Proposal of a production and management index (PMI) for tilapia farms

Tilapia is one of the most important species in aquaculture; however, there is no available index to show the performance of a production unit. It is desirable to assess the productivity using indexes, such as the production and management index for shrimps and the European production efficacy factor for broilers. These indexes are based on data production: growth, survival, and feed conversion of a full production cycle. Taking into account these parameters, we propose a production and management index (PMI) for tilapia that is applicable for a specific period of the production cycle. For the construction and validation of the PMI we have used production data from 8, 614 monthly records of 2 tilapia farms in Huila Department (Colombia), and because of the complexity of tilapia management, different anomalous situations have been detected and then defined as exceptions. As a result, 419 records were considered extreme values because 1 or more exceptions were met. The value of the PMI varies from 0 (the worst situation) to 3.55, which reflects high variability. We have constructed a PMI for tilapia as the product of 3 elements to obtain a positive value index. Instead of classic parameters, we had to calculate an adapted version of them: the relative average daily growth, the survival (as a complementary value of the estimated monthly mortality), and a feed conversion ratio index. To assess the utility of the PMI, some comparisons were performed using records from black and red tilapia. We observed significant differences depending on tilapia strain (PMIblack = 1.0248 vs. PMIred = 1.1661; P < 0.001), age (better values for small fish), and season (PMIrainy = 1.0847 vs. PMIdry = 1.1011; P = 0.026). According to these results, we can conclude that the PMI could be a useful tool for tilapia farmers, despite the complexity of the calculation

Impact of coffee crop renewal program on small producers in department cundinamarca (colombia)

The modernization of crops through renewal is a vital option for the restoration of the productivity and competitiveness of the coffee crop. The Federación Nacional de Cafeteros (National Federation of Coffee) is banking on a strategy that promotes renewal by providing resources to stimulate growers. As a result of the implementation of the program, it is hoped that it will reverse the aging process of coffee crops, consolidate a productive and competitive market, provide appropriate ages and densities and promote the use of coffee rust resistant varieties. Similarly, it is expected that small producers, who constitute the majority of farmers and who presumably suffer major limitations to independent renewal, will be the main beneficiaries

Extracción de características de ecg basadas en transformaciones no lineales y wavelets

Se presentan diferentes métodos de extracción de caracterIsticas en senales ECG normales y en presencia de eventos relacionados con cardiopatIa isquémica, basados en mediciones de diagnóstico, la transformada wavelet y el análisis no lineal de componentes principales. Con el fin de determinar las caracterIsticas que contribuyen de melor manera con el modelo, se aplican dos técnicas de selección efectiva de caracterIsticas empleando métodos estadIsticos multivariados y univariados. La evaluación de las técnicas de extracción propuestas se realiza mediante análisis discriminante lineal y máquinas de soporte vectorial, comparando el error en la clasificación de diferentes estados de funcionalidad cardIa- ca. Como resultado del análisis discriminante lineal se obtiene que las caracterIsticas más efectivas se consiguen empleando el análisis no lineal de componentes principales sobre un latido. En este caso, el error obtenido de clasifi- cación es de hasta el 0.22%, contra 6.78% en el caso de las wavelets, y 24.22% en el caso de las mediciones de diagnóstico. Con las máquinas de soporte vectorial se obtiene que las caracterIsticas más discriminantes se obtienen empleando wavelets aplicadas al latido con una precisión de clasificación hasta del 0.1%, contra 0.12% en el caso del análisis no lineal de componentes principales y 5.11% en el caso de las mediciones de diagnóstico.Different extraction methods were compared regarding the characteristics of normal ECG signals and those emitted in the presence of events related to ischemic cardiopathy based on diagnosis measurements, wavelet transformation and nonlinear analysis of main components. Methods were developed for automatic recognition between normal and ischemic ECG signals. Two effective feature selection techniques were proposed; one used multivariate statistical methods and the second univariate ones. Linear discriminatory evaluation and vector support machines were used for evaluating the proposed feature extraction techniques, comparing error when classifying different states of cardiac functionality. Nonlinear PCA offered slightly better performance compared to wavelet representation but was much better compared to diagnosis measurement. There was up to 0.22% error compared to 6.78% in the case of wavelets and 24.22% in the case of diagnostic measurements. Support vector machines increased the performance for all analysed feature extraction methods; more discriminating characteristics were obtained when using wavelets applied to heartbeat having up to 0.1% classification precision compared to 0.12% in the case of nonlinear analysis of main components and 5.11% in the case of diagnostic measurements

Pruebas de no linealidad: El método de los datos sustitutos.

En este articulo se presenta una introducción al método de los datos sustitutos, se empieza por mencionar el procedimiento general de Monte Carlo para la prueba de hipótesis nulas, posteriormente se introduce el método de los datos sustitutos para pruebas de no linealidad, proponiendo una jerarquía de hipótesis nulas y una batería de estadísticas no lineales que permitan comparar el comportamiento de una serie real contra un conjunto de sustitutos generados de tal manera que satisfagan las hipótesis nulas, se presenta un criterio discriminante por medio del cual se podrá rechazar o aceptar la hipótesis. Finalmente se presenta un ejemplo del funcionamiento de los algoritmos utilizando la serie de Lorenz

Attitudes, Social Influences and Decision-Making in the Choice of Antimicrobials for the Treatment of Bovine Mastitis

The excessive and irrational use of antimicrobials for the control of bovine mastitis has been the subject of study throughout the world for many decades. Currently, the use of antimicrobials in livestock is of great interest from the “One Health” approach. Scientific research has revealed that the reasons for the inappropriate use of antimicrobials in production are related to human behavior, political, commercial, and economic factors. The objective of this study was to understand the attitudes toward the use of the laboratory and the social influences for decision-making in the choice of antimicrobials in the treatment of bovine mastitis in the North of Antioquia, Colombia. The study was developed through mixed methods (cross-sectional and grounded theory) with a convergent triangulation design. Two hundred and sixteen dairy farmers and 9 veterinarians participated. The results allow us to conclude that the problem of antimicrobial resistance related to mastitis and udder health planning depends on both technical aspects and access to knowledge and to laboratory services and, perhaps, even more importantly, on the culture and social relations that are established between the dairy farmer and the other actors of the dairy chain in the north of Antioquia

Genetic diversity and population structure in Physalis peruviana and related taxa based on InDels and SNPs derived from COSII and IRG markers

AbstractThe genus Physalis is common in the Americas and includes several economically important species, among them is Physalis peruviana that produces appetizing edible fruits. We studied the genetic diversity and population structure of P. peruviana and characterized 47 accessions of this species along with 13 accessions of related taxa consisting of 222 individuals from the Colombian Corporation of Agricultural Research (CORPOICA) germplasm collection, using Conserved Orthologous Sequences (COSII) and Immunity Related Genes (IRGs). In addition, 642 Single Nucleotide Polymorphism (SNP) markers were identified and used for the genetic diversity analysis. A total of 121 alleles were detected in 24 InDels loci ranging from 2 to 9 alleles per locus, with an average of 5.04 alleles per locus. The average number of alleles in the SNP markers was two. The observed heterozygosity for P. peruviana with InDel and SNP markers was higher (0.48 and 0.59) than the expected heterozygosity (0.30 and 0.41). Interestingly, the observed heterozygosity in related taxa (0.4 and 0.12) was lower than the expected heterozygosity (0.59 and 0.25). The coefficient of population differentiation FST was 0.143 (InDels) and 0.038 (SNPs), showing a relatively low level of genetic differentiation among P. peruviana and related taxa. Higher levels of genetic variation were instead observed within populations based on the AMOVA analysis. Population structure analysis supported the presence of two main groups and PCA analysis based on SNP markers revealed two distinct clusters in the P. peruviana accessions corresponding to their state of cultivation. In this study, we identified molecular markers useful to detect genetic variation in Physalis germplasm for assisting conservation and crossbreeding strategies

Virus-induced gene silencing (VIGS) in cape gooseberry (Physalis peruviana L., Solanaceae)

Cape gooseberry (Physalis peruviana, L.) is a herbaceous plant belonging to the Solanaceae family that produces an edible berry appreciated for its nutraceutical and pharmaceutical properties. Its production is often limited by diseases and reproducible fruit quality. Recent studies have reported genes associated with fruit quality and resistance response to the root-infecting fungus Fusarium oxysporum f. sp. physali (Foph,) which causes vascular wilt. In order to standardize a method to validate the biological function of candidate genes in the non-model species P. peruviana, we tested the robust approach in reverse genetics, virus-induced gene silencing (VIGS). In this study, we validated and optimized VIGS using an insert of the phytoene desaturase (PDS) gene in a silencing viral vector generated from tobacco rattle virus (TRV). Leaves infiltrated with Agrobacterium (GV3101 strain) showed photo-bleached segments, which were distinctive for PDS suppression at 7 days post-infection (dpi). More than half of the treated plants showed photo-bleaching, indicating an efficiency rate of 50 % of the VIGS protocol. The results of this study showed that VIGS can be used for future functional gene characterization implicated in the immune response, disease resistance and fruit quality in capegooseberry