A field study was conducted to evaluate productive parameters in layers vaccinated with the Mycoplasma gallisepticum (MG) ts11 vaccine. A total of 9,065 free mycoplasma Hy Line Brown pullets were raised on a previously detected MG positive farm. The birds were divided in two groups and placed in two separated sections in the same farm. One group was vaccinated at four weeks of age and the other remained non vaccinated. Serum plate agglutination (SPA), haemagglutination inhibition (HI) and enzyme linked immunsorbent assay (ELISA) were used to measure the serum antibody response after vaccination and field challenges. Polymerase chain reaction assay (PCR) and cultures were used to determine field challenges by mycoplasma and salmonella. Vaccinated birds laid 188 egg/hen (11.55 kg) whereas non-vaccinated ones laid 184 egg/hen (11.34 kg) over a 41-week period. Feed conversion was 2.57 and 2....

Se evaluaron los parámetros productivos de un lote de gallinas de postura comercial vacunado con la cepa ts11 de Mycoplasma gallisepticum (MG). Se criaron 9,065 pollitas de postura comercial de la línea Hy Line Brown libres de micoplasma en una granja previamente identificada como positiva a MG. La mitad de las aves se vacunó con la cepa ts11 de MG a las cuatro semanas de edad y la otra mitad permaneció sin vacuna. Se midió la producción de huevos y se realizaron las pruebas de aglutinación en placa, inhibición de la hemoaglutinación y ELISA para evaluar el comportamiento serológico de los lotes como respuesta a la vacuna o a los desafíos de campo. Así mismo, se utilizó PCR y cultivos microbiológicos para determinar desafíos de campo por micoplasmas y salmonella. Sobre un periodo productivo de 41 semanas, las aves vacunadas produjeron 188 huevos/ave (11.55 kg) y tuvieron u...

Streamflow forecasting at short horizons is vital for the management of water resources. However, the streamflow behaviour is non-linear and not stationary. To address this challenge, artificial intelligence techniques have been used to increase accuracy. Additionally, signal decomposition techniques such as empirical mode decomposition, ensemble empirical mode decomposition, and variational mode decomposition, have been applied in different fields as a pre-processing stage prior to modelling to improve forecasting. This study evaluates the effect of the aforementioned decomposition techniques used with a recurrent neural network called long short-Term memory to increase the precision of the daily prediction of the Chira river streamflow in northern Peru, characterized by a special dynamic due to a strong seasonal behavior and the influence of the El Niño-Southern Oscillation (ENSO). ©...

It introduces a dynamic model for dissolved oxygen content in an aquaculture system of whiteleg shrimp. Additionally, a non-linear controller has been designed for hourly control. This time frequency is necessary because of the time required to reach the predicted levels of oxygen. The dynamic model has incorporated a shrimp growth model calibrated with real data. The results show how the controller maintains the dissolved oxygen levels in the desired target, helping to improve production and minimize costs.

Memory charts like EWMA-S2 or CUSUM-S2 are designed to detect a particular change in the process variance efficiently. However, the charts could be inefficient to detect some other shifts. To overcome this constraint, control charts with adaptive schemes that are efficient for a wide range of shifts can be used. This work proposes new adaptive EWMA charts for the dispersion (AEWMA-S2) based on an adaptive smoothing parameter that relates its value to the potential shift of the process. A Markov chain approach is used to optimize its design. A simulation experiment shows the advantage of the proposed charts. © 2020 Taylor & Francis Group, LLC.

El trabajo se realizó en la Reserva Nacional de Lachay, Lima - Perú, el mes de febrero de 1998, durante el Fenómeno El Niño. Se determinó el tamaño mínimo de unidad muestral (TUM) para la evaluación de la diversidad en pit-fall, quedando estandarizado éste en dos trampas pit-fall, con un esfuerzo de siete días por cada trampa. Se obtuvieron, también, valores altos y significativos de correlación utilizando el índice de Pearson, entre la diversidad de sólo el orden Coleoptera y la diversidad de cuatro ordenes de insectos juntos (Hemiptera, Coleoptera, Hymenoptera y Homoptera). Los resultados sugieren que la diversidad de los Coleópteros puede ser considerada como representativa de la diversidad de la comunidad de insectos del suelo.