stood out in plant height with 41.88 cm, yield with 26.76 tn/ha and T6 in root length with 20.22 cm. In chemical analysis of leaves T1 stood out in nitrogen, phosphorus, potassium and T4 in calcium, magnesium and sulfur. In T7 stomata density with 977 stomata/mm2. It concludes that at an adequate dose and greater distance that T7 stands out in the concentration of nutrients that are within normal values and high density of stomata; Therefore, these characteristics influenced the optimal biochemical reactions, which obtained good development and yield that differed at 51.39% and 32.17% with respect to the controls T1 and T5.

Resumo A pandemia e o conflito geopolítico entre a Rússia e a Ucrânia são eventos que têm causado instabilidade econômica no Peru. Motivo que foi investigado na análise das características biológicas e químicas do repolho alimentado com composto à base de resíduos da cana-de-açúcar. O objetivo foi analisar as características físicas, químicas e biológicas do repolho a partir da dose adequada de composto à base de resíduos da cana-de-açúcar e distância entre plantas. Baseia-se na metodologia aplicada com uma abordagem experimental, para a qual foi utilizado o Delineamento de Blocos Completamente Aleatório com arranjo fatorial 4 x 2, que consistia em 3 blocos e 8 tratamentos que eram a combinação: F1 com 0, F2 com 8, T3 com 10 e F4 com 12 toneladas/ha e espaçamento (D1) com 0,30 m entre plantas e 0,60 m entre linhas e (D2) com 0,35 m entre plantas e 0,60 m entre linhas. As características físicas do repolho foram avaliadas e processadas por análise de variância, as concentrações de nutrientes nas folhas e a densidade estomática foram analisadas. Os resultados determinaram que T7 se destacou em altura de planta com 41,88 cm, produtividade com 26,76 tn/ha e T6 em comprimento de raiz com 20,22 cm. Na análise química das folhas T1 se destacou em nitrogênio, fósforo, potássio e T4 em cálcio, magnésio e enxofre. Em densidade de estômatos T7 com 977 estômatos/mm2. Conclui que em dose adequada e maior distância que T7 se destaca na concentração de nutrientes que estão dentro dos valores normais e alta densidade de estômatos; Portanto, essas características influenciaram nas reações bioquímicas ótimas, que obtiveram bom desenvolvimento e rendimentos que diferiram em 51,39% e 32,17% em relação aos controles T1 e T5.

https://doi.org/10.1590/1519-6984.275698

Mathematical modeling and forecasting of COVID-19: experience in Santiago de Cuba province
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Ramirez-Torres, E. E.

; Selva Castañeda, A. R.

; Rodríguez-Aldana, Y.

; Sánchez Domínguez, S.

; Valdés García, L. E.

; Palú-Orozco, A.

; Oliveros-Domínguez, E. R.

; Zamora-Matamoros, L.

; Labrada-Claro, R.

; Cobas-Batista, M.

; Sedal-Yanes, D.

; Soler-Nariño, O.

; Valdés-Sosa, P. A.

; Montijano, J. I.

; Bergues Cabrales, L. E.

Revista mexicana de física

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feb 2021, Volume 67 N. 1 Pages 123 - 136

Abstract: En | Text: En | PDF: En

Abstract In the province of Santiago de Cuba, Cuba, the COVID-19 epidemic has a limited progression that shows an early small-number peak of infections. Most published mathematical models fit data with high numbers of confirmed cases. In contrast, small numbers of cases make it difficult to predict the course of the epidemic. We present two known models adapted to capture the noisy dynamics of COVID-19 in the Santiago de Cuba province. Parameters of both models were estimated using the approximate-Bayesian-computation framework with dedicated error laws. One parameter of each model was updated on key dates of travel restrictions. Both models approximately predicted the infection peak and the end of the COVID-19 epidemic in Santiago de Cuba. The first model predicted 57 reported cases and 16 unreported cases. Additionally, it estimated six initially exposed persons. The second model forecasted 51 confirmed cases at the end of the epidemic. In conclusion, an opportune epidemiological investigation, along with the low number of initially exposed individuals, might partly explain the favorable evolution of the COVID-19 epidemic in Santiago de Cuba. With the available data, the simplest model predicted the epidemic evolution with greater precision, and the more complex model helped to explain the epidemic phenomenology.

https://doi.org/10.31349/revmexfis.67.123 10 downloads

Correspondence between formulations of Avrami and Gompertz equations for untreated tumor growth kinetics
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Villar Goris, N. A.

; Selva Castañeda, A. R.

; Ramirez-Torres, E. E.

; Bory Reyes, J.

; Randez, L.

; Bergues Cabrales, L. E.

; Montijano, J. I.

Revista mexicana de física

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oct 2020, Volume 66 N. 5 Pages 632 - 636

Abstract: En | Text: En | PDF: En

Abstract The classical and modified equations of Kolmogorov-Johnson-Mehl-Avrami are compared with the equations of conventional Gompertz and Montijano-Bergues-Bory-Gompertz, in the frame of growth kinetics of tumors. For this, different analytical and numerical criteria are used to demonstrate the similarity between them, in particular the distance of Hausdorff. The results show that these equations are similar from the mathematical point of view, and the parameters of the Gompertz equation are explicitly related to those of the Avrami equation. It is concluded that Modified Kolmogorov-Johnson-Mehl-Avrami and Montijano-Bergues-Bory-Gompertz equations can be used to describe the growth kinetics of unperturbed tumors.

https://doi.org/10.31349/revmexfis.66.632 2 downloads

Analysis of intra-day fluctuations in the mexican financial market index
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Alfonso, L.

; Garcia-Ramirez, D. E.

; Mansilla, R.

; Terrero-Escalante, C. A.

Revista mexicana de física

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oct 2020, Volume 66 N. 5 Pages 700 - 709

Abstract: En | Text: En | PDF: En

Abstract In this paper, a statistical analysis of high-frequency fluctuations of the IPC, the Mexican Stock Market Index, is presented. A sample of tick- to-tick data covering the period from January 1999 to December 2002 was analyzed, as well as several other sets obtained using temporal aggregation. The results indicate that the highest frequency is not useful to understand the Mexican market because almost two-thirds of the information corresponds to inactivity. For the frequency where fluctuations start to be relevant, the IPC data does not follow any α-stable distribution, including the Gaussian, perhaps because of the presence of autocorrelations. For a long-range of lower-frequencies, but still, in the intra-day regime, fluctuations can be described as a truncated Lévy flight, while for frequencies above two-days, a Gaussian distribution yields the best fit. Thought these results are consistent with other previously reported for several markets, there are significant differences in the details of the corresponding descriptions.

https://doi.org/10.31349/revmexfis.66.700 5 downloads

Factores asociados al consumo de tabaco en estudiantes universitarios de lima metropolitana
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Correa-López, Lucy E.

; Morales-Romero, Andrea M.

; Olivera-Ruiz, Jesús E.

; Segura-Márquez, Carmen L.

; Cedillo-Ramirez, Lucy

; Luna-Muñoz, Consuelo

Revista de la Facultad de Medicina Humana

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apr 2020, Volume 20 N. 2 Pages 227 - 232

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

ABSTRACT Introduction: Tobacco use is harmful to health, according to the World Health Organization (WHO) smoking is the cause of death for approximately 8 million people each year. Objective: The purpose of the research was to determine the factors associated with tobacco consumption in university students from Metropolitan Lima. Methods: The sample consisted of 447 students from different universities in Lima, a previously validated survey was applied: Fagerstrom test to measure tobacco consumption. Subsequently, the data was analyzed using distribution, frequency and contingency tables. In addition, regression statistical test was applied to obtain the prevalence ratios (PR) of the study variables in both bivariate and multivariate analyzes, with a 95% confidence interval (95% CI). Results: It was evidenced that there is a significant association between male sex and smoking (p = 0.01), with an RP = 1,67 and 95% CI = . It was also observed that having smoking parents was statistically associated with smoking in university students, with a value of p=0.00, and an RP=2,53 with a 95% CI = . No significant association was found between the variables age and social pressure. Conclusion: The variables sex and smoking parents have a significant association with tobacco consumption, emphasizing that both our family and academic environment deserve to be safe, healthy and free of tobacco smoke.

RESUMEN Introducción : El consumo de tabaco es perjudicial para la salud, según la Organización Mundial de la Salud (OMS) el tabaquismo es la causa de muerte de aproximadamente 8 millones de personas cada año. Objetivo : El propósito de la investigación fue determinar los factores asociados al consumo de tabaco en estudiantes universitarios de Lima Metropolitana. Métodos : La muestra estuvo conformada por 447 estudiantes de diferentes universidades de Lima, se aplicó una encuesta previamente validada: Test de Fagerstrom para medir el consumo de tabaco. Posteriormente los datos fueron analizados utilizando tablas de distribución, frecuencias y contingencia. Además, se aplicó la prueba estadística regresión para obtener las razones de prevalencias (RP) de las variables de estudio tanto en el análisis bivariado como en el multivariado, con un intervalo de confianza al 95% (IC al 95%). Resultados : Se evidenció que existe asociación significativa entre el sexo masculino y el hábito de fumar (p=0,01), con un RP = 1,67 e IC al 95% = (1,03 - 2,23). También se pudo observar que tener padres fumadores estuvo estadísticamente asociado al hábito tabáquico en los universitarios, con un valor de p=0,00, y un RP = 2,53 con IC al 95% = (1,62 - 3,52). No se encontró asociación significativa entre las variables edad y presión social. Conclusión : Las variables sexo y padres fumadores tienen asociación significativa con el consumo de tabaco enfatizando que tanto nuestro entorno familiar como académico merece ser seguro, saludable y libre del humo de tabaco.

https://doi.org/10.25176/rfmh.v20i2.2872

Procedimientos a nivel de ganglio impar
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Restrepo-Garces, C. E.

; Gomez Bermudez, C. M.

; Jaramillo Escobar, S.

; Jazmin Ramirez, L.

; Vargas, J. F.

Revista de la Sociedad Española del Dolor

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jun 2013, Volume 20 N. 3 Pages 150 - 154

Abstract: Es | Text: Es | PDF: Es

4624 downloads Cited 1 time in SciELO

Caracterização elétrica de blocos varistores à base de SnO2
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Brito, R. L.

; Pessôa, P. A. P.

; Vasconcelos, J. S.

; Santos, L. P. S. dos

; Rangel, J. H. G.

; Longo, E.

; Sousa, V. C. de

; Ramirez, M. A.

; Oliveira, M. M.

Cerâmica

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sep 2012, Volume 58 N. 347 Pages 349 - 356

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Neste trabalho foi realizado um estudo das propriedades elétricas de blocos varistores à base de SnO2. Foram avaliadas a não linearidade destas cerâmicas por meio da caracterização tensão-corrente, bem como a altura, largura e os portadores de cargas por espectroscopia de impedância, além das energias de ativação. Os valores de α foram relativamente baixos sendo o maior valor de 6,3 para o sistema 98,65%SnO2.1,00%Co2O3.0,05%Nb2O5.0,05%Cr2O3.0,25%Pr2O3 (SCNCrPr). O sistema 98,65%SnO2.1,00%Co2O3.0,05%Nb2O5. 0,05%Cr2O3.0,25%La2O3 (SCNCrLa) apesar de apresentar um tamanho médio de grão pequeno 1,66 μm, possuiu um valor muito baixo de Er, o que pode está associado a não formação de barreiras efetivas na região de contorno de grão, gerando uma corrente de fuga elevada da ordem de 230 μA.

This paper reports on a study of the electrical properties of SnO2-based varistor blocks. The nonlinearity of these ceramics was evaluated based on their voltage-current characteristics, while the height, width and charge carriers were evaluated by impedance spectroscopy and activation energies. The α values were relatively low, with the SCNCrPr system showing the highest value: 6.3. Although the average grain size of the SCNCrLa system was small, i.e., 1.66 μm, its Er value was very low, which may be attributed to the non-formation of effective barriers in the grain boundary region, thus generating a high leakage current in the order of 230 μA.

2775 downloads

In vivo fluctuation of Tax, Foxp3, CTLA-4, and GITR mRNA expression in CD4+CD25+ T cells of patients with human T-lymphotropic virus type 1-associated myelopathy
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Ramirez, E.

; Cartier, L.

; Rodriguez, L.

; Alberti, C.

; Valenzuela, M.A.

Brazilian Journal of Medical and Biological Research

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nov 2010, Volume 43 N. 11 Pages 1109 - 1115

Abstract: En | Text: En | PDF: En

HTLV-1 Tax expression exerts an inhibitory effect on the Foxp3 transcription factor in CD4+CD25+ T-regulatory cells (Treg). For a better understanding of the role of Tax mRNA in the gene expression of cellular markers we measured Tax, Foxp3, CTLA-4, GITR, TGF-β, and IL-10 mRNA in Treg cells of 50 patients with human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP; 27 women and 23 men; mean age: 56.7 years). The control group consisted of 23 non-infected subjects (12 women and 11 men) with a mean age of 51.3 years. Real-time PCR was used to measure mRNA of Tax proteins and several cellular markers of Treg function. Determinations revealed a high level of Tax mRNA in HAM/TSP (124.35 copies/100 CD4+CD25+ T cells). Foxp3, GITR, and CTLA-4 mRNA levels were lower in HAM/TSP patients (mean ± SD, 22.07 ± 0.78, 9.63 ± 0.36, and 4.54 ± 0.39, respectively) than in non-infected controls (47.15 ± 12.94, 22.14 ± 1.91, and 21.07 ± 2.31). Both groups had similar levels of TGF-β and IL-10. An inverse relationship was found between Tax levels and Foxp3, CTLA-4, and GITR levels. Conversely, there was a direct correlation between levels of Foxp3, GITR, and CTLA-4. Disease severity and evolution time did not correlate with Tax or Foxp3 levels. The present results suggest that Tax and Foxp3 mRNA vary with the same degree of disease severity in HAM/TSP patients. Tax fluctuations may affect CTLA-4 and GITR expression via the Foxp3 pathway, causing virus-induced dysfunction of CD4+CD25+ T cells in HAM/TSP patients.

1988 downloads

Producción de proteína y biomasa probiótica de Lactobacillus casei liofilizadas a partir de suero de leche de cabra
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Aguirre-Ezkauriatza, E. J.

; Ramirez-Medrano, A.

; Aguilar-Yáñez, J. M.

; Alvarez, M. M.

Revista mexicana de ingeniería química

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apr 2009, Volume 8 N. 1 Pages 67 - 76

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

In this communication, we document the technical feasibility of elaboration of two added value products from goat whey: (a) freeze-dried protein and (b) freeze-dried probiotic biomass of Lactobacillus casei. Results from goat milk whey ultrafiltration experiments are presented, from which high protein/lactose ratio protein is recovered. In its lyophilized form, this protein presents superior solubility characteristics with respect to analogous commercial products. The ultrafiltration permeate was utilized as growth culture medium for the probiotic microorganism L. casei. Results from batch and fed-batch fermentation experiments are reported. The growth kinetics of L. casei in de-proteinized goat milk whey is analyzed. From batch experiments, a kinetic characterization is conducted. A strong inhibition of biomass growth by lactic acid production is observed. Fed-batch strategies resulted in higher average productivities, lower residual substrate concentrations, and higher product viable counts than batch strategies.

En este trabajo se documenta la factibilidad técnica de obtención de dos productos de valor agregado a partir de suero de leche de cabra: (a) proteína liofilizada y (b) biomasa probiótica liofilizada de Lactobacillus casei. Se presentan resultados de experimentos de ultrafiltración de suero de leche de cabra (SLC), del cual se retiene proteína con una alta relación proteína/lactosa. En su forma liofilizada, esta proteína presentó características de solubilidad superiores a productos comerciales similares. El permeado resultante del ultrafiltrado de SLC fue utilizado como medio de cultivo para el crecimiento del microorganismo probiótico L. casei. Se reportan resultados de experimentos de fermentación de suero de leche por lote y lote alimentado para la producción de biomasa. La cinética de crecimiento de L. casei en SLC desproteinizado no suplementado es analizada a partir de datos de experimentos por lotes. Se observa un marcado efecto inhibitorio del crecimiento bacteriano asociado a la producción de ácido láctico. Las estrategias por lote alimentado aquí reportadas resultan en productividades superiores, concentraciones de sustrato residual menores y viabilidades más altas del producto respecto a procesos por lote.

19934 downloads

10.

13ra OLIMPIADA BOLIVIANA DE FISICA, 3ra OLIMPIADA BOLIVIANA DE ASTRONOMIA Y ASTROFISICA
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Bustos, R.

; Justiniano, I.

; Jaillita, J. C.

; Argandoña, A.

; Ramirez, M.

; Zubieta, V.

; Sanjinés, D.

; Brañez, A.

; Espinoza, W.

; Apaza, R.

; Vargas, Ch.

; Mayta, R.

; Cordero, M.

; Tavera, W.

; Andrade, M.

; Guzmán, R.

; Vallejos, V.

; Guaygua, T.

; Castelo, J. J.

; Jemio, C.

; Payllo, P.

; Mamani, R.

; Coca, N.

; Gutiérrez, V. H.

; Martínez, L.

; Chavarria, V.

; Copa, O.

; Condori, V. H.

; Condori, H.

; Salvatierra, R.

; Centeno, E.

; Miranda, J.

; Ibieta, J. P.

; Mendoza, N.

; Coronel, A.

Revista Boliviana de Física

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2009, Volume 15 N. 15 Pages 73 - 90

Abstract: Es | Text: Es | PDF: Es

La 13ra Olimpiada Boliviana de Física (13ra OBF) y 3ra Olimpiada Boliviana de Astronomía y Astrofísica (3ra OBAA) se llevaron a cabo simultáneamente y con éxito del 28 de Noviembre al 1 de Diciembre de 2008 en la ciudad de Cobija, Pando, en los ambientes de de la Facultad de Ingeniería de la Universidad Amazónica de Pando (UAP).

1902 downloads

11.

Sepsis urológica secundaria a cistitis enfisematosa
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Molina Suárez, J.L.

; Abengozar García-Moreno, A.

; Ramirez Zambrana, A.

; Laguna Álvarez, E.

; Fernández Alarcón, L.

; Arroyo Masa, M.I.

Actas Urológicas Españolas

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sep 2008, Volume 32 N. 8 Pages 858 - 860

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

Emphysematous cystitis is a rare infectious disease which diagnosis requires a high grade of suspicion in patients with compatible clinical symptoms, risk factors that make them susceptible, and a radiographic examination that confirm the suspicion. Patients usually have a favorable evolution with an early diagnosis and an appropriate management. We present a 75 years old diabetic patient with emphysematous cystitis that develops into an urosepsis treated in a conservative management.

La cistitis enfisematosa es una patología infecciosa rara cuyo diagnóstico requiere un alto grado de sospecha ante una clínica compatible en pacientes con factores de riesgo que le hagan susceptible, y unos datos radiográficos que confirmen dicha sospecha. Habitualmente evolucionan bien con un diagnóstico precoz y un manejo adecuado. Presentamos un caso de cistitis enfisematosa en un paciente de 75 años, diabético, que evoluciona a un estado séptico tratado de forma conservadora.

801 downloads

12.

Characterization and experimental infection of Flexibacter maritimus (Wakabayashi et al. 1986) in hatcheries of post-larvae of Litopenaeus vannamei Boone, 1931
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Mouriño, JLP.

; Vinatea, L.

; Buglione-Neto, C.

; Ramirez, CT.

; Vieira, FN.

; Pedrotti, F.

; Martins, ML.

; Derner, RB.

; Aguilar, MA.

; Beltrame, E.

Brazilian Journal of Biology

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feb 2008, Volume 68 N. 1 Pages 173 - 177

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Neste trabalho, relata-se um estudo preliminar para caracterizar bactérias filamentosas associadas a elevadas mortalidades de larvas e pós-larvas cultivadas no Estado de Santa Catarina, Brasil. Um extrato de larvas infectadas foi diluído em diferentes concentrações, cultivado em Agar Marine (DifcoTM, Marine Agar 2216) e incubado a 30° C por 48 horas. A caracterização bioquímica inclui reações de amido, gelatina e tirosesine, crescimento em Agar TCBS,crescimento a 0 e 37‰ de salinidade, produção de pigmentos em Agar Tirosine, produção de H2S, redução de nitrato, reação vermelho congo, oxidase e catalase. A bactéria isolada apresentou características de Flexibacter maritimus, um bacilo Gram negativo de 0,4-0,5 µm de largura e 15 µm de comprimento. Os experimentos foram realizados sobre a patogenicidade de F. Maritimus, em pós-larvas de L. vannamei. Foram avaliados a sobrevivência e os sintomas das pós-larvas 24 horas após a inoculação com F. Maritimus, além do seu crescimento em Agar Marine. Foram encontradas mortalidades de 92,5% e sintomas próprios da enfermidade, tais como lesões melanizadas em várias partes do corpo, descoloração das brânquias e diminuição da motilidade e da alimentação. Com base nos resultados da infecção experimental, pode se concluir que a bactéria isolada do gênero Flexibacter é patogênica para pós-larvas de L. vannamei.

A preliminary study to characterize filamentous bacteria, whose presence is related to high mortality of Litopenaeus vannamei larvae cultured in Santa Catarina State, Brazil, is reported. The extract of infected larvae was diluted in different concentrations, cultured in marine agar (DifcoTM, Marine Agar 2216) and incubated at 30 °C for 48 hours. The biochemical characterization included hydrolytic reactions of starch, gelatin and tyrosine, growth in TCBS agar, growth in 0 and 37‰ salinity, pigment production in tyrosine agar, production of H2S, nitrate reduction, congo red reaction, oxidase and catalase. The isolated bacteria belong to the species Flexibacter maritimus, Gram-negative bacilli of 0.4-0.5 µm width and 15 µm length. Experiments were carried out on pathogenicity of F. maritimus in post-larvae of L. vannamei. Survival and symptoms in L. vannamei post-larvae 24 hours after inoculation with F. maritimus and its growth in marine agar were evaluated. Mortality was detected around 92,5% as well as symptoms like melanized lesions in several parts of body, discolouration of gills, bad formation of appendages and of the last abdominal segment, low motility and feeding reduction. The experimental infection results suggested that isolated bacteria of the genus Flexibacter are pathogenic to the shrimp Litopenaeus vannamei post-larvae.

3542 downloads

13.

DIPLOMADOEN FÍSICA PARA PROFESORES DE COLEGIO DFIS
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Bustos, R.

; Sanjinés, D.

; Ramirez, M.

; Subieta, V.

; Blacutt, L.

; Burgoa, A.

; Velarde, A

; Ormachea, L.

; Ricaldi, E.

; Poma, I.

Revista Boliviana de Física

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2008, Volume 14 N. 14 Pages 150 - 155

Abstract: Es | Text: Es | PDF: Es

2016 downloads

14.

Wavelet-network based on L1-norm minimisation for learning chaotic time series
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Alarcon-Aquino, V.

; Garcia-Treviño, E. S.

; Rosas-Romero, R.

; Ramirez-Cruz, J. F.

; Guerrero-Ojeda, L. G.

; Rodriguez-Asomoza, J.

Journal of applied research and technology

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- SciELO Analytics

2005, Volume 3 N. 3 Pages 211 - 219

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

This paper presents a wavelet-neural network based on the L1-norm minimisation for learning chaotic time series. The proposed approach, which is based on multi-resolution analysis, uses wavelets as activation functions in the hidden layer of the wavelet-network. We propose using the L1-norm, as opposed to the L2-norm, due to the well-known fact that the L1-norm is superior to the L2-norm criterion when the signal has heavy tailed distributions or outliers. A comparison of the proposed approach with previous reported schemes using a time series benchmark is presented. Simulation results show that the proposed wavelet-network based on the L1-norm performs better than the standard back-propagation network and the wavelet-network based on the traditional L2-norm when applied to synthetic data.

En este artículo se presenta una red neuronal-wavelet basada en la minimización de la norma L1 para aprendizaje de series de tiempo caóticas. El método propuesto, el cuál se basa en un análisis multi-resolución, utiliza wavelets como funciones de activación en la capa oculta de la red neuronal-wavelet. Se propone utilizar la norma L1, en lugar de la tradicional norma L2, debido a que la norma L1 es superior a la norma L2 cuando la señal tiene distribuciones sesgadas o de colas pesadas. Se presenta una comparación del método propuesto con esquemas reportados previamente utilizando series de tiempo caóticas conocidas. Los resultados de simulación revelan que la red neuronal-wavelet basada en la norma L1 tiene una mejor eficiencia que la red neuronal con propagación hacia atrás y la red neuronal-wavelet basada en la tradicional norma L2 cuando se aplica a datos sintéticos.

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Simulation interface for technical training in detection of flaws
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Pérez, J. L.

; Cabiedes, F.

; Gamboa, F.

; Viniegra, A.

; Bernal, E.

; Ramirez, J.

; Guerrero, A.

; Guzmán, J. L.

Journal of applied research and technology

Journal Metrics
- Sobre o periódico
- SciELO Analytics

2004, Volume 2 N. 1 Pages 21 - 25

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

In this paper we present a computer program with educational purposes, based on the substitution of student's beliefs by formal knowledge via personal experience. This is done through the application of formal knowledge acquired in class, to contextualized tasks in the student's environment that also allows him/her to obtain and consolidate basic information that is not embedded in his/her mind. The program is designed to present a game like exercise that allows the student to face conditions similar to those of real life.

En este trabajo se presenta un programa de computadora con fines educativos, basado en la sustitución de las creencias del estudiante por conocimiento formal via experiencia personal. Esto, mediante la aplicación del conocimiento formal adquirido en clase a tareas contextualizadas en el medio ambiente del estudiante, lo cual le permite obtener y consolidar información básica no arraigada en su mente. El programa está diseñado para presentar un ejercicio parcialmente lúdico, que le permite enfrentarse a condiciones similares a las de la vida real.

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